Vol. 2, Issue 11, Part G (2016)

Abstract
The requirement of heat energy for diverse applications can be fulfilled by the effectual conversion of the incident solar radiation through solar thermal gadgets. The central component of any solar thermal gadget is the solar collector, which is used with different absorber materials nowadays for heating fluids. At this juncture, it is essential not only to study the thermal characteristics of the absorber materials but also to estimate the thermal performances of the collectors with different absorber materials for effective utilization in application sectors. In this connection, in the present investigation, three commercially available solar collectors with copper, aluminium and mild steel absorbers were tested as per IS 12933 (Part 1, 2 and 5): 2003. As an integral part of this investigation, the temperature test on black chrome coated copper, aluminium and mild steel fins at the temperature of 175 ⁰C for 2 hours was conducted and it was found that there were no appearances of blistering, rupture and peeling off the coated surface on the absorber plates. The thermal performance test on the solar flat plate collectors of current concern was also conducted and it was found that the instantaneous thermal performances varied from 66.8 to 69.2%, ranged between 62.1 and 65.9% and had a minimum of 58.1 and a maximum of 60.1% for copper, aluminium and mild steel absorber integrated solar collectors respectively for the inlet temperature of 30 ⁰C of the working fluid. It was also found that the instantaneous thermal performances varied from 65.1 to 66.6%, ranged between 61.2 and 62.5% and had a minimum of 54.8 and a maximum of 55.9% for copper, aluminium and mild steel absorber integrated solar collectors respectively for the inlet temperature of 40 ⁰C of the same working fluid. As the thermal performances of the solar collectors could depend on the thermal conductivity of the absorber materials, it could be concluded that either copper or aluminium or mild steel absorber would be used in application sectors as per temperature requirements of the end users.