Hot water supply air-conditioning system, method of controlling hot water supply air-conditioning system, and control apparatus

Abstract

A hot water supply air-conditioning system is provided and includes an outdoor unit that includes a compressor configured to compress a first heat medium, and is configured to supply the first heat medium; a hot water supply unit configured to generate hot water using the first heat medium supplied from the outdoor unit; an indoor unit configured to perform air conditioning using the first heat medium supplied from the outdoor unit; a shutoff unit configured to shut off the first heat medium flowing into the indoor unit; and a controller configured to, in a case in which the first heat medium leaks in the indoor unit, perform control to shut off the first heat medium flowing into the indoor unit using the shutoff unit, and continue operation of the compressor to continue supply of the first heat medium from the outdoor unit to the hot water supply unit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation application of International Application No. PCT / JP2024 / 029596, filed on Aug. 21, 2024, and designated the U.S., which is based upon and claims priority to Japanese Patent Application No. 2023-170939, filed on Sep. 29, 2023, the entire contents of which are incorporated herein by reference.BACKGROUND1. Field of the Invention

[0002] The present disclosure relates to a hot water supply air-conditioning system, a method of controlling the hot water supply air-conditioning system, and a control apparatus.2. Description of the Related Art

[0003] Japanese Laid-Open Patent Application No. 2019-529857 discloses a hot water supply air-conditioning system including an outdoor unit, a plurality of indoor units each of which is connected to the outdoor unit, and a hot water supply unit connected to the outdoor unit to be arranged in parallel to the plurality of indoor units.

[0004] Japanese Laid-Open Patent Application No. 2012-013339 discloses an air conditioner in which an outdoor unit and a plurality of indoor units are connected by refrigerant piping. The air conditioner disclosed in Japanese Laid-Open Patent Application No. 2012-013339 includes an external attachment device including an expansion valve and an electromagnetic valve. The expansion valve is provided on one side of a plurality of refrigerant pipes connecting the indoor units and the outdoor unit, and the electromagnetic valve is provided on the other of the plurality of refrigerant pipes. The expansion valve and the electromagnetic valve are closed at the time of leakage of the refrigerant.SUMMARY

[0005] A hot water supply air-conditioning system of a first aspect includes: an outdoor unit that includes a compressor configured to compress a first heat medium, and is configured to supply the first heat medium;

[0006] a hot water supply unit configured to generate hot water using the first heat medium supplied from the outdoor unit;

[0007] an indoor unit configured to perform air conditioning using the first heat medium supplied from the outdoor unit;

[0008] a shutoff unit configured to shut off the first heat medium flowing into the indoor unit; and

[0009] a controller configured to, in a case in which the first heat medium leaks in the indoor unit, perform control to shut off the first heat medium flowing into the indoor unit using the shutoff unit, and continue operation of the compressor to continue supply of the first heat medium from the outdoor unit to the hot water supply unit.

[0010] According to the hot water supply air-conditioning system of the first aspect, the operation of the hot water supply unit can be continued when the refrigerant leaks in the indoor unit.

[0011] A hot water supply air-conditioning system of a second aspect is the hot water supply air-conditioning system of the first aspect in which the hot water supply unit includes a cascade heat medium circuit configured to generate hot water by a second heat medium having exchanged heat with the first heat medium.

[0012] A hot water supply air-conditioning system of a third aspect is the hot water supply air-conditioning system of the second aspect in which the cascade heat medium circuit is configured to continue circulation of the second heat medium in the case in which the first heat medium leaks in the indoor unit.

[0013] A hot water supply air-conditioning system of a fourth aspect is the hot water supply air-conditioning system of the second or third aspect in which the first heat medium is R32, and the second heat medium is 1234yf.

[0014] A hot water supply air-conditioning system of a fifth aspect is the hot water supply air-conditioning system of any one of the first to fourth aspects in which the indoor unit includes an expansion valve, and the expansion valve functions as a shutoff valve in the shutoff unit.

[0015] A hot water supply air-conditioning system of a sixth aspect is the hot water supply air-conditioning system of any one of the first to fifth aspects in which an amount m of the first heat medium released from the indoor unit after the shutoff unit is shut off satisfies an expression 1:m≤max⁡(m1,mm⁢ax)(Expression⁢ 1)m1=6×LFL(Expression⁢ 2)mm⁢ax=min⁡(2.5×(LFL)5 / 4×h0×(A)1 / 2,SF×LFL×h0×A)(Expression⁢ 3)where max(a, b) is a function that returns larger of a and b, min(a, b) is a function that returns smaller of a and b, LFL is a lower flammable limit of the heat medium (unit: kilogram per cubic meter (kg / m3)), A is a minimum room area (unit: square meter (m2)), h0 is a floor height (unit: meter (m)), SF is a constant (0.5), and the floor height h0 is determined according to an expression 4:h0=hinst+hrel(Expression⁢ 4)where hinst is a height of a product bottom surface from a floor, and hrel is a height of an opening from the product bottom surface with a cumulative opening area from the bottom surface reaching 5 square centimeters (excluding holes with a dimension of 0.1 millimeters or less).A hot water supply air-conditioning system of a seventh aspect is the hot water supply air-conditioning system of any one of the first to sixth aspects in which a plurality of the indoor units are provided, a plurality of the shutoff units are each provided for one of the plurality of the indoor units, and the controller is configured to perform control to shut off the first heat medium by the shutoff unit in the indoor unit in which the first heat medium leaks, and continue supply of the first heat medium to the indoor units other than the indoor unit in which the first heat medium leaks.A hot water supply air-conditioning system of an eighth aspect is the hot water supply air-conditioning system of any one of the first to seventh aspects in which the first heat medium is a slightly flammable refrigerant or a flammable refrigerant.A hot water supply air-conditioning system of a ninth aspect is the hot water supply air-conditioning system of any one of the first to eighth aspects in which the first heat medium is R32.

[0019] A hot water supply air-conditioning system of a tenth aspect is the hot water supply air-conditioning system of any one of the first to ninth aspects in which the hot water supply air-conditioning system is configured to stop the operation of the compressor in a case in which a capacity of the indoor unit with the shutoff unit closed is equal to or greater than a predetermined capacity with respect to a capacity of the outdoor unit.

[0020] A method of controlling a hot water supply air-conditioning system of a first aspect is a method of controlling a hot water supply air-conditioning system including an outdoor unit that includes a compressor configured to compress a first heat medium, and is configured to supply the first heat medium, a hot water supply unit configured to generate hot water using the first heat medium supplied from the outdoor unit, an indoor unit configured to perform air conditioning using the first heat medium supplied from the outdoor unit, and a shutoff unit configured to shut off the first heat medium flowing into the indoor unit. The method includes, in a case in which the first heat medium leaks in the indoor unit, shutting off the first heat medium flowing into the indoor unit using the shutoff unit, and continuing operation of the compressor to continue supply of the first heat medium from the outdoor unit to the hot water supply unit.

[0021] According to the method of controlling the hot water supply air-conditioning system of the first aspect, it is possible to continue the hot water supply function when the refrigerant leaks in the indoor unit.

[0022] A control apparatus of a first aspect is a control apparatus for use in a hot water supply air-conditioning system including an outdoor unit that includes a compressor configured to compress a first heat medium, and is configured to supply the first heat medium, a hot water supply unit configured to generate hot water using the first heat medium supplied from the outdoor unit, an indoor unit configured to perform air conditioning using the first heat medium supplied from the outdoor unit, and a shutoff unit configured to shut off the first heat medium flowing into the indoor unit. The control apparatus is configured to, in a case in which the first heat medium leaks in the indoor unit, perform control to shut off the first heat medium flowing into the indoor unit using the shutoff unit, and continue operation of the compressor to continue supply of the first heat medium from the outdoor unit to the hot water supply unit.

[0023] According to the control apparatus of the first aspect, it is possible to continue the hot water supply function when the refrigerant leaks in the indoor unit.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a diagram illustrating an outline of a configuration of a hot water supply air-conditioning system according to a first embodiment of the present disclosure.

[0025] FIG. 2 is a diagram illustrating an outline of an outdoor unit included in the hot water supply air-conditioning system according to the first embodiment.

[0026] FIG. 3 is a diagram illustrating an outline of a hot water supply unit included in the hot water supply air-conditioning system according to the first embodiment.

[0027] FIG. 4 is a diagram illustrating an outline of an indoor unit and a shutoff unit included in the hot water supply air-conditioning system according to the first embodiment.

[0028] FIG. 5 is a diagram illustrating a hardware configuration of a control unit included in the hot water supply air-conditioning system according to the first embodiment.

[0029] FIG. 6 is a diagram illustrating an outline of a cooling / heating switching unit included in the hot water supply air-conditioning system according to the first embodiment.

[0030] FIG. 7 is a flow diagram illustrating a process of the hot water supply air-conditioning system according to the first embodiment.

[0031] FIG. 8 is a diagram illustrating an outline of a configuration of a hot water supply air-conditioning system according to a second embodiment of the present disclosure.DETAILED DESCRIPTION OF THE DISCLOSURE

[0032] In a hot water supply air-conditioning system configured to perform both air conditioning and hot water supply, there is a need to continue a hot water supply function even when a refrigerant leaks in an indoor unit.

[0033] The present disclosure provides a technique of continuing operation of a hot water supply unit when a refrigerant leaks in an indoor unit.

[0034] Hereinafter, embodiments will be described with reference to the attached drawings. With respect to the description and drawings for the embodiments, the same reference signs may be assigned to components having substantially the same or corresponding functional configurations, thereby omitting duplicate descriptions. Also, for facilitating understanding, the scale of each component in the drawings may be different from the actual scale.First Embodiment

[0035] A hot water supply air-conditioning system according to a first embodiment will be described. The hot water supply air-conditioning system according to the first embodiment includes an outdoor unit, a hot water supply unit, an indoor unit, a shutoff unit, and a controller. The outdoor unit in the hot water supply air-conditioning system according to the first embodiment includes a compressor configured to compress a first heat medium, and is configured to supply the first heat medium. The hot water supply unit in the hot water supply air-conditioning system according to the first embodiment is configured to generate hot water using the first heat medium supplied from the outdoor unit. The indoor unit in the hot water supply air-conditioning system according to the first embodiment is configured to perform air conditioning using the first heat medium supplied from the outdoor unit. The shutoff unit in the hot water supply air-conditioning system according to the first embodiment is configured to shut off the first heat medium flowing into the indoor unit. The controller in the hot water supply air-conditioning system according to the first embodiment is configured to, in a case in which the first heat medium leaks in the indoor unit, perform control to shut off the first heat medium flowing into the indoor unit using the shutoff unit. Also, the controller in the hot water supply air-conditioning system according to the first embodiment is configured to perform control to continue operation of the compressor to continue supply of the first heat medium from the outdoor unit to the hot water supply unit.

[0036] FIG. 1 is a diagram illustrating an outline of a configuration of a hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment.[Hot Water Supply Air-Conditioning System 1]

[0037] The hot water supply air-conditioning system 1 is configured to generate hot water (supply hot water) and perform air conditioning of a predetermined space. The hot water supply air-conditioning system 1 is what is referred to as a heat pump type hot water supply air-conditioning system. For example, the hot water supply air-conditioning system 1 can supply hot water while performing a heating or cooling operation.

[0038] The hot water supply air-conditioning system 1 includes an outdoor unit 10, a hot water supply unit 20, an indoor unit 30, a shutoff unit 40, and a control unit 50. Also, the hot water supply air-conditioning system 1 includes a cooling / heating switching unit 60a between the outdoor unit 10 and the hot water supply unit 20. Further, the hot water supply air-conditioning system 1 includes a cooling / heating switching unit 60b between the outdoor unit 10 and the indoor unit 30. Each component of the hot water supply air-conditioning system 1 will be described in detail.(Outdoor Unit 10)

[0039] The outdoor unit 10 will be described in detail. FIG. 2 is a diagram illustrating an outline of the outdoor unit 10 included in the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment.

[0040] The outdoor unit 10 is configured to supply a first heat medium RF1 to each of the hot water supply unit 20 and the indoor unit 30. The outdoor unit 10 is provided outdoors, such as on a rooftop, a balcony, or the like of a building. Alternatively, the outdoor unit 10 is, for example, provided underground. The outdoor unit 10, for example, uses a fluorocarbon alternative, R32, as the first heat medium RF1. The outdoor unit 10 may, for example, use propane as the first heat medium RF1. Also, R454B may be used as the first heat medium RF1.

[0041] R32 is a refrigerant that is slightly flammable (slightly flammable refrigerant). Propane is a refrigerant that is flammable (flammable refrigerant).

[0042] The outdoor unit 10 includes a compressor 11, an accumulator 12, heat exchangers 13a and 13b, expansion valves 14a and 14b, four-way switching valves 15a, 15b, and 15c, and a fan 16.

[0043] The compressor 11 is configured to compress the first heat medium RF1. The compressor 11 is, for example, a scroll type or rotary type positive displacement compressor having a sealed structure including a built-in motor for the compressor. The compressor 11 compresses the drawn-in low-pressure first heat medium RF1. Then, the compressor 11 discharges the compressed first heat medium RF1.

[0044] The accumulator 12 is configured to temporarily store the low-pressure first heat medium RF1 drawn in the compressor 11. The accumulator 12 temporarily stores the first heat medium RF1, thereby separating the first heat medium RF1 into gas and liquid.

[0045] Each of the heat exchangers 13a and 13b is configured to perform heat exchange between the first heat medium RF1 and outside air. Each of the heat exchangers 13a and 13b is, for example, a cross-fin type or microchannel type heat exchanger.

[0046] Each of the expansion valves 14a and 14b is configured to depressurize the first heat medium RF1 passing therethrough. Each of the expansion valves 14a and 14b is, for example, an electric valve whose opening degree is adjustable.

[0047] Each of the four-way switching valves 15a, 15b, and 15c is configured to switch a flow of the first heat medium RF1. Each of the four-way switching valves 15a, 15b, and 15c functions as a substantially three-way valve because one of the flow paths is closed.

[0048] The fan 16 is configured to generate a flow of air flowing through the heat exchangers 13a and 13b. The fan 16 is, for example, an axial flow fan.

[0049] A liquid communication pipe RL1, a drawn-in gas communication pipe RL2, and a high / low pressure gas communication pipe RL3 are connected to the outdoor unit 10.

[0050] The hot water supply air-conditioning system 1 generates hot water in the hot water supply unit 20, and performs heating and cooling operations in the indoor unit 30. The operation of the outdoor unit 10 when performing the heating and cooling operations in the indoor unit 30 will be described.(1) Heating Operation

[0051] When the indoor unit 30 performs the heating operation, the first heat medium RF1 compressed in the compressor 11 is discharged from the high / low pressure gas communication pipe RL3 through the four-way switching valve 15c.

[0052] The first heat medium RF1 returned from the liquid communication pipe RL1 is branched to flow into each of the expansion valves 14a and 14b. The first heat medium RF1 branched to the expansion valve 14a is depressurized when passing through the expansion valve 14a. Then, the first heat medium RF1 depressurized in the expansion valve 14a performs heat exchange with outdoor air to evaporate when passing through the heat exchanger 13a. Then, the first heat medium RF1 evaporated in the heat exchanger 13a is drawn in the compressor 11 through the four-way switching valve 15a and the accumulator 12. Similarly, the first heat medium RF1 branched to the expansion valve 14b is depressurized when passing through the expansion valve 14b. Then, the first heat medium RF1 depressurized in the expansion valve 14b performs heat exchange with outdoor air to evaporate when passing through the heat exchanger 13b. Then, the first heat medium RF1 evaporated in the heat exchanger 13a is drawn in the compressor 11 through the four-way switching valve 15b and the accumulator 12.(2) Cooling Operation (Cooling+Hot Water Supply)

[0053] When the indoor unit 30 performs the cooling operation, the first heat medium RF1 compressed in the compressor 11 is branched to flow into each of the four-way switching valves 15a and 15c. The first heat medium RF1 branched to the four-way switching valve 15a performs heat exchange with outdoor air to condense in the heat exchanger 13a. The first heat medium RF1 condensed in the heat exchanger 13a is discharged from the liquid communication pipe RL1 through the expansion valve 14a. The first heat medium RF1 branched to the four-way switching valve 15c is discharged from the high / low pressure gas communication pipe RL3.

[0054] The first heat medium RF1 returned from the drawn-in gas communication pipe RL2 is drawn in the compressor 11 through the accumulator 12.(Hot Water Supply Unit 20)

[0055] The hot water supply unit 20 is configured to generate hot water using the first heat medium RF1 supplied from the outdoor unit 10.

[0056] FIG. 3 is a diagram illustrating an outline of the hot water supply unit 20 included in the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment.

[0057] The hot water supply unit 20 includes a cascade heat medium circuit 20s configured to generate hot water by a second heat medium RF2 having exchanged heat with the first heat medium RF1.

[0058] The hot water supply unit 20 is, for example, integrated with the outdoor unit 10. The hot water supply unit 20 integrated with the outdoor unit 10 is provided outdoors, such as on a rooftop, a balcony, or the like of a building. Alternatively, the hot water supply unit 20 is, for example, provided underground. The hot water supply unit 20, for example, uses a fluorocarbon alternative, 1234yf, as the second heat medium RF2. 1234yf is a refrigerant that is slightly flammable (slightly flammable refrigerant). 1234ze may be used as the second heat medium RF2. The combination of the first heat medium RF1 and the second heat medium RF2 is not limited to the combination of R32 and 1234yf, and may be, for example, a combination of R454B and 1234yf, a combination of RF454B and 1234ze, or a combination of R32 and 1234ze.

[0059] The hot water supply unit 20 includes a compressor 21, an accumulator 22, heat exchangers 23 and 24, expansion valves 25 and 26, a pump 27, a four-way switching valve 28, and check valves 29a and 29b.

[0060] The compressor 21 is configured to compress the second heat medium RF2. The compressor 21 is, for example, a scroll type or rotary type positive displacement compressor having a sealed structure including a built-in motor for the compressor. The compressor 21 compresses the drawn-in low-pressure second heat medium RF2. Then, the compressor 21 discharges the compressed second heat medium RF2.

[0061] The accumulator 22 is configured to temporarily store the low-pressure second heat medium RF2 drawn in the compressor 21. The accumulator 22 temporarily stores the second heat medium RF2, thereby separating the second heat medium RF2 into gas and liquid.

[0062] The heat exchanger 23 is configured to perform heat exchange between the first heat medium RF1 and the second heat medium RF2. The heat exchanger 23 is, for example, a plate type or spiral type heat exchanger.

[0063] The heat exchanger 24 is configured to perform heat exchange between the second heat medium RF2 and water. The heat exchanger 24 is, for example, a double-tube heat exchanger.

[0064] The expansion valve 25 is configured to depressurize the first heat medium RF1 passing therethrough. The expansion valve 26 is configured to depressurize the second heat medium RF2 passing therethrough. Each of the expansion valves 25 and 26 is, for example, an electric valve whose opening degree is adjustable.

[0065] The pump 27 is configured to send water to the heat exchanger 24.

[0066] The four-way switching valve 28 is configured to switch a flow of the second heat medium RF2.

[0067] The check valve 29a is configured to prevent backflow of the second heat medium RF2 into the compressor 21. The check valve 29b is configured to prevent backflow of water.(Indoor Unit 30)

[0068] The indoor unit 30 is configured to perform air conditioning of a predetermined space RM.

[0069] FIG. 4 is a diagram illustrating an outline of the indoor unit 30 and the shutoff unit 40 included in the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment.

[0070] The indoor unit 30 includes a heat exchanger 31, an expansion valve 32, a detector 33, and a fan 34.

[0071] The heat exchanger 31 is configured to perform heat exchange between the first heat medium RF1 and air. The heat exchanger 31 is, for example, a cross-fin type or microchannel type heat exchanger.

[0072] The expansion valve 32 is configured to depressurize the first heat medium RF1 passing therethrough. The expansion valve 32 is, for example, an electric valve whose opening degree is adjustable.

[0073] The detector 33 is configured to detect the first heat medium RF1. The detector 33 detects the first heat medium RF1, thereby detecting the leakage of the first heat medium RF1.

[0074] The fan 34 is configured to generate an air flow passing through the heat exchanger 31. The fan 34 is, for example, a sirocco fan.(Shutoff Unit 40)

[0075] The shutoff unit 40 is configured to shut off the first heat medium RF1 flowing from the outdoor unit 10 to the indoor unit 30.

[0076] The shutoff unit 40 includes shutoff valves 41 and 42. Each of the shutoff valves 41 and 42 is, for example, an electric valve.

[0077] The shutoff unit 40 is configured to close the shutoff valves 41 and 42, for example, when the detector 33 included in the indoor unit 30 detects leakage of the first heat medium RF1. Then, the shutoff unit 40 shuts off supply of the first heat medium RF1 to the indoor unit 30.

[0078] The amount of the first heat medium RF1 released from the indoor unit 30 after the shutoff unit 40 is shut off will be described. In other words, the amount of the first heat medium RF1 remaining from the shutoff unit 40 to the indoor unit 30 after the shutoff unit 40 is shut off will be described.

[0079] An amount m of the first heat medium RF1 released from the indoor unit 30 after the shutoff unit 40 is shut off desirably satisfies an expression A.m≤max⁡(m1,mm⁢ax)(Expression⁢ A)m1=6×LFL(Expression⁢ B)mm⁢ax=min⁡(2.5×(LFL)5 / 4×h0×(A)1 / 2,SF×LFL×h0×A)(Expression⁢ C)

[0080] Here, max(a, b) is a function that returns the larger of a and b, and min(a, b) is a function that returns the smaller of a and b. LFL is a lower flammable limit of the first heat medium RF1 (unit: kilogram per cubic meter (kg / m3)). When the first heat medium RF1 is R32, LFL is, for example, 0.307 kilogram per cubic meter (kg / m3). A is the minimum room area (unit: square meter (m2), h0 is a floor height (unit: meter (m)), and SF is a constant (0.5). The floor height h0 is determined according to an expression D.h0=hinst+hrel(Expression⁢ D)

[0081] Here, hinst is a height of a product bottom surface from a floor, and hrel is a height of an opening from the product bottom surface with a cumulative opening area from the bottom surface reaching 5 square centimeters (excluding holes with a dimension of 0.1 millimeters or less).(Control Unit 50)

[0082] The control unit 50 is configured to control the outdoor unit 10, the hot water supply unit 20, the indoor unit 30, and the cooling / heating switching units 60a and 60b. FIG. 5 is a hardware configuration diagram illustrating a hardware configuration of the control unit 50 included in the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment.

[0083] The control unit 50 includes a controller 51, a RAM (Random Access Memory) 52, and a ROM (Read Only Memory) 53. Also, the control unit 50 includes a storage I / F (Interface) 54 and an external I / F 55. The controller 51, the RAM 52, the ROM 53, the storage I / F 54, and the external I / F 55 are connected to a bus B1.

[0084] For example, a storage medium 54a is connected to the storage I / F 54. For example, the outdoor unit 10, the hot water supply unit 20, the indoor unit 30, and the cooling / heating switching units 60a and 60b are connected to the external I / F 55.

[0085] The controller 51 is a processor, such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or the like. The controller 51 may be an ASIC (application specific integrated circuit) or an FPGA (Field-Programmable Gate Array). When the controller 51 executes a program, the processes described in the present specification are performed. The controller 51 is an arithmetic unit configured to read out a program (app., application) from a storage device, such as the ROM 53, the storage medium 54a, or the like, on the RAM 52, thereby executing the processes. The controller 51, the RAM 52, and the ROM 53 form a computer configured to control the hot water supply air-conditioning system 1.

[0086] The RAM 52 is, for example, a volatile semiconductor memory configured to temporarily store a program (app., application) or the like.

[0087] The ROM 53 is, for example, a nonvolatile semiconductor memory configured to store a program (app., application) or the like even if the power is turned off. The ROM 53 stores a program, such as a BIOS (Basic Input / Output System) to be executed at startup, and various settings, such as an OS (Operating System) setting, a network setting, and the like.

[0088] The storage I / F 54 is an interface with an external storage device, such as the storage medium 54a or the like.

[0089] The storage medium 54a is, for example, an SD (Secure Digital) memory card, a USB (Universal Serial Bus) memory, an HDD (Hard Disk Drive), or an SSD (Solid State Drive).

[0090] The external I / F 55 is an interface configured to connect peripheral equipment and the controller 51. Via the external I / F 55, the controller 51 is connected to each of the outdoor unit 10, the hot water supply unit 20, the indoor unit 30, and the cooling / heating switching units 60a and 60b. (Cooling / Heating Switching Units 60a and 60b)

[0091] Each of the cooling / heating switching units 60a and 60b is configured to control a flow path through which the first heat medium RF1 flows, for example, such that cooling, heating, and hot water supply can be performed simultaneously.

[0092] FIG. 6 is a diagram illustrating an outline of the cooling / heating switching unit 60 included in the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment. Since the cooling / heating switching units 60a and 60b have the same configuration, the cooling / heating switching units 60a and 60b will be described using the cooling / heating switching unit 60.

[0093] The cooling / heating switching unit 60 includes a heat exchanger 61, and control valves 62, 63, and 64.

[0094] The operation of the cooling / heating switching unit 60 when performing each of the heating operation and the cooling operation in the indoor unit 30 will be described.(1) Heating Operation

[0095] When the indoor unit 30 performs the heating operation, in the cooling / heating switching unit 60 connected to each of the hot water supply unit 20 and the indoor unit 30, the control valve 63 connected to the high / low pressure gas communication pipe RL3 is opened. Then, each of the control valves 62 and 64 is closed. By opening the control valve 63 and closing each of the control valves 62 and 64, the first heat medium RF1 flowing in from the high / low pressure gas communication pipe RL3 flows out to the pipe PL2, and the first heat medium RF1 flowing in from the pipe PL1 flows out to the liquid communication pipe RL1.(2) Cooling Operation (Cooling+Hot Water Supply)

[0096] When the indoor unit 30 performs the cooling operation, in the cooling / heating switching unit 60 connected to the hot water supply unit 20, the control valve 63 connected to the high / low pressure gas communication pipe RL3 is opened, and each of the control valves 62 and 64 is closed. By opening the control valve 63 and closing each of the control valves 62 and 64, the first heat medium RF1 flowing in from the high / low pressure gas communication pipe RL3 flows out to the pipe PL2, and the first heat medium RF1 flowing in from the pipe PL1 flows out to the liquid communication pipe RL1.

[0097] In the cooling / heating switching unit 60 connected to the indoor unit 30, the control valve 64 connected to the drawn-in gas communication pipe RL2 is opened. Then, each of the control valves 62 and 63 is closed. By opening the control valve 64 and closing each of the control valves 62 and 63, the first heat medium RF1 flowing in from the liquid communication pipe RL1 flows out to the pipe PL1, and the first heat medium RF1 flowing in from the pipe PL2 flows out to the drawn-in gas communication pipe RL2.<Process in the Hot Water Supply Air-Conditioning System According to the First Embodiment>

[0098] A process in the hot water supply air-conditioning system according to the first embodiment will be described. The process will be described using the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment. More specifically, the process in the controller 51 of the control unit 50 included in the hot water supply air-conditioning system 1 will be described. A method of controlling the hot water supply air-conditioning system according to the present embodiment will be described by describing the process in the controller 51 of the control unit 50 included in the hot water supply air-conditioning system 1.

[0099] FIG. 7 is a flow diagram illustrating a process of the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment.(Step S10)

[0100] First, the controller 51 detects whether or not there is leakage of the first heat medium RF1 in the indoor unit 30 (heat medium leakage detection step). Specifically, the controller 51 obtains information of whether or not the detector 33 in the indoor unit 30 has detected the first heat medium RF1.(Step S20)

[0101] Next, the controller 51 determines whether or not the first heat medium RF1 leaks in the indoor unit 30 based on a detection result in step S10. Specifically, when the detector 33 in the indoor unit 30 detects the first heat medium RF1, the controller 51 determines that the first heat medium RF1 leaks in the indoor unit 30. Conversely, when the detector 33 in the indoor unit 30 does not detect the first heat medium RF1, the controller 51 determines that the first heat medium RF1 does not leak in the indoor unit 30.

[0102] When determining in step S20 that the first heat medium RF1 leaks in the indoor unit 30 (YES in step S20), the controller 51 causes the process to proceed to step S30. When determining in step S20 that the first heat medium RF1 does not leak in the indoor unit 30 (NO in step S20), the controller 51 returns to step S10 and repeatedly performs the process.(Step S30)

[0103] When determining that the first heat medium RF1 leaks in the indoor unit 30 (YES in step S20), the controller 51 shuts off the flow of the first heat medium RF1 to the indoor unit 30 using the shutoff unit 40 (shutoff step). Specifically, the controller 51 stops the supply of the first heat medium RF1 to the indoor unit 30 by closing each of the shutoff valves 41 and 42 included in the shutoff unit 40.

[0104] At the time of step S30, the operation of the compressor 11 in the outdoor unit 10 is continued. Then, the outdoor unit 10 continues the supply of the first heat medium RF1 to the hot water supply unit 20. Further, the circulation of the second heat medium RF2 in the hot water supply unit 20 is continued. Since the supply of the first heat medium RF1 to the hot water supply unit 20 is continued, hot water can be continuously supplied in the hot water supply air-conditioning system 1.

[0105] In the above example, the controller 51 closes each of the shutoff valves 41 and 42 included in the shutoff unit 40. However, the controller 51 may close the expansion valve 32 included in the indoor unit 30. When closing the expansion valve 32, provision of the shutoff valve 42 in the shutoff unit 40 is optional.(Step S40)

[0106] Next, the controller 51 determines whether or not the capacity of the indoor unit 30 in which the supply of the first heat medium RF1 has been stopped is equal to or greater than a predetermined capacity (capacity determination step). Specifically, the controller 51 obtains the capacity of the indoor unit 30 in which the first heat medium RF1 has been shut off by the shutoff unit 40. Then, the controller 51 determines whether or not the capacity of the indoor unit 30 in which the first heat medium RF1 has been shut off by the shutoff unit 40 is equal to or greater than a predetermined capacity.

[0107] The predetermined capacity may be appropriately determined to protect the compressor 11 in the outdoor unit 10. The predetermined capacity is, for example, 50% of the capacity of the outdoor unit 10. The predetermined capacity may be, for example, 20%, 25%, 30%, or 40% of the capacity of the outdoor unit 10.

[0108] When determining in step S40 that the capacity of the indoor unit 30 in which the supply of the first heat medium RF1 has been stopped is equal to or greater than the predetermined capacity (YES in step S40), the controller 51 causes the process to proceed to step S50. When determining in step S40 that the capacity of the indoor unit 30 in which the supply of the first heat medium RF1 has been stopped is less than the predetermined capacity (NO in step S40), the controller 51 ends the process.(Step S50)

[0109] When determining in step S40 that the capacity of the indoor unit 30 in which the supply of the first heat medium RF1 has been stopped is equal to or greater than the predetermined capacity (YES in step S40), the controller 51 stops the operation of the compressor 11 in the outdoor unit 10 (compressor stop step). The controller 51 ends the process after stopping the operation of the compressor 11.

[0110] According to the hot water supply air-conditioning system according to the first embodiment, when the refrigerant leaks in the indoor unit, the hot water supply function can be continued. In the hot water supply air-conditioning system according to the first embodiment, when the first heat medium leaks in the indoor unit, the first heat medium flowing into the indoor unit is shut off by the shutoff unit. Also, in the hot water supply air-conditioning system according to the first embodiment, when the first heat medium leaks in the indoor unit, the operation of the compressor is continued, and the supply of the first heat medium from the outdoor unit to the hot water supply unit is continued. Therefore, according to the hot water supply air-conditioning system according to the first embodiment, even if the refrigerant leaks in the indoor unit, the hot water supply function can be continued.

[0111] Although the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment, has been described based on the example in which the number of the indoor units 30 is one, the hot water supply air-conditioning system according to the first embodiment may include a plurality of indoor units. All the indoor units included in the hot water supply air-conditioning system according to the first embodiment may include the shutoff unit. Alternatively, at least one of the indoor units may include the shutoff unit.

[0112] When the plurality of indoor units are included, all the indoor units may be set to perform heating operation or cooling operation. Alternatively, some of the plurality of indoor units may be set to perform heating operation, and others of the plurality of indoor units may be set to perform cooling operation.

[0113] Although the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment, has been described based on the example in which the control is performed by the controller 51, the function of the controller in the hot water supply air-conditioning system according to the first embodiment is not limited to the case of being realized by the controller 51. The function of the controller in the hot water supply air-conditioning system according to the first embodiment may be realized by a controller included in the outdoor unit, a controller included in the hot water supply unit, or a controller included in the shutoff unit. Alternatively, the function of the controller may be realized by these controllers that work in cooperation. Similarly, for example, the function of the controller may be realized by a controller included in the cooling / heating switching unit 60 in the hot water supply air-conditioning system 1, which is an example of the hot water supply air-conditioning system according to the first embodiment.

[0114] Further, the controller in the hot water supply air-conditioning system according to the first embodiment may be separately provided as the control apparatus for use in the hot water supply air-conditioning system. In other words, the control apparatus may be a control apparatus for use in a hot water supply air-conditioning system that includes the outdoor unit, the hot water supply unit, the indoor unit, and the shutoff unit in the hot water supply air-conditioning system according to the first embodiment. Then, the control apparatus may perform control to shut off the first heat medium flowing into the indoor unit using the shutoff unit when the first heat medium leaks in the indoor unit. Also, the control apparatus may perform control to continue the operation of the compressor to continue the supply of the first heat medium from the outdoor unit to the hot water supply unit when the first heat medium leaks in the indoor unit.Second Embodiment

[0115] A hot water supply air-conditioning system according to a second embodiment includes a plurality of indoor units. Also, the hot water supply air-conditioning system according to the second embodiment includes a shutoff unit for each of the plurality of indoor units. In other words, the hot water supply air-conditioning system according to the second embodiment includes a plurality of shutoff units each provided for one of the indoor units. A controller in the hot water supply air-conditioning system according to the second embodiment is configured to perform control to shut off the first heat medium using the shutoff unit in the indoor unit in which the first heat medium leaks, and continue supply of the first heat medium to the indoor units other than the indoor unit in which the first heat medium leaks.

[0116] FIG. 8 is a diagram illustrating an outline of a configuration of a hot water supply air-conditioning system 2, which is an example of the hot water supply air-conditioning system according to the second embodiment.

[0117] The hot water supply air-conditioning system 2 includes indoor units 30A and 30B. In other words, the hot water supply air-conditioning system 2 includes two indoor units. The hot water supply air-conditioning system 2 includes a shutoff unit 40A configured to shut off a flow of the first heat medium RF1 into the indoor unit 30A when the first heat medium RF1 leaks in the indoor unit 30A. Also, the hot water supply air-conditioning system 2 includes a shutoff unit 40B configured to shut off a flow of the first heat medium RF1 into the indoor unit 30B when the first heat medium RF1 leaks in the indoor unit 30B.

[0118] The hot water supply air-conditioning system 2 includes a control unit 150 instead of the control unit 50 in the hot water supply air-conditioning system 1. The control unit 150 has the function of the control unit 50, and controls each of the shutoff units 40A and 40B.

[0119] In the hot water supply air-conditioning system 2, there is a case in which the first heat medium RF1 leaks in one of the indoor unit 30A or 30B, and the first heat medium RF1 does not leak in the other. A controller in the control unit 150 performs control to shut off the shutoff unit 40A or 40B connected to one of the indoor unit 30A or 30B with leakage. The controller in the control unit 150 performs control not to shut off the shutoff unit 40A or 40B connected to the other of the indoor unit 30A or 30B with leakage.

[0120] The controller in the control unit 150 shuts off only the shutoff unit connected to the indoor unit with leakage, thereby continuing the operation of the indoor unit without leakage.

[0121] Although the hot water supply air-conditioning system 2 has been described based on the example in which the number of the indoor units is two, the hot water supply air-conditioning system 2 according to the second embodiment may include three or more indoor units and shutoff units that are the same in number as the indoor units.

[0122] According to the hot water supply air-conditioning system according to the second embodiment, when the refrigerant leaks in the indoor unit, the hot water supply function can be continued. Also, according to the hot water supply air-conditioning system according to the second embodiment, when the refrigerant leaks in the indoor unit, the operation of the indoor unit in which the refrigerant does not leak can be continued.

[0123] When a plurality of indoor units are provided, all the plurality of indoor units may be set to perform heating operation or cooling operation. Alternatively, some of the plurality of indoor units may be set to perform heating operation, and others of the plurality of the indoor units may be set to perform cooling operation.

[0124] Although the embodiments have been described above, it should be understood that various changes in forms and details are possible without departing from the intent and scope of the claims. Various modifications and improvements are possible, such as combinations, substitutions, and the like with a part of or the entirety of any other embodiment.

Claims

1. A hot water supply air-conditioning system, comprising:an outdoor unit that includes a compressor configured to compress a first heat medium, and is configured to supply the first heat medium;a hot water supply unit configured to generate hot water using the first heat medium supplied from the outdoor unit;an indoor unit configured to perform air conditioning using the first heat medium supplied from the outdoor unit;a shutoff unit configured to shut off the first heat medium flowing into the indoor unit; anda controller configured to, in a case in which the first heat medium leaks in the indoor unit, perform control to shut off the first heat medium flowing into the indoor unit using the shutoff unit, and continue operation of the compressor to continue supply of the first heat medium from the outdoor unit to the hot water supply unit.

2. The hot water supply air-conditioning system according to claim 1, whereinthe hot water supply unit includes a cascade heat medium circuit configured to generate hot water by a second heat medium having exchanged heat with the first heat medium.

3. The hot water supply air-conditioning system according to claim 2, whereinthe cascade heat medium circuit is configured to continue circulation of the second heat medium in the case in which the first heat medium leaks in the indoor unit.

4. The hot water supply air-conditioning system according to claim 2, whereinthe first heat medium is R32, andthe second heat medium is 1234yf.

5. The hot water supply air-conditioning system according to claim 1, whereinthe indoor unit includes an expansion valve, andthe expansion valve functions as a shutoff valve in the shutoff unit.

6. The hot water supply air-conditioning system according to claim 1, whereinan amount m of the first heat medium released from the indoor unit after the shutoff unit is shut off satisfies an expression 1:m≤max⁡(m1,mm⁢ax)(Expression⁢ 1)m1=6×LFL(Expression⁢ 2)mm⁢ax=min⁡(2.5×(LFL)5 / 4×h0×(A)1 / 2,SF×LFL×h0×A)(Expression⁢ 3)where max(a, b) is a function that returns larger of a and b, min(a, b) is a function that returns smaller of a and b, LFL is a lower flammable limit of the first heat medium (unit: kilogram per cubic meter (kg / m3)), A is a minimum room area (unit: square meter (m2)), h0 is a floor height (unit: meter (m)), SF is a constant (0.5), and the floor height h0 is determined according to an expression 4:h0=hinst+hrel(Expression⁢ 4)where hinst is a height of a product bottom surface from a floor, and hrel is a height of an opening from the product bottom surface with a cumulative opening area from the bottom surface reaching 5 square centimeters (excluding holes with a dimension of 0.1 millimeters or less).

7. The hot water supply air-conditioning system according to claim 1, whereina plurality of the indoor units are provided,a plurality of the shutoff units are each provided for one of the plurality of the indoor units, andthe controller is configured to perform control to shut off the first heat medium by the shutoff unit in the indoor unit in which the first heat medium leaks, and continue supply of the first heat medium to the indoor units other than the indoor unit in which the first heat medium leaks.

8. The hot water supply air-conditioning system according to claim 1, whereinthe first heat medium is a slightly flammable refrigerant or a flammable refrigerant.

9. The hot water supply air-conditioning system according to claim 1, whereinthe first heat medium is R32.

10. The hot water supply air-conditioning system according to claim 1, whereinthe hot water supply air-conditioning system is configured to stop the operation of the compressor in a case in which a capacity of the indoor unit with the shutoff unit closed is equal to or greater than a predetermined capacity with respect to a capacity of the outdoor unit.

11. A method of controlling a hot water supply air-conditioning system including an outdoor unit that includes a compressor configured to compress a first heat medium, and is configured to supply the first heat medium, a hot water supply unit configured to generate hot water using the first heat medium supplied from the outdoor unit, an indoor unit configured to perform air conditioning using the first heat medium supplied from the outdoor unit, and a shutoff unit configured to shut off the first heat medium flowing into the indoor unit, the method comprising:in a case in which the first heat medium leaks in the indoor unit, shutting off the first heat medium flowing into the indoor unit using the shutoff unit, and continuing operation of the compressor to continue supply of the first heat medium from the outdoor unit to the hot water supply unit.

12. A control apparatus for use in a hot water supply air-conditioning system including an outdoor unit that includes a compressor configured to compress a first heat medium, and is configured to supply the first heat medium, a hot water supply unit configured to generate hot water using the first heat medium supplied from the outdoor unit, an indoor unit configured to perform air conditioning using the first heat medium supplied from the outdoor unit, and a shutoff unit configured to shut off the first heat medium flowing into the indoor unit, whereinthe control apparatus is configured to, in a case in which the first heat medium leaks in the indoor unit, perform control to shut off the first heat medium flowing into the indoor unit using the shutoff unit, and continue operation of the compressor to continue supply of the first heat medium from the outdoor unit to the hot water supply unit.

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