Detection system and method for electronic expansion valve

Abstract

The invention discloses a detection system and method for an electronic expansion valve, and relates to the technical field of valve detection. Comprising a data acquisition module, a data processing module, a fluctuation judgment module, a stability verification module and a mark classification module, wherein the data acquisition module is used for acquiring detection data of a standard electronic expansion valve and a to-be-detected electronic expansion valve in a standard environment; according to the technical scheme, an existing electronic expansion valve detection mode is changed, whether the electronic expansion valve can be applied or not is detected to the adjustment precision of the electronic expansion valve, detection is carried out in a standard environment, and in cooperation with correction analysis of the standard electronic expansion valve, the influence of liquid flowing in the electronic expansion valve opening adjustment process is reduced; according to the electronic expansion valve opening degree adjusting method, accurate liquid flow rate data can be calculated, the accurate liquid flow rate data are analyzed, the opening degree adjusting precision of the electronic expansion valve is directly reflected, related technicians can conveniently know the use precision of the electronic expansion valve, and the electronic expansion valve opening degree adjusting method has good use prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of valve detection, and in particular to a detection system and method for an electronic expansion valve. Background Art

[0002] Electronic expansion valve is a throttling element that can control the refrigerant flow rate entering the refrigeration unit according to a preset program. In some occasions where the load changes drastically or the operating conditions are wide, traditional throttling elements (such as capillary tubes, thermal expansion valves, etc.) can no longer meet the requirements of comfort and energy saving. Electronic expansion valves combined with compressor variable capacity technology have been increasingly widely used.

[0003] As a new type of control element, the electronic expansion valve has become an important part of the intelligentization of the refrigeration system. It is also an important means and guarantee for the real optimization of the refrigeration system. It is used in more and more fields.

[0004] New energy vehicles refer to vehicles that use unconventional automotive fuels as their power source and integrate advanced technologies in vehicle power control and drive to form vehicles with advanced technical principles, new technologies, and new structures. The requirements for electronic expansion valves used in new energy vehicles are relatively high. The requirements for electronic expansion valves are that they are sensitive and responsive, and can work stably for a long time. In order to ensure that the electronic expansion valves can operate safely and stably, people have invented electronic expansion valve detection systems and methods.

[0005] The existing authorization announcement number is CN106404371B, and the invention patent named "Electronic Expansion Valve Detection Method and Device, Air Conditioning System" records that it includes: when receiving a detection instruction, controlling the air conditioner prototype to start and operate under preset operating conditions; controlling the opening of the electronic expansion valve to be adjusted to a preset first opening value nP, and operating for a first preset time; obtaining the first exhaust pressure value of the compressor and the first temperature change of the electronic expansion valve before and after the electronic expansion valve opening is adjusted; when the first exhaust pressure value is less than the first preset pressure threshold, and the first temperature change is greater than the first preset temperature threshold, judging that the electronic expansion valve is normally opened. The present invention also discloses an electronic expansion valve detection device and an air conditioning system. The present invention realizes automatic detection of the air conditioner electronic expansion valve, avoiding the low detection efficiency of manual detection.

[0006] However, based on the above content and in combination with the prior art, the central idea of ​​the solution recorded in the above patent is to install the electronic expansion valve in the air-conditioning system, then operate the air-conditioning system normally, obtain the operating status of the air-conditioning system, and determine whether the electronic expansion valve is working normally through the operating status data of the air-conditioning system, thereby realizing the detection of the electronic expansion valve.

[0007] However, the above scheme has great defects in actual use. It only installs the electronic expansion valve in the air-conditioning system to determine whether it can be used normally. With the development of science and technology, the qualification rate of electronic expansion valves produced nowadays is above 90%, and basically all of them can be used. However, many electronic expansion valves are affected by the external environment and the impact of refrigerant when the opening is adjusted during use, which will cause the accuracy of the opening adjustment to change, and the accuracy of the electronic expansion valve will continue to decline. The existing electronic expansion valve detection system cannot realize this aspect of detection and does not meet people's use requirements. For this reason, we have developed a detection system and method for electronic expansion valves. Summary of the invention

[0008] 1. Technical issues to be resolved

[0009] In view of the deficiencies in the prior art, the present invention provides a detection system and method for an electronic expansion valve, which changes the existing detection method of the electronic expansion valve, and upgrades the existing basic detection of whether the electronic expansion valve can be used to the detection of the adjustment accuracy of the electronic expansion valve. The detection is performed in a standard environment, and in conjunction with the calibration analysis of the standard electronic expansion valve, the influence of liquid flow during the opening adjustment process of the electronic expansion valve is reduced, so that more accurate liquid flow rate data can be calculated. By analyzing the more accurate liquid flow rate data, the opening adjustment accuracy of the electronic expansion valve can be directly reflected, so that relevant technical personnel can understand the use accuracy of the electronic expansion valve, so that the electronic expansion valve can be used more reasonably, with good use effect and good application prospects.

[0010] (II) Technical solution

[0011] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0012] A detection system for an electronic expansion valve includes a data acquisition module, a data processing module, a fluctuation evaluation module, a stability verification module and a marking classification module:

[0013] Data acquisition module: used to obtain the test data of the standard electronic expansion valve and the electronic expansion valve to be tested under the standard environment. The standard environment is a test room with a temperature of 20°C, a humidity of 50% and an ambient air pressure of 100kPa. The test data are the mass data of the liquid flowing out of the electronic expansion valve at N different openings after a time T, the time data used by the electronic expansion valve to adjust the opening, and the parameter data of the electronic expansion valve;

[0014] Data processing module: used to calculate the opening adjustment error value according to the electronic expansion valve parameter data and the liquid quality data of the standard electronic expansion valve, and then adjust the liquid quality data of the electronic expansion valve to be tested based on the calculated opening adjustment error value;

[0015] Fluctuation evaluation module: used to obtain the adjusted liquid quality data of the electronic expansion valve to be tested, and calculate the corresponding mass flow data, and calculate the standard degree under N different openings based on the mass flow data, and compare the maximum and minimum values ​​in the standard degree with the standard interval;

[0016] If both the maximum value and the minimum value are within the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is qualified, and a qualified signal is issued;

[0017] If the maximum value or the minimum value is outside the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is unqualified, and an unqualified warning is issued;

[0018] Stability verification module: used to continuously perform K limit opening tests on the electronic expansion valve to be tested when receiving a qualified signal, and then re-test the electronic expansion valve to be tested under a standard environment, further analyze and calculate the re-tested data, obtain the limit standard degrees under N different openings, compare the maximum and minimum values ​​in the limit standard degrees with the standard interval, and make a second judgment on whether the electronic expansion valve to be tested is qualified;

[0019] Marking and classification module: It is used to analyze the limit standard degrees under N different openings after the secondary judgment of the electronic expansion valve is qualified, calculate the fluctuation value of the electronic expansion valve to be tested, and calculate the standard difference between the standard average value and the limit standard average value, calculate the product stability value according to the fluctuation value and the standard difference of the electronic expansion valve to be tested, and mark and classify the electronic expansion valve to be tested according to the range to which the product stability value belongs.

[0020] Furthermore, the steps of testing the standard electronic expansion valve and the electronic expansion valve to be tested under standard environment are as follows:

[0021] S1. The adjustment of the electronic expansion valve is divided into Q steps in total. N values ​​are randomly selected between 1 and Q, and the selected values ​​are arranged in order from small to large to obtain a test sorting table;

[0022] S2, set the first position of the test sorting table to the opening data of the electronic expansion valve after adjustment, the time for adjusting the opening and maintaining the opening is T, obtain the time data T1 used for adjusting the opening of the electronic expansion valve, the mass data Mb of the liquid flowing out of the standard electronic expansion valve at the standard time T, and the mass data Mj of the liquid flowing out of the electronic expansion valve to be tested at the standard time T, delete the first position of the test sorting table after the test and rearrange it;

[0023] S3. Repeat step S2 and perform N-1 tests in the order of the test ranking table to obtain N groups of test data.

[0024] Furthermore, the formula for calculating the opening adjustment error value based on the electronic expansion valve parameter data and the liquid quality data of the standard electronic expansion valve is as follows:

[0025]

[0026] Wherein, Error is the opening adjustment error value, ρ is the density of the test liquid, v is the outlet specific volume of the test liquid, h is the valve needle lift of the electronic expansion valve, α is the cone angle of the valve needle of the electronic expansion valve, d is the diameter of the valve needle of the electronic expansion valve, P1 is the pressure of the test liquid at the inlet of the electronic expansion valve, P2 is the pressure of the test liquid at the inlet of the electronic expansion valve, and T1 is the time taken for the electronic expansion valve to adjust from the initial opening to the first opening.

[0027] Furthermore, the formula for adjusting the liquid quality data of the electronic expansion valve to be tested is:

[0028] Mjt=Mj-Error

[0029] Wherein, Mjt is the adjusted liquid mass data of the electronic expansion valve to be tested, and Mj is the liquid mass data of the electronic expansion valve to be tested.

[0030] Furthermore, the corresponding mass flow data formula is calculated as follows:

[0031]

[0032] Where, Qmj is the calculated mass flow data;

[0033] The formula for calculating standardization based on mass flow data is as follows:

[0034]

[0035] Wherein, Sta is the standard degree, the standard interval is (1-A, 1+A), A is the set fluctuation data, 0.03≤A≤0.05.

[0036] Furthermore, the steps of the limit opening test are as follows:

[0037] Set the liquid supply equipment to supply liquid at a constant flow rate, adjust the opening of the electronic expansion valve to the maximum value, and maintain the maximum opening for 3 minutes;

[0038] Start the controller of the electronic expansion valve and close the electronic expansion valve as quickly as possible;

[0039] When the inlet pressure of the electronic expansion valve reaches the set pressure, the controller of the electronic expansion valve is started to open the electronic expansion valve to the maximum opening at the fastest speed.

[0040] Furthermore, the fluctuation value formula of the electronic expansion valve to be tested is calculated based on N limit standards as follows:

[0041]

[0042] Where, Flu is the fluctuation value of the electronic expansion valve to be tested during the first test, JXSta i is the limit standard degree under the i-th opening after the limit opening test, JXSta j It is the limit standard degree at the jth opening after the limit opening test.

[0043] Furthermore, the formula for calculating the standard deviation between the standard deviation average and the limit standard deviation average is as follows:

[0044]

[0045] Where Diff is the standard deviation between the standard deviation mean and the limit standard deviation mean, Sta j is the standard degree under the j-th opening, JXSta j It is the limit standard degree at the jth opening after the limit opening test.

[0046] Furthermore, the formula for calculating the product stability value according to the fluctuation value and the standard difference of the electronic expansion valve to be tested is as follows:

[0047] Stab=1-Diff×Dxs-Flu×Fxs

[0048] Wherein, Stab is the product stability value, Dxs is the weight coefficient corresponding to the standard deviation, Fxs is the weight coefficient corresponding to the fluctuation value, 0<Fxs<Dxs, Fxs+Dxs=1;

[0049] The steps to mark and classify the electronic expansion valve to be tested according to the range of product stability values ​​are as follows:

[0050] Compare the product stability value Stab with the preset value JPZ, extract the electronic expansion valve with Stab ≥ JPZ, and mark it as a standard electronic expansion valve;

[0051] Compare the product stability value Stab with the preset lower limit value HGZ, extract the electronic expansion valves with Stab < HGZ, and mark them as unqualified electronic expansion valves;

[0052] If HGZ<Stab<JPZ, compare Diff×Dxs and Flu×Fxs in the electronic expansion valve of Stab<JPZ. If Diff×Dxs is less than Flu×Fxs, mark it as an electronic expansion valve with limited opening accuracy. If Diff×Dxs≥Flu×Fxs, mark it as an electronic expansion valve with limited life.

[0053] Furthermore, a method for detecting an electronic expansion valve comprises the following steps:

[0054] Acquire test data of a standard electronic expansion valve and an electronic expansion valve to be tested under a standard environment, wherein the standard environment is a test room with a temperature of 20°C, a humidity of 50%, and an ambient pressure of 100 kPa, and the test data are the mass data of liquid flowing out of the electronic expansion valve at N different openings after a time T, the time data used for the electronic expansion valve to adjust the opening, and the parameter data of the electronic expansion valve;

[0055] Calculating an opening adjustment error value according to the electronic expansion valve parameter data and the liquid quality data of a standard electronic expansion valve, and then adjusting the liquid quality data of the electronic expansion valve to be tested based on the calculated opening adjustment error value;

[0056] Calculate the corresponding mass flow data according to the adjusted liquid mass data of the electronic expansion valve to be tested, and calculate the standard degrees at N different openings based on the mass flow data, and compare the maximum and minimum values ​​in the standard degrees with the standard interval;

[0057] If both the maximum value and the minimum value are within the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is qualified, and a qualified signal is issued;

[0058] If the maximum value or the minimum value is outside the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is unqualified, and an unqualified warning is issued;

[0059] When receiving a qualified signal, the electronic expansion valve to be tested is tested for K consecutive limit opening tests, and then the electronic expansion valve to be tested is tested again under a standard environment. The data of the retest is further analyzed and calculated to obtain the limit standard degrees under N different openings, and the maximum and minimum values ​​in the limit standard degrees are compared with the standard interval to determine whether the electronic expansion valve to be tested is qualified for the second time.

[0060] After the secondary judgment that the electronic expansion valve is qualified, the limit standard degrees under N different openings are analyzed, the fluctuation value of the electronic expansion valve to be tested is calculated, and the standard degree difference between the standard degree average value and the limit standard degree average value is calculated. The product stability value is calculated based on the fluctuation value and the standard degree difference of the electronic expansion valve to be tested, and the electronic expansion valve to be tested is marked and classified according to the range to which the product stability value belongs.

[0061] (III) Beneficial effects

[0062] The present invention provides a detection system and method for an electronic expansion valve, which has the following beneficial effects:

[0063] 1. The present invention records a detection system for an electronic expansion valve, which changes the existing detection method of the electronic expansion valve. It upgrades the existing detection method from the basic detection of whether the electronic expansion valve can be used to the detection of the adjustment accuracy of the electronic expansion valve. It is located in a standard environment for detection, and cooperates with the calibration analysis of the standard electronic expansion valve to reduce the influence of liquid flow during the opening adjustment of the electronic expansion valve, so that more accurate liquid flow rate data can be calculated. By analyzing the more accurate liquid flow rate data, the opening adjustment accuracy of the electronic expansion valve can be directly reflected, so that relevant technical personnel can understand the use accuracy of the electronic expansion valve, so that the electronic expansion valve can be used more reasonably, the use effect is good, and it has a good application prospect.

[0064] 2. The present invention provides a detection system and method for an electronic expansion valve, which uses the water hammer effect to impact the electronic expansion valve after the accuracy test of the electronic expansion valve, and then performs the accuracy test of the electronic expansion valve again to judge the accuracy change and accuracy fluctuation of the electronic expansion valve, so as to intuitively analyze the stability and service life of the electronic expansion valve, thereby enabling accurate judgment of the quality, applicability and accuracy of the electronic expansion valve, helping relevant personnel to classify the electronic expansion valves, and directly reflecting the defects of the produced electronic expansion valves, so as to facilitate technical personnel to make improvements, with good use effect and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a flow chart of a detection system of an electronic expansion valve of the present invention;

[0066] Figure 2 A schematic diagram of an electronic expansion valve testing device in a detection system of an electronic expansion valve according to the present invention;

[0067] Figure 3 The present invention is a partial internal structure diagram of an electronic expansion valve in a detection system of an electronic expansion valve. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] Research reasons

[0070] The existing electronic expansion valve detection system directly installs the electronic expansion valve in the air-conditioning system when in use, and then operates the air-conditioning system normally, obtains the operating status of the air-conditioning system, and determines whether the electronic expansion valve is working normally through the operating status data of the air-conditioning system, thereby realizing the detection of the electronic expansion valve.

[0071] However, the above scheme has great defects in actual use. The above scheme only installs the electronic expansion valve in the air-conditioning system, and then monitors the relevant parameters, and judges whether the electronic expansion valve can be used normally through other parameters. This method uses other equipment to reflect the situation of the electronic expansion valve, which will be interfered by the operation of other equipment. Therefore, the collected data is inaccurate. In addition, the use of the electronic expansion valve is indirectly judged by analyzing and judging the relevant data, which is not accurate enough and has a certain lag. Therefore, this method can only monitor whether the electronic expansion valve can be used normally, but cannot reflect the performance of the electronic expansion valve.

[0072] With the development of science and technology, the qualification rate of electronic expansion valves produced nowadays is above 90%, and they can basically be used. However, many electronic expansion valves are affected by the external environment and the impact of refrigerant when the opening is adjusted during use, which will cause the accuracy of the opening adjustment to change, which will cause the accuracy of the electronic expansion valve to continue to decline. The existing electronic expansion valve detection system cannot realize this aspect of detection and does not meet people's usage requirements.

[0073] Design ideas

[0074] Most of the existing systems simply judge the basic functions of the electronic expansion valve and test whether the electronic expansion valve can adjust the opening. However, there is basically no test on the performance of the electronic expansion valve (most of them adopt the method of sampling comprehensive test to replace the quality of the entire batch of electronic expansion valves. Since the comprehensive test time is relatively long, the comprehensive test method is not adopted). Therefore, it is impossible to intuitively understand the real quality of the electronic expansion valve.

[0075] Therefore, during the research and development process, the initial idea was to design a solution that could simply detect the accuracy of the electronic expansion valve and achieve adjustment of the accuracy of the electronic expansion valve. Therefore, a set of devices for detecting the electronic expansion valve was set up to achieve the measurement of the electronic expansion valve.

[0076] However, in actual use, it was found that during the opening adjustment process, especially from closed to the maximum opening state, there was a large difference between the flow rate of the liquid and the flow rate after the opening adjustment. This process would have a great impact on the test results, resulting in inaccurate test results that did not meet people's usage requirements.

[0077] Therefore, in the middle of the research and development, we changed our thinking and added a standard electronic expansion valve for comparison. Through comparative analysis, we reduced the impact of liquid flow during the opening adjustment process, making the collected liquid flow velocity more accurate, and thus collecting more standard data.

[0078] However, in actual use, it is found that since the opening of the electronic expansion valve is frequently adjusted, the hydraulic pressure at the inlet of the electronic expansion valve is always fluctuating, which often impacts the electronic expansion valve and reduces the accuracy of the electronic expansion valve. Without corresponding testing, it is completely unknown whether the electronic expansion valve can withstand the test of impact.

[0079] Therefore, in the later stage of research and development, we fully combined the previous solutions, carried out the limit opening test, and then measured again to compare the impact of the limit opening test on the electronic expansion valve, so as to fully understand the quality of the electronic expansion valve.

[0080] Study plan

[0081] A detection system for an electronic expansion valve includes a data acquisition module, a data processing module, a fluctuation evaluation module, a stability verification module and a marking classification module:

[0082] The detection system of the electronic expansion valve consists of two parts: hardware and software;

[0083] The hardware part mainly includes servers and Figure 2 The electronic expansion valve test device shown;

[0084] The software part is the various modules recorded in this system, which realize the collection and analysis of electronic expansion valve test data through the cooperation of various modules.

[0085] Data collection

[0086] In order to accurately judge the accuracy of the electronic expansion valve, the test data related to the electronic expansion valve must be analyzed. In order to obtain accurate test data related to the electronic expansion valve, an electronic expansion valve testing device is developed to realize the detection of the electronic expansion valve. The test data of the electronic expansion valve testing device and the parameter data of the electronic expansion valve are obtained based on the data acquisition module. The data acquisition module is connected to the quality inspection database and can directly obtain the parameter data of the electronic expansion valve.

[0087] The data acquisition module acquires the test data of the standard electronic expansion valve and the electronic expansion valve to be tested under a standard environment. The standard environment is a test room with a temperature of 20°C, a humidity of 50%, and an ambient pressure of 100 kPa. The test data are the mass data of the liquid flowing out of the electronic expansion valve at N different openings after a time T, the time data used by the electronic expansion valve to adjust the opening, and the parameter data of the electronic expansion valve;

[0088] The liquid mass data flowing out of the electronic expansion valve at N different openings after a time T is N groups of liquid mass data, each group of liquid mass data is the mass of liquid flowing out of the electronic expansion valve for a time period of T, and the time period T includes the time used to adjust the opening of the electronic expansion valve.

[0089] The steps for testing the standard electronic expansion valve and the electronic expansion valve to be tested under standard conditions are as follows:

[0090] S1. The adjustment of the electronic expansion valve is divided into Q steps in total. N values ​​are randomly selected between 1 and Q, and the selected values ​​are arranged in order from small to large to obtain a test sorting table;

[0091] S2, set the first position of the test sorting table to the opening data of the electronic expansion valve after adjustment, the time for adjusting the opening and maintaining the opening is T, obtain the time data T1 used for adjusting the opening of the electronic expansion valve, the mass data Mb of the liquid flowing out of the standard electronic expansion valve at the standard time T, and the mass data Mj of the liquid flowing out of the electronic expansion valve to be tested at the standard time T, delete the first position of the test sorting table after the test and rearrange it;

[0092] S3. Repeat step S2 and perform N-1 tests in the order of the test ranking table to obtain N groups of test data.

[0093] For example, the first adjustment is from 0 to 60 steps, and it is kept for 20 seconds after adjustment to collect corresponding data. Then it is adjusted to 100 steps, and it is kept for 20 seconds after adjustment to collect corresponding data. The detection and analysis are carried out in sequence until N times of analysis, so as to realize accurate detection of the accuracy of the electronic expansion valve.

[0094] During the above test, compare the set adjustment opening time and the adjustment opening time of the electronic expansion valve to be tested to see if they are the same. If the time difference ratio is within 3%, the electronic expansion valve to be tested is judged to be qualified and the above test is performed again. Otherwise, it is judged to be unqualified and no test is required.

[0095] The time difference ratio = | set adjustment opening time - the adjustment opening time of the electronic expansion valve to be detected | / set adjustment opening time.

[0096] Since most of the existing electronic expansion valves have been calibrated during production, the above time comparison step can be removed. If they have not been calibrated, the above time comparison step is required.

[0097] The set adjustment opening time can also be adjusted to the standard electronic expansion valve adjustment opening time, but the standard electronic expansion valve adjustment opening time has a certain error, which is relatively small, but still exists. Therefore, the set adjustment opening time is adopted, and the set adjustment opening time is calculated according to the number of steps required for the opening adjustment.

[0098] The use of a standard electronic expansion valve can also play the role of a detection test device. By comparing the real-time collected standard electronic expansion valve data with the historical test data and checking the difference in the test data, it can be determined whether the test device needs to be calibrated. It is convenient to use and can effectively avoid the situation where the data of the electronic expansion valve to be tested is non-standard due to errors in the test device, and the use effect is good.

[0099] Data analysis

[0100] After collecting the relevant data of the electronic expansion valve to be tested, it is necessary to further process and analyze the collected data to improve the accuracy of data collection. In addition, the required test data is extracted from it to facilitate the subsequent further analysis of the electronic expansion valve. This process is based on the data processing module.

[0101] Data processing module: calculating an opening adjustment error value according to the electronic expansion valve parameter data and the liquid quality data of the standard electronic expansion valve, and then adjusting the liquid quality data of the electronic expansion valve to be tested based on the calculated opening adjustment error value;

[0102] The formula for calculating the opening adjustment error value based on the electronic expansion valve parameter data and the liquid quality data of the standard electronic expansion valve is as follows:

[0103]

[0104] Wherein, Error is the opening adjustment error value, ρ is the density of the test liquid, v is the outlet specific volume of the test liquid, h is the valve needle lift of the electronic expansion valve (which can be calculated according to the number of adjustment steps), α is the cone angle of the valve needle of the electronic expansion valve, d is the diameter of the valve needle of the electronic expansion valve, P1 is the pressure of the test liquid at the inlet of the electronic expansion valve, P2 is the pressure of the test liquid at the inlet of the electronic expansion valve, and T1 is the time taken for the electronic expansion valve to adjust from the initial opening to the first opening.

[0105] This is the constant flow rate with the opening set under ideal conditions. Since the test is carried out under standard conditions, external environmental interference is eliminated. The data detected by the standard electronic expansion valve is this data.

[0106] The standard electronic expansion valve is an electronic expansion valve that has been fully tested and has an error of less than 0.5%, so it can be regarded as standard data.

[0107] The above formula is the flow quality data of the electronic expansion valve under standard conditions over a period of time. It is combined with the relevant test data of the standard electronic expansion valve to analyze the time required to adjust the opening, and calculate the flow quality within the adjustment opening time, remove this part of the interference, and obtain more accurate test data, which can improve the accuracy of subsequent electronic expansion valve analysis.

[0108] The formula for adjusting the liquid quality data of the electronic expansion valve to be tested is:

[0109] Mjt=Mj-Error

[0110] Wherein, Mjt is the adjusted liquid mass data of the electronic expansion valve to be tested, and Mj is the liquid mass data of the electronic expansion valve to be tested.

[0111] For example, T is 20 seconds, the time T1 for adjusting 60 steps is 1 second, the liquid mass data of the electronic expansion valve to be tested is 1.19 kg, the opening adjustment error value is about 0.04 kg, and the liquid mass data of the electronic expansion valve to be tested after adjustment is 1.15 kg.

[0112] By removing the mass data of the liquid flowing through the electronic expansion valve to be tested for a long time when the opening is adjusted, the mass data of the liquid in the electronic expansion valve to be tested in the time period T-T1 can be detected.

[0113] Accuracy judgment

[0114] After obtaining N groups of liquid quality data of the electronic expansion valve to be tested in the T-T1 time period, in order to further determine whether the accuracy has been adjusted in place, it is necessary to further calculate the mass flow rate of the electronic expansion valve to be tested, and this process is based on the fluctuation judgment module.

[0115] The fluctuation evaluation module obtains the adjusted liquid mass data of the electronic expansion valve to be tested, and calculates the corresponding mass flow data, and calculates the standard degrees under N different openings based on the mass flow data, and compares the maximum and minimum values ​​in the standard degrees with the standard interval;

[0116] The formula for calculating the corresponding mass flow data is as follows:

[0117]

[0118] Where, Qmj is the calculated mass flow data;

[0119] For example: Combining the data of the above example, the calculated Qmj=1.15 / 19≈0.06kg / s.

[0120] The formula for calculating standardization based on mass flow data is as follows:

[0121]

[0122] Wherein, Sta is the standard degree, the standard interval is (1-A, 1+A), A is the set fluctuation data, 0.03≤A≤0.05.

[0123] The comparison between the standard degree and the standard range can directly reflect the difference between the electronic expansion valve to be tested and the set electronic expansion valve.

[0124] If both the maximum value and the minimum value are within the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is qualified, and a qualified signal is issued;

[0125] There are N groups of standard data. The maximum and minimum values ​​in the N groups of standard data are compared with the standard range. If both are within the standard range, it means that the electronic expansion valve is qualified.

[0126] The smaller the value of A is, the higher the detection accuracy is. Under normal circumstances, A can be set to 0.05.

[0127] If the maximum value or the minimum value is outside the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is unqualified, and an unqualified warning is issued;

[0128] When the maximum or minimum value is outside the standard range, it means that the opening adjustment accuracy is not standard;

[0129] At this time, there are two ways. One is to directly judge it as unqualified, and the other is to judge the standard data before and after the unqualified data, and then compare it with the standard interval. If there is a set of data outside the standard interval, it is judged as unqualified. If the before and after data are both within the standard interval, there may be a data collection error. At this time, retest.

[0130] The present invention records an electronic expansion valve detection system, which changes the existing electronic expansion valve detection method, and improves the existing detection of whether the electronic expansion valve can be used from the basic detection to the detection of the adjustment accuracy of the electronic expansion valve. The detection is carried out in a standard environment, and cooperates with the calibration analysis of the standard electronic expansion valve to reduce the influence of liquid flow during the opening adjustment of the electronic expansion valve, so that more accurate liquid flow rate data can be calculated. By analyzing the more accurate liquid flow rate data, the opening adjustment accuracy of the electronic expansion valve can be directly reflected, so that relevant technical personnel can understand the use accuracy of the electronic expansion valve, so that the electronic expansion valve can be used more reasonably, the use effect is good, and it has a good application prospect.

[0131] Stability test

[0132] After the accuracy test, a stability test is required to understand the stability performance of the electronic expansion valve to be tested. In order to facilitate the test and shorten the process, a plan to use the same set of devices for the limit opening test is studied, which is specifically implemented through the supervision of the stability verification module.

[0133] Because electronic expansion valves are used in new energy vehicles, which may involve braking and other scenarios during operation, liquids may often impact the valve body of the electronic expansion valve. Therefore, during the inspection process, the electronic expansion valve must be tested for stability.

[0134] When receiving a qualified signal, the stability verification module continuously performs K limit opening tests on the electronic expansion valve to be tested, and then re-tests the electronic expansion valve to be tested under a standard environment. The re-tested data is further analyzed and calculated to obtain the limit standard degrees under N different openings, and the maximum and minimum values ​​in the limit standard degrees are compared with the standard interval to determine whether the electronic expansion valve to be tested is qualified.

[0135] The steps of the limit opening test are as follows:

[0136] Set the liquid supply equipment to supply liquid at a constant flow rate, adjust the opening of the electronic expansion valve to the maximum value, and maintain the maximum opening for 3 minutes;

[0137] Start the controller of the electronic expansion valve and close the electronic expansion valve as quickly as possible;

[0138] When the inlet pressure of the electronic expansion valve reaches the set pressure (to avoid excessive pressure damaging the connection), start the controller of the electronic expansion valve and open the electronic expansion valve to the maximum opening at the fastest speed.

[0139] 15≤K≤30. After K times of limit opening tests, when the electronic expansion valve to be tested has production error or assembly error, its error will become larger. Therefore, it can be directly reflected through the corresponding data at this time.

[0140] The limit opening test uses the water hammer effect to impact the electronic expansion valve, causing the electronic expansion valve to vibrate greatly, which can amplify the error.

[0141] Electronic expansion valve classification

[0142] After the electronic expansion valve has passed the limit opening test, it needs to be analyzed and calculated again to evaluate the overall quality of the electronic expansion valve. This process is based on the marking classification module.

[0143] After the marking and classification module makes a secondary judgment that the electronic expansion valve is qualified, the limit standard degrees under N different openings are analyzed, the fluctuation value of the electronic expansion valve to be tested is calculated, and the standard degree difference between the standard degree average value and the limit standard degree average value is calculated. The product stability value is calculated based on the fluctuation value and the standard degree difference of the electronic expansion valve to be tested, and the electronic expansion valve to be tested is marked and classified according to the range to which the product stability value belongs.

[0144] The formula for calculating the fluctuation value of the electronic expansion valve to be tested based on N limit standards is as follows:

[0145]

[0146] Where, Flu is the fluctuation value of the electronic expansion valve to be tested during the first test, JXSta i is the limit standard degree under the i-th opening after the limit opening test, JXSta j It is the limit standard degree at the jth opening after the limit opening test.

[0147] The fluctuation value can directly reflect the fluctuation of the data after the limit opening test, and directly reflect the stability of the electronic expansion valve detection accuracy through the fluctuation.

[0148] The formula for calculating the standard deviation between the standard mean and the limit standard mean is as follows:

[0149]

[0150] Where Diff is the standard deviation between the standard deviation mean and the limit standard deviation mean, Sta j is the standard degree under the j-th opening, JXSta j It is the limit standard degree at the jth opening after the limit opening test.

[0151] The standard deviation can directly reflect the decrease in accuracy after the limit opening test. Through this test, the production quality and service life can be roughly judged.

[0152] The formula for calculating the product stability value based on the fluctuation value and standard difference of the electronic expansion valve to be tested is as follows:

[0153] Stab=1-Diff×Dxs-Flu×Fxs

[0154] Wherein, Stab is the product stability value, Dxs is the weight coefficient corresponding to the standard deviation, Fxs is the weight coefficient corresponding to the fluctuation value, 0<Fxs<Dxs, Fxs+Dxs=1;

[0155] The steps to mark and classify the electronic expansion valve to be tested according to the range of product stability values ​​are as follows:

[0156] Compare the product stability value Stab with the preset value JPZ, extract the electronic expansion valve with Stab ≥ JPZ, and mark it as a standard electronic expansion valve;

[0157] This type of electronic expansion valve can be used in most scenarios.

[0158] Compare the product stability value Stab with the preset lower limit value HGZ, extract the electronic expansion valves with Stab < HGZ, and mark them as unqualified electronic expansion valves;

[0159] In this case, the accuracy difference varies greatly and the accuracy of the opening adjustment fluctuates greatly. The electronic expansion valve in this case is not suitable for scenes with large fluctuations and high accuracy.

[0160] If HGZ<Stab<JPZ, then compare Diff×Dxs and Flu×Fxs in the electronic expansion valve with Stab<JPZ. If Diff×Dxs is less than Flu×Fxs, then mark it as an electronic expansion valve with limited opening accuracy.

[0161] The electronic expansion valve in this case can be used in scenarios where the opening adjustment accuracy is not high.

[0162] If Diff×Dxs≥Flu×Fxs, it is marked as a life-limited electronic expansion valve, which is used in scenarios where frequent maintenance and replacement are required.

[0163] The weight coefficient is determined by the coefficient of variation method, which is a method of weighting each indicator according to the degree of variation between the current value of each evaluation indicator and the target value. If the numerical difference of an indicator is large, it can clearly distinguish the evaluated objects, indicating that the indicator has rich discrimination information, and thus the indicator should be given a larger weight. On the contrary, if the numerical difference of each evaluated object on a certain indicator is small, then the ability of this indicator to distinguish the evaluation objects is weak, and thus the indicator should be given a smaller weight. This method directly uses the information contained in each indicator and obtains the weight of the indicator through calculation, so it is objective.

[0164] The present invention provides a detection system and method for an electronic expansion valve, which utilizes the water hammer effect to impact the electronic expansion valve after the accuracy test of the electronic expansion valve, and then performs the accuracy test of the electronic expansion valve again to judge the accuracy change and accuracy fluctuation of the electronic expansion valve, so as to intuitively analyze the stability and service life of the electronic expansion valve, thereby enabling accurate judgment of the quality, applicability and accuracy of the electronic expansion valve, helping relevant personnel to classify the electronic expansion valve, and directly reflecting the defects of the produced electronic expansion valves, so as to facilitate technical personnel to make improvements, and has good use effect and good application prospects.

[0165] A method for detecting an electronic expansion valve comprises the following steps:

[0166] Acquire test data of a standard electronic expansion valve and an electronic expansion valve to be tested under a standard environment, wherein the standard environment is a test room with a temperature of 20°C, a humidity of 50%, and an ambient pressure of 100 kPa, and the test data are the mass data of liquid flowing out of the electronic expansion valve at N different openings after a time T, the time data used for the electronic expansion valve to adjust the opening, and the parameter data of the electronic expansion valve;

[0167] Calculating an opening adjustment error value according to the electronic expansion valve parameter data and the liquid quality data of a standard electronic expansion valve, and then adjusting the liquid quality data of the electronic expansion valve to be tested based on the calculated opening adjustment error value;

[0168] Calculate the corresponding mass flow data according to the adjusted liquid mass data of the electronic expansion valve to be tested, and calculate the standard degrees at N different openings based on the mass flow data, and compare the maximum and minimum values ​​in the standard degrees with the standard interval;

[0169] If both the maximum value and the minimum value are within the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is qualified, and a qualified signal is issued;

[0170] If the maximum value or the minimum value is outside the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is unqualified, and an unqualified warning is issued;

[0171] When receiving a qualified signal, the electronic expansion valve to be tested is tested for K consecutive limit opening tests, and then the electronic expansion valve to be tested is tested again under a standard environment. The data of the retest is further analyzed and calculated to obtain the limit standard degrees under N different openings, and the maximum and minimum values ​​in the limit standard degrees are compared with the standard interval to determine whether the electronic expansion valve to be tested is qualified for the second time.

[0172] After the secondary judgment that the electronic expansion valve is qualified, the limit standard degrees under N different openings are analyzed, the fluctuation value of the electronic expansion valve to be tested is calculated, and the standard degree difference between the standard degree average value and the limit standard degree average value is calculated. The product stability value is calculated based on the fluctuation value and the standard degree difference of the electronic expansion valve to be tested, and the electronic expansion valve to be tested is marked and classified according to the range to which the product stability value belongs.

[0173] The electronic expansion valve detected by the above method can operate stably in an environment with large fluctuations, and is particularly suitable for new energy vehicles that are driven by motors, have fast start and stop speeds, and have large impacts of liquid on the electronic expansion valve.

[0174] The above formula is a formula obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0175] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. A person of ordinary skill in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution.

[0176] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0177] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A detection system for an electronic expansion valve, characterized in that: include: Data acquisition module: used to obtain the test data of the standard electronic expansion valve and the electronic expansion valve to be tested under the standard environment. The standard environment is a test room with a temperature of 20°C, a humidity of 50% and an ambient air pressure of 100kPa. The test data are the mass data of the liquid flowing out of the electronic expansion valve at N different openings after a time T, the time data used by the electronic expansion valve to adjust the opening, and the parameter data of the electronic expansion valve; Data processing module: used to calculate the opening adjustment error value according to the electronic expansion valve parameter data and the liquid quality data of the standard electronic expansion valve, and then adjust the liquid quality data of the electronic expansion valve to be tested based on the calculated opening adjustment error value; Fluctuation evaluation module: used to obtain the adjusted liquid quality data of the electronic expansion valve to be tested, and calculate the corresponding mass flow data, and calculate the standard degree under N different openings based on the mass flow data, and compare the maximum and minimum values ​​in the standard degree with the standard interval; If both the maximum value and the minimum value are within the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is qualified, and a qualified signal is issued; If the maximum value or the minimum value is outside the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is unqualified, and an unqualified warning is issued; Stability verification module: used to continuously perform K limit opening tests on the electronic expansion valve to be tested when receiving a qualified signal, and then re-test the electronic expansion valve to be tested under a standard environment, further analyze and calculate the re-tested data, obtain the limit standard degrees under N different openings, compare the maximum and minimum values ​​in the limit standard degrees with the standard interval, and make a second judgment on whether the electronic expansion valve to be tested is qualified; Marking and classification module: It is used to analyze the limit standard degrees under N different openings after the secondary judgment of the electronic expansion valve is qualified, calculate the fluctuation value of the electronic expansion valve to be tested, and calculate the standard difference between the standard average value and the limit standard average value, calculate the product stability value according to the fluctuation value and the standard difference of the electronic expansion valve to be tested, and mark and classify the electronic expansion valve to be tested according to the range to which the product stability value belongs.

2. The electronic expansion valve detection system according to claim 1, characterized in that: The steps for testing the standard electronic expansion valve and the electronic expansion valve to be tested under standard conditions are as follows: S1. The adjustment of the electronic expansion valve is divided into Q steps in total. N values ​​are randomly selected between 1 and Q, and the selected values ​​are arranged in order from small to large to obtain a test sorting table; S2, set the first position of the test sorting table to the opening data of the electronic expansion valve after adjustment, the time for adjusting the opening and maintaining the opening is T, obtain the time data T1 used for adjusting the opening of the electronic expansion valve, the mass data Mb of the liquid flowing out of the standard electronic expansion valve at the standard time T, and the mass data Mj of the liquid flowing out of the electronic expansion valve to be tested at the standard time T, delete the first position of the test sorting table after the test and rearrange it; S3. Repeat step S2 and perform N-1 tests in the order of the test ranking table to obtain N groups of test data.

3. The electronic expansion valve detection system according to claim 2, characterized in that: The formula for calculating the opening adjustment error value based on the electronic expansion valve parameter data and the liquid quality data of the standard electronic expansion valve is as follows: Where, Error is the opening adjustment error value, ρ is the density of the test liquid, v is the outlet specific volume of the test liquid, h is the valve needle lift of the electronic expansion valve, α is the cone angle of the valve needle of the electronic expansion valve, d is the diameter of the valve needle of the electronic expansion valve, P1 is the pressure of the test liquid at the inlet of the electronic expansion valve, and P2 is the pressure of the test liquid at the inlet of the electronic expansion valve.

4. The electronic expansion valve detection system according to claim 3, characterized in that: The formula for adjusting the liquid quality data of the electronic expansion valve to be tested is: Mjt=Mj-Error Wherein, Mjt is the adjusted liquid mass data of the electronic expansion valve to be tested, and Mj is the liquid mass data of the electronic expansion valve to be tested.

5. The electronic expansion valve detection system according to claim 4, characterized in that: The formula for calculating the corresponding mass flow data is as follows: Where, Qmj is the calculated mass flow data; The formula for calculating standardization based on mass flow data is as follows: Wherein, Sta is the standard degree, the standard interval is (1-A, 1+A), A is the set fluctuation data, 0.03≤A≤0.

05.

6. The electronic expansion valve detection system according to claim 5, characterized in that: The steps of the limit opening test are as follows: Set the liquid supply equipment to supply liquid at a constant flow rate, adjust the opening of the electronic expansion valve to the maximum value, and maintain the maximum opening for 3 minutes; Start the controller of the electronic expansion valve and close the electronic expansion valve as quickly as possible; When the inlet pressure of the electronic expansion valve reaches the set pressure, the controller of the electronic expansion valve is started to open the electronic expansion valve to the maximum opening at the fastest speed.

7. The electronic expansion valve detection system according to claim 6, characterized in that: The formula for calculating the fluctuation value of the electronic expansion valve to be tested based on N limit standards is as follows: Where, Flu is the fluctuation value of the electronic expansion valve to be tested during the first test, JXSta i is the limit standard degree under the i-th opening after the limit opening test, JXSta j It is the limit standard degree at the jth opening after the limit opening test.

8. The electronic expansion valve detection system according to claim 7, characterized in that: The formula for calculating the standard deviation between the standard mean and the limit standard mean is as follows: Where Diff is the standard deviation between the standard mean and the limit standard mean, Sta j is the standard degree under the j-th opening, JXSta j It is the limit standard degree at the jth opening after the limit opening test.

9. The electronic expansion valve detection system according to claim 8, characterized in that: The formula for calculating the product stability value based on the fluctuation value and standard difference of the electronic expansion valve to be tested is as follows: Stab=1-Diff×Dxs-Flu×Fxs Wherein, Stab is the product stability value, Dxs is the weight coefficient corresponding to the standard deviation, Fxs is the weight coefficient corresponding to the fluctuation value, 0<Fxs<Dxs, Fxs+Dxs=1; The steps to mark and classify the electronic expansion valve to be tested according to the range of product stability values ​​are as follows: Compare the product stability value Stab with the preset value JPZ, extract the electronic expansion valve with Stab ≥ JPZ, and mark it as a standard electronic expansion valve; Compare the product stability value Stab with the preset lower limit value HGZ, extract the electronic expansion valves with Stab < HGZ, and mark them as unqualified electronic expansion valves; If HGZ<Stab<JPZ, compare Diff×Dxs and Flu×Fxs in the electronic expansion valve of Stab<JPZ. If Diff×Dxs is less than Flu×Fxs, mark it as an electronic expansion valve with limited opening accuracy. If Diff×Dxs≥Flu×Fxs, mark it as an electronic expansion valve with limited life.

10. A method for detecting an electronic expansion valve, using the system according to any one of claims 1 to 9, characterized in that: The steps include: Acquire test data of a standard electronic expansion valve and an electronic expansion valve to be tested under a standard environment, wherein the standard environment is a test room with a temperature of 20°C, a humidity of 50%, and an ambient pressure of 100 kPa, and the test data are the mass data of liquid flowing out of the electronic expansion valve at N different openings after a time T, the time data used for the electronic expansion valve to adjust the opening, and the parameter data of the electronic expansion valve; Calculating an opening adjustment error value according to the electronic expansion valve parameter data and the liquid quality data of a standard electronic expansion valve, and then adjusting the liquid quality data of the electronic expansion valve to be tested based on the calculated opening adjustment error value; Calculate the corresponding mass flow data according to the adjusted liquid mass data of the electronic expansion valve to be tested, and calculate the standard degrees at N different openings based on the mass flow data, and compare the maximum and minimum values ​​in the standard degrees with the standard interval; If both the maximum value and the minimum value are within the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is qualified, and a qualified signal is issued; If the maximum value or the minimum value is outside the standard range, it is determined that the adjustment accuracy of the electronic expansion valve to be tested is unqualified, and an unqualified warning is issued; When receiving a qualified signal, the electronic expansion valve to be tested is tested for K consecutive limit opening tests, and then the electronic expansion valve to be tested is tested again under a standard environment. The data of the retest is further analyzed and calculated to obtain the limit standard degrees under N different openings, and the maximum and minimum values ​​in the limit standard degrees are compared with the standard interval to determine whether the electronic expansion valve to be tested is qualified for the second time. After the secondary judgment that the electronic expansion valve is qualified, the limit standard degrees under N different openings are analyzed, the fluctuation value of the electronic expansion valve to be tested is calculated, and the standard degree difference between the standard degree average value and the limit standard degree average value is calculated. The product stability value is calculated based on the fluctuation value and the standard degree difference of the electronic expansion valve to be tested, and the electronic expansion valve to be tested is marked and classified according to the range to which the product stability value belongs.

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