An Assessment of Momentum Models for Two-phase Thermosyphon Loop

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 impor...

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Bibliographic Details
Main Authors: Zhang Penglei, Shi Wenxing, Han Linjun, Wang Baolong, Li Xianting
Format: Article
Language:zho
Published: Journal of Refrigeration Magazines Agency Co., Ltd. 2013-01-01
Series:Zhileng xuebao
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Online Access:http://www.zhilengxuebao.com/thesisDetails#10.3969/j.issn.0253-4339.2013.02.001
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Summary: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.
ISSN:0253-4339