CN108194183A - Obtain the method and electronic control unit of the SCR ammonia loss in engine stopping process - Google Patents

Obtain the method and electronic control unit of the SCR ammonia loss in engine stopping process Download PDF

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Publication number
CN108194183A
CN108194183A CN201711448102.XA CN201711448102A CN108194183A CN 108194183 A CN108194183 A CN 108194183A CN 201711448102 A CN201711448102 A CN 201711448102A CN 108194183 A CN108194183 A CN 108194183A
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scr
ammonia
temperature
engine
nitrogen oxides
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CN108194183B (en
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王龙晓
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Weichai Power Co Ltd
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Weichai Power Co Ltd
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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
    • 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
    • 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
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
    • 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

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

The embodiment of the present application discloses a kind of method of SCR ammonia loss obtained in engine stopping process; this method has fully considered the factor that ammonia loss of the absorption on SCR carriers is influenced in stopping process; the factor not only includes downtime, further includes after processing is shut down and remains in nitrogen oxides and SCR temperature in SCR babinets.The ammonia carrying capacity consumed during the nitrogen oxides remained in SCR babinets because processing in engine stopping process can be got based on multiple factor and occur in real time in stopping process, with the relevant amount of ammonia slip of SCR temperature, ammonia carrying capacity and escape amount based on the consumption be accurately obtained in engine stopping process SCR ammonia loss.In addition, the embodiment of the present application also discloses a kind of electronic control unit.

Description

Obtain the method and electronic control unit of the SCR ammonia loss in engine stopping process
Technical field
This application involves engines tail gas processing system more particularly to a kind of SCR ammonia obtained in engine stopping process The method and electronic control unit of loss.
Background technology
SCR technology (SCR, Selective Catalytic Reduction) is for exhaust gas from diesel vehicle Nitrogen oxides NO in dischargexA treatment process, i.e., under the effect of the catalyst, reducing agent ammonia or urea are sprayed into, tail gas In NOxIt is reduced into nitrogen N2With water H2O, so as to achieve the purpose that not only energy saving but also emission reduction.This technology is European mainstream technology Route, the long-distance load-carrying vehicle in Europe and motorbus almost all use this technology.
After engine is shut down, adsorb the ammonia on SCR carriers and have a certain amount of loss.It is shut down to get engine There is obtaining at present the technology of the SCR ammonia loss in engine stopping process in the SCR ammonia loss of process.Wherein, it is a kind of existing Acquisition engine stopping process SCR ammonia loss method be that the SCR ammonia in the stopping process is determined according to downtime Waste.However, the result of the SCR ammonia loss of the engine stopping process obtained by this method is inaccurate, SCR objects are influenced The calculated value of model is managed, the ammonia carrying capacity of SCR physical model calculatings is caused not to be inconsistent with the ammonia carrying capacity adsorbed in practical SCR carriers, into And lead to the increase of adaptive and NH_3 leakage detection function triggering frequency.
Invention content
In view of this, this application provides a kind of methods and electronics of the loss of SCR ammonia obtained in engine stopping process Control unit is lost with the SCR ammonia being accurately obtained in engine stopping process.
In order to solve the above-mentioned technical problem, the application employs following technical solution：
A kind of method of SCR ammonia loss obtained in engine stopping process, including：
Obtain SCR mean temperatures, environment temperature and the matter for remaining in the nitrogen oxides in SCR that engine shuts down the moment Amount；
According to the SCR mean temperatures and environment temperature, SCR temperature attenuation curve is obtained；
The residual is handled according to the Mass Calculation of the SCR temperature attenuation curve and the nitrogen oxides remained in SCR The ammonia carrying capacity that nitrogen oxides in SCR is consumed；According to SCR temperature attenuation curve and downtime, calculate engine and stop The amount of ammonia slip of machine process；
The ammonia carrying capacity of the consumption is added with amount of ammonia slip, obtained adduction is the SCR ammonia in engine stopping process Loss.
Optionally, it is described according to the SCR mean temperatures and environment temperature, obtain SCR temperature attenuation curve, specific packet It includes：
MAP chart table is searched according to the SCR mean temperatures and environment temperature, to obtain the temperature damping of the SCR temperature Curve, according to different SCR temperature and environment temperature, calibration obtains the MAP chart table in advance.
Optionally, it is described according to the SCR mean temperatures and environment temperature, obtain SCR temperature attenuation curve, specific packet It includes：
According to the SCR temperature model built in advance, SCR temperature attenuation curve is obtained.
Optionally, the quality for remaining in the nitrogen oxides in SCR is obtained, is specifically included：
Obtain the exhaust gas mass flow that engine shuts down the moment, the concentration of the nitrogen oxides in tail gas and SCR babinets Volume；
According to the exhaust gas mass flow, the concentration of nitrogen oxides and the volume of SCR babinets, estimation in tail gas remain The quality of nitrogen oxides in SCR.
Optionally, described to be added the ammonia carrying capacity of the consumption with amount of ammonia slip, obtained adduction was shut down for engine After SCR ammonia loss in journey, further include：
When being again started up after engine shutdown, SCR ammonia loss corrections SCR's in the engine stopping process Current ammonia carrying capacity.
A kind of electronic control unit, including：
First acquisition module shuts down the SCR mean temperatures at moment, environment temperature and remains in SCR for obtaining engine The quality of interior nitrogen oxides；
Second acquisition module, for according to the SCR mean temperatures and environment temperature, obtaining SCR temperature attenuation curve；
First computing module, for according to the SCR temperature attenuation curve and remaining in SCR
Second computing module, for according to SCR temperature attenuation curve and downtime, calculating engine stopping process Amount of ammonia slip；
Module is summed it up, the ammonia carrying capacity of the consumption is added with amount of ammonia slip, obtained adduction is engine stopping process In SCR ammonia loss.
Optionally, second acquisition module is specifically used for：
MAP chart table is searched according to the SCR mean temperatures and environment temperature, to obtain the temperature damping of the SCR temperature Curve, according to different SCR temperature and environment temperature, calibration obtains the MAP chart table in advance.
Optionally, second acquisition module is specifically used for：
According to the SCR temperature model built in advance, SCR temperature attenuation curve is obtained.
Optionally, first computing module specifically includes：
Acquisition submodule, for obtaining the exhaust gas mass flow that engine shuts down the moment, nitrogen oxides in tail gas it is dense The volume of degree and SCR babinets；
Estimate submodule, for according to the exhaust gas mass flow, the concentration of nitrogen oxides and SCR babinets in tail gas Volume, estimation remains in the quality of nitrogen oxides in SCR.
Optionally, the electronic control unit further includes：
Correcting module, for when being again started up after engine is shut down, according to the SCR ammonia in the engine stopping process The current ammonia carrying capacity of loss correction SCR.
Compared to the prior art, the application has the advantages that：
After being shut down due to engine, certain nitrogen oxides, and SCR catalyst at this time are still remained in SCR babinets Temperature it is higher, remaining nitrogen oxides can with absorption on SCR carriers ammonia reaction, lead to the loss of SCR ammonia carrying capacity.Together When, after being shut down due to engine, a part of ammonia adsorbed on SCR carriers can be escaped in real time, lead to the damage of SCR ammonia carrying capacity Consumption.And amount of ammonia slip is related to SCR temperature, and SCR temperature is higher, and amount of ammonia slip is bigger, and SCR temperature is lower, and amount of ammonia slip is got over It is small.In this way, the SCR ammonia loss in engine stopping process includes two parts：Processing residual nitrogen oxides consumption ammonia carrying capacity with And occur in real time in stopping process, with the relevant amount of ammonia slip of SCR temperature.
Based on this, the method for SCR ammonia loss provided by the embodiments of the present application obtained in engine stopping process is fully examined Considered influences the factor of ammonia loss of the absorption on SCR carriers in stopping process, which not only includes downtime, also wrap It includes after processing is shut down and remains in nitrogen oxides and SCR temperature in SCR babinets.It can be accurately obtained based on multiple factor The ammonia carrying capacity consumed during the nitrogen oxides remained in SCR babinets because processing in engine stopping process and and SCR temperature Relevant amount of ammonia slip, ammonia carrying capacity and escape amount based on the consumption can be relatively accurately got in engine stopping process SCR ammonia loss.
Description of the drawings
In order to which the specific implementation of the application is expressly understood, used when the application specific embodiment is described below Attached drawing do a brief description.It should be evident that these attached drawings are only the section Examples of the application.
Fig. 1 is the method flow signal of the SCR ammonia loss in acquisition engine stopping process provided by the embodiments of the present application Figure；
Fig. 2 is SCR temperature attenuation curve schematic diagram provided by the embodiments of the present application；
Fig. 3 is that MAP chart provided by the embodiments of the present application represents to be intended to；
Fig. 4 is electronic control unit structure diagram provided by the embodiments of the present application.
Specific embodiment
To make present invention purpose, technical solution and technique effect clearer, complete, below in conjunction with the accompanying drawings in detail The specific embodiment of the application is described.
Before the specific embodiment of the application is introduced, SCR system is introduced first.
SCR is for nitrogen oxides NO in exhaust gas from diesel vehicle dischargexA treatment process, i.e., in the effect of catalyst Under, reducing agent ammonia or urea are sprayed into, the NO in tail gasxIt is reduced into nitrogen N2With water H2O, it is not only energy saving but also emission reduction so as to reach Purpose.This technology is European mainstream technology route, and the long-distance load-carrying vehicle in Europe and motorbus almost all use this technology.
The basic functional principle of SCR system is as follows：Tail gas enters exhaust fixed tube after being come out from turbine, pacify on fixed tube Equipped with urea measuring and injecting device, aqueous solution of urea is sprayed into, urea generates NH after hydrolysis and pyrolytic reaction occur at high temperature3, NH is utilized on SCR system catalyst surface3Restore NOX, discharge N2.Under normal circumstances, 5L can be lost while 100L fuel oils are lost Liquid area aqueous solution.
The main chemical reactions occurred in SCR are as follows：
Hydrolysis of urea：
(NH2)2CO+H2O→2NH3+CO2
NOXReduction：
NO+NO2+2NH3→2N2+3H2O
NH3Oxidation：
4NH3+3O2→2N2+6H2O
The complicated physical and chemical reaction occurred in SCR system includes：The injection of aqueous solution of urea, atomization, evaporation, The hydrolysis of urea and pyrolysis gas-phase chemical reaction and NOXIn catalyst surface and NH3The catalytic surface chemical reaction of generation.
From the foregoing, it will be observed that in SCR system, reaction gas of the ammonia as processing nitrogen oxides, SCR ammonia carrying capacity to tail gas at Reason effect has a great impact.The SCR ammonia carrying capacity will be adapted with the actual condition of engine, can be only achieved at ideal tail gas Manage effect.If SCR ammonia carrying capacity is too low, it is possible to the nitrogen oxides in exhaust emissions can be caused not to be fully processed, if SCR Ammonia carrying capacity is excessively high, and hair leads to the leakage of ammonia it is possible that can cause excessive ammonia that can escape from SCR media.Therefore, in order to reach To good vent gas treatment effect, electronic control unit (Electronic Control Unit, ECU) needs know SCR in real time Practical ammonia carrying capacity.
However, after engine is shut down, due to still remaining certain nitrogen oxides, and SCR is urged at this time in SCR babinets The temperature for changing device is higher, and remaining nitrogen oxides can lead to the damage of SCR ammonia carrying capacity with ammonia reaction of the absorption on SCR carriers Consumption.Simultaneously as after engine is shut down, a part of ammonia adsorbed on SCR carriers can be escaped in real time, and SCR ammonia is caused to carry The loss of amount.And amount of ammonia slip is related to SCR temperature, and SCR temperature is higher, and amount of ammonia slip is bigger, and SCR temperature is lower, and ammonia is escaped Ease amount is smaller.In this way, engine stopping process can lead to the loss of SCR ammonia carrying capacity.When restarting after engine shutdown, in order to ECU is made accurately to know the practical ammonia carrying capacity of SCR, needs the ammonia generated using engine stopping process loss to correct working as SCR Preceding ammonia carrying capacity.
The current SCR ammonia carrying capacity restarted after engine shutdown is modified in order to realize, needs accurately to obtain and start SCR ammonia loss in machine stopping process.
Based on this, the embodiment of the present application has fully considered the ammonia loss that absorption is influenced in stopping process on SCR carriers Factor, which not only includes downtime, further include remained in after processing is shut down nitrogen oxides in SCR babinets and SCR temperature.The nitrogen oxygen remained in because of processing in SCR babinets in engine stopping process can be got based on multiple factor Compound and the ammonia carrying capacity that consumes and with the relevant amount of ammonia slip of SCR temperature, ammonia carrying capacity and escape amount based on the consumption can The relatively accurately SCR ammonia loss in engine stopping process.
Fig. 1 is referred to, the method for SCR ammonia loss provided by the embodiments of the present application obtained in engine stopping process includes Following steps：
S101：Engine is obtained to shut down the SCR mean temperatures at moment, environment temperature and remain in the nitrogen in SCR catalyst The quality of oxide.
As the specific example of the application, thermometer in SCR catalyst can be installed in advance, pass through the thermometer Monitoring, ECU can obtain engine shut down the moment SCR mean temperatures.
In the embodiment of the present application, when environment temperature shuts down the moment for engine, the external environment temperature residing for SCR catalyst Degree.
As the specific example of the application, ECU can directly acquire the matter for remaining in the nitrogen oxides in SCR catalyst Amount.In addition as another specific example of the application, the quality of the nitrogen oxides remained in SCR catalyst can pass through hair Motivation shuts down the exhaust gas mass flow at moment, and the concentration of nitrogen oxides and the volume estimation of SCR babinets in tail gas obtain.Such as This, is in order to estimate to obtain the quality for remaining in the nitrogen oxides in SCR catalyst,
ECU will obtain the exhaust gas mass flow that engine shuts down the moment, the concentration of nitrogen oxides and SCR casees in tail gas The volume of body；Then further according to the exhaust gas mass flow, the concentration of nitrogen oxides and the volume of SCR babinets in tail gas, Estimation remains in the quality of the nitrogen oxides in SCR.
Specifically, the nitrogen oxidation that the quality of the nitrogen oxides in SCR can be equal in exhaust gas mass flow, tail gas is remained in The product of the concentration of object and the volume of SCR babinets.
S102：According to the SCR mean temperatures and environment temperature, SCR temperature attenuation curve is obtained.
It is to be appreciated that SCR temperature attenuation curve changes with time trend for representing SCR temperature.It as an example, should SCR temperature attenuation curve can be as shown in Figure 2.
Therefore, the SCR temperature attenuation curve, it is not only related with the initial temperature of SCR, it is also related with ambient temperature, Ambient temperature is lower, and SCR temperature attenuation is faster, and ambient temperature is higher, and SCR temperature attenuation is slower.So in this Shen It please need to shut down SCR mean temperatures and the environment temperature at moment according to engine bent to obtain SCR temperature attenuation in embodiment Line.
As the specific embodiment of the application, rule of thumb, the average temperature of multiple SCR often occurred can be demarcated in advance Degree and engine often in multiple environment temperatures under SCR temperature variation tendency, obtain what SCR temperature changed over time MAP chart table.As an example, the MAP chart table can be as shown in Figure 3.Be shown in FIG. 34 SCR mean temperatures (With) and 4 environment temperatures (With) under SCR temperature at any time Variation tendency, i.e. SCR temperature attenuation curve S1To S4。
In this specific embodiment, the MAP chart table that can be in advance demarcated according to SCR mean temperatures and environment temperature lookup, SCR temperature attenuation curve corresponding with SCR mean temperatures and environment temperature is found out from the MAP chart table.As an example it is assumed that The SCR mean temperatures got areEnvironment temperature isThen obtained according to the SCR mean temperatures and environment temperature The SCR temperature attenuation curve arrived is curve S1.
As another specific example of the application, SCR temperature model can also be constructed in advance, in the SCR temperature model Parameter include：Engine shuts down the SCR mean temperatures and environment temperature at moment.In this way, the SCR temperature built in advance according to this Model can get SCR temperature attenuation curve.Because the SCR temperature model constructed is considered as a mathematical formulae, therefore, It, can be by SCR temperature model that this is constructed no matter the SCR mean temperatures and the numerical value of environment temperature that get are how many Get corresponding SCR temperature attenuation curve.
S103：According to being handled the Mass Calculation of the SCR temperature attenuation curve and the nitrogen oxides remained in SCR The ammonia carrying capacity that the nitrogen oxides remained in SCR is consumed；According to SCR temperature attenuation curve and downtime, calculating is started The amount of ammonia slip of machine stopping process.
Because the chemical reaction in SCR is related to the temperature in SCR, therefore, it is necessary to according to SCR temperature attenuation curve The actual temperature of SCR and the Mass Calculation processing of the nitrogen oxides that remains in SCR described in remain in the nitrogen oxides in SCR The ammonia carrying capacity consumed.
In addition, after engine is shut down, a part of ammonia adsorbed on SCR carriers can be escaped in real time, and SCR ammonia is caused to carry The loss of amount.And amount of ammonia slip is related to SCR temperature, and SCR temperature is higher, and amount of ammonia slip is bigger, and SCR temperature is lower, and ammonia is escaped Ease amount is smaller.Therefore, for the SCR ammonia consumption being accurately obtained in engine stopping process, it is also necessary to be decayed according to SCR temperature Curve and downtime calculate the amount of ammonia slip of engine stopping process.
It is to be appreciated that in the embodiment of the present application, when engine is shut down, ECU, which can be recorded, shuts down the moment, in engine When being again started up after shutdown, at the time of recording when being again started up, engine is determined according to the time difference at two moment Downtime.
S104：The ammonia carrying capacity of the consumption is added with amount of ammonia slip, obtained adduction is in engine stopping process SCR ammonia is lost.
One above for the method for the SCR ammonia loss in acquisition engine stopping process provided by the embodiments of the present application is specific Realization method.In the specific implementation, the ammonia loss that absorption is influenced in stopping process on SCR carriers has been fully considered Factor, which not only includes downtime, further include remained in after processing is shut down nitrogen oxides in SCR babinets and SCR temperature.The nitrogen oxygen remained in because of processing in SCR babinets in engine stopping process can be got based on multiple factor Compound and occur in real time in the ammonia carrying capacity and stopping process that consume, with the relevant amount of ammonia slip of SCR temperature, based on the consumption Ammonia carrying capacity and escape amount can relatively accurately in engine stopping process the loss of SCR ammonia.
Further, it is lost based on the accurate SCR ammonia, can cause the ammonia carrying capacity and SCR by SCR physical model calculatings The ammonia carrying capacity actually adsorbed in carrier is consistent, and then can reduce adaptive and NH_3 leakage detection function triggering frequency.
In addition, in order to enable ECU is accurately obtained the practical ammonia carrying capacity in SCR, another specific reality as the application Existing mode, after S104, can also include the following steps：
When being again started up after engine shutdown, SCR ammonia loss corrections SCR's in the engine stopping process Current ammonia carrying capacity.
It is to be appreciated that when being again started up after engine shutdown, ECU can also start simultaneously, at this point, the SCR that ECU is detected Corresponding SCR ammonia carrying capacity when interior ammonia carrying capacity is shut down for last time engine.However, in engine stopping process, the ammonia in SCR There is loss in carrying capacity, therefore, in order to enable ECU is accurately obtained the practical ammonia in SCR when being again started up after engine is shut down Carrying capacity needs the current ammonia carrying capacity of the SCR ammonia loss corrections SCR in engine stopping process.SCR ammonia after amendment carries It measures SCR ammonia carrying capacity when being shut down for last time engine and subtracts caused ammonia loss in engine stopping process.
Because of the ammonia loss that can be accurately obtained in the embodiment of the present application in engine stopping process, therefore, it is based on The accurate ammonia loss, current ammonia carrying capacity can accurately correct SCR, so that ECU is accurately obtained the reality of SCR Border ammonia carrying capacity.
Specific reality for the method for the SCR ammonia loss in acquisition engine stopping process provided by the embodiments of the present application above Existing mode.Based on the specific implementation, the embodiment of the present application additionally provides a kind of electronic control unit.
Fig. 4 is referred to, electronic control unit provided by the embodiments of the present application includes：
First acquisition module 41 is shut down the SCR mean temperatures at moment, environment temperature and is remained in for obtaining engine The quality of nitrogen oxides in SCR；
Second acquisition module 42, for according to the SCR mean temperatures and environment temperature, obtaining SCR temperature attenuation curve；
First computing module 43, for according to the SCR temperature attenuation curve and remaining in SCR
Second computing module 44, for according to SCR temperature attenuation curve and downtime, calculating engine stopping process Amount of ammonia slip；
Module 45 is summed it up, the ammonia carrying capacity of the consumption is added with amount of ammonia slip, obtained adduction was shut down for engine SCR ammonia loss in journey.
As the alternative embodiment of the application, after ECU is enabled to be accurately obtained engine shutdown The practical ammonia carrying capacity of SCR when being again started up, electronic control unit described above can also include：
Correcting module 46, for when being again started up after engine is shut down, according to the SCR in the engine stopping process The current ammonia carrying capacity of ammonia loss correction SCR.
As the specific example of the application, trend is changed over time in order to relatively accurately get SCR temperature, second Acquisition module 42 can be specifically used for：MAP chart table is searched according to SCR mean temperatures and environment temperature, to obtain the temperature of SCR temperature Attenuation curve is spent, calibration obtains the MAP chart table in advance according to different SCR temperature and environment temperature.
As another specific example of the application, ensure that getting SCR temperature changes over time trend, second Acquisition module 42 can also be specifically used for according to the SCR temperature model built in advance, obtain SCR temperature attenuation curve.
As the another specific example of the application, in order to be accurately obtained the quality for remaining in the nitrogen oxides in SCR, First computing module 43 can specifically include：
Acquisition submodule, for obtaining the exhaust gas mass flow that engine shuts down the moment, nitrogen oxides in tail gas it is dense The volume of degree and SCR babinets；
Estimate submodule, for according to the exhaust gas mass flow, the concentration of nitrogen oxides and SCR babinets in tail gas Volume, estimation remains in the quality of nitrogen oxides in SCR.
It these are only embodiments herein, be not limited to the application.To those skilled in the art, The application can have various modifications and variations.All any modifications made within spirit herein and principle, equivalent replacement, Improve etc., it should be included within the scope of claims hereof.

Claims (10)

  1. A kind of 1. method of SCR ammonia loss obtained in engine stopping process, which is characterized in that including：
    Obtain SCR mean temperatures, environment temperature and the quality for remaining in the nitrogen oxides in SCR that engine shuts down the moment；
    According to the SCR mean temperatures and environment temperature, SCR temperature attenuation curve is obtained；
    SCR is remained according to the processing of the Mass Calculation of the SCR temperature attenuation curve and the nitrogen oxides remained in SCR The ammonia carrying capacity that interior nitrogen oxides is consumed；According to SCR temperature attenuation curve and downtime, engine stopping process is calculated Amount of ammonia slip；
    The ammonia carrying capacity of the consumption is added with amount of ammonia slip, obtained adduction is the SCR ammonia loss in engine stopping process.
  2. 2. according to the method described in claim 1, it is characterized in that, described according to the SCR mean temperatures and environment temperature, obtain SCR temperature attenuation curve is taken, is specifically included：
    MAP chart table is searched according to the SCR mean temperatures and environment temperature, to obtain temperature damping's curve of the SCR temperature, According to different SCR temperature and environment temperature, calibration obtains the MAP chart table in advance.
  3. 3. according to the method described in claim 1, it is characterized in that, described according to the SCR mean temperatures and environment temperature, obtain SCR temperature attenuation curve is taken, is specifically included：
    According to the SCR temperature model built in advance, SCR temperature attenuation curve is obtained.
  4. 4. according to the method described in claim 1, it is characterized in that, acquisition remains in the quality of the nitrogen oxides in SCR, specifically Including：
    The exhaust gas mass flow that engine shuts down the moment is obtained, the concentration of nitrogen oxides and the volume of SCR babinets in tail gas；
    According to the exhaust gas mass flow, the concentration of nitrogen oxides and the volume of SCR babinets, estimation in tail gas remain in The quality of nitrogen oxides in SCR.
  5. It is 5. according to the method described in claim 1, it is characterized in that, described by the ammonia carrying capacity of the consumption and amount of ammonia slip phase Add, after obtained adduction is the SCR ammonia loss in engine stopping process, further include：
    When being again started up after engine shutdown, SCR ammonia loss corrections SCR's in the engine stopping process is current Ammonia carrying capacity.
  6. 6. a kind of electronic control unit, which is characterized in that including：
    First acquisition module is shut down the SCR mean temperatures at moment, environment temperature and is remained in SCR for obtaining engine The quality of nitrogen oxides；
    Second acquisition module, for according to the SCR mean temperatures and environment temperature, obtaining SCR temperature attenuation curve；
    First computing module, for according to the SCR temperature attenuation curve and remaining in SCR
    Second computing module, for according to SCR temperature attenuation curve and downtime, the ammonia for calculating engine stopping process to be escaped Ease amount；
    Module is summed it up, the ammonia carrying capacity of the consumption is added with amount of ammonia slip, obtained adduction is in engine stopping process SCR ammonia is lost.
  7. 7. electronic control unit according to claim 6, which is characterized in that second acquisition module is specifically used for：
    MAP chart table is searched according to the SCR mean temperatures and environment temperature, to obtain temperature damping's curve of the SCR temperature, According to different SCR temperature and environment temperature, calibration obtains the MAP chart table in advance.
  8. 8. electronic control unit according to claim 6, which is characterized in that second acquisition module is specifically used for：
    According to the SCR temperature model built in advance, SCR temperature attenuation curve is obtained.
  9. 9. electronic control unit according to claim 6, which is characterized in that first computing module specifically includes：
    Acquisition submodule, for obtaining the exhaust gas mass flow that engine shuts down the moment, the concentration of the nitrogen oxides in tail gas with And the volume of SCR babinets；
    Estimate submodule, for according to the exhaust gas mass flow, the concentration of nitrogen oxides and the body of SCR babinets in tail gas Product, estimation remain in the quality of the nitrogen oxides in SCR.
  10. 10. electronic control unit according to claim 6, which is characterized in that the electronic control unit further includes：
    Correcting module, for when being again started up after engine is shut down, the SCR ammonia in the engine stopping process to be lost Correct the current ammonia carrying capacity of SCR.
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101149007A (en) * 2006-09-18 2008-03-26 福特环球技术公司 A method of managing ammonia vapour when engine in stop state
EP2256311A1 (en) * 2008-02-22 2010-12-01 Toyota Jidosha Kabushiki Kaisha Exhaust gas purifier for internal-combustion engine
US20120023906A1 (en) * 2010-03-11 2012-02-02 Aleksey Yezerets System and apparatus for enhancing exhaust aftertreatment startup emissions control
CN103061854A (en) * 2011-10-24 2013-04-24 福特环球技术公司 Method for controlling an injection device for feeding an ammonia-releasing reducing agent into an exhaust-gas purification system of an internal combustion engine
US20140039781A1 (en) * 2012-08-02 2014-02-06 Ford Global Technologies, Llc Nox control during engine idle-stop operations
EP2754871A1 (en) * 2013-01-15 2014-07-16 Ford Global Technologies, LLC Method and device for controlling the operation of an exhaust aftertreatment system in a vehicle
CN104314650A (en) * 2014-07-29 2015-01-28 潍柴动力股份有限公司 SCR (selective catalytic reduction) feed-forward control method and device
CN104632334A (en) * 2013-11-13 2015-05-20 福特环球技术公司 Method and system for reductant injector degradation

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101149007A (en) * 2006-09-18 2008-03-26 福特环球技术公司 A method of managing ammonia vapour when engine in stop state
EP2256311A1 (en) * 2008-02-22 2010-12-01 Toyota Jidosha Kabushiki Kaisha Exhaust gas purifier for internal-combustion engine
US20120023906A1 (en) * 2010-03-11 2012-02-02 Aleksey Yezerets System and apparatus for enhancing exhaust aftertreatment startup emissions control
CN103061854A (en) * 2011-10-24 2013-04-24 福特环球技术公司 Method for controlling an injection device for feeding an ammonia-releasing reducing agent into an exhaust-gas purification system of an internal combustion engine
US20140039781A1 (en) * 2012-08-02 2014-02-06 Ford Global Technologies, Llc Nox control during engine idle-stop operations
EP2754871A1 (en) * 2013-01-15 2014-07-16 Ford Global Technologies, LLC Method and device for controlling the operation of an exhaust aftertreatment system in a vehicle
CN104632334A (en) * 2013-11-13 2015-05-20 福特环球技术公司 Method and system for reductant injector degradation
CN104314650A (en) * 2014-07-29 2015-01-28 潍柴动力股份有限公司 SCR (selective catalytic reduction) feed-forward control method and device

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
胡杰等: "柴油机Urea-SCR催化器储氨量计算", 《汽车技术》 *
龚金科等: "SCR反应中NH3的存储释放特性及影响因素的数值研究", 《湖南大学学报（自然科学版）》 *

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