螺旋扭带强化管内的流动沸腾传热

以乙醇、正丙醇为工作介质，研究了垂直管道内插入扭带对流动沸腾传热的强化效果，采用扭带的扭率为２．５、５．０和７．５。通过实验探讨了热通量、蒸汽干度、质量流速和扭率对流动沸腾传热特性的影响，结果表明，插入扭带与空管相比，流动沸腾传系数明显提高，在ＪＣＣｈｅｎ双机理加和模型的基础节螺旋流的特点，预测的螺旋流沸腾传系数与实验值吻合良好。

AUGMENTATION OF FLOW BOILING HEAT TRANSFER IN TUBES WITH TWISTED TAPE INSERTS

This paper studies the augmentation of flow boiling heat transfer in a vertical tube with a twited tape insert. The working medium is ethanol and I propanol. The tape twist ratios are 2.5, 5.0 and 7.5. The influences of heat flux, vapor quality, mass velocity and tape twist ratio on the characteristics of swirl flow boiling heat transfer are discussed. Experimental results show that the heat transfer coefficient of swirl flow increases notably compared with axial flow. Beased on the chen two mechanisms superposition model, characteristics of the swirl flow are considered. The predicted swirl flow heat transfer coefficients agree with experimental data satisfactorily.