反应性控制系统的设计是反应堆物理设计的主要内容之一。氟盐冷却高温球床堆(Pebble Bed-Fluoride salt-cooled High temperature Reactor,PB-FHR)用B4C吸收体的控制棒作为反应性控制的主要手段。所有控制棒分布于石墨反射层的孔道中,...反应性控制系统的设计是反应堆物理设计的主要内容之一。氟盐冷却高温球床堆(Pebble Bed-Fluoride salt-cooled High temperature Reactor,PB-FHR)用B4C吸收体的控制棒作为反应性控制的主要手段。所有控制棒分布于石墨反射层的孔道中,其空间布局、几何结构、中子吸收体的特性参数等是影响控制棒反应性控制的关键因素。本文基于SCALE6程序,以10 MW固态燃料钍基熔盐堆(Thorium Molten Salt Reactor-Solid Fuel,TMSR-SF1)(属于PB-FHR)设计模型为参考,系统研究了石墨反射层中控制棒径向位置、有效行程、棒体结构、吸收体长度、吸收体密度等因素对控制棒价值的影响。结果表明,控制棒的径向位置对控制棒价值影响较大;控制棒吸收体长度需综合考虑上下限位及极限下插限位对价值变化的影响;^(10)B的原子密度变化对控制棒价值影响较小。本研究为PB-FHR的反应性控制系统的设计及控制棒的制造加工提供理论参考。展开更多
For designing and optimizing the reactor core of modular pebble-bed fluoride salt-cooled high-temperature reactor(PB-FHR),it is of importance to simulate the coupled fluid and particle flow due to strong coolantpebble...For designing and optimizing the reactor core of modular pebble-bed fluoride salt-cooled high-temperature reactor(PB-FHR),it is of importance to simulate the coupled fluid and particle flow due to strong coolantpebble interactions.Computational fluid dynamics and discrete element method(DEM) coupling approach can be used to track particles individually while it requires a fluid cell being greater than the pebble diameter.However,the large size of pebbles makes the fluid grid too coarse to capture the complicated flow pattern.To solve this problem,a two-grid approach is proposed to calculate interphase momentum transfer between pebbles and coolant without the constraint on the shape and size of fluid meshes.The solid velocity,fluid velocity,fluid pressure and void fraction are mapped between hexahedral coarse particle grid and tine fluid grid.Then the total interphase force can be calculated independently to speed up computation.To evaluate suitability of this two-grid approach,the pressure drop and minimum fluidization velocity of a fluidized bed were predicted,and movements of the pebbles in complex flow field were studied experimentally and numerically.The spouting fluid through a central inlet pipe of a scaled visible PB-FHR core facility was set up to provide the complex flow field.Water was chosen as Liquid to simulate the molten salt coolant,and polypropylene balls were used to simulate the pebble fuels.Results show that the pebble flow pattern captured from experiment agrees well with the simulation from two-grid approach,hence the applicability of the two-grid approach for the later PB-FHR core design.展开更多
To carry out accurate burnup calculations for a pebble-bed fluoride-salt-cooled high-temperature reactor,the energy-dependent cross-sectional model based on the Doppler broadening rejection correction method has been ...To carry out accurate burnup calculations for a pebble-bed fluoride-salt-cooled high-temperature reactor,the energy-dependent cross-sectional model based on the Doppler broadening rejection correction method has been proposed to develop the energy-dependent elastic scattering cross-sectional model. In this study, the Monte Carlo continuous energy code PSG2/Serpent was used to examine the difference between the constant cross-sectional model and the energy-dependent cross-sectional model during burnup. For the cases analyzed in this study,numerical simulations show that the multiplication coefficient was improved by hundreds pcm and ^(239)Pu concentration was improved by approximately 1–2% during burnup when the energy-dependent elastic scattering crosssectional model is considered.展开更多
球床式氟盐冷却高温堆(Pebble Bed Fluoride-salt Cooled High Temperature Reactor,PB-FHR)是一种先进的第四代反应堆。三维堆芯热工水力程序能够模拟具有复杂空间效应的工况,但计算耗时较高。图形处理器(Graphics Processing Unit,GPU...球床式氟盐冷却高温堆(Pebble Bed Fluoride-salt Cooled High Temperature Reactor,PB-FHR)是一种先进的第四代反应堆。三维堆芯热工水力程序能够模拟具有复杂空间效应的工况,但计算耗时较高。图形处理器(Graphics Processing Unit,GPU)具有大量计算单元,可有效提高程序的计算速度。本文研发了GPU加速的PB-FHR堆芯热工水力程序(GPU-accelerated Thermal Hydraulic Code,GATH),采用非热平衡多孔介质模型建立堆芯物理模型,研究并实现了GPU高速求解算法。对PB-FHR的堆芯模型进行了热工水力分析,与商用计算流体力学软件ANSYS CFX的计算结果进行了对比,验证了程序的正确性。GPU加速性能分析的结果表明,程序整体的加速比率可达8.39倍,证明所研发的GPU求解算法能有效提升堆芯热工水力分析的计算效率。展开更多
文摘反应性控制系统的设计是反应堆物理设计的主要内容之一。氟盐冷却高温球床堆(Pebble Bed-Fluoride salt-cooled High temperature Reactor,PB-FHR)用B4C吸收体的控制棒作为反应性控制的主要手段。所有控制棒分布于石墨反射层的孔道中,其空间布局、几何结构、中子吸收体的特性参数等是影响控制棒反应性控制的关键因素。本文基于SCALE6程序,以10 MW固态燃料钍基熔盐堆(Thorium Molten Salt Reactor-Solid Fuel,TMSR-SF1)(属于PB-FHR)设计模型为参考,系统研究了石墨反射层中控制棒径向位置、有效行程、棒体结构、吸收体长度、吸收体密度等因素对控制棒价值的影响。结果表明,控制棒的径向位置对控制棒价值影响较大;控制棒吸收体长度需综合考虑上下限位及极限下插限位对价值变化的影响;^(10)B的原子密度变化对控制棒价值影响较小。本研究为PB-FHR的反应性控制系统的设计及控制棒的制造加工提供理论参考。
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences(No.XD02001002)
文摘For designing and optimizing the reactor core of modular pebble-bed fluoride salt-cooled high-temperature reactor(PB-FHR),it is of importance to simulate the coupled fluid and particle flow due to strong coolantpebble interactions.Computational fluid dynamics and discrete element method(DEM) coupling approach can be used to track particles individually while it requires a fluid cell being greater than the pebble diameter.However,the large size of pebbles makes the fluid grid too coarse to capture the complicated flow pattern.To solve this problem,a two-grid approach is proposed to calculate interphase momentum transfer between pebbles and coolant without the constraint on the shape and size of fluid meshes.The solid velocity,fluid velocity,fluid pressure and void fraction are mapped between hexahedral coarse particle grid and tine fluid grid.Then the total interphase force can be calculated independently to speed up computation.To evaluate suitability of this two-grid approach,the pressure drop and minimum fluidization velocity of a fluidized bed were predicted,and movements of the pebbles in complex flow field were studied experimentally and numerically.The spouting fluid through a central inlet pipe of a scaled visible PB-FHR core facility was set up to provide the complex flow field.Water was chosen as Liquid to simulate the molten salt coolant,and polypropylene balls were used to simulate the pebble fuels.Results show that the pebble flow pattern captured from experiment agrees well with the simulation from two-grid approach,hence the applicability of the two-grid approach for the later PB-FHR core design.
基金supported by the National Natural Science Foundation of China(Nos.11675057 and 11705195)the Hunan Provincial Education Department Project of China(No.15C1176)the General Financial Grant from the China Postdoctoral Science Foundation(No.2017M622697)
文摘To carry out accurate burnup calculations for a pebble-bed fluoride-salt-cooled high-temperature reactor,the energy-dependent cross-sectional model based on the Doppler broadening rejection correction method has been proposed to develop the energy-dependent elastic scattering cross-sectional model. In this study, the Monte Carlo continuous energy code PSG2/Serpent was used to examine the difference between the constant cross-sectional model and the energy-dependent cross-sectional model during burnup. For the cases analyzed in this study,numerical simulations show that the multiplication coefficient was improved by hundreds pcm and ^(239)Pu concentration was improved by approximately 1–2% during burnup when the energy-dependent elastic scattering crosssectional model is considered.
文摘球床式氟盐冷却高温堆(Pebble Bed Fluoride-salt Cooled High Temperature Reactor,PB-FHR)是一种先进的第四代反应堆。三维堆芯热工水力程序能够模拟具有复杂空间效应的工况,但计算耗时较高。图形处理器(Graphics Processing Unit,GPU)具有大量计算单元,可有效提高程序的计算速度。本文研发了GPU加速的PB-FHR堆芯热工水力程序(GPU-accelerated Thermal Hydraulic Code,GATH),采用非热平衡多孔介质模型建立堆芯物理模型,研究并实现了GPU高速求解算法。对PB-FHR的堆芯模型进行了热工水力分析,与商用计算流体力学软件ANSYS CFX的计算结果进行了对比,验证了程序的正确性。GPU加速性能分析的结果表明,程序整体的加速比率可达8.39倍,证明所研发的GPU求解算法能有效提升堆芯热工水力分析的计算效率。
