Mechanism Simulation And Experiment Research Of NOx Adsorber Reduction Catalyst For Reducing NOx Emission Of Lean Burn Gasoline Engine

The lean burn technology was been paid widely attention, because of its great potential to improve fuel consumption and exhaust emission. However, how to reduce NOx emission in lean burn condition has become a key problem which determines that whether the lean burn technology can be applied in practice in internal combustion engine or not. After analyzing chemical reaction mechanisms in lean and rich burn process in adsorber reduction catalyst, applying CHEMKIN chemistry kinetics software, simulated reactions in the lean burn adsorber reduction catalyst.In order to validate whether the reaction mechanisms is right or not, Based on the former works of our research group, the variable induction and twice injection technologies have been used on Toyota 8A 16 valves EFI lean burn S.I engine, and realized quasi-homogeneous lean burn combustion below air fuel ratio 24. In order to stabilize the lean burn engine the torque output, an electronic control system of lean burn engine was been developed by author. When the A/F of the lean burn engine changes from the state of lean burn (A/F=21) to the state of less oxygen (A/F≤14.7), the system adjust throttle and ignition time automatically so as to obtain constant torque output. The constant torque output control technology when A/F is changed abruptly has been realized.After measuring NOx concentration of lean burn adsorber reduction catalyst on a certain state, and compare test results with the result of simulation on the same condition. The calculated results show that the reaction mechanisms calculating and test results have better consistence, and the reaction mechanisms can be used into controlling strategy of the lean burn adsorber reduction catalyst in the lean burn gasoline engine reality.