边界参数对HCCI发动机燃烧影响的模拟研究

Simulation of effect of boundary parameters on combustion in HCCI engine

为了研究边界参数对柴油均质压燃(HCCI)发动机燃烧过程的影响,应用CHEMKIN化学动力学软件包中的SENKIN程序以及正庚烷(n-heptane)氧化反应简化模型,模拟了不同进气温度、进气压力和当量比等边界参数对HCCI发动机燃烧及排放特性的影响。结果表明,在相同当量比条件下,增压可以拓宽HCCI发动机负荷工况范围,同时保持氮氧化物排放基本不变;过浓或过稀的混合气导致CO排放增加;混合气浓度分层增加NO排放。

Both the SENKIN program of the chemical kinetic package CHEMKIN and the reduced model for n-heptane oxidation have been used to simulate the ignition and combustion process in diesel Homogeneous Charge Compression Ignition （HCCI） engine. The influences of intake temperature, intake pressure and equivalence ratio on HCCI combustion were investigated. The results showed that at constant equivalence ratio, the use of boost pressure can expand the load range of HCCI engine, and keep the NOx emissions little change. When the fuel/air mixture is too lean or too rich, CO emissions increases. Fuel mixture stratification causes the increase of NO emissions.