Speaker
Description
Hydrogen role in energy systems has become a central focus of global interest due to its potential as a zero-carbon fuel. Hydrogen provides a transformative alternative to hydrocarbons, exhibiting unique combustion properties. However, its high reactivity often leads to combustion instabilities, e.g., flame flashback or blowout, which increase the risk of combustor failure. Therefore, to minimize these challenges, hydrocarbons fuels such as methane, propane, and ammonia are add to the hydrogen-air mixtures, aiming to influence its laminar burning velocity (LBV), a critical property in all fuel types that significantly affects the combustion process. In this work, we aim to investigate the effects of these gaseous additives on the behavior of the laminar burning velocity and the formation of nitrogen oxide (NO_X) emissions. An updated detailed and reduced reaction mechanism are utilized to ensure accurate representation of chemical kinetics for the selected fuels. The simulations are performed using a one-dimensional freely-propagating adiabatic premixed flame (FPPF) model in Cantera, incorporating both kinetic and thermodynamic modeling. The results are validated against experimental data. The study examines a range of operating conditions, including variations in inlet pressure, temperature, and H₂/CH₄, H₂/C₃H₈, and H₂/NH₃ ratios. We have successfully predicted the hydrogen behavior with each fuel selected under the conditions considered for the analysis. The results reveal that among the fuel mixtures studied, the H₂/C₃H₈ blend exhibits the lowest LBV at high equivalence ratios, reaching 45 cm/s at ϕ = 3.8. Similarly, the flame temperature for this mixture follows the same trend, with a minimum value of 1485 K at ϕ = 3.8. NO_X emissions decrease with increasing equivalence ratio, with NO concentrations reaching a minimum of 0.35 ppm at ϕ = 3.8.
