Thermal Performance Analysis For Three Different Geometric Shapes Of Greenhouse Type Solar Dryer

Abstract

An analytical study was carried out for evaluating and analyzing the thermal performance of three different geometrical shapes of green-house type solar dryers which can be used for date drying. The different shapes are, Quonset shape (SD1), gable-even-span (SD2) and pyramid shape (SD3). The three solar dryers was designed and installed at the Department of Agricultural Engineering, Faculty of Agriculture, Suez Canal University (latitude angle of 30.62°, longitude angle 32.27° and 5m above the sea level) during September 2015. The tested dryers were operated under three different air velocities of 0.5, 1, 1.5 m/s. The thermal performance analysis of the dryers was conducted based on the thermal balance equations. The obtained results revealed that, overall thermal efficiency for the three different solar dryers (SD1, 2 and 3) were (55.6, 52.2 and 51.1%), (62.04, 58.6 and 57.1%) and (50.6, 47.6 and 46.2%) at air velocity of 0.5, 1, 1.5 m/s, respectively. The predicted heat energy for the three solar driers was found to be very close with that measured during the experimental period. From the three different shapes, the study recommended that the Quonset shape (SD1) is the best shape solar dryer due to largest surface area which observed greatest amount of solar radiation, increased solar energy and drying air temperature.