Publication

Abstract : The primary challenge in widely adopting solar air heater (SAHRR) for the drying of food and agricultural products lies in the intermittent nature of solar radiation. Fluctuations in solar radiation intensity and the occurrence of off-sunshine hours notably diminish the thermal performance (TPH) of SAHRR. This paper reports the results of experimental investigations carried out on downward SAHRR with sensible energy storage (SES) medium (spherical pebbles of diameter 20 mm). To conduct indoor experimental investigations on SAHRR, the experimental setup features a solar simulator equipped with halogen bulbs, dimmer stats, and flow control devices. To comprehend the influence of SES mediums on the performance of the SAHRR, the obtained outcomes are compared with those of a conventional SAHRR sharing similar dimensions (baseline case). The results suggest that a downward SAHRR equipped with an integrated SES medium can raise the air temperature by 2 to 9°C above the ambient temperature for a 2-h period after shutting off the solar simulator at constant mass flow rate. SAHRR with SES medium exhibits the ability to produce hot air within the temperature range of 41–53°C, making it suitable for applications such as space heating and the drying of food products. The economic assessment carried out in the present study indicates that the payback period of the SAHRR with SES medium is 52 months.