CN115770404A - Marine diesel engine tail gas denitration system and evaporation mixing device thereof - Google Patents
Marine diesel engine tail gas denitration system and evaporation mixing device thereof Download PDFInfo
- Publication number
- CN115770404A CN115770404A CN202211483726.6A CN202211483726A CN115770404A CN 115770404 A CN115770404 A CN 115770404A CN 202211483726 A CN202211483726 A CN 202211483726A CN 115770404 A CN115770404 A CN 115770404A
- Authority
- CN
- China
- Prior art keywords
- evaporation
- guide plates
- plate
- marine diesel
- mixing device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Exhaust Gas After Treatment (AREA)
Abstract
The invention provides an evaporation mixing device of a tail gas denitration system of a marine diesel engine, wherein the evaporation mixing device comprises a first layer of evaporation mixing component and a second layer of evaporation mixing component which are sequentially arranged; the first layer of evaporation mixing assembly comprises two first guide plates and two second guide plates, and the first guide plates and the second guide plates are alternately arranged and connected through a support plate; the second layer of evaporation mixing assembly comprises two first guide plates which are connected through a support plate. The evaporation mixing device is arranged in the waste gas pipeline at the front end of the inlet of the reactor through a connecting rib plate. The invention realizes low pressure loss, can change the gas flow direction, increases the turbulent flow of a flow field, promotes the evaporation and decomposition of the urea solution and the mixing with high-temperature gas, and improves the distribution uniformity of the reducing agent at the inlet of the reactor.
Description
Technical Field
The invention relates to the technical field of marine diesel engine tail gas purification, in particular to a marine diesel engine tail gas denitration system and a low-pressure-loss evaporation mixing device thereof.
Background
Selective Catalytic Reduction (SCR) is a flue gas denitration technology, and is a mainstream technology for denitration treatment of tail gas of marine diesel engines. The regulations are increasingly strict and the space limitation on the ship is added, so that higher requirements are put on the denitration efficiency of the SCR reactor, on one hand, the catalyst efficiency is required to be higher, on the other hand, the space occupation of an SCR system is required to be smaller, and the mixed tail gas of the reducing agent is more uniformly distributed on the cross section of the catalyst in the compact SCR reactor.
Urea of the ship-borne SCR system is injected into an exhaust gas pipeline and is evaporated and mixed in the pipeline, and high-speed gas flow in the pipeline is wrapped with urea liquid drops to enter the reactor, so that urea solution is flushed into the reactor by the high-speed gas flow without being completely mixed. Because the space is limited, the duct system cannot be extended infinitely, so it is highly desirable to configure a mixing device in the SCR system to increase the disturbance of the air flow in the duct and the residence time of the urea droplets in the duct, so that the urea droplets are completely vaporized and decomposed and mixed with the exhaust gas. However, the design of the device requires attention to the pressure loss it brings to avoid excessively increasing the operating back pressure of the system.
At present, no explanation or report of the similar technology of the invention is found, and similar data at home and abroad are not collected.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a marine diesel engine tail gas denitration system and a low-pressure-loss evaporation mixing device thereof.
According to one aspect of the invention, the evaporation mixing device of the tail gas denitration system of the marine diesel engine comprises a first layer of evaporation mixing component and a second layer of evaporation mixing component which are arranged in sequence; wherein:
the first layer of evaporation mixing assembly comprises two first guide plates and two second guide plates, and the first guide plates and the second guide plates are alternately arranged and connected through a support plate;
the second layer of evaporation mixing assembly comprises two first guide plates, and the two first guide plates are connected through a support plate.
Optionally, an included angle is formed between the opening directions of the first layer of evaporation mixing assembly and the second layer of evaporation mixing assembly.
Optionally, the included angle is 90 °.
Optionally, the first guide plate is integrally of an isosceles triangle structure with a vertex angle removed.
Optionally, the second baffle is of an isosceles trapezoid structure as a whole.
Optionally, the two first guide plates are arranged oppositely at an angle and connected through the support plate, the two second guide plates are arranged oppositely between the two first guide plates, and two side edges of the second guide plates are tightly attached to the plate surfaces of the first guide plates to form the first layer of evaporation mixing assembly;
two be the relative setting of angle between the first guide plate, and pass through the backup pad is connected, constitute the evaporation of second floor mixes the subassembly.
Optionally, an included angle between the trapezoidal bottom of the second baffle and the two waists is 60 °.
Optionally, the first guide plates and the second guide plates are alternately arranged to form a quadrangular pyramid-shaped first-layer evaporation mixing assembly.
Optionally, two first deflectors are arranged at an angle of 60 ° relative to each other.
Optionally, the supporting plate is of a sheet-like trapezoidal structure, and two waist sides of the trapezoidal structure are respectively connected to the surface of the first air deflector.
Optionally, trapezoidal grooves arranged at equal intervals are respectively arranged on the bottom edges of the first guide plate and the second guide plate.
Optionally, the trapezoidal grooves on the oppositely arranged flow deflectors are staggered.
Optionally, the apparatus further comprises: the first supporting rib plate and the second supporting rib plate; wherein:
the first support rib plates are respectively connected to the outer surface of the first guide plate, and the second support rib plates are respectively installed on the two second guide plates in a penetrating mode.
Optionally, the length of the second support rib plate is greater than the length of the first support rib plate.
Optionally, the first support rib plates and the second support rib plates are perpendicular to each other and are arranged in a staggered manner.
Optionally, the first support rib plate and/or the second support rib plate are/is of a thin-sheet-shaped elongated rectangular structure.
According to another aspect of the invention, the marine diesel engine tail gas denitration system adopts one or more evaporation mixing devices as described in any one of the above, and the evaporation mixing devices are sequentially installed in an exhaust gas pipeline at the front end of a reactor inlet of the marine diesel engine tail gas denitration system.
Optionally, the evaporation mixing device is connected between the exhaust gas pipelines through end faces of support rib plates arranged on the first guide plate and the second guide plate.
Due to the adoption of the technical scheme, compared with the prior art, the invention has the following beneficial effects:
according to the marine diesel engine tail gas denitration system and the evaporation mixing device thereof, provided by the invention, the high-speed airflow input in the pipeline is redistributed in the radial direction of the section of the mixing device through the guide plate structure, and the airflow is disturbed through the multilayer mixing assembly, so that the turbulence degree of the air speed is further improved, and the further mixing of the reducing agent and the waste gas is promoted.
According to the marine diesel engine tail gas denitration system and the evaporation mixing device thereof, the trapezoidal groove structure at the tail part effectively reduces the friction loss caused by the vortex flow caused by the direct impact of the airflow on the inner wall of the pipeline, the pressure loss caused by the vortex flow is smaller, and the reduction by more than 15% is realized compared with a device without a groove.
According to the marine diesel engine tail gas denitration system and the evaporation mixing device thereof, the opening directions of the two groups of evaporation mixing assemblies form a certain included angle, and the evaporation mixing assemblies are used for changing the flow direction, increasing the turbulence of a flow field, promoting the evaporation and decomposition of urea solution and the mixing of the urea solution and high-temperature gas, and improving the distribution uniformity of a reducing agent at the inlet of an SCR reactor.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a schematic view of the overall structure of an evaporation mixing device according to a preferred embodiment of the present invention; wherein, (a) is a first layer of evaporation mixing component, and (b) is a second layer of evaporation mixing component.
FIG. 2 is a front view of an evaporative mixing apparatus in accordance with a preferred embodiment of the present invention; wherein, (a) is a first layer of evaporation mixing component, and (b) is a second layer of evaporation mixing component.
Fig. 3 is a schematic view of a connection structure of a first baffle and a second baffle of a first layer evaporative mixing assembly in a preferred embodiment of the present invention.
FIG. 4 is a velocity vector diagram of an air stream flowing through a low pressure loss evaporative mixing apparatus of a marine denitrification system in accordance with a preferred embodiment of the present invention; wherein, (a) is without fluting, (b) has fluting.
Wherein, 1 is the first guide plate, 2 is the backup pad, 3 is the second guide plate, 4 is the second support gusset, 5 is the first support gusset.
Detailed Description
The following examples illustrate the invention in detail: the embodiment is implemented on the premise of the technical scheme of the invention, and a detailed implementation mode and a specific operation process are given. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention.
An embodiment of the invention provides an evaporation mixing device of a marine diesel engine tail gas denitration system, which is beneficial to uniformly mixing diesel engine tail gas and a reducing agent in an exhaust gas pipeline in a short distance, improves the uniformity of the reducing agent before reaching a catalyst, and can optimize the pressure loss to be minimum.
As shown in fig. 1 to 3, the evaporation mixing device of the marine diesel engine exhaust denitration system provided by this embodiment may include a first layer of evaporation mixing component and a second layer of evaporation mixing component that are sequentially disposed; wherein:
the first layer of evaporation mixing assembly comprises two first guide plates 1 and two second guide plates 3, wherein the first guide plates 1 and the second guide plates 3 are alternately arranged and connected through a support plate 2;
the second layer of evaporation mixing assembly comprises two first guide plates 1, and the two first guide plates 1 are connected through a support plate 2.
In a preferred embodiment, the opening directions of the first layer of evaporation mixing components and the second layer of evaporation mixing components form an included angle. Further, the angle is 90 °.
In a preferred embodiment, the first baffle 1 is an isosceles triangle with a vertex removed.
In a preferred embodiment, the second baffle 3 is entirely in an isosceles trapezoid structure.
In a preferred embodiment, two first guide plates 1 are arranged oppositely at an angle and connected through a support plate 2, two second guide plates 3 are arranged oppositely between the two first guide plates 1, and two side edges of the second guide plates 3 are tightly attached to the plate surfaces of the first guide plates 1 to form a first layer of evaporation mixing assembly;
two first guide plates 1 are arranged oppositely at an angle and connected through a support plate 2 to form a second layer of evaporation mixing assembly.
In a preferred embodiment, the angle between the trapezoidal bottom of the second baffle 3 and the two waists is 60 °.
In a preferred embodiment, the first guide plates 1 and the second guide plates 3 are alternately arranged to form a first layer of evaporative mixing assembly in the shape of a quadrangular pyramid.
In a preferred embodiment, two first baffles 1 are arranged opposite to each other at an angle of 60 °.
In a preferred embodiment, the supporting plate 2 is a thin sheet-like trapezoid structure, and two waist sides of the trapezoid structure are respectively welded on the plate surface of the first air deflector.
In a preferred embodiment, trapezoidal grooves are respectively arranged on the bottom edges of the first guide plate 1 and the second guide plate 3 at equal intervals.
In a preferred embodiment, the trapezoidal grooves on the oppositely arranged flow deflectors are staggered.
In a preferred embodiment, the apparatus further comprises: a first support rib plate 5 and a second support rib plate 4; wherein:
the first support rib plates 5 are respectively connected to the outer surface of the first guide plate 1, and the second support rib plates 4 are respectively installed on the two second guide plates 3 in a penetrating mode.
In a preferred embodiment, the length of the second support webs 4 is greater than the length of the first support webs 5.
In a preferred embodiment, the first support rib plate 5 and the second support rib plate 4 are perpendicular to each other and staggered.
In a preferred embodiment, the first support webs 5 and/or the second support webs 4 are of laminar, elongated, rectangular configuration.
In some embodiments of the invention:
the first layer of evaporation mixing assembly mainly comprises two first guide plates with the same structure and two second guide plates with the same structure. Wherein, the first guide plate is an isosceles triangle plate with an angle shape at the top cut off; the second guide plate is of an isosceles trapezoid structure, and the included angle between the bottom of the trapezoid and the two sides can be 60 degrees. The first guide plate and the second guide plate of the first layer of evaporation mixing assembly are connected at intervals to form a quadrangular pyramid. The first guide plates are connected through the support plate, and the included angle is 60 degrees.
The second layer of evaporation mixing component mainly comprises two first guide plates with the same structure. The first baffle structure and the connection mode are the same as those of the first layer evaporation mixing assembly, and the description is omitted here.
The support rib is a sheet-shaped trapezoidal structure, and two waists of the trapezoidal structure are respectively welded on the first guide plate.
The tail parts (on the bottom plate) of the first guide plate and the second guide plate are provided with staggered trapezoidal grooves.
The first guide plate and the second guide plate are also provided with a support rib plate. The first support rib plate is arranged on the outer surface of the first guide plate, and the second support rib plate is arranged on the second guide plate in a penetrating mode. And when viewed from the axial direction of the pipeline, the first supporting rib plates and the second supporting rib plates are staggered at 90 degrees.
According to an embodiment of the invention, one or more evaporation mixing devices in any one of the above embodiments are adopted, and the evaporation mixing devices are sequentially arranged in an exhaust gas pipeline at the front end of a reactor inlet of the marine diesel engine exhaust denitration system.
In a preferred embodiment, the evaporative mixing apparatus is connected between the exhaust gas ducts via the end faces of the support webs arranged on the first and second flow guide plates.
In some embodiments of the invention:
the first guide plate is connected to the exhaust gas pipeline through the first support rib plate.
The second guide plate is connected to the waste gas pipeline through a second support rib plate penetrating through the plate body.
The support rib plates are of thin strip-shaped rectangular structures, the end faces of the support rib plates are respectively welded between the guide plates and the waste gas pipeline, and all the guide plates are connected to the inner wall of the waste gas pipeline. Furthermore, the thicknesses of the guide plate, the support plate and the support rib plate only need to ensure the strength under the working condition, and the guide plate, the support plate and the support rib plate are not too thick.
As shown in fig. 2, the included angle between two opposite first guide plates in each group of evaporation mixing assembly of the evaporation mixing device is 60 °, and the included angle between two opposite second guide plates 3 is 60 °.
As shown in fig. 3, the included angle a between the two waists and the bottom side of the first baffle ranges from 60 ° to 70 °.
As shown in fig. 4, the axial plane velocity vector diagram of the gas flowing through the evaporation mixing device is shown, wherein, (a) is the evaporation mixing device without the trapezoidal groove, and (b) is the evaporation mixing device with the trapezoidal groove. As can be seen from the figure, the evaporation mixing device provided with the trapezoidal groove can greatly reduce the local vortex of the airflow and reduce the pressure loss of the airflow flowing through the mixing device.
According to the marine diesel engine tail gas denitration system and the evaporation mixing device thereof provided by the embodiment of the invention, the side length of the guide plate, the side length of the support plate, the length of the support rib plate and the distance between the evaporation mixing assemblies of the evaporation mixing device are determined according to the pipe diameter of the waste gas pipeline, so that the evaporation mixing device is ensured to be suitable for reactors with different specifications. The evaporation mixing device is arranged in a straight pipeline at a distance from the front end of the inlet end of a reactor (SCR reactor) of the marine diesel engine tail gas denitration system body, so that the mixing nonuniformity of a reducing agent and waste gas entering the reactor is improved.
Through the marine diesel engine tail gas denitration system and the evaporation mixing device thereof that above embodiment provided, can be with the high-speed air current of input in the pipeline at the radial redistribution of mixing arrangement cross-section, through multilayer mixed structure, cause the disturbance to the air current, further improve the degree of disorder that the gas velocity is at, promote the further mixing of reductant and waste gas. The dovetail groove structure at the tail part of the mixing device effectively reduces the friction loss caused by the vortex caused by the direct impact of the airflow on the inner wall of the pipeline, thereby reducing the pressure loss of the system.
According to the marine diesel engine tail gas denitration system and the evaporation mixing device thereof provided by the embodiment of the invention, the evaporation mixing device realizes low pressure loss, the tail part of the guide plate is provided with the sawtooth structure, and the whole mixing device is fixed in the waste gas pipeline through the supporting rib plate. The opening directions of the two groups of evaporation mixing assemblies form a certain included angle, the included angle is used for changing the flow direction, increasing the turbulence of a flow field, promoting the evaporation and the decomposition of urea solution and the mixing with high-temperature gas, improving the distribution uniformity of reducing agents at the inlet of the SCR reactor, and simultaneously reducing the pressure drop of the mixing device by about 17 percent by the saw-tooth structure at the tail part.
The above embodiments of the present invention are not exhaustive of the techniques known in the art.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.
Claims (10)
1. An evaporation mixing device of a tail gas denitration system of a marine diesel engine is characterized by comprising a first layer of evaporation mixing component and a second layer of evaporation mixing component which are sequentially arranged; wherein:
the first layer of evaporation mixing assembly comprises two first guide plates and two second guide plates, and the first guide plates and the second guide plates are alternately arranged and connected through a support plate;
the second layer of evaporation mixing assembly comprises two first guide plates, and the two first guide plates are connected through a support plate.
2. The evaporative mixing device for the marine diesel exhaust denitration system of claim 1, wherein the first guide plate is of an isosceles triangle structure with a vertex angle removed, and the second guide plate is of an isosceles trapezoid structure; and/or
The first layer of evaporation mixing assembly and the second layer of evaporation mixing assembly are arranged in a certain included angle in the opening direction.
3. The evaporative mixing device of the marine diesel engine tail gas denitration system of claim 1, wherein two first guide plates are arranged oppositely in an angle and connected through the support plate, two second guide plates are arranged oppositely between the two first guide plates, and two side edges of the second guide plates are tightly attached to the plate surfaces of the first guide plates to form the first layer of evaporative mixing assembly;
two be the relative setting of angle between the first guide plate, and pass through the backup pad is connected, constitute the evaporation of second floor mixes the subassembly.
4. The evaporative mixing device for the marine diesel exhaust denitration system according to claim 3, further comprising any one or more of:
-the angle between the trapezoidal bottom of the second baffle and the two waists is 60 °;
-said first baffles and said second baffles are arranged alternately to form a first layer of evaporative mixing modules in the shape of a quadrangular pyramid;
-two of said first baffles are arranged at an angle of 60 ° relative to each other;
the support plate is of a sheet-like trapezoidal structure, and two waist sides of the trapezoidal structure are respectively connected to the plate surface of the first guide plate.
5. The evaporative mixing device for the marine diesel engine exhaust denitration system according to claim 1, wherein trapezoidal grooves are formed on the bottom edges of the first guide plate and the second guide plate at equal intervals.
6. The evaporative mixing device for the marine diesel engine exhaust denitration system according to claim 5, wherein the trapezoidal grooves of the guide plates which are oppositely arranged are staggered.
7. The evaporative mixing device for a marine diesel exhaust denitration system according to any one of claims 1 to 6, further comprising: the first supporting rib plate and the second supporting rib plate; wherein:
the first support rib plates are respectively connected to the outer surface of the first guide plate, and the second support rib plates are respectively installed on the two second guide plates in a penetrating mode.
8. The evaporative mixing device for the marine diesel engine exhaust denitration system according to claim 7, further comprising any one or more of the following:
-the length of the second support web is greater than the length of the first support web;
the first supporting rib plates and the second supporting rib plates are perpendicular to each other and are arranged in a staggered mode;
-the first support webs and/or the second support webs are of a sheet-like, elongated, rectangular configuration.
9. A marine diesel engine tail gas denitration system, characterized in that one or more evaporation mixing devices of any one of claims 1-7 are adopted, and the evaporation mixing devices are sequentially installed in an exhaust gas pipeline at the front end of a reactor inlet of the marine diesel engine tail gas denitration system.
10. The marine diesel exhaust denitration system of claim 9, wherein the evaporation mixing device is connected between the exhaust gas pipes through end faces of support rib plates arranged on the first guide plate and the second guide plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211483726.6A CN115770404A (en) | 2022-11-24 | 2022-11-24 | Marine diesel engine tail gas denitration system and evaporation mixing device thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211483726.6A CN115770404A (en) | 2022-11-24 | 2022-11-24 | Marine diesel engine tail gas denitration system and evaporation mixing device thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115770404A true CN115770404A (en) | 2023-03-10 |
Family
ID=85390093
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211483726.6A Pending CN115770404A (en) | 2022-11-24 | 2022-11-24 | Marine diesel engine tail gas denitration system and evaporation mixing device thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115770404A (en) |
-
2022
- 2022-11-24 CN CN202211483726.6A patent/CN115770404A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9909421B2 (en) | Mixing system for an exhaust gases after-treatment arrangement | |
| US9322309B2 (en) | Compact exhaust gas treatment unit with mixing region, method for mixing an exhaust gas and vehicle | |
| EP2111916B1 (en) | Gas treatment apparatus, vehicle equipped with it and method for treatment of an exhaust gas | |
| WO2011110885A1 (en) | Mixing system for an exhaust gas after-treatment arrangement | |
| US10252225B2 (en) | Method, apparatus and mixing device for evenly mixing reactant to exhaust gas flow | |
| CN103223310A (en) | Gas mixing arrangement | |
| GB2556890A (en) | Method, apparatus and system for aftertreatment of exhaust gas comprising inline housing | |
| CN204877615U (en) | Exhaust treatment appts | |
| CN206987927U (en) | Exhaust aftertreatment mixing arrangement and its encapsulation | |
| CN109184863B (en) | SCR mixing system and SCR mixer thereof | |
| CN102242662A (en) | Static mixer of selective catalytic reduction (SCR) denitration system | |
| CN103089383B (en) | Guiding device and guiding method for diesel engine selective catalytic reduction (SCR) system for automobile | |
| CN102444453A (en) | Static mixer for exhaust system | |
| CN212054866U (en) | Tail gas aftertreatment system | |
| CN218871279U (en) | Marine diesel engine tail gas denitration system and evaporation mixing device thereof | |
| CN115770404A (en) | Marine diesel engine tail gas denitration system and evaporation mixing device thereof | |
| CN211819593U (en) | SCR exhaust mixing device | |
| CN202391524U (en) | Static mixer for exhaust systems | |
| JP2016142265A (en) | Flow unit, exhaust emission control system, and method for exhaust emission control system | |
| CN213790962U (en) | Mixing device | |
| KR101427950B1 (en) | Mixer of selective catalyst reduction device for exhaust system | |
| CN109958512A (en) | Exhaust-gas treatment system for engine | |
| CN210385494U (en) | Mixing device | |
| CN209237721U (en) | A kind of static mixer | |
| CN210033574U (en) | Integrated type tail gas post-treatment box |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |