Enhanced Flow Boiling Over Open Microchannels With Uniform and Tapered Gap Manifolds

Flow boiling in microchannels has been extensively studied in the past decade. Instabilities, low critical heat flux (CHF) values, and low heat transfer coefficients have been identified as the major shortcomings preventing its implementation in practical high heat flux removal systems. A novel open microchannel design with uniform and tapered manifolds (OMM) is presented to provide stable and highly enhanced heat transfer performance. The effects of the gap height and flow rate on the heat transfer performance have been experimentally studied with water. The critical heat fluxes (CHFs) and heat transfer coefficients obtained with the OMM are significantly higher than the values reported by previous researchers for flow boiling with water in microchannels. A record heat flux of 506W/cm 2 with a wall superheat of 26.2 � C was obtained for a gap size of 0.127mm. The CHF was not reached due to heater power limitation in the current design. A maximum effective heat transfer coefficient of 290,000W/m 2 � C was obtained at an intermediate heat flux of 319W/cm 2 with a gap of 0.254mm at 225mL/min. The flow boiling heat transfer was found to be insensitive to flow rates between 40‐333mL/min and gap sizes between 0.127‐1.016mm, indicating the dominance of nucleate boiling. The OMM geometry is promising to provide exceptional performance that is particularly attractive in meeting the challenges of high heat flux removal in electronics cooling applications. [DOI: 10.1115/1.4023574]

[1]  A. Majumdar,et al.  Nanowires for enhanced boiling heat transfer. , 2009, Nano letters.

[2]  I. Mudawar,et al.  Flow Boiling in a Micro-Channel Coated With Carbon Nanotubes , 2009, IEEE Transactions on Components and Packaging Technologies.

[3]  Albert Mosyak,et al.  A uniform temperature heat sink for cooling of electronic devices , 2002 .

[4]  S. Kandlikar,et al.  The effect of inlet constriction on bubble growth during flow boiling in microchannels , 2009 .

[5]  Satish G. Kandlikar,et al.  Evaluation of Jet Impingement, Spray and Microchannel Chip Cooling Options for High Heat Flux Removal , 2007 .

[6]  Yoav Peles,et al.  Local measurement of flow boiling in structured surface microchannels , 2007 .

[7]  Yoav Peles,et al.  Flow boiling of water in a circular staggered micro-pin fin heat sink , 2008 .

[8]  Abhijit Mukherjee,et al.  Numerical study of single bubbles with dynamic contact angle during nucleate pool boiling , 2007 .

[9]  Y. Peles,et al.  Flow Boiling Instabilities in Microchannels and Means for Mitigation by Reentrant Cavities , 2008 .

[10]  Satish G. Kandlikar,et al.  Fundamental issues related to flow boiling in minichannels and microchannels , 2002 .

[11]  Chen Li,et al.  Parametric Study of Pool Boiling on Horizontal Highly Conductive Microporous Coated Surfaces , 2007 .

[12]  J. Khan,et al.  Enhanced flow boiling in a microchannel with integration of nanowires , 2012 .

[13]  S. Kandlikar,et al.  An Experimental Investigation of Flow Boiling Characteristics of Water in Parallel Microchannels , 2004 .

[14]  S. Garimella,et al.  Flow boiling heat transfer in microchannels , 2007 .

[15]  Ali Koşar,et al.  Reduced Pressure Boiling Heat Transfer in Rectangular Microchannels With Interconnected Reentrant Cavities , 2005 .

[16]  S. Kandlikar,et al.  Effects of nanowire height on pool boiling performance of water on silicon chips , 2011 .

[17]  S. Kandlikar,et al.  Pool Boiling Heat Transfer and Bubble Dynamics Over Plain and Enhanced Microchannels , 2011 .

[18]  C. Pan,et al.  A highly stable microchannel heat sink for convective boiling , 2009 .

[19]  S. Kandlikar,et al.  Effect of open microchannel geometry on pool boiling enhancement , 2012 .

[20]  S. Garimella,et al.  Flow Boiling Heat Transfer in , 2007 .

[21]  Albert Mosyak,et al.  Explosive boiling of water in parallel micro-channels , 2005 .

[22]  I. Mudawar,et al.  Flow boiling heat transfer in two-phase micro-channel heat sinks--II. Annular two-phase flow model , 2003 .

[23]  S. Kandlikar,et al.  Direct growth of copper nanowires on a substrate for boiling applications , 2011 .

[24]  R. Pease,et al.  High-performance heat sinking for VLSI , 1981, IEEE Electron Device Letters.

[25]  S. Kandlikar.  Controlling bubble motion over heated surface through evaporation momentum force to enhance pool boiling heat transfer , 2013 .

[26]  John T. Wen,et al.  Ledinegg instability in microchannels , 2009 .

[27]  Satish G. Kandlikar,et al.  Stabilization of Flow Boiling in Microchannels Using Pressure Drop Elements and Fabricated Nucleation Sites , 2006 .

[28]  A. Agrawal,et al.  An active control strategy for reduction of pressure instabilities during flow boiling in a microchannel , 2011 .

[29]  Yongping Yang,et al.  Pool boiling heat transfer on copper foam covers with water as working fluid , 2010 .

[30]  Roger R. Schmidt,et al.  High performance and subambient silicon microchannel cooling , 2007 .

[31]  I. Mudawar,et al.  Measurement and prediction of pressure drop in two-phase micro-channel heat sinks , 2003 .

[32]  Huiying Wu,et al.  Boiling instability in parallel silicon microchannels at different heat flux , 2004 .

[33]  S. Mori,et al.  Enhancement of the critical heat flux in saturated pool boiling using honeycomb porous media , 2009 .