| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control device that can compensate decline in NOx removal efficiency even when filter regeneration processing is executed.SOLUTION: When executing regeneration processing of a DPF 32 by injecting fuel from a fuel addition valve 34, a control device 60 makes a reduction correction of the estimated amount of sulfur (sulfur poisoning amount) adsorbed to each of a DOC 30 and the DPF 32. The control device 60 calculates the amount of the sulfur that has been desorbed from each of the DOC 30 and the DPF 32 through the filter regeneration processing and is adsorbed again to an SCR 36, and updates the sulfur poisoning amount of the SCR 36. Based on the updated sulfur poisoning amount of the SCR 36, the control device 60 sets an urea amount injected from a reducing agent addition valve 38.SELECTED DRAWING: Figure 1 |
