WO2019021380A1 - Air conditioner - Google Patents

Air conditioner Download PDF

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Publication number
WO2019021380A1
WO2019021380A1 PCT/JP2017/026958 JP2017026958W WO2019021380A1 WO 2019021380 A1 WO2019021380 A1 WO 2019021380A1 JP 2017026958 W JP2017026958 W JP 2017026958W WO 2019021380 A1 WO2019021380 A1 WO 2019021380A1
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WO
WIPO (PCT)
Prior art keywords
refrigerant
relay
low pressure
pipe
pressure gas
Prior art date
Application number
PCT/JP2017/026958
Other languages
French (fr)
Japanese (ja)
Inventor
幸志 東
要平 馬場
宏亮 浅沼
森本　修
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2019532259A priority Critical patent/JP6779381B2/en
Priority to PCT/JP2017/026958 priority patent/WO2019021380A1/en
Publication of WO2019021380A1 publication Critical patent/WO2019021380A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle

Definitions

  • the present invention relates to an air conditioner having a relay between a heat source unit and a load side unit.
  • the conventional air conditioner includes a heat source unit, a first relay connected to the heat source unit, and a second relay connected to the downstream side of the first relay, the first relay and the first relay Some relay relays the flow of refrigerant between a plurality of indoor units.
  • the first relay and the second relay are connected by three refrigerant pipes.
  • One of the three refrigerant pipes is a liquid pipe that causes liquid refrigerant to flow between the first relay and the second relay.
  • one of the pipes is a high pressure gas pipe in which the first relay supplies high-pressure gas refrigerant to the second relay, and the other pipe is the low pressure refrigerant of the second relay. It is a low pressure gas pipe which returns to 1 relay.
  • the high pressure gas pipe is branched into two pipes of one pipe, and is connected to each second relay. There is.
  • the connection configuration of the low pressure gas pipe and the liquid pipe is similar to that of the high pressure gas pipe.
  • the two high pressure gas pipes branched from the first relay to the two second relays are not provided with a valve for blocking the flow of the refrigerant. Therefore, even when only the indoor unit connected to one of the second relays is operated, the refrigerant having the same pressure is supplied to both of the second relays using two high pressure gas pipes. In this case, the refrigerant is cooled and condensed in the high pressure gas pipe of the other second relay due to the difference between the saturation temperature accompanying the refrigerant pressure and the temperature around the pipe. If the indoor unit connected to the other second relay does not operate, the refrigerant does not flow and stays in that place.
  • the amount of refrigerant stagnation increases as the number of second relays increases, and increases as the volume of piping connecting the first relay and the second relay increases.
  • the volume of the pipe increases as the cross-sectional area of the pipe increases, and increases as the pipe length increases. Further, the larger the difference between the saturation temperature and the temperature around the pipe, the larger the amount of refrigerant stagnation.
  • the amount of refrigerant is sealed in the air conditioner, it is generally only sealed in the volume of the liquid pipe. If the amount of the stagnant refrigerant increases, the amount of refrigerant will be insufficient, and the refrigeration capacity of the operating indoor unit will be reduced.
  • Patent Document 1 discloses an example of a method of preventing the refrigerant from staying.
  • the humidity control unit disclosed in Patent Document 1 is provided with a bypass circuit for returning the refrigerant from the inactive refrigerant circuit to the low pressure side, and a capillary is provided in the bypass circuit.
  • the present invention has been made to solve the above-described problems, and provides an air conditioner that suppresses the amount of refrigerant staying in refrigerant piping.
  • An air conditioner comprises a heat source unit having a heat source side heat exchanger and a compressor, a first relay connected to the heat source unit and a refrigerant pipe, a high pressure gas pipe, a low pressure gas pipe and a liquid pipe.
  • a second relay connected to the first relay, a high pressure valve connected to the high pressure gas pipe, and a low pressure valve connected to the low pressure gas pipe, provided in the second relay
  • a control unit that controls the compressor and the plurality of connection ports, and the control unit stops all load-side units connected to the second relay.
  • the high pressure valve and the low pressure valve of at least one connection port of the plurality of connection ports are opened to perform the refrigerant recovery process of connecting the high pressure gas pipe and the low pressure gas pipe. is there.
  • the valve of the connection port of the second relay on which the refrigerant stagnates is opened, and the refrigerant that stagnates is collected by the heat source unit. The amount of stagnant refrigerant can be suppressed.
  • FIG. 1 is a refrigerant circuit diagram showing one configuration example of the air-conditioning apparatus of Embodiment 1 of the present invention.
  • the air conditioner 1 has a heat source unit 10, a first relay 30, and a plurality of second relays 50a and 50b.
  • the heat source unit 10 and the first relay 30 are connected by a high pressure pipe 23 and a low pressure pipe 22.
  • the first relay 30 and the second relay 50a are connected by the low pressure gas pipe 42, the low pressure gas pipe 42a, the high pressure gas pipe 43, and the high pressure gas pipe 43a.
  • the first relay 30 and the second relay 50b are connected by the low pressure gas pipe 42, the low pressure gas pipe 42b, the high pressure gas pipe 43, and the high pressure gas pipe 43b.
  • the air conditioner 100 is provided with a control unit 90.
  • the second relay 50 a branches the refrigerant flowing out of the heat source unit 10 into a plurality of load side units 70 a and 70 c, combines the refrigerant flowing out of the load side units 70 a and 70 c, and flows out to the first relay 30.
  • the second relay 50a and the load side unit 70a are connected by a gas branch pipe 75a and a liquid branch pipe 76a.
  • the second relay 50a and the load side unit 70c are connected by a gas branch pipe 75c and a liquid branch pipe 76c.
  • a plurality of load side units 70b and 70d are connected to the second relay 50b.
  • the second relay 50b and the load side unit 70b are connected by a gas branch pipe 75b and a liquid branch pipe 76b.
  • the second relay 50b and the load side unit 70d are connected by a gas branch pipe 75d and a liquid branch pipe 76d.
  • FIG. 2 is a figure which shows one structural example of the heat-source equipment and 1st repeater which were shown in FIG.
  • the heat source unit 10 includes a compressor 11, a flow path switching valve 12, a heat source side heat exchanger 13, an accumulator 14, and a flow path adjustment unit 15.
  • the compressor 11 is a variable displacement compressor.
  • the heat source side heat exchanger 13 performs heat exchange between the outside air and the refrigerant, and functions as an evaporator at the time of heating and as a condenser at the time of cooling.
  • the flow path switching valve 12 is connected to the discharge port side of the compressor 11, switches the flow direction of the refrigerant in the heat source unit 10, and switches the heating flow path and the cooling flow path.
  • FIG. 2 shows the case where the flow path switching valve 12 is a four-way valve.
  • the flow path adjustment unit 15 restricts the flow direction of the refrigerant and forms a flow from the heat source unit 10 to the first relay 30 on the high pressure pipe 23 side, and the heat source unit 10 to the heat source machine 10 from the first relay 30 on the low pressure pipe 22 side.
  • Form a flow of The flow path adjustment unit 15 has a first check valve 16, a second check valve 17, a third check valve 18 and a fourth check valve 19.
  • the accumulator 14 stores surplus refrigerant, and is connected to a refrigerant suction port of the compressor 11.
  • the accumulator 14 is provided with a refrigerant amount sensor 25 that detects a refrigerant shortage.
  • the refrigerant amount sensor 25 When the amount of refrigerant becomes less than the reference value, the refrigerant amount sensor 25 outputs an insufficient refrigerant signal indicating that the refrigerant is insufficient.
  • the flow path switching valve 12 is connected to the flow path adjustment unit 15, the accumulator 14, and the heat source side heat exchanger 13.
  • a first check valve 16 and a second check valve 17 provided in the flow path adjustment unit 15 are connected to the low pressure pipe 22.
  • a third check valve 18 and a fourth check valve 19 provided in the flow path adjustment unit 15 are connected to the high pressure pipe 23.
  • the first relay 30 branches the refrigerant into the second relays 50a and 50b and a load-side unit (not shown) connected to the first relay 30.
  • the first relay 30 includes a gas-liquid separator 32, a first heat exchange unit 33, a second heat exchange unit 34, a first flow control device 35, and a second flow control device 36.
  • a first branch unit 46 and a second branch unit 47 are provided.
  • the gas-liquid separator 32 separates the gas phase refrigerant and the liquid phase refrigerant, and is connected to the high pressure pipe 23, the high pressure gas pipe 43 and the liquid pipe 41.
  • the gas-liquid separation device 32 separates the refrigerant flowing from the heat source unit 10 through the high pressure pipe 23 into a gas and a liquid.
  • the gas-liquid separator 32 sends high-pressure gas refrigerant to the high-pressure gas pipe 43 and sends liquid refrigerant to the liquid pipe 41.
  • the first branch unit 46 has connection ports 81 to 84 connected to the heat exchanger of the load side unit.
  • the connection ports 81 to 84 have two on-off valves connected in parallel, for example, two-way valves.
  • the second branch unit 47 has connection ports 85 to 88 connected to the flow control device of the load side unit.
  • the connection ports 85 to 88 have, for example, two check valves connected in parallel.
  • the load side unit is not connected to the first relay 30 in the configuration example shown in FIG. 1, the load side unit may be connected to the first relay 30.
  • the liquid pipe 41 is provided with a first heat exchange unit 33 and a first flow control device 35.
  • the liquid pipe 41 is branched at the refrigerant outlet side of the first flow control device 35, and a bypass liquid pipe 45 is provided.
  • the bypass liquid pipe 45 is connected to the second heat exchange unit 34 and the second branch unit 47.
  • the first heat exchange unit 33 and the second heat exchange unit 34 exchange heat between the inflowing refrigerant and the air to cool the refrigerant.
  • the first flow control device 35 is in the open state when all the load side units 70a to 70d are in the cooling operation, and controls the flow rate of the inflowing liquid refrigerant, and when all the load side units 70a to 70d are in the heating operation, It is closed and blocks the flow of refrigerant.
  • the second flow control device 36 is opened when all the load side units 70a to 70d are in the heating operation, and controls the flow rate of the inflowing liquid refrigerant, and when all the load side units 70a to 70d are in the cooling operation, It is closed and blocks the flow of refrigerant.
  • Second repeaters 50 a and 50 b are connected in parallel to the first repeater 30.
  • the liquid pipe 41 is branched into a liquid pipe 41a connected to the second relay 50a and a liquid pipe 41b connected to the second relay 50b.
  • the low pressure gas pipe 42 is branched into a low pressure gas pipe 42a connected to the second relay 50a and a low pressure gas pipe 42b connected to the second relay 50b.
  • the high pressure gas pipe 43 is branched into a high pressure gas pipe 43a and a high pressure gas pipe 43b.
  • the high pressure gas pipe 43a is connected to the second relay 50a.
  • the high pressure gas pipe 43b is connected to the second relay 50b.
  • FIG. 3 is a diagram showing an example of the second relay shown in FIG. Since the second relays 50a and 50b have the same configuration, the configuration of the second relay 50a will be described here.
  • the second relay 50a includes first branch units 61a and 61c, second branch units 62a and 62c, a third heat exchange unit 52, and a third flow control device 53.
  • the liquid pipe 41 a is connected to the second branch units 62 a and 62 c via the third heat exchange unit 52.
  • the low pressure gas pipe 42a is connected to the first branch units 61a and 61c.
  • the second relay 50 a is provided with a bypass pipe 54 connecting the low pressure gas pipe 42 a and the liquid pipe 51.
  • the bypass pipe 54 is connected to the liquid pipe 51 via the third heat exchange unit 52.
  • a third flow control device 53 is provided between the third heat exchange unit 52 and the second branch unit 62c.
  • the third heat exchange unit 52 exchanges heat between the inflowing refrigerant and the air to cool the refrigerant.
  • the third flow control device 53 switches from the closed state to the open state, and controls the flow rate of the refrigerant.
  • the first branch unit 61a has four connection ports 81a to 84a.
  • the first branch unit 61c has four connection ports 81c to 84c.
  • the gas branch pipe 75a is connected to the connection port 81a, but the piping tips of the other connection ports 82a to 84a have caps.
  • the gas branch pipe 75c is connected to the connection port 81c, but the piping tips of the other connection ports 82c to 84c have caps.
  • the second branch unit 62a has four connection ports 85a to 88a.
  • the second branch unit 62c has four connection ports 85c to 88c.
  • the connection port 85a is connected to the liquid branch pipe 76a, but the piping tips of the other connection ports 86a to 88a have caps.
  • the connection port 85c is connected to the liquid branch pipe 76c, but the piping tips of the other connection ports 86c to 88c have caps.
  • FIG. 4 is a view showing an example of the configuration of the connection port shown in FIG. Since the connection ports 81a to 84a have the same configuration, the configuration of the connection port 81a will be described. Further, since the connection ports 85a to 88a have the same configuration, the configuration of the connection port 85a will be described.
  • the connection port 81 a includes a high pressure valve 121 connected to the high pressure gas pipe 43 a and connected to the high pressure branch pipe 111 and a low pressure valve 122 connected to the low pressure branch pipe 112.
  • the high pressure valve 121 and the low pressure valve 122 are, for example, solenoid valves.
  • the connection port 85 a has a check valve 141 connected to the liquid pipe 41 a and a check valve 142 connected to the liquid pipe 51.
  • the check valve 141 is provided in the branch pipe 131 connected to the liquid pipe 41 a.
  • the check valve 142 is provided in the branch pipe 132 connected to the liquid pipe 51.
  • the high pressure valve 121 is set to the closed state, and the low pressure valve 122 is set to the open state.
  • the refrigerant flowing from the liquid pipe 41a flows through the check valve 141, the liquid branch pipe 76a, the load side unit 70a, the gas branch pipe 75a and the low pressure valve 122 in order and flows into the low pressure gas pipe 42a.
  • the high pressure valve 121 is set to the open state, and the low pressure valve 122 is set to the closed state.
  • the refrigerant flowing from the high pressure gas pipe 43a flows into the liquid pipe 51 through the high pressure valve 121, the gas branch pipe 75a, the load side unit 70a, the liquid branch pipe 76a and the check valve 142 in this order. .
  • the load side unit 70a has a load side heat exchanger 71a and a load side flow control device 72a.
  • the load side heat exchanger 71a and the load side flow control device 72a are connected by refrigerant piping.
  • the load side heat exchanger 71a is connected to the connection port 81a via the gas branch pipe 75a.
  • the load-side flow control device 72a is connected to the connection port 85a via the liquid branch pipe 76a.
  • the load-side heat exchanger 71a exchanges heat between the air in the air-conditioned space and the refrigerant, and functions as a condenser during heating and as an evaporator during cooling.
  • the load-side flow rate control device 72a decompresses and expands the inflowing refrigerant.
  • FIG. 5 is a block diagram showing one configuration example of the control unit shown in FIG.
  • the control unit 90 shown in FIG. 5 has a memory 91 for storing a program, and a CPU (Central Processing Unit) 92 for executing processing in accordance with the program.
  • the CPU 92 has a timer function.
  • the control unit 90 is connected to the compressor 11, the flow path switching valve 12, and the refrigerant amount sensor 25 by signal lines.
  • the control unit 90 is connected to the first flow control device 35, the second flow control device 36, and the third flow control device 53 by signal lines.
  • the control unit 90 is connected to the high pressure valve 121 and the low pressure valve 122 of each connection port of the second relays 50a and 50b by signal lines.
  • the control unit 90 is connected to the load-side flow control devices 72a to 72d by signal lines.
  • the connection means is not limited to wired but may be wireless.
  • the control unit 90 controls the compressor 11, the flow path switching valve 12, the first flow control device 35, the second flow control device 36, and the third flow control device according to the operation state set in the load side units 70a to 70d.
  • the flow control device 53 and the load side flow control devices 72a to 72d are controlled.
  • the controller 90 executes various operation modes. As the operation mode, there are full cooling operation in which all load side units to be operated are cooling operation and all heating operation in which all load side units to be operated are heating operation. Other operation modes include a cooling main operation where the capacity of the cooling operation is larger than the capacity of the heating operation, and a heating main operation where the capacity of the heating operation is larger than the capacity of the cooling operation.
  • the control unit 90 When the control unit 90 receives the refrigerant shortage signal from the refrigerant amount sensor 25, the control unit 90 controls the connection port of any one of the second relays 50 a and 50 b so as to store the stagnant refrigerant in the heat source unit 10. Perform the refrigerant recovery process to return. Specifically, the control unit 90 determines that refrigerant stagnation occurs when there is a second relay in which not all of the connected load-side units are operated among the second relays 50a and 50b. . Then, the control unit 90 selects at least one connection port of the plurality of connection ports connected to the high pressure gas pipe as a control target in the second relay in which all the load side units are not operating. The control unit 90 opens the high pressure valve 121 and the low pressure valve 122 of the selected connection port, and performs a refrigerant recovery process of connecting the high pressure gas pipe and the low pressure gas pipe.
  • a set time for opening the high pressure valve 121 and the low pressure valve 122 may be determined.
  • the control unit 90 closes the low pressure valve 122 and the high pressure valve 121 when the set time has elapsed since the low pressure valve 122 was opened.
  • the set time is stored in the memory 91.
  • connection port when there are a connection port to which the load side unit is not connected and a connection port to which the load side unit is connected but the load side unit is not in operation, among the plurality of connection ports to be controlled
  • the connection port may be selected or the priority may be set.
  • the priority of the connection port to which the load side unit is not connected is set higher than the priority of the connection port to which the load side unit is connected.
  • the control unit 90 determines whether the refrigerant shortage in the heat source unit 10 is determined based on whether the refrigerant shortage signal is received from the refrigerant quantity sensor 25 or not.
  • the case is not limited.
  • the control unit 90 measures the state of the refrigeration cycle, calculates the refrigeration capacity using the measurement values of the temperature sensor and the pressure sensor (not shown), and if the calculated refrigeration capacity is reduced, the refrigerant amount is insufficient You may judge. Even if the air conditioner 1 is provided with a plurality of temperature sensors for measuring temperatures including the outside air temperature and the refrigerant temperature, and a plurality of pressure sensors for measuring the refrigerant pressure including the discharge pressure and the suction pressure of the compressor 11 Good. In this case, the control unit 90 may determine the refrigerant shortage from the measurement values of various sensors.
  • FIG. 1 to FIG. 3 there is shown a case where two load side units are connected to every two second relays 50a and 50b, but in the second relays 50a and 50b
  • the number of connected load units is not limited to two.
  • one load-side unit may be connected to one second relay, and no load-side unit may be connected to another second relay.
  • FIG. 6 is a diagram showing the flow of refrigerant in the second relay when the air conditioning apparatus shown in FIG. 1 is in the cooling only operation.
  • the flow of the refrigerant when the air conditioning apparatus 1 performs the cooling only operation will be described with reference to FIGS. 2 and 6.
  • the direction in which the refrigerant flows is indicated by an arrow. All of the operating states of the load side units 70a to 70d are cooling operation.
  • the compressor 11 shown in FIG. 2 compresses the refrigerant drawn from the accumulator 14 and discharges a high temperature and high pressure gas refrigerant.
  • the gas refrigerant discharged from the compressor 11 flows into the heat source side heat exchanger 13 through the flow path switching valve 12.
  • the gas refrigerant exchanges heat with the outside air, is condensed, and is liquefied.
  • the liquefied refrigerant flows into the first relay 30 through the fourth check valve 19 and the high pressure pipe 23.
  • the liquid refrigerant flows in the order of the gas-liquid separation device 32, the first heat exchange unit 33, and the first flow control device 35.
  • the liquid refrigerant flowing out of the first relay 30 shown in FIG. 2 through the liquid pipe 41 flows into the liquid pipes 41a and 41b shown in FIG.
  • the liquid refrigerant flowing through the liquid pipe 41a flows into the second relay 50a.
  • the liquid refrigerant flowing through the liquid pipe 41b flows into the second relay 50b.
  • the liquid refrigerant flowing into the second relay 50a is branched to the connection ports 85c and 85a.
  • the liquid refrigerant that has flowed into the second relay 50 b flows through the third heat exchange unit 52 and then is branched to the connection ports 85 d and 85 b.
  • the liquid refrigerant flowing through the connection port 85c flows through the liquid branch pipe 76c and flows into the load side unit 70c.
  • the liquid refrigerant flowing through the connection port 85a flows through the liquid branch pipe 76a and flows into the load side unit 70a.
  • the liquid refrigerant flowing through the connection port 85d flows through the liquid branch pipe 76d and flows into the load side unit 70d.
  • the liquid refrigerant flowing through the connection port 85b flows through the liquid branch pipe 76b and flows into the load side unit 70b.
  • the refrigerant flowing into the load side unit 70c is decompressed by the load side flow control device 72c, and then exchanges heat with the air of the air conditioning target space in the load side heat exchanger 71c to evaporate and gasify.
  • the gasified refrigerant flows through the gas branch pipe 75c and flows into the connection port 81c of the second relay 50a.
  • the flow of the refrigerant in the load side units 70a, 70b and 70d is the same as that of the load side unit 70c, so the description thereof will be omitted.
  • the gas refrigerant flowing through the connection port 81c and the gas refrigerant flowing through the connection port 81a merge at the low pressure gas pipe 42a.
  • the gas refrigerant flowing through the connection port 81d and the gas refrigerant flowing through the connection port 81b merge at the low pressure gas pipe 42b.
  • the gas refrigerant flowing through the low pressure gas pipe 42a and the gas refrigerant flowing through the low pressure gas pipe 42b join the low pressure gas pipe 42, and then flow into the first relay 30 shown in FIG.
  • the gas refrigerant that has flowed into the first relay 30 shown in FIG. 2 flows through the low pressure gas pipe 42 and the low pressure pipe 22 and flows into the heat source unit 10.
  • the gas refrigerant that has flowed into the heat source unit 10 flows through the first check valve 16 and the flow path switching valve 12 in order and flows into the accumulator 14.
  • the refrigerant discharged from the compressor 11 carries the heat generated by the heat source unit 10 to the load side units 70a to 70d and cools the air conditioning target space of the load side units 70a to 70d. It returns to the accumulator 14 of ten.
  • FIG. 7 is a diagram showing the flow of the refrigerant in the second relay when the air conditioning apparatus shown in FIG. 1 performs the heating only operation.
  • the direction in which the refrigerant flows is indicated by an arrow.
  • the refrigerant piping through which the high pressure gas refrigerant flows is displayed thick. All of the operating states of the load side units 70a to 70d are heating operations.
  • the high temperature / high pressure gas refrigerant discharged from the compressor 11 shown in FIG. 2 flows through the flow path switching valve 12 and the third check valve 18 and then flows into the first relay 30 via the low pressure pipe 22. .
  • the gas refrigerant is diverted to the high pressure gas pipes 43a and 43b shown in FIG.
  • the gas refrigerant flowing through the high pressure gas pipe 43a flows into the second relay 50a.
  • the gas refrigerant flowing through the high pressure gas pipe 43b flows into the second relay 50b.
  • the gas refrigerant that has flowed into the second relay 50a is branched to the connection ports 81c and 81a.
  • the gas refrigerant that has flowed into the second relay 50b is branched to the connection ports 81d and 81b.
  • the gas refrigerant flowing through the connection port 81c flows through the gas branch pipe 75c and flows into the load side unit 70c.
  • the gas refrigerant flowing through the connection port 81a flows through the gas branch pipe 75a and flows into the load side unit 70a.
  • the gas refrigerant flowing through the connection port 81 d flows through the gas branch pipe 75 d and flows into the load side unit 70 d.
  • the gas refrigerant flowing through the connection port 81b flows through the gas branch pipe 75b and flows into the load side unit 70b.
  • the refrigerant flowing into the load side unit 70c exchanges heat with the air in the air conditioning target space in the load side heat exchanger 71c, is condensed, and is liquefied.
  • the liquefied refrigerant is reduced in pressure by the load-side flow control device 72c, and then flows through the liquid branch pipe 76c to flow into the connection port 85c of the second relay 50a.
  • the flow of the refrigerant in the load side units 70a, 70b and 70d is the same as that of the load side unit 70c, so the description thereof will be omitted.
  • the refrigerant flowing through the connection port 85c and the refrigerant flowing through the connection port 85a flow into the liquid pipe 41a via the liquid pipe 51.
  • the refrigerant flowing through the connection port 85d and the refrigerant flowing through the connection port 85b flow into the liquid pipe 41b via the liquid pipe 51.
  • the refrigerant flowing into the first relay 30 shown in FIG. 2 flows through the low pressure pipe 22 through the second heat exchange unit 34, the second flow control device 36 and the first heat exchange unit 33 in this order. It flows into the heat source unit 10.
  • the refrigerant that has flowed into the heat source unit 10 flows into the heat source side heat exchanger 13 after flowing through the second check valve 17.
  • the liquid refrigerant exchanges heat with the outside air, evaporates, and gasifies.
  • the gasified refrigerant flows into the accumulator 14 after flowing through the flow path switching valve 12.
  • the refrigerant discharged from the compressor 11 carries the heat generated by the heat source unit 10 to the load side units 70a to 70d and warms the air conditioning target space of the load side units 70a to 70d. It returns to the accumulator 14 of ten.
  • FIG. 8 is a diagram showing the flow of the refrigerant in the second relay when the air conditioning apparatus shown in FIG. 1 performs the cooling main operation.
  • the direction in which the refrigerant flows is indicated by an arrow.
  • the refrigerant piping through which the high pressure gas refrigerant flows is displayed thick.
  • the load unit 70c is in the heating operation.
  • the load side units 70a and 70d are in the cooling operation.
  • the load side unit 70 b is stopped.
  • control in the all cooling operation is partially different.
  • points different from the case where the air conditioning apparatus 1 performs the cooling only operation will be described.
  • the liquid refrigerant flows from the heat source unit 10 shown in FIG. 2 through the high pressure pipe and flows into the first relay 30 in the same manner as the case where the operation mode is the cooling only operation.
  • the liquid refrigerant that has flowed into the first relay 30 is separated into high-pressure gas refrigerant and liquid refrigerant in the gas-liquid separator 32. After flowing through the high pressure gas pipe 43, the high pressure gas refrigerant is diverted to the high pressure gas pipes 43a and 43b.
  • the liquid refrigerant separated by the gas-liquid separation device 32 flows through the liquid pipe 41 in the same manner as in the case of the cooling only operation, and then is branched to the liquid pipes 41a and 41b.
  • the liquid refrigerant flowing through the liquid pipe 41a flows into the load side unit 70a via the connection port 85a and the liquid branch pipe 76a.
  • the refrigerant is reduced in pressure by the load side flow control device 72a in the same manner as in the case of the cooling only operation mode, and then exchanges heat with the air in the air conditioned space by the load side heat exchanger 71a. Go and evaporate and gasify.
  • the gasified refrigerant flows through the gas branch pipe 75a and flows into the connection port 81a of the second relay 50a.
  • the gas refrigerant flows from the connection port 81 a to the low pressure gas pipe 42 a, the low pressure gas pipe 42, the first relay 30, and the low pressure pipe 22 in this order, and returns to the heat source unit 10.
  • coolant in the load side unit 70d is the same as that of the load side unit 70a, the description is abbreviate
  • the gas refrigerant flowing through the high pressure gas pipe 43a flows into the load side unit 70c via the connection port 81c and the gas branch pipe 75c in the same manner as in the case of the heating only operation mode.
  • the refrigerant exchanges heat with the air in the space to be air-conditioned in the load side heat exchanger 71c, condenses and liquefies, as in the case of the heating only operation mode.
  • the liquefied refrigerant is reduced in pressure by the load-side flow control device 72c, and then flows through the liquid branch pipe 76c to flow into the connection port 85c of the second relay 50a.
  • the liquefied refrigerant flows into the liquid pipe 51 and is used in the cooling operation of the load side unit 70c.
  • the air conditioning target space of the load side units 70a and 70d is cooled, and the air conditioning target space of the load side unit 70c is warmed.
  • the second relay 50b high-pressure gas refrigerant flows from the first relay 30 through the high-pressure gas pipe 43 and the high-pressure gas pipe 43b even when the load side units 70b and 70d do not perform heating operation. Is supplied to the second repeater 50b.
  • the high pressure valves 121 of the connection ports 81b to 84b and 81d to 84d connected to the high pressure gas pipe 43b are all closed, the gas refrigerant stagnates between the first relay 30 and the second relay 50b.
  • the gas refrigerant that has stagnated is deprived of heat by the surrounding air, the temperature drops, and it stagnates.
  • the heating flow path is set to the heat source unit 10
  • a load side unit (not shown) is connected to the first repeater 30. It is assumed that the load side unit connected to the first relay 30 is performing the heating operation, but not all the load side units connected to the second relays 50a and 50b are operating. In this case, the refrigerant stagnates in the high pressure gas pipes 43, 43a and 43b between the first relay 30 and the second relays 50a and 50b. Even when there is only one second relay connected to the first relay 30, the refrigerant stagnates between the first relay 30 and the second relay 50a.
  • FIG. 9 is a flowchart showing an operation procedure performed by the control unit shown in FIG.
  • the control unit 90 determines whether the refrigerant amount sensor 25 has detected a refrigerant shortage (step S101). When receiving the refrigerant shortage signal from the refrigerant amount sensor 25, the control unit 90 determines that the refrigerant is shortage, and searches for a connection port to be controlled in the refrigerant recovery process (step S102).
  • the refrigerant is between the first relay 30 and the second relays 50a and 50b. It does not stay.
  • Control part 90 excludes the 2nd relay which has a connection port connected with the load side unit which is performing heating operation from control object of refrigerant recovery processing.
  • the control unit 90 selects a connection port to be controlled from among a plurality of connection ports connected to the high pressure gas pipe in the remaining second repeater.
  • the connection port meeting the condition to be controlled is either a connection port to which the load-side unit is not connected or a connection port to which the load-side unit is not operating even if the load-side unit is connected.
  • the control unit 90 selects a connection port meeting the conditions as a control target of the refrigerant recovery process (step S103).
  • the connection port to be selected is represented by a connection port k.
  • k is any one of 81a to 84a.
  • the control unit 90 selects one connection port k in accordance with the set priority. For example, the priority of the connection port to which the load-side unit is not connected is set higher than the priority of the connection port to which the load-side unit is connected.
  • the control unit 90 switches the high pressure valve 121 of the selected connection port k from the closed state to the open state, and switches the low pressure valve 122 from the closed state to the open state (step S104).
  • the refrigerant flows from the high pressure gas pipe to the high pressure valve 121 and the low pressure valve 122 to flow into the low pressure gas pipe.
  • the control unit 90 measures the time from when the low pressure valve 122 is opened, and determines whether the measured time has passed the set time (step S105). When the set time has elapsed, the control unit 90 returns the high pressure valve 121 of the connection port k from the open state to the closed state, and returns the low pressure valve 122 from the open state to the closed state (step S106).
  • connection ports k meeting the conditions in the process of step S102 are the connection ports 82d to 84d and the connection ports 81b to 84b.
  • the control unit 90 selects one of these connection ports, and performs the processes of steps S104 and S105 shown in FIG.
  • the refrigerant accumulated between the first relay 30 and the second relay 50b flows through the high pressure valve 121 and the low pressure valve 122 of the selected connection port k, and then the heat source unit 10 via the low pressure gas pipe 42b.
  • connection port 81b is provided along the distance of the high pressure gas pipe 43 starting from the first relay 30 and the high pressure gas pipe 43b branched from the high pressure gas pipe 43. Distance is the farthest position. In this case, the refrigerant remaining between the first relay 30 and the second relay 50b can be recovered to the low pressure gas pipe 42b with as much as possible.
  • the control unit 90 performs control to open and close the load side flow control device 72b between step S103 and step S104. You may The reason will be described below. Here, the case where the selected connection port k is the connection port 81b will be described.
  • the refrigerant in the gas branch pipe 75b is cooled at the temperature of the surrounding air, and the refrigerant pressure is reduced. Further, the pressure difference between the refrigerant pressure of the low pressure gas pipe 42 b and the refrigerant pressure of the high pressure gas pipe 43 a is large. In this state, when the high pressure valve 121 and the low pressure valve 122 are opened, the high pressure gas refrigerant flows into the gas branch pipe 75b at a stretch. At this time, a large pressure load may be applied to the gas branch pipe 75b and the load side heat exchanger 71b. In addition, the high pressure gas refrigerant may vigorously flow from the high pressure gas pipe 43b to the gas branch pipe 75a and the low pressure gas pipe 42b to generate a sound like a bursting sound.
  • the load side unit 70d since the load side unit 70d is performing the cooling operation, the high-pressure liquid refrigerant flows into the liquid branch pipe 76b. Therefore, when the connection port 81b is selected in step S103 before the process of step S104, the load side flow control device 72b is opened before step S104, and the refrigerant pressure in the gas branch pipe 75b is increased. The pressure is raised to about 1/2 of the refrigerant pressure of the gas pipe 43b. Thereafter, the control unit 90 closes the load-side flow control device 72b, and proceeds to the process of step S104.
  • the control unit 90 reduces the differential pressure between the refrigerant pressure of the low pressure gas pipe 42b and the refrigerant pressure of the high pressure gas pipe 43b.
  • the high pressure valve 121 and the low pressure valve 122 are opened, the force of the refrigerant flowing from the high pressure gas pipe 43b into the low pressure gas pipe 42b is suppressed.
  • application of a large pressure load to the gas branch pipe 75b and the load side heat exchanger 71b is suppressed.
  • the magnitude of the sound generated when the high pressure gas refrigerant flows into the low pressure gas pipe 42b is reduced.
  • the controller 90 performs the refrigerant recovery process when the refrigerant insufficiency is detected is described with reference to FIG. 9, but the refrigerant recovery process detects the refrigerant insufficiency. Not limited to.
  • the load-side unit 70c connected to one second relay 50a of the two second relays 50a and 50b performs a heating operation, and the other unit The second relay 50b has no load side unit that performs heating operation. From this, the control unit 90 performs the heating operation on the load side unit connected to one second relay among the plurality of second relays, and performs the heating operation on the other second relays.
  • control unit 90 may perform the refrigerant recovery process on the other second relays according to the procedure shown in FIG. 9 every fixed time.
  • the load side unit connected to one second relay performs a heating operation, and the heating operation is performed in the other second relays.
  • the present invention is not limited to this case. For example, consider a case where the load side unit 70d connected to the second relay 50b shown in FIG. 8 has stopped operation. In this case, when the refrigerant flowing through the liquid pipe 41b returns to the first relay 30, the load side unit 70d can not return more smoothly than in the case where the cooling operation is performed.
  • the control unit 90 may perform the refrigerant recovery process shown in FIG.
  • the control unit 90 controls the second relay in the following manner.
  • One connection port is selected from a plurality of connection ports connected to the high pressure gas pipe. Then, the control unit 90 opens the high pressure valve 121 and the low pressure valve 122 provided in the selected connection port to connect the high pressure gas pipe and the low pressure gas pipe.
  • the control unit 90 when the control unit 90 is in an operating state where stagnation of refrigerant occurs, the control unit 90 opens the valve of the connection port of the second relay on which the refrigerant is stagnant, so that the stagnant refrigerant is a heat source machine Recover to 10.
  • the stagnating refrigerant is returned to the heat source unit 10, and it is possible to suppress a decrease in refrigeration capacity due to a shortage of the refrigerant.
  • the bypass circuit connecting the high pressure gas pipe and the low pressure gas pipe is always opened As compared with the above, it is possible to suppress the decrease in the freezing capacity.
  • the control unit 90 specifies the connection port where the refrigerant stagnates at the timing of the refrigerant shortage, and performs opening / closing control of the valve in the specified connection port, thereby recovering the refrigerant.
  • the control unit 90 specifies the connection port where the refrigerant stagnates at the timing of the refrigerant shortage, and performs opening / closing control of the valve in the specified connection port, thereby recovering the refrigerant.
  • a decrease in the refrigeration capacity can be prevented, so the restriction on the number of second relays and the pipe length is alleviated. Therefore, in the air conditioning apparatus 1 of the first embodiment, the degree of freedom in the design of the piping system is improved.
  • the second embodiment relates to another configuration example of the connection port connected to the high pressure gas pipe side.
  • the detailed description of the same configuration as that of the first embodiment is omitted.
  • FIG. 10 is a figure which shows one structural example of the connection port in the air conditioning apparatus of Embodiment 2 of this invention.
  • the connection ports 81a to 84a have the same configuration, the configuration of the connection port 81a will be described.
  • the connection ports 85a to 88a are the same as in the first embodiment, and thus the detailed description thereof is omitted.
  • connection port 81a is a low pressure valve connected to the low pressure gas pipe 42a, and is a second low pressure valve connected in parallel with the first low pressure valve 122-1 and the first low pressure valve 122-1. And 122-2.
  • the flow passage cross-sectional area of the first low pressure valve 122-1 is equal to that of the low pressure valve 122 shown in FIG.
  • the flow passage cross-sectional area of the second low pressure valve 122-2 is smaller than the flow passage cross-sectional area of the first low pressure valve 122-1.
  • FIG. 11 is a flowchart showing an example of processing executed by the control unit in the air conditioning apparatus according to Embodiment 2 of the present invention in the processing of step S104 shown in FIG.
  • the case where the control unit 90 performs the refrigerant return process on the connection port 81a will be described.
  • step S104 shown in FIG. 9 the control unit 90 switches the high pressure valve 121 from the closed state to the open state (step S141).
  • the control unit 90 switches the second low pressure valve 122-2 from the closed state to the open state with the first low pressure valve 122-1 closed (step S 142).
  • the second low pressure valve 122-2 is switched from the closed state to the open state, the refrigerant remaining between the first relay 30 and the second relay 50a flows from the high pressure gas pipe 43a to the low pressure gas pipe 42a.
  • the flow passage cross-sectional area of the second low pressure valve 122-2 is smaller than the flow passage cross-sectional area of the first low pressure valve 122-1, a decrease in the refrigeration capacity is suppressed.
  • the refrigerant is prevented from flowing vigorously from the high pressure gas pipe 43a to the low pressure gas pipe 42a.
  • application of a large pressure load to the gas branch pipe 75a and the load side heat exchanger 71a is suppressed.
  • the magnitude of the sound generated when the high pressure gas refrigerant flows into the low pressure gas pipe 42a is reduced.
  • step S105 shown in FIG. 9 when the set time has passed since the second low pressure valve 122-2 was opened, the control unit 90 causes the high pressure valve 121 and the second low pressure valve 122 to go to step S106. -2 switches from the open state to the closed state.
  • the air conditioner 1 of the second embodiment has a second low pressure having a small flow passage cross-sectional area when returning the refrigerant remaining in the high pressure gas pipe between the first relay 30 and the second relay to the heat source unit 10.
  • the valve 122-2 is opened to flow the refrigerant from the high pressure gas pipe to the low pressure gas pipe. Since the flow passage cross-sectional area of the second low pressure valve 122-2 is smaller than the flow passage cross-sectional area of the first low pressure valve 122-1, a decrease in refrigeration capacity is suppressed. According to the second embodiment, not only can the stagnating refrigerant be returned to the heat source unit 10, but also the reduction of the refrigeration capacity is suppressed. Further, since the refrigerant is suppressed from flowing vigorously from the high pressure gas pipe into the low pressure gas pipe, the pressure load on the refrigerant pipe is suppressed, and the magnitude of the generated sound is reduced.
  • the control unit 90 may switch the first low pressure valve 122-1 from the closed state to the open state.
  • the refrigerant is slightly flowing from the high pressure gas pipe 43a into the low pressure gas pipe 42a via the second low pressure valve 122-2.
  • the first low pressure valve 122-1 is opened, the pressure load on the refrigerant pipe and the generation of sound are suppressed. Thereafter, by opening the second low pressure valve 122-2, the refrigerant can be efficiently returned to the heat source unit 10.
  • the setting time is not limited to the determined time.
  • the control unit 90 may update the set time.
  • the control unit 90 may lengthen the set time in proportion to the number of the heat source units 10 being operated. In this case, excessive return of the amount of refrigerant to the heat source unit 10 is suppressed, and an amount of refrigerant suitable for the operating heat source unit 10 can be returned.
  • the amount of refrigerant held by each heat source unit 10 may not be averaged.
  • the refrigerant may be biased to one heat source unit 10 and the other heat source unit 10 may be short of refrigerant.
  • the control unit 90 acquires measurement values from the refrigerant amount sensors 25 of the plurality of heat source units 10, and the refrigerant amounts become uniform among the heat source units 10 As described above, the compressors 11 are controlled, and the amounts of refrigerant of the heat source units 10 are averaged.
  • control unit 90 determines that the amount of refrigerant is insufficient, the control unit 90 extends the set time. It is determined whether the amount of refrigerant is insufficient by comparing the amount of refrigerant appropriate for one heat source unit 10 with the amount of refrigerant calculated by the control unit 90. A reference value is stored in the memory 91 as an appropriate amount of refrigerant for one heat source unit 10. If the calculated amount of refrigerant is less than the reference value, the control unit 90 lengthens the set time.
  • the memory 91 may store the history of the refrigerant recovery process, and the control unit 90 may update the set time with reference to the history of the refrigerant recovery process.
  • the control unit 90 records the time related to the refrigerant recovery process in the memory 91 every time the refrigerant recovery process is performed. Then, the control unit 90 refers to the history of the refrigerant recovery process recorded by the memory, and updates the set time to a longer time as the time interval of the refrigerant recovery process is shorter.
  • the control unit 90 determines whether the amount of refrigerant is insufficient based on the time interval of the refrigerant recovery process stored in the memory 91, and reflects the determination result in the set time.
  • the control unit 90 shortens the set time as the time interval of the refrigerant recovery process is longer, and lengthens the set time as the time interval of the refrigerant recovery process is shorter. By updating the set time in this manner, the amount of refrigerant returned to the heat source unit 10 can be made appropriate, and a decrease in the refrigeration capacity can be suppressed.
  • the control unit 90 updates the set time based on one and both of the number of operating compressors 11 and the time interval of refrigerant recovery. Therefore, the appropriate amount of refrigerant can be recovered to the heat source unit 10 according to the change in the operating state.
  • the memory 91 stores the history of the refrigerant amount in the refrigerant recovery process, and the control unit 90 refers to the history, and the second relay with the best refrigerant recovery efficiency. May be selected. An example of the operation of the control unit 90 in this case will be described.
  • the refrigerant amount sensor 25 has a function of measuring the amount of refrigerant. Every time the refrigerant recovery processing is performed, the control unit 90 associates the second relay to which the connection port to be controlled belongs and the amount of refrigerant measured by the refrigerant amount sensor 25 and records them in the memory 91.
  • the control unit 90 refers to the information recorded in the memory 91 when selecting one connection port in step S103 shown in FIG.
  • the control unit 90 selects one connection port from the second relays recorded in association with the largest refrigerant amount among the recorded refrigerant amounts.
  • the control unit 90 performs the refrigerant recovery process, in order to select the connection port of the second relay having the highest refrigerant recovery efficiency among the plurality of second relays 50a and 50b, The amount of return of the refrigerant to the heat source unit 10 is the largest. As a result, the efficiency of refrigerant recovery can be increased, and a decrease in refrigeration capacity can be suppressed.

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  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
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  • General Engineering & Computer Science (AREA)
  • Air Conditioning Control Device (AREA)
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Abstract

This air conditioner has: a heat source device having a heat-source-side heat exchanger and a compressor; a first relay device connected to the heat source device by refrigerant piping; a second relay device connected to the first relay device by a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe; a plurality of connection ports provided to the second relay device, the plurality of connection ports having a high-pressure valve connected to the high-pressure gas pipe and a low-pressure valve connected to the low-pressure gas pipe; and a control unit that controls the compressor and the plurality of connection ports. When all load-side units connected to the second relay device have stopped, the control unit performs a refrigerant recovery process for opening the high-pressure valve and the low-pressure valve of at least one connection port from among the plurality of connection ports and connecting the high-pressure gas pipe and the low-pressure gas pipe.

Description

空気調和装置Air conditioner
　本発明は、熱源機と負荷側ユニットとの間に中継器を有する空気調和装置に関する。 The present invention relates to an air conditioner having a relay between a heat source unit and a load side unit.
　従来の空気調和装置には、熱源機と、熱源機に接続される第１中継器と、第１中継器の下流側に接続された第２中継器とを有し、第１中継器および第２中継器とが複数の室内機との間の冷媒の流れを中継するものがある。 The conventional air conditioner includes a heat source unit, a first relay connected to the heat source unit, and a second relay connected to the downstream side of the first relay, the first relay and the first relay Some relay relays the flow of refrigerant between a plurality of indoor units.
　第１中継器と第２中継器は、３つ冷媒配管で接続されている。３つの冷媒配管の１つは、第１中継器と第２中継器との間で液冷媒を流通させる液管である。残りの２つの冷媒配管のうち、一方の配管は第１中継器が高圧のガス冷媒を第２中継器に供給する高圧ガス管であり、他方の配管は第２中継器が低圧の冷媒を第１中継器に戻す低圧ガス管である。 The first relay and the second relay are connected by three refrigerant pipes. One of the three refrigerant pipes is a liquid pipe that causes liquid refrigerant to flow between the first relay and the second relay. Among the remaining two refrigerant pipes, one of the pipes is a high pressure gas pipe in which the first relay supplies high-pressure gas refrigerant to the second relay, and the other pipe is the low pressure refrigerant of the second relay. It is a low pressure gas pipe which returns to 1 relay.
　第２中継器が第１中継器の下流側に２つ並列に接続されている場合、高圧ガス管は、１本の配管が２本に分岐して、各第２中継器にそれぞれ接続されている。低圧ガス管および液管の接続構成は、高圧ガス管と同様である。 When two second relays are connected in parallel on the downstream side of the first relay, the high pressure gas pipe is branched into two pipes of one pipe, and is connected to each second relay. There is. The connection configuration of the low pressure gas pipe and the liquid pipe is similar to that of the high pressure gas pipe.
　第１中継器から２つの第２中継器へ分岐する２本の高圧ガス管には、冷媒の流れを遮断する弁は設けられていない。そのため、一方の第２中継器に接続される室内機のみが運転する場合でも、２本の高圧ガス管を用いて、双方の第２中継器に同等圧力の冷媒が供給される。この場合、冷媒圧力に伴う飽和温度と配管の周囲の温度との差により、他方の第２中継器の高圧ガス管で冷媒は、冷却され凝縮する。他方の第２中継器に接続された室内機が運転しないと、冷媒が流れず、その場所に滞留してしまう。 The two high pressure gas pipes branched from the first relay to the two second relays are not provided with a valve for blocking the flow of the refrigerant. Therefore, even when only the indoor unit connected to one of the second relays is operated, the refrigerant having the same pressure is supplied to both of the second relays using two high pressure gas pipes. In this case, the refrigerant is cooled and condensed in the high pressure gas pipe of the other second relay due to the difference between the saturation temperature accompanying the refrigerant pressure and the temperature around the pipe. If the indoor unit connected to the other second relay does not operate, the refrigerant does not flow and stays in that place.
　冷媒が滞留する量は、第２中継器の数が多いほど多く、第１中継器と第２中継器とを接続する配管の容積が大きくなるほど多くなる。配管の容積は、配管の断面積が大きいほど大きく、配管長が長いほど大きくなる。また、飽和温度と配管の周囲の温度との差が大きいほど、冷媒が滞留する量が多くなる。空気調和装置に冷媒量を封入する際、液管の容積分の冷媒量しか封入しないのが一般的である。滞留する冷媒の量が多くなると、冷媒量が不足し、運転する室内機の冷凍能力が低下してしまうことになる。 The amount of refrigerant stagnation increases as the number of second relays increases, and increases as the volume of piping connecting the first relay and the second relay increases. The volume of the pipe increases as the cross-sectional area of the pipe increases, and increases as the pipe length increases. Further, the larger the difference between the saturation temperature and the temperature around the pipe, the larger the amount of refrigerant stagnation. When the amount of refrigerant is sealed in the air conditioner, it is generally only sealed in the volume of the liquid pipe. If the amount of the stagnant refrigerant increases, the amount of refrigerant will be insufficient, and the refrigeration capacity of the operating indoor unit will be reduced.
　冷媒が滞留することを防ぐ方法の一例が、特許文献１に開示されている。特許文献１に開示された調湿ユニットは、休止中の冷媒回路から冷媒を低圧側に戻すバイパス回路が設けられ、バイパス回路にキャピラリが設けられている。 Patent Document 1 discloses an example of a method of preventing the refrigerant from staying. The humidity control unit disclosed in Patent Document 1 is provided with a bypass circuit for returning the refrigerant from the inactive refrigerant circuit to the low pressure side, and a capillary is provided in the bypass circuit.
特開２０１０－７１５９２号公報Unexamined-Japanese-Patent No. 2010-71592
　上述した第２中継器に、高圧ガス管と低圧ガス管との間に、特許文献１に開示されたバイパス回路を設けることが考えられる。しかしながら、バイパス回路のキャピラリに常に冷媒が流れるため、第２中継器に接続される室内機が運転しているか否かに関わらず、冷凍能力が低下してしまう。 It is conceivable to provide a bypass circuit disclosed in Patent Document 1 between the high pressure gas pipe and the low pressure gas pipe in the second relay described above. However, since the refrigerant always flows through the capillary of the bypass circuit, the refrigeration capacity is reduced regardless of whether the indoor unit connected to the second relay is operating.
　本発明は、上記のような課題を解決するためになされたもので、冷媒配管に滞留する冷媒量を抑制する空気調和装置を提供するものである。 The present invention has been made to solve the above-described problems, and provides an air conditioner that suppresses the amount of refrigerant staying in refrigerant piping.
　本発明に係る空気調和装置は、熱源側熱交換器および圧縮機を有する熱源機と、前記熱源機と冷媒配管で接続される第１中継器と、高圧ガス管、低圧ガス管および液管で、前記第１中継器と接続される第２中継器と、前記高圧ガス管に接続される高圧弁と、前記低圧ガス管に接続される低圧弁とを有し、前記第２中継器に設けられた複数の接続ポートと、前記圧縮機および前記複数の接続ポートを制御する制御部と、を有し、前記制御部は、前記第２中継器に接続された負荷側ユニットが全て停止している場合、前記複数の接続ポートのうち、少なくとも１つの接続ポートの前記高圧弁および前記低圧弁を開状態にして、前記高圧ガス管と前記低圧ガス管とを接続させる冷媒回収処理を行うものである。 An air conditioner according to the present invention comprises a heat source unit having a heat source side heat exchanger and a compressor, a first relay connected to the heat source unit and a refrigerant pipe, a high pressure gas pipe, a low pressure gas pipe and a liquid pipe. A second relay connected to the first relay, a high pressure valve connected to the high pressure gas pipe, and a low pressure valve connected to the low pressure gas pipe, provided in the second relay And a control unit that controls the compressor and the plurality of connection ports, and the control unit stops all load-side units connected to the second relay. In this case, the high pressure valve and the low pressure valve of at least one connection port of the plurality of connection ports are opened to perform the refrigerant recovery process of connecting the high pressure gas pipe and the low pressure gas pipe. is there.
　本発明によれば、冷媒の滞留が発生する運転状態になると、冷媒が滞留する第２中継器の接続ポートの弁を開放することで、滞留する冷媒が熱源機に回収されるため、配管に滞留する冷媒量を抑えることができる。 According to the present invention, when the operation state in which the refrigerant stagnates is generated, the valve of the connection port of the second relay on which the refrigerant stagnates is opened, and the refrigerant that stagnates is collected by the heat source unit. The amount of stagnant refrigerant can be suppressed.
本発明の実施の形態１の空気調和装置の一構成例を示す冷媒回路図である。It is a refrigerant circuit figure which shows one structural example of the air conditioning apparatus of Embodiment 1 of this invention. 図１に示した熱源機および第１中継器の一構成例を示す図である。It is a figure which shows the example of 1 structure of the heat-source equipment and 1st repeater which were shown in FIG. 図１に示した第２中継器の一例を示す図である。It is a figure which shows an example of the 2nd repeater shown in FIG. 図３に示す接続ポートの一構成例を示す図である。It is a figure which shows one structural example of the connection port shown in FIG. 図１に示した制御部の一構成例を示すブロック図である。It is a block diagram which shows one structural example of the control part shown in FIG. 図１に示した空気調和装置が全冷房運転の場合における第２中継器の冷媒の流れを示す図である。It is a figure which shows the flow of the refrigerant | coolant of the 2nd relay device in, when the air conditioning apparatus shown in FIG. 1 is cooling-free operation. 図１に示した空気調和装置が全暖房運転を行う場合における第２中継器の冷媒の流れを示す図である。It is a figure which shows the flow of the refrigerant | coolant of a 2nd relay device in, when the air conditioning apparatus shown in FIG. 1 performs a heating only operation. 図１に示した空気調和装置が冷房主体運転を行う場合における第２中継器の冷媒の流れを示す図である。It is a figure which shows the flow of the refrigerant | coolant of a 2nd relay device in, when the air conditioning apparatus shown in FIG. 1 performs cooling main operation. 図５に示した制御部が実行する動作手順を示すフローチャートである。It is a flowchart which shows the operation | movement procedure which the control part shown in FIG. 5 performs. 本発明の実施の形態２の空気調和装置における接続ポートの一構成例を示す図である。It is a figure which shows one structural example of the connection port in the air conditioning apparatus of Embodiment 2 of this invention. 本発明の実施の形態２の空気調和装置における制御部が、図９に示したステップＳ１０４の処理で実行する処理の一例を示すフローチャートである。It is a flowchart which shows an example of the process which the control part in the air conditioning apparatus of Embodiment 2 of this invention performs by the process of step S104 shown in FIG.
実施の形態１．
　本実施の形態１の空気調和装置の構成を説明する。図１は、本発明の実施の形態１の空気調和装置の一構成例を示す冷媒回路図である。図１に示すように、空気調和装置１は、熱源機１０と、第１中継器３０と、複数の第２中継器５０ａおよび５０ｂとを有する。熱源機１０と第１中継器３０とは、高圧管２３および低圧管２２で接続されている。第１中継器３０と第２中継器５０ａとは、低圧ガス管４２、低圧ガス管４２ａ、高圧ガス管４３および高圧ガス管４３ａで接続されている。第１中継器３０と第２中継器５０ｂとは、低圧ガス管４２、低圧ガス管４２ｂ、高圧ガス管４３および高圧ガス管４３ｂで接続されている。空気調和装置１００には、制御部９０が設けられている。 Embodiment 1
The configuration of the air conditioner of Embodiment 1 will be described. FIG. 1 is a refrigerant circuit diagram showing one configuration example of the air-conditioning apparatus of Embodiment 1 of the present invention. As shown in FIG. 1, the air conditioner 1 has a heat source unit 10, a first relay 30, and a plurality of second relays 50a and 50b. The heat source unit 10 and the first relay 30 are connected by a high pressure pipe 23 and a low pressure pipe 22. The first relay 30 and the second relay 50a are connected by the low pressure gas pipe 42, the low pressure gas pipe 42a, the high pressure gas pipe 43, and the high pressure gas pipe 43a. The first relay 30 and the second relay 50b are connected by the low pressure gas pipe 42, the low pressure gas pipe 42b, the high pressure gas pipe 43, and the high pressure gas pipe 43b. The air conditioner 100 is provided with a control unit 90.
　第２中継器５０ａは、熱源機１０から流出する冷媒を複数の負荷側ユニット７０ａおよび７０ｃに分岐させ、負荷側ユニット７０ａおよび７０ｃから流出する冷媒を合流して第１中継器３０に流出する。第２中継器５０ａと負荷側ユニット７０ａとは、ガス枝管７５ａおよび液枝管７６ａで接続されている。第２中継器５０ａと負荷側ユニット７０ｃとは、ガス枝管７５ｃおよび液枝管７６ｃで接続されている。第２中継器５０ｂには、複数の負荷側ユニット７０ｂおよび７０ｄが接続されている。第２中継器５０ｂと負荷側ユニット７０ｂとは、ガス枝管７５ｂおよび液枝管７６ｂで接続されている。第２中継器５０ｂと負荷側ユニット７０ｄとは、ガス枝管７５ｄおよび液枝管７６ｄで接続されている。 The second relay 50 a branches the refrigerant flowing out of the heat source unit 10 into a plurality of load side units 70 a and 70 c, combines the refrigerant flowing out of the load side units 70 a and 70 c, and flows out to the first relay 30. The second relay 50a and the load side unit 70a are connected by a gas branch pipe 75a and a liquid branch pipe 76a. The second relay 50a and the load side unit 70c are connected by a gas branch pipe 75c and a liquid branch pipe 76c. A plurality of load side units 70b and 70d are connected to the second relay 50b. The second relay 50b and the load side unit 70b are connected by a gas branch pipe 75b and a liquid branch pipe 76b. The second relay 50b and the load side unit 70d are connected by a gas branch pipe 75d and a liquid branch pipe 76d.
　図１に示した熱源機１０の構成を説明する。図２は、図１に示した熱源機および第１中継器の一構成例を示す図である。熱源機１０は、圧縮機１１と、流路切替弁１２と、熱源側熱交換器１３と、アキュムレータ１４と、流路調整ユニット１５とを有する。圧縮機１１は、容量可変の圧縮機である。熱源側熱交換器１３は、外気と冷媒との間で熱交換を行うものであり、暖房時には蒸発器として機能し、冷房時には凝縮器として機能する。流路切替弁１２は、圧縮機１１の吐出口側に接続され、熱源機１０における冷媒の流通方向を切り替えて、暖房流路と冷房流路とを切り替える。図２は、流路切替弁１２が四方弁の場合を示す。 The configuration of the heat source unit 10 shown in FIG. 1 will be described. FIG. 2: is a figure which shows one structural example of the heat-source equipment and 1st repeater which were shown in FIG. The heat source unit 10 includes a compressor 11, a flow path switching valve 12, a heat source side heat exchanger 13, an accumulator 14, and a flow path adjustment unit 15. The compressor 11 is a variable displacement compressor. The heat source side heat exchanger 13 performs heat exchange between the outside air and the refrigerant, and functions as an evaporator at the time of heating and as a condenser at the time of cooling. The flow path switching valve 12 is connected to the discharge port side of the compressor 11, switches the flow direction of the refrigerant in the heat source unit 10, and switches the heating flow path and the cooling flow path. FIG. 2 shows the case where the flow path switching valve 12 is a four-way valve.
　流路調整ユニット１５は、冷媒の流通方向を制限し、高圧管２３側では熱源機１０から第１中継器３０への流れを形成し、低圧管２２側では第１中継器３０から熱源機１０への流れを形成する。流路調整ユニット１５は、第１の逆止弁１６、第２の逆止弁１７、第３の逆止弁１８および第４の逆止弁１９を有する。アキュムレータ１４は、余剰冷媒を貯留するものであり、圧縮機１１の冷媒の吸入口に接続されている。アキュムレータ１４には、冷媒不足を検知する冷媒量センサ２５が設けられている。冷媒量センサ２５は、冷媒量が基準値未満になると、冷媒が不足している旨の冷媒不足信号を出力する。流路切替弁１２は、流路調整ユニット１５、アキュムレータ１４および熱源側熱交換器１３と接続されている。 The flow path adjustment unit 15 restricts the flow direction of the refrigerant and forms a flow from the heat source unit 10 to the first relay 30 on the high pressure pipe 23 side, and the heat source unit 10 to the heat source machine 10 from the first relay 30 on the low pressure pipe 22 side. Form a flow of The flow path adjustment unit 15 has a first check valve 16, a second check valve 17, a third check valve 18 and a fourth check valve 19. The accumulator 14 stores surplus refrigerant, and is connected to a refrigerant suction port of the compressor 11. The accumulator 14 is provided with a refrigerant amount sensor 25 that detects a refrigerant shortage. When the amount of refrigerant becomes less than the reference value, the refrigerant amount sensor 25 outputs an insufficient refrigerant signal indicating that the refrigerant is insufficient. The flow path switching valve 12 is connected to the flow path adjustment unit 15, the accumulator 14, and the heat source side heat exchanger 13.
　流路調整ユニット１５に設けられた第１の逆止弁１６および第２の逆止弁１７が、低圧管２２と接続されている。流路調整ユニット１５に設けられた第３の逆止弁１８および第４の逆止弁１９が、高圧管２３と接続されている。 A first check valve 16 and a second check valve 17 provided in the flow path adjustment unit 15 are connected to the low pressure pipe 22. A third check valve 18 and a fourth check valve 19 provided in the flow path adjustment unit 15 are connected to the high pressure pipe 23.
　次に、図２を参照して、第１中継器３０の構成を説明する。第１中継器３０は、第２中継器５０ａおよび５０ｂと、自器に接続される図に示さない負荷側ユニットとに、冷媒を分岐させるものである。第１中継器３０は、気液分離装置３２と、第１の熱交換部３３と、第２の熱交換部３４と、第１の流量制御装置３５と、第２の流量制御装置３６と、第１分岐ユニット４６と、第２分岐ユニット４７とを有する。気液分離装置３２は、気相の冷媒と液相の冷媒とを分離させるものであって、高圧管２３、高圧ガス管４３および液管４１と接続されている。気液分離装置３２は、熱源機１０から高圧管２３を介して流入する冷媒を気体と液体に分離する。気液分離装置３２は、高圧のガス冷媒を高圧ガス管４３に送り出し、液冷媒を液管４１に送り出す。 Next, the configuration of the first repeater 30 will be described with reference to FIG. The first relay 30 branches the refrigerant into the second relays 50a and 50b and a load-side unit (not shown) connected to the first relay 30. The first relay 30 includes a gas-liquid separator 32, a first heat exchange unit 33, a second heat exchange unit 34, a first flow control device 35, and a second flow control device 36. A first branch unit 46 and a second branch unit 47 are provided. The gas-liquid separator 32 separates the gas phase refrigerant and the liquid phase refrigerant, and is connected to the high pressure pipe 23, the high pressure gas pipe 43 and the liquid pipe 41. The gas-liquid separation device 32 separates the refrigerant flowing from the heat source unit 10 through the high pressure pipe 23 into a gas and a liquid. The gas-liquid separator 32 sends high-pressure gas refrigerant to the high-pressure gas pipe 43 and sends liquid refrigerant to the liquid pipe 41.
　第１分岐ユニット４６は、負荷側ユニットの熱交換器に接続される接続ポート８１～８４を有する。接続ポート８１～８４は、並列接続された、例えば、２方弁からなる２つの開閉弁を有する。第２分岐ユニット４７は、負荷側ユニットの流量制御装置に接続される接続ポート８５～８８を有する。接続ポート８５～８８は、並列接続された、例えば、２つの逆止弁を有する。図１に示す構成例では、第１中継器３０に負荷側ユニットが接続されていないが、第１中継器３０に負荷側ユニットが接続されてもよい。 The first branch unit 46 has connection ports 81 to 84 connected to the heat exchanger of the load side unit. The connection ports 81 to 84 have two on-off valves connected in parallel, for example, two-way valves. The second branch unit 47 has connection ports 85 to 88 connected to the flow control device of the load side unit. The connection ports 85 to 88 have, for example, two check valves connected in parallel. Although the load side unit is not connected to the first relay 30 in the configuration example shown in FIG. 1, the load side unit may be connected to the first relay 30.
　液管４１には、第１の熱交換部３３および第１の流量制御装置３５が設けられている。液管４１は、第１の流量制御装置３５の冷媒出口側で分岐され、バイパス液管４５が設けられている。バイパス液管４５は、第２の熱交換部３４および第２分岐ユニット４７と接続されている。第１の熱交換部３３および第２の熱交換部３４は、流入する冷媒と空気との間で熱交換を行って、冷媒を冷却する。第１の流量制御装置３５は、負荷側ユニット７０ａ～７０ｄが全て冷房運転の場合、開状態になり、流入する液冷媒の流量を制御し、負荷側ユニット７０ａ～７０ｄが全て暖房運転の場合、閉状態になり、冷媒の流れを阻止する。第２の流量制御装置３６は、負荷側ユニット７０ａ～７０ｄが全て暖房運転の場合、開状態になり、流入する液冷媒の流量を制御し、負荷側ユニット７０ａ～７０ｄが全て冷房運転の場合、閉状態になり、冷媒の流れを阻止する。 The liquid pipe 41 is provided with a first heat exchange unit 33 and a first flow control device 35. The liquid pipe 41 is branched at the refrigerant outlet side of the first flow control device 35, and a bypass liquid pipe 45 is provided. The bypass liquid pipe 45 is connected to the second heat exchange unit 34 and the second branch unit 47. The first heat exchange unit 33 and the second heat exchange unit 34 exchange heat between the inflowing refrigerant and the air to cool the refrigerant. The first flow control device 35 is in the open state when all the load side units 70a to 70d are in the cooling operation, and controls the flow rate of the inflowing liquid refrigerant, and when all the load side units 70a to 70d are in the heating operation, It is closed and blocks the flow of refrigerant. The second flow control device 36 is opened when all the load side units 70a to 70d are in the heating operation, and controls the flow rate of the inflowing liquid refrigerant, and when all the load side units 70a to 70d are in the cooling operation, It is closed and blocks the flow of refrigerant.
　第２中継器５０ａおよび５０ｂが第１中継器３０に並列に接続されている。液管４１は、第２中継器５０ａと接続される液管４１ａと、第２中継器５０ｂと接続される液管４１ｂとに分岐されている。低圧ガス管４２は、第２中継器５０ａと接続される低圧ガス管４２ａと、第２中継器５０ｂと接続される低圧ガス管４２ｂとに分岐されている。高圧ガス管４３は、高圧ガス管４３ａと高圧ガス管４３ｂとに分岐されている。高圧ガス管４３ａは第２中継器５０ａと接続されている。高圧ガス管４３ｂは第２中継器５０ｂと接続されている。 Second repeaters 50 a and 50 b are connected in parallel to the first repeater 30. The liquid pipe 41 is branched into a liquid pipe 41a connected to the second relay 50a and a liquid pipe 41b connected to the second relay 50b. The low pressure gas pipe 42 is branched into a low pressure gas pipe 42a connected to the second relay 50a and a low pressure gas pipe 42b connected to the second relay 50b. The high pressure gas pipe 43 is branched into a high pressure gas pipe 43a and a high pressure gas pipe 43b. The high pressure gas pipe 43a is connected to the second relay 50a. The high pressure gas pipe 43b is connected to the second relay 50b.
　次に、第２中継器５０ａおよび５０ｂの構成を説明する。図３は、図１に示した第２中継器の一例を示す図である。第２中継器５０ａおよび５０ｂは同一な構成であるため、ここでは、第２中継器５０ａの構成を説明する。 Next, the configuration of the second relays 50a and 50b will be described. FIG. 3 is a diagram showing an example of the second relay shown in FIG. Since the second relays 50a and 50b have the same configuration, the configuration of the second relay 50a will be described here.
　第２中継器５０ａは、第１分岐ユニット６１ａおよび６１ｃと、第２分岐ユニット６２ａおよび６２ｃと、第３の熱交換部５２と、第３の流量制御装置５３とを有する。液管４１ａは、第３の熱交換部５２を介して第２分岐ユニット６２ａおよび６２ｃと接続されている。低圧ガス管４２ａは、第１分岐ユニット６１ａおよび６１ｃと接続されている。第２中継器５０ａには、低圧ガス管４２ａと液管５１とを接続するバイパス管５４が設けられている。バイパス管５４は、第３の熱交換部５２を介して液管５１と接続されている。バイパス管５４において、第３の熱交換部５２と第２分岐ユニット６２ｃとの間に第３の流量制御装置５３が設けられている。第３の熱交換部５２は、流入する冷媒と空気との間で熱交換を行って、冷媒を冷却する。第３の流量制御装置５３は、液管４１ａに流れる液冷媒を気化させて第１中継器３０に戻す場合に、閉状態から開状態に切り替わり、冷媒の流量を制御する。 The second relay 50a includes first branch units 61a and 61c, second branch units 62a and 62c, a third heat exchange unit 52, and a third flow control device 53. The liquid pipe 41 a is connected to the second branch units 62 a and 62 c via the third heat exchange unit 52. The low pressure gas pipe 42a is connected to the first branch units 61a and 61c. The second relay 50 a is provided with a bypass pipe 54 connecting the low pressure gas pipe 42 a and the liquid pipe 51. The bypass pipe 54 is connected to the liquid pipe 51 via the third heat exchange unit 52. In the bypass pipe 54, a third flow control device 53 is provided between the third heat exchange unit 52 and the second branch unit 62c. The third heat exchange unit 52 exchanges heat between the inflowing refrigerant and the air to cool the refrigerant. When the liquid refrigerant flowing in the liquid pipe 41a is vaporized and returned to the first relay 30, the third flow control device 53 switches from the closed state to the open state, and controls the flow rate of the refrigerant.
　第１分岐ユニット６１ａは、４つの接続ポート８１ａ～８４ａを有する。第１分岐ユニット６１ｃは、４つの接続ポート８１ｃ～８４ｃを有する。接続ポート８１ａはガス枝管７５ａが接続されているが、他の接続ポート８２ａ～８４ａの配管先端にはキャップが付いている。接続ポート８１ｃはガス枝管７５ｃが接続されているが、他の接続ポート８２ｃ～８４ｃの配管先端にはキャップが付いている。 The first branch unit 61a has four connection ports 81a to 84a. The first branch unit 61c has four connection ports 81c to 84c. The gas branch pipe 75a is connected to the connection port 81a, but the piping tips of the other connection ports 82a to 84a have caps. The gas branch pipe 75c is connected to the connection port 81c, but the piping tips of the other connection ports 82c to 84c have caps.
　第２分岐ユニット６２ａは、４つの接続ポート８５ａ～８８ａを有する。第２分岐ユニット６２ｃは、４つの接続ポート８５ｃ～８８ｃを有する。接続ポート８５ａは液枝管７６ａが接続されているが、他の接続ポート８６ａ～８８ａの配管先端にはキャップが付いている。接続ポート８５ｃは液枝管７６ｃが接続されているが、他の接続ポート８６ｃ～８８ｃの配管先端にはキャップが付いている。 The second branch unit 62a has four connection ports 85a to 88a. The second branch unit 62c has four connection ports 85c to 88c. The connection port 85a is connected to the liquid branch pipe 76a, but the piping tips of the other connection ports 86a to 88a have caps. The connection port 85c is connected to the liquid branch pipe 76c, but the piping tips of the other connection ports 86c to 88c have caps.
　図４は、図３に示す接続ポートの一構成例を示す図である。接続ポート８１ａ～８４ａは互いに同様な構成なため、接続ポート８１ａの構成を説明する。また、接続ポート８５ａ～８８ａは互いに同様な構成なため、接続ポート８５ａの構成を説明する。 FIG. 4 is a view showing an example of the configuration of the connection port shown in FIG. Since the connection ports 81a to 84a have the same configuration, the configuration of the connection port 81a will be described. Further, since the connection ports 85a to 88a have the same configuration, the configuration of the connection port 85a will be described.
　接続ポート８１ａは、高圧ガス管４３ａに接続され、高圧分岐配管１１１に接続された高圧弁１２１と、低圧分岐配管１１２に接続された低圧弁１２２とを有する。高圧弁１２１および低圧弁１２２は、例えば、電磁弁からなる。接続ポート８５ａは、液管４１ａに接続される逆止弁１４１と、液管５１に接続される逆止弁１４２とを有する。逆止弁１４１は、液管４１ａに接続された分岐配管１３１に設けられている。逆止弁１４２は、液管５１に接続された分岐配管１３２に設けられている。 The connection port 81 a includes a high pressure valve 121 connected to the high pressure gas pipe 43 a and connected to the high pressure branch pipe 111 and a low pressure valve 122 connected to the low pressure branch pipe 112. The high pressure valve 121 and the low pressure valve 122 are, for example, solenoid valves. The connection port 85 a has a check valve 141 connected to the liquid pipe 41 a and a check valve 142 connected to the liquid pipe 51. The check valve 141 is provided in the branch pipe 131 connected to the liquid pipe 41 a. The check valve 142 is provided in the branch pipe 132 connected to the liquid pipe 51.
　負荷側ユニット７０ａの運転状態が冷房運転の場合、高圧弁１２１が閉状態に設定され、低圧弁１２２が開状態に設定される。冷房運転の場合、液管４１ａから流入する冷媒は、逆止弁１４１、液枝管７６ａ、負荷側ユニット７０ａ、ガス枝管７５ａおよび低圧弁１２２を順に流通して、低圧ガス管４２ａに流入する。負荷側ユニット７０ａの運転状態が暖房運転の場合、高圧弁１２１が開状態に設定され、低圧弁１２２が閉状態に設定される。暖房運転の場合、高圧ガス管４３ａから流入する冷媒は、高圧弁１２１、ガス枝管７５ａ、負荷側ユニット７０ａ、液枝管７６ａおよび逆止弁１４２を順に流通して、液管５１に流入する。 When the operation state of the load side unit 70a is the cooling operation, the high pressure valve 121 is set to the closed state, and the low pressure valve 122 is set to the open state. In the case of the cooling operation, the refrigerant flowing from the liquid pipe 41a flows through the check valve 141, the liquid branch pipe 76a, the load side unit 70a, the gas branch pipe 75a and the low pressure valve 122 in order and flows into the low pressure gas pipe 42a. . When the operation state of the load side unit 70a is the heating operation, the high pressure valve 121 is set to the open state, and the low pressure valve 122 is set to the closed state. In the case of heating operation, the refrigerant flowing from the high pressure gas pipe 43a flows into the liquid pipe 51 through the high pressure valve 121, the gas branch pipe 75a, the load side unit 70a, the liquid branch pipe 76a and the check valve 142 in this order. .
　次に、図３を参照して、負荷側ユニット７０ａ～７０ｄの構成を説明する。負荷側ユニット７０ａ～７０ｄは同様な構成であるため、ここでは、負荷側ユニット７０ａの構成を説明する。負荷側ユニット７０ａは、負荷側熱交換器７１ａと、負荷側流量制御装置７２ａとを有する。負荷側熱交換器７１ａおよび負荷側流量制御装置７２ａは冷媒配管で接続されている。負荷側熱交換器７１ａは、ガス枝管７５ａを介して接続ポート８１ａと接続されている。負荷側流量制御装置７２ａは、液枝管７６ａを介して接続ポート８５ａと接続されている。負荷側熱交換器７１ａは、空調対象空間の空気と冷媒との間で熱交換を行うものであり、暖房時には凝縮器として機能し、冷房時には蒸発器として機能する。負荷側流量制御装置７２ａは、流入する冷媒を減圧して膨張させる。 Next, with reference to FIG. 3, the configuration of the load side units 70a to 70d will be described. Since the load side units 70a to 70d have the same configuration, the configuration of the load side unit 70a will be described here. The load side unit 70a has a load side heat exchanger 71a and a load side flow control device 72a. The load side heat exchanger 71a and the load side flow control device 72a are connected by refrigerant piping. The load side heat exchanger 71a is connected to the connection port 81a via the gas branch pipe 75a. The load-side flow control device 72a is connected to the connection port 85a via the liquid branch pipe 76a. The load-side heat exchanger 71a exchanges heat between the air in the air-conditioned space and the refrigerant, and functions as a condenser during heating and as an evaporator during cooling. The load-side flow rate control device 72a decompresses and expands the inflowing refrigerant.
　次に、図１に示した制御部９０の構成を説明する。図５は、図１に示した制御部の一構成例を示すブロック図である。図５に示す制御部９０は、プログラムを記憶するメモリ９１と、プログラムにしたがって処理を実行するＣＰＵ（Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）９２とを有する。ＣＰＵ９２はタイマーの機能を備えている。 Next, the configuration of the control unit 90 shown in FIG. 1 will be described. FIG. 5 is a block diagram showing one configuration example of the control unit shown in FIG. The control unit 90 shown in FIG. 5 has a memory 91 for storing a program, and a CPU (Central Processing Unit) 92 for executing processing in accordance with the program. The CPU 92 has a timer function.
　制御部９０は、圧縮機１１、流路切替弁１２および冷媒量センサ２５と信号線で接続されている。制御部９０は、第１の流量制御装置３５、第２の流量制御装置３６および第３の流量制御装置５３と信号線で接続されている。制御部９０は、第２中継器５０ａおよび５０ｂにおける各接続ポートの高圧弁１２１および低圧弁１２２と信号線で接続されている。制御部９０は、負荷側流量制御装置７２ａ～７２ｄと信号線で接続されている。接続手段は、有線に限らず、無線であってもよい。 The control unit 90 is connected to the compressor 11, the flow path switching valve 12, and the refrigerant amount sensor 25 by signal lines. The control unit 90 is connected to the first flow control device 35, the second flow control device 36, and the third flow control device 53 by signal lines. The control unit 90 is connected to the high pressure valve 121 and the low pressure valve 122 of each connection port of the second relays 50a and 50b by signal lines. The control unit 90 is connected to the load-side flow control devices 72a to 72d by signal lines. The connection means is not limited to wired but may be wireless.
　制御部９０は、負荷側ユニット７０ａ～７０ｄに設定される運転状態に合わせて、圧縮機１１、流路切替弁１２、第１の流量制御装置３５、第２の流量制御装置３６、第３の流量制御装置５３および負荷側流量制御装置７２ａ～７２ｄを制御する。制御部９０は、各種運転モードを実行する。運転モードとして、運転する全ての負荷側ユニットが冷房運転である全冷房運転と、運転する全ての負荷側ユニットが暖房運転である全暖房運転とがある。他の運転モードとして、冷房運転の容量が暖房運転の容量よりも大きい冷房主体運転と、暖房運転の容量が冷房運転の容量よりも大きい暖房主体運転とがある。 The control unit 90 controls the compressor 11, the flow path switching valve 12, the first flow control device 35, the second flow control device 36, and the third flow control device according to the operation state set in the load side units 70a to 70d. The flow control device 53 and the load side flow control devices 72a to 72d are controlled. The controller 90 executes various operation modes. As the operation mode, there are full cooling operation in which all load side units to be operated are cooling operation and all heating operation in which all load side units to be operated are heating operation. Other operation modes include a cooling main operation where the capacity of the cooling operation is larger than the capacity of the heating operation, and a heating main operation where the capacity of the heating operation is larger than the capacity of the cooling operation.
　制御部９０は、冷媒量センサ２５から冷媒不足信号を受信すると、第２中継器５０ａおよび５０ｂのうち、いずれかの第２中継器の接続ポートを制御して、滞留する冷媒を熱源機１０に戻す冷媒回収処理を行う。具体的には、制御部９０は、第２中継器５０ａおよび５０ｂのうち、接続される負荷側ユニットの全てが運転していない第２中継器があると、冷媒の滞留が起きる状態と判定する。そして、制御部９０は、負荷側ユニットの全てが運転していない第２中継器において、高圧ガス管に接続される複数の接続ポートのうち、少なくとも１つの接続ポートを制御対象に選択する。制御部９０は、選択した接続ポートの高圧弁１２１および低圧弁１２２を開状態にして、高圧ガス管と低圧ガス管とを接続させる冷媒回収処理を行う。 When the control unit 90 receives the refrigerant shortage signal from the refrigerant amount sensor 25, the control unit 90 controls the connection port of any one of the second relays 50 a and 50 b so as to store the stagnant refrigerant in the heat source unit 10. Perform the refrigerant recovery process to return. Specifically, the control unit 90 determines that refrigerant stagnation occurs when there is a second relay in which not all of the connected load-side units are operated among the second relays 50a and 50b. . Then, the control unit 90 selects at least one connection port of the plurality of connection ports connected to the high pressure gas pipe as a control target in the second relay in which all the load side units are not operating. The control unit 90 opens the high pressure valve 121 and the low pressure valve 122 of the selected connection port, and performs a refrigerant recovery process of connecting the high pressure gas pipe and the low pressure gas pipe.
　高圧弁１２１および低圧弁１２２を開状態にする設定時間が決められていてもよい。制御部９０は、低圧弁１２２を開状態にしてから設定時間が経過すると、低圧弁１２２および高圧弁１２１を閉じる。設定時間はメモリ９１に記録されている。 A set time for opening the high pressure valve 121 and the low pressure valve 122 may be determined. The control unit 90 closes the low pressure valve 122 and the high pressure valve 121 when the set time has elapsed since the low pressure valve 122 was opened. The set time is stored in the memory 91.
　また、制御対象となる複数の接続ポートに、負荷側ユニットが接続されていない接続ポートと、負荷側ユニットが接続されているが負荷側ユニットが運転していない接続ポートとがある場合、いずれの接続ポートを選択するか、優先順位が設定されていてもよい。例えば、負荷側ユニットが接続されていない接続ポートの優先順位が、負荷側ユニットが接続されている接続ポートの優先順位よりも高く設定される。負荷側ユニットが接続されている接続ポートの弁が開くとき、高圧ガス管から低圧ガス管に流れ込む冷媒の圧力が負荷側ユニットの負荷側熱交換器等の機器に影響を及ぼすことを抑制できるからである。 In addition, when there are a connection port to which the load side unit is not connected and a connection port to which the load side unit is connected but the load side unit is not in operation, among the plurality of connection ports to be controlled The connection port may be selected or the priority may be set. For example, the priority of the connection port to which the load side unit is not connected is set higher than the priority of the connection port to which the load side unit is connected. When the valve of the connection port to which the load side unit is connected is opened, the pressure of the refrigerant flowing from the high pressure gas pipe into the low pressure gas pipe can be prevented from affecting the equipment such as the load side heat exchanger of the load side unit It is.
　本実施の形態１では、制御部９０が熱源機１０における冷媒不足を冷媒量センサ２５から冷媒不足信号を受信するか否かで判定する場合で説明するが、冷媒量の不足はセンサで検知させる場合に限らない。制御部９０は、冷凍サイクルの状態を測定する、図に示さない温度センサおよび圧力センサの測定値を用いて冷凍能力を算出し、算出した冷凍能力が低下すると、冷媒量が不足していると判定してもよい。外気温度および冷媒温度を含む温度を測定する複数の温度センサと、圧縮機１１の吐出圧力および吸入圧力を含む冷媒圧力を測定する複数の圧力センサとが、空気調和装置１に設けられていてもよい。この場合、制御部９０は、各種センサの測定値から冷媒不足を判定してもよい。 In the first embodiment, the control unit 90 determines whether the refrigerant shortage in the heat source unit 10 is determined based on whether the refrigerant shortage signal is received from the refrigerant quantity sensor 25 or not. The case is not limited. The control unit 90 measures the state of the refrigeration cycle, calculates the refrigeration capacity using the measurement values of the temperature sensor and the pressure sensor (not shown), and if the calculated refrigeration capacity is reduced, the refrigerant amount is insufficient You may judge. Even if the air conditioner 1 is provided with a plurality of temperature sensors for measuring temperatures including the outside air temperature and the refrigerant temperature, and a plurality of pressure sensors for measuring the refrigerant pressure including the discharge pressure and the suction pressure of the compressor 11 Good. In this case, the control unit 90 may determine the refrigerant shortage from the measurement values of various sensors.
　また、図１～図３に示した構成例では、２つの第２中継器５０ａおよび５０ｂ毎に２台の負荷側ユニットが接続される場合を示しているが、第２中継器５０ａおよび５０ｂに接続される負荷側ユニットの台数は２台に限らない。複数の第２中継器のうち、１台の第２中継器に１台の負荷側ユニットが接続され、他の第２中継器に負荷側ユニットが１台も接続されていなくてもよい。 Further, in the configuration example shown in FIG. 1 to FIG. 3, there is shown a case where two load side units are connected to every two second relays 50a and 50b, but in the second relays 50a and 50b The number of connected load units is not limited to two. Among the plurality of second relays, one load-side unit may be connected to one second relay, and no load-side unit may be connected to another second relay.
　図６は、図１に示した空気調和装置が全冷房運転の場合における第２中継器の冷媒の流れを示す図である。空気調和装置１が全冷房運転を行う場合の冷媒の流れを、図２および図６を参照して説明する。図６では、冷媒が流れる方向を矢印で示す。負荷側ユニット７０ａ～７０ｄの運転状態の全てが冷房運転である。 FIG. 6 is a diagram showing the flow of refrigerant in the second relay when the air conditioning apparatus shown in FIG. 1 is in the cooling only operation. The flow of the refrigerant when the air conditioning apparatus 1 performs the cooling only operation will be described with reference to FIGS. 2 and 6. In FIG. 6, the direction in which the refrigerant flows is indicated by an arrow. All of the operating states of the load side units 70a to 70d are cooling operation.
　図２に示す圧縮機１１は、アキュムレータ１４から吸入する冷媒を圧縮し、高温高圧のガス冷媒を吐出する。圧縮機１１から吐出されたガス冷媒は、流路切替弁１２を通って熱源側熱交換器１３に流入する。熱源側熱交換器１３において、ガス冷媒は、外気と熱交換を行って凝縮され、液化する。液化した冷媒は、第４の逆止弁１９および高圧管２３を通って第１中継器３０に流入する。第１中継器３０において、液冷媒は、気液分離装置３２、第１の熱交換部３３、および第１の流量制御装置３５の順に流通する。 The compressor 11 shown in FIG. 2 compresses the refrigerant drawn from the accumulator 14 and discharges a high temperature and high pressure gas refrigerant. The gas refrigerant discharged from the compressor 11 flows into the heat source side heat exchanger 13 through the flow path switching valve 12. In the heat source side heat exchanger 13, the gas refrigerant exchanges heat with the outside air, is condensed, and is liquefied. The liquefied refrigerant flows into the first relay 30 through the fourth check valve 19 and the high pressure pipe 23. In the first relay 30, the liquid refrigerant flows in the order of the gas-liquid separation device 32, the first heat exchange unit 33, and the first flow control device 35.
　液冷媒は、液管４１を介して、図２に示した第１中継器３０から流出すると、図６に示す液管４１ａおよび４１ｂに分流する。液管４１ａを流れる液冷媒は第２中継器５０ａに流入する。液管４１ｂを流れる液冷媒は第２中継器５０ｂに流入する。第２中継器５０ａに流入した液冷媒は、第３の熱交換部５２を流通した後、接続ポート８５ｃおよび８５ａに分流する。一方、第２中継器５０ｂに流入した液冷媒は、第３の熱交換部５２を流通した後、接続ポート８５ｄおよび８５ｂに分流する。 When the liquid refrigerant flows out of the first relay 30 shown in FIG. 2 through the liquid pipe 41, it flows into the liquid pipes 41a and 41b shown in FIG. The liquid refrigerant flowing through the liquid pipe 41a flows into the second relay 50a. The liquid refrigerant flowing through the liquid pipe 41b flows into the second relay 50b. After flowing through the third heat exchange section 52, the liquid refrigerant flowing into the second relay 50a is branched to the connection ports 85c and 85a. On the other hand, the liquid refrigerant that has flowed into the second relay 50 b flows through the third heat exchange unit 52 and then is branched to the connection ports 85 d and 85 b.
　接続ポート８５ｃを流通する液冷媒は、液枝管７６ｃを流通して、負荷側ユニット７０ｃに流入する。接続ポート８５ａを流通する液冷媒は、液枝管７６ａを流通して、負荷側ユニット７０ａに流入する。接続ポート８５ｄを流通する液冷媒は、液枝管７６ｄを流通して、負荷側ユニット７０ｄに流入する。接続ポート８５ｂを流通する液冷媒は、液枝管７６ｂを流通して、負荷側ユニット７０ｂに流入する。 The liquid refrigerant flowing through the connection port 85c flows through the liquid branch pipe 76c and flows into the load side unit 70c. The liquid refrigerant flowing through the connection port 85a flows through the liquid branch pipe 76a and flows into the load side unit 70a. The liquid refrigerant flowing through the connection port 85d flows through the liquid branch pipe 76d and flows into the load side unit 70d. The liquid refrigerant flowing through the connection port 85b flows through the liquid branch pipe 76b and flows into the load side unit 70b.
　負荷側ユニット７０ｃに流入した冷媒は、負荷側流量制御装置７２ｃで減圧された後、負荷側熱交換器７１ｃにおいて、空調対象空間の空気と熱交換を行って蒸発し、ガス化する。ガス化した冷媒は、ガス枝管７５ｃを流通して、第２中継器５０ａの接続ポート８１ｃに流入する。なお、負荷側ユニット７０ａ、７０ｂおよび７０ｄにおける冷媒の流れは、負荷側ユニット７０ｃと同様であるため、その説明を省略する。 The refrigerant flowing into the load side unit 70c is decompressed by the load side flow control device 72c, and then exchanges heat with the air of the air conditioning target space in the load side heat exchanger 71c to evaporate and gasify. The gasified refrigerant flows through the gas branch pipe 75c and flows into the connection port 81c of the second relay 50a. The flow of the refrigerant in the load side units 70a, 70b and 70d is the same as that of the load side unit 70c, so the description thereof will be omitted.
　第２中継器５０ａにおいて、接続ポート８１ｃを流通するガス冷媒と接続ポート８１ａを流通するガス冷媒とが低圧ガス管４２ａで合流する。また、第２中継器５０ｂにおいて、接続ポート８１ｄを流通するガス冷媒と接続ポート８１ｂを流通するガス冷媒とが低圧ガス管４２ｂで合流する。低圧ガス管４２ａを流通するガス冷媒と低圧ガス管４２ｂを流通するガス冷媒とが低圧ガス管４２に合流した後、図２に示した第１中継器３０に流入する。 In the second relay unit 50a, the gas refrigerant flowing through the connection port 81c and the gas refrigerant flowing through the connection port 81a merge at the low pressure gas pipe 42a. Further, in the second relay 50b, the gas refrigerant flowing through the connection port 81d and the gas refrigerant flowing through the connection port 81b merge at the low pressure gas pipe 42b. The gas refrigerant flowing through the low pressure gas pipe 42a and the gas refrigerant flowing through the low pressure gas pipe 42b join the low pressure gas pipe 42, and then flow into the first relay 30 shown in FIG.
　図２に示す第１中継器３０に流入したガス冷媒は、低圧ガス管４２および低圧管２２を流通して熱源機１０に流入する。熱源機１０に流入したガス冷媒は、第１の逆止弁１６および流路切替弁１２を順に流通してアキュムレータ１４に流入する。 The gas refrigerant that has flowed into the first relay 30 shown in FIG. 2 flows through the low pressure gas pipe 42 and the low pressure pipe 22 and flows into the heat source unit 10. The gas refrigerant that has flowed into the heat source unit 10 flows through the first check valve 16 and the flow path switching valve 12 in order and flows into the accumulator 14.
　このようにして、圧縮機１１から吐出された冷媒は、熱源機１０で生成された熱を負荷側ユニット７０ａ～７０ｄに運び、負荷側ユニット７０ａ～７０ｄの空調対象空間を冷却した後、熱源機１０のアキュムレータ１４に戻る。 Thus, the refrigerant discharged from the compressor 11 carries the heat generated by the heat source unit 10 to the load side units 70a to 70d and cools the air conditioning target space of the load side units 70a to 70d. It returns to the accumulator 14 of ten.
　次に、空気調和装置１が全暖房運転を行う場合の冷媒の流れを、図２および図７を参照して説明する。図７は、図１に示した空気調和装置が全暖房運転を行う場合における第２中継器の冷媒の流れを示す図である。図７では、冷媒が流れる方向を矢印で示す。高圧ガス冷媒が流れる冷媒配管を太く表示している。負荷側ユニット７０ａ～７０ｄの運転状態の全てが暖房運転である。 Next, the flow of the refrigerant when the air conditioning apparatus 1 performs the heating only operation will be described with reference to FIGS. 2 and 7. FIG. 7 is a diagram showing the flow of the refrigerant in the second relay when the air conditioning apparatus shown in FIG. 1 performs the heating only operation. In FIG. 7, the direction in which the refrigerant flows is indicated by an arrow. The refrigerant piping through which the high pressure gas refrigerant flows is displayed thick. All of the operating states of the load side units 70a to 70d are heating operations.
　図２に示す圧縮機１１から吐出された高温高圧のガス冷媒は、流路切替弁１２および第３の逆止弁１８を流通した後、低圧管２２を介して第１中継器３０に流入する。第１中継器３０において、ガス冷媒は、気液分離装置３２および高圧ガス管４３を流通した後、図７に示す高圧ガス管４３ａおよび４３ｂに分流する。 The high temperature / high pressure gas refrigerant discharged from the compressor 11 shown in FIG. 2 flows through the flow path switching valve 12 and the third check valve 18 and then flows into the first relay 30 via the low pressure pipe 22. . In the first relay 30, after flowing through the gas-liquid separation device 32 and the high pressure gas pipe 43, the gas refrigerant is diverted to the high pressure gas pipes 43a and 43b shown in FIG.
　高圧ガス管４３ａを流れるガス冷媒は第２中継器５０ａに流入する。高圧ガス管４３ｂを流れるガス冷媒は第２中継器５０ｂに流入する。第２中継器５０ａに流入したガス冷媒は、接続ポート８１ｃおよび８１ａに分流する。一方、第２中継器５０ｂに流入したガス冷媒は、接続ポート８１ｄおよび８１ｂに分流する。 The gas refrigerant flowing through the high pressure gas pipe 43a flows into the second relay 50a. The gas refrigerant flowing through the high pressure gas pipe 43b flows into the second relay 50b. The gas refrigerant that has flowed into the second relay 50a is branched to the connection ports 81c and 81a. On the other hand, the gas refrigerant that has flowed into the second relay 50b is branched to the connection ports 81d and 81b.
　接続ポート８１ｃを流通するガス冷媒は、ガス枝管７５ｃを流通して、負荷側ユニット７０ｃに流入する。接続ポート８１ａを流通するガス冷媒は、ガス枝管７５ａを流通して、負荷側ユニット７０ａに流入する。接続ポート８１ｄを流通するガス冷媒は、ガス枝管７５ｄを流通して、負荷側ユニット７０ｄに流入する。接続ポート８１ｂを流通するガス冷媒は、ガス枝管７５ｂを流通して、負荷側ユニット７０ｂに流入する。 The gas refrigerant flowing through the connection port 81c flows through the gas branch pipe 75c and flows into the load side unit 70c. The gas refrigerant flowing through the connection port 81a flows through the gas branch pipe 75a and flows into the load side unit 70a. The gas refrigerant flowing through the connection port 81 d flows through the gas branch pipe 75 d and flows into the load side unit 70 d. The gas refrigerant flowing through the connection port 81b flows through the gas branch pipe 75b and flows into the load side unit 70b.
　負荷側ユニット７０ｃに流入した冷媒は、負荷側熱交換器７１ｃにおいて、空調対象空間の空気と熱交換を行って凝縮され、液化する。液化した冷媒は、負荷側流量制御装置７２ｃで減圧された後、液枝管７６ｃを流通して、第２中継器５０ａの接続ポート８５ｃに流入する。なお、負荷側ユニット７０ａ、７０ｂおよび７０ｄにおける冷媒の流れは、負荷側ユニット７０ｃと同様であるため、その説明を省略する。 The refrigerant flowing into the load side unit 70c exchanges heat with the air in the air conditioning target space in the load side heat exchanger 71c, is condensed, and is liquefied. The liquefied refrigerant is reduced in pressure by the load-side flow control device 72c, and then flows through the liquid branch pipe 76c to flow into the connection port 85c of the second relay 50a. The flow of the refrigerant in the load side units 70a, 70b and 70d is the same as that of the load side unit 70c, so the description thereof will be omitted.
　第２中継器５０ａにおいて、接続ポート８５ｃを流通する冷媒と接続ポート８５ａを流通する冷媒とが、液管５１を経由して液管４１ａに流入する。また、第２中継器５０ｂにおいては、接続ポート８５ｄを流通する冷媒と接続ポート８５ｂを流通する冷媒とが、液管５１を経由して液管４１ｂに流入する。液管４１ａを流通する冷媒と液管４１ｂを流通する冷媒とが液管４１に合流した後、図２に示した第１中継器３０に流入する。 In the second relay unit 50a, the refrigerant flowing through the connection port 85c and the refrigerant flowing through the connection port 85a flow into the liquid pipe 41a via the liquid pipe 51. In the second relay 50b, the refrigerant flowing through the connection port 85d and the refrigerant flowing through the connection port 85b flow into the liquid pipe 41b via the liquid pipe 51. After the refrigerant flowing through the liquid pipe 41a and the refrigerant flowing through the liquid pipe 41b join the liquid pipe 41, the refrigerant flows into the first relay 30 shown in FIG.
　図２に示す第１中継器３０に流入した冷媒は、第２の熱交換部３４、第２の流量制御装置３６および第１の熱交換部３３を順に経由して低圧管２２を流通して熱源機１０に流入する。熱源機１０に流入した冷媒は、第２の逆止弁１７を流通した後、熱源側熱交換器１３に流入する。熱源側熱交換器１３において、液冷媒は、外気と熱交換を行って蒸発し、ガス化する。ガス化した冷媒は、流路切替弁１２を流通した後、アキュムレータ１４に流入する。 The refrigerant flowing into the first relay 30 shown in FIG. 2 flows through the low pressure pipe 22 through the second heat exchange unit 34, the second flow control device 36 and the first heat exchange unit 33 in this order. It flows into the heat source unit 10. The refrigerant that has flowed into the heat source unit 10 flows into the heat source side heat exchanger 13 after flowing through the second check valve 17. In the heat source side heat exchanger 13, the liquid refrigerant exchanges heat with the outside air, evaporates, and gasifies. The gasified refrigerant flows into the accumulator 14 after flowing through the flow path switching valve 12.
　このようにして、圧縮機１１から吐出された冷媒は、熱源機１０で生成された熱を負荷側ユニット７０ａ～７０ｄに運び、負荷側ユニット７０ａ～７０ｄの空調対象空間を温めた後、熱源機１０のアキュムレータ１４に戻る。 In this manner, the refrigerant discharged from the compressor 11 carries the heat generated by the heat source unit 10 to the load side units 70a to 70d and warms the air conditioning target space of the load side units 70a to 70d. It returns to the accumulator 14 of ten.
　次に、空気調和装置１が冷房主体運転を行う場合の冷媒の流れを説明する。図８は、図１に示した空気調和装置が冷房主体運転を行う場合における第２中継器の冷媒の流れを示す図である。図８では、冷媒が流れる方向を矢印で示す。高圧ガス冷媒が流れる冷媒配管を太く表示している。図８では、負荷側ユニット７０ａ～７０ｄのうち、負荷側ユニット７０ｃが暖房運転である。負荷側ユニット７０ａおよび７０ｄが冷房運転である。負荷側ユニット７０ｂが停止している。冷房主体運転は、全冷房運転における制御が一部異なる。ここでは、空気調和装置１が全冷房運転を行う場合と異なる点を説明する。 Next, the flow of the refrigerant when the air conditioning apparatus 1 performs the cooling main operation will be described. FIG. 8 is a diagram showing the flow of the refrigerant in the second relay when the air conditioning apparatus shown in FIG. 1 performs the cooling main operation. In FIG. 8, the direction in which the refrigerant flows is indicated by an arrow. The refrigerant piping through which the high pressure gas refrigerant flows is displayed thick. In FIG. 8, among the load units 70a to 70d, the load unit 70c is in the heating operation. The load side units 70a and 70d are in the cooling operation. The load side unit 70 b is stopped. In the cooling main operation, control in the all cooling operation is partially different. Here, points different from the case where the air conditioning apparatus 1 performs the cooling only operation will be described.
　運転モードが全冷房運転の場合と同様にして、液冷媒が、図２に示す熱源機１０から高圧管を流通して第１中継器３０に流入する。第１中継器３０に流入した液冷媒は、気液分離装置３２において、高圧ガス冷媒と液冷媒とに分離する。高圧ガス冷媒は、高圧ガス管４３を流通した後、高圧ガス管４３ａおよび４３ｂに分流する。一方、気液分離装置３２で分離された液冷媒は、全冷房運転の場合と同様にして、液管４１を流通した後、液管４１ａおよび４１ｂに分流する。 The liquid refrigerant flows from the heat source unit 10 shown in FIG. 2 through the high pressure pipe and flows into the first relay 30 in the same manner as the case where the operation mode is the cooling only operation. The liquid refrigerant that has flowed into the first relay 30 is separated into high-pressure gas refrigerant and liquid refrigerant in the gas-liquid separator 32. After flowing through the high pressure gas pipe 43, the high pressure gas refrigerant is diverted to the high pressure gas pipes 43a and 43b. On the other hand, the liquid refrigerant separated by the gas-liquid separation device 32 flows through the liquid pipe 41 in the same manner as in the case of the cooling only operation, and then is branched to the liquid pipes 41a and 41b.
　液管４１ａを流通する液冷媒は、接続ポート８５ａおよび液枝管７６ａを経由して負荷側ユニット７０ａに流入する。負荷側ユニット７０ａにおいて、冷媒は、運転モードが全冷房運転の場合と同様にして、負荷側流量制御装置７２ａで減圧された後、負荷側熱交換器７１ａで空調対象空間の空気と熱交換を行って蒸発し、ガス化する。ガス化した冷媒は、ガス枝管７５ａを流通して、第２中継器５０ａの接続ポート８１ａに流入する。ガス冷媒は、接続ポート８１ａから、低圧ガス管４２ａ、低圧ガス管４２、第１中継器３０および低圧管２２を順に流通して、熱源機１０に戻る。なお、負荷側ユニット７０ｄにおける冷媒の流れは、負荷側ユニット７０ａと同様であるため、その説明を省略する。 The liquid refrigerant flowing through the liquid pipe 41a flows into the load side unit 70a via the connection port 85a and the liquid branch pipe 76a. In the load side unit 70a, the refrigerant is reduced in pressure by the load side flow control device 72a in the same manner as in the case of the cooling only operation mode, and then exchanges heat with the air in the air conditioned space by the load side heat exchanger 71a. Go and evaporate and gasify. The gasified refrigerant flows through the gas branch pipe 75a and flows into the connection port 81a of the second relay 50a. The gas refrigerant flows from the connection port 81 a to the low pressure gas pipe 42 a, the low pressure gas pipe 42, the first relay 30, and the low pressure pipe 22 in this order, and returns to the heat source unit 10. In addition, since the flow of the refrigerant | coolant in the load side unit 70d is the same as that of the load side unit 70a, the description is abbreviate | omitted.
　一方、高圧ガス管４３ａを流通するガス冷媒は、運転モードが全暖房運転の場合と同様にして、接続ポート８１ｃおよびガス枝管７５ｃを経由して負荷側ユニット７０ｃに流入する。負荷側ユニット７０ｃにおいて、冷媒は、運転モードが全暖房運転の場合と同様にして、負荷側熱交換器７１ｃで空調対象空間の空気と熱交換を行って凝縮され、液化する。液化した冷媒は、負荷側流量制御装置７２ｃで減圧された後、液枝管７６ｃを流通して、第２中継器５０ａの接続ポート８５ｃに流入する。液化した冷媒は、液管５１に流入し、負荷側ユニット７０ｃの冷房運転で利用される。 On the other hand, the gas refrigerant flowing through the high pressure gas pipe 43a flows into the load side unit 70c via the connection port 81c and the gas branch pipe 75c in the same manner as in the case of the heating only operation mode. In the load side unit 70c, the refrigerant exchanges heat with the air in the space to be air-conditioned in the load side heat exchanger 71c, condenses and liquefies, as in the case of the heating only operation mode. The liquefied refrigerant is reduced in pressure by the load-side flow control device 72c, and then flows through the liquid branch pipe 76c to flow into the connection port 85c of the second relay 50a. The liquefied refrigerant flows into the liquid pipe 51 and is used in the cooling operation of the load side unit 70c.
　このようにして、冷房主体運転では、負荷側ユニット７０ａおよび７０ｄの空調対象空間が冷却され、負荷側ユニット７０ｃの空調対象空間が温められる。 Thus, in the cooling main operation, the air conditioning target space of the load side units 70a and 70d is cooled, and the air conditioning target space of the load side unit 70c is warmed.
　図８に示す第２中継器５０ａにおいては、第１中継器３０から高圧ガス管４３および高圧ガス管４３ａを流通するガス冷媒は、負荷側ユニット７０ｃに流れ込む。一方、第２中継器５０ｂでは、負荷側ユニット７０ｂおよび７０ｄがいずれも暖房運転をしていなくても、高圧のガス冷媒が第１中継器３０から高圧ガス管４３および高圧ガス管４３ｂを流通して、第２中継器５０ｂに供給される。しかし、高圧ガス管４３ｂに接続される接続ポート８１ｂ～８４ｂおよび８１ｄ～８４ｄの高圧弁１２１が全て閉状態なので、第１中継器３０と第２中継器５０ｂとの間にガス冷媒が滞留する。滞留するガス冷媒は、周囲の空気に熱が奪われ、温度が低下し、滞留してしまう。 In the second relay unit 50a shown in FIG. 8, the gas refrigerant flowing from the first relay unit 30 through the high pressure gas pipe 43 and the high pressure gas pipe 43a flows into the load side unit 70c. On the other hand, in the second relay 50b, high-pressure gas refrigerant flows from the first relay 30 through the high-pressure gas pipe 43 and the high-pressure gas pipe 43b even when the load side units 70b and 70d do not perform heating operation. Is supplied to the second repeater 50b. However, since the high pressure valves 121 of the connection ports 81b to 84b and 81d to 84d connected to the high pressure gas pipe 43b are all closed, the gas refrigerant stagnates between the first relay 30 and the second relay 50b. The gas refrigerant that has stagnated is deprived of heat by the surrounding air, the temperature drops, and it stagnates.
　第１中継器３０と第２中継器５０ｂとの間にガス冷媒が滞留する場合を、図８を参照して冷房主体運転の場合で説明したが、冷媒が滞留する運転状態はこの場合に限らない。熱源機１０から高圧のガス冷媒を第１中継器３０側に供給する暖房流路に熱源機１０が設定された場合、第２中継器５０ａおよび５０ｂにおいて、接続される負荷側ユニットが１台も運転していない第２中継器と第１中継器３０との間にガス冷媒が滞留する。 Although the case where the gas refrigerant stagnates between the first relay 30 and the second relay 50b has been described in the case of the cooling main operation with reference to FIG. 8, the operation state in which the refrigerant stagnates is limited to this case. Absent. When the heat source unit 10 is set in the heating flow path for supplying high-pressure gas refrigerant from the heat source unit 10 to the first relay unit 30, one load side unit is connected to the second relay units 50a and 50b. The gas refrigerant stagnates between the second relay not operating and the first relay 30.
　熱源機１０に暖房流路が設定された場合に、冷媒が滞留する別の例を説明する。第１中継器３０に図に示さない負荷側ユニットが接続されているものとする。第１中継器３０に接続される負荷側ユニットが暖房運転を行っているが、第２中継器５０ａおよび５０ｂに接続される負荷側ユニットの全て運転していないとする。この場合、第１中継器３０と第２中継器５０ａおよび５０ｂとの間の高圧ガス管４３、４３ａおよび４３ｂに冷媒が滞留することになる。第１中継器３０に接続される第２中継器が１台の場合でも、第１中継器３０と第２中継器５０ａとの間に冷媒が滞留する。 When the heating flow path is set to the heat source unit 10, another example in which the refrigerant stagnates will be described. It is assumed that a load side unit (not shown) is connected to the first repeater 30. It is assumed that the load side unit connected to the first relay 30 is performing the heating operation, but not all the load side units connected to the second relays 50a and 50b are operating. In this case, the refrigerant stagnates in the high pressure gas pipes 43, 43a and 43b between the first relay 30 and the second relays 50a and 50b. Even when there is only one second relay connected to the first relay 30, the refrigerant stagnates between the first relay 30 and the second relay 50a.
　次に、冷媒の滞留を熱源機１０に戻す動作の手順を説明する。図９は、図５に示した制御部が実行する動作手順を示すフローチャートである。 Next, the procedure of the operation of returning the stagnation of the refrigerant to the heat source unit 10 will be described. FIG. 9 is a flowchart showing an operation procedure performed by the control unit shown in FIG.
　制御部９０は、冷媒量センサ２５が冷媒不足を検知したか否かを判定する（ステップＳ１０１）。制御部９０は、冷媒量センサ２５から冷媒不足信号を受信すると、冷媒不足と判定し、冷媒回収処理の制御対象となる接続ポートを探す（ステップＳ１０２）。 The control unit 90 determines whether the refrigerant amount sensor 25 has detected a refrigerant shortage (step S101). When receiving the refrigerant shortage signal from the refrigerant amount sensor 25, the control unit 90 determines that the refrigerant is shortage, and searches for a connection port to be controlled in the refrigerant recovery process (step S102).
　第２中継器５０ａおよび５０ｂの各第２中継器において、１台でも負荷側ユニットが暖房運転を行っていれば、第１中継器３０と第２中継器５０ａおよび５０ｂとの間で、冷媒は滞留しない。 In each of the second relays 50a and 50b, if at least one load-side unit is performing a heating operation, the refrigerant is between the first relay 30 and the second relays 50a and 50b. It does not stay.
　制御部９０は、暖房運転を行っている負荷側ユニットと接続される接続ポートを有する第２中継器を、冷媒回収処理の制御対象から除外する。制御部９０は、残った第２中継器において、高圧ガス管に接続される複数の接続ポートから制御対象の接続ポートを選択する。制御対象の条件に合う接続ポートは、負荷側ユニットが接続されていない接続ポートと、負荷側ユニットが接続されていても負荷側ユニットが運転していない接続ポートとのうち、いずれかである。 Control part 90 excludes the 2nd relay which has a connection port connected with the load side unit which is performing heating operation from control object of refrigerant recovery processing. The control unit 90 selects a connection port to be controlled from among a plurality of connection ports connected to the high pressure gas pipe in the remaining second repeater. The connection port meeting the condition to be controlled is either a connection port to which the load-side unit is not connected or a connection port to which the load-side unit is not operating even if the load-side unit is connected.
　制御部９０は、条件に合う接続ポートを、冷媒回収処理の制御対象として選択する（ステップＳ１０３）。選択される接続ポートを、接続ポートｋで表す。例えば、第１分岐ユニット６１ａから接続ポートｋが選択される場合、ｋは８１ａ～８４ａのいずれかである。ステップＳ１０３において、制御部９０は、条件に合う接続ポートが複数ある場合には、設定された優先順位にしたがって、１つの接続ポートｋを選択する。例えば、負荷側ユニットが接続されていない接続ポートの優先順位は、負荷側ユニットが接続されている接続ポートの優先順位よりも高く設定されている。 The control unit 90 selects a connection port meeting the conditions as a control target of the refrigerant recovery process (step S103). The connection port to be selected is represented by a connection port k. For example, when the connection port k is selected from the first branch unit 61a, k is any one of 81a to 84a. In step S103, when there are a plurality of connection ports meeting the conditions, the control unit 90 selects one connection port k in accordance with the set priority. For example, the priority of the connection port to which the load-side unit is not connected is set higher than the priority of the connection port to which the load-side unit is connected.
　続いて、制御部９０は、選択した接続ポートｋの高圧弁１２１を閉状態から開状態に切り替え、低圧弁１２２を閉状態から開状態に切り替える（ステップＳ１０４）。これにより、接続ポートｋにおいて、高圧ガス管から冷媒が高圧弁１２１および低圧弁１２２を流通して低圧ガス管に流入する。制御部９０は、低圧弁１２２を開いたときから時間を計測し、計測した時間が設定時間を経過したか否かを判定する（ステップＳ１０５）。設定時間が経過すると、制御部９０は、接続ポートｋの高圧弁１２１を開状態から閉状態に戻し、低圧弁１２２を開状態から閉状態に戻す（ステップＳ１０６）。 Subsequently, the control unit 90 switches the high pressure valve 121 of the selected connection port k from the closed state to the open state, and switches the low pressure valve 122 from the closed state to the open state (step S104). Thus, at the connection port k, the refrigerant flows from the high pressure gas pipe to the high pressure valve 121 and the low pressure valve 122 to flow into the low pressure gas pipe. The control unit 90 measures the time from when the low pressure valve 122 is opened, and determines whether the measured time has passed the set time (step S105). When the set time has elapsed, the control unit 90 returns the high pressure valve 121 of the connection port k from the open state to the closed state, and returns the low pressure valve 122 from the open state to the closed state (step S106).
　図８に示した構成例では、ステップＳ１０２の処理で条件に合う接続ポートｋは、接続ポート８２ｄ～８４ｄおよび接続ポート８１ｂ～８４ｂである。制御部９０が、これらの接続ポートのうち、いずれかの接続ポートを１つ選択し、図９に示すステップＳ１０４およびＳ１０５の処理を行う。第１中継器３０と第２中継器５０ｂとの間に滞留する冷媒が、選択された接続ポートｋの高圧弁１２１および低圧弁１２２を流通した後、低圧ガス管４２ｂを経由して熱源機１０に戻る。 In the configuration example shown in FIG. 8, the connection ports k meeting the conditions in the process of step S102 are the connection ports 82d to 84d and the connection ports 81b to 84b. The control unit 90 selects one of these connection ports, and performs the processes of steps S104 and S105 shown in FIG. The refrigerant accumulated between the first relay 30 and the second relay 50b flows through the high pressure valve 121 and the low pressure valve 122 of the selected connection port k, and then the heat source unit 10 via the low pressure gas pipe 42b. Return to
　図８に示した構成例の場合、接続ポート８２ｄ～８４ｄおよび８１ｂ～８４ｂのうち、接続ポート８１ｂを選択することが望ましい。候補となった接続ポート８２ｄ～８４ｄおよび８１ｂ～８４ｂのうち、接続ポート８１ｂは、第１中継器３０を起点とする高圧ガス管４３の距離および高圧ガス管４３から分岐する高圧ガス管４３ｂに沿った距離が最も遠い位置にある。この場合、第１中継器３０と第２中継器５０ｂの間に滞留する冷媒を、できるだけ残らず低圧ガス管４２ｂに回収することができる。 In the case of the configuration example shown in FIG. 8, it is desirable to select the connection port 81b among the connection ports 82d to 84d and 81b to 84b. Among the connection ports 82d to 84d and 81b to 84b which have become candidates, the connection port 81b is provided along the distance of the high pressure gas pipe 43 starting from the first relay 30 and the high pressure gas pipe 43b branched from the high pressure gas pipe 43. Distance is the farthest position. In this case, the refrigerant remaining between the first relay 30 and the second relay 50b can be recovered to the low pressure gas pipe 42b with as much as possible.
　また、制御部９０は、接続ポート８１ｂのように、選択した接続ポートｋに負荷側ユニットが接続されている場合、ステップＳ１０３とステップＳ１０４との間で、負荷側流量制御装置７２ｂを開閉する制御を行ってもよい。以下に、その理由を説明する。ここでは、選択された接続ポートｋが接続ポート８１ｂの場合で説明する。 Further, when the load side unit is connected to the selected connection port k, as in the connection port 81b, the control unit 90 performs control to open and close the load side flow control device 72b between step S103 and step S104. You may The reason will be described below. Here, the case where the selected connection port k is the connection port 81b will be described.
　負荷側ユニット７０ｂは運転を停止しているため、ガス枝管７５ｂ内の冷媒が周囲の空気の温度で冷却され、冷媒圧力が低下している。また、低圧ガス管４２ｂの冷媒圧力と高圧ガス管４３ａの冷媒圧力との圧力差が大きい状態である。この状態で、高圧弁１２１および低圧弁１２２が開くと、高圧のガス冷媒が一気にガス枝管７５ｂ内に流れ込む。このとき、ガス枝管７５ｂおよび負荷側熱交換器７１ｂに大きな圧力負荷がかかってしまう場合がある。また、高圧のガス冷媒が高圧ガス管４３ｂからガス枝管７５ａおよび低圧ガス管４２ｂに勢いよく流れ込むことで、破裂音のような音が発生することがある。 Since the load side unit 70b has stopped operation, the refrigerant in the gas branch pipe 75b is cooled at the temperature of the surrounding air, and the refrigerant pressure is reduced. Further, the pressure difference between the refrigerant pressure of the low pressure gas pipe 42 b and the refrigerant pressure of the high pressure gas pipe 43 a is large. In this state, when the high pressure valve 121 and the low pressure valve 122 are opened, the high pressure gas refrigerant flows into the gas branch pipe 75b at a stretch. At this time, a large pressure load may be applied to the gas branch pipe 75b and the load side heat exchanger 71b. In addition, the high pressure gas refrigerant may vigorously flow from the high pressure gas pipe 43b to the gas branch pipe 75a and the low pressure gas pipe 42b to generate a sound like a bursting sound.
　図８に示す場合、負荷側ユニット７０ｄが冷房運転を行っているので、液枝管７６ｂには、高圧の液冷媒が流れ込んでいる。そこで、ステップＳ１０４の処理の前に、制御部９０は、ステップＳ１０３で接続ポート８１ｂを選択すると、ステップＳ１０４の前に負荷側流量制御装置７２ｂを開いて、ガス枝管７５ｂ内の冷媒圧力を高圧ガス管４３ｂの冷媒圧力の１／２程度まで上昇させる。その後、制御部９０は、負荷側流量制御装置７２ｂを閉じ、ステップＳ１０４の処理に進む。 In the case shown in FIG. 8, since the load side unit 70d is performing the cooling operation, the high-pressure liquid refrigerant flows into the liquid branch pipe 76b. Therefore, when the connection port 81b is selected in step S103 before the process of step S104, the load side flow control device 72b is opened before step S104, and the refrigerant pressure in the gas branch pipe 75b is increased. The pressure is raised to about 1/2 of the refrigerant pressure of the gas pipe 43b. Thereafter, the control unit 90 closes the load-side flow control device 72b, and proceeds to the process of step S104.
　このようにして、制御部９０がステップＳ１０４の前に負荷側流量制御装置７２ｂを開閉制御することで、低圧ガス管４２ｂの冷媒圧力と高圧ガス管４３ｂの冷媒圧力との差圧が小さくなる。そして、高圧弁１２１および低圧弁１２２が開いたとき、冷媒が高圧ガス管４３ｂから低圧ガス管４２ｂに流れ込む勢いが抑制される。その結果、ガス枝管７５ｂおよび負荷側熱交換器７１ｂに大きな圧力負荷がかかることが抑制される。また、高圧のガス冷媒が低圧ガス管４２ｂに流れ込むときに発生する音の大きさが低減する。 In this manner, by opening and closing the load side flow control device 72b before the step S104, the control unit 90 reduces the differential pressure between the refrigerant pressure of the low pressure gas pipe 42b and the refrigerant pressure of the high pressure gas pipe 43b. When the high pressure valve 121 and the low pressure valve 122 are opened, the force of the refrigerant flowing from the high pressure gas pipe 43b into the low pressure gas pipe 42b is suppressed. As a result, application of a large pressure load to the gas branch pipe 75b and the load side heat exchanger 71b is suppressed. Further, the magnitude of the sound generated when the high pressure gas refrigerant flows into the low pressure gas pipe 42b is reduced.
　なお、本実施の形態１では、図９を参照して、冷媒不足が検知されたとき、制御部９０が冷媒回収処理を行う場合で説明したが、冷媒回収処理は冷媒不足が検知された場合に限らない。空気調和装置１が図８に示した運転状態では、２台の第２中継器５０ａおよび５０ｂのうち、一方の第２中継器５０ａに接続された負荷側ユニット７０ｃが暖房運転を行い、他方の第２中継器５０ｂには暖房運転を行う負荷側ユニットが１台もない。このことから、制御部９０は、複数の第２中継器のうち、１台の第２中継器に接続される負荷側ユニットが暖房運転を行い、他の第２中継器では、暖房運転している負荷側ユニットがない状態を認識すると、他の第２中継器で冷媒が滞留していると判断してもよい。この場合、制御部９０は、一定時間毎に他の第２中継器に対して、図９に示した手順にしたがって冷媒回収処理を行ってもよい。 In the first embodiment, the case where the controller 90 performs the refrigerant recovery process when the refrigerant insufficiency is detected is described with reference to FIG. 9, but the refrigerant recovery process detects the refrigerant insufficiency. Not limited to. When the air conditioner 1 is in the operating state shown in FIG. 8, the load-side unit 70c connected to one second relay 50a of the two second relays 50a and 50b performs a heating operation, and the other unit The second relay 50b has no load side unit that performs heating operation. From this, the control unit 90 performs the heating operation on the load side unit connected to one second relay among the plurality of second relays, and performs the heating operation on the other second relays. If it is recognized that there is no load-side unit present, it may be determined that the refrigerant is stagnating in another second relay. In this case, the control unit 90 may perform the refrigerant recovery process on the other second relays according to the procedure shown in FIG. 9 every fixed time.
　また、図９を参照して、冷媒回収処理の対象となる運転状態として、１台の第２中継器に接続される負荷側ユニットが暖房運転を行い、他の第２中継器では、暖房運転している負荷側ユニットがない状態の場合を説明したが、この場合に限らない。例えば、図８に示した第２中継器５０ｂに接続される負荷側ユニット７０ｄが運転を停止している場合を考える。この場合、液管４１ｂを流通する冷媒が第１中継器３０に戻る際、負荷側ユニット７０ｄが冷房運転を行っている場合よりもスムーズに戻ることができない。第２中継器に接続される負荷側ユニットが１台も運転も行っていない場合に、制御部９０が図９に示した冷媒回収処理を行ってもよい。 Further, referring to FIG. 9, as an operation state to be subjected to the refrigerant recovery process, the load side unit connected to one second relay performs a heating operation, and the heating operation is performed in the other second relays. Although there has been described the case where there is no load side unit in operation, the present invention is not limited to this case. For example, consider a case where the load side unit 70d connected to the second relay 50b shown in FIG. 8 has stopped operation. In this case, when the refrigerant flowing through the liquid pipe 41b returns to the first relay 30, the load side unit 70d can not return more smoothly than in the case where the cooling operation is performed. When no load side unit connected to the second relay is operating, the control unit 90 may perform the refrigerant recovery process shown in FIG.
　本実施の形態１の空気調和装置１では、自器に接続されている負荷側ユニットが全て運転を停止している第２中継器があると、制御部９０は、その第２中継器において、高圧ガス管に接続される複数の接続ポートから１つの接続ポートを選択する。そして、制御部９０は、選択した接続ポートに設けられた高圧弁１２１および低圧弁１２２を開状態にして、高圧ガス管と低圧ガス管とを接続させる。 In the air conditioner 1 of the first embodiment, when there is a second relay in which all load-side units connected to its own unit have stopped operation, the control unit 90 controls the second relay in the following manner. One connection port is selected from a plurality of connection ports connected to the high pressure gas pipe. Then, the control unit 90 opens the high pressure valve 121 and the low pressure valve 122 provided in the selected connection port to connect the high pressure gas pipe and the low pressure gas pipe.
　本実施の形態１によれば、制御部９０は、冷媒の滞留が発生する運転状態になると、冷媒が滞留する第２中継器の接続ポートの弁を開放することで、滞留する冷媒を熱源機１０に回収する。滞留する冷媒が熱源機１０に戻り、冷媒不足による冷凍能力の低下を抑制することができる。また、冷媒の滞留が発生する運転状態に高圧ガス管と低圧ガス管とを接続する弁を開状態にするので、高圧ガス管と低圧ガス管とを接続するバイパス回路を常に開状態にする場合に比べて、冷凍能力の低下を抑制できる。 According to the first embodiment, when the control unit 90 is in an operating state where stagnation of refrigerant occurs, the control unit 90 opens the valve of the connection port of the second relay on which the refrigerant is stagnant, so that the stagnant refrigerant is a heat source machine Recover to 10. The stagnating refrigerant is returned to the heat source unit 10, and it is possible to suppress a decrease in refrigeration capacity due to a shortage of the refrigerant. In addition, when the valve connecting the high pressure gas pipe and the low pressure gas pipe is opened in the operating state where stagnation of refrigerant occurs, the bypass circuit connecting the high pressure gas pipe and the low pressure gas pipe is always opened As compared with the above, it is possible to suppress the decrease in the freezing capacity.
　また、滞留する冷媒の量と、高圧ガス管と低圧ガス管とをバイパスする回路が常に開状態である空気調和機の場合、冷凍能力の低下との関係で、第２中継器の台数、冷媒配管の長さおよび負荷側ユニットの容量を含む配管システム設計が制限される。これに対して、本実施の形態１では、冷媒不足のタイミングで、制御部９０は冷媒が滞留する接続ポートを特定し、特定した接続ポートにおける弁の開閉制御を行うことで、冷媒の回収と冷凍能力の低下とを図っている。冷媒量が足りている通常の運転状態では、冷凍能力の低下を防げるため、第２中継器の台数と配管長の制限が軽減する。そのため、本実施の形態１の空気調和装置１は、配管システムの設計の自由度が向上する。 Further, in the case of an air conditioner in which the amount of refrigerant staying and the circuit bypassing the high pressure gas pipe and the low pressure gas pipe are always in the open state, the number of second relays, refrigerants Piping system design is limited, including piping length and load side unit capacity. On the other hand, in the first embodiment, the control unit 90 specifies the connection port where the refrigerant stagnates at the timing of the refrigerant shortage, and performs opening / closing control of the valve in the specified connection port, thereby recovering the refrigerant. We are trying to reduce the refrigeration capacity. In a normal operating condition in which the amount of refrigerant is sufficient, a decrease in the refrigeration capacity can be prevented, so the restriction on the number of second relays and the pipe length is alleviated. Therefore, in the air conditioning apparatus 1 of the first embodiment, the degree of freedom in the design of the piping system is improved.
実施の形態２．
　本実施の形態２は、高圧ガス管側と接続される接続ポートの他の構成例に関するものである。本実施の形態２では、実施の形態１と同様な構成についての詳細な説明を省略する。 Second Embodiment
The second embodiment relates to another configuration example of the connection port connected to the high pressure gas pipe side. In the second embodiment, the detailed description of the same configuration as that of the first embodiment is omitted.
　図１０は、本発明の実施の形態２の空気調和装置における接続ポートの一構成例を示す図である。本実施の形態２では、接続ポート８１ａ～８４ａは互いに同様な構成のため、接続ポート８１ａの構成を説明する。接続ポート８５ａ～８８ａは実施の形態１と同様なため、その詳細な説明を省略する。 FIG. 10: is a figure which shows one structural example of the connection port in the air conditioning apparatus of Embodiment 2 of this invention. In the second embodiment, since the connection ports 81a to 84a have the same configuration, the configuration of the connection port 81a will be described. The connection ports 85a to 88a are the same as in the first embodiment, and thus the detailed description thereof is omitted.
　図１０に示すように、接続ポート８１ａは、低圧ガス管４２ａに接続される低圧弁として、第１低圧弁１２２－１と、第１低圧弁１２２－１と並列に接続される第２低圧弁１２２－２とを有する。第１低圧弁１２２－１の流路断面積は図４に示した低圧弁１２２と同等である。第２低圧弁１２２－２の流路断面積は、第１低圧弁１２２－１の流路断面積よりも小さい。負荷側ユニット７０ａが暖房運転を行う際、第１低圧弁１２２－１が開状態に設定される。 As shown in FIG. 10, the connection port 81a is a low pressure valve connected to the low pressure gas pipe 42a, and is a second low pressure valve connected in parallel with the first low pressure valve 122-1 and the first low pressure valve 122-1. And 122-2. The flow passage cross-sectional area of the first low pressure valve 122-1 is equal to that of the low pressure valve 122 shown in FIG. The flow passage cross-sectional area of the second low pressure valve 122-2 is smaller than the flow passage cross-sectional area of the first low pressure valve 122-1. When the load side unit 70a performs the heating operation, the first low pressure valve 122-1 is set to the open state.
　本実施の形態２における制御部９０の動作を、図９および図１１を参照して説明する。図１１は、本発明の実施の形態２の空気調和装置における制御部が、図９に示したステップＳ１０４の処理で実行する処理の一例を示すフローチャートである。ここでは、制御部９０が接続ポート８１ａに対して冷媒戻り処理を行う場合で説明する。 The operation of the control unit 90 in the second embodiment will be described with reference to FIGS. 9 and 11. FIG. 11 is a flowchart showing an example of processing executed by the control unit in the air conditioning apparatus according to Embodiment 2 of the present invention in the processing of step S104 shown in FIG. Here, the case where the control unit 90 performs the refrigerant return process on the connection port 81a will be described.
　図９に示したステップＳ１０４において、制御部９０は、高圧弁１２１を閉状態から開状態に切り替える（ステップＳ１４１）。制御部９０は、第１低圧弁１２２－１を閉じた状態で、第２低圧弁１２２－２を閉状態から開状態に切り替える（ステップＳ１４２）。第２低圧弁１２２－２が閉状態から開状態に切り替わると、第１中継器３０と第２中継器５０ａとの間に滞留する冷媒が高圧ガス管４３ａから低圧ガス管４２ａに流れる。また、第２低圧弁１２２－２の流路断面積は第１低圧弁１２２－１の流路断面積より小さいので、冷凍能力の低下が抑制される。さらに、冷媒が高圧ガス管４３ａから低圧ガス管４２ａに勢いよく流れこむことが抑制される。その結果、ガス枝管７５ａおよび負荷側熱交換器７１ａに大きな圧力負荷がかかることが抑制される。また、高圧のガス冷媒が低圧ガス管４２ａに流れ込むときに発生する音の大きさが低減する。 In step S104 shown in FIG. 9, the control unit 90 switches the high pressure valve 121 from the closed state to the open state (step S141). The control unit 90 switches the second low pressure valve 122-2 from the closed state to the open state with the first low pressure valve 122-1 closed (step S 142). When the second low pressure valve 122-2 is switched from the closed state to the open state, the refrigerant remaining between the first relay 30 and the second relay 50a flows from the high pressure gas pipe 43a to the low pressure gas pipe 42a. Further, since the flow passage cross-sectional area of the second low pressure valve 122-2 is smaller than the flow passage cross-sectional area of the first low pressure valve 122-1, a decrease in the refrigeration capacity is suppressed. Further, the refrigerant is prevented from flowing vigorously from the high pressure gas pipe 43a to the low pressure gas pipe 42a. As a result, application of a large pressure load to the gas branch pipe 75a and the load side heat exchanger 71a is suppressed. Further, the magnitude of the sound generated when the high pressure gas refrigerant flows into the low pressure gas pipe 42a is reduced.
　続いて、図９に示したステップＳ１０５において、第２低圧弁１２２－２が開状態になってから設定時間が経過すると、ステップＳ１０６において、制御部９０は、高圧弁１２１および第２低圧弁１２２－２を開状態から閉状態に切り替える。 Subsequently, in step S105 shown in FIG. 9, when the set time has passed since the second low pressure valve 122-2 was opened, the control unit 90 causes the high pressure valve 121 and the second low pressure valve 122 to go to step S106. -2 switches from the open state to the closed state.
　本実施の形態２の空気調和装置１は、第１中継器３０と第２中継器との間の高圧ガス管に滞留する冷媒を熱源機１０に戻す際、流路断面積が小さい第２低圧弁１２２－２を開けて、高圧ガス管から冷媒を低圧ガス管に流通させる。第２低圧弁１２２－２の流路断面積は第１低圧弁１２２－１の流路断面積より小さいので、冷凍能力の低下が抑制される。本実施の形態２によれば、滞留する冷媒を熱源機１０に戻せるだけでなく、冷凍能力の低下が抑制される。また、高圧ガス管から低圧ガス管に冷媒が勢いよく流れこむことが抑制されるので、冷媒配管への圧力負荷が抑制され、発生する音の大きさが低減する。 The air conditioner 1 of the second embodiment has a second low pressure having a small flow passage cross-sectional area when returning the refrigerant remaining in the high pressure gas pipe between the first relay 30 and the second relay to the heat source unit 10. The valve 122-2 is opened to flow the refrigerant from the high pressure gas pipe to the low pressure gas pipe. Since the flow passage cross-sectional area of the second low pressure valve 122-2 is smaller than the flow passage cross-sectional area of the first low pressure valve 122-1, a decrease in refrigeration capacity is suppressed. According to the second embodiment, not only can the stagnating refrigerant be returned to the heat source unit 10, but also the reduction of the refrigeration capacity is suppressed. Further, since the refrigerant is suppressed from flowing vigorously from the high pressure gas pipe into the low pressure gas pipe, the pressure load on the refrigerant pipe is suppressed, and the magnitude of the generated sound is reduced.
　なお、図１１に示す手順において、ステップＳ１４２の後に、制御部９０は、第１低圧弁１２２－１を閉状態から開状態に切り替えてもよい。第１低圧弁１２２－１が開く前に、第２低圧弁１２２－２を介して冷媒が高圧ガス管４３ａから低圧ガス管４２ａに少し流入している。第１低圧弁１２２－１が開いたとき、冷媒配管への圧力負荷と音の発生とが抑制される。その後に第２低圧弁１２２－２が開くことで、冷媒を熱源機１０に効率よく戻すことができる。 In the procedure shown in FIG. 11, after step S142, the control unit 90 may switch the first low pressure valve 122-1 from the closed state to the open state. Before the first low pressure valve 122-1 is opened, the refrigerant is slightly flowing from the high pressure gas pipe 43a into the low pressure gas pipe 42a via the second low pressure valve 122-2. When the first low pressure valve 122-1 is opened, the pressure load on the refrigerant pipe and the generation of sound are suppressed. Thereafter, by opening the second low pressure valve 122-2, the refrigerant can be efficiently returned to the heat source unit 10.
　上述の第１および第２の実施の形態において、設定時間は決められた時間に限らない。制御部９０が設定時間を更新してもよい。制御部９０は、空気調和装置１が複数の熱源機１０を有する場合、運転している熱源機１０の台数に比例して設定時間を長くしてもよい。この場合、熱源機１０への過剰に冷媒量を戻すことが抑制され、運転している熱源機１０に適した量の冷媒を戻すことができる。 In the first and second embodiments described above, the setting time is not limited to the determined time. The control unit 90 may update the set time. When the air conditioning apparatus 1 has a plurality of heat source units 10, the control unit 90 may lengthen the set time in proportion to the number of the heat source units 10 being operated. In this case, excessive return of the amount of refrigerant to the heat source unit 10 is suppressed, and an amount of refrigerant suitable for the operating heat source unit 10 can be returned.
　ただし、熱源機１０が複数の場合、各熱源機１０が保有する冷媒量が平均化されていない場合もある。例えば、２台の熱源機１０が運転している場合、一方の熱源機１０に冷媒が偏って、他方の熱源機１０に冷媒が不足している場合がある。冷媒量センサ２５が冷媒量を測定する機能を備えていると、制御部９０は、複数の熱源機１０の冷媒量センサ２５から測定値を取得し、熱源機１０同士で冷媒量が均等になるように各圧縮機１１を制御し、各熱源機１０の冷媒量を平均化する。その上で、制御部９０は、冷媒量が不足していると判定すると、設定時間を長くする。冷媒量が不足しているか否かの判定は、１台の熱源機１０に適正な冷媒量と、制御部９０が算出した冷媒量とを比較して行う。１台の熱源機１０に適正な冷媒量として基準値がメモリ９１に格納されている。制御部９０は、算出した冷媒量が基準値未満であれば、設定時間を長くする。 However, when there are a plurality of heat source units 10, the amount of refrigerant held by each heat source unit 10 may not be averaged. For example, when two heat source units 10 are operating, the refrigerant may be biased to one heat source unit 10 and the other heat source unit 10 may be short of refrigerant. When the refrigerant amount sensor 25 has a function of measuring the amount of refrigerant, the control unit 90 acquires measurement values from the refrigerant amount sensors 25 of the plurality of heat source units 10, and the refrigerant amounts become uniform among the heat source units 10 As described above, the compressors 11 are controlled, and the amounts of refrigerant of the heat source units 10 are averaged. Then, if the control unit 90 determines that the amount of refrigerant is insufficient, the control unit 90 extends the set time. It is determined whether the amount of refrigerant is insufficient by comparing the amount of refrigerant appropriate for one heat source unit 10 with the amount of refrigerant calculated by the control unit 90. A reference value is stored in the memory 91 as an appropriate amount of refrigerant for one heat source unit 10. If the calculated amount of refrigerant is less than the reference value, the control unit 90 lengthens the set time.
　また、上述の第１および第２の実施の形態において、メモリ９１が冷媒回収処理の履歴を記憶し、制御部９０が冷媒回収処理の履歴を参照して、設定時間を更新してもよい。この場合の制御部９０の動作の一例を説明する。制御部９０は、冷媒回収処理を行う度に、冷媒回収処理に関する時間をメモリ９１に記録する。そして、制御部９０は、メモリが記録する冷媒回収処理の履歴を参照し、冷媒回収処理の時間間隔が短いほど、設定時間を長い時間に更新する。この構成によれば、制御部９０は、メモリ９１が記憶する、冷媒回収処理の時間間隔を基に、冷媒量が不足しているか否かを判定し、判定結果を設定時間に反映させる。制御部９０は、冷媒回収処理の時間間隔が長いほど、設定時間を短くし、冷媒回収処理の時間間隔が短いほど、設定時間を長くする。このようにして設定時間を更新することで、熱源機１０に戻す冷媒量を適正化し、かつ冷凍能力の低下を抑制できる。 In the first and second embodiments described above, the memory 91 may store the history of the refrigerant recovery process, and the control unit 90 may update the set time with reference to the history of the refrigerant recovery process. An example of the operation of the control unit 90 in this case will be described. The control unit 90 records the time related to the refrigerant recovery process in the memory 91 every time the refrigerant recovery process is performed. Then, the control unit 90 refers to the history of the refrigerant recovery process recorded by the memory, and updates the set time to a longer time as the time interval of the refrigerant recovery process is shorter. According to this configuration, the control unit 90 determines whether the amount of refrigerant is insufficient based on the time interval of the refrigerant recovery process stored in the memory 91, and reflects the determination result in the set time. The control unit 90 shortens the set time as the time interval of the refrigerant recovery process is longer, and lengthens the set time as the time interval of the refrigerant recovery process is shorter. By updating the set time in this manner, the amount of refrigerant returned to the heat source unit 10 can be made appropriate, and a decrease in the refrigeration capacity can be suppressed.
　従来、空気調和装置の運転状態が変化しても、高圧ガス管と低圧ガス管とをバイパスする回路が開状態のままなので、単位時間あたり一定量しか冷媒を回収できなかった。これに対して、上述したように、圧縮機１１の運転台数および冷媒回収の時間間隔のうち、一方および両方を基に、制御部９０が設定時間を更新する。そのため、運転状態の変化に応じて、適正な冷媒量を熱源機１０に回収できる。 Conventionally, even if the operating condition of the air conditioner changes, the refrigerant bypassing the high pressure gas pipe and the low pressure gas pipe remains open, so that only a certain amount of refrigerant can be recovered per unit time. On the other hand, as described above, the control unit 90 updates the set time based on one and both of the number of operating compressors 11 and the time interval of refrigerant recovery. Therefore, the appropriate amount of refrigerant can be recovered to the heat source unit 10 according to the change in the operating state.
　また、上述の第１および第２の実施の形態において、メモリ９１が冷媒回収処理の冷媒量の履歴を記憶し、制御部９０が履歴を参照して、冷媒回収効率が最もよい第２中継器を選択するようにしてもよい。この場合の制御部９０の動作の一例を説明する。冷媒量センサ２５が冷媒量を測定する機能を備えている。制御部９０は、冷媒回収処理を行う度に、制御対象となった接続ポートが属する第２中継器と冷媒量センサ２５が測定する冷媒量とを関連付けてメモリ９１に記録する。制御部９０は、図９に示したステップＳ１０３において、１つの接続ポートを選択する際、メモリ９１が記録した情報を参照する。そして、制御部９０は、記録された冷媒量のうち、最も多い冷媒量に関連付けて記録された第２中継器から１つの接続ポートを選択する。この構成によれば、制御部９０が冷媒回収処理を行う際、複数の第２中継器５０ａおよび５０ｂのうち、冷媒回収効率が最も高い第２中継器の接続ポートを選択するため、設定時間に冷媒を熱源機１０に戻す量が最も多くなる。その結果、冷媒回収の効率を上げるとともに、冷凍能力の低下を抑制できる。 Further, in the first and second embodiments described above, the memory 91 stores the history of the refrigerant amount in the refrigerant recovery process, and the control unit 90 refers to the history, and the second relay with the best refrigerant recovery efficiency. May be selected. An example of the operation of the control unit 90 in this case will be described. The refrigerant amount sensor 25 has a function of measuring the amount of refrigerant. Every time the refrigerant recovery processing is performed, the control unit 90 associates the second relay to which the connection port to be controlled belongs and the amount of refrigerant measured by the refrigerant amount sensor 25 and records them in the memory 91. The control unit 90 refers to the information recorded in the memory 91 when selecting one connection port in step S103 shown in FIG. Then, the control unit 90 selects one connection port from the second relays recorded in association with the largest refrigerant amount among the recorded refrigerant amounts. According to this configuration, when the control unit 90 performs the refrigerant recovery process, in order to select the connection port of the second relay having the highest refrigerant recovery efficiency among the plurality of second relays 50a and 50b, The amount of return of the refrigerant to the heat source unit 10 is the largest. As a result, the efficiency of refrigerant recovery can be increased, and a decrease in refrigeration capacity can be suppressed.
　１　空気調和装置、１０　熱源機、１１　圧縮機、１２　流路切替弁、１３　熱源側熱交換器、１４　アキュムレータ、１５　流路調整ユニット、１６　第１の逆止弁、１７　第２の逆止弁、１８　第３の逆止弁、１９　第４の逆止弁、２２　低圧管、２３　高圧管、２５　冷媒量センサ、３０　第１中継器、３２　気液分離装置、３３　第１の熱交換部、３４　第２の熱交換部、３５　第１の流量制御装置、３６　第２の流量制御装置、４１、４１ａ、４１ｂ　液管、４２、４２ａ、４２ｂ　低圧ガス管、４３、４３ａ、４３ｂ　高圧ガス管、４５　バイパス液管、４６　第１分岐ユニット、４７　第２分岐ユニット、５０ａ、５０ｂ　第２中継器、５１　液管、５２　第３の熱交換部、５３　第３の流量制御装置、５４　バイパス管、６１ａ、６１ｃ　第１分岐ユニット、６２ａ、６２ｃ　第２分岐ユニット、７０ａ～７０ｄ　負荷側ユニット、７１ａ～７１ｄ　負荷側熱交換器、７２ａ～７２ｄ　負荷側流量制御装置、７５ａ～７５ｄ　ガス枝管、７６ａ～７６ｄ　液枝管、８１、８１ａ～８１ｄ　接続ポート、８２、８２ａ～８２ｄ　接続ポート、８３、８３ａ～８３ｄ　接続ポート、８４、８４ａ～８４ｄ　接続ポート、８５、８５ａ～８５ｄ　接続ポート、８６、８６ａ～８６ｄ　接続ポート、８７、８７ａ～８７ｄ　接続ポート、８８、８８ａ～８８ｄ　接続ポート、９０　制御部、９１　メモリ、９２　ＣＰＵ、１００　空気調和装置、１１１　高圧分岐配管、１１２　低圧分岐配管、１２１　高圧弁、１２２　低圧弁、１２２－１　第１低圧弁、１２２－２　第２低圧弁、１３１、１３２　分岐配管、１４１、１４２　逆止弁。 REFERENCE SIGNS LIST 1 air conditioner, 10 heat source unit, 11 compressor, 12 flow path switching valve, 13 heat source side heat exchanger, 14 accumulator, 15 flow path adjusting unit, 16 first check valve, 17 second check valve , 18 third check valve, 19 fourth check valve, 22 low pressure pipe, 23 high pressure pipe, 25 refrigerant quantity sensor, 30 first relay, 32 gas-liquid separator, 33 first heat exchange unit, 34 second heat exchange unit, 35 first flow control device, 36 second flow control device, 41, 41a, 41b liquid pipe, 42, 42a, 42b low pressure gas pipe, 43, 43a, 43b high pressure gas pipe, 45 bypass liquid pipe, 46 first branch unit, 47 second branch unit, 50a, 50b second relay, 51 liquid pipe, 52 third heat exchange unit, 53 third flow control device, 54 bypass pipe, 1a, 61c first branch unit, 62a, 62c second branch unit, 70a to 70d load side unit, 71a to 71d load side heat exchanger, 72a to 72d load side flow control device, 75a to 75d gas branch pipe, 76a to 76d 76d Liquid branch pipe 81, 81a to 81d connection port 82, 82a to 82d connection port 83, 83a to 83d connection port 84, 84a to 84d connection port 85, 85a to 85d connection port 86, 86a to 86d Connection port 87, 87a to 87d connection port, 88, 88a to 88d connection port, 90 control unit, 91 memory, 92 CPU, 100 air conditioner, 111 high pressure branch piping, 112 low pressure branch piping, 121 high pressure valve, 122 low pressure Valve, 122-1 first low pressure valve, 122-2 2 the low pressure valve, 131 and 132 branch pipe, 141 and 142 check valve.

Claims (8)

  1. 　熱源側熱交換器および圧縮機を有する熱源機と、
    　前記熱源機と冷媒配管で接続される第１中継器と、
    　高圧ガス管、低圧ガス管および液管で、前記第１中継器と接続される第２中継器と、
    　前記高圧ガス管に接続される高圧弁と、前記低圧ガス管に接続される低圧弁とを有し、前記第２中継器に設けられた複数の接続ポートと、
    　前記圧縮機および前記複数の接続ポートを制御する制御部と、を有し、
    　前記制御部は、
    　前記第２中継器に接続された負荷側ユニットが全て停止している場合、前記複数の接続ポートのうち、少なくとも１つの接続ポートの前記高圧弁および前記低圧弁を開状態にして、前記高圧ガス管と前記低圧ガス管とを接続させる冷媒回収処理を行う、空気調和装置。     A heat source machine having a heat source side heat exchanger and a compressor;
    A first relay connected to the heat source unit and a refrigerant pipe;
    A second relay connected to the first relay by a high pressure gas pipe, a low pressure gas pipe, and a liquid pipe;
    A plurality of connection ports provided in the second relay, comprising: a high pressure valve connected to the high pressure gas pipe; and a low pressure valve connected to the low pressure gas pipe;
    A controller that controls the compressor and the plurality of connection ports;
    The control unit
    When all the load side units connected to the second relay stop, the high pressure valve and the low pressure valve of at least one of the plurality of connection ports are opened and the high pressure gas is opened. An air conditioner performing refrigerant recovery processing in which a pipe and the low pressure gas pipe are connected.
  2. 　前記制御部は、
    　前記熱源機が暖房流路に設定された状態であって、前記第２中継器に接続される負荷側ユニットの全てが運転を停止しているとき、該第２中継器の前記複数の接続ポートから、１つの接続ポートを選択して該接続ポートを前記開状態にする、請求項１に記載の空気調和装置。     The control unit
    The plurality of connection ports of the second relay when the heat source unit is set in the heating flow path and all of the load side units connected to the second relay stop operating. The air conditioning apparatus according to claim 1, wherein one connection port is selected to open the connection port.
  3. 　前記制御部は、
    　前記複数の接続ポートのうち、前記第１中継器から前記高圧ガス管の距離が最も遠い位置にある接続ポートを選択して前記開状態にする、請求項１または２に記載の空気調和装置。     The control unit
    The air conditioning apparatus according to claim 1, wherein a connection port located at a position where the distance from the first relay to the high pressure gas pipe is the longest among the plurality of connection ports is selected to be in the open state.
  4. 　前記低圧弁は、
    　第１低圧弁と、該第１低圧弁と並列に接続され、該第１低圧弁よりも流路断面積が小さい第２低圧弁とを有し、
    　前記制御部は、
    　前記第１低圧弁を閉じた状態で、前記第２低圧弁を前記開状態にする、請求項１～３のいずれか１項に記載の空気調和装置。     The low pressure valve is
    A first low pressure valve, and a second low pressure valve connected in parallel to the first low pressure valve and having a flow passage cross-sectional area smaller than that of the first low pressure valve;
    The control unit
    The air conditioner according to any one of claims 1 to 3, wherein the second low pressure valve is brought into the open state with the first low pressure valve closed.
  5. 　前記制御部は、
    　前記冷媒回収処理に用いる前記接続ポートに前記負荷側ユニットが接続されている場合、前記高圧弁および前記低圧弁を前記開状態にする前に、該負荷側ユニットに設けられた流量制御装置を開閉する、請求項１～４のいずれか１項に記載の空気調和装置。     The control unit
    When the load side unit is connected to the connection port used for the refrigerant recovery process, the flow control device provided in the load side unit is opened and closed before the high pressure valve and the low pressure valve are opened. The air conditioner according to any one of claims 1 to 4, wherein
  6. 　前記第１中継器に、複数の前記熱源機が接続され、
    　前記制御部は、
    　複数の前記熱源機のうち、運転中の熱源機の台数に比例して、前記接続ポートの前記開状態の時間を長くする、請求項１～５のいずれか１項に記載の空気調和装置。     A plurality of the heat source units are connected to the first relay,
    The control unit
    The air conditioner according to any one of claims 1 to 5, wherein the open time of the connection port is lengthened in proportion to the number of heat source units in operation among the plurality of heat source units.
  7. 　冷媒回路を循環する冷媒の量を測定する冷媒量センサをさらに有し、
    　前記第２中継器が複数設けられ、
    　前記制御部は、
    　複数の前記第２中継器から回収される冷媒量を記憶しており、
    　前記冷媒回収処理を行う際、記録された冷媒量のうち、最も多い冷媒量に関連付けて記録された第２中継器の前記接続ポートを選択する、請求項１～６のいずれか１項に記載の空気調和装置。     And a refrigerant amount sensor for measuring the amount of refrigerant circulating in the refrigerant circuit,
    A plurality of second relays are provided,
    The control unit
    The amount of refrigerant collected from the plurality of second relays is stored,
    7. The connection port according to claim 1, wherein the connection port of the second relay recorded in association with the largest refrigerant amount among the recorded refrigerant amounts is selected when the refrigerant recovery processing is performed. Air conditioning equipment.
  8. 　前記制御部は、
    　前記冷媒回収処理を行う度に該冷媒回収処理を行った時間を記憶し、
    　記録された前記冷媒回収処理の時間間隔が短いほど、前記接続ポートの前記開状態の時間を長くする、請求項１～７のいずれか１項に記載の空気調和装置。     The control unit
    Every time the refrigerant recovery process is performed, the time when the refrigerant recovery process is performed is stored,
    The air conditioner according to any one of claims 1 to 7, wherein the open time of the connection port is lengthened as the recorded time interval of the refrigerant recovery process is shorter.
PCT/JP2017/026958 2017-07-26 2017-07-26 Air conditioner WO2019021380A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0571825A (en) * 1991-09-12 1993-03-23 Matsushita Refrig Co Ltd Multiroom type air-conditioner
JP2003097864A (en) * 2001-09-26 2003-04-03 Mitsubishi Electric Corp Air conditioner
JP2008116073A (en) * 2006-11-01 2008-05-22 Daikin Ind Ltd Air conditioning apparatus
JP2013015280A (en) * 2011-07-05 2013-01-24 Daikin Industries Ltd Outdoor multi-unit
WO2017042967A1 (en) * 2015-09-11 2017-03-16 ジョンソンコントロールズ ヒタチ エア コンディショニング テクノロジー（ホンコン） リミテッド Air conditioner

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0571825A (en) * 1991-09-12 1993-03-23 Matsushita Refrig Co Ltd Multiroom type air-conditioner
JP2003097864A (en) * 2001-09-26 2003-04-03 Mitsubishi Electric Corp Air conditioner
JP2008116073A (en) * 2006-11-01 2008-05-22 Daikin Ind Ltd Air conditioning apparatus
JP2013015280A (en) * 2011-07-05 2013-01-24 Daikin Industries Ltd Outdoor multi-unit
WO2017042967A1 (en) * 2015-09-11 2017-03-16 ジョンソンコントロールズ ヒタチ エア コンディショニング テクノロジー（ホンコン） リミテッド Air conditioner

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