Thermal Characteristics Determination of a New Type of Air Heater, Using Porous Radiant Burner Considering Gas Radiation Effects

In the present study, a new type of air heater is developed using porous radiant burner. The air heater has three layered structure and works based on energy conversion method between gas enthalpy and thermal radiation. The main layer operates as a porous radiant burner, where the energy of combustion is converted into thermal radiation and emitted towards the two low temperature sections. The porous media in these sections are heated by absorbing the emitted radiation and the low temperature air flowing through the media is effectively heated by the reverse conversion from thermal radiation into gas enthalpy. In order to investigate the heat transfer characteristics of the heater, the coupled energy equations for the gas flows and the porous layers for each section are solved numerically by an iterative method. The Computational results show that this type of air heater has a very high efficiency, especially when the porous layers have high optical thickness.