重力热管蒸发段气液分布形式与换热能力分析

Analysis on distribution of liquid and vapor phase and heat transfer capacity in evaporator of a two-phase closed thermosyphon

重力热管传热性能主要取决于蒸发段内液膜与液池的分布形式和换热过程。提出了许多液膜和液池换热机理与其影响因素之间的经验关联式。利用其中较完善的理论结果,总结了两者的换热机理分布图,通过计算传热系数的比值,发现在满足管内气液循环条件下,增加蒸发段内液膜段长度可以提高热管传热性能。

The heat transfer performance of the two-phase closed thermosyphon （ TPCT） is greatly affected by the distribution of liquid film and liquid pool,as well as the heat transfer process. The correlations which were applicable in a wider range with higher accuracy in the available studies were utilized to obtain the map of heat transfer mechanism of liquid film and liquid pool. By analyzing the ratio of their heat transfer coefficients,it was found out that the TPCT had better heat transfer performance with longer length of liquid film in evaporator,when the requirement of the continuous circulation of two-phase flow was achieved.