WO2023100233A1 - Air conditioning device - Google Patents

Air conditioning device Download PDF

Info

Publication number
WO2023100233A1
WO2023100233A1 PCT/JP2021/043824 JP2021043824W WO2023100233A1 WO 2023100233 A1 WO2023100233 A1 WO 2023100233A1 JP 2021043824 W JP2021043824 W JP 2021043824W WO 2023100233 A1 WO2023100233 A1 WO 2023100233A1
Authority
WO
WIPO (PCT)
Prior art keywords
refrigerant
heat exchanger
compressor
connection point
circuit
Prior art date
Application number
PCT/JP2021/043824
Other languages
French (fr)
Japanese (ja)
Inventor
祐樹 永田
幸志 東
周平 水谷
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2023564291A priority Critical patent/JPWO2023100233A1/ja
Priority to PCT/JP2021/043824 priority patent/WO2023100233A1/en
Publication of WO2023100233A1 publication Critical patent/WO2023100233A1/en

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
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle

Definitions

  • the present disclosure relates to an air conditioner that includes a refrigerant circuit.
  • an air conditioner that includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion section, and an indoor heat exchanger are sequentially connected by pipes and a refrigerant flows.
  • a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion section, and an indoor heat exchanger are sequentially connected by pipes and a refrigerant flows.
  • liquid backflow that can occur in the air conditioner will be described.
  • the refrigerant sucked into the compressor returns in a liquid state without completely evaporating, the liquid refrigerant expands again inside the compressor, damaging the compressor and reducing the air conditioning efficiency of the air conditioner. do.
  • the air conditioner continues to be used in a state of liquid backflow, the amount of gaseous refrigerant sucked into the compressor decreases, and the gaseous refrigerant cannot be compressed much.
  • Patent Document 1 discloses a configuration for preventing liquid backflow, in which hot gas discharged from a compressor is flowed into the compressor through an ejector at regular intervals, and liquid A refrigeration system is disclosed that evaporates a state refrigerant.
  • the present disclosure has been made to solve the above problems, and provides an air conditioner that suppresses liquid backflow even if an abnormality occurs in the expansion part.
  • the air conditioner according to the present disclosure includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion section, and an indoor heat exchanger are sequentially connected by refrigerant pipes, in which the refrigerant circulates, and the outdoor heat exchanger and the expansion section in the refrigerant circuit.
  • a branch circuit that branches from the first connection point on the outdoor heat exchanger side between and merges with the second connection point that is on the expansion section side between the outdoor heat exchanger and the expansion section, and a compression in the refrigerant circuit a refrigerant heat exchanger that exchanges heat between refrigerant flowing through a first flow path between the machine and the indoor heat exchanger and refrigerant flowing through a second flow path of the branch circuit.
  • the refrigerant heat exchanger exchanges heat between the refrigerant flowing through the first flow path and the refrigerant flowing through the second flow path. Therefore, in the cooling operation, the refrigerant flowing through the first flow path is warmed by the refrigerant flowing through the second flow path. As a result, even if liquid refrigerant exists in the first channel, the liquid refrigerant becomes gaseous refrigerant. Therefore, liquid backflow can be suppressed even if an abnormality occurs in the expansion portion.
  • FIG. 1 is a circuit diagram showing an air conditioner according to Embodiment 1.
  • FIG. 1 is a schematic diagram showing an accumulator according to Embodiment 1;
  • FIG. 10 is a circuit diagram showing an air conditioner according to Embodiment 2;
  • 9 is a flow chart showing the operation of the control device according to Embodiment 2;
  • FIG. 1 is a circuit diagram showing an air conditioner 100 according to Embodiment 1.
  • the air conditioner 100 is a device that adjusts air in an air-conditioned room, and includes an outdoor unit 20, an indoor unit 30, and a control device 40, as shown in FIG.
  • the outdoor unit 20 is provided with, for example, a compressor 1, a channel switching device 2, an outdoor heat exchanger 3, an outdoor fan 11, an accumulator 7, and a refrigerant heat exchanger .
  • the indoor unit 30 is provided with an expansion section 5, an indoor heat exchanger 6, and an indoor fan 12, for example.
  • a refrigerant circuit 100a is configured by connecting the compressor 1, the flow path switching device 2, the outdoor heat exchanger 3, the expansion section 5, and the indoor heat exchanger 6 by refrigerant pipes 4.
  • the compressor 1 sucks a low-temperature, low-pressure refrigerant, compresses the sucked refrigerant, converts it into a high-temperature, high-pressure refrigerant, and discharges it.
  • the compressor 1 is, for example, a capacity-controllable inverter compressor.
  • a high pressure sensor 8 is provided on the discharge side of the compressor 1 .
  • the high pressure sensor 8 detects the high pressure discharged from the compressor 1 .
  • a low pressure sensor 9 is provided on the suction side of the compressor 1 .
  • the low pressure sensor 9 detects the low pressure sucked into the compressor 1 .
  • the flow path switching device 2 switches the direction in which the refrigerant flows in the refrigerant circuit 100a, and is, for example, a four-way valve.
  • the solid line indicates the flow path of the refrigerant in the flow switching device 2 during cooling operation
  • the dashed line indicates the flow path of the refrigerant in the flow switching device 2 during heating.
  • the outdoor heat exchanger 3 exchanges heat, for example, between outdoor air and refrigerant.
  • the outdoor heat exchanger 3 is, for example, a fin-and-tube heat exchanger having heat transfer tubes through which a refrigerant flows.
  • the outdoor heat exchanger 3 acts as a condenser during cooling operation and acts as an evaporator during heating operation.
  • the outdoor blower 11 is a device that sends outdoor air to the outdoor heat exchanger 3 .
  • FIG. 2 is a schematic diagram showing the accumulator 7 according to Embodiment 1.
  • FIG. The accumulator 7 is connected between the flow switching device 2 and the suction side of the compressor 1 .
  • An accumulator 7 is provided to store excess refrigerant resulting from changes in operating modes and operating conditions.
  • the accumulator 7 has an inflow pipe 21 into which refrigerant flows and an outflow pipe 22 into which gas refrigerant flows out toward the compressor 1 .
  • the inflow pipe 21 and the outflow pipe 22 are connected to the refrigerant pipe 4 to form a refrigerant circuit 100a.
  • the accumulator 7 separates the refrigerant flowing from the inflow pipe 21 into gas refrigerant and liquid refrigerant.
  • a liquid refrigerant is stored in the bottom of the accumulator 7 .
  • a gaseous refrigerant is discharged from an outflow pipe 22 of the accumulator 7 .
  • Refrigerating machine oil circulating in the refrigerant circuit 100a flows into the accumulator 7 together with the refrigerant, and is stored at the bottom. Refrigerant oil stored in the accumulator 7 is returned to the compressor 1 through a small hole 23 formed in the accumulator 7 .
  • the volume of the accumulator 7 is a volume that can accommodate an assumed maximum volume of fluid, which is the volume of fluid that is the sum of the surplus refrigerant generated due to changes in the operation mode and operating conditions and the refrigerating machine oil taken out from the compressor 1. I wish I had.
  • the inlet of the outflow pipe 22 through which the refrigerant is sucked is attached so as to be higher than the liquid level of the fluid stored in the accumulator 7 .
  • the fluid stored in the accumulator 7 is prevented from overflowing the accumulator 7 and flowing into the compressor 1 through the inlet of the outflow pipe 22 .
  • the branch circuit 100b branches from a first connection point 51 on the outdoor heat exchanger 3 side between the outdoor heat exchanger 3 and the expansion section 5 in the refrigerant circuit 100a, and connects the outdoor heat exchanger 3 and the expansion section 5. It merges with the second connection point 52 on the inflatable portion 5 side.
  • a check valve 13 is provided in the branch circuit 100b.
  • the check valve 13 is provided in the branch circuit 100b, allows the refrigerant to flow from the first connection point 51 side to the second connection point 52 side in the branch circuit 100b, and allows the refrigerant to flow from the second connection point 52 side in the branch circuit 100b. It suppresses the refrigerant from flowing to the first connection point 51 side.
  • the refrigerant heat exchanger 14 is provided between the channel switching device 2 and the indoor heat exchanger 6 .
  • the refrigerant heat exchanger 14 is provided between the refrigerant flowing through the first flow path 14a between the compressor 1 and the indoor heat exchanger 6 in the refrigerant circuit 100a and the refrigerant flowing through the second flow path 14b of the branch circuit 100b. It exchanges heat.
  • the expansion section 5 is a pressure reducing valve or an expansion valve that reduces the pressure of the refrigerant to expand it.
  • the expansion part 5 is, for example, an electronic expansion valve whose opening is adjusted.
  • the indoor heat exchanger 6 exchanges heat, for example, between indoor air and refrigerant.
  • the indoor heat exchanger 6 is, for example, a fin-and-tube heat exchanger having heat transfer tubes through which refrigerant flows.
  • the indoor heat exchanger 6 acts as an evaporator during cooling operation, and acts as a condenser during heating operation.
  • the degree of opening of the expansion section 5 is adjusted so that the temperature difference between the refrigerant flowing through the inlet side and the refrigerant flowing through the outlet side of the indoor heat exchanger 6 becomes a temperature difference corresponding to the air conditioning load.
  • the indoor fan 12 is a device that sends indoor air to the indoor heat exchanger 6 .
  • An indoor unit pipe temperature sensor 10 is provided near the indoor heat exchanger 6 . The indoor unit pipe temperature sensor 10 detects the temperature of the refrigerant flowing through the indoor heat exchanger 6 .
  • the control device 40 is composed of a CPU (Central Processing Unit, also referred to as a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a processor) that executes programs stored in dedicated hardware or a storage device. . If the control device 40 is dedicated hardware, the control device 40 may be, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. is applicable. Each functional unit implemented by the control device 40 may be implemented by separate hardware, or each functional unit may be implemented by one piece of hardware.
  • a CPU Central Processing Unit
  • a processing unit also referred to as a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a processor
  • the control device 40 may be, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA
  • each function executed by the control device 40 is implemented by software, firmware, or a combination of software and firmware.
  • Software and firmware are written as programs and stored in storage devices.
  • the CPU implements each function by reading and executing a program stored in the storage device.
  • a part of the functions of the control device 40 may be realized by dedicated hardware, and a part thereof may be realized by software or firmware.
  • the storage device may be configured as a hard disk or as a volatile storage device such as a random access memory (RAM) capable of temporarily storing data.
  • the storage device may also be configured as a non-volatile storage device such as a flash memory capable of long-term storage of data.
  • the control device 40 may be provided in the indoor unit 30, and the control device 40 may be an external unit. may be provided in
  • cooling operation Next, operation modes of the air conditioner 100 will be described.
  • the cooling operation the refrigerant sucked into the compressor 1 is compressed by the compressor 1 and discharged in a high-temperature and high-pressure gas state.
  • the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 passes through the flow switching device 2 and flows into the outdoor heat exchanger 3 acting as a condenser. It is heat-exchanged with the outdoor air sent by 11 and condenses and liquefies.
  • the condensed liquid state refrigerant branches at the first connection point 51 .
  • the refrigerant flowing into the branch circuit 100b at the first connection point 51 passes through the check valve 13, reaches the refrigerant heat exchanger 14, and joins with the refrigerant flowing into the refrigerant circuit 100a at the second connection point 52.
  • Refrigerant that has not flowed into the branch circuit 100b at the first connection point 51 passes through the second connection point 52 and flows into the expansion section 5, where it is expanded and decompressed in the expansion section 5 to produce a low-temperature, low-pressure gas-liquid two-phase refrigerant. state refrigerant.
  • the gas-liquid two-phase refrigerant flows into the indoor heat exchanger 6 acting as an evaporator, where it exchanges heat with the indoor air sent by the indoor blower 12 and evaporates into gas. do.
  • the indoor air is cooled, and cooling is performed in the room.
  • the evaporated low-temperature, low-pressure gaseous refrigerant flows into the refrigerant heat exchanger 14, where it is heat-exchanged with the refrigerant flowing in the branch circuit 100b, and further evaporated and gasified.
  • the sufficiently gasified refrigerant passes through the flow switching device 2 and the accumulator 7 and is sucked into the compressor 1 .
  • the heating operation In the heating operation, the refrigerant sucked into the compressor 1 is compressed by the compressor 1 and discharged in a high-temperature and high-pressure gas state.
  • the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 passes through the flow switching device 2 and the refrigerant heat exchanger 14, flows into the indoor heat exchanger 6 acting as a condenser, and undergoes indoor heat exchange.
  • heat is exchanged with indoor air sent by the indoor blower 12 to condense and liquefy. At this time, the indoor air is warmed, and heating is performed in the room.
  • the condensed liquid refrigerant flows into the expansion section 5, where it is expanded and decompressed to become a low-temperature, low-pressure gas-liquid two-phase refrigerant.
  • the gas-liquid two-phase refrigerant reaches the second connection point 52 .
  • the check valve 13 is provided in the branch circuit 100b, the refrigerant reaching the second connection point 52 does not flow into the branch circuit 100b.
  • the refrigerant that has passed through the second connection point 52 passes through the first connection point 51 and flows into the outdoor heat exchanger 3 acting as an evaporator.
  • the outdoor heat exchanger 3 the outdoor air sent by the outdoor fan 11 is evaporates and gasifies.
  • the vaporized low-temperature, low-pressure gaseous refrigerant passes through the flow switching device 2 and the accumulator 7 and is sucked into the compressor 1 .
  • the refrigerant cannot absorb heat from the indoor air, and the low-pressure two-phase state does not become a gas state, and the two-phase state It flows out from the indoor heat exchanger 6 in this state.
  • the low-pressure two-phase refrigerant flows through the first passage 14a of the refrigerant heat exchanger 14, and in the process heats up with the high-temperature liquid refrigerant flowing through the second passage 14b of the branch circuit 100b. exchange takes place.
  • the low-pressure two-phase refrigerant evaporates into gaseous refrigerant, flows into the accumulator 7 via the flow path switching device 2 , and is then sucked into the compressor 1 .
  • the liquid state refrigerant unintentionally leaks from the expansion section 5 due to the clogging of the expansion section 5, the liquid state refrigerant at a high temperature flows to the refrigerant heat exchanger 14 and becomes a gaseous state refrigerant. 1 is inhaled.
  • the refrigerant heat exchanger 14 exchanges heat between the refrigerant flowing through the first flow path 14a and the refrigerant flowing through the second flow path 14b. Therefore, in the cooling operation, the refrigerant flowing through the first flow path 14a is warmed by the refrigerant flowing through the second flow path 14b. As a result, even if liquid refrigerant exists in the first flow path 14a, the liquid refrigerant becomes gaseous refrigerant. Therefore, even if an abnormality occurs in the inflatable portion 5, liquid backflow can be suppressed.
  • FIG. 3 is a circuit diagram showing an air conditioner 200 according to Embodiment 2. As shown in FIG. Embodiment 2 differs from Embodiment 1 in that the refrigerant heat exchanger 14 and check valve 13 of Embodiment 1 are not provided, and a refrigerant flow rate adjustment valve 13a is provided.
  • the same reference numerals are given to the parts that are common to the first embodiment, and the description thereof is omitted.
  • the refrigerant flow control valve 13a is connected to the branch circuit 100b.
  • the refrigerant flow control valve 13a adjusts the flow rate of the refrigerant flowing through the branch circuit 100b.
  • the air conditioner 200 further includes a temperature detector 15.
  • the temperature detection unit 15 is provided on the suction side of the compressor 1 and detects the temperature of the refrigerant flowing on the suction side of the compressor 1 .
  • the control device 40 increases the degree of opening of the refrigerant flow control valve 13a.
  • the temperature of the liquid refrigerant is higher than the temperature of the gaseous refrigerant.
  • the threshold temperature when the temperature of the refrigerant flowing to the suction side of the compressor 1 is equal to or higher than the threshold temperature, it is determined that a large amount of liquid refrigerant may back up.
  • the flow rate of the refrigerant flowing through the branch circuit 100b and the refrigerant circuit 100a is adjusted by increasing the opening degree of the refrigerant flow rate control valve 13a. This makes it difficult for the refrigerant in a liquid state to be sucked into the compressor 1, and liquid backflow in the compressor 1 can be prevented without using a special device such as an ejector.
  • FIG. 4 is a flow chart showing the operation of the control device 40 according to the second embodiment. Next, operation of the control device 40 will be described.
  • the control device 40 determines whether or not the temperature detected by the temperature detector 15 is equal to or higher than the threshold temperature (step ST01). If the temperature is less than the threshold temperature (No in step ST01), the control device 40 determines that the possibility of liquid backflow is low, and sets the opening degree of the refrigerant flow control valve 13a to zero (step ST02).
  • step ST01 determines that there is a possibility of liquid backflow, and increases the opening degree of the refrigerant flow control valve 13a (step ST03). This makes it difficult for the refrigerant in the liquid state to be sucked into the compressor 1 , and liquid backflow in the compressor 1 can be prevented.
  • the control device 40 determines whether the temperature detected by the temperature detection section 15 is less than the threshold temperature (step ST04). If the temperature is equal to or higher than the threshold temperature (No in step ST04), the control device 40 determines that there is still a possibility of liquid backflow, and returns to step ST04. On the other hand, if the temperature is less than the threshold temperature (Yes in step ST04), the control device 40 determines that the possibility of liquid backflow has decreased, and sets the opening degree of the refrigerant flow control valve 13a to zero (step ST05). .
  • the control device 40 increases the opening degree of the refrigerant flow rate adjustment valve 13a when the temperature detected by the temperature detection unit 15 is equal to or higher than a predetermined threshold temperature. This makes it difficult for the refrigerant in the liquid state to be sucked into the compressor 1 , and liquid backflow in the compressor 1 can be prevented.
  • the second embodiment exemplifies the case where the refrigerant heat exchanger 14 and the check valve 13 are not provided, the refrigerant heat exchanger 14 and the check valve 13 may be provided.
  • the control of the refrigerant flow control valve 13a and the control of the refrigerant heat exchanger 14 can be used together according to the possibility of liquid backflow.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Abstract

This air conditioning device comprises: a refrigerant circuit that is configured by a compressor, an outdoor heat exchanger, an expansion unit, and an indoor heat exchanger being sequentially connected by refrigerant piping and circulates a refrigerant therethrough; a branch circuit that branches from a first connection point on the outdoor heat exchanger side between the outdoor heat exchanger and the expansion unit in the refrigerant circuit and joins a second connection point on the expansion unit side between the outdoor heat exchanger and the expansion unit; and a refrigerant heat exchanger that exchanges heat between the refrigerant flowing in a first flow path between the compressor and the indoor heat exchanger in the refrigerant circuit and the refrigerant flowing in a second flow path of the branch circuit.

Description

空気調和装置air conditioner
　本開示は、冷媒回路を備える空気調和装置に関する。 The present disclosure relates to an air conditioner that includes a refrigerant circuit.
　従来、圧縮機、室外熱交換器、膨張部及び室内熱交換器が配管により順次接続され、冷媒が流れる冷媒回路を備える空気調和装置が知られている。ここで、空気調和装置において生じ得る液バックについて説明する。圧縮機に吸入される冷媒が、蒸発し切れずに液状態で戻ってくると、液状態の冷媒が圧縮機内で再膨張し、圧縮機にダメージを与えると共に、空気調和装置の空調効率が低下する。液バックしている状態で空気調和装置の使用が継続されると、圧縮機が吸い込むガス状態の冷媒の量が少なくなり、ガス状態の冷媒をあまり圧縮することができなくなる。 Conventionally, an air conditioner is known that includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion section, and an indoor heat exchanger are sequentially connected by pipes and a refrigerant flows. Here, liquid backflow that can occur in the air conditioner will be described. When the refrigerant sucked into the compressor returns in a liquid state without completely evaporating, the liquid refrigerant expands again inside the compressor, damaging the compressor and reducing the air conditioning efficiency of the air conditioner. do. If the air conditioner continues to be used in a state of liquid backflow, the amount of gaseous refrigerant sucked into the compressor decreases, and the gaseous refrigerant cannot be compressed much.
　この課題を解決することを目的として、特許文献１には、液バックを防止する構成として、一定時間毎に、圧縮機から吐出されたホットガスを、エジェクタを経て、圧縮機に流入させ、液状態の冷媒を蒸発させる冷凍装置が開示されている。 For the purpose of solving this problem, Patent Document 1 discloses a configuration for preventing liquid backflow, in which hot gas discharged from a compressor is flowed into the compressor through an ejector at regular intervals, and liquid A refrigeration system is disclosed that evaporates a state refrigerant.
特開２００５－２４１６３号公報JP 2005-24163 A
　しかしながら、特許文献１に開示された冷凍装置において、冷房運転中に、膨張部に異物が混入したり、異物が噛み込んだりすると、膨張部が全閉状態にならない。膨張部が全閉状態にならないと、膨張部から冷媒が漏れ、そのままアキュムレータに流れ込む。膨張部から漏れた冷媒によりアキュムレータの液面から冷媒があふれると、液状態の冷媒が圧縮機に流入して液バックが生じるおそれがある。 However, in the refrigerating apparatus disclosed in Patent Document 1, if foreign matter enters or is caught in the expansion portion during cooling operation, the expansion portion will not be fully closed. If the expansion section is not fully closed, the refrigerant leaks from the expansion section and flows directly into the accumulator. If the refrigerant leaking from the expansion section overflows the liquid surface of the accumulator, liquid refrigerant may flow into the compressor and cause liquid backflow.
　本開示は、上記のような課題を解決するためになされたもので、膨張部に異常が発生しても、液バックを抑制する空気調和装置を提供するものである。 The present disclosure has been made to solve the above problems, and provides an air conditioner that suppresses liquid backflow even if an abnormality occurs in the expansion part.
　本開示に係る空気調和装置は、圧縮機、室外熱交換器、膨張部及び室内熱交換器が冷媒配管により順次接続され、冷媒が循環する冷媒回路と、冷媒回路における室外熱交換器と膨張部との間の室外熱交換器側である第１接続点から分岐し、室外熱交換器と膨張部との間の膨張部側である第２接続点に合流する分岐回路と、冷媒回路における圧縮機と室内熱交換器との間の第１流路に流れる冷媒と、分岐回路の第２流路に流れる冷媒との間で熱交換する冷媒熱交換器と、を備える。 The air conditioner according to the present disclosure includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion section, and an indoor heat exchanger are sequentially connected by refrigerant pipes, in which the refrigerant circulates, and the outdoor heat exchanger and the expansion section in the refrigerant circuit. A branch circuit that branches from the first connection point on the outdoor heat exchanger side between and merges with the second connection point that is on the expansion section side between the outdoor heat exchanger and the expansion section, and a compression in the refrigerant circuit a refrigerant heat exchanger that exchanges heat between refrigerant flowing through a first flow path between the machine and the indoor heat exchanger and refrigerant flowing through a second flow path of the branch circuit.
　本開示によれば、冷媒熱交換器が、第１流路に流れる冷媒と第２流路に流れる冷媒との間で熱交換する。このため、冷房運転の場合、第１流路に流れる冷媒が第２流路に流れる冷媒によって温められる。これにより、第１流路に液状態の冷媒が存在していても、液状態の冷媒がガス状態の冷媒になる。従って、膨張部に異常が発生しても、液バックを抑制することができる。 According to the present disclosure, the refrigerant heat exchanger exchanges heat between the refrigerant flowing through the first flow path and the refrigerant flowing through the second flow path. Therefore, in the cooling operation, the refrigerant flowing through the first flow path is warmed by the refrigerant flowing through the second flow path. As a result, even if liquid refrigerant exists in the first channel, the liquid refrigerant becomes gaseous refrigerant. Therefore, liquid backflow can be suppressed even if an abnormality occurs in the expansion portion.
実施の形態１に係る空気調和装置を示す回路図である。1 is a circuit diagram showing an air conditioner according to Embodiment 1. FIG. 実施の形態１に係るアキュムレータを示す模式図である。1 is a schematic diagram showing an accumulator according to Embodiment 1; FIG. 実施の形態２に係る空気調和装置を示す回路図である。FIG. 10 is a circuit diagram showing an air conditioner according to Embodiment 2; 実施の形態２に係る制御装置の動作を示すフローチャートである。9 is a flow chart showing the operation of the control device according to Embodiment 2;
　以下、本開示の空気調和装置の実施の形態について、図面を参照しながら説明する。なお、本開示は、以下に説明する実施の形態によって限定されるものではない。また、図１を含め、以下の図面では各構成部材の大きさの関係が実際のものとは異なる場合がある。また、以下の説明において、本開示の理解を容易にするために方向を表す用語を適宜用いるが、これは本開示を説明するためのものであって、これらの用語は本開示を限定するものではない。方向を表す用語としては、例えば、「上」、「下」、「右」、「左」、「前」又は「後」等が挙げられる。 Hereinafter, embodiments of the air conditioner of the present disclosure will be described with reference to the drawings. It should be noted that the present disclosure is not limited by the embodiments described below. In addition, in the following drawings, including FIG. 1, the size relationship of each constituent member may differ from the actual one. In addition, in the following description, directional terms are used as appropriate to facilitate understanding of the present disclosure, but this is for the purpose of describing the present disclosure, and these terms are intended to limit the present disclosure. isn't it. Directional terms include, for example, "up", "down", "right", "left", "front" or "back".
実施の形態１．
　図１は、実施の形態１に係る空気調和装置１００を示す回路図である。空気調和装置１００は、被空調室の空気を調整する装置であり、図１に示すように、室外機２０と、室内機３０と、制御装置４０とを備えている。室外機２０には、例えば圧縮機１、流路切替装置２、室外熱交換器３、室外送風機１１、アキュムレータ７及び冷媒熱交換器１４が設けられている。室内機３０には、例えば膨張部５、室内熱交換器６及び室内送風機１２が設けられている。 Embodiment 1.
FIG. 1 is a circuit diagram showing an air conditioner 100 according to Embodiment 1. FIG. The air conditioner 100 is a device that adjusts air in an air-conditioned room, and includes an outdoor unit 20, an indoor unit 30, and a control device 40, as shown in FIG. The outdoor unit 20 is provided with, for example, a compressor 1, a channel switching device 2, an outdoor heat exchanger 3, an outdoor fan 11, an accumulator 7, and a refrigerant heat exchanger . The indoor unit 30 is provided with an expansion section 5, an indoor heat exchanger 6, and an indoor fan 12, for example.
　圧縮機１、流路切替装置２、室外熱交換器３、膨張部５及び室内熱交換器６が冷媒配管４により接続されて冷媒回路１００ａが構成されている。圧縮機１は、低温且つ低圧の状態の冷媒を吸入し、吸入した冷媒を圧縮して高温且つ高圧の状態の冷媒にして吐出するものである。圧縮機１は、例えば容量制御可能なインバータ圧縮機である。圧縮機１の吐出側には、高圧圧力センサ８が設けられている。高圧圧力センサ８は、圧縮機１から吐出された高圧の圧力を検出するものである。圧縮機１の吸入側には、低圧圧力センサ９が設けられている。低圧圧力センサ９は、圧縮機１に吸入される低圧の圧力を検出するものである。 A refrigerant circuit 100a is configured by connecting the compressor 1, the flow path switching device 2, the outdoor heat exchanger 3, the expansion section 5, and the indoor heat exchanger 6 by refrigerant pipes 4. The compressor 1 sucks a low-temperature, low-pressure refrigerant, compresses the sucked refrigerant, converts it into a high-temperature, high-pressure refrigerant, and discharges it. The compressor 1 is, for example, a capacity-controllable inverter compressor. A high pressure sensor 8 is provided on the discharge side of the compressor 1 . The high pressure sensor 8 detects the high pressure discharged from the compressor 1 . A low pressure sensor 9 is provided on the suction side of the compressor 1 . The low pressure sensor 9 detects the low pressure sucked into the compressor 1 .
　流路切替装置２は、冷媒回路１００ａにおいて冷媒が流れる方向を切り替えるものであり、例えば四方弁である。図１において、実線により冷房運転時の流路切替装置２における冷媒の流路を示し、破線により暖房時の流路切替装置２における冷媒の流路が示されている。室外熱交換器３は、例えば室外空気と冷媒との間で熱交換するものである。室外熱交換器３は、例えば、冷媒が流れる伝熱管を有するフィンアンドチューブ型熱交換器である。室外熱交換器３は、冷房運転時には凝縮器として作用し、暖房運転時には蒸発器として作用する。室外送風機１１は、室外熱交換器３に室外空気を送る機器である。 The flow path switching device 2 switches the direction in which the refrigerant flows in the refrigerant circuit 100a, and is, for example, a four-way valve. In FIG. 1 , the solid line indicates the flow path of the refrigerant in the flow switching device 2 during cooling operation, and the dashed line indicates the flow path of the refrigerant in the flow switching device 2 during heating. The outdoor heat exchanger 3 exchanges heat, for example, between outdoor air and refrigerant. The outdoor heat exchanger 3 is, for example, a fin-and-tube heat exchanger having heat transfer tubes through which a refrigerant flows. The outdoor heat exchanger 3 acts as a condenser during cooling operation and acts as an evaporator during heating operation. The outdoor blower 11 is a device that sends outdoor air to the outdoor heat exchanger 3 .
　図２は、実施の形態１に係るアキュムレータ７を示す模式図である。アキュムレータ７は、流路切替装置２と圧縮機１の吸入側との間に接続されている。アキュムレータ７は、運転モード及び動作条件の変化に起因して生じる余剰な冷媒を貯留するために設けられている。図２に示すように、アキュムレータ７は、冷媒が流入する流入管２１と、ガス冷媒が圧縮機１に向かって流出する流出管２２とを有する。流入管２１と流出管２２とは、冷媒配管４に接続されており、冷媒回路１００ａが構成されている。 FIG. 2 is a schematic diagram showing the accumulator 7 according to Embodiment 1. FIG. The accumulator 7 is connected between the flow switching device 2 and the suction side of the compressor 1 . An accumulator 7 is provided to store excess refrigerant resulting from changes in operating modes and operating conditions. As shown in FIG. 2 , the accumulator 7 has an inflow pipe 21 into which refrigerant flows and an outflow pipe 22 into which gas refrigerant flows out toward the compressor 1 . The inflow pipe 21 and the outflow pipe 22 are connected to the refrigerant pipe 4 to form a refrigerant circuit 100a.
　アキュムレータ７は、流入管２１から流入した冷媒をガス冷媒と液冷媒とに分離させる。アキュムレータ７の底部には、液状態の冷媒が貯留される。アキュムレータ７の流出管２２からは、ガス状態の冷媒が排出される。アキュムレータ７には、冷媒と共に、冷媒回路１００ａを循環する冷凍機油が流入し、底部に貯留される。アキュムレータ７に貯留された冷凍機油は、アキュムレータ７に形成された小孔２３を介し、圧縮機１に戻される。 The accumulator 7 separates the refrigerant flowing from the inflow pipe 21 into gas refrigerant and liquid refrigerant. A liquid refrigerant is stored in the bottom of the accumulator 7 . A gaseous refrigerant is discharged from an outflow pipe 22 of the accumulator 7 . Refrigerating machine oil circulating in the refrigerant circuit 100a flows into the accumulator 7 together with the refrigerant, and is stored at the bottom. Refrigerant oil stored in the accumulator 7 is returned to the compressor 1 through a small hole 23 formed in the accumulator 7 .
　アキュムレータ７の容積は、運転モード及び動作条件の変化に起因して生じる余剰な冷媒と、圧縮機１から持ち出される冷凍機油とを合算した流体の体積である想定最大体積の流体が収容できる容積であればよい。流出管２２の冷媒が吸入される入口は、アキュムレータ７に貯留される流体の液面の高さよりも高い位置になるように取り付けられている。アキュムレータ７に貯留された流体は、アキュムレータ７から溢れだし、流出管２２の入口から圧縮機１に流入することが防止されている。 The volume of the accumulator 7 is a volume that can accommodate an assumed maximum volume of fluid, which is the volume of fluid that is the sum of the surplus refrigerant generated due to changes in the operation mode and operating conditions and the refrigerating machine oil taken out from the compressor 1. I wish I had. The inlet of the outflow pipe 22 through which the refrigerant is sucked is attached so as to be higher than the liquid level of the fluid stored in the accumulator 7 . The fluid stored in the accumulator 7 is prevented from overflowing the accumulator 7 and flowing into the compressor 1 through the inlet of the outflow pipe 22 .
　ここで、冷媒回路１００ａから分岐する分岐回路１００ｂについて説明する。分岐回路１００ｂは、冷媒回路１００ａにおける室外熱交換器３と膨張部５との間の室外熱交換器３側である第１接続点５１から分岐し、室外熱交換器３と膨張部５との間の膨張部５側である第２接続点５２に合流するものである。分岐回路１００ｂには、逆止弁１３が設けられている。 Here, the branch circuit 100b branched from the refrigerant circuit 100a will be described. The branch circuit 100b branches from a first connection point 51 on the outdoor heat exchanger 3 side between the outdoor heat exchanger 3 and the expansion section 5 in the refrigerant circuit 100a, and connects the outdoor heat exchanger 3 and the expansion section 5. It merges with the second connection point 52 on the inflatable portion 5 side. A check valve 13 is provided in the branch circuit 100b.
　逆止弁１３は、分岐回路１００ｂに設けられ、分岐回路１００ｂにおいて第１接続点５１側から第２接続点５２側に冷媒が流れることを許容し、分岐回路１００ｂにおいて第２接続点５２側から第１接続点５１側に冷媒が流れることを抑制するものである。 The check valve 13 is provided in the branch circuit 100b, allows the refrigerant to flow from the first connection point 51 side to the second connection point 52 side in the branch circuit 100b, and allows the refrigerant to flow from the second connection point 52 side in the branch circuit 100b. It suppresses the refrigerant from flowing to the first connection point 51 side.
　冷媒熱交換器１４は、流路切替装置２と室内熱交換器６との間に設けられている。冷媒熱交換器１４は、冷媒回路１００ａにおける圧縮機１と室内熱交換器６との間の第１流路１４ａに流れる冷媒と、分岐回路１００ｂの第２流路１４ｂに流れる冷媒との間で熱交換するものである。 The refrigerant heat exchanger 14 is provided between the channel switching device 2 and the indoor heat exchanger 6 . The refrigerant heat exchanger 14 is provided between the refrigerant flowing through the first flow path 14a between the compressor 1 and the indoor heat exchanger 6 in the refrigerant circuit 100a and the refrigerant flowing through the second flow path 14b of the branch circuit 100b. It exchanges heat.
　膨張部５は、冷媒を減圧して膨張する減圧弁又は膨張弁である。膨張部５は、例えば開度が調整される電子式膨張弁である。室内熱交換器６は、例えば室内空気と冷媒との間で熱交換するものである。室内熱交換器６は、例えば、冷媒が流れる伝熱管を有するフィンアンドチューブ型熱交換器である。室内熱交換器６は、冷房運転時には蒸発器として作用し、暖房運転時には凝縮器として作用する。室内熱交換器６の入口側を流れる冷媒と出口側を流れる冷媒との温度差が、空調負荷に応じた温度差となるように、膨張部５の開度が調整されている。室内送風機１２は、室内熱交換器６に室内空気を送る機器である。室内熱交換器６の近傍には、室内機配管温度センサ１０が設けられている。室内機配管温度センサ１０は、室内熱交換器６に流れる冷媒の温度を検出するものである。 The expansion section 5 is a pressure reducing valve or an expansion valve that reduces the pressure of the refrigerant to expand it. The expansion part 5 is, for example, an electronic expansion valve whose opening is adjusted. The indoor heat exchanger 6 exchanges heat, for example, between indoor air and refrigerant. The indoor heat exchanger 6 is, for example, a fin-and-tube heat exchanger having heat transfer tubes through which refrigerant flows. The indoor heat exchanger 6 acts as an evaporator during cooling operation, and acts as a condenser during heating operation. The degree of opening of the expansion section 5 is adjusted so that the temperature difference between the refrigerant flowing through the inlet side and the refrigerant flowing through the outlet side of the indoor heat exchanger 6 becomes a temperature difference corresponding to the air conditioning load. The indoor fan 12 is a device that sends indoor air to the indoor heat exchanger 6 . An indoor unit pipe temperature sensor 10 is provided near the indoor heat exchanger 6 . The indoor unit pipe temperature sensor 10 detects the temperature of the refrigerant flowing through the indoor heat exchanger 6 .
　制御装置４０は、専用のハードウェア又は記憶装置に格納されるプログラムを実行するＣＰＵ（Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ、中央処理装置、処理装置、演算装置、マイクロプロセッサ、マイクロコンピュータ又はプロセッサともいう）で構成される。制御装置４０が専用のハードウェアである場合、制御装置４０は、例えば、単一回路、複合回路、ＡＳＩＣ（Ａｐｐｌｉｃａｔｉｏｎ　Ｓｐｅｃｉｆｉｃ　Ｉｎｔｅｇｒａｔｅｄ　Ｃｉｒｃｕｉｔ）、ＦＰＧＡ（Ｆｉｅｌｄ－Ｐｒｏｇｒａｍｍａｂｌｅ　Ｇａｔｅ　Ａｒｒａｙ）、又は、これらを組み合わせたものが該当する。制御装置４０が実現する各機能部のそれぞれを、個別のハードウェアで実現してもよいし、各機能部を一つのハードウェアで実現してもよい。 The control device 40 is composed of a CPU (Central Processing Unit, also referred to as a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a processor) that executes programs stored in dedicated hardware or a storage device. . If the control device 40 is dedicated hardware, the control device 40 may be, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. is applicable. Each functional unit implemented by the control device 40 may be implemented by separate hardware, or each functional unit may be implemented by one piece of hardware.
　制御装置４０がＣＰＵの場合、制御装置４０が実行する各機能は、ソフトウェア、ファームウェア、又はソフトウェアとファームウェアとの組み合わせにより実現される。ソフトウェア及びファームウェアはプログラムとして記述され、記憶装置に格納される。ＣＰＵは、記憶装置に格納されたプログラムを読み出して実行することにより、各機能を実現する。なお、制御装置４０の機能の一部を専用のハードウェアで実現し、一部をソフトウェア又はファームウェアで実現するようにしてもよい。記憶装置は、ハードディスクとして構成されてもよいし、データを一時的に記憶することができるランダムアクセスメモリ（ＲＡＭ）等の揮発性記憶装置として構成されてもよい。また、記憶装置は、データを長期的に記憶することができるフラッシュメモリ等の不揮発性記憶装置として構成されてもよい。なお、本実施の形態１では、制御装置４０が室外機２０に設けられている場合について例示しているが、制御装置４０が室内機３０に設けられてもよいし、制御装置４０が外部ユニットに設けられてもよい。 When the control device 40 is a CPU, each function executed by the control device 40 is implemented by software, firmware, or a combination of software and firmware. Software and firmware are written as programs and stored in storage devices. The CPU implements each function by reading and executing a program stored in the storage device. A part of the functions of the control device 40 may be realized by dedicated hardware, and a part thereof may be realized by software or firmware. The storage device may be configured as a hard disk or as a volatile storage device such as a random access memory (RAM) capable of temporarily storing data. The storage device may also be configured as a non-volatile storage device such as a flash memory capable of long-term storage of data. In addition, although the case where the control device 40 is provided in the outdoor unit 20 is illustrated in the first embodiment, the control device 40 may be provided in the indoor unit 30, and the control device 40 may be an external unit. may be provided in
　（運転モード、冷房運転）
　次に、空気調和装置１００の運転モードについて説明する。先ず、冷房運転について説明する。冷房運転において、圧縮機１に吸入された冷媒は、圧縮機１によって圧縮されて高温且つ高圧のガス状態で吐出する。圧縮機１から吐出された高温且つ高圧のガス状態の冷媒は、流路切替装置２を通過して、凝縮器として作用する室外熱交換器３に流入し、室外熱交換器３において、室外送風機１１によって送られる室外空気と熱交換されて凝縮して液化する。凝縮された液状態の冷媒は、第１接続点５１において分岐する。第１接続点５１において分岐回路１００ｂに流入した冷媒は、逆止弁１３を通って冷媒熱交換器１４に至り、第２接続点５２において冷媒回路１００ａに流れる冷媒と合流する。第１接続点５１において分岐回路１００ｂに流入していない冷媒は、第２接続点５２を通過して膨張部５に流入し、膨張部５において膨張及び減圧されて低温且つ低圧の気液二相状態の冷媒となる。 (Operating mode, cooling operation)
Next, operation modes of the air conditioner 100 will be described. First, the cooling operation will be explained. In the cooling operation, the refrigerant sucked into the compressor 1 is compressed by the compressor 1 and discharged in a high-temperature and high-pressure gas state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 passes through the flow switching device 2 and flows into the outdoor heat exchanger 3 acting as a condenser. It is heat-exchanged with the outdoor air sent by 11 and condenses and liquefies. The condensed liquid state refrigerant branches at the first connection point 51 . The refrigerant flowing into the branch circuit 100b at the first connection point 51 passes through the check valve 13, reaches the refrigerant heat exchanger 14, and joins with the refrigerant flowing into the refrigerant circuit 100a at the second connection point 52. Refrigerant that has not flowed into the branch circuit 100b at the first connection point 51 passes through the second connection point 52 and flows into the expansion section 5, where it is expanded and decompressed in the expansion section 5 to produce a low-temperature, low-pressure gas-liquid two-phase refrigerant. state refrigerant.
　そして、気液二相状態の冷媒は、蒸発器として作用する室内熱交換器６に流入し、室内熱交換器６において、室内送風機１２によって送られる室内空気と熱交換されて蒸発してガス化する。このとき、室内空気が冷やされ、室内において冷房が実施される。蒸発した低温且つ低圧のガス状態の冷媒は、冷媒熱交換器１４に流入し、冷媒熱交換器１４において、分岐回路１００ｂに流れる冷媒と熱交換されて、更に蒸発してガス化する。その後、十分にガス化した冷媒は、流路切替装置２及びアキュムレータ７を通過して、圧縮機１に吸入される。 Then, the gas-liquid two-phase refrigerant flows into the indoor heat exchanger 6 acting as an evaporator, where it exchanges heat with the indoor air sent by the indoor blower 12 and evaporates into gas. do. At this time, the indoor air is cooled, and cooling is performed in the room. The evaporated low-temperature, low-pressure gaseous refrigerant flows into the refrigerant heat exchanger 14, where it is heat-exchanged with the refrigerant flowing in the branch circuit 100b, and further evaporated and gasified. After that, the sufficiently gasified refrigerant passes through the flow switching device 2 and the accumulator 7 and is sucked into the compressor 1 .
　（運転モード、暖房運転）
　次に、暖房運転について説明する。暖房運転において、圧縮機１に吸入された冷媒は、圧縮機１によって圧縮されて高温且つ高圧のガス状態で吐出する。圧縮機１から吐出された高温且つ高圧のガス状態の冷媒は、流路切替装置２及び冷媒熱交換器１４を通過して、凝縮器として作用する室内熱交換器６に流入し、室内熱交換器６において、室内送風機１２によって送られる室内空気と熱交換されて凝縮して液化する。このとき、室内空気が暖められ、室内において暖房が実施される。凝縮された液状態の冷媒は、膨張部５に流入し、膨張部５において膨張及び減圧されて低温且つ低圧の気液二相状態の冷媒となる。 (Operating mode, heating operation)
Next, the heating operation will be explained. In the heating operation, the refrigerant sucked into the compressor 1 is compressed by the compressor 1 and discharged in a high-temperature and high-pressure gas state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 passes through the flow switching device 2 and the refrigerant heat exchanger 14, flows into the indoor heat exchanger 6 acting as a condenser, and undergoes indoor heat exchange. In the vessel 6, heat is exchanged with indoor air sent by the indoor blower 12 to condense and liquefy. At this time, the indoor air is warmed, and heating is performed in the room. The condensed liquid refrigerant flows into the expansion section 5, where it is expanded and decompressed to become a low-temperature, low-pressure gas-liquid two-phase refrigerant.
　そして、気液二相状態の冷媒は、第２接続点５２に至る。ここで、分岐回路１００ｂには、逆止弁１３が設けられているため、第２接続点５２に到達した冷媒は、分岐回路１００ｂに流入しない。第２接続点５２を通過した冷媒は、第１接続点５１を通過して、蒸発器として作用する室外熱交換器３に流入し、室外熱交換器３において、室外送風機１１によって送られる室外空気と熱交換されて蒸発してガス化する。蒸発した低温且つ低圧のガス状態の冷媒は、流路切替装置２及びアキュムレータ７を通過して、圧縮機１に吸入される。 Then, the gas-liquid two-phase refrigerant reaches the second connection point 52 . Here, since the check valve 13 is provided in the branch circuit 100b, the refrigerant reaching the second connection point 52 does not flow into the branch circuit 100b. The refrigerant that has passed through the second connection point 52 passes through the first connection point 51 and flows into the outdoor heat exchanger 3 acting as an evaporator. In the outdoor heat exchanger 3, the outdoor air sent by the outdoor fan 11 is evaporates and gasifies. The vaporized low-temperature, low-pressure gaseous refrigerant passes through the flow switching device 2 and the accumulator 7 and is sucked into the compressor 1 .
　＜膨張部５の詰まり発生時の冷媒の動作＞
　冷房運転時に、複数の室内機３０のうちのいずれかが停止された場合、圧縮機１の動作は継続され、冷媒回路１００ａに冷媒が流通すると共に、制御装置４０により、停止された室内機３０の膨張部５が閉状態に制御され、室内送風機１２が停止する。膨張部５に異物等が挟まって詰まりが生じていると、室外熱交換器３から流出した高温の液状態の冷媒が膨張部５で遮断されず、膨張部５から漏れ出る。膨張部５から漏れ出た冷媒は、膨張部５により低圧の二相状態の冷媒になり、室内熱交換器６に到達する。 <Behavior of Refrigerant when Clogging of Expansion Unit 5 Occurs>
When any one of the plurality of indoor units 30 is stopped during cooling operation, the operation of the compressor 1 is continued, the refrigerant flows through the refrigerant circuit 100a, and the control device 40 controls the stopped indoor unit 30. is controlled to be in a closed state, and the indoor blower 12 is stopped. If the expansion section 5 is clogged with a foreign matter or the like, the high-temperature liquid state refrigerant flowing out of the outdoor heat exchanger 3 is not blocked by the expansion section 5 and leaks out from the expansion section 5 . The refrigerant leaking out from the expansion part 5 becomes a low-pressure two-phase refrigerant by the expansion part 5 and reaches the indoor heat exchanger 6 .
　室内送風機１２は停止しており、室内熱交換器６では熱交換は行われないため、冷媒は、室内空気から吸熱することができず、低圧の二相状態がガス状態にならず、二相状態のまま、室内熱交換器６から流出する。低圧の二相状態の冷媒は、冷媒熱交換器１４の第１流路１４ａを流通し、その過程で、分岐回路１００ｂの第２流路１４ｂを流れる高温の液状態の冷媒との間で熱交換が行われる。 Since the indoor fan 12 is stopped and heat exchange is not performed in the indoor heat exchanger 6, the refrigerant cannot absorb heat from the indoor air, and the low-pressure two-phase state does not become a gas state, and the two-phase state It flows out from the indoor heat exchanger 6 in this state. The low-pressure two-phase refrigerant flows through the first passage 14a of the refrigerant heat exchanger 14, and in the process heats up with the high-temperature liquid refrigerant flowing through the second passage 14b of the branch circuit 100b. exchange takes place.
　これにより、低圧の二相状態の冷媒は、蒸発してガス状態の冷媒となって、流路切替装置２を介してアキュムレータ７を流入し、その後、圧縮機１に吸入される。膨張部５の詰まりにより、膨張部５から意図せず液状態の冷媒が漏れ出ても、高温の液状態の冷媒が冷媒熱交換器１４に流れることによって、ガス状態の冷媒になって圧縮機１に吸入される。このように、冷媒熱交換器１４が設けられることによって、圧縮機１に液状態の冷媒が吸入され難くなり、エジェクタのような特別な装置を用いることなく、圧縮機１における液バックを防止することができる。 As a result, the low-pressure two-phase refrigerant evaporates into gaseous refrigerant, flows into the accumulator 7 via the flow path switching device 2 , and is then sucked into the compressor 1 . Even if the liquid state refrigerant unintentionally leaks from the expansion section 5 due to the clogging of the expansion section 5, the liquid state refrigerant at a high temperature flows to the refrigerant heat exchanger 14 and becomes a gaseous state refrigerant. 1 is inhaled. By providing the refrigerant heat exchanger 14 in this way, it becomes difficult for the refrigerant in a liquid state to be sucked into the compressor 1, and liquid backflow in the compressor 1 is prevented without using a special device such as an ejector. be able to.
　本実施の形態１によれば、冷媒熱交換器１４が、第１流路１４ａに流れる冷媒と第２流路１４ｂに流れる冷媒との間で熱交換する。このため、冷房運転の場合、第１流路１４ａに流れる冷媒が第２流路１４ｂに流れる冷媒によって温められる。これにより、第１流路１４ａに液状態の冷媒が存在していても、液状態の冷媒がガス状態の冷媒になる。従って、膨張部５に異常が発生しても、液バックを抑制することができる。 According to Embodiment 1, the refrigerant heat exchanger 14 exchanges heat between the refrigerant flowing through the first flow path 14a and the refrigerant flowing through the second flow path 14b. Therefore, in the cooling operation, the refrigerant flowing through the first flow path 14a is warmed by the refrigerant flowing through the second flow path 14b. As a result, even if liquid refrigerant exists in the first flow path 14a, the liquid refrigerant becomes gaseous refrigerant. Therefore, even if an abnormality occurs in the inflatable portion 5, liquid backflow can be suppressed.
実施の形態２．
　図３は、実施の形態２に係る空気調和装置２００を示す回路図である。本実施の形態２は、実施の形態１の冷媒熱交換器１４及び逆止弁１３が設けられておらず、冷媒流量調整弁１３ａが設けられている点で、実施の形態１と相違する。本実施の形態２では、実施の形態１と共通する部分は同一の符号を付して説明を省略し、実施の形態１との相違点を中心に説明する。 Embodiment 2.
FIG. 3 is a circuit diagram showing an air conditioner 200 according to Embodiment 2. As shown in FIG. Embodiment 2 differs from Embodiment 1 in that the refrigerant heat exchanger 14 and check valve 13 of Embodiment 1 are not provided, and a refrigerant flow rate adjustment valve 13a is provided. In the second embodiment, the same reference numerals are given to the parts that are common to the first embodiment, and the description thereof is omitted.
　図３に示すように、冷媒流量調整弁１３ａは分岐回路１００ｂに接続されている。冷媒流量調整弁１３ａは、分岐回路１００ｂに流れる冷媒の流量を調整するものである。 As shown in FIG. 3, the refrigerant flow control valve 13a is connected to the branch circuit 100b. The refrigerant flow control valve 13a adjusts the flow rate of the refrigerant flowing through the branch circuit 100b.
　空気調和装置２００は、更に、温度検出部１５を備えている。温度検出部１５は、圧縮機１の吸入側に設けられており、圧縮機１の吸入側に流れる冷媒の温度を検出するものである。 The air conditioner 200 further includes a temperature detector 15. The temperature detection unit 15 is provided on the suction side of the compressor 1 and detects the temperature of the refrigerant flowing on the suction side of the compressor 1 .
　制御装置４０は、温度検出部１５によって検出された温度が予め決められた閾値温度以上の場合、冷媒流量調整弁１３ａの開度を上げる。通例、液状の冷媒の温度の方が、ガス状態の冷媒の温度よりも高い。このため、本実施の形態２では、圧縮機１の吸入側に流れる冷媒の温度が閾値温度以上の場合、液状態の冷媒が多く液バックする可能性があると判断している。そして、液バックする可能性があると判断されたときに、冷媒流量調整弁１３ａの開度を上げることによって、分岐回路１００ｂ及び冷媒回路１００ａに流れる冷媒の流量を調整する。これにより、圧縮機１に液状態の冷媒が吸入され難くなり、エジェクタのような特別な装置を用いることなく、圧縮機１における液バックを防止することができる。 When the temperature detected by the temperature detection unit 15 is equal to or higher than a predetermined threshold temperature, the control device 40 increases the degree of opening of the refrigerant flow control valve 13a. Typically, the temperature of the liquid refrigerant is higher than the temperature of the gaseous refrigerant. For this reason, in Embodiment 2, when the temperature of the refrigerant flowing to the suction side of the compressor 1 is equal to or higher than the threshold temperature, it is determined that a large amount of liquid refrigerant may back up. Then, when it is determined that there is a possibility of liquid backflow, the flow rate of the refrigerant flowing through the branch circuit 100b and the refrigerant circuit 100a is adjusted by increasing the opening degree of the refrigerant flow rate control valve 13a. This makes it difficult for the refrigerant in a liquid state to be sucked into the compressor 1, and liquid backflow in the compressor 1 can be prevented without using a special device such as an ejector.
　（制御装置４０の動作）
　図４は、実施の形態２に係る制御装置４０の動作を示すフローチャートである。次に、制御装置４０の動作について説明する。図４に示すように、空気調和装置２００が冷房運転している場合、制御装置４０は、温度検出部１５によって検出された温度が閾値温度以上か否かを判定する（ステップＳＴ０１）。温度が閾値温度未満の場合（ステップＳＴ０１のＮｏ）、制御装置４０は、液バックする可能性が低いと判断して、冷媒流量調整弁１３ａの開度をゼロにする（ステップＳＴ０２）。一方、温度が閾値温度以上の場合（ステップＳＴ０１のＹｅｓ）、制御装置４０は、液バックする可能性があると判断して、冷媒流量調整弁１３ａの開度を上げる（ステップＳＴ０３）。これにより、圧縮機１に液状態の冷媒が吸入され難くなり、圧縮機１における液バックを防止することができる。 (Operation of control device 40)
FIG. 4 is a flow chart showing the operation of the control device 40 according to the second embodiment. Next, operation of the control device 40 will be described. As shown in FIG. 4, when the air conditioner 200 is in cooling operation, the control device 40 determines whether or not the temperature detected by the temperature detector 15 is equal to or higher than the threshold temperature (step ST01). If the temperature is less than the threshold temperature (No in step ST01), the control device 40 determines that the possibility of liquid backflow is low, and sets the opening degree of the refrigerant flow control valve 13a to zero (step ST02). On the other hand, if the temperature is equal to or higher than the threshold temperature (Yes in step ST01), the controller 40 determines that there is a possibility of liquid backflow, and increases the opening degree of the refrigerant flow control valve 13a (step ST03). This makes it difficult for the refrigerant in the liquid state to be sucked into the compressor 1 , and liquid backflow in the compressor 1 can be prevented.
　その後、制御装置４０は、温度検出部１５によって検出された温度が閾値温度未満か否かを判定する（ステップＳＴ０４）。温度が閾値温度以上の場合（ステップＳＴ０４のＮｏ）、制御装置４０は、液バックする可能性が未だあると判断して、ステップＳＴ０４に戻る。一方、温度が閾値温度未満の場合（ステップＳＴ０４のＹｅｓ）、制御装置４０は、液バックする可能性が低くなったと判断して、冷媒流量調整弁１３ａの開度をゼロにする（ステップＳＴ０５）。 After that, the control device 40 determines whether the temperature detected by the temperature detection section 15 is less than the threshold temperature (step ST04). If the temperature is equal to or higher than the threshold temperature (No in step ST04), the control device 40 determines that there is still a possibility of liquid backflow, and returns to step ST04. On the other hand, if the temperature is less than the threshold temperature (Yes in step ST04), the control device 40 determines that the possibility of liquid backflow has decreased, and sets the opening degree of the refrigerant flow control valve 13a to zero (step ST05). .
　本実施の形態２によれば、制御装置４０は、温度検出部１５によって検出された温度が予め決められた閾値温度以上の場合、冷媒流量調整弁１３ａの開度を上げる。これにより、圧縮機１に液状態の冷媒が吸入され難くなり、圧縮機１における液バックを防止することができる。 According to the second embodiment, the control device 40 increases the opening degree of the refrigerant flow rate adjustment valve 13a when the temperature detected by the temperature detection unit 15 is equal to or higher than a predetermined threshold temperature. This makes it difficult for the refrigerant in the liquid state to be sucked into the compressor 1 , and liquid backflow in the compressor 1 can be prevented.
　なお、本実施の形態２では、冷媒熱交換器１４及び逆止弁１３が設けられていない場合について例示しているが、冷媒熱交換器１４及び逆止弁１３が設けられていてもよい。この場合、液バックする可能性に応じて、冷媒流量調整弁１３ａの制御と冷媒熱交換器１４による制御とを併用することができる。 Although the second embodiment exemplifies the case where the refrigerant heat exchanger 14 and the check valve 13 are not provided, the refrigerant heat exchanger 14 and the check valve 13 may be provided. In this case, the control of the refrigerant flow control valve 13a and the control of the refrigerant heat exchanger 14 can be used together according to the possibility of liquid backflow.
　１　圧縮機、２　流路切替装置、３　室外熱交換器、４　冷媒配管、５　膨張部、６　室内熱交換器、７　アキュムレータ、８　高圧圧力センサ、９　低圧圧力センサ、１０　室内機配管温度センサ、１１　室外送風機、１２　室内送風機、１３　逆止弁、１３ａ　冷媒流量調整弁、１４　冷媒熱交換器、１４ａ　第１流路、１４ｂ　第２流路、１５　温度検出部、２０　室外機、２１　流入管、２２　流出管、２３　小孔、３０　室内機、４０　制御装置、５１　第１接続点、５２　第２接続点、１００　空気調和装置、１００ａ　冷媒回路、１００ｂ　分岐回路、２００　空気調和装置。 1 compressor, 2 channel switching device, 3 outdoor heat exchanger, 4 refrigerant pipe, 5 expansion unit, 6 indoor heat exchanger, 7 accumulator, 8 high pressure sensor, 9 low pressure sensor, 10 indoor unit pipe temperature sensor, 11 outdoor fan, 12 indoor fan, 13 check valve, 13a refrigerant flow rate adjustment valve, 14 refrigerant heat exchanger, 14a first flow path, 14b second flow path, 15 temperature detector, 20 outdoor unit, 21 inflow pipe, 22 outflow pipe, 23 small hole, 30 indoor unit, 40 control device, 51 first connection point, 52 second connection point, 100 air conditioner, 100a refrigerant circuit, 100b branch circuit, 200 air conditioner.

Claims (4)

  1. 　圧縮機、室外熱交換器、膨張部及び室内熱交換器が冷媒配管により順次接続され、冷媒が循環する冷媒回路と、
    　前記冷媒回路における前記室外熱交換器と前記膨張部との間の前記室外熱交換器側である第１接続点から分岐し、前記室外熱交換器と前記膨張部との間の前記膨張部側である第２接続点に合流する分岐回路と、
    　前記冷媒回路における前記圧縮機と前記室内熱交換器との間の第１流路に流れる冷媒と、前記分岐回路の第２流路に流れる冷媒との間で熱交換する冷媒熱交換器と、
    　を備える空気調和装置。     a refrigerant circuit in which the compressor, the outdoor heat exchanger, the expansion section, and the indoor heat exchanger are sequentially connected by refrigerant piping and the refrigerant circulates;
    Branching from a first connection point on the outdoor heat exchanger side between the outdoor heat exchanger and the expansion section in the refrigerant circuit, the expansion section side between the outdoor heat exchanger and the expansion section a branch circuit that merges with a second connection point that is
    a refrigerant heat exchanger that exchanges heat between refrigerant flowing through a first flow path between the compressor and the indoor heat exchanger in the refrigerant circuit and refrigerant flowing through a second flow path of the branch circuit;
    An air conditioner with
  2. 　前記分岐回路に設けられ、前記第１接続点側から前記第２接続点側に冷媒が流れることを許容し、前記第２接続点側から前記第１接続点側に冷媒が流れることを抑制する逆止弁を更に備える
    　請求項１記載の空気調和装置。     Provided in the branch circuit, allowing refrigerant to flow from the first connection point side to the second connection point side, and suppressing refrigerant flow from the second connection point side to the first connection point side The air conditioner according to claim 1, further comprising a check valve.
  3. 　前記分岐回路に接続され、前記分岐回路に流れる冷媒の流量を調整する冷媒流量調整弁と、
    　前記圧縮機の吸入側に流れる冷媒の温度を検出する温度検出部と、
    　前記温度検出部によって検出された温度が予め決められた閾値温度以上の場合、前記冷媒流量調整弁の開度を上げる制御装置と、を更に備える
    　請求項１又は２記載の空気調和装置。     a refrigerant flow rate adjustment valve connected to the branch circuit and adjusting the flow rate of the refrigerant flowing through the branch circuit;
    a temperature detection unit that detects the temperature of the refrigerant flowing to the suction side of the compressor;
    The air conditioner according to claim 1 or 2, further comprising a control device that increases the degree of opening of the refrigerant flow control valve when the temperature detected by the temperature detection unit is equal to or higher than a predetermined threshold temperature.
  4. 　圧縮機、室外熱交換器、膨張部及び室内熱交換器が冷媒配管により順次接続され、冷媒が循環する冷媒回路と、
    　前記冷媒回路における前記室外熱交換器と前記膨張部との間の前記室外熱交換器側である第１接続点から分岐し、前記室外熱交換器と前記膨張部との間の前記膨張部側である第２接続点に合流する分岐回路と、
    　前記分岐回路に接続され、前記分岐回路に流れる冷媒の流量を調整する冷媒流量調整弁と、
    　前記圧縮機の吸入側に流れる冷媒の温度を検出する温度検出部と、
    　前記温度検出部によって検出された温度が予め決められた閾値温度以上の場合、前記冷媒流量調整弁の開度を上げる制御装置と、
    　を備える空気調和装置。     a refrigerant circuit in which the compressor, the outdoor heat exchanger, the expansion section, and the indoor heat exchanger are sequentially connected by refrigerant piping and the refrigerant circulates;
    Branching from a first connection point on the outdoor heat exchanger side between the outdoor heat exchanger and the expansion section in the refrigerant circuit, the expansion section side between the outdoor heat exchanger and the expansion section a branch circuit that merges with a second connection point that is
    a refrigerant flow rate adjustment valve connected to the branch circuit and adjusting the flow rate of the refrigerant flowing through the branch circuit;
    a temperature detection unit that detects the temperature of the refrigerant flowing to the suction side of the compressor;
    a control device that increases the degree of opening of the refrigerant flow control valve when the temperature detected by the temperature detection unit is equal to or higher than a predetermined threshold temperature;
    An air conditioner with
PCT/JP2021/043824 2021-11-30 2021-11-30 Air conditioning device WO2023100233A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2023564291A JPWO2023100233A1 (en) 2021-11-30 2021-11-30
PCT/JP2021/043824 WO2023100233A1 (en) 2021-11-30 2021-11-30 Air conditioning device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2021/043824 WO2023100233A1 (en) 2021-11-30 2021-11-30 Air conditioning device

Publications (1)

Publication Number Publication Date
WO2023100233A1 true WO2023100233A1 (en) 2023-06-08

Family

ID=86611744

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/043824 WO2023100233A1 (en) 2021-11-30 2021-11-30 Air conditioning device

Country Status (2)

Country Link
JP (1) JPWO2023100233A1 (en)
WO (1) WO2023100233A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59118975U (en) * 1983-02-01 1984-08-10 三菱重工業株式会社 Refrigeration equipment
JPH06213518A (en) * 1993-01-13 1994-08-02 Hitachi Ltd Heat pump type air conditioner for mixed refrigerant
JP2008121977A (en) * 2006-11-13 2008-05-29 Mitsubishi Electric Corp Heat pump water heater
JP2008175430A (en) * 2007-01-17 2008-07-31 Matsushita Electric Ind Co Ltd Air conditioner
JP2017053548A (en) * 2015-09-10 2017-03-16 ジョンソンコントロールズ ヒタチ エア コンディショニング テクノロジー（ホンコン）リミテッド Air conditioner
JP2018096621A (en) * 2016-12-14 2018-06-21 三菱重工サーマルシステムズ株式会社 Refrigerant circuit system and process of control for refrigerant circuit system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59118975U (en) * 1983-02-01 1984-08-10 三菱重工業株式会社 Refrigeration equipment
JPH06213518A (en) * 1993-01-13 1994-08-02 Hitachi Ltd Heat pump type air conditioner for mixed refrigerant
JP2008121977A (en) * 2006-11-13 2008-05-29 Mitsubishi Electric Corp Heat pump water heater
JP2008175430A (en) * 2007-01-17 2008-07-31 Matsushita Electric Ind Co Ltd Air conditioner
JP2017053548A (en) * 2015-09-10 2017-03-16 ジョンソンコントロールズ ヒタチ エア コンディショニング テクノロジー（ホンコン）リミテッド Air conditioner
JP2018096621A (en) * 2016-12-14 2018-06-21 三菱重工サーマルシステムズ株式会社 Refrigerant circuit system and process of control for refrigerant circuit system

Also Published As

Publication number Publication date
JPWO2023100233A1 (en) 2023-06-08

Similar Documents

Publication Publication Date Title
JP5855129B2 (en) Outdoor unit and air conditioner
JP6792057B2 (en) Refrigeration cycle equipment
CN108027179B (en) Air conditioner
EP3059521B1 (en) Air conditioning device
EP3205954B1 (en) Refrigeration cycle device
EP3693680B1 (en) Refrigeration cycle apparatus
WO2019069422A1 (en) Air conditioning device
US10907866B2 (en) Refrigerant cycle apparatus and air conditioning apparatus including the same
EP3115715B1 (en) Refrigeration cycle system
EP3273188A1 (en) Control device, air conditioner, and controlling method
KR20190005445A (en) Method for controlling multi-type air conditioner
JP6246394B2 (en) Air conditioner
JP7224480B2 (en) Outdoor unit and refrigeration cycle equipment
KR101872783B1 (en) Outdoor heat exchanger
WO2023100233A1 (en) Air conditioning device
KR102390900B1 (en) Multi-type air conditioner and control method for the same
WO2017098655A1 (en) Refrigeration cycle device
JP7195449B2 (en) Outdoor unit and refrigeration cycle equipment
JP6250428B2 (en) Refrigeration cycle equipment
KR101891615B1 (en) Outdoor heat exchanger
JPWO2020234994A1 (en) Air conditioner
KR20070031653A (en) Process for preventing rising of pressure in multi type air conditioner
JP7493126B2 (en) Air conditioners
US20240027077A1 (en) Hybrid multi-air conditioning system and method for controlling a hybrid multi-air conditioning system
KR20220040221A (en) Multi-air conditioner for heating and cooling operations

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: 21966319

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2023564291

Country of ref document: JP