Methodology for Selection of Gasoline Catalytic Convertor & Oxygen Sensor Position, Study on Oxygen Storage Capacity for 1.2L Turbocharger MPFI Engine

The results published in this paper emphasize on the study of three-way catalytic convertor for a 1.2 L turbocharged multi-point fuel injection gasoline engine. This paper takes us through the findings on methodology used for finalizing the brick configuration for catalytic convertor along with downstream oxygen sensor placement for emission control and methods applied for catalytic convertor selection with actual testing. The advantages of dual brick configuration over single brick with downstream sensor placed in between the bricks to enable faster dew point of sensor is explained using water splash test and design confirmation of better exhaust gas flow vortices concentration at the sensor tip for better sensing. Selection of catalytic convertor loading by testing its emission conversion capability and light-off behavior. NOx conversion capability across stoichiometric ratio (14.7:1 for petrol) on selected most operational zone was tested (±5% lambda) for the design-finalized samples acquired for testing. Also ability of faster light-off temperature (250–300°C) where conversion efficiency should be >95% is evaluated. Like wise it was also found that emission conversion efficiency is directly proportional to oxygen storage capacity of catalytic convertor with same configuration. On the other hand, an experiment on reverse aging for catalytic convertor was performed to monitor its improvement in oxygen storage capacity.