CN110094249B - A kind of ammonia leakage detection method and device - Google Patents

A kind of ammonia leakage detection method and device Download PDF

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Publication number
CN110094249B
CN110094249B CN201910572182.2A CN201910572182A CN110094249B CN 110094249 B CN110094249 B CN 110094249B CN 201910572182 A CN201910572182 A CN 201910572182A CN 110094249 B CN110094249 B CN 110094249B
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concentration
downstream
change
upstream
rate
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CN110094249A (en
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张勇
战强
李钊
房瑞雪
王明明
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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]
    • 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
    • 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
    • F02D41/146—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 an NOx content or concentration
    • F02D41/1461—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 an NOx content or concentration of the exhaust gases emitted by the engine
    • 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
    • F02D41/146—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 an NOx content or concentration
    • F02D41/1463—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 an NOx content or concentration of the exhaust gases downstream of exhaust gas treatment apparatus
    • 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
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • 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
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Abstract

Ammonia leakage detection method and device provided by the invention are applied to automobile technical field, and this method is based on the first NO being arranged in after-treatment systemxSensor and the 2nd NOxSensor is realized, the upstream NO of after-treatment system is obtainedxGas concentration and downstream NOxGas concentration, and according to upstream NOxGas concentration calculates to obtain upstream NOxConcentration rate of change, according to downstream NOxGas concentration calculates to obtain downstream NOxConcentration rate of change, if upstream NOxConcentration rate of change is greater than the first scheduled rate threshold value, downstream NOxConcentration rate of change, which is less than, is based on upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and downstream NOxGas concentration is greater than preset concentration threshold value, then determines that ammonia leakage occurs for after-treatment system.Ammonia leakage detection method and device provided by the invention can be not provided with NH3In the case where sensor, realizes the detection of ammonia leakage, be conducive to Product Cost Control.

Description

A kind of ammonia leakage detection method and device
Technical field
The invention belongs to automobile technical field more particularly to a kind of ammonia leakage detection method and device.
Background technique
SCR(Selective Catalytic Reduction, selective oxidation reduction) it is in diesel engine post-processing system Important component, in the SCR course of work, by urea injection system by preset urea nozzle spray urea liquid, Urea liquid can discharge NH when hydrolyzing3(ammonia) utilizes NH under the effect of the catalyst3By the NO in engine exhaustx(nitrogen oxygen The general name of compound) it is converted into N2, and then avoid NOxGaseous contamination atmosphere.
However, in practical applications, it is possible that NH3After flowing through SCR, not whole and NOxGas reacts, and It is that there are part NH3As engine exhaust enters in atmosphere, i.e. generation NH3Leakage, causes the secondary pollution to atmosphere.
In the prior art, a NH is often set in after-treatment system3Sensor, according to NH3The measured value of sensor judges Whether NH is occurred3Leakage, and NH is set3Sensor obviously will cause the increase of production cost.
Summary of the invention
In view of this, not increasing production the purpose of the present invention is to provide a kind of ammonia leakage detection method and device Under the premise of cost, accurately detect whether that NH occurs3Leakage, concrete scheme are as follows:
In a first aspect, the present invention provides a kind of ammonia leakage detection method, it is applied to include the first NOxSensor and second NOxThe after-treatment system of sensor, wherein the first NOxSensor is set to the after-treatment system upstream, and described second NOxSensor is set to the after-treatment system downstream, which comprises
Open the first NOxSensor and the 2nd NOxSensor, and obtain the upstream NO of the after-treatment systemx Gas concentration and downstream NOxGas concentration；
According to the upstream NOxGas concentration calculates to obtain upstream NOxConcentration rate of change；
According to the downstream NOxGas concentration calculates to obtain downstream NOxConcentration rate of change；
If the upstream NOxConcentration rate of change is greater than the first scheduled rate threshold value, the downstream NOxConcentration rate of change Less than based on the upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and the downstream NOxGas concentration is big In preset concentration threshold value, determine that ammonia leakage occurs for the after-treatment system.
Optionally, ammonia leakage detection method provided by first aspect present invention, further includes:
If the upstream NOx concentration rate of change is not more than the first scheduled rate threshold value, alternatively, the downstream NOx Concentration rate of change is not less than the second scheduled rate threshold value, or, the downstream NOx gas concentration is no more than described pre- If concentration threshold, determine that ammonia leakage does not occur for the after-treatment system.
Optionally, in the case where determining that ammonia leakage occurs for the after-treatment system, optionally, first aspect present invention Provided ammonia leakage detection method, further includes:
It controls urea nozzle and reduces urea liquid the amount of injection, until determining that ammonia leakage does not occur for the after-treatment system.
Optionally, the control urea nozzle reduces urea liquid the amount of injection, comprising:
It adjusts preset ammonia and stores up setting value to minimum value；
Obtain current ammonia storage actual value；
According to the current ammonia storage actual value and the minimum value, the amount of injection of urea nozzle is reduced.
Optionally, the ammonia leakage detection method that any one of first aspect present invention provides, the second scheduled rate threshold The upstream NOx concentration rate of change that value is N times, wherein N is greater than zero, and N is less than 1.
Optionally, the ammonia leakage detection method that any one of first aspect present invention provides, it is described to open the first NOx Sensor and second NOx sensor, comprising:
Obtain engine exhaust temperature；
If the duration that the engine exhaust temperature is greater than preset temperature threshold reaches preset time threshold, institute is opened State the first NOx sensor and second NOx sensor.
Second aspect, the present invention provide a kind of ammonia leakage detection device, comprising:
Acquiring unit for opening first NOx sensor and second NOx sensor, and obtains the rear place The upstream NOx gas concentration and downstream NOx gas concentration of reason system；
First computing unit, for according to the upstream NOxGas concentration calculates to obtain upstream NOxConcentration rate of change；
Second computing unit, for according to the downstream NOxGas concentration calculates to obtain downstream NOxConcentration rate of change；
First judging unit, if being used for the upstream NOxConcentration rate of change be greater than the first scheduled rate threshold value, it is described under Swim NOxConcentration rate of change, which is less than, is based on the upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and it is described Downstream NOxGas concentration is greater than preset concentration threshold value, determines that ammonia leakage occurs for the after-treatment system.
Optionally, the ammonia leakage detection device that second aspect of the present invention provides, further includes:
Second judging unit, if being used for the upstream NOxConcentration rate of change is not more than the first scheduled rate threshold value, Alternatively, the downstream NOxConcentration rate of change is not less than the second scheduled rate threshold value, or, the downstream NOxGas Concentration is not more than the preset concentration threshold value, determines that ammonia leakage does not occur for the after-treatment system.
Optionally, the ammonia leakage detection device that second aspect of the present invention provides, further includes:
Control unit reduces urea liquid the amount of injection for controlling urea nozzle, until determining the after-treatment system not Ammonia leakage occurs.
Optionally, described control unit specifically includes when reducing urea liquid the amount of injection for controlling urea nozzle:
It adjusts preset ammonia and stores up setting value to minimum value；
Obtain current ammonia storage actual value；
According to the current ammonia storage actual value and the minimum value, the amount of injection of urea nozzle is reduced.
Based on the above-mentioned technical proposal, ammonia leakage detection method and device provided by the invention, detection process eliminate the reliance on In NH3Sensor, but based on the first NO being arranged in existing after-treatment systemxSensor and the 2nd NOxSensor realization, First NOxSensor and the 2nd NOxAfter sensor is opened, the upstream NO of after-treatment system is obtainedxGas concentration and downstream NOxGas Bulk concentration, and according to upstream NOxGas concentration calculates to obtain upstream NOxConcentration rate of change, according to downstream NOxGas concentration meter Calculation obtains downstream NOxConcentration rate of change, if upstream NOxConcentration rate of change is greater than the first scheduled rate threshold value, downstream NOx Concentration rate of change, which is less than, is based on upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and downstream NOxGas is dense Degree is greater than preset concentration threshold value, then determines that ammonia leakage occurs for after-treatment system.Ammonia leakage detection method provided by the invention And device, NH can be not provided with3In the case where sensor, realizes the detection of ammonia leakage, be conducive to Product Cost Control.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is the present invention Some embodiments for those of ordinary skill in the art without creative efforts, can also basis These attached drawings obtain other attached drawings.
Fig. 1 is a kind of flow chart for ammonia leakage detection method that the present patent application embodiment provides；
Fig. 2 is the structural representation of the after-treatment system of the ammonia leakage detection method provided using the present patent application embodiment Figure；
Fig. 3 is a kind of structural block diagram for ammonia leakage detection device that the present patent application embodiment provides；
Fig. 4 is the structural block diagram for another ammonia leakage detection device that the present patent application embodiment provides；
Fig. 5 is the structural block diagram for another ammonia leakage detection device that the present patent application embodiment provides.
Specific embodiment
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention In attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is A part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art Every other embodiment obtained without making creative work, shall fall within the protection scope of the present invention.
NOxThe cross-sensitivity of sensor refers to due to sensor itself measuring principle, NOxSensor can be by tail NH in gas3It is identified as NOxGas, and then lead to NOxThe measured value of gas is higher.In conjunction with NOxThe cross-sensitivity of sensor, Inventor studies discovery: if NH occurs for after-treatment system3Leakage, in the motor exhaust by SCR processing, the downstream SCR NOxConcentration rate of change is very slow, and downstream NOxGas concentration measurement is larger；And NH does not occur in after-treatment system3Leakage In the case of, the downstream SCR NOxConcentration rate of change and upstream NOxThe variation tendency of concentration rate of change is essentially identical.
Based on above-mentioned premise, the present patent application embodiment provides a kind of ammonia leakage detection method, is this referring to Fig. 1, Fig. 1 Inventive embodiments provide ammonia leakage detection method flow chart, this method can be applied to vehicle setting entire car controller or Car running computer etc. has the controller of data-handling capacity, it is clear that the server that network side also can be selected in some cases is real It is existing；Referring to Fig.1, ammonia leakage detection method provided in an embodiment of the present invention may include:
Step S100, the first NO is openedxSensor and the 2nd NOxSensor, and obtain the upstream NO of after-treatment systemxGas Bulk concentration and downstream NOxGas concentration.
Referring to fig. 2, Fig. 2 is the after-treatment system of the ammonia leakage detection method provided using the present patent application embodiment Structural schematic diagram, the after-treatment system include the first NOx sensor P1 and the second NOx sensor P2, wherein the first NOx sensing Device P1 is set to after-treatment system upstream, the 2nd NOxSensor P2 is set to after-treatment system downstream, and controller is respectively with first NOx sensor P1 and the second NOx sensor P2 is connected, and realizes to NOxThe control that sensor opens and closes, and, pass through NOx Sensor obtains the NOx gas concentration of after-treatment system upstream and the NOx gas concentration in after-treatment system downstream.
It should be noted that in embodiment illustrated in fig. 2 the first NOx sensor P1 and the second NOx sensor P2 installation position A kind of only example is set, needed according to measurement and the problems such as vehicle space, NOx sensor can also be arranged in post-processing Other suitable locations in system, any available NOx gas concentration, and accurately reflect the position of NOx gas concentration rate of change It is all optional for setting, and equally belongs to the range of the present patent application protection.
It is well known, ceramic measuring mechanism is provided in NOx sensor, if the ceramic measuring mechanism in NOx sensor NOx sensor is opened in the case where having condensed water in surface, will cause NOx sensor damage.Therefore, optionally, using the present invention The ammonia leakage detection method that embodiment provides, before opening NOx sensor, it is necessary first to engine exhaust temperature is obtained, And start timing when engine exhaust temperature is greater than preset temperature threshold, add up engine exhaust temperature and is greater than preset temperature threshold The duration of value can be determined that ceramic measuring mechanism table in NOx sensor if the duration reaches preset time threshold The condensed water in face has evaporated, and can open NOx sensor.
Opening the first NOxSensor and the 2nd NOxAfter sensor, the first NO can be passed throughxSensor obtains post-processing The upstream NO of systemxGas concentration passes through the 2nd NOxThe downstream NO of sensor acquisition after-treatment systemxGas concentration.
Step S110, according to upstream NOxGas concentration calculates to obtain upstream NOxConcentration rate of change.
Obtain upstream NOxIt, can be according to upstream NO after gas concentrationxGas concentration calculates to obtain upstream NOxConcentration variation Rate.
Optionally, the embodiment of the present invention provides a kind of calculating NOxThe calculation formula of concentration rate of change, specifically, seeing public affairs Shown in formula (1).
(1)
Wherein,Indicate upstream NOxConcentration rate of change；
It indicates to filter preceding upstream NOxGas concentration；
Indicate upstream NO after filteringxGas concentration.
It should be noted that the present embodiment, which is merely exemplary, provides a kind of method for calculating concentration rate of change, not Under the premise of the present patent application core concept range, other methods that can calculate gas concentration rate of change are equally can Choosing, also belong to the range of the present patent application protection.
Step S120, according to downstream NOxGas concentration calculates to obtain downstream NOxConcentration rate of change.
Optionally, as previously mentioned, downstream NOxThe calculation formula of concentration rate of change can be as shown in Equation (2).
(2)
Wherein,Indicate downstream NOxConcentration rate of change；
It indicates to filter preceding downstream NOxGas concentration；
Indicate downstream NO after filteringxGas concentration.
It should be noted that for upstream NOxConcentration rate of change and downstream NOxThe calculating of concentration rate of change is not tight Lattice limit sequencing, can be as described in the embodiments of the present invention, first calculate upstream NOxConcentration rate of change, then calculates again Downstream NOxConcentration rate of change；It is of course also possible to first calculate downstream NOxThen concentration rate of change calculates upstream NO againxConcentration Rate of change；It is of course also possible to calculate upstream NO simultaneouslyxConcentration rate of change and downstream NOxConcentration rate of change, these calculating Sequence is all optional.
It should be noted NOxThe value that sensor measurement obtains is exactly NO before filteringxGas concentration；Before obtaining filtering NOxAfter gas concentration, filtering cycle and dispatching cycle can be set according to filtering algorithm in the prior art, in turn NO after being filteredxGas concentration.
Step S130 judges whether to meet decision condition: upstream NOxConcentration rate of change is greater than the first scheduled rate threshold Value, downstream NOxConcentration rate of change, which is less than, is based on upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and downstream NOxGas concentration is greater than preset concentration threshold value, if it is satisfied, step S140 is executed, if conditions are not met, executing step S150.
After-treatment system upstream NO is being calculatedxConcentration rate of change and downstream NOxAfter concentration rate of change According to the size relation of calculated value and measured value, determine whether after-treatment system occurs ammonia leakage.
Specifically, in upstream NOxIn the case that concentration rate of change is greater than the first scheduled rate threshold value, if downstream NOxIt is dense Rate of change is spent to be less than based on upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and downstream NOxGas concentration Greater than preset concentration threshold value, then step S140 can be executed, determine that after-treatment system has occurred and that NH3Leakage.
Optionally, as previously mentioned, whether NH occurs in after-treatment system3Leakage, to upstream NOxConcentration rate of change is under Swim NOxConcentration rate of change has direct influence, therefore, be based on upstream NOxSecond scheduled rate of concentration rate of change setting Threshold value is specifically as follows: N times of upstream NOxConcentration rate of change, wherein N is greater than zero, and N is less than 1.
It optionally, can be true by the way of experimental test for specific after-treatment system for the specific value of N It is fixed, it is of course also possible to rule of thumb preset specified.Likewise, for the first scheduled rate threshold value and preset concentration threshold value It chooses, can also be given using test or rule of thumb, specific selection mode of the embodiment of the present application to aforementioned each parameter Without limitation.
Step S140 determines that ammonia leakage occurs for after-treatment system.
When meeting the decision condition that step S130 is provided, that is, it can determine that ammonia leakage occurs for after-treatment system.
Step S150 determines that ammonia leakage does not occur for after-treatment system.
When being unsatisfactory for decision condition that step S130 is provided, that is, it can determine that ammonia leakage does not occur for after-treatment system.
Specifically, if upstream NOxConcentration rate of change is not more than the first scheduled rate threshold value, alternatively, downstream NOxConcentration becomes Change rate and is not less than the second scheduled rate threshold value, or, downstream NOxGas concentration is not more than preset concentration threshold value, i.e., above-mentioned When three decision conditions are unsatisfactory for there are any one or more, that is, it can determine that ammonia leakage does not occur for the after-treatment system.
In conclusion ammonia leakage detection method provided in an embodiment of the present invention, depends in existing after-treatment system The first NO being setxSensor and the 2nd NOxSensor is realized, can be not provided with NH3In the case where sensor, realize The detection of ammonia leakage, is conducive to Product Cost Control.
Further, compared with the existing technology in acquire downstream NO merelyxGas concentration, according to downstream NOxGas concentration with The size relation of preset concentration threshold value judges whether that the mode that ammonia leakage occurs is compared, and ammonia provided in an embodiment of the present invention is let out Leak detection method, it is possible to prevente effectively from NOxInfluence of the sensor decussation sensitivity to measurement result avoids that ammonia is already occurring It is still to spray urea in the case where leakage more, cause ammonia leakage persistently to increase, increases the risk of urea crystals.
Optionally, in the case where determining that ammonia leakage occurs for after-treatment system, method provided by the embodiment of the present invention It can also include: that control urea nozzle reduces urea liquid the amount of injection, until determining that ammonia leakage does not occur for after-treatment system.
Specifically, determine after-treatment system occur ammonia leakage in the case where, first adjusting preset ammonia store up setting value to Minimum value, and further obtain current ammonia storage actual value, according to current ammonia store up actual value and the minimum value size relation and Difference controls the amount of injection of urea.Since preset ammonia storage setting value is adjusted to minimum value, current ammonia storage is practical Value is commonly greater than the minimum value, at this point, SCR control model will assert the NH in current SCR system3It is enough, it will reduce The amount of injection of urea nozzle reduces NH in after-treatment system3, to avoid NH3Leakage.
Ammonia leakage detection device provided in an embodiment of the present invention is introduced below, ammonia leakage inspection described below Surveying device may be considered the ammonia leakage detection method that embodiment provides to realize the present invention, and setting is needed in central equipment Functional module framework；Be described below content can with above it is cross-referenced.
Fig. 3 is a kind of structural block diagram for ammonia leakage detection device that the present patent application embodiment provides, should referring to Fig. 3 Device may include:
Acquiring unit 10, for opening the first NOxSensor and the 2nd NOxSensor, and obtain the rear place The upstream NO of reason systemxGas concentration and downstream NOxGas concentration；
First computing unit 20, for according to the upstream NOxGas concentration calculates to obtain upstream NOxConcentration rate of change；
Second computing unit 30, for according to the downstream NOxGas concentration calculates to obtain downstream NOxConcentration rate of change；
First judging unit 40, if being used for the upstream NOxConcentration rate of change is greater than the first scheduled rate threshold value, described Downstream NOxConcentration rate of change, which is less than, is based on the upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and institute State downstream NOxGas concentration is greater than preset concentration threshold value, determines that ammonia leakage occurs for the after-treatment system.
Optionally, referring to fig. 4, Fig. 4 is the knot for another ammonia leakage detection device that the present patent application embodiment provides Structure block diagram on the basis of device embodiment shown in Fig. 3, can also include:
Second judging unit 50, if being used for the upstream NOxConcentration rate of change is not more than the first scheduled rate threshold Value, alternatively, the downstream NOxConcentration rate of change is not less than the second scheduled rate threshold value, or, the downstream NOxGas Bulk concentration is not more than the preset concentration threshold value, determines that ammonia leakage does not occur for the after-treatment system.
It optionally, is the knot for another ammonia leakage detection device that the present patent application embodiment provides referring to Fig. 5, Fig. 5 Structure block diagram, the device on the basis of the embodiment shown in fig. 4, can also include:
Control unit 60 reduces urea liquid the amount of injection for controlling urea nozzle, until determining the after-treatment system Ammonia leakage does not occur.
Optionally, described control unit 60 specifically include when reducing urea liquid the amount of injection for controlling urea nozzle:
It adjusts preset ammonia and stores up setting value to minimum value；
Obtain current ammonia storage actual value；
According to the current ammonia storage actual value and the minimum value, the amount of injection of urea nozzle is reduced.
Professional further appreciates that, unit described in conjunction with the examples disclosed in the embodiments of the present disclosure And algorithm steps, can be realized with electronic hardware, computer software, or a combination of the two, in order to clearly demonstrate hardware and The interchangeability of software generally describes each exemplary composition and step according to function in the above description.These Function is implemented in hardware or software actually, the specific application and design constraint depending on technical solution.Profession Technical staff can use different methods to achieve the described function each specific application, but this realization is not answered Think beyond the scope of this invention.
The step of method described in conjunction with the examples disclosed in this document or algorithm, can directly be held with hardware, processor The combination of capable software module or the two is implemented.Software module can be placed in random access memory (RAM), memory, read-only deposit Reservoir (ROM), electrically programmable ROM, electrically erasable ROM, register, hard disk, moveable magnetic disc, CD-ROM or technology In any other form of storage medium well known in field.
The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, as defined herein General Principle can be realized in other embodiments in the case where not departing from core of the invention thought or scope.Therefore, originally Invention is not intended to be limited to the embodiments shown herein, and is to fit to and the principles and novel features disclosed herein Consistent widest scope.

Claims (10)

1. a kind of ammonia leakage detection method, which is characterized in that be applied to include the first NOxSensor and the 2nd NOxSensor After-treatment system, wherein the first NOxSensor is set to the after-treatment system upstream, the 2nd NOxSensor is set It is placed in the after-treatment system downstream, which comprises
Open the first NOxSensor and the 2nd NOxSensor, and obtain the upstream NO of the after-treatment systemxGas Concentration and downstream NOxGas concentration；
According to the upstream NOxGas concentration calculates to obtain upstream NOxConcentration rate of change；
According to the downstream NOxGas concentration calculates to obtain downstream NOxConcentration rate of change；
If the upstream NOxConcentration rate of change is greater than the first scheduled rate threshold value, the downstream NOxConcentration rate of change is less than Based on the upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and the downstream NOxGas concentration is greater than pre- If concentration threshold, determine that ammonia leakage occurs for the after-treatment system.
2. ammonia leakage detection method according to claim 1, which is characterized in that the method also includes:
If the upstream NOx concentration rate of change is not more than the first scheduled rate threshold value, alternatively, the downstream NOx concentration Rate of change be not less than the second scheduled rate threshold value, or, the downstream NOx gas concentration no more than it is described preset it is dense Threshold value is spent, determines that ammonia leakage does not occur for the after-treatment system.
3. ammonia leakage detection method according to claim 2, which is characterized in that determining the after-treatment system generation In the case where ammonia leakage, the method also includes:
It controls urea nozzle and reduces urea liquid the amount of injection, until determining that ammonia leakage does not occur for the after-treatment system.
4. ammonia leakage detection method according to claim 3, which is characterized in that the control urea nozzle reduces urea Solution the amount of injection, comprising:
It adjusts preset ammonia and stores up setting value to minimum value；
Obtain current ammonia storage actual value；
According to the current ammonia storage actual value and the minimum value, the amount of injection of urea nozzle is reduced.
5. ammonia leakage detection method according to claim 1-4, which is characterized in that second scheduled rate The upstream NOx concentration rate of change that threshold value is N times, wherein N is greater than zero, and N is less than 1.
6. ammonia leakage detection method according to claim 1-4, which is characterized in that described to open described first NOx sensor and second NOx sensor, comprising:
Obtain engine exhaust temperature；
If the duration that the engine exhaust temperature is greater than preset temperature threshold reaches preset time threshold, described the is opened One NOx sensor and second NOx sensor.
7. a kind of ammonia leakage detection device characterized by comprising
Acquiring unit for opening the first NOx sensor and the second NOx sensor, and obtains the upstream NOx gas of after-treatment system Bulk concentration and downstream NOx gas concentration；
First computing unit, for according to the upstream NOxGas concentration calculates to obtain upstream NOxConcentration rate of change；
Second computing unit, for according to the downstream NOxGas concentration calculates to obtain downstream NOxConcentration rate of change；
First judging unit, if being used for the upstream NOxConcentration rate of change is greater than the first scheduled rate threshold value, the downstream NOx Concentration rate of change, which is less than, is based on the upstream NOxSecond scheduled rate threshold value of concentration rate of change setting, and the downstream NOxGas concentration is greater than preset concentration threshold value, determines that ammonia leakage occurs for the after-treatment system.
8. ammonia leakage detection device according to claim 7, which is characterized in that further include:
Second judging unit, if being used for the upstream NOxConcentration rate of change is not more than the first scheduled rate threshold value, alternatively, The downstream NOxConcentration rate of change is not less than the second scheduled rate threshold value, or, the downstream NOxGas concentration is not Greater than the preset concentration threshold value, determine that ammonia leakage does not occur for the after-treatment system.
9. ammonia leakage detection device according to claim 7, which is characterized in that further include:
Control unit reduces urea liquid the amount of injection for controlling urea nozzle, until determining that the after-treatment system does not occur Ammonia leakage.
10. ammonia leakage detection device according to claim 9, which is characterized in that described control unit, for controlling urine When plain nozzle reduces urea liquid the amount of injection, specifically include:
It adjusts preset ammonia and stores up setting value to minimum value；
Obtain current ammonia storage actual value；
According to the current ammonia storage actual value and the minimum value, the amount of injection of urea nozzle is reduced.
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US20110083429A1 (en) * 2009-01-09 2011-04-14 Masaaki Sato Catalyst passing component determining apparatus and exhaust purification apparatus for internal combustion engine
US8769928B2 (en) * 2010-09-27 2014-07-08 Caterpillar Inc. Exhaust system having cross-sensitive sensor
US10329986B2 (en) * 2017-07-18 2019-06-25 Gm Global Technology Operations Llc. Model-based monitoring for selective catalytic reduction device in aftertreatment assembly

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