EP3611439B1

EP3611439B1 - Air conditioner

Info

Publication number: EP3611439B1
Application number: EP17905581.9A
Authority: EP
Inventors: Norio Takahashi; Masahiko Watanabe; Hideki Terauchi; Masatoshi Murawaka; Tomonaga Watanabe
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: 2023-08-02
Anticipated expiration: 2037-10-30
Also published as: CN110050162B; WO2018189942A1; JP6667719B2; CN110050162A; EP3611439A1; JPWO2018189942A1; EP3611439A4; MY191401A

Description

TECHNICAL FIELD

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

BACKGROUND ART

An air-conditioner is configured of an indoor unit installed in a room to be air-conditioned, and an outdoor unit installed outdoors. With regard to such air-conditioners, the space available for installing the outdoor unit, in particular, is becoming smaller. Thus, in many of the recent air-conditioners, two or more indoor units are connected to a single outdoor unit. Such air-conditioners are often referred to as a multi-type air-conditioner.
Generally, the cooling operation and heating operation of an indoor unit of an air-conditioner are realized by reversing the flow of refrigerant supplied from the outdoor unit to the indoor unit, by means of a four-way valve or the like. Accordingly, in the general refrigeration cycle configuration of a multi-type air-conditioner in which a plurality of indoor units are connected to a single outdoor unit, the plurality of indoor units are either all configured to perform cooling operation or all configured to perform heating operation.
In recent years, as part of measures against global warming, hot-water supply systems (or hot-water systems) in which a refrigeration cycle similar to that of air-conditioners is adopted have become more common. Such a hot-water supply system heats water to make hot water. Accordingly, the hot-water supply system needs to function as a heating system, as it were, throughout the year, whether it is winter or summer.
When the hot-water supply system is incorporated into a multi-type air-conditioner, it is necessary, particularly in summer, to cause some of the indoor units to function as a cooling system and some of the indoor units as a hot-water supply system (i.e., as a heating system). Accordingly, in the multi-type air-conditioner, it is not possible to incorporate the hot-water supply system as a simple replacement for an indoor unit. Incorporating the hot-water supply system into the multi-type air-conditioner requires making various adjustments in the configuration of the refrigeration cycle, for example. The simple replacement for an indoor unit means being able to connect, to the refrigerant pipes for connection of an indoor unit for indoor air-conditioning, the refrigerant pipes of a hot-water supply system in exactly the same way as the indoor unit for indoor air-conditioning.
For example, Fig. 1 of Patent Literature 1 discloses the example of a hot-water supply air-conditioner 1a configured such that the refrigerant from an outdoor unit 10 is separated by a flow-dividing unit 20a into a refrigerant pipe connected to an indoor unit 30 and a refrigerant pipe connected to a hot-water storage tank 40. Fig. 2 of Patent Literature 2 discloses the example of a hot-water supply air-condition system SS configured such that a gas refrigerant pipe emerging from an outdoor unit 1 is separated into a discharge gas pipe 35 connected to a hot-water supply unit 3 and a gas pipe 36 connected to an indoor unit 2. Patent Literature 3 discloses an air-conditioning hot-water supply combined system according to the preamble of claim 1, when the capacity of a heat source unit is exceeded, suspension of a running indoor unit is performed until the capacity of the heat source unit becomes satisfied, and the performance of the heat source unit is allocated to the hot-water supply unit having submitted the request.

CITATION LIST

PATENT LITERATURE

Patent Literature 1: JP 2011 163654 A
Patent Literature 2: JP 2013 130344 A
Patent Literature 3: EP 2 781 848 A1

DISCLOSURE OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

In the hot-water supply air-conditioner 1a disclosed in Patent Literature 1, in order to connect the hot-water supply system (hot-water storage tank 40) to the outdoor unit 10, it is necessary to newly add the flow-dividing unit 20a. According to the configuration of the outdoor unit 1 disclosed in Patent Literature 2, the discharge gas pipe 35 connected to the hot-water supply unit 3 and the gas pipe 36 connected to the indoor unit 2 are separately prepared, and the configuration is different from the configuration of the outdoor unit of a general multi-type air-conditioner. Thus, according to the technology disclosed in Patent Literature 2, it is not possible to add a hot-water supply system in the form of a simple replacement for the outdoor unit of a general multi-type air-conditioner. Accordingly, the conventional technologies have the problem that it is impossible to incorporate easily into a multi-type air-conditioner a hot-water supply system in the form of a simple replacement for an indoor unit.
In view of the problem of the conventional technologies, an object of the present invention is to provide a multi-type air-conditioner in which a plurality of indoor units are connected to a single outdoor unit, the air-conditioner making it possible to connect a hot-water supply system as a simple replacement for an indoor unit.

SOLUTIONS TO THE PROBLEMS

An air-conditioner according to the present invention includes the technical features of claim 1. Preferred embodiments of the invention are provided in the dependent claims.

EFFECTS OF THE INVENTION

According to the present invention, it is possible to connect a hot-water supply system as a simple replacement for an indoor unit in a multi-type air-conditioner.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a diagram schematically depicting an example of the refrigeration cycle of an air-conditioner according to a first embodiment.
Fig. 2 is a diagram illustrating an example of open-close control of a switching main valve, refrigerant on-off valves, and refrigerant adjustment valves in each operation mode of the air-conditioner according to the first embodiment.
Fig. 3 is a diagram schematically depicting an example of the refrigeration cycle of an air-conditioner according to a second embodiment.
Fig. 4 is a diagram schematically depicting an example of the refrigeration cycle of an air-conditioner according to a third embodiment.
Fig. 5 is a diagram schematically depicting an example of the refrigeration cycle of an air-conditioner according to a fourth embodiment.

DESCRIPTION OF THE EMBODIMENTS

In the following, modes (hereafter referred to as "embodiments") for carrying out the present invention will be described in detail with reference made to the drawings, as appropriate. In the drawing figures, common portions are designated with identical signs, and redundant descriptions are omitted.

«First embodiment»

Fig. 1 is a diagram schematically depicting an example of the refrigeration cycle of an air-conditioner S1 according to a first embodiment of the present invention. As depicted in Fig. 1, the air-conditioner S1 is configured of: a compressor 10; a refrigerant switching part 20; an outdoor heat exchanger 30; an outdoor air blower 31; refrigerant adjustment valves 41 to 43; indoor heat exchangers 51, 52; a hot-water supply tank 60; a hot-water supply heat exchanger 61; refrigerant on-off valves 71 to 73; connecting valves 81 to 86; a controller 90; and temperature detectors 91 to 94. In the figure, the solid lines interconnecting the constituent elements indicate the refrigerant pipes serving as refrigerant flow paths (the same applies to Fig. 3 and subsequent figures).
The air-conditioner S1 depicted in Fig. 1 is a so-called multi-type air-conditioner provided with a plurality of indoor units (indoor heat exchangers 51, 52) with respect to a single outdoor unit (outdoor heat exchanger 30).
In the air-conditioner S1, the compressor 10 suctions refrigerant from a suction part, and discharges a high-temperature and high-pressure refrigerant from a discharge part. The suction part of the compressor 10 (in Fig. 1, a refrigerant pipe-connecting part to the left of the compressor 10) is connected to a port d of the refrigerant switching part 20 via a refrigerant pipe. The discharge part of the compressor 10 (in Fig. 1, a refrigerant pipe-connecting part on the lower side of the compressor 10) is connected to a port a of the refrigerant switching part 20 via a refrigerant pipe. The discharge part of the compressor 10 has a discharge temperature detector 91 for detecting the temperature (discharge temperature) of the refrigerant discharged from the compressor 10. A detection signal obtained by the discharge temperature detector 91 is input to the controller 90. The controller 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 part 20 is a four-way valve provided with a switching main valve 21 and four ports a to d which are refrigerant pipe-connecting parts. As the refrigerant switching part 20, it is possible to use, for example, an electromagnetic valve (a so-called latch-type electromagnetic valve) configured to switch the connection relationships of the ports a to d by sliding the switching main valve 21 by energization control or the like. Specifically, when the switching main valve 21 is at the position indicated by solid line in Fig. 1, port a and port b are connected, and port c and port d are connected. When the switching main valve 21 is at the position indicated by dashed line in Fig. 1, port a and port c are connected, and port b and port d are connected. The connection relationships of the ports a to d in the refrigerant switching part 20, i.e., the position of the switching main valve 21, are controlled by the controller 90.
The outdoor heat exchanger 30 constitutes a part of the outdoor unit of the air-conditioner S1, and performs heat exchange between the refrigerant that flows in and the outdoor air. One refrigerant pipe-connecting part of the outdoor heat exchanger 30 (in Fig. 1, the refrigerant pipe-connecting part on the upper side of the outdoor heat exchanger 30) is connected to the port b of the refrigerant switching part 20 via a refrigerant pipe. The other refrigerant pipe-connecting part of the outdoor heat exchanger 30 (in Fig. 1, the refrigerant pipe-connecting part on the lower side of the outdoor heat exchanger 30) is connected to the refrigerant adjustment valves 41 to 43 via a refrigerant pipe having branches.
The outdoor unit of the air-conditioner S1 is also provided with the outdoor air blower 31 for promoting heat exchange between the refrigerant in the outdoor heat exchanger 30 and the outdoor air. The amount of air blown by the outdoor air blower 31 (rotational speed) is controlled by the controller 90. In the vicinity of the suction opening of the outdoor air blower 31 (the upstream side in the flow direction 31a of the outdoor air for the outdoor heat exchanger 30), an outdoor-air temperature detector 92 for detecting the outdoor-air temperature is disposed. The outdoor heat exchanger 30 is also provided with an outdoor heat exchanger temperature detector 93 for detecting the temperature of the outdoor heat exchanger 30. Detection signals obtained by the outdoor-air temperature detector 92 and the outdoor heat exchanger temperature detector 93 are input to the controller 90.
The refrigerant adjustment valves 41 to 43 are valves configured for opening and closing and opening-degree control. One refrigerant pipe-connecting part of the refrigerant adjustment valves 41 to 43 (in Fig. 1, the refrigerant pipe-connecting part to the left of the refrigerant adjustment valves 41 to 43) is connected to the outdoor heat exchanger 30 via refrigerant pipes. The other refrigerant pipe-connecting part of the refrigerant adjustment valves 41, 42 (in Fig. 1, the refrigerant pipe-connecting part on the lower side of the refrigerant adjustment valves 41, 42) is connected through the connecting valves 81, 83 to the indoor heat exchangers 51, 52 via refrigerant pipes. The other refrigerant pipe-connecting part of the refrigerant adjustment valve 43 (in Fig. 1, the refrigerant pipe-connecting part on the lower side of the refrigerant adjustment valve 43) is connected through the connecting valve 85 to the hot-water supply heat exchanger 61 of the hot-water supply tank 60, via a refrigerant pipe. The opening and closing and the opening degree of the refrigerant adjustment valves 41 to 43 are controlled by the controller 90.
The indoor heat exchangers 51, 52 constitute part of the indoor unit of the air-conditioner S1, and perform heat exchange between the refrigerant that flows in and the indoor air. One refrigerant pipe-connecting part of the indoor heat exchangers 51, 52 (in Fig. 1, the refrigerant pipe-connecting part to the upper-left of the indoor heat exchangers 51, 52) is connected through the connecting valves 81, 83 to the refrigerant adjustment valves 41, 42 via refrigerant pipes. One refrigerant pipe-connecting part of the hot-water supply heat exchanger 61 of the hot-water supply tank 60 (in Fig. 1, the refrigerant pipe-connecting part to the upper-left of the hot-water supply heat exchanger 61) is connected through the connecting valve 85 to the refrigerant adjustment valve 43 via a refrigerant pipe.
The other refrigerant pipe-connecting part of the indoor heat exchangers 51, 52 (in Fig. 1, the refrigerant pipe-connecting part to the lower-left of the indoor heat exchangers 51, 52) is connected through the refrigerant on-off valves 71, 72 and connecting valves 82, 84 to the port c of the refrigerant switching part 20 via refrigerant pipes. The other refrigerant pipe-connecting part of the hot-water supply heat exchanger 61 of the hot-water supply tank 60 (in Fig. 1, the refrigerant pipe-connecting part to the lower-left of the hot-water supply heat exchanger 61) is connected through the refrigerant on-off valve 73 and the connecting valve 86 to the port c of the refrigerant switching part 20 via a refrigerant pipe.
While omitted in Fig. 1, each of the indoor units is provided with a fan for taking indoor air into the housing of the indoor unit and for blowing out indoors the air heat-exchanged (air-conditioned) by the indoor heat exchangers 51, 52.
The air-conditioner S1 is further provided with the hot-water supply tank 60 having the hot-water supply heat exchanger 61. In the hot-water supply tank 60, tank water (heated water) is stored. The hot-water supply heat exchanger 61 exchanges heat between high-temperature refrigerant and the tank water to heat the tank water. In this case, the hot-water supply tank 60 is configured such that, for example, tap water is caused to flow in from the lower side of the hot-water supply tank 60 to push up the internal tank water, thus supplying the heated water to a hot-water supply terminal (such as a tap) directly from the upper side of the hot-water supply tank 60. The tank water is not limited to heated water.
As described above, one refrigerant pipe-connecting part of the hot-water supply heat exchanger 61 is connected through the connecting valve 85 to the refrigerant adjustment valve 43 via a refrigerant pipe. The other refrigerant pipe-connecting part of the hot-water supply heat exchanger 61 is connected through the refrigerant on-off valve 73 and the connecting valve 86 to the port c of the refrigerant switching part 20, via a refrigerant pipe. In the hot-water supply tank 60, the tank temperature detector 94 is disposed to detect the temperature of the stored tank water. A detection signal obtained by the tank temperature detector 94 is input to the controller 90.
In the example of Fig. 1, the hot-water supply heat exchanger 61 is configured of a refrigerant pipe wound in contact with the outer periphery of a 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 heat-insulating material, which is not depicted. Accordingly, the refrigerant that flows into the hot-water supply heat exchanger 61 can be heat-exchanged with the tank water stored in the hot-water supply tank 60, via 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 depicted in the example of Fig. 1. For example, the refrigerant pipe of the hot-water supply heat exchanger 61 may penetrate into the container of the hot-water supply tank 60 from the side of the container, so that the refrigerant pipe is arranged in the container of the hot-water supply tank 60. In this case, the refrigerant that flows into the hot-water supply heat exchanger 61 can be subjected to heat exchange, via the refrigerant pipe of the hot-water supply heat exchanger 61, with the tank water stored in the hot-water supply tank 60. The refrigerant pipe arranged in 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, a configuration may be provided with: the hot-water supply heat exchanger 61 as a separate body from the hot-water supply tank 60; a flow path for allowing tank water that flows out of the lower part of the hot-water supply tank 60 to flow to the upper part of the hot-water supply tank 60 via the hot-water supply heat exchanger 61; and a pump disposed on the flow path.
As depicted in Fig. 1, in the air-conditioner S1 according to the first embodiment, the refrigerant pipe connected to the port c of the refrigerant switching part 20 is branched midway therealong into a plurality of refrigerant pipes. The branched refrigerant pipes are respectively connected to the indoor heat exchangers 51, 52 and the hot-water supply heat exchanger 61. On the respective branched refrigerant pipes (hereafter referred to as first branched refrigerant pipes), the connecting valves 82, 84, 86 are disposed. Further, on portions of the first branched refrigerant pipes that connect the connecting valves 82, 84, 86 and the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61, the refrigerant on-off valves 71, 72, 73 are disposed.
Similarly, the refrigerant pipe connected to one refrigerant pipe-connecting part of the outdoor heat exchanger 30 (in Fig. 1, the refrigerant pipe-connecting part on the lower side of the outdoor heat exchanger 30) is branched midway therealong into a plurality of refrigerant pipes, and the branched refrigerant pipes are respectively connected to the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61. On the respective branched refrigerant pipes (hereafter referred to as second branched refrigerant pipes), the connecting valves 81, 83, 85 are disposed. Further, on the respective second branched refrigerant pipes, at positions closer to the outdoor heat exchanger 30 than the positions at which the connecting valves 81, 83, 85 are disposed, the refrigerant adjustment valves 41, 42, 43 are disposed.
Accordingly, the connecting valves 81 to 86 may be considered the connection portions of the refrigerant pipes at which the outdoor unit of the air-conditioner S1 (including the compressor 10, the outdoor heat exchanger 30, and the refrigerant switching part 20) and the indoor units thereof (including the indoor heat exchangers 51, 52, and the hot-water supply tank 60) are divided. Thus, in the first embodiment, it is possible to connect the indoor units including the indoor heat exchangers 51, 52 and the hot-water supply system including the hot-water supply heat exchanger 61 to the outdoor unit via the connecting valves 81 to 86 in exactly the same way.
That is, in the first embodiment, it is possible to connect the respective refrigerant pipes connected to the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61 to any of the sets of the connecting valves (81, 82), (83, 84), (85, 86) in exactly the same way. In other words, in the multi-type air-conditioner S1 of the first embodiment, it is possible to connect the hot-water supply system provided with the hot-water supply heat exchanger 61 as a simple replacement for the indoor units provided with the indoor heat exchangers 51, 52.
Further, in the first embodiment, the refrigerant adjustment valves 41 to 43 are arranged at positions, on the respective refrigerant pipes connected to the indoor units 51, 52 or the hot-water supply heat exchanger 61, which are at a greater distance from the indoor units 51, 52 or the hot-water supply heat exchanger 61 than the connecting valves 81, 83, 85. In other words, the refrigerant adjustment valves 41 to 43 are disposed on the outdoor unit side. However, the positions at which the refrigerant adjustment valves 41 to 43 are disposed are not limited to the outdoor unit side, and the refrigerant adjustment valves 41 to 43 may be disposed on the indoor unit side. That is, the refrigerant adjustment valves 41 to 43 may be disposed at positions, on the respective refrigerant pipes connected to the indoor units 51, 52 or the hot-water supply heat exchanger 61, which are at a smaller distance from the indoor units 51, 52 or the hot-water supply heat exchanger 61 than the connecting valves 81, 83, 85.
The refrigerant on-off valves 71 to 73, which would not be required in a general multi-type air-conditioner, are introduced into the first embodiment due to the involvement of the hot-water supply system provided with the hot-water supply heat exchanger 61. However, due to the configuration in which the refrigerant on-off valves 71 to 73 are connected to the connecting valves 82, 84, 86, the refrigerant on-off valves 71 to 73 can be attached easily even if a general indoor unit is used. Thus, it is easy to adopt a configuration provided with the refrigerant on-off valves 71 to 73 when the hot-water supply heat exchanger 61 is connected to any of the sets of the connecting valves (81, 82), (83, 84), (85, 86), or, when not connected to any thereof, to adopt a configuration not provided with the refrigerant on-off valves 71 to 73.
The details of various operations of the air-conditioner S1 will be described with reference to Fig. 1 and Fig. 2. Fig. 2 is a diagram illustrating an example of open-close control of the switching main valve 21, the refrigerant on-off valves 71 to 73, and the refrigerant adjustment valves 41 to 43 in each operation mode of the air-conditioner S1 according to the first embodiment. In Fig. 1, the solid line arrows shown next to the refrigerant pipes indicate the direction of flow of refrigerant during cooling operation, for example. The dashed line arrows indicate the direction of flow of refrigerant during heating operation, for example.
As depicted in Fig. 2, the air-conditioner S1 basically has three operation modes: a cooling operation for cooling indoors; a heating operation for heating indoors; and a boiling-up operation for heating the tank water in the hot-water supply tank 60. More specifically, the cooling operation includes a boiling-up preferred cooling operation for heating the tank water during cooling operation, and the heating operation includes a heating/boiling-up operation (in the figure, the boiling-up preferred heating operation) for heating the tank water during heating operation. The heating operation also includes a normal defrosting operation for removing frost that has become attached to the outdoor heat exchanger 30 during heating operation, a comfortable defrosting operation, and a rapid defrosting operation. The boiling-up operation includes a similar comfortable defrosting operation.
The operation modes are set by a user or an administrator of the air-conditioner S1, using a control panel connected to the controller 90 or a remote controller. The controller 90, in accordance with the operation mode that has been set, controls the opening and closing of the switching main valve 21, the refrigerant adjustment valves 41 to 43, and the refrigerant on-off valves 71 to 73.

When the indoor heat exchangers 51, 52 are turned ON for cooling and the hot-water supply heat exchanger 61 is OFF, the controller 90 sets the air-conditioner S1 for the cooling operation mode. Then, the controller 90 operates the compressor 10 and the outdoor air blower 31, and sets the switching main valve 21 of the refrigerant switching part 20 at the position indicated by solid line in Fig. 1. Further, the controller 90 opens the refrigerant on-off valves 71 to 73, closes the refrigerant adjustment valve 43, and subjects the refrigerant adjustment valves 41, 42 to opening-degree control.
While it is herein assumed that both of the indoor heat exchangers 51, 52 are turned ON for cooling, the controller 90 also sets the cooling operation mode for the air-conditioner S1 when one of the indoor heat exchangers 51, 52 is turned ON for cooling and the hot-water supply heat exchanger 61 is OFF. In this case, however, one of the refrigerant adjustment valves 41, 42 that is connected to one of the indoor heat exchangers 51, 52 that is not turned ON for cooling is closed. Such situation may occur not only during cooling operation but also during cooling operation. However, in order to avoid complicating the description, it will be assumed in the following description that the indoor heat exchangers 51, 52 are both turned ON for cooling or OFF for cooling, or both turned ON for heating or OFF for heating.
In the cooling operation, a high-temperature and high-pressure refrigerant discharged from the compressor 10 flows through the ports a, b of the refrigerant switching part 20 into the outdoor heat exchanger 30 functioning as a condenser, and releases heat by exchanging heat with the outdoor air. The refrigerant that has released heat and become liquefied in the outdoor heat exchanger 30 flows into the refrigerant adjustment valves 41, 42 functioning as expansion valves, is decompressed, becomes a low-temperature and low-pressure gas-liquid mixture refrigerant, and absorbs heat by exchanging heat with the indoor air in the indoor heat exchangers 51, 52 functioning as evaporators. Then, the indoor air of which the heat has been absorbed by the refrigerant and the temperature has decreased is blown indoors out of the indoor units, thus cooling indoors. The refrigerant that has absorbed heat and become evaporated in the indoor heat exchangers 51, 52 is suctioned into the compressor 10 through the ports c, d of the refrigerant switching part 20.
The air-conditioner S1 through the above cooling operation can cool the rooms in which the indoor units (the indoor heat exchangers 51, 52) are installed.

<Boiling-up preferred cooling operation>

During cooling operation, when the hot-water supply heat exchanger 61 is turned ON, the controller 90 sets the air-conditioner S1 for the boiling-up preferred cooling operation mode. Then, the controller 90 turns OFF the indoor heat exchangers 51, 52 into a standby state, sets the switching main valve 21 of the refrigerant switching part 20 at the position indicated by dashed line in Fig. 1, and opens the refrigerant on-off valve 73. In this case, the refrigerant of which the temperature and pressure have been increased by the compressor 10 flows through the refrigerant on-off valve 73 into the hot-water supply heat exchanger 61, heats and turns the tank water in the hot-water supply tank 60 into hot water, and becomes liquefied. Thereafter, the refrigerant is decompressed by the opening-degree control of the refrigerant adjustment valve 43, flows into the outdoor heat exchanger 30, and becomes evaporated by absorbing heat.
Because the refrigerant on-off valves 71, 72 are now closed, the high-temperature refrigerant does not flow into the indoor heat exchangers 51, 52. Thus, it is possible to suppress the adverse effect (indoor temperature increase) of the tank water boiling-up operation on indoor cooling. In addition, because the refrigerant adjustment valves 41, 42 are open during the operation, it is possible to use the refrigerant for the hot-water supply heat exchanger 61 effectively.
Generally, it is considered that the temperature variation range for indoor cooling is on the order of 27 to 35°C, and the temperature variation range for server room cooling is on the order of 8 to 10°C. The temperature variation range for indoor heating is considered to be on the order of 0 to 20°C. In each case, the temperature variation range is not more than 30°C. Meanwhile, the temperature variation range of the tank water in the hot-water supply tank 60 is 0 to 55°C, for example, and is significantly wider than those for indoor cooling and indoor heating. Thus, during the boiling-up operation in which the tank water in the hot-water supply tank 60 is heated, the controller 90 sets the discharge target temperature of the compressor 10 higher than during cooling operation or heating operation.
When the temperature of the tank water in the hot-water supply tank 60 has reached a predetermined target boiling-up temperature due to the control of the boiling-up preferred cooling operation, the controller 90 stops the control of the boiling-up operation, causes the indoor heat exchangers 51, 52 to come out of standby, and return to the control of normal cooling operation.
While detailed descriptions are omitted, during the boiling-up preferred cooling operation, air-conditioning for cooling is substantially stopped, and, consequently, indoor comfortableness may be decreased. Thus, in order to prevent indoor comfortableness from being deteriorated, an upper-limit time for boiling-up operation may be provided, and the boiling-up operation may be stopped if the tank water temperature does not reach the predetermined target boiling-up temperature even after the upper-limit time has been exceeded. When the boiling-up operation has been stopped, the cooling operation is resumed. To prepare for the stoppage of the boiling-up operation, the hot-water supply tank 60 may be provided with an auxiliary heater (heating means), so that the boiling-up of the tank water can be taken over by energizing the auxiliary heater.
Thus, with the air-conditioner S1 according to the first embodiment, it is possible to perform the boiling-up operation while suppressing the influence on cooling operation and indoor comfortableness.

When the indoor heat exchangers 51, 52 are turned ON for heating and the hot-water supply heat exchanger 61 is OFF, the controller 90 sets the air-conditioner S1 for the heating operation mode. Then, the controller 90 operates the compressor 10 and the outdoor air blower 31, and sets the switching main valve 21 of the refrigerant switching part 20 at the position indicated by dashed line in Fig. 1. Further, the controller 90 opens the refrigerant on-off valves 71, 72, closes the refrigerant on-off valve 73, subjects the refrigerant adjustment valves 41, 42 to opening-degree control, and opens the refrigerant adjustment valve 43.
During the heating operation, the high-temperature and high-pressure refrigerant discharged from the compressor 10 flows through the ports a, c of the refrigerant switching part 20 into the indoor heat exchangers 51, 52 functioning as condensers, becomes liquefied by exchanging heat with the indoor air, and releases heat. Then, the indoor air of which the temperature has been increased with the heat released from the refrigerant is blown out indoors from the indoor units, thus heating the inside of the rooms. The refrigerant that has released heat in the indoor heat exchangers 51, 52 flows into the refrigerant adjustment valves 41, 42 functioning as expansion valves, becomes a low-temperature and low-pressure gas-liquid mixture refrigerant, and becomes evaporated by absorbing heat by exchanging heat with the outdoor air in the outdoor heat exchanger 30 functioning as an evaporator. Further, the refrigerant that has absorbed heat and become evaporated in the outdoor heat exchanger 30 is suctioned into the compressor 10 through the ports b, d of the refrigerant switching part 20.
Thus, the air-conditioner S1 according to the first embodiment, by performing the heating operation, can heat the inside of the rooms in which the indoor units (indoor heat exchangers 51, 52) are installed.

(Modification of heating operation)

Generally, at the start of heating operation, the discharge temperature of the compressor 10 is low, and therefore the temperature of the refrigerant supplied to the indoor heat exchangers 51, 52 is low. Thus, at the start of heating operation, the heating capacity of the air-conditioner S1 is in low state. Accordingly, in the present modification, if at the start of heating operation the temperature of the tank water in the hot-water supply tank 60 (the temperature detected by the tank temperature detector 94) is higher than or equal to a predetermined first tank water temperature (such as 15°C), the controller 90 opens the refrigerant on-off valve 73, and subjects the refrigerant adjustment valve 43 to opening-degree control.
In this case, at least a part (or, optionally, all) of the refrigerant discharged from the compressor 10 flows through the hot-water supply heat exchanger 61. In other words, the refrigerant can be warmed with the heat of the tank water in the hot-water supply tank 60. Accordingly, it is possible to increase the temperature of the refrigerant supplied to the indoor heat exchangers 51, 52 quickly, and to provide the air-conditioner S1 having a good response to a request for heating operation from the user.
During the heating operation, when the temperature of the refrigerant discharged from the compressor 10 (the temperature detected by the discharge temperature detector 91) has become greater than or equal to a predetermined discharge temperature (such as 20°C), the controller 90 may transition to the normal heating operation in which the refrigerant on-off valve 73 is closed and the refrigerant adjustment valve 43 is opened.
After the indoor temperature has become a predetermined set room temperature, if the temperature of the tank water in the hot-water supply tank 60 (the temperature detected by the tank temperature detector 94) is greater than or equal to a predetermined second tank water temperature (for example, 40°C, or a temperature higher than the set room temperature), the controller 90 may implement the following control. That is, the controller 90 implements control to: stop the compressor 10 and the outdoor air blower 31; set the switching main valve 21 of the refrigerant switching part 20 at the position indicated by dashed line in Fig. 1; close the refrigerant adjustment valves 41 to 43; and open the refrigerant on-off valve 71 to 72.
When such control is performed, the flow of refrigerant in the refrigerant pipes is stopped. However, the refrigerant pipe extending from the hot-water supply heat exchanger 61 to the port c of the refrigerant switching part 20 via the connecting valve 86, and the refrigerant pipes extending from the indoor heat exchangers 51, 52 to the port c of the refrigerant switching part 20 via the connecting valves 82, 84 are placed in a thermally connected state. That is, the heat of the tank water in the hot-water supply tank 60 is supplied to the indoor heat exchangers 51, 52 due to the natural convection of the refrigerant in the refrigerant pipes and the thermal conduction by the refrigerant pipes. Thus, it is possible to suppress a decrease in the temperature of the inside of the rooms to be heated.

During the heating/boiling-up operation, the controller 90 operates the compressor 10 and the outdoor air blower 31, sets the switching main valve 21 of the refrigerant switching part 20 at the position indicated by dashed line in Fig. 1, opens the refrigerant on-off valves 71 to 73, and subjects the refrigerant adjustment valves 41 to 43 to opening-degree control.
The high-temperature and high-pressure refrigerant discharged from the compressor 10 flows through the ports a, c of the refrigerant switching part 20 and the refrigerant on-off valve 73 into the hot-water supply heat exchanger 61 functioning as a condenser, and releases heat by exchanging heat with the tank water in the hot-water supply tank 60. Then, the tank water in the hot-water supply tank 60 is heated (boiled-up) 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, 52 functioning as high-temperature and high-pressure refrigerant the condensers, and releases heat by exchanging heat with the indoor air. Then, the indoor air of which the temperature has been increased with the heat released from the refrigerant is blown out indoors from the indoor units, whereby the inside of the rooms is air-conditioned (heated). The refrigerant that has released heat and become liquefied in the hot-water supply heat exchanger 61 and the indoor heat exchangers 51, 52 flows into the refrigerant adjustment valves 41 to 43 functioning as expansion valves, becomes a low-temperature and low-pressure refrigerant, and becomes evaporated by absorbing heat by exchanging heat with the outdoor air in the outdoor heat exchanger 30 functioning as an evaporator. The refrigerant that has absorbed heat and become evaporated in the outdoor heat exchanger 30 is suctioned into the compressor 10 via the ports b, d of the refrigerant switching part 20.
Thus, the air-conditioner S1 according to the first embodiment, by performing the heating/boiling-up operation, can heat the inside of the rooms in which the indoor units (indoor heat exchangers 51, 52) are installed, and boil-up the tank water in the hot-water supply tank 60 using part of condensation heat.
Thereafter, the controller 90, upon receipt of an OFF command for the hot-water supply heat exchanger 61, transitions to the normal heating operation.

<Boiling-up operation>

During the boiling-up operation, the controller 90 operates the compressor 10 and the outdoor air blower 31, and sets the switching main valve 21 of the refrigerant switching part 20 at the position indicated by dashed line in Fig. 1. The controller 90 then closes the refrigerant on-off valves 71, 72, opens the refrigerant adjustment valves 41, 42, opens the refrigerant on-off valve 73, and subjects the refrigerant adjustment valve 43 to opening-degree control.
The high-temperature and high-pressure refrigerant discharged from the compressor 10 flows via the ports a, c of the refrigerant switching part 20 and the refrigerant on-off valve 73 into the hot-water supply heat exchanger 61 functioning as a condenser, and releases heat by exchanging heat with the tank water in the hot-water supply tank 60. Then, the tank water in the hot-water supply tank 60 is heated (boiled-up) by the heat released from the refrigerant. The refrigerant that has released heat in the hot-water supply heat exchanger 61 flows into the refrigerant adjustment valve 43 functioning as an expansion valve, becomes a low-temperature and low-pressure refrigerant, and absorbs heat by exchanging heat with the outdoor air in the outdoor heat exchanger 30 functioning as an evaporator. The refrigerant that has absorbed heat in the outdoor heat exchanger 30 is then suctioned into the compressor 10 via the ports b, d of the refrigerant switching part 20.
During the boiling-up operation, the refrigerant on-off valves 71, 72 are closed so that the refrigerant does not flow into the indoor heat exchangers 51, 52. Thus, an increase in indoor temperature can be suppressed. Further, by opening the refrigerant adjustment valves 41, 42, it is possible to suppress an unwanted accumulation of refrigerant in the indoor heat exchangers 51, 52.
Thus, the air-conditioner S1 according to the first embodiment, by performing the boiling-up operation, can boil up the tank water in the hot-water supply tank 60 without cooling or heating the inside of the rooms.

During the heating operation, the heating/boiling-up operation, and the boiling-up operation, the outdoor heat exchanger 30 functions as an evaporator, whereby the refrigerant absorbs heat and the outdoor air is cooled. Accordingly, when the outdoor-air humidity is high and the outdoor-air temperature is low, frost may become attached to the outdoor heat exchanger 30, resulting in a decrease in the heat exchange performance of the outdoor heat exchanger 30. Thus, the air-conditioner S1 is configured to perform a defrosting operation (defrost operation) to remove the frost that has become attached.
The controller 90, based on the temperature of the outdoor heat exchanger 30 detected by the outdoor-air temperature detector 92 and the outdoor-air temperature detected by the outdoor heat exchanger temperature detector 93, calculates the outdoor dew point, for example, and thereby estimates the amount of frost attached to the outdoor heat exchanger 30. If the estimated amount of attached frost has exceeded a predetermined threshold value of the amount of attached frost, the controller 90 performs the defrosting operation.
The air-conditioner S1 according to the first embodiment is configured to perform three patterns of defrosting operation as described below.

(Normal defrosting operation)

During a normal defrosting operation, the controller 90 operates the compressor 10, sets the switching main valve 21 of the refrigerant switching part 20 at the position indicated by solid line in Fig. 1, opens the refrigerant on-off valves 71, 72 and the refrigerant adjustment valves 41, 42, and closes the refrigerant on-off valve 73 and the refrigerant adjustment valve 43.
The discharge refrigerant discharged from the compressor 10 flows via the ports a, b of the refrigerant switching part 20 into the outdoor heat exchanger 30, and releases heat by exchanging heat with the outdoor air. As the refrigerant releases heat into the outdoor air, the frost that has become attached to the outdoor heat exchanger 30 melts. The refrigerant that has released heat in the outdoor heat exchanger 30 then passes through the refrigerant adjustment valves 41, 42 and absorbs heat by exchanging heat with the indoor air in the indoor heat exchangers 51, 52. As the heat of the indoor air is absorbed, the indoor temperature decreases. The refrigerant that has absorbed heat in the indoor heat exchangers 51, 52 is suctioned into the compressor 10 through the ports c, d of the refrigerant switching part 20.
Thus, the air-conditioner S1 according to the first embodiment, by performing the normal defrosting operation, can remove the frost that has become attached to the outdoor heat exchanger 30.

(Comfortable defrosting operation)

The comfortable defrosting operation is selected when the temperature of the tank water in the hot-water supply tank 60 is greater than or equal to a predetermined temperature (such as 20°C). Alternatively, the comfortable defrosting operation is selected when the tank water temperature is greater than or equal to the discharge temperature of the compressor 10 (the temperature detected by the discharge temperature detector 91). The predetermined temperature herein may have the same value or a different value from the first tank water temperature or the second tank water temperature in the modification of the heating operation.
The comfortable defrosting operation differs from the normal defrosting operation in that the refrigerant discharged from the compressor 10 is caused to flow into the hot-water supply heat exchanger 61 and to not flow into the indoor heat exchangers 51, 52. That is, during comfortable defrosting operation, the controller 90 operates the compressor 10, sets the switching main valve 21 of the refrigerant switching part 20 at the position indicated by solid line in Fig. 1, opens the refrigerant on-off valve 73 and the refrigerant adjustment valve 43, and closes the refrigerant on-off valves 71, 72 and the refrigerant adjustment valves 41, 42.
The discharge refrigerant discharged from the compressor 10 flows via the ports a, b of the refrigerant switching part 20 into the outdoor heat exchanger 30, and releases heat by exchanging heat with the outdoor air. As the refrigerant releases heat into the outdoor air, the frost that has become attached to the outdoor heat exchanger 30 melts. The refrigerant that has released heat in the outdoor heat exchanger 30 then flows via the refrigerant adjustment valve 43 into the hot-water supply heat exchanger 61 functioning as a heat source, and is heated by exchanging heat with the high-temperature tank water in the hot-water supply tank 60. As the heat of the tank water is absorbed, the temperature of the tank water in the hot-water supply tank 60 decreases. The refrigerant heated in the hot-water supply heat exchanger 61 is suctioned into the compressor 10 via the refrigerant on-off valve 73 and the ports c, d of the refrigerant switching part 20.
Thus, the air-conditioner S1 according to the first embodiment, by performing the comfortable defrosting operation, can remove the frost that has become attached to the outdoor heat exchanger 30. During normal defrosting operation, defrosting is performed using indoor heat. On the other hand, during comfortable defrosting operation, defrosting is performed using the heat of the tank water in the hot-water supply tank 60. Accordingly, during comfortable defrosting operation, it is possible to suppress a decrease in indoor temperature more than in the case of normal defrosting operation.

(Rapid defrosting operation)

The rapid defrosting operation is selected when the temperature of the tank water in the hot-water supply tank 60 is greater than or equal to a predetermined temperature (such as 20°C). Alternatively, the rapid defrosting operation is selected when the tank water temperature is greater than or equal to the discharge temperature of the compressor 10 (the temperature detected by the discharge temperature detector 91). The predetermined temperature herein may have the same value or a different value from the first tank water temperature or the second tank water temperature in the modification of the heating operation. It is assumed that whether the comfortable defrosting operation is selected or the rapid defrosting operation is selected is set separately by the user of the air-conditioner S1.
During rapid defrosting operation, the controller 90 operates the compressor 10, sets the switching main valve 21 of the refrigerant switching part 20 at the position indicated by solid line in Fig. 1, opens the refrigerant adjustment valves 41 to 43, and also opens the refrigerant on-off valves 71 to 73.
The high-temperature and high-pressure refrigerant discharged from the compressor 10 flows via the ports a, b of the refrigerant switching part 20 into the outdoor heat exchanger 30, and releases heat by exchanging heat with the outdoor air. As the refrigerant releases heat into the outdoor air, the frost that has become attached to the outdoor heat exchanger 30 melts. The refrigerant that has released heat in the outdoor heat exchanger 30 flows via the refrigerant adjustment valves 41 to 43 into the indoor heat exchangers 51, 52 and the hot-water supply heat exchanger 61, absorbs heat, and is then suctioned into the compressor 10 via the refrigerant on-off valves 71 to 73 and the ports c, d of the refrigerant switching part 20.
Thus, the air-conditioner S1 according to the first embodiment, by performing the rapid defrosting operation, can remove the frost that has become attached to the outdoor heat exchanger 30. During normal defrosting operation, heat is absorbed from the indoor heat exchangers 51, 52. On the other hand, during rapid defrosting operation, heat is also absorbed from the hot-water supply heat exchanger 61. Accordingly, defrosting of the outdoor heat exchanger 30 can be performed in a short time.

Thus, with the air-conditioner S1 according to the first embodiment, it is possible to perform the cooling operation, the heating operation, and the boiling-up operation. In addition, it is possible to boil-up the tank water in the hot-water supply tank 60 even during cooling operation and heating operation (the boiling-up preferred cooling operation and the boiling-up preferred heating operation). Further, with the air-conditioner S1 according to the first embodiment, it is possible to perform a preferable defrosting operation (the normal defrosting operation, the comfortable defrosting operation, or the rapid defrosting operation), as appropriate.
Further, in the air-conditioner S1 according to the first embodiment, the refrigerant pipe connected to the port c of the refrigerant switching part 20 is branched into a plurality of refrigerant pipes, and the branched refrigerant pipes are respectively connected to the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61. The connecting valves 82, 84, 86 are disposed on the respective branched refrigerant pipes (first branched refrigerant pipes). Similarly, the refrigerant pipe connected to one refrigerant pipe-connecting part of the outdoor heat exchanger 30 is branched into a plurality of refrigerant pipes, and the branched refrigerant pipes (first branched refrigerant pipes) are respectively connected to the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61. The connecting valves 81, 83, 85 are disposed on the respective branched refrigerant pipes (second branched refrigerant pipe). Thus, it is possible to connect the refrigerant pipes extending from the side of the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61 to any of the sets of the connecting valves (81, 82), (83, 84), (85, 86) in exactly the same way.

<<Second embodiment>>

Fig. 3 is a diagram schematically depicting an example of the refrigeration cycle of an air-conditioner S2 according to a second embodiment of the present invention. As depicted in Fig. 3, the air-conditioner S2 according to the second embodiment differs from the air-conditioner S1 of the first embodiment in that only two connecting valves 81, 82 are disposed, as opposed to the air-conditioner S1 of the first embodiment in which six connecting valves 81 to 86 are disposed.
That is, in the second embodiment, the connecting valve 82 is disposed on a refrigerant pipe portion (hereafter referred to as a first common refrigerant pipe) ahead of where the refrigerant pipe connected to the port c of the refrigerant switching part 20 is branched into a plurality of refrigerant pipes. Similarly, the connecting valve 81 is disposed on a refrigerant pipe portion (hereafter referred to as a second common refrigerant pipe) ahead of where the refrigerant pipe connected to one refrigerant pipe-connecting part of the outdoor heat exchanger 30 (in Fig. 1, the refrigerant pipe-connecting part on the lower side of the outdoor heat exchanger 30) is branched into a plurality of refrigerant pipes.
In other words, the refrigerant on-off valves 71 to 73 and the refrigerant adjustment valves 41 to 43 are disposed on the side of the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61 with respect to the connecting valves 81, 82. Specifically, the first common refrigerant pipe on which the connecting valve 82 is disposed is branched into a plurality of refrigerant pipes, and the branched refrigerant pipes (hereafter referred to as first branched refrigerant pipes) are respectively connected to the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61. The refrigerant on-off valves 71, 72, 73 are disposed on the respective first branched refrigerant pipes. Similarly, the second common refrigerant pipe on which the connecting valve 81 is disposed is branched into a plurality of refrigerant pipes, and the branched refrigerant pipes (hereafter referred to as second branched refrigerant pipes) are respectively connected to the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61. The refrigerant adjustment valves 41, 42, 43 are respectively disposed on the second branched refrigerant pipes.
With the exception of the above configuration, the configuration of the refrigeration cycle of the air-conditioner S2 according to the second embodiment is the same as the configuration of the refrigeration cycle of the air-conditioner S1 according to the first embodiment. Thus, the air-conditioner S2 according to the second embodiment can be operated in the operation modes similar to those of the first embodiment. That is, the air-conditioner S2 has the three operation modes of the cooling operation, the heating operation, and the boiling-up operation. The cooling operation includes the boiling-up preferred cooling operation. The heating operation includes the boiling-up preferred heating operation, the normal defrosting operation, the comfortable defrosting operation, and the rapid defrosting operation. The boiling-up operation includes the comfortable defrosting operation.
In these operation modes, the open-close control performed by the controller 90 with respect to the switching main valve 21, the refrigerant on-off valves 71 to 73, and the refrigerant adjustment valves 41 to 43 is the same as that illustrated in Fig. 2. Accordingly, herein the description of control operation in each operation mode will be omitted.
Accordingly, with the air-conditioner S2 of the second embodiment, it is also possible to obtain substantially the same effects as those of the air-conditioner S1 of the first embodiment.

<<Third embodiment>>

Fig. 4 is a diagram schematically depicting an example of the refrigeration cycle of an air-conditioner S3 according to a third embodiment of the present invention. As depicted in Fig. 4, the basic configuration of the refrigeration cycle of the air-conditioner S3 according to the third embodiment is nearly the same as the configuration of the refrigeration cycle of the air-conditioner S2 according to the second embodiment depicted in Fig. 3, and differs in the following respects.
That is, in the air-conditioner S2 according to the second embodiment, only one each of the connecting valves 81, 82 is disposed on the respective common refrigerant pipes ahead of where the refrigerant pipes respectively connected to the refrigerant switching part 20 and the outdoor heat exchanger 30 are branched into a plurality of refrigerant pipes. Meanwhile, in the air-conditioner S3 according to the third embodiment, eight connecting valves 81a to 88a are added, and the eight connecting valves 81a to 88a and the three refrigerant adjustment valves 41 to 43 are together housed in a branch box 100.
The connecting valves 81a, 82a disposed in the branch box 100 are connected via refrigerant pipes to the connecting valves 81, 82 disposed on the outdoor unit side. In the branch box 100, the refrigerant pipes connected to the connecting valves 81a, 82a are each branched into three branched refrigerant pipes, for example, and the connecting valves 83a to 88a are disposed at the distal end portions of the respectively branched three (a total of six) branched refrigerant pipes. Further, the refrigerant adjustment valves 41 to 43 are disposed on the respective branched refrigerant pipes connecting the connecting valve 81a and the connecting valves 83a, 85a, 87a.
The branch box 100 is disposed at the corner of an indoor bathroom, for example. The connecting valves 83a, 85a, 87a in the branch box 100 are respectively connected via indoor refrigerant pipes to the indoor heat exchangers 51, 52 and one refrigerant pipe-connecting part of the hot-water supply heat exchanger 61. The connecting valves 84a, 86a, 88a are respectively connected via refrigerant pipes passing through the refrigerant on-off valves 71 to 73 to the indoor heat exchangers 51, 52 and the other refrigerant pipe-connecting part of the hot-water supply heat exchanger 61.
As will be seen easily from Fig. 4, the sets of the connecting valves (83a, 84a), (85a, 86a), (87a, 88a) in the branch box 100 are entirely equivalent. Accordingly, the indoor heat exchangers 51, 52 and the hot-water supply heat exchanger 61 can be connected to the sets of the connecting valves (83a, 84a), (85a, 86a), (87a, 88a) in a desired combination.
The configuration of the refrigeration cycle of the air-conditioner S3 according to the third embodiment is basically the same as the configuration of the refrigeration cycle of the air-conditioner S1 according to the first embodiment. Accordingly, the air-conditioner S3 according to the third embodiment can be operated in the same operation modes as in the case of the first embodiment. That is, the air-conditioner S3 has the three operation modes for cooling operation, heating operation, and boiling-up operation. The cooling operation includes the boiling-up preferred cooling operation. The heating operation includes the boiling-up preferred heating operation, the normal defrosting operation, the comfortable defrosting operation, and the rapid defrosting operation. The boiling-up operation includes the comfortable defrosting operation.
In these operation modes, the open-close control performed by the controller 90 with respect to the switching main valve 21, the refrigerant on-off valves 71 to 73, and the refrigerant adjustment valves 41 to 43 is the same as illustrated in Fig. 2. Thus, the description herein of the control operation in each operation mode will be omitted.
Accordingly, with the air-conditioner S3 according to the third embodiment, it is also possible to obtain the same effects as those of the air-conditioner S1 of the first embodiment. In addition, the third embodiment is provided with the branch box 100, making it possible to use common branch-less refrigerant pipes for the refrigerant pipes connecting the connecting valves 81, 82 on the outdoor unit side and the connecting valves 81a, 82a in the branch box 100. Accordingly, the length of the refrigerant pipes as a whole can be reduced.
While some noise may be generated from the valves due to the opening and closing or the opening-degree control of the refrigerant adjustment valves 41 to 43, the branch box 100 containing the refrigerant adjustment valves 41 to 43 can be installed outdoors. Even when installed indoors, the branch box 100 can be installed in the bathroom or the like where noise is relatively not an issue. Thus, it is possible to prevent an indoor resident from being annoyed by the noise from the refrigerant adjustment valves 41 to 43.

<<Fourth embodiment>>

Fig. 5 is a diagram schematically depicting an example of the refrigeration cycle of an air-conditioner S4 according to a fourth embodiment of the present invention. As depicted in Fig. 5, the basic configuration of the refrigeration cycle of the air-conditioner S4 according to the fourth embodiment is nearly the same as the configuration of the refrigeration cycle of the air-conditioner S3 according to the third embodiment depicted in Fig. 4, and differs in the following respects.
That is, in the air-conditioner S3 according to the third embodiment, the refrigerant on-off valves 71, 72, 73 are disposed on the side of the indoor heat exchangers 51, 52 or the hot-water supply heat exchanger 61 outside the branch box 100. On the other hand, in the air-conditioner S4 according to the fourth embodiment, the refrigerant on-off valves 71, 72, 73 are disposed in the branch box 100.
Other than the above, the air-conditioner S4 according to the fourth embodiment is the same as the air-conditioner S3 according to the third embodiment. Accordingly, the description of the operation modes of the air-conditioner S4 and the control operation in the operation modes will be omitted.
Accordingly, it is possible to obtain from the air-conditioner S4 according to the fourth embodiment the same effects as those from the air-conditioner S3 according to the third embodiment. In addition, in the air-conditioner S4, the refrigerant on-off valves 71, 72, 73 are disposed in the branch box 100. Thus, when the hot-water supply heat exchanger 61 is newly added, for example, it is not necessary to determine whether to newly add the refrigerant on-off valves 71, 72 on the side of the existing indoor heat exchangers 51, 52. Accordingly, it is possible to reduce the working time at the site for additional installation, for example, of a hot-water supply system including the hot-water supply heat exchanger 61.

DESCRIPTION OF REFERENCE SIGNS

10: Compressor
20: Refrigerant switching valve (Refrigerant switching part)
21: Switching main valve
30: Outdoor heat exchanger
31: Outdoor air blower
31a: Outdoor air flow direction
41, 42: Refrigerant adjustment valve (first refrigerant adjustment valve)
43: Refrigerant adjustment valve (second refrigerant adjustment valve)
51, 52: Indoor heat exchanger
60: Hot-water supply tank (tank)
61: Hot-water supply heat exchanger
71, 72: Refrigerant on-off valve (First refrigerant on-off valve)
73: Refrigerant on-off valve (Second refrigerant on-off 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)
81a to 88a: Connecting valve
90: Controller
91: Discharge temperature detector
92: Outdoor-air temperature detector
93: Outdoor heat exchanger temperature detector
94: Tank temperature detector (Tank temperature detection part)
100: Branch box
a to d: Refrigerant switching valve port
S1 to S4: Air-conditioner

Claims

An air-conditioner comprising:
a compressor (10) configured to compress a refrigerant;

an outdoor heat exchanger (30) configured to exchange heat between the refrigerant and outdoor air;

an indoor heat exchanger (51, 52) configured to exchange heat between the refrigerant and indoor air;

a hot-water supply heat exchanger (61) configured to exchange heat between the refrigerant and tank water stored in a tank (60);

a refrigerant switching part (20) configured to switch a direction of flow of the refrigerant flowing through a refrigerant pipe connecting the compressor (10), the indoor heat exchanger (51, 52) and the hot-water supply heat exchanger (61);

a first connecting valve for refrigerant pipe connection disposed on a first refrigerant pipe connecting the refrigerant switching part (20) and the indoor heat exchanger (51, 52);

a second connecting valve for refrigerant pipe connection disposed on a second refrigerant pipe connecting the outdoor heat exchanger (30) and the indoor heat exchanger (51, 52);

a third connecting valve for refrigerant pipe connection disposed on a third refrigerant pipe connecting the refrigerant switching part (20) and the hot-water supply heat exchanger (61);

a fourth connecting valve for refrigerant pipe connection disposed on a fourth refrigerant pipe connecting the outdoor heat exchanger (30) and the hot-water supply heat exchanger (61);

a first refrigerant on-off valve (71, 72) configured to open and close a refrigerant flow path disposed on the first refrigerant pipe between the first connecting valve and the indoor heat exchanger (51, 52);

a second refrigerant on-off valve (73) configured to open and close a refrigerant flow path disposed on the third refrigerant pipe between the third connecting valve and the hot-water supply heat exchanger (61);

a first refrigerant adjustment valve (41, 42) disposed on the second refrigerant pipe and functioning as an expansion valve for refrigerant expansion; and

a second refrigerant adjustment valve (43) disposed on the fourth refrigerant pipe and functioning as an expansion valve for refrigerant expansion,

characterized by a controller (90) configured to control the compressor (10), the outdoor heat exchanger (30), the refrigerant switching part (20), the indoor heat exchanger (51, 52), the hot-water supply heat exchanger (61), the first refrigerant on-off valve (71, 72), the second refrigerant on-off valve (73), the first refrigerant adjustment valve (41, 42), and the second refrigerant adjustment valve (43),

wherein the controller (90) is configured, during cooling operation for cooling the inside of a room in which the indoor heat exchanger (51, 52) is installed, to operate the compressor (10) and the outdoor heat exchanger (30) and to control: setting, via the refrigerant switching part (20), the direction of flow of refrigerant so as to cause the refrigerant heated by the compressor (10) to be supplied to the indoor heat exchanger (51, 52); turning on the indoor heat exchanger (51, 52); turning off the hot-water supply heat exchanger (61); opening the first refrigerant on-off valve (71, 72) and the second refrigerant on-off valve (73); subjecting the first refrigerant adjustment valve (41, 42) to opening-degree control; and closing the second refrigerant adjustment valve (43).
The air-conditioner according to claim 1, wherein the controller (90) is configured, if a boiling-up operation of the hot-water supply heat exchanger (61) has been started during cooling operation, to control: turning off the indoor heat exchanger (51, 52); turning on the hot-water supply heat exchanger (61); switching the direction of the flow of refrigerant in the refrigerant switching part (20) to an opposite direction; closing the first refrigerant on-off valve (71, 72); opening the second refrigerant on-off valve (73); opening the first refrigerant adjustment valve (41, 42); and subjecting the second refrigerant adjustment valve (43) to opening-degree control.
The air-conditioner according to claim 2, further comprising a tank temperature detection part (94) configured to detect a temperature of tank water stored in the tank (60),
wherein the controller (90) is configured, if, even after a predetermined time or more has elapsed since the start of the boiling-up operation of the hot-water supply heat exchanger (61), a tank detection temperature detected by the tank temperature detection part (94) does not reach a predetermined target boiling-up temperature, to control:
stopping the boiling-up operation of the hot-water supply heat exchanger (61) to resume the cooling operation.
The air-conditioner according to claim 2, further comprising a heating means different from the hot-water supply heat exchanger (61) configured to heat tank water stored in the tank (60),
wherein the controller (90) is configured, if the boiling-up operation of the hot-water supply heat exchanger (61) has been configured to stop before the temperature of the tank water reaches a predetermined target boiling-up temperature, to control heating the tank water using the heating means until the temperature of the tank water reaches the target boiling-up temperature.