Influence of Surface Emissivity of Target Environment on Whole Heat Transfer of Porous Ceramics Radiant Burner

Abstract

The heat transfer between a porous ceramic radiant burner (PCRB) and a target environment was studied. The black aluminum pot (BAP) and white aluminum pot (WAP) with an emissivity of 0.72 and 0.22 were experimentally used to obtain the temperature distribution and thermal efficiency of a burner. Under the same heat load, the porous ceramic plate (PCP) of WAP is 79~90 °C higher than BAP, but the measured thermal efficiency of BAP is 15~20% higher than WAP. A heat transfer model for PCRB and pots was established based on the radiant and convection heat transfer theories. This model is applicable to common infrared radiant burners. The heat gain type of the pot was analyzed quantitively, with a relative error of less than 7%. The influence of the pot surface emissivity on the burner and heat transfer change of the pot was discussed, and the solid radiation heat gain of BAP is approximately double that of BAP under the same heat load. For PCRBs whose main heat is from radiation, the pot with a high surface emissivity can achieve better radiation utilization to improve thermal efficiency.