Inscrição na biblioteca: Guest
Portal Digital Begell Biblioteca digital da Begell eBooks Diários Referências e Anais Coleções de pesquisa
Heat Transfer Research
Fator do impacto: 0.404 FI de cinco anos: 0.8 SJR: 0.264 SNIP: 0.504 CiteScore™: 0.88

ISSN Imprimir: 1064-2285
ISSN On-line: 2162-6561

Volumes:
Volume 50, 2019 Volume 49, 2018 Volume 48, 2017 Volume 47, 2016 Volume 46, 2015 Volume 45, 2014 Volume 44, 2013 Volume 43, 2012 Volume 42, 2011 Volume 41, 2010 Volume 40, 2009 Volume 39, 2008 Volume 38, 2007 Volume 37, 2006 Volume 36, 2005 Volume 35, 2004 Volume 34, 2003 Volume 33, 2002 Volume 32, 2001 Volume 31, 2000 Volume 30, 1999 Volume 29, 1998 Volume 28, 1997

Heat Transfer Research

DOI: 10.1615/HeatTransRes.2018026607
Forthcoming Article

FLOW BOILING OF R134A IN A HIGH SURFACE AREA MICROCHANNEL ARRAY FOR HIGH-FLUX LASER DIODE COOLING

Taylor Bevis
Phillips
Bryan Burk
Colorado State University
Jensen Hoke
Colorado State University
Jack Kotovsky
Lawrence Livermore National Laboratory
Julie Hamilton
Lawrence Livermore National Laboratory
Todd Bandhauer
Colorado State University

RESUMO

Packaging high average power laser diode arrays that generate heat at an area average flux in excess of 1 kW cm-2 is a significant engineering challenge. While liquid microchannel coolers have demonstrated up to 11.9 kW cm-2, two-phase microchannel array coolers have not achieved 1 kW cm-2 due to critical heat flux and flow instabilities. In the current study, flow boiling heat transfer was characterized for a 1 × 10 mm heated zone centered over a 5 × 10 mm array of 125 very small channels (45 × 200 microns) with R134a as the phase change fluid. The high aspect ratio channels (4.4:1) were manufactured using MEMS fabrication techniques, which yielded a large heat transfer surface area to volume ratio. A test facility was used to characterize the heat transfer performance of boiling R134a over a range of saturation temperatures (15°C to 25°C), mass fluxes (735 - 2,230 kg m-2 s-1), and heat duties (<110.3 W). During the tests, the calculated outlet vapor quality exceeded 61% and the base heat flux at the heater reached a maximum of 1.1 kW cm-2. The resulting average experimental flow boiling heat transfer coefficients are found to be as large a 13.4 kW m-2 K-1 over the approximately 3 mm two-phase region, with an average uncertainty of ±2.72 %. A substantial amount of heat was spread downstream via the low thermal resistance silicon floor. Specifically, between 29.5 % and 55.1 % of the heat dissipated in the two-phase region was dissipated over the heater. The remaining heat dissipated in the two-phase region was dissipated in the 2 mm of channel downstream of the heater. This suggests that heat spreading from the hotspot played a vital role in dissipating the heat loa