论文部分内容阅读
压水堆核电站反应堆高位堆顶排气系统用于排出严重事故后期压力容器顶盖内聚集的不凝性气体,由于其上下游压差巨大导致排气阀开闭时管系内承受巨大的水力载荷.两相临界流下的水力载荷是本文研究的难点,作者采用瞬变流理论结合RELAP5仿真计算了瞬态水力载荷,评估了其对管系应力的影响.针对排气阀开闭时间、水封对水力载荷的影响进行对比分析,结果表明:1)水封设置方式及排气阀开闭时间是影响水力载荷的关键因素;2)去除水封或者提高水封温度、延长阀门开闭时间将会大大降低水力载荷及应力水平;3)水力载荷峰值直接影响管系最大应力,峰值越大最大应力比越大.本文研究成果对堆顶排气系统的设计及优化有重要参考价值.“,”Reactor Head Vent (RHV) system is served to discharge the accumulated non-condensable gas at the top of RPV during the post severe accident. Due to the vast pressure difference between upstream and downstream, the piping system will sustain huge hydraulic loads. Hydraulic loads under the two-phase critical flow are the difficulty of this study. This paper uses the theory of transient flow hydrodynamics and RELAP5 to calculate the transient hydraulic parameters in RHV system. Also the stress distribution is analyzed the in the piping system. Sensitivity studies are performed to see the influence of valve actuation time and cold water sealing presence upstream of the relief valves. The results show that: 1) the setting of water seal and the valve actuation time are the key factors of hydraulic loads.2) Longer valve actuation time, removal of cold water sealing or rising of water sealing temperature can significantly decrease the peak value of hydraulic loads and the maximum piping stress ratio.3) The peak value of hydraulic loads directly affect the maximum stress, the greater load will result the greater the stress ratio. This paper provides important feedback to the optimization of RHV system design.