CN111335985A - Exhaust route arrangement of diesel engine - Google Patents
Exhaust route arrangement of diesel engine Download PDFInfo
- Publication number
- CN111335985A CN111335985A CN202010250110.9A CN202010250110A CN111335985A CN 111335985 A CN111335985 A CN 111335985A CN 202010250110 A CN202010250110 A CN 202010250110A CN 111335985 A CN111335985 A CN 111335985A
- Authority
- CN
- China
- Prior art keywords
- stage
- diesel engine
- selective catalytic
- mixer
- exhaust
- 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
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims abstract description 60
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 55
- 239000004202 carbamide Substances 0.000 claims abstract description 55
- 239000007789 gas Substances 0.000 claims abstract description 49
- 238000010531 catalytic reduction reaction Methods 0.000 claims abstract description 45
- 230000003197 catalytic effect Effects 0.000 claims abstract description 16
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 14
- 239000000203 mixture Substances 0.000 claims abstract description 5
- 239000003054 catalyst Substances 0.000 claims description 11
- 230000003647 oxidation Effects 0.000 claims description 10
- 238000007254 oxidation reaction Methods 0.000 claims description 10
- 238000006722 reduction reaction Methods 0.000 claims description 6
- 238000011144 upstream manufacturing Methods 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 abstract description 7
- 239000007788 liquid Substances 0.000 abstract 2
- 239000000243 solution Substances 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001010 compromised effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/033—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices
- F01N3/035—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices with catalytic reactors, e.g. catalysed diesel particulate filters
-
- 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
- F01N3/105—General auxiliary catalysts, e.g. upstream or downstream of the main catalyst
- F01N3/106—Auxiliary oxidation catalysts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/02—EGR systems specially adapted for supercharged engines
- F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
- F02M26/05—High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/02—EGR systems specially adapted for supercharged engines
- F02M26/09—Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine
-
- 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
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
- F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
- F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
- F01N2610/146—Control thereof, e.g. control of injectors or injection valves
-
- 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
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Materials Engineering (AREA)
- Exhaust Gas After Treatment (AREA)
Abstract
The invention discloses an exhaust route arrangement of a diesel engine, which comprises a mixer, a turbocharger, a gas-liquid separator and a gas-liquid separator, wherein the mixer is directly connected to the outlet of a turbocharger turbine, and one part of exhaust gas of the diesel engine enters the mixer after being pressurized by the turbocharger; the first-stage urea injector is arranged at the mixer and used for injecting urea solution into the mixer; the first-stage selective catalytic reduction device is arranged at the downstream of the mixer, and the gas after the mixture gas is strengthened and mixed enters the first-stage selective catalytic reduction device to carry out the reaction of reducing the nitrogen oxides; a second stage Selective Catalytic Reduction (SCR) disposed downstream of the first stage selective catalytic reduction; the second stage urea injector is disposed at the second stage selective catalytic reducer to inject a urea solution into the second stage selective catalytic reducer. Therefore, the discharge route arrangement of the invention can work the first-stage urea injector at the low load of the diesel engine and work the second-stage urea injector at the medium and high load, thereby effectively reducing the generation of nitrogen oxides in the exhaust gas.
Description
Technical Field
The invention relates to the field of diesel engine emission, in particular to an emission route arrangement of a diesel engine.
Background
Under current technology conditions, the emissions of light-duty diesel engines typically use the following two technologies: (1) high pressure EGR + Low pressure EGR + aftertreatment (NSC + SCRF + SCR/ASC). (2) High pressure EGR + Low pressure EGR + aftertreatment (DOC + SCRF + SCR/ASC). These two existing solutions feature a combination of "high pressure EGR" and "low pressure EGR", and are not available alone and only include one SCR unit in the aftertreatment.
The two technical schemes have the following defects: 1) the combination of high-pressure EGR and low-pressure EGR simultaneously occupies a larger space of the whole vehicle cabin, and in order to ensure that the servo low-pressure EGR structure can be normally used, the matched parts also need to comprise parts such as a water-air intercooler, a degassing device, an exhaust valve and the like and corresponding gas and fluid pipelines, and the servo accessories bring adverse effects on the volume and the reliability of the diesel engine. 2) The technical routes of after-treatment (NSC + SCRF + SCR/ASC) and after-treatment (DOC + SCRF + SCR/ASC) are that the SCR is not arranged at the first stage behind the turbine of the supercharger, a long mixer is required before the SCR for fully mixing the urea aqueous solution and the tail gas, the size of an after-treatment device is large, the arrangement is difficult, and the reliability of the whole vehicle can be influenced by some compromised arrangements.
In view of the above two disadvantages, a technical route for a light diesel engine with high efficiency and small volume is needed to solve the problems encountered by light vehicles.
The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
Disclosure of Invention
The invention aims to provide an exhaust route arrangement of a diesel engine, which can carry out combined nitrogen oxide reduction reaction on exhaust gas of the diesel engine according to different working conditions of the diesel engine through a first-stage urea injector and a first-stage selective catalytic reduction device and a second-stage urea injector and a second-stage selective catalytic reduction device.
To achieve the above objects, the present invention provides an exhaust routing arrangement of a diesel engine including a mixer, a first stage urea injector, a first stage Selective Catalytic Reduction (SCR), a second stage Selective Catalytic Reduction (SCR), and a second stage urea injector. The mixer is directly connected with the outlet of the turbine of the supercharger, and part of the exhaust gas discharged by the diesel engine enters the mixer after being supercharged by the supercharger; the first-stage urea injector is arranged at the mixer and used for injecting urea solution into the mixer; the first-stage selective catalytic reduction device is arranged at the downstream of the mixer, and the gas after the mixture gas is strengthened and mixed enters the first-stage selective catalytic reduction device to carry out the reaction of reducing the nitrogen oxides; a second stage Selective Catalytic Reduction (SCR) disposed downstream of the first stage selective catalytic reduction; the second-stage urea injector is arranged at the second-stage selective catalytic reduction device and used for injecting urea solution into the second-stage selective catalytic reduction device; the first-stage urea injector works when the diesel engine is under low load, and the second-stage urea injector works when the diesel engine is under high load.
In a preferred embodiment, the exhaust routing arrangement of the diesel engine further comprises a Diesel Oxidation Catalyst (DOC) and a particulate trap (DPF). The diesel oxidation catalyst is arranged at the downstream of the first-stage selective catalytic reduction device; a particulate trap is disposed downstream of the diesel oxidation catalyst and upstream of the second stage urea injector.
In a preferred embodiment, the exhaust routing arrangement of the diesel engine further comprises a high pressure EGR assembly, and another part of the exhaust gas of the diesel engine after being treated by the high pressure EGR assembly will re-enter the intake system of the diesel engine.
In a preferred embodiment, the high pressure EGR assembly comprises an exhaust gas recirculation valve connected to the exhaust gas outlet of the diesel engine and an EGR cooler.
In a preferred embodiment, the exhaust routing of the diesel engine further comprises a temperature sensor and an onboard computer. The temperature sensor is used for sensing temperature data in the discharge route; the vehicle-mounted computer is in data connection with the temperature sensor, the first-stage urea ejector and the second-stage urea ejector and is used for controlling the first-stage urea ejector or the second-stage urea ejector to work through temperature data.
In a preferred embodiment, the exhaust emission temperature at low load of the diesel engine is in the range of 200-350 ℃ and at high load in the diesel engine is in the range of 350-550 ℃.
Compared with the prior art, the discharge route arrangement of the diesel engine has the following beneficial effects:
1) the first-stage SCR, DOC and DPF arranged on the discharge route can be compactly coupled into a whole, the front end of the mixer only needs a shorter mixer, the mixer realizes rapid mixing by utilizing the high temperature and strong airflow of the exhaust gas turbocharger, and the high first-stage SCR catalytic conversion efficiency can be kept when the diesel engine is under low load. The second stage of the SCR in the emission route can function at medium and high loads, and can catalytically convert NOx escaped from the first stage of SCR even under complex conditions, so that the tail gas meets the requirements of the national emission standard 6b or even higher. The advantages of small size of the after-treatment device and thorough removal of NOx in the exhaust gas are technically achieved.
2) Because the discharge route is designed by adopting a two-stage selective catalytic reduction device, the requirement can be met only by considering the use of a relatively simple high-pressure EGR assembly during the design of the diesel engine body, so the design difficulty is technically reduced, and meanwhile, a plurality of parts of servo low-pressure EGR are reduced, so that the diesel engine can be smaller in volume and fewer in parts, and the reliability of the diesel engine is greatly improved.
Drawings
FIG. 1 is a schematic front view of a discharge routing arrangement according to an embodiment of the present invention;
fig. 2 is a rear view schematic diagram of a discharge route arrangement according to an embodiment of the present invention.
Description of the main reference numerals:
1-a first stage urea injector, 2-a mixer, 3-a first stage selective catalytic reduction device, 4-a diesel oxidation type catalyst, 5-a particulate trap, 6-a second stage selective catalytic reduction device, 7-a second stage urea injector, and 8-a high pressure EGR assembly.
Detailed Description
The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.
Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.
As shown in fig. 1 to 2, an exhaust routing arrangement of a diesel engine according to a preferred embodiment of the present invention includes two devices, one of which includes a first-stage urea injector 1, a mixer 2, a first-stage selective catalytic reduction device 3(SCR), a diesel oxidation catalyst 4(DOC), a particulate trap 5(DPF), a second-stage selective catalytic reduction device 6, and a second-stage urea injector 7, which are connected at an exhaust gas emission outlet of diesel. The mixer 2 is directly connected with the outlet of the turbocharger turbine, and a part of the exhaust gas of the diesel engine enters the mixer 2 after being pressurized by the turbocharger. The first-stage urea injector 1 is provided at the mixer 2 to inject a urea solution into the mixer 2. The first-stage selective catalytic reduction device 3 is arranged at the downstream of the mixer 2, and the gas after the mixture gas is intensively mixed enters the first-stage selective catalytic reduction device 3 to carry out the nitrogen oxide reduction reaction. The diesel oxidation catalyst 4 is disposed downstream of the first stage selective catalytic reduction device 3. A particulate trap 5 is arranged downstream of the diesel oxidation catalyst 4. A second stage selective catalytic reduction 6(SCR) is disposed downstream of the diesel oxidation catalyst 4. The second-stage urea injector 7 is provided at the second-stage selective catalytic reduction device 6 to inject a urea solution into the second-stage selective catalytic reduction device 6.
Another device of the exhaust routing of the diesel engine of the present invention includes a high pressure EGR assembly 8 consisting of an EGR cooler and an exhaust gas circulation valve connected to an exhaust gas outlet of the diesel engine. Another part of the exhaust gas of the diesel engine is treated by the high-pressure EGR assembly 8 and then enters the intake system of the diesel engine again.
In some embodiments, the selective catalytic reducer is used for eliminating NOx (nitrogen oxides) in the tail gas of the diesel engine, and the working principle is briefly described as follows: the tail gas enters an exhaust mixer after coming out of the turbocharger, a first-stage urea injector is mounted on the mixer and used for spraying urea aqueous solution, urea is hydrolyzed and pyrolyzed at high temperature to generate NH3, NOX is reduced on the surface of a catalyst of the selective catalytic reduction device system by NH3 and is discharged out of N2, and redundant NH3 is oxidized into N2 to prevent leakage. The need for sufficient temperatures at higher conversion efficiencies for selective catalytic reducers is premised (data shown above about 240 ℃).
The exhaust routing of the diesel engine of the present invention comprises a two-stage Selective Catalytic Reduction (SCR) structure, the work division of which can be summarized as follows:
(1) when the diesel engine is used for emission certification test, the rotating speed is low and the load is low in the initial stage, and the exhaust gas temperature is low (in the range of about 200-350 ℃), so that the high-efficiency conversion work of the selective catalytic reducer is not facilitated. In this state, it is critical to use the exhaust gas temperature as close as possible to the outlet of the turbocharger turbine because the exhaust gas temperature decreases as the distance from the outlet increases. At this time, the first-stage selective catalytic reduction device 3 closely coupled to the supercharger of the present invention functions and is directly connected to the outlet of the turbine of the supercharger, and the exhaust gas temperature loss is small. During operation, the urea aqueous solution sprayed out of the urea injector 1 of the first-stage selective catalytic reduction device 3 is premixed by airflow at the outlet of the turbine of the supercharger, then the mixing effect is enhanced again in the mixer 2 behind the turbine of the supercharger, and the urea aqueous solution enters the first-stage selective catalytic reduction device 3 closely coupled with the supercharger to perform NOx reduction reaction. The distance between the mixed gas and the outlet of the supercharger is short, the heat loss is small, and the residual temperature still enables the selective catalytic reduction device 3 to exert the efficiency to purify NOX in the tail gas.
(2) When the diesel engine is at a medium rotation speed and a medium load, the exhaust gas temperature rises (in the range of about 350 ℃ to 550 ℃), and the gas flow becomes stronger with the rise of the rotation speed, which is not favorable for the operation of the first-stage selective catalytic reduction device 3 closely coupled to the supercharger, so that the first-stage selective catalytic reduction device 3 does not operate, i.e., the urea injector 1 of the first-stage selective catalytic reduction device 3 does not inject the urea aqueous solution. At this time, the higher temperature enables the second-stage selective catalytic reducer 6, which is located farther from the outlet of the turbocharger turbine, to achieve higher conversion efficiency, and therefore the second-stage selective catalytic reducer 6 comes into play. The urea injector 7 of the second-stage selective catalytic reduction device 6 injects an aqueous urea solution, and the mixture gas reacts in the second-stage selective catalytic reduction device 6 to purify NOX.
(3) When the diesel engine is at a high speed and a high load, which is similar to the case of the medium speed and the medium load, the nitrogen oxide reduction operation is performed using only the second-stage selective catalytic reducer 6.
(4) When the emission certification operation is completed in circulation and is used on an actual road, the working condition is relatively complex and is not stable and unchangeable in a certain working condition, namely, the diesel engine can be switched among low load, medium load and high load within a certain time and a cross area exists, which is often called as a variable working condition. Thus, the "two-stage selective catalytic reduction" version of the first and second stage selective catalytic reduction devices 3, 6 offers advantages under variable operating conditions. According to the level of the emission, the first-stage selective catalytic reduction device 3 which is closely coupled with the supercharger can be flexibly adjusted to work or the second-stage selective catalytic reduction device 6 which is far away from the outlet of the supercharger can be flexibly adjusted to work, and the first-stage selective catalytic reduction device 3 and the second-stage selective catalytic reduction device 6 can also be selected to work simultaneously until the NOx is purified to reach the standard.
In some embodiments, the diesel engine exhaust routing arrangement further comprises a temperature sensor and an onboard computer. The temperature sensor is used to sense temperature data in the discharge line, typically lower at low loads and higher at medium and high loads. The vehicle-mounted computer is in data connection with the temperature sensor, the first-stage urea injector 1 and the second-stage urea injector 7, and the vehicle-mounted computer is used for controlling the first-stage urea injector 1 to work or the second-stage urea injector 7 to work or work simultaneously through temperature data.
In some embodiments, the "high pressure EGR assembly 8" device functions to reduce NOX (nitrogen oxides) produced during combustion during the combustion phase in the diesel engine cylinder, and is controlled from the source to lay the foundation for efficient exhaust gas purification after treatment. The principle is as follows: the exhaust gas of the diesel engine and part of the exhaust gas are sent back to the air inlet pipe and mixed with fresh air, and then the mixed gas enters the cylinder of the diesel engine for combustion. The exhaust gas contains a large amount of polyatomic and incombustible gases such as CO2 and the like, and the exhaust gas has high specific heat capacity and absorbs a large amount of heat, so that the highest combustion temperature in the cylinder is reduced, the generation amount of NOX (nitrogen oxide) is reduced, and source emission reduction is realized. The "high pressure EGR" device can function at low, medium, and high loads as needed to reduce NOX emissions within a certain range (light engines can achieve EGR rates of about 35%) while achieving diesel engine performance.
From the above, the present invention is only directed to the characteristic that light vehicles have many emission low load regions as an embodiment, and the SCR distributed to different stages in the whole emission region plays a role of purifying NOX, so that the present invention can well meet the emission requirements of light vehicles, and obtain a more stable NOX emission purification effect and a wider emission margin. Thus, the route can be extended to a wider range of medium and heavy duty diesel engines to perform the same function.
In summary, the discharge route arrangement of the diesel engine of the present invention has the following advantages:
1) the first-stage SCR, DOC and DPF arranged on the discharge route can be compactly coupled into a whole, the front end of the mixer only needs a shorter mixer, the mixer realizes rapid mixing by utilizing the high temperature and strong airflow of the exhaust gas turbocharger, and the high first-stage SCR catalytic conversion efficiency can be kept when the diesel engine is under low load. The second stage of the SCR in the emission route can function at medium and high loads, and can catalytically convert NOx escaped from the first stage of SCR even under complex conditions, so that the tail gas meets the requirements of the national emission standard 6b or even higher. The advantages of small size of the after-treatment device and thorough removal of NOx in the exhaust gas are technically achieved.
2) Because the discharge route is designed by adopting a two-stage selective catalytic reduction device, the requirement can be met only by considering the use of a relatively simple high-pressure EGR assembly during the design of the diesel engine body, so the design difficulty is technically reduced, and meanwhile, a plurality of parts of servo low-pressure EGR are reduced, so that the diesel engine can be smaller in volume and fewer in parts, and the reliability of the diesel engine is greatly improved.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.
Claims (6)
1. An exhaust routing arrangement for a diesel engine, comprising:
the mixer is directly connected to the outlet of a turbocharger turbine, and a part of the exhaust gas of the diesel engine enters the mixer after being pressurized by the turbocharger;
a first stage urea injector disposed at the mixer to inject a urea solution into the mixer;
the first-stage selective catalytic reducer is arranged at the downstream of the mixer, and the gas after the mixture gas is subjected to enhanced mixing enters the first-stage selective catalytic reducer to perform nitrogen oxide reduction reaction;
a second stage selective catalytic reducer disposed downstream of the first stage selective catalytic reducer; and
a second stage urea injector disposed at the second stage selective catalytic reducer to inject a urea solution into the second stage selective catalytic reducer;
wherein the first stage urea injector operates at low loads in the diesel engine and the second stage urea injector operates at high loads in the diesel engine.
2. The exhaust routing arrangement of a diesel engine as set forth in claim 1, further comprising:
a diesel oxidation catalyst disposed downstream of the first stage selective catalytic reduction; and
a particulate trap disposed downstream of the diesel oxidation catalyst and upstream of the second stage urea injector.
3. The exhaust routing arrangement of a diesel engine as set forth in claim 1, further comprising a high pressure EGR assembly through which another portion of the exhaust gas of the diesel engine is treated to re-enter the intake system of the diesel engine.
4. The exhaust routing arrangement of a diesel engine as set forth in claim 3, wherein the high pressure EGR assembly comprises an EGR cooler and an exhaust gas recirculation valve connected to an exhaust outlet of the diesel engine.
5. The exhaust routing arrangement of a diesel engine as set forth in claim 1, further comprising:
a temperature sensor to sense temperature data within the discharge route; and
and the vehicle-mounted computer is in data connection with the temperature sensor, the first-stage urea injector and the second-stage urea injector, and is used for controlling the first-stage urea injector to work or the second-stage urea injector to work through the temperature data.
6. The exhaust routing arrangement of a diesel engine according to claim 1, characterized in that the exhaust emission temperature at low load of the diesel engine is in the range of 200-350 ℃, and the exhaust emission temperature at high load in the diesel engine is in the range of 350-550 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010250110.9A CN111335985A (en) | 2020-04-01 | 2020-04-01 | Exhaust route arrangement of diesel engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010250110.9A CN111335985A (en) | 2020-04-01 | 2020-04-01 | Exhaust route arrangement of diesel engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111335985A true CN111335985A (en) | 2020-06-26 |
Family
ID=71184611
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010250110.9A Pending CN111335985A (en) | 2020-04-01 | 2020-04-01 | Exhaust route arrangement of diesel engine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111335985A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11732629B1 (en) | 2022-05-10 | 2023-08-22 | Caterpillar Inc. | System, apparatus, and method for diesel exhaust fluid (DEF) dosing |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101321575A (en) * | 2005-11-30 | 2008-12-10 | 卡特彼勒公司 | Multi-stage system for selective catalytic reduction |
| CN204283567U (en) * | 2014-11-24 | 2015-04-22 | 张辉 | A kind of serial type diesel engine selective catalysis after-treatment device |
| CN109322730A (en) * | 2018-12-10 | 2019-02-12 | 广西玉柴机器股份有限公司 | Light-duty six diesel vehicle after-treatment system of state |
| CN211975116U (en) * | 2020-04-01 | 2020-11-20 | 广西玉柴机器股份有限公司 | Exhaust route arrangement of diesel engine |
-
2020
- 2020-04-01 CN CN202010250110.9A patent/CN111335985A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101321575A (en) * | 2005-11-30 | 2008-12-10 | 卡特彼勒公司 | Multi-stage system for selective catalytic reduction |
| CN204283567U (en) * | 2014-11-24 | 2015-04-22 | 张辉 | A kind of serial type diesel engine selective catalysis after-treatment device |
| CN109322730A (en) * | 2018-12-10 | 2019-02-12 | 广西玉柴机器股份有限公司 | Light-duty six diesel vehicle after-treatment system of state |
| CN211975116U (en) * | 2020-04-01 | 2020-11-20 | 广西玉柴机器股份有限公司 | Exhaust route arrangement of diesel engine |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11732629B1 (en) | 2022-05-10 | 2023-08-22 | Caterpillar Inc. | System, apparatus, and method for diesel exhaust fluid (DEF) dosing |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20060179823A1 (en) | Piston-type internal combustion engine | |
| KR102052755B1 (en) | Internal combustion engine | |
| WO2011090189A1 (en) | Exhaust purification device and exhaust purification method for diesel engine | |
| JP5630025B2 (en) | Diesel engine exhaust purification device and exhaust purification method | |
| KR101787333B1 (en) | Exhaust system and method for selective catalytic reduction | |
| GB2558562B (en) | Aftertreatment temperature control apparatus and method | |
| US20100263356A1 (en) | Arrangement for an exhaust line of an internal combustion engine | |
| CN112127975A (en) | Catalysis method and device for emission control of hybrid diesel engine | |
| CN111485978A (en) | System and method for exhaust gas aftertreatment | |
| US11708808B2 (en) | Systems and methods for treated exhaust gas recirculation in internal combustion engines | |
| CN111894766A (en) | Vehicle system with low-pressure EGR loop | |
| CN211975116U (en) | Exhaust route arrangement of diesel engine | |
| CN111335985A (en) | Exhaust route arrangement of diesel engine | |
| KR100999646B1 (en) | Exhaust gas recirculation system | |
| JP2008127997A (en) | Exhaust emission control device of internal combustion engine | |
| CN212337488U (en) | Aftertreatment system with dual-oxidation catalytic converter | |
| CN110998081B (en) | Exhaust gas recirculation system of engine | |
| CN113864033A (en) | Tail gas emission control system for light vehicle engine | |
| CN111502871A (en) | Aftertreatment system with dual-oxidation catalytic converter | |
| CN220015311U (en) | European seven post-processing system of diesel engine | |
| JP5471089B2 (en) | Reducing agent supply device for urea SCR catalyst | |
| CN207554222U (en) | A kind of egr system | |
| CN100432384C (en) | Piston-type internal combustion engine | |
| CN219754628U (en) | Integrated high-efficiency tail gas aftertreatment system for secondary vehicle | |
| CN113565619B (en) | Engine and air inlet and exhaust system thereof |
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 |