Optical and electrical analysis of multi-electrode cylindrical dielectric barrier discharge (DBD) plasma reactor

Abstract

Aiming to decrease the dielectric barrier discharge (DBD) capacitive current, a new type of multi-electrode cylindrical DBD plasma reactor was proposed in this work. Due to the novel multi-electrode design, the discharge current peak value of the newly designed plasma reactor decreased by 66.24%, from 16.26 mA for the traditional device to 5.49 mA. Besides, the number of the micro-discharges was found almost 2 times higher than that of the traditional device, indicating the generating of more discharge channels (from 37 to 89). The enhanced corona discharge formed at the electrode edges caused by fringe effect was considered as the main reason. The opti-electrical analysis was performed using multi-electrode plasma reactors with different electrode configurations. The changes of optical emission efficiency (Ieff), equivalent capacitance of dielectric layer (Cd) and the discharge gap (Cg) were investigated under different applied voltage, discharge length, interval between adjacent outer electrodes and electrode width. The experimental results indicated the efficient discharge length l and fringe effect were responsible for the variations of Ieff, Cd and Cg. Higher applied voltage resulted in a higher Ieff, but higher current at the same time. Besides, Cd gradually increased along with the increased applied voltage while Cg presented the decreased trend. Ieff increased along with the enhanced fringe effect caused by the shorter electrode width and smaller interval between adjacent outer electrodes, while decreased with the increased discharge length. Cd and Cg decreased with increased interval between outer electrodes, but increased with the enhanced discharge length and electrode width. The voltage distribution analysis indicated that the change of Ieff was mainly due to the change of the voltage across the gas gap Vg. This work can give a deeper and further understanding on the discharge characteristics of the proposed multi-electrode plasma reactor.