柴油机加氢降低多环芳烃的数值研究

NUMERICAL STUDY ON POLYCYCLIC AROMATIC HYDROCARBONS REDUCTION BY ADDING HYDROGEN IN DIESEL ENGINES

为实现柴油机节能减排目标,结合燃料热解方法向柴油机中加入微量氢气是一种新思路。本文以数值研究方法,基于简化的包含多环芳烃生成的正庚烷氧化反应机理,通过三维CFD模拟方法研究了不同微量氢气添加量下柴油机燃烧室内的温度、压力曲线,以及典型多环芳烃生成曲线。计算研究结果表明,加入适当的微量氢气明显改善了柴油机燃烧室内的燃烧特性,并且可以使多环芳烃排放水平在一定数量级程度上得到减少。

For the goal of energy saving and emission reduction, slight amount of hydrogen addition to the diesel engine method combined with fuel pyrolysis is novel. Based on the n-heptane oxidation mechanism involving polycyclic aromatic hydrocarbons formation, curves of the temperature and pressure as well as some typical polycyclic aromatic hydrocarbons production inside the diesel cylinder under different hydrogen addition amount, have been obtained through three-dimensional CFD numeric calculation. Numeric simulation results indicate that the combustion characteris- tics of the diesel combustor have been notably improved when slight amount of hydrogen is added, and magnitudes of the polycyclic aromatic hydrocarbons＇ emission have been reduced in several orders.