Abstract
With increase in cost of gaseous fuels and depletion in their reserves, it has become essential to further improve the efficiency of the commercial gaseous burners which generally have low thermal efficiency and high emissions. Porous Radiant Burner (PRB) is one such emerging technology which assists lean combustion, thus yielding clean burning and improved thermal efficiency in comparison to a conventional free-flame burner i.e., CB. This paper presents an experimental investigation on LPG combustion employing a simple and yet novel technique of clustering 3 individual bi-layered PRB. Each PRB is of 70 mm diameter with a SiC foam as combustion layer and a porous alumina filter as preheat layer. Transient analysis of the surface temperature distribution was conducted to find out the range of its operational stability, that is restricted by blow-off, flashback and flame quenching. Thermal efficiency tests were carried out for a firing rate of 12.56 kW, as per BIS 14612:1999. Concentrations of CO and NOx were measured by confining the flue gases in a hood. The new cluster PRB has a maximum thermal efficiency improvement potential of 19 % over the CB at an equivalence ratio of 0.7. Similarly, it shows improved ability to lessen the CO and NOx emissions as highlighted by 62 ppm of CO and 13.9 ppm of NOx, which was otherwise 264 ppm and 46.9 ppm, for its conventional counterpart. Overall performance of the cluster PRB exhibits a potential replacement to its conventional counterpart.
