柴油机TR燃烧系统实现低温预混合燃烧的研究(英文)

Realization of Low-Temperature Premixed Combustion with Diesel TR Combustion System*

为了验证TR燃烧系统降低发动机排放、实现低温预混合燃烧的能力,在一台经过改造的单缸135柴油机上进行了降低压缩比、燃用柴油-乙醇混合燃料和推迟供油的试验研究。结果表明,压缩比ε降低后,着火推迟,最大放热率增加,缸内最高压力和最高温度降低,NOx排放也降低。但是中高负荷时燃烧速率降低,有效油耗率增加。当燃用乙醇体积含量20%的乙醇-柴油混合燃料时,与燃用柴油燃料相比,着火延迟期延长,烟度大幅度降低。小负荷时缸内最高压力、最高温度、最大放热率和燃烧速率都降低,NOx降低较多;中高负荷时最大放热率高于后者,燃烧速率提高,NOx降低得较少。当供油定时从15°CABT-DC推迟到13°CABTDC后,烟度基本不变。

To clarify the ability of TR(Three-rapidity) combustion systemfor reducing emissions and reali-zing low-temperature premixed combustion,a series of tests were carried out in a modified 135 single-cylin-der diesel engine ,including lowering compression ratio , using diesel-ethanol blend and delaying injectionti ming . The results show that the decreas of compression ratio results in ignition delay ,the increase inmaxi mumrate of heat release and maxi mumcylinder pressure ,the decrease in maxi mum mean gas tempera-ture and NOx. However ,at the mediumand high loads the combustion rate would decrease and the brakespecific fuel consumption would increase . Compared to diesel combustion,ethanol-diesel combustion pro-longs ignition delay period and remarkablylowers the exaust smoke . The maxi mumcylinder pressure , max-i mumgas temperature , maxi mum heat release rate and combustion rate will be decreased somewhat underlowload , while under mediumand high loads ,a higher heat release rate and quicker combustion rate pres-ent with little decreas of NOx.In addition,delaying of fuel delivery advance angle from 15°CA BTDC to13°CA BTDCleads to little variationin smoke at all .