AMMONIA OCCLUSION AMOUNT ESTIMATION DEVICE AND METHOD, AND PURIFICATION CONTROL APPARATUS AND METHOD

摘要

A purification controller 12 is configured to estimate the amount of ammonia occluded (i.e. ammonia occlusion amount) in an SCR catalyst 4, which is arranged in an exhaust pipe 52 of a diesel engine 51 so as to purify NOx in an exhaust gas of the diesel engine 51. More specifically, the purification controller 12 acquires upstream NO concentration data, upstream NO2 concentration data, downstream NOx concentration data, downstream NO2 concentration data and downstream ammonia concentration data. The purification controller 12 further acquires an urea injection amount. Then, the purification controller 12 estimates the ammonia occlusion amount based on the acquired upstream NO concentration data, upstream NO2 concentration data, downstream NOx concentration data, downstream NO2 concentration data and downstream ammonia concentration data, the acquired urea injection amount and reaction formulas for reduction of NOx with the SCR catalyst 4.

主权项

1. An ammonia occlusion amount estimation device for estimating the amount of ammonia occluded in a selective catalytic reduction catalyst as an ammonia occlusion amount, the selective catalytic reduction catalyst being arranged in an exhaust pipe of an internal combustion engine so as to purify NOx in an exhaust gas of the internal combustion engine, the ammonia occlusion amount estimation device comprising:
a first data acquisition section that acquires first concentration identification data identifying the concentrations of NO and NO2 in the exhaust gas flowing into the selective catalytic reduction catalyst as an upstream NO concentration and an upstream NO2 concentration, respectively, and identifying the concentration of NO, NO2 and ammonia in the exhaust gas flowing out of the selective catalytic reduction catalyst as a downstream NO concentration, a downstream NO2 concentration and a downstream ammonia concentration, respectively; a second data acquisition section that acquires second concentration identification data identifying the concentration of ammonia flowing into the selective catalytic reduction catalyst as an upstream ammonia concentration; and an occlusion amount estimation section that estimates the ammonia occlusion amount based on the first concentration identification data acquired by the first data acquisition section, the second concentration identification data acquired by the second data acquisition section and reaction formulas for reduction of NOx with the selective catalytic reduction catalyst.