Thermodynamic Characteristics and Economic Analysis of a BFG/Pulverized Coal Mixed Combustion Boiler

To solve the problems occurring in a 300 MW tangential blast furnace gas (BFG)/pulverized coal blended combustion boiler, such as overheating of its superheater/reheater and high carbon content in the fly ash, etc., thermodynamic calculations and an economic analysis were carried out. Results show that after the fuel coal is blended with BFG, the in-furnace temperature drops, the exhaust gas volume rises, the absorption of radiation heat reduces, the absorption of convection heat increases, the gas temperatures at and after furnace outlet rise, the exhaust gas temperature increases and the boiler efficiency decreases; after mixing with BFG, the house power consumption rises, but the coal consumption for power generation reduces, which helps to reduce the power generating cost.