Fabrication and characterization of nano structured honeycomb absorbers and thermal analyses on solar air heating collector

Abstract

Fabrication of nano structured absorber is mandatory for reaping the enhanced thermal performance of solar collectors. In this connection, the nano carbon and aluminium composite was coated on aluminium substrate, which was similar to the hexagon shaped honey comb, and the solar absorber was developed. It was characterized through X-ray Diffractometer (XRD), Fourier Transform Infrared (FTIR) spectrometer and UV–Visible spectrophotometer (UV). It was also thermally analyzed not only in outdoor conditions but also in stagnant conditions in solar air heating collector. The research results pertaining to characterization of solar absorber showed that the crystallite size was in nano ranges and the nano particles had face-centre cubic structure. The research results pertaining to characterization of solar absorber also showed that the nano composite had excellent absorption in UV and visible region. The research result related to thermal analysis in outdoor environment revealed that the enhancements of temperature on solar absorbers coated with carbon and aluminium nano composite in the mass ratio of 60:40, 70:30 and 80:20 were 23.5oC, 25.1oC and 24.4oC respectively. The research result related to thermal analysis in stagnation environment also revealed that the enhancements of temperature on glass cover, carbon and aluminium nano composite coated absorber and working fluid were 69.4oC, 110.6oC and 99.0oC respectively. On the basis of research outcomes, it could be concluded that nano carbon and aluminium composite coated solar absorber would be used for photo thermal applications due to their desirable optical and thermal properties. It could also be concluded that nano carbon and aluminium composite coated solar absorbers would be used in photo thermal appliances due to their positive impact on thermal performances.