CN110050162B

CN110050162B - Air conditioner

Info

Publication number: CN110050162B
Application number: CN201780075496.0A
Authority: CN
Inventors: 高桥典夫; 渡边正彦; 寺内英树; 村若正俊; 渡边智畅
Original assignee: Hitachi Johnson Controls Air Conditioning Inc
Current assignee: Hitachi Johnson Controls Air Conditioning Inc
Priority date: 2017-04-11
Filing date: 2017-10-30
Publication date: 2021-03-02
Anticipated expiration: 2037-10-30
Also published as: EP3611439A4; JPWO2018189942A1; EP3611439A1; WO2018189942A1; JP6667719B2; MY191401A; CN110050162A; EP3611439B1

Abstract

First connection valves (82, 84, 86) are provided in refrigerant pipes connecting the refrigerant switching unit (20), the indoor heat exchangers (51, 52) or the hot water supply heat exchanger (61), second connection valves (81, 83, 85) are provided in refrigerant pipes connecting the outdoor heat exchanger (30), the indoor heat exchangers (51, 52) or the hot water supply heat exchanger (61), and refrigerant on-off valves (71, 72, 73) are provided in refrigerant pipes connecting the first connection valves (82, 84, 86), the indoor heat exchangers (51, 52) or the hot water supply heat exchanger (61).

Description

Air conditioner

Technical Field

The present invention relates to a multi-type air conditioner.

Background

The air conditioning mechanism includes an indoor unit installed indoors for air conditioning and an outdoor unit installed outdoors. In such an air conditioner, the installation location of the outdoor unit is particularly reduced. Therefore, in recent air conditioners, it is common to arrange two or more indoor units so as to be connected to one outdoor unit. Such an air conditioner is often called a multi-type air conditioner.

In general, a cooling operation and a heating operation of an indoor unit of an air conditioner are realized by changing a flow direction of a refrigerant supplied from an outdoor unit to the indoor unit to a reverse direction by a four-way valve or the like. Therefore, in a configuration of a general refrigeration cycle of a multi-type air conditioner in which one outdoor unit is connected to a plurality of indoor units, all of the plurality of indoor units can be in a cooling operation or all of the plurality of indoor units can be in a heating operation.

However, in recent years, as part of measures against global warming, hot water supply systems (or hot water systems) that employ the same refrigeration cycle as that of an air conditioner have begun to spread. Since such a hot water supply system is changed into warm water for heating water, the hot water supply system needs to function as a heating system in both winter and summer in a year.

When such a hot water supply system is incorporated into a multi-type air conditioner, it is necessary to cause some of the indoor units to function as a cooling system and some of the indoor units to function as a hot water supply system (i.e., a heating system) particularly in summer. Therefore, in the multi-type air conditioner, the hot water supply system cannot be easily assembled in a simple replacement manner of the indoor unit. In order to incorporate a hot water supply system into a multi-type air conditioner, various efforts have been made to provide a structure such as a refrigeration cycle. In addition, the simple replacement of the indoor unit means that the refrigerant pipe of the hot water supply system is connected to the refrigerant pipe for the purpose of connecting the indoor unit for indoor air conditioning exactly the same as the indoor unit for indoor air conditioning.

For example, fig. 1 of patent document 1 discloses an example of a hot-water supply air conditioner 1a in which a refrigerant from an outdoor unit 10 is separated into a refrigerant pipe connected to an indoor unit 30 and a refrigerant pipe connected to a hot-water storage tank 40 by a flow dividing unit 20 a. Fig. 2 of patent document 2 discloses an example of a hot-water supply air-conditioning system SS configured by separating a pipe of a gas refrigerant connected from the outdoor unit 1 into an exhaust gas pipe 35 connected to the hot-water supply unit 3 and a gas pipe 36 connected to the indoor unit 2.

Documents of the prior art

Patent document 1: japanese patent laid-open publication No. 2011-163654

Patent document 2: japanese patent laid-open publication No. 2013-130344

Disclosure of Invention

Problems to be solved by the invention

In the hot-water supply air conditioner 1a disclosed in patent document 1, in order to connect the hot-water supply system (hot-water storage tank 40) to the outdoor unit 10, the diversion unit 20a needs to be added again. Further, according to the structure of the outdoor unit 1 disclosed in patent document 2, a discharge gas pipe 35 connected to the hot water supply unit 3 and a gas pipe 36 connected to the indoor unit 2 are prepared, respectively, which is different from the structure of an outdoor unit of a general multi-type air conditioner. Therefore, the technique disclosed in patent document 2 cannot add a hot water supply system in a form that an outdoor unit of a general multi-type air conditioner is simply replaced. As described above, the conventional technology has a problem that the hot water supply system cannot be easily assembled to the multi-type air conditioner in a simple replacement manner of the indoor unit.

In view of the above-described problems of the prior art, an object of the present invention is to provide an air conditioner of a multiple type in which a plurality of indoor units are connected to one outdoor unit, the air conditioner being capable of a simple replacement connection of a hot water supply system as an indoor unit.

Means for solving the problems

The air conditioner of the invention comprises: a compressor for compressing a refrigerant; an outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air; a plurality of indoor heat exchangers for exchanging heat between the refrigerant and indoor air; a refrigerant switching unit that switches a flow direction of the refrigerant flowing through a refrigerant pipe connecting the compressor, the outdoor heat exchanger, and the plurality of indoor heat exchangers; a first connection valve for connecting refrigerant pipes provided in a first refrigerant pipe connecting the refrigerant switching unit and the plurality of indoor heat exchangers; a second connection valve for connecting refrigerant pipes provided in a second refrigerant pipe connecting the outdoor heat exchanger and the plurality of indoor heat exchangers; and a refrigerant opening/closing valve for opening/closing a refrigerant flow path between the first connection valve and each of the plurality of indoor heat exchangers provided in the first refrigerant pipe.

Effects of the invention

According to the present invention, in a multiple type air conditioner, a hot water supply system can be simply connected as a replacement of an indoor unit.

Drawings

Fig. 1 is a diagram schematically showing an example of a refrigeration cycle of an air conditioner according to a first embodiment.

Fig. 2 is a diagram showing an example of switching control of the opening and closing of the main valve, the refrigerant opening/closing valve, and the refrigerant regulating valve in each operation mode of the air conditioner according to the first embodiment.

Fig. 3 is a diagram schematically showing an example of a refrigeration cycle of an air conditioner according to a second embodiment.

Fig. 4 is a diagram schematically showing an example of a refrigeration cycle of an air conditioner according to a third embodiment.

Fig. 5 is a diagram schematically showing an example of a refrigeration cycle of an air conditioner according to a fourth embodiment.

Detailed Description

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "embodiment") will be described in detail with reference to the accompanying drawings as appropriate. In the drawings, the same reference numerals are used for the common portions, and redundant description is omitted.

First embodiment

Fig. 1 is a diagram schematically showing an example of a refrigeration cycle of an air conditioner S1 according to a first embodiment of the present invention. As shown in fig. 1, the air conditioner S1 includes a compressor 10, a refrigerant switching unit 20, an outdoor heat exchanger 30, an outdoor air-sending device 31, refrigerant adjusting valves 41 to 43,

indoor heat exchangers

51 and 52, a hot water supply tank 60, a hot water supply heat exchanger 61, refrigerant opening/closing valves 71 to 73, connection valves 81 to 86, a controller 90, and temperature detectors 91 to 94. In the drawings, solid lines connecting the respective components each other indicate refrigerant pipes serving as flow passages for the refrigerant (the same applies to the drawings below in fig. 3).

The air conditioner S1 shown in fig. 1 is a so-called multiple-type air conditioner including a plurality of indoor units (indoor heat exchangers 51 and 52) for one outdoor unit (outdoor heat exchanger 30).

In the air conditioner S1, the compressor 10 sucks the refrigerant from the suction portion and discharges the high-temperature and high-pressure refrigerant from the discharge portion. Here, the suction portion of the compressor 10 (in fig. 1, the refrigerant pipe connection portion on the left side of the compressor 10) is connected to the port d of the refrigerant switching portion 20 by a refrigerant pipe. Further, a discharge portion of the compressor 10 (a refrigerant pipe connection portion on the lower side of the compressor 10 in fig. 1) is connected to the port a of the refrigerant switching portion 20 by a refrigerant pipe. Further, a discharge temperature detector 91 that detects the temperature (discharge temperature) of the refrigerant discharged from the compressor 10 is provided at the discharge portion of the compressor 10. A detection signal detected by the discharge temperature detector 91 is input to the control unit 90, and the control unit 90 controls the compressor 10 so that the discharge temperature (the temperature detected by the discharge temperature detector 91) becomes a predetermined discharge target temperature.

The refrigerant switching unit 20 is a four-way valve having a switching main valve 21 and four ports a to d as connection portions of refrigerant pipes. As the refrigerant switching unit 20, for example, an electromagnetic valve (so-called clutch type electromagnetic valve) that can slide the switching main valve 21 by control such as energization and switch the connection relationship of the ports a to d can be used. Specifically, in the case where the switching main valve 21 is located at the position indicated by the solid line of fig. 1, the port a and the port b communicate, and the port c and the port d communicate. When the switching main valve 21 is located at a position indicated by a broken line in fig. 1, the port a communicates with the port c, and the port b communicates with the port d. The connection relationship between the ports a to d in the refrigerant switching unit 20, that is, the position of the switching main valve 21 is controlled by the control unit 90.

The outdoor heat exchanger 30 constitutes a part of the outdoor unit of the air conditioner S1, and exchanges heat between the refrigerant flowing in and the outdoor air. Here, one refrigerant pipe connection portion of the outdoor heat exchanger 30 (the refrigerant pipe connection portion on the upper side of the outdoor heat exchanger 30 in fig. 1) is connected to the port b of the refrigerant switching portion 20 by a refrigerant pipe. The other refrigerant pipe connection portion of the outdoor heat exchanger 30 (the refrigerant pipe connection portion on the lower side of the outdoor heat exchanger 30 in fig. 1) is connected to the refrigerant regulating valves 41 to 43 via refrigerant pipes having branches.

The outdoor unit of the air conditioner S1 includes an outdoor fan 31 for promoting heat exchange between the refrigerant in the outdoor heat exchanger 30 and the outdoor air. The outdoor fan 31 has its air flow rate (rotation speed) controlled by the control unit 90. An outdoor air temperature detector 92 that detects the temperature of the outdoor air is provided near the suction port of the outdoor air-sending device 31 (on the upstream side in the outdoor air flow direction 31a of the outdoor heat exchanger 30). The outdoor heat exchanger 30 is provided with an outdoor heat exchanger temperature detector 93 for detecting the temperature of the outdoor heat exchanger 30. Further, detection signals detected by the outdoor air temperature detector 92 and the outdoor heat exchanger temperature detector 93 are input to the control unit 90.

The refrigerant regulating valves 41 to 43 are valves that can be opened and closed and can be controlled in opening degree. One of the refrigerant pipe connection portions of the refrigerant adjusting valves 41 to 43 (in fig. 1, the refrigerant pipe connection portion on the left side of the refrigerant adjusting valves 41 to 43) is connected to the outdoor heat exchanger 30 by a refrigerant pipe. The other refrigerant pipe connection portion of the refrigerant adjusting valves 41 and 42 (the refrigerant pipe connection portion on the lower side of the

refrigerant adjusting valves

41 and 42 in fig. 1) is connected to the

indoor heat exchangers

51 and 52 via refrigerant pipes via the connection valves 81 and 83. The other refrigerant pipe connection portion of the refrigerant adjustment valve 43 (the refrigerant pipe connection portion on the lower side of the refrigerant adjustment valve 43 in fig. 1) is connected to the hot water supply heat exchanger 61 of the hot water supply tank 60 via a refrigerant pipe via a connection valve 85. The opening and closing and the opening of the refrigerant control valves 41 to 43 are controlled by the controller 90.

The

indoor heat exchangers

51 and 52 constitute a part of the indoor unit of the air conditioner S1, and exchange heat between the refrigerant flowing in and the indoor air. Here, one of the refrigerant pipe connections of the indoor heat exchangers 51, 52 (in fig. 1, the refrigerant pipe connection on the upper left of the indoor heat exchangers 51, 52) is connected to the

refrigerant regulating valves

41, 42 via the refrigerant pipes via the connection valves 81, 83. One refrigerant pipe connection portion of the hot water supply heat exchanger 61 of the hot water supply tank 60 (in fig. 1, the upper left refrigerant pipe connection portion of the hot water supply heat exchanger 61) is connected to the refrigerant adjustment valve 43 via a refrigerant pipe via a connection valve 85.

The other refrigerant pipe connection portion of the indoor heat exchangers 51 and 52 (the lower left refrigerant pipe connection portion of the

indoor heat exchangers

51 and 52 in fig. 1) is connected to the port c of the refrigerant switching portion 20 via a refrigerant pipe via the refrigerant opening/

closing valves

71 and 72 and the connection valves 82 and 84. The other refrigerant pipe connection portion of the hot water supply heat exchanger 61 of the hot water tank 60 (in fig. 1, the refrigerant pipe connection portion at the lower left of the hot water supply heat exchanger 61) is connected to the port c of the refrigerant switching unit 20 via a refrigerant pipe via the refrigerant opening/closing valve 73 and the connection valve 86.

Although not shown in fig. 1, each indoor unit includes a fan for taking indoor air into the casing and blowing out the air (conditioned by the air) heat-exchanged by the

indoor heat exchangers

51 and 52 into the room.

The air conditioner S1 includes a hot water supply tank 60 having a hot water supply heat exchanger 61. The tank water (hot water) is stored in the hot water supply tank 60, and the hot water supply heat exchanger 61 heats the tank water by exchanging heat between the high-temperature refrigerant and the tank water. In this case, the hot water supply tank 60 pushes up the tank water inside by, for example, flowing tap water from the lower side of the hot water supply tank 60, and directly supplies hot water from the upper side of the hot water supply tank 60 to a hot water supply terminal (for example, a faucet). The tank water is not limited to hot water.

As described above, one of the refrigerant pipe connections of the hot water supply heat exchanger 61 is connected to the refrigerant regulating valve 43 through the refrigerant pipe via the connection valve 85. The other refrigerant pipe connection portion of the hot water supply heat exchanger 61 is connected to the port c of the refrigerant switching unit 20 through a refrigerant pipe via the refrigerant opening/closing valve 73 and the connection valve 86. Further, a tank temperature detector 94 that detects the temperature of the stored tank water is provided in the hot water supply tank 60. A detection signal detected by the tank temperature detector 94 is input to the control unit 90.

In the example of fig. 1, the hot-water supply heat exchanger 61 is configured such that the refrigerant pipe is wound while being in contact with the outer periphery of the metal container of the hot-water supply tank 60. The hot water supply tank 60 and the hot water supply heat exchanger 61 are covered with an unillustrated heat insulator. Therefore, the refrigerant flowing into the hot-water supply heat exchanger 61 can exchange heat with the tank water stored in the hot-water supply tank 60 through the refrigerant pipe of the hot-water supply heat exchanger 61 and the metal container of the hot-water supply tank 60.

The structure of the hot-water supply heat exchanger 61 is not limited to the structure shown in the example of fig. 1. For example, the refrigerant pipe of the hot water supply heat exchanger 61 may be passed through the container from the container side surface of the hot water supply tank 60 to the inside of the container, and the refrigerant pipe may be disposed in the container of the hot water supply tank 60. In this case, the refrigerant flowing into the hot-water supply heat exchanger 61 can exchange heat with the tank water stored in the hot-water supply tank 60 through the refrigerant pipe of the hot-water supply heat exchanger 61. In this case, the refrigerant pipe disposed inside the hot water supply tank 60 may be a double pipe to protect the refrigerant pipe of the hot water supply heat exchanger 61.

Alternatively, the hot water supply tank 60 may be provided with a hot water supply heat exchanger 61 separate from the hot water supply tank 60, a flow passage through which tank water flowing out from the lower portion of the hot water supply tank 60 flows to the upper portion of the hot water supply tank 60 via the hot water supply heat exchanger 61, and a pump provided in the flow passage.

As shown in fig. 1, in the air conditioner S1 of the first embodiment, the refrigerant pipe connected to the port c of the refrigerant switching unit 20 branches into a plurality of refrigerant pipes in the middle, and the branched refrigerant pipes are connected to the

indoor heat exchangers

51 and 52 and the hot water supply heat exchanger 61. The refrigerant pipes after branching (hereinafter referred to as first branch refrigerant pipes) are provided with

connection valves

82, 84, and 86. Further, the refrigerant opening/

closing valves

71, 72, 73 are provided in the refrigerant pipes of the first branch refrigerant pipes, which connect the

connection valves

82, 84, 86 to the

indoor heat exchangers

51, 52 or the hot-water supply heat exchanger 61.

Similarly, the refrigerant pipe connected to one refrigerant pipe connection portion of the outdoor heat exchanger 30 (the refrigerant pipe connection portion on the lower side of the outdoor heat exchanger 30 in fig. 1) branches into a plurality of refrigerant pipes in the middle, and the branched refrigerant pipes are connected to the

indoor heat exchangers

51 and 52 or the hot water supply heat exchanger 61. The branched refrigerant pipes (hereinafter referred to as second branched refrigerant pipes) are provided with

connection valves

81, 83, and 85. Further, the

refrigerant regulating valves

41, 42, and 43 are provided in the second branch refrigerant pipes at positions closer to the outdoor heat exchanger 30 than the positions where the

connection valves

81, 83, and 85 are provided.

Therefore, the connection valves 81 to 86 can be referred to as connection points of refrigerant pipes of the outdoor unit (the compressor 10, the outdoor heat exchanger 30, the refrigerant switching unit 20, and the like) and the indoor units (the

indoor heat exchangers

51 and 52, the hot water supply tank 60, and the like) of the cut-off air conditioner S1. Therefore, in the first embodiment, the indoor units having the

indoor heat exchangers

51 and 52 and the hot water supply system having the hot water supply heat exchanger 61 can be connected to the outdoor unit by the connection valves 81 to 86 in the same manner.

That is, in the first embodiment, the refrigerant pipes connected to the

indoor heat exchangers

51 and 52 or the hot water supply heat exchanger 61 can be connected to any one of the groups of

connection valves

81, 82, 83, 84, 85, and 86 in the same manner. That is, in the multi-type air conditioner S1 according to the first embodiment, the hot water supply system including the hot water supply heat exchanger 61 can be connected as a simple replacement of the indoor units including the

indoor heat exchangers

51 and 52.

In the first embodiment, the refrigerant regulating valves 41 to 43 are disposed in the refrigerant pipes connected to the

indoor units

51 and 52 or the hot-water supply heat exchanger 61 at positions farther from the

indoor units

51 and 52 or the hot-water supply heat exchanger 61 than the

connection valves

81, 83, and 85. That is, the refrigerant control valves 41 to 43 are provided on the outdoor unit side. However, the positions where the refrigerant regulating valves 41 to 43 are provided are not limited to the outdoor unit side, and may be provided on the indoor unit side. That is, the refrigerant control valves 41 to 43 may be provided in the refrigerant pipes connected to the

indoor units

51 and 52 or the hot-water supply heat exchanger 61 at positions closer to the

indoor units

51 and 52 or the hot-water supply heat exchanger 61 than the

connection valves

81, 83, and 85.

In the general multi-type air conditioner, the refrigerant on-off valves 71 to 73 are not essential, but in the first embodiment, they are introduced in relation to a hot water supply system including the hot water supply heat exchanger 61. However, since the refrigerant on-off valves 71 to 73 are connected to the

connection valves

82, 84, and 86, the refrigerant on-off valves 71 to 73 can be easily installed even when a general indoor unit is used. Therefore, the hot water supply heat exchanger 61 can be easily configured to have the refrigerant on-off valves 71 to 73 when connected to any of the

groups

81, 82, 83, 84, 85, 86 of connection valves, and to have no refrigerant on-off valves 71 to 73 when not connected to any of the groups.

Next, the details of various operations of the air conditioner S1 will be described in detail with reference to fig. 1 and 2. Fig. 2 is a diagram showing the control of opening and closing the switching main valve 21, the refrigerant opening/closing valves 71 to 73, and the refrigerant adjusting valves 41 to 43 in each operation mode of the air conditioner S1 according to the first embodiment. In fig. 1, solid arrows near the refrigerant pipes indicate the flow direction of the refrigerant during the cooling operation, and broken arrows indicate the flow direction of the refrigerant during the heating operation.

As shown in fig. 2, the air conditioner S1 basically has three operation modes of a cooling operation for cooling the room, a heating operation for heating the room, and a boiling operation for heating the tank water in the hot water supply tank 60. More specifically, the cooling operation includes boiling priority cooling operation for heating the tank water during the cooling operation, and the heating operation includes heating/boiling operation for heating the tank water during the heating operation (boiling priority heating operation in the figure). The heating operation includes a normal defrosting operation, a comfort defrosting operation, and a quick defrosting operation for removing frost adhering to the outdoor heat exchanger 30 during the heating operation, and the boiling operation includes the same comfort defrosting operation.

These operation modes are set by the user or manager of the air conditioner S1 via a control panel or a remote control device connected to the control unit 90. The controller 90 controls the opening and closing of the switching main valve 21, the refrigerant regulating valves 41 to 43, and the refrigerant opening and closing valves 71 to 73 according to the set operation mode.

< Cooling operation >

When the

indoor heat exchangers

51 and 52 are on for cooling and the hot water supply heat exchanger 61 is off, the controller 90 sets the air conditioner S1 to the cooling operation mode. At this time, the control unit 90 operates the compressor 10 and the outdoor fan 31 to set the switching main valve 21 of the refrigerant switching unit 20 at the position indicated by the solid line in fig. 1. The controller 90 opens the refrigerant opening/closing valves 71 to 73 and closes the refrigerant regulating valve 43 to control the opening degrees of the

refrigerant regulating valves

41 and 42.

Here, both the

indoor heat exchangers

51 and 52 are on for cooling, but even when one is on for cooling and the hot-water supply heat exchanger 61 is off, the controller 90 sets the cooling operation mode to the air conditioner S1. However, in this case, the refrigerant regulating valve 41, 442 connected to the one of the

indoor heat exchangers

51, 52 whose cooling is not on is closed. In the following description of the present specification, in order to avoid the complexity of the description, both the

indoor heat exchangers

51 and 52 are on or off for cooling, or both are on or off for heating.

In this cooling operation, the high-temperature and high-pressure refrigerant discharged from the compressor 10 flows into the outdoor heat exchanger 30 functioning as a condenser through the ports a and b of the refrigerant switching unit 20, and exchanges heat with the outdoor air to release heat. The refrigerant that has dissipated heat in the outdoor heat exchanger 30 and has been liquefied flows into the

refrigerant regulating valves

41 and 42 that function as expansion valves, is depressurized, becomes a low-temperature, low-pressure, gas-liquid mixed refrigerant, and absorbs heat by exchanging heat with the indoor air by the

indoor heat exchangers

51 and 52 that function as evaporators. At this time, the indoor air having absorbed heat by the refrigerant and having a reduced temperature is blown out from the indoor unit into the room, thereby cooling the room. The refrigerant that has absorbed heat in the

indoor heat exchangers

51 and 52 and has been evaporated is sucked into the compressor 10 through the ports c and d of the refrigerant switching unit 20.

The air conditioner S1 can cool the room in which the indoor units (the indoor heat exchangers 51 and 52) are installed by the above cooling operation.

< cooling operation with boiling priority >

In the cooling operation, when the hot water supply heat exchanger 61 is turned on, the control unit 90 sets the air conditioner S1 to the cooling operation mode in which boiling is prioritized. At this time, the controller 90 turns off the

indoor heat exchangers

51 and 52 to a standby state, sets the switching main valve 21 of the refrigerant switching unit 20 at a position indicated by a broken line in fig. 1, and opens the refrigerant on-off valve 73. In this case, the refrigerant that has been brought to a high temperature and a high pressure by the compressor 10 flows into the hot water supply heat exchanger 61 through the refrigerant opening/closing valve 73, and the tank water in the hot water supply tank 60 is pressurized and warmed to liquefy itself. After that, the refrigerant is decompressed by the opening degree control of the refrigerant adjustment valve 43, flows into the outdoor heat exchanger 30, absorbs heat, and is gasified.

At this time, since the refrigerant opening/

closing valves

71 and 72 are closed, the high-temperature refrigerant does not flow into the

indoor heat exchangers

51 and 52. Therefore, adverse effects on the cooling in the room (increase in the room temperature) caused by the boiling operation of the tank water can be suppressed. In this operation, the

refrigerant regulating valves

41 and 42 are opened, and therefore the refrigerant can be effectively used in the hot water supply heat exchanger 61.

However, generally, the temperature fluctuation range in the indoor cooling is about 27 to 35 ℃, and the temperature fluctuation range in the server room during cooling is about 8 to 10 ℃. In addition, the temperature variation range in indoor heating is 0-20 ℃. In any case, the range of temperature variation is within 30 ℃. On the other hand, the range of temperature variation in the hot water supply tank 60 is, for example, 0 to 55 ℃, and is significantly wider than indoor cooling and indoor heating. Therefore, in the boiling operation for heating the tank water in the hot water supply tank 60, the controller 90 sets the target discharge temperature of the compressor 10 to be higher than that in the cooling operation and the heating operation.

When the temperature of the tank water in the hot-water supply tank 60 reaches the predetermined target boiling temperature by the above control of the cooling operation with boiling priority, the control unit 90 stops the control of the boiling operation, cancels the standby of the

indoor heat exchangers

51 and 52, and resumes the control of the normal cooling operation again.

Further, although detailed description is omitted, in the cooling operation with boiling priority, it is also considered that comfort in the room is impaired because the cooling air conditioner is substantially stopped. Therefore, in order not to impair the comfort in the room, the upper limit time for performing the boiling operation is set, and the boiling operation can be stopped when the temperature of the tank water does not reach the predetermined target boiling temperature even if the upper limit time is exceeded. When the boiling operation is stopped, the operation is resumed to the cooling operation, but when the boiling operation is stopped, an auxiliary heater (heating means) is provided in the hot water supply tank 60, and the auxiliary heater is energized to replace the boiling of the tank water.

In this way, the air conditioner S1 of the first embodiment can perform the boiling operation while suppressing the influence of the cooling operation and the comfort in the room.

< heating operation >

When the

indoor heat exchangers

51 and 52 are on for heating and the hot-water supply heat exchanger 61 is off, the controller 90 sets the air conditioner S1 to the heating operation mode. At this time, the control unit 90 operates the compressor 10 and the outdoor fan 31 to set the switching main valve 21 of the refrigerant switching unit 20 at the position indicated by the broken line in fig. 1. The controller 90 opens the refrigerant opening/

closing valves

71 and 72, closes the refrigerant opening/closing valve 73, controls the opening degrees of the

refrigerant adjusting valves

41 and 42, and opens the refrigerant adjusting valve 43.

In the heating operation, the high-temperature and high-pressure refrigerant discharged from the compressor 10 flows into the

indoor heat exchangers

51 and 52 functioning as condensers via the ports a and c of the refrigerant switching unit 20, exchanges heat with the indoor air, is liquefied, and radiates heat. At this time, the indoor air whose temperature has risen due to heat radiation from the refrigerant is blown out from the indoor unit into the room, thereby heating the room. The refrigerant having dissipated heat in the

indoor heat exchangers

51 and 52 flows into the

refrigerant regulating valves

41 and 42 functioning as expansion valves, becomes a low-temperature and low-pressure gas-liquid mixed refrigerant, exchanges heat with outdoor air in the outdoor heat exchanger 30 functioning as an evaporator, absorbs heat, and is gasified. The refrigerant that has absorbed heat in the outdoor heat exchanger 30 and evaporated is sucked into the compressor 10 through the ports b and d of the refrigerant switching unit 20.

In this way, the air conditioner S1 of the first embodiment can perform heating of the room in which the indoor units (the indoor heat exchangers 51 and 52) are installed by performing the heating operation.

(modification of heating operation)

In general, at the start of the heating operation, the temperature of the refrigerant supplied to the

indoor heat exchangers

51 and 52 is low because the discharge temperature of the compressor 10 is low. Therefore, the air conditioner S1 has a low heating capacity when the heating operation is started. Therefore, in this modification, when the temperature of the tank water in the hot water supply tank 60 (the temperature detected by the tank temperature detector 94) is equal to or higher than a predetermined first tank water temperature (for example, 15 ℃) at the start of the heating operation, the controller 90 opens the refrigerant on-off valve 73 and controls the opening degree of the refrigerant adjusting valve 43.

In this case, at least a part (or all) of the refrigerant discharged from the compressor 10 flows through the hot-water supply heat exchanger 61. That is, the refrigerant can be warmed by the heat of the tank water in the hot water supply tank 60. Therefore, the temperature of the refrigerant supplied to the

indoor heat exchangers

51, 52 can be rapidly increased, and the air conditioner S1 having good response to the request of the user for the heating operation can be provided.

In the above heating operation, when the temperature of the refrigerant discharged from the compressor 10 (the temperature detected by the discharge temperature detector 91) is equal to or higher than a predetermined discharge temperature (for example, 20 ℃), the controller 90 may shift to a normal heating operation in which the refrigerant opening/closing valve 73 is closed and the refrigerant adjustment valve 43 is opened.

When the indoor temperature is a predetermined set room temperature and the temperature of the tank water in the hot water supply tank 60 (the temperature detected by the tank temperature detector 94) is a predetermined second tank water temperature (for example, 40 degrees centigrade higher than the set room temperature) or higher, the controller 90 may perform the following control. That is, the controller 90 stops the compressor 10 and the outdoor fan 31, sets the switching main valve 21 of the refrigerant switching unit 20 at the position indicated by the broken line in fig. 1, closes the refrigerant adjusting valves 41 to 43, and opens the refrigerant switching valves 71 to 72.

When such control is performed, the flow of the refrigerant in the refrigerant pipe is stopped. However, the refrigerant pipe from the hot-water supply heat exchanger 61 to the port c of the refrigerant switching unit 20 via the connection valve 86 and the refrigerant pipe from the

indoor heat exchangers

51 and 52 to the port c of the refrigerant switching unit 20 via the connection valves 82 and 84 are thermally connected to each other. That is, the heat of the tank water in the hot water supply tank 60 is supplied to the

indoor heat exchangers

51 and 52 by natural convection of the refrigerant in the refrigerant pipes or heat conduction in the refrigerant pipes. Therefore, a temperature drop in the room to be heated can be suppressed.

< heating and boiling operation >

In the heating and boiling operation, the controller 90 operates the compressor 10 and the outdoor fan 31, sets the switching main valve 21 of the refrigerant switching unit 20 at a position indicated by a broken line in fig. 1, opens the refrigerant opening/closing valves 71 to 73, and controls the opening degrees of the refrigerant adjusting valves 41 to 43.

The high-temperature and high-pressure refrigerant discharged from the compressor 10 flows into the hot-water supply heat exchanger 61 functioning as a condenser through the ports a and c of the refrigerant switching unit 20 and the refrigerant on-off valve 73, and exchanges heat with the tank water in the hot-water supply tank 60 to dissipate heat. At this time, the tank water in the boiled water tank 60 is heated (boiled) by the heat released from the refrigerant. The high-temperature and high-pressure refrigerant discharged from the compressor 10 also flows into the

indoor heat exchangers

51 and 52 functioning as high-temperature and high-pressure refrigerant condensers, and exchanges heat with the indoor air to dissipate heat. At this time, the indoor air, which has been heated by heat dissipation from the refrigerant and has increased in temperature, is blown out from the indoor unit into the room, and air conditioning (heating) is performed on the room. The refrigerant that has dissipated heat in the hot water supply heat exchanger 61 and the

indoor heat exchangers

51 and 52 and has been liquefied flows into the refrigerant adjustment valves 41 to 43 functioning as expansion valves, respectively, becomes a low-temperature and low-pressure refrigerant, and absorbs heat and vaporizes by exchanging heat with outdoor air in the outdoor heat exchanger 30 functioning as an evaporator. The refrigerant that has absorbed heat in the outdoor heat exchanger 30 and evaporated is sucked into the compressor 10 through the ports b and d of the refrigerant switching unit 20.

In this way, the air conditioner S1 according to the first embodiment can perform the heating and boiling operation to heat the room in which the indoor units (indoor heat exchangers 51 and 52) are installed and can boil the tank water in the hot water supply tank 60 by a part of the condenser.

After that, upon receiving the off command of the hot-water supply heat exchanger 61, the controller 90 shifts to the normal heating operation.

< boiling operation >

In the boiling operation, the control unit 90 operates the compressor 10 and the outdoor fan 31 to set the switching main valve 21 of the refrigerant switching unit 20 at a position indicated by a broken line in fig. 1. The controller 90 closes the refrigerant opening/

closing valves

71 and 72, opens the

refrigerant adjusting valves

41 and 42, opens the refrigerant opening/closing valve 73, and controls the opening degree of the refrigerant adjusting valve 43.

The high-temperature and high-pressure refrigerant discharged from the compressor 10 flows into the hot-water supply heat exchanger 61 functioning as a condenser through the ports a and c of the refrigerant switching unit 20 and the refrigerant on-off valve 73, and exchanges heat with the tank water in the hot-water supply tank 60 to dissipate heat. At this time, the tank water in the boiled water tank 60 is heated (boiled) by the heat released from the refrigerant. The refrigerant that has radiated heat from the hot-water supply heat exchanger 61 flows into the refrigerant regulating valve 43 that functions as an expansion valve, becomes a low-temperature and low-pressure refrigerant, and absorbs heat by exchanging heat with outdoor air in the outdoor heat exchanger 30 that functions as an evaporator. The refrigerant having absorbed heat in the outdoor heat exchanger 30 is sucked into the compressor 10 through the ports b and d of the refrigerant switching unit 20.

In the boiling operation, the refrigerant opening/

closing valves

71 and 72 are closed, and the refrigerant does not flow through the

indoor heat exchangers

51 and 52, so that an increase in the indoor temperature can be suppressed. Further, by opening the

refrigerant adjustment valves

41 and 42, unnecessary refrigerant accumulation in the

indoor heat exchangers

51 and 52 can be suppressed.

In this way, the air conditioner S1 according to the first embodiment can boil the tank water in the hot water tank 60 by performing the boiling operation without cooling or heating the room.

< defrosting operation >

In the heating operation, the heating/boiling operation, and the boiling operation, the outdoor heat exchanger 30 functions as an evaporator, and the refrigerant absorbs heat to cool the outdoor air. Therefore, when the humidity of the outdoor air is high and the temperature of the outdoor air is low, frost may adhere to the outdoor heat exchanger 30 and degrade the heat exchange performance of the outdoor heat exchanger 30. Therefore, the air conditioner S1 can perform a defrosting operation (defrosting operation) for removing the attached frost.

The control unit 90 estimates the amount of frost adhering to the outdoor heat exchanger 30 by calculating, for example, an outdoor dew point based on the temperature of the outdoor heat exchanger 30 detected by the outdoor air temperature detector 92 and the temperature of the outdoor air detected by the outdoor heat exchanger temperature detector 93. Then, for example, when the estimated frost amount exceeds a frost amount that is a predetermined threshold value, the control unit 90 executes a defrosting operation.

In the air conditioner S1 according to the first embodiment, the following three-mode defrosting operation can be performed.

(defrosting operation in general)

In the normal defrosting operation, the controller 90 operates the compressor 10, sets the switching main valve 21 of the refrigerant switching unit 20 to the position indicated by the solid line in fig. 1, opens the refrigerant on-off

valves

71 and 72 and the

refrigerant adjusting valves

41 and 42, and closes the refrigerant on-off valve 73 and the refrigerant adjusting valve 43.

The discharge refrigerant discharged from the compressor 10 flows into the outdoor heat exchanger 30 through the ports a and b of the refrigerant switching unit 20, and exchanges heat with the outdoor air to release heat. At this time, the refrigerant dissipates heat into the outdoor air, and frost adhering to the outdoor heat exchanger 30 melts. The refrigerant that has released heat in the outdoor heat exchanger 30 passes through the

refrigerant control valves

41 and 42, exchanges heat with the indoor air in the

indoor heat exchangers

51 and 52, and absorbs heat. In addition, the temperature in the room decreases by absorbing heat from the indoor air. The refrigerant having absorbed heat in the

indoor heat exchangers

51 and 52 is sucked into the compressor 10 through the ports c and d of the refrigerant switching unit 20.

In this way, the air conditioner S1 according to the first embodiment can remove frost adhering to the outdoor heat exchanger 30 by performing the normal defrosting operation.

(comfortable defrosting operation)

The comfortable defrosting operation is selected when the temperature of the tank water in the hot water supply tank 60 is equal to or higher than a predetermined temperature (for example, 20 ℃) or when the temperature of the tank water is equal to or higher than the discharge temperature of the compressor 10 (the detection temperature of the discharge temperature detector 91). The predetermined temperature may be the same as or different from the first tank water temperature and the second tank water temperature in the above-described modification of the heating operation.

The comfort defrosting operation is different from the normal defrosting operation in that the refrigerant discharged from the compressor 10 flows into the hot water supply heat exchanger 61 and does not flow into the

indoor heat exchangers

51 and 52. That is, during the comfort defrosting operation, the controller 90 operates the compressor 10, sets the switching main valve 21 of the refrigerant switching unit 20 at the position indicated by the solid line in fig. 1, opens the refrigerant on-off valve 73 and the refrigerant adjusting valve 43, and closes the refrigerant on-off

valves

71 and 72 and the

refrigerant adjusting valves

41 and 42.

The discharge refrigerant discharged from the compressor 10 flows into the outdoor heat exchanger 30 through the ports a and b of the refrigerant switching unit 20, and exchanges heat with the outdoor air to dissipate heat. At this time, the refrigerant dissipates heat into the outdoor air, and frost adhering to the outdoor heat exchanger 30 melts. The refrigerant having dissipated heat in the outdoor heat exchanger 30 flows into the hot water supply heat exchanger 61 functioning as a heat source via the refrigerant adjustment valve 43, and is heated by exchanging heat with the high-temperature tank water in the hot water supply tank 60. Further, the temperature of the tank water in the hot water supply tank 60 decreases by absorbing heat to the tank water. The refrigerant heated by the hot water supply heat exchanger 61 is sucked into the compressor 10 through the refrigerant opening/closing valve 73 and the ports c and d of the refrigerant switching unit 20.

In this way, the air conditioner S1 according to the first embodiment can remove frost adhering to the outdoor heat exchanger 30 by performing the comfort defrosting operation. In addition, while defrosting is performed using the heat in the room in the normal defrosting operation, defrosting is performed using the heat of the tank water in the hot water supply tank 60 in the comfort defrosting operation. Therefore, during the comfortable defrosting operation, the temperature in the room can be suppressed from decreasing compared to the case of the normal defrosting operation.

(quick defrosting operation)

The quick defrosting operation is selected when the temperature of the tank water in the hot water supply tank 60 is equal to or higher than a predetermined temperature (for example, 20 ℃), or when the temperature of the tank water is equal to or higher than the discharge temperature of the compressor 10 (the detection temperature of the discharge temperature detector 91). The predetermined temperature may be the same as or different from the first tank water temperature and the second tank water temperature in the above-described modification of the heating operation. Further, whether the comfortable defrosting operation or the quick defrosting operation is selected is separately set by the user of the air conditioner S1.

In the quick defrosting operation, the controller 90 operates the compressor 10, sets the switching main valve 21 of the refrigerant switching unit 20 at the position indicated by the solid line in fig. 1, opens the refrigerant regulating valves 41 to 43, and also opens the refrigerant opening/closing valves 71 to 73.

The high-temperature and high-pressure refrigerant discharged from the compressor 10 flows into the outdoor heat exchanger 30 through the ports a and b of the refrigerant switching unit 20, and exchanges heat with outdoor air to dissipate heat. At this time, the refrigerant dissipates heat into the outdoor air, and frost adhering to the outdoor heat exchanger 30 melts. The refrigerant having dissipated heat in the outdoor heat exchanger 30 flows into the

indoor heat exchangers

51 and 52 and the hot water supply heat exchanger 61 through the refrigerant control valves 41 to 43, absorbs heat, and is then sucked into the compressor 10 through the ports c and d of the refrigerant switching unit 20 in the refrigerant opening/closing valves 71 to 73.

In this way, the air conditioner S1 according to the first embodiment can remove frost adhering to the outdoor heat exchanger 30 by performing the quick defrosting operation. In addition, in the normal defrosting operation, heat is absorbed from the

indoor heat exchangers

51 and 52, while in the quick defrosting operation, heat is absorbed from the hot water supply heat exchanger 61, so that defrosting of the outdoor heat exchanger 30 can be performed in a short time.

< Effect >

As described above, according to the air conditioner S1 of the first embodiment, the cooling operation, the heating operation, and the boiling operation can be performed separately. In addition, even during the cooling operation and the heating operation, the tank water in the hot-water supply tank 60 can be boiled (cooling operation with boiling priority, heating operation with boiling priority). In addition, according to the air conditioner S1 of the first embodiment, it is possible to perform an appropriate defrosting operation (a normal defrosting operation, a comfortable defrosting operation, and a quick defrosting operation).

In addition, according to the air conditioner S1 of the first embodiment, the refrigerant pipe connected to the port c of the refrigerant switching unit 20 is branched into a plurality of refrigerant pipes, and each of the branched refrigerant pipes is connected to the

indoor heat exchangers

51 and 52 or the hot water supply heat exchanger 61. The refrigerant pipes after branching (first branch refrigerant pipes) are provided with

connection valves

82, 84, and 86. Similarly, the refrigerant pipe connected to one of the refrigerant pipe connections of the outdoor heat exchanger 30 branches into a plurality of refrigerant pipes, and each of the branched refrigerant pipes (first branch refrigerant pipes) is connected to the

indoor heat exchangers

51 and 52 or the hot water supply heat exchanger 61. The refrigerant pipes (second branch refrigerant pipes) after branching are provided with

connection valves

81, 83, and 85. Therefore, all the refrigerant pipes connected from the

indoor heat exchangers

51 and 52 or the hot water supply heat exchanger 61 can be connected to any one of the group of

connection valves

81, 82, 83, 84, 85, and 86 in the same manner.

Second embodiment

Fig. 3 is a diagram schematically showing an example of a refrigeration cycle of an air conditioner S2 according to a second embodiment of the present invention. As shown in fig. 3, an air conditioner S2 of the second embodiment is different from the air conditioner S1 of the first embodiment in that 6 connection valves 81 to 86 are provided in the air conditioner S1 of the first embodiment, and only two

connection valves

81 and 82 are provided.

That is, in the second embodiment, the connection valve 82 is provided in a portion of the refrigerant pipe (hereinafter referred to as a first common refrigerant pipe) immediately before the refrigerant pipe in which the refrigerant pipe connected to the port c of the refrigerant switching unit 20 branches into the plurality of refrigerant pipes. Similarly, a connection valve 81 is provided in a refrigerant pipe portion (hereinafter referred to as a second common refrigerant pipe) in front of the refrigerant pipes in which the refrigerant pipe connected to one refrigerant pipe connection portion of the outdoor heat exchanger 30 (the refrigerant pipe connection portion on the lower side of the outdoor heat exchanger 30 in fig. 1) branches into the plurality of refrigerant pipes.

That is, the refrigerant on-off valves 71 to 73 and the refrigerant adjusting valves 41 to 43 are provided on the

indoor heat exchangers

51 and 52 side or the hot water supply heat exchanger 61 side of the

connection valves

81 and 82. Specifically, the first common refrigerant pipe provided with the connection valve 82 is branched into a plurality of refrigerant pipes, and each of the branched refrigerant pipes (hereinafter referred to as a first branched refrigerant pipe) is connected to the

indoor heat exchangers

51 and 52 or the hot water supply heat exchanger 61. The refrigerant opening/

closing valves

71, 72, and 73 are provided in the respective first branch refrigerant pipes. Similarly, the second common refrigerant pipe provided with the connection valve 81 is branched into a plurality of refrigerant pipes, and the branched refrigerant pipes (hereinafter referred to as second branched refrigerant pipes) are connected to the

indoor heat exchangers

51 and 52 or the hot water supply heat exchanger 61. The second branch refrigerant pipes are provided with refrigerant regulating

valves

41, 42, and 43, respectively.

Except for the above configuration, the configuration of the refrigeration cycle of the air conditioner S2 of the second embodiment is the same as that of the air conditioner S1 of the first embodiment. Therefore, the air conditioner S2 of the second embodiment can perform the operation in the same operation mode as in the case of the first embodiment. That is, the air conditioner S2 has three operation modes of the cooling operation, the heating operation, and the boiling operation. The cooling operation includes a boiling priority cooling operation, the heating operation includes a boiling priority operation, a normal defrosting operation, a comfort defrosting operation, and a quick defrosting operation, and the boiling operation includes a comfort defrosting operation.

In these operation modes, the control of switching the main valve 21, the refrigerant on/off valves 71 to 73, and the refrigerant adjusting valves 41 to 43 by the controller 90 is the same as the control shown in fig. 2, and therefore, the control operation in each operation mode will not be described here.

Therefore, the air conditioner S2 according to the second embodiment can also obtain substantially the same effects as those of the air conditioner S1 according to the first embodiment.

Third embodiment

Fig. 4 schematically shows an example of a refrigeration cycle of an air conditioner S3 according to a third embodiment of the present invention. As shown in fig. 4, the basic refrigeration cycle of the air conditioner S3 of the third embodiment has substantially the same configuration as the refrigeration cycle of the air conditioner S2 of the second embodiment shown in fig. 3, but differs therefrom in the following points.

That is, in the air conditioner S2 according to the second embodiment, only one

connection valve

81, 82 is provided in each of the common refrigerant pipes in front of the plurality of refrigerant pipes into which the refrigerant pipes connected to the refrigerant switching unit 20 and the outdoor heat exchanger 30 are branched. On the other hand, in the air conditioner S3 according to the third embodiment, for example, 8 connection valves 81a to 88a are added, and the 8 connection valves 81a to 88a and the three refrigerant regulating valves 41 to 43 are integrally housed in the branch box 100.

Here, the

connection valves

81a and 82a provided in the branch tank 100 are connected to the

connection valves

81 and 82 provided on the outdoor unit side by refrigerant pipes. In the branch tank 100, the refrigerant pipes connected to the

connection valves

81a and 82a are branched into, for example, three branch refrigerant pipes, and the connection valves 83a to 88a are provided at the distal ends of the three (six in total) branch refrigerant pipes after branching. The refrigerant regulating valves 41 to 43 are provided in the respective branch refrigerant pipes connecting the connection valve 81a and the

connection valves

83a, 85a, and 87 a.

The branch box 100 is disposed in a corner of a room where a face is washed, for example. The

connection valves

83a, 85a, and 87a in the branch tank 100 are connected to refrigerant pipe connection portions of one of the

indoor heat exchangers

51 and 52 and the hot-water supply heat exchanger 61 through indoor refrigerant pipes, respectively. The

connection valves

84a, 86a, and 88a are connected to the other refrigerant pipe connection portion of the

indoor heat exchangers

51 and 52 and the hot water supply heat exchanger 61, respectively, by refrigerant pipes passing through the refrigerant opening/closing valves 71 to 73.

As can be readily seen from fig. 4, the

sets

83a, 84a, 85a, 86a, 87a, 88a of connection valves in the branch box 100 are all equivalent. Therefore, the

indoor heat exchangers

51 and 52 and the hot-water supply heat exchanger 61 can be connected to the respective sets of

connection valves

83a, 84a, 85a, 86a, 87a, and 88a in any combination.

The configuration of the refrigeration cycle of the air conditioner S3 of the third embodiment is basically the same as the configuration of the refrigeration cycle of the air conditioner S1 of the first embodiment. Therefore, the air conditioner S3 of the third embodiment can perform the operation in the same operation mode as in the case of the first embodiment. That is, the air conditioner S3 has three operation modes, i.e., a cooling operation, a heating operation, and a boiling operation. The cooling operation includes a boiling priority cooling operation, the heating operation includes a boiling priority heating operation, a normal defrosting operation, a comfort defrosting operation, and a quick defrosting operation, and the boiling operation includes a comfort defrosting operation.

Therefore, in the air conditioner S3 of the third embodiment, the same effects as those of the air conditioner S1 of the first embodiment can be obtained. In the third embodiment, by providing the branch tank 100, the refrigerant pipes connecting the

connection valves

81 and 82 on the outdoor unit side and the

connection valves

81a and 82a in the branch tank 100 can be made common refrigerant pipes without branching, and therefore the overall refrigerant pipe length can be reduced.

Further, although some degree of noise is generated from the refrigerant adjusting valves 41 to 43 in accordance with the opening and closing of the valves and the control of the opening degree, the branch tank 100 including the refrigerant adjusting valves 41 to 43 may be installed outdoors. In addition, even when installed indoors, the device can be installed in places where people wash their faces with little noise. Therefore, the noise from the refrigerant adjustment valve 4143 can be prevented from interfering with the occupants indoors.

Fourth embodiment

Fig. 5 is a diagram schematically showing an example of a refrigeration cycle of an air conditioner S4 according to a fourth embodiment of the present invention. As shown in fig. 5, the basic refrigeration cycle of the air conditioner S4 of the fourth embodiment has substantially the same configuration as the refrigeration cycle of the air conditioner S3 of the third embodiment shown in fig. 4, but differs therefrom in the following points.

That is, the refrigerant on-off

valves

71, 72, and 73 are provided on the

indoor heat exchangers

51 and 52 or the hot water supply heat exchanger 61 side outside the branch tank 100 in the air conditioner S3 of the third embodiment, but are provided in the branch tank 100 in the air conditioner S4 of the fourth embodiment.

Except for these, the air conditioner S4 of the fourth embodiment is the same as the air conditioner S3 of the third embodiment, and therefore, the operation mode in the air conditioner S4 and the control operation in the operation mode will not be described.

Therefore, the same effect as that of the air conditioner S3 of the third embodiment can be obtained from the air conditioner S4 of the fourth embodiment. In addition, in the air conditioner S4, since the refrigerant on-off

valves

71, 72, 73 are provided in the branch tank 100, even when the hot-water supply heat exchanger 61 is newly added, it is not necessary to determine whether or not the refrigerant on-off

valves

71, 72 should be newly added to the already-provided

indoor heat exchangers

51, 52. This can shorten the work time at the site including the additional installation of the hot water supply system of the hot water supply heat exchanger 61.

Description of the symbols

10-compressor, 20-refrigerant switching valve (refrigerant switching section), 21-switching main valve, 30-outdoor heat exchanger, 31-outdoor blower, 31 a-flow direction of outdoor air, 41, 42-refrigerant regulating valve (first refrigerant regulating valve), 43-refrigerant regulating valve (second refrigerant regulating valve), 51, 52-indoor heat exchanger, 60-hot water supply tank (tank), 61-hot water supply heat exchanger, 71, 72-refrigerant opening and closing valve (first refrigerant opening and closing valve), 73-refrigerant opening and closing valve (second refrigerant opening and closing valve), 81, 83-connecting valve (second connecting valve), 82, 84-connecting valve (first connecting valve), 85-connecting valve (fourth connecting valve), 86-connecting valve (third connecting valve), 81 a-88 a-connecting valve, 90-control section, 91-discharge temperature detector, 92-outdoor air temperature detector, 93-outdoor heat exchanger temperature detector, 94-tank temperature detector (tank temperature detector), 100-branch tank, a-d-port of refrigerant switching valve, S1-S4-air conditioner.

Claims

1. An air conditioner is characterized in that,

the disclosed device is provided with:

a compressor for compressing a refrigerant;

an outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air;

an indoor heat exchanger for exchanging heat between the refrigerant and indoor air;

a hot water supply heat exchanger for exchanging heat between the refrigerant and tank water stored in the tank;

a refrigerant switching unit that switches a flow direction of the refrigerant flowing through a refrigerant pipe connecting the compressor, the indoor heat exchanger, and the hot water supply heat exchanger;

a first connection valve for connecting refrigerant pipes provided in a first refrigerant pipe connecting the refrigerant switching unit and the indoor heat exchanger;

a second connection valve for connecting refrigerant pipes provided in a second refrigerant pipe connecting the outdoor heat exchanger and the indoor heat exchanger;

a third connection valve for connecting the refrigerant pipe provided in a third refrigerant pipe connecting the refrigerant switching unit and the hot water supply heat exchanger;

a fourth connection valve for connecting refrigerant pipes provided in a fourth refrigerant pipe connecting the outdoor heat exchanger and the hot water supply heat exchanger;

a first refrigerant opening/closing valve for opening/closing a refrigerant flow path between the first connection valve and the indoor heat exchanger, the first refrigerant opening/closing valve being provided in the first refrigerant pipe;

a second refrigerant opening/closing valve for opening/closing a refrigerant flow path between the third connecting valve provided in the third refrigerant pipe and the hot water supply heat exchanger;

a first refrigerant regulating valve provided in the second refrigerant pipe and functioning as an expansion valve for expanding a refrigerant; and

a second refrigerant regulating valve provided in the fourth refrigerant pipe and functioning as an expansion valve for expanding the refrigerant,

further comprising a controller for controlling the compressor, the outdoor heat exchanger, the refrigerant switching unit, the indoor heat exchanger, the hot water supply heat exchanger, the first refrigerant opening/closing valve, the second refrigerant opening/closing valve, the first refrigerant regulating valve, and the second refrigerant regulating valve,

the control unit performs the following control: in the air-cooling operation for cooling the room in which the indoor heat exchanger is provided, the compressor and the outdoor heat exchanger are operated, the refrigerant flow direction is set so that the refrigerant heated by the compressor is supplied to the indoor heat exchanger by the refrigerant switching unit, the indoor heat exchanger is turned on, the hot-water supply heat exchanger is turned off, the first refrigerant on-off valve and the second refrigerant on-off valve are opened, the opening degree of the first refrigerant regulating valve is controlled, and the second refrigerant regulating valve is closed.

2. The air conditioner according to claim 1,

the control unit performs the following control: when the boiling operation of the hot-water supply heat exchanger is started during the cooling operation, the indoor heat exchanger is turned off, the hot-water supply heat exchanger is turned on, the flow direction of the refrigerant in the refrigerant switching unit is switched to the opposite direction, the first refrigerant on-off valve is closed, the second refrigerant on-off valve is opened, the first refrigerant regulating valve is opened, and the opening degree of the second refrigerant regulating valve is controlled.

3. The air conditioner according to claim 2,

further comprises a tank temperature detecting part for detecting the temperature of the tank water stored in the tank,

the control unit performs the following control: even if a predetermined time or more has elapsed after the start of the boiling operation of the hot-water supply heat exchanger, the boiling operation of the hot-water supply heat exchanger is stopped and the cooling operation is resumed when the tank detected temperature detected by the tank temperature detector has not reached a predetermined target boiling temperature.

4. The air conditioner according to claim 2,

further comprises a heating means different from the hot water supply heat exchanger for heating the tank water stored in the tank,

the control unit performs the following control: when the boiling operation of the hot water supply heat exchanger is stopped before the temperature of the tank water reaches a predetermined target boiling temperature, the tank water is heated by the heating means until the temperature of the tank water reaches the target boiling temperature.