System, method, and apparatus for aftertreatment system monitoring

摘要

A method includes determining whether a urea refill event is detected, and clearing a quality accumulator value and clearing a latching abort command. The method includes determining whether urea fluid quality check abort conditions are met, and clearing the urea quality accumulator, latching the abort command, and exiting the reductant fluid quality check. In response to the abort conditions not being met, incrementing the urea quality accumulator according to an amount of urea being injected, and comparing the accumulated urea quantity to a low test threshold. The method includes, in response to the accumulated urea quantity being greater than the low test threshold, comparing the accumulated urea quantity to a high test threshold, and in response to the urea quantity being greater than the high test threshold, determining whether the a NOx exceedance is observed and clearing a urea quality error in response to the NOx exceedance not being observed.

主权项

1. A method for performing a reductant fluid quality check in a NOx reduction system with a controller, the NOx reduction system comprising a urea tank with the urea and a urea tank level sensor, the NOx reduction system further comprising a NOx reduction catalyst and a NOx sensor downstream of the NOx reduction catalyst, wherein the urea tank is con-ted to a urea injector for injection of the urea upstream of the NOx reduction catalyst, the method comprising:
refilling the urea tank; outputting a signal from the urea tank level sensor indicating a urea refill event for urea in the urea tank of the NOx reduction system is detected; determining whether urea fluid quality check abort conditions are met in response to the urea refill event being detected; in response to the urea fluid quality check abort conditions being met, clearing a urea quantity accumulator value in the controller, clearing a latching abort command in the controller, and exiting a urea fluid quality check operable by the controller; passing an exhaust flow with NOx through the NOx reduction catalyst and outputting a signal from the NOx sensor of a NOx amount measured downstream of the NOx reduction catalyst; injecting an amount of urea from the urea tank with the urea injector upstream of the NOx reduction catalyst of the NOx reduction system and in response to the urea fluid quality check abort conditions not being met incrementing the urea quantity accumulator value according the amount of urea; comparing an accumulated urea quantity injected by the urea injector from the urea tank to a low test threshold, and in response to the accumulated urea quantity being less than the low test threshold, exiting a current execution cycle of the urea fluid quality check; in response to the accumulated urea quantity being greater than the low test threshold, comparing the accumulated urea quantity injected by the urea injector from the urea tank to a high test threshold, and in response to the accumulated urea quantity injected from the urea tank by the urea injector being greater than the high test threshold, determining from the signal output by the NOx sensor whether a NOx exceedance out of the NOx reduction catalyst is observed and clearing a urea quality error in the controller in response to the NOx exceedance not being observed.