Critical heat flux of butanol aqueous solution

Shotaro Nishiguchi, Naoki Ono, Masahiro Shoji

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

Aqueous solutions of some alcohols such as butanol show peculiar temperature dependence of surface tension. Contrary to ordinary liquids or solutions, the surface tension increases with temperature at the range of high liquid temperature. So at the triple-phase point on a heated surface, the thermo-capillary force acts for the liquid to wet the heated surface, so the solutions are sometimes called as "self-wetting liquids". Self-wetting liquids may prohibit the dry-out of a heated surface so that the heat transfer performance would be enhanced. For this reason, applications of self-wetting liquids to heat transfer devices such as heat pipes are actively studied in recent years. However, the heat transfer characteristics of boiling of self-wetting liquids are not fully understood. In the present research, a boiling experiment of butanol aqueous solution was performed on a heated fine wire in order to make clear the fundamental heat transfer characteristics. A heated wire configuration is easy to observe the phenomena and easy to address the fundamental issues of boiling. In the present experiment, nucleate boiling heat transfer were investigated with special attention to critical heat flux (CHF), by changing solution concentration and temperature. Bubbling aspects were observed by high-speed video camera. It is found from the experiment that CHF is generally enhanced 20 to 50 % when compared to the case of pure water. It is also found that at a certain concentration and at a certain liquid temperature, peculiar boiling takes place where very small bubbles are emitted from the heated wire and CHF enhancement becomes very large from 2 to 3 times higher than CHF of pure water. The temperature when the peculiar boiling takes place is close to boiling temperature of the solution. These results suggest the possibility of application of aqueous solution to high-performance cooling devices utilizing micro-scaled channels because generating bubbles are small enough so that the pressure loss of the flow passage is small and heat transfer rate is very large.

Original languageEnglish
Title of host publicationProceedings of the 6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008
Pages723-728
Number of pages6
EditionPART A
DOIs
Publication statusPublished - 2008 Dec 1
Event6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008 - Darmstadt, Germany
Duration: 2008 Jun 232008 Jun 25

Publication series

NameProceedings of the 6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008
NumberPART A

Conference

Conference6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008
CountryGermany
CityDarmstadt
Period08/6/2308/6/25

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ASJC Scopus subject areas

  • Process Chemistry and Technology

Cite this

Nishiguchi, S., Ono, N., & Shoji, M. (2008). Critical heat flux of butanol aqueous solution. In Proceedings of the 6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008 (PART A ed., pp. 723-728). (Proceedings of the 6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008; No. PART A). https://doi.org/10.1115/ICNMM2008-62378