湿工况下肋片效率计算方法分析、总结与改进

Analysis,summary and improvement of fin efficiency calculation method under wet condition

在除湿工况下,肋片效率受到冷却过程传热和除湿过程传质的共同影响。由于传热传质的复杂性,现有的多种湿工况下肋片效率计算方法的物理含义不同。然而肋片效率计算方法最终都体现为一个肋片效率计算公式,不同方法之间物理含义的区别往往被掩盖在这一表象的计算公式之下。介绍了采用不同建模方法时湿工况下求解肋片管式换热器肋片效率的过程,指出了不同肋片效率公式的关键区别,并就使用换热与压降关联式时应采用何种建模方法以及相应的肋片效率公式给出了建议;在前人研究的基础上,对几种肋片效率公式提出了简化方法。

The fin efficiency is influenced by the heat transfer in cooling process and the mass transfer in desiccant process under wet condition. Due to the complexity of heat and mass transfer, the fin efficiency calculation methods with different physical implications are independently developed. Since it is hard to identify the differences of physical implications among different fin efficiency calculating equations, those equations could be mistakenly applied. Presents the processes of solving fin efficiency of fin-and-tube heat exchangers using different modeling methods under wet condition, compares different fin efficiency calculating equations, and identifies the key difference for providing comments on how to choose an appropriate fin efficiency calculating equation. Provides simplified methods for several kinds of fin efficiency calculating equations to facilitate their applications.