METHOD AND EQUIPMENT FOR MONITORING NORMALITY OF FUNCTION OFCATALYST EQUIPMENT IN EXHAUST GAS PATH OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a monitoring method for the operating capability of a catalyzer in an exhaust duct of an internal combustion engine, and an apparatus for performing the method. SOLUTION: Operating capability of a catalyzer is assessed on the basis of the increase in temperature produced by exothermic conversion of exhaust gases in the catalyzer. The increase in temperature is determined with the aid of two temperature signals. The first temperature signal THK is produced on the basis of a measurement downstream of the catalyzer, and the second temperature signal THKM is produced with the aid of a temperature model. The temperature model simulates the temperature downstream of a completely inoperational catalyzer, a catalyzer which is still just sufficiently operational, or a catalyzer which is fully operational. The assessment of the operating capability of the catalyzer is performed on the basis of criteria which are matched to the temperature model used.