Refrigeration cycle device

Abstract

Provided is a refrigeration cycle device capable of suppressing refrigerant leakage in a utilization unit while suppressing an increase in manufacturing cost. A refrigeration cycle device (100) is provided with a utilization unit (1), a heat source unit (2), a gas refrigerant communication pipe (6), and a first shut-off valve unit (3). The utilization unit (1) has a utilization heat exchanger (11). The heat source unit (2) has a compressor (21) and a heat source heat exchanger (23). A gas refrigerant communication pipe (6) is provided between the compressor (21) and the utilization heat exchanger (11). The first shut-off valve unit (3) is provided between the gas refrigerant communication pipe (6) and the utilization unit (1), and blocks the refrigerant flowing between the gas refrigerant communication pipe (6) and the utilization unit (1). The first shut-off valve unit (3) has: a plurality of first branch pipes (31) through which the refrigerant flowing between the gas refrigerant communication pipe (6) and the utilization unit (1) flows in parallel; and shut-off valves (33) that are provided to the plurality of first branch pipes (31), respectively.

Description

Technical Field

[0001] This disclosure relates to a refrigeration cycle apparatus. Background Technology

[0002] In the air conditioning system disclosed in Patent Document 1 (Japanese Patent Application Publication No. 2020-030043), a shut-off valve is installed between the indoor unit and the liquid piping, and between the indoor unit and the gas piping. When a refrigerant leak is detected in the indoor unit, the air conditioning system of Patent Document 1 closes the shut-off valve and blocks the flow of refrigerant to the indoor unit, thereby suppressing further refrigerant leakage in the air-conditioned space. Summary of the Invention

[0003] The technical problem that the invention aims to solve

[0004] In the air conditioning system of Patent Document 1, the refrigerant is blocked by only one shut-off valve in both the liquid and gas piping. Therefore, when the indoor unit has a large capacity, the shut-off valve may not be able to adequately block the flow of refrigerant.

[0005] By using a larger diameter shut-off valve, it is also possible to use a shut-off valve to block the flow of refrigerant in a larger capacity indoor unit. However, large-diameter shut-off valves are more expensive, which can easily lead to increased manufacturing costs.

[0006] The purpose of this disclosure is to provide a refrigeration cycle device that can suppress refrigerant leakage in the utilization unit while suppressing the increase in manufacturing costs.

[0007] Technical solutions adopted to solve technical problems

[0008] The first viewpoint's refrigeration cycle device includes a utilization unit, a heat source unit, a gaseous refrigerant connecting pipe, and a first shut-off valve unit.

[0009] The utilization unit includes a utilization heat exchanger. The heat source unit includes a compressor and a heat source heat exchanger. A gaseous refrigerant connecting pipe is disposed between the compressor and the utilization heat exchanger. A first shut-off valve unit is disposed between the gaseous refrigerant connecting pipe and the utilization unit to block the flow of refrigerant between the gaseous refrigerant connecting pipe and the utilization unit.

[0010] The first shut-off valve unit includes: a plurality of first branch pipes that allow refrigerant flowing between the gaseous refrigerant connecting pipe and the utilization unit to flow in parallel with each other; and shut-off valves respectively disposed on the plurality of first branch pipes.

[0011] In the refrigeration cycle unit, the refrigerant flowing between the gaseous refrigerant connecting pipe and the utilization unit is diverted to multiple first diversion pipes. Therefore, compared to the case where the refrigerant is not diverted, the amount of refrigerant passing through each shut-off valve is less. Thus, the shut-off valves can be designed to be miniaturized, thereby suppressing the increase in manufacturing costs associated with the enlargement of each shut-off valve. Therefore, the refrigeration cycle unit can suppress refrigerant leakage in the utilization unit while suppressing the increase in manufacturing costs.

[0012] The second viewpoint's refrigeration cycle device, based on the first viewpoint's refrigeration cycle device, further includes a liquid refrigerant connecting pipe and a second shut-off valve unit. The liquid refrigerant connecting pipe is located between the utilizing heat exchanger and the heat source heat exchanger. The second shut-off valve unit is located between the liquid refrigerant connecting pipe and the utilizing unit, blocking the refrigerant flowing between the liquid refrigerant connecting pipe and the utilizing unit.

[0013] The second shut-off valve unit has: a plurality of second branch pipes that allow refrigerant flowing between the liquid refrigerant connecting pipe and the utilization unit to flow in parallel with each other; and a plurality of shut-off valves, each disposed on a second branch pipe.

[0014] This refrigeration cycle unit also has a shut-off valve between the liquid refrigerant connecting pipe and the utilization unit, thus enabling it to further effectively suppress refrigerant leakage in the utilization unit while minimizing increases in manufacturing costs.

[0015] The third-view refrigeration cycle device, based on the first or second-view refrigeration cycle device, further includes a control unit for controlling the shut-off valves. When a refrigerant leak is detected in the utilization unit, the control unit closes all shut-off valves that block the flow of refrigerant between the utilization unit where the refrigerant leak was detected and the gaseous refrigerant connecting pipe or the liquid refrigerant connecting pipe.

[0016] This refrigeration cycle unit can suppress refrigerant leakage in the utilization unit in the event of a refrigerant leak.

[0017] The fourth viewpoint's refrigeration cycle device is based on any of the first to third viewpoints' refrigeration cycle devices, and the control unit includes a utilization unit control unit, a heat source unit control unit, and a shut-off valve control unit.

[0018] The utilization unit control unit is located in the utilization unit. The heat source unit control unit is located in the heat source unit. The shut-off valve control unit controls the shut-off valve.

[0019] When a refrigerant leak is detected in the utilization unit, the utilization unit control unit sends a first signal to the heat source unit control unit. Upon receiving the first signal, the heat source unit control unit sends a second signal to the shut-off valve control unit. Upon receiving the second signal, the shut-off valve control unit closes all shut-off valves that block the flow of refrigerant between the utilization unit where the refrigerant leak was detected and the gaseous or liquid refrigerant connecting pipe.

[0020] In this refrigeration cycle device, based on the signal sent from the control unit of the utilization unit that detects a refrigerant leak, all the shut-off valves corresponding to the shut-off valve control unit are closed. Therefore, the situation of mistakenly closing the shut-off valve corresponding to the utilization unit where no refrigerant leak has occurred is suppressed.

[0021] The refrigeration cycle device of the fifth viewpoint is based on the refrigeration cycle device of any of the first to third viewpoints, and the control unit has a utilization unit control unit and a flow cut-off valve control unit.

[0022] The utilization unit control unit is located within the utilization unit. The shut-off valve control unit controls the shut-off valve.

[0023] When a refrigerant leak is detected in the utilization unit, the utilization unit control unit sends a third signal to the shut-off valve control unit. When the shut-off valve control unit receives the third signal, it closes all the shut-off valves that block the flow of refrigerant between the utilization unit where the refrigerant leak was detected and the gas refrigerant connection pipe or the liquid refrigerant connection pipe.

[0024] In this refrigeration cycle apparatus, based on signals sent from the control unit of the utilization unit that detects refrigerant leakage, all shut-off valves corresponding to the shut-off valve control unit are closed. Therefore, the possibility of mistakenly closing shut-off valves corresponding to utilization units where no refrigerant leakage has occurred is suppressed. Thus, this refrigeration cycle apparatus can suppress refrigerant leakage in utilization units where refrigerant leakage has occurred.

[0025] The refrigeration cycle device of the sixth viewpoint is based on the refrigeration cycle device of any of the first to third viewpoints, and further includes a control unit 7 for controlling the shut-off valves. When an abnormality is detected in any of the multiple shut-off valves, the control unit closes all the remaining shut-off valves, and then stops the operation of any of the utilization units and heat source units.

[0026] According to this refrigeration cycle device, it is possible to prevent the shut-off valve from malfunctioning in the event of a refrigerant leak.

[0027] The refrigeration cycle unit of the seventh viewpoint is based on the refrigeration cycle unit of any of the first to sixth viewpoints, and utilizes a unit with a rated capacity of 10 horsepower or more.

[0028] Even with large-capacity utilization units of 10 horsepower or more, this refrigeration cycle system can suppress the increase in manufacturing costs.

[0029] The refrigeration cycle device of the eighth viewpoint is based on the refrigeration cycle device of any of the first to seventh viewpoints, and the shut-off valve is a needle valve.

[0030] This refrigeration cycle unit can suppress the increase in the diameter of the shut-off valve. Therefore, even when a needle valve is used as the shut-off valve, it can suppress the increase in manufacturing costs while suppressing refrigerant leakage in the utilization unit. Attached Figure Description

[0031] Figure 1 This is a schematic structural diagram of the refrigeration cycle apparatus 100 according to the first embodiment.

[0032] Figure 2 This is a block diagram of the control unit 7 of the refrigeration cycle apparatus 100 according to the first embodiment.

[0033] Figure 3 This is a flowchart illustrating the control process in case of refrigerant leakage.

[0034] Figure 4 This is a block diagram of the control unit 7 of the refrigeration cycle device 100 in Modified Example A.

[0035] Figure 5 This is a schematic structural diagram of the refrigeration cycle apparatus 100a according to the second embodiment. Detailed Implementation

[0036] <First Implementation>

[0037] (1) Overall structure

[0038] The refrigeration cycle unit 100 performs air conditioning operation (specifically, cooling and heating operation) on the target space by performing a vapor compression refrigeration cycle. The target space is, for example, the space within a building such as an office building, commercial facility, or residence. Furthermore, the refrigeration cycle unit is only one example of a refrigeration cycle unit; the heat exchanger disclosed herein can also be used in other refrigeration cycle units, such as refrigerators, freezers, water heaters, and underfloor heating systems.

[0039] The refrigeration cycle unit 100 mainly includes two utilization units 1, one heat source unit 2, two first shut-off valve units 3, two second shut-off valve units 4, one liquid refrigerant connecting pipe 5, one gaseous refrigerant connecting pipe 6, and one control unit 7. The liquid refrigerant connecting pipe 5 and the gaseous refrigerant connecting pipe 6 are refrigerant connecting pipes that connect the utilization units 1 and the heat source unit 2. In the refrigeration cycle unit 100, the utilization units 1 and the heat source unit 2 are connected via the liquid refrigerant connecting pipe 5 and the gaseous refrigerant connecting pipe 6 to form a refrigerant circuit 8. In other words, the liquid refrigerant connecting pipe 5 is located between the utilization heat exchanger 11 and the heat source heat exchanger 23 (both described later). Furthermore, the gaseous refrigerant connecting pipe 6 is located between the compressor 21 (described later) and the utilization heat exchanger 11.

[0040] The two utilization units 1 are respectively set in indoor A and indoor B, which are the spaces to be conditioned.

[0041] (2) Detailed structure

[0042] (2-1) Using Unit 1

[0043] like Figure 1 As shown, the utilization unit 1 mainly includes a heat exchanger 11, a fan 12, an expansion mechanism 13, a liquid refrigerant pipe 14, a gaseous refrigerant pipe 15, and a refrigerant sensor 16. The rated capacity of the utilization unit 1 is 10 horsepower or more.

[0044] Hereinafter, when it is necessary to distinguish between the two utilization units 1, the utilization unit 1 installed in room A will be referred to as utilization unit 1a, and the utilization unit 1 installed in room B will be referred to as utilization unit 1b. Similarly, sometimes the equipment of utilization unit 1a is indicated by adding the suffix 'a' to the reference numerals, and the equipment of utilization unit 1b is indicated by adding the suffix 'b' to the reference numerals.

[0045] The number of Unit 1s used is not limited to two; it can also be three or more.

[0046] (2-1-1) Using heat exchanger 11

[0047] Heat exchanger 11 is used to exchange heat between the refrigerant and the air transported by the airflow generated by fan 12. One end of heat exchanger 11 is connected to liquid refrigerant connecting pipe 5 via liquid refrigerant pipe 14, and the other end is connected to gaseous refrigerant connecting pipe 6 via gaseous refrigerant pipe 15.

[0048] (2-1-2) Using fan 12

[0049] Air is supplied to the heat exchanger 11 by the fan 12.

[0050] (2-1-3) Using expansion mechanism 13

[0051] The pressure and flow rate of the refrigerant flowing in the liquid refrigerant pipe 14 are regulated by the expansion mechanism 13. The expansion mechanism 13 is installed in the liquid refrigerant pipe 14.

[0052] (2-1-4) Refrigerant sensor 16

[0053] The refrigerant sensor 16 detects the refrigerant in the space where the unit 1 is installed, i.e., the air-conditioned space. In other words, the refrigerant sensor 16 detects refrigerant leaks in the air-conditioned space.

[0054] (2-2) Heat source unit 2

[0055] The heat source unit 2 mainly includes a compressor 21, a four-way reversing mechanism 22, a heat source heat exchanger 23, a heat source expansion mechanism 24, a liquid-side shut-off valve 25, a gas-side shut-off valve 26, and a heat source fan 27.

[0056] As refrigerant pipes connecting the various devices constituting the refrigerant circuit 8, the heat source unit 2 has an intake pipe P1, an exhaust pipe P2, a first gaseous refrigerant pipe P3, a liquid refrigerant pipe P4, and a second gaseous refrigerant pipe P5. The intake pipe P1 connects the four-way reversing mechanism 22 to the intake side of the compressor 21. The exhaust pipe P2 connects the exhaust side of the compressor 21 to the four-way reversing mechanism 22. The first gaseous refrigerant pipe P3 connects the four-way reversing mechanism 22 to the gas side of the heat source heat exchanger 23. The liquid refrigerant pipe P4 connects the liquid side of the heat source heat exchanger 23 to the liquid side shut-off valve 25. A heat source expansion mechanism 24 is provided on the liquid refrigerant pipe P4. The second gaseous refrigerant pipe P5 connects the four-way reversing mechanism 22 to the gas side shut-off valve 26.

[0057] (2-2-1) Compressor 21

[0058] The compressor 21 draws in low-pressure refrigerant from the refrigeration cycle through the suction pipe P1, compresses the refrigerant using a compression mechanism (not shown), and discharges it through the discharge pipe P2.

[0059] (2-2-2) Four-way reversing mechanism 22

[0060] The four-way reversing mechanism 22 switches the state of the refrigerant circuit 8 between cooling and heating operation by changing the direction of refrigerant flow. When the refrigerant circuit 8 is in cooling operation, the heat source heat exchanger 23 functions as a refrigerant radiator (condenser), and the heat exchanger 11 functions as a refrigerant evaporator. When the refrigerant circuit 8 is in heating operation, the heat source heat exchanger 23 functions as a refrigerant evaporator, and the heat exchanger 11 functions as a refrigerant condenser.

[0061] When the four-way reversing mechanism 22 sets the refrigerant circuit 8 to the refrigeration operation state, the four-way reversing mechanism 22 connects the suction pipe P1 to the second gaseous refrigerant pipe P5 and connects the discharge pipe P2 to the first gaseous refrigerant pipe P3 (see reference). Figure 1 (Solid line within the four-way reversing mechanism 22). When the four-way reversing mechanism 22 sets the refrigerant circuit 8 to heating operation, the four-way reversing mechanism 22 connects the suction pipe P1 to the first gaseous refrigerant pipe P3 and connects the discharge pipe P2 to the second gaseous refrigerant pipe P5 (see reference). Figure 1 (The dashed line inside the Zhongsitong reversing mechanism 22).

[0062] (2-2-3) Heat source heat exchanger 23

[0063] The heat exchanger 23 allows the refrigerant flowing inside to exchange heat with a heat source (such as the air at the location where the heat source unit 2 is installed).

[0064] (2-2-4) Heat source expansion mechanism 24

[0065] The heat source expansion mechanism 24 regulates the pressure and flow rate of the refrigerant flowing in the liquid refrigerant pipe P4.

[0066] (2-2-5) Liquid-side shut-off valve 25 and gas-side shut-off valve 26

[0067] The liquid-side shut-off valve 25 is a valve located at the connection between the liquid refrigerant pipe P4 and the liquid refrigerant connecting pipe P5. The gas-side shut-off valve 26 is a valve located at the connection between the second gas refrigerant pipe P5 and the gas refrigerant connecting pipe 6. Both the liquid-side shut-off valve 25 and the gas-side shut-off valve 26 are opened during the operation of the refrigeration cycle unit 100.

[0068] (2-2-6) Heat source fan 27

[0069] The heat source fan 27 supplies external air, which serves as a heat source, to the heat source heat exchanger 23.

[0070] (2-3) First flow interruption valve unit 3

[0071] The first flow-stop valve unit 3 is disposed between the gas refrigerant connecting pipe 6 and the utilization unit 1, and blocks the refrigerant flowing between the gas refrigerant connecting pipe 6 and the utilization unit 1. The first flow-stop valve unit 3 is disposed outside the utilization unit 1.

[0072] The first flow interruption valve unit 3 has multiple first flow dividers 31 and multiple first flow interruption valves 33.

[0073] The plurality of first diversion pipes 31 are piping that allows the refrigerant flowing between the gaseous refrigerant connecting pipe 6 and the utilization unit 1 to flow in parallel with each other. The refrigerant flowing between the gaseous refrigerant connecting pipe 6 and the utilization unit 1 is diverted and flows in the plurality of first diversion pipes 31. In this embodiment, the first shut-off valve unit 3 has two first diversion pipes 31.

[0074] First shut-off valves 33 are respectively provided on multiple first branch pipes 31. The flow of refrigerant in the first branch pipes 31 is blocked by closing the first shut-off valves 33. In other words, the flow of refrigerant between unit 1 and the gaseous refrigerant connecting pipe 6 is blocked by closing all the first shut-off valves 33. In principle, the first shut-off valves 33 remain open when the refrigerant sensor 16 does not detect a refrigerant leak. In this embodiment, the first shut-off valve unit 3 has two first shut-off valves 33.

[0075] Although not limited, the first shut-off valve 33 is a needle valve. In addition, the number of the first diverter pipe 31 and the first shut-off valve 33 is not limited to two, but can also be three or more.

[0076] Hereinafter, when it is necessary to distinguish between the two first shut-off valve units 3, the first shut-off valve unit 3 installed in room A will be referred to as first shut-off valve unit 3a, and the first shut-off valve unit 3 installed in room B will be referred to as first shut-off valve unit 3b. Similarly, sometimes the equipment of the first shut-off valve unit 3a is indicated by adding the suffix 'a' to the reference numerals, and the equipment of the first shut-off valve unit 3b is indicated by adding the suffix 'b' to the reference numerals.

[0077] (2-4) Second flow interruption valve unit 4

[0078] The second shut-off valve unit 4 is disposed between the liquid refrigerant connecting pipe 5 and the utilization unit 1, and blocks the refrigerant flowing between the liquid refrigerant connecting pipe 5 and the utilization unit 1. The second shut-off valve unit 4 is disposed outside the utilization unit 1.

[0079] The second flow interruption valve unit 4 has multiple second flow dividers 41 and multiple second flow interruption valves 43.

[0080] The plurality of second diversion pipes 41 are piping that allows the refrigerant flowing between the liquid refrigerant connecting pipe 5 and the utilization unit 1 to flow in parallel with each other. The refrigerant flowing between the liquid refrigerant connecting pipe 5 and the utilization unit 1 is diverted and flows in the plurality of second diversion pipes 41. In this embodiment, the second shut-off valve unit 4 has two second diversion pipes 41.

[0081] Second shut-off valves 43 are respectively provided on multiple second branch pipes 41. The flow of refrigerant in the second branch pipes 41 is blocked by closing the second shut-off valves 43. In other words, the flow of refrigerant between unit 1 and liquid refrigerant connecting pipe 5 is blocked by closing all the second shut-off valves 43. In principle, the second shut-off valves 43 remain open when the refrigerant sensor 16 does not detect a refrigerant leak. In this embodiment, the second shut-off valve unit 4 has two second shut-off valves 43.

[0082] Although not limited, the second shut-off valve 43 is a needle valve. In addition, the number of the second diverter pipe 41 and the second shut-off valve 43 is not limited to two, and can also be three or more.

[0083] Hereinafter, when it is necessary to distinguish between the two second shut-off valve units 4, the second shut-off valve unit 4 installed in room A will be referred to as second shut-off valve unit 4a, and the second shut-off valve unit 4 installed in room B will be referred to as second shut-off valve unit 4b. Similarly, sometimes the equipment of the second shut-off valve unit 4a is indicated by adding the suffix 'a' to the reference numerals, and the equipment of the second shut-off valve unit 4b is indicated by adding the suffix 'b' to the reference numerals.

[0084] (2-5) Control Unit 7

[0085] The controller 7 controls the operation of various devices constituting the refrigeration cycle unit 100. For example... Figure 2 As shown, the control unit 7 is electrically connected to the compressor 21, the four-way reversing mechanism 22, the heat source expansion mechanism 24, the heat source fan 27, the utilizing fan 12, the utilizing expansion mechanism 13, the refrigerant sensor 16, the first shut-off valve 33, and the second shut-off valve 43 in a manner capable of sending and receiving signals. The control unit 7 can also be electrically connected to various sensors (not shown) installed in the utilizing unit 1 and the heat source unit 2. The control unit 7 can also communicate with a remote control (not shown) operated by the user of the refrigeration cycle unit 100.

[0086] The control unit 7 is implemented by a computer. The control unit 7 includes a control processing unit and a storage unit (both omitted from the diagram). The control processing unit is a processor such as a CPU or GPU. The control processing unit reads the program stored in the storage unit and performs prescribed image processing or computational processing according to the program. Furthermore, the control processing unit writes the computation results to the storage unit according to the program, or reads information stored in the storage unit according to the program.

[0087] (3) Overall movement

[0088] (3-1) Air conditioner operation

[0089] During air conditioning operation, the control unit 7 controls the operation of various devices constituting the refrigeration cycle unit 100 as described below.

[0090] (3-1-1) Refrigeration Operation

[0091] When the start of refrigeration operation is indicated via remote control or other means, the control unit 7 controls the operation of the four-way reversing mechanism 22, switching the state of the refrigerant circuit 8 to a state where the heat source heat exchanger 23 functions as a refrigerant radiator (condenser) and the heat exchanger 11 functions as a refrigerant evaporator. Specifically, the control unit 7 controls the operation of the four-way reversing mechanism 22 to connect the suction pipe P1, which is connected to the suction side of the compressor 21, to the second gaseous refrigerant pipe P5, which connects the four-way reversing mechanism 22 to the gas-side shut-off valve 26. Furthermore, the control unit 7 controls the operation of the four-way reversing mechanism 22 to connect the discharge pipe P2, which is connected to the discharge side of the compressor 21, to the first gaseous refrigerant pipe P3, which connects the four-way reversing mechanism 22 to the gas side of the heat source heat exchanger 23 (see reference). Figure 1 (Solid line within the four-way reversing mechanism 22). During cooling operation, the control unit 7 operates the compressor 21, the heat source fan 27, and the utilization fan 30. Furthermore, during cooling operation, the control unit 7 adjusts the speeds of the compressor 21, the heat source fan 27, and the utilization fan 30, as well as the opening degrees of the heat source expansion mechanism 24 and the utilization expansion mechanism 13, based on measurements from various sensors.

[0092] When the control unit 7 controls the operation of various devices in the refrigeration cycle unit 100, low-pressure gaseous refrigerant of the refrigeration cycle is drawn into the compressor 21 and compressed to high pressure, and then discharged from the compressor 21. The high-pressure gaseous refrigerant discharged from the compressor 21 is transported to the heat source heat exchanger 23 via the four-way reversing mechanism 22. The high-pressure gaseous refrigerant transported to the heat source heat exchanger 23 dissipates heat by exchanging heat with the air supplied by the heat source fan 27, which acts as a cooling source, in the heat source heat exchanger 23, which functions as a refrigerant radiator, and becomes high-pressure liquid refrigerant. After dissipating heat in the heat source heat exchanger 23, the high-pressure liquid refrigerant is transported to the heat source expansion mechanism 24 via the liquid refrigerant pipe P4. In the heat source expansion mechanism 24, the high-pressure liquid refrigerant is depressurized and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant, after being depressurized by the heat source expansion mechanism 24, is transported to the utilization expansion mechanism 13 of the utilization unit 1 via the liquid refrigerant pipe P4, the liquid-side shut-off valve 25, the liquid refrigerant connecting pipe 5, and the second shut-off valve unit 4. The low-pressure gas-liquid two-phase refrigerant is further depressurized in the utilization expansion mechanism 13 and transported to the utilization heat exchanger 11. The low-pressure gas-liquid two-phase refrigerant transported to the utilization heat exchanger 11, which functions as an evaporator for the refrigerant, exchanges heat with the air supplied by the utilization fan 30 and evaporates. At this time, the air cooled by the heat exchange with the refrigerant is supplied to the air-conditioned space, thereby cooling the air-conditioned space. The low-pressure gaseous refrigerant, after evaporation in the utilization heat exchanger 11, passes through the first shut-off valve unit 3, the gaseous refrigerant connecting pipe 6, the gas-side shut-off valve 26, the four-way reversing mechanism 22, and is drawn back into the compressor 21.

[0093] (3-1-2) Heating Operation

[0094] When the start of heating operation is indicated via remote control or other means, the control unit 7 controls the operation of the four-way reversing mechanism 22, switching the state of the refrigerant circuit 8 to a state where the heat source heat exchanger 23 functions as the refrigerant evaporator and the heat exchanger 11 functions as the refrigerant radiator (condenser). Specifically, the control unit 7 controls the operation of the four-way reversing mechanism 22 to connect the suction pipe P1 to the first gaseous refrigerant pipe 119 and the discharge pipe P2 to the second gaseous refrigerant pipe P5 (see reference). Figure 1 (The dashed line within the four-way reversing mechanism 22). During heating operation, the control unit 7 operates the compressor 21, the heat source fan 27, and the utilization fan 30. Furthermore, during heating operation, the control unit 7 adjusts the speeds of the compressor 21, the heat source fan 27, and the utilization fan 30, as well as the opening degrees of the heat source expansion mechanism 24 and the utilization expansion mechanism 13, based on measurements from various sensors.

[0095] When the control unit 7 controls the operation of various devices in the refrigeration cycle unit 100, low-pressure gaseous refrigerant of the refrigeration cycle is drawn into the compressor 21 and compressed to high pressure, and then discharged from the compressor 21. The high-pressure gaseous refrigerant discharged from the compressor 21 is transported to the utilization heat exchanger 11 of the utilization unit 1 through the four-way reversing mechanism 22, the gas-side shut-off valve 26, the gaseous refrigerant connecting pipe 6, and the first shut-off valve unit 3. In the utilization heat exchanger 11, which functions as a radiator (condenser) for refrigerant, the high-pressure gaseous refrigerant exchanges heat with the air supplied by the utilization fan 30 and dissipates heat, becoming high-pressure liquid refrigerant. At this time, the air heated by the heat exchange with the refrigerant is supplied to the air-conditioned space, thereby heating the air-conditioned space. After dissipating heat in the utilization heat exchanger 11, the high-pressure liquid refrigerant is depressurized in the utilization expansion mechanism 13 and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant is conveyed to the heat source expansion mechanism 24 via the second shut-off valve unit 4, the liquid refrigerant connecting pipe 5, the liquid-side shut-off valve 25, and the liquid refrigerant pipe P4. The refrigerant conveyed to the heat source expansion mechanism 24 is depressurized and further depressurized. The low-pressure gas-liquid two-phase refrigerant, depressurized in the heat source expansion mechanism 24, is conveyed to the heat source heat exchanger 23 via the liquid refrigerant pipe P4. The low-pressure gas-liquid two-phase refrigerant conveyed to the heat source heat exchanger 23, which functions as an evaporator, exchanges heat with air supplied by the heat source fan 27 as a heating source, evaporates, and becomes a low-pressure gaseous refrigerant. The low-pressure refrigerant, after evaporation in the heat source heat exchanger 23, passes through the four-way reversing mechanism 22 and is drawn back into the compressor 21.

[0096] (3-2) Actions when refrigerant leaks

[0097] When the control unit 7 detects a refrigerant leak in any of the multiple utilization units 1 (in other words, when the refrigerant sensor 16 detects refrigerant), it closes all flow-stopping valves (specifically, all first flow-stopping valves 33 and all second flow-stopping valves 43) that block the flow of refrigerant between the utilization unit 1 where the refrigerant leak was detected and the gas refrigerant connecting pipe 6 or the liquid refrigerant connecting pipe 5.

[0098] Reference Figure 3 The flowchart below details the control procedure in case of refrigerant leakage. This control procedure begins simultaneously with the startup of the refrigeration cycle unit 100.

[0099] In step S10, the control unit 7 determines whether a refrigerant leak is detected in any of the multiple utilization units 1. Specifically, it determines whether the refrigerant sensor 16 detects refrigerant. If the control unit 7 determines that refrigerant has been detected (Yes), the process proceeds to step S11. If the control unit 7 does not determine that refrigerant has been detected (No), the process proceeds to step S10.

[0100] In step S11, the control unit 7 closes all the first shut-off valves 33 and all the second shut-off valves 43 of the refrigerant utilization unit 1 that have detected the refrigerant, and ends the control process.

[0101] For example, when a refrigerant leak is detected by the refrigerant sensor 16a of unit 1a, the control unit 7 closes both first shut-off valves 33a and both second shut-off valves 43b.

[0102] (4) Characteristics

[0103] (4-1)

[0104] The refrigeration cycle device 100 includes a utilization unit 1, a heat source unit 2, a gaseous refrigerant connecting pipe 6, and a first shut-off valve unit 3.

[0105] The utilization unit 1 includes a utilization heat exchanger 11. The heat source unit 2 includes a compressor 21 and a heat source heat exchanger 23. A gaseous refrigerant connecting pipe 6 is disposed between the compressor 21 and the utilization heat exchanger 11. A first shut-off valve unit 3 is disposed between the gaseous refrigerant connecting pipe 6 and the utilization unit 1 to block the flow of refrigerant between the gaseous refrigerant connecting pipe 6 and the utilization unit 1.

[0106] The first shut-off valve unit 3 includes: a plurality of first diversion pipes 31, which allow refrigerant flowing between the gaseous refrigerant connecting pipe 6 and the utilization unit 1 to flow in parallel with each other; and shut-off valves 33, which are respectively disposed on the plurality of first diversion pipes 31.

[0107] In the refrigeration cycle apparatus 100, the refrigerant flowing between the gaseous refrigerant connecting pipe 6 and the utilization unit 1 is diverted to a plurality of first diversion pipes 31. Therefore, compared with the case where the refrigerant is not diverted, the amount of refrigerant passing through each shut-off valve 33 is less. Therefore, the shut-off valves 33 can be designed to be miniaturized, thereby suppressing the increase in manufacturing costs associated with the enlargement of each shut-off valve 33. Thus, the refrigeration cycle apparatus 100 can suppress refrigerant leakage in the utilization unit 1 while suppressing the increase in manufacturing costs.

[0108] (4-2)

[0109] The refrigeration cycle unit 100 also includes a liquid refrigerant connecting pipe 5 and a second shut-off valve unit 4. The liquid refrigerant connecting pipe 5 is disposed between the utilizing heat exchanger 11 and the heat source heat exchanger 23. The second shut-off valve unit 4 is disposed between the liquid refrigerant connecting pipe 5 and the utilizing unit 1 to block the refrigerant flowing between the liquid refrigerant connecting pipe 5 and the utilizing unit 1.

[0110] The second shut-off valve unit 4 includes: a plurality of second branch pipes 41, which allow the refrigerant flowing between the liquid refrigerant connecting pipe 5 and the utilization unit 1 to flow in parallel with each other; and a plurality of shut-off valves 43, which are respectively disposed on the second branch pipes 41.

[0111] The refrigeration cycle unit 100 also has a shut-off valve 43 between the liquid refrigerant connecting pipe 5 and the utilization unit 1, so as to effectively suppress refrigerant leakage in the utilization unit 1 while suppressing the increase in manufacturing costs.

[0112] (4-3)

[0113] The refrigeration circulation unit 100 also includes a control unit 7 that controls the shut-off valves 33 and 43.

[0114] When a refrigerant leak is detected in the utilization unit 1, the control unit 7 closes all the shut-off valves 33 and 43 that block the flow of refrigerant between the utilization unit 1 where the refrigerant leak was detected and the gas refrigerant connecting pipe 6 or the liquid refrigerant connecting pipe 5.

[0115] The refrigeration cycle unit 100 can suppress refrigerant leakage in the utilization unit 1 in the event of a refrigerant leak.

[0116] (4-4)

[0117] The rated capacity of Unit 1 is 10 horsepower or more.

[0118] Generally, the larger the rated capacity of the utilization unit 1, the more refrigerant flows between the utilization unit 1 and the liquid refrigerant connecting pipe 5 or the gaseous refrigerant connecting pipe 6, and the larger the diameter of the shut-off valve used is designed. As a result, the manufacturing cost of the shut-off valve used in the utilization unit 1 with a large rated capacity tends to increase. Even if the refrigeration cycle unit 1 has a large rated capacity utilization unit 1 with a rated capacity of 10 horsepower or more, the manufacturing cost can be kept low.

[0119] (4-5)

[0120] The first shut-off valve 33 and the second shut-off valve 43 are needle valves.

[0121] Needle valves tend to be more difficult to suppress leakage when closed as their orifice increases. While this leakage can be suppressed by improving the manufacturing precision of the valve, this increases manufacturing costs. The refrigeration cycle unit 100 can suppress the use of larger orifice sizes for the shut-off valves 33 and 43. Therefore, even when using needle valves, it is possible to suppress refrigerant leakage in the utilization unit 1 while minimizing the increase in manufacturing costs.

[0122] (5) Variations

[0123] (5-1) Variation 1A

[0124] The refrigeration cycle unit 100 may also exclude the second shut-off valve unit 4. In other words, the refrigeration cycle unit 100 may also include only the first shut-off valve unit 3.

[0125] (5-2) Variation 1B

[0126] The control unit 7 may also include a utilization unit control unit 17, a heat source unit control unit 28, and a flow cut-off valve control unit 34.

[0127] like Figure 4 As shown, the unit control unit 17 controls the fan 12 and the expansion mechanism 13. The unit control unit 17 is electrically connected to the fan 12, the expansion mechanism 13, the refrigerant sensor 16, and the heat source unit control unit 28 in a manner that enables the transmission and reception of signals.

[0128] The heat source unit control unit 28 controls the compressor 21, the four-way reversing mechanism 22, the heat source expansion mechanism 24, and the heat source fan 27. The heat source unit control unit 28 is electrically connected to the compressor 21, the four-way reversing mechanism 22, the heat source expansion mechanism 24, the heat source fan 27, and the unit control unit 17 in a manner that enables the transmission and reception of signals.

[0129] The shut-off valve control unit 34 controls the first shut-off valve 33 and the second shut-off valve 43. The shut-off valve control unit 34 is electrically connected to the first shut-off valve 33, the second shut-off valve 43, and the heat source unit control unit 28 in a manner that enables the transmission and reception of signals.

[0130] In the refrigeration cycle apparatus 100 of Modification 1B, when the refrigerant sensor 16 of the utilization unit 1 detects refrigerant, the unit control unit 17 sends a first signal to the heat source unit control unit 28. Upon receiving the first signal from the utilization unit control unit 17, the heat source unit control unit 28 sends a second signal to the shut-off valve control unit 34. Upon receiving the second signal from the heat source unit control unit 28, the shut-off valve control unit 34 closes all first shut-off valves 33 and all second shut-off valves 43 that block the flow of refrigerant between the utilization unit where a refrigerant leak has been detected, the utilization unit 1 where a refrigerant leak has been detected, and the gas refrigerant connecting pipe 6 or the liquid refrigerant connecting pipe 5.

[0131] In the refrigeration cycle apparatus 100 of Modified Example 1B, based on the signal sent from the utilization unit control unit 17 that detects refrigerant leakage, the shut-off valve control unit 34 closes all corresponding first shut-off valves 33 and all second shut-off valves 43. Therefore, it is possible to suppress the situation where the first shut-off valves 33 and second shut-off valves 43 corresponding to the utilization unit 1 where no refrigerant leakage has occurred are mistakenly closed.

[0132] Furthermore, the refrigeration cycle apparatus 100 of Modified Example 1B does not require a new communication line to be installed between the utilization unit control unit 17 and the shut-off valve control unit 34. In addition, according to the refrigeration cycle apparatus 100 of Modified Example 1B, the heat source unit control unit 28 can uniformly control the utilization unit 1, the first shut-off valve unit 3, and the second shut-off valve unit 4.

[0133] (5-3) Variation 1C

[0134] The unit control unit 17 can also be electrically connected to the shut-off valve control unit 34 in a manner that enables the transmission and reception of signals.

[0135] In the refrigeration cycle apparatus 100 of Modification 1C, when the refrigerant sensor 16 of the utilization unit 1 detects refrigerant, the unit control unit 17 sends a third signal to the shut-off valve control unit 34. Upon receiving the third signal from the heat source unit control unit 28, the shut-off valve control unit 34 closes all first shut-off valves 33 and all second shut-off valves 43 that block the flow of refrigerant between the utilization unit 1 (where a refrigerant leak has been detected) and the gas refrigerant connecting pipe 6 or the liquid refrigerant connecting pipe 5.

[0136] In the refrigeration cycle apparatus 100 of Modified Example 1C, based on the signal sent from the utilization unit control unit 17 that detects refrigerant leakage, the shut-off valve control unit 34 closes all corresponding first shut-off valves 33 and all second shut-off valves 43. Therefore, it is possible to suppress the situation where the first shut-off valves 33 and second shut-off valves 43 corresponding to the utilization unit 1 where no refrigerant leakage has occurred are mistakenly closed.

[0137] Furthermore, in the refrigeration cycle device 100 of Modified Example 1C, a signal is directly sent from the unit control unit 17 to the corresponding shut-off valve control unit 34, thus enabling rapid suppression of refrigerant leakage.

[0138] (5-4) Variation 1D

[0139] The control unit 7 can also close the first shut-off valves 33 and second shut-off valves 43 corresponding to all remaining utilization units 1 when it detects an abnormality in any of the multiple first shut-off valves 33 and multiple second shut-off valves 43, thereby stopping the operation of any of the utilization units 1 and the heat source units 2.

[0140] Here, the abnormality of any one of the first shut-off valve 33 and the plurality of second shut-off valves 43 is not limited, such as a communication abnormality or disconnection detected by not receiving an ack response to the signal sent by the control unit 7.

[0141] The refrigeration cycle device 100 of Modified Example 1D can prevent the first shut-off valve 33 or the second shut-off valve 43 from failing to operate in the event of refrigerant leakage.

[0142] (5-5) Variation 1E

[0143] In the refrigeration cycle device 100, the first shut-off valve unit 3 and the second shut-off valve unit 4 are disposed outside the utilization unit 1, but the placement of the first shut-off valve unit 3 and the second shut-off valve unit 4 is not limited. Alternatively, at least one of the first shut-off valve unit 3 and the second shut-off valve unit 4 may be disposed inside the utilization unit 1 (more specifically, inside the housing (not shown) of the utilization unit 1).

[0144] (5-6) Variation Example 1F

[0145] In the refrigeration cycle device 100, a first shut-off valve unit 3 and a second shut-off valve unit 4 are provided for all of the multiple utilization units 1. However, it is also possible to omit the first shut-off valve unit 3 and the second shut-off valve unit 4 for a portion of the multiple utilization units 1. For example, the first shut-off valve unit 3 and the second shut-off valve unit 4 may not be provided in a portion of the multiple utilization units 1, and instead, a shut-off valve may be directly provided on the liquid refrigerant pipe 14 and the gaseous refrigerant pipe 15.

[0146] (5-7) Variation 1G

[0147] The rated capacity of the utilization unit 1 can also be less than 10 horsepower. In this case, either the first shut-off valve unit 3 or the second shut-off valve unit 4 can be omitted for utilization units 1 with a rated capacity of less than 10 horsepower.

[0148] <Second Implementation>

[0149] (1) Overall structure

[0150] Next, the refrigeration cycle apparatus 100a of the second embodiment will be described. Hereinafter, the description will focus on the differences between the refrigeration cycle apparatus 100 and the refrigeration cycle apparatus 100a, and descriptions of the same or corresponding features and known technologies will sometimes be omitted.

[0151] The refrigeration cycle unit 100a is capable of simultaneous heating and cooling operation, in which a portion of the multiple utilization units 1 operate in heating mode while the remaining utilization units 1 operate in cooling mode. The refrigeration cycle unit 100a includes a high-pressure gas refrigerant connecting pipe 6a and a low-pressure gas refrigerant connecting pipe 6b, which serve as gas refrigerant connecting pipes 6. The refrigeration cycle unit 100a includes multiple first shut-off valve units 9 in place of multiple first shut-off valve units 3 and multiple second shut-off valve units 4.

[0152] (2) Detailed structure

[0153] The first flow interruption valve unit 9 has two first flow dividers 91 and two first flow interruption valves 93.

[0154] One side of the first branch pipe 91 connects the high-pressure gas refrigerant connecting pipe 6a to the gas side of the utilization heat exchanger 11 of the utilization unit 1. The other side of the first branch pipe 91 connects the low-pressure gas refrigerant connecting pipe 6b to the gas side of the utilization heat exchanger 11 of the utilization unit 1.

[0155] The first shut-off valve unit 9 of the refrigeration cycle device 100a has two first branch pipes 91, which are piping that allow the refrigerants flowing between the high-pressure gas refrigerant connecting pipe 6a and the low-pressure gas refrigerant connecting pipe 6b and the utilization unit 1 to flow in parallel with each other.

[0156] The first flow interruption valve 93 is installed in the first diversion pipe 91.

[0157] The liquid refrigerant connecting pipe 5 is connected to the liquid side of the heat exchanger 11 of the utilization unit 1 by piping 92d.

[0158] Figure 5 The illustration shows an example of a refrigeration cycle apparatus 100a comprising two utilization units 1. To distinguish between the two utilization units 1, the suffixes c and d are added to each utilization unit 1 and the equipment it possesses.

[0159] The number of Unit 1s used is not limited to two; it can also be three or more.

[0160] (3) Overall operation (operation when refrigerant leaks)

[0161] Similar to the refrigeration cycle device 100, in the refrigeration cycle device 100a, when the control unit 7 detects a refrigerant leak in any of the utilization units 1 (when the refrigerant sensor 16 detects refrigerant), it closes all the first shut-off valves 93 that block the refrigerant flowing between the utilization unit 1 where the refrigerant leak was detected and the high-pressure gas refrigerant connecting pipe 6a and the low-pressure gas refrigerant connecting pipe 6b.

[0162] (4) Variation Example 2

[0163] In the refrigeration cycle unit 100a, a second shut-off valve unit 4 may be further provided on the piping 92d that connects the liquid refrigerant connecting pipe 5 to the utilization unit 1.

[0164] <Conclusion>

[0165] The embodiments of this disclosure have been described above. However, it should be understood that various changes in form and detail can be made without departing from the spirit and scope of this disclosure as set forth in the claims.

[0166] Symbol Explanation

[0167] 1. Utilize the unit; 2. Heat source unit; 3, 9 First flow interruption valve unit; 4. Second shut-off valve unit; 5. Liquid refrigerant connecting pipe; 6. Gas refrigerant connecting pipe; 7. Control Department; 11. Utilize heat exchangers; 17. Utilize the unit control unit; 21. Compressor; 23. Heat source heat exchanger; 28. Heat source unit control section; 31, 91 First branch pipe; 33, 93 First shut-off valve (shut-off valve); 34. Flow interruption valve control unit; 41 Second branch pipe; 43 Second shut-off valve (shut-off valve); 100, 100a refrigeration cycle unit.

[0168] Existing technical documents

[0169] Patent documents

[0170] Patent document 1: Japanese Patent Application Publication No. 2020-030043.

Claims

1. A refrigeration circulation device (100), characterized in that, include: The utilization unit (1) has a utilization heat exchanger (11). The heat source unit (2) has a compressor (21) and a heat source heat exchanger (23). Gas refrigerant connecting pipe (6), the gas refrigerant connecting pipe is disposed between the compressor and the heat exchanger; as well as The first flow-stopping valve unit (3) is disposed between the gas refrigerant connecting pipe and the utilization unit to block the refrigerant flowing between the gas refrigerant connecting pipe and the utilization unit. The first flow interruption valve unit has: Multiple first diversion pipes (31) allow the refrigerant flowing between the gaseous refrigerant connecting pipe and the utilization unit to flow in parallel with each other; as well as A flow interruption valve (33) is provided on each of the plurality of first diversion pipes.

2. The refrigeration cycle apparatus according to claim 1, characterized in that, Also includes: Liquid refrigerant connecting pipe (5), the liquid refrigerant connecting pipe is disposed between the heat exchanger and the heat source heat exchanger; as well as The second flow-stop valve unit (4) is disposed between the liquid refrigerant connecting pipe and the utilization unit, and blocks the refrigerant flowing between the liquid refrigerant connecting pipe and the utilization unit. The second shut-off valve unit has: Multiple second branch pipes (41) allow the refrigerant flowing between the liquid refrigerant connecting pipe and the utilization unit to flow in parallel with each other; as well as Multiple flow-stopping valves (43) are respectively disposed in the second flow-stopping pipe.

3. The refrigeration cycle apparatus according to claim 2, characterized in that, The refrigeration cycle device also includes a control unit (7) for controlling the flow interruption valve. When a refrigerant leak is detected in the utilization unit, the control unit closes all the shut-off valves that block the flow of refrigerant between the utilization unit where the leak was detected and the gas refrigerant connection pipe or the liquid refrigerant connection pipe.

4. The refrigeration cycle apparatus according to claim 3, characterized in that, The control unit has: The utilization unit control unit (17) is provided in the utilization unit. The heat source unit control unit (28) is provided in the heat source unit; and A flow-stop valve control unit (34) that controls the flow-stop valve. When a refrigerant leak is detected in the utilization unit, the utilization unit control unit sends a first signal to the heat source unit control unit. When the heat source unit control unit receives the first signal, the heat source unit control unit sends a second signal to the flow-stop valve control unit. When the shut-off valve control unit receives the second signal, the shut-off valve control unit closes all the shut-off valves that block the flow of refrigerant between the utilization unit where the refrigerant leak is detected and the gas refrigerant connecting pipe or the liquid refrigerant connecting pipe.

5. The refrigeration cycle apparatus according to claim 3, characterized in that, The control unit has: The utilization unit control unit (17) is provided in the utilization unit; and A flow-stop valve control unit (34) that controls the flow-stop valve. When a refrigerant leak is detected in the utilization unit, the utilization unit control unit sends a third signal to the shut-off valve control unit. When the shut-off valve control unit receives the third signal, the shut-off valve control unit closes all shut-off valves that block the flow of refrigerant between the utilization unit where the refrigerant leak is detected and the gas refrigerant connecting pipe or the liquid refrigerant connecting pipe.

6. The refrigeration cycle apparatus according to claim 1 or 2, characterized in that, The refrigeration cycle device also includes a control unit (7) for controlling the flow interruption valve. When an abnormality is detected in any of the plurality of shut-off valves, the control unit closes all the remaining shut-off valves and then stops the operation of any of the utilization unit and the heat source unit.

7. The refrigeration cycle apparatus according to any one of claims 1 to 6, characterized in that, The rated capacity of the utilization unit is 10 horsepower or more.

8. The refrigeration cycle apparatus according to any one of claims 1 to 7, characterized in that, The shut-off valve is a needle valve.

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