Solar radiation effect on PCM performance in the building applications: The collector energy-saving potential using CF-MWCNTs and CF-GNPs

Abstract

In this study, a hot and desert location with an annual temperature of 27.1 ? and a very high radiation intensity of 2143 kWh/m(2), a solar system (ES) was approved to provide building cooling necessities. The cooling system, by connecting to the solar system, supplied a part of its required energy. The outer layer of the building walls was equipped with PCM (SP-21EK) with a melting point of 21-23 and latent heat of 170 kJ/kg. In the solar system, water was filled to absorb energy and then a combination of CF-MWCNTs and CF-GNPs nanoparticles were injected to the solar system to improve effectiveness. In July, when the radiation intensity was very high, the combination of PCM and SC condensed energy consumption (EC) by up to 46.48%. The presence of CF-MWCNTs and CF-GNPs at 0.1 wt% was useful in all conditions (2, 3 and 4 lit/min). In this case, the EC reduction was in the range of 360 to 1026 kWh. At lower concentrations, the nanoparticles not only were not worthwhile, in some cases increased EC by 937 kWh.