Application of Large-Eddy Simulation and the Multi-Scalar Flamelet Approach to a Methane-Hydrogen Mixed-Combustion-Type Industrial Gas-Turbine Combustor

In pursuit of a reduction in environmental loading, gas turbines equipped with lean premixed combustor technology that use a hydrogen-enriched fuel instead of pure methane have entered practical service. An accurate numerical simulation method is therefore needed to reduce product-development costs to a minimum. We performed a numerical analysis of an industrial combustor with a mixed methane-hydrogen fuel by large-eddy simulation and extending the 2-scalar flamelet approach to a multi-scalar one. The calculation object was the combustor of an L30A-DLE gas-turbine. Two calculations were conducted with different fuel compositions at the supplemental burner. In the first simulation, the inflow gas was composed of methane and air, whereas in the second simulation, the inflow gas was composed of methane, air, and hydrogen. The inlet boundary conditions were set so that both cases have the same adiabatic flame temperature at the outlet. The temperature distributions throughout the combustor were approximately equal in both cases. This study therefore suggests that equivalent performance can be obtained by setting the inflow condition at the supplemental burner so that the outlet adiabatic temperatures are equal for both monofuel combustion and mixed combustion.