水蒸汽在水平三维微肋管内的凝结换热及阻力特性

CONDENSATION FOR STEAM IN THE HORIZONTAL TUBES WITH THREE DIMENSIONAL INNER MICROFINS

本文以水蒸汽为工质对水平三维微肋管内凝结换热及阻力特性进行了实验研究．与光管和二维管相比，在相同条件下，实验中效果最好的T3管全长平均凝结换热系数分别提高了113％～410％和20％～65％，同时，与二维管相比流动阻力增加较小，最大值不超过6．3％．比较另两种管型（T1，T2管）也证明三维管以较小的流阻增加为代价换取了明显的强化效果．

The experimental investigation was conducted on condensation heat transfer and flow drag characteristics of steam in the tubes with three-dimensional inner micro-fins. Under the same test condition, the average heat transfer coefficients of tube T3 with the highest heat transfer performance can be 113~410% and 20~65% higher than that of the smooth tube and tube with the 2-D inner micro-fin tube. The experimental results of tubes T1and T2 prove the obvious heat transfer enhancement can be obtained with the 3-D inner micro-fin tubes as the little increase of flow drag, also.