CN114810396B - Engine control device, method for adjusting nitrogen oxide conversion rate and automobile - Google Patents
Engine control device, method for adjusting nitrogen oxide conversion rate and automobile Download PDFInfo
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- CN114810396B CN114810396B CN202110627480.4A CN202110627480A CN114810396B CN 114810396 B CN114810396 B CN 114810396B CN 202110627480 A CN202110627480 A CN 202110627480A CN 114810396 B CN114810396 B CN 114810396B
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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
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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
- F02D41/024—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus
- F02D41/025—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus by changing the composition of the exhaust gas, e.g. for exothermic reaction on exhaust gas treating apparatus
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Abstract
The invention provides an engine control device, a method for adjusting nitrogen oxide conversion rate and an automobile, wherein the engine control deviceThe device is used for controlling CO by regulating and controlling the main fuel injection quantity and main fuel injection timing of the engine 2 The emission ratio in the exhaust is used to adjust the nitrogen oxide conversion in the LNT. The invention obtains CO through the ECU of the engine 2 The exhaust emission ratio in the tail gas is judged, and whether the exhaust emission ratio is larger than/equal to a preset threshold value or not is judged; starting the engine control device when the emission amount duty ratio is greater than/equal to a preset threshold; the main injection quantity and the main injection timing of the engine are adjusted by the engine control device to enable CO to be generated 2 The emission duty cycle in the exhaust is less than a preset threshold to achieve further improvement in NOx conversion efficiency in the LNT.
Description
Technical Field
The invention belongs to the field of automobiles, and particularly relates to an engine control device, a method for adjusting nitrogen oxide conversion rate and an automobile.
Background
In the emission regulations of automobiles (national 6 emission regulations), NO X Is subject to more stringent requirements. Because the diesel engine is oxygen-enriched combustion, the tail gas of the automobile contains a large amount of NO X . Thus, the person skilled in the art is faced with minimizing NO in the exhaust gas X Content problems.
In the prior art, in order to reduce NO X To those skilled in the art, an LNT (Lean NOx Trap) was developed and successfully applied to automobiles. The LNT is mainly used for trapping and releasing NOx and reducing NOx so as to achieve the purpose of purifying the NOx.
However, in the actual application process of the LNT, CO exists in the tail gas 2 The conversion efficiency of the LNT to NOx is reduced. Thus, how to reduce CO in the tail gas 2 The impact on the conversion efficiency of the LNT, the ability to fully release the LNT's conversion of NOx, is a critical issue that the LNT needs to address in engineering applications.
Currently, some LNT catalyst manufacturers apply dedicated catalyst formulations to solve the above problem, but switching catalyst formulations results in increased LNT development costs. Thus, there is a need for an efficient, rational and low cost solution to the above problems.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides an engine control device, a method for adjusting the conversion rate of nitrogen oxides and an automobile, and the method further improves the conversion efficiency of LNT to NOx. The specific contents are as follows:
in a first aspect, the present invention provides an engine control apparatus for controlling an engine by tuningControlling main injection quantity and main injection timing of engine to control CO 2 The emission ratio in the exhaust is used to adjust the nitrogen oxide conversion in the LNT.
Preferably, the engine control device is controlled by an engine ECU control system.
In a second aspect, the present invention provides a method of regulating nitrogen oxide conversion in an LNT, the method being implemented based on the engine control device, the method comprising:
acquisition of CO 2 The exhaust emission ratio in the tail gas is judged, and whether the exhaust emission ratio is larger than/equal to a preset threshold value or not is judged;
starting an engine control device when the emission duty ratio is greater than/equal to the preset threshold;
and regulating and controlling main fuel injection quantity and main fuel injection timing of the engine through the engine control device to enable the discharge quantity duty ratio to be smaller than the preset threshold value.
Preferably, the obtaining of CO 2 The exhaust emission ratio in the exhaust gas comprises: sweeping the engine speed and the engine torque to obtain CO under the working condition corresponding to the engine speed and the engine torque 2 Is used as a discharge rate.
Preferably, the range of sweeping the engine speed is 1200rpm-2800rpm, and the step size is 100rpm-400rpm.
Preferably, the range of sweeping the engine torque is 50Nm-300Nm, and the step size is 25Nm-50Nm.
Preferably, the preset threshold is the CO under the condition that the engine speed corresponds to the engine torque 2 The emission duty cycle in the exhaust gas affects the highest value of the LNT to NOx conversion efficiency.
Preferably, the highest value is: the LNT has a conversion efficiency of 85% for NOx and corresponding CO 2 The discharge amount is a ratio.
Preferably, in said capturing CO 2 Before the exhaust emission ratio in the exhaust gas is determined, and whether the exhaust emission ratio is greater than or equal to a preset threshold value, the method further includes: acquiring the working state of the LNT and judgingWhether the working state of the LNT is DeNOx;
wherein when the working state of the LNT is DeNOx, the CO acquisition is executed 2 The exhaust emission in the exhaust gas is in proportion.
In a third aspect, the present invention provides an automobile provided with an engine control device.
The engine control device provided by the invention has the beneficial effects that: the engine control device provided by the invention can directly regulate and control the main fuel injection quantity and main fuel injection timing of the engine by means of the control system of the engine ECU, and realize accurate control of CO 2 The emission in the exhaust is in a ratio to further achieve an increase in nitrogen oxide conversion in the LNT. The utilization rate of the LNT is improved.
In addition, the method for adjusting the conversion rate of the nitrogen oxides has the following beneficial effects:
(1) In the method for adjusting the conversion rate of the nitrogen oxides, the rotation speed, the torque and the CO of the engine can be directly realized by the control system of the ECU of the engine 2 And (5) accurately identifying and judging the discharge amount. Therefore, the method does not need to additionally increase hardware cost on the electric control engine, and has the advantages of low application cost and easy popularization.
(2) In the method for adjusting the conversion rate of the nitrogen oxides, the ECU of the engine recognizes that the engine and the LNT are in CO 2 After the unreasonable emission area, the engine control device can be automatically activated, and the CO is reduced by adjusting the main fuel injection quantity and main fuel injection timing parameters of the engine 2 And the output is improved, the conversion efficiency of the LNT to NOx is finally improved, and the high intellectualization and integration of the whole control strategy and the control process are realized.
(3) Compared with the prior art, partial catalyst manufacturers can apply special catalyst formulas to avoid CO as much as possible 2 Affecting the NOx conversion efficiency of the LNT, but switching catalyst formulations can result in increased development costs for the LNT, and changing catalyst formulations at a later stage of the project development can result in extended development cycles. The method for adjusting the conversion rate of the nitrogen oxides provided by the invention is realized by the control system of the engine ECUThe invention can be realized, and is reasonable, reliable and unique. More accords with the sustainable development of environmental protection purpose.
(4) The method for adjusting the conversion rate of the nitrogen oxides provided by the invention has the advantages that the related system parameters can be flexibly configured to realize the matching of adjustable parameters of engines of different factories and LNT systems, and the openness and the flexibility are realized.
Drawings
FIG. 1 is a schematic diagram illustrating the operating principle of an LNT for storing NOx during lean burn periods in accordance with an embodiment of the present invention;
FIG. 2 shows different COs according to an embodiment of the invention 2 Schematic of the effect of content on NOx conversion efficiency of the LNT catalytic converter;
fig. 3 shows a schematic diagram of an engine start control device according to an embodiment of the present invention.
Detailed Description
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description. The following describes in detail the examples of the present invention, which are implemented on the premise of the technical solution of the present invention, and detailed embodiments and specific operation procedures are given, but the scope of protection of the present invention is not limited to the following examples.
To solve the above-mentioned problems of the prior art, the present inventors have made an intensive knowledge of the existing LNT, in which nitrogen oxides (NO X ) Purging, trapping and releasing are accomplished by the LNT. Noble metal Pt is generally used as a catalytic active component of the LNT, alkali and/or alkaline earth metal oxides are used as a storage component, and gamma-Al with large specific surface area is used 2 O 3 As a carrier to increase the dispersibility of the active component and the storage component. Typical LNT catalyst systems were the earliest Pt/BaO/Al developed and marketed by Toyota corporation 2 O 3 A catalyst system. Taking the catalyst system as an example to illustrate the standard circulation process of the LNT catalyst, the working process of the LNT catalyst system for purifying, capturing and releasing NOx in automobile exhaust is specifically divided into 2 working phases of lean burn and rich burn. Wherein, NOx is stored on the LNT catalyst in the lean burn period, and FIG. 1 shows a schematic diagram of the working principle of the LNT for storing NOx in the lean burn period according to the embodiment of the invention; NOx stored during the rich phase is reduced to N again 2 . The working principle is as follows:
first, when the engine is in a lean burn phase, NO is oxidized to N0 on the noble metal active site Pt during a longer (about 60-90 seconds) lean burn phase 2 Subsequently N0 2 Is unstable with the adjacent alkaline component BaO (BaO is easy to be combined with CO) 2 Reaction to form stable BaCO 3 ) Reacting to generate nitrate and storing; the specific reaction is shown in the reaction formula (1-2).
The reaction occurring during storage is as follows:
2NO + O 2 →2NO 2 （1）
2BaCO 3 + 4NO 2 + O 2 → 2Ba(NO 3 ) 2 + 2CO 2 （2）
when the engine is switched to a rich atmosphere, the reducing components HC, CO and H in the exhaust gas are reduced in a short time (about 3-5 seconds) 2 The concentration of the nitrate increases rapidly, the nitrate stored in the reducing atmosphere is unstable in thermodynamics and can release N0 rapidly 2 And is reduced to N by a reducing agent in a catalytic reaction mode 2 Simultaneously, the catalyst storage site is regenerated, and the specific reaction is shown in the following reaction formula (3-6):
the reaction that takes place on the catalyst during the release process is as follows:
Ba(NO 3 ) 2 → BaO + NO 2 （3）
2CO + 4NO 2 → N 2 + 4CO 2 （4）
10NO 2 + 8HC→ 8CO 2 + 5N 2 + 4H 2 O（5）
BaO + CO 2 →BaCO 3 （6）
thus, a standard loop process for the LNT is completed. It can be determined by the above-described cycling process that an engine equipped with a Lean NOx catalytic converter (LNT) needs to be periodically switched between Lean and rich to achieve the LNT adsorption (storage) and reduction (release) processes.
On the basis, the inventor combines the working principle of LNT to further explore CO 2 The effect of the gas on the NOx conversion efficiency of the LNT catalytic converter.
FIG. 2 shows different COs according to an embodiment of the invention 2 The effect of level on the NOx conversion efficiency of the LNT catalytic converter is schematically indicated. From fig. 2, the inventors concluded that:
(1) CO present in engine exhaust 2 Can affect LNT operating efficiency. And, in a certain range (NOx conversion efficiency is 85% or more) with CO 2 The NOx conversion efficiency in the LNT is continuously decreasing with increasing duty cycle in the exhaust.
（2）CO 2 The NOx leakage amount is increased in the presence of the catalyst than in the theoretical condition, and the average conversion efficiency of NOx in the LNT is about 85%. When the average conversion efficiency of NOx in the LNT is below this value, then the CO is followed 2 The conversion efficiency of NOx in the LNT tends to be the same.
The inventor of the invention realizes the aim of further improving the conversion efficiency of NOx in the LNT in order to avoid the influence of CO2 in the tail gas on the conversion efficiency of NOx in the LNT. The inventors fully utilized the above search and proposed the following technical ideas: and when the emission amount ratio is larger than/equal to a preset threshold value, based on an additionally arranged engine control device, regulating and controlling the emission amount ratio of CO2 in the tail gas to ensure that the emission amount ratio of CO2 in the tail gas is smaller than the preset threshold value, so that the emission amount ratio of CO2 in the tail gas is kept in a range which does not influence the conversion efficiency of the LNT to NOx, and further improving the conversion efficiency of the NOx in the LNT.
Based on the technical idea, a first aspect of the present invention provides an engine control device for controlling CO by regulating and controlling a main injection amount and a main injection timing of an engine 2 The emission ratio in the exhaust is used to adjust the nitrogen oxide conversion in the LNT.
In particular, the engine control device is controlled by the engine ECU, and fig. 3 showsThe strategy diagram for starting the engine control device provided by the embodiment of the invention is provided; as shown in fig. 3, in the embodiment of the present invention, the control system of the engine ECU will control CO under the conditions of the LNT state, the engine speed and the engine torque 2 The emission amount of the engine is accurately identified and judged, and when the LNT state is judged to be DeNOx, the CO is obtained under the working condition that the engine speed corresponds to the engine torque 2 Is filled into corresponding CO 2 In MAP discharge, CO is further discharged 2 CO in MAP emissions 2 Ratio of the emission amount to CO 2 Comparing the emission threshold, when the emission ratio is determined to be greater than/equal to CO 2 When the emission amount is threshold, the SURP mode of the engine (control device) is started, and the main injection amount MAP and the main injection timing MAP of the engine are corrected by adjusting the main injection amount and the main injection timing (combustion parameter) of the engine. The engine controls CO by executing the corrected combustion parameter value 2 The emission in the tail gas is in proportion, so that the conversion efficiency of the LNT to NOx is improved.
In the embodiment of the invention, the engine control device is preferably controlled by an engine ECU control system.
In a second aspect, the present invention provides a method of regulating nitrogen oxide conversion in an LNT, the method being implemented based on an engine control device, the method comprising:
acquisition of CO 2 The emission amount ratio in the tail gas is judged, and whether the emission amount ratio is larger than/equal to a preset threshold value or not is judged;
starting the engine control device when the emission amount duty ratio is greater than/equal to a preset threshold;
the main fuel injection quantity and the main fuel injection timing of the engine are regulated and controlled by the engine control device, so that the discharge quantity duty ratio is smaller than a preset threshold value.
In specific implementation, the main injection quantity and the main injection timing of the engine are regulated and corrected through a control system of the engine ECU.
In the embodiment of the invention, preferably, CO is obtained 2 The exhaust emission ratio in the exhaust gas comprises: sweeping the engine speed and the engine torque to obtain the engine speed and the engine torqueCO under the working condition corresponding to torque 2 Is used as a discharge rate.
During implementation, the control system of the engine ECU scans the engine speed and the engine torque to obtain CO under the working conditions corresponding to the engine speed and the engine torque 2 Is filled into corresponding CO 2 And discharging MAP.
In the embodiment of the invention, the range of sweeping the engine speed is preferably 1200rpm-2800rpm, and the step size is preferably 100rpm-400rpm.
In the embodiment of the invention, the range of sweeping the engine torque is preferably 50Nm-300Nm, and the step size is preferably 25Nm-50Nm.
In specific implementation, different engine speeds and engine torques are used for CO 2 The contribution of emissions was different for the measurement of CO 2 The emission amount of the engine is divided into different points, the engine speed and the torque are considered, the upper limit and the lower limit of the engine speed and the torque are considered, the speed range is specially set to 1200-2800 rpm, and the torque range is 50-300 Nm.
In the embodiment of the present invention, preferably, the preset threshold is CO under the working condition that the engine speed corresponds to the engine torque 2 The emission duty cycle in the exhaust gas affects the highest value of the LNT to NOx conversion efficiency.
In the embodiment of the present invention, preferably, the highest value is: at 85% conversion efficiency of LNT to NOx, the corresponding CO 2 The discharge amount is a ratio.
In practice, the inventors have intensively studied about different COs 2 The content has different effects on the NOx conversion efficiency of the LNT, and the following results: (1) CO present in engine exhaust 2 Can affect LNT operating efficiency. And, in a certain range (NOx conversion efficiency is 85% or more) with CO 2 The NOx conversion efficiency in the LNT is continuously decreasing with increasing duty cycle in the exhaust. (2) CO 2 The NOx leakage amount is increased in the presence of the catalyst than in the theoretical condition, and the average conversion efficiency of NOx in the LNT is about 85%. When the average conversion efficiency of NOx in the LNT is below this value, then the CO is followed 2 The conversion efficiency of NOx in the LNT tends to be the same.
Based on the aboveIn conclusion, the inventor judges that CO under the working condition that the engine speed corresponds to the engine torque when the NOx conversion efficiency in the LNT is 85 percent 2 The amount of emissions in the exhaust gas is taken as a preset threshold. Under the working condition that the engine speed corresponds to the engine torque, CO 2 When the emission amount in the tail gas exceeds the preset threshold value, the engine control device is used for regulating and controlling the main fuel injection amount and main fuel injection timing of the engine to control the CO 2 The exhaust emission ratio in the tail gas is adjusted (reduced), so that the aim of improving the NOx conversion efficiency in the LNT can be fulfilled.
In the embodiment of the invention, preferably, in the process of acquiring CO 2 Before the exhaust emission ratio in the exhaust gas is determined, and whether the exhaust emission ratio is greater than or equal to a preset threshold value, the method further comprises: acquiring the working state of the LNT, and judging whether the working state of the LNT is DeNOx;
wherein, when the working state of the LNT is DeNOx, the CO acquisition is performed 2 The exhaust emission in the exhaust gas is in proportion.
In particular, the engine ECU control system first determines the operating state of the LNT due to CO 2 Mainly affecting the rich phase (release process) of the LNT, the stored NOx is reduced to N 2 Therefore, the engine needs to make a determination of the operating state of the LNT. When the engine determines that the working state of the LNT is DeNOx, continuing to acquire CO 2 The exhaust emission in the exhaust gas is in proportion.
In a third aspect, the present invention provides an automobile, the automobile being provided with an engine control device.
In order for those skilled in the art to better understand the method for adjusting nitrogen oxide conversion in the embodiments of the present invention, the method for adjusting nitrogen oxide conversion in the embodiments of the present invention will be described below by way of specific examples.
Example 1
In the embodiment, the main fuel injection quantity and the main fuel injection timing of the engine are regulated and controlled by the engine control device, so that CO is reduced 2 The emission ratio in the tail gas is reduced, so that CO in the tail gas is reduced 2 The effect on the conversion efficiency of the LNT is achieved, and the purpose of improving the conversion efficiency of the LNT to NOx is achieved. Specific regulation of nitrogen oxides in LNTThe conversion was carried out as follows:
the engine ECU control system monitors the current working state of the LNT, and when the working state of the LNT is monitored to be in a DeNOx state, the engine ECU control system performs the point selection work on the engine speed and the engine torque. Wherein, the range of the engine speed selection point is 1200rpm-2800rpm, and the step length is 400rpm; the engine torque selection point ranges from 50Nm to 300Nm, and the step size is 50Nm.
According to the step length, the actual measurement main injection quantity of the vehicle engine and the actual measurement main injection timing of the vehicle engine are obtained by sweeping the points of different engine speeds and engine torques under the corresponding working conditions. At the same time, the actual measurement CO of the vehicle engine under the working conditions of different rotating speeds and torque is also obtained 2 The emission ratio (%) (CO) 2 Discharge MAP). Specific data are shown in tables 1, 2 and 3.
Table 1: actual measurement main fuel injection quantity of vehicle engine under different rotation speed and torque working conditions
Table 2: actual measurement main injection timing of vehicle engine under different rotation speed and torque working conditions
Table 3: actual measurement CO of vehicle engine under different rotation speed and torque working conditions 2 Exhaust MAP
Further, when the conversion efficiency of NOx in the LNT corresponding to the torque condition at different rotation speeds in Table 3 reaches 85%, CO 2 The ratio of the emission in the exhaust gas is used as a corresponding preset threshold value (obtained by automatic measurement and calculation of an engine ECU) and is compared with the actual measurement CO of the vehicle engine in the table 3 2 The ratio of the discharge amount of (c) is compared. For the excesses identified in Table 3 aboveThreshold operating point (bold operating point in Table 3) to reduce CO 2 And (3) aiming at the emission amount of the tail gas in the duty ratio, correcting the main fuel injection amount and the main fuel injection timing for the working condition points exceeding the threshold value by utilizing the correction coefficients of the corresponding working condition points obtained by the engine ECU. The specific correction coefficients are shown in tables 4 and 5.
Table 4: correction coefficient of actual measured main fuel injection quantity of engine under different rotation speed and torque working conditions
Table 5: correction coefficient of actual measurement main injection timing of engine under different rotation speed and torque working conditions
And (3) correcting the main injection quantity and the main injection timing of the working point exceeding the threshold according to the correction coefficients obtained in the table 4 and the table 5 to obtain corresponding main injection quantity correction MAP and main injection timing correction MAP, wherein the main injection quantity correction MAP and the main injection timing correction MAP are combustion parameters actually operated after the LNT enters the SUPR mode of the engine. The modified MAP for the main injection amount and the modified MAP for the main injection timing for the typical engine SUPR mode are shown in tables 6 and 7, respectively:
table 6: main fuel injection amount MAP corrected by engine control device
Table 7: main injection timing MAP corrected by engine control device
Thus, for CO 2 At each operating point where the exhaust emission ratio exceeds a preset threshold, the engine ECU executes the corrected main injection amount and the corrected main injection timing by the engine control device, namelyRealize the CO corresponding to the working condition point 2 The emission duty cycle in the exhaust gas is reduced below a preset threshold.
Example 2
In the embodiment, the main fuel injection quantity and the main fuel injection timing of the engine are regulated and controlled by the engine control device, so that CO is reduced 2 The emission ratio in the tail gas is reduced, so that CO in the tail gas is reduced 2 The effect on the conversion efficiency of the LNT is achieved, and the purpose of improving the conversion efficiency of the LNT to NOx is achieved. The specific implementation method for adjusting the nitrogen oxide conversion rate in the LNT is as follows:
the engine ECU control system monitors the current working state of the LNT, and when the working state of the LNT is monitored to be in a DeNOx state, the engine ECU control system performs the point selection work on the engine speed and the engine torque. Wherein, the range of the engine speed selection point is 1200rpm-2800rpm, and the step length is 100rpm; the engine torque selection point ranges from 50Nm to 300Nm, and the step size is 25Nm.
According to the step length, the actual measurement main injection quantity of the vehicle engine and the actual measurement main injection timing of the vehicle engine are obtained by sweeping the points of different engine speeds and engine torques under the corresponding working conditions. At the same time, the actual measurement CO of the vehicle engine under the working conditions of different rotating speeds and torque is also obtained 2 The emission ratio (%) (CO) 2 Discharge MAP). Specific data are shown in tables 8, 9 and 10.
Table 8: actual measurement main fuel injection quantity of vehicle engine under different rotation speed and torque working conditions
Table 9: actual measurement main injection timing of vehicle engine under different rotation speed and torque working conditions
Table 10: actual measurement CO of vehicle engine under different rotation speed and torque working conditions 2 Exhaust MAP
Further, when the conversion efficiency of NOx in LNT reaches 85% under different rotation speed and torque conditions in Table 10, CO 2 The ratio of the exhaust emissions in the exhaust gas is used as a corresponding preset threshold (obtained by automatic measurement and calculation of an engine ECU) and is compared with the actual measurement CO of the vehicle engine in Table 10 2 The ratio of the discharge amount of (c) is compared. For the above-identified threshold-exceeding operating points in Table 10 (see bolded operating points in Table 10) to reduce CO 2 And (3) aiming at the emission amount of the tail gas in the duty ratio, correcting the main fuel injection amount and the main fuel injection timing for the working condition points exceeding the threshold value by utilizing the correction coefficients of the corresponding working condition points obtained by the engine ECU. The specific correction coefficients are shown in tables 11 and 12.
Table 11: correction coefficient of actual measured main fuel injection quantity of engine under different rotation speed and torque working conditions
Table 12: correction coefficient of actual measurement main injection timing of engine under different rotation speed and torque working conditions
And according to the correction coefficients of the table 11 and the table 12, correcting the main injection quantity and the main injection timing of the working condition point exceeding the threshold value to obtain corresponding main injection quantity correction MAP and main injection timing correction MAP, wherein the main injection quantity correction MAP and the main injection timing correction MAP are combustion parameters actually operated after the LNT enters the SUPR mode of the engine. The modified MAP for the main injection amount and the modified MAP for the main injection timing for the typical engine SUPR mode are shown in tables 13 and 14, respectively:
table 13: main fuel injection amount MAP corrected by engine control device
Table 14: main injection timing MAP corrected by engine control device
Thus, for CO 2 At each working point that the emission amount duty ratio in the tail gas exceeds a preset threshold value, the engine ECU executes the main injection amount corrected by the engine control device and the corrected main injection timing, namely, CO corresponding to the working point is realized 2 The emission duty cycle in the exhaust gas is reduced below a preset threshold.
The engine control device, the method for adjusting the conversion rate of nitrogen oxides and the automobile provided by the invention are described in detail, and specific examples are applied to illustrate the principle and the implementation mode of the invention, and the description of the examples is only used for helping to understand the method and the core idea of the invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.
Claims (9)
1. An engine control device is characterized in that the engine control device is used for controlling CO by regulating and controlling main fuel injection quantity and main fuel injection timing of an engine 2 Emission duty cycle in exhaust gas to adjust nitrogen oxide conversion in LNT, the CO 2 The emission amount duty ratio in the tail gas is that CO under the working condition corresponding to the engine speed and the engine torque is obtained by sweeping the engine speed and the engine torque 2 Is determined by the discharge rate.
2. The engine control device according to claim 1, characterized in that the engine control device is controlled by an engine ECU control system.
3. A method of regulating nitrogen oxide conversion in an LNT, the method being based on the engine control device of claim 1, the method comprising the steps of:
acquiring the emission rate of CO2 in the tail gas, judging whether the emission rate is larger than or equal to a preset threshold value, and acquiring the emission rate of CO2 in the tail gas comprises the following steps: sweeping the engine speed and the engine torque to obtain the CO2 emission duty ratio under the working condition corresponding to the engine speed and the engine torque;
starting an engine control device when the emission duty ratio is greater than/equal to the preset threshold;
and regulating and controlling main fuel injection quantity and main fuel injection timing of the engine through the engine control device to enable the discharge quantity duty ratio to be smaller than the preset threshold value.
4. A method according to claim 3, wherein the sweeping of the engine speed is in the range 1200rpm-2800rpm, with a step size of 100rpm-400rpm.
5. A method according to claim 3, wherein the sweep of engine torque is in the range 50Nm to 300Nm, with a step size of 25Nm to 50Nm.
6. A method according to claim 3, wherein the preset threshold is a highest value of the CO2 emission ratio in the exhaust gas affecting the conversion efficiency of LNT to NOx under the condition that the engine speed corresponds to the engine torque.
7. The method of claim 6, wherein the highest value is: the LNT has a corresponding CO2 emission ratio at 85% conversion efficiency to NOx.
8. The method of claim 3, wherein prior to said obtaining the CO2 emissions ratio in the exhaust gas and determining whether the emissions ratio is greater than or equal to a preset threshold, the method further comprises: acquiring the working state of an LNT, and judging whether the working state of the LNT is DeNOx;
and when the working state of the LNT is DeNOx, executing the acquisition of the emission ratio of CO2 in the tail gas.
9. An automobile, wherein the engine control device according to claim 1 is provided in the automobile.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10117434A1 (en) * | 2001-04-03 | 2002-10-10 | Volkswagen Ag | Method for controlling an operating mode of a lean-burn internal combustion engine |
| DE10160704B4 (en) * | 2001-12-11 | 2013-07-18 | Volkswagen Ag | Method for operating exhaust gas purification devices |
| DE102012202679B3 (en) * | 2012-02-22 | 2013-03-14 | Ford Global Technologies, Llc | Method for introduction and maintenance of preset sub-stoichiometric constant for operation of internal combustion engine of vehicle, involves using electric machine drive as auxiliary drive to satisfy requested increased power demand |
| CN102943715B (en) * | 2012-11-27 | 2016-01-20 | 东风汽车公司 | A kind of emission control systems of motor and using method thereof |
| GB2531368B (en) * | 2015-02-11 | 2017-02-01 | Ford Global Tech Llc | A method for emissions regulation |
| US9631565B2 (en) * | 2015-09-15 | 2017-04-25 | Hyundai Motor Company | Control method for improving nitrogen oxide purification performance |
| GB2578155B (en) * | 2018-10-19 | 2021-01-13 | Delphi Automotive Systems Lux | Method of controlling vehicle emissions |
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