Experimental Investigation on Flash Evaporation Related to Pipe Leakage

作     者：Cai, Benan Zhang, Qi Weng, Yu Gu, Hongfang Wang, Haijun 

作者机构：Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China 

出 版 物：《JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE》 

年 卷 期：2020年第6卷第1期

页      面：011401页

学科分类：08[工学] 0827[工学-核科学与技术] 

主　　题：flash evaporation high temperature and pressure relative humidity pipe leak 

摘      要：Pipelines such as the surge line and main pipe are easily subjected to thermal stratification and thermal fatigue as a result of the nonuniform temperature distribution in the nuclear power plants. When the surge line or main pipe subjected to thermal stratification and thermal fatigue keeps operating for long time, the pipe leakage may happen due to the existence of pipeline crack. When the fluids with high temperature and pressure leak in the crack, the water will evaporate quickly, which means this process belongs to spray flash evaporation process. The flash evaporation related to pipe leak was experimentally studied in the paper. The experiment was carried out under high temperature and high pressure with low spray rate. The temperature and relative humidity (T&H) variations over time were monitored in the experiment with installing T&H detectors. The T&H variations at different measurement positions and with different spray rates were analyzed, respectively. In addition, the effect of the dimensionless parameters including the Weber number and Jakob number was also investigated. Results indicated that the response speed increased with the increase of the spray flow rate. Higher Weber number and higher Jakob number led to higher evaporation rate. The slight pipe leakage can be predicted by using the (T&H) in the hazardous areas.