標題: | Saturated flow boiling heat transfer and associated bubble characteristics of FC-72 on a heated micro-pin-finned silicon chip |
作者: | Lie, Y. M. Ke, J. H. Chang, W. R. Cheng, T. C. Lin, T. F. 機械工程學系 Department of Mechanical Engineering |
公開日期: | 1-九月-2007 |
摘要: | An experiment is carried out here to investigate flow boiling heat transfer and associated bubble characteristics of FC-72 on a heated micro-pin-finned silicon chip flush-mounted in the bottom of a horizontal rectangular channel. Besides, three different micro-structures of the chip surface are examined, namely, the smooth, pin-finned 200 and pin-finned 100 surfaces. The pin-finned 200 and 100 surfaces, respectively, contain micro-pin-fins of size 200 mu m x 200 mu m x 70 mu m (width x length x height) and 100 mu m x 100 mu m x 70 mu m. The pitch of the fins is equal to the fin width for both surfaces. The effects of the FC-72 mass flux, imposed heat flux, and surface microstructures of the silicon chip on the FC-72 saturated flow boiling characteristics are examined in detail. The experimental data show that an increase in the FC-72 mass flux causes a delay in the boiling incipience. However, the flow boiling heat transfer coefficient is not affected by the coolant mass flux. But adding the micro-pin-fin structures to the chip surfaces can effectively enhance the single-phase convection and flow boiling heat transfer. Moreover, the mean bubble departure diameter and active nucleation site density are reduced for a rise in the FC-72 mass flux. A higher coolant mass flux results in a higher mean bubble departure frequency. Furthermore, larger bubble departure diameter, higher bubble departure frequency, and higher active nucleation site density are observed at a higher imposed heat flux. We also note that adding the micro-pin-fins to the chips decrease the bubble departure diameter and increase the bubble departure frequency. However, the departing bubbles are larger for the pin-finned 100 surface than the pin-finned 200 surface but the bubble departure frequency exhibits an opposite trend. Finally, empirical equations to correlate the present data for the FC-72 single-phase liquid convection and saturated flow boiling heat transfer coefficients and for the bubble characteristics are provided. (c) 2007 Elsevier Ltd. All rights reserved. |
URI: | http://dx.doi.org/10.1016/j.ijheatmasstransfer.2007.02.010 http://hdl.handle.net/11536/10363 |
ISSN: | 0017-9310 |
DOI: | 10.1016/j.ijheatmasstransfer.2007.02.010 |
期刊: | INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER |
Volume: | 50 |
Issue: | 19-20 |
起始頁: | 3862 |
結束頁: | 3876 |
顯示於類別: | 期刊論文 |