Critical heat flux during subcooled flow boiling in narrow rectangular channels
- Univ. of California, Los Angeles, CA (United States). Mechanical and Aerospace Engineering Dept.
The heat generating capacity of energy equipment and electronic devices has increased tremendously with the progress of technology. Subcooled flow boiling, because of its extremely high heat transfer ability, has thus acquired great importance as a cooling technique. For instance, in nuclear fusion reactors some components such as diverters and beam dumps of neutron beam injectors are exposed directly to the plasma or high energy beam. The critical heat flux during subcooled flow boiling in narrow one-side heated rectangular channels was investigated experimentally using fluorinert liquid PF-5060 as a coolant. Three channel widths were examined, that is 1.3mm, 2.0mm, and 3.0mm. The heating surface was 10mm wide and 200mm long and only vertical upflow was experimented. Experiments were conducted at nearly atmospheric pressure under the following conditions: subcooled coolant mass velocity 2,000--5,000 kg/m{sup 2}s; inlet temperature 24--47 C; exit pressure 1.0--1.4 bar; equilibrium quality at channel exit {minus}0.58 to {minus}0.28. Critical heat flux under the above experimental conditions was found to increase with increase in mass velocity, with decrease in the channel width, and with increase in the inlet subcooling. Visual observations showed that bubbles were small and had diameter less than 100{micro}m. A comparison of the data with correlations reported in the literature showed that the correlations generally tended to overpredict the data. The correlations also do not show a proper trend with respect to the effect of channel width on critical heat flux. A new correlation based on dimensional analysis has been proposed. The correlation proposed can predict experimental data within 20% uncertainty.
- OSTI ID:
- 442598
- Report Number(s):
- CONF-961105-; ISBN 0-7918-1521-8; TRN: IM9712%%23
- Resource Relation:
- Conference: 1996 international mechanical engineering congress and exhibition, Atlanta, GA (United States), 17-22 Nov 1996; Other Information: PBD: 1996; Related Information: Is Part Of Proceedings of the ASME Heat Transfer Division. Volume 3: Experimental studies in multiphase flow; Multiphase flow in porous media; Experimental multiphase flows and numerical simulation of two-phase flows; Fundamental aspects of experimental methods; HTD-Volume 334; Cheung, F.B. [ed.] [Pennsylvania State Univ., University Park, PA (United States)]; Yang, B.W. [ed.] [Columbia Univ., New York, NY (United States)]; Riznic, J.R. [ed.] [Atomic Energy Control Board, Ottawa, Ontario (Canada)]; Seyed-Yagoobi, J.; Hassan, Y.A.; Kihm, K.D. [eds.] [Texas A and M Univ., College Station, TX (United States)]; Kim, J.H. [ed.] [Electric Power Research Inst., Palo Alto, CA (United States)]; Paolucci, S. [ed.] [Univ. of Notre Dame, IN (United States)]; Oosthuizen, P.H. [ed.] [Queen`s Univ., Kingston, Ontario (Canada)]; PB: 438 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Static-flow-instability in subcooled flow boiling in wide rectangular parallel channels
A New Facility for Measurements of Three-Dimensional, Local Subcooled Flow Boiling Heat Flux and Related Critical Heat Flux for PFCs