Reactor protection system and method

Abstract

The present application relates to the field of nuclear power instrument control, and particularly relates to a reactor core protection system and method, comprising: a neutron detection device, used for measuring the neutron flux of the reactor core; a host computer, used for reconstructing the reactor core flux power according to the neutron flux to generate a calibration parameter, and sending the calibration parameter to a verification device; the verification device, used for judging whether the calibration parameter is valid according to the neutron flux and the calibration parameter, and sending the calibration parameter to a lower computer when the calibration parameter is valid; the lower computer, used for calculating the minimum deviation of the bubble nuclear boiling ratio and the local maximum linear power density of the reactor core according to the neutron flux and the calibration parameter; and a control device, used for controlling the control rod of the reactor core according to the minimum deviation of the bubble nuclear boiling ratio and the local maximum linear power density. The present application effectively improves the reliability of the calibration parameter and reduces the risk of protection function misoperation.

Description

Technical Field

[0001] This invention relates to the field of nuclear power instrumentation and control, and specifically to a reactor core protection system and method. Background Technology

[0002] Core protection is a crucial safety measure in nuclear power plant operation. Its purpose is to prevent core damage under abnormal operating conditions and ensure the safe operation of the reactor. The core protection system monitors key core parameters in real time and automatically triggers protective actions, such as inserting control rods, reducing power, or emergency shutdown, based on preset safety limits and protection logic, to maintain the core within safe operating ranges when parameters exceed these limits. Core protection plays a vital role in preventing the release of radioactive materials and protecting public and environmental safety.

[0003] Existing core protection systems typically include the following key modules: a neutron detection device measures the neutron flux of the core; a host computer reconstructs the core flux power distribution based on the neutron flux, generating calibration parameters; a slave computer directly uses the calibration parameters to calculate the minimum departure from nucleate boiling ratio (MDNBR) and peak linear heat generation rate (PLHGR) of the core, compares the calculation results with set safety limits, and generates a protection signal; the control module receives the protection signal and executes corresponding protection actions, such as inserting control rods, reducing power, or emergency shutdown. However, existing core protection systems have a significant drawback: the calibration parameters are not validated before being applied to protection functions. The reliability of calibration parameters is crucial for protection functions; unvalidated parameter application may lead to malfunctions in protection functions, triggering unnecessary control rod insertions or power reductions, affecting unit availability and economic efficiency. Summary of the Invention

[0004] To address the above problems, this invention provides a reactor core protection system and method.

[0005] The first aspect of this invention discloses a core protection system, comprising: Neutron detection equipment is used to measure the neutron flux in the reactor core; The host computer is used to reconstruct the core flux power based on the neutron flux to generate calibration parameters, and send the calibration parameters to the verification equipment; The verification device is used to determine whether the calibration parameters are valid based on the neutron flux and the calibration parameters, and when the calibration parameters are valid, to send them to the lower-level machine. The lower-level machine is used to calculate the minimum deviation nucleus boiling ratio and the local maximum line power density of the reactor core based on the neutron flux and the calibration parameters. A control device for controlling the control rods of the reactor core based on the minimum deviation nucleus boiling ratio and the local maximum linear power density.

[0006] Furthermore, the calibration parameters include: current recombination correction parameters, the ratio of component hot rod integrated power to hot spot integrated power, hot spot line power density corresponding to the neutron detection height, and the final state parameters of the neutron detection device.

[0007] Furthermore, the verification device includes: The storage module is used to store historical neutron flux, historical calibration parameters, historical minimum deviation bubble-nucleus boiling ratio, and historical local maximum line power density. The first verification module is used to verify the neutron flux to determine that the neutron flux is valid; it is also used to perform initial verification of the calibration parameters to determine that the initial verification of the calibration parameters is valid. The calculation module is used to calculate the minimum deviation bubble-nucleus boiling ratio and the maximum local line power density of the calibration parameters based on the neutron flux and the calibration parameters when the neutron flux is valid and the initial calibration parameter is valid. The second verification module is used to perform a consistency verification on the minimum deviation bubble-nucleation boiling ratio of the historical verification and a consistency verification on the local maximum line power density of the historical verification. When both consistency verifications pass, the calibration parameters are determined to be valid.

[0008] Furthermore, the first verification module includes: The neutron flux verification unit is used to process the historical neutron flux based on the exponential weighted average algorithm to obtain the neutron flux trend value, and to perform threshold verification on the neutron flux according to the neutron flux trend. The calibration parameter verification unit is used to process the historical calibration parameters based on the exponential weighted average algorithm to obtain the calibration parameter trend value, and to perform threshold verification on the calibration parameters based on the calibration parameter trend value.

[0009] Furthermore, the neutron flux verification unit performs threshold verification according to the following steps: The neutron flux trend value is calculated based on the historical neutron flux using the exponentially weighted moving average algorithm. The difference between the neutron flux trend value and the neutron flux is calculated to obtain the flux difference. Determine whether the flux difference exceeds a preset flux difference threshold: If the limit is exceeded, the neutron flux becomes invalid. Otherwise, the neutron flux is valid.

[0010] Furthermore, the calibration parameter verification unit performs threshold verification according to the following steps: The trend value of the calibration parameter is calculated based on the historical calibration parameters using the exponentially weighted moving average algorithm. Calculate the difference between the trend value of the calibration parameter and the calibration parameter to obtain the calibration difference; Determine whether the calibration difference exceeds a preset calibration difference threshold: If the time limit is exceeded, the calibration parameters become invalid. Otherwise, the initial verification of the calibration parameters is valid.

[0011] Furthermore, the second verification module includes: The boiling ratio verification unit is used to fit the historical minimum deviation boiling ratio of the bubble nucleus to obtain a boiling ratio fitting value through a polynomial fitting algorithm, and to verify the consistency between the boiling ratio fitting value and the minimum deviation boiling ratio of the bubble nucleus. The density verification unit is used to fit the historical verification local maximum line power density to obtain a line power density fitting value by using a polynomial fitting algorithm, and to verify the consistency between the line power density fitting value and the verification local maximum line power density. The verification unit is used to determine whether the calibration parameters are valid based on the consistency verification result.

[0012] Furthermore, the boiling ratio verification unit performs consistency verification according to the following steps: Based on the historical verification of the minimum deviation of the boiling ratio, a polynomial fitting algorithm is used to fit the boiling ratio to obtain the fitted value. Calculate the boiling ratio fitting residual between the boiling ratio fitting value and the minimum deviation of the boiling ratio from the bubble nucleus; The boiling ratio fitting residual is compared with a preset boiling ratio residual threshold: When the boiling ratio fitting residual exceeds the boiling ratio residual threshold, the minimum deviation of the bubble core boiling ratio fails the consistency check. Otherwise, the minimum deviation of the bubble-nucleus boiling ratio will pass the consistency check.

[0013] Furthermore, the density verification unit performs consistency verification according to the following steps: Based on the historical local maximum line power density, a polynomial fitting algorithm is used to fit the line power density to obtain the fitted value. Calculate the line power density fitting residual between the fitted value and the verified local maximum line power density; The line power density fitting residual is compared with a preset line power density residual threshold: When the line power density fitting residual exceeds the line power density residual threshold, the verification of the local highest line power density fails the consistency check. Otherwise, the verification of the local highest line power density passes the consistency check.

[0014] Furthermore, the neutron detection device includes: The neutron detection module is used to measure neutrons in the reactor core and obtain a simulated neutron flux signal; The signal preprocessing module is used to preprocess the simulated neutron flux signal to obtain the neutron flux.

[0015] Furthermore, the core protection system also includes: The display device is used to display the neutron flux, the calibration parameters, and, when the verification device passes the verification, to display the minimum deviation nucleus boiling ratio and the local maximum line power density.

[0016] Furthermore, the core protection system also includes: The warning device is used to issue a warning message when the verification device fails the verification.

[0017] A second aspect of this invention discloses a core protection method, comprising: Neutron detection equipment measures the neutron flux in the reactor core; The host computer reconstructs the core flux power based on the neutron flux to generate calibration parameters, and sends the calibration parameters to the verification equipment; The verification device determines whether the calibration parameters are valid based on the neutron flux and the calibration parameters. When the calibration parameters are valid, the device sends them to the lower-level machine. The lower-level computer calculates the minimum deviation nucleus boiling ratio and the local maximum line power density of the reactor core based on the neutron flux and the calibration parameters. The control equipment controls the control rods of the reactor core based on the minimum deviation nucleus boiling ratio and the local maximum linear power density.

[0018] This invention introduces a verification device between the host computer and the slave computer, specifically for determining the validity of calibration parameters. The host computer reconstructs the core flux power based on neutron flux, generates calibration parameters, and sends them to the verification device. The verification device uses neutron flux data and calibration parameters to quickly determine the validity of the calibration parameters and sends them to the slave computer only after successful verification. The slave computer only needs to process verified valid parameters, avoiding erroneous calculations based on invalid parameters. This invention effectively improves the reliability of calibration parameters and reduces the risk of malfunctioning protection functions. On the one hand, parameter verification avoids unnecessary control rod insertions or power reductions caused by invalid parameters, improving unit availability; on the other hand, parameter verification ensures that only reliable parameters trigger protection actions, improving the reliability and accuracy of protection functions. Therefore, the core protection system described in this invention, through calibration parameter validity verification, improves unit availability while enhancing the reliability of core protection functions, providing a stronger guarantee for the safe operation of the reactor. Attached Figure Description

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

[0020] Figure 1 This is a schematic diagram of the structure of a core protection system disclosed in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the verification device disclosed in an embodiment of the present invention; Figure 3 This is a schematic flowchart of a core protection method disclosed in an embodiment of the present invention. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, or product comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, apparatus, or products.

[0023] 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 the invention. 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.

[0024] Please see Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a core protection system disclosed in an embodiment of the present invention. Figure 1 As shown, the core protection system includes: Neutron detection device 100 is used to measure the neutron flux of the reactor core; In an optional embodiment, the neutron detection device includes: The neutron detection module is used to measure neutrons in the reactor core and obtain a simulated neutron flux signal; The signal preprocessing module is used to preprocess the simulated neutron flux signal to obtain the neutron flux.

[0025] In this optional embodiment, the neutron detection module is a key component capable of real-time monitoring of neutron flux distribution in the reactor core. Its working principle is based on the measurable electrical signal generated by the interaction of neutrons with specific sensitive materials: when neutrons released from the core undergo a nuclear reaction with sensitive materials (such as boron, uranium, etc.) within the detection module, ionization or thermal effects are produced. By measuring the changes in ionization current, voltage pulses, or thermal electrical signals, the neutron flux intensity can be calculated. The detection module in this embodiment can be a gas ionization detector, a scintillator detector, or a self-powered detector, etc., and this embodiment of the invention is not limited to any particular type.

[0026] The signal preprocessing module performs noise reduction and signal conditioning on the raw analog signal output from the neutron detection module. This module eliminates electromagnetic interference and high-frequency noise through hardware filtering circuits, adjusts the gain of weak electrical signals using signal amplifiers, and then converts the analog signal into a digital signal via an analog-to-digital converter. Temperature compensation and drift correction are simultaneously implemented during preprocessing to eliminate the influence of ambient temperature changes on the detector output, and random noise is further suppressed through digital filtering algorithms to ensure the stability and accuracy of the output signal, providing a reliable data foundation for subsequent flux calculations.

[0027] As can be seen, this optional embodiment, through the collaborative working mechanism of integrating the neutron detection module and the signal preprocessing module, achieves closed-loop optimization of the acquisition, conditioning and digital processing of the raw signal at the detector level, effectively improving the signal-to-noise ratio and anti-interference capability of the neutron flux measurement data, enabling subsequent power reconstruction and parameter calibration to have higher reference accuracy, strengthening the measurement reliability of the core protection system from the data source, and providing a solid physical measurement guarantee for the accurate triggering of the protection logic.

[0028] The host computer 200 is used to reconstruct the core flux power according to the neutron flux to generate calibration parameters, and send the calibration parameters to the verification equipment; In an optional embodiment, the calibration parameters include: current recombination correction parameters, the ratio of component hot rod integrated power to hot spot integrated power, hot spot line power density corresponding to the neutron detection height, and the final state parameters of the neutron detection device.

[0029] In this optional embodiment, the current recombination correction parameter is used to compensate for recombination losses in the neutron detection device's output current signal during transmission and measurement deviations caused by ambient temperature, thereby dynamically correcting the linear relationship between the detector output and neutron flux. The ratio of the component hot rod integrated power to the hot spot integrated power characterizes the power distribution relationship between the hot rod region within the fuel assembly and the overall hot spot region of the core, reflecting the uniformity of the core power spatial distribution. The hot spot linear power density corresponding to the neutron detection height refers to the local maximum linear power density value of the fuel rod at the axial height position of the detector, used to calibrate potential hot spot locations in the three-dimensional power distribution of the core. The final state parameters of the neutron detection device include a set of detector steady-state response parameters after multi-dimensional correction, covering detector sensitivity calibration values, temperature compensation coefficients, and long-term operational drift corrections, ensuring the consistency between neutron flux measurement data and the core physical state.

[0030] The verification device 300 is used to determine whether the calibration parameters are valid based on the neutron flux and the calibration parameters, and when the calibration parameters are valid, to send them to the lower-level machine. In an optional embodiment, the verification device 300 includes: Storage module 310 is used to store historical neutron flux, historical calibration parameters, historical minimum deviation bubble-nucleus boiling ratio, and historical local maximum line power density. The first verification module 320 is used to verify the neutron flux to determine that the neutron flux is valid; it is also used to perform initial verification of the calibration parameters to determine that the initial verification of the calibration parameters is valid. The calculation module 330 is used to calculate the minimum deviation bubble-nucleus boiling ratio and the maximum local line power density of the calibration parameters based on the neutron flux and the calibration parameters when the neutron flux is valid and the initial calibration parameter is valid. The second verification module 340 is used to perform a consistency verification on the minimum deviation bubble-nucleation boiling ratio of the historical verification and a consistency verification on the local maximum line power density of the historical verification. When both consistency verifications pass, the calibration parameters are determined to be valid.

[0031] Figure 2 The diagram shows the structure of the verification device 300. In this optional embodiment, the storage module 310 refers to the basic unit in the verification device 300 used to persistently store the historical data of the reactor core operation. It records the neutron flux, historical calibration parameters, historical verification minimum deviation bubble-nucleation ratio and historical verification local maximum line power density at different time points through a non-volatile storage medium, forming a data reference library that can be called by subsequent verification processes.

[0032] Neutron flux is a physical quantity characterizing the number density of neutrons passing through a unit area per unit time within a nuclear reactor core, directly reflecting the intensity and power level of the core fission reaction; the minimum deviation from nucleation boiling ratio is used to measure the ability of the coolant on the fuel rod surface to suppress nucleation boiling, and its value represents the safety margin between the heat transfer state of the fuel rod surface and the critical state of nucleation boiling under the current operating conditions; the verification local maximum linear power density specifically refers to the maximum thermal power density generated per unit length of the fuel rod at a specific axial height position, characterizing the thermal safety boundary of a local region of the core.

[0033] As can be seen, this optional embodiment, by establishing a multi-level verification mechanism driven by historical data, simultaneously performs neutron flux validity verification, verification of calibration parameter trends, and historical consistency comparison of calculation results before applying calibration parameters. This can effectively identify potential risks such as abnormal detector drift and parameter calculation deviations, reduce the probability of false triggering of protection functions due to the failure of a single verification link, and enhance the adaptability to the continuous change process of core state by using a dynamic verification benchmark established by fitting historical data. This improves the reliability of protection system decisions from both data integrity and logical completeness dimensions.

[0034] In an optional embodiment, the first verification module 320 includes: The neutron flux verification unit 321 is used to process the historical neutron flux based on the exponential weighted average algorithm to obtain the neutron flux trend value, and to perform threshold verification on the neutron flux according to the neutron flux trend. The calibration parameter verification unit 322 is used to process the historical calibration parameters based on the exponential weighted average algorithm to obtain the calibration parameter trend value, and to perform threshold verification on the calibration parameters based on the calibration parameter trend value.

[0035] In an optional embodiment, the neutron flux verification unit performs threshold verification according to the following steps: The neutron flux trend value is calculated based on the historical neutron flux using the exponentially weighted moving average algorithm. The difference between the neutron flux trend value and the neutron flux is calculated to obtain the flux difference. Determine whether the flux difference exceeds a preset flux difference threshold: If the limit is exceeded, the neutron flux becomes invalid. Otherwise, the neutron flux is valid.

[0036] In an optional embodiment, the calibration parameter verification unit performs threshold verification according to the following steps: The trend value of the calibration parameter is calculated based on the historical calibration parameters using the exponentially weighted moving average algorithm. Calculate the difference between the trend value of the calibration parameter and the calibration parameter to obtain the calibration difference; Determine whether the calibration difference exceeds a preset calibration difference threshold: If the time limit is exceeded, the calibration parameters become invalid. Otherwise, the initial verification of the calibration parameters is valid.

[0037] In this optional embodiment, the exponentially weighted moving average algorithm is a statistical method for calculating dynamic trend values ​​by assigning exponentially decreasing weights to historical data. Its core lies in allocating weight coefficients that decay exponentially over time to data at different points in time, giving more weight to recent data in relation to the trend value. This effectively smooths out random fluctuations while preserving the overall trend characteristics of the data. When calculating the trend value based on the exponentially weighted moving average algorithm, a decay coefficient is first set to determine the weight decay rate. Then, historical data is weighted and summed point by point according to the time series. The final output trend value reflects the smooth change pattern of the data over time.

[0038] The setting of flux difference threshold and calibration difference threshold can be combined with the statistical characteristics of historical data and the system safety tolerance requirements. Usually, reasonable statistical boundary values ​​are determined by analyzing the maximum fluctuation range under normal operating conditions in long-term operating data, and then corrected according to the safety margin design index of the core protection system to ensure that the threshold can effectively capture abnormal deviations while avoiding misjudgment due to oversensitivity.

[0039] In the above optional embodiments, the first verification module 320 constructs a dynamic trend baseline by introducing an exponentially weighted moving average algorithm, which can adapt to the continuous changes in core operating parameters. Compared with the fixed threshold verification method, this method avoids false alarms caused by normal core power regulation or slow-changing operating conditions by dynamically adjusting the trend reference value. At the same time, it maintains sensitivity to sudden abnormal fluctuations through the difference threshold mechanism, reducing the impact of noise interference on the verification results while ensuring verification sensitivity. The neutron flux verification unit can effectively identify abnormal states such as sudden detector failure, abnormal signal transmission, or local power distortion in the core by comparing real-time measured values ​​with the dynamic trend baseline generated based on historical data. This prevents verification misjudgments caused by sudden changes in single measured values ​​and improves the reliability of neutron flux data as a basic parameter for protection calculations. The calibration parameter verification unit adopts a combination of trend tracking and threshold verification. It not only verifies the rationality of the absolute value of the current calibration parameter, but also captures the possible mismatch of the calculation model or the deviation of the reconstruction algorithm in the process of generating calibration parameters by analyzing the degree of deviation of the parameters from the historical trend. It ensures the effectiveness of the calibration parameters from the dual dimensions of time continuity and spatial consistency, and provides reliable input that has been verified by multiple levels for subsequent protection calculations.

[0040] In an optional embodiment, the second verification module 340 includes: The boiling ratio verification unit 341 is used to fit the historical minimum deviation bubble core boiling ratio to obtain a boiling ratio fitting value through a polynomial fitting algorithm, and to perform consistency verification between the boiling ratio fitting value and the verification minimum deviation bubble core boiling ratio. Density verification unit 342 is used to fit the historical verification local maximum line power density using a polynomial fitting algorithm to obtain a line power density fitting value, and to perform consistency verification between the line power density fitting value and the verification local maximum line power density. The verification unit is used to determine whether the calibration parameters are valid based on the consistency verification result.

[0041] In an optional embodiment, the boiling ratio verification unit performs consistency verification according to the following steps: Based on the historical verification of the minimum deviation of the boiling ratio, a polynomial fitting algorithm is used to fit the boiling ratio to obtain the fitted value. Calculate the boiling ratio fitting residual between the boiling ratio fitting value and the minimum deviation of the boiling ratio from the bubble nucleus; The boiling ratio fitting residual is compared with a preset boiling ratio residual threshold: When the boiling ratio fitting residual exceeds the boiling ratio residual threshold, the minimum deviation of the bubble core boiling ratio fails the consistency check. Otherwise, the minimum deviation of the bubble-nucleus boiling ratio will pass the consistency check.

[0042] In an optional embodiment, the density verification unit performs consistency verification according to the following steps: Based on the historical local maximum line power density, a polynomial fitting algorithm is used to fit the line power density to obtain the fitted value. Calculate the line power density fitting residual between the fitted value and the verified local maximum line power density; The line power density fitting residual is compared with a preset line power density residual threshold: When the line power density fitting residual exceeds the line power density residual threshold, the verification of the local highest line power density fails the consistency check. Otherwise, the verification of the local highest line power density passes the consistency check.

[0043] In the above optional embodiments, the polynomial fitting algorithm refers to a mathematical method that approximates the distribution pattern of given data points by constructing a polynomial function. The polynomial fitting algorithm selects a polynomial of appropriate degree and calculates its coefficients to minimize the overall deviation between the polynomial curve and the data points. When calculating the fitted value based on this algorithm, the order of the polynomial needs to be determined according to the time series characteristics of historical data, and the optimal coefficient combination is solved using the least squares method to generate a fitted curve that can reflect the trend of data change. Finally, the fitted value is obtained by substituting the independent variable value (such as timestamp or running cycle) corresponding to the current time point.

[0044] The settings for the boiling ratio fitting residual and the line power density fitting residual can take into account the statistical distribution characteristics of the historical fitting residual and the system safety tolerance. Usually, the baseline standard deviation is determined by analyzing the fluctuation range of the historical residual under normal operating conditions. Then, a reasonable multiple coefficient is set according to the sensitivity requirements of the protection system to parameter deviations, so that the threshold can cover normal statistical fluctuations and effectively identify abnormal deviations that exceed the expected range.

[0045] As can be seen, in the above optional embodiments, the second verification module 340 establishes a time evolution model of historical protection parameters through a polynomial fitting algorithm, which can capture the nonlinear characteristics and periodic patterns of parameter changes. Compared with the simple threshold comparison method, this method constructs a dynamic verification benchmark through fitting curves, which can adapt to the gradual shift of core operating parameters caused by changes in burnup and power regulation, reducing the probability of misjudgment caused by normal parameter evolution. At the same time, it quantifies the degree of deviation between the current parameters and historical trends through residual analysis, enhancing the ability to identify sudden abnormal states. The boiling ratio verification unit uses polynomial fitting technology to model the trend of the historical minimum deviation boiling ratio. By analyzing the residual between the current calculated value and the fitted value, it can effectively identify the protection parameter calculation deviation caused by calibration parameter distortion, such as power reconstruction error caused by detector drift or boiling ratio mutation caused by thermal model mismatch, thereby preventing the application of incorrect calibration parameters in the protection logic. The density verification unit, by fitting the evolution trajectory of historical local maximum line power density and combining it with a residual threshold mechanism, verifies the rationality of the current calculated value. This allows for the timely detection of abnormal local power distribution in fuel assemblies or line power density distortion caused by neutron flux measurement inaccuracies. It prevents the risk of protection function failure due to inaccurate capture of local hotspots, thus improving the completeness of core three-dimensional power monitoring. The verification unit simultaneously performs dual consistency verification of boiling ratio and line power density, constructing a multi-dimensional verification matrix. This enables cross-verification of the coordination of calibration parameters across different protection calculation models, reducing the probability of missed detections that may occur with single-parameter verification, and ensuring the overall effectiveness of calibration parameters from a multi-physical coupling dimension.

[0046] The lower-level machine 400 is used to calculate the minimum deviation nucleus boiling ratio and the local maximum line power density of the reactor core based on the neutron flux and the calibration parameters. Control device 500 is used to control the control rods of the reactor core based on the minimum deviation nucleus boiling ratio and the local maximum linear power density.

[0047] In this optional embodiment, the control device acquires the minimum deviation nucleus boiling ratio and the local maximum line power density of the core in real time and dynamically compares them with preset safety limits. When the minimum deviation nucleus boiling ratio is lower than the limit or the local maximum line power density exceeds the limit, the core is determined to be in a thermally unsafe state, and the control rod insertion logic is triggered to quickly suppress the nuclear reaction rate and reduce the core power level. If both parameters are within the safety margin range, the control rod position is adjusted according to the power regulation requirements and a predetermined strategy to achieve steady-state control or load tracking of the core power while maintaining the safety boundary. At the same time, the real-time change gradient of the two parameters is combined to predict the core state evolution trend and trigger the control rod fine-tuning action in advance to avoid potential over-limit risks. Thus, a dynamic balance between core safety and operating economy is achieved through a closed-loop feedback mechanism.

[0048] In an optional embodiment, the core protection system further includes: The display device is used to display the neutron flux, the calibration parameters, and, when the verification device 300 passes the verification, to display the minimum deviation nucleus boiling ratio and the local maximum line power density.

[0049] As can be seen, in this optional embodiment, the display device enables operators to observe the dynamic changes in the neutron flux distribution and calibration parameters in the reactor core in real time, and to intuitively obtain the calculation results of key protection parameters after the verification device 300 confirms the validity of the parameters. This visualization mechanism not only enhances the transparency of information in human-computer interaction, but also facilitates operators to make auxiliary judgments on the automatic verification results of the system based on their engineering experience. At the same time, the historical data display backtracking function provides data support for the analysis of operating status trends and the early identification of abnormal operating conditions, thereby improving the level of system automation while retaining necessary human supervision intervention points.

[0050] In an optional embodiment, the core protection system further includes: The warning device is used to issue a warning message when the verification device 300 fails the verification.

[0051] As can be seen, this optional embodiment proactively triggers alarms when parameter verification fails through audible and visual signals or interface prompts. This shortens the response delay to abnormal states, prompting operators to quickly initiate preset emergency procedures. It avoids the risk of protection function degradation caused by the failure to address calibration parameters in a timely manner. Furthermore, through the synergistic effect of multi-level verification and warning mechanisms, it forms a comprehensive anomaly blocking capability from parameter generation and verification to execution, further strengthening the core protection system's defense-in-depth characteristics. Please see Figure 3 As shown, Figure 3 This is a schematic flowchart of a core protection method disclosed in an embodiment of the present invention. Figure 3 As shown, the core protection method may include the following operations: S301, Neutron detection equipment measures the neutron flux of the reactor core; S302. The host computer reconstructs the core flux power based on the neutron flux to generate calibration parameters, and sends the calibration parameters to the verification equipment. S303. The verification device determines whether the calibration parameters are valid based on the neutron flux and the calibration parameters. When the calibration parameters are valid, the device sends them to the lower-level device. S304. The lower-level machine calculates the minimum deviation nucleus boiling ratio and the local maximum linear power density of the reactor core based on the neutron flux and the calibration parameters. S305. The control device controls the control rods of the reactor core based on the minimum deviation nucleus boiling ratio and the local maximum linear power density.

[0052] For specific limitations on core protection methods, please refer to the limitations on core protection systems mentioned above, which will not be repeated here.

[0053] In summary, the core protection system and method disclosed in this invention effectively improves the reliability of calibration parameters and reduces the risk of malfunction in protection functions. On the one hand, parameter verification avoids unnecessary control rod insertion or power reduction caused by invalid parameters, improving unit availability; on the other hand, parameter verification ensures that only reliable parameters trigger protection actions, improving the reliability and accuracy of protection functions. Therefore, the core protection system described in this invention, through the validity verification of calibration parameters, improves unit availability while enhancing the reliability of core protection functions, providing a stronger guarantee for the safe operation of the reactor. Thus, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0054] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A core protection system, characterized in that, The system includes: Neutron detection equipment is used to measure the neutron flux in the reactor core; The host computer is used to reconstruct the core flux power based on the neutron flux to generate calibration parameters, and send the calibration parameters to the verification equipment; The verification device is used to determine whether the calibration parameters are valid based on the neutron flux and the calibration parameters, and when the calibration parameters are valid, to send them to the lower-level machine. The lower-level machine is used to calculate the minimum deviation nucleus boiling ratio and the local maximum line power density of the reactor core based on the neutron flux and the calibration parameters. Control equipment for controlling the control rods of the reactor core based on the minimum deviation nucleus boiling ratio and the local maximum linear power density; The verification device includes: The storage module is used to store historical neutron flux, historical calibration parameters, historical minimum deviation bubble-nucleus boiling ratio, and historical local maximum line power density. The first verification module is used to verify the neutron flux to determine that the neutron flux is valid; it is also used to perform initial verification of the calibration parameters to determine that the initial verification of the calibration parameters is valid. The calculation module is used to calculate the minimum deviation bubble-nucleus boiling ratio and the maximum local line power density of the calibration parameters based on the neutron flux and the calibration parameters when the neutron flux is valid and the initial calibration parameter is valid. The second verification module is used to perform a consistency verification on the minimum deviation bubble-nucleation boiling ratio of the historical verification and a consistency verification on the local maximum line power density of the historical verification. When both consistency verifications pass, the calibration parameters are determined to be valid.

2. The core protection system according to claim 1, characterized in that, The calibration parameters include: current composite correction parameters, the ratio of component hot rod integrated power to hot spot integrated power, hot spot line power density corresponding to neutron detection height, and final state parameters of the neutron detection device.

3. The core protection system according to claim 1, characterized in that, The first verification module includes: The neutron flux verification unit is used to process the historical neutron flux based on the exponential weighted average algorithm to obtain the neutron flux trend value, and to perform threshold verification on the neutron flux according to the neutron flux trend. The calibration parameter verification unit is used to process the historical calibration parameters based on the exponential weighted average algorithm to obtain the calibration parameter trend value, and to perform threshold verification on the calibration parameters based on the calibration parameter trend value.

4. A core protection system according to claim 3, characterized in that, The neutron flux verification unit performs threshold verification according to the following steps: The neutron flux trend value is calculated based on the historical neutron flux using the exponentially weighted moving average algorithm. The difference between the neutron flux trend value and the neutron flux is calculated to obtain the flux difference. Determine whether the flux difference exceeds a preset flux difference threshold: If the limit is exceeded, the neutron flux becomes invalid. Otherwise, the neutron flux is valid.

5. A core protection system according to claim 3, characterized in that, The calibration parameter verification unit performs threshold verification according to the following steps: The trend value of the calibration parameter is calculated based on the historical calibration parameters using the exponentially weighted moving average algorithm. Calculate the difference between the trend value of the calibration parameter and the calibration parameter to obtain the calibration difference; Determine whether the calibration difference exceeds a preset calibration difference threshold: If the time limit is exceeded, the calibration parameters become invalid. Otherwise, the initial verification of the calibration parameters is valid.

6. A core protection system according to claim 1, characterized in that, The second verification module includes: The boiling ratio verification unit is used to fit the historical minimum deviation boiling ratio of the bubble nucleus to obtain a boiling ratio fitting value through a polynomial fitting algorithm, and to verify the consistency between the boiling ratio fitting value and the minimum deviation boiling ratio of the bubble nucleus. The density verification unit is used to fit the historical verification local maximum line power density to obtain a line power density fitting value by using a polynomial fitting algorithm, and to verify the consistency between the line power density fitting value and the verification local maximum line power density. The verification unit is used to determine whether the calibration parameters are valid based on the consistency verification result.

7. A core protection system according to claim 6, characterized in that, The boiling ratio verification unit performs consistency verification according to the following steps: Based on the historical verification of the minimum deviation of the boiling ratio, a polynomial fitting algorithm is used to fit the boiling ratio to obtain the fitted value. Calculate the boiling ratio fitting residual between the boiling ratio fitting value and the minimum deviation of the boiling ratio from the bubble nucleus; The boiling ratio fitting residual is compared with a preset boiling ratio residual threshold: When the boiling ratio fitting residual exceeds the boiling ratio residual threshold, the minimum deviation of the bubble core boiling ratio fails the consistency check. Otherwise, the minimum deviation of the bubble-nucleus boiling ratio will pass the consistency check.

8. A core protection system according to claim 6, characterized in that, The density verification unit performs consistency verification according to the following steps: Based on the historical local maximum line power density, a polynomial fitting algorithm is used to fit the line power density to obtain the fitted value. Calculate the line power density fitting residual between the fitted value and the verified local maximum line power density; The line power density fitting residual is compared with a preset line power density residual threshold: When the line power density fitting residual exceeds the line power density residual threshold, the verification of the local highest line power density fails the consistency check. Otherwise, the verification of the local highest line power density passes the consistency check.

9. A core protection system according to claim 1, characterized in that, The neutron detection device includes: The neutron detection module is used to measure neutrons in the reactor core and obtain a simulated neutron flux signal; The signal preprocessing module is used to preprocess the simulated neutron flux signal to obtain the neutron flux.

10. A core protection system according to any one of claims 1-9, characterized in that, The core protection system also includes: The display device is used to display the neutron flux, the calibration parameters, and, when the verification device passes the verification, to display the minimum deviation nucleus boiling ratio and the local maximum line power density.

11. A core protection system according to any one of claims 1-9, characterized in that, The core protection system also includes: The warning device is used to issue a warning message when the verification device fails the verification.

12. A method for protecting reactor cores, characterized in that, Applied to the core protection system as described in any one of claims 1-9, the method comprises: Neutron detection equipment measures the neutron flux in the reactor core; The host computer reconstructs the core flux power based on the neutron flux to generate calibration parameters, and sends the calibration parameters to the verification equipment; The verification device determines whether the calibration parameters are valid based on the neutron flux and the calibration parameters. When the calibration parameters are valid, the device sends them to the lower-level machine. The lower-level computer calculates the minimum deviation nucleus boiling ratio and the local maximum line power density of the reactor core based on the neutron flux and the calibration parameters. The control equipment controls the control rods of the reactor core based on the minimum deviation nucleus boiling ratio and the local maximum linear power density.

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