Process for controlling the injection of urea in a selective catalytic reduction system
IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0739114
(2008-10-13)
|
등록번호 |
US-8505280
(2013-08-13)
|
우선권정보 |
FR-07 58531 (2007-10-23) |
국제출원번호 |
PCT/FR2008/051851
(2008-10-13)
|
§371/§102 date |
20100421
(20100421)
|
국제공개번호 |
WO2009/053638
(2009-04-30)
|
발명자
/ 주소 |
|
출원인 / 주소 |
- Peugeot Citroen Automobiles SA
|
대리인 / 주소 |
Polster Lieder Woodruff & Lucchesi, L.C.
|
인용정보 |
피인용 횟수 :
0 인용 특허 :
5 |
초록
▼
The invention relates to a process for controlling the injection of urea in a selective catalytic reduction, known as CR, system for treating nitrogen oxides, intended to be installed in the exhaust line (6) of a motor vehicle (1) engine (2), wherein the treatment comprises chemically reducing, in a
The invention relates to a process for controlling the injection of urea in a selective catalytic reduction, known as CR, system for treating nitrogen oxides, intended to be installed in the exhaust line (6) of a motor vehicle (1) engine (2), wherein the treatment comprises chemically reducing, in a catalyst (3), known as SCR catalyst, the nitrogen oxides by adding ammonia contained in urea, the process comprising the following steps: —the temperature of the gases in the exhaust line (6) of the engine (2), upstream of the SCR catalyst (3), is measured, —if the temperature measured is above a predetermined minimum value, called minimum injection temperature, an order is given to inject urea (5), —if the temperature measured is below the minimum injection temperature, the following substeps are carried out: —a mass of ammonia stored in the SCR catalyst (3) is determined, —the amount of ammonia required to obtain a nitrogen oxide conversion greater than a predetermined value is determined, if the mass of ammonia stored in the catalyst is below this required amount, an order is given to activate a method of heating the exhaust gases, and to inject urea into the system.
대표청구항
▼
1. A process for controlling the injection of urea for treatment of nitrogen oxides in a selective catalytic reduction system (SCR) intended to be installed in an exhaust line of an engine of an automotive vehicle, the treatment comprises chemically reducing in an SCR catalyst, nitrogen oxides by ad
1. A process for controlling the injection of urea for treatment of nitrogen oxides in a selective catalytic reduction system (SCR) intended to be installed in an exhaust line of an engine of an automotive vehicle, the treatment comprises chemically reducing in an SCR catalyst, nitrogen oxides by adding ammonia contained in urea; the process comprising the following steps: (a) first measuring of the temperature of the gases in the exhaust line of the engine, upstream of the SCR catalyst, then, after measuring the temperature of the gases:(b) injecting urea into the exhaust line if the measured temperature is greater than a predetermined minimum injection temperature,(c) performing steps (c)(i)-(c)(v) if the measured temperature is lower than the minimum injection temperature: (i) determining the quantity of ammonia (Qs) stored in the SCR catalyst,(ii) determining a nitrogen oxide conversion efficiency;(iii) determining the quantity of ammonia (Qn) necessary for obtaining a conversion of nitrogen oxides greater than said conversion efficiency,(iv) comparing the quantity of ammonia (Qs) stored in the SCR catalyst with the quantity of ammonia (Qn) determined in step (c)(iii) necessary for obtaining the conversion of nitrogen oxides greater than said conversion efficiency; and(v) activating a heating mode of the exhaust gases and injecting urea into the system if the quantity of ammonia (Qs) stored in the catalyst is less than the quantity of ammonia (Qn) necessary to obtain the conversion of nitrogen oxides greater than said conversion efficiency. 2. The process according to claim 1, in which the minimum injection temperature is set at 180° C. 3. The process according to claim 2 further comprising the following steps: determining the maximum quantity of ammonia that can be stored in the SCR catalyst,continuously measuring the quantity of ammonia stored in the catalyst, andif the exhaust gas heating mode is activated when the stored quantity reaches the maximum quantity, deactivating the heating mode. 4. The process according to claim 3, in which the maximum quantity of ammonia corresponds with a quantity above which desorption of ammonia takes place. 5. The process according to claim 3, in which the step of commanding activating and/or deactivating the heating mode comprises modifying at least one engine parameter having an influence on the temperature of the exhaust gases. 6. The process according to claim 5, in which the engine parameter is a circulation rate of the exhaust gases, a fuel injection phase or a quantity of injected fuel.
이 특허에 인용된 특허 (5)
-
Hammerle Robert Henry ; Adams Karen Marie ; Laing Paul Matthew, Emission control system.
-
Solbrig, Charles E., Excess NH3 storage control for SCR catalysts.
-
Upadhyay,Devesh; van Nieuwstadt,Michiel J., Exhaust gas aftertreatment systems.
-
Schmelz Helmut (Prien DEX), Method and apparatus for controlled introduction of a reducing agent into a nitrogen oxide-containing exhaust gas.
-
Schoubye Peter,DKX, Process for selective reduction of NOx in exhaust gas.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.