Abstract
A new heat-transfer enhancement technique for originally dried up heat-transfer surface region is suggested by using a bubble pumping effect which is caused by nucleate boiling taking place in a narrow space with the configuration of a concentric double tube evaporator. The fundamental boiling heat-transfer measurement is conducted by boiling pure water at atmospheric pressure using a visualization facility consisting of a plain brass heat-transfer surface and a glass plate. To understand the mechanism of enhancement and to identify the optimum space width and geometry, the experiment is focused on the effect of boiling pattern and void fraction distribution on the heat-transfer coefficient. It has been revealed that the boiling heat-transfer coefficient is significantly enhanced in a narrow space, and particularly, the heat-transfer coefficient increases with increasing void fraction and at approximately between 80 and 90% void fraction the heat-transfer coefficient reaches a maximum. Finally, based on the fundamental study described above, author report on a progress of a high performance evaporator for a personal air conditioning system using new alternative refrigerant HCFC123 to recover the low temperature level waste heat from work station.
Original language | English |
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Title of host publication | Proc Eng Found Conf Pool External Flow Boiling |
Place of Publication | New York, NY, United States |
Publisher | Publ by ASME |
Pages | 381-386 |
Number of pages | 6 |
ISBN (Print) | 0791806677 |
Publication status | Published - 1992 |
Event | Proceedings of the Engineering Foundation Conference on Pool and External Flow Boiling - Santa Barbara, CA, USA Duration: 1992 Mar 22 → 1992 Mar 27 |
Other
Other | Proceedings of the Engineering Foundation Conference on Pool and External Flow Boiling |
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City | Santa Barbara, CA, USA |
Period | 92/3/22 → 92/3/27 |
ASJC Scopus subject areas
- Engineering(all)