喷油压力和PODE掺混对柴油机颗粒物排放影响

Effect of injection pressure and PODE addition on particle matter emissions in a diesel engine

商用柴油机中排放的颗粒物对自然环境和人类健康有着越来越大的危害。为进一步研究喷油压力和PODE掺混比对降低柴油机颗粒物的潜力,在一台四缸增压柴油机上,进行了小负荷(BMEP=0.4MPa)和大负荷(BMEP=0.8MPa)工况下喷油压力和PODE掺混对柴油机颗粒物排放特性影响的试验研究。三种燃料分别为纯柴油(记为D100),PODE按体积比20%和30%与柴油进行掺混(分别记为PD20和PD30)。结果表明:在柴油中添加PODE能降低混合燃料的总颗粒物数浓度和质量浓度。在小负荷工况下,随着喷油压力升高,柴油/PODE混合燃料的总颗粒物和核态颗粒物数浓度增加,总颗粒物质量浓度变化不大。在大负荷工况下,与柴油相比,柴油/PODE混合燃料的总颗粒物数浓度和质量浓度降低。随着负荷增加,发动机排放的总颗粒物数浓度降低,总颗粒物质量浓度增加。在同一负荷下,随着喷油压力升高,总颗粒物数浓度进一步降低。

Particulate matter (PM) emitted from conventional diesel engines has more and more harm to natural environment and human health.In order to investigate the potential of injection pressure and polyoxymehty tene dimethyl ethers (PODE) blending ratio to reduce PM,the effects of injection pressure and PODE addition on PM emission characteristics of a four-cylinder supercharged diesel engine at low (BMEP= 0.4 MPa ) and high (BMEP=0.8 MPa) loads were tested and studied.The three blends were pure diesel (denoted as P0),a mixture of 80 % diesel and 20 % PODE (denoted as PD20),and a mixture of 70 % diesel and 30 % PODE (denoted as PD30),respectively.The results showed that the addition of PODE in pure diesel could reduce the total PM number and mass concentrations.At low load,the total PM and nucleation mode particle concentrations of blends decreased by increasing injection pressure.At high load,compared with diesel fuel,adding PODE to pure diesel could reduce total PM number and mass concentrations.As the engine loads increased,the total PM number concentration emitted from engine decreased,but the total PM mass concentration increased. At the same engine load,the total PM number concentration further decreased with the injection pressure increased.