Fabrication of Cu@G composite coatings and their pool boiling performance with R-134a and R-1234yf

Abstract

The present work explores the pool-boiling performance of refrigerants (R-134 and R-1234yf) on the plain Cu and graphene nanoplatelets (G) reinforced Cu matrix (Cu@G) composite coated heating surface. A two-step electrodeposition technique was employed to prepare microporous Cu@G composite coatings. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) studies confirmed the successful fabrication of microporous structure of Cu@G composite coatings. Surface profilometer investigation was done to know the surface roughness of prepared Cu@G composite coatings. Pool boiling experiments were carried out with increasing heat flux from 8.80 kW/m2 to 61.25 kW/m2 at a saturation temperature of 10°C. Test results of R-134 and R-1234yf were compared. The experimental results revealed that the heat transfer coefficients (HTCs) of R-134a were higher than R-1234yf for plain Cu and Cu@G composite coated heating surfaces.