WO2012101230A1 - Urea scr system - Google Patents
Urea scr system Download PDFInfo
- Publication number
- WO2012101230A1 WO2012101230A1 PCT/EP2012/051265 EP2012051265W WO2012101230A1 WO 2012101230 A1 WO2012101230 A1 WO 2012101230A1 EP 2012051265 W EP2012051265 W EP 2012051265W WO 2012101230 A1 WO2012101230 A1 WO 2012101230A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pump
- urea
- pressure regulator
- scr system
- injector
- 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.)
- Ceased
Links
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
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion
- F01N3/206—Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents
- F01N3/208—Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B13/00—Pumps specially modified to deliver fixed or variable measured quantities
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B15/00—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts
- F04B15/04—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts the fluids being hot or corrosive
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B17/00—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
- F04B17/03—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors
- F04B17/04—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors using solenoids
- F04B17/046—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors using solenoids the fluid flowing through the moving part of the motor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/08—Regulating by delivery pressure
-
- 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
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
- F01N2610/1433—Pumps
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Definitions
- the present invention relates to a urea SCR system comprising a metering pump (preferably of the piston type) and a pressure regulator.
- the system used by most heavy goods vehicle manufacturers for reducing ⁇ emissions to the required value consists in carrying out a selective catalytic reaction with reducing agents such as urea ("Urea SCR" or selective catalytic reduction using ammonia generated in situ in the exhaust gases by
- the supply device comprises a rotary pump driven by a motor and which is regulated to supply the injector with urea solution at a given pressure.
- Gear pumps give good results in practice and as to the driving motors, those with magnetic coupling give good results since they allow heating of the urea solution (see for instance WO 2009/147146 in the name of the Applicant).
- Such pumps have however several drawbacks: they are rather complicated, expensive and since the magnetic coils, the case being, are generally not surrounding the cavity through which the liquid flows, heating is not optimum.
- the present invention aims at solving that problem by providing a urea SCR system comprising a metering pump and a pressure regulator.
- metering pumps are regulated to deliver a given flow rate and not a given pressure, which makes them unsuitable as such for SCR systems with an injector that must be supplied at constant pressure.
- the present invention solves that problem by coupling a pressure regulator to the metering pump.
- this pump is a piston pump driven by a magnetic coil wherein the coils are surrounding the internal volume where the liquid flows so that it can easily be unfrozen.
- the present invention applies to an SCR system i.e. a system able to meter a reducing agent capable of reducing the NO x present in the exhaust gases of the engine of a vehicle engine by Selective Catalytic Reduction. This is
- ammonia precursor in aqueous solution advantageously an ammonia precursor in aqueous solution.
- the invention gives good results with aqueous solutions of urea and in particular, eutectic water/urea solutions such as solutions of AdBlue ® , the urea content of which is between 31.8 wt% and 33.2 wt% and which contain around 18% of ammonia.
- the invention may also be applied to urea/ammonium formate mixtures also in aqueous solution, sold under the trademark Denoxium ® and which contain around 13% of ammonia.
- the latter have the advantage, with respect to urea, of freezing only from -35°C onwards (as opposed to -11°C), but have the disadvantages of corrosion problems linked to the release of formic acid.
- the SCR system comprises a metering pump (of the piston type preferably), an injector and a pressure regulator which is either located downstream of the pump (first embodiment) or integrated to it (second embodiment).
- the second embodiment is preferred because it is simpler, implies less hydraulic connections and allows defrosting the regulator together with the pump (which is especially easy with magnetic driven pumps as explained above).
- the first embodiment allows having less pressure variations.
- the injector is a regulated injector.
- the dosing is done by the opening time of the injector supplied with urea at a defined pressure.
- the injector is a "passive" injector.
- the dosing is done by the metering pump itself.
- Figure 1 attached relates to the first option (pressure regulator downstream of the pump) and Figure 2, to a preferred embodiment of the second option (pressure regulator integrated to the pump).
- Figure 1 shows an SCR system 100 with a urea tank 11, an injector 12, a piston/metering pump 13 and a mechanical pressure regulator 14 (ball+spring or plate+spring, etc..) in order to supply urea to the injector 12.
- a mechanical pressure regulator 14 ball+spring or plate+spring, etc..
- This system allows regulating the pressure delivered to the injector thanks to the use of a pump combined with a pressure regulator.
- FIG. 1 shows an SCR piston pump 200 with an integrated pressure regulator 21, leading to:
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Combustion & Propulsion (AREA)
- Exhaust Gas After Treatment (AREA)
Abstract
SCR system comprising a metering pump and a pressure regulator.
Description
Urea SCR system
The present invention relates to a urea SCR system comprising a metering pump (preferably of the piston type) and a pressure regulator.
With the Euro IV standard on exhaust emissions from heavy goods vehicles coming into effect in 2005, devices for pollution control of NOx (or nitrogen oxides) have had to be put in place.
The system used by most heavy goods vehicle manufacturers for reducing ΝΟχ emissions to the required value consists in carrying out a selective catalytic reaction with reducing agents such as urea ("Urea SCR" or selective catalytic reduction using ammonia generated in situ in the exhaust gases by
decomposition of urea).
In order to do this, it is necessary to equip the vehicles with a tank containing a urea solution, a device for metering the amount of urea to be injected into the exhaust line (generally called an injector) and a device for supplying, with urea solution, the device for metering the amount of urea to be injected. Generally, the supply device comprises a rotary pump driven by a motor and which is regulated to supply the injector with urea solution at a given pressure. Gear pumps give good results in practice and as to the driving motors, those with magnetic coupling give good results since they allow heating of the urea solution (see for instance WO 2009/147146 in the name of the Applicant).
Such pumps have however several drawbacks: they are rather complicated, expensive and since the magnetic coils, the case being, are generally not surrounding the cavity through which the liquid flows, heating is not optimum.
The present invention aims at solving that problem by providing a urea SCR system comprising a metering pump and a pressure regulator.
Generally speaking, metering pumps are regulated to deliver a given flow rate and not a given pressure, which makes them unsuitable as such for SCR systems with an injector that must be supplied at constant pressure. The present invention solves that problem by coupling a pressure regulator to the metering pump. Preferably, this pump is a piston pump driven by a magnetic coil wherein the coils are surrounding the internal volume where the liquid flows so that it can easily be unfrozen.
The present invention applies to an SCR system i.e. a system able to meter a reducing agent capable of reducing the NOx present in the exhaust gases of the engine of a vehicle engine by Selective Catalytic Reduction. This is
advantageously an ammonia precursor in aqueous solution. The invention gives good results with aqueous solutions of urea and in particular, eutectic water/urea solutions such as solutions of AdBlue®, the urea content of which is between 31.8 wt% and 33.2 wt% and which contain around 18% of ammonia. The invention may also be applied to urea/ammonium formate mixtures also in aqueous solution, sold under the trademark Denoxium® and which contain around 13% of ammonia. The latter have the advantage, with respect to urea, of freezing only from -35°C onwards (as opposed to -11°C), but have the disadvantages of corrosion problems linked to the release of formic acid.
According to the invention, the SCR system comprises a metering pump (of the piston type preferably), an injector and a pressure regulator which is either located downstream of the pump (first embodiment) or integrated to it (second embodiment).
The second embodiment is preferred because it is simpler, implies less hydraulic connections and allows defrosting the regulator together with the pump (which is especially easy with magnetic driven pumps as explained above).
The first embodiment allows having less pressure variations.
In one particular embodiment, the injector is a regulated injector. In this embodiment, the dosing is done by the opening time of the injector supplied with urea at a defined pressure.
In another particular embodiment, the injector is a "passive" injector. In this embodiment, the dosing is done by the metering pump itself.
Figure 1 attached relates to the first option (pressure regulator downstream of the pump) and Figure 2, to a preferred embodiment of the second option (pressure regulator integrated to the pump).
Description of Fig. 1 :
Figure 1 shows an SCR system 100 with a urea tank 11, an injector 12, a piston/metering pump 13 and a mechanical pressure regulator 14 (ball+spring or plate+spring, etc..) in order to supply urea to the injector 12.
This system allows regulating the pressure delivered to the injector thanks to the use of a pump combined with a pressure regulator.
Compared to the prior art systems, the main benefits of the invention are:
SCR competitiveness;
Urea flow through the pressure regulator increases the pump cooling; and availability of a range of pressures that meets customer's specifications. Description of Fig. 2:
Figure 2 shows an SCR piston pump 200 with an integrated pressure regulator 21, leading to:
a simple architecture (no need for a return line (that must be heated) between the pump outlet and tank);
an improved system for STT (Start & Go) versions, where the pressure needs to be maintained in the feeding line in order to accelerate restarting of the system. In fact, the pressure drops quickly when the pressure regulator is located behind (downstream of) the outlet check valve 22 of the piston pump (due to pressure regulator leakage & closing speed), as in Fig. 1. The pressure regulator 21 of Fig. 2 is now located in front (upstream) of the outlet check valve 22 (pressure is maintained in the feeding line). Also, pressure fluctuation (pulsation) in the feeding line is reduced.
The following advantages are also observed:
transfer of pump heat by return flow 23 will avoid frozen urea in pressure regulator, filter and pump inlet (bellow-lit);
return flow allows pump cooling; and
price reduction.
Claims
1. SCR system comprising a metering pump and a pressure regulator.
2. SCR system according to claim 1, wherein the pressure regulator is a separate device mounted downstream of the pump.
3. SCR system according to claim 1, wherein the pressure regulator is integrated to the pump.
4. SCR system according to any of the preceding claims, wherein the pump is a piston pump driven by magnetic coil(s) surrounding its internal volume.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP11152347 | 2011-01-27 | ||
| EP11152347.8 | 2011-01-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2012101230A1 true WO2012101230A1 (en) | 2012-08-02 |
Family
ID=45540876
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2012/051265 Ceased WO2012101230A1 (en) | 2011-01-27 | 2012-01-26 | Urea scr system |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2012101230A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109012175A (en) * | 2013-03-22 | 2018-12-18 | 日本碍子株式会社 | Reducing agent injection apparatus, emission-control equipment and waste gas processing method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002025075A1 (en) * | 2000-09-22 | 2002-03-28 | Robert Bosch Gmbh | Device for the dosing of a reducing agent |
| WO2003027454A1 (en) * | 2001-09-25 | 2003-04-03 | Argillon Gmbh | Reducing agent pump for an exhaust gas post-treatment unit on an internal combustion engine |
| WO2009147146A1 (en) | 2008-06-03 | 2009-12-10 | Inergy Automotive Systems Research (Société Anonyme) | Process for starting an scr system |
| WO2010119116A2 (en) * | 2009-04-16 | 2010-10-21 | Inergy Automotive Systems Research (Société Anonyme) | System and process for storing an additive and injecting it into the exhaust gases of an engine |
-
2012
- 2012-01-26 WO PCT/EP2012/051265 patent/WO2012101230A1/en not_active Ceased
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002025075A1 (en) * | 2000-09-22 | 2002-03-28 | Robert Bosch Gmbh | Device for the dosing of a reducing agent |
| WO2003027454A1 (en) * | 2001-09-25 | 2003-04-03 | Argillon Gmbh | Reducing agent pump for an exhaust gas post-treatment unit on an internal combustion engine |
| WO2009147146A1 (en) | 2008-06-03 | 2009-12-10 | Inergy Automotive Systems Research (Société Anonyme) | Process for starting an scr system |
| WO2010119116A2 (en) * | 2009-04-16 | 2010-10-21 | Inergy Automotive Systems Research (Société Anonyme) | System and process for storing an additive and injecting it into the exhaust gases of an engine |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109012175A (en) * | 2013-03-22 | 2018-12-18 | 日本碍子株式会社 | Reducing agent injection apparatus, emission-control equipment and waste gas processing method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102388208B (en) | System and process for storing an additive and injecting it into the exhaust gases of an engine | |
| US8122710B2 (en) | Thermal management of urea dosing components in an engine exhaust after-treatment system | |
| JP4095553B2 (en) | Reductant pump for exhaust gas aftertreatment device of internal combustion engine | |
| US8888017B2 (en) | System, method, and apparatus for delivering highly atomized diesel exhaust fluid to an exhaust aftertreatment system | |
| US20090205316A1 (en) | System and processes for storing an additive and injecting it into the exhaust gases of an engine | |
| EP2201228B1 (en) | System for storing an additive solution and injecting it into the exhaust gases of an engine | |
| RU2653265C2 (en) | Reductant dosing control systems and methods | |
| US20110265459A1 (en) | Reductant dosing manifold | |
| US11215100B2 (en) | Reductant insertion assemblies including multiple metering assemblies and a single pump | |
| JP2013512376A (en) | Method of operating the reducing agent feeding device | |
| CN103850761A (en) | Selective catalytic reduction system and purging method thereof | |
| CN104053873A (en) | Dosing device and dosing method for liquid tail gas aftertreatment medium | |
| US10180096B2 (en) | Fluid delivery system with line pressure control valve | |
| US20170002710A1 (en) | Anti-clogging device for diesel exhaust fluid supply | |
| JP2014218973A (en) | Exhaust emission control device for internal combustion engine | |
| WO2012101230A1 (en) | Urea scr system | |
| CN103161549B (en) | For heating the method for conveyor module in SCR catalyst system | |
| CN102536397A (en) | Urea supply device for vehicular SCR (selective catalytic reduction) system | |
| CN105308281A (en) | Method for operating a device for the dosed supply of a liquid | |
| JP2013536912A (en) | Reducing agent dispensing system for injecting reducing agent into an exhaust gas stream of an internal combustion engine | |
| US20140338311A1 (en) | Method for operating a dosing apparatus and motor vehicle having a dosing apparatus | |
| CN107532495B (en) | Reductant dosing system with modular structure | |
| CN105339662A (en) | Pump for metering liquid additive for selective catalytic reduction device | |
| CN202544973U (en) | Urea supply device for vehicular SCR (Selective Catalytic Reduction) system | |
| CN207470267U (en) | Urea filtration system and after-treatment system component |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12701352 Country of ref document: EP Kind code of ref document: A1 |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 12701352 Country of ref document: EP Kind code of ref document: A1 |