电控通用小型汽油机的喷油标定及性能研究

Fuel injection calibration and performance research on electronic control small non-road SI engine

降低通用小型汽油机排放,满足日益加严的排放法规是小型汽油机性能优化的首要任务。本文以168F通用小型汽油机为样机,由原机化油器供油改装为进气道电控喷油,以美国EPA第Ⅲ阶段排放法规为目标,对汽油机进行喷油标定,对试验结果计算分析,提出了通用小型汽油机低排放的理想油气混合比特性,应用它可使整机HC+NOX排放低,整机综合性能优化,形成了168F汽油机喷油的MAP。按EPA试验规范对整机与原机进行试验对比,168F汽油机采用电控喷油后,功率输出较原机提高9.8%,有效燃油消耗率降低了8.7%,CO排放下降了62.7%,HC+NOX下降了31.6%,排放满足了美国EPA第Ⅲ阶段限值。

Reducing emissions from small non-road SI engines to meet the increasingly stringent emission regulations is the essential task of making perfor- mance optimization. The 168F was taken as example and the original fuel providing method of carburetor was adjusted to the inlet electronic fuel injection. The U.S. EPA phase Ⅲemission regulations were set as the target to calibrate the fuel injection. The ideal fuel air ratio characteristics were proposed. The comparative test with the original engine was performed according to EPA regulation. When the 168F gasoline engine equipped with electronically controlled fuel injection system, the power output increases by 9.8% and the brake specific fuel consumption decreases by 8.7% than the original one. Besides, CO e- mission reduces by 62.7% and HC＋NOx emissions come to a drop of 31.6%, which meets the limits of U.S. EPA phase Ⅲ emission regulations.