Experimental investigation on the dynamic characteristics of molten droplets and high-temperature particles falling in coolant
This paper presents the dynamic characteristics of molten droplets and hot particles at the very beginning of their falling into coolant pools, which are of importance to the subsequent interactions such as fragmentation of the droplets in coolants. The falling course of a single droplet or a single hot particle was recorded by a high-speed camera and a curve of velocity vs. time was obtained. Emphasis was placed on the effects of the droplets size and temperature, the coolants temperature and properties, and the droplets physical properties on the moving behavior. Tests with hot particles were also performed for a comparison with the droplets. The results for the all cases showed that the velocity of a falling droplet/particle decreased rapidly but rebounded shortly, at the beginning of droplet/particle falling in the coolant. Following such a V-shaped evolution in velocity, the droplet/particle slows down gradually till a comparatively steady velocity. An increase in either coolant temperature or droplet temperature results in a larger velocity variation in the J-region, but a smaller deceleration after it moves out of the Jregion. The elevated volatility of a coolant leads to a steeper deceleration in the J-region and beyond. The bigger size of a particle leads to a greater velocity variation in the J-region and terminal velocity. A high melting point and thermal conductivity as well as lower heat capacity contribute to dramatic variation in the J-region and low terminal velocity.
droplet movement characteristics fuel and coolant interactions multiphase flow
L.X.Li H.X.Li T.K.Chen W.M.Ma
Nuclear Power Safety Division, Royal Institute of Technology, Sweden State Key Laboratory of Multiphase Flow, Xian Jiaotong University, China
国际会议
西安
英文
292-299
2009-07-11（万方平台首次上网日期，不代表论文的发表时间）