入口效应对管内压力及含气率分布的影响研究

Study on the Influence of Inlet Effect on Pressure and Gas Void Fraction Distribution in Pipe

本文在直径80mm,高度11m的竖直管内对空气-水两相流动开展了可视化实验研究。实验的工况选取为表观气相速度J_(G)=0.03~16.53m·s^(-1),液相速度J_(G)=0.04~2.00m·s^(-1)。根据压力、压差传感器获取的数据,本文分析了入口效应对两相流动的影响。在泡状流动区域内,压力随气速的增加而下降的趋势较缓,在弹状流内下降趋势加快。在流动转变为搅动流时,压力下降趋势再次减缓。随着液速增加,各位置的压力下降由缓到急的趋势所对应的气速逐渐增大。在气速大于10m·s^(-1)时,发生了靠近入口位置的含气率突然增大的现象。随着液速增加,入口处含气率突增现象对应的气速逐渐降低。

In this paper,a visual experiment was carried out on the air-water two-phase fow in a vertical pipe with a diameter of 80 mm and a height of 11 m.The experimental condition was selected as the gas superficial velocity of 0.03<J_(G)<16.53m·s^(-1) and liquid superficial velocity of 0.04<J_(G)<2.00 m·s^(-1).Based on the data obtained by pressure and differential pressure sensors,the infuence of inlet effect on two-phase flow was analyzed.In the bubble flow region,the downward trend of pressure is slow with the increase of gas velocity,and the downward trend is faster in the slug flow.When the flow turns into churn flow,the downward trend of pressure slows down again.With the increase of liquid velocity,the gas velocity corresponding to the trend of pressure drop from slow to sharp at each position increases gradually.When the gas velocity is greater than 10 m·s^(-1),the gas void fraction near the entrance suddenly increases.With the increase of liquid velocity,the gas velocity corresponding to the gas void fraction surging phenomenon at the entrance decreases gradually.