EP1270911B1 - Dispositif d'épuration de gaz d'échappement avec un piège à NOx - Google Patents

Dispositif d'épuration de gaz d'échappement avec un piège à NOx Download PDF

Info

Publication number
EP1270911B1
EP1270911B1 EP20010115558 EP01115558A EP1270911B1 EP 1270911 B1 EP1270911 B1 EP 1270911B1 EP 20010115558 EP20010115558 EP 20010115558 EP 01115558 A EP01115558 A EP 01115558A EP 1270911 B1 EP1270911 B1 EP 1270911B1
Authority
EP
European Patent Office
Prior art keywords
nox
nitrogen oxides
reduction catalyst
absorption
exhaust gas
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP20010115558
Other languages
German (de)
English (en)
Other versions
EP1270911A1 (fr
Inventor
Keiji Shimotani
Hiroshi Tsunoda
Hiroyuki Ysamada
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Isuzu Motors Ltd
Original Assignee
Isuzu Motors Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Isuzu Motors Ltd filed Critical Isuzu Motors Ltd
Priority to EP20010115558 priority Critical patent/EP1270911B1/fr
Priority to DE2001616278 priority patent/DE60116278T2/de
Publication of EP1270911A1 publication Critical patent/EP1270911A1/fr
Application granted granted Critical
Publication of EP1270911B1 publication Critical patent/EP1270911B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
    • F01N3/0842—Nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/021—Introducing corrections for particular conditions exterior to the engine
    • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
    • F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
    • F02D41/0275—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a NOx trap or adsorbent
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/021—Introducing corrections for particular conditions exterior to the engine
    • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
    • F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
    • F02D41/0275—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a NOx trap or adsorbent
    • F02D41/028—Desulfurisation of NOx traps or adsorbent
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/146—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/146—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration
    • F02D41/1461—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration of the exhaust gases emitted by the engine
    • F02D41/1462—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration of the exhaust gases emitted by the engine with determination means using an estimation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/146—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration
    • F02D41/1463—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration of the exhaust gases downstream of exhaust gas treatment apparatus
    • 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
    • F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
    • F01N2570/04—Sulfur or sulfur oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2200/00—Input parameters for engine control
    • F02D2200/02—Input parameters for engine control the parameters being related to the engine
    • F02D2200/08—Exhaust gas treatment apparatus parameters
    • F02D2200/0806—NOx storage amount, i.e. amount of NOx stored on NOx trap
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
    • F02D41/1402—Adaptive control

Definitions

  • the present invention relates to an exhaust gas purifying facility with a nitrogen oxides absorption-reduction catalyst (hereinafter referred to as NOx absorption-reduction catalyst) for purifying nitrogen oxides (NOx) in exhaust gas by absorbing NOx when the air/fuel ratio of exhaust gas of the internal combustion engine is lean, and by discharging and reducing NOx when it is rich.
  • NOx absorption-reduction catalyst nitrogen oxides absorption-reduction catalyst for purifying nitrogen oxides (NOx) in exhaust gas by absorbing NOx when the air/fuel ratio of exhaust gas of the internal combustion engine is lean, and by discharging and reducing NOx when it is rich.
  • the present invention relates to an exhaust gas purifying facility that may be applied to all the lean burn vehicles and is provided with an NOx absorption-reduction catalyst and an NOx sensor so that NOx absorption-reduction catalyst can be regenerated every appropriate period of time while using the detected value of the NOx sensor for the operation of an engine employing a lean-burn system.
  • an NOx absorption-reduction catalyst in which NOx is absorbed in basic element such as barium (Ba) or the like in the region of lean air/fuel ratio and then the absorbed NOx is desorped (discharged) and reduced in the region of rich air/fuel ratio has developed recently and already commercialized.
  • the NOx absorption-reduction catalyst 2 is formed in such a manner that a catalytic active metal 3 and a NOx absorbing substance (R) 4 having NOx absorbing feature are supported on the supporting layer 5 formed on the support 6.
  • the supporting layer 5 is formed of a porous coating material such as porous zeolite or alumina (Al 2 O 3 ), or the like.
  • the catalytic active metal 3 is formed of platinum (Pt) having an oxidation catalytic capability.
  • NOx absorbing substance (R) 4 is formed of potassium (K), barium (Ba), lanthanum (La) or the like.
  • the NOx absorption-reduction catalyst 2 absorbs NOx and discharges and purifies NOx depending on the concentration of oxygen in exhaust gas, or the concentration of carbon monoxide. In other words, the NOx absorption-reduction catalyst 2 exercises two features of absorption of NOx, and discharge and purification of NOx.
  • the NOx absorption-reduction catalyst 2 uses its oxidation feature of catalytic metal 3 such as platinum to oxidize nitric monoxide (NO) in exhaust gas into nitrogen dioxide (NO 2 ) by oxygen in exhaust gas as shown in Fig. 4 (a) under the operation of lean air/fuel ratio in which oxygen (O 2 ) is contained in exhaust gas as in the case of normal diesel engines or lean-burn gasoline engine, and the like.
  • the nitrogen dioxide reacts with barium 4 or the like, which is a NOx absorbing substance, to form nitrate (for example Ba(NO 3 ) 2 and the like) for absorption. Occlusion of nitrogen dioxide purifies NOx in exhaust gas.
  • the operating condition of the engine is changed into a rich spike that generates exhaust gas called a rich spike gas to deliver the rich spike gas to the NOx absorption-reduction catalyst 2.
  • the rich spike gas is exhaust gas of high temperature generated in rich air/fuel ratio (the theoretical air/fuel ratio or an air/fuel ratio close to the theoretical air/fuel ratio) operation in which the concentration of oxygen (O 2 ) contained therein is close to zero.
  • the control apparatus of the computer for controlling the engine called ECM is used for controlling a rich spike according to the control flow shown in Fig. 5.
  • concentration of NOx at each moment is calculated from entered load and the number of revolutions by the use of NOx concentration map that is entered in advance.
  • emission of NOx (NOxc) for each operating condition of the engine is calculated by the use of calculated NOx concentration and entered intake air mass (Q), and then the emission of NOx (NOxc) is integrated.
  • NOxmass reaches a prescribed threshold value (first reference value: NOxSL)
  • a rich spike is executed.
  • control is carried out with the prescribed threshold value (first reference value: NOxSL) fixed despite of the fact that the NOx absorbing capability of the catalyst is lowered with deterioration of the catalyst over time. Therefore, there is a problem in that a rich spike cannot be executed at the moment most suitable for recovering the NOx absorbing capability.
  • the NOx absorption-reduction catalyst is susceptible to deterioration due to sulfur poisoning, which may lower the NOx absorbing capability of the catalyst. Therefore, when a rich spike is executed according to the normal control of a rich spike, fuel consumption may be deteriorated.
  • the progress of deterioration of the catalyst by sulfur poisoning varies depending on the description of the fuel or the history of the operation of the engine. Therefore, in order to know the degree of deterioration of the catalyst, it is required to monitor the state of deterioration of the catalyst.
  • an object of the present invention to provide an exhaust gas purifying apparatus comprising a nitrogen oxides absorption-reduction catalyst for absorbing, as well as reducing and purifying NOx in exhaust gas, wherein the value detected by the NOx sensor is used to monitor the variations in NOx absorbing capability (the amount that can be absorbed) with deterioration of the catalyst, so that a rich spike can be introduced at appropriate moments and the purifying performance with respect to NOx in exhaust gas can be improved outstandingly as a whole.
  • the exhaust gas purifying apparatus including a nitrogen oxides absorption-reduction catalyst for achieving the objects described above comprises a nitrogen oxides absorbing substance disposed in the exhaust passage of the internal combustion engine for absorbing nitrogen oxides when the air/fuel ratio is lean and discharging nitrogen oxides when the air/fuel ratio is theoretical air/fuel ratio or rich, and a precious metal catalyst, and a control apparatus for computing the integrated value of NOx from the engine load, the number of revolutions of the engine, and the intake air mass, so that a rich spike is executed when the integrated value of NOx exceeds the predetermined first reference value, characterized in that a NOx sensor is provided downstream from the nitrogen oxides absorption-reduction catalyst, and in that the control apparatus corrects the predetermined first reference value when the value detected by the NOx sensor immediately after the rich spike is executed exceeds the predetermined second reference value.
  • the rich spike is a special operational control of the engine in which the air/fuel ratio is temporarily shifted to rich side to supply exhaust gas of low oxygen concentration for discharging and reducing NOx to regenerate the NOx absorbing capability.
  • the rich spike is executed for one to two seconds of period before the amount of the NOx absorption is saturated.
  • an NOx sensor for detecting the concentration of NOx is mounted immediately downstream of the NOx absorption-reduction catalyst to monitor the state of deterioration of the catalyst from the concentration of NOx after the NOx absorption-reduction catalyst has passed.
  • the slice level which is the first reference value with respect to the integrated value of the NOx emission for determining whether or not a rich spike is to be introduced, may be changed according to the NOx absorbing capability (the amount that can be absorbed) by the used of the measured value of the NOx concentration.
  • the frequency of the introduction (occurrence) of the lowering of the NOx absorbing capability may be increased, and the rich spike can be introduced at appropriate moments.
  • a rich spike can be executed at appropriate moments by correcting the first reference value for determining the timing of the introduction of a rich spike according to the NOx absorbing capability.
  • the exhaust gas purifying apparatus including the nitrogen oxides absorption-reduction catalyst is constructed in such a manner that the control apparatus performs the operation in regeneration mode in the rich air/fuel ratio when the predetermined first reference value is smaller than the predetermined third reference value.
  • the operation in regeneration mode refer to an operation for regenerating the NOx absorbing capability of the NOx absorption-reduction catalyst, in which the operation of theoretical air/fuel ratio is continuously executed, for example, for 10 to 30 minutes with the lean-burn operation prohibited.
  • the operation in regeneration mode can be introduced appropriately using the first reference value that is to be corrected according to the NOx absorbing capability as a criterion for assessment of the introduction of the operation in regeneration mode.
  • the exhaust gas purifying apparatus including a nitrogen oxides absorption-reduction catalyst is constructed in such a manner that the control apparatus determines that the nitrogen oxides absorption-reduction catalyst is in the abnormal state when the value detected by the NOx sensor immediately after executing the operation in regeneration mode exceeds the predetermined fourth reference value.
  • the abnormality of the NOx absorption-reduction catalyst can be determined, thereby urging the operator an appropriate countermeasure.
  • the NOx absorbing capability of the nitrogen oxides absorption-reduction catalyst can be figured out, and thus the NOx purification rate can always be maintained at a high level. Since the number of the introductions of the rich spike may be maintained at low as possible, the deterioration of fuel consumption may be prevented.
  • an exhaust gas purifying apparatus 1 having a nitrogen oxides absorption-reduction catalyst (NOx absorption-reduction catalyst) is disposed in the discharge passage 11 of the internal combustion engine E.
  • NOx absorption-reduction catalyst 2 a nitrogen oxides absorption-reduction catalyst for detecting the NOx concentration of purified exhaust gas Gc after it has passed through the NOx absorption-reduction catalyst 2.
  • the NOx absorption-reduction catalyst 2 comprises a support 6, a supporting layer 5 formed on the support 6, a catalyst metal 3 supported by the supporting layer 5, an NOx absorbing substance 4 that absorbs nitrogen oxides (NOx) when the air/fuel ratio is lean and discharges the nitrogen oxides when the air/fuel ratio is rich.
  • the supporting layer 5 is a catalyst support formed of a porous coating material such as alumina or the like.
  • the catalyst metal 3 is formed of platinum (Pt) or the like having a reduction activity in the temperature region higher than the light on temperature, other catalyst metal may be used.
  • the light on temperature is in the region about 150 °C - 200 °C.
  • Nox absorbing substances 4 barium (Ba), calcium (Ca) and the like may be employed. When barium is employed, the temperature for starting discharge of Nox is in the vicinity of 450 °C.
  • the NOx absorbing substance 4 may be, as shown in Fig. 4, supported by the catalyst support 5, but it is also possible to form the catalyst support 5 of the NOx absorbing substance 4 instead.
  • the exhaust gas purifying apparatus having the NOx absorption-reduction catalyst of the present invention is constructed in such a manner that the rich spike introduction control and the regeneration mode introduction control as described below are executed.
  • the rich spike introduction control according to the present invention is executed according to the control flow chart exemplified in Fig. 2.
  • the rich spike is the operation of engine in which the air/fuel ratio is temporarily shifted to the rich side before the amount of NOx absorption is saturated to supply exhaust gas of low oxygen concentration, so that NOx is discharged and reduced to regenerate the NOx absorption capability.
  • the control flow is to be executed concurrently with the control of the engine operation, which starts with the commencement of the engine operation control, and is interrupted when the engine operation control stops, the control flow is interrupted in mid course thereof, and then proceeds to stop and ends.
  • the intake air mass Q entered in Step S13 and the calculated NOx concentration are used in Step S14 to calculate the NOx emission for every state of engine operation NOxc, and then integrated to obtain the integrated value of NOx (Integrated amount: NOxmass) in Step S15.
  • the integrated value NOxmass at that moment is stored, and the stored value is used as a base of integration for the next start.
  • Step 16 whether or not the integrated value NOxmass of the NOx reaches the predetermined first reference value NOxSL is determined.
  • a rich spike start signal is supplied in Step S17 to introduce a rich spike.
  • step S16 When the integrated value NOxmass of the NOx does not reach the predetermined first reference value NOxSL (NO) in step S16, the time period between measuring times is counted by the timer A, and after this counted time period is elapsed, the flow returns to the step S11 and repeats Steps S11-S16.
  • the rich spike time period is counted by the timer B, and after the counted time period is elapsed, the NOx concentration immediately after the rich spike terminates is measured by the NOx sensor 13 disposed immediately downstream from the catalyst 2 in Step S21.
  • the NOx concentration RSNOx immediately after the rich spike terminates is compared with the predetermined second reference value RSSL to detect the state of deterioration of the catalyst (RSNOx>RSSL) in Step S22, and when it is in the deteriorated state (RSNOx>RSSL) (YES), the slice level NOxSL, which is the first reference value, is corrected in Step S23.
  • This correction is executed by multiplying the slice level NOxSL of the previous time by a coefficient KNOX (KNOX ⁇ 1).
  • Step S22 When the catalyst 2 is not in the deteriorated state (RSNOx>RSSL) (NO) in Step S22, the integrated value NOxmass of NOx is initialized in Step S24 to repeat the control.
  • the integrated value NOxmass of NOx is computed from the engine load, the number of revolutions of the engine, and the intake air mass Q, and when the integrated value NOxmass of NOx exceeds the predetermined first reference value NOxSL, the control to execute a rich spike is enabled, and when the value detected by the NOx sensor RSNOx obtained immediately after execution of a rich spike exceeds the predetermined second reference value RSSL, the predetermined first reference value NOxSL may be corrected.
  • the regeneration mode operation is for regenerating the NOx absorption capability of the NOx absorption-reduction catalyst, and continues the operation prohibiting the lean-burn operation for a predetermined time period (for example, about 10-30 minutes).
  • the regeneration mode operation is for dealing with deterioration of the fuel consumption caused by frequent introduction of a rich spike according to the above-described rich spike introduction control when the NOx absorbing capability of the catalyst is reduced due to progress of sulfur poisoning as a result of long-term operation.
  • This flow is called and executed repeatedly in conjunction with appropriate time intervals or a specific step of the above-described rich spike introduction control (for example, immediately after Step S23).
  • Step S31 the slice level NOxSL, which is the predetermined first reference value, is checked in Step S31.
  • the slice level NOxSL exceeds the predetermined third reference value RGSL (NO)
  • the regeneration mode operation is determined to be unnecessary, and thus the flow proceeds to return.
  • the slice level NOxSL is smaller than the predetermined third reference value RGSL (YES)
  • the regeneration mode operation is determined to be necessary, and thus a signal of regeneration mode ON is supplied to regenerate the NOx absorption-reduction catalyst in Step S32.
  • This regeneration mode operation counts the time period immediately after turning ON by the timer, and terminates when the regeneration mode operation is executed for the predetermined time period.
  • Step S43 When the time period of the regeneration mode operation is counted by the timer C in Step S43, and after the time period is elapsed, the NOx concentration RSNOx on the downstream from the catalyst is measured immediately after the regeneration mode terminates in Step S33, and when the NOx concentration RSNOx is lower than the predetermined fourth reference value RSSL2 (YES) and thus it is determined that the regeneration of the catalyst is completed in Step S34, the slice level NOxSL for checking the NOx integrated value is initialized to reset the slice level NOxSL to the initial value NOxSL0 in Step S36, and the flow proceeds to return.
  • RSSL2 predetermined fourth reference value
  • Step S34 shows that the NOx concentration RSNOx downstream of the catalyst immediately after the regeneration mode terminates exceeds the predetermined fourth reference value RSSL2, the recovery of the NOx purification rate of the catalyst cannot be observed even in the regeneration mode.
  • it is determined to be abnormal catalyst which is the case where the catalyst is deteriorated by the cause other than sulfur poisoning, and the flow proceeds to Step S35 in which the deterioration of the catalyst is diagnosed, and the engine check lamp is turned on, and then returns.
  • the state of deterioration of the catalyst 2 can be monitored by the NOx concentration RSNOx measured by the NOx sensor 13, so that the first reference value NOxSL with respect to the integrated value NOxmass of the NOx emission for determining whether or not the introduction of a rich spike is possible may be varied according to the NOx absorption capability at the moment.
  • the frequency of the introduction of a rich spike may be increased with lowering of the NOx absorption capability, and thus a rich spike can be introduced at appropriate moments.
  • the first reference value NOxSL to be corrected according to the NOx absorption capability is used as a criterion for assessment of the introduction of the operation in regeneration mode, so that the introduction of the operation in regeneration mode can be executed appropriately.
  • the NOx absorption capability of the nitrogen oxides absorption-reduction catalyst 2 can be figured out, and thus the NOx purification rate can always be maintained at a high level. Since the number of the introductions of the rich spike may be maintained as low as possible, the deterioration of fuel consumption may be prevented.

Claims (3)

  1. Un appareil de purification de gaz d'échappement 1 ayant un catalyseur d'absorption-de réduction d'oxydes d'azote comportant :
    un catalyseur d'absorption-de réduction d'oxydes d'azote (2) ayant une substance absorbante d'oxydes d'azote (4) prévue dans le passage pour échappement (11) du moteur à combustion interne (E) pour absorber des oxydes d'azote lorsque le rapport air/carburant est pauvre et décharger des oxydes d'azote lorsque le rapport air/carburant est le rapport air/carburant théorique ou riche, et un catalyseur de métal précieux (3) ; et
    un appareil de contrôle (10) pour calculer la valeur intégrée de NOx (masseNOx) d'après la charge au moteur, le nombre de tours du moteur, et la masse d'air en entrée, de sorte qu'une pointe riche est exécutée lorsque la valeur intégrée de NOx (masseNOx) dépasse la première valeur de référence prédéterminée (NOxSL) ;
    caractérisé en ce qu'un capteur de NOx (13) est prévu en aval du catalyseur d'absorption-de réduction d'oxydes d'azote (2), et en ce que l'appareil de contrôle 10 corrige la première valeur de référence prédéterminée (NOxSL) lorsque la valeur détectée par le capteur de NOx (13) (RSNOx) immédiatement après exécution de la pointe riche dépasse une deuxième valeur de référence prédéterminée (RSSL).
  2. Un appareil de purification de gaz d'échappement ayant un catalyseur d'absorption-de réduction d'oxydes d'azote tel qu'énoncé dans la revendication 1, caractérisé en ce que l'appareil de contrôle (10) effectue l'opération en mode régénération dans le rapport riche air/carburant lorsque la première valeur de référence prédéterminée (NOxSL) est plus petite que la troisième valeur de référence prédéterminée (RGSL).
  3. Un appareil de purification de gaz d'échappement ayant un catalyseur d'absorption-de réduction d'oxydes d'azote tel qu'énoncé dans la revendication 2, caractérisé en ce que l'appareil de contrôle (10) détermine que le catalyseur d'absorption-de réduction d'oxydes d'azote (2) est dans l'état anormal lorsque la valeur détectée par le capteur de NOx (13) (RSNOx) immédiatement après avoir exécuté l'opération en mode régénération dépasse la quatrième valeur de référence prédéterminée (RSSL2).
EP20010115558 2001-06-28 2001-06-28 Dispositif d'épuration de gaz d'échappement avec un piège à NOx Expired - Lifetime EP1270911B1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP20010115558 EP1270911B1 (fr) 2001-06-28 2001-06-28 Dispositif d'épuration de gaz d'échappement avec un piège à NOx
DE2001616278 DE60116278T2 (de) 2001-06-28 2001-06-28 Vorrichtung zur Reinigung des Abgases mit einem Stickoxidfallekatalysator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP20010115558 EP1270911B1 (fr) 2001-06-28 2001-06-28 Dispositif d'épuration de gaz d'échappement avec un piège à NOx

Publications (2)

Publication Number Publication Date
EP1270911A1 EP1270911A1 (fr) 2003-01-02
EP1270911B1 true EP1270911B1 (fr) 2005-12-28

Family

ID=8177850

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20010115558 Expired - Lifetime EP1270911B1 (fr) 2001-06-28 2001-06-28 Dispositif d'épuration de gaz d'échappement avec un piège à NOx

Country Status (2)

Country Link
EP (1) EP1270911B1 (fr)
DE (1) DE60116278T2 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4232524B2 (ja) * 2003-04-25 2009-03-04 株式会社日立製作所 エンジンの制御装置
DE102017222253B4 (de) 2017-03-28 2023-09-21 Ford Global Technologies, Llc Verfahren zum Betrieb einer Abgasnachbehandlungsvorrichtung eines Kraftfahrzeugs
CN112412599B (zh) * 2020-11-18 2022-04-05 潍柴动力股份有限公司 上游NOx传感器故障识别方法、装置、车辆及存储介质
CN114263521B (zh) * 2021-12-31 2023-03-21 潍柴动力股份有限公司 一种传感器参数的修正方法及装置

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5437153A (en) * 1992-06-12 1995-08-01 Toyota Jidosha Kabushiki Kaisha Exhaust purification device of internal combustion engine
JP2836522B2 (ja) * 1995-03-24 1998-12-14 トヨタ自動車株式会社 内燃機関の排気浄化装置
DE69825813T2 (de) * 1997-03-21 2005-02-03 NGK Spark Plug Co., Ltd., Nagoya Verfahren und Vorrichtung zur Messung einer NOx-Gaskonzentration
EP0940570B1 (fr) * 1998-01-09 2001-08-22 Ford Global Technologies, Inc. Procédé de régénération d'un piège à oxydes d'azote dans le système d' échappement d' un moteur à combustion interne avec prise en compte du débit massique de gaz d' échappement
FR2792033B1 (fr) * 1999-04-12 2001-06-01 Renault Procede et dispositif de diagnostic de l'etat de fonctionnement d'un pot catalytique de traitement des gaz d'echappement d'un moteur a combustion interne
DE19922981A1 (de) * 1999-05-19 2000-11-30 Bosch Gmbh Robert Verfahren zur Kontrolle der Funktionstüchtigkeit eines NO¶x¶-Speicherkatalysators
DE19923498A1 (de) * 1999-05-21 2000-11-23 Volkswagen Ag Verfahren zur Steuerung einer Regeneration eines NOx-Speicherkatalysators

Also Published As

Publication number Publication date
EP1270911A1 (fr) 2003-01-02
DE60116278T2 (de) 2006-08-03
DE60116278D1 (de) 2006-02-02

Similar Documents

Publication Publication Date Title
US6460329B2 (en) Exhaust gas purifying facility with nitrogen oxides absorption-reduction catalyst
US7111451B2 (en) NOx adsorber diagnostics and automotive exhaust control system utilizing the same
US9816415B2 (en) Control apparatus for an internal combustion engine
JP3744483B2 (ja) 内燃機関の排気浄化装置
US6629408B1 (en) Exhaust emission control system for internal combustion engine
JP3901194B2 (ja) 排気ガス浄化方法及び排気ガス浄化システム
US6843240B1 (en) Method for monitoring the functioning of a NOx sensor arranged in an exhaust gas channel of an internal combustion engine
KR101418192B1 (ko) 내연 기관의 배기 정화 장치
JP6278039B2 (ja) 選択還元型触媒の劣化診断装置
JP5035263B2 (ja) 内燃機関の排気浄化装置
US6484493B2 (en) Exhaust emission control device for internal combustion engine
JP7169826B2 (ja) 触媒劣化診断システムおよび触媒劣化診断方法
EP1270911B1 (fr) Dispositif d'épuration de gaz d'échappement avec un piège à NOx
JP4345484B2 (ja) 排気ガス浄化方法及び排気ガス浄化システム
US7219008B2 (en) Method and device for estimating a nitrogen oxide mass stored in a catalytic trapping device of a motor vehicle
JP3552603B2 (ja) 内燃機関の排気浄化装置
JP2003502554A5 (fr)
JP4093302B2 (ja) ＮＯｘ浄化システムの触媒劣化判定方法及びＮＯｘ浄化システム
JP4075641B2 (ja) 内燃機関の排気ガス浄化システム
JP4479141B2 (ja) エンジンの排気浄化装置及び排気浄化方法
JP4406412B2 (ja) 窒素酸化物吸着触媒の再生を開始するための方法と装置
JP3460530B2 (ja) 内燃機関の排気浄化装置
JP2004232576A (ja) 内燃機関の排気浄化装置
WO2006027905A1 (fr) Méthode et système de gestion de système de purification de gaz d’échappement
JP3446646B2 (ja) 内燃機関の排気浄化装置

Legal Events

Date Code Title Description
EUG Se: european patent has lapsed
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20030403

AKX Designation fees paid

Designated state(s): DE FR GB IT SE

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT SE

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REF Corresponds to:

Ref document number: 60116278

Country of ref document: DE

Date of ref document: 20060202

Kind code of ref document: P

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20060315

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20060404

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20060607

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20060630

Year of fee payment: 6

ET Fr: translation filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20060817

Year of fee payment: 6

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20060929

EUG Se: european patent has lapsed
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20070628

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20080229

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080101

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070628

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070629

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070702

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070628