CN111828187A - Diesel nitrogen oxide storage and catalytic reaction control strategy - Google Patents
Diesel nitrogen oxide storage and catalytic reaction control strategy Download PDFInfo
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- CN111828187A CN111828187A CN202010759894.8A CN202010759894A CN111828187A CN 111828187 A CN111828187 A CN 111828187A CN 202010759894 A CN202010759894 A CN 202010759894A CN 111828187 A CN111828187 A CN 111828187A
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- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 title claims abstract description 121
- 238000006555 catalytic reaction Methods 0.000 title claims abstract description 10
- 238000011217 control strategy Methods 0.000 title claims abstract description 10
- 239000003054 catalyst Substances 0.000 claims abstract description 59
- 230000008929 regeneration Effects 0.000 claims abstract description 18
- 238000011069 regeneration method Methods 0.000 claims abstract description 18
- 238000006477 desulfuration reaction Methods 0.000 claims abstract description 16
- 230000023556 desulfurization Effects 0.000 claims abstract description 16
- 238000006243 chemical reaction Methods 0.000 claims abstract description 7
- 230000001680 brushing effect Effects 0.000 claims abstract description 3
- 239000000463 material Substances 0.000 claims abstract description 3
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 3
- 238000000034 method Methods 0.000 claims description 27
- 230000008569 process Effects 0.000 claims description 24
- 239000007789 gas Substances 0.000 claims description 23
- 238000001179 sorption measurement Methods 0.000 claims description 22
- 239000000446 fuel Substances 0.000 claims description 15
- 238000002347 injection Methods 0.000 claims description 14
- 239000007924 injection Substances 0.000 claims description 14
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 claims description 12
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 6
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 6
- 239000003638 chemical reducing agent Substances 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 4
- 238000002485 combustion reaction Methods 0.000 claims description 4
- 239000001301 oxygen Substances 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- 229910001018 Cast iron Inorganic materials 0.000 claims description 3
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- DOTMOQHOJINYBL-UHFFFAOYSA-N molecular nitrogen;molecular oxygen Chemical compound N#N.O=O DOTMOQHOJINYBL-UHFFFAOYSA-N 0.000 claims description 3
- 238000004321 preservation Methods 0.000 claims description 3
- 238000011946 reduction process Methods 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 239000003344 environmental pollutant Substances 0.000 description 5
- 231100000719 pollutant Toxicity 0.000 description 5
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 238000012827 research and development Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000032683 aging Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000002283 diesel fuel Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 201000009240 nasopharyngitis Diseases 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
- F02D41/0275—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a NOx trap or adsorbent
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D29/00—Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto
- F02D29/02—Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0002—Controlling intake air
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0002—Controlling intake air
- F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0047—Controlling exhaust gas recirculation [EGR]
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
- F02D41/0275—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a NOx trap or adsorbent
- F02D41/028—Desulfurisation of NOx traps or adsorbent
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
- F02D41/1452—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being a COx content or concentration
- F02D41/1453—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being a COx content or concentration the characteristics being a CO content or concentration
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/3005—Details not otherwise provided for
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/08—Throttle valves specially adapted therefor; Arrangements of such valves in conduits
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2430/00—Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
- F01N2430/06—Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics by varying fuel-air ratio, e.g. by enriching fuel-air mixture
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
- F01N2570/14—Nitrogen oxides
Abstract
The invention relates to the technical field of vehicle control, in particular to a diesel nitrogen oxide storage and catalytic reaction control strategy, which comprises the following steps: determining the contents of noble metal and adsorbing material of the nitrogen oxide catalyst, and determining a conversion efficiency curve; calibrating an engine original exhaust NOx model; calibrating the regeneration of the catalyst; carrying out desulfurization calibration on the catalyst; calibrating the drivability; temperature control calibration; and obtaining data according to the result of the double number, and inputting the data into a software brushing control unit. The invention can effectively reduce the nitrogen oxide discharged to the atmosphere by the diesel vehicle and reduce the nitrogen oxide in the air.
Description
Technical Field
The invention relates to the technical field of vehicle control, in particular to a diesel nitrogen oxide storage and catalytic reaction control strategy.
Background
With the increasing national management and control of automobile exhaust, how to reduce pollutants in automobile exhaust becomes a common topic in the automobile research and development industry.
In 7/1/2020, the national environmental protection agency will test the light vehicle emission pollutants according to the light vehicle emission standard of the sixth b stage in China, and the following table 1 lists the light diesel vehicle emission test standards of the fifth stage in China and the light diesel vehicle emission test standards of the sixth b stage in China in Table 2
TABLE 1 national five-stage light-duty diesel vehicle emission limits
TABLE 2 national sixth stage light-duty diesel vehicle emission limits
The emission pollutants of light diesel vehicles produced after 1/7/2020 must be less than the limits of Table 2, and the regulatory standard for nitrogen oxides (NOx) in the emission pollutants is reduced from 280mg/Km of Friday to 50 mg/Km. For the research and development of light diesel vehicles in six stages of the whole country, the reduction of pollutant NOx in exhaust gas is a key link in research and development work.
In response to the national call, the storage catalyst technology (NSC) for nitrogen oxides in exhaust gas has been developed in response to the national call in order to meet the standards for vehicle detection issued by the environmental protection agency.
For the reasons stated above, the present invention provides a diesel nox storage and catalytic reaction control strategy.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a diesel nitrogen oxide storage and catalytic reaction control strategy, which can effectively reduce nitrogen oxides discharged to the atmosphere by a diesel automobile and reduce nitrogen oxides in the air.
The invention discloses a diesel nitrogen oxide storage and catalytic reaction control strategy, which comprises the following steps:
s1: determining the contents of noble metal and adsorbing material of the nitrogen oxide catalyst, and determining a conversion efficiency curve;
s2: calibrating an engine original exhaust NOx model: judging whether the deviation between the original row model and the measured value exceeds 30 percent;
s3: and (3) regeneration calibration of the catalyst: by changing combustion parameters, the engine generates a large amount of reducing agent carbon monoxide, and whether the carbon monoxide in tail gas reaches 20000ppm or not when the catalyst is regenerated is judged;
s4: and (3) desulfurization calibration of a catalyst: judging whether the carbon monoxide in the exhaust gas reaches 20000ppm while the catalyst is regenerated in step S3 while the internal temperature of the catalyst is maintained at 600 to 700 ℃;
s5: and (3) driving performance calibration: judging whether the vehicle has obvious pause and frustration feeling when the catalyst is regenerated in the process of normally driving the vehicle;
s6: temperature control calibration: judging whether the temperature of the supercharger is over-temperature or not when the temperature of the catalyst is peak in the desulfurization process in the step S4;
s7: and obtaining data according to the result of the double number, and inputting the data into a software brushing control unit.
According to the O of the intake mixing point of the intake engine2Concentration is exponential with the concentration of NOx in the exhaust gas, y ═ exEstablishing a NOx emission model of a front-end exhaust system of the catalyst; running the engine on the engine mount, recording the oxygen concentration and NOx concentration for different engine speeds and engine torques, the equivalent equation is as follows:
taking the logarithm on both sides of the equation, then:
REF: EGR valve off mode; EGR: EGE valve open mode; AKT: a normal mode. O for opening and closing EGR valve of each working condition2The concentration and NOx concentration are measured, and the NOx concentration and O of alpha and closed EGR valve can be obtained2Concentration; o to mark mixing point2A concentration model that can obtain the NOx concentration in the exhaust gas according to the formula (1);
establishing a model between NOx adsorption efficiency and exhaust temperature and adsorption quantity according to the NOx emission model value and the measured value of a nitrogen-oxygen sensor at the outlet end of the catalyst; the adsorption process is mainly NOx and barium carbonate (BaCO) in the coating on the catalyst support3) The reaction is carried out according to the following equation:
2NO+O2→2NO2
4NO2+2BaCO3+O2→2Ba(NO3)2+2CO2
the calculation formula of the exhaust temperature, the adsorption amount and the adsorption efficiency is as follows:
in step S3, the catalyst regeneration process is to control the air intake amount, the intake pressure, the fuel injection amount of the piston exhaust stroke, the injection angle and the throttle value of the engine so that the ratio of the air intake amount to the fuel injection amount of the engine is smaller than 14.5 of the theoretical air-fuel ratio of diesel, control the value of λ to be about 0.92, generate a large amount of CO as a reductant, reduce NOx in the catalyst to N2 by utilizing the chemical property of CO reducibility, and keep the whole reduction process within 10S, wherein the calculation formula of λ is as follows:
in step S4, the catalyst desulfurization process: firstly, increasing the fuel injection quantity, reducing the opening of a throttle valve, and increasing the internal temperature of the catalyst to 600-700 ℃ for heat preservation; secondly, switching the engine to a regeneration mode for desulfurization, wherein the internal temperature of the catalyst can be continuously increased in the desulfurization process; when the catalyst internal temperature rises to 700 ℃, the engine switches from the regeneration mode to the catalyst warm-up mode.
In step S6, the temperature control method of the supercharger is as follows: firstly, introducing a part of exhaust gas into an air inlet system through an EGR valve in a circulating system to reduce the heat energy flowing through a supercharger; secondly, the cold end EGR valve is replaced by a hot end EGR valve, so that the exhaust temperature exceeding 600 ℃ can be borne; and thirdly, replacing the plastic air inlet connecting pipe with a cast iron air inlet connecting pipe.
The invention has the beneficial effects that:
(1) the invention can effectively reduce the nitrogen oxide discharged to the atmosphere by the diesel vehicle and reduce the nitrogen oxide in the air.
Drawings
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is a graphical illustration of oxygen concentration versus NOx concentration for various engine speeds and engine torques in accordance with the present invention;
FIG. 3 is a schematic diagram of the NOx adsorption process of the present invention;
FIG. 4 is a graph showing the relationship between the exhaust gas temperature and the adsorption amount and the adsorption efficiency in the present invention;
FIG. 5 is a graph showing the reduction of NOx to N by CO in the present invention2Schematic process diagram of (1).
Detailed Description
The invention is further illustrated below:
referring to figures 1-5 of the drawings,
the invention discloses a diesel nitrogen oxide storage and catalytic reaction control strategy, which comprises the following steps:
1) the method for controlling NOx adsorption comprises the following steps:
according to the O of the intake mixing point of the intake engine2Concentration is exponential with the concentration of NOx in the exhaust gas, y ═ exEstablishing a NOx emission model of a front-end exhaust system of the catalyst; in thatThe engine is operated on the engine mount, and the relationship of FIG. 2 is obtained by recording the oxygen concentration and NOx concentration under different conditions (engine speed and engine torque), with the equivalent equation being
Taking logarithm on both sides of equation as formula 2
REF: EGR valve off mode; EGR: EGE valve open mode; AKT: a normal mode. O for opening and closing EGR valve of each working condition2The concentration and NOx concentration are measured, and the NOx concentration and O of alpha and closed EGR valve can be obtained2And (4) concentration. O to mark mixing point2The concentration model can obtain the NOx concentration in the exhaust gas according to the formula (1).
Establishing a model between NOx adsorption efficiency and exhaust temperature and adsorption quantity according to the NOx emission model value and the measured value of a nitrogen-oxygen sensor at the outlet end of the catalyst; the adsorption process is mainly NOx and barium carbonate (BaCO) in the coating on the catalyst support3) The reaction is carried out, as shown in fig. 3, the NOx adsorption process, and the reaction equation is as follows:
2NO+O2→2NO2
4NO2+2BaCO3+O2→2Ba(NO3)2+2CO2
the relationship between the exhaust gas temperature and the adsorption amount and the adsorption efficiency is shown in FIG. 4, and the efficiency calculation formula is as follows:
2) and calibrating a catalyst regeneration technology. The efficiency of the catalyst in adsorbing NOx is inversely proportional to the amount of adsorption at the same exhaust temperature. Therefore, in order to maintain the NSC at 50% adsorption efficiency, the catalyst must be automatically regenerated according to the amount of adsorbed grams after the catalyst adsorbs a certain amount of NOxAnd (4) generating. The regeneration process is to control a series of parameters of air inflow, air inlet pressure, oil injection quantity of piston exhaust stroke, injection angle, throttle valve value and the like of the engine. Controlling the parameters to ensure that the ratio of the air inflow and the fuel injection quantity of the engine is smaller than the theoretical air-fuel ratio of 14.5 of diesel oil, controlling the value of lambda to be about 0.92, generating a large amount of reducing agent CO by the engine, and reducing NOx in a catalytic converter into N by utilizing the chemical property of CO with reducibility2The whole reduction process is kept within 10 s. The formula of lambda is as follows:
FIG. 5 is a graph of CO reduction of NOx to N2The process of (1).
3) And (5) desulfurization calibration of the catalyst. The catalyst can adsorb NOx and sulfide, and the internal temperature of the catalyst needs to be kept between 600 and 700 ℃ in the process of reducing sulfide. The reducing agent reacts with sulfide slowly at the temperature lower than 600 ℃, and the aging of the catalyst is increased and the service life is influenced if the temperature is higher than 700 ℃. The desulfurization process is complicated relative to the process of reducing NOx.
Firstly, increasing the fuel injection quantity, reducing the opening of a throttle valve, and increasing the internal temperature of the catalyst to 600-700 ℃ for heat preservation; secondly, switching the engine to a regeneration mode for desulfurization, wherein the internal temperature of the catalyst can be continuously increased in the desulfurization process; when the catalyst internal temperature rises to 700 ℃, the engine switches from the regeneration mode to the catalyst warm-up mode. FIG. 5 is a desulfurization process.
4) And calibrating the driving feeling of the whole vehicle from the normal mode to the regeneration mode of the engine. After the engine is switched to a catalyst regeneration mode, firstly, the air inflow and the air intake pressure can be changed, and are different from the common mode of the engine in terms of hearing, because the air inflow is reduced when the throttle valve is reduced, the combustion in the cylinder is not as violent as the common mode, the combustion noise is relatively clunk, and the sound is smaller than that in the common mode; and secondly, the fuel injection quantity is increased, the fuel quantity is a source of output torque of the engine, the torque fluctuation is directly caused by the change of the fuel quantity, and the vehicle can slightly shake.
Because the technology is applied to the whole vehicle, the catalyst can be regenerated once in more than ten minutes, the mode switching of the engine is frequent, and the sound change of the engine and the fluctuation of the torque can directly influence the driving feeling of the vehicle for the terminal client. This transient state, resulting from catalyst regeneration in engine mode switching, is the focus of this technology.
5) Temperature control, during catalyst regeneration, the intake air amount decreases and the fuel injection amount increases, resulting in a very high exhaust temperature.
The first effect is the supercharger, the temperature of the air inlet at the vortex end of the supercharger can reach 830 ℃ in a short time in the regeneration process, the limit temperature which can be borne by the supercharger is 820 ℃, and in order to reduce the risk of burning out of the supercharger, a part of exhaust gas is introduced into an air inlet system through an EGR valve in a circulating system by utilizing the exhaust gas, so that the heat energy flowing through the supercharger is reduced.
Secondly, high-temperature exhaust gas passes through the EGR valve through an exhaust gas circulation pipeline and then flows into an air inlet connecting pipe of the engine, the temperature of the exhaust gas at the EGR position can reach 600 ℃, and a common cold-end EGR valve can only bear the temperature of 400 ℃. To ensure that the project can be carried out smoothly, the cold-end EGR valve is replaced by a hot-end EGR valve, and the exhaust temperature exceeding 600 ℃ can be borne.
When the exhaust gas passes through the EGR valve, the exhaust gas reaches the air inlet connecting pipe and is mixed with the fresh air inlet amount, the highest temperature reaches 110 ℃, the temperature which can be borne by the plastic air inlet connecting pipe is 120 ℃, and in order to reduce the risk that the air inlet connecting pipe is burnt out, the plastic air inlet connecting pipe is replaced by a cast iron air inlet connecting pipe.
The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent modifications made by the present invention and the contents of the drawings or directly or indirectly applied to the related technical fields are included in the scope of the present invention.
Claims (5)
1. A diesel nitrogen oxide storage and catalytic reaction control strategy is characterized by comprising the following steps:
s1: determining the contents of noble metal and adsorbing material of the nitrogen oxide catalyst, and determining a conversion efficiency curve;
s2: calibrating an engine original exhaust NOx model: judging whether the deviation between the original row model and the measured value exceeds 30 percent;
s3: and (3) regeneration calibration of the catalyst: by changing combustion parameters, the engine generates a large amount of reducing agent carbon monoxide, and whether the carbon monoxide in tail gas reaches 20000ppm or not when the catalyst is regenerated is judged;
s4: and (3) desulfurization calibration of a catalyst: judging whether the carbon monoxide in the exhaust gas reaches 20000ppm while the catalyst is regenerated in step S3 while the internal temperature of the catalyst is maintained at 600 to 700 ℃;
s5: and (3) driving performance calibration: judging whether the vehicle has obvious pause and frustration feeling when the catalyst is regenerated in the process of normally driving the vehicle;
s6: temperature control calibration: judging whether the temperature of the supercharger is over-temperature or not when the temperature of the catalyst is peak in the desulfurization process in the step S4;
s7: and obtaining data according to the result of the double number, and inputting the data into a software brushing control unit.
2. The diesel nox storage and catalytic reaction control strategy of claim 1, wherein O is based on intake engine intake mixing point2Concentration is exponential with the concentration of NOx in the exhaust gas, y ═ exEstablishing a NOx emission model of a front-end exhaust system of the catalyst; running the engine on the engine mount, recording the oxygen concentration and NOx concentration for different engine speeds and engine torques, the equivalent equation is as follows:
taking the logarithm on both sides of the equation, then:
REF: EGR valve off mode; EGR: EGE valve open mode; AKT: a normal mode. Each will beO of EGR valve opening and closing modes of working condition2The concentration and NOx concentration are measured, and the NOx concentration and O of alpha and closed EGR valve can be obtained2Concentration; o to mark mixing point2A concentration model that can obtain the NOx concentration in the exhaust gas according to the formula (1);
establishing a model between NOx adsorption efficiency and exhaust temperature and adsorption quantity according to the NOx emission model value and the measured value of a nitrogen-oxygen sensor at the outlet end of the catalyst; the adsorption process is mainly NOx and barium carbonate (BaCO) in the coating on the catalyst support3) The reaction is carried out according to the following equation:
2NO+O2→2NO2
4NO2+2BaCO3+O2→2Ba(NO3)2+2CO2
the calculation formula of the exhaust temperature, the adsorption amount and the adsorption efficiency is as follows:
3. the strategy of claim 1, wherein in step S3, the catalyst regeneration process is performed by controlling the intake air quantity, intake pressure, fuel injection quantity of the piston exhaust stroke, injection angle and throttle valve value of the engine to make the ratio of the intake air quantity and the fuel injection quantity of the engine smaller than 14.5 of the theoretical air-fuel ratio of diesel, controlling the value of λ at about 0.92, generating a large amount of reducing agent CO by the engine, reducing NOx in the catalyst to N2 by the chemical property of CO reducibility, and keeping the whole reduction process within 10S, and the formula of λ is as follows:
4. the strategy of claim 1, wherein in step S4, the catalyst desulfurization process: firstly, increasing the fuel injection quantity, reducing the opening of a throttle valve, and increasing the internal temperature of the catalyst to 600-700 ℃ for heat preservation; secondly, switching the engine to a regeneration mode for desulfurization, wherein the internal temperature of the catalyst can be continuously increased in the desulfurization process; when the catalyst internal temperature rises to 700 ℃, the engine switches from the regeneration mode to the catalyst warm-up mode.
5. The strategy of claim 1, wherein in step S6, the temperature control method of the supercharger is as follows: firstly, introducing a part of exhaust gas into an air inlet system through an EGR valve in a circulating system to reduce the heat energy flowing through a supercharger; secondly, the cold end EGR valve is replaced by a hot end EGR valve, so that the exhaust temperature exceeding 600 ℃ can be borne; and thirdly, replacing the plastic air inlet connecting pipe with a cast iron air inlet connecting pipe.
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| CN (1) | CN111828187A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5746989A (en) * | 1995-08-14 | 1998-05-05 | Toyota Jidosha Kabushiki Kaisha | Method for purifying exhaust gas of a diesel engine |
| CN1436276A (en) * | 2000-08-14 | 2003-08-13 | 罗伯特-博希股份公司 | Method and model for modeling elimination phase of nitrogen oxide accumulating catalytic converter |
| EP1544430A1 (en) * | 2003-12-20 | 2005-06-22 | DaimlerChrysler AG | Method for operating a NOx storage catalyst |
| US20060107649A1 (en) * | 2002-08-26 | 2006-05-25 | Masayuki Kamikawa | Apparatus and method for clarifying exhaust gas of diesel engine |
| CN102465779A (en) * | 2010-11-18 | 2012-05-23 | 现代自动车株式会社 | Method for predicting NOx amount and exhaust system using the same |
| CN110792488A (en) * | 2019-09-29 | 2020-02-14 | 江铃汽车股份有限公司 | Exhaust aftertreatment system meeting national sixth requirement of light-duty diesel vehicle |
-
2020
- 2020-07-31 CN CN202010759894.8A patent/CN111828187A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5746989A (en) * | 1995-08-14 | 1998-05-05 | Toyota Jidosha Kabushiki Kaisha | Method for purifying exhaust gas of a diesel engine |
| CN1436276A (en) * | 2000-08-14 | 2003-08-13 | 罗伯特-博希股份公司 | Method and model for modeling elimination phase of nitrogen oxide accumulating catalytic converter |
| US20060107649A1 (en) * | 2002-08-26 | 2006-05-25 | Masayuki Kamikawa | Apparatus and method for clarifying exhaust gas of diesel engine |
| EP1544430A1 (en) * | 2003-12-20 | 2005-06-22 | DaimlerChrysler AG | Method for operating a NOx storage catalyst |
| CN102465779A (en) * | 2010-11-18 | 2012-05-23 | 现代自动车株式会社 | Method for predicting NOx amount and exhaust system using the same |
| CN110792488A (en) * | 2019-09-29 | 2020-02-14 | 江铃汽车股份有限公司 | Exhaust aftertreatment system meeting national sixth requirement of light-duty diesel vehicle |
Non-Patent Citations (3)
| Title |
|---|
| 刘磊: "EGR 与 LNT 协同控制稀燃汽油机 NOx 排放试验及仿真研究", 《中国博士学位论文全文数据库工程科技Ⅱ辑》 * |
| 罗璞: "柴油机控制系统的开发和标定", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 * |
| 范振阳: "EGR和VVT在汽油机涡轮增压中的应用", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 * |
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Application publication date: 20201027 |