Parameter simulation study of ammonia and methane co-combustion in a gas-fired boiler
Yi, Qingyu (2026)
Kandidaatintyö
2026
School of Energy Systems, Energiatekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2026051243440
https://urn.fi/URN:NBN:fi-fe2026051243440
Tiivistelmä
With the reduction carbon become increasingly important in boiler and industrial heating systems. Ammonia and methane co-combustion provide a change which can reduce the carbon emissions in recent boiler and heating systems. When ammonia combust in air, it does not directly produce the carbon dioxide. Also, it has advantages in transporting and storing. While ammonia still has some drawbacks, for illustration, low reactivity, weak ignition combustion and will produce NO pollutants. So, these drawbacks which make ammonia combust in boiler alone has some problems. In this study, methane is chosen as a mixed fuel with ammonia which can improve flame stability while reducing the carbon content of the mixed fuel.
In this study, ANSYS Fluent is used for a numerical model of ammonia–methane co-combustion in a gas-fired boiler was developed. The boiler was designed based on a steam generation capacity of 2 t/h and a thermal efficiency of 0.92. Also, three ammonia blending ratios are named in 0.3, 0.5, and 0.7 which were investigated under an excess air coefficient of 1.1.
In the numerical setup. The standard k-ε model was used to describe turbulent flow. The Species Transport Model was applied for combustion and species distribution, and the DO radiation model was used to account for radiative heat transfer in the furnace.
In different ratio simulation this study focusses on the temperature field, velocity distribution, and CO₂, CO and NO distributions these five parts. The findings demonstrate that by lowering the fuel's methane portion, raising the ammonia blending ratio lowers CO₂ emissions. However, fuel-air mixing, flame stability, and NO formational of which are strongly correlated with local temperature and other parameters which impacted by a larger ammonia proportion.
Overall, the results indicate that ammonia blending can reduce the carbon emission potential of gas-fired boilers, but the blending ratio needs to be selected carefully. A higher ammonia fraction is favorable for CO₂ reduction, while its influence on combustion stability and NO formation must also be considered. Therefore, the parametric study of ammonia–methane co-combustion provides a useful reference for the low-carbon retrofit and clean operation of gas-fired boilers.
In this study, ANSYS Fluent is used for a numerical model of ammonia–methane co-combustion in a gas-fired boiler was developed. The boiler was designed based on a steam generation capacity of 2 t/h and a thermal efficiency of 0.92. Also, three ammonia blending ratios are named in 0.3, 0.5, and 0.7 which were investigated under an excess air coefficient of 1.1.
In the numerical setup. The standard k-ε model was used to describe turbulent flow. The Species Transport Model was applied for combustion and species distribution, and the DO radiation model was used to account for radiative heat transfer in the furnace.
In different ratio simulation this study focusses on the temperature field, velocity distribution, and CO₂, CO and NO distributions these five parts. The findings demonstrate that by lowering the fuel's methane portion, raising the ammonia blending ratio lowers CO₂ emissions. However, fuel-air mixing, flame stability, and NO formational of which are strongly correlated with local temperature and other parameters which impacted by a larger ammonia proportion.
Overall, the results indicate that ammonia blending can reduce the carbon emission potential of gas-fired boilers, but the blending ratio needs to be selected carefully. A higher ammonia fraction is favorable for CO₂ reduction, while its influence on combustion stability and NO formation must also be considered. Therefore, the parametric study of ammonia–methane co-combustion provides a useful reference for the low-carbon retrofit and clean operation of gas-fired boilers.