Study On The Characteristics Of Soot From Swirling Combustion Of Alternative Fuels Of Gasoline Model Blended With 2,5-Dimethylfuran

To alleviate the severe stress of energy shortage and environmental pollution,it is the urgent problem to find new alternative fuels at present.2,5-dimethylfuran(DMF)that was the one of the typical furan biofuels has been widely concerned because of its better combustion properties.For a better application,it is necessary to conduct the combustion diagnosis for the purpose of investigating the properties of combustion and pollution emissions.Soot particles are mainly pollution of fossil fuel combustion,which threaten the human health gravely.It is favourable for understanding the generation mechanism of soot particles to study the characteristics of soot under the different test conditions,which provides the theoretical guidance to control the soot emissions.Therefore,this paper mainly added DMF to n-heptane and iso-octane for blending diffusion combustion with swirling and non-swirling.The effects of swirling combustion on the soot characteristics under different conditions were investigated by using the High Resolution Transmission Electron Microscopy(HRTEM),X-ray diffraction(XRD)and thermogravimetric analysis(TGA)Firstly,the numerical simulations of swirling and non-swirling combustors were conducted to study the flow and mixture situations of fuel and air in the region of combustion.The results demonstrated that swirling could intensify the mixture of fuel and air in comparison to non-swirling,which was conducive to combustion.Secondly,in order to study the effects of swirling and collection time on soot characteristics under different fuel conditions,the experiment of swirling and non-swirling combustion with adding DMF to n-heptane was performed depending on the normal diffusion combustion system.The results showed that the average soot yield increased with the increase of DMF.The soot particles formed from the flames of adding 50%DMF presented the representative core-shell nanostructures.Compared with the non-swirling,swirling could enhance the mixture of air and fuel.Thus the yields of soot from the flames with 20% and 50% DMF addition and soot particles were higher maturity and lower oxidation reactivity.The effect of collection time on soot from the flames of adding 50%DMF was more obvious,which could promote the increase of graphitization degree of soot particles.Thirdly,for studying the effects of swirling and collection time on nascent soot characteristics under different fuel conditions,the experiment of swirling and non-swirling combustion with adding DMF to n-heptane was conducted through utilizing the inverse diffusion combustion system.The results demonstrated that the yield of soot from pure n-heptane flame was few extremely and the nanostructures of soot were amorphous nature.With the addition of DMF,the average soot yield increased and the fringe arrangement of soot was more organized.Soot generated from swirling flames has been oxidized in the inception period,leading to the soot with lower oxidation reactivity being collected,and such effect of swirling was unconspicuous in the conditions of pure n-heptane.The effect of collection time on soot characteristics was negligible in all of conditions.Finally,the experiment of swirling and non-swirling combustion with adding DMF to iso-octane was carried out.The results revealed that the effect of swirling on nascent soot from DMF/iso-octane flames was similar to that of DMF/n-heptane.In addition,the structures of iso-octane and n-heptane flames were different and the nascent soot nanostructures from iso-octane flames were more well-organized.