JP6222493B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly to an air conditioner provided with a non-power source driven compressor driven by an engine and a power source driven compressor driven by electric power.

  Generally, a multi-type air conditioner is known in which a plurality of outdoor unit groups and a plurality of indoor unit groups are connected by piping, and the number of outdoor units operated is controlled according to the air conditioning load. As an electric drive outdoor unit with a built-in power-driven compressor and a non-power-drive outdoor unit with a built-in non-power-driven compressor, it can be expanded even when there is not enough power capacity. A so-called hybrid air conditioner that can achieve leveling has been proposed. (For example, refer to Patent Document 1).

  Further, in the gas heat pump, at the time of partial load, the thermal efficiency of the gas engine decreases, and the operation efficiency as an air conditioner decreases. In order to avoid this, the displacement volume of the non-power source driven compressor driven by the gas engine is made larger than that of the power source driven compressor, the power source driven compressor is mainly operated during partial load, and the gas engine is operated at high load. A control method for driving the main body has also been proposed (see, for example, Patent Document 2).

JP 05-340624 A JP 2003-069931 A

  However, when using a combination of a power-driven outdoor unit incorporating a power-driven compressor and a non-power-driven outdoor unit incorporating a non-power-driven compressor having a larger displacement volume than the power-driven compressor (for example, (When the capacity of the non-power source driven compressor is 20 HP and the capacity of the power source driven compressor is 10 HP in total 30 HP), the non-power source driven compressor discharges more refrigeration oil than the power source driven compressor. There was a problem that the refrigerating machine oil became deficient and the operation reliability was impaired.

  The present invention solves the above-mentioned problem, and in the case of using a combination of a power-driven outdoor unit and a non-power-driven outdoor unit, the refrigerator oil of the non-power-driven compressor built in the non-power-driven outdoor unit An object of the present invention is to provide an air conditioner that can sufficiently secure the above and improve the operation reliability of a non-power source driven compressor.

  This specification includes all the contents of the Japanese patent application and Japanese Patent Application No. 2014-026758 filed on February 14, 2014.

In order to solve the above-described problems, an air conditioner according to a first aspect of the present invention includes a power source driving outdoor unit on which a power source driving compressor driven by electric power is mounted, and a non-power source driving compressor driven by a driving source other than electric power. In an air conditioner in which a non-power-driven outdoor unit on which is mounted is connected in parallel to an inter-unit pipe extending from at least one indoor unit, the inlet position of the non-power-driven compressor is the suction position of the power-driven compressor. as a vertically lower side than the mouth position, characterized in that said power supply driving the outdoor unit and the non-power driving the outdoor unit is installed.

  As a result, since the suction port position of the non-power source driven compressor is below the suction port position of the power source drive compressor, the refrigeration oil whose specific gravity is heavier than the refrigerant easily returns to the non-power source drive compressor. The operation reliability of the non-power source driven compressor can be improved without depleting the refrigeration oil of the non-power source drive compressor.

  According to a second aspect of the present invention, in the air conditioner of the first aspect, a non-power source driven compressor oil separator that separates refrigeration oil from the refrigerant discharged from the non-power source driven compressor, and a refrigerant refrigerated from the refrigerant discharged from the power source driven compressor Power supply driven compressor oil separator that separates machine oil, the flow resistance of the pipe that flows refrigeration oil from the non-power supply driven compressor oil separator to the suction pipe of the non-power supply driven compressor, the power supply from the power supply driven compressor oil separator It is characterized by being made smaller than the flow path resistance of the pipe through which the refrigeration oil flows into the suction pipe of the drive compressor.

  Thereby, the amount of refrigerating machine oil returning from the oil separator of the non-power source driven compressor to the non-power source driven compressor is larger than the amount of refrigerating machine oil returning from the power source driven compressor oil separator to the power source driven compressor. Therefore, in the present invention, in addition to the effect of the first invention, in particular, when the non-power supply driven compressor is started at a low outside temperature, or when the operating frequency of the non-power supply drive compressor is increased due to load fluctuation, etc. Therefore, even when the amount of refrigeration oil discharged from the non-power source driven compressor increases, the amount of refrigeration oil in the non-power source driven compressor can be sufficiently maintained, and the operation reliability of the non-power source driven compressor is further increased. Can do.

  In the air conditioner of the present invention, even when the non-power-driven outdoor unit and the power-driven outdoor unit are used in combination, the refrigeration oil easily returns to the non-power-driven compressor incorporated in the non-power-driven outdoor unit, The operation reliability of the non-power source driven compressor can be improved without depleting the refrigerating machine oil of the non-power source driven compressor having a relatively large amount of refrigeration oil discharge.

FIG. 1 is a configuration diagram of a refrigeration cycle of an air conditioner according to Embodiment 1 of the present invention. FIG. 2 is an explanatory diagram showing an installation state of the air conditioner according to Embodiment 1 of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
A refrigeration cycle configuration of the air conditioner of the present embodiment is shown in FIG. The air conditioner of FIG. 1 includes a power-driven outdoor unit 100 equipped with a power-driven compressor 111 as an outdoor unit, and an engine-driven compressor (non-power-driven compressor) 211 driven by an engine that is a drive source other than electric power. This is a so-called multi-type air conditioner in which two indoor units are connected to a total of two engine drive outdoor units 200 mounted. The refrigeration cycle configuration is not limited to that shown in FIG. For example, three or more outdoor units and three or more indoor units can be connected in parallel.

  The power drive outdoor unit 100, the engine drive outdoor unit 200, and the indoor units 300 and 310 are connected by piping through which a refrigerant flows.

  In the power-driven outdoor unit 100, 111 is a power-driven compressor that is driven by electric power such as commercial power, and 111 a is a suction port of the power-driven compressor 111. An accumulator 112 is connected to a suction pipe of the power supply driven compressor 111 and supplies a gas refrigerant to the electrically driven compressor 111. An oil separator 113 is installed in the discharge pipe of the power supply driven compressor 111 and separates refrigeration oil contained in the discharge gas of the electric drive compressor 111. The refrigerating machine oil separated by the oil separator 113 is returned to the suction pipe of the power supply driven compressor 111 by the oil return pipe 113a. The oil return pipe 113a is connected to an oil return pipe on / off valve 113b, and the opening and closing of the oil return pipe on / off valve 113b controls the communication of the oil return pipe 113a.

  Reference numeral 114 denotes a four-way valve that switches between refrigeration cycles by cooling and heating, and 115 is an outdoor unit pressure reducing device that expands the refrigerant. Reference numeral 120 denotes an outdoor fan that supplies air around the outdoor unit 100 in which an electric drive compressor is mounted on the outdoor heat exchanger 130.

  In the engine driving outdoor unit 200, 210 is an engine using, for example, gas as a driving source, 211 is an engine driving compressor (non-power source driving compressor) that compresses refrigerant by obtaining driving force from the engine 210, and 211a This is a suction port of the engine driven compressor 211. An accumulator 212 is connected to a suction pipe of the engine driven compressor 211 and supplies a gas refrigerant to the engine driven compressor 211. Reference numeral 213 denotes an oil separator, which is installed in the discharge pipe of the engine-driven compressor 211 and separates refrigeration oil contained in the discharge gas of the engine-driven compressor 211. The refrigerating machine oil separated by the oil separator 213 is returned to the suction pipe of the engine-driven compressor 211 through the oil return pipe 213a. An oil return pipe on / off valve 213b is connected to the oil return pipe 213a, and the communication of the oil return pipe 213a is controlled by opening and closing the oil return pipe on / off valve 213b.

  Reference numeral 214 denotes a four-way valve that switches the refrigeration cycle between cooling and heating, and 215 is an outdoor unit pressure reducing device that expands the refrigerant. Reference numeral 216 denotes an engine exhaust heat exchanger that performs heat exchange between the high-temperature coolant used for cooling the engine 210 and the refrigerant, and is used during heating. Reference numeral 217 denotes a refrigerant flow rate adjustment valve for the engine exhaust heat heat exchanger that adjusts the flow rate of the refrigerant flowing into the engine exhaust heat heat exchanger 216. Reference numeral 220 denotes an outdoor fan that supplies air around the outdoor unit 200 in which the engine-driven compressor 211 is mounted on the outdoor heat exchanger 230.

  Here, the power supply driven compressor 111 and the engine driven compressor 211 are connected in parallel in the refrigeration cycle. Further, the position of the suction port 211 a of the engine driven compressor 211 is set to be lower than the position of the suction port 111 a of the power supply driven compressor 111. Specifically, as shown in FIG. 2, when the difference in height between the position of the suction port 111a of the power supply driven compressor 111 and the position of the suction port 211a of the engine driven compressor 211 is H, the current multi-type air conditioning The allowable height difference in the machine is preferably in the range of 0 <H <5 meters.

  In the present embodiment, when the suction port 211a position of the engine driven compressor 211 is set to be lower than the suction port 111a position of the power supply driven compressor 111, as shown in FIG. The power-driven compressor 111 is installed on the upper stage of the floor surface with a difference in height, and the engine-driven compressor 211 is installed on the lower stage of the floor surface. However, the present invention is not limited to this. For example, the power-driven compressor 111 may be installed on a floor surface having the same height via a spacer, or the bottom plate of the power-driven compressor 111 may be installed. The raised bottom may be installed so that the position of the suction port 211a of the engine driven compressor 211 is substantially lower than the position of the suction port 111a of the power source driven compressor 111.

  Further, the displacement volume of the engine driven compressor 211 is larger than the displacement volume of the power supply driven compressor 111. The lubricating oil for the power source driven compressor 111 and the engine driven compressor 211 is the same refrigerating machine oil. Further, the discharge and suction piping of the engine driven compressor 211 is thicker than the discharge and suction piping of the power supply driven compressor 111. Note that the flow resistance of the oil return pipe 213 a that flows the refrigerating machine oil separated by the oil separator 213 to the suction pipe of the power supply driven compressor 211 is the same as that of the refrigerating machine oil separated by the oil separator 113. The flow path resistance of the oil return pipe 113a flowing through the suction pipe is made smaller.

  In the indoor unit 300, 301 is an indoor heat exchanger, 302 is an indoor fan that supplies air around the indoor unit 300 to the indoor heat exchanger 301, and 303 is an indoor unit pressure reducing device that expands the refrigerant. Similarly, in the indoor unit 310, 311 is an indoor heat exchanger, 312 is an indoor blower fan that supplies air around the indoor unit 310 to the indoor heat exchanger 311, and 313 is an indoor unit pressure reducing device that expands the refrigerant.

  Next, operations of the electric drive outdoor unit 100, the non-electric drive outdoor unit 200, and the indoor units 300 and 310 will be described.

  During the cooling operation, the four-way valves 114 and 214 are set so that the refrigerant flows through the solid line (see FIG. 1). The high-temperature and high-pressure refrigerant compressed by the power supply driven compressor 111 and the engine driven compressor 211 flows into the oil separators 113 and 213, respectively. The high-purity gas refrigerant from which the refrigeration oil is separated by the oil separators 113 and 213 passes through the four-way valves 114 and 214 and enters the outdoor heat exchangers 130 and 230. In the outdoor heat exchangers 130 and 230, the gas refrigerants exchange heat with the outside air, dissipate heat, condense, become high-pressure liquid refrigerant, merge after passing through the outdoor unit decompression devices 115 and 215, 310.

  The refrigerating machine oil separated by the oil separator 113 closes the oil return pipe on / off valve 113b when the power supply driven compressor 111 is not driven, and the oil return pipe when the power supply driven compressor 111 is driven. By opening the on-off valve 113b, it is returned to the suction pipe of the power supply driven compressor 111. Similarly, the refrigeration oil separated by the oil separator 213 is closed when the engine-driven compressor 211 is not driven and the oil return pipe on / off valve 213b is closed, and when the engine-driven compressor 211 is driven, the oil return is returned. By opening the pipe opening / closing valve 213b, the pipe is returned to the suction pipe of the engine driven compressor 211.

  The high-pressure liquid refrigerant that has entered the indoor unit 300 is decompressed by the indoor unit decompression device 303, enters a gas-liquid two-phase state, and flows into the indoor heat exchanger 301. The refrigerant in the gas-liquid two-phase state evaporates after exchanging heat with the air in the space to be air-conditioned in the indoor heat exchanger 301 and then evaporates to flow out of the indoor unit 300.

  Also in the indoor unit 310, similarly to the indoor unit 300, first, the high-pressure liquid refrigerant is decompressed by the indoor unit decompression device 313, becomes a gas-liquid two-phase state, and flows into the indoor heat exchanger 311. In the indoor heat exchanger 311, the refrigerant in the gas-liquid two-phase state exchanges heat with the air in the space to be air-conditioned, absorbs heat, evaporates, and flows out from the indoor unit 310 as a gas refrigerant.

  When only the indoor unit 300 performs the cooling operation, the indoor unit pressure reducing device 313 is closed and the refrigerant is not supplied to the indoor heat exchanger 311 of the indoor unit 310. On the other hand, when only the indoor unit 310 performs the cooling operation, the indoor unit decompression device 303 is closed and the refrigerant is not supplied to the indoor heat exchanger 301 of the indoor unit 300.

  The gas refrigerant that has flowed out of the indoor units 300 and 310 merges, and then returns to the outdoor unit 100 on which the electrically driven compressor 111 is mounted and the outdoor unit 200 on which the engine driven compressor 211 is mounted. The gas refrigerant flowing into the outdoor unit 100 on which the electric drive compressor 111 is mounted returns to the electric drive compressor 111 through the four-way valve 114 and the accumulator 112. Similarly, the gas refrigerant that has flowed into the outdoor unit 200 on which the engine-driven compressor 211 is mounted returns to the engine-driven compressor 211 through the four-way valve 214 and the accumulator 212.

  The operation method of the power supply driven compressor 111 and the engine driven compressor 211 during the cooling operation is, for example, as follows.

  If the cooling load is smaller than the cooling capacity when the engine-driven compressor 211 is operated at the minimum operating frequency (the minimum cooling capacity of the engine-driven compressor 211), the engine-driven compressor 211 alone will cause intermittent operation. Only the power supply driven compressor 111 is operated.

  The cooling capacity when the cooling load is larger than the minimum cooling load of the engine driven compressor 211 and both the engine driven compressor 211 and the power source driven compressor 111 are operated at the minimum operating frequency (when both compressors are operated). If it is smaller than (minimum cooling capacity), one of the engine driven compressor 211 and the power source driven compressor 111, for example, the one with the lower operating cost or the lower energy consumption is selected for operation.

  When the cooling load is larger than the minimum cooling capacity during operation of both compressors, both the engine-driven compressor 211 and the power-driven compressor 111 are operated so that, for example, the operation cost or the energy consumption is minimized. To do. In this case, in determining the operating frequency of the engine driven compressor 211 and the power source driven compressor 111 for minimizing the operating cost or energy consumption, the operating frequency and operating cost of each compressor or the energy consumption Use the relationship.

  Actually, the ratio of the cooling load that the engine-driven compressor 211 has to the overall cooling load is the maximum cooling capacity when both compressors are operated at the maximum operating frequency (maximum cooling capacity when both compressors are operating). On the other hand, the ratio of the cooling capacity when only the engine driven compressor 211 is operated at the maximum operating frequency is about ± 15%.

  Next, at the time of heating operation, the four-way valves 114 and 214 are set so that the refrigerant flows along the dotted line (see FIG. 1). The high-temperature and high-pressure refrigerant compressed by the power supply driven compressor 111 and the engine driven compressor 211 flows into the oil separators 113 and 213, respectively. The high-purity gas refrigerant from which the refrigeration oil is separated by the oil separators 113 and 213 passes through the four-way valves 114 and 214, respectively, and is equipped with the outdoor unit 100 equipped with the electrically driven compressor 111 and the engine driven compressor 211. After exiting the outdoor unit 200, they join together and are supplied to the indoor units 300 and 310.

  The high-temperature and high-pressure gas refrigerant that has entered the indoor unit 300 flows into the indoor heat exchanger 301. In the indoor heat exchanger 301, the high-temperature and high-pressure gas refrigerant exchanges heat with the air in the air-conditioned space, dissipates the heat, condenses into a high-pressure liquid refrigerant, and passes through the indoor unit decompression device 303. , Out of the indoor unit 300.

  Also in the indoor unit 310, similarly to the indoor unit 300, first, the high-temperature and high-pressure gas refrigerant flows into the indoor heat exchanger 311. In the indoor heat exchanger 311, the high-temperature and high-pressure gas refrigerant exchanges heat with the air in the air-conditioned space, dissipates heat, condenses, becomes high-pressure liquid refrigerant, and passes through the indoor unit decompression device 313. , Flows out from the indoor unit 310.

  As in the case of cooling, when only the indoor unit 300 performs the heating operation, the indoor unit decompression device 313 is closed and the refrigerant is not supplied to the indoor heat exchanger 311 of the indoor unit 310. On the other hand, when only the indoor unit 310 performs the heating operation, the indoor unit pressure reducing device 303 is closed and the refrigerant is not supplied to the indoor heat exchanger 301 of the indoor unit 300.

  After the high-pressure liquid refrigerant flowing out of the indoor units 300 and 310 merges, the high-pressure liquid refrigerant returns to the outdoor unit 100 equipped with the electrically driven compressor 111 and the outdoor unit 200 equipped with the non-electrically driven compressor again. The high-pressure liquid refrigerant that has flowed into the outdoor unit 100 on which the electric drive compressor 111 is mounted is depressurized by the outdoor unit pressure reducing device 115, becomes a gas-liquid two-phase state, and flows into the outdoor heat exchanger 130. The refrigerant in the gas-liquid two-phase state evaporates after exchanging heat with the outside air in the outdoor heat exchanger 130 and then returns to the power supply driven compressor 111 through the four-way valve 114 and the accumulator 112. Similarly, the high-pressure liquid refrigerant that has flowed into the outdoor unit 200 on which the engine-driven compressor 211 is mounted is decompressed by the outdoor unit decompression device 215 and the engine exhaust heat heat exchanger refrigerant flow rate adjustment valve 217, and is in a gas-liquid two-phase state. And flows into the outdoor heat exchanger 230 and the engine exhaust heat exchanger 216, respectively. The refrigerant in a gas-liquid two-phase state absorbs heat by exchanging heat with the outside air in the outdoor heat exchanger 230 and with the high-temperature cooling water used for cooling the engine 210 in the engine exhaust heat exchanger 216 and then evaporates. , Through the four-way valve 214 and the accumulator 212, and return to the engine-driven compressor 211.

  The operation method of the power supply driven compressor 111 and the engine driven compressor 211 during the heating operation is, for example, as follows.

  If the heating load is smaller than the heating capacity when the engine-driven compressor 211 is operated at the minimum operating frequency (the minimum heating capacity of the engine-driven compressor 211), the engine-driven compressor 211 alone will cause intermittent operation. Only the power supply driven compressor 111 is operated.

  Heating capacity when the heating load is larger than the minimum heating load of the engine-driven compressor 211 and both the engine-driven compressor 211 and the power-driven compressor 111 are operated at the minimum operating frequency (during both compressor operations) If it is smaller than (minimum heating capacity), one of the engine driven compressor 211 and the power source driven compressor 111, for example, the one with lower operating cost or lower energy consumption is selected for operation.

  When the heating load is larger than the minimum heating capacity during the operation of both compressors, both the engine-driven compressor 211 and the power-driven compressor 111 are operated so that, for example, the operating cost or energy consumption is minimized. To do. In this case, in determining the operating frequency of the engine driven compressor 211 and the power source driven compressor 111 for minimizing the operating cost or energy consumption, the operating frequency and operating cost of each compressor or the energy consumption Use the relationship.

  Actually, the ratio of the heating load that the engine-driven compressor 211 has to the overall heating load is the maximum heating capacity when both compressors are operated at the maximum operating frequency (maximum heating capacity when operating both compressors). On the other hand, the ratio of the heating capacity when only the engine-driven compressor 211 is operated at the maximum operating frequency is about ± 15%.

  However, during the heating operation, the frost formation state of the outdoor heat exchangers 130 and 230 is constantly monitored. If there is a risk of frost formation, each compression is performed so that the operation cost or the energy consumption is minimized. Even if the operating frequencies of the machines 111 and 211 are set, control is performed to increase the operating frequency of the engine-driven compressor 211 and to decrease the operating frequency of the power supply-driven compressor 111.

  When the operating frequency of the engine-driven compressor 211 is increased, the amount of exhaust heat of the engine 210 is increased, and the amount of heat of cooling water supplied to the engine exhaust heat heat exchanger 216 is also increased. That is, more refrigerant can be evaporated in the engine exhaust heat exchanger 216, and the amount of refrigerant flowing to the outdoor heat exchangers 130 and 230 is reduced, thereby reducing the risk of frost formation.

  As is clear from the above description, in this embodiment, since the position of the engine driven compressor 211 is below the power supply driven compressor 111, the refrigeration oil having a higher specific gravity than the refrigerant is driven by the engine. It becomes easy to return to the compressor 211, and the operation reliability of the engine-driven compressor 211 can be improved without depleting the refrigeration oil of the engine-driven compressor 211.

  In addition, the flow resistance of the oil return pipe 213 a that flows the refrigerating machine oil separated by the oil separator 213 to the suction pipe of the power supply driven compressor 211 is the same as that of the refrigerating machine oil separated by the oil separator 113. The flow path resistance of the oil return pipe 113a flowing through the suction pipe is made smaller. As a result, the amount of refrigerating machine oil returning from the oil separator 213 installed in the discharge pipe of the engine-driven compressor 211 to the engine-driven compressor 211 is from the oil separator 113 installed in the discharge pipe of the power supply-driven compressor 111. The amount of refrigeration oil returning to the power supply driven compressor 111 is increased, and the operation reliability of the engine driven compressor 211 can be further increased.

  Further, the displacement volume of the engine driven compressor 211 is larger than the displacement volume of the power supply driven compressor 111. As a result, only the efficient power-driven compressor 111 is operated at the time of a low load that can only be intermittently operated by the engine-driven compressor 211 alone, and the most efficient load sharing between the middle and the high load. It is possible to operate with distribution, and the operation efficiency of the outdoor unit as a whole can be increased.

  Further, the discharge and suction piping of the engine driven compressor 211 is thicker than the discharge and suction piping of the power supply driven compressor 111. In this way, an increase in pressure loss in the discharge and suction pipes on the engine-driven compressor side where the refrigerant flow is large is suppressed, and the return amount of the refrigeration oil from the refrigeration cycle to the engine-driven compressor 211 is reduced by the power-driven compressor. The operating reliability of the engine driven compressor 211 can be improved without depleting the refrigeration oil of the engine driven compressor 211.

  Since the engine driving outdoor unit 200 and the electric driving outdoor unit 100 have independent structures, for example, the electric driving outdoor unit 100 is newly added to a system including the engine driving outdoor unit 200 that has already been installed. In the case of adding an additional unit, the refrigerant piping parts of the existing equipment can be used as they are, the construction period can be shortened, and the cost of adding an outdoor unit can be suppressed. Similarly, when a new non-electrically driven outdoor unit 200 is newly added to the system including the electric driven outdoor unit 100 that has already been installed, the refrigerant piping parts and the like of the existing equipment can be used as they are, and the construction period can be reduced. This shortens the cost and increases the cost of adding outdoor units.

  The present invention is a so-called hybrid air conditioner that uses a combination of an engine-driven compressor and a power-driven compressor, so that a sufficient amount of refrigeration oil can be returned to the compressor, and the operation reliability of the compressor can be ensured. Can be improved, and can be suitably used as a highly reliable air conditioner.

DESCRIPTION OF SYMBOLS 100 Electric drive outdoor unit 111 Electric drive compressor 111a Inlet 112 Accumulator 113 Oil separator 113a Oil return pipe 113b Oil return pipe open / close valve 114 Four-way valve 115 Outdoor unit decompression device 120 Outdoor fan 130 Outdoor heat exchanger 200 Outside engine drive room Unit 210 Engine 211 Engine-driven compressor 211a Suction port 212 Accumulator 213 Oil separator 213a Oil return pipe 213b Oil return pipe on-off valve 214 Four-way valve 215 Outdoor unit pressure reducing device 216 Engine exhaust heat exchanger 217 Refrigerant for engine exhaust heat exchanger Flow control valve 220 Outdoor blower fan 230 Outdoor heat exchanger 300 Indoor unit 301 Indoor heat exchanger 302 Indoor blower fan 303 Indoor unit decompression device 310 Indoor unit 311 Indoor heat exchanger 12 indoor blower fan 313 indoor unit decompressor

Claims (2)

A power-driven outdoor unit equipped with a power-driven compressor driven by electric power and a non-power-driven outdoor unit equipped with a non-power-driven compressor driven by a driving source other than electric power extend from at least one indoor unit. An air conditioner connected in parallel to the inter-unit piping ,
In the installed state of the air conditioner, the so inlet position of non-power driven compressor is vertically lower side than the inlet position of the power driven compressor, the said power supply driving the outdoor unit non-power driven an air conditioner outdoor unit is installed.   A non-power-driven compressor oil separator that separates refrigerating machine oil from the refrigerant discharged from the non-power-driven compressor, and a power-driven compressor oil separator that separates refrigerating machine oil from the refrigerant discharged from the power-driven compressor, Flow resistance of a pipe for flowing refrigeration oil from the non-power-driven compressor oil separator to the suction pipe of the non-power-driven compressor, and refrigeration oil from the power-driven compressor oil separator to the suction pipe of the power-driven compressor The air conditioner according to claim 1, wherein the air conditioner is smaller than the flow path resistance of the flowing pipe.

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