Abstract
Spay cooling is a complicated flow and heat transfer process affected by multi-factors among which the environmental pressure is extremely important. However the influence of pressure is not investigated sufficiently, especially the reduced pressure. In the present study, spray cooling under low initial environmental partial pressures and vapor partial pressures with R21 are investigated with a closed spray and condensation system. To study the influence of initial environmental partial pressure, different amounts of nitrogen are inflated into the vacuum flash chamber, while the vapor partial pressure is kept constant. To study the influence of vapor partial pressure, a cascade refrigerator is used to condense the vapor with different condensation temperatures so that the vapor partial pressure can be maintained or adjusted, while the initial environmental partial pressure is kept constant. The experimental results show that the spray cooling power increases monotonically with the increasing spray flow rate in the experimental range, while the cooling efficiency decreases with the increasing spray flow rate. The spray cooling power and cooling efficiency vary with the initial environmental partial pressure or the vapor partial pressure non-monotonously, which indicates there is an optimal pressure for the heat transfer performance. Besides, the mechanism of the non-monotonous variation trend is discussed based on the key aspects including flash evaporation, convection and boiling. Especially, the boiling heat transfer curve is applied to explain the trend.
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Kang B S, Choi K J. Cooling of a heated surface with an impinging water spray. KSME Int J, 1998, 12: 734–740
Zhou Z, Chen B, Wang R, et al. Coupling effect of hypobaric pressure and spray distance on heat transfer dynamics of R134a pulsed flashing spray cooling. Exp Thermal Fluid Sci, 2016, 70: 96–104
Wang Y, Liu M, Liu D, et al. Experimental study on the effects of spray inclination on water spray cooling performance in non-boiling regime. Exp Thermal Fluid Sci, 2010, 34: 933–942
Xie N N, Hu X G, Tang D W. Experimental investigation on spray cooling in rectangular capillary micro-grooves. J Eng Therm, 2010, 31: 805–809
Silk E A, Kim J, Kiger K. Spray cooling of enhanced surfaces: Impact of structured surface geometry and spray axis inclination. Int J Heat Mass Transfer, 2006, 49: 4910–4920
Silk E A, Kim J, Kiger K. Impact of cubic pin finned surface structure geometry upon spray cooling heat transfer. In: Proceedings of the Asme International Electronic Packaging And Technical Conference. San Francisco, 2005
Zhang Z, Jiang P X, Ouyang X L, et al. Experimental investigation of spray cooling on smooth and micro-structured surfaces. Int J Heat Mass Transfer, 2014, 76: 366–375
Rybicki J R, Mudawar I. Single-phase and two-phase cooling characteristics of upward-facing and downward-facing sprays. Int J Heat Mass Transfer, 2006, 49: 5–16
Chen R H, Chow L C, Navedo J E. Effects of spray characteristics on critical heat flux in subcooled water spray cooling. Int J Heat Mass Transfer, 2002, 45: 4033–4043
Chen R H, Chow L C, Navedo J E. Optimal spray characteristics in water spray cooling. Int J Heat Mass Transfer, 2004, 47: 5095–5099
Sehmbey M S, Chow L C, Hahn O J, et al. Effect of spray characteristics on spray cooling with liquid nitrogen. J Thermophysics Heat Transfer, 1995, 9: 757–765
Cader T, Westra L J, Eden R C. Spray cooling thermal management for increased device reliability. IEEE Trans Device Mater Relib, 2004, 4: 605–613
Bostanci H, Van Ee D, Saarloos B A, et al. Spray cooling of power electronics using high temperature coolant and enhanced surface. In: Proceedings of the Vehicle Power and Propulsion Conference. Dearborn, 2009
Kim J. Spray cooling heat transfer: The state of the art. Int J Heat Fluid Flow, 2007, 28: 753–767
Han F Y. Study on Heat Transfer Performance, Enhancement, and Surface Temperature Non-Uniformity in Spray Cooling. Dissertation for Dcotoral Degree. Heifei: University of Science and Technology of China, 2011
Jiang S, Dhir V K. Spray cooling in a closed system with different fractions of non-condensibles in the environment. Int J Heat Mass Transfer, 2004, 47: 5391–5406
Lin L, Ponnappan R. Heat transfer characteristics of spray cooling in a closed loop. Int J Heat Mass Transfer, 2003, 46: 3737–3746
Horacek B, Kiger K T, Kim J. Single nozzle spray cooling heat transfer mechanisms. Int J Heat Mass Transfer, 2005, 48: 1425–1438
Mudawar I, Bharathan D, Kelly K, et al. Two-phase spray cooling of hybrid vehicle electronics. IEEE Trans Comp Packag Technol, 2009, 32: 501–512
Timothy A B, Jordan L M, Asuncion C, Shuttle orbiter active thermal control subsystem design and flight experience. SAE Technical Paper, 1991
Golliher E, Romanin J, Kacher H,et al. Development of the compact flash evaporator system for exploration. SAE Technical Paper, 2007
Estes K A, Mudawar I. Correlation of sauter mean diameter and critical heat flux for spray cooling of small surfaces. Int J Heat Mass Transfer, 1995, 38: 2985–2996
Saury D, Harmand S, Siroux M. Experimental study of flash evaporation of a water film. Int J Heat Mass Transfer, 2002, 45: 3447–3457
Incropera F P, DeWitt D P, Bergman T L, et al. Fundamentals of Heat and Mass Transfer. New York: John Wiley & Sons, 2006
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Peng, C., Xu, X., Li, Y. et al. Experimental study on spray cooling under reduced pressures. Sci. China Technol. Sci. 62, 349–355 (2019). https://doi.org/10.1007/s11431-018-9370-y
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DOI: https://doi.org/10.1007/s11431-018-9370-y