• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to an internal combustion engine (1) having at least one exhaust gas line (2) in which at least one exhaust aftertreatment device (3), in particular at least one SCR catalytic converter (3a) is arranged, wherein upstream of the exhaust gas aftertreatment device (3) into the exhaust gas flow (S ) a metering device (4) for a particular ammonia-containing additive in the region of a mixing device (5) for introducing the additive into the exhaust stream (S) opens. In order to achieve an efficient treatment of the additive in the exhaust gas with the smallest possible space requirement, it is provided that the mixing device (5) has at least one heating device (7).
    公开号:AT512193A1
    申请号:T1736/2011
    申请日:2011-11-24
    公开日:2013-06-15
    发明作者:
    申请人:Avl List Gmbh；
    IPC主号:
    专利说明:

    1 56291
    The invention relates to an internal combustion engine with an exhaust system, in which at least one exhaust aftertreatment device, in particular at least one SCR catalyst is arranged, wherein upstream of the exhaust aftertreatment device in the exhaust stream a metering device for a particular ammonia-containing additive in the range of a mixing device for introducing the additive into the Exhaust gas flows.
    WO 2008/122 724 A1 discloses an internal combustion engine having an exhaust gas line, in which an SCR catalytic converter is arranged, an additive being injected into the exhaust gas line via a metering device and a mixing device upstream of the SCR catalytic converter.
    Due to the low injection pressures of the additive, relatively large drops are formed in the exhaust gas flow. This results in long evaporation times and long path lengths. The path lengths required for complete evaporation are usually unavailable in mobile applications.
    A uniform distribution of the additive across the cross-section of an exhaust system for all relevant operating points is hard to achieve.
    A large-scale mixing of non-uniform distributed gas components can be achieved with the usual pipe / mixing elements at the low available path lengths difficult or only with considerable pressure loss.
    In addition, it often comes to wall contact of the injected droplets with the cold walls of the exhaust line, which can form unwanted deposits.
    It is known to use mixers, which usually cause only a local mixing. On the other hand, vortex mixers (vortex mixers) are used, but they require a large pipe length.
    The object of the invention is to allow with the least possible structural and spatial complexity, a uniform distribution of the additive at the entrance to the aftertreatment device and thereby to avoid deposits. 2
    According to the invention, this is accomplished by having the fyL < < RTI ID = 0.0 > tfpclest < / RTI > a heater.
    Preferably, the heating device is formed by at least one flow guide for the exhaust gas stream before or in the mixing device. The flow guide can form at least one flow separation edge at its downstream end. The use of the release edge results in a resulting wall film being introduced into the flow. On the other hand, the introduction of the liquid phase or of the highly concentrated gaseous NH 3 in the main stream promotes thorough mixing, since propagation in all directions is made possible.
    In order to achieve a good atomization, it can be provided that the heating device forms a baffle plate for the introduced additive, wherein the metering device is directed to the baffle plate, wherein preferably the baffle plate is arranged in the region of entry of the exhaust gas stream into the mixing device. Heating ribs may be arranged on the side of the baffle plate facing away from the injected additive. The atomization can be further improved if the flow guide surface has guide ribs which are arranged essentially parallel to one another in the direction of the exhaust gas flow and are preferably heatable.
    In a preferred embodiment of the invention, the flow guide surface preferably forming the baffle plate is arranged parallel to the exhaust gas flow entering the mixing device.
    Alternatively, it can also be provided that the flow-guiding surface is arranged inclined at a preferably acute angle to the exhaust-gas flow entering the mixing device and forms a deflection surface for the exhaust-gas flow, which preferably forms the heating device. In particular, in the case of an arrangement with purely axial exhaust gas flow metering of the additive directly onto the impact surface or onto a heating surface is not possible, so that the spray is transported by the flow onto the deflection surfaces of the cyclone. These deflection surfaces thus have the same function as heating surfaces.
    It is particularly advantageous if the flow-guiding surface and / or the baffle plate are preferably tangential in a concavely curved first guide surface of the 3 • t · · · · · ··
    Blending device merges, preferably wherein the erä ^ iLqjifläfhean ibfe Q. · at the end of at least one first peel edge forms.
    The mixing device is preferably designed as a cyclone.
    The preparation of the additive jet is thus carried out by a combination of pre-evaporation and atomization and subsequent mixing in the cyclone. The introduction of the additive into the cyclone via at least one detachment edge, so that the liquid phase or the high-centered gaseous additive (for example, a NH 3 -water mixture) is introduced in the main stream in the cyclone and on all sides and not from a wall can interfere with disabled.
    To avoid deposits in the pre-evaporation on the baffle plate cooling of the baffle plate is avoided below the critical temperature by means of the heater.
    In a particularly advantageous embodiment of the invention, at least two, preferably helical or cylindrical, concavely curved guide surfaces are arranged in the flow direction, wherein preferably mutually facing ends of the guide surfaces are arranged in a radial direction offset from one another such that the end of an upstream guide surface is arranged in the region of the concave side of the downstream guide surface.
    The mixing device has a central tube, wherein the at least one guide surface are arranged around the central tube at a distance, so that between the central tube and the guide surface is formed by an exhaust gas flowed annular space, wherein preferably at least one end face of the annular space is closed.
    With the central tube inside the cyclone, the channel cross-section is reduced. This avoids poor mixing in the center of the cyclone. The central tube can be flowed through slightly to equalize the wall temperature to the gas temperature and thus to prevent wall film formation.
    In a particularly preferred embodiment of the invention, it is provided that the central tube has an upstream first end and a downstream second end, wherein the central tube in the region of the first end is flow-connected to the annular space and wherein the annular space in the region of the second 4 4 «· ♦
    End is closed. Thus an additional branch of the central tube arises by diverting the flow from the annulus into the interior of the central tube. By this additional flow deflection mixing can be further enhanced. This is particularly advantageous if compromises have to be made in the positioning of the injector.
    The preparation of the introduced additive can be done in this way with extremely low pressure losses. The evaporation and thermolysis of the additive is completed until it leaves the cyclone. Through the cyclone there is a global mixing, so that high uniformity of the gas components can be achieved.
    The invention will be explained in more detail below with reference to FIG.
    1 shows an internal combustion engine according to the invention, FIG. 2 shows a mixing device of this internal combustion engine in a first embodiment in an oblique view, FIG. 3 shows this mixing device in a view in the direction of the cyclone axis, FIG. 4 shows a mixing device in a second embodiment in an oblique view 5 shows a mixing device in a third embodiment in an oblique view, FIG. 6 shows a mixing device in a fourth embodiment in a side view, and FIG. 7 shows this mixing device in a section according to the line VII-VII in FIG. 6.
    1 shows an internal combustion engine 1 with a plurality of cylinders 1a with an exhaust gas line 2, in which an exhaust gas aftertreatment device 3 formed by an SCR catalytic converter 3a is arranged. Upstream of the exhaust gas aftertreatment device 3, a metering device 4 for an additive, for example a urea-water mixture, is arranged. The injection nozzle 4 'of the metering device 4 is arranged in the region of the inlet 5a of the exhaust gas stream S in a mixing device 5, which is formed by a cyclone 6.
    The mixing device 5 has at least one heating device 7, which prevents a deposition of additive drops on the wall of the mixing device 5.
    In the embodiment variants shown in FIGS. 2 to 5, the mixing device 5 is separated by a cyclone 6 with tangentially or radially inflowing 5 •
    Exhaust gas flow S formed. The cyclone 6 has a flow control surface 8 for the exhaust gas flow S forming a baffle 8a for the introduced additive, the nozzle 4 'of the metering device 4 being directed towards the baffle plate 8a. The baffle plate 8a at the same time forms the heating device 7, which may be formed for example by heating ribs 7a on the back of the baffle plate 8a. The baffle plate 8a may also be ribbed in the impact area and / or form a number of heatable baffles directed parallel to the incoming exhaust gas flow S. The flow guide surface 8 is arranged tangentially to a concavely curved first guide surface 9 in the embodiments shown in FIGS. 2 to 4, which is partially guided around a central tube 10 by an angle α of, for example, at least about 90 °, for example 120 ° at a distance. The first guide surface 9 terminates in a first separation edge 11 for the exhaust gas flow S. The cyclone 6 has in the embodiments shown in FIGS. 2 to 4 a concave, preferably cylindrically curved second guide surface 12, which begins approximately in the region of the first detachment edge 11 and extends around the central tube 10 by an angle β of, for example, about 240 degrees. The second guide surface 12 terminates in a second detachment edge 13. Both the first guide surface 9 and the second guide surface 12 are radially spaced from the central tube 10, so that an annular space 14 is spanned between the central tube 10 and the first and second guide surfaces 9, 12 is, wherein at least one end face 14a, 14b of the annular space 14 may be substantially closed. The beginning 12a of the second guide surface 12 is further spaced from the central tube 10 than the first detachment edge 11. The cyclone 6 has a closed first end face 6a located in FIGS. 2, 4 and 5 on the underside and one in FIGS , 4 and 5 shown at the top open second end face 6b. The laterally - in Figs. 2 to 4 tangentially - entering the cyclone 6 exhaust gas flows according to the arrows S along the baffle plate 8 and is passed through the baffle plate 6 and the first and second guide surface 11, 12 in the annular space 14 where a Ring flow is formed at high speed. Due to the geometric conditions in the cyclone 6, the annular flow 6 is deflected axially, whereby the exhaust gas flow S leaves the cyclone 6 at the second end face 6b. About the metering device 4, the additive - for example, a NH3-water mixture - introduced on the baffle plate 8a. In this case, an atomization occurs by impact on the baffle plate 8a, whereby it comes - with appropriate kinetic and / or thermal energy - drop breakage. In order to prevent the spraying process from causing the 6 • «·· ·« · · · · · ·
    Baffle plate 8 is cooled too much and for the Geftlji vA Vlfon <3fl4rflJj'ydurfc and deposits, the baffle plate 8 is heated by the heater 7.
    The Zyklon 6 allows large-scale efficient gas mixing with low pressure drop. The mixture of exhaust gas and additive is passed via the guide surfaces 11 and 12 in the annular space 14, where an intense mixing takes place. The effect of the first and the second detachment edges 11, 13 is that a wall film possibly forming on the guide surfaces 9, 12 is introduced into the exhaust gas flow S. On the other hand, the introduction of the liquid phase or of the highly concentrated gaseous NH 3 in the main stream promotes thorough mixing, since propagation in all directions is made possible.
    Through the central tube 10 in the interior of the cyclone 6, the channel cross-section of the annular space 14 is reduced. This avoids poor mixing in the center of the cyclone 6. The central tube 10 may optionally be slightly flowed through in order to equalize the wall temperature of the central tube 10 to the exhaust gas temperature and thus to prevent wall film formation on the outside of the central tube 10.
    The preparation of the additive spray is thus carried out by a combination of Vorverdampfung / atomization and subsequent mixing in the cyclone 6. The introduction of the additive into the cyclone 6 via the separation edges 11, 13, so that the liquid phase or the highly concentrated gaseous NH3 im Mainstream is introduced into the cyclone 6 and on all sides - and not obstructed by a wall - can mix.
    In this way it is achieved that the evaporation and the thermolysis of the additive is completed until it leaves the mixing device 5. Through the cyclone 6 there is a global mixing, so that a high uniformity of the gas species can be achieved.
    4 shows a variant in which the entire exhaust gas flow S is guided through the central tube 10, wherein the mixing upon entry into the central tube 10 can be further enhanced by an additional flow deflection, which is represented by the arrows Si. The axial extent b of the central tube 10 is smaller than the axial extent a of the first and second guide surfaces 9, 12. An upstream first end of the central tube 10 is connected to 10a, a downstream second end of the central axis , A second end face 14b of the annular space 14 is substantially closed in the region of the second end 10b of the central tube 10. In the region of the first end 10a and the first end face 14a of the annular space 14, the central tube 10 is made shorter than the guide surfaces 9, 12, whereby an annular flow passage between the annular space 14 and the central tube 10 is formed. The exhaust gas flows according to the arrows S along the baffle plate 8 in the cyclone 6 and is guided along the first and second guide surfaces 9, 12 annularly around the central tube 10 in the annular space 14. Since the annular space 14 is closed in the region of the second end face 14b, the exhaust flows according to the arrows Si in the region of the first end 10a of the central tube 10 in the central tube 10 and further in the axial direction within the central tube 10 to the second end 10b, where it Cyclone 6 leaves. This embodiment variant is particularly advantageous if the metering device 4 for the additive can not be optimally positioned. In this case, the additional deflection nevertheless achieves excellent mixing of the additive with the exhaust gas.
    In Fig. 5, an embodiment is shown, in which the baffle plate 8 is not tangential, but radially with respect to the cyclone 6 is arranged. In this way, an additional separation edge 15 is formed by a step in the transition region between the baffle plate 8 and the first guide surface 9, which allows an early detachment of a wall film.
    6 and 7 show a further embodiment in which a purely axial flow of the mixing device 5 takes place. The heating device 7 is formed by deflecting surfaces 16a, 16b forming flow guide 8 of the cyclone 6, which are arranged tangentially to substantially cylindrical first and second guide surfaces 17, 18 and pass into this. The first and second guide surfaces 17, 18 are formed substantially cylinder-segment-like and extend over an angular range γ between about 120 ° - 170 °, wherein between the first deflection surface 16a and the second guide surface 18, a first gap 19, and between the second deflection surface 16b and the first guide surface 17, a second gap 20 is formed, which forms a flow passage to a central space 21 for the exhaust gas flow S. The metering of the additives takes place via the metering device 4 arranged upstream of the mixing device 5. The exhaust gas flows in a space between the exhaust pipe 22 and the guide surfaces 17, 18 * ff * V *. formed substantially cylindrical annular space 23j vyfelqljgrjfo £ ςίπβς. * .. · downstream end face 24 is closed. About the deflection surfaces 16a, 16b, the exhaust gas is passed through the first and the second gap 19, 20 in the central space 21, wherein the exhaust gas flow S is imparted a twist. A liquid film possibly adhering to the first and second guide surfaces 17, 18 is released at the detachment edges 17a, 18a of the guide surfaces 17, 18, whereby liquid particles are entrained by the exhaust gas flow S. The fact that the deflection surfaces 16a, 16b also fulfill the function of heaters 7, the evaporation and thermolysis of the additive can be significantly accelerated.
    The exhaust gas flow leaves the central space 21 in the axial direction and exits axially from the cyclone 6 according to the arrow S to - mixed with additive - to enter the subsequent SCR catalyst 3. Again, evaporation and thermolysis of the additive at the outlet of the cyclone 6 are largely completed.
    权利要求:
    Claims (12)
    [1]
    1. Internal combustion engine (1) with at least one exhaust gas line (2), in which at least one exhaust aftertreatment device (3), in particular at least one SCR catalytic converter (3a) is arranged, wherein upstream of the exhaust gas aftertreatment device (3) in the exhaust stream (S) a metering device (4) for an additive containing in particular ammonia in the region of a mixing device (5) for introduction of the additive into the exhaust gas stream (S), characterized in that the mixing device (5) has at least one heating device (7).
    [2]
    2. Internal combustion engine (1) according to claim 1, characterized in that the heating device (7) is formed by at least one flow guide surface (8) for the exhaust gas flow (S) in front of or in the mixing device (5), wherein preferably the flow guide surface (8). at least one flow separation edge (15) is formed at its downstream end.
    [3]
    3. Internal combustion engine (1) according to claim 1 or 2, characterized in that the heating device (7) forms a baffle plate (8 a) for the introduced additive, wherein the metering device (4) is directed to the baffle plate (8 a), preferably on the downstream side of the baffle plate (8a) heating ribs (7a) are arranged.
    [4]
    4. Internal combustion engine (1) according to claim 3, characterized in that the baffle plate (8 a) in the region of the inlet (5 a) of the exhaust gas stream (S) in the mixing device (5) is arranged.
    [5]
    5. internal combustion engine (1) according to one of claims 2 to 4, characterized in that the flow guide (8) arranged substantially parallel to each other in the direction of the exhaust gas stream (S), preferably heatable, guide ribs.
    [6]
    6. Internal combustion engine (1) according to any one of claims 2 to 5, characterized in that the preferably the baffle plate (8a) forming the flow guide surface (8) is arranged substantially parallel to the mixing device (5) entering the exhaust stream (S). • ·· «·» · · · · · »
    [7]
    7. internal combustion engine (1) according to one of Ansprüc ^ .A 1¾¾ 5, tt | a4M £ f) i · .. · characterized in that the flow guide surface (8) at a preferably acute angle (a) for in the mixing device (5) entering exhaust gas stream (S) is arranged inclined.
    [8]
    8. Internal combustion engine (1) according to one of claims 2 to 7, characterized in that the Strömungsleitfläche (8) and / or the baffle plate (8a) preferably tangentially into a concavely curved first guide surface (9) of the mixing device (5), wherein Preferably, the first guide surface (9) at its downstream end at least a first separation edge (11) is formed.
    [9]
    9. Internal combustion engine (1) according to one of claims 1 to 8, characterized in that in the flow direction successively at least two, preferably helical or cylindrical, concave guide surfaces (9, 12) are arranged, preferably facing each other ends of the guide surfaces (9, 12) are offset from one another in a radial direction such that the end of the upstream first guide surface (9) is disposed in the region of the concave side of the downstream second guide surface (12).
    [10]
    10. Internal combustion engine (1) according to one of claims 1 to 9, characterized in that the mixing device (5) is designed as a cyclone (6).
    [11]
    11. Internal combustion engine (1) according to any one of claims 8 to 10, characterized in that the mixing device (5) has a central tube (10), wherein the at least one guide surface (9, 12) around the central tube (10) are arranged at a distance in that an annular space (14) through which the exhaust gas flows is formed between the central tube (10) and the guide surface (9, 12), preferably at least one end face (14a, 14b) of the annular space (14) being closed.
    [12]
    12. internal combustion engine (1) according to claim 11, characterized in that the central tube (10) has an upstream first end (10 a) and a downstream second end (10 b), wherein the central tube (10) in the region of the first end (10 a) is fluidly connected to the annulus (14) 11 • Φ * * · · · * ·, and preferably wherein an end face (14b) ^^ @ | Q9lwn £ U &nbsp; * region of the second end (10b) is closed. 2011 11 24 Fu / St Patent Attorney

    Dipl.-Ing. Michael babciuk Λ-ltSO Vienna, Murlahll + tr Günei jWjj Til .; (+43 i; 83 * «ti 33 * fi *. (+42 1} W2J» 'Π · ιΙ (| * «» fwp (pih »bi *
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    同族专利:
    公开号 | 公开日
    DE102012111335A1|2013-05-29|
    AT512193B1|2013-10-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    WO2006014129A1|2004-08-06|2006-02-09|Scania Cv Ab |Arrangement for supplying a medium into an exhaust gas conduit in an internal combustion engine|
    EP1748162A1|2005-07-28|2007-01-31|Hitachi, Ltd.|Exhaust aftertreatment system using urea water|
    WO2008024535A2|2006-08-23|2008-02-28|Universal Silencer, Llc.|Exhaust aftertreatment system with spiral mixer|
    EP1936137A1|2006-12-12|2008-06-25|Bayerische Motoren Werke Aktiengesellschaft|Device for adding a reducing agent to a flue gas stream of a combustion engine|
    FR2914353A1|2007-03-26|2008-10-03|Renault Sas|INTERNAL COMBUSTION ENGINE EXHAUST LINE WITH MEANS FOR REDUCING NITROGEN OXIDES|DE102013211662A1|2013-06-20|2014-12-24|Friedrich Boysen Gmbh & Co. Kg|Mixer means|
    DE102014009015A1|2014-06-17|2015-12-17|Daimler Ag|Mixing device of an exhaust gas purification system of a motor vehicle internal combustion engine|
    DE102016101055A1|2016-01-21|2017-07-27|Benteler Automobiltechnik Gmbh|SCR exhaust aftertreatment arrangement|
    WO2017151972A1|2016-03-02|2017-09-08|Watlow Electric Manufacturing Company|Thermal storage device for use in a fluid flow system|
    DE102018204703A1|2018-03-28|2019-10-02|Robert Bosch Gmbh|Apparatus for providing an ammonia-containing exhaust aftertreatment agent, exhaust aftertreatment device, exhaust aftertreatment system and method|
    DE102019126578A1|2019-10-02|2021-04-08|Denso Corporation|Technology for the homogenization of exhaust gas mixtures|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    ATA1736/2011A|AT512193B1|2011-11-24|2011-11-24|INTERNAL COMBUSTION ENGINE WITH AN EXHAUST SYSTEM|ATA1736/2011A| AT512193B1|2011-11-24|2011-11-24|INTERNAL COMBUSTION ENGINE WITH AN EXHAUST SYSTEM|
    DE102012111335A| DE102012111335A1|2011-11-24|2012-11-23|Internal combustion engine, has mixing device comprising heating device formed by flow conducting surface that projects into concavely curved surface of mixing device, where concave surface forms separating edge at downstream end|
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