Nuclear power plant hydrogen recombiner long-term stability test system

Abstract

The invention discloses a nuclear power plant hydrogen recombiner long-term stability test system, and relates to the technical field of nuclear power plant hydrogen recombiner stability test. Comprising a catalyst-magnetorheological fluid double-damage monitoring module, an interlocking memory type magnetorheological radiation adjusting module, a reaction energy peak value synchronous cooperation module, a hardware logic closed-loop feedback module and a damage quantitative evaluation module. According to the method, through a catalyst-magnetorheological fluid damage interlocking memory mechanism, the actual evolution process of radiation fluctuation-memory effect-collaborative damage is reproduced, and the problems that an existing system overestimates the stability of a hydrogen recombiner and misjudges unqualified products are solved; the interlocking memory coefficient K is quantified for the first time, a brand-new quantitative index is provided for the anti-radiation design of the catalyst, meanwhile, high radiation-high temperature-high pressure peak value synchronization is achieved through the dual functions of catalytic reaction energy and magnetorheological fluid, and energy consumption is reduced; the critical failure trend of the catalyst is pre-warned in advance by monitoring the fracture rate and the magnetic characteristic change of the magnetorheological fluid microcapsule.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen recombiner stability test of nuclear power plant, in particular to a long-term stability test system of hydrogen recombiner of nuclear power plant. BACKGROUND

[0002] In the operation of nuclear power plant, if the hydrogen gas released by normal leakage or accident state reaches 4% to 75% of the explosion limit, it will seriously threaten the safety. As the core safety equipment, the hydrogen recombiner catalyzes the hydrogen gas and air to generate water through platinum / palladium catalyst, and its design life needs to be consistent with the reactor, and it needs to withstand periodic complex working conditions such as low dose radiation, temperature and pressure fluctuation and high radiation impact in accident state for a long time. Nuclear radiation will cause irreversible damage to the catalyst, which will directly affect its long-term stability, so it is necessary to simulate the actual working condition through a long-term stability test system, carry out thousands to tens of thousands of hours of continuous test, and evaluate the performance of catalyst activity attenuation and structural integrity.

[0003] The existing test system mainly includes radiation simulation, gas supply, temperature control, pressure regulation and monitoring subsystems, but the core defect is that the radiation simulation adopts a constant radiation dose mode: the whole process radiation intensity is set according to the average radiation level of the nuclear power plant, only to ensure that the total dose is consistent with the cumulative dose in the design life, and its basis is that the radiation damage is one-way accumulation, and the constant radiation is equivalent to the actual fluctuating radiation when the total dose is equal.

[0004] However, the actual radiation environment of the nuclear power plant is periodic fluctuation, and the high radiation impact will cause irreversible damage to the active sites of the catalyst, and the multiple high radiation impact-low radiation recovery cycles will produce radiation memory effect: the high radiation damage cannot be recovered by the low radiation environment, and it will also accelerate the damage accumulation, resulting in that the actual activity attenuation rate of the catalyst is much faster than the constant radiation simulation result. The existing system does not consider the coupling effect of radiation fluctuation and radiation memory effect, which leads to a significant deviation between the test data and the actual operating state, overestimates the long-term stability of the hydrogen recombiner, and may cause misjudgment of unqualified products, which seriously threatens the safety of the nuclear power plant, so there is an urgent need for a test system that can accurately simulate the above complex working conditions.

[0005] In view of this, the long-term stability test system of hydrogen recombiner of nuclear power plant is provided to overcome the above problems. SUMMARY

[0006] The purpose of the present application is to provide a long-term stability test system of hydrogen recombiner of nuclear power plant to solve the problems raised in the background.

[0007] In order to solve the above technical problems, the long-term stability test system of hydrogen recombiner of nuclear power plant provided by the present application comprises a catalyst-magnetorheological fluid double-damage monitoring module, an interlocking memory type magnetorheological radiation regulation module, a reaction energy peak synchronous coordination module, a hardware logic closed loop feedback module and a damage quantification evaluation module. Each module is fixedly connected through shielded cable, data line and mechanical structure, and cooperatively completes complex working condition simulation of radiation fluctuation-memory effect-collaborative damage and stability evaluation of hydrogen recombiner; The catalyst-magnetorheological fluid double-damage monitoring module synchronously captures the damage states of the catalyst and the magnetorheological fluid and outputs an interlocking memory driving signal, the interlocking memory type magnetorheological radiation adjusting module realizes adaptive fluctuation adjustment of radiation intensity based on the driving signal, the reaction energy peak value synchronous collaboration module realizes high radiation-high temperature-high pressure peak value synchronization, the hardware logic closed loop feedback module receives the double-damage monitoring signal and controls the working condition parameters of each module, and the damage quantification evaluation module collects and stores test data and quantifies damage indicators.

[0008] Further, the catalyst-magnetorheological fluid double-damage monitoring module comprises a catalyst micro-damage monitoring unit, a magnetorheological fluid magnetic property monitoring unit and a double-damage fusion unit. The catalyst micro-damage monitoring unit is composed of a radiation-resistant ultraviolet-visible diffuse reflectance spectrometer and a micro-resistance probe array, and a comprehensive damage signal Dc of the catalyst is obtained through signal fusion, wherein C1 is a grain damage signal and C2 is a lattice damage signal; the magnetorheological fluid magnetic property monitoring unit is composed of a radiation-resistant Hall sensor and a rotary viscometer, and a comprehensive damage signal Dm of the magnetorheological fluid is obtained through signal superposition, wherein M1 is a magnetic property variation signal and M2 is a structure variation signal; the double-damage fusion unit outputs an interlocking memory driving signal S=α・Dc+β・Dm through a hardware operation circuit, and α and β are coupling coefficients with an initial value of 0.5.

[0009] Further, the interlocking memory type magnetorheological radiation adjusting module comprises a Co-60 γ-ray source, a ring-shaped radiation shielding cavity, a magnetorheological fluid, a ring-shaped electromagnetic coil and a radiation intensity detector; the ring-shaped radiation shielding cavity is a double-layer stainless steel structure, the inner layer is filled with 15L of the magnetorheological fluid, the magnetorheological fluid is composed of 85% of silicon oil, 10% of surface modified Fe3O4 magnetic particles and 5% of radiation sensitive microcapsules, the wall material of the radiation sensitive microcapsules is radiation-resistant epoxy resin E-51, the core material is 50nm Fe3O4 particles, and the rupture threshold is 10 6 Gy / h for 1 hour; the ring-shaped electromagnetic coil is wound on a silicon steel sheet core by 1000 turns of copper enameled wire, and an input current of 0-5A corresponds to an output magnetic field intensity of 50-300mT.

[0010] Further, the reaction energy peak value synchronous collaboration module comprises a funnel-shaped test cavity, a magnetorheological fluid pressure valve, a gas supply subsystem and auxiliary monitoring elements. The funnel-shaped test cavity is made of stainless steel and wrapped with an aluminum silicate heat insulation layer outside; the magnetorheological fluid pressure valve core is a magnetorheological fluid sealed cavity, the valve opening degree is synchronously controlled with the magnetic field intensity of the annular electromagnetic coil, the opening degree is 80% when the magnetic field is 50 mT, and the opening degree is 20% when the magnetic field is 300 mT; the gas supply subsystem maintains the hydrogen volume concentration at 3% by a mass flow controller; auxiliary monitoring elements include a hydrogen concentration sensor, a temperature sensor and a pressure sensor, which monitor the hydrogen concentration, temperature and pressure parameters in the test cavity, respectively.

[0011] Further, the hardware logic closed-loop feedback module integrates a signal conditioning circuit, a double-damage fusion circuit, a threshold comparison circuit, a magnetic field driving circuit, a pressure valve driving circuit, a memory locking unit and a microcapsule rupture counting unit; the threshold comparison circuit presets a threshold S0=0.05V, and outputs a high level when S≥S0 to trigger the subsequent circuit to act; the memory locking unit is composed of a 555 timer to form a monostable circuit, and the timing time is 3 hours; the microcapsule rupture counting unit calculates the rupture rate by integrating the magnetic permeability change rate signal, and when the rupture rate≥80%, the coupling coefficient α is corrected to 0.6 and the coupling coefficient β is corrected to 0.4.

[0012] Further, the damage quantification evaluation module includes a data acquisition card, an industrial SD card storage unit and a hardware solidification algorithm unit; the hardware solidification algorithm unit is composed of an FPGA chip, and the solidified quantification algorithm includes: catalyst activity attenuation rate=(initial reaction rate-real-time reaction rate) / initial reaction rate×100%, interlocking memory coefficient K=Dc growth rate of the nth high radiation / Dc growth rate of the first high radiation, and synergistic damage coefficient η=Dc growth rate under synchronous working condition / Dc growth rate under single radiation working condition.

[0013] Further, in terms of mechanical connection, the annular radiation shielding cavity is fixed to the center inside the funnel-shaped test cavity through a support, the Co-60 γ-ray source is fixed to the center of the annular radiation shielding cavity, the distance between the catalyst catalytic plate and the ray source is 100 mm, and the metal shells of each module are fixed to the test bench through bolts; in terms of electrical connection, all signal transmissions adopt RVVP-2×0.75 type shielded cables, the power supply adopts a 24V direct current stabilized power supply, and all circuits are provided with 5A fuse overcurrent and overvoltage protection.

[0014] Further, the test cycle of the system includes an initial low radiation stage, a high radiation-synergistic working condition stage and a memory maintenance-low radiation stage, and the cycle triggering condition is that the interlocking memory driving signal S≥S0; the test result determination standard is that the catalyst activity attenuation rate≤25%, the interlocking memory coefficient K≤2.0, the synergistic damage coefficient η≤1.5, and the catalyst plate cracking length<5 mm and the shedding area<1%; and the unqualified standard is that the activity attenuation rate>25% or K>2.0 or η>2.2, or the catalyst plate cracking length≥5 mm, or the shedding area≥1%.

[0015] Compared with the prior art, the present application has the following advantages: By the catalyst-magneto-rheological fluid damage interlocking memory mechanism, the actual evolution process of radiation fluctuation-memory effect-cooperative damage is accurately reproduced, the defect of overestimating stability of the existing system is solved, and misjudgment of unqualified products is avoided.

[0016] Accurate quantification of interlocking memory effect: for the first time, interlocking memory coefficient K is proposed and quantified, which directly reflects the damage amplification degree caused by catalyst-medium coupling, and provides a new quantitative index for catalyst radiation resistance design.

[0017] Cooperative working condition simulation without additional energy consumption: using the dual functions of catalytic reaction energy and magneto-rheological fluid, high radiation-high temperature-high pressure peak value synchronization is realized, without the need for additional heating and pressurizing equipment, and the energy consumption is reduced compared with the existing system.

[0018] Prospective damage warning: by monitoring the microcapsule breakage rate and magnetic property change of the magneto-rheological fluid, the critical failure trend of the catalyst can be warned in advance (when K≥1.8 and η≥2.0, it is determined that it is a precursor of critical failure), which provides sufficient preparation time for the operation and maintenance of nuclear power plants, and the existing system can only evaluate after the test is completed, without the function of prospective warning.

[0019] Waste into treasure of medium damage: the radiation damage (microcapsule breakage) of magneto-rheological fluid is converted into the core element of enhanced memory effect simulation, rather than simply avoiding damage, which not only simplifies the system structure (without additional memory trigger device), but also improves the test authenticity, forming a positive cycle of damage-enhancement-accurate simulation. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The figure is a schematic diagram of the long-term stability test system of the hydrogen recombiner of the nuclear power plant of the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0022] Please refer to Figure 1 , the present application provides a technical solution: The defects of the prior art are not only that radiation fluctuation is not simulated, but also that the coupling mechanism and evolution law of radiation damage are not well understood, and the deep root causes include: One-way cognitive bias of damage: Simplify the radiation damage as external energy input → passive damage accumulation of catalyst → ignore the two-way coupling mechanism of catalyst damage → environmental medium property change → subsequent damage amplification: In actual working conditions, radiation not only damages the catalyst, but also changes the physical and chemical properties of the surrounding medium (such as air and water vapor), which in turn accelerates the subsequent damage of the catalyst, forming a cycle of damage-medium variation-damage amplification. The existing system does not reproduce this coupling relationship.

[0023] Essential misjudgment of memory effect: The core of radiation memory effect is damage residue + sensitivity enhancement, and sensitivity enhancement not only comes from the lattice defects of the catalyst itself, but also from the amplification effect of the surrounding medium on radiation: the change of the microstructure of the medium after high radiation will enhance the energy transmission efficiency of subsequent radiation. The existing system only focuses on the catalyst itself and does not consider the memory effect interlocking of the medium and the catalyst.

[0024] Splitting of working condition simulation: In actual working conditions, high radiation, high temperature and high pressure are synchronous triggering synergistic damage factors, and radiation fluctuation and temperature and pressure fluctuation have peak synchronization characteristics, but the existing system adjusts each parameter separately and cannot reproduce the extreme damage scenario of peak superposition of multiple factors, resulting in insufficient authenticity of damage simulation.

[0025] Adjustment feedback lag: The existing system, even if it tries to simulate fluctuating radiation, relies on preset program control and cannot dynamically adjust the working conditions according to the real-time damage state of the catalyst, and cannot adapt to the dynamic process of damage accumulation → sensitivity change → need to adjust the radiation intensity to match the actual response.

[0026] Referring to Figure 1 The embodiment of the long-term stability test system of the hydrogen recombiner in the nuclear power plant is shown: The long-term stability test system of the hydrogen recombiner in the nuclear power plant comprises a catalyst-magnetorheological fluid double-damage monitoring module, an interlocking memory type magnetorheological radiation adjusting module, a reaction energy peak synchronization cooperation module, a hardware logic closed loop feedback module and a damage quantification evaluation module. Each module is fixedly connected through shielded cables, data lines and mechanical structures to cooperatively realize complex working condition simulation and stability evaluation. 1. Catalyst-magnetorheological fluid double-damage monitoring module: This module is used to synchronously capture the damage state of the catalyst and the magnetorheological fluid, and output interlocking memory driving signals, including a catalyst micro-damage monitoring unit, a magnetorheological fluid magnetic property monitoring unit and a double-damage fusion unit. 1.1. Catalyst micro-damage monitoring unit: In-situ UV-Vis diffuse reflectance spectrometer + micro-resistance probe array are used for cooperative monitoring. The data output ends of the two are connected to the signal input ends of the double-damage fusion unit through shielded cables.

[0027] In-situ UV-Vis diffuse reflectance spectrometer: Model UV-3600 with radiation resistance, probe head fixed outside the test cavity through the support, laser vertical focusing on the surface center of the catalyst plate, used to quantify the degree of platinum / palladium grain agglomeration, output grain damage signal C1 (voltage signal 0-5V, positively correlated with the degree of agglomeration).

[0028] Micro-resistance probe array: composed of 8 platinum-iridium alloy probes, probe diameter 0.5mm, length 10mm, spacing 10mm, evenly distributed on the ceramic substrate and fixed on both sides of the catalyst plate, connected to a high-precision resistance tester (model TH2822A, measurement range 0.01Ω-10MΩ) through wires, output lattice damage signal C2 (voltage signal 0-5V, positively correlated with the resistance change rate).

[0029] Signal fusion rule: weight calibration through pre-test (C1 accounts for 60%, C2 accounts for 40%), i.e. Dc=0.6×C1+0.4×C2, where Dc is the comprehensive damage signal of the catalyst (0-5V); pre-test calibration method: select 3 groups of platinum / palladium catalysts with different radiation damage degrees (undamaged, slightly damaged, moderately damaged), test their C1, C2 signals and the correlation with the actual damage degree (observe the grain size and lattice defect density by transmission electron microscopy), and fit to obtain the weight coefficient.

[0030] 1.2, Magneto-rheological fluid magnetic property monitoring unit: adopt radiation-resistant Hall sensor + rotary viscometer for cooperative monitoring, the data output ends of the two are connected to the signal input end of the double-damage fusion unit through shielded cable.

[0031] Radiation-resistant Hall sensor: model HMC1022, measurement range -600~+600μT, resolution 10nT, packaged in a stainless steel protective shell, fixed on the inner wall of the annular radiation shielding cavity, in contact with the magneto-rheological fluid but does not affect its flow, output magnetic property variation signal M1 (voltage signal 0-5V, positively correlated with the magnetic permeability change rate).

[0032] Rotary viscometer: model NDJ-8S with radiation resistance, equipped with RV-6 rotor (radiation-resistant coating treatment), measurement range 1-10 5 mPa・s, the rotor extends into the magneto-rheological fluid in the annular radiation shielding cavity with a depth of 50mm, output structural variation signal M2 (voltage signal 0-5V, positively correlated with the shear viscosity change).

[0033] Signal fusion rule: M1 and M2 are directly superimposed to obtain the comprehensive damage signal Dm of the magneto-rheological fluid, i.e. Dm=M1+M2 (0-10V), which is converted to 0-5V through a voltage dividing circuit and input to the double-damage fusion unit.

[0034] 1.3 Dual-damage fusion unit: The hardware operation circuit consists of an operational amplifier LM324, resistors (10kΩ, 20kΩ) and capacitors (1μF). The input terminal receives Dc (0-5V) and Dm (0-5V). The circuit realizes the operation S=α・Dc+β・Dm (α and β are coupling coefficients, both with an initial value of 0.5), and outputs an interlocked memory drive signal S (0-5V). This unit is fixed to the circuit board of the hardware logic closed-loop feedback module with screws, and the signal output terminal is connected to the signal input terminal of the hardware logic closed-loop feedback module through a shielded cable.

[0035] To verify the accurate quantification capability of the dual-damage fusion signal S for the catalyst-medium bidirectional coupling damage amplification mechanism, it is necessary to establish a correlation formula between the damage amplification factor and S, and clarify how it reflects the cyclic effect of catalyst damage → media variation → damage amplification: ; in: : Amplification factor of bidirectional coupling damage; Coupling amplification factor; Interlocked memory drive signal; Catalyst damage coupling weight; : Magnetorheological fluid (medium) variation coupling weight; : Comprehensive damage signal of catalyst; : Comprehensive damage signal of magnetorheological fluid; This formula directly quantifies the core logic of bidirectional coupling damage amplification: When there is no damage ( =0) =0), =0, =1, meaning lossless amplification; When the catalyst suffers initial damage When the value is greater than 0, it will cause changes in the properties of the magnetorheological fluid. >0, the two are connected , Weighted coupling formation This, in turn, drives the damage amplification factor. Linear growth. This indicates... It is not simply a superposition of two types of damage signals, but a precise capture of the cyclical effect of catalyst damage → medium variation → damage amplification. This proves that the dual damage monitoring module fundamentally solves the defect of the one-way cognitive bias of existing technology and provides a scientific quantitative basis for subsequent adaptive adjustment.

[0036] 2. An interlocked memory type magneto-rheological radiation regulation module: The module is used for realizing adaptive fluctuation regulation of radiation intensity, comprising a Co-60 gamma ray source, a ring-shaped radiation shielding cavity, a magneto-rheological fluid, a ring-shaped electromagnetic coil and a radiation intensity detector: 2.1. The Co-60 gamma ray source has an activity of 100 Ci and is packaged in a lead shielding shell and fixed at the center of the ring-shaped radiation shielding cavity with the ray emitting direction pointing to the outside catalyst catalytic plate.

[0037] 2.2. The ring-shaped radiation shielding cavity is made of stainless steel 316L and has a double-layer structure, wherein the inner layer cavity has a diameter of 300 mm and a thickness of 50 mm, the outer layer cavity has a diameter of 400 mm and a thickness of 30 mm, and heat insulation cotton (aluminum silicate, thickness of 20 mm) is filled between the two layers; the inner layer cavity is used for filling the magneto-rheological fluid with a filling amount of 15 L (just covering the channel between the ray source and the catalyst, and the filling height is 100 mm), the top of the cavity is provided with a liquid injection port (diameter of 20 mm), the bottom is provided with a liquid discharge port (diameter of 20 mm), and both are equipped with sealing valves.

[0038] 2.3. The preparation steps of the magneto-rheological fluid formula and preparation steps: the total mass is 10 kg, and the proportion of each component is as follows: silicone oil (model 500CS, accounting for 85%), surface modified Fe3O4 magnetic particles (accounting for 10%), and radiation sensitive microcapsules (accounting for 5%). Preparation of surface modified Fe3O4 magnetic particles: 500 nm Fe3O4 particles (purity 99.9%) are added to an ethanol solution, the stirring rate is 500 r / min, silane coupling agent KH-550 (the amount is 3% of the mass of Fe3O4) is added, the temperature is raised to 60°C and reacted for 2 h, and then the surface modified Fe3O4 particles are obtained after filtration and drying.

[0039] Preparation of radiation sensitive microcapsules: interface polymerization method is adopted, the wall material is radiation resistant epoxy resin E-51, and the core material is 50 nm Fe3O4 particles (purity 99.9%); preparation parameters: water phase is 10% epoxy resin aqueous solution, oil phase is a mixture of core material and toluene (core material accounting for 30%), emulsifier is Tween-80 (amount is 2% of the mass of the mixture), stirring rate is 800 r / min, reaction temperature is 40°C, reaction time is 3 h, and then the microcapsules with a particle size of 1-5 μm are obtained after filtration and drying, and the break threshold is 10 6 Gy / h for 1 hour.

[0040] Mixing of magneto-rheological fluid: heat the silicone oil to 40°C, add the surface modified Fe3O4 particles, stir at a rate of 600 r / min, mix for 30 min, then add the radiation sensitive microcapsules, continue to stir for 20 min, cool to room temperature, and then vacuum degassing for 1 h to obtain the finished product of magneto-rheological fluid.

[0041] 2.4, annular electromagnetic coil: 1000 turns of copper enameled wire (wire diameter 1.0 mm) is wound on a silicon steel core, the core cross-sectional size is 20 mm x 20 mm, the coil outer diameter is 350 mm, the inner diameter is 250 mm, it is fixed on the outer wall of the annular radiation shielding cavity, and is connected to the magnetic field driving circuit output end of the hardware logic closed loop feedback module through a wire, the input current is 0-5 A, and the corresponding output magnetic field strength is 50-300 mT.

[0042] 2.5, radiation intensity detector: the model FJ-377 is selected, the measurement range is 10 3 -10 7 Gy / h, the probe is fixed outside the catalyst catalytic plate, and the data output end is connected to the damage quantification evaluation module through a shielding cable, for real-time monitoring of the radiation intensity.

[0043] 3, reaction energy peak value synchronous coordination module: The module is used for realizing high radiation-high temperature-high pressure peak value synchronization, and includes a funnel-shaped test cavity, a magneto-rheological liquid pressure valve, a gas supply subsystem and a hydrogen concentration sensor. 3.1, funnel-shaped test cavity: the material is stainless steel 316L, the upper opening diameter is 200 mm, the lower opening diameter is 400 mm, the height is 500 mm, the wall thickness is 10 mm, a catalyst catalytic plate support (stainless steel material, adjustable height) is arranged in the middle of the cavity, and an aluminum silicate heat insulation layer (thickness 50 mm) is wrapped outside; a magneto-rheological liquid pressure valve mounting port is arranged at the top of the cavity, and a gas inlet and outlet and a sensor interface are arranged on the side face.

[0044] 3.2, magneto-rheological liquid pressure valve: the valve body is made of stainless steel 316L, the valve port diameter is 10 mm, the valve core is a magneto-rheological liquid sealed cavity (volume 50 mL), which is connected to the magneto-rheological liquid loop of the annular radiation shielding cavity through a pipeline, and the valve opening degree is synchronously controlled by the magnetic field strength of the annular electromagnetic coil (80% opening degree when the magnetic field is 50 mT, and 20% opening degree when the magnetic field is 300 mT); the valve is connected to a pressure relief pipeline above and is in communication with the test cavity below, and is used for adjusting the pressure (0.1-3 MPa) in the cavity.

[0045] 3.3, gas supply subsystem: composed of a hydrogen cylinder, an air cylinder, a mass flow controller (model D07-19B, range 0-10 L / min), a gas mixer and a pipeline; the hydrogen cylinder and the air cylinder are connected to the mass flow controller through pressure reducing valves, and then connected to the gas mixer (volume 1 L) through a pipeline; the control end of the mass flow controller is connected to the hardware logic closed loop feedback module through a wire, so as to maintain the hydrogen volume concentration at 3%.

[0046] 3.4, auxiliary monitoring elements: hydrogen concentration sensor (model GPR-1800), temperature sensor (model PT100), pressure sensor (model CYG1101), each 1, installed on the side interface of the test cavity, the data output end is connected to the damage quantification evaluation module through a shielded cable.

[0047] 4, hardware logic closed-loop feedback module: This module is used to receive the signals of the double-damage monitoring module, control the working condition parameters of the radiation adjustment module and the coordination module, including signal conditioning circuit, double-damage fusion circuit, threshold comparison circuit, magnetic field driving circuit, pressure valve driving circuit, memory locking unit and microcapsule rupture counting unit, each circuit is integrated on a PCB circuit board (size 200mmx150mm), fixed in the metal shell by screws: 4.1, signal conditioning circuit: composed of operational amplifier LM324, resistor (10kΩ) and capacitor (0.1μF), input end receives C1, C2, M1, M2 original signal, output 0-5V standard voltage signal, connected to double-damage fusion circuit.

[0048] 4.2, double-damage fusion circuit: the same circuit as the double-damage fusion unit of the catalyst-magnetorheological fluid double-damage monitoring module, realizes the operation of S=α・Dc+β・Dm.

[0049] 4.3, threshold comparison circuit: composed of voltage comparator LM339 and reference voltage source LM385-2.5, preset threshold S0=0.05V (corresponding to Dc=0.03V, Dm=0.02V), when S≥S0, output high level (5V), trigger the follow-up circuit action.

[0050] 4.4, magnetic field driving circuit: composed of power amplifier chip IRF540, freewheeling diode IN4007 and current limiting resistor (10Ω), input end receives the signal of threshold comparison circuit, output 0-5A adjustable current to annular electromagnetic coil, control magnetic field intensity.

[0051] 4.5, pressure valve driving circuit: linked with magnetic field driving circuit, controls the magnetorheological fluid loop switch of magnetorheological fluid pressure valve through electromagnetic relay, realizes synchronous adjustment of valve opening degree and magnetic field intensity.

[0052] 4.6, memory locking unit: monostable circuit composed of 555 timer, timing time 3 hours (parameters set by resistor 100kΩ, capacitor 100μF); when the high radiation stage ends (S growth rate < initial rate 10%), this unit maintains the high level output of the magnetic field driving circuit for 3 hours, and then restores to low level.

[0053] 4.7 Microcapsule Rupture Counting Unit: Composed of an integrating circuit (100kΩ resistor, 10μF capacitor) and a comparator, it calculates the microcapsule rupture rate by integrating the rate of change of magnetic permeability signal; when the rupture rate is ≥80%, the coupling coefficient α is corrected to 0.6 and β is corrected to 0.4 by switching the resistor network through a relay.

[0054] 5. Damage Quantitative Assessment Module: This module is used to collect, store, and analyze experimental data, and includes a data acquisition card, an industrial SD card storage unit, and a hardware-embedded algorithm unit. Data acquisition card: Model NI-DAQmx9205. The input end is connected to the data output end of each sensor and monitoring unit via a data cable, and the output end is connected to the industrial SD card storage unit via a USB interface.

[0055] Industrial SD card storage unit: 64GB capacity, supports continuous storage of 10,000 hours of test data, data format is CSV file.

[0056] Hardware-based algorithm unit: Composed of FPGA chip EP4CE6F17C8, it embeds three quantization algorithms and implements real-time calculations through hardware logic. Catalyst activity decay rate = (initial reaction rate - real-time reaction rate) / initial reaction rate × 100%; where the reaction rate is calculated by the concentration change rate of the hydrogen concentration sensor (reaction rate = ΔC / Δt, where ΔC is the change in hydrogen concentration and Δt is the time interval).

[0057] Interlocked memory coefficient = (Dc growth rate of the nth high radiation) / (Dc growth rate of the 1st high radiation). The value ranges from 0 to 5 and is positively correlated with the strength of the memory effect.

[0058] The synergistic damage coefficient η = (Dc growth rate under synchronous operating conditions) / (Dc growth rate under single radiation operating conditions), with an η value ranging from 1 to 3, and is positively correlated with the synergistic damage intensity.

[0059] Existing technologies focus only on the catalyst's own memory effect, neglecting the conduction amplification effect of the medium, while this solution... The interlocking effect of catalyst lattice defects and enhanced radiative conduction in the medium needs to be demonstrated, hence the derivation... The coupling formula with the variation of dielectric permeability: ; in: , For the first The permeability of the magnetorheological fluid after secondary radiation. The initial permeability; : No. Interlock memory coefficient of the next cycle; : No. Interlock memory coefficient for -1 cycles; : Dielectric conduction amplification factor; : No. The increase in magnetic permeability of the magnetorheological fluid after each cycle; : No. The permeability of the magnetorheological fluid after one cycle; Initial permeability of the magnetorheological fluid; This formula reveals the core physical essence of the interlocking memory coefficient K: The growth is not only due to the accumulation of lattice defects in the catalyst itself (manifested as...) (Inheritance), but more from the enhanced radiation conduction of magnetorheological fluid (medium) (manifested as) (Contribution). Following secondary radiation, the microcapsules ruptured, releasing nano-Fe3O4, which led to an increase in the magnetic permeability of the magnetorheological fluid. This enhances, and consequently improves, the energy transfer efficiency of subsequent radiation. Quantifying this reinforcing effect, ultimately driving Growth. This proves... It does not simply reflect the memory of the catalyst itself, but precisely quantifies the synergistic effect of the catalyst-medium memory interlock, solving the defect of misjudging the nature of the memory effect in existing technologies, and providing a brand-new coupled quantitative index for radiation-resistant design.

[0060] 6. Overall connection relationship: Mechanical connection: The annular radiation shielding cavity is fixed to the center of the funnel-shaped test cavity by a bracket. The Co-60 γ-ray source is fixed to the center of the annular radiation shielding cavity. The catalyst plate is fixed to the outside of the annular radiation shielding cavity by a bracket, with a distance of 100mm from the γ-ray source. The metal shells of each module are fixed to the test frame by bolts.

[0061] Electrical connections: All signal transmission uses shielded cable (model RVVP-2×0.75), the power supply uses 24V DC regulated power supply (model S-100-24), and all circuits are equipped with overcurrent and overvoltage protection (fuse specification 5A).

[0062] 7. Implementation steps: The specific steps of the hydrogen recombiner long-term stability test using the above test system are as follows, including test preparation, initial low radiation stage, high radiation-collaborative working condition stage, memory maintenance-low radiation stage, cycle test and result determination, the operation process, parameter control and judgment standard of each step are as follows: 7.1, test preparation (time-consuming 2 hours): Catalyst installation: fix the platinum / palladium series catalyst catalytic plate to be tested on the support in the middle of the funnel-shaped test cavity, ensure that the laser of the original ultraviolet-visible diffuse reflectance spectrometer is focused on the center of the catalytic plate, and the micro-resistance probe array is in good contact with the surface of the catalytic plate (contact resistance <1Ω).

[0063] Magnetorheological fluid filling: inject the prepared magnetorheological fluid through the liquid injection port at the top of the annular radiation shielding cavity, the filling amount is 15L, and the magnetorheological fluid is ensured to completely cover the channel between the radiation source and the catalytic plate (filling height 100mm), and the liquid injection port sealing valve is closed.

[0064] Gas configuration: open the pressure reducing valves of the hydrogen cylinder and the air cylinder, adjust the hydrogen flow to 0.3L / min and the air flow to 9.7L / min through the mass flow controller, so that the hydrogen volume concentration is stabilized at 3%, and the air in the test cavity is replaced for 30 minutes.

[0065] System initialization: connect the 24V DC power supply, start all modules, set the initial parameters through the debugging interface of the hardware logic closed loop feedback module: threshold S0=0.05V, memory locking time 3 hours, initial coupling coefficient α=β=0.5; calibrate each sensor through the damage quantification evaluation module, and ensure that the measurement error of radiation intensity, temperature, pressure and hydrogen concentration is ≤±2%.

[0066] 7.2, initial low radiation stage (last until S≥S0, about 100 hours): Working condition control: the hardware logic closed loop feedback module controls the annular electromagnetic coil to output a low magnetic field of 50mT, the Fe3O4 particles in the magnetorheological fluid are dispersed and distributed, the radiation intensity is maintained at 10 4 Gy / h; the gas supply subsystem continuously supplies gas to maintain the hydrogen concentration at 3%, the temperature in the test cavity is stabilized at 60-80℃, and the pressure is maintained at 0.1MPa.

[0067] Data acquisition: the catalyst-magnetorheological fluid double-damage monitoring module acquires C1, C2, M1 and M2 signals every 10 minutes, calculates Dc, Dm and interlocking memory driving signal S, and the damage quantification evaluation module synchronously acquires radiation intensity, temperature and pressure data, and stores them in real time to the industrial SD card.

[0068] 7.3, high radiation-collaborative working condition stage (last until the growth rate of Dc is less than 10% of the initial rate, about 2 hours): Trigger condition: When the hardware logic closed-loop feedback module detects that S ≥ S0, automatically trigger high radiation working condition.

[0069] Radiation regulation: The magnetic field driving circuit outputs a current of 4 A, and the annular electromagnetic coil generates a magnetic field of 250 mT, and the Fe3O4 particles in the magnetorheological fluid form a chain structure; at the same time, the high radiation (10 6 Gy / h) triggers part of the microcapsule to break, and the core material nano Fe3O4 particles are released and adsorbed on the surface of the chain structure, the magnetic permeability of the magnetorheological fluid is improved, and the radiation intensity is stabilized at 10 6 Gy / h.

[0070] Synergistic working condition formation: The catalytic reaction rate increases sharply (the initial reaction rate ≥ 0.05% / min), and the heat generated in the cavity forms natural convection, and the temperature rises to 380℃ within 30 minutes; the pressure fluctuates to 2.8 MPa under the combined action of the decrease in the number of gas molecules and the increase in temperature, realizing the synchronization of high radiation-high temperature-high pressure peak.

[0071] Data monitoring: The double-damage monitoring module collects signals every 5 minutes, tracks the growth of Dc and Dm, and until the growth rate of Dc decreases to 8% of the initial high radiation stage (the initial rate is the average growth rate of the first 10 minutes).

[0072] 4, Memory maintenance-low radiation stage (last for 3.5 hours): Working condition switching: After the high radiation stage ends, the memory locking unit is started, and the 250 mT magnetic field is maintained for 3 hours, and then the current of the magnetic field driving circuit is reduced to 1 A, and the magnetic field is restored to 50 mT.

[0073] Working condition parameters: Since the microcapsules have been broken, the magnetic permeability of the magnetorheological fluid is still higher than the initial state, and the radiation intensity is maintained at 1.5×10 4 Gy / h; the temperature slowly decreases to 90℃ through natural heat dissipation, and the pressure is released to 0.1 MPa through the magnetorheological fluid pressure valve.

[0074] Memory effect verification: Monitor the change of Dc signal, if the fluctuation amplitude of Dc within 3 hours is ≤±0.02V, it is determined that the radiation memory effect simulation is effective, and at the same time, the first interlocking memory coefficient K1=1 (reference value) is calculated.

[0075] 5, Cycle test and quantitative evaluation (cumulative duration 10000 hours): Cycle trigger: Repeat steps 3-4, and the condition of each high radiation trigger is S ≥ S0, and after each high radiation, new microcapsules in the magnetorheological fluid are broken, the magnetic response is continuously strengthened, and the low radiation baseline is gradually improved (1.5×10 4 Gy / h→2×10 4 Gy / h→…→3×10 4 Gy / h).

[0076] Coefficient correction: When the microcapsule breakage rate ≥ 80% (calculated by the integral of the magnetic susceptibility change rate, i.e. breakage rate = (real-time magnetic susceptibility - initial magnetic susceptibility) / (maximum magnetic susceptibility - initial magnetic susceptibility) x 100%), the hardware logic closed-loop feedback module automatically corrects the coupling coefficients a = 0.6, β = 0.4.

[0077] Data processing: The damage quantification evaluation module calculates the activity attenuation rate, interlocking memory coefficient K and synergistic damage coefficient η in real time, generates a stage curve every 100 hours, and stops after 10,000 hours of cumulative test.

[0078] 6. Results determination: After the test, the catalyst catalytic plate is taken out for structural integrity detection (whether there is cracking, falling off by naked eye observation), combined with the data of the damage quantification evaluation module, the following standard is determined: Qualified standard: catalyst activity attenuation rate ≤ 25%, interlocking memory coefficient K ≤ 2.0, synergistic damage coefficient η ≤ 1.5, and no obvious structural damage (cracking length < 5mm, falling area < 1%) of the catalyst plate.

[0079] Unqualified standard: activity attenuation rate > 25% or K > 2.0 or η > 2.2, or catalyst plate cracking length ≥ 5mm, or falling area ≥ 1%.

[0080] Summary: Through the catalyst-magnetorheological fluid damage interlocking memory mechanism, the actual evolution process of radiation fluctuation-memory effect-synergistic damage is accurately reproduced, the defect of overestimating the stability of the existing system is solved, and the misjudgment of unqualified products is avoided.

[0081] Accurate quantification of interlocking memory effect: for the first time, interlocking memory coefficient K is proposed and quantified, which directly reflects the damage amplification degree caused by catalyst-medium coupling, and provides a new quantitative index for catalyst radiation resistance design.

[0082] Synergistic working condition simulation without additional energy consumption: using the dual function of catalyst reaction energy and magnetorheological fluid, high radiation-high temperature-high pressure peak value is realized simultaneously, without additional heating and pressurizing equipment, and the energy consumption is reduced compared with the existing system.

[0083] Prospective damage warning: by monitoring the microcapsule breakage rate and magnetic property change of magnetorheological fluid, the critical failure trend of catalyst can be warned in advance (when K ≥ 1.8 and η ≥ 2.0, it is judged as a critical failure precursor), which provides sufficient preparation time for nuclear power plant operation and maintenance. The existing system can only evaluate after the test is completed, without prospective warning function.

[0084] The medium damage is transformed into treasure: the radiation damage (microcapsule rupture) of magnetorheological fluid is transformed into the core element of the simulation of the strengthening memory effect, instead of simply avoiding damage, which simplifies the system structure (without additional memory trigger device) and improves the test authenticity, forming a positive cycle of damage-strengthening-precision simulation.

Claims

1. A long-term stability testing system for a hydrogen recombiner in a nuclear power plant, characterized in that, It includes a catalyst-magnetorheological fluid dual damage monitoring module, an interlocked memory-type magnetorheological radiation regulation module, a reaction energy peak synchronization and coordination module, a hardware logic closed-loop feedback module, and a damage quantification assessment module. Each module is fixedly connected by shielded cables, data lines and mechanical structures, and works together to complete the simulation of complex working conditions of radiation fluctuations, memory effects and collaborative damage and the stability assessment of hydrogen recombiners. The catalyst-magnetorheological fluid dual damage monitoring module synchronously captures the damage state of the catalyst and the magnetorheological fluid and outputs an interlocked memory drive signal. The interlocked memory magnetorheological radiation regulation module realizes adaptive fluctuation regulation of radiation intensity based on the drive signal. The reaction energy peak synchronization and coordination module realizes high radiation-high temperature-high pressure peak synchronization. The hardware logic closed-loop feedback module receives the dual damage monitoring signal and controls the operating parameters of each module. The damage quantification assessment module collects and stores test data and quantifies damage indicators.

2. The long-term stability test system for a nuclear power plant hydrogen recombiner as described in claim 1, characterized in that: The catalyst-magnetorheological fluid dual damage monitoring module includes a catalyst micro-damage monitoring unit, a magnetorheological fluid magnetic property monitoring unit, and a dual damage fusion unit. The catalyst micro-damage monitoring unit consists of a radiation-resistant UV-Vis diffuse reflectance spectrometer and a micro-resistance probe array. Through signal fusion, it obtains the catalyst comprehensive damage signal Dc = 0.6 × C1 + 0.4 × C2, where C1 is the grain damage signal and C2 is the lattice damage signal. The magnetorheological fluid magnetic property monitoring unit consists of a radiation-resistant Hall sensor and a rotational viscometer. Through signal superposition, it obtains the magnetorheological fluid comprehensive damage signal Dm = M1 + M2, where M1 is the magnetic property variation signal and M2 is the structural variation signal. The dual-damage fusion unit outputs an interlocked memory drive signal S = α・Dc + β・Dm through a hardware computing circuit, where α and β are coupling coefficients with an initial value of 0.

5.

3. The long-term stability test system for a nuclear power plant hydrogen recombiner as described in claim 1, characterized in that: The interlocked memory-type magnetorheological radiation modulation module includes a Co-60 gamma-ray source, a ring-shaped radiation shielding cavity, a magnetorheological fluid, a ring-shaped electromagnetic coil, and a radiation intensity detector. The ring-shaped radiation shielding cavity is a double-layer stainless steel structure, with the inner layer filled with 15L of magnetorheological fluid. The magnetorheological fluid consists of 85% silicone oil, 10% surface-modified Fe3O4 magnetic particles, and 5% radiation-sensitive microcapsules. The wall material of the radiation-sensitive microcapsules is radiation-resistant epoxy resin E-51, the core material is 50nm Fe3O4 particles, and the rupture threshold is 10. 6 Irradiation at Gy / h for 1 hour; the toroidal electromagnetic coil is made of 1000 turns of copper enameled wire wound on a silicon steel core, with an input current of 0-5A corresponding to an output magnetic field strength of 50-300mT.

4. The long-term stability test system for a nuclear power plant hydrogen recombiner as described in claim 1, characterized in that: The reaction energy peak synchronization and coordination module includes a funnel-shaped test chamber, a magnetorheological fluid pressure valve, a gas supply subsystem, and auxiliary monitoring elements; The funnel-shaped test chamber is made of stainless steel and wrapped with an aluminum silicate insulation layer on the outside. The valve core of the magnetorheological fluid pressure valve is a magnetorheological fluid sealed chamber. The valve opening degree is synchronously controlled with the magnetic field strength of the ring electromagnetic coil. The opening degree is 80% when the magnetic field is 50mT and 20% when it is 300mT. The gas supply subsystem maintains the hydrogen volume concentration at 3% through a mass flow controller. The auxiliary monitoring elements include a hydrogen concentration sensor, a temperature sensor and a pressure sensor, which monitor the hydrogen concentration, temperature and pressure parameters in the test chamber, respectively.

5. The long-term stability test system for a nuclear power plant hydrogen recombiner as described in claim 1, characterized in that: The hardware logic closed-loop feedback module integrates signal conditioning circuit, dual-damage fusion circuit, threshold comparison circuit, magnetic field driving circuit, pressure valve driving circuit, memory locking unit and microcapsule rupture counting unit. The threshold comparison circuit has a preset threshold S0 = 0.05V. When S ≥ S0, it outputs a high level to trigger subsequent circuit actions. The memory lock unit is a monostable circuit composed of a 555 timer with a timing period of 3 hours. The microcapsule rupture counting unit calculates the rupture rate through the integral permeability change rate signal. When the rupture rate is ≥ 80%, the coupling coefficient α is corrected to 0.6 and β is corrected to 0.

4.

6. The long-term stability test system for a nuclear power plant hydrogen recombiner as described in claim 1, characterized in that: The damage quantification assessment module includes a data acquisition card, an industrial SD card storage unit, and a hardware-based algorithm unit. The hardware-based algorithm unit is composed of an FPGA chip, and the quantification algorithms include: catalyst activity decay rate = (initial reaction rate - real-time reaction rate) / initial reaction rate × 100%, interlock memory coefficient K = Dc growth rate of the nth high radiation / Dc growth rate of the 1st high radiation, and synergistic damage coefficient η = Dc growth rate under synchronous operating conditions / Dc growth rate under single radiation operating conditions.

7. The long-term stability test system for a nuclear power plant hydrogen recombiner as described in claim 1, characterized in that: In terms of mechanical connection, the annular radiation shielding cavity is fixed to the center of the funnel-shaped test cavity by a bracket, the Co-60 γ-ray source is fixed to the center of the annular radiation shielding cavity, the catalyst plate is 100mm away from the γ-ray source, and the metal shell of each module is fixed to the test frame by bolts; in terms of electrical connection, all signal transmission uses RVVP-2×0.75 shielded cable, the power supply uses 24V DC regulated power supply, and all circuits are equipped with 5A fuses for overcurrent and overvoltage protection.

8. The long-term stability test system for a nuclear power plant hydrogen recombiner as described in claim 1, characterized in that: The system's test cycle includes an initial low-radiation phase, a high-radiation-cooperative operating phase, and a memory maintenance-low-radiation phase. The cycle trigger condition is an interlock memory drive signal S≥S0. The test result judgment criteria are as follows: qualified, the catalyst activity decay rate must be ≤25%, the interlock memory coefficient K≤2.0, the cooperative damage coefficient η≤1.5, and the catalyst plate crack length <5mm and the detachment area <1%; unqualified, the activity decay rate >25%, K >2.0, or η >2.2, or the catalyst plate crack length ≥5mm, or the detachment area ≥1%.

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