A Study on High Heat Flux Cooling for Electronic Devices using Subcooled Flow Boiling : Microbubble emission boiling of binary mixture

Abstract

Critica1 heat fluxes are obtained in subcooled pool boiling of mix加 res with alcohol and water by burning out stain 置 ess st I plate heater ． lhe critical heat fluxes change with mass concentration of alcohol ． For 【 he mixtures of poLyhydric alcohols ，1 − butanol and 2 ・ propanol ， the maximum criIical heat fluxes are about 200 percent higher than that of water ． In subcoolOd flow boiling of elhanol −water and 1・ butanQl − water mixtures in a horizontal r 【 angular channel ， microbubble emission bo埀 1ing occurs in transition boijing and the heat fiuxes a 【e abouI 50 percent higher thIm water at same superheat of heating surface ． The maximum heaI伽 xes of the mixtures reach 8 MWm2 at 40K of liquid subcooling and O． 5mls ofliquid velocily ． Key Words ：Bina ワ miXture ・ CHE F ' OW う 0 "' η ＆ ∫ 謬 わ COO "π 8， 搨「 icroう μ 勧 ' θ 8配 ' ∬ ' 0 π わ0 ' "π 8

Enhancement of heat transfer in subcooled flow boiling with microbubble emission

“…4 [4]. Then, MEB is strongly dependent on the liquid subcooling and the liquid velocity as shown in Table 1 [5]. Table 1 shows MEB generations.…”

“…As indicated in Table 1, MEB is easy to occur for the higher liquid velocity and higher liquid subcooling and is strongly affected by a liquid subcooling and a liquid velocity in the flow channel [4,5]. For the smaller channels at lower liquid subcooling and liquid velocity, MEB was not held stably and easily to turn to film boiling.…”

“…3 for an example [5]. The heating surface is 10 mm · 10 mm of surface area and is placed at the bottom surface of the rectangular channels.…”

Condensation and Collapse of Vapor Bubbles Injected in Subcooled Pool

“…This unique phenomenon was reported by Inada et al (1986), and a large number of researches have followed to grasp an occurring condition and heat transfer characteristics of this phenomenon in the boiling on the flat surface (Suzuki et al 2002(Suzuki et al , 2009), on the thin wire (Tange et al 2004), and in the microchannel (Wang and Cheng 2009). These fabulous researches have indicated that this boiling process emerges under a rather high subcooled condition with a higher heat flux than the CHF accompanying with continuous formation and emission of a number of micrometer-scale bubbles from the heated surface (Suzuki and Inagaki 2005). A series of experimental work were recently carried out by a group of The University of Tokyo (Tange et al 2004) to indicate growing and collapsing process of the vapor bubble on a thin wire.…”

Application of Boiling Heat Transfer to High-Heat-Flux Cooling Technology in Power Electronics

“…[9,10] For example, the maximum heat flux is higher than 1000 W/cm 2 in subcooled flow boiling of water with heating surfaces smaller than 10 mm × 10 mm. [8,11] According to the investigations of MEB, the authors proposed two models for cooling devices in power electronics.…”