Experimental analysis of solar air heater using polygonal ribs in absorber plate integrated with phase change material

Heat transfer enhancement in solar air heater has been investigated by implementing rough surfaces in the absorber plate. We use paraffin wax is used as phase change material integrated with solar air heater as a thermal energy storage system. A maximum convective heat transfer is attained during the daytime and retained as latent heat to discharge heat during OFF radiation. In this investigation, two types of absorber plates were employed such as flat and polygonal-shaped ribs at the test section. Further to investigate the heat transfer enhancement, the research was conducted with and without phase change material. The study was carried out at the mass-flow rates of 0.062 kg/s, 0.028 kg/s, and 0.01 kg/s to ascertain the enhancement of thermal efficiency and heat discharge duration. The temperatures of absorber plate, Tp, ambient Tamb, outlet, Tout, and phase change material along with solar intensity, I [Wm?2], were taken as the main parameters. The research reveals that the absorber plate with polygonal ribs tested with phase change material yields a higher temperature of 77?C with a mass-flow rate of 0.062 kg/s during peak radiation. Discharged heat energy from phase change material to absorber plate for 3.5 hours with a maximum temperature of 7.1?C.