Online protection method, device, medium and equipment for reactor core

Abstract

The present application discloses an online protection method, device, medium and equipment for a reactor core. The method includes: obtaining the rod position information of each control rod in the reactor under the current state, and obtaining the full-core power reconstruction coefficient under the current state according to the rod position information and a preset rod state database; calculating the linear power density and departure from nucleate boiling ratio of each fuel assembly channel, and the linear power density and departure from nucleate boiling ratio of the entire reactor based on the full-core power reconstruction coefficient, detector current signal and plant operating condition signal under the current state; comparing the linear power density of each fuel assembly channel, the linear power density of the entire reactor with a preset linear power density threshold, and the departure from nucleate boiling ratio of each channel, the departure from nucleate boiling ratio of the entire reactor with a preset boiling ratio threshold, and determining and outputting a pre-protection signal and protection information. By involving the reactor power reconstruction coefficient in the calculation of protection parameters, the accuracy and reliability of the protection signal are improved, and the safety of the power plant is enhanced.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and particularly to an online protection method, device, medium and equipment for a reactor core. Background Art

[0002] A nuclear power plant is a power plant that generates electric energy by using the energy released from nuclear fission or nuclear fusion reactions. The reactor in a nuclear power plant is a device that initiates, controls, and maintains a nuclear fission or nuclear fusion chain reaction. The core is the heart of the reactor and the source of the reactor power.

[0003] During the operation of the reactor, the state of the reactor core is directly related to the reactor safety. Therefore, the state parameters of the reactor core are the most fundamental and important parameters characterizing the reactor safety. Among them, the linear power density (LPD) of the fuel assembly and the departure from nucleate boiling ratio (DNBR) are two of the most critical parameters.

[0004] When a pressurized water reactor is in operation, it is required that the core operates in the nucleate boiling heat transfer mode, at which time the heat transfer efficiency is the highest. However, when certain transients cause the local heat flux density in the reactor to increase to a certain extent, the bubbles generated on the cladding wall surface coalesce into a continuous film before leaving the wall, forming a vapor film, which increases the thermal resistance, reduces the heat transfer coefficient, causes a sharp rise in the cladding temperature, and ultimately leads to excessive fuel temperature and melting. This situation is the departure from nucleate boiling (DNB). To ensure the reactor safety, it is required in the design that the maximum heat flux density on the surface of the fuel element is less than the critical heat flux density. To quantitatively express this requirement, the departure from nucleate boiling ratio (DNBR) is introduced. To avoid excessive linear power density of the core, the linear power density (LPD) of the fuel assembly is introduced. The linear power density refers to the power borne by the fuel assembly per unit length, and it is an important parameter for measuring the power distribution of the reactor fuel assembly, which has a direct impact on the thermal-hydraulic and safe operation of the reactor.

[0005] Generally, the departure from nucleate boiling and the linear power density of the fuel assembly are calculated by using the measured current of the self-powered neutron detector of the core measurement system and the measured operating parameters of the reactor primary coolant system. The measured current of the detector and the measured operating parameters of the primary coolant system used in this method are not real-time parameters. After obtaining the measured current at a certain moment and the measured operating parameters of the coolant system, the departure from nucleate boiling and the linear power density of the fuel assembly are calculated for a period of time based on these parameters. Therefore, the accuracy of the departure from nucleate boiling and the linear power density of the fuel assembly calculated by the existing method is relatively low. Summary of the Invention

[0006] In view of this, the present invention provides an online protection method, device, medium and equipment for a reactor core, mainly aiming to solve the problem that the accuracy of the departure from nucleate boiling and the linear power density of the fuel assembly calculated by the existing method is relatively low.

[0007] According to one aspect of the present application, an online protection method for a reactor core is provided. The method includes:

[0008] Obtain the rod position information of each control rod in the reactor under the current state, and obtain the full-core power reconstruction coefficient under the current state according to the rod position information of each control rod and a preset rod state database;

[0009] Obtain the detector current signal and the power plant operating condition signal of the reactor, and calculate the linear power density of each fuel assembly channel and the linear power density of the full-core fuel assembly based on the full-core power reconstruction coefficient, the detector current signal, and the power plant operating condition signal under the current state;

[0010] Based on the power plant operating condition signal, the linear power density of each fuel assembly channel, and the linear power density of the full-core fuel assembly, calculate the departure from nucleate boiling ratio of each channel and the departure from nucleate boiling ratio of the full-core respectively;

[0011] Compare the linear power density of each channel, the linear power density of the full-core fuel assembly, and a preset linear power density threshold, determine and output a pre-protection signal and protection information of the linear power density. Compare the departure from nucleate boiling ratio of each channel, the departure from nucleate boiling ratio of the full-core, and a preset boiling ratio threshold, determine and output a pre-protection signal and protection information of the departure from nucleate boiling ratio.

[0012] Optionally, the obtaining of the full-core power reconstruction coefficient under the current state according to the rod position information of each control rod and a preset rod state database includes:

[0013] According to the rod position information of each control rod, traverse each preset rod state in the preset rod state database, and obtain two preset rod states similar to the rod position information of the control rod under the current state;

[0014] Obtain the power reconstruction coefficients of the two preset rod states, and perform interpolation calculation based on the power reconstruction coefficients of the two preset rod states to obtain the full-core power reconstruction coefficient under the current state.

[0015] Optionally, the calculating of the linear power density of each fuel assembly channel and the linear power density of the full-core fuel assembly based on the full-core power reconstruction coefficient, the detector current signal, and the power plant operating condition signal includes:

[0016] Obtain the detector current signal and the power plant operating condition signal corresponding to each channel, and obtain the power reconstruction coefficient corresponding to the node block included in each channel from the full-core power reconstruction coefficient;

[0017] Based on the power reconstruction coefficients corresponding to the fuel assemblies in each channel, the detector current signals corresponding to each channel, and the plant operating condition signals, the linear power density of the fuel assemblies in each channel is calculated by the fuel assembly weighted power calculation method.

[0018] The total detector current signal corresponding to all channels and the total plant operating condition signal are obtained. Based on the full-core power reconstruction coefficient, the total detector current signal, and the total plant operating condition signal, the linear power density of the fuel assemblies of the full core is calculated by the fuel assembly weighted power calculation method.

[0019] Optionally, the plant operating condition signals include: fuel data, cooling data, reactor inlet and outlet temperatures, pressurizer pressure, and main pump speed; based on the plant operating condition signals, the linear power density of the fuel assemblies in each channel, and the linear power density of the fuel assemblies of the full core, the departure from nucleate boiling ratio (DNBR) of each channel and the DNBR of the full core are calculated respectively, including:

[0020] The fuel data and the total cooling data are obtained. Based on the fuel data, the average fuel enrichment is calculated. Based on the total cooling data and the linear power density of the fuel assemblies of the full core, the axial hot spot distribution and the nuclear enthalpy rise factor are calculated.

[0021] Based on the average fuel enrichment, the axial hot spot distribution, the nuclear enthalpy rise factor, the total detector current signal, and the total plant operating condition signal, the core thermal power is obtained by using the physical-thermal hydraulic coupling calculation method.

[0022] The reactor inlet and outlet temperatures, pressurizer pressure, and main pump speed are obtained. Based on the reactor inlet and outlet temperatures, the pressurizer pressure, and the main pump speed, the thermal hydraulic parameters are calculated.

[0023] The cooling data of each channel is obtained. Based on the cooling data of each channel and the linear power density of the fuel assemblies, the nuclear enthalpy rise of each channel is calculated. The mass flow rate correction factor of each channel is obtained. Based on the core thermal power, the thermal hydraulic parameters, the nuclear enthalpy rise of each channel, the mass flow rate correction factor, and the boiling curve relationship, the departure from nucleate boiling ratio of each channel is calculated.

[0024] Based on the total cooling data and the linear power density of the fuel assemblies of the full core, the total nuclear enthalpy rise is calculated. The total mass flow rate correction factor is obtained. Based on the core thermal power, the thermal hydraulic parameters, the total nuclear enthalpy rise, the total mass flow rate correction factor, and the boiling curve relationship, the departure from nucleate boiling ratio of the full core is calculated.

[0025] Optionally, the preset linear power density threshold includes a first linear power density threshold and a second linear power threshold; comparing the linear power density of the fuel assemblies in each channel, the linear power density of the fuel assemblies in the whole reactor, and the preset linear power density threshold, and determining and outputting a pre-protection signal and protection information of the linear power density, including:

[0026] Performing a logical OR calculation on the linear power density of the fuel assemblies in each channel and the linear power density of the fuel assemblies in the whole reactor to obtain a first calculation result;

[0027] When the first calculation result is greater than or equal to the first linear power density threshold and less than the second linear power density threshold, output a pre-protection signal of the linear power density; when the first calculation result is greater than or equal to the second linear power density threshold, output a protection signal of the linear power density.

[0028] Optionally, the preset boiling ratio threshold includes a first boiling ratio threshold and a second boiling ratio threshold; comparing the departure nucleate boiling ratio in each channel, the departure nucleate boiling ratio in the whole reactor, and the preset boiling ratio threshold, and determining and outputting a pre-protection signal and protection information of the departure nucleate boiling ratio, including:

[0029] Performing a logical OR calculation on the departure nucleate boiling ratio in each channel and the departure nucleate boiling ratio in the whole reactor to obtain a second calculation result;

[0030] When the second calculation result is greater than or equal to the first boiling ratio threshold and less than the second boiling ratio threshold, output a pre-protection signal of the departure nucleate boiling ratio; when the second calculation result is greater than or equal to the boiling ratio threshold, output a protection signal of the departure nucleate boiling ratio.

[0031] Optionally, before obtaining the rod position information of each control rod in the reactor under the current state, the online protection method for the reactor core further includes:

[0032] Dividing the whole reactor into a plurality of grids radially and axially;

[0033] Obtaining the rod position information, detector current signal, and power plant operating condition signal corresponding to each control rod in various rod states, and based on the detector current signal and the power plant operating condition signal, using an online power distribution algorithm to obtain the power reconstruction coefficient of each grid in each rod state;

[0034] Generating a preset rod state database based on the rod position information in each rod state and the power reconstruction coefficient of each grid.

[0035] According to another aspect of the present application, there is provided an online protection device for a reactor core, including:

[0036] The full-core power reconstruction coefficient acquisition module is used to obtain the rod position information of each control rod in the reactor under the current state, and based on the rod position information of each control rod and a preset rod state database, obtain the full-core power reconstruction coefficient under the current state;

[0037] The fuel assembly linear power density calculation module is used to obtain the detector current signal and plant operating condition signal of the reactor, and based on the full-core power reconstruction coefficient under the current state, the detector current signal, and the plant operating condition signal, calculate the fuel assembly linear power density of each channel and the fuel assembly linear power density of the full core;

[0038] The departure from nucleate boiling ratio calculation module is used to calculate the departure from nucleate boiling ratio of each channel and the departure from nucleate boiling ratio of the full core respectively based on the plant operating condition signal, the fuel assembly linear power density of each channel, and the fuel assembly linear power density of the full core;

[0039] The protection signal determination module is used to compare the fuel assembly linear power density of each channel, the fuel assembly linear power density of the full core, and a preset linear power density threshold, determine and output the pre-protection signal and protection information of the linear power density, compare the departure from nucleate boiling ratio of each channel, the departure from nucleate boiling ratio of the full core, and a preset boiling ratio threshold, and determine and output the pre-protection signal and protection information of the departure from nucleate boiling ratio.

[0040] Optionally, the full-core power reconstruction coefficient acquisition module is further used for:

[0041] According to the rod position information of each control rod, traverse each preset rod state in the preset rod state database, and obtain two preset rod states similar to the rod position information of the control rod under the current state;

[0042] Obtain the power reconstruction coefficients of the two preset rod states, and perform interpolation calculation based on the power reconstruction coefficients of the two preset rod states to obtain the full-core power reconstruction coefficient under the current state.

[0043] Optionally, the fuel assembly linear power density calculation module is further used for:

[0044] Obtain the detector current signal and plant operating condition signal corresponding to each channel, and obtain the power reconstruction coefficient corresponding to the node included in each channel from the full-core power reconstruction coefficient;

[0045] Based on the power reconstruction coefficient corresponding to the node included in each channel, the detector current signal corresponding to each channel, and the plant operating condition signal, calculate the fuel assembly linear power density of each channel through the node weighted power calculation method.

[0046] Obtain the total detector current signals corresponding to all channels and the total power plant condition signals. Based on the full-core power reconstruction coefficient, the total detector current signal, and the total power plant condition signal, calculate the linear power density of the fuel assemblies of the full core through the nodal weighted power calculation method.

[0047] Optionally, the departure from nucleate boiling ratio calculation module is further configured to:

[0048] Obtain fuel data and total cooling data. Based on the fuel data, calculate the average fuel enrichment. Based on the total cooling data and the linear power density of the fuel assemblies of the full core, perform calculations to obtain the axial hot spot distribution and the nuclear enthalpy rise factor;

[0049] Based on the average fuel enrichment, the axial hot spot distribution, the nuclear enthalpy rise factor, the total detector current signal, and the total power plant condition signal, use the physical-thermal hydraulic coupling calculation method to obtain the core thermal power;

[0050] Obtain the reactor inlet and outlet temperatures, the pressurizer pressure, and the main pump speed. Based on the reactor inlet and outlet temperatures, the pressurizer pressure, and the main pump speed, calculate the thermal hydraulic parameters;

[0051] Obtain the cooling data of each channel. Based on the cooling data of each channel and the linear power density of the fuel assemblies, perform calculations to obtain the nuclear enthalpy rise of each channel. Obtain the mass flow rate correction factor of each channel. Based on the core thermal power, the thermal hydraulic parameters, the nuclear enthalpy rise of each channel, the mass flow rate correction factor, and the boiling curve relationship, calculate the departure from nucleate boiling ratio of each channel;

[0052] Based on the total cooling data and the linear power density of the fuel assemblies of the full core, perform calculations to obtain the total nuclear enthalpy rise. Obtain the total mass flow rate correction factor. Based on the core thermal power, the thermal hydraulic parameters, the total nuclear enthalpy rise, the total mass flow rate correction factor, and the boiling curve relationship, calculate the departure from nucleate boiling ratio of the full core.

[0053] Optionally, the protection signal determination module is further configured to:

[0054] Perform a logical OR calculation on the linear power density of the fuel assemblies of each channel and the linear power density of the fuel assemblies of the full core to obtain a first calculation result;

[0055] When the first calculation result is greater than or equal to the first linear power density threshold and less than the second linear power density threshold, output a pre-protection signal for the linear power density. When the first calculation result is greater than or equal to the second linear power density threshold, output a protection signal for the linear power density.

[0056] Optionally, the protection signal determination module is further configured to:

[0057] Logically OR the departure nucleate boiling ratios of each channel with the departure nucleate boiling ratio of the entire reactor core to obtain a second calculation result;

[0058] When the second calculation result is greater than or equal to the first boiling ratio threshold and less than the second boiling ratio threshold, output a pre-protection signal for the departure nucleate boiling ratio; when the second calculation result is greater than or equal to the boiling ratio threshold, output a protection signal for the departure nucleate boiling ratio.

[0059] Optionally, the online protection device for the reactor core further includes:

[0060] A preset rod state database generation module, configured to divide the entire reactor core into multiple grids radially and axially; obtain the rod position information, detector current signal, and power plant condition signal corresponding to the control rods in multiple rod states, and based on the detector current signal and the power plant condition signal, use an online power distribution algorithm to obtain the power reconstruction coefficient of each grid in each rod state; generate a preset rod state database based on the rod position information in each rod state and the power reconstruction coefficient of each grid.

[0061] According to another aspect of the present application, there is provided a storage medium storing at least one executable instruction, and the executable instruction causes a processor to perform operations corresponding to the above-mentioned online protection method for the reactor core.

[0062] According to another aspect of the present application, there is provided a computer device including: a processor, a memory, a communication interface, and a communication bus, and the processor, the memory, and the communication interface complete communication with each other through the communication bus;

[0063] The memory is used to store at least one executable instruction, and the executable instruction causes the processor to perform operations corresponding to the above-mentioned online protection method for the reactor core.

[0064] By means of the above technical solutions, the technical solutions provided by the embodiments of the present invention have at least the following advantages:

[0065] An online protection method, device, medium and equipment for a reactor core provided by the present application, which obtains the rod position information of each control rod in the reactor under the current state in real time, obtains the reactor power reconstruction coefficient under the current state according to the rod position information of each control rod, calculates according to the reactor power reconstruction coefficient under the current state, the measured detector current signal and the power plant operating condition signal, obtains the linear power density of the fuel assembly for each channel, the linear power density of the fuel assembly for the whole reactor, the departure from nucleate boiling ratio for each channel and the departure from nucleate boiling ratio for the whole reactor, realizes the protection of the reactor based on the linear power density of the fuel assembly and the departure from nucleate boiling ratio, involves the reactor power reconstruction coefficient in the calculation of protection parameters, improves the accuracy and reliability of the protection signal, and improves the safety of the power plant.

[0066] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specifically gives the specific embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. And throughout the drawings, the same reference numerals are used for the same components. In the drawings:

[0068] Figure 1 Shows a flowchart of an online protection method for a reactor core provided by an embodiment of the present application;

[0069] Figure 2 Shows a flowchart of another online protection method for a reactor core provided by an embodiment of the present application;

[0070] Figure 3 Shows a schematic diagram of the placement area of the control rods of an online protection method for a reactor core provided by an embodiment of the present application;

[0071] Figure 4 Shows a schematic diagram of the placement area of the detectors of an online protection method for a reactor core provided by an embodiment of the present application;

[0072] Figure 5 Shows a schematic diagram of the connection between the upper-layer computing device and the lower-layer computing device of an online protection method for a reactor core provided by an embodiment of the present application;

[0073] Figure 6 Shows a block diagram of the composition of an online protection device for a reactor core provided by an embodiment of the present application.

[0074] Among them,

[0075] Figure 6 Among them: 602 - full core power reconstruction coefficient acquisition module; 604 - fuel assembly linear power density calculation module; 606 - departure from nucleate boiling ratio calculation module; 608 - protection signal determination module. Specific implementation manner

[0076] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0077] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following describes in detail the specific implementation manner, structure, features and their effects of the application according to the present invention with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiments" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0078] Aiming at the problem that the accuracy of the departure from nucleate boiling and the fuel assembly linear power density calculated by the existing method is relatively low, the embodiment of the present application provides an online protection method for a reactor core, as Figure 1 shown, the method includes:

[0079] 102: Obtain the rod position information of each control rod in the reactor under the current state, and obtain the full core power reconstruction coefficient under the current state according to the rod position information of each control rod and the preset rod state database;

[0080] 104: Obtain the detector current signal and the power plant operating condition signal of the reactor, and calculate the fuel assembly linear power density of each channel and the fuel assembly linear power density of the full core based on the full core power reconstruction coefficient, the detector current signal and the power plant operating condition signal under the current state;

[0081] 106: Based on the power plant operating condition signal, the fuel assembly linear power density of each channel and the fuel assembly linear power density of the full core, calculate the departure from nucleate boiling ratio of each channel and the departure from nucleate boiling ratio of the full core respectively;

[0082] 108: Compare the fuel assembly linear power density of each channel, the fuel assembly linear power density of the full core and the preset linear power density threshold, determine and output the pre - protection signal and protection information of the linear power density, compare the departure from nucleate boiling ratio of each channel, the departure from nucleate boiling ratio of the full core and the preset boiling ratio threshold, and determine and output the pre - protection signal and protection information of the departure from nucleate boiling ratio.

[0083] Specifically, the online protection method of this application consists of two major parts: upper-layer fine calculation and lower-layer fast calculation. The upper-layer calculation compares the rod position of each control rod inserted in the reactor in the current state with a preset rod state database to obtain the full-core power reconstruction coefficient in the current state, and provides the core power reconstruction coefficient for the lower-layer protection calculation; the lower-layer calculation is responsible for collecting the micro-current of the detector and the power plant condition signals, and calculates the linear power density of each fuel assembly channel, the linear power density of the full-core fuel assemblies, the departure from nucleate boiling ratio of each channel, and the departure from nucleate boiling ratio of the full core respectively based on the full-core power reconstruction coefficient, the detector current signal, the power plant condition signals, etc. Then, it compares the linear power density of each channel, the linear power density of the full-core fuel assemblies with the preset linear power density threshold to determine the pre-protection signal and protection information of the linear power density, and compares the departure from nucleate boiling ratio of each channel, the departure from nucleate boiling ratio of the full core with the preset boiling ratio threshold to determine the pre-protection signal and protection information of the departure from nucleate boiling ratio, providing a protection basis for the reactor operation.

[0084] Compared with the prior art, an online protection method for a reactor core provided by this application can obtain the rod position information of each control rod in the reactor in real time, obtain the reactor power reconstruction coefficient in the current state according to the rod position information of each control rod, calculate based on the reactor power reconstruction coefficient in the current state, the measured detector current signal, and the power plant condition signals to obtain the linear power density of each fuel assembly channel, the linear power density of the full-core fuel assemblies, the departure from nucleate boiling ratio of each channel, and the departure from nucleate boiling ratio of the full core, and realize the protection of the reactor based on the linear power density of the fuel assembly and the departure from nucleate boiling ratio. By involving the reactor power reconstruction coefficient in the calculation of protection parameters, the accuracy and reliability of the protection signal are improved, and the safety of the power plant is enhanced.

[0085] In an embodiment of the present invention, as Figure 2 shown, obtaining the full-core power reconstruction coefficient in the current state according to the rod position information of each control rod and the preset rod state database includes:

[0086] 202: According to the rod position information of each control rod, traverse each preset rod state in the preset rod state database to obtain two preset rod states whose rod position information is close to that of the control rod in the current state;

[0087] 204: Obtain the power reconstruction coefficients of the two preset rod states, and perform interpolation calculation based on the power reconstruction coefficients of the two preset rod states to obtain the full-core power reconstruction coefficient in the current state.

[0088] Specifically, the control rods are inserted in the reactor at preset positions. For example, as Figure 3As shown in the figure. Obtain the rod position information of each control rod inserted in the reactor in the current state, that is, obtain the rod state information in the current state, traverse the preset rod state database, and obtain two preset rod states similar to the rod state information in the current state, such as two preset rod states Ri and Rj adjacent to the current rod state. Then, obtain the full-core power reconstruction coefficients of these two preset rod states, and perform interpolation according to the full-core power reconstruction coefficients corresponding to the two adjacent preset rod states to interpolate the full-core power reconstruction coefficient in the current rod state. As a preferred implementation manner of this embodiment, the mean interpolation method or the weighted interpolation method is used during interpolation.

[0089] Each preset rod state in the preset rod state database realizes fine tracking calculation of variable states based on nuclear power, boron concentration, rod position state, etc. within a set time, and obtains the full-core power reconstruction coefficient corresponding to this preset rod state.

[0090] In an embodiment of the present invention, based on the full-core power reconstruction coefficient, detector current signal, and power plant operating condition signal in the current state, the linear power density of each fuel assembly channel and the linear power density of the full-core fuel assembly are calculated, including:

[0091] Obtain the detector current signal and power plant operating condition signal corresponding to each channel, and obtain the power reconstruction coefficient corresponding to the node included in each channel from the full-core power reconstruction coefficient;

[0092] Based on the power reconstruction coefficient corresponding to the node included in each channel, the detector current signal and power plant operating condition signal corresponding to each channel, and through the node weighted power calculation method, calculate the linear power density of each fuel assembly channel;

[0093] Obtain the total detector current signal and total power plant operating condition signal corresponding to all channels, and based on the full-core power reconstruction coefficient, total detector current signal, and total power plant operating condition signal, calculate the linear power density of the full-core fuel assembly through the node weighted power calculation method.

[0094] Specifically, the detectors are arranged at preset positions to collect the current signals of the sampling points in the reactor. The arrangement positions of the detectors are as Figure 4 shown. Receive the original current signal of the in-core detector, perform primary smoothing filtering combining hardware and software, eliminate hysteresis with a correction filter, perform primary validity judgment to obtain the standard detector current signal. Collect the power plant operating condition signal and rod position signal, perform normalized signal processing, and perform validity judgment to obtain standard signals such as power plant operating conditions; according to the collected rod position signal, traverse the preset rod state database provided by the upper-layer fine calculation to obtain the full-core power reconstruction coefficient in the current state.

[0095] According to the standard detector current signal to which this channel belongs, the standard power plant operating condition signal, and the power reconstruction coefficient of the node included in this channel in the full-core power reconstruction coefficient, calculate the LPD-OWN value (linear power density of the fuel assembly of this channel) of this channel through the node weighted power calculation technology;

[0096] Synchronously utilize the standard detector current signals, standard power plant operating condition signals, and full-core power reconstruction coefficients of all channels in the full core, and calculate the LPD-AVE value (linear power density of the fuel assemblies in the full core) of each node in the full core through the node weighted power calculation technology.

[0097] In an embodiment of the present invention, the power plant operating condition signals include: fuel data, cooling data, reactor inlet and outlet temperatures, pressurizer pressure, and main pump speed; based on the power plant operating condition signals, the linear power density of the fuel assembly of each channel, and the linear power density of the fuel assemblies in the full core, calculate the departure from nucleate boiling ratio of each channel and the departure from nucleate boiling ratio of the full core respectively, including:

[0098] Obtain the fuel data and total cooling data, calculate the average fuel enrichment based on the fuel data, and calculate the axial hot spot distribution and nuclear enthalpy rise factor based on the total cooling data and the linear power density of the fuel assemblies in the full core;

[0099] Based on the average fuel enrichment, axial hot spot distribution, nuclear enthalpy rise factor, total detector current signal, and total power plant operating condition signal, use the physical-thermal hydraulic coupling calculation method to obtain the core thermal power;

[0100] Obtain the reactor inlet and outlet temperatures, pressurizer pressure, and main pump speed, and calculate the thermal hydraulic parameters based on the reactor inlet and outlet temperatures, pressurizer pressure, and main pump speed;

[0101] Obtain the cooling data of each channel, calculate the nuclear enthalpy rise of each channel based on the cooling data of each channel and the linear power density of the fuel assembly, obtain the mass flow rate correction factor of each channel, and calculate the departure from nucleate boiling ratio of each channel based on the core thermal power, thermal hydraulic parameters, nuclear enthalpy rise of each channel, mass flow rate correction factor, and boiling curve relationship;

[0102] Calculate the total nuclear enthalpy rise based on the total cooling data and the linear power density of the fuel assemblies in the full core, obtain the total mass flow rate correction factor, and calculate the departure from nucleate boiling ratio of the full core based on the core thermal power, thermal hydraulic parameters, total nuclear enthalpy rise, total mass flow rate correction factor, and boiling curve relationship.

[0103] Specifically, the average fuel enrichment refers to the average concentration of fissile materials (such as uranium-235 or plutonium-239) in nuclear fuel. The enrichment is usually expressed as a mass percentage, which is the ratio of the mass of the fissile material to the total mass of the fuel. The average fuel enrichment is an important parameter for measuring the performance of nuclear fuel and the safety of reactor operation. Obtain the mass of the fissile material and the total mass of the fuel, and calculate the average fuel enrichment.

[0104] The calculation of the axial hot spot distribution usually involves multiple steps, including data acquisition, model establishment, calculation and iteration, result analysis and display, etc. The following is a simplified calculation process:

[0105] Collect real-time data from various sensors in the reactor (such as thermocouples, detectors, etc.), including temperature, pressure, flow rate, neutron flux, etc. Establish a mathematical model of the reactor core, which usually includes the thermal-hydraulic characteristics, neutron physics characteristics of the fuel rods and their interactions. The model can be a simplified model based on empirical formulas or a more complex numerical model, such as a three-dimensional finite element model, to obtain the full-core power reconstruction coefficient in the core. Input the collected data and the full-core power reconstruction coefficient into the mathematical model, and calculate the temperature distribution and coolant density distribution in the core height direction. Since the actual operating conditions may differ from the model assumptions, iterative calculations are required to continuously adjust the model parameters to match the real-time data, obtain the temperature distribution, analyze the temperature distribution, and find the hot spot positions and temperature values in the fuel rods.

[0106] The nuclear enthalpy rise factor refers to the ratio of the nuclear enthalpy rise of the coolant passing through the core to its specific heat capacity and temperature rise. It is a dimensionless parameter used to characterize the heat exchange efficiency of the coolant, reflecting the relationship between the heat exchange efficiency of the coolant passing through the core relative to its specific heat capacity and temperature rise.

[0107] The calculation formula for the nuclear enthalpy rise factor (eta) is: eta = H / c_p / T, where: H is the nuclear enthalpy rise, c_p is the specific heat capacity of the coolant (J / kg·K), and T is the temperature rise of the coolant (K).

[0108] The nuclear enthalpy rise refers to the heat absorbed by a unit mass of coolant passing through the reactor core. It reflects the heat exchange efficiency of the coolant passing through the core. The nuclear enthalpy rise directly represents the increase in thermal energy of the coolant passing through the core. The calculation formula for the nuclear enthalpy rise (H) is: H = Q / m, where: Q is the total heat absorbed by the coolant passing through the core, obtain the flow rate of the coolant from the operating data of the reactor, use the linear power density of the fuel assembly in the channel or the whole reactor and the flow path of the coolant to calculate the total heat absorbed by the coolant passing through the core, m is the mass of the coolant (kg), and obtain the nuclear enthalpy rise of each channel or the total nuclear enthalpy rise of the whole reactor.

[0109] Based on the average fuel enrichment, axial hot spot distribution, nuclear enthalpy rise factor, total detector current signal, and total power plant condition signal, the core thermal power is obtained using a physical-thermal coupling calculation method; based on the reactor inlet and outlet temperatures, pressurizer pressure, and main pump speed, the thermal-hydraulic parameters are calculated; the calculation of the core thermal power and the calculation of the thermal-hydraulic parameters are both existing technologies and will not be elaborated here.

[0110] Based on the core thermal power, thermal-hydraulic parameters, nuclear enthalpy rise and mass flow rate correction factor of each channel, and the boiling curve relationship, the departure from nucleate boiling ratio of each channel is calculated; based on the core thermal power, thermal-hydraulic parameters, total nuclear enthalpy rise, and total mass flow rate correction factor, and the boiling curve relationship, the departure from nucleate boiling ratio of the whole reactor is calculated; the calculation of the departure from nucleate boiling ratio is an existing technology and will not be elaborated here.

[0111] In one embodiment, the preset linear power density thresholds include a first linear power density threshold and a second linear power threshold; compare the linear power density of the fuel assemblies in each channel, the linear power density of the fuel assemblies of the whole reactor, and the preset linear power density thresholds, and determine and output the pre-protection signal and protection information of the linear power density, including:

[0112] Perform a logical OR calculation on the linear power density of the fuel assemblies in each channel and the linear power density of the fuel assemblies of the whole reactor to obtain a first calculation result;

[0113] When the first calculation result is greater than or equal to the first linear power density threshold and less than the second linear power density threshold, output the pre-protection signal of the linear power density; when the first calculation result is greater than or equal to the second linear power density threshold, output the protection signal of the linear power density.

[0114] Specifically, perform a logical OR process on the linear power density of the fuel assemblies in each channel and the linear power density of the fuel assemblies of the whole reactor to obtain a calculation result, and based on the comparison result between the linear power density protection limit value and the calculation result, output the pre-protection signal and protection signal of the linear power density.

[0115] Each channel calculates the corresponding linear power density of the fuel assembly according to a certain method based on a set of detector current values received by itself; on the other hand, each channel calculates the linear power density protection limit parameters of the other 3 channels according to the detector current signal transmitted from another channel, and finally weights and averages the linear power density protection limit parameters of the 4 channels to obtain an average value, which is the protection threshold of the linear power density.

[0116] When key parameters fail due to the over-limit of the core detector failure rate, the failure of the signal processing cabinet, the failure of the measured rod position signal transmission, etc., the protection threshold of the linear power density is adaptively adjusted to ensure that the setting of the protection threshold can keep the core in a safe state.

[0117] In one embodiment, the preset boiling ratio thresholds include a first boiling ratio threshold and a second boiling ratio threshold; comparing the departure nucleate boiling ratio of each channel, the departure nucleate boiling ratio of the entire reactor, and the preset boiling ratio thresholds, and determining and outputting a pre-protection signal and protection information for the departure nucleate boiling ratio, including:

[0118] Performing a logical OR calculation on the departure nucleate boiling ratio of each channel and the departure nucleate boiling ratio of the entire reactor to obtain a second calculation result;

[0119] When the second calculation result is greater than or equal to the first boiling ratio threshold and less than the second boiling ratio threshold, output a pre-protection signal for the departure nucleate boiling ratio; when the second calculation result is greater than or equal to the boiling ratio threshold, output a protection signal for the departure nucleate boiling ratio.

[0120] Specifically, perform a logical OR operation on the departure nucleate boiling ratio of each channel and the departure nucleate boiling ratio of the entire reactor to obtain a calculation result, and based on the comparison result between the boiling ratio protection limit value and the calculation result, output a pre-protection signal and a protection signal for the boiling ratio.

[0121] Each channel calculates the corresponding departure nucleate boiling ratio according to a certain method based on a set of detector current values received by itself; on the other hand, each channel calculates the boiling ratio protection limit parameters of the other 3 channels according to the detector current signals transmitted from another channel, and finally weights and averages the boiling ratio protection limit parameters of the 4 channels to obtain an average value, which is used as the protection threshold for the boiling ratio.

[0122] When critical parameters fail due to over-limited core detector failure rate, signal processing cabinet failure, actual measured rod position signal transmission failure, etc., adaptively adjust the protection threshold for the boiling ratio to ensure that the setting of the protection threshold can keep the core in a safe state.

[0123] In one embodiment, before obtaining the rod position information of each control rod in the reactor under the current state, the online protection method for the reactor core further includes:

[0124] Dividing the entire reactor into multiple grids radially and axially;

[0125] Obtaining the rod position information, detector current signals, and plant operating condition signals corresponding to each control rod in multiple rod states, and based on the detector current signals and plant operating condition signals, using an online power distribution algorithm to obtain the power reconstruction coefficient of each grid in each rod state;

[0126] Generating a preset rod state database based on the rod position information in each rod state and the power reconstruction coefficient of each grid.

[0127] Specifically, in a preset rod state, after dividing the entire reactor core into several grids radially and axially, the fine power peak factor, assembly power distribution, power conversion coefficient from detector current to assembly block (calculated from theoretical power distribution and theoretical current), detector theoretical current, hottest rod power factor, etc. of each grid are calculated based on the detector current signal, power plant operating condition signal, etc. in this rod state. Based on the fine power peak factor, assembly power distribution, power conversion coefficient from detector current to assembly block, detector theoretical current, hottest rod power factor, etc. of each grid, the power reconstruction coefficient of each grid is calculated, and the power reconstruction coefficient of the entire reactor core in this rod state is obtained. The upper-level system regularly calculates the power reconstruction coefficient of the entire reactor core in each rod state through an online power distribution algorithm based on small grids and regularly transmits it to the rod state database.

[0128] The power reconstruction coefficients of multiple preset rod states are obtained through the above method.

[0129] The rod state database undergoes multiple verifications before being used for lower-level protection calculations: at the upper level, redundant two different algorithms are run on different platforms to verify the fine calculation results, verification is carried out in the fast monitoring calculation link, verification is carried out in the fast protection calculation link, and verification is carried out by comparing the fast monitoring calculation and the fast protection calculation, ensuring the reliability of the signal calculation for protection.

[0130] In one embodiment, as Figure 5 shown, it consists of two major parts: upper-level fine calculation and lower-level fast calculation. The upper-level system (non-safety level) realizes upper-level fine calculation, and the lower-level system (safety level) realizes lower-level fast calculation, taking into account both the response time and accuracy of the protection channel.

[0131] The upper-level fine calculation mainly performs core physics simulation calculations (including simulator calculations, detector theoretical current calculations, measured power of the detector layer, power distribution of the detector layer assemblies, axial power distribution of the core fuel assemblies, three-dimensional fine power of the core, calculation of parameters such as LPD and DNBR, etc.) and uses the simulator to calculate the multi-rod state database according to the preset rod state.

[0132] The cabinet for running the lower-level fast protection calculation is designed to be of safety level, and the 4-channel method is adopted to ensure the redundancy of the protection signal. The upper-level fine calculation updates the parameters required for the lower-level protection calculation regularly or irregularly to ensure the consistency between the calculation result of the protection signal and the core state. The information between the upper and lower levels of the system is fully interacted, and at the same time, the isolation requirements between the safety level and the non-safety level are strictly ensured.

[0133] The core detectors and the core quadrant topology of the control rods are redundantly arranged in the core regionally. The signal of each protection channel can represent the core state information of the entire reactor core, ensuring the redundancy of the protection signal. On the premise that 1 or 2 protection channels fail, the LPD / DNBR protection function can still be executed.

[0134] The reconstruction parameters for LPD / DNBR protection signal calculation have undergone multiple calibration verifications: cross-verification of two sets of refined calculation algorithms / platforms in the upper layer, verification of the upper-layer fast monitoring calculation, verification of the lower-layer protection calculation, and cross-verification between the upper-layer fast monitoring calculation and the lower-layer protection calculation. The quadruple redundant calibration method ensures the reliability and accuracy of the protection signal calculation.

[0135] The system adopts a highly reliable network design: information interaction between 4 cabinets in the lower layer is carried out through a redundant ring network, data transmission between the lower layer and the upper layer in the upstream direction is through a redundant unidirectional network, data transfer such as the reconstruction parameters between the upper layer and the lower layer in the downstream direction is achieved through the maintenance network. The downstream maintenance network design ensures high-reliability transmission while meeting the requirements of sufficient signal interaction and isolation. The entire network architecture ensures high-reliability information transmission and strictly implements the isolation criterion.

[0136] Furthermore, as an implementation of the method shown above Figure 1 The embodiment of the present invention provides an on-line protection device for a reactor core, as Figure 6 shown, the device includes:

[0137] The full-core power reconstruction coefficient acquisition module 602 is used to acquire the rod position information of each control rod in the reactor under the current state, and obtain the full-core power reconstruction coefficient under the current state according to the rod position information of each control rod and the preset rod state database;

[0138] The fuel assembly linear power density calculation module 604 is used to acquire the detector current signal and the power plant operating condition signal of the reactor, and calculate the fuel assembly linear power density of each channel and the fuel assembly linear power density of the full core based on the full-core power reconstruction coefficient, the detector current signal, and the power plant operating condition signal under the current state;

[0139] The departure from nucleate boiling ratio calculation module 606 is used to calculate the departure from nucleate boiling ratio of each channel and the departure from nucleate boiling ratio of the full core respectively based on the power plant operating condition signal, the fuel assembly linear power density of each channel, and the fuel assembly linear power density of the full core;

[0140] The protection signal determination module 608 is used to compare the fuel assembly linear power density of each channel, the fuel assembly linear power density of the full core, and the preset linear power density threshold, determine and output the pre-protection signal and protection information of the linear power density, compare the departure from nucleate boiling ratio of each channel, the departure from nucleate boiling ratio of the full core, and the preset boiling ratio threshold, and determine and output the pre-protection signal and protection information of the departure from nucleate boiling ratio.

[0141] The present application provides an on-line protection device for a reactor core. Compared with the prior art, it can obtain the rod position information of each control rod in the reactor in real time, obtain the reactor power reconstruction coefficient in the current state according to the rod position information of each control rod, calculate based on the reactor power reconstruction coefficient in the current state, the measured detector current signal, and the power plant operating condition signal, obtain the linear power density of the fuel assembly for each channel, the linear power density of the fuel assembly for the whole reactor, the departure from nucleate boiling ratio for each channel and the departure from nucleate boiling ratio for the whole reactor, and realize the protection of the reactor based on the linear power density of the fuel assembly and the departure from nucleate boiling ratio. By involving the reactor power reconstruction coefficient in the calculation of protection parameters, the accuracy and reliability of the protection signal are improved, and the safety of the power plant is enhanced.

[0142] In one embodiment, the whole-reactor power reconstruction coefficient acquisition module is further configured to:

[0143] According to the rod position information of each control rod, traverse each preset rod state in the preset rod state database, and obtain two preset rod states that are close to the rod position information of the control rod in the current state;

[0144] Obtain the power reconstruction coefficients of the two preset rod states, and perform interpolation calculation based on the power reconstruction coefficients of the two preset rod states to obtain the whole-reactor power reconstruction coefficient in the current state.

[0145] In one embodiment, the linear power density calculation module of the fuel assembly is further configured to:

[0146] Obtain the detector current signal and the power plant operating condition signal corresponding to each channel, and obtain the power reconstruction coefficient corresponding to the node included in each channel from the whole-reactor power reconstruction coefficient;

[0147] Based on the power reconstruction coefficient corresponding to the node included in each channel, the detector current signal corresponding to each channel, and the power plant operating condition signal, calculate the linear power density of the fuel assembly for each channel through the node weighted power calculation method;

[0148] Obtain the total detector current signal and the total power plant operating condition signal corresponding to all channels, and calculate the linear power density of the fuel assembly for the whole reactor through the node weighted power calculation method based on the whole-reactor power reconstruction coefficient, the total detector current signal, and the total power plant operating condition signal.

[0149] In one embodiment, the departure from nucleate boiling ratio calculation module is further configured to:

[0150] Obtain the fuel data and the total cooling data, calculate the average fuel enrichment based on the fuel data, and calculate based on the total cooling data and the linear power density of the fuel assembly for the whole reactor to obtain the axial hot spot distribution and the nuclear enthalpy rise factor;

[0151] Based on the average fuel enrichment, axial hot spot distribution, nuclear enthalpy rise factor, total detector current signal, and total power plant condition signal, the core thermal power is obtained by using a physical-thermal hydraulic coupling calculation method;

[0152] Obtain the inlet and outlet temperatures of the reactor, the pressurizer pressure, and the main pump speed. Based on the inlet and outlet temperatures of the reactor, the pressurizer pressure, and the main pump speed, the thermal hydraulic parameters are calculated;

[0153] Obtain the cooling data of each channel. Based on the cooling data of each channel and the linear power density of the fuel assembly, the nuclear enthalpy rise of each channel is calculated. Obtain the mass flow rate correction factor of each channel. Based on the core thermal power, thermal hydraulic parameters, nuclear enthalpy rise of each channel, mass flow rate correction factor, and boiling curve relationship of each channel, the departure from nucleate boiling ratio of each channel is calculated;

[0154] Based on the total cooling data and the linear power density of the fuel assemblies of the whole reactor, the total nuclear enthalpy rise is calculated. Obtain the total mass flow rate correction factor. Based on the core thermal power, thermal hydraulic parameters, total nuclear enthalpy rise, total mass flow rate correction factor, and boiling curve relationship, the departure from nucleate boiling ratio of the whole reactor is calculated.

[0155] In one embodiment, the protection signal determination module is further configured to:

[0156] Perform a logical OR calculation on the linear power density of the fuel assemblies of each channel and the linear power density of the fuel assemblies of the whole reactor to obtain a first calculation result;

[0157] When the first calculation result is greater than or equal to the first linear power density threshold and less than the second linear power density threshold, output a pre-protection signal for the linear power density. When the first calculation result is greater than or equal to the second linear power density threshold, output a protection signal for the linear power density.

[0158] In one embodiment, the protection signal determination module is further configured to:

[0159] Perform a logical OR calculation on the departure from nucleate boiling ratio of each channel and the departure from nucleate boiling ratio of the whole reactor to obtain a second calculation result;

[0160] When the second calculation result is greater than or equal to the first boiling ratio threshold and less than the second boiling ratio threshold, output a pre-protection signal for the departure from nucleate boiling ratio. When the second calculation result is greater than or equal to the boiling ratio threshold, output a protection signal for the departure from nucleate boiling ratio.

[0161] In one embodiment, the on-line protection device for the reactor core further includes:

[0162] A preset rod state database generation module is used to divide the entire reactor core into multiple grids radially and axially; obtain the rod position information, detector current signals, and plant operating condition signals corresponding to the control rods in multiple rod states, and based on the detector current signals and plant operating condition signals, use an online power distribution algorithm to obtain the power reconstruction coefficients of each grid in each rod state; generate a preset rod state database based on the rod position information in each rod state and the power reconstruction coefficients of each grid.

[0163] According to an embodiment of the present invention, a storage medium stores at least one executable instruction, and the computer executable instruction can execute the online protection method for the reactor core in any of the above method embodiments.

[0164] A computer device according to an embodiment of the present invention, and the specific embodiments of the present invention do not limit the specific implementation of the computer device.

[0165] The computer device may include: a processor, a communication interface, a memory, and a communication bus.

[0166] Wherein: the processor, the communication interface, and the memory complete mutual communication through the communication bus.

[0167] The communication interface is used to communicate with network elements of other devices such as clients or other servers.

[0168] The processor is used to execute a program, and specifically can execute the relevant steps in the above-mentioned online protection method embodiment of the reactor core.

[0169] Specifically, the program may include program code, and the program code includes computer operation instructions.

[0170] The processor may be a central processing unit CPU, or a specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention. One or more processors included in the computer device may be of the same type of processor, such as one or more CPUs; or may be of different types of processors, such as one or more CPUs and one or more ASICs.

[0171] The memory is used to store the program. The memory may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk memory.

[0172] The program can specifically be used to cause a processor to execute the online protection method for a reactor core in any of the above method embodiments.

[0173] Obviously, those skilled in the art should understand that the various modules or steps of the present invention described above can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. In one embodiment, they can be implemented by program code executable by a computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order from here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module to implement. In this way, the present invention is not limited to any specific combination of hardware and software.

[0174] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the essence and protection scope of the present application, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present application.

Claims

1. An online protection method for a reactor core, characterized in that, Including: Obtain the rod position information of each control rod in the reactor under the current state, and obtain the full-core power reconstruction coefficient under the current state according to the rod position information of each control rod and a preset rod state database; Obtain the detector current signal and plant operating condition signal of the reactor, and calculate the linear power density of the fuel assembly for each channel and the linear power density of the fuel assembly of the full core based on the full-core power reconstruction coefficient, the detector current signal, and the plant operating condition signal under the current state; Based on the plant operating condition signal, the linear power density of the fuel assembly for each channel, and the linear power density of the fuel assembly of the full core, calculate the departure from nucleate boiling ratio for each channel and the departure from nucleate boiling ratio of the full core respectively; Compare the linear power density of the fuel assembly for each channel, the linear power density of the fuel assembly of the full core, and a preset linear power density threshold, determine and output a pre-protection signal and protection information for the linear power density, compare the departure from nucleate boiling ratio for each channel, the departure from nucleate boiling ratio of the full core, and a preset boiling ratio threshold, and determine and output a pre-protection signal and protection information for the departure from nucleate boiling ratio; Calculating the linear power density of the fuel assembly for each channel and the linear power density of the fuel assembly of the full core based on the full-core power reconstruction coefficient, the detector current signal, and the plant operating condition signal under the current state, including: Obtain the power reconstruction coefficient corresponding to the node included in each channel, the detector current signal corresponding to each channel, and the plant operating condition signal, and calculate the linear power density of the fuel assembly for each channel through a node weighted power calculation method based on the power reconstruction coefficient corresponding to the node included in each channel, the detector current signal corresponding to each channel, and the plant operating condition signal; Obtain the total detector current signal corresponding to all channels and the total plant operating condition signal, and calculate the linear power density of the fuel assembly of the full core through a node weighted power calculation method based on the full-core power reconstruction coefficient, the total detector current signal, and the total plant operating condition signal; The plant operating condition signal includes: fuel data, cooling data, reactor inlet and outlet temperatures, pressurizer pressure, and main pump speed; calculating the departure from nucleate boiling ratio for each channel and the departure from nucleate boiling ratio of the full core respectively based on the plant operating condition signal, the linear power density of the fuel assembly for each channel, and the linear power density of the fuel assembly of the full core, including: Calculate the core thermal power and thermal-hydraulic parameters based on the plant operating condition signal; Obtain the cooling data for each channel, calculate the nuclear enthalpy rise for each channel based on the cooling data for each channel and the linear power density of the fuel assembly, obtain the mass flow rate correction factor for each channel, and calculate the departure from nucleate boiling ratio for each channel based on the core thermal power, thermal-hydraulic parameters, the nuclear enthalpy rise for each channel, the mass flow rate correction factor, and the boiling curve relationship; Calculate the total nuclear enthalpy rise based on the total cooling data and the linear power density of the fuel assembly of the full core, obtain the total mass flow rate correction factor, and calculate the departure from nucleate boiling ratio of the full core based on the core thermal power, thermal-hydraulic parameters, the total nuclear enthalpy rise, the total mass flow rate correction factor, and the boiling curve relationship.

2. The online protection method for a reactor core as claimed in claim 1, wherein Obtaining the full-core power reconstruction coefficient in the current state according to the rod position information of each control rod and a preset rod state database includes: According to the rod position information of each control rod, traversing each preset rod state in the preset rod state database to obtain two preset rod states whose rod position information is similar to that of the control rod in the current state; Obtaining the power reconstruction coefficients of the two preset rod states, and performing interpolation calculation based on the power reconstruction coefficients of the two preset rod states to obtain the full-core power reconstruction coefficient in the current state.

3. The online protection method for a reactor core as claimed in claim 1, characterized in that, The obtaining the power reconstruction coefficient corresponding to the node block included in each channel includes: Obtaining the power reconstruction coefficient corresponding to the node block included in each channel from the full-core power reconstruction coefficient.

4. The online protection method for a reactor core as claimed in claim 1, wherein, The calculating the core thermal power and thermohydraulic parameters based on the plant operating condition signals includes: Obtaining fuel data and total cooling data, calculating the average fuel enrichment based on the fuel data, and calculating the axial hot spot distribution and nuclear enthalpy rise factor based on the total cooling data and the linear power density of the fuel assemblies in the whole reactor; Based on the average fuel enrichment, the axial hot spot distribution, the nuclear enthalpy rise factor, the total detector current signal and the total plant operating condition signal, using a physical-thermohydraulic coupling calculation method to obtain the core thermal power; Obtaining the reactor inlet and outlet temperatures, the pressurizer pressure and the main pump speed, and calculating the thermohydraulic parameters based on the reactor inlet and outlet temperatures, the pressurizer pressure and the main pump speed.

5. The online protection method for a reactor core according to claim 1, characterized in that, The preset linear power density thresholds include a first linear power density threshold and a second linear power density threshold; comparing the linear power density of the fuel assemblies in each channel, the linear power density of the fuel assemblies in the whole reactor and the preset linear power density thresholds, and determining and outputting the pre-protection signal and protection information of the linear power density includes: Performing a logical OR calculation on the linear power density of the fuel assemblies in each channel and the linear power density of the fuel assemblies in the whole reactor to obtain a first calculation result; When the first calculation result is greater than or equal to the first linear power density threshold and less than the second linear power density threshold, outputting the pre-protection signal of the linear power density; when the first calculation result is greater than or equal to the second linear power density threshold, outputting the protection signal of the linear power density.

6. The online protection method for a reactor core as claimed in claim 1, wherein, The preset boiling ratio thresholds include a first boiling ratio threshold and a second boiling ratio threshold; comparing the departure from nucleate boiling ratio in each channel, the departure from nucleate boiling ratio in the whole reactor and the preset boiling ratio thresholds, and determining and outputting the pre-protection signal and protection information of the departure from nucleate boiling ratio includes: Performing a logical OR calculation on the departure from nucleate boiling ratio in each channel and the departure from nucleate boiling ratio in the whole reactor to obtain a second calculation result; When the second calculation result is greater than or equal to the first boiling ratio threshold and less than the second boiling ratio threshold, outputting the pre-protection signal of the departure from nucleate boiling ratio; when the second calculation result is greater than or equal to the boiling ratio threshold, outputting the protection signal of the departure from nucleate boiling ratio.

7. The online protection method for a reactor core according to any one of claims 1-6, characterized in that, Before obtaining the rod position information of each control rod in the reactor in the current state, the online protection method for the reactor core further includes: Dividing the whole reactor into a plurality of grids radially and axially; Obtain the rod position information, detector current signal, and plant operating condition signal corresponding to the control rods in various rod states respectively. Based on the detector current signal and the plant operating condition signal, use the online power distribution algorithm to obtain the power reconstruction coefficient of each grid in each rod state. Generate a preset rod state database based on the rod position information and the power reconstruction coefficient of each grid in each rod state.

8. An on-line protection device for a reactor core, characterized in that, Include: A full-core power reconstruction coefficient acquisition module, which is used to obtain the rod position information of each control rod in the reactor in the current state, and obtain the full-core power reconstruction coefficient in the current state according to the rod position information of each control rod and the preset rod state database. A fuel assembly linear power density calculation module, which is used to obtain the detector current signal and the plant operating condition signal of the reactor, and calculate the linear power density of each fuel assembly channel and the linear power density of the whole reactor based on the full-core power reconstruction coefficient, the detector current signal, and the plant operating condition signal in the current state. A departure from nucleate boiling ratio calculation module, which is used to calculate the departure from nucleate boiling ratio of each channel and the departure from nucleate boiling ratio of the whole reactor respectively based on the plant operating condition signal, the linear power density of each channel, and the linear power density of the whole reactor. A protection signal determination module, which is used to compare the linear power density of each channel, the linear power density of the whole reactor, and a preset linear power density threshold, determine and output the pre-protection signal and protection information of the linear power density, compare the departure from nucleate boiling ratio of each channel, the departure from nucleate boiling ratio of the whole reactor, and a preset boiling ratio threshold, and determine and output the pre-protection signal and protection information of the departure from nucleate boiling ratio. The fuel assembly linear power density calculation module is further used for: Obtain the power reconstruction coefficient corresponding to the node block included in each channel, the detector current signal and the plant operating condition signal corresponding to each channel, and calculate the linear power density of each fuel assembly channel through the node block weighted power calculation method based on the power reconstruction coefficient corresponding to the node block included in each channel, the detector current signal and the plant operating condition signal corresponding to each channel. Obtain the total detector current signal and the total plant operating condition signal corresponding to all channels, and calculate the linear power density of the whole reactor through the node block weighted power calculation method based on the full-core power reconstruction coefficient, the total detector current signal, and the total plant operating condition signal. The plant operating condition signal includes: fuel data, cooling data, reactor inlet and outlet temperature, pressurizer pressure, and main pump speed. The departure from nucleate boiling ratio calculation module is further used for: Calculate the core thermal power and thermohydraulic parameters based on the plant operating condition signal. Obtain the cooling data of each channel, calculate the nuclear enthalpy rise of each channel based on the cooling data of each channel and the linear power density of the fuel assembly, obtain the mass flow rate correction factor of each channel, and calculate the departure from nucleate boiling ratio of each channel based on the core thermal power, thermohydraulic parameters, nuclear enthalpy rise of each channel, mass flow rate correction factor, and boiling curve relationship. Based on the total cooling data and the linear power density of the fuel assemblies in the whole reactor, calculations are carried out to obtain the total nuclear enthalpy rise, and the total mass flow rate correction factor is obtained. Based on the core thermal power, thermohydraulic parameters, total nuclear enthalpy rise, total mass flow rate correction factor and boiling curve relation formula, the departure from nucleate boiling ratio of the whole reactor is calculated.

9. A storage medium in which at least one executable instruction is stored, and the executable instruction causes the processor to perform the operations of the online protection method for the reactor core according to any one of claims 1-7.

10. A computer device, comprising: A processor, a memory, a communication interface and a communication bus, and the processor, the memory and the communication interface complete communication with each other through the communication bus; The memory is used to store at least one executable instruction, and the executable instruction causes the processor to perform the corresponding operations of the online protection method for the reactor core according to any one of claims 1-7.

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