Comparison and optimization of single-phase liquid cooling devices for the heat dissipation of high-power LED arrays

The thermal and hydrodynamic performance of liquid active cooling devices was investigated for possible applications in the thermal management of high-power LED arrays fabricated on InGaN/sapphire chips. A microjet solution and a series of minichannel cold plates were investigated using full 3-D numerical simulations. An optimization based on entropy generation minimization was performed with goal of reducing the frictional pressure losses in the various minichannel geometries evaluated. The effective thermal resistance, pressure drop and pumping power requirements were calculated for all the cold plates investigated. The results of the entropy generation minimization process indicated that the minichannel cold plate had a lower flow resistance than the base design reported in previous investigations. Due to the different length scales presented in this problem, a small-scale model was developed using a simple thermal resistance formulation for the chips, in order to calculate the chip junction temperature at different operating conditions. Overall, it was found that the minichannel cold plate design is a better thermal management option than microjets for the cooling of high-power LEDs.