THERMAL BEHAVIOR OF A NEW TYPE OF MULTI-LAYERED POROUS AIR HEATER

Based on an effective energy conversion method between gas enthalpy and thermal radiation, a multi-layered type of porous air heater has been proposed. In the five layered structure which is analyzed in this work, there are five porous layers which are separated by four quartz glass windows. The main layer operates as a porous radiant burner that products a large amount of thermal radiative energy and in the other layers, the energy conversion process between gas enthalpy and thermal radiation takes place. In order to obtain the thermal characteristics of the heater, the coupled energy equations for the gas flows and porous layers are solved numerically by iterative method. The two-flux radiation model is used for computing the radiative fluxes from a solid matrix. Computational results show a very high efficiency for this type of porous air heater although it has a very simple structure.