【摘要】 在一台2-135柴油机上实现了纯DME的均质压燃(HCC I)燃烧方式.实验结果表明,DME的HCC I燃烧模式不但可以实现无烟燃烧,还可以有效控制发动机NOx排放,使其接近于零排放.在实验负荷范围内,CO排放随负荷增加而降低;HC的排放随负荷增大而减少.对DME的HCC I燃烧机理进行研究表明,由于纯DME十六烷值高导致的着火比较早(上止点前28°CA左右),使得发动机只能在中低负荷较小范围内运行.为了扩展发动机工况,控制HCC I着火,进一步通过调节实验发动机压缩比,以及在优化的压缩比下,在进气道加入气体CO2或者在DME中加入LPG降低燃料十六烷值的方法来改进和控制HCC I的燃烧.实验表明以上方法可以有效控制HCC I燃烧,拓宽HCC I发动机运转范围.更多还原

【Abstract】 A 2-135 C.I. engine was modified to a DME（dimethyl-ether） HCCI（homogeneous charge compression ignition） combustion. The experimental results show that DME HCCI combustion produces almost zero NO_x emission and smokeless exhaust. Within the engine load range, the emissions of CO and HC decrease with the increase of engine load. The HCCI combustion of DME displays remarkable two-stage combustion characteristic. Because the first combustion stage starts at around 28° CA BTDC,the engine can only operate at med-low load range. The method of increasing fuel input to increase engine load range is likely to lead to knock. In this paper, inorder to control ignition and combustion phase of HCCI, combustion ratio is adjusted, diluent gas CO₂ is added to the engin intake flow and LPG is added to DME fuel to extend the range of engine of operation. The experimental results show that the above methods are effective in controlling HCCI combustion and enlarging engine load range.更多还原