• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A method and a system for estimation of a soot load in a particle filter in an exhaust cleaning system, which estimation involves using a pressure drop across said particle filter in order to determine the soot load. Measurement of the pressure drop across the particle filter and therefore the estimation have to take place at a time when an exhaust mass flow of the exhaust cleaning system exceeds a flow threshold value, the particle filter is substantially free from water and a temperature of the particle filter exceeds a first threshold value. The result is a robust estimate of the soot load in the particle filter.
    公开号:SE1050891A1
    申请号:SE1050891
    申请日:2010-08-31
    公开日:2012-03-01
    发明作者:Carl-Johan Karlsson；Klas Telborn
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    lOFurthermore, finishing systems, alternatively or incombination with one or more catalysts, include otherscomponents, such as e.g. particulate filter. It also occursparticulate filters and catalysts integrated witheach other.
    During combustion engine combustion in the cylinders is formedsoot particles. Particulate filters are used to capture thesesoot particles, and works in such a way that the exhaust gas flow is conductedthrough a filter structure where soot particles are captured from itpassing the exhaust gas stream and stored in the particulate filter.
    The particulate filter is filled with soot as the vehicle is driven,and sooner or later the filter must be emptied of soot, whichusually accomplished by means of so-called regeneration.
    Regeneration means that the soot particles, which mainlyconsists of carbon particles, is converted to carbon dioxide and / orcarbon monoxide in one or more chemical processes, and essentiallyregeneration can take place in two different ways. On the one hand, regeneration canhappen through so-called oxygen (O2) -based regeneration, also called activeregeneration. During active regeneration, fuel is addedthe exhaust gases, which are intended to burn in oneoxidation catalyst arranged upstream of the particulate filter.
    During active regeneration, carbon is converted with the help of oxygen tocarbon dioxide and heat.
    This chemical reaction requires relatively highparticle filter temperatures to desired reaction rate(emptying speed) should occur at all.
    Instead of active regeneration, NO2-based regeneration,also called passive regeneration, is applied. When passiveregeneration nitric oxide and carbon monoxide are formed by a reactionbetween carbon and nitrogen dioxide. The advantage of passive regenerationis that desired reaction rates, and hence the ratelOl5with which the filter is emptied, can be achieved at significantly lowertemperatures.
    As described below, a differential pressure over is usedthe particulate filter, i.e. a pressure drop acrossthe particulate filter, to determine the soot load in the particulate filter.
    Based on this pressure drop, a regeneration is then determinedto be performed. However, the measurements of the differential pressure are overthe particulate filter suffered from a plurality of sources of error, whichmakes previously known estimates of the soot loadincorrect.
    This can lead to regeneration being performed at non-optimaltimes, which causes the vehicle to be driven unnecessarily highback pressure in the particulate filter, with increased fuel consumption asresults. Alternatively, regeneration leads to non-optimaltimes that regeneration is performed too often, whichalso causes increased fuel consumption.
    Summary of the inventionIt is an object of the present invention thatprovide a procedure for estimating a soot load ina particulate filter. This object is achieved by the abovemethod according to the characterizing part of claim 1.
    The purpose is also achieved by the above-mentioned system according to itcharacterizing part of claim 20. This object is also achievedof the above-mentioned computer program and the above-mentionedthe vehicle.
    The present invention provides a robust andreliable estimation of the soot load in the particulate filter, wherethe impact of the estimate on the accuracy of the donors used anddissolution, and the effect of condensed water inthe particle filter is minimized.lOl5The procedure ensures the reliability of the estimation ofsoot load by determining when estimating the soot loadto be performed. If this time is selected according to the inventiona lot of problems and sources of error which have been done before are avoidedknown estimates unreliable.
    By, according to various embodiments of the invention, seeto that the temperature of the particle filter has beenhigh enough for a sufficiently long period of time beforethe estimation of the soot load begins, it is ensured thatthe particulate filter then is substantially free of the water whichpossibly was in the particulate filter at the start of the vehicle.
    This avoids the back pressure caused by condensation water such aspossibly accumulated in the particulate filter after switching offthe vehicle is added to the back pressure from the soot load atthe estimate.
    By ensuring that the exhaust gas volume flow, when the estimation ofthe soot load is made, exceeds a sufficiently high setflow threshold, is ensured that the pressure drop sensorresolution is sufficient for the measured flow value forto provide good accuracy. In other words, the pressure drop is overthe particulate filter at these high flows large relative tothe accuracy of the sensor. This results in the signal fromthe sensor is only affected by faults which are relatively smallimpact on the estimate.
    By making sure that the temperature of the particulate filter beforethe soot load is estimated to exceed a firsttemperature threshold, which is higher than a temperature atwhich water in the exhaust gases can condense, problems are avoidedrelated to possible recondensation of water, sincesuch re-condensation can occur if the temperature is temporarysinks during operation of the vehicle.l0l5Overall, by the present invention, one more is obtainedaccurate estimation of the soot load, since the majority possiblesources of error are eliminated by an inventive choice of whenthe estimation shall be performed.
    Additional features of the present invention andbenefits thereof will be apparent from the following detaileddescription of exemplary embodiments and those attachedthe drawings.
    Brief description of the drawingsFig. 1a shows a driveline in a vehicle at whichthe present invention can be used to advantage.
    Fig. 1b shows an example control unit in a vehicle control system.
    Fig. 2 shows an example of a finishing system in onevehicle in which the present invention is advantageousCan be used.
    Fig. 3 shows differential pressure as a function of the volume flowthrough the particle filter for two different soot loads.
    Fig. 4 shows a flow chart for a method according tothe invention.
    Detailed description of preferred embodimentsFig. 1a schematically shows a heavy exemplary vehicle 100, such asa truck, bus or the like, according to aexemplary embodiment of the present invention. That in Fig. 1aschematically shown the vehicle 100 comprises a front pair of wheelslll, ll2 and a rear wheel pair with drive wheels ll3, ll4. The vehiclefurther comprising a powertrain with an internal combustion engine l10,which in a usual way, via one on the internal combustion engine101 output shaft 102, is connected to a gearbox 103,for example via a coupling l06.
    A shaft 107 emanating from the gearbox 103 drives the drive wheels113, 114 via a final gear 108, such as e.g. a usualdifferential, and drive shafts 104, 105 connected to saidfinal gear 108.
    The vehicle 100 further includes aafter-treatment system / exhaust purification system 200 for treatment(purification) of exhaust emissions from the internal combustion engine 101.
    The finishing system is shown in more detail in Fig. 2. The figureshows the internal combustion engine 101 of the vehicle 100, where they atthe combustion generated exhaust gases are led via a turbocharger220 (in turbo engines often drives it from combustionresulting exhaust gas a turbocharger which in turncompresses the incoming air to the cylinderscombustion). The function of the turbocharger is very well known,and is therefore not described in more detail here. The exhaust stream is then ledvia a tube 204 (indicated by arrows) to a particle filter202 via an oxidation catalyst (Diesel Oxidation Catalyst,DOC) 205.
    Furthermore, the finishing system includes a downstream rethe particulate filter 202 (Diesel Particulate Filter, DPF) arrangedSCR Catalyst 201 (Selective Catalytic Reduction). SCR-Catalysts use ammonia (NH3), or a compositionfrom which ammonia can be generated / formed, as an additive forreduction of the amount of nitrogen oxides (NOK).
    The particle filter 202 may alternatively be arranged downstreamThe SCR catalyst 201, although this may be smalleradvantageous when the present invention relates to so-calledpassive regeneration where the regeneration depends on thenitrogen oxides normally reduced by the SCR catalyst. According toan embodiment of the present invention comprisesthe finishing system does not have any SCRcatalyst.
    The oxidation catalyst DOC 205 has several functions, andutilizes the excess air that the diesel engine process generally hasgives rise to in the exhaust stream as a chemical reactor togetherwith a noble metal coating in the oxidation catalyst.
    The oxidation catalyst is normally used primarily for oxidationresidual hydrocarbons and carbon monoxide in the exhaust gas tocarbon dioxide and water.
    However, the oxidation catalyst can also oxidize a large proportion ofthe nitrogen monoxides (NO) present in the exhaust stream tonitrogen dioxide (NO 2). This nitrogen dioxide is then used in passiveregeneration according to the present invention. Even furtherreactions may occur in the oxidation catalyst.
    In the embodiment shown of the exhaust gas purification system, DOC205, DPF 202 and also the SCR catalyst 201 integrated in oneand the same exhaust gas purification unit 203. However, it should be understood that DOC205 and DPF 202 do not have to be integrated in one and the sameexhaust gas purification unit, but the units may be arranged elsewherewhere appropriate. For example, DOC 205 may bearranged closer to the internal combustion engine 101. Likewise, the SCRthe catalyst must be arranged separately from DPF 201 and / or DOC205.
    The exhaust purification system set shown in Fig. 2 is commonoccurring in heavy vehicles, at least in jurisdictions therehigher emission requirements prevail, but as an alternative tothe oxidation catalyst may instead comprise the particulate filterprecious metal coatings so that those in the oxidation catalystexisting chemical processes instead occur inthe particulate filter, the exhaust gas purification system thus notincludes any DOC 205.l0l5As mentioned, soot particles are formed at the internal combustion engine 101combustion. These soot particles should not, and may in many casesnor, are released into the vehicle environment. Diesel particlesconsists of hydrocarbons, carbon (soot) and inorganic substances such assulfur and ash. As mentioned above, these soot particles are trappedtherefore up by the particle filter 202, which works in this waythat the exhaust stream is led through a filter structure theresoot particles are captured from the passing exhaust stream forto then be stored in the particle filter 202. Usingparticulate filter 202 can a very large proportion of the particlesseparated from the exhaust stream.
    As particles are separated from the exhaust stream with the helpof the particle filter 202, the separated ones thus accumulatethe particles in the particle filter 202, this over timefilled with soot. Depending on factors such as currentdriving conditions, the driver's driving style and vehicle load will onegreater or lesser amount of soot particles to be generated, whythis fulfillment happens more or less quickly, but when the filteris met to a certain level, the filter must be "emptied". Ifthe filter is met to too high a level can the vehicleperformance is affected, while also fire hazard, p.g.a.soot accumulation in combination with high temperatures, may occur.
    As above, emptying of particle filter 202 is performed by means ofregeneration where soot particles, carbon particles, in a chemicalprocess is converted to carbon dioxide and / or carbon monoxide. Overtime must thus the particle filter 202 by more or lessregular intervals are regenerated, and determination of appropriatetime for regeneration of the particle filter can e.g. performedby means of a control unit 208, which e.g. can performdetermination of appropriate time (s) at least in partby means of signals from a pressure sensor 209, which measuresdifferential pressure across the particulate filter. The morethe particle filter 202 fills up, the higher it comesthe pressure difference across the particle filter 202 to be.Also current temperatures before and / or afterthe oxidation catalyst 205 and / or before and / or afterthe particulate filter 202 may act in determiningregeneration time. These temperatures can e.g. determinedusing temperature sensors 210-212.
    Normally no regeneration measures are taken as long asthe fill level of the filter is less than a predetermined level.
    For example. the control system control of the filter regeneration can beso arranged that no action is taken as long as that of the filterdegree of filling e.g. falls below any appropriate degree of filling inrange 60-80%. The degree of filling of the filter can be estimated atany suitable way, e.g. using the differential pressureas above, where a certain pressure difference represents a certaindegree of filling.
    The control unit 208 also controls the estimation of soot load according topresent invention, which is described in more detail below.
    In general, steering systems in modern vehicles usually consist of onecommunication bus system consisting of one or morecommunication buses to connect a numberelectronic controllers (ECUs), or controllers, andvarious components located on the vehicle. One suchcontrol systems can comprise a large number of control units, andthe responsibility for a specific function can be divided into more thana control unit.
    For the sake of simplicity, in Fig. 2 only the control unit 208 is shown,but vehicles of the type shown often include a relativelarge number of control units, e.g. for engine control,gearbox, etc., which is well known to those skilled in the artthe technical field.
    The present invention can thus be implemented in the control unit208, but can also be fully or partially implemented in one orseveral other control units located at the vehicle.
    Controllers of the type shown are normally arranged to takereceiving sensor signals from different parts of the vehicle, e.g., such asshown in Fig. 2, said pressure sensor 209 and temperature sensors210-212, and also e.g. a motor control unit (not shown). Thecontrol unit-generated control signals are normally also dependentboth of signals from other control units and signals fromcomponents. For example, the control unit 208 may control thethe regeneration of the present invention depends oninformation received from the engine control unit, for example, andthe temperature / pressure sensors shown in Fig. 2.
    Control units of the type shown are usually also arrangedto emit control signals to various parts and components ofthe vehicle, in the present example for example tothe engine control unit to request / order control ofcombustion engine combustion as below.
    The control is often controlled by programmed instructions. Theseprogrammed instructions typically consist of onecomputer programs, which when executed on a computer orcontrol unit causes the computer / control unit to perform the desired operationcontrol, such as process steps of the present invention.
    The computer program is usually a computer program product 109stored on a digital storage medium 121 (see Figure 1b) such asfor example: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM(Electrically Erasable PROM), a hard disk drive, etc., in orin connection with the control unit, and which is executed bythe control unit. By following other computer program instructionscan thus the behavior of the vehicle in a specific situationäflpäSSäS.11An exemplary controller (controller 208) is shown schematically in FIG.1b, wherein the control unit 208 in turn may comprise acalculation unit 120, which may be substantially anysuitable type of processor or microcomputer, e.g. a circuit fordigital signal processing (Digital Signal Processor, DSP),or a circuit with a predetermined specific function(Application Specific Integrated Circuit, ASIC).
    The computing unit 120 is connected to a memory unit 121,which provides the computing unit 120 e.g. the storedprogram code 109 and / or the stored data computing device120 needed to be able to perform calculations.
    The calculation unit 120 is also arranged to store partial orend result of calculations in memory unit 121.
    Furthermore, the control unit 208 is provided with devices 122, 123,124, 125 for receiving and sending input and output, respectivelyoutput signals. These input and output signals can containwaveforms, pulses, or other attributes, which ofthe devices 122, 125 for receiving input signals candetected as information and can be converted into signals,which can be processed by the computing unit 120.
    These signals are then provided to the computing unit 120.
    The devices 123, 124 for transmitting output signals are providedto convert signals obtained from the computing unit 120 forcreation of output signals by e.g. modulate the signals,which can be transferred to other parts of the vehicle's steering systemand / or the component (s) for which the signals are intended.
    Each of the connections to the receiving devicesrespective transmission of input and output signals can be constitutedof one or more of a cable; a data bus, such as a CAN bus(Controller Area Network bus), and MOST bus (Media OrientatedSystems Transport), or any other bus configuration; orof a wireless connection.12According to the above, regeneration can take place in mainly two different ways.
    On the one hand, regeneration can take place through so-called oxygen (O2) -basedregeneration, also called active regeneration. When activeregeneration takes place a chemical process mainly according to eq. 1:C + Og = QO2 + heat (eq. 1)Thus, during active regeneration, carbon plus oxygen are converted tocarbon dioxide plus heat. However, this chemical reaction is strongtemperature dependent, and requires relatively highfilter temperatures for that appreciable reaction rateshould occur at all. Typically a minimum is requiredparticle filter temperature of 500 ° C, but preferably shouldthe filter temperature must be even higher for the regeneration tohappen at the desired speed.
    However, the maximum temperature that can be used is often limitedduring active regeneration of tolerances for the constituentsthe components. For example. often has the particle filter 202 and / or(where present) a subsequent SCR catalystdesign constraints with respect to itmaximum temperature to which they may be exposed. This causesthe active regeneration can have a component maximumpermissible temperature which is undesirably low. At the same time, thena very high minimum temperature to anyone usefulreaction rate should occur at all. At the activethe regeneration burns the soot load in the particle filter 202normally substantially complete. That is, a totalregeneration of the particle filter is obtained, after which the soot level inthe particle filter is essentially 0%.
    Today, it is increasingly common for vehicles, in addition to particulate filters202, is also equipped with SCR catalysts 201, so itactive regeneration can cause problems in the form ofoverheating for the subsequent SCRthe catalyst treatment process.l0l5l3At least in part because of this reason applythe present invention, instead of the active ones described aboveregeneration, NO2-based (passive) regeneration. When passiveregeneration is formed, according to eq. 2 below, nitric oxide andcarbon monoxide in a reaction between carbon and nitrogen dioxide:NO2 + C = NO + CO (eq. 2)The advantage of passive regeneration is desirablereaction rates, and thus the rate at whichthe filter is emptied, achieved at lower temperatures. Typically happensparticle filter regeneration in passive regeneration intemperatures in the range 200 ° C - 500 ° C, although temperaturesin the high part of the range is normally preferable.
    Regardless of this, this constitutes, compared to when activeregeneration, significantly lower temperature range a largeadvantage in e.g. presence of SCR catalysts, because itthere is no risk of such a hightemperature level is reached, that the risk of the SCR catalystdamaged exists.
    As described above, the differential pressure is determined abovethe particulate filter 202 by means of the differential pressure sensor209. The differential pressure is then used to estimatethe soot load in the particle filter 202. In previously known solutionsthe differential pressure is assumed to follow a curve for a soot load such asfunction of the volume flow through the particle filter.
    Two examples of such curves are shown in Figure 3, in whichdifferential pressure across the particulate filter is shown as a function ofthe volume flow of different soot loads for a particulate filtersubstantially free of water. The lower curve 30l shows herea differential pressure curve across the substrate itself inthe particle filter, that is, a curve forthe differential pressure when the particulate filter is free of soot, that14that is to say 0 g / l soot. The upper curve 302 shows a curve forthe differential pressure across the particulate filter reaches the particulate filtercontains stored soot. In this example containsthe particle filter has 5 g / l soot.
    In the past, curves such as those in Figure 3 have been relied upondetermination of soot load in the particulate filter. However, this givesapproximation of the ratio differential pressure, soot load andvolume flow not reliable values for the soot load, whichthere are several reasons for.
    One problem with the approximation is that using sensors hasinherent inaccuracies and also individual spreads,which makes it difficult to get an exact measure of where oneach curve system is currently in place. Thisnaturally results in difficulties in accurately determiningthe soot load in the particle filter 202 based on the respective curve.
    Furthermore, condensation water accumulates in the porous of the particle filterstructure when the exhaust gas purification system is inactive and cooled.
    Condensation in the particle filter has previously been a sourceto inaccurate estimates of the soot load, becausethe condensed water also it causes back pressure in the particle filter.
    An additional problem with this approximation is that it canbe complicated to estimate the amount of recondensation ofwater from the exhaust gases generated during operation of the vehicle ifthe temperature of the exhaust gases temporarily drops, which contributes toerrors in previously known estimates of soot load.
    According to the present invention, the above problems are solvedby a suitable time to measure the pressure drop acrossthe particle filter is determined, and where the pressure drop at thisspecific time is used for estimating the soot load inthe particle filter. According to the invention, the estimation is to be performedwhen the exhaust volume flow exceeds a flow threshold value, thenthe particulate filter is substantially free of water, and thenthe temperature of the particle filter 202 exceeds a firsttemperature threshold.
    Since the exhaust gas volume flow according to the present inventionexceeds a flow threshold value, becomes the differential pressureat the time of estimation large relative to the accuracy ofdifferential pressure sensor 209, resulting in one moreaccurate measurement. If one, as in previously known solutions, does notensures that the exhaust gas volume flow exceeds a threshold value,the differential pressure risks not being large in proportionto the accuracy of the sensor, which may result in incorrectsoot load estimates. According to previously known solutions can thusthe differential pressure be so small at the time of estimation thatthe accuracy of the sensor can be a significant source of error.
    Since the estimation, according to the present invention, is performedwhen the particle filter is free of condensed water, one is obtainedmore accurate value for the soot load, which is not affected byback pressure caused by condensation water present in the particle filter202 at the start of operation of the vehicle.
    Since the estimation, according to the present invention, is performedat a time when the temperature of the particulate filter exceedsa first temperature threshold value, the effect ofpossible recondensation of water in the pores of the particulate filterwhen the temperature drops temporarily during operation of the vehicle.
    Thus, a more accurate value for is obtainedthe differential pressure for a given exhaust volume flow and aflow resistance.
    In summary, by utilizing the presentinvention an estimate of the soot load, which essentially does notnegatively affected by sensor accuracies, condensate as in16varies to varying degrees in the particulate filter at start-up,or any condensation of water during operation ofthe vehicle as the exhaust gas temperature may temporarily drop belowthe level at which water in the exhaust gases can condense again atthe particle filter 202.
    According to an embodiment of the present invention, asize of the exhaust volume flow based on an exhaust mass flowthrough the exhaust purification system 200, a pressure upstream fromthe particulate filter 202, and at a temperature for the particulate filter202.
    There are different ways to calculate the exhaust mass flow. Toexample, it can be calculated based on a signal from amass flow sensor 214, which is arranged at the inlet tothe internal combustion engine 101 and is connected to the control unit 208.
    Exhaust mass flow can also be calculated, for example, based onpressure and temperature at the inlet housing of the internal combustion engine,with compensation for possible use of EGR valve (EGR,Exhaust Gas Recirculation).
    The pressure upstream of the particle filter 202 can be determinedby means of a pressure signal from a pressure sensor 213, in relationto the atmospheric pressure, where this pressure sensor 213 is arrangedupstream from the particle filter 202 and is connected tothe control unit 208. The temperature of the particle filter candetermined based on a temperature signal from at least onetemperature sensors 211, 212 for said particle filter 202, therethe temperature sensor can be arranged nearbythe particulate filter, either upstream of the particulate filter 211,or downstream of the particle filter 212.
    The flow threshold value, which according to the invention shouldexceeded before the estimation of the soot load is to be performed, shouldset to a value that is high enough for one17accuracy of said pressure sensor is ensured, whichunderstood by a professional are different for different donors. Typically canthis flow threshold value corresponds to a flow within the range200 to 300 liters per second. According to an embodiment ofAccording to the invention, this flow threshold value corresponds to a flow ofabout 250 liters per second. This ensures to usepressure sensors provide reliable output signals.
    As described above, condensate often accumulates inthe particulate filter 202, which may give a back pressure that isconfusing with soot load and therefore gives a faultyestimation of the soot load. According to an embodiment ofThe present invention provides a water content inthe particle filter 202 by means of a model. This model takes into accountto the properties of the water, in such a way that according to this modelthe particulate filter is considered to be substantially free of water ifthe particulate filter has had a temperature in excess of a secondtemperature threshold below at least one predeterminedperiod. At low temperatures for the particulate filter, toexample when the vehicle is idling, water can stillcondenses in the particulate filter. This secondtemperature threshold value therefore suitably exceeds onetemperature at which water boils away from the pores of aparticulate filter. The second temperature threshold is thereforein the temperature range 150 ° C-250 ° C. According to one embodimentof the invention, the second temperature threshold is approx200 ° C. Thus, if the particle filter maintains a temperature withinthis range, any water present will beremoved from the particle filter.
    According to one embodiment of the present inventionthe predetermined time period during which the particulate filteraccording to the model should keep a temperature withintemperature range 150 ° C-250 ° C, a time within the range 818to 12 minutes. According to an embodiment of the inventioncorresponds to this predetermined time period of about 10 minutes.
    Thus, by maintaining a temperature, which is sufficienthigh to remove water from the particle filter 202, below asufficiently long period of time, is ensured by the presentinvention that the particulate filter is substantially free ofwater. This gives a more accurate estimate of the soot load,since essentially no back pressure resulting fromthe condensed water is added to the back pressure resulting fromsoot load.
    As stated above, condensed water gives increased back pressure overthe particle filter 202. When the particle filter 202 has been heated oneonce you want to avoid estimating the soot load at a time thenthere is a risk that water condensation will have againThis may be the case, for example, with regard to the temperature ofthe exhaust gases temporarily drop. According to an embodiment ofthe invention therefore performs the estimation of the soot load firstafter the particle filter has reached a firsttemperature threshold, which is higher than a temperature at whichwater can condense from the exhaust gases in the particulate filter. Thisfirst temperature threshold value may correspond to a temperature withinrange 140 ° C to 200 ° C. According to an embodiment ofthe invention corresponds to this first temperature threshold valueabout 170 ° C. By making the estimate only when one is so hightemperature has been reached, incorrect estimation of the soot load may be dueof any accumulation of water in the pores of the particulate filteravoided.
    When estimating the soot load, as described above,an exhaust volume flow, which is determined based on aexhaust mass flow signal, a pressure signal from a pressure sensor 213,in relation to atmospheric pressure, and on a19temperature signal from a temperature sensor 211, 212 forthe particulate filter 202. The exhaust gas mass flow and temperature havedifferent time offsets, making corresponding signalshave different mutual time shifts. In addition, these aresignals also time-shifted towards the signal from the pressure sensor213. These time shifts cause the signal tothe soot load estimate becomes very scattered, jumpy and difficult to interpret.
    The signal is simply difficult to interpret due to its choppyappearance, which entails a risk of misinterpretations.
    According to one embodiment of the invention, it is therefore filteredthe signal corresponding to the estimate of the soot load. Thisfiltration is preferably performed by means of a low-pass filter,which smooths out the sprawling appearance of the signal. This causesthis signal is given a more transparent and easy-to-interpret appearanceafter this filtering.
    Figure 4 shows a flow chart of the method according topresent invention. In a first step 401, after the startof the process, is controlled, preferably by useof the condensed water model described above, about the particulate filteris substantially free of any water that may have been present inthe particulate filter at the start of the vehicle. About the particle filteris considered to be substantially free of water and the procedure continuesto a second step 402. If the particle filter is not free fromwater, the procedure begins again from the beginning.
    In the second step 402, the exhaust volume flow is checkedexceeds the flow threshold, and if this is the case, gothe procedure proceeds to a third step 403. Ifthe exhaust volume flow does not exceed the threshold value beginsprocedure if.
    In the third step 403 of the process, it is re-checkedthe particulate filter has a temperature higher than a firsttemperature threshold. If the temperature is higher than this thresholdthe procedure proceeds to a fourth step 404. If the temperature islower than this threshold, the procedure starts again from the beginning.
    As will be appreciated by one skilled in the art, the first three steps 401, 402,403 according to the method is substantially performed in which orderany. It is also possible to implement the procedure in this waythat if the condition in each step is not met sothis condition is checked, ie the condition for justthis step, a number of additional times before the procedurestarts again from the beginning.
    The essential thing according to the procedure is that before the procedure reachesthe fourth stage 404, the exhaust volume flow shall exceed itsthreshold, the particulate filter must be substantially free ofwater and the particulate filter have a temperature in excess of thatthreshold value.
    In the fourth step 404 of the process, the soot load is estimated.
    By the conditions of the first 401, second 402 and third 403the steps are completed before the fourth step 404 can be performed, canthereby a robust and reliable estimate of the soot loadensured.
    In a fifth step 405 of the process, an earlier one is updateddetermined value for the estimation of the soot load. So here comesa new specified value for the current soot load to be writtenover the old saved value.
    Furthermore, the present invention relates to a systemarranged to perform soot load estimation in oneparticulate filter 202. The system of the invention comprisesflow means, which is arranged to determine a21exhaust volume flow for exceeds a flow threshold value.
    The system also includes water presence determination means,which is arranged to determine the presence of water inthe particulate filter, as well as temperature means, which is arranged toestimate a temperature for the particulate filter 202. The systemalso includes estimating means, which is arranged to performthe estimate of the soot load for the particulate filter 202 thenthe exhaust volume flow exceeds a flow threshold value,the particulate filter is substantially free of water, andthe temperature of the particle filter exceeds a firsttemperature threshold.
    The system is further arranged to comprise means for executionof the various embodiments of the method described aboveaccording to the invention.
    Furthermore, the invention relates to a vehicle according to figure1a, which includes a particle filter 202 and a systemaccording to the invention, which is arranged to perform oneestimation of a soot load in the particulate filter by the methodaccording to the invention.
    The present invention has been exemplified above in connectionto vehicles. However, the invention is also applicable toarbitrary vessels where the exhaust gas purification system as above isapplicable, such as e.g. water or aircraft withcombustion / regeneration processes as above.
    权利要求:
    Claims (21)
    [1]
    A method of estimating a soot load in a particulate filter (202) in an exhaust gas purification system (200), said estimation utilizing a pressure drop across said particle filter (202) to determine said soot load, characterized in that said estimation is performed at a time when a exhaust volume flow for said exhaust gas purification system (200) exceeds a flow threshold value, said particulate filter (202) is substantially free of water, and a temperature of said particulate filter (202) exceeds a first temperature threshold value.
    [2]
    The method of claim 1, wherein a magnitude of said exhaust volume flow is determined based on an exhaust mass flow for said exhaust gas purification system, a pressure upstream of said particulate filter (202) and at a temperature of said particulate filter (202).
    [3]
    A method according to claim 2, wherein - said pressure is determined by means of a pressure sensor (213) arranged upstream of said particle filter; and - said flow threshold value is set to a value high enough to ensure an accuracy of said pressure sensor (213).
    [4]
    The method of claim 3, wherein said flow threshold value corresponds to a flow in the range of 200 to 300 liters per second.
    [5]
    The method of claim 4, wherein said flow threshold value corresponds to about 250 liters per second. 10 15 20 25 23
    [6]
    A method according to any one of claims 1-5, wherein a water content in said particle filter (202) is determined by means of a model.
    [7]
    The method of claim 6, wherein, according to said model, said particulate filter (202) is substantially free of water if said particulate filter (202) has had a temperature in excess of a second temperature threshold for at least a predetermined period of time.
    [8]
    The method of claim 7, wherein said second temperature threshold exceeds a temperature at which water boils out of pores in said particle filter (202).
    [9]
    The method of claim 8, wherein said second temperature threshold value corresponds to a temperature in the range of 150 ° C-250 ° C.
    [10]
    The method of claim 9, wherein said second temperature threshold value corresponds to about 200 ° C.
    [11]
    A method according to any one of claims 7-10, wherein said predetermined time period corresponds to a time in the range of 8 to 12 minutes.
    [12]
    The method of claim 11, wherein said predetermined time period corresponds to about 10 minutes.
    [13]
    A method according to any one of claims 1-12, wherein said first temperature threshold value is higher than a temperature at which water in exhaust gases in said exhaust gas purification system (200) can condense in said particulate filter (202) and depends on a temperature of said exhaust gases. 10 15 20 25 30 24
    [14]
    The method of claim 13, wherein said first temperature threshold value corresponds to a temperature in the range of 140 ° C to 200 ° C.
    [15]
    The method of claim 14, wherein said first temperature threshold value corresponds to about 170 ° C.
    [16]
    A method according to any one of claims 1-15, wherein, when a value for said estimate is determined at said time, a previously determined value for said estimate is updated.
    [17]
    A method according to any one of claims 1-16, wherein a signal corresponding to said estimate is filtered.
    [18]
    A computer program comprising program code, which when said program code is executed in a computer causes said computer to perform the method according to any of claims 1-17.
    [19]
    A computer program product comprising a computer readable medium and a computer program according to claim 18, wherein said computer program is included in said computer readable medium belonging to any of the group comprising: ROM (Read-Only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically EPROM) and hard disk drive.
    [20]
    A system arranged to perform estimation of a soot load in a particulate filter (202) in an exhaust gas purification system (200), said estimation utilizing a pressure drop across said particulate filter (202) to determine said soot load, characterized in that said system comprises: - flow means, arranged to determine if an exhaust volume flow for said exhaust gas purification system (200) exceeds a flow threshold value; water presence determining means, arranged to determine the presence of water in said particle filter (202); temperature means, arranged to estimate a temperature of said particle filter (202); and - estimating means, which is arranged to perform said estimation at a time when said exhaust volume flow exceeds a flow threshold value, said particulate filter (202) is substantially free of water, and said temperature of said particulate filter (202) exceeds a first temperature threshold value.
    [21]
    Vehicle (100), characterized in that said vehicle (100) comprises: - a particulate filter (202); and - a system for estimating a soot load in said particle filter (202) according to claim 20.
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    同族专利:
    公开号 | 公开日
    US9222396B2|2015-12-29|
    BR112013002994A2|2020-10-27|
    EP2612004A1|2013-07-10|
    CN103069122A|2013-04-24|
    SE535155C2|2012-05-02|
    KR20130050999A|2013-05-16|
    RU2535440C2|2014-12-10|
    EP2612004A4|2014-03-26|
    WO2012030279A1|2012-03-08|
    RU2013114240A|2014-10-10|
    US20130145822A1|2013-06-13|
    EP2612004B1|2015-08-12|
    KR101471581B1|2014-12-10|
    BR112013002994B1|2021-07-20|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4656832A|1982-09-30|1987-04-14|Nippondenso Co., Ltd.|Detector for particulate density and filter with detector for particulate density|
    RU2070972C1|1994-09-20|1996-12-27|Иван Иванович Кутыш|Method for cleaning waste gases from solid particles|
    DE10100418A1|2001-01-08|2002-07-11|Bosch Gmbh Robert|Method and device for controlling an exhaust gas aftertreatment system|
    FR2895017B1|2005-12-20|2008-01-25|Renault Sas|METHOD AND SYSTEM FOR REGENERATING THE PARTICLE FILTER OF A THERMAL ENGINE|
    EP1854971B1|2006-05-09|2009-08-05|Ford Global Technologies, LLC|Method and apparatus for the estimation of the particle filter loading|
    JP2008139053A|2006-11-30|2008-06-19|Denso Corp|Method of inspecting pressure loss in honeycomb structure|
    US8011180B2|2007-08-16|2011-09-06|Ford Global Technologies, Llc|Particulate filter regeneration|
    JP5030020B2|2007-10-19|2012-09-19|株式会社デンソー|Exhaust gas purification device for internal combustion engine|
    US8051645B2|2007-12-18|2011-11-08|Ford Global Technologies, Llc|Determination of diesel particulate filter load under both transient and steady state drive cycles|
    DE102008058280A1|2007-12-18|2009-06-25|Ford Global Technologies, LLC, Dearborn|Determining the load of a diesel particulate filter during both unsteady and stationary driving cycles|
    US8266890B2|2009-06-10|2012-09-18|International Engine Intellectual Property Company, Llc|Preventing soot underestimation in diesel particulate filters by determining the restriction sensitivity of soot|
    KR101326812B1|2011-05-17|2013-11-07|현대자동차 주식회사|Exhaust gas post treatment system|JP5906655B2|2011-10-14|2016-04-20|トヨタ自動車株式会社|Exhaust control device for internal combustion engine|
    IN2014MN02660A|2012-06-21|2015-08-28|Mack Trucks|
    US9328645B2|2014-02-24|2016-05-03|GM Global Technology Operations LLC|Detecting over-temperature in exhaust system|
    US9322312B2|2014-03-05|2016-04-26|GM Global Technology Operations LLC|Ambient humidity and temperature correction to particulate filter soot rate|
    CN103925046B|2014-04-18|2016-03-16|高华|Automobile tail gas filtering device|
    US9726058B2|2015-01-08|2017-08-08|Ford Global Technologies, Llc|Idle speed GPF regeneration|
    US9523303B2|2015-01-29|2016-12-20|Ford Global Technologies, Llc|System and method for regenerating a particulate filter|
    CN105545415B|2016-03-14|2018-03-27|侯东风|A kind of non-maintaining motor-vehicle tail-gas particle purifying device and method|
    GB2548561B|2016-03-18|2020-02-19|Caterpillar Inc|Exhaust backpressure detection|
    CN105840286A|2016-03-24|2016-08-10|乐视控股（北京）有限公司|Automobile tail gas treatment equipment|
    CN107023354A|2017-05-26|2017-08-08|成都东浩散热器有限公司|Filter plant on exhaust emissions|
    FR3072721A1|2017-10-23|2019-04-26|Psa Automobiles Sa|METHOD OF ESTIMATING LOADING IN A SUES OF A THERMAL ENGINE PARTICLE FILTER|
    US10156175B1|2018-02-15|2018-12-18|GM Global Technology Operations LLC|Method and system for rationalizing a delta pressure sensor for a gasoline particulate filter in a vehicle propulsion system|
    DE102018114779B4|2018-06-20|2020-07-30|Dr. Ing. H.C. F. Porsche Aktiengesellschaft|Method for determining the loading condition of a particle filter of a motor vehicle|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1050891A|SE535155C2|2010-08-31|2010-08-31|Procedure and systems for exhaust gas purification|SE1050891A| SE535155C2|2010-08-31|2010-08-31|Procedure and systems for exhaust gas purification|
    KR1020137008379A| KR101471581B1|2010-08-31|2011-08-24|Method and system for exhaust cleaning|
    BR112013002994-3A| BR112013002994B1|2010-08-31|2011-08-24|METHOD FOR ESTIMATION AND ADAPTED SYSTEM FOR ESTIMATING A SOOT LOAD ON A PARTICLE FILTER AND VEHICLE|
    US13/818,318| US9222396B2|2010-08-31|2011-08-24|Method and system for exhaust cleaning|
    RU2013114240/06A| RU2535440C2|2010-08-31|2011-08-24|Method and system of exhaust gases cleaning|
    PCT/SE2011/051016| WO2012030279A1|2010-08-31|2011-08-24|Method and system for exhaust cleaning|
    EP11822214.0A| EP2612004B1|2010-08-31|2011-08-24|Method and system for exhaust cleaning|
    CN2011800415466A| CN103069122A|2010-08-31|2011-08-24|Method and system for exhaust cleaning|
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