Experimental assessment of a solar dryer enhanced by a porous absorber plate and PCM heat storage

This research presents an experimental investigation into a double-pass counter-flow solar air heater (DCSAH) incorporating a copper foam absorber plate and PCM heat storage for drying purposes, conducted with a no-load case under Iraq's meteorological conditions in Baghdad (Latitude 33.3⁰N). A total of 36 kilograms of paraffin wax serves as the phase change material, divided equally into two portions and enclosed within separate heat exchangers. The investigation examines the effects of mass flow rate, PCM utilization, and incident solar radiation on various parameters, including outlet air temperature, heat gained, thermal efficiency, benefit factor, and pressure drop across the solar collector. A comparative analysis is performed with a flat plate solar dryer featuring a traditional absorber plate. The findings reveal that, compared to a flat absorber plate, the DCSAH's thermal efficiency improves by (15%, 19%, and 22%) for air mass flow rates of 0.0076, 0.0118, and 0.0136 kg/s, respectively, when equipped with a copper foam absorber plate without PCM. Furthermore, the benefit factor surpasses 1 for an air mass flow rate of 0.0118 kg/s. Comparative analysis with previous studies indicates good agreement between the findings of this study and prior works.