Page 257 - Methods For Monitoring And Diagnosing The Efficiency Of Catalytic Converters A Patent - oriented Survey

Chapter 2.1

Emitec Gesellschaft fur Emissionstechnologie -
Dr. Ing. H.c.F. Porsche AG

Most of the methods presented in this chapter are applied to the engine layout of fig. 101.
In fig. 101, there is seen an internal combustion engine (I.C.E.) with an electronic engine
control, wherein in the present description the term "engine" always means the engine and all
of its peripheral equipment such as ignition, fuel injection and air delivery devices, with the
exception of measuring instruments and the engine control. The engine control unit (ECU)
receives information from outside through measurement value feed lines, and from the
information it ascertains control data, which are supplied to the engine through engine feed
lines. Exhaust gases pass in the direction of the arrow, from the engine into an exhaust gas line,
in which a lambda sensor h is disposed. The lambda sensor in turn is connected to the engine
control through a measured value line.

A catalytic converter is disposed in the exhaust gas line and is followed by an exhaust outlet
line or pipe. The catalytic converter may include one or more individual disks and naturally the
exhaust system can also be constructed as a dual or otherwise multiple system. The catalytic
converter may also be electrically heated, at least in sub-regions, and may have corresponding
electrical leads.
The catalytic converter has temperature sensors, which are connected to an electronic
monitoring apparatus by measurement lines . In this way, the temperature of the exhaust gases
upstream of the converter as well as the temperature of the walls or structures of the catalytic
converter is directly measured downstream of the engine. In principle, the measured
temperature values could also be carried from the temperature sensors directly to the engine
control, but in the present exemplary embodiment prior processing in the electronic monitoring

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