Method for estimating output of electric valve of nuclear power plant

Abstract

The invention relates to an output estimation method for an electric valve of a nuclear power plant. The method comprises the following steps: S1, acquiring a power time curve and an output time curve corresponding to a driving mechanism corresponding to a valve when the valve acts; s2, a plurality of feature points are extracted according to the working state of the driving mechanism, feature point parameters of the feature points are obtained according to the power time curve and the output time curve, and the feature point parameters comprise power values and output values corresponding to the feature points; s3, after background removal processing is carried out on the power values of the feature point parameters, fitting is carried out on the processed feature parameters based on a preset fitting algorithm, so that a power-force curve corresponding to the valve is obtained; and S4, when the valve acts, an estimated output value of the driving mechanism is obtained based on the characteristic power value corresponding to the driving mechanism and the power-force curve corresponding to the valve. By implementing the method, the valve output evaluation can be conveniently and quickly realized without influencing the working process of a unit.

Description

Technical Field

[0001] The present invention relates to the technical field of valve detection, and more specifically to a method for estimating the output of an electric valve in a nuclear power plant. Background Art

[0002] At present, most nuclear power plants use offline valve diagnostic equipment to perform diagnostic tests on important electric valves during overhaul to evaluate valve performance. Electric valve diagnostic technology is to install various related types of sensors on the electric valve without disassembling the valve. By measuring the electric actuator current, voltage, signal circuit action sequence and the thrust and torque of the valve during operation, it is determined whether the valve has internal leakage, external leakage and refusal to open / close and other fault risks. At the same time, it can determine the status of valve stems, packings, gate discs, valve stem nuts, valve seats and other components, and perform performance evaluation and fault cause analysis on important fault models and main components of electric valves.

[0003] However, in actual applications, the above process has the following disadvantages: the test must be carried out close to the valve, and for valves in the control area, the radiation safety risk is high; it must be implemented during the overhaul, which takes up the overhaul period; and it is impossible to monitor the valve performance status during unit operation.

[0004] In some applications, the voltage and current of the electric actuator are monitored by the control cabinet (MCC: Motor Control Center) of the electric actuator, and its power is calculated accordingly. The output torque of the electric actuator is indirectly predicted by the power to achieve the purpose of evaluating the valve output. It is very important to estimate the output torque (thrust) of the electric actuator based on the electrical signal and ensure a certain accuracy. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for estimating the output of electric valves in a nuclear power plant in view of the above-mentioned technical defects of the prior art.

[0006] The technical solution adopted by the present invention to solve the technical problem is: constructing a method for estimating the output of an electric valve in a nuclear power plant, the method comprising the following steps:

[0007] S1. Acquire a power time curve and an output time curve corresponding to a driving mechanism corresponding to the valve when the valve is in motion;

[0008] S2. extracting a number of characteristic points according to the working state of the driving mechanism, and obtaining characteristic point parameters of the characteristic points according to the power-time curve and the output-time curve, respectively, wherein the characteristic point parameters include the power value and the output value corresponding to the characteristic point;

[0009] S3, after removing the background value of the characteristic point parameter power value, fitting the processed characteristic parameter based on a preset fitting algorithm to obtain a power-force curve corresponding to the valve;

[0010] S4. When the valve is actuated, an estimated output value of the driving mechanism is obtained based on a characteristic power value corresponding to the driving mechanism and a power-force curve corresponding to the valve.

[0011] Preferably, in the method for estimating the output of an electric valve in a nuclear power plant according to the present invention, the method further comprises:

[0012] The driving mechanism is correspondingly arranged on the valve, so as to drive the valve to move through the driving mechanism, and obtain the working parameters of the driving mechanism through a data acquisition instrument corresponding to the driving mechanism.

[0013] Preferably, in the method for estimating the output of an electric valve in a nuclear power plant according to the present invention, in step S2, extracting a plurality of characteristic points according to the working state of the driving mechanism includes:

[0014] The no-load point, the stable operation point, the seating point, the torque trigger point of the driving mechanism, and the process point between the seating point and the torque trigger point are obtained as the characteristic points.

[0015] Preferably, in the method for estimating the output of an electric valve of a nuclear power plant according to the present invention, in the step S3, the power de-basing processing of the characteristic point parameters comprises:

[0016] The power value corresponding to the no-load point is subtracted from the characteristic parameters of all characteristic points to obtain the characteristic parameters corresponding to all characteristic points after background removal processing.

[0017] Preferably, in the method for estimating the output of an electric valve of a nuclear power plant described in the present invention, in the step S3, the processing characteristic point parameters are fitted based on a preset fitting algorithm to obtain a power-force curve corresponding to the valve; comprising:

[0018] The processed feature point parameters are fitted by a quadratic polynomial regression model, wherein the quadratic polynomial regression model is T=k1*P 2 +k2*P+k3, T is thrust or torque, P is power, k1, k2 and k3 are constants; or

[0019] The processed feature point parameters are fitted by a cubic polynomial regression model, wherein the cubic polynomial regression model is T=k4*P 3 +k5*P 2+k6*P+k7, T is thrust or torque, P is power, k4, k5, k6 and k7 are constants.

[0020] Preferably, in the method for estimating the output of an electric valve in a nuclear power plant according to the present invention, in step S4, obtaining the estimated output value of the driving mechanism based on the characteristic power value corresponding to the driving mechanism and the power-force curve corresponding to the valve includes:

[0021] Obtaining the no-load power and operating power corresponding to the driving mechanism to obtain the output of the driving mechanism in driving the valve opening and closing stroke; and / or

[0022] The no-load power and the torque trigger point power corresponding to the driving mechanism are obtained to obtain the output force of the driving mechanism to drive the valve to reach the torque setting value.

[0023] Preferably, in the method for estimating the output of an electric valve in a nuclear power plant according to the present invention, the method further comprises the following steps:

[0024] S11, setting the driving mechanism in a torque verification device to generate a plurality of loading points through the torque verification device, and respectively obtaining loading point parameters of the loading points, wherein the loading point parameters include a power value and an output value corresponding to the loading point;

[0025] S12. Fit the loading point parameters based on a preset fitting algorithm to obtain a power-force curve corresponding to the valve, and execute step S4.

[0026] Preferably, in the method for estimating the output of an electric valve in a nuclear power plant described in the present invention, in step 3, the plurality of loading points include a no-load point, a torque trigger point, and a process point between the no-load point and the torque trigger point.

[0027] Preferably, in the method for estimating the output of an electric valve in a nuclear power plant described in the present invention, in the step S1, the valve action includes: the valve performing an opening action or the valve performing a closing action.

[0028] Preferably, in the method for estimating the output of an electric valve in a nuclear power plant described in the present invention, in the step S12, the preset fitting algorithm includes a quadratic polynomial fitting algorithm or a cubic polynomial fitting algorithm.

[0029] The method for estimating the output of an electric valve in a nuclear power plant according to the present invention has the following beneficial effects: the valve output pre-evaluation can be realized conveniently and quickly without affecting the working process of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0031] Figure 1 It is a program flow chart of an embodiment of a method for estimating the output of an electric valve in a nuclear power plant according to the present invention;

[0032] Figure 2 It is a program flow chart of another embodiment of a method for estimating the output of an electric valve in a nuclear power plant according to the present invention;

[0033] Figure 3 It is a schematic diagram of obtaining characteristic points in an embodiment of a method for estimating the output of an electric valve in a nuclear power plant;

[0034] Figure 4 It is a schematic diagram of a power time curve and an output time curve in an embodiment of a method for estimating the output of an electric valve in a nuclear power plant;

[0035] Figure 5 It is a schematic diagram of a power-force curve in an embodiment of a method for estimating the output of an electric valve in a nuclear power plant according to the present invention. DETAILED DESCRIPTION

[0036] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0037] like Figure 1 FIG. 1 shows an embodiment of a method for estimating the output of an electric valve in a nuclear power plant according to the present invention. Figure 1 In the first embodiment of the method for estimating the output of an electric valve in a nuclear power plant of the present invention, the following steps are included: S1. Obtaining a power time curve and an output time curve corresponding to a driving mechanism corresponding to the valve when the valve is actuated; S2. Extracting a number of characteristic points according to the working state of the driving mechanism, and respectively obtaining characteristic point parameters of the characteristic points according to the power time curve and the output time curve, wherein the characteristic point parameters include the power value and the output value corresponding to the characteristic point; S3. After de-basing the power value of the characteristic point parameter, fitting the processed characteristic parameters based on a preset fitting algorithm to obtain the power-force curve corresponding to the valve; S4. When the valve is actuated, obtaining the estimated output value of the driving mechanism based on the characteristic power value corresponding to the driving mechanism and the power-force curve corresponding to the valve.

[0038] Based on step S1, in the process of driving the valve action by the driving mechanism, a data acquisition instrument with relevant functions is used to obtain the power corresponding to the driving mechanism, and a corresponding power-time curve is obtained. A data acquisition instrument with relevant functions is used to obtain the output-time curve of the driving mechanism when driving the valve action. It can be understood that the power-time curve and the output-time curve can be two curves generated corresponding to the same time axis. The process of power measurement can be calculated by the voltage and current during the working process of the driving mechanism, wherein the process of output measurement can be obtained by a torque and / or thrust data measurement tool.

[0039] Based on step S2, according to the working process of the electric valve, the key working point of the valve is obtained as a characteristic point to obtain characteristic point-to-characteristic point parameters, and the characteristic parameters of each characteristic point include the corresponding power value and output value. It can be understood that the characteristic point corresponds to a certain time point in the working process of the driving mechanism. In a specific embodiment, Figure 3 As shown, the extraction of several characteristic points according to the working state of the driving mechanism includes: obtaining the no-load point, stable operation point, seat point, torque trigger point of the electric valve, and the process point between the seat point and the torque trigger point as the characteristic point. That is, the characteristic point is a special point with a relatively special position relationship between the driving mechanism and the valve. For example, the no-load point is the time point when the driving mechanism starts to operate but does not start to drive the valve, the stable operation point is the stable operation stage when the driving mechanism drives the valve to open or close, the seat point is when the valve core begins to contact the valve seat, and the torque trigger point is the trigger point of the driving mechanism torque signal, wherein the force value can be thrust or torque. The expression of each data obtained can be that the no-load point is (P1, T1), the stable operation point is (P2, T2), the seat point is (P3, T3), the process point between the seat point and the torque trigger point is (P4, T4), and the torque trigger point is (P5, T5), and each point contains a power value (P) and a force value (T).

[0040] In one embodiment, the method for estimating the output of an electric valve in a nuclear power plant of the present invention further includes: the driving mechanism is correspondingly arranged on the valve, so as to drive the valve to move through the driving mechanism, and the working parameters of the driving mechanism are obtained through a data acquisition instrument corresponding to the driving mechanism. In a specific process, it includes but is not limited to setting a driving mechanism on the valve so that the driving mechanism drives the valve to perform a corresponding opening or closing action. At the same time, the working parameters of the driving mechanism are obtained through a data acquisition instrument with relevant functions. For example, the current or voltage corresponding to the driving mechanism is obtained through the data acquisition instrument. In one embodiment, the data acquisition instrument can also be a valve diagnostic instrument, and the working parameters related to the valve in the driving mechanism are obtained through the valve diagnostic instrument.

[0041] Based on the above process, in step S3, the power background removal processing is performed on the characteristic point parameters; including: subtracting the power value corresponding to the no-load point from the characteristic parameters of all characteristic points to obtain the characteristic parameters corresponding to all characteristic points after background removal processing. That is, the power value corresponding to the no-load point is subtracted from the power value of each characteristic point obtained to perform background removal processing, for example, the data corresponding to each characteristic point obtained in the end are (P1-P1, T1), (P2-P1, T2), (P3-P1, T3), (P4-P1, T4) and (P5-P1, T5).

[0042] Further, in the step S3, the processed characteristic point parameters are fitted based on a preset fitting algorithm to obtain the power-force curve corresponding to the valve; including: fitting the processed characteristic point parameters through a quadratic polynomial regression model, wherein the quadratic polynomial regression model is T=k1*P 2 +k2*P+k3, T is thrust or torque, P is power, k1, k2 and k3 are constants. Specifically, data fitting can be implemented based on the above quadratic polynomial regression model to obtain the corresponding power-force curve. Among them, the selection of each constant can be adjusted and set according to experience.

[0043] In one embodiment, in step S3, fitting the processed characteristic point parameters based on a preset fitting algorithm to obtain the power-force curve corresponding to the valve includes: fitting the processed characteristic point parameters through a cubic polynomial regression model, wherein the cubic polynomial regression model is T=k4*P 3 +k5*P 2 +k6*P+k7, T is thrust or torque, P is power, k4, k5, k6 and k7 are constants. Specifically, data fitting can be implemented based on the above cubic polynomial regression model to obtain the corresponding power-force curve. Among them, the selection of each constant can be adjusted and set according to experience.

[0044] In one embodiment, in step S4, obtaining the estimated output value of the driving mechanism based on the characteristic power value corresponding to the driving mechanism and the power-force curve corresponding to the valve includes: obtaining the no-load power and operating power corresponding to the driving mechanism to obtain the output of the driving mechanism driving the valve in the opening and closing stroke. Or obtaining the no-load power and torque trigger point power corresponding to the driving mechanism to obtain the output of the driving mechanism driving the valve to reach the torque setting value.

[0045] Specifically, the power curve is obtained during the daily operation of the unit or when needed, the power characteristic points (no-load power P0', operating power P1', seated power P2') are identified, and the values ​​after subtracting the no-load power (P1'-P0', P2'-P0') are used in the power-force function to obtain the estimated output of the electric valve.

[0046] In one embodiment, if Figure 2 As shown, the method for estimating the output of an electric valve in a nuclear power plant of the present invention also includes: S11, setting the driving mechanism on a torque verification device to generate several loading points through the torque verification device, and obtaining the loading point parameters of the loading points respectively, wherein the loading point parameters include the power value and output value corresponding to the loading point; S12, fitting the loading point parameters based on a preset fitting algorithm to obtain the power-force curve corresponding to the valve, and executing step S4. Specifically, when the driving mechanism is separated from the valve, the driving mechanism can be set on a special driving mechanism torque verification device, and the corresponding power time domain signal can be collected through the torque verification device, and the corresponding torque value can be obtained by reading the torque verification device indication. In the specific data collection process, several loading points are selected to obtain the corresponding loading point parameters, wherein each loading point data includes the power value and output value at the corresponding moment of the recording point, wherein the output value can be understood as torque data. After obtaining multiple sets of data, the loading point number parameters are fitted by a preset fitting algorithm, wherein the preset fitting algorithm can be a quadratic polynomial fitting algorithm or a cubic polynomial fitting algorithm. The specific formula may be the quadratic polynomial regression model or the cubic polynomial regression model constructed above.

[0047] In one embodiment, the plurality of loading points include an unloaded point, a torque trigger point, and a process point between the unloaded point and the torque trigger point. That is, the number of loading points can be as many as possible, but at least the unloaded point, the torque trigger point, and a process point between the unloaded point and the torque trigger point must be included. The expression of each data obtained can be that the unloaded point is (X1, Y1), the torque trigger point is (X3, Y3), and the point between the unloaded point and the torque trigger is (X2, Y2), and each point includes a power value (X) and a force value (Y).

[0048] In a specific implementation, Figure 4As shown, the power-time curve and thrust-time curve corresponding to the driving mechanism can be obtained based on the above step S1. Five power-thrust values ​​1, 2, 3, 4, and 5 are identified in the figure, and the units of power and thrust are kW (kilowatt) and N (newton), respectively, which are the no-load point (0.1, 0), the stable operation point (0.7469, 5606), the seat point (0.8018, 7853), the process point between the seat point and the torque trigger point (2.347, 57829), and the torque trigger point (3.382, 90556). After subtracting the no-load point, (0, 0), (0.6469, 5606), (0.7018, 7853), (2.247, 57829), and (3.282, 90556) are obtained respectively. Use the cubic polynomial model to fit the data of the above points, and select the following coefficients: k4 = -3178.9, k5 = 19357.9, k6 = -1692.9, k7 = -25.4. The mathematical model of the fit is: T = -3178.9P 3 +19357.9*P 2 ―1692.9*P―25.4, the corresponding power-force curve is as follows Figure 5 shown.

[0049] In daily life or when needed, the power data is tested and collected and punctuated (no-load power 0.156kW, operating power 0.7869kW, torque trigger point power 3.271kW, the corresponding characteristic power minus the no-load power is inserted into the power-force function to obtain the corresponding force value. Among them, the force calculation process when the valve is running is to subtract the no-load power from the operating power to obtain (0.7869-0.156)=0.6309kW, which is substituted into the fitted mathematical model, and the output during operation is 5813N. The force calculation process when the valve is closed and the torque is triggered is to subtract the no-load power from the torque trigger to obtain (3.271-0.156)=3.115kW, which is substituted into the fitted mathematical model, and the output during operation is 86451N.

[0050] The above-mentioned power-based electric actuator output method can overcome the shortcomings of the original offline diagnosis method, and can achieve: there is no need to diagnose the valve at the valve, avoiding the radiation and industrial safety risks caused by offline diagnosis; the valve parameters can be obtained at any time in the electrical cabinet and the output can be evaluated without waiting for the unit maintenance window.

[0051] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A method for estimating the output of an electric valve in a nuclear power plant, characterized in that: The method comprises the following steps: S1. Acquire a power time curve and an output time curve corresponding to a driving mechanism corresponding to the valve when the valve is in motion; S2. extracting a number of characteristic points according to the working state of the driving mechanism, and obtaining characteristic point parameters of the characteristic points according to the power-time curve and the output-time curve, respectively, wherein the characteristic point parameters include the power value and the output value corresponding to the characteristic point; S3, after removing the background value of the characteristic point parameter power value, fitting the processed characteristic parameter based on a preset fitting algorithm to obtain a power-force curve corresponding to the valve; S4. When the valve is actuated, an estimated output value of the driving mechanism is obtained based on a characteristic power value corresponding to the driving mechanism and a power-force curve corresponding to the valve.

2. The method for estimating the output of an electric valve in a nuclear power plant according to claim 1, characterized in that: The method further comprises: The driving mechanism is correspondingly arranged on the valve, so as to drive the valve to move through the driving mechanism, and obtain the working parameters of the driving mechanism through a data acquisition instrument corresponding to the driving mechanism.

3. The method for estimating the output of an electric valve in a nuclear power plant according to claim 2, characterized in that: In step S2, extracting a number of feature points according to the working state of the driving mechanism includes: The no-load point, the stable operation point, the seating point, the torque trigger point of the driving mechanism, and the process point between the seating point and the torque trigger point are obtained as the characteristic points.

4. The method for estimating the output of an electric valve in a nuclear power plant according to claim 3, characterized in that: In the step S3, the power background removal processing is performed on the characteristic point parameters; including: The power value corresponding to the no-load point is subtracted from the characteristic parameters of all characteristic points to obtain the characteristic parameters corresponding to all characteristic points after background removal processing.

5. The method for estimating the output of an electric valve in a nuclear power plant according to claim 4, characterized in that: In the step S3, the processed characteristic point parameters are fitted based on a preset fitting algorithm to obtain a power-force curve corresponding to the valve; include: The processed feature point parameters are fitted by a quadratic polynomial regression model, wherein the quadratic polynomial regression model is T=k1*P 2 +k2*P+k3, T is thrust or torque, P is power, k1, k2 and k3 are constants; or The processed feature point parameters are fitted by a cubic polynomial regression model, wherein the cubic polynomial regression model is T=k4*P 3 +k5*P 2 +k6*P+k7, T is thrust or torque, P is power, k4, k5, k6 and k7 are constants.

6. The method for estimating the output of an electric valve in a nuclear power plant according to claim 5, characterized in that: In the step S4, obtaining the estimated output value of the driving mechanism based on the characteristic power value corresponding to the driving mechanism and the power-force curve corresponding to the valve includes: Obtaining the no-load power and operating power corresponding to the driving mechanism to obtain the output of the driving mechanism in driving the valve opening and closing stroke; and / or The no-load power and the torque trigger point power corresponding to the driving mechanism are obtained to obtain the output force of the driving mechanism to drive the valve to reach the torque setting value.

7. The method for estimating the output of an electric valve in a nuclear power plant according to claim 1, characterized in that: The method further comprises the following steps: S11, setting the driving mechanism in a torque verification device to generate a plurality of loading points through the torque verification device, and respectively obtaining loading point parameters of the loading points, wherein the loading point parameters include a power value and an output value corresponding to the loading point; S12. Fit the loading point parameters based on a preset fitting algorithm to obtain a power-force curve corresponding to the valve, and execute step S4.

8. The method for estimating the output of an electric valve in a nuclear power plant according to claim 7, characterized in that: In step 3, the plurality of loading points include a no-load point, a torque trigger point, and a process point between the no-load point and the torque trigger point.

9. The method for estimating the output of an electric valve in a nuclear power plant according to claim 1, characterized in that: In the step S1, the valve action includes: the valve is opened or closed.

10. The method for estimating the output of an electric valve in a nuclear power plant according to claim 7, characterized in that: The preset fitting algorithm includes a quadratic polynomial fitting algorithm or a cubic polynomial fitting algorithm.

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