Engine data processor and computer-implemented method for adjusting an exhaust gas composition

Abstract

Engine data processor (1) for adjusting an exhaust gas composition (25) for an internal combustion engine, wherein the engine data processor (1) is configured to receive a geometric characteristic (10) of a discharge unit (11) through which the exhaust gas composition (25) can be discharged, and to determine a smoke visibility limit (21,3) from this, to receive filter fill state information (20) of an exhaust gas filter (16) designed to filter the exhaust gas composition (25), to receive a mean catalyst temperature (22) of an exhaust gas catalyst (18) designed to catalyze the exhaust gas composition (25), and to determine a nitrogen dioxide conversion rate (12) as a function of the filter fill state information (20) and the mean catalyst temperature (22), and to determine the nitrogen dioxide conversion rate (12) and the smoke visibility limit (21,3) to compare them with each other and to determine a control variable (5) for the internal combustion engine such that the exhaust gas composition (25) is invisible, and to output the control variable (5).

Description

[0001] The present invention relates to an engine data processor according to independent claim 1. Furthermore, it relates to a computer-implemented method for adjusting an exhaust gas composition according to independent claim 12.

[0002] Internal combustion engines are often equipped with control systems. These are used to receive and evaluate sensor data, process it using algorithms, and then determine and output manipulated variables. The manipulated variables output by a control system usually serve the purpose of operating various actuators of the internal combustion engine within safe limit ranges. These limit ranges can, for example, define a permissible temperature range or a permissible pressure range.

[0003] Internal combustion engines are used in vehicles as propulsion systems or in buildings in combination with a generator as a power generator. In an internal combustion engine, fuel is burned, producing mechanical power. This power can be used to drive a vehicle or a generator.

[0004] Internal combustion engines must be operated in such a way that legal emissions standards are met. A legal emissions standard often includes a limit for the maximum amount of nitrogen oxide that may be emitted as exhaust gas from the internal combustion engine. Such a limit is usually preferably stored in the internal combustion engine control system. During operation, several sensors monitor the condition of the internal combustion engine. The internal combustion engine control system evaluates the state variables and uses these to calculate several manipulated variables that can be used to operate actuators that are part of the internal combustion engine. The internal combustion engine can therefore provide the mechanical power for which it was designed, be in a safe condition at all times, and comply with a legal emissions standard.

[0005] An internal combustion engine of the type mentioned above is designed to monitor the amount of nitrogen oxide emitted and to comply with the emission specifications regarding the maximum permissible amount of nitrogen oxide.

[0006] One disadvantage for operators of conventional internal combustion engines is that they can emit visible smoke, even if they comply with all legal emissions requirements. Visible smoke emitted by an internal combustion engine is more likely to contaminate and stain the surfaces of objects or components located near the engine. Therefore, internal combustion engines that emit visible smoke are becoming undesirable for an increasing number of operators.

[0007] The invention is based on the object of enabling cost-effective, safe, and clean internal combustion engine operation that generates no visible smoke. In particular, an improved internal combustion engine is to be provided that complies with all legal emissions regulations and does not emit visible, yellow smoke induced by nitrogen dioxide.

[0008] The object is achieved with an engine data processor according to independent claim 1.

[0009] An engine data processor according to the invention for an internal combustion engine serves to adjust an exiting exhaust gas composition. The exhaust gas composition includes a quantity of nitrogen oxide. For example, the exhaust gas composition exits an internal combustion engine or an exhaust gas aftertreatment system connected to an engine. In particular, the engine data processor serves to adjust the quantity of nitrogen dioxide in the exhaust gas composition.

[0010] The engine data processor is configured to receive a geometric characteristic of a discharge unit through which the exhaust gas composition can be discharged and to determine a smoke visibility threshold therefrom. The discharge unit can be assigned to the internal combustion engine or be part of an exhaust aftertreatment system separate from the internal combustion engine.

[0011] The smoke visibility limit is a nitrogen dioxide limit value at which no visible smoke is emitted from the exhaust unit, but above which visible smoke is to be expected. This limit can be determined, for example, using a lookup table that compiles values ​​of a quantity, such as a nitrogen oxide emission value, with corresponding values ​​of the geometric characteristic.

[0012] For example, the smoke visibility limit is a nitrogen dioxide limit that the exhaust gas composition should not exceed in order to remain invisible. Alternatively, the smoke visibility limit is a nitrogen dioxide limit that may include the exhaust gas composition in order to remain invisible, but exceeding which leads to the exhaust gas composition becoming visible.

[0013] The exhaust unit is designed, for example, as a cylindrical chimney. A cylindrical chimney offers a flow geometry that protects the exhaust gas composition and is gentle on the machine.

[0014] The geometric characteristics of the exhaust unit include, for example, the diameter of the exhaust unit, the cross-sectional area of ​​the exhaust unit, or the radius of the exhaust unit. In particular, the diameter of the exhaust unit has been shown to be a geometric parameter that has a significant influence on the visibility of the exhaust gas composition, but this value is generally different in every plant using an internal combustion engine.

[0015] Furthermore, the engine data processor is configured to receive filter fill status information from an exhaust filter configured to filter the exhaust gas composition. The filter fill status information indicates the fill status of the exhaust filter, which may be, for example, empty, slightly filled, or filled.

[0016] Advantageously, the engine data processor is configured to receive filter fill level information from an exhaust gas filter configured to filter the exhaust gas composition and to determine a series of nitrogen conversion rates depending on the filter fill level information. A nitrogen dioxide conversion rate indicates the value of a quantity of nitrogen dioxide in the exhaust gas composition. The series of nitrogen dioxide conversion rates indicates the values ​​that the quantity of nitrogen dioxide in the exhaust gas composition can assume when the exhaust gas composition is filtered at a filter fill level according to the received filter fill level information.

[0017] The engine data processor is further configured to receive an average catalyst temperature of an exhaust gas catalyst configured to catalyze the exhaust gas composition and to determine a nitrogen dioxide conversion rate depending on the received filter fill state information and the average catalyst temperature.

[0018] Advantageously, the engine data processor is configured to determine a nitrogen dioxide conversion rate from the determined series of nitrogen dioxide conversion rates depending on the received mean catalyst temperature.

[0019] The nitrogen dioxide conversion rate, determined as a function of the average catalyst temperature and the filter filling state information, indicates the value of the amount of nitrogen dioxide present in the exhaust gas composition, which it assumes after catalysis in the exhaust gas catalyst when the average catalyst temperature is present and after filtration in the exhaust gas filter when the detected filter filling state is present: Taking into account the average catalyst temperature and the filter filling state enables a precise determination of the nitrogen dioxide conversion rate.

[0020] The engine data processor is configured to compare the calculated nitrogen dioxide conversion rate and the smoke visibility limit and to determine therefrom a control variable for the internal combustion engine such that the exhaust gas composition is invisible and to output the control variable.

[0021] By incorporating the geometric characteristics of the exhaust unit into the determination of the control variable for internal combustion engine operation, an important, customer-specific operating attribute is taken into account to achieve a permanently invisible exhaust gas composition. By taking the geometric characteristics into account, each engine data processor can be adjusted depending on the installation conditions of the corresponding internal combustion engine, enabling clean and cost-effective internal combustion engine operation with a pollution-free and invisible exhaust gas composition, regardless of the internal combustion engine installation space.

[0022] The solution according to the invention can be improved by various embodiments, each advantageous in itself and combinable with one another as desired. These embodiments and the associated advantages are discussed below. The advantages described with regard to the engine data processor and the internal combustion engine also apply to the computer-implemented method according to the invention, and vice versa.

[0023] In a first embodiment, the engine data processor is configured to receive a nitrogen oxide emission value detected at the exhaust unit and a exhaust unit pressure value and to determine the smoke visibility limit therefrom. Taking these state variables into account at the exhaust unit enables a more precise determination of the smoke visibility limit.

[0024] Advantageously, the engine data processor is configured to receive a filter pressure value of the exhaust filter and the exhaust unit pressure value, and to determine the filter condition information from the exhaust unit pressure value and the filter pressure value. Using the filter pressure value and the exhaust unit pressure value enables a precise determination of the filter condition information in real time, which enables a more accurate determination of the nitrogen dioxide conversion rate.

[0025] In a further embodiment, the engine data processor is configured to receive a filter temperature and a catalyst temperature and to measure the average catalyst temperature therefrom. This enables the determination of a more accurate average catalyst temperature and, consequently, also a more accurate determination of the nitrogen dioxide conversion rate.

[0026] Preferably, the engine data processor is configured to suppress yellow smoke and is further configured to determine at least one smoke visibility threshold configured as a yellow smoke visibility threshold and to determine the control variable for an internal combustion engine such that the generation of yellow smoke is suppressed. Yellow smoke is a type of visible smoke that frequently occurs during the operation of internal combustion engines.

[0027] Preferably, the engine data processor comprises a conversion unit configured to calculate a series of increased or decreased nitrogen conversion rates depending on the filter fill level information. Advantageously, the engine data processor comprises a conversion unit configured to calculate lower nitrogen conversion rates as the exhaust filter fill level increases. This enables continuous adjustment of the calculated nitrogen conversion rates to the currently determined filter fill level and contributes to a more accurate determination of the nitrogen dioxide conversion rate.

[0028] In an advantageous embodiment, the engine data processor comprises a model-predictive controller, wherein the model-predictive controller comprises a limiting unit configured to receive the nitrogen dioxide conversion rate and the smoke visibility limit and to use them to create an operating limit for setting an invisible exhaust gas composition for the internal combustion engine. This enables cost-optimized internal combustion engine operation while simultaneously avoiding visible smoke.

[0029] The object underlying the invention can also be achieved by an internal combustion engine, wherein the internal combustion engine comprises an engine data processor according to one of the above embodiments, an engine for providing mechanical power and an exhaust gas aftertreatment system which comprises the exhaust gas catalyst and the exhaust gas filter.

[0030] Thanks to the described features of the engine data processor, the internal combustion engine according to the invention can be operated with optimal operating costs and without visible smoke. In particular, the adjustment of the exhaust gas composition, taking into account the engine installation space and the geometric characteristics of the exhaust unit, can advantageously be carried out entirely within the engine data processor and thus internally within the internal combustion engine.

[0031] In an advantageous embodiment, the model-predictive controller is designed to generate optimal controller specifications for adjusting the average catalyst temperature from the operating limit. This enables the creation of commands with which the detected average catalyst temperature can be actively influenced, enabling not only the invisible exhaust gas composition but also cost-optimized operation of the internal combustion engine.

[0032] Preferably, the internal combustion engine comprises an actuator controller configured to receive the optimal operating controller specifications and to determine the manipulated variable for an actuation group of the engine therefrom. The manipulated variable is, for example, commands to activate an actuation group configured as valves in the engine for a specific duration and in a specific sequence such that a specific engine exhaust temperature can be set for cost-optimized influencing of the average catalyst temperature. This makes it possible to use the engine exhaust temperature to influence the average catalyst temperature, thus enabling cost-effective operation of the internal combustion engine.

[0033] The object underlying the above can further be achieved by a computer-implemented method according to independent claim 12.

[0034] A computer-implemented method for adjusting a filtered and catalyzed exhaust gas composition at an exhaust unit of an internal combustion engine comprises the following steps: Receiving a geometric characteristic of the discharge unit, determining a smoke visibility limit from the geometric characteristic, receiving an average catalyst temperature and filter filling state information and determining a nitrogen dioxide conversion rate as a function of the catalyst temperature and the filter filling state information, comparing the determined smoke visibility limit with the nitrogen dioxide conversion rate and, determining a manipulated variable with which the internal combustion engine is operated such that the exhaust gas composition to be discharged at the discharge unit is invisible.

[0035] The method is advantageous because it enables cost-effective internal combustion engine operation without visible smoke. Considering the geometric characteristics of the exhaust unit allows for precise determination of the control variables and flexible adaptation of the method to exhaust units with different geometric characteristics. Considering the average catalyst temperature and filter fill level information increases the accuracy of adjusting the exhaust gas composition.

[0036] The invention is explained in more detail below by way of example with reference to the drawings. The combination of features presented as examples in the embodiments shown can be supplemented by further features in accordance with the above explanations, depending on the properties of the engine data processor according to the invention and / or internal combustion engine according to the invention required for a specific application. Furthermore, in accordance with the above explanations, individual features can be omitted from the described embodiments if the effect of this feature is not important in a specific application.

[0037] In the drawings, the same reference symbols are always used for elements with the same function and / or structure.

[0038] They show: Fig. 1 : a schematic representation of an engine data processor according to an exemplary embodiment; Fig. 2 : a schematic representation of an internal combustion engine according to an exemplary embodiment; Fig. 3 : a representation of two different filter filling states and the dependent determination of a series of nitrogen dioxide conversion rates; and Fig. 4 : a schematic representation of a computer-implemented method according to an exemplary embodiment.

[0039] In the following, an engine data processor 1 according to the invention is described with reference to Fig. 1 Furthermore, an internal combustion engine 30 according to the invention is described with reference to Fig. 2 and a method 100 according to the invention based on Fig. 4 described.

[0040] In Fig. 1 A simplified, schematic representation of the engine data processor 1 is shown. The engine data processor 1 can have a standalone processor board 6 and / or be integrated into a board of the internal combustion engine 30 (not shown). The units, blocks, and modules of the engine data processor 1 described below can each be implemented in hardware, software, or a combination of both.

[0041] The engine data processor 1 is provided for adjusting an exiting exhaust gas composition 25 for an internal combustion engine. The exhaust gas composition 25 comprises a quantity of nitrogen oxide and exits an engine 19 or a discharge unit 11 of an exhaust aftertreatment system 42.

[0042] The engine data processor 1 can, for example, have a discharge data interface 33, at which it receives a geometric characteristic 10 of the discharge unit 11 through which the adjustable exhaust gas composition 25 can be discharged. The discharge unit 11 is, for example, an arrangement of several cylindrical chimneys 23, and the geometric characteristic 10 is, for example, a diameter 24 of a chimney 23. Alternatively, the geometric characteristic 10 can be a cross-sectional area of ​​all chimneys 23 (not shown).

[0043] The engine data processor 1 is designed to determine a smoke visibility limit value 21 depending on the geometric characteristic 10. The smoke visibility limit value 21 is a specific value of a physical quantity at which no visible smoke 2 escapes from the exhaust unit 11, but above which visible smoke 2 is to be expected. The value can be determined, for example, using a unit 8 for determining a smoke visibility limit value, which unit has a lookup table (not shown) in which values ​​of a quantity, such as a nitrogen oxide emission value, are compiled with corresponding values ​​of the geometric characteristic 10. The smoke visibility limit value 21 is preferably a nitrogen dioxide limit value.

[0044] For example, the smoke visibility limit 21 is an exclusive nitrogen dioxide limit value, which the exhaust gas composition 25 may not exceed in order to remain invisible. Alternatively, the smoke visibility limit 21 is a nitrogen dioxide limit value which the exhaust gas composition 25 may inclusively reach in order to remain invisible, but exceeding which leads to the exhaust gas composition 25 becoming visible.

[0045] Furthermore, the engine data processor 1 can have a filter state data input 51, at which a filter filling state information 20 of an exhaust gas filter 16 designed to filter the exhaust gas composition 25 can be received (see Fig. 2 ). The received filter fill status information 20 includes an indication of how empty or full the exhaust filter 16 currently is and has an effect on the amount of nitrogen dioxide present in the exhaust gas composition 25 after it has been filtered.

[0046] In addition, the engine data processor 1 can have a temperature data input 31 at which an average catalyst temperature 22 of an exhaust gas catalyst 18 designed to catalyze the exhaust gas composition 25 can be received (see Fig. 2 ). The average catalyst temperature 22 has an effect on the amount of nitrogen dioxide present in the exhaust gas composition 25 after it has been catalyzed.

[0047] The engine data processor 1 is advantageously configured to calculate a series 28 of nitrogen dioxide conversion rates 12 depending on the received filter fill level information 20. A nitrogen dioxide conversion rate 12 indicates the value of a quantity of nitrogen oxide in the exhaust gas composition 25 that is converted into nitrogen dioxide during exhaust aftertreatment, for example, in the exhaust aftertreatment system 42. It has been recognized that the nitrogen dioxide conversion rate plays an important role in the formation of visible smoke 2, particularly yellow smoke.

[0048] The series 28 of nitrogen dioxide conversion rates 12 indicates the values ​​which the amount of nitrogen dioxide in the exhaust gas composition 25 can assume when it is filtered in the exhaust gas filter 16 at a filter filling state according to the filter filling state information 20.

[0049] The engine data processor 1 is further configured to determine a nitrogen dioxide conversion rate 12 as a function of the received filter filling state information 20 and the average catalyst temperature 22.

[0050] The nitrogen dioxide conversion rate 12, determined as a function of the average catalyst temperature 22 and the filter fill level information 20, indicates the value of the amount of nitrogen dioxide present in the exhaust gas composition 25, which it assumes after catalysis in the exhaust gas catalyst 18 when the average catalyst temperature 22 is present, and after filtration in the exhaust gas filter 16 when the filter fill level recorded in the filter fill level information 20 is present. Taking into account the average catalyst temperature 22 and the filter fill level information 20 enables a precise determination of the nitrogen dioxide conversion rate 12.

[0051] Fig. 3 exemplifies the relationship between two different filter filling state information 20 in different time periods T1 and T2 (top left, bottom left) and the determination of the series 28 of nitrogen dioxide conversion rates 12 based thereon.

[0052] An axis Y20a shows the level of filter filling state information 20 in the top left corner during a first time period T1. The level of filter filling state information 20 along the axis Y20a is high and indicates a filled exhaust filter 16. Fig. 3 , top right, a first curve 40 and a second curve 50 were plotted, representing possible series of nitrogen dioxide conversion rates 12 (axis Y12a) as a function of the average catalyst temperature 22 (axis X22a). Since the exhaust filter 16 is filled (see top left, axis Y20a), the first curve 40 is determined as series 28 of the nitrogen dioxide conversion rates 12, and the second curve 50 is not considered further.

[0053] At the bottom left, however, the level of the filter filling state information 20 is low (axis Y20b) during a period T2, indicating an empty or barely filled exhaust filter 16. This causes the second curve 50 with the higher nitrogen dioxide conversion rates 12 to be determined from the possible curves 40 and 50 at the bottom right as series 28 of the nitrogen dioxide conversion rates 12, and in this case, the first curve 40 is not considered further.

[0054] How Fig. 3 , right, the nitrogen dioxide conversion rate 12 corresponding to the conditions under which the exhaust gas composition 25 has been aftertreated can be determined from the selected series 28 of nitrogen dioxide conversion rates 12 as a function of the mean catalyst temperature 22 received from the engine data processor 1.

[0055] Advantageously, the engine data processor 1 is designed to determine a nitrogen dioxide conversion rate 12 from the series 28 of nitrogen dioxide conversion rates as a function of the received average catalyst temperature 22.

[0056] The engine data processor 1 is configured to compare the calculated nitrogen dioxide conversion rate 12 and the smoke visibility limit 21 with each other and to determine a control variable 5 for the internal combustion engine therefrom such that the exhaust gas composition 25 is invisible, and to output the control variable 5. The engine data processor may have an output data interface 39 for outputting the control variable 5.

[0057] By incorporating the geometric characteristic 10 of the exhaust unit 11 when determining the manipulated variable 5 for internal combustion engine operation, an important, customer-specific operating attribute is taken into account in order to set a permanently invisible exhaust gas composition 25. By taking the geometric characteristic 10 into account, each engine data processor 1 can be adjusted depending on the installation conditions of the corresponding internal combustion engine so that, regardless of the internal combustion engine installation space, clean and cost-effective internal combustion engine operation with a dirt-free and invisible exhaust gas composition 25 can be enabled.

[0058] Furthermore, by taking into account the catalyst temperature 22 and the filter filling state information 20, an accurate nitrogen dioxide conversion rate 12 is determined, which reflects at any time, for example also in real time, the conditions under which the exhaust gas composition 25 is aftertreated, thereby increasing the adjustment accuracy of the exhaust gas composition 25.

[0059] The internal combustion engine 30 according to Fig. 2 comprises the engine data processor 1, an engine 19 for providing mechanical power 43, and an exhaust aftertreatment system 42, which includes the exhaust gas catalyst 18 and the exhaust gas filter 16. Advantageously, the exhaust aftertreatment system 42 can include the discharge unit 11. The engine 19 is operated, for example, with a fuel 44.

[0060] Thanks to the described features of the engine data processor 1, the internal combustion engine 30 according to the invention can be operated with optimal operating costs and without visible smoke 2. In particular, the adjustment of the exhaust gas composition 25, taking into account the engine installation space (not shown) and the geometric characteristics 10 of the exhaust unit 11, can advantageously be carried out entirely in the engine data processor 1 and thus internally in the internal combustion engine 30.

[0061] In an advantageous embodiment, the engine data processor 1 is configured to receive a nitrogen oxide emission value 9 detected at the exhaust unit 11 and a discharge unit pressure value 13, and to determine the smoke visibility limit 21 therefrom. Taking these variables into account at the exhaust unit 11 enables a more precise determination of the smoke visibility limit 21. Advantageously, the internal combustion engine 30 comprises a first pressure sensor 47 for measuring the discharge unit pressure value 13 and a gas concentration sensor 49 for detecting the nitrogen oxide emission value 9.

[0062] Advantageously, the engine data processor 1 is configured to receive a filter pressure value 14 of the exhaust filter 16 and the discharge unit pressure value 13, and to determine the filter condition information 20 from the discharge unit pressure value 13 and the filter pressure value 14. Using the filter pressure value 14 and the discharge unit pressure value 13 enables a precise determination of the filter condition information 20 in real time, which enables a more accurate determination of the nitrogen dioxide conversion rate 12. In an advantageous embodiment, the internal combustion engine 30 comprises a second pressure sensor 48 for measuring the filter pressure value 14.

[0063] In a further embodiment, the engine data processor 1 is configured to receive a filter temperature 15 and a catalyst temperature 17 and to measure the average catalyst temperature 22 therefrom. This enables a more accurate determination of the more accurate average catalyst temperature 22 and, consequently, also a more accurate determination of the nitrogen dioxide conversion rate 12. Preferably, the internal combustion engine 30 comprises a first temperature sensor 45 for measuring the filter temperature 15 and a second temperature sensor 46 for measuring the catalyst temperature 17.

[0064] Preferably, the engine data processor 1 is configured to suppress yellow smoke and is further configured to determine at least one smoke visibility threshold 21 configured as a yellow smoke visibility threshold 3 and to determine the manipulated variable 5 for the internal combustion engine 30 such that the generation of yellow smoke is suppressed. Yellow smoke is a type of visible smoke 2 that frequently occurs during the operation of internal combustion engines.

[0065] Preferably, the engine data processor 1 comprises a conversion unit 32, which is designed to calculate the series 28 of increased or decreased nitrogen conversion rates 12 depending on the filter filling state information 20. Advantageously, the engine data processor 1 comprises a conversion unit 32, which is designed to calculate lower nitrogen conversion rates 12 with increasing exhaust gas filter filling. This enables a continuous adaptation of the calculated nitrogen conversion rates 12 to the currently determined filter filling state and contributes to a more accurate determination of the nitrogen dioxide conversion rate 12. The functioning of the conversion unit 32 can advantageously be based on the illustration from Fig. 3 are equivalent to.

[0066] In an advantageous embodiment, the engine data processor 1 comprises a model-predictive controller 35, wherein the model-predictive controller 35 comprises a limiting unit 41 configured to receive the nitrogen dioxide conversion rate 12 and the smoke visibility limit 21, compare them with each other, and use them to create an operating limit 34 for setting an invisible exhaust gas composition 25 for the internal combustion engine 30. This enables cost-optimized internal combustion engine operation and simultaneous avoidance of visible smoke 2.

[0067] In an advantageous embodiment, the model-predictive controller 35 is configured to generate operationally optimal controller specifications 38 for adjusting the average catalyst temperature 22. This enables the creation of commands with which the detected average catalyst temperature 22 can be actively influenced in order to enable not only the invisible exhaust gas composition 25 but also cost-optimized operation of the internal combustion engine 30.

[0068] Preferably, the internal combustion engine 30 comprises an actuator controller 37, which is configured to receive the operationally optimal controller specifications 38 and to determine the manipulated variable 5 for an actuation group 29 of the engine 19 therefrom. The manipulated variable 5 is, for example, commands to actuate an actuation group 29, configured as valves, in the engine 19 for a specific duration and in a specific sequence such that a specific engine exhaust temperature 4 can be set for cost-optimally influencing the average catalyst temperature 22. This makes it possible to use the engine exhaust temperature 4 to influence the average catalyst temperature 22, thus enabling cost-effective internal combustion engine operation.

[0069] The engine data processor 1 advantageously comprises a control unit 36, which comprises the model predictive controller 35 and the actuator controller 37

[0070] In an advantageous embodiment, the engine data processor 1 can have an input data interface 27 via which the control unit 36 ​​can receive operating parameters 26 from the engine 19 in order to monitor the actuation of the actuation group 29 designed as valves.

[0071] Advantageously, the engine data processor comprises a data memory 7 in which data from the unit 8 for determining a smoke visibility limit, the conversion unit 32, and the control unit 36 ​​can be stored. These units can also have access to the data. In this way, in the illustration from Fig. 3 , on the right, next to the series 28 of nitrogen dioxide conversion rates 12, a current smoke visibility limit of 21.3 is also plotted.

[0072] According to Fig. 4A computer-implemented method 100 for adjusting a filtered and catalyzed exhaust gas composition 25 at a discharge unit 11 of an internal combustion engine 30 comprises the following steps: 101: Receiving a geometric characteristic 10 of the discharge unit 11, 102: Determining a smoke visibility limit value 21.3 from the geometric characteristic 10, 103: Receiving an average catalyst temperature 22 and filter filling state information 20 and determining a nitrogen dioxide conversion rate 12 as a function of the catalyst temperature 22 and the filter filling state information 20, 104: Comparing the determined smoke visibility limit value 21.3 with the nitrogen dioxide conversion rate 12 and, 105: Determining a manipulated variable 5 with which the internal combustion engine 30 is operated such that the exhaust gas composition 25 to be discharged at the discharge unit 11 is invisible.

[0073] The method 100 is advantageous because it enables cost-effective internal combustion engine operation without visible smoke 2. Taking into account the geometric characteristics 10 of the exhaust unit 11 enables a precise determination of the manipulated variable 5 and a flexible adaptation of the method 100 to exhaust units 11 with different geometric characteristics 10. Taking into account the average catalyst temperature 22 and the filter fill level information 20 increases the accuracy of adjusting the exhaust gas composition 25.

Claims

1. An engine data processor (1) for adjusting an exiting exhaust gas composition (25) for an internal combustion engine, wherein the engine data processor (1) is configured to: - receive a geometric characteristic (10) of a discharge unit (11) through which the exhaust gas composition (25) can be discharged, and to determine a smoke visibility limit value (21, 3) therefrom, - receive filter fill state information (20) of an exhaust gas filter (16) designed to filter the exhaust gas composition (25), - receive an average catalyst temperature (22) of an exhaust gas catalyst (18) designed to catalyze the exhaust gas composition (25) and to determine a nitrogen dioxide conversion rate (12) as a function of the filter fill state information (20) and the average catalyst temperature (22), - determine the nitrogen dioxide conversion rate (12) and the smoke visibility limit value (21,3) to compare them with each other and to determine therefrom a control variable (5) for the internal combustion engine in such a way that the exhaust gas composition (25) is invisible, and - to output the control variable (5).

2. Engine data processor (1) according to claim 1, wherein the engine data processor (1) is designed: - to calculate a series (28) of nitrogen dioxide conversion rates (12) as a function of the filter filling state information (20), and - to determine the nitrogen dioxide conversion rate (12) from the series (28) as a function of the average catalyst temperature (22).

3. Engine data processor (1) according to claim 1 or 2, wherein the engine data processor (1) is designed to receive a nitrogen oxide emission value (9) detected at the exhaust unit (11) and a exhaust unit pressure value (13) and to determine the smoke visibility limit value (21) therefrom.

4. Engine data processor (1) according to claim 3, wherein the engine data processor (1) is configured to receive a filter pressure value (14) and to determine the filter filling state information (20) from the discharge unit pressure value (13) and the filter pressure value (14).

5. Engine data processor (1) according to one of the preceding claims, wherein the engine data processor (1) is designed to receive a filter temperature (15) and a catalyst temperature (17) and to determine the average catalyst temperature (22) therefrom.

6. Engine data processor (1) according to one of the preceding claims for suppressing yellow smoke (2), wherein the engine data processor (1) is designed: - to determine at least one smoke visibility limit value (21) designed as a yellow smoke visibility limit value (3), - to determine the manipulated variable (5) such that the generation of visible yellow smoke (2) is suppressed.

7. Engine data processor (1) according to one of the preceding claims, comprising a conversion calculation unit (32) which is designed to calculate a series (28) of increased or reduced nitrogen dioxide conversion rates (12) as a function of the filter filling state information (20).

8. Engine data processor (1) according to one of the preceding claims, comprising a model predictive controller (35), wherein the model predictive controller (35) comprises a limiting unit (41) which is designed to receive the nitrogen dioxide conversion rate (12) and the smoke visibility limit (21) and to create therefrom an operating limit (34) for setting an invisible exhaust gas composition (25) for the internal combustion engine.

9. Internal combustion engine (30), comprising an engine data processor (1) according to one of the preceding claims, an engine (19) for providing a mechanical power (43) and an exhaust gas aftertreatment system (42) which comprises the exhaust gas catalyst (18) and the exhaust gas filter (16).

10. Internal combustion engine (30) according to claim 9, wherein the model predictive controller (35) is designed to derive operationally optimal controller specifications (38) for setting the mean catalyst temperature (22) from the operating limit (34).

11. Internal combustion engine (30) according to claim 10, comprising an actuator controller (37) which is designed to receive the operationally optimal controller specifications (38) and to determine the manipulated variable (5) for an actuation group (29) of the engine (19). 12.Computer-implemented method (100) for adjusting a filtered and catalyzed exhaust gas composition (25) at a discharge unit (11) of an internal combustion engine (30), comprising the following steps: -Step 101: Receiving a geometric characteristic (10) of the discharge unit (11); Step 102: Determining a smoke visibility limit value (21) from the geometric characteristic (11); Step 103: Receiving an average catalyst temperature (22) and filter filling state information (20) and determining a nitrogen dioxide conversion rate (12) as a function of the catalyst temperature (17) and the filter filling state information (20); Step 104: Comparing the determined smoke visibility limit value (21) with the nitrogen dioxide conversion rate (12); and Step 105: Determining a manipulated variable (5) with which the internal combustion engine (30) is operated such that the the exhaust gas composition (25) to be discharged at the discharge unit (11) is invisible.