Effect of Hydrogen Addition on the Combustion and Emission Characteristics of Methane Under Gas Turbine Relevant Operating Condition

The influence of hydrogen addition (0-100%) on combustion and emission characteristics (NO and CO emission characteristics) of laminar-premixed methane flame under gas turbine relevant operating conditions was numerically studied. The PREMIX code of ANSYS CHEMKIN-PRO and the GRI-Mech 3.0 were utilized. Based on the research on the F-class gas turbine operating condition ( T =723 K, P =16.5 atm), it can be seen that the influence of hydrogenation on the methane combustion and emission characteristics of the gas turbine operating condition can be studied by numerical simulation under normal temperature and pressure. First, the variation of LBV (laminar combustion velocity) and AFT (adiabatic flame temperature) with Φ (equivalence ratio) from 0.6 to 1.4 under different hydrogen contents was investigated at normal temperature and pressure. Furthermore, the effect of hydrogen addition on the molar fraction of NO and CO in methane was studied under lean combustion conditions ( Φ =0.6,0.8). In addition, the production rates and sensitivity coefficients of NO and CO in methane with different hydrogen contents were also analyzed. The results showed that the LBV and AFT of methane increased with the addition of hydrogen. In addition, the mole fraction of H, O and OH and combustion temperature are closely related to LBV. With the increase of hydrogen content in methane, the mole fraction of H, O and OH and combustion temperature increase. Due to the higher flame temperature, the addition of hydrogen to the methane/air mixture can promote the increase of NO concentration and inhibit the formation of CO. The main reaction to promote the formation of NO is R208 NNH+O<=>NH+NO. The main CO consumption reaction in the methane-hydrogen-air flame is R99 OH+CO<=>H+CO 2 . For the hydrogen-methane mixture, reducing the equivalence ratio (from 1.2 to 0.6) can significantly reduce NO emission, and the NO emission during hydrogen combustion can be reduced by as much as 83%