Experimental Investigation of the Effect of Feeding System on the Performance at Pellet-Fuelled Boilers

Abstract

Depending on the growing industry and the population, energy needs are increasing day by day. This issue makes it necessary the use of renewable energy sources as much as possible. There is a growing interest in pellet fuel and pellet-fired combustion systems, which are one of the renewable energy sources. In this work, performance analyzes of pellet-fueled boilers with two different feeding systems (horizontal-fed and top-fed) and two different flue gas outlet positions were carried out and results were discussed. Emissions of O2, CO2, CO and NOx and flue gas temperature were measured at a certain point of the chimney. Boiler thermal efficiencies were calculated and compared with each other. Direct and indirect methods were used to calculate thermal efficiency of boilers. Results showed that the flue gas temperatures were about 110 °C in the top-fed boiler and 138 °C in the horizontal-fed boiler. The thermal efficiency of top-fed boiler was higher than horizontal-fed boiler. In the top-fed boiler, CO and NOx emissions were lower than the horizontal-fed boiler. Generally, the top-fed boiler showed better performance and lower emission characteristics than horizontal-fed boiler.