Mathematical model of the CFB boiler co-fired with coal and biomass

The paper presents a mathematical model of CFB (Circulating Fluidized-Bed) boiler co-fired with power coal, low-grade coal and biomass. The model based on the mass and energy balance equations. Calculation algorithm uses the method included in the European PN-EN-12952-15 Standard (applicable in Poland) and the German DIN 1942 Standard. Parameters and consumption of fuels burning in the boiler (except primary fuel), temperature, volume fraction of oxygen in flue gases, mass fraction of combustible elements in slag and dust as well as parameters of the combustion air are the input data. The mathematical model equations for the boiler are used to calculate the power efficiency, energy losses in the boiler and the consumption of primary fuel. Exemplary calculation results obtained with the aid of the model are presented in this paper.