Air conditioner control method and device, air conditioner, storage medium and program product

Abstract

The invention discloses an air conditioner control method and device, an air conditioner, a storage medium and a computer program product. A liquid separator is arranged at an air conditioner compressor; the method comprises the steps that whether a liquid refrigerant is contained in the liquid separator or not is determined according to the pressure of the upper portion in the liquid separator and the temperature of the bottom in the liquid separator; and if it is determined that the liquid dispenser does not contain the liquid refrigerant, the opening degree of the electronic expansion valve is controlled according to the temperature and pressure of the upper portion in the liquid dispenser and the superheat degree of the evaporator. According to the scheme, the opening degree of the electronic expansion valve is controlled according to the pressure and temperature in the liquid separator and the superheat degree of the evaporator, it is ensured that the liquid refrigerant always exists in the liquid separator, and therefore the air suction temperature of the compressor is reduced, the refrigerant circulation amount of the system is increased, and the energy efficiency of the system is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioning, and specifically relates to a control method, device, air conditioner, storage medium and computer program product of an air conditioner, and in particular to a control method, device, air conditioner, storage medium and computer program product of a liquid level of a compressor distributor of an air conditioner. Background Art

[0002] During the operation of the air conditioner, due to the necessity of the system, the evaporator outlet always maintains a certain degree of superheat, and the refrigerant further increases the superheat after passing through the long connecting pipe between the evaporator and the compressor distributor, resulting in no liquid refrigerant in the distributor, and then the suction and exhaust temperatures increase, reducing the actual amount of refrigerant participating in the circulation, which not only reduces the system energy efficiency, but also further deteriorates the internal environment of the compressor.

[0003] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The object of the present invention is to provide an air conditioner control method, device, air conditioner, storage medium and computer program product to solve the problem in related schemes that there is no liquid refrigerant in the compressor distributor, resulting in a reduction in the amount of circulating refrigerant in the system and a decrease in the energy efficiency of the system. The purpose of the present invention is to control the opening of the electronic expansion valve according to the pressure and temperature in the distributor and the superheat of the evaporator to ensure that there is always liquid refrigerant in the distributor, thereby reducing the compressor suction temperature, increasing the refrigerant circulation amount of the system, and improving the energy efficiency of the system.

[0005] The present invention provides a control method for an air conditioner, the air conditioner comprising a compressor, an electronic expansion valve, and an evaporator; a liquid separator is provided at the compressor; the method comprises: obtaining the temperature and pressure of the upper part of the liquid separator, the temperature of the bottom part of the liquid separator, and the superheat of the evaporator; determining whether the liquid separator contains liquid refrigerant according to the pressure of the upper part of the liquid separator and the temperature of the bottom part of the liquid separator; if it is determined that the liquid separator does not contain liquid refrigerant, controlling the opening of the electronic expansion valve according to the temperature and pressure of the upper part of the liquid separator and the superheat of the evaporator.

[0006] In some embodiments, whether the liquid separator contains liquid refrigerant is determined based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator, including: calculating the superheat of the bottom part of the liquid separator based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator; judging whether the superheat of the bottom part of the liquid separator is greater than a preset first superheat; if the superheat of the bottom part of the liquid separator is greater than the preset first superheat, determining that the liquid separator does not contain liquid refrigerant; if the superheat of the bottom part of the liquid separator is less than or equal to the preset first superheat, determining that the liquid separator contains liquid refrigerant.

[0007] In some embodiments, the opening of the electronic expansion valve is controlled according to the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator, including: judging the relationship between the superheat of the evaporator and a preset second superheat; if the superheat of the evaporator is greater than the preset second superheat, increasing the opening of the electronic expansion valve; if the superheat of the evaporator is less than or equal to the preset second superheat, controlling the opening of the electronic expansion valve according to the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator.

[0008] In some embodiments, the opening of the electronic expansion valve is controlled according to the temperature and pressure of the upper inner part of the liquid separator and the superheat of the evaporator, including: calculating the superheat of the upper inner part of the liquid separator according to the temperature and pressure of the upper inner part of the liquid separator; judging whether the superheat of the upper inner part of the liquid separator is equal to a preset third superheat; if the superheat of the upper inner part of the liquid separator is equal to the preset third superheat, controlling the opening of the electronic expansion valve according to the superheat of the evaporator; if the superheat of the upper inner part of the liquid separator is not equal to the preset third superheat, keeping the opening of the electronic expansion valve unchanged.

[0009] In some embodiments, the opening of the electronic expansion valve is controlled according to the superheat of the evaporator, including: judging the relationship between the superheat of the evaporator and a preset second superheat; if the superheat of the evaporator is less than or equal to the preset second superheat, reducing the opening of the electronic expansion valve; if the superheat of the evaporator is greater than the preset second superheat, maintaining the opening of the electronic expansion valve unchanged, and then re-determining whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator.

[0010] Matching the above method, the present invention provides a control device for an air conditioner on the other hand, the air conditioner includes a compressor, an electronic expansion valve, and an evaporator; a liquid separator is provided at the compressor; the device includes: an acquisition unit, configured to acquire the temperature and pressure of the upper part of the liquid separator, the temperature of the bottom part of the liquid separator, and the superheat of the evaporator; a control unit, configured to determine whether the liquid separator contains liquid refrigerant based on the pressure of the upper part of the liquid separator and the temperature of the bottom part of the liquid separator; the control unit is also configured to control the opening of the electronic expansion valve based on the temperature and pressure of the upper part of the liquid separator and the superheat of the evaporator if it is determined that the liquid separator does not contain liquid refrigerant.

[0011] In some embodiments, the control unit determines whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator, including: calculating the superheat of the bottom part of the liquid separator based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator; judging whether the superheat of the bottom part of the liquid separator is greater than a preset first superheat; if the superheat of the bottom part of the liquid separator is greater than the preset first superheat, determining that the liquid separator does not contain liquid refrigerant; if the superheat of the bottom part of the liquid separator is less than or equal to the preset first superheat, determining that the liquid separator contains liquid refrigerant.

[0012] In some embodiments, the control unit controls the opening of the electronic expansion valve according to the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator, including: judging the relationship between the superheat of the evaporator and a preset second superheat; if the superheat of the evaporator is greater than the preset second superheat, increasing the opening of the electronic expansion valve; if the superheat of the evaporator is less than or equal to the preset second superheat, controlling the opening of the electronic expansion valve according to the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator.

[0013] In some embodiments, the control unit controls the opening of the electronic expansion valve according to the temperature and pressure of the upper part of the liquid separator and the superheat of the evaporator, including: calculating the superheat of the upper part of the liquid separator according to the temperature and pressure of the upper part of the liquid separator; judging whether the superheat of the upper part of the liquid separator is equal to a preset third superheat; if the superheat of the upper part of the liquid separator is equal to the preset third superheat, controlling the opening of the electronic expansion valve according to the superheat of the evaporator; if the superheat of the upper part of the liquid separator is not equal to the preset third superheat, keeping the opening of the electronic expansion valve unchanged.

[0014] In some embodiments, the control unit controls the opening of the electronic expansion valve according to the superheat of the evaporator, including: judging the relationship between the superheat of the evaporator and a preset second superheat; if the superheat of the evaporator is less than or equal to the preset second superheat, reducing the opening of the electronic expansion valve; if the superheat of the evaporator is greater than the preset second superheat, keeping the opening of the electronic expansion valve unchanged, and then re-determining whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator.

[0015] Matching the above device, the present invention provides an air conditioner on another aspect, including: the control device of the air conditioner mentioned above.

[0016] In accordance with the above method, the present invention provides a storage medium on another aspect, wherein the storage medium includes a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute the above-mentioned air conditioning control method.

[0017] In accordance with the above method, the present invention provides a computer program product on another aspect, wherein the computer program product includes a computer program, and when the computer program product is processed and executed, the steps of the above air conditioner control method are implemented.

[0018] According to the scheme of the present invention, during the operation of the air conditioner, whether the liquid separator contains liquid refrigerant is determined based on the pressure in the upper part of the liquid separator and the temperature in the bottom of the liquid separator; if the liquid separator does not contain liquid refrigerant, the opening of the air conditioner electronic expansion valve is controlled based on the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator, so as to ensure that there is always some liquid refrigerant in the liquid separator, reduce the suction temperature of the compressor, improve the operating environment inside the compressor, increase the mass flow rate of the refrigerant circulating in the system, and improve the energy efficiency of the system.

[0019] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a flow chart of an embodiment of a method for controlling an air conditioner of the present invention;

[0022] Figure 2 A schematic structural diagram of an embodiment of a control device for an air conditioner of the present invention;

[0023] Figure 3 is a system structure diagram of the air conditioner of the present invention;

[0024] Figure 4 The figure is a flow chart of a method for controlling the liquid level of a liquid distributor of an air conditioner according to the present invention.

[0025] In conjunction with the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0026] 1- compressor; 2- condenser; 3- liquid storage device; 4- electronic expansion valve; 5- evaporator; 6- liquid distributor; 102- acquisition unit; 104- control unit. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] According to an embodiment of the present invention, a control method for an air conditioner is provided, wherein the air conditioner comprises a compressor, an electronic expansion valve, and an evaporator; a liquid distributor is provided at the compressor. Figure 3 As shown, a liquid separator 6 is provided at the air inlet of the compressor 1. When the air conditioner is running, the high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the liquid separator 6 after passing through the condenser 2, the liquid reservoir 3, the electronic expansion valve 4, and the evaporator 5 in sequence. In the liquid separator 6, the liquid refrigerant is separated from the gaseous refrigerant. The liquid refrigerant is in the lower part of the liquid separator, and the gaseous refrigerant is in the upper part of the liquid separator. Then the gaseous refrigerant enters the compressor 1 for compression. If there is no liquid refrigerant in the liquid separator, the gaseous refrigerant from the evaporator cannot be heat exchanged to cool down, thereby increasing the suction and exhaust temperature, increasing the specific volume of the refrigerant, reducing the amount of refrigerant circulating in the system, and reducing the system energy efficiency. Therefore, in order to maintain stable and efficient operation of the air conditioner, it is necessary to ensure that the liquid separator contains a certain amount of liquid refrigerant.

[0029] like Figure 1 The flowchart of an embodiment of the method of the present invention is shown in FIG. The air conditioner control method may include: steps S110 to S130.

[0030] In step S110, the temperature and pressure of the upper part of the liquid separator, the temperature of the bottom of the liquid separator, and the superheat of the evaporator are obtained.

[0031] The liquid distributor is equipped with a temperature sensor and a pressure sensor. The sensor for detecting the upper temperature is set at the same level as the steel pipe inlet of the liquid distributor, and the sensor for detecting the bottom temperature is set at the lowest position of the lower cylinder of the liquid distributor. In the liquid distributor, the temperature and pressure of the upper part can be regarded as the temperature and pressure of the gaseous refrigerant, and the temperature of the bottom can be regarded as the temperature of the liquid refrigerant. If the liquid distributor does not contain liquid refrigerant, but only gaseous refrigerant, the pressure of the upper part and the bottom are the same.

[0032] The superheat of the evaporator can be calculated by detecting the pressure and temperature at the outlet of the evaporator. Specifically, according to the pressure at the outlet of the evaporator, the pressure-temperature comparison table is searched to determine the saturation temperature corresponding to the pressure. The result of subtracting the saturation temperature from the outlet temperature of the evaporator is the superheat of the evaporator.

[0033] In step S120, it is determined whether the liquid separator contains liquid refrigerant according to the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator.

[0034] The superheat at the bottom can be calculated based on the pressure at the top of the liquid distributor and the temperature at the bottom. The calculation method is the same as that of the evaporator superheat. The superheat at the bottom of the liquid distributor can be used to determine whether the refrigerant at the bottom is completely evaporated, thereby determining whether there is liquid refrigerant in the liquid distributor.

[0035] In some embodiments, in step S120, the specific process of determining whether the liquid separator contains liquid refrigerant according to the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator includes: calculating the superheat of the bottom part of the liquid separator according to the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator, specifically determining the saturation temperature according to the pressure in the upper part of the liquid separator, and the result of subtracting the saturation temperature from the temperature in the bottom part of the liquid separator is the superheat of the bottom part of the liquid separator; judging whether the superheat of the bottom part of the liquid separator is greater than a preset first superheat; if the superheat of the bottom part of the liquid separator is greater than the preset first superheat, determining that the liquid separator does not contain liquid refrigerant; if the superheat of the bottom part of the liquid separator is less than or equal to the preset first superheat, determining that the liquid separator contains liquid refrigerant.

[0036] The refrigerant at the top of the liquid separator is in gaseous state, and the corresponding saturation temperature is high. If the temperature at the bottom of the liquid separator is greater than the saturation temperature, it means that the refrigerant at the bottom is already in a saturated state, and there is no liquid refrigerant. At this time, the superheat at the bottom is greater than 0, and the first superheat is preset to 0. Therefore, when the superheat at the bottom of the liquid separator is greater than 0, it is considered that there is no liquid refrigerant in the liquid separator; when the superheat at the bottom of the liquid separator is ≤0, it is considered that there is liquid refrigerant in the liquid separator.

[0037] If the liquid distributor does not contain liquid refrigerant, the liquid level in the liquid distributor is 0. Therefore, the liquid level in the liquid distributor may be detected by setting a liquid level sensor, and whether the liquid distributor contains liquid refrigerant may be determined based on the liquid level.

[0038] At step S130, if it is determined that the liquid separator does not contain liquid refrigerant, the opening of the electronic expansion valve is controlled according to the temperature and pressure of the upper part of the liquid separator and the superheat of the evaporator.

[0039] If there is no liquid refrigerant in the liquid distributor, it means that the refrigerant superheat is too high. It is necessary to reduce the compressor suction superheat as much as possible while ensuring that the compressor suction does not carry liquid, so as to increase the actual circulating refrigerant amount of the compressor. By controlling the opening of the electronic expansion valve, the evaporation degree of the refrigerant in the evaporator can be adjusted, thereby reducing the superheat and generating a certain amount of liquid refrigerant in the liquid distributor. If there is liquid refrigerant in the liquid distributor, the air conditioner is operating normally.

[0040] By controlling the liquid level of the liquid refrigerant in the liquid distributor, it is ensured that there is always some liquid refrigerant in the liquid distributor. When the gaseous refrigerant from the evaporator passes through the liquid distributor, it exchanges heat with the refrigerant in the liquid distributor, thereby reducing the temperature of the refrigerant at the suction port of the compressor pump and increasing the mass flow rate per unit displacement. When the compressor displacement remains unchanged, the mass flow rate of the refrigerant circulating in the system is increased, thereby increasing the cooling capacity of the system. In addition, since the temperature of the suction port of the compressor pump is reduced, the operating environment inside the compressor can be improved, the exhaust temperature of the compressor is reduced, and the energy efficiency of the compressor can be improved.

[0041] In some embodiments, in step S130, the specific process of controlling the opening of the electronic expansion valve according to the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator includes: steps S210 to S230.

[0042] Step S210, determining the magnitude relationship between the superheat degree of the evaporator and a preset second superheat degree.

[0043] Step S220: If the superheat of the evaporator is greater than a preset second superheat, increasing the opening of the electronic expansion valve.

[0044] Step S230: If the superheat of the evaporator is less than or equal to a preset second superheat, the opening of the electronic expansion valve is controlled according to the temperature and pressure of the upper part of the liquid distributor and the superheat of the evaporator.

[0045] In order to increase the amount of liquid refrigerant in the liquid separator, it is necessary to make the refrigerant incompletely evaporate in the evaporator, so that the refrigerant flowing out of the evaporator is in a gas-liquid mixed state, and then the gas-liquid separation is carried out in the liquid separator, and the liquid refrigerant remains in the liquid separator.

[0046] In order to prevent the refrigerant from completely evaporating in the evaporator, the superheat of the evaporator needs to be reduced. At this time, the opening of the electronic expansion valve is increased to increase the refrigerant flow rate into the evaporator, so that the refrigerant evaporates incompletely. The second superheat is preset to 0.

[0047] When the refrigerant does not completely evaporate in the evaporator, liquid refrigerant begins to be produced in the liquid separator. At this time, continue to detect the temperature and pressure in the upper part of the liquid separator to determine whether the liquid refrigerant in the liquid separator has reached the maximum amount. After the liquid refrigerant reaches the maximum amount, control the opening of the electronic expansion valve according to the superheat of the evaporator to restore the evaporator to the state before adjusting the liquid level in the liquid separator.

[0048] In some embodiments, in step S230, the specific process of controlling the opening of the electronic expansion valve according to the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator includes: steps S310 to S340.

[0049] Step S310, calculating the superheat of the upper part of the liquid separator according to the temperature and pressure of the upper part of the liquid separator. Specifically, the saturation temperature is determined according to the pressure of the upper part of the liquid separator, and the result of subtracting the saturation temperature from the temperature of the upper part of the liquid separator is the superheat of the upper part of the liquid separator.

[0050] Step S320, determining whether the superheat degree of the upper inner portion of the liquid distributor is equal to a preset third superheat degree.

[0051] Step S330: If the superheat of the upper inner portion of the liquid distributor is equal to a preset third superheat, the opening of the electronic expansion valve is controlled according to the superheat of the evaporator.

[0052] In some embodiments, in step S330, the specific process of controlling the opening of the electronic expansion valve according to the superheat of the evaporator includes: judging the relationship between the superheat of the evaporator and a preset second superheat; if the superheat of the evaporator is less than or equal to the preset second superheat, reducing the opening of the electronic expansion valve; if the superheat of the evaporator is greater than the preset second superheat, maintaining the opening of the electronic expansion valve unchanged, and then re-determining whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator.

[0053] After the liquid refrigerant in the liquid distributor reaches the maximum amount, in order to prevent the compressor from being compressed with liquid, the refrigerant needs to be completely evaporated in the evaporator. Therefore, when the superheat of the evaporator is ≤0, the opening of the electronic expansion valve is reduced to reduce the refrigerant flow entering the evaporator and allow the refrigerant to completely evaporate in the evaporator. When the superheat of the evaporator is greater than 0, it is considered that the refrigerant has been completely evaporated in the evaporator, and the process of adjusting the liquid level of the liquid distributor is completed. After that, it is determined whether there is liquid refrigerant in the liquid distributor to determine whether to adjust the liquid level of the liquid refrigerant in the liquid distributor again.

[0054] Step S340: If the superheat degree of the upper inner portion of the liquid distributor is not equal to the preset third superheat degree, the opening degree of the electronic expansion valve is kept unchanged.

[0055] When the liquid refrigerant in the liquid distributor reaches the uppermost allowable end, the superheat of the upper part of the liquid distributor is 0, and the third superheat is preset to 0. Therefore, when the superheat of the upper part of the liquid distributor is not 0, it is considered that the liquid refrigerant in the liquid distributor has not been fully replenished. At this time, the electronic expansion valve is maintained at the current opening to continuously increase the liquid level of the liquid refrigerant in the liquid distributor; when the superheat of the upper part of the liquid distributor is 0, the liquid refrigerant in the liquid distributor reaches the maximum amount. At this time, the opening of the electronic expansion valve is reduced according to the superheat of the evaporator to restore the evaporator to the state before adjusting the liquid level in the liquid distributor.

[0056] Figure 4 The flow chart of the method for controlling the liquid level of the liquid distributor of the air conditioner of the present invention comprises:

[0057] Step 1: Detect the pressure P in the liquid distributor, the temperature T1 at the top, and the temperature T2 at the bottom, calculate the superheat Δ2 at the bottom based on P and T2, and determine whether Δ2>0. If Δ2>0, it means there is no liquid refrigerant at the bottom of the liquid distributor, and execute step 2; if Δ2≤0, execute step 1 again.

[0058] Step 2, adjust the opening of the air conditioner electronic expansion valve to make the superheat at the evaporator outlet 0, so that the refrigerant at the evaporator outlet is a gas-liquid mixture, and the gas-liquid mixed refrigerant is separated into gas and liquid in the liquid separator, so that part of the liquid refrigerant remains inside the liquid separator. Then calculate the superheat ΔT1 at the top of the liquid separator based on P and T1. When ΔT1 = 0, it is considered that the liquid level of the liquid separator has reached the uppermost end allowed by the liquid separator. At this time, adjust the opening of the electronic expansion valve to make the superheat at the evaporator outlet > 0, the system operates normally, and the superheated refrigerant from the evaporator exchanges heat with the liquid refrigerant in the liquid separator, improving the internal environment of the compressor and improving the system's energy efficiency.

[0059] By adopting the technical solution of this embodiment, during the operation of the air conditioner, whether the liquid separator contains liquid refrigerant is determined based on the pressure in the upper part of the liquid separator and the temperature at the bottom of the liquid separator; if the liquid separator does not contain liquid refrigerant, the opening of the air conditioner electronic expansion valve is controlled based on the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator, so as to ensure that there is always some liquid refrigerant in the liquid separator, reduce the suction temperature of the compressor, improve the operating environment inside the compressor, increase the mass flow rate of the refrigerant circulating in the system, and improve the energy efficiency of the system.

[0060] According to an embodiment of the present invention, a control device for an air conditioner corresponding to the control method for an air conditioner is also provided. The air conditioner comprises a compressor, an electronic expansion valve, and an evaporator; a liquid distributor is provided at the compressor. Figure 3 As shown, a liquid separator 6 is provided at the air inlet of the compressor 1. When the air conditioner is running, the high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the liquid separator 6 after passing through the condenser 2, the liquid reservoir 3, the electronic expansion valve 4, and the evaporator 5 in sequence. In the liquid separator 6, the liquid refrigerant is separated from the gaseous refrigerant. The liquid refrigerant is in the lower part of the liquid separator, and the gaseous refrigerant is in the upper part of the liquid separator. Then the gaseous refrigerant enters the compressor 1 for compression. If there is no liquid refrigerant in the liquid separator, the gaseous refrigerant from the evaporator cannot be heat exchanged to cool down, thereby increasing the suction and exhaust temperature, increasing the specific volume of the refrigerant, reducing the amount of refrigerant circulating in the system, and reducing the system energy efficiency. Therefore, in order to maintain stable and efficient operation of the air conditioner, it is necessary to ensure that the liquid separator contains a certain amount of liquid refrigerant.

[0061] See also Figure 2 The schematic diagram of the structure of an embodiment of the device of the present invention is shown. The control device of the air conditioner may include: an acquisition unit 102 and a control unit 104.

[0062] The acquisition unit 102 is configured to acquire the temperature and pressure of the upper part of the liquid separator, the temperature of the bottom of the liquid separator, and the superheat of the evaporator. The specific functions and processing of the acquisition unit 102 refer to step S110.

[0063] The liquid distributor is equipped with a temperature sensor and a pressure sensor. The sensor for detecting the upper temperature is set at the same level as the steel pipe inlet of the liquid distributor, and the sensor for detecting the bottom temperature is set at the lowest position of the lower cylinder of the liquid distributor. In the liquid distributor, the temperature and pressure of the upper part can be regarded as the temperature and pressure of the gaseous refrigerant, and the temperature of the bottom can be regarded as the temperature of the liquid refrigerant. If the liquid distributor does not contain liquid refrigerant, but only gaseous refrigerant, the pressure of the upper part and the bottom are the same.

[0064] The superheat of the evaporator can be calculated by detecting the pressure and temperature at the outlet of the evaporator. Specifically, according to the pressure at the outlet of the evaporator, the pressure-temperature comparison table is searched to determine the saturation temperature corresponding to the pressure. The result of subtracting the saturation temperature from the outlet temperature of the evaporator is the superheat of the evaporator.

[0065] The control unit 104 is configured to determine whether the liquid separator contains liquid refrigerant according to the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator. The specific functions and processing of the control unit 104 refer to step S120.

[0066] The superheat at the bottom can be calculated based on the pressure at the top of the liquid distributor and the temperature at the bottom. The calculation method is the same as that of the evaporator superheat. The superheat at the bottom of the liquid distributor can be used to determine whether the refrigerant at the bottom is completely evaporated, thereby determining whether there is liquid refrigerant in the liquid distributor.

[0067] In some embodiments, the control unit 104 determines the specific process of whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator, including: calculating the superheat of the bottom part of the liquid separator based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator, specifically determining the saturation temperature based on the pressure in the upper part of the liquid separator, and the result of subtracting the saturation temperature from the temperature in the bottom part of the liquid separator is the superheat of the bottom part of the liquid separator; judging whether the superheat of the bottom part of the liquid separator is greater than a preset first superheat; if the superheat of the bottom part of the liquid separator is greater than the preset first superheat, determining that the liquid separator does not contain liquid refrigerant; if the superheat of the bottom part of the liquid separator is less than or equal to the preset first superheat, determining that the liquid separator contains liquid refrigerant.

[0068] The refrigerant at the top of the liquid separator is in gaseous state, and the corresponding saturation temperature is high. If the temperature at the bottom of the liquid separator is greater than the saturation temperature, it means that the refrigerant at the bottom is already in a saturated state, and there is no liquid refrigerant. At this time, the superheat at the bottom is greater than 0, and the first superheat is preset to 0. Therefore, when the superheat at the bottom of the liquid separator is greater than 0, it is considered that there is no liquid refrigerant in the liquid separator; when the superheat at the bottom of the liquid separator is ≤0, it is considered that there is liquid refrigerant in the liquid separator.

[0069] If the liquid distributor does not contain liquid refrigerant, the liquid level in the liquid distributor is 0. Therefore, the liquid level in the liquid distributor may be detected by setting a liquid level sensor, and whether the liquid distributor contains liquid refrigerant may be determined based on the liquid level.

[0070] The control unit 104 is further configured to control the opening of the electronic expansion valve according to the temperature and pressure of the upper part of the liquid separator and the superheat of the evaporator if it is determined that the liquid separator does not contain liquid refrigerant. The specific functions and processing of the control unit 104 refer to step S130.

[0071] If there is no liquid refrigerant in the liquid distributor, it means that the refrigerant superheat is too high. It is necessary to reduce the compressor suction superheat as much as possible while ensuring that the compressor suction does not carry liquid, so as to increase the actual circulating refrigerant amount of the compressor. By controlling the opening of the electronic expansion valve, the evaporation degree of the refrigerant in the evaporator can be adjusted, thereby reducing the superheat and generating a certain amount of liquid refrigerant in the liquid distributor. If there is liquid refrigerant in the liquid distributor, the air conditioner is operating normally.

[0072] By controlling the liquid level of the liquid refrigerant in the liquid distributor, it is ensured that there is always some liquid refrigerant in the liquid distributor. When the gaseous refrigerant from the evaporator passes through the liquid distributor, it exchanges heat with the refrigerant in the liquid distributor, thereby reducing the temperature of the refrigerant at the suction port of the compressor pump and increasing the mass flow rate per unit displacement. When the compressor displacement remains unchanged, the mass flow rate of the refrigerant circulating in the system is increased, thereby increasing the cooling capacity of the system. In addition, since the temperature of the suction port of the compressor pump is reduced, the operating environment inside the compressor can be improved, the exhaust temperature of the compressor is reduced, and the energy efficiency of the compressor can be improved.

[0073] In some embodiments, the control unit 104 controls the opening of the electronic expansion valve according to the temperature and pressure of the upper part of the liquid distributor and the superheat of the evaporator, including:

[0074] The control unit 104 is further configured to determine the magnitude relationship between the superheat of the evaporator and a preset second superheat. The specific functions and processing of the control unit 104 refer to step S210.

[0075] The control unit 104 is further configured to increase the opening of the electronic expansion valve if the superheat of the evaporator is greater than a preset second superheat. The specific functions and processing of the control unit 104 refer to step S220.

[0076] The control unit 104 is further configured to control the opening of the electronic expansion valve according to the temperature and pressure of the upper part of the liquid distributor and the superheat of the evaporator if the superheat of the evaporator is less than or equal to the preset second superheat. The specific functions and processing of the control unit 104 refer to step S230.

[0077] In order to increase the amount of liquid refrigerant in the liquid separator, it is necessary to make the refrigerant incompletely evaporate in the evaporator, so that the refrigerant flowing out of the evaporator is in a gas-liquid mixed state, and then the gas-liquid separation is carried out in the liquid separator, and the liquid refrigerant remains in the liquid separator.

[0078] In order to prevent the refrigerant from completely evaporating in the evaporator, the superheat of the evaporator needs to be reduced. At this time, the opening of the electronic expansion valve is increased to increase the refrigerant flow rate into the evaporator, so that the refrigerant evaporates incompletely. The second superheat is preset to 0.

[0079] When the refrigerant does not completely evaporate in the evaporator, liquid refrigerant begins to be produced in the liquid separator. At this time, continue to detect the temperature and pressure in the upper part of the liquid separator to determine whether the liquid refrigerant in the liquid separator has reached the maximum amount. After the liquid refrigerant reaches the maximum amount, control the opening of the electronic expansion valve according to the superheat of the evaporator to restore the evaporator to the state before adjusting the liquid level in the liquid separator.

[0080] In some embodiments, the control unit 104 controls the opening of the electronic expansion valve according to the temperature and pressure of the upper part of the liquid distributor and the superheat of the evaporator, including:

[0081] The control unit 104 is further configured to calculate the superheat of the upper part of the liquid separator according to the temperature and pressure of the upper part of the liquid separator. Specifically, the saturation temperature is determined according to the pressure of the upper part of the liquid separator, and the result of subtracting the saturation temperature from the temperature of the upper part of the liquid separator is the superheat of the upper part of the liquid separator. The specific functions and processing of the control unit 104 refer to step S310.

[0082] The control unit 104 is further configured to determine whether the superheat of the upper portion of the liquid distributor is equal to a preset third superheat. The specific functions and processing of the control unit 104 refer to step S320.

[0083] The control unit 104 is further configured to control the opening of the electronic expansion valve according to the superheat of the evaporator if the superheat of the upper part of the liquid distributor is equal to the preset third superheat. The specific functions and processing of the control unit 104 refer to step S330.

[0084] In some embodiments, the control unit 104 controls the opening of the electronic expansion valve according to the superheat of the evaporator, and the specific process includes: judging the relationship between the superheat of the evaporator and a preset second superheat; if the superheat of the evaporator is less than or equal to the preset second superheat, reducing the opening of the electronic expansion valve; if the superheat of the evaporator is greater than the preset second superheat, maintaining the opening of the electronic expansion valve unchanged, and then re-determining whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator.

[0085] After the liquid refrigerant in the liquid distributor reaches the maximum amount, in order to prevent the compressor from being compressed with liquid, the refrigerant needs to be completely evaporated in the evaporator. Therefore, when the superheat of the evaporator is ≤0, the opening of the electronic expansion valve is reduced to reduce the refrigerant flow entering the evaporator and allow the refrigerant to completely evaporate in the evaporator. When the superheat of the evaporator is greater than 0, it is considered that the refrigerant has been completely evaporated in the evaporator, and the process of adjusting the liquid level of the liquid distributor is completed. After that, it is determined whether there is liquid refrigerant in the liquid distributor to determine whether to adjust the liquid level of the liquid refrigerant in the liquid distributor again.

[0086] The control unit 104 is further configured to keep the opening of the electronic expansion valve unchanged if the superheat of the upper portion of the liquid distributor is not equal to the preset third superheat. The specific functions and processing of the control unit 104 refer to step S340.

[0087] When the liquid refrigerant in the liquid distributor reaches the uppermost allowable end, the superheat of the upper part of the liquid distributor is 0, and the third superheat is preset to 0. Therefore, when the superheat of the upper part of the liquid distributor is not 0, it is considered that the liquid refrigerant in the liquid distributor has not been fully replenished. At this time, the electronic expansion valve is maintained at the current opening to continuously increase the liquid level of the liquid refrigerant in the liquid distributor; when the superheat of the upper part of the liquid distributor is 0, the liquid refrigerant in the liquid distributor reaches the maximum amount. At this time, the opening of the electronic expansion valve is reduced according to the superheat of the evaporator to restore the evaporator to the state before adjusting the liquid level in the liquid distributor.

[0088] Figure 4 The flow chart of the method for controlling the liquid level of the liquid distributor of the air conditioner of the present invention comprises:

[0089] Step 1: Detect the pressure P in the liquid distributor, the temperature T1 at the top, and the temperature T2 at the bottom, calculate the superheat Δ2 at the bottom based on P and T2, and determine whether Δ2>0. If Δ2>0, it means there is no liquid refrigerant at the bottom of the liquid distributor, and execute step 2; if Δ2≤0, execute step 1 again.

[0090] Step 2, adjust the opening of the air conditioner electronic expansion valve to make the superheat at the evaporator outlet 0, so that the refrigerant at the evaporator outlet is a gas-liquid mixture, and the gas-liquid mixed refrigerant is separated into gas and liquid in the liquid separator, so that part of the liquid refrigerant remains inside the liquid separator. Then calculate the superheat ΔT1 at the top of the liquid separator based on P and T1. When ΔT1 = 0, it is considered that the liquid level of the liquid separator has reached the uppermost end allowed by the liquid separator. At this time, adjust the opening of the electronic expansion valve to make the superheat at the evaporator outlet > 0, the system operates normally, and the superheated refrigerant from the evaporator exchanges heat with the liquid refrigerant in the liquid separator, improving the internal environment of the compressor and improving the system's energy efficiency.

[0091] Since the processing and functions implemented by the device of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned method, for the details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be made here.

[0092] By adopting the technical solution of the present invention, during the operation of the air conditioner, it is determined whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom of the liquid separator; if the liquid separator does not contain liquid refrigerant, the opening of the air conditioner electronic expansion valve is controlled based on the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator, thereby ensuring that some liquid refrigerant is always present in the liquid separator, reducing the suction temperature of the compressor, improving the operating environment inside the compressor, increasing the mass flow rate of the refrigerant circulating in the system, and improving the energy efficiency of the system.

[0093] According to an embodiment of the present invention, an air conditioner corresponding to the control device of the air conditioner is also provided. The air conditioner may include: the control device of the air conditioner described above.

[0094] Since the processing and functions implemented by the air conditioner of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned devices, for the details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0095] By adopting the technical solution of the present invention, during the operation of the air conditioner, it is determined whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom of the liquid separator; if the liquid separator does not contain liquid refrigerant, the opening of the air conditioner electronic expansion valve is controlled based on the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator, thereby ensuring that some liquid refrigerant is always present in the liquid separator, reducing the suction temperature of the compressor, improving the operating environment inside the compressor, increasing the mass flow rate of the refrigerant circulating in the system, and improving the energy efficiency of the system.

[0096] According to an embodiment of the present invention, a storage medium corresponding to the air conditioner control method is also provided, wherein the storage medium includes a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute the air conditioner control method described above.

[0097] Since the processing and functions implemented by the storage medium of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned method, for the details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be made here.

[0098] By adopting the technical solution of the present invention, during the operation of the air conditioner, it is determined whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom of the liquid separator; if the liquid separator does not contain liquid refrigerant, the opening of the air conditioner electronic expansion valve is controlled based on the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator, thereby ensuring that some liquid refrigerant is always present in the liquid separator, reducing the suction temperature of the compressor, improving the operating environment inside the compressor, increasing the mass flow rate of the refrigerant circulating in the system, and improving the energy efficiency of the system.

[0099] According to an embodiment of the present invention, a computer program product corresponding to the air conditioner control method is also provided, wherein the computer program product comprises a computer program, and when the computer program product is processed and executed, the steps of the air conditioner control method are implemented.

[0100] Since the processing and functions implemented by the computer program product of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned method, for the details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0101] By adopting the technical solution of the present invention, during the operation of the air conditioner, it is determined whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom of the liquid separator; if the liquid separator does not contain liquid refrigerant, the opening of the air conditioner electronic expansion valve is controlled based on the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator, thereby ensuring that some liquid refrigerant is always present in the liquid separator, reducing the suction temperature of the compressor, improving the operating environment inside the compressor, increasing the mass flow rate of the refrigerant circulating in the system, and improving the energy efficiency of the system.

[0102] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0103] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A method for controlling an air conditioner, characterized in that: The air conditioner includes a compressor, an electronic expansion valve, and an evaporator; The compressor is provided with a liquid distributor; The method comprises: Obtaining the temperature and pressure of the upper part of the liquid separator, the temperature of the bottom of the liquid separator, and the superheat of the evaporator; Determining whether the liquid separator contains liquid refrigerant according to the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator; If it is determined that the liquid separator does not contain liquid refrigerant, the opening of the electronic expansion valve is controlled according to the temperature and pressure of the upper part of the liquid separator and the superheat of the evaporator.

2. The air conditioner control method according to claim 1, characterized in that: Determining whether the liquid separator contains liquid refrigerant according to the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator includes: Calculating the superheat of the bottom of the liquid separator according to the pressure of the upper part of the liquid separator and the temperature of the bottom of the liquid separator; Determining whether the superheat degree of the bottom of the liquid distributor is greater than a preset first superheat degree; If the superheat degree at the bottom of the liquid separator is greater than a preset first superheat degree, it is determined that the liquid separator does not contain liquid refrigerant; If the superheat degree at the bottom of the liquid separator is less than or equal to a preset first superheat degree, it is determined that liquid refrigerant is contained in the liquid separator.

3. The air conditioner control method according to claim 1 or 2, characterized in that: According to the temperature and pressure of the upper part of the liquid distributor and the superheat of the evaporator, the opening of the electronic expansion valve is controlled, including: Determining the magnitude relationship between the superheat of the evaporator and a preset second superheat; If the superheat of the evaporator is greater than a preset second superheat, increasing the opening of the electronic expansion valve; If the superheat of the evaporator is less than or equal to a preset second superheat, the opening of the electronic expansion valve is controlled according to the temperature and pressure of the upper part of the liquid distributor and the superheat of the evaporator.

4. The air conditioner control method according to claim 3, characterized in that: Controlling the opening of the electronic expansion valve according to the temperature and pressure of the upper part of the liquid distributor and the superheat of the evaporator, comprising: Calculating the superheat of the upper part of the liquid separator according to the temperature and pressure of the upper part of the liquid separator; Determining whether the superheat degree of the upper inner portion of the liquid distributor is equal to a preset third superheat degree; If the superheat of the upper part of the liquid distributor is equal to the preset third superheat, the opening of the electronic expansion valve is controlled according to the superheat of the evaporator; If the superheat degree of the upper inner portion of the liquid distributor is not equal to the preset third superheat degree, the opening degree of the electronic expansion valve is kept unchanged.

5. The air conditioner control method according to claim 4, characterized in that: Controlling the opening of the electronic expansion valve according to the superheat of the evaporator includes: Determining the magnitude relationship between the superheat of the evaporator and a preset second superheat; If the superheat of the evaporator is less than or equal to a preset second superheat, reducing the opening of the electronic expansion valve; If the superheat of the evaporator is greater than the preset second superheat, the opening of the electronic expansion valve is kept unchanged, and then it is determined whether the liquid separator contains liquid refrigerant based on the pressure in the upper part of the liquid separator and the temperature in the bottom of the liquid separator.

6. A control device for an air conditioner, characterized in that: The air conditioner includes a compressor, an electronic expansion valve, and an evaporator; The compressor is provided with a liquid distributor; The device comprises: an acquisition unit configured to acquire the temperature and pressure of the upper portion of the liquid separator, the temperature of the bottom portion of the liquid separator, and the superheat of the evaporator; a control unit configured to determine whether the liquid separator contains liquid refrigerant according to the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator; The control unit is further configured to control the opening of the electronic expansion valve according to the temperature and pressure in the upper part of the liquid separator and the superheat of the evaporator if it is determined that the liquid separator does not contain liquid refrigerant.

7. The air conditioner control device according to claim 6, characterized in that: The control unit determines whether the liquid separator contains liquid refrigerant according to the pressure in the upper part of the liquid separator and the temperature in the bottom part of the liquid separator, including: Calculating the superheat of the bottom of the liquid separator according to the pressure of the upper part of the liquid separator and the temperature of the bottom of the liquid separator; Determining whether the superheat degree of the bottom of the liquid distributor is greater than a preset first superheat degree; If the superheat degree at the bottom of the liquid separator is greater than a preset first superheat degree, it is determined that the liquid separator does not contain liquid refrigerant; If the superheat degree at the bottom of the liquid separator is less than or equal to a preset first superheat degree, it is determined that liquid refrigerant is contained in the liquid separator.

8. An air conditioner, characterized in that: include: The air conditioner control device as claimed in claim 6 or 7.

9. A storage medium, characterized in that: The storage medium includes a stored program, wherein when the program is executed, the device where the storage medium is located is controlled to execute the air conditioner control method according to any one of claims 1 to 5.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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