Recent Developments and Advancements in Solar Air Heaters: A Detailed Review

Abstract

The scientific literature extensively mentions the use of a solar air heater (SAH) by utilizing solar energy for heating purposes. The poor heat-transfer rate of an SAH with a flat plate is caused by developing a laminar sub-layer near the heated base plate. The plate temperatures improve significantly, resulting in losses and a decrease in performance. The passive approach entails the placement of fins/turbulators/pouring material/ribs to the surface where the boundary layer forms to disrupt it. Artificially roughened SAH for gathering and efficiently using solar radiations for thermal purposes is extensively described in the literature. This paper includes a thorough literature overview of the history, basics, roughness evolution, forms of SAH, and recent breakthroughs in thermal performance improvement techniques for SAH compiled by several researchers. This paper uses a comparative evaluation of several roughness geometries and kinds of SAH to uncover thermohydraulic performance factors that may be considered in future research to pick the optimal configuration.

Waste to Energy Management for Sustainable Development

“…WTE is a vast subject that covers a range of energy conversion methods. The environmental and energy industries will collaborate under this new generation management system to find answers to the waste and energy concerns [13] (Table 1). 3 Equipment Required For Fabrication…”

Comparison of CFD Results of Smooth Air Duct with Experimental and Available Equations in Literature

“…Liquid solar heaters are susceptible to a number of issues, like corrosion, fluid leakage, and energy to pump fluid. By employing air instead of liquid in solar heating equipment, all of these issues are solved [11] Main component of solar air heat is duct in which absorber plate is placed to absorb solar radiations through glass, placed at the top of duct. The air is circulated through forced convection, absorbs heat and used for space heating and other purposes [12].…”

“…There are other ways to increase thermal efficiency, including multiple passage, multiple glazing, blockages, baffles, fins and obstructions, but the use of artificial repeated-rib roughness is the one that is most commonly praised and acknowledged. [11]. For enhancing effective efficiency and thermal efficiency, earlier works on SAH have used artificial roughness [10] , wire mesh, obstacle, blockages [14][15], ribs [16], phase change materials [17], duct modification, corrugated surfaces, multiple glazing passes, porous media, and other techniques [18].…”

Double Pass Solar Air Heater: A Review

“…A solar air heater (SAH) is a setup that is generally used for heating the air that comes from the ambient and is further utilised for domestic and industrial processes and applications like room heating, water preheating, and the drying of different products, among many others [13]. The low thermal heat transfer coefficient between SAH and ambient air comes from the environment and is a major Several methods have been used by various research scholars and scientists working in the field of SAHs, such as the use of artificial roughness on the base plate, the use of different colours on the base plate and within the SAH to improve absorption coefficient, the use of extended surfaces, wedges, turbulators, secondary flow, multi-glazing, and multi-pass for increasing the travelling time of air within the duct and creating better heat transfer between the duct and the surrounding environment [14]- [20].…”