Comparative numerical simulation of combustion flows in a dual-fuel-combustor

Combustion flows with different fuels as heptane and pyrolysis gas in a dual-fuel-combustor of gas turbine were simulated by a CFD(computational fluid dynamics) method.The RNG(renormalization group) k-ε turbulence model,single chemistry reaction system,infinite-rate reaction velocity,discrete phase modeling for liquid fuel,upwind discretization scheme and the SIMPLE algorithm were applied.Some performances of combustor such as: combustion efficiency,temperature uniformity at outlet,temperature distribution of walls,distribution of air mass flow and the first air excess coefficient,were also analyzed.Some results show that: 1) the distribution of mass flow rate is consistent with different fuels,2) there is a 1% higher combustion efficiency and lower temperature uniformity at outlet with pyrolysis gas than that of oil fuel,3) the average temperature at outlet with pyrolysis gas is 20～40K lower than that of oil fuel with the same chemical enthalpy injected in the combustor,and 4) the first air excess coefficient α of pyrolysis gas is higher than that of oil fuel.