Experimental Investigation Of Plasma Jet Assisted Combustion Of Low BTU Fuels

Plasma-assisted combustion is a new kind of high-efficient and clean combustion,and it is the great significance to solve the pollution of energy and steel industry and to ensure the sustainable development of economy.It can not only save energy,but also effectively reduce the emission of pollutants when low-BTU gas fuels are utilized efficiently.In this paper,discharge properties,emission spectrum,combustion-supporting properties and cold flow field of plasma jet were studied experimentally with different discharge feedstock,in order to analysis the strengthening mechanism of plasma jet assisted low-BTU gas fuels.The main contents are as following:(1)Using air,nitrogen and nitrogen hydrogen mixture as the discharge feedstock of the plasma jet generator respectively,the discharge parameters and the spectrum of active particles were studied under the condition of different flow rate and different hydrogen content.The results indicated that,discharge power and emission spectrum were different when using different discharge feedstock and different flow settings,and the high flow rate not only caused the discharge waveform to shock,but also increased the average discharge power.(2)Air and nitrogen were used as the discharge feedstock respectively to investigate blow-off limits under different discharge feedstock flow rate.Subsequently the blow-off limits were investigated under the condition of different hydrogen content and different carbon monoxide using air as the discharge feedstock.The result further validated that the mechanism of plasma assisted combustion was mainly the acceleration of chemical reactions.The result also indicated that,there was an optimum flow rate,and excessive flow rate would even inhibit combustion.(3)The flow field,the axial velocity,the radial velocity and the tangential velocity were investigated in order to analysis the cold flow field before and after the plasma jet generator discharge combining the advantages of the PIV(Particle Image Velocimetry)and the LDV(Laser Doppler Velocimetry).The result indicated that,the mechanism of plasma jet assisted combustion was not limited to the acceleration of chemical reactions,but also the change of the flow field.