Turbocharging and direct injection are main technologies used for energy-saving gasoline engines. But the biggest challenge is super-knock, whose mechanism is unclear and has no effective strategy to suppress this sup...Turbocharging and direct injection are main technologies used for energy-saving gasoline engines. But the biggest challenge is super-knock, whose mechanism is unclear and has no effective strategy to suppress this super-knock until now. The effects of injection strategies on super-knock were experimentally investigated in a turbocharged GDI engine. It was found that two-stage injections during intake stroke （TSII） can eliminate super-knock. Meanwhile, the fuel consumption, emissions and exhaust tem- perature can keep optimized level. By sweeping the start of the 1st injection （SOIl）, end of the 2nd injection （EOI2） and the split injection ratios （ROI2） using 5000 cycles evaluation test at low-speed high load operating point, the optimized injection strategy for the typical TC-GDI engine is TSII with SOIl at middle of intake stroke, EOI2 at end of intake stroke, and ROI2 of 0.3.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51036004)the Ministry of Science and Technology of China through the Project 2012AA111715
文摘Turbocharging and direct injection are main technologies used for energy-saving gasoline engines. But the biggest challenge is super-knock, whose mechanism is unclear and has no effective strategy to suppress this super-knock until now. The effects of injection strategies on super-knock were experimentally investigated in a turbocharged GDI engine. It was found that two-stage injections during intake stroke （TSII） can eliminate super-knock. Meanwhile, the fuel consumption, emissions and exhaust tem- perature can keep optimized level. By sweeping the start of the 1st injection （SOIl）, end of the 2nd injection （EOI2） and the split injection ratios （ROI2） using 5000 cycles evaluation test at low-speed high load operating point, the optimized injection strategy for the typical TC-GDI engine is TSII with SOIl at middle of intake stroke, EOI2 at end of intake stroke, and ROI2 of 0.3.
