Exhaust gas cleaning system
First Claim
1. An exhaust gas cleaning system comprising:
- a particulate filter disposed in an exhaust passage of an engine configured and arranged to accumulate particulate matter in an exhaust gas discharged from the engine;
a pressure difference detecting section configured and arranged to detect a pressure difference in the exhaust passage between before and after the particulate filter;
an exhaust gas flow rate determining section configured and arranged to determine an exhaust gas flow rate;
an exhaust gas temperature detecting section configured and arranged to detect a temperature of the exhaust gas passing through the particulate filter; and
an accumulation state determining section configured and arranged to determine an accumulation state of the particulate matter in the particulate filter by obtaining a reference equivalent surface area of a passage inside the particulate filter based on the pressure difference detected in the pressure difference detecting section, the exhaust gas flow rate determined in the exhaust gas flow rate determining section, and the temperature of the exhaust gas detected in the exhaust gas temperature detecting section, the accumulation state determining section being further configured to obtain an adjusted equivalent surface area by adjusting the reference equivalent surface area based on a temperature of the particulate filter and the exhaust gas flow rate.
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Accused Products
Abstract
An exhaust gas cleaning system is provided that includes a particulate filter in an exhaust passage. The exhaust gas cleaning system is configured and arranged to determine an accumulation state of particulate matter in a particulate filter by obtaining a reference equivalent surface area of a passage inside the particulate filter based on a pressure difference between before and after the particulate filter, an exhaust gas flow rate, and a temperature of the exhaust gas passing through the particulate filter. The exhaust gas cleaning system is configured and arranged to obtain an adjusted equivalent surface area by adjusting the reference equivalent surface area based on a temperature of the particulate filter and the exhaust gas flow rate. Thus, an amount of particulate matter accumulated in a particulate filter of a diesel engine is accurately estimated without the estimation result being erroneously affected by the engine operating conditions.
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Citations
11 Claims
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1. An exhaust gas cleaning system comprising:
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a particulate filter disposed in an exhaust passage of an engine configured and arranged to accumulate particulate matter in an exhaust gas discharged from the engine;
a pressure difference detecting section configured and arranged to detect a pressure difference in the exhaust passage between before and after the particulate filter;
an exhaust gas flow rate determining section configured and arranged to determine an exhaust gas flow rate;
an exhaust gas temperature detecting section configured and arranged to detect a temperature of the exhaust gas passing through the particulate filter; and
an accumulation state determining section configured and arranged to determine an accumulation state of the particulate matter in the particulate filter by obtaining a reference equivalent surface area of a passage inside the particulate filter based on the pressure difference detected in the pressure difference detecting section, the exhaust gas flow rate determined in the exhaust gas flow rate determining section, and the temperature of the exhaust gas detected in the exhaust gas temperature detecting section, the accumulation state determining section being further configured to obtain an adjusted equivalent surface area by adjusting the reference equivalent surface area based on a temperature of the particulate filter and the exhaust gas flow rate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A particulate matter accumulation state determining method for an engine exhaust cleaning system comprising:
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determining an exhaust gas flow rate based on a fresh intake air flow rate and a fuel injection amount of the engine;
determining an exhaust gas pressure in a vicinity of an inlet of a particulate filter disposed in an exhaust passage based on the exhaust gas flow rate and a pressure difference in the exhaust passage between before and after the particulate filter;
determining an exhaust gas density based on the exhaust gas pressure and a temperature of the particulate filter;
determining a reference equivalent surface area of the particulate filter based on the exhaust gas flow rate and the exhaust gas density;
determining an adjustment coefficient based on the temperature of the particulate filter and the exhaust gas flow rate; and
determining an equivalent surface area of the particulate filter by multiplying the reference equivalent surface area by the adjustment coefficient.
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11. An exhaust gas cleaning system comprising:
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particulate matter accumulating means for accumulating particulate matter in an exhaust gas discharged from the engine;
pressure difference detecting means for detecting a pressure difference in an exhaust passage between before and after the particulate matter accumulating means;
exhaust gas flow rate determining means for determining an exhaust gas flow rate;
exhaust gas temperature detecting means for detecting a temperature of the exhaust gas passing through the particulate matter accumulating means; and
accumulation state determining means for determining an accumulation state of the particulate matter in the particulate matter accumulating means by obtaining a reference equivalent surface area of a passage inside the particulate matter accumulating means based on the pressure difference detected in the pressure difference detecting means, the exhaust gas flow rate determined in the exhaust gas flow rate determining means, and the exhaust gas temperature detected in the exhaust gas temperature detecting means, the accumulation state determining means being further configured to obtain an adjusted equivalent surface area by adjusting the reference equivalent surface area based on a temperature of the particulate matter accumulating means and the exhaust gas flow rate.
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Specification