Optimization Strategies of Gliding Arc Plasma-Based Ammonia Cracker towards On-Board Applications

Ammonia has emerged as a viable hydrogen energy carrier owing to its superior hydrogen density, mature industrial utilization. However, ammonia faces critical challenges including inadequate ignition characteristics and sluggish combustion kinetics, necessitating supplementary high-reactivity fuels for optimizing combustion. Onboard ammonia cracking technology resolves this problem through on-demand hydrogen in-time production. Among existing decomposition methods, gliding arc plasma (GAP) demonstrates exceptional promise for on-board crackers given its decent hydrogen conversion rate and transient response capability. Prevailing research predominantly employs experimental methodologies wherein macroscopic parameters inadequately proxy microscopic electric field characteristics, thereby impeding mechanistic insight. This study establishes a quasi-1D numerical model to interrogate how electric field parameters modulate ammonia-to-hydrogen conversion yield and system energy efficiency in GAP reactors. Besides, the regulatory influences of inlet pressure and gas density inside the reactor are also studied. The results indicate that enhanced reduced electric field strength and electron density substantially elevate hydrogen yield, yet exhibit non-monotonic dependence on energy efficiency—beyond critical thresholds, efficiency declines precipitously. Conversely, increased gas density marginally reduces hydrogen yield but significantly amplifies energy efficiency through optimized reaction kinetics. Besides, appropriately increasing the gas density by raising the intake pressure can effectively optimize the energy efficiency of hydrogen production, and the balance between hydrogen conversion rate and energy efficiency can be achieved by combining with the optimization of electric field parameters. This study reveals the synergistic regulation mechanism of electric field parameters and gas density on hydrogen production performance, providing a key theoretical basis for the optimization of on-board GAP reactors.