Outdoor unit of air conditioner, and air conditioner

Abstract

To Provide an outdoor unit of an air conditioner and an air conditioner in which connections between a plurality of outdoor heat exchangers, the discharge side of a compressor, and the suction side of a compressor can be switched and which have excellent piping installation routes. The present invention includes: a compressor (2) that compresses refrigerant; a main heat exchanger (31a) that exchanges heat between the refrigerant and outside air; a first switching valve (12A) that sends the refrigerant from the compressor (2) to the main heat exchanger (31a) to cause the main heat exchanger (31a) to function as a condenser; an auxiliary heat exchanger (31b) that exchanges heat between the refrigerant and outside air; a second switching valve (12B) that sends the refrigerant from the compressor (2) to the auxiliary heat exchanger (31b) to cause the auxiliary heat exchanger (31b) to function as a condenser; and a third switching valve (12C) that is capable of blocking the flow of refrigerant from the compressor (2) to indoor heat exchangers (21A, 21B, ...) of all indoor units (6A, 6B, ...) to cause the main heat exchanger (31a) and the auxiliary heat exchanger (31b) to function as condensers, and capable of sending the refrigerant from the compressor (2) to the indoor heat exchanger (21A, 21B, ...) of at least one indoor unit (6A, 6B, ...) to cause the at least one indoor heat exchanger (21A) to function as a condenser. The first switching valve (12A) is closer to an end surface (101) of the main heat exchanger (31a) than the third switching valve (12C) is, and the second switching valve (12B) is closer to the end surface (101) of the main heat exchanger (31a) than the first switching valve (12A) is.

Description

Technical Field

[0001] Embodiments of the present invention relate to an outdoor unit of an air conditioner, and an air conditioner.Background Art

[0002] An air conditioner provided with an outdoor unit, a plurality of indoor units, a plurality of switching units, a first connecting pipe, a second connecting pipe, and a third connecting pipe is known. The outdoor unit includes an outdoor heat exchanger and a compressor. The outdoor unit includes an outdoor first pipe that connects the outdoor heat exchanger and the first connecting pipe, an outdoor second pipe that connects the compressor and the second connecting pipe, and an outdoor third pipe that connects the compressor and the third connecting pipe. Each indoor unit includes an indoor heat exchanger.

[0003] Each switching unit includes an indoor first pipe that connects the indoor heat exchanger and the first connecting pipe, an indoor second pipe that connects the indoor heat exchanger and the second connecting pipe, an indoor third pipe that connects the indoor heat exchanger and the third connecting pipe, and an indoor third pipe valve provided in the indoor third pipe. Each indoor third pipe valve switches a connection state of the three pipes of the outdoor unit and the two pipes of each indoor unit.

[0004] This conventional air conditioner can not only execute a heating operation in all of the indoor units or execute a cooling operation in all of the indoor units but also execute the heating operation in some indoor units and execute the cooling operation in the remaining indoor units.Prior Art DocumentsPatent Documents

[0005] [Patent Document 1] JP 2017-180882 ASummary of the InventionProblems to be Solved by the Invention

[0006] Conventional air conditioners have room for improvement in pipe installation routes in an outdoor unit.

[0007] Therefore, an object of the present invention is to provide an outdoor unit of an air conditioner, or an air conditioner in which connection of a plurality of outdoor heat exchangers, a discharge side of a compressor, and a suction side of the compressor can be switched and which has excellent pipe installation routes.

[0008] To achieve the above object, an aspect of the present invention provides an outdoor unit of an air conditioner, the outdoor unit including: a compressor that compresses a refrigerant; a first outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; a first switching valve that connects a discharge side of the compressor to the first outdoor heat exchanger to cause the first outdoor heat exchanger to function as a condenser, or connects a suction side of the compressor to the first outdoor heat exchanger to cause the first outdoor heat exchanger to function as an evaporator; a second outdoor heat exchanger that exchanges heat between the refrigerant and the outdoor air; a second switching valve that connects the discharge side of the compressor to the second outdoor heat exchanger to cause the second outdoor heat exchanger to function as a condenser, or connects the suction side of the compressor to the second outdoor heat exchanger to cause the second outdoor heat exchanger to function as an evaporator; and a third switching valve that shuts off connection of the discharge side of the compressor and indoor heat exchangers of all of indoor units to cause the first outdoor heat exchanger and the second outdoor heat exchanger to function as condensers, or connects the discharge side of the compressor to the indoor heat exchanger of at least one of the indoor units to cause the indoor heat exchanger of the at least one of the indoor units to function as a condenser. The first switching valve is closer to the first heat exchanger than the third switching valve is. The second switching valve is closer to the first heat exchanger than the first switching valve is.

[0009] It may be desired that the first switching valve, the second switching valve, and the third switching valve are disposed on an outer side of a projection region in a normal direction of an end face of the first heat exchanger.

[0010] It may be desired that the first outdoor heat exchanger and the second outdoor heat exchanger are integrated and the end face of the first outdoor heat exchanger and an end face of the second outdoor heat exchanger form one continuous plane.

[0011] It may be desired that the first switching valve, the second switching valve, and the third switching valve are four-way valves, and include a first connecting port connectable to a condenser and a second connecting port connectable to an evaporator, and either one of the first connecting port and the second connecting port is closed.

[0012] It may be further desired that a housing that houses the compressor, the first outdoor heat exchanger, the second outdoor heat exchanger, the first switching valve, the second switching valve, and the third switching valve. The end face of the first outdoor heat exchanger and the end face of the second outdoor heat exchanger face a horizontal direction of the housing, and The first switching valve, the second switching valve, and the third switching valve each include a valve body, a valve box that houses the valve body movably in the horizontal direction, a third connecting port that hangs down below the valve box and is connected to the discharge side of the compressor, and a fourth connecting port that rises above the valve box and is connected to the suction side of the compressor.

[0013] It may be desired that the housing has a detachable side face, and the first switching valve, the second switching valve, and the third switching valve each include a pilot solenoid valve facing an inner surface of the side face.

[0014] It may be further desired that an accumulator connected to the suction side of the compressor. The first heat exchanger is disposed above the second heat exchanger, and the first switching valve, the second switching valve, and the third switching valve are disposed above the accumulator.

[0015] To achieve the above object, an aspect of the present invention provides an air conditioner including: the outdoor unit; a plurality of the indoor units; and a plurality of switching units that switch a flowing direction of the refrigerant flowing to the corresponding indoor units. The outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger. The indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger. The flowing direction of the refrigerant flowing to the plurality of indoor units is caused to be different from each other to mix the indoor units that perform a cooling operation and the indoor units that perform a heating operation.

[0016] To achieve the above object, an aspect of the present invention provides an air conditioner including: the outdoor unit; and a plurality of the indoor units. The outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger. The indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger. One of branches of the third switching valve is closed so as to cause the refrigerant to be sucked to the compressor through the third switching valve during a cooling operation and to cause the refrigerant to be sent to the plurality of indoor units through the third switching valve during a heating operation.

[0017] To achieve the above object, an aspect of the present invention provides an air conditioner including: the outdoor unit; and a plurality of the indoor units. The outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger. The indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger. A flowing direction of the refrigerant flowing to the plurality of indoor units is caused to be different from each other to mix the indoor units that perform a cooling operation and the indoor units that perform a heating operation when a plurality of switching units that switch the flowing direction of the refrigerant flowing to the corresponding indoor units are provided. One of branches of the third switching valve is closed so as to cause the refrigerant to be sucked to the compressor through the third switching valve during the cooling operation and to cause the refrigerant to be sent to the plurality of indoor units through the third switching valve during the heating operation, the flowing direction of the refrigerant flowing to the plurality of indoor units is unified, and all of the indoor units are caused to perform the cooling operation or the heating operation when the plurality of switching units are not provided.EFFECTS OF INVENTION

[0018] The present invention can provide an outdoor unit of an air conditioner, or an air conditioner in which connection of a plurality of outdoor heat exchangers, a discharge side of a compressor, and a suction side of the compressor can be switched and which has excellent pipe installation routes.BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 is a block diagram of the air conditioner according to the embodiment of the present invention. Fig. 2 is a diagram illustrating a first example of the flow of the refrigerant in a mixed cooling operation state of the air conditioner according to the present embodiment. Fig. 3 is a diagram illustrating a second example of the flow of the refrigerant in the mixed cooling operation state of the air conditioner according to the present embodiment. Fig. 4 is a diagram illustrating an example of the flow of the refrigerant in a mixed heating operation state of the air conditioner according to the present embodiment. Fig. 5 is an exploded perspective view of a first example of the outdoor unit according to the embodiment of the present invention. Fig. 6 is a front view of a first example of the outdoor unit according to the embodiment of the present invention. Fig. 7 is a schematic front view of the first example of the outdoor unit according to the embodiment of the present invention. Fig. 8 is a plan view of the first example of the outdoor unit according to the embodiment of the present invention. Fig. 9 is a perspective view of the three switching valves of the outdoor unit according to the embodiment of the present invention. Fig. 10 is a schematic front view of a first comparative example of the outdoor unit. Fig. 11 is a schematic front view of a second comparative example of the outdoor unit. Fig. 12 is a front view of the second example of the outdoor unit according to the embodiment of the present invention. Fig. 13 is a schematic front view of the second example of the outdoor unit according to the embodiment of the present invention. Fig. 14 is a plan view of the second example of the outdoor unit according to the embodiment of the present invention. Fig. 15 is a perspective view of the three switching valves of the outdoor unit according to the embodiment of the present invention. Fig. 16 is a schematic front view of a third comparative example of the outdoor unit. Fig. 17 is a schematic front view of a fourth comparative example of the outdoor unit. Fig. 18 is a block diagram of a second form of the air conditioner according to the embodiment of the present invention. Description of Embodiments

[0020] An embodiment of an outdoor unit of an air conditioner according to the present invention and an embodiment of the air conditioner according to the present invention will be described with reference to Fig. 1 to Fig. 18. Note that same or corresponding configurations are denoted by same reference signs in a plurality of drawings.

[0021] Fig. 1 is a block diagram of the air conditioner according to the embodiment of the present invention.

[0022] As illustrated in Fig. 1, an air conditioner 1 according to the present invention is a heat-recovery multi-type air conditioner. The air conditioner 1 includes at least one outdoor unit 5 provided with a compressor 2 that compresses a refrigerant, a plurality of indoor units 6A, 6B,..., and a plurality of switching units 7A, 7B,... capable of switching a flowing direction of the refrigerant flowing to the indoor units 6A, 6B,.... In addition, the air conditioner 1 includes refrigerant piping 8 that successively connects the outdoor unit 5, the plurality of switching units 7A, 7B,..., and the plurality of indoor units 6A, 6B,... to circulate the refrigerant.

[0023] The air conditioner 1 circulates the refrigerant between the outdoor unit 5 and the plurality of indoor units 6A, 6B,..., and performs a full cooling operation of causing the outdoor unit 5 to function as a condenser and causing all of the indoor units 6A, 6B,... to function as evaporators, and a full heating operation of causing the outdoor unit 5 to function as an evaporator and causing all of the indoor units 6A, 6B,... to function as condensers.

[0024] Further, the air conditioner 1 can mix the indoor units 6A, 6B,... that perform a cooling operation and the indoor units 6A, 6B,... that perform a heating operation by making the flowing direction of the refrigerant flowing to the plurality of indoor units 6A, 6B,... be different from each other. The air conditioner 1 performs a mixed cooling operation of causing the outdoor unit 5 to function as a condenser, causing some indoor units 6A and 6B to function as evaporators, and causing the remaining indoor unit 6C to function as a condenser, and a mixed heating operation of causing the outdoor unit 5 to function as an evaporator, causing some indoor units 6A and 6B to function as condensers, and causing the remaining indoor unit 6C to function as an evaporator. The mixed cooling operation is an operation mainly for cooling, in which the cooling operation is performed in a large number of the indoor units 6A and 6B and the heating operation is performed in a small number of the indoor unit 6C. The mixed heating operation is an operation mainly for heating, in which the heating operation is performed in a large number of the indoor units 6A and 6B and the cooling operation is performed in a small number of the indoor unit 6C.

[0025] The outdoor unit 5 includes the compressor 2 that compresses and discharges the sucked refrigerant, an oil separator 11 provided on a discharge side of the compressor 2, at least three switching valves 12A, 12B, and 12C that switch a circulation route of the refrigerant circulated between the outdoor unit 5 and the indoor units 6A, 6B,..., two outdoor heat exchangers 13 that exchange heat between the refrigerant and outdoor air, two outdoor expansion valves 15 that reduce a pressure of the refrigerant flowing from the indoor units 6A, 6B,... to the respective outdoor heat exchangers 13, and an accumulator 16 provided on a suction side of the compressor 2. In addition, the outdoor unit 5 includes an outdoor fan 17 that causes the outdoor air heat-exchanged in the two outdoor heat exchangers 13 to flow. Further, the outdoor unit 5 includes an inverter circuit 18 that controls an operating frequency of the compressor 2, and a control unit 19 that controls the inverter circuit 18.

[0026] The plurality of indoor units 6A, 6B,... all have a similar configuration. Hereinafter, one representative indoor unit 6A will be described. The indoor unit 6A includes an indoor heat exchanger 21A that exchanges heat between the refrigerant and indoor air, and an indoor expansion valve 22A that reduces the pressure of the refrigerant flowing from the outdoor unit 5 to the indoor heat exchanger 21A. In addition, the indoor unit 6A includes an indoor fan 23A that causes the indoor air heat-exchanged in the indoor heat exchanger 21A to flow. Further, the indoor unit 6A includes an indoor control unit (not illustrated).

[0027] The plurality of switching units 7A, 7B,... all have a similar configuration. Hereinafter, one representative switching unit 7A will be described. The switching unit 7A includes a discharge gas pipe shutoff valve 25A that allows or shuts off flow of the refrigerant from the compressor 2 to the indoor heat exchanger 21A, and a suction gas pipe shutoff valve 26A that allows or shuts off the flow of the refrigerant from the indoor heat exchanger 21A to the compressor 2. The indoor heat exchanger 21A of the indoor unit 6A functions as an evaporator by closing the discharge gas pipe shutoff valve 25A and opening the suction gas pipe shutoff valve 26A. The indoor heat exchanger 21A functions as a condenser by opening the discharge gas pipe shutoff valve 25A and closing the suction gas pipe shutoff valve 26A.

[0028] The compressor 2 is housed in the outdoor unit 5. The compressor 2 changes the operating frequency by output of the inverter circuit 18. The air conditioner 1 may include the plurality of compressors 2. In that case, the number of the inverter circuits 18 is preferably same as the number of the compressors 2 and each inverter circuit 18 individually controls the operating frequency of the corresponding compressor 2. The compressor 2 changes the operating frequency by known inverter control. The compressor 2 may be operated at a fixed operating frequency.

[0029] The compressor 2 includes a sealed case, a compression mechanism that compresses the refrigerant, and an electric motor that drives the compression mechanism. The sealed case houses the compression mechanism and the electric motor. The sealed case stores refrigerator oil that lubricates the compression mechanism. The discharge side of the compressor 2 is connected to the oil separator 11. The suction side of the compressor 2 is connected to the accumulator 16. Further, the compressor 2 includes an accumulator 2a of a capacity smaller than that of the accumulator 16. This small-capacity accumulator 2a is a gas-liquid separator that separates a gas refrigerant and a liquid refrigerant and sends the gas refrigerant to the compressor 2. The small-capacity accumulator 2a is also referred to as a suction muffler or a suction cup, and is provided between the suction side of the compressor 2 and the accumulator 16 of a large capacity.

[0030] The oil separator 11 separates the gas refrigerant and the refrigerator oil discharged from the compressor 2. The refrigerator oil separated in the oil separator 11 is returned to the compressor 2 through a return pipe (not illustrated). The oil separator 11 is a centrifugal separator for example.

[0031] Each outdoor heat exchanger 13 and each indoor heat exchanger 21A are fin-and-tube type heat exchangers for example. Each outdoor heat exchanger 13 and each indoor heat exchanger 21A include a plurality of paths 28 through which the refrigerant flows, a header 29 that distributes the refrigerant to the plurality of paths 28 or merges the refrigerant distributed to the plurality of paths 28, and a plurality of fins that extend orthogonally to the plurality of paths 28.

[0032] The two outdoor heat exchangers 13 include a main heat exchanger 31a as a first outdoor heat exchanger, and an auxiliary heat exchanger 31b as a second outdoor heat exchanger connected in parallel with the main heat exchanger 31a. The main heat exchanger 31a is connected to the first switching valve 12A. The auxiliary heat exchanger 31b is connected to the second switching valve 12B.

[0033] The switching valves 12A, 12B, and 12C are electrically connected to the control unit 19 by using a signal line (not illustrated), respectively. The air conditioner 1 switches the cooling operation (the flow of the refrigerant indicated with solid line arrows in Fig. 1) and the heating operation (the flow of the refrigerant indicated with broken line arrows in Fig. 1) by switching the flowing direction of the refrigerant with the three switching valves 12A, 12B, and 12C.

[0034] The first switching valve 12A connects the discharge side of the compressor 2 to the main heat exchanger 31a to cause the main heat exchanger 31a to function as a condenser. In addition, the first switching valve 12A connects the suction side of the compressor 2 to the main heat exchanger 31a to cause the main heat exchanger 31a to function as an evaporator.

[0035] The second switching valve 12B connects the discharge side of the compressor 2 to the auxiliary heat exchanger 31b to cause the auxiliary heat exchanger 31b to function as a condenser. In addition, the second switching valve 12B connects the suction side of the compressor 2 to the auxiliary heat exchanger 31b to cause the auxiliary heat exchanger 31b to function as an evaporator.

[0036] The third switching valve 12C shuts off connection of the discharge side of the compressor 2 and indoor heat exchangers 21A, 21B,... of all of the indoor units 6A, 6B,... to cause the two outdoor heat exchangers 13 to function as condensers, or connects the discharge side of the compressor 2 to the indoor heat exchangers 21A, 21B,... of at least one of the indoor units 6A, 6B,... to cause the indoor heat exchangers 21A, 21B,... of at least one of the indoor units 6A, 6B,... to function as condensers.

[0037] The two outdoor expansion valves 15 includes a first outdoor expansion valve 15a connected to the main heat exchanger 31a and a second outdoor expansion valve 15b connected to the auxiliary heat exchanger 31b.

[0038] The main heat exchanger 31a is disposed between the first switching valve 12A and the first outdoor expansion valve 15a, and the auxiliary heat exchanger 31b is disposed between the second switching valve 12B and the second outdoor expansion valve 15b. That is, the refrigerant is distributed on an intel side of the main heat exchanger 31a and the auxiliary heat exchanger 31b, and is merged on an outlet side of the main heat exchanger 31a and the auxiliary heat exchanger 31b.

[0039] The outdoor fan 17 and the indoor fan 23A are, for example, axial fans. The outdoor fan 17 accelerates heat exchange of the outdoor air and the refrigerant flowing to the two outdoor heat exchangers 13. The indoor fan 23A accelerates heat exchange of the indoor air and the refrigerant flowing to the indoor heat exchanger 21A.

[0040] The two outdoor expansion valves 15 and the indoor expansion valve 22A are, for example, electronic expansion valves (Pulse Motor Valves, PMV) for which a valve opening degree is adjustable. The electronic expansion valve includes a valve box provided with a through-hole, and a needle as a valve body movable forward and backward to / from the through-hole. When the needle closes the through-hole, the electronic expansion valve shuts off the flow of the refrigerant. At that time, the electronic expansion valve is in a closed state and the valve opening degree of the electronic expansion valve is smallest. When the needle is most separated from the through-hole, the electronic expansion valve maximizes a flow rate of the refrigerant. At that time, the electronic expansion valve is in a fully open state, and the valve opening degree of the electronic expansion valve is largest.

[0041] The accumulator 16 is a gas-liquid separator that separates the gas refrigerant and the liquid refrigerant and sends the gas refrigerant to the compressor 2.

[0042] The discharge gas pipe shutoff valve 25A and the suction gas pipe shutoff valve 26A may be a stop valve or may be an electronic expansion valve for which the opening degree is adjustable. The discharge gas pipe shutoff valve 25A allows or shuts off the flow of the refrigerant that is discharged from the compressor 2 and discharged to the indoor heat exchanger 21A through the third switching valve 12C. The suction gas pipe shutoff valve 26A allows or shuts off the flow of the refrigerant that is sucked from the indoor heat exchanger 21A to the compressor 2.

[0043] The refrigerant piping 8 includes three connecting pipes 35, 36, and 37 that connect the outdoor unit 5 and the plurality of switching units 7A, 7B,... to cause the refrigerant to move back and forth, and two connecting pipes 38A and 39A that connect the switching unit 7A and the indoor unit 6A to cause the refrigerant to move back and forth. The connecting pipes 35, 36, and 37 are branch pipes that connect the one outdoor unit 5 and the plurality of switching units 7A, 7B, ....

[0044] The outdoor unit 5 includes a pipe connecting port 41 that connects the connecting pipe 35, a pipe connecting port 42 that connects the connecting pipe 36, and a pipe connecting port 43 that connects the connecting pipe 37.

[0045] The switching unit 7A includes a pipe connecting port 45A that connects the connecting pipe 35, a pipe connecting port 46A that connects the connecting pipe 36, and a pipe connecting port 47A that connects the connecting pipe 37.

[0046] The connecting pipe 35 is the branch pipe that connects the one pipe connecting port 41 and a plurality of pipe connecting ports 45A, 45B,.... The connecting pipe 36 is the branch pipe that connects the one pipe connecting port 42 and a plurality of pipe connecting ports 46A, 46B,.... The connecting pipe 37 is the branch pipe that connects the one pipe connecting port 43 and a plurality of pipe connecting ports 47A, 47B,....

[0047] In addition, the switching unit 7A includes a pipe connecting port 48A that connects the connecting pipe 38A and a pipe connecting port 49A that connects the connecting pipe 39A.

[0048] The indoor unit 6A includes a pipe connecting port 51A that connects the connecting pipe 38A and a pipe connecting port 52A that connects the connecting pipe 39A.

[0049] The pipe connecting ports 41, 42, and 43 of the outdoor unit 5, the pipe connecting ports 45A, 45B, 45C, 46A, 46B, 46C, 47A, 47B, and 47C on the side of the outdoor unit 5 of the respective switching units 7A, 7B,..., the pipe connecting ports 48A, 48B, 48C, 49A, 49B, and 49C on the side of the indoor units 6A, 6B,... of the respective switching units 7A, 7B,..., and the pipe connecting ports 51A, 51B, 51C, 52A, 52B, and 52C of the indoor units 6A, 6B,... are packed valves (back seating type valves) having a structure that prevents the refrigerant from being discharged to the atmosphere.

[0050] The refrigerant piping 8 successively connects the compressor 2, the oil separator 11, the three switching valves 12A, 12B, and 12C, the two outdoor heat exchangers 13, the two outdoor expansion valves 15, a plurality of indoor expansion valves 22A, 22B,..., the plurality of indoor heat exchangers 21A, 21B,..., a plurality of discharge gas pipe shutoff valves 25A, 25B,..., a plurality of suction gas pipe shutoff valves 26A, 26B,..., and the accumulator 16.

[0051] The refrigerant piping 8 inside the outdoor unit 5 includes a first pipe 61 that connects the discharge side of the compressor 2 and the oil separator 11, a second branch pipe 62 that connects the oil separator 11 and the three switching valves 12A, 12B, and 12C, a third pipe 63 that connects the first switching valve 12A and one of the outdoor heat exchangers 13, a fourth pipe 64 that connects the second switching valve 12B and the other outdoor heat exchanger 13, a fifth pipe 65 that connects one of the outdoor heat exchangers 13 and one of the outdoor expansion valves 15, a sixth pipe 66 that connects the other outdoor heat exchanger 13 and the other outdoor expansion valve 15, and a seventh branch pipe 67 that connects the two outdoor expansion valves 15 and the pipe connecting port 41.

[0052] The first pipe 61 and the second branch pipe 62 are refrigerant feed pipes connected to the discharge side of the compressor 2 regardless of a switching state of the three switching valves 12A, 12B, and 12C.

[0053] Further, the refrigerant piping 8 inside the outdoor unit 5 includes an eighth branch pipe 68 that connects the pipe connecting port 43, the three switching valves 12A, 12B, and 12C, and the accumulator 16, a ninth pipe 69 that connects the accumulator 16 and the suction side of the compressor 2, and a 10th pipe 70 that connects the third switching valve 12C and the pipe connecting port 42.

[0054] The eighth branch pipe 68 and the ninth pipe 69 are refrigerant return pipes connected to the suction side of the compressor 2 regardless of the switching state of the three switching valves 12A, 12B, and 12C.

[0055] The refrigerant piping 8 inside each switching unit 7A includes an 11th pipe 71A that connects the pipe connecting port 45A and the pipe connecting port 48A, a 12th branch pipe 72A that connects the discharge gas pipe shutoff valve 25A, the suction gas pipe shutoff valve 26A, and the pipe connecting port 49A, a 13th pipe 73A that connects the pipe connecting port 46A and the discharge gas pipe shutoff valve 25A, and a 14th pipe 74A that connects the pipe connecting port 47A and the suction gas pipe shutoff valve 26A.

[0056] The refrigerant piping 8 inside each indoor unit 6A includes a 15th pipe 75A that connects the pipe connecting port 51A and the indoor expansion valve 22A, a 16th pipe 76A that connects the indoor expansion valve 22A and the indoor heat exchanger 21A, and a 17th pipe 77A that connects the indoor heat exchanger 21A and the pipe connecting port 52A.

[0057] The inverter circuit 18 rectifies AC power supplied from a commercial AC power source, converts rectified DC power to a frequency according to a command of the control unit 19, and outputs it to the electric motor of the compressor 2. That is, the inverter circuit 18 can control the operating frequency of the compressor 2.

[0058] The control unit 19 controls the inverter circuit 18 to control the operating frequency of the compressor 2. In addition, the control unit 19 controls the three switching valves 12A, 12B, and 12C, the plurality of discharge gas pipe shutoff valves 25A, 25B,..., and the plurality of suction gas pipe shutoff valves 26A, 26B,... based on an operation input to a remote controller (not illustrated), and switches the full cooling operation (the flow of the refrigerant indicated with the solid line arrows in Fig. 1) and the full heating operation (the flow of the refrigerant indicated with the broken line arrows in Fig. 1). Note that the control unit 19 may be distributed and disposed in the outdoor unit 5 and the indoor units 6A, 6B,.... For example, the control unit 19 provided on the outdoor unit 5 controls the inverter circuit 18 and the three switching valves 12A, 12B, and 12C, and the control unit 19 provided on the respective indoor units 6A, 6B,... controls the corresponding discharge gas pipe shutoff valves 25A, 25B,... and suction gas pipe shutoff valves 26A, 26B,....

[0059] Here, an operation state of the air conditioner 1 will be described. In any operation, the compressor 2 discharges the refrigerant to the first pipe 61 and the second branch pipe 62 and sucks the refrigerant from the eighth branch pipe 68 and the ninth pipe 69.

[0060] The flowing direction of the refrigerant in the full cooling operation is indicated with the solid line arrows in Fig. 1. The first switching valve 12A and the second switching valve 12B are switched so as to connect the discharge side of the compressor 2 to the respective outdoor heat exchangers 13 (31a and 31b). That is, the second branch pipe 62 is connected to the third pipe 63 and the fourth pipe 64. The third switching valve 12C is switched so as to shut off the connection of the discharge side of the compressor 2 and the 10th pipe 70. The discharge gas pipe shutoff valves 25A, 25B,... are fully closed. The suction gas pipe shutoff valves 26A, 26B,... are fully opened and the indoor heat exchangers 21A, 21B,... are connected to the suction side of the compressor 2.

[0061] The compressor 2 discharges a high-temperature and high-pressure gas refrigerant to the first pipe 61. The high-temperature and high-pressure gas refrigerant flows from the first pipe 61 into the oil separator 11. The oil separator 11 separates the refrigerator oil from the high-temperature and high-pressure gas refrigerant. The gas refrigerant from which the oil is separated flows out from the oil separator 11 and reaches the two outdoor heat exchangers 13 (31a and 31b) through the first switching valve 12A and the second switching valve 12B. The two outdoor heat exchangers 13 (31a and 31b) exchange the heat between the outdoor air and the gas refrigerant to condense the refrigerant, and causes the liquid refrigerant to flow out. The liquid refrigerant flowing out from the two outdoor heat exchangers 13 (31a and 31b) reaches the respective indoor heat exchangers 21A, 21B,... through the two outdoor expansion valves 15 (15a and 15b), the 11th pipes 71A, 71B,... inside the respective switching units 7A, 7B,..., and the respective indoor expansion valves 22A, 22B,.... The two outdoor expansion valves 15 (15a and 15b) adjust the flow rate of the liquid refrigerant to adjust a supercooling degree. The respective indoor expansion valves 22A, 22B,... reduce the pressure of the liquid refrigerant to attain a low-pressure gas-liquid two-phase refrigerant. The respective indoor heat exchangers 21A, 21B,... exchange the heat between the indoor air and the gas-liquid two-phase refrigerant to evaporate the refrigerant, and causes the gas refrigerant to flow out. The gas refrigerant flowing out from the respective indoor heat exchangers 21A, 21B,... is sent back to the outdoor unit 5 through the suction gas pipe shutoff valves 26A, 26B,... of the respective switching units 7A, 7B,.... At that time, the discharge gas pipe shutoff valves 25A, 25B,... are fully closed and the flow of the refrigerant in the connecting pipe 36 is blocked. The gas refrigerant that reaches the outdoor unit 5 is sucked into the accumulator 16 through the eighth branch pipe 68. The accumulator 16 separates a small amount of the liquid refrigerant mixed in the gas refrigerant. The gas refrigerant from which the liquid is separated flows out from the accumulator 16 and is sucked into the compressor 2. The sucked gas refrigerant is compressed in the compressor 2 and is discharged again from the compressor 2.

[0062] Next, the flowing direction of the refrigerant in the full heating operation is indicated with the broken line arrows in Fig 1. The refrigerant generally flows in a direction opposite to that in the full cooling operation. The third switching valve 12C is switched so as to connect the discharge side of the compressor 2 and the switching units 7A, 7B,.... That is, the second branch pipe 62 is connected to the 10th pipe 70. The discharge gas pipe shutoff valves 25A, 25B,... are fully opened to connect the discharge side of the compressor 2 and the indoor heat exchangers 21A, 21B,.... The suction gas pipe shutoff valves 26A, 26B,... are fully closed. The first switching valve 12A and the second switching valve 12B are switched so as to connect the two outdoor heat exchangers 13 (31a and 31b) to the suction side of the compressor 2.

[0063] The gas refrigerant from which the oil is separated flows out from the oil separator 11 and reaches the respective switching units 7A, 7B,... through the third switching valve 12C. The gas refrigerant that reaches the respective switching units 7A, 7B,... reaches the respective indoor heat exchangers 21A, 21B,... through the respective discharge gas pipe shutoff valves 25A, 25B,.... At that time, the suction gas pipe shutoff valves 26A, 26B,... are fully closed. The indoor heat exchangers 21A, 21B,... exchange the heat between the indoor air and the gas refrigerant to condense the refrigerant, and causes the liquid refrigerant to flow out. The liquid refrigerant flowing out from the indoor heat exchangers 21A, 21B,... reaches the two outdoor heat exchangers 13 (31a and 31b) through the respective indoor expansion valves 22A, 22B,..., the 11th pipes 71A, 71B,... inside the respective switching units 7A, 7B,..., and the two outdoor expansion valves 15 (15a and 15b). The two outdoor expansion valves 15 (15a and 15b) reduce the pressure of the liquid refrigerant to attain the low-pressure gas-liquid two-phase refrigerant. The two outdoor heat exchangers 13 (31a and 31b) exchange the heat between the outdoor air and the gas-liquid two-phase refrigerant to evaporate the refrigerant, and causes the gas refrigerant to flow out. The gas refrigerant flowing out from the two outdoor heat exchangers 13 (31a and 31b) is sucked into the accumulator 16 through the first switching valve 12A and the second switching valve 12B.

[0064] Fig. 2 is a diagram illustrating a first example of the flow of the refrigerant in a mixed cooling operation state of the air conditioner according to the present embodiment.

[0065] Fig. 2 illustrates a case of performing the cooling operation in which the two outdoor heat exchangers 13 (31a and 31b) function as condensers and the indoor heat exchangers 21A and 21B function as evaporators, and simultaneously performing the heating operation in which the indoor heat exchanger 21C functions as a condenser. The flowing direction of the refrigerant related to the cooling operation is indicated with solid line arrows in Fig. 2, and the flowing direction of the refrigerant related to the heating operation is indicated with broken line arrows in Fig. 2.

[0066] The control unit 19 controls the three switching valves 12A, 12B, and 12C, the plurality of discharge gas pipe shutoff valves 25A, 25B,..., and the plurality of suction gas pipe shutoff valves 26A, 26B,... based on the operation input to the remote controller (not illustrated), and executes the mixed cooling operation in the first example of the air conditioner 1.

[0067] In the case of the mixed cooling operation in the first example, the first switching valve 12A and the second switching valve 12B are switched so as to connect the discharge side of the compressor 2 to the two outdoor heat exchangers 13 (31a and 31b). The third switching valve 12C is switched so as to connect the discharge side of the compressor 2 and the switching units 7A, 7B,.... That is, the discharge side of the compressor 2 is connected to the two outdoor heat exchangers 13 (31a and 31b) and is also connected to the switching units 7A, 7B,... at the same time.

[0068] In the mixed cooling operation in the first example, the switching state of the third switching valve 12C is different as compared to the case of the full cooling operation, and an open / closed state of the discharge gas pipe shutoff valve 25C and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the heating operation is inverted.

[0069] The discharge gas pipe shutoff valves 25A and 25B connected to the indoor heat exchangers 21A and 21B that perform the cooling operation are fully closed, and the suction gas pipe shutoff valves 26A and 26B connected to the indoor heat exchangers 21A and 21B that perform the cooling operation are fully opened. The indoor heat exchangers 21A and 21B are connected to the suction side of the compressor 2.

[0070] The discharge gas pipe shutoff valve 25C connected to the indoor heat exchanger 21C that performs the heating operation is fully opened, and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the heating operation is fully closed. The indoor heat exchanger 21C is connected to the discharge side of the compressor 2.

[0071] The flow of the refrigerant in the mixed cooling operation in the first example will be described focusing on differences from the flow of the refrigerant in the full cooling operation. A portion of the gas refrigerant from which the oil is separated flows out from the oil separator 11 and reaches the two outdoor heat exchangers 13 (31a and 31b) through the first switching valve 12A and the second switching valve 12B, and a remaining portion of the gas refrigerant from which the oil is separated reaches the discharge gas pipe shutoff valves 25A, 25B,... of the respective switching units 7A, 7B,... through the third switching valve 12C. The fully closed discharge gas pipe shutoff valves 25A and 25B shut off the flow of the refrigerant to the indoor units 6A and 6B, and the fully opened discharge gas pipe shutoff valve 25C allows the flow of the refrigerant to the indoor unit 6C. The indoor heat exchanger 21C exchanges the heat between the indoor air and the gas refrigerant to condense the refrigerant, and causes the liquid refrigerant to flow out. The liquid refrigerant flowing out from the indoor heat exchanger 21C joins the refrigerant flowing into the other indoor heat exchangers 21A and 21B in the connecting pipe 35 through the indoor expansion valve 22C and the 11th pipe 71C inside the switching unit 7C.

[0072] Fig. 3 is a diagram illustrating a second example of the flow of the refrigerant in the mixed cooling operation state of the air conditioner according to the present embodiment.

[0073] Fig. 3 illustrates a case of performing the cooling operation in which the auxiliary heat exchanger 31b functions as a condenser and the indoor heat exchangers 21A and 21B function as evaporators, and simultaneously performing the heating operation in which the indoor heat exchanger 21C functions as a condenser. The flowing direction of the refrigerant related to the cooling operation is indicated with solid line arrows in Fig. 3, and the flowing direction of the refrigerant related to the heating operation is indicated with broken line arrows in Fig. 3.

[0074] The control unit 19 controls the three switching valves 12A, 12B, and 12C, the plurality of discharge gas pipe shutoff valves 25A, 25B,..., and the plurality of suction gas pipe shutoff valves 26A, 26B,... based on the operation input to the remote controller (not illustrated), and executes the mixed cooling operation in the second example of the air conditioner 1.

[0075] In the case of the mixed cooling operation in the second example, the first switching valve 12A is switched so as to shut off the main heat exchanger 31a from the discharge side of the compressor 2 and the second switching valve 12B is switched so as to connect the discharge side of the compressor 2 to the auxiliary heat exchanger 31b.

[0076] The third switching valve 12C is switched so as to connect the discharge side of the compressor 2 and the plurality of switching units 7A, 7B,.... That is, the discharge side of the compressor 2 is connected to the auxiliary heat exchanger 31b and is also connected to the switching units 7A, 7B,... at the same time.

[0077] In the mixed cooling operation in the second example, the switching state of the first switching valve 12A and the third switching valve 12C is different as compared to the case of the full cooling operation, the open / closed state of the first outdoor expansion valve 15a is inverted, and the open / closed state of the discharge gas pipe shutoff valve 25C and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the heating operation is inverted.

[0078] The discharge gas pipe shutoff valves 25A and 25B connected to the indoor heat exchangers 21A and 21B that perform the cooling operation are fully closed, and the suction gas pipe shutoff valves 26A and 26B connected to the indoor heat exchangers 21A and 21B that perform the cooling operation are fully opened. The indoor heat exchangers 21A and 21B are connected to the suction side of the compressor 2.

[0079] The discharge gas pipe shutoff valve 25C connected to the indoor heat exchanger 21C that performs the heating operation is fully opened, and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the heating operation is fully closed. The indoor heat exchanger 21C is connected to the discharge side of the compressor 2.

[0080] In the mixed cooling operation in the second example, the refrigerant flows generally the same as that in the mixed cooling operation in the first example, however, the first switching valve 12A and the first outdoor expansion valve 15a shut off the flow of the refrigerant to the main heat exchanger 31a.

[0081] Such a mixed cooling operation in the second example is an operation mode advantageous when an outdoor air temperature is close to a target temperature, without requiring refrigerating capacity as compared to the mixed cooling operation in the first example.

[0082] Note that the outdoor unit 5 of the air conditioner 1 that does not perform the mixed cooling operation in the second example and performs the mixed cooling operation in the first example may include at least one outdoor heat exchanger 13 and at least one outdoor expansion valve 15, and may not include the second switching valve 12B connected to the auxiliary heat exchanger 31b.

[0083] Fig. 4 is a diagram illustrating an example of the flow of the refrigerant in a mixed heating operation state of the air conditioner according to the present embodiment.

[0084] Fig. 4 illustrates a case of the heating operation in which the two outdoor heat exchangers 13 (31a and 31b) function as evaporators and the indoor heat exchangers 21A and 21B function as condensers, and the cooling operation in which the indoor heat exchanger 21C functions as an evaporator. The flowing direction of the refrigerant related to the cooling operation is indicated with solid line arrows in Fig. 4, and the flowing direction of the refrigerant related to the heating operation is indicated with broken line arrows in Fig. 4.

[0085] The control unit 19 controls the three switching valves 12A, 12B, and 12C, the plurality of discharge gas pipe shutoff valves 25A, 25B,..., and the plurality of suction gas pipe shutoff valves 26A, 26B,... based on the operation input to the remote controller (not illustrated), and executes the mixed heating operation of the air conditioner 1.

[0086] The switching state of the three switching valves 12A, 12B, and 12C in the mixed heating operation is the same as the switching state of the three switching valves 12A, 12B, and 12C in the full heating operation.

[0087] In the mixed heating operation, the open / closed state of the discharge gas pipe shutoff valve 25C and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the cooling operation is inverted as compared to the case of the full heating operation.

[0088] The discharge gas pipe shutoff valves 25A and 25B connected to the indoor heat exchangers 21A and 21B that perform the heating operation are fully opened, and the suction gas pipe shutoff valves 26A and 26B connected to the indoor heat exchangers 21A and 21B that perform the heating operation are fully closed. That is, the indoor heat exchangers 21A and 21B are connected to the discharge side of the compressor 2.

[0089] The discharge gas pipe shutoff valve 25C connected to the indoor heat exchanger 21C that performs the cooling operation is fully closed, and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the cooling operation is fully opened. That is, the indoor heat exchanger 21C is connected to the suction side of the compressor 2.

[0090] In the mixed heating operation, the refrigerant flows generally the same as that in the full heating operation, however, the liquid refrigerant flowing out from the indoor heat exchangers 21A and 21B is branched in the connecting pipe 35, is subjected to pressure reduction in the indoor expansion valve 22C, and reaches the indoor heat exchanger 21C. The indoor heat exchanger 21C exchanges the heat between the indoor air and the gas-liquid two-phase refrigerant to evaporate the refrigerant, and causes the gas refrigerant to flow out. The gas refrigerant flowing out from the indoor heat exchanger 21C is sucked into the accumulator 16 through the suction gas pipe shutoff valve 26C.

[0091] Next, the outdoor unit 5 will be described in detail.

[0092] Fig. 5 is an exploded perspective view of a first example of the outdoor unit according to the embodiment of the present invention.

[0093] As illustrated in Fig. 5, the outdoor unit 5 according to the present embodiment includes a housing 81. The housing 81 is a box body in a rectangular parallelepiped shape that is long up and down. The housing 81 includes a bottom plate 82 that is rectangular in a planar view, four columns 83 rising from the bottom plate 82, a detachable rectangular front plate 85 that covers a front of the housing 81, a rectangular front upper plate 86 that covers an upper portion of the front of the housing 81, two rectangular side face upper plates 87 that cover upper portions of left and right side faces of the housing 81, a rectangular side face lower plate 88 that covers a lower front portion of the right side face of the housing 81, a rectangular back plate 89 that covers an upper portion of a back of the housing 81, and a fan guard 90 that covers a top surface of the housing 81.

[0094] The four columns 83 extend upwards from vicinities of four respective corners of the bottom plate 82.

[0095] Lower portions of the left and right side faces of the housing 81 and a lower portion of the back of the housing 81 are largely opened. This opening is a suction port that takes the outdoor air from an outer side of the outdoor unit 5 to an inner side by drive of the outdoor fan 17. The two outdoor heat exchangers 13 are disposed at the opening.

[0096] The housing 81 houses the compressor 2, the oil separator 11, the three switching valves 12A, 12B, and 12C, the two outdoor heat exchangers 13, the two outdoor expansion valves 15, the accumulator 16, and the refrigerant piping 8 that connects them. In addition, the housing 81 includes an electrical component box 91 that houses the control unit 19.

[0097] The outdoor fan 17 is disposed at a top portion of the housing 81. The outdoor fan 17 sucks the outdoor air from the suction port where the two outdoor heat exchangers 13 are disposed, and discharges it from a bell mouth 92. The outdoor fan 17 blows out the air toward above the outdoor unit 5. The outdoor fan 17 is supported on a fan base 93 supported by the four columns 83 of the housing 81. The fan base 93 supports the outdoor fan 17 and the bell mouth 92. The bell mouth 92 is an outlet of the outdoor fan 17, and rectifies the heat-exchanged outdoor air flowing out from the outdoor fan 17. The bell mouth 92 is surrounded on all four sides, front, back, left, and right, by the front upper plate 86, the two side face upper plates 87, and the back plate 89.

[0098] Fig. 6 is a front view of a first example of the outdoor unit according to the embodiment of the present invention.

[0099] Fig. 7 is a schematic front view of the first example of the outdoor unit according to the embodiment of the present invention.

[0100] Fig. 8 is a plan view of the first example of the outdoor unit according to the embodiment of the present invention.

[0101] Fig. 6 to Fig. 8 illustrate the bottom plate 82, the two outdoor heat exchangers 13, the three switching valves 12A, 12B, and 12C, the oil separator 11, the accumulator 16, and the refrigerant piping 8 of the outdoor unit 5, and the other main components are omitted.

[0102] When the front plate 85 as a detachable side face is detached from the housing 81, it is possible to directly view an inside of the outdoor unit 5 in a direction of an outline solid line arrow extending from the front to the back of the housing 81, which is illustrated in Fig. 8. In this state, equipment inside the outdoor unit 5 is maintained, replaced, or repaired.

[0103] As illustrated in Fig. 6 to Fig. 8, one of the outdoor heat exchangers 13 of the outdoor unit 5 according to the present embodiment is the main heat exchanger 31a as the first outdoor heat exchanger, and the other outdoor heat exchanger 13 is the auxiliary heat exchanger 31b as the second outdoor heat exchanger. The main heat exchanger 31a is disposed above the auxiliary heat exchanger 31b. The main heat exchanger 31a is preferably disposed right above the auxiliary heat exchanger 31b.

[0104] The plurality of paths 28 of the main heat exchanger 31a and the auxiliary heat exchanger 31b extend in a horizontal direction of the housing 81 to cause the refrigerant to flow. The plurality of fins of the main heat exchanger 31a and the auxiliary heat exchanger 31b extend in an up-down direction of the housing 81 orthogonally to the plurality of paths 28.

[0105] The main heat exchanger 31a and the auxiliary heat exchanger 31b have end faces 101 and 102 arranged on one plane. These end faces 101 and 102 face the horizontal direction of the housing 81.

[0106] The plurality of fins of the main heat exchanger 31a and the plurality of fins of the auxiliary heat exchanger 31b are divided. The end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b are preferably disposed practically on a single plane.

[0107] The main heat exchanger 31a and the auxiliary heat exchanger 31b may be obtained by dividing an integrated heat exchanger by a broken line D indicated in Fig. 6. For example, the main heat exchanger 31a is an upper half portion of the integrated heat exchanger, and the auxiliary heat exchanger 31b is a lower half portion of the integrated heat exchanger. The plurality of fins of the main heat exchanger 31a and the plurality of fins of the auxiliary heat exchanger 31b continue in series in both heat exchangers and spread over the both heat exchangers 31a and 31b. The integrated heat exchanger that includes the main heat exchanger 31a and the auxiliary heat exchanger 31b and share the plurality of fins is excellent in a manufacturing cost compared to the main heat exchanger 31a and the auxiliary heat exchanger 31b that are divided into two. The plurality of paths 28 of the main heat exchanger 31a pass through an upper half portion of the plurality of fins, and the plurality of paths 28 of the auxiliary heat exchanger 31b pass through a lower half portion of the plurality of fins. In this case, one plane on which the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b are arranged is a single end face of the integrated heat exchanger. In other words, the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b form one continuous plane. This plane is one of two main surfaces of the fin positioned at one end of the integrated heat exchanger, and faces the horizontal direction of the housing 81 similarly to the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b.

[0108] In addition, the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b face an inner surface of the detachable front plate 85. That is, the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b face the front of the housing 81.

[0109] Each path 28 has a refrigerant inlet and a refrigerant outlet disposed on the end face 101 of the main heat exchanger 31a or the end face 102 of the auxiliary heat exchanger 31b arranged on one plane. In other words, inlets and outlets of the plurality of paths 28 of the main heat exchanger 31a are disposed on the end face 101 of the main heat exchanger 31a, and inlets and outlets of the plurality of paths 28 of the auxiliary heat exchanger 31b are disposed on the end face 102 of the auxiliary heat exchanger 31b.

[0110] The accumulator 16 and the oil separator 11 are disposed so as to face an inner surface of the outdoor heat exchanger 13. The accumulator 16 and the oil separator 11 face an inner surface of the auxiliary heat exchanger 31b positioned below.

[0111] The three switching valves 12A, 12B, and 12C are disposed above the accumulator 16 and the oil separator 11. Further, the three switching valves 12A, 12B, and 12C are closer to the front of the housing 81 than the accumulator 16 and the oil separator 11 are.

[0112] The 10th pipe 70 is provided with a gas valve 105 that shuts off outflow of the refrigerant from the outdoor unit 5 to the outside at the time of factory shipping and at the time of installation work. The gas valve 105 is a shutoff valve that can be manually opened and closed, and is provided with an operation unit for a manual operation. The gas valve 105 is disposed such that the operation unit faces the inner surface of the front plate 85. In other words, the gas valve 105 is disposed so as to be easily operated to be opened and closed from the front side of the housing 81 in a state where the front plate 85 is detached from the housing 81.

[0113] Fig. 9 is a perspective view of the three switching valves of the outdoor unit according to the embodiment of the present invention.

[0114] An outline solid line arrow illustrated in Fig. 9 indicates a direction from the front to the back of the housing 81. The end faces 101 and 102 of the two outdoor heat exchangers 13 are disposed on a right side of the second switching valve 12B when viewed in the direction indicated by the outline solid line arrow.

[0115] As illustrated in Fig. 9 in addition to Fig. 6 to Fig. 8, the first switching valve 12A of the outdoor unit 5 according to the present embodiment is closer to the end face 101 of the main heat exchanger 31a than the third switching valve 12C is, and the second switching valve 12B is closer to the end face 101 of the main heat exchanger 31a than the first switching valve 12A is. In other words, the three switching valves 12A, 12B, and 12C are arranged in an order of the second switching valve 12B, the first switching valve 12A, and the third switching valve 12C from the side closer to the end face 101 of the main heat exchanger 31a.

[0116] Further, the three switching valves 12A, 12B, and 12C are closer to the main heat exchanger 31a than to the auxiliary heat exchanger 31b. That is, the switching valves 12A, 12B, and 12C are arranged in the order of the second switching valve 12B, the first switching valve 12A, and the third switching valve 12C from the side closer to the main heat exchanger 31a.

[0117] In addition, the three switching valves 12A, 12B, and 12C are disposed on an outer side of a projection region A1 in a normal direction of the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b. In other words, the switching valves 12A, 12B, and 12C are disposed on the outer side of the projection region A1 in the normal direction of the end face of the outdoor heat exchanger 13. The projection region A1 faces the front of the housing 81.

[0118] The three switching valves 12A, 12B, and 12C are all four-way valves, and all have the same configuration. Hereinafter, the representative first switching valve 12A will be described.

[0119] The first switching valve 12A includes a valve body 111a, a valve box 112a that houses the valve body 111a movably in the horizontal direction, a first connecting port 115a connectable to a condenser at the time of the cooling operation, a second connecting port 116a connectable to an evaporator at the time of the cooling operation, a third connecting port 117a that hangs down below the valve box 112a and is connected to the discharge side of the compressor 2, and a fourth connecting port 118a that rises above the valve box 112a and is connected to the suction side of the compressor 2.

[0120] In addition, the first switching valve 12A includes a pilot solenoid valve 119a for moving the valve body 111a. The pilot solenoid valve 119a is connected to the inside of the valve box 112a through a plurality of small tubes 121a. The pilot solenoid valve 119a connects the first connecting port 115a and the third connecting port 117a of the first switching valve 12A and connects the second connecting port 116a and the fourth connecting port 118a of the first switching valve 12A in a state where a coil (not illustrated) is not energized. Further, the pilot solenoid valve 119a connects the first connecting port 115a and the fourth connecting port 118a of the first switching valve 12A and connects the second connecting port 116a and the third connecting port 117a of the first switching valve 12A in a state where the coil is energized.

[0121] The first connecting port 115a, the second connecting port 116a, and the fourth connecting port 118a are lined up in parallel in a longitudinal direction of the valve box 112a.

[0122] A first connecting port 115b of the second switching valve 12B is connected to the fourth pipe 64 that continues to the outdoor heat exchanger 13 (the auxiliary heat exchanger 31b).

[0123] A second connecting port 116b of the second switching valve 12B is closed by a sealing plug 125.

[0124] The first connecting port 115a of the first switching valve 12A is connected to the third pipe 63 that continues to the outdoor heat exchanger 13 (the main heat exchanger 31a).

[0125] The second connecting port 116a of the first switching valve 12A is closed by the sealing plug 125.

[0126] The first connecting port 115c of the third switching valve 12C is closed by the sealing plug 125.

[0127] The second connecting port 116c of the third switching valve 12C is connected to the 10th pipe 70 that continues to the discharge gas pipe shutoff valves 25A, 25B,... of the switching units 7A, 7B,....

[0128] The respective third connecting ports 117a, 117b, and 117c of the three switching valves 12A, 12B, and 12C are connected to the second branch pipe 62 that continues to the discharge side of the compressor 2 through the oil separator 11.

[0129] The respective fourth connecting ports 118a, 118b, and 118c of the three switching valves 12A, 12B, and 12C are connected to the eighth branch pipe 68 that continues to the suction side of the compressor 2 through the accumulator 16.

[0130] The respective switching valves 12A, 12B, and 12C have center lines of long cylindrical valve boxes 112a, 112b, and 112c in the horizontal direction. In addition, the respective switching valves 12A, 12B, and 12C are disposed such that pilot solenoid valves 119a, 119b, and 119c face the inner surface of the detachable front plate 85. In other words, all of the pilot solenoid valves 119a, 119b, and 119c face the inner surface of the front plate 85. In other words, all of the pilot solenoid valves 119a, 119b, and 119c are installed such that the coil can be easily attached and detached in the state where the front plate 85 is detached from the housing 81.

[0131] Further, the three switching valves 12A, 12B, and 12C are disposed practically at a same height position of the housing 81. A difference in height of these switching valves 12A, 12B, and 12C is preferably within a size of the switching valves 12A, 12B, and 12C before the refrigerant piping 8 is connected.

[0132] Then, the fourth pipe 64 extending from the second switching valve 12B to the auxiliary heat exchanger 31b is installed so as to hang down in the projection region A1 toward the auxiliary heat exchanger 31b.

[0133] The third pipe 63 extending from the first switching valve 12A to the main heat exchanger 31a is installed so as to cross above the second switching valve 12B toward the main heat exchanger 31a.

[0134] Functions of the three switching valves 12A, 12B, and 12C can be satisfied by three-way valves rather than four-way valves. However, the three switching valves 12A, 12B, and 12C according to the present embodiment and the four-way valve of an air conditioner of a different model are made common by applying the four-way valves that switch the cooling operation and the heating operation alone, such as the one disclosed in Japanese Patent Laid-Open No. 2017-180882, to the three switching valves 12A, 12B, and 12C.

[0135] Fig. 10 is a schematic front view of a first comparative example of the outdoor unit.

[0136] As illustrated in Fig. 10, an outdoor unit 201A of the first comparative example includes the three switching valves 12A, 12B, and 12C arranged in the order of the first switching valve 12A, the second switching valve 12B, and the third switching valve 12C from the side closer to the end face 101 of the main heat exchanger 31a.

[0137] In the first comparative example, the third pipe 63 extending from the first switching valve 12A to the main heat exchanger 31a is installed in a shortest route toward the main heat exchanger 31a.

[0138] However, the fourth pipe 64 extending from the second switching valve 12B to the auxiliary heat exchanger 31b makes a detour between the second switching valve 12B and the third switching valve 12C and below the second switching valve 12B, and is installed toward the auxiliary heat exchanger 31b. Such an installation route of the fourth pipe 64 in the first comparative example can be said to be a longer route than the installation route of the fourth pipe 64 of the outdoor unit 5 according to the present embodiment.

[0139] The installation route of the refrigerant piping 8 of the outdoor unit 5 according to the present embodiment, that is illustrated in Fig. 7, is excellent in total extension of the refrigerant piping 8 and simplicity of the installation route as compared to the installation route of the refrigerant piping 8 in the first comparative example.

[0140] Fig. 11 is a schematic front view of a second comparative example of the outdoor unit.

[0141] As illustrated in Fig. 11, an outdoor unit 201B of the second comparative example includes the three switching valves 12A, 12B, and 12C arranged in the order of the first switching valve 12A, the second switching valve 12B, and the third switching valve 12C from the side closer to the end face 101 of the main heat exchanger 31a.

[0142] In the second comparative example, the third pipe 63 extending from the first switching valve 12A to the main heat exchanger 31a is installed in the shortest route toward the main heat exchanger 31a.

[0143] However, the fourth pipe 64 extending from the second switching valve 12B to the auxiliary heat exchanger 31b makes a detour above the first switching valve 12A, and is installed toward the auxiliary heat exchanger 31b so as to hang down in the projection region A1. Such an installation route of the fourth pipe 64 in the second comparative example can be said to be a longer route than the installation route of the fourth pipe 64 of the outdoor unit 5 according to the present embodiment.

[0144] In addition, the second comparative example requires room between the first switching valve 12A closest to the end face 101 of the main heat exchanger 31a and the end face 101 of the main heat exchanger 31a in order to avoid three-dimensional interference of the third pipe 63, the fourth pipe 64, and the header 29 of the main heat exchanger 31a. This room increases a width dimension of the outdoor unit 201B and obstructs miniaturization of the outdoor unit 201B.

[0145] The installation route of the refrigerant piping 8 of the outdoor unit 5 according to the present embodiment, that is illustrated in Fig. 7, is excellent in the total extension of the refrigerant piping 8, the simplicity of the installation route, and miniaturization of the outdoor unit 5 as compared to the installation route of the refrigerant piping 8 in the second comparative example.

[0146] Next, an outdoor unit 5A of a second example according to the present embodiment will be described.

[0147] Fig. 12 is a front view of the second example of the outdoor unit according to the embodiment of the present invention.

[0148] Fig. 13 is a schematic front view of the second example of the outdoor unit according to the embodiment of the present invention.

[0149] Fig. 14 is a plan view of the second example of the outdoor unit according to the embodiment of the present invention.

[0150] As illustrated in Fig. 12 to Fig. 14, the outdoor unit 5A according to the present embodiment is provided with four outdoor heat exchangers 13A. The four outdoor heat exchangers 13A include two main heat exchangers 31a and two auxiliary heat exchangers 31b. The two main heat exchangers 31a are connected in parallel between the first switching valve 12A and the first outdoor expansion valve 15a. The two auxiliary heat exchangers 31b are connected in parallel between the second switching valve 12B and the second outdoor expansion valve 15b.

[0151] The number of the second outdoor expansion valves 15b may be the same as the number of the auxiliary heat exchangers 31b. In this case, one auxiliary heat exchanger 31b and one second outdoor expansion valve 15b are connected in series, the other auxiliary heat exchanger 31b and the other second outdoor expansion valve 15b are connected in series, and those two series systems are connected in parallel.

[0152] Fig. 12 to Fig. 14 illustrate the bottom plate 82, the four outdoor heat exchangers 13A, the three switching valves 12A, 12B, and 12C, the oil separator 11, the accumulator 16, and the refrigerant piping 8 of the outdoor unit 5A, and the other main components are omitted.

[0153] When the front plate 85 as the detachable side face is detached from the housing 81, it is possible to directly view the inside of the housing 81 in the direction of an outline solid line arrow extending from the front to the back of the housing 81, which is illustrated in Fig. 14. In this state, equipment inside the outdoor unit 5A is maintained, replaced, or repaired.

[0154] With a center plane that extends in a front-back direction of the housing 81 and bisects the housing 81 to left and right as a reference, the four outdoor heat exchangers 13A draw a practically bilaterally symmetrical shape. The two outdoor heat exchangers 13A on the right side spread on a right half of the back of the housing 81 and a right side face of the housing 81 from one end face 131 positioned in the right side vicinity of the center plane CP of the housing 81 to the back of the housing 81. The two outdoor heat exchangers 13A on the left side spread on a left half of the back of the housing 81 and a left side face of the housing 81 from one end face 132 positioned in the left side vicinity of the center plane CP of the housing 81 to the back of the housing 81.

[0155] The left and right outdoor heat exchangers 13A all have the same configuration. Hereinafter, the representative right outdoor heat exchangers 13A will be described. The configurations same as those of the outdoor heat exchanger 13 of the outdoor unit 5 in the first example are denoted by same reference signs and redundant description will be omitted.

[0156] One of the right outdoor heat exchangers 13A is the main heat exchanger 31a as the first outdoor heat exchanger, and the other right outdoor heat exchanger 13A is the auxiliary heat exchanger 31b as the second outdoor heat exchanger. The main heat exchanger 31a is disposed above the auxiliary heat exchanger 31b. The main heat exchanger 31a is preferably disposed right above the auxiliary heat exchanger 31b.

[0157] Then, the end face 101 of the right main heat exchanger 31a and the end face 101 of the left main heat exchanger 31a are disposed in mirror-image symmetry. In addition, the end face 102 of the right auxiliary heat exchanger 31b and the end face 102 of the left auxiliary heat exchanger 31b are disposed in the mirror-image symmetry.

[0158] The oil separator 11 is disposed so as to face the inner surface of the left outdoor heat exchanger 13A. The oil separator 11 faces the inner surface of the left auxiliary heat exchanger 31b.

[0159] The accumulator 16 is disposed so as to face the inner surface of the right outdoor heat exchanger 13A. The accumulator 16 faces the inner surface of the right auxiliary heat exchanger 31b.

[0160] The three switching valves 12A, 12B, and 12C are disposed on the right side of the housing 81 where the accumulator 16 is disposed, that is, on the right side of the center plane CP.

[0161] Note that arrangement of the equipment such as the four outdoor heat exchangers 13A, the three switching valves 12A, 12B, and 12C, the oil separator 11, the accumulator 16, and the refrigerant piping 8 inside the outdoor unit 5A may be left / right inverted with respect to the center plane CP of the housing 81.

[0162] Fig. 15 is a perspective view of the three switching valves of the outdoor unit according to the embodiment of the present invention.

[0163] An outline solid line arrow illustrated in Fig. 15 indicates the direction from the front to the back of the housing 81. The end faces 131 and 132 of the two outdoor heat exchangers 13A are disposed on the left side of the second switching valve 12B when viewed in the direction indicated by the outline solid line arrow.

[0164] As illustrated in Fig. 15 in addition to Fig. 12 to Fig. 14, the first switching valve 12A of the outdoor unit 5A according to the present embodiment is closer to the end face 101 of the two main heat exchangers 31a than the third switching valve 12C is, and the second switching valve 12B is closer to the end face 101 of the two main heat exchangers 31a than the first switching valve 12A is. In other words, the three switching valves 12A, 12B, and 12C are arranged in the order of the second switching valve 12B, the first switching valve 12A, and the third switching valve 12C from the side closer to the end face 101 of the two main heat exchangers 31a.

[0165] Further, the three switching valves 12A, 12B, and 12C are closer to the two main heat exchangers 31a than to the two auxiliary heat exchangers 31b. That is, the switching valves 12A, 12B, and 12C are arranged in the order of the second switching valve 12B, the first switching valve 12A, and the third switching valve 12C from the side closer to the two main heat exchangers 31a.

[0166] In addition, the three switching valves 12A, 12B, and 12C are disposed on the outer side of a projection region A2 in a front direction of the housing 81, including the end face 101 of the two main heat exchangers 31a and the end face 102 of the two auxiliary heat exchangers 31b. In other words, the switching valves 12A, 12B, and 12C are disposed on the outer side of the projection region A2 of the end face of the four outdoor heat exchangers 13A.

[0167] The fourth pipe 64 extending from the second switching valve 12B to the two left and right auxiliary heat exchangers 31b is installed so as to hang down in the projection region A2 toward the auxiliary heat exchangers 31b.

[0168] The third pipe 63 extending from the first switching valve 12A to the two left and right main heat exchangers 31a is installed so as to cross above the second switching valve 12B toward the main heat exchangers 31a.

[0169] Fig. 16 is a schematic front view of a third comparative example of the outdoor unit.

[0170] As illustrated in Fig. 16, an outdoor unit 201C of the third comparative example includes the three switching valves 12A, 12B, and 12C arranged in the order of the first switching valve 12A, the second switching valve 12B, and the third switching valve 12C from the side closer to the end face 101 of the two main heat exchangers 31a.

[0171] In the third comparative example, the third pipe 63 extending from the first switching valve 12A to the two main heat exchangers 31a is installed in the shortest route toward the main heat exchangers 31a.

[0172] However, the fourth pipe 64 extending from the second switching valve 12B to the two auxiliary heat exchangers 31b makes a detour on the left side of the end face 101 of the two main heat exchangers 31a and is installed toward the two auxiliary heat exchangers 31b. Such an installation route of the fourth pipe 64 in the third comparative example can be said to be a longer route than the installation route of the fourth pipe 64 of the outdoor unit 5A according to the present embodiment.

[0173] The installation route of the refrigerant piping 8 of the outdoor unit 5A according to the present embodiment, which is illustrated in Fig. 15, is excellent in the total extension of the refrigerant piping 8 and the simplicity of the installation route as compared to the installation route of the refrigerant piping 8 in the third comparative example.

[0174] Fig. 17 is a schematic front view of a fourth comparative example of the outdoor unit.

[0175] As illustrated in Fig. 17, an outdoor unit 201D of the fourth comparative example includes the three switching valves 12A, 12B, and 12C arranged in the order of the first switching valve 12A, the second switching valve 12B, and the third switching valve 12C from the side closer to the end face 101 of the two main heat exchangers 31a.

[0176] In the fourth comparative example, the third pipe 63 extending from the first switching valve 12A to the main heat exchangers 31a is installed in the shortest route toward the main heat exchangers 31a.

[0177] However, the fourth pipe 64 extending from the second switching valve 12B to the two auxiliary heat exchangers 31b makes a detour above the first switching valve 12A and is installed so as to hang down in the projection region A2 toward the two auxiliary heat exchangers 31b. Such an installation route of the fourth pipe 64 in the fourth comparative example can be said to be a longer route than the installation route of the fourth pipe 64 of the outdoor unit 5A according to the present embodiment.

[0178] In addition, the fourth comparative example requires room between the first switching valve 12A closest to the end face 101 of the two main heat exchangers 31a and the end face 101 of the two main heat exchangers 31a in order to avoid the three-dimensional interference of the third pipe 63, the fourth pipe 64, and the headers 29 of the two main heat exchangers 31a. This room increases a width dimension of the outdoor unit 201D and obstructs miniaturization of the outdoor unit 201D.

[0179] The installation route of the refrigerant piping 8 of the outdoor unit 5A according to the present embodiment, that is illustrated in Fig. 15, is excellent in the total extension of the refrigerant piping 8, the simplicity of the installation route, and the miniaturization of the outdoor unit 5A as compared to the installation route of the refrigerant piping 8 in the fourth comparative example.

[0180] Fig. 18 is a block diagram of a second form of the air conditioner according to the embodiment of the present invention.

[0181] As illustrated in Fig. 18, the air conditioner 1 according to the present embodiment may not include the plurality of switching units 7A, 7B,.... The connecting pipe 35 connects one pipe connecting port 41 of the outdoor unit 5 or 5A and the respective pipe connecting ports 51A, 51B,... of the plurality of indoor units 6A, 6B,.... The connecting pipe 36 connects one pipe connecting port 42 of the outdoor unit 5 or 5A and the respective pipe connecting ports 52A, 52B,... of the plurality of indoor units 6A, 6B,.... The connecting pipe 37 is not needed, and the pipe connecting port 43 is maintained in a closed state. The third switching valve 12C of the outdoor unit 5 or 5A is switched such that the refrigerant is sucked from the plurality of indoor units 6A, 6B,... to the compressor 2 during the cooling operation, and the refrigerant is sent from the compressor 2 to the plurality of indoor units 6A, 6B,... during the heating operation.

[0182] The air conditioner 1 may include a sealing plug 135 that closes the pipe connecting port 43 of the outdoor unit 5 or 5A.

[0183] That is, the air conditioner 1 can be utilized in the second form in which the pipe connecting port 43 is closed, the plurality of switching units 7A, 7B,... and the connecting pipe 37 are not provided, and the outdoor unit 5 or 5A and the plurality of indoor units 6A, 6B,... are directly connected by using the connecting pipes 35 and 36. The air conditioner 1 in the second form performs the cooling operation by circulating the refrigerant in a direction indicated with solid line arrows in Fig. 18, and performs heating by circulating the refrigerant in a direction indicated with broken line arrows in Fig. 18.

[0184] Thus, when the pipe connecting port 43 of the outdoor unit 5 or 5A is closed, the air conditioner 1 functions as a multi-type air conditioner that performs the full cooling operation or the full heating operation.

[0185] Now, the eighth branch pipe 68 not connected to the connecting pipe 37 is a pipe that connects the third switching valve 12C and the accumulator 16 disposed on the suction side of the compressor 2 and also connects the pipe connecting port 43 and the accumulator 16, and includes a branch portion where three pipes to the third switching valve 12C, the accumulator 16, and the pipe connecting port 43 intersect. A pipe between the branch portion and the pipe connecting port 43 becomes a so-called blind alley. There is a risk that the refrigerant and the refrigerator oil mixed in the refrigerant stay in the blind alley. In order to recover the refrigerant and the refrigerator oil staying in the blind alley of the eighth branch pipe 68, the air conditioner 1 may include a recovery pipe 136 indicated with a two-dot chain line, that is connected to the pipe connecting port 43 and the suction side of the accumulator 16.

[0186] As described above, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes the first switching valve 12A closer to the end face 101 of the main heat exchanger 31a than the third switching valve 12C is, and the second switching valve 12B closer to the end face 101 of the main heat exchanger 31a than the first switching valve 12A is. Consequently, the outdoor unit 5 or 5A is excellent in the total extension of the refrigerant piping 8, the simplicity of the installation route, and the miniaturization of the outdoor unit 5.

[0187] In addition, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes the three switching valves 12A, 12B, and 12C disposed on the outer side of the projection region A1 or A2 of the end face of the plurality of outdoor heat exchangers 13 or 13A including the projection region of the end face 101 of the main heat exchanger 31a. Consequently, the outdoor unit 5 or 5A makes it easy to view and approach the paths 28 of the plurality of outdoor heat exchangers 13 or 13A, and is excellent in workability to the paths 28.

[0188] Further, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment may include a heat exchanger for which the main heat exchanger 31a and the auxiliary heat exchanger 31b are integrated. This heat exchanger has the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b as one continuous plane. Consequently, the outdoor unit 5 or 5A makes it easier to view and approach the paths 28 of the plurality of outdoor heat exchangers 13 and 13A, and is more excellent in the workability to the paths 28.

[0189] In addition, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes three four-way valves as the three switching valves 12A, 12B, and 12C. The three switching valves 12A, 12B, and 12C according to the present embodiment and the four-way valve of an air conditioner of a different model are made common by appropriately closing connecting ports of the four-way valves and utilizing them.

[0190] Further, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes three four-way valves as the three switching valves 12A, 12B, and 12C. Then, the three four-way valves respectively provided with the valve boxes 112a, 112b, and 112c that house the valve bodies 111a, 111b, and 111c movably in the horizontal direction, the third connecting ports 117a, 117b, and 117c that hang down below the valve boxes 112a, 112b, and 112c and are connected to the discharge side of the compressor 2, and the fourth connecting ports 118a, 118b, and 118c that rise above the valve boxes 112a, 112b, and 112c and are connected to the suction side of the compressor 2. Consequently, the outdoor unit 5 or 5A is excellent in the total extension of the refrigerant piping 8 between the compressor 2 and the three switching valves 12A, 12B, and 12C, the simplicity of the installation route, and the miniaturization of the outdoor unit 5.

[0191] Additionally, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes the housing 81 provided with the detachable front plate 85. Then, the three switching valves 12A, 12B, and 12C include the pilot solenoid valves 119a, 119b, and 119c facing the inner surface of the front plate 85. Consequently, the outdoor unit 5 or 5A makes it easy to view and approach the coils put on the pilot solenoid valves 119a, 119b, and 119c of the three switching valves 12A, 12B, and 12C, and is excellent in workability to the coils.

[0192] Further, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes the three switching valves 12A, 12B, and 12C disposed above the accumulator 16. That is, in the state where the outdoor unit 5 or 5A is installed, the three switching valves 12A, 12B, and 12C can be disposed at a height of about several tens of centimeters from an installation surface of the outdoor unit 5 or 5A. Consequently, the three switching valves 12A, 12B, and 12C of the outdoor unit 5 or 5A are disposed at a height where work is easy compared to the case of being close to the bottom plate 82 of the housing 81.

[0193] Then, the air conditioner 1 according to the present embodiment includes the outdoor unit 5 or 5A, the plurality of indoor units 6A, 6B,..., and the plurality of switching units 7A, 7B,.... The air conditioner 1 including the plurality of switching units 7A, 7B,... can cause the flowing direction of the refrigerant flowing to the plurality of indoor units 6A, 6B,... to be different from each other to mix the indoor units 6A, 6B,... that perform the cooling operation and the indoor units 6A, 6B,... that perform the heating operation. The air conditioner 1 according to the present embodiment may include the outdoor unit 5 or 5A and the plurality of indoor units 6A, 6B,... and have one of branches of the third switching valve 12C closed. The air conditioner 1 which does not include the plurality of switching units 7A, 7B,... and has one of the branches of the third switching valve 12C closed unifies the flowing direction of the refrigerant flowing to the plurality of indoor units 6A, 6B,... to cause all of the indoor units 6A, 6B,... to perform the cooling operation or the heating operation. That is, the air conditioner 1 can function as a heat-recovery multi-type air conditioner by selecting the plurality of switching units 7A, 7B,..., and function as a multi-type air conditioner by selecting non-application of the plurality of switching units 7A, 7B,....

[0194] Therefore, according to the outdoor unit 5 or 5A of the air conditioner 1 and the air conditioner 1 according to the present embodiment, the connection of the plurality of outdoor heat exchangers 13 or 13A, the discharge side of the compressor 2 and the suction side of the compressor 2 can be switched and the installation route of the refrigerant piping 8 is excellent.

[0195] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.Reference Signs List

[0196] 1...air conditioner, 2...compressor, 2a...accumulator, 5, 5A...outdoor unit, 6A, 6B, 6C...indoor unit, 7A, 7B, 7C...switching unit, 8... refrigerant piping, 11... oil separator, 12A...first switching valve, 12B...second switching valve, 12C...third switching valve, 13, 13A...outdoor heat exchanger, 15, 15a, 15b...outdoor expansion valve, 16...accumulator, 17...outdoor fan, 18...inverter circuit, 19...control unit, 21A, 21B, 21C...indoor heat exchanger, 22A, 22B, 22C...indoor expansion valve, 23A, 23B, 23C...indoor fan, 25A, 25B, 25C...discharge gas pipe shutoff valve, 26A, 26B, 26C...suction gas pipe shutoff valve, 28...path, 29...header, 31a...main heat exchanger, 31b...auxiliary heat exchanger, 35, 36, 37, 38A, 38B, 38C, 39A, 39B, 39C...connecting pipe, 41, 42, 43...pipe connecting port of outdoor unit, 45A, 45B, 45C, 46A, 46B, 46C, 47A, 47B, 47C...pipe connecting port on outdoor unit side of switching unit, 48A, 48B, 48C, 49A, 49B, 49C...pipe connecting port on indoor unit side of switching unit, 51A, 51B, 51C, 52A, 52B, 52C...pipe connecting port of indoor unit, 61...first pipe, 62...second branch pipe, 63...third pipe, 64... fourth pipe, 65...fifth pipe, 66...sixth pipe, 67...seventh branch pipe, 68...eighth branch pipe, 69...ninth pipe, 70...10th pipe, 71A, 71B, 71C...11th pipe, 72A, 72B, 72C...12th branch pipe, 73A, 73B, 73C...13th pipe, 74A, 74B, 74C...14th pipe, 75A, 75B, 75C...15th pipe, 76A, 76B, 76C...16th pipe, 77A, 77B, 77C...17th pipe, 81...housing, 82...bottom plate, 83...column, 85...front plate, 86...front upper plate, 87... side face upper plate, 88... side face lower plate, 89...back plate, 90...fan guard, 91...electrical component box, 92...bell mouth, 93...fan base, 101, 102...end face of heat exchanger, 105...gas valve, 111a, 111b, 111c...valve body, 112a, 112b, 112c...valve box, 115a, 115b, 115c...first connecting port, 116a, 116b, 116c...second connecting port, 117a, 117b, 117c...third connecting port, 118a, 118b, 118c...fourth connecting port, 119a, 119b, 119c...pilot solenoid valve, 121a, 121b, 121c...small tube, 125...sealing plug, 131, 132...end face of heat exchanger, 135...sealing plug, 136...recovery pipe, 201A, 201B, 201C, 201D... comparative example of outdoor unit.

Examples

Embodiment Construction

[0020]An embodiment of an outdoor unit of an air conditioner according to the present invention and an embodiment of the air conditioner according to the present invention will be described with reference to Fig. 1 to Fig. 18. Note that same or corresponding configurations are denoted by same reference signs in a plurality of drawings.

[0021] Fig. 1 is a block diagram of the air conditioner according to the embodiment of the present invention.

[0022]As illustrated in Fig. 1, an air conditioner 1 according to the present invention is a heat-recovery multi-type air conditioner. The air conditioner 1 includes at least one outdoor unit 5 provided with a compressor 2 that compresses a refrigerant, a plurality of indoor units 6A, 6B,..., and a plurality of switching units 7A, 7B,... capable of switching a flowing direction of the refrigerant flowing to the indoor units 6A, 6B,.... In addition, the air conditioner 1 includes refrigerant piping 8 that successively connects the outdoor unit 5,...

Technical Field

[0001] Embodiments of the present invention relate to an outdoor unit of an air conditioner, and an air conditioner.Background Art

[0002] An air conditioner provided with an outdoor unit, a plurality of indoor units, a plurality of switching units, a first connecting pipe, a second connecting pipe, and a third connecting pipe is known. The outdoor unit includes an outdoor heat exchanger and a compressor. The outdoor unit includes an outdoor first pipe that connects the outdoor heat exchanger and the first connecting pipe, an outdoor second pipe that connects the compressor and the second connecting pipe, and an outdoor third pipe that connects the compressor and the third connecting pipe. Each indoor unit includes an indoor heat exchanger.

[0003] Each switching unit includes an indoor first pipe that connects the indoor heat exchanger and the first connecting pipe, an indoor second pipe that connects the indoor heat exchanger and the second connecting pipe, an indoor third pipe that connects the indoor heat exchanger and the third connecting pipe, and an indoor third pipe valve provided in the indoor third pipe. Each indoor third pipe valve switches a connection state of the three pipes of the outdoor unit and the two pipes of each indoor unit.

[0004] This conventional air conditioner can not only execute a heating operation in all of the indoor units or execute a cooling operation in all of the indoor units but also execute the heating operation in some indoor units and execute the cooling operation in the remaining indoor units.Prior Art DocumentsPatent Documents

[0005] [Patent Document 1] JP 2017-180882 ASummary of the InventionProblems to be Solved by the Invention

[0006] Conventional air conditioners have room for improvement in pipe installation routes in an outdoor unit.

[0007] Therefore, an object of the present invention is to provide an outdoor unit of an air conditioner, or an air conditioner in which connection of a plurality of outdoor heat exchangers, a discharge side of a compressor, and a suction side of the compressor can be switched and which has excellent pipe installation routes.

[0008] To achieve the above object, an aspect of the present invention provides an outdoor unit of an air conditioner, the outdoor unit including: a compressor that compresses a refrigerant; a first outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; a first switching valve that connects a discharge side of the compressor to the first outdoor heat exchanger to cause the first outdoor heat exchanger to function as a condenser, or connects a suction side of the compressor to the first outdoor heat exchanger to cause the first outdoor heat exchanger to function as an evaporator; a second outdoor heat exchanger that exchanges heat between the refrigerant and the outdoor air; a second switching valve that connects the discharge side of the compressor to the second outdoor heat exchanger to cause the second outdoor heat exchanger to function as a condenser, or connects the suction side of the compressor to the second outdoor heat exchanger to cause the second outdoor heat exchanger to function as an evaporator; and a third switching valve that shuts off connection of the discharge side of the compressor and indoor heat exchangers of all of indoor units to cause the first outdoor heat exchanger and the second outdoor heat exchanger to function as condensers, or connects the discharge side of the compressor to the indoor heat exchanger of at least one of the indoor units to cause the indoor heat exchanger of the at least one of the indoor units to function as a condenser. The first switching valve is closer to the first heat exchanger than the third switching valve is. The second switching valve is closer to the first heat exchanger than the first switching valve is.

[0009] It may be desired that the first switching valve, the second switching valve, and the third switching valve are disposed on an outer side of a projection region in a normal direction of an end face of the first heat exchanger.

[0010] It may be desired that the first outdoor heat exchanger and the second outdoor heat exchanger are integrated and the end face of the first outdoor heat exchanger and an end face of the second outdoor heat exchanger form one continuous plane.

[0011] It may be desired that the first switching valve, the second switching valve, and the third switching valve are four-way valves, and include a first connecting port connectable to a condenser and a second connecting port connectable to an evaporator, and either one of the first connecting port and the second connecting port is closed.

[0012] It may be further desired that a housing that houses the compressor, the first outdoor heat exchanger, the second outdoor heat exchanger, the first switching valve, the second switching valve, and the third switching valve. The end face of the first outdoor heat exchanger and the end face of the second outdoor heat exchanger face a horizontal direction of the housing, and The first switching valve, the second switching valve, and the third switching valve each include a valve body, a valve box that houses the valve body movably in the horizontal direction, a third connecting port that hangs down below the valve box and is connected to the discharge side of the compressor, and a fourth connecting port that rises above the valve box and is connected to the suction side of the compressor.

[0013] It may be desired that the housing has a detachable side face, and the first switching valve, the second switching valve, and the third switching valve each include a pilot solenoid valve facing an inner surface of the side face.

[0014] It may be further desired that an accumulator connected to the suction side of the compressor. The first heat exchanger is disposed above the second heat exchanger, and the first switching valve, the second switching valve, and the third switching valve are disposed above the accumulator.

[0015] To achieve the above object, an aspect of the present invention provides an air conditioner including: the outdoor unit; a plurality of the indoor units; and a plurality of switching units that switch a flowing direction of the refrigerant flowing to the corresponding indoor units. The outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger. The indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger. The flowing direction of the refrigerant flowing to the plurality of indoor units is caused to be different from each other to mix the indoor units that perform a cooling operation and the indoor units that perform a heating operation.

[0016] To achieve the above object, an aspect of the present invention provides an air conditioner including: the outdoor unit; and a plurality of the indoor units. The outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger. The indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger. One of branches of the third switching valve is closed so as to cause the refrigerant to be sucked to the compressor through the third switching valve during a cooling operation and to cause the refrigerant to be sent to the plurality of indoor units through the third switching valve during a heating operation.

[0017] To achieve the above object, an aspect of the present invention provides an air conditioner including: the outdoor unit; and a plurality of the indoor units. The outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger. The indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger. A flowing direction of the refrigerant flowing to the plurality of indoor units is caused to be different from each other to mix the indoor units that perform a cooling operation and the indoor units that perform a heating operation when a plurality of switching units that switch the flowing direction of the refrigerant flowing to the corresponding indoor units are provided. One of branches of the third switching valve is closed so as to cause the refrigerant to be sucked to the compressor through the third switching valve during the cooling operation and to cause the refrigerant to be sent to the plurality of indoor units through the third switching valve during the heating operation, the flowing direction of the refrigerant flowing to the plurality of indoor units is unified, and all of the indoor units are caused to perform the cooling operation or the heating operation when the plurality of switching units are not provided.EFFECTS OF INVENTION

[0018] The present invention can provide an outdoor unit of an air conditioner, or an air conditioner in which connection of a plurality of outdoor heat exchangers, a discharge side of a compressor, and a suction side of the compressor can be switched and which has excellent pipe installation routes.BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 is a block diagram of the air conditioner according to the embodiment of the present invention. Fig. 2 is a diagram illustrating a first example of the flow of the refrigerant in a mixed cooling operation state of the air conditioner according to the present embodiment. Fig. 3 is a diagram illustrating a second example of the flow of the refrigerant in the mixed cooling operation state of the air conditioner according to the present embodiment. Fig. 4 is a diagram illustrating an example of the flow of the refrigerant in a mixed heating operation state of the air conditioner according to the present embodiment. Fig. 5 is an exploded perspective view of a first example of the outdoor unit according to the embodiment of the present invention. Fig. 6 is a front view of a first example of the outdoor unit according to the embodiment of the present invention. Fig. 7 is a schematic front view of the first example of the outdoor unit according to the embodiment of the present invention. Fig. 8 is a plan view of the first example of the outdoor unit according to the embodiment of the present invention. Fig. 9 is a perspective view of the three switching valves of the outdoor unit according to the embodiment of the present invention. Fig. 10 is a schematic front view of a first comparative example of the outdoor unit. Fig. 11 is a schematic front view of a second comparative example of the outdoor unit. Fig. 12 is a front view of the second example of the outdoor unit according to the embodiment of the present invention. Fig. 13 is a schematic front view of the second example of the outdoor unit according to the embodiment of the present invention. Fig. 14 is a plan view of the second example of the outdoor unit according to the embodiment of the present invention. Fig. 15 is a perspective view of the three switching valves of the outdoor unit according to the embodiment of the present invention. Fig. 16 is a schematic front view of a third comparative example of the outdoor unit. Fig. 17 is a schematic front view of a fourth comparative example of the outdoor unit. Fig. 18 is a block diagram of a second form of the air conditioner according to the embodiment of the present invention. Description of Embodiments

[0020] An embodiment of an outdoor unit of an air conditioner according to the present invention and an embodiment of the air conditioner according to the present invention will be described with reference to Fig. 1 to Fig. 18. Note that same or corresponding configurations are denoted by same reference signs in a plurality of drawings.

[0021] Fig. 1 is a block diagram of the air conditioner according to the embodiment of the present invention.

[0022] As illustrated in Fig. 1, an air conditioner 1 according to the present invention is a heat-recovery multi-type air conditioner. The air conditioner 1 includes at least one outdoor unit 5 provided with a compressor 2 that compresses a refrigerant, a plurality of indoor units 6A, 6B,..., and a plurality of switching units 7A, 7B,... capable of switching a flowing direction of the refrigerant flowing to the indoor units 6A, 6B,.... In addition, the air conditioner 1 includes refrigerant piping 8 that successively connects the outdoor unit 5, the plurality of switching units 7A, 7B,..., and the plurality of indoor units 6A, 6B,... to circulate the refrigerant.

[0023] The air conditioner 1 circulates the refrigerant between the outdoor unit 5 and the plurality of indoor units 6A, 6B,..., and performs a full cooling operation of causing the outdoor unit 5 to function as a condenser and causing all of the indoor units 6A, 6B,... to function as evaporators, and a full heating operation of causing the outdoor unit 5 to function as an evaporator and causing all of the indoor units 6A, 6B,... to function as condensers.

[0024] Further, the air conditioner 1 can mix the indoor units 6A, 6B,... that perform a cooling operation and the indoor units 6A, 6B,... that perform a heating operation by making the flowing direction of the refrigerant flowing to the plurality of indoor units 6A, 6B,... be different from each other. The air conditioner 1 performs a mixed cooling operation of causing the outdoor unit 5 to function as a condenser, causing some indoor units 6A and 6B to function as evaporators, and causing the remaining indoor unit 6C to function as a condenser, and a mixed heating operation of causing the outdoor unit 5 to function as an evaporator, causing some indoor units 6A and 6B to function as condensers, and causing the remaining indoor unit 6C to function as an evaporator. The mixed cooling operation is an operation mainly for cooling, in which the cooling operation is performed in a large number of the indoor units 6A and 6B and the heating operation is performed in a small number of the indoor unit 6C. The mixed heating operation is an operation mainly for heating, in which the heating operation is performed in a large number of the indoor units 6A and 6B and the cooling operation is performed in a small number of the indoor unit 6C.

[0025] The outdoor unit 5 includes the compressor 2 that compresses and discharges the sucked refrigerant, an oil separator 11 provided on a discharge side of the compressor 2, at least three switching valves 12A, 12B, and 12C that switch a circulation route of the refrigerant circulated between the outdoor unit 5 and the indoor units 6A, 6B,..., two outdoor heat exchangers 13 that exchange heat between the refrigerant and outdoor air, two outdoor expansion valves 15 that reduce a pressure of the refrigerant flowing from the indoor units 6A, 6B,... to the respective outdoor heat exchangers 13, and an accumulator 16 provided on a suction side of the compressor 2. In addition, the outdoor unit 5 includes an outdoor fan 17 that causes the outdoor air heat-exchanged in the two outdoor heat exchangers 13 to flow. Further, the outdoor unit 5 includes an inverter circuit 18 that controls an operating frequency of the compressor 2, and a control unit 19 that controls the inverter circuit 18.

[0026] The plurality of indoor units 6A, 6B,... all have a similar configuration. Hereinafter, one representative indoor unit 6A will be described. The indoor unit 6A includes an indoor heat exchanger 21A that exchanges heat between the refrigerant and indoor air, and an indoor expansion valve 22A that reduces the pressure of the refrigerant flowing from the outdoor unit 5 to the indoor heat exchanger 21A. In addition, the indoor unit 6A includes an indoor fan 23A that causes the indoor air heat-exchanged in the indoor heat exchanger 21A to flow. Further, the indoor unit 6A includes an indoor control unit (not illustrated).

[0027] The plurality of switching units 7A, 7B,... all have a similar configuration. Hereinafter, one representative switching unit 7A will be described. The switching unit 7A includes a discharge gas pipe shutoff valve 25A that allows or shuts off flow of the refrigerant from the compressor 2 to the indoor heat exchanger 21A, and a suction gas pipe shutoff valve 26A that allows or shuts off the flow of the refrigerant from the indoor heat exchanger 21A to the compressor 2. The indoor heat exchanger 21A of the indoor unit 6A functions as an evaporator by closing the discharge gas pipe shutoff valve 25A and opening the suction gas pipe shutoff valve 26A. The indoor heat exchanger 21A functions as a condenser by opening the discharge gas pipe shutoff valve 25A and closing the suction gas pipe shutoff valve 26A.

[0028] The compressor 2 is housed in the outdoor unit 5. The compressor 2 changes the operating frequency by output of the inverter circuit 18. The air conditioner 1 may include the plurality of compressors 2. In that case, the number of the inverter circuits 18 is preferably same as the number of the compressors 2 and each inverter circuit 18 individually controls the operating frequency of the corresponding compressor 2. The compressor 2 changes the operating frequency by known inverter control. The compressor 2 may be operated at a fixed operating frequency.

[0029] The compressor 2 includes a sealed case, a compression mechanism that compresses the refrigerant, and an electric motor that drives the compression mechanism. The sealed case houses the compression mechanism and the electric motor. The sealed case stores refrigerator oil that lubricates the compression mechanism. The discharge side of the compressor 2 is connected to the oil separator 11. The suction side of the compressor 2 is connected to the accumulator 16. Further, the compressor 2 includes an accumulator 2a of a capacity smaller than that of the accumulator 16. This small-capacity accumulator 2a is a gas-liquid separator that separates a gas refrigerant and a liquid refrigerant and sends the gas refrigerant to the compressor 2. The small-capacity accumulator 2a is also referred to as a suction muffler or a suction cup, and is provided between the suction side of the compressor 2 and the accumulator 16 of a large capacity.

[0030] The oil separator 11 separates the gas refrigerant and the refrigerator oil discharged from the compressor 2. The refrigerator oil separated in the oil separator 11 is returned to the compressor 2 through a return pipe (not illustrated). The oil separator 11 is a centrifugal separator for example.

[0031] Each outdoor heat exchanger 13 and each indoor heat exchanger 21A are fin-and-tube type heat exchangers for example. Each outdoor heat exchanger 13 and each indoor heat exchanger 21A include a plurality of paths 28 through which the refrigerant flows, a header 29 that distributes the refrigerant to the plurality of paths 28 or merges the refrigerant distributed to the plurality of paths 28, and a plurality of fins that extend orthogonally to the plurality of paths 28.

[0032] The two outdoor heat exchangers 13 include a main heat exchanger 31a as a first outdoor heat exchanger, and an auxiliary heat exchanger 31b as a second outdoor heat exchanger connected in parallel with the main heat exchanger 31a. The main heat exchanger 31a is connected to the first switching valve 12A. The auxiliary heat exchanger 31b is connected to the second switching valve 12B.

[0033] The switching valves 12A, 12B, and 12C are electrically connected to the control unit 19 by using a signal line (not illustrated), respectively. The air conditioner 1 switches the cooling operation (the flow of the refrigerant indicated with solid line arrows in Fig. 1) and the heating operation (the flow of the refrigerant indicated with broken line arrows in Fig. 1) by switching the flowing direction of the refrigerant with the three switching valves 12A, 12B, and 12C.

[0034] The first switching valve 12A connects the discharge side of the compressor 2 to the main heat exchanger 31a to cause the main heat exchanger 31a to function as a condenser. In addition, the first switching valve 12A connects the suction side of the compressor 2 to the main heat exchanger 31a to cause the main heat exchanger 31a to function as an evaporator.

[0035] The second switching valve 12B connects the discharge side of the compressor 2 to the auxiliary heat exchanger 31b to cause the auxiliary heat exchanger 31b to function as a condenser. In addition, the second switching valve 12B connects the suction side of the compressor 2 to the auxiliary heat exchanger 31b to cause the auxiliary heat exchanger 31b to function as an evaporator.

[0036] The third switching valve 12C shuts off connection of the discharge side of the compressor 2 and indoor heat exchangers 21A, 21B,... of all of the indoor units 6A, 6B,... to cause the two outdoor heat exchangers 13 to function as condensers, or connects the discharge side of the compressor 2 to the indoor heat exchangers 21A, 21B,... of at least one of the indoor units 6A, 6B,... to cause the indoor heat exchangers 21A, 21B,... of at least one of the indoor units 6A, 6B,... to function as condensers.

[0037] The two outdoor expansion valves 15 includes a first outdoor expansion valve 15a connected to the main heat exchanger 31a and a second outdoor expansion valve 15b connected to the auxiliary heat exchanger 31b.

[0038] The main heat exchanger 31a is disposed between the first switching valve 12A and the first outdoor expansion valve 15a, and the auxiliary heat exchanger 31b is disposed between the second switching valve 12B and the second outdoor expansion valve 15b. That is, the refrigerant is distributed on an intel side of the main heat exchanger 31a and the auxiliary heat exchanger 31b, and is merged on an outlet side of the main heat exchanger 31a and the auxiliary heat exchanger 31b.

[0039] The outdoor fan 17 and the indoor fan 23A are, for example, axial fans. The outdoor fan 17 accelerates heat exchange of the outdoor air and the refrigerant flowing to the two outdoor heat exchangers 13. The indoor fan 23A accelerates heat exchange of the indoor air and the refrigerant flowing to the indoor heat exchanger 21A.

[0040] The two outdoor expansion valves 15 and the indoor expansion valve 22A are, for example, electronic expansion valves (Pulse Motor Valves, PMV) for which a valve opening degree is adjustable. The electronic expansion valve includes a valve box provided with a through-hole, and a needle as a valve body movable forward and backward to / from the through-hole. When the needle closes the through-hole, the electronic expansion valve shuts off the flow of the refrigerant. At that time, the electronic expansion valve is in a closed state and the valve opening degree of the electronic expansion valve is smallest. When the needle is most separated from the through-hole, the electronic expansion valve maximizes a flow rate of the refrigerant. At that time, the electronic expansion valve is in a fully open state, and the valve opening degree of the electronic expansion valve is largest.

[0041] The accumulator 16 is a gas-liquid separator that separates the gas refrigerant and the liquid refrigerant and sends the gas refrigerant to the compressor 2.

[0042] The discharge gas pipe shutoff valve 25A and the suction gas pipe shutoff valve 26A may be a stop valve or may be an electronic expansion valve for which the opening degree is adjustable. The discharge gas pipe shutoff valve 25A allows or shuts off the flow of the refrigerant that is discharged from the compressor 2 and discharged to the indoor heat exchanger 21A through the third switching valve 12C. The suction gas pipe shutoff valve 26A allows or shuts off the flow of the refrigerant that is sucked from the indoor heat exchanger 21A to the compressor 2.

[0043] The refrigerant piping 8 includes three connecting pipes 35, 36, and 37 that connect the outdoor unit 5 and the plurality of switching units 7A, 7B,... to cause the refrigerant to move back and forth, and two connecting pipes 38A and 39A that connect the switching unit 7A and the indoor unit 6A to cause the refrigerant to move back and forth. The connecting pipes 35, 36, and 37 are branch pipes that connect the one outdoor unit 5 and the plurality of switching units 7A, 7B, ....

[0044] The outdoor unit 5 includes a pipe connecting port 41 that connects the connecting pipe 35, a pipe connecting port 42 that connects the connecting pipe 36, and a pipe connecting port 43 that connects the connecting pipe 37.

[0045] The switching unit 7A includes a pipe connecting port 45A that connects the connecting pipe 35, a pipe connecting port 46A that connects the connecting pipe 36, and a pipe connecting port 47A that connects the connecting pipe 37.

[0046] The connecting pipe 35 is the branch pipe that connects the one pipe connecting port 41 and a plurality of pipe connecting ports 45A, 45B,.... The connecting pipe 36 is the branch pipe that connects the one pipe connecting port 42 and a plurality of pipe connecting ports 46A, 46B,.... The connecting pipe 37 is the branch pipe that connects the one pipe connecting port 43 and a plurality of pipe connecting ports 47A, 47B,....

[0047] In addition, the switching unit 7A includes a pipe connecting port 48A that connects the connecting pipe 38A and a pipe connecting port 49A that connects the connecting pipe 39A.

[0048] The indoor unit 6A includes a pipe connecting port 51A that connects the connecting pipe 38A and a pipe connecting port 52A that connects the connecting pipe 39A.

[0049] The pipe connecting ports 41, 42, and 43 of the outdoor unit 5, the pipe connecting ports 45A, 45B, 45C, 46A, 46B, 46C, 47A, 47B, and 47C on the side of the outdoor unit 5 of the respective switching units 7A, 7B,..., the pipe connecting ports 48A, 48B, 48C, 49A, 49B, and 49C on the side of the indoor units 6A, 6B,... of the respective switching units 7A, 7B,..., and the pipe connecting ports 51A, 51B, 51C, 52A, 52B, and 52C of the indoor units 6A, 6B,... are packed valves (back seating type valves) having a structure that prevents the refrigerant from being discharged to the atmosphere.

[0050] The refrigerant piping 8 successively connects the compressor 2, the oil separator 11, the three switching valves 12A, 12B, and 12C, the two outdoor heat exchangers 13, the two outdoor expansion valves 15, a plurality of indoor expansion valves 22A, 22B,..., the plurality of indoor heat exchangers 21A, 21B,..., a plurality of discharge gas pipe shutoff valves 25A, 25B,..., a plurality of suction gas pipe shutoff valves 26A, 26B,..., and the accumulator 16.

[0051] The refrigerant piping 8 inside the outdoor unit 5 includes a first pipe 61 that connects the discharge side of the compressor 2 and the oil separator 11, a second branch pipe 62 that connects the oil separator 11 and the three switching valves 12A, 12B, and 12C, a third pipe 63 that connects the first switching valve 12A and one of the outdoor heat exchangers 13, a fourth pipe 64 that connects the second switching valve 12B and the other outdoor heat exchanger 13, a fifth pipe 65 that connects one of the outdoor heat exchangers 13 and one of the outdoor expansion valves 15, a sixth pipe 66 that connects the other outdoor heat exchanger 13 and the other outdoor expansion valve 15, and a seventh branch pipe 67 that connects the two outdoor expansion valves 15 and the pipe connecting port 41.

[0052] The first pipe 61 and the second branch pipe 62 are refrigerant feed pipes connected to the discharge side of the compressor 2 regardless of a switching state of the three switching valves 12A, 12B, and 12C.

[0053] Further, the refrigerant piping 8 inside the outdoor unit 5 includes an eighth branch pipe 68 that connects the pipe connecting port 43, the three switching valves 12A, 12B, and 12C, and the accumulator 16, a ninth pipe 69 that connects the accumulator 16 and the suction side of the compressor 2, and a 10th pipe 70 that connects the third switching valve 12C and the pipe connecting port 42.

[0054] The eighth branch pipe 68 and the ninth pipe 69 are refrigerant return pipes connected to the suction side of the compressor 2 regardless of the switching state of the three switching valves 12A, 12B, and 12C.

[0055] The refrigerant piping 8 inside each switching unit 7A includes an 11th pipe 71A that connects the pipe connecting port 45A and the pipe connecting port 48A, a 12th branch pipe 72A that connects the discharge gas pipe shutoff valve 25A, the suction gas pipe shutoff valve 26A, and the pipe connecting port 49A, a 13th pipe 73A that connects the pipe connecting port 46A and the discharge gas pipe shutoff valve 25A, and a 14th pipe 74A that connects the pipe connecting port 47A and the suction gas pipe shutoff valve 26A.

[0056] The refrigerant piping 8 inside each indoor unit 6A includes a 15th pipe 75A that connects the pipe connecting port 51A and the indoor expansion valve 22A, a 16th pipe 76A that connects the indoor expansion valve 22A and the indoor heat exchanger 21A, and a 17th pipe 77A that connects the indoor heat exchanger 21A and the pipe connecting port 52A.

[0057] The inverter circuit 18 rectifies AC power supplied from a commercial AC power source, converts rectified DC power to a frequency according to a command of the control unit 19, and outputs it to the electric motor of the compressor 2. That is, the inverter circuit 18 can control the operating frequency of the compressor 2.

[0058] The control unit 19 controls the inverter circuit 18 to control the operating frequency of the compressor 2. In addition, the control unit 19 controls the three switching valves 12A, 12B, and 12C, the plurality of discharge gas pipe shutoff valves 25A, 25B,..., and the plurality of suction gas pipe shutoff valves 26A, 26B,... based on an operation input to a remote controller (not illustrated), and switches the full cooling operation (the flow of the refrigerant indicated with the solid line arrows in Fig. 1) and the full heating operation (the flow of the refrigerant indicated with the broken line arrows in Fig. 1). Note that the control unit 19 may be distributed and disposed in the outdoor unit 5 and the indoor units 6A, 6B,.... For example, the control unit 19 provided on the outdoor unit 5 controls the inverter circuit 18 and the three switching valves 12A, 12B, and 12C, and the control unit 19 provided on the respective indoor units 6A, 6B,... controls the corresponding discharge gas pipe shutoff valves 25A, 25B,... and suction gas pipe shutoff valves 26A, 26B,....

[0059] Here, an operation state of the air conditioner 1 will be described. In any operation, the compressor 2 discharges the refrigerant to the first pipe 61 and the second branch pipe 62 and sucks the refrigerant from the eighth branch pipe 68 and the ninth pipe 69.

[0060] The flowing direction of the refrigerant in the full cooling operation is indicated with the solid line arrows in Fig. 1. The first switching valve 12A and the second switching valve 12B are switched so as to connect the discharge side of the compressor 2 to the respective outdoor heat exchangers 13 (31a and 31b). That is, the second branch pipe 62 is connected to the third pipe 63 and the fourth pipe 64. The third switching valve 12C is switched so as to shut off the connection of the discharge side of the compressor 2 and the 10th pipe 70. The discharge gas pipe shutoff valves 25A, 25B,... are fully closed. The suction gas pipe shutoff valves 26A, 26B,... are fully opened and the indoor heat exchangers 21A, 21B,... are connected to the suction side of the compressor 2.

[0061] The compressor 2 discharges a high-temperature and high-pressure gas refrigerant to the first pipe 61. The high-temperature and high-pressure gas refrigerant flows from the first pipe 61 into the oil separator 11. The oil separator 11 separates the refrigerator oil from the high-temperature and high-pressure gas refrigerant. The gas refrigerant from which the oil is separated flows out from the oil separator 11 and reaches the two outdoor heat exchangers 13 (31a and 31b) through the first switching valve 12A and the second switching valve 12B. The two outdoor heat exchangers 13 (31a and 31b) exchange the heat between the outdoor air and the gas refrigerant to condense the refrigerant, and causes the liquid refrigerant to flow out. The liquid refrigerant flowing out from the two outdoor heat exchangers 13 (31a and 31b) reaches the respective indoor heat exchangers 21A, 21B,... through the two outdoor expansion valves 15 (15a and 15b), the 11th pipes 71A, 71B,... inside the respective switching units 7A, 7B,..., and the respective indoor expansion valves 22A, 22B,.... The two outdoor expansion valves 15 (15a and 15b) adjust the flow rate of the liquid refrigerant to adjust a supercooling degree. The respective indoor expansion valves 22A, 22B,... reduce the pressure of the liquid refrigerant to attain a low-pressure gas-liquid two-phase refrigerant. The respective indoor heat exchangers 21A, 21B,... exchange the heat between the indoor air and the gas-liquid two-phase refrigerant to evaporate the refrigerant, and causes the gas refrigerant to flow out. The gas refrigerant flowing out from the respective indoor heat exchangers 21A, 21B,... is sent back to the outdoor unit 5 through the suction gas pipe shutoff valves 26A, 26B,... of the respective switching units 7A, 7B,.... At that time, the discharge gas pipe shutoff valves 25A, 25B,... are fully closed and the flow of the refrigerant in the connecting pipe 36 is blocked. The gas refrigerant that reaches the outdoor unit 5 is sucked into the accumulator 16 through the eighth branch pipe 68. The accumulator 16 separates a small amount of the liquid refrigerant mixed in the gas refrigerant. The gas refrigerant from which the liquid is separated flows out from the accumulator 16 and is sucked into the compressor 2. The sucked gas refrigerant is compressed in the compressor 2 and is discharged again from the compressor 2.

[0062] Next, the flowing direction of the refrigerant in the full heating operation is indicated with the broken line arrows in Fig 1. The refrigerant generally flows in a direction opposite to that in the full cooling operation. The third switching valve 12C is switched so as to connect the discharge side of the compressor 2 and the switching units 7A, 7B,.... That is, the second branch pipe 62 is connected to the 10th pipe 70. The discharge gas pipe shutoff valves 25A, 25B,... are fully opened to connect the discharge side of the compressor 2 and the indoor heat exchangers 21A, 21B,.... The suction gas pipe shutoff valves 26A, 26B,... are fully closed. The first switching valve 12A and the second switching valve 12B are switched so as to connect the two outdoor heat exchangers 13 (31a and 31b) to the suction side of the compressor 2.

[0063] The gas refrigerant from which the oil is separated flows out from the oil separator 11 and reaches the respective switching units 7A, 7B,... through the third switching valve 12C. The gas refrigerant that reaches the respective switching units 7A, 7B,... reaches the respective indoor heat exchangers 21A, 21B,... through the respective discharge gas pipe shutoff valves 25A, 25B,.... At that time, the suction gas pipe shutoff valves 26A, 26B,... are fully closed. The indoor heat exchangers 21A, 21B,... exchange the heat between the indoor air and the gas refrigerant to condense the refrigerant, and causes the liquid refrigerant to flow out. The liquid refrigerant flowing out from the indoor heat exchangers 21A, 21B,... reaches the two outdoor heat exchangers 13 (31a and 31b) through the respective indoor expansion valves 22A, 22B,..., the 11th pipes 71A, 71B,... inside the respective switching units 7A, 7B,..., and the two outdoor expansion valves 15 (15a and 15b). The two outdoor expansion valves 15 (15a and 15b) reduce the pressure of the liquid refrigerant to attain the low-pressure gas-liquid two-phase refrigerant. The two outdoor heat exchangers 13 (31a and 31b) exchange the heat between the outdoor air and the gas-liquid two-phase refrigerant to evaporate the refrigerant, and causes the gas refrigerant to flow out. The gas refrigerant flowing out from the two outdoor heat exchangers 13 (31a and 31b) is sucked into the accumulator 16 through the first switching valve 12A and the second switching valve 12B.

[0064] Fig. 2 is a diagram illustrating a first example of the flow of the refrigerant in a mixed cooling operation state of the air conditioner according to the present embodiment.

[0065] Fig. 2 illustrates a case of performing the cooling operation in which the two outdoor heat exchangers 13 (31a and 31b) function as condensers and the indoor heat exchangers 21A and 21B function as evaporators, and simultaneously performing the heating operation in which the indoor heat exchanger 21C functions as a condenser. The flowing direction of the refrigerant related to the cooling operation is indicated with solid line arrows in Fig. 2, and the flowing direction of the refrigerant related to the heating operation is indicated with broken line arrows in Fig. 2.

[0066] The control unit 19 controls the three switching valves 12A, 12B, and 12C, the plurality of discharge gas pipe shutoff valves 25A, 25B,..., and the plurality of suction gas pipe shutoff valves 26A, 26B,... based on the operation input to the remote controller (not illustrated), and executes the mixed cooling operation in the first example of the air conditioner 1.

[0067] In the case of the mixed cooling operation in the first example, the first switching valve 12A and the second switching valve 12B are switched so as to connect the discharge side of the compressor 2 to the two outdoor heat exchangers 13 (31a and 31b). The third switching valve 12C is switched so as to connect the discharge side of the compressor 2 and the switching units 7A, 7B,.... That is, the discharge side of the compressor 2 is connected to the two outdoor heat exchangers 13 (31a and 31b) and is also connected to the switching units 7A, 7B,... at the same time.

[0068] In the mixed cooling operation in the first example, the switching state of the third switching valve 12C is different as compared to the case of the full cooling operation, and an open / closed state of the discharge gas pipe shutoff valve 25C and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the heating operation is inverted.

[0069] The discharge gas pipe shutoff valves 25A and 25B connected to the indoor heat exchangers 21A and 21B that perform the cooling operation are fully closed, and the suction gas pipe shutoff valves 26A and 26B connected to the indoor heat exchangers 21A and 21B that perform the cooling operation are fully opened. The indoor heat exchangers 21A and 21B are connected to the suction side of the compressor 2.

[0070] The discharge gas pipe shutoff valve 25C connected to the indoor heat exchanger 21C that performs the heating operation is fully opened, and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the heating operation is fully closed. The indoor heat exchanger 21C is connected to the discharge side of the compressor 2.

[0071] The flow of the refrigerant in the mixed cooling operation in the first example will be described focusing on differences from the flow of the refrigerant in the full cooling operation. A portion of the gas refrigerant from which the oil is separated flows out from the oil separator 11 and reaches the two outdoor heat exchangers 13 (31a and 31b) through the first switching valve 12A and the second switching valve 12B, and a remaining portion of the gas refrigerant from which the oil is separated reaches the discharge gas pipe shutoff valves 25A, 25B,... of the respective switching units 7A, 7B,... through the third switching valve 12C. The fully closed discharge gas pipe shutoff valves 25A and 25B shut off the flow of the refrigerant to the indoor units 6A and 6B, and the fully opened discharge gas pipe shutoff valve 25C allows the flow of the refrigerant to the indoor unit 6C. The indoor heat exchanger 21C exchanges the heat between the indoor air and the gas refrigerant to condense the refrigerant, and causes the liquid refrigerant to flow out. The liquid refrigerant flowing out from the indoor heat exchanger 21C joins the refrigerant flowing into the other indoor heat exchangers 21A and 21B in the connecting pipe 35 through the indoor expansion valve 22C and the 11th pipe 71C inside the switching unit 7C.

[0072] Fig. 3 is a diagram illustrating a second example of the flow of the refrigerant in the mixed cooling operation state of the air conditioner according to the present embodiment.

[0073] Fig. 3 illustrates a case of performing the cooling operation in which the auxiliary heat exchanger 31b functions as a condenser and the indoor heat exchangers 21A and 21B function as evaporators, and simultaneously performing the heating operation in which the indoor heat exchanger 21C functions as a condenser. The flowing direction of the refrigerant related to the cooling operation is indicated with solid line arrows in Fig. 3, and the flowing direction of the refrigerant related to the heating operation is indicated with broken line arrows in Fig. 3.

[0074] The control unit 19 controls the three switching valves 12A, 12B, and 12C, the plurality of discharge gas pipe shutoff valves 25A, 25B,..., and the plurality of suction gas pipe shutoff valves 26A, 26B,... based on the operation input to the remote controller (not illustrated), and executes the mixed cooling operation in the second example of the air conditioner 1.

[0075] In the case of the mixed cooling operation in the second example, the first switching valve 12A is switched so as to shut off the main heat exchanger 31a from the discharge side of the compressor 2 and the second switching valve 12B is switched so as to connect the discharge side of the compressor 2 to the auxiliary heat exchanger 31b.

[0076] The third switching valve 12C is switched so as to connect the discharge side of the compressor 2 and the plurality of switching units 7A, 7B,.... That is, the discharge side of the compressor 2 is connected to the auxiliary heat exchanger 31b and is also connected to the switching units 7A, 7B,... at the same time.

[0077] In the mixed cooling operation in the second example, the switching state of the first switching valve 12A and the third switching valve 12C is different as compared to the case of the full cooling operation, the open / closed state of the first outdoor expansion valve 15a is inverted, and the open / closed state of the discharge gas pipe shutoff valve 25C and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the heating operation is inverted.

[0078] The discharge gas pipe shutoff valves 25A and 25B connected to the indoor heat exchangers 21A and 21B that perform the cooling operation are fully closed, and the suction gas pipe shutoff valves 26A and 26B connected to the indoor heat exchangers 21A and 21B that perform the cooling operation are fully opened. The indoor heat exchangers 21A and 21B are connected to the suction side of the compressor 2.

[0079] The discharge gas pipe shutoff valve 25C connected to the indoor heat exchanger 21C that performs the heating operation is fully opened, and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the heating operation is fully closed. The indoor heat exchanger 21C is connected to the discharge side of the compressor 2.

[0080] In the mixed cooling operation in the second example, the refrigerant flows generally the same as that in the mixed cooling operation in the first example, however, the first switching valve 12A and the first outdoor expansion valve 15a shut off the flow of the refrigerant to the main heat exchanger 31a.

[0081] Such a mixed cooling operation in the second example is an operation mode advantageous when an outdoor air temperature is close to a target temperature, without requiring refrigerating capacity as compared to the mixed cooling operation in the first example.

[0082] Note that the outdoor unit 5 of the air conditioner 1 that does not perform the mixed cooling operation in the second example and performs the mixed cooling operation in the first example may include at least one outdoor heat exchanger 13 and at least one outdoor expansion valve 15, and may not include the second switching valve 12B connected to the auxiliary heat exchanger 31b.

[0083] Fig. 4 is a diagram illustrating an example of the flow of the refrigerant in a mixed heating operation state of the air conditioner according to the present embodiment.

[0084] Fig. 4 illustrates a case of the heating operation in which the two outdoor heat exchangers 13 (31a and 31b) function as evaporators and the indoor heat exchangers 21A and 21B function as condensers, and the cooling operation in which the indoor heat exchanger 21C functions as an evaporator. The flowing direction of the refrigerant related to the cooling operation is indicated with solid line arrows in Fig. 4, and the flowing direction of the refrigerant related to the heating operation is indicated with broken line arrows in Fig. 4.

[0085] The control unit 19 controls the three switching valves 12A, 12B, and 12C, the plurality of discharge gas pipe shutoff valves 25A, 25B,..., and the plurality of suction gas pipe shutoff valves 26A, 26B,... based on the operation input to the remote controller (not illustrated), and executes the mixed heating operation of the air conditioner 1.

[0086] The switching state of the three switching valves 12A, 12B, and 12C in the mixed heating operation is the same as the switching state of the three switching valves 12A, 12B, and 12C in the full heating operation.

[0087] In the mixed heating operation, the open / closed state of the discharge gas pipe shutoff valve 25C and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the cooling operation is inverted as compared to the case of the full heating operation.

[0088] The discharge gas pipe shutoff valves 25A and 25B connected to the indoor heat exchangers 21A and 21B that perform the heating operation are fully opened, and the suction gas pipe shutoff valves 26A and 26B connected to the indoor heat exchangers 21A and 21B that perform the heating operation are fully closed. That is, the indoor heat exchangers 21A and 21B are connected to the discharge side of the compressor 2.

[0089] The discharge gas pipe shutoff valve 25C connected to the indoor heat exchanger 21C that performs the cooling operation is fully closed, and the suction gas pipe shutoff valve 26C connected to the indoor heat exchanger 21C that performs the cooling operation is fully opened. That is, the indoor heat exchanger 21C is connected to the suction side of the compressor 2.

[0090] In the mixed heating operation, the refrigerant flows generally the same as that in the full heating operation, however, the liquid refrigerant flowing out from the indoor heat exchangers 21A and 21B is branched in the connecting pipe 35, is subjected to pressure reduction in the indoor expansion valve 22C, and reaches the indoor heat exchanger 21C. The indoor heat exchanger 21C exchanges the heat between the indoor air and the gas-liquid two-phase refrigerant to evaporate the refrigerant, and causes the gas refrigerant to flow out. The gas refrigerant flowing out from the indoor heat exchanger 21C is sucked into the accumulator 16 through the suction gas pipe shutoff valve 26C.

[0091] Next, the outdoor unit 5 will be described in detail.

[0092] Fig. 5 is an exploded perspective view of a first example of the outdoor unit according to the embodiment of the present invention.

[0093] As illustrated in Fig. 5, the outdoor unit 5 according to the present embodiment includes a housing 81. The housing 81 is a box body in a rectangular parallelepiped shape that is long up and down. The housing 81 includes a bottom plate 82 that is rectangular in a planar view, four columns 83 rising from the bottom plate 82, a detachable rectangular front plate 85 that covers a front of the housing 81, a rectangular front upper plate 86 that covers an upper portion of the front of the housing 81, two rectangular side face upper plates 87 that cover upper portions of left and right side faces of the housing 81, a rectangular side face lower plate 88 that covers a lower front portion of the right side face of the housing 81, a rectangular back plate 89 that covers an upper portion of a back of the housing 81, and a fan guard 90 that covers a top surface of the housing 81.

[0094] The four columns 83 extend upwards from vicinities of four respective corners of the bottom plate 82.

[0095] Lower portions of the left and right side faces of the housing 81 and a lower portion of the back of the housing 81 are largely opened. This opening is a suction port that takes the outdoor air from an outer side of the outdoor unit 5 to an inner side by drive of the outdoor fan 17. The two outdoor heat exchangers 13 are disposed at the opening.

[0096] The housing 81 houses the compressor 2, the oil separator 11, the three switching valves 12A, 12B, and 12C, the two outdoor heat exchangers 13, the two outdoor expansion valves 15, the accumulator 16, and the refrigerant piping 8 that connects them. In addition, the housing 81 includes an electrical component box 91 that houses the control unit 19.

[0097] The outdoor fan 17 is disposed at a top portion of the housing 81. The outdoor fan 17 sucks the outdoor air from the suction port where the two outdoor heat exchangers 13 are disposed, and discharges it from a bell mouth 92. The outdoor fan 17 blows out the air toward above the outdoor unit 5. The outdoor fan 17 is supported on a fan base 93 supported by the four columns 83 of the housing 81. The fan base 93 supports the outdoor fan 17 and the bell mouth 92. The bell mouth 92 is an outlet of the outdoor fan 17, and rectifies the heat-exchanged outdoor air flowing out from the outdoor fan 17. The bell mouth 92 is surrounded on all four sides, front, back, left, and right, by the front upper plate 86, the two side face upper plates 87, and the back plate 89.

[0098] Fig. 6 is a front view of a first example of the outdoor unit according to the embodiment of the present invention.

[0099] Fig. 7 is a schematic front view of the first example of the outdoor unit according to the embodiment of the present invention.

[0100] Fig. 8 is a plan view of the first example of the outdoor unit according to the embodiment of the present invention.

[0101] Fig. 6 to Fig. 8 illustrate the bottom plate 82, the two outdoor heat exchangers 13, the three switching valves 12A, 12B, and 12C, the oil separator 11, the accumulator 16, and the refrigerant piping 8 of the outdoor unit 5, and the other main components are omitted.

[0102] When the front plate 85 as a detachable side face is detached from the housing 81, it is possible to directly view an inside of the outdoor unit 5 in a direction of an outline solid line arrow extending from the front to the back of the housing 81, which is illustrated in Fig. 8. In this state, equipment inside the outdoor unit 5 is maintained, replaced, or repaired.

[0103] As illustrated in Fig. 6 to Fig. 8, one of the outdoor heat exchangers 13 of the outdoor unit 5 according to the present embodiment is the main heat exchanger 31a as the first outdoor heat exchanger, and the other outdoor heat exchanger 13 is the auxiliary heat exchanger 31b as the second outdoor heat exchanger. The main heat exchanger 31a is disposed above the auxiliary heat exchanger 31b. The main heat exchanger 31a is preferably disposed right above the auxiliary heat exchanger 31b.

[0104] The plurality of paths 28 of the main heat exchanger 31a and the auxiliary heat exchanger 31b extend in a horizontal direction of the housing 81 to cause the refrigerant to flow. The plurality of fins of the main heat exchanger 31a and the auxiliary heat exchanger 31b extend in an up-down direction of the housing 81 orthogonally to the plurality of paths 28.

[0105] The main heat exchanger 31a and the auxiliary heat exchanger 31b have end faces 101 and 102 arranged on one plane. These end faces 101 and 102 face the horizontal direction of the housing 81.

[0106] The plurality of fins of the main heat exchanger 31a and the plurality of fins of the auxiliary heat exchanger 31b are divided. The end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b are preferably disposed practically on a single plane.

[0107] The main heat exchanger 31a and the auxiliary heat exchanger 31b may be obtained by dividing an integrated heat exchanger by a broken line D indicated in Fig. 6. For example, the main heat exchanger 31a is an upper half portion of the integrated heat exchanger, and the auxiliary heat exchanger 31b is a lower half portion of the integrated heat exchanger. The plurality of fins of the main heat exchanger 31a and the plurality of fins of the auxiliary heat exchanger 31b continue in series in both heat exchangers and spread over the both heat exchangers 31a and 31b. The integrated heat exchanger that includes the main heat exchanger 31a and the auxiliary heat exchanger 31b and share the plurality of fins is excellent in a manufacturing cost compared to the main heat exchanger 31a and the auxiliary heat exchanger 31b that are divided into two. The plurality of paths 28 of the main heat exchanger 31a pass through an upper half portion of the plurality of fins, and the plurality of paths 28 of the auxiliary heat exchanger 31b pass through a lower half portion of the plurality of fins. In this case, one plane on which the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b are arranged is a single end face of the integrated heat exchanger. In other words, the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b form one continuous plane. This plane is one of two main surfaces of the fin positioned at one end of the integrated heat exchanger, and faces the horizontal direction of the housing 81 similarly to the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b.

[0108] In addition, the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b face an inner surface of the detachable front plate 85. That is, the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b face the front of the housing 81.

[0109] Each path 28 has a refrigerant inlet and a refrigerant outlet disposed on the end face 101 of the main heat exchanger 31a or the end face 102 of the auxiliary heat exchanger 31b arranged on one plane. In other words, inlets and outlets of the plurality of paths 28 of the main heat exchanger 31a are disposed on the end face 101 of the main heat exchanger 31a, and inlets and outlets of the plurality of paths 28 of the auxiliary heat exchanger 31b are disposed on the end face 102 of the auxiliary heat exchanger 31b.

[0110] The accumulator 16 and the oil separator 11 are disposed so as to face an inner surface of the outdoor heat exchanger 13. The accumulator 16 and the oil separator 11 face an inner surface of the auxiliary heat exchanger 31b positioned below.

[0111] The three switching valves 12A, 12B, and 12C are disposed above the accumulator 16 and the oil separator 11. Further, the three switching valves 12A, 12B, and 12C are closer to the front of the housing 81 than the accumulator 16 and the oil separator 11 are.

[0112] The 10th pipe 70 is provided with a gas valve 105 that shuts off outflow of the refrigerant from the outdoor unit 5 to the outside at the time of factory shipping and at the time of installation work. The gas valve 105 is a shutoff valve that can be manually opened and closed, and is provided with an operation unit for a manual operation. The gas valve 105 is disposed such that the operation unit faces the inner surface of the front plate 85. In other words, the gas valve 105 is disposed so as to be easily operated to be opened and closed from the front side of the housing 81 in a state where the front plate 85 is detached from the housing 81.

[0113] Fig. 9 is a perspective view of the three switching valves of the outdoor unit according to the embodiment of the present invention.

[0114] An outline solid line arrow illustrated in Fig. 9 indicates a direction from the front to the back of the housing 81. The end faces 101 and 102 of the two outdoor heat exchangers 13 are disposed on a right side of the second switching valve 12B when viewed in the direction indicated by the outline solid line arrow.

[0115] As illustrated in Fig. 9 in addition to Fig. 6 to Fig. 8, the first switching valve 12A of the outdoor unit 5 according to the present embodiment is closer to the end face 101 of the main heat exchanger 31a than the third switching valve 12C is, and the second switching valve 12B is closer to the end face 101 of the main heat exchanger 31a than the first switching valve 12A is. In other words, the three switching valves 12A, 12B, and 12C are arranged in an order of the second switching valve 12B, the first switching valve 12A, and the third switching valve 12C from the side closer to the end face 101 of the main heat exchanger 31a.

[0116] Further, the three switching valves 12A, 12B, and 12C are closer to the main heat exchanger 31a than to the auxiliary heat exchanger 31b. That is, the switching valves 12A, 12B, and 12C are arranged in the order of the second switching valve 12B, the first switching valve 12A, and the third switching valve 12C from the side closer to the main heat exchanger 31a.

[0117] In addition, the three switching valves 12A, 12B, and 12C are disposed on an outer side of a projection region A1 in a normal direction of the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b. In other words, the switching valves 12A, 12B, and 12C are disposed on the outer side of the projection region A1 in the normal direction of the end face of the outdoor heat exchanger 13. The projection region A1 faces the front of the housing 81.

[0118] The three switching valves 12A, 12B, and 12C are all four-way valves, and all have the same configuration. Hereinafter, the representative first switching valve 12A will be described.

[0119] The first switching valve 12A includes a valve body 111a, a valve box 112a that houses the valve body 111a movably in the horizontal direction, a first connecting port 115a connectable to a condenser at the time of the cooling operation, a second connecting port 116a connectable to an evaporator at the time of the cooling operation, a third connecting port 117a that hangs down below the valve box 112a and is connected to the discharge side of the compressor 2, and a fourth connecting port 118a that rises above the valve box 112a and is connected to the suction side of the compressor 2.

[0120] In addition, the first switching valve 12A includes a pilot solenoid valve 119a for moving the valve body 111a. The pilot solenoid valve 119a is connected to the inside of the valve box 112a through a plurality of small tubes 121a. The pilot solenoid valve 119a connects the first connecting port 115a and the third connecting port 117a of the first switching valve 12A and connects the second connecting port 116a and the fourth connecting port 118a of the first switching valve 12A in a state where a coil (not illustrated) is not energized. Further, the pilot solenoid valve 119a connects the first connecting port 115a and the fourth connecting port 118a of the first switching valve 12A and connects the second connecting port 116a and the third connecting port 117a of the first switching valve 12A in a state where the coil is energized.

[0121] The first connecting port 115a, the second connecting port 116a, and the fourth connecting port 118a are lined up in parallel in a longitudinal direction of the valve box 112a.

[0122] A first connecting port 115b of the second switching valve 12B is connected to the fourth pipe 64 that continues to the outdoor heat exchanger 13 (the auxiliary heat exchanger 31b).

[0123] A second connecting port 116b of the second switching valve 12B is closed by a sealing plug 125.

[0124] The first connecting port 115a of the first switching valve 12A is connected to the third pipe 63 that continues to the outdoor heat exchanger 13 (the main heat exchanger 31a).

[0125] The second connecting port 116a of the first switching valve 12A is closed by the sealing plug 125.

[0126] The first connecting port 115c of the third switching valve 12C is closed by the sealing plug 125.

[0127] The second connecting port 116c of the third switching valve 12C is connected to the 10th pipe 70 that continues to the discharge gas pipe shutoff valves 25A, 25B,... of the switching units 7A, 7B,....

[0128] The respective third connecting ports 117a, 117b, and 117c of the three switching valves 12A, 12B, and 12C are connected to the second branch pipe 62 that continues to the discharge side of the compressor 2 through the oil separator 11.

[0129] The respective fourth connecting ports 118a, 118b, and 118c of the three switching valves 12A, 12B, and 12C are connected to the eighth branch pipe 68 that continues to the suction side of the compressor 2 through the accumulator 16.

[0130] The respective switching valves 12A, 12B, and 12C have center lines of long cylindrical valve boxes 112a, 112b, and 112c in the horizontal direction. In addition, the respective switching valves 12A, 12B, and 12C are disposed such that pilot solenoid valves 119a, 119b, and 119c face the inner surface of the detachable front plate 85. In other words, all of the pilot solenoid valves 119a, 119b, and 119c face the inner surface of the front plate 85. In other words, all of the pilot solenoid valves 119a, 119b, and 119c are installed such that the coil can be easily attached and detached in the state where the front plate 85 is detached from the housing 81.

[0131] Further, the three switching valves 12A, 12B, and 12C are disposed practically at a same height position of the housing 81. A difference in height of these switching valves 12A, 12B, and 12C is preferably within a size of the switching valves 12A, 12B, and 12C before the refrigerant piping 8 is connected.

[0132] Then, the fourth pipe 64 extending from the second switching valve 12B to the auxiliary heat exchanger 31b is installed so as to hang down in the projection region A1 toward the auxiliary heat exchanger 31b.

[0133] The third pipe 63 extending from the first switching valve 12A to the main heat exchanger 31a is installed so as to cross above the second switching valve 12B toward the main heat exchanger 31a.

[0134] Functions of the three switching valves 12A, 12B, and 12C can be satisfied by three-way valves rather than four-way valves. However, the three switching valves 12A, 12B, and 12C according to the present embodiment and the four-way valve of an air conditioner of a different model are made common by applying the four-way valves that switch the cooling operation and the heating operation alone, such as the one disclosed in Japanese Patent Laid-Open No. 2017-180882, to the three switching valves 12A, 12B, and 12C.

[0135] Fig. 10 is a schematic front view of a first comparative example of the outdoor unit.

[0136] As illustrated in Fig. 10, an outdoor unit 201A of the first comparative example includes the three switching valves 12A, 12B, and 12C arranged in the order of the first switching valve 12A, the second switching valve 12B, and the third switching valve 12C from the side closer to the end face 101 of the main heat exchanger 31a.

[0137] In the first comparative example, the third pipe 63 extending from the first switching valve 12A to the main heat exchanger 31a is installed in a shortest route toward the main heat exchanger 31a.

[0138] However, the fourth pipe 64 extending from the second switching valve 12B to the auxiliary heat exchanger 31b makes a detour between the second switching valve 12B and the third switching valve 12C and below the second switching valve 12B, and is installed toward the auxiliary heat exchanger 31b. Such an installation route of the fourth pipe 64 in the first comparative example can be said to be a longer route than the installation route of the fourth pipe 64 of the outdoor unit 5 according to the present embodiment.

[0139] The installation route of the refrigerant piping 8 of the outdoor unit 5 according to the present embodiment, that is illustrated in Fig. 7, is excellent in total extension of the refrigerant piping 8 and simplicity of the installation route as compared to the installation route of the refrigerant piping 8 in the first comparative example.

[0140] Fig. 11 is a schematic front view of a second comparative example of the outdoor unit.

[0141] As illustrated in Fig. 11, an outdoor unit 201B of the second comparative example includes the three switching valves 12A, 12B, and 12C arranged in the order of the first switching valve 12A, the second switching valve 12B, and the third switching valve 12C from the side closer to the end face 101 of the main heat exchanger 31a.

[0142] In the second comparative example, the third pipe 63 extending from the first switching valve 12A to the main heat exchanger 31a is installed in the shortest route toward the main heat exchanger 31a.

[0143] However, the fourth pipe 64 extending from the second switching valve 12B to the auxiliary heat exchanger 31b makes a detour above the first switching valve 12A, and is installed toward the auxiliary heat exchanger 31b so as to hang down in the projection region A1. Such an installation route of the fourth pipe 64 in the second comparative example can be said to be a longer route than the installation route of the fourth pipe 64 of the outdoor unit 5 according to the present embodiment.

[0144] In addition, the second comparative example requires room between the first switching valve 12A closest to the end face 101 of the main heat exchanger 31a and the end face 101 of the main heat exchanger 31a in order to avoid three-dimensional interference of the third pipe 63, the fourth pipe 64, and the header 29 of the main heat exchanger 31a. This room increases a width dimension of the outdoor unit 201B and obstructs miniaturization of the outdoor unit 201B.

[0145] The installation route of the refrigerant piping 8 of the outdoor unit 5 according to the present embodiment, that is illustrated in Fig. 7, is excellent in the total extension of the refrigerant piping 8, the simplicity of the installation route, and miniaturization of the outdoor unit 5 as compared to the installation route of the refrigerant piping 8 in the second comparative example.

[0146] Next, an outdoor unit 5A of a second example according to the present embodiment will be described.

[0147] Fig. 12 is a front view of the second example of the outdoor unit according to the embodiment of the present invention.

[0148] Fig. 13 is a schematic front view of the second example of the outdoor unit according to the embodiment of the present invention.

[0149] Fig. 14 is a plan view of the second example of the outdoor unit according to the embodiment of the present invention.

[0150] As illustrated in Fig. 12 to Fig. 14, the outdoor unit 5A according to the present embodiment is provided with four outdoor heat exchangers 13A. The four outdoor heat exchangers 13A include two main heat exchangers 31a and two auxiliary heat exchangers 31b. The two main heat exchangers 31a are connected in parallel between the first switching valve 12A and the first outdoor expansion valve 15a. The two auxiliary heat exchangers 31b are connected in parallel between the second switching valve 12B and the second outdoor expansion valve 15b.

[0151] The number of the second outdoor expansion valves 15b may be the same as the number of the auxiliary heat exchangers 31b. In this case, one auxiliary heat exchanger 31b and one second outdoor expansion valve 15b are connected in series, the other auxiliary heat exchanger 31b and the other second outdoor expansion valve 15b are connected in series, and those two series systems are connected in parallel.

[0152] Fig. 12 to Fig. 14 illustrate the bottom plate 82, the four outdoor heat exchangers 13A, the three switching valves 12A, 12B, and 12C, the oil separator 11, the accumulator 16, and the refrigerant piping 8 of the outdoor unit 5A, and the other main components are omitted.

[0153] When the front plate 85 as the detachable side face is detached from the housing 81, it is possible to directly view the inside of the housing 81 in the direction of an outline solid line arrow extending from the front to the back of the housing 81, which is illustrated in Fig. 14. In this state, equipment inside the outdoor unit 5A is maintained, replaced, or repaired.

[0154] With a center plane that extends in a front-back direction of the housing 81 and bisects the housing 81 to left and right as a reference, the four outdoor heat exchangers 13A draw a practically bilaterally symmetrical shape. The two outdoor heat exchangers 13A on the right side spread on a right half of the back of the housing 81 and a right side face of the housing 81 from one end face 131 positioned in the right side vicinity of the center plane CP of the housing 81 to the back of the housing 81. The two outdoor heat exchangers 13A on the left side spread on a left half of the back of the housing 81 and a left side face of the housing 81 from one end face 132 positioned in the left side vicinity of the center plane CP of the housing 81 to the back of the housing 81.

[0155] The left and right outdoor heat exchangers 13A all have the same configuration. Hereinafter, the representative right outdoor heat exchangers 13A will be described. The configurations same as those of the outdoor heat exchanger 13 of the outdoor unit 5 in the first example are denoted by same reference signs and redundant description will be omitted.

[0156] One of the right outdoor heat exchangers 13A is the main heat exchanger 31a as the first outdoor heat exchanger, and the other right outdoor heat exchanger 13A is the auxiliary heat exchanger 31b as the second outdoor heat exchanger. The main heat exchanger 31a is disposed above the auxiliary heat exchanger 31b. The main heat exchanger 31a is preferably disposed right above the auxiliary heat exchanger 31b.

[0157] Then, the end face 101 of the right main heat exchanger 31a and the end face 101 of the left main heat exchanger 31a are disposed in mirror-image symmetry. In addition, the end face 102 of the right auxiliary heat exchanger 31b and the end face 102 of the left auxiliary heat exchanger 31b are disposed in the mirror-image symmetry.

[0158] The oil separator 11 is disposed so as to face the inner surface of the left outdoor heat exchanger 13A. The oil separator 11 faces the inner surface of the left auxiliary heat exchanger 31b.

[0159] The accumulator 16 is disposed so as to face the inner surface of the right outdoor heat exchanger 13A. The accumulator 16 faces the inner surface of the right auxiliary heat exchanger 31b.

[0160] The three switching valves 12A, 12B, and 12C are disposed on the right side of the housing 81 where the accumulator 16 is disposed, that is, on the right side of the center plane CP.

[0161] Note that arrangement of the equipment such as the four outdoor heat exchangers 13A, the three switching valves 12A, 12B, and 12C, the oil separator 11, the accumulator 16, and the refrigerant piping 8 inside the outdoor unit 5A may be left / right inverted with respect to the center plane CP of the housing 81.

[0162] Fig. 15 is a perspective view of the three switching valves of the outdoor unit according to the embodiment of the present invention.

[0163] An outline solid line arrow illustrated in Fig. 15 indicates the direction from the front to the back of the housing 81. The end faces 131 and 132 of the two outdoor heat exchangers 13A are disposed on the left side of the second switching valve 12B when viewed in the direction indicated by the outline solid line arrow.

[0164] As illustrated in Fig. 15 in addition to Fig. 12 to Fig. 14, the first switching valve 12A of the outdoor unit 5A according to the present embodiment is closer to the end face 101 of the two main heat exchangers 31a than the third switching valve 12C is, and the second switching valve 12B is closer to the end face 101 of the two main heat exchangers 31a than the first switching valve 12A is. In other words, the three switching valves 12A, 12B, and 12C are arranged in the order of the second switching valve 12B, the first switching valve 12A, and the third switching valve 12C from the side closer to the end face 101 of the two main heat exchangers 31a.

[0165] Further, the three switching valves 12A, 12B, and 12C are closer to the two main heat exchangers 31a than to the two auxiliary heat exchangers 31b. That is, the switching valves 12A, 12B, and 12C are arranged in the order of the second switching valve 12B, the first switching valve 12A, and the third switching valve 12C from the side closer to the two main heat exchangers 31a.

[0166] In addition, the three switching valves 12A, 12B, and 12C are disposed on the outer side of a projection region A2 in a front direction of the housing 81, including the end face 101 of the two main heat exchangers 31a and the end face 102 of the two auxiliary heat exchangers 31b. In other words, the switching valves 12A, 12B, and 12C are disposed on the outer side of the projection region A2 of the end face of the four outdoor heat exchangers 13A.

[0167] The fourth pipe 64 extending from the second switching valve 12B to the two left and right auxiliary heat exchangers 31b is installed so as to hang down in the projection region A2 toward the auxiliary heat exchangers 31b.

[0168] The third pipe 63 extending from the first switching valve 12A to the two left and right main heat exchangers 31a is installed so as to cross above the second switching valve 12B toward the main heat exchangers 31a.

[0169] Fig. 16 is a schematic front view of a third comparative example of the outdoor unit.

[0170] As illustrated in Fig. 16, an outdoor unit 201C of the third comparative example includes the three switching valves 12A, 12B, and 12C arranged in the order of the first switching valve 12A, the second switching valve 12B, and the third switching valve 12C from the side closer to the end face 101 of the two main heat exchangers 31a.

[0171] In the third comparative example, the third pipe 63 extending from the first switching valve 12A to the two main heat exchangers 31a is installed in the shortest route toward the main heat exchangers 31a.

[0172] However, the fourth pipe 64 extending from the second switching valve 12B to the two auxiliary heat exchangers 31b makes a detour on the left side of the end face 101 of the two main heat exchangers 31a and is installed toward the two auxiliary heat exchangers 31b. Such an installation route of the fourth pipe 64 in the third comparative example can be said to be a longer route than the installation route of the fourth pipe 64 of the outdoor unit 5A according to the present embodiment.

[0173] The installation route of the refrigerant piping 8 of the outdoor unit 5A according to the present embodiment, which is illustrated in Fig. 15, is excellent in the total extension of the refrigerant piping 8 and the simplicity of the installation route as compared to the installation route of the refrigerant piping 8 in the third comparative example.

[0174] Fig. 17 is a schematic front view of a fourth comparative example of the outdoor unit.

[0175] As illustrated in Fig. 17, an outdoor unit 201D of the fourth comparative example includes the three switching valves 12A, 12B, and 12C arranged in the order of the first switching valve 12A, the second switching valve 12B, and the third switching valve 12C from the side closer to the end face 101 of the two main heat exchangers 31a.

[0176] In the fourth comparative example, the third pipe 63 extending from the first switching valve 12A to the main heat exchangers 31a is installed in the shortest route toward the main heat exchangers 31a.

[0177] However, the fourth pipe 64 extending from the second switching valve 12B to the two auxiliary heat exchangers 31b makes a detour above the first switching valve 12A and is installed so as to hang down in the projection region A2 toward the two auxiliary heat exchangers 31b. Such an installation route of the fourth pipe 64 in the fourth comparative example can be said to be a longer route than the installation route of the fourth pipe 64 of the outdoor unit 5A according to the present embodiment.

[0178] In addition, the fourth comparative example requires room between the first switching valve 12A closest to the end face 101 of the two main heat exchangers 31a and the end face 101 of the two main heat exchangers 31a in order to avoid the three-dimensional interference of the third pipe 63, the fourth pipe 64, and the headers 29 of the two main heat exchangers 31a. This room increases a width dimension of the outdoor unit 201D and obstructs miniaturization of the outdoor unit 201D.

[0179] The installation route of the refrigerant piping 8 of the outdoor unit 5A according to the present embodiment, that is illustrated in Fig. 15, is excellent in the total extension of the refrigerant piping 8, the simplicity of the installation route, and the miniaturization of the outdoor unit 5A as compared to the installation route of the refrigerant piping 8 in the fourth comparative example.

[0180] Fig. 18 is a block diagram of a second form of the air conditioner according to the embodiment of the present invention.

[0181] As illustrated in Fig. 18, the air conditioner 1 according to the present embodiment may not include the plurality of switching units 7A, 7B,.... The connecting pipe 35 connects one pipe connecting port 41 of the outdoor unit 5 or 5A and the respective pipe connecting ports 51A, 51B,... of the plurality of indoor units 6A, 6B,.... The connecting pipe 36 connects one pipe connecting port 42 of the outdoor unit 5 or 5A and the respective pipe connecting ports 52A, 52B,... of the plurality of indoor units 6A, 6B,.... The connecting pipe 37 is not needed, and the pipe connecting port 43 is maintained in a closed state. The third switching valve 12C of the outdoor unit 5 or 5A is switched such that the refrigerant is sucked from the plurality of indoor units 6A, 6B,... to the compressor 2 during the cooling operation, and the refrigerant is sent from the compressor 2 to the plurality of indoor units 6A, 6B,... during the heating operation.

[0182] The air conditioner 1 may include a sealing plug 135 that closes the pipe connecting port 43 of the outdoor unit 5 or 5A.

[0183] That is, the air conditioner 1 can be utilized in the second form in which the pipe connecting port 43 is closed, the plurality of switching units 7A, 7B,... and the connecting pipe 37 are not provided, and the outdoor unit 5 or 5A and the plurality of indoor units 6A, 6B,... are directly connected by using the connecting pipes 35 and 36. The air conditioner 1 in the second form performs the cooling operation by circulating the refrigerant in a direction indicated with solid line arrows in Fig. 18, and performs heating by circulating the refrigerant in a direction indicated with broken line arrows in Fig. 18.

[0184] Thus, when the pipe connecting port 43 of the outdoor unit 5 or 5A is closed, the air conditioner 1 functions as a multi-type air conditioner that performs the full cooling operation or the full heating operation.

[0185] Now, the eighth branch pipe 68 not connected to the connecting pipe 37 is a pipe that connects the third switching valve 12C and the accumulator 16 disposed on the suction side of the compressor 2 and also connects the pipe connecting port 43 and the accumulator 16, and includes a branch portion where three pipes to the third switching valve 12C, the accumulator 16, and the pipe connecting port 43 intersect. A pipe between the branch portion and the pipe connecting port 43 becomes a so-called blind alley. There is a risk that the refrigerant and the refrigerator oil mixed in the refrigerant stay in the blind alley. In order to recover the refrigerant and the refrigerator oil staying in the blind alley of the eighth branch pipe 68, the air conditioner 1 may include a recovery pipe 136 indicated with a two-dot chain line, that is connected to the pipe connecting port 43 and the suction side of the accumulator 16.

[0186] As described above, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes the first switching valve 12A closer to the end face 101 of the main heat exchanger 31a than the third switching valve 12C is, and the second switching valve 12B closer to the end face 101 of the main heat exchanger 31a than the first switching valve 12A is. Consequently, the outdoor unit 5 or 5A is excellent in the total extension of the refrigerant piping 8, the simplicity of the installation route, and the miniaturization of the outdoor unit 5.

[0187] In addition, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes the three switching valves 12A, 12B, and 12C disposed on the outer side of the projection region A1 or A2 of the end face of the plurality of outdoor heat exchangers 13 or 13A including the projection region of the end face 101 of the main heat exchanger 31a. Consequently, the outdoor unit 5 or 5A makes it easy to view and approach the paths 28 of the plurality of outdoor heat exchangers 13 or 13A, and is excellent in workability to the paths 28.

[0188] Further, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment may include a heat exchanger for which the main heat exchanger 31a and the auxiliary heat exchanger 31b are integrated. This heat exchanger has the end face 101 of the main heat exchanger 31a and the end face 102 of the auxiliary heat exchanger 31b as one continuous plane. Consequently, the outdoor unit 5 or 5A makes it easier to view and approach the paths 28 of the plurality of outdoor heat exchangers 13 and 13A, and is more excellent in the workability to the paths 28.

[0189] In addition, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes three four-way valves as the three switching valves 12A, 12B, and 12C. The three switching valves 12A, 12B, and 12C according to the present embodiment and the four-way valve of an air conditioner of a different model are made common by appropriately closing connecting ports of the four-way valves and utilizing them.

[0190] Further, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes three four-way valves as the three switching valves 12A, 12B, and 12C. Then, the three four-way valves respectively provided with the valve boxes 112a, 112b, and 112c that house the valve bodies 111a, 111b, and 111c movably in the horizontal direction, the third connecting ports 117a, 117b, and 117c that hang down below the valve boxes 112a, 112b, and 112c and are connected to the discharge side of the compressor 2, and the fourth connecting ports 118a, 118b, and 118c that rise above the valve boxes 112a, 112b, and 112c and are connected to the suction side of the compressor 2. Consequently, the outdoor unit 5 or 5A is excellent in the total extension of the refrigerant piping 8 between the compressor 2 and the three switching valves 12A, 12B, and 12C, the simplicity of the installation route, and the miniaturization of the outdoor unit 5.

[0191] Additionally, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes the housing 81 provided with the detachable front plate 85. Then, the three switching valves 12A, 12B, and 12C include the pilot solenoid valves 119a, 119b, and 119c facing the inner surface of the front plate 85. Consequently, the outdoor unit 5 or 5A makes it easy to view and approach the coils put on the pilot solenoid valves 119a, 119b, and 119c of the three switching valves 12A, 12B, and 12C, and is excellent in workability to the coils.

[0192] Further, the outdoor unit 5 or 5A of the air conditioner 1 according to the present embodiment includes the three switching valves 12A, 12B, and 12C disposed above the accumulator 16. That is, in the state where the outdoor unit 5 or 5A is installed, the three switching valves 12A, 12B, and 12C can be disposed at a height of about several tens of centimeters from an installation surface of the outdoor unit 5 or 5A. Consequently, the three switching valves 12A, 12B, and 12C of the outdoor unit 5 or 5A are disposed at a height where work is easy compared to the case of being close to the bottom plate 82 of the housing 81.

[0193] Then, the air conditioner 1 according to the present embodiment includes the outdoor unit 5 or 5A, the plurality of indoor units 6A, 6B,..., and the plurality of switching units 7A, 7B,.... The air conditioner 1 including the plurality of switching units 7A, 7B,... can cause the flowing direction of the refrigerant flowing to the plurality of indoor units 6A, 6B,... to be different from each other to mix the indoor units 6A, 6B,... that perform the cooling operation and the indoor units 6A, 6B,... that perform the heating operation. The air conditioner 1 according to the present embodiment may include the outdoor unit 5 or 5A and the plurality of indoor units 6A, 6B,... and have one of branches of the third switching valve 12C closed. The air conditioner 1 which does not include the plurality of switching units 7A, 7B,... and has one of the branches of the third switching valve 12C closed unifies the flowing direction of the refrigerant flowing to the plurality of indoor units 6A, 6B,... to cause all of the indoor units 6A, 6B,... to perform the cooling operation or the heating operation. That is, the air conditioner 1 can function as a heat-recovery multi-type air conditioner by selecting the plurality of switching units 7A, 7B,..., and function as a multi-type air conditioner by selecting non-application of the plurality of switching units 7A, 7B,....

[0194] Therefore, according to the outdoor unit 5 or 5A of the air conditioner 1 and the air conditioner 1 according to the present embodiment, the connection of the plurality of outdoor heat exchangers 13 or 13A, the discharge side of the compressor 2 and the suction side of the compressor 2 can be switched and the installation route of the refrigerant piping 8 is excellent.

[0195] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.Reference Signs List

[0196] 1...air conditioner, 2...compressor, 2a...accumulator, 5, 5A...outdoor unit, 6A, 6B, 6C...indoor unit, 7A, 7B, 7C...switching unit, 8... refrigerant piping, 11... oil separator, 12A...first switching valve, 12B...second switching valve, 12C...third switching valve, 13, 13A...outdoor heat exchanger, 15, 15a, 15b...outdoor expansion valve, 16...accumulator, 17...outdoor fan, 18...inverter circuit, 19...control unit, 21A, 21B, 21C...indoor heat exchanger, 22A, 22B, 22C...indoor expansion valve, 23A, 23B, 23C...indoor fan, 25A, 25B, 25C...discharge gas pipe shutoff valve, 26A, 26B, 26C...suction gas pipe shutoff valve, 28...path, 29...header, 31a...main heat exchanger, 31b...auxiliary heat exchanger, 35, 36, 37, 38A, 38B, 38C, 39A, 39B, 39C...connecting pipe, 41, 42, 43...pipe connecting port of outdoor unit, 45A, 45B, 45C, 46A, 46B, 46C, 47A, 47B, 47C...pipe connecting port on outdoor unit side of switching unit, 48A, 48B, 48C, 49A, 49B, 49C...pipe connecting port on indoor unit side of switching unit, 51A, 51B, 51C, 52A, 52B, 52C...pipe connecting port of indoor unit, 61...first pipe, 62...second branch pipe, 63...third pipe, 64... fourth pipe, 65...fifth pipe, 66...sixth pipe, 67...seventh branch pipe, 68...eighth branch pipe, 69...ninth pipe, 70...10th pipe, 71A, 71B, 71C...11th pipe, 72A, 72B, 72C...12th branch pipe, 73A, 73B, 73C...13th pipe, 74A, 74B, 74C...14th pipe, 75A, 75B, 75C...15th pipe, 76A, 76B, 76C...16th pipe, 77A, 77B, 77C...17th pipe, 81...housing, 82...bottom plate, 83...column, 85...front plate, 86...front upper plate, 87... side face upper plate, 88... side face lower plate, 89...back plate, 90...fan guard, 91...electrical component box, 92...bell mouth, 93...fan base, 101, 102...end face of heat exchanger, 105...gas valve, 111a, 111b, 111c...valve body, 112a, 112b, 112c...valve box, 115a, 115b, 115c...first connecting port, 116a, 116b, 116c...second connecting port, 117a, 117b, 117c...third connecting port, 118a, 118b, 118c...fourth connecting port, 119a, 119b, 119c...pilot solenoid valve, 121a, 121b, 121c...small tube, 125...sealing plug, 131, 132...end face of heat exchanger, 135...sealing plug, 136...recovery pipe, 201A, 201B, 201C, 201D... comparative example of outdoor unit.

Examples

Embodiment Construction

[0020]An embodiment of an outdoor unit of an air conditioner according to the present invention and an embodiment of the air conditioner according to the present invention will be described with reference to Fig. 1 to Fig. 18. Note that same or corresponding configurations are denoted by same reference signs in a plurality of drawings.

[0021] Fig. 1 is a block diagram of the air conditioner according to the embodiment of the present invention.

[0022]As illustrated in Fig. 1, an air conditioner 1 according to the present invention is a heat-recovery multi-type air conditioner. The air conditioner 1 includes at least one outdoor unit 5 provided with a compressor 2 that compresses a refrigerant, a plurality of indoor units 6A, 6B,..., and a plurality of switching units 7A, 7B,... capable of switching a flowing direction of the refrigerant flowing to the indoor units 6A, 6B,.... In addition, the air conditioner 1 includes refrigerant piping 8 that successively connects the outdoor unit 5,...

Claims

1. An outdoor unit of an air conditioner, the outdoor unit comprising: a compressor that compresses a refrigerant; a first outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; a first switching valve that connects a discharge side of the compressor to the first outdoor heat exchanger to cause the first outdoor heat exchanger to function as a condenser, or connects a suction side of the compressor to the first outdoor heat exchanger to cause the first outdoor heat exchanger to function as an evaporator; a second outdoor heat exchanger that exchanges heat between the refrigerant and the outdoor air; a second switching valve that connects the discharge side of the compressor to the second outdoor heat exchanger to cause the second outdoor heat exchanger to function as a condenser, or connects the suction side of the compressor to the second outdoor heat exchanger to cause the second outdoor heat exchanger to function as an evaporator; and a third switching valve that shuts off connection of the discharge side of the compressor and indoor heat exchangers of all of indoor units to cause the first outdoor heat exchanger and the second outdoor heat exchanger to function as condensers, or connects the discharge side of the compressor to the indoor heat exchanger of at least one of the indoor units to cause the indoor heat exchanger of the at least one of the indoor units to function as a condenser, wherein the first switching valve is closer to the first heat exchanger than the third switching valve is, and wherein the second switching valve is closer to the first heat exchanger than the first switching valve is.

2. The outdoor unit of the air conditioner according to claim 1, wherein the first switching valve, the second switching valve, and the third switching valve are disposed on an outer side of a projection region in a normal direction of an end face of the first heat exchanger.

3. The outdoor unit of the air conditioner according to claim 2, wherein the first outdoor heat exchanger and the second outdoor heat exchanger are integrated and the end face of the first outdoor heat exchanger and an end face of the second outdoor heat exchanger form one continuous plane.

4. The outdoor unit of the air conditioner according to claim 3, wherein the first switching valve, the second switching valve, and the third switching valve are four-way valves, and include a first connecting port connectable to a condenser and a second connecting port connectable to an evaporator, and either one of the first connecting port and the second connecting port is closed.

5. The outdoor unit of the air conditioner according to claim 4, the outdoor unit further comprising a housing that houses the compressor, the first outdoor heat exchanger, the second outdoor heat exchanger, the first switching valve, the second switching valve, and the third switching valve, wherein the end face of the first outdoor heat exchanger and the end face of the second outdoor heat exchanger face a horizontal direction of the housing, and the first switching valve, the second switching valve, and the third switching valve each include a valve body, a valve box that houses the valve body movably in the horizontal direction, a third connecting port that hangs down below the valve box and is connected to the discharge side of the compressor, and a fourth connecting port that rises above the valve box and is connected to the suction side of the compressor.

6. The outdoor unit of the air conditioner according to claim 5, wherein the housing has a detachable side face, and the first switching valve, the second switching valve, and the third switching valve each include a pilot solenoid valve facing an inner surface of the side face.

7. The outdoor unit of the air conditioner according to any one of claims 1 to 6, the outdoor unit further comprising an accumulator connected to the suction side of the compressor, wherein the first heat exchanger is disposed above the second heat exchanger, and wherein the first switching valve, the second switching valve, and the third switching valve are disposed above the accumulator.

8. An air conditioner comprising: the outdoor unit according to any one of claims 1 to 7; a plurality of the indoor units; and a plurality of switching units that switch a flowing direction of the refrigerant flowing to the corresponding indoor units, wherein the outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger, wherein the indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger, and wherein the flowing direction of the refrigerant flowing to the plurality of indoor units is caused to be different from each other to mix the indoor units that perform a cooling operation and the indoor units that perform a heating operation.

9. An air conditioner comprising: the outdoor unit according to any one of claims 1 to 7; and a plurality of the indoor units, wherein the outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger, wherein the indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger, and wherein one of branches of the third switching valve is closed so as to cause the refrigerant to be sucked to the compressor through the third switching valve during a cooling operation and to cause the refrigerant to be sent to the plurality of indoor units through the third switching valve during a heating operation.

10. An air conditioner comprising: the outdoor unit according to any one of claims 1 to 7; and a plurality of the indoor units, wherein the outdoor unit includes an outdoor expansion valve connected to a discharge side of the first heat exchanger, wherein the indoor units each include an indoor heat exchanger and an indoor expansion valve connected to the indoor heat exchanger, wherein a flowing direction of the refrigerant flowing to the plurality of indoor units is caused to be different from each other to mix the indoor units that perform a cooling operation and the indoor units that perform a heating operation when a plurality of switching units that switch the flowing direction of the refrigerant flowing to the corresponding indoor units are provided, and wherein one of branches of the third switching valve is closed so as to cause the refrigerant to be sucked to the compressor through the third switching valve during the cooling operation and to cause the refrigerant to be sent to the plurality of indoor units through the third switching valve during the heating operation, the flowing direction of the refrigerant flowing to the plurality of indoor units is unified, and all of the indoor units are caused to perform the cooling operation or the heating operation when the plurality of switching units are not provided.

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