基于DRG和QSSA方法的煤油详细燃烧机理简化

Reduction of kerosene detailed combustion reactionmechanism based on DRG and QSSA

关键词:  煤油  燃烧机理  直接关系图法  准稳态假设  骨架机理

Key words:  Kerosene  Combustion mechanism  DRG  QSSA  Skeletal mechanism

摘要:

利用直接关系图DRG和准稳态假设法QSSA发展了一套详细燃烧机理的简化程序。采用DRG对209组分1 673个反应的煤油详细燃烧动力学机理进行简化,取阈值0.6得到了包含84组分的骨架机理,并对骨架机理和详细机理的结果进行了对比和分析；在骨架机理的基础上采用QSSA方法,进一步得到了包含24组分20方程的简化反应模型。计算表明: 84组分的骨架机理在较宽的参数范围内得到的良搅拌反应器(PSR)结果和点火延迟数据都与详细机理一致；采用24组分20方程的总包反应模型得到的点火延迟、组分等数据都与详细机理结果非常接近。总包反应的组分数量满足CFD计算的要求,具有较好的工程应用前景。

Abstract:

A program for detailed combustion mechanism reduction was developed based on Direct Relation Graph (DRG) and Quasi Steady State Approximation (QSSA) method. By setting parameter to 0.6 in DRG, 84 species skeletal mechanisms were obtained for kerosene combustion containing 209 species and 1 673 reactions. Comparison and analysis was done between detailed and skeletal mechanisms. Then 24 species and 20 reactions reduced reaction model was generated by QSSA based on the skeletal mechanism. It demonstrated that PSR results and ignition delay time of 84 species skeletal mechanism agreed well with detailed mechanism over a wide range. The ignition delay and species data of 24 species and 20 reactions reduced model show good consistency with detailed model. The species number of global reaction model satisfies the need of CFD computation, so gives good perspective for engineering application.