High performance forced air cooling scheme employing microchannel heat exchangers

In this paper, a high performance forced air cooing scheme is theoretically and experimentally investigated which employs microchannel parallel plate-fin heat sinks and tubes to deliver the air to and optionally from the heat sink. The performance of the cooling system is modeled in terms of thermal resistance, pressure drop, and pumping power. Optimizations are performed and design trade-offs discussed. Tubes are observed to have a significant impact on optimum heat sink design as well as operating point. Sample heat sinks with lateral dimensions of 5×5 cm² and fin lengths of 1.5 and 2.5 cm were fabricated from copper and aluminum foils using a simple assembly process. Fin thicknesses and channel widths of the heat sinks are on the order of 200 and 500 μm, respectively. Thermal resistances as low as 0.2 R/W are measured. Results of the present study are compared to prior works dealing with direct air cooling. The thermal performances achievable using the investigated cooling approach are superior to those attainable using open air cooled heat sinks as well as those employing silicon microcoolers