Enhancement in heat transfer characteristics of solar air heater using composite material as absorber plate

Abstract

The energy is witnessed to be playing a predominant role in satisfying the needs of modern civilization, which is helpful in achieving economical and industrial growth globally. The exhaustion of non-renewable resources at an alarming rate paved way to the crucial exploration of substitutional source of energy. Solar air heater (SAH) is widely in use because of no need of routine maintenance process. This method is the costeffective method for heating applications. Solar energy system has some good and bad characteristics when it is influenced by thermal means. The main drawback of using solar system is the erratic radiation of the sun is made to fall on the absorber plate and so we will not get the sufficient thermal efficiency, even the resource is renewable. To use the solar radiation in the effective way, it is better to construct an effective SAH to produce hot air. The real-time application of SAH is where the need for low heat applications like for drying agricultural, textile and marine products. Assessment of experimental thermal performance of a single pass solar air dryer is compared with a transient computational fluid dynamics studies for flat plate without fins, flat plate with fins and overlay composite absorber plate for two flow rates. Three configurations one with a flat absorber plate without fins, another with a flat plate with a vertical hollow fins placed below the absorber plate and third configuration with an overlay composite absorber plate of copper on the top and aluminum at the bottom are compared against each other for its performance improvement. Effect of mass flow rate and outlet temperature of air are experimentally and computationally analyzed, transient boundary conditions for Computational fluid dynamics (CFD) like ambient temperature, solar insolation are taken from the experimental work, and computational results are in good agreement with experimental results with maximum error percentage of 11.13%. newline