不同微肋表面横管外降膜吸收过程中传热特性分析  

Analysis of heat transfer properties in falling-film absorption process of different micro fin surfaces out horizontal tubes

作　　者：王天[1] 谷雅秀[1] 赵润青 屈长杰 

机构地区：[1]长安大学环境科学与工程学院,陕西西安710054

出　　处：《西安理工大学学报》2016年第3期343-348,共6页Journal of Xi'an University of Technology

基　　金：国家自然科学基金资助项目(51106014)

摘　　要：在溴化锂吸收式制冷系统中,吸收器的换热性能在很大程度上影响着整个机组的制冷性能,故研究如何提高吸收器的性能很有必要。本文在理论分析光滑横管外降膜吸收传热特性的基础上,对管外缠绕不同丝径金属丝网的强化管进行理论分析与数值模拟。研究结果表明:随着周向角的增加,换热管表面液膜厚度先减小后增大,热边界层厚度逐渐增大,局部传热系数逐渐减小;光滑横管外包敷金属丝网后,吸收器的换热性能大大提高,但丝径过小或过大都会影响换热效果;当强化管丝径为0.2mm时,最有利于吸收器换热。In the Lithium Bromide（LiBr） absorption refrigeration system, the heat transfer performanceof the absorber largely influences the heat transfer performance of the entire refrigerationsystem, so it is necessary to explore how to improve the absorption effect of the absorber.Based on the analysis of heat transfer properties in falling-film absorption outside the smoothtubes, the theoretical analysis and numerical simulation are carried out about the heat transfer enhancedtubes wrapped with a stainless-steel wire-mesh screen to hold up more liquid film in thispaper. The research results show that with an increase of the radius angle, the liquid film thicknessdecreases first and then increases with the thermal boundary layer thickness increasing andthe local heat transfer coefficient decreasing. The measurement of wrapping the horizontal tubewith a wire-mesh screen can enhance the heat and mass transfer performance in absorber. But ifthe wire diameter is too big or too small, it will has a bad influence on the heat and mass transferperformance. When the wire diameter is equaling to 0. 2mm, the heat transfer performance andthe absorption effect are the best.

关 键 词：吸收式制冷 降膜吸收 强化管 数值模拟 

分 类 号：TB651.2[一般工业技术—制冷工程]