Analysis of a spiral-formed solar air heating system with ceria nanoparticles-enhanced absorber coating

Solar air heating systems are extensively applied in different applications in order to provide hot air using clean energy. In this study, a spiral type solar collector has been proposed, numerically simulated and manufactured. The main aim of this work is investigating the overall performance of a solar collector with spiral type absorber. In the first stage of this work, CFD approach has been used for simulating unbaffled and baffled spiral solar collector. Numerical findings exhibited better thermal performance of the baffled spiral collector. Therefore, in the following step of this survey, baffled spiral collector has been fabricated and experimentally analyzed at different conditions. In addition, ceria nanoparticles have been used in coating process of spiral-formed absorber plate of the system to upgrade the thermal efficiency. Mean thermal efficiency for spiral collector with and without nano-coating was obtained between 46.15 and 67.39%. Mean efficiency enhancement by using ceria nanoparticle coating in the tests made at 0.009 and 0.014 kg/s are 16.79% and 11.05%, respectively. Also, average exergy efficiency of spiral collector was achieved between 10.28 and 14.46%. Average sustainability index of spiral collector was gained in the range of 1.1151–1.1698. The overall findings of this study indicated successful utilization of the developed spiral type solar collector. Moreover, using ceria nanoparticle coating has significant positive effects on improving thermal efficiency of spiral collector. It can be concluded that the developed spiral type solar collector could be used in building integrated applications for providing fresh and heated air. •A new type of spiral-formed solar collector was developed for building applications.•Numerical comparison of baffled and unbaffled collector configurations.•The effect of nanoparticle coating on the performance was experimentally tested.•Thermal efficiency was improved as 46% by raising flow rate and using nano-coating.