Study On Premixed Laminar Combustion Characteristics Of Hydrous-ABE

As a clean biomass fuel,the bio-butanol has been concerned and studied by more and more scholars.However,in the process of actual production,the bio-butanol has to be separated and purified in the extraction process from the fermentation liquid,which requires additional production energy consumption and limits the wider use of bio-butanol.In order to save the cost,it is necessary to study the combustion characteristics of the intermediate product ABE?acetone,butanol and ethanol volume ratio is 3:6:1?or the hydrous-ABE fuel in the engine.Compared with ABE fuel,the requirement for the production process of hydrous-ABE fuel is greatly reduced,so the application of the hydrous-ABE fuel can greatly save the production cost while ensuring the dynamic performance.As an intermediate product of butanol fermentation,the hydrous-ABE fuel can be used as a cleaner fuel for lower production cost,although the hydrous-ABE fuel has been paid attention by researchers,but the research on the laminar combustion characteristics is still scarce.Based on the preliminary study on the laminar combustion characteristics of ABE fuel,the laminar combustion characteristics of the hydrous-ABE fuel were studied in this paper through experiments and simulation methods.The experimental results show that the laminar combustion velocity of the hydrous-ABE fuel decreases with the increase of water content,and increases at first and then decreases with the increase of equivalent ratio.The velocity increases with the increase of temperature,yet the increase of the pressure slows down the combustion velocity.Markstain length gradually increases with the increase of water content,in particular,and the increase of water content has few effects on the Markstain length at the equivalent ratio of 1.4.In addition,the Markstain length gets decreased with the increase of the equivalent ratio,and its variation is not obvious as the temperature increases,while it gradually decreases with the increase of pressure;By comparing the laminar combustion velocity obtained by simulation and experiment,it suggests that the simulation results are well predicted to the test data,the chemical kinetics of the laminar flame of the hydrous-ABE was further analyzed.In the hydrous-ABE laminar flame,the influence of water content and initial condition on component concentration and flame temperature is significant.The effects of different elementary reactions on laminar combustion velocity vary with the change of water content and initial condition,but the most important reaction is reaction R1,which generates radicals O and OH,and it promotes the laminar combustion,the reaction,which exerts most negative effects on the laminar combustion velocity,is reaction R8 that consumes radicals H and OH.In the laminar flame of hydrous-ABE,the change of laminar combustion velocity is significantly related to that of molar concentration of O,H and OH,and the influence of water content and initial conditions on the molar concentration of O,H and OH is consistent with that on laminar combustion velocity.In addition,as the axial distance increases,the concentrations of HO₂,CH₃,O,H,and OH increase sequentially.By comparing with the corresponding flame temperatures,it suggests that the generation and consumption of HO₂ and CH₃ occur at low temperatures,O,H,and OH appear in the reaction when the flame temperatures is more than 1200 K.