FIELD: chemistry.
SUBSTANCE: method of batching an ammonia-splitting reducing agent into a stream of exhaust gas in an internal combustion engine working with excess air involves the following. The control unit batches the amount of reducing agent depending on the model stored in memory. During operation of the internal combustion engine, by comparing a value proportional to the set emission or set conversion, stored in the memory of the control unit of the internal combustion engine for the corresponding operating point of the internal combustion engine or and/or exhaust gas post-treatment apparatus, with a value proportional to the actual emission or actual conversion, determined by the control unit based on measurements, the control unit calculates the deviation between the actual and set emission values or between the actual and set conversion values. Depending on this deviation, the control unit determines the adjustment for the batched amount, and the model stored in memory is modified by this adjustment during the following batching operations. Determination of the actual emission or actual conversion is carried out such that the control unit sums up or integrates measurement data of a NOx sensor behind the SCR-catalyst and/or a NH3 and/or a N2O sensor and/or a HNCO sensor and/or a lambda sensor, or sums up or integrates the actual conversion determined using at least one of said sensors and values of untreated emissions, during a given period of time t or until achieving a given amount of emissions, or until summation or integration of at least one working parameter reaches a given value, and simultaneously checks whether that at least one working parameter lies inside one region of measurement from at least two regions of measurement, wherein regions of measurement are determined from values stored in the control unit.
EFFECT: use of the disclosed method enables to account for the effect of ambient medium and reduce inertia of the purification system.
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