Study On Laminar-premixed Combustion Characteristics Of ABE

Butanol is an ideal alternative fuel for engines,which could effectively alleviate fossil fuel crisis and restrain the environmental pollution.Nevertheless,to obtain more bio-butanol,it should separate and purify fermentation liquid using special instruments,which increased manufacturing costs and energy consumption of bio-butanol and severely restricted the promotion of bio-butanol fuel in engines.Thus,this study proposed that taking ABE(volume ratio of acetone,butanol,ethanol is 3 to 6 to 1),intermediate product of fermentation,as engine fuels power cars.So far,studies about ABE fuel mainly focused on the engine test,however,its fundamental combustion characteristics are still unknown.This study carried out the experience and analog computation between ABE fuel and its single components by spherical spreading flames experience and CHEMKIN dynamics simulation to emphatically analysis the effects of initial conditions(temperature,pressure and equivalence ratio)on laminar combustion characteristic of ABE-air mixtures.The results showed that laminar burning velocity of ABE fuel and its single components all increase at first then decrease with the equivalence ratio increasing.The laminar burning velocity(ethanol> butanol> ABE> acetone)appears the maximum value when equivalence ratio reached 1.1,and the laminar burning velocity of ABE fuel is the closest butanol.The adiabatic flame temperature trend of four kinds of fuel shows that the laminar burning velocity can be controlled by adiabatic flame temperature and higher hydrocarbon ratio fuels showed a better control.Molecular structure and the number of carbon atoms comprehensively determine the Markstein length(acetone> butanol> ABE> ethanol),that showed the order of flame stability.Regarding ABE fuel,laminar burning velocity rise with the increase of the initial temperature which lead adiabatic flame temperature ascending.On the one hand,the influence of the initial temperature on laminar burning velocity is just a little.On the other hand,the increase of the initial temperature can also result the augment of adiabatic flame temperature.The laminar burning velocity decreases within the increase of the initial press and its impacted extent gradually decreases as the pressure rises.The results demonstrated that Markstein length decreased with the increase of the initial temperature which showed less impact on flame instability.And Markstein length decrease with the increase of the initial pressure.That is to say,the increase of the pressure makes the flame become more unstable.Markstein length tends to be a constant value as the pressure constantly increases.Meanwhile,the paper simulated exponential formulae of ABE laminar burning velocity,which fitted the experimental dat.