Mechanism Investigation On The Natire Gas Diffusion Combustion With The Addition Of CO₂

As a kind of clean, environmental, efficient energy, the nature gas has been givengreat attention by the world. Compared with the shortage of the coal and petroleum,the high quantity of its storage and mining relieves the energy shortage of the world.Recently, it has been found large quantity of nature gas with a content of CO2in themining of the later period in many gas field. Research found that dilution of the CO2emerged in the nature gas can reduce the NO production. Thus, the mechanisminvestigation on the effect of CO2dilution and its reduction to the NO productionhas got more and more attention by the researchers all over the world.The experimental and numerical investigation of the flame structure and thepollution production of the nature gas with CO2have been studied first. based onthe research status review. And then depending on their study method and lack, theresearch and experiment program of this study has been proposed.Considering the experiment of this study, a laminar diffusion flame burner wasdesigned. On the PLIF measure experimental platform, the effect of different ratioof CO2dilution in the fuel and stoichiometric ratio on the concentration of OH, CHactive radicals were investigated. It was found that when the ratio of CO2dilutionranged from0to0.4, the radiation intensity of the OH decreased and the position ofthe OH moved to the nozzle of the burner. The radiation area of the CH alsodecreased with the increase of the CO2dilution and the flame got narrow. When theCO2dilution exceeds20%of the fuel, there was nearly no CH in the top of theflame and the CH only appeared in the flame front. When the stoichiometric ratioranged from0.7to1.2, the radiation intensity of OH increased but there was noobvious change to the position of OH. And nearly no change of the radiationintensity and position of CH were found.At the same time, a PIV measure experimental platform was designed. The effectof different ratio of CO2dilution in the fuel and stoichiometric ratio on the velocityof the laminar diffusion flame was investigated. It was found that the velocity of theflame decreased when the ratio of CO2dilution increased. The velocity alsodecreased with the increase of the stoichiometric ratio, but the changes were veryfew.