CN112360600A - SCR injection control system for internal combustion engine test bench based on air inflow - Google Patents

SCR injection control system for internal combustion engine test bench based on air inflow Download PDF

Info

Publication number
CN112360600A
CN112360600A CN202011196510.2A CN202011196510A CN112360600A CN 112360600 A CN112360600 A CN 112360600A CN 202011196510 A CN202011196510 A CN 202011196510A CN 112360600 A CN112360600 A CN 112360600A
Authority
CN
China
Prior art keywords
scr
internal combustion
combustion engine
exhaust
nitrogen
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
Application number
CN202011196510.2A
Other languages
Chinese (zh)
Inventor
陈鹏
臧志成
朱磊
邵祥
潘希伟
陆立井
邹旭杰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kailong High Technology Co Ltd
Original Assignee
Kailong High Technology Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Kailong High Technology Co Ltd filed Critical Kailong High Technology Co Ltd
Priority to CN202011196510.2A priority Critical patent/CN112360600A/en
Publication of CN112360600A publication Critical patent/CN112360600A/en
Pending legal-status Critical Current

Links

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
    • F01N3/08—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]
    • F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
    • 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
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • 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
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • F01N11/002—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M15/00—Testing of engines
    • G01M15/04—Testing internal-combustion engines
    • G01M15/10—Testing internal-combustion engines by monitoring exhaust gases or combustion flame
    • G01M15/102—Testing internal-combustion engines by monitoring exhaust gases or combustion flame by monitoring exhaust gases
    • 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
    • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
    • F01N2560/02—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor
    • F01N2560/026—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor for measuring or detecting NOx
    • 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
    • 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
    • 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
    • Y02T10/40—Engine management systems

Abstract

The invention discloses an SCR injection control system for an internal combustion engine test bench based on air intake flow, which can quickly and accurately judge the exhaust flow of various internal combustion engine models under various operating conditions based on an exhaust flowmeter, thereby adjusting the injection amount of urea aqueous solution in real time and effectively reducing NOx in the exhaust emission of the internal combustion engine. The invention saves the test time while realizing the judgment of the exhaust flow of the internal combustion engine, thereby promoting the effective application of SCR in the field of the internal combustion engine test bench, obviously reducing the pollution of nitrogen oxides in the exhaust of the internal combustion engine test bench to the environment and having important significance for ensuring the health of residents.

Description

SCR injection control system for internal combustion engine test bench based on air inflow
Technical Field
The invention relates to the technical field of tail gas treatment of an internal combustion engine test bench, in particular to an SCR injection control system for an internal combustion engine test bench based on air intake flow.
Background
With the gradual increase of the domestic reserves of internal combustion engine related vehicles, engineering machinery and ships, the reserves of test benches for internal combustion engine (vehicle) tests are also rapidly increased. The internal combustion engine test bench is mainly used for internal combustion engine (vehicle) product development, internal combustion engine (vehicle) related part performance test and internal combustion engine (vehicle) delivery inspection, and is an important guarantee for guaranteeing the performance of internal combustion engines or vehicles (or ships, engineering machinery and the like) taking the internal combustion engines as power sources. A large number of test racks are distributed in large internal combustion engine plants, whole engine plants, ship engine plants and ship engine maintenance service points in China, and the test racks also bring obvious environmental pollution problems while improving the quality of related products. Aiming at the test bed of the internal combustion engine (vehicle), China has no targeted emission regulation, pollutants are controlled according to the GB16297-1996 integrated emission standard of atmospheric pollutants or the atmospheric regulations of each place, in practice, nitrogen oxides of most test beds of the internal combustion engine (vehicle) are not additionally treated for various reasons, and tail gas of most test beds of the internal combustion engine (vehicle) is in a direct-emission state. The emission of nitrogen oxides of an untreated internal combustion engine (vehicle) is generally more than 4 times of the GB16297-1996 integrated emission standard of atmospheric pollutants, and because test benches of the internal combustion engine (vehicle) are often distributed together, the exhaust pollutants such as nitrogen oxides, particulate matters and the like can be continuously discharged in actual use, and the continuously discharged nitrogen oxides can cause respiratory diseases such as asthma and the like and cause frequent acid rain, the emission reduction of the pollutants in the tail gas of the test benches of the internal combustion engine (vehicle) is of great significance for improving the health of residents.
The Selective Catalytic Reduction (SCR) can effectively reduce the emission of nitrogen oxides, the technology sprays urea aqueous solution into an exhaust pipe of an internal combustion engine, ammonia (NH3) is provided by utilizing the hydrolysis of the urea aqueous solution, the catalytic reduction reaction is carried out under the action of a catalytic reduction device catalyst, NOx is converted into harmless nitrogen (N2), the emission reduction efficiency of the nitrogen oxides is up to more than 90 percent, and the nitrogen oxides are applied to diesel vehicles in the fourth and fifth countries in large batches, so that the generation of the phenomenon of acid rain is reduced, and various respiratory diseases caused by overhigh concentration of the NOx are reduced.
When the SCR is used, the injection quantity control is needed according to the exhaust flow, the exhaust temperature, the initial nitrogen and oxygen emission value and the final nitrogen and oxygen emission value of the internal combustion engine, because one test bench of the internal combustion engine (vehicle) generally needs to correspond to a plurality of internal combustion engine (vehicle) models, the exhaust flow of various internal combustion engines (vehicles) is different, the transmission of the exhaust flow, the circulating oil consumption and the like of the internal combustion engine cannot be carried out through a CAN message, and the operation that the air inflow is obtained by additionally installing an air inlet flow sensor is extremely inconvenient (the time requirement of a test bench is strict), so that the real-time injection quantity of the urea aqueous solution cannot be determined. And the exhaust flow of the internal combustion engine (vehicle) is sent through the CAN protocol or an exhaust flowmeter is arranged on the original internal combustion engine (vehicle), so that more time is spent on specific operation, the working state of relevant post-processing equipment needs to be switched, and the effective service time of the test bench is influenced.
Disclosure of Invention
The object of the present invention is to solve the problems mentioned in the background section above by means of an SCR injection control system for an internal combustion engine test bench based on intake air flow.
In order to achieve the purpose, the invention adopts the following technical scheme:
an SCR injection control system for an internal combustion engine test bench based on air intake flow comprises an exhaust gas flowmeter, an SCR front nitrogen-oxygen sensor and an aftertreatment control unit; the exhaust flowmeter is used for acquiring the exhaust flow of the internal combustion engine and outputting the exhaust flow to the aftertreatment control unit; the SCR front nitrogen-oxygen sensor is used for detecting an initial value of nitrogen oxide and outputting the initial value to the post-processing control unit; the post-processing control unit is used for calculating the basic injection of the urea aqueous solution according to the exhaust flow of the internal combustion engine, the initial value of the nitrogen oxide and the target emission reduction value of the nitrogen oxide after SCRAmount of urea aqueous solution, wherein the urea aqueous solution basic injection amount VCO(NH2)2The calculation formula of (a) is as follows:
Figure BDA0002754175850000031
VCO(NH2)2-urea water solution base injection quantity, L/h; g is the exhaust flow detection value of the internal combustion engine, kg/h; cNOx-in-pre-SCR nitrogen oxygen detection, ppm; cNOx-target-post-SCR nitrogen oxygen target emission reduction value, ppm; mCO(NH2)2-urea molar mass, 60.06 g/mol; mAirAir molar mass, 28.89 g/mol; cCO(NH2)2-concentration of urea aqueous solution, 32.5%; rhoCO(NH2)2Urea density, 1.087X 103kg/m3。
Particularly, the SCR injection control system for the internal combustion engine test bench based on the air intake flow further comprises an SCR front exhaust temperature sensor and an SCR rear exhaust temperature sensor; the post-processing control unit is used for determining the average temperature of the SCR through the measurement values of the SCR front exhaust temperature sensor and the SCR rear exhaust temperature sensor, searching a nitrogen oxide emission reduction efficiency MAP table of the SCR catalyst corresponding to different SCR average temperatures, and then calculating the urea aqueous solution rated injection quantity by combining the calculated urea aqueous solution basic injection quantity to finish real-time judgment of the urea aqueous solution rated injection quantity.
In particular, the SCR injection control system for an internal combustion engine test bench based on intake air flow rate further comprises a post-SCR nitrogen-oxygen sensor; and the post-processing control unit is used for comparing the measured value of the SCR rear nitrogen-oxygen sensor, namely the SCR rear nitrogen-oxygen value with the SCR rear nitrogen-oxygen target emission value, and calculating the urea aqueous solution correction injection quantity required by meeting the SCR rear nitrogen-oxygen target emission value by combining the exhaust flow of the internal combustion engine obtained by the exhaust flowmeter, so as to realize the regulation control of the urea aqueous solution injection quantity.
In particular, the exhaust gas flowmeter is installed at a position from the rear of an exhaust turbine of a turbocharger of an internal combustion engine to the front of a final exhaust outlet, and the front end of the exhaust gas flowmeter is required to reserve an equal-diameter exhaust pipe with a set length when the exhaust gas flowmeter is installed.
In particular, the SCR injection control system for an internal combustion engine test bench based on intake air flow rate further comprises an SCR differential pressure sensor; the SCR differential pressure sensor is used for detecting the particulate matter blocking degree of the SCR catalytic converter and reminding a user of timely cleaning the particulate matter when the SCR catalytic converter is blocked.
In particular, the SCR injection control system for the test bench of the internal combustion engine based on the air inflow further comprises an alarm module; the alarm module is used for giving an alarm when the SCR catalyst is blocked, and reminding a user of timely cleaning particles.
In particular, the alarm module comprises an audible and visual alarm lamp.
The SCR injection control system for the internal combustion engine test bench based on the air inflow is based on the exhaust flowmeter, and can quickly and accurately judge the exhaust flow of various internal combustion engine (vehicle) models under various operating conditions, so that the injection amount of the urea aqueous solution is adjusted in real time, and the NOx in the exhaust emission of the internal combustion engine is effectively reduced. The invention saves the test time while realizing the judgment of the exhaust flow of the internal combustion engine (vehicle), thereby promoting the effective application of SCR in the field of the internal combustion engine (vehicle) test bench, obviously reducing the pollution of nitrogen oxides in the exhaust of the internal combustion engine (vehicle) test bench to the environment, and having important significance for ensuring the health of residents.
Drawings
FIG. 1 is a schematic structural diagram of an SCR injection control system for an internal combustion engine test bench based on intake air flow according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an operation of an SCR injection control system for an internal combustion engine test bench based on intake air flow according to an embodiment of the present invention.
Detailed Description
The invention is further illustrated by the following figures and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It is also to be noted that, for the convenience of description, only a part of the contents, not all of the contents, which are related to the present invention, are shown in the drawings, and unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
The SCR injection control system for the internal combustion engine test bench based on the air inflow comprises an exhaust gas flowmeter, an SCR front nitrogen and oxygen sensor and an aftertreatment control unit; the exhaust flowmeter is used for acquiring the exhaust flow of the internal combustion engine and outputting the exhaust flow to the aftertreatment control unit; the SCR front nitrogen-oxygen sensor is used for detecting an initial value of nitrogen oxide and outputting the initial value to the post-processing control unit; the post-processing control unit is used for calculating the basic injection quantity of the urea aqueous solution according to the exhaust flow of the internal combustion engine, the initial value of the nitrogen oxide and the target emission reduction value of the nitrogen oxide after SCR; the urea aqueous solution basic injection quantity VCO(NH2)2The calculation formula of (a) is as follows:
Figure BDA0002754175850000051
VCO(NH2)2-urea water solution base injection quantity, L/h; g is the exhaust flow detection value of the internal combustion engine, kg/h; cNOx-in-pre-SCR nitrogen oxygen detection, ppm; cNOx-target-post-SCR nitrogen oxygen target emission reduction value, ppm; mCO(NH2)2-urea molar mass, 60.06 g/mol; mAirAir molar mass, 28.89 g/mol; cCO(NH2)2-concentration of urea aqueous solution, 32.5%; rhoCO(NH2)2Urea density, 1.087X 103kg/m3。
Specifically, in the embodiment, the SCR injection control system for an internal combustion engine test bench based on intake air flow further includes an SCR front exhaust temperature sensor and an SCR rear exhaust temperature sensor; the post-processing control unit is used for determining the average temperature of the SCR through the measurement values of the SCR front exhaust temperature sensor and the SCR rear exhaust temperature sensor, searching a nitrogen oxide emission reduction efficiency MAP table of the SCR catalyst corresponding to different SCR average temperatures, and then calculating the urea aqueous solution rated injection quantity by combining the calculated urea aqueous solution basic injection quantity to finish real-time judgment of the urea aqueous solution rated injection quantity.
Specifically, in the embodiment, the SCR injection control system for an internal combustion engine test bench based on intake air flow further includes a post-SCR nox sensor; and the post-processing control unit is used for comparing the measured value of the SCR rear nitrogen-oxygen sensor, namely the SCR rear nitrogen-oxygen value with the SCR rear nitrogen-oxygen target emission value, and calculating the urea aqueous solution correction injection quantity required by meeting the SCR rear nitrogen-oxygen target emission value by combining the exhaust flow of the internal combustion engine obtained by the exhaust flowmeter, so as to realize the regulation control of the urea aqueous solution injection quantity.
Specifically, in the present embodiment, the exhaust gas flowmeter is installed at a position after an exhaust turbine of a turbocharger of an internal combustion engine to before a final exhaust outlet, and the front end of the exhaust gas flowmeter is required to reserve an equal-diameter exhaust pipe with a set length when the exhaust gas flowmeter is installed.
Specifically, in the embodiment, the SCR injection control system for an internal combustion engine test bench based on intake air flow rate further includes an SCR differential pressure sensor; the SCR differential pressure sensor is used for detecting the particulate matter blocking degree of the SCR catalytic converter and reminding a user of timely cleaning the particulate matter when the SCR catalytic converter is blocked, so that the test precision of the test bench of the internal combustion engine (vehicle) is prevented from being reduced due to the increase of the backpressure of the SCR catalytic converter.
Specifically, in the embodiment, the SCR injection control system for an internal combustion engine test bench based on intake air flow further includes an alarm module; the alarm module is used for giving an alarm when the SCR catalyst is blocked, and reminding a user of timely cleaning particles. In this embodiment, the alarm module includes an audible and visual alarm lamp.
In practical application, as shown in fig. 1 and 2, in the figure, 1 indicates an internal combustion engine, 2 indicates a turbocharger, 3 indicates an exhaust pipe of the internal combustion engine, 4 indicates an exhaust flowmeter, 5 indicates a pre-SCR nox sensor, 6 indicates a pre-SCR exhaust temperature sensor, 7 indicates an SCR catalyst, 8 indicates an SCR differential pressure sensor, 9 indicates a post-SCR exhaust temperature sensor, 10 indicates a post-SCR nox sensor, 11 indicates a post-treatment control unit, 12 indicates an audible and visual alarm lamp, 13 indicates a urea solution storage tank, 14 indicates a compressed air unit, 15 indicates an injection supply unit, 16 indicates a urea nozzle, 17 indicates a urea mixer, and related lines and urea aqueous solution, compressed air delivery lines, and the like are not shown in the figure. Each functional module in fig. 2 is a functional module in the post-processing control unit.
The SCR injection control system based on the exhaust flowmeter flow judgment in the embodiment can judge the exhaust flow of the internal combustion engine by means of the exhaust flowmeter under the condition that the internal combustion engine is not required to be calibrated, and can determine the working state of the internal combustion engine by combining the exhaust temperature sensor. In addition, detecting initial emission of NOx in tail gas of the internal combustion engine through a nitrogen-oxygen sensor arranged at the front end of the SCR, and calculating the basic injection quantity of the urea solution according to a urea solution injection quantity calculation formula by combining a target emission NOx set value; then, determining the actual exhaust temperature of the SCR by combining with the front and rear exhaust temperature sensors of the SCR, determining the conversion efficiency of the nitrogen oxide during actual exhaust temperature by searching the conversion efficiency MAP of the SCR to the nitrogen oxide during different SCR exhaust temperatures, and calculating the rated injection quantity of the urea solution; and then detecting final NOx emission by combining a nitrogen-oxygen sensor arranged at the rear end of the SCR, and if the final emission exceeds a target emission NOx set value, additionally spraying a proper amount of urea aqueous solution by combining the working condition of the internal combustion engine so as to realize dynamic correction and adjustment of the SCR injection system.
When the internal combustion engine normally runs, exhaust gas discharged by the internal combustion engine 1 flows through the turbocharger 2 and enters the internal combustion engine exhaust pipeline 3, and at the moment, the exhaust flow of the internal combustion engine is measured in real time through the exhaust flowmeter 4. As shown in fig. 2, based on the working principle diagram of the SCR injection control system for the test bench of the internal combustion engine (vehicle) of exhaust flow and aftertreatment performance, the aftertreatment control unit 11 determines the basic urea injection amount through the urea injection amount calculation formula by using the detection value of the exhaust flowmeter 4, the detection value of the SCR front nitrogen-oxygen sensor 5 on the exhaust pipeline and the target emission nitrogen-oxygen value; searching a nitrogen oxide emission reduction efficiency MAP table of the SCR catalyst 7 corresponding to different SCR average temperatures through the SCR front exhaust temperature sensor 6 and the SCR rear exhaust temperature sensor 9, determining the nitrogen oxide conversion efficiency of the SCR catalyst 7, and calculating the rated injection quantity of the urea solution by dividing the basic urea injection quantity by the SCR nitrogen oxide conversion efficiency; and comparing the measured value of the SCR rear nitrogen-oxygen sensor 10 with a target emission value, if the measured value is higher than the target emission value, determining the corrected injection quantity of the urea aqueous solution by combining the obtained exhaust flow of the internal combustion engine determined by the exhaust flow meter 4, and adding the corrected injection quantity and the rated injection quantity to obtain the final total injection quantity of the urea aqueous solution. When urea solution is injected, the urea solution is pressurized from the urea solution storage tank 13 by the injection supply unit 15 controlled by the aftertreatment control unit 11, and is mixed with the compressed air delivered by the compressed air unit 14 in a gas-liquid manner in a mixing cavity of the injection supply unit 15, and the mixed urea is sprayed out from the urea nozzle 16, is uniformly mixed with the exhaust gas of the internal combustion engine under the action of the urea mixer 17, and finally enters the SCR catalyst 7 for catalytic reaction. This device has still been equipped with SCR pressure differential sensor 8 and is used for the exhaust pressure differential at control SCR catalyst converter 7 both ends to when pressure differential is too big, send audible and visual warning through audible and visual alarm lamp 12, remind the user in time to clear up SCR catalyst converter 7, in order to avoid long-time operation back, the SCR catalyst converter is blockked up by particulate matter or sulphate class material, causes internal-combustion engine (car) test bench exhaust backpressure too big, influences the test accuracy of test bench.
The technical scheme provided by the invention is based on the exhaust flowmeter, and the exhaust flow of various internal combustion engine (vehicle) models under various operating conditions is quickly and accurately judged, so that the urea aqueous solution injection amount is adjusted in real time, and the NOx in the exhaust emission of the internal combustion engine is effectively reduced. The invention saves the test time while realizing the judgment of the exhaust flow of the internal combustion engine (vehicle), thereby promoting the effective application of SCR in the field of the internal combustion engine (vehicle) test bench, obviously reducing the pollution of nitrogen oxides in the exhaust of the internal combustion engine (vehicle) test bench to the environment, and having important significance for ensuring the health of residents. The invention realizes the rapid and effective emission reduction of the nitrogen oxides in the tail gas of the test bench of various internal combustion engines (vehicles) based on the exhaust flow and the post-treatment performance, thereby reducing the damage of the nitrogen oxides to the environment.
It will be understood by those skilled in the art that all or part of the above embodiments may be implemented by the computer program to instruct the relevant hardware, and the program may be stored in a computer readable storage medium, and when executed, may include the procedures of the embodiments of the methods as described above. The storage medium may be a magnetic disk, an optical disk, a read-only memory or a random access memory.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims (7)

1. An SCR injection control system for an internal combustion engine test bench based on air intake flow is characterized by comprising an exhaust gas flowmeter, an SCR front nitrogen-oxygen sensor and an aftertreatment control unit; the exhaust flowmeter is used for acquiring the exhaust flow of the internal combustion engine and outputting the exhaust flow to the aftertreatment control unit; the SCR front nitrogen-oxygen sensor is used for detecting an initial value of nitrogen oxide and outputting the initial value to the post-processing control unit; the post-processing control unit is used for calculating a urea aqueous solution basic injection quantity according to the internal combustion engine exhaust flow, the nitrogen oxide initial value and the SCR post-nitrogen oxide target emission reduction value, wherein the urea aqueous solution basic injection quantity VCO(NH2)2The calculation formula of (a) is as follows:
Figure FDA0002754175840000011
VCO(NH2)2-urea water solution base injection quantity, L/h; g is the exhaust flow detection value of the internal combustion engine, kg/h; cNOx-in-pre-SCR nitrogen oxygen detection, ppm; cNOx-target-post-SCR nitrogen oxygen target emission reduction value, ppm; mCO(NH2)2-urea molar mass, 60.06 g/mol; mAirAir molar mass, 28.89 g/mol; cCO(NH2)2-concentration of urea aqueous solution, 32.5%; rhoCO(NH2)2Urea density, 1.087X 103kg/m3。
2. The SCR injection control system for an intake air flow-based internal combustion engine test bench of claim 1, further comprising an SCR front exhaust temperature sensor and an SCR rear exhaust temperature sensor; the post-processing control unit is used for determining the average temperature of the SCR through the measurement values of the SCR front exhaust temperature sensor and the SCR rear exhaust temperature sensor, searching a nitrogen oxide emission reduction efficiency MAP table of the SCR catalyst corresponding to different SCR average temperatures, and then calculating the urea aqueous solution rated injection quantity by combining the calculated urea aqueous solution basic injection quantity to finish real-time judgment of the urea aqueous solution rated injection quantity.
3. The SCR injection control system for an intake air flow-based internal combustion engine test bench of claim 2, further comprising a post-SCR nitrogen-oxygen sensor; and the post-processing control unit is used for comparing the measured value of the SCR rear nitrogen-oxygen sensor, namely the SCR rear nitrogen-oxygen value with the SCR rear nitrogen-oxygen target emission value, and calculating the urea aqueous solution correction injection quantity required by meeting the SCR rear nitrogen-oxygen target emission value by combining the exhaust flow of the internal combustion engine obtained by the exhaust flowmeter, so as to realize the regulation control of the urea aqueous solution injection quantity.
4. The SCR injection control system for the test bench of the internal combustion engine based on the air intake flow as recited in claim 3, wherein the exhaust gas flowmeter is installed at a position from the rear of the exhaust turbine of the turbocharger of the internal combustion engine to the front of the final exhaust outlet, and the front end of the exhaust gas flowmeter is required to reserve an equal-diameter exhaust pipeline with a set length when being installed.
5. The SCR injection control system for an intake air flow-based internal combustion engine test stand according to any one of claims 2 to 4, further comprising an SCR differential pressure sensor; the SCR differential pressure sensor is used for detecting the particulate matter blocking degree of the SCR catalytic converter and reminding a user of timely cleaning the particulate matter when the SCR catalytic converter is blocked.
6. The SCR injection control system for an intake air flow-based internal combustion engine test bench of claim 5, further comprising an alarm module; the alarm module is used for giving an alarm when the SCR catalyst is blocked, and reminding a user of timely cleaning particles.
7. The intake air flow-based SCR injection control system for an internal combustion engine test stand according to claim 6, wherein said alarm module comprises an audible and visual alarm lamp.
CN202011196510.2A 2020-10-30 2020-10-30 SCR injection control system for internal combustion engine test bench based on air inflow Pending CN112360600A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011196510.2A CN112360600A (en) 2020-10-30 2020-10-30 SCR injection control system for internal combustion engine test bench based on air inflow

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011196510.2A CN112360600A (en) 2020-10-30 2020-10-30 SCR injection control system for internal combustion engine test bench based on air inflow

Publications (1)

Publication Number Publication Date
CN112360600A true CN112360600A (en) 2021-02-12

Family

ID=74512415

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011196510.2A Pending CN112360600A (en) 2020-10-30 2020-10-30 SCR injection control system for internal combustion engine test bench based on air inflow

Country Status (1)

Country Link
CN (1) CN112360600A (en)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101674876A (en) * 2007-02-27 2010-03-17 巴斯福催化剂公司 Scr on low thermal mass filter substrates
CN102588055A (en) * 2012-02-24 2012-07-18 潍柴动力扬州柴油机有限责任公司 Independent type SCR (selective catalytic reduction) metered injection control method and system
CN102678239A (en) * 2012-06-04 2012-09-19 浙江大学 Independent SCR (semiconductor control rectifier) system control method and control device based on NOx (nitrogen oxide) sensor
CN102713180A (en) * 2009-12-18 2012-10-03 沃尔沃拉斯特瓦格纳公司 Method for controlling the reductant buffer level in an exhaust gas aftertreatment device
CN105649733A (en) * 2016-01-07 2016-06-08 浙江大学 SCR (selective catalytic reduction) system for small and medium-sized ships
CN106812577A (en) * 2017-03-30 2017-06-09 无锡威孚力达催化净化器有限责任公司 Scr system control device
CN109653845A (en) * 2018-12-27 2019-04-19 凯龙高科技股份有限公司 A kind of method for urea injection control meeting the control of in-use automotive NOx emission
CN110145387A (en) * 2018-02-14 2019-08-20 闵敏 Stationary gas generator tail gas processing method and its system
CN110314517A (en) * 2019-05-27 2019-10-11 上海亨远船舶设备有限公司 A kind of the urea jet control system and its control method of SCR denitration process peculiar to vessel

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101674876A (en) * 2007-02-27 2010-03-17 巴斯福催化剂公司 Scr on low thermal mass filter substrates
CN102713180A (en) * 2009-12-18 2012-10-03 沃尔沃拉斯特瓦格纳公司 Method for controlling the reductant buffer level in an exhaust gas aftertreatment device
CN102588055A (en) * 2012-02-24 2012-07-18 潍柴动力扬州柴油机有限责任公司 Independent type SCR (selective catalytic reduction) metered injection control method and system
CN102678239A (en) * 2012-06-04 2012-09-19 浙江大学 Independent SCR (semiconductor control rectifier) system control method and control device based on NOx (nitrogen oxide) sensor
CN105649733A (en) * 2016-01-07 2016-06-08 浙江大学 SCR (selective catalytic reduction) system for small and medium-sized ships
CN106812577A (en) * 2017-03-30 2017-06-09 无锡威孚力达催化净化器有限责任公司 Scr system control device
CN110145387A (en) * 2018-02-14 2019-08-20 闵敏 Stationary gas generator tail gas processing method and its system
CN109653845A (en) * 2018-12-27 2019-04-19 凯龙高科技股份有限公司 A kind of method for urea injection control meeting the control of in-use automotive NOx emission
CN110314517A (en) * 2019-05-27 2019-10-11 上海亨远船舶设备有限公司 A kind of the urea jet control system and its control method of SCR denitration process peculiar to vessel

Similar Documents

Publication Publication Date Title
CN106194365B (en) A kind of NOx emission monitoring method based on model
CN101988422B (en) Method and system for verifying the operation of an SCR catalyst
US8230677B2 (en) NOx control systems and methods for controlling NOx emissions
CN102817681B (en) Solid SCR (selective catalytic reduction) control system for diesel engine
CN102844533B (en) Engine and exhaust aftertreatment control
CN111794837B (en) Urea injection control system
CN105569789B (en) A kind of method and device for the SCR case blocking detecting engine
CN112879136B (en) Method and device for evaluating urea crystallization risk based on transient working condition
CN103046989B (en) Plug-and-play urea spraying control method and system
US20070042495A1 (en) Method of controlling injection of a reducing agent in an engine emissions control system
CN110645076B (en) NH based on model3Leak diagnosis method
CN112879137B (en) Method and device for evaluating urea crystallization risk based on steady-state working condition
AU2016201027B2 (en) Systems and methods for determining the quantity of a combustion product in a vehicle exhaust
CN105378242A (en) Exhaust gas cleaning system for internal combustion engine
CN107448266A (en) The automatic adding method of marine exhaust denitration urea and its device
CN107605577A (en) A kind of urea for vehicle hydrolysis SCR system and its control method
WO2021057444A1 (en) Method for quickly calibrating scr ammonia ratio factor of diesel engine
CN111226027B (en) Method for operating a diesel engine and diesel engine with NH3 concentration detection
JP5913619B2 (en) Diesel engine control device
CN112360600A (en) SCR injection control system for internal combustion engine test bench based on air inflow
CN115788636A (en) Diesel engine urine-fuel ratio calculation method based on NOx sensor numerical value
CN110905637A (en) Real-time detection reminding method for working efficiency of SCR system catalyst
CN202718734U (en) Environment friendly tail gas exhaust system
CN201818369U (en) Diesel engine for heavy-duty car
CN207377629U (en) Marine exhaust denitration urea automatic adding device

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
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20210212