Recent Developments in Optical and Thermal Performance of Direct Absorption Solar Collectors

Abstract

Solar energy is the most promising green energy resource, as there is an enormous supply of solar power. It is considered a good potential solution for energy crises in both domestic and industrial sectors. Nowadays, many types of solar systems are used for harvesting solar energy. Most of the research is focused on direct absorption solar collectors (DASCs) due to their ability to capture more solar energy. The effectiveness of DASCs is dependent on various factors, such as working fluid properties, geometry, and operating parameters. This review summarizes the impact of different design and operating parameters on the performance of DASCs. Many effective parameters are considered and their impact on optical and thermal properties is summarized. The influence of working fluid parameters, such as base fluid type, nanoparticle type, nanoparticle size, nanoparticle shape, and nanoparticle concentration on heat transfer performance, was discussed and their optimum range was suggested. The effects of collector dimensions and many novel design configurations were discussed. The effect of the most important operating parameters, such as temperature, flow rate, flow regime, and irradiance on collector performance, was briefly summarized.

Numerical simulation of nanofluid in central tube of solar collector by two‐phase mixture approach

“…The thermal efficacy of solar systems depends on the absorption properties of the base fluid. 8 Gholinia et al 9 conducted research on water, engine oil, and ethylene glycol by dispersing carbon nanoparticles. The results showed that engine oil exhibited superior temperature and flow characteristics compared to water.…”

A Review on Recent Progress in Preparation of Medium-Temperature Solar-Thermal Nanofluids with Stable Dispersion

“…The direct volumetric conversion and storage of solar-thermal energy as sensible heat in the thermal storage fluids avoid the slow heat transfer from the outer surfaces to the inner storage media and homogenize the temperature distribution within the storage media [24]. Such design thus can avoid the potential overheating of the outer surface, and minimize the radiation and convection heat loss from the solar collector, which in turn enables achieving high energy conversion efficiency at medium-to-high temperatures [25]. Such nanofluid-based DASCs not only improve the sustainability of solar-thermal systems [26], but also can be coupled with photovoltaic and solar steam generation systems for multifunctional applications [27].…”