SYSTEM AND METHOD FOR ENHANCING THE PERFORMANCE OF A SELECTIVE CATALYTIC REDUCTION DEVICE

摘要

A system and method is provided for enhancing the performance of an SCR device, particularly by routinely reducing the amount of reductant deposits accumulated in an exhaust gas system, when the reductant is injected at a reduced temperature. The system may include an engine, an exhaust gas system, an SCR device, an injection device, and a controller configured to execute the present method. The controller may be configured to select an initial injection rate and an initial injection temperature for the reductant; estimate the amount of accumulated reductant deposits present within the exhaust gas system; compare the amount of accumulated reductant deposits to a threshold amount of reductant deposits allowable in the exhaust gas system; and initiate a reductant deposit burn-off mode when the amount of accumulated reductant deposits is greater than the threshold amount of reductant deposits allowable in the exhaust gas system.

主权项

1. A method of improving the performance of a selective catalytic reduction (SCR) device of a vehicle having an engine and an exhaust gas system, the method comprising:
selecting, via a controller, an initial injection rate and an initial injection temperature for a reductant, the initial injection temperature defined as the temperature of the exhaust gas system when the reductant is injected; initiating, via the controller, an injection of the reductant into the exhaust gas system via an injection device, including injecting the reductant at the initial injection temperature and the initial injection rate; estimating, via a reductant deposit module, an instantaneous amount of accumulated reductant deposits present within the exhaust gas system based on each of the initial injection rate, the initial injection temperature, and an exhaust flow rate through the exhaust gas system; comparing, with the controller, the amount of accumulated reductant deposits to a threshold amount of deposits allowable in the exhaust gas system; and executing, via the controller, a first control action when the amount of accumulated reductant deposits is less than the threshold amount of deposits allowable in the exhaust gas system and a second control action when the amount of accumulated reductant deposits is greater than the threshold amount of deposits allowable in the exhaust gas system.