Exploring the thermal performance of a solar air heater with a V-corrugated and shot-blasted absorber plate comprising nano-enhanced phase change materials

Abstract

This research aims to carry out an experimental investigation into the performance of a solar air heater using phase change materials in combination with V-corrugated absorber plates and shot blasting. This shot blasting approach is applied to interrupt the boundary layer thickness of the absorber plate material it will increase the absorbance of the material. This study incorporates the analysis of four distinct absorber plates namely (i) V-Corrugated Plate (ii) V-Corrugated with shot blasting, incorporating PCM (iii) V-Corrugated with shot blasting, including NEPCM (0.6 %) (iv) V-Corrugated with shot blasting, including NEPCM (0.9 %). In this study, Paraffin wax was selected as the base PCM, and MWCNT dispersed into base PCM with different weight fractions. The nano-enhanced phase change material with a concentration of 0.9 wt% examined that the latent heat of melting and solidification experienced a significant augmentation. This enhancement resulted in a maximum increase of 12.5 % for melting and 8.2 % solidification was attained at 0.9 % of MWCNTs compared with paraffin wax. The average exergy efficiencies of V-corrugated plate attains an efficiency of 1.023 %, V-corrugated with PCM records 1.357 %, V-corrugated with 0.6 % NEPCM attains 1.698 %, and V-corrugated with 0.9 % NEPCM attains the highest efficiency at 2.167 %. The significant enhancement in exergy efficiency observed in NEPCM configurations with volume fractions of 0.6 % and 0.9 % is primarily attributed to two key factors namely enhanced thermal conductivity and improved heat transfer properties. The maximum sustainability index for the V-corrugated design with 0.9 % NEPCM falls within the range of 1.014 to 1.037. The average “Nu” value of 27.5 was achieved under the conditions of a mass flow rate of 0.02 kg/s and the addition of 0.9 % MWCNTs dispersed in paraffin wax.