Experimental and chemical kinetic analysis of laminar burning velocity of ammonia/dimethyl ether/air mixture at elevated temperature and pressure using a reduced-updated skeletal reaction model

Abstract

Recently, ammonia has garnered significant interest from several organizations as a potential environmentally friendly fuel, primarily due to its superior volumetric energy density and convenient storage, handling, and transportation characteristics. However, the practical application of ammonia still needs to be significantly improved due to its lower laminar burning velocity, narrow flammability limit, and higher NOx production. Ignition enhancer fuels like methane, hydrogen, and Dimethyl ether (DME) can be added to ammonia as ignition enhancers to curb its slower reaction kinetics and improve its flame propagation characteristics. In the present work, the heated diverging channel technique is used for the experimental measurement of laminar burning velocity for NH₃/DME/air premixed flames for premixed temperatures and pressures of 300–700 K and 1–5 atm. Furthermore, a reduced– updated (RU) skeletal reaction model is proposed based on the available literature. The proposed RU model, along with available reaction models, are validated for the above-stated experimental measurement conditions. Also, chemical kinetic analysis is performed considering the RU model to understand the laminar burning velocity reaction kinetics using the sensitivity, flame structure, and rate of production analysis.