Control methods for electronic expansion valves, heat pump systems, and storage media

Abstract

This invention discloses a control method for an electronic expansion valve, a heat pump system, and a storage medium. The method includes: upon receiving a shutdown command from the heat pump system, detecting a pressure value related to the operation of the electronic expansion valve in the heat pump system; and controlling the opening degree of the electronic expansion valve based on the pressure value to achieve a pressure balance state in the heat pump system. This invention aims to reduce wear on the electronic expansion valve after the heat pump system shuts down and improve its service life.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, and more particularly to a control method for an electronic expansion valve, a heat pump system, and a storage medium. Background Technology

[0002] Heat pump systems (such as heat pump systems) typically use electronic expansion valves for throttling and pressure reduction to achieve normal heat exchange cycles.

[0003] Currently, when a heat pump system is shut down, the electronic expansion valve is directly controlled to increase its opening to relieve pressure and achieve pressure balance. However, when the system is shut down, there will be a sudden pressure change. The current control method of the electronic expansion valve is prone to causing wear on the valve needle and other structures in the electronic expansion valve, reducing the service life of the electronic expansion valve. Summary of the Invention

[0004] The main objective of this invention is to provide a control method for an electronic expansion valve, a heat pump system, and a storage medium, which aims to reduce wear on the electronic expansion valve after the heat pump system is shut down and improve the service life of the electronic expansion valve.

[0005] To achieve the above objectives, the present invention provides a control method for an electronic expansion valve, the control method comprising the following steps:

[0006] When a shutdown command is received from the heat pump system, the pressure value related to the operation of the electronic expansion valve in the heat pump system is detected.

[0007] The opening degree of the electronic expansion valve is controlled according to the pressure value so that the heat pump system reaches a pressure balance state.

[0008] Optionally, the step of controlling the opening of the electronic expansion valve according to the pressure value to achieve a pressure balance state in the heat pump system includes:

[0009] When the pressure value is not greater than the preset pressure threshold, the electronic expansion valve is controlled to increase its opening.

[0010] When the pressure value is greater than the preset pressure threshold, the electronic expansion valve is controlled to maintain the current opening.

[0011] Optionally, the step of controlling the electronic expansion valve to increase its opening includes:

[0012] Control the electronic expansion valve to increase to a first preset opening degree, the preset opening degree being greater than the current opening degree of the electronic expansion valve; or,

[0013] The electronic expansion valve is controlled to increase its opening based on the pressure value.

[0014] Optionally, the step of controlling the electronic expansion valve to increase its opening based on the pressure value includes:

[0015] Determine the pressure difference between the preset pressure threshold and the pressure value;

[0016] The opening adjustment value is determined based on the pressure difference value;

[0017] The electronic expansion valve is controlled to increase its opening by the opening adjustment value.

[0018] Optionally, the step of detecting the pressure value related to the operation of the electronic expansion valve in the heat pump system when a shutdown command is received includes:

[0019] When a shutdown command is received from the heat pump system, the pressure values ​​at both ends of the electronic expansion valve are detected to obtain a first pressure value and a second pressure value.

[0020] Optionally, the step of controlling the opening of the electronic expansion valve according to the pressure value to achieve a pressure balance state in the heat pump system includes:

[0021] Determine the maximum pressure value between the first pressure value and the second pressure value;

[0022] The opening degree of the electronic expansion valve is controlled according to the maximum pressure value so that the heat pump system reaches a pressure balance state.

[0023] Optionally, the step of detecting the pressure value related to the operation of the electronic expansion valve in the heat pump system when a shutdown command is received includes:

[0024] When a shutdown command for the heat pump system is received, the shutdown duration of the heat pump system is obtained;

[0025] When the downtime reaches the first preset time, the pressure value related to the operation of the electronic expansion valve in the heat pump system is detected.

[0026] Optionally, after the step of controlling the opening of the electronic expansion valve according to the pressure value to make the heat pump system reach a pressure balance state, the method further includes:

[0027] Obtain the downtime of the heat pump system;

[0028] When the downtime reaches the second preset time, the electronic expansion valve is controlled to reset to the second preset opening degree.

[0029] Furthermore, to achieve the above objectives, this application also proposes a heat pump system, the heat pump system comprising:

[0030] Electronic expansion valve;

[0031] A pressure detection module is disposed at at least one end of the electronic expansion valve;

[0032] A control device is provided, wherein the electronic expansion valve and the pressure detection module are both connected to the control device. The control device includes: a memory, a processor, and a control program for the electronic expansion valve stored in the memory and executable on the processor. When the control program for the electronic expansion valve is executed by the processor, it implements the steps of the control method for the electronic expansion valve as described in any of the preceding claims.

[0033] Optionally, the pressure detection module includes a first pressure sensor and a second pressure sensor respectively disposed at both ends of the electronic expansion valve, and both the first pressure sensor and the second pressure sensor are connected to the control device.

[0034] In addition, to achieve the above objectives, this application also proposes a storage medium storing a control program for an electronic expansion valve, wherein the control program for the electronic expansion valve, when executed by a processor, implements the steps of the control method for the electronic expansion valve as described in any of the preceding claims.

[0035] This invention proposes a control method for an electronic expansion valve. When a shutdown command is received from a heat pump system, the method detects the pressure value related to the operation of the electronic expansion valve in the heat pump system, and adjusts the opening degree of the electronic expansion valve according to the pressure value to achieve a balanced system pressure. This ensures that the opening degree adjustment of the electronic expansion valve can match the actual system pressure state, thereby effectively reducing the wear of the electronic expansion valve after the heat pump system is shut down and improving the service life of the electronic expansion valve. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the refrigerant system structure of an embodiment of the heat pump system of the present invention;

[0037] Figure 2 This is a schematic diagram of the hardware structure involved in the operation of an embodiment of the heat pump system of the present invention;

[0038] Figure 3 This is a schematic flowchart of an embodiment of the control method for the electronic expansion valve of the present invention;

[0039] Figure 4 This is a schematic flowchart of another embodiment of the control method for the electronic expansion valve of the present invention;

[0040] Figure 5 This is a flowchart illustrating another embodiment of the control method for the electronic expansion valve of the present invention.

[0041] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0042] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0043] This invention provides a heat pump system. In this embodiment, the heat pump system is an air conditioner. In other embodiments, the heat pump system may also be other types of equipment, such as a heat pump water heater, a refrigerator, etc.

[0044] In this embodiment of the invention, reference is made to Figure 1 and Figure 2 The heat pump system includes a control device 100, a compressor 200, a first heat exchanger 400, an electronic expansion valve 300, and a second heat exchanger 500.

[0045] The first heat exchanger 400, the electronic expansion valve 300, and the second heat exchanger 500 are connected in sequence. The first heat exchanger 400 and the second heat exchanger 500 are respectively connected to the exhaust port of the compressor 200 and the return port of the compressor 200.

[0046] In one implementation, the first heat exchanger 400 is connected to the exhaust port, and the second heat exchanger 500 is connected to the return port. When the compressor 200 is turned on, the refrigerant flows sequentially through the first heat exchanger 400, the electronic expansion valve 300, and the second heat exchanger 500 before returning to the compressor 200.

[0047] In another implementation, the first heat exchanger 400 is connected to the return port, and the second heat exchanger 500 is connected to the exhaust port. When the compressor 200 is turned on, the refrigerant flows sequentially through the second heat exchanger 500, the electronic expansion valve 300, and the first heat exchanger 400 before returning to the compressor 200.

[0048] In another implementation, the heat pump system may further include a reversing assembly 600 (e.g., a four-way valve), with the first heat exchanger 400, the second heat exchanger 500, the exhaust port of the compressor 200, and the return port of the compressor 200 all connected to the reversing assembly 600. The reversing assembly 600 has a first operating state and a second operating state. When the reversing assembly 600 operates in the first operating state, the first heat exchanger 400 is connected to the exhaust port, and the second heat exchanger 500 is connected to the return port. When the compressor 200 is turned on, the refrigerant flows sequentially through the first heat exchanger 400, the electronic expansion valve 300, and the second heat exchanger 500 before returning to the compressor 200. When the reversing assembly 600 operates in the second operating state, the first heat exchanger 400 is connected to the return port, and the second heat exchanger 500 is connected to the exhaust port. When the compressor 200 is turned on, the refrigerant flows sequentially through the second heat exchanger 500, the electronic expansion valve 300, and the first heat exchanger 400 before returning to the compressor 200.

[0049] Furthermore, in this embodiment, referring to Figure 1 and Figure 2The heat pump system may further include a pressure detection module 700, which is connected to the control device 100 to detect pressure values ​​related to the operation of the electronic expansion valve 300 in the heat pump system. The pressure detection module 700 may include one or more pressure sensors. In this embodiment, the pressure detection module 700 is located at at least one end of the electronic expansion valve 300.

[0050] The pressure detection module 700 includes a first pressure sensor 701 and a second pressure sensor 702 respectively disposed at both ends of the electronic expansion valve 300. Both the first pressure sensor 701 and the second pressure sensor 702 are connected to the control device 100. The first pressure sensor 701 is used to detect the refrigerant pressure at one end of the electronic expansion valve 300, and the second pressure sensor 702 is used to detect the refrigerant pressure at the other end of the electronic expansion valve 300.

[0051] In other embodiments, the pressure detection module 700 may also be located on at least one side of the compressor 200 or on the first heat exchanger 400 and / or the second heat exchanger 500.

[0052] In this embodiment of the invention, reference is made to Figure 2 The control device 100 includes a processor 1001, such as a CPU, a memory 1002, and a timer 1003. These components communicate with each other via a communication bus. The memory 1002 can be high-speed RAM or non-volatile memory, such as a disk drive. Optionally, the memory 1002 can also be a storage device independent of the aforementioned processor 1001.

[0053] Those skilled in the art will understand that Figure 2 The device structure shown does not constitute a limitation on the device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0054] like Figure 2 As shown, the memory 1002, which serves as a computer storage medium, may include a control program for the electronic expansion valve 300.

[0055] exist Figure 2 In the device shown, the processor 1001 can be used to call the control program of the electronic expansion valve 300 stored in the memory 1002 and execute the relevant steps of the control method of the electronic expansion valve 300 in the following embodiments.

[0056] This invention also provides a control method for an electronic expansion valve, applied to the aforementioned heat pump system.

[0057] Reference Figure 3This application proposes an embodiment of a control method for an electronic expansion valve. In this embodiment, the control method for the electronic expansion valve includes:

[0058] Step S10: When a shutdown command for the heat pump system is received, the pressure value related to the operation of the electronic expansion valve in the heat pump system is detected.

[0059] The shutdown command can be input by the user or generated when the heat pump system is detected to have reached the shutdown condition. When a shutdown command is received from the heat pump system, the compressor is controlled to shut down and the pressure value is monitored.

[0060] The pressure value can be obtained from the pressure data currently detected by the pressure detection module, or it can be determined from the pressure data detected by the pressure detection module within a certain period of time after shutdown, or it can be determined from the first pressure data detected by the pressure detection module before shutdown and the second pressure data detected after shutdown.

[0061] Step S20: Control the opening degree of the electronic expansion valve according to the pressure value so that the heat pump system reaches a pressure balance state.

[0062] The opening control parameters of the electronic expansion valve are determined based on the pressure value. Different pressure values ​​correspond to different opening control parameters of the electronic expansion valve, and the operation of the electronic expansion valve is controlled according to the opening control parameters.

[0063] The determined opening control parameters are those that allow the heat pump system to be unloaded but whose impact force on the internal structural components of the electronic expansion valve is less than the preset pressure. The opening control parameters include, but are not limited to, at least one of the following parameters: target opening degree, opening adjustment rate, opening adjustment amplitude, opening adjustment ratio, opening adjustment direction (increasing the opening degree, decreasing the opening degree, or maintaining the current opening degree), etc.

[0064] In one implementation, the opening control parameters can be determined based on the pressure range in which the pressure value is located, and the electronic expansion valve can be controlled to operate according to the opening control parameters.

[0065] In another implementation, the opening control parameters can be determined based on the magnitude or quantity relationship between the pressure value and the preset pressure value, and the electronic expansion valve can be controlled to operate according to the opening control parameters.

[0066] This invention proposes a control method for an electronic expansion valve. When a shutdown command is received from a heat pump system, the method detects the pressure value related to the operation of the electronic expansion valve in the heat pump system, and adjusts the opening degree of the electronic expansion valve according to the pressure value to achieve a balanced system pressure. This ensures that the opening degree adjustment of the electronic expansion valve can match the actual system pressure state, thereby effectively reducing the wear of the electronic expansion valve after the heat pump system is shut down and improving the service life of the electronic expansion valve.

[0067] Furthermore, based on the above embodiments, another embodiment of the control method for the electronic expansion valve of this application is proposed. In this embodiment, reference is made to... Figure 4 Step S20 includes:

[0068] Step S21: When the pressure value is not greater than the preset pressure threshold, control the electronic expansion valve to increase the opening degree;

[0069] The preset pressure threshold is the maximum pressure allowed to protect the internal structure of the electronic expansion valve from wear when the opening of the electronic expansion valve increases during the shutdown of the heat pump system.

[0070] When the electronic expansion valve increases its opening, the opening adjustment value can be increased from a preset fixed opening adjustment value, or it can be increased to a target opening adjustment value determined according to the actual operation of the heat pump system, or it can be directly increased to a preset fixed opening.

[0071] In one implementation of this embodiment, the electronic expansion valve is controlled to increase to a first preset opening degree, which is greater than the current opening degree of the electronic expansion valve. In this embodiment, the first preset opening degree is the maximum opening degree of the electronic expansion valve. This is beneficial for protecting the electronic expansion valve while simultaneously increasing the speed at which the system reaches pressure equilibrium after shutdown. In other embodiments, the first preset opening degree may also be a smaller opening degree than the maximum opening degree of the electronic expansion valve.

[0072] In another implementation of this embodiment, the electronic expansion valve is controlled to increase its opening based on the pressure value. This can be achieved by determining an opening adjustment value based on the pressure range in which the pressure value falls, and then controlling the electronic expansion valve to increase its opening by that adjustment value; alternatively, the target opening of the electronic expansion valve can be determined based on the pressure value, and the electronic expansion valve can be controlled to increase to the target opening.

[0073] Step S22: When the pressure value is greater than the preset pressure threshold, control the electronic expansion valve to maintain the current opening.

[0074] When the electronic expansion valve reduces its opening, the opening adjustment value can be a preset fixed opening adjustment value, a target opening adjustment value determined according to the actual operation of the heat pump system, or it can be directly reduced to a preset fixed opening.

[0075] In this embodiment, when the pressure value is not greater than the preset pressure threshold, it indicates that increasing the opening of the electronic expansion valve can relieve pressure without causing wear on the internal structure. In this case, controlling the electronic expansion valve to increase its opening allows for rapid unloading of the system, achieving a pressure balance. When the pressure value is greater than the preset pressure threshold, it indicates that increasing the opening of the electronic expansion valve will cause excessive impact on the internal structure, resulting in wear. In this case, controlling the electronic expansion valve to maintain its current opening for unloading effectively reduces wear caused by the unloading process during shutdown. Therefore, the service life of the electronic expansion valve is effectively improved.

[0076] In other embodiments, when the pressure value is greater than a preset pressure threshold, the electronic expansion valve can also be controlled to reduce the current opening degree.

[0077] Furthermore, in this embodiment, the step of controlling the electronic expansion valve to increase its opening degree according to the pressure value includes: determining the pressure difference between the preset pressure threshold and the pressure value; determining an opening degree adjustment value according to the pressure difference; and controlling the electronic expansion valve to increase its opening degree by the opening degree adjustment value.

[0078] Different pressure differentials correspond to different opening adjustment values. These opening adjustment values ​​can include the adjustment amplitude, adjustment ratio, or adjustment rate. The pressure differential and the opening adjustment value are positively correlated.

[0079] The correspondence between pressure difference and opening adjustment value can be preset, and this correspondence can take the form of a calculation formula, mapping relationship, algorithm model, etc. For example, when the correspondence is a calculation formula, the opening adjustment value can be calculated by substituting the pressure difference into the formula. Alternatively, when the correspondence is a mapping table, the result obtained by looking up the pressure difference in the table can be used as the opening adjustment value.

[0080] In this embodiment, the opening adjustment value determined by the pressure difference between the preset pressure threshold and the pressure value is used to control the electronic expansion valve to increase its opening. This helps to ensure that the electronic expansion valve can achieve rapid pressure balance during the opening process while further reducing wear on its internal structure.

[0081] Furthermore, the correspondence between the pressure difference and the opening adjustment value can be fixed at one. Alternatively, more than one correspondence can be preset between the pressure difference and the opening adjustment value. A target correspondence is determined from these multiple correspondences based on the actual operation of the heat pump system, and the opening adjustment value corresponding to the pressure difference is determined based on the target correspondence. For example, the change in pressure difference across the electronic expansion valve before and after the heat pump system shutdown and the temperature difference between the heat exchanger and the ambient temperature when the heat pump system is shut down can be obtained. The target correspondence is determined based on the change value and the temperature difference; different change values ​​and different temperature differences correspond to different target correspondences. The change value and temperature difference accurately reflect the impact of the overall system pressure change trend on the risk of wear on the internal structure of the electronic expansion valve during the process of increasing the opening degree. Therefore, determining the target correspondence by combining the change value and the temperature difference is beneficial for quickly unloading and achieving pressure balance while further reducing the wear risk of the electronic expansion valve.

[0082] Furthermore, based on any of the above embodiments, another embodiment of the control method for the electronic expansion valve of this application is proposed. In this embodiment, reference is made to... Figure 5 Step S10 includes:

[0083] Step S11: When a shutdown command for the heat pump system is received, the pressure values ​​at both ends of the electronic expansion valve are detected to obtain a first pressure value and a second pressure value.

[0084] The first pressure value is detected by the first pressure sensor, and the second pressure value is detected by the second pressure sensor.

[0085] When a shutdown command is received from the heat pump system, the compressor is controlled to stop. While the compressor is in a stopped state, the first pressure value and the second pressure value are detected.

[0086] In this embodiment, the pressure values ​​at both ends of the electronic expansion valve can accurately reflect the impact on its internal structure after the opening of the electronic expansion valve increases. Therefore, after the heat pump system stops, the opening of the electronic expansion valve can be adjusted according to the pressure values ​​at both ends of the electronic expansion valve, which is conducive to rapid pressure balance and further reduces wear on the electronic expansion valve.

[0087] Furthermore, in this embodiment, referring to Figure 5 Step S20 includes:

[0088] Step S201: Determine the maximum pressure value among the first pressure value and the second pressure value;

[0089] When the first pressure value is greater than the second pressure value, the first pressure value is the maximum pressure value.

[0090] When the first pressure value is less than the second pressure value, the second pressure value is the maximum pressure value.

[0091] Step S202: Control the opening degree of the electronic expansion valve according to the maximum pressure value so that the heat pump system reaches a pressure balance state.

[0092] When the maximum pressure is not greater than the preset pressure threshold, the electronic expansion valve is controlled to increase its opening; when the maximum pressure is greater than the preset pressure threshold, the electronic expansion valve is controlled to maintain its current opening.

[0093] In this embodiment, the pressure at the high-pressure end of the electronic expansion valve can accurately reflect the maximum risk of wear on its internal structure. Therefore, controlling the opening of the electronic expansion valve according to the maximum pressure at both ends of the electronic expansion valve is beneficial to ensure that no matter how the refrigerant flow direction changes before shutdown, the opening of the electronic expansion valve can be accurately adjusted to meet the wear risk after shutdown, thereby achieving system pressure balance and reducing the wear risk of the electronic expansion valve.

[0094] In other embodiments, the average of the first pressure value and the second pressure value can be determined as the average pressure, and the opening of the electronic expansion valve can be controlled according to the average.

[0095] Furthermore, based on any of the above embodiments, another embodiment of the control method for the electronic expansion valve of this application is proposed. In this embodiment, step S10 includes: when a shutdown command of the heat pump system is received, obtaining the shutdown duration of the heat pump system; when the shutdown duration reaches a first preset duration, detecting the pressure value related to the operation of the electronic expansion valve in the heat pump system.

[0096] The first preset duration can be a fixed duration that is set in advance, for example, the first preset duration can be 30 seconds. The first preset duration can also be a duration determined based on the conditions before the heat pump system is shut down, for example, the first preset duration can be determined based on the operating frequency of the compressor before the heat pump system is shut down.

[0097] When the downtime has not reached the first preset time, the electronic expansion valve is controlled to maintain the current opening.

[0098] In this embodiment, the pressure value is detected after the heat pump system has been shut down for a period of time. This is suitable for adjusting the opening of the electronic expansion valve based on the pressure value, which helps to improve the accuracy of the pressure value in characterizing the wear risk of the electronic expansion valve, thereby further reducing the wear of the electronic expansion valve and enabling the system to reach a pressure balance state.

[0099] Furthermore, based on any of the above embodiments, another optional embodiment of the control method for the electronic expansion valve of this application is proposed. In this embodiment, after step S20, the method further includes: obtaining the shutdown duration of the heat pump system; when the shutdown duration reaches a second preset duration, controlling the electronic expansion valve to reset to a second preset opening degree.

[0100] The second preset duration is longer than the first preset duration mentioned above.

[0101] The second preset duration can be a fixed duration that is set in advance. For example, the first preset duration can be 120 seconds. The second preset duration can also be determined according to the actual situation of the heat pump system, for example, based on the pressure value and the pressure change value after the opening of the electronic expansion valve is increased.

[0102] The second preset duration represents the pressure balance state reached after the heat pump system is shut down.

[0103] The second preset opening degree is a pre-set fixed opening degree. The second preset opening degree is 30% to 70% of the maximum opening degree. In this embodiment, when the heat pump system is shut down for 30 seconds, the pressure value is detected. If the detected pressure value is not greater than a preset pressure threshold, the electronic expansion valve is controlled to increase to the maximum opening degree of 480pls; if the detected pressure value is greater than the preset pressure threshold, the electronic expansion valve is controlled to maintain the current opening degree. After the electronic expansion valve increases its opening degree or maintains its current opening degree, when the shutdown time reaches 120 seconds, the electronic expansion valve is controlled to reset to 220pls.

[0104] In this embodiment, when the shutdown time reaches the second preset time, the electronic expansion valve is reset to the second preset opening degree. This helps to avoid the impact of sudden pressure changes on the internal structure of the electronic expansion valve when the heat pump system is restarted, further reducing the wear of the electronic expansion valve and improving its service life.

[0105] In this embodiment, the first preset opening degree is greater than the second preset opening degree.

[0106] Furthermore, this embodiment of the invention also proposes a storage medium storing a control program for an electronic expansion valve. When the control program for the electronic expansion valve is executed by a processor, it implements the relevant steps of any embodiment of the above-described electronic expansion valve control method.

[0107] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0108] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0109] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, heat pump system, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0110] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A control method for an electronic expansion valve, characterized in that, The control method for the electronic expansion valve includes the following steps: When a shutdown command is received from the heat pump system, the pressure values ​​at both ends of the electronic expansion valve in the heat pump system are detected to obtain a first pressure value and a second pressure value. Determine the maximum pressure value between the first pressure value and the second pressure value; The opening degree of the electronic expansion valve is controlled according to the maximum pressure value so that the heat pump system reaches a pressure balance state. The step of controlling the opening of the electronic expansion valve according to the maximum pressure value to achieve a pressure balance state in the heat pump system includes: When the maximum pressure value is not greater than the preset pressure threshold, the electronic expansion valve is controlled to increase its opening. When the maximum pressure value is greater than the preset pressure threshold, the electronic expansion valve is controlled to maintain the current opening.

2. The control method for the electronic expansion valve as described in claim 1, characterized in that, The step of controlling the electronic expansion valve to increase its opening includes: Control the electronic expansion valve to increase to a first preset opening degree, the preset opening degree being greater than the current opening degree of the electronic expansion valve; or, The electronic expansion valve is controlled to increase its opening based on the maximum pressure value.

3. The control method for the electronic expansion valve as described in claim 2, characterized in that, The step of controlling the electronic expansion valve to increase its opening based on the maximum pressure value includes: Determine the pressure difference between the preset pressure threshold and the maximum pressure value; The opening adjustment value is determined based on the pressure difference value; The electronic expansion valve is controlled to increase its opening by the opening adjustment value.

4. The control method for the electronic expansion valve as described in any one of claims 1 to 3, characterized in that, The step of detecting the pressure values ​​at both ends of the electronic expansion valve in the heat pump system to obtain a first pressure value and a second pressure value when a shutdown command of the heat pump system is received includes: When a shutdown command for the heat pump system is received, the shutdown duration of the heat pump system is obtained; When the downtime reaches the first preset time, the pressure values ​​at both ends of the electronic expansion valve in the heat pump system are detected to obtain the first pressure value and the second pressure value.

5. The control method for the electronic expansion valve as described in any one of claims 1 to 3, characterized in that, After the step of controlling the opening of the electronic expansion valve according to the maximum pressure value to make the heat pump system reach a pressure balance state, the method further includes: Obtain the downtime of the heat pump system; When the downtime reaches the second preset time, the electronic expansion valve is controlled to reset to the second preset opening degree.

6. A heat pump system, characterized in that, The heat pump system includes: Electronic expansion valve; A pressure detection module is disposed at at least one end of the electronic expansion valve; A control device is provided, wherein the electronic expansion valve and the pressure detection module are both connected to the control device. The control device includes: a memory, a processor, and a control program for the electronic expansion valve stored in the memory and executable on the processor. When the control program for the electronic expansion valve is executed by the processor, it implements the steps of the control method for the electronic expansion valve as described in any one of claims 1 to 5.

7. The heat pump system as described in claim 6, characterized in that, The pressure detection module includes a first pressure sensor and a second pressure sensor respectively located at both ends of the electronic expansion valve, and both the first pressure sensor and the second pressure sensor are connected to the control device.

8. A storage medium, characterized in that, The storage medium stores a control program for an electronic expansion valve, which, when executed by a processor, implements the steps of the control method for an electronic expansion valve as described in any one of claims 1 to 5.

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