Performance Investigation of a Solar Thermal Collector Based on Nanostructured Energy Materials

The convective and conductive heat transfer between the solar collector and working fluids make photothermal performance limited, and result in a higher rate of heat loss from the surface of the conventional absorber to the surroundings. Direct absorption solar collectors (DASC) are a favorable alternative for their improved photothermal performance. In this study, a simulation based on the performance of a nanostructured solar collector has been carried out using TRNSYS. The connective and conductive heat transfer from direct solar collectors were improved by using nanofluids and three different nanostructured materials, CuO, GO, and ZnO, in this study. The analysis determines the outlet temperature of the working fluids that passed through the direct solar collector. The TRNSYS model consists of a direct solar collector and weather model for Lahore city, the simulations were performed for the whole year for 1,440 h. The stability of these nanostructured materials in the water was investigated by using a UV-Vis spectrophotometer. Various performance parameters of direct solar collectors were determined, such as variation in outlet collector temperature and heat transfer rates. The numerical model is validated with experimental results. A maximum outlet temperature of 63 degrees C was observed for GO-based nanofluids. The simulation results show that for the whole year, nanofluids improved the performance of direct solar collectors. Significant improvements in the heat transfer rate of 23.52, 21.11, and 15.09% were observed for the nanofluids based on nanostructures of CuO, ZnO, and GO respectively, as compared to water. These nanostructured energy materials are beneficial in solar-driven applications like solar desalination, solar water, and space heating.