压水堆上腔室冷却剂温度振荡现象研究

为了解压水堆上腔室冷却剂的温度振荡现象，利用专业计算软件CFX，采用大涡模拟（LES）方法，对简化上腔室内的瞬态流场进行数值模拟，并与实际数据进行对比分析。结果表明，LES模型可较好地模拟上腔室的温度振荡现象；上腔室出口区域的温度波动多集中于低频部分，未呈现出明显的周期性；出口位置对流场温度分布有明显影响，自入口至上腔室出口中心线所在平面，外围及中心部分温度波动幅度较大，其余区域温度变化幅度较小；而自上腔室出口中心线所在平面至顶部区域，温度波动逐渐趋缓。

Analysis of Coolant Temperature Fluctuating in Upper Plenum of PWR

Based on large eddy simulation (LES) turbulence model, the transient flowing field in the upper plenum of PWR was simulated to obtain the coolant temperature fluctuating. The results show that temperature fluctuating phenomenon can be obtained effectively by the LES model, and the large temperature fluctuation is more concentrated in the low frequency part without apparent period at the exit of the upper plenum. The temperature distribution is more influenced by the exit position, from the entrance to the middle plane corresponding to the center line of upper plenum exit, and the temperature fluctuating amplitude is larger at the peripheral and central section than at other regions. The whole temperature fluctuating slows down gradually from the middle plane to the top.