Numerical Simulation And Experimental Study Of Turbulent Biogas Combustion

As rapid depletion of fossil fuels and the deterioration of our environment, biomass has become a more significant source of energy in China. There is therefore a need to understand more biomass conversion process, technology and application. The purpose of this work is to study the influence of different operating parameters on biogas combustion and features of the flame.A combustor based on a Bunsen jet has been outlined in this study. This test setup has been systematically studied numerically to obtain more information about the biogas combustion. Different operating parameters, important for the combustion process, have been investigated. The parameters included the dimension of the combustor, turbulence intensity, fuel and air mass flow, and secondary air supply.The turbulent combustion of biogas in the outlined setup has been simulated using a CFD code developed at LTH. The results from the simulations show that the biogas combustion has certain similarities to the methane combustion, yet significant differences between the two types of flames exist. The combustion process is fairly sensitive to the geometrical and operational parameters. In particular, since biogas flames yield lower flame temperature, due to the fact that biogas contains CO2 and the heating value of the fuel is low, it is not straight forward to obtain stable combustion. To obtain stable combustion condition, preheated secondary air may have to be used.