SE1450859A1 - Method and system for determining cleaning needs for a particle filter - Google Patents

Abstract

The present invention relates to a method for determining the cleaning need for a particle filter (265) of an engine (231) exhaust gas purification system from an ash occurrence point of view, comprising the steps of: - determining a measure of ash accumulation accumulated in said particle filter (265), and - determining (s340) ) said measure on the basis of determined heat capacity (C1; C2) of said particle filter (265) at at least two different states regarding accumulated ash presence.Fig. 2

Description

TECHNICAL FIELD The invention relates to a method for determining the cleaning requirements for a particulate filter in an engine exhaust purification system Iran ash deposit point of view. The invention also relates to a computer program product comprising program code for a computer to implement a method according to the invention. The invention also relates to a system for determining the cleaning needs regarding a particle filter of an engine exhaust purification system from an ash occurrence point of view and to a motor vehicle which is equipped with the system.

BACKGROUND Exhaust gas cleaning systems of today's motor vehicles include a number of different components. For example, an exhaust gas purification system may include a DOC unit (Diesel Oxidation Catalyst) arranged in a passage downstream of an internal combustion engine of the vehicle. Other components that may be arranged downstream of said engine are a DPF (Diesel Particulate Filter) unit and a SCR (Selective Catalytic Reduction) catalyst.

For many reasons, it is unfortunate to be able to diagnose individual components of exhaust gas cleaning systems in motor vehicles, such as trucks and buses. Diagnosis of components of exhaust gas cleaning systems in motor vehicles can, for example, be Unskvard father to determine radiating performance and / or function of the various components. Diagnosis of different components in exhaust gas cleaning systems can in some states be subject to laws, regulations or 2 directives, which of course vehicle manufacturers must comply with, not at least from an environmental and competitive perspective.

The said DPF unit is arranged to capture e.g. soot and ash Iran an engine. Said soot and ash can get Iran engine fuel or lubricant in the engine. Soot includes combustible matter while ash contains non-combustible matter. Soot is a term for the combustion residues that are formed when there is an excess of carbon in relation to oxygen. Ash is the solid residual product after combustion of organic substances. Soot can thus be at least partially incinerated, while ash cannot be incinerated. Ash can be the non-combustible part of soot.

When soot and ash are stored in the said DPF unit, a back pressure increases in the exhaust gas purification system. This contributes to unwanted parasite losses in the system where useful work is involved in forcing exhaust gases from the engine through the said DPF unit. Either this will result in a driving power reduction of the vehicle's driveline or an fuel consumption of the engine will be increased to maintain the desired driving power of said driveline.

At certain intervals, said DPF unit can be actively regenerated to reduce or substantially eliminate the amount of stored soot. However, stored ash needs to be removed from the said DPF unit manually with a certain regularity by means of, for example, compressed air. This procedure is time consuming, costly and often cumbersome for service personnel to perform. Today, a degree of storage of said DPF unit with respect to ash can be determined by so-called clod shaving, wherein the said storage degree with respect to ash is continuously calculated according to a predetermined calculation model. This method can be based on an average value for storage capacity for a number of different vehicle individuals and thus has shortcomings in accuracy for application in specific vehicle individuals. It should also be noted that the engines' 3 oil consumption shows a strong individual spread and variation over time that is significant.

Thus, it is problematic today to determine relevant intervals for service or replacement of DPF units with exhaust gas purification systems, such as motor vehicles.

US20080264045 describes a method for dispensing if it is sufficient to regenerate a particulate filter having an exhaust gas purification system or if said particulate filter is in need of service. According to this method, a differential pressure is fed across the particle filter to supply a degree of filling thereof.

In addition, an electrical resistance is fed across said particle filter to determine whether there is ash stored in said particle filter or not.

OBJECT OF THE INVENTION There is thus a need to reliably determine the cleaning needs of a DPF unit having an exhaust purification system having a motor vehicle.

There is a need to diagnose a DPF device in an efficient, reliable and user-friendly manner in terms of performance.

An object of the present invention is to provide a new and advantageous method for determining the cleaning needs of a particulate filter having an engine exhaust purification system from the ash occurrence point of view.

An object of the present invention is to provide a new and advantageous method for performance control of a DPF unit having an exhaust gas purification system. Another object of the invention is to provide a new and advantageous system for determining the cleaning needs of a particulate filter of an engine exhaust purification system from the ash occurrence point of view and a new and advantageous computer program for determining the cleaning needs of a particulate filter of an engine exhaust purification system from the ash point of view.

A further object of the invention is to provide an alternative method for determining the cleaning requirements for a particulate filter of an engine exhaust purification system from an ash occurrence point of view, an alternative system for determining the cleaning requirements for a particulate filter of an engine exhaust purification system from an ash occurrence point of view and an alternative computer program. For determining the cleaning needs regarding a particulate filter of an engine exhaust purification system from an ash occurrence point of view.

A further object of the invention is to provide a method of an exhaust purification system, an apparatus of an exhaust purification system and a computer program for providing a reliable performance check of a DPF unit of a motor vehicle.

A further object of the invention is to provide a method of an exhaust purification system, a system of an exhaust purification system and a computer program for providing a reliable performance check of a DPF unit of an SCR system, which SCR system may be installed in a motor vehicle.

SUMMARY OF THE INVENTION These and other objects, which will become apparent from the following description, are accomplished by a method and system, as well as motor vehicles, computer programs and computer program products of the kind initially indicated and further having the features set forth in the dependent part of the appended independent claims. Preferred embodiments of the method and system are defined in the appended dependent claims.

The embodiments of the system have corresponding advantages as corresponding embodiments of the method mentioned above.

According to one aspect of the present invention, there is provided a method of determining cleaning requirements for a particulate filter having an engine exhaust purification system from an ash occurrence point of view. The method comprises the steps of: - determining a mat of ash accumulated in said particle filter; and - determining said mat on the basis of determined heat capacity, said particle filter having at least two different states regarding accumulated ash occurrence.

In this case, a first mat is determined in a first state in which no, or substantially no, ash is present in said particle filter. This constitutes a reference state and reflects a heat capacity of the said particle filter without stored ash. A second mat is then determined in a second state in which ash has accumulated and is stored in said particle filter. This constitutes a state which reflects a heat capacity of the said particle filter when the ash is stored. By comparing these two mats, ash occurrence can be determined in a simple, user-friendly, robust and reliable manner according to the inventive method. Furthermore, the inventive method is adapted to the specific vehicle / engine individual in which said particle filter is arranged.

The method may comprise the steps of: - determining a first value of said heat capacity having said particle filter based on a first state including established parameter values regarding exhaust mass flow from said engine and a 6 temperature difference regarding exhaust temperature upstream and downstream of said particulate filter and previous particulate filter. determining a second value of said heat capacity of said particle filter based on the determination of said first value of said heat capacity and a second condition including determined parameter values regarding exhaust mass flocation from said engine and a temperature difference regarding exhaust temperature upstream and downstream of condition; and - determining said mat on the basis of a comparison between the two values thus determined on said heat capacity. Said comparison may involve comparing an absolute difference or absolute ratio with respect to the thus determined two values of said heat capacity with a respective adequate threshold value.

By considering a temperature inertia of the particle filter, which largely depends on the amount of ash stored, said matte ash accumulation accumulated in said particle filter can be determined in a user-friendly and reliable manner. The thermal inertia has the so-called particle filter due to the amount of soot and ash stored. In this case, it is important to point out that stored ash has a strong effect on the thermal inertia, the particulate filter has a relatively large amount of soot stored. Density has ash is in the order of 10 times higher than has soot.

By determining heat energies based on the radiating exhaust mass floc 25 and said temperature difference regarding exhaust temperature upstream and downstream said particle filter for said two different states, the equation below can be used according to an aspect of the present invention. 7 MF1 x Cl x IT1I = MF2 x C2 x IAT21 In this case, a first heat energy of the system is determined in a first state by multiplying a radiating exhaust mass flow MF1 by a measure of heat capacity C1 and an absolute difference IiT1I between said exhaust temperatures upstream and downstream of the said particulate or downstream.

Said first mat of heat capacity C1 can be determined in a suitable manner, since essentially no ash is present in said particle filter. This can be done, for example, when the vehicle leaves a manufacturing plant.

In this case, said second heat capacity mat C2, in a second state, can be calculated by said energy relationship, on the basis of a determined second exhaust mass flow MF2 and an absolute difference IAT2I between said exhaust temperatures upstream and downstream of said particulate filter in said second state.

The method may comprise the step of: - determining said value of said heat capacity in connection with transient processes of exhaust gas temperature upstream and / or downstream of said particle filter; and / or - determining said value of said heat capacity when a determined absolute temperature difference with respect to exhaust gas temperature upstream and downstream said particle filter exceeds a predetermined value. In this case, an accurate method is provided for determining a mat of ash accumulation accumulated in the said particle filter.

The method may comprise the step of: - regenerating said particle filter with respect to soot particles before said matte with respect to accumulated ash deposit is determined. In this case, said particle filter advantageously comprises only ash, which provides a reliable method for determining the ash presence of said particle filter.

The method may comprise the step of: - predicting the need for removal of ash from said particle filter based on determining the development of said mat over time. In this case, an operator of said engine with an exhaust gas purification system, including a particulate filter, can become aware and plan in good time to clean or replace said particulate filter. Advantageously, more adequate service intervals for said particle filters can be provided in conjunction with prior art. This entails a reduced risk of storing anti & large amounts of ash in the particle filter, which is advantageous from, among other things, performance considerations.

The method may comprise the steps of: - determining the need to remove accumulated ash from said particle filter at a predetermined achieved value with respect to said mat; and - in the event of a determined need to remove accumulated ash from said particle filter, for an operator of said engine, indicate said need. In this case, an operator of said engine with an exhaust gas purification system, including a particulate filter, can become aware and plan in good time to clean or replace said particulate filter. Advantageously, more adequate service intervals for said particle filters can be provided in conjunction with prior art. This entails a reduced risk of storing excessive amounts of ash in the particle filter, which is advantageous from, among other things, performance considerations.

According to one aspect of the present invention, there is provided a system for determining cleaning requirements regarding a particulate filter of an engine exhaust purification system from an ash occurrence point of view, comprising: means adapted to determine a mat of ash accumulation accumulated in said particulate filter; and means adapted to determine said mat on the basis of determined heat capacity have said particle filter at at least two different states regarding accumulated ash occurrence.

The system may comprise: means adapted to determine a first value of said heat capacity having said particulate filter based on a first state including established parameter values regarding exhaust mass flow from said engine and a temperature difference regarding exhaust temperature upstream and downstream of said particulate filter and expected layer of ash precipitate; means adapted to determine a second value of said heat capacity have said particle filter based on the determination of said first value of said heat capacity and a second condition including determined parameter values regarding exhaust mass flow from said engine and a temperature difference regarding exhaust temperature upstream and downstream respectively downstream and downstream said first condition; and means adapted to determine said mat on the basis of a comparison between the two values of said heat capacity thus determined.

The system may comprise: means adapted to determine said value of said heat capacity in connection with transient processes of exhaust gas temperature upstream and / or downstream of said particle filter; and / or means adapted to determine the nominal value of said heat capacity when a determined absolute temperature difference with respect to the exhaust gas temperature upstream and downstream of said particle filter exceeds a predetermined value.

The system may comprise: means adapted to regenerate said particulate filter with respect to soot particles before said matte with respect to accumulated ash deposit is determined.

The system may comprise: means adapted to predict the need for removal of ash from said particle filter based on determining the development of said mat over time.

The system may comprise: - means adapted to determine the need to remove accumulated ash from said particle filter at a predetermined achieved value with respect to said mat; and means adapted to, at a determined need to remove accumulated ash from said particulate filter, an operator of said engine, indicate said need.

According to one aspect of the present invention, there is provided a motor vehicle comprising a system according to any of claims 7-12.

The motor vehicle can be anything from a truck, bus or car.

According to one aspect of the present invention, there is provided a computer program in an exhaust gas purification system, said computer program comprising program code for causing an electronic control unit or a computer connected to the electronic control unit to perform the steps of any of claims 1-6. According to one aspect of the present invention, computer programs are provided in an exhaust gas purification system, said computer program comprising program code for causing an electronic control unit or a computer connected to the electronic control unit to perform the steps according to any of claims 1-6, when said program code ' According to one aspect of the present invention, computer programs are provided in an exhaust gas purification system, wherein said computer program comprises program code stored on a computer readable medium for causing an electronic control unit or a computer connected to the electronic control unit to perform the steps of any of claims 1- 6.

According to one aspect of the present invention, computer programs are provided in an exhaust gas purification system, said computer program comprising program code stored on a computer readable medium for causing an electronic control unit or a computer connected to the electronic control unit to perform the steps of any of claims 1- 6, when said program code crosses said control unit or said computer.

According to one aspect of the present invention, there is provided a computer program product comprising a program code stored on a computer readable medium performing the procedure steps according to any one of claims 1-6, when said program code is crossed on an electronic control unit or a computer connected to the electronic control unit. .

According to one aspect of the present invention, there is provided a computer program product comprising a program code non-volatile stored on a computer readable medium for performing the procedure steps according to any one of claims 1-6, when said program code is crossed on an electronic controller or other computer connected. to the electronic control unit. Further objects, advantages and novel features of the present invention will become apparent to those skilled in the art from the following details, as well as through the practice of the invention. While the invention is described below, it should be understood that the invention is not limited to the specific details described. Those skilled in the art having access to the teachings herein will recognize additional applications, modifications, and incorporations within other fields which are within the scope of the invention.

SUMMARY DESCRIPTION OF THE DRAWINGS The present invention will be better understood by reference to the following detailed description of cargo taken in conjunction with the accompanying drawings, in which like reference numerals appear in like manner throughout the many views, and in which: Figure 1 schematically illustrates a vehicle, according to a embodiment of the invention; Figure 2 schematically illustrates a subsystem of the vehicle shown in Figure 1, according to an embodiment of the invention; Figure 3a schematically illustrates a flow chart of a method, according to an embodiment of the invention; Figure 3b schematically illustrates in further detail a flow chart of a method, according to an embodiment of the invention; and Figure 4 schematically illustrates a computer, according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE FIGURES Referring to Figure 1, a side view of a vehicle 100 is shown. The exemplary vehicle 100 consists of a tractor 110 and a trailer 112. The vehicle may be a heavy vehicle, such as a truck or a bus. The vehicle can alternatively be a car. The term "lank" refers to a communication link which may be a physical line, such as an optoelectronic communication line, or a non-physical line, such as a wireless connection, for example a radio or microwave line.

If the term "reductant" or "reducing agent" is used to mean an agent used to react with certain emissions in an SCR system, the engine has an exhaust gas purification system. These emissions can e.g. be NON gas. Said reductant is according to an embodiment so-called AdBlue. Of course, other types of reductants can be used.

It should be noted that the invention is suitable for application having a suitable exhaust gas purification system comprising a DP F unit. The inventive method and the inventive system make choices for other platforms which include an exhaust gas purification system of motor vehicles, such as e.g. watercraft. The watercraft can be of any kind, such as e.g. motor boats, ships, ferries or ships.

The inventive method and the inventive system in an exhaust gas purification system according to an aspect of the invention may also be selected by e.g. systems including tractors, dumpers, power tools, industrial engines and / or powered industrial robots.

The inventive method and the inventive system in an exhaust gas purification system according to an aspect of the invention also illuminate choices for different types of power plants, such as e.g. an electric power plant comprising a diesel generator.

The inventive method and the inventive system of an exhaust gas purification system are suitable for any engine system 14 which includes an engine, DPF unit and possibly an SCR system, such as e.g. at a locomotive or other platform.

The inventive process and the inventive system of an exhaust gas purification system make choices for a system comprising a NOR generator and a DPF unit, for example a diesel engine, the exhaust gases of which are to be purified.

Fig. 2 schematically illustrates a subsystem 289 of the vehicle 100 shown in Fig. 1, according to an embodiment of the invention. Said subsystem 289 forms part of an exhaust gas purification system of the vehicle 100.

An engine 231 is provided, which in operation causes an exhaust gas flow which is led via a first passage 235 to a DOC unit 260. A second passage 245 is arranged to direct exhaust gases from said DOC unit 260 to a DPF unit 265. Said DPF Unit 265 includes a Diesel Particulate Filter. A third passage 255 is provided to direct exhaust gases from said DPF unit 265 to an SCR catalyst arrangement 270. Said SCR catalyst arrangement 270 may alternatively be termed SCR catalyst. A fourth passage 256 is provided to direct exhaust gases from said SCR catalyst arrangement 270 to an environment of the vehicle 100.

According to an alternative embodiment, the DOC unit 260 and / or the SCR catalyst 270 can be omitted.

In the event that said exhaust gas purification system comprises an SCR catalyst 270, a dosing unit (not shown) is provided, which is arranged to dispense reducing agent into said third passage 255 for catalytic exhaust purification with respect to NOR gas.

The first control unit 200 is arranged for communication with the motor 231 via a long L231. The first control unit 200 is arranged to control operation of said engine 231. The first control unit 200 is for instance arranged to control industry metering to the combustion chamber of said engine 231.

Fuel metering means (not shown) may be arranged upstream of said DOC unit 260 and downstream of said motor 231. The first control unit 200 is arranged for communication with said fuel metering means via a dedicated link (not shown). The first control unit 200 is arranged to control the dosing of fuel, for example diesel, into said first passage 2 by means of said industry dosing means in order to effect a so-called active regeneration of said DPF unit 265.

A first temperature sensor 237 is arranged upstream of said DPF unit 265 at said second passage 245. Said first temperature sensor 237 is arranged for communication with the first control unit 200 via a long L237. Said first temperature sensor 237 is arranged to continuously feed / detect / determine a radiating first temperature Ti of the exhaust gases in the second passage 245. Said first temperature sensor 237 is arranged to continuously send signals S237 including information about said radiating first temperature Ti of the exhaust gases in said second passage 245 to the first control unit 200 via the line L237.

A second temperature sensor 277 is arranged downstream of said DPF unit 265 at said third passage 255. Said second temperature sensor 277 is arranged for communication with the first control unit 200 via a long L277. Said second temperature sensor 277 is arranged to continuously supply a radiating second temperature T2 of the exhaust gases in the third passage 255. Said second temperature sensor 277 is arranged to continuously send signals S277 including information about said 16 radiating second temperature 12 of the exhaust gases in said third passage 255 to the first control unit 200 via the line L277.

According to an exemplary embodiment, a third temperature sensor 233 may be arranged upstream of said DOC unit 260 at said first passage 235. Said third temperature sensor 233 is arranged for communication with the first control unit 200 via a line L233. Said third temperature sensor 233 is arranged to continuously feed / detect / determine a radiating third temperature T3 of the exhaust gases in the first passage 233. Said third temperature sensor 233 is arranged to continuously send signals S233 including information about said radiating third temperature T3 having the exhaust gases in said first passage 233 to the first control unit 200 via the line L233.

According to one aspect of the present invention, said first temperature T1 and said second temperature T2 are used to determine a temperature difference across said DPF unit 265, whereby a radiating heat capacity can be determined according to the inventive method. According to an alternative embodiment, said third temperature T3 and said second temperature 12 may be used to determine a temperature difference over said DPF unit 265 and said DOC unit, a radiating heat capacity for the combination of said DPF unit 265 and said DOC unit 260. of can be determined and used in a congruent manner (regarding the use of the temperatures Ti and 12) according to an aspect of the inventive process. This embodiment is not described in further detail here.

A sensor (not shown) for supplying a radiating exhaust mass flow MF may be provided in the first passage 235. The said exhaust mass flow sensor is arranged to continuously determine a radiating exhaust mass flow MF in the first passage 235 and send signals including the information therefor to the control unit 200. via a dedicated link (not shown). According to one embodiment, the first control unit 200 is arranged to determine by means of a calculation model stored therein a radiating exhaust mass flow MF in the first passage 235. Said radiating exhaust mass flow MF in the first passage 235 can be determined on the basis of e.g. a fixed operating state has the motor 231.

An exhaust mass flow determined at said first state (since substantially no ash is stored in said DPF unit 265) is hereby designated as MF1 and an exhaust mass flow determined at said second state (when a certain amount of ash is stored in said DPF unit 265) is referred to herein as as MF2.

The first control unit 200 may be arranged to determine a mat of ash accumulated in said particle filter 265. This can be done by determining said mat on the basis of determined heat capacity, said particle filter 265 having at least two different states regarding accumulated ash occurrence.

The first control unit 200 may be arranged to determine a first value C1 of said heat capacity, said particle filter 265 based on a first state including determined parameter values regarding exhaust mass flow MF1 from said engine 231 and a temperature difference T1-T2 or T3-T2 upstream of exhaust gas. said particulate filter 265 and related layer ash deposit.

The first control unit 200 may be arranged to determine a second value C2 of said heat capacity having said particle filter 265 based on the determination of said first value C1 of said heat capacity and a second state including determined parameter values regarding exhaust mass flow MF2 from said engine 231 and a temperature 231. T2 or T3-T2 regarding exhaust temperature upstream and downstream 18, respectively, said particle filter 265 and expected higher ash occurrence relative to said first state.

The first control unit 200 may be arranged to determine said mat on the basis of a comparison between the two values C1 and C2 thus determined on said heat capacity.

The first control unit 200 may be arranged to determine said mat on the basis of a comparison between an absolute difference, C1-C2, between the thus determined two values C1 and C2 and a predetermined threshold value TH1. In the event that said absolute difference between the thus determined two values C1 and O2 exceeds said threshold value TH1, this is taken as an indication that said particle filter 265 should / should be cleaned or replaced within a certain period of time, for example substantially immediately, as soon as possible or after a maximum number of operating hours with the engine 231, for example 10, 100 or 200 hours.

The first control unit 200 may be arranged to determine said mat on the basis of a comparison between an absolute ratio C1 / C2 between the thus determined two values C1 and O2 and a predetermined threshold value TH2. In the event that the said absolute ratio 01/02 between the thus determined two values C1 and O2 falls below the said threshold value TH2, this is taken as an indication that the said particle filter 265 should / should be cleaned or replaced within a certain period of time, for example substantially immediately, as soon as possible or after a maximum number of operating hours with the engine 231, for example 10, 100 or 200 hours.

The first control unit 200 may be arranged to determine said values C1 and O2 at said heat capacity in connection with transient processes with respect to exhaust temperature Ti or 13 upstream of said particle filter 265. The first control unit 200 may be arranged to determine said values C1 and O2 at said heat capacity in in connection with transient processes regarding exhaust temperature T2 downstream of said particle filter. The first control unit 200 may be arranged to determine a suitable time for determining said values C1 and C2 on the basis of radiating operating state of the engine 231, said operating state advantageously including transient temperature courses with respect to said exhaust temperature and / or exhaust mass flow MF.

The first control unit 200 may be arranged to determine said values C1 and C2 at said heat capacity when a determined absolute temperature difference with respect to exhaust gas temperature upstream and downstream of said particle filter exceeds a hazardous value THtemp.

Named predetermined value THtemp can be any suitable value. The predetermined value THtemp is a zero value, for example 10, 50 or 100 degrees Celsius. In principle, a larger value on THtemp is better than a lower value.

The first control unit 200 may be arranged to regenerate said particle filter 265 with respect to soot particles before said mat with respect to accumulated ash deposit is determined.

The first control unit 200 may be arranged to predict the need for removal of ash from said particle filter 265 based on determining the development of said mat over time.

The first control unit 200 may be arranged to determine the need to remove accumulated ash from said particle filter 265 at a hazardously determined value with respect to said mat. The first control unit 200 may be arranged to indicate said need in the event of a determined need to remove accumulated ash from said particle filter 265, for an operator of said motor 231. This can be done by means of presentation means 220.

Presenting means 220 are arranged for communication with said first control unit 200 via a long L220. The first control unit 200 is arranged to present a result of a performance check of the said DPF unit 265. The said result may indicate, for example, "no occurrence of ash in the DPF unit", "low occurrence of ash in the DPF unit", "medium occurrence of ash in DPF unit, cleaning is recommended shortly "or" high incidence of ash in DPF unit, cleaning / replacement should be carried out immediately ". For example, a degree of ash occurrence / impairment of the said DPF unit 26 can be presented, this degree of ash occurrence / impairment can be stated in percent. Said display means 220 may include loudspeakers for reproducing synthesized rust or other audible feedback. Said display means 220 may include a display screen, for example a so-called touch screen for visual feedback of the said result.

A second control unit 210 is arranged for communication with the first control unit 200 via a long L210. The second control unit 210 may be releasably connected to the first control unit 200. The second control unit 210 may be a control unit external to the vehicle 100. The second control unit 210 may be arranged to perform the inventive process steps.

The second control unit 210 can be used to load Over program code to the first control unit 200, in particular program code to perform the inventive method. The second control unit 210 may alternatively be arranged for communication with the first control unit 200 via an internal network in the vehicle. The second control unit 210 may be arranged to perform substantially similar functions to the first control unit 200.

Figure 3a schematically illustrates a flow chart of a method for determining cleaning needs regarding a particulate filter 265 of an engine 231 exhaust gas purification system from an ash occurrence point of view. The process comprises a process step s301. The step s301 comprises the steps of: - determining a mat on said accumulated ash deposit in said particle filter 265, 21 - determining said mat on the basis of determined heat capacity C102 of said particle filter 265 in at least two different states regarding accumulated ash deposit. After procedure step s301, the procedure is terminated.

Fig. 3b schematically illustrates in further detail a flow chart of a method for determining the cleaning need for a particle filter 265 of an engine 231 exhaust gas purification system from the ash occurrence point of view. The process includes a process step s310.

The method step s310 comprises the step of, in a first state, determining a radiating exhaust mass flow MF1 from said engine 231. This can be performed by means of a lamp sensor or by means of a calculation model stored in a memory of the first control unit 200.

The process step s310 comprises the step of, in a first state, determining a first or a third temperature value T1 13 downstream of said motor 231 and upstream of said particulate filter 265. The process step s3 comprises the step of, in a first state, determining a second temperature value T2 downstream of said particulate filter 26. This can be done by means of a lamp sensor or by means of a calculation model stored in a memory of the first control unit 200.

The process step s310 comprises the step of determining a first value C1 of said heat capacity of said particle filter 265 based on said first state including determined parameter values regarding exhaust mass flow MF1 from said engine 231 and at least one of said temperature differences T1-temperature-up2, respectively. said particulate filter 265 and related layer ash deposit. By using the energy expression MF1 x Cl x IiXT1I and a lamp constant, the said first value Cl can be determined. The absolute amount IAT11 refers to a first temperature difference in the first state, where IAT11 is equal to the temperature difference T1-T2 or T3-T2. The said value C1 of said heat capacity can be determined in connection with transient processes with respect to exhaust gas temperature upstream and / or downstream of said particle filter 265.

Said value C1 of said heat capacity can be determined when a determined absolute temperature difference with respect to exhaust gas temperature upstream and downstream of said particle filter 265 exceeds a predetermined value THtemp.

After step s310, a subsequent process step s320 is performed.

The method step s320 comprises the step of, in a second state, determining a radiating exhaust mass flow MF2 from said engine 231. This can be performed by means of a lamp sensor or by means of a calculation model stored in a memory of the first control unit 200.

The process step s320 comprises the step of, in a second state, determining a first or a third temperature value T1, 13 downstream of said motor 231 and upstream of said particulate filter 265. The process step s320 comprises the step of determining, in a second state, a second temperature value T2 downstream of said particulate filter 265. This can be done by means of a lamp sensor or by means of a calculation model stored in a memory of the first control unit 200.

The process step s320 comprises the step of determining a second value C2 of said heat capacity of said particle filter 265 based on the determination of said first value C1 of said heat capacity and a second state including determined parameter values regarding exhaust mass flow MF2 from said motor 231 and a temperature 231. -12 regarding exhaust temperature upstream and downstream of said particle filter 265 and expected higher ash occurrence relative to said first condition.

By using the energy expression 23 MF1x Cl x 'AT,' = MF2 x C2 x IAT21, the second value 02 can be triggered.

The absolute amount IAT21 refers to a first temperature difference in the second state, where IAT21 is equal to the temperature difference T1-T2 or T3-T2.

Said value C2 of said heat capacity can be determined in connection with transient processes with respect to exhaust gas temperature upstream and / or downstream said particle filter 265.

Said transient course of exhaust temperature may be associated with transient courses of said exhaust mass flow from said engine 231.

Said value 02 of said heat capacity can be determined when a determined absolute temperature difference with respect to exhaust gas temperature upstream and downstream said particle filter 265 exceeds a predetermined value THtemp.

After step s320, a subsequent process step s330 is performed.

The process step s330 comprises the step of comparing the thus determined two values C1, C2 at said heat capacity. In this case, an absolute difference between C1 and C2 can be compared with a predetermined threshold value TH1. In this case, an absolute ratio between C1 and O2 can be compared with a predetermined threshold value TH2.

After step s330, a subsequent procedure step s340 is performed.

The process step s340 comprises the step of determining said matte in said particle filter 265 accumulated ash occurrence on the basis of said comparison of determined heat capacities C1 and 02 of said particle filter 265 at said at least two different states regarding accumulated ash occurrence. The method step s340 may comprise the step of determining the need to remove accumulated ash from said particle filter 265 at a predetermined achieved value with respect to said mat.

After step s340, a subsequent process step s350 is performed.

The process step s350 may comprise the step of presenting / indicating said need, for an determined need to remove accumulated ash from said particle filter, to an operator of said engine 231 or vehicle 100. This can be done by means of said presentation means 220.

After step s350, the procedure is terminated.

Referring to Figure 4, there is shown a diagram of an embodiment of a device 500. The controllers 200 and 210 described with reference to Figure 2 may in one embodiment include the device 500. The device 500 includes a non-volatile memory 520, a data processing unit 510, and a read / write memory 550. The non-volatile memory 520 has a first memory portion 5 of a computer program, such as an operating system, is stored to control the operation of the device 500. Furthermore, the device 500 comprises a bus controller, a serial communication port, I / O means, an A / D converter, a time and date input and transfer unit, a trade calculator and an interrupt controller (not shown). The non-volatile memory 520 also has a second memory portion 540.

A computer program P is provided for determining cleaning needs regarding a particulate filter 265 of an engine 231 exhaust gas purification system from an ash occurrence point of view.

The computer program P may comprise routines for determining a matte on the accumulated ash deposit in said particle filter 265.

The computer program P may comprise routines for determining said mat on the basis of determined heat capacity C1, C2 of said particle filter 265 at at least two different states regarding accumulated ash occurrence.

The computer program P may include routines for determining a first value C1 of said heat capacity of said particulate filter 265 based on a first state including determined parameter values regarding exhaust mass flow MF1 from said engine 231 and a temperature difference particulate filter 265 and anticipated law ash occurrence.

The computer program P may comprise routines for determining a second value C2 of said heat capacity of said particle filter 265 based on the determination of said first value C1 of said heat capacity and a second condition including determined parameter values regarding exhaust mass flow MF2 from said engine T1 and a temperature 231. , T3-T2 with respect to exhaust gas temperature upstream and downstream, respectively, said particle filter 265 and expected higher ash occurrence relative to said first state. The computer program P may comprise routines for determining said mat on the basis of a comparison between the thus determined two values of said heat capacity C1, C2. This can be done by comparing an absolute difference between said first heat capacity C1 and said second heat capacity C2 with a predetermined value TH1. This can be done by comparing an absolute ratio between said first heat capacity C1 and said second heat capacity C2 with a predetermined value TH2.

The computer program P may comprise routines for determining said value C1, C2 at said heat capacity in connection with transient processes regarding exhaust gas temperature upstream of said particle filter 265; and / or - routines for determining said value C102 at said heat capacity when a determined absolute temperature difference with respect to exhaust temperature 26 upstream and downstream of said particle filter 265 exceeds a predetermined value THtemp.

The computer program P may comprise routines for determining said value C1, C2 at said heat capacity in connection with transient processes with respect to exhaust gas temperature downstream of said particle filter.

The computer program P may include routines for controlling regeneration of said particulate filter 265 regarding soot particles before said matte regarding accumulated ash deposit is determined.

The computer program P may include routines for predicting the need to remove ash from said particle filter 265 based on determining the development of said mat over time.

The computer program P may include routines for determining the need to remove accumulated ash from said particle filter 265 at a predetermined achieved value with respect to said mat; and - routines for, in the event of a determined need to remove accumulated ash from said particle filter 265, for an operator of said engine 231, indicating said need.

The program P can be stored in an executable manner or in a compressed manner in a memory 560 and / or in a read / write memory 550.

When it is described that the data processing unit 510 performs a certain function, it should be understood that the data processing unit 510 performs a certain part of the program which is stored in the memory 560, or a certain part of the program which is stored in the read / write memory 550.

The data processing device 510 can communicate with a data port 599 via a data bus 515. The non-volatile memory 520 is intended for communication with the data processing unit 510 via a data bus 512. The separate memory 27 560 is intended to communicate with the data processing unit 510 via a data bus 511. Read / the write memory 550 is arranged to communicate with the data processing unit 510 via a data bus 514. To the data port 599, e.g. the lanes L210, L220, L231, L233, L237, L277 are connected (see Figure 2).

When data is received on the data port 599, it is temporarily stored in the second memory part 540. Once the received input data has been temporarily stored, the data processing unit 510 is ready to perform code execution in a manner described above. According to one embodiment, signals received at the data port 599 include information on Parts of the methods described herein may be performed by the device 500 using the data processing unit 510 which runs the program stored in the memory 560 or the laser write memory 550. When the device 500 runs the program, the methods described are executed.

The foregoing description of the preferred embodiments of the present invention has been provided for the purpose of illustrating and describing the invention. It is not intended to be exhaustive or to limit the invention to the variations described. Obviously, many modifications and variations will occur to those skilled in the art. The embodiments were selected and described in order to best explain the principles of the invention and its practical applications, thereby enabling those skilled in the art to understand the invention in different embodiments and with the various modifications which are appropriate to the intended use. 28

Claims (16)

A method for determining the cleaning need for a particulate filter (265) of an engine (231) exhaust gas purification system from an ash occurrence point of view, comprising the step of: - determining a mat of ash accumulated in said particulate filter (265), characterized by the step of: 1. determining (s301; s340) said mat on the basis of a fixed heat capacity (C1; C2) of said particle filter (265) in at least two different states regarding accumulated ash occurrence. The method of claim 1, comprising the step of: 1. determining (s310) a first value (C1) of said heat capacity of said particulate filter (265) based on a first state including determined parameter values regarding exhaust mass flow (MF1) in said engine (231) and a temperature difference (T1-T2, T3- T2) with respect to exhaust gas temperature upstream and downstream said particle filter (265) and expected low ash occurrence; Determining (s320) a second value (C2) of said heat capacity of said particulate filter (265) based on the determination of said first value (C1) of said heat capacity and a second state including determined parameter values regarding exhaust mass flow (M F2) from said engine (231) and a temperature difference (T1-T2, 13-12) regarding exhaust gas temperature upstream and downstream of said particle filter (265) and expected higher ash occurrence relative to said first state; and 29 3. determine (s330, s340) said mat on the basis of a comparison between the two values (C1, C2) thus determined on said heat capacity. A method according to claim 1 or 2, comprising the step of: - determining (s310; s320) said value (C1; C2) of said heat capacity in connection with transient processes of upstream and / or downstream said particle filter (265); and / or 1. determining (s310; s320) said value (C1; C2) at said heat capacity when a determined absolute temperature difference with respect to exhaust gas temperature upstream and downstream of said particle filter (265) exceeds a predetermined value (THtemp). A method according to any one of the preceding claims, comprising the step of: 1. regenerating said particle filter (265) with respect to soot particles before said matte with respect to accumulated ash deposit is determined. A method according to any one of the preceding claims, comprising the step of: 1. predicting the need for removal of ash from said particle filter (265) based on determining the development of said mat over time. A method according to any one of the preceding claims, comprising the step of: 1. determining the need (s340) to remove accumulated ash from said particulate filter (265) at a hazardously determined value with respect to said mat; and 2. in the event of an established need to remove accumulated ash from said particulate filter, for an operator of said engine (231), present / indicate (s350) said need. A system for determining the cleaning requirement for a particulate filter (265) of an exhaust gas purification system of an engine (231) from the ash deposit point, comprising: 1. means (200; 210; 500) adapted to determine a mat of ash accumulated in said particulate filter (265), characterized by: 2. means (200; 210; 500) adapted to determine said mat on the basis of determined heat capacity (C1; C2) of said particle filter (265) at at least two different states regarding accumulated ash occurrence. A system according to claim 7, comprising: 1. means (200; 210; 500) adapted to determine a first value (C1) of said heat capacity of said particle filter (265) based on a first state including determined parameter values regarding exhaust mass flow (MF1) Iran named engine (231) and a temperature difference (T1-T2; T3-T2) regarding exhaust temperature upstream and downstream of said particulate filter (231) and expected layer of ash; Means (200; 210; 500) adapted to determine a second value (C2) of said heat capacity of said particulate filter (265) based on the determination of said first value (C1) of said heat capacity and a second state including determined parameter values regarding exhaust gas mass flow (MF2) from said engine (231) and a temperature difference 31 (T1-T2; T3-T2) regarding exhaust temperature upstream and downstream of said particle filter (265) and expected higher ash occurrence relative to said first condition; and 3. means (200; 210; 500) adapted to determine said mat on the basis of a comparison between the two values (C1, C2) thus determined on said heat capacity. A system according to claim 7 or 8, comprising: 1. means (200; 210; 500) adapted to determine said value (C1; C2) of said heat capacity in connection with transient processes regarding exhaust gas temperature upstream and / or downstream of said particle filter ( 265); and / or means (200; 210; 500) adapted to determine said value (C1; C2) at said heat capacity when a determined absolute temperature difference with respect to exhaust gas temperature upstream and downstream of said particle filter (265) exceeds a predetermined value (THtemp). A system according to any of claims 7-9, comprising: 1. means (200; 210; 500; 260) adapted to regenerate said particle filter 20 (265) with respect to soot particles before said mat with respect to accumulated ash deposit is determined. A system according to any of claims 7-10, comprising: 32 means (200; 210; 500) adapted to predict the need to remove ash from said particle filter (265) based on determining the development of said mat over time. A system according to any of claims 7-11, comprising: 1. means (200; 210; 500) adapted to determine the need to remove accumulated ash from said particle filter (265) at a predetermined achieved value with respect to said mat; and 2. means (200; 210; 500; 220) adapted to indicate to said operator of said engine, at an determined need to remove accumulated ash from said particulate filter (265), for an operator of said engine. A motor vehicle (100; 110) comprising a system according to any one of claims 712. A motor vehicle (100; 110) according to claim 13, wherein the motor vehicle is any of a truck, bus or passenger car. A computer program (P) in an exhaust gas purification system, wherein said computer program (P) comprises program code for causing an electronic control unit (200; 500) or a computer (210; 500) connected to the electronic control unit (200; 500) to perform the steps according to any one of claims 1-6. A computer program product comprising a program code stored on a computer readable medium for performing the method steps according to any one of claims 1-6, when said program code is crossed on an electronic control unit (200; 500) or a computer (210; 500) connected to the electronic control unit (200; 500). 2 2