Nuclear instrument coefficient determination method and device, electronic equipment and computer program product

Abstract

The application provides a nuclear instrument coefficient determination method and device, electronic equipment and computer program product; and relates to the technical field of nuclear power. The method comprises the following steps: determining an axial power deviation correction coefficient based on a linear relationship between an in-pile axial power deviation and an out-of-pile axial power deviation; calculating a first residual of the axial power deviation and a second residual of the core power under different nuclear instrument coefficient values based on flux map data of different power levels; determining a characteristic value of the nuclear instrument coefficient when the total residual of the first residual and the second residual has the minimum value; adjusting the nuclear instrument coefficient value and the first residual or the second residual based on a variable weight parameter when the axial power deviation obtained based on the characteristic value does not satisfy a first check standard or the core power obtained does not satisfy a second check value; and determining the adjusted nuclear instrument coefficient value as a target value of the nuclear instrument coefficient when the axial power deviation obtained based on the adjusted nuclear instrument coefficient value satisfies the first check standard and the core power obtained satisfies the second check standard. The embodiment of the application can improve the fitting accuracy of the nuclear instrument coefficient and reduce the output deviation of the nuclear instrument.

Description

Technical Field

[0001] This application relates to the field of nuclear power technology, and in particular to a method, apparatus, electronic device and computer program product for determining nuclear instrument coefficients. Background Technology

[0002] The reactor power neutron monitoring system (RPN) is one of the key systems for monitoring and protecting the reactor. The RPN measures the neutron flux density (reactor power distribution) in the reactor core in real time through an external neutron detector, and monitors the core power and axial power deviation.

[0003] Since the detectors are located outside the reactor core, their measurements cannot directly represent the true power distribution of the reactor core. With the increase in reactor power level, changes in burnup, card drift, detector performance degradation and other factors, it is necessary to periodically calibrate the nuclear detectors of the RPN system, thereby introducing nuclear instrument coefficients for correction, so that the RPN measurements can accurately reflect the actual power level of the reactor core.

[0004] Currently, nuclear instrumentation systems use a uniform sensitivity to fit and correct instrument coefficients. However, the instrument coefficients obtained based on uniform sensitivity are not optimal, and the actual core power distribution is complex, leading to significant deviations in the instrument output results. Summary of the Invention

[0005] According to various embodiments of this application, a method, apparatus, electronic device, and computer program product for determining nuclear instrument coefficients are provided; these can improve the fitting accuracy of nuclear instrument coefficients and reduce nuclear instrument output deviation.

[0006] In a first aspect, this application provides a method for fitting nuclear instrument coefficients, the method comprising: determining an axial power deviation correction coefficient based on the linear relationship between in-core axial power deviation and out-of-core axial power deviation; using the axial power deviation correction coefficient to calculate an axial power deviation fitting value; calculating a first residual of the axial power deviation and a second residual of the core power under different nuclear instrument coefficient values ​​based on flux map data at different power levels; determining an eigenvalue of the nuclear instrument coefficient when the total residual of the first residual and the second residual is minimized; adjusting the nuclear instrument coefficient value and the first residual or the second residual based on a variable weight parameter when the axial power deviation obtained based on the eigenvalue does not meet a first verification criterion, or the core power obtained based on the eigenvalue does not meet a second verification value; and determining the adjusted nuclear instrument coefficient value as the target value of the nuclear instrument coefficient when the axial power deviation obtained based on the adjusted nuclear instrument coefficient value meets the first verification criterion and the obtained core power meets the second verification criterion; wherein the first residual is the residual between the axial power deviation fitting value and the axial power deviation reference value, and the second residual is the residual between the core power fitting value and the core power reference value.

[0007] By dynamically adjusting the variable weight parameters of the nuclear instrument coefficients and residuals according to the above methods, the nuclear instrument coefficients can be flexibly adjusted according to different power levels and flux diagram data, thereby improving the adaptability of the parameters to the actual operating conditions. By continuously adjusting the values ​​of the nuclear instrument coefficients and recalculating the axial power deviation and core power based on the adjusted coefficients, it is ensured that the nuclear instrument system can provide accurate and reliable measurement data at different power levels, thereby improving the fitting accuracy of the nuclear instrument coefficients and reducing the nuclear instrument output deviation. It has strong ease of use and practicality.

[0008] Secondly, this application provides a nuclear instrument coefficient fitting device, the device comprising:

[0009] The first calculation unit is used to determine the axial power deviation correction coefficient based on the linear relationship between the in-pile axial power deviation and the out-of-pile axial power deviation; the axial power deviation correction coefficient is used to calculate the axial power deviation fitting value.

[0010] The second calculation unit is used to calculate the first residual corresponding to the axial power deviation and the second residual of the core power based on flux map data at different power levels and under different nuclear instrument coefficient values.

[0011] The second calculation unit is further configured to determine the characteristic value of the nuclear instrument coefficient when the total residual of the first residual and the second residual is minimized;

[0012] The parameter adjustment unit is used to adjust the value of the nuclear instrument coefficient and the first residual or the second residual based on the variable weight parameter when the axial power deviation obtained based on the characteristic value does not meet the first verification standard, or the core power obtained based on the characteristic value does not meet the second verification value.

[0013] The coefficient output unit is used to determine the adjusted nuclear instrument coefficient value as the target value of the nuclear instrument coefficient when the axial power deviation obtained based on the adjusted nuclear instrument coefficient value meets the first verification standard and the obtained core power meets the second verification standard.

[0014] Wherein, the first residual is the residual between the fitted value of the axial power deviation and the reference value of the axial power deviation, and the second residual is the residual between the fitted value of the core power and the reference value of the core power.

[0015] Thirdly, this application provides an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in any one of the first aspects.

[0016] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any one of the first aspects.

[0017] Fifthly, this application provides a computer program product that, when run on a device, causes the device to perform the method described in any one of the first aspects above.

[0018] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram illustrating the implementation process of the nuclear instrument coefficient fitting method provided in this application embodiment;

[0021] Figure 2 This is a schematic diagram of axial power offset linearity fitting provided in an embodiment of this application;

[0022] Figure 3A schematic diagram of the fitting of the core power and axial power deviation provided in an embodiment of this application;

[0023] Figure 4 This is a schematic diagram of the structure of the nuclear instrument coefficient fitting device provided in the embodiments of this application;

[0024] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0025] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0030] Core power (Pr) and axial power deviation (ΔI) are crucial aspects of reactor core monitoring. The Nuclear Instrumentation System (RPN) continuously monitors these parameters and assesses core power and power deviations (both upper and lower core components) based on the RPN's data, ensuring the reactor operates within permissible limits. To guarantee the accuracy of the RPN's output, periodic calibration is necessary to ensure it accurately reflects the actual power level of the reactor core.

[0031] Core power monitoring can be corrected through periodic thermal balance tests, while axial power deviation can be corrected through periodic core measurement systems.

[0032] Currently, the multi-flux map is fitted using a fitting algorithm in the reactor core measurement system (RIC). This fitting algorithm includes: based on the upper and lower equivalent current signals (upper average current I...). U and lower average current I L The relationship between the average thermal power W (in %FP full power) during the flux plotting period is used to determine the overall sensitivity of the measurement system. Based on the overall sensitivity and the linear relationship between the in-core axial power offset and the out-of-core axial power offset, the various correction coefficients of the nuclear instrumentation system are calculated.

[0033] However, the actual distribution of core power is more complex than the fitting calculation formula of nuclear instrument probes. The fitting characteristics of core thermal power and axial power deviation are nonlinear, and the multivariate linear formula cannot fit the entire data range well. Moreover, since the unit is in an unsteady state during the xenon oscillation experiment, the measurement error of the data platform is inconsistent, resulting in heteroscedastic data in the input data of the fitting process. The uniform sensitivity used to characterize the overall sensitivity of the nuclear instruments is not suitable for actual nuclear instrument calibration, which requires fitting the upper correction coefficient corresponding to the upper current and the lower correction coefficient corresponding to the lower current, resulting in the loss of some information and deviation of the fitting results. Furthermore, the fitting deviation standards of core power and axial power deviation are different. When the fitting deviation of one of them exceeds the tolerance, it is impossible to make further adjustments, and the experimental process and flux plot data need to be re-performed.

[0034] Therefore, the correction coefficients calculated using a uniform sensitivity are not the optimal coefficients for nuclear instrument system coefficient verification. Furthermore, in practical applications, the use of multi-throughput plots during the fitting process involves linear equal-weighted cumulative calculations, which can lead to weight mismatch and significant deviations in the fitting of nuclear instrument coefficients.

[0035] To address the aforementioned technical problems, this application provides a method for fitting nuclear instrument coefficients. Based on the linear relationship between in-core axial power offset and out-of-core axial power offset, the relationship between in-core axial power offset and thermal power, the relationship between out-of-core axial power offset and upper and lower average currents, and the residual calculation formulas corresponding to core power and axial power deviations, the method fits and calculates the correction coefficients of nuclear instruments. This method can more comprehensively and with lower deviation fit the out-of-core nuclear instrument coefficients, overcome the shortcomings of existing correction methods, improve the calibration level of nuclear instruments, reduce the calibration requirements of out-of-core nuclear instruments, effectively reduce the number of reactor transient experiments, reduce the mainline time of physical experiments, and improve unit utilization.

[0036] The following examples illustrate the specific implementation process of the nuclear instrument coefficient fitting method.

[0037] First, we introduce the requirements that the nuclear instrumentation system must meet to verify the core power and axial power deviations, as well as the fitting formula for the nuclear instrumentation system; among them, the verification deviation of the nuclear instruments must meet the requirements of the following expression:

[0038] |P KME -Pr|<5%;

[0039] |△I RPN -△I in |<3% (RPN verification security criteria);

[0040] |△I RPN -△I in |<1.5% (RPN verification operation criteria);

[0041] Among them, P KME The core thermal power is measured for thermal equilibrium; Pr is the core power measured by the RPN nuclear instrument; ΔI in The axial power deviation measured by the core measurement system; △I RPN The axial power deviation measured by the nuclear instrumentation system.

[0042] The fitting expression for the nuclear instrumentation system is:

[0043] I U = (I1+I2) / 2 (1)

[0044] I L = (I3+I4) / 2 (2)

[0045] Pr = G(K) U I U + K L I L (3)

[0046] △I = α(K) U IU - K L I L (4)

[0047] Among them, I1, I2, I3, and I4 are the four current segments of the nuclear instrument probe from top to bottom (taking a nuclear instrument probe with a power range of 4-segment ionization chamber as an example); I U I is the average current at the top. L K represents the average current at the bottom. U K represents the upper correction coefficient of the nuclear instrumentation system based on the fitting of the upper current (I1+I2). L The lower correction coefficients of the nuclear instrumentation system based on the fitting of the lower current (I3+I4) are assigned to K respectively. U and K L The parameter values ​​can more comprehensively characterize the sensitivity relationship of the current in each section; G is the correction coefficient for fitting the core power; α is the correction coefficient for fitting the axial power deviation.

[0048] Secondly, the calculation methods for axial power deviation ΔI and axial power offset AO are introduced. Axial power offset AO is a shape factor of axial power distribution, which is a relative quantity, and AO may be the same at different power levels. The value of axial power deviation is related to the relative power of the unit. The calculation expression for the axial power offset of nuclear instruments is as follows:

[0049]

[0050] Correspondingly, the axial power deviation ΔI has a multiple relationship with the axial power offset AO, and the relationship expression is as follows:

[0051]

[0052] Among them, I U and I L The upper average current and lower average current are calculated based on the above formulas (1) and (2), where W is the reactor power.

[0053] During the initial reactor startup phase, the nuclear instrumentation system was modified via K... U K L The values ​​of G and α are used to make the deviations in core power and axial power output by the nuclear instrumentation system as close as possible to the reference value P measured on a specific platform. KME and △I in (or △I) RIC Furthermore, the difference between the value and the reference value must not exceed the verification deviation requirement.

[0054] The process of drawing flux diagram data will be described below.

[0055] During the initial physical testing, the nuclear instrumentation system needs to be calibrated at various stages of the power platform ramp-up process (e.g., 10%, 30%, 50%, 75%, 100%). By calibrating each power platform, the output values ​​of the nuclear instruments, Pr and ΔI, must be fitted to the reference values, and the fitting results of the nuclear instruments must not exceed the aforementioned verification deviation requirements.

[0056] The following describes the process of fitting the nuclear instrument coefficients. In this embodiment, the nuclear instrument coefficients include the upper correction coefficient K. U Lower correction coefficient K L Nuclear power correction factor G, axial power deviation correction factor α, the following is the calculation process of α and K U K L The fitting process will be explained.

[0057] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating the implementation process of the nuclear instrument coefficient fitting method provided in this application embodiment. Figure 1 As shown, the method may include the following steps:

[0058] S101, based on the linear relationship between the axial power offset inside the stack and the axial power offset outside the stack, determine the axial power deviation correction coefficient; the axial power deviation correction coefficient is used to calculate the fitted value of the axial power deviation.

[0059] In this embodiment of the application, it is assumed that the in-pile axial power offset and the out-of-pile axial power offset have a linear relationship as expressed by the following expression:

[0060] AO ex = a + bAO in (7)

[0061] Among them, AO ex For the axial power offset outside the stack, AO in This refers to the axial power offset within the stack.

[0062] In this embodiment of the application, in order to more accurately measure the AO within the heap in AO output of the calibration external nuclear instrument ex It is necessary to select points and perform fitting within a relatively wide range of AO; at the 50% FP power platform, a large fluctuation in AO is caused by inserting and lifting power bars, and flux diagrams are plotted to record the relevant results. The above results are then used to fit the nuclear instrument coefficients at platforms after 50% FP.

[0063] In the process of fitting the nuclear instrument coefficients, the flux map data used is obtained by physical experiments at various power platforms. For example, steady-state flux map measurements are performed at each of the above power platforms, xenon oscillation tests are performed at the 50% FP power platform, and parameter fitting is performed using multi-flux map data for parameter adjustments from the 50% FP power platform onwards.

[0064] For example, Table 1 shows the multi-flux diagram data during the commissioning and startup phase of a nuclear power plant, including multi-flux diagram data plotted for each power platform at 50%FP, 75%FP, and 100%FP. Among them, at the 50%FP platform, the xenon oscillation of the unit is induced by lifting and inserting the power rod of the control rod, so that ΔI obtains a larger value range at the 50% platform. Multiple flux diagrams are measured at the 50%FP platform, such as flux diagrams 1 to 6 if needed.

[0065] Serial Number platform <![CDATA[I U (A)]]> <![CDATA[I L (A)]]> <![CDATA[P KME (%FP)]]> <![CDATA[△I RIC (%FP)]]> 1 50% First time 9.1076E-05 9.8300E-05 48.94 -16.5451 2 50% for the second time 9.1183E-05 9.6220E-05 49.03 -14.3774 3 50% 3rd time 9.2068E-05 9.5379E-05 49.15 -12.6082 4 50% 4th time 9.2534E-05 9.4152E-05 49.2 -10.8882 5 50% 5th time 9.3672E-05 9.3325E-05 49.31 -8.8586 6 50% 6th time 9.4823E-05 9.2537E-05 49.01 -6.7914 7 75％ 1.3902E-04 1.3883E-04 73.53 -10.0973 8 100％ 1.8372E-04 1.8461E-04 98.99 -11.4946

[0066] Table 1

[0067] Among them, I in Table 1 U and I L P represents the upper average current and lower average current output by the nuclear instrument. KME The core thermal power measured by a specific measurement system is used as a reference value for the core power fitting by nuclear instruments; that is, the core power reference value corresponding to the core power fitting value; △I RIC The axial power deviation within the reactor core, measured by a specific measurement system (such as the reactor core measurement system RIC), is used as a reference value for the axial power deviation fitted by nuclear instruments; that is, the axial power deviation reference value corresponding to the fitted axial power deviation value.

[0068] In some embodiments, the axial power deviation correction coefficient is determined based on the linear relationship between the in-pile axial power deviation and the out-of-pile axial power deviation, including:

[0069] Based on the average values ​​of the upper and lower currents, an expression for the external axial power offset is determined; based on the multiple relationship between the internal axial power deviation and the internal axial power offset, an expression for the internal axial power offset is determined; based on the expressions for the external axial power offset, the internal axial power offset, and the linear relationship expression between the external axial power offset and the internal power offset, an axial power deviation correction coefficient is determined.

[0070] For example, the flux maps used in traditional fitting operations are incomplete. For instance, for flux map data numbered 1 to 8, only six flux map data points (numbers 1-5 and 8) are used on a 100% FP power platform. Furthermore, the fitting results using these six flux map data points still show deviations from the verification standard. This application, however, uses all flux map data numbered 1 to 8 for fitting and can achieve fitting results that meet the verification standard, applicable to all power platforms from 50% FP to 100% FP. Based on all flux map data in Table 1, i.e., flux map data numbered 1 to 8, the axial power offset AO is fitted. The external axial power offset is calculated based on the calculation method of nuclear instrument axial power offset. Based on the multiple relationship between the axial power deviation ΔI and the axial power offset AO, the internal axial power offset is calculated. The calculated external and internal axial power offsets are fitted, and a linear relationship between the two is evaluated.

[0071] In some embodiments, flux plot data includes the average upper current value, the average lower current value, reactor thermal power, and in-core axial power deviation measured by nuclear instruments; the external axial power offset is calculated based on the average upper current value and the average lower current value; the in-core axial power offset is calculated based on the reactor thermal power and axial power deviation reference values; and the external axial power offset and the in-core axial power offset are fitted using the least squares method.

[0072] For example, based on the average upper and lower current values ​​shown in Table 1, the expression for calculating the axial power offset outside the stack can be obtained using formula (5):

[0073]

[0074] Based on formula (6), the expression for calculating the axial power offset within the stack can be obtained:

[0075]

[0076] Among them, AO in For the axial power offset within the reactor core, ΔI in Here, W represents the reference value for axial power deviation, and W represents the reactor thermal power.

[0077] For example, based on the flux plot data in Table 1 and the linear relationship shown in Formula (7), the AO calculated by Formula (8) is... ex AO calculated using formula (9) inLinear regression analysis was performed, and least squares fitting was used. The linear correlation coefficient R square was 0.9531, which is close to 1. This indicates that the linearity of the fitting model is very good, and that the fitting effect of formula (7) is excellent, which can well characterize the linear relationship between the AO inside and outside the pile.

[0078] like Figure 2 The diagram shown is a schematic of linear fitting of axial power product offset. Figure 2 (a) in the text represents AO ex and AO in The linear fitting residuals are represented by the AO calculated based on formula (9). in The vertical axis is AO ex With AO in The residuals, based on their distribution, indicate that the sum of the residuals is close to 0; Figure 2 (b) in the text refers to the pair AO. ex and AO in The linear fitting plot, with the horizontal axis representing the AO calculated based on formula (9). in The vertical axis represents the AO calculated based on formula (8). ex (as shown by Y in the figure), and based on AO in Predicted AO ex (As shown in the predicted Y in the figure), it can be seen that the trajectory trends of the two are similar and almost overlap, indicating that the axial power offset inside the pile and the axial power offset outside the pile fitted based on the flux map data of serial numbers 1 to 8 conform to the above linear relationship. Furthermore, the intercept obtained by fitting based on formula (7) is 5.0605, and the slope obtained by fitting is 0.5279. Therefore, the linear relationship expression is obtained as: AO ex =5.0605+0.5279AO in That is, a = 5.0605, b = 0.5279.

[0079] In some embodiments, an expression for calculating the external axial power offset based on the upper average current and the lower average current, and an expression for the linear relationship between the external axial power offset and the internal axial power offset, are used to calculate the axial power deviation correction coefficient.

[0080] For example, through the above-described AO ex and AO in The expression obtained from linear fitting, and based on formulas (5) and (6), can be used to further calculate the axial power deviation correction coefficient α. Using formulas (5) and (7), the following expression can be obtained:

[0081]

[0082] The following expression can be obtained from formulas (6) and (7):

[0083]

[0084] For example, the G value is used to rapidly adjust the core power Pr, and the G value varies between 0.95 and 1.05, characterizing the K-based core power Pr. U and K L After calibrating the core power Pr, adjust the value of G so that the residual difference between the adjusted value and the reference value does not exceed 5%, providing a relative reference for the recalibration of nuclear instrument coefficients. For example, the value of G can be set to 1.

[0085] Accordingly, when G is 1, the formula for calculating the reactor thermal power W is:

[0086] W = G(K U ×I U +K L ×I L (G=1) (12)

[0087] Therefore, the following relationship can be obtained:

[0088]

[0089] After conversion, we obtain:

[0090]

[0091] as well as:

[0092] △I out =α(K U I U -K L I L (4)

[0093] Through linear fitting, the fitting values ​​of ΔI inside and outside the heap are approximately consistent, resulting in a = 0 and α = 1 / b. The fitting deviation between ΔI inside and outside the heap originates from AO. ex =a+bAO in The intercept term 'a', when a = 0, α characterizes the proportional relationship between the linear fit of ΔI inside and outside the heap.

[0094] After the above linear fitting, the axial power deviation correction coefficient α = 1 / 0.5279 = 1.894 is obtained; then formula (4) is updated to:

[0095] △I = 1.894 × (K) U I U - K L I L (15)

[0096] When G = 1, the update formula (3) is:

[0097] Pr = K U I U + K L I L (16)

[0098] After the above calculation process, the axial power offset inside the reactor core and the axial power offset outside the reactor core under different power platforms are linearly related, and the linear relationship is characterized by the slope 1 / α; however, the fitting formula of the nuclear instrumentation system (such as formulas (3) and (4)) cannot well express its intercept term α, and there is a certain fitting deviation; after the above analysis, under the condition that the G value and α value are determined, by fitting the parameter K U K L (i.e., nuclear instrument coefficient), further supplementing the information expressed by the missing intercept term.

[0099] S102, based on flux map data at different power levels, calculate the first residual of axial power deviation and the second residual of core power under different nuclear instrument coefficient values. The first residual is the residual between the fitted value of axial power deviation and the reference value of axial power deviation, and the second residual is the residual between the fitted value of core power and the reference value of core power.

[0100] For example, nuclear instrument coefficients include an upper correction factor K. U and lower correction factor K L By assigning a nuclear instrument coefficient K U K L For different values, based on the fitting formulas for axial power deviation and core power, such as formulas (15) and (16), the fitted values ​​of axial power deviation and core power are calculated; based on the core thermal power reference value in the flux diagram (such as P in Table 1) KME ) and axial power deviation reference values ​​(such as ΔI in Table 1) RIC The first residual between the fitted value of the axial power deviation and the reference value of the axial power deviation in the reactor core, and the second residual between the fitted value of the core power and the reference value of the core thermal power are calculated using a loss function or cost function.

[0101] In some embodiments, flux plot data includes the upper average current, the lower average current, reactor thermal power (as a core power reference value), and in-core axial power deviation (as an axial power deviation reference value); based on different nuclear instrument coefficient values ​​and the upper and lower average current values, a fitted value for core power is calculated; based on different nuclear instrument coefficient values ​​and the upper and lower average current values, a fitted value for axial power deviation is calculated; based on a loss function, a first residual of the in-core axial power deviation and the fitted value for axial power deviation are calculated, and a second residual of the fitted values ​​for reactor thermal power and core power is calculated.

[0102] For example, the axial power deviation fitting value is calculated based on formula (15), and the core power fitting value is calculated based on formula (16); combined with the reference values ​​in the flux map data (such as core thermal power and axial power deviation in the reactor), the first residual and the second residual are calculated through the loss function.

[0103] In some embodiments, the core power fit value and the axial power deviation fit value are calculated using the following expressions:

[0104] Pr fit，i =G(K U I U +K L I L );

[0105] △I out，fit，i =α(K U I U -K L I L );

[0106] Where G is the nuclear power correction coefficient, which, based on the above derivation, can be taken as 1; α is the axial power deviation correction coefficient, which, based on the above derivation, can be taken as 1 / b; K U K is the correction factor for the upper average current. L I is the correction factor for the lower average current. U I is the average current at the top. L This represents the average current at the bottom.

[0107] In some embodiments, the first residual and the second residual are calculated using the following expressions:

[0108]

[0109] Among them, Loss fun，DI For the first residual, Loss fun，Pr The second residual is Pr, which is the core power reference value, i.e., the core thermal power in the flux plot data. fit，i The fitted value for core power is ΔI.in The reference value for axial power deviation is ΔI in the flux diagram data (as shown in Table 1). RIC , △I out，fit，i is the fitted value of axial power deviation, and n is the number of flux plot data, such as flux plot numbers 1 to 8.

[0110] S103, when the total residual of the first residual and the second residual is minimized, determine the characteristic value of the nuclear instrument coefficient.

[0111] For example, the total residual Loss can be obtained based on the first residual and the second residual. fun，total The expression is as follows:

[0112]

[0113] Based on the flux diagram data in Table 1, the formula (19) is applied at different K values. U K L The calculation is performed under the given value, when Loss fun，total When the value is at its minimum, determine the nuclear instrument coefficient K. U K L eigenvalues.

[0114] For example, after determining the characteristic values ​​of the nuclear instrument coefficients, the characteristic values, along with the average upper and lower current values ​​in each flux diagram, are substituted into formulas (15) and (16) to obtain the core power and axial power deviations corresponding to each flux diagram output by the nuclear instrument. The core power fitting value calculated based on the characteristic values ​​is used as the core power measured by the nuclear instrument, and it is determined whether it meets the first verification criterion (|P KME -Pr|<5%); The fitted value of the axial power deviation calculated based on the eigenvalue is used as the axial power deviation measured by the nuclear instrumentation system to determine whether it meets the second verification standard (|△I RPN -△I in |<1.5% (RPN verification operation criteria)).

[0115] S104, when the axial power deviation obtained based on the eigenvalue does not meet the first verification standard, or the core power obtained based on the eigenvalue does not meet the second verification value, the nuclear instrument coefficient value and the first or second residual are adjusted based on the variable weight parameter.

[0116] S105, when the axial power deviation obtained based on the adjusted nuclear instrument coefficient values ​​meets the first verification standard and the obtained core power meets the second verification standard, the adjusted nuclear instrument coefficient values ​​are determined as the target values ​​of the nuclear instrument coefficients.

[0117] For example, the values ​​of the nuclear instrument coefficients and the first or second residual can be adjusted using the following expression:

[0118]

[0119] Among them, Loss fun，total The total residual is ω; ω is a variable weight parameter, and ω is a normalized variable balance weight parameter, used to balance the deviations of core power and axial power. Variable weights ω and 1-ω are assigned to the first and second residuals respectively, where 1>ω>0, which can simultaneously and effectively fit the fitting deviation of core power (e.g., |P|). KME -Pr|) and the fitting deviation of axial power deviation (e.g., |△I) RPN -△I in |).

[0120] Accordingly, based on the adjusted nuclear instrument coefficient values, when the calculated axial power deviation meets the first verification standard and the calculated core power meets the second verification standard, the adjusted nuclear instrument coefficient value is determined to be the target value of the nuclear instrument coefficient.

[0121] For example, if ω is selected from 100 points in the range [0,1], the loss is found under the premise of different negative values ​​of ω. fun，total Find the minimum value and obtain the parameter K of the loss function that minimizes the loss function under specific weights. U K L Based on the data in Table 1, the optimal weight ω = 0.22 and the target value of the nuclear instrument coefficient can be obtained through calculation. U =251323.4586, K L =280004.3459.

[0122] like Figure 3 The diagram showing the fitting of core power and axial power deviation is plotted with different power platforms on the horizontal axis, core thermal power (e.g., Original PKEM) and the fitted value of core power (e.g., Fitted PKEM) on the vertical axis, and axial power deviation (Original DI) and the fitted value of axial power deviation (e.g., Fitted DI) on the vertical axis. It can be seen that the trend of the fitted value is basically consistent with the trend of the original value. Table 2 shows the fitted value (Pr_fit) and deviation (Pr_deviation) of core power, and the fitted value (DI_fit) and deviation (DI_deviation) of axial power deviation.

[0123] PLATFORM Pr DI Pr_fit DI_fit Pr_deviation DI_deviation 50％1 49.94 -8.096 50.414 -8.779 1.474 -0.682 50％2 49.03 -7.049 49.858 -7.625 0.828 -0.575 50％3 49.15 -6.197 59.845 -6.757 0.695 -0.561 50％4 49.20 -5.357 49.619 -5.885 0.419 -0.528 50％5 49.31 -4.369 49.673 -4.904 0.363 -0.536 50％6 49.01 -3.329 49.742 -3.939 0.732 -0.610 75％ 73.53 -7.424 73.812 -7.451 -0.282 -0.027 100％ 98.99 -1.138 97.865 -1.045 -1.125 0.926

[0124] Table 2

[0125] As shown in Table 2, the maximum fitting deviation of the core power is -1.125%FP, which meets the requirement of less than 5%FP; the maximum fitting deviation of the axial power deviation is 0.926%FP, which meets the requirement of less than 1.5%FP.

[0126] In some embodiments, if the first residual does not meet the first verification criterion or the second residual does not meet the second verification criterion, the core power and axial power deviations are fitted by adjusting the variable weight parameter under different values ​​of the nuclear instrument coefficients; if the variable weight parameter is greater than 0.5, the first residual is increased to the third residual and the second residual is decreased to the fourth residual by adjusting the variable weight parameter and the nuclear instrument coefficients; or, if the variable weight parameter is less than 0.5, the first residual is decreased to the fifth residual and the second residual is increased to the sixth residual by adjusting the variable weight parameter and the nuclear instrument coefficients.

[0127] For example, when ω > 0.5, at the cost of appropriately amplifying the fitting deviation of the core power, it tends to fit the axial power deviation more closely, thus reducing the deviation of the axial power deviation; when ω < 0.5, at the cost of appropriately amplifying the fitting deviation of the axial power deviation, it tends to fit the core power more closely, thus reducing the deviation of the core power; by adjusting the weight value of ω, the out-of-tolerance requirements of the core power and axial power deviations can be balanced to ultimately meet the calibration requirements of nuclear instruments.

[0128] In some embodiments, after determining the characteristic values ​​of the nuclear instrument coefficients, the method further includes:

[0129] When the axial power deviation fitting value obtained based on the eigenvalue meets the first verification criterion and the core power fitting value obtained based on the eigenvalue meets the second verification criterion, the eigenvalue is determined as the target value of the nuclear instrument coefficient; wherein, different nuclear instrument coefficient values ​​include the eigenvalue.

[0130] This application embodiment can be used for multi-flux diagram calibration of external nuclear instrument parameters in nuclear power plants. If existing calibration parameters exceed the limits, the calibration parameters can be updated by adjusting the balance variable fitting weights, reducing fitting errors and achieving accurate calibration of the nuclear instrument system. It can accurately calibrate nuclear instrument parameters without additional xenon oscillation. It effectively covers all flux diagram data during the 50%-100% power level of the physical test startup period, and can still ensure the accuracy of external instrument calibration after the reactor power is reduced. By adjusting the balance variable parameters and using multi-flux diagram data, the correction coefficients of external nuclear instruments can be accurately calibrated, ensuring the accurate output of nuclear instruments on core power and axial power deviations.

[0131] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0132] Corresponding to the nuclear instrument coefficient fitting method provided in the above embodiments, such as Figure 4 The diagram shown is a schematic of the structure of the nuclear instrument coefficient fitting device provided in this application embodiment. For ease of explanation, only the parts related to this application embodiment are shown.

[0133] The device includes:

[0134] The first calculation unit 41 is used to determine the axial power deviation correction coefficient based on the linear relationship between the in-pile axial power deviation and the out-of-pile axial power deviation; the axial power deviation correction coefficient is used to calculate the axial power deviation fitting value.

[0135] The second calculation unit 42 is used to calculate the first residual and the second residual of the core power corresponding to the axial power deviation based on flux map data of different power levels and under different nuclear instrument coefficient values.

[0136] The second calculation unit 42 is further configured to determine the characteristic value of the nuclear instrument coefficient when the total residual of the first residual and the second residual is minimized;

[0137] The parameter adjustment unit 43 is used to adjust the value of the nuclear instrument coefficient and the first residual or the second residual based on the variable weight parameter when the axial power deviation obtained based on the characteristic value does not meet the first verification standard, or the core power obtained based on the characteristic value does not meet the second verification value.

[0138] The coefficient output unit 44 is used to determine the adjusted nuclear instrument coefficient value as the target value of the nuclear instrument coefficient when the axial power deviation obtained based on the adjusted nuclear instrument coefficient value meets the first verification standard and the obtained core power meets the second verification standard.

[0139] Wherein, the first residual is the residual between the fitted value of the axial power deviation and the reference value of the axial power deviation, and the second residual is the residual between the fitted value of the core power and the reference value of the core power.

[0140] Each unit of the nuclear instrument coefficient fitting device provided in this application embodiment is used to implement the above-mentioned nuclear instrument coefficient fitting method.

[0141] Figure 5 A schematic diagram of the hardware structure of electronic device 5 is shown.

[0142] like Figure 5As shown, the electronic device 5 of this embodiment includes: at least one processor 51 ( Figure 5 Only one is shown in the diagram), and a memory 52 stores a computer program 53 that can run on the processor 51. When the processor 51 executes the computer program 53, it implements the steps in the above method embodiments, for example... Figure 1 S101 to S103 are shown. Alternatively, when the processor 51 executes the computer program 53, it implements the functions of each module / unit in the above-described device embodiments. The electronic device 5 may be a cloud server as described in the above embodiments.

[0143] It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the electronic device 5. In other embodiments of this application, the electronic device 5 may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0144] The electronic device 5 may include, but is not limited to, a processor 51 and a memory 52. ​​Those skilled in the art will understand that... Figure 5 This is merely an example of electronic device 5 and does not constitute a limitation on electronic device 5. It may include more or fewer components than shown, or combine certain components, or different components. For example, the server may also include input sending devices, network access devices, buses, etc.

[0145] The processor 51 mentioned above can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0146] The processor 51 may also include a memory for storing instructions and data. In some embodiments, the memory in the processor 51 is a cache memory. This memory can store instructions or data that the processor 51 has just used or that are used repeatedly. If the processor 51 needs to use the instruction or data again, it can directly retrieve it from the memory. This avoids repeated accesses, reduces the waiting time of the processor 51, and thus improves the efficiency of the system.

[0147] In some embodiments, the aforementioned memory 52 may be an internal storage unit of the electronic device 5, such as a hard disk or memory of the electronic device 5. The memory 52 may also be an external storage device of the electronic device 5, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 5. Furthermore, the memory 52 may include both internal and external storage units of the electronic device 5. The memory 52 is used to store operating systems, applications, bootloaders, data, and other programs, such as program code for computer programs. The memory 52 can also be used to temporarily store data that has been sent or will be sent.

[0148] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0149] It should be noted that the structure of the above-mentioned electronic device is only illustrative and may include other physical structures depending on the application scenario. The physical structure of the electronic device is not limited here.

[0150] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0151] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0152] This application provides a computer program product that, when run on a server, enables the server to execute the steps described in the above-described method embodiments.

[0153] If the integrated modules / units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0154] The electronic devices, computer storage media, and computer program products provided in the embodiments of this application are all used to execute the methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects corresponding to the methods provided above, and will not be repeated here.

[0155] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0156] It should be understood that the above description is merely to help those skilled in the art better understand the embodiments of this application, and is not intended to limit the scope of the embodiments of this application. Based on the examples given above, those skilled in the art can obviously make various equivalent modifications or changes. For example, some steps in the various embodiments of the above detection method may be unnecessary, or new steps may be added. Alternatively, any combination of two or more of the above embodiments may be used. Such modifications, changes, or combinations also fall within the scope of the embodiments of this application.

[0157] It should also be understood that the methods, situations, categories, and classifications of embodiments in this application are for the convenience of description only and should not constitute a special limitation. Various methods, categories, situations, and features in embodiments can be combined without contradiction.

[0158] It should also be understood that, in the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0159] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0160] In the embodiments provided in this application, it should be understood that the disclosed apparatus / network devices and methods can be implemented in other ways. For example, the apparatus / network device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0161] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0162] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

[0163] Finally, it should be noted that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining nuclear instrument coefficients, characterized in that, The method includes: Based on the linear relationship between in-core axial power offset and out-of-core axial power offset, an axial power deviation correction coefficient is determined; the axial power deviation correction coefficient is used to calculate the axial power deviation fitting value. Based on flux map data at different power levels, the first residual of the axial power deviation fitting value and the second residual of the core power fitting value are calculated under different nuclear instrument coefficient values. When the total residual of the first residual and the second residual is minimized, the characteristic value of the nuclear instrument coefficient is determined; If the axial power deviation fitting value obtained based on the feature value does not meet the first verification standard, or the core power fitting value obtained based on the feature value does not meet the second verification standard, the nuclear instrument coefficient value and the first residual or the second residual are adjusted based on the variable weight parameter. When the axial power deviation fitting value obtained based on the adjusted nuclear instrument coefficient values ​​meets the first verification standard, and the core power fitting value obtained meets the second verification standard, the adjusted nuclear instrument coefficient values ​​are determined as the target values ​​of the nuclear instrument coefficients. Wherein, the first residual is the residual between the fitted value of the axial power deviation and the reference value of the axial power deviation, and the second residual is the residual between the fitted value of the core power and the reference value of the core power.

2. The method according to claim 1, characterized in that, After determining the characteristic values ​​of the nuclear instrument coefficients, the method further includes: When the axial power deviation fitting value obtained based on the feature value meets the first verification criterion and the core power fitting value obtained based on the feature value meets the second verification criterion, the feature value is determined to be the target value of the nuclear instrument coefficient; The different values ​​of the nuclear instrument coefficients include the aforementioned characteristic values.

3. The method according to claim 1, characterized in that, The flux map data includes the upper current average value, the lower current average value, the core power reference value, and the axial power deviation reference value; based on the flux map data at different power levels, under different nuclear instrument coefficient values, the calculation of the first residual corresponding to the axial power deviation fitting value and the second residual of the core power fitting value includes: Based on the average value of the upper current and the average value of the lower current, the core power fitting value is calculated under different nuclear instrument coefficient values; Based on the axial power deviation correction coefficient, the average value of the upper current, and the average value of the lower current, the fitted value of the axial power deviation is calculated under different values ​​of the nuclear instrument coefficient. Based on the loss function, the first residual between the fitted value of the axial power deviation and the reference value of the axial power deviation is calculated, and the second residual between the fitted value of the core power and the reference value of the core power is calculated.

4. The method according to claim 3, characterized in that, The step of calculating the first residual between the fitted value of the axial power deviation and the reference value of the axial power deviation based on the loss function, and calculating the second residual between the fitted value of the core power and the reference value of the core power, includes: The first residual, the second residual, and the total residual are calculated using the following expressions: ； ； ； in, The total residual is mentioned; For the first residual, For the second residual, This is a reference value for core power. This is the fitted value of the core power. This is a reference value for axial power deviation. is the fitted value for axial power deviation, and n is the number of flux map data.

5. The method according to claim 4, characterized in that, When the axial power deviation fitting value obtained based on the feature value does not meet the first verification criterion, or the core power fitting value obtained based on the feature value does not meet the second verification criterion, adjusting the nuclear instrument coefficient value and the first residual or the second residual based on the variable weight parameter includes: The values ​​of the nuclear instrument coefficients and the first or second residual are adjusted using the following expression: ； in, The variable weight parameter is referred to here.

6. The method according to claim 1 or 5, characterized in that, The method further includes: When the variable weight parameter is greater than 0.5, by adjusting the variable weight parameter and the value of the nuclear instrument coefficient, the first residual is increased to the third residual, and the second residual is decreased to the fourth residual; or, When the variable weight parameter is less than 0.5, by adjusting the variable weight parameter and the value of the nuclear instrument coefficient, the first residual is reduced to the fifth residual, and the second residual is increased to the sixth residual.

7. The method according to claim 1, characterized in that, The determination of the axial power deviation correction coefficient based on the linear relationship between in-core and out-of-core axial power deviation includes: Based on the average value of the upper current and the average value of the lower current, the expression for the axial power offset outside the stack is determined; Based on the multiple relationship between the in-pile axial power deviation and the in-pile axial power offset, the expression for the in-pile axial power offset is determined; Based on the expressions for the external axial power offset, the expressions for the internal axial power offset, and the linear relationship expression between the external axial power offset and the internal power offset, the axial power deviation correction coefficient is determined.

8. The method according to claim 7, characterized in that, The method further includes: determining the expression for the axial power offset outside the stack based on the average upper current and the average lower current, as follows: in, For axial power offset outside the stack, This represents the average value of the upper current. This represents the average value of the lower current. Based on the multiple relationship between the in-pile axial power deviation and the in-pile axial power offset, the expression for the in-pile axial power offset is determined as follows: in, This refers to the axial power offset within the stack. This is a reference value for axial power deviation. This represents the reactor's thermal power.

9. The method according to any one of claims 1 to 5, 7, and 8, characterized in that, The method further includes: The core power fitting value and the axial power deviation fitting value are calculated using the following expressions: ； Where G is the nuclear power correction factor, and α is the axial power deviation correction factor. This is the correction factor for the average current at the top. This is the correction factor for the lower average current. The average current at the top. This represents the average current at the bottom.

10. A device for determining nuclear instrument coefficients, characterized in that, The device includes: The first calculation unit is used to determine the axial power deviation correction coefficient based on the linear relationship between the in-pile axial power deviation and the out-of-pile axial power deviation; the axial power deviation correction coefficient is used to calculate the axial power deviation fitting value. The second calculation unit is used to calculate the first residual corresponding to the axial power deviation fitting value and the second residual of the core power fitting value based on flux map data at different power levels and under different nuclear instrument coefficient values. The second calculation unit is further configured to determine the characteristic value of the nuclear instrument coefficient when the total residual of the first residual and the second residual is minimized; The parameter adjustment unit is used to adjust the nuclear instrument coefficient value and the first residual or the second residual based on the variable weight parameter when the axial power deviation fitting value obtained based on the feature value does not meet the first verification standard, or the core power fitting value obtained based on the feature value does not meet the second verification standard. The coefficient output unit is used to determine the adjusted nuclear instrument coefficient value as the target value of the nuclear instrument coefficient when the axial power deviation fitting value obtained based on the adjusted nuclear instrument coefficient value meets the first verification standard and the obtained core power fitting value meets the second verification standard. Wherein, the first residual is the residual between the fitted value of the axial power deviation and the reference value of the axial power deviation, and the second residual is the residual between the fitted value of the core power and the reference value of the core power.

11. An electronic device, characterized in that, It includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method of any one of claims 1 to 9.

12. A computer program product, characterized in that, When the computer program product is run on the device, it causes the device to perform the method according to any one of claims 1 to 9.

Images