TOPAZ-Ⅱ空间核反应堆电源辐射屏蔽优化措施影响分析

Analysis on Influence of Optimal Measures for Radiation Shielding in TOPAZ-ⅡSpace Nuclear Reactor Power

空间核反应堆辐射屏蔽可减弱中子与γ光子通量对仪器设备的辐照,温度是影响辐射屏蔽性能的重要因素。利用Fluent软件对TOPAZ-Ⅱ空间核反应堆电源辐射屏蔽在真空环境下的换热行为进行了数值模拟,提出了优化措施,并揭示了优化措施对其温度场的影响和其温度分布特性。研究结果表明:冷却剂管道及其管槽表面喷涂低发射率的涂层具有均匀辐射屏蔽温度场和降低其温度峰值的效果,最优化参数为管道表面涂层的发射率为0.1~0.3、管槽表面涂层的发射率为0.1,且管道表面喷涂低发射率涂层效果要优于管槽;在冷却剂管道、管槽间添加单层表面发射率为0.04~0.07的真空遮热板也可使辐射屏蔽温度场与温度峰值处于最优状态。

The radiation shielding of space nuclear reactors can reduce the radiation of neutron and gamma photon fluxes to instruments and equipments.It is one of the key components of the power supply of space nuclear reactors.The temperature is an important factor affecting the performance of radiation shielding.The Fluent software was used to numerically simulate the heat transfer behavior of the TOPAZ-Ⅱspace nuclear reactor power supply radiation shield in a vacuum environment.The optimization measures were proposed.And the influence of the optimization measures on the temperature field and its temperature distribution characteristics were revealed.The research results show that the low-emissivity coating sprayed on the surface of the coolant pipe and its pipe groove has the effect of uniform radiation shielding the temperature field and reducing its temperature peak.The optimal parameters are the emittance of the coating on the pipe surface between 0.1 and 0.3,and the emittance of the coating on the pipe groove around 0.1.And the effect of spraying low emissivity coating on the pipe surface is better than that of the pipe groove.In addition,a single layer of vacuum heat shield with surface emissivity of 0.04-0.07 can be added between the coolant pipes and grooves to optimize the radiation shielding temperature field and peak temperature.