Control method for improving nitrogen oxide purification performance

摘要

A control method for improving nitrogen oxide purification performance (NOx) includes starting NOx regeneration, comparing first and second lambda values measured at first and second lambda sensors in a control unit, checking the lean NOx trap (LNT) temperature, and measuring a second time that has elapsed after the first and second lambda values are found to be the same, and checking whether the second time is greater than or equal to a predetermined time when it is observed that the temperature of the LNT is greater than or equal to the predetermined temperature value.

主权项

1. A control method for improving nitrogen oxide purification performance (NOx), comprising steps of:
starting a NOx regeneration process via a control unit by converting from a general driving mode to an enriched mode, in which a relative quantity of fuel in an engine is increased, and checking whether the enriched mode is maintained for a first time greater than a minimum holding time; comparing a first lambda value measured at a first lambda sensor, arranged upstream from a lean NOx trap (LNT), with a second lambda value measured at a second lambda sensor, arranged downstream from the LNT, via the control unit when the enriched mode is maintained for the first time greater than the minimum holding time; checking whether a temperature of the LNT is greater than or equal to a predetermined temperature value when the first lambda value is greater than or equal to the second lambda value; and measuring a second time that has elapsed after the first and second lambda values are found to be the same, and checking whether the second time is greater than or equal to a predetermined time when it is observed that the temperature of the LNT is greater than or equal to the predetermined temperature value.