Improve the performance of a solar air heater by adding aluminum chip, paraffin wax, and nano-SiC

Abstract

In this study, a solar air heater was proposed to suit the atmosphere of the city of Baghdad in winter. In this heater, aluminum chip and tubes filled with nano-silicon carbide (SiC) added to paraffin wax to improve its thermophysical properties were used. The density and viscosity of nano-SiC + paraffin were subjected to limited change because of the added nanoparticles. The product's thermal conductivity increased by 18.2% by adding 3 wt% of nano-SiC. The heat capacity of the composite material decreased by 4.5% and their effect on the solar air heater performance was limited. Practical outdoor tests have proven the suitability of the proposed air heater to work in the weather conditions of Baghdad. The use of the chips improved the heater performance and accelerated the air to heat up so that the warming load on the composite material tubes was decreased at morning hours. The tested air heater temperatures reached high degrees and continued to work for at least 3 h after sunset, despite the heater limited measurements compared to air heater without chip and nano-SiC-paraffin.