低压自然循环间歇泉流动不稳定性实验研究与RELAP5程序验证

对低压条件下自然循环回路内的两相间歇泉流动不稳定性进行了实验研究。同时，对RELAP5/MOD3.2程序计算低压自然循环间歇泉流动不稳定的可行性进行了验证分析。实验结果表明，低压条件下，间歇泉流动不稳定产生的根本原因在于有效驱动压头的周期性变化，与加热段内气液两相流动的形成-消失周期密切相关。下降段内流体温度越高，波动周期越短。实验数据与RELAP5/MOD3.2程序模拟计算结果符合较好，说明RELAP5/MOD3.2程序对模拟计算低压条件下自然循环间歇泉流动不定稳性具有较好的适用性。

Validation of REALP5 Code for Simulation of Geyser Flow Instability Under Low Pressure Natural Circulation Condition

The two-phase geyser flow instability under low pressure natural circulation condition was researched experimentally. Using the experimental data, the RELAP5 code for the simulation geyser flow instability was also verified. The experimental results show that the period variety of effective driving pressure head induces the occurring of flow oscillation phenomena. The higher the fluid temperature in the downcomer is, the shorter the fluctuation period is. When the fluid temperature reaches saturation value, the fluctuation period keeps constant. Compared with the experimental data, the calculated magnitude and frequency of the temperature and flow rate oscillations reproduced well. Therefore, the RELAP5/MOD3.2 software is able to model the geyser flow instability under low pressure natural circulation condition.