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
早燃也叫超级爆震,是高增压汽油机一种异常燃烧方式。早燃发生时,缸内压力是正常气缸压力的1.5倍以上,爆震指数达到正常水平的10倍以上。研究了早燃产生的原因、早燃的危害及控制措施,基于某1.0 L 3缸增压直喷汽油机,通过手动将点火提...早燃也叫超级爆震,是高增压汽油机一种异常燃烧方式。早燃发生时,缸内压力是正常气缸压力的1.5倍以上,爆震指数达到正常水平的10倍以上。研究了早燃产生的原因、早燃的危害及控制措施,基于某1.0 L 3缸增压直喷汽油机,通过手动将点火提前角加大10°CA,进行了单缸600次早燃试验,并对2种火花塞分别进行了600次早燃冲击试验,然后将发动机进行拆解,分析零部件状态。同时,针对早燃产生的机理提出了几种抑制早燃的措施并加以验证。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.
文摘早燃也叫超级爆震,是高增压汽油机一种异常燃烧方式。早燃发生时,缸内压力是正常气缸压力的1.5倍以上,爆震指数达到正常水平的10倍以上。研究了早燃产生的原因、早燃的危害及控制措施,基于某1.0 L 3缸增压直喷汽油机,通过手动将点火提前角加大10°CA,进行了单缸600次早燃试验,并对2种火花塞分别进行了600次早燃冲击试验,然后将发动机进行拆解,分析零部件状态。同时,针对早燃产生的机理提出了几种抑制早燃的措施并加以验证。
