Electronics cooling

About: Electronics cooling is a research topic. Over the lifetime, 1135 publications have been published within this topic receiving 17608 citations.

Design and Development of a Low-Cost, High Temperature Silicon Carbide Micro-Channel Recuperator

Abstract: Typically, ceramic micro-channel devices are used for high temperature heat exchangers, catalytic reactors, electronics cooling, and processing of corrosive streams where the thermomechanical benefits of ceramic materials are desired. These benefits include: high temperature mechanical and corrosion properties and tailorable material properties such as thermal expansion, electrical conductivity and thermal conductivity. In addition, by utilizing Laminated Object Manufacturing (LOM) methods, inexpensive ceramic materials can be layered, featured and laminated in the green state and co-sintered to form monolithic structures amenable to mass production. In cooperation with the DOE and Pacific Northwest National Labs, silicon carbide (SiC) based micro-channel recuperator concepts are being developed and tested. The performance benefits of a high temperature, micro-channel heat exchanger are realized from the improved thermal efficiency of the high temperature cycles and the improved effectiveness of micro-channels for heat transfer. In designing these structures, the heat and mass transfer within the micro-channels are being analyzed with heat transfer models, computational fluid dynamics models and validated with experimental results. As an example, a typical micro-turbine cycle was modified and modeled to incorporate this ceramic recuperator and it was found that the overall thermal efficiency of the micro-turbine could be improved from about 27% to over 40%. Process improvements require technical advantages and cost advantages. These LOM methodologies have been based on well-proven industry standard processes where labor, throughput and capital estimates have been tested. Following these cost models and validation at the prototype scale, cost estimates were obtained. For the micro-turbine example, cost estimates indicate that the high-temperature SiC recuperator would cost about $200 per kWe. The development of these heat exchangers is multi-faceted and this paper focuses on the design optimization of a layered micro-channel heat exchanger, its performance testing, and fabrication development through LOM methodologies.Copyright © 2005 by ASME

Experimental and Analytical Studies of Reciprocating-Mechanism Driven Heat Loops (RMDHLs)

Abstract: This paper conducts experimental and analytical studies of a novel heat-transfer device, reciprocating-mechanism driven heat loop (RMDHL) that facilitates two-phase heat transfer while eliminating the so-called cavitation problem commonly encountered by a conventional pump. A RMDHL normally includes a hollow loop having an interior flow passage, an amount of working fluid filled within the loop, and a reciprocating driver. The hollow loop has an evaporator section, a condenser section, and a liquid reservoir. The reciprocating driver is integrated with the liquid reservoir and facilitates a reciprocating flow of the working fluid within the loop, so that liquid is supplied from the condenser section to the evaporator section under a substantially saturated condition and the so-called cavitation problem associated with a conventional pump is avoided. The reciprocating driver could be a solenoid-operated reciprocating driver for electronics cooling applications and a bellows-type reciprocating driver for high-temperature applications. Experimental study has been undertaken for a solenoid-operated heat loop in connection with high heat flux thermal management applications. Experimental results show that the heat loop worked very effectively and a heat flux as high as 300 W/cm 2 in the evaporator section could be handled. A working criterion has also been derived, which could provide a guidance for the design of a RMDHL.

Heat transfer coefficient for water cooled heat sink: application for standard power modules cooling at high temperature

Abstract: This study presents an overview of water cooling methods used in the power electronic field. The first one uses the classical method with separated power module and cooling device. The second one deals with high reduction of conductive thermal resistance and could predominately be the final cooling solution in the near future. The last one, foreseen for future applications, consists in designing the power module and the cooling device in the silicon material, improving even more the overall thermal resistance. Each alternative may require a good knowledge of the thermal exchange laws in the heat exchanger. The Nusselt number, as a characteristic thermal parameter proposed in the literature, is not always realistic for all kinds of cooling devices. The work focuses on that correlated value determination taking into account the channel geometry, the fluid flow rate and its temperature. Then, the obtained value is used to make a real optimisation of the cooling device.

hADIABATIC and u’MAX

Abstract: In all electronics cooling situations, and many other practical situations, the surface temperature varies in the stream-wise direction. In these cases, defining the heat transfer coefficient using the adiabatic temperature of the surface instead of the mixed mean temperature of the coolant result in significant benefits. The resulting definition is hadiabatic . The theoretical and practical bases for hadiabatic are presented. Examples of its use in electronics cooling are described to show the operational advantages this approach offers. Turbulence strongly affects heat transfer. A simple, turbulence-based correlation is presented that yields an estimate of the heat transfer coefficient good enough for preliminary design estimates and often as accurate as can be relied upon from CFD calculations using present codes.© 2003 ASME