Air-conditioning hot water supply system, and control method and control device for air-conditioning hot water supply system

Abstract

This air-conditioning hot water supply system is provided with: an outdoor unit which is provided with a compressor that compresses a first heat medium and supplies the first heat medium; a hot water supply unit for generating warm water using the first heat medium supplied from the outdoor unit; an indoor unit that performs air conditioning using the first heat medium supplied from the outdoor unit; a blocking unit for blocking the first heat medium flowing to the indoor unit; and a control unit that performs control such that, when the first heat medium leaks from the indoor unit, the first heat medium flowing to the indoor unit is blocked by the blocking 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.

Description

Technical Field

[0001] This invention relates to an air conditioning hot water supply system, a control method for the air conditioning hot water supply system, and a control device. Background Technology

[0002] Patent document 1 discloses an air conditioning hot water supply system comprising: an outdoor unit; multiple indoor units each connected to the outdoor unit; and a hot water supply unit connected to the outdoor unit in a manner configured in parallel with the multiple indoor units.

[0003] Patent Document 2 discloses an air conditioner that connects an outdoor unit to multiple indoor units using refrigerant piping. Patent Document 2 also discloses an external mounting device comprising an expansion valve located on one of the multiple refrigerant piping connecting the indoor and outdoor units, and a solenoid valve located on the other. The expansion valve and solenoid valve are closed in the event of a refrigerant leak.

[0004] <Prior art documents> <Patent Documents> Patent Document 1: Japanese Patent Publication No. 2019-529857 Patent Document 2: Japanese Patent Application Publication No. 2012-013339 Summary of the Invention <Problem to be solved by this invention> In an air conditioning and hot water supply system that provides both air conditioning and hot water, the aim is to maintain the hot water supply function even in the event of refrigerant leakage in an indoor unit.

[0005] This invention provides a technique for continuing the operation of a hot water supply unit in the event of refrigerant leakage in an indoor unit.

[0006] <Methods for solving problems> The first viewpoint's air conditioning hot water supply system has the following features: An outdoor unit, which has a compressor for compressing a first heat medium and supplying the first heat medium; A hot water supply unit that uses the first heat medium supplied from the outdoor unit to generate warm water; An indoor unit that uses the first heat medium supplied from the outdoor unit for air conditioning; A shut-off unit, used to cut off the flow of the first heat medium to the indoor unit; and The control unit controls the flow of the first heat medium to the indoor unit to be cut off by the shut-off unit when a leak occurs in the first heat medium in the indoor unit, while continuing the operation of the compressor and continuing the supply of the first heat medium from the outdoor unit to the hot water supply unit.

[0007] According to the first viewpoint, the air conditioning hot water supply system can continue to operate the hot water supply unit even if a refrigerant leak occurs in the indoor unit.

[0008] The second viewpoint's air conditioning hot water supply system is based on the first viewpoint's air conditioning hot water supply system. The hot water supply unit has a cascaded heat medium loop that generates warm water through a second heat medium that has exchanged heat with the first heat medium.

[0009] The third viewpoint's air conditioning hot water supply system is based on the second viewpoint's air conditioning hot water supply system. When the first heat medium leaks in the indoor unit, the cascaded heat medium circuit continues the circulation of the second heat medium.

[0010] The fourth viewpoint's air conditioning hot water supply system is in the same way as the second or third viewpoint's air conditioning hot water supply system. The first heat transfer medium is R32. The second heat medium is 1234yf.

[0011] The air conditioning hot water supply system in viewpoint 5 is the same as the air conditioning hot water supply system in any one of viewpoints 1 to 4. The indoor unit is equipped with an expansion valve. The expansion valve functions as a shut-off valve in the shut-off unit.

[0012] The air conditioning hot water supply system of viewpoint 6 is the same as the air conditioning hot water supply system described in any one of viewpoints 1 to 5. After the cut-off unit is cut off, the amount m of the first heat medium released from the indoor unit satisfies Equation 1.

[0013]

Formula 1

[0014]

Formula 2

[0015] The air conditioning hot water supply system of viewpoint 7 is the same as the air conditioning hot water supply system in any one of viewpoints 1 to 6. It includes multiple indoor units and multiple cut-off units for each indoor unit. The control unit controls the supply of the first heat medium to the indoor unit where the first heat medium leaks, so that the cut-off unit cuts off the first heat medium and continues to supply the first heat medium to indoor units other than the indoor unit where the first heat medium leaks.

[0016] The air conditioning hot water supply system in viewpoint 8 is the same as the air conditioning hot water supply system in any one of viewpoints 1 to 7. The first heat medium is a slightly flammable refrigerant or a flammable refrigerant.

[0017] The air conditioning hot water supply system of viewpoint 9 is the same as the air conditioning hot water supply system described in any one of viewpoints 1 to 8. The first heat medium is R32.

[0018] The air conditioning hot water supply system of viewpoint 10 is the same as the air conditioning hot water supply system in any one of viewpoints 1 to 9. If the capacity of the indoor unit to which the shut-off unit is closed is greater than or equal to the capacity of the outdoor unit, the operation of the compressor is stopped.

[0019] The first viewpoint's control method for an air conditioning hot water supply system is a control method for an air conditioning hot water supply system, wherein the air conditioning hot water supply system comprises: An outdoor unit, which has a compressor for compressing a first heat medium and supplying the first heat medium; A hot water supply unit that uses the first heat medium supplied from the outdoor unit to generate warm water; An indoor unit that uses the first heat medium supplied from the outdoor unit for air conditioning; and The shut-off unit is used to cut off the flow of the first heat medium to the indoor unit. In this control method, when the first heat medium leaks in the indoor unit, the flow of the first heat medium to the indoor unit is cut off by the shut-off unit, and the operation of the compressor continues, so as to continue the supply of the first heat medium from the outdoor unit to the hot water supply unit.

[0020] According to the control method of the air conditioning hot water supply system in the first viewpoint, the hot water supply function can continue even if refrigerant leaks in the indoor unit.

[0021] The control device of the first point is used in an air conditioning hot water supply system, which includes: An outdoor unit, which has a compressor for compressing a first heat medium and supplying the first heat medium; A hot water supply unit that uses the first heat medium supplied from the outdoor unit to generate warm water; An indoor unit that uses the first heat medium supplied from the outdoor unit for air conditioning; and The shut-off unit is used to cut off the flow of the first heat medium to the indoor unit. The control device controls the flow of the first heat medium to the indoor unit to be cut off by the shut-off unit when the first heat medium leaks in the indoor unit, while the compressor continues to operate and the supply of the first heat medium from the outdoor unit to the hot water supply unit continues.

[0022] According to the control device of the first viewpoint, the hot water supply function can continue even if a refrigerant leak occurs in the indoor unit. Attached Figure Description

[0023] Figure 1 This is a diagram showing an outline of the structure of the air conditioning hot water supply system according to the first embodiment.

[0024] Figure 2 This is a diagram showing an outline of the outdoor unit included in the air conditioning hot water supply system according to the first embodiment.

[0025] Figure 3 This is a diagram showing an outline of the hot water supply unit included in the air conditioning hot water supply system according to the first embodiment.

[0026] Figure 4 This is a diagram showing an outline of the indoor unit and the shut-off unit included in the air conditioning hot water supply system according to the first embodiment.

[0027] Figure 5This is a diagram showing the hardware structure of the control unit included in the air conditioning hot water supply system according to the first embodiment.

[0028] Figure 6 This is a diagram showing an outline of the cooling and heating switching unit included in the air conditioning hot water supply system according to the first embodiment.

[0029] Figure 7 This is a flowchart illustrating the processing of the air conditioning hot water supply system according to the first embodiment.

[0030] Figure 8 This is a diagram showing a general outline of the structure of the air conditioning hot water supply system according to the second embodiment. Detailed Implementation

[0031] Hereinafter, embodiments will be described with reference to the accompanying drawings. Furthermore, in the descriptions and drawings relating to each embodiment, constituent elements having substantially the same or corresponding functional structures are sometimes omitted by using the same symbols, thus avoiding repeated descriptions. Additionally, for ease of understanding, the scales of various parts in the drawings may sometimes differ from the actual scales.

[0032] Implementation Method 1 The air conditioning hot water supply system according to the first embodiment will be described. The air conditioning hot water supply system according to the first embodiment includes an outdoor unit, a hot water supply unit, an indoor unit, a shut-off unit, and a control unit. The outdoor unit of the air conditioning hot water supply system according to the first embodiment includes a compressor that compresses a first heat medium and supplies the first heat medium. The hot water supply unit of the air conditioning hot water supply system according to the first embodiment uses the first heat medium supplied from the outdoor unit to generate warm water. The indoor unit of the air conditioning hot water supply system according to the first embodiment uses the first heat medium supplied from the outdoor unit for air conditioning. The shut-off unit of the air conditioning hot water supply system according to the first embodiment cuts off the flow of the first heat medium to the indoor unit. When the first heat medium leaks in the indoor unit, the control unit of the air conditioning hot water supply system according to the first embodiment controls the shut-off unit to cut off the flow of the first heat medium to the indoor unit. Furthermore, when the first heat medium leaks in the indoor unit, the control unit of the air conditioning hot water supply system according to the first embodiment controls the compressor to continue operating, continuing the supply of the first heat medium from the outdoor unit to the hot water supply unit.

[0033] Figure 1 This is a diagram showing an outline of the structure of an air conditioning hot water supply system 1, which is an example of an air conditioning hot water supply system according to the first embodiment.

[0034] [Air Conditioning Hot Water Supply System 1] The air conditioning hot water supply system 1 generates warm water (hot water supply) and conditions the air in a given space. The air conditioning hot water supply system 1 is a so-called heat pump type air conditioning hot water supply system. For example, the air conditioning hot water supply system 1 can supply hot water while heating, and can also supply hot water while cooling.

[0035] The air conditioning hot water supply system 1 includes an outdoor unit 10, a hot water supply unit 20, an indoor unit 30, a shut-off unit 40, and a control unit 50. Furthermore, the air conditioning hot water supply system 1 includes a heating / cooling switching unit 60a between the outdoor unit 10 and the hot water supply unit 20. Additionally, the air conditioning hot water supply system 1 includes a heating / cooling switching unit 60b between the outdoor unit 10 and the indoor unit 30. A detailed description of each component of the air conditioning hot water supply system 1 will be provided.

[0036] (Outdoor Unit 10) The outdoor unit 10 is described in detail. Figure 2 This is a diagram showing an outline of the outdoor unit 10 of an air conditioning hot water supply system 1, which is an example of an air conditioning hot water supply system according to the first embodiment.

[0037] The outdoor unit 10 supplies the first heat medium RF1 to both the hot water supply unit 20 and the indoor unit 30. The outdoor unit 10 is installed outdoors, for example on the roof or balcony of a building. Alternatively, the outdoor unit 10 may be installed underground. The outdoor unit 10 uses R32, instead of Freon, as the first heat medium RF1. Alternatively, propane may be used as the first heat medium RF1. Furthermore, R454B may also be used as the first heat medium RF1.

[0038] R32 is a slightly flammable refrigerant. Propane is a flammable refrigerant.

[0039] The outdoor unit 10 includes: a compressor 11, a gas-liquid separator 12, heat exchangers 13a and 13b, expansion valves 14a and 14b, four-way switching valves 15a, 15b and 15c, and a fan 16.

[0040] The compressor 11 compresses the first heat medium RF1. The compressor 11 is, for example, a scroll or rotary positive displacement compressor with a hermetically sealed structure having a built-in compressor motor. The compressor 11 compresses the low-pressure first heat medium RF1 that is drawn in. Then, the compressor 11 ejects the compressed first heat medium RF1.

[0041] The gas-liquid separator 12 temporarily stores the low-pressure first heat medium RF1 that is drawn into the compressor 11. By temporarily storing the first heat medium RF1, the gas-liquid separator 12 performs gas-liquid separation on the first heat medium RF1.

[0042] Heat exchangers 13a and 13b exchange heat between the first heat medium RF1 and the outside air, respectively. Heat exchangers 13a and 13b are, for example, cross-fin type or microchannel type heat exchangers.

[0043] Expansion valves 14a and 14b respectively reduce the pressure of the first hot medium RF1 flowing through them. Expansion valves 14a and 14b are, for example, electrically operated valves capable of adjusting their opening degree.

[0044] Four-way switching valves 15a, 15b, and 15c respectively switch the flow of the first hot medium RF1. Since the flow path of each of the four-way switching valves 15a, 15b, and 15c is blocked, they essentially function as three-way valves.

[0045] Fan 16 generates airflow through heat exchangers 13a and 13b. Fan 16 is, for example, an axial fan.

[0046] The outdoor unit 10 is connected to a liquid connecting pipe RL1, an intake gas connecting pipe RL2, and a high and low pressure gas connecting pipe RL3.

[0047] The air conditioning hot water supply system 1 generates warm 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 heating and cooling operations in the indoor unit 30 will be explained.

[0048] (1) Heating operation When the indoor unit 30 is in heating operation, the first heat medium RF1, which is compressed in the compressor 11, is discharged from the high and low pressure gas connecting pipe RL3 through the four-way switching valve 15c.

[0049] The first heat medium RF1 returning from the liquid connecting pipe RL1 branches to expansion valves 14a and 14b respectively. The branch of the first heat medium RF1 to expansion valve 14a is depressurized upon passing through expansion valve 14a. Then, after being depressurized in expansion valve 14a, the first heat medium RF1 evaporates by exchanging heat with outdoor air as it passes through heat exchanger 13a. Then, after evaporation in heat exchanger 13a, the first heat medium RF1 is drawn into compressor 11 through four-way switching valve 15a and gas-liquid separator 12. Similarly, the branch of the first heat medium RF1 to expansion valve 14b is depressurized upon passing through expansion valve 14b. Then, after being depressurized in expansion valve 14b, the first heat medium RF1 evaporates by exchanging heat with outdoor air as it passes through heat exchanger 13b. Then, after evaporation in heat exchanger 13a, the first heat medium RF1 is drawn into compressor 11 through four-way switching valve 15b and gas-liquid separator 12.

[0050] (2) Refrigeration operation (refrigeration + hot water supply) When the indoor unit 30 is operating in cooling mode, the first heat medium RF1, after being compressed in the compressor 11, branches to the four-way switching valve 15a and the four-way switching valve 15c, respectively. The first heat medium RF1 branching to the four-way switching valve 15a is condensed by exchanging heat with the outdoor air in the heat exchanger 13a. Then, the first heat medium RF1 condensed in the heat exchanger 13a is discharged from the liquid connecting pipe RL1 through the expansion valve 14a. The first heat medium RF1 branching to the four-way switching valve 15c is discharged from the high and low pressure gas connecting pipe RL3.

[0051] The first heat medium RF1 returning from the intake gas connecting pipe RL2 is drawn to the compressor 11 through the gas-liquid separator 12.

[0052] (Hot water supply unit 20) The hot water supply unit 20 uses the first heat medium RF1 supplied from the outdoor unit 10 to generate warm water.

[0053] Figure 3 This is a diagram showing an outline of the hot water supply unit 20 included in the air conditioning hot water supply system 1, which is an example of the air conditioning hot water supply system according to the first embodiment.

[0054] The hot water supply unit 20 includes a cascaded heat medium loop 20s involving a second heat medium RF2 that exchanges heat with the first heat medium RF1. The cascaded heat medium loop 20s generates warm water.

[0055] The hot water supply unit 20 is integrated with the outdoor unit 10, for example. The hot water supply unit 20 integrated with the outdoor unit 10 is installed outdoors, such as on the roof or balcony of a building. Alternatively, the hot water supply unit 20 may be installed underground. The hot water supply unit 20 uses 1234yf as a substitute for Freon as the second heat medium RF2. 1234yf is a slightly flammable refrigerant. Alternatively, 1234ze may also be used as the second heat medium RF2. The combination of the first heat medium RF1 and the second heat medium RF is not limited to the combination of R32 and 1234yf; for example, it may be any one of the combinations of R454B and 1234yf, RF454B and 1234ze, and R32 and 1234ze.

[0056] The hot water supply unit 20 includes: a compressor 21, a gas-liquid separator 22, a heat exchanger 23, a heat exchanger 24, an expansion valve 25, an expansion valve 26, a pump 27, a four-way switching valve 28, a check valve 29a, and a check valve 29b.

[0057] The compressor 21 compresses the second heat medium RF2. The compressor 21 is, for example, a scroll or rotary positive displacement compressor with a hermetically sealed structure having a built-in compressor motor. The compressor 21 compresses the low-pressure second heat medium RF2 that is drawn in. Then, the compressor 21 ejects the compressed second heat medium RF2.

[0058] The gas-liquid separator 22 temporarily stores the low-pressure second heat medium RF2 that is drawn into the compressor 21. The gas-liquid separator 22 performs gas-liquid separation on the second heat medium RF2 by temporarily storing it.

[0059] Heat exchanger 23 performs heat exchange between the first heat medium RF1 and the second heat medium RF2. Heat exchanger 23 is, for example, a plate or spiral heat exchanger.

[0060] Heat exchanger 24 performs heat exchange between the second heat medium RF2 and water. Heat exchanger 24 is, for example, a double-tube heat exchanger.

[0061] Expansion valve 25 reduces the pressure of the first heat medium RF1 passing through it. Expansion valve 26 reduces the pressure of the second heat medium RF2 passing through it. Expansion valves 25 and 26 are, for example, electrically operated valves capable of adjusting their opening degree.

[0062] Pump 27 delivers water to heat exchanger 24.

[0063] Four-way switching valve 28 switches the flow of the second heat medium RF2.

[0064] Check valve 29a prevents the second heat medium RF2 from flowing back to compressor 21. Check valve 29b prevents water from flowing back.

[0065] (Indoor Unit 30) The indoor unit 30 provides air conditioning for a given space RM.

[0066] Figure 4 This is a diagram showing an outline of the indoor unit 30 and the shut-off unit 40 of an air conditioning hot water supply system 1, which is an example of an air conditioning hot water supply system according to the first embodiment.

[0067] The indoor unit 30 includes a heat exchanger 31, an expansion valve 32, a detector 33, and a fan 34.

[0068] Heat exchanger 31 performs heat exchange between the first heat medium RF1 and air. Heat exchanger 31 is, for example, a cross-fin type or a microchannel type heat exchanger.

[0069] Expansion valve 32 reduces the pressure of the first hot medium RF1 passing through it. Expansion valve 32 is, for example, an electrically operated valve capable of adjusting its opening.

[0070] Detector 33 detects the first thermal medium RF1. Detector 33 detects leakage of the first thermal medium RF1 by detecting the first thermal medium RF1.

[0071] Fan 34 generates an airflow through heat exchanger 31. Fan 34 is, for example, a Sirocco fan.

[0072] (End of Unit 40) Cut-off unit 40 cuts off the first heat medium RF1 flowing from outdoor unit 10 to indoor unit 30.

[0073] The shut-off unit 40 includes shut-off valve 41 and shut-off valve 42. Shut-off valve 41 and shut-off valve 42 are, for example, electric valves.

[0074] For example, when the detector 33 of the indoor unit 30 detects a leak of the first heat medium RF1, the shut-off unit 40 closes the shut-off valves 41 and 42. Thus, the shut-off unit 40 cuts off the supply of the first heat medium RF1 to the indoor unit 30.

[0075] The amount of the first heat medium RF1 released from the indoor unit 30 after the cut-off unit 40 is cut off will be explained. In other words, the amount of the first heat medium RF1 remaining on the side from the cut-off unit 40 to the indoor unit 30 after the cut-off unit 40 is cut off will be explained.

[0076] After the cut-off unit 40 is closed, the amount m of the first heat medium RF1 released from the indoor unit 30 preferably satisfies formula A.

[0077]

Formula 3

[0078]

Formula 4

[0079] (Control Unit 50) The control unit 50 controls the outdoor unit 10, the hot water supply unit 20, the indoor unit 30, the heating and cooling switching unit 60a, and the heating and cooling switching unit 60b. Figure 5 This is a hardware structure diagram showing the hardware structure of the control unit 50 of the air conditioning hot water supply system 1, which is an example of the air conditioning hot water supply system according to the first embodiment.

[0080] The control unit 50 includes a control unit 51, RAM (Random Access Memory) 52, and ROM (Read Only Memory) 53. Furthermore, the control unit 50 includes a memory I / F (Interface) 54 and an external I / F 55. The control unit 51, RAM 52, ROM 53, memory I / F 54, and external I / F 55 are all connected to bus B1.

[0081] In the memory I / F 54, a storage medium 54a is connected, for example. In the external I / F 55, outdoor unit 10, hot water supply unit 20, indoor unit 30, heating and cooling switching unit 60a, and heating and cooling switching unit 60b are connected, for example.

[0082] The control unit 51 is a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The control unit 51 can also be an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). The control unit 51 executes programs to perform the various processes described in this specification. The control unit 51 is an arithmetic unit that reads programs (applications, application programs) from storage devices such as ROM 53 and storage medium 54a into RAM 52 and executes the processing. The control unit 51, RAM 52, and ROM 53 constitute a computer for controlling the air conditioning and hot water supply system 1.

[0083] RAM52 is a volatile semiconductor memory used for temporarily storing programs (applications, applications), etc.

[0084] ROM53 is, for example, a non-volatile semiconductor memory that can retain programs (applications, application programs) even when the power is cut off. ROM53 stores various settings such as programs that are executed at startup, including BIOS (Basic Input / Output System), OS (Operating System) settings, and network settings.

[0085] The memory I / F54 is an interface to external storage devices such as storage medium 54a.

[0086] Storage media 54a include, for example, SD (Secure Digital) memory cards, USB (Universal Serial Bus) memory, HDD (Hard Disk Drive), and SSD (Solid State Drive).

[0087] The external I / F55 is the interface connecting the peripheral equipment and the control unit 51. Through the external I / F55, the control unit 51 is connected to the outdoor unit 10, the hot water supply unit 20, the indoor unit 30, the heating and cooling switching unit 60a, and the heating and cooling switching unit 60b, respectively.

[0088] (Heating and cooling switching unit 60a and heating and cooling switching unit 60b) The cooling and heating switching unit 60a and the cooling and heating switching unit 60b respectively control the flow path of the first heat medium RF1, so that, for example, cooling, heating and hot water supply can be performed simultaneously.

[0089] Figure 6This diagram shows a general outline of the heating / cooling switching unit 60 included in the air conditioning hot water supply system 1, which is an example of the air conditioning hot water supply system according to the first embodiment. Furthermore, since heating / cooling switching units 60a and 60b have the same structure, heating / cooling switching units 60a and 60b will be described using the heating / cooling switching unit 60 as an example.

[0090] The heating and cooling switching unit 60 includes a heat exchanger 61, a control valve 62, a control valve 63, and a control valve 64.

[0091] The operation of the heating / cooling switching unit 60 in the indoor unit 30 when it is in heating and cooling operation respectively is explained.

[0092] (1) Heating operation When the indoor unit 30 is in heating operation, in the heating / cooling switching unit 60, which is connected to both the hot water supply unit 20 and the indoor unit 30, the control valve 63, connected to the high / low pressure gas connecting pipe RL3, is set to open. Furthermore, control valves 62 and 64 are set to close. By setting control valve 63 to open and control valves 62 and 64 to close, the first heat medium RF1 flowing from the high / low pressure gas connecting pipe RL3 flows out to the piping PL2, and the first heat medium RF1 flowing from the piping PL1 flows out to the liquid connecting pipe RL1.

[0093] (2) Refrigeration operation (refrigeration + hot water supply) When the indoor unit 30 is operating in cooling mode, in the heating / cooling switching unit 60 connected to the hot water supply unit 20, control valve 63, which is connected to the high / low pressure gas connecting pipe RL3, is set to open, while control valves 62 and 64 are set to close. By setting control valve 63 to open and control valves 62 and 64 to close, the first heat medium RF1 flowing in from the high / low pressure gas connecting pipe RL3 flows out to the piping PL2, and the first heat medium RF1 flowing in from the piping PL1 flows out to the liquid connecting pipe RL1.

[0094] In the heating / cooling switching unit 60 connected to the indoor unit 30, the control valve 64, which is connected to the intake gas connecting pipe RL2, is set to open. Furthermore, control valves 62 and 63 are respectively set to close. By setting control valve 64 to open and control valves 62 and 63 to close, the first heat medium RF1 flowing in from the liquid connecting pipe RL1 flows out to the piping PL1, and the first heat medium RF1 flowing in from the piping PL2 flows out to the intake gas connecting pipe RL2.

[0095] <Processing in the Air Conditioning Hot Water Supply System According to the First Embodiment> The processing in the air conditioning hot water supply system according to the first embodiment will be described. The processing will be explained using an air conditioning hot water supply system 1, which is an example of the air conditioning hot water supply system according to the first embodiment. More specifically, the processing in the control unit 51 of the control unit 50 included in the air conditioning hot water supply system 1 will be described. By describing the processing in the control unit 51 of the control unit 50 included in the air conditioning hot water supply system 1, the control method of the air conditioning hot water supply system according to this embodiment will be explained.

[0096] Figure 7 This is a flowchart illustrating the processing of an air conditioning hot water supply system 1, which is an example of an air conditioning hot water supply system according to the first embodiment.

[0097] (Step S10) First, the control unit 51 detects whether there is a leak of the first heat medium RF1 in the indoor unit 30 (heat medium leak detection process). Specifically, the control unit 51 obtains information on whether the detector 33 in the indoor unit 30 has detected the first heat medium RF1.

[0098] (Step S20) Next, the control unit 51 determines whether a leak has occurred in the first heat transfer medium RF1 in the indoor unit 30 based on the detection results in step S10. Specifically, if the detector 33 in the indoor unit 30 detects the first heat transfer medium RF1, the control unit 51 determines that a leak has occurred in the first heat transfer medium RF1 in the indoor unit 30. On the other hand, if the detector 33 in the indoor unit 30 does not detect the first heat transfer medium RF1, the control unit 51 determines that no leak has occurred in the first heat transfer medium RF1 in the indoor unit 30.

[0099] In step S20, if it is determined that a leak has occurred in the first heat medium RF1 in the indoor unit 30 ("Yes" in step S20), the control unit 51 causes the process to proceed to step S30. In step S20, if it is determined that no leak has occurred in the first heat medium RF1 in the indoor unit 30 ("No" in step S20), the control unit 51 returns to step S10 to repeat the process.

[0100] (Step S30) If it is determined that a leak has occurred in the first heat medium RF1 in the indoor unit 30 ("Yes" in step S20), the control unit 51 cuts off the flow of the first heat medium RF1 to the indoor unit 30 via the shut-off unit 40 (shut-off process). Specifically, the control unit 51 stops the supply of the first heat medium RF1 to the indoor unit 30 by closing the shut-off valves 41 and 42 provided in the shut-off unit 40.

[0101] At the time point S30, the compressor 11 in the outdoor unit 10 continues to operate. Furthermore, the outdoor unit 10 continues to supply the first heat medium RF1 to the hot water supply unit 20. Additionally, the circulation of the second heat medium RF2 continues in the hot water supply unit 20. Because the supply of the first heat medium RF1 to the hot water supply unit 20 continues, hot water supply can continue in the air conditioning hot water supply system 1.

[0102] Furthermore, in the above example, the control unit 51 closes both the shut-off valve 41 and the shut-off valve 42 provided in the shut-off unit 40, but the control unit 51 can also close the expansion valve 32 provided in the indoor unit 30. Additionally, when the expansion valve 32 is closed, the shut-off valve 42 in the shut-off unit 40 may or may not be present.

[0103] (Step S40) Next, the control unit 51 determines whether the capacity of the indoor unit 30 where the supply of the first heat medium RF1 has been stopped is greater than or equal to a given capacity (capacity determination process). Specifically, the control unit 51 obtains the capacity of the indoor unit 30 where the supply of the first heat medium RF1 has been cut off by the cut-off unit 40. Furthermore, the control unit 51 determines whether the capacity of the indoor unit 30 where the supply of the first heat medium RF1 has been cut off by the cut-off unit 40 is greater than or equal to a given capacity.

[0104] The given capacity can be appropriately determined to protect the compressor 11 in the outdoor unit 10. The given capacity is, for example, 50% of the capacity in the outdoor unit 10. Alternatively, the given capacity can also be, for example, any one of 20%, 25%, 30%, or 40% of the capacity in the outdoor unit 10.

[0105] In step S40, if the capacity of the indoor unit 30 where the supply of the first heat medium RF1 has been stopped is greater than or equal to a given capacity ("Yes" in step S40), the control unit 51 causes the process to proceed to step S50. In step S40, if the capacity of the indoor unit 30 where the supply of the first heat medium RF1 has been stopped is less than a given capacity ("No" in step S40), the control unit 51 terminates the process.

[0106] (Step S50) In step S40, if the capacity of the indoor unit 30, where the supply of the first heat medium RF1 has been stopped, is greater than or equal to a given capacity ("Yes" in step S40), the control unit 51 stops the operation of the compressor 11 in the outdoor unit 10 (compressor stop procedure). After the control unit 51 stops the operation of the compressor 11, the process ends.

[0107] According to the air conditioning hot water supply system of the first embodiment, the hot water supply function can continue even when a refrigerant leak occurs in the indoor unit. When a leak occurs in the first heat medium in the indoor unit, the air conditioning hot water supply system of the first embodiment cuts off the flow of the first heat medium to the indoor unit via a shut-off unit. Furthermore, when a leak occurs in the first heat medium in the indoor unit, the compressor continues to operate, and the supply of the first heat medium from the outdoor unit to the hot water supply unit continues. Therefore, according to the air conditioning hot water supply system of the first embodiment, the hot water supply function can continue even when a refrigerant leak occurs in the indoor unit.

[0108] Furthermore, an example of an air conditioning hot water supply system 1, which is an example of an air conditioning hot water supply system according to the first embodiment, has been described, in which there is one indoor unit 30. However, the air conditioning hot water supply system according to the first embodiment may also have multiple indoor units. Each of the multiple indoor units in the air conditioning hot water supply system according to the first embodiment may have a shut-off unit, or at least one indoor unit may have a shut-off unit.

[0109] In addition, when there are multiple indoor units, all of the indoor units can be operated in heating or cooling mode, or some of the indoor units can be operated in heating mode and others in cooling mode.

[0110] Furthermore, while an example of control via a control unit 51 has been described in the air conditioning hot water supply system 1, which is an example of an air conditioning hot water supply system according to the first embodiment, the function of the control unit in the air conditioning hot water supply system according to the first embodiment is not limited to being implemented via the control unit 51. For example, the function of the control unit in the air conditioning hot water supply system according to the first embodiment can also be implemented by any one of the control units provided in the outdoor unit, hot water supply unit, indoor unit, and shut-off unit of the air conditioning hot water supply system according to the first embodiment, or by the linkage of each control unit. Similarly, for example, it can also be implemented by the control unit provided in the cooling / heating switching unit 60 in the air conditioning hot water supply system 1, which is an example of an air conditioning hot water supply system according to the first embodiment.

[0111] Furthermore, the control unit in the air conditioning hot water supply system according to the first embodiment can also be provided separately as a control device for the air conditioning hot water supply system. In other words, it can also be a control device for an air conditioning hot water supply system including an outdoor unit, a hot water supply unit, an indoor unit, and a shut-off unit in the air conditioning hot water supply system according to the first embodiment. Then, when the first heat medium leaks in the indoor unit, the control device can control the shut-off unit to cut off the flow of the first heat medium to the indoor unit. In addition, when the first heat medium leaks in the indoor unit, the control device can control the compressor to continue operating, and continue the supply of the first heat medium from the outdoor unit to the hot water supply unit.

[0112] Implementation Method 2 The air conditioning hot water supply system according to the second embodiment includes multiple indoor units. Furthermore, each of the multiple indoor units in the air conditioning hot water supply system according to the second embodiment includes a shut-off unit. In other words, the air conditioning hot water supply system according to the second embodiment includes a shut-off unit provided for each indoor unit. Then, the control unit in the air conditioning hot water supply system according to the second embodiment controls the system to cut off the first heat medium through the shut-off unit in the indoor unit where the first heat medium leaks, and continues to supply the first heat medium to indoor units other than the indoor unit where the first heat medium leaks.

[0113] Figure 8 This is a diagram showing an outline of the structure of an air conditioning hot water supply system 2, which is an example of an air conditioning hot water supply system according to the second embodiment.

[0114] The air conditioning hot water supply system 2 includes indoor unit 30A and indoor unit 30B. In other words, the air conditioning hot water supply system 2 has two indoor units. Furthermore, the air conditioning hot water supply system 2 includes a shut-off unit 40A that cuts off the flow of the first heat medium RF1 to indoor unit 30A in the event of a leak in indoor unit 30A. Additionally, the air conditioning hot water supply system 2 includes a shut-off unit 40B that cuts off the flow of the first heat medium RF1 to indoor unit 30B in the event of a leak in indoor unit 30B.

[0115] Air conditioning hot water supply system 2 replaces control unit 50 in air conditioning hot water supply system 1 and has control unit 150. Control unit 150 has the functions of control unit 50 and performs control of cut-off unit 40A and cut-off unit 40B respectively.

[0116] In the air conditioning hot water supply system 2, sometimes the first heat medium RF1 leaks in either indoor unit 30A or indoor unit 30B, while the first heat medium RF1 does not leak in the other. The control unit in the control unit 150 controls the disconnection of either the cut-off unit 40A or the cut-off unit 40B connected to either of the leaking indoor unit 30A or indoor unit 30B. Then, the control unit in the control unit 150 controls the connection of either the cut-off unit 40A or the cut-off unit 40B connected to the other of the leaking indoor unit 30A or indoor unit 30B, ensuring that the connection is not disconnected.

[0117] The control unit in the control unit 150 can continue to operate indoor units that have not leaked by cutting off the connection only to the indoor unit where the leak has occurred.

[0118] In addition, in the example of the air conditioning hot water supply system 2, two indoor units are described, but the air conditioning hot water supply system 2 according to the second embodiment may also have three or more indoor units and the same number of shut-off units as the indoor units.

[0119] According to the air conditioning hot water supply system of the second embodiment, the hot water supply function can continue even if a refrigerant leak occurs in an indoor unit. Furthermore, according to the air conditioning hot water supply system of the second embodiment, even if a refrigerant leak occurs in an indoor unit, the operation of the indoor unit where the refrigerant has not leaked can continue.

[0120] In addition, when there are multiple indoor units, all of the indoor units can be operated in heating or cooling mode, or some of the indoor units can be operated in heating mode and others in cooling mode.

[0121] The embodiments described above are as follows; however, it should be understood that various changes in manner and detail are possible without departing from the spirit and scope of the claims. Various modifications and improvements, such as combinations or substitutions with some or all of the other embodiments, are possible.

[0122] This application claims priority to basic patent application No. 2023-170939 filed with the Japan Patent Office on September 29, 2023, the entire contents of which are incorporated herein by reference.

[0123] Symbol Explanation 1, 2: Air conditioning hot water supply system 10: Outdoor Units 11: Compressor 12: Gas-liquid separator 13a, 13b: Heat exchangers 14a, 14b: Expansion valves 15a, 15b, 15c: Four-way switching valves 16: Fan 20: Hot water supply unit 20s: Cascaded heat transfer medium loop 21: Compressor 22: Gas-liquid separator 23, 24: Heat exchangers 25, 26: Expansion valve 27: Pump 28: Four-way switching valve 29a, 29b: Check valves 30, 30A, 30B: Indoor Units 31: Heat exchanger 32: Expansion valve 33: Detector 34: Fan 40, 40A, 40B: Cut-off Units 41, 42: Stop valve 50, 150: Control Unit 51: Control Department 60, 60a, 60b: Heating and cooling switching unit 61: Heat exchanger 62, 63, 64: Control valves RF1: First heat transfer medium RF2: Second heat medium.

Claims

1. An air conditioning hot water supply system, comprising: An outdoor unit, which has a compressor for compressing a first heat medium and supplying the first heat medium; A hot water supply unit that uses the first heat medium supplied from the outdoor unit to generate warm water; An indoor unit that uses the first heat medium supplied from the outdoor unit for air conditioning; A shut-off unit, used to cut off the flow of the first heat medium to the indoor unit; and The control unit controls the flow of the first heat medium to the indoor unit to be cut off by the shut-off unit when a leak occurs in the first heat medium in the indoor unit, while continuing the operation of the compressor and continuing the supply of the first heat medium from the outdoor unit to the hot water supply unit.

2. The air conditioning hot water supply system according to claim 1, wherein, The hot water supply unit has a cascaded heat medium loop that generates warm water through a second heat medium that has exchanged heat with the first heat medium.

3. The air conditioning hot water supply system according to claim 2, wherein, When the first heat medium leaks in the indoor unit, the cascaded heat medium circuit continues the circulation of the second heat medium.

4. The air conditioning hot water supply system according to any one of claims 2 or 3, wherein, The first heat transfer medium is R32. The second heat medium is 1234yf.

5. The air conditioning hot water supply system according to any one of claims 1 to 4, wherein, The indoor unit is equipped with an expansion valve. The expansion valve functions as a shut-off valve in the shut-off unit.

6. The air conditioning hot water supply system according to any one of claims 1 to 5, wherein, After the cut-off unit is activated, the amount m of the first heat medium released from the indoor unit satisfies the following equation: Where max(a,b) is a function that returns the larger of a and b, min(a,b) is a function that returns the smaller of a and b, and LFL is the lower limit of flammability of the first heat medium, in kilograms per cubic meter (kg / m³). 3 A is the minimum room area, in square meters (m). 2 h0 is the floor height in meters (m), SF is a constant of 0.5, and the floor height h0 is obtained based on the following formula 4: Among them, h inst It is the height of the product's bottom surface from the floor, h rel It is the height of the opening from the bottom surface of the product, which is the cumulative opening area of ​​5 square centimeters, excluding holes with a size of 0.1 mm or less in this cumulative opening area.

7. The air conditioning hot water supply system according to any one of claims 1 to 6, wherein, The air conditioning hot water supply system includes multiple indoor units and multiple shut-off units for each indoor unit. The control unit controls the supply of the first heat medium to the indoor unit where the first heat medium leaks, so that the cut-off unit cuts off the first heat medium and continues to supply the first heat medium to indoor units other than the indoor unit where the first heat medium leaks.

8. The air conditioning hot water supply system according to any one of claims 1 to 7, wherein, The first heat medium is a slightly flammable refrigerant or a flammable refrigerant.

9. The air conditioning hot water supply system according to any one of claims 1 to 8, wherein, The first heat medium is R32.

10. The air conditioning hot water supply system according to any one of claims 1 to 9, wherein, If the capacity of the indoor unit to which the shut-off unit is closed is greater than or equal to the capacity of the outdoor unit, the operation of the compressor is stopped.

11. A control method for an air conditioning hot water supply system, wherein the air conditioning hot water supply system comprises: An outdoor unit, which has a compressor for compressing a first heat medium and supplying the first heat medium; A hot water supply unit that uses the first heat medium supplied from the outdoor unit to generate warm water; An indoor unit that uses the first heat medium supplied from the outdoor unit for air conditioning; as well as The shut-off unit is used to cut off the flow of the first heat medium to the indoor unit. In this control method, when the first heat medium leaks in the indoor unit, the flow of the first heat medium to the indoor unit is cut off by the shut-off unit, and the operation of the compressor continues, so as to continue the supply of the first heat medium from the outdoor unit to the hot water supply unit.

12. A control device for an air conditioning hot water supply system, the air conditioning hot water supply system comprising: An outdoor unit, which has a compressor for compressing a first heat medium and supplying the first heat medium; A hot water supply unit that uses the first heat medium supplied from the outdoor unit to generate warm water; An indoor unit that uses the first heat medium supplied from the outdoor unit for air conditioning; as well as The shut-off unit is used to cut off the flow of the first heat medium to the indoor unit. The control device controls the flow of the first heat medium to the indoor unit to be cut off by the shut-off unit when the first heat medium leaks in the indoor unit, while the compressor continues to operate and the supply of the first heat medium from the outdoor unit to the hot water supply unit continues.

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