EFFECT OF CHANGES IN COAL COMPOSITION ON AIR FUEL RATIO IN CFB BOILER

This study focuses on the combustion process of coal in a Circulating Fluidized Bed (CFB) boiler, emphasizing the crucial role of the oxidation reaction between coal and combustion air. The design of the CFB boiler is meticulously conducted, incorporating calculations for fuel requirements, combustion values, air, and limestone demands, as well as addressing parameters such as combustion gases, solid waste production, fluidization speed, combustion efficiency, and boiler efficiency. To generate 75 tons/hour of steam, the optimized coal flow rate is determined to be 3.82 kg/s, utilizing coal particles with a size of 6 mm. The combustion process necessitates an air supply of 46.34 kg/s at a temperature of 130°C, with a fluidization velocity of 4.23 kg/s. The resulting gas flow rate from the combustion process is 50.14 kg/s, reaching a temperature of 1099.76°C. The ash flow rate is calculated to be 0.38 kg/s. The designed combustion process demonstrates impressive efficiency levels, with a combustion efficiency of 95%, and a boiler efficiency of 89%. These findings contribute to the understanding and optimization of CFB boiler systems, offering insights into efficient energy production from coal combustion.