Study On Low Temperature Plasma Assisted Combustion Under High Pressure

Atmospheric pressure low temperature plasma is one of the important exploration hotspots in the field of plasma science research in the world.This paper deals with parameters such as discharge mode,electrode structure,discharge applied voltage and discharge frequency.Coaxial dielectric barrier discharge and plasma jet discharge were studied experimentally,and the characteristics of methane combustion based on plasma ignition were studied.The spectroscopic analysis of the plasma line was carried out by atomic emission spectrometry(AES).The electron temperature was tested by the Boltzmann method.The electron density was calculated according to the Stark broadening effect.The results show that the electron temperature does not increase with the increase of the applied voltage,and the electron density tends to be quasi-linear with the increase of the applied voltage.The discharge of the toothed electrode has a higher discharge intensity and a remarkable discharge effect;the discharge intensity of the cylindrical electrode is weak,but a large area uniformity plasma is easily formed.The atmospheric pressure discharge plasma jet was tested and analyzed by a self-designed needle-ring electrode jet structure.The effects of discharge frequency,the jet position and the peak voltage on plasma jet characteristics were analyzed by using the method of emission spectrometry-photogrammetry-electrochemical phase coupling.The results show that the plasma jet discharge of the needle-ring electrode structure is similar to glow discharge;the jet length first increases linearly with the increase of the applied voltage;the jet length also increases with the discharge frequency.It will grow with it.Plasma ignition was initially explored with constant volume combustion chamber as reaction chamber carrier.The initial pressure was 0.1Mpa,the initial temperature was 320 K and 420 K,and the equivalent ratio range was 0.55-1.0.The lean burn limit,flame expansion characteristics,laminar burning velocity and Maxstein length were analyzed,and the effects of premixing temperature,equivalence ratio and ignition mode on the combustion characteristics of methane were analyzed.The results show that with the increase of temperature and equivalence ratio,the development of flame can be promoted to improve the fuel burning speed;plasma ignition has higher lean burning ability,stable flame combustion,and more significant combustion speed and efficiency.