Comparative study on W-shaped roughened solar air heaters by using booster mirror

Abstract

The utilization of unnatural rouged in solar collectors with higher amount of solar radiation provide higher thermal performance and effective transfer of heat from the collector to the air. The present investigation deals accompanied by the comparative study for the enhancement in percentage of solar radiation through booster mirrors and also due to the W-shaped artificial roughness present in the collector in the direction perpendicular to the flow of air. Heat transfer measurements were conducted for a fully developed turbulent flow in a rectangular plate accompanied by its bottom wall blindly holed with circular geometry. The test plates were designed with its bottom wall was made of a rectangular GI plate of length 636 mm, breadth 121 mm and width125 mm. Experiments were carried out based on different geometries. It was found that there is an increment in heat transfer was found in rectangular plate accompanied by W-shaped roughened plate with booster mirror as compared to that of the transverse one. An increment in solar radiation of approximately 30% have been achieved over the normal solar radiation due to booster mirrors which results 9% to 17% more amount of heat collected. This paper is one such effort of experimental investigations of heat transfer in which the effect of booster mirror arrangements on the heat transfer has been presented. This paper investigates on the comparative thermal execution of W-shaped roughened solar air heater with booster mirror.