METHOD FOR DETERMINING THE TRUE AMOUNT OF AN ACTIVE PRODUCT ENTERING A CATALYTIC DEVICE OF AN EXHAUST LINE OF A VEHICLE

• US 20140308190A1
• Filed: 04/14/2014
• Published: 10/16/2014
• Est. Priority Date: 04/12/2013
• Status: Active Grant

• Current Assignee: Vitesco Technologies GmbH (Continental AG)
• Original Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Inventors: MAERTENS, Steven
• Granted Patent: US 10,449,494 B2
• Time in Patent Office: Days
• US Class Current: 423/212
• CPC Class Codes: B01D 53/9495 Controlling the catalytic process
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 2550/05 Systems for adding substances into exhaust
• CPC Class Codes: F01N 2560/026 for measuring or detecting NOx
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2900/1402 Exhaust gas composition
• CPC Class Codes: F01N 2900/1616 NH3-slip from catalyst
• CPC Class Codes: F01N 2900/1622 Catalyst reducing agent absorption capacity or consumption amount
• CPC Class Codes: F01N 3/208 Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• CPC Class Codes: F01N 9/005 using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Method for determining a true amount of active product entering a catalytic device of a vehicle exhaust line includes:

• • introducing, into the exhaust gas stream upstream of the device, an active flow rate of active product so that the contaminant and active product are absent at the measurement probe at the outlet of the device,
  • increasing the active flow rate until the second probe measures a given escape content of the product,
  • stabilizing the escape of product, via the measurement provided by the probe, at the given escape content,
  • introducing a theoretical additional test flow rate of product into the exhaust gas stream upstream of the device,
  • waiting until the total content of product measured in response at the second probe has stabilized, and measuring this stabilized total content, and
  • determining the stabilized true additional test flow rate of active product entering the device.

Claims

1. A method for determining a true amount of an active product (6) entering a catalytic device (1) of an exhaust line (2) of a vehicle, in response to the introduction into the exhaust line of a theoretical amount of said active product (6) under the orders of a unit (3) for controlling the catalytic device (1), the latter comprising:

at least one inlet (4) for a mixture comprising the exhaust gases and said active product (6), and

at least one outlet (5) for the exhaust gases,

said active product (6) acting inside the catalytic device (1) on the exhaust gases for the purpose of reducing or eliminating the content of at least one predetermined contaminant, at the outlet (5) of the catalytic device (1), the content of said at least one predetermined contaminant being measured in the exhaust gases by means of a measurement probe (8) sensitive to said at least one predetermined contaminant and to said active product and positioned at the outlet of the catalytic device (1), said method being characterized in that it comprises at least the following stages;

(100) introducing, into the exhaust gas stream upstream of the catalytic device (1), an active flow rate (fNH₃base) of said active product (6) so that said at least one predetermined contaminant and said active product (6) are absent at said measurement probe (8) at the outlet of the catalytic device (1),

(200) increasing said active flow rate (fNH₃base) of the active product until said probe (8) measures a given escape content (CNH₃escape) of said active product (6) at the outlet of the catalytic device (1), corresponding to an escape flow rate (fNH₃escape) of the active product,

(300) stabilizing said escape of the active product (6), via the measurement provided by said probe (8), at said given escape content (CNH₃escape),

(400a) subsequently ordering the introduction of a theoretical additional test flow rate (fNH₃theotest) of said active product (6) into the exhaust gas stream upstream of the catalytic device (1), by means of the unit (3) for controlling the catalytic device,

(400b) waiting until the total content of the active product (6) measured in response at said probe (8) has stabilized,

(500) measuring said stabilized total content (CNH₃tot) of said active product (6) at the outlet of the catalytic device (1) by means of said measurement probe (8),

(600) determining the stabilized true additional test flow rate (fNH₃truetest) of said active product (6) entering the catalytic device (1) by subtracting said given stabilized escape content (CNH₃escape) of active product from said stabilized total content (CNH₃tot) of the active product and by applying a model for conversion of the content obtained into a flow rate of active product.

2. The method as claimed in claim 1, in which said active product (6) is introduced indirectly via a product (7) which is a source of the active product (6).

3. The method as claimed in claim 2, additionally comprising a stage which consists in determining said theoretical additional test flow rate (fNH₃theotest) of said active product (6) entering said catalytic device (1) starting from an order to introduce a theoretical additional test flow rate of the product (7) which is a source of the active product into the exhaust gas stream upstream of the catalytic device and from a calculation model which converts said theoretical additional test flow rate of the source product (7) into said theoretical additional test flow rate (fNH₃theotest) of the active product at the inlet of the catalytic device.

4. The method as claimed in claim 1, in which said product (7) which is a source of said active product (6) is a mixture of urea and water.

5. The method as claimed in claim 1, additionally comprising a stage which consists in comparing said stabilized true additional test flow rate (fNH₃truetest) of said active product (6) with said theoretical additional test flow rate (fNH₃theotest) of said active product (6).

6. The method as claimed in claim 1, in which said active product (6) is ammonia and said at least one predetermined contaminant is a nitrogen oxide (NO_x), the catalytic device (1) being a “

selective catalytic reduction”

device.

7. The method as claimed in claim 1, in which said active product is a gaseous substance obtained from a heated solid component.

8. A device for determining a true amount of an active product (6) entering a catalytic device (1) of an exhaust line (2) of a vehicle, in response to the introduction into the exhaust line of a theoretical amount of said active product (6), comprising:

a unit (3) for controlling the catalytic device (1) capable of ordering the introduction into the exhaust line of a theoretical amount of said active product (6),

a catalytic device (1) comprising;

at least one inlet (4) for a mixture comprising the exhaust gases and said active product (6), and

at least one outlet (5) for the exhaust gases,

a measurement probe (8) positioned at the outlet of the catalytic device (1) and sensitive to said at least one predetermined contaminant and to said active product,

characterized in that it comprises means for the implementation of each of the stages of a method as claimed in claim 1.

9. The method as claimed in claim 2 in which said product (7) which is a source of said active product (6) is a mixture of urea and water.

10. The method as claimed in claim 3 in which said product (7) which is a source of said active product (6) is a mixture of urea and water.

11. The method as claimed in claim 2 additionally comprising a stage which consists in comparing said stabilized true additional test flow rate (fNH₃truetest) of said active product (6) with said theoretical additional test flow rate (fNH₃theotest) of said active product (6).

12. The method as claimed in claim 3 additionally comprising a stage which consists in comparing said stabilized true additional test flow rate (fNH₃truetest) of said active product (6) with said theoretical additional test flow rate (fNH₃theotest) of said active product (6).

13. The method as claimed in claim 4 additionally comprising a stage which consists in comparing said stabilized true additional test flow rate (fNH₃truetest) of said active product (6) with said theoretical additional test flow rate (fNH₃theotest) of said active product (6).