Reactor core protection system and method

Abstract

The invention relates to the field of nuclear power instrument control, in particular to a reactor core protection system and method, and the system comprises neutron detection equipment which is used for measuring the neutron flux of a reactor core; the upper computer is used for reconstructing reactor core flux power according to the neutron flux so as to generate calibration parameters and sending the calibration parameters to the verification equipment; the verification equipment is used for judging whether the calibration parameters are valid or not according to the neutron flux and the calibration parameters, and sending the calibration parameters to the lower computer when the calibration parameters are valid; the lower computer is used for calculating the minimum deviation nucleation boiling ratio and the local highest linear power density of the reactor core according to the neutron flux and the calibration parameters; and the control equipment is used for controlling a control rod of the reactor core according to the minimum deviation nucleation boiling ratio and the local highest linear power density. According to the invention, the reliability of calibration parameters is effectively improved, and the risk of protection function maloperation is reduced.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power instrumentation and control, and in particular to a core protection system and method. Background Art

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

[0003] Existing core protection systems typically include the following key modules: neutron detection equipment measures the core's neutron flux; a host computer reconstructs the core's flux power distribution based on the neutron flux and generates calibration parameters; a slave computer directly uses the calibration parameters to calculate the core's minimum departure from nucleate boiling ratio (MDNBR) and peak linear heat generation rate (PLHGR), compares the calculated results with set safety limits, and generates protection signals; and a control module receives the protection signals and executes corresponding protection actions, such as control rod insertion, power reduction, or emergency shutdown. However, existing core protection systems suffer from a significant flaw: the calibration parameters are not validated before being applied to protection functions. The reliability of calibration parameters is crucial for protection functions; the application of unverified parameters can lead to malfunctions, triggering unnecessary control rod insertions or power reductions, and impacting the unit's availability and economics. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a core protection system and method.

[0005] A first aspect of the present invention discloses a core protection system, comprising:

[0006] Neutron detection equipment to measure the neutron flux in the core;

[0007] A host computer, configured to reconstruct the core flux power according to the neutron flux to generate calibration parameters, and send the calibration parameters to a verification device;

[0008] A verification device, configured to determine whether the calibration parameters are valid based on the neutron flux and the calibration parameters, and to send the calibration parameters to a lower computer when the calibration parameters are valid;

[0009] A lower computer is used to calculate the minimum deviation from nucleate boiling ratio and the local maximum linear power density of the reactor core according to the neutron flux and the calibration parameters;

[0010] A control device is used to control the control rods of the core according to the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

[0011] Furthermore, the calibration parameters include: current composite correction parameters, the ratio of the component hot rod integrated power to the hot spot integrated power, the hot spot line power density corresponding to the neutron detection height and the final state parameters of the neutron detection equipment.

[0012] Furthermore, the verification device includes:

[0013] A storage module is used to store historical neutron flux, historical calibration parameters, historical calibration minimum deviation from nucleate boiling ratio, and historical calibration local maximum linear power density;

[0014] A first verification module is used to verify the neutron flux to determine whether the neutron flux is valid; and is also used to perform an initial verification on the calibration parameters to determine whether the initial verification of the calibration parameters is valid;

[0015] a calculation module, configured to calculate and verify a minimum deviation from nucleate boiling ratio and a local maximum linear power density based on the neutron flux and the calibration parameters when the neutron flux is valid and the initial calibration of the calibration parameters is valid;

[0016] The second verification module is used to perform consistency verification on the verification minimum deviation from nucleate boiling ratio based on the historical verification minimum deviation from nucleate boiling ratio, and to perform consistency verification on the verification local maximum linear power density based on the historical verification local maximum linear power density. When both consistency verifications pass, it is determined that the calibration parameters are valid.

[0017] Furthermore, the first verification module includes:

[0018] a neutron flux verification unit, configured to process the historical neutron flux based on an exponentially weighted average algorithm to obtain a neutron flux trend value, and perform a threshold verification on the neutron flux according to the neutron flux trend;

[0019] The calibration parameter verification unit is used to process the historical calibration parameters based on an exponentially weighted average algorithm to obtain a calibration parameter trend value, and perform threshold verification on the calibration parameter according to the calibration parameter trend value.

[0020] Furthermore, the neutron flux verification unit performs threshold verification according to the following steps:

[0021] Calculating a neutron flux trend value based on the historical neutron flux according to an exponentially weighted moving average algorithm;

[0022] calculating a difference between the neutron flux trend value and the neutron flux to obtain a flux difference;

[0023] Determine whether the flux difference exceeds a preset flux difference threshold:

[0024] When exceeded, the neutron flux is invalid;

[0025] Otherwise, the neutron flux is valid.

[0026] Furthermore, the calibration parameter verification unit performs threshold verification according to the following steps:

[0027] Calculating a calibration parameter trend value based on the historical calibration parameters according to an exponentially weighted moving average algorithm;

[0028] Calculating the difference between the calibration parameter trend value and the calibration parameter to obtain the calibration difference;

[0029] Determine whether the teaching-engraving difference exceeds a preset teaching-engraving difference threshold:

[0030] When it exceeds the limit, the calibration parameters are invalid.

[0031] Otherwise, the initial calibration of the calibration parameters is valid.

[0032] Furthermore, the second verification module includes:

[0033] a boiling ratio verification unit, configured to obtain a boiling ratio fitting value by fitting the historical verification minimum deviation from nucleate boiling ratio using a polynomial fitting algorithm, and perform consistency verification between the boiling ratio fitting value and the verification minimum deviation from nucleate boiling ratio;

[0034] a density verification unit, configured to fit the local maximum linear power density of the historical verification using a polynomial fitting algorithm to obtain a linear power density fitting value, and perform a consistency check between the linear power density fitting value and the local maximum linear power density of the verification;

[0035] The verification unit is used to determine whether the calibration parameters are valid according to the consistency verification result.

[0036] Furthermore, the boiling ratio verification unit performs consistency verification according to the following steps:

[0037] Based on the historically verified minimum deviation from the nucleate boiling ratio, a polynomial fitting algorithm is used to perform fitting to obtain the boiling ratio fitting value;

[0038] Calculating a boiling ratio fitting residual between the boiling ratio fitting value and the calibration minimum deviation from the nucleate boiling ratio;

[0039] The boiling ratio fitting residual is compared with a preset boiling ratio residual threshold:

[0040] When the boiling ratio fitting residual exceeds the boiling ratio residual threshold, the verification of the minimum deviation from the nucleate boiling ratio fails the consistency verification;

[0041] Otherwise, the verified minimum deviation from nucleate boiling ratio passes the consistency check.

[0042] Furthermore, the density verification unit performs consistency verification according to the following steps:

[0043] Based on the historical verification of the local maximum linear power density, a polynomial fitting algorithm is used to perform fitting to obtain the linear power density fitting value;

[0044] Calculating the linear power density fitting residual between the linear power density fitting value and the local maximum linear power density of the calibration;

[0045] Compare the linear power density fitting residual with the preset linear power density residual threshold:

[0046] When the linear power density fitting residual exceeds the linear power density residual threshold, the verification of the local maximum linear power density fails the consistency verification;

[0047] Otherwise, the verification of the local maximum linear power density passes the consistency verification.

[0048] Furthermore, the neutron detection equipment includes:

[0049] Neutron detection module, used to measure the neutrons in the core and obtain simulated neutron flux signals;

[0050] A signal preprocessing module is used to perform signal preprocessing on the simulated neutron flux signal to obtain the neutron flux.

[0051] Furthermore, the core protection system further includes:

[0052] A display device is used to display the neutron flux, the calibration parameters, and when the verification of the verification device is passed, the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

[0053] Furthermore, the core protection system further includes:

[0054] The warning device is used to issue a warning message when the verification device fails the verification.

[0055] A second aspect of the present invention discloses a core protection method, comprising:

[0056] Neutron detection equipment measures the neutron flux in the core;

[0057] The host computer reconstructs the core flux power according to the neutron flux to generate calibration parameters, and sends the calibration parameters to the verification device;

[0058] The verification device determines whether the calibration parameters are valid according to the neutron flux and the calibration parameters, and sends the calibration parameters to the lower computer when the calibration parameters are valid;

[0059] The lower computer calculates the minimum deviation from nucleate boiling ratio and the local maximum linear power density of the core according to the neutron flux and the calibration parameters;

[0060] A control device controls the control rods of the core according to the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

[0061] The present invention introduces a verification device between the host computer and the slave computer, specifically used to determine the validity of calibration parameters. The host computer reconstructs the core flux power based on the neutron flux, generates calibration parameters, and then sends them to the verification device. The verification device uses the neutron flux data and the calibration parameters to quickly determine the validity of the calibration parameters and sends them to the slave computer only after verification. The slave computer only needs to process the verified valid parameters, avoiding erroneous calculations based on invalid parameters. The present invention effectively improves the reliability of the calibration parameters and reduces the risk of malfunctioning of the protection function. On the one hand, parameter verification avoids unnecessary control rod insertion or power reduction caused by invalid parameters, thereby improving the unit's availability; on the other hand, parameter verification ensures that only reliable parameters trigger protection actions, thereby improving the reliability and accuracy of the protection function. Therefore, the core protection system described in the present invention, through the verification of the validity of the calibration parameters, not only improves the unit's availability, but also enhances the reliability of the core protection function, providing a more powerful guarantee for the safe operation of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0063] Figure 1 This is a schematic structural diagram of a core protection system disclosed in an embodiment of the present invention;

[0064] Figure 2It is a schematic diagram of the structure of the verification device disclosed in the embodiment of the present invention;

[0065] Figure 3 It is a flow chart of a core protection method disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0067] The terms "first," "second," and so on, in the description and claims of the present invention and the accompanying drawings are used to distinguish between different objects, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, or product comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, apparatus, or product.

[0068] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0069] See also 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:

[0070] Neutron detection equipment 100, used to measure the neutron flux in the core;

[0071] In an optional embodiment, the neutron detection device includes:

[0072] Neutron detection module, used to measure the neutrons in the core and obtain simulated neutron flux signals;

[0073] A signal preprocessing module is used to perform signal preprocessing on the simulated neutron flux signal to obtain the neutron flux.

[0074] In this optional embodiment, the neutron detection module is a key component that can monitor the neutron flux distribution in the reactor core in real time. Its operating principle is based on the interaction between neutrons and specific sensitive materials to produce measurable electrical signals. When neutrons released from the core undergo nuclear reactions with sensitive materials (such as boron and uranium) within the detection module, ionization or thermal effects are generated. By measuring the change in ionization current, voltage pulse, or thermoelectric signal, the neutron flux intensity can be calculated. The detection module in this embodiment can be a gas ionization detector, a scintillator detector, a self-powered detector, etc., and the embodiments of the present invention are not limited thereto.

[0075] The signal preprocessing module performs noise reduction and signal conditioning on the raw analog signal output by the neutron detection module. This module eliminates electromagnetic interference and high-frequency noise through hardware filtering circuits, employs a signal amplifier to adjust the gain of weak electrical signals, and then converts the analog signal into a digital quantity through an analog-to-digital converter. Temperature compensation and drift correction are implemented simultaneously during the preprocessing process to eliminate the effects of ambient temperature changes on the detector output. Digital filtering algorithms further suppress random noise, ensuring the stability and accuracy of the output signal and providing a reliable data foundation for subsequent flux calculations.

[0076] It can be seen that this optional embodiment realizes closed-loop optimization of original signal acquisition, conditioning and digital processing at the detector level by integrating the collaborative working mechanism of the neutron detection module and the signal preprocessing module, effectively improving the signal-to-noise ratio and anti-interference capability of the neutron flux measurement data, making the subsequent power reconstruction and parameter calibration have higher benchmark accuracy, strengthening the measurement reliability of the core protection system from the data source, and providing solid physical measurement guarantee for the accurate triggering of the protection logic.

[0077] The host computer 200 is configured to reconstruct the core flux power according to the neutron flux to generate calibration parameters, and send the calibration parameters to a verification device;

[0078] In an optional embodiment, the calibration parameters include: current recombination correction parameters, the ratio of the component hot rod integrated power to the hot spot integrated power, the hot spot line power density corresponding to the neutron detection height and the final state parameters of the neutron detection device.

[0079] In this optional embodiment, the current composite correction parameter is used to compensate for the composite loss of the output current signal of the neutron detection equipment during transmission and the measurement deviation caused by the ambient temperature, by dynamically correcting the linear relationship between the detector output and the neutron flux; the ratio of the component hot rod integrated power to the hot spot integrated power represents the power distribution relationship between the hot rod area in the fuel assembly and the overall hot spot area of ​​the core, reflecting the uniformity characteristics of the core power spatial distribution; the hot spot line power density corresponding to the neutron detection height refers to the local maximum line power density value of the fuel rod corresponding to the axial height position of the detector, which is used to calibrate the potential hot spot position in the three-dimensional power distribution of the core; the final state parameters of the neutron detection equipment include a set of detector steady-state response parameters after multi-dimensional correction, covering the detector sensitivity calibration value, temperature compensation coefficient and long-term operation drift correction, to ensure the consistency of the neutron flux measurement data with the physical state of the core.

[0080] Verification device 300, for determining whether the calibration parameters are valid based on the neutron flux and the calibration parameters, and sending the calibration parameters to a lower computer when the calibration parameters are valid;

[0081] In an optional embodiment, the verification device 300 includes:

[0082] Storage module 310, for storing historical neutron flux, historical calibration parameters, historical minimum deviation from nucleate boiling ratio and historical local maximum linear power density;

[0083] A first verification module 320 is configured to verify the neutron flux to determine whether the neutron flux is valid; and to perform an initial verification on the calibration parameters to determine whether the initial verification of the calibration parameters is valid;

[0084] a calculation module 330 for calculating and verifying a minimum deviation from nucleate boiling ratio and a local maximum linear power density based on the neutron flux and the calibration parameters when the neutron flux is valid and the initial calibration of the calibration parameters is valid;

[0085] The second verification module 340 is used to perform consistency verification on the verification minimum deviation from nucleate boiling ratio based on the historical verification minimum deviation from nucleate boiling ratio, and to perform consistency verification on the verification local maximum linear power density based on the historical verification local maximum linear power density. When both consistency verifications pass, it is determined that the calibration parameters are valid.

[0086] Figure 2A schematic diagram of the structure of the verification device 300 is shown. In this optional embodiment, the storage module 310 refers to the basic unit in the verification device 300 for persistently storing the core operation historical data. It records the neutron flux, historical calibration parameters, historical verification minimum deviation from nucleate boiling ratio and historical verification local maximum linear power density at different time nodes through a non-volatile storage medium, forming a data reference library that can be called by subsequent verification processes.

[0087] Neutron flux is a physical quantity that characterizes the density of the number of neutrons passing through a nuclear reactor core per unit time and per unit area, and directly reflects the intensity and power level of the core fission reaction; the minimum deviation from nucleate boiling ratio is used to measure the ability of the fuel rod surface coolant to suppress the nucleate boiling phenomenon, and its value represents the safety margin between the heat transfer state of the fuel rod surface and the critical state of nucleate boiling under the current operating conditions; the verification of the local maximum linear power density specifically refers to the maximum thermal power density per unit length generated by the fuel rod at a specific axial height position, and characterizes the thermal safety boundary of the local area of ​​the core.

[0088] It can be seen that this optional embodiment establishes a multi-level verification mechanism driven by historical data, and simultaneously implements neutron flux validity verification, calibration parameter trend verification and historical consistency comparison of calculation results before applying the calibration parameters. It can effectively identify potential risks such as abnormal detector drift and parameter calculation deviation, and reduce the probability of false triggering of protection functions due to failure of a single verification link. At the same time, the dynamic verification benchmark established by fitting historical data is used to enhance the adaptability to the continuous change process of the core state, and improve the reliability of the protection system decision-making from the dual dimensions of data integrity and logical completeness.

[0089] In an optional embodiment, the first verification module 320 includes:

[0090] a neutron flux verification unit 321 for processing the historical neutron flux based on an exponentially weighted average algorithm to obtain a neutron flux trend value, and performing a threshold verification on the neutron flux according to the neutron flux trend;

[0091] The calibration parameter checking unit 322 is used to process the historical calibration parameters based on an exponentially weighted average algorithm to obtain a calibration parameter trend value, and perform threshold verification on the calibration parameters according to the calibration parameter trend value.

[0092] In an optional embodiment, the neutron flux verification unit performs threshold verification according to the following steps:

[0093] Calculating a neutron flux trend value based on the historical neutron flux according to an exponentially weighted moving average algorithm;

[0094] calculating a difference between the neutron flux trend value and the neutron flux to obtain a flux difference;

[0095] Determine whether the flux difference exceeds a preset flux difference threshold:

[0096] When exceeded, the neutron flux is invalid;

[0097] Otherwise, the neutron flux is valid.

[0098] In an optional embodiment, the calibration parameter verification unit performs threshold verification according to the following steps:

[0099] Calculating a calibration parameter trend value based on the historical calibration parameters according to an exponentially weighted moving average algorithm;

[0100] Calculating the difference between the calibration parameter trend value and the calibration parameter to obtain the calibration difference;

[0101] Determine whether the teaching-engraving difference exceeds a preset teaching-engraving difference threshold:

[0102] When it exceeds the limit, the calibration parameters are invalid.

[0103] Otherwise, the initial calibration of the calibration parameters is valid.

[0104] 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 is to assign weight coefficients that decay exponentially over time to data at different time points, giving more weight to recent data on the trend value. This effectively smooths out random fluctuations while preserving the overall trend characteristics of the data. When calculating trend values ​​based on the exponentially weighted moving average algorithm, the decay coefficient is first set to determine the weight decay rate. Then, the historical data is weighted and summed point by point in the time series. The final output trend value can reflect the smooth variation of the data over time.

[0105] The setting of the flux difference threshold and the teaching 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 amplitude under normal operating conditions in long-term operation data, and then they are corrected according to the safety margin design indicators of the core protection system to ensure that the threshold can effectively capture abnormal deviations and avoid misjudgment due to excessive sensitivity.

[0106] In the above optional embodiment, 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 the core operating parameters. Compared with the fixed threshold verification method, this method avoids false alarms caused by normal core power regulation or slowly changing operating conditions by dynamically adjusting the trend reference value. At the same time, it remains sensitive to sudden abnormal fluctuations through the difference threshold mechanism, reducing the impact of noise interference on the verification results while ensuring verification sensitivity. By comparing real-time measurement values ​​with the dynamic trend baseline generated based on historical data, the neutron flux verification unit can effectively identify abnormal conditions such as sudden detector failures, signal transmission anomalies, or local core power distortion, prevent verification misjudgments caused by sudden changes in single measurement values, and improve 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 calculation model mismatch or reconstruction algorithm deviation in the calibration parameter generation process by analyzing the degree of deviation of the parameter relative to the historical trend. It ensures the validity of the calibration parameters from the dual dimensions of time continuity and spatial consistency, and provides reliable input with multi-level verification for subsequent protection calculations.

[0107] In an optional embodiment, the second verification module 340 includes:

[0108] a boiling ratio verification unit 341 for fitting the historically verified minimum deviation from nucleate boiling ratio using a polynomial fitting algorithm to obtain a boiling ratio fitting value, and performing a consistency check between the boiling ratio fitting value and the verified minimum deviation from nucleate boiling ratio;

[0109] A density verification unit 342 is configured to fit the historical local maximum linear power density using a polynomial fitting algorithm to obtain a linear power density fitting value, and perform a consistency check between the linear power density fitting value and the local maximum linear power density of the verification;

[0110] The verification unit is used to determine whether the calibration parameters are valid according to the consistency verification result.

[0111] In an optional embodiment, the boiling ratio verification unit performs consistency verification according to the following steps:

[0112] Based on the historically verified minimum deviation from the nucleate boiling ratio, a polynomial fitting algorithm is used to perform fitting to obtain the boiling ratio fitting value;

[0113] Calculating a boiling ratio fitting residual between the boiling ratio fitting value and the calibration minimum deviation from the nucleate boiling ratio;

[0114] The boiling ratio fitting residual is compared with a preset boiling ratio residual threshold:

[0115] When the boiling ratio fitting residual exceeds the boiling ratio residual threshold, the verification of the minimum deviation from the nucleate boiling ratio fails the consistency verification;

[0116] Otherwise, the verified minimum deviation from nucleate boiling ratio passes the consistency check.

[0117] In an optional embodiment, the density verification unit performs consistency verification according to the following steps:

[0118] Based on the historical verification of the local maximum linear power density, a polynomial fitting algorithm is used to perform fitting to obtain the linear power density fitting value;

[0119] Calculating the linear power density fitting residual between the linear power density fitting value and the local maximum linear power density of the calibration;

[0120] Compare the linear power density fitting residual with the preset linear power density residual threshold:

[0121] When the linear power density fitting residual exceeds the linear power density residual threshold, the verification of the local maximum linear power density fails the consistency verification;

[0122] Otherwise, the verification of the local maximum linear power density passes the consistency verification.

[0123] In the above optional embodiments, the polynomial fitting algorithm refers to a mathematical method that approximates the distribution law of given data points by constructing a polynomial function. The polynomial fitting algorithm selects a polynomial of appropriate degree and calculates its coefficients so that the overall deviation between the polynomial curve and the data points is minimized. When calculating the fitting value based on the algorithm, it is necessary to determine the order of the polynomial according to the time series characteristics of the historical data, and use the least squares method to solve the optimal coefficient combination, and then generate a fitting curve that can reflect the data change trend. Finally, the fitting value is obtained by substituting the independent variable value corresponding to the current time point (such as a timestamp or an operating cycle).

[0124] The setting of boiling ratio fitting residuals and line power density fitting residuals can integrate the statistical distribution characteristics of historical fitting residuals and the system safety tolerance. The benchmark standard deviation is usually determined by analyzing the fluctuation range of historical residuals under normal operating conditions, and then a reasonable multiplication coefficient is set according to the sensitivity requirements of the protection system to parameter deviation, so that the threshold can not only cover normal statistical fluctuations, but also effectively identify abnormal deviations beyond the expected range.

[0125] As can be seen, in the above optional embodiment, 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 laws of parameter changes. Compared with the simple threshold comparison method, this method constructs a dynamic verification benchmark through curve fitting, which can adapt to the gradual deviation of core operating parameters caused by fuel consumption changes, power regulation, etc., and reduce the probability of misjudgment due to normal parameter evolution. At the same time, residual analysis is used to quantify the degree of deviation between current parameters and historical trends, thereby enhancing the ability to identify sudden abnormal conditions. The boiling ratio verification unit uses polynomial fitting technology to trend model the historical minimum deviation nucleate boiling ratio. By analyzing the residual between the current calculated value and the fitted value, it can effectively identify protection parameter calculation deviations caused by calibration parameter distortion, such as power reconstruction errors caused by detector drift or boiling ratio mutations caused by thermal model mismatch, thereby preventing the application of incorrect calibration parameters in the protection logic. The density verification unit fits the evolution trajectory of the historical local maximum linear power density and, in conjunction with a residual threshold mechanism, verifies the rationality of the current calculated value. This allows for timely detection of linear power density distortions caused by abnormal local power distribution in fuel assemblies or distorted neutron flux measurements. This prevents the risk of protection failures due to inaccurate capture of local hotspots and enhances the integrity of the core's three-dimensional power monitoring. The verification unit simultaneously performs dual consistency checks on boiling ratio and linear power density, constructing a multidimensional verification matrix. This cross-validates the compatibility of calibration parameters across different protection calculation models, reducing the probability of missed detections associated with single-parameter verification and ensuring the overall validity of calibration parameters from a multi-physics coupling perspective.

[0126] The lower computer 400 is configured to calculate the minimum deviation from nucleate boiling ratio and the local maximum linear power density of the core according to the neutron flux and the calibration parameters;

[0127] The control device 500 is used to control the control rods of the core according to the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

[0128] In this optional embodiment, the control device obtains the minimum deviation from nucleate boiling ratio and the local maximum linear power density of the core in real time, and dynamically compares them with preset safety limits: when the minimum deviation from nucleate boiling ratio is lower than the limit or the local maximum linear 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 demand and the predetermined strategy, so as to achieve steady-state control or load tracking of the core power while maintaining the safety margin, and at the same time, the real-time change gradient of the two parameters is combined to predict the core state evolution trend, and the control rod fine-tuning action is triggered in advance to avoid potential over-limit risks, thereby achieving a dynamic balance between core safety and operating economy through a closed-loop feedback mechanism.

[0129] In an optional embodiment, the core protection system further includes:

[0130] The display device is used to display the neutron flux, the calibration parameters, and when the verification of the verification device 300 is passed, the display device 300 displays the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

[0131] It can be seen that in this optional embodiment, the display device can enable the operator to observe the dynamic changes of the core neutron flux distribution and the calibration parameters in real time, and intuitively obtain the calculation results of the key protection parameters after the verification device 300 confirms that the parameters are valid. This visualization mechanism not only enhances the information transparency of human-computer interaction, but also facilitates the operator to make auxiliary judgments on the system automatic verification results based on engineering experience. At the same time, through the historical data display backtracking function, it provides data support for operating status trend analysis and early identification of abnormal operating conditions, thereby improving the system automation level while retaining the necessary manual supervision intervention points.

[0132] In an optional embodiment, the core protection system further includes:

[0133] The warning device is used to issue a warning message when the verification device 300 fails the verification.

[0134] It can be seen that this optional embodiment actively triggers an alarm when parameter verification fails through sound and light signals or interface prompts, which can shorten the response delay of abnormal conditions and prompt operators to quickly start the preset emergency processing process, avoiding the risk of protection function degradation caused by the failure of calibration parameters to be handled in time. At the same time, through the synergy of multi-level verification and warning mechanisms, a full-process abnormality blocking capability is formed from parameter generation, verification to execution, further strengthening the depth defense characteristics of the core protection system.

[0135] See also Figure 3 As shown, Figure 3 This is a flow chart 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:

[0136] S301, neutron detection equipment measures the neutron flux in the core;

[0137] S302: The host computer reconstructs the core flux power according to the neutron flux to generate calibration parameters, and sends the calibration parameters to the verification device;

[0138] S303: The verification device determines whether the calibration parameters are valid based on the neutron flux and the calibration parameters, and sends the calibration parameters to the lower computer if they are valid.

[0139] S304: The lower computer calculates the minimum deviation from nucleate boiling ratio and the local maximum linear power density of the reactor core according to the neutron flux and the calibration parameters;

[0140] S305. A control device controls the control rods of the core according to the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

[0141] For the specific limitations on the core protection method, please refer to the limitations on the core protection system above, which will not be repeated here.

[0142] In summary, the core protection system and method disclosed in the present invention effectively improve the reliability of calibration parameters and reduce the risk of misoperation of the protection function. On the one hand, parameter verification avoids unnecessary control rod insertion or power reduction caused by invalid parameters, thereby improving the availability of the unit; on the other hand, parameter verification ensures that only reliable parameters will trigger protection actions, thereby improving the reliability and accuracy of the protection function. Therefore, the core protection system described in the present invention, through the verification of the validity of the calibration parameters, not only improves the availability of the unit, but also enhances the reliability of the core protection function, providing a more powerful guarantee for the safe operation of the reactor. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0143] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may 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 one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A core protection system, characterized in that: The system comprises: Neutron detection equipment to measure the neutron flux in the core; A host computer, configured to reconstruct the core flux power according to the neutron flux to generate calibration parameters, and send the calibration parameters to a verification device; A verification device, configured to determine whether the calibration parameters are valid based on the neutron flux and the calibration parameters, and to send the calibration parameters to a lower computer when the calibration parameters are valid; A lower computer is used to calculate the minimum deviation from nucleate boiling ratio and the local maximum linear power density of the reactor core according to the neutron flux and the calibration parameters; A control device is used to control the control rods of the core according to the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

2. A 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. A core protection system according to claim 1, characterized in that: The verification device comprises: A storage module is used to store historical neutron flux, historical calibration parameters, historical calibration minimum deviation from nucleate boiling ratio, and historical calibration local maximum linear power density; A first verification module is used to verify the neutron flux to determine whether the neutron flux is valid; and is also used to perform an initial verification on the calibration parameters to determine whether the initial verification of the calibration parameters is valid; a calculation module, configured to calculate and verify a minimum deviation from nucleate boiling ratio and a local maximum linear power density based on the neutron flux and the calibration parameters when the neutron flux is valid and the initial calibration of the calibration parameters is valid; The second verification module is used to perform consistency verification on the verification minimum deviation from nucleate boiling ratio based on the historical verification minimum deviation from nucleate boiling ratio, and to perform consistency verification on the verification local maximum linear power density based on the historical verification local maximum linear power density. When both consistency verifications pass, it is determined that the calibration parameters are valid.

4. A core protection system according to claim 3, characterized in that: The first verification module includes: a neutron flux verification unit, configured to process the historical neutron flux based on an exponentially weighted average algorithm to obtain a neutron flux trend value, and perform a 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 an exponentially weighted average algorithm to obtain a calibration parameter trend value, and perform threshold verification on the calibration parameter according to the calibration parameter trend value.

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

6. A core protection system according to claim 4, characterized in that: The calibration parameter verification unit performs threshold verification according to the following steps: Calculating a calibration parameter trend value based on the historical calibration parameters according to an exponentially weighted moving average algorithm; Calculating the difference between the calibration parameter trend value and the calibration parameter to obtain the calibration difference; Determine whether the teaching-engraving difference exceeds a preset teaching-engraving difference threshold: When it exceeds the limit, the calibration parameters are invalid. Otherwise, the initial calibration of the calibration parameters is valid.

7. A core protection system according to claim 3, characterized in that: The second verification module includes: a boiling ratio verification unit, configured to obtain a boiling ratio fitting value by fitting the historical verification minimum deviation from nucleate boiling ratio using a polynomial fitting algorithm, and perform consistency verification between the boiling ratio fitting value and the verification minimum deviation from nucleate boiling ratio; a density verification unit, configured to fit the local maximum linear power density of the historical verification using a polynomial fitting algorithm to obtain a linear power density fitting value, and perform a consistency check between the linear power density fitting value and the local maximum linear power density of the verification; The verification unit is used to determine whether the calibration parameters are valid according to the consistency verification result.

8. A core protection system according to claim 7, characterized in that: The boiling ratio verification unit performs consistency verification according to the following steps: Based on the historically verified minimum deviation from the nucleate boiling ratio, a polynomial fitting algorithm is used to perform fitting to obtain the boiling ratio fitting value; Calculating a boiling ratio fitting residual between the boiling ratio fitting value and the calibration minimum deviation from the nucleate boiling ratio; 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 verification of the minimum deviation from the nucleate boiling ratio fails the consistency verification; Otherwise, the verified minimum deviation from nucleate boiling ratio passes the consistency check.

9. A core protection system according to claim 7, characterized in that: The density verification unit performs consistency verification according to the following steps: Based on the historical verification of the local maximum linear power density, a polynomial fitting algorithm is used to perform fitting to obtain the linear power density fitting value; Calculating the linear power density fitting residual between the linear power density fitting value and the local maximum linear power density of the calibration; Compare the linear power density fitting residual with the preset linear power density residual threshold: When the linear power density fitting residual exceeds the linear power density residual threshold, the verification of the local maximum linear power density fails the consistency verification; Otherwise, the verification of the local maximum linear power density passes the consistency verification.

10. A core protection system according to claim 1, characterized in that: The neutron detection equipment includes: Neutron detection module, used to measure the neutrons in the core and obtain simulated neutron flux signals; A signal preprocessing module is used to perform signal preprocessing on the simulated neutron flux signal to obtain the neutron flux.

11. A core protection system according to any one of claims 1 to 10, characterized in that: The core protection system further includes: A display device is used to display the neutron flux, the calibration parameters, and when the verification of the verification device is passed, the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

12. A core protection system according to any one of claims 1 to 10, characterized in that: The core protection system further includes: The warning device is used to issue a warning message when the verification device fails the verification.

13. A core protection method, characterized in that: include: Neutron detection equipment measures the neutron flux in the core; The host computer reconstructs the core flux power according to the neutron flux to generate calibration parameters, and sends the calibration parameters to the verification device; The verification device determines whether the calibration parameters are valid according to the neutron flux and the calibration parameters, and sends the calibration parameters to the lower computer when the calibration parameters are valid; The lower computer calculates the minimum deviation from nucleate boiling ratio and the local maximum linear power density of the core according to the neutron flux and the calibration parameters; A control device controls the control rods of the core according to the minimum deviation from nucleate boiling ratio and the local maximum linear power density.

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