FR2915770A1 - METHOD FOR MANAGING AN EXHAUST GAS TREATMENT DEVICE AND DEVICE FOR IMPLEMENTING THE METHOD - Google Patents

Abstract

A method of managing an exhaust cleaning device (14, 16, 18) installed in the exhaust gas system (12) of an internal combustion engine (10), requiring a reactive agent for the catalytic conversion of the nitrogen oxides NOx (NOx_vK) of the internal combustion engine (10) and whose dosing is carried out using a dosing signal (s_D) according to a real measured value d nitrogen oxide Nos (NOx_Mes) measured by NOx nitrogen oxide sensor (18) downstream of a catalyst (16) provided in the exhaust gas cleaning device (14, 16, 18) . The dosing signal (s_D) is influenced as a function of a measurement (h, km) of the operating time of the exhaust gas treatment device (14, 16, 18) in the direction of an increase in dosage. reactive agent by a correction signal (k_Sol).

Description

Field of the Invention The present invention relates to a method of

  managing an exhaust cleaning device installed in the exhaust system of an internal combustion engine, requiring a reactive agent for the catalytic conversion of nitrogen oxide emissions from the engine to internal combustion and whose metering is carried out using a dosing signal as a function of a real measured value of nitrogen oxides measured by a nitrogen oxide sensor downstream of a catalyst provided for in the exhaust gas cleaning device. The invention also relates to a device for implementing such a method. The invention also relates to a program for a control device and a program product for a control device. State of the art De 199 03 439 describes a method of managing an internal combustion engine whose exhaust gas system is equipped with a catalyst SCR (Selective Catalytic Reduction Catalyst) which reduces the oxides of nitrogen contained in the exhaust gas of the internal combustion engine with a reactive agent to obtain nitrogen. The dosage of the reactive agent or a component giving the reactive agent is preferably according to the operating parameters of the internal combustion engine such as, for example, the speed of rotation (engine speed) and the quantity of fuel injected, used. at least as a measure of the nitrogen oxides emitted by the internal combustion engine. In addition, the dosage is preferably based on the parameters of the exhaust gas such as, for example, the temperature of the exhaust gas and / or the operating temperature of the SCR catalyst. As the reactive agent, for example, reducing ammonia, originating from an aqueous solution of urea, is used as component giving the reactive agent. The dosage of the reagent must be carefully fixed. Too low a dosage results in an incomplete reduction of the nitrogen oxides. Too high a dosage results in a slippage of the reagent which results in an unnecessarily high consumption of reagent and which may also give off an unpleasant odor depending on the characteristics of the reagent. DE 10 2004 031 624 A1 discloses a method of managing an SCR catalyst used to clean the exhaust gases of an internal combustion engine in which control or regulation of the agent filling level is provided. reagent in the SCR catalyst according to a predefined storage setpoint. The setting of the storage set point ensures that in the non-stationary operating states of the internal combustion engine, a sufficient quantity of reactive agent will be available to respond as completely as possible to the raw emissions. NOx nitrogen oxides by the internal combustion engine and that on the other hand, it avoids to a very large extent any slippage of reagent. The level of reactive agent filling in the SCR catalyst is determined by means of a catalyst model which takes into account the mass flow rate of nitrogen oxides NOx arriving on the SCR catalyst, the mass flow rate of oxides. NOx nitrogen leaving the catalyst SCR, the catalyst temperature and optionally the slip of reagent. The maximum possible filling level of the reactive agent of the SCR catalyst depends in particular on the operating temperature of the catalyst, which temperature is highest for the low operating temperatures and which falls to lower values as the operating temperature increases. . The efficiency of the SCR catalyst depends on the catalytic activity which is lower at low operating temperatures and which passes through a maximum as the operating temperature increases to fall back again as the operating temperature continues to increase.

  Document DE 10 2005 042 489 A1 (not previously published) describes a method of managing an internal combustion engine whose exhaust system is equipped with a SCR catalyst receiving a reactive agent participating in the conversion. nitrogen oxides NOx. Downstream of the catalyst, the concentration of nitrogen oxide NOx is measured using a NOx nitrogen oxide sensor having a transverse sensitivity vis-à-vis the reactive agent which is, for example, 'ammonia. The concentration measured in NOx nitrogen oxides is compared to the calculated concentration of NOx nitrogen oxides. According to the difference, the dosage of the reactive agent is involved. A plausibility check is provided by which the amount of reagent dosed over a predetermined period of time is compared with the amount of reactant converted in the SCR catalyst and / or the amount of NOx oxides converted. Since the NOx nitrogen oxide sensor has a transverse sensitivity towards the reactive agent, when a difference is observed, it is impossible to distinguish without more whether one is in the presence of an overdose or a sub-assay of reagent so that a plausibility check is provided to obtain information on the correction on the assay. DE 10 2006 041 676 A1 (not previously published) discloses an analogous method in which a comparison is also made of the difference between a measured concentration and a calculated concentration of nitrogen oxides NOx downstream of an SCR catalyst and a difference threshold value. If a difference threshold value is exceeded, a measure is taken to lower or complete the lack of dosage. Then, check the difference by measuring the increase and if the difference exceeds the measurement of the increase, take a measurement to increase the dosage. Document DE 10 2005 042 490 A1 (not previously published) also describes a method of managing an internal combustion engine, the exhaust system of which comprises at least one SCR catalyst receiving a reactive agent participating in the conversion. nitrogen oxides NOx. A plausibility check is provided for the difference obtained between the measured value of the concentration of nitrogen oxides NOx downstream of the catalyst and a calculated measurement. It is assumed that the NOx nitrogen oxide sensor has a transverse sensitivity to the reactive agent. The differences obtained are exploited each time. Depending on the results of the operation, one intervenes on the fixing of the signal of reactive agent. With the aid of the measures described, a long-term adaptation of the reactive agent signal is carried out. DE 10 2005 042 487 A1 (not previously published) describes a similar procedure that also calculates a measurement of the concentration of nitrogen oxides produced downstream of the catalyst and is measured with a NOx nitrogen oxide sensor. with transverse sensitivity vis-à-vis the reactive agent. The starting point is a regulation of the level of reactive agent filling in the SCR catalyst with respect to a set point value. A plausibility check of the sensor signal can be made by slightly overdosing the reagent from a possible maximum fill level to the reagent. In this state of operation of the catalyst, it can be assumed that the NOx nitrogen oxide sensor captures the slip as a reactive agent. By an intervention on the reference filling level of the reactive agent in the catalyst as a function of the difference determined between the measured concentration and the calculated concentration of NOx nitrogen oxides, a short (short term) adaptation can be realized. dosage that corresponds to a brief adaptation. NOx nitrogen oxide sensors currently available have tolerances to the accuracy of the measurement which can influence the result of the measurements taking into account the ever stricter regulations concerning the gases of exhaust. In particular, it must be assumed that the NOx nitrogen oxide sensors exhibit a long-term drift influencing the measurement result.

  In addition or alternatively, the drift of a NOx nitrogen oxide sensor, it is possible to have a drift of the device for introducing the reactive agent and / or an aging of a catalyst and / or a modification. emissions of NOx nitrogen oxides by an internal combustion engine that no longer meets a pre-defined minimum conversion of nitrogen oxides NOx by the exhaust gas treatment device. OBJECT OF THE INVENTION The object of the present invention is to develop a process for managing an exhaust gas treatment device as well as a device for carrying out this method making it possible to ensure, during the entire operating time of the exhaust gas treatment device, a predefined minimum conversion rate for nitrogen oxides NOx. DESCRIPTION AND ADVANTAGES OF THE INVENTION For this purpose, the invention relates to a method of the type defined above, characterized in that the dosing signal is influenced according to a measurement of the operating time of the treatment device of the exhaust gas in the direction of increasing the reagent dosage by a correction signal.

  The means of the process of the invention guarantee the required minimum conversion of NOx nitrogen oxides throughout the operating life of the exhaust gas treatment device. It will also be possible to compensate for any drift, in particular a long-term drift of the NOx nitrogen oxide sensor and / or the device for introducing the reactive agent and / or the catalyst and / or a variation of the oxide emissions. NOx nitrogen of the internal combustion engine by the means of the invention. The correction signal is set in a range of values which guarantees, on the one hand, an always sufficient dosage of the reagent and, on the other hand, avoids excessive sliding of the reagent agent by overdosing. The method according to the invention is based on the consideration that as a result of the tolerances and drifts of the various components of the exhaust gas treatment device and / or the variations of NOx nitrogen oxide emissions of a combustion engine internally, even for a NOx nitrogen oxide sensor operating with the specific accuracy, there may be insufficient conversion of nitrogen oxides NOx in the exhaust gas treatment device. When starting the exhaust gas treatment system, tolerances can be taken into account in the application. During the subsequent operation of the exhaust gas treatment device, it will no longer be simply possible to make such an intervention to compensate for drifts. The process according to the invention provides in tendency a slight overdose of reactive agent in order to always be able to respect the predetermined minimum conversion rate of NOx nitrogen oxides. Such unnecessary overdose of the reactive agent does not need to be taken into account, however, since the nitrogen oxide sensor NOx, in case of any overdose of reagent, because of its transverse sensitivity to the reagent, provides a sensor signal that opposes overdose in the case of regulation or adaptation. The short slip peaks of the reagent are recorded by a NO x nitrogen oxide sensor with tolerances. According to a development, the dosing signal is previously controlled and regulated. The preliminary control is done for example using the calculated filling level of reactive agent in the catalyst. The level of reactive agent filling is advantageously determined using a catalyst model. The catalyst model preferably takes into account at least the catalyst temperature and a mass flow measurement of NOx nitrogen oxides. According to a development, it is regulated according to the difference between a measured measurement of the concentration of nitrogen oxides NOx and a reference value of NOx nitrogen oxides. The difference obtained is preferably used to influence the calculated level of filling of the reactant in the catalyst. A development provides a brief (short term) adaptation to the catalyst model for calculating the level of reactant fill in the catalyst. Alternatively or additionally, a long-term adaptation is preferably provided, which in particular corrects a control variable from which the assay signal is collected. A development provides that as a measure of the operating performance of the NOx nitrogen oxide sensor, the kilometers traveled by the vehicle driven by the internal combustion engine are used. The correction signal is preferably set to a value range of between 1.0 and 1.2 which makes it possible to use the correction signal for a multiplicative combination. The device according to the invention for the implementation of the method comprises a control apparatus for executing the method in particular.

  The control apparatus preferably comprises at least one electrical memory containing the process steps in the form of a control unit program. The control device program according to the invention provides for carrying out all the steps of the method according to the invention when the program is executed on a control device. The control device program product according to the invention is compared to a program code recorded on a medium that can be read by a machine and that executes the method according to the invention when the program is executed in a control device. Drawings The present invention will be described hereinafter in more detail with the aid of exemplary embodiments shown in the accompanying drawings in which: FIG. 1 shows the technical environment in which the process of the invention is carried out; FIG. 2 shows the relationship between a dosing signal and a NOx concentration downstream of a catalyst or the relationship between the dosing signal and a slip of reactive agent.

  DESCRIPTION OF EMBODIMENTS FIG. 1 shows an internal combustion engine 10 whose exhaust system 12 is equipped with a reagent introduction device 14 and at least one catalyst 16. In the system exhaust gases 12, NOx_vK nitrogen oxide emissions from the combustion engine 10 as well as NOx_nk nitrogen oxide concentrations downstream of the catalyst 16. Downstream of the catalyst 16 is a sensor of nitrogen oxides NOx 18 which supplies to a control apparatus 20 a measurement of the concentration of nitrogen oxides NOx_nk and the value of the actual value of nitrogen oxides NOx Mes. The reactive agent introduction device 14, the catalyst 16 as well as the nitrogen oxide sensor NOx 18 in combination with an exhaust gas treatment device 14, 16, 18. control 20 provides a dosing signal s_D to the reagent dosing device 14.

  The internal combustion engine 10 emits exhaust gas containing NOx_vK nitrogen oxide emissions. The NOx nitrogen oxide parts in the exhaust gas must be converted in the catalyst 16 into less harmful components of the exhaust gas. For this, the catalyst 16 is preferably made in the form of an SCR catalyst which requires a reactive agent, for example ammonia for the conversion. The reactive agent or a prior state of the reactive agent, for example an aqueous solution of urea, is introduced by the reagent introduction device 14 preferably directly into the exhaust system 12 upstream. The metered amount is set by the dosing signal s_D provided by the control apparatus 20 as a function of at least one measurement of the internal combustion engine 10 of NOx_vK nitrogen oxide emissions.

Such a measure of the nitrogen oxide emission NOx_vK is calculated, for example, instead of a direct measurement, preferably using, for example, at least one operating parameter of the internal combustion engine 10, for example its rotational speed and / or a fuel signal.

In the embodiment shown, it is assumed that the dosing signal s_D is set in the case of a pre-command contained in a control means 30. It is furthermore assumed that the pre-control or the regulation of the dosing signal s_D on the basis of the level of reactive agent filling in the catalyst 16 which is fixed by means of a reference value of the filling level of Fül_Sol reactive agent. Since the actual value of the reagent filling level is not directly accessible by measurement techniques, the actual value of the reagent replenishing level must be provided as a true level value. Fül_Sim reagent filling agent. The calculation is carried out using a catalyst model 32 which receives, for example, the temperature of the catalyst 16, the nitrogen oxide emissions NOx_vK and the dosing signal s_D. The catalyst model 32 and the calculation of the level of reactive agent filling in the catalyst 16 can be done according to the state of the art presented in detail in the preamble. The pre-control in the regulation 30 sets a control variable s according to the difference between the set value of the Fül_Sol reagent filling level and the actual value of the calculated Fül_Sim reagent filling level. The control variable s will become after application of a signal correction 34, the dosing signal s_D. Since there is no actual reaction for the actual value of the reactive agent filling level, in place of a control as a function of the set value of the Fül_Sol reagent level, a pre-order. The pre-control is superimposed on a control that is able to compensate for the tolerances and drifts of the components. In the embodiment shown, it is assumed that the regulation is based on the concentration of nitrogen oxides NOx_nk which occurs downstream of the catalyst 16; the NOx nitrogen oxide sensor 18 provides this information to the control apparatus 20 as a true value of NOx_Mes nitrogen oxides; the real value of the NOx_Mes nitrogen oxides is at least one measurement of the concentration of NOx_nk nitrogen oxides that exists downstream of the catalyst 16. In the exemplary embodiment, it is assumed that the regulation is based on a variation of the level It is furthermore assumed that the regulation takes into account the difference d between the actual value of the NOx_Mes nitrogen oxides and the set point of the reactive agent filling level Fül. Ground. One embodiment provides a short-term adaptation (short adaptation) which depends for example on the difference d and thus provides a short adaptation signal Adapt_k_ti. The short adaptation signal Adapt_k_ti is determined in the short-term adaptation signal determination means 38 as a function of the difference d to be provided as a short adaptation signal Adapt_k_ti for example to the catalyst model 32; thus a variation of the actual value of the calculated reactive agent filling level Fül_Sim can be taken in the short term in the setting of the dosing signal s_D. This makes it possible to re-act in the short term both to respond to insufficient dosage or excessive dosage. Another alternative or alternative embodiment provides a long-term adaptation which provides a long adaptation signal Adapt_L_ti. The adaptation long signal Adapt_L_ti is determined by a long-term adaptation signal determining means 40 as a function of the difference d to be used for example as a long adaptation signal Adapt_L_ti in the signal correction means 34 for correct the adjustment quantity s. The signal correction 34 then supplies the dosing signal s_D. It is assumed that the NOx nitrogen oxide sensor 18 has a transverse sensitivity to the reactive agent. This means that first of all it will not be possible to distinguish between a too low dosage of the reagent and the consequence that the concentration of NOx_nk nitrogen oxides increases and consequently the dosage of reagent agent is too high. so that there is a slip of reagent NH3. FIG. 2 qualitatively shows the relation between the dosing signal s_D and the concentration of nitrogen oxides NOx_nk and secondly between the dosing signal s_D and the sliding of reactive agent NH3. The actual value of nitrogen oxides NOx_Mes goes through a minimum when going from a too low dosage to an excessive dosage. The dosage of the reactive agent is preferably ensured by the dosing signal s_D so as to have at the same time a concentration of nitrogen oxides NOx_nk as minimal as possible and a slip of NH3 reactive agent as reduced as possible. FIG. 2 shows a start-of-dosing signal s_D_St which must be available at start-up of the nitrogen oxide sensor NOx 18 if the reactive agent filling level is at the set point level. filling reagent Fül_Sol and if at the same time the actual value of NOx_Mes nitrogen oxides and the set value of Fül_Sol reagent level filling level correspond. During the operation of the internal combustion engine 10 or the exhaust gas treatment device 14, 16, 18, it can not be ruled out that the nitrogen oxide sensor NOx 18 undergoes signal drift having as its Consequently, the actual value of the nitrogen oxides NOx Mes no longer corresponds to the concentration of NOx_nK effective nitrogen oxides. In addition, it is necessary to take into account a drift of the other components 14, 16 of the exhaust gas treatment device 14, 16, 18. The reactive agent introduction device 14 which comprises many mechanical components can undergo a drift so that the metered amount of reagent differs from the predefined amount by the s_D assay signal. In addition, the catalyst 16 over-aging so that for example as aging increases, it will require more reactive agent. It must also be taken into account that the emissions of nitrogen oxides NOx by the internal combustion engine 10 are drifting in the long term. In order to ensure that a nitrogen oxide concentration NOx_nk is kept as low as possible during the entire operating life of the exhaust gas treatment device 14, 16, 18, it is intended to increase the dosage of the reactive agent according to the increase of the operating time of the exhaust gas treatment device 14, 16, 18. The operating time of the exhaust gas treatment device 14, 16, 18 corresponds to generally speaking to the operating time of the entire system including the operating time of the internal combustion engine 10. In the following, reference will only be made to the operating time of the gas treatment device. exhaust 14, 16, 18.

The dosing signal s_D is influenced by a measurement of the operating time of the exhaust gas treatment device 14, 16, 18 in the direction of increasing the dosage of the reagent by a correction signal k_Sol . The correction signal k_Sol is supplied by a means for determining the correction signal 42 according to the operating time of the exhaust gas treatment device 14, 16, 18. At the start of the treatment device of the exhaust gas treatment device 14, 16, 18. Exhaust gas 14, 16, 18, the correction signal k_Sol is preferably set to the start value k_St of the correction signal equal to 1. This gives the starting value of the dosing signal s_D_St. The variations of the corrective signal k_Sol are for example according to the operating hours h of the exhaust gas treatment device 14, 16, 18. Insofar as the internal combustion engine 10 drives a motor vehicle, can be used as a measure of the operating time of the exhaust gas treatment device 14, 16, 18 not only hours of operation of the internal combustion engine 10 and also the distance traveled by the vehicle measured in km. The correction signal k_Sol is taken into account in the setpoint correction means 44 which combines the setpoint value of the nitrogen oxides NOx_Sol with the setpoint correction signal k_Sol and a setpoint value of the oxides of nitrogen. NOx_Sol nitrogen, corrected. The combination is preferably by multiplication so that at the beginning of the operating time of the exhaust gas treatment device 14, 16, 18, there is no correction and the correction is done progressive as a function of the increase in the operating time of the exhaust gas treatment device 14, 16, 18, which results in a tendency to increase the dosage of reactive agent. The corrected set value of nitrogen oxides NOx_k_Sol is applied to an adder 46 which determines the difference between the corrected setpoint of the corrected nitrogen oxides NOx_k_Sol and the actual value of the nitrogen oxides NOx Mes to give the difference between . the difference d intervenes in the regulation 30 or in the preliminary control, for example by increasing the set value of the filling level of the reagent Fül_Sol and influences the control variable s. An increase in the adjusted nitrogen oxide NOx_k_Sol set point results in an increase of the control variable s and thus an increase of the s_D do-wise signal. The increase in the reagent dosage is indicated symmetrically in FIG. 2 by the arrow 50. Influence the dosing signal s_D in the direction of an increase in dosage as a function of the increase in the operating time of the device for treating the exhaust gases 14, 16, 18 first of all ensures that in the event of drift of the nitrogen oxide sensor NOx 18 for which the actual value of the nitrogen oxides NOx_Mes, measured, is lower than the concentration of NOx_nk effective nitrogen oxides, nevertheless gives a sufficient dosage of reagent to comply with a minimum conversion rate of nitrogen oxides NOx. In the event of drift of NOx 18 nitrogen oxide sensor, if the actual value of nitrogen oxides NOx_Mes, measured is greater than the concentration of NOx_nk effective nitrogen oxides, there is no need for ensuring, as a function of the increase in the service life of the exhaust gas treatment device 14, 16, 18, a greater slip of reagent NH3 since, as the nitrogen oxide sensor NOx 18 has a cross sensitivity vis-à-vis the reactive agent, it can compensate overdose by regulation. The means according to the invention nevertheless makes it possible to also respect a predefined conversion rate, minimum NOx nitrogen oxides if the NOx nitrogen oxide sensor 18 operates within the allowed tolerances range and if there is nevertheless a drift in the other components 14, 16 of the exhaust gas treatment device 14, 16, 18 and / or a modification of NOx nitrogen oxide emissions by the internal combustion engine 10. Also in this case, Without the means provided by the invention, it would not be possible even for a properly functioning NOx 18 nitrogen oxide sensor to meet the predefined conversion rate of the NOx nitrogen oxides. . Overall, thanks to the means of the invention (a reactive agent overdose which corresponds to the trends in the operating time of the exhaust gas treatment device 14, 16, 18) makes it possible to compensate for a weakness in the the entire system from the point of view of insufficient dosage of reagent and that because of the robustness of the entire system vis-à-vis a reactive agent overdose, we can take into account an unnecessary overdose because even if a tolerant NOx 18 nitrogen oxide sensor records a brief passage of a reagent peak because of its transverse sensitivity to the reagent. The range of values in which the setpoint correction signal k_Sol must be located can be fixed by an evaluation of predictable drifts. The range of values is, for example, between 1 and 1.2. The value 1 corresponds to the value at the time of putting into operation of the exhaust gas treatment device 14, 16, 18; the value 1.2 corresponds to that of the highest expected operating time for the exhaust gas treatment device 14, 16, 18. It is assumed for this that the value 1 does not influence the set point value. nitrogen oxides NOx_Sol on the corrected setpoint of the nitrogen oxides NOx_k_Sol, so that the dosage of reagent increases as a function of the increase in the operating time h, km of the gas treatment device. exhaust 14, 16, 18 or lo the operating time of the entire system including the internal combustion engine 10. 15

Claims (6)

  1) A method of managing an exhaust gas cleaning device (14, 16, 18) installed in the exhaust gas system (12) of an internal combustion engine (10), requiring a reactive agent for the catalytic conversion of the nitrogen oxides NOx (NOx_vK) of the internal combustion engine (10) and whose dosing is done using a dosing signal (s_D) according to a variable their actual measured nitrogen oxides Nos (NOx Mes) measured by a NOx nitrogen oxide sensor (18) downstream of a catalyst (16) provided in the exhaust gas cleaning device (14). , 16, 18), characterized in that the dosing signal (s_D) is influenced as a function of a measurement (h, km) of the operating time of the exhaust gas treatment device (14, 16, 18 ) in the direction of increasing the reagent dosage by a correction signal (k_Sol). 2) Method according to claim 1, characterized in that the dosing signal (s_D) is previously controlled and is regulated. 3) Method according to claim 2, characterized in that the dosing signal (s_D) is previously controlled by means of a calculated real value of the filling level of reactive agent (Fül_Sim) in the catalyst (16). . 4) Process according to claim 3, characterized in that the calculated actual value of the reactive agent filling level (Fül_Sim) is calculated using a catalyst model (32) which takes into account at least the temperature (te Kat) of the catalyst as well as a measurement of the emissions of nitrogen oxides (NOx_vK) of the internal combustion engine (10). 5) Process according to claim 2, characterized by the fact that the difference (d) between the actual value of the nitrogen oxides NOx (NOx Mes) and a reference value of the nitrogen oxides NOx is regulated. (NOx_Sol). 6) Process according to claim 5, characterized in that the difference (d) influences the actual calculated value of the level of filler-wise reagent (Fül_Sim). 7) A process according to any one of claims 2 or 5, characterized by a brief adaptation which occurs in the catalyst model (32) for the calculation of the actual value of the reactive agent filling level (Fül_Sim) in the catalyst (16) with a short adaptation signal (Adapt_K_ti). 8) A method according to any one of claims 2 or 5, characterized by a long-term adaptation which corrects an adjustment variable (s) for the dosing signal (s D) with a long-term adaptation signal ( Adapt_L_ti). 9) Process according to claim 5, characterized in that the correction signal (k_Sol) corrects the nitrogen oxides NOx setpoint (NOx_Sol). 10) Method according to claim 3, characterized in that the correction signal (k_Sol) corrects a reference value of the reactive agent filling level (Fül_Sol). 11) The method according to claim 1, characterized in that as a measure (h, km) of the operating time of the exhaust gas treatment device (14, 16, 18), the run-through (km) is used. ) by a vehicle driven by the internal combustion engine (10). 12) Method according to claim 1, characterized in that the correction signal (k Sol) starts with the value 1 and increases up to the value 1.2. 13) Device for managing an exhaust gas treatment device (14, 16, 18) installed in the exhaust gas system (12) of an internal combustion engine (10), and which requires a reagent for catalytic catalytic conversion of nitrogen oxides NOx (NOx_vK) emitted by the internal combustion engine (10), the determination of the reagent being made with a dosing signal (s D) as a function of the actual measured value of nitrogen oxides NOx (NOx Mes) by a NOx nitrogen oxide sensor (18) installed in the exhaust gas treatment device (14, 16, 18) downstream catalyst (16) forming part of the exhaust gas treatment device (14, 16, 18), characterized in that it comprises at least one apparatus (20) specially constructed for carrying out the process according to any one of Claims 1 to 12. 14) Control device program executing all the steps of the method according to the any one of claims 1 to 12 when the program is executed by a control apparatus (20). 15) A control apparatus program product having program codes recorded on a machine-readable medium for carrying out the method according to any one of claims 1 to 12 when the program is executed in a control apparatus. control (20). 35