| 摘要: |
| 两相热虹吸管在工业领域应用广泛，其内部工质的流动模拟是热虹吸管设计的主要因素。然而在模拟过程中，存在着两相流模型适用范围有限而自然循环模拟精度要求高的矛盾，因此有必要根据热虹吸特性对现有两相流动量模型进行适用性评价。建立了稳态两相热虹吸循环模型，结合不同工质（水、R113和R600a）的两相热虹吸循环实验数据，分别对4种均相流动量模型和24种分相流动量模型组合(4种分相流摩阻压降模型和6种截面含气率模型组合)进行了计算比较，发现Lorkhart-Martinelli摩阻压降模型结合Tom截面含气率模型的模拟精度最高。利用此模型分析两相热虹吸循环内工质的流动特征，证实了质量流速随着热流密度的增大先增大后减小的规律，并从内部分布参数变化角度给出了新的解释。 |
| 关键词: 热虹吸 两相流 模拟 评价 流动特性 |
| DOI： |
| 投稿时间：2012-06-09
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| 基金项目:国家自然科学基金（51176084)和国家杰出青年基金（51125030）资助项目 |
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| An Assessment of Momentum Models for Two-phase Thermosyphon Loop |
| Zhang Penglei,Shi Wenxing,Han Linjun,Wang Baolong,Li Xianting |
| (Department of Building Science, School of Architecture, Tsinghua University) |
| Abstract: |
| Two-phase thermosyphon heat exchangers are widely used in different industry fields. The fluid flow characteristic is very important for the design of thermosyphon. However, the existing two-phase models are not accurate enough for the simulation of two-phase thermosyphon loop .Therefore it is important to make an assessment of existing two-phase momentum models corresponding to thermosyphon loop features. The mathematical model of two-phase thermosyphon loop, which include 4 homogenous pressure drop models, 24 separated-phase momentum combination models (4 separated-phase frictional pressure drop models multiply 6 representative void fraction correlations), has been developed in the paper. The predicted results from different models are compared with the experimental results of two-phase thermosyphon with refrigerants H2O, R113 and R600a. The comparison results show that the combination of Lorkhart-Martinelli frictional pressure drop model and Tom void fraction model is better than other models. Finally, the flow features of two-phase thermosyphon loop have been simulated. It is shown that for a specific loop, the mass flux increases and then decreases slowly with the increase of heat flux. A reasonable explanation is given to the phenomenon. |
| Key words: thermosyphon loop two-phase flow simulation assessment flow features |
