燃料挥发性对柴油机性能及排放的影响

Effects of Fuel Volatility on Performances and Emissions of a Diesel Engine

针对不同的发动机热状态及压缩比,试验研究了燃料物化特性对柴油机稳态及过渡工况下性能、排放的影响规律。应用自行开发的柴油机过渡工况控制系统及排气采集装置,模拟车用柴油机实际工作时的加速状态,对具有相同十六烷值但有不同挥发性能燃料的HC排放特性进行了研究,利用气相色谱仪对HC排放成分进行了分析。研究结果表明,采用挥发性好的燃料,可有效降低排气烟度,提高有效热效率,在发动机热状态不好及压缩比较低等燃烧条件恶劣、HC排放高的情况下,可有效地降低HC排放。

Effects of fuel volatility on engine performances and emissions were studied under different thermal states and compression ratios at steady and transient operation modes of a single-cylinder DI diesel engine. Transient mode control system and exhaust collection system were developed for diesel transient operation. Effect of fuel volatility with the same cetane number on THC emission behavior of diesel engine was investigated and components of THC emissions were analyzed by gas chromatography. Results showed that under poor combustion conditions, such as low cooling temperature or low compression ratio, better volatile fuel emits less THC and smoke, achieves better thermal efficiency.