Single-phase microchannel cold plate for hybrid vehicle electronics

Under-hood packaging in hybrid vehicles is highly constrained due to smaller vehicle size and additional electric drive components. Moreover, the increased electrification of hybrid vehicles has resulted in a need for greater electrical power handling capability. These two factors have led to larger power densities (in excess of 200 W/cm²) and related thermal management challenges for future hybrid vehicle electronics. In this paper, the design of a compact multi-device single-phase microchannel cold plate for hybrid vehicle electronics applications is explained. The cold plate design utilizes numerous local multi-pass branching microchannel systems arranged in parallel and then connected in series with optimized global inlet and outlet manifolds for efficient coolant flow distribution and device temperature control. Experimental heat transfer and pressure drop results using a 50/50 ethylene-glycol/water coolant are reported as part of this study, where the average cold plate thermal resistance achieved is 0.112 K/W with 9.03 kPa pressure drop at a coolant volumetric flow rate of 2.5 1/min.