[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO2015064172A1 - Climatiseur - Google Patents

Climatiseur Download PDF

Info

Publication number
WO2015064172A1
WO2015064172A1 PCT/JP2014/071045 JP2014071045W WO2015064172A1 WO 2015064172 A1 WO2015064172 A1 WO 2015064172A1 JP 2014071045 W JP2014071045 W JP 2014071045W WO 2015064172 A1 WO2015064172 A1 WO 2015064172A1
Authority
WO
WIPO (PCT)
Prior art keywords
refrigerant
receiver
flow rate
amount
rate adjusting
Prior art date
Application number
PCT/JP2014/071045
Other languages
English (en)
Japanese (ja)
Inventor
上野円
田中慎一
浅地野衣
杉山昭
Original Assignee
シャープ株式会社
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 シャープ株式会社 filed Critical シャープ株式会社
Publication of WO2015064172A1 publication Critical patent/WO2015064172A1/fr

Links

Images

Classifications

    • 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
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
    • F24F11/84—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using valves
    • 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
    • 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
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/30—Expansion means; Dispositions thereof
    • F25B41/39—Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator
    • 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
    • F25B45/00—Arrangements for charging or discharging refrigerant
    • 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
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/006—Compression machines, plants or systems with reversible cycle not otherwise provided for two pipes connecting the outdoor side to the indoor side with multiple indoor units
    • 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
    • F25B2345/00—Details for charging or discharging refrigerants; Service stations therefor
    • F25B2345/002—Collecting refrigerant from a 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
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/16—Receivers
    • 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
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2513—Expansion valves
    • 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
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2523—Receiver valves

Definitions

  • the present invention relates to an air conditioner that adjusts the amount of refrigerant flowing through a refrigerant circuit using a receiver that accumulates refrigerant.
  • a compressor, a four-way valve, a condenser, a throttling device, and an evaporator are sequentially connected by a pipe to form a refrigerant circuit in which the refrigerant circulates.
  • a receiver for storing refrigerant is provided between a condenser and an evaporator, and a high-pressure side throttle device and a low-pressure side throttle device are connected before and after the receiver.
  • the opening area of each expansion device is controlled so that the state quantity of the refrigerant circulating in the refrigerant circuit becomes a target value.
  • the refrigerant condensed in the condenser is decompressed by the high pressure side throttle device and flows into the receiver. And the refrigerant
  • the amount of refrigerant circulating in the refrigerant circuit is adjusted by accumulating the refrigerant in the receiver or removing the refrigerant from the receiver.
  • the optimum amount of refrigerant when the air-conditioning operation is performed varies depending on operation conditions such as the operation mode, the outside air temperature, and the room temperature.
  • the adjustment of the refrigerant amount is limited to the volume of the receiver and may not be adjusted to the optimum refrigerant amount.
  • an object of the present invention is to provide an air conditioner that can adjust the amount of refrigerant circulating in the refrigerant circuit to an optimum amount of refrigerant according to the operating state of the air conditioning operation.
  • the air conditioner of the present invention includes a refrigerant circuit in which a compressor, a condenser, a throttle unit, and an evaporator are connected by piping, and the throttle unit includes a plurality of receivers that store the refrigerant, and an amount of refrigerant that circulates through the refrigerant circuit. And a plurality of flow rate adjusting devices for adjusting the amount of refrigerant stored in each receiver in order to adjust the flow rate.
  • the flow control device When the flow control device operates according to the operating status, the amount of refrigerant accumulated in each receiver is adjusted. Thereby, the amount of refrigerant circulating through the refrigerant circuit changes, and the optimum amount of refrigerant according to the operating situation is obtained.
  • a plurality of flow control devices are arranged in series in the refrigerant circuit, a receiver is connected between adjacent flow control devices, and the flow control device located downstream of the receiver in the flow direction of the refrigerant operates, thereby receiving the receiver.
  • the amount of refrigerant that accumulates in the refrigerant changes.
  • the flow rate adjustment device When the flow rate adjustment device operates so that the refrigerant circulating in the refrigerant circuit is reduced, the refrigerant accumulates in the receiver located on the upstream side of the flow rate adjustment device in the flow direction of the refrigerant.
  • the flow rate adjusting device operates so that more refrigerant circulates in the refrigerant circuit, the refrigerant accumulated in the receiver positioned upstream of the flow rate adjusting device is discharged. In the flow direction of the refrigerant, the refrigerant does not accumulate in the receiver located on the downstream side of the flow rate adjusting device.
  • coolant amount collected for every receiver can be adjusted by operating a some flow control apparatus.
  • a control device for controlling the opening degree of the flow rate adjusting device controls the opening degree of at least one flow rate adjusting device and fully opens the other flow rate adjusting device.
  • the amount of refrigerant passing through the flow rate adjusting device changes, and the amount of refrigerant accumulated in the receiver can be adjusted.
  • the opening degree of one or a plurality of flow rate adjusting devices By controlling the opening degree of one or a plurality of flow rate adjusting devices, the number of receivers in which the refrigerant accumulates changes, and the amount of refrigerant that accumulates in the receivers can be adjusted.
  • the volume of each receiver is the same, but the volume of at least one receiver should be different.
  • the amount of refrigerant that can be accumulated in all receivers can be adjusted by the combination of receivers that accumulate refrigerant, and the amount of refrigerant that circulates can be adjusted more appropriately according to the operating conditions.
  • the outdoor heat exchanger has a volume smaller than that of the outdoor heat exchanger.
  • the volume of the receiver near the heat exchanger is smaller than the volume of the receiver near the indoor heat exchanger, and the volume of the outdoor heat exchanger is smaller than the volume of the indoor heat exchanger, the volume of the receiver near the outdoor heat exchanger is It is made larger than the volume of the receiver close to the indoor heat exchanger.
  • the control device decreases the rotational speed of the compressor.
  • the refrigerant circulating in the refrigerant circuit passes through the plurality of flow control devices, a pressure loss occurs in the refrigerant. Therefore, even if the flow rate adjusting device is opened to near full open, the amount of circulating refrigerant cannot be increased, resulting in insufficient refrigerant. Therefore, when the rotational speed of the compressor is lowered, the pressure loss is reduced as the optimum amount of refrigerant corresponding to the rotational speed decreases. This makes it possible to operate the flow rate adjusting device within a controllable range without opening the flow rate adjusting device to near full open, thereby eliminating the shortage of refrigerant.
  • the control device lowers the rotational speed of the fan that blows air toward the condenser when the rotational speed of the plurality of flow rate control devices is set to a predetermined opening or more and the rotational speed of the compressor is decreased.
  • the opening degree of the plurality of flow control devices is equal to or greater than the predetermined opening degree, the refrigerant shortage occurs as described above.
  • the refrigerant does not accumulate in the receiver, and the amount of refrigerant that circulates can be increased as compared with the case where only the rotation speed of the compressor is lowered.
  • a cooling pipe that cools the receiver by diverting a low-temperature refrigerant from the refrigerant circuit and a heating pipe that warms the receiver by diverting a high-temperature refrigerant from the refrigerant circuit are provided.
  • the refrigerant in the receiver is liquefied, so that the refrigerant easily flows into the receiver, and the refrigerant accumulates in the receiver.
  • the refrigerant in the receiver evaporates, so that the refrigerant is easily discharged from the receiver, and the refrigerant in the receiver is reduced.
  • the receiver is composed of multiple tanks. Since a small tank can be used, the tank can be arranged in a small gap, and the degree of freedom of arrangement of the receiver is increased.
  • a control device for controlling the opening degree of the flow rate adjusting device is provided so that the refrigerant amount circulating in the refrigerant circuit becomes an optimum refrigerant amount according to the air conditioning operation, and the control device is a mathematical expression representing a change in the discharge temperature of the compressor. Is used to determine whether or not the refrigeration cycle is stable, and after the refrigeration cycle is stabilized, the opening degree of the flow control device is controlled.
  • the amount of refrigerant circulating can be set to the optimum refrigerant amount according to the operating condition, and the air conditioning operation can be performed efficiently.
  • the figure which shows the inside of the outdoor unit in which a plurality of receivers are arranged Receiver layout in outdoor unit Air conditioner control block diagram The figure which shows the refrigerant circuit of the air conditioner of 3rd Embodiment.
  • Control flow chart when the flow control device is near full open Control flow chart when the flow control device is near full open
  • Control flowchart of prevention of dew condensation according to seventh embodiment The figure which shows the receiver by which the cooling tube and heating tube of 8th Embodiment were wound
  • the figure which shows the refrigerating cycle of 9th Embodiment The figure which shows the inside of the outdoor unit where a plurality of tanks are arranged Diagram showing receiver composed of multiple tanks The figure which shows the tank of other forms
  • Flowchart of refrigeration cycle stability determination of tenth embodiment (A) is a figure which shows the time change of the discharge temperature for every rotation speed of a compressor, (b) is a figure which shows the saturation curve of the discharge temperature for every parameter, (c) is discharge temperature according to the rotation speed of a compressor. Showing that the saturation curve changes (D) is a figure which shows that the saturation curve of discharge temperature changes according to outside air temperature, (e) is a figure which shows the approximate expression of the time change of discharge temperature.
  • the air conditioner of this embodiment includes a refrigerant circuit in which a compressor 1, a condenser 2, a throttle unit 3, and an evaporator 4 are connected by piping.
  • the throttle unit 3 includes a plurality of receivers 5 that store refrigerant and a plurality of flow rate adjusting devices 6 that adjust the amount of refrigerant circulating in the refrigerant circuit.
  • the receiver 5 has one entrance.
  • a connecting pipe 8 branched from a connecting pipe 7 that connects the condenser 2 and the evaporator 4 in the refrigerant circuit is connected to the inlet / outlet of the receiver 5.
  • the flow rate adjusting device 6 is an expansion valve and adjusts the flow rate and pressure of the refrigerant circulating in the refrigerant circuit.
  • the three receivers 5A, 5B, and 5C and the two flow rate adjusting devices 6A and 6B are alternately arranged along the refrigerant flow direction.
  • the high pressure side flow rate adjustment device 6A and the low pressure side flow rate adjustment device 6B are arranged in series in the refrigerant circuit.
  • the high pressure side flow rate adjustment device 6A is located upstream of the low pressure side flow rate adjustment device 6B in the refrigerant flow direction.
  • the first receiver 5A is between the condenser 2 and the high pressure side flow rate adjustment device 6A
  • the second receiver 5B is between the high pressure side flow rate adjustment device 6A and the low pressure side flow rate adjustment device 6B
  • the third receiver 5C is the low pressure side flow rate adjustment device.
  • Each is connected between the device 6B and the evaporator 4.
  • This air conditioner is a separate type composed of an indoor unit 10 and an outdoor unit 11.
  • the air conditioner performs air conditioning operations such as cooling operation and heating operation.
  • a four-way valve 12 is provided in the refrigerant circuit.
  • the indoor unit 10 is provided with an indoor heat exchanger 13, and the outdoor unit 11 includes a compressor 1, a four-way valve 12, an outdoor heat exchanger 14, two flow rate adjusting devices 6 a and 6 b, and three receivers 5 a, 5 b and 5 c. Is provided.
  • the outdoor unit 11 is provided with an outdoor heat exchanger fan 15, and the indoor unit 10 is provided with an indoor heat exchanger fan 16.
  • 17 is a two-way valve used for charging refrigerant
  • 18 is a three-way valve
  • 19 is a two-way valve for bypass piping.
  • the refrigerant discharged from the compressor 1 returns to the compressor 1 through the condenser 2, the throttle unit 3, and the evaporator 4. In this way, a refrigeration cycle is formed in which the refrigerant circulates through the refrigerant circuit.
  • the flow direction of the refrigerant is switched by the four-way valve 12 according to the operation mode of the air conditioning operation.
  • the indoor heat exchanger 13 becomes the evaporator 4 and the outdoor heat exchanger 14 becomes the condenser 2.
  • the first flow rate adjusting device 6a is the high pressure side flow rate adjusting device 6A
  • the second flow rate adjusting device 6b is the low pressure side flow rate adjusting device 6B.
  • the receiver 5a corresponds to the receiver 5A
  • the receiver 5b corresponds to the receiver 5B
  • the receiver 5c corresponds to the receiver 5C.
  • the second flow rate adjusting device 6b is the high pressure side flow rate adjusting device 6A
  • the first flow rate adjusting device 6a is the low pressure side flow rate adjusting device 6B.
  • the receiver 5c corresponds to the receiver 5A
  • the receiver 5b corresponds to the receiver 5B
  • the receiver 5a corresponds to the receiver 5C.
  • the receiver 5 is a cylindrical container, and the volume and shape of each receiver 5 are the same. An entrance / exit is formed on the bottom surface of the receiver 5, and the entrance / exit is directed downward.
  • the receiver 5 is positioned above the connection pipe 7 that connects the outdoor heat exchanger 14 and the indoor heat exchanger 13 and the flow rate adjusting devices 6.
  • the connecting pipe 8 has a smaller diameter than the connection pipe 7 and is provided so as to extend upward from the connection pipe 7.
  • the upper part of the connecting pipe 8 is connected to the bottom surface of the receiver 5, and the lower part is connected to the connecting pipe 7.
  • the connection pipe 8 and the connection pipe 7 are connected in an inverted T shape.
  • the receiver 5 provided in the outdoor unit 11 is disposed in the vicinity of the outdoor heat exchanger 14. As shown in FIGS. 3 and 4, the outdoor heat exchanger 14 is arranged on the back side of the outdoor unit 11, and a refrigerant circuit pipe or valve including a connection pipe 7 is provided on one side of the outdoor heat exchanger 14 in the left-right direction. Such parts are arranged. A gap is formed between each part. Each receiver 5 is arranged on one side in the outdoor unit 11 and arranged in a gap between components. Since the receiver 5 is arrange
  • the pipe connecting the discharge side of the compressor 1 and the outdoor heat exchanger 14 passes through the back side of the outdoor unit 11 and has a larger diameter than other pipes.
  • Each receiver 5 is attached to this large-diameter pipe.
  • Each receiver 5 is arranged separately from other pipes other than the large-diameter pipe. Each receiver 5 does not come into contact with other pipes or parts.
  • the receiver 5 is brazed to the pipe, or the receiver 5 is fixed to the pipe by a binding member such as a band.
  • Each receiver 5 is fixed so as not to contact each other. Since the high-temperature and high-pressure gas refrigerant flows through this pipe in a stable state during the cooling mode, vibration of the pipe is small.
  • vibration of the receiver 5 can be suppressed, and noise when the refrigerant enters and exits the receiver 5 can be eliminated. Further, even if the receiver 5 or the pipe vibrates, each receiver 5 does not come into contact with other pipes or parts other than the large-diameter pipe, so that no noise is generated. Since the shape of the gap in the outdoor unit 11 is complicated, the shape of the receiver 5 may be changed according to the shape of the gap. However, the volume of the receiver 5 is not changed.
  • the air conditioner includes a control device 20 that controls the refrigeration cycle and performs an air conditioning operation.
  • the air conditioner includes a condenser temperature sensor 21 that detects the temperature of the condenser 2, an evaporator temperature sensor 22 that detects the temperature of the evaporator 4, and a discharge temperature that detects the discharge temperature of the refrigerant discharged from the compressor 1.
  • a sensor 23, a suction temperature sensor 24 for detecting the suction temperature of the refrigerant sucked into the compressor 1, a room temperature sensor 25, and an outside air temperature sensor 26 are provided.
  • the control device 20 controls the refrigeration cycle by controlling the operations of the compressor 1, the fans 15, 16 and the flow rate adjusting device 6 based on the outputs of these temperature sensors according to the air conditioning operation desired by the user.
  • control device 20 includes an indoor control unit provided in the indoor unit 10 and an outdoor control unit provided in the outdoor unit 11.
  • the indoor control unit and the outdoor control unit are connected so as to be communicable with each other, and both cooperate to control operations of the indoor unit 10 and the outdoor unit 11.
  • the plurality of flow rate adjusting devices 6 provided in the refrigerant circuit are the same type of expansion valve.
  • the expansion valve can vary the opening degree between 0 and 500 steps.
  • the expansion valve has an opening area corresponding to the opening, and the amount of refrigerant passing therethrough can be varied. Therefore, the magnitude of the opening degree of each flow rate adjustment device 6 corresponds to the magnitude of the refrigerant amount passing through the flow rate adjustment device 6. As the opening degree increases, the amount of refrigerant passing therethrough increases.
  • the opening degree of the high pressure side flow rate adjustment device 6A and the low pressure side flow rate adjustment device 6B By changing the opening degree of the high pressure side flow rate adjustment device 6A and the low pressure side flow rate adjustment device 6B, the amount of refrigerant passing through each flow rate adjustment device 6A, 6B changes, and the upstream side of each flow rate adjustment device 6A, 6B. A refrigerant pressure difference occurs between the downstream side and the downstream side.
  • the opening degree of the low pressure side flow rate adjustment device 6B is made larger than the opening degree of the high pressure side flow rate adjustment device 6A, the pressure on the upstream side of the high pressure side flow rate adjustment device 6A becomes higher than the pressure on the downstream side.
  • the liquid refrigerant flows into the connecting pipe 8 of the first receiver 5A on the upstream side of the high-pressure side flow rate adjusting device 6A, and the liquid refrigerant accumulates in the first receiver 5A. Liquid refrigerant does not accumulate in the second receiver 5B and the third receiver 5C on the downstream side of the high-pressure side flow control device 6A.
  • the pressure in the 2nd receiver 5B is lower than the pressure of the refrigerant
  • coolant between the high pressure side flow volume adjustment apparatus 6A and the low pressure side flow volume adjustment apparatus 6B a liquid refrigerant flows into the 2nd receiver 5B according to the pressure difference. Accumulate.
  • the opening degree of the high pressure side flow rate adjusting device 6A is increased, the pressure on the upstream side of the high pressure side flow rate adjusting device 6A is lowered.
  • the liquid refrigerant accumulated in the first receiver 5A is discharged to the refrigerant circuit.
  • the opening degree of the high pressure side flow rate adjustment device 6A is made larger than the opening degree of the low pressure side flow rate adjustment device 6B, the upstream pressure of the low pressure side flow rate adjustment device 6B becomes higher than the downstream pressure.
  • liquid refrigerant accumulates in the first receiver 5A and the second receiver 5B on the upstream side of the low-pressure flow rate adjustment device 6B, and the liquid refrigerant is stored in the third receiver 5C on the downstream side of the low-pressure flow rate adjustment device 6B. I do not collect.
  • the opening degree of the low pressure side flow rate adjusting device 6B is increased, the pressure on the upstream side of the low pressure side flow rate adjusting device 6B is lowered.
  • the liquid refrigerant accumulated in the first receiver 5A and the second receiver 5B is discharged to the refrigerant circuit.
  • the control device 20 controls the refrigeration cycle so that the room temperature becomes the set temperature. At this time, the control device 20 adjusts the amount of refrigerant so that the amount of refrigerant circulating through the refrigerant circuit is optimized in accordance with the operating conditions. A part of the refrigerant filled in the refrigerant circuit is accumulated in the receiver 5, and the remaining refrigerant circulates in the refrigerant circuit. Of the circulating refrigerant amount, the refrigerant amount when the COP is maximum is set as the optimum refrigerant amount.
  • the optimum amount of refrigerant varies depending on the operation mode, and also varies depending on the rotation speed of the compressor 1, the outside air temperature, the room temperature, and the volume of the heat exchanger indoors and outdoors. For example, in the cooling mode, more refrigerant is required in the rapid cooling mode in which cooling is performed rapidly.
  • the control device 20 sets the target rotational speed of the compressor 1 based on the set temperature and the room temperature, and the high-pressure side and low-pressure side flow control devices 6A and 6B according to the target rotational speed. Determine the opening.
  • the control device 20 controls the compressor 1, the flow rate adjusting devices 6A and 6B, the fans 15 and 16, and the like according to the determined operating conditions.
  • the control apparatus 20 determines the initial opening degree of each flow volume adjustment apparatus 6A, 6B according to target rotation speed and operation modes (cooling mode, heating mode, etc.).
  • the control device 20 initializes the flow rate adjusting devices 6A and 6B. That is, after each flow rate adjusting device 6A, 6B is fully closed, each flow rate adjusting device 6A, 6B is opened to the initial opening degree. Thereafter, the compressor 1 is started and the refrigerant circulates through the refrigerant circuit.
  • the control device 20 operates the flow rate adjusting devices 6A and 6B so that the opening degree of the low pressure side flow rate adjusting device 6B is larger than the opening degree of the high pressure side flow rate adjusting device 6A.
  • the low pressure side flow rate adjustment device 6B is fully opened, and the high pressure side flow rate adjustment device 6A is set to the determined initial opening.
  • the rotational speed of the compressor 1 is constant. The liquid refrigerant that has accumulated in the second receiver 5B flows out into the refrigerant circuit.
  • the high-pressure flow rate adjusting device 6A by opening the high-pressure flow rate adjusting device 6A, a part of the liquid refrigerant that has accumulated in the first receiver 5A on the upstream side flows out to the refrigerant circuit.
  • the refrigerant circulating in the refrigerant circuit is increased, the supercooling on the outlet side of the condenser 2 is increased, and the air conditioning capability can be enhanced.
  • warm air having a higher temperature can be blown out from the start of operation.
  • the control device 20 When the refrigeration cycle is stabilized after the start of the air conditioning operation, the control device 20 performs refrigerant amount adjustment control so that the circulating refrigerant amount becomes the optimum refrigerant amount.
  • the determination of the stability of the refrigeration cycle is made based on the temperature of the refrigerant discharged from the compressor 1.
  • the control device 20 monitors the change in the discharge temperature based on the output of the discharge temperature sensor 23. When the change in the discharge temperature becomes small, the control device 20 recognizes that the discharge temperature is stable and determines that the refrigeration cycle is stable.
  • the opening degrees of the high-pressure side and low-pressure side flow rate adjusting devices 6A and 6B are set according to the operation conditions such as the operation mode, the degree of superheat, the rotation speed of the compressor 1, the outside air temperature, and the room temperature.
  • the control device 20 determines the number of rotations of the compressor 1 based on the operation mode and the outside air temperature, sets an optimum amount of refrigerant according to the number of revolutions, and becomes the optimum amount of refrigerant. In this way, the opening degree of each flow rate adjusting device 6A, 6B is determined. And the control apparatus 20 controls each flow volume adjustment apparatus 6A, 6B so that it may become the determined opening degree.
  • the opening degree of each of the flow rate adjusting devices 6A and 6B according to the operating condition is determined in advance by experiments or the like and stored in the memory of the control device 20.
  • the control device 20 reads the opening amounts of the flow rate adjustment devices 6A and 6B according to the current operation state from the memory, and operates the flow rate adjustment devices 6A and 6B according to the read opening amounts.
  • the control device 20 When the control device 20 confirms that the refrigeration cycle is stable, the control device 20 operates the high-pressure side and low-pressure side flow rate adjustment devices 6A and 6B so as to achieve the set opening degrees. That is, one flow rate adjusting device 6 is controlled and the other flow rate adjusting device 6 is fully opened. As the order of operation of the flow rate adjusting devices 6A and 6B, first, the other flow rate adjusting device 6 is fully opened, and then one flow rate adjusting device 6 operates to the set opening degree.
  • liquid refrigerant flows in and accumulates in the first receiver 5A.
  • Liquid refrigerant does not accumulate in the second and third receivers 5B and 5C. That is, in the second and third receivers 5B and 5C, the liquid refrigerant that does not enter or exit or that has accumulated is discharged.
  • liquid refrigerant flows into the first and second receivers 5A and 5B. Accumulate. Liquid refrigerant does not accumulate in the third receiver 5C. That is, in the third receiver 5C, the refrigerant does not enter or exit or the liquid refrigerant that has accumulated is discharged. In this way, by controlling the flow rate adjustment device 6 located downstream of the receiver 5 in the refrigerant flow direction, the amount of refrigerant accumulated in the receiver 5 located upstream of the flow rate adjustment device 6 can be adjusted. it can.
  • the opening degree of the two flow rate adjusting devices 6 may be controlled.
  • the opening degree of the low pressure side flow rate adjusting device 6B is controlled to be larger than the opening degree of the high pressure side flow rate adjusting device 6A, a pressure difference occurs between the refrigerant flowing on the upstream side and the downstream side of each flow rate adjusting device 6. . While the liquid refrigerant accumulates in the first receiver 5A, a little liquid refrigerant accumulates also in the second receiver 5B.
  • the opening of the high pressure side flow control device 6A is controlled to be larger than the opening of the low pressure flow control device 6B, liquid refrigerant accumulates in the second receiver 5B and a little liquid refrigerant also in the first receiver 5A. Accumulate.
  • each flow rate adjusting device 6 controls each flow rate adjusting device 6, the amount of refrigerant accumulated in each receiver 5 is different, and the amount of refrigerant circulating in the refrigerant circuit can be adjusted. And it can be made easy to the optimal refrigerant
  • the control device 20 changes the rotation speed of the compressor 1 according to the room temperature, the outside air temperature, and the like.
  • the optimal amount of refrigerant changes as the rotational speed of the compressor 1 changes.
  • the optimum refrigerant amount increases, and when the rotation speed of the compressor 1 decreases, the optimum refrigerant amount decreases.
  • the control device 20 When increasing the amount of refrigerant circulating in the refrigerant circuit, the control device 20 fully opens the low pressure side flow rate adjustment device 6B and controls the high pressure side flow rate adjustment device 6A.
  • the first receiver 5A liquid refrigerant flows in and accumulates, but in the second and third receivers 5B and 5C, the accumulated liquid refrigerant flows out. Accordingly, only the refrigerant amount corresponding to the volume of the first receiver 5A is accumulated, and the circulating refrigerant amount is increased.
  • the control device 20 When reducing the amount of refrigerant circulating through the refrigerant circuit, the control device 20 fully opens the high pressure side flow rate adjustment device 6A and controls the low pressure side flow rate adjustment device 6B. In the first and second receivers 5A and 5B, liquid refrigerant flows in and accumulates, but in the third receiver 5C, the accumulated liquid refrigerant flows out. Therefore, the refrigerant accumulates according to the total volume of the first receiver 5A and the second receiver 5B, and the amount of refrigerant circulating is reduced.
  • the control device 20 controls the opening degree of each flow rate adjusting device 6 according to the change in the degree of superheat.
  • the control device 20 determines a change in the degree of superheat based on the temperature of the evaporator 4 detected by the evaporator temperature sensor 22 or the suction temperature sensor 24. Further, the degree of superheat may be obtained based on the temperature on the inlet side of the evaporator 4 and the temperature on the suction side of the compressor 1.
  • the control device 20 When the degree of superheat increases, the control device 20 performs control so that the opening degree of one flow rate adjustment device 6 is increased. For example, when the high pressure side flow rate adjustment device 6A is controlled, the liquid refrigerant accumulated in the first receiver 5A decreases when the opening of the high pressure side flow rate adjustment device 6A increases. As the refrigerant passing through the evaporator 4 increases, the degree of superheat decreases. Further, when the degree of superheat becomes small, the control device 20 performs control so that the opening degree of one flow rate adjustment device 6 becomes small. For example, when the high-pressure flow rate adjustment device 6A is controlled, the liquid refrigerant that accumulates in the first receiver 5A increases as the opening of the high-pressure flow rate adjustment device 6A decreases. As the refrigerant passing through the evaporator 4 decreases, the degree of superheat increases.
  • the three receivers 5 and the two flow rate adjusting devices 6 are provided, but the number of receivers 5 may be two or four or more. Two or three flow rate adjusting devices 6 are provided for the two receivers 5. Three to five flow rate adjusting devices 6 are provided for the four receivers 5. Further, three or four flow rate adjusting devices 6 may be provided for the three receivers 5. The receiver 5 and the flow rate adjusting device 6 are alternately arranged in the flow direction of the refrigerant. The amount of refrigerant that can be controlled can be increased or decreased by the number of receivers 5 and the number of flow control devices 6. The larger the number, the more various refrigerant amounts can be adjusted.
  • the indoor heat exchanger 13 installed in the indoor unit 10 and the outdoor heat exchanger 14 installed in the outdoor unit 11 may have different volumes. Due to the different volumes, the optimum refrigerant amount varies depending on the operation mode.
  • the volume of the outdoor heat exchanger 14 is larger than the volume of the indoor heat exchanger 13
  • the optimum refrigerant amount in the cooling mode is larger than the optimum refrigerant amount in the heating mode.
  • the volume of the indoor heat exchanger 13 is larger than the volume of the outdoor heat exchanger 14, the optimum refrigerant amount in the heating mode is larger than the optimum refrigerant amount in the cooling mode.
  • control device 20 determines whether to increase or decrease the amount of refrigerant circulating during the air conditioning operation. And the control apparatus 20 controls the flow volume adjustment apparatus 6 so that it may become the optimal refrigerant
  • the other configurations and operations except for the indoor and outdoor heat exchangers 13 and 14 are the same as those in the first embodiment.
  • the control device 20 controls the high pressure side flow rate adjustment device 6A and fully opens the low pressure side flow rate adjustment device 6B.
  • the refrigerant accumulates in the first receiver 5A, and no refrigerant accumulates in the second and third receivers 5B and 5C. Thereby, the amount of circulating refrigerant can be increased.
  • the control device 20 controls the low pressure side flow rate adjustment device 6B and fully opens the high pressure side flow rate adjustment device 6A
  • the refrigerant accumulates in the first and second receivers 5A and 5B
  • the third receiver 5C receives the refrigerant. Will not accumulate. At this time, the amount of circulating refrigerant decreases.
  • the outdoor heat exchanger 14 becomes the condenser 2 and the indoor heat exchanger 13 becomes the evaporator 4.
  • the indoor heat exchanger 13 becomes the condenser 2 and the outdoor heat exchanger 14 becomes the evaporator 4.
  • the flow rate adjusting device 6 on the side close to the condenser 2 is controlled, and the flow rate adjusting device 6 on the side close to the evaporator 4 is fully opened, so that the amount of the circulating refrigerant increases.
  • the high pressure side flow rate adjustment device 6A is controlled and the low pressure side flow rate adjustment device 6B is fully opened.
  • An amount of refrigerant can be circulated, and efficient air-conditioning operation can be performed.
  • the flow of the refrigerant circulating in the refrigerant circuit is reversed between the cooling mode and the heating mode. For example, in the refrigerant circuit shown in FIG. 2, if the high-pressure flow rate adjustment device 6a is controlled and the low-pressure flow rate adjustment device 6b is fully opened, the liquid refrigerant accumulates in the receiver 5a during the cooling mode. Liquid refrigerant accumulates in 5c.
  • the volume of the receiver 5a is preferably smaller than the volume of the receiver 5c.
  • the volume of the receiver 5c is preferably smaller than the volume of the receiver 5a.
  • the control device 20 controls the first flow rate adjusting device 6a, 2 Fully open the flow rate adjusting device 6b. Liquid refrigerant accumulates only in the first receiver 5a, and the amount of refrigerant circulating in the refrigerant circuit increases. In the heating mode, the control device 20 controls the first flow rate adjusting device 6a and fully opens the second flow rate adjusting device 6b. Liquid refrigerant accumulates in the second and third receivers 5b and 5c, and the amount of refrigerant circulating in the refrigerant circuit decreases. The amount of refrigerant circulating in the cooling mode is larger than the amount of refrigerant circulating in the heating mode.
  • the control device 20 controls the second flow rate adjustment device 6b to fully open the first flow rate adjustment device 6a.
  • Liquid refrigerant accumulates in the first and second receivers 5a and 5b, and the amount of refrigerant circulating in the refrigerant circuit decreases.
  • the control device 20 controls the second flow rate adjusting device 6b to fully open the first flow rate adjusting device 6a.
  • Liquid refrigerant accumulates only in the third receiver 5c, and the amount of refrigerant circulating in the refrigerant circuit increases. The amount of refrigerant circulating in the heating mode is larger than the amount of refrigerant circulating in the cooling mode.
  • the receivers are first and second receivers 5A and 5B
  • the high-pressure flow rate adjustment device 6A is disposed upstream of the first receiver 5A
  • the second A low pressure side flow rate adjusting device 6B is arranged upstream of the receiver 5B.
  • the low pressure side flow rate adjusting device 6B is located between the first receiver 5A and the second receiver 5B.
  • Other configurations and operations excluding the receiver 5 are the same as those in the first embodiment.
  • the control device 20 controls the high pressure side flow rate adjustment device 6A and fully opens the low pressure side flow rate adjustment device 6B, the refrigerant does not enter and exit the first and second receivers 5A and 5B.
  • the control device 20 controls the low pressure side flow rate adjustment device 6B and fully opens the high pressure side flow rate adjustment device 6A, the liquid refrigerant accumulates in the first receiver 5A.
  • the liquid refrigerant accumulates in the receiver 5 located on the upstream side of the flow rate adjusting device 6. That is, the amount of refrigerant that accumulates in the receiver 5 when the downstream flow rate adjustment device 6 operates is greater than the amount of refrigerant that accumulates in the receiver 5 when the upstream flow rate adjustment device 6 operates. Therefore, the amount of refrigerant that circulates when the high-pressure flow rate adjustment device 6A is controlled is larger than the amount of refrigerant that circulates when the low-pressure flow rate adjustment device 6B is controlled. Therefore, it is possible to adjust the amount of refrigerant circulating in the refrigerant circuit according to the flow rate adjusting device 6 to be operated, and it is possible to set the optimum amount of refrigerant according to the operation state.
  • the optimum refrigerant amount varies depending on the operation mode.
  • the volume of the outdoor heat exchanger 14 is larger than the volume of the indoor heat exchanger 13
  • the optimum refrigerant amount in the cooling mode is larger than the optimum refrigerant amount in the heating mode. Therefore, as shown in FIG. 7, the first receiver 5a is arranged on the outdoor heat exchanger 14 side, and the second receiver 5b is arranged on the indoor heat exchanger 13 side.
  • the first flow rate adjusting device 6a is arranged between the first receiver 5a and the outdoor heat exchanger 14, and the second flow rate adjusting device 6b is arranged between the first receiver 5a and the second receiver 5b.
  • the control device 20 controls the first flow rate adjustment device 6a and fully opens the second flow rate adjustment device 6b in the cooling mode, the refrigerant does not enter and exit the first and second receivers 5a and 5b.
  • the amount of circulating refrigerant becomes large.
  • the control device 20 controls the second flow rate adjusting device 6b and fully opens the first flow rate adjusting device 6a, the liquid refrigerant is accumulated in the first receiver 5a, and no refrigerant is accumulated in the second receiver 5b.
  • the amount of circulating refrigerant is medium.
  • liquid refrigerant accumulates in the first and second receivers 5a and 5b.
  • the amount of circulating refrigerant is small.
  • the control device 20 controls the second flow rate adjusting device 6b and fully opens the first flow rate adjusting device 6a, the liquid refrigerant is accumulated in the second receiver 5b, and no refrigerant is accumulated in the first receiver 5a.
  • the amount of circulating refrigerant is medium. Therefore, the amount of refrigerant circulating in the cooling mode can be made larger than the amount of refrigerant circulating in the heating mode.
  • the 1st receiver 5a is distribute
  • the 2nd receiver 5b is distribute
  • the first flow rate adjusting device 6a is arranged between the first receiver 5a and the second receiver 5b
  • the second flow rate adjusting device 6b is arranged between the first receiver 5a and the indoor heat exchanger 13.
  • the control device 20 controls the first flow rate adjusting device 6a and fully opens the second flow rate adjusting device 6b, liquid refrigerant accumulates in the second receiver 5b, and no refrigerant accumulates in the first receiver 5a. Absent.
  • the amount of circulating refrigerant is medium.
  • the control device 20 controls the second flow rate adjusting device 6b and fully opens the first flow rate adjusting device 6a, no refrigerant accumulates in the first and second receivers 5a and 5b.
  • the amount of circulating refrigerant becomes large. Therefore, the amount of refrigerant circulating in the heating mode can be made larger than the amount of refrigerant circulating in the cooling mode.
  • the volumes of the plurality of receivers 5 are the same, but in the present embodiment, the volumes of the receivers 5 are different.
  • the volume of the first receiver 5A is A
  • the volume of the second receiver 5B is B
  • the volume of the third receiver 5C is C.
  • A, B, and C are different values.
  • Other configurations and operations are the same as those in the first embodiment.
  • the control device 20 controls the high pressure side flow rate adjustment device 6a and fully opens the low pressure side flow rate adjustment device 6b, the liquid refrigerant is accumulated in the first receiver 5A, and the second and third receivers 5B and 5C have no refrigerant. I do not collect.
  • the maximum amount of refrigerant accumulated in the receiver 5 is A.
  • the control device 20 controls the low pressure side flow rate adjustment device 6B and fully opens the high pressure side flow rate adjustment device 6A, liquid refrigerant is accumulated in the first and second receivers 5A and 5B, and the refrigerant is stored in the third receiver 5C. I do not collect.
  • the maximum amount of refrigerant accumulated in the receiver 5 is A + B.
  • the amount of refrigerant circulating in the refrigerant circuit can be finely adjusted according to the flow rate adjusting device 6 to be operated, and the optimum amount of refrigerant according to the operating condition can be obtained.
  • the volume of the first receiver 5a is A
  • the volume of the second receiver 5b is B
  • the volume of the third receiver 5c is C.
  • the control device 20 controls the first flow rate adjusting device 6a and fully opens the second flow rate adjusting device 6b
  • liquid refrigerant accumulates in the first receiver 5a.
  • the maximum amount of refrigerant accumulated in the receiver 5 is A.
  • the control device 20 controls the second flow rate adjustment device 6b and fully opens the first flow rate adjustment device 6a
  • liquid refrigerant accumulates in the first and second receivers 5a and 5b.
  • the maximum amount of refrigerant accumulated in the receiver 5 is A + B.
  • the volume of the receiver 5 positioned on the upstream side in the refrigerant flow direction is set smaller than the volume of the other receivers 5 positioned on the downstream side.
  • Other configurations and operations are the same as those in the first embodiment.
  • the volume of the receiver 5 at a position close to the condenser 2 is minimized, and the receiver 5 at a position close to the evaporator 4.
  • the volume of is maximized. For example, as shown in FIG. 1, when there are three receivers 5, the volume of the first receiver 5A on the upstream side is small, the volume of the second receiver 5B is medium, and the volume of the third receiver 5C on the downstream side is large. Become.
  • the refrigerant When the high pressure side flow rate adjustment device 6A is controlled and the low pressure side flow rate adjustment device 6B is fully opened, the refrigerant accumulates in the first receiver 5A. When the low pressure side flow rate adjusting device 6B is controlled and the high pressure side flow rate adjusting device 6A is fully opened, the refrigerant accumulates in the first and second receivers 5A and 5B. In any case, the refrigerant does not accumulate in the downstream receiver 5. Since the receiver 5 in which the refrigerant is stored becomes a receiver 5 having a small and medium volume, the amount of refrigerant stored in all the receivers 5 is smaller than that in the receiver 5 having a large volume, and the amount of refrigerant circulating in the refrigerant circuit is small. Become more.
  • the refrigerant tends to accumulate in the receiver 5.
  • the volume of the receiver 5 on the high pressure side should be small in order to avoid excessive accumulation of refrigerant. Therefore, providing the receiver 5 with a small volume at a position close to the condenser 2 is a suitable arrangement when increasing the amount of refrigerant to be circulated.
  • the optimum amount of refrigerant circulating through the refrigerant circuit varies depending on the operating conditions.
  • the amount of refrigerant accumulated in all the receivers 5 can be easily calculated according to the flow rate adjusting device 6 to be controlled. Therefore, it is possible to easily control each flow rate adjusting device 6 for optimizing the circulating refrigerant amount.
  • the volume of the indoor and outdoor heat exchangers 13 and 14 is determined at the time of installation. Based on the volume of each of the heat exchangers 13 and 14, it is determined whether a large amount of circulating refrigerant is necessary in the cooling mode or in the heating mode. Based on this, the arrangement order of the receivers 5 having different volumes is determined.
  • the volume of the outdoor heat exchanger 14 is larger than the volume of the indoor heat exchanger 13
  • the amount of refrigerant required in the cooling mode is larger than that in the heating mode.
  • the volume of the first receiver 5a is small
  • the volume of the second receiver 5b is medium
  • the volume of the third receiver 5c is large.
  • the liquid refrigerant is accumulated in the first receiver 5a.
  • the second flow rate adjusting device 6b is controlled and the first flow rate adjusting device 6a is fully opened, liquid refrigerant accumulates in the first and second receivers 5a and 5b. In any case, no refrigerant accumulates in the third receiver 5c.
  • liquid refrigerant In the cooling mode, liquid refrigerant accumulates in the receiver 5 having a small and medium volume, and in the heating mode, liquid refrigerant accumulates in the receiver 5 having a medium and large volume. Therefore, the amount of refrigerant stored in the receiver 5 is large during the heating mode, decreases during the cooling mode, and the amount of refrigerant circulating in the refrigerant circuit during the cooling mode is greater than during the heating mode.
  • the volume of the indoor heat exchanger 13 is larger than the volume of the outdoor heat exchanger 14, the amount of refrigerant required in the heating mode is larger than that in the cooling mode.
  • the volume of the third receiver 5c is small, the volume of the second receiver 5b is medium, and the volume of the first receiver 5a is large.
  • liquid refrigerant In the heating mode, liquid refrigerant accumulates in the receiver 5 having a small and medium volume, and in the cooling mode, liquid refrigerant accumulates in the receiver 5 having a medium and large volume. Therefore, the amount of refrigerant stored in the receiver 5 is large in the cooling mode, decreases in the heating mode, and the amount of refrigerant circulating in the refrigerant circuit in the heating mode is larger than in the cooling mode.
  • the volume of the first receiver 5a shown in FIG. 7 is small and the volume of the second receiver 5b is large. It is said.
  • the cooling mode when the second flow rate adjusting device 6b is controlled and the first flow rate adjusting device 6a is fully opened, liquid refrigerant is accumulated in the first receiver 5a.
  • the first flow rate adjusting device 6a is controlled and the second flow rate adjusting device 6b is fully opened, no refrigerant accumulates in each receiver 5a, 5b.
  • the heating mode when the second flow rate adjusting device 6b is controlled and the first flow rate adjusting device 6a is fully opened, the liquid refrigerant is accumulated in the second receiver 5b.
  • the first flow rate adjusting device 6a is controlled and the second flow rate adjusting device 6b is fully opened, liquid refrigerant accumulates in the first and second receivers 5a and 5b. Even in this case, the amount of refrigerant circulating in the refrigerant circuit in the cooling mode is larger than that in the heating mode.
  • the volume of the indoor heat exchanger 13 is larger than the volume of the outdoor heat exchanger 14, the volume of the second receiver 5b shown in FIG. 8 is small and the volume of the first receiver 5a is large.
  • the liquid refrigerant is accumulated in the second receiver 5b.
  • the second flow rate adjusting device 6b is controlled and the first flow rate adjusting device 6a is fully opened, liquid refrigerant accumulates in the first and second receivers 5a and 5b.
  • the heating mode when the second flow rate adjusting device 6b is controlled and the first flow rate adjusting device 6a is fully opened, no refrigerant accumulates in each receiver 5a, 5b.
  • the first flow control device 6a is controlled and the second flow control device 6b is fully opened, the liquid refrigerant is accumulated in the second receiver 5b. Even in this case, the amount of refrigerant circulating in the refrigerant circuit in the heating mode is larger than that in the cooling mode.
  • the flow rate adjusting device is controlled in accordance with an operation state such as a change in superheat degree. According to the control of the flow rate adjusting device 6, the amount of refrigerant accumulated in the receiver 5 varies, and the refrigerant circulating in the refrigerant circuit is adjusted. When the flow control device 6 is fully opened, the amount of refrigerant passing through the flow control device 6 increases.
  • a pressure loss occurs when the refrigerant passes through the flow control device 6.
  • the pressure loss also increases.
  • the pressure loss increases, the refrigerant hardly flows into the evaporator 4 and the degree of superheat increases. Therefore, the discharge temperature from the compressor 1 rises, the air conditioning capability is insufficient, and the operation efficiency is deteriorated.
  • the refrigerant flowing into the evaporator 4 can be increased by increasing the opening degree of the flow rate adjusting device 6.
  • the flow rate adjusting device 6 is made controllable by adjusting the rotation speed of the compressor 1 so that the refrigerant amount can be adjusted. That is, when the opening degree of the plurality of flow rate adjusting devices 6 becomes equal to or larger than the predetermined opening degree, the control device 20 decreases the rotational speed of the compressor 1.
  • two flow control devices 6a and 6b are provided between the outdoor heat exchanger 14 and the indoor heat exchanger 13 of the refrigerant circuit, and the first flow control device 6a and the second flow control device 6b. Between the two, one receiver 5 is provided.
  • the other configurations and operations are the same as those in the above embodiments except that there is one receiver 5.
  • the control device 20 controls each flow rate adjusting device 6 after confirming that the refrigeration cycle is stable. For example, in the cooling mode, the second flow rate adjusting device 6b is fully opened, and the opening degree of the first flow rate adjusting device 6a is set to the set opening degree. And the 1st flow regulating device 6a is controlled according to an operation situation.
  • the control device 20 controls the first flow rate adjusting device 6a so that the opening degree of the first flow rate adjusting device 6a increases. The amount of refrigerant passing through the first flow rate adjusting device 6a increases, the amount of refrigerant flowing into the indoor heat exchanger 13 increases, and the degree of superheat decreases.
  • control device 20 changes the opening degree of the flow rate adjusting device 6 according to the operating condition such as the degree of superheat in order to adjust the circulating refrigerant amount, but the refrigerant amount is adjusted by the control of the flow rate adjusting device 6. Determine if it is possible.
  • the control device 20 checks whether the opening degree of the first and second flow rate adjusting devices 6a and 6b is equal to or larger than a predetermined opening degree (S1).
  • the predetermined opening is an opening close to full opening, and is set to 80%, for example.
  • the opening degree of the 2nd flow volume adjustment apparatus 6b should just be more than a predetermined opening degree.
  • the control device 20 determines that it is impossible to adjust the refrigerant amount under the control of the flow rate adjusting device 6, and the rotation of the compressor 1
  • the compressor 1 is controlled so as to decrease the number (S2). For example, the rotation speed of the compressor 1 is reduced by 500 rpm.
  • the control device 20 changes the opening degree of the first flow rate adjusting device 6a according to the rotational speed of the compressor 1 (S3).
  • the opening degree of the first flow rate adjusting device 6a becomes an opening degree corresponding to the reduced rotational speed, and the opening degree of the first flow rate adjusting device 6a becomes small.
  • the control device 20 checks whether the changed opening is equal to or greater than a predetermined opening (S2). When the opening degree is equal to or greater than the predetermined opening degree, the control device 20 controls the compressor 1 again to lower the rotational speed of the compressor 1 by, for example, 500 rpm. As the rotational speed of the compressor 1 decreases, the opening of the first flow rate adjusting device 6a is changed to be smaller.
  • the controller 20 checks whether or not the room temperature has become higher than the set temperature after a certain time has passed ( S4).
  • the control device 20 controls the compressor 1 so as to increase the rotational speed of the compressor 1 (S5).
  • the rotation speed of the compressor 1 is increased by 500 rpm.
  • the control apparatus 20 changes the opening degree of the 1st flow volume adjustment apparatus 6a according to the rotation speed of the compressor 1 (S6).
  • the opening degree of the first flow rate adjusting device 6a is an opening degree corresponding to the increased rotational speed of the compressor 1, and the opening degree of the first flow rate adjusting device 6a is increased. Thereafter, the control device 20 checks whether the opening degree of the first and second flow rate adjusting devices 6a and 6b is equal to or larger than a predetermined opening degree (S1).
  • the flow rate adjusting device 6 When the air conditioning load is large, even if each flow rate adjusting device 6 becomes fully open or close to full open and cannot be controlled any more, the number of rotations of the compressor 1 is decreased, so that the number of rotations of the compressor 1 is reduced. The optimum amount of refrigerant is reduced. Accordingly, the flow rate adjusting device 6 has an opening degree corresponding to the reduced rotational speed, and the opening amount of the first flow rate adjusting device 6a becomes small, so that the flow rate adjusting device 6 can be controlled. That is, when the degree of superheat increases, the opening degree of the flow rate adjusting device 6 can be increased by the above control.
  • the liquid refrigerant accumulated in the receiver 5 is discharged to the refrigerant circuit, and the amount of circulating refrigerant increases and the degree of superheat can be reduced. Therefore, it can be adjusted to the optimum refrigerant amount by the control of the flow rate adjusting device 6.
  • the air conditioning load increases, so the amount of circulating refrigerant must be increased.
  • the flow control device 6 is fully opened, the refrigerant flows into the evaporator 4 due to pressure loss when the refrigerant passes through the flow control device 6, and temperature unevenness occurs in the evaporator 4.
  • a gas refrigerant having substantially the same temperature as room temperature flows into the indoor heat exchanger 13 that is the evaporator 4
  • moisture contained in the sucked indoor air flows to the outlet without being sufficiently condensed in the indoor heat exchanger 13.
  • dew is attached to the wall of the air outlet. The accumulated dew is blown out by the blown wind, and water is scattered from the outlet into the room.
  • the above control is also performed when the air conditioning operation is performed in the heating mode.
  • the flow rate adjusting device 6 can be controlled according to the air conditioning load, and can be adjusted to the optimum refrigerant amount. Further, when there are a plurality of flow rate adjusting devices 6, the pressure loss is larger than when there is one flow rate adjusting device 6, but by performing the same control as described above, it is possible to eliminate the shortage of the refrigerant amount, Efficient air conditioning operation can be performed.
  • the control device 20 controls the first and second flow rate adjusting devices 6a and 6b based on the change in the degree of superheat.
  • the second flow rate adjusting device 6b is fully opened, and the opening degree of the first flow rate adjusting device 6a changes.
  • the first flow rate adjusting device 6a is fully opened (S11).
  • the control device 20 confirms that the opening degree of each of the flow rate adjusting devices 6a and 6b is not less than a predetermined opening degree, for example, 80% or more, starts dew prevention control, and sets the rotation speed of the compressor 1.
  • the compressor 1 is controlled to be lowered (S12).
  • the control apparatus 20 controls the fan 15 so that the rotation speed of the fan 15 for outdoor heat exchangers may be lowered
  • the opening degree of the first flow rate adjusting device 6a becomes small.
  • the optimum amount of refrigerant also decreases according to the rotational speed of the compressor 1. Since the first flow rate adjustment device 6a can be controlled so that the opening degree can be increased, the opening degree of the first flow rate adjustment device 6a can be increased even if the air conditioning load is large.
  • the amount of circulating refrigerant increases, and the amount of refrigerant can be optimally adjusted even in a situation where the air conditioning load is large. As a result, the shortage of refrigerant in the indoor heat exchanger 13 can be solved, temperature unevenness does not occur in the indoor heat exchanger 13, and dew condensation can be prevented.
  • the rotation speed of the fan 15 for the outdoor heat exchanger is decreased, so that the wind speed toward the outdoor heat exchanger 14 is weakened, and the heat radiation of the refrigerant in the outdoor heat exchanger 14 is reduced.
  • the amount of refrigerant that accumulates in the outdoor heat exchanger 14 increases, and the shortage of refrigerant can be compensated.
  • the amount of circulating refrigerant can be increased. That is, even if the amount of decrease in the rotational speed of the compressor 1 is reduced, it is possible to secure an amount of refrigerant that can solve the shortage of refrigerant.
  • the air conditioning capacity is proportional to the rotational speed of the compressor 1, the smaller the decrease in the rotational speed of the compressor 1, the lower the decrease in the air conditioning capacity. Therefore, sufficient refrigerant flows through the indoor heat exchanger 13, the degree of superheat can be reduced, and the air conditioning operation can be performed efficiently even when the air conditioning load is large.
  • the control device 20 determines that the amount of circulating refrigerant is large and starts dew prevention control. Instead, when the air conditioning load is large, the control device 20 may detect that the amount of circulating refrigerant is large and perform dew prevention control. That is, in the cooling mode, the control device 20 detects the outside air temperature and the temperature of the indoor heat exchanger 13, and determines whether the amount of the circulating refrigerant is large based on these information.
  • the control device 20 When the outside air temperature is equal to or higher than the predetermined temperature and the temperature of the evaporator 4 (indoor heat exchanger 13) or the discharge temperature or the suction temperature of the compressor 1 is equal to or higher than the predetermined temperature, the control device 20 has a large amount of refrigerant to circulate. It is judged that. When this state is reached, the opening degree of each flow rate adjusting device 6 is greater than or equal to a predetermined opening degree.
  • the degree of superheat increases and the opening degree of the flow rate adjusting device 6 becomes fully open or close to full open, only the rotational speed of the fan for the condenser 2 may be lowered. Since the heat exchange capability of the condenser 2 is reduced, the amount of refrigerant accumulated in the condenser 2 is reduced, and the amount of circulating refrigerant can be increased. Therefore, not only in the cooling mode but also in the heating mode, the circulating refrigerant amount can be adjusted without opening the flow rate adjusting device 6 to near full open. In addition, you may make it reduce the rotation speed of the fan for the condenser 2 simultaneously with the rotation speed of the compressor 1 falling. Thereby, not only in the cooling mode but also in the heating mode, the amount of circulating refrigerant can be adjusted without opening the flow rate adjusting device 6 to near full open.
  • the refrigerant circulating in the refrigerant circuit enters and exits the receiver 5 through the connecting pipe 8 connected to the connection pipe 7 of the refrigerant circuit.
  • the refrigerant enters the receiver 5 from the connecting pipe 8 and accumulates, or the accumulated refrigerant is discharged from the receiver 5.
  • the refrigerant cannot smoothly enter and exit from the receiver 5 only with this pressure difference.
  • the temperature of the receiver 5 is higher than the temperature of the refrigerant, the pressure in the receiver 5 increases, the refrigerant becomes difficult to flow into the receiver 5, and the refrigerant does not accumulate.
  • the pressure in the receiver 5 decreases, the refrigerant becomes difficult to get out of the receiver 5, and the refrigerant in the receiver 5 does not decrease.
  • the receiver 5 is warmed or cooled so that the refrigerant can smoothly enter and exit the receiver 5.
  • a cooling pipe 30 that cools the receiver 5 by diverting a low-temperature refrigerant from the refrigerant circuit, and a heating pipe 31 that warms the receiver 5 by diverting a high-temperature refrigerant from the refrigerant circuit are provided. It is done.
  • the heating pipe 31 is connected to a discharge side pipe of the compressor 1, and the cooling pipe 30 is connected to a suction side pipe of the compressor 1.
  • the cooling pipe 30 and the heating pipe 31 are wound around the receiver 5 so as not to contact each other.
  • Other configurations and operations are the same as those in the above embodiments.
  • the cooling pipe 30 and the heating pipe 31 are each formed from a single capillary tube and have a smaller diameter than the piping of the refrigerant circuit.
  • One end and the other end of the cooling pipe 30 communicate with the piping of the refrigerant circuit, respectively, and cooling valves 32 for opening and closing the cooling pipe 30 are provided on one end side and the other end side, respectively.
  • one end and the other end of the heating pipe 31 communicate with the piping of the refrigerant circuit, respectively, and heating valves 33 for opening and closing the heating pipe 31 are provided on one end side and the other end side, respectively.
  • the cooling valve 32 and the heating valve 33 are controlled by the control device 20 according to the operation status.
  • a low-temperature refrigerant flows through the cooling pipe 30.
  • no refrigerant flows through the cooling pipe 30.
  • a high-temperature refrigerant flows through the heating pipe 31.
  • no refrigerant flows through the heating pipe 31.
  • the control device 20 When storing the refrigerant in the receiver 5, the control device 20 opens the cooling valve 32 and closes the heating valve 33.
  • the low-temperature refrigerant sucked into the compressor 1 flows into the cooling pipe 30 and the receiver 5 is cooled.
  • the gas refrigerant in the receiver 5 is liquefied, the pressure in the receiver 5 is lowered, and the difference between the pressure on the piping side of the refrigerant circuit and the pressure in the receiver 5 is increased. As the pressure difference increases, the refrigerant smoothly flows into the receiver 5 and accumulates quickly. Therefore, the amount of circulating refrigerant can be quickly reduced.
  • the control device 20 When discharging the refrigerant from the receiver 5, the control device 20 closes the cooling valve 32 and opens the heating valve 33.
  • the high-temperature refrigerant discharged from the compressor 1 flows into the heating pipe 31, and the receiver 5 is warmed.
  • the liquid refrigerant in the receiver 5 evaporates, the pressure in the receiver 5 increases, and the difference between the pressure in the receiver 5 and the piping side of the refrigerant circuit increases. As the pressure difference increases, the refrigerant flows out of the receiver 5 smoothly and is discharged quickly. Therefore, the amount of circulating refrigerant can be increased quickly.
  • the cooling pipe 30 and the heating pipe 31 are very thin tubes. Even if the refrigerant flows from the piping of the refrigerant circuit to the respective pipes 30 and 31, the amount of the circulating refrigerant is reduced only slightly. Therefore, the temperature of the receiver 5 can be adjusted without affecting the air conditioning capability. Then, by adjusting the temperature of the receiver 5 in conjunction with the control of the flow rate adjusting device 6, the refrigerant flows into and out of the receiver 5 smoothly, and the amount of circulating refrigerant can be adjusted quickly and optimally.
  • the cooling pipe 30 and the heating pipe 31 may be wound around each receiver 5. Moreover, the cooling valve 32 and the heating valve 33 are kept closed with respect to the receiver 5 in which a refrigerant
  • the receiver 5 is disposed in a gap in the outdoor unit 11.
  • consideration must be given so that the receiver 5 and the connecting pipe 8 do not interfere with the piping and components in the outdoor unit 11.
  • the size and shape of the receiver 5 are determined in order to ensure a predetermined volume of the receiver 5.
  • the outdoor unit 11 there is only a limited gap due to the structure, and in order to arrange the receiver 5 so as not to interfere, the layout of piping and parts is changed, or the outdoor unit 11 is enlarged. Thus, it is necessary to secure a gap in which the receiver 5 can be disposed.
  • the receiver 5 is composed of a plurality of tanks 40 as shown in FIGS.
  • one receiver 5 is composed of three tanks 40.
  • Other configurations and operations are the same as those in the above embodiments.
  • the tank 40 is a cylindrical container, and an entrance is formed on the bottom surface.
  • the tanks 40 have the same shape.
  • the total volume of the three tanks 40 is the same as the volume of one receiver 5.
  • Each tank 40 is located in a gap in the outdoor unit 11 and is shifted and arranged without contacting each other.
  • the three tanks 40 are respectively connected to one connecting pipe 8 through branch pipes 41.
  • a branch pipe 41 is connected to the lower surface of the tank 40, and the branch pipe 41 is connected to the connecting pipe 8.
  • the tank 40 is located higher than the branch pipe 41, and the vertical positions of the branch pipes 41 are different.
  • the refrigerant flows into the connecting pipe 8 from the pipe of the refrigerant circuit and enters the tank 40 through the branch pipe 41 connected to the lowest position. Subsequently, the refrigerant enters the other tank 40 from the branch pipe 41 connected to a position higher than the branch pipe 41. The refrigerant accumulates in order from the tank 40 connected to the branch pipe 41 at the lower position.
  • the refrigerant stored in the tank 40 at the highest position is first discharged.
  • the refrigerant is sequentially discharged from the tank 40 at a high position.
  • the tank 40 is smaller than the receiver 5, the gap that can accommodate the tank 40 may be small. Therefore, the choice of the position where the tank 40 can be arranged increases. Therefore, the receiver 5 can be arranged according to the gap without changing the arrangement of the pipes and components in the outdoor unit 11. Moreover, since it is not necessary to form a large gap for the receiver 5, the outdoor unit 11 can be downsized.
  • the shape of the tank 40 may be changed according to the shape of the gap.
  • the tank 40 is formed in an L shape.
  • each receiver 5 may be configured by a plurality of tanks 40 in the same manner. Note that it is not necessary to configure all the receivers 5 from a plurality of tanks 40. If there is a gap in which the receivers 5 can be installed, the receivers 5 may be used as they are.
  • (Tenth embodiment) In an air conditioner having a receiver 5 for storing refrigerant and a plurality of flow rate adjusting devices 6a and 6b for adjusting the amount of refrigerant stored in the receiver 5 in order to adjust the amount of refrigerant circulating in the refrigerant circuit, as shown in FIG.
  • the control device 20 that controls the flow rate adjusting devices 6a and 6b controls the opening degree of the flow rate adjusting devices 6a and 6b so that the refrigerant amount circulating in the refrigerant circuit becomes the optimum refrigerant amount according to the air conditioning operation.
  • the compressor 1 when the air-conditioning operation is started, the compressor 1 is driven, and the refrigerant circulates through the refrigerant circuit to form a refrigeration cycle.
  • the target rotational speed of the compressor 1 is set based on the set temperature and the room temperature, and the initial opening degree of each flow rate adjusting device 6a, 6b is determined according to the target rotational speed.
  • the flow rate adjusting devices 6a and 6b are opened to the initial opening degree, and the compressor 1 is driven at the target rotational speed.
  • the refrigerant discharged from the compressor 1 circulates through the refrigerant circuit, and after a while, the refrigeration cycle is stabilized. Thereafter, the rotation speed of the compressor 1 is changed according to the room temperature or the outside air temperature, the opening degree of each flow rate adjusting device 6a, 6b is changed according to the rotation speed of the compressor 1, and the amount of circulating refrigerant is optimized. It is adjusted to become.
  • the control device 20 performs refrigerant amount adjustment control after confirming that the refrigeration cycle is stable.
  • the stability of the refrigeration cycle is determined based on whether or not the discharge temperature of the refrigerant from the compressor 1 is equal to or higher than a predetermined temperature.
  • the discharge temperature also changes due to a change in the outside air temperature or a change in the rotation speed of the compressor 1. Therefore, even though the refrigeration cycle is not yet stable, the discharge temperature may reach a predetermined temperature, and an erroneous determination is made. As a result, it takes extra time to reach the optimum refrigerant amount.
  • the control device 20 determines whether or not the refrigeration cycle is stable using a mathematical expression that represents a change in the discharge temperature of the compressor 1 so that it can be strictly determined that the refrigeration cycle is stable. Then, the opening degree of the flow rate adjusting device 6 is controlled after the refrigeration cycle is stabilized. At this time, a plurality of mathematical expressions are prepared using the rotation speed of the compressor 1 as a parameter, and the control device 20 selects a mathematical expression to be used for determination according to the rotation speed of the compressor 1.
  • Judgment of the stability of the refrigeration cycle is made based on the time change of the discharge temperature from the compressor 1.
  • the mathematical formula used for this determination is an approximate formula obtained from the result of measuring the change in discharge temperature over time, and the rotational speed of the compressor 1, the discharge temperature, and the outside air temperature are taken into account in the mathematical formula.
  • the discharge temperature is the surface temperature of the discharge pipe connected to the outlet side of the compressor 1.
  • Fig. 19 shows the flow of stability determination processing.
  • the time change of the discharge temperature of the compressor 1 is actually measured, and the approximate expression A1 is created from the preset numerical expression A and the actual measurement value (S20).
  • This approximate expression A1 is stored in the memory of the control device 20.
  • the control device 20 inputs the detected outside air temperature and the rotation speed of the compressor 1 to the approximate expression A1 (S21).
  • the control device 20 determines whether or not the degree of time change of the temperature difference ⁇ T between the discharge temperature of the compressor 1 and the outside air temperature is within a predetermined value ⁇ (S22).
  • the control device 20 determines that the refrigeration cycle is stable (S23), and performs the stability determination process. finish.
  • Step 1 At the outside air temperature Tout1, the stable discharge temperature when the compressor 1 is rotated at the rotation speeds f1 and f2 and the discharge temperature when the compressor 1 is rotated at the rotation speeds f1 and f2 are measured.
  • FIG. 20A shows the change over time in the discharge temperature at the rotation speeds f1 and f2.
  • the vertical axis represents the temperature difference ⁇ T between the discharge temperature and the outside air temperature, and the horizontal axis represents time t.
  • ⁇ T1 is the stable discharge temperature Td11-Tout at the rotation speed f1
  • ⁇ T2 is the stable discharge temperature Td12-Tout at the rotation speed f2.
  • Tout is an arbitrary outside temperature.
  • the temperature difference function ⁇ T (t) converges to ⁇ T1 and ⁇ T2 with time. Moreover, since discharge temperature becomes high, so that the rotation speed of the compressor 1 is high, the temperature difference when the rotation speed is high becomes larger than the temperature difference when the rotation speed is low.
  • Step 2 Formulas relating to changes in the discharge temperature over time are set in advance and stored in the memory of the control device 20.
  • Formulas A and a are created for each rotation speed.
  • ⁇ T (t) ⁇ T2 + ( ⁇ T1 ⁇ T2) ⁇ (f ⁇ f2) / (f1 ⁇ f2) ⁇ ⁇ ⁇ 1 ⁇ e ( ⁇ t / ⁇ 1) ⁇
  • ⁇ T (t) ⁇ T2 + ( ⁇ T1 ⁇ T2) ⁇ (f ⁇ f2) / (f1 ⁇ f2) ⁇ ⁇ ⁇ 1 ⁇ e ( ⁇ t / ⁇ 2) ⁇
  • FIG. 20C shows a saturation curve of the formula A. It can be seen that the saturation curve changes depending on the rotational speed of the compressor 1.
  • Step 4 When the outside air temperature is Tout2, the stable discharge temperature when the compressor 1 is rotated at the rotation speeds f1 and f2, and the stable discharge temperature Td21 and Td22 when the compressor 1 is rotated at the rotation speeds f1 and f2 are Measured.
  • the outside air temperature affects the discharge temperature. Therefore, by correcting ⁇ T1 and ⁇ T2 in the expressions A and a based on the change degree of the discharge temperature due to the outside air temperature, the influence of the outside air temperature can be eliminated, and an accurate approximate expression for the time change of the discharge temperature can be obtained. It is done.
  • Step 5 The measurement result at the rotation speed f1 in step 4 is substituted into equation B. Further, the measurement result at the rotation speed f2 is substituted into the expression C.
  • ⁇ T1 Td11 + (Td21 ⁇ Td11) ⁇ (Tout ⁇ Tout1) / (Tout2 ⁇ Tout1) ⁇ Tout1 Expression
  • ⁇ T2 Td12 + (Td22 ⁇ Td12) ⁇ (Tout ⁇ Tout1) / (Tout2 ⁇ Tout1) ⁇ Tout1 Expression C
  • Expressions B and C are substituted into Expression A and Expression a, respectively, and approximate expressions A1 and a1 are obtained.
  • ⁇ T (t) ⁇ T2 + ( ⁇ T1 ⁇ T2) ⁇ (f ⁇ f2) / (f1 ⁇ f2) ⁇ ⁇ ⁇ 1 ⁇ e ( ⁇ t / ⁇ 2) ⁇ (Expression a1)
  • Expressions B and C are used for ⁇ T1 and ⁇ T2 in the above expressions.
  • FIG. 21A shows that the discharge temperature saturation curve changes depending on the outside air temperature.
  • the two approximate expressions obtained as described above correspond to the rotation speed of the compressor 1. That is, the approximate expression a1 corresponds to a high rotation range where the rotation speed of the compressor 1 is higher than the predetermined rotation speed, and the approximate expression A1 corresponds to a low rotation speed range lower than the predetermined rotation speed.
  • control device 20 substitutes the rotation speed of the compressor 1 and the detected outside air temperature into one of the approximate equations selected from the two approximate equations, and each time since the start of the operation. Calculate the temperature difference.
  • the rotational speed of the compressor 1 is acquired by detecting the rotational speed of the motor of the compressor 1 or is acquired based on the operating frequency output when the compressor 1 is driven.
  • control apparatus 20 calculates the timing when the change of the calculated temperature difference becomes small. It is determined that the timing at which the change in the temperature difference becomes small is when the refrigeration cycle is stabilized. The control device 20 derives the time when this timing is reached from the approximate expression. This time is defined as a stabilization time required from the start of operation to stabilization. The control device 20 determines that the refrigeration cycle is stable when the stable time is reached after starting the operation, and performs refrigerant amount adjustment control.
  • the control device 20 performs the calculation again to correct the stabilization time.
  • the stabilization time is similarly corrected.
  • the refrigeration cycle is stable when the time change rate of ⁇ T (t) becomes smaller than the threshold ⁇ .
  • the threshold ⁇ is, for example, ⁇ 0.1 ° C./min. This threshold value is merely an example, and is not limited to this.
  • one of the two approximate expressions is selected according to the rotational speed of the compressor 1.
  • One approximate expression a1 corresponds to the high rotation range
  • the other approximate expression A1 corresponds to the low rotation range.
  • the control device 20 determines whether the rotation speed during operation is in a high rotation range or a low rotation range, and selects an approximate expression corresponding to the rotation range. In this way, a more rigorous determination can be made by properly using the approximate expression used for the determination of stability according to the rotational speed of the compressor 1.
  • the determination of stability is not performed based on the discharge temperature of the compressor 1 detected during operation. Therefore, the stability can be determined without being influenced by the actual change in the discharge temperature, and the reliability of the determination is increased.
  • the number of approximate expressions used for determination may be two or more.
  • a plurality of rotation ranges are set with respect to the rotation speed of the compressor 1, and a plurality of approximate expressions correspond to the respective rotation ranges.
  • An approximate expression is selected according to the rotation range to which the rotation speed during operation belongs.
  • the number of receivers 5 is not limited to one, and a plurality of receivers 5 may be used.
  • the air conditioner of the present invention includes a refrigerant circuit in which the compressor 1, the condenser 2, the throttle unit 3, and the evaporator 4 are connected by piping.
  • the throttling unit 3 includes a plurality of receivers 5 that store refrigerant and a plurality of flow rate adjusting devices 6 that adjust the amount of refrigerant stored in each receiver 5 in order to adjust the amount of refrigerant circulating in the refrigerant circuit.
  • the amount of refrigerant circulating in the refrigerant circuit varies depending on the amount of refrigerant accumulated in each receiver 5. Therefore, by operating the flow rate adjusting device 6 according to the operating state, the refrigerant amount accumulated in each receiver 5 is adjusted, and the optimum refrigerant amount according to the operating state can be obtained.
  • a plurality of flow rate adjusting devices 6 are arranged in series in the refrigerant circuit, a receiver 5 is connected between the adjacent flow rate adjusting devices 6, and the flow rate adjusting device 6 located downstream of the receiver 5 in the refrigerant flow direction operates. As a result, the amount of refrigerant accumulated in the receiver 5 changes.
  • the amount of refrigerant collected in the receiver 5 located on the downstream side can be adjusted by the operation of the flow rate adjusting device 6, and no refrigerant accumulates in the receiver 6 located on the upstream side.
  • the plurality of flow rate adjusting devices 6 it is possible to adjust the amount of refrigerant accumulated for each receiver 5, and the amount of circulating refrigerant can be set to an optimum amount according to the operation state.
  • a control device 20 for controlling the opening degree of the flow rate adjusting device 6 is provided, and the control device 20 controls the opening degree of at least one flow rate adjusting device 6 to fully open the other flow rate adjusting device 6.
  • the amount of refrigerant accumulated in the receiver 5 located on the downstream side of the flow rate adjusting device 6 to be controlled can be adjusted, and no refrigerant accumulates in the receiver 5 located on the upstream side. Therefore, the receiver 5 in which the refrigerant accumulates is determined according to the flow rate adjustment device 6 to be controlled, and the amount of refrigerant accumulated in all the receivers 5 is changed by controlling the flow rate adjustment device 6 as the control object according to the operation status, and is circulated.
  • the amount of refrigerant to be made can be made the optimum amount of refrigerant.
  • control device 20 controls the flow rate adjustment device 6 to be controlled after fully opening the flow rate adjustment device 6 other than the control target.
  • each receiver 5 is different.
  • the volume of at least one receiver 5 among the plurality of receivers 5 may be different.
  • the volume of the indoor heat exchanger 13 is larger than the volume of the outdoor heat exchanger 14.
  • the volume of the receiver 5 near the outdoor heat exchanger 14 is smaller than the volume of the receiver 5 near the indoor heat exchanger 13
  • the volume of the outdoor heat exchanger 14 is smaller than the volume of the indoor heat exchanger 13
  • the volume of the receiver 5 close to the outdoor heat exchanger 14 is made larger than the volume of the receiver 5 close to the indoor heat exchanger 13.
  • the volume of the receiver 5 provided near the condenser 2 is made smaller than the volume of the other receivers 5.
  • the amount of the circulating refrigerant can be increased.
  • the refrigerant accumulated in the receiver 5 having a small volume can be quickly adjusted by controlling the flow rate adjusting device 6 on the upstream side of the receiver 5 located near the condenser 2. Therefore, it is possible to easily increase the amount of refrigerant circulating.
  • the volume of the receiver 5 positioned on the upstream side in the refrigerant flow direction is smaller than the volume of the receiver 5 positioned on the downstream side. That is, the receivers 5 are arranged in ascending order of volume from the upstream side toward the downstream side. Thereby, control of each flow control device 6 for optimizing the amount of circulating refrigerant can be easily performed.
  • the receiver 5 includes a single inlet / outlet, a connecting pipe 8 branched from the refrigerant circuit is connected to the inlet / outlet of the receiver 5, and the connecting pipe 8 is disposed between the adjacent flow rate adjusting devices 6. Compared to the case where the inlet and outlet of the receiver 5 are separated, only one connecting pipe 8 is required. For this reason, even if there are a plurality of receivers 5, the number of pipes does not increase and the installation space for the receiver 5 can be easily secured.
  • the compressor 1, the condenser 2, the throttle unit 3, and the evaporator 4 are provided with a refrigerant circuit that is connected by piping, and the throttle unit 3 adjusts the amount of refrigerant that circulates in the refrigerant circuit and the receiver 5 that stores the refrigerant.
  • the flow rate adjusting device 6 is configured so that the amount of refrigerant circulating in the refrigerant circuit becomes the optimum amount of refrigerant according to the air conditioning operation.
  • the control device 20 to be controlled is provided and the opening amounts of the plurality of flow rate adjusting devices 6 are equal to or greater than a predetermined opening amount, the control device 20 decreases the rotational speed of the compressor 1.
  • the control device 20 sets the flow rate adjustment device 6 other than the control target to a predetermined opening degree or more, and then controls the control target flow rate adjustment device 6 to the predetermined opening degree or more.
  • the compressor 1, the condenser 2, the throttle unit 3, and the evaporator 4 are provided with a refrigerant circuit that is connected by piping, and the throttle unit 3 adjusts the amount of refrigerant that circulates in the refrigerant circuit and the receiver 5 that stores the refrigerant.
  • the flow rate adjusting device 6 is configured so that the amount of refrigerant circulating in the refrigerant circuit becomes the optimum amount of refrigerant according to the air conditioning operation.
  • a control device 20 for controlling is provided, and the control device 20 blows air toward the condenser 2 when the opening degree of the plurality of flow rate adjustment devices 6 is set to a predetermined opening degree or more and the rotational speed of the compressor 1 is reduced. The rotational speed of the fan 15 is lowered.
  • the rotation speed of the compressor 1 is reduced and the rotation speed of the condenser fan 15 is further reduced in order to prevent dew condensation due to insufficient refrigerant. Be lowered.
  • the amount of circulating refrigerant can be increased. The shortage of refrigerant can be quickly resolved and dew can be prevented.
  • the compressor 1, the condenser 2, the throttle unit 3, and the evaporator 4 are provided with a refrigerant circuit that is connected by piping, and the throttle unit 3 adjusts the amount of refrigerant that circulates in the refrigerant circuit and the receiver 5 that stores the refrigerant.
  • a heating tube 31 that warms the receiver 5.
  • the refrigerant When the receiver 5 is cooled by the low-temperature refrigerant, the refrigerant easily flows into the receiver 5. When the receiver 5 is warmed by the high-temperature refrigerant, the refrigerant is easily discharged from the receiver 5. As a result, the refrigerant smoothly enters and exits the receiver 5.
  • a cooling valve 32 that opens and closes the cooling pipe 30 and a heating valve 33 that opens and closes the heating pipe 31 are provided.
  • the cooling valve 32 is opened and the heating valve 33 is closed. Is discharged, the cooling valve 32 is closed and the heating valve 33 is opened.
  • the control device 20 controls the cooling valve 32 and the heating valve 33 according to the operation status.
  • the cooling valve 32 and the heating valve 33 in conjunction with the flow rate adjusting device 6, the refrigerant flows in and out of the receiver 5 smoothly, and the amount of circulating refrigerant can be quickly adjusted.
  • the heating pipe 31 is connected to the discharge side piping of the compressor 1, and the cooling pipe 30 is connected to the suction side piping of the compressor 1. Since the temperature of the refrigerant flowing through the heating pipe 31 is higher than the temperature of the refrigerant in the receiver 5, the liquid refrigerant in the receiver 5 can be evaporated to increase the internal pressure, and the refrigerant is easily discharged. Since the temperature of the refrigerant flowing through the cooling pipe 30 is lower than the temperature of the refrigerant in the receiver 5, the gas refrigerant in the receiver 5 can be liquefied to lower the internal pressure, and the refrigerant easily flows into the receiver 5. Become.
  • the cooling pipe 30 and the heating pipe 31 are narrower than the refrigerant circuit pipe, and the cooling pipe 30 and the heating pipe 31 are wound around the receiver 5. Although the refrigerant flows from the refrigerant circuit to the cooling pipe 30 or the heating pipe 31, the amount of circulating refrigerant can be reduced only slightly.
  • the compressor 1, the condenser 2, the throttle unit 3, and the evaporator 4 are provided with a refrigerant circuit that is connected by piping, and the throttle unit 3 adjusts the amount of refrigerant that circulates in the refrigerant circuit and the receiver 5 that stores the refrigerant.
  • a plurality of flow rate adjusting devices 6 that adjust the amount of refrigerant stored in the receiver 5, and the receiver 5 includes a plurality of tanks 40.
  • the tank 40 can be arranged in a small gap, and the degree of freedom of arrangement of the receiver 5 is increased. That is, the plurality of tanks 40 are arranged in the gaps in the outdoor unit 11.
  • the gap created in the outdoor unit 11 can be used effectively, and it is possible to reduce the size of the outdoor unit 11 without installing a space for installing the receiver 5.
  • a plurality of tanks 40 are connected to one connecting pipe 8 connected to the refrigerant pipe, and the tanks 40 are arranged in a shifted manner. Thereby, the refrigerant can be taken in and out in order with respect to each tank 40.
  • the compressor 1, the condenser 2, the throttle unit 3, and the evaporator 4 are provided with a refrigerant circuit that is connected by piping, and the throttle unit 3 adjusts the amount of refrigerant that circulates in the refrigerant circuit and the receiver 5 that stores the refrigerant.
  • the flow rate adjusting device 6 is configured so that the amount of refrigerant circulating in the refrigerant circuit becomes the optimum amount of refrigerant according to the air conditioning operation.
  • a control device 20 for controlling is provided, and the control device 20 determines whether or not the refrigeration cycle is stabilized by using a mathematical expression representing a change in the discharge temperature of the compressor 1, and the flow rate adjusting device after the refrigeration cycle is stabilized. The opening degree of 6 is controlled.
  • a plurality of mathematical formulas using the rotational speed of the compressor 1 as a parameter is prepared, and the control device 20 selects a mathematical formula to be used for determination according to the rotational speed of the compressor 1 during operation.
  • the timing at which the refrigeration cycle is stabilized differs depending on the rotation speed of the compressor 1. Therefore, it is possible to accurately determine that the refrigeration cycle is stable by selecting a mathematical formula corresponding to the rotational speed.
  • this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of the present invention.
  • the flow rate adjusting device 6 a plurality of capillary tubes may be arranged to switch the flow path.
  • you may use the expansion valve from which the opening area of a valve differs as the flow volume adjustment apparatus 6.
  • the diameter and length of the connecting pipe 8 connected to the plurality of receivers 5 may be changed. Refrigerant accumulates in each connecting pipe 8, but the amount of accumulated refrigerant is different. Thus, since the connection pipe 8 is also a part of the receiver 5, even if the volume of each receiver 5 is made the same, the volume of each receiver 5 can be varied. When the gap in which the receiver 5 is installed is away from the piping of the refrigerant circuit, the connecting pipe 8 becomes longer and the volume increases accordingly. Even if the volume of the receiver 5 itself is not changed, the volume of the receiver 5 at a far position is different from the volume of other receivers 5 at a near position.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

La présente invention concerne un climatiseur pourvu d'un circuit de réfrigération formé en raccordant, par le biais de conduites, un compresseur (1), un condenseur (2), une section étrangleur (3), et un évaporateur (4). La section étrangleur (3) est constituée de réservoirs (5) permettant d'accumuler un fluide frigorigène et de dispositifs de réglage du débit (6) permettant de régler la quantité d'un fluide frigorigène destiné à être accumulé dans chacun des réservoirs (5), le réglage étant effectué afin de régler la quantité d'un fluide frigorigène circulant à travers le circuit de réfrigération. Lorsque le dispositif de réglage du débit (6) fonctionne conformément aux conditions de fonctionnement, la quantité d'un fluide frigorigène s'accumulant dans chacun des réservoirs (5) est réglée. La quantité d'un fluide frigorigène circulant à travers le circuit de réfrigération change et devient une quantité appropriée correspondant aux conditions de fonctionnement.
PCT/JP2014/071045 2013-10-31 2014-08-08 Climatiseur WO2015064172A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2013-226643 2013-10-31
JP2013226643A JP6309739B2 (ja) 2013-10-31 2013-10-31 空気調和機

Publications (1)

Publication Number Publication Date
WO2015064172A1 true WO2015064172A1 (fr) 2015-05-07

Family

ID=53003788

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/071045 WO2015064172A1 (fr) 2013-10-31 2014-08-08 Climatiseur

Country Status (2)

Country Link
JP (1) JP6309739B2 (fr)
WO (1) WO2015064172A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017061010A1 (fr) * 2015-10-08 2017-04-13 三菱電機株式会社 Dispositif à cycle réfrigérant
WO2020053613A1 (fr) * 2018-09-12 2020-03-19 Carrier Corporation Réservoir de liquide pour système de chauffage, de climatisation et de réfrigération
CN111164355A (zh) * 2017-10-10 2020-05-15 三菱电机株式会社 空调装置
CN112714849A (zh) * 2018-09-28 2021-04-27 三菱电机株式会社 制冷循环装置
US11002467B2 (en) * 2016-10-25 2021-05-11 Mitsubishi Electric Corporation Refrigeration cycle apparatus
CN113587336A (zh) * 2021-06-25 2021-11-02 宁波奥克斯电气股份有限公司 空调器低温制冷持续运转控制方法、装置及空调器
EP4145067A4 (fr) * 2020-04-27 2023-11-15 Daikin Industries, Ltd. Dispositif de commande de récupération de réfrigérant et système de commande de récupération de réfrigérant
EP4375590A1 (fr) * 2022-11-22 2024-05-29 Carrier Corporation Compensateur de charge pour pompe à chaleur

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3147587B1 (fr) * 2015-07-27 2018-03-21 Mitsubishi Electric Corporation Dispositif de climatisation
CN207556037U (zh) * 2017-09-08 2018-06-29 开利公司 储液器及具有其的热泵系统
JP7257151B2 (ja) * 2019-01-24 2023-04-13 サンデン・リテールシステム株式会社 冷却装置
CN113518886B (zh) 2019-03-06 2022-11-11 三菱电机株式会社 制冷循环装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07324828A (ja) * 1994-05-30 1995-12-12 Mitsubishi Electric Corp 冷媒循環システム
JPH1089780A (ja) * 1996-09-13 1998-04-10 Mitsubishi Electric Corp 冷凍システム装置
JP2002162120A (ja) * 2000-11-20 2002-06-07 Fujitsu General Ltd 空気調和機の冷凍装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0756420B2 (ja) * 1989-03-31 1995-06-14 新明和工業株式会社 超低温冷凍装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07324828A (ja) * 1994-05-30 1995-12-12 Mitsubishi Electric Corp 冷媒循環システム
JPH1089780A (ja) * 1996-09-13 1998-04-10 Mitsubishi Electric Corp 冷凍システム装置
JP2002162120A (ja) * 2000-11-20 2002-06-07 Fujitsu General Ltd 空気調和機の冷凍装置

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2017061010A1 (ja) * 2015-10-08 2018-06-07 三菱電機株式会社 冷凍サイクル装置
WO2017061010A1 (fr) * 2015-10-08 2017-04-13 三菱電機株式会社 Dispositif à cycle réfrigérant
US11002467B2 (en) * 2016-10-25 2021-05-11 Mitsubishi Electric Corporation Refrigeration cycle apparatus
US11435117B2 (en) 2017-10-10 2022-09-06 Mitsubishi Electric Corporation Air-conditioning apparatus
CN111164355A (zh) * 2017-10-10 2020-05-15 三菱电机株式会社 空调装置
EP3696473A4 (fr) * 2017-10-10 2020-11-04 Mitsubishi Electric Corporation Dispositif de climatisation
CN111164355B (zh) * 2017-10-10 2024-01-05 三菱电机株式会社 空调装置
WO2020053613A1 (fr) * 2018-09-12 2020-03-19 Carrier Corporation Réservoir de liquide pour système de chauffage, de climatisation et de réfrigération
CN112313458A (zh) * 2018-09-12 2021-02-02 开利公司 用于加热、空气调节和制冷系统的液体接收器
US11592216B2 (en) 2018-09-12 2023-02-28 Carrier Corporation Liquid receiver for heating, air conditioning and refrigeration system
CN112714849A (zh) * 2018-09-28 2021-04-27 三菱电机株式会社 制冷循环装置
CN112714849B (zh) * 2018-09-28 2022-07-08 三菱电机株式会社 制冷循环装置
EP4145067A4 (fr) * 2020-04-27 2023-11-15 Daikin Industries, Ltd. Dispositif de commande de récupération de réfrigérant et système de commande de récupération de réfrigérant
CN113587336A (zh) * 2021-06-25 2021-11-02 宁波奥克斯电气股份有限公司 空调器低温制冷持续运转控制方法、装置及空调器
EP4375590A1 (fr) * 2022-11-22 2024-05-29 Carrier Corporation Compensateur de charge pour pompe à chaleur

Also Published As

Publication number Publication date
JP2015087065A (ja) 2015-05-07
JP6309739B2 (ja) 2018-04-11

Similar Documents

Publication Publication Date Title
JP6309739B2 (ja) 空気調和機
JP4497234B2 (ja) 空気調和装置
US7954333B2 (en) Air conditioner
EP3059515B1 (fr) Climatiseur
JP5056855B2 (ja) 空気調和装置
US9513041B2 (en) Air conditioner
US9151522B2 (en) Air conditioner and control method thereof
US7997093B2 (en) Air conditioner
US10281184B2 (en) Air conditioner
KR20130018917A (ko) 공기 조화 장치의 운전 제어 장치 및 이를 구비한 공기 조화 장치
WO2009157191A1 (fr) Climatiseur et procédé pour déterminer la quantité d’agent frigorigène dans celui-ci
JP2007315682A (ja) 水熱源ヒートポンプユニットシステムの制御方法
JP5110192B1 (ja) 冷凍装置
JP2014119145A (ja) 空気調和機
AU2013250512B2 (en) Air conditioner
JP6355325B2 (ja) 冷蔵庫、及び、冷蔵庫の制御方法
JP5593905B2 (ja) 冷凍装置
JP5505477B2 (ja) 空気調和装置および空気調和装置の冷媒量判定方法
JP2017009269A (ja) 空調システム
JP2010007996A (ja) 空気調和装置の試運転方法および空気調和装置
US9546806B2 (en) Air conditioner
JP5245575B2 (ja) 空気調和装置の冷媒量判定方法および空気調和装置
JP6092606B2 (ja) 空気調和機
JP2016161235A (ja) 冷凍サイクル装置
AU2013250426B9 (en) Air conditioner

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14857569

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14857569

Country of ref document: EP

Kind code of ref document: A1