Method for adjusting supercooling degree of outdoor unit, control device and air conditioner

Abstract

The application provides an outdoor unit supercooling degree adjusting method, a control device and an air conditioner, and relates to the technical field of air conditioners. The outdoor unit supercooling degree adjusting method is applied to an air conditioner. A main refrigerant path between an outdoor unit and an indoor unit of the air conditioner is connected in parallel with a supercooling auxiliary path. The supercooling auxiliary path passes through a liquid refrigerant area of a gas-liquid separator in the air conditioner. An auxiliary electronic expansion valve is arranged in the supercooling auxiliary path. The method comprises the following steps: obtaining a current outdoor unit supercooling degree; and adjusting the opening degree of the auxiliary electronic expansion valve according to the current outdoor unit supercooling degree. In the outdoor unit supercooling degree adjusting method, the low-temperature refrigerant at the lower part of the gas-liquid separator is utilized by arranging the supercooling auxiliary path. The opening degree of the auxiliary electronic expansion valve of the supercooling auxiliary path is adjusted according to the deficiency of the current outdoor unit supercooling degree. The compensation effect of the refrigerant in the supercooling auxiliary path on the outdoor unit and system supercooling degree is adjusted correspondingly. Therefore, the outdoor unit and system supercooling degree can meet the requirements, the cooling performance of the air conditioner on the indoor environment is ensured, and the user experience is improved.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically, to a method, control device, and air conditioner for adjusting the subcooling of an outdoor unit. Background Technology

[0002] When a multi-split air conditioner is in cooling mode, the main electronic expansion valve located outdoors is usually adjusted to its maximum opening. The air conditioner mainly uses the indoor unit's electronic expansion valve for throttling to reduce pressure loss caused by the long connecting pipes, thereby ensuring the flow of refrigerant through the indoor unit and the cooling effect of the indoor unit. However, when the main electronic expansion valve is kept at its maximum opening, the throttling effect is small and it cannot adjust the subcooling of the outdoor unit. Insufficient subcooling of the outdoor unit will reduce the cooling performance of the air conditioner and affect the user experience. Summary of the Invention

[0003] The purpose of this invention is to provide a method, control device, and air conditioner for adjusting the subcooling of an outdoor unit, so as to solve the technical problem that insufficient subcooling of the outdoor unit in existing air conditioners will lead to a decrease in the cooling performance of the air conditioner and affect the user experience.

[0004] To address the aforementioned problems, this invention provides a method for adjusting the subcooling degree of an outdoor unit, applied to an air conditioner. The air conditioner's main refrigerant circuit between the outdoor and indoor units is connected in parallel with a subcooling auxiliary circuit. This subcooling auxiliary circuit passes through the liquid refrigerant region of the gas-liquid separator in the air conditioner, and is equipped with an auxiliary electronic expansion valve. The method includes: acquiring the current subcooling degree of the outdoor unit; and adjusting the opening degree of the auxiliary electronic expansion valve based on the current subcooling degree of the outdoor unit.

[0005] The outdoor unit subcooling adjustment method provided by this invention utilizes the low-temperature refrigerant in the lower part of the gas-liquid separator by setting up a subcooling auxiliary circuit. The opening of the auxiliary electronic expansion valve of the subcooling auxiliary circuit is adjusted according to the degree of insufficiency of the current outdoor unit subcooling, thereby adjusting the compensation effect of the refrigerant in the subcooling auxiliary circuit on the subcooling of the outdoor unit and the system. This ensures that the subcooling of the outdoor unit and the system meets the requirements, guarantees the cooling performance of the air conditioner for the indoor environment, and improves the user experience.

[0006] Optionally, the step of adjusting the opening of the auxiliary electronic expansion valve according to the current subcooling degree of the outdoor unit includes: determining whether the current subcooling degree of the outdoor unit is less than the target lower threshold of the target threshold range; if so, controlling the air conditioner to enter the auxiliary valve opening adjustment mode, in which the auxiliary electronic expansion valve is opened and its opening is adjusted so that the current subcooling degree of the outdoor unit is within the target threshold range. When the current subcooling degree of the outdoor unit is less than the target lower threshold of the target threshold range, it is determined that subcooling compensation of the subcooling auxiliary circuit is required, thereby controlling the air conditioner to enter the auxiliary valve opening adjustment mode, opening the auxiliary electronic expansion valve and adjusting it to a suitable opening according to the degree of deficiency of the current subcooling degree of the outdoor unit, so that the refrigerant flow of the corresponding flow is subcooled by the low-temperature refrigerant in the gas-liquid separator during the process of passing through the subcooling auxiliary circuit, thereby compensating for the degree of subcooling of the air conditioner. Under the subcooling compensation of the subcooling auxiliary circuit, the current subcooling degree of the outdoor unit gradually increases to reach the target threshold range, and the cooling performance of the air conditioner meets the requirements, enabling efficient cooling of the indoor environment.

[0007] Optionally, in the auxiliary valve opening adjustment mode, the opening of the auxiliary electronic expansion valve is adjusted so that the current outdoor unit subcooling gradually approaches the target outdoor unit subcooling within the target threshold range. After the air conditioner enters the auxiliary valve opening adjustment mode, the opening of the auxiliary electronic expansion valve can be adjusted so that the current outdoor unit subcooling dynamically stabilizes near the target outdoor unit subcooling, thereby keeping the air conditioner in optimal cooling condition.

[0008] Optionally, the step of adjusting the opening of the auxiliary electronic expansion valve according to the current outdoor unit subcooling degree further includes: determining whether the initially acquired current outdoor unit subcooling degree is greater than or equal to the target lower threshold and less than or equal to the target upper threshold of the target threshold range; if so, controlling the air conditioner to enter the auxiliary valve opening adjustment mode. The air conditioner adjusts the valve during its first cycle of operation to gradually bring the current outdoor unit subcooling degree closer to and eventually dynamically stabilize it near the target outdoor unit subcooling degree, thereby maintaining the air conditioner in optimal cooling condition.

[0009] Optionally, the step of adjusting the opening of the auxiliary electronic expansion valve according to the current subcooling degree of the outdoor unit includes: determining whether the current subcooling degree of the outdoor unit is greater than the target upper limit threshold of the target threshold range; if so, controlling the auxiliary electronic expansion valve to be in the closed state. When the current subcooling degree of the outdoor unit is greater than the target upper limit threshold, it indicates that the subcooling degree of the outdoor unit has exceeded the requirements, and correspondingly, the air conditioner has high cooling performance, and there is no need for subcooling auxiliary circuit to compensate for subcooling, thereby controlling the auxiliary electronic expansion valve to be in the closed state and the subcooling auxiliary circuit to be in the closed-loop state.

[0010] Optionally, in the auxiliary valve opening adjustment mode, the step of opening the auxiliary electronic expansion valve and adjusting its opening to make the current outdoor unit subcooling within the target threshold range includes: obtaining the current compensated subcooling of the subcooling auxiliary circuit every preset time period as a cycle; determining the target opening of the auxiliary electronic expansion valve for the next cycle based on the current outdoor unit subcooling, the target lower limit threshold, and the current compensated subcooling; and adjusting the auxiliary electronic expansion valve for the next cycle to the target opening.

[0011] Optionally, the step of determining the target opening degree of the auxiliary electronic expansion valve for the next cycle based on the current outdoor unit subcooling, the target lower limit threshold, and the current compensated subcooling includes: calculating the target opening degree of the auxiliary electronic expansion valve for the next cycle according to the opening degree adjustment formula, wherein the opening degree adjustment formula is: P k+1 =P k +△P; where P k+1 P is the target opening degree of the auxiliary electronic expansion valve in the next cycle. k The current opening degree of the auxiliary electronic expansion valve in the current cycle is given by ΔP, where ΔP is the opening adjustment value of the auxiliary electronic expansion valve; the opening adjustment value is calculated according to the following formula: ΔP = (SC2) 目标 -SC2 当前 )*S1*S2; where, SC2 目标 The target compensation subcooling degree for the subcooling auxiliary circuit is the difference between the target lower limit threshold and the current subcooling degree of the outdoor unit; SC2 当前 S1 is the current compensation subcooling degree of the subcooling auxiliary circuit, S2 is the suction temperature correction coefficient of the compressor in the air conditioner, and S3 is the oil temperature correction coefficient of the compressor.

[0012] Optionally, the method further includes: if the intake temperature is less than or equal to the lower limit of the intake temperature threshold range, the intake temperature correction coefficient is 0.5m; if the intake temperature is greater than the lower limit of the intake temperature threshold range but less than the upper limit of the intake temperature threshold range, the intake temperature correction coefficient is m; if the intake temperature is greater than the upper limit of the intake temperature threshold range, the intake temperature correction coefficient is 2m; where m is the base value of the intake temperature correction coefficient. The opening adjustment of the auxiliary electronic expansion valve is corrected by the value of the intake temperature correction coefficient to improve the accuracy of the adjustment of the outdoor unit and system subcooling.

[0013] Optionally, the method further includes: if the oil temperature is less than or equal to the lower limit threshold of the oil temperature threshold range, the oil temperature correction coefficient is 0.5n; if the oil temperature is greater than the lower limit threshold and less than the upper limit threshold of the oil temperature threshold range, the oil temperature correction coefficient is n; if the oil temperature is greater than the upper limit threshold, the oil temperature correction coefficient is 2n; where n is the base value of the oil temperature correction coefficient. The opening adjustment of the auxiliary electronic expansion valve is corrected by the value of the oil temperature correction coefficient to improve the accuracy of adjusting the subcooling of the outdoor unit and the system.

[0014] Optionally, when the air conditioner enters the auxiliary valve opening adjustment mode, it controls the auxiliary electronic expansion valve to open and adjusts its opening to a preset opening. The preset opening is the average opening of the indoor unit's electronic expansion valves. The preset opening is the average opening of multiple indoor unit electronic expansion valves, enabling rapid and accurate initial opening adjustment of the auxiliary electronic expansion valve. This allows the subcooling auxiliary circuit to quickly enter the compensation stage, correspondingly reducing the occurrence of situations where the auxiliary electronic expansion valve starts adjusting from 0 pls, resulting in long adjustment time, poor adjustment effect, and poor subcooling effect.

[0015] This invention also provides a control device, comprising: an acquisition module for acquiring the current subcooling degree of the outdoor unit; and a control module for adjusting the opening of an auxiliary electronic expansion valve according to the current subcooling degree of the outdoor unit. The outdoor unit and indoor unit of the air conditioner have a main refrigerant circuit connected in parallel to a subcooling auxiliary circuit, which passes through the liquid refrigerant region of the gas-liquid separator in the air conditioner. The auxiliary electronic expansion valve is located in the subcooling auxiliary circuit. This control device can adjust the opening of the auxiliary electronic expansion valve in the subcooling auxiliary circuit according to the degree of insufficiency of the current subcooling degree of the outdoor unit, thereby adjusting the compensation effect of the refrigerant in the subcooling auxiliary circuit on the subcooling degree of the outdoor unit and the system. This ensures that the subcooling degree of the outdoor unit and the system meets the requirements, guaranteeing the cooling performance of the air conditioner for the indoor environment and improving the user experience.

[0016] The present invention also provides an air conditioner, including a computer-readable storage medium storing a computer program and a controller, wherein the computer program is read and executed by the controller to implement the above-described method for adjusting the subcooling of the outdoor unit.

[0017] The present invention also provides a computer-readable storage medium storing a computer program, which is read and executed by a controller to implement the above-described method for adjusting the subcooling of the outdoor unit. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the first method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic flowchart of a second method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention;

[0021] Figure 3 This is a flowchart illustrating the third method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention.

[0022] Figure 4 This is a partial flowchart illustrating the fourth method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention.

[0023] Figure 5 This is a partial flowchart illustrating the fifth method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention.

[0024] Figure 6 A schematic diagram of the control device provided in an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of one type of air conditioner provided in an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100-Compressor; 200-Oil separator; 300-Four-way valve; 400-Outdoor unit; 500-Gas-liquid separator; 610-Main refrigerant circuit; 620-Main circuit electronic expansion valve; 630-Filter; 640-Gas pipe shut-off valve; 650-Low pressure switch; 710-Subcooling auxiliary circuit; 720-Auxiliary electronic expansion valve; 61-Acquisition module; 62-Control module. Detailed Implementation

[0028] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0029] This embodiment provides a method, control device, and air conditioner for adjusting the subcooling of an outdoor unit, such as... Figure 1-7 As shown. Among them, Figure 7 This is a system schematic diagram of an air conditioner provided in an embodiment of the present invention. Figure 7 The air conditioner shown can perform the above-mentioned outdoor unit subcooling adjustment method. Specifically, the air conditioner includes a compressor 100, an oil separator 200, a four-way valve 300, an outdoor unit 400, an indoor unit (not shown in the figure), and a gas-liquid separator 500 connected in a closed loop. A main circuit electronic expansion valve 620 is installed on the refrigerant main circuit 610 between the outdoor unit 400 and the indoor unit to control the refrigerant flow rate in the main circuit 610. A subcooling auxiliary circuit is also connected in parallel to the main circuit 610 between the outdoor unit 400 and the indoor unit. 710, the subcooling auxiliary circuit 710 passes through the liquid refrigerant area below the gas-liquid separator 500. The subcooling auxiliary circuit 710 is equipped with an auxiliary electronic expansion valve 720, which is used to regulate the refrigerant flow of the subcooling auxiliary circuit 710. In addition, the pipeline is also equipped with a filter 630, a gas pipe shut-off valve 640, a low-pressure switch 650, etc. as needed. When the pipeline between the outdoor unit 400 and the indoor unit is equipped with a filter 630, the subcooling auxiliary circuit 710 is connected in parallel to the pipeline between the outdoor unit 400 and the filter 630.

[0030] Figure 1 This is a schematic flowchart of a first method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention. Figure 1 The method for adjusting the subcooling of the outdoor unit, as shown, includes:

[0031] The air conditioner is turned on and running stably.

[0032] S102 obtains the current subcooling level of the outdoor unit.

[0033] S104 adjusts the opening of the auxiliary electronic expansion valve 720 according to the current subcooling of the outdoor unit.

[0034] Among them, the refrigerant main circuit 610 between the outdoor unit 400 and the indoor unit of the air conditioner is connected in parallel with the subcooling auxiliary circuit 710. The subcooling auxiliary circuit 710 passes through the liquid refrigerant area of ​​the gas-liquid separator 500 in the air conditioner, and the auxiliary electronic expansion valve 720 is located in the subcooling auxiliary circuit 710.

[0035] During the operation of the air conditioner, the current subcooling degree of the outdoor unit is obtained. When the current subcooling degree of the outdoor unit meets the requirements, it indicates that the air conditioner has better cooling performance and there is no need for the subcooling auxiliary circuit to compensate for the subcooling degree of the outdoor unit. At this time, the opening degree of the control auxiliary electronic expansion valve is 0pls, that is, the subcooling auxiliary circuit is in a closed state. When the outdoor unit's subcooling is insufficient, it indicates poor cooling performance of the air conditioner. The subcooling auxiliary circuit is needed to compensate for the subcooling of the outdoor unit, thus improving the overall subcooling of the system. At this time, the auxiliary electronic expansion valve is opened, and the refrigerant flowing from the outdoor unit's circuit is split between the subcooling auxiliary circuit and the main refrigerant circuit. Part of the refrigerant flows into the main refrigerant circuit, and the other part flows into the subcooling auxiliary circuit. When the refrigerant in the subcooling auxiliary circuit passes through the liquid refrigerant area of ​​the gas-liquid separator, it is subcooled by the low-temperature liquid refrigerant and lubricating oil mixture in that area. The subcooled refrigerant then flows back into the main refrigerant circuit to mix with the existing refrigerant, thereby increasing the subcooling of the outdoor unit and the air conditioner, and consequently improving the air conditioner's cooling performance. The mixed refrigerant with higher subcooling then flows into the indoor unit to efficiently cool the indoor environment, thus improving the user experience.

[0036] When subcooling compensation is needed, the auxiliary electronic expansion valve is opened while its opening degree is adjusted according to the current degree of subcooling deficiency of the outdoor unit. By adjusting the refrigerant flow in the subcooling auxiliary circuit, the degree of subcooling compensation of the subcooling auxiliary circuit is adjusted, thereby ensuring that the subcooling of the air conditioner system meets the requirements and enables it to have high cooling performance. Specifically, the opening degree of the auxiliary electronic expansion valve is positively correlated with the current degree of subcooling deficiency of the outdoor unit. That is, when the current subcooling of the outdoor unit is low, the auxiliary electronic expansion valve is adjusted to a larger opening degree, and the larger flow of refrigerant in the subcooling auxiliary circuit is subcooled by the low-temperature refrigerant in the lower area of ​​the gas-liquid separator, thereby improving its subcooling compensation for the outdoor unit and the system. When the current subcooling of the outdoor unit is high, the auxiliary electronic expansion valve is adjusted to a smaller opening degree, and the smaller flow of refrigerant in the subcooling auxiliary circuit is subcooled by the low-temperature refrigerant in the lower area of ​​the gas-liquid separator, thereby reducing its subcooling compensation for the system.

[0037] In this method for adjusting the subcooling of the outdoor unit, a subcooling auxiliary circuit is set up to utilize the low-temperature refrigerant at the bottom of the gas-liquid separator. The opening of the auxiliary electronic expansion valve in the subcooling auxiliary circuit is adjusted according to the degree of insufficiency of the current subcooling of the outdoor unit. This adjusts the compensation effect of the refrigerant in the subcooling auxiliary circuit on the subcooling of the outdoor unit and the system, thereby ensuring that the subcooling of the outdoor unit and the system meets the requirements, ensuring the cooling performance of the air conditioner for the indoor environment, and improving the user experience.

[0038] Specifically, the opening adjustment range of the auxiliary electronic expansion valve can be [0pls, 480pls].

[0039] Optionally, in this embodiment, step S104, which adjusts the opening of the auxiliary electronic expansion valve according to the current subcooling of the outdoor unit, includes: determining whether the current subcooling of the outdoor unit is less than the target lower limit threshold of the target threshold range; if so, controlling the air conditioner to enter the auxiliary valve opening adjustment mode. In the auxiliary valve opening adjustment mode, the auxiliary electronic expansion valve is opened and its opening is adjusted so that the current subcooling of the outdoor unit is within the target threshold range. Based on the operating environment of the air conditioner, a suitable target threshold range for the subcooling of the outdoor unit is set. During the operation of the air conditioner, when the current subcooling of the outdoor unit is less than the lower limit of the target threshold range, it indicates that the subcooling of the outdoor unit is too low, the cooling performance of the air conditioner is poor, and it cannot cool the indoor environment well. Accordingly, it is determined that subcooling compensation of the subcooling auxiliary circuit is needed, thereby controlling the air conditioner to enter the auxiliary valve opening adjustment mode, opening the auxiliary electronic expansion valve and adjusting it to a suitable opening according to the degree of deficiency of the current subcooling of the outdoor unit. This allows the corresponding flow of refrigerant to be subcooled by the low-temperature refrigerant in the gas-liquid separator as it passes through the subcooling auxiliary circuit, thus compensating for the degree of subcooling of the air conditioner. Under the subcooling compensation of the subcooling auxiliary circuit, the current subcooling of the outdoor unit gradually increases to reach the target threshold range, and the cooling performance of the air conditioner meets the requirements, enabling efficient cooling of the indoor environment.

[0040] Specifically, in this embodiment, under the auxiliary valve opening adjustment mode, the opening of the auxiliary electronic expansion valve is adjusted so that the current outdoor unit subcooling gradually approaches the target outdoor unit subcooling within the target threshold range. The target outdoor unit subcooling is set within the target threshold range. When the current outdoor unit subcooling reaches the target outdoor unit subcooling, it indicates that the outdoor unit subcooling is at its optimal value, and the air conditioner is correspondingly at its optimal cooling effect. When the current subcooling of the outdoor unit is less than the target lower threshold, the air conditioner is controlled to enter the auxiliary valve opening adjustment mode. This opens the auxiliary electrical expansion valve and adjusts its opening. The refrigerant in the subcooling auxiliary circuit compensates for the subcooling of the outdoor unit, bringing the current subcooling of the outdoor unit into the target threshold range and gradually approaching the target subcooling. Accordingly, the air conditioner is adjusted to gradually reach the optimal cooling effect. Specifically, after entering the auxiliary valve opening adjustment mode, the air conditioner can continuously adjust the opening of the auxiliary electronic expansion valve to keep the current subcooling of the outdoor unit dynamically stable near the target subcooling, thus maintaining the optimal cooling state. Alternatively, the air conditioner can be controlled to exit the auxiliary valve opening adjustment mode and continuously or periodically monitor the current subcooling of the outdoor unit. When the current subcooling of the outdoor unit is less than the target lower threshold, the air conditioner is controlled to enter the auxiliary valve opening adjustment mode again, and so on.

[0041] Of course, in addition to adjusting the current outdoor unit subcooling degree to be close to the target outdoor unit subcooling degree, in other embodiments, the auxiliary valve opening adjustment mode can also continuously increase the current outdoor unit subcooling degree by adjusting the opening of the auxiliary electronic expansion valve until the current outdoor unit subcooling degree is equal to the target lower limit threshold or the target upper limit threshold, thereby controlling the air conditioner to exit the auxiliary valve opening adjustment mode.

[0042] Optionally, in this embodiment, step S104, adjusting the opening of the auxiliary electronic expansion valve according to the current subcooling of the outdoor unit, may further include: determining whether the first-time acquired current subcooling of the outdoor unit is greater than or equal to the target lower threshold and less than or equal to the target upper threshold of the target threshold range; if so, controlling the air conditioner to enter the auxiliary valve opening adjustment mode. After the air conditioner is turned on and runs stably, the outdoor unit subcooling adjustment method of this application is executed. When the first-time acquired current subcooling of the outdoor unit is within the target threshold range, it indicates that the current subcooling of the outdoor unit and the cooling performance of the air conditioner can meet the requirements to a certain extent, but have not yet reached the optimal state. Therefore, the air conditioner is controlled to enter the auxiliary valve opening adjustment mode, and the opening of the auxiliary electronic expansion valve is adjusted to adjust the degree of compensation of the refrigerant in the subcooling auxiliary circuit to the subcooling of the outdoor unit and the system, so that the current subcooling of the outdoor unit gradually approaches and eventually dynamically stabilizes near the target subcooling of the outdoor unit, thereby keeping the air conditioner in the optimal cooling state.

[0043] In this embodiment, step S104, which adjusts the opening of the auxiliary electronic expansion valve according to the current subcooling degree of the outdoor unit, may further include: determining whether the current subcooling degree of the outdoor unit is greater than the target upper limit threshold of the target threshold range; if so, controlling the auxiliary electronic expansion valve to be in the closed state. When the current subcooling degree of the outdoor unit is greater than the target upper limit threshold, it indicates that the subcooling degree of the outdoor unit has exceeded the requirements. Accordingly, the air conditioner has higher cooling performance and does not need to be compensated for by the subcooling auxiliary circuit, thereby controlling the auxiliary electronic expansion valve to be in the closed state and the subcooling auxiliary circuit to be in the closed-loop state.

[0044] Specifically, the target threshold range can be [a, b], where a is the target upper threshold, a∈[5℃,10℃]; b is the target lower threshold, b∈[11℃,15℃]; and c is the target outdoor unit subcooling, which can be a value between a and b.

[0045] In the auxiliary valve opening adjustment mode, the step of opening the auxiliary electronic expansion valve and adjusting its opening to make the current outdoor unit subcooling within the target threshold range includes: obtaining the current compensated subcooling of the subcooling auxiliary circuit every preset time period as a cycle; determining the target opening of the auxiliary electronic expansion valve for the next cycle based on the current outdoor unit subcooling, the target lower limit threshold, and the current compensated subcooling; and adjusting the auxiliary electronic expansion valve to the target opening for the next cycle. After the air conditioner is running stably and enters the auxiliary valve opening adjustment mode, each preset time period is considered a cycle. The auxiliary electronic expansion valve operates at the current opening degree in the current cycle, and the refrigerant in the subcooling auxiliary circuit compensates for the subcooling of the outdoor unit and the system accordingly. At a certain moment in the current cycle, preferably the middle or end moment of the current cycle, the current subcooling of the outdoor unit and the target lower limit threshold are obtained. Based on the current subcooling of the outdoor unit, the subcooling compensation value that the subcooling auxiliary circuit needs to perform on the outdoor unit and the system is determined, i.e., the current compensation subcooling value. Then, the target opening degree of the auxiliary electronic expansion valve for the next cycle is determined, and the auxiliary electronic expansion valve is adjusted to operate at the target opening degree in the next cycle. This cycle is repeated, and by continuously adjusting the opening degree of the auxiliary electronic expansion valve, the degree of subcooling compensation of the refrigerant in the subcooling auxiliary circuit on the outdoor unit and the air conditioner is adjusted, so that the current subcooling of the outdoor unit in each cycle gradually approaches the target subcooling of the outdoor unit. At the same time, the change in the current subcooling of the outdoor unit in each cycle is relatively stable, reducing the occurrence of large fluctuations in cooling performance caused by large changes in the subcooling of the air conditioner. Specifically, the preset duration can be 20 seconds.

[0046] Specifically, in this embodiment, the step of "determining the target opening degree of the auxiliary electronic expansion valve for the next cycle based on the current outdoor unit subcooling, the target lower limit threshold, and the current compensated subcooling" includes: calculating the target opening degree of the auxiliary electronic expansion valve for the next cycle according to the opening degree adjustment formula, whereby:

[0047] P k+1 =P k +△P;

[0048] Among them, P k+1 To assist the electronic expansion valve in achieving its target opening degree in the next cycle, P k △P is the opening adjustment value of the auxiliary electronic expansion valve for the current cycle, representing the current opening degree of the auxiliary electronic expansion valve.

[0049] The opening adjustment value is calculated according to the following formula:

[0050] △P=(SC2 目标 -SC2 当前 )*S1*S2;

[0051] Among them, SC2 目标 The target compensation subcooling degree for the subcooling auxiliary circuit is the difference between the target lower limit threshold and the current subcooling degree of the outdoor unit; SC2当前 S1 is the current compensation subcooling degree for the subcooling auxiliary circuit, S2 is the compressor suction temperature correction coefficient in the air conditioner, and S2 is the compressor oil temperature correction coefficient.

[0052] First, the target compensation subcooling level SC2 for the subcooling auxiliary circuit is obtained based on the difference between the target lower limit threshold and the current subcooling level of the outdoor unit. 目标 To compensate for the undercooling deficit of the outdoor unit and system; then according to SC2 目标 The current compensation undercooling SC2 of the undercooled auxiliary road 当前 Determining the difference requires adjusting the opening value of the auxiliary electronic expansion valve in the current cycle, and correcting the opening adjustment value using the intake temperature correction coefficient S1 and the oil temperature correction coefficient S2 to obtain a more accurate opening adjustment value. The sum of the current opening value and the opening adjustment value of the auxiliary electronic expansion valve is used as the target opening value for the next cycle, thereby continuously adjusting the subcooling compensation value of the subcooled auxiliary circuit on a cycle-by-cycle basis. 当前 and SC2 目标 It continued to change until SC2 目标 With SC2 当前 When they are approximately equal, the opening adjustment value ΔP is approximately 0. Then, the current outdoor unit subcooling is close to the target outdoor unit subcooling and is in dynamic equilibrium. At this time, the air conditioner's cooling performance reaches its optimal state.

[0053] Specifically, the current subcooling degree SC1 of the outdoor unit can be obtained from the difference between the high-pressure saturation temperature Tc and the defrost temperature Tdef in the air conditioner. The high-pressure saturation temperature Tc can be calculated by detecting the high and low pressures at the high-pressure sensor at the compressor's suction port. The current subcooling compensation degree SC2 can be obtained from the outlet pipe temperature T of the subcooling auxiliary circuit extending from the gas-liquid separator. 出 The inlet pipe temperature T of the subcooled auxiliary line entering the gas-liquid separator 进 The difference is obtained. Specifically, as shown in the example... Figure 7 As shown, a defrost temperature sensor R4 can be installed at the refrigerant outlet of the outdoor unit to obtain the defrost temperature Tdef by detecting the refrigerant temperature at this location. A subcooling inlet temperature sensor R5 and a subcooling outlet temperature sensor R6 can be installed at both ends of the subcooling auxiliary circuit passing through the gas-liquid separator, respectively. The refrigerant temperature measured by R5 is the inlet temperature Tin, and the refrigerant temperature measured by R6 is the outlet temperature T. 出 .

[0054] Regarding the value of the inhalation temperature correction coefficient S1, the method further includes: if the inhalation temperature Ts is less than or equal to the lower limit threshold of the inhalation temperature threshold range, then the inhalation temperature correction coefficient S1 is 0.5m; if the inhalation temperature Ts is greater than the lower limit threshold of the inhalation temperature threshold range and less than the upper limit threshold of the inhalation temperature threshold range, then the inhalation temperature correction coefficient S1 is m; if the inhalation temperature Ts is greater than the upper limit threshold of the inhalation temperature threshold range, then the inhalation temperature correction coefficient S1 is 2m; where m is the base value of the inhalation temperature correction coefficient. If the suction temperature Ts is low, the refrigerant temperature at the inlet of the gas-liquid separator is low, and the temperature of the low-temperature liquid mixture at the bottom of the gas-liquid separator is also low. Correspondingly, the cooling effect of the low-temperature liquid mixture on the refrigerant passing through the subcooling auxiliary circuit is increased, that is, the current compensated subcooling degree of the subcooling auxiliary circuit is high. At this time, the suction temperature correction coefficient S1 is determined to be a small value to reduce the opening adjustment of the auxiliary electronic expansion valve in a single cycle, thereby improving the adjustment accuracy of the subcooling degree of the subcooling auxiliary circuit, and thus improving the adjustment accuracy of the subcooling degree of the outdoor unit and the system. Similarly, when the suction temperature Ts is large, the suction temperature correction coefficient S1 is determined to be a large value, and the opening adjustment of the auxiliary electronic expansion valve in a single cycle is increased to improve the adjustment accuracy of the subcooling degree of the outdoor unit and the system.

[0055] Specifically, the inhalation temperature threshold range can be [K1, K2], where K1 is the lower inhalation temperature threshold, K1∈[0℃, 5℃]; K2 is the upper inhalation temperature threshold, K2∈[15℃, 20℃]. m∈[1,1.5]. For example... Figure 7 As shown, a suction temperature sensor R2 can be installed in the pipeline between the four-way valve and the gas-liquid separator. The refrigerant temperature measured by R2 is the suction temperature Ts.

[0056] Regarding the value of the oil temperature correction coefficient, the method further includes: if the oil temperature is less than or equal to the lower limit threshold of the oil temperature threshold range, the oil temperature correction coefficient is 0.5n; if the oil temperature is greater than the lower limit threshold and less than the upper limit threshold of the oil temperature threshold range, the oil temperature correction coefficient is n; if the oil temperature is greater than the upper limit threshold, the oil temperature correction coefficient is 2n; where n is the base value of the oil temperature correction coefficient. Similar to the value of the intake temperature correction coefficient S1, when the oil temperature Toi is low, it indicates that the current compensation subcooling of the subcooling auxiliary circuit is high. At this time, the oil temperature correction coefficient S2 is determined to be a small value to reduce the opening adjustment of the auxiliary electronic expansion valve in a single cycle; when the oil temperature Toi is high, it indicates that the current compensation subcooling of the subcooling auxiliary circuit is low. At this time, the oil temperature correction coefficient S2 is determined to be a large value to increase the opening adjustment of the auxiliary electronic expansion valve in a single cycle, thereby improving the adjustment accuracy of the subcooling of the subcooling auxiliary circuit, and thus improving the adjustment accuracy of the subcooling of the outdoor unit and the system.

[0057] Specifically, the oil temperature threshold range can be [H1, H2], where H1 is the lower oil temperature threshold, H1∈[10℃, 20℃]; H2 is the upper oil temperature threshold, H2∈[40℃, 45℃]. n∈[1,1.5]. For example... Figure 7 As shown, an oil temperature sensor R3 can be installed on the oil distributor line. The lubricating oil temperature measured by R3 is the oil temperature Toi.

[0058] Specifically, in this embodiment, when the air conditioner enters the auxiliary valve opening adjustment mode, the auxiliary electronic expansion valve is controlled to open and its opening is adjusted to a preset opening. The preset opening is the average opening value of the indoor unit's electronic expansion valve. The opening value of the indoor unit's electronic expansion valve reflects the cooling effect of the indoor unit on the indoor environment. If the opening value of the indoor unit's electronic expansion valve is large, it indicates that the indoor unit's refrigerant demand is large and the cooling effect is poor, requiring an increase in subcooling. Conversely, if the opening value of the indoor unit's electronic expansion valve is small, it indicates that the indoor unit's refrigerant demand is small and the cooling effect is good, requiring no increase in subcooling. For multi-split air conditioners in cooling operation, when the air conditioner is determined to enter the auxiliary valve opening adjustment mode, the preset opening of the auxiliary electronic expansion valve is determined based on the opening of multiple indoor unit electronic expansion valves. The preset opening is taken as the average of the openings of multiple indoor unit electronic expansion valves. This allows for quick and accurate initial opening adjustment of the auxiliary electronic expansion valve, enabling the subcooling auxiliary circuit to quickly enter the compensation stage. Consequently, it reduces the occurrence of situations where the auxiliary electronic expansion valve starts adjusting from 0 pls, resulting in long adjustment time, poor adjustment effect, and poor subcooling effect.

[0059] Figure 2 This is a schematic flowchart of a second method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention. Figure 2 The method for adjusting the subcooling of the outdoor unit, as shown, includes:

[0060] S202 obtains the current outdoor unit subcooling level. SC1 当前 .

[0061] S204 determines the first SC1 acquired. 当前 Is the target lower threshold a greater than or equal to the target upper threshold b within the target threshold range? If yes, proceed to step S208; otherwise, proceed to step S206.

[0062] S206 determines SC1 当前 Is it less than a? If yes, proceed to step S208; if no, proceed to step S210.

[0063] S208 controls the air conditioner to enter the auxiliary valve opening adjustment mode. In the auxiliary valve opening adjustment mode, the opening of the auxiliary electronic expansion valve is adjusted so that the current outdoor unit subcooling degree gradually approaches the target outdoor unit subcooling degree within the target threshold range.

[0064] S210 determines SC1当前 Is it greater than b? If yes, proceed to step S212; if no, proceed to step S202.

[0065] S212 controls the auxiliary electronic expansion valve to be in the closed state.

[0066] Figure 3 This is a schematic flowchart of a third method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention. Figure 3 The method for adjusting the subcooling of the outdoor unit, as shown, includes:

[0067] S301 obtains SC1 当前 and SC2 当前 .

[0068] S302 determines SC1 当前 Is it less than a? If yes, proceed to step S303; if no, proceed to step S305.

[0069] S303 controls the air conditioner to enter the auxiliary valve opening adjustment mode.

[0070] The S304 controls the auxiliary electronic expansion valve to a preset opening degree, according to formula P. k+1 =P k +△P、△P=(SC2 目标 -SC2 当前 )*S1*S2、SC2 目标 =a-SC1 当前 Calculate the target opening degree of the auxiliary electronic expansion valve in the next cycle, and control the auxiliary electronic expansion valve to the target opening degree in the next cycle.

[0071] S305 determines SC1 当前 Is it greater than b? If yes, proceed to step S306; if no, proceed to step S301.

[0072] S306 controls the auxiliary electronic expansion valve to be in the closed state.

[0073] Specifically, the target threshold range can be set to [6℃, 12℃]. When the air conditioner is turned on, SC1 is obtained. 当前 =3℃, 3℃ < 6℃, therefore the air conditioner is controlled to enter the auxiliary valve opening adjustment mode; the openings of the four indoor unit electronic expansion valves of the multi-split unit are obtained as 90pls, 100pls, 80pls, and 120pls respectively, then the preset opening Pk = (90 + 100 + 80 + 120) / 4 = 100pls, and the opening of the auxiliary electronic expansion valve is adjusted to 100pls in the current cycle; SC2 目标 =6-3=3℃, S1=1, S2=2, obtain SC2 当前=0℃, then ΔP=(3-0)*1*2=6pls, then Pk+1=100+6=106pls; after the air conditioner runs for one cycle of 20s, the opening of the auxiliary electronic expansion valve is adjusted to 106pls, and this cycle continues. Indicatively, when SC1 is detected... 当前 When the temperature is 13℃, and 13℃ > 12℃, adjust the opening of the auxiliary electronic expansion valve to 0pls.

[0074] Turning on an air conditioner can include turning it on after a power outage, turning it on without interrupting the power outage, or turning it off when the indoor unit reaches the set temperature and then restarting.

[0075] Figure 4 This is a partial flowchart illustrating the fourth method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention. Figure 4 As shown, the specific steps for determining the value of S1 in step S304 include:

[0076] S402 obtains the compressor's suction temperature Ts.

[0077] S404 Determine whether Ts is less than or equal to the lower limit threshold K1 of the inhalation temperature; if yes, then set S1 = 0.5m; if no, then proceed to step S406.

[0078] S406 Determine whether Ts is greater than K1 and less than the upper limit threshold K2 of inhalation temperature; if yes, then set S1 = m; if no, then proceed to step S408.

[0079] S408 determines whether Ts is greater than or equal to K2; if so, then S1 = 2m.

[0080] Figure 5 This is a partial flowchart illustrating the fifth method for adjusting the subcooling of an outdoor unit according to an embodiment of the present invention. Figure 5 As shown, the specific steps for determining the value of S2 in step S304 include:

[0081] S502 obtains the compressor oil temperature Toi.

[0082] S504 Determine whether Toi is less than or equal to the lower limit threshold H1 of the inhalation temperature; if yes, then take S2 ​​= 0.5n; if no, then proceed to step S506.

[0083] S506 Determine whether Toi is greater than H1 and less than the upper limit threshold H2 of inhalation temperature; if yes, then set S2 = n; if no, then proceed to step S508.

[0084] S508 determines whether Toi is greater than or equal to H2; if so, then S2 = 2n.

[0085] Figure 6This is a schematic diagram of the control device provided in an embodiment of the present invention. Figure 6 As shown, this embodiment also provides a control device, including: an acquisition module 61 for acquiring the current subcooling degree of the outdoor unit; and a control module 62 for adjusting the opening of the auxiliary electronic expansion valve 720 according to the current subcooling degree of the outdoor unit. The main refrigerant path 610 between the outdoor unit 400 and the indoor unit of the air conditioner is connected in parallel to a subcooling auxiliary path 710. The subcooling auxiliary path 710 passes through the liquid refrigerant area of ​​the gas-liquid separator 500 in the air conditioner. The auxiliary electronic expansion valve 720 is located in the subcooling auxiliary path 710. This control device can adjust the opening of the auxiliary electronic expansion valve 720 in the subcooling auxiliary path 710 according to the degree of insufficiency of the current subcooling degree of the outdoor unit, thereby adjusting the compensation effect of the refrigerant in the subcooling auxiliary path 710 on the subcooling degree of the outdoor unit 400 and the system, so that the subcooling degree of the outdoor unit 400 and the system meets the requirements, ensuring the cooling performance of the air conditioner for the indoor environment and improving the user experience.

[0086] This embodiment also provides an air conditioner, including a computer-readable storage medium storing a computer program and a controller, wherein the computer program is read and executed by the controller to implement the above-described method for adjusting the subcooling of the outdoor unit.

[0087] This embodiment also provides a computer-readable storage medium storing a computer program, which is read and executed by the controller to implement the above-described method for adjusting the subcooling of the outdoor unit.

[0088] Of course, those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by computer-controlled devices. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above method embodiments. The storage medium can be a memory, a disk, an optical disk, etc.

[0089] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

[0090] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for adjusting the subcooling of an outdoor unit, characterized in that, The method is applied to an air conditioner, wherein the main refrigerant circuit (610) between the outdoor unit (400) and the indoor unit of the air conditioner is connected in parallel to a subcooling auxiliary circuit (710), the subcooling auxiliary circuit (710) passes through the liquid refrigerant region of the gas-liquid separator (500) in the air conditioner, and the subcooling auxiliary circuit (710) is equipped with an auxiliary electronic expansion valve (720); the method includes: Get the current subcooling level of the outdoor unit; Adjust the opening degree of the auxiliary electronic expansion valve (720) according to the current subcooling degree of the outdoor unit; The step of adjusting the opening of the auxiliary electronic expansion valve (720) according to the current subcooling of the outdoor unit includes: Determine whether the current subcooling of the outdoor unit is less than the target lower limit threshold of the target threshold range; If so, the air conditioner is controlled to enter the auxiliary valve opening adjustment mode. In the auxiliary valve opening adjustment mode, the auxiliary electronic expansion valve (720) is opened and its opening is adjusted so that the current subcooling degree of the outdoor unit is within the target threshold range. This step includes: Each preset time period constitutes one cycle. The current compensated subcooling degree of the subcooling auxiliary circuit is obtained. Based on the current outdoor unit subcooling degree, the target lower limit threshold, and the current compensated subcooling degree, the target opening degree of the auxiliary electronic expansion valve for the next cycle is determined. The target opening degree of the auxiliary electronic expansion valve (720) for the next cycle is calculated according to the opening degree adjustment formula, which is: P k+1 =P k +△P; Among them, P k+1 P is the target opening degree of the auxiliary electronic expansion valve in the next cycle. k The current opening degree of the auxiliary electronic expansion valve (720) in the current cycle, △P is the opening degree adjustment value of the auxiliary electronic expansion valve (720); The opening adjustment value is calculated according to the following formula: △P = (SC2 target - SC2 current) * S1 * S2; Wherein, SC2 target is the target compensation subcooling degree of the subcooling auxiliary circuit (710), which is the difference between the target lower limit threshold and the current subcooling degree of the outdoor unit; SC2 current is the current compensation subcooling degree of the subcooling auxiliary circuit (710); S1 is the suction temperature correction coefficient of the compressor in the air conditioner; and S2 is the oil temperature correction coefficient of the compressor. Adjust the auxiliary electronic expansion valve to the target opening degree for the next cycle.

2. The method for adjusting the subcooling of the outdoor unit according to claim 1, characterized in that, In the auxiliary valve opening adjustment mode, the opening of the auxiliary electronic expansion valve (720) is adjusted so that the current outdoor unit subcooling gradually approaches the target outdoor unit subcooling within the target threshold range.

3. The method for adjusting the subcooling of the outdoor unit according to claim 2, characterized in that, The step of adjusting the opening of the auxiliary electronic expansion valve (720) according to the current subcooling of the outdoor unit further includes: Determine whether the current subcooling of the outdoor unit obtained for the first time is greater than or equal to the target lower limit threshold and less than or equal to the target upper limit threshold of the target threshold range; If so, the air conditioner is controlled to enter the auxiliary valve opening adjustment mode.

4. The method for adjusting the subcooling of the outdoor unit according to any one of claims 1-3, characterized in that, The step of adjusting the opening of the auxiliary electronic expansion valve (720) according to the current subcooling of the outdoor unit includes: Determine whether the current subcooling of the outdoor unit is greater than the upper limit of the target threshold range; If so, the auxiliary electronic expansion valve (720) is controlled to be in the closed state.

5. The method for adjusting the subcooling of the outdoor unit according to claim 1, characterized in that, The method further includes: If the inhalation temperature is less than or equal to the lower limit of the inhalation temperature threshold range, then the inhalation temperature correction factor is 0.5m; If the inhalation temperature is greater than the lower limit threshold of the inhalation temperature and less than the upper limit threshold of the inhalation temperature range, then the inhalation temperature correction coefficient is taken as m; If the inhalation temperature is greater than the upper limit threshold of the inhalation temperature, then the inhalation temperature correction factor is 2m; Where m is the base value of the intake temperature correction coefficient.

6. The method for adjusting the subcooling of the outdoor unit according to claim 1, characterized in that, The method further includes: If the oil temperature is less than or equal to the lower limit of the oil temperature threshold range, then the oil temperature correction coefficient is 0.5n; If the oil temperature is greater than the lower limit threshold of the oil temperature and less than the upper limit threshold of the oil temperature range, then the oil temperature correction coefficient is n. If the oil temperature is greater than the upper limit threshold, the oil temperature correction coefficient is 2n; Where n is the base value of the oil temperature correction coefficient.

7. The method for adjusting the subcooling of the outdoor unit according to any one of claims 1-3, characterized in that, When the air conditioner enters the auxiliary valve opening adjustment mode, it controls the auxiliary electronic expansion valve (720) to open and adjusts its opening to a preset opening, which is the average opening value of the indoor unit electronic expansion valve of the air conditioner.

8. A control device, characterized in that, The control device, capable of implementing the outdoor unit subcooling adjustment method as described in any one of claims 1-7, comprises: The acquisition module (61) is used to acquire the current subcooling of the outdoor unit; The control module (62) is used to adjust the opening of the auxiliary electronic expansion valve (720) according to the current subcooling of the outdoor unit. The main refrigerant circuit (610) between the outdoor unit (400) and the indoor unit of the air conditioner is connected in parallel with the subcooling auxiliary circuit (710). The subcooling auxiliary circuit (710) passes through the liquid refrigerant area of ​​the gas-liquid separator (500) in the air conditioner. The auxiliary electronic expansion valve (720) is located in the subcooling auxiliary circuit (710).

9. An air conditioner, characterized in that, The method includes a computer-readable storage medium storing a computer program and a controller, wherein the computer program is read and executed by the controller to implement the outdoor unit subcooling adjustment method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which is read and executed by the controller to implement the outdoor unit subcooling adjustment method as described in any one of claims 1-7.

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