水平横槽纹管内氨沸腾换热及压降特性实验研究

对水平横槽纹管内氨沸腾换热及其压降特性进行了实验研究，获得了不同热流密度、不同质量流速和不同局部蒸汽干度下沸腾换热和压降的实验数据。实验结果表明，在本实验的参数范围内，与光滑管相比，横槽纹管在压降增加不大的情况下可使管内沸腾换热系数提高３０％～１５０％，横槽纹管的节距减小对传热强化的作用明显，而对槽深的影响不大。还给出了横槽纹管内氨局部沸腾换热和压降的无因次准则关系式。

Experimental Study of Boiling Heat Transfer and Pressure Drop in Horizontal Annular Grooved Tube with Ammonia

The performance of boiling heat transfer and pressure drop in horizontal annulargrooved tube with ammonia has been studied.The experimental data of boiling heat transfer and pressure drop have been obtained in different specific rate of heat flow,mass flow and local quality of two phase mixture.The experimental results show that the boiling heat transfer coefficient in horizontal annular grooved tube can raise 30%～50% under slight increase of pressure drop by comparing with that of smooth tube.The decrease to the pitch of horizontal annular grooved tube is obviously influenced on enhancement of boiling heat transfer but not obviously on the depth of annular groove.Based on the experimental data,the modified formulas for calculating local boiling heat transfer coefficient and pressure drop in horizontal annular grooved tube with ammonia have been obtained.