Experimental analysis of a solar flat plate collector for enhancement in thermal performance using solar turbulence generators

Solar air heaters are now-a-days used in space heating as well as a process heating in domestic applications. Since it is a renewable energy conversion device, enhancement of such devices assumes greater significance due to its lower efficiency. In this analysis, an attempt is made to improve the effectiveness of the solar collector by incorporating turbulence generating devices on the side walls of the air heater duct, which are energized by solar photo voltaic cells. The turbulence generators introduce swirl motion around them which enhances mixing of the hot and cold side of the fluid, resulting in enhanced heat transfer. It is noted from the study that with an increase in mass flow rate inside the duct, air heater with turbulence generating devices shows a remarkable improvement in the heat transfer with significant improvement in temperature rise across the duct compared to that of the smooth duct configuration. These results corroborate well with the corresponding drop in absorber plate temperature. However, with an increase in mass flow rate corresponding to the lower rotational speed of turbulence generators, the air heater with turbulence generators show a decrement in the heat transfer capacity. This results in reduction of the heat transfer capability and leads to lower temperature rise.