CN212027913U

CN212027913U - U-shaped after-treatment device of diesel engine

Info

Publication number: CN212027913U
Application number: CN202020645181.4U
Authority: CN
Inventors: 谈秉乾; 吕柏禹; 袁可平; 何瑞
Original assignee: Wuxi Henghe Ep Tech Co ltd
Current assignee: Wuxi Henghe Ep Tech Co ltd
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2020-11-27
Anticipated expiration: 2030-04-24

Abstract

The utility model belongs to the technical field of engine exhaust aftertreatment technique and specifically relates to a diesel engine U type aftertreatment device. The device comprises a second cylinder and a first cylinder which are arranged in parallel up and down, wherein a DOC carrier, a DPF carrier and a baffle are sequentially arranged in an inner cavity of the first cylinder along the exhaust flowing direction, a nozzle mounting seat is welded on the side surface of the air inlet end of a clam shell, a urea nozzle is detachably connected to the nozzle mounting seat through a connecting piece, the urea nozzle extends into the clam shell, and the urea nozzle faces to the position of the air outlet of an exhaust main runner on the baffle; and a plurality of SCR carriers are sequentially arranged in the inner cavity of the second cylinder along the exhaust flowing direction. The utility model discloses with DOC carrier and DPF carrier setting in the below of SCR carrier, the second barrel that sets up the SCR carrier can be in same horizontal plane with whole car girder, and the first barrel that sets up DOC carrier and DPF carrier is located whole car girder below, reduces the required installation space of diesel engine U type aftertreatment device by a wide margin.

Description

U-shaped after-treatment device of diesel engine

Technical Field

The utility model belongs to the technical field of engine exhaust aftertreatment technique and specifically relates to a diesel engine U type aftertreatment device.

Background

The packaging structure widely adopted by the diesel engine aftertreatment system adopting the technical route of the oxidation catalytic converter (DOC), the particulate trap (DPF), the selective catalytic reduction converter (SCR) is mainly a straight cylinder type, a box type and the like. At present, a straight-cylinder type catalyst packaging structure is mostly adopted in a diesel engine with medium and small discharge capacity, the straight-cylinder type catalyst packaging structure is hoisted below a girder of a whole vehicle through a hanging bracket and is placed in parallel with a transmission shaft, and the catalyst is high in ground clearance but requires a certain axial space. The box-type catalyst converter packaging structure used by the medium-large diesel engine has a larger volume, is arranged on the side surface of a girder of the whole vehicle through a suspension, and is mostly arranged between a second shaft and a third shaft of the whole vehicle. Box catalyst converter packaging structure ground clearance is low, for guaranteeing that the mixed effect reduces the crystallization risk, box catalyst converter packaging structure's mixed structure adopts urea efflux and engine exhaust to mix on same horizontal plane more, leads to exhaust passage to have a lot of to turn back, and this will increase exhaust backpressure, causes certain influence to the engine performance.

At present, the outlet direction of most of the whole vehicle superchargers is set to face the tail direction of the vehicle, the corresponding inlet ends of the aftertreatment systems are arranged above the catalysts, but part of the engines also need the outlet of the superchargers to face downwards in consideration of the arrangement of the engine body. The reason why the catalyst is difficult to be disposed above the inlet is that the outlet of the supercharger is disposed downward is: the exhaust pipeline after the supercharger comes out can enter the catalytic converter after being bent for multiple times (generally considering position limit values of a girder, a tire, a baffle plate and the like of the whole vehicle), so that exhaust back pressure is increased, arrangement difficulty is caused, and interference is easily caused.

In order to match an engine with a supercharger outlet arranged downwards, the structure of a catalyst is compact as much as possible, the pressure loss of an after-treatment system to engine exhaust is reduced, and the oil consumption is reduced, a U-shaped after-treatment device of a diesel engine catalytic exhaust diesel engine with a DOC and a DPF arranged below is required to be developed.

SUMMERY OF THE UTILITY MODEL

The applicant provides a diesel engine U type aftertreatment device rational in infrastructure to the shortcoming among the above-mentioned prior production technique, set up DOC carrier and DPF carrier in the below of SCR carrier, the second barrel that sets up the SCR carrier can be in same horizontal plane with whole car girder, the first barrel that sets up DOC carrier and DPF carrier is located whole car girder below, the blast pipe is connected with diesel engine U type aftertreatment device from whole car girder below, can satisfy the booster export and set up the aftertreatment installation demand for engine down, reduce installation space by a wide margin.

The utility model discloses the technical scheme who adopts as follows:

a U-shaped aftertreatment device of a diesel engine comprises a second cylinder and a first cylinder which are arranged in parallel from top to bottom, wherein the air outlet end of the first cylinder is connected with the air inlet end of a clam shell, the air outlet end of the clam shell is connected with the air inlet end of the second cylinder, a bottom plate is arranged in the middle of the end face of the clam shell, which is connected with the first cylinder and the second cylinder, two ends of the bottom plate are respectively in sealing connection with the first cylinder and the second cylinder, the air inlet end of the first cylinder is provided with a front end cover, the center of the front end cover is provided with a catalyst inlet, a DOC carrier, a DPF carrier and a baffle are sequentially arranged in the inner cavity of the first cylinder along the exhaust flowing direction, and an exhaust;

a nozzle mounting seat is welded on the side face of the air inlet end of the clam shell, a urea nozzle is detachably connected to the nozzle mounting seat through a connecting piece, the urea nozzle extends into the clam shell, and the urea nozzle faces the position of the air outlet end of the main air exhaust channel on the baffle; the clamshell is internally provided with a guide plate with an arc-shaped structure, the baffle is provided with a plurality of guide plate jacks, one side of the guide plate is welded in the guide plate jack of the baffle, the other side of the guide plate is inserted into the jack of the bottom plate and welded, the guide plate is positioned on one side of a urea jet flow path of the urea nozzle, and a urea jet flow boundary line of the urea nozzle is tangent to the guide plate; a plurality of sieve plates with arc structures are arranged in the clam shell, the sieve plates are positioned between the guide plate and the inner side wall of the lower portion of the clam shell, a plurality of sieve plate insertion holes are formed in the baffle, the sieve plate insertion holes are distributed along the edge of the exhaust main flow channel, one side of each sieve plate is inserted into the sieve plate insertion hole of the baffle and welded, the other side of each sieve plate is inserted into the insertion hole of the bottom plate and welded, and the sieve plates are positioned on a urea jet flow path of the urea nozzle;

a plurality of SCR carriers are sequentially arranged in the inner cavity of the second cylinder along the exhaust flowing direction, the side surface of the air outlet end of the second cylinder is welded with an exhaust tail pipe, one end of the exhaust tail pipe is provided with an exhaust outlet, and the air inlet end of the other end of the exhaust tail pipe extends into the second cylinder; the exhaust outlet is positioned outside the second cylinder, the air inlet end of the exhaust tail pipe is positioned at the downstream of the SCR carriers, and the surface of the air inlet end of the exhaust tail pipe is provided with a plurality of exhaust sieve holes; the air inlet end of the second cylinder is provided with a rotational flow plate, the rotational flow plate is perpendicular to the direction of air flow in the second cylinder, the rotational flow plate is provided with a plurality of rotational flow blades which are obliquely arranged, and the plurality of rotational flow blades are uniformly distributed along the circumferential direction;

a guide pore plate is fixedly arranged in the middle of the clam shell, the side surface of the guide pore plate is inserted into an insertion hole in the side wall of the clam shell and is welded, and a plurality of guide flow holes are uniformly formed in the guide pore plate; the guide pore plate is of a circular arc plate body structure, and the circular arc convex surface of the guide pore plate faces the outlet end of the airflow guide channel formed by the guide plate and the inner side wall of the lower part of the clam shell.

Furthermore, the cross section of the front end cover is gradually enlarged from the side where the catalyst inlet is arranged to the other side.

Furthermore, a plurality of flow holes are formed in the baffle, and the area of the flow holes which are farther away from the exhaust main flow channel in the plurality of flow holes is smaller.

Furthermore, the baffle is provided with a circle of baffle flanging structure along the outer edge.

Furthermore, the included angle between the center line of the urea jet of the urea nozzle and the connecting line of the SCR carrier center and the DPF carrier center is alpha, and the angle range of the alpha is 15-45 degrees.

Furthermore, the urea nozzle is obliquely arranged towards the exhaust main flow passage on the baffle, the included angle between the urea jet flow direction of the urea nozzle and the arrangement direction of the clam shell surface facing the end surface of the first cylinder body is beta, and the angle range of the beta is 5-10 degrees.

Furthermore, be equipped with the guide vane that a plurality of slopes set up on the sieve, every guide vane corresponds the projection position on the sieve and is equipped with the sieve hole, and the same size of sieve hole and guide vane structure equals.

Furthermore, every whirl blade is equipped with the blade hole in the projection position that corresponds on the whirl board, and the same size of blade hole and whirl blade structure equals, is equipped with a plurality of whirl through holes on the whirl board, and a plurality of whirl through holes are equipped with central through hole along whirl board circumferencial direction evenly distributed, whirl board central point.

Furthermore, the swirl plate is provided with a swirl plate flanging structure along the edge of the outer ring.

The utility model has the advantages as follows:

the utility model has compact and reasonable structure and convenient operation, the DOC carrier and the DPF carrier are arranged below the SCR carrier, the second cylinder body provided with the SCR carrier can be positioned on the same horizontal plane with the girder of the whole vehicle, the first cylinder body provided with the DOC carrier and the DPF carrier is positioned below the girder of the whole vehicle, the exhaust pipe is connected with the U-shaped post-treatment device of the diesel engine from the lower part of the girder, the post-treatment installation requirement of the engine with the outlet of the supercharger arranged downwards can be met, and the installation space required by the U-shaped post-treatment device of the diesel engine is greatly reduced; a baffle is arranged at the downstream of the DPF carrier, an exhaust main runner is arranged on the baffle, most of engine exhaust passes through the main runner, so that the engine exhaust is in full contact with the urea jet flow as far as possible, and the heat of the engine exhaust drives the urea to be pyrolyzed and hydrolyzed; the baffle is provided with a plurality of flow holes, the farther the flow holes are from the exhaust main flow channel, the smaller the area is, the larger the exhaust flow speed at the flow holes is, so that the gas collision at the position, far away from the exhaust main flow channel, on the baffle is reduced, and the exhaust pressure loss is reduced; the urea jet flow direction of the urea nozzle and the arrangement direction of the clam shell facing the end face of the first cylinder form an included angle beta, the included angle beta can enable the urea solution sprayed by the urea nozzle to be opposite to the exhaust direction of an engine, and the urea solution sprayed by the urea nozzle can be prevented from being directly impacted on the inner wall surface of the clam shell by the exhaust of the engine flowing out of the baffle as much as possible; the guide plate arranged in the clam shell can gradually change the exhaust flow direction, so that the urea solution is prevented from being directly sprayed on the guide plate to form a liquid film, and the crystallization risk is reduced; a sieve plate is arranged in the clam shell and can guide the mixed gas into the second cylinder; the mist enters the upper portion of the clam shell after being divided into multiple paths through the sieve plates at the lower portion of the clam shell, and then the main airflow is dispersed through the guide hole plates, so that the airflow entering the left side and the right side of the cyclone plate can be uniformly distributed.

Drawings

Fig. 1 is a front view of the present invention.

Fig. 2 is a rear view of the present invention.

Fig. 3 is a rear half-section view of the utility model.

Fig. 4 is a half-sectional view of the clam shell of the present invention.

Fig. 5 is a perspective view of the present invention with the clam shell side plate removed.

Fig. 6 is a structural diagram of the baffle of the present invention.

Fig. 7 is a structural diagram of the sieve plate of the present invention.

Fig. 8 is a structural diagram of the whirl plate of the present invention.

Fig. 9 is a structural diagram of the guide orifice plate of the present invention.

Wherein: 1. a first cylinder; 2. a second cylinder; 3. clam shells; 4. a front end cover; 6. a DOC carrier; 7. A DPF carrier; 8. an SCR carrier; 9. a catalyst air inlet; 10. a baffle plate; 11. an exhaust main flow passage; 12. A flow-through hole; 13. a baffle flanging structure; 14. a nozzle mount; 15. a guide plate; 16. a sieve plate; 17. A guide blade; 18. sieve plate holes; 19. a tail pipe; 20. an air discharge sieve pore; 21. a swirl plate; 22. a swirl vane; 23. a rotational flow circulation hole; 24. a central flow aperture; 25. a blade hole; 26. a flange structure of the rotational flow plate; 27. a guide orifice plate; 28. a pilot flow hole; 29. an exhaust outlet; 30. a base plate; 31. a sieve plate jack; 32. and a guide plate insertion hole.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.

As shown in figures 1-3, the utility model discloses mainly include upper and lower parallel arrangement's second barrel 2 and first barrel 1, the clam shell 3 inlet end is connected to first barrel 1 end of giving vent to anger, and clam shell 3 end of giving vent to anger is connected second barrel 2 inlet end. The middle part of the end face of the clam shell 3 connected with the first cylinder 1 and the second cylinder 2 is provided with a bottom plate 30, and two ends of the bottom plate 30 are respectively connected with the first cylinder 1 and the second cylinder 2 in a sealing way.

As shown in figures 1-3, a front end cover 4 is arranged at the air inlet end of the first cylinder 1, a catalyst air inlet 9 is arranged at the center of the front end cover 4, and when the air catalytic converter is used, the catalyst air inlet 9 of the front end cover 4 is detachably connected with an engine exhaust pipe.

As shown in fig. 1 to 3, in order to facilitate the diffusion of the engine exhaust entering the first cylinder 1, the cross-sectional size of the front end cover 4 gradually increases from the side where the catalyst inlet 9 is disposed to the other side, and the exhaust of the engine exhaust pipe gradually diffuses from the small-diameter end to the large-diameter end after entering the front end cover 4, thereby improving the uniformity of the airflow diffusion.

As shown in fig. 3, a DOC carrier 6, a DPF carrier 7, and a baffle 10 are sequentially disposed in an inner cavity of the first cylinder 1 along an exhaust gas flow direction.

As shown in fig. 6, the baffle 10 is provided with an exhaust main flow passage 11, and the area of the exhaust main flow passage 11 is equal to 1/3 of the cross section of the first cylinder 1. The baffle plate 10 is provided with a plurality of flow holes 12, and the area of the flow hole 12 which is farther from the exhaust main flow passage 11 among the plurality of flow holes 12 is smaller. Baffle 10 is equipped with a round baffle flange structure 13 along the outward flange, and baffle flange structure 13 can improve the structural strength of baffle 10.

After the engine exhaust gas passes through the DOC carrier 6 and the DPF carrier 7, the gas flow flowing out of the DPF carrier 7 is approximately considered to be uniformly distributed at the end surfaces due to gas diffusion and the dispersing action of the porous medium on the gas flow. However, due to the arrangement position of the urea nozzle, the engine exhaust gas flowing out of the DPF carrier 7 is required to flow through the injection range of the urea nozzle completely, so that the engine exhaust gas is in full contact with the urea jet flow as much as possible, and the heat of the engine exhaust gas drives the urea to be pyrolyzed and hydrolyzed. Therefore, a baffle 10 is arranged at the downstream of the DPF carrier 7, an exhaust main flow passage 11 is arranged on the baffle 10, most of the engine exhaust gas passes through the exhaust main flow passage 11, and the gas flow area at the baffle 10 is suddenly reduced to cause the exhaust gas flow speed to be rapidly increased. However, the air flow at the air outlet end of the DPF carrier 7 collides with the body of the baffle 10 to bring about a certain exhaust pressure drop. In order to reduce the pressure loss, a plurality of flow holes 12 are arranged on the baffle plate 10, the area of the flow holes 12 is smaller as the distance from the exhaust main flow channel 11 is larger, the exhaust flow speed at the flow holes 12 is larger, and therefore the gas collision at the position, far away from the exhaust main flow channel 11, on the baffle plate 10 is reduced, and the exhaust pressure loss is reduced. Meanwhile, the urea solution sprayed from the urea nozzle positioned at the downstream of the baffle plate 10 is easy to diffuse to the flow dead angle formed by the baffle plate 10 and the guide plate 15, and the arrangement of the flow holes 12 on the baffle plate 10 can lead the exhaust gas to take away the urea solution diffused to the position, thereby reducing the crystallization risk.

As shown in fig. 2 and 4, a nozzle mounting seat 14 is welded on the side surface of the air inlet end of the clam shell 3, a urea nozzle is detachably connected on the nozzle mounting seat 14 through a connecting piece, the urea nozzle extends into the clam shell 3 and faces to the position of the air outlet end of the main air exhaust channel 11 on the baffle plate 10. The included angle between the center line of the urea jet of the urea nozzle and the connecting line of the center of the SCR carrier 8 and the center of the DPF carrier 7 is alpha, the size of the alpha is determined according to the size of the carrier and the jet taper angle of the nozzle, and the angle range of the alpha is 15-45 degrees.

As shown in fig. 4 and 5, a guide plate 15 having a circular arc structure is provided in the clam shell 3. As shown in fig. 6, the baffle 10 is provided with a plurality of guide plate insertion holes 32, and the guide plate insertion holes 32 are used for connecting the guide plates 15. The guide plate 15 is welded at one side to the guide plate insertion hole 32 of the baffle plate 10 and at the other side to the insertion hole of the base plate 30 and welded. The guide plate 15 is located on the urea jet path side of the urea nozzle. The urea jet boundary line of the urea nozzle is tangent to the guide plate 15, and the guide plate 15 can gradually change the exhaust flow direction, so that the urea solution is prevented from being directly sprayed on the guide plate 15 to form a liquid film, and the crystallization risk is reduced.

As shown in fig. 2, in order to minimize the direct impact of the urea solution sprayed from the urea nozzle on the inner wall surface of the clam shell 3 by the engine exhaust flowing out of the baffle 10, the urea nozzle is obliquely arranged toward the exhaust main flow passage 11 on the baffle 10, and the included angle between the urea jet direction of the urea nozzle and the arrangement direction of the clam shell 3 facing the end surface of the first cylinder 1 is beta, the angle range of beta is 5 to 10 degrees, the included angle beta can enable the urea solution sprayed from the urea nozzle to be opposite to the engine exhaust direction, and the direct impact of the urea solution sprayed from the urea nozzle on the inner wall surface of the clam shell 3 by the engine exhaust flowing out of the baffle 10 can be minimized.

In operation, engine exhaust flows from the first cylinder 1 into the clam shell 3, and the urea nozzle on the side of the clam shell 3 sprays a urea jet into the engine exhaust in the clam shell 3. After the engine exhaust and the urea jet are contacted, the engine exhaust and the urea jet form a mixed gas to start a reaction process. As shown in fig. 4 and 5, in order to change the direction of the mixture gas and make the mixture gas move upwards into the second cylinder 2, a plurality of sieve plates 16 with circular arc structures are arranged in the clam shell 3, and the sieve plates 16 are positioned between the guide plate 15 and the inner side wall of the lower part of the clam shell 3.

As shown in fig. 6, the baffle 10 is provided with a plurality of sieve plate insertion holes 31, the sieve plate insertion holes 31 are used for connecting sieve plates, and the plurality of sieve plate insertion holes 31 are distributed along the edge of the exhaust main flow channel 11. As shown in fig. 4 and 5, the sieve plate 16 is inserted into the sieve plate insertion hole 31 of the baffle plate 10 on one side and welded, and is inserted into the insertion hole of the base plate 30 on the other side and welded, and the sieve plate 16 is positioned on the urea jet flow path of the urea nozzle.

As shown in fig. 7, a plurality of guide vanes 17 are obliquely arranged on the screen plate 16, a screen plate hole 18 is arranged at a projection position of each guide vane 17 on the screen plate 16, and the screen plate hole 18 and the guide vane 17 have the same structure and the same size. Guide vane 17 on sieve 16 can further change the air current direction for the mist is to the removal of second barrel 2 direction, avoids changing the loss of pressure that the air current direction brought by a wide margin simultaneously, and guide vane 17 corresponds sieve hole 18 can let the urea solution more broken.

As shown in fig. 3, a plurality of SCR carriers 8 are sequentially disposed in the inner cavity of the second cylinder 2 along the exhaust flow direction, and a tail pipe 19 is welded to the end face of the outlet end of the second cylinder 2. The tail pipe 19 is provided with an exhaust outlet 29 at one end, and the exhaust outlet 29 is positioned outside the second cylinder 2. The inlet end of the other end of the tail pipe 19 extends into the second cylinder 2, and the inlet end of the tail pipe 19 is located at the downstream of the plurality of SCR carriers 8. The inlet end surface of the tail pipe 19 is provided with a plurality of exhaust holes 20. The air inlet end of the second cylinder 2 is provided with a rotational flow plate 21, and the rotational flow plate 21 is perpendicular to the air flow direction in the second cylinder 2.

As shown in fig. 8, the swirl plate 21 is provided with a plurality of swirl blades 22 arranged obliquely, and the plurality of swirl blades 22 are uniformly distributed along the circumferential direction. Each swirl vane 22 is provided with a vane hole 25 at the corresponding projection position on the swirl plate 21, and the vane hole 25 and the swirl vane 22 have the same structure and the same size. The swirl plate 21 is provided with a plurality of swirl flow holes 23, and the plurality of swirl flow holes 23 are uniformly distributed along the circumferential direction of the swirl plate 21. The center of the rotational flow plate 21 is provided with a central flow hole 24. The whirl plate 21 is equipped with whirl plate flange structure 26 along the outer lane edge, and whirl plate flange structure 26 can improve whirl plate 21's structural strength. The swirl vanes 22 and the swirl flow holes 23 can change the direction of the mixed gas flow entering the second cylinder 2, and the gas back pressure loss is gradually reduced as much as possible in the process of changing the direction. The mixed gas after passing through the swirl plate 21 forms a mixed gas vortex, further enhances the mixing effect, and then enters the SCR carrier 8 for reaction.

As shown in fig. 4, the mixed gas enters the upper part of the clam shell 3 after being divided into multiple paths through the sieve plates 16 at the lower part of the clam shell 3, most of the mixed gas is guided to the left area at the upper part of the clam shell 3 along with the sieve plates 16 and then enters the left area of the cyclone plate 21, and a small part of the mixed gas enters the right area at the upper part of the clam shell 3 and then enters the right area of the cyclone plate 21. This results in an uneven distribution of the air flow on both sides of the swirl plate 21, and even with the swirling effect, the air mixture reaching the SCR carrier 8 cannot be mixed uniformly. In order to make the airflow reaching the two sides of the rotational flow plate 21 uniformly distributed, a guide orifice plate 27 is fixedly arranged at the middle part in the clam shell 3, and the side surface of the guide orifice plate 27 is inserted into the insertion hole on the side wall of the clam shell 3 and welded. As shown in fig. 9, a plurality of pilot flow holes 28 are uniformly provided in the pilot orifice plate 27. The guide orifice plate 27 is in a circular arc plate structure, and the circular arc convex surface of the guide orifice plate 27 faces the outlet end of the airflow guide channel formed by the guide plate 15 and the inner side wall of the lower part of the clam shell 3.

The utility model discloses a theory of operation is: the utility model discloses set up DOC carrier 6 and DPF carrier 7 in the below of SCR carrier 8, set up second barrel 2 of SCR carrier 8 can be in same horizontal plane with whole car girder, set up 1 first barrels that DOC carrier 6 and DPF carrier 7 and be located whole car girder below, the blast pipe is connected from whole car girder below and diesel engine U type aftertreatment device, can satisfy the booster export and set up the aftertreatment installation demand for the engine down, reduce installation space by a wide margin. The DPF carrier low reaches set up baffle 10, sets up exhaust sprue 11 on the baffle 10, and most engine exhaust passes through exhaust sprue 11, makes engine exhaust fully contact as far as possible with the urea efflux, and the heat of engine exhaust drives urea pyrolysis, hydrolysis. The baffle plate 10 is provided with a plurality of flow holes 12, the area of the flow holes 12 is smaller as the distance from the exhaust main flow channel 11 is larger, the exhaust flow speed at the flow holes 12 is larger, and therefore gas collision at the position, far away from the exhaust main flow channel 11, on the baffle plate 10 is reduced, and exhaust pressure loss is reduced. The urea jet direction of the urea nozzle and the arrangement direction of the clam shell 3 facing the end face of the first cylinder 1 form an included angle beta, the included angle beta can enable the urea solution sprayed by the urea nozzle to be opposite to the exhaust direction of an engine, and the urea solution sprayed by the urea nozzle can be prevented from being directly impacted on the inner wall face of the clam shell 3 by the exhaust of the engine flowing out of the baffle 10 as much as possible. The guide plate 15 arranged in the clam shell 3 can gradually change the exhaust flow direction, so that the urea solution is prevented from being directly sprayed on the guide plate 15 to form a liquid film, and the crystallization risk is reduced. The sieve plate 16 with the circular arc structure is arranged in the clam shell 3, and the sieve plate 16 can guide mixed gas into the second cylinder 2. The mixed gas enters the upper part of the clam shell 3 after being divided into multiple paths by the sieve plates 16 at the lower part of the clam shell 3, and then the main air flow is dispersed by the guide hole plate 27, so that the air flow entering the left side and the right side of the rotational flow plate 21 can be uniformly distributed. The mixed gas after passing through the swirl plate 21 forms a mixed gas vortex, further enhances the mixing effect, and then enters the SCR carrier 8 for reaction. And finally the gas is discharged from the tail pipe 19.

The above description is for the purpose of explanation and not limitation of the invention, which is defined in the claims, and any modifications may be made within the scope of the invention.

Claims

1. The utility model provides a diesel engine U type aftertreatment device, includes upper and lower parallel arrangement's second barrel (2) and first barrel (1), the clam shell (3) inlet end is connected to first barrel (1) end of giving vent to anger, clam shell (3) end of giving vent to anger is connected second barrel (2) inlet end, and the terminal surface middle part that first barrel (1) and second barrel (2) are connected in clam shell (3) is equipped with bottom plate (30), bottom plate (30) both ends respectively with first barrel (1) and second barrel (2) sealing connection, its characterized in that: the air inlet end of the first cylinder (1) is provided with a front end cover (4), the center of the front end cover (4) is provided with a catalytic converter air inlet (9), a DOC carrier (6), a DPF carrier (7) and a baffle (10) are sequentially arranged in the inner cavity of the first cylinder (1) along the exhaust flowing direction, and an exhaust main runner (11) is arranged on the baffle (10);

a nozzle mounting seat (14) is welded on the side face of the air inlet end of the clam shell (3), a urea nozzle is detachably connected to the nozzle mounting seat (14) through a connecting piece, the urea nozzle extends into the clam shell (3) and faces the position of the air outlet end of an air exhaust main flow passage (11) on the baffle plate (10); a guide plate (15) with an arc-shaped structure is arranged in the clam shell (3), a plurality of guide plate insertion holes (32) are formed in the baffle (10), one side of the guide plate (15) is welded in the guide plate insertion holes (32) of the baffle (10), the other side of the guide plate (15) is inserted into the insertion holes of the base plate (30) and welded, the guide plate (15) is located on one side of a urea jet flow path of the urea nozzle, and a urea jet flow boundary line of the urea nozzle is tangent to the guide plate (15); a plurality of sieve plates (16) with arc structures are arranged in the clam shell (3), the sieve plates (16) are located between the guide plate (15) and the inner side wall of the lower portion of the clam shell (3), a plurality of sieve plate insertion holes (31) are formed in the baffle (10), the sieve plate insertion holes (31) are distributed along the edge of the exhaust main flow channel (11), one side of each sieve plate (16) is inserted into the sieve plate insertion hole (31) of the baffle (10) and welded, the other side of each sieve plate (16) is inserted into the insertion hole of the bottom plate (30) and welded, and the sieve plates (16) are located on a urea jet flow path of the urea;

a plurality of SCR carriers (8) are sequentially arranged in the inner cavity of the second cylinder (2) along the exhaust flowing direction, the end face of the air outlet of the second cylinder (2) is welded with an exhaust tail pipe (19), one end of the exhaust tail pipe (19) is provided with an exhaust outlet (29), and the air inlet end of the other end of the exhaust tail pipe extends into the second cylinder (2); the exhaust outlet (29) is positioned outside the second cylinder body (2), the air inlet end of the exhaust tail pipe (19) is positioned at the downstream of the SCR carriers (8), and the surface of the air inlet end of the exhaust tail pipe (19) is provided with a plurality of exhaust sieve holes (20); the air inlet end of the second cylinder (2) is provided with a cyclone plate (21), the cyclone plate (21) is perpendicular to the airflow direction in the second cylinder (2), the cyclone plate (21) is provided with a plurality of cyclone blades (22) which are obliquely arranged, and the plurality of cyclone blades (22) are uniformly distributed along the circumferential direction;

a guide pore plate (27) is fixedly arranged in the middle of the inner part of the clam shell (3), the side surface of the guide pore plate (27) is inserted into an insertion hole in the side wall of the clam shell (3) and is welded, and a plurality of guide flow holes (28) are uniformly arranged on the guide pore plate (27); the guide pore plate (27) is of a circular arc plate body structure, and the circular arc convex surface of the guide pore plate (27) faces to the outlet end of an airflow guide channel formed by the guide plate (15) and the inner side wall of the lower part of the clam shell (3).

2. The diesel engine U-shaped aftertreatment device of claim 1, characterized in that: the front end cover (4) gradually increases in cross section size from one side provided with the catalyst inlet (9) to the other side.

3. The diesel engine U-shaped aftertreatment device of claim 1, characterized in that: the baffle (10) is provided with a plurality of flow holes (12), and the area of the flow holes (12) which are farther away from the exhaust main flow passage (11) in the plurality of flow holes (12) is smaller.

4. A diesel engine U-shaped aftertreatment device according to claim 3, characterized in that: the baffle (10) is provided with a circle of baffle flanging structure (13) along the outer edge.

5. The diesel engine U-shaped aftertreatment device of claim 1, characterized in that: the included angle between the center line of the urea jet of the urea nozzle and the connecting line of the center of the SCR carrier (8) and the center of the DPF carrier (7) is alpha, and the angle range of the alpha is 15-45 degrees.

6. The diesel engine U-shaped aftertreatment device of claim 5, characterized in that: the urea nozzle is obliquely arranged towards the position of the main exhaust channel (11) on the baffle (10), the included angle between the urea jet direction of the urea nozzle and the arrangement direction of the clam shell (3) facing the end surface of the first cylinder (1) is beta, and the angle range of the beta is 5-10 degrees.

7. The diesel engine U-shaped aftertreatment device of claim 1, characterized in that: be equipped with guide vane (17) that a plurality of slopes set up on sieve (16), every guide vane (17) is equipped with sieve hole (18) corresponding the projection position on sieve (16), and sieve hole (18) and guide vane (17) structure is the same size equals.

8. The diesel engine U-shaped aftertreatment device of claim 1, characterized in that: every the projection position that whirl blade (22) correspond on whirl board (21) is equipped with blade hole (25), and blade hole (25) and whirl blade (22) structure are the same size and equal, are equipped with a plurality of whirl through holes (23) on whirl board (21), and a plurality of whirl through holes (23) are along whirl board (21) circumferencial direction evenly distributed, and whirl board (21) central point puts and is equipped with central through hole (24).

9. The diesel engine U-shaped aftertreatment device of claim 8, characterized in that: the swirl plate (21) is provided with a swirl plate flanging structure (26) along the edge of the outer ring.