Experimental Investigation for Augmentation of Thermal Performance of Solar Air Collector

Abstract

This paper presents a study of the thermal performance of a solar air collector used to heat the drying air of a fruit and vegetable dryer. The prototype collector could be a viable solution to improve energy efficiency and food security in Burkina Faso and other developing countries, by contributing to the reduction of post-harvest losses and the increase of income for local agricultural producers. The collector is first realized by using black painted cans as air ducts, perforated to increase turbulence, and a glass covering the collection surface. After realization, the collector is connected to the dryer and a measurement campaign is conducted to evaluate the thermal performance of it. The measured parameters are the sunshine and the air temperature by keeping the air speed fixed at 0.3 m/s. The analysis of the results shows an important variation of the air temperature difference going from 0.1°C to 74.4°C, between the inlet and the outlet of the collector for an irradiation which varies between 142 W/m2 and 837 W/m2. The black painted surface of the air ducts as well as the increase in turbulence contributed to improve the efficiency of the collector which varies between 0.94% and 50.68% and allowing to record air temperatures ranging from 27.2°C to 69.2°C inside the dryer. This temperature range is favorable for the drying of most food products.