MULINBUMP HCCI燃烧控制特性的试验和数值模拟

Experiments and CFD Modeling of MULINBUMP HCCI Engine Combustion Characteristics

通过试验和数值模拟方法研究了MULINBUMP HCCI燃烧控制特性.发动机试验表明,通过控制多脉冲喷射参数可以控制预混合气的形成,从而控制燃烧放热速率,获得很低的排放水平.在不采用废气再循环的条件下,NOx排放在低负荷时只有11×10-6,高负荷时也不超过250×10-6,烟度则始终小于0.5BSU.对多脉冲喷射预混合气形成历程的CFD数值模拟表明,不同的多脉冲喷射定时在混合气形成过程中形成不同的浓度和温度分层,从而引起燃烧特性的变化.通过控制多脉冲喷射参数来控制HCCI燃烧相位和燃烧速率是一种实用、有效的策略.

MULINBUMP HCCI combustion characteristics were investigated through experiments and numerical simulation. The experimental results show that preparation of premixed mixture can be controlled by setting parameters of multi-pulse injection at a certain engine operation condition for the purpose of controlling the phase and rate of heat release. This led to reductions of NOx and soot emissions simultaneously. The NOx emission was only 11×10-6 at lower engine load and less than 250×10-6 at higher load, and soot emission was always less than 0.5 BSU. Based on the CFD simulations, it was found that multi-injection timing was of paramount interests since it represented the relative effectiveness of fuel stratification for controlling HCCI combustion phasing.