A Compensate Method for Air Fuel Ratio in Gasoline Engine Start Process Based on Dynamic Fuel Film Model

During the gasoline engine start process, air fuel ratio of gasoline engine always greatly departs the theoretical air fuel ratio by the affection of intake pipe fuel film. To decrease exhaust emission in engine start process, the dynamic characteristic of intake pipe fuel film is analyzed; a new dynamic fuel film model of intake pipe based on Aquino model is presented, and a fuel compensation method based on theory of adverse is presented. Two conditions of a gasoline engine start process are simulated with SIMULINK based on presented model and the compensation method; the simulated results of air fuel ratio by present fuel film model and by Aquino model are given out. The result shows that, the presented intake pipe fuel film model and the fuel compensation method can compensate air fuel ratio near to the theoretical air fuel ratio in the gasoline engine start process.