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CN-117029321-B - Air conditioning unit and control method thereof

CN117029321BCN 117029321 BCN117029321 BCN 117029321BCN-117029321-B

Abstract

The invention discloses an air conditioning unit and a control method thereof, wherein the air conditioning unit comprises a supercooling branch, a first air suction branch, a second air suction branch and a control valve component, wherein one end of the supercooling branch is connected with a supercooling refrigerant outlet of a supercooling device, the other end of the supercooling branch is connected with an inlet of a gas-liquid separator, one end of the first air suction branch is connected with an outlet of the gas-liquid separator, the other end of the first air suction branch is connected with a pipeline between an outdoor heat exchanger and an electronic expansion valve, one end of the second air suction branch is connected with an air suction port of a compressor, the other end of the second air suction branch is connected with a pipeline between a main four-way valve and an indoor heat exchanger, and the control valve component is used for controlling the conduction of the supercooling branch, the first air suction branch and the second air suction branch under a gas-liquid separation mode, and the supercooling refrigerant of the supercooling device enters the compressor after passing through the gas-liquid separator and the outdoor heat exchanger. The invention solves the problems of low refrigerant circulation and easy liquid impact caused by the air-conditioning unit easy gas separation and liquid accumulation in the ultralow temperature environment in the prior art, avoids liquid impact caused by the direct entry of liquid refrigerant into the compressor, and improves the reliability of the compressor and the performance of the air-conditioning unit.

Inventors

  • QIU TIAN
  • JIAO HUACHAO
  • GAO HAN
  • JIN MENGMENG

Assignees

  • 珠海格力电器股份有限公司

Dates

Publication Date
20260505
Application Date
20230818

Claims (8)

  1. 1. The air conditioning unit control method comprises a compressor (1), a main four-way valve (2), an outdoor heat exchanger (3), an electronic expansion valve (4), a subcooler (5), an indoor heat exchanger and a gas-liquid separator (6) which are sequentially connected, and is characterized by further comprising a subcooling branch, a control valve assembly and a control valve assembly, wherein one end of the subcooling branch is connected with a subcooling refrigerant outlet of the subcooler (5), the other end of the subcooling branch is connected with an inlet of the gas-liquid separator (6), one end of the first suction branch is connected with an outlet of the gas-liquid separator (6), the other end of the first suction branch is connected with a pipeline between the outdoor heat exchanger (3) and the electronic expansion valve (4), one end of the second suction branch is connected with an air suction port of the compressor (1), and the other end of the second suction branch is connected with a pipeline between the main four-way valve (2) and the indoor heat exchanger, and the control valve assembly is used for controlling the subcooling branch, the first suction branch and the second suction branch to be conducted under a gas-liquid separation mode, and the subcooling refrigerant of the subcooling device (5) enters the compressor (1) through the gas-liquid separator (3) and the air-liquid separator (3); The method comprises the following steps: Judging whether the air conditioning unit meets the air separation liquid entering condition after entering a heating mode, wherein the air conditioning unit comprises at least one of the following steps that the continuous downtime of the air conditioning unit is greater than or equal to a first preset time, the air conditioning unit is restarted after the heating oil return operation is finished, and the air conditioning unit is restarted after the heating defrosting operation is finished, wherein the outdoor environment temperature is less than or equal to a preset temperature threshold; if so, controlling the air conditioning unit to enter an air-separating liquid discharging mode through a control valve assembly, and then judging whether the air conditioning unit meets an air-separating liquid discharging exiting condition, wherein the air-separating liquid discharging exiting condition at least comprises one of the following steps that the high pressure of a system is more than or equal to a preset high pressure, the superheat degree of an outlet of a gas-liquid separator is more than a preset temperature, and the running time of the air conditioning unit after entering the air-separating liquid is more than or equal to a second preset time; Otherwise, controlling the operation of the control valve assembly according to the heating mode.
  2. 2. The air conditioning unit control method according to claim 1, wherein the control valve assembly includes: the supercooling valve (7) is positioned on the supercooling branch and used for controlling the on-off of the supercooling branch; And the second air suction valve (8) is positioned on the second air suction branch and used for controlling the on-off of the second air suction branch.
  3. 3. The air conditioning unit control method according to claim 2, wherein the control valve assembly further comprises: the first air suction valve (9) is positioned on the first air suction branch and is used for controlling the on-off of the first air suction branch; And the third suction valve (10) is positioned on a pipeline between the outlet of the gas-liquid separator (6) and the suction port of the compressor (1) and between a first connecting point and the suction port of the compressor (1), wherein the first connecting point is a connecting point of the outlet of the gas-liquid separator (6) and the first suction branch.
  4. 4. The air conditioning unit control method according to claim 3, wherein the control valve assembly further comprises: And an air suction four-way valve (11), wherein an outlet of the gas-liquid separator (6), the first air suction branch and the second air suction branch are connected with an air suction port of the compressor (1) through the air suction four-way valve (11).
  5. 5. The air conditioning unit control method according to claim 4, wherein the air conditioning unit further comprises: And a fourth suction valve (12) which is positioned on a pipeline between the main four-way valve (2) and the gas-liquid separator (6) and is positioned between a second connecting point and the main four-way valve (2), wherein the second connecting point is positioned between the supercooling valve (7) and the inlet of the gas-liquid separator (6).
  6. 6. The air conditioning unit control method according to claim 2, characterized in that the air conditioning unit further comprises: a supercooling electronic expansion valve (13) which is positioned on a supercooling refrigerant pipeline of the supercooler (5); the temperature sensor (14) is positioned at the outlet of the gas-liquid separator (6) and is used for detecting the temperature of the gas outlet; the first pressure sensor (15) is positioned at the inlet of the gas-liquid separator (6) and is used for detecting the low pressure of the system; and the second pressure sensor (16) is positioned at the exhaust port of the compressor (1) and is used for detecting the high pressure of the system.
  7. 7. The method according to claim 5, wherein controlling the air conditioning unit to enter a gas-liquid separation mode by controlling a valve assembly includes controlling a third suction valve and a fourth suction valve to be closed, a first suction valve and a second suction valve to be opened and controlling a supercooling valve to be opened and an electronic expansion valve to be closed, or controlling the fourth suction valve to be closed, the second suction valve to be opened and the supercooling valve to be opened and controlling a suction four-way valve to communicate an outlet of the gas-liquid separator with the first suction branch and the second suction branch to communicate with a suction port of the compressor; The operation of the control valve assembly is controlled according to the heating mode, and the control valve assembly comprises the steps of controlling a third air suction valve and a fourth air suction valve to be opened, controlling a first air suction valve and a second air suction valve to be closed, controlling a supercooling valve to be closed, and controlling an electronic expansion valve to be opened, or controlling the fourth air suction valve to be opened, controlling the second air suction valve to be closed, controlling the supercooling valve to be closed, and controlling an air suction four-way valve to communicate an outlet of the gas-liquid separator with an air suction port of the compressor.
  8. 8. A storage medium containing computer executable instructions, which when executed by a computer processor are for performing the air conditioning unit control method of any of claims 1 to 7.

Description

Air conditioning unit and control method thereof Technical Field The invention relates to the technical field of air conditioners, in particular to an air conditioner unit and a control method thereof. Background With the continuous development of the refrigeration industry and the increase of user demands, the requirements of users on air-conditioning products are also higher and higher, and particularly, a part of ultralow-temperature areas also have huge heating demands, so that the air-conditioning products are required to maintain reliability in an ultralow-temperature environment. However, at ultra-low ambient temperatures, the refrigerant in the air conditioning unit is easily deposited in a liquid state in the gas-liquid separator (gas separator). When the unit is started, liquid refrigerant is easy to generate liquid impact after entering the compressor, the reliability of the compressor is reduced, the circulation amount of the refrigerant of the system is reduced after gas is separated and accumulated, the refrigerant circulation of the system is built to be slow when the unit is started, and the performance of the air conditioning unit is reduced. Aiming at the problems that an air conditioning unit is easy to gas-separate hydrops in an ultralow temperature environment in the related technology, so that a refrigerant circulates slowly and is easy to liquid impact during starting, no effective solution is proposed at present. Disclosure of Invention The invention provides an air conditioning unit and a control method thereof, which at least solve the problems that in the prior art, the air conditioning unit is easy to gas-separate liquid accumulation in an ultralow temperature environment, so that a refrigerant circulates slowly and is easy to hit liquid during starting. To solve the above technical problem, according to an aspect of the embodiments of the present invention, there is provided an air conditioning unit, including: the compressor, the main four-way valve, the outdoor heat exchanger, the electronic expansion valve, the subcooler, the indoor heat exchanger and the gas-liquid separator are connected in sequence; one end of the supercooling branch is connected with a supercooling refrigerant outlet of the supercooler, and the other end of the supercooling branch is connected with an inlet of the gas-liquid separator; One end of the first air suction branch is connected with an outlet of the gas-liquid separator, and the other end of the first air suction branch is connected with a pipeline between the outdoor heat exchanger and the electronic expansion valve; one end of the second air suction branch is connected with the air suction port of the compressor, and the other end of the second air suction branch is connected with a pipeline between the main four-way valve and the indoor heat exchanger; And the control valve assembly is used for controlling the conduction of the supercooling branch, the first air suction branch and the second air suction branch in the air separation liquid discharging mode, and supercooling refrigerant of the supercooler enters the compressor after passing through the air-liquid separator and the outdoor heat exchanger. Further, the control valve assembly includes: the supercooling valve is positioned on the supercooling branch and used for controlling the on-off of the supercooling branch; The second air suction valve is positioned on the second air suction branch and used for controlling the on-off of the second air suction branch. Further, the control valve assembly further includes: the first air suction valve is positioned on the first air suction branch and used for controlling the on-off of the first air suction branch; And the third suction valve is positioned on a pipeline between the outlet of the gas-liquid separator and the suction port of the compressor and between the first connecting point and the suction port of the compressor, wherein the first connecting point is a connecting point of the outlet of the gas-liquid separator and the first suction branch. Further, the control valve assembly further includes: And the outlet of the gas-liquid separator, the first air suction branch and the second air suction branch are connected with the air suction port of the compressor through the air suction four-way valve. Further, the method further comprises the following steps: And the fourth suction valve is positioned on a pipeline between the main four-way valve and the gas-liquid separator and between the second connecting point and the main four-way valve, wherein the second connecting point is positioned between the supercooling valve and the inlet of the gas-liquid separator. Further, the method further comprises the following steps: The supercooling electronic expansion valve is positioned on a supercooling refrigerant pipeline of the supercooler; the temperature sensor is positioned at the outlet of the gas-liquid separator and used for detecting