Methane–Air Plasma-Assisted Ignition Excited by Nanosecond Repetitively Pulsed Discharge: Numerical Modeling and Effect of Inert Gas

Abstract

Plasma-assisted ignition and combustion are promising approaches for controlling ignition enhancement and flame stabilization. The global loosely coupled plasma-assisted combustion kinetic model has been established by combining the ZDPlasKin and ChemKin codes, which is employed to numerically investigate the effects of the inert gas-diluted methane−air nanosecond repetitively pulsed (NRP) plasma on the ignition process. The results indicate that addition of the inert gas is conducive to increasing the chemical reactive species densities in the methane−air NRP discharge plasma. The addition of inert gases affects the generation pathways of plasma species and their corresponding contribution rates. Compared with the methane−air plasma, the dilution of inert gases shows obvious effects on reducing ignition delays, and the dilution of He and Ar decreases the ignition delays by 58.0 and 84.0%, respectively. CH 3 + O 2 = CH 3 O + O and H + O 2 = O + OH are the dominant conducive reactions in the methane−air ignition chemistry. Moreover, the dilution of inert gases has considerable influences on the normalization sensitivity coefficients, especially for the reaction of H + O 2 = O + OH.

Plasma Catalysis for Hydrogen Production: A Bright Future for Decarbonization

“…Additionally, reports have shown that adding an inert gas such as Ar increases the electron energy and enhances the electric field . This increases electron impact reaction with gas phase molecules and promotes plasma-phase chemistry. − There is also the potential to create metastable species, which undergo Penning ionization through impact collision and energy exchange with neutral species such as NH 3 . , …”

“… 296 This increases electron impact reaction with gas phase molecules and promotes plasma-phase chemistry. 296 − 298 There is also the potential to create metastable species, which undergo Penning ionization through impact collision and energy exchange with neutral species such as NH 3 . 196 , 299 …”

Investigation on the Regulation of the Combustion Characteristics of a Propane/Air Mixture by Repetitive nSDBD Pretreatment

“…In order to overcome the problems in the lean combustion process, plasma-assisted combustion technology has been widely studied. − With the progress of plasma-assisted ignition and combustion, plasma-assisted combustion technology is expected to become a more effective combustion control method . Plasma assists combustion mainly through three pathways: (1) thermal effect; (2) activation effect; (3) transport effect.…”