Exhaust gas purification apparatus for engine

摘要

An exhaust gas purification apparatus is provided with: a first soot-accumulation calculation unit 49 which calculates a first soot accumulation amount from an operation state of the engine; a second soot-accumulation calculation unit 51 which calculates a second soot accumulation amount from a total operation time of the engine, a total fuel consumption rate, a pressure difference between front and back of the particulate filter, and the like; a first soot-accumulation correction unit 55 which corrects the first soot accumulation amount calculated by the first soot-accumulation calculation unit 49 to a value greater than the first soot-accumulation amount when the active regeneration starts based on the second soot accumulation amount calculated by the second soot-accumulation calculation unit 51; and a regeneration ending unit 57 which ends the active regeneration when, in such a case that the active regeneration starts based on the corrected soot accumulation amount, the first soot accumulation amount becomes less than a threshold value of ending the regeneration.

主权项

1. An exhaust gas purification apparatus comprising:
a pre-oxidation catalyst configured to burn an unburned constituent contained in exhaust gas of an engine by catalysis; a particulate filter arranged downstream of the pre-oxidization catalyst to collect soot contained in the exhaust gas; a heating device configured to increase an amount of the unburned constituent to be supplied to the pre-oxidation catalyst to perform an active regeneration of the particulate filter; a first soot-accumulation calculation unit configured to calculate a first soot accumulation amount in the particulate filter from a first index, the first index being an operation state of the engine; a second soot-accumulation calculation unit configured to calculate a second soot accumulation amount from a second index, the second index being different from the first index and being at least one of a total operation time of the engine, a total fuel consumption rate, or a pressure difference between a front and back of the particulate filter; a regeneration starting unit configured to determine a starting of active regeneration when either one of the first soot accumulation amount and the second soot accumulation amount reaches a regeneration start threshold value; a first soot-accumulation correction unit configured to correct the first soot accumulation amount calculated by the first soot-accumulation calculation unit to a value greater than the first soot-accumulation amount when the starting of active regeneration is determined by the regeneration starting unit based on the second soot accumulation amount calculated by the second soot-accumulation calculation unit; and a regeneration ending unit configured to end the active regeneration when, in such a case that the active regeneration starts based on the corrected soot accumulation amount corrected by the first soot-accumulation correction unit, the first soot accumulation amount becomes less than a threshold value of ending the regeneration.