High power transient thermal management with dynamic phase change material and liquid cooling

Liquid cooling systems offer effective thermal management for steady-state heat fluxes. Conventional liquid cooling loops are often oversized to handle peak loads, leading to unused cooling capacity during lower power operating conditions. This challenge is particularly acute in applications with short-duration high-power loads. This study explores the integration of dynamic phase change material (dynPCM) into a liquid-cooled cold plate to enhance cooling performance during pulsed heat loads. DynPCMs maintain high cooling over long duration and has significant advantages over conventional PCMs in terms of energy density and power density. The research leverages double-sided cooling of an electronics package, utilizing the liquid-cooled cold plate on one side of the electronics and dynPCM on the opposite side. Experiments and finite element method (FEM) simulations evaluate the system thermal performance under varying power input, coolant flow rate, inlet temperature, pressure applied to the dynPCM, and PCM properties. DynPCM integration reduces the maximum device temperature by up to 29% and lowers coolant temperature rise by 34%, outperforming cooling using the cold plate alone. FEM simulations predict further performance improvements in operating conditions beyond the measured cases. The dynPCM-assisted cooling method improves system hydraulic efficiency by reducing the required coolant flow rate and pressure drop while maintaining performance comparable to a conventional cold plate, leading to lower power consumption from the coolant pump. The improved cooling and hydraulic efficiency highlight the potential of dynPCM-assisted cooling to reduce system size, weight, and energy use for transient electronics heating.