JP6944987B2 - Air conditioning system - Google Patents

Description

The present invention includes a refrigerant circuit configured by connecting an outdoor unit having a compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger via a refrigerant connecting pipe, and includes a liquid side of the outdoor unit. Refrigerant leakage is detected in the liquid refrigerant pipe from the end to the liquid side end of the indoor heat exchanger and the gas refrigerant pipe from the gas side end of the outdoor unit to the gas side end of the indoor heat exchanger. It relates to an air conditioning system provided with a shutoff valve that is closed when it is closed.

Conventionally, there is an air conditioning system including a refrigerant circuit configured by connecting an outdoor unit having a compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger via a refrigerant connecting pipe. In such an air conditioning system, in order to reduce the amount of leakage when a refrigerant leaks, the liquid refrigerant pipe from the liquid side end of the outdoor unit to the liquid side end of the indoor heat exchanger, and the outdoor A shutoff valve that is closed when a refrigerant leak is detected may be provided in the gas refrigerant pipe from the gas side end of the unit to the gas side end of the indoor heat exchanger. Then, in such an air conditioning system, as shown in Patent Document 1 (Japanese Unexamined Patent Publication No. 2013-19621), the shutoff valve is opened and closed during periodic inspections and the like, and the shutoff valve during this open / close operation is operated. Whether or not the shutoff valve is operating normally is determined by the operating noise and vibration.

However, in the conventional method of confirming the operation of the shutoff valve by operating noise or vibration, when the shutoff valve is closed, the closed shutoff valve is actually in the closed state and the desired shutoff performance is achieved. It is not possible to determine whether (the amount of valve leakage in the closed state, etc.) is secured.

An object of the present invention includes a refrigerant circuit configured by connecting an outdoor unit having a compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger via a refrigerant connecting pipe, and includes a liquid refrigerant pipe. In addition, in an air conditioning system provided with a shutoff valve that is closed when a refrigerant leak is detected in the gas refrigerant pipe, it is intended to ensure operation confirmation including the shutoff performance of the shutoff valve.

The air conditioning system according to the first aspect is configured by connecting an outdoor unit having a compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger via a liquid refrigerant connecting pipe and a gas refrigerant connecting pipe. Includes a refrigerant circuit. The air conditioning system includes the liquid refrigerant pipe from the liquid side end of the outdoor unit including the liquid refrigerant connecting pipe to the liquid side end of the indoor heat exchanger, and the gas side of the outdoor unit including the gas refrigerant connecting pipe. A liquid-side shutoff valve and a gas-side shutoff valve that are closed when a refrigerant leak is detected are provided in the gas refrigerant pipe from the end to the gas side end of the indoor heat exchanger. Then, in the air conditioning system, the system control unit that controls the component equipment including the liquid side shutoff valve and the gas side shutoff valve performs the shutoff valve inspection process for checking the operation of the liquid side shutoff valve and the gas side shutoff valve. It has become. Here, the outdoor unit is provided with a suction pressure sensor that detects the pressure of the refrigerant on the suction side of the compressor. Then, in the shutoff valve inspection process, the compressor is operated in a state where the liquid side shutoff valve and the gas side shutoff valve are opened and the outdoor heat exchanger functions as a radiator of the refrigerant, and then the liquid is operated. Based on the change in the pressure value of the refrigerant detected by the suction pressure sensor when one of the side shutoff valve and the gas side shutoff valve is closed, one of the closed liquid side shutoff valve and the gas side shutoff valve is normally closed. It determines whether or not it is operating.

As described above, the compressor is operated in a state where both the liquid side shutoff valve and the gas side shutoff valve are opened and the outdoor heat exchanger functions as a refrigerant radiator (cooling cycle state). When one of the liquid side shutoff valve and the gas side shutoff valve in the open state is closed, the pressure of the refrigerant on the suction side of the compressor suddenly increases if the closed shutoff valve is operating normally. However, if the shutoff valve that has been closed is not operating normally, the pressure of the refrigerant on the suction side of the compressor does not tend to decrease sharply. In this way, when the compressor is operating in the cooling cycle state, if one of the liquid side shutoff valve and the gas side shutoff valve in the open state is closed, the refrigerant detected by the suction pressure sensor at this time Based on the change in the pressure value, it can be determined whether or not one of the closed liquid side shutoff valve and the gas side shutoff valve is operating normally including the shutoff performance.

Thereby, here, it is possible to surely confirm the operation including the shutoff performance of the liquid side shutoff valve and the gas side shutoff valve.

The air conditioning system according to the second aspect is the air adjustment system according to the first aspect. In the shutoff valve inspection process, is one of the closed liquid side shutoff valve and the gas side shutoff valve operating normally? After determining whether or not, the suction pressure sensor when one of the closed liquid side shutoff valve and the gas side shutoff valve is opened and then the other of the liquid side shutoff valve and the gas side shutoff valve is closed is released. Based on the change in the pressure value of the refrigerant to be detected, it is determined whether or not the other of the closed liquid side shutoff valve and the gas side shutoff valve is operating normally.

Here, as described above, after confirming the operation of one of the liquid side shutoff valve and the gas side shutoff valve, both the liquid side shutoff valve and the gas side shutoff valve are opened and the compressor is operated in the cooling cycle state. Return to the operating state, close the other of the liquid side shutoff valve and gas side shutoff valve for which operation has not been confirmed, and based on the change in the pressure value of the refrigerant detected by the suction pressure sensor at this time. Therefore, it is determined whether or not the other of the liquid-side shutoff valve and the gas-side shutoff valve that have been closed is operating normally.

Thereby, here, it is possible to surely confirm the operation including the shutoff performance of the liquid side shutoff valve and the gas side shutoff valve.

The air conditioning system according to the third aspect is configured by connecting an outdoor unit having a compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger via a liquid refrigerant connecting pipe and a gas refrigerant connecting pipe. Includes a refrigerant circuit. The air conditioning system includes the liquid refrigerant pipe from the liquid side end of the outdoor unit including the liquid refrigerant connecting pipe to the liquid side end of the indoor heat exchanger, and the gas side of the outdoor unit including the gas refrigerant connecting pipe. A liquid-side shutoff valve and a gas-side shutoff valve that are closed when a refrigerant leak is detected are provided in the gas refrigerant pipe from the end to the gas side end of the indoor heat exchanger. Then, in the air conditioning system, the system control unit that controls the component equipment including the liquid side shutoff valve and the gas side shutoff valve performs the shutoff valve inspection process for checking the operation of the liquid side shutoff valve and the gas side shutoff valve. It has become. Here, the outdoor unit is provided with a discharge pressure sensor that detects the pressure of the refrigerant on the discharge side of the compressor. Then, in the shutoff valve inspection process, the compressor is operated in a state where the liquid side shutoff valve and the gas side shutoff valve are opened and the outdoor heat exchanger functions as a refrigerant evaporator, and then the liquid is operated. Based on the change in the pressure value of the refrigerant detected by the discharge pressure sensor when one of the side shutoff valve and the gas side shutoff valve is closed, one of the closed liquid side shutoff valve and the gas side shutoff valve is normally closed. It determines whether or not it is operating.

As described above, when the compressor is operated in a state where the outdoor heat exchanger functions as a refrigerant evaporator (heating cycle state), one of the liquid side shutoff valve and the gas side shutoff valve in the open state is used. When the closing operation is performed, if the closed shutoff valve is operating normally, the pressure of the refrigerant on the discharge side of the compressor tends to rise sharply, but the closed shutoff valve is operating normally. Without it, the pressure of the refrigerant on the discharge side of the compressor does not tend to rise sharply. In this way, when the compressor is operating in the heating cycle state, if one of the liquid side shutoff valve and the gas side shutoff valve in the open state is closed, the refrigerant detected by the discharge pressure sensor at this time Based on the change in the pressure value, it can be determined whether or not one of the closed liquid side shutoff valve and the gas side shutoff valve is operating normally including the shutoff performance.

Thereby, here, it is possible to surely confirm the operation including the shutoff performance of the liquid side shutoff valve and the gas side shutoff valve.

The air conditioning system according to the fourth aspect is the air adjustment system according to the third aspect. In the shutoff valve inspection process, is one of the closed liquid side shutoff valve and the gas side shutoff valve operating normally? After determining whether or not, the discharge pressure sensor when one of the closed liquid side shutoff valve and the gas side shutoff valve is opened and then the other of the liquid side shutoff valve and the gas side shutoff valve is closed is released. Based on the change in the pressure value of the refrigerant to be detected, it is determined whether or not the other of the closed liquid side shutoff valve and the gas side shutoff valve is operating normally.

Here, as described above, after confirming the operation of one of the liquid side shutoff valve and the gas side shutoff valve, both the liquid side shutoff valve and the gas side shutoff valve are opened and the compressor is operated in the heating cycle state. Return to the operating state, close the other of the liquid side shutoff valve and gas side shutoff valve for which operation has not been confirmed, and based on the change in the pressure value of the refrigerant detected by the discharge pressure sensor at this time. Therefore, it is determined whether or not the other of the closed liquid side shutoff valve and the gas side shutoff valve is operating normally.

Thereby, here, it is possible to surely confirm the operation including the shutoff performance of the liquid side shutoff valve and the gas side shutoff valve.

The air conditioning system according to the fifth aspect is the air conditioning system according to any one of the first to fourth aspects, in which there are a plurality of indoor units, and a liquid side shutoff valve and a gas side shutoff valve are provided in each indoor unit. It is provided in the liquid refrigerant pipe and the gas refrigerant pipe so as to correspond to each other. Here, the system control unit shuts off one of the plurality of indoor units while performing a shutoff valve inspection process for the corresponding liquid side shutoff valve and gas side shutoff valve for one of the plurality of indoor units. For indoor units that are not subject to valve inspection processing, stop operation.

In an air conditioning system having multiple indoor units, a liquid-side shutoff valve and a gas-side shutoff valve corresponding to each indoor unit are provided, and the shutoff valve inspection process is performed simultaneously for multiple liquid-side shutoff valves and gas-side shutoff valves. Then, the pressure value changes due to the closing operation of multiple liquid side shutoff valves and gas side shutoff valves at the same time, and which shutoff valve is operating normally (or which shutoff valve is operating normally). Is not possible to distinguish.

Therefore, here, as described above, for one of the plurality of indoor units, the corresponding liquid side shutoff valve and gas side shutoff valve are inspected for the shutoff valve, and the plurality of indoor units are subjected to the shutoff valve inspection process. Of these, indoor units that are not subject to shutoff valve inspection processing are stopped from operation. Therefore, it is possible to determine whether or not the pressure value is changed due to the closing operation of the shutoff valve after distinguishing it from the shutoff valve that is the target of the shutoff valve inspection process. ..

As a result, here, even in a configuration in which a liquid-side shutoff valve and a gas-side shutoff valve corresponding to each of the plurality of indoor units are provided, the operation of the plurality of shutoff valves including the shutoff performance is sequentially checked. , It is possible to determine whether or not each shutoff valve is operating normally.

The air conditioning system according to the sixth aspect is the air conditioning system according to any one of the first to fifth aspects, in which a refrigerant leakage detection device for detecting the presence or absence of refrigerant leakage is connected to the system control unit. There is. Here, in the shutoff valve inspection process, the system control unit simulates inputting a signal indicating the presence or absence of refrigerant leakage output from the refrigerant leak detection device to the system control unit to shut off the liquid side shutoff valve and the gas side. It has a simulated input permission unit for permitting the opening and closing operation of the valve.

As described above, when the shutoff valve inspection process is performed by simulating the opening / closing operation of the liquid side shutoff valve and the gas side shutoff valve by inputting a signal indicating the presence or absence of refrigerant leakage output from the refrigerant leak detection device. The system control unit needs to be able to distinguish whether the signal output from the refrigerant leakage detection device is a simulated input or a signal indicating the presence or absence of an actual refrigerant leakage. This is because when a signal indicating that a refrigerant is leaking is input from the refrigerant leakage detection device, the liquid side shutoff valve and the gas side shutoff valve are closed, but at this time, the system control unit is really It is judged that the refrigerant is leaking, and the liquid side shutoff valve and gas side shutoff valve are closed, and the operation required for shutoff valve inspection processing such as operating the compressor in the cooling cycle state. This is because it becomes impossible to do.

Therefore, here, as described above, in the shutoff valve inspection process, the liquid side shutoff valve and the gas are simulated by inputting a signal indicating the presence or absence of the refrigerant leak output from the refrigerant leak detection device to the system control unit in a simulated manner. The system control unit is provided with a simulated input permission unit for permitting the opening / closing operation of the side shutoff valve. For this reason, the system control unit is really able to control the refrigerant by allowing the shutoff valve inspection process to be performed by inputting a signal indicating the presence or absence of refrigerant leakage output from the refrigerant leakage detection device using the simulated input permission unit. It is possible to prevent it from being determined that a leak has occurred, and to perform operations necessary for shut-off valve inspection processing such as operating the compressor in a cooling cycle state or a heating cycle state.

As a result, here, the shutoff valve inspection process can be performed by simulating a signal indicating the presence or absence of refrigerant leakage output from the refrigerant leakage detection device to the system control unit. It is possible to confirm the operation of the liquid side shutoff valve and the gas side shutoff valve as well as confirm the communication connection between the refrigerant leak detection device and the refrigerant leak detection device.

As described above, according to the present invention, a refrigerant configured by connecting an outdoor unit having a compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger via a refrigerant connecting pipe. In an air conditioning system that includes a circuit and is equipped with a shutoff valve that closes when a refrigerant leak is detected in the liquid refrigerant pipe and gas refrigerant pipe, ensure operation confirmation including the shutoff performance of the shutoff valve. Can be done.

It is a schematic block diagram of the air conditioning system which concerns on 1st Embodiment of this invention. It is a control block diagram of the air conditioning system which concerns on 1st Embodiment of this invention (the outdoor control part and the indoor control part are shown in detail). It is a control block diagram (the shutoff valve control part and the refrigerant leakage detection part are shown in detail) of the air conditioning system which concerns on 1st Embodiment of this invention. It is a flowchart of the shutoff valve inspection process (process by operation of a compressor in a cooling cycle state) in the air conditioning system which concerns on 1st Embodiment of this invention. It is a flowchart of the shutoff valve inspection process (process by operation of a compressor in a heating cycle state) in the air conditioning system which concerns on 1st Embodiment of this invention. It is a control block diagram (the outdoor control part and the indoor control part are shown in detail) of the air-conditioning system which concerns on the modification of 1st Embodiment of this invention. It is a schematic block diagram of the air conditioning system which concerns on 2nd Embodiment of this invention. It is a control block diagram of the air conditioning system which concerns on 2nd Embodiment of this invention (the outdoor control part and the indoor control part are shown in detail). It is a control block diagram (the shutoff valve control part and the refrigerant leakage detection part are shown in detail) of the air conditioning system which concerns on 2nd Embodiment of this invention. It is a flowchart of the shutoff valve inspection process (process by operation of a compressor in a cooling cycle state) in the air conditioning system which concerns on 2nd Embodiment of this invention. It is a flowchart of the shutoff valve inspection process (process by operation of a compressor in a heating cycle state) in the air conditioning system which concerns on 2nd Embodiment of this invention. It is a control block diagram (the outdoor control part and the indoor control part are shown in detail) of the air-conditioning system which concerns on the modification 1 of the 2nd Embodiment of this invention.

Hereinafter, embodiments of the air conditioning system according to the present invention will be described with reference to the drawings. The specific configuration of the embodiment of the air conditioning system according to the present invention is not limited to the following embodiments and modifications thereof, and can be changed without departing from the gist of the invention.

<First Embodiment>
(1) Configuration-Overall-
FIG. 1 is a schematic configuration diagram of an air conditioning system 1 according to a first embodiment of the present invention.

The air conditioning system 1 is a system that cools and heats a room such as a building by a vapor compression refrigeration cycle. The air conditioning system 1 mainly includes a vapor compression type refrigerant circuit 10 configured by connecting the outdoor unit 2 and the indoor unit 4 via a liquid refrigerant connecting pipe 5 and a gas refrigerant connecting pipe 6. The outdoor unit 2 is installed outdoors and mainly has a compressor 21 and an outdoor heat exchanger 24. The indoor unit 4 is installed indoors and has an indoor heat exchanger 42. The refrigerant circuit 10 is filled with a slightly flammable refrigerant such as R32 or a highly flammable refrigerant such as R290 as the refrigerant.

Further, the air conditioning system 1 includes a liquid refrigerant pipe 50 from the liquid side end of the outdoor unit 2 including the liquid refrigerant connecting pipe 5 to the liquid side end of the indoor heat exchanger 42, and a gas refrigerant connecting pipe 6. The liquid side shutoff valve 7 and the gas that are closed when a refrigerant leak is detected in the gas refrigerant pipe 60 from the gas side end of the outdoor unit 2 including the above to the gas side end of the indoor heat exchanger 42. A side shutoff valve 8 is provided. Here, a liquid-side closing valve 26 and a gas-side closing valve 27 that are manually opened and closed are provided at the liquid-side end and the gas-side end of the outdoor unit 2. Further, the indoor unit 4 connects the indoor liquid refrigerant pipe 43 that connects the liquid refrigerant connecting pipe 5 and the liquid side end of the indoor heat exchanger 42, and the gas refrigerant connecting pipe 6 and the gas side end of the indoor heat exchanger 42. It has an indoor gas refrigerant pipe 44 to be connected. Therefore, the liquid refrigerant pipe 50 means a refrigerant pipe composed of the liquid refrigerant connecting pipe 5 and the indoor liquid refrigerant pipe 43, and the gas refrigerant pipe 60 is a refrigerant composed of the gas refrigerant connecting pipe 6 and the indoor gas refrigerant pipe 44. It means a tube. The liquid-side shutoff valve 7 and the gas-side shutoff valve 8 are valves that are closed when a refrigerant leak is detected. Here, the liquid-side shutoff valve 7 is a liquid refrigerant communication pipe 5 of the liquid refrigerant pipes 50. The gas side shutoff valve 8 is provided in the portion of the gas refrigerant pipe 60 near the indoor unit 4 of the gas refrigerant connecting pipe 6. Further, unlike the manual valves such as the liquid side shutoff valve 26 and the gas side shutoff valve 27, the liquid side shutoff valve 7 and the gas side shutoff valve 8 are signals indicating the presence or absence of leakage of the refrigerant from the outside and an on-off command. It consists of an automatic valve that opens and closes in response to a signal or the like. Here, in order to detect the presence or absence of refrigerant leakage, a refrigerant leakage detection device 9 is provided in the room.

The air conditioning system 1 is provided with a system control unit 11 that controls constituent devices including a liquid side shutoff valve 7 and a gas side shutoff valve 8. The system control unit 11 includes an outdoor control unit 20 that controls the components of the outdoor unit 2, an indoor control unit 40 that controls the components of the indoor unit 4, and a liquid side shutoff control unit 70 that controls the liquid side shutoff valve 7. And the gas side shutoff control unit 80 that controls the gas side shutoff valve 8 are connected via a communication line. The outdoor control unit 20 is provided in the outdoor unit 2. The indoor control unit 40 is provided in the indoor unit 4. The liquid side shutoff control unit 70 is provided on the liquid side shutoff valve 7, and the gas side shutoff control unit 80 is provided on the gas side shutoff valve 8. Further, the refrigerant leakage detection control unit 90 that controls the refrigerant leakage detection device 9 is also connected to the system control unit 11. The refrigerant leakage detection control unit 90 is provided in the refrigerant leakage detection device 9. Here, wired communication in which the control units 20, 40, 70, 80, and 90 are connected via a communication line is adopted, but the present invention is not limited to this, and other methods such as wireless communication are adopted. It may be in a communication format.

-Outdoor unit-
As described above, the outdoor unit 2 is connected to the indoor unit 4 via the refrigerant connecting pipes 5 and 6, and constitutes a part of the refrigerant circuit 10.

The outdoor unit 2 mainly includes a compressor 21, a switching mechanism 23, an outdoor heat exchanger 24, an outdoor expansion valve 25, a liquid side closing valve 26, and a gas side closing valve 27.

The compressor 21 is a mechanism for compressing the refrigerant, and here, a positive displacement compression element (not shown) such as a rotary type or a scroll type housed in a casing (not shown) is also contained in the casing. A sealed compressor driven by a contained compressor motor 22 is employed.

The switching mechanism 23 is a four-way switching valve capable of switching between a cooling cycle state in which the outdoor heat exchanger 24 functions as a refrigerant radiator and a heating cycle state in which the outdoor heat exchanger 24 functions as a refrigerant evaporator. Here, the cooling cycle state is a switching state in which the discharge side of the compressor 21 and the gas side end of the outdoor heat exchanger 24 are communicated with each other, and the gas refrigerant connecting pipe 6 and the suction side of the compressor 21 are communicated with each other. (See the solid line of the switching mechanism 23 in FIG. 1). The heating cycle state is a switching state in which the discharge side of the compressor 21 and the gas-refrigerant connecting pipe 6 are communicated with each other, and the gas side end of the outdoor heat exchanger 24 and the suction side of the compressor 21 are communicated with each other (FIG. 1). See the dashed line of the switching mechanism 23). The switching mechanism 23 is not limited to the four-way switching valve, and is configured to have a function of switching the direction of the refrigerant flow in the same manner as described above by, for example, combining a plurality of solenoid valves. There may be.

The outdoor heat exchanger 24 is a heat exchanger that functions as a radiator or evaporator of the refrigerant by exchanging heat between the refrigerant and the outdoor air. The outdoor air that exchanges heat with the refrigerant in the outdoor heat exchanger 24 is supplied by the outdoor fan 28 driven by the outdoor fan motor 29.

The outdoor expansion valve 25 is a mechanism for reducing the pressure of the refrigerant, and here, an electric expansion valve capable of controlling the opening degree is adopted.

The liquid-side closing valve 26 and the gas-side closing valve 27 are valves that are manually opened and closed at the liquid-side end and the gas-side end of the outdoor unit 2 as described above.

Further, the outdoor unit 2 is provided with various sensors. Specifically, around the compressor 21 of the outdoor unit 2, a suction pressure sensor 35 that detects the pressure Ps of the refrigerant on the suction side of the compressor 21 and a pressure Pd of the refrigerant on the discharge side of the compressor 21 are detected. A discharge pressure sensor 36 is provided.

-Indoor unit-
As described above, the indoor unit 4 is connected to the outdoor unit 2 via the refrigerant connecting pipes 5 and 6, and constitutes a part of the refrigerant circuit 10.

The indoor unit 4 mainly has an indoor heat exchanger 42.

The indoor heat exchanger 42 is a heat exchanger that functions as a refrigerant evaporator or radiator by exchanging heat between the refrigerant and the indoor air. The indoor air that exchanges heat with the refrigerant in the indoor heat exchanger 42 is supplied by the indoor fan 45 driven by the indoor fan motor 46.

Further, the indoor unit 4 is provided with various sensors. Specifically, the indoor unit 4 includes an indoor heat exchange liquid side sensor 47 that detects the temperature Trl of the refrigerant at the liquid side end of the indoor heat exchanger 42, and a temperature Tra of the indoor air sucked into the indoor unit 4. The indoor air sensor 48 for detecting the above is provided.

-System control unit and refrigerant leak detection control unit-
FIG. 2 is a control block diagram of the air conditioning system 1 (outdoor control unit 20 and indoor control unit 40 are shown in detail), and FIG. 3 is a control block diagram of the air conditioning system 1 (shutoff valve control units 70, 80). And the refrigerant leakage detection unit 90 is shown in detail).

The outdoor control unit 20 controls the operation of the outdoor unit 2 and constitutes a part of the system control unit 11. The outdoor control unit 20 mainly includes an outdoor CPU 121, an outdoor communication unit 122, an outdoor storage unit 123, an outdoor operation unit 124, and an outdoor display unit 125. The outdoor CPU 121 is connected to the outdoor communication unit 122, the outdoor storage unit 123, the outdoor operation unit 124, and the outdoor display unit 125. The outdoor communication unit 122 communicates control data and the like between the indoor control units 40. The outdoor storage unit 123 stores control data and the like. The outdoor operation unit 124 inputs a control command or the like. The outdoor display unit 125 displays (outputs) the operating status and the like. Then, the outdoor CPU 121 accepts inputs such as control commands and communicates control data via the outdoor communication unit 122 and the outdoor operation unit 124, reads and writes control data and the like to the outdoor storage unit 123, and displays the outdoor display unit. While displaying the operation status and the like on 125, the state quantity is detected by various sensors 35 and 36 and the operation control of the constituent devices 21, 23, 25, 28 and the like of the outdoor unit 2 is performed.

The indoor control unit 40 controls the operation of the indoor unit 4 and constitutes a part of the system control unit 11. The indoor control unit 40 mainly includes an indoor CPU 141, an indoor communication unit 142, an indoor storage unit 143, an indoor operation unit 144, and an indoor display unit 145. The indoor CPU 141 is connected to the indoor communication unit 142, the indoor storage unit 143, the indoor operation unit 144, and the indoor display unit 145. The indoor communication unit 142 communicates control data and the like with the outdoor control unit 20, the liquid side cutoff control unit 70, the gas side cutoff control unit 80, and the refrigerant leakage detection control unit 90. The indoor storage unit 143 stores control data and the like. The indoor operation unit 144 inputs a control command or the like. The indoor display unit 145 displays (outputs) the operating status and the like. Then, the indoor CPU 141 accepts inputs such as control commands and communicates control data via the indoor communication unit 142 and the indoor operation unit 144, reads and writes control data and the like to the indoor storage unit 143, and displays the indoor display unit. While displaying the operation status and the like on the 145, the state quantity is detected by various sensors 47 and 48 and the operation control of the constituent devices 45 and the like of the indoor unit 4 is performed. If a remote controller is provided corresponding to the indoor unit 4, the remote controller also constitutes the indoor control unit 40.

The liquid-side shutoff control unit 70 controls the opening / closing of the liquid-side shutoff valve 7, and constitutes a part of the system control unit 11. The liquid-side cutoff control unit 70 mainly includes a liquid-side cutoff CPU 171, a liquid-side cutoff communication unit 172, and a liquid-side cutoff storage unit 173. The liquid-side shutoff CPU 171 is connected to the liquid-side shutoff communication unit 172 and the liquid-side shutoff storage unit 173. The liquid side shutoff communication unit 172 communicates control data and the like between the indoor control units 40. The liquid side shutoff storage unit 173 stores control data and the like. Then, the liquid-side shutoff CPU 171 communicates control data and the like via the liquid-side shutoff communication unit 172, reads and writes control data and the like to the liquid-side shutoff storage unit 173, and controls opening and closing of the liquid-side shutoff valve 7. ..

The gas side shutoff control unit 80 controls the opening / closing of the gas side shutoff valve 8 and constitutes a part of the system control unit 11. The gas side cutoff control unit 80 mainly includes a gas side cutoff CPU 181, a gas side cutoff communication unit 182, and a gas side cutoff storage unit 183. The gas side cutoff CPU 181 is connected to the gas side cutoff communication unit 182 and the gas side cutoff storage unit 183. The gas side cutoff communication unit 182 communicates control data and the like between the indoor control units 40. The gas side cutoff storage unit 183 stores control data and the like. Then, the gas side shutoff CPU 181 communicates control data and the like via the gas side shutoff communication unit 182, reads and writes control data and the like to the gas side shutoff storage unit 183, and controls opening and closing of the gas side shutoff valve 8. ..

The refrigerant leakage detection control unit 90 performs detection control of the refrigerant leakage detection device 9, and is connected to the system control unit 11. The refrigerant leakage detection control unit 90 mainly includes a detection CPU 191, a detection communication unit 192, and a detection storage unit 193. The detection CPU 191 is connected to the detection communication unit 192 and the detection storage unit 193. The detection communication unit 192 communicates control data and the like between the indoor control units 40. The detection storage unit 193 stores control data and the like. Then, the detection CPU 191 communicates the control data and the like via the detection and communication unit 192, reads and writes the control data and the like to the detection and storage unit 193, and performs the detection control of the refrigerant leakage detection device 9.

Further, here, the indoor CPU 141 of the indoor control unit 40 has a normal operation processing unit 146 for executing normal operation processing including cooling operation and heating operation, and a shutoff valve 7 that is performed when a leakage of refrigerant is detected. Refrigerant leak processing unit 147 for executing refrigerant leakage processing including closing of, and shutoff valve inspection processing for executing shutoff valve inspection processing including operation check of shutoff valves 7 and 8 performed for periodic inspections and the like. A section 148 and a section 148 are provided.

(2) Operation-Normal operation-
In the air conditioning system 1, a cooling operation and a heating operation are performed as normal operations.

First, the cooling operation will be described. When the system control unit 11 is instructed to perform the cooling operation via the indoor operation unit 144 or the like of the indoor control unit 40, the normal operation processing unit 146 of the indoor CPU 141 executes the following cooling operation.

Specifically, the switching mechanism 23 is switched to the cooling cycle state (the state shown by the solid line of the switching mechanism 23 in FIG. 1), and the compressor 21, the outdoor fan 28, and the indoor fan 45 are activated. Further, here, since the refrigerant has not leaked (that is, the refrigerant leak has not been detected by the refrigerant leak detecting device 9), the liquid side shutoff valve 7 and the gas side shutoff valve 8 are both opened. It is in a state. Then, the refrigerant discharged from the compressor 21 is sent to the outdoor heat exchanger 24 via the switching mechanism 23. The refrigerant sent to the outdoor heat exchanger 24 is condensed by being cooled by exchanging heat with the outdoor air supplied by the outdoor fan 28 in the outdoor heat exchanger 24 that functions as a radiator of the refrigerant. This refrigerant is sent to the outdoor expansion valve 25. The refrigerant sent to the outdoor expansion valve 25 is depressurized by the outdoor expansion valve 25 and passes through the liquid side closing valve 26 and the liquid refrigerant pipe 50 (liquid refrigerant connecting pipe 5, liquid side shutoff valve 7 and indoor liquid refrigerant pipe 43). Then, it is sent to the indoor heat exchanger 42. The refrigerant sent to the indoor heat exchanger 42 evaporates by being heated by exchanging heat with the indoor air supplied from the room by the indoor fan 45 in the indoor heat exchanger 42 that functions as a refrigerant evaporator. .. This refrigerant is sucked into the compressor 21 via the gas refrigerant pipe 60 (indoor gas refrigerant pipe 44, gas refrigerant connecting pipe 6, gas side shutoff valve 8), gas side closing valve 27, and switching mechanism 23. On the other hand, the indoor air cooled by the indoor heat exchanger 42 is sent into the room, thereby cooling the room.

Next, the heating operation will be described. When the system control unit 11 is instructed to perform the heating operation via the indoor operation unit 144 or the like of the indoor control unit 40, the normal operation processing unit 146 of the indoor CPU 141 executes the following heating operation.

Specifically, the switching mechanism 23 is switched to the heating cycle state (the state shown by the broken line of the switching mechanism 23 in FIG. 1), and the compressor 21, the outdoor fan 28, and the indoor fan 45 are activated. Further, here, since the refrigerant has not leaked (that is, the refrigerant leak has not been detected by the refrigerant leak detecting device 9), the liquid side shutoff valve 7 and the gas side shutoff valve 8 are both opened. It is in a state. Then, the refrigerant discharged from the compressor 21 passes through the switching mechanism 23, the gas side closing valve 27, and the gas refrigerant pipe 60 (gas refrigerant connecting pipe 6, gas side shutoff valve 8, indoor gas refrigerant pipe 44). It is sent to the indoor heat exchanger 42. The refrigerant sent to the indoor heat exchanger 42 is condensed by being cooled by exchanging heat with the indoor air supplied from the room by the indoor fan 45 in the indoor heat exchanger 42 that functions as a radiator of the refrigerant. .. This refrigerant is sent to the outdoor expansion valve 25 via the liquid refrigerant pipe 50 (indoor liquid refrigerant pipe 43, liquid refrigerant connecting pipe 5 and liquid side shutoff valve 7) and the liquid side closing valve 26. On the other hand, the indoor air heated by the indoor heat exchanger 42 is sent into the room, thereby heating the room. The refrigerant sent to the outdoor expansion valve 25 is depressurized by the outdoor expansion valve 25 and sent to the outdoor heat exchanger 24. The refrigerant sent to the outdoor heat exchanger 24 evaporates by being heated by exchanging heat with the outdoor air supplied by the outdoor fan 28 in the outdoor heat exchanger 24 that functions as a refrigerant evaporator. This refrigerant is sucked into the compressor 21 via the switching mechanism 23.

-Refrigerant leakage treatment-
When a refrigerant leak is detected in the above normal operation, it is necessary to close the liquid side shutoff valve 7 and the gas side shutoff valve 8 in order to reduce the amount of the refrigerant leaked into the room. Therefore, when a signal indicating that the refrigerant is leaking, which is output from the refrigerant leakage detection device 9 (refrigerant leakage detection control unit 90), is input to the system control unit 11 (indoor control unit 40), the indoor CPU 141 The following refrigerant leakage treatment is executed by the refrigerant leakage treatment unit 147 of the above.

Specifically, the liquid side shutoff valve 7 and the gas side shutoff valve 8 are closed to eliminate the flow of the refrigerant from the outdoor unit 2 to the indoor unit 4. The compressor 21 also stops. As a result, the amount of refrigerant leaked into the room can be reduced, and here, the occurrence of ignition accidents in the room can be suppressed by preventing the flammable refrigerant from exceeding the flammable concentration.

− Shut-off valve inspection process −
Refrigerant leakage treatment using the above shutoff valves 7 and 8 is an effective means for preventing accidents due to refrigerant leakage, but in order to ensure that the refrigerant leakage treatment is performed, the refrigerant It is necessary that the liquid side shutoff valve 7 and the gas side shutoff valve 8 are actually closed by the closing operation when the leakage is detected, and the desired shutoff performance is ensured. On the other hand, at the time of periodic inspection, etc., it is conceivable to check the operation of the liquid side shutoff valve 7 and the gas side shutoff valve 8, but the operation noise of the shutoff valve during the opening / closing operation as in Patent Document 1. In the method of checking the operation by vibration or vibration, when the shutoff valve is closed, the shutoff valve that has been closed is actually in the closed state, and the desired shutoff performance (valve leakage amount in the closed state, etc.) is obtained. There is a problem that it is not possible to determine whether or not it is secured, and it is not possible to check the operation including the shutoff performance of the shutoff valve.

Therefore, here, as a shutoff valve inspection process for checking the operation of the liquid side shutoff valve 7 and the gas side shutoff valve 8, the compressor 21 is operated with the liquid side shutoff valve 7 and the gas side shutoff valve 8 open. After the operation, whether or not the closed shutoff valve is operating normally is based on the change in the pressure value of the refrigerant when one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed. I am trying to judge. To explain in a little more detail, when the compressor 21 is being operated with both the liquid side shutoff valve 7 and the gas side shutoff valve 8 being opened, the liquid side shutoff valve 7 and the gas side in the open state are opened. When one of the shutoff valves 8 is closed, if the closed shutoff valve is operating normally, the pressure of the refrigerant on the suction side and the discharge side of the compressor 21 changes abruptly, but the shutoff is closed. If the valve is not operating normally, the pressure of the refrigerant on the suction side and the discharge side of the compressor 21 does not tend to change abruptly. In this way, if one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 in the open state is closed while the compressor 21 is being operated, based on the change in the pressure value of the refrigerant at this time. It is possible to determine whether or not one of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 that have been closed is operating normally, including the shutoff performance. Therefore, the shutoff valve inspection process described here is based on such a technical idea.

Next, the shutoff valve inspection process will be described in detail with reference to FIGS. 1 to 5. Here, FIG. 4 is a flowchart of a shutoff valve inspection process involving the operation of the compressor 21 in the cooling cycle state, and FIG. 5 is a flowchart of the shutoff valve inspection process involving the operation of the compressor 21 in the heating cycle state. Is. When the system control unit 11 is instructed to perform a shutoff valve inspection process via the indoor operation unit 144 of the indoor control unit 40, the outdoor operation unit 124 of the outdoor control unit 20, etc., the shutoff valve inspection process unit 148 of the indoor control unit 40 is instructed. The following shutoff valve inspection process is executed. Further, here, it is possible to select and perform either the shutoff valve inspection process by operating the compressor 21 in the cooling cycle state or the shutoff valve inspection process by operating the compressor 21 in the heating cycle state. It has become.

First, a shutoff valve inspection process that involves the operation of the compressor 21 in the cooling cycle state will be described.

In step ST1, the shutoff valve inspection processing unit 148 is in a state in which the liquid side shutoff valve 7 and the gas side shutoff valve 8 are opened, and the outdoor heat exchanger 24 functions as a radiator of the refrigerant (cooling cycle state). ), Then, in step ST2, one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed. That is, the compressor 21 is operated by performing the same operation as the cooling operation in which the refrigerant circulates in the refrigerant circuit 10 in the cooling cycle state, and then closing one of the liquid side shutoff valve 7 and the gas side shutoff valve 8. It tries to stop the circulation of the refrigerant while continuing the operation.

Here, when the compressor 21 is being operated in the cooling cycle state with both the liquid side shutoff valve 7 and the gas side shutoff valve 8 being opened, the liquid side shutoff valve 7 and the open state shutoff valve 7 and When one of the gas side shutoff valves 8 is closed, if the closed shutoff valve is operating normally, the refrigerant pressure Ps (suction pressure Ps) on the suction side of the compressor 21 tends to decrease sharply. As shown, if the shutoff valve that has been closed is not operating normally, the suction pressure Ps does not tend to drop sharply. As described above, in steps ST1 and ST2, as described above, when the compressor 21 is being operated in the cooling cycle state, one of the open liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed. By doing so, as long as the shutoff valve that has been closed is operating normally, the suction pressure Ps tends to drop sharply.

Then, the shutoff valve inspection processing unit 148 detects the refrigerant detected by the suction pressure sensor 35 when one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed in step ST3 after the processing of steps ST1 and ST2. Based on the change in the pressure value (suction pressure Ps), it is determined whether or not one of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally. Here, when the suction pressure Ps tends to decrease sharply due to the closing operation of one of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 in step ST2, the closed-operated liquid-side shutoff valve 7 and It is determined that one of the gas side shutoff valves 8 is operating normally. Here, whether or not the suction pressure Ps tends to decrease sharply depends on, for example, the decrease width ΔPs of the suction pressure Ps before and after closing one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 in step ST2. Can be determined by whether or not is equal to or greater than a predetermined reduction width ΔPss.

Then, in step ST3, when it is determined that one of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 that have been closed by satisfying the above-mentioned suction pressure Ps condition is operating normally, the step is taken. In ST4, the fact that one of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally is notified through the display on the indoor display unit 145 of the indoor control unit 40, and the above suction pressure. If it is determined that one of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 does not satisfy the Ps condition and is not operating normally, the closed liquid side shutoff is performed in step ST5. The fact that one of the valve 7 and the gas side shutoff valve 8 is not operating normally is notified through a display on the indoor display unit 145 of the indoor control unit 40 or the like.

In this way, by the processing of steps ST1 to ST5, it is possible to reliably confirm the operation including the shutoff performance of one of the liquid side shutoff valve 7 and the gas side shutoff valve 8.

Then, the shutoff valve inspection processing unit 148 determines whether or not one of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally (that is, after the processing of steps ST1 to ST5). In step ST6, one of the closed liquid side shutoff valve 7 and the gas side shutoff valve is opened, and then in step ST7, the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed. .. That is, after confirming the operation of one of the liquid side shutoff valve 7 and the gas side shutoff valve 8, the compressor 21 is operated in the cooling cycle state with both the liquid side shutoff valve 7 and the gas side shutoff valve 8 open. By returning to the state in which the compressor 21 is being operated and closing the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 for which operation has not been confirmed, the circulation of the refrigerant is stopped again while continuing the operation of the compressor 21. I try to do it.

Then, after the processing of steps ST6 and ST7, the shutoff valve inspection processing unit 148 detects the refrigerant detected by the suction pressure sensor 35 when the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed in step ST8. Based on the change in the pressure value (suction pressure Ps), it is determined whether or not the other of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally. Here, when the suction pressure Ps tends to decrease sharply due to the closing operation of the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 in step ST7, the closing operation is performed in the same manner as in step ST3. It is determined that the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally.

Then, in step ST8, when it is determined that the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 which are closed by satisfying the above-mentioned suction pressure Ps condition are operating normally, the step is taken. In ST9, the fact that the other of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 that have been closed is operating normally is notified through the display on the indoor display unit 145 of the indoor control unit 40, and the above suction pressure. If it is determined that the other of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 that are closed without satisfying the Ps condition is not operating normally, the liquid-side shutoff that is closed is shut off in step ST10. The fact that the other of the valve 7 and the gas side shutoff valve 8 is not operating normally is notified through a display on the indoor display unit 145 of the indoor control unit 40 or the like.

In this way, by the processing of steps ST6 to ST10, it is possible to reliably confirm the operation including the shutoff performance of the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8. That is, by the processing of steps ST1 to ST10, it is possible to reliably confirm the operation including the shutoff performance of the liquid side shutoff valve 7 and the gas side shutoff valve 8.

Next, a shutoff valve inspection process that involves the operation of the compressor 21 in the heating cycle state will be described.

The shutoff valve inspection processing unit 148 is in a state in which the liquid side shutoff valve 7 and the gas side shutoff valve 8 are opened in step ST11, and the outdoor heat exchanger 24 functions as a refrigerant evaporator (heating cycle state). ), Then, in step ST12, one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed. That is, the compressor 21 is operated by performing the same operation as the heating operation in which the refrigerant circulates in the refrigerant circuit 10 in the heating cycle state, and then closing one of the liquid side shutoff valve 7 and the gas side shutoff valve 8. It tries to stop the circulation of the refrigerant while continuing the operation.

Here, when the compressor 21 is being operated in the heating cycle state with both the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 being opened, the liquid-side shutoff valve 7 and the gas-side shutoff valve 7 in the open state and the compressor 21 are operated. When one of the gas side shutoff valves 8 is closed, if the closed shutoff valve is operating normally, the refrigerant pressure Pd (discharge pressure Pd) on the discharge side of the compressor 21 tends to rise sharply. As shown, if the shutoff valve that has been closed is not operating normally, the discharge pressure Pd does not tend to rise sharply. As described above, in steps ST11 and ST12, as described above, when the compressor 21 is being operated in the heating cycle state, one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 in the open state is closed. By doing so, as long as the shutoff valve that has been closed is operating normally, a state in which the discharge pressure Pd tends to rise sharply is created.

Then, after the processing of steps ST11 and ST12, the shutoff valve inspection processing unit 148 detects the refrigerant detected by the discharge pressure sensor 36 when one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed in step ST13. Based on the change in the pressure value (discharge pressure Pd), it is determined whether or not one of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally. Here, when the discharge pressure Pd tends to rise sharply due to the closing operation of one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 in step ST12, the closed liquid side shutoff valve 7 and the liquid side shutoff valve 7 and It is determined that one of the gas side shutoff valves 8 is operating normally. Here, whether or not the discharge pressure Pd tends to increase sharply is determined by, for example, the increase width ΔPd of the discharge pressure Pd before and after closing one of the liquid side shutoff valve 7 and the gas side shutoff valve 8 in step ST12. Can be determined by whether or not is equal to or greater than a predetermined rise width ΔPds.

Then, in step ST13, when it is determined that one of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 that have been closed by satisfying the above-mentioned discharge pressure Pd condition is operating normally, the step is taken. In ST14, the fact that one of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally is notified through the display on the indoor display unit 145 of the indoor control unit 40, etc., and the above discharge pressure If it is determined that one of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 does not satisfy the conditions of Pd and is not operating normally, the closed liquid side shutoff is performed in step ST15. The fact that one of the valve 7 and the gas side shutoff valve 8 is not operating normally is notified through a display on the indoor display unit 145 of the indoor control unit 40 or the like.

In this way, by the processing of steps ST11 to ST15, it is possible to reliably confirm the operation including the shutoff performance of one of the liquid side shutoff valve 7 and the gas side shutoff valve 8.

Then, the shutoff valve inspection processing unit 148 determines whether or not one of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally (that is, after the processing of steps ST11 to ST15). In step ST16, one of the closed liquid side shutoff valve 7 and the gas side shutoff valve is opened, and then in step ST17, the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed. .. That is, after confirming the operation of one of the liquid side shutoff valve 7 and the gas side shutoff valve 8, the compressor 21 is operated in the heating cycle state with both the liquid side shutoff valve 7 and the gas side shutoff valve 8 open. By returning to the state in which the compressor 21 is being operated and closing the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 for which operation has not been confirmed, the circulation of the refrigerant is stopped again while continuing the operation of the compressor 21. I try to do it.

Then, after the processing of steps ST16 and ST17, the shutoff valve inspection processing unit 148 detects the refrigerant detected by the discharge pressure sensor 36 when the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is closed in step ST18. Based on the change in the pressure value (discharge pressure Pd), it is determined whether or not the other of the closed liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally. Here, when the discharge pressure Pd tends to rise sharply due to the closing operation of the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 in step ST17, the closing operation is performed in the same manner as in step ST13. It is determined that the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8 is operating normally.

Then, in step ST18, when it is determined that the other of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 that have been closed by satisfying the above-mentioned discharge pressure Pd condition is operating normally, the step is taken. In ST19, the fact that the other of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 that have been closed is operating normally is notified through the display on the indoor display unit 145 of the indoor control unit 40, and the above discharge pressure. If it is determined that the other of the liquid-side shutoff valve 7 and the gas-side shutoff valve 8 that are closed without satisfying the Pd condition is not operating normally, the liquid-side shutoff that is closed is shut off in step ST20. The fact that the other of the valve 7 and the gas side shutoff valve 8 is not operating normally is notified through a display on the indoor display unit 145 of the indoor control unit 40 or the like.

In this way, by the processing of steps ST16 to ST20, it is possible to reliably confirm the operation including the shutoff performance of the other of the liquid side shutoff valve 7 and the gas side shutoff valve 8. That is, by the processing of steps ST11 to ST20, it is possible to reliably confirm the operation including the shutoff performance of the liquid side shutoff valve 7 and the gas side shutoff valve 8.

(3) Deformation example In order to ensure that refrigerant leakage treatment such as closing of shutoff valves 7 and 8 is performed when refrigerant leakage is detected during periodic inspections of the air conditioning system 1. It is desirable not only to check the operation of the liquid side shutoff valve 7 and the gas side shutoff valve 8, but also to check the communication connection between the system control unit 11 and the refrigerant leak detection device 9.

Therefore, a signal indicating the presence or absence of refrigerant leakage is simulatedly output from the refrigerant leakage detection device 9, and a simulated signal indicating the presence or absence of this refrigerant is input to the system control unit 11, whereby the liquid side shutoff valve 7 and the liquid side shutoff valve 7 and It is conceivable to perform the shutoff valve inspection process of the above embodiment by opening and closing the gas side shutoff valve 8.

However, when the shutoff valve inspection process is performed by simulating the opening / closing operation of the liquid side shutoff valve 7 and the gas side shutoff valve 8 by inputting a signal indicating the presence or absence of refrigerant leakage output from the refrigerant leak detection device 9. The system control unit 11 needs to be able to distinguish whether the signal output from the refrigerant leakage detection device 9 is a simulated input or a signal indicating the presence or absence of an actual refrigerant leakage. .. This is because when a signal indicating that the refrigerant is leaking is input from the refrigerant leak detecting device 9, the system control unit 11 determines that the refrigerant is really leaking and shuts off the liquid side. This is because the valve 7 and the gas side shutoff valve 8 are closed, and the operation necessary for the shutoff valve inspection process such as operating the compressor 21 in the cooling cycle state or the heating cycle state cannot be performed. That is, when a signal indicating that a refrigerant leak has occurred is input to the system control unit 11 from the refrigerant leakage detection device 9, the refrigerant of the system control unit 11 regardless of whether the signal is a simulated input or not. Refrigerant leakage processing (processing to close the liquid side shutoff valve 7 and gas side shutoff valve 8 to stop the compressor 21) is performed by the leak processing unit 147, and the shutoff valve inspection processing unit 148 of the system control unit 11 This means that the shutoff valve inspection process cannot be performed.

Therefore, here, as shown in FIG. 6, in the shutoff valve inspection process, a signal indicating the presence or absence of refrigerant leakage output from the refrigerant leakage detection device 9 is simulatedly input to the system control unit 11 to the liquid side. A simulated input permission unit 149 for permitting the opening / closing operation of the shutoff valve 7 and the gas side shutoff valve 8 is provided in the system control unit 11 (here, the indoor CPU 141 of the indoor control unit 40). Then, prior to performing the shutoff valve inspection process, the liquid side is subjected to a simulated input of a signal indicating the presence or absence of refrigerant leakage output from the refrigerant leakage detection device 9 through the indoor operation unit 144 or the like of the indoor control unit 40. By inputting to the simulated input permission unit 149 that the shutoff valve 7 and the gas side shutoff valve 8 are to be opened and closed, the refrigerant leak processing unit 147 does not perform refrigerant leakage processing, and the shutoff valve is inspected. The processing unit 148 is permitted to perform the shutoff valve inspection process. By doing so, the system control unit 11 determines that the refrigerant has really leaked by the simulated input of the signal indicating the presence or absence of the refrigerant leak output from the refrigerant leak detection device 9. It is possible to perform operations necessary for the shutoff valve inspection process such as operating the compressor 21 in the cooling cycle state or the heating cycle state.

In this case, the shutoff valve inspection process can be performed by simulating the signal indicating the presence or absence of the refrigerant leak output from the refrigerant leak detection device 9 to the system control unit 11, and the system control can be performed. It is possible to confirm the operation of the liquid side shutoff valve 7 and the gas side shutoff valve 8 as well as confirm the communication connection between the unit 11 and the refrigerant leak detection device 9.

<Second Embodiment>
In the first embodiment and its modification, one indoor unit 4 is connected to the outdoor unit 2 via the refrigerant connecting pipes 5 and 6, and the liquid side shutoff valve 7 and the liquid side shutoff valve 7 correspond to the indoor unit 4. A configuration in which the gas side shutoff valve 8 is provided in the liquid refrigerant pipe 50 and the gas refrigerant pipe 60 (see FIGS. 1 to 3 and 6) is adopted.

However, a plurality of indoor units are connected to the outdoor unit 2 via the refrigerant connecting pipes 5 and 6, and the liquid side shutoff valve and the gas side shutoff valve correspond to each indoor unit to the liquid refrigerant pipe 50 and the gas refrigerant pipe 60. The provided configuration may be adopted.

As such a configuration, for example, as shown in FIGS. 7 to 9, a plurality of (here, two) indoor units 4a and 4b are connected to the outdoor unit 2 via the refrigerant connecting pipes 5 and 6, respectively. There is a configuration in which the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b are provided in the liquid refrigerant pipe 50 and the gas refrigerant pipe 60 corresponding to the indoor units 4a and 4b.

(1) Configuration Next, regarding the configuration of the air conditioning system 1 having a plurality of indoor units 4a and 4b, one indoor unit 4 of the first embodiment is connected to the outdoor unit 2 via the refrigerant connecting pipes 5 and 6. The explanation will focus on the parts that differ from the above configuration.

Specifically, the air conditioning system 1 having a plurality of indoor units 4a and 4b is a system that cools and heats the interior of a building or the like by a vapor compression refrigeration cycle as in the first embodiment. The air conditioning system 1 mainly includes a vapor compression type refrigerant circuit 10 configured by connecting the outdoor unit 2 and the indoor units 4a and 4b via the liquid refrigerant connecting pipe 5 and the gas refrigerant connecting pipe 6. There is. The refrigerant circuit 10 is filled with a slightly flammable refrigerant such as R32 or a highly flammable refrigerant such as R290 as the refrigerant.

The outdoor unit 2 is installed outdoors and mainly has a compressor 21 and an outdoor heat exchanger 24 as in the first embodiment. Here, since the configuration of the outdoor unit 2 is the same as that of the outdoor unit 2 of the first embodiment, the same reference numerals as those of the first embodiment are assigned, and the description thereof will be omitted here.

The indoor unit 4a is installed in the room A and has an indoor heat exchanger 42a, and the indoor unit 4b is installed in the room B and has an indoor heat exchanger 42b. Here, since the configurations of the indoor units 4a and 4b are basically the same as those of the indoor unit 4 of the first embodiment, the subscripts "a" and "b" are added to the same codes as those of the first embodiment. Therefore, the description thereof will be omitted here. However, here, unlike the first embodiment, in order to enable the indoor units 4a and 4b to individually perform the cooling operation and the heating operation, the indoor liquid refrigerant pipe 43a of the indoor unit 4a is connected to the room. An expansion valve 41a is provided, and an indoor expansion valve 41b is provided in the indoor liquid refrigerant pipe 43b of the indoor unit 4b. These indoor expansion valves 41a and 41b are electric expansion valves whose opening degree can be controlled.

Further, here, the liquid refrigerant pipe 50 from the liquid side end of the outdoor unit 2 including the liquid refrigerant connecting pipe 5 to the liquid side end of the indoor heat exchangers 42a and 42b, and the gas refrigerant connecting pipe 6 are included. Liquid-side shutoff valves 7a and 7b that are closed when a refrigerant leak is detected in the gas refrigerant pipe 60 from the gas-side end of the outdoor unit 2 to the gas-side ends of the indoor heat exchangers 42a and 42b. And gas side shutoff valves 8a and 8b are provided. Here, the liquid side shutoff valve 7a is provided in the liquid refrigerant branch pipe 50a of the liquid refrigerant pipe 50 that branches corresponding to the indoor unit 4a, and the liquid side shutoff valve 7b is the liquid refrigerant pipe 50. Of these, the liquid refrigerant branch pipe 50b that branches corresponding to the indoor unit 4b is provided. Further, the gas side shutoff valve 8a is provided in the gas refrigerant branch pipe 60a that branches corresponding to the indoor unit 4a in the gas refrigerant pipe 60, and the gas side shutoff valve 8b is in the gas refrigerant pipe 60. It is provided in the gas refrigerant branch pipe 60b that branches corresponding to the indoor unit 4b. Since the configurations of the shutoff valves 7a, 7b, 8a, and 8b are the same as those of the shutoff valves 7 and 8 of the first embodiment, the subscripts "a" and "b" are added to the same codes as those of the first embodiment. The description will be omitted here.

Further, here, in order to detect the presence or absence of a refrigerant leak on the indoor unit 4a side, a refrigerant leak detection device 9a is provided in the room A, and in order to detect the presence or absence of a refrigerant leak on the indoor unit 4b side. , The refrigerant leakage detection device 9b is provided in the room B. Here, since the configurations of the refrigerant leakage detection devices 9a and 9b are the same as those of the refrigerant leakage detection device 9 of the first embodiment, the subscripts "a" and "b" are added to the same codes as those of the first embodiment. Therefore, the description thereof is omitted here.

Further, here, a system control unit 11 for controlling the constituent devices including the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b is provided. The system control unit 11 controls the outdoor control unit 20 that controls the constituent devices of the outdoor unit 2, the indoor control units 40a and 40b that control the constituent devices of the indoor units 4a and 4b, and the liquid side shutoff valves 7a and 7b. The liquid side shutoff control units 70a and 70b and the gas side shutoff control units 80a and 80b that control the gas side shutoff valves 8a and 8b are connected via a communication line. The outdoor control unit 20 is provided in the outdoor unit 2. The indoor control units 40a and 40b are provided in the indoor units 4a and 4b. The liquid side shutoff control units 70a and 70b are provided on the liquid side shutoff valves 7a and 7b, and the gas side shutoff control units 80a and 80b are provided on the gas side shutoff valves 8a and 8b. Further, the system control unit 11 is also connected to the refrigerant leakage detection control units 90a and 90b that control the refrigerant leakage detection devices 9a and 9b. The refrigerant leakage detection control units 90a and 90b are provided in the refrigerant leakage detection devices 9a and 9b. Here, since the outdoor control unit 20 is the same as the outdoor control unit 20 of the first embodiment, the same reference numerals as those of the first embodiment are assigned, and the description thereof will be omitted here. Further, since the control units 40a, 40b, 70a, 70b, 80a, 80b, 90a, 90b are the same as the control units 40, 70, 80, 90 of the first embodiment, they have the same reference numerals as those of the first embodiment. The subscripts "a" and "b" are added to, and the description thereof will be omitted here.

(2) Operation-Normal operation-
Here, as in the first embodiment, the cooling operation and the heating operation are performed as normal operations. Specifically, when the system control unit 11 is instructed to perform a cooling operation or a heating operation via the indoor operation units 144a and 144b of the indoor control units 40a and 40b, the normal operation processing units 146a of the indoor CPUs 141a and 141b, According to the 146b, basically the same cooling operation and heating operation as those of the first embodiment are executed. However, the indoor expansion valves 41a and 41b are provided in the indoor units 4a and 4b, and the only difference is that the opening degree is controlled in the cooling operation and the heating operation.

-Refrigerant leakage treatment-
When a refrigerant leak is detected in the above normal operation, the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b are closed in order to reduce the amount of the refrigerant leaked into the room. There is a need. Therefore, a signal indicating that the refrigerant is leaking, which is output from the refrigerant leakage detection devices 9a and 9b (refrigerant leakage detection control units 90a and 90b), is input to the system control unit 11 (indoor control units 40a and 40b). Then, the refrigerant leakage processing units 147a and 147b of the indoor CPUs 141a and 141b execute the same refrigerant leakage processing as in the first embodiment.

Specifically, the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b are closed to eliminate the flow of the refrigerant from the outdoor unit 2 to the indoor units 4a and 4b. The compressor 21 also stops. As a result, the amount of refrigerant leaked into the rooms A and B can be reduced, and here, the occurrence of ignition accidents in the room can be suppressed by preventing the flammable refrigerant from exceeding the flammable concentration.

− Shut-off valve inspection process −
Here, basically, as in the first embodiment, as the shutoff valve inspection process for checking the operation of the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b, the liquid side shutoff valves 7a and 7b and The compressor 21 is operated with the gas side shutoff valves 8a and 8b opened, and then the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b are closed. Based on the change in the pressure value, it is determined whether or not the shutoff valve that has been closed is operating normally.

However, in the air conditioning system 1 having a plurality of indoor units 4a and 4b, the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b corresponding to the indoor units 4a and 4b are provided, and the plurality of liquid side shutoff valves 7a are provided. , 7b and the gas side shutoff valves 8a and 8b are simultaneously inspected, and the pressure value changes due to the closing operation of the plurality of liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b at the same time. There is a problem that it occurs and it is not possible to distinguish which shutoff valve is operating normally (or which shutoff valve is not operating normally).

Therefore, here, the shutoff valve inspection process is performed on the corresponding liquid side shutoff valve 7a and gas side shutoff valve 8a for one of the plurality of indoor units 4a and 4b (for example, the indoor unit 4a). At the same time, of the plurality of indoor units 4a and 4b, the indoor unit (for example, the indoor unit 4b) that is not the target of the shutoff valve inspection process is stopped. Therefore, it is possible to determine whether or not the pressure value is changed due to the closing operation of the shutoff valve after distinguishing it from the shutoff valve that is the target of the shutoff valve inspection process. ..

Specifically, the shutoff valve inspection process follows the processes of steps ST1 to ST10 and steps ST11 to ST20 shown in the flowcharts of FIGS. 10 and 11 which are basically the same processes as those of the first embodiment. It is executed for the liquid side shutoff valve and the gas side shutoff valve corresponding to the indoor unit to be inspected. However, at this time, as shown in steps ST1, ST6 and ST11, ST16, the operation of the indoor unit that is not to be inspected is stopped by closing the corresponding indoor expansion valve. In this way, the plurality of indoor units 4a and 4b are subjected to the shutoff valve inspection process for the corresponding liquid side shutoff valve and gas side shutoff valve for one of the plurality of indoor units 4a and 4b. Of these, indoor units that are not subject to shutoff valve inspection processing are stopped from operation. Therefore, it operates normally after distinguishing whether or not there is a change in the pressure value (intake pressure Ps or discharge pressure Pd) due to the closing operation of the shutoff valve due to the shutoff valve that is the target of the shutoff valve inspection process. You can judge whether or not it is.

As a result, here, even if the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b corresponding to the plurality of indoor units 4a and 4b are provided, the plurality of shutoff valves 7a and 7b, respectively. By sequentially checking the operation of 8a and 8b including the shutoff performance, it is possible to determine whether or not each of the shutoff valves 7a, 7b, 8a and 8b is operating normally.

(3) Modification example 1
Also in the above embodiment, as shown in FIG. 12, a signal indicating the presence or absence of refrigerant leakage output from the refrigerant leakage detection devices 9a and 9b is simulated in the system control unit 11 as in the modified example of the first embodiment. The system control unit 11 (here, indoor control) is a simulated input permission unit 149a, 149b for permitting the opening / closing operation of the liquid side shutoff valves 7a and 7b and the gas side shutoff valves 8a and 8b by inputting. It may be provided in the indoor CPUs 141a and 141b) of the parts 40a and 40b.

(4) Modification example 2
In the above embodiment and the first modification, the liquid refrigerant pipes 50 (50a, 50b) are provided with liquid side shutoff valves 7a, 7b corresponding to the indoor units 4a, 4b. However, here, since the liquid refrigerant pipes 50 (50a, 50b) are provided with the indoor expansion valves 41a, 41b corresponding to the indoor units 4a, 4b, when the indoor expansion valves 41a, 41b are closed. When the shutoff performance (valve leakage amount in the closed state, etc.) satisfies the shutoff performance required for the shutoff valve, the indoor expansion valves 41a and 41b may be used in combination with the liquid side shutoff valves 7a and 7b.

<Other embodiments>
In the first and second embodiments and modified examples thereof, a configuration capable of switching between cooling operation and heating operation is adopted, but the present invention is not limited to this. For example, another configuration such as a configuration dedicated to cooling that does not have the switching mechanism 23 may be used.

Further, in the first and second embodiments and modified examples thereof, the refrigerant leakage detection devices 9, 9a and 9b are provided in the room, but the present invention is not limited thereto. For example, it may be provided in another place such as in the indoor units 4, 4a and 4b.

The present invention includes a refrigerant circuit configured by connecting an outdoor unit having a compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger via a refrigerant connecting pipe, and includes a liquid side of the outdoor unit. Refrigerant leakage is detected in the liquid refrigerant pipe from the end to the liquid side end of the indoor heat exchanger and the gas refrigerant pipe from the gas side end of the outdoor unit to the gas side end of the indoor heat exchanger. It is widely applicable to an air conditioning system provided with a shutoff valve that is closed when it is closed.

1 Air conditioning system 2 Outdoor unit 4, 4a, 4b Indoor unit 5 Liquid refrigerant communication pipe 6 Gas refrigerant communication pipe 7, 7a, 7b Liquid side shutoff valve 8, 8a, 8b Gas side shutoff valve 9, 9a, 9b Refrigerant leakage detection Equipment 10 Refrigerant circuit 11 System control unit 21 Compressor 24 Outdoor heat exchanger 35 Intake pressure sensor 36 Discharge pressure sensor 42, 42a, 42b Indoor heat exchanger 50 Liquid refrigerant pipe 60 Gas refrigerant pipe 149, 149a, 149b Simulated input permission unit

Japanese Unexamined Patent Publication No. 2013-19621

Claims (5)

The outdoor unit (2) having the compressor (21) and the outdoor heat exchanger (24) and the indoor unit (4, 4a, 4b) having the indoor heat exchangers (42, 42a, 42b) are connected to the liquid refrigerant connecting pipe (4, 4a, 4b). The indoor heat exchanger includes a refrigerant circuit (10) configured by connecting via 5) and a gas-refrigerant connecting pipe (6) from the liquid-side end of the outdoor unit including the liquid-refrigerant connecting pipe. The liquid refrigerant pipe (50) leading to the liquid side end of the above, and the gas refrigerant pipe (50) from the gas side end of the outdoor unit including the gas refrigerant connecting pipe to the gas side end of the indoor heat exchanger. In an air conditioning system provided with a liquid side shutoff valve (7, 7a, 7b) and a gas side shutoff valve (8, 8a, 8b) that are closed when a refrigerant leak is detected with respect to 60).
The liquid side shutoff valve and the gas side shutoff valve stop the circulation of the refrigerant.
The outdoor unit is provided with a suction pressure sensor (35) that detects the pressure of the refrigerant on the suction side of the compressor.
The system control unit (11) that controls the liquid side shutoff valve and the component equipment including the gas side shutoff valve may perform a shutoff valve inspection process for checking the operation of the liquid side shutoff valve and the gas side shutoff valve. It is possible and
In the shutoff valve inspection process, the compressor is operated in a state where the liquid side shutoff valve and the gas side shutoff valve are opened and the outdoor heat exchanger functions as a radiator of the refrigerant. Based on whether or not the decrease in the pressure value of the refrigerant detected by the suction pressure sensor when one of the liquid-side shutoff valve and the gas-side shutoff valve is closed is equal to or greater than a predetermined decrease. Determining whether one of the liquid-side shutoff valve and the gas-side shutoff valve that have been closed is operating normally.
Air conditioning system (1). The shutoff valve inspection process determines whether or not one of the closed liquid side shutoff valve (7, 7a, 7b) and the gas side shutoff valve (8, 8a, 8b) is operating normally. Later, the suction pressure when one of the closed liquid side shutoff valve and the gas side shutoff valve is opened and then the other of the liquid side shutoff valve and the gas side shutoff valve is closed. Based on the change in the pressure value of the refrigerant detected by the sensor (35), it is determined whether or not the other of the closed liquid side shutoff valve and the gas side shutoff valve is operating normally.
The air conditioning system (1) according to claim 1. The outdoor unit (2) having the compressor (21) and the outdoor heat exchanger (24) and the indoor unit (4, 4a, 4b) having the indoor heat exchangers (42, 42a, 42b) are connected to the liquid refrigerant connecting pipe (4, 4a, 4b). The indoor heat exchanger includes a refrigerant circuit (10) configured by connecting via 5) and a gas-refrigerant connecting pipe (6) from the liquid-side end of the outdoor unit including the liquid-refrigerant connecting pipe. The liquid refrigerant pipe (50) leading to the liquid side end of the above, and the gas refrigerant pipe (50) from the gas side end of the outdoor unit including the gas refrigerant connecting pipe to the gas side end of the indoor heat exchanger. In an air conditioning system provided with a liquid side shutoff valve (7, 7a, 7b) and a gas side shutoff valve (8, 8a, 8b) that are closed when a refrigerant leak is detected with respect to 60).
The liquid side shutoff valve and the gas side shutoff valve stop the circulation of the refrigerant.
The outdoor unit is provided with a discharge pressure sensor (36) that detects the pressure of the refrigerant on the discharge side of the compressor.
The system control unit (11) that controls the liquid side shutoff valve and the component equipment including the gas side shutoff valve may perform a shutoff valve inspection process for checking the operation of the liquid side shutoff valve and the gas side shutoff valve. It is possible and
In the shutoff valve inspection process, the compressor is operated in a state where the liquid side shutoff valve and the gas side shutoff valve are opened and the outdoor heat exchanger functions as an evaporator of the refrigerant. Based on whether or not the increase width of the pressure value of the refrigerant detected by the discharge pressure sensor when one of the liquid side shutoff valve and the gas side shutoff valve is closed is equal to or more than a predetermined increase width. Determining whether one of the liquid-side shutoff valve and the gas-side shutoff valve that have been closed is operating normally.
Air conditioning system (1). The shutoff valve inspection process determines whether or not one of the closed liquid side shutoff valve (7, 7a, 7b) and the gas side shutoff valve (8, 8a, 8b) is operating normally. Later, the discharge pressure when one of the closed liquid side shutoff valve and the gas side shutoff valve is opened and then the other of the liquid side shutoff valve and the gas side shutoff valve is closed. Based on the change in the pressure value of the refrigerant detected by the sensor (36), it is determined whether or not the other of the closed liquid side shutoff valve and the gas side shutoff valve is operating normally.
The air conditioning system (1) according to claim 3. A refrigerant leak detection device (9, 9a, 9b) for detecting the presence or absence of a refrigerant leak is connected to the system control unit (11).
In the shutoff valve inspection process, the system control unit simulates inputting a signal indicating the presence or absence of leakage of the refrigerant output from the refrigerant leak detection device to the system control unit, thereby causing the liquid side shutoff valve ( 7,7a, 7b) and the simulated input permitting unit (149, 149a, 149b) for permitting the opening / closing operation of the gas side shutoff valve (8, 8a, 8b).
The air conditioning system (1) according to any one of claims 1 to 4.

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