Effect of plasma discharges on nitric oxide emissions in a premixed flame

A convenient way to reduce pollutant emissions or fuel consumption in industrial combustion systems is to burn in lean-premixed mode. A central pin electrode extending from the swirler to the combustion chamber inlet serves as the cathode. The anode is a circular loop with a diameter of 25 mm. It is made of a stainless steel wire with a diameter of 2 mm. This electrode is connected to the high voltage pulser through the burner ground plate with ceramic insulation. With this electrode arrangement, NRP discharge filaments are generated between the central pin electrode and the loop electrode in a disk-shaped planar area at the burner outlet. All measurements were made with the flame present. Voltage and current signals were first synchronized and then multiplied and integrated to obtain the energy deposited per pulse. The average power of the plasma was determined by multiplying the energy deposited per pulse by the repetition frequency of the discharge.