JP5772904B2 - Heat recovery type refrigeration system - Google Patents

Description

  The present invention relates to a heat recovery type refrigeration apparatus, in particular, a compressor, a plurality of heat source side heat exchangers, and a plurality of usage side heat exchangers, and functions as a refrigerant radiator. The present invention relates to a heat recovery type refrigeration apparatus capable of recovering heat between use side heat exchangers by sending a refrigerant to a use side heat exchanger functioning as a refrigerant evaporator.

  Conventionally, as shown in patent document 1 (Unexamined-Japanese-Patent No. 5-332637), the compressor, the outdoor heat exchanger as two heat source side heat exchangers, and the indoor heat as several utilization side heat exchangers There is a cooling / heating simultaneous operation type air conditioner which is a kind of heat recovery type refrigeration apparatus including an exchanger. In this heat recovery type refrigeration system, each use side heat exchanger can be individually switched to function as a refrigerant evaporator or radiator, and from the use side heat exchanger functioning as a refrigerant radiator, It is possible to recover heat between the use side heat exchangers by sending the refrigerant to the use side heat exchanger functioning as an evaporator (here, simultaneous cooling and heating operation that performs both cooling operation and heating operation) is possible. It is. In addition, in this heat recovery type refrigeration apparatus, it is possible to switch the two heat source side heat exchangers individually to function as refrigerant evaporators or radiators, and a plurality of use side heats that take into account the above heat recovery. Depending on the heat load (evaporation load or heat radiation load) of the entire exchanger, it is possible to perform switching so that the two heat source side heat exchangers function as a refrigerant evaporator or a heat radiator.

  Here, in the conventional heat recovery type refrigeration apparatus, when heat recovery is performed between the use side heat exchangers, the heat load of the plurality of use side heat exchangers as a whole may be reduced. Therefore, it is necessary to be able to reduce the heat load of the entire two heat source side heat exchangers.

  On the other hand, in the conventional heat recovery refrigeration apparatus, two heat source side heat exchangers (here, those of 3.5 hp and 5.0 hp) having different heat exchange capacities are employed. . And when the heat load of the whole several use side heat exchanger is large, it is made to function both of two heat source side heat exchangers as a heat radiator or evaporator of a refrigerant | coolant, and the whole some use side heat exchanger When the heat load is small, only the heat source side heat exchanger with a small heat exchange capacity is allowed to function as a refrigerant radiator or evaporator.

  However, the above two conventional heat source side heat exchangers have a small heat exchange capacity ratio (the heat source side heat exchanger with a large heat exchange capacity is about 1.4 times that of the heat source side heat exchanger with a small heat exchange capacity. Therefore, even if only the heat source side heat exchanger having a small heat exchange capacity is made to function as a refrigerant radiator or evaporator, there is a limit to the extent that the heat load can be reduced. For this reason, in the conventional heat recovery type refrigeration apparatus, even if only the heat source side heat exchanger having a small heat exchange capacity is made to function as a refrigerant radiator or evaporator, the heat load of the entire plurality of use side heat exchangers It is difficult to cope with small cases.

  On the other hand, in the conventional heat recovery type refrigeration apparatus, one of the two heat source side heat exchangers functions as a refrigerant evaporator, and the other functions as a refrigerant radiator, It is conceivable that the heat load of the entire two heat source side heat exchangers can be reduced by offsetting the evaporation load and the heat radiation load of the heat exchanger to cope with the case where the heat loads of the plurality of use side heat exchangers are small. .

  However, in the response to canceling out the evaporation load and the heat radiation load of the two heat source side heat exchangers, the flow rate of the refrigerant flowing through the two heat source side heat exchangers becomes large. It is necessary to increase the capacity, and there is a concern that the operation performance may be deteriorated when the heat load of the entire plurality of use side heat exchangers is small.

  An object of the present invention includes a compressor, a plurality of heat source side heat exchangers, and a plurality of usage side heat exchangers, and is capable of recovering heat between the usage side heat exchangers. An object of the refrigeration apparatus is to cope with a case where the thermal load of the entire plurality of use side heat exchangers is small while suppressing a decrease in operating performance.

  A heat recovery type refrigeration apparatus according to a first aspect includes a compressor, a plurality of heat source side heat exchangers that can be switched to individually function as a refrigerant evaporator or a radiator, and an individual refrigerant evaporator or heat dissipation. A plurality of use-side heat exchangers that can be switched to function as a heat exchanger, and send refrigerant from a use-side heat exchanger that functions as a refrigerant radiator to a use-side heat exchanger that functions as a refrigerant evaporator Thus, it is possible to recover heat between the use side heat exchangers. The plurality of heat source side heat exchangers are a first heat source side heat exchanger and a second heat source side heat exchanger having a heat exchange capacity 1.8 times to 4.0 times that of the first heat source side heat exchanger. And have.

  Here, as described above, first, the second heat source side heat exchanger is set to 1.8 times or more the heat exchange capacity of the first heat source side heat exchanger. For this reason, when only the first heat source side heat exchanger having a small heat exchange capacity is caused to function as a refrigerant radiator or evaporator, the range in which the heat load can be reduced can be expanded. Thereby, it can respond to the case where the thermal load of the whole some use side heat exchanger is small. Moreover, as described above, the second heat source side heat exchanger is set to 4.0 times or less the heat exchange capacity of the first heat source side heat exchanger. For this reason, one of the two heat source side heat exchangers functions as a refrigerant evaporator and the other functions as a refrigerant radiator, thereby canceling the evaporation load and the heat radiation load of the two heat source side heat exchangers. In the case of performing the countermeasure, the flow rate of the refrigerant flowing through the two heat source side heat exchangers, and hence the operating capacity of the compressor can be saved without being so large. Thereby, it can respond to the case where the thermal load of the whole some utilization side heat exchanger is small, suppressing the fall of driving performance.

  As described above, here, it is possible to cope with a case where the thermal load of the entire plurality of use side heat exchangers is small while suppressing a decrease in operation performance.

In addition, here, a first header is provided on the gas side of the first heat source side heat exchanger for merging and branching the refrigerant with the plurality of heat transfer tubes constituting the first heat source side heat exchanger. In addition, a second header is provided on the gas side of the second heat source side heat exchanger to merge and branch the refrigerant with the plurality of heat transfer tubes constituting the second heat source side heat exchanger. And the 2nd header has a channel cross-sectional area larger than the 1st header.

Here, as described above, when the header is provided on the gas side of each heat source side heat exchanger, the second header having a larger cross-sectional area than the flow path of the first header is used. Thereby, according to the heat exchange capacity | capacitance of each heat source side heat exchanger, a refrigerant | coolant can be appropriately joined and branched between the several heat exchanger tube and header which comprise each heat source side heat exchanger.

  The heat recovery refrigeration apparatus according to the second aspect is the heat recovery refrigeration apparatus according to the first aspect, in which the first heat source side heat exchanger is disposed above the second heat source side heat exchanger. .

  Here, as described above, first, the two heat source side heat exchangers are arranged vertically. At this time, in the heat source side heat exchanger disposed on the lower side, liquid refrigerant tends to accumulate more easily due to the head difference than the heat source side heat exchanger disposed on the upper side. For this reason, if the first heat source side heat exchanger is disposed on the lower side, the heat exchange capacity is small, so that the entire first heat source side heat exchanger is filled with the liquid refrigerant (hereinafter referred to as “liquid immersion”). The desired heat exchange performance may not be obtained.

  Therefore, here, as described above, the first heat source side heat exchanger having a small heat exchange capacity is arranged above the second heat source side heat exchanger having a large heat exchange capacity. For this reason, the 2nd heat source side heat exchanger with large heat exchange capacity will be arranged below, and it can make it difficult to generate liquid immersion. Thereby, when two heat source side heat exchangers are arranged up and down, desired heat exchange performance can be exhibited in both heat source side heat exchangers.

  The heat recovery type refrigeration apparatus according to the third aspect is the first heat source capable of adjusting the opening degree on the liquid side of the first heat source side heat exchanger in the heat recovery type refrigeration apparatus according to the first or second aspect. A side flow rate adjustment valve is connected, and a second heat source side flow rate adjustment valve capable of opening adjustment is connected to the liquid side of the second heat source side heat exchanger. And the 2nd heat source side flow control valve has a larger rated Cv value than the 1st heat source side flow control valve.

  Here, as described above, in connecting the heat source side flow rate adjustment valve to the liquid side of each heat source side heat exchanger, the second heat source side flow rate adjustment valve is larger than the rated Cv value of the first heat source side flow rate adjustment valve. I try to use things. Thereby, according to the heat exchange capacity | capacitance of each heat source side heat exchanger, the flow volume of the refrigerant | coolant which flows through each heat source side heat exchanger can be adjusted appropriately.

  As described above, according to the present invention, the following effects can be obtained.

In the heat recovery type refrigeration apparatus according to the first aspect, it is possible to cope with a case where the thermal load of the entire plurality of usage-side heat exchangers is small while suppressing a decrease in operating performance. And according to the heat exchange capacity | capacitance of each heat source side heat exchanger, a refrigerant | coolant can be appropriately joined and branched between the some heat exchanger tube and header which comprise each heat source side heat exchanger.

  In the heat recovery type refrigeration apparatus according to the second aspect, when two heat source side heat exchangers are arranged one above the other, desired heat exchange performance can be exhibited in both heat source side heat exchangers.

  In the heat recovery refrigeration apparatus according to the third aspect, the flow rate of the refrigerant flowing through each heat source side heat exchanger can be appropriately adjusted according to the heat exchange capacity of each heat source side heat exchanger.

1 is a schematic configuration diagram of a cooling and heating simultaneous operation type air conditioner as one embodiment of a heat recovery type refrigeration apparatus according to the present invention. It is a figure which shows the general | schematic internal structure of the heat-source unit which comprises a cooling-heating simultaneous operation type air conditioning apparatus. It is a figure which shows typically the structure of a heat source side heat exchanger. It is a figure which shows the operation | movement (flow of a refrigerant | coolant) in the air_conditioning | cooling operation mode (large evaporation load) of a cooling / heating simultaneous operation type air conditioner. It is a figure which shows the operation | movement (flow of a refrigerant | coolant) in the air_conditionaing | cooling operation mode (low evaporation load) of the cooling / heating simultaneous operation type air conditioner. It is a figure which shows the operation | movement (flow of a refrigerant | coolant) in the heating operation mode (large heat radiation load) of a cooling / heating simultaneous operation type air conditioner. It is a figure which shows the operation | movement (flow of a refrigerant | coolant) in the heating operation mode (small heat radiation load) of a cooling / heating simultaneous operation type air conditioner. It is a figure which shows the operation | movement (flow of a refrigerant | coolant) in the cooling-heating simultaneous operation mode (evaporation load main body) of a cooling-heating simultaneous operation type air conditioner. It is a figure which shows the operation | movement (flow of a refrigerant | coolant) in the heating / cooling simultaneous operation mode (radiation load main body) of a cooling / heating simultaneous operation type air conditioner. It is a figure which shows the operation | movement (flow of a refrigerant | coolant) in the heating / cooling simultaneous operation mode (evaporation / heat radiation load balance) of a cooling / heating simultaneous operation type air conditioner.

  Hereinafter, an embodiment of a heat recovery type refrigeration apparatus according to the present invention will be described based on the drawings. In addition, the specific structure of the heat recovery refrigeration apparatus according to the present invention is not limited to the following embodiments and modifications thereof, and can be changed without departing from the gist of the invention.

(1) Configuration of Heat Recovery Refrigeration Device (Cooling and Heating Simultaneous Operation Type Air Conditioner) FIG. 1 is a schematic configuration diagram of a cooling and heating simultaneous operation type air conditioning device 1 as an embodiment of a heat recovery type refrigeration device according to the present invention. It is. FIG. 2 is a diagram showing a schematic internal structure of the heat source unit 2 constituting the cooling / heating simultaneous operation type air conditioner 1. FIG. 3 is a diagram schematically showing the structure of the heat source side heat exchangers 24, 25. The cooling and heating simultaneous operation type air conditioner 1 is an apparatus used for air conditioning in a room such as a building by performing a vapor compression refrigeration cycle operation.

  The cooling and heating simultaneous operation type air conditioner 1 mainly includes one heat source unit 2, a plurality of (here, four) use units 3 a, 3 b, 3 c, 3 d, and each use unit 3 a, 3 b, 3 c, 3 d. Connecting units 4a, 4b, 4c, and 4d connected to each other, and refrigerant communication tubes 7 and 8 that connect the heat source unit 2 and the utilization units 3a, 3b, 3c, and 3d via the connection units 4a, 4b, 4c, and 4d. , 9. That is, the vapor compression refrigerant circuit 10 of the cooling and heating simultaneous operation type air conditioner 1 includes a heat source unit 2, utilization units 3a, 3b, 3c, and 3d, connection units 4a, 4b, 4c, and 4d, and a refrigerant communication tube. 7, 8 and 9 are connected to each other. In the cooling / heating simultaneous operation type air conditioner 1, each of the use units 3a, 3b, 3c, and 3d can individually perform the cooling operation or the heating operation, and the cooling operation is performed from the use unit that performs the heating operation. Heat is recovered between the utilization units by sending the refrigerant to the utilization unit to be performed (here, simultaneous cooling / heating operation in which the cooling operation and the heating operation are performed simultaneously) is possible. In addition, in the cooling and heating simultaneous operation type air conditioner 1, the heat load of the heat source unit 2 is changed according to the heat loads of the plurality of utilization units 3a, 3b, 3c, and 3d in consideration of the heat recovery (simultaneous cooling and heating operation). It is configured to balance.

<Usage unit>
The use units 3a, 3b, 3c, and 3d are installed by being embedded or suspended in a ceiling of a room such as a building, or by hanging on a wall surface of the room. The utilization units 3a, 3b, 3c, and 3d are connected to the heat source unit 2 via the refrigerant communication tubes 7, 8, and 9 and the connection units 4a, 4b, 4c, and 4d, and constitute a part of the refrigerant circuit 10. ing.

  Next, the configuration of the usage units 3a, 3b, 3c, and 3d will be described. Since the usage unit 3a and the usage units 3b, 3c, and 3d have the same configuration, only the configuration of the usage unit 3a will be described here, and the configuration of the usage units 3b, 3c, and 3d will be described respectively. Instead of the subscript “a” indicating the respective parts of 3a, the subscript “b”, “c” or “d” is attached, and the description of each part is omitted.

  The usage unit 3a mainly constitutes a part of the refrigerant circuit 10, and includes usage-side refrigerant circuits 13a (in the usage units 3b, 3c, and 3d, usage-side refrigerant circuits 13b, 13c, and 13d, respectively). Yes. The utilization side refrigerant circuit 13a mainly has a utilization side flow rate adjustment valve 51a and a utilization side heat exchanger 52a.

  The usage-side flow rate adjustment valve 51a is an electric expansion valve that can adjust the opening degree connected to the liquid side of the usage-side heat exchanger 52a in order to adjust the flow rate of the refrigerant flowing through the usage-side heat exchanger 52a. is there.

  The use-side heat exchanger 52a is a device for performing heat exchange between the refrigerant and the room air, and includes, for example, a fin-and-tube heat exchanger configured by a large number of heat transfer tubes and fins. Here, the utilization unit 3a has an indoor fan 53a for sucking indoor air into the unit and exchanging heat, and then supplying the indoor air as supply air to the indoor unit 53a. It is possible to exchange heat with the refrigerant flowing through The indoor fan 53a is driven by the indoor fan motor 54a.

  In addition, the usage unit 3a includes a usage-side control unit 50a that controls the operations of the units 51a and 54a constituting the usage unit 3a. The use-side control unit 50a includes a microcomputer and a memory provided for controlling the use unit 3a, and exchanges control signals and the like with a remote controller (not shown). Control signals and the like can be exchanged with the heat source unit 2.

<Heat source unit>
The heat source unit 2 is installed on the rooftop of a building or the like, and is connected to the usage units 3a, 3b, 3c, and 3d via the refrigerant communication tubes 7, 8, and 9, and the usage units 3a, 3b, 3c, The refrigerant circuit 10 is configured with 3d.

  Next, the configuration of the heat source unit 2 will be described. The heat source unit 2 mainly constitutes a part of the refrigerant circuit 10 and has a heat source side refrigerant circuit 12. The heat source side refrigerant circuit 12 mainly includes a compressor 21, a plurality (here, two) heat exchange switching mechanisms 22, 23, and a plurality (here, two) heat source side heat exchangers 24, 25, , A plurality of (here, two) heat source side flow control valves 26 and 27, a receiver 28, a bridge circuit 29, a high / low pressure switching mechanism 30, a liquid side closing valve 31, and a high / low pressure gas side closing valve 32. And a low-pressure gas side closing valve 33.

  Here, the compressor 21 is a device for compressing the refrigerant, and includes, for example, a scroll type positive displacement compressor capable of changing the operation capacity by inverter-controlling the compressor motor 21a.

  When the first heat exchanger switching mechanism 22 causes the first heat source side heat exchanger 24 to function as a refrigerant radiator (hereinafter referred to as “heat dissipation operation state”), the discharge side and the first heat source side of the compressor 21 are used. When the gas side of the heat exchanger 24 is connected (see the solid line of the first heat exchange switching mechanism 22 in FIG. 1) and the first heat source side heat exchanger 24 functions as a refrigerant evaporator (hereinafter referred to as “evaporation”). In the “operating state”, the suction side of the compressor 21 and the gas side of the first heat source side heat exchanger 24 are connected (see the broken line of the first heat exchange switching mechanism 22 in FIG. 1). This is a device capable of switching the refrigerant flow path in the side refrigerant circuit 12, and is composed of, for example, a four-way switching valve. The second heat exchange switching mechanism 23 is connected to the discharge side of the compressor 21 and the second side when the second heat source side heat exchanger 25 functions as a refrigerant radiator (hereinafter referred to as “heat dissipation operation state”). When connecting the gas side of the heat source side heat exchanger 25 (see the solid line of the second heat exchange switching mechanism 23 in FIG. 1), and causing the second heat source side heat exchanger 25 to function as a refrigerant evaporator (hereinafter, referred to as a refrigerant evaporator) In the “evaporation operation state”, the suction side of the compressor 21 and the gas side of the second heat source side heat exchanger 25 are connected (see the broken line of the second heat exchange switching mechanism 23 in FIG. 1). The device is capable of switching the refrigerant flow path in the heat source side refrigerant circuit 12, and is composed of, for example, a four-way switching valve. Then, by changing the switching state of the first heat exchange switching mechanism 22 and the second heat exchange switching mechanism 23, the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 individually evaporate the refrigerant. Switching to function as a heat sink or a radiator is possible.

  The first heat source side heat exchanger 24 is a device for performing heat exchange between the refrigerant and the outdoor air, and includes, for example, a fin-and-tube heat exchanger constituted by a large number of heat transfer tubes and fins. The gas side of the first heat source side heat exchanger 24 is connected to the first heat exchange switching mechanism 22, and the liquid side thereof is connected to the first heat source side flow rate adjustment valve 26. Specifically, the gas side of the first heat source side heat exchanger 24 is a first header 24a for merging and branching refrigerant with a plurality of heat transfer tubes constituting the first heat source side heat exchanger 24. Is provided, and the first header 24 a is connected to the first heat exchange switching mechanism 22. The liquid side of the first heat source side heat exchanger 24 is provided with a first flow divider 24b for merging and branching the refrigerant with a plurality of heat transfer tubes constituting the first heat source side heat exchanger 24. The first flow divider 24b is connected to the first heat source side flow rate adjustment valve 26. The second heat source side heat exchanger 25 is a device for performing heat exchange between the refrigerant and the outdoor air. For example, the second heat source side heat exchanger 25 includes a fin-and-tube heat exchanger constituted by a large number of heat transfer tubes and fins. Become. The gas side of the second heat source side heat exchanger 25 is connected to the second heat exchange switching mechanism 23, and the liquid side thereof is connected to the second heat source side flow rate adjustment valve 27. Specifically, the gas side of the second heat source side heat exchanger 25 has a second header 25a for merging and branching the refrigerant with a plurality of heat transfer tubes constituting the second heat source side heat exchanger 25. The second header 25 a is connected to the second heat exchange switching mechanism 23. The liquid side of the second heat source side heat exchanger 25 is provided with a second flow divider 25b for merging and branching the refrigerant with a plurality of heat transfer tubes constituting the second heat source side heat exchanger 25. The second flow divider 25 b is connected to the second heat source side flow rate adjustment valve 27.

  Here, the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 have different heat exchange capacities, and the second heat source side heat exchanger 25 has a heat exchange capacity different from that of the first heat source side heat exchanger 24. The heat exchange capacity is larger. Specifically, the second heat source side heat exchanger 25 has a heat exchange capacity 1.8 times to 4.0 times that of the first heat source side heat exchanger. Moreover, the 1st heat source side heat exchanger 24 with a small heat exchange capacity | capacitance is arrange | positioned above the 2nd heat source side heat exchanger 25 with a large heat exchange capacity | capacitance. Specifically, the first heat source side heat exchanger 24 and the second heat source side heat exchanger 25 are configured as an integrated heat source side heat exchanger, and the heat transfer tubes constituting the upper part thereof are the first header 24a and the first heat exchanger tube. The second heat source side heat exchanger is made to function as the first heat source side heat exchanger 24 by connecting to the flow divider 24b, and the heat transfer tube constituting the lower part thereof is connected to the second header 25a and the second flow divider 25b. It is made to function as 25. Further, the second header 25a has a larger channel cross-sectional area than the first header 24a. Specifically, the inner diameter size of the second header 25a is made larger than the inner diameter size of the first header 24a. The heat source unit 2 has an outdoor fan 34 for sucking outdoor air into the unit, exchanging heat, and then discharging the air outside the unit. The outdoor air and the heat source side heat exchangers 24 and 25 are connected to the heat source unit 2. It is possible to exchange heat with the flowing refrigerant. The outdoor fan 34 is driven by an outdoor fan motor 34a. Here, a suction port 2 a for sucking outdoor air is formed on the side surface of the heat source unit 2, and a discharge port 2 b for discharging outdoor air is formed on the top surface of the heat source unit 2. The outdoor fan 34 is disposed on the upper part of the heat source unit 2.

  The first heat source side flow rate adjustment valve 26 is configured to adjust the opening degree connected to the liquid side of the first heat source side heat exchanger 24 in order to adjust the flow rate of the refrigerant flowing through the first heat source side heat exchanger 24. It is a possible electric expansion valve. The second heat source side flow rate adjustment valve 27 has an opening degree connected to the liquid side of the second heat source side heat exchanger 25 in order to adjust the flow rate of the refrigerant flowing through the second heat source side heat exchanger 25 and the like. It is an electric expansion valve that can be adjusted. Here, the first heat source side flow rate adjustment valve 26 and the second heat source side flow rate adjustment valve 27 have different rated Cv values, and the second heat source side flow rate adjustment valve 27 has a higher rated Cv value than the first heat source side flow rate adjustment valve 26. The rated Cv value is larger.

  The receiver 28 is a container for temporarily storing the refrigerant flowing between the heat source side heat exchangers 24 and 25 and the use side refrigerant circuits 13a, 13b, 13c, and 13d. A receiver inlet pipe 28 a is provided in the upper part of the receiver 28, and a receiver outlet pipe 28 b is provided in the lower part of the receiver 28. The receiver inlet pipe 28a is provided with a receiver inlet on / off valve 28c capable of opening / closing control. The inlet pipe 28 a and the outlet pipe 28 b of the receiver 28 are connected between the heat source side heat exchangers 24 and 25 and the liquid side shut-off valve 31 via the bridge circuit 29.

  In the bridge circuit 29, when the refrigerant flows from the heat source side heat exchangers 24, 25 toward the liquid side closing valve 31 side, and when the refrigerant flows from the liquid side closing valve 31 side to the heat source side heat exchangers 24, 25 side. In any case where the refrigerant flows in the direction, the refrigerant has a function of causing the refrigerant to flow into the receiver 28 through the receiver inlet pipe 28a and out of the receiver 28 through the receiver outlet pipe 28b. The bridge circuit 29 has four check valves 29a, 29b, 29c, and 29d. The inlet check valve 29a is a check valve that only allows the refrigerant to flow from the heat source side heat exchangers 24 and 25 to the receiver inlet pipe 28a. The inlet check valve 29b is a check valve that only allows refrigerant to flow from the liquid-side closing valve 31 side to the receiver inlet pipe 28a. That is, the inlet check valves 29a and 29b have a function of circulating the refrigerant from the heat source side heat exchangers 24 and 25 side or the liquid side closing valve 31 side to the receiver inlet pipe 28a. The outlet check valve 29c is a check valve that allows only the refrigerant to flow from the receiver outlet pipe 28b to the liquid side closing valve 31 side. The outlet check valve 29d is a check valve that only allows refrigerant to flow from the receiver outlet pipe 28b to the heat source side heat exchangers 24 and 25. That is, the outlet check valves 29c and 29d have a function of circulating the refrigerant from the receiver outlet pipe 28b to the heat source side heat exchangers 24 and 25 side or the liquid side closing valve 31 side.

  The high / low pressure switching mechanism 30 compresses the high-pressure gas refrigerant discharged from the compressor 21 when the high-pressure gas refrigerant is sent to the use-side refrigerant circuits 13a, 13b, 13c, and 13d (hereinafter referred to as “radiation load main operation state”). The discharge side of the compressor 21 and the high / low pressure gas side shut-off valve 32 (see the broken line of the high / low pressure switching mechanism 30 in FIG. 1), and the high pressure gas refrigerant discharged from the compressor 21 is used on the use side refrigerant circuit 13a, When not sent to 13b, 13c, 13d (hereinafter referred to as "evaporative load main operation state"), the high / low pressure gas side shut-off valve 32 and the suction side of the compressor 21 are connected (high in FIG. 1). (Refer to the solid line of the low-pressure switching mechanism 30), which is a device capable of switching the refrigerant flow path in the heat source side refrigerant circuit 12, and includes, for example, a four-way switching valve.

  The liquid side shut-off valve 31, the high-low pressure gas side shut-off valve 32, and the low-pressure gas side shut-off valve 33 are provided at the connection ports with external devices and piping (specifically, the refrigerant communication pipes 7, 8, and 9). It is a valve. The liquid side closing valve 31 is connected to the receiver inlet pipe 28a or the receiver outlet pipe 28b via the bridge circuit 29. The high / low pressure gas side closing valve 32 is connected to the high / low pressure switching mechanism 30. The low pressure gas side closing valve 33 is connected to the suction side of the compressor 21.

  Further, the heat source unit 2 includes a heat source side control unit 20 that controls the operation of each unit 21 a, 22, 23, 26, 27, 28 c, 30, 34 a constituting the heat source unit 2. The heat source side control unit 20 includes a microcomputer and a memory provided to control the heat source unit 2, and uses side control units 50a, 50b, 50c of the usage units 3a, 3b, 3c, 3d. , 50d can exchange control signals and the like.

<Connection unit>
The connection units 4a, 4b, 4c, and 4d are installed together with the use units 3a, 3b, 3c, and 3d in a room such as a building. The connection units 4 a, 4 b, 4 c, 4 d are interposed between the use units 3, 4, 5 and the heat source unit 2 together with the refrigerant communication tubes 9, 10, 11, and constitute a part of the refrigerant circuit 10. ing.

  Next, the configuration of the connection units 4a, 4b, 4c, and 4d will be described. Since the connection unit 4a and the connection units 4b, 4c, and 4d have the same configuration, only the configuration of the connection unit 4a will be described here, and the configuration of the connection units 4b, 4c, and 4d will be described respectively. In place of the subscript “a” indicating the respective parts of 4a, the subscript “b”, “c” or “d” is attached, and the description of each part is omitted.

  The connection unit 4a mainly constitutes a part of the refrigerant circuit 10, and includes a connection side refrigerant circuit 14a (in the connection units 4b, 4c, and 4d, connection side refrigerant circuits 14b, 14c, and 14d, respectively). Yes. The connection side refrigerant circuit 14a mainly includes a liquid connection pipe 61a and a gas connection pipe 62a.

  The liquid connection pipe 61a connects the liquid refrigerant communication pipe 7 and the use side flow rate adjustment valve 51a of the use side refrigerant circuit 13a.

  The gas connection pipe 62a includes a high pressure gas connection pipe 63a connected to the high and low pressure gas refrigerant communication pipe 8, a low pressure gas connection pipe 64a connected to the low pressure gas refrigerant communication pipe 9, and a high pressure gas connection pipe 63a and a low pressure gas connection. It has a merged gas connection pipe 65a that merges the pipe 64a. The merged gas connection pipe 65a is connected to the gas side of the use side heat exchanger 52a of the use side refrigerant circuit 13a. The high pressure gas connection pipe 63a is provided with a high pressure gas on / off valve 66a capable of opening / closing control, and the low pressure gas connection pipe 64a is provided with a low pressure gas on / off valve 67a capable of opening / closing control.

  When the use unit 3a performs the cooling operation, the connection unit 4a opens the low-pressure gas on / off valve 67a and allows the refrigerant flowing into the liquid connection pipe 61a through the liquid refrigerant communication pipe 7 to be used on the use-side refrigerant circuit. The refrigerant evaporated by heat exchange with the indoor air in the use side heat exchanger 52a through the use side flow rate adjustment valve 51a of 13a and through the combined gas connection pipe 65a and the low pressure gas connection pipe 64a is sent through the use side heat exchanger 52a. It can function to return to the low-pressure gas refrigerant communication tube 9. Further, the connection unit 4a closes the low pressure gas on / off valve 67a and opens the high pressure gas on / off valve 66a when the use unit 3a performs the heating operation, and passes through the high / low pressure gas refrigerant communication pipe 8. The refrigerant flowing into the high-pressure gas connection pipe 63a and the merged gas connection pipe 65a is sent to the use-side heat exchanger 52a of the use-side refrigerant circuit 13a, and the refrigerant radiated by heat exchange with room air in the use-side heat exchanger 52a is It can function to return to the liquid refrigerant communication pipe 7 through the use side flow rate adjustment valve 51a and the liquid connection pipe 61a. Since this function has not only the connection unit 4a but also the connection units 4b, 4c, and 4d, the use side heat exchangers 52a, 52b, 52c, and 52d are connected by the connection units 4a, 4b, 4c, and 4d. Can be switched individually to function as a refrigerant evaporator or radiator.

  Moreover, the connection unit 4a has the connection side control part 60a which controls operation | movement of each part 66a, 67a which comprises the connection unit 4a. The connection-side control unit 60a includes a microcomputer and a memory provided for controlling the connection unit 60a, and exchanges control signals and the like with the use-side control unit 50a of the use unit 3a. Can be done.

  As described above, the use side refrigerant circuits 13a, 13b, 13c, 13d, the heat source side refrigerant circuit 12, the refrigerant communication tubes 7, 8, 9 and the connection side refrigerant circuits 14a, 14b, 14c, 14d are connected. Thus, the refrigerant circuit 10 of the cooling and heating simultaneous operation type air conditioner 1 is configured. In the cooling / heating simultaneous operation type air conditioner 1, for example, it is possible to perform the cooling / heating simultaneous operation in which the utilization units 3a, 3b perform the heating operation while the utilization units 3a, 3b perform the cooling operation. At this time, between the use units 3a, 3b, 3c and 3d by sending the refrigerant from the use side heat exchangers 52a and 52b functioning as a refrigerant radiator to the use side heat exchangers 52c and 52d functioning as a refrigerant evaporator Heat recovery is performed in That is, the cooling and heating simultaneous operation type air conditioner 1 has a compressor 21 and a plurality of (here, two) heat source side heat exchangers 24 and 25 that can be switched to function individually as refrigerant evaporators or radiators. And a plurality of (in this case, four) use-side heat exchangers 52a, 52b, 52c, and 52d that can be switched to function as refrigerant evaporators or radiators. Constructing a heat recovery refrigeration system capable of recovering heat between the use side heat exchangers by sending the refrigerant from the functioning use side heat exchanger to the use side heat exchanger functioning as a refrigerant evaporator Yes. Here, as described above, the second heat source side heat exchanger 25 is set to 1.8 times or more the heat exchange capacity of the first heat source side heat exchanger 24.

(2) Operation of Heat Recovery Refrigeration Device (Cooling and Heating Simultaneous Operation Type Air Conditioner) Next, the operation of the cooling and heating simultaneous operation type air conditioner 1 will be described.

  The operation modes of the cooling and heating simultaneous operation type air conditioner 1 are the cooling operation mode (large evaporation load), the cooling operation mode (low evaporation load), the heating operation mode (large heat radiation load), and the heating operation mode (low heat radiation load). ), Cooling / heating simultaneous operation mode (evaporation load main), cooling / heating simultaneous operation mode (heat dissipation load main), and cooling / heating simultaneous operation mode (evaporation / heat dissipation load balance). Here, in the cooling operation mode (large evaporation load), there is only a usage unit that performs a cooling operation (that is, an operation in which the use side heat exchanger functions as an evaporator of refrigerant), and the evaporation load of the entire usage unit is This is an operation mode in which both the heat source side heat exchangers 24 and 25 function as a refrigerant radiator. In the cooling operation mode (low evaporation load), there is only a usage unit that performs a cooling operation (that is, an operation in which the use side heat exchanger functions as a refrigerant evaporator). This is an operation mode in which only the heat source side heat exchanger 24 functions as a refrigerant radiator. In the heating operation mode (large heat radiation load), there is only a use unit that performs the heating operation (that is, the operation in which the use side heat exchanger functions as a refrigerant radiator), and the heat source side with respect to the heat radiation load of the entire use unit. This is an operation mode in which both the heat exchangers 24 and 25 function as a refrigerant evaporator. In the heating operation mode (small heat radiation load), there is only a utilization unit that performs a heating operation (that is, an operation in which the use-side heat exchanger functions as a refrigerant radiator). In this operation mode, only the heat source side heat exchanger 24 functions as a refrigerant evaporator. The cooling and heating simultaneous operation mode (evaporation load main) is a cooling unit (that is, an operation in which the use-side heat exchanger functions as a refrigerant evaporator) and a heating operation (that is, the use-side heat exchanger releases heat of the refrigerant). Use unit that performs an operation that functions as a heat exchanger), and the heat load of the entire use unit is mainly the evaporation load, only the first heat source side heat exchanger 24 is connected to the evaporation load of the entire use unit. This is an operation mode for functioning as a refrigerant radiator. The cooling and heating simultaneous operation mode (mainly a heat radiation load) is a mode in which a cooling unit (that is, an operation in which the use-side heat exchanger functions as a refrigerant evaporator) and a heating operation (that is, the use-side heat exchanger releases heat of the refrigerant). Use unit that performs an operation that functions as a heat exchanger), and the heat load of the entire use unit is mainly the heat radiation load, only the first heat source side heat exchanger 24 is connected to the heat radiation load of the whole use unit. This is an operation mode for functioning as a refrigerant evaporator. The cooling and heating simultaneous operation mode (evaporation / radiation load balance) is performed by using a cooling unit (that is, an operation in which the use side heat exchanger functions as a refrigerant evaporator) and a heating operation (ie, the use side heat exchanger is a refrigerant). Use unit that performs an operation that functions as a heat radiator), and when the evaporation load and the heat radiation load of the entire utilization unit are balanced, the first heat source side heat exchanger 24 functions as a refrigerant radiator, In addition, this is an operation mode in which the second heat source side heat exchanger 25 functions as a refrigerant evaporator.

  In addition, operation | movement of the heating-and-cooling simultaneous operation type air conditioning apparatus 1 containing these operation modes is performed by said control part 20, 50a, 50b, 50c, 50d, 60a, 60b, 60c, 60d.

<Cooling operation mode (high evaporation load)>
In the cooling operation mode (large evaporation load), for example, all of the usage units 3a, 3b, 3c, and 3d are in the cooling operation (that is, all of the usage side heat exchangers 52a, 52b, 52c, and 52d are refrigerant evaporators). When both the heat source side heat exchangers 24 and 25 function as refrigerant radiators, the refrigerant circuit 10 of the air conditioner 1 is configured as shown in FIG. (For the flow, see the arrow attached to the refrigerant circuit 10 in FIG. 4).

  Specifically, in the heat source unit 2, the first heat exchange switching mechanism 22 is switched to the heat radiation operation state (the state indicated by the solid line of the first heat exchange switching mechanism 22 in FIG. 4), and the second heat exchange switching mechanism is selected. By switching 23 to the heat radiation operation state (the state indicated by the solid line of the second heat exchange switching mechanism 23 in FIG. 4), both the heat source side heat exchangers 24 and 25 function as a refrigerant radiator. ing. Further, the high / low pressure switching mechanism 30 is switched to the evaporative load main operation state (the state indicated by the solid line of the high / low pressure switching mechanism 30 in FIG. 4). Further, the opening amounts of the heat source side flow rate adjusting valves 26 and 27 are adjusted, and the receiver inlet opening / closing valve 28c is in an open state. In the connection units 4a, 4b, 4c and 4d, the use units 3a and 3b are opened by opening the high pressure gas on / off valves 66a, 66b, 66c and 66d and the low pressure gas on / off valves 67a, 67b, 67c and 67d. 3c, 3d use side heat exchangers 52a, 52b, 52c, 52d all function as refrigerant evaporators, and use units 3a, 3b, 3c, 3d use side heat exchangers 52a, 52b, 52c, All of 52d and the suction side of the compressor 21 of the heat source unit 2 are connected via the high and low pressure gas refrigerant communication pipe 8 and the low pressure gas refrigerant communication pipe 9. In the usage units 3a, 3b, 3c and 3d, the usage-side flow rate adjustment valves 51a, 51b, 51c and 51d are adjusted in opening.

  In such a refrigerant circuit 10, the high-pressure gas refrigerant compressed and discharged by the compressor 21 is sent to both the heat source side heat exchangers 24 and 25 through the heat exchange switching mechanisms 22 and 23. The high-pressure gas refrigerant sent to the heat source side heat exchangers 24 and 25 radiates heat by exchanging heat with outdoor air as a heat source supplied by the outdoor fan 34 in the heat source side heat exchangers 24 and 25. To do. The refrigerant that has radiated heat in the heat source side heat exchangers 24 and 25 is adjusted in flow rate in the heat source side flow rate adjusting valves 26 and 27, and then merges and passes through the inlet check valve 29a and the receiver inlet on / off valve 28c. Sent to. The refrigerant sent to the receiver 28 is temporarily stored in the receiver 28, and then sent to the liquid refrigerant communication tube 6 through the outlet check valve 29 c and the liquid side closing valve 31.

  And the refrigerant | coolant sent to the liquid refrigerant communication pipe | tube 6 is branched into four, and is sent to the liquid connection pipes 61a, 61b, 61c, 61d of each connection unit 4a, 4b, 4c, 4d. The refrigerant sent to the liquid connection pipes 61a, 61b, 61c, 61d is sent to the usage-side flow rate adjustment valves 51a, 51b, 51c, 51d of the usage units 3a, 3b, 3c, 3d.

  The refrigerant sent to the usage-side flow rate adjustment valves 51a, 51b, 51c, 51d is adjusted in flow rate at the usage-side flow rate adjustment valves 51a, 51b, 51c, 51d, and then used-side heat exchangers 52a, 52b, 52c. , 52d evaporates into a low-pressure gas refrigerant by exchanging heat with the indoor air supplied by the indoor fans 53a, 53b, 53c, 53d. On the other hand, the room air is cooled and supplied to the room, and the use units 3a, 3b, 3c, and 3d are cooled. Then, the low-pressure gas refrigerant is sent to the merged gas connection pipes 65a, 65b, 65c, and 65d of the connection units 4a, 4b, 4c, and 4d.

  The low-pressure gas refrigerant sent to the merged gas connection pipes 65a, 65b, 65c, 65d passes through the high-pressure gas on / off valves 66a, 66b, 66c, 66d and the high-pressure gas connection pipes 63a, 63b, 63c, 63d. The gas refrigerant communication pipe 8 is sent and merged, and the low pressure gas on / off valves 67a, 67b, 67c and 67d and the low pressure gas connection pipes 64a, 64b, 64c and 64d are sent to the low pressure gas refrigerant communication pipe 9 and merged. .

  Then, the low-pressure gas refrigerant sent to the gas refrigerant communication pipes 8 and 9 is returned to the suction side of the compressor 21 through the gas-side stop valves 32 and 33 and the high-low pressure switching mechanism 30.

  In this way, the operation in the cooling operation mode (large evaporation load) is performed.

<Cooling operation mode (low evaporation load)>
In the cooling operation mode (low evaporation load), for example, only the use unit 3a performs the cooling operation (that is, only the use side heat exchanger 52a functions as a refrigerant evaporator), and only the first heat source side heat exchanger 24 is operated. 5 functions as a refrigerant radiator, the refrigerant circuit 10 of the air conditioner 1 is configured as shown in FIG. 5 (see the arrows attached to the refrigerant circuit 10 in FIG. 5 for the refrigerant flow). ).

  Specifically, in the heat source unit 2, the first heat exchange switching mechanism 22 is switched to the heat radiation operation state (the state indicated by the solid line of the first heat exchange switching mechanism 22 in FIG. 5), thereby Only the heat exchanger 24 is made to function as a refrigerant radiator. Further, the high / low pressure switching mechanism 30 is switched to the evaporative load main operation state (the state shown by the solid line of the high / low pressure switching mechanism 30 in FIG. 5). Further, the opening degree of the first heat source side flow rate adjustment valve 26 is adjusted, the second heat source side flow rate adjustment valve 27 is in a closed state, and the receiver inlet on-off valve 28c is in an open state. In the connection units 4a, 4b, 4c and 4d, the high pressure gas on / off valve 66a and the low pressure gas on / off valve 67a are opened, and the high pressure gas on / off valves 66b, 66c and 66d and the low pressure gas on / off valve 67b By closing 67c and 67d, only the use side heat exchanger 52a of the use unit 3a functions as a refrigerant evaporator, and the use side heat exchanger 52a of the use unit 3a and the compressor 21 of the heat source unit 2 are used. Are connected via a high-low pressure gas refrigerant communication pipe 8 and a low-pressure gas refrigerant communication pipe 9. In the usage unit 3a, the usage-side flow rate adjustment valve 51a is adjusted in opening, and in the usage units 3b, 3c, and 3d, the usage-side flow rate adjustment valves 51b, 51c, and 51d are in a closed state.

  In such a refrigerant circuit 10, the high-pressure gas refrigerant compressed and discharged by the compressor 21 is sent only to the first heat source side heat exchanger 24 through the first heat exchange switching mechanism 22. The high-pressure gas refrigerant sent to the first heat source side heat exchanger 24 dissipates heat by exchanging heat with outdoor air as a heat source supplied by the outdoor fan 34 in the first heat source side heat exchanger 24. To do. The refrigerant that has radiated heat in the first heat source side heat exchanger 24 is adjusted in flow rate in the first heat source side flow rate adjustment valve 26 and then sent to the receiver 28 through the inlet check valve 29a and the receiver inlet opening / closing valve 28c. The refrigerant sent to the receiver 28 is temporarily stored in the receiver 28, and then sent to the liquid refrigerant communication tube 6 through the outlet check valve 29 c and the liquid side closing valve 31.

  The refrigerant sent to the liquid refrigerant communication pipe 6 is sent only to the liquid connection pipe 61a of the connection unit 4a. And the refrigerant | coolant sent to the liquid connection pipe | tube 61a of the connection unit 4a is sent to the utilization side flow control valve 51a of the utilization unit 3a.

  The refrigerant sent to the usage-side flow rate adjustment valve 51a is subjected to heat exchange with the indoor air supplied by the indoor fan 53a in the usage-side heat exchanger 52a after the flow rate is adjusted in the usage-side flow rate adjustment valve 51a. As a result, it evaporates into a low-pressure gas refrigerant. On the other hand, the room air is cooled and supplied to the room, and only the use unit 3a is cooled. Then, the low-pressure gas refrigerant is sent to the merged gas connection pipe 65a of the connection unit 4a.

  The low-pressure gas refrigerant sent to the merged gas connection pipe 65a is sent to the high-low pressure gas refrigerant communication pipe 8 through the high-pressure gas on-off valve 66a and the high-pressure gas connection pipe 63a, and at the same time the low-pressure gas on-off valve 67a and low-pressure gas. It is sent to the low-pressure gas refrigerant communication pipe 9 through the connection pipe 64a.

  Then, the low-pressure gas refrigerant sent to the gas refrigerant communication pipes 8 and 9 is returned to the suction side of the compressor 21 through the gas-side stop valves 32 and 33 and the high-low pressure switching mechanism 30.

  In this way, the operation in the cooling operation mode (low evaporation load) is performed.

<Heating operation mode (high heat radiation load)>
In the heating operation mode (large heat radiation load), for example, all of the usage units 3a, 3b, 3c, and 3d are in the heating operation (that is, all of the usage-side heat exchangers 52a, 52b, 52c, and 52d are refrigerant radiators). When both the heat source side heat exchangers 24 and 25 function as refrigerant evaporators, the refrigerant circuit 10 of the air conditioner 1 is configured as shown in FIG. (For the flow, see the arrow attached to the refrigerant circuit 10 in FIG. 6).

  Specifically, in the heat source unit 2, the first heat exchange switching mechanism 22 is switched to the evaporation operation state (the state indicated by the broken line of the first heat exchange switching mechanism 22 in FIG. 6), and the second heat exchange switching mechanism is selected. 23 is switched to the evaporation operation state (the state indicated by the broken line of the second heat exchange switching mechanism 23 in FIG. 6), so that both the heat source side heat exchangers 24 and 25 function as a refrigerant evaporator. ing. Further, the high / low pressure switching mechanism 30 is switched to the heat radiation load main operation state (the state indicated by the broken line of the high / low pressure switching mechanism 30 in FIG. 6). Further, the opening amounts of the heat source side flow rate adjusting valves 26 and 27 are adjusted, and the receiver inlet opening / closing valve 28c is in an open state. In the connection units 4a, 4b, 4c, and 4d, the high pressure gas on / off valves 66a, 66b, 66c, and 66d are opened, and the low pressure gas on / off valves 67a, 67b, 67c, and 67d are closed, thereby using the use unit 3a. 3b, 3c, 3d use side heat exchangers 52a, 52b, 52c, 52d all function as refrigerant radiators, and use units 3a, 3b, 3c, 3d use side heat exchangers 52a, 52b, All of 52c and 52d and the discharge side of the compressor 21 of the heat source unit 2 are connected via the high and low pressure gas refrigerant communication pipe 8. In the usage units 3a, 3b, 3c and 3d, the usage-side flow rate adjustment valves 51a, 51b, 51c and 51d are adjusted in opening.

  In such a refrigerant circuit 10, the high-pressure gas refrigerant compressed and discharged by the compressor 21 is sent to the high / low pressure gas refrigerant communication pipe 8 through the high / low pressure switching mechanism 30 and the high / low pressure gas side closing valve 32.

  The high-pressure gas refrigerant sent to the high-low pressure gas refrigerant communication pipe 8 is branched into four and sent to the high-pressure gas connection pipes 63a, 63b, 63c, 63d of the connection units 4a, 4b, 4c, 4d. It is done. The high-pressure gas refrigerant sent to the high-pressure gas connection pipes 63a, 63b, 63c, 63d passes through the high-pressure gas on / off valves 66a, 66b, 66c, 66d and the merged gas connection pipes 65a, 65b, 65c, 65d. It is sent to the use side heat exchangers 52a, 52b, 52c, 52d of 3b, 3c, 3d.

  The high-pressure gas refrigerant sent to the use side heat exchangers 52a, 52b, 52c, and 52d is supplied by the indoor fans 53a, 53b, 53c, and 53d in the use side heat exchangers 52a, 52b, 52c, and 52d. Heat is dissipated by exchanging heat with indoor air. On the other hand, indoor air is heated and supplied indoors, and heating operation of utilization unit 3a, 3b, 3c, 3d is performed. The refrigerant radiated in the use side heat exchangers 52a, 52b, 52c, 52d is adjusted in flow rate in the use side flow rate adjusting valves 51a, 51b, 51c, 51d, and then the liquid connection pipes of the connection units 4a, 4b, 4c, 4d. 61a, 61b, 61c and 61d.

  Then, the refrigerant sent to the liquid connection pipes 61a, 61b, 61c, 61d is sent to the liquid refrigerant communication pipe 6 and merges.

  Then, the refrigerant sent to the liquid refrigerant communication tube 6 is sent to the receiver 28 through the liquid side closing valve 31, the inlet check valve 29b, and the receiver inlet opening / closing valve 28c. The refrigerant sent to the receiver 28 is temporarily stored in the receiver 28 and then sent to both the heat source side flow rate adjustment valves 26 and 27 through the outlet check valve 29d. The refrigerant sent to the heat source side flow rate adjustment valves 26, 27 is adjusted in flow rate in the heat source side flow rate adjustment valves 26, 27, and then is supplied to the outdoor source 34 by the outdoor fan 34 in the heat source side heat exchangers 24, 25. By evaporating with air, it evaporates into a low-pressure gas refrigerant and is sent to the heat exchange switching mechanisms 22 and 23. The low-pressure gas refrigerant sent to the heat exchange switching mechanisms 22 and 23 merges and returns to the suction side of the compressor 21.

  In this way, the operation in the heating operation mode (large heat radiation load) is performed.

<Heating operation mode (low heat radiation load)>
In the heating operation mode (small heat radiation load), for example, only the usage unit 3a performs the heating operation (that is, only the usage-side heat exchanger 52a functions as a refrigerant radiator), and only the first heat source-side heat exchanger 24 is operated. 7 functions as a refrigerant evaporator, the refrigerant circuit 10 of the air conditioner 1 is configured as shown in FIG. 7 (see the arrows attached to the refrigerant circuit 10 in FIG. 7 for the refrigerant flow). ).

  Specifically, in the heat source unit 2, the first heat source switching mechanism 22 is switched to the evaporation operation state (the state indicated by the broken line of the first heat exchange switching mechanism 22 in FIG. 7), thereby Only the heat exchanger 24 functions as a refrigerant evaporator. Further, the high / low pressure switching mechanism 30 is switched to the heat radiation load main operation state (the state indicated by the broken line of the high / low pressure switching mechanism 30 in FIG. 7). Further, the opening degree of the first heat source side flow rate adjustment valve 26 is adjusted, the second heat source side flow rate adjustment valve 27 is in a closed state, and the receiver inlet on-off valve 28c is in an open state. In the connection units 4a, 4b, 4c and 4d, the high pressure gas on / off valve 66a is opened, and the high pressure gas on / off valves 66b, 66c and 66d and the low pressure gas on / off valves 67a, 67b, 67c and 67d are closed. As a result, only the utilization side heat exchanger 52a of the utilization unit 3a functions as a refrigerant radiator, and the utilization side heat exchanger 52a of the utilization unit 3a and the discharge side of the compressor 21 of the heat source unit 2 have high and low pressure gas. It is in a connected state via the refrigerant communication pipe 8. In the usage unit 3a, the usage-side flow rate adjustment valve 51a is adjusted in opening, and in the usage units 3b, 3c, and 3d, the usage-side flow rate adjustment valves 51b, 51c, and 51d are in a closed state.

  In such a refrigerant circuit 10, the high-pressure gas refrigerant compressed and discharged by the compressor 21 is sent to the high / low pressure gas refrigerant communication pipe 8 through the high / low pressure switching mechanism 30 and the high / low pressure gas side closing valve 32.

  The high-pressure gas refrigerant sent to the high-low pressure gas refrigerant communication pipe 8 is sent only to the high-pressure gas connection pipe 63a of the connection unit 4a. The high-pressure gas refrigerant sent to the high-pressure gas connection pipe 63a is sent to the use-side heat exchanger 52a of the use unit 3a through the high-pressure gas on-off valve 66a and the merged gas connection pipe 65a.

  The high-pressure gas refrigerant sent to the usage-side heat exchanger 52a dissipates heat by exchanging heat with indoor air supplied by the indoor fan 53a in the usage-side heat exchanger 52a. On the other hand, indoor air is heated and supplied indoors, and only the utilization unit 3a is heated. The refrigerant radiated in the use side heat exchanger 52a is sent to the liquid connection pipe 61a of the connection unit 4a after the flow rate is adjusted in the use side flow rate adjustment valve 51a.

  The refrigerant sent to the liquid connection pipe 61 a is sent to the liquid refrigerant communication pipe 6.

  Then, the refrigerant sent to the liquid refrigerant communication tube 6 is sent to the receiver 28 through the liquid side closing valve 31, the inlet check valve 29b, and the receiver inlet opening / closing valve 28c. The refrigerant sent to the receiver 28 is temporarily stored in the receiver 28 and then sent only to the first heat source side flow rate adjustment valve 26 through the outlet check valve 29d. The refrigerant sent to the first heat source side flow rate adjustment valve 26 is adjusted in flow rate in the first heat source side flow rate adjustment valve 26, and then is supplied to the outdoor side supplied by the outdoor fan 34 in the first heat source side heat exchanger 24. By evaporating with air, it evaporates into a low-pressure gas refrigerant and is sent to the first heat exchange switching mechanism 22. Then, the low-pressure gas refrigerant sent to the first heat exchange switching mechanism 22 is returned to the suction side of the compressor 21.

  Thus, the operation in the heating operation mode (small heat radiation load) is performed.

<Cooling and heating simultaneous operation mode (evaporation load mainly)>
Cooling and heating simultaneous operation mode (evaporation load main), for example, the usage units 3a, 3b, and 3c are in cooling operation, and the usage unit 3d is in heating operation (that is, the usage-side heat exchangers 52a, 52b, and 52c are evaporated of refrigerant) When the first heat source side heat exchanger 24 functions as a refrigerant radiator, the air conditioner 1 of the air conditioner 1 is operated. The refrigerant circuit 10 is configured as shown in FIG. 8 (refer to the arrows attached to the refrigerant circuit 10 in FIG. 8 for the refrigerant flow).

  Specifically, in the heat source unit 2, the first heat exchange switching mechanism 22 is switched to the heat dissipation operation state (the state indicated by the solid line of the first heat exchange switching mechanism 22 in FIG. 8), thereby Only the heat exchanger 24 is made to function as a refrigerant radiator. Further, the high / low pressure switching mechanism 30 is switched to the heat radiation load main operation state (the state indicated by the broken line of the high / low pressure switching mechanism 30 in FIG. 8). Further, the opening degree of the first heat source side flow rate adjustment valve 26 is adjusted, the second heat source side flow rate adjustment valve 27 is in a closed state, and the receiver inlet on-off valve 28c is in an open state. In the connection units 4a, 4b, 4c, and 4d, the high-pressure gas on-off valve 66d and the low-pressure gas on-off valves 67a, 67b, and 67c are opened, and the high-pressure gas on-off valves 66a, 66b, 66c, and the low-pressure gas By closing the on-off valve 67d, the use side heat exchangers 52a, 52b, 52c of the use units 3a, 3b, 3c function as a refrigerant evaporator, and the use side heat exchanger 52d of the use unit 3d. Through the low-pressure gas refrigerant communication pipe 9 between the utilization side heat exchangers 52a, 52b, 52c of the utilization units 3a, 3b, 3c and the suction side of the compressor 21 of the heat source unit 2. The use side heat exchanger 52d of the use unit 3d and the discharge side of the compressor 21 of the heat source unit 2 are connected to the high / low pressure gas refrigerant communication pipe 8 in a connected state. To have become the connected state. In the usage units 3a, 3b, 3c and 3d, the usage-side flow rate adjustment valves 51a, 51b, 51c and 51d are adjusted in opening.

  In such a refrigerant circuit 10, a part of the high-pressure gas refrigerant compressed and discharged by the compressor 21 passes through the high / low pressure switching mechanism 30 and the high / low pressure gas side shut-off valve 32. The remainder is sent to the first heat source side heat exchanger 24 through the first heat exchange switching mechanism 22.

  Then, the high-pressure gas refrigerant sent to the high-low pressure gas refrigerant communication pipe 8 is sent to the high-pressure gas connection pipe 63d of the connection unit 4d. The high-pressure gas refrigerant sent to the high-pressure gas connection pipe 63d is sent to the use-side heat exchanger 52d of the use unit 3d through the high-pressure gas on-off valve 66d and the merged gas connection pipe 65d.

  The high-pressure gas refrigerant sent to the use side heat exchanger 52d dissipates heat by exchanging heat with the indoor air supplied by the indoor fan 53d in the use side heat exchanger 52d. On the other hand, the indoor air is heated and supplied indoors, and the heating operation of the utilization unit 3d is performed. The refrigerant that has radiated heat in the use side heat exchanger 52d is sent to the liquid connection pipe 61d of the connection unit 4d after the flow rate is adjusted in the use side flow rate adjustment valve 51d.

  The high-pressure gas refrigerant sent to the first heat source side heat exchanger 24 dissipates heat by exchanging heat with outdoor air as a heat source supplied by the outdoor fan 34 in the first heat source side heat exchanger 24. To do. The refrigerant that has radiated heat in the first heat source side heat exchanger 24 is adjusted in flow rate in the first heat source side flow rate adjustment valve 26 and then sent to the receiver 28 through the inlet check valve 29a and the receiver inlet opening / closing valve 28c. The refrigerant sent to the receiver 28 is temporarily stored in the receiver 28, and then sent to the liquid refrigerant communication tube 6 through the outlet check valve 29 c and the liquid side closing valve 31.

  The refrigerant radiated in the use side heat exchanger 52d and sent to the liquid connection pipe 61d is sent to the liquid refrigerant communication pipe 6 and radiated in the first heat source side heat exchanger 24 to be radiated. It merges with the refrigerant sent to.

  And the refrigerant | coolant merged in the liquid refrigerant connection pipe | tube 6 is branched into three, and is sent to the liquid connection pipes 61a, 61b, 61c of each connection unit 4a, 4b, 4c. Then, the refrigerant sent to the liquid connection pipes 61a, 61b, 61c is sent to the use side flow rate adjusting valves 51a, 51b, 51c of the use units 3a, 3b, 3c.

  The refrigerant sent to the usage-side flow rate adjustment valves 51a, 51b, 51c is adjusted in flow rate at the usage-side flow rate adjustment valves 51a, 51b, 51c, and then the indoor fan in the usage-side heat exchangers 52a, 52b, 52c. By exchanging heat with the indoor air supplied by 53a, 53b, 53c, it evaporates and becomes a low-pressure gas refrigerant. On the other hand, the room air is cooled and supplied to the room, and the use units 3a, 3b, and 3c are cooled. Then, the low-pressure gas refrigerant is sent to the merged gas connection pipes 65a, 65b, and 65c of the connection units 4a, 4b, and 4c.

  The low-pressure gas refrigerant sent to the merged gas connection pipes 65a, 65b, 65c is sent to the low-pressure gas refrigerant communication pipe 9 through the low-pressure gas on-off valves 67a, 67b, 67c and the low-pressure gas connection pipes 64a, 64b, 64c. Be merged.

  Then, the low-pressure gas refrigerant sent to the low-pressure gas refrigerant communication pipe 9 is returned to the suction side of the compressor 21 through the gas-side closing valve 33.

  Thus, the operation in the cooling and heating simultaneous operation mode (evaporation load main body) is performed. In the cooling / heating simultaneous operation mode (mainly evaporation load), as described above, the use side heat exchangers 52a, 52b, 52c functioning as the refrigerant evaporator are changed from the use side heat exchanger 52d functioning as the refrigerant radiator. Heat is recovered between the use-side heat exchangers 52a, 52b, 52c, and 52d by sending the refrigerant.

<Cooling and heating simultaneous operation mode (heat radiation load mainly)>
Simultaneous cooling and heating operation mode (mainly heat radiation load), for example, the usage units 3a, 3b, and 3c perform heating operation, and the usage unit 3d performs cooling operation (that is, the usage-side heat exchangers 52a, 52b, and 52c release heat from the refrigerant). When the use side heat exchanger 52d functions as a refrigerant evaporator and only the first heat source side heat exchanger 24 functions as a refrigerant evaporator, the air conditioner 1 The refrigerant circuit 10 is configured as shown in FIG. 9 (refer to the arrows attached to the refrigerant circuit 10 in FIG. 9 for the refrigerant flow).

  Specifically, in the heat source unit 2, by switching the first heat exchange switching mechanism 22 to the evaporation operation state (the state indicated by the broken line of the first heat exchange switching mechanism 22 in FIG. 9), the first heat source switching mechanism 22 Only the heat exchanger 24 functions as a refrigerant evaporator. Further, the high / low pressure switching mechanism 30 is switched to the heat radiation load main operation state (the state indicated by the broken line of the high / low pressure switching mechanism 30 in FIG. 9). Further, the opening degree of the first heat source side flow rate adjustment valve 26 is adjusted, the second heat source side flow rate adjustment valve 27 is in a closed state, and the receiver inlet on-off valve 28c is in an open state. In the connection units 4a, 4b, 4c and 4d, the high pressure gas on / off valves 66a, 66b and 66c and the low pressure gas on / off valve 67d are opened, and the high pressure gas on / off valve 66d and the low pressure gas on / off valve 67a, By closing 67b and 67c, the utilization side heat exchangers 52a, 52b and 52c of the utilization units 3a, 3b and 3c function as refrigerant radiators, and the utilization side heat exchanger 52d of the utilization unit 3d. As a refrigerant evaporator, the utilization side heat exchanger 52d of the utilization unit 3d and the suction side of the compressor 21 of the heat source unit 2 are connected via the low-pressure gas refrigerant communication pipe 9, and The use side heat exchangers 52a, 52b, 52c of the use units 3a, 3b, 3c and the discharge side of the compressor 21 of the heat source unit 2 connect the high / low pressure gas refrigerant communication pipe 8. To have become the connected state. In the usage units 3a, 3b, 3c and 3d, the usage-side flow rate adjustment valves 51a, 51b, 51c and 51d are adjusted in opening.

  In such a refrigerant circuit 10, the high-pressure gas refrigerant compressed and discharged by the compressor 21 is sent to the high / low pressure gas refrigerant communication pipe 8 through the high / low pressure switching mechanism 30 and the high / low pressure gas side closing valve 32.

  The high-pressure gas refrigerant sent to the high-low pressure gas refrigerant communication pipe 8 is branched into three and sent to the high-pressure gas connection pipes 63a, 63b, 63c of the connection units 4a, 4b, 4c. The high-pressure gas refrigerant sent to the high-pressure gas connection pipes 63a, 63b, and 63c passes through the high-pressure gas on / off valves 66a, 66b, and 66c and the merged gas connection pipes 65a, 65b, and 65c, and the use side of the use units 3a, 3b, and 3c. It is sent to the heat exchangers 52a, 52b, 52c.

  The high-pressure gas refrigerant sent to the use side heat exchangers 52a, 52b, 52c exchanges heat with the indoor air supplied by the indoor fans 53a, 53b, 53c in the use side heat exchangers 52a, 52b, 52c. To dissipate heat. On the other hand, room air is heated and supplied indoors, and heating operation of utilization unit 3a, 3b, 3c is performed. The refrigerant that has dissipated heat in the usage-side heat exchangers 52a, 52b, and 52c is adjusted in flow rate in the usage-side flow rate adjustment valves 51a, 51b, and 51c, and then into the liquid connection pipes 61a, 61b, and 61c of the connection units 4a, 4b, and 4c. Sent.

  Then, the refrigerant sent to the liquid connection pipes 61a, 61b, 61c, 61d is sent to the liquid refrigerant communication pipe 6 and merges.

  A part of the refrigerant merged in the liquid refrigerant communication pipe 6 is sent to the liquid connection pipe 61d of the connection unit 4d, and the rest passes through the liquid side closing valve 31, the inlet check valve 29b, and the receiver inlet opening / closing valve 28c. It is sent to the receiver 28.

  The refrigerant sent to the liquid connection pipe 61d of the connection unit 4d is sent to the usage-side flow rate adjustment valve 51d of the usage unit 3d.

  The refrigerant sent to the use-side flow rate adjustment valve 51d is subjected to heat exchange with the indoor air supplied by the indoor fan 53d in the use-side heat exchanger 52d after the flow rate is adjusted in the use-side flow rate adjustment valve 51d. As a result, it evaporates into a low-pressure gas refrigerant. On the other hand, the indoor air is cooled and supplied to the room, and the cooling operation of the utilization unit 3d is performed. Then, the low-pressure gas refrigerant is sent to the merged gas connection pipe 65d of the connection unit 4d.

  The low-pressure gas refrigerant sent to the merged gas connection pipe 65d is sent to the low-pressure gas refrigerant communication pipe 9 through the low-pressure gas on-off valve 67d and the low-pressure gas connection pipe 64d.

  Then, the low-pressure gas refrigerant sent to the low-pressure gas refrigerant communication pipe 9 is returned to the suction side of the compressor 21 through the gas-side closing valve 33.

  The refrigerant sent to the receiver 28 is temporarily stored in the receiver 28 and then sent to the first heat source side flow rate adjustment valve 26 through the outlet check valve 29d. The refrigerant sent to the first heat source side flow rate adjustment valve 26 is adjusted in flow rate in the first heat source side flow rate adjustment valve 26, and then is supplied to the outdoor side supplied by the outdoor fan 34 in the first heat source side heat exchanger 24. By evaporating with air, it evaporates into a low-pressure gas refrigerant and is sent to the first heat exchange switching mechanism 22. The low-pressure gas refrigerant sent to the first heat exchange switching mechanism 22 merges with the low-pressure gas refrigerant returned to the suction side of the compressor 21 through the low-pressure gas refrigerant communication tube 9 and the gas-side shut-off valve 33, Returned to the suction side of the compressor 21.

  In this way, the operation in the simultaneous cooling and heating operation mode (mainly heat radiation load) is performed. In the cooling / heating simultaneous operation mode (mainly heat radiation load), as described above, the use side heat exchangers 52a, 52b, 52c functioning as the refrigerant radiator are changed to the use side heat exchanger 52d functioning as the refrigerant evaporator. Heat is recovered between the use-side heat exchangers 52a, 52b, 52c, and 52d by sending the refrigerant.

<Simultaneous cooling and heating operation mode (evaporation / radiation load balance)>
Simultaneous cooling / heating operation mode (evaporation / radiation load balance), for example, the usage units 3a, 3b are in cooling operation, and the usage units 3c, 3d are in heating operation (that is, the usage-side heat exchangers 52a, 52b are evaporated). And the use side heat exchangers 52c and 52d function as a refrigerant radiator), the first heat source side heat exchanger 24 functions as a refrigerant radiator, and the second heat source. When the side heat exchanger 25 functions as a refrigerant evaporator, the refrigerant circuit 10 of the air conditioner 1 is configured as shown in FIG. 10 (the refrigerant flow is attached to the refrigerant circuit 10 of FIG. 10). (See the arrow that appears.)

  Specifically, in the heat source unit 2, the first heat exchange switching mechanism 22 is switched to the heat dissipation operation state (the state indicated by the solid line of the first heat exchange switching mechanism 22 in FIG. 10), and the second heat exchange mechanism By switching the switching mechanism 23 to the evaporation operation state (the state indicated by the broken line of the second heat exchange switching mechanism 23 in FIG. 10), the first heat source side heat exchanger 24 functions as a refrigerant radiator, and The second heat source side heat exchanger 25 is made to function as a refrigerant evaporator. Further, the high / low pressure switching mechanism 30 is switched to the heat radiation load main operation state (the state indicated by the broken line of the high / low pressure switching mechanism 30 in FIG. 10). Moreover, the opening degree of the heat source side flow rate adjustment valves 26 and 27 is adjusted. In the connection units 4a, 4b, 4c and 4d, the high pressure gas on / off valves 66c and 66d and the low pressure gas on / off valves 67a and 67b are opened, and the high pressure gas on / off valves 66a and 66b and the low pressure gas on / off valve are opened. By closing 67c and 67d, the usage-side heat exchangers 52a and 52b of the usage units 3a and 3b function as a refrigerant evaporator, and the usage-side heat exchangers 52c and 52d of the usage units 3c and 3d And the use side heat exchangers 52a, 52b of the use units 3a, 3b and the suction side of the compressor 21 of the heat source unit 2 are connected via the low-pressure gas refrigerant communication pipe 9 And the use side heat exchangers 52c, 52d of the use units 3c, 3d and the discharge side of the compressor 21 of the heat source unit 2 connect the high / low pressure gas refrigerant communication pipe 8. To have become the connected state. In the usage units 3a, 3b, 3c and 3d, the usage-side flow rate adjustment valves 51a, 51b, 51c and 51d are adjusted in opening.

  In such a refrigerant circuit 10, a part of the high-pressure gas refrigerant compressed and discharged by the compressor 21 passes through the high / low pressure switching mechanism 30 and the high / low pressure gas side shut-off valve 32. The remainder is sent to the first heat source side heat exchanger 24 through the first heat exchange switching mechanism 22.

  Then, the high-pressure gas refrigerant sent to the high-low pressure gas refrigerant communication pipe 8 is sent to the high-pressure gas connection pipes 63c, 63d of the connection units 4c, 4d. The high-pressure gas refrigerant sent to the high-pressure gas connection pipes 63c and 63d is sent to the use-side heat exchangers 52c and 52d of the use units 3c and 3d through the high-pressure gas on-off valves 66c and 66d and the merged gas connection pipes 65c and 65d. It is done.

  The high-pressure gas refrigerant sent to the use side heat exchangers 52c and 52d dissipates heat by exchanging heat with the indoor air supplied by the indoor fans 53c and 53d in the use side heat exchangers 52c and 52d. . On the other hand, room air is heated and supplied indoors, and heating operation of utilization units 3c and 3d is performed. The refrigerant that has dissipated heat in the usage-side heat exchangers 52c and 52d is sent to the liquid connection pipes 61c and 61d of the connection units 4c and 4d after the flow rate is adjusted in the usage-side flow rate adjustment valves 51c and 51d.

  And the refrigerant | coolant which thermally radiated in the utilization side heat exchangers 52c and 52d and was sent to the liquid connection pipes 61c and 61d is sent to the liquid refrigerant connection pipe 6, and merges.

  And the refrigerant | coolant merged in the liquid refrigerant connection pipe | tube 6 is branched into two, and is sent to the liquid connection pipes 61a and 61b of each connection unit 4a and 4b. Then, the refrigerant sent to the liquid connection pipes 61a and 61b is sent to the usage-side flow rate adjustment valves 51a and 51b of the usage units 3a and 3b.

  The refrigerant sent to the usage-side flow rate adjustment valves 51a and 51b is adjusted by the usage-side flow rate adjustment valves 51a and 51b, and then supplied by the indoor fans 53a and 53b in the usage-side heat exchangers 52a and 52b. By exchanging heat with the indoor air, it evaporates and becomes a low-pressure gas refrigerant. On the other hand, the room air is cooled and supplied to the room, and the use units 3a and 3b are cooled. Then, the low-pressure gas refrigerant is sent to the merged gas connection pipes 65a and 65b of the connection units 4a and 4b.

  The low-pressure gas refrigerant sent to the merged gas connection pipes 65a and 65b is sent to and merged with the low-pressure gas refrigerant communication pipe 9 through the low-pressure gas on-off valves 67a and 67b and the low-pressure gas connection pipes 64a and 64b.

  Then, the low-pressure gas refrigerant sent to the low-pressure gas refrigerant communication pipe 9 is returned to the suction side of the compressor 21 through the gas-side closing valve 33.

  The high-pressure gas refrigerant sent to the first heat source side heat exchanger 24 dissipates heat by exchanging heat with outdoor air as a heat source supplied by the outdoor fan 34 in the first heat source side heat exchanger 24. To do. Then, most of the refrigerant radiated in the first heat source side heat exchanger 24 is sent to the second heat source side flow rate adjustment valve 27 after passing through the first heat source side flow rate adjustment valve 26. For this reason, the refrigerant dissipated in the first heat source side heat exchanger 24 is not sent to the liquid refrigerant communication tube 6 through the receiver 28, the bridge circuit 29, and the liquid side shut-off valve 31. The refrigerant sent to the second heat source side flow rate adjustment valve 27 is adjusted in flow rate in the second heat source side flow rate adjustment valve 27, and then is supplied outside by the outdoor fan 34 in the second heat source side heat exchanger 25. By performing heat exchange with air, it evaporates into a low-pressure gas refrigerant and is sent to the second heat exchange switching mechanism 23. The low-pressure gas refrigerant sent to the second heat exchange switching mechanism 23 merges with the low-pressure gas refrigerant returned to the suction side of the compressor 21 through the low-pressure gas refrigerant communication pipe 9 and the gas-side shut-off valve 33, Returned to the suction side of the compressor 21.

  Thus, the operation in the cooling and heating simultaneous operation mode (evaporation / heat radiation load balance) is performed. In the cooling / heating simultaneous operation mode (evaporation / heat radiation load balance), as described above, the use side heat exchangers 52a and 52d functioning as refrigerant refrigerants from the use side heat exchangers 52c and 52d functioning as refrigerant refrigerants, Heat is recovered between the use side heat exchangers 52a, 52b, 52c, and 52d by sending the refrigerant to 52b. In the cooling / heating simultaneous operation mode (evaporation / heat radiation load balance), as described above, the first heat source side heat exchanger 24 functions as a refrigerant radiator, and the second heat source side heat exchanger 25 is operated as a refrigerant. By making it function as an evaporator, the countermeasure which cancels | balances the evaporation load and heat radiation load of the two heat source side heat exchangers 24 and 25 is performed.

(3) Features of the heat recovery type refrigeration apparatus (cooling / heating simultaneous operation type air conditioning apparatus) The cooling / heating simultaneous operation type air conditioning apparatus 1 has the following characteristics.

<A>
Here, as described above, first, the second heat source side heat exchanger 25 is set to 1.8 times or more the heat exchange capacity of the first heat source side heat exchanger 24. For this reason, when only the first heat source side heat exchanger 24 having a small heat exchange capacity is made to function as a refrigerant radiator or evaporator, for example, the cooling operation mode (low evaporation load) or the cooling and heating simultaneous operation mode (evaporation) is performed. The range in which the heat load can be reduced is expanded compared to the conventional case where the ratio of heat exchange capacity is small in the heating operation mode (small heat radiation load) and the cooling / heating simultaneous operation mode (heat radiation load main). be able to. Thereby, it can respond to the case where the heat load of the whole some use side heat exchanger 52a, 52b, 52c, 52d is small. In addition, here, as described above, the second heat source side heat exchanger 25 is set to 4.0 times or less the heat exchange capacity of the first heat source side heat exchanger 24. For this reason, one of the two heat source side heat exchangers 24 and 25 functions as a refrigerant evaporator, and the other functions as a refrigerant radiator, thereby evaporating loads of the two heat source side heat exchangers 24 and 25. For example, in the cooling / heating simultaneous operation mode (evaporation / radiation load balance), the flow rate of the refrigerant flowing through the two heat source side heat exchangers 24 and 25, and the compressor 21 The operating capacity can be kept small. Thereby, it can respond to the case where the thermal load of the whole some use side heat exchanger 52a, 52b, 52c, 52d is small, suppressing the fall of driving performance.

  As described above, here, it is possible to cope with a case where the heat load of the entire plurality of use side heat exchangers 52a, 52b, 52c, and 52d is small while suppressing a decrease in operation performance.

<B>
Here, as described above, first, the two heat source side heat exchangers 24 and 25 are arranged vertically. At this time, in the heat source side heat exchanger disposed on the lower side, liquid refrigerant tends to accumulate more easily due to the head difference than the heat source side heat exchanger disposed on the upper side. For this reason, if the first heat source side heat exchanger 24 is disposed on the lower side, since the heat exchange capacity is small, the entire first heat source side heat exchanger 24 is filled with the liquid refrigerant (hereinafter referred to as “liquid liquid”). There is a risk that desired heat exchange performance may not be obtained.

  Therefore, here, as described above, the first heat source side heat exchanger 24 having a small heat exchange capacity is arranged above the second heat source side heat exchanger 25 having a large heat exchange capacity. For this reason, the 2nd heat source side heat exchanger 25 with large heat exchange capacity will be arranged below, and it can make it difficult to generate liquid immersion. Thereby, when the two heat source side heat exchangers 24 and 25 are arranged one above the other, the desired heat exchange performance can be exhibited in both the heat source side heat exchangers 24 and 25.

<C>
Here, as described above, when the heat source side flow rate adjustment valves 26 and 27 are connected to the liquid side of the heat source side heat exchangers 24 and 25, the second heat source side flow rate adjustment valve 27 is replaced with the first heat source side flow rate adjustment valve. A value larger than the rated Cv value of 26 is used. Thereby, according to the heat exchange capacity | capacitance of each heat source side heat exchanger 24 and 25, the flow volume of the refrigerant | coolant which flows through each heat source side heat exchanger 24 and 25 can be adjusted appropriately.

<D>
Here, as described above, in providing the header on the gas side of each heat source side heat exchanger 24, 25, the second header 25a should be larger than the flow path cross-sectional area of the first header 24a. Yes. Thereby, according to the heat exchange capacity | capacitance of each heat source side heat exchanger 24,25, a refrigerant | coolant is appropriately merged between the some heat exchanger tube which comprises each heat source side heat exchanger 24,25, and header 24a, 25a. And branching can be performed.

(4) Modifications In the above embodiment, the heat recovery type refrigeration apparatus to which the present invention is applied has been described with reference to the configuration example of the cooling and heating simultaneous operation type air conditioner 1, but the present invention is not limited thereto. is not. That is, the use side that functions as a refrigerant evaporator from the use side heat exchanger that functions as a refrigerant radiator includes a compressor, a plurality of heat source side heat exchangers, and a plurality of utilization side heat exchangers The present invention can be applied to any configuration that can recover heat between the use-side heat exchangers by sending a refrigerant to the heat exchanger.

  The present invention includes a compressor, a plurality of heat source side heat exchangers, and a plurality of utilization side heat exchangers, and functions as a refrigerant evaporator from a utilization side heat exchanger that functions as a refrigerant radiator. The present invention is widely applicable to a heat recovery type refrigeration apparatus capable of recovering heat between use side heat exchangers by sending a refrigerant to the use side heat exchanger.

1 Cooling and heating simultaneous operation type air conditioner (heat recovery type refrigeration system)
21 Compressor 24 1st heat source side heat exchanger 24a 1st header 25 2nd heat source side heat exchanger 25a 2nd header 26 1st heat source side flow control valve 27 2nd heat source side flow control valve 52a, 52b, 52c, 52d Use side heat exchanger

JP-A-5-332637

Claims (3)

Compressor (21), a plurality of heat source side heat exchangers (24, 25) capable of switching to individually function as a refrigerant evaporator or radiator, and switching to individually function as a refrigerant evaporator or radiator A plurality of usage-side heat exchangers (52a, 52b, 52c, 52d) capable of operating from the usage-side heat exchanger functioning as the refrigerant radiator to the usage-side heat functioning as the refrigerant evaporator. In the heat recovery type refrigeration apparatus capable of recovering heat between the use side heat exchangers by sending a refrigerant to the exchanger,
The plurality of heat source side heat exchangers are a first heat source side heat exchanger and a second heat source side heat exchanger having a heat exchange capacity 1.8 times to 4.0 times that of the first heat source side heat exchanger. It has a door,
Provided on the gas side of the first heat source side heat exchanger is a first header (24a) for merging and branching the refrigerant with a plurality of heat transfer tubes constituting the first heat source side heat exchanger. And
Provided on the gas side of the second heat source side heat exchanger is a second header (25a) for merging and branching the refrigerant with the plurality of heat transfer tubes constituting the second heat source side heat exchanger. And
The second header has a larger flow path cross-sectional area than the first header,
Heat recovery type refrigeration system (1). The first heat source side heat exchanger (24) is disposed above the second heat source side heat exchanger (25).
The heat recovery type refrigeration apparatus (1) according to claim 1. A first heat source side flow rate adjustment valve (26) capable of adjusting the opening is connected to the liquid side of the first heat source side heat exchanger (24),
A second heat source side flow rate adjustment valve (27) capable of opening degree adjustment is connected to the liquid side of the second heat source side heat exchanger (25);
The second heat source side flow rate adjustment valve has a larger rated Cv value than the first heat source side flow rate adjustment valve,
The heat recovery type refrigeration apparatus (1) according to claim 1 or 2.

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