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

Abstract

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°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.

Evaluation of the potential of nanofluids containing different Ag nanoparticle size distributions for enhanced solar energy conversion in hybrid photovoltaic-thermal (PVT) applications

“…Therefore, by controlling the loading concentration of the nanoparticles, and hence the internal structure of the nanofluid, up to 45% of the solar irradiance can potentially be absorbed and converted into electrical and thermal energy (figure 4(b)). It is feasible to consider that, through further refinement of the particle geometries, flow rate conditions, and the collector architecture, higher collector performances could potentially be achieved [13,14,25,31,49]. However, such investigations are outside the scope of this current work.…”

“…These issues can be tackled by exploiting the capability of nanoparticles to modulate light-matter interactions at the nanoscale. Thus, the thermal and/or optical properties of a base fluid (any conventional liquid) can be selectively augmented to increase its performance [24,25]. This can allow for conventional HTFs such as water to be repurposed for highperformance PVT applications through careful control and consideration of the nanoparticles size, shape, and distribution throughout the base fluid [26,27].…”

Experimental investigation to thermal performance of different photo voltaic modules for efficient system design

“…The results revealed that the output performance is reduced to 22 percent.After a continuous ten weeks of dust assertion on PV module, mass to volume ratio of dust on the surface from 0.01 g/m 2 at the beginning but it was gradually changed to 6 g/m 2 at the last day of this experimental study [55]. The transmission coefficient and energy conservation performance were reduced caused by dust assertion on the exterior upper layer of PV system [41,51,[56][57][58][59][60][61]. The rate of reduction in the output efficiency of a crystalline PV system is directly corresponding to quantity of dust assertion on the surface, is equal to 25% per micrometer.…”