汽油/丁醇燃料燃烧动力学简化机理的构建和验证

Development and validation of reduced combustion mechanism for gasoline/butanol blends

采用基于误差传递的直接关系图法和敏感性分析方法简化含有7714个基元反应和1765种组分的汽油/丁醇混合燃料详细机理,构建一个含有425个基元反应和96种组分的汽油/丁醇混合燃料的简化动力学机理。该简化机理含有正丁醇、异丁醇、叔丁醇和仲丁醇,以正庚烷/异辛烷/甲苯混合物作为汽油模型燃料。将简化机理预测的着火延迟、组分浓度和层流火焰速度与详细机理的预测值和实验数据进行比较,验证结果较好。最后,将该简化机理耦合到三维计算流体力学软件CONVERGE中,模拟汽油/丁醇混合燃料在发动机的燃烧过程。结果表明:构建的汽油/丁醇简化机动力学理可很好地捕捉火花点火式发动机的缸内燃烧过程。

A reduced combustion mechanism of gasoline/butanol blends containing 425 elementary reactions and 96 species was developed using direct relation graph with error propagation and sensitivity analysis,based on a detailed mechanism of gasoline/butanol containing 7714 elementary reactions and 1765species.In this reduced mechanism,i-butanol,n-butanol,t-butanol and s-butanol sub-mechanisms are included,and the n-heptane/iso-octane/toluene mixtures are used as the gasoline model fuel.The ignition delay times,species concentration profiles and laminar flame speeds predicted by the reduced mechanism were compared with those predicted by the detailed mechanism and experimental data,with satisfactory agreement being observed.Finally,this reduced mechanism was used in a three-dimension computational fluid dynamics software CONVERGE to simulate the combustion processes of a spark-ignited engine fueled with gasoline/butanol blends.The results showed that the in-cylinder combustion behaviors in this spark-ignited engine could be well captured by this reduced mechanism.