Experimental investigation of single pass solar air heater with reflectors and turbulators

Abstract In this study, the effect of incorporating turbulators and external mirrors into a newly single pass Solar Air Heater (SAH) was investigated experimentally. Aluminium cans were stacked over the absorber plate and used as turbulators to enhance the heater efficiency. The external mirrors are utilized to improve energy input to the SAH. The effect of external bottom and top mirrors on the SAH performance is studied. Three models of absorbing plates had been tested after designing them. The first one is a flat plate without cans (turbulators), the second one is a flat plate with cans in aligned arrangement configuration and the third one is flat plate with cans in staggered arrangement configuration. A comparison between the efficiency of the modified SAHs air heaters with and without reflectors and the conventional SAH were carried out. In addition, guide vanes were attached to the inlet of a heater for ensuring better distribution of air above the absorber surface. Typical ranges of air Mass Flow Rate (MFR) are employed from 0.02 to 0.05 kg/s. Results showed that the maximum daily efficiency of the proposed SAHs was about73.4% at 0.05 kg/s for staggered heater with external reflectors and guide vanes.