Lu An, Zhang Chunhua, Ji Peng, Li Yangyang
School of Automobile, Chang'an University, Xi'an, 710064, People's Republic of China.
Sci Rep. 2021 Jan 21;11(1):1904. doi: 10.1038/s41598-021-81490-3.
The experiments were conducted on a modified two-cylinder diesel engine to investigate the effects of excess-air coefficient (λ) and intake temperature (T) of different blending ratios (volume ratio of gasoline in the blends) on the combustion and emission characteristics of a Partially Premixed Compression Ignition (PPCI) engine. The results show that with the increase of gasoline blending ratio, the peak in-cylinder pressure (P), the peak in-cylinder temperature (T) and the peak heat release rate (HRR) of four test fuels all increase first and then decrease. When gasoline volume fraction is 10%, HC and CO emissions are the lowest. In addition, intake temperature (T) has a significant effect on the n-butanol/gasoline PPCI engine. With the increase of T, the in-cylinder P and HRR of four test fuels gradually increase, the combustion phase advances and HC and CO emissions decrease, while NOx emissions increase slightly. Furthermore, as λ increases, the P, T and HRR of the four test fuels show monotonously reducing trend. At the same time, mixture concentration has basically no effect on start of combustion (CA10), the combustion duration (CD) gradually extends, and HC and CO emissions increase.
实验在一台改装的双缸柴油机上进行，以研究过量空气系数（λ）和不同混合比（混合燃料中汽油的体积比）的进气温度（T）对部分预混压燃（PPCI）发动机燃烧和排放特性的影响。结果表明，随着汽油混合比的增加，四种测试燃料的缸内压力峰值（P）、缸内温度峰值（T）和放热率峰值（HRR）均先升高后降低。当汽油体积分数为10%时，HC和CO排放最低。此外，进气温度（T）对正丁醇/汽油PPCI发动机有显著影响。随着T的升高，四种测试燃料的缸内P和HRR逐渐升高，燃烧相位提前，HC和CO排放降低，而NOx排放略有增加。此外，随着λ的增加，四种测试燃料的P、T和HRR呈单调下降趋势。同时，混合气浓度对燃烧始点（CA10）基本无影响，燃烧持续期（CD）逐渐延长，HC和CO排放增加。
