抄録
Controlling the autoignition timing over a wide range of speeds and loads is challenging. Overcoming this challenge to practical HCCI engines requires an improved understanding of fie in-cylinder processes and how these processes can be favorably altered by various control techniques. In the current study, a zero-dimensional thermodynamic model that contains a simple heat release sub-model and an autoignition model was used in a predictive fashion to better understand in-cylinder processes and the efficiency potential of a natural gas engine in HCCI mode. The model was also used for parametric studies to evaluate HCCI control strategies that can be tested on the research engine. The results indicated that if initial conditions of the mixture are known precisely at intake valve closing, the autoignition timing is controllable. The thermal efficiency close to 0.45 is possible with an IMEP range from 4 to 5 bar for the described engine, also.
