A bio-inspired, low pressure drop liquid cooling system for high-power IGBT modules for EV/HEV applications

Thermal management of high power density insulated gate bipolar transistors (IGBTs) using a low pumping power is crucial for the development of high-performance electric vehicles (EVs) and hybrid electric vehicles (HEVs). In the present work, the liquid cooling module inspired by a human respiratory system was developed to provide enhanced thermohydraulic performance. The suggested cooling module consists of a multiscale flow manifold connected to a metal foam layer bonded to the bottom substrate of IGBT module. The unique flow path uniformly distributes the coolant to multiple IGBTs with minimizing the required pumping power, while maximizing the heat exchange area. The porosity of the metal foam was determined considering the conflict between the conductive and convective heat flux. The developed cooling module was applied to the single IGBT module, including 6 IGBT/diode pairs generating 1.55 kW of heat. The proposed cooling module provided a low (0.2 K/W) thermal resistance using only ~2 kPa of the pressure drop that is approximately 10 and 100 times lower than that of previously reported turbulator and microchannel systems, respectively. Even when the number of IGBT/diode pairs is increased from 6 to 24 (single to quadruple IGBT modules), only ~8 kPa of the pressure drop was required, which shows the high scalability of the proposed solution. This work will help develop a compact, low pumping power cooling solution for high-performance EV/HEV applications.