Here is the abstract you requested from the Thermal_2014 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Pumped two-phase cooling loops for high heat flux cooling|
|Keywords: Two-phase cooling, Minichannels, Microporous coatings|
|To improve two-phase cooling performance of minichannel heat sinks, different microporous coatings were applied including epoxy-based and sintered copper particles. The use of coatings reduced both parallel channel instabilities and the heat sink base temperature oscillations compared with uncoated minichannels. Moreover, no increase in pressure drop was observed using the microporous coatings (which are very thin compared to the hydraulic diameter of the channels). In addition, the heat transfer coefficient in coated minichannels was almost 1.5 times larger than that of uncoated minichannels. In small coated channels (larger than minichannels), the heat transfer coefficient and critical heat flux was found to be nearly 2.5 times and 1.5-2 times higher, respectively, than those for uncoated small channels. The two-phase cooling performance of sintered copper coated minichannels were also studied. The coatings had a uniform thickness of 35-70 µm, and the particle sizes were in three ranges: smaller than 20 µm, 63-74 µm, and 125-149 µm. The high conductivity of coating resulted in low additional thermal resistance. The heat transfer performance of the heat sink was quantified by computing the heat transfer coefficient and wall superheat as a function of applied heat flux, mass flux, and amount of subcooling at the heat sink inlet. Representative results showed higher heat transfer coefficients and lower wall superheats with coated heat sinks. Also, different refrigerants (R134a and R404a) were tested and results indicated that the heat transfer coefficient using R134a was up to 30% higher.|
Advanced Cooling Technologies, Inc.