CN112302767B - Urea mixer - Google Patents

Urea mixer Download PDF

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Publication number
CN112302767B
CN112302767B CN202011341291.2A CN202011341291A CN112302767B CN 112302767 B CN112302767 B CN 112302767B CN 202011341291 A CN202011341291 A CN 202011341291A CN 112302767 B CN112302767 B CN 112302767B
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Prior art keywords
blade
working position
rotating
piece
flow area
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CN112302767A (en
Inventor
王意宝
张素英
柴洋
薛裕丹
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Weichai Power Co Ltd
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Weichai Power Co Ltd
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    • 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
    • F01N3/24—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 constructional aspects of converting apparatus
    • F01N3/28—Construction of catalytic reactors
    • F01N3/2892—Exhaust flow directors or the like, e.g. upstream of catalytic device
    • 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
    • F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
    • F01N2570/14—Nitrogen oxides
    • 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
    • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
    • 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
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

The invention discloses a urea mixer. This urea blender includes hybrid tube, first blade, second blade, control system, wherein: the first blade and the second blade are both arranged in the mixing pipe; the control system is used for driving the second blade to rotate from the first working position to the second working position and is used for driving the second blade to rotate from the second working position to the first working position; when the second blade is positioned at the first working position, the second blade is axially overlapped with the first blade so as to enable the flow area in the mixing pipe to be a first flow area; when the second blade is located at the second working position, the second blade and the first blade are circumferentially staggered, so that the flow area in the mixing pipe is the second flow area, and the second flow area is smaller than the first flow area. The invention can solve the problem of urea crystallization of the SCR system of the vehicle under low load and low exhaust temperature.

Description

Urea mixer
Technical Field
The invention relates to the technical field of vehicle manufacturing, in particular to a urea mixer.
Background
SCR: selective Catalytic Reduction, specifically NH, under the action of a catalyst3And NOxThe reduction denitrification reaction is carried out to generate nitrogen and water.
And (3) urea crystallization: heating and decomposing urea to generate ammonia gas and simultaneously turn the ammonia gas into cyanic acid, and further condensing the cyanic acid under certain conditions to generate substances such as biuret, triurea, cyanuric acid, melamine and the like, namely urea crystals.
The basic principle of SCR technology is to inject fuel or add other reducing agents into the exhaust, select appropriate catalysts, and promote the reducing agents and NOxThe reaction is suppressed while the reducing agent is inhibited from being oxidized by oxygen in the exhaust gas. The existing SCR technology can be classified into NH generated by decomposition of urea according to the kind of the reducing agent3Urea SCR technology as a reducing agent and hydrocarbon SCR technology with hydrocarbon as a reducing agent. At present, the hydrocarbon SCR technology is still under further research and is not applied in a large number of fields; and the urea SCR technology is mature, and the practical application is more.
The problem that deposits such as urea crystal stones are easily generated when a diesel vehicle of the SCR system runs under low-load conditions is always a main factor influencing the stable running of the vehicle. Vehicle runningIn the process, the injected urea droplets cannot be converted into NH in real time due to poor atomization, uneven mixing or insufficient decomposition of urea3But by-products are formed, resulting in unstable reduction reaction and thus affecting NOxConsistency of emissions and conversion efficiency. The urea sediment can be divided into urea crystal and urea calculus according to the forming process, the urea crystal is generated by the precipitation of supersaturated urea in the urea solution due to the loss of water in the urea solution, is a product in the physical reaction process, and can be continuously decomposed along with the rise of the temperature; the urea calculus is caused by a by-product generated by a side reaction in the urea decomposition process, belongs to a chemical reaction product, and can be decomposed only by high temperature. Because the mass of urea liquid drops is much larger than that of gas, crystals formed in a gas flow stagnation area are reserved, if the urea liquid drops cannot be completely decomposed in time, the urea liquid drops can grow continuously by taking the crystals as pronuclei, urea crystal stones are finally formed due to incomplete decomposition, and the urea crystal stones are accumulated to a certain extent and possibly block a urea flow channel, so that the analysis on the generation of sediments needs to be carefully researched.
Referring to fig. 1, a static mixer in the prior art adopts a swirl plate structure, specifically, a swirl plate 02 and a urea nozzle 03 are disposed on a urea mixing pipe 01. The structure of the spinning disk can not be adjusted along with the change of flow and temperature, and urea is thrown on the wall surface of the mixing pipe at low temperature to form crystals which can not be removed.
Disclosure of Invention
In view of the above, the present invention provides a urea mixer, which can solve the problem of urea crystallization of an SCR system under low load and low exhaust temperature of a vehicle.
In order to achieve the purpose, the invention provides the following technical scheme:
a urea mixer comprising a mixing tube, a first vane, a second vane, a control system, wherein:
the first blade and the second blade are both disposed within the mixing tube;
the control system is used for driving the second blade to rotate from a first working position to a second working position and driving the second blade to rotate from the second working position to the first working position;
when the second blade is located at the first working position, the second blade is axially overlapped with the first blade so that the flow area in the mixing pipe is a first flow area;
when the second blade is located at the second working position, the second blade and the first blade are circumferentially staggered, so that the flow area in the mixing pipe is a second flow area, and the second flow area is smaller than the first flow area.
Optionally, in the urea mixer, a plurality of first blades are arranged in sequence along the circumferential direction, one end of each first blade is fixedly connected with the fixed supporting piece, and the other end of each first blade is fixedly connected with the inner wall of the mixing pipe;
the second blades are arranged in a plurality of groups and are sequentially distributed along the circumferential direction, the connecting end of each second blade is fixedly connected to a rotating piece, and the rotating piece is coaxially sleeved on the fixed supporting piece or coaxially sleeved in the fixed supporting piece;
the control system is connected with the rotating piece and used for driving the rotating piece to rotate around a central axis to the first working position or the second working position.
Optionally, in the urea mixer, the rotating part is provided with a rotating part connecting part, and the control system includes a pull rod and a driver, wherein:
two ends of the pull rod are respectively connected with the driver and the rotating part connecting part;
the driver is arranged on the outer side of the mixing pipe and used for driving the rotating piece to rotate through the pull rod.
Alternatively, in the above urea mixer, the driver is a solenoid valve.
Alternatively, in the urea mixer described above, the rotating member connecting portion is a connecting rod provided at a side end of the rotating member;
the end part of the pull rod is provided with a pull ring structure in clearance fit with the connecting rod, and the pull ring structure is an annular ring or a bent sleeve hook.
Optionally, in the urea mixer, the fixed supporting element is a central shaft, and the rotating element is a sleeve fitted to the central shaft, wherein:
a guide groove is formed in the side wall of the fixed supporting part, a sliding protrusion matched with the guide groove is arranged on the inner wall of the rotating part, and the rotating part rotates around the fixed supporting part from the first working position to the second working position when the sliding protrusion slides from the first position to the second position in the guide groove;
or, a sliding protrusion is arranged on the side wall of the fixed supporting part, a guide groove matched with the sliding protrusion is arranged on the inner wall of the rotating part, and the sliding protrusion slides from a first position to a second position in the guide groove, so that the rotating part rotates around the fixed supporting part from the first working position to the second working position;
or, a guide groove is formed in the side wall of the fixed supporting part, a ball is nested on the inner wall of the rotating part, and the ball slides from a first position to a second position in the guide groove, so that the rotating part rotates around the fixed supporting part from the first working position to the second working position;
or, be provided with the guide way on the inner wall of rotation piece, the nestification is provided with the ball on fixed support piece's the lateral wall, the ball is in slide to the second position by the primary importance in the guide way, then the rotation piece winds fixed support piece is by the primary importance rotates to the second operating location.
Optionally, in the urea mixer, a spring and a limit end are further included;
the limiting end is fixedly connected with the fixed supporting piece, and the limiting end and the first blade are respectively positioned on two sides of the rotating piece;
the spring is sleeved on the fixed supporting piece, and two ends of the spring are respectively abutted against or connected with the limiting end and the rotating piece.
Optionally, in the urea mixer, the limiting head is screwed with the end of the fixed support.
Optionally, in the urea mixer described above, a bearing is provided between the fixed support member and the rotating member.
Optionally, in the urea mixer, the mixing pipe is an elbow pipe, a first pipe section and a second pipe section are respectively arranged on two sides of an included angle of the elbow pipe, and the first blade and the second blade are both arranged in the first pipe section;
the control system comprises a rotating shaft and a driver for controlling the rotating shaft to rotate, the driver is positioned outside the mixing pipe, wherein:
one end of the rotating shaft is connected with the rotating part and is coincided with the rotating central axis of the rotating part.
The other end of the rotating shaft extends out of the bent pipe from the included angle of the bent pipe so as to be connected with the driver, or the other end of the rotating shaft extends out of the bent pipe from the second pipe section so as to be connected with the driver.
According to the technical scheme, the urea mixer provided by the invention has a variable flow area, can play a role in exhaust heat management by controlling the number of the blades at low temperature, and improves NO at low temperature and low flowxThe conversion efficiency; simultaneously, this urea mixer can effectively increase the velocity of flow of air current at the mixing tube internal face, increase the velocity of flow of the fast urea dropping point position, promotes the mixture and the atomizing decomposition of urea solution and waste gas, improves the mixing uniformity, prevents that urea solution from appearing the problem of urea crystallization under low exhaust temperature low exhaust gas flow, effectively avoids the deposit of urea at the pipe wall.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic diagram of a static mixer of the prior art;
FIG. 2 is a schematic diagram showing an internal structure of a urea mixer according to a first embodiment of the present invention;
FIG. 3 is a schematic structural view of an intermediate support member provided with first blades according to a first embodiment of the present invention;
FIG. 4 is a schematic structural view of a rotating member provided with a second vane according to a first embodiment of the present invention;
FIG. 5 is a schematic view of a first embodiment of the present invention showing a urea mixer in which a second blade and a first blade are axially overlapped;
FIG. 6 is a schematic diagram of a urea mixer according to a first embodiment of the present invention, in which the second blades and the first blades are circumferentially staggered;
FIG. 7 is a schematic view showing the internal structure of a urea mixer according to a second embodiment of the present invention;
FIG. 8 is a schematic view of a second embodiment of the present invention showing a configuration in which the second and first blades are circumferentially staggered in a urea mixer;
FIG. 9 is a schematic view showing the internal structure of a urea mixer according to a third embodiment of the present invention;
FIG. 10 is a schematic view of a urea mixer according to a third embodiment of the present invention, in which the second blades and the first blades are circumferentially staggered;
FIG. 11 is a simplified cross-sectional view of a urea mixer according to a fourth embodiment of the present invention;
fig. 12 is a schematic structural diagram of an SCR system according to a fifth embodiment of the present invention;
fig. 13 is a control flowchart of an SCR system according to a fifth embodiment of the present invention.
Detailed Description
The invention discloses a urea mixer which can solve the problem of urea crystallization of an SCR system under low-load low exhaust temperature of a vehicle.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
First embodiment
A first embodiment of the present invention provides a urea mixer with exhaust heat management.
Referring to fig. 2 to 6, fig. 2 is a schematic diagram illustrating an internal structure of a urea mixer according to a first embodiment of the present invention, and fig. 3 is a schematic diagram illustrating a structure of an intermediate support provided with first blades according to the first embodiment of the present invention; FIG. 4 is a schematic structural view of a rotating member provided with a second vane according to a first embodiment of the present invention; fig. 5 is a schematic structural view of a urea mixer according to a first embodiment of the present invention in which a second blade and a first blade are axially overlapped, and fig. 6 is a schematic structural view of a urea mixer according to a first embodiment of the present invention in which a second blade and a first blade are circumferentially staggered.
The urea mixer provided by the first embodiment of the invention comprises a mixing pipe 1, a first blade 3, a second blade 2 and a control system. Wherein:
the first blade 3 and the second blade 2 are both arranged in the mixing pipe 1;
the control system is used for driving the second blade 2 to rotate from the first working position to the second working position, and is used for driving the second blade 2 to rotate from the second working position to the first working position;
when the second blade 2 is positioned at the first working position, the second blade is axially overlapped with the first blade 3, so that the flow area in the mixing pipe 1 is a first flow area; that is, at this time, in the axial direction of the mixing pipe 1, the second blade 2 is located forward or rearward of the first blade 3, and the blade positions thereof are completely overlapped; see in particular fig. 5;
when the second blade 2 is positioned at the second working position, the second blade and the first blade 3 are circumferentially staggered, so that the flow area in the mixing pipe 1 is a second flow area, and the second flow area is smaller than the first flow area; that is, at this time, the second blade 2 is positioned in front of or behind the first blade 3 in the axial direction of the mixing pipe 1 without overlapping the first blade 3, thereby reducing the flow area inside the mixing pipe 1; see in particular fig. 6.
It can be seen that the mixing pipe 1 of the urea mixer provided in the first embodiment of the present invention is provided with another set of blades, namely the second blades 2, in front of or behind (preferably behind) the first blades 3. In the working process of the engine, the second blade 2 can be controlled to have two working states according to the specific parameters of the SCR upstream temperature sensor T and the engine exhaust gas flow Q:
firstly, in most of the working process of the engine, the second blade 2 is in a first working position, namely a state a shown in fig. 5, at this time, the second blade 2 and the first blade 3 are overlapped back and forth in the axial direction of the mixing pipe 1, only the second blade 2 or only the first blade 3 plays a role of choked flow for the airflow in the mixing pipe 1, and the flow area in the mixing pipe 1 is large;
secondly, once the engine runs at a low exhaust temperature and a low exhaust gas flow rate, the control system controls the second blades 2 to rotate for a certain angle and then to be arranged in a staggered mode with the first blades 3, namely a state b shown in fig. 6. At this moment, first blade 3 and second blade 2 all play the choked flow effect to the air current in the mixing tube 1, and the flow area in the mixing tube 1 is less to the exhaust resistance increase plays the effect that dams, keeps warm, accelerates the gas flow and the rotation of urea mixing tube wall and blade simultaneously, in time takes away the urea liquid film of getting rid of in the wall position, further reduces urea crystallization risk, and improves the mixture of urea and air current.
It can be seen that the urea mixer provided by the first embodiment of the present invention has a variable flow area, and can achieve the exhaust heat management effect by controlling the number of the blades at low temperature, thereby improving NO at low temperature and low flow ratexThe conversion efficiency; meanwhile, the urea mixer can effectively increase the flow speed of the airflow on the inner wall surface of the mixing pipe 1 and increase the quick urinationThe air flow velocity of the urea drop point position promotes the mixing and the atomization decomposition of the urea solution and the waste gas, improves the mixing uniformity, prevents the problem of urea crystallization of the urea solution under the low exhaust temperature and the low waste gas flow, and effectively avoids the deposition of the urea on the pipe wall.
Specifically, referring to fig. 1, in the above urea mixer:
the first blades 3 are arranged in a plurality and are sequentially distributed along the circumferential direction, one end of each first blade 3 is fixedly connected with the fixed supporting piece 4, and the other end of each first blade 3 is fixedly connected with the inner wall of the mixing pipe 1;
the plurality of second blades 2 are arranged and are sequentially distributed along the circumferential direction, the connecting end of each second blade 2 is fixedly connected to the rotating piece 5, and the rotating piece 5 is coaxially sleeved on the fixed supporting piece 4 or coaxially sleeved in the fixed supporting piece 4;
the control system is connected with the rotating part 5 and used for driving the rotating part 5 to rotate to the first working position or the second working position around the central axis.
The control system comprises a pull rod 61 and a driver 7, wherein one end of the pull rod 61 is connected with the driver 7, and the other end of the pull rod 61 is connected with a rotating part connecting part 50 arranged on the rotating part 5; the driver 7 is arranged outside the mixing tube 1 and is used for driving the rotating piece 5 to rotate around the central axis through the pull rod 61 so as to control the rotating piece 5 to rotate to the first working position or the second working position with the second blade 2.
Preferably, the driver 7 is an electromagnetic valve, the fixed supporting member 4 is a central shaft, the rotating member 5 is a shaft sleeve adapted to the central shaft, the rotating member connecting portion 50 is a connecting rod disposed at a side end of the rotating member 5, a pull ring structure in clearance fit with the rotating member connecting portion 50 is disposed at an end of the pull rod 61, and the pull ring structure is an annular collar or a curved sleeve hook. Once the engine is running at low exhaust temperature and low exhaust gas flow rate, the solenoid valve controls the pull rod 61 to move outwards, so that the pull rod 61 pulls the rotating member 5 to rotate relative to the fixed support member 4, so as to move the second blade 2 from the first working position to the second working position, i.e. the second blade 2 and the third blade 3 change from the axially overlapped state a shown in fig. 5 to the circumferentially staggered state b shown in fig. 6.
However, the present invention is not limited to this, and the specific structural design of the components such as the driver 7, the fixed support member 4, and the rotating member 5 is not limited to this, and the skilled person can adopt various different schemes in the specific design. For example, in other specific embodiments, the following specific structural design may also be adopted:
the rotating part 5 adopts a central shaft structure, and the fixed supporting part 4 is designed into a shaft sleeve structure matched with the central shaft structure;
the rotating part connecting part 50 is of a hook structure, and the end part of the pull rod 61 connected with the rotating part connecting part 50 is also of a hook structure;
the end of the pull rod 61 and the rotating member connecting portion 50 are in a ball hinge structure.
In order to further optimize the above solution, in the preferred embodiment, the fixed supporting element 4 is a central shaft, the rotating element 5 is a sleeve fitted with the central shaft, and a guiding structure is arranged between the central shaft and the sleeve to guide the rotating element 5 during its rotation. For example:
as shown in fig. 3 and 4, the side wall of the fixed supporting member 4 is provided with a guide groove 41, the inner wall of the rotating member 5 is provided with a sliding protrusion 51 adapted to the guide groove 41, and the sliding protrusion 51 slides from the first position to the second position in the guide groove 41, so that the rotating member 5 rotates around the fixed supporting member 4 from the first working position to the second working position;
or, a sliding protrusion is arranged on the side wall of the fixed supporting part 4, a guide groove matched with the sliding protrusion is arranged on the inner wall of the rotating part 5, and the sliding protrusion slides from a first position to a second position in the guide groove, so that the rotating part 5 rotates around the fixed supporting part 4 from the first working position to the second working position;
or, a guide groove is arranged on the side wall of the fixed supporting part 4, a ball is nested on the inner wall of the rotating part 5, the ball slides from a first position to a second position in the guide groove, and then the rotating part 5 rotates around the fixed supporting part 4 from the first working position to the second working position;
or, a guide groove is formed in the inner wall of the rotating member 5, a ball is nested on the side wall of the fixed supporting member 4, the ball slides from a first position to a second position in the guide groove, and then the rotating member 5 rotates around the fixed supporting member 4 from the first working position to the second working position.
Specifically, in the urea mixer, when the second blade 2 and the first blade 3 are staggered circumferentially, the gap between the adjacent first blade 3 and second blade 2 is larger than zero, so that the mixing pipe 1 has a suitable flow area, and the operating condition requirements of the engine during operation at low exhaust temperature and low exhaust gas flow are met.
Specifically, in the urea mixer, the first blades 3 and the second blades 2 are equal in number and shape. For example, the first blade 3 and the second blade 2 are respectively strip-shaped fan-shaped blades; the first blade 3 and the second blade 2 are provided with three, four, five or six, respectively. However, the present invention is not limited to this, and in the specific implementation process, the number, angle, length and specific shape of the vanes according to the actual requirements of the engines with different displacement and different purposes can be designed to reasonably distribute the exhaust flow.
Second embodiment
A second embodiment of the invention provides a urea mixer with exhaust heat management. The urea mixer is additionally provided with a spring and a limit end head on the basis of the urea mixer provided by the first embodiment of the invention.
Referring specifically to fig. 7 and 8, fig. 7 is a schematic diagram illustrating an internal structure of a urea mixer according to a second embodiment of the present invention; FIG. 8 is a schematic diagram of a second embodiment of the present invention, showing a second blade and a first blade staggered circumferentially in a urea mixer.
Specifically, in this urea mixer, fixed support 4 is the center pin, rotates piece 5 for the axle sleeve with the center pin adaptation, and the cover is equipped with spring 8 on fixed support 4 to install spacing end 9. Wherein:
the limiting end 9 is fixedly connected with the fixed supporting piece 4, and the limiting end 9 and the first blade 3 are respectively positioned at two sides of the rotating piece 5;
the spring 8 is sleeved on the fixed supporting piece 4, two ends of the spring 8 are respectively abutted or connected with the limiting end 9 and the rotating piece 5, and the spring 8 is used for providing restoring force for the rotating piece 5.
When the engine runs at low exhaust temperature and low exhaust gas flow, the control system controls the rotating part 5 to rotate relative to the fixed support part 4, so that the second blade 2 moves from the first working position to the second working position, namely the second blade 2 and the third blade 3 change from an axially overlapped state to a circumferentially staggered state shown in fig. 8, the effect of exhaust heat management is achieved, and NO at low temperature and low flow is improvedxThe conversion efficiency.
Preferably, the limit stop 9 is screwed to the end of the fixed support 4. But not limited to, the spacing end 9 and the fixed support 4 may be connected by welding or other methods, or the spacing end 9 and the fixed support 4 may be made into an integral structural member.
Third embodiment
A third embodiment of the present invention provides a urea mixer with exhaust heat management. Referring specifically to fig. 9 and 10, fig. 9 is a schematic diagram illustrating an internal structure of a urea mixer according to a third embodiment of the present invention; FIG. 10 is a schematic diagram of a urea mixer according to a third embodiment of the present invention, in which the second blades and the first blades are circumferentially staggered.
The urea mixer according to the third embodiment of the present invention is different from the urea mixer according to the first embodiment of the present invention in that: a bearing is provided between the fixed support member 4 and the rotating member 5. The guide structure, i.e., the guide groove and the guide projection, the guide groove and the ball described in the first embodiment, provided between the fixed supporting member 4 and the rotating member 5 can be eliminated.
The third embodiment of the present invention provides a urea mixer that operates in the same manner as the urea mixer of the first embodiment.
Fourth embodiment
A fourth embodiment of the present invention provides a urea mixer with exhaust heat management function, and referring to fig. 11 in particular, fig. 11 is a simplified cross-sectional view of a urea mixer provided by the fourth embodiment of the present invention.
The urea mixer according to the fourth embodiment of the present invention is different from the urea mixer according to the first embodiment of the present invention in that:
the mixing pipe 1 is a bent pipe, a first pipe section 11 and a second pipe section 12 are respectively arranged on two sides of an included angle of the bent pipe, and the first blade 3 and the second blade 2 are both arranged in the first pipe section 11;
the control system comprises a rotating shaft 62 and a driver 7 for controlling the rotating shaft 62 to rotate, the driver 7 is positioned outside the mixing pipe 1, wherein:
one end of the rotating shaft 62 is connected to the rotating member 5 and coincides with the rotational center axis of the rotating member 5.
The other end of the rotating shaft 62 extends out of the elbow from the included angle of the elbow to be connected with the driver 7, or the other end of the rotating shaft 62 extends out of the elbow from the second pipe section 12 to be connected with the driver 7.
In particular, the actuator 7 may be a solenoid valve, or other rotary actuator.
The fourth embodiment of the present invention provides a urea mixer similar to the urea mixer of the first embodiment in operation: when the engine runs at low exhaust temperature and low exhaust gas flow, the driver 7 controls the rotating part 5 to rotate relative to the fixed supporting part 4 through the rotating shaft 6, so that the second blade 2 moves from the first working position to the second working position, namely the second blade 2 and the third blade 3 change from an axially overlapped state to a circumferentially staggered state, the effect of exhaust heat management is achieved, and NO under low temperature and low flow is improvedxThe conversion efficiency.
Fifth embodiment
A fifth embodiment of the present invention provides an SCR system.
Referring to fig. 12 and 13, fig. 12 is a schematic structural diagram of an SCR system according to a fifth embodiment of the present invention, and fig. 13 is a control flowchart of the SCR system according to the fifth embodiment of the present invention.
A fifth embodiment of the present invention provides an SCR system in which the urea mixer described in any of the above embodiments is used.
Referring to fig. 12, the SCR system mainly includes a urea supply unit 11, a urea tank 13, a urea injection unit 14, a urea level temperature sensor 12, and an upstreamTemperature sensor 14, catalyst 15, NOx Sensor 17, an engine ECU (Electronic Control Unit, also called "traveling computer", "vehicle-mounted computer", etc.), a urea aqueous solution quality sensor, and NH3A sensor in which a urea mixer provided in the first embodiment of the present invention is provided between the urea injection unit 14 and the catalyst 15.
Referring to fig. 13, the control method of the SCR system mainly includes the following steps:
during most of the engine operation, the second blade 2 and the first blade 3 are in tandem, i.e. in the condition shown in fig. 5;
after the ECU receives a temperature measured value T of an upstream temperature sensor in the SCR system, whether the temperature measured value T is smaller than a preset temperature value T or not is judgedL(ii) a After the ECU receives the exhaust gas flow value Q, whether the exhaust gas flow value Q is smaller than a preset flow value Q is judgedL；
If T is less than or equal to TL，Q≤QLThe control system controls the second blade 2 to rotate for a certain angle and then to be arranged in a staggered way with the first blade 3, namely the state in fig. 6;
under other engine working conditions, the second blade 2 and the first blade 3 are in a front-back overlapping state.
Therefore, the urea mixer and the SCR system provided by the invention can realize the modular design of the mixer structure, and when the urea mixer and the SCR system are applied to engines with different discharge capacities, the structure can be finely adjusted according to the operation working conditions of the engines, so that the reasonable matching with the engines is realized. The urea mixer and the SCR system provided by the invention are expected to be applied to post-treatment systems of the national six and more strict.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. A urea mixer, comprising a mixing tube (1), a first blade (3), a second blade (2), a control system, wherein:
the first blade (3) and the second blade (2) are both arranged in the mixing pipe (1);
the control system is used for driving the second blade (2) to rotate from a first working position to a second working position, and is used for driving the second blade (2) to rotate from the second working position to the first working position;
when the second blade (2) is positioned at the first working position, the second blade is axially overlapped with the first blade (3) so that the flow area in the mixing pipe (1) is a first flow area;
when the second blade (2) is positioned at the second working position, the second blade and the first blade (3) are circumferentially staggered, so that the flow area in the mixing pipe (1) is a second flow area, and the second flow area is smaller than the first flow area;
the plurality of first blades (3) are sequentially arranged along the circumferential direction, one end of each first blade (3) is fixedly connected with the fixed supporting piece (4), and the other end of each first blade is fixedly connected with the inner wall of the mixing pipe (1);
the second blades (2) are arranged in a plurality of groups and are sequentially distributed along the circumferential direction, the connecting end of each second blade (2) is fixedly connected to the rotating piece (5) respectively, and the rotating piece (5) is coaxially sleeved on the fixed supporting piece (4) or coaxially sleeved in the fixed supporting piece (4);
the control system is connected with the rotating part (5) and is used for driving the rotating part (5) to rotate around a central axis so as to drive the second blade (2) to rotate to the first working position or the second working position through the rotating part (5);
be provided with on the rotation piece (5) and rotate a piece connecting portion (50), control system includes pull rod (61) and driver (7), wherein:
two ends of the pull rod (61) are respectively connected with the driver (7) and the rotating piece connecting part (50);
the driver (7) is arranged on the outer side of the mixing pipe (1) and is used for driving the rotating piece (5) to rotate through the pull rod (61).
2. Urea mixer according to claim 1, characterized in that the driver (7) is a solenoid valve.
3. Urea mixer according to claim 1, characterized in that the rotor connection (50) is a connecting rod arranged at the side end of the rotor (5);
the end part of the pull rod (61) is provided with a pull ring structure in clearance fit with the connecting rod, and the pull ring structure is an annular ferrule or a bent ferrule hook.
4. Urea mixer according to any of the claims 1-3, characterized in that the stationary support part (4) is a central shaft and the rotating part (5) is a sleeve adapted to the central shaft, wherein:
a guide groove (41) is formed in the side wall of the fixed supporting part (4), a sliding protrusion (51) matched with the guide groove (41) is arranged on the inner wall of the rotating part (5), and the sliding protrusion (51) slides from a first position to a second position in the guide groove (41), so that the rotating part (5) rotates around the fixed supporting part (4) from the first working position to the second working position;
or, a sliding protrusion is arranged on the side wall of the fixed supporting part (4), a guide groove matched with the sliding protrusion is arranged on the inner wall of the rotating part (5), and the sliding protrusion slides from a first position to a second position in the guide groove, so that the rotating part (5) rotates around the fixed supporting part (4) from the first working position to the second working position;
or, a guide groove is formed in the side wall of the fixed supporting part (4), a ball is nested on the inner wall of the rotating part (5), and the ball slides from a first position to a second position in the guide groove, so that the rotating part (5) rotates around the fixed supporting part (4) from the first working position to the second working position;
or, be provided with the guide way on the inner wall of rotation piece (5), the nestification is provided with the ball on the lateral wall of fixed support piece (4), the ball is in slide to the second position by the primary importance in the guide way, then rotation piece (5) wind fixed support piece (4) rotate to the second operating position by the primary importance.
5. Urea mixer according to claim 4, characterized by further comprising a spring (8) and a limit tip (9);
the limiting end (9) is fixedly connected with the fixed supporting piece (4), and the limiting end (9) and the first blade (3) are respectively positioned on two sides of the rotating piece (5);
the spring (8) is sleeved on the fixed supporting piece (4), and two ends of the spring (8) are respectively abutted or connected with the limiting end (9) and the rotating piece (5).
6. Urea mixer according to claim 5, characterized in that the limiting head (9) is screwed to the end of the fixed support (4).
7. Urea mixer according to any of the claims 1-3, characterized in that a bearing is arranged between the stationary support part (4) and the rotating part (5).
8. A urea mixer, comprising a mixing tube (1), a first blade (3), a second blade (2), a control system, wherein:
the first blade (3) and the second blade (2) are both arranged in the mixing pipe (1);
the control system is used for driving the second blade (2) to rotate from a first working position to a second working position, and is used for driving the second blade (2) to rotate from the second working position to the first working position;
when the second blade (2) is positioned at the first working position, the second blade is axially overlapped with the first blade (3) so that the flow area in the mixing pipe (1) is a first flow area;
when the second blade (2) is positioned at the second working position, the second blade and the first blade (3) are circumferentially staggered, so that the flow area in the mixing pipe (1) is a second flow area, and the second flow area is smaller than the first flow area;
the plurality of first blades (3) are sequentially arranged along the circumferential direction, one end of each first blade (3) is fixedly connected with the fixed supporting piece (4), and the other end of each first blade is fixedly connected with the inner wall of the mixing pipe (1);
the second blades (2) are arranged in a plurality of groups and are sequentially distributed along the circumferential direction, the connecting end of each second blade (2) is fixedly connected to the rotating piece (5) respectively, and the rotating piece (5) is coaxially sleeved on the fixed supporting piece (4) or coaxially sleeved in the fixed supporting piece (4);
the control system is connected with the rotating part (5) and is used for driving the rotating part (5) to rotate around a central axis so as to drive the second blade (2) to rotate to the first working position or the second working position through the rotating part (5);
the mixing pipe (1) is a bent pipe, a first pipe section (11) and a second pipe section (12) are respectively arranged on two sides of an included angle of the bent pipe, and the first blade (3) and the second blade (2) are both arranged in the first pipe section (11);
the control system comprises a rotating shaft (62) and a driver (7) for controlling the rotating shaft (62) to rotate, wherein the driver (7) is positioned outside the mixing pipe (1), and the control system comprises:
one end of the rotating shaft (62) is connected with the rotating piece (5) and is superposed with the rotating central axis of the rotating piece (5),
the other end of pivot (62) by the contained angle department of return bend stretches out outside the return bend in order to be connected with driver (7), perhaps, the other end of pivot (62) by second pipe section (12) stretch out outside the return bend with driver (7) are connected.
CN202011341291.2A 2020-11-25 2020-11-25 Urea mixer Active CN112302767B (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4353848A (en) * 1980-07-25 1982-10-12 Carsten Earl D Fuel/air metering apparatus
CN101501308A (en) * 2005-06-15 2009-08-05 排放控制技术有限公司 Swirl-stabilized burner for thermal management of exhaust system and associated method
WO2013088923A1 (en) * 2011-12-12 2013-06-20 いすゞ自動車株式会社 Internal combustion engine and control method for same
DE102012008556A1 (en) * 2012-04-27 2013-10-31 Iav Gmbh Ingenieurgesellschaft Auto Und Verkehr Device for exhaust gas aftertreatment of exhaust gas mass flow in exhaust gas line, has injector which is arranged in exhaust gas line for supplying reducing agent in exhaust gas mass flow, where exhaust gas line segment has inlet
WO2016024207A1 (en) * 2014-08-13 2016-02-18 Officine Metallurgiche G. Cornaglia S.P.A. Dynamic mixer with movable vanes for exhaust gases of i.c. engines
DE102017201719A1 (en) * 2017-02-03 2018-08-09 Bayerische Motoren Werke Aktiengesellschaft Device for mixing a reducing agent with an exhaust gas of an internal combustion engine

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012047119A (en) * 2010-08-27 2012-03-08 Mitsubishi Motors Corp Exhaust emission control device of internal combustion engine

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4353848A (en) * 1980-07-25 1982-10-12 Carsten Earl D Fuel/air metering apparatus
CN101501308A (en) * 2005-06-15 2009-08-05 排放控制技术有限公司 Swirl-stabilized burner for thermal management of exhaust system and associated method
WO2013088923A1 (en) * 2011-12-12 2013-06-20 いすゞ自動車株式会社 Internal combustion engine and control method for same
DE102012008556A1 (en) * 2012-04-27 2013-10-31 Iav Gmbh Ingenieurgesellschaft Auto Und Verkehr Device for exhaust gas aftertreatment of exhaust gas mass flow in exhaust gas line, has injector which is arranged in exhaust gas line for supplying reducing agent in exhaust gas mass flow, where exhaust gas line segment has inlet
WO2016024207A1 (en) * 2014-08-13 2016-02-18 Officine Metallurgiche G. Cornaglia S.P.A. Dynamic mixer with movable vanes for exhaust gases of i.c. engines
DE102017201719A1 (en) * 2017-02-03 2018-08-09 Bayerische Motoren Werke Aktiengesellschaft Device for mixing a reducing agent with an exhaust gas of an internal combustion engine

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