竖直多孔管降膜蒸发传热实验

Heat transfer experiment of falling-film evaporation in vertical porous tube

研究了内表面烧结型多孔管对降膜蒸发换热效果的影响。采用单管降膜蒸发器,由壳程的蒸汽加热管程的水降膜传热。在热通量q=13~90 k W·m^(-2),传热温差ΔT=2.87~9.5℃,液体Reynolds数ReL=4500~15000范围内,求不同工况下管内降膜传热系数,并将其与相对应的光管换热性能进行比较。比较数据可知:多孔管的管内降膜传热系数是光管的2.03倍,总传热系数是光管的1.78倍,多孔管强化传热效果明显。

This paper presents the effect of internal sintered porous tube on the falling-film evaporation heat transfer coefficients. The experiment was performed with a single-tube evaporator, using steam in the shell to heat water in the tube. The falling-film evaporation heat transfer coefficients were calculated under various conditions with heat flux from 13 k W·m^（-2） to 90 k W·m^（-2）, heat transfer temperature difference from 2.87℃ to 9.5℃, and liquid Reynolds number from 4500 to 15000. The experimental results with a smooth tube are compared to those with an internal sintered porous tube. The results show that the falling-film evaporation heat transfer coefficients of an internal sintered porous tube are 2.03 times that of smooth tube, while the overall heat transfer coefficients are 1.78 times. The enhancement effects for heat transfer of internal sintered porous tube are obvious.