Investigations on thermodynamic performance of forced convection solar air heater with packed bed absorber plates

Abstract

The solar air heaters are the special kind of heat exchangers used for convert the solar thermal energy into useful hot air output. The efficiency of solar air heater are low in the range of 20% to 35% due to poor heat newlinetransfer coefficient. Hence, in this research work, an attempt has been made to improve the performance of the forced convection solar air heater using packed bed absorber plate. This is achieved by developing a forced convection solar air heater with necessary instrumentation using three different packed bed absorber plate configurations. The thermodynamic performance was evaluated under the meteorological conditions (latitude and longitude) of Coimbatore city in India during the year 2014. Three newly developed packed bed absorber plate configurations namely; pin-fin absorber plate, triangular tube absorber plate and circular tube absorber plate packed with paraffin wax as phase change materials were investigated and compared its performance against flat absorber plate configuration. The thermodynamic performance was evaluated for an newlineoptimized air mass flow rate of 0.03 kg/s. The parameters such as, outlet air temperature, thermo-hydraulic efficiency, exergy efficiency and pressure drop were considered for performance comparison. The artificial neural network modeling approach was developed for simulating the thermodynamic performance of forced convection solar air heaters to have realistic performance comparison among four absorber plate newlineconfiguration. newline newline