Abstract: Two-phase thermosyphon loop heat exchangers are widely used in different industrial fields.The heat transfer simulation is important for design of thermosyphon.However,due to the complexity of boiling heat transfer and two-phase flow,empirical heat transfer models based on experimental data limit the scope of application,with some difficulties in model choice.In this paper,a mathematical distributed parameter model of two-phase thermosyphon loop is established; the datasets consist of 424 two-phase thermosyphon loop experimental data for 4 working fluids from 5 papers.These datasets are used to evaluate 7 widely used transfer models for evaporation.The results show that Kandlikar's flow boiling model and Rahmatollah's model are the best in calculation accuracy; Cooper's pool boiling model gives relatively good agreement with experimental data,indicating that nucleate boiling is the dominant mechanism; flow boiling models of Gungor and Winterton,Liu and Winterton show similar calculation accuracy and the error is acceptable; but Imura's pool boiling model is not suitable for the thermosyphon heat transfer simulation.

Key words: thermosyphon loop, evaporator, heat transfer model

摘要： 两相热虹吸换热器在工业领域应用广泛,其制冷剂内侧的传热过程是热虹吸管设计的基础。然而由于沸腾传热和两相流动的复杂性,基于实验的经验传热模型各自差异很大且适用范围有限,给热虹吸管建模时传热模型选取带来了一定的困难。建立了稳态两相热虹吸循环分布式参数模型,利用5篇文献中4种工质共424个热虹吸管传热实验数据点,对热虹吸管中常用的7种传热模型进行比较评价,为模型选取提供参考。结果发现:Kandlikar流动沸腾模型和Rahmatollah拟合的热虹吸管传热模型模拟精度最好,推荐使用;Cooper池沸腾也有较好的精度,说明核态沸腾在热虹吸管传热中占主导地位; Gungor and Winterton、Liu and Winterton等常用的流动沸腾模型模拟精度差别不大,误差尚可接受;Imura池沸腾模型不适用于热虹吸管传热模拟。

关键词: 热虹吸, 蒸发器, 传热模型