The Effect of the Variation of Volume Flow Rate on the Thermal Parameters of a Solar Air Collector with a Single Pass of Air: Case Study for Laghouat, Algeria

Abstract

The effect of the volume flow rate of the heat transfer fluid (air) on the thermal parameters of the solar air collector with a single air pass without using fins under the absorbing plate have been investigated experimentally and theoretically. We use a new design of solar air collector which aims to optimize these parameters in the region cited above. Our solar air collector was realized at the mechanical workshop at the University of Laghouat, Algeria. We chose five different volume flow rates for five different days. This study shows the evolution of the thermal parameters of the solar air collector as function of the local solar time (Lst) such as: absorber temperature, temperature of the bottom plate, outlet temperature, ambient temperature, solar irradiation intensity and efficiency for a tilt angle of solar collector equal 36.7o. We observe clearly that the daily efficiency and the outlet temperature of our solar air collector increase with increasing of the flow rate (η =8.72% ~ 28.82 % , 60oC ~ 70 oC) exceptly for flow rates 3 and 4 (partial sky condition). The average temperature of bottom plate, the transparent cover and absorber temperature decrease such as: (73 °C ~ 64 °C, 66.5°C ~ 45.09°C, 128°C ~ 124°C) when the volume flow rate is increasing.We observe a good agreement between the values obtained theoretically and those obtained experimentally except for the volume flow rates 3 and 4 (partial sky condition).