Plasma-assisted ignition and combustion of methane-air mixtures using dielectric barrier discharge

Summary form only given. More than 80% of the energy we consumed comes from the combustion of fossil fuels. Non-equilibrium plasma generated by dielectric barrier discharge (DBD) can play a key role in hydrocarbon combustion reactions. In this paper, we investigate the characteristics of dielectric barrier discharge with co axial electrodes structure driven by repetitive microsecond pulse (rise time 10 μs, PRF 6 kHz, pulse duration 45 μs, amplitude voltage 15-20 kV) or sinusoidal (20 kHz, amplitude voltage 15-30 kV) power supply, respectively. A mechelle spectrometer (Mechelle 5000, Andor) is used to capture the plasma spectra. The results show that the discharge plasmas produce abundant active components such as CH (λ=392.5, 430.1, 438.7, 440.9 nm), C₂ (λ=473.6, 516.2, 526.5, 563.3, 609.9, 711.5, 90 9.5 nm), OH (A²Σ→X²Π0-0, λ=309.0 nm), and O (3s³S⁰→3p ⁵P, λ=777.5 nm) atoms in the excited level. Temperature of the active particles is calculated by LIFBASE software. With the increasing of applied voltage and electric field, the number and average energy of the high-energy electrons increased, leading to more free particles which are in the excited state, and finally the emission spectrum intensity is enhanced. Under the same experimental conditions except for generation by different waveform of the power supply, methane-air premixed fuel gas can be ignited by sinusoidal power supply. This compared shows that the temperature of plasma driven by sinusoid al waveform is higher than that driven by microsecond pulse waveform. In this experiments it is proven that the active particles generated by the discharge plasma can accelerate the chemical reaction rate and the burning speed while reduce the ignition delay.