METHODS FOR CONTROLLING FUEL MIXTURE COMPOSITION TO STABILIZE FLUE GAS VOLUME AND IMPROVE ENERGY EFFICIENCY OF BOILER PLANTS

Summary

This article investigates the influence of gas fuel mixture composition and fuel-air system parameters on the formation of volume, temperature, and chemical composition of flue gases in boiler plants. Two methods for regulating thermal load are considered: stabilization of flue gas volume and maintaining a constant volumetric supply of the fuel mixture under conditions of varying the fraction of the low-calorific component. Based on a mathematical model that accounts for mixture enthalpy, adiabatic combustion temperature, and the chemical composition of producer gas, numerical dependencies of combustion product parameters on the proportion of alternative gas have been obtained. The results show that increasing the proportion of low-calorific fuel leads to a decrease in the share of air and inert gases in the mixture, which causes an increase in adiabatic temperature and heat release per unit volume of flue gases. At the same time, the required fuel mixture flow rate increases significantly, necessitating modernization of gas supply systems. Using the constant gas supply method, it has been established that partial methane substitution allows for reducing CO₂ emissions by 20-50% without a substantial increase in NO_x and without changing the dew point of the flue gases. The proposed strategy creates a foundation for forming flexible, energy-efficient, and environmentally balanced boiler operating modes without the need for a complete reconstruction of fuel systems.