EXHAUST EMISSION CONTROL SYSTEM

摘要

PROBLEM TO BE SOLVED: To effectively improve temperature control responsiveness during regeneration of a filter.SOLUTION: In an exhaust emission control system, an oxidation catalyst 31, a NOx catalyst 32 and a filter 33 for collecting PMs are arranged in an exhaust passage 13 of an internal combustion engine 10 in this order from the upstream side. The exhaust emission control system includes: a temperature sensor 44 for acquiring a catalyst temperature of the NOx catalyst 32; an exhaust pipe injection device 34 for supplying fuel to the oxidation catalyst 31; and a filter forced regeneration control section 51 for executing filter regeneration for burning and removing the PMs from the filter 33 by supplying fuel from the exhaust pipe injection device 34 to the oxidation catalyst 31 when PM accumulation amount of the filter 33 reaches predetermined amount. The filter forced regeneration control section 51 performs feedback control of fuel supply amount of the exhaust pipe injection device 34 so that the catalyst temperature input from the temperature sensor 44 during regeneration of the filter becomes a predetermined target temperature.SELECTED DRAWING: Figure 1