Embedded cooling with 3D manifold for vehicle power electronics application: Single-phase thermal-fluid performance

Abstract

Single-phase thermal-fluidic performance of an embedded silicon microchannel cold-plate (25 parallel channels: 75 mu m x 150 mu m) with a 3-D liquid distribution manifold (6 inlets: 700 mu m x 150 mu m) and vapor extraction conduits, is investigated using water as working fluid. A 3D manifold is fabricated from silicon and bonded to a silicon microchannel substrate to form a monolithic microcooler (mu-cooler). A metal serpentine bridge (5(2) mm(2) of footprint) and multiple resistance temperature detectors (RTDs) are used for electrical Joule-heating and thermometry, respectively. The experimental results for maximum and average temperatures of the chip, pressure drop, thermal resistance (as low as 0.68 K/W), average heat transfer coefficient (similar to 30,000-50,000 W/m(2) K) for flow rates of 0.03, 0.06 and 0.1 l/min and heat fluxes of 60, 100 and 250 W/cm(2) are reported. The embedded microchannel-3D manifold mu-cooler device is capable of removing 250 W/cm(2) at a maximum temperature of 90 degrees C with less than 3 kPa pressure drop for a flow rate of 0.1 l/min. The results from conjugate thermal-fluidic numerical simulations agree well with the experimental data over the wide range of heat fluxes and flow conditions. The numerical simulation results also hint at the possibility of removing up to similar to 850 W/cm(2) using single-phase water at a maximum temperature of 166 degrees C at the same pressure drop and flow rate. This offers a very attractive strategy/option for cooling of high heat flux power electronics using single-phase water. (C) 2018 Published by Elsevier Ltd.