A mathematical model of thermal performance of a solar air heater with slats

A mathematical model for computing the thermal performance of a single pass flat-plate solar air collector is presented. Air channels were formed by providing metal slats running along the circulated air passage linking the absorber plate by the bottom one in an endeavor to enhance the thermal efficiency of the solar air collector. A mathematical model, therefore, is developed by which the influence of the addition of the metal slats on the efficiency of the solar collector is studied. A computer code that employs an iterative solution procedure is constructed to solve for the governing energy equations to estimate the mean temperatures of the collector. The effect of volume airflow rate, collector length, and spacing between the absorber and bottom plates on the thermal performance of the present solar air heater was investigated. Furthermore, a numerical comparison of the present design with the most common type of solar air heaters is conducted. The results of the comparison have indicated that better thermal performance was obtained by the modified system.