Autoignition of butanol isomers/n-heptane blend fuels on a rapid compression machine in N_2/O_2/Ar mixtures  

作　　者：YANG Zheng WANG Yue YANG Xin QIAN Yong LU XingCai HUANG Zhen 

机构地区：[1]Key Laboratory for Power machinery and Engineering of M. O. E., Shanghai Jiao Tong University

出　　处：《Science China(Technological Sciences)》2014年第3期461-470,共10页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.2013CB228405)

摘　　要：Ignition delay times of butanol isomers/n-heptane mixture were measured using a rapid compression machine at compressed pressures of 15,20 and 30 bar,in the compressed temperature range of 650–830 K and equivalence ratio of 1.0.Sensitivity analysis and reaction fluxes analysis were performed using a detailed mechanism of blend fuels so as to evaluate the impact of n-heptane addition and temperature variation on the ignition and combustion process.Over the experimental conditions in this study,the blend fuels displays apparent low and high temperature reactions and a negative-temperature-coefficient(NTC)behavior.With increasing butanol isomers mole fraction in the mixtures,the ignition delay times increase.It is worth noting that the suppression to n-heptane ignition from tert-butanol is very limited.The ignition delay time of 40/60 tert-butanol/n-heptane mixture is smaller than other three kinds of blends.With the increasing of tert-butanol mole fraction,the increasing range of its ignition delay time is very large.Moreover,compressed pressure has a limited effect on the ignition of blend mixture at low temperature but certain influence at medium temperature arrange.Tert-butanol/n-heptane mixture is not sensitive to the pressure.The chemical analysis indicates that butanol isomers also present the NTC behavior because of the low temperature reactivity radicals pool produced by n-heptane.Reaction fluxes analysis shows that the n-heptane addition has little impact on the reaction path.Sensitivity analysis shows that for the pure n-butanol,2-butanol and iso-butanol fuel,H-abstraction from the?-carbon plays the dominant role in the reactions having the inhibiting effect on the low-temperature branching,while the H-abstraction from the?-carbon can promote the ignition;for tert-butanol/n-heptane mixtures,reaction R16.H2O2(+M)<=>OH+OH(+M)plays the leading role.For n-butanol/n-heptane,iso-butanol/n-heptane mixtures,the major promoting reactions include some H-abstraction from n-heptane and OH branching reactions,the in

关 键 词：butanol isomers blend fuels ignition delay rapid compression machine chemical kinetics 

分 类 号：TQ51[化学工程]