The effect of the formation of key components on the laminar combustion rate of ammonia/methanol mixture combustion under medium-pressure gas turbine related working conditions

Abstract

With the development of industry, environmental pollution is becoming more and more serious, and greenhouse gas emissions lead to the continuous rise of global temperature; thus, energy conservation and emission reduction are imminent. In recent years, green methanol and green ammonia, as important hydrogen carriers, have attracted wide attention because of their low carbon emission and high calorific value. However, ammonia has a slow laminar flame speed, and the addition of methanol can improve this characteristic. This has sparked interest in the study of ammonia/methanol co-combustion. This study first investigates the relationship between the methanol addition ratio, temperature, and the laminar flame speed of ammonia. Through MATLAB simulations, the study further examines the key species involved in the combustion process. The results indicate that the laminar flame speed is linearly related to the maximum concentration of (O + H + NH₂). Following this, the yield and sensitivity analyses of the three radicals (O, H, and NH₂) were performed. It was found that these three radicals have a positive correlation with both temperature and methanol content, with temperature and methanol primarily influencing the content of H radicals, which in turn affects O and NH₂. Finally, using the modified fictitious diluent gas approach, it was concluded that the chemical properties of methanol are the main factor promoting ammonia oxidation. In this study, the key components of mixed combustion of methanol and ammonia gas and the principle of methanol combustion aid were studied, aiming to enrich the database of mixed combustion of methanol and ammonia gas and provide a reference for the design of gas turbines.