Experimental Investigation and Analysis on a Concentrating Solar Collector Using Linear Fresnel Lens

Abstract

Energy is significant factor for the survival and progress of humankind. Solar energy is used as an alternative source of energy for several domestic and industrial applications. Solar energy can be used in industries for quick and efficient water heating purpose or to generate low pressure steam by concentrating more solar energy on a smaller area. This can be done by using concentrating solar thermal collectors. Concentrating collector technologies offer a favourable technique for enormous use of solar energy. It gives higher efficiency compared to non-concentrating collector at high temperature due to its higher concentration ratio and smaller amount of heat losses. Solar energy concentrating technology with linear Fresnel lens is a one of the effective way to utilize solar energy for water heating. A Fresnel lens is a photosensitive piece which can be used as cost saving, light weight substitute to conventional lens. The objective of present work is to investigate and analyse performance of concentrating linear Fresnel lens solar water collector. In the present work, Polymethyl methacrylate (PMMA) sheet was used as Fresnel lens. A Heat loss calculation was carried out at various mass flow rates, with and without Fresnel lens. To study the effects of Fresnel lens on the performance of evacuated tube collector experiments were performed in the wide range of mass flow rates. The system efficiency was increased by 10-17% due to presence of Fresnel lens at different flow rates.