Three-dimensional Simulation of Wet Combustion of Hydrogen-methane Mixture in the Annular Combustion Chamber of a Microturbine

This study presents a three-dimensional simulation of wet combustion in the annular combustion chamber of a C۳۰ microturbine using a hydrogen-methane fuel mixture. The research aims to minimize exhaust emissions, including nitrogen oxides (NOx) and carbon monoxide (CO), and reduce fuel consumption. A partially premixed combustion model has been utilized to accurately simulate the combustion process within the chamber. The impact of steam addition (wet combustion) is also analyzed. The simulation employs the k-ε Realizable turbulence model and probability density function (PDF) for chemical reactions. The fuel mixture is adjusted by adding hydrogen in increments of ۱۰%, resulting in a final composition of ۴۰% hydrogen and ۶۰% methane. With hydrogen’s high heating value, the chamber temperature reaches ۲۳۷۶ K, significantly increasing NOx and CO emissions. To control the temperature and maintain turbine operating conditions, the fuel mass flow rate is reduced by ۳۵%, ensuring a consistent turbine inlet temperature. At this temperature, CO and CO۲ emissions decrease by ۱۶% and ۶۱%, respectively, while NOx emissions increase due to hydrogen’s flame characteristics. The introduction of humidity levels of ۲.۵%, ۵%, ۷.۵%, and ۱۰% in the inlet air reduces NOx emissions by ۶۸% in the case where the fuel mixture contains ۱۰% hydrogen, with this reduction occurring at ۱۰% humidity. Additionally, a ۴۸% reduction in CO emissions was observed when the fuel mixture contained ۴۰% hydrogen, and this reduction also occurred at ۱۰% humidity. Wet combustion also enhances temperature uniformity in the chamber. These findings highlight the potential of hydrogen-methane mixtures with wet combustion to enable low-emission, efficient microturbines, supporting sustainable energy goals.

کلیدواژه ها:

Turbulence ، Chemical reactions ، Premixed ، Nitrogen oxides ، Emission