JP2011047622A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner achieving to be made compact and a reduction in production costs of outdoor units capable of connecting three inter-unit piping. <P>SOLUTION: The air conditioner includes: a first outdoor unit 2 with a first compressor 20, a first four-way valve 24, and first outdoor heat exchangers 21, 21; the inter-unit piping 5 consisting of a high pressure gas pipe 7 connected to a refrigerant discharge branch pipe 25A branching off from a midway between the first compressor 20 and the first four-way valve 24, a low pressure gas pipe 6 connected to a refrigerant suction branch pipe 28A branching off from a refrigerant suction pipe 28 of the first compressor 20, and a liquid pipe 8 connected to the first outdoor heat exchangers 21, 21 via a first unit internal liquid pipe 29; and the plurality of outdoor units 4A-4D connected to the high pressure gas pipe 7, the low pressure gas pipe 6, and the liquid pipe 8 of the inter-unit piping 5 while including indoor heat exchangers 10A-10D. The first four-way valve 24 makes the low pressure gas pipe 6 and the first outdoor heat exchangers 21, 21 communicated at a first switching position, and it makes the first compressor 20 and the first outdoor heat exchangers 21, 21 communicated at a second switching position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention has an outdoor unit and a plurality of indoor units, and the plurality of indoor units can be simultaneously operated in a cooling operation or a heating operation, or these heating operations and a cooling operation can be performed in combination. It relates to a harmony device.

  In general, an outdoor unit and a plurality of indoor units are connected via a pipe between two units composed of a liquid pipe and a gas pipe, and the plurality of indoor units are cooled or heated. A pipe connection type (hereinafter referred to as two pipe type) air conditioner is known. Further, in recent years, an outdoor unit and a plurality of indoor units are connected via three inter-unit piping composed of a low pressure gas pipe, a high pressure gas pipe, and a liquid pipe, and the plurality of indoor units are simultaneously operated for cooling or A low-pressure gas pipe, a high-pressure gas pipe and a liquid pipe connection type (hereinafter referred to as three-pipe type) air conditioner that performs heating operation or performs a mixture of these cooling operation and heating operation has been proposed. (See Patent Document 1).

Japanese Patent No. 2804527

However, since the outdoor unit used in the three-pipe type air conditioner needs to be connected to a low-pressure gas pipe, a high-pressure gas pipe, and a liquid pipe, the two-pipe type outdoor unit has a refrigerant circuit configuration. Different. For this reason, compared with a two-pipe outdoor unit, the three-pipe outdoor unit has a complicated configuration of equipment connected to the pipe and the handling of the piping, and the apparatus configuration tends to be large. In addition, the three-pipe type outdoor unit is developed and manufactured independently of the two-pipe type outdoor unit, which requires a longer development period and a new production line. There was a problem of increasing.
Then, this invention solves the subject mentioned above and it aims at providing the air conditioning apparatus which aimed at the compactization of the outdoor unit which can connect the piping between three units, and reduction of production cost.

  In order to achieve the above object, the present invention provides a first outdoor unit having a first compressor, a first four-way valve, and a first outdoor heat exchanger, and between the first compressor and the first four-way valve. An inter-unit pipe having a branching high-pressure gas pipe, a low-pressure gas pipe connected to the refrigerant suction pipe of the first compressor, and a liquid pipe connected to the first outdoor heat exchanger, and a high pressure of the inter-unit pipe A plurality of indoor units connected to a gas pipe, a low-pressure gas pipe, and a liquid pipe and having an indoor heat exchanger, wherein the first four-way valve has a low-pressure gas pipe and the first outdoor heat at a first switching position. An exchanger is communicated, and the first compressor and the first outdoor heat exchanger are communicated at a second switching position.

  According to this configuration, the first outdoor unit connected to the three inter-unit pipes is configured using a so-called two-pipe existing outdoor unit having a compressor, a four-way valve, and an outdoor heat exchanger. Therefore, the production cost can be reduced as compared with the case of independently developing a three-pipe outdoor unit. In addition, since the first outdoor unit is configured based on a so-called two-pipe outdoor unit, the first outdoor unit is made more compact than the conventional three-pipe outdoor unit. Can be achieved.

  In this configuration, the refrigerant discharge pipe of the first compressor is connected to the first port of the first four-way valve, the first outdoor heat exchanger is connected to the second port, and the refrigerant suction pipe is connected to the third port. And the fourth port is closed, or the refrigerant suction pipe may be connected to the fourth port via a capillary tube. According to this configuration, the first compressor, the first outdoor heat exchanger, the high pressure gas pipe and the low pressure gas pipe can be connected via the first four-way valve, and the first four-way valve is connected to the first switching position. By switching to the second switching position, a plurality of indoor units can be easily cooled or heated at the same time, or these heating and cooling operations can be implemented together.

  The first outdoor unit includes a plurality of the first outdoor heat exchangers arranged in parallel, and an opening / closing valve is provided between at least one first outdoor heat exchanger and the first four-way valve. It is good also as a structure. According to this configuration, since the number of the first outdoor heat exchangers used for the air conditioning operation can be changed by controlling the operation of the on-off valve by the load balance between the cooling load and the heating load during the cooling and heating mixed operation, The operating efficiency during the air conditioning operation can be improved by appropriately changing the number of one outdoor heat exchangers.

The second outdoor unit includes a second compressor and a second outdoor heat exchanger, and is connected by two pipes of a gas pipe and a liquid pipe. The liquid pipe of the second outdoor unit is connected to the inter-unit pipe. The gas pipe of the second outdoor unit was alternatively connected to the high-pressure gas pipe or low-pressure gas pipe of the inter-unit pipe using a valve body kit having a flow path switching valve. It is good also as a structure.
According to this configuration, a so-called two-pipe type outdoor unit can be connected to the three inter-unit pipes via a valve body kit having a flow path switching valve. A part of the outdoor units connected to the apparatus can be configured at low cost by using an existing two-pipe outdoor unit, and the price of the entire air conditioner can be reduced.

The valve body kit includes a single second four-way valve as the flow path switching valve, the gas pipe is connected to a first port of the second four-way valve, and the low-pressure gas pipe is connected to a second port. The high pressure gas pipe may be connected to the third port and the fourth port may be closed, or the low pressure gas pipe may be connected to the fourth port via a capillary tube.
According to this configuration, the gas pipe of the second outdoor unit can be selectively connected to the high-pressure gas pipe or the low-pressure gas pipe of the inter-unit pipe with a simple configuration in which the second four-way valve is interposed. A two-pipe outdoor unit can be connected to a three-pipe air conditioner.

  Moreover, the said valve body kit is good also as a structure provided in the outer side of the housing of the said 2nd outdoor unit. According to this configuration, since the existing two-pipe type outdoor unit can be used as the second outdoor unit without changing the pipe configuration, the configuration of the three-pipe type air conditioner is configured. It can be simplified.

  According to the present invention, the first outdoor unit connected to the three inter-unit piping is configured using a so-called two-pipe existing outdoor unit having a compressor, a four-way valve, and an outdoor heat exchanger. Therefore, the production cost can be reduced as compared with the case where a three-pipe outdoor unit is independently developed. In addition, since the first outdoor unit is configured based on a so-called two-pipe outdoor unit, the first outdoor unit is made more compact than the conventional three-pipe outdoor unit. Can be achieved.

It is a circuit diagram which shows one Embodiment of the air conditioning apparatus which concerns on this invention, and shows the flow of the refrigerant | coolant at the time of this air conditioning apparatus being air-cooled. It is a circuit diagram which shows the flow of the refrigerant | coolant at the time of an air conditioning apparatus carrying out heating operation. It is a circuit diagram which shows the flow of the refrigerant | coolant at the time of air-conditioning apparatus carrying out cooling-heating mixed operation by cooling main. In FIG. 3, it is a circuit diagram which shows the flow of the refrigerant | coolant at the time of using a part of 1st outdoor heat exchanger as a condenser. It is a circuit diagram which shows the flow of the refrigerant | coolant at the time of an air conditioning apparatus carrying out cooling-heating mixed operation mainly by heating. In FIG. 5, it is a circuit diagram which shows the flow of the refrigerant | coolant at the time of using a part of 1st outdoor heat exchanger as an evaporator.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a circuit diagram showing an embodiment of an air conditioner according to the present invention. The air conditioner 1 includes a first outdoor unit 2 that is a three-pipe outdoor unit, a second outdoor unit 3 that is a two-pipe outdoor unit, and a plurality of (for example, four) indoor units 4A. 4B, 4C, 4D. The inter-unit pipe 5 that connects the first outdoor unit 2 and the second outdoor unit 3 to the indoor units 4A to 4D is composed of a low-pressure gas pipe 6, a high-pressure gas pipe 7, and a liquid pipe 8. The harmony device 1 enables the indoor units 4 </ b> A to 4 </ b> D to be cooled or heated at the same time, or can be implemented by mixing these cooling and heating operations.

  The indoor unit 4A includes an indoor heat exchanger 10A and an indoor expansion valve 11A. One end of the indoor heat exchanger 10A is connected to the liquid pipe 8 via a liquid branch pipe 18A provided with the indoor expansion valve 11A. Connected. A branch pipe 12A is connected to the other end of the indoor heat exchanger 10A, and this branch pipe 12A branches into a high-pressure gas branch pipe 13A and a low-pressure gas branch pipe 14A. The high-pressure gas branch pipe 13A is connected to the high-pressure gas pipe 7 via the first on-off valve 15A, and the low-pressure gas branch pipe 14A is connected to the low-pressure gas pipe 6 via the second on-off valve 16A.

  The indoor unit 4A includes a temperature sensor (not shown) for detecting the inlet / outlet temperature and room temperature of the indoor heat exchanger 10A, a pressure sensor (not shown) for detecting the refrigerant pressure in the indoor heat exchanger 10A, and the like. In addition, an indoor control device (not shown) for inputting the detection results of these sensors and controlling the indoor unit 4A is provided. Since the indoor units 4B to 4D have substantially the same configuration as the indoor unit 4A, the same portions are denoted by the same reference numerals, and description thereof is omitted.

The first outdoor unit 2 includes a variable capacity type first compressor (DC inverter compressor) 20, a first four-way valve 24, and a plurality of units (in this embodiment, connected in parallel to the first four-way valve 24). 2 units | sets of 1st outdoor heat exchangers 21 and 21, 1st expansion valve 22 and 22, and the 1st unit case (housing | casing) 23 which accommodates these are comprised. The first unit case 23 includes a low pressure gas pipe service valve 23A to which each device in the first unit case 23 and the low pressure gas pipe 6, the high pressure gas pipe 7 and the liquid pipe 8 of the inter-unit pipe 5 are connected, respectively. A high-pressure gas pipe service valve 23B and a first liquid pipe service valve 23C are provided.
In this configuration, the capacity of the first compressor 20 is configured to have at least half the capacity of all the compressors included in the air conditioner 1. According to this, for example, when the cooling and heating mixed operation is executed with a load balance of 50%: 50% between the cooling load and the heating load, only the first outdoor unit 2 including the first compressor 20 is used. Thus, each of the indoor units 4A to 4D can be cooled and heated. In addition, when the cooling load or the heating load is increased and, for example, the load balance is changed to 60%: 40% between the cooling load and the heating load, the second outdoor unit 3 takes charge of the excess cooling load. Can do. For this reason, the air conditioning operation with the load balance can be realized no matter how the load balance of the cooling load and the heating load of the indoor units 4A to 4D during the cooling / heating mixed operation changes.
The first four-way valve 24 includes four ports, and the refrigerant discharge pipe 25 of the first compressor 20 is connected to the first port α. One end of a refrigerant discharge branch pipe 25A that branches between the first compressor 20 and the first four-way valve 24 is connected to the refrigerant discharge pipe 25, and the other end of the refrigerant discharge branch pipe 25A is a high-pressure gas pipe service. The high-pressure gas pipe 7 is connected via a valve 23B. Reference numeral 45 denotes a check valve.

In addition, an in-unit gas pipe 26 is connected to the second port β of the first four-way valve 24. The in-unit gas pipe 26 is branched into two in-unit branch gas pipes 26A and 26A, and each of the first outdoor heat exchanges. Connected to one end side of the vessels 21, 21. In this configuration, an in-unit branch gas pipe 26A connected to one first outdoor heat exchanger 21 is provided with an electromagnetic open / close valve (open / close valve) 27, and a refrigerant is selected for the first outdoor heat exchangers 21 and 21. It is possible to distribute it.
In-unit branch liquid pipes 29A and 29A are connected to the other ends of the first outdoor heat exchangers 21 and 21, respectively. These in-unit branch liquid pipes 29A and 29A merge to form a first unit internal liquid pipe (liquid pipe). ) 29 and is connected to the liquid pipe 8 of the inter-unit pipe 5 via the first liquid pipe service valve 23C. Moreover, the above-described first expansion valves 22 and 22 are provided in the in-unit branch liquid pipes 29A and 29A, respectively.

A refrigerant suction pipe 28 of the first compressor 20 is connected to the third port γ of the first four-way valve 24, and the refrigerant suction pipe 28 is connected to the first compressor 20 and the first four-way valve 24. One end of the refrigerant suction branch pipe 28A branching between the two is connected, and the other end of the refrigerant suction branch pipe 28A is connected to the low pressure gas pipe 6 via the low pressure gas pipe service valve 23A.
A capillary tube 46 is connected to the fourth port δ of the first four-way valve 24, and the other end of the capillary tube 46 is connected to the refrigerant suction pipe 28. In this embodiment, when the 1st outdoor unit 2 stops, the flow of the refrigerant | coolant in the refrigerant | coolant piping (refrigerant discharge pipe 25, the refrigerant | coolant suction pipe 28) in this 1st outdoor unit 2 may stop. For this reason, in order to prevent the accumulation of the refrigerant in the refrigerant pipes, the refrigerant suction pipe 28 is connected to the fourth port δ via the capillary tube 46. The fourth port δ may be simply closed with a sealing plug or the like without connecting the refrigerant suction pipe 28 to the fourth port δ via the capillary tube 46.

In this configuration, the first outdoor unit 2 can be connected to three inter-unit piping 5 by changing the piping configuration of a so-called two-pipe outdoor unit.
Specifically, the first unit case 23 is provided with a high-pressure gas pipe service valve 23B, and the high-pressure gas pipe service valve 23B and the refrigerant discharge pipe 25 are connected by a refrigerant discharge branch pipe 25A. In the two-pipe outdoor unit, a gas pipe service valve (corresponding to the low-pressure gas pipe service valve 23A in this configuration) and a four-way valve (corresponding to the fourth port δ of the first four-way valve 24 in this configuration). ), The low pressure gas pipe service valve 23A and the refrigerant suction pipe 28 are connected by the refrigerant suction branch pipe 28A, and the fourth port δ of the first four-way valve 24 is connected via the capillary tube 46. Connected to the refrigerant suction pipe 28.
In this way, the first outdoor unit 2 that can be connected to the three inter-unit piping 5 can be easily configured by partially changing the piping configuration of the existing two-pipe outdoor unit. Compared to the case of independently developing a three-pipe outdoor unit, the development period can be shortened and the production line can be shared, and the production cost can be reduced. Further, since the first outdoor unit 2 is configured based on a so-called two-pipe outdoor unit, the first outdoor unit 2 has a simpler pipe configuration than a conventional three-pipe outdoor unit. As a result, the device itself can be made compact.

  The first outdoor unit 2 includes pressure sensors (not shown) for detecting the suction pressure and discharge pressure of the first compressor 20 and the refrigerant pressure in the first outdoor heat exchangers 21 and 21, respectively. In addition to the temperature sensors (not shown) that detect the inlet / outlet temperatures and the outside air temperatures of the first outdoor heat exchangers 21 and 21, etc., the detection results of these sensors are input to control the first outdoor unit 2. A first outdoor control device (not shown) is provided.

The second outdoor unit 3 includes a variable capacity type second compressor (DC inverter compressor) 30, a four-way valve 31, a second outdoor heat exchanger 32, a second expansion valve 33, and a first that accommodates these. A gas pipe service valve 34A to which the equipment in the second unit case 34 and the two pipes of the gas pipe 35 and the liquid pipe 36 are respectively connected. A second liquid pipe service valve 34B is provided.
The second outdoor unit 3 is an existing two-pipe type (two-way) outdoor unit that can perform a cooling operation or a heating operation by switching the four-way valve 31.
The refrigerant discharge pipe 37 of the second compressor 30 is connected to the four-way valve 31 via a check valve 38, and one end of the second outdoor heat exchanger 32 is connected to the four-way valve 31 via a unit internal gas pipe 39. It is connected to the. A second unit internal liquid pipe 40 is connected to the other end of the second outdoor heat exchanger 32, and the second unit internal liquid pipe 40 is connected to the second liquid pipe service valve 34 </ b> B via the second expansion valve 33. It is connected to the. A liquid pipe 36 is connected to the second liquid pipe service valve 34B.
On the other hand, the refrigerant suction pipe 41 of the second compressor 30 is connected to a four-way valve 31, and a gas pipe service valve 34 </ b> A is connected to the four-way valve 31 via an in-unit gas pipe 42. A gas pipe 35 is connected to the gas pipe service valve 34A.

The second outdoor unit 3 includes pressure sensors (not shown) for detecting the suction pressure and discharge pressure of the second compressor 30 and the refrigerant pressure in the second outdoor heat exchanger 32, respectively, and the second outdoor unit 3. A temperature sensor (not shown) for detecting the inlet / outlet temperature and the outside air temperature of the heat exchanger 32 is disposed, and the second outdoor control device that controls the second outdoor unit 3 by inputting the detection results of these sensors. (Not shown).
In this embodiment, the 1st outdoor unit 2 functions as a main | base station, and the 1st outdoor control apparatus of this 1st outdoor unit 2 is based on the user instruction input via the remote controller which abbreviate | omitted illustration. It communicates with an outdoor control apparatus and each indoor control apparatus, and performs operation control of this air conditioning apparatus 1 whole.

By the way, since the second outdoor unit 3 includes two pipes of the gas pipe 35 and the liquid pipe 36 extending from the second unit case 34, the two pipes are connected to the three inter-unit pipes 5 as they are. I can't. For this reason, in this configuration, the air conditioner 1 includes the valve body kit 50 that selectively connects the gas pipe 35 extending from the second outdoor unit 3 to the high-pressure gas pipe 7 or the low-pressure gas pipe 6 of the inter-unit pipe 5. Prepare. The valve body kit 50 includes a single second four-way valve 51 as a flow path switching valve and a case body 52 that accommodates the second four-way valve 51, and the gas pipe 35 described above is provided in the case body 52. A connection port to which the high pressure gas pipe 7 and the low pressure gas pipe 6 are connected is formed. A liquid pipe 36 extending from the second unit case 34 is connected to the liquid pipe 8 of the inter-unit pipe 5.
The valve body kit 50 is a dedicated kit for connecting the second outdoor unit 3, which is an existing two-pipe outdoor unit, to the inter-unit pipe 5. One valve unit 50 is provided for each second outdoor unit 3. A valve body kit 50 is provided. According to this, since the existing two-pipe type second outdoor unit 3 can be connected to the inter-unit pipe 5 by using the valve body kit 50, it is connected to the three-pipe type air conditioner 1. Some of the outdoor units that are used can be replaced with expensive three-pipe outdoor units that have complicated piping configurations and can be replaced with existing two-pipe outdoor units that are inexpensive, and the entire air conditioner 1 The price of can be reduced.
Further, the valve body kit 50 is disposed outside the second unit case 34 of the second outdoor unit 3. According to this, the existing two-pipe type second outdoor unit 3 can be used as it is in the three-pipe type air conditioner 1 without changing the pipe configuration. It can be simplified.

The second four-way valve 51 of the valve body kit 50 is provided with four ports A to D, the gas pipe 35 is connected to the first port A, and the low pressure gas pipe 6 is connected to the second port B. The high pressure gas pipe 7 is connected to the third port C, the capillary tube 53 is connected to the fourth port D, and the other end of the capillary tube 53 is connected to the low pressure gas pipe 6.
In the present embodiment, when the second outdoor unit 3 is stopped, the refrigerant pipes (the high pressure gas pipe 7, the low pressure gas pipe 6 and the gas pipe 35 of the inter-unit pipe 5) connected to the second outdoor unit 3 are connected. The refrigerant flow may stop. For this reason, the low pressure gas pipe 6 is connected to the fourth port D via the capillary tube 53 in order to prevent the refrigerant from accumulating in the refrigerant pipes. The fourth port D may be simply closed with a sealing plug or the like without connecting the low-pressure gas pipe 6 to the fourth port D via the capillary tube 53.
The operation of the second four-way valve 51 of the valve body kit 50 is controlled by the second outdoor control device of the second outdoor unit 3.

Next, the operation of the air conditioner 1 will be described.
When all the indoor units 4A to 4D are cooled at the same time, the high-pressure gas pipe 7 is put into a resting state. In this case, as shown in FIG. 1, in the first outdoor unit 2, the first four-way valve 24 guides the refrigerant discharged from the first compressor 20 to the first outdoor heat exchangers 21, 21 (second switching position). In other words, the first port α and the second port β and the third port γ and the fourth port δ of the first four-way valve 24 are switched to positions that communicate with each other, and the electromagnetic on-off valve 27, the first expansion valve 22, 22 is opened. In the second outdoor unit 3, the four-way valve 31 is switched to the cooling operation position in which the refrigerant discharged from the second compressor 30 is guided to the second outdoor heat exchanger 32. In all the indoor units 4A to 4D, the first on-off valves 15A to 15D are closed and the second on-off valves 16A to 16D are opened. In the valve body kit 50, the second four-way valve 51 is switched to a position where the first port A and the second port B and the third port C and the fourth port D communicate with each other.
Thereby, the refrigerant discharged from the first compressor 20 sequentially flows to the refrigerant discharge pipe 25, the first four-way valve 24, the in-unit gas pipe 26, and the first outdoor heat exchangers 21 and 21, and this first outdoor After being condensed and liquefied by the heat exchangers 21, 21, it flows into the liquid pipe 8 of the inter-unit pipe 5 through the first unit liquid pipe 29. On the other hand, the refrigerant discharged from the second compressor 30 sequentially flows to the refrigerant discharge pipe 37, the four-way valve 31, and the second outdoor heat exchanger 32, and is condensed and liquefied by the second outdoor heat exchanger 32. It flows into the liquid pipe 8 of the inter-unit pipe 5 through the pipe 36 and merges with the refrigerant that has flowed out of the first outdoor unit 2 in the liquid pipe 8.
The liquid refrigerant flowing through the liquid pipe 8 is distributed to the indoor expansion valves 11A to 11D of the indoor units 4A to 4D, where the pressure is reduced. The decompressed refrigerant evaporates and vaporizes in each of the indoor heat exchangers 10A to 10D, and then flows into the low pressure gas pipe 6 through the second on-off valves 16A to 16D and the low pressure gas branch pipes 14A to 14D, respectively. The pipe 6 distributes it in two.
One refrigerant flows into the first outdoor unit 2 and is sucked into the first compressor 20 through the refrigerant suction branch pipe 28 </ b> A and the refrigerant suction pipe 28. The other refrigerant flows into the second outdoor unit 3 through the second four-way valve 51 and the gas pipe 35 of the valve body kit 50 and is sucked into the second compressor 30 through the four-way valve 31 and the refrigerant suction pipe 41. . In this way, all the indoor units 4A to 4D are simultaneously cooled by the indoor heat exchangers 10A to 10D acting as evaporators.

When all the indoor units 4A to 4D are heated at the same time, the low-pressure gas pipe 6 is put into a resting state. In this case, as shown in FIG. 2, in the first outdoor unit 2, the first four-way valve 24 communicates the first outdoor heat exchangers 21, 21 and the refrigerant suction pipe 28 (first switching position), that is, The first four-way valve 24 is switched to a position where the first port α and the fourth port δ and the second port β and the third port γ communicate with each other, and the electromagnetic on-off valve 27 is opened, and the first expansion valve 22 is opened. , 22 are adjusted in opening according to the air conditioning load. In the second outdoor unit 3, the four-way valve 31 is switched to the heating operation position in which the refrigerant discharged from the second compressor 30 is guided to the gas pipe 35. In all the indoor units 4A to 4D, the first on-off valves 15A to 15D are opened, and the second on-off valves 16A to 16D are closed. Further, in the valve body kit 50, the second four-way valve 51 is switched to a position where the first port A and the third port C and the second port B and the fourth port D communicate with each other.
Thereby, the refrigerant discharged from the first compressor 20 flows into the high-pressure gas pipe 7 of the inter-unit pipe 5 through the refrigerant discharge pipe 25 and the refrigerant discharge branch pipe 25A. On the other hand, the refrigerant discharged from the second compressor 30 passes through the refrigerant discharge pipe 37, the four-way valve 31, the in-unit gas pipe 42, the gas pipe 35, and the inter-unit pipe 5 through the second four-way valve 51 of the valve body kit 50. The refrigerant flows into the high-pressure gas pipe 7 and merges with the refrigerant that has flowed out of the first outdoor unit 2 in the high-pressure gas pipe 7.
The gas refrigerant flowing through the high-pressure gas pipe 7 is distributed to the high-pressure gas branch pipes 13A to 13D of the indoor units 4A to 4D, and then flows to the first on-off valves 15A to 15D and the indoor heat exchangers 10A to 10D. Each is condensed and liquefied. The liquefied liquid refrigerant flows into the liquid pipe 8 through the liquid branch pipes 18 </ b> A to 18 </ b> D, and is divided into two by the liquid pipe 8.
One refrigerant flows into the first outdoor unit 2 and is distributed to the first expansion valves 22 and 22 where the pressure is reduced. The decompressed refrigerant evaporates and vaporizes in the first outdoor heat exchangers 21 and 21, then merges in the unit gas pipe 26, and enters the first compressor 20 through the first four-way valve 24 and the refrigerant suction pipe 28. Inhaled. The other refrigerant flows into the second outdoor unit 3 through the liquid pipe 36 and is decompressed by the second expansion valve 33. The decompressed refrigerant is evaporated and evaporated in the second outdoor heat exchanger 32 and then sucked into the second compressor 30 through the four-way valve 31 and the refrigerant suction pipe 41. Thus, all the indoor units 4A to 4D are simultaneously heated by the indoor heat exchangers 10A to 10D acting as condensers.

In the case where the indoor units 4A to 4D are operated mainly in cooling and cooling, for example, the indoor units 4A to 4C are cooled and the indoor unit 4D is heated, the low pressure gas pipe 6, the high pressure gas pipe 7 and the liquid pipe All 8 are used.
In this case, as shown in FIG. 3, in the first outdoor unit 2, the first four-way valve 24 is switched to the second switching position, and the first expansion valves 22 and 22 are both closed, so that the first outdoor heat exchanger No refrigerant flows through 21 and 21. This is because the first outdoor unit 2 takes charge of the cooling load in the indoor units 4A to 4C that balances the heating load in the indoor unit 4D, and the second outdoor unit 3 takes charge of the excess cooling load to form a refrigeration cycle. Because.
In the second outdoor unit 3, the four-way valve 31 is switched to the cooling operation position in which the refrigerant discharged from the second compressor 30 is guided to the second outdoor heat exchanger 32. In the indoor units 4A to 4C, the first on-off valves 15A to 15C are closed, the second on-off valves 16A to 16C are opened, and in the indoor unit 4D, the first on-off valve 15D is opened and the second on-off valves are opened. Valve 16D is closed. In the valve body kit 50, the second four-way valve 51 is switched to a position where the first port A and the second port B and the third port C and the fourth port D communicate with each other.
Thereby, the refrigerant discharged from the first compressor 20 flows into the indoor unit 4D through the refrigerant discharge pipe 25, the refrigerant discharge branch pipe 25A, and the high-pressure gas pipe 7. The refrigerant flowing into the indoor unit 4D flows to the indoor heat exchanger 10D through the high-pressure gas branch pipe 13D and the first on-off valve 15D, where it is condensed and liquefied, and then flows into the liquid pipe 8 through the liquid branch pipe 18D. To do.
On the other hand, the refrigerant discharged from the second compressor 30 sequentially flows to the refrigerant discharge pipe 37, the four-way valve 31, and the second outdoor heat exchanger 32, and is condensed and liquefied by the second outdoor heat exchanger 32. It flows into the liquid pipe 8 of the inter-unit pipe 5 through the pipe 36 and merges with the refrigerant that has flowed out of the first outdoor unit 2 in the liquid pipe 8.
The liquid refrigerant flowing through the liquid pipe 8 is distributed to the indoor expansion valves 11A to 11C of the indoor units 4A to 4C, where the pressure is reduced. The decompressed refrigerant evaporates and vaporizes in each of the indoor heat exchangers 10A to 10C, and then flows into the low pressure gas pipe 6 through the second on-off valves 16A to 16C and the low pressure gas branch pipes 14A to 14C, respectively. The pipe 6 distributes it in two.
One refrigerant flows into the first outdoor unit 2 and is sucked into the first compressor 20 through the refrigerant suction branch pipe 28 </ b> A and the refrigerant suction pipe 28. The other refrigerant flows into the second outdoor unit 3 through the second four-way valve 51 and the gas pipe 35 of the valve body kit 50 and is sucked into the second compressor 30 through the four-way valve 31 and the refrigerant suction pipe 41. . In this way, the indoor units 4A to 4C are each cooled by the indoor heat exchangers 10A to 10C acting as evaporators, and the indoor unit 4D is heated by the other indoor heat exchanger 10D acting as a condenser.

  In this configuration, the second outdoor unit 3 is connected to the inter-unit pipe 5 via the valve body kit 50, and the refrigerant condensed in the second outdoor heat exchanger 32 of the second outdoor unit 3 and the indoor heat exchanger The refrigerant condensed in 10D merges in the liquid pipe 8. For this reason, when performing the cooling and heating mixed operation, the condensation pressure (condensation temperature) can be set independently in the indoor heat exchanger 10D and the second outdoor heat exchanger 32 acting as a condenser, for example, When the outside air temperature is low as in winter, the condensation pressure of the second outdoor heat exchanger 32 can be kept lower than the condensation pressure of the indoor heat exchanger 10D, and the work load (consumption) of the second compressor 30 can be reduced. (Electric power) can be reduced.

When the cooling load of the indoor units 4A to 4C increases and cannot be covered by the second outdoor heat exchanger 32 of the second outdoor unit 3, as shown in FIG. While the on-off valve 27 is closed, the first expansion valve 22 on the in-unit branch gas pipe 26A where the electromagnetic on-off valve 27 is not provided is opened, and a part of the refrigerant discharged from the first compressor 20 By guiding to the 1 outdoor heat exchanger 21, this 1st outdoor heat exchanger 21 can be made to act as a condenser.
In this configuration, the first outdoor unit 2 includes two first outdoor heat exchangers 21 and 21 arranged side by side, and opens and closes the electromagnetic on-off valve 27, whereby refrigerant is supplied to each first outdoor heat exchanger 21, The first outdoor heat exchanger 21 used for the air conditioning operation by controlling the operation of the electromagnetic on-off valve 27 according to the load balance between the cooling load and the heating load during the cooling and heating mixed operation, Since the number of 21 can be changed, the operation efficiency during the air conditioning operation can be improved. Moreover, by closing the electromagnetic on-off valve 27, the refrigerant discharged from the first compressor 20 is prevented from flowing into the first outdoor heat exchanger 21 on the side where the electromagnetic on-off valve 27 is provided.

In the case where the indoor units 4A to 4D are mainly heated and cooled and mixed, for example, when the indoor unit 4A is cooled and the indoor units 4A to 4D are heated, the low pressure gas pipe 6, the high pressure gas pipe 7 and the liquid pipe All 8 are used.
In this case, as shown in FIG. 5, in the first outdoor unit 2, the first four-way valve 24 is switched to the first switching position, and the first expansion valves 22 and 22 are both closed, so that the first outdoor heat exchanger No refrigerant flows through 21 and 21.
In the second outdoor unit 3, the four-way valve 31 is switched to the heating operation position in which the refrigerant discharged from the second compressor 30 is guided to the gas pipe 35. In the indoor unit 4A, the first on-off valve 15A is closed and the second on-off valve 16A is opened. In the indoor units 4B to 4D, the first on-off valves 15B to 15D are opened, and the second on-off valve 16B. ~ 16D is closed. Further, in the valve body kit 50, the second four-way valve 51 is switched to a position where the first port A and the third port C and the second port B and the fourth port D communicate with each other.
Thereby, the refrigerant discharged from the first compressor 20 flows into the high-pressure gas pipe 7 of the inter-unit pipe 5 through the refrigerant discharge pipe 25 and the refrigerant discharge branch pipe 25A. On the other hand, the refrigerant discharged from the second compressor 30 passes through the refrigerant discharge pipe 37, the four-way valve 31, the in-unit gas pipe 42, the gas pipe 35, and the inter-unit pipe 5 through the second four-way valve 51 of the valve body kit 50. The refrigerant flows into the high-pressure gas pipe 7 and merges with the refrigerant that has flowed out of the first outdoor unit 2 in the high-pressure gas pipe 7.
The gas refrigerant flowing through the high-pressure gas pipe 7 is distributed to the high-pressure gas branch pipes 13B to 13D of the indoor units 4B to 4D, and then flows to the first on-off valves 15B to 15D and the indoor heat exchangers 10B to 10D. Each is condensed and liquefied. The liquefied liquid refrigerant flows into the liquid pipe 8 through the liquid branch pipes 18B to 18D.
A part of the liquid refrigerant that has flowed into the liquid pipe 8 flows into the indoor unit 4A and is decompressed by the indoor expansion valve 11A of the indoor unit 4A, and the decompressed refrigerant is evaporated by the indoor heat exchanger 10A. . The vaporized gas refrigerant flows into the first outdoor unit 2 through the second on-off valve 16A, the low pressure gas branch pipe 14A, and the low pressure gas pipe 6, and passes through the refrigerant suction branch pipe 28A and the refrigerant suction pipe 28 to the first compressor. 20 is inhaled.
On the other hand, the remainder of the liquid refrigerant flowing into the liquid pipe 8 flows into the second outdoor unit 3 through the liquid pipe 36 and is decompressed by the second expansion valve 33. The decompressed refrigerant is evaporated and evaporated in the second outdoor heat exchanger 32 and then sucked into the second compressor 30 through the four-way valve 31 and the refrigerant suction pipe 41. In this way, the indoor unit 4A is cooled by the indoor heat exchanger 10A acting as an evaporator, and the indoor units 4B to 4D are heated by the other indoor heat exchangers 10B to 10D acting as condensers.

  In this structure, since the 2nd outdoor unit 3 is connected to the inter-unit piping 5 via the valve body kit 50, the refrigerant | coolant condensed with each indoor heat exchanger 10B-10D of each indoor unit 4B-4D. A part can be led to the indoor heat exchanger 10 </ b> A of the indoor unit 4 </ b> A, and the rest can be led to the second outdoor heat exchanger 32 of the second outdoor unit 3. For this reason, in the case of the cooling / heating mixed operation, the evaporation pressure (evaporation temperature) can be set independently in the indoor heat exchanger 10A and the second outdoor heat exchanger 32 acting as an evaporator. For this reason, for example, when the outside air temperature is low as in winter, the evaporation temperature of the indoor heat exchanger 10D is set to be higher than the evaporation temperature of the second outdoor heat exchanger 32 that decreases with the outside air temperature. An appropriate temperature higher than the evaporation temperature of the heat exchanger 32 can be set. As a result, since the evaporation temperature of the indoor heat exchanger 10D is prevented from lowering due to the influence of the outside air temperature as in the prior art, a means for preventing the indoor heat exchanger 10D from freezing is unnecessary. Become.

In addition, when the heating load of the indoor units 4B to 4D increases and cannot be covered by the second outdoor heat exchanger 32 of the second outdoor unit 3, as shown in FIG. While the on-off valve 27 is closed, the first expansion valve 22 on the in-unit branch gas pipe 26A where the electromagnetic on-off valve 27 is not provided is opened, and a part of the refrigerant discharged from the first compressor 20 By guiding to the 1 outdoor heat exchanger 21, this 1st outdoor heat exchanger 21 can be made to act as an evaporator.
In this configuration, the first outdoor unit 2 includes the two first outdoor heat exchangers 21 and 21 arranged in parallel, and can distribute and flow the refrigerant to each of the first outdoor heat exchangers 21 and 21. The number of the first outdoor heat exchangers 21 and 21 used for the air conditioning operation can be changed by controlling the operation of the electromagnetic on-off valve 27 according to the load balance between the cooling load and the heating load during the cooling and heating mixed operation. The driving efficiency can be improved.

As described above, according to the present embodiment, the first outdoor unit 2 including the first compressor 20, the first four-way valve 24, and the first outdoor heat exchangers 21, 21; A high pressure gas pipe 7 connected to a refrigerant discharge branch pipe 25A branched from between the one-way valves 24, a low pressure gas pipe 6 connected to a refrigerant suction branch pipe 28A branched from the refrigerant suction pipe 28 of the first compressor 20, And the inter-unit pipe 5 having the liquid pipe 8 connected to the first outdoor heat exchangers 21, 21 via the first unit liquid pipe 29, the high-pressure gas pipe 7, the low-pressure gas pipe 6 of the inter-unit pipe 5, And a plurality of indoor units 4A to 4D connected to the liquid pipe 8 and having indoor heat exchangers 10A to 10D. The first four-way valve 24 is connected to the low pressure gas pipe 6 and the first outdoor heat at the first switching position. Communicating with the exchangers 21 and 21, the first compression at the second switching position The first outdoor unit 2 connected to the three inter-unit pipes 5 includes a compressor, a four-way valve, and an outdoor heat exchanger so as to communicate the 20 and the first outdoor heat exchangers 21 and 21. It can be constructed by changing a part of the piping configuration of the existing outdoor unit of this piping type, and the production cost can be reduced compared with the case where the three piping outdoor unit is independently developed. .
Further, since the first outdoor unit 2 is configured based on the so-called two-pipe outdoor unit, the first outdoor unit 2 is made more compact than the conventional three-pipe outdoor unit. Can be realized.

  Further, according to this embodiment, the refrigerant discharge pipe 25 of the first compressor 20 is connected to the first port α of the first four-way valve 24, and the first outdoor heat exchangers 21 and 21 are connected to the second port β. Since the refrigerant suction pipe 28 is connected to the third port γ and the refrigerant suction pipe 28 is connected to the fourth port δ via the capillary tube 46, the first compressor 20 is connected via the first four-way valve 24. The first outdoor heat exchangers 21 and 21, the high pressure gas pipe 7 and the low pressure gas pipe 6 can be connected. Therefore, unlike the conventional case, the plurality of indoor units 4A to 4D can be simultaneously cooled by a simple operation such as switching the first four-way valve 24 to the first switching position and the second switching position without requiring a complicated piping configuration. Operation or heating operation can be performed, or these heating operation and cooling operation can be performed in combination.

  Further, according to the present embodiment, the first outdoor unit 2 includes a plurality of first outdoor heat exchangers 21, 21 arranged in parallel, and at least one first outdoor heat exchanger 21 and a first four-way valve. Since the electromagnetic switching valve 27 is provided between the first and second outdoor heat exchangers used for air conditioning operation by controlling the operation of the electromagnetic switching valve 27 according to the load balance between the cooling load and the heating load during the mixed heating and cooling operation. The number of 21 and 21 can be adjusted and the operating efficiency in an air-conditioning driving | operation can be aimed at.

  Further, according to the present embodiment, the second outdoor unit 3 having the second compressor 30 and the second outdoor heat exchanger 32 and connected by two pipes of the gas pipe 35 and the liquid pipe 36 is provided. The liquid pipe 36 of the second outdoor unit 3 is connected to the liquid pipe 8 of the inter-unit pipe 5, and the gas pipe 35 of the second outdoor unit 3 is connected to the unit using the valve body kit 50 having the second four-way valve 51. Since the high pressure gas pipe 7 or the low pressure gas pipe 6 of the inter-line pipe 5 is alternatively connected, the second outdoor unit 3 constituted by a so-called two-pipe type outdoor unit is connected to the three inter-unit pipes 5. be able to. For this reason, the 2nd outdoor unit 3 connected to the three piping type air conditioning apparatus 1 can be comprised in low cost using the existing two piping type outdoor unit, The price of the air conditioning apparatus 1 whole Can be reduced.

  Further, according to the present embodiment, the valve body kit 50 includes a single second four-way valve 51, the gas pipe 35 is connected to the first port A of the second four-way valve 51, and the second port B is connected. Since the low pressure gas pipe 6 is connected, the high pressure gas pipe 7 is connected to the third port C, and the low pressure gas pipe 6 is connected to the fourth port D via the capillary tube 53, the second four-way valve 51 is interposed. With this configuration, the gas pipe 35 of the second outdoor unit 3 can be alternatively connected to the high-pressure gas pipe 7 or the low-pressure gas pipe 6 of the inter-unit pipe 5 and is constituted by a so-called two-pipe type outdoor unit. The second outdoor unit 3 can be connected to the three-pipe type air conditioner 1.

  Further, according to the present embodiment, since the valve body kit 50 is provided outside the second unit case 34 of the second outdoor unit 3, the existing two-pipe type outdoor unit is used as the second outdoor unit 3. The pipe configuration can be used without change, and the configuration of the three-pipe type air conditioner 1 can be simplified.

As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this. For example, in the present embodiment, the air conditioner 1 is configured to include the first outdoor unit 2 and the second outdoor unit 3, but may be configured to include only one first outdoor unit 2, It is good also as a structure provided with two or more 1st outdoor units 2. FIG.
Moreover, in this embodiment, although the valve body kit 50 is set as the structure which provides the 2nd four-way valve 51 as a flow-path switching valve, it is not restricted to this, You may comprise it combining several electromagnetic opening-and-closing valves.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 1st outdoor unit 3 2nd outdoor unit 4A-4D Indoor unit 5 Inter-unit piping 6 Low pressure gas pipe 7 High pressure gas pipe 8 Liquid pipe 20 1st compressor 21 1st outdoor heat exchanger 22 1st expansion Valve 24 First four-way valve 25 Refrigerant discharge pipe 25A Refrigerant discharge branch pipe 27 Electromagnetic open / close valve (open / close valve)
28 refrigerant suction pipe 28A refrigerant suction branch pipe 29 first unit liquid pipe 30 second compressor 31 four-way valve 32 second outdoor heat exchanger 33 second expansion valve 35 gas pipe 36 liquid pipe 37 refrigerant discharge pipe 41 refrigerant suction pipe 41 46 Capillary tube 50 Valve kit 51 Second four-way valve A First port B Second port C Third port D Fourth port α First port β Second port γ Third port δ Fourth port

Claims (6)

A first outdoor unit having a first compressor, a first four-way valve, and a first outdoor heat exchanger; a high-pressure gas pipe branching between the first compressor and the first four-way valve; and the first compressor Inter-unit pipe having a low-pressure gas pipe connected to the refrigerant suction pipe and a liquid pipe connected to the first outdoor heat exchanger, and connected to the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe of the inter-unit pipe A plurality of indoor units having an indoor heat exchanger,
The first four-way valve communicates the low-pressure gas pipe and the first outdoor heat exchanger at a first switching position, and communicates the first compressor and the first outdoor heat exchanger at a second switching position. An air conditioner characterized by that.   Connecting the refrigerant discharge pipe of the first compressor to the first port of the first four-way valve, connecting the first outdoor heat exchanger to the second port, connecting the refrigerant suction pipe to the third port; The air conditioning apparatus according to claim 1, wherein the fourth port is closed, or the refrigerant suction pipe is connected to the fourth port via a capillary tube.   The first outdoor unit includes a plurality of the first outdoor heat exchangers arranged in parallel, and an on-off valve is provided between at least one first outdoor heat exchanger and the first four-way valve. The air conditioner according to claim 1 or 2, characterized in that A second outdoor unit having a second compressor and a second outdoor heat exchanger and connected by two pipes, a gas pipe and a liquid pipe;
The liquid pipe of the second outdoor unit is connected to the liquid pipe of the inter-unit pipe, and the gas pipe of the second outdoor unit is connected to the high pressure of the inter-unit pipe using a valve body kit having a flow path switching valve. The air conditioner according to any one of claims 1 to 3, wherein the air conditioner is alternatively connected to a gas pipe or a low-pressure gas pipe.   The valve body kit includes a single second four-way valve as the flow path switching valve, the gas pipe is connected to a first port of the second four-way valve, and the low-pressure gas pipe is connected to a second port. 5. The high pressure gas pipe is connected to a third port and the fourth port is closed, or the low pressure gas pipe is connected to the fourth port via a capillary tube. The air conditioning apparatus described.   The air conditioner according to claim 4 or 5, wherein the valve body kit is provided outside a housing of the second outdoor unit.

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