Experimental Study On Emission Behaviors Of Gasoline Engine Under Transient Operating Conditions

Compared with the usually steady operating conditions, the exhaust emissions and fuel consumption of gasoline engine under transient operating conditions are much more, which limits automobile dynamical characteristic and fuel economic characteristic on a certain degree. This paper study the exhaust emission process of gasoline engine under the start conditions in the low-temperature state, constant torque increasing or decreasing speed operating condition, seek the emission regulations, disclose the reason why the exhaust emissions of gasoline engine under transient operating conditions are more than under steady condition, optimize the work process of gasoline engine under transient operating conditions.According to the experimental aim, content and method, the test-bed of EFI Gasoline Engine including exhaust emission analyzer, water temperature controller, electric eddy current dynamometer, engine control system and so on are established. It can be used to do the experiments under steady operating conditions and transient operating conditions. Discussed the indirect measurement method about transient emissions and got some Emissions laws of gasoline engine under transient operating conditions.The paper contains following six Sections.The significance and present condition of investigation on gasoline engine emissions characteristics under transient operating conditions are expounded, the main works that this paper will make and research ideas are presented in chapter1.Some theories about the establishment of the VEA emissions analyzer measurement pipe second-order system model, simulation pipeline amplitude and frequency characteristics and phase frequency characteristics, and its measurement accuracy are proposed in chapter2.The test-bed and main experiment devices are introduced in chapter3.The chapter4 mainly including how to control the work conditions ,experiment process and recording the data of experiment.Deal with the experiment results, analysis the emissions curve of gasoline engine under the start conditions in the low-temperature state, constant torque increasing or decreasing speed operating condition in chapter5.The research conclusions and prospects of the paper are presented at last.