Boiling heat transfer enhancement with extremely high thermal effusivity of phase change material

Abstract

The phase change heat transfer with high latent heat is the most effective heat transfer mode and it shows superior heat removal capacity under high heat flux conditions. The critical heat flux (CHF) and boiling heat transfer coefficient (BHTC) are the main parameters which determine the thermal limit and efficiency of the cooling system with boiling heat transfer. It is known that many parameters, including wettability, capillary wicking force, roughness, surface geometry, and thermophysical properties, strongly affect the boiling heat transfer performance of the phase-changing heat transfer system. In this study, the focus is concentrated on the effect of thermal effusivity and latent heat of phase change material (PCM) on the boiling heat transfer. The thermal effusivity represents the material’s ability to transfer thermal energy with surroundings. Previous research with graphene nanofluids shows enhanced boiling heat transfer performance in both CHF and BHTC by efficient radial heat dissipation by superior thermal effusivity of graphene. Also, it is confirmed that utilizing the PCM in thermal storage systems shows extremely high effective thermal effusivity with latent heat at near the phase change temperature of phase change materials. Also, the pool boiling experiment with microencapsulated PCM shows enhanced CHF performance due to addition thermal margin from the latent heat of PCM. In the current stage, the effects of the extremely high thermal effusivity of PCM on the boiling heat transfer is investigated by the saturated plate pool boiling experiment under the atmospheric condition.