Method for determining the quality of reducing agent

Patent metadata

Field	Value
Publication number	US-2016195487-A1
Application number	US-201414910571-A
Country	US
Kind code	A1
Filing date	Jul 31, 2014
Priority date	Aug 7, 2013
Publication date	Jul 7, 2016
Grant date	—

Abstract

In a method for determining a quality of reducing agent, a pretreatment of the reducing agent is firstly performed. The temperature of the pretreated reducing agent is subsequently determined. The electrical conductivity of the pretreated reducing agent is then determined, and subsequently, the quality of the reducing agent is calculated with the aid of the electrical conductivity and the temperature.

First claim

1 - 14 . (canceled)

15 . A method for determining a quality of reducing agent, comprising at least the following steps:
i) performing a pretreatment of the reducing agent; ii) determining a temperature of the pretreated reducing agent; iii) determining an electrical conductivity of the pretreated reducing agent; and iv) calculating a quality of the reducing agent based on the determined electrical conductivity and the determined temperature.

16 . The method according to claim 15 , wherein the determination of the electrical conductivity of the reducing agent in step iii) is performed by means of a sensor ( 5 ) with a first electrical contact ( 6 ) and a second electrical contact ( 7 ) which are electrically connected to the reducing agent.

17 . The method according to claim 16 , wherein, in step iii), a voltage is applied in each case between at least the first electrical contact ( 6 ) and the second electrical contact ( 7 ) and between the first electrical contact ( 6 ) and a third electrical contact ( 25 ), wherein electrical resistances between the first electrical contact ( 6 ) and the second electrical contact ( 7 ) and between the first electrical contact ( 6 ) and the third electrical contact ( 25 ) are determined and, in step c), a conductance is determined from the two determined electrical resistances.

18 . The method according to claim 16 , wherein, in step iii), an alternating voltage is applied.

19 . The method according to claim 15 , wherein, in step i), at least one selected from the group consisting of the following measures is implemented for the pretreatment of the reducing agent:
filtration of the reducing agent; electrochemical treatment of the reducing agent; thermal treatment of the reducing agent; and at least partial separation of at least one component out from the reducing agent.

20 . A dosing device ( 1 ) for a reducing agent, comprising:
a tank ( 2 ) having a tank wall ( 3 ) and an interior ( 4 ) at least partially delimited by the tank wall ( 3 ); a sensor ( 5 ) configured to determine electrical conductivity of the reducing agent; an exhaust line ( 10 ); a pretreatment unit ( 29 ) configured to pretreat the reducing agent; and at least one line ( 9 ) via which the reducing agent is extracted from the interior ( 4 ), the at least one line ( 9 ) being connected in terms of flow to the interior ( 4 ) such that the reducing agent can be conducted from the interior ( 4 ) through the line ( 9 ) into the exhaust line ( 10 ), wherein both the sensor ( 5 ) and the pretreatment unit ( 29 ) are arranged on the line ( 9 ).

21 . The dosing device ( 1 ) according to claim 20 , wherein the sensor ( 5 ) has a first electrical contact ( 6 ) and a second electrical contact ( 7 ) each of which are electrically connected to the reducing agent.

22 . The dosing device ( 1 ) according to claim 21 , further comprising a capillary barrier ( 26 ) formed by a cohesive connection between firstly at least the first electrical contact ( 6 ) or the second electrical contact ( 7 ) and secondly at least one fastening section ( 27 ) of the line ( 9 ),
wherein at least one selected from the group consisting of the first electrical contact ( 6 ) and the second electrical contact ( 7 ) is sealed off in liquid-tight fashion on the line ( 9 ) by the capillary barrier ( 26 ).

23 . The dosing device ( 1 ) according to claim 21 , further comprising a capillary barrier ( 26 ) realized by a form fit between firstly at least the first electrical contact ( 6 ) or the second electrical contact ( 7 ) and secondly at least one fastening section ( 27 ) of the line ( 9 ),
wherein at least one selected from the group consisting of the first electrical contact ( 6 ) and the second electrical contact ( 7 ) is sealed off in liquid-tight fashion on the line ( 9 ) by the capillary barrier ( 26 ).

24 . The dosing device ( 1 ) according to claim 20 , wherein the sensor ( 5 ) has a third electrical contact ( 25 ).

25 . The dosing device ( 1 ) according to claim 20 , further comprising a temperature sensor ( 15 ).

26 . The dosing device according to claim 21 , wherein the first and second electrical contacts ( 6 , 7 ) are formed from at least one selected from the group consisting of the following materials:
graphite, high-grade steel, and platinum.

27 . The dosing device ( 1 ) according to claim 20 , wherein the pretreatment unit ( 29 ) comprises at least one selected from the group consisting of the following components:
at least one filter ( 14 ) configured to purify the reducing agent flowing through the line ( 9 ); at least one electrical contact ( 6 , 7 , 25 ), wherein the at least one electrical contact ( 6 , 7 , 25 ) is configured to perform an electrochemical treatment of the reducing agent; at least one heater ( 31 ) configured to thermally treat the reducing agent; and at least one separator ( 30 ) by which at least one component can be at least partially separated out from the reducing agent.

28 . A motor vehicle ( 16 ), comprising:
an internal combustion engine ( 17 ); an exhaust-gas treatment device ( 18 ); an exhaust line ( 10 ); and a dosing device ( 1 ) according to claim 20 .

Assignees

• Emitec Emissionstechnologie

Inventors

• Hodgson Jan
• Schepers Stevn
• Bergmann Andree
• Moeller Morten-Peter

Classifications

• G01N27/06 Primary

  of a liquid (involving electrolysis G01N27/26) · CPC title

• G01N25/00

  Investigating or analyzing materials by the use of thermal means (G01N3/00 - G01N23/00 take precedence) · CPC title

• F01N2550/05

  Systems for adding substances into exhaust · CPC title

• F01N3/206

  Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents · CPC title

• F01N11/00

  Monitoring or diagnostic devices for exhaust-gas treatment apparatus · CPC title