Exhaust gas purification system for internal combustion engine, internal combustion engine, and exhaust gas purification method for internal combustion engine

Abstract

In this exhaust gas purification system 20 for an internal combustion engine, a lean NOx trap catalyst device 24 is provided to an exhaust passage 15 of an engine 10. A control device 40 for controlling the exhaust gas purification system 20 is configured such that a desulfurization temperature Tt, which serves as a target temperature for when performing desulfurization control on the lean NOx trap catalyst device 24, is set so as to correspond to the sulfur storage amount Sa stored in the lean NOx trap catalyst device 24. As a result, an exhaust gas purification system for an internal combustion engine, an internal combustion engine, and an exhaust gas purification method for an internal combustion engine are provided, with which, when desulfurization control is performed on the lean NOx trap catalyst device provided to the exhaust gas purification system for an internal combustion engine, desulfurization treatment is reliably performed while heat deterioration and erosion of the lean NOx trap catalyst device are inhibited, and desulfurization control exhibiting excellent robustness is performed, and thus a high NOx purification rate is maintained.

Description

technical field [0001] The present invention relates to an exhaust gas purification system for an internal combustion engine, an internal combustion engine, and an exhaust gas purification method for an internal combustion engine, and more particularly, to an internal combustion engine capable of suppressing thermal degradation and melting loss of a lean NOx trapping catalyst device and reliably performing desulfurization treatment Exhaust gas purification system, internal combustion engine and exhaust gas purification method of internal combustion engine. Background technique [0002] Generally, in order to purify the purification target components such as hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx) and particulate matter (PM) contained in the exhaust gas of internal combustion engines such as diesel engines, devices including oxidation catalysts ( Exhaust gas purification system for exhaust gas purification devices of various catalytic devices such as DO...

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Problems solved by technology

On the other hand, although NOx reverses in the range where the LNT catalyst temperature is hig

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