Search Results

To meet LEV and EU Stage III emission requirements, it is necessary for new catalytic converters to be designed which exceed light-off temperature as quickly as possible. The technical solutions are secondary air injection, active heating systems such as the electrically heated catalytic converter, and the close coupled catalytic converter. Engine control functions are extensively used to heat the converter and will to play a significant role in the future. The concept of relocating the converter to a position close to the engine in an existing vehicle involves new conflicts. Examples include the space requirements, the thermal resistance of the catalytic coating and high temperature loads in the engine compartment.

Future requirements of the legislative body in the USA and Europe, towards the reduction of exhaust emissions of motor vehicles, forces the automobile industry to improve its technology continually. An electrically heated catalyst, abbreviated EHC, offers a very high potential for exhaust gas reduction in the cold start phase of the engine. A team of German automobile manufacturers is therefore developing a complete EHC System and laying down specifications which will enable the supply industry to undertake goal-orientated development of following components. The complete system comprises the components: heated catalyst, electricity supplier, electronic control, cables, plug and socket connections, secondary air system and their respective functions. In the following, the possible variations of the EHC system are explained and the components presented.