Investigation on Active Thermal Control Method with Pool Boiling Heat Transfer at Low Pressure
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In order to maintain a desirable temperature level of electronic equipment at low pressure, the thermal control performance with pool boiling heat transfer of water was examined based on experimental measurement. The total setup was designed and performed to accomplish the experiment with the pressure range from 4.5 kPa to 20 kPa and the heat flux between 6 kW/m2 and 20 kW/m2. The chosen material of the heat surface was aluminium alloy and the test cavity had the capability of varying the direction for the heat surface from vertical to horizontal directions. Through this study, the steady and transient temperature of the heat surface at different pressures and directions were obtained. Although the temperature non-uniformity of the heat surface from the centre to the edge could reach 10°C for the aluminium alloy due to the varying pressures, the whole temperature results successfully satisfied with the thermal control requirements for electronic equipment, and the temperature control effect of the vertically oriented direction was better than that of the horizontally oriented direction. Moreover, the behaviour of bubbles generating and detaching from the heat surface was recorded by a high-resolution camera, so as to understand the pool boiling heat transfer mechanism at low-load heat flux. These pictures showed that the bubbles departure diameter becomes larger, and departure frequency was slower at low pressure, in contrast to 1.0 atm.
KeywordsPool Boiling Heat Transfer Water Low Pressure Low-load Heat Flux Experiment Measurement
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- McGillis W.R., Fitch J.S., Hamburgen W.R., Carey V.P., Pool boiling heat enhancement techniques for water at low pressure, Western Research Laboratory (WRL) Research Report, December, 1990.Google Scholar
- Sloan A., Penley S., Wirtz R.A., Sub-atmospheric pressure pool boiling of water on a screen-laminate enhanced surface, 25th IEEE SEMI-THERM Symposium, New York, 2009, 246–253.Google Scholar
- Feldmann H. and Luke A., Nucleate boiling in water for different pressures, International Refrigeration and Air Conditioning Conference, West Lafayette, 2008, paper 982.Google Scholar
- Flores S., Development of a heat transfer test rig for finding heat transfer characteristics of liquid methane, MS. thesis, The University of Texas at El Paso, 2011.Google Scholar
- Speetjens M., Steady-state behaviour of a three-dimen—sional pool-boiling problem, Thermal Issues in Emerging Technologies, ThETA 1, Cairo, Egypt, 2007.Google Scholar
- Forrest E.C., Hu L.W., McKrell T.J., Buongiorno J., Ostrovsky Y., Pressure effects on the pool boiling of the fluorinated ketone C2F5C(O)CF(CF3)2, Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems, New York, 2010.Google Scholar