Method for minimizing ammonia slip from SCR catalysts
원문보기
IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0523054
(2012-06-14)
|
등록번호 |
US-8820050
(2014-09-02)
|
우선권정보 |
EP-11172069 (2011-06-30) |
발명자
/ 주소 |
- Dubkov, Alexey A.
- Balenovic, Mario
- Harmsen, Jan
- Ukropec, Robert
- Carberry, Brendan Patrick
|
출원인 / 주소 |
- Ford Global Technologies, LLC
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대리인 / 주소 |
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인용정보 |
피인용 횟수 :
1 인용 특허 :
8 |
초록
▼
Embodiments for reducing ammonia slip are provided. In one example, a method for reduction of ammonia emissions from an engine exhaust gas aftertreatment device with an SCR catalyst comprises determining a concentration of NOx and/or ammonia in the exhaust gas aftertreatment device, comparing a dete
Embodiments for reducing ammonia slip are provided. In one example, a method for reduction of ammonia emissions from an engine exhaust gas aftertreatment device with an SCR catalyst comprises determining a concentration of NOx and/or ammonia in the exhaust gas aftertreatment device, comparing a determined value of NOx and/or ammonia concentration with a nominal value for NOx and ammonia, respectively, and if an actual or shortly forecasted ammonia concentration is above the respective nominal value, triggering engine conditions with higher exhaust NOx concentration. In this way, ammonia slip may be reduced without degrading fuel economy.
대표청구항
▼
1. An engine method, comprising: in response to ammonia slip past an SCR catalyst during designated conditions, if an EGR amount is above a threshold, increasing engine-out NOx emissions by first decreasing the EGR amount;if ammonia slip is still detected upon reduction of the EGR amount, then incre
1. An engine method, comprising: in response to ammonia slip past an SCR catalyst during designated conditions, if an EGR amount is above a threshold, increasing engine-out NOx emissions by first decreasing the EGR amount;if ammonia slip is still detected upon reduction of the EGR amount, then increasing engine-out NOx emissions by adjusting fuel injection timing and/or quantity; andif the EGR amount is above the threshold and if ammonia slip is detected following the adjustment in fuel injection timing and/or quantity, then increasing engine-out NOx emissions by adjusting boost pressure. 2. The engine method of claim 1, wherein the EGR amount is decreased based on feedback from an ammonia sensor positioned downstream of the SCR catalyst. 3. The engine method of claim 1, wherein the EGR amount is decreased by a level that maintains tailpipe NOx emissions below a threshold. 4. The engine method of claim 1, further comprising if the EGR amount is below the threshold, increasing engine-out NOx emissions by adjusting fuel injection timing and/or quantity. 5. The engine method of claim 1, wherein the ammonia slip is estimated based on exhaust gas temperature, exhaust mass flow, NOx levels, and reductant injection amount. 6. The engine method of claim 1, wherein the designated conditions comprise a load on a particulate filter being below a threshold, the method further comprising if the designated conditions are not met, not increasing engine-out NOx emissions. 7. An engine method, comprising: in response to ammonia slip past an SCR catalyst while an EGR amount is above a threshold: first increasing engine-out NOx emissions by first decreasing the EGR amount and if ammonia slip is still detected upon reduction of the EGR amount, second increasing engine-out NOx emissions by adjusting fuel injection timing and/or quantity; and thenif ammonia slip is still detected, then third increasing engine-out NOx emissions by adjusting boost pressure. 8. The engine method of claim 7, wherein the EGR amount is decreased based on feedback from an ammonia sensor positioned downstream of the SCR catalyst. 9. The engine method of claim 7, wherein the EGR amount is decreased by a level that maintains tailpipe NOx emissions below a threshold. 10. The engine method of claim 7, wherein the ammonia slip is estimated based on exhaust gas temperature, exhaust mass flow, NOx levels, and reductant injection amount. 11. The engine method of claim 7, wherein while the EGR amount is above the threshold, a load on a particulate filter is below a threshold.
이 특허에 인용된 특허 (8)
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Caudle, Matthew T.; Deiterle, Martin; Roth, Stanley A.; Xue, Wen-Mei, Bifunctional catalysts for selective ammonia oxidation.
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Funk,Werner; Roberts,Phillip, Emission control system.
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Stewart, Gregory E.; Germann, David, Measurement of NO and NOfor control of selective catalytic reduction.
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Schmelz Helmut (Prien DEX), Method and apparatus for controlled introduction of a reducing agent into a nitrogen oxide-containing exhaust gas.
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Dolling Winfried,DEX, Method and device for converting a pollutant in an exhaust gas in a catalytic converter.
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Minkara, Rafic Y., Method and system for reducing ammonia slip after selective reduction of NOx.
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Gabrielsson,P?r; Gekas,Ioannis; Thorhauge,Max, Method for controlling injection of reducing agent in exhaust gas from a combustion engine.
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Emmerling Gerhard,DEX ; Zuther Frank,DEX ; Doring Andreas,DEX, Method for metering a reducing agent into NO.sub.x -containing exhaust gas of an internal combustion engine.
이 특허를 인용한 특허 (1)
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Singh, Nishant, Reductant dosing control using prediction of exhaust species in selective catalytic reduction.
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