干燥用振荡流热管强化传热研究

Study on Heat Transfer Enhancement of Oscillating-Flow Heat Pipe for Drying

振荡流热管(OFHP)在干燥领域有广阔的应用前景。提出了两种强化振荡流热管传热过程的方法:①用脉冲加热代替传统的连续加热;②采用非均匀热管流通截面。实验结果表明,这两种方法都能增强热管内的振荡过程,并使传热性能显著改善。脉冲加热的振荡流热管比相同功率下连续加热时的传热热流量提高15%～38%,当量热导率提高12%～63%。当加热功率大于100W时,非均匀截面振荡流热管比均匀截面振荡流热管的热流量和当量热导率也有明显提高。

Oscillating-flow heat pipe （OFHP） in drying has a great potential for application. In this article, two methods are proposed to enhance the heat transfer of OFHP：（1） pulse heating is adopted instead of conventional continuous heating; and （2） a tube with a non-uniform cross section is introduced. Experiments on the effects of these two methods have been studied in comparison with ordinary OFHP. Experimental results indicate that using the pulse heating and the non-uniform cross section channel can improve the oscillating process and the heat transport performance in the OFHP. The heat transfer rate of pulse heating OFHP is higher than that of the continuous by 15% - 38%, and the effective thermal conductivity is higher by 12% - 63% at the same heating power. The effective thermal conductivity and the heat transfer rate of the non-uniform cross section heat pipe are also higher than that of the uniform cross section heat pipe when the heating power is more than 100 W.