掺烧丁醇耦合米勒循环降低发动机NO和PM排放的仿真研究

A Simulation Research of Butanol Blended Combustion Plus Miller Cycle to Reduce Engine Emission of NO and PM

由于发动机机内净化技术在降低颗粒和NO排放方面存在trade-off效应,即降低NO排放会导致颗粒排放增加,为了缓解柴油机NO和PM排放之间"此消彼长"的矛盾,提出掺烧丁醇耦合米勒循环的仿真方案。利用AVL-FIRE软件建立4190Z_(L)C船用柴油机燃烧室仿真模型并验证了模型正确性;依据所建立的三维仿真模型,在额定工况下分析了丁醇掺混比、米勒度以及二者的耦合对柴油机排放特性的影响;以动力性能为约束条件,降低排放为评价指标,改变压缩比对耦合方案进行优化。仿真计算表明,掺混比B30结合米勒度M20方案与压缩比16.5匹配最优。在指示功率与原机保持一致的基础上,指示油耗率降低3.02%,NO质量分数降低13.6%,PM质量分数降低34.01%。

There is trade-off effect between emissions of PM and No.To decrease one will lead to the increase of the other.Butanol blended combustion plus Miller cycle is one of the potential schemes to have both of them reduced.A simulation experiment is designed to find optimal parameters.The combustion chamber model of 4190 Z_(L)C marine diesel engine is constructed with AVL-FIRE and verified.Simulation experiments with variable combination of butanol blended combustion and Miller cycle arrangements are performed.The simulations indicate that for the compression ratio of 16.5,the blending ratio B30 and Miller degree M20 combination works best.It is demonstrated that under same indicated output,the specific fuel consumption reduces by 3.02%,the NO mass fraction decreases by 13.6%and the PM mass fraction decreases by 34.01%.