CN101198831A - freezer - Google Patents

Abstract

A refrigerating device, equipped with a refrigerant circuit (20) for performing a vapor compression refrigeration cycle, the refrigerant circuit (20) is composed of an outdoor circuit (30) provided with an outdoor heat exchanger (32) and a compression mechanism (31). ) are formed by parallel connection of multiple cooling circuits (70, 80) with cooling heat exchangers (72, 84) respectively; in at least one cooling circuit (70, 80) of the system, the sub-compressor (85) is connected in series In the refrigeration unit for cooling the heat exchanger (84), hot gas introduction passages (46, 89) are provided in order to be able to cope with various defrosting operation modes without additionally installing a defrosting mechanism other than the refrigerant circuit (20). , the hot gas introduction passage (46, 89) can selectively introduce the gas refrigerant discharged from the compression mechanism (31) of the outdoor circuit (30) into at least one of the cooling heat exchangers (72, 84) to perform The defrosting operation of the refrigeration cycle using the cooling heat exchanger (72, 84) as the condenser.

Description

freezer

technical field

[0001] The present invention relates to a refrigerating device having a refrigerant circuit of a vapor compression refrigeration cycle, the refrigerant circuit is connected in parallel with an outdoor circuit provided with an outdoor heat exchanger and a compression mechanism, each having a cooling heat exchanger It is composed of cooling circuits of multiple systems; in particular, it relates to a refrigeration device, which is connected in series with a cooling heat exchanger and a sub-compressor in at least one cooling circuit of the system.

Background technique

Carry out the freezer of refrigerating cycle known all the time, be widely used as the cooling machine of refrigerator and freezer (or refrigerated showcase or freezer showcase) of storing food etc. For example, Patent Document 1 discloses a refrigeration device including a plurality of heat exchangers for cooling inside a refrigerator or the like. In this refrigerating apparatus, a refrigerating heat exchanger for cooling the inside of the refrigerating showcase serving as the refrigerator and a freezing heat exchanger for cooling the inside of the refrigerating showcase serving as the freezer are connected in parallel to one outdoor unit. Furthermore, in this refrigeration system, in addition to the compression mechanism (main compressor) of the outdoor unit, a sub-compressor is provided between the refrigeration heat exchanger and the outdoor unit. In this refrigeration system, a single-stage refrigeration cycle using a refrigeration heat exchanger as an evaporator and a two-stage compression refrigeration cycle using a refrigeration heat exchanger as an evaporator and a sub-compressor as a low-stage compressor are performed in one refrigerant circuit. cycle.

There is a problem in this type of freezer and is: once the moisture in the air is attached to the refrigerating heat exchanger or the freezing heat exchanger, the attached frost will hinder the cooling of the air in the storehouse. Therefore, it is necessary to melt the adhering frost, that is, to defrost the freezing heat exchanger.

Here, in the refrigerating device of Patent Document 1, since the evaporating temperature of the refrigerant is set to be low in the refrigerating heat exchanger, the problem of frosting in the refrigerating heat exchanger is particularly serious, and according to the sub-compressor , the refrigerating heat exchanger, the expansion valve of the refrigerating heat exchanger, and the refrigerating heat exchanger perform a refrigerating cycle that circulates the refrigerant to defrost the refrigerating heat exchanger.

Therefore, the refrigerant circuit of the above-mentioned refrigerating device is provided with a conversion mechanism capable of converting the first action of cooling operation and the second action of defrosting operation; The heat exchanger sucks in refrigerant and discharges it to the suction side of the compression mechanism of the outdoor unit; the second action for defrosting operation is that the sub-compressor sucks in refrigerant from the refrigerating heat exchanger and discharges the refrigerant to the refrigerating unit. heat exchanger.

[0006] In addition, during the defrosting operation for defrosting the refrigerating heat exchanger, the refrigerant is sent from the refrigerating heat exchanger to the refrigerating heat exchanger while performing the second operation in the refrigerant circuit. In this defrosting operation, the refrigerant absorbs heat from the air in the refrigerated showcase and evaporates, is sucked into the sub-compressor, and is sent to the refrigerating heat exchanger after being compressed by the sub-compressor. Refrigerant condenses and melts frost in the refrigeration heat exchanger. The condensed refrigerant expands in front of the refrigerating heat exchanger through the expansion valve, and then returns to the refrigerating heat exchanger to absorb heat from the air in the refrigerator and evaporate. As such, in the above-mentioned refrigerating device, when the refrigerant flows into the sub-compressor, the refrigerating heat exchanger, the expansion valve, and the refrigerating heat exchanger in sequence, the heat recovered by the refrigerant from the air in the refrigerating showcase is used to cool the refrigerating heat. The exchanger defrosts.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2004-353995

Contents of the invention

solve the problem

But, in above-mentioned freezer, when the moisture in the air adheres to the refrigerating heat exchanger and freezes and the attached frost hinders the cooling of the air in the storehouse, there is no way to cool the refrigerating heat exchanger with the heat of the refrigerant. Perform defrosting. Therefore, in the above-mentioned refrigerating apparatus, in order to defrost the refrigerating heat exchanger, it is necessary to provide a defrosting mechanism such as a dedicated electric heater outside the refrigerant circuit, which complicates the structure of the apparatus.

And, in above-mentioned refrigerating device, since the refrigerating heat exchanger is used as heat source to defrost the refrigerating heat exchanger, it is necessary to make the refrigerating heat exchanger and the refrigerating heat exchanger absorb heat and dissipate heat in the defrosting operation to obtain a balance, Therefore, a problem of restrictive design also arises.

[0009] The present invention is conceived in view of the above-mentioned problems, and its purpose is to not additionally set up other defrosting mechanisms outside the refrigerant circuit and to be able to correspond to a variety of defrosting modes of operation while cooling the refrigerating heat exchanger. cooling heat exchangers such as cooling or refrigeration heat exchangers without imposing restrictions on the design of these heat exchangers.

Solution

The first invention is based on the following refrigerating device, which is equipped with a refrigerant circuit (20) that carries out a vapor compression refrigeration cycle, and the refrigerant circuit (20) is provided with an outdoor heat exchanger (32) and the outdoor circuit (30) of the compression mechanism (31) are connected in parallel with cooling circuits (70, 80) of a plurality of systems with cooling heat exchangers (72, 84) respectively, and the cooling circuits of at least one system In (80), the sub-compressor (85) and the cooling heat exchanger (84) are connected in series.

And, this refrigerating device has been equipped with hot gas introduction path (46,89) (100,102), and this hot gas introduction path (46,89) (100,102) is the compression mechanism (31) of outdoor circuit (30) The blown gas refrigerant is selectively introduced into at least one of a plurality of cooling heat exchangers (72, 84), and a defrosting path (25) capable of performing a defrosting operation is provided, and the defrosting path (25) A refrigeration cycle is performed using the cooling heat exchanger (72, 84) as a condenser.

In the first invention, the following actions are performed during the defrosting operation: that is, the high-temperature refrigerant ejected by the compression mechanism (31) of the outdoor circuit (30) is passed through the hot gas introduction passage (46, 89) (100, 102 ) is introduced into at least one of a plurality of cooling heat exchangers (72, 84), and the cooling heat exchanger (72, 84) is used as a condenser to perform a refrigeration cycle. Therefore, frost adhering to the cooling heat exchangers (72, 84) is melted by the heat absorbed by the heat exchanger serving as the evaporator at this time and the heat of compressing the refrigerant in the compression mechanism (31). This defrosting operation can be performed by selectively cooling the heat exchanger by providing hot gas introduction passages (46, 89) (100, 102).

The second invention is characterized in that: in the first invention, the first cooling circuit (70) and the second cooling circuit (80) are connected in parallel in the outdoor circuit (30), and the first cooling circuit (70) has the first cooling circuit (70). A cooling heat exchanger (72), the second cooling circuit (80) has a second cooling heat exchanger (84) and a sub-compressor (85). The first cooling circuit (70) can be used as, for example, a refrigeration circuit for cooling a refrigerator or a refrigerated showcase, and the second cooling circuit can be used as a freezing circuit for cooling a freezer or a refrigerated showcase, for example.

In the second invention, in the refrigeration unit having the first cooling heat exchanger (72) and the second cooling heat exchanger (84), by using the hot gas introduction path (46, 89), the first At least one of the cooling heat exchanger (72) and the second cooling heat exchanger (84) performs a defrosting operation as a refrigeration cycle of the condenser. For example, only one of the first cooling heat exchanger (72) and the second cooling heat exchanger (84) can be defrosted, or the first cooling heat exchanger (72) and the second cooling heat Both exchangers (84) perform defrosting operation simultaneously.

The third invention is characterized in that in the first invention, a plurality of cooling circuits (80) equipped with cooling heat exchangers (84) and auxiliary compressors (85) are connected in parallel to the outdoor circuit (30).

In the third invention, in the freezer having a plurality of cooling heat exchangers (84), by using hot gas introduction passages (46, 89), at least one of the plurality of cooling heat exchangers (84) can be One unit performs defrosting operation as a refrigeration cycle of the condenser. For example, when there are two cooling heat exchangers (84), it is possible to defrost only one of the cooling heat exchangers (84), or to defrost both cooling heat exchangers (84) simultaneously. Frost runs.

The feature of the 4th invention is: in the arbitrary invention of the 1st to the 3rd invention, the outdoor circuit (30) is connected with the air heat exchanger (for example air conditioner heat exchanger) (62 that has adjusted air temperature) ) air heat exchanger circuit (such as air-conditioning circuit) (60), and constituted to be able to perform the first defrosting operation and the second defrosting operation, the first defrosting operation uses cooling heat exchangers (72, 84) as condensation The air heat exchanger (62) is used as the evaporator, the cooling heat exchanger (72, 84) is used as the condenser, and the outdoor heat exchanger (32) is used as the evaporator in the second defrosting operation.

In the fourth invention, in the refrigeration unit equipped with a plurality of cooling heat exchangers (72, 84) and air heat exchangers (62), by using the hot air introduction path (46, 89), it is possible to At least one of the stage cooling heat exchangers (72, 84) performs a defrosting operation as a refrigeration cycle of the condenser. Specifically, a first defrosting operation and a second defrosting operation can be performed, the first defrosting operation uses at least one of the cooling heat exchangers (72, 84) as a condenser and the air heat exchanger (62) is an evaporator, and the second defrosting operation uses at least one of the cooling heat exchangers (72, 84) as a condenser, and the outdoor heat exchanger (32) as an evaporator

The fifth invention is characterized in that: in any invention from the first to the fourth invention, the hot gas introduction path (46, 89) has a high-level side hot gas path (46) and a low-level side hot gas path (89); The high-level side hot gas passage (46) connects the discharge pipe (45) of the compression mechanism (31) of the outdoor circuit (30) and the base pipe (42) of the low-pressure air pipe of each cooling circuit (70, 80). The refrigerant is allowed to flow from the discharge pipe (45) of the above-mentioned compression mechanism (31) to each cooling heat exchanger (72, 84); the low-stage side hot gas passage (89) is connected to the discharge pipe (22b) of the auxiliary compressor (85) And the suction pipe (88) allows the refrigerant to flow from the discharge pipe (22b) of the sub-compressor (85) to the cooling heat exchanger (84) connected to the sub-compressor (85) during the defrosting operation.

In the fifth invention, during the defrosting operation, the gas refrigerant discharged from the compression mechanism (31) of the outdoor circuit (30) first passes through each cooling circuit (70) from the high-level side hot gas passage (46). , 80) the base pipe (42) of the low-pressure gas pipe and flows to each cooling heat exchanger (72,84). Then, for example, in a first cooling circuit (such as a refrigeration circuit) (70) without an auxiliary compressor (85), the above-mentioned blown gas refrigerant flows into a first cooling heat exchanger (such as a refrigeration heat exchanger) (72), And this heat exchanger functions as a condenser. In addition, in the second cooling circuit (such as a refrigeration circuit) (80) provided with a sub-compressor (85), the above-mentioned discharged gas refrigerant flows into a second cooling heat exchanger (such as a refrigeration circuit) through a low-stage side hot gas passage (89). heat exchanger) (84), which functions as a condenser.

[0021] And, by selectively introducing the blown gas refrigerant into each of the cooling heat exchangers (72, 84), frost attached to at least one of the cooling heat exchangers (72, 84) is melted. For example, in the structure of the second invention, only one of the first cooling heat exchanger (72) and the second cooling heat exchanger (84) can be defrosted, or the first cooling heat exchanger (72) and the second cooling heat exchanger (84) perform defrosting operation simultaneously; in the structure of the third invention, when there are two cooling heat exchangers (84), only the cooling heat exchanger ( 84) one of them performs the defrosting operation, or simultaneously performs the defrosting operation on both sides of the two cooling heat exchangers (84). At this time, since the cooling heat exchanger (84) connected to the sub-compressor (85) does not introduce the discharged gas refrigerant of the low-stage side hot gas passage (89), it is possible not to make the cooling heat exchanger (84) defrost status.

The sixth invention is characterized in that in the fifth invention, the first compressor (31a) and the second compressor (32b) connected in parallel as the compression mechanism (31) of the outdoor circuit (30) are provided. and the third compressor (31c), the four-way reversing valve (37) connected to the suction side of the above-mentioned compression mechanism (31), the high-level on-off valve (SV1) set in the high-level hot gas passage (46), and the The low-stage on-off valve (SV2) of the low-stage hot gas passage (89); the suction pipe (41a) of the first compressor (31a) is connected to the first valve port of the four-way reversing valve (37) through the check valve (CV1) (P1), the above-mentioned check valve (CV1) prevents the refrigerant from flowing to the first compressor (31a); the suction pipe (41b) of the second compressor (32b) is connected to the second valve of the four-way reversing valve (37) port (P2); the suction pipe (41c) of the third compressor (31c) is connected to the third valve port (P3) of the four-way reversing valve (37) through the check valve (CV2), and the check valve (CV2) Refrigerant is prohibited from flowing to the third compressor (31c); the high-pressure inlet pipe (47) connected to the high-pressure pipe of the compression mechanism (31) is connected to the fourth valve port (P4) of the four-way reversing valve (37); The passage (46) is connected to the suction pipe (41a) of the first compressor (31a); the four-way reversing valve (37) can be converted into a first state and a second state structurally, and the first state is to communicate with the first valve port (P1) and the second valve port (P2) communicate with the third valve port (P3) and the fourth valve port (P4) at the same time, and the second state is to communicate with the first valve port (P1) and the fourth valve port (P4) at the same time It communicates with the second valve port (P2) and the third valve port (P3).

In the sixth invention, during defrosting operation, the four-way reversing valve (37) is set to the second state, and the high-stage on-off valve (SV1) and the low-stage on-off valve (SV2) are opened to activate the compression mechanism (31) two or one of the second compressor (31b) and the third compressor (31c). In this state, the blown gas refrigerant blown out from the compression mechanism (31) first passes through the base pipe (42) of the low-pressure gas pipe of each cooling circuit (70, 80) from the high-grade side hot gas passage (46) to each cooling circuit (70, 80). Cool the heat exchangers (72, 84). Next, for example, in a first cooling circuit (such as a refrigeration circuit) (70) without an auxiliary compressor (85), the above-mentioned blown gas refrigerant flows into a first cooling heat exchanger (such as a refrigeration heat exchanger) (72) , while the heat exchanger functions as a condenser. In addition, in the second cooling circuit (such as a refrigeration circuit) (80) provided with a sub-compressor (85), the above-mentioned discharged gas refrigerant flows into a second cooling heat exchanger (such as a refrigeration circuit) through a low-stage side hot gas passage (89). heat exchanger) (84), which functions as a condenser.

[0024] And, by selectively introducing the blown gas refrigerant into each of the cooling heat exchangers (72, 84), frost attached to at least one of the cooling heat exchangers (72, 84) is melted. For example, in the structure of the second invention, only one of the first cooling heat exchanger (72) and the second cooling heat exchanger (84) can be defrosted, or the first cooling heat exchanger Both (72) and the second cooling heat exchanger (84) perform defrosting operation simultaneously; in the structure of the third invention, when there are two cooling heat exchangers (84), only the cooling heat exchanger can One of the (84) performs a defrosting operation, or simultaneously performs a defrosting operation on both sides of the two cooling heat exchangers (84). At this time, in the cooling heat exchanger (84) connected to the sub-compressor (85), since the low-stage on-off valve (SV2) is closed, the discharged gas refrigerant is not introduced into the low-stage hot gas passage (89), so It is possible to prevent the cooling heat exchanger (84) from being in a defrosted state. And, after the condensation process of the cooling heat exchanger (72, 84), the low-pressure gas refrigerant that has completed the expansion process and the evaporation process passes through the suction pipe (41b) and the suction pipe (41c) from the four-way reversing valve (37). It is sucked into the second compressor (32b) and the third compressor (31c).

The seventh invention is characterized in that: in the fifth invention, the first compressor (31a), the second compressor (32b) and the compressor (32b) connected in parallel as the compression mechanism (31) of the outdoor circuit (30) are provided The third compressor (31c), the four-way reversing valve (37) connected to the suction side of the compression mechanism (31), and the low-stage on-off valve (SV2) provided in the low-stage hot gas passage (89); the first The suction pipe (41a) of the compressor (31a) is connected to the first valve port (P1) of the four-way reversing valve (37); the suction pipe (41b) of the second compressor (32b) is connected to the four-way reversing valve (37 ) of the second valve port (P2); the suction pipe (41c) of the third compressor (31c) is connected to the third valve port (P3) of the four-way reversing valve (37) through the check valve (CV2). The stop valve (CV2) prevents the refrigerant from flowing to the third compressor (31c); the high-grade side hot gas passage (46) is connected to the fourth valve port (P4) of the four-way reversing valve (37); the four-way reversing valve (37 ) can be converted into the first state and the second state structurally, the first state is to communicate with the first valve port (P1) and the fourth valve port (P4) while communicating with the second valve port (P2) and the third valve port ( P3), the second state is communicating with the first valve port (P1) and the second valve port (P2) while communicating with the third valve port (P3) and the fourth valve port (P4).

In the seventh invention, during the defrosting operation, the four-way reversing valve (37) is set to the second state, the low-stage on-off valve (SV2) is opened, and the second compressor of the compression mechanism (31) is started (31b) and two or one of the third compressor (31c). In this state, the blown gas refrigerant blown out from the compression mechanism (31) first passes through the low pressure of each cooling circuit (70, 80) from the high-grade side hot gas passage (46) and the four-way reversing valve (37). The base pipe (42) of the gas tube flows to each cooling heat exchanger (72, 84). Next, for example, in a first cooling circuit (such as a refrigeration circuit) (70) that is not provided with a sub-compressor (85), the above-mentioned blown gas refrigerant flows into a first cooling heat exchanger (such as a refrigeration heat exchanger) (72 ), while the heat exchanger functions as a condenser. In addition, in the second cooling circuit (such as a refrigeration circuit) (80) provided with a sub-compressor (85), the above-mentioned discharged gas refrigerant flows into a second cooling heat exchanger (such as a refrigeration circuit) through a low-stage side hot gas passage (89). heat exchanger) (84), which functions as a condenser.

[0027] And, the blown gas refrigerant is selectively introduced into each cooling heat exchanger (72, 84), and frost attached to at least one cooling heat exchanger (72, 84) is melted. For example, in the structure of the second invention, only one of the first cooling heat exchanger (72) and the second cooling heat exchanger (84) can be defrosted, or the first cooling heat exchanger (72) and the second cooling heat exchanger (84) both perform defrosting operation at the same time; in the structure of the third invention, when there are two cooling heat exchangers (84), only the cooling heat exchanger ( 84), one of them performs the defrosting operation, or the two cooling heat exchangers (84) both perform the defrosting operation at the same time. At this time, in the cooling heat exchanger (84) connected with the sub-compressor (85), since the low-stage on-off valve (SV2) is closed, the discharged gas refrigerant is not introduced into the low-stage hot gas passage (89), so it can This cooling heat exchanger (84) is prevented from being in a defrosting state. And, after the condensation process of the cooling heat exchanger at (72, 84), the low-pressure gas refrigerant that has completed the expansion process and the evaporation process passes through the suction pipe (41b) and the suction pipe (41c) from the four-way reversing valve (37). ) is sucked into the second compressor (32b) and the third compressor (31c).

The 8th invention is characterized in that: in the first invention, the hot gas introduction passage (46, 89) is provided with the first introduction passage (96) and the second introduction passage (97); the first introduction passage (96) makes the outdoor The discharge gas refrigerant of the compression mechanism (31) of the circuit (30) is introduced into the sub-compressor (85); the second introduction path (97) makes the discharge gas refrigerant of the sub-compressor (85) lead into the cooling heat exchanger ( 84).

In the eighth invention, the refrigerant gas discharged from the compression mechanism (31) of the outdoor circuit (30) is introduced into the sub-compressor (85) through the first introduction passage (96) to be further compressed, and thereafter, the sub-compressor (85) is further compressed. The gas refrigerant discharged from the compressor (85) is introduced into the cooling heat exchanger (84) through the second introduction passage (97), and is used for defrosting of the cooling heat exchanger (84). As described above, during the defrosting operation of the eighth invention, the refrigerant is compressed by both the compression mechanism (31) and the sub-compressor (85) of the outdoor circuit (30). The heat given.

The feature of the ninth invention is: in the eighth invention, the second introduction passage (97) connects the compression mechanism (31) and the cooling heat exchanger (84) of the outdoor circuit (30); and, the first introduction passage (96) branching from the second introduction path (97) to connect the auxiliary compressor (85) so that a part of the gas refrigerant ejected by the compression mechanism (31) of the outdoor circuit (30) is introduced into the auxiliary compressor (85); A discharge pipe (98) of a sub-compressor (85) is connected to the side of the compression mechanism (31) of the outdoor circuit (30) of the second introduction passage (97).

In the ninth invention, a part of the gas refrigerant ejected by the compression mechanism (31) of the outdoor circuit (30) is introduced into the auxiliary compressor (85) through the first introduction passage (96) and further compressed; The gas refrigerant discharged from the sub-compressor (85) and the gas refrigerant discharged from the above-mentioned compression mechanism (31) flowing into the second introduction passage (97) are merged and introduced into the cooling heat exchanger (84) for utilization. Defrost in the cooling heat exchanger (84). As described above, during the defrosting operation of the ninth invention, as in the eighth invention, since the refrigerant is compressed by both the compression mechanism (31) and the sub-compressor (85) of the outdoor circuit (30), Therefore, the amount of heat given to the refrigerant during the defrosting operation increases.

The tenth invention is characterized in that: in the ninth invention, a liquid injection passage (99) is provided, and the liquid injection passage (99) introduces a part of the liquid refrigerant flowing out from the cooling heat exchanger (84) into the sub-compressor machine (85).

[0033] In the tenth invention, an operation of injecting a part of the refrigerant condensed into a liquid state in the cooling heat exchanger (84) in the ninth invention into the liquid supplied by the sub-compressor (85) is performed. As a result, an excessive increase in temperature of the refrigerant gas discharged from the sub-compressor (85) can be suppressed compared to the case where liquid injection is not performed.

The feature of the eleventh invention is: in the ninth invention, the sub-compressor (85) is made of variable frequency compressor.

In the eleventh invention, when the defrosting operation is performed in the ninth invention, the temperature of the refrigerant gas discharged from the sub compressor (85) tends to rise, and by performing control to reduce the operating capacity, the sub compressor can be suppressed. The temperature of the refrigerant gas discharged from the machine (85) rises excessively.

The twelfth invention is characterized in that in the first invention, the hot gas introduction path (100, 102) is directly connected to the discharge pipe (45) of the compression mechanism (31) of the outdoor circuit (30) and the cooling heat exchanger At least one of the gas side piping (110, 112) of (72, 84).

[0037] In the twelfth invention, the high-temperature gas refrigerant ejected from the compression mechanism (31) of the outdoor circuit (30) is introduced into at least one of the cooling heat exchangers (72, 84) from the gas side. Therefore, it is possible to perform a defrosting operation using the cooling heat exchanger (72, 84) as a condenser and the other heat exchanger as an evaporator.

The feature of the thirteenth invention is: in the twelfth invention, the hot gas introduction path (100, 102) is connected with the ejection pipe (45) of the compression mechanism (31) of the outdoor circuit (30) and a plurality of cooling The pipes (110, 112) on the gas side of the heat exchangers (72, 84), and the refrigeration device is equipped with a switching mechanism (103) capable of switching or selecting a plurality of cooling heat exchangers (72, 84).

[0039] In the thirteenth invention, a plurality of cooling heat exchangers (72, 84) can be switched or selected for defrosting operation.

[0040] The fourteenth invention is characterized in that: in the twelfth or thirteenth invention, a flow adjustment mechanism (101) is provided in the hot gas introduction path (100, 102).

[0041] In the fourteenth invention, the flow rate of the high-temperature gas refrigerant flowing through the hot gas introduction passage (100, 102) can be adjusted.

Invention effect

According to the present invention, the cooling circuit (80) of at least one system among the cooling circuits (70, 80) of a plurality of systems connected in parallel is connected in series with a cooling heat exchanger (84) and an auxiliary compressor (85 ) in the freezing device, there are hot gas introduction passages (46, 89) (100, 102), and the hot air introduction passages (46, 89) (100, 102) make the compression mechanism (31) of the outdoor circuit (30) spray The outgoing gas refrigerant is selectively introduced into at least one of the plurality of cooling heat exchangers (72, 84), and the cooling heat exchanger (72, 84) is used as a condenser to perform a defrosting operation of the refrigeration cycle. Therefore, it is possible to defrost the cooling heat exchangers (72, 84) by using the heat absorbed in the outdoor heat exchanger (32) and the heat obtained by compressing the refrigerant in the above-mentioned compression mechanism (31). When a circuit for air-conditioning is provided, the heat absorbed by the air-conditioning heat exchanger (62) can be used to cool the heat exchanger (72, 84) for defrosting.

[0043] Therefore, it is possible to perform defrosting operations in various forms without additionally providing a dedicated defrosting mechanism such as an electric heater outside the refrigerant circuit (20), and it is possible to prevent the device structure from becoming complicated. And, since the refrigeration heat exchanger is used as the heat source to defrost the refrigeration heat exchanger differently from the existing device, it is not necessary to make the suction heat exchanger (72, 84) The balance combination of heat and heat dissipation is good, so the degree of freedom in design is also improved.

If according to above-mentioned second invention, because as cooling circuit, can make the first cooling circuit (70) that has the first cooling heat exchanger (72), and have the second cooling heat exchanger (84) and secondary compressor The second cooling circuit (80) of the machine (85) is connected in parallel to the outdoor circuit (30), so only one of the first cooling heat exchanger (72) and the second cooling heat exchanger (84) can be The defrosting operation is performed, or the defrosting operation is performed on both the first cooling heat exchanger (72) and the second cooling heat exchanger (84) simultaneously. Therefore, various defrosting operation modes can be implemented.

If according to above-mentioned 3rd invention, because as cooling circuit, make to have possessed cooling heat exchanger (84) and sub-compressor (85) multiple refrigerating circuit (80) is connected in parallel to outdoor circuit (30), therefore For example, when there are two cooling heat exchangers (84), the defrosting operation can be performed on only one of the cooling heat exchangers (84), or the two cooling heat exchangers (84) can be defrosted simultaneously. Defrost operation. Therefore, various forms of defrosting operation can be performed.

According to the above fourth invention, for the outdoor circuit (30), multiple cooling circuits (70, 80) are connected to the air heat exchanger circuit (60), and the first defrosting operation and the second defrosting operation can be performed ; the first defrosting operation uses at least one of the plurality of cooling heat exchangers (72, 84) as a condenser and the air heat exchanger (62) as an evaporator; the second defrosting operation uses the cooling heat exchanger ( 72, 84) at least one as a condenser and the outdoor heat exchanger (32) as an evaporator; therefore, more diverse forms of defrosting operation can be performed.

If according to the above-mentioned fifth invention, the hot gas introduction path (46, 89) has possessed the high-level side hot gas path (46) and the low-level side hot gas path (89); the high-level side hot gas path (46) is connected to the outdoor circuit (30) The discharge pipe (45) of the compression mechanism (31) and the base pipe (42) of the low-pressure air pipe of each cooling circuit (70, 80) allow the refrigerant to flow from the discharge pipe ( 45) flow to each cooling heat exchanger (72, 84); the low-stage side hot gas passage (89) connects the discharge pipe (22b) and suction pipe (88) of the sub-compressor (85), allowing the refrigerant to flow from The discharge pipe (22b) of the sub-compressor (85) flows to the cooling heat exchanger (84) connected to the sub-compressor (85); therefore, during defrosting operation, the compression mechanism ( 31) The discharged gas refrigerant is selectively introduced into each cooling heat exchanger (72, 84). Furthermore, by selectively introducing the gas refrigerant discharged from the compression mechanism (31) from the high-stage hot gas passage (46) and the low-stage hot gas passage (89) to the cooling heat exchangers (72, 84), , can correspond to various forms of defrosting operation.

If according to above-mentioned 6th invention, owing to have used three compressors (31a, 31b, 31c) as the compression mechanism (31) of outdoor circuit (30), use four-way reversing valve (37) at suction side simultaneously, In the refrigerant circuit (20) having a plurality of cooling heat exchangers (72, 84), it is possible to cope with various defrosting operation modes without complicating the circuit structure.

According to the above-mentioned seventh invention, similar to the above-mentioned sixth invention, use three compressors (31a, 31b, 31c) as the compression mechanism (31) of the outdoor circuit (30), and use a four-way compressor on the suction side at the same time The reversing valve (37) can cope with various defrosting operation modes without complicating the circuit structure in the refrigerant circuit (20) provided with a plurality of cooling heat exchangers (72, 84).

[0050] According to the above eighth invention, since the amount of heat given to the refrigerant during the defrosting operation is increased, the defrosting capability of the cooling heat exchanger (84) is improved. Therefore, by performing the control of the present invention when the defrosting capacity is insufficient, the cooling heat exchanger (84) can be effectively defrosted.

[0051] According to the above-mentioned ninth invention, as in the eighth invention, since the amount of heat given to the refrigerant during the defrosting operation is increased, the defrosting capability of the cooling heat exchanger (84) is improved. Therefore, by performing the control of the present invention when the defrosting capacity is insufficient, it is possible to efficiently defrost the cooling heat exchanger (84).

According to the above-mentioned tenth invention, by injecting the liquid during the defrosting operation of the ninth invention, it is possible to avoid an abnormal rise in the temperature of the refrigerant discharged from the sub-compressor (85), and to reliably protect the sub-compressor (85). ).

According to the above-mentioned eleventh invention, the operation capacity of the sub-compressor (85) during the defrosting operation of the ninth invention can be reduced to avoid an abnormal rise in the temperature of the refrigerant discharged from the sub-compressor (85), so that Securely protect the sub-compressor (85).

According to the above-mentioned twelfth invention, since the hot gas introduction path (100, 102) is directly connected to the ejection pipe (45) of the compression mechanism (31) of the outdoor circuit (30) and the cooling heat exchanger (72, 84) At least one of the gas-side piping (110, 112), so the high-temperature gas refrigerant ejected from the compression mechanism (31) of the outdoor circuit (30) is introduced into at least one of the cooling heat exchangers from the gas side. Therefore, the defrosting operation can be performed with the cooling heat exchanger (72, 84) serving as the condenser and the other heat exchanger serving as the evaporator.

According to the above-mentioned thirteenth invention, since the hot gas introduction passage (100, 102) is connected to the ejection pipe (45) of the compression mechanism (31) of the outdoor circuit (30) and a plurality of cooling heat exchangers (72, 84) of the gas side piping (110, 112), and a conversion mechanism (103) that can switch or select multiple cooling heat exchangers (72, 84) is provided, therefore, it is possible to switch or select multiple cooling heat exchangers ( 72, 84) for defrosting operation.

[0056] According to the above fourteenth invention, the hot gas introduction passage (100, 102) is provided with a flow adjustment mechanism (101), so the flow rate of the high-temperature gas refrigerant flowing through the hot gas introduction passage (100, 102) can be adjusted. Here, if the flow rate of the gas refrigerant flowing through the hot gas introduction passage (100, 102) is large, the frost attached to the cooling heat exchanger (72, 84) will start to melt at once, which may cause frost lumps around it to fall off. However, since the frost is gradually melted by reducing the flow rate, the falling of the frost block can be prevented.

Description of drawings

[0057] FIG. 1 shows a refrigerant circuit diagram of a refrigeration device according to a first embodiment.

Fig. 2 is a refrigerant circuit diagram showing the operation during cooling operation according to the first embodiment.

Fig. 3 is a refrigerant circuit diagram showing an example of the defrosting operation during cooling according to the first embodiment.

Fig. 4 is a refrigerant circuit diagram of another example other than the cooling defrosting operation according to the first embodiment.

Fig. 5 is a refrigerant circuit diagram showing operations during heating operation according to the first embodiment.

Fig. 6 is a refrigerant circuit diagram showing an example of defrosting operation during heating according to the first embodiment.

FIG. 7 shows a refrigerant circuit diagram of another example other than the defrosting operation during heating according to the first embodiment.

Fig. 8 shows a refrigerant circuit diagram of the refrigeration system according to the second embodiment.

Fig. 9 is a refrigerant circuit diagram showing operations during air-cooling operation according to the second embodiment.

Fig. 10 is a refrigerant circuit diagram showing an example of the defrosting operation during cooling according to the second embodiment.

Fig. 11 is a refrigerant circuit diagram showing an example other than the cooling-time defrosting operation according to the second embodiment.

Fig. 12 is a refrigerant circuit diagram showing operations during heating operation according to the second embodiment.

Fig. 13 is a refrigerant circuit diagram showing an example of defrosting operation during heating according to the second embodiment.

Fig. 14 shows a refrigerant circuit diagram of an example other than the defrosting operation during heating according to the second embodiment.

Fig. 15 shows a refrigerant circuit diagram of the refrigeration system according to the third embodiment.

Fig. 16 is a refrigerant circuit diagram showing the operation during cooling operation according to the third embodiment.

Fig. 17 is a refrigerant circuit diagram showing an example of the defrosting operation during cooling according to the third embodiment.

Fig. 18 is a refrigerant circuit diagram showing an example other than the cooling defrosting operation according to the third embodiment.

Fig. 19 is a refrigerant circuit diagram showing the operation during the heating operation according to the third embodiment.

Fig. 20 is a refrigerant circuit diagram showing an example of defrosting operation during heating according to the third embodiment.

Fig. 21 shows a refrigerant circuit diagram of an example other than the defrosting operation during heating according to the third embodiment.

Fig. 22 is a refrigerant circuit diagram showing an example of defrosting operation during cooling according to the fourth embodiment.

Fig. 23 shows a refrigerant circuit diagram of a refrigeration system according to a fifth embodiment.

Symbol Description

10-freezing device, 20-refrigerant circuit, 22b-ejection pipe (freezing side branch air pipe), 30-outdoor circuit, 31-compression mechanism, 31a-DC inverter compressor (first compressor), 32b - the first fixed frequency compressor (the second compressor), 31c - the second fixed frequency compressor (the third compressor), 32 - the outdoor heat exchanger, 37 - the third four-way reversing valve, 41a - the first Suction pipe (suction pipe), 41b-the second suction pipe (suction pipe), 41c-the third suction pipe (suction pipe), 42-the first low-pressure air pipe (base pipe of low-pressure air pipe), 45-ejection pipe (high-pressure air pipe) trachea), 46-advanced side hot gas passage (hot gas introduction passage), 47-high pressure introduction pipe, 60-air conditioning circuit, 62-air conditioning heat exchanger, 70-refrigeration circuit (cooling circuit), 72-refrigeration heat exchanger (cooling heat exchanger), 80-refrigeration circuit (cooling circuit), 84-refrigeration heat exchanger (cooling heat exchanger), 85-auxiliary compressor (sub-compressor), 88-suction pipe (88), 89-lower side Hot gas path (hot gas introduction path), CV1-check valve, CV2-check valve, P1-first valve port, P2-second valve port, P3-third valve port, P4-fourth valve port, SV1- High-level on-off valve, SV2-low-level on-off valve, 10-refrigerating device, 20-refrigerant circuit, 22b-discharge pipe (branched air pipe on the freezing side), 25-defrosting path, 30-outdoor circuit, 31-compression mechanism , 31a-DC inverter compressor (first compressor), 32b-first fixed frequency compressor (second compressor), 31c-second fixed frequency compressor (third compressor), 32-outdoor heat exchanger , 37-the third four-way reversing valve, 41a-the first suction pipe (suction pipe), 41b-the second suction pipe (suction pipe), 41c-the third suction pipe (suction pipe), 42-the first low-pressure air pipe (base pipe of low-pressure air pipe), 45-ejection pipe (high-pressure air pipe), 46-advanced side hot gas passage (hot air introduction passage), 47-high pressure inlet pipe, 60-air conditioning circuit, 62-air conditioning heat exchanger, 70- Refrigeration circuit (cooling circuit), 72-refrigeration heat exchanger (cooling heat exchanger), 80-refrigeration circuit (cooling circuit), 84-refrigeration heat exchanger (cooling heat exchanger), 85-auxiliary compressor (secondary compressor machine), 88-suction pipe (88), 89-lower side hot gas passage (hot gas introduction passage), 96-first introduction passage, 97-second introduction passage, 98-discharge pipe, 99-liquid injection passage, 100 -Hot gas introduction passage, 101-Flow rate adjustment mechanism, 102-Branch pipe (Hot gas introduction passage), 110-Piping on the gas side, 112-Piping on the gas side, CV1, CV2-Return valve, P1-First valve port, P2-second valve port, P3-third valve port, P4-fourth valve port, SV1-advanced side switch valve, SV2-lower side switch valve,

Detailed ways

Embodiment Below according to accompanying drawing, describe in detail the embodiments of the present invention.

"The first embodiment"

A first embodiment of the present invention will be described below. The refrigerating device (10) of the present embodiment is installed in the air-conditioning and cooling display cabinets used in convenience stores and the like.

As shown in Figure 1, the refrigerating unit (10) of present embodiment has outdoor unit (11), air-conditioning unit (12), as the refrigerated showcase (13) of refrigerator and as the refrigerated showcase of freezer (14). The outdoor unit (11) is arranged outdoors. On the other hand, the air-conditioning unit (12), the refrigerated display case (13) and the refrigerated display case (14) are all arranged in stores such as convenience stores.

Above-mentioned outdoor unit (11) is provided with outdoor circuit (30), is provided with air-conditioning circuit (air heat exchanger circuit) (60) at air-conditioning unit (12), is provided with refrigeration circuit at refrigerated showcase (13) (the first cooling circuit) (70), and a freezing circuit (second cooling circuit) (80) is provided in the freezing showcase (14). In this refrigerating apparatus (10), these circuits (30, 60, 70, 80) are connected by piping to form a refrigerant circuit (20). The refrigerant circuit (20) includes a circuit of a refrigeration/freezing system and a circuit of an air conditioning system.

[0063] On the refrigerating/freezing system side of the refrigerant circuit (20), the refrigerating circuit (70) and the freezing circuit (80) serving as cooling circuits are connected in parallel to the outdoor circuit (30). Specifically, the refrigeration circuit (70) and the refrigeration circuit (80) are connected to the outdoor circuit (30) through the first liquid side communication pipe (21) and the first gas side communication pipe (22). One end of the first liquid side communication pipe (21) is connected to the outdoor circuit (30). The other end of the first liquid side communication pipe (21) is divided into two sides, one end of the branch (refrigerated side branch liquid pipe (21a)) is connected to the liquid side end of the refrigeration circuit (70), and the other end (freeze side branch liquid pipe (21a)) is connected to the liquid side end of the refrigeration circuit (70). A tube (21b)) connects the liquid side end of the refrigeration circuit (80). One end of the first gas side communication pipe (22) is connected to the outdoor circuit (30). The other end of the first gas side connecting pipe (22) is divided into two branches, one end of the branch (refrigerating side branched gas pipe (22a)) is connected to the gas side end of the refrigeration circuit (70), and the other end of the branch (refrigerated side branched gas pipe (22a) 22b)) is connected to the gas side of the refrigeration circuit (80).

And, on the air-conditioning system side of the above-mentioned refrigerant circuit (20), the air-conditioning circuit (60) passes through the second liquid side communication pipe (23) branched from the first liquid side communication pipe (21) and the second gas The side communication pipe (24) is connected to the outdoor circuit (30). One end of the second liquid side communication pipe (23) is connected to the outdoor circuit (30) through the first liquid side communication pipe (21), and the other end is connected to the liquid side end of the air conditioning circuit (60). One end of the second gas side connecting pipe (24) is connected to the outdoor circuit (30), and the other end is connected to the gas side of the air conditioning circuit (60).

"Outdoor unit"

As mentioned above, the outdoor unit (11) has an outdoor circuit (30). The outdoor circuit (30) is provided with a compression mechanism (31), an outdoor heat exchanger (32), a receiver (33), and an outdoor expansion valve (34). Moreover, the outdoor circuit (30) is provided with a first four-way reversing valve (35), a second four-way reversing valve (36), a third four-way reversing valve (37), a liquid side closing valve (38) , a first gas side closing valve (39a), and a second gas side closing valve (39b). In this outdoor circuit (30), the liquid side shutoff valve (38) is connected to the first liquid side communication pipe (21), the first gas side shutoff valve (39a) is connected to the first gas side communication pipe (22), and the second The second gas side closing valve (39b) is connected to the second gas side connecting pipe (24).

Above-mentioned compression mechanism (31), by the DC variable frequency compressor (31a) as the first compressor, the first fixed frequency compressor (31b) as the second compressor, the second compressor as the third compressor Fixed-frequency compressors (31c) are connected in parallel with each other to form. Each compressor (31a, 31b, 31c) is a fully-sealed high-pressure semi-dome scroll compressor. To the DC inverter compressor (31a), electric power is supplied by an inverter. The DC inverter compressor (31a) can adjust the operating capacity by changing the output frequency of the inverter to change the rotation speed of the motor. On the other hand, in the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c), the electric motors always operate at a fixed rotation speed, and the operation capacity is fixed.

One end of the first suction pipe (41a) is connected to the suction side of the DC inverter compressor (31a), and one end of the second suction pipe (41b) is connected to the suction side of the first constant frequency compressor (31b) , one end of the third suction pipe (41c) is connected to the suction side of the second fixed-frequency compressor (31c).

The other end of the first suction pipe (41a) is connected with the first low-pressure air pipe (42) and the first connecting pipe (43a) as the low-pressure air pipe base pipe of refrigeration/freezing system, the first low-pressure air pipe (42) Connect the first gas side shutoff valve (39a). The first suction pipe (41a) is connected to the first valve port (P1) of the third four-way reversing valve (37) through the first communication pipe (43a). A check valve (CV1) for preventing refrigerant from flowing to the DC inverter compressor (31a) is provided on the first communication pipe (43a). The other end of the second suction pipe (41b) is connected to the second valve port (P2) of the third four-way reversing valve (37). The other end of the third suction pipe (41c) is connected to the second low-pressure air pipe (44) and the second communicating pipe (43b), and the second low-pressure air pipe (44) is connected to the second four-way reversing valve (36). The third suction pipe (41c) is connected to the third valve port (P3) of the third four-way reversing valve (37) through the second communication pipe (43b). A check valve (CV2) for preventing refrigerant from flowing to the second fixed-frequency compressor (31c) is provided on the second communication pipe (43b).

[0069] The ejection side of the compression mechanism (31) is connected with a high-pressure air pipe (ejection pipe) (45). One end of the high-stage hot gas passage (46) is connected to the high-pressure gas pipe (45), and the other end of the high-stage hot gas passage (46) is connected to the first suction pipe (41a). In the high-stage hot gas passage (46), a first solenoid valve (SV1) as a high-stage on-off valve is provided. The high-level side hot gas passage (46) connects the discharge pipe (45) of the compression mechanism (31) of the outdoor circuit (30) and the first low-pressure air pipe (42) of the low-pressure air pipe base pipe of each cooling circuit (70, 80), It is a passage for allowing the refrigerant to flow from the discharge pipe (45) of the compression mechanism (31) to the respective cooling heat exchangers (72, 84) during the defrosting operation.

[0070] One end of a high-pressure introduction pipe (47) is connected between the discharge side of the compression mechanism (31) of the high-level hot gas passage (46) and the first electromagnetic valve (SV1). The high-pressure introduction pipe (47) communicates with the high-pressure line of the compression mechanism (31) through the high-stage side hot gas passage (46), and the other end of the high-pressure introduction pipe (47) is connected to the fourth valve port of the third four-way reversing valve (37). (P4).

The 3rd four-way reversing valve can convert the first state and the second state, and the first state is that the first valve port (P1) and the second valve port (P2) communicate with each other and the third valve port (P3) and the fourth valve port (P4) communicate with each other (the state shown by the solid line in Figure 1), the second state is that the first valve port (P1) and the fourth valve port (P4) communicate with each other and the second valve port (P2) and The third valve port (P3) communicates with each other (the state shown by the dotted line in Fig. 1).

The ejection side of DC inverter compressor (31a) connects the first ejection pipe (48a), and the ejection side of the first constant frequency compressor (31b) connects the second ejection pipe (48b), and the second constant frequency compressor (31b) connects the second ejection pipe (48b). The discharge side of the frequency compressor (31c) is connected to the third discharge pipe (48c). A check valve (CV3) is provided in the first discharge pipe (48a), and the check valve (CV3) prevents the refrigerant from flowing to the DC inverter compressor (31a), and a check valve (CV3) is provided in the second discharge pipe (48b). valve (CV4), the check valve (CV4) prevents the refrigerant from flowing to the first fixed-frequency compressor (31b), and a check valve (CV5) is installed in the third discharge pipe (48c), and the check valve (CV5 ) prohibits refrigerant from flowing to the second fixed frequency compressor (31c). The first discharge pipe (48a), the second discharge pipe (48b), and the third discharge pipe (48c) merge to connect the above-mentioned high-pressure air pipe (45). A discharge connection pipe (49) is connected between the connection point of the third discharge pipe (48c) and the high-pressure air pipe (45) and the check valve (CV5).

The first valve port (P1) of the first four-way reversing valve (35) connects the high-pressure air pipe (45), and the second valve port (P2) connects the outdoor heat exchanger (32) by the first air pipe (50) , the third valve port (P3) is connected to the second four-way reversing valve (36) through the gas connecting pipe (52), and the fourth valve port (P4) is connected to the second gas side closed valve (39b) through the second gas pipe (51) ). The first four-way reversing valve (35) can switch between the first state and the second state. The first state is that the first valve port (P1) and the second valve port (P2) communicate with each other and the third valve port (P3) and the fourth valve port (P4) communicate with each other (the state shown by the solid line in Figure 1), the second state is that the first valve port (P1) and the fourth valve port (P4) are connected and the second valve port (P2) and the The three valve ports (P3) communicate with each other (the state shown by the dotted line in Fig. 1).

The first valve port (P1) of the second four-way reversing valve (36) connects the ejection connecting pipe (49), and its third valve port (P3) connects the second low-pressure air pipe (44), and its fourth The valve port (P4) is connected with the gas connecting pipe (52). And, the second valve port (P2) of the second four-way reversing valve (36) is sealed. The second four-way reversing valve (36) can switch between the first state and the second state. The first state is that the first valve port (P1) and the second valve port (P2) communicate with each other and the third valve port (P3) It communicates with the fourth valve port (P4) (the state shown in the solid line in Figure 1), the second state is that the first valve port (P1) and the fourth valve port (P4) communicate with each other and the second valve port (P2) It communicates with the third valve port (P3) (the state shown by the dotted line in Fig. 1).

[0075] The outdoor heat exchanger (32) is a fin-and-tube (fin-and-tube) heat exchanger of plate-fin type (crossfin) constituting a heat source side heat exchanger. An outdoor fan (32a) is installed near the outdoor heat exchanger (32a). The outdoor air is sent to the outdoor heat exchanger (32) by the outdoor fan (48), and the heat exchange between the refrigerant and the outdoor air is performed in the outdoor heat exchanger (32). As mentioned above, one end of the outdoor heat exchanger (32) is connected to the first four-way reversing valve (35). On the other hand, the other end of the outdoor heat exchanger (32) is connected to the top of the receiver (33) through the first liquid pipe (53). In this first liquid pipe (51) there is a check valve (CV6), which allows the refrigerant to flow from the outdoor heat exchanger (32) to the receiver (33) and prohibits the flow of refrigerant from the receiver ( 33) flow to the outdoor heat exchanger (32).

The bottom of receiver (33) is connected with an end of second liquid pipe (54). The other end of this second liquid pipe (54) is connected to the liquid side shutoff valve (38). A check valve (CV7) is provided in the second liquid pipe (54), which allows the refrigerant to flow from the receiver (33) to the liquid side closing valve (38) and prohibits the refrigerant from flowing from the liquid side closing valve. (38) flows to the receiver (33).

[0077] Between the check valve (CV7) of the second liquid pipe (54) and the liquid side closing valve (38), one end of the third liquid pipe (55) is connected. The other end of this third liquid pipe (55) is connected to the top of the receiver (33). And, a check valve (CV8) is provided in the third liquid pipe (53), and the check valve (CV8) allows the refrigerant to flow from the liquid side closing valve (38) to the receiver (33) and prohibits the refrigerant from flowing from the receiver. (33) flows to the liquid side closing valve (38).

[0078] Between the receiver (33) and the check valve (CV7) of the second liquid pipe (52) is connected one end of the fourth liquid pipe (56). The other end of the fourth liquid pipe (56) is connected to the first liquid pipe (53) between the outdoor heat exchanger (32) and the check valve (CV6). Furthermore, an outdoor expansion valve (34) is provided in the fourth liquid pipe (56).

[0079] Outdoor circuit (30) is also provided with various sensors and pressure switches. For example, a discharge temperature sensor (57) and a discharge pressure sensor (not shown) are provided in the high-pressure air pipe (45). A high pressure switch (58) is provided on the first discharge pipe (48a) and the third discharge pipe (48c). In addition, a suction temperature sensor and a suction pressure sensor (not shown) are provided in each suction pipe (41a, 41b, 41c). Furthermore, an outside air temperature sensor (59) is provided near the outdoor fan (32a).

"air conditioning unit"

As mentioned above, the air conditioning unit (12) has an air conditioning circuit (air heat exchanger circuit) (60). In the air-conditioning circuit (60), an air-conditioning expansion valve (61) and an air heat exchanger (62) are arranged in sequence from the liquid side end to the gas side end. The air conditioner heat exchanger (62) is composed of a plate-fin (crossfin) fin-and-tube heat exchanger. Heat exchange between the refrigerant and indoor air is performed in the air conditioner heat exchanger (62). On the other hand, the air conditioner expansion valve (61) is composed of an electronic expansion valve.

[0081] The air conditioning unit (12) is provided with a heat exchanger temperature sensor (63) and a refrigerant temperature sensor (64). The heat exchanger temperature sensor (63) is installed in the heat pipe of the air conditioner heat exchanger (62). A refrigerant temperature sensor (64) is installed near the gas side end of the air conditioning circuit (60). In addition, an internal temperature sensor (65) and an air-conditioning fan (66) are provided in the air-conditioning unit (12). The indoor air in the store is sent to the air-conditioning heat exchanger (62) by the air-conditioning fan (66).

[0082] "Refrigerated Showcase"

As mentioned above, the refrigerated showcase (13) has a refrigerated circuit (70). In the refrigerating circuit (70), a refrigerating expansion valve (71) and a refrigerating heat exchanger (first cooling heat exchanger) (72) are arranged sequentially from the liquid side end to the gas side end. The refrigeration heat exchanger (72) is constituted by a plate-fin (crossfin) fin-and-tube (fin-and-tube) heat exchanger. The refrigeration heat exchanger (72) performs heat exchange between the refrigerant and the air in the refrigerator. On the other hand, the refrigeration expansion valve (71) is composed of an electronic expansion valve.

[0083] The refrigerated showcase (13) is provided with a heat exchanger temperature sensor (73) and a refrigerant temperature sensor (74). The heat exchanger temperature sensor (73) is installed on the heat pipe of the refrigeration heat exchanger (72). A gas refrigerant temperature sensor (74) is installed near the gas side end of the refrigeration circuit (70), and a liquid refrigerant temperature sensor (75) is installed near the liquid side end of the refrigeration circuit (70). In addition, a refrigerator interior temperature sensor (76) and a refrigerator interior fan (77) are provided in the refrigerator showcase (13). The air in the refrigerated showcase (13) is sent to the refrigerated heat exchanger (72) by the fan (77) in the refrigerated store.

" freezing showcase "

As mentioned above, the refrigerated display case (14) has a refrigerated circuit (80). In the refrigerating circuit (80), from the liquid side to the gas side, a refrigerant heat exchanger (81), a drainpan heater (82), a refrigeration expansion valve (83), A refrigeration heat exchanger (second cooling heat exchanger) (84), and a DC inverter compressor used as an auxiliary compressor (sub-compressor) (85). The refrigerating heat exchanger (84) is constituted by a plate-fin type fin-tube heat exchanger. The refrigerating heat exchanger (84) performs heat exchange between the refrigerant and the air in the store. On the other hand, the frozen expansion valve (83) is composed of an electronic expansion valve. The refrigeration expansion valve (83) is an expansion valve provided in the refrigeration circuit (30) whose opening can be adjusted.

[0085] The refrigerant heat exchanger (81) is a heat exchanger for exchanging heat between refrigerants, for example composed of a plate heat exchanger. The refrigerant heat exchanger (81) has a high-pressure side flow path (81a) and a low-pressure side flow path (81b). ) is connected to the branch pipe (86) branched from the downstream side of the high pressure side flow path (81a) of the freezing side branch liquid pipe (21b). The branch pipe (86) has an electronic expansion valve (87) on the upstream side of the low-pressure side flow path (81b), and is connected to an intermediate pressure position of the auxiliary compressor on the downstream side of the low-pressure side flow path (81b). An economizer is formed by the refrigerant heat exchanger (81) and the electronic expansion valve (87).

[0086] A check valve (CV9) is provided at the freezing-side branch air pipe (22b) serving as the discharge pipe of the auxiliary compressor (85), and the check valve (CV9) allows the flow of refrigerant from the auxiliary compressor (85) Spray and prohibit reverse flow. A low-stage hot gas passage (89) is connected to a position downstream of the check valve (CV9) of the refrigerating-side branch air pipe (22b) and a suction pipe (88) serving as a suction pipe of the auxiliary compressor (85). This low-stage side hot gas passage (89) connects the above-mentioned refrigeration-side branch air pipe (22b) and suction pipe (88), and is a passage that allows refrigerant to flow from the refrigeration-side branch air pipe (22b) to the refrigeration heat exchanger (84) during defrosting operation. , a second solenoid valve (SV2) is provided as a low-stage on-off valve.

[0087] A heat exchanger temperature sensor (90) and a refrigerant temperature sensor (91, 92) are provided in the freezing showcase (14). A heat exchanger temperature sensor (90) is mounted on the heat pipe of the refrigeration heat exchanger (84). A gas refrigerant temperature sensor (91) is installed near the gas side end of the refrigeration circuit (80). A liquid refrigerant temperature sensor (92) is installed near the liquid side end of the refrigeration circuit (80). The water pan heater temperature sensor (93) is installed near the water pan heater (82). In addition, a temperature sensor (94) in the freezer and a fan (95) in the freezer are provided in the freezer showcase (14). By the fan (95) in the freezer, the air in the freezer (14) is sent to the freezer heat exchanger (84).

"Overall Structure of Refrigerant Circuit"

As mentioned above, the refrigerant circuit (20) of this embodiment has a circuit on the side of the refrigeration/freezing system and a circuit on the side of the air conditioning system, and the circuit on the side of the refrigeration/freezing system is provided with an outdoor heat exchanger (32) The outdoor circuit (30) of the compression mechanism (31) and cooling circuits (refrigerating circuit (70) and freezing circuit (80)) each having a plurality of cooling heat exchangers (72, 84) are connected in parallel with each other. In at least one refrigeration circuit (80) of the cooling circuit of the system, an auxiliary compressor (85) is connected in series to a refrigeration heat exchanger (84).

[0089] In addition, as a hot gas introduction path (46, 89) Equipped with a high-stage hot gas passage (46) and a low-stage hot gas passage (89), it is structurally possible to perform a defrosting operation of a refrigeration cycle using the cooling heat exchanger (72, 84) as a condenser.

[0090] And, in the refrigerant circuit (20), an air-conditioning circuit (60) having an air-conditioning heat exchanger (62) for indoor air-conditioning is included. And, as will be described later, it is structurally possible to perform defrosting operation during cooling and defrosting operation during heating; defrosting operation during cooling (first defrosting operation) to cool the heat exchangers (72, 84 ) as the condenser and the air conditioner heat exchanger (62) as the evaporator; the defrosting operation during heating (the second defrosting operation), the cooling heat exchanger (72, 84) as the condenser and the outdoor heat exchanger (32) as an evaporator.

-Operation action-

The main operation performed by the above-mentioned refrigeration device (10) will be described below.

[0091] "air-conditioning operation"

Air-conditioning operation is: carry out the cooling of the air in the warehouse in the refrigerated display case (13) and the refrigerated display case (14), and carry out the cooling of the indoor air in the air conditioner unit (12) to make the store cool.

As shown in Figure 2, in the refrigerant circuit (20), the first four-way reversing valve (35), the second four-way reversing valve (36) and the third four-way reversing valve (37 ) is set to the first state. And, when the outdoor expansion valve (34) is fully closed, the openings of the air-conditioning expansion valve (61), the refrigerating expansion valve (71), and the freezing expansion valve (83) are properly regulated; A solenoid valve (SV1) and a second solenoid valve (SV2) of the low-stage hot gas passage (89) are closed. In this state, the DC variable frequency compressor (31a), first fixed frequency compressor (31b), second fixed frequency compressor (31c) and auxiliary compressor (85) are operated.

The refrigerant ejected from the DC variable frequency compressor (31a), the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) passes through each ejection pipe (48a, 48b, 48c) Confluence at high-pressure air pipe (45), and be sent to outdoor heat exchanger (32) by the first four-way reversing valve (35). In the outdoor heat exchanger (32), the refrigerant dissipates heat and condenses to the outdoor air. The refrigerant condensed in the outdoor heat exchanger (32) flows through the receiver (33) through the first liquid side connecting pipe (21), and is distributed to the refrigerating side branch liquid pipe (21a) and the freezing side branch liquid pipe ( 21b) and the second liquid side connecting pipe (23).

[0094] The refrigerant flowing into the refrigerating circuit (70) from the refrigerating side branch liquid pipe (21a) is decompressed when passing through the refrigerating expansion valve (71) and then introduced into the refrigerating heat exchanger (72). In the refrigeration heat exchanger (72), the refrigerant absorbs heat from the air in the refrigerator and evaporates. At this time, in the refrigeration heat exchanger (72), the evaporation temperature of the refrigerant is set at about -5°C, for example. The refrigerant evaporated in the refrigeration heat exchanger (72) flows into the first gas side communication pipe (22) from the refrigeration side branch gas pipe (22a). In the refrigerated showcase (13), the interior air cooled by the refrigerated heat exchanger (72) is supplied into the interior so that the interior temperature is maintained at about 5°C, for example.

The refrigerant flowing into the refrigeration circuit (80) from the freezing side branch liquid pipe (21b) passes through the refrigerant heat exchanger (81) and the water pan heater (82), and then passes through the freezing expansion valve (83) After being decompressed, it is introduced into the refrigeration heat exchanger (84). In the refrigeration heat exchanger (84), the refrigerant absorbs heat from the air in the store and evaporates. At this time, in the refrigeration heat exchanger (84), the evaporation temperature of the refrigerant is set at about -30°C, for example. In the refrigerated showcase (14), the interior air cooled by the refrigerated heat exchanger (84) is supplied into the interior so that the interior temperature is maintained at, for example, about -20°C.

[0096] The refrigerant evaporated in the refrigeration heat exchanger (84) is sucked into the auxiliary compressor (85) through the suction pipe (88). The refrigerant compressed by the auxiliary compressor (85) flows from the discharge pipe (98) into the first gas side communication pipe (22) through the refrigeration side branch pipe (22b).

[0097] In the first gas side connecting pipe (22), the refrigerant sent from the refrigerating circuit (70) and the refrigerant sent from the refrigerating circuit (80) merge. And, these refrigerants flow into the first suction pipe (41a) and the second suction pipe (41b) from the first gas side communication pipe (22) through the first low-pressure gas pipe (42), and are sucked into the DC inverter compressor (31a) And the first constant frequency compressor (31b). The DC inverter compressor (31a) and the first constant frequency compressor (31b) respectively compress the sucked refrigerant and discharge it to the first discharge pipe (48a) and the second discharge pipe (48b).

[0098] On the other hand, the refrigerant flowing into the second liquid side communication pipe (23) is supplied to the air conditioning circuit (60). The refrigerant flowing into the air-conditioning circuit (60) is decompressed when passing through the air-conditioning expansion valve (61) and introduced into the air-conditioning heat exchanger (62). In the air conditioner heat exchanger (62), the refrigerant absorbs heat from the indoor air and evaporates. In the air conditioner unit (12), indoor air cooled by the air conditioner heat exchanger (62) is supplied into the store. The refrigerant evaporated in the air conditioner heat exchanger (62) flows into the outdoor circuit (30) through the second gas side connecting pipe (24), and sequentially passes through the first four-way reversing valve (35) from the second gas pipe (51) After connecting with the second four-way reversing valve (36), it is sucked into the second fixed-frequency compressor (31c) from the second low-pressure air pipe (44) through the third suction pipe (41c). The second fixed frequency compressor (31c) compresses the sucked refrigerant and discharges it to the third discharge pipe (48c).

And, when the air-conditioning operation of Fig. 2 is performed, by setting the third four-way reversing valve (37) to the first state, two compressors (31a, 31b) are used in the refrigeration/freezing system side circuit, and One compressor (31c) is used in the air-conditioning system side circuit; however, it is also possible to use one compressor (31a ), and use two compressors (31b, 31c) in the side circuit of the air conditioning system. Moreover, when the third four-way reversing valve (37) is set to one of the first state or the second state, one of the three compressors (31a, 31b, 31c) can be stopped, and One compressor is used for each side circuit of the refrigeration/freezing system and the side circuit of the air conditioning system.

[0100] "Defrosting Operation During Air Conditioning"

As the defrosting operation during cooling, it is possible to perform the defrosting operation shown in Fig. 3 that simultaneously defrosts the refrigerating heat exchanger (72) and the refrigerating heat exchanger (84), and perform refrigerating while cooling the refrigerating heat exchanger (84). Figure 4 defrosting operation of defrosting of heat exchanger (72). In addition, the refrigerant flow (defrosting path) during the defrosting operation is represented by a symbol ( 25 ).

[0101] First, the defrosting operation shown in FIG. 3 will be described.

As shown in Figure 3, in the refrigerant circuit (20), the first four-way reversing valve (35) and the second four-way reversing valve (36) are set in the first state, and the third and fourth The through reversing valve (37) is set in the second state. And, the outdoor expansion valve (34) is fully closed, and the refrigerating expansion valve (71) and the freezing expansion valve (83) are fully opened, and on the other hand, the opening degree of the air conditioning expansion valve (61) is properly adjusted. The first solenoid valve (SV1) of the high-stage hot gas passage (46) and the second solenoid valve (SV2) of the low-stage hot gas passage (89) are opened. In this state, the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) are operated.

The refrigerant ejected from the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) merges in the high-pressure air pipe (45) through each ejection pipe (48b, 48c), and flows from the first fixed-frequency compressor (31c) A four-way reversing valve (35) is sent to the outdoor heat exchanger (32) by the first air pipe (50). In the outdoor heat exchanger (32), the refrigerant dissipates heat and condenses to the outdoor air. The refrigerant condensed in the outdoor heat exchanger (32) flows into the first liquid side communication pipe (21) through the receiver (33), and then flows into the second liquid side communication pipe (23).

On the other hand, part of the refrigerant ejected by the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) ) flows to the first gas side connecting pipe (22), and is divided into the refrigerating side branch gas pipe (22a) and the freezing side branch gas pipe (22b).

The refrigerant flowing through the refrigerated side branch air pipe (22a) flows into the refrigerated heat exchanger (72), and radiates heat and condenses to the air in the storehouse. At this time, the frost adhering to the refrigeration heat exchanger (72) is melted. The refrigerant condensed in the refrigeration heat exchanger (72) passes through the refrigeration expansion valve (71), flows through the refrigeration side branch liquid pipe (21a), and flows into the second liquid side connection pipe (23) and the refrigeration from the outdoor unit (11). Confluence of agents.

[0106] The refrigerant flowing through the branch air pipe (22b) at the freezing side flows into the freezing heat exchanger (84) through the low-stage side hot gas passage (89), and radiates heat and condenses to the air in the storehouse. At this time, the frost adhering to the refrigeration heat exchanger (84) melts. The refrigerant condensed in the refrigeration heat exchanger (84) passes through the refrigeration expansion valve (83), the water pan heater (82), and the refrigerant heat exchanger (81), and flows into the refrigeration side branch liquid pipe (21b), And it flows into the second liquid side communication pipe (23) and joins with the refrigerant from the outdoor unit (11).

[0107] The refrigerant that joins in the second liquid side communication pipe (23) is supplied to the air conditioning circuit (60). The refrigerant flowing into the air-conditioning circuit (60) is decompressed when passing through the air-conditioning expansion valve (61) and introduced into the air-conditioning heat exchanger (62). In the air conditioner heat exchanger (62), the refrigerant absorbs heat from the room air and evaporates. In the air conditioner unit (12), the indoor air cooled by the air conditioner heat exchanger (62) is supplied into the store. The refrigerant evaporated in the air conditioner heat exchanger (62) flows into the outdoor circuit (30) through the second gas side connecting pipe (24), and passes through the first four-way reversing valve (35) in sequence from the second gas pipe (51). ) and the second four-way reversing valve (36), from the second low-pressure air pipe (44) through the second suction pipe (41b) and the third suction pipe (41c), to be sucked into the first fixed-frequency compressor (31b) And the second constant frequency compressor (31c). The first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) compress the sucked refrigerant and discharge it to the second discharge pipe (48b) and the third discharge pipe (48c).

[0108] As described above, in the defrosting operation shown in FIG. 3, the heat absorbed by the indoor heat exchanger (62) and the heat obtained by compressing the refrigerant in the compressors (31b, 31c) can be simultaneously performed. Defrost of refrigerated heat exchanger (72) and refrigerated heat exchanger (84).

And, although the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) are used in the operation as shown in Figure 3, it is also possible to use only one of the compressors for operation .

[0110] And, only when the refrigeration heat exchanger (84) is defrosting, it is sufficient to close the refrigeration expansion valve (71) in the operating state as shown in Figure 3 so that the refrigerant does not flow into the refrigeration showcase (13).

[0111] Next, the defrosting operation shown in FIG. 4 will be described.

As shown in Figure 4, in the refrigerant circuit (20), the first four-way reversing valve (35) and the second four-way reversing valve (36) are set to the first state, and the third The four-way reversing valve (37) is set to the second state. And, the outdoor expansion valve (34) is fully closed and the refrigerating expansion valve (71) is fully opened, and the opening degrees of the freezing expansion valve (83) and the air conditioning expansion valve (61) are properly adjusted. The first solenoid valve (SV1) of the high-stage side hot gas passage (46) is opened, and the second solenoid valve (SV2) of the low-stage side hot gas passage (89) is closed. In this state, the first fixed frequency compressor (31b), the second fixed frequency compressor (31c) and the auxiliary compressor (85) are operated.

The refrigerant ejected by the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) merges in the high-pressure air pipe (45) through each ejection pipe (48b, 48c), and flows from the first The four-way reversing valve (35) is sent to the outdoor heat exchanger (32) by the first air pipe (50). In the outdoor heat exchanger (32), the refrigerant dissipates heat and condenses to the outdoor air. The refrigerant condensed in the outdoor heat exchanger (32) passes through the receiver (33) and flows through the first liquid side connecting pipe (21), and then is divided into the second liquid side connecting pipe (23) and the freezing side branch liquid pipe ( 21b).

The refrigerant flowing into the refrigeration circuit (80) from the freezing side branch liquid pipe (21b) passes through the refrigeration expansion valve (83) after the refrigerant heat exchanger (81) and the water pan heater (82) After being decompressed, it is introduced into the refrigeration heat exchanger (84). In the refrigeration heat exchanger (84), the refrigerant absorbs heat from the air in the store and evaporates. At this time, in the refrigeration heat exchanger (84), the evaporation temperature of the refrigerant is set at about -30°C, for example. In the refrigerated showcase (14), the interior air cooled by the refrigerated heat exchanger (84) is supplied into the interior, and the interior temperature is maintained at about -20°C, for example.

[0115] The refrigerant evaporated in the refrigeration heat exchanger (84) is sucked into the auxiliary compressor (85) through the suction pipe (88). The refrigerant compressed by the auxiliary compressor (85) flows from the discharge pipe (98) through the refrigeration side branch pipe (22b) into the first gas side communication pipe (22). At this time, the opening degree of the electronic expansion valve (87) provided in the branch pipe (86) is controlled, and the economizer functions. Therefore, the discharge pressure of the auxiliary compressor (85) is increased to approximately the same level as the discharge pressures of the first constant frequency compressor (31b) and the second constant frequency compressor (31c).

On the other hand, part of the refrigerant ejected from the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) It flows through the first gas side connecting pipe (22), joins the refrigerant from the refrigerating unit (14), and flows into the refrigerating side branch gas pipe (22a).

The refrigerant flowing through the branch air pipe (22a) on the refrigeration side flows into the refrigeration heat exchanger (72), and radiates heat and condenses to the air in the storehouse. At this time, the frost adhering to the refrigeration heat exchanger (72) is melted. The refrigerant condensed in the refrigerating heat exchanger (72) passes through the refrigerating expansion valve (71) and flows through the refrigerating side branch liquid pipe (21a), and then flows to the second liquid side together with the refrigerant from the outdoor unit (11). Piping (23) and branch liquid pipe (21b) on the freezing side.

[0118] The refrigerant flowing through the second liquid side communication pipe (23) is supplied to the air conditioning circuit (60). The refrigerant flowing into the air-conditioning circuit (60) is decompressed when passing through the air-conditioning expansion valve (61) and introduced into the air-conditioning heat exchanger (62). In the air conditioner heat exchanger (62), the refrigerant absorbs heat from the room air and evaporates. In the air conditioner unit (12), the indoor air cooled by the air conditioner heat exchanger (62) is supplied into the store. The refrigerant evaporated in the air conditioner heat exchanger (62) flows into the outdoor circuit (30) through the second gas side connecting pipe (24), and sequentially passes through the first four-way reversing valve (35) from the second gas pipe (51) and the second four-way reversing valve (36), from the second low-pressure air pipe (44) through the second suction pipe (41b) and the third suction pipe (41c) to be sucked into the first fixed frequency compressor (31b) and the second Two constant frequency compressors (31c). The refrigerant compressed and sucked by the first constant frequency compressor (31b) and the second constant frequency compressor (31c) is discharged to the second discharge pipe (48b) and the third discharge pipe (48c).

[0119] As described above, in the defrosting operation shown in FIG. 4 , it is possible to use the heat absorbed by the indoor heat exchanger (62) and the refrigeration heat exchanger (84) and compress and refrigerate in the compressors (31b, 31c, 85). The heat obtained by the agent is used to defrost the refrigerated heat exchanger (72).

[0120] And, although the operation of using two of the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) is shown in FIG. 4, only one of the compressors may be operated.

" heating operation "

The heating operation is: cooling the air in the store in the refrigerated display case (13) and the refrigerated display case (14), and heating the indoor air in the air conditioner unit (12) to heat the store.

As shown in Figure 5, in the refrigerant circuit (20), the first four-way reversing valve (35) is set to the second state respectively, and the second four-way reversing valve (36) and the third The four-way reversing valve (37) is set to the first state. In addition, the air conditioner expansion valve (61) is fully open, and the openings of the outdoor expansion valve (34), refrigerating expansion valve (71), and freezing expansion valve (83) are properly adjusted, and the first stage of the high-grade side hot gas passage (46) A solenoid valve (SV1) and a second solenoid valve (SV2) of the low-stage hot gas passage (89) are closed. In this state, the DC variable frequency compressor (31a), the first fixed frequency compressor (31b), the second fixed frequency compressor (31c), and the auxiliary compressor (85) are operated.

The refrigerant ejected by the DC variable frequency compressor (31a), the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) is commutated from the high pressure air pipe (45) and the first four-way The valve (35) and the second air pipe (51) are introduced into the air-conditioning heat exchanger (62) of the air-conditioning circuit (60) through the second gas-side connecting pipe (24) to dissipate heat and condense to the indoor air. In the air conditioner unit (12), the indoor air heated by the air conditioner heat exchanger (62) is supplied into the store. The refrigerant condensed in the air conditioner heat exchanger (62) flows through the second liquid side connecting pipe (23), and then is divided into the refrigerating side branch liquid pipe (21a), the freezing side branch liquid pipe (21b) and the first liquid side Contact piping (21).

The refrigerant flowing through the refrigerating side branch liquid pipe (21a) flows into the refrigerated display case (13), and the refrigerant flowing through the freezing side branch liquid pipe (21b) flows into the freezing display case (14). In the refrigerated display case (13) and the refrigerated display case (14), cooling of the air in the storage is carried out in the same manner as in the above-mentioned air-conditioning operation. The refrigerant evaporated in the refrigerating heat exchanger (72) and the refrigerant compressed in the auxiliary compressor (85) after evaporating in the freezing heat exchanger (84) join in the first gas side communication pipe (22). The refrigerant flowing through the first gas side connecting pipe (22) is divided into the first suction pipe (41a) and the second suction pipe (41b), and is sucked into the DC inverter compressor (31a) and the first fixed frequency compressor (31b ) are compressed.

[0125] The refrigerant flowing through the first liquid side communication pipe (21) flows into the receiver (33) from the third liquid pipe (55) and flows through the fourth liquid pipe (56) to be received by the outdoor expansion valve (34). stress reliever. The refrigerant depressurized by the outdoor expansion valve (34) is introduced into the outdoor heat exchanger (32), where it absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (32) passes through the first four-way reversing valve (35) and the second four-way reversing valve (36), from the second low-pressure air pipe (44) through the third suction pipe ( 41c) is sucked into the second constant frequency compressor (31c) to be compressed.

[0126] In this way, during heating operation, the refrigerant absorbs heat in the refrigerating heat exchanger (72), the freezing heat exchanger (84), and the outdoor heat exchanger (32), while the air-conditioning heat exchanger (62) Medium refrigerant heat dissipation. In addition, the heat absorbed by the refrigerant from the air in the storage in the refrigerating heat exchanger (72) and the freezing heat exchanger (84) and the heat absorbed by the refrigerant from the outdoor air in the outdoor heat exchanger (32) are utilized. , to heat the store.

And, when using the outdoor heat exchanger (32) as the heating capacity in the operation of the evaporator, the following operation can also be carried out: as shown in Figure 5, stop the second fixed-frequency compressor (31c) and close the outdoor The expansion valve (34) is in a state where the refrigerant absorbs heat in the refrigerating heat exchanger (72) and the freezing heat exchanger (84), and the refrigerant radiates heat in the air-conditioning heat exchanger (62).

And, when the heating energy is still surplus, in addition to converting the second four-way reversing valve (36) to the second state, the outdoor expansion valve (34) is converted to fully open for operation (at this time, the second constant frequency Compressor (31c) stops), with outdoor heat exchanger (32) as condenser, carry out the operation that emits unnecessary heat to the outside just get final product.

[0129] "Defrosting operation during heating"

As the defrosting operation during heating, the defrosting operation of FIG. 6 and the defrosting operation of FIG. 7 can be performed. The defrosting operation of FIG. Defrost; the defrost operation in Fig. 7 is to cool the refrigerating heat exchanger (84) and defrost the refrigerating heat exchanger (72) at the same time.

[0130] First, the defrosting operation of FIG. 6 will be described.

As shown in Figure 6, in the refrigerant circuit (20), the first four-way reversing valve (35) and the third four-way reversing valve (37) are set to the second state, and the second four-way The reversing valve (36) is set to the first state. And, the air-conditioning expansion valve (61), the refrigeration expansion valve (71) and the freezing expansion valve (83) are fully opened, and on the other hand, the opening degree of the outdoor expansion valve (34) is properly adjusted. The first solenoid valve (SV1) of the high-stage hot gas passage (46) and the second solenoid valve (SV2) of the low-stage hot gas passage (89) are opened. In this state, the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) are operated.

The refrigerant ejected by the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) merges in the high-pressure air pipe (45) through each ejection pipe (48b, 48c), and flows from the first The four-way reversing valve (35) and the second air pipe (51) are introduced into the outdoor heat exchanger (32) of the air conditioning circuit (60) through the second gas side connecting pipe (24) to radiate heat and condense to the indoor air. In the air conditioner unit (12), the indoor air heated by the air conditioner heat exchanger (62) is supplied into the store. The refrigerant condensed in the air conditioner heat exchanger (62) flows into the first liquid side communication pipe (21) after flowing through the second liquid side communication pipe (23).

On the other hand, part of the refrigerant ejected from the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) It flows through the first gas side communication pipe (22), and is divided into the refrigeration side branch gas pipe (22a) and the freezing side branch gas pipe (22b).

[0134] The refrigerant flowing through the refrigerating side branch air pipe (22a) flows into the refrigerating heat exchanger (72) to dissipate heat and condense to the air in the store. At this time, the frost adhering to the refrigeration heat exchanger (72) is melted. The refrigerant condensed in the refrigerating heat exchanger (72) passes through the refrigerating expansion valve (71), flows through the refrigerating side branch liquid pipe (21a), and flows into the first liquid side connecting pipe (21) and the refrigeration from the air conditioning unit (12). Confluence of agents.

[0135] The refrigerant flowing through the branch air pipe (22b) on the freezing side flows into the freezing heat exchanger (84) through the low-stage side hot gas passage (89), and radiates heat and condenses to the air in the storehouse. At this time, the frost adhering to the refrigeration heat exchanger (84) is melted. The refrigerant condensed in the refrigeration heat exchanger (84) flows through the refrigeration side branch liquid pipe (21b) through the refrigeration expansion valve (83), the water pan heater (82) and the refrigerant heat exchanger (81), and flows into The first liquid side communication pipe (21) joins the refrigerant from the air conditioning unit (12).

The refrigerant flowing through the first liquid side communication pipe (21) flows into the receiver (33) from the third liquid pipe (55), flows through the fourth liquid pipe (56) and is received by the outdoor expansion valve (34). stress reliever. The refrigerant depressurized by the outdoor expansion valve (34) is introduced into the outdoor heat exchanger (32), where it absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (32) passes through the first four-way reversing valve (35) and the second four-way reversing valve (36), from the second low-pressure air pipe (44) through the second suction pipe ( 41b) and the third suction pipe (41c) are sucked into the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) to be compressed.

[0137] As described above, in the defrosting operation shown in FIG. 6, refrigeration can be performed simultaneously using the heat absorbed by the outdoor heat exchanger (32) and the heat obtained by compressing the refrigerant in the compressors (31b, 31c). Defrost of heat exchanger (72) and refrigeration heat exchanger (84).

[0138] Also, although the operation of FIG. 6 shows the use of two of the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c), only one of the compressors may be operated.

[0139] And, when only the defrosting of the refrigeration heat exchanger (84) is performed, it is sufficient to close the refrigeration expansion valve (71) in the running state of FIG. 6 so that the refrigerant does not flow to the refrigeration showcase (13).

[0140] Next, the defrosting operation shown in FIG. 7 will be described.

As shown in Figure 7, in the refrigerant circuit (20), the first four-way reversing valve (35) and the third four-way reversing valve (37) are set to the second state, and the second four-way reversing valve (37) is set to the second state. The reversing valve (36) is set to the first state. Moreover, the air-conditioning expansion valve (61) and the refrigeration expansion valve (71) are fully opened, and the opening degrees of the refrigeration expansion valve (83) and the outdoor expansion valve (34) are properly adjusted. The first solenoid valve (SV1) of the high-stage hot gas passage (46) is opened, and the second solenoid valve (SV2) of the low-stage hot gas passage (89) is closed. In this state, the first fixed frequency compressor (31b), the second fixed frequency compressor (31c) and the auxiliary compressor (85) are operated.

The refrigerant ejected from the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) merges in the high-pressure air pipe (45) through each ejection pipe (48b, 48c), and flows from the first fixed-frequency compressor (31c) A four-way reversing valve (35) and the second air pipe (51) are introduced into the outdoor heat exchanger (32) of the air-conditioning circuit (60) through the second gas side connecting pipe (24) to radiate heat and condense to the indoor air. The air conditioner unit (12) supplies indoor air heated by the air conditioner heat exchanger (62) into the store. The refrigerant condensed in the air conditioner heat exchanger (62) flows through the second liquid side connecting pipe (23), and then is divided into the freezing side branch liquid pipe (21b) and the first liquid side connecting pipe (21).

The refrigerant flowing into the freezing circuit (80) from the freezing side branch liquid pipe (21b) passes through the refrigerant heat exchanger (81) and the water pan heater (82), and when passing through the freezing expansion valve (83) After being decompressed, it is introduced into the refrigeration heat exchanger (84). In the refrigeration heat exchanger (84), the refrigerant absorbs heat from the air in the store and evaporates. At this time, in the refrigeration heat exchanger (84), the evaporation temperature of the refrigerant is set at about -30°C, for example. In the refrigerated showcase (14), the air in the refrigerator cooled by the refrigerated heat exchanger (84) is supplied into the refrigerator, and the temperature in the refrigerator is maintained at, for example, about -20°C.

[0144] The refrigerant evaporated in the refrigeration heat exchanger (84) is sucked into the auxiliary compressor (85) through the suction pipe (88). The refrigerant compressed by the auxiliary compressor (85) flows from the discharge pipe (98) into the first gas side communication pipe (22) through the refrigeration side branch air pipe (22b). At this time, the opening degree of the electronic expansion valve (87) provided in the branch pipe (86) is controlled, and the economizer functions. Therefore, the discharge pressure of the auxiliary compressor (85) is increased to approximately the same level as the discharge pressures of the first constant frequency compressor (31b) and the second constant frequency compressor (31c).

On the other hand, part of the refrigerant ejected from the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) It flows through the first gas side connecting pipe (22), joins the refrigerant from the refrigerating unit (14), and flows to the refrigerating side branch gas pipe (22a).

The refrigerant flowing through the refrigerated side branch air pipe (22a) flows into the refrigerated heat exchanger (72) to radiate heat and condense to the air in the store. At this time, the frost adhering to the refrigeration heat exchanger (72) is melted. The refrigerant condensed in the refrigerating heat exchanger (72) passes through the refrigerating side of the refrigerating expansion valve (71), flows through the branch liquid pipe (21a), and then is diverted to the refrigerating side branch together with the refrigerant from the air conditioning unit (12). The liquid pipe (21b) and the first liquid side communication pipe (21).

The refrigerant flowing through the first liquid side communication pipe (21) flows into the receiver (33) from the third liquid pipe (55), flows through the fourth liquid pipe (56) and is received by the outdoor expansion valve (34). stress reliever. The refrigerant depressurized by the outdoor expansion valve (34) is introduced into the outdoor heat exchanger (32), where it absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (32) passes through the first four-way reversing valve (35) and the second four-way reversing valve (36), from the second low-pressure air pipe (44) through the second suction pipe ( 41b) and the third suction pipe (41c) are sucked into the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) to be compressed.

[0148] As described above, in the defrosting operation shown in FIG. 7, it is possible to use the heat absorbed by the outdoor heat exchanger (32) and the refrigeration heat exchanger (84) and compress the refrigerant in the compressors (31b, 31c). The heat of carrying out the defrosting of refrigeration heat exchanger (72).

[0149] And, although the operation of using two of the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) is shown in FIG. 7, it is also possible to operate only one of the compressors.

-First embodiment effect-

According to the refrigerating device (10) of the present embodiment, even if there is no defrosting mechanism such as an electric heater except the refrigerant circuit, both the refrigerating heat exchanger (72) and the refrigerating heat exchanger (84) can be defrosted, Therefore, it is possible to prevent the complexity of the device structure. In addition, not only defrosting both the refrigeration heat exchanger (72) and the freezing heat exchanger (84) can be performed simultaneously, but only one of them can be defrosted. Since defrosting can be performed on individual heat exchangers (72, 84) in this way, it is possible to cope with various defrosting operation patterns.

Further, the existing refrigerating device uses the refrigerating heat exchanger as a heat source to defrost the refrigerating heat exchanger, and must consider the good combination of heat absorption and heat dissipation of the refrigerating heat exchanger and the refrigerating heat exchanger during defrosting operation , while there are design limitations, relatively, the freezer (10) of this embodiment has no design limitations.

[0152] And, since the heat absorbed by the air conditioner heat exchanger (62) or the heat absorbed by the outdoor heat exchanger (32) and the heat obtained by compressing the refrigerant in the compression mechanism (31) are used to perform refrigeration heat The defrosting of the exchanger (72) and the refrigeration heat exchanger (84) can be performed efficiently.

Further, if the frost attached to the refrigerating heat exchanger (72) and the freezing heat exchanger (84) is melted from the outside with an electric heater, the temperature in the store is easy to rise, but since this embodiment uses the heat of the refrigerant Frost adhering to the refrigeration heat exchanger (72) and the refrigeration heat exchanger (84) is melted from the inside, thereby suppressing an increase in temperature in the refrigerator.

[0154] And, structurally, only the refrigerating heat exchanger (72) and the refrigerating heat exchanger (84) are defrosted at the same time, and the temperature in the storehouse will be lower if the heat exchanger that has been defrosted earlier continues to flow into the hot air. However, in this embodiment, each heat exchanger (72, 84) is used to perform defrosting separately, so one of the heat exchangers finishes defrosting first and can prevent the temperature in the refrigerator from rising by stopping the inflow of hot air.

Further, in the operation of only defrosting the refrigerated heat exchanger (72), the discharge of the auxiliary compressor (85) is increased due to the function of the economizer in the refrigerated showcase (14) pressure. When the economizer is not used, due to the large pressure difference between the discharge pressure of the compression mechanism (31) of the outdoor unit (11) and the discharge pressure of the auxiliary compressor (85), it may cause damage to the auxiliary compressor (85). Damage, however, can be prevented by using an economizer.

[0156] Also, in the present embodiment, although the description of the detailed flow of the refrigerant in the refrigerant circuit (20) is omitted, it is also possible to stop the air conditioner and only perform refrigeration/freezing operation, or to stop the refrigeration/freezing operation. Only the operation of the air conditioner is performed.

"Second Embodiment"

The freezing device (10) of the second embodiment, as shown in Fig. 8, differs from the first embodiment in the structure of a part of the outdoor unit (11). Specifically, the structure of the high-level side hot gas passage (46) is different from that of the first embodiment. In the second embodiment, one end of the hot gas introduction passage (46) is connected to the high-pressure air pipe (45), and the other end is connected to the fourth valve port (P4) of the third four-way reversing valve (37). Furthermore, in the first embodiment, the first communication pipe (43a) is provided with a check valve (CV1), but in the second embodiment, it is not provided.

[0158] The other structures are the same as those of the first embodiment.

-running action-

In the second embodiment, as in the first embodiment, it is possible to perform cooling operation and

In the heating operation, both or one of the refrigerating heat exchanger (72) and the freezing heat exchanger (84) can be defrosted during the cooling operation and the heating operation.

During air-conditioning operation, as shown in Figure 9, the first four-way reversing valve (35), the second four-way reversing valve (36) and the third four-way reversing valve (37) are respectively set to first state. In addition, the outdoor expansion valve (34) is fully closed, and the openings of the air-conditioning expansion valve (61), the refrigeration expansion valve (71), and the refrigeration expansion valve (83) are properly adjusted, and the first stage of the low-stage side hot gas passage (89) The second solenoid valve (SV2) is closed. In this state, the DC variable frequency compressor (31a), first fixed frequency compressor (31b), second fixed frequency compressor (31c), and auxiliary compressor (85) are activated.

Refrigerant circulates in the refrigerant circuit (10) identical with the state shown in Figure 2. Then, a refrigeration cycle is performed in which the outdoor heat exchanger (32) is used as a condenser, and the air-conditioning heat exchanger (62), the refrigeration heat exchanger (72), and the refrigeration heat exchanger (84) are used as evaporators.

As the defrosting operation during cold air, the defrosting operation of FIG. 10 and the defrosting operation of FIG. 11 can be performed. The defrosting operation of FIG. 84), the defrosting operation of Fig. 11 is to cool the freezing heat exchanger (84) and defrost the refrigeration heat exchanger (72) at the same time.

During the defrosting operation of Fig. 10, the first four-way reversing valve (35) and the second four-way reversing valve (36) are set to the first state, and the third four-way reversing valve (37) is set to the first state. ) is set to the second state. Simultaneously, the outdoor expansion valve (34) is fully closed, the refrigeration expansion valve (71) and the freezing expansion valve (83) are fully open, and the opening of the air conditioning expansion valve (61) is properly regulated. The second solenoid valve (SV2) of the low-stage side hot gas passage (89) is opened. In this state, the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) are operated.

[0164] Except that part of the refrigerant sprayed from the compression mechanism (31) of the outdoor unit (10) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) and the third four-way reversing valve (37) The refrigerant circulates in the refrigerant circuit (10) in the same manner as in the state shown in FIG. 3 except that it flows into the refrigerated showcase (13) and the refrigerated showcase (14). Then, a refrigeration cycle is performed in which the outdoor heat exchanger (32), the refrigerating heat exchanger (72), and the freezing heat exchanger (84) are used as condensers, and the air-conditioning heat exchanger (62) is used as an evaporator.

During the defrosting operation of Fig. 11, the first four-way reversing valve (35) and the second four-way reversing valve (36) are set to the first state, and the third four-way reversing valve (37) is set to the first state. ) is set to the second state. And, the outdoor expansion valve (34) is fully closed, the refrigerated expansion valve (71) is fully opened, and the openings of the freezing expansion valve (83) and the air conditioning expansion valve (61) are properly regulated. The second solenoid valve (SV2) of the low-stage side hot gas passage (89) is closed. In this state, the first fixed frequency compressor (31b), the second fixed frequency compressor (31c) and the auxiliary compressor (85) are operated.

[0166] Except that part of the refrigerant ejected from the compression mechanism (31) of the outdoor unit (10) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) and the third four-way reversing valve (37) ) flows to the refrigerated showcase (13), the refrigerant circulates in the refrigerant circuit (10) in the same state as shown in Fig. 4 . Then, a refrigeration cycle is performed in which the outdoor heat exchanger (32) and the refrigeration heat exchanger (72) are used as condensers, and the air-conditioning heat exchanger (62) and the refrigeration heat exchanger (84) are used as evaporators.

When heating is running, as shown in Figure 12, the first four-way reversing valve (35) is set to the second state, and the second four-way reversing valve (36) is switched to the third four-way The valve (37) is set to the first state. And, the air-conditioning expansion valve (61) is fully opened, and the openings of the outdoor expansion valve (34), the refrigeration expansion valve (71), and the refrigeration expansion valve (83) are properly regulated. The second solenoid valve (SV2) of the low-stage side hot gas passage (89) is closed. In this state, the DC variable frequency compressor (31a), first fixed frequency compressor (31b), second fixed frequency compressor (31c) and auxiliary compressor (85) are operated.

[0168] The refrigerant circulates in the refrigerant circuit (10) in the same manner as in the state shown in FIG. 5 . And, a refrigeration cycle is performed in which the outdoor heat exchanger (32) is used as a condenser, and the air-conditioning heat exchanger (62), the refrigeration heat exchanger (72), and the refrigeration heat exchanger (84) are used as evaporators.

And, if the heating capacity is excessive during the operation with the outdoor heat exchanger (32) as the evaporator, then the following operation can be carried out in the state as shown in Figure 12, that is: stop the second fixed-frequency compressor (31c ) while closing the outdoor expansion valve (34), the refrigerant absorbs heat in the refrigerating heat exchanger (72) and the freezing heat exchanger (84), and the refrigerant dissipates heat in the air-conditioning heat exchanger (62).

And, if the heating capacity is still excessive, then the second four-way reversing valve (36) is switched to the second state and the outdoor expansion valve (34) is switched to the fully open state to operate (stop the second Fixed-frequency compressor (31c)), with outdoor heat exchanger (32) as condenser, unnecessary heat is removed to the outside and just gets final product.

As the defrosting operation during heating, the defrosting operation as shown in Figure 13 and the defrosting operation as in Figure 14 can be carried out, and the defrosting operation in Figure 13 is to simultaneously operate the refrigerating heat exchanger (72) and the freezing heat exchanger ( 84) Perform defrosting. The defrosting operation in FIG. 14 is to cool the refrigeration heat exchanger (84) and defrost the refrigeration heat exchanger (72).

During the defrosting operation of Fig. 13, the first four-way reversing valve (35) and the third four-way reversing valve (37) are set to the second state, and the second four-way reversing valve (36) ) is set to the first state. And, the air-conditioning expansion valve (61), the refrigeration expansion valve (71) and the freezing expansion valve (83) are fully opened, and the opening degree of the outdoor expansion valve (34) is properly adjusted. The second solenoid valve (SV2) of the low-stage side hot gas passage (89) is opened. In this state, the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) are operated.

[0173] Except that part of the refrigerant ejected from the compression mechanism (31) of the outdoor unit (10) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) and the third four-way reversing valve (37) The refrigerant circulates in the refrigerant circuit (10) in the same state as shown in FIG. 6 except that it flows to the refrigerated showcase (13) and the refrigerated showcase (14). Then, a refrigeration cycle is performed in which the air-conditioning heat exchanger (62), the refrigeration heat exchanger (72), and the freezing heat exchanger (84) are used as condensers, and the outdoor heat exchanger (32) is used as an evaporator.

During the defrosting operation of Fig. 14, the first four-way reversing valve (35) and the third four-way reversing valve (37) are set to the second state, and the second four-way reversing valve (36) is set to the second state. ) is set to the first state. Moreover, the air-conditioning expansion valve (61) and the refrigeration expansion valve (71) are fully opened, and the opening degrees of the refrigeration expansion valve (83) and the outdoor expansion valve (34) are properly adjusted. The second solenoid valve (SV2) of the low-stage side hot gas passage (89) is closed. In this state, the first fixed frequency compressor (31b), the second fixed frequency compressor (31c) and the auxiliary compressor (85) are operated.

[0175] Except that part of the refrigerant ejected from the compression mechanism (31) of the outdoor unit (10) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) and from the third four-way reversing valve (37). ) flows to the refrigerated showcase (13), the refrigerant circulates in the refrigerant circuit (10) in the same manner as in the state shown in Fig. 7 . Then, a refrigeration cycle is performed in which the air-conditioning heat exchanger (62) and the refrigeration heat exchanger (72) are used as condensers, and the refrigeration heat exchanger (84) and the outdoor heat exchanger (32) are used as evaporators.

-Effect of the second embodiment-

The refrigerating apparatus (10) of the second embodiment can cope with various defrosting operation forms while suppressing the complexity of the apparatus structure as in the first embodiment. In addition, unlike existing refrigeration devices that use the refrigeration heat exchanger as a heat source to defrost the refrigeration heat exchanger, there is no need to consider the good combination of heat absorption and heat dissipation during the defrosting operation of the refrigeration heat exchanger and the refrigeration heat exchanger. It is not limited in design, which is the same as that of the first embodiment.

Further, due to the heat absorbed by the air-conditioning heat exchanger (62) and the outdoor heat exchanger (32), and the heat obtained by compressing the refrigerant in the compression mechanism (31), the refrigeration heat exchanger (72 ) and the refrigerating heat exchanger (84) for defrosting, so efficient defrosting operation can be performed, and the heat of the refrigerant can melt and adhere to the refrigerating heat exchanger (72) and refrigerating heat exchange from the inside without using an electric heater The frost of device (84) can suppress the rise of temperature in the store, etc. These points are also the same as the first embodiment.

"The third embodiment"

The freezing device (10) of the third embodiment, as shown in Figure 15, is connected with an air conditioner unit (12) and two refrigerating units (14) for the outdoor unit (11) to replace the outdoor unit (11). Each of an air-conditioning unit (12), a refrigerated display case (13) and a refrigerated display case (14) are replaced. Two refrigerated display cabinets (14), through two refrigerated side branched liquid pipes (21b) branched from the first liquid side connecting pipe (21), and two branched from the first gas side connecting pipe (22) The refrigerated side diverges the air pipe (22b) and is connected to the outdoor unit (11) in parallel. In other words, in the third embodiment, two refrigeration circuits (80) including a refrigeration heat exchanger (84) and an auxiliary compressor (85) are connected in parallel.

[0179] Other structures are the same as those of the first embodiment.

-running action-

In this third embodiment, cooling operation and heating operation can be performed similarly to the first and second embodiments, and one or two refrigeration heat exchangers (84) can be removed during cooling operation and heating operation. Frost.

During air-conditioning operation, as shown in Figure 16, the first four-way reversing valve (35), the second four-way reversing valve (36) and the third four-way reversing valve (37) are set to first state. Moreover, the outdoor expansion valve (34) is fully closed, the openings of the air conditioning expansion valve (61) and the refrigeration expansion valve (83) are properly adjusted, and the second solenoid valve (SV2) of the low-stage hot gas passage (89) is closed. In this state, the DC variable frequency compressor (31a), the first fixed frequency compressor (31b), the second fixed frequency compressor (31c) and the auxiliary compressors (85) are activated.

[0182] In substantially the same state as shown in FIG. 2 , the refrigerant circulates in the refrigerant circuit (10). And, a refrigeration cycle is performed in which the outdoor heat exchanger (32) is used as a condenser, and the air-conditioning heat exchanger (62) and the refrigeration heat exchanger (84) are used as evaporators.

The defrosting operation during air-conditioning can carry out the defrosting operation of Fig. 17 and the defrosting operation of Fig. 18, and the defrosting operation of Fig. 17 is to defrost two refrigeration heat exchangers (84) simultaneously, Fig. 18 The defrosting operation is to cool one of the refrigeration heat exchangers (84) and defrost the other refrigeration heat exchanger (84).

During the defrosting operation of Fig. 17, the first four-way reversing valve (35) and the second four-way reversing valve (36) are set to the first state, and the third four-way reversing valve ( 37) Set to the second state. And, the outdoor expansion valve (34) is fully closed, and each refrigeration expansion valve (83) is fully opened, and the opening degree of the air conditioner expansion valve (61) is properly adjusted. The first solenoid valve (SV1) of the high-stage hot gas passage (46) and the second solenoid valve (SV2) of the low-stage hot gas passage (89) are respectively opened. In this state, the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) are operated.

[0185] Except that part of the refrigerant sprayed from the compression mechanism (31) of the outdoor unit (10) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) and then diverts to two refrigerated side branch air pipes (22b ) to each refrigerated showcase (14), the refrigerant circulates in the refrigerant circuit (10) in the same manner as in the state shown in Fig. 3 . Then, a refrigeration cycle is performed in which the outdoor heat exchanger (32) and each refrigeration heat exchanger (84) are used as condensers, and the air conditioner heat exchanger (62) is used as an evaporator.

[0186] The defrosting operation of FIG. 18 is an example of defrosting the refrigerated display case (14) on the upper side as shown in the figure. In the following description, this refrigerated showcase (14) is called a defrosting-side showcase, and the refrigerated showcase on the lower side of the figure is called a cooling-side showcase.

In Fig. 18, the first four-way reversing valve (35) and the second four-way reversing valve (36) are set to the first state, and the third four-way reversing valve (37) is set to into the second state. Moreover, the outdoor expansion valve (34) is fully closed. On the other hand, the openings of the refrigeration expansion valve (83) and the air conditioning expansion valve (61) of the cooling side showcase are properly adjusted, and the refrigeration expansion valve of the defrosting side showcase is closed. (83) is fully open. The first solenoid valve (SV1) of the high-level hot gas passage (46) is opened, the second solenoid valve (SV2) of the low-stage hot gas passage (89) of the defrosting side showcase is opened, and the low-stage hot gas of the cooling side showcase The second solenoid valve (SV2) of the passage (89) is closed. In this state, the first fixed frequency compressor (31b), the second fixed frequency compressor (31c) and the auxiliary compressor (85) of the cooling side showcase are operated.

Except that part of the refrigerant sprayed from the compression mechanism (31) of the outdoor unit (10) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) and then flows to the refrigerating heat exchange of the display cabinet on the defrosting side The refrigerant circulates in the refrigerant circuit (10) in the same manner as in the state shown in Fig. 4 except for this point of the device (84). And, carry out with the refrigerating heat exchanger (84) of outdoor heat exchanger (32) and defrosting side showcase as condenser, with the refrigerating heat exchanger (84) of air-conditioning heat exchanger (62) and cooling side showcase Refrigeration cycle for the evaporator.

When heating is running, as shown in Figure 19, the first four-way reversing valve (35) is set to the second state respectively, and the second four-way reversing valve (36) is switched to the third four-way reversing valve The valve (37) is set to the first state. And, the air conditioner expansion valve (61) is fully opened, and the opening degrees of the outdoor expansion valve (34) and each refrigeration expansion valve (83) are properly adjusted. The first solenoid valve (SV1) of the high-stage hot gas passage (46) and the second solenoid valve (SV2) of the low-stage hot gas passage (89) are closed. In this state, the DC variable frequency compressor (31a), the first fixed frequency compressor (31b), the second fixed frequency compressor (31c) and the auxiliary compressors (85) are operated.

[0190] The refrigerant circulates in the refrigerant circuit (10) in substantially the same state as shown in FIG. 5 . And, a refrigeration cycle is performed in which the air-conditioning heat exchanger (62) is used as a condenser, and the outdoor heat exchanger (32) and the refrigeration heat exchanger (84) are used as evaporators.

And, when using the outdoor heat exchanger (32) as the heating capacity in the operation of the evaporator, the second constant frequency compressor (31c) is stopped in the state of Figure 19 and the outdoor expansion valve (34) is closed at the same time. The refrigerant absorbs heat in each refrigeration heat exchanger (84), and the operation may be performed in a state where the refrigerant dissipates heat in the air-conditioning heat exchanger (62).

And, when the heating capacity is excessive, switch the second four-way reversing valve (36) to the second state and simultaneously switch the outdoor expansion valve (34) to fully open for operation (at this time, the second fixed-frequency compressor (31c) stops), with outdoor heat exchanger (32) as condenser, unnecessary heat is got rid of to the outside and just gets final product.

As the defrosting operation during heating, the defrosting operation of FIG. 20 and the defrosting operation of FIG. 21 can be carried out. The defrosting operation of FIG. 20 is to defrost two refrigeration heat exchangers (84) at the same time. The defrosting operation of 21 is to cool one of the refrigeration heat exchangers (84) and to defrost the other refrigeration heat exchanger (84).

[0194] During the defrosting operation of Fig. 20, the first four-way reversing valve (35) and the third four-way reversing valve (37) are set to the second state, and the second four-way reversing valve ( 36) Set to the first state. Moreover, the air-conditioning expansion valve (61) and each refrigeration expansion valve (83) are fully opened, and the opening degree of the outdoor expansion valve (34) is properly adjusted. The first solenoid valve (SV1) of the high-stage hot gas passage (46) and the second solenoid valve (SV2) of the low-stage hot gas passage (89) are opened. In this state, the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) are operated.

[0195] Except that part of the refrigerant ejected from the compression mechanism (31) of the outdoor unit (10) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) and then diverts to the two refrigerated side branch air pipes ( 22b) The refrigerant circulates in the refrigerant circuit (10) in the same manner as in the state shown in FIG. 6 except that it flows to each refrigerated showcase (14). Then, a refrigeration cycle is performed in which the air-conditioning heat exchanger (62) and each refrigeration heat exchanger (84) are used as condensers, and the outdoor heat exchanger (32) is used as an evaporator.

[0196] The defrosting operation in FIG. 21 is an example in which defrosting is performed on the refrigerated showcase (14) on the upper side as shown in the figure. During this defrosting operation, the first four-way selector valve (35) and the third four-way selector valve (37) are set to the second state, and the second four-way selector valve (36) is set to the second state. a state. And, the refrigerated expansion valve (83) of cooling side showcase and the opening degree of outdoor expansion valve (34) are properly regulated, and the refrigerated expansion valve (83) of air-conditioning expansion valve (61) and defrosting side showcase is fully opened. The first solenoid valve (SV1) of the high-level side hot gas passage (46) is fully open, the second solenoid valve (SV2) of the low-stage side hot gas passage (89) of the defrosting side showcase is open, and the low-stage side of the cooling side showcase The second solenoid valve (SV2) of the hot gas passage (89) is closed. In this state, the first fixed frequency compressor (31b), the second fixed frequency compressor (31c) and the auxiliary compressor (85) of the cooling side showcase are operated.

Except that part of the refrigerant ejected from the compression mechanism (31) of the outdoor unit (10) passes through the first low-pressure air pipe (42) from the high-grade side hot gas passage (46) and then flows to the defrosting side showcase Except for this point of the exchanger (84), the refrigerant circulates in the refrigerant circuit (10) in the same manner as in the state shown in Fig. 7 . And, use the air-conditioning heat exchanger (62) and the refrigeration heat exchanger (84) of the defrosting side showcase as the condenser, and the refrigeration heat exchanger (84) and the outdoor heat exchanger (32) of the cooling side showcase Refrigeration cycle for the evaporator.

-Effect of the third embodiment-

The refrigerating apparatus (10) of the third embodiment can cope with various forms of defrosting operation while suppressing the complexity of the apparatus structure as in the first and second embodiments. In particular, when one of the two refrigeration heat exchangers (84) is defrosted, the other refrigeration heat exchanger (84) can be cooled. In addition, it is the same as the first and second embodiments, which avoids design restrictions that must be considered to combine the heat absorption and heat dissipation of the refrigeration heat exchanger and the freezing heat exchanger during the defrosting operation.

Further, since the heat absorbed by the air conditioner heat exchanger (62) or the outdoor heat exchanger (32) and the heat obtained by compressing the refrigerant in the compression mechanism (31) can be used to refrigerate the heat exchanger (84) performs defrosting, so efficient defrosting operation can be performed, or the heat of the refrigerant can melt the frost adhering to the refrigerating heat exchanger (84) from the inside without using an electric heater, thereby suppressing the rise of the internal temperature etc. These aspects are also the same as those in the first and second embodiments.

"Fourth Embodiment"

The refrigeration system (10) of the fourth embodiment has basically the same structure as the refrigerant circuit (20) of the above-mentioned first embodiment, but differs in the operation of the defrosting operation.

In this example, during the defrosting operation of the refrigeration heat exchanger (84), after the auxiliary compressor (85) further compresses the refrigerant ejected from the compression mechanism (31) of the outdoor circuit (30), the The discharged refrigerant is supplied to the refrigeration heat exchanger (84). Specifically, part of the refrigerant discharged from the compression mechanism (31) of the outdoor circuit (30) is supplied to the refrigeration heat exchanger (84) through the low-stage hot gas passage (89), and the other part is supplied to the auxiliary compressor ( 85) After being compressed, it merges with the refrigerant flowing through the above-mentioned compression mechanism (31) in the low-stage hot gas passage (89), and is supplied to the refrigeration heat exchanger (84).

[0202] During the defrosting operation, part of the refrigerant liquid condensed in the refrigeration heat exchanger (84) is injected into the auxiliary compressor (85).

In the fourth embodiment, the hot gas introduction path (46, 89) is divided into the first introduction path (96) and the second introduction path (97), and the first introduction path (96) is the outdoor circuit (30) The gas refrigerant ejected from the compression mechanism (31) is introduced into the auxiliary compressor (85), and the second introduction passage (97) is used to introduce the gas refrigerant ejected from the auxiliary compressor (85) into the cooling heat exchanger (84 ). The second introduction passage (97) is connected to the compression mechanism (31) of the outdoor circuit (30) and the cooling heat exchanger (84) (the second introduction passage (97) is a passage including the low-stage hot gas passage (89)). On the other hand, the first introduction passage (96) is branched from the second introduction passage (97) and connected with the auxiliary compressor (85), so as to refrigerate the gas ejected by the compression mechanism (31) of the outdoor circuit (30). Part of the agent is directed to the auxiliary compressor (85). In addition, a discharge pipe (98) of an auxiliary compressor (85) is connected to the compression mechanism (31) side of the outdoor circuit (30) of the second introduction passage (97).

In this fourth embodiment, the branch pipe (86) connected to the low-pressure side flow path (81b) of the refrigerant heat exchanger (81) forms a liquid injection path (99), and the liquid injection path (99) is to During the defrosting operation of the refrigeration heat exchanger (84), part of the liquid refrigerant flowing out of the cooling heat exchanger (84) is introduced into the auxiliary compressor (85).

-operation action-

Regarding the operation of the fourth embodiment, the defrosting operation of the refrigeration heat exchanger (84) during the cooling operation will be described.

The refrigerating apparatus (10) of the 4th embodiment, performs the defrosting operation shown in Fig. 3 (the first defrosting operation) of switching over the first embodiment, and the defrosting operation (the second defrosting operation) of Fig. 22 described later. frost operation). These two defrosting operations are switched according to the temperature detected by the heat exchanger temperature sensor (90) provided in the refrigeration heat exchanger (84).

[0207] In this freezing device (10), the first defrosting operation as shown in FIG. 3 is usually performed. In this first defrosting operation, as described above, in addition to operating the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) of the outdoor circuit (30), the DC inverter compressor (31a) and auxiliary The compressor (85) is stopped, and the refrigeration heat exchanger (72) and the refrigeration heat exchanger (84) are defrosted.

On the other hand, if the defrosting capacity of the refrigerating heat exchanger (84) is insufficient during the first defrosting operation, and the time required for defrosting the refrigerating heat exchanger (84) becomes longer, the The following second defrosting operation.

[0209] Specifically, when the temperature detected by the heat exchanger temperature sensor (90) is difficult to rise to a predetermined temperature during the above-mentioned first defrosting operation, it is judged that the defrosting capability of the refrigeration heat exchanger (84) is insufficient. As a result, the first defrosting operation is shifted to the second defrosting operation.

In the second defrosting operation, as in the first defrosting operation, in the refrigerant circuit (20), the first four-way reversing valve (35) and the second four-way reversing valve (36 ) is set to the first state, and the third four-way reversing valve (37) is set to the second state. And, the outdoor expansion valve (34) is fully closed, the refrigeration expansion valve (71) and the freezing expansion valve (83) are fully open, and the opening degree of the air conditioning expansion valve (61) is properly regulated. Then, the first solenoid valve (SV1) of the high-stage hot gas passage (46) and the second solenoid valve (SV2) of the low-stage hot gas passage (89) are opened. In this state, the first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) are operated. Simultaneously, the opening degree of the electronic expansion valve (87) as the branch pipe (86) of the liquid injection passage (99) is adjusted, and the auxiliary compressor (85) is activated.

In this state, the refrigerant ejected by the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) merges in the high-pressure air pipe (45) through each ejection pipe (48b, 48c) , is sent to the outdoor heat exchanger (32) from the first four-way reversing valve (35) by the first air pipe (50). In the outdoor heat exchanger (32), the refrigerant dissipates heat and condenses to the outdoor air. The refrigerant condensed in the outdoor heat exchanger (32) flows into the second liquid side communication pipe (23) after passing through the first liquid side communication pipe (21) of the receiver (33).

On the other hand, part of the refrigerant ejected from the first fixed-frequency compressor (31b) and the second fixed-frequency compressor (31c) flows through the first low-pressure air pipe ( 42) Connect with the first gas side piping (22), and branch into the refrigerating side branch gas pipe (22a) and the freezing side branch gas pipe (22b).

[0213] The refrigerant flowing to the branch air pipe (22a) on the refrigerating side flows into the refrigerating heat exchanger (72) to radiate heat and condense to the air in the store. At this time, the frost adhering to the refrigeration heat exchanger (72) is melted. The refrigerant condensed in the refrigeration heat exchanger (72) flows into the refrigeration side branch liquid pipe (21a) through the refrigeration expansion valve (71), and then flows into the second liquid side connecting pipe (23) and the refrigerant from the outdoor unit (11) confluence.

[0214] The refrigerant flowing to the branched air pipe (22b) on the freezing side passes through the second introduction passage (97) including the low-stage hot gas passage (89), a part of it flows into the refrigeration heat exchanger (84), and the other part passes through the first The introduction passage (96) is sucked into the auxiliary compressor (85).

The refrigerant compressed in the auxiliary compressor (85) is sent to the low-stage side hot gas passage (89) through the discharge pipe (98), and is discharged by the compression mechanism (31) of the above-mentioned outdoor circuit (30). refrigerant confluence. And, the refrigerant merged in the low-stage hot gas passage (89) flows into the refrigeration heat exchanger (84). In other words, in the refrigeration circuit (80), part of the refrigerant circulates while being compressed by the auxiliary compressor (85), and the input heat of the auxiliary compressor (80) is supplied to the refrigerant.

[0216] In the refrigeration heat exchanger (84), the refrigerant radiates heat and condenses to the air in the storehouse. At this time, the frost adhering to the refrigeration heat exchanger (84) is melted. The refrigerant condensed in the refrigeration heat exchanger (84) flows into the first refrigeration side branch liquid pipe (21b) through the refrigeration expansion valve (83), the water pan heater (82), and the refrigeration side branch liquid pipe (21b) of the refrigerant heat exchanger (81). The two liquid side communication pipes (23) merge with the refrigerant from the outdoor unit (11).

[0217] During this second defrosting operation, since the auxiliary compressor (85) further compresses a part of the refrigerant compressed by the compression mechanism (31) of the outdoor circuit (30), if this operation is continued, the auxiliary The temperature of the refrigerant discharged from the compressor (85) increases significantly, which may cause a failure. Therefore, the refrigeration system (10) in the fourth embodiment performs a liquid injection operation in order to prevent failure of the auxiliary compressor (85).

[0218] Specifically, during the second defrosting operation, the opening degree of the electronic expansion valve (87) is adjusted in response to the temperature of the refrigerant discharged from the auxiliary compressor (85). Also, for example, when the temperature of the discharged refrigerant is higher than a predetermined value, the opening degree of the electronic expansion valve (87) is increased. As a result, part of the refrigerant condensed in the refrigeration heat exchanger (84) is sent to the auxiliary compressor (85) through the branch pipe (86) as the liquid injection passage (99). Therefore, the refrigerant sucked into the auxiliary compressor (85) is cooled, and an abnormal increase in temperature of the refrigerant discharged from the auxiliary compressor (85) can be prevented.

[0219] On the other hand, the refrigerant joined in the second liquid-side communication pipe (23) is supplied to the air-conditioning circuit (60). Subsequent operations are the same as in the example shown in FIG. 3 . In other words, the refrigerant flowing into the air-conditioning circuit (60) is decompressed when passing through the air-conditioning expansion valve (61), and then introduced into the air-conditioning heat exchanger (62). In the air conditioner heat exchanger (62), the refrigerant absorbs heat from the room air and evaporates. In the air conditioner unit (12), indoor air cooled by the air conditioner heat exchanger (62) is supplied into the store. The refrigerant evaporated in the air conditioner heat exchanger (62) flows into the outdoor circuit (30) through the second gas side connecting pipe (24), and sequentially passes through the first four-way reversing valve (35) from the second gas pipe (51) and the second four-way reversing valve (36), it is sucked into the first fixed-frequency compressor (31b) and the second Two constant frequency compressors (31c). The first fixed frequency compressor (31b) and the second fixed frequency compressor (31c) compress the sucked refrigerant and discharge it to the second discharge pipe (48b) and the third discharge pipe (48c).

[0220] As described above, in the defrosting operation of FIG. 22, the heat absorbed by the indoor heat exchanger (62), and the compressors (31b, 31c) and the refrigeration circuit (80) of the outdoor circuit (30) are used. ) can defrost the refrigeration heat exchanger (72) and the refrigeration heat exchanger (84) at the same time. In addition, the same operation as that shown in FIG. 4 is also possible, and the operation in which only the refrigeration heat exchanger (84) is defrosted by closing the refrigeration expansion valve (71) is also possible.

[0221] In addition, the description of the defrosting operation of the refrigeration heat exchanger (84) during the heating operation is omitted.

-Effect of the fourth embodiment-

In addition to obtaining the same effect as the first embodiment, the fourth embodiment also

It has the following effects.

[0223] In other words, in the fourth embodiment, the first defrosting operation and the second defrosting operation can be switched, and when the defrosting capacity of the refrigeration heat exchanger (84) is insufficient in the first defrosting operation, The second defrosting operation in which the auxiliary compressor (85) is operated can be performed. Therefore, according to the fourth embodiment, the amount of heat given to the refrigerant in the second defrosting operation can be increased, and the defrosting capability of the refrigeration heat exchanger (84) can be improved. Therefore, the refrigeration heat exchanger (84) can be effectively defrosted by the second defrosting operation.

[0224] Furthermore, in the above-mentioned fourth embodiment, in the second defrosting operation, since the liquid is injected into the auxiliary compressor (85), it is possible to prevent the temperature of the refrigerant discharged from the auxiliary side compressor (85) from rising abnormally, Securely protect the auxiliary compressor (85).

-Modified example of the fourth embodiment-

In the above-mentioned fourth embodiment, the branch pipe (86) as the liquid injection passage (99) is connected to the intermediate pressure position of the auxiliary compressor (85), but this branch pipe (86) can also be connected to the auxiliary compressor (8). The first introduction passage (96) of the suction pipe.

Also, in the above-mentioned fourth embodiment, due to liquid injection, the discharge temperature of the auxiliary compressor (85) will not rise abnormally, but it is also possible to control the operation capacity of the auxiliary compressor (85) to replace this liquid injection. In this way, an abnormal increase in the discharge temperature of the auxiliary compressor (85) can be suppressed.

"The fifth embodiment"

The refrigeration device (10) of the fifth embodiment, as shown in FIG. structure is also changed. Hereinafter, differences between the fifth embodiment and the first embodiment will be mainly described. Also, in this embodiment, sensors and the like are omitted.

[0228] In the fifth embodiment, regarding the outdoor unit (11), although the high-pressure introduction pipe (47) shown in FIG. 1 is not shown, in order to introduce the high-pressure pressure of the refrigerant circuit (20) The fourth valve port (P4) of the four-way reversing valve (37) is therefore provided identically with the first embodiment.

In the refrigerating showcase (14), the refrigerant heat exchanger (81) is not provided, and the gas side piping (110 (88)) of the refrigerating heat exchanger (84) is connected to the suction side of the auxiliary compressor (85) . The discharge pipe (98) of the auxiliary compressor (85) is provided with an oil separator (120), and a capillary tube is connected between the oil separator (120) and the suction pipe (111) of the auxiliary compressor (85). (121) oil return pipe (122). In addition, a detour pipe (125) bypassing the auxiliary compressor (85) is connected to the suction pipe (111) and the discharge pipe (98) of the auxiliary compressor (85) when the auxiliary compressor (85) fails or the like. A check valve (CV10) is provided in this detour piping (125).

[0230] As a feature of the fifth embodiment, different from the first embodiment, the hot gas introduction path (100) is not provided with a high-level side and a low-level side respectively, and the compression mechanism (31) connected to the outdoor unit (11) ) of the discharge pipe (high-pressure gas pipe) (45) and a pipe (110) on the gas side of the refrigerating heat exchanger (84). An electronic expansion valve (101) is provided as a flow rate adjustment mechanism in this hot gas introduction passage (100).

And, not just hot gas import passage (100) is connected refrigeration heat exchanger (84), as shown in dotted line in Figure 23, above-mentioned hot gas import passage (100) is set by branch pipe (hot gas import passage) (102 ) is also connected to the piping (112) on the gas side of the refrigeration heat exchanger (72), and a switching mechanism (103) such as a three-way valve can also be provided, and the switching mechanism (103) such as a three-way valve can switch or select the hot gas flow to the refrigeration The heat exchanger (84) and the hot air flow to the refrigerated heat exchanger (72). In this way, it is possible to defrost both the refrigerating heat exchanger (72) and the freezing heat exchanger (84) at the same time or defrost one of them. Therefore, similarly to each of the above-mentioned embodiments, each heat exchanger (72, 84) can be individually defrosted to correspond to various defrosting operation modes.

[0232] For example, during the defrosting operation of the refrigeration heat exchanger (84), part of the refrigerant ejected from the compression mechanism (31) of the outdoor unit (11) flows through the hot gas introduction passage (100) and is introduced into the refrigeration unit (100). heat exchanger (84). In the refrigerated heat exchanger (84), the warmth of the high-pressure refrigerant melts the adhering frost. Thereafter, the refrigerant evaporates in the refrigeration heat exchanger (72), the air conditioner heat exchanger (62), or the outdoor heat exchanger (32), and is sucked into the compression mechanism (31). In this case, when the electronic expansion valve (101) is fully open, the refrigerant flow rate is large, so it can be considered that the frost attached to the refrigeration heat exchanger (84) melts at once around the coil, and leaves a However, if the flow rate of the refrigerant is adjusted by adjusting the opening of the above-mentioned electronic expansion valve (101), the frost can be gradually melted around the coil to prevent the frost from falling to the merchandise.

[0233] In addition, the operations during the air-conditioning operation and the heating operation of the fifth embodiment are substantially the same as those of the above-mentioned respective embodiments, and description thereof will be omitted here.

"Other Embodiments"

Regarding the above-mentioned embodiments, the following configurations are possible.

For example, in the first and second embodiments, an air-conditioning unit (12), a refrigerated display cabinet (13) and a refrigerated display cabinet (14) connected to each other are used as an example for illustration, but the air-conditioning unit (14) can also be appropriately changed. The number of units (12), refrigerated showcases (13), and freezer showcases (14).

[0236] And, in the third embodiment, an example in which one air conditioner unit (12) and two refrigerated showcases (14) are connected to the outdoor unit (11) has been described, but the refrigerated showcase (14) can also be More than three.

And, although in any one of the first to third embodiments, when the air-conditioning of the store is carried out with a dedicated air conditioner, the refrigeration unit (10) of each embodiment may not be provided with an air-conditioning unit (12) .

[0238] Moreover, although the compression mechanism (31) of the outdoor unit (11) is composed of three compressors (31a, 31b, 31c) in each of the above-mentioned embodiments, the number of compressors can also be changed without Under the situation that air-conditioning unit (12) is set, also can make compressor be one.

[0239] In addition, the above-mentioned fourth embodiment is to improve the defrosting operation effect by using the auxiliary compressor (85) when performing the defrosting operation on the refrigerating heat exchanger (84) in the first embodiment. It can be applied to the second embodiment and the third embodiment. Also, in the fourth embodiment, during the second defrosting operation, part of the refrigerant discharged from the compression mechanism (31) of the outdoor unit (11) can be supplied to the refrigeration heat exchanger (84), and the other can be supplied to the cooling heat exchanger (84). A part of the refrigerant is supplied to the auxiliary compressor (85) while circulating the refrigerant, however, it is also possible to supply all of the refrigerant discharged from the compression mechanism (31) to the auxiliary compressor (85) and compress it before supplying to refrigeration heat exchanger (84).

[0240] Moreover, the above embodiments are preferred examples in nature, and are not intended to limit the present invention, the application of the present invention or the scope of use of the present invention.

Industrial Applicability

As explained above, the present invention is very useful for the following refrigerating apparatus: that is, a refrigerating apparatus having a refrigerant circuit of a vapor compression refrigeration cycle composed of an outdoor heat exchanger and a compression mechanism. The outdoor circuit is composed of a plurality of cooling circuits with cooling heat exchangers in series, and the sub-compressor of the cooling circuit of at least one system of the refrigeration device is connected with cooling heat exchangers in series.

Claims (14)

1. refrigerating plant, this refrigerating plant possesses the refrigerant loop (20) that carries out the steam compression type refrigerating circulation, this refrigerant loop (20) is to have cooling heat exchanger (72 respectively by being connected in parallel in the outdoor loop (30) that is provided with outdoor heat converter (32) and compressing mechanism (31), the cooling circuit (70 of a plurality of systems 84), 80) constitute, in the cooling circuit (80) of at least one system, auxiliary compressor (85) and cooling heat exchanger (84) are connected in series, it is characterized in that:

Have hot gas and import path (46,89) (100,102), this hot gas importing path (46,89) (100,102) optionally imports many cooling heat exchangers (72 with the ejection gas refrigerant of the compressing mechanism (31) of outdoor loop (30), 84) at least one, and possessing the defrosting path (25) that can defrost and turn round, this defrosting path (25) is carried out kind of refrigeration cycle with above-mentioned cooling heat exchanger (72,84) as condenser.

2. refrigerating plant according to claim 1 is characterized in that:

Be connected in parallel to first cooling circuit (70) that possesses first cooling heat exchanger (72) and have second cooling heat exchanger (84) and second cooling circuit (80) of auxiliary compressor (85) in outdoor loop (30).

3. refrigerating plant according to claim 1 is characterized in that:

Be connected in parallel to many cooling circuits (80) of possess cooling heat exchanger (84) and auxiliary compressor (85) in outdoor loop (30).

4. refrigerating plant according to claim 1 is characterized in that:

Be connected with air heat exchanger loop (60) in outdoor loop (30), this air heat exchanger loop (60) has the air heat exchanger (62) of regulating air themperature;

It constitutes described refrigerating plant and can carry out the first defrosting running and second defrosting is turned round, the first defrosting running is with cooling heat exchanger (72,84) be evaporimeter for condenser with air heat exchanger (62), the second defrosting running is evaporimeter for condenser with outdoor heat converter (32) with cooling heat exchanger (72,84).

5. refrigerating plant according to claim 1 is characterized in that:

Hot gas imports path (46,89) and has possessed senior side hot gas path (46) and rudimentary side hot gas path (89); Bleed pipe (45) and each cooling circuit (70 of the compressing mechanism (31) of senior side hot gas path (46) junction chamber external loop (30), the parent tube (42) of low pressure tracheae 80), when the defrosting running, allow cold-producing medium to flow to each cooling heat exchanger (72,84) from the bleed pipe (45) of above-mentioned compressor structure (31); The bleed pipe (22b) of rudimentary side hot gas path (89) auxiliary connection compressor (85) and suction line (88) allow cold-producing medium to flow to the cooling heat exchanger (84) that connects this auxiliary compressor (85) from the bleed pipe (22b) of auxiliary compressor (85) when the defrosting running.

6. refrigerating plant according to claim 5 is characterized in that:

This refrigerating plant possesses: as the compressing mechanism (31) of outdoor loop (30) and first compressor (31a), second compressor (32b) and the 3rd compressor (31c) that are connected in parallel, the four-way change-over valve (37) that connects the suction side of this compressing mechanism (31), be located at the senior side switch valve (SV1) of senior side hot gas path (46), and the rudimentary side switch valve (SV2) of being located at rudimentary side hot gas path (89);

The suction line (41a) of first compressor (31a) is by first valve port (P1) of non-return valve (CV1) connection four-way change-over valve (37), and this non-return valve (CV1) is forbidden this first compressor (31a) of refrigerant flow direction;

The suction line (41b) of second compressor (32b) connects second valve port (P2) of four-way change-over valve (37);

The suction line (41c) of the 3rd compressor (31c) is by the 3rd valve port (P3) of non-return valve (CV2) connection four-way change-over valve (37), and this non-return valve (CV2) is forbidden refrigerant flow direction the 3rd compressor (31c);

The high pressure ingress pipe (47) that is communicated with the high-voltage tube of compressing mechanism (31) connects the 4th valve port (P4) of four-way change-over valve (37);

Senior side hot gas path (46) connects the suction line (41a) of first compressor (31a);

It constitutes first state that can convert to and second state four-way change-over valve (37), first state is communicated with the 3rd valve port (P3) and the 4th valve port (P4) simultaneously for being communicated with first valve port (P1) and second valve port (P2), and second state is communicated with second valve port (P2) and the 3rd valve port (P3) simultaneously for being communicated with first valve port (P1) and the 4th valve port (P4).

7. refrigerating plant according to claim 5 is characterized in that:

This refrigerating plant possesses: as the compressing mechanism (31) of outdoor loop (30) and first compressor (31a), second compressor (32b) and the 3rd compressor (31c) that are connected in parallel, connect the four-way change-over valve (37) of the suction side of this compressing mechanism (31), and the rudimentary side switch valve (SV2) of being located at rudimentary side hot gas path (89);

The suction line (41a) of first compressor (31a) connects first valve port (P1) of four-way change-over valve (37);

The suction line (41b) of second compressor (32b) connects second valve port (P2) of four-way change-over valve (37);

The suction line (41c) of the 3rd compressor (31c) is by the 3rd valve port (P3) of non-return valve (CV2) connection four-way change-over valve (37), and this non-return valve (CV2) is forbidden refrigerant flow direction the 3rd compressor (31c);

Senior side hot gas path (46) connects the 4th valve port (P4) of four-way change-over valve (37);

It constitutes first state that can convert to and second state four-way change-over valve (37), first state is communicated with second valve port (P2) and the 3rd valve port (P3) simultaneously for being communicated with first valve port (P1) and the 4th valve port (P4), and second state is communicated with the 3rd valve port (P3) and the 4th valve port (P4) simultaneously for being communicated with first valve port (P1) and second valve port (P2).

8. refrigerating plant according to claim 1 is characterized in that:

Hot gas imports path (46,89) and possesses the first importing path (96) and the second importing path (97); First imports path (96) makes the ejection gas refrigerant of the compressing mechanism (31) of outdoor loop (30) import auxiliary compressor (85); Second imports path (97) makes the ejection gas refrigerant of auxiliary compressor (85) import cooling heat exchanger (84).

9. refrigerating plant according to claim 8 is characterized in that:

Second imports the compressing mechanism (31) and the cooling heat exchanger (84) of path (97) junction chamber external loop (30); And

First imports path (96) imports path (97) difference and goes out auxiliary connection compressor (85) from second, makes the part of ejection gas refrigerant of compressing mechanism (31) of outdoor loop (30) import auxiliary compressor (85);

Be connected with the bleed pipe (98) of auxiliary compressor (85) in above-mentioned second compressing mechanism (31) one sides that import the outdoor loop (30) of path (97).

10. refrigerating plant according to claim 9 is characterized in that:

Have liquid and inject path (99), the part that this liquid injects the liquid refrigerant that path (99) will flow out from cooling heat exchanger (84) imports auxiliary compressor (85).

11. refrigerating plant according to claim 9 is characterized in that:

Auxiliary compressor (85) is made of frequency-changeable compressor.

12. refrigerating plant according to claim 1 is characterized in that:

At least one pipe in the pipe arrangement (110,112) of the bleed pipe (45) of the compressing mechanism (31) of the direct junction chamber external loop (30) of hot gas importing path (100,102) and the gas side of cooling heat exchanger (72,84).

13. refrigerating plant according to claim 12 is characterized in that:

Hot gas imports path (100,102) be connected with bleed pipe (45) and many cooling heat exchangers (72 of the compressing mechanism (31) of outdoor loop (30), the pipe arrangement (110 of gas side 84), 112), this refrigerating plant possesses the switching mechanism (103) that can change or select many cooling heat exchangers (72,84).

14. refrigerating plant according to claim 12 is characterized in that:

Import path (100,102) at hot gas and be provided with flow guiding mechanism (101).

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