某型空间堆堆芯热工水力特性数值分析

Numerical Analysis of Thermal Hydraulic Characteristics for a Space Reactor Core

本工作对某型空间堆堆芯内部热工水力不均匀特性进行了数值分析,针对不同工况下空间堆堆芯内部流动和传热特性尝试采用核热耦合方法进行数值模拟计算,首先使用六角形变分节块法三维全堆芯中子学扩散计算得到堆芯功率分布参数,然后对堆芯进行三维建模并导入商用CFD软件STAR-CCM+进行计算。数值模拟过程中,分析了稳态条件下堆芯径向功率分布不均匀性对内部流动和传热的影响规律;同时分析了当落棒事故发生时,堆芯轴向功率分布不均匀性对流场的影响规律。本研究基于核热耦合技术初步计算得到上述工况下的堆芯流体温度、速度、堆内最高温度点等参数分布,经过对计算结果的分析,获得了稳态工况及落棒事故工况下堆芯内部流动传热情况以及温度和速度三维分布的不均匀特性。

This work attempts to analyze the thermal-hydraulic non-uniformity characteristics of a space reactor core,and numerically calculates the internal flow and heat transfer characteristics of the space reactor core under different operating conditions based on the nuclear-thermal coupling method,the core power distribution parameters were obtained by three-dimensional full core neutron simulation with diffusion hexagonal variation nodal method.Then the reactor core was modeled and imported into commercial CFD software STAR-CCM+.In the numerical simulation,the influence of nonuniform distribution of core radial power on internal flow and heat transfer under steady conditions were analyzed.And the influence of nonuniform distribution of core axial power on the flow field in the control rod drop accident is analyzed.In this study,the distribution of parameters such as temperature and velocity of the core flow field under the above conditions were preliminary calculated through the coupling calculation of neutronics and thermal-hydraulics.Upon analyzing the results,the non-uniform characteristics of the three-dimensional distribution of temperature,velocity and maximum temperature in the core under steady state conditions and rod drop accident conditions were obtained.