Simulation study of a pulsed DBD with an electrode containing charge injector parts

Abstract

By using a multispecies fluid model, the tunability and controllability of plasma parameters such as distributions of electron density, electron energy, ion density, and electric field in a microdielectric barrier discharge (DBD) with a charge injector electrode and driven by negatively polarized nanosecond pulsed voltage superimposed on a positive DC bias voltage are investigated. To this end, the effects of changing features of pulsed voltage like pulse rise time (10–20 ns), pulse peak width (10–15 ns), and pulse fall time (20–30 ns) on characteristics of argon plasma formed inside the reactor are studied. The results show that with the increase in pulse width and pulse rise time, the density of electron and ion increases, while fall time change does not significantly affect the plasma parameters. Generally, the results of this study explicitly prove the possibility of controlling plasma formed inside DBD reactors driven by negative pulse voltage combined with a positive DC voltage, which is very important in waste gas conversion applications.

The Effects of Pulse Shape on the Selectivity and Production Rate in Non-oxidative Coupling of Methane by a Micro-DBD Reactor

“…With comparing the distribution of electron and ion, it is found out that ion distribution peak occurs close to cone tip while for the electron it appears far away → → from the electrode tip, nearly in the centre of discharge gap. In our previous work on argon plasma for this structure [35], we showed that, during each repetition period, both electron and ion density distribution peaks perform a reciprocating motion between the cone tip and the dielectric surface. The same type of reciprocating motion for peak densities of electron and ion has also been seen here for CH 4 plasma.…”

“…It consists of two electrodes (grounded and powered) and a dielectric barrier layer with a dielectric constant of 3.0 that covers the upper electrode (grounded electrode). The bottom electrode (powered) is engraved to a periodic cone-shape sharp array, establishing charge injection phenomena [35]. The dielectric layer has a thickness of 0.5 mm and the distance between the tip of cones and surface of the dielectric layer is 0.5 mm.…”

“…The upper electrode was grounded while the bottom electrode is powered by a voltage waveform combined of a repetitive negative nanosecond pulses and a positive dc bias. In our previous work we showed how this combination of negative pulse and positive dc can lead to higher efficiency and can be used to control the process in plasma gas conversion applications [35]. The pulses is designed with 3 index labels, corresponding to pulse rise time ( t r ), pulse peak width ( t p ) and pulse fall time ( t f ) in nanoseconds, respectively.…”

Nonoxidative methane coupling in a micro‐DBD with enhanced secondary electron emission

“…[15][16][17] Recently, we have shown theoretically and computationally that dielectric barrier discharges with charge injection points have further practical benefits. [18,19] Following that, in this experimental study, we explore methane conversion in an AC-driven charge injector DBD and compare the results to the usual flat electrode DBD plasma. The sharp points on the electrodes of this specific DBD produce a high-rate secondary electron emission due to the high strength of the local electric field, which might eventually boost methane activation and energy efficiency of the process.…”

Study of plasma parameters and gas heating in the voltage range of nondischarge to full‐discharge in a methane‐fed dielectric barrier discharge

“…The use of nonthermal plasma technologies is an alternative route to tackle the barriers in $<math altimg="urn:x-wiley:16128850:media:ppap202200086:ppap202200086-math-0003" wiley:location="equation/ppap202200086-math-0003.png" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mrow><msub><mi>CH</mi><mn>4</mn></msub></mrow></mrow></math>$ activation and conversion; as such plasma technology has recently generated increased interest for gas processing [ 5 ] . Among many procedures and sources to generate nonthermal plasmas, dielectric barrier discharge (DBD) in comparison to the other systems is useful because of considerably high specific power density, low gas consumption, and strong potential for upscaling [ 6 ] . DBDs can operate at atmospheric pressure, which is most suitable for practical applications [ 7 ] .…”