Pool boiling heat transfer of R-600a on plain copper and Cu@GPL porous composite coating surfaces

Abstract

In this work, nucleate pool boiling experiments were performed on the plain copper and graphene nanoplatelets reinforced Cu matrix (Cu@GPL) porous composite coatings using saturated refrigerant R-600a. The Cu@GPL porous composite coatings were fabricated by a two-step electrodeposition technique. Copper sulfate pentahydrate as a source of Cu and graphene nanoplatelets (GPL) as reinforcing element were used as starting materials for fabrication of Cu@GPL porous composite coatings. The effect of coating parameters such as surface roughness, coating thickness, and porosity on the heat transfer coefficients (HTCs) and boiling characteristics of refrigerants was investigated and presented in detail. The heat transfer coefficient of Cu@GPL porous composite coating was enhanced approximately 2.36 times than that of the plain copper heating surface. The augmentation in the HTCs is primarily due to an increase in surface roughness, coating thickness, porosity and active nucleation of the Cu@GPL porous composite coatings.