弦月形通道内热虹吸沸腾强化传热的数值计算  

Numerical Calculation of Thermosyphon Boiling Heat Transfer in Lunate Channel

作　　者：张联英[1] 吴裕远[1] 张璟[1] 陈东升[1] 郭金刚[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2003年第3期225-228,共4页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目 (5 0 1760 36)

摘　　要：弦月形狭缝通道热虹吸沸腾传热具有明显的传热强化效果 ,以溴化锂水溶液为工质的实验测试表明 ,其传热系数达到5～ 6kW/ (m2 ·K) .基于这种狭缝通道气泡底部薄液膜蒸发机理 ,建立了狭缝沸腾传热组合机理模型 .计算结果表明 ,随着时间的延续 ,膜内温度逐渐趋于线性分布 ;热流密度增大 ,液膜厚度变薄 ;沸腾传热系数随着热流密度的增大而增大 .分析了不同边界及初始条件下的气泡底部液膜蒸发传热特性 ,解释了气泡受挤压变形后气泡底部的液膜厚度减薄是传热效率得到增强的主要原因 .该传热模型的求解结果与实验结果吻合良好 。Thermosyphon boiling heat transfer in lunate channel can enhance heat transfer evidently. The experimental study proves that boiling heat transfer coefficient of LiBr water solution approaches to 5-6 kW/(m2&middotK). On the base of thin film evaporation mechanism of the channel, a comprehensive heat transfer model for thermosyphon boiling in narrow channel is developed. It is shown that the temperature distribution gradually becomes linear with time. The thickness of liquid film decreases with increasing heat flux, and boiling heat transfer coefficient increases with increasing heat flux. The evaporating heat transfer performance of the thin liquid film beneath bubbles is analyzed under different boundary conditions and initial conditions, and it is explained that the heat transfer coefficient is greatly enhanced due to the decreased thickness of thin film beneath flattened bubbles. This model is demonstrated to be reasonable by the fact that the results predicted by this model are coincided well with experimental ones.

关 键 词：强化传热 数值计算 弦月形通道 沸腾传热 热虹吸 传热系数 传热机理 

分 类 号：TK124[动力工程及工程热物理—工程热物理]