An Optimum Performance of A Flat-Type Solar Air Heater With A Porous Absorber

Abstract

This investigation is concerned with the design and performance of a flat solar air heater in which air flows perpendicular from a vented transparent cover through a porous absorber plate. The design phase involves a stability analysis to determine the critical distance (maximum allowable distance) between the absorber and transparent plates, for suppressing convection currents, under a variety of environmental and operating conditions. These results are expected to be useful to designers of solar collectors. In addition, the thermal performance of this solar heater at its optimum design conditions was computed for a wide range of system parameters illustrating the contributions of conduction and radiative modes of heat transfer. The results indicate that best operating efficiency can be obtained when running the collector with mass flow rate, m > 40 Kg/m2 hr.