A method and apparatus for self-tuning the regulating parameters of an electronic expansion valve based on a heat pump system

Abstract

This invention discloses a method and apparatus for self-tuning the adjustment parameters of an electronic expansion valve based on a heat pump system. It detects and acquires various parameters collected by the heat pump system in the current environment, and then uses these parameters to determine the PI control parameters of the PI controller operating in that environment. The system operates under these acquired PI control parameters, and by judging the effectiveness of the PI control parameters, it tunes the PI control parameters. Whether the automatic parameter tuning occurs during initial equipment startup or during equipment operation, it can achieve optimal PI control parameters, ensuring the equipment operates at its best. This also reduces the number of objects that operators need to adjust for PI control parameters, allowing even inexperienced operators to debug the equipment.

Description

Technical Field

[0001] This invention relates to the field of home appliance application equipment technology, and in particular to a method and device for self-tuning the adjustment parameters of an electronic expansion valve based on a heat pump system. Background Technology

[0002] In a heat pump control system, the electronic expansion valve is used to control and regulate the flow of refrigerant, thereby ensuring accurate control of the evaporation temperature. It is one of the four core components directly affecting the operation of the entire system.

[0003] Currently, in most heat pump systems, the control of the electronic expansion valve generally uses suction superheat control. This involves setting a target superheat value, and then adjusting the output steps of the expansion valve based on the difference between the actual superheat and the target superheat, so that the actual superheat value continuously approaches the target superheat value to achieve the corresponding control effect. In this adjustment process, there are generally pure proportional control (P control), proportional control (PI control), or proportional derivative control (PID control), which directly reads the corresponding steps from a two-dimensional table of superheat difference for adjustment.

[0004] All of the above control schemes require professional personnel to manually adjust the parameters of the newly matched electronic control system and participate in the operating condition test. This traditional adjustment scheme requires the adjustment personnel to have a certain understanding of the control system. If general laboratory testers do not understand the electronic control parameters, they will not be able to perform parameter tuning. This tuning method is generally inefficient, and improper adjustment can also cause oscillations and affect the operation of the system. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for self-tuning the adjustment parameters of an electronic expansion valve based on a heat pump system, aiming to solve the technical problems in the background art.

[0006] To achieve the above objectives, the technical solutions of the present invention are as follows:

[0007] As one aspect of this application, a method for self-tuning the regulating parameters of an electronic expansion valve based on a heat pump system is provided, comprising:

[0008] The system detects and acquires various parameters collected by the heat pump system in the current environment, and sets PI control parameters for the PI controller operating in this environment based on these parameters. The PI control parameters include setting a proportional coefficient value, setting an integral time coefficient, and setting a sampling time.

[0009] The system operates under the obtained PI control parameters, and the PI control parameters are tuned by judging the quality of the control effect of the set of PI control parameters.

[0010] The PI control parameters are tuned in the order of sampling time, proportional coefficient, and integral time coefficient.

[0011] The set sampling time is the larger of the actual sampling time and the set sampling time;

[0012] The proportional coefficient is set according to a multiple of the set proportional coefficient, with the oscillation amplitude of the superheat regulation of the electronic expansion valve as the judgment benchmark.

[0013] The integral time coefficient is tuned according to a multiple of the set integral time coefficient.

[0014] Compared with the prior art, the self-tuning method for regulating parameters of an electronic expansion valve based on a heat pump system proposed in this application can achieve optimal PI control parameters whether the parameters are automatically tuned during the initial startup of the equipment or during the operation of the equipment, so that the equipment is in the best operating state. At the same time, it can reduce the number of objects that operators need to adjust for PI control parameters, and can also debug the equipment for less experienced operators.

[0015] Furthermore, various parameters collected by the heat pump system in the current environment are detected and acquired. Based on these parameters, the PI control parameters of the PI controller operating in this environment are determined. These PI control parameters include setting a proportional gain, setting an integral time factor, and setting a sampling time. Specifically, they include:

[0016] Detect and acquire the current ambient temperature and inlet water temperature collected by the heat pump system in the current environment;

[0017] The system sets a minimum exhaust temperature and obtains the current exhaust temperature based on the current ambient temperature and inlet water temperature. It then compares the current exhaust temperature with the set minimum exhaust temperature and collects the intake temperature of the electronic expansion valve and the outdoor coil temperature when the current exhaust temperature is greater than the set minimum exhaust temperature.

[0018] The current superheat of the electronic expansion valve is obtained by measuring the intake temperature of the electronic expansion valve and the outdoor coil temperature.

[0019] The PI control parameters of the PI controller operating under the current environment are obtained based on the current superheat of the electronic expansion valve. The PI control parameters include setting the proportional coefficient value, setting the integral time coefficient, and setting the sampling time.

[0020] In this application, the step of operating under the obtained PI control parameters and tuning the PI control parameters by judging the quality of the control effect of the set of PI control parameters specifically includes:

[0021] A sampling time tuning unit is constructed. The first judgment result is obtained by comparing the time interval between the change and stabilization of the superheat of the electronic expansion valve when the opening of the electronic expansion valve is adjusted with the set sampling time. The PI controller tunes the PI control parameters according to the first judgment result.

[0022] A proportional coefficient tuning unit is constructed. The second judgment result is obtained by comparing the fluctuation deviation amplitude of the superheat of the electronic expansion valve from change to stability with the set fluctuation deviation value. The PI controller is then tuned according to the second judgment result.

[0023] An integral time coefficient tuning unit is constructed. Based on the current sampling time and the current proportional coefficient, a third judgment result is obtained. The PI controller tunes the PI control parameters based on the third judgment result.

[0024] Furthermore, a sampling time tuning unit is constructed. A first judgment result is obtained by comparing the time interval between the change and stabilization of the superheat of the electronic expansion valve during adjustment of its opening with a set sampling time. The PI controller then tunes the PI control parameters based on this first judgment result, specifically including:

[0025] When the opening of the electronic expansion valve is adjusted, the time interval from the initial change to the stabilization of the superheat of the electronic expansion valve is obtained by timing.

[0026] Determine whether the interval is greater than the set sampling time, where the set sampling time is an interval threshold; if so, set the PI controller to adjust the parameters according to the larger value in the set sampling time.

[0027] Furthermore, a proportional gain tuning unit is constructed. This unit compares the fluctuation deviation amplitude of the electronic expansion valve's superheat from change to stability with a set fluctuation deviation value to obtain a second judgment result. The PI controller then tunes the PI control parameters based on this second judgment result, specifically including:

[0028] When the opening of the electronic expansion valve is adjusted, the fluctuation amplitude of the superheat of the electronic expansion valve from change to stability is obtained, and the maximum deviation value is calculated based on the fluctuation amplitude.

[0029] Determine if the maximum deviation value is greater than the set deviation value;

[0030] If so, set the PI controller to be tuned according to half of the set proportional coefficient value;

[0031] If not, set the PI controller to be adjusted by doubling the set proportional coefficient value.

[0032] Furthermore, an integral time coefficient tuning unit is constructed to obtain a third judgment result based on the current sampling time and the current proportional coefficient. The PI controller then tunes the PI control parameters based on this third judgment result, specifically including:

[0033] After the electronic expansion valve adjusts its opening, when the superheat of the electronic expansion valve changes until it stabilizes, the current sampling time and the current proportional coefficient when the superheat of the electronic expansion valve is stable are obtained.

[0034] The set integral time coefficient is used in the calculation based on the current sampling time and the current scaling factor.

[0035] By setting the detection cycle for the overheat fluctuation of the electronic expansion valve and adjusting the set integral time coefficient, when the fluctuation of the current electronic expansion valve overheat is detected to be eliminated, the current integral time coefficient is recorded and used in the parameter tuning of the PI controller.

[0036] Furthermore, given the current sampling time and the current proportional coefficient, the set integral proportional coefficient is reduced and applied to the PI controller to regulate the overheat of the electronic expansion valve.

[0037] With the current integral proportional coefficient participating in the calculation, the superheat adjustment cycle of the electronic expansion valve is set. Every first set cycle, the integral proportional coefficient is reduced and participates in the superheat adjustment control of the PI controller until the superheat of the electronic expansion valve is detected to have periodic fluctuations, and the current integral proportional coefficient is recorded.

[0038] After the superheat of the electronic expansion valve fluctuates periodically, the current integral proportional coefficient is increased every first set period and participates in the superheat regulation control of the PI controller until the superheat of the electronic expansion valve is eliminated, and the current integral time coefficient is recorded.

[0039] As a second aspect of this application, a self-tuning device for regulating parameters of an electronic expansion valve based on a heat pump system is provided, comprising:

[0040] Electronic expansion valve;

[0041] A PI controller is connected to an electronic expansion valve. The PI controller is used to detect and acquire various parameters collected by the heat pump system in the current environment. Based on these parameters, the PI controller operates under these PI control parameters. The PI control parameters are then tuned by judging the effectiveness of the PI control parameters.

[0042] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0043] Figure 1 This is a flowchart of the self-tuning method for the adjustment parameters of the electronic expansion valve based on the heat pump system in this embodiment;

[0044] Figure 2 This is the device execution block diagram indicated in the self-tuning method for the electronic expansion valve adjustment parameters based on the heat pump system in this embodiment;

[0045] Figure 3 This is a flowchart of step S2 of the self-tuning method for adjusting the parameters of the electronic expansion valve based on the heat pump system in this embodiment. Detailed Implementation

[0046] To better illustrate the present invention, the invention will now be described in further detail with reference to the accompanying drawings.

[0047] It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.

[0048] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0049] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0050] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0051] Based on the description in the background art, the technical problem actually solved by the present invention is how to constrain the parameter configuration of the device and how to achieve automatic adjustment of the PI control parameters.

[0052] On the one hand, as a preferred embodiment of this application, such as Figure 1 and Figure 2 As shown, a method for self-tuning the regulating parameters of an electronic expansion valve based on a heat pump system is provided, including the following steps:

[0053] Step S1: Detect and acquire various parameters collected by the heat pump system in the current environment, and determine the PI control parameters of the PI controller operating in this environment based on these parameters. The PI control parameters include setting the proportional coefficient value, setting the integral time coefficient, and setting the sampling time. Operate under the acquired PI control parameters, and adjust the PI control parameters by judging the quality of the control effect of the set of PI control parameters.

[0054] In step S1, the electronic expansion valve performs parameter self-tuning actions, including during the initial startup of the equipment and during operation.

[0055] When the device is first started, the PI control parameters are tuned by setting the proportional coefficient, the integral time coefficient, and the sampling time when there is no reference object. Specifically, when the device is powered on for the first time / started, the PI control parameters are set to a relatively large proportional coefficient value by default, the integral implementation coefficient is set to 0, and a relatively large sampling time value is set at the same time.

[0056] When the device is running, the PI control parameters are the values ​​after running tuning. The corresponding PI control parameters refer to the current PI control parameter values ​​as the self-tuning reference, that is, as the set proportional coefficient value, set integral time coefficient and set sampling time in the PI control parameters.

[0057] Specifically, in order to achieve automatic parameter tuning of the exhaust temperature range and ensure safe operation of the equipment, in step S1, the current ambient temperature and inlet water temperature collected by the heat pump system in the current environment are detected and acquired.

[0058] The system sets a minimum exhaust temperature and obtains the current exhaust temperature based on the current ambient temperature and inlet water temperature. It then compares the current exhaust temperature with the set minimum exhaust temperature and collects the intake temperature of the electronic expansion valve and the outdoor coil temperature when the current exhaust temperature is greater than the set minimum exhaust temperature.

[0059] The superheat of the electronic expansion valve is obtained by measuring the intake temperature of the electronic expansion valve and the outdoor coil temperature; the PI control parameters of the PI controller operating under the current environment are obtained based on the current superheat of the electronic expansion valve, the PI control parameters including the set proportional coefficient value, the set integral time coefficient, and the set sampling time.

[0060] The system acquires the ambient temperature T1 of the current equipment and the inlet water temperature T2 of the heat pump system. By setting a minimum exhaust temperature value Tset, the system controls the exhaust temperature during equipment operation to be no lower than the minimum exhaust temperature value Tset. When the exhaust temperature during equipment operation is lower than the set minimum exhaust temperature value Tset, the opening of the electronic expansion valve is reduced to adjust the exhaust temperature until it exceeds the minimum exhaust temperature value Tset, thus entering the next temperature control step (superheat regulation control). In this embodiment, the setting method of the minimum exhaust temperature value Tset is a commonly used method in the prior art. The value of the minimum exhaust temperature value Tset can be determined by a two-dimensional lookup table. That is, the setting value of the minimum exhaust temperature value Tset is determined according to the inlet water temperature T2 and the ambient temperature T1 according to the two-dimensional table agreed upon in the prior art. Different Tsets are selected according to different equipment operating conditions and water temperatures to ensure that the equipment in the heat pump system can operate safely whether it is the first start-up (cold start) or the restart after operation (hot start), reducing the occurrence of condensate liquid conditions.

[0061] In summary, after ensuring the exhaust temperature meets the requirements, the suction temperature T3 and outdoor coil temperature T2 in the heat pump system are collected. The suction superheat of the current equipment in heating mode is calculated and obtained. The suction superheat setpoint corresponding to the current ambient temperature (obtainable through a two-dimensional lookup table) is used as the input deviation value of the PI controller. Based on the input deviation value of the PI controller and the initial operation / power-on status of the equipment, the PI control parameters are set to the maximum value of the sampling time value corresponding to the current input deviation value, the integral time coefficient is 0, and the maximum value of the corresponding proportional coefficient value. Similarly, when the equipment is in operation, the PI control parameters are the sampling time value, proportional coefficient value, and integral time coefficient during stable operation of the current equipment.

[0062] Therefore, in this embodiment, as Figure 2As shown, the PI control parameters are tuned in the order of sampling time, proportional coefficient, and integral time coefficient. The sampling time is the larger of the actual sampling time and the set sampling time. The proportional coefficient is tuned according to a multiple of the set proportional coefficient, with the oscillation amplitude of the superheat regulation of the electronic expansion valve as the judgment benchmark. The integral time coefficient is tuned according to a multiple of the set integral time coefficient.

[0063] In step S2, as Figure 3 As shown, the system operates under the obtained PI control parameters. By judging the effectiveness of the PI control parameters, the PI control parameters are tuned, specifically including:

[0064] Step S21: Construct a sampling time tuning unit. By comparing the time interval between the change and stabilization of the superheat of the electronic expansion valve when the opening of the electronic expansion valve is adjusted with the set sampling time, a first judgment result is obtained. The PI controller tunes the PI control parameters according to the first judgment result.

[0065] When the opening of the electronic expansion valve is adjusted, the time interval from the initial change to the stabilization of the superheat of the electronic expansion valve is obtained by timing; it is determined whether the interval time is greater than the set sampling time, wherein the set sampling time is an interval threshold; if so, the PI controller is set to adjust the parameters according to the larger value in the set sampling time.

[0066] First, regarding the setting of the sampling time, for example, the sampling time is defined as the interval [a, b]. If the interval is greater than the set sampling time, that is, the interval exceeds the limit b of the set sampling time, the PI controller will adjust the parameters according to the larger value IbI in the set sampling time.

[0067] When the equipment is started for the first time, after the electronic expansion valve is significantly adjusted, timing begins and the actual superheat value before adjustment is saved. After the superheat stabilizes after adjustment, the time when the superheat of the electronic expansion valve stabilizes is recorded. The difference between the recorded start time and the actual superheat temperature response time for the heat pump system is obtained, which is used as the sampling time value. If the sampling time value is greater than the set sampling time value, the set sampling time value is selected as the tuning parameter to prevent the superheat adjustment cycle from being too long.

[0068] When adjusting the opening of the electronic expansion valve during equipment operation, after the electronic expansion valve significantly adjusts its opening, the PI control parameters are configured to the parameters of the electronic expansion valve when it was running stably before the adjustment, which serve as the sampling time set above. After the electronic expansion valve significantly adjusts its opening, timing begins, and the actual superheat value before adjustment is saved. After the superheat value stabilizes after adjustment, the time when the superheat value of the electronic expansion valve stabilizes is recorded. The difference between the recorded start time and the actual superheat temperature response time for the heat pump system is obtained, which is used as the sampling time value. If it is determined that the sampling time value is greater than the set sampling time value, the set sampling time value is selected as the tuning parameter to prevent the superheat adjustment cycle from being too long.

[0069] Step S22: Construct a proportional coefficient tuning unit. By comparing the fluctuation deviation amplitude of the superheat of the electronic expansion valve from change to stability with the set fluctuation deviation value, a second judgment result is obtained. The PI controller tunes the PI control parameters according to the second judgment result.

[0070] When the opening of the electronic expansion valve is adjusted, the fluctuation amplitude of the superheat of the electronic expansion valve from change to stability is obtained, and the maximum deviation value is calculated based on the fluctuation amplitude.

[0071] Determine if the maximum deviation value is greater than the set deviation value;

[0072] If so, set the PI controller to be tuned according to half of the set proportional coefficient value;

[0073] If not, set the PI controller to be adjusted by doubling the set proportional coefficient value.

[0074] When the equipment is running for the first time and the frequency is stable, the superheat adjustment will inevitably have periodic oscillations according to the set proportional coefficient. In this embodiment, two oscillation cycles are selected and the maximum deviation value in the two oscillation cycles is recorded. In the electronic expansion valve, this is the maximum difference between the set superheat and the actual superheat. If the maximum deviation value is greater than the set deviation value (e.g., the set deviation value is set to 3°C), the PI controller is adjusted according to half of the set proportional coefficient value. Conversely, if the deviation value is less than half, the PI controller is adjusted according to double the set proportional coefficient value. Two more oscillation cycles are then taken, and the maximum deviation value is compared again until the maximum deviation value is appropriate.

[0075] Similarly, after the electronic expansion valve adjusts the opening of the equipment during operation, and the equipment reaches a stable frequency state, if the equipment operates according to the original proportional coefficient, the superheat adjustment will inevitably have periodic oscillations. In this embodiment, two oscillation cycles are selected, and the maximum deviation value in the two oscillation cycles is recorded. In the electronic expansion valve, this is the maximum difference between the set superheat and the actual superheat. If the maximum deviation value is greater than the set deviation value (e.g., the set deviation value is set to 3°C), the PI controller is adjusted according to half of the set proportional coefficient value. Conversely, if the deviation value is less than half, the PI controller is adjusted according to double the set proportional coefficient value. Two more oscillation cycles are then taken, and the maximum deviation value is compared again until the maximum deviation value is appropriate.

[0076] Step S23: Construct an integral time coefficient tuning unit, obtain the third judgment result based on the current sampling time and the current proportional coefficient, and tune the PI control parameters based on the third judgment result.

[0077] After the electronic expansion valve adjusts its opening, when the superheat of the electronic expansion valve changes until it stabilizes, the current sampling time and the current proportional coefficient when the superheat of the electronic expansion valve is stable are obtained.

[0078] The set integral time coefficient is used in the calculation based on the current sampling time and the current scaling factor.

[0079] By setting the detection cycle for the overheat fluctuation of the electronic expansion valve and adjusting the set integral time coefficient, when the fluctuation of the current electronic expansion valve overheat is detected to be eliminated, the current integral time coefficient is recorded and used in the parameter tuning of the PI controller.

[0080] Given the current sampling time and the current proportional coefficient, the set integral proportional coefficient is reduced and applied to the PI controller to adjust the overheat of the electronic expansion valve.

[0081] With the current integral proportional coefficient participating in the calculation, the superheat adjustment cycle of the electronic expansion valve is set. Every first set cycle, the integral proportional coefficient is reduced and participates in the superheat adjustment control of the PI controller until the superheat of the electronic expansion valve is detected to have periodic fluctuations, and the current integral proportional coefficient is recorded.

[0082] After the superheat of the electronic expansion valve fluctuates periodically, the current integral proportional coefficient is increased every first set period and participates in the superheat regulation control of the PI controller until the superheat of the electronic expansion valve is eliminated, and the current integral time coefficient is recorded.

[0083] When the equipment is first started or is running, as mentioned above, after the proportional coefficient is determined, the actual superheat of the electronic expansion valve is still in a periodic oscillation state. Therefore, an integral time coefficient is introduced. At the same time, with the sampling time determined, a larger integral time coefficient is introduced to participate in the calculation, while the determined proportional coefficient value is reduced. Under this integral action, the integral time is reduced by half every five cycles, and the superheat fluctuation range is detected in each cycle until periodic fluctuations occur. At this time, the integral time coefficient is gradually increased every five cycles until the fluctuations are eliminated. The integral time coefficient Ti at this time is recorded. The actual automatically tuned integral time coefficient is configured as Ti*150%.

[0084] As a second aspect of this application, a self-tuning device for regulating parameters of an electronic expansion valve based on a heat pump system is provided, comprising:

[0085] Electronic expansion valve; PI controller, the PI controller is connected to the electronic expansion valve, the PI controller is used to detect and acquire various parameters collected by the heat pump system in the current environment, and to set PI control parameters for the PI controller operating in the environment according to the various parameters, and to operate under the acquired PI control parameters. By judging the quality of the control effect of the set of PI control parameters, the PI control parameters are tuned.

[0086] This embodiment presents a method and apparatus for self-tuning the adjustment parameters of an electronic expansion valve based on a heat pump system. Whether it is automatic parameter tuning during the initial startup of the equipment or automatic tuning during equipment operation, it can achieve the optimal configuration of PI control parameters, so that the equipment is in the best operating state. At the same time, it can reduce the number of objects that operators need to adjust for PI control parameters, and even inexperienced operators can debug the equipment.

[0087] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A method for self-tuning the regulating parameters of an electronic expansion valve based on a heat pump system, characterized in that, include: The system detects and acquires various parameters collected by the heat pump system in the current environment, and obtains the PI control parameters of the PI controller operating in this environment based on these parameters. The PI control parameters include setting the proportional coefficient value, setting the integral time coefficient, and setting the sampling time. The system operates under the obtained PI control parameters, and the PI control parameters are tuned by judging the quality of the control effect of the set of PI control parameters. The PI control parameters are tuned in the order of sampling time, proportional coefficient, and integral time coefficient. The set sampling time is the larger of the actual sampling time and the set sampling time; The proportional coefficient is set according to a multiple of the set proportional coefficient, with the oscillation amplitude of the superheat regulation of the electronic expansion valve as the judgment benchmark. The integral time coefficient is tuned according to a multiple of the set integral time coefficient; The system detects and acquires various parameters collected by the heat pump system in the current environment, and obtains the PI control parameters of the PI controller operating in this environment based on these parameters. The PI control parameters include a set proportional coefficient value, a set integral time coefficient, and a set sampling time, specifically including: Detect and acquire the current ambient temperature and inlet water temperature collected by the heat pump system in the current environment; The system sets a minimum exhaust temperature and obtains the current exhaust temperature based on the current ambient temperature and inlet water temperature. It then compares the current exhaust temperature with the set minimum exhaust temperature and collects the intake temperature of the electronic expansion valve and the outdoor coil temperature when the current exhaust temperature is greater than the set minimum exhaust temperature. The current superheat of the electronic expansion valve is obtained by measuring the intake temperature of the electronic expansion valve and the outdoor coil temperature. The PI control parameters of the PI controller operating under the current environment are obtained based on the current superheat of the electronic expansion valve. The PI control parameters include setting the proportional coefficient value, setting the integral time coefficient, and setting the sampling time. The process of operating under the obtained PI control parameters, and then tuning the PI control parameters by judging the effectiveness of the PI control parameters, specifically includes: A sampling time tuning unit is constructed. The first judgment result is obtained by comparing the time interval between the change and stabilization of the superheat of the electronic expansion valve when the opening of the electronic expansion valve is adjusted with the set sampling time. The PI controller tunes the PI control parameters according to the first judgment result. A proportional coefficient tuning unit is constructed. The second judgment result is obtained by comparing the fluctuation deviation amplitude of the superheat of the electronic expansion valve from change to stability with the set fluctuation deviation value. The PI controller is then tuned according to the second judgment result. An integral time coefficient tuning unit is constructed. Based on the current sampling time and the current proportional coefficient, a third judgment result is obtained. The PI controller tunes the PI control parameters based on the third judgment result.

2. The self-tuning method for adjusting the regulating parameters of an electronic expansion valve based on a heat pump system according to claim 1, characterized in that, The sampling time tuning unit obtains a first judgment result by comparing the time interval between the change and stabilization of the superheat of the electronic expansion valve when the opening of the electronic expansion valve is adjusted with a set sampling time. The PI controller tunes the PI control parameters based on the first judgment result, specifically including: When the opening of the electronic expansion valve is adjusted, the time interval from the initial change to the stabilization of the superheat of the electronic expansion valve is obtained by timing. Determine whether the interval is greater than a set sampling time, wherein the set sampling time is an interval threshold; If so, the PI controller is set to adjust its parameters according to the larger value in the set sampling time.

3. The self-tuning method for adjusting the regulating parameters of an electronic expansion valve based on a heat pump system according to claim 1, characterized in that, The proportional coefficient tuning unit determines a second judgment result by comparing the fluctuation deviation amplitude of the superheat of the electronic expansion valve from change to stability with a set fluctuation deviation value. The PI controller then tunes the PI control parameters based on this second judgment result, specifically including: When the opening of the electronic expansion valve is adjusted, the fluctuation amplitude of the superheat of the electronic expansion valve from change to stability is obtained, and the maximum deviation value is calculated based on the fluctuation amplitude. Determine if the maximum deviation value is greater than the set deviation value; If so, set the PI controller to be tuned according to half of the set proportional coefficient value; If not, set the PI controller to be tuned to twice the set proportional coefficient value.

4. The self-tuning method for adjusting the regulating parameters of an electronic expansion valve based on a heat pump system according to claim 1, characterized in that, The step of constructing the integral time coefficient tuning unit, which obtains a third judgment result based on the current sampling time and the current proportional coefficient, and then tunes the PI control parameters based on the third judgment result, specifically includes: After the electronic expansion valve adjusts its opening, when the superheat of the electronic expansion valve changes until it stabilizes, the current sampling time and the current proportional coefficient when the superheat of the electronic expansion valve is stable are obtained. The set integral time coefficient is used in the calculation based on the current sampling time and the current scaling factor. By setting the detection cycle for the overheat fluctuation of the electronic expansion valve and adjusting the set integral time coefficient, when the fluctuation of the current electronic expansion valve overheat is detected to be eliminated, the current integral time coefficient is recorded and used in the parameter tuning of the PI controller.

5. The self-tuning method for adjusting the regulating parameters of an electronic expansion valve based on a heat pump system according to claim 4, characterized in that, Specifically, it includes: Given the current sampling time and the current proportional coefficient, the set integral proportional coefficient is reduced and applied to the PI controller to adjust the overheat of the electronic expansion valve. With the current integral proportional coefficient participating in the calculation, the superheat adjustment cycle of the electronic expansion valve is set. Every first set cycle, the integral proportional coefficient is reduced and participates in the superheat adjustment control of the PI controller until the superheat of the electronic expansion valve is detected to have periodic fluctuations, and the current integral proportional coefficient is recorded. After the superheat of the electronic expansion valve fluctuates periodically, the current integral proportional coefficient is increased every first set period and participates in the superheat regulation control of the PI controller until the superheat fluctuation of the electronic expansion valve is eliminated, and the current integral time coefficient is recorded.

6. A self-tuning device for adjusting parameters of an electronic expansion valve based on a heat pump system, characterized in that, include: Electronic expansion valve; A PI controller is connected to an electronic expansion valve. The PI controller is used to detect and acquire various parameters collected by the heat pump system in the current environment, obtain the PI control parameters of the PI controller operating in this environment based on the various parameters, and operate under the obtained PI control parameters. By judging the quality of the control effect of the set of PI control parameters, the PI control parameters are tuned. The PI control parameters include setting the proportional coefficient value, setting the integral time coefficient, and setting the sampling time; The PI control parameters are tuned in the order of sampling time, proportional coefficient, and integral time coefficient. The set sampling time is the larger of the actual sampling time and the set sampling time; The proportional coefficient is set according to a multiple of the set proportional coefficient, with the oscillation amplitude of the superheat regulation of the electronic expansion valve as the judgment benchmark. The integral time coefficient is tuned according to a multiple of the set integral time coefficient; The process of detecting and acquiring various parameters collected by the heat pump system in the current environment, and obtaining the PI control parameters of the PI controller operating in this environment based on these parameters, specifically includes: Detect and acquire the current ambient temperature and inlet water temperature collected by the heat pump system in the current environment; The system sets a minimum exhaust temperature and obtains the current exhaust temperature based on the current ambient temperature and inlet water temperature. It then compares the current exhaust temperature with the set minimum exhaust temperature and collects the intake temperature of the electronic expansion valve and the outdoor coil temperature when the current exhaust temperature is greater than the set minimum exhaust temperature. The current superheat of the electronic expansion valve is obtained by measuring the intake temperature of the electronic expansion valve and the outdoor coil temperature. The PI control parameters of the PI controller operating under the current environment are obtained based on the current superheat of the electronic expansion valve. The process of operating under the obtained PI control parameters and tuning the PI control parameters by judging the effectiveness of the PI control parameters specifically includes: A sampling time tuning unit is constructed. The first judgment result is obtained by comparing the time interval between the change and stabilization of the superheat of the electronic expansion valve when the opening of the electronic expansion valve is adjusted with the set sampling time. The PI controller tunes the PI control parameters according to the first judgment result. A proportional coefficient tuning unit is constructed. The second judgment result is obtained by comparing the fluctuation deviation amplitude of the superheat of the electronic expansion valve from change to stability with the set fluctuation deviation value. The PI controller is then tuned according to the second judgment result. An integral time coefficient tuning unit is constructed. Based on the current sampling time and the current proportional coefficient, a third judgment result is obtained. The PI controller tunes the PI control parameters based on the third judgment result.

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