乏燃料池非能动分离式热管冷却系统CFD仿真研究

Simulation Study of CFD in Passive Cooling System with Loop Thermosyphons in Spent Fuel Pool

乏燃料水池的非能动冷却系统是保证全厂断电事故工况下核电站安全性的关键。本文基于分离式热管,研究了新型乏燃料池完全非能动冷却系统的冷却能力,运用商业CFD软件对乏燃料达到19 MW衰变热工况下水池内冷却剂的流动特性进行数值模拟,分析了乏燃料池内的流场和温度场,根据计算结果对热管管束各排间的对流换热强度进行对比。结果表明:水池内最高水温349K,最高流速0.23m/s,不会发生沸腾;热管外壁面对流换热表面热系数随高度的降低而减小,横向冲刷管束部分略有增大。完全非能动冷却系统能够有效带走衰变热,保证乏燃料池在事故工况下的安全性。

The passive cooling system of spent fuel pool(SFP) is the key factor to assure the security of nuclear power station under the condition of station blackout. A new complete passive cooling system applying split heat pipes are proposed and numerical simulation method are used to analyze the temperature and velocity distribution of the SFP by commercial software. The simulation results show that water in the SFP doesn’t boil because the highest temperature of the water is 349 K and the highest velocity is 0.23 m/s. The convective surface heat transfer coefficient of the heat pipe exterior surface is decreased with the decreasing height and increased slightly in the cross-flow area. The decay heat of spent fuel is taken away successfully by the passive cooling system and the inherent safety is ensured under the station blackout condition.