Keywords: packed bed solar air heaters, porosity, thermal efficiency, double flow solar air heaters, numerical modelling, solar energy, solar power, mathematical modelling, heat transfer coefficient, mass flow rate
A numerical evaluation of thermal performance of double flow packed bed solar air heaters
In this paper, double flow packed bed solar air heater was investigated theoretically and experimentally. A numerical model for the air heater was presented. Numerical calculations had been performed under Hamirpur (latitude, 31°25' to 31°52' North) prevailing weather conditions. A mathematical models based on the volumetric heat transfer coefficient have been developed. To solve this model and to provide an iterative approach, forward difference method of finite difference scheme is employed. The theoretical predictions indicated that the agreement with the measured performance is fairly good. The effect of mass flow rates of air on thermal and effective thermal efficiencies of the double flow with and without packed bed solar air heaters were also investigated. The results showed that the double flow packed bed solar air heater is about 78.8% more efficient compared to the double flow without packed bed solar air heater.