WO2013042190A1 - 内燃機関の排気浄化装置 - Google Patents
内燃機関の排気浄化装置 Download PDFInfo
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- WO2013042190A1 WO2013042190A1 PCT/JP2011/071347 JP2011071347W WO2013042190A1 WO 2013042190 A1 WO2013042190 A1 WO 2013042190A1 JP 2011071347 W JP2011071347 W JP 2011071347W WO 2013042190 A1 WO2013042190 A1 WO 2013042190A1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9459—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts
- B01D53/9477—Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts with catalysts positioned on separate bricks, e.g. exhaust systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9495—Controlling the catalytic process
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/105—General auxiliary catalysts, e.g. upstream or downstream of the main catalyst
- F01N3/106—Auxiliary oxidation catalysts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
- F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N9/00—Electrical control of exhaust gas treating apparatus
- F01N9/002—Electrical control of exhaust gas treating apparatus of filter regeneration, e.g. detection of clogging
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2067—Urea
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9404—Removing only nitrogen compounds
- B01D53/9409—Nitrogen oxides
- B01D53/9431—Processes characterised by a specific device
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/944—Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2550/00—Monitoring or diagnosing the deterioration of exhaust systems
- F01N2550/04—Filtering activity of particulate filters
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
- F01N2560/05—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being a particulate sensor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/04—Methods of control or diagnosing
- F01N2900/0422—Methods of control or diagnosing measuring the elapsed time
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/06—Parameters used for exhaust control or diagnosing
- F01N2900/16—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust apparatus, e.g. particulate filter or catalyst
- F01N2900/1622—Catalyst reducing agent absorption capacity or consumption amount
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Definitions
- the present invention relates to an exhaust purification device for an internal combustion engine.
- an accumulation amount of an intermediate product generated in the course of the reaction from urea to ammonia in the exhaust passage Is known to prohibit the supply of urea water when the amount reaches the upper limit (see, for example, Patent Document 1).
- the reducing agent can be supplied to the NOx catalyst until the accumulation amount of the intermediate product in the exhaust passage reaches the upper limit amount.
- a filter for collecting particulate matter (hereinafter also simply referred to as “PM”) may be provided in the exhaust passage. Further, in order to determine the failure of the filter, a PM sensor that detects the amount of PM in the exhaust gas may be provided. If the intermediate product adheres to the electrode or cover of the PM sensor, it may be difficult to accurately detect the PM amount. As a result, the accuracy of the filter failure determination may be lowered.
- the present invention has been made in view of the above-described problems, and an object of the present invention is to suppress a decrease in the accuracy of filter failure determination due to a decrease in detection accuracy of the PM sensor.
- an exhaust gas purification apparatus for an internal combustion engine comprises: A selective reduction type NOx catalyst for reducing NOx by a reducing agent provided in an exhaust passage of an internal combustion engine and supplied; A supply device for supplying urea water as a reducing agent from the upstream side of the selective reduction type NOx catalyst; A PM sensor for detecting the amount of particulate matter in the exhaust gas downstream of the selective reduction NOx catalyst; When the amount of particulate matter is detected by the PM sensor, intermediate products from urea water supplied to the ammonia to ammonia are generated rather than when the amount of particulate matter is not detected by the PM sensor. A control unit to reduce the amount, Is provided.
- the urea water supplied into the exhaust gas from the supply device changes to ammonia (NH 3 ).
- ammonia NH 3
- intermediate products ranging from urea water supplied from the supply device to ammonia finally produced pass through the selective reduction type NOx catalyst and adhere to the PM sensor. There are things to do. If an intermediate product adheres to the PM sensor, the output value of the PM sensor changes, making it difficult to accurately detect PM. On the other hand, when the amount of particulate matter is detected by the PM sensor, the control unit reduces the amount of intermediate product generated.
- the internal combustion engine is controlled so that the amount of intermediate products generated is reduced. Therefore, since it can suppress that the detection value of PM sensor changes with an intermediate product, it can suppress that the precision of the failure determination of a filter falls.
- the control unit when the amount of particulate matter is detected by the PM sensor, the control unit reduces the supply amount of urea water compared to when the amount of particulate matter is not detected by the PM sensor. be able to.
- reducing the supply amount of urea water includes stopping the supply of urea water.
- control unit can set the time for reducing the supply amount of urea water to be equal to or less than the specified time before the detection of the amount of particulate matter by the PM sensor.
- the specified time may be a time during which the average value of the NOx emission amount is within the allowable range.
- a filter is provided in an exhaust passage upstream of the PM sensor and collects particulate matter in the exhaust gas, and the control unit is configured to detect the intermediate product when determining a failure of the filter. The amount produced can be reduced.
- the filter failure determination can be performed in a state where the detection accuracy of the PM sensor is high, the failure determination accuracy can be increased.
- detection of particulate matter by the PM sensor is started when the amount of ammonia adsorbed by the selective reduction NOx catalyst is equal to or less than a predetermined amount, and the predetermined amount is determined by the internal combustion engine.
- the upper limit of the amount of ammonia that can be adsorbed by the selective reduction NOx catalyst calculated based on the degree of deterioration of the selective reduction NOx catalyst obtained during the previous operation of the particulate matter, and detection of particulate matter by the PM sensor It may be calculated based on the amount of ammonia adsorbed by the selective reduction NOx catalyst.
- the selective reduction type NOx catalyst cannot adsorb NH 3 and the intermediate product flows downstream. Therefore, if the amount of NH 3 adsorbed by the selective reduction NOx catalyst does not exceed the limit when detecting the PM amount, the detection accuracy of the PM sensor can be increased. That is, the PM amount may be detected when the amount of NH 3 adsorbed by the selective reduction type NOx catalyst is relatively small. For this reason, detection of PM by the PM sensor is started when the amount of NH 3 adsorbed by the selective reduction NOx catalyst is equal to or less than a predetermined amount. This predetermined amount is set as an adsorption amount at which the adsorbed NH 3 amount does not reach the upper limit even if the selective reduction type NOx catalyst adsorbs NH 3 thereafter.
- the predetermined amount may be determined according to the degree of deterioration of the selective reduction type NOx catalyst.
- the amount of NH 3 adsorbed by the selective reduction type NOx catalyst before a certain amount of PM adheres to the PM sensor varies depending on the operating state of the internal combustion engine. That is, the amount of NH 3 adsorbed by the selective reduction type NOx catalyst varies depending on the amount of NOx discharged from the internal combustion engine. For this reason, the predetermined amount may be determined according to the amount of NH 3 adsorbed by the selective reduction type NOx catalyst during detection of PM. This amount of NH 3 can be calculated based on, for example, the amount of NOx discharged from the internal combustion engine until a certain amount of PM adheres to the PM sensor and the NOx purification rate.
- the amount of intermediate product produced can be increased by increasing the temperature of the selective reduction NOx catalyst or the exhaust temperature, reducing the exhaust flow rate, or reducing the amount of reducing agent adsorbed on the selective reduction NOx catalyst. May be reduced.
- the present invention it is possible to suppress a decrease in the accuracy of filter failure determination due to a decrease in detection accuracy of the PM sensor.
- FIG. 3 is a flowchart illustrating a flow of filter failure determination according to the first embodiment.
- 6 is a time chart showing the transition of the amount of NH 3 adsorbed by the NOx catalyst.
- 10 is a flowchart illustrating a flow of filter failure determination according to the second embodiment.
- FIG. 1 is a diagram showing a schematic configuration of an exhaust gas purification apparatus for an internal combustion engine according to the present embodiment.
- the internal combustion engine 1 shown in FIG. 1 is a diesel engine, but may be a gasoline engine.
- An intake passage 2 and an exhaust passage 3 are connected to the internal combustion engine 1.
- An air flow meter 11 that detects the amount of intake air flowing through the intake passage 2 is provided in the intake passage 2.
- an oxidation catalyst 4 a filter 5, an injection valve 6, and a selective reduction type NOx catalyst 7 (hereinafter referred to as NOx catalyst 7) are provided in order from the upstream side in the exhaust flow direction.
- the oxidation catalyst 4 may be any catalyst having oxidation ability, and may be, for example, a three-way catalyst.
- the oxidation catalyst 4 may be carried on the filter 5.
- the filter 5 collects PM in the exhaust.
- the filter 5 may carry a catalyst. As PM is collected by the filter 5, PM gradually accumulates on the filter 5. Then, by performing a so-called regeneration process of the filter 5 that forcibly increases the temperature of the filter 5, the PM deposited on the filter 5 can be oxidized and removed.
- the temperature of the filter 5 can be raised by supplying HC to the oxidation catalyst 4.
- the temperature of the filter 5 may be raised by discharging hot gas from the internal combustion engine 1.
- the injection valve 6 injects a reducing agent.
- a reducing agent for example, an ammonia-derived one such as urea water is used.
- the urea water injected from the injection valve 6 is hydrolyzed by the heat of the exhaust to become ammonia (NH 3 ), and part or all of it is adsorbed on the NOx catalyst 7.
- NH 3 ammonia
- the injection valve 6 corresponds to the supply device in the present invention.
- the NOx catalyst 7 reduces NOx in the exhaust when a reducing agent is present. For example, if ammonia (NH 3 ) is previously adsorbed on the NOx catalyst 7, NOx can be reduced with ammonia when NOx passes through the NOx catalyst 7.
- a reducing agent for example, if ammonia (NH 3 ) is previously adsorbed on the NOx catalyst 7, NOx can be reduced with ammonia when NOx passes through the NOx catalyst 7.
- a first exhaust temperature sensor 12 for detecting the exhaust temperature is provided in the exhaust passage 3 upstream of the oxidation catalyst 4.
- a second exhaust temperature sensor 13 for detecting the temperature of the exhaust gas is provided in the exhaust passage 3 downstream of the oxidation catalyst 4 and upstream of the filter 5.
- the exhaust passage 3 downstream of the filter 5 and upstream of the injection valve 6 is provided with a third exhaust temperature sensor 14 for detecting the exhaust temperature and a first NOx sensor 15 for detecting the NOx concentration in the exhaust. Yes.
- a second NOx sensor 16 for detecting the NOx concentration in the exhaust and a PM sensor 17 for detecting the PM amount in the exhaust are provided in the exhaust passage 3 downstream of the NOx catalyst 7. All of these sensors are not essential and can be provided as needed.
- the internal combustion engine 1 configured as described above is provided with an ECU 10 that is an electronic control unit for controlling the internal combustion engine 1.
- the ECU 10 controls the internal combustion engine 1 in accordance with the operating conditions of the internal combustion engine 1 and the driver's request.
- the ECU 10 includes an accelerator opening sensor 18 that outputs an electric signal corresponding to the amount of depression of the accelerator pedal and can detect the engine load, and a crank position sensor 19 that detects the engine speed via electric wiring. And the output signals of these sensors are input to the ECU 10.
- the injection valve 6 is connected to the ECU 10 via electric wiring, and the injection valve 6 is controlled by the ECU 10.
- the ECU 10 performs a regeneration process of the filter 5 when the amount of PM accumulated on the filter 5 exceeds a predetermined amount.
- the regeneration process of the filter 5 may be performed when the travel distance of the vehicle on which the internal combustion engine 1 is mounted becomes equal to or greater than a predetermined distance. In addition, the regeneration process of the filter 5 may be performed every specified period.
- the ECU 10 determines a failure of the filter 5 based on the PM amount detected by the PM sensor 17.
- the PM sensor 17 determines a failure of the filter 5 based on the PM amount detected by the PM sensor 17.
- a failure such as breakage of the filter 5 occurs, the amount of PM passing through the filter 5 increases. If this increase in PM amount is detected by the PM sensor 17, the failure of the filter 5 can be determined.
- the failure determination of the filter 5 is based on the integrated value of the PM amount calculated during a predetermined period calculated based on the detection value of the PM sensor 17 and the PM during the predetermined period when the filter 5 is assumed to be in a predetermined state. This is done by comparing the integrated value of the quantity.
- the failure determination of the filter 5 may be performed based on the amount of increase in the detection value of the PM sensor 17 during a predetermined period. For example, it may be determined that the filter 5 has failed when the amount of increase in the detection value of the PM sensor 17 during a predetermined period is equal to or greater than a threshold value.
- FIG. 2 is a schematic configuration diagram of the PM sensor 17.
- the PM sensor 17 is a sensor that outputs an electrical signal corresponding to the amount of PM deposited on itself.
- the PM sensor 17 includes a pair of electrodes 171 and an insulator 172 provided between the pair of electrodes 171.
- the electrical resistance between the pair of electrodes 171 changes. Since this change in electrical resistance has a correlation with the amount of PM in the exhaust, the amount of PM in the exhaust can be detected based on the change in the electrical resistance.
- This amount of PM may be the mass of PM per unit time, or may be the mass of PM in a predetermined time.
- the configuration of the PM sensor 17 is not limited to that shown in FIG. That is, any PM sensor may be used as long as it detects PM and changes the detection value due to the influence of the reducing agent.
- FIG. 3 is a time chart showing the transition of the detection value of the PM sensor 17.
- the period indicated by A immediately after the start of the internal combustion engine 1 is a period during which water condensed in the exhaust passage 3 may adhere to the PM sensor 17. If water adheres to the PM sensor 17, the detection value of the PM sensor 17 changes or the PM sensor 17 breaks down. Therefore, the PM amount is not detected by the PM sensor 17 during this period.
- PM removal processing processing for removing PM adhering to the PM sensor 17 during the previous operation of the internal combustion engine 1
- This PM removal process is performed by raising the temperature of the PM sensor 17 to a temperature at which PM is oxidized. Even during the period indicated by B, the PM amount is not detected by the PM sensor 17.
- the period indicated by C after the period indicated by B is a period required to reach a temperature suitable for PM detection. That is, since the temperature of the PM sensor 17 becomes higher than the temperature suitable for PM detection in the period indicated by B, the process waits until the temperature decreases and becomes a temperature suitable for PM detection. Even during the period indicated by C, the PM amount is not detected by the PM sensor 17.
- the detected value does not increase until a certain amount of PM is deposited on the PM sensor 17. That is, the detection value starts increasing after a certain amount of PM is deposited and a current flows between the pair of electrodes 171. Thereafter, the detected value increases in accordance with the amount of PM in the exhaust gas.
- the PM sensor 17 is provided on the downstream side of the filter 5. Therefore, PM that has passed through the filter 5 adheres to the PM sensor 17 without being collected by the filter 5. Therefore, the PM accumulation amount in the PM sensor 17 is an amount corresponding to the integrated value of the PM amount that has passed through the filter 5.
- FIG. 4 is a time chart showing the transition of the detection value of the PM sensor 17 when the filter 5 is normal and when it is malfunctioning.
- PM accumulates early on the PM sensor 17, so that the time point E at which the detection value starts increasing is earlier than that of the normal filter 5. For this reason, for example, if the detected value when the predetermined time F has elapsed since the start of the internal combustion engine 1 is equal to or greater than the threshold value, it can be determined that the filter 5 has failed.
- the predetermined time F is a time when the detection value of the PM sensor 17 does not increase if the filter 5 is normal, and the detection value of the PM sensor 17 increases if the filter 5 is faulty. is there.
- This predetermined time F is obtained by experiments or the like.
- the threshold value is obtained in advance by experiments or the like as the lower limit value of the detection value of the PM sensor 17 when the filter 5 is out of order.
- the PM sensor 17 is provided downstream of the filter 5 and upstream of the NOx catalyst 7.
- the distance from the filter 5 to the PM sensor 17 is shortened.
- PM that has passed through the cracked portion of the filter 5 reaches the periphery of the PM sensor 17 without being dispersed in the exhaust gas.
- PM hardly adheres to the PM sensor 17, so PM may not be detected, and the accuracy of failure determination may be reduced.
- the PM sensor 17 is provided downstream of the NOx catalyst 7, the distance from the filter 5 to the PM sensor 17 is long. For this reason, PM that has passed through the filter 5 is dispersed in the exhaust around the PM sensor 17. Therefore, PM can be detected regardless of the position where the filter 5 is broken.
- the PM sensor 17 is provided on the downstream side of the injection valve 6, the reducing agent injected from the injection valve 6 may adhere to the PM sensor 17.
- the reducing agent adhering to the PM sensor 17 is, for example, urea and intermediate products (biuret, cyanuric acid) from urea to ammonia. If the reducing agent adheres to the PM sensor 17 in this way, the detection value of the PM sensor 17 may change.
- FIG. 5 is a time chart showing the transition between when the detection value of the PM sensor 17 is normal and when it is abnormal.
- the abnormal detection value can be a detection value when the reducing agent adheres to the PM sensor 17.
- the normal detection value increases over time, or the detection value does not change. That is, the detected value increases in accordance with the amount of PM attached to the PM sensor 17.
- an abnormal detection value may decrease as well as increase in the detection value.
- biuret which is an intermediate product, is produced at 132-190 ° C., and vaporizes when the temperature becomes higher than that.
- cyanuric acid which is an intermediate product, is produced at 190 to 360 ° C., and vaporizes when the temperature becomes higher than that.
- the intermediate product is vaporized at a low temperature as compared with PM. For this reason, the intermediate product adhering to the PM sensor 17 is vaporized when the temperature of the exhaust gas from the internal combustion engine 1 is high. As a result, the amount of intermediate product deposited decreases, and the detection value of the PM sensor 17 decreases. This is a phenomenon that does not occur when only PM is deposited on the PM sensor 17.
- FIG. 6 is a diagram showing the relationship between the supply amount of urea water and the adhesion amount of the intermediate product to the PM sensor 17. As shown in FIG. 6, the larger the amount of urea water supplied, the greater the amount of intermediate product attached to the PM sensor 17. Therefore, the amount of intermediate product attached to the PM sensor 17 can be reduced by reducing the supply amount of urea water.
- the urea water supply amount may be adjusted so that the average value of the NOx emission amount when the vehicle on which the internal combustion engine 1 is mounted travels a predetermined distance is within the allowable range. Further, the urea water supply amount may be adjusted so that the NOx emission amount per unit time is within the allowable range. Further, by limiting the time for adjusting the supply amount of urea water, the time for the NOx purification rate to decrease may be shortened.
- FIG. 7 is a time chart showing the transition of the supply amount of urea water and the discharge amount of NOx into the atmosphere.
- a request for failure determination of the filter 5 is made.
- the request for determining the failure of the filter 5 is made, for example, every predetermined traveling distance or after the regeneration processing of the filter 5. Then, after the time point indicated by G, the supply amount of urea water is decreased.
- the NOx emission increases as the urea water supply decreases.
- the supply amount of urea water is controlled so that the NOx emission amount is equal to or less than the upper limit value of the allowable range (hereinafter referred to as the allowable upper limit value).
- This allowable upper limit value may be the upper limit value of the allowable range of the NOx emission amount per unit time. Further, the allowable upper limit value may be an upper limit value of the NOx emission amount per unit time such that the average value of the NOx emission amount is within the allowable range.
- the supply amount of urea water may be set based on the engine speed and the engine load. The relationship between the supply amount of urea water, the engine speed and the engine load may be obtained in advance by experiments or the like. Further, the supply amount of urea water may be feedback controlled based on the NOx concentration in the exhaust gas detected by the second NOx sensor 16.
- the internal combustion engine 1 may be controlled so that the amount of NOx generated in the internal combustion engine 1 is reduced. Furthermore, when the PM amount is detected by the PM sensor 17, another control that makes it difficult for the intermediate product (biuret, cyanuric acid) to adhere to the PM sensor 17 may be combined.
- the internal combustion engine 1 may be controlled so that the temperature of the NOx catalyst 7 or the temperature of the exhaust gas becomes higher. Further, the internal combustion engine 1 may be controlled so that the flow rate of the exhaust gas decreases or the flow rate of the exhaust gas decreases. Further, the internal combustion engine 1 may be controlled so that the adsorption rate of NH 3 in the NOx catalyst 7 is lowered or the adsorption amount of NH 3 is reduced.
- the reaction such as thermal decomposition of urea takes time, so that it passes through the NOx catalyst 7 before the reaction of urea is completed. Therefore, the intermediate product can be prevented from flowing out of the NOx catalyst 7 by increasing the temperature of the NOx catalyst 7 or the exhaust gas.
- the flow rate of the exhaust gas is large, the time for urea to contact the NOx catalyst 7 is shortened, so that it passes through the NOx catalyst 7 before the urea reaction is completed. Therefore, it is possible to suppress the intermediate product from flowing out of the NOx catalyst 7 by reducing the flow rate of the exhaust gas.
- the exhaust flow rate may be lowered, or the intake air amount of the internal combustion engine 1 may be reduced.
- the NH 3 adsorption rate is a ratio of the amount of NH 3 adsorbed on the NOx catalyst 7 to the amount of NH 3 that can be adsorbed to the NOx catalyst 7 to the maximum.
- FIG. 8 is a flowchart showing a flow for determining the failure of the filter 5 according to the present embodiment. This routine is executed by the ECU 10 when a failure determination request for the filter 5 is made.
- step S101 it is determined whether a specified time (for example, 5 minutes) has elapsed since the supply amount of urea water was reduced. That is, it is determined whether the specified time has elapsed since the NOx emission amount increased.
- a specified time for example, 5 minutes
- the supply amount of the urea water is an amount that can suppress the generation of the intermediate product.
- the supply amount of urea water may be zero. That is, the supply of the reducing agent may be stopped.
- Specified time is set as the time when the average value of NOx emissions is within the allowable range even if the amount of NOx emissions increases. That is, even if the NOx emission amount increases when the failure of the filter 5 is determined, if the NOx emission amount is small at other times, the average value of the NOx emission amount is within the allowable range. Thus, even if the supply amount of urea water is decreased, the specified time is set as the time during which the average value of the NOx emission amount is within the allowable range. This specified time is obtained in advance by experiments or the like and stored in the ECU 10.
- step S101 If a negative determination is made in step S101, the process proceeds to step S102.
- step S102 the supply amount of urea water is adjusted.
- step S103 it is determined whether the average value of the NOx emission amount from the NOx catalyst 7 is within the allowable range. In this step, it may be determined whether the NOx emission amount per unit time is equal to or less than the allowable upper limit value shown in FIG. The NOx emission amount per unit time is obtained based on the detection value of the second NOx sensor 16. If a positive determination is made in step S103, the process returns to step S101. On the other hand, if a negative determination is made in step S103, the process returns to step S102. Thus, the supply amount of urea water is adjusted in step S102 until the average value of the NOx emission amount from the NOx catalyst 7 falls within the allowable range.
- the ECU 10 that processes steps S101 to S103 corresponds to the control unit in the present invention.
- step S104 it is determined whether or not it is within a predetermined time (for example, 60 seconds) after the regeneration processing of the filter 5 is performed.
- the regeneration process of the filter 5 is performed by raising the temperature of the filter 5 to a temperature at which PM is oxidized. By raising the temperature of the filter 5 in this way, the temperature of the PM sensor 17 also rises, and the intermediate product adhering to the PM sensor 17 is removed. Therefore, if the failure determination of the filter 5 is performed at this time, the detection value of the PM sensor 17 is not affected by the intermediate product, so that the accuracy of the failure determination is increased. Therefore, when an affirmative determination is made in step S104, the process proceeds to step S105, and a failure determination of the filter 5 is performed.
- step S106 the internal combustion engine 1 is controlled so that the temperature of the NOx catalyst 7 or the temperature of the exhaust downstream of the NOx catalyst 7 becomes a temperature at which the intermediate product vaporizes (for example, 360 ° C.).
- the temperature of the NOx catalyst 7 or the downstream of the NOx catalyst 7. Increase the exhaust temperature.
- the cover of the PM sensor 17 may be heated to 360 ° C. with a heater.
- the intermediate product can be removed from the PM sensor 17.
- biuret which is an intermediate product is vaporized at 190 ° C. or higher
- cyanuric acid is vaporized at 360 ° C. or higher.
- the temperature of the PM sensor 17 is set to 360 ° C. or higher to vaporize the intermediate product. If the failure determination of the filter 5 is performed thereafter, the detection value of the PM sensor 17 is not affected by the intermediate product, and therefore the accuracy of the failure determination is increased.
- step S106 when an affirmative determination is made in step S106, the process proceeds to step S105, and a failure determination of the filter 5 is performed. On the other hand, if a negative determination is made in step S106, the process proceeds to step S107, the temperature of the exhaust gas is further increased, and the process returns to step S106.
- the supply amount of the reducing agent is decreased as compared with the case where it is not performed, so that the reducing agent is prevented from adhering to the PM sensor 17. it can. For this reason, it can suppress that the precision of the detection value of PM sensor 17 falls by the reducing agent adhering to PM sensor 17. Therefore, the accuracy of the failure determination of the filter 5 can be increased.
- detection of the PM amount by the PM sensor 17 when the amount of NH 3 adsorbed by the NOx catalyst 7 is equal to or less than a predetermined amount may be started when the amount of NH 3 adsorbed by the NOx catalyst 7 is equal to or less than a predetermined amount.
- the detected value increases faster than when only PM adheres.
- the detection value of the PM sensor 17 may decrease due to the vaporization of the intermediate product attached to the PM sensor 17.
- the time when the detection value starts increasing is delayed.
- the NOx catalyst 7 adsorbs a lot of NH 3 , the progress of hydrolysis of urea becomes slow, so that the intermediate product passes through the NOx catalyst 7. Therefore, when the amount of NH 3 adsorbed by the NOx catalyst 7 is small, the detection value of the PM sensor 17 is hardly affected by the intermediate product. For example, if the failure determination of the filter 5 is performed after NH 3 is desorbed from the NOx catalyst 7 and before the amount of adsorption of NH 3 increases again, the determination accuracy is increased.
- the amount of NH 3 that can be adsorbed by the NOx catalyst 7 is limited.
- the upper limit value of the amount of NH 3 that can be adsorbed by the NOx catalyst 7 is hereinafter referred to as “upper limit adsorption amount”.
- the temperature of the NOx catalyst 7 becomes about 400 ° C., and NH 3 adsorbed by the NOx catalyst 7 is desorbed.
- the PM sensor 17 cannot detect the amount of PM unless a certain amount of PM adheres.
- the amount of NH 3 adsorbed by the NOx catalyst 7 reaches the upper limit adsorption amount before a certain amount of PM adheres to the PM sensor 17, the intermediate product passes through the NOx catalyst 7, The accuracy of the detection value of the PM sensor 17 is lowered.
- detection of the PM amount is started when the amount of NH 3 adsorbed by the NOx catalyst 7 is smaller than a predetermined amount.
- FIG. 9 is a time chart showing the transition of the amount of NH 3 adsorbed by the NOx catalyst 7 (NH 3 adsorption amount).
- FIG. 9 shows the transition of the NH 3 adsorption amount during the period indicated by D in FIG.
- FIG. 9 may be a time chart showing the transition of the NH 3 adsorption amount from the time point H when the PM amount can be detected by the PM sensor 17. That is, the time point indicated by H may be a time point when the PM sensor 17 can detect the PM amount.
- a time point indicated by J indicates a time point at which the failure determination of the filter 5 is performed.
- the difference between the detection value of the PM sensor 17 at the time point indicated by J and the detection value of the PM sensor 17 at the time point indicated by H is calculated as an integrated value of the PM amount in the period from H to J. .
- a failure determination of the filter 5 can be performed. Further, the failure determination of the filter 5 can be performed as described with reference to FIG. 4 at the same time point J in FIG. 9 and F in FIG.
- the solid line indicates a case where the amount of NH 3 adsorbed by the NOx catalyst 7 does not reach the upper limit adsorption amount at time J when the failure determination of the filter 5 is performed.
- the alternate long and short dash line indicates a case where the amount of NH 3 adsorbed by the NOx catalyst 7 exceeds the upper limit adsorption amount at the time J when the failure determination of the filter 5 is performed.
- the NOx catalyst 7 is adsorbed at the time indicated by H so that the NH 3 amount adsorbed by the NOx catalyst 7 at the time J when the failure determination of the filter 5 is performed does not reach the upper limit adsorption amount.
- the amount of NH 3 is set to a predetermined amount or less.
- NH 3 to NOx catalyst 7 is adsorbed Adjust the amount.
- This predetermined amount, NOx catalyst 7 can be the upper limit of the amount of NH 3 amount NH 3 adsorbed does not reach the upper limit adsorption amount when a point J to perform failure determination of the filter 5.
- the failure determination of the filter 5 may be performed after the condition for desorbing NH 3 from the NOx catalyst 7 is established.
- NH 3 is desorbed from the NOx catalyst 7, so that the amount of NH 3 adsorbed by the NOx catalyst 7 decreases.
- the filter 5 when the filter 5 is regenerated, the temperature of the NOx catalyst 7 rises to a temperature at which NH 3 is desorbed. Then, after the regeneration of the filter 5, the amount of NH 3 adsorbed by the NOx catalyst 7 is equal to or less than a predetermined amount.
- a process of removing NH 3 from the NOx catalyst 7 is periodically performed. At this time, NH 3 is desorbed from the NOx catalyst 7 by increasing the temperature of the NOx catalyst 7. Even after this, since the amount of NH 3 adsorbed by the NOx catalyst 7 is equal to or less than the predetermined amount, failure determination of the filter 5 may be performed at this time.
- the temperature of gas discharged from the internal combustion engine 1 is increased by performing post injection or increasing the amount of EGR gas, or the oxidation catalyst. 4 is supplied with HC. Further, the temperature of the filter 5 or the NOx catalyst 7 can be raised by supplying HC into the exhaust gas from the upstream side of the oxidation catalyst 4. After these controls are performed, the failure determination of the filter 5 can be performed.
- the amount of urea water supplied from the injection valve 6 is less than the amount required for the reduction of NOx in the exhaust, NH 3 adsorbed by the NOx catalyst 7 is consumed by the NOx in the exhaust and decreases. . Therefore, by reducing the amount of urea water supplied from the injection valve 6, the amount of NH 3 adsorbed by the NOx catalyst 7 may be reduced to a predetermined amount or less.
- the predetermined amount may be a specified value, but may be changed according to the degree of deterioration of the NOx catalyst 7.
- the upper limit adsorption amount decreases. That is, the amount of NH 3 adsorbed by the NOx catalyst 7 tends to exceed the upper limit adsorption amount. Therefore, the predetermined amount may be reduced as the degree of deterioration of the NOx catalyst 7 increases. That is, by reducing the adsorbed NH 3 amount at the time indicated by H in FIG. 9, to reduce the adsorbed NH 3 amount at the time represented by J in FIG.
- the predetermined amount may be set as follows.
- the NOx purification rate in the NOx catalyst 7 is calculated during the previous operation of the internal combustion engine 1, and the degree of deterioration of the NOx catalyst 7 is obtained from the NOx purification rate.
- the NOx purification rate can be calculated as the ratio of the NOx amount purified by the NOx catalyst 7 to the NOx amount flowing into the NOx catalyst 7. This NOx amount may be the NOx concentration.
- the amount of NOx purified by the NOx catalyst 7 can be calculated from the value obtained by subtracting the detection value of the second NOx sensor 16 from the detection value of the first NOx sensor 15.
- the NOx purification rate can be calculated by dividing the value obtained by subtracting the detection value of the second NOx sensor 16 from the detection value of the first NOx sensor 15 by the detection value of the first NOx sensor 15. Since the NOx purification rate and the degree of deterioration of the NOx catalyst 7 have a correlation, if this relationship is obtained in advance, the degree of deterioration can be obtained from the NOx purification rate.
- the upper limit value (upper limit adsorption amount) of the amount of NH 3 that can be adsorbed by the NOx catalyst 7 can be obtained from the degree of deterioration of the NOx catalyst 7. Since the degree of deterioration of the NOx catalyst 7 and the upper limit adsorption amount have a correlation, if this relationship is obtained in advance, the upper limit adsorption amount can be obtained from the degree of deterioration.
- the PM adhesion amount necessary for determining the failure of the filter 5 is hereinafter referred to as “necessary adhesion amount”.
- This required adhesion amount is determined by, for example, the specification of the PM sensor 17. Then, until the amount of PM adhering to the PM sensor 17 reaches the required amount of attachment, the predetermined amount is determined so that the amount of NH 3 adsorbed by the NOx catalyst 7 does not exceed the upper limit adsorption amount.
- the amount of NH 3 adsorbed by the NOx catalyst 7 changes according to the amount of NOx in the exhaust.
- the amount of NH 3 adsorbed by the NOx catalyst 7 at the time point J at which the failure determination of the filter 5 is performed changes in accordance with the total amount of NOx discharged from the internal combustion engine 1 in the period from H to J in FIG. .
- the load of the internal combustion engine 1 required until the PM amount adhering to the PM sensor 17 becomes the required adhesion amount is obtained.
- the amount of PM increases according to the load of the internal combustion engine 1. Therefore, the amount of PM discharged from the internal combustion engine 1 is calculated until the amount of PM attached to the PM sensor 17 reaches the required amount of attachment.
- the amount of PM discharged from the internal combustion engine 1 is obtained in advance by experiments or the like.
- the load of the internal combustion engine 1 corresponding to the amount of PM discharged from the internal combustion engine 1 is calculated. For example, this load may be obtained as the total amount of intake air.
- the relationship between the amount of PM discharged from the internal combustion engine 1 and the load on the internal combustion engine 1 is obtained in advance by experiments or the like.
- the total amount of intake air may be a specified value.
- the total amount of NOx discharged from the internal combustion engine 1 when the internal combustion engine 1 is operated with this load is calculated. Since the NOx amount discharged from the internal combustion engine 1 has a correlation with the operation state of the internal combustion engine 1, the total NOx amount can be calculated from the operation state of the internal combustion engine 1. Since urea water is supplied from the injection valve 6 according to the total NOx amount, there is a correlation between the total NOx amount and the urea water supply amount. If the NOx purification rate in the NOx catalyst 7 is taken into consideration, the amount of NH 3 consumed in the NOx catalyst 7 can be calculated. Furthermore, it is possible to calculate the supply amount of the urea water from the NH 3 amount and the consumed amount NH 3 to NOx catalyst 7 are adsorbed (hereinafter referred to. Total adsorption).
- the predetermined amount is determined so that (predetermined amount ⁇ upper limit adsorption amount ⁇ total adsorption amount). That is, the predetermined amount is determined so that the upper limit adsorption amount is not reached even if the total adsorption amount is added to the predetermined amount. Then, the amount of NH 3 adsorbed on the NOx catalyst 7 does not exceed the upper limit adsorption amount until the amount of PM adhering to the PM sensor 17 reaches the required amount of adhesion.
- FIG. 10 is a flowchart showing a flow for determining the failure of the filter 5 according to the present embodiment. This routine is executed by the ECU 10 every predetermined time.
- step S201 it is determined whether or not the regeneration process of the filter 5 has been performed. In this step, it is determined whether or not the amount of NH 3 adsorbed by the NOx catalyst 7 is sufficiently small. If NH 3 is not adsorbed on the NOx catalyst 7, it is after the regeneration processing of the filter 5 is performed.
- step S201 If an affirmative determination is made in step S201, the process proceeds to step S202. On the other hand, if a negative determination is made, the intermediate product may adhere to the PM sensor 17, so this routine is terminated.
- step S202 the upper limit adsorption amount is calculated.
- the upper limit value of the amount of NH 3 that can be adsorbed by the NOx catalyst 7 is calculated based on the NOx purification rate calculated during the previous operation.
- the NOx purification rate is stored in the ECU 10 every time the internal combustion engine 1 is operated. The relationship between the NOx purification rate and the upper limit adsorption amount may be obtained in advance through experiments or the like and stored in the ECU 10.
- step S203 the total adsorption amount is calculated. That is, based on the NOx purification rate and the urea water supply amount, the amount of NH 3 adsorbed by the NOx catalyst 7 at the time J when the failure determination of the filter 5 is performed is estimated. These relationships may be obtained in advance through experiments or the like, mapped, and stored in the ECU 10.
- step S204 a predetermined amount is calculated.
- a value obtained by subtracting a certain margin from the value obtained by subtracting the total adsorption amount from the upper limit adsorption amount is defined as a predetermined amount.
- step S205 it is determined whether the amount of PM deposited on the filter 5 is equal to or greater than a specified value.
- This specified value is set as a value that increases the accuracy of the failure determination of the filter 5. That is, immediately after the regeneration process of the filter 5 is performed, PM hardly passes through the filter 5 because PM hardly accumulates on the filter 5. For this reason, there is a possibility that the accuracy of the failure determination of the filter 5 may be lowered.
- step S205 If an affirmative determination is made in step S205, the process proceeds to step S206. On the other hand, if a negative determination is made, the process returns to step S202.
- step S206 it is determined whether or not the amount of NH 3 (actual adsorption amount) actually adsorbed by the NOx catalyst 7 is equal to or less than a predetermined amount. That is, it is determined whether the NH 3 amount adsorbed by the NOx catalyst 7 does not exceed the upper limit adsorption amount until the failure determination of the filter 5 is completed.
- step S206 If an affirmative determination is made in step S206, the process proceeds to step S207. On the other hand, if a negative determination is made, this routine is terminated because the accuracy of the failure determination of the filter 5 may be lowered.
- step S207 the OBD execution flag is turned ON.
- This OBD execution flag is a flag that is turned on when the failure determination of the filter 5 can be performed, and is turned off when it cannot be performed.
- step S208 failure determination of the filter 5 is performed. That is, it is determined whether or not the filter 5 has failed based on the detection value of the PM sensor 17.
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Abstract
Description
内燃機関の排気通路に設けられ供給される還元剤によりNOxを還元する選択還元型NOx触媒と、
前記選択還元型NOx触媒よりも上流側から還元剤として尿素水を供給する供給装置と、
前記選択還元型NOx触媒よりも下流側で排気中の粒子状物質の量を検出するPMセンサと、
前記PMセンサにより粒子状物質の量を検出するときには、前記PMセンサにより粒子状物質の量を検出しないときよりも、前記供給装置から供給される尿素水からアンモニアに至るまでの中間生成物の生成量を少なくする制御部と、
を備える。
2 吸気通路
3 排気通路
4 酸化触媒
5 フィルタ
6 噴射弁
7 選択還元型NOx触媒
10 ECU
11 エアフローメータ
12 第一排気温度センサ
13 第二排気温度センサ
14 第三排気温度センサ
15 第一NOxセンサ
16 第二NOxセンサ
17 PMセンサ
18 アクセル開度センサ
19 クランクポジションセンサ
Claims (5)
- 内燃機関の排気通路に設けられ供給される還元剤によりNOxを還元する選択還元型NOx触媒と、
前記選択還元型NOx触媒よりも上流側から還元剤として尿素水を供給する供給装置と、
前記選択還元型NOx触媒よりも下流側で排気中の粒子状物質の量を検出するPMセンサと、
前記PMセンサにより粒子状物質の量を検出するときには、前記PMセンサにより粒子状物質の量を検出しないときよりも、前記供給装置から供給される尿素水からアンモニアに至るまでの中間生成物の生成量を少なくする制御部と、
を備える内燃機関の排気浄化装置。 - 前記制御部は、前記PMセンサにより粒子状物質の量を検出するときには、前記PMセンサにより粒子状物質の量を検出しないときよりも、尿素水の供給量を少なくする請求項1に記載の内燃機関の排気浄化装置。
- 前記制御部は、尿素水の供給量を少なくする時間を、前記PMセンサにより粒子状物質の量の検出を開始する前の規定時間以下とする請求項2に記載の内燃機関の排気浄化装置。
- 前記PMセンサよりも上流の排気通路に設けられ排気中の粒子状物質を捕集するフィルタを備え、前記制御部は、前記フィルタの故障判定時に、前記中間生成物の生成量を少なくする請求項1から3の何れか1項に記載の内燃機関の排気浄化装置。
- 前記PMセンサによる粒子状物質の検出は、前記選択還元型NOx触媒が吸着しているアンモニアの量が所定量以下のときに開始し、該所定量は、前記内燃機関の前回の運転時において得た前記選択還元型NOx触媒の劣化の度合いに基づいて算出される該選択還元型NOx触媒が吸着可能なアンモニア量の上限値と、前記PMセンサによる粒子状物質の検出中に前記選択還元型NOx触媒が吸着するアンモニア量と、に基づいて算出される請求項1から4の何れか1項に記載の内燃機関の排気浄化装置。
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US14/345,985 US9234446B2 (en) | 2011-09-20 | 2011-09-20 | Exhaust gas purification apparatus for an internal combustion engine |
EP11872682.7A EP2759683B1 (en) | 2011-09-20 | 2011-09-20 | Exhaust gas purification apparatus for an internal combustion engine |
JP2013534476A JP5692397B2 (ja) | 2011-09-20 | 2011-09-20 | 内燃機関の排気浄化装置 |
PCT/JP2011/071347 WO2013042190A1 (ja) | 2011-09-20 | 2011-09-20 | 内燃機関の排気浄化装置 |
AU2011377324A AU2011377324B2 (en) | 2011-09-20 | 2011-09-20 | Exhaust gas purification apparatus for an internal combustion engine |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3032060A1 (en) | 2014-12-08 | 2016-06-15 | Toyota Jidosha Kabushiki Kaisha | Function diagnostic system for filter of internal combustion engine |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE112011105770B4 (de) * | 2011-10-26 | 2017-03-09 | Toyota Jidosha Kabushiki Kaisha | Regelungsvorrichtung für einen Verbrennungsmotor und Verfahren zum Steuern eines Verbrennungsmotors mit einer Regelungsvorrichtung |
US20160032802A1 (en) * | 2013-03-18 | 2016-02-04 | Yanmar Co., Ltd. | Exhaust purification system and ship comprising same |
JP6256391B2 (ja) * | 2015-03-13 | 2018-01-10 | トヨタ自動車株式会社 | 排気浄化システムの故障診断装置 |
JP7113598B2 (ja) * | 2017-07-14 | 2022-08-05 | 株式会社Soken | パティキュレートフィルタの故障検出装置及び故障検出方法 |
JP7003878B2 (ja) * | 2018-08-30 | 2022-01-21 | トヨタ自動車株式会社 | 内燃機関の排気浄化装置 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009085172A (ja) | 2007-10-02 | 2009-04-23 | Mitsubishi Fuso Truck & Bus Corp | 排気浄化装置 |
JP2011080439A (ja) * | 2009-10-09 | 2011-04-21 | Nippon Soken Inc | パティキュレートフィルタの異常検出装置 |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6947831B2 (en) * | 2003-04-11 | 2005-09-20 | Ford Global Technologies, Llc | Pressure sensor diagnosis via a computer |
JP4592505B2 (ja) * | 2005-06-09 | 2010-12-01 | 三菱ふそうトラック・バス株式会社 | 排気浄化装置 |
JP4592504B2 (ja) * | 2005-06-09 | 2010-12-01 | 三菱ふそうトラック・バス株式会社 | 排気浄化装置 |
US8051645B2 (en) * | 2007-12-18 | 2011-11-08 | Ford Global Technologies, Llc | Determination of diesel particulate filter load under both transient and steady state drive cycles |
US7926263B2 (en) * | 2007-12-20 | 2011-04-19 | GM Global Technology Operations LLC | Regeneration system and method for exhaust aftertreatment devices |
US7832200B2 (en) * | 2008-04-23 | 2010-11-16 | Caterpillar Inc | Exhaust system implementing feedforward and feedback control |
JP5251711B2 (ja) * | 2009-04-30 | 2013-07-31 | トヨタ自動車株式会社 | 内燃機関の排気浄化装置 |
US8631642B2 (en) * | 2009-12-22 | 2014-01-21 | Perkins Engines Company Limited | Regeneration assist calibration |
US8490476B2 (en) * | 2011-03-08 | 2013-07-23 | Ford Global Technologies, Llc | Method for diagnosing operation of a particulate matter sensor |
-
2011
- 2011-09-20 AU AU2011377324A patent/AU2011377324B2/en not_active Ceased
- 2011-09-20 US US14/345,985 patent/US9234446B2/en not_active Expired - Fee Related
- 2011-09-20 JP JP2013534476A patent/JP5692397B2/ja active Active
- 2011-09-20 EP EP11872682.7A patent/EP2759683B1/en not_active Not-in-force
- 2011-09-20 WO PCT/JP2011/071347 patent/WO2013042190A1/ja active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009085172A (ja) | 2007-10-02 | 2009-04-23 | Mitsubishi Fuso Truck & Bus Corp | 排気浄化装置 |
JP2011080439A (ja) * | 2009-10-09 | 2011-04-21 | Nippon Soken Inc | パティキュレートフィルタの異常検出装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2759683A4 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3032060A1 (en) | 2014-12-08 | 2016-06-15 | Toyota Jidosha Kabushiki Kaisha | Function diagnostic system for filter of internal combustion engine |
US10288592B2 (en) | 2014-12-08 | 2019-05-14 | Toyota Jidosha Kabushiki Kaisha | Function diagnostic system for filter of internal combustion engine |
Also Published As
Publication number | Publication date |
---|---|
EP2759683A1 (en) | 2014-07-30 |
AU2011377324B2 (en) | 2015-11-05 |
JP5692397B2 (ja) | 2015-04-01 |
AU2011377324A1 (en) | 2014-04-03 |
JPWO2013042190A1 (ja) | 2015-03-26 |
EP2759683A4 (en) | 2015-02-18 |
US20140230415A1 (en) | 2014-08-21 |
EP2759683B1 (en) | 2016-11-09 |
US9234446B2 (en) | 2016-01-12 |
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