Research On The Mechanism Of HC Emission During Cold Start For LPG SI Engine

With the great development of Chinese vehicle industry in the last decades, pollution and oil consumption have become major chanllenges for the further sustainable development. In order to control vehicle pollution more effectively, the tailpipe hydrocarbon (HC) measured during the US 1975 Federal Test Procedure (FTP 75) and ECE cycles have been required during the cold start, before the catalytic converter is turned on. As the HC emissions at cold-start are main part in the new test procedure, the study of cold-start on a LPG SI combustion engine total of this thesis would be helpful for the further cold-start research.In this research, the transient HC emissions device Cambustion HFR500 and the fast data collection system are employed. The effects of the piston crevice and spark ignition angle on the tailpipe HC emissions were studied. Based on large quantities of experiments and HC emission mechanisms, a two-zone combustion model and crevice HC emission model were set up.The comparison between the experiment data and simulation data shows that the models accord with the experiment results. But there are still lots of work to do for further perfect the models.