压力容器外部冷却系统流道结构和流动参数对流场的影响分析  

Influence Analysis of Flow Channel Structure and Flow Parameters on Flow Field in External Cooling System of Pressure Vessel

作　　者：张盼[1] 李聪新[1] 温丽晶[1] 胡健[1] 刘宇生[1] 

机构地区：[1]环境保护部核与辐射安全中心,北京100082

出　　处：《核安全》2017年第2期11-16,共6页Nuclear Safety

基　　金：CAP1400核安全监管重要试验验证;项目编号:2015ZX06002007-003

摘　　要：压力容器外部冷却系统是发生堆芯熔化严重事故之后为防止事故进一步恶化熔穿压力容器下封头而设置的重要安全系统。文章采用CFD软件针对第三代压水堆核电技术的压力容器下封头外部冷却系统的结构特点和运行模式进行建模,研究严重事故工况下不同入口流量和流道间隙对压力容器外部冷却系统的流动和传热特性的影响。研究表明入口流量越大,流体的平均温度越低,但流场的分布趋势是一致的;在流道的中下部区域,流体温度变化不明显,在流道的中上部区域,温度变化明显,径向温度梯度很大;流道间隙越大,流体的平均温度越低;流道间隙越窄,局部换热会强化,但流道的阻力会增加,流道结构设计的优化有利于提高压力容器下封头的安全裕度。The external cooling system of reactor pressure vessel is an important safety system for preventing further deterioration of the severe accidentto melt the pressure vessel low er headafter the severe accident happens. According to the structural features and operating mode of the pressure vessel external cooling system,the CFD softw are w as used to built model for the third-generation PWR in this article. It studys influence on the flow and heat transfer characteristics of the pressure vessel external cooling system under a severe accident,due to the different inlet flow rate and flow channel gap. It finds that the higher the inlet flow rate,the low er the average temperature of the fluid,but the flow field distribution trends are consistent; in the low er area of the flow path,the fluid temperature did not change significantly,but in the upper area of the flow path,the temperature changes significantly and radial temperature gradient is great;the greater the flow channel gap,the low er the average temperature of the fluid,the narrow er the gap of flow channel,the local heat transfer w ill strengthen,but the resistance w ill increase. So,the design optimization of flow path w ill help improving the safety margin of the pressure vessel low er head.

关 键 词：严重事故 压力容器 外部冷却系统 数值模拟 

分 类 号：TL33[核科学技术—核技术及应用]