The flow and heat transfer in two-phase double-tube thermosiphons (the effect of subcooling)
An experimental study was performed to investigate the effect of subcooling on the flow and heat transfer in two-phase double-tube thermosiphons with three types of inner tubes using water, ethanol, and Freon 113 as the working fluids. The same experiment for a single-tube thermosiphon was also carried out for comparison. As a result, a correlating expression for the heat-transfer coefficients in two-phase double- and single-tube thermosiphons is presented. The expression presented, by taking account of subcooling and the properties of working fluids, agreed well with the experimental data. The critical heat flux increased slightly with an increase in the degree of subcooling, and the rate of increase for double-tube thermosiphon was bigger than that for the single-tube one. The circulation mass velocity first increased and then decreased, as the heat flux increased. After that, it increased again at a certain heat flux. This behavior was observe for both saturated and subcooled boiling. However, this curve was shifted to the larger heat-flux direction as the degree of sub-cooling increased.
- OSTI ID:
- 6840603
- Journal Information:
- Heat Transfer - Japanese Research; (United States), Vol. 22:8; ISSN 0096-0802
- Country of Publication:
- United States
- Language:
- English
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