A Microstructure Device for Single Phase Surface Cooling

2011 ◽  
Author(s):  
Juergen J. Brandner ◽  
Natrah binti Kamaruzaman ◽  
Stefan Maikowske
Keyword(s):  
Heat Flux ◽  
Pressure Drop ◽  
Single Phase ◽  
High Heat ◽  
Theoretical Background ◽  
Test Facility ◽  
Fluid Distribution ◽  
High Heat Flux ◽  
Surface Cooling ◽  
Micro Channels

A microstructure device for cooling of hot surfaces at liquid single phase laminar flow is presented. The initial design as well as the theoretical background is described in detail. It consists of numerous short micro channels acting as overflow structures and providing a relatively large hydraulic diameter, used in parallel between large inlet and outlet channels. The design was chosen to be scalable as well as appropriate for mass production in different materials. The fluid distribution was optimized as well as the dimensions of the overflow structures in terms of heat transfer, both by CFD simulations. Several devices were tested. They provide very high heat flux at reasonably low pressure drop. The temperature difference to achieve, heat flux and pressure drop can be adjusted easily by control of the applied mass flow. The design was tested as liquid-liquid heat exchanger in a simple lab-scale test facility. Moreover, using a copper electrically powered surface heat focus, some devices were tested as surface coolers.

Recent results of high heat flux testing at the Plasma Materials Test Facility

1996 ◽  
Author(s):  
Dennis L. Youchison ◽  
Robert D. Watson ◽  
Theron D. Marshall ◽  
Jimmie M. McDonald
Keyword(s):  
Heat Flux ◽  
High Heat ◽  
Test Facility ◽  
High Heat Flux

Numerical Study of Turbulent Heat Transfer and Pressure Drop Characteristics in a Water-Cooled Minichannel Heat Sink

2006 ◽  
Vol 129 (3) ◽  
pp. 247-255 ◽  
Author(s):  
X. L. Xie ◽  
W. Q. Tao ◽  
Y. L. He
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Pressure Drop ◽  
Wall Thickness ◽  
Heat Sink ◽  
Channel Wall ◽  
High Heat ◽  
Coolant Fluid ◽  
High Heat Flux ◽  
It Industry

With the rapid development of the Information Technology (IT) industry, the heat flux in integrated circuit (IC) chips cooled by air has almost reached its limit at about 100W∕cm2. Some applications in high technology industries require heat fluxes well beyond such a limitation. Therefore, the search for a more efficient cooling technology becomes one of the bottleneck problems of the further development of the IT industry. The microchannel flow geometry offers a large surface area of heat transfer and a high convective heat transfer coefficient. However, it has been hard to implement because of its very high pressure head required to pump the coolant fluid through the channels. A normal channel size could not give high heat flux, although the pressure drop is very small. A minichannel can be used in a heat sink with quite a high heat flux and a mild pressure loss. A minichannel heat sink with bottom size of 20mm×20mm is analyzed numerically for the single-phase turbulent flow of water as a coolant through small hydraulic diameters. A constant heat flux boundary condition is assumed. The effect of channel dimensions, channel wall thickness, bottom thickness, and inlet velocity on the pressure drop, temperature difference, and maximum allowable heat flux are presented. The results indicate that a narrow and deep channel with thin bottom thickness and relatively thin channel wall thickness results in improved heat transfer performance with a relatively high but acceptable pressure drop. A nearly optimized structure of heat sink is found that can cool a chip with heat flux of 350W∕cm2 at a pumping power of 0.314W.

Laminar Flow Forced Convection Heat Transfer Behavior of Phase Change Material Fluid in Microchannels With Staggered Pins

2010 ◽  
Author(s):  
Satyanarayana Kondle ◽  
Jorge L. Alvarado ◽  
Charles Marsh ◽  
Gurunarayana Ravi
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Phase Change ◽  
Single Phase ◽  
Convection Heat Transfer ◽  
Heat Removal ◽  
High Heat ◽  
High Heat Flux ◽  
Small Areas ◽  
Phase Fluid

Microchannels have been extensively studied for electronic cooling applications ever since they were found to be effective in removing high heat flux from small areas. Many configurations of microchannels have been studied and compared for their effectiveness in heat removal. However, there is little data available in the literature on the use of pins in microchannels. Staggered pins in microchannels have higher heat removal characteristics because of the continuous breaking and formation of the boundary layer, but they also exhibit higher pressure drop because pins act as flow obstructions. This paper presents numerical results of two characteristic staggered pins (square and circular) in microchannels. The heat transfer performance of a single phase fluid in microchannels with staggered pins, and the corresponding pressure drop characteristics are also presented. An effective specific heat capacity model was used to account for the phase change process of PCM fluid. Comparison of heat transfer characteristics of single phase fluid and PCM fluid are made for two pins geometries for three different Reynolds numbers. Circular pins were found to be more effective in terms of heat transfer by exhibiting higher Nusselt number. Circular pin microchannels were also found to have lower pressure drop compared to the square pin microchannels.

Commissioning phase of high heat flux test facility HELCZA

2017 ◽  
Vol 124 ◽  
pp. 344-347 ◽  
Author(s):  
R. Jílek ◽  
J. Prokůpek ◽  
P. Gavila ◽  
K. Samec ◽  
S. Neufuss
Keyword(s):  
Heat Flux ◽  
High Heat ◽  
Test Facility ◽  
High Heat Flux

Development of a High Heat Flux Test Facility for Plasma Facing Components

2009 ◽  
Vol 56 (1) ◽  
pp. 91-95 ◽  
Author(s):  
Young-Dug Bae ◽  
Suk-Kwon Kim ◽  
Dong-Won Lee ◽  
Bong-Guen Hong
Keyword(s):  
Heat Flux ◽  
High Heat ◽  
Test Facility ◽  
High Heat Flux ◽  
Plasma Facing Components

High Heat Flux Ion Beam Test Facility for Material Research and Development

1991 ◽  
Vol 19 (4) ◽  
pp. 2101-2111 ◽  
Author(s):  
Martin Lochter ◽  
Reinhard Uhlemann ◽  
Jochen Linke
Keyword(s):  
Heat Flux ◽  
Research And Development ◽  
Ion Beam ◽  
High Heat ◽  
Test Facility ◽  
Material Research ◽  
High Heat Flux ◽  
Beam Test

Micro Heat Changers and Surface-Micro-Coolers for High Heat Flux

2008 ◽  
Author(s):  
Ulrich Schygulla ◽  
Ju¨rgen J. Brandner ◽  
Eugen Anurjew ◽  
Edgar Hansjosten ◽  
Klaus Schubert
Keyword(s):  
Heat Flux ◽  
Heat Exchanger ◽  
Mass Flow ◽  
Pressure Loss ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Micro Heat Exchanger ◽  
Micro Channels ◽  
Higher Temperature

This publication describes the development of a new microstructure to transfer high heat fluxes. With a simple mathematical model based on heat conduction theory for the heat transfer in a micro channel at laminar flow conditions it was deduced that for the transmission of high heat fluxes only the initial part at the beginning of the micro channels is of importance, i.e. the micro channels should be short. Based on this principle a micro structure was designed with a large number of short micro channels taken in parallel. With this newly developed microstructure a prototype of a micro heat exchanger and a surface micro cooler was manufactured and tested. Using the prototype of the micro heat exchanger, manufactured of plastic, heat fluxes up to 500 W/cm2 were achieved at a pressure loss of 0.16 MPa and a mass flow of the water of 200 kg/h per passage. Due to the use of materials with a higher temperature resistance and higher stability like aluminum or ceramic, higher water throughputs and higher flow velocities could be realized in the micro channels. Thus it was possible to increase the heat flux up to approx. 800 W/cm2 at a pressure loss of approx. 0.35 MPa and a mass flow of 350 kg/h per passage. The important focus of investigation of the surface micro cooler was set on the examination of the surface temperatures for different heat fluxes and different velocities of the water in the micro channels. The experimental results of these surface micro coolers are summarized to characteristic maps. With this characteristic maps it is possible to determine whether a micro surface cooler can be used for a specific application.

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