细圆管内流动凝结换热的实验研究

EXPERIMENTAL STUDY ON FLOW CONDENSATION HEAT TRANSFER INSIDE SMALL/MINI-DIAMETER TUBE

通过实验，分析细圆管的倾斜角度和管径对管内蒸气流动凝结换热的影响。利用实测的管壁温度变化。估计凝结液沿周向的分布。探讨不同倾角和管径条件下；重力作用影响凝结换热的机制。研究表明，在小尺度下，重力的影响受蒸气剪切力和表面张力作用而削弱，现有通行的关联式不适用于细圆管内的凝结换热。

This paper analyzed experimentally the effects of tube inclination and diameter on flow condensation heat transfer characteristics for vapor flowing inside small/minidiameter tubes. A method was proposed to estimate the condensate film distribution inside tube by the measured tube wall temperatures along periphery. The mechanism of which gravity influenced condensation heat transfer in different diameter tubes and different tube inclinations are discussed in detail. The effect of gravity was found to be reduced by shear stress and surface tension, and then, the conventional correlations could not predict condensation heat transfer characteristics for small/mini-diameter tube properly.