Characteristics on Spray Cooling Performance on the Micro-Porous Coated Surfaces

마이크로다공성 발열체 표면에서의 액체분무 냉각성능 특성

  • Kim Yoon-Ho (Graduate School of Mechanical Engineering, Korea University) ;
  • Choi Chi-Hwan (Graduate School of Mechanical Engineering, Korea University) ;
  • Lee Kyu-Jung (Department of Mechanical Engineering, Korea University)
  • 김윤호 (고려대학교 기계공학과 대학원) ;
  • 최치환 (고려대학교 기계공학과 대학원) ;
  • 이규정 (고려대학교 기계공학과)
  • Published : 2006.04.01

Abstract

Experiments on evaporative spray cooling on the square plate heaters with plain or micro-porous coated surfaces were performed in this study. Micro-porous coated surfaces were made by using DOM [Diamond particle, Omegabond 101, Methyl-Ethyl-Keton] method. In case of purely air-jet cooling, the micro-porous coating doesn't affect the cooling capacity. In spray cooling three different flow patterns (complete wetting, evaporative wetting, dryout) are observed on both plain and micro-porous coated surfaces. The effects of various operating conditions, such as water flow rate, particle size, and coating thickness were investigated on the micro-porous coated surfaces. It is found that the level of surface wetting is an important factor to determine the performance of spray cooling. It depends on the balance between absorbed liquid amount by capillary force over porosity and the evaporative amount. The micro-porous coated surface has largest cooling capacity, especially in the evaporative wetting zone. It is found that the effects of liquid flow rate and coating thickness are significant in evaporative wetting zone, but are not in complete wetting and dryout zones.

Keywords

References

  1. Choi, K.J. and Yao, S. C., 1987, Mechanisms of film boiling heat transfer of normally impacting sprays, International Journal of Heat and Mass Transfer, Vol. 30, pp. 311-318 https://doi.org/10.1016/0017-9310(87)90119-0
  2. Mudawar, I. and Valentine, W. S., 1989, Determination of the local Quench curve for spray-cooled metallic surfaces, Journal of Heat Treating, Vol. 7, No.2, pp.107-121 https://doi.org/10.1007/BF02833195
  3. Grissom, W. M. and Wierum, F. A., 1981, Liquid spray cooling of a heated surface, International Journal of Heat and Mass Transfer, Vol. 24, pp. 261-271 https://doi.org/10.1016/0017-9310(81)90034-X
  4. Fujimoto, H., Hatta, N., Asakawa, H. and Hashimoto, T., 1997, Predictable modeling of heat transfer coefficient between spraying water and a hot surface above the leidenfrost temperature, lSIJ International, Vol. 37, No.5, pp. 492-497
  5. Oliphant, K., Webb, B. W. and McQuay, M. Q., 1998, An experimental comparison of liquid jet array and spray impingement cooling in the non-boiling regime, Experimental Thermal and fluid science, Vol. 18, pp. 1-10 https://doi.org/10.1016/S0894-1777(98)10013-4
  6. O'Connor, J. P. and You, S. M., 1995, A painting technique to enhance pool boiling heat transfer FC-72, ASME Journal of Heat Transfer, Vol. 117, No.2, pp.387-393 https://doi.org/10.1115/1.2822534
  7. Kline, S. J. and McClintock, F. A., 1953, Describing uncertainties in single-sample experiments, Mech. Eng., Vol. 75, No.1, pp.3-12
  8. Bar-Cohen, A., 1997, Thermal management of microeletronics in the 21st century, IEEE/CPMT Electronic Packing Technology Conference
  9. Fujimoto, H., Hatta, N., Asakawa, H. and Hashimoto, T., 1997, Predictable modeling of heat transfer coefficient between spraying water and a hot surface above the leidenfrost temperature, lSIJ International, Vol. 37, No.5, pp. 492-497
  10. Kim, J. H., You, S. M. and Stephen, U. S. Choi, 2004, Evaporative spray cooling of plain and microporous coated surfaces, International Journal of Heat and Mass Transfer, Vol. 47, pp.3307-3315 https://doi.org/10.1016/j.ijheatmasstransfer.2004.01.018
  11. Webb, R. L., 1981, The evolution of enhanced surface geometries for nucleate boiling, Heat Transfer Engineering, Vol. 2, No. 3-4, pp. 46-69 https://doi.org/10.1080/01457638108962760
  12. Kurihari, H. M. and Myers, J. E., 1960, Effects of superheat and roughness on the boiling coefficients, AIChE J., Vol. 6, No.1, pp.83-91 https://doi.org/10.1002/aic.690060117
  13. Chang, J. Y. and You, S. M., 1997, Boiling heat transfer phenomena from micro-porous and porous surfaces in saturated FC-72, International Journal of Heat Mass Transfer, Vol. 40, No. 18, pp.4437-4447 https://doi.org/10.1016/S0017-9310(97)00055-0