超临界状态的流体从超临界状态向次临界状态的泄压过程,对超临界水冷堆(SCWR)的安全有非常重要的影响。本文通过相似性原理及模化方法,利用临界点较低的氟利昂(R134a)代替水对超临界水冷堆的泄压过程进行了实验研究。泄压过程分别从容器顶部和底部进行,实验集中观测了超临界态流体泄压过程中压力和温度的瞬态变化。实验分析了流体初始状态、泄压孔直径对泄压过程的影响。在等熵泄压过程中观测到工质从超临界状态进入次临界状态时,两相开始产生的压力和温度主要取决于初始状态及泄压的速率。在等熵泄压过程实验中未观测到容器内工质中形成明显的轴向温度分布。
The depressurization process of supercritical water has a significant influence on the safety of SCWR.The paper carried out the experimental study of the top and bottom vented blowdown processes of supercritical freon(R134a).The investigation focuses on pressure and temperature transients.The effect of initial fluid conditions,orifice diameter on depressurization behavior was experimentally analyzed.During the isentropic change,it is observed that the pressure at which two phases appear depends mainly on the initial fluid condition and depressurization mass flow rate.There is almost no axial temperature gradient during the isentropic process.