The Implement Of HCCI On Gasoline-fueled Engine With Variable Control Technology

The homogeneous charge compression ignition (HCCI) combustion mode is becoming a hot research for internal combustion engines. HCCI has advantages in terms of efficiency and reduced emission, which can not only ensure both the high dynamic and economic quality of the engine, but also efficiently reduce the NOx and PM emission.lt is a new combustion concept, which incorporates the best features and discards the disadvantages of both traditional spark ignition (SI) gasoline engine and compression ignition (Cl) diesel engine. Another remarkable characteristic of HCCI combustion is the extensive flexibility to many kinds of fuels.This paper describes the characteristics and resent development of HCCI mode, discusses the influencing factors and research progress about HCCI, analyzes and illuminates the feasibility of HCCI technology implement on gasoline engines, the problems facing the practicability in the HCCI engine development, and also bring forward many variable control technologies in details. This paper presents an experiment on a special gasoline engine using the schemes of variable compression ratio, variable fuel characteristics, variable intake charge temperature and variable exhaust valve timing. And at last it also indicates the technology trend for applying HCCI to gasoline engines in the future.The experiment described in this paper was conducted on a gasoline engine with special single cylinder, moderate compression ratios (10.4 and 15) and using two modes of HCCI control ( intake heating and NVO (Negative Valve Overlap)). Gasoline and diesel, the two basic fuels with very different characteristics and wide availability for conventional engine use, were blended as the HCCI engine fuel. The result confirm the expectation that these two different fuels with opposite but complementary properties can be used to reach a good compromise in HCCI combustion performance.The analysis indicated that the investigation ,which focus on the effects of variable fuels with different characters and cooperate with variable control technology on the combustion characters, performance parameters and emissions of HCCI, is an effective way to apply HCCI to the product engine and the main development direction to an success implement of HCCI.