引入蒸汽对垂直管内降膜蒸发传热及流动的影响

HEAT TRANSFER OF FALLING FILM IN VERTICAL TUBE WITH SUPERIMPOSED VAPOR FLOW

对垂直管内引入饱和蒸汽的湍流降膜蒸发传热及流动进行实验研究。研究结果表明:管内引入饱和蒸汽,可以在不提高液膜传热温差的情况下,提高传热系数12％～25％,降低液膜厚度10％～20％,并得出相应的计算式。

The experimental investigations of heat transfer and film flow of a turbulent falling film in a vertical tube with superimposed vapor flow were carried out. The experimental results show that the heat transfer coefficient increase in 10%-20% and the thickness of film decrease in 10%-20% with increasing vapor velocity at a constant temperature difference. A correlation is obtained to predict the heat transfer coefficient and film thickness.