NOx emission estimation method and arrangement

摘要

A NO x emission estimation method and arrangement for a diesel engine for estimating the amount of NO x generated in a combustion chamber of the diesel engine. The method comprises the steps of: providing values for speed and load by measuring the engine speed and the fuel injection amount; providing a base NO x value from an engine speed-load resolved reference NO x map; defining and providing emission influencing input parameters by measuring corresponding signal values; calculating a deviation between at least one emission influencing input parameter and a speed-load resolved reference value for the at least one emission influencing input parameter; multiplying the calculated deviation with an individual value from an individual speed-load resolved weight map for the at least one emission influencing input parameter, thereby creating an emission influencing input parameter related correction for the at least one emission influencing input parameter; adding and summarizing the at least one emission influencing input parameter related correction to the base NO x value and thereby obtaining an estimated NO x mass flow value.