Analysis of advancement in Solar air heater (SAH) heat transfer expansion methods: A crisp review

Abstract

The thermal efficiency of the solar air heater collectors is minimum when compared with liquid solar collectors due to the presence of a number of losses. There is a need to enhance the performance of these collectors. There are several techniques which are employed on the collectors to progress their performance by attaching different arrangement like turbulators, fins, porous matrix and using phase change material, etc. The modification on the collectors will also help in breaking the thermal viscous layer which is formed on the absorber surface. The thermal hotspots on the surface are reduced by acquainting with better thermal mixing of the fluids. The novel techniques are developed with the most innovative ideas by implementing the tubular collectors, double pass collectors, various geometrical ducts, etc. to reduce thermal losses. The Computational Fluid Dynamics (CFD) has become the effectual procedure to analyze the performance of these collectors. CFD has circumvented the experimental difficulties and is thus cost-effective. The parametric study of the different geometrical configurations supports in obtaining the optimum design and improved efficient device. This paper presents a crisp review of the recent works carried on the solar air heater (SAH).