Experimental Research on Dynamic Characteristics of Plasma Ignition Jet

摘要

The performance of the ignition device has an impressive impact on the working range and reliability of gas turbines. In the extreme conditions and with low pollutant emissions, gas turbines advancing higher requirements for the better performance of the ignition device. Due to its exceptional advantages, plasma ignition technology has become a research hotspot for all the scholars around the globe. The plasma ignition device ignites by the plasma jet with high- temperature and abundant active species, which has the advantages of large ignition energy, concentrated energy and strong penetration of the plasma jet. In the current research work, experimental research work is carried out on the plasma ignition using the plasma jet. The voltage and current features of plasma power supply are measured by a voltage probe and a current probe. The developed process of plasma jet generation is captured by a high-speed camera. The characteristics of plasma jet morphology and the law of the influence of the variable electrode gap (1.5 mm-3.5 mm) on the features of the plasma jet morphology are investigated. The experimental results demonstrate that during plasma ignition the discharge voltage and the current have a maximum peak-to-peak value of 11.67kV and 70A. The maximum reverse voltage and the reverse current are 2000V and 15A during the discharge and breakdown. The plasma jet produced active species along with a cone-shaped high- temperature during the air breakdown. The structure of the plasma jet can be divided into two portions, central high-temperature kernel (HTK) and peripheral halo gas (PHG) by gray processing of high-speed camera pictures. Different discharge electrode gap is leading to change the size of the plasma jet high- temperature kernel and the peripheral halo gas. If the gap of the discharge electrode is increased, then the area of the high- temperature kernel is also increased.