Effect of Wind Velocity on Wind Loss Coefficient and Top Loss Coefficient of Single Glazed Flat Plate Collector―An Experimental Study

摘要

Effect of wind velocity on wind induced convective heat transfer coefficients and top loss coefficients is investigated on a 1.21 m x 0.71 m x 0.16 m size single glazed experimental research collector. The collector is equipped with 1 kW reflective heaters kept below the absorber. The temperatures at various points are measured with 48 chromel-alumel thermocouples. The natural wind is created in a laboratory by three pedestrials fans and wind velocity is varied from 1.0 to 5 m/s along the principal axis and parallel to the collector. The input to the collector is varied from 200 W to 700 W. The wind loss and top loss coefficients are evaluated under steady state condition from energy balance equation. The variations of these coefficients are presented as a function of wind velocity on different (T_p― T_a) isotherms.