Method and system for processing the detection amount of nitrogen oxides in diesel engines

Abstract

The invention relates to the technical field of nitric oxide sensors, and discloses a diesel engine nitric oxide detection volume treatment method and system, accordingly, accurate calibration of thenitric oxide sensors is achieved, and accurate measurement on the nitric oxide emission is achieved. The method comprises the steps that the work state and parameters of an engine are obtained, and the parameters include the rotation speed and the torque; when the work state is the motored state, zero point deflection calibration treatment is conducted on the nitric oxide detection volume; and when the rotation speed and the torque continue for the preset time within the set range and it is monitored that a selective catalytic reduction SCR postprocessing systems does not spray urea, compensation calibration treatment is conducted on the nitric oxide detection volume. The embodiment is applied to the treatment process for the nitric oxide detection volume of the nitric oxide sensors.

Description

technical field [0001] The present invention relates to the technical field of nitrogen oxide sensors, in particular to a method and system for processing the detected amount of nitrogen oxides in a diesel engine. Background technique [0002] Diesel engine emission control with SCR (Selective Catalytic Reduction, Selective Catalytic Reduction) after-treatment system is realized through accurate control of engine fuel injection plus accurate control of urea injection. At present, most diesel engine SCR aftertreatment systems will arrange one or more nitrogen oxide sensors on the aftertreatment catalytic package for the detection of nitrogen oxide emissions. Its working principle is to separate the nitrogen oxides entering the sensor through the catalyst coating inside the sensor to separate nitrogen ions and oxygen ions, and then determine the amount of nitrogen oxides through the charge change of the nitrogen oxide ions. Generally, for a nitrogen oxide sensor, the manufact...

AI Technical Summary

Problems solved by technology

However, with the increase of the running time and mileage of the engine and the aging of the after-treatment catalytic package, the inner coating of the nitrogen oxide sensor will inevitably be covered or aged by PM (particulate matter, particulate matter), which will make the detected The detected amount of nitrogen oxides deviates from the actual emission amount, which may lead to urea injection errors and OBD (On-Board Diagnostic) system monitoring errors, which is not conducive to precise engine emission control

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