Performance study of a novel solar air collector

A novel solar air collector of pin-fin integrated absorber was designed to increase the thermal efficiency. According to experimental results, the average thermal efficiency of twenty-five kinds of pin-fin arrays collector reach 0.5-0.74 compared to the solar transmittance of 0.83 for the glazing. A correlation equation can be put forward to reflect the maximum thermal efficiency (eta(max)) of twenty-five kinds of pin-fin arrays collectors as function of dimensionless pin-fin span (s/d) and dimensionless pin-fin height (h/d). By theoretical calculation, the mathematic models of thermal efficiency of twenty-six collectors including flat-plate collector are obtained representing the influences of solar irradiation and inlet conditions of air stream on thermal efficiency. In the performance analysis of varying flow rate on PZ7-11.25 pin-fin arrays collector, the correlation equation on heat transfer coefficient is obtained and the efficiency variation vs. air flow rate is determined in this work. (C) 2010 Elsevier Ltd. All rights reserved.