Numerical modeling and experimental validation of a phase change material-based compact cascade cooling system for enhanced thermal management

Abstract

The thermal performance of phase change material (PCM)-based compact cascade cooling systems with an integrated heat sink was experimentally evaluated using heat-transfer measurements under constant heat flux. Numerical calculations were also performed to investigate the fundamental mechanism of the cascade cooling approach using multiple PCMs (i.e., paraffin wax) with different melting points. This structure facilitated cooling via hierarchical heat exchange without additional energy consumption. The experimental results of the cascade cooling system demonstrated that the peak temperature within a fin decreased from 123.4 to 107.2 degrees C in one heat-supply cycle owing to the latent heat adsorption during a phase change in the PCMs. Particularly, the cascade cooling system reduced the peak temperature by approximately 13.1% compared with natural convection in air. In addition, the time taken to reach the maximum allowed temperature from the peak temperature was decreased by 45.0% because of the larger heat capacity and cascading heat exchange of PCMs. This implies that the lifetime of a system can be increased and failure can be prevented. Improved thermal performance was demonstrated after repetitive heating-cooling cycles. Furthermore, it was numerically demonstrated that a PCM nanocomposite can reduce the heat accumulation because of the low thermal conductivities of PCMs.