Method and device for predicting service life of electromagnetic valve

Abstract

The invention relates to a method and a device for predicting the service life of an electromagnetic valve, which are applied to a normal excitation electromagnetic valve or a loss-of-excitation electromagnetic valve and comprise the following steps of: determining key components of the electromagnetic valve; executing an aging test and analysis on the coil, and determining the service life of the coil according to an analysis result; carrying out compression deformation and aging tests on the rubber sealing element, and determining the service life of the rubber sealing element according to test results; executing a stress relaxation test on the spring, and determining the service life of the spring according to a test result; predicting the service life of the electromagnetic valve according to the service life of the coil, the service life of the rubber sealing piece and the service life of the spring. According to the method, the effective service life of the normal excitation-loss or excitation solenoid valve can be effectively evaluated, the accuracy of predicting the service life of the normal excitation-loss or excitation solenoid valve in the industrial production process is improved, the equipment management level of a power plant for the type of solenoid valve can be improved, a proper maintenance strategy can be formulated, and the economical efficiency and safety of power plant production are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic valve life prediction, and more specifically, to a electromagnetic valve life prediction method and device. Background Art

[0002] Solenoid valve is an automatic control device based on the principle of electromagnetic force. It controls the on / off and flow direction of the medium by controlling the on / off of the current signal, thereby controlling the main equipment. Solenoid valves are widely used in industrial automation production processes, mainly used to control the on / off and flow direction of gas or liquid medium channels.

[0003] Solenoid valves are widely used as control and protection equipment in nuclear power plants. The functions of some solenoid valves directly affect the production and safety of power plants. The current preventive maintenance methods for solenoid valves are mainly parameter inspection and regular replacement, but the prediction methods for the life (replacement cycle) of solenoid valves in different environments and uses are relatively simple and lacking.

[0004] At present, the life prediction of solenoid valves on the market is mainly for the action life of solenoid valves, and the service life of solenoid valves is defined by the number of times the solenoid valve can reliably act. This method is suitable for the life judgment of solenoid valves with control functions and frequent actions, but it is not accurate for the life judgment of solenoid valves in normal excitation or normal demagnetization. For example, the solenoid valve of the steam turbine tripping machine in a nuclear power plant is always in the excitation state during the normal operation of the nuclear power plant. When the unit has an abnormal condition and triggers the tripping signal, it will lose magnetism and perform the tripping action. The number of actions of this solenoid valve does not exceed single digits per year. The life of the number of actions of general solenoid valves ranges from tens of thousands to millions of times. If the life of the tripping machine solenoid valve is predicted by the life of the number of actions of the solenoid valve, its life will be as high as more than a thousand years, which is obviously inconsistent with the actual service life of the tripping machine solenoid valve in a nuclear power plant. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method and device for predicting the life of a solenoid valve in view of the problems existing in the prior art.

[0006] The technical solution adopted by the present invention to solve the technical problem is: constructing a life prediction method for a solenoid valve, which is applied to a normally excited solenoid valve or a demagnetized solenoid valve, comprising the following steps:

[0007] Determine the key components of the solenoid valve; the key components include: a coil, a rubber seal and a spring;

[0008] Performing an aging test and analysis on the coil, and determining the life of the coil according to the analysis result;

[0009] Performing compression deformation and aging tests on the rubber seal, and determining the life of the rubber seal according to the test results;

[0010] Performing stress relaxation tests and tests on the spring, and determining the life of the spring based on the test results;

[0011] The life of the solenoid valve is predicted based on the life of the coil, the life of the rubber seal, and the life of the spring.

[0012] In the life prediction method of the solenoid valve described in the present invention, the key components of the solenoid valve are determined including:

[0013] Acquire component information of the solenoid valve and structural information of the solenoid valve;

[0014] The key component is determined according to the component information and the structural information.

[0015] In the life prediction method of the solenoid valve of the present invention, the performing of the aging test and analysis on the coil and determining the life of the coil according to the analysis result comprises:

[0016] Conducting a magnetic induction intensity test on the coil;

[0017] After completing the magnetic induction intensity test, collecting initial data of the coil;

[0018] Performing a high and low temperature alternating aging test on the coil;

[0019] Collecting aging data of the coil during the aging test;

[0020] The life of the coil is evaluated according to the initial data and the aging data to obtain the life of the coil.

[0021] In the life prediction method of the solenoid valve of the present invention, the initial data includes: initial DC resistance, initial insulation resistance and initial excitation temperature;

[0022] The aging data include: aging DC resistance, aging insulation resistance and aging excitation temperature;

[0023] The step of evaluating the life of the coil according to the initial data and the aging data to obtain the life of the coil includes:

[0024] Determining a critical value of the coil aging state according to the initial DC resistance, the initial insulation resistance, the aged DC resistance and the aged insulation resistance;

[0025] Determine the test time according to the critical value of the aging state;

[0026] The life of the coil is obtained by calculating according to the temperature during initial excitation, the temperature during aging excitation, and the test time.

[0027] In the life prediction method of the solenoid valve of the present invention, the step of performing compression deformation and aging tests on the rubber seal and determining the life of the rubber seal according to the test results comprises:

[0028] Obtaining an initial height of the rubber seal;

[0029] Performing an aging test on the rubber seal, obtaining an aging height of the rubber seal after the aging is completed, and recording an aging test temperature of the rubber seal during the aging process; the aging height is the height of the rubber seal after the aging test is completed;

[0030] Determining the evaluation parameter and failure criterion of the rubber seal; the evaluation parameter is compression permanent deformation;

[0031] After determining the evaluation parameter, calculating the test compression rate of the rubber seal according to the initial height and the aging height, or determining the test compression rate of the rubber seal according to a reference standard;

[0032] Determining a critical time according to the test compression ratio and the failure criterion;

[0033] The service life of the rubber seal is obtained by calculating according to the critical time and the aging test temperature.

[0034] In the life prediction method of the solenoid valve of the present invention, the step of obtaining the initial height of the rubber seal comprises:

[0035] placing the rubber seal in a compression fixture;

[0036] Standing for a first preset time under standard test conditions;

[0037] After the compression clamp is opened, it is left to stand for a second preset time, and the current height of the rubber seal is measured; the current height is the initial height of the rubber seal.

[0038] In the life prediction method of the solenoid valve of the present invention, the step of performing an aging test on the rubber seal and obtaining the aging height of the rubber seal after the aging is completed comprises:

[0039] placing the rubber seal in a compression set fixture;

[0040] Place the entire compression set fixture into an aging box for aging;

[0041] After the aging time is reached, taking out the compression permanent deformation fixture from the aging box, and taking out the rubber seal from the compression permanent deformation fixture;

[0042] After staying for a preset period of time, the height of the rubber seal is measured to obtain the aging height of the rubber seal.

[0043] In the life prediction method of the solenoid valve of the present invention, the step of performing a stress relaxation test and a test on the spring and determining the life of the spring according to the test results comprises:

[0044] A double-thread single-cycle loading scheme is used to control the compression of the spring, so that the spring is compressed to a target deformation amount and maintained for a fourth preset time;

[0045] performing a heating test on the spring, and maintaining the spring at a target temperature for a fifth preset time;

[0046] Repeat the above heating test and record a plurality of temperature data of the spring at the target deformation;

[0047] determining a plurality of load attenuation curves of the spring according to the plurality of temperature data and the target deformation;

[0048] The life of the spring is obtained by performing calculations according to the multiple load decay curves.

[0049] In the life prediction method of the solenoid valve of the present invention, predicting the life of the solenoid valve according to the life of the coil, the life of the rubber seal and the life of the spring includes:

[0050] Compare the life of the coil, the life of the rubber seal, and the life of the spring to determine the minimum value of the life;

[0051] The life of the solenoid valve is predicted according to the minimum value of the life.

[0052] The present invention also provides a life prediction device for a solenoid valve, comprising:

[0053] A key component determination unit, used to determine the key components of the solenoid valve; the key components include: a coil, a rubber seal and a spring;

[0054] A coil life analysis unit, used to perform an aging test and analysis on the coil, and determine the life of the coil according to the analysis result;

[0055] A rubber seal analysis unit, used to perform compression deformation and aging tests on the rubber seal, and determine the life of the rubber seal according to the test results;

[0056] A spring life analysis unit, used to perform stress relaxation tests and tests on the spring and determine the life of the spring based on the test results;

[0057] The life prediction unit is used to predict the life of the solenoid valve according to the life of the coil, the life of the rubber seal and the life of the spring.

[0058] The life prediction method and device of the solenoid valve of the present invention have the following beneficial effects: including the following steps: determining the key components of the solenoid valve; performing aging tests and analysis on the coil, and determining the life of the coil according to the analysis results; performing compression deformation and aging tests on the rubber seal, and determining the life of the rubber seal according to the test results; performing stress relaxation tests and tests on the spring, and determining the life of the spring according to the test results; predicting the life of the solenoid valve according to the life of the coil, the life of the rubber seal and the life of the spring. The present invention can effectively evaluate the effective service life of a normally de-excited or excitation solenoid valve, improve the accuracy of the life prediction of a normally de-excited or excitation solenoid valve in the industrial production process, improve the equipment management level of the power plant for this type of solenoid valve, formulate appropriate maintenance strategies, and improve the economy and safety of the power plant production. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0060] Figure 1 It is a schematic flow chart of the life prediction method of the solenoid valve provided by the present invention;

[0061] Figure 2 It is a flow chart of the life evaluation test of the solenoid valve coil provided by the present invention;

[0062] Figure 3 It is a cross-sectional view of a life test of a solenoid valve coil provided by the present invention;

[0063] Figure 4 This is a flow chart of the life evaluation test of the solenoid valve rubber seal provided by the present invention;

[0064] Figure 5 It is a principle block diagram of the life prediction device of the solenoid valve provided by the present invention. DETAILED DESCRIPTION

[0065] 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.

[0066] A large number of solenoid valves used for protection functions in nuclear power plants are in a state of normal excitation or demagnetization. They will only operate when the corresponding protection signal is triggered. Their operation frequency is very low. Conventional life prediction methods based on the number of operations cannot accurately predict the life of such solenoid valves. Moreover, the functions of protection solenoid valves are very important and closely related to safety. Therefore, it is crucial to study the aging failure modes of solenoid valves in normal excitation or demagnetization states, establish life assessment methods and models, and realize life prediction of normal excitation or demagnetization solenoid valves for the economy and safety of industrial production.

[0067] In view of the shortcomings of existing life prediction schemes for solenoid valves in normally excited or demagnetized states, the present invention provides a life prediction method suitable for normally excited or demagnetized solenoid valves, which predicts the service life of the solenoid valve by analyzing the life of key components of the solenoid valve under static conditions.

[0068] Specifically, Figure 1 As shown, the life prediction method of the solenoid valve includes the following steps:

[0069] Step S101: Determine key components of the solenoid valve.

[0070] In the embodiment of the present invention, the key components are the easily aged components of the solenoid valve. The key components include: coils, rubber seals and springs. Alternatively, in some other embodiments, if there is no spring in the solenoid valve, it is not necessary to analyze the life of the spring, but only the life of the coil and the life of the rubber seal. In this case, the final life prediction of the solenoid valve is based on the life of the coil and the life of the rubber seal.

[0071] In an embodiment of the present invention, determining the key components of the solenoid valve includes: obtaining component information of the solenoid valve and structural information of the solenoid valve; and determining the key components according to the component information and structural information. The component information of the solenoid valve is all the components included in the solenoid valve, such as a coil, a rubber seal, a spring, etc. The structural information of the solenoid valve is the specific structure of the solenoid valve. By analyzing the component information and structural information of the solenoid valve, the easily aged components of the solenoid valve, i.e., the key components, can be determined.

[0072] Step S102: Perform an aging test and analysis on the coil, and determine the life of the coil according to the analysis result.

[0073] In an embodiment of the present invention, performing an aging test and analysis on a coil, and determining the life of the coil based on the analysis result includes: performing a magnetic induction intensity test on the coil; collecting initial data of the coil after completing the magnetic induction intensity test; performing a high and low temperature alternating aging test on the coil; collecting aging data of the coil during the aging test; and evaluating the life of the coil based on the initial data and the aging data to obtain the life of the coil.

[0074] Among them, the initial data includes: initial DC resistance, initial insulation resistance and temperature during initial excitation; the aging data includes: aged DC resistance, aged insulation resistance and temperature during aged excitation; the life of the coil is evaluated based on the initial data and the aging data, and obtaining the life of the coil includes: determining the critical value of the aging state of the coil based on the initial DC resistance, initial insulation resistance, aged DC resistance and aged insulation resistance; determining the test time based on the critical value of the aging state; and calculating based on the temperature during initial excitation, the temperature during aged excitation and the test time to obtain the life of the coil.

[0075] Specifically, Figure 2 As shown, first, the coil is tested for magnetic induction strength. The specific test is: the coil is excited, and a Gauss meter is used to check whether the solenoid valve coil generates magnetic force. If not, it is determined that the solenoid valve is damaged and the life test cannot be performed. If magnetic force is generated, it is determined that the life test can be performed. At this time, the initial data needs to be collected, that is, the DC resistance, insulation resistance and excitation temperature of the solenoid valve coil when it is not subjected to accelerated aging are measured using a high-precision multimeter, a thermometer and a super insulation meter, that is, the initial DC resistance, initial insulation resistance and initial excitation temperature. Then the coil is subjected to a high and low temperature alternating aging test. Generally, a high and low temperature alternating damp heat test chamber is used to provide an aging environment for the coil for a total of 1200 hours. During the aging process, the state index is collected, that is, the DC resistance, insulation resistance and excitation temperature of the coil at the end of aging are measured using a high-precision multimeter, a thermometer and a super insulation meter, that is, the aging DC resistance, aging insulation resistance and aging excitation temperature. Finally, the initial DC resistance, initial insulation resistance, initial excitation temperature, aged DC resistance, aged insulation resistance and aged excitation temperature are substituted into the life assessment model for calculation to obtain the life of the coil.

[0076] Among them, the test profile of high and low temperature alternating aging test is as follows Figure 3 shown.

[0077] During the aging test, the aging status indicators of the solenoid valve coil are measured regularly, that is, the DC resistance and insulation resistance of the coil are measured regularly, and compared with the initial DC resistance and initial insulation resistance, so that when the DC resistance or insulation resistance decreases significantly, the test time at the time of decrease is used as the effective life calculation time of the solenoid valve coil. It should be noted that if the DC resistance and insulation resistance of the solenoid valve do not decrease significantly during the test time, the life of the solenoid valve coil is calculated based on the acceptable test time, which is determined according to the characteristics of the solenoid itself.

[0078] Among them, the life assessment model of the coil is:

[0079]

[0080] (1) In the formula, T a and T b It refers to the temperature of the material when it is working, in units of ℃, τa refers to the life of the material at a temperature of Ta, and τb refers to the life of the material at a temperature of Tb. In this test, Ta refers to the temperature of the insulation system of the coil of the unaged sample under the working temperature and excitation conditions, that is, the temperature at the initial excitation, and Tb refers to the temperature of the insulation system of the sample after aging is terminated under the test temperature of 100℃ and the excitation conditions, that is, the temperature at the aging excitation.

[0081] Step S103: performing compression deformation and aging tests on the rubber seal, and determining the life of the rubber seal according to the test results.

[0082] In an embodiment of the present invention, performing compression deformation and aging tests on a rubber seal, and determining the life of the rubber seal based on the test results includes: obtaining an initial height of the rubber seal; performing an aging test on the rubber seal, and obtaining an aging height of the rubber seal after the aging is completed, and recording the aging test temperature of the rubber seal during the aging process; the aging height is the height of the rubber seal after the aging test is completed; determining evaluation parameters and failure criteria of the rubber seal; the evaluation parameter is compression permanent deformation; after determining the evaluation parameter, calculating the test compression rate of the rubber seal based on the initial height and the aging height, or determining the test compression rate of the rubber seal based on a reference standard; determining a critical time based on the test compression rate and the failure criterion; and calculating based on the critical time and the aging test temperature to obtain the life of the rubber seal.

[0083] In an embodiment of the present invention, obtaining the initial height of the rubber seal includes: placing the rubber seal in a compression fixture; leaving it to stand for a first preset time under standard test conditions; opening the compression fixture and leaving it to stand for a second preset time, and measuring the current height of the rubber seal; the current height is the initial height of the rubber seal. Optionally, both the first preset time and the second preset time can be set to 1 day. Of course, in some other embodiments, the first preset time and the second preset time can be adjusted according to actual conditions.

[0084] In an embodiment of the present invention, an aging test is performed on a rubber seal, and after the aging is completed, the aging height of the rubber seal is obtained, which includes: placing the rubber seal in a compression permanent deformation fixture; placing the entire compression permanent deformation fixture in an aging box for aging; after the aging time is reached, taking out the compression permanent deformation fixture from the aging box, and taking the rubber seal out of the compression permanent deformation fixture; after staying for a preset period of time, measuring the height of the rubber seal to obtain the aging height of the rubber seal. The preset time period may be half an hour. Of course, in some other embodiments, the preset time period may be adjusted according to actual conditions.

[0085] Specifically, Figure 4 As shown, firstly, the rubber seal is subjected to an initial compression sample height test, that is, the rubber seal is placed in a compression fixture, parked for 1 day under standard test conditions, and then the compression fixture is opened, and the initial height of the rubber seal is measured after parking for another 1 day. Next, an aging test is performed. That is, the rubber seal is placed in a compression permanent deformation fixture, and then the entire compression permanent deformation fixture is placed in an aging box for aging. Among them, the aging test can be carried out in an aging box with reference to "3512-2014 Hot Air Accelerated Aging and Heat Resistance Test of Vulcanized Rubber or Thermoplastic Rubber". When the sampling time comes, the compression permanent deformation fixture is taken out from the aging box, and after removing the fixture, its height is measured after staying for half an hour, that is, the aging height. By measuring the initial height and the aging height, it can be used to calculate the compression permanent deformation rate of the rubber seal.

[0086] Furthermore, before conducting a life assessment, it is also necessary to determine the evaluation parameters and failure criteria.

[0087] Specifically, compression set and elongation at break are the two most commonly used performance parameters for life prediction of rubber materials. Since the solenoid valve rubber seal plays a sealing role by generating strong elastic stress through compression, so that the gas or liquid in the enclosed space does not leak, the compression set is closer to the actual service state of the seal ring, so it is more appropriate to use the compression set as an evaluation parameter. In the embodiment of the present invention, according to the provisions of the "Rapid Prediction Method for the Service Life of Static Sealing Rubber Products", the critical value of the compression set of 50% is selected as the failure criterion.

[0088] Among them, the aging test conditions are: the aging test temperature is generally three, and the interval between adjacent temperatures is not less than 5 percentage points. Among them, the compression permanent deformation rate can be calculated according to the aging height and initial height measured at different temperatures to obtain the test compression rate. Among them, the calculation of the test compression rate can be calculated by referring to the compression permanent deformation calculation formula of "Determination of compression permanent deformation of vulcanized rubber or thermoplastic rubber Part 1: Under normal and high temperature conditions". Alternatively, when the actual compression rate of the rubber seal cannot be measured, it can be recommended according to "Determination of compression permanent deformation of vulcanized rubber or thermoplastic rubber Part 1: Under normal and high temperature conditions". When the international hardness of the rubber is 10-80, the compression rate is 25%. When the international hardness of the rubber is greater than 80, the compression rates are 15% and 10% at 81-89 and 90-95 respectively.

[0089] Specifically, index tests are carried out during the aging test, that is, at three different accelerated aging temperatures, the test is conducted for 24h, 48h, 96h, and 168h, and then the compression permanent deformation rate (i.e., test compression rate) of the rubber seal is measured every 72 hours. When the compression permanent deformation rate reaches 50%, the test is terminated, and the test time at this time is recorded. The standard "Application of Arrhenius diagram to estimate the service life and maximum operating temperature of vulcanized rubber or thermoplastic rubber" calculation model is used, and the evaluation result, i.e., the service life of the rubber seal, is obtained through two-step linear fitting.

[0090] Step S104: Perform stress relaxation test and test on the spring, and determine the life of the spring according to the test results.

[0091] In an embodiment of the present invention, performing a stress relaxation test and a test on a spring, and determining the life of the spring based on the test results includes: using a dual-thread single-cycle loading scheme to compress and control the spring, so that the spring is compressed to a target deformation and maintained for a fourth preset time; performing a heating test on the spring, and maintaining the spring for a fifth preset time after reaching the target temperature; repeating the above heating test, and recording multiple temperature data of the spring at the target deformation; determining multiple load attenuation curves of the spring based on multiple temperature data and target deformation; calculating based on multiple load attenuation curves to obtain the life of the spring. Optionally, the fourth preset time can be 10 hours, and the fifth preset time can be 30 minutes. Of course, in some other embodiments, the fourth preset time and the fifth preset time can be adjusted according to actual conditions.

[0092] Specifically, according to the structural characteristics of the solenoid valve coil spring and the technical requirements of the high temperature stress relaxation test, the present invention needs to design a set of spring stress relaxation continuous test system (including a high temperature furnace, a spring fixture, a push-pull force sensor, a data acquisition card and a computer). The specific experiments and tests are as follows:

[0093] Step 1: Use a dual-thread single-cycle loading scheme. That is, first use the force loading control method to load the load required for the target deformation; then use the displacement control method to ensure that the spring is compressed to the target deformation (where the target deformation is the deformation of the solenoid valve under normal working conditions), and then maintain the load for 10 hours.

[0094] Step 2: Use a spring clamp to clamp the spring and put it into the high-temperature furnace, and then move the middle beam to an appropriate position (subject to actual test). After assembly, turn off the high-temperature furnace.

[0095] Step 3: Then slowly heat the high temperature furnace to the target temperature over 30 minutes, and then keep it warm for 30 minutes to ensure that the spring is fully heated.

[0096] Step 4: Record the data of the spring at the target deformation and the corresponding temperature to form a spring load attenuation curve and determine the load attenuation of the spring after 10 hours.

[0097] Step 5: After completing the test at this temperature, adjust the temperature of the high temperature furnace and conduct the next test, that is, repeat steps 3 to 4 to obtain test data of spring stress relaxation tests at multiple high temperatures (generally about 5), that is, multiple sets of spring load attenuation curves and corresponding load attenuation amounts.

[0098] Step 6: Calculate the life of the spring based on the multiple sets of spring load decay curves and the corresponding load decay values ​​obtained above. The calculation of the spring life is as follows:

[0099] The continuous stress relaxation method is the main method for measuring stress relaxation of springs. By using a dynamic stress relaxation test device to conduct spring stress relaxation tests at a series of different temperatures, the relationship between temperature and spring load attenuation rate can be obtained:

[0100] ΔP / P=A+Blnt (2);

[0101] (2) In the formula, ΔP = P - P t , P is the initial load before the spring load decays, P t is the real-time load in the stress relaxation test process, so ΔP / P is called the load decay rate. t is the relaxation time, and A and B are temperature-related parameters. A large number of studies have shown that the load decay rate ΔP / P in the spring stress relaxation problem is bilinearly related to the natural logarithm of the relaxation time lnt.

[0102] In addition, since the stress relaxation process can be considered as a thermal activation process of dislocations, the relaxation rate V s The relationship between the absolute temperature T and the activation energy Q required for the dislocation to pass through the barrier conforms to the Arrhenius formula:

[0103]

[0104] (3) In the formula, V s is the relaxation rate, which is defined in this problem as Q is the activation energy required for a dislocation to cross an obstacle under a certain stress. γ is a constant, and k is the Boltzmann constant (8.6×10 ―5 eV / K), T is the absolute temperature (K).

[0105] Taking the natural logarithm of both sides of equation (3), we get:

[0106]

[0107] Therefore In the coordinate system, the logarithm of the relaxation rate is linearly related to the inverse of the absolute temperature. If the slope of the straight line is m, then:

[0108]

[0109] Right now:

[0110] Q = ―m × k (6);

[0111] Therefore, by determining the stress relaxation rate at different temperatures, the activation energy Q can be calculated according to formula (6). By comparing the stress relaxation rate at a higher test temperature (T1) with the stress relaxation rate at the normal working temperature of the spring (T0), we can obtain:

[0112]

[0113] So the stress relaxation rate under working temperature T0 can be obtained:

[0114]

[0115] The requested The value is the coefficient of the stress relaxation stage II equation at the working temperature, that is, the coefficient in equation (2)

[0116] In addition, if the relaxation time t = 1h is substituted into equation (2), we can obtain:

[0117]

[0118] Therefore, the coefficient A in the relaxation equation ΔP / P=A+Blnt can be understood as the load attenuation rate after the spring stress relaxes for 1 hour. According to formula (3), it can be obtained:

[0119]

[0120] Taking the natural logarithm of both sides of equation (9), we get:

[0121]

[0122] According to formula (11), lnA and The linear relationship between the spring and the relaxation stage II can be determined by

[0123] Finally, the activation energy is used to obtain the coefficients in the relaxation equation at the operating temperature. The life of the spring at the normal operating temperature of the solenoid valve can be predicted through stress relaxation tests at a series of temperatures.

[0124] Step S105: predicting the life of the solenoid valve according to the life of the coil, the life of the rubber seal and the life of the spring.

[0125] In the embodiment of the present invention, predicting the life of the solenoid valve according to the life of the coil, the life of the rubber seal and the life of the spring includes: comparing the life of the coil, the life of the rubber seal and the life of the spring to determine the minimum value of the life; predicting the life of the solenoid valve according to the minimum value of the life. That is, the life of the component with the shortest life among the life of the coil, the life of the rubber seal and the life of the spring is the life of the solenoid valve.

[0126] It should be noted that there is no order requirement for the aforementioned steps S102, S103, and S104, and they can be executed sequentially or in parallel, and the present invention does not make any specific limitation thereto.

[0127] refer to Figure 5 The present invention also provides a life prediction device for a solenoid valve.

[0128] like Figure 5 As shown, the life prediction device of the solenoid valve includes:

[0129] The key component determination unit 501 is used to determine the key components of the solenoid valve; the key components include: a coil, a rubber seal and a spring;

[0130] The coil life analysis unit 502 is used to perform an aging test and analysis on the coil, and determine the life of the coil according to the analysis result;

[0131] The rubber seal analysis unit 503 is used to perform compression deformation and aging tests on the rubber seal and determine the life of the rubber seal according to the test results;

[0132] The spring life analysis unit 504 is used to perform stress relaxation tests and tests on the spring and determine the life of the spring based on the test results;

[0133] The life prediction unit 505 is used to predict the life of the solenoid valve according to the life of the coil, the life of the rubber seal and the life of the spring.

[0134] Specifically, the specific coordinated operation process between the units in the solenoid valve life prediction device here can refer to the above-mentioned solenoid valve life prediction method, which will not be repeated here.

[0135] The life prediction method of the solenoid valve of the present invention can effectively evaluate the effective service life of the normal demagnetization or excitation solenoid valve, and solves the problem that the current solenoid valve action number life evaluation method on the market is inaccurate in evaluating the life of the normal demagnetization or excitation solenoid valve. It improves the accuracy of the life prediction of the normal demagnetization or excitation solenoid valve in the industrial production process, can improve the factory's equipment management level for this type of solenoid valve, formulate appropriate maintenance strategies, and improve the economy and safety of factory production.

[0136] For example: Nuclear power plants have a large number of solenoid valves used in protection actuators. These solenoid valves are in an excitation or demagnetization state for a long time, and will only act to perform protection actions after the protection signal is triggered. The functions of these solenoid valves directly affect nuclear safety and power plant production. It is unacceptable to repair or replace them after a failure. A preventive maintenance and replacement strategy must be formulated, and its replacement cycle requires high accuracy. The current prediction method of the number of actions as the life of the solenoid valve is obviously inconsistent with the life of the solenoid valve actually used on site. Through the solenoid valve life prediction method of the present invention, the degradation of the insulation material of the solenoid valve coil, the permanent compression deformation of the seal and the spring stress relaxation life of the solenoid valve under static conditions can be well predicted, thereby accurately predicting the service life of the solenoid valve under static conditions. This technology has been successfully applied to the turbine trip protection solenoid valve of a nuclear power plant in China, accurately predicting the effective service life of the trip solenoid valve, and the prediction result has a high degree of fit with the actual service life on site, providing strong support for the formulation of the replacement cycle of the turbine trip solenoid valve.

[0137] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0138] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0139] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0140] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot limit the scope of protection of the present invention. All equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A life prediction method for a solenoid valve, applied to a normally excited solenoid valve or a demagnetized solenoid valve, characterized in that: The following steps are involved: Determine the key components of the solenoid valve; the key components include: a coil, a rubber seal and a spring; Performing an aging test and analysis on the coil, and determining the life of the coil according to the analysis result; Performing compression deformation and aging tests on the rubber seal, and determining the life of the rubber seal according to the test results; Performing stress relaxation tests and tests on the spring, and determining the life of the spring based on the test results; The life of the solenoid valve is predicted based on the life of the coil, the life of the rubber seal, and the life of the spring.

2. The life prediction method of a solenoid valve according to claim 1, characterized in that: The key components of the solenoid valve include: Acquire component information of the solenoid valve and structural information of the solenoid valve; The key component is determined according to the component information and the structural information.

3. The life prediction method of a solenoid valve according to claim 1, characterized in that: The performing of the aging test and analysis on the coil and determining the life of the coil according to the analysis result comprises: Conducting a magnetic induction intensity test on the coil; After completing the magnetic induction intensity test, collecting initial data of the coil; Performing a high and low temperature alternating aging test on the coil; Collecting aging data of the coil during the aging test; The life of the coil is evaluated according to the initial data and the aging data to obtain the life of the coil.

4. The life prediction method of a solenoid valve according to claim 3, characterized in that: The initial data include: initial DC resistance, initial insulation resistance and initial excitation temperature; The aging data include: aging DC resistance, aging insulation resistance and aging excitation temperature; The step of evaluating the life of the coil according to the initial data and the aging data to obtain the life of the coil includes: Determining a critical value of the coil aging state according to the initial DC resistance, the initial insulation resistance, the aged DC resistance and the aged insulation resistance; Determine the test time according to the critical value of the aging state; The life of the coil is obtained by calculating according to the temperature during initial excitation, the temperature during aging excitation, and the test time.

5. The life prediction method of a solenoid valve according to claim 1, characterized in that: The performing of the compression deformation and aging test on the rubber seal and determining the life of the rubber seal according to the test results comprises: Obtaining an initial height of the rubber seal; Performing an aging test on the rubber seal, obtaining an aging height of the rubber seal after the aging is completed, and recording an aging test temperature of the rubber seal during the aging process; the aging height is the height of the rubber seal after the aging test is completed; Determining the evaluation parameter and failure criterion of the rubber seal; the evaluation parameter is compression permanent deformation; After determining the evaluation parameter, calculating the test compression rate of the rubber seal according to the initial height and the aging height, or determining the test compression rate of the rubber seal according to a reference standard; Determining a critical time according to the test compression ratio and the failure criterion; The service life of the rubber seal is obtained by calculating according to the critical time and the aging test temperature.

6. The life prediction method of a solenoid valve according to claim 5, characterized in that: The obtaining of the initial height of the rubber seal comprises: placing the rubber seal in a compression fixture; Standing for a first preset time under standard test conditions; After the compression clamp is opened, it is left to stand for a second preset time, and the current height of the rubber seal is measured; the current height is the initial height of the rubber seal.

7. The life prediction method of a solenoid valve according to claim 5, characterized in that: The step of performing an aging test on the rubber seal and obtaining the aging height of the rubber seal after the aging is completed comprises: placing the rubber seal in a compression set fixture; Place the entire compression set fixture into an aging box for aging; After the aging time is reached, taking out the compression permanent deformation fixture from the aging box, and taking out the rubber seal from the compression permanent deformation fixture; After staying for a preset period of time, the height of the rubber seal is measured to obtain the aging height of the rubber seal.

8. The life prediction method of a solenoid valve according to claim 1, characterized in that: The performing of the stress relaxation test and the test on the spring and determining the life of the spring according to the test results comprises: A double-thread single-cycle loading scheme is used to control the compression of the spring, so that the spring is compressed to a target deformation amount and maintained for a fourth preset time; performing a heating test on the spring, and maintaining the spring at a target temperature for a fifth preset time; Repeat the above heating test and record a plurality of temperature data of the spring at the target deformation; determining a plurality of load attenuation curves of the spring according to the plurality of temperature data and the target deformation; The life of the spring is obtained by performing calculations according to the multiple load decay curves.

9. The life prediction method of a solenoid valve according to claim 1, characterized in that: The predicting of the life of the solenoid valve according to the life of the coil, the life of the rubber seal and the life of the spring comprises: Compare the life of the coil, the life of the rubber seal, and the life of the spring to determine the minimum value of the life; The life of the solenoid valve is predicted according to the minimum value of the life.

10. A life prediction device for a solenoid valve, characterized in that: include: A key component determination unit, used for determining key components of the solenoid valve; The key components include: coils, rubber seals and springs; A coil life analysis unit, used to perform an aging test and analysis on the coil, and determine the life of the coil according to the analysis result; A rubber seal analysis unit, used to perform compression deformation and aging tests on the rubber seal, and determine the life of the rubber seal according to the test results; A spring life analysis unit, used to perform stress relaxation tests and tests on the spring and determine the life of the spring based on the test results; The life prediction unit is used to predict the life of the solenoid valve according to the life of the coil, the life of the rubber seal and the life of the spring.

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