PERFORMANCE EVALUATION OF SOLAR AIR HEATER WITH SURFACE MOUNTED OBSTACLES

Abstract

A solar air heater is a simple device to heat air by utilizing solar energy which has many applications in drying agricultural products such as seeds, fruits and vegetables and as a low-temperature energy source. Also, solar air heaters are utilized for heating buildings with auxiliary heaters to save energy in winter-time. In the experimentation Taguchi method is applied.One of the advantages of the Taguchi method over the conventional experimental design methods, in addition to keeping the experimental cost at the minimum level is that it minimises the variability around the target when bringing the performance value to the target value. Its other advantage is that the optimum working conditions determined from the laboratory work can also be reproduced in the real production environment. The present work investigates the effect of the geometrical dispositions of the surface mounted obstacles on the thermal efficiency and pressure drop, taking into account the angular displacement and height of the obstacles in addition to its spanwise and streamwise disposition, heat flux and mass flow rate. The experimental ranges of the parameters were Sx =30-70mm, Sy = 56-206 mm, O = 300-900, h=22-37.5 mm and m=0.01-0.02 kg/s. In the experimentation taguchi method is applied.One of the advantages of the Taguchi method over the conventional experimental design methods, in addition to keeping the experimental cost at the minimum level, is that it minimises the variability around the target when bringing the performance value to the target value. Its other. advantage is that the optimum working conditions determined from the laboratory work can also be reproduced in the real production environment. Here, the main purpose is to design the operating parameters for the solar air heater using the Taguchi method and to see the effect of various parameters on the efficiency and pressure drop.