中文摘要：

在一台加装了电控氢气喷射系统的四缸汽油机上,就点火角对汽油中掺混氢气时发动机性能的影响进行了试验研究。试验中发动机转速恒定在1400 r/min,混氢时通过调整氢气喷射脉宽使进气中氢气的体积分数为3%,同时调整汽油的喷射脉宽使混氢和不混氢两种条件下,发动机过量空气系数均保持在1.2。试验结果表明,与原机比较,混氢后发动机平均有效压力最大时的点火角延迟,燃烧持续期缩短,点火角相同时,HC和CO排放降低,但NOx排放有所增加;混氢时,随着点火提前角的增加燃烧速度明显加快,而排放物的变化趋势与原机相同：HC与NOx排放升高,而CO排放降低。

英文摘要：

Tests are carried out on a four-cylinder gasoline engine equipped with an electronically controlled hydrogen injection system to study the effects of ignition timing on engine performance when gasoline is blended with hydrogen.During tests engine speed is fixed at 1400r/min,and in hydrogen blending condition the hydrogen volume fraction in total intake mixture is kept at 3% by adjusting hydrogen injection pulse width.Meanwhile,gasoline injection pulse width is also adjusted to make excess air coefficient maintain at 1.2 for both W/WO hydrogen blending conditions.The test results show that compared with original engine,when gasoline is blended with hydrogen the ignition timing for maximum mean effective pressure retards,the duration of combustion reduces,HC and CO emissions lowers and NOx emission increases with same ignition timing.In hydrogen blending condition,when ignition timing advances combustion speed obviously increases with a same variation trend of emission as original engine： HC and NOx emissions rise and CO emission lowers.