JPWO2017119105A1 - Air conditioner - Google Patents

Abstract

An air conditioner that can take measures against refrigerant leakage without the need for additional components. The air conditioner includes an outdoor heat exchanger, an outdoor unit having a compressor, a relay throttle device, a relay having a first on-off valve, and a second on-off valve, and an indoor heat exchanger. And an indoor unit that performs heating, and constitutes a refrigerant circuit in which the refrigerant circulates. When the indoor unit is in the heating operation, the first on-off valve and the relay throttle device are opened, and the refrigerant When the indoor unit is in the cooling operation, the second on-off valve and the relay throttle device are opened to circulate the refrigerant. When the refrigerant leaks, the first on-off valve and the second on-off valve The valve and the relay throttle device are closed, and the refrigerant is the first on-off valve, the second on-off valve, the compressor, the outdoor heat exchanger, and the relay throttle device in the refrigerant circuit. Enclosed in a refrigerant circuit composed of

Description

  The present invention relates to an air conditioner, and particularly relates to measures against refrigerant leakage.

  In the air conditioner, refrigerant that transports heat flows through a pipe provided between the outdoor unit and the indoor unit, and conditioned air is generated. If a crack or the like occurs in a pipe or the like through which the refrigerant flows, the refrigerant leaks, and the human body may be affected by the filled refrigerant.

  In order to prevent the refrigerant in the refrigerant circuit from flowing out to the outside when the refrigerant leaks, the refrigerant is collected by the heat source side unit when the installed detector detects the refrigerant leak, and the outdoor unit and the indoor unit are connected. A method for closing an on-off valve installed in a connection pipe has been proposed.

  For example, Patent Literature 1 discloses an air conditioner in which first and second on-off valves are provided in a refrigerant pipe that connects an indoor unit and an outdoor unit. The first and second on-off valves provided in the outdoor unit are normally open. When the leakage of the refrigerant is detected by the detector of the indoor unit or the outdoor unit, the first and second on-off valves are closed. The refrigerant is prevented from flowing out from the refrigerant circuit of the air conditioner.

Japanese Patent Laying-Open No. 2015-105808

  However, on-off valves installed for countermeasures against refrigerant leakage, such as the first and second on-off valves of Patent Document 1, need to be additionally purchased and installed when they are not attached to the unit. Therefore, in spite of being used only at the time of refrigerant leakage, it is unavoidable that troublesome installation and cost increase occur.

  In addition, the installation of an on-off valve for countermeasures against refrigerant leakage increases the number of parts of the entire air conditioner system and increases the possibility of malfunctions.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an air conditioner capable of taking measures against refrigerant leakage without requiring additional components. And

  An air conditioner according to the present invention includes an outdoor heat exchanger, an outdoor unit having a compressor, a relay throttle device, a relay having a first on-off valve, and a second on-off valve, and an indoor heat exchanger. And an indoor unit that performs cooling and heating, the outdoor heat exchanger, the compressor, the relay throttle device, the first on-off valve, the second on-off valve, and the indoor heat The exchanger constitutes a refrigerant circuit in which the refrigerant circulates, and when the indoor unit is in heating operation, the first on-off valve and the relay throttle device are opened, and the refrigerant is transferred to the outdoor heat exchanger, the compression Machine, the first on-off valve, the indoor heat exchanger, and the repeater throttle device are circulated in this order, and when the indoor unit is in cooling operation, the second on-off valve and the repeater throttle device are in an open state, Refrigerant, the compressor, the outdoor heat exchanger, The relay throttle device, the indoor heat exchanger, and the second on-off valve are circulated in this order, and when the refrigerant leaks, the first on-off valve, the second on-off valve, and the repeater throttle device are closed. The refrigerant is enclosed in a refrigerant circuit including the first on-off valve, the second on-off valve, the compressor, the outdoor heat exchanger, and the relay throttle device in the refrigerant circuit.

  According to the air conditioner of the present invention, relaying from the outdoor unit is performed by sequentially closing the expansion device for the relay that controls the flow of the refrigerant between the outdoor unit and each indoor unit, and the on-off valve. The refrigerant is enclosed before reaching the container. Thereby, it is possible to prevent the refrigerant from leaking in the indoor space.

It is a figure showing the structure of the air conditioning apparatus which concerns on embodiment. It is a figure which shows the flow of the refrigerant | coolant in the refrigerant circuit at the time of a cooling only operation. It is a figure which shows the flow of the refrigerant | coolant in the refrigerant circuit at the time of all heating operation. It is a figure showing the relationship of the apparatus which concerns on the control in the air conditioning apparatus of FIG. It is a flowchart of the process which determines the opening degree of the indoor expansion device of an indoor unit. It is a flowchart of the process at the time of the refrigerant | coolant leakage which an outdoor side controller performs.

Embodiment.
The air conditioning apparatus according to the present embodiment is configured by a plurality of indoor units that perform cooling operation and heating operation, and a cooling only operation, a heating only operation, and a cooling / heating simultaneous operation are performed. FIG. 1 is a diagram illustrating a configuration of an air-conditioning apparatus 100 according to the present embodiment. As shown in FIG. 1, the air conditioning apparatus 100 includes an outdoor unit 51, a plurality of indoor units 52a and 52b, and a repeater 53 between the outdoor unit 51 and the indoor units 52a and 52b. The outdoor unit 51 and the repeater 53 are connected by a first liquid pipe 104 and a first gas pipe 103 through which a refrigerant flows. The repeater 53 and each of the indoor units 52a and 52b are connected by second liquid pipes 105a and 105b and second gas pipes 106a and 106b. The air conditioner 100 is, for example, the air conditioner 100 in which each indoor unit 52a, 52b can independently perform a cooling operation or a heating operation. In the following description, the operation mode when the cooling operation and the heating operation are mixed is referred to as a cooling / heating simultaneous operation mode.

[Outdoor unit 51]
The outdoor unit 51 includes a compressor 1, a four-way valve 3, an outdoor heat exchanger 2, an accumulator 4, and a refrigerant flow control unit 54. The compressor 1 sucks in refrigerant, compresses it, and discharges it. As the compressor 1, for example, an inverter circuit or the like that can change the amount of refrigerant sent out per unit time by capacity control can be used. A first pressure sensor 31 that detects pressure is provided on the discharge side of the compressor 1, and a second pressure sensor 32 that detects pressure is provided on the suction side of the compressor 1. The pressures Pd and Ps detected by the first pressure sensor 31 and the second pressure sensor 32 are sent to the outdoor controller 201. The outdoor side controller 201 functions as a controller that controls the entire air conditioner.

  The outdoor heat exchanger 2 circulates a refrigerant inside, and performs heat exchange between the refrigerant and outdoor air. The outdoor heat exchanger 2 functions as an evaporator during heating operation, and evaporates and vaporizes the refrigerant. Further, during cooling operation, it functions as a condenser and condenses and liquefies the refrigerant. The four-way valve 3 is a valve for switching the flow of the refrigerant, and the operation content such as a cooling operation or a heating operation is changed by the switching. The accumulator 4 stores excess liquid refrigerant. The refrigerant flow control unit 54 allows the refrigerant flow direction in only one direction.

[Refrigerant flow control unit 54]
The refrigerant flow control unit 54 includes connection pipes 130, 131, 132, 133 connected at the connection portions a, b, c, d, and check valves 7a, 7b, 7c, 7d that allow the refrigerant flow in one direction. It is comprised by. The refrigerant flow control unit 54 is a part of the components of the outdoor unit 51. The connection pipe 130 connects the connection part c and the connection part a, the connection pipe 131 connects the connection part d and the connection part b, and the connection pipe 132 connects the connection part c and the connection part d. The connection pipe 133 connects the connection part a and the connection part b. The first gas pipe 103 connected to the relay 53 and the high-pressure pipe 102 connected to the compressor 1 are connected by the connection pipe 132, and the low-pressure pipe 101 connected to the compressor 1 and the relay are connected by the connection pipe 133. A first liquid pipe 104 connected to the vessel 53 is connected.

  The check valve 7a is disposed in the connection pipe 132 and allows the flow of the refrigerant from the connection part c to the connection part d. The check valve 7b is disposed in the connection pipe 133 and allows the refrigerant flow in the direction from the connection part a to the connection part b. The check valve 7c is disposed in the connection pipe 131 and allows the flow of the refrigerant in the direction from the connection part d to the connection part b. The check valve 7d is arranged in the connection pipe 130 and allows the refrigerant flow in the direction from the connection part c to the connection part a.

[Indoor units 52a, 52b]
The indoor units 52a and 52b include indoor heat exchangers 5a and 5b and indoor expansion devices 6a and 6b. The indoor heat exchangers 5a and 5b allow the refrigerant that has passed through the relay 53 to flow inside, and exchange heat between the refrigerant and air to be air-conditioned. The indoor heat exchangers 5a and 5b function as a condenser during the heating operation, and condense and liquefy the refrigerant. The second liquid pipes 105a and 105b connected to the indoor expansion devices 6a and 6b are connected at the indoor trifurcation 55a. The indoor heat exchangers 5a and 5b function as an evaporator during the cooling operation, and evaporate and vaporize the refrigerant. The indoor expansion devices 6a and 6b function as pressure reducing valves and expansion valves, and expand the refrigerant by reducing the pressure. The indoor expansion devices 6a and 6b only need to be able to adjust the pressure of the refrigerant according to the air conditioning load. For example, flow control means such as an electronic expansion valve can be used. In the indoor units 52a and 52b, first temperature sensors 33a and 33b, second temperature sensors 34a and 34b, and leak detectors 41a and 41b are arranged. The first temperature sensors 33a and 33b and the second temperature sensors 34a and 34b detect the temperature of the refrigerant flowing into and out of the indoor heat exchangers 5a and 5b. The leak detectors 41a and 41b measure the concentration of the refrigerant and detect whether or not it is below a certain concentration. The first temperature sensors 33a and 33b, the second temperature sensors 34a and 34b, and the leak detectors 41a and 41b send detected signals to the indoor controllers 202a and 202b.

[Repeater 53]
The relay 53 includes the gas-liquid separator 8, the first on-off valves 9a and 9b, the second on-off valves 10a and 10b, the first expansion device 11, the second expansion device 12, the first heat exchanger 13, and the second The heat exchanger 14 is used. In addition, the 1st aperture device 11 is an example of the repeater aperture device of this invention. Each component of the repeater 53 is controlled by the repeater controller 203 and connected by a bypass pipe 110, a repeater liquid pipe 111, and a repeater gas pipe 112. The repeater 53 is connected to the outdoor unit 51 by the first liquid pipe 104 and the first gas pipe 103, and the indoor units 52a and 52b are connected by the second liquid pipes 105a and 105b and the second gas pipes 106a and 106b. Connected to each. The repeater 53 controls the flow of the refrigerant between the outdoor unit 51 and each of the indoor units 52a and 52b, and the indoor units 52a and 52b perform simultaneous cooling and heating operations.

  The gas-liquid separator 8 separates the refrigerant into a liquid refrigerant and a gas refrigerant, and is connected to the first liquid pipe 104, the relay liquid pipe 111, and the relay gas pipe 112. The first liquid pipe 104 is connected to the gas-liquid separator 8 from the outdoor unit 51, the relay liquid pipe 111 is connected to the gas-liquid separator 8 and the relay trident section 55b, and the relay gas pipe 112 is The gas-liquid separator 8 is connected to each of the first on-off valves 9a and 9b.

  Second gas pipes 106a and 106b are branched and connected to the first on-off valves 9a and 9b and the second on-off valves 10a and 10b, respectively. The first on-off valves 9 a and 9 b open or close the gas refrigerant flowing through the relay gas pipe 112, or pass the refrigerant in the direction of flowing out from the relay 53. The first on-off valves 9a and 9b are opened when the indoor units 52a and 52b connected via the second gas pipes 106a and 106b are performing the heating operation. The second on-off valves 10a and 10b block the gas refrigerant flowing in from the second gas pipes 106a and 106b of the indoor units 52a and 52b or allow the refrigerant to flow into the relay unit 53. The second on-off valves 10a and 10b are opened when the indoor units 52a and 52b connected via the second gas pipes 106a and 106b are performing the cooling operation.

  The 1st heat exchanger 13 distribute | circulates the liquid refrigerant isolate | separated in the gas-liquid separator 8, and the liquid refrigerant which distribute | circulated the 2nd heat exchanger 14, and makes it heat-exchange. The first expansion device 11 decompresses the liquid refrigerant that has passed through the first heat exchanger 13 and causes the liquid refrigerant to flow into the second heat exchanger 14. The 2nd heat exchanger 14 distribute | circulates the refrigerant | coolant decompressed in the 1st expansion device 11, and the liquid refrigerant decompressed in the 2nd expansion device 12, and performs heat exchange. The first heat exchanger 13, the first expansion device 11, and the second heat exchanger 14 are interposed between the gas-liquid separator 8 and the relay trident section 55b, and are connected by the relay liquid pipe 111. Yes. The bypass pipe 110 connects the relay trifurcation 55b and the first gas pipe 103 via the second expansion device 12, the second heat exchanger 14, and the first heat exchanger 13, and collects the liquid refrigerant. Then, return to the outdoor unit 51. As the first throttling device 11 and the second throttling device 12, for example, a flow rate control means capable of precise control of the flow rate by changing the opening degree, such as an electronic expansion valve, may be used.

  Next, the operation of the air conditioning apparatus 100 will be described. The air conditioner 100 performs a cooling only operation, a heating only operation, and a cooling / heating simultaneous operation. Among them, as the simultaneous cooling and heating operation, two operation modes are possible: a heating main operation when the heating load is high, and a cooling main operation when the cooling load is high. Therefore, the air conditioning apparatus 100 can implement four operation modes.

  FIG. 2 is a diagram illustrating a refrigerant flow in the refrigerant circuit during the cooling only operation. The arrows in FIG. 2 indicate the direction of the refrigerant. During the all-cooling operation, both the indoor units 52a and 52b perform the cooling operation, the first on-off valves 9a and 9b of the relay 53 are closed, and the second on-off valves 10a and 10b are opened. As shown in FIG. 2, the refrigerant is compressed in the compressor 1, discharged as a high-temperature and high-pressure gas refrigerant, and flows into the outdoor heat exchanger 2 from the four-way valve 3. In the outdoor heat exchanger 2, the refrigerant is condensed and liquefied by heat exchange with outdoor air, and flows out from the low-pressure pipe 101 to the refrigerant flow control unit 54. In the refrigerant flow control unit 54, the refrigerant passes through the check valve 7 b of the connection pipe 133 without flowing into the connection pipe 130 by the check valve 7 d, flows out of the refrigerant flow control unit 54, and is relayed from the outdoor unit 51. Flows into the vessel 53.

  The refrigerant is separated into liquid refrigerant and gas refrigerant in the gas-liquid separator 8 of the relay 53. During the cooling only operation, all of the refrigerant is liquid refrigerant, so that all of the refrigerant flows into the relay liquid pipe 111 and does not flow through the relay gas pipe 112. While the refrigerant flows through the relay liquid pipe 111, the degree of supercooling is increased in the first heat exchanger 13, the pressure is reduced to the intermediate pressure in the first expansion device 11, and the subcooling is further performed in the second heat exchanger 14. The degree is increased to reach the repeater trifurcation 55b.

  The refrigerant is diverted at the relay trifurcation 55 b, a part flows into the bypass pipe 110, and the other part flows out from the relay 53. The refrigerant that has flowed into the bypass pipe 110 is decompressed to a low pressure in the second expansion device 12, passes through the second heat exchanger 14 and the first heat exchanger 13 in order, and is evaporated by heat exchange to become a gas refrigerant. To the first gas pipe 103. At this time, the refrigerant in the bypass pipe 110 increases the degree of supercooling of the refrigerant flowing through the relay liquid pipe 111 by heat exchange.

  The refrigerant that is diverted at the relay trifurcation 55b and flows out of the relay 53 flows through the second liquid pipes 105a and 105b and flows into the indoor units 52a and 52b, respectively. The refrigerant is decompressed in the indoor expansion devices 6a and 6b of the indoor units 52a and 52b, and then exchanges heat with the air in the air-conditioning target space in the indoor heat exchangers 5a and 5b. The refrigerant cools the air in the air-conditioning target space, evaporates and vaporizes, becomes a gas refrigerant, and flows out of the indoor heat exchangers 5a and 5b. Thereby, cooling of the air-conditioning target space is realized.

  The refrigerant flows through the second gas pipes 106a and 106b from the indoor heat exchangers 5a and 5b, flows out from the indoor units 52a and 52b, flows into the relay 53 again, and passes through the opened second on-off valves 10a and 10b. pass. The refrigerant merges with the refrigerant flowing through the bypass pipe 110 in the first gas pipe 103, flows out of the relay unit 53, and flows into the outdoor unit 51.

  In the outdoor unit 51, the refrigerant passes through the check valve 7 a disposed in the connection pipe 132 of the refrigerant flow control unit 54, and is sucked into the compressor 1 through the accumulator 4. Thereby, the refrigerant circuit is circulated by the refrigerant.

  FIG. 3 is a diagram illustrating a refrigerant flow in the refrigerant circuit during the heating only operation. During the all-heating operation, both the indoor units 52a and 52b perform the heating operation. As shown in FIG. 3, the refrigerant is compressed in the compressor 1 and discharged as a high-temperature and high-pressure gas refrigerant, flows into the refrigerant flow control unit 54 from the four-way valve 3, and reaches the connection portion d. The refrigerant cannot flow through the connection pipe 132 from the connection part d by the check valve 7a, flows into the connection pipe 131, passes through the check valve 7c, and flows out of the outdoor unit 51 while passing through the connection part b.

  The refrigerant flowing out of the outdoor unit 51 flows through the first liquid pipe 104 and flows into the repeater 53. The refrigerant is separated into gas refrigerant and liquid refrigerant in the gas-liquid separator 8 of the relay 53. During the all-heating operation, all the refrigerant is a gas refrigerant and does not flow into the relay liquid pipe 111. The refrigerant that has passed through the gas-liquid separator 8 reaches the first on-off valves 9a and 9b, passes through the open first on-off valves 9a and 9b, and flows out of the relay 53.

  The refrigerant flowing out of the relay unit 53 flows into the indoor units 52a and 52b, exchanges heat with the air in the air-conditioning target space in the indoor heat exchangers 5a and 5b, and condenses while radiating heat to the air in the air-conditioning target space. Liquefaction. Thereby, the air-conditioning target space is heated. The refrigerant passes through the indoor heat exchangers 5a and 5b, is reduced in pressure in the indoor expansion devices 6a and 6b, becomes an intermediate-pressure liquid refrigerant, and flows out of the indoor units 52a and 52b.

  The refrigerant that has flowed out of the indoor units 52a and 52b flows through the second liquid pipes 105a and 105b, flows into the relay unit 53, joins the bypass pipe 110 to the first gas pipe 103 via the relay three-pronged portion 55b, and relays. Out of the vessel 53. The refrigerant flows through the first gas pipe 103 and reaches the connection portion c of the refrigerant flow control unit 54. The refrigerant cannot flow through the high-pressure connection pipe 132 in the connection portion c, passes through the check valve 7d of the connection pipe 130, and flows through the low-pressure pipe 101. The refrigerant evaporates by heat exchange with outdoor air while passing through the outdoor heat exchanger 2 from the low-pressure pipe 101 and is sucked into the compressor 1 through the four-way valve 3 and the accumulator 4. Thereby, the refrigerant circuit is circulated by the refrigerant.

  Next, the simultaneous cooling / heating operation in which the indoor unit 52a performs the heating operation and the indoor unit 52b performs the cooling operation will be described. In this case, the first on-off valve 9a and the second on-off valve 10b of the relay 53 are in the open state, and the first on-off valve 9b and the second on-off valve 10a are in the closed state.

  First, the flow of the refrigerant when performing a cooling main operation in which the cooling load is higher than the heating load will be described. The refrigerant is compressed by the compressor 1, condensed and liquefied by exchanging heat in the outdoor heat exchanger 2, and flows out as a gas-liquid two-phase refrigerant. The amount of refrigerant condensed and liquefied in the outdoor heat exchanger 2, that is, the ratio of gas refrigerant and liquid refrigerant, is determined according to the ratio of cooling load and heating load. When the refrigerant flows out of the outdoor heat exchanger 2, it flows through the low-pressure pipe 101, passes through the check valve 7 b of the refrigerant flow control unit 54, flows out of the outdoor unit 51, and flows through the first liquid pipe 104 to be relayed. Flows into the vessel 53.

  The refrigerant flowing into the relay 53 is separated into the liquid refrigerant and the gas refrigerant in the gas-liquid separator 8, of which the liquid refrigerant flows into the relay liquid pipe 111 and the gas refrigerant flows into the relay gas pipe 112.

  The liquid refrigerant flowing into the relay liquid pipe 111 passes through the first heat exchanger 13, the first expansion device 11, and the second heat exchanger 14, the degree of supercooling is increased, and the liquid refrigerant reaches the relay trifurcation 55b. . In the relay trident section 55 b, the refrigerant is diverted so that a part of the refrigerant flows through the bypass pipe 110 and the other part flows out of the repeater 53. The refrigerant flowing into the bypass pipe 110 from the relay trifurcation 55b absorbs heat and evaporates while passing through the second expansion device 12, the second heat exchanger 14, and the first heat exchanger 13. It vaporizes and reaches the first gas pipe 103.

  The gas refrigerant separated in the gas-liquid separator 8 and flowing into the relay gas pipe 112 reaches the first on-off valves 9a and 9b, passes through the open first on-off valve 9a, and flows out of the relay 53. Then, it flows into the indoor unit 52a through the second gas pipe 106a. The refrigerant passes through the indoor heat exchanger 5a of the indoor unit 52a and condenses and liquefies while dissipating heat to the air in the air-conditioning target space by heat exchange. Thereby, the air-conditioning target space is heated. The refrigerant that has passed through the indoor heat exchanger 5a is depressurized by the indoor expansion device 6a to become an intermediate-pressure liquid refrigerant, flows out of the indoor unit 52a, passes through the second liquid pipe 105a, and reaches the indoor trifurcation 55a. .

  In the indoor trifurcated portion 55a, the refrigerant flowing through the second liquid pipe 105a connected to the indoor unit 52a and the refrigerant that has flowed out of the relay 53 out of the refrigerant divided in the repeater trifurcated portion 55b merge to form the second liquid. The pipe 105b is circulated. The refrigerant is decompressed in the indoor expansion device 6b in the indoor unit 52b from the second liquid pipe 105b and flows into the indoor heat exchanger 5b. In the indoor heat exchanger 5b, the refrigerant evaporates and vaporizes by heat exchange with the air in the air-conditioning target space, and flows out as a gas refrigerant. Thereby, the air-conditioning target space is cooled. The refrigerant that has passed through the indoor heat exchanger 5 b passes through the opened second on-off valve 10 b and reaches the first gas pipe 103.

  The refrigerant that has passed through the second on-off valve 10 b merges with the refrigerant that has passed through the bypass pipe 110 that also reaches the first gas pipe 103, and flows through the first gas pipe 103 to the refrigerant flow control unit 54 of the outdoor unit 51. Inflow. The refrigerant passes through the check valve 7 a provided in the connection pipe 132 of the refrigerant flow control unit 54, and is sucked into the compressor 1 from the four-way valve 3 through the accumulator 4. Thereby, the refrigerant circuit is circulated by the refrigerant.

  Next, the flow of the refrigerant when the heating main operation is performed where the heating load is higher than the cooling load will be described. The refrigerant is compressed and discharged by the compressor 1, passes through the four-way valve 3, and reaches the connection part d of the refrigerant flow control unit 54. Since the refrigerant cannot flow through the connection pipe 132 from the connection part d by the check valve 7a, the refrigerant passes through the check valve 7c provided in the connection pipe 131, flows out of the outdoor unit 51 through the first liquid pipe 104, and repeater 53.

  The refrigerant that has flowed into the relay 53 flows from the gas-liquid separator 8 into the relay gas pipe 112. At this time, since the heating main operation is performed, there is no liquid refrigerant separated in the gas-liquid separator 8, and the refrigerant does not flow into the relay liquid pipe 111. The refrigerant flows through the relay gas pipe 112, reaches the first on-off valves 9a and 9b, passes through the open first on-off valve 9a, flows out of the relay 53, and passes through the second gas pipe 106a. It flows into the indoor unit 52a. The refrigerant passes through the indoor heat exchanger 5a of the indoor unit 52a and condenses and liquefies while dissipating heat to the air in the air-conditioning target space by heat exchange. Thereby, the air-conditioning target space is heated. The refrigerant that has passed through the indoor heat exchanger 5a is depressurized by the indoor expansion device 6a to become an intermediate-pressure liquid refrigerant, flows from the indoor unit 52a into the second liquid pipe 105a, and reaches the indoor trifurcation 55a.

  The refrigerant is diverted at the indoor trifurcation 55a, part of which flows into the repeater 53 and flows through the bypass pipe 110. The other part of the divided refrigerant flows into the indoor unit 52b from the second liquid pipe 105b, is decompressed in the indoor expansion device 6b of the indoor unit 52b, and exchanges heat with air in the air-conditioning target space in the indoor heat exchanger 5b. Is done. Thereby, the refrigerant | coolant which distribute | circulates the indoor heat exchanger 5b evaporates and vaporizes, and air-conditioning object space is cooled. And a refrigerant | coolant distribute | circulates the 2nd gas piping 106b from the indoor heat exchanger 5b, and passes the 2nd on-off valve 10b which is an open state.

  The refrigerant that has passed through the second on-off valve 10 b merges with the refrigerant that has flowed through the bypass pipe 110, flows out of the repeater 53 through the first gas pipe 103, and flows into the outdoor unit 51. In the refrigerant flow control unit 54 of the outdoor unit 51, the refrigerant passes through the check valve 7d disposed in the connection pipe 130 and flows into the outdoor heat exchanger 2 from the low pressure pipe 101. The refrigerant evaporates and drops by heat exchange in the outdoor heat exchanger 2 and is sucked into the compressor 1 through the four-way valve 3 and the accumulator 4. Thereby, the refrigerant circuit is circulated by the refrigerant.

  FIG. 4 is a diagram illustrating the relationship of devices related to control in the air-conditioning apparatus 100 of FIG. As shown in FIG. 4, the outdoor side controller 201 is electrically connected to each of the indoor side controllers 202 a and 202 b and the repeater controller 203. The outdoor side controller 201 has a function as a main controller that controls the air conditioner 100. Moreover, the outdoor side controller 201 has a timer (not shown) for measuring time. The outdoor side controller 201 is based on the information notified from the indoor side controllers 202a and 202b and the repeater controller 203 with respect to each of the indoor side controllers 202a and 202b and the repeater controller 203. Determine and notify instructions. The outdoor controller 201 acquires the pressures Pd and Ps detected by the first pressure sensor 31 and the second pressure sensor 32 provided in the outdoor unit 51, the operating frequency Fa of the compressor 1, and the outdoor heat exchanger 2 capacity AKa is controlled.

  The indoor-side controllers 202a and 202b detect the temperatures T33a and T33b and T34a and T34b with the first temperature sensors 33a and 33b and the second temperature sensors 34a and 34b, and notify the outdoor controller 201 of them. Moreover, the indoor side controllers 202a and 202b detect the presence or absence of refrigerant leakage by the leakage detectors 41a and 41b, and notify the outdoor side controller 201 of them. Further, based on the temperatures T33a and T33b and T34a and T34b, the respective opening degree LEV6a and LEV6b of the indoor expansion devices 6a and 6b are calculated and notified to the indoor expansion devices 6a and 6b.

  In response to an instruction from the outdoor controller 201, the repeater controller 203 notifies the first throttle device 11 and the second throttle device 12 of the openings LEV11 and LEV12, and the first on-off valves 9a and 9b. And instructing the second on-off valves 10a and 10b to open and close.

  FIG. 5 is a flowchart of processing for determining the opening degree LEV6a of the indoor expansion device 6a of the indoor unit 52a. The opening degree LEV6a of the indoor expansion devices 6a and 6b is controlled by a controller that controls the entire air conditioner, and in this example, is controlled by the outdoor controller 201. As shown in FIG. 5, when the operation of the indoor unit 52a is started, the outdoor side controller 201 acquires the initial value LEV6i of the opening degree LEV6a of the indoor expansion device 6a and starts measuring the timer. In step S1, it is determined whether or not the predetermined time tm has elapsed. If it is determined that the predetermined time tm has elapsed, the process proceeds to step S2, the timer is reset to zero, and the process proceeds to step S3. In step S3, the outdoor side controller 201 acquires the temperature T33a and the temperature T34a detected by the first temperature sensor 33a and the second temperature sensor 34a. The temperature T33a and the temperature T34a represent the saturation temperature of the refrigerant and the temperature of the refrigerant. In step S4, the indoor controller 202a calculates the difference SH between the temperature T33a and the temperature T34a.

  In step S5, the outdoor side controller 201 calculates a difference ΔSH between the temperature difference SH and the target value temperature difference SHm. In step S6, the indoor controller 202a calculates a correction value ΔLEV6a of the opening of the indoor expansion device 6a. The correction value ΔLEV6a may be obtained by, for example, calculating a coefficient k2 in advance by a test or the like and multiplying the coefficient k2 by the difference ΔSH. In step S7, the outdoor controller 201 adds the correction value ΔLEV6a to the current opening degree LEV6a of the indoor expansion device 6a, and sets it as a new opening degree LEV6a of the indoor expansion device 6a.

  In step S8, the outdoor side controller 201 determines whether or not to end the operation, and ends the process when determining that the operation is to be ended. For example, the indoor throttling device 6a may be fully closed. If it is determined that the process is not finished, the process returns to step S1, and the processes from step S1 to step S8 are repeated every predetermined time.

  FIG. 6 is a flowchart of a process at the time of refrigerant leakage performed by the outdoor controller 201. As shown in FIG. 6, when the operation of the indoor unit 52a is started, the outdoor side controller 201 starts measuring a timer. In step S11, the outdoor side controller 201 determines whether or not the predetermined time tm2 has elapsed. If it is determined that it has elapsed, the outdoor controller 201 resets the timer in step S12 and proceeds to step S13. In step S13, the outdoor controller 201 determines whether or not refrigerant leakage is detected by the leakage detector 41a. The leak detector 41a may be provided in a space where the indoor unit 52a is disposed. If it is determined in step S13 that refrigerant leakage has been detected, the process proceeds to step S14. If it is determined that refrigerant leakage has not been detected, the process returns to step S11.

  In step S14, the outdoor side controller 201 instructs the start of the cooling only operation, and proceeds to step S15. In step S <b> 15, the outdoor side controller 201 fully closes the opening degrees of the first throttle device 11 and the second throttle device 12 of the relay 53. In step S <b> 16, the outdoor side controller 201 determines whether or not the pressure Ps detected by the second pressure sensor 32 of the outdoor unit 51 is equal to or lower than the pressure a. The pressure a is a value determined in advance by a test or the like, and is an example of a reference value of the present invention. When determining that the pressure Ps is equal to or lower than the pressure a, the outdoor controller 201 proceeds to step S17 and closes the second on-off valves 10a and 10b of the repeater 53. As a result, the first on-off valves 9a and 9b and the second on-off valves 10a and 10b, which are closed by the cooling operation, are all closed. And in step S18, the outdoor side controller 201 complete | finishes control at the time of a refrigerant | coolant leak by stopping the driving | operation of a compressor.

  As described above, the air conditioner 100 is normally operated using the first on-off valves 9a and 9b, the second on-off valves 10a and 10b, the first throttling device 11, and the second throttling device 12. When the leakage of the refrigerant is detected, the cooling operation is started by the indoor units 52a and 52b, the first expansion device 11 and the second expansion device 12 are closed, and the indoor units 52a and 52b are closed. The refrigerant is recovered. Thereafter, the first on-off valves 9a and 9b and the second on-off valves 10a and 10b are closed, and the refrigerant flow is completely blocked. As a result, the refrigerant includes the first on-off valves 9a and 9b, the second on-off valves 10a and 10b, the compressor 1, the outdoor heat exchanger 2, the first expansion device 11, and the second expansion device 12. It is collected and sealed in the pipe connecting the two.

  As described above, the first on-off valves 9a and 9b, the second on-off valves 10a and 10b, the first throttling device 11, and the second throttling are provided even if no on-off valve or the like for when the refrigerant leaks is provided. The control of the device 12 can prevent the refrigerant from flowing out of the indoor units 52a and 52b. Further, there is no need to prepare an additional on-off valve, purchase an on-off valve, or install an additional on-off valve. The number of parts is reduced, the possibility of failure is low, and a highly reliable system can be obtained.

  In addition, since the recovered refrigerant is enclosed in the refrigerant circuit of the outdoor unit 51 and the refrigerant circuit of the relay 53, a comparison is made with a case where an on-off valve for refrigerant leakage is installed in the outdoor unit 51. Thus, a large amount of refrigerant can be sealed. Furthermore, all the refrigerant | coolants can be enclosed by making the piping volume of the refrigerant circuit of the outdoor unit 51 and the repeater 53 into more than the refrigerant | coolant volume of the whole system.

  According to the air conditioner according to the present invention described above, the throttle device that is open during cooling and heating operation, and the first on-off valve and the second on-off valve that are opened and closed by cooling and heating are all connected when refrigerant leaks. Can be closed. Thereby, the flow of the refrigerant is stopped to prevent damage due to the refrigerant leakage, and it is not necessary to provide an on-off valve individually for stopping the flow of the refrigerant when the refrigerant leaks.

  According to the air conditioner according to the present invention, since the refrigerant is discharged from the indoor units 52a and 52b in a state where the refrigerant does not flow into the indoor units 52a and 52b from the relay 53, the refrigerant from the indoor units 52a and 52b is discharged. Leakage can be prevented.

  According to the air conditioner of the present invention, the first on-off valve and the second on-off valve are closed after it is determined that the refrigerant has been recovered by the outdoor unit 51 and the relay 53. Therefore, the refrigerant leaking from the indoor units 52a and 52b can be prevented.

  According to the air conditioner of the present invention, since the operation of the compressor 1 is stopped after the refrigerant circuit is blocked, the leakage of the refrigerant can be reliably stopped.

  According to the air conditioner of the present invention, since the refrigerant is sealed in the refrigerant circuit of the outdoor unit 51 and the relay 53, the outdoor unit 51 and the relay 53 are provided with an on-off valve in the outdoor unit 51. A larger capacity of refrigerant can be accommodated.

  According to the air conditioning apparatus of the present invention, the leakage of the refrigerant is detected by the leakage detector.

  According to the air conditioner according to the present invention, the entire operation of the air conditioner 100 is controlled by the outdoor controller 201 of the outdoor unit 51.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Outdoor heat exchanger, 3 Four way valve, 4 Accumulator, 5a Indoor heat exchanger, 5b Indoor heat exchanger, 6a Indoor expansion device, 6b Indoor expansion device, 7a, 7b, 7c, 7d Check valve, 8 Gas-liquid separator, 9a, 9b 1st on-off valve, 10a, 10b 2nd on-off valve, 11 1st expansion device, 12 2nd expansion device, 13 1st heat exchanger, 14 2nd heat exchanger, 31 1st 1 pressure sensor, 32 second pressure sensor, 33a, 33b first temperature sensor, 34a, 34b second temperature sensor, 41a, 41b leakage detector, 51 outdoor unit, 52a, 52b indoor unit, 53 repeater, 54 control unit , 55a indoor trifurcation, 55b relay trifurcation, 100 air conditioner, 101 low pressure piping, 102 high pressure piping, 103 first gas piping, 104 first liquid piping, 10 5a, 105b Second liquid piping, 106a, 106b Second gas piping, 110 Bypass piping, 111 Repeater liquid piping, 112 Repeater gas piping, 130, 131, 132, 133 Connection piping, 201 Outdoor controller, 202a, 202b Indoor side controller, 203 Repeater controller.

Claims (7)

An outdoor unit having an outdoor heat exchanger and a compressor;
A repeater having a repeater throttle device, a first on-off valve, and a second on-off valve;
An indoor unit having an indoor heat exchanger, for cooling and heating,
The outdoor heat exchanger, the compressor, the relay throttle device, the first on-off valve, the second on-off valve, and the indoor heat exchanger constitute a refrigerant circuit in which refrigerant circulates,
When the indoor unit is in a heating operation, the first on-off valve and the relay throttle device are in an open state, and refrigerant is supplied to the outdoor heat exchanger, the compressor, the first on-off valve, the indoor heat exchanger, Circulate in order of the repeater throttle device,
When the indoor unit is in cooling operation, the second on-off valve and the relay throttle device are opened, and refrigerant is supplied to the compressor, the outdoor heat exchanger, the relay throttle device, and the indoor heat exchanger. Circulate in the order of the second on-off valve,
When the refrigerant leaks, the first on-off valve, the second on-off valve, and the repeater throttle device are in a closed state, and the refrigerant is the first on-off valve, the second on-off valve, Enclosed in a refrigerant circuit composed of the compressor, the outdoor heat exchanger, and the relay throttle device,
Air conditioner. The first on-off valve and the second on-off valve are
When refrigerant leaks,
After the repeater throttle device is closed, it is closed.
The air conditioning apparatus according to claim 1. The first on-off valve and the second on-off valve are
When refrigerant leaks,
When the pressure on the suction side of the compressor is below a reference value, the compressor is closed.
The air conditioning apparatus according to claim 1 or 2. The compressor is
When the first on-off valve and the second on-off valve are closed, the operation is terminated.
The air conditioning apparatus as described in any one of Claims 1-3. The repeater is
The pipe volume of the refrigerant circuit constituted by the outdoor unit and the relay is arranged at a position where it is larger than the volume of the whole refrigerant to be recovered.
The air conditioning apparatus according to any one of claims 1 to 4. Provided with a leak detector for detecting the leakage of the refrigerant,
The air conditioning apparatus as described in any one of Claims 1-5. The outdoor unit is
The outdoor unit, the repeater, and an outdoor controller that controls the operation of the indoor unit,
The outdoor controller is
Starting the cooling operation of the indoor unit when refrigerant leaks;
After starting the cooling operation,
Closing the repeater throttle device; and
After the step of closing the repeater throttle device,
Closing the first on-off valve and the second on-off valve; and
After the step of closing the first on-off valve and the second on-off valve,
Carrying out the step of stopping the operation of the compressor;
The air conditioning apparatus as described in any one of Claims 1-6.

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