A method for perturbation control of an outer ring electronic expansion valve of an air conditioning system and an air conditioner

Abstract

This invention relates to the field of multi-split air conditioning system technology, specifically to a disturbance control method for the outer loop electronic expansion valve of an air conditioning system. The problem this invention addresses is how to actively eliminate oil and refrigerant blockage and reduce exhaust temperature during defrosting or oil return processes through forced disturbance control of the outer loop electronic expansion valve. To solve this problem, this invention provides a control method comprising: acquiring the operating status parameters of the air conditioning system; determining whether the air conditioning system has triggered a disturbance program based on the status parameters; correcting the reference setting based on the exhaust temperature, compressor return superheat, and oil separator return oil temperature during the execution of the disturbance mode; determining whether to exit the disturbance program based on the exhaust temperature and the execution duration of the disturbance program during defrosting and oil return modes; and automatically exiting the disturbance program when the air conditioning system exits the defrosting or oil return mode.

Description

Technical Field

[0001] This invention relates to the field of multi-split air conditioning system technology, and more specifically, to a method for controlling disturbances in the outer loop electronic expansion valve of an air conditioning system. Background Technology

[0002] In existing technologies, during the defrosting or oil return processes of multi-split air conditioners, the outdoor unit's heating electronic expansion valve typically employs fixed-opening control or PID regulation control based on superheat. Due to the drastic pressure fluctuations in defrosting and oil return modes, the refrigerant and refrigeration oil, when flowing through the throttling section of the electronic expansion valve, experience reduced flow velocity, temperature changes, and decreased solubility and increased viscosity of the low-temperature lubricating oil, leading to phase separation. This can easily result in lubricating oil accumulation and refrigerant retention, forming "oil blockage" or "refrigerant blockage." Once blockage occurs, it not only affects the defrosting effect or oil return efficiency but may also cause the compressor to operate with liquid or experience wear due to insufficient oil.

[0003] Furthermore, during defrosting or oil return, the low-pressure side of the system decreases and the compressor's suction volume increases. If the electronic expansion valve opening is not properly controlled, the compressor's discharge temperature can easily rise rapidly. Excessively high discharge temperatures accelerate lubricant carbonization, reduce compressor volumetric efficiency, and in severe cases, trigger the high-temperature discharge protection, causing the system to shut down.

[0004] Therefore, how to actively eliminate oil blockage and refrigerant blockage and reduce exhaust temperature through forced disturbance control of external thermoelectric expansion valve during defrosting or oil return is one of the problems that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The problem solved by this invention is how to actively eliminate oil blockage and refrigerant blockage and reduce exhaust temperature by using an external thermoelectric expansion valve to force disturbance control during defrosting or oil return processes.

[0006] To address the aforementioned problems, this invention provides a disturbance control method for the outer loop electronic expansion valve of an air conditioning system. The control method includes: acquiring the operating status parameters of the air conditioning system; determining whether the air conditioning system has triggered a disturbance program based on the status parameters; when the air conditioning system triggers a disturbance program, the controller initializes the disturbance control parameters and sets the disturbance period, disturbance reference opening degree, and disturbance duty cycle; the controller determines the disturbance mode based on the operating status of the outer loop electronic expansion valve, determines the opening degree of the outer loop electronic expansion valve based on the reference setting of the disturbance mode, and determines the duration of the disturbance mode based on the disturbance duty cycle; during the execution of the disturbance mode, the reference setting is corrected based on the exhaust temperature, compressor return superheat, and oil separator return oil temperature; in defrosting mode and oil return mode, it is determined whether to exit the disturbance program based on the exhaust temperature and the execution duration of the disturbance program; when the air conditioning system exits the defrosting mode or oil return mode, the disturbance program automatically exits.

[0007] Compared with existing technologies, the technical effects achieved by this solution are as follows: the setting of whether the air conditioning system triggers the disturbance program ensures that the disturbance program can be executed in a reasonable working mode; the setting of relevant parameters makes the execution of the disturbance program more in line with the working environment of the air conditioning system; the adjustment of the opening of the outer loop electronic expansion valve makes the initial adjustment method of the disturbance program more targeted; the acquisition of exhaust temperature, compressor return gas superheat and oil separator return oil temperature allows the disturbance program to effectively eliminate oil blockage and refrigerant blockage during execution, prevent the compressor from running with liquid or experiencing wear due to lack of oil, and reduce the risk caused by excessively high compressor exhaust temperature; the adaptive correction method also makes the entire air conditioning system more stable during the operation of the disturbance program and compatible with the operating requirements of more working conditions.

[0008] In one embodiment of the present invention, the coil temperature of the outdoor heat exchanger is obtained. When the coil temperature is lower than a preset defrost temperature threshold and the duration exceeds a preset time, the air conditioning system is determined to enter the defrost mode and a disturbance program is triggered; or, the cumulative running time of the compressor and the oil level are obtained. When the cumulative running time reaches a preset oil return cycle or the oil level is lower than a preset height, the air conditioning system is determined to enter the oil return mode and a disturbance program is triggered.

[0009] Compared with existing technologies, the technical effects achieved by this solution are as follows: the system can accurately determine whether the air conditioning system is in oil return mode or defrosting mode based on operating status parameters. This avoids the unnecessary activation of disturbance programs, reducing unnecessary energy consumption and wear. Simultaneously, it ensures timely activation of disturbance control when truly needed, effectively eliminating oil and refrigerant blockages, preventing compressor operation with liquid or wear due to oil shortage, and reducing the risks associated with excessively high compressor discharge temperatures.

[0010] In one embodiment of the present invention, the value range of the disturbance reference opening is 70%-100% of the maximum opening value of the outer ring electronic expansion valve, the time range of the disturbance period is 10-30 seconds, and the value range of the disturbance duty cycle is 40%-90%.

[0011] Compared with existing technologies, the technical effect achieved by adopting this technical solution is that by setting the range of values ​​for the disturbance period and the disturbance duty cycle, the controller can more accurately control the working state of the outer loop electronic expansion valve.

[0012] In one embodiment of the present invention, the controller performs forced disturbance control on the outer loop electronic expansion valve according to a set disturbance period and disturbance duty cycle. The forced disturbance control includes alternating forced valve closing disturbance and forced valve opening disturbance.

[0013] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: during the disturbance period, the forced valve closing disturbance mode and the forced valve opening disturbance mode are executed alternately to form periodic pressure fluctuations, thereby realizing the self-cleaning function of the pipeline.

[0014] In one embodiment of the present invention, the forced valve closure disturbance includes: during the valve closure period, the controller controls the outer loop electronic expansion valve to close rapidly to the minimum opening degree or the opening degree value is less than or equal to 5%, and determines the first disturbance time of the forced valve closure disturbance based on the disturbance duty cycle and the outdoor ambient temperature.

[0015] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: the forced valve closure disturbance setting allows the air conditioning system to clean the lubricating oil adhering to the valve port and the inner wall of the pipe in a timely manner, and the setting of the first disturbance time ensures the cleaning effect of the air conditioning system in the forced valve closure disturbance mode.

[0016] In one embodiment of the present invention, the forced valve opening disturbance includes: during the valve opening period, the controller controls the outer ring electronic expansion valve to open rapidly to the disturbance reference opening degree or opening degree value of 100%, and determines the second disturbance time of the forced valve closing disturbance according to the disturbance duty cycle and the outdoor ambient temperature.

[0017] Compared with existing technologies, the technical effects achieved by this solution are as follows: By subdividing the operating state of the outer-loop electronic expansion valve into valve-closing and valve-opening periods, and implementing targeted forced valve-closing and forced valve-opening disturbances, the accumulation of refrigerant and lubricating oil can be effectively removed, preventing blockages. Simultaneously, by rapidly opening the electronic expansion valve, the compressor discharge temperature can be effectively reduced, preventing compressor overheating protection shutdown and extending equipment life. The disturbance duration setting is dynamically determined based on the disturbance duty cycle and outdoor ambient temperature, making disturbance control more intelligent and adaptive. This avoids insufficient or excessive disturbance that may result from fixed parameter control, thus significantly improving defrosting and oil return efficiency while ensuring stable system operation and heating performance.

[0018] In one embodiment of the present invention, during the execution of the disturbance mode, the reference setting is corrected according to the exhaust temperature, the compressor return gas superheat and the oil separator return oil temperature. Specifically, this includes: when the exhaust temperature exceeds the high temperature threshold, shortening the disturbance period and increasing the duty cycle; when the superheat is lower than the superheat threshold, decreasing the duty cycle and shortening the duration of the valve opening period; and when the oil separator return oil temperature is lower than the return oil threshold, increasing the disturbance reference opening degree.

[0019] Compared with existing technologies, the technical effects achieved by this solution are as follows: By introducing a dynamic correction mechanism based on exhaust temperature, compressor return superheat, and oil separator return oil temperature, it solves the system instability problem that may occur in disturbance mode, ensuring that control parameters can respond to system state changes in real time. When the exhaust temperature is too high, shortening the disturbance cycle and increasing the duty cycle can quickly enhance the system's heat dissipation capacity, preventing compressor overheating and shutdown, and extending equipment life. When the superheat is too low, reducing the duty cycle and shortening the duration of the valve opening period can effectively prevent liquid refrigerant from entering the compressor. When the oil separator return oil temperature is too low, increasing the disturbance reference opening degree can promote the flow of lubricating oil, ensuring that the compressor is adequately lubricated and avoiding wear due to lack of oil. This dynamic correction mechanism makes disturbance control more precise and adaptive, significantly improving the operational stability and reliability of the air conditioning system in defrosting or oil return modes, while avoiding oil blockage and refrigerant blockage, ensuring the long-term efficient operation of the system.

[0020] In one embodiment of the present invention, determining whether to exit the disturbance program based on the exhaust temperature and the execution duration of the disturbance program specifically includes: when the exhaust temperature is lower than the exit temperature threshold and the exit duration continues, the controller stops the disturbance program; and / or; when the execution duration of the disturbance program is greater than the longest disturbance time, the controller stops the disturbance program.

[0021] Compared to existing technologies, the technical advantages of this solution are as follows: By introducing an intelligent disturbance exit mechanism, it ensures that disturbance control effectively solves system problems while avoiding unnecessary prolonged operation. The maximum disturbance time setting also ensures that the controller will forcibly stop the disturbance program even if the exhaust temperature has not fully met the exit conditions. This dual-judgment mechanism—based on real-time feedback from exhaust temperature and safety limits based on execution duration—works together to enable flexible and reliable termination of the disturbance program.

[0022] In one embodiment of the present invention, the control method further includes: while the disturbance program controls the outer loop electronic expansion valve, the controller synchronously adjusts the opening of the indoor unit electronic expansion valve to keep the indoor unit superheat within a preset range, so as to avoid the disturbance program affecting the heating effect on the indoor side.

[0023] Compared with existing technologies, the technical effects achieved by this solution are as follows: the controller synchronously adjusts the setting of the opening of the indoor unit's electronic expansion valve, so that the disturbance program can ensure the disturbance effect while also taking into account the working condition of the indoor unit, thereby improving the user's experience of using the air conditioning system after the disturbance mode is triggered.

[0024] This application also provides an air conditioner, in which the outer-loop electronic expansion valve disturbance control method described in the above embodiments is applied. The air conditioner includes: a judgment module for judging whether a disturbance program is triggered; an execution module, in which a controller is located, for performing disturbance control parameter initialization; a correction module for correcting the reference setting; and a calculation module for calculating the duration and execution time. The air conditioner has all the technical features of the above-described outer-loop electronic expansion valve disturbance control method, which will not be described in detail here. Attached Figure Description

[0025] Figure 1 This is one of the flowcharts for the electronic expansion valve disturbance control method of the present invention; Figure 2 This is the second flowchart of the electronic expansion valve disturbance control method of the present invention; Figure 3 This is the third flowchart of the electronic expansion valve disturbance control method of the present invention; Figure 4 This is a schematic diagram of the air conditioner system of the present invention.

[0026] Explanation of reference numerals in the attached figures: 100. Air conditioner; 110. Judgment module; 120. Execution module; 130. Correction module; 140. Calculation module. Detailed Implementation

[0027] 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.

[0028] [First Embodiment] See Figure 1 In one specific embodiment, this application provides a method for controlling disturbances in the outer loop electronic expansion valve of an air conditioning system. The control method includes: S100: Obtain the operating status parameters of the air conditioning system, and determine whether the air conditioning system has triggered a disturbance program based on the status parameters. S200. When the air conditioning system triggers the disturbance program, the controller performs disturbance control parameter initialization and sets the disturbance period, disturbance reference opening degree and disturbance duty cycle. S300: The controller determines the disturbance mode based on the working state of the outer loop electronic expansion valve, determines the opening degree of the outer loop electronic expansion valve based on the reference setting of the disturbance mode, and determines the duration of the disturbance mode based on the disturbance duty cycle. S400: During the execution of the disturbance mode, the reference setting is corrected based on the exhaust temperature, compressor return gas superheat and oil separator return oil temperature. S500: In defrost mode and oil return mode, the system determines whether to exit the disturbance program based on the exhaust temperature and the execution duration of the disturbance program; when the air conditioning system exits defrost mode or oil return mode, the disturbance program automatically exits.

[0029] In step S100, obtaining the operating status parameters of the air conditioning system refers to collecting key data such as temperature, pressure, and running time of the air conditioning system in real time through various sensors or internal system monitoring mechanisms. Determining whether the air conditioning system triggers a disturbance program based on the status parameters means that the system controller analyzes the obtained operating status parameters according to preset logic and conditions to decide whether the disturbance control program of the electronic expansion valve needs to be activated.

[0030] In step S200, the controller will provide different disturbance modes under different operating conditions. Normally, the disturbance program is only triggered when the air conditioner enters the defrosting mode and the oil return mode. After the disturbance program is triggered, the current opening value of the outer ring electronic expansion valve is obtained, and then the disturbance cycle, disturbance reference opening and disturbance duty cycle are determined according to the operating conditions.

[0031] In step S300, the reference setting refers to the basic values ​​of disturbance cycle, disturbance reference opening degree and disturbance duty cycle after the air conditioning system enters defrosting mode or oil return mode. Defrosting mode and oil return mode have different working environments, and different disturbance modes need to be given accordingly to ensure that the opening degree of the outer loop electronic expansion valve conforms to the current working state of the air conditioning system.

[0032] In step S400, as the working state of the outer ring electronic expansion valve changes, the exhaust temperature, compressor return gas superheat, and oil separator return oil temperature will also change. In order to avoid high exhaust temperature, compressor intake of liquid refrigerant, and disruption of the return oil circulation, it is necessary to make timely adaptive adjustments to the initial disturbance mode.

[0033] In step S500, based on the operating status parameters, it is determined whether the system has entered the heating defrosting mode or the oil return mode. When the system enters the defrosting mode or the oil return mode, the air conditioning system triggers the disturbance program, and the controller performs disturbance control parameter initialization. The disturbance program will only be started in the defrosting mode or the oil return mode. When the air conditioning system is not in the defrosting mode or the oil return mode, the disturbance program will not be triggered. Similarly, when the air conditioning system exits the defrosting mode or the oil return mode, the disturbance program will automatically stop. After the disturbance program exits, the air conditioning system will resume normal control.

[0034] Whether the air conditioning system triggers the disturbance program setting ensures that the disturbance program can be executed in a reasonable working mode. The setting of relevant parameters makes the execution of the disturbance program more in line with the working environment of the air conditioning system. The adjustment of the opening of the outer loop electronic expansion valve makes the initial adjustment method of the disturbance program more targeted. The acquisition of exhaust temperature, compressor return superheat and oil separator return oil temperature allows the disturbance program to effectively eliminate oil blockage and refrigerant blockage during execution, prevent the compressor from running with liquid or wearing due to lack of oil, and reduce the risk of excessive compressor exhaust temperature. The adaptive correction method also makes the entire air conditioning system more stable during the operation of the disturbance program and compatible with the operating requirements of more working conditions.

[0035] See Figure 2 Furthermore, the operating status parameters of the air conditioning system are obtained, and the system is used to determine whether it has triggered a disturbance program. Specifically, this includes: S110. Obtain the coil temperature of the outdoor heat exchanger. When the coil temperature is lower than the preset defrost temperature threshold and the duration exceeds the preset time, determine that the air conditioning system has entered the defrost mode and trigger the disturbance program; or; S120: Obtain the cumulative running time of the compressor and the oil level. When the cumulative running time reaches the preset oil return cycle or the oil level is lower than the preset height, determine that the air conditioning system has entered the oil return mode and trigger the disturbance program.

[0036] In step S110, the coil temperature of the outdoor heat exchanger is continuously monitored. Once the coil temperature drops below a preset critical temperature value (i.e., the defrost temperature threshold), the controller starts a timer. If the coil temperature remains below the threshold and the timer records a duration exceeding the preset duration, the system determines that there is a serious risk of frost buildup or potential refrigerant blockage, and determines that the air conditioning system is in defrost mode, thereby triggering a disturbance procedure.

[0037] In step S120, the cumulative running time of the compressor is usually recorded and accumulated by the timing module inside the controller; the oil level can be measured by a level sensor installed in the compressor oil tank to obtain the real-time position of the lubricating oil level in the oil tank.

[0038] In oil return mode, the current cumulative running time of the compressor is compared with the preset oil return cycle, or the real-time monitored oil level is compared with the preset minimum safe level. If either condition is met, the controller determines that the air conditioning system is in oil return mode, assuming there is a risk of insufficient oil return or oil shortage in the compressor, thus triggering a disturbance program. This judgment mechanism ensures that disturbance control can be activated promptly when the compressor needs oil return or the oil level is too low, preventing wear caused by oil shortage.

[0039] The system can accurately determine whether the air conditioning system is in oil return mode or defrost mode based on operating status parameters. This avoids the unnecessary activation of disturbance programs, reducing unnecessary energy consumption and wear. At the same time, it ensures that disturbance control can be activated in a timely manner when truly needed, effectively eliminating oil blockage and refrigerant blockage, preventing the compressor from operating with liquid or experiencing wear due to insufficient oil, and reducing the risks caused by excessively high compressor discharge temperatures.

[0040] Furthermore, the value range of the disturbance reference opening is 70%-100% of the maximum opening value of the outer ring electronic expansion valve, the time range of the disturbance period is 10-30 seconds, and the value range of the disturbance duty cycle is 40%-90%.

[0041] The initial value of the disturbance reference opening is preferably 85%, the initial value of the disturbance period length is preferably 15 seconds, and the disturbance duty cycle represents the proportion of time that the outer ring electronic expansion valve is in the open state within a complete disturbance period. The preferred initial value of the disturbance duty cycle is 60%.

[0042] By setting the range of values ​​for the disturbance period and disturbance duty cycle, the controller can more accurately control the working state of the outer loop electronic expansion valve.

[0043] Furthermore, the controller performs forced disturbance control on the outer loop electronic expansion valve according to the set disturbance period and disturbance duty cycle. The forced disturbance control includes alternating forced valve closing disturbance and forced valve opening disturbance.

[0044] The outer ring electronic expansion valve operates in two phases: a valve-closing phase and a valve-opening phase. During the valve-closing phase within the disturbance cycle, a forced valve-closing disturbance is performed. This forced valve-closing disturbance causes the upstream pressure of the throttling section to rise instantaneously and the downstream pressure to drop, forming a pressure shock wave that washes away the lubricating oil accumulation and refrigerant stagnation areas adhering to the valve port and the inner wall of the pipeline. During the valve-opening phase within the disturbance cycle, a forced valve-opening disturbance is performed. This forced valve-opening disturbance allows high-pressure refrigerant to quickly pass through the throttling section, carrying the washed-down lubricating oil and refrigerant towards the low-pressure side and into the compressor.

[0045] During the disturbance cycle, the forced valve closing disturbance mode and the forced valve opening disturbance mode are executed alternately to form periodic pressure fluctuations, thereby achieving the self-cleaning function of the pipeline.

[0046] Furthermore, the forced valve closure disturbance includes: during the valve closure period, the controller controls the outer loop electronic expansion valve to close rapidly to the minimum opening degree or the opening degree value is less than or equal to 5%, and determines the first disturbance time of the forced valve closure disturbance based on the disturbance duty cycle and the outdoor ambient temperature.

[0047] The operating state of the external loop electronic expansion valve refers to whether it is currently in a closing trend, an opening trend, or maintaining a certain opening degree. The valve closing period refers to the external loop electronic expansion valve being in a closed or tending to close state, at which time the refrigerant flow rate decreases.

[0048] The first disturbance time is the duration required to maintain the forced valve-closing disturbance. It is determined by the disturbance duty cycle and the outdoor ambient temperature. During the forced valve-closing disturbance, the closing speed of the outer loop electronic expansion valve is no less than 60 steps / second. During the change of the outer loop electronic expansion valve from its current opening to a smaller opening (e.g., minimum opening or opening value less than or equal to 5%), the stepper motor executes no less than 60 steps per second. This speed limit ensures that the valve can respond quickly to the closing command, rapidly reducing the amount of refrigerant and lubricating oil passing through the throttling section, thereby effectively preventing the formation or aggravation of oil blockage or refrigerant blockage.

[0049] The forced valve closure disturbance setting allows the air conditioning system to promptly clean the lubricating oil adhering to the valve port and the inner wall of the pipe. The setting of the first disturbance time ensures the cleaning effect of the air conditioning system in the forced valve closure disturbance mode.

[0050] Furthermore, the forced valve opening disturbance includes: during the valve opening period, the controller controls the outer loop electronic expansion valve to open rapidly to the disturbance reference opening degree or opening value of 100%, and determines the second disturbance time of the forced valve closing disturbance based on the disturbance duty cycle and the outdoor ambient temperature.

[0051] During the valve opening period, a forced valve opening disturbance is triggered. Rapid opening refers to the electronic expansion valve moving from its current opening degree to a larger opening degree at a relatively fast speed. The disturbance reference opening degree is a preset target opening degree value used for the forced valve opening disturbance; 100% opening degree indicates that the electronic expansion valve is fully open. The controller can send continuous, high-frequency opening step pulses to the electronic expansion valve, causing it to reach the disturbance reference opening degree or 100% opening degree within a short period of time. The second disturbance time is the length of time the forced valve opening disturbance needs to be maintained. It is determined by the disturbance duty cycle and the outdoor ambient temperature.

[0052] The opening speed of the outer loop electronic expansion valve is no less than 80 steps / second. This means that during a forced valve opening disturbance, the stepper motor executes no fewer than 80 steps per second as the outer loop electronic expansion valve changes from its current opening degree to a larger opening degree (e.g., the disturbance reference opening degree or the opening value of 100%). This speed limit ensures that the valve can respond quickly to the opening command, rapidly increase the refrigerant flow, promote system pressure balance, and help flush out any potential blockages.

[0053] Limiting the closing and opening speeds effectively solves the problems of incomplete blockage removal, low disturbance efficiency, and compromised system stability caused by insufficient valve action speed in traditional disturbance control.

[0054] Let the first disturbance time be t1, the second disturbance time be t2, and the period length of the disturbance be T. cycle The following relationship exists between the disturbance duty cycle D, the first disturbance time, the second disturbance time, the period length of the disturbance period, and the disturbance duty cycle; t1 = T cycle ×(1-D) t2=T cycle ×D.

[0055] By subdividing the operating state of the outer-loop electronic expansion valve into valve-closing and valve-opening periods, and implementing targeted forced valve-closing and forced valve-opening disturbances, the accumulation of refrigerant and lubricating oil can be effectively cleared, preventing blockages. Simultaneously, by rapidly opening the electronic expansion valve, the compressor discharge temperature can be effectively reduced, preventing compressor overheating protection shutdown and extending equipment life. The disturbance duration is dynamically determined based on the disturbance duty cycle and outdoor ambient temperature, making disturbance control more intelligent and adaptive. This avoids insufficient or excessive disturbance that may result from fixed parameter control, thus significantly improving defrosting and oil return efficiency while ensuring stable system operation and heating performance.

[0056] See Figure 3 Furthermore, during the execution of the disturbance mode, the baseline setting is corrected based on the exhaust temperature, compressor return gas superheat, and oil separator return oil temperature. Specifically, this includes: S410. When the exhaust temperature exceeds the high temperature threshold, shorten the disturbance period and increase the disturbance duty cycle. S420. When the superheat is below the superheat threshold, reduce the disturbance duty cycle and shorten the duration of the valve opening period. S430. When the return oil temperature is lower than the return oil threshold, increase the disturbance reference opening.

[0057] In step S410, the high temperature threshold can be set to 105℃. During the operation of the disturbance program, if the exhaust temperature is too high, it means that the compressor suction specific volume has increased and the exhaust is overheated, indicating insufficient refrigerant flow and oil circuit blockage. By setting the high temperature threshold, the flow of refrigerant and lubricating oil in the system can be ensured to be within a reasonable operating range.

[0058] Shortening the disturbance period can increase the disturbance frequency, generating more pressure waves per unit time, thereby enhancing the scouring effect.

[0059] Increasing the duty cycle means extending the valve opening time, which increases the total refrigerant flow and improves heat exchange efficiency. Essentially, it increases the disturbance intensity, solving the problem of high exhaust temperature caused by blockage through more frequent impacts and a more sufficient flow supply.

[0060] In step S420, superheat refers to the difference between the refrigerant vapor temperature at the compressor suction port and its saturation temperature at the current pressure. Typically, the compressor suction superheat is around 3°C to ensure that the refrigerant entering the compressor suction side is always in a gaseous state, avoiding "wet compression".

[0061] When the superheat is below the superheat threshold, it means that the compressor suction temperature is close to or below the saturation temperature at the current suction pressure, indicating that liquid refrigerant is entering or about to enter the compressor. This state may be caused by the following reasons in defrosting or oil return mode.

[0062] First: The electronic expansion valve is opened too wide, causing excessive refrigerant to enter the evaporator (or defrost circuit) and be sucked into the compressor before it can be completely evaporated.

[0063] Second: Overly aggressive disturbance control: The valve opening time is too long or the opening is too large, causing the liquid refrigerant to be drawn in before it can evaporate.

[0064] To address these two issues, by reducing the duty cycle, decreasing the supply of liquid refrigerant, increasing the throttling time, and protecting the compressor, the superheat is kept within a safe range. By sacrificing some disturbance intensity in exchange for system safety, the disturbance mode can have a more reasonable adaptive logic.

[0065] In step S430, if the oil separator return oil temperature is lower than the return oil threshold, it indicates insufficient oil return volume. This could be due to either oil blockage in the return oil line or insufficient refrigerant flow rate to carry the oil. When this occurs, the refrigerant flow rate can be increased by increasing the disturbance opening. High-speed flowing refrigerant has a stronger "carrying" and "shearing" ability on the oil film in the return oil line, capable of peeling off and carrying away the lubricating oil adhering to the pipe wall.

[0066] Alternatively, by increasing the system circulation volume, more refrigerant can participate in the circulation, which can more effectively carry the separated lubricating oil back to the compressor.

[0067] This problem can also be solved by increasing the system pressure level. After the disturbance reference opening is increased, the pressure on the low-pressure side of the system rises, which helps to improve the pressure difference conditions of the return oil pipeline and overcome the flow resistance of the oil blockage.

[0068] For example, when the air conditioning system performs defrosting or oil return disturbance procedures, the controller can continuously collect data from the exhaust temperature sensor, intake temperature sensor, and pressure sensor. Using this sensor data, the controller calculates the compressor return superheat in real time. When the controller detects that the exhaust temperature exceeds the high-temperature threshold of 115°C, the initially set disturbance period of 60 seconds and duty cycle of 50% can be immediately shortened to 40 seconds and the duty cycle increased to 70%. This means that the switching frequency of the outer-loop electronic expansion valve increases, and the opening time is longer each time, thus enhancing the heat dissipation effect.

[0069] When the controller calculates that the compressor return gas superheat is below the superheat threshold of 4°C, with an initial duty cycle of 70% and a valve opening period duration of 28 seconds (based on a 40-second cycle and a 70% duty cycle), the controller can immediately reduce the duty cycle to 50% and shorten the valve opening period duration to 20 seconds. This helps reduce the risk of liquid refrigerant entering the compressor.

[0070] When the controller detects that the oil separator return oil temperature is below the return oil threshold of 22°C, the initially set disturbance reference opening is 80%. The controller can immediately increase the disturbance reference opening to 95%. This allows the outer loop electronic expansion valve to achieve a larger opening when it opens, thereby promoting the flow of lubricating oil. These corrected parameters are immediately applied to the control commands of the outer loop electronic expansion valve, thereby achieving dynamic optimization of the disturbance mode.

[0071] By introducing a dynamic correction mechanism based on exhaust temperature, compressor return superheat, and oil separator return oil temperature, the system instability issues that may occur in disturbance mode are resolved. This ensures that control parameters respond to system state changes in real time. When the exhaust temperature is too high, shortening the disturbance cycle and increasing the duty cycle can quickly enhance the system's heat dissipation capacity, preventing compressor overheating and shutdown, and extending equipment life. When the superheat is too low, reducing the duty cycle and shortening the duration of the valve opening period can effectively prevent liquid refrigerant from entering the compressor. When the oil separator return oil temperature is too low, increasing the disturbance reference opening degree can promote lubricating oil flow, ensuring sufficient lubrication of the compressor and preventing wear due to lack of oil. This dynamic correction mechanism makes disturbance control more precise and adaptive, significantly improving the operational stability and reliability of the air conditioning system in defrosting or oil return modes, while avoiding oil blockage and refrigerant blockage, ensuring long-term efficient operation of the system.

[0072] Furthermore, in defrosting mode and oil return mode, the system determines whether to exit the disturbance program based on the exhaust temperature and the execution duration of the disturbance program, specifically including: S510. When the exhaust temperature is lower than the exit temperature threshold and the exit time continues, the controller stops the disturbance program; and / or; S520. When the execution duration of the disturbance program exceeds the maximum disturbance time, the controller stops the disturbance program.

[0073] If the disturbance program is not exited in time when the exhaust temperature is too high, it will aggravate compressor wear or lubricant carbonization. Excessive disturbance time will also lead to reduced system efficiency and even unnecessary energy consumption. During the disturbance process, system pressure fluctuations and temperature changes may cause the risk of oil blockage or refrigerant blockage to persist. If the exit conditions are not precise, the blockage may not be effectively eliminated or the disturbance effect may be insufficient.

[0074] In steps S510 to S520, the exhaust temperature can be obtained by installing a temperature sensor on the compressor exhaust line. The execution duration of the disturbance program refers to the time elapsed since the disturbance program was started. This duration is used to record the time the disturbance program has been running. The exit temperature threshold is a preset upper limit of safe temperature. When the exhaust temperature is below this threshold, it indicates that the system operating state is becoming stable, the risk of compressor overheating is reduced, and the risk of oil blockage or refrigerant blockage may also be alleviated. The exit temperature threshold is set according to the design parameters of the air conditioning system, refrigerant characteristics, and the safe operating range of the compressor, and is usually set to 80°C or 90°C. The continuous exit duration refers to the time required for the exhaust temperature to remain below the exit temperature threshold. Setting the continuous exit duration is to avoid misjudgment caused by instantaneous temperature fluctuations and to ensure that the system exits the disturbance program only after it has reached a stable and safe state. This duration can be set according to the dynamic response characteristics of the system and empirical values, and is usually set to 30 seconds or 60 seconds. When the exit conditions are met, the controller will terminate the current disturbance control strategy.

[0075] For example, the system's preset exit temperature threshold is 85°C, the continuous exit duration is 45 seconds, and the maximum disturbance time is 12 minutes. During the disturbance program execution, if the controller detects that the exhaust temperature drops to 80°C and remains below 85°C for 45 seconds, the controller will immediately stop the disturbance program and restore the outer loop electronic expansion valve to normal control mode. Alternatively, if the disturbance program has been running for 12 minutes but the exhaust temperature still does not meet the condition of remaining below the exit temperature threshold, the controller will also forcibly stop the disturbance program to prevent it from running indefinitely. In this way, the controller can intelligently determine the termination time of the disturbance program based on actual operating conditions and preset safety policies.

[0076] By introducing an intelligent disturbance exit mechanism, the disturbance control effectively addresses system issues while avoiding unnecessary prolonged operation. A maximum disturbance time setting ensures the controller forcibly stops the disturbance program even if the exhaust temperature hasn't fully met the exit conditions. This dual-judgment mechanism—based on real-time feedback from exhaust temperature and safety limits on execution duration—works together to enable flexible and reliable termination of the disturbance program.

[0077] Furthermore, the electronic expansion valve disturbance control method further includes: The length of the disturbance cycle is determined by the refrigerant charge and compressor displacement of the air conditioning system, using the following formula: ; in, The period length, This is an empirical coefficient. This refers to the refrigerant charge. This refers to the compressor's displacement. This is the baseline compensation value.

[0078] Refrigerant charge M ref V refers to the total mass or volume of refrigerant filling the air conditioning system. comp This refers to the volume of refrigerant vapor that the compressor can draw in and discharge per unit time. This parameter reflects the compressor's working capacity and the flow rate of refrigerant it can handle. The empirical coefficient 'a' is usually determined through extensive experimental data, simulation, or on-site commissioning to ensure that the calculated disturbance period can optimally adapt to different types or operating conditions of air conditioning systems. The baseline compensation value 'b' can be used to compensate for the influence of inherent system characteristics, sensor errors, or specific operating environment factors that are not fully considered in the formula on the disturbance period. The baseline compensation value 'b' can be a fixed value or can be fine-tuned according to certain auxiliary parameters (such as ambient temperature, system load, etc.) to further improve the accuracy of the disturbance period setting.

[0079] By optimizing the disturbance cycle, system pressure fluctuations can be managed more effectively, preventing the compressor exhaust temperature from rising too quickly, reducing the risk of triggering the exhaust high temperature protection, and thus ensuring the long-term stable operation of the compressor and the overall reliability of the system.

[0080] Furthermore, the control method also includes: while the disturbance program controls the outer loop electronic expansion valve, the controller synchronously adjusts the opening of the indoor unit's electronic expansion valve to keep the indoor unit's superheat within a preset range, thus avoiding the disturbance program from affecting the heating effect on the indoor side.

[0081] During the adjustment of the outer loop electronic expansion valve, in order to prevent the disturbance program from affecting the indoor heating effect, the opening of the indoor unit's electronic expansion valve needs to be changed along with the disturbance mode. The adjustment method of the indoor unit's electronic expansion valve corresponds to the adjustment method of the outer loop electronic expansion valve. The controller can read the preset adjustment method by observing the change in the opening of the outer loop electronic expansion valve.

[0082] The controller synchronously adjusts the opening setting of the indoor unit's electronic expansion valve, ensuring that the disturbance program takes into account the indoor unit's operating status while ensuring the disturbance effect, thus improving the user experience of using the air conditioning system after the disturbance mode is triggered.

[0083] [Second Embodiment] See Figure 4 This application also provides an air conditioner 100, in which the outer-loop electronic expansion valve disturbance control method described in the above embodiments is applied. The air conditioner 100 includes: a judgment module 110, which is used to judge whether a disturbance program is triggered; an execution module 120, in which a controller is located, which is used to perform disturbance control parameter initialization; a correction module 130, which is used to correct the reference setting; and a calculation module 140, which is used to calculate the duration and execution time. The air conditioner 100 has all the technical features of the above-described outer-loop electronic expansion valve disturbance control method, which will not be described in detail here.

[0084] 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.

Claims

1. A method for controlling disturbances in the outer loop electronic expansion valve of an air conditioning system, characterized in that, The control method includes: Obtain the operating status parameters of the air conditioning system, and determine whether the air conditioning system has triggered a disturbance program based on the status parameters; When the air conditioning system triggers the disturbance procedure, the controller performs disturbance control parameter initialization and sets the disturbance period, disturbance reference opening degree and disturbance duty cycle; The controller determines the disturbance mode based on the working state of the outer ring electronic expansion valve, determines the opening degree of the outer ring electronic expansion valve based on the reference setting of the disturbance mode, and determines the duration of the disturbance mode based on the disturbance duty cycle. During the execution of the disturbance mode, the reference setting is corrected based on the exhaust temperature, compressor return gas superheat, and oil separator return oil temperature; In defrosting mode and oil return mode, it is determined whether to exit the disturbance program based on the exhaust temperature and the execution duration of the disturbance program; When the air conditioning system exits the defrosting mode or the oil return mode, the disturbance program automatically exits.

2. The disturbance control method for the outer loop electronic expansion valve of the air conditioning system according to claim 1, characterized in that, The step of acquiring the operating status parameters of the air conditioning system and determining whether the air conditioning system has triggered a disturbance program based on the status parameters specifically includes: The temperature of the outdoor heat exchanger coil is obtained. When the temperature of the coil is lower than the preset defrost temperature threshold and the duration exceeds the preset time, the air conditioning system is determined to enter the defrost mode, and the disturbance program is triggered; or; The system acquires the cumulative running time of the compressor and the oil level. When the cumulative running time reaches a preset oil return cycle or the oil level is lower than a preset height, the system determines that the air conditioning system has entered the oil return mode and triggers a disturbance program.

3. The disturbance control method for the outer loop electronic expansion valve of the air conditioning system according to claim 2, characterized in that, The value range of the disturbance reference opening is 70%-100% of the maximum opening value of the outer ring electronic expansion valve, the time range of the disturbance period is 10-30 seconds, and the value range of the disturbance duty cycle is 40%-90%.

4. The disturbance control method for the outer loop electronic expansion valve of the air conditioning system according to claim 3, characterized in that, The controller performs forced disturbance control on the outer ring electronic expansion valve according to the set disturbance period and the disturbance duty cycle. The forced disturbance control includes alternating forced valve closing disturbance and forced valve opening disturbance.

5. The disturbance control method for the outer loop electronic expansion valve of the air conditioning system according to claim 4, characterized in that, The forced valve closure disturbance includes: During the valve closing period, the controller controls the outer ring electronic expansion valve to close rapidly to the minimum opening degree or the opening degree value is less than or equal to 5%, and determines the first disturbance time of the forced valve closing disturbance based on the disturbance duty cycle and the outdoor ambient temperature.

6. The disturbance control method for the outer loop electronic expansion valve of the air conditioning system according to claim 4, characterized in that, The forced valve opening disturbance includes: During the valve opening period, the controller controls the outer ring electronic expansion valve to quickly open to the disturbance reference opening degree or opening value of 100%, and determines the second disturbance time of the forced valve closing disturbance based on the disturbance duty cycle and the outdoor ambient temperature.

7. The method for controlling disturbance of the outer loop electronic expansion valve of an air conditioning system according to any one of claims 1 to 6, characterized in that, During the execution of the disturbance mode, the reference setting is corrected based on the exhaust temperature, compressor return gas superheat, and oil separator return oil temperature. Specifically, this includes: When the exhaust temperature exceeds the high temperature threshold, the disturbance period is shortened and the disturbance duty cycle is increased; When the superheat is below the superheat threshold, the disturbance duty cycle is reduced and the duration of the valve opening period is shortened; When the return oil temperature is lower than the return oil threshold, the disturbance reference opening is increased.

8. The method for controlling disturbance of the outer loop electronic expansion valve of an air conditioning system according to any one of claims 1 to 6, characterized in that, In the defrosting mode and the oil return mode, determining whether to exit the disturbance program based on the exhaust temperature and the execution duration of the disturbance program specifically includes: When the exhaust temperature is lower than the exit temperature threshold and remains below the exit time, the controller stops executing the disturbance program; and / or; When the execution duration of the disturbance program exceeds the maximum disturbance time, the controller stops executing the disturbance program.

9. The method for controlling disturbance of the outer loop electronic expansion valve of an air conditioning system according to any one of claims 1 to 6, characterized in that, The control method further includes: While the disturbance program controls the outer loop electronic expansion valve, the controller synchronously adjusts the opening of the indoor unit's electronic expansion valve to keep the indoor unit's superheat within a preset range, thus preventing the disturbance program from affecting the heating effect on the indoor side.

10. An air conditioner, characterized in that, The external loop electronic expansion valve disturbance control method of the air conditioning system as described in any one of claims 1 to 9 is applied to the air conditioner, the air conditioner comprising: A judgment module, used to determine whether the disturbance program is triggered; An execution module is provided, wherein the controller is located within the execution module, and the execution module is used to perform the initialization of the disturbance control parameters; The correction module is used to correct the reference setting; A calculation module is used to calculate the duration and the execution time.

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