Spatiotemporally resolved characteristics of arc plasma in non-thermal multi-arc generator at atmospheric pressure

Y J Huang,Q F Lin

doi:10.1063/5.0075905

Abstract

The spatiotemporally resolved characteristics of arc plasma in a non-thermal multi-arc generator with three high-voltage electrodes and a common grounded one were investigated by means of arc current signal, discharge image signal, and image analysis. Experimental results show that the spatial distribution of multi-arc plasma can be adjusted by the gas flow rate, and multi-arc plasma tends to distribute in the center of the arc chamber with the decrease in the gas flow rate. Once the confluence of three independent arc columns occurs, a common arc root will be shared by three arcs. The common arc-root attachment varies between constricted state and diffuse state, and the variation duration was in a cycle of about 1 ms, which is associated with beat vibration caused by the small deviation among the frequencies of three arc currents. This phenomenon suggests that the size of the arc root attachment can be adjusted by means of the frequency of the driving power supply.

Highlights

IntroductionOwing to the special features between thermal plasma and cold plasma, warm plasma was characterized by a moderate gas temperature (usually 1500–4000 K) and enough reactive species. warm plasma has great potential in various applications, such as hydrogen production from ammonia decomposition, enhancement of ignition and combustion, synthesis gas from CH4–CO2 reforming, and pollutant degradation. Non-thermal arc plasma (NTAP) was a fundamental production method of warm plasma
Owing to the special features between thermal plasma and cold plasma, warm plasma was characterized by a moderate gas temperature and enough reactive species.1,2 warm plasma has great potential in various applications, such as hydrogen production from ammonia decomposition,3 enhancement of ignition and combustion,4–7 synthesis gas from CH4–CO2 reforming, and pollutant degradation.8–10 Non-thermal arc plasma (NTAP) was a fundamental production method of warm plasma
Gangoli et al.1 have developed a NTAP generator driven by an axial magnetic field

Summary

Introduction

Owing to the special features between thermal plasma and cold plasma, warm plasma was characterized by a moderate gas temperature (usually 1500–4000 K) and enough reactive species. warm plasma has great potential in various applications, such as hydrogen production from ammonia decomposition, enhancement of ignition and combustion, synthesis gas from CH4–CO2 reforming, and pollutant degradation. Non-thermal arc plasma (NTAP) was a fundamental production method of warm plasma. Various types of large-scale NTAP generators have been developed, such as magnetic-driving NTAP, non-thermal multiarc plasma, and glow-type gliding arc discharge in NTAP.. Compared with the single arc in the magnetic-driving arc plasma, producing multiple arcs at the same time was an alternative method for producing large-scale NTAP. By optimizing the spatial distribution of six electrodes and electrical connection sequences between six electrodes and three power supplies, a large-size high-temperature plasma can be obtained in the center of the discharge zone. Zhu et al. have developed a NTAP generator, which can produce NTAP with the features of high voltage and low current to avoid the occurrence of a short-cutting event. NTAP with large scale has been produced in a multi-arc generator, the features for the spatiotemporal distribution of the arc column and the arc root have not been revealed

Methods

Results

Conclusion