The Study on Catalyst Light-Off Time and Emission Reduction of Turbo Gasoline Direct Injection EU5 Exhaust System

The future powertrain development is characterized by better fuel economy. To meet this, using turbo system in the engine is becoming more frequent in the vehicle development. But using turbo in the engine is only good for power and fuel economy, and not good for emission. That is because the turbo equipped engine loses lots of heat energy at the cold start due to the turbo mass. And thus for turbo engine, it is required to apply the technologies to shorten the catalyst light-off time to reduce the exhaust emissions. Especially when the turbo equipped vehicle is tested on NEDC cycle which is tested on urban low speed cycle at the start of the cycle, its emission is too much to meet the Euro5 regulation.

This paper investigates the successful ways to reduce the catalyst light-off time and exhaust emissions to meet the EU5 emission regulation in turbo gasoline direct injection(Turbo GDI) engine. So we do the comprehensive emission tests like increasing the precious metal and cell density, shortening the distance to the catalyst and applying additional device like secondary air. With these diverse tests, we come closer to meeting the EU5 emission.