JP6835176B1 - Refrigeration equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the switching frequency of a flow path switching mechanism. A refrigerant circuit (6) is provided in an intermediate pressure section (21a) between a first compression section (21) and a second compression section (22, 23) in a first refrigeration cycle and the second refrigeration cycle. It has an intermediate flow path (41) for introducing a refrigerant and an intercooler (17) for cooling the refrigerant flowing through the intermediate flow path (41) with a heat medium. The first refrigeration cycle is a refrigeration cycle in which the heat source heat exchanger (13) is stopped, the first utilization heat exchanger (54) is used as a radiator, and the second utilization heat exchanger (64) is used as an evaporator. The second refrigeration cycle is a refrigeration cycle in which the heat source heat exchanger (13) and the first utilization heat exchanger (54) are used as radiators and the second utilization heat exchanger (64) is used as an evaporator. The controller (100) increases the cooling capacity of the intercooler (17) when the condition indicating that the heating capacity of the first utilization heat exchanger (54) is excessive is satisfied in the first refrigeration cycle. [Selection diagram] FIG. 7

Description

The present disclosure relates to a refrigeration system.

The refrigerant circuit of the refrigerating apparatus disclosed in Patent Document 1 includes a compression element, a heat source heat exchanger (outdoor heat exchanger), a first utilization heat exchanger (indoor heat exchanger), and a second utilization heat exchanger (cooling heat). Exchanger) and flow path switching mechanism are connected.

When the refrigerating apparatus is heated, the first refrigeration cycle, the second refrigeration cycle, and the third refrigeration cycle are performed by the flow path switching mechanism. The first refrigeration cycle is a refrigeration cycle in which the heat source heat exchanger is stopped, the first utilization heat exchanger is used as a radiator, and the second utilization heat exchanger is used as an evaporator. The second refrigeration cycle is a refrigeration cycle in which the heat source heat exchanger and the first utilization heat exchanger are used as radiators and the second utilization heat exchanger is used as an evaporator. The third refrigeration cycle is a refrigeration cycle in which the first utilization heat exchanger is used as a radiator, and the heat source heat exchanger and the second utilization heat exchanger are used as evaporators.

Japanese Unexamined Patent Publication No. 2004-44921

In a refrigerating apparatus as described in Patent Document 1, when switching each refrigeration cycle, the flow path of the refrigerant is switched by the flow path switching mechanism. Specifically, for example, when the heating capacity is excessive in the first refrigeration cycle, the flow path switching mechanism switches the flow path of the refrigerant to shift from the first refrigeration cycle to the second refrigeration cycle. However, it is preferable that the switching frequency of the flow path switching mechanism is as low as possible.

An object of the present disclosure is to reduce the switching frequency of the flow path switching mechanism.

The first aspect is a compression element (C) including a first compression unit (21) and a second compression unit (22, 23) connected in series, a heat source heat exchanger (13), and a first utilization heat. It has a exchanger (54), a second heat exchanger (64), and a flow path switching mechanism (30), and at least the first refrigeration cycle and the second refrigeration are performed by switching the flow path switching mechanism (30). and configured refrigerant circuit to perform a cycle (6), a refrigeration system including a controller (100), the refrigerant circuit (6), the first compression unit before Symbol (21) said first It has an intermediate flow path (41) connecting the two compression units (22, 23) and an intermediate cooler (17) for cooling the refrigerant flowing through the intermediate flow path (41) with a heat medium. The refrigeration cycle is a refrigeration cycle in which the heat source heat exchanger (13) is stopped, the first utilization heat exchanger (54) is used as a radiator, and the second utilization heat exchanger (64) is used as an evaporator. The second refrigeration cycle is a refrigeration cycle in which the heat source heat exchanger (13) and the first utilization heat exchanger (54) are used as radiators and the second utilization heat exchanger (64) is used as an evaporator. When the condition indicating that the heating capacity of the first utilization heat exchanger (54) is excessive is satisfied in the first refrigeration cycle, the controller (100) of the intermediate cooler (17) Increase cooling capacity.

In the first aspect, when the condition indicating that the heating capacity is excessive is satisfied in the first refrigeration cycle, the cooling capacity of the intercooler (17) is increased and the heating capacity is reduced. Therefore, the heating capacity can be reduced without switching to the second refrigeration cycle.

The second aspect is a condition indicating that, in the first aspect, the controller (100) has an excessive heating capacity of the first utilization heat exchanger (54) in the first refrigeration cycle. When both the condition indicating that the cooling capacity of the intercooler (17) is equal to or higher than a predetermined value is satisfied, the flow path switching mechanism (30) is controlled so as to perform the second refrigeration cycle.

In the second aspect, it is possible to suppress switching to the second refrigeration cycle in the first refrigeration cycle until the cooling capacity of the intercooler (17) exceeds a predetermined value.

In a third aspect, in the first or second aspect, the controller (100) is said to be the first while the intercooler (17) is cooling the refrigerant during the second refrigeration cycle. 1 When the condition indicating that the heating capacity of the utilization heat exchanger (54) is insufficient is satisfied, the cooling capacity of the intercooler (17) is reduced.

In the third aspect, when the condition indicating that the heating capacity is insufficient is satisfied in the second refrigeration cycle, the cooling capacity of the intercooler (17) is reduced and the heating capacity is increased. Therefore, the heating capacity can be increased without switching to the first refrigeration cycle.

A fourth aspect is a condition indicating that the controller (100) lacks the heating capacity of the first utilization heat exchanger (54) in the second refrigeration cycle in the third aspect. When both the condition indicating that the cooling capacity of the intercooler (17) is equal to or less than a predetermined value is satisfied, the flow path switching mechanism (30) is controlled so as to perform the first refrigeration cycle.

In the fourth aspect, it is possible to suppress switching to the first refrigeration cycle in the second refrigeration cycle until the cooling capacity of the intercooler (17) becomes equal to or less than a predetermined value.

In a fifth aspect, in any one of the first to fourth aspects, the refrigerant circuit (6) is configured to perform a third refrigeration cycle by switching the flow path switching mechanism (30). The third refrigeration cycle is a refrigeration cycle in which the first utilization heat exchanger (54) is used as a radiator and the heat source heat exchanger (13) and the second utilization heat exchanger (64) are used as evaporators. , the controller (100), when said intercooler (17) is performing the cooling of the refrigerant in the first refrigeration cycle, the heating capacity of the first utilization heat exchanger (54) is insufficient When the condition indicating that is satisfied, the cooling capacity of the intercooler (17) is reduced.

In the fifth aspect, when the condition indicating that the heating capacity is insufficient is satisfied in the first refrigeration cycle, the cooling capacity of the intercooler (17) is reduced and the heating capacity is increased. Therefore, the heating capacity can be increased without switching to the third refrigeration cycle.

A sixth aspect is a condition indicating that, in the fifth aspect, the controller (100) lacks the heating capacity of the first utilization heat exchanger (54) in the first refrigeration cycle, and the above. When both the condition that the cooling capacity of the intercooler (17) is equal to or less than a predetermined value is satisfied, the flow path switching mechanism (30) is controlled so as to perform the third refrigeration cycle.

In the sixth aspect, switching to the third refrigeration cycle can be suppressed until the cooling capacity of the intercooler (17) becomes equal to or less than a predetermined value in the first refrigeration cycle.

A seventh aspect, in a fifth or sixth aspect, indicates that the controller (100) has an excessive heating capacity of the first utilization heat exchanger (54) in the third refrigeration cycle. When the conditions are satisfied, the cooling capacity of the intercooler (17) is increased.

In the seventh aspect, when the condition indicating that the heating capacity is excessive is satisfied in the third refrigeration cycle, the cooling capacity of the intercooler (17) is increased and the heating capacity is reduced. Therefore, the heating capacity can be reduced without switching to the first refrigeration cycle.

In the eighth aspect, in the seventh aspect, the condition indicating that the controller (100) has an excessive heating capacity of the first utilization heat exchanger (54) in the third refrigeration cycle, and the above-mentioned When both the conditions that the cooling capacity of the intercooler (17) is equal to or higher than a predetermined value are satisfied, the flow path switching mechanism (30) is controlled so as to perform the first refrigeration cycle.

In the eighth aspect, it is possible to suppress switching to the first refrigeration cycle in the third refrigeration cycle until the cooling capacity of the intercooler (17) exceeds a predetermined value.

A ninth aspect further comprises, in any one of the first to eighth aspects, an intermediate fan (17a) that carries air as the heat medium that cools the refrigerant flowing through the intermediate flow path (41). The controller (100) adjusts the cooling capacity by adjusting the air volume of the intermediate fan (17a).

FIG. 1 is a piping system diagram of the refrigerating device according to the embodiment. FIG. 2 is a view corresponding to FIG. 1 showing the flow of the refrigerant in the cold operation. FIG. 3 is a view corresponding to FIG. 1 showing the flow of the refrigerant in the cooling operation. FIG. 4 is a view corresponding to FIG. 1 showing the flow of the refrigerant in the cooling / cooling operation. FIG. 5 is a view corresponding to FIG. 1 showing the flow of the refrigerant in the heating operation. FIG. 6 is a view corresponding to FIG. 1 showing the flow of the refrigerant in the heating / cooling operation. FIG. 7 is a view corresponding to FIG. 1 showing the flow of the refrigerant in the heating / cooling heat recovery operation. FIG. 8 is a view corresponding to FIG. 1 showing the flow of the refrigerant in the heating / cooling residual heat operation. FIG. 9 is a state transition diagram for explaining the control of switching between the heating / cooling heat recovery operation, the heating / cooling residual heat operation, and the heating / cooling operation, and the control of the air volume of the cooling fan in each operation. ..

Hereinafter, this embodiment will be described with reference to the drawings. It should be noted that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses.

<< Embodiment >>
<overall structure>
The refrigerating apparatus (1) according to the embodiment cools the object to be cooled and air-conditions the room at the same time. The cooling target here includes air in equipment such as refrigerators, freezers, and showcases. Hereinafter, such equipment will be referred to as cold equipment.

As shown in FIG. 1, the refrigerating device (1) includes an outdoor unit (10) installed outdoors, an indoor unit (50) that air-conditions the room, and a cooling unit (60) that cools the air inside the refrigerator. ) And the controller (100). FIG. 1 illustrates two indoor units (50) connected in parallel. The refrigerating apparatus (1) may have one indoor unit (50) or three or more indoor units (50) connected in parallel. In FIG. 1, one cooling unit (60) is illustrated. The refrigeration system (1) may have two or more cooling units (60) connected in parallel. The refrigerant circuit (6) is configured by connecting these units (10,50,60) with four connecting pipes (2,3,4,5).

The four connecting pipes (2,3,4,5) are the first liquid connecting pipe (2), the first gas connecting pipe (3), the second liquid connecting pipe (4), and the second gas connecting pipe (2). It consists of 5). The first liquid connecting pipe (2) and the first gas connecting pipe (3) correspond to the indoor unit (50). The second liquid connecting pipe (4) and the second gas connecting pipe (5) correspond to the cooling unit (60).

In the refrigerant circuit (6), the refrigeration cycle is performed by circulating the refrigerant. The refrigerant of the refrigerant circuit (6) of the present embodiment is carbon dioxide. The refrigerant circuit (6) is configured to perform a refrigeration cycle in which the refrigerant exceeds the critical pressure.

<Outdoor unit>
The outdoor unit (10) is a heat source unit installed outdoors. The outdoor unit (10) has an outdoor fan (12) and an outdoor circuit (11). The outdoor circuit (11) includes a compression element (C), a flow path switching mechanism (30), an outdoor heat exchanger (13), an outdoor expansion valve (14), a receiver (15), a cooling heat exchanger (16), and an intermediate. It has a cooler (17) and a cooling fan (17a).

<Compression element>
The compression element (C) compresses the refrigerant. The compression element (C) has a first compressor (21), a second compressor (22), and a third compressor (23). The compression element (C) is configured as a two-stage compression type. The second compressor (22) and the third compressor (23) constitute a low-stage compressor. The second compressor (22) and the third compressor (23) are connected in parallel with each other. The first compressor (21) constitutes a high-stage compressor. The first compressor (21) and the second compressor (22) are connected in series. The first compressor (21) and the third compressor (23) are connected in series. The first compressor (21) constitutes the first compression unit, and the second compressor (22) and the third compressor (23) form the second compression unit. The first compressor (21), the second compressor (22), and the third compressor (23) are rotary compressors in which a compression mechanism is driven by a motor. The first compressor (21), the second compressor (22), and the third compressor (23) are configured in a variable capacitance type in which the operating frequency or the rotation speed can be adjusted.

A first suction pipe (21a) and a first discharge pipe (21b) are connected to the first compressor (21). A second suction pipe (22a) and a second discharge pipe (22b) are connected to the second compressor (22). A third suction pipe (23a) and a third discharge pipe (23b) are connected to the third compressor (23). The first suction pipe (21a) constitutes an intermediate pressure portion between the first compression portion (21) and the second compression portion (22, 23).

The second suction pipe (22a) communicates with the cooling unit (60). The second compressor (22) is a cold side compressor corresponding to the cold unit (60). The third suction pipe (23a) communicates with the indoor unit (50). The third compressor (23) is an indoor compressor corresponding to the indoor unit (50).

<Flow path switching mechanism>
The flow path switching mechanism (30) switches the flow path of the refrigerant. The flow path switching mechanism (30) includes the first pipe (31), the second pipe (32), the third pipe (33), the fourth pipe (34), the first three-way valve (TV1), and the second three-way valve. Has (TV2). The inflow end of the first pipe (31) and the inflow end of the second pipe (32) are connected to the first discharge pipe (21b). The first pipe (31) and the second pipe (32) are pipes on which the discharge pressure of the compression element (C) acts. The outflow end of the third pipe (33) and the outflow end of the fourth pipe (34) are connected to the third suction pipe (23a) of the third compressor (23). The third pipe (33) and the fourth pipe (34) are pipes on which the suction pressure of the compression element (C) acts.

The first three-way valve (TV1) has a first port (P1), a second port (P2), and a third port (P3). The first port (P1) of the first three-way valve (TV1) is connected to the outflow end of the first pipe (31) which is a high-pressure flow path. The second port (P2) of the first three-way valve (TV1) is connected to the inflow end of the third pipe (33), which is a low-pressure flow path. The third port (P3) of the first three-way valve (TV1) is connected to the indoor gas side flow path (35).

The second three-way valve (TV2) has a first port (P1), a second port (P2), and a third port (P3). The first port (P1) of the second three-way valve (TV2) is connected to the outflow end of the second pipe (32), which is a high-pressure flow path. The second port (P2) of the second three-way valve (TV2) is connected to the inflow end of the fourth pipe (34), which is a low-pressure flow path. The third port (P3) of the second three-way valve (TV2) is connected to the outdoor gas side flow path (36).

The first three-way valve (TV1) and the second three-way valve (TV2) are electric three-way valves. Each of the three-way valves (TV1, TV2) switches between a first state (a state shown by a solid line in FIG. 1) and a second state (a state shown by a broken line in FIG. 1). In each of the three-way valves (TV1 and TV2) in the first state, the first port (P1) and the third port (P3) communicate with each other, and the second port (P2) is closed. In each of the three-way valves (TV1, TV2) in the second state, the second port (P2) and the third port (P3) communicate with each other, and the first port (P1) is closed.

<Outdoor heat exchanger>
The outdoor heat exchanger (13) constitutes a heat source heat exchanger. The outdoor heat exchanger (13) is a fin-and-tube type air heat exchanger. The outdoor fan (12) is located near the outdoor heat exchanger (13). The outdoor fan (12) carries outdoor air. The outdoor heat exchanger exchanges heat between the refrigerant flowing inside the outdoor heat exchanger and the outdoor air carried by the outdoor fan (12).

An outdoor gas side flow path (36) is connected to the gas end of the outdoor heat exchanger (13). An outdoor flow path (O) is connected to the liquid end of the outdoor heat exchanger (13).

<Outdoor flow path>
The outdoor flow path (O) is the outdoor first pipe (o1), the outdoor second pipe (o2), the outdoor third pipe (o3), the outdoor fourth pipe (o4), the outdoor fifth pipe (o5), and the outdoor pipe. Includes 6 pipes (o6) and 7 outdoor pipes (o7). One end of the outdoor first pipe (o1) is connected to the liquid end of the outdoor heat exchanger (13). One end of the outdoor second pipe (o2) and one end of the outdoor third pipe (o3) are connected to the other end of the outdoor first pipe (o1). The other end of the outdoor second pipe (o2) is connected to the top of the receiver (15). One end of the outdoor fourth pipe (o4) is connected to the bottom of the receiver (15). One end of the outdoor fifth pipe (o5) and the other end of the outdoor third pipe (o3) are connected to the other end of the outdoor fourth pipe (o4). The other end of the outdoor fifth pipe (o5) is connected to the second liquid connecting pipe (4). One end of the outdoor sixth pipe (o6) is connected in the middle of the outdoor fifth pipe (o5). The other end of the outdoor sixth pipe (o6) is connected to the first liquid connecting pipe (2). One end of the outdoor seventh pipe (o7) is connected in the middle of the outdoor sixth pipe (o6). The other end of the outdoor seventh pipe (o7) is connected in the middle of the outdoor second pipe (o2).

<Outdoor expansion valve>
The outdoor expansion valve (14) is connected to the outdoor first pipe (o1). The outdoor expansion valve (14) is a pressure reducing mechanism for reducing the pressure of the refrigerant. The outdoor expansion valve (14) is a heat source expansion valve. The outdoor expansion valve (14) is an electronic expansion valve having a variable opening.

<Receiver>
The receiver (15) constitutes a container for storing the refrigerant. At the receiver (15), the refrigerant is separated into a gas refrigerant and a liquid refrigerant. The other end of the outdoor second pipe (o2) and one end of the degassing pipe (37) are connected to the top of the receiver (15). The other end of the degassing pipe (37) is connected in the middle of the injection pipe (38). A degassing valve (39) is connected to the degassing pipe (37). The degassing valve (39) is an electronic expansion valve having a variable opening.

<Cooling heat exchanger>
The cooling heat exchanger (16) cools the refrigerant (mainly liquid refrigerant) separated by the receiver (15). The cooling heat exchanger (16) has a first refrigerant flow path (16a) and a second refrigerant flow path (16b). The first refrigerant flow path (16a) is connected in the middle of the outdoor fourth pipe (o4). The second refrigerant flow path (16b) is connected in the middle of the injection pipe (38).

One end of the injection pipe (38) is connected in the middle of the outdoor fifth pipe (o5). The other end of the injection pipe (38) is connected to the first suction pipe (21a) of the first compressor (21). In other words, the other end of the injection tube (38) is connected to the intermediate pressure portion of the compression element (C). The injection pipe (38) is provided with a pressure reducing valve (40) on the upstream side of the second refrigerant flow path (16b). The pressure reducing valve (40) is an expansion valve having a variable opening degree.

In the cooling heat exchanger (16), the refrigerant flowing through the first refrigerant flow path (16a) and the refrigerant flowing through the second refrigerant flow path (16b) exchange heat. The refrigerant decompressed by the pressure reducing valve (40) flows through the second refrigerant flow path (16b). Therefore, in the cooling heat exchanger (16), the refrigerant flowing through the first refrigerant flow path (16a) is cooled.

<Intercooler>
The intercooler (17) is connected to the intermediate flow path (41). One end of the intermediate flow path (41) is connected to the second discharge pipe (22b) of the second compressor (22) and the third discharge pipe (23b) of the third compressor (23). The other end of the intermediate flow path (41) is connected to the first suction pipe (21a) of the first compressor (21). In other words, the other end of the intermediate flow path (41) is connected to the intermediate pressure portion of the compression element (C).

The intercooler (17) is a fin-and-tube type air heat exchanger. A cooling fan (17a), which is an intermediate fan, is arranged in the vicinity of the intercooler (17). The intercooler (17) cools the refrigerant in the intermediate flow path (41) with a heat medium. The cooling fan (17a) conveys air as a heat medium for cooling the refrigerant in the intermediate flow path (41) to the intercooler (17). Specifically, the cooling fan (17a) conveys the outdoor air so that the outdoor air passes through the intercooler (17). In the intercooler (17), the refrigerant flowing inside the intercooler (17) exchanges heat with the outdoor air carried by the cooling fan (17a).

<Oil separation circuit>
The outdoor circuit (11) includes an oil separation circuit (42). The oil separation circuit (42) includes an oil separator (43), a first oil return pipe (44), a second oil return pipe (45), and a third oil return pipe (46). The oil separator (43) is connected to the first discharge pipe (21b) of the first compressor (21). The oil separator (43) separates the oil from the refrigerant discharged from the compression element (C). The inflow end of the first oil return pipe (44) communicates with the oil separator (43). The outflow end of the first oil return pipe (44) is connected to the second suction pipe (22a) of the second compressor (22). The inflow end of the second oil return pipe (45) communicates with the oil separator (43). The outflow end of the second oil return pipe (45) is connected to the inflow end of the intermediate flow path (41). The third oil return pipe (46) has a main return pipe (46a), a cold side branch pipe (46b), and an indoor side branch pipe (46c). The inflow end of the main return pipe (46a) communicates with the oil separator (43). The inflow end of the cold side branch pipe (46b) and the inflow end of the indoor side branch pipe (46c) are connected to the outflow end of the main return pipe (46a). The outflow end of the cold side branch pipe (46b) communicates with the oil sump in the casing of the second compressor (22). The outflow end of the indoor branch pipe (46c) communicates with the oil sump in the casing of the third compressor (23).

The first oil amount control valve (47a) is connected to the first oil return pipe (44). A second oil amount control valve (47b) is connected to the second oil return pipe (45). A third oil amount control valve (47c) is connected to the cold side branch pipe (46b). A fourth oil amount control valve (47d) is connected to the indoor branch pipe (46c).

The oil separated by the oil separator (43) is returned to the second compressor (22) via the first oil return pipe (44). The oil separated by the oil separator (43) is returned to the third compressor (23) via the second oil return pipe (45). The oil separated by the oil separator (43) is returned to the oil sump in each casing of the second compressor (22) and the third compressor (23) via the third oil return pipe (46). ..

<Check valve>
The outdoor circuit (11) includes a first check valve (CV1), a second check valve (CV2), a third check valve (CV3), a fourth check valve (CV4), and a fifth check valve (CV5). ), A sixth check valve (CV6), and a seventh check valve (CV7). The first check valve (CV1) is connected to the first discharge pipe (21b). The second check valve (CV2) is connected to the second discharge pipe (22b). The third check valve (CV3) is connected to the third discharge pipe (23b). The fourth check valve (CV4) is connected to the outdoor second pipe (o2). The fifth check valve (CV5) is connected to the outdoor third pipe (o3). The sixth check valve (CV6) is connected to the outdoor sixth pipe (o6). The 7th check valve (CV7) is connected to the outdoor 7th pipe (o7). These check valves (CV1 to CV7) allow the flow of the refrigerant in the direction of the arrow shown in FIG. 1 and prohibit the flow of the refrigerant in the direction opposite to the arrow.

<Indoor unit>
The indoor unit (50) is a utilization unit installed indoors. The indoor unit (50) has an indoor fan (52) and an indoor circuit (51). The first liquid connecting pipe (2) is connected to the liquid end of the indoor circuit (51). The first gas connecting pipe (3) is connected to the gas end of the indoor circuit (51).

The indoor circuit (51) has an indoor expansion valve (53) and an indoor heat exchanger (54) in this order from the liquid end to the gas end. The indoor expansion valve (53) is the first utilization expansion valve. The indoor expansion valve (53) is an electronic expansion valve having a variable opening.

The indoor heat exchanger (54) is the first utilization heat exchanger. The indoor heat exchanger (54) is a fin-and-tube type air heat exchanger. The indoor fan (52) is located in the vicinity of the indoor heat exchanger (54). The indoor fan (52) carries indoor air. The indoor heat exchanger (54) exchanges heat between the refrigerant flowing inside the indoor heat exchanger (54) and the indoor air carried by the indoor fan (52).

<Colding unit>
The cooling unit (60) is a utilization unit that cools the inside of the refrigerator. The cooling unit (60) has a cooling fan (62) and a cooling circuit (61). The second liquid connecting pipe (4) is connected to the liquid end of the cooling circuit (61). A second gas connecting pipe (5) is connected to the gas end of the cooling circuit (61).

The cold circuit (61) has a cold expansion valve (63) and a cold heat exchanger (64) in this order from the liquid end to the gas end. The cold expansion valve (63) is a second-use expansion valve. The cold expansion valve (63) is composed of an electronic expansion valve having a variable opening.

The cold heat exchanger (64) is a second-utilization heat exchanger. The cold heat exchanger (64) is a fin-and-tube air heat exchanger. The cold fan (62) is located in the vicinity of the cold heat exchanger (64). The cold fan (62) conveys the air inside the refrigerator. The cold heat exchanger (64) exchanges heat between the refrigerant flowing inside the cold heat exchanger (64) and the air inside the refrigerator carried by the cold fan (62).

<Sensor>
The refrigerating device (1) has various sensors. The various sensors include a high pressure pressure sensor (71), a high pressure temperature sensor (72), a refrigerant temperature sensor (73), and an indoor temperature sensor (74). The high-pressure pressure sensor (71) detects the pressure of the discharged refrigerant (pressure of the high-pressure refrigerant (HP)) of the first compressor (21). The high-pressure temperature sensor (72) detects the temperature of the discharged refrigerant (high-pressure refrigerant temperature (Td)) of the first compressor (21). The refrigerant temperature sensor (73) detects the temperature (Th2) of the outlet refrigerant of the indoor heat exchanger (54) in a state of being a radiator. The indoor temperature sensor (74) detects the temperature (indoor temperature (Ti)) of the indoor air in the target space (indoor space) of the indoor unit (50).

Physical quantities detected by other sensors (not shown) include the temperature of the high-pressure refrigerant, the temperature / pressure of the low-pressure refrigerant, the temperature / pressure of the intermediate-pressure refrigerant, the temperature of the refrigerant of the outdoor heat exchanger (13), and the cold heat exchanger. (64) Refrigerant temperature, 2nd compressor (22) suction refrigerant superheat, 3rd compressor (23) suction refrigerant superheat, 1st to 3rd compressors (C1, C2, C3) The degree of overheating of the discharged refrigerant, the temperature of the outdoor air, the temperature of the internal air, etc. can be mentioned.

<controller>
The controller (100), which is a controller, includes a microcomputer mounted on a control board and a memory device (specifically, a semiconductor memory) for storing software for operating the microcomputer. The controller (100) controls each device of the refrigerating device (1) based on the operation command and the detection signal of the sensor. The operation of the refrigerating device (1) is switched by the control of each device by the controller (100).

The controller (100) adjusts the cooling capacity of the intercooler (17) in the heating / cooling heat recovery operation, the heating / cooling residual heat operation, and the heating / cooling operation. Specifically, the controller (100) is an intercooler by adjusting the air volume of the cooling fan (17a) in the heating / cooling heat recovery operation, the heating / cooling residual heat operation, and the heating / cooling operation. Adjust the cooling capacity of (17). The details of this control will be described later.

-Driving operation-
The operating operation of the refrigerating apparatus (1) will be described in detail. The operation of the refrigerating device (1) includes cooling operation, cooling operation, cooling / cooling operation, heating operation, heating / cooling operation, heating / cooling heat recovery operation, heating / cooling residual heat operation, and defrost operation. Including.

In the cold operation, the cold unit (60) is operated and the indoor unit (50) is stopped. In the cooling operation, the cooling unit (60) is stopped and the indoor unit (50) cools. In the cooling / cooling operation, the cooling unit (60) is operated and the indoor unit (50) cools. In the heating operation, the cooling unit (60) is stopped and the indoor unit (50) is heated. In all of the heating / cooling operation, the heating / cooling heat recovery operation, and the heating / cooling residual heat operation, the cooling unit (60) is operated and the indoor unit (50) heats. In the defrost operation, the cooling unit (60) is operated to melt the frost on the surface of the outdoor heat exchanger (13).

The heating / cooling operation is performed under conditions where the required heating capacity of the indoor unit (50) is relatively large. The heating / cooling residual heat operation is performed under conditions where the required heating capacity of the indoor unit (50) is relatively small. The heating / cooling heat recovery operation is performed under the condition that the required heating capacity of the indoor unit (50) is between the heating / cooling operation (the condition where the cooling and the heating are balanced).

<Cold operation>
In the cold operation shown in FIG. 2, the first three-way valve (TV1) is in the second state and the second three-way valve (TV2) is in the first state. The outdoor expansion valve (14) is opened at a predetermined opening, the opening of the cold expansion valve (63) is adjusted by superheat control, the indoor expansion valve (53) is fully closed, and the pressure reducing valve (40) is opened. The opening degree is adjusted as appropriate. The outdoor fan (12), the cooling fan (17a), and the cooling fan (62) are operated, and the indoor fan (52) is stopped. The first compressor (21) and the second compressor (22) are operated, and the third compressor (23) is stopped. In the cold operation, a refrigeration cycle is performed in which the refrigerant compressed by the compression element (C) dissipates heat in the outdoor heat exchanger (13) and evaporates in the cold heat exchanger (64).

As shown in FIG. 2, the refrigerant compressed by the second compressor (22) is cooled by the intercooler (17) and then sucked into the first compressor (21). The refrigerant compressed by the first compressor (21) dissipates heat in the outdoor heat exchanger (13), flows through the receiver (15), and is cooled by the cooling heat exchanger (16). The refrigerant cooled by the cooling heat exchanger (16) is depressurized by the cooling expansion valve (63) and then evaporated by the cooling heat exchanger (64). As a result, the air inside the refrigerator is cooled. The refrigerant evaporated in the cooling heat exchanger (16) is sucked into the second compressor (22) and compressed again.

<Cooling operation>
In the cooling operation shown in FIG. 3, the first three-way valve (TV1) is in the second state and the second three-way valve (TV2) is in the first state. The outdoor expansion valve (14) is opened at a predetermined opening, the cold expansion valve (63) is fully closed, the opening of the indoor expansion valve (53) is adjusted by superheat control, and the pressure reducing valve (40) is operated. The opening degree is adjusted as appropriate. The outdoor fan (12), the cooling fan (17a), and the indoor fan (52) are operated, and the cooling fan (62) is stopped. The first compressor (21) and the third compressor (23) are operated, and the second compressor (22) is stopped. In the cooling operation, a refrigeration cycle is performed in which the refrigerant compressed by the compression element (C) dissipates heat in the outdoor heat exchanger (13) and evaporates in the indoor heat exchanger (54).

As shown in FIG. 3, the refrigerant compressed by the third compressor (23) is cooled by the intercooler (17) and then sucked into the first compressor (21). The refrigerant compressed by the first compressor (21) dissipates heat in the outdoor heat exchanger (13), flows through the receiver (15), and is cooled by the cooling heat exchanger (16). The refrigerant cooled by the cooling heat exchanger (16) is decompressed by the indoor expansion valve (53) and then evaporated by the indoor heat exchanger (54). As a result, the indoor air is cooled. The refrigerant evaporated in the indoor heat exchanger (54) is sucked into the third compressor (23) and compressed again.

<Cooling / cooling operation>
In the cooling / cooling operation shown in FIG. 4, the first three-way valve (TV1) is in the second state and the second three-way valve (TV2) is in the first state. The outdoor expansion valve (14) is opened at a predetermined opening degree, the opening degrees of the cold expansion valve (63) and the indoor expansion valve (53) are adjusted by superheat control, and the opening degree of the pressure reducing valve (40) is appropriately adjusted. Be adjusted. The outdoor fan (12), cooling fan (17a), cooling fan (62), and indoor fan (52) are operated. The first compressor (21), the second compressor (22), and the third compressor (23) are operated. In the cooling / cooling operation, the refrigerant compressed by the compression element (C) dissipates heat in the outdoor heat exchanger (13) and evaporates in the cooling heat exchanger (64) and indoor heat exchanger (54). The cycle takes place.

As shown in FIG. 4, the refrigerants compressed by the second compressor (22) and the third compressor (23) are cooled by the intercooler (17) and then transferred to the first compressor (21). Inhaled. The refrigerant compressed by the first compressor (21) dissipates heat in the outdoor heat exchanger (13), flows through the receiver (15), and is cooled by the cooling heat exchanger (16). The refrigerant cooled by the cooling heat exchanger (16) is divided into the cooling unit (60) and the indoor unit (50). The refrigerant decompressed by the cold expansion valve (63) evaporates in the cold heat exchanger (64). The refrigerant evaporated in the cold heat exchanger (64) is sucked into the second compressor (22) and compressed again. The refrigerant decompressed by the indoor expansion valve (53) evaporates by the indoor heat exchanger (54). The refrigerant evaporated in the indoor heat exchanger (54) is sucked into the third compressor (23) and compressed again.

<Heating operation>
In the heating operation shown in FIG. 5, the first three-way valve (TV1) is in the first state and the second three-way valve (TV2) is in the second state. The indoor expansion valve (53) is opened at a predetermined opening, the cold expansion valve (63) is fully closed, the opening of the outdoor expansion valve (14) is adjusted by superheat control, and the pressure reducing valve (40) The opening degree is adjusted as appropriate. The outdoor fan (12) and the indoor fan (52) are operated, and the cooling fan (17a) and the cooling fan (62) are stopped. The first compressor (21) and the third compressor (23) are operated, and the second compressor (22) is stopped. In the heating operation, a refrigeration cycle is performed in which the refrigerant compressed by the compression element (C) dissipates heat in the indoor heat exchanger (54) and evaporates in the outdoor heat exchanger (13).

As shown in FIG. 5, the refrigerant compressed by the third compressor (23) flows through the intercooler (17) and then is sucked into the first compressor (21). The refrigerant compressed by the first compressor (21) dissipates heat by the indoor heat exchanger (54). As a result, the indoor air is heated. The refrigerant dissipated by the indoor heat exchanger (54) flows through the receiver (15) and is cooled by the cooling heat exchanger (16). The refrigerant cooled by the cooling heat exchanger (16) is decompressed by the outdoor expansion valve (14) and then evaporated by the outdoor heat exchanger (13). The refrigerant evaporated in the outdoor heat exchanger (13) is sucked into the third compressor (23) and compressed again.

<Heating / cooling operation>
In the heating / cooling operation shown in FIG. 6, the first three-way valve (TV1) is installed in the first state, and the second three-way valve (TV2) is installed in the second state. The indoor expansion valve (53) is opened at a predetermined opening, the opening of the cold expansion valve (63) and the outdoor expansion valve (14) is adjusted by superheat control, and the opening of the pressure reducing valve (40) is appropriately adjusted. Will be done. The outdoor fan (12), the cooling fan (62), and the indoor fan (52) are operated, and the cooling fan (17a) is stopped. The first compressor (21), the second compressor (22), and the third compressor (23) are operated. In the heating / cooling operation, the refrigerant compressed by the compression element (C) dissipates heat in the indoor heat exchanger (54) and evaporates in the cooling heat exchanger (64) and the outdoor heat exchanger (13). A cycle (third refrigeration cycle) is performed.

As shown in FIG. 6, the refrigerant compressed by the second compressor (22) and the third compressor (23) flows through the intercooler (17) and then is sucked into the first compressor (21). Will be done. The refrigerant compressed by the first compressor (21) dissipates heat by the indoor heat exchanger (54). As a result, the indoor air is heated. The refrigerant dissipated by the indoor heat exchanger (54) flows through the receiver (15) and is cooled by the cooling heat exchanger (16). A part of the refrigerant cooled by the cooling heat exchanger (16) is decompressed by the outdoor expansion valve (14) and then evaporated by the outdoor heat exchanger (13). The refrigerant evaporated in the outdoor heat exchanger (13) is sucked into the third compressor (23) and compressed again.

The rest of the refrigerant cooled by the cooling heat exchanger (16) is decompressed by the cooling expansion valve (63) and then evaporated by the cooling heat exchanger (64). As a result, the air inside the refrigerator is cooled. The refrigerant evaporated in the cold heat exchanger (64) is sucked into the second compressor (22) and compressed again.

<Heating / cooling heat recovery operation>
In the heating / cooling heat recovery operation shown in FIG. 7, the first three-way valve (TV1) is in the first state and the second three-way valve (TV2) is in the second state. The indoor expansion valve (53) is opened at a predetermined opening, the outdoor expansion valve (14) is fully closed, the opening of the cold expansion valve (63) is adjusted by superheat control, and the pressure reducing valve (40) The opening degree is adjusted as appropriate. The indoor fan (52) and the cold fan (62) are operated, and the outdoor fan (12) is stopped. The cooling fan (17a) is operated in principle at the start of the heating / cooling heat recovery operation. The first compressor (21) and the second compressor (22) are operated, and the third compressor (23) is stopped. In the heating / cooling heat recovery operation, the refrigerant compressed by the compression element (C) dissipates heat in the indoor heat exchanger (54) and evaporates in the cold heat exchanger (64), and then evaporates in the outdoor heat exchanger (13). ) Is substantially stopped (first refrigeration cycle). In principle, the cooling fan (17a) may be stopped at the start of the heating / cooling heat recovery operation.

As shown in FIG. 7, the refrigerant compressed by the second compressor (22) is cooled by the intercooler (17) and then sucked into the first compressor (21). The refrigerant compressed by the first compressor (21) dissipates heat by the indoor heat exchanger (54). As a result, the indoor air is heated. The refrigerant dissipated by the indoor heat exchanger (54) flows through the receiver (15) and is cooled by the cooling heat exchanger (16). The refrigerant cooled by the cooling heat exchanger (16) is depressurized by the cooling expansion valve (63) and then evaporated by the cooling heat exchanger (64). The refrigerant evaporated in the cold heat exchanger (64) is sucked into the second compressor (22) and compressed again.

<Heating / cooling residual heat operation>
As shown in FIG. 8, in the heating / cooling residual heat operation, the first three-way valve (TV1) is in the first state and the second three-way valve (TV2) is in the first state. The indoor expansion valve (53) and the outdoor expansion valve (14) are opened at a predetermined opening degree, the opening degree of the cold expansion valve (63) is adjusted by superheat control, and the opening degree of the pressure reducing valve (40) is appropriately adjusted. Will be done. The outdoor fan (12), the cooling fan (62), and the indoor fan (52) are operated, and the cooling fan (17a) is stopped. The first compressor (21) and the second compressor (22) are operated, and the third compressor (23) is stopped. In the heating / cooling residual heat operation, the refrigerant compressed by the compression element (C) dissipates heat in the indoor heat exchanger (54) and the outdoor heat exchanger (13), and evaporates in the cold heat exchanger (64). A refrigeration cycle (second refrigeration cycle) is performed.

As shown in FIG. 8, the refrigerant compressed by the second compressor (22) flows through the intercooler (17) and then is sucked into the first compressor (21). A part of the refrigerant compressed by the first compressor (21) is dissipated by the outdoor heat exchanger (13). The rest of the refrigerant compressed by the first compressor (21) is dissipated by the indoor heat exchanger (54). As a result, the indoor air is heated. The refrigerant radiated by the outdoor heat exchanger (13) and the refrigerant radiated by the indoor heat exchanger (54) merge, flow through the receiver (15), and are cooled by the cooling heat exchanger (16). The refrigerant cooled by the cooling heat exchanger (16) is depressurized by the cooling expansion valve (63) and then evaporated by the cooling heat exchanger (64). As a result, the air inside the refrigerator is cooled. The refrigerant evaporated in the cold heat exchanger (64) is sucked into the second compressor (22) and compressed again.

<Defrost operation>
In the defrost operation, the same operation as the cooling operation shown in FIG. 3 is performed. In the defrost operation, the refrigerant compressed by the second compressor (22) and the first compressor (21) dissipates heat by the outdoor heat exchanger (13). As a result, the frost on the surface of the outdoor heat exchanger (13) is heated from the inside. The refrigerant used for defrosting the outdoor heat exchanger (13) evaporates in the indoor heat exchanger (54), is sucked into the second compressor (22), and is compressed again.

-Issues of flow path switching mechanism-
The first operation includes a heating / cooling operation, a heating / heat recovery operation, and a heating / cooling residual heat operation. Here, the first operation is an operation in which the indoor unit (50) heats the room and the cooling unit (60) cools the inside of the refrigerator. In the first operation of the refrigerating apparatus of the conventional example, the heating / cooling operation, the heating / heat recovery operation, and the heating / cooling residual heat operation are switched according to the heating capacity (heating capacity) of the indoor heat exchanger. Specifically, when the heating capacity is insufficient for the heating load, the heating / cooling operation is executed, and when the heating load and the heating capacity are balanced, the heating / heat recovery operation is executed to reduce the heating load. On the other hand, when the heating capacity was surplus, the heating / cooling residual heat operation was executed. In such control, these three operations are switched at a relatively high frequency depending on the excess or deficiency of the heating capacity. Therefore, there is a problem that the switching frequency of the flow path switching mechanism (flow path switching mechanism (30)) increases.

If the switching frequency of the flow path switching mechanism (30) increases, 1) the life of the flow path switching mechanism (30) is shortened, and 2) noise is likely to be generated when the flow path switching mechanism (30) is switched. 3) There arises a problem that the compression element (C) needs to be temporarily stopped when the flow path switching mechanism (30) is switched.

In consideration of such a problem, the refrigerating apparatus (1) of the present embodiment performs the following control so as to reduce the switching frequency of the flow path switching mechanism (30).

-Switching control of each operation and control of cooling fan-
The control of each operation of the heating / cooling heat recovery operation, the heating / cooling residual heat operation, and the heating / cooling operation, and the control of the air volume of the cooling fan (17a) will be described with reference to FIG. Here, first, the description will be made based on the state in which the heating / cooling heat recovery operation is performed.

In the heating / cooling heat recovery operation, the first refrigeration cycle is performed in which the indoor heat exchanger (54) is used as a radiator, the cold heat exchanger (64) is used as an evaporator, and the outdoor heat exchanger (13) is stopped. Be told. The heating / cooling heat recovery operation is performed under the condition that the heating capacity of the indoor heat exchanger (54) and the heating load are balanced.

<Control of cooling fan for heating / cooling heat recovery operation>
In the heating / cooling heat recovery operation, when the balance between the heating capacity of the indoor heat exchanger (54) and the heating load is lost and the first condition indicating that the heating capacity is excessive is satisfied, the controller (100) determines. Increase the air volume of the cooling fan (17a). To increase the air volume of the cooling fan (17a) referred to here is to operate the cooling fan (17a) from the state where the cooling fan (17a) is stopped, and to increase the air volume of the cooling fan (17a) in the operating state. Includes an increase in air volume.

The first condition includes the conditions a1) to a5). When any of the conditions a1) to a5) is satisfied, it is determined that the heating capacity is excessive. As a result, the air volume of the cooling fan (17a) increases. The air volume (so-called fan tap) of the cooling fan (17a) of this example is changed in a plurality of stages. The conditions a1) to a5) will be described in detail.

a1) High pressure (HP) is higher than the specified value. This predetermined value is a value obtained by adding a predetermined value α to the target high pressure.

a2) The opening degree of the indoor expansion valve (53) of all the indoor units (50) is equal to or less than the predetermined value. This predetermined value is, for example, an opening corresponding to a pulse of 50% of the fully opened opening of the indoor expansion valve (53).

a3) Set temperature-room temperature (Ti) <predetermined value. This predetermined value is, for example, 0.5 ° C. The set temperature corresponds to the target temperature of the target space (indoor space).

a4) Th2-room temperature (Ti) ≥ predetermined value. Th2 is the refrigerant temperature on the outlet side of the indoor heat exchanger (54) in the state of the radiator. This predetermined value is, for example, 10 ° C.

a5) Mean value of discharge temperature (Td) and Th2 ≥ predetermined value. The average value of the discharge temperature (Td) and the refrigerant temperature (Th2) indicates the average refrigerant temperature of the indoor heat exchanger (54) in the state of the radiator. This predetermined value is, for example, 45 ° C., or a predetermined temperature several ° C. higher than 45 ° C.

When any of the above conditions a1) to a5) is satisfied, it is determined that the heating capacity is excessive, and the controller (100) increases the air volume of the cooling fan (17a) from the air volume before the first condition is satisfied. Let me. As a result, in the intercooler (17), the amount of heat dissipated by the refrigerant to the outdoor air increases. As a result, it is possible to prevent the heating capacity from becoming excessive while continuing the heating / cooling heat recovery operation. Therefore, it is possible to reduce the frequency of switching from the heating / cooling heat recovery operation to the heating / cooling residual heat operation.

In the heating / cooling heat recovery operation, when the second condition indicating that the heating capacity is insufficient during the operation of the cooling fan (17a) is satisfied, the controller (100) sets the air volume of the cooling fan (17a) to the second. Reduce the air volume before the conditions are met. The second condition includes the conditions b1) to b5). If any of the conditions b1) to b5) is satisfied, it is determined that the heating capacity is insufficient. As a result, the air volume of the cooling fan (17a) is reduced. The conditions of b1) to b5) will be described in detail.

b1) High pressure (HP) is lower than the specified value. This predetermined value is a value obtained by subtracting the above-mentioned predetermined value α from the target high pressure.

b2) The opening of the indoor expansion valve (53) of the indoor unit (50) is fully open.

b3) Set temperature-room temperature (Ti)> predetermined value. This predetermined value is, for example, 0.5 ° C.

b4) Th2-Room temperature (Ti) <predetermined value. Th2 is the refrigerant temperature on the outlet side of the indoor heat exchanger (54) in the state of the radiator. This predetermined value is, for example, 5 ° C.

b5) The average value of discharge temperature (Td) and Th2 <predetermined value. This predetermined value is, for example, 45 ° C., or a predetermined temperature several ° C. higher than 45 ° C.

If any of the above b1) to b5) is satisfied, it is determined that the heating capacity is insufficient, and the air volume of the cooling fan (17a) decreases. As a result, in the intercooler (17), the amount of heat dissipated by the refrigerant to the outdoor air is reduced. As a result, it is possible to prevent the heating capacity from becoming insufficient while continuing the heating / cooling heat recovery operation. Therefore, it is possible to reduce the frequency of switching from the heating / cooling heat recovery operation to the heating / cooling operation.

In the heating / cooling heat recovery operation of the present embodiment, the air volume of the cooling fan (17a) is adjusted in the range from the minimum air volume to the maximum air volume according to the excess or deficiency of the heating capacity. Here, the minimum air volume includes zero.

<Switching control from heating / cooling heat recovery operation to heating / cooling residual heat operation>
In the heating / cooling heat recovery operation, if both the condition indicating that the heating capacity is excessive (third condition) and the condition that the air volume of the cooling fan (17a) is maximum are satisfied, the heating / cooling heat is satisfied. Switch from recovery operation to heating / cooling residual heat operation. In other words, the controller (100) switches from the first refrigeration cycle to the second refrigeration cycle when at least two of these conditions are met.

The third condition includes the conditions c1) to c3). When any of the conditions c1) to c3) is satisfied, it is determined that the heating capacity is excessive. The conditions of c1) to c3) will be described in detail.

c1) High pressure (HP) is higher than the specified value. This predetermined value is a value obtained by adding a predetermined value β to the target high pressure. Here, β is larger than the above α.

c2) The opening degree of all indoor expansion valves is less than or equal to the specified value. This predetermined value is, for example, an opening corresponding to a pulse of 40% of the fully opened opening of the indoor expansion valve (53).

c3) Th2-room temperature (Ti) ≥ predetermined value. This predetermined value is, for example, 15 ° C.

When any of the above conditions c1) to c3) is satisfied and c4) the air volume of the cooling fan (17a) is maximum, the controller (100) switches from the first refrigeration cycle to the second refrigeration cycle. , Control the flow path switching mechanism (30) and other valves. As a result, the heating / cooling residual heat operation is executed.

In addition, in the heating / cooling heat recovery operation, c5) even when all the indoor units (50) are temporarily stopped (so-called thermo-off state), the operation is switched to the heating / cooling residual heat operation. Here, the thermo-off state of the indoor unit (50) means that the indoor unit (50) is substantially stopped when the indoor temperature (Ti) reaches the set temperature.

<Control of cooling fan for heating / cooling residual heat operation>
When any of the above conditions c1) to c3) is satisfied, and c4) the air volume of the cooling fan (17a) is maximum, or c5) all indoor units (50) are temporarily stopped (so-called thermo-off). If the state), the controller (100) switches from the first refrigeration cycle to the second refrigeration cycle. In the second refrigeration cycle, that is, the heating / cooling residual heat operation, the cooling fan (17a) is stopped as described above. However, in the heating / cooling residual heat operation, the air volume of the cooling fan (17a) may be controlled in the same manner as in the heating / cooling heat recovery operation.

Specifically, when any of the first conditions (a1) to a5) indicating that the heating capacity is excessive is satisfied, the controller (100) sets the air volume of the cooling fan (17a) to the first. Increase the air volume before the conditions are met. To increase the air volume of the cooling fan (17a) referred to here is to operate the cooling fan (17a) from the state where the cooling fan (17a) is stopped, and to increase the air volume of the cooling fan (17a) in the operating state. Includes an increase in air volume.

When any of the second conditions (b1) to b5) indicating that the heating capacity is insufficient during the operation of the cooling fan (17a) is satisfied, the controller (100) determines the air volume of the cooling fan (17a). , The air volume is reduced compared to before the second condition is satisfied.

In this way, even in the heating / cooling residual heat operation, the air volume of the cooling fan (17a) is adjusted according to the excess or deficiency of the heating capacity. Therefore, the frequency of switching from the heating / cooling residual heat operation to the heating / heat recovery operation can be reduced.

In the heating / cooling residual heat operation of the present embodiment, the air volume of the cooling fan (17a) is adjusted in the range from the minimum air volume to the maximum air volume according to the excess or deficiency of the heating capacity. Here, the minimum air volume includes zero.

<Switching control from heating / cooling heat residual heat operation to heating / cooling heat recovery operation>
In the heating / cooling residual heat operation, if both the condition indicating that the heating capacity is insufficient (fourth condition) and the condition that the air volume of the cooling fan (17a) is the minimum are satisfied, the heating / cooling residual heat operation is started. Switch to heating / cooling heat recovery operation. In other words, the controller (100) switches from the second refrigeration cycle to the first refrigeration cycle when at least two of these conditions are met.

The fourth condition includes the conditions d1) to d3). If any of the conditions d1) to d3) is satisfied, it is determined that the heating capacity is insufficient. The conditions of d1) to d3) will be described in detail.

d1) High pressure (HP) is lower than the specified value. This predetermined value is a value obtained by subtracting the predetermined value α from the target high pressure.

d2) All indoor expansion valves are fully open.

d3) Set temperature-room temperature (Ti)> predetermined value. This predetermined value is, for example, 3 ° C.

When any of the above conditions d1) to d3) is satisfied and d4) the air volume of the cooling fan (17a) is the minimum, the controller (100) switches from the second refrigeration cycle to the first refrigeration cycle. , Control the flow path switching mechanism (30) and other valves. As a result, the heating / cooling heat recovery operation is executed.

<Switching control from heating / cooling heat recovery operation to heating / cooling operation>
In the heating / cooling heat recovery operation, when both the condition indicating that the heating capacity is insufficient (fifth condition) and the condition that the air volume of the cooling fan (17a) is the minimum are satisfied, the heating / cooling heat recovery is performed. Switch from operation to heating / cooling operation. In other words, the controller (100) switches from the first refrigeration cycle to the third refrigeration cycle when at least two of these conditions are met.

The fifth condition includes the conditions of e1) to e5). If any of the conditions e1) to e5) is satisfied, it is determined that the heating capacity is insufficient. The conditions of e1) to e5) will be described in detail.

e1) High pressure (HP) is lower than the specified value. This predetermined value is a value obtained by subtracting the above-mentioned predetermined value α from the target high pressure.

e2) The opening of the indoor expansion valve (53) of the indoor unit (50) is fully open.

e3) Set temperature-room temperature (Ti)> predetermined value. This predetermined value is, for example, 0.5 ° C.

e4) Th2-Room temperature (Ti) <predetermined value. Th2 is the refrigerant temperature on the outlet side of the indoor heat exchanger (54) in the state of the radiator. This predetermined value is, for example, 5 ° C.

e5) The average value of discharge temperature (Td) and Th2 <predetermined value. This predetermined value is, for example, 45 ° C., or a predetermined temperature several ° C. higher than 45 ° C.

When any of the above conditions e1) to e5) is satisfied, and e6) the air volume of the cooling fan (17a) is the minimum, the controller (100) switches from the first refrigeration cycle to the third refrigeration cycle. , Control the flow path switching mechanism (30) and other valves. As a result, the heating / cooling operation is executed.

<Control of cooling fan for heating / cooling operation>
When any of the above conditions e1) to e5) is satisfied and e6) the air volume of the cooling fan (17a) is the minimum, the controller (100) switches from the first refrigeration cycle to the third refrigeration cycle. In the third refrigeration cycle, that is, the heating / cooling operation, the cooling fan (17a) is stopped as described above. However, in the heating / cooling operation, the air volume of the cooling fan (17a) may be controlled in the same manner as in the heating / cooling heat recovery operation.

Specifically, when any of the first conditions (a1) to a5) indicating that the heating capacity is excessive is satisfied, the controller (100) sets the air volume of the cooling fan (17a) to the first. Increase the air volume before the conditions are met. To increase the air volume of the cooling fan (17a) referred to here is to operate the cooling fan (17a) from the state where the cooling fan (17a) is stopped, and to increase the air volume of the cooling fan (17a) in the operating state. Includes an increase in air volume.

When any of the second conditions (b1) to b5) indicating that the heating capacity is insufficient during the operation of the cooling fan (17a) is satisfied, the controller (100) determines the air volume of the cooling fan (17a). , The air volume is reduced compared to before the second condition is satisfied. In this way, even in the heating / cooling operation, the air volume of the cooling fan (17a) is adjusted according to the excess or deficiency of the heating capacity. Therefore, the frequency of switching from the heating / cooling operation to the heating / cooling heat recovery operation can be reduced.

In the heating / cooling operation of the present embodiment, the air volume of the cooling fan (17a) is adjusted in the range from the minimum air volume to the maximum air volume according to the excess or deficiency of the heating capacity. Here, the minimum air volume includes zero.

<Switching control from heating / cooling operation to heating / cooling heat recovery operation>
In the heating / cooling operation, if both the condition indicating that the heating capacity is excessive (sixth condition) and the condition that the air volume of the cooling fan (17a) is maximum are satisfied, the heating / cooling operation is started. / Switch to cold heat recovery operation. In other words, the controller (100) switches from the third refrigeration cycle to the first refrigeration cycle when at least two of these conditions are met.

The sixth condition includes the conditions of f1) to f5). When any of the conditions f1) to f5) is satisfied, it is determined that the heating capacity is excessive. The conditions of f1) to f5) will be described in detail.

f1) High pressure (HP) is above the specified value. This predetermined value is a value obtained by subtracting the predetermined value α from the target high pressure.

f2) The opening of the indoor expansion valve is not fully open.

f3) Set temperature-room temperature (Ti) ≤ predetermined value. This predetermined value is, for example, 0.5 ° C.

f4) Th2-room temperature (Ti) ≥ predetermined value. This predetermined value is, for example, 5 ° C.

f5) The average value of discharge temperature (Td) and Th2 <predetermined value. This predetermined value is, for example, 45 ° C., or a predetermined temperature several ° C. higher than 45 ° C.

When any of the above conditions f1) to f5) is satisfied and f6) the air volume of the cooling fan (17a) is maximum, the controller (100) switches from the third refrigeration cycle to the first refrigeration cycle. , Control the flow path switching mechanism (30) and other valves. As a result, the heating / cooling heat recovery operation is executed.

In addition, in the heating / cooling operation, f7) even when all the indoor units (50) are temporarily stopped (so-called thermo-off state), the operation is switched to the heating / cooling recovery operation.

-Effect of embodiment-
In the embodiment, a compression element (C) including a first compression unit (21) and a second compression unit (22, 23) connected in series, a heat source heat exchanger (13), and a first utilization heat exchanger. It has (54), a second utilization heat exchanger (64), and a flow path switching mechanism (30), and at least the first refrigeration cycle and the second refrigeration cycle can be performed by switching the flow path switching mechanism (30). A refrigeration apparatus including a refrigerant circuit (6) configured to perform the operation and a controller (100), wherein the refrigerant circuit (6) is described in the first refrigeration cycle and the second refrigeration cycle. An intermediate flow path (41) for introducing a refrigerant into an intermediate pressure section (21a) between the first compression section (21) and the second compression section (22, 23), and a refrigerant flowing through the intermediate flow path (41). It has an intermediate cooler (17) that cools the heat medium, and in the first refrigeration cycle, the heat source heat exchanger (13) is stopped and the first utilization heat exchanger (54) is used as a radiator. , The refrigeration cycle using the second utilization heat exchanger (64) as an evaporator, and the second refrigeration cycle uses the heat source heat exchanger (13) and the first utilization heat exchanger (54) as radiators. In the refrigeration cycle in which the second utilization heat exchanger (64) is used as an evaporator, the controller (100) has a heating capacity of the first utilization heat exchanger (54) in the first refrigeration cycle. When the condition indicating that is excessive is satisfied, the cooling capacity of the intermediate cooler (17) is increased.

In this form, it is possible to reduce the frequency of switching from the heating / cooling heat recovery operation to the heating / cooling residual heat operation under the condition that the heating capacity is excessive.

The cooling fan (17a) and the intercooler (17) have both a function of cooling the intermediate pressure refrigerant and a function of adjusting the heating capacity. Therefore, the number of parts of the refrigerating apparatus (1) can be reduced. By cooling the intermediate pressure refrigerant, the temperature of the refrigerant discharged from the compression element (C) can be reduced.

In the embodiment, the controller (100) (controller) indicates that the heating capacity (heating capacity) of the first utilization heat exchanger (54) (indoor heat exchanger) is excessive in the first refrigeration cycle. When both the condition shown and the condition that the cooling capacity of the intercooler (17) is equal to or higher than a predetermined value are satisfied, the flow path switching mechanism (30) is controlled so as to perform the second refrigeration cycle.

In this form, in the heating / cooling heat recovery operation, if the heating capacity of the indoor heat exchanger (54) is excessive and the air volume of the cooling fan (17a) is a predetermined value (maximum), the heating / cooling installation is performed. Switch from heat recovery operation to heating / cooling residual heat operation. Therefore, it is possible to avoid switching to the heating / cooling residual heat operation until the air volume of the cooling fan (17a) reaches the maximum. Therefore, the frequency of switching from the heating / cooling heat recovery operation to the heating / cooling residual heat operation can be reduced.

In the embodiment, the controller (100) (controller) is the first utilization heat exchanger (54) (54) while the intercooler (17) is cooling the refrigerant during the second refrigeration cycle. When the condition indicating that the heating capacity (heating capacity) of the indoor heat exchanger) is insufficient is satisfied, the cooling capacity of the intercooler (17) is reduced.

In this embodiment, in the heating / cooling residual heat operation in which the second refrigeration cycle is performed, the air volume of the cooling fan (17a) is reduced when the condition indicating that the heating capacity is insufficient is satisfied. Therefore, it is possible to reduce the frequency of switching from the heating / cooling residual heat operation to the heating / cooling heat recovery operation under the condition that the heating capacity is insufficient.

In the embodiment, the controller (100) (controller) has insufficient heating capacity (heating capacity) of the first utilization heat exchanger (54) (indoor heat exchanger) in the second refrigeration cycle. When both the condition shown and the condition that the cooling capacity of the intercooler (17) is equal to or less than a predetermined value are satisfied, the flow path switching mechanism (30) is controlled so as to perform the first refrigeration cycle.

In this mode, in the heating / cooling residual heat operation, if the heating capacity of the indoor heat exchanger (54) is insufficient and the air volume of the cooling fan (17a) is a predetermined value (minimum), the heating / cooling residual heat operation is performed. Switch to heating / cooling heat recovery operation. Therefore, it is possible to avoid switching to the heating / cooling heat recovery operation until the air volume of the cooling fan (17a) reaches the minimum. Therefore, it is possible to reduce the frequency of switching from the heating / cooling residual heat operation to the heating / cooling heat recovery operation.

In the embodiment, the refrigerant circuit (6) is configured to perform the third refrigeration cycle by switching the flow path switching mechanism (30), and the third refrigeration cycle is the first utilization heat exchanger (the first utilization heat exchanger). 54) (Indoor heat exchanger) is used as a radiator, and the heat source heat exchanger (13) (outdoor heat exchanger) and the second utilization heat exchanger (64) (cold heat exchanger) are used as evaporators. In the refrigeration cycle, the intermediate flow path (41) is configured to introduce a refrigerant into the intermediate pressure portion (21a) in the third refrigeration cycle, and the controller (100) (controller) is the same. When the condition indicating that the heating capacity (heating capacity) of the first utilization heat exchanger (54) is insufficient is satisfied while the intermediate cooler (17) is cooling the refrigerant during the first refrigeration cycle. , The cooling capacity of the intermediate cooler (17) is reduced.

In this embodiment, in the heating / cooling heat recovery operation in which the first refrigeration cycle is performed, the air volume of the cooling fan (17a) is reduced when the condition indicating that the heating capacity is insufficient is satisfied. Therefore, it is possible to reduce the frequency of switching from the heating / cooling heat recovery operation to the heating / cooling operation under the condition that the heating capacity is insufficient.

In the embodiment, the controller (100) is a condition indicating that the heating capacity (heating capacity) of the first utilization heat exchanger (54) (indoor heat exchanger) is insufficient in the first refrigeration cycle. When both the conditions that the cooling capacity of the intercooler (17) is equal to or less than a predetermined value are satisfied, the flow path switching mechanism (30) is controlled so as to perform the third refrigeration cycle.

In this form, in the heating / cooling heat recovery operation, if the heating capacity of the indoor heat exchanger (54) is insufficient and the air volume of the cooling fan (17a) is a predetermined value (minimum), the heating / cooling heat Switch from recovery operation to heating / cooling operation. Therefore, it is possible to avoid switching to the heating / cooling operation until the air volume of the cooling fan (17a) reaches the minimum. Therefore, it is possible to reduce the frequency of switching from the heating / cooling heat recovery operation to the heating / cooling operation.

In the embodiment, the controller (100) (controller) has an excessive heating capacity (heating capacity) of the first utilization heat exchanger (54) (indoor heat exchanger) in the third refrigeration cycle. When the condition indicating the above is satisfied, the cooling capacity of the intercooler (17) is increased.

In this embodiment, in the heating / cooling operation in which the third refrigeration cycle is performed, the air volume of the cooling fan (17a) is increased when the condition indicating that the heating capacity is excessive is satisfied. Therefore, it is possible to reduce the frequency of switching from the heating / cooling operation to the heating / cooling heat recovery operation under the condition that the heating capacity becomes excessive.

In the embodiment, the controller (100) (controller) has an excessive heating capacity (heating capacity) of the first utilization heat exchanger (54) (indoor heat exchanger) in the third refrigeration cycle. When both the condition indicating the above and the condition that the cooling capacity of the intercooler (17) is equal to or higher than a predetermined value are satisfied, the flow path switching mechanism (30) is controlled so as to perform the first refrigeration cycle.

In this form, in the heating / cooling operation, if the heating capacity of the indoor heat exchanger (54) is excessive and the air volume of the cooling fan (17a) is a predetermined value (maximum), the heating / cooling operation is performed. Switch to heating / cooling heat recovery operation. Therefore, it is possible to avoid switching to the heating / cooling heat recovery operation until the air volume of the cooling fan (17a) reaches the maximum. Therefore, the frequency of switching from the heating / cooling operation to the heating / cooling heat recovery operation can be reduced.

By reducing the switching frequency of each operation in this way, the mechanical life of the flow path switching mechanism (30) can be extended. The noise associated with the switching of the flow path switching mechanism (30) can be reduced. The frequency with which each compressor (21, 22, 23) is stopped due to the switching of the flow path switching mechanism (30) can also be reduced.

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In the above embodiment, the configuration may be as follows.

The intercooler (17) is an air-cooled type that cools the refrigerant in the intermediate flow path (41) with the air conveyed by the intermediate fan (17a). However, the intercooler (17) may be of a method of cooling the refrigerant of the intermediate flow path (41) with a heat medium other than air. Examples of the heat medium include refrigerant, brine, water and the like. The controller (100) controls the temperature and flow rate of these heat media so as to adjust the cooling capacity of the intercooler (17).

The compression element (C) includes a motor, a drive shaft connected to the motor, a first compression mechanism (first compression unit) connected to the drive shaft, and a second compression mechanism (second compression unit). ) And may be a multi-stage compressor. The intermediate flow path introduces the refrigerant into the intermediate pressure portion between the first compression mechanism and the second compression mechanism.

The first utilization heat exchanger (54) does not necessarily have to be an indoor heat exchanger, and does not necessarily have to be an air heat exchanger that exchanges heat between air and a refrigerant. The first utilization heat exchanger (54) may be, for example, a heat heat exchanger that heats water or brine with a refrigerant.

The second utilization heat exchanger (64) does not necessarily have to be a cold heat exchanger, and does not necessarily have to be an air heat exchanger that exchanges heat between air and a refrigerant. The second utilization heat exchanger (64) may be, for example, a cooling heat exchanger that cools water or brine with a refrigerant.

In the conditions c4) and c6) shown in FIG. 9, it is a condition that the air volume of the cooling fan (17a) is maximum. However, these conditions may be that the air volume of the cooling fan (17a) is equal to or greater than a predetermined value smaller than the maximum value. In the conditions d4) and e6) shown in FIG. 9, it is a condition that the air volume of the cooling fan (17a) is the minimum. However, these conditions may be that the air volume of the cooling fan (17a) is larger than the minimum value (including zero) and equal to or less than a predetermined value.

The flow path switching mechanism (30) of the embodiment includes two three-way valves (TV1, TV2). However, the flow path switching mechanism (30) may include two four-way switching valves. When switching the pilot type four-way switching valve, a large noise is generated due to the movement of the spool valve based on the high and low differential pressure. In the refrigerant circuit, this noise is particularly large in a configuration in which the refrigerant (for example, carbon dioxide) is compressed to a critical pressure or higher. On the other hand, in the present embodiment, since the switching frequency of the flow path switching mechanism (30) can be reduced as described above, the frequency of occurrence of such noise can be reduced. The flow path switching mechanism (30) may have a configuration in which a plurality of solenoid valves and flow rate control valves are combined.

Although the embodiments and modifications have been described above, it will be understood that various modifications of the forms and details are possible without departing from the purpose and scope of the claims. In addition, the above embodiments and modifications may be appropriately combined or replaced as long as they do not impair the functions of the present disclosure. The above-mentioned descriptions of "first", "second", "third" ... Are used to distinguish the words and phrases to which these descriptions are given, and the number and order of the words and phrases are also limited. It's not something to do.

As described above, the present disclosure is useful for refrigeration equipment.

1 Refrigerant device 6 Refrigerant circuit 13 Outdoor heat exchanger (heat source heat exchanger)
17 Intercooler 17a Cooling fan (intermediate fan)
21 First compressor (first compression unit)
21a Intermediate pressure section 22 Second compressor (second compression section)
23 Third compressor (third compression unit)
30 Flow path switching mechanism 41 Intermediate flow path 54 Indoor heat exchanger (1st utilization heat exchanger)
64 Cold heat exchanger (second heat exchanger)
100 controller (controller)

Claims (9)

A compression element (C) including a first compression unit (21) and a second compression unit (22, 23) connected in series, a heat source heat exchanger (13), and a first utilization heat exchanger (54). , It has a second utilization heat exchanger (64) and a flow path switching mechanism (30), and is configured to perform at least the first refrigeration cycle and the second refrigeration cycle by switching the flow path switching mechanism (30). Refrigerant circuit (6) and
A refrigerating device equipped with a controller (100).
The refrigerant circuit (6)
Intermediate flow channel that connects the first compression section before Symbol the second compression unit (21) and (22, 23) and (41),
It has an intercooler (17) that cools the refrigerant flowing through the intermediate flow path (41) with a heat medium.
In the first refrigeration cycle, the heat source heat exchanger (13) is stopped, the first utilization heat exchanger (54) is used as a radiator, and the second utilization heat exchanger (64) is used as an evaporator. It's a cycle
The second refrigeration cycle is a refrigeration cycle in which the heat source heat exchanger (13) and the first utilization heat exchanger (54) are used as radiators, and the second utilization heat exchanger (64) is used as an evaporator. ,
When the condition indicating that the heating capacity of the first utilization heat exchanger (54) is excessive is satisfied in the first refrigeration cycle, the controller (100) has a cooling capacity of the intercooler (17). A freezing device characterized by increasing the number of. In claim 1,
The controller (100) defines a condition indicating that the heating capacity of the first utilization heat exchanger (54) is excessive in the first refrigeration cycle and a cooling capacity of the intercooler (17). A refrigerating apparatus characterized in that the flow path switching mechanism (30) is controlled so as to perform the second refrigerating cycle when both the condition indicating that the value is equal to or higher than the value is satisfied. In claim 1 or 2,
The controller (100) has insufficient heating capacity of the first utilization heat exchanger (54) when the intercooler (17) is cooling the refrigerant during the second refrigeration cycle. When the condition shown in the above is satisfied, the refrigerating apparatus is characterized in that the cooling capacity of the intercooler (17) is reduced. In claim 3,
The controller (100) has a condition indicating that the heating capacity of the first utilization heat exchanger (54) is insufficient in the second refrigeration cycle, and the cooling capacity of the intercooler (17) is a predetermined value. A refrigerating apparatus characterized in that the flow path switching mechanism (30) is controlled so as to perform the first refrigerating cycle when both of the conditions indicating the following are satisfied. In any one of claims 1 to 4,
The refrigerant circuit (6) is configured to perform a third refrigeration cycle by switching the flow path switching mechanism (30).
The third refrigeration cycle is a refrigeration cycle in which the first utilization heat exchanger (54) is used as a radiator and the heat source heat exchanger (13) and the second utilization heat exchanger (64) are used as evaporators. ,
Wherein the controller (100), when said intercooler (17) is performing the cooling of the refrigerant in the first refrigeration cycle, the heating capacity of the first utilization heat exchanger (54) is insufficient When the condition shown in the above is satisfied, the refrigerating apparatus is characterized in that the cooling capacity of the intercooler (17) is reduced. In claim 5,
The controller (100) has a condition indicating that the heating capacity of the first utilization heat exchanger (54) is insufficient in the first refrigeration cycle, and the cooling capacity of the intercooler (17) is a predetermined value. A refrigerating apparatus characterized in that the flow path switching mechanism (30) is controlled so as to perform the third refrigerating cycle when both of the following conditions are satisfied. In claim 5 or 6,
When the condition indicating that the heating capacity of the first utilization heat exchanger (54) is excessive is satisfied in the third refrigeration cycle, the controller (100) has a cooling capacity of the intercooler (17). A freezing device characterized by increasing the number of. In claim 7,
In the controller (100), the condition indicating that the heating capacity of the first utilization heat exchanger (54) is excessive in the third refrigeration cycle and the cooling capacity of the intercooler (17) are predetermined. A refrigerating apparatus characterized in that the flow path switching mechanism (30) is controlled so as to perform the first refrigerating cycle when both the conditions of the value or more are satisfied. In any one of claims 1 to 8,
An intermediate fan (17a) for carrying air as the heat medium for cooling the refrigerant flowing through the intermediate flow path (41) is further provided.
The controller (100) is a refrigerating device characterized in that the cooling capacity is adjusted by adjusting the air volume of the intermediate fan (17a).

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