甲醇中低温着火延迟时间的计算模型

摘要

研究了甲醇在中低温条件下的氧化特性，通过对详细反应机理的分析，得到一个九步的骨干机理，在1,500,K 下其着火延迟时间预测值与详细机理的预测值基本一致。通过理论分析着火感应期内占主导作用的自由基行为，最后得到了一条能用于估算甲醇中低温着火延迟时间的显式公式。该公式显示甲醇在中低温下的着火延迟时间主要取决于CH3OH＋HO2→CH2OH＋H2O2的反应速率。该反应对甲醇在中低温下氧化特性有重要的影响。%The oxidation characteristics of methanol-air mixture at low-to-intermediate temperatures were investi-gated numerically in this work.Based on the analysis of the detailed kinetic mechanism of methanol,a nine-step skeletal model was developed and validated by comparing the computational ignition delay time under 1,500,K with that from detailed mechanism.With further analysis of auto-ignition behavior in a homogeneous adiabatic system,an explicit formula for ignition delay time was derived,which had a simple form and showed good agreement with nu-merical results.It was indicated that the ignition delay time of methanol-air mixture at low-to-intermediate tempera-tures was mainly controlled by the reaction rate of CH3OH+HO2→CH2OH+H2O2,which has a dominant effect on the oxidation behavior of methanol within this temperature range.