NUMERICAL STUDY OF THE AMMONIA-HYDROGEN-NITROGEN COMBUSTION CHARACTERISTIC USING ANSYS FLUENT

• Main Author: Apri Utomo, Budiman
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/84811
• Institution: Institut Teknologi Bandung

The increase in use of fossil fuels has caused a notable increase in worldwide temperatures, resulting increase of 1.5 K, being reported as the highets temperature increase in human history. This phenomenon is associated with a rise in greenhouse gas emissions, specifically carbon dioxide. From this phenomena, the advancement of environmentally friendly technologies and sustainable energy sources is needed. Hydrogen is becoming a promising solution because of the plentiful availability of hydrogen and its environmentally friendly combustion. Yet, obstacles related to storing and handling hydrogen restrict its feasible application. Ammonia (NH3) is a possible option for storing energy as an alternative to hydrogen because it has a greater energy density per unit volume and requires less strict storage conditions. Although ammonia has benefits, its burning creates nitrogen oxides (NOx) which are detrimental, and it has a low level of flammability. This research examines how swirling flow, Reynolds number, equivalence ratio, and ammonia fraction affects combustion characteristics in swirl-stabilized ammonia-hydrogen-nitrogen combustion, utilizing Ansys Fluent and the k-? model in numerical analysis. The results show that emissions from ammonia-nitrogen-hydrogen combustion are greatly affected by Reynolds number, swirl number, equivalence ratio, and ammonia fraction. A higher Reynolds number results in increased NOx emissions at the burner exit. A ratio of 0.8 leads to the highest concentrations of NO and leftover ammonia in all situations. Surprisingly, the higher the ammonia fraction, the lower the NO levels in the exhaust gas. Although the swirl number doesn’t have much impact on NO and residual ammonia, it does assist in keeping the flame stable within the burner. These findings emphasize the intricate nature of ammonia combustion and the necessity of optimizing operational parameters to reduce emissions and maintain steady combustion.