CONTROL OF THE AFTERTREATMENT OF AN INTERNAL COMBUSTION ENGINE

Abstract

Device (100) for controlling an aftertreatment system of an internal combustion engine (101), wherein the device (100) comprises a processing means (102) configured for: Receiving a first signal from a first temperature measuring device (103), indicating a first temperature of exhaust gases emitted by an internal combustion engine (101) at a first position upstream of a first exhaust system component (104) designed to provide a passage for exhaust gases; Receiving a second signal from a flow velocity measuring device (105), indicating a flow velocity of the exhaust gases emitted by the engine; Calculating an approximate value at least from the first signal and the second signal, wherein the approximate value indicates a second temperature of exhaust gases at a position downstream of the first exhaust system component (104), wherein calculating the approximate value comprises: Receiving a stored value of a concentration for each of a multitude of exhaust gases and calculating a rate of heat generated by chemical reactions of the exhaust gases during the flow of the exhaust gases through the first exhaust system component (104); and Providing an output signal to control the post-treatment system according to the calculated approximate value.

Description

TECHNICAL AREA

[0001] The present disclosure relates to the control of an aftertreatment system for an internal combustion engine. In particular, but not exclusively, it relates to the control of the aftertreatment system for diesel engines in motor vehicles. Aspects of the invention relate to a device, a system, a vehicle, and a method. BACKGROUND

[0002] Over the past two decades, diesel aftertreatment systems have become increasingly complex to meet the targets of legal emissions regulations for motor vehicles. These systems have incorporated several components, such as a diesel oxidation catalyst (DOC) to convert carbon monoxide and hydrocarbons into carbon dioxide, a diesel particulate filter (DPF) to filter out and burn off soot, and a selective catalytic reduction (SCR) system to treat nitrogen oxides (NOx). xRecently, the DOC in some systems has been replaced by a nitrogen oxide trap (Lean NOₓ). x Trap, LNT) replaces, which essentially performs the same functions as the DOC, but additionally provides storage and conversion of NO. x at low temperature.

[0003] Existing systems present a problem because the components generally operate independently. This necessitates a large number of sensors for the system's thermal and chemical management. It also means that a large number of signals received from these sensors must be analyzed. Furthermore, temperature sensors exhibit poor response times and accuracy. Additionally, the sensors require complex monitoring functions for diagnostic purposes, increasing the overall system cost.

[0004] Another problem lies in the difficulty of achieving an optimal fuel / urea consumption balance for the NOₓ x -To ensure conversion between LNT and SCR.

[0005] GB 2 470 391 A relates to a method and a control system for diagnosing a diesel oxidation catalyst (DOC) located in an exhaust pipe within a diesel engine system.

[0006] US 2013 / 0204508A1 relates to a method for controlling regeneration within an aftertreatment component of an engine, which includes receiving an upstream temperature signal representing the temperature of an exhaust gas stream upstream of the aftertreatment component, and calculating an expected downstream temperature based on the upstream temperature signal and a model for calculating the expected downstream temperature.

[0007] DE 60 2005 000 440 T2 relates to the regulation of a regeneration phase of a particulate filter by combustion of the particles that have accumulated in the filter, wherein the filter is mounted on an exhaust pipe of an internal combustion engine, in particular a diesel engine, and is connected to an oxidation catalyst device which is also mounted on the exhaust pipe above the particulate filter.

[0008] One object of the present invention is to eliminate the disadvantages of the systems according to the prior art. SUMMARY OF THE INVENTION

[0009] Aspects and embodiments of the invention provide a device, a system, a vehicle and a method according to the attached claims.

[0010] According to one aspect of the invention, a device for controlling an aftertreatment system of an internal combustion engine is provided, wherein the device comprises a processing means configured for: receiving a first signal from a first temperature measuring means, indicating a first temperature of exhaust gases emitted by an internal combustion engine at a first position upstream of a first exhaust system component configured to provide a passage for exhaust gases; receiving a second signal from a flow velocity measuring means, indicating a flow velocity of the exhaust gases emitted by the internal combustion engine; calculating an approximate value at least from the first signal and the second signal, wherein the approximate value indicates a second temperature of exhaust gases at a position downstream of the first exhaust system component;and supplying an output signal to control the post-treatment system according to the calculated approximate value.

[0011] This offers the advantage of reducing the number of sensors used to monitor an internal combustion engine aftertreatment system. It also provides an improved response time to changes in the exhaust gas temperature at a secondary location.

[0012] In one embodiment, the output signal is supplied to fuel injectors to control a rate of fuel injection.

[0013] In some embodiments, the processing means comprises a processor; the first temperature measuring means comprises a first temperature sensor; the flow velocity measuring means comprises a flow velocity sensor; and the fuel injection means comprises a diesel injection nozzle.

[0014] In some embodiments, the processing means is designed to calculate a rate of heat loss from the exhaust gases during the flow of the exhaust gases through the first exhaust system component.

[0015] This offers the advantage that the temperature of the exhaust gases flowing out of the first exhaust system component can then be calculated if the heat loss from the exhaust gases is a significant factor in determining their temperature change.

[0016] The processing means can be designed to calculate a rate of heat loss from the exhaust gases to a substrate of the first exhaust system component during the flow of the exhaust gases through the first exhaust system component.

[0017] This offers the advantage that changes in the temperature of the substrate can be determined, which allows for accurate calculations of the approximate value indicating the second temperature of the exhaust gases.

[0018] The processing device can be designed to calculate a rate at which heat is dissipated from the substrate to the surrounding material.

[0019] This offers the advantage that precise values ​​for the rate of heat loss from the exhaust gases to the substrate can be determined.

[0020] In some embodiments, the processing means is designed to calculate a rate of heat generated by chemical reactions during the flow of exhaust gases through the first exhaust system component.

[0021] This offers the advantage that the temperature of the exhaust gases flowing out of the first exhaust system component can then be calculated if the first exhaust system component is designed to promote chemical reactions in the exhaust gases.

[0022] In some embodiments, the first exhaust system component comprises a substrate that includes a catalyst designed to promote chemical reactions of gas components of the exhaust gases.

[0023] The first exhaust system component can be a nitrogen oxide trap (lean NOₓ trap). x include a trap, LNT) or a diesel oxidation catalyst (Diesel Oxidation Catalyst, DOC).

[0024] In some embodiments, the processing means is designed to detect a pressure drop in the exhaust gases between an inlet of the first exhaust system component and an outlet of the first exhaust system component.

[0025] This offers the advantage that a more accurate temperature of the exhaust gases flowing out of the first exhaust system component can then be calculated if a pressure drop of the exhaust gases is a factor in determining their temperature change.

[0026] In some embodiments, the processing means is configured to: calculate an intermediate value from the first signal and the second signal, wherein the intermediate value indicates an intermediate temperature of exhaust gases at a position downstream of a second exhaust system component and upstream of the first exhaust system component; and calculate the approximate value indicating a second temperature from the intermediate value.

[0027] This offers the advantage that a more accurate temperature of the exhaust gases flowing out of the first exhaust system component can then be calculated if an exhaust system component is located between the position of the first measuring device and the position for which the approximate value is calculated.

[0028] The second exhaust system component may include a turbocharger.

[0029] In some embodiments, the processing means is configured to: receive a third signal indicating a third temperature of exhaust gases downstream of a further exhaust system component, wherein the further exhaust system component is arranged downstream of the first exhaust system component; and calculate a correction of the approximate value according to the third signal.

[0030] This offers the advantage that an approximate value, which can be determined with a short reaction time to temperature changes but may not be as accurate as desired, can be regularly corrected, leading to accurate approximate values ​​that also react quickly to temperature changes in the exhaust gases.

[0031] The correction of the approximate value can be determined by calculating a rate of heat loss from the exhaust gases during the flow of the exhaust gases through the further exhaust system component.

[0032] The other exhaust system component may include a diesel particulate filter.

[0033] In some embodiments, the processing means comprises an electronic processor with an electrical input for receiving the first and second signals and an electronic storage device electrically coupled to the electronic processor in which instructions are stored, wherein the processor is configured to access the storage device and to execute the instructions stored therein, such that it is configured to receive the first and second signals, calculate the approximate value indicating the second temperature, and control the at least one fuel injector according to the approximate value.

[0034] According to a further aspect of the invention, a system for treating exhaust gases from a diesel engine is provided, wherein the system comprises a device as previously described and a plurality of exhaust system components designed to provide a passage for the exhaust gases, wherein the plurality of exhaust system components includes the first exhaust system component.

[0035] This offers the advantage of reducing the number of sensors required to monitor a diesel aftertreatment system. It also provides an improved response time to changes in exhaust gas temperature at a second location.

[0036] According to another aspect of the invention, a vehicle comprising a diesel engine and a system as previously described is provided.

[0037] According to a further aspect of the invention, a method for controlling the exhaust aftertreatment for an internal combustion engine is provided, the method comprising: receiving a first signal from a first temperature sensor, indicating a first temperature of exhaust gases emitted by an internal combustion engine at a first position upstream of a first exhaust system component configured to provide a passage for exhaust gases; receiving a second signal from a flow velocity sensor, indicating a flow velocity of the exhaust gases emitted by an internal combustion engine; calculating an approximate value at least from the first signal and the second signal, wherein the approximate value indicates a second temperature of exhaust gases downstream of the first exhaust system component; and supplying an output signal for controlling the exhaust aftertreatment according to the calculated approximate value.

[0038] This offers the advantage of reducing the number of sensors required to monitor an internal combustion engine aftertreatment system. It also provides an improved response time to changes in exhaust gas temperature at the secondary temperature sensor.

[0039] In one embodiment, the output signal is supplied to fuel injectors to control a rate of fuel injection.

[0040] In some embodiments, the calculation includes calculating a rate of heat loss from the exhaust gases during the flow of the exhaust gases through the first exhaust system component.

[0041] This offers the advantage that an accurate temperature of the exhaust gases flowing out of the first exhaust system component can then be calculated if the heat loss from the exhaust gases is a significant factor in determining their temperature change.

[0042] In some embodiments, the calculation includes calculating a rate of heat loss from the exhaust gases to a substrate of the first exhaust system component during the flow of the exhaust gases through the first exhaust system component.

[0043] This offers the advantage that changes in the temperature of the substrate can be determined, which allows for accurate calculations of the approximate value indicating the second temperature of the exhaust gases.

[0044] The calculation may involve calculating the rate at which heat is dissipated from the substrate to the surrounding material.

[0045] This offers the advantage that precise values ​​for the rate of heat loss from the exhaust gases to the substrate can be determined.

[0046] In one embodiment, the processing means is designed to calculate the temperature of the substrate and the rate of heat loss from the exhaust gases to the substrate according to the difference between the temperature of the exhaust gases and the temperature of the substrate.

[0047] In one embodiment, the processing means is designed to calculate the rate of heat loss from the exhaust gases to the substrate according to a stored value for the heat transfer coefficient.

[0048] In some embodiments, the processing means is configured to receive a stored value of a concentration for each of a plurality of exhaust gases, and the calculation includes calculating a rate of heat generated by chemical reactions of the exhaust gases during the flow of the exhaust gases through the first exhaust system component.

[0049] This offers the advantage that the temperature of the exhaust gases flowing out of the first exhaust system component can then be calculated if the first exhaust system component is designed to promote chemical reactions in the exhaust gases.

[0050] In some embodiments, the calculation includes calculating a pressure drop in the exhaust gases between the pressure of gases at an inlet of the first exhaust system component and an outlet of the first exhaust system component.

[0051] This offers the advantage that a more accurate temperature of the exhaust gases flowing out of the first exhaust system component can then be calculated if a pressure drop of the exhaust gases is a factor in determining their temperature change.

[0052] In some embodiments, the calculation comprises: calculating an intermediate value from the first signal and the second signal, wherein the intermediate value indicates an intermediate temperature of exhaust gases at a position downstream of a second exhaust system component and upstream of the first exhaust system component; and calculating the approximate value indicating a second temperature from the intermediate temperature.

[0053] This offers the advantage that a more accurate temperature of the exhaust gases flowing out of the first exhaust system component can then be calculated if an exhaust system component is located between the position of the first measuring device and the position for which the approximate value is calculated.

[0054] In some embodiments, the method comprises receiving a third signal indicating a third temperature of exhaust gases downstream of another exhaust system component, wherein the third exhaust system component is located downstream of the first exhaust system component, and includes calculating a correction of the approximate value according to the third signal.

[0055] This offers the advantage that an approximate value, which can be determined with a short reaction time to temperature changes but may not be as accurate as desired, can be regularly corrected, leading to accurate approximate values ​​that also react quickly to temperature changes in the exhaust gases.

[0056] Calculating a correction may involve calculating a rate of heat loss from the exhaust gases as they flow through the subsequent exhaust system component.

[0057] According to a further aspect of the invention, a device for controlling the injection into an internal combustion engine is provided, the device comprising an electronic processor and an electronic storage device electrically coupled to the electronic processor and in which instructions are stored, the processor being configured to access the storage device and execute the instructions stored therein such that it is capable of: receiving a first signal from a first temperature sensor indicating a first temperature of exhaust gases emitted by an internal combustion engine at a first position upstream of a first exhaust system component configured to provide a passage for exhaust gases; receiving a second signal from a flow velocity sensor indicating a flow velocity of the exhaust gases emitted by an internal combustion engine;Calculating an approximate value from at least the first signal and the second signal, wherein the approximate value indicates a second temperature of exhaust gases downstream of the first exhaust system component; and supplying an output signal for controlling at least one injector according to the calculated approximate value.

[0058] This offers the advantage of reducing the number of sensors required to monitor an internal combustion engine aftertreatment system. It also provides an improved response time to changes in exhaust gas temperature.

[0059] According to a further aspect of the invention, a device for controlling the injection into an internal combustion engine is provided, wherein the device comprises a processing means configured for: receiving a first signal from a first temperature measuring means, indicating a first temperature of exhaust gases emitted by an internal combustion engine at a first position upstream of a first exhaust system component configured to provide a passage for exhaust gases; receiving a second signal from a flow velocity measuring means, indicating a flow velocity of the exhaust gases emitted by an internal combustion engine; determining an approximate value at least from the first signal and the second signal, wherein the approximate value indicates a characteristic of exhaust gases at a position downstream of the first exhaust system component;and supplying an output signal to control a rate of fuel injection according to the approximate value.

[0060] This offers the advantage of reducing the number of sensors used to monitor an internal combustion engine aftertreatment system. In particular, no sensor is required to measure exhaust gas characteristics downstream of the first exhaust system component.

[0061] In some embodiments, the characteristic includes a measure of the mass flow rate of a gas component of the exhaust gases. The gas component can consist of one or more nitrogen oxides.

[0062] This offers the advantage of eliminating the need for a sensor specifically designed to measure the gas component. Furthermore, response times to changes in the quantity of the gas component present in the exhaust gases downstream of the first exhaust system component can be improved. For example, if the first exhaust system component is designed to promote chemical reactions in the exhaust gases, changes in the quantity of the gas component present after it has passed through the first exhaust system component can be detected more quickly than in a system that measures the gas component at the outlet of the first exhaust system component.

[0063] In some embodiments, the characteristic includes a temperature of exhaust gases.

[0064] This offers the advantage of reducing the number of temperature sensors required to monitor an internal combustion engine aftertreatment system. It also provides an improved response time to changes in exhaust gas temperature.

[0065] According to a further aspect of the invention, a device for treating exhaust gases originating from an internal combustion engine is provided, the method comprising: a first component configured for removing a first component of the exhaust gases; a second component configured for removing a second component of the exhaust gases; a first temperature measuring means configured for providing an output signal indicating a measured temperature of exhaust gases, wherein the first temperature measuring means is arranged at a first position upstream of the first component; and a second temperature measuring means configured for providing an output signal indicating a measured temperature of exhaust gases, wherein the second temperature measuring means is arranged at a second position downstream of the second component, the device not comprising a temperature measuring means arranged between the first component and the second component.

[0066] This offers the advantage of requiring fewer temperature sensors compared to existing systems. This reduces difficulties in accommodating the sensors. The number of temperature sensor signals that need to be analyzed is also reduced.

[0067] Within the scope of this application, it is expressly intended that the different aspects, embodiments, examples, and alternatives presented in the preceding paragraphs, in the claims, and / or in the following description and drawings, and in particular their individual features, may be considered independently of one another or in any combination. This means that all embodiments and / or features of any embodiment may be combined in any way and / or combination, provided that these features are not incompatible.The applicant reserves the right to amend any originally filed patent claim or to file any new patent claim accordingly, including the right to amend any originally filed patent claim to depend on and / or incorporate any feature of any other claim, even if it was not previously claimed in this manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] One or more embodiments of the invention are described below by way of example with reference to the accompanying drawings. Fig. Figure 1 shows a block diagram of a vehicle 110 comprising a system 106 which includes an exemplary device 100. Fig. Figure 2 shows a block diagram of a vehicle 110, comprising a second system 106A, which includes an exemplary device 100. Fig. Figure 3 shows a schematic diagram illustrating how a submodule of a mathematical model models a single exhaust system component 301. Fig. Figure 4 shows equations derived from the processing agent 102. Fig. 1 or Fig. 2 can be used to model the gas phase in a catalyst exhaust system component. Fig. Figure 5 shows equations that can be used by the processing agent 102 to model the solid phase in a wall-flow or flow-through catalyst exhaust system component. Fig. Figure 6 shows equations that can be used by the processing agent 102 to model the chemical reactions taking place in an exhaust system component. Fig. Figure 7 shows equations that can be used by the processing agent 102 to model pressure drops in an exhaust system component. Fig. Figure 8 shows an equation (21) used by the processing agent 102 to determine a rate of change of temperature. (∂TIN∂t) can be used at the DPF inlet. Fig. Figure 9 shows equations that can be used by the processing unit 102 to model the effects of a turbocharger on the exhaust gases. Fig. Figure 10 shows a flow diagram of a process 1000 for controlling the injection in a diesel engine. Fig. Figure 11 shows a flowchart of an example of processes that are in block 1003 of Fig. 10 can be carried out. Fig. Figure 12 shows a flowchart of processes that take place in block 1101 of Fig. 11 can be carried out. Fig. Figure 13 shows a flow diagram of processes that can be carried out when two or more exhaust system components are positioned between a position of a measured temperature and a position for which the approximate temperature is calculated. Fig. Figure 14 shows a flow diagram of processes that can be carried out to improve the accuracy of the approximation for the second temperature. DETAILED DESCRIPTION

[0069] The figures show a device 100 for controlling the injection into an internal combustion engine (diesel engine, motor) 101, wherein the device 100 comprises a processing means 102 configured for: receiving a first signal from a first temperature measuring means 103, indicating a first temperature of exhaust gases emitted by an internal combustion engine 101 at a first position upstream of a first exhaust system component 104 configured to provide a passage for exhaust gases; receiving a second signal from a flow velocity measuring means (sensor) 105, indicating a flow velocity of the exhaust gases emitted by an internal combustion engine; calculating an approximate value at least from the first signal and the second signal, wherein the approximate value indicates a second temperature of exhaust gases at a position downstream of the first exhaust system component;and supplying an output signal to control a fuel injection rate according to the calculated approximate value.

[0070] The approximate value can be an approximation of the actual temperature of exhaust gases at the position downstream of the first exhaust system component.

[0071] An example of a device 100 is shown in the block diagram of Fig. 1 shown. As in Fig. As shown in Figure 1, the device 100 can form part of a system 106 for treating exhaust gases from a diesel engine 101. The system comprises the device 100 and a plurality of exhaust system components configured to provide a passage for the exhaust gases, the plurality of exhaust system components 107 comprising the first exhaust system component 104. The Fig. The system 106 shown in Figure 1 comprises the first exhaust system component 104, the second exhaust system component 108, and a further exhaust system component 109. Other systems implementing the present invention may also comprise more or fewer than three exhaust system components. (A detailed explanation follows regarding...) Fig. 2 a system comprising four exhaust system components is described.)

[0072] The exhaust system 106 is designed to receive exhaust gases from the diesel engine 101, and the diesel engine 101 and the system 106 are components of a vehicle 110.

[0073] In an alternative arrangement, the exhaust system 106 can be designed to receive exhaust gases from a gasoline engine instead of the diesel engine 101.

[0074] The device 100 can be an engine control unit designed to control diesel injection nozzles 111 in the engine 101 or a correspondingly designed powertrain control module.

[0075] In the present embodiment, the second exhaust system component 108 comprises a turbocharger 108.

[0076] The device 100 comprises a processing unit 102 for receiving a first signal from a first temperature measuring device 103, indicating a first temperature of exhaust gases emitted by the diesel engine 101 at a first position upstream of the first exhaust system component 104, which is configured to provide a passage for exhaust gases. (In the present embodiment, the first temperature measuring device 103 is also arranged upstream of the second exhaust system component 108.) The processing unit 102 is also configured for receiving a second signal from a flow velocity measuring device 105, indicating a flow velocity of the exhaust gases emitted by the diesel engine 101, and for calculating an approximate value from the first and second signals. The approximate value indicates a second temperature of exhaust gases at a position 112 downstream of the first exhaust system component 104.The processing means is also designed to provide an output signal for controlling the diesel injection through the diesel injection nozzles 111 according to the calculated approximate value.

[0077] It can be noted that the flow velocity measuring device 105 is located at the inlet side of the engine; however, the mass flow rate from the engine can be calculated based on the mass flow rate into the engine and the mass of fuel injected into the engine. Thus, the second signal supplied by the flow velocity measuring device 105 provides a signal indicating the flow velocity of the exhaust gases emitted by the diesel engine 101.

[0078] The processing means can comprise an electronic processor 113 with an electrical input for receiving the first signal from a first temperature measuring means 103 and for receiving the second signal from a flow velocity measuring means 105. The processing means can further comprise an electronic storage device 114, which is electrically coupled to the electronic processor 113 and in which instructions are stored electronically, wherein the processor 113 is configured to access the storage device 114 and to execute the instructions stored therein, such that it is configured to receive the first and second signals, calculate the approximate value indicating the second temperature, and control the diesel injection nozzles 111 according to the approximate value.The instructions stored in the storage device 114 can form a computer program 151 and the computer program 151 can be provided to the processing device for storage in the storage device 114.

[0079] The electronic storage device 114 can also store map-based models specific to the engine 101, providing an indication of the concentrations of exhaust gases, including hydrocarbon and carbon monoxide concentrations, produced by the engine at various engine settings, which is state of the art. The electronic storage device 114 can also electronically store NO values. x and store soot particle concentrations generated by the engine. These stored map-based models include values ​​that may have been derived from previously conducted test bench trials or determined by numerical models.

[0080] The first temperature measuring means 103 comprises a first temperature sensor. In one embodiment, the first temperature sensor comprises a thermistor, but it can alternatively also comprise a thermocouple. The flow velocity measuring means can comprise a flow velocity sensor, such as a mass airflow sensor, arranged on an air intake line 121 of the engine 101.

[0081] During operation, the engine 101 produces several pollutants; including various unburned hydrocarbons (HCs) such as C3H6, C7H8, C 10 H 22 Carbon monoxide (CO), unburned particulate matter (soot) and nitrogen monoxides, especially nitrogen oxide (NO) and nitrogen dioxide (NO2), generally referred to as NO x The exhaust system 106 comprises at least the first exhaust system component 104 for reducing harmful exhaust gases produced in the combustion chamber of the diesel engine 101 to harmless levels.

[0082] The first exhaust system component 104 can comprise a substrate with a catalyst designed to promote chemical reactions with gas components of the exhaust gases. For example, in the present embodiment, the first exhaust system component 104 comprises a nitrogen oxide trap (Lean NOₓ trap). x Trap, LNT), but can alternatively include a diesel oxidation catalyst (Diesel Oxidation Catalyst, DOC).

[0083] In the present embodiment, the system also includes the further exhaust system component 109, which comprises a diesel particulate filter (DPF). The DPF 109 is a wall-flow filter designed to filter out soot particles emitted by the engine in the exhaust gases. In some examples, a catalyst may be arranged on the inner walls of the wall-flow filter. A differential pressure sensor 117 is also present, which provides an output signal to the processor 113 indicating a pressure drop in the exhaust gases within the DPF. That is, the differential pressure sensor 117 provides a measure of the difference between the exhaust gas pressure at the outlet and inlet of the DPF.

[0084] System 106 also includes a first oxygen measuring device 115 in the form of a UHEGO (Universal Heated Exhaust Gas Oxygen) sensor, configured to supply values ​​of oxygen concentrations determined in the exhaust gases to the processor 113. In the present embodiment, the UHEGO sensor is arranged downstream of the second exhaust system component 108 and immediately upstream of the first exhaust system component 104. In the present embodiment, the system also includes a second oxygen measuring device 116, configured to supply values ​​of oxygen concentrations determined in the exhaust gases downstream of the DPF 109 to the processor 113. The second oxygen measuring device 116 can comprise a UHEGO sensor or another sensor configured to provide an indication of oxygen concentrations. In an alternative embodiment, the second oxygen measuring device 116 is arranged upstream of the DPF 109.

[0085] During operation, the engine 101 emits exhaust gases into the exhaust system 106, where the exhaust gas temperatures are measured by sensor 103 before they flow through the turbocharger 108. The oxygen concentration in the exhaust gases is then measured by the first UHEGO sensor 115 before the gases flow into the first exhaust component 104.

[0086] In the present embodiment, the first exhaust gas component is a nitrogen oxide trap (Lean NOₓ). x Trap, LNT) and features a substrate for storing and converting NO xin nitrogen and water vapor. During operation, adsorption achieves a high efficiency at a substrate temperature of 150 to 250 degrees Celsius. Desorption and reduction of NOx to nitrogen and water vapor are achieved when the LNT substrate temperature is 250 to 350 degrees Celsius and hydrocarbons are present. This is achieved during LNT regeneration by changing the diesel engine's operating mode from "lean" to "rich" (essentially by changing the air / fuel mixture). LNT regeneration is controlled by precise measurements of the exhaust gas oxygen content, as measured by the first and second UHEGO sensors 115 and 116. That is, the diesel injection required to effect regeneration is carried out by the diesel injectors 111 under the control of the processor 113, according to the signals received from the UHEGO sensors 115 and 116.

[0087] In the present embodiment, after passing through the LNT 104, the exhaust gases flow through the DPF 109. During operation, the DPF collects carbon particles (or soot), which tend to cause a pressure increase in the exhaust gases within the DPF. Therefore, at controllable intervals, the collected particulate matter is oxidized by raising the temperature of the DPF to higher temperatures (typically above 600 °C). To detect that an oxidation event (or regeneration event) is required, the particulate load in the DPF is monitored by a process in the processing unit 102, which uses inputs from the gas flow velocity through the DPF, the pressure drop in the DPF (via the pressure sensor 117), and the temperature of the DPF substrate.

[0088] To achieve the increased temperature required for DPF regeneration, the processor 113 is configured to control fuel injection events based on DPF substrate temperatures. As described in more detail below, the DPF substrate temperature is calculated using signals received from the temperature sensor 103, the gas flow velocity as measured by the flow velocity measuring device 105, and a mathematical model that models temperature changes in the exhaust gases as they flow through exhaust gas components between the sensor 103 and the DPF 109. In this example, if more than one exhaust gas component is located between the temperature sensor 103 and the DPF 109, an intermediate temperature can be calculated that approximates the temperature of the gases at the outlet of the turbocharger 108 and at the inlet of the LNT 104.The temperature of gases at the DPF inlet can then be calculated using this intermediate temperature.

[0089] This method for calculating approximate temperatures of the gas as it flows through the exhaust system provides very rapid indications of temperature changes and also allows for the use of fewer temperature sensors in system 106. For example, existing state-of-the-art systems include temperature sensors at the turbocharger outlet and at the LNT outlet; however, in the present system, no temperature sensors are arranged at these positions.

[0090] However, to achieve the required accuracy of the calculated temperatures, the system 106 can include a second temperature measuring device 118 arranged at the outlet of the DPF 109, which is configured to supply a third signal to the processor 113, indicating a third temperature of exhaust gases downstream of the DPF 109. In this case, the processor 113 can be configured to calculate a correction to the approximate temperature of the gases flowing into the DPF 109 according to this third signal. The corrected temperature can be determined by calculating the rate of heat loss from the exhaust gases as they flow through the DPF 109. The correction provides a more accurate approximation of the actual temperature of the gases flowing into the DPF, but reacts more slowly to changing temperatures. Therefore, the correction can only be performed periodically and less frequently than the calculation of temperatures based on the temperature signals received from the sensor 103.

[0091] An alternative system 106A implementing the present invention is described in Fig. 2 is shown in a vehicle 110. The 106A system has many common features with the 106 system. Fig. 1, which are designated with the same reference numerals. Thus, for example, the exhaust system 106A receives exhaust gases from a diesel engine 101. The temperature of the exhaust gases flowing from the engine is measured by a temperature sensor 103, which sends a signal to the processing unit 102. The processing unit 102 also receives a second signal, indicating the flow velocity of the exhaust gases, from a flow velocity measuring device 105.

[0092] The exhaust gases flowing from the engine pass through a turbocharger 108, an LNT 104 (or alternatively a diesel oxidation catalyst (DOC)) and a DPF 109 in a similar manner to the system of Fig. 1. The System 106A from Fig. System 2 further comprises a Selective Catalytic Reduction (SCR) module 201, which is located downstream of the DPF 109. System 106A also includes a urea supply 202, from which urea is injected into the exhaust gases via an injector 203 downstream of the DPF but upstream of the SCR module 201. During operation, the injected urea undergoes hydrolysis in the line upstream of the SCR module, and the remaining ammonia is stored on the active layers of the SCR module, which converts NOₓ. x in the SCR module in nitrogen and water and corresponds to the state of the art.

[0093] To ensure that the SCR module 201 functions correctly, the rate of urea injection is adjusted according to the temperature of the gases flowing into the SCR module and the rate of mass flow of NO into the SCR module. x designed. In state-of-the-art systems, NOx -Sensors for detecting NO flowing into the SCR module x can be used. In the present embodiment, however, the processing agent 102 is used to calculate the varying concentrations of NO. x , while the exhaust gases flow through the various components of system 106A, and in particular the concentrations of NO x , while the exhaust gases flow into the SCR module.

[0094] The calculations performed by the processing unit 102 use the previously described mathematical model, which is used to calculate the temperatures of the exhaust gases as they flow through the exhaust system components. The model and calculations use as input values ​​the concentrations of the pollutants produced by the engine 101, which are stored in the storage device 114 (comprehensive NOₓ concentration). x-concentration values), the oxygen concentrations measured by the UHEGO sensors 115 and 118, the calculated temperatures of the exhaust gases and exhaust system components, and the NO x -Sensor 222 received values. In particular, changes in NO x -Concentration calculated by the conversion through the LNT 104 to determine the concentration of NO arriving at the SCR module x to determine.

[0095] In the embodiments of Fig. 1 and Fig. 2 uses the mathematical model of thermodynamics and chemical kinetics to determine the temperatures of the gaseous and solid components of the systems and to calculate the reaction rates and the molar-to-mass balance of the exhaust gases. This reduces the calibration time, as the model inputs relating to the system definition serve as the calibration. The model consists of submodules that can be applied to flow-through catalysts (diesel oxidation catalysts, selective catalytic reduction catalysts, nitrogen oxide traps) or wall-flow particulate filters (diesel particulate filters). Each submodule can consist of a gas-phase model, a solid-phase model, and a chemical kinetics model. Furthermore, a submodule can include a pressure drop model.

[0096] The submodules for flow catalysts model the processes involved in capturing and releasing NO. xThe thermodynamics and chemical kinetics linked to the conversion of hydrocarbons (HCs) and carbon monoxide (CO) and the heat exchange on the catalyst surface are analyzed. The model consists of a thermal model, which in turn comprises solid-phase, gas-phase, and pressure-drop submodules, and a chemical model that attempts to account for the storage and release of NO. x The model describes the chemical reactions of hydrocarbons (HC), carbon monoxide (CO), oxygen (O2), and ammonium (NH3). A resulting advantage is the ability to determine the chemical equilibrium of these substances. The model is adaptable and can be used for DOC, LNT, or SCR systems.

[0097] Similarly, the submodules for wall-flow filters model the thermodynamics and chemical kinetics associated with the capture, release, and conversion of soot and the heat exchange on the filter surface. Some DPFs may incorporate a catalyst interlayer to aid the conversion of hydrocarbons and carbon monoxide. Accordingly, the submodule for the catalytic DPF may include an additional set of equations in the chemical kinetics model, similar to those for a catalyst component, such as a DOC. The model consists of a thermal model, which in turn comprises solid-phase, gas-phase, and pressure drop submodules, and a chemical model that attempts to describe the heat release from the conversion of the substances (soot) and the resolution of the chemical balance (mass / mol) of these substances.The thermal model is similar to the wall-flow catalyst model; however, the sub-module for the DPF may differ from other modules by additional modeling of soot storage and filtration, as well as an additional pressure drop expression that represents the pressure drop due to the flow of gas through the porous wall and its dependence on the soot load of the filter.

[0098] The mathematical model also includes a sub-module for modeling the turbocharger 108. This sub-module can use the temperature measured by the temperature sensor 103 and the flow velocity as measured by the flow velocity measuring device 105 as inputs and calculates heat loss and pressure drop in the turbocharger to determine the temperature of the exhaust gases as they flow out of the turbocharger.

[0099] A schematic diagram illustrating the general function of the submodules of the mathematical model supplied by the device 100 is shown in Fig. 3 shown. The schematic diagram of Fig. Figure 3 shows a submodule of the mathematical model that models a single exhaust system component 301, such as the first, second, third, or fourth exhaust system component 104, 108, 109, and 201. However, as explained in more detail for the turbocharger 108, temperature drop and pressure drop calculations are performed using a different set of equations than those used for the catalysts 104, 109, and 201.

[0100] A stream of exhaust gases (represented by arrow 302) flows into an inlet 303 of component 301 at a temperature T g1 , a pressure P g1 and a quantity C1 of component exhaust gas concentrations. For example, the quantity C1 can represent an initial value C A1 , indicating the concentration of NO x, a second value C B1 , indicating the concentration of carbon monoxide, a third value C C1 referring to the concentration of a known hydrocarbon emitted by the engine, a fourth value C C2 , indicating the concentration of a second known hydrocarbon, etc., include.

[0101] The temperature T g1 , the pressure P g1 and the quantity C1 of component gas concentrations may have been determined from calculations performed with respect to a preceding submodule that models a preceding exhaust system component in the system. For example, if component 301 is LNT 104, the temperature T g1 , the pressure P g1 and the quantity C1 in previous calculations with respect to the turbocharger 108 may be values ​​determined, or if component 301 is the DPF 109, the temperature T can be g1 , the pressure P g1and the quantity C1 in previous calculations with respect to the LNT 104 could be the values ​​determined. Alternatively, as with the turbocharger 108, the temperature T can be g1 a measured value, and the quantity C1 can consist of values ​​previously stored in the storage device 114. The pressure at the turbocharger inlet can be determined by a pressure sensor arranged next to the temperature sensor 103. In an alternative embodiment, a backward calculation of pressures can be performed, in which the pressure values ​​upstream of each component are determined from the pressure values ​​downstream of each component as a function of flow velocity and local temperature, and on the basis that the pressure at the outlet of the system 106 or 106A corresponds to atmospheric pressure.

[0102] The model's submodules calculate the temperature change of the exhaust gases and, depending on the modeled exhaust system component, the pressure change and changes in component gas concentrations as the exhaust gases flow through exhaust system component 301 to change the temperature T. g2 , the pressure P g2 and to determine the quantity C2 of component gas concentrations at the outlet 305 of the exhaust system component 301. These new values ​​for the temperature T g2 , the pressure P g2 and the amount C2 of component gas concentrations can then be used as input values ​​for the next submodule corresponding to the next downstream exhaust system component in the system. For example, if the temperature T g2 , the pressure P g2 and once the quantity C2 of component gas concentrations for the first exhaust system component 104 has been determined, these are subsequently used as input values ​​for the temperature T g1 , the pressure Pg1 and the amount of C1 of component gas concentrations for the next exhaust system component 109 is used.

[0103] The mathematical model calculates the heat, Q CONV , which is transferred to the substrate 304 of the exhaust system component 301 from the exhaust gases by convection, and calculates the heat, Q COND , which is dissipated from the substrate to the surrounding material. For some components (such as DOC, LNT, SCR or DPF) it also calculates the heat, Q. REACT , which is generated by chemical reactions with the individual exhaust gases as they flow through the exhaust system component 301.

[0104] Some components, including a catalyst substrate, can be electrically heated during the warm-up phase when the engine is cold and the catalyst response time needs to be reduced. Accordingly, the model can also measure the heat, Q EL , take into account the electrical heating.

[0105] The calculations for each submodule are performed repeatedly, allowing temperature changes of the gases and substrates of the components to be calculated in real time. Each iteration of the calculations for modeling an exhaust system component uses a previously calculated temperature of its substrate. The substrate of an exhaust system component can gain or lose temperature due to the convection of exhaust gases, chemical reactions, and heat conduction to surrounding materials. From the rates of change of heat gained and lost by the substrate, the mathematical model can calculate a rate of rise of the substrate temperature and / or a rise in the substrate temperature (ΔT). bThe temperature is calculated within a defined period (e.g., 100 ms) according to the repetition of the calculation. By adding the temperature increase to an existing temperature, a new substrate temperature can be calculated, which can then be used in the next repetition of the calculation for the submodule.

[0106] Equations that can be used by the processing agent to model the gas phase in a catalyst exhaust system component such as the first component 104 are in Fig. 4 shown. Equation 1 (ρgCpgvg∂Tg∂x=−h⋅Sfε⋅(Tg−Tb)+Q˙react) brings (on the left side of the equation) the heat gained from the exhaust gases as they flow through the component into an equation (on the right side of the equation) with the rate of heat transferred from the gases to the substrate of the component plus the rate at which heat is added to the exhaust gases by chemical reactions (Q̇). react ).

[0107] The calculation of the exhaust gas temperature is done using the equations of Fig. Equation 4 was carried out, taking into account the geometry of the catalyst, in particular the channel shape and the catalyst type, and the heat transfer from the gas to the solid substrate. Equation 1 allows the rate of change of the gas temperature with respect to the length, x, of the catalyst to be determined. On the left side of Equation 1, ρ represents g represents the density of the gas (as a function of temperature), C pg is the specific heat capacity of the gas and v gis the velocity of the gas (determined as a function of geometry and mass flow rate). The right-hand side of the equation consists of the coefficient of heat transfer from the gas to the catalyst substrate (h), the temperature difference between the gas and the substrate (Tg in each case). g , T b ), the heat of reaction (Q̇) generated by exothermic reactions react , determined in the chemical kinetic model) and a ratio between the form factor of the substrate and its porosity (Sfε) The latter expression (Sfε) describes the total area over which heat is exchanged between gas and substrate, taking into account the intermediate layer (which reduces the substrate's inlet area) and the shape of the channels (square, hexagonal, etc.).

[0108] The heat transfer coefficient can be determined by equation 2 (h = Nu ·λ). g / d h) are determined, where Nu is the dynamic Nusselt number, λ g the gas conductivity and d h represents the hydraulic diameter of the cell. The Nusselt number can be calculated using equations 3-5, which define the shape of the channel for the laminar Nusselt number (Nu). L ) take into account. In equations 3 (Nu = Nu L · [(1 + n1) bh - bh · n1 · (1 + n1) bh-1 ]) and 4 (n1 = ah / G zD ) are ah equal to 0.095 and bh equal to 0.45, where ah and bh are the local Hawthorne correction parameters. Equation 1 is part of a system of equations that close the energy balance. The substrate temperature is calculated using Equation 6, which is discussed in the following section.

[0109] Equation 1 allows the processing agent to determine the rate of change of the gas temperature (∂T). g / ∂x) via a “control volume”. In one embodiment, the volume can encompass the entire length of a catalyst, where the change in exhaust gas temperature due to the exhaust system component is then determined by multiplying the rate of change in gas temperature (∂T) by the exhaust system component. g / ∂x) can be calculated using the length of the catalyst. Alternatively, the model can discretize the equation over a number of smaller elements to increase accuracy (although this increases the computational effort).

[0110] Equations that can be used by the processing agent to model the solid phase in a wall-flow or flow-through catalyst exhaust system component such as components 104, 109, 201 are in Fig. 5 shown. Equation 6 (ρb⋅Cpb⋅∂Tb∂t=λb,x∂2Tb∂x2+λb,y∂2Tb∂y2+Q˙conv+Q˙react+Q˙el) This equation combines the rate of increase of heat contained in the substrate with the rate of heat lost from the substrate by conduction to the surrounding material (such as insulation), plus the rate of heat gained from exhaust gases by convection, plus the rate of heat generated by chemical reactions, plus any heat gained by electrical heating.

[0111] The temperature of the substrate, insulation, and canning can be determined using Equation 6, although it is applied independently to each subcomponent. For brevity, only the calculation of the substrate temperature is described here. The substrate temperature depends on a large number of factors and heat transfer mechanisms.

[0112] In a flow-through catalyst, the substrate and interlayer heat capacity can be taken into account, where the specific heat capacity of the entire solid (C) pb ) is a function of the components of the solid.

[0113] According to equation 7 (ρ b = ρ w · ε w + ρ c · ε c ) the density of the solid catalyst is equal to the product of the density of the interlayer material, ρ w , and the volume fraction of the interlayer material, ε w , added to the product of the density of the substrate material, ρ c , and the volume fraction of the substrate material, ρ c In equation 8 (ρ c · ε c = m c ) is the product of the density of the substrate material, ρ c , and the volume fraction of the substrate material, ρ c , equal to the intermediate layer load m c .

[0114] Thus, as shown in equation 9 (ρ b · C pb = ρ w · ε w · C pw + C pc · ε c · ρ cBy considering all components, the heat capacity of the solid in a flow-through catalyst can be determined as the sum of the heat capacity of the substrate added to the heat capacity of the interlayer. ρ w denotes the density of the interlayer material, ε w denotes the volume fraction of the interlayer material and C pw denotes the specific heat capacity of the interlayer. Similarly, ρ denotes c the density of the substrate material, ε c denotes the volume fraction of the substrate material and C pc denotes the specific heat capacity of the substrate material.

[0115] Equation 6 again shows that the rate of change of temperature with respect to time (∂Tb∂t) is a function of the thermal mass of the solid and other heat flows. The right-hand side of the equation consists of the heat conducted axially through the catalyst. (λb,x∂2Tb∂x2), the heat conducted from the center to the edge through the catalyst (λb,y∂2Tb∂x2) and the one through convection (Q̇ conv ), heat of reaction (Q̇ react ) and electrical heating (Q̇ el ) (if any) exchanged heat. λ b,x and λ b,y The thermal conductivities of the catalyst are given in the axial and radial directions, respectively. The convective heat transfer is given in equation 11 (Q conv = h · S F · (T g - T b )) described and explained in relation to equation 1, while the heat of reaction (Q̇ react ) below in relation to Fig. 6 is described.

[0116] Using equation 6 of Fig. 5. Processing agent 102 can calculate the rise in substrate temperature over a defined period. This can be done by calculating the sum of the expressions on the right-hand side of equation 6 and dividing by the heat capacity to obtain the rate of temperature change with respect to time (∂T). b to determine / ∂t), and then to multiply this rate of temperature change by the defined period.

[0117] Equations that can be used by processing agent 102 to model the chemical reactions that take place in exhaust system components such as component 104 are in Fig. Figure 6 illustrates this. The chemical model solves the Arrhenius equations for specific exhaust gases to calculate the reaction rate, heat released, and mole / mass balance. The general Arrhenius equation (14) is used for all substances considered in the model with specific pre-exponential factors (A) and activation energy (E) for each pollutant. Equation 14 (K(t) = A · exp(-E / (RT))) is completed with the substrate temperature (T) and the specific gas constant R, determined from Equation 6. This allows the calculation of the Arrhenius expression K(t), which is then multiplied by the concentration of the converted substances ([C A ]) is multiplied to determine the reaction rate of the substances (R) k ) as in equation 13 (R k = K(t) · [C A ]) shown to calculate. The heat of reaction determined for all substances is calculated using equation 12 (Q̇). react = SF · Σ K (R k dH k)) determined, where the form factor of the catalyst (SF) is multiplied by the sum of the heat released for each individual substance (Σ K (R k dH k )) is multiplied. Here, dH represents k This represents the rate of heat of reaction generated by the conversion of one mole of each k substance. Once the heat of reaction is determined, it can be used to complete the calculation of substrate and gas temperature (using equations 1 and 6) and to determine the efficiency of the catalytic process via the reaction rate.

[0118] Equations that can be used by processing agent 102 to model pressure drops in exhaust system components such as component 104 are in Fig. Figure 7 illustrates this. Each component of the exhaust system can be accompanied by a set of equations that allow the calculation of a pressure drop in flow-through or wall-flow catalysts. Factors that can be considered include the duct pressure drop, determined by Equation 15. (dPdx=−28.5⋅μ⋅vgdh2) and 16 (v g = mfr / (ρ g · A monolith · ε)), the abrupt drop in contraction and expansion pressure, ΔP contraction and ΔP expantion , as in equation 17 (ΔP contraction = (1.1 - 0.4 · C x ) · (ρ g · v g ) 2 / 2), 18 (ΔP expantion = (1 - C x ) · (ρ g · v g ) 2 / 2) and 19 (Cx=dh22⋅(d+ww)2) shown, and the inlet / outlet diffuser pressure drop, ΔP diffuser , as in equation 20 (ΔPdiffuser=(1−Ain / Aout)2⋅mfr2 / (ρin⋅Asec2)) shown. All these pressure losses can then be summed to obtain an accurate calculation of the total pressure drop in the component. Furthermore, the Darcy pressure drop can be taken into account for wall-flow catalysts. The Darcy pressure drop is shown in Fig. 7 is not shown, but is well known according to the state of the art.

[0119] In the equations of Fig. 7 is µ the dynamic viscosity; v g is the speed of the gas; d h is the hydraulic diameter; mfr is the mass flow rate; ρ g is the density of the gas; A monolith is the hydraulic diameter of the substrate cell; ε is the porosity of the coated monolith; C x is the calibration parameter (usually 1); d is the overall diameter of the substrate cell; w w is the substrate wall thickness; A in is the total inlet area of ​​the monolith; A out is the total outflow of the monolith; and Asec is the area of ​​the section in which a specific calculation is performed.

[0120] As previously described, the processing means 102 can be configured to calculate a correction to the approximate temperature of gases flowing into the DPF 109 according to the third signal received from a temperature measuring means arranged downstream of the DPF. The corrected temperature can be determined by calculating a rate of heat loss from the exhaust gases during their flow through the DPF 109. An equation generated by the processor 113 to determine the rate of temperature change (∂TIN∂t) The equation that can be used at the DPF inlet is equation 23. (∂TIN∂t=∂TOUT∂t+∂(Q˙m˙.cp)∂t) in Fig. Figure 8 shows the rate of temperature change. (∂TIN∂t) The inlet is equal to the rate of temperature change. (∂TOUT∂t) at the outlet plus a heat flow rate ∂(Q˙m˙.cp)∂t, which can be calculated at each time step of the mathematical model. (Here, Q represents all heat sources and heat sinks into and out of the DPF control volume, ṁ represents the mass flow through the DPF, and C p (represents the heat capacity of the exhaust gases.)

[0121] As previously described, the mathematical model uses the exhaust gas temperature sensor 103 upstream of a turbocharger (108 in Fig. 1 and Fig. 2) as one of the inlet limit conditions, while a temperature sensor 118 downstream of the DPF can be used as a means of correcting the overall temperature profile. The system 106, 106A can operate without a temperature sensor between the turbocharger 108 and the LNT 104 (or a DOC in the position of the LNT), since a numerical turbine model from the processor 113 can be used to calculate the heat losses and pressure drop in the turbocharger. The turbocharger can be modeled with a pipe model and the energy balance can be calculated using the equations of Fig. 9 will be dissolved.

[0122] In equation 24 (TOUT=m˙⋅Cp⋅TIN−hEG,Pipe⋅A⋅(TIN−Twall)m˙⋅Cp) ṁ is the mass flow rate in the pipe, Cp is the gas heat capacity, A is the surface area of ​​the pipe wall, and h EG,pipe is the coefficient of heat transfer between the gas and the pipe wall. The heat transfer coefficient can be calculated using equation 25. (hEG,Pipe=NuEG⋅kEGd) to be carried out, where d is the diameter of the pipe, Nu EG represents the Nusselt number in the pipe and k EG The thermal conductivity of the exhaust gas in the pipe is T. IN and T OUT are the temperatures of gases at the inlet and outlet of the turbocharger and T wall is the temperature of the turbocharger wall.

[0123] Furthermore, the energy balance can be calculated by determining the temperature of the wall as in equation 26. (TWall,t=t=KI⋅Q˙EG,Pipe−Q˙Pipe,Envm⋅Cp⋅dt+TWall,t=t−1) to be completed, carried out by discrete integration, where K I The integral gain is. Q̇ EG,Pipe and Q̇ Pipe,Env represent the heat energy flowing from the exhaust gases into the pipe wall and from the pipe wall into the environment, and are calculated using equation 27 (Q̇). Pipe,Env = h Pipe,Env · A · (T wall - T Env )) and 28 (Q̇ EG,Pipe = h EG,Pipe · A · (T in- T wall )) determined. h Pipe,Env denotes the coefficient of heat transfer between the pipe wall and the environment.

[0124] A flow diagram of a process 1000 for controlling the injection in a diesel engine is in Fig. 10 is shown. The procedure 1000 can be carried out by processor 113 of Fig. 1 or Fig. 2. Method 1000 comprises receiving a first signal from a first temperature sensor indicating a first temperature of exhaust gases emitted by a diesel engine at a first position upstream of a first exhaust system component configured to provide a passage for exhaust gases in block 1001. For example, the first signal may be a temperature sensor 103 of Fig. 1 or Fig. 2. The supplied signal will be the first exhaust system component, and the first component can be the LNT 104 of system 106 or 106A.

[0125] Method 1000 also includes, in block 1002, the reception of a second signal from a flow velocity sensor, indicating the flow velocity of the exhaust gases emitted by a diesel engine. For example, the second signal from the flow velocity sensor 105 can be Fig. 1 or Fig. 2. As previously described, the flow velocity sensor 105 can be located on the inlet side of the engine, but provides a signal indicating the flow velocity of the exhaust gases expelled by the engine. For example, the mass flow rate from the engine can be calculated from the mass flow rate into the engine using state-of-the-art methods.

[0126] Method 1000 also includes in block 1003 the calculation of an approximate value from the first signal and the second signal, where the approximate value indicates a second temperature of exhaust gases downstream of the first exhaust system component. The second temperature can also be an approximation of the exhaust gas temperature at a position between the LNT 104 and the DPF 109. Fig. 1 or Fig. 2, but alternatively it can also be an approximation of the exhaust gas temperature at a position downstream of the DPF or upstream of the LNT. (In the latter case, the first exhaust system component 104 can be the turbocharger 108.)

[0127] Method 1000 also includes in block 1004 the provision of an output signal for controlling at least one diesel injector according to the calculated approximate value. For example, the diesel injectors 111 of engine 101 can be controlled according to the calculated approximate value to generate a diesel flow velocity to achieve a rich mixture for regenerating a DPF or LNT.

[0128] An example of processes that can be carried out in block 1003 is shown in the flowchart of Fig. Figure 11 illustrates this. In block 1101, procedure 1000 includes calculating a rate of heat loss from the exhaust gases as they flow through the first exhaust system component. For example, this can be done as before with respect to equation 1 of Fig. 4 described can be achieved.

[0129] As in Fig. As shown in Figure 12, the process of Block 1101 can include calculating a rate of heat loss from the exhaust gases to a substrate of the first exhaust system component as the exhaust gases flow through the first exhaust system component (as shown in Block 1201). For example, the rate of heat loss to the substrate can be calculated as described previously with respect to the right-hand side of Equation 1. It can also (as shown in Block 1202) include calculating a rate at which heat is conducted away from the substrate to the surrounding material, as with respect to Equation 6 of Figure 12. Fig. 5 described.

[0130] As in Fig. As shown in Figure 11, the procedure 1000 can also include in block 1102 the calculation of a rate of heat generated by chemical reactions during the flow of exhaust gases through the first exhaust system component.

[0131] For example, this can be as in relation to the equation of Fig. 6 will be carried out as described.

[0132] Method 1000 can also include, in block 1103, the calculation of concentrations of gas components flowing from the first exhaust system components. For example, this can also be done as in relation to the equation of Fig. 6 will be carried out as described.

[0133] Method 1000 can also include, in block 1104, the calculation of a pressure drop in the exhaust gases between the pressure of gases at an inlet of the first exhaust system component and an outlet of the first exhaust system component. For example, this can be done using one or more of the equations of Fig. 7 will be carried out as described.

[0134] Method 1000 can be applied to a system in which two or more exhaust system components are arranged between a position of a measured temperature and a position for which the approximate temperature is calculated in order to control diesel injection. For example, in the system of Fig. 1. A turbocharger 108 and an LNT are arranged between the position of the temperature sensor 103 and a position between the LNT and the DPF, for which an approximate value is required. In such cases, block 1003 of method 1000 can perform the processes of Fig. 13. Here, procedure 1000 comprises calculating an intermediate value from the first signal and the second signal, wherein the intermediate value indicates an intermediate temperature of exhaust gases at a position downstream of a second exhaust system component and upstream of the first exhaust system component, in block 1301. Subsequently, the procedure in block 1302 comprises calculating the approximate value indicating a second temperature from the intermediate temperature.

[0135] Procedure 1000 can also be used in Fig. The 14 processes shown are for improving the accuracy of the approximation for the second temperature. The processes of Fig. 14 can be performed regularly in addition to blocks 1001 to 1004 to regularly improve the accuracy of the approximation for the second temperature. The processes of Fig. 14 can occur with the same or a lower frequency than the blocks of Fig. 10 will be carried out.

[0136] In block 1401 of Fig. In section 14, a third signal is received, indicating a third temperature of exhaust gases downstream of another exhaust system component, the third exhaust system component being located downstream of the first exhaust system component. In block 1402, the method includes calculating a correction to the approximate value according to the third signal. For example, as with respect to Fig. 1 and Fig. 2 describes how the third signal is supplied by a temperature sensor 118 located downstream of a DPF 109 to correct an approximate temperature of the gases flowing into the DPF. This correction process can be described as before with respect to Fig. The calculation described in section 8 involves calculating the rate of heat loss from the exhaust gases as they flow through the subsequent exhaust system component. (For example, the rate of heat loss from the exhaust gases as they flow through the DPF can be calculated.)

[0137] Within the scope of this disclosure, it should be noted that the processing means described herein may each comprise a control unit or a computing device with one or more electronic processors. A vehicle and / or a system thereof may comprise a single control unit or electronic control device, or alternatively, different functions of the control device(s) may be performed or incorporated in different control units or devices. A set of instructions may be provided which, when executed, cause the control device(s) or control unit(s) to implement the control techniques described herein (including the described method(s)).The set of instructions can be embedded in one or more electronic processors, or alternatively, the set of instructions can be provided as software that is executed by one or more electronic processors. For example, a first control device can be implemented in software that runs on one or more electronic processors, and one or more other control devices can also be implemented in software that runs on one or more electronic processors, optionally the same one or the same multiple processors as the first control device. It is understood, however, that other arrangements are also useful, and that this disclosure is therefore not intended to be limited to any particular arrangement.In any case, the set of instructions as described above can be embedded in a computer-readable storage medium (for example, a non-transient storage medium), which may include any mechanism for storing readable information by a machine or electronic processors / computer device, including without limitation: a magnetic storage medium (for example, a floppy disk); an optical storage medium (for example, a CD-ROM); a magneto-optical storage medium; a Read Only Memory (ROM); a Random Access Memory (RAM); a erasable programmable memory (for example, an EPROM and EEPROM); a flash memory; or electrical or other types of medium for storing such information / instructions.

[0138] In this usage, "module" refers to a part of software that is used with other modules to generate a complete mathematical model of an exhaust system. Each module typically corresponds to a single component of the exhaust system.

[0139] The in Fig. The 10 to 14 blocks shown can represent steps in a procedure and / or sections of code in computer program 151. The representation of a particular order for the blocks does not necessarily imply that there is a required or preferred order for the blocks, and the order and arrangement of the blocks can be varied. Furthermore, it may be possible for some steps to be omitted.

[0140] Although the embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be understood that changes can be made to the examples given without deviating from the scope of the invention as claimed in the accompanying claims.

[0141] The features described in the preceding description can be used in combinations that differ from the combinations explicitly described.

[0142] Although functions have been described with reference to certain features, these functions can be performed by other functions, regardless of whether they have been described or not.

[0143] Although features have been described with reference to specific embodiments, these features may also be present in other embodiments, regardless of whether they have been described or not.

[0144] While the foregoing description has attempted to draw attention to those features of the invention which were considered to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or patentable combination of features referred to above and / or shown in the drawings, regardless of whether particular importance has been attached to them or not.

Claims

[1] Device (100) for controlling an aftertreatment system of an internal combustion engine (101), wherein the device (100) comprises a processing means (102) configured to: Receiving a first signal from a first temperature measuring device (103), indicating a first temperature of exhaust gases emitted by an internal combustion engine (101) at a first position upstream of a first exhaust system component (104) designed to provide a passage for exhaust gases; Receiving a second signal from a flow velocity measuring device (105), indicating a flow velocity of the exhaust gases emitted by the engine; Calculating an approximate value at least from the first signal and the second signal, wherein the approximate value indicates a second temperature of exhaust gases at a position downstream of the first exhaust system component (104), wherein calculating the approximate value comprises: Receiving a stored value of a concentration for each of a multitude of exhaust gases and calculating a rate of heat generated by chemical reactions of the exhaust gases during the flow of the exhaust gases through the first exhaust system component (104); and Providing an output signal to control the post-treatment system according to the calculated approximate value. [2] Device (100) according to claim 1, wherein the output signal is supplied to fuel injection medium to control a rate of fuel injection. [3] Device (100) according to claim 1 or claim 2, wherein the processing means (102) comprises a processor (113); the first temperature measuring means (103) comprises a first temperature sensor and the flow velocity measuring means (105) comprises a flow velocity sensor (105). [4] Device (100) according to one of claims 1 to 3, wherein the first exhaust system component (104) comprises a substrate (250-350) comprising a catalyst designed to promote chemical reactions of gas components of the exhaust gases. [5] Device (100) according to any one of claims 1 to 4, wherein the first exhaust system component (104) is a nitrogen oxide trap (Lean NOₓ trap). x includes a trap, LNT) or a diesel oxidation catalyst (Diesel Oxidation Catalyst, DOC). [6] Device (100) according to one of claims 1 to 5, wherein the processing means (102) is designed to detect a pressure drop in the exhaust gases between an inlet of the first exhaust system component (104) and an outlet of the first exhaust system component (104). [7] Device (100) according to one of claims 1 to 6, wherein a second exhaust system component comprises a turbocharger (108). [8] Device (100) according to one of claims 1 to 7, wherein a correction of the approximate value is determined by calculating a rate of heat loss from the exhaust gases during the flow of the exhaust gases through a further exhaust system component (109). [9] Device (100) according to one of claims 1 to 8, wherein the processing means (102) for calculating a correction of the approximate value by determining the rate of change of temperature at the inlet to the further exhaust system component (109) from the rate of change of temperature at the outlet of a further exhaust system component (109) and a heat flow rate supplying heat to the further exhaust system component (109) and dependent on cooling elements of the further exhaust system component (109). [10] Device (100) according to one of claims 1 to 9, wherein the processing means (102) is designed to calculate the approximate value regularly with a first frequency and to calculate a correction. [11] Device (100) according to any one of claims 1 to 10, wherein a further exhaust system component (109) comprises a diesel particulate filter (DPF). [12] Device (100) for controlling an aftertreatment system of an internal combustion engine (101) according to one of the preceding claims, wherein: the processing means (102) comprises an electronic processor (113) with an electrical input for receiving first and second signals and an electronic storage device (114) electrically coupled to the electronic processor (113) in which instructions are stored; wherein the processor (113) is configured to access the storage device (114) and to execute the instructions stored therein, such that it is configured to receive the first and second signals, calculate the approximate value indicating the second temperature, and control at least one fuel injector according to the approximate value. [13] System (106, 106A) for treating exhaust gases from a diesel engine (101), wherein the system (106, 106A) comprises the device (100) according to one of the preceding claims and a plurality of exhaust system components designed to provide a passage for the exhaust gases, wherein the plurality of exhaust system components comprises the first exhaust system component (104). [14] Vehicle comprising a diesel engine (101) and a system (106, 106A) according to claim 13. [15] Method for controlling the exhaust aftertreatment for an internal combustion engine (101), the method comprising: Receiving a first signal from a first temperature sensor indicating a first temperature of exhaust gases emitted by an internal combustion engine (101) at a first position upstream of a first exhaust system component (104) designed to provide a passage for exhaust gases; Receiving a second signal from a flow velocity sensor (105), indicating a flow velocity of the exhaust gases emitted by the engine; Calculating an approximate value at least from the first signal and the second signal, wherein the approximate value indicates a second temperature of exhaust gases downstream of the first exhaust system component (104); Providing an output signal to control the exhaust aftertreatment according to the calculated approximate value; where calculating the approximate value includes: Receiving a stored value of a concentration for each of a multitude of exhaust gases and calculating a rate of heat generated by chemical reactions of the exhaust gases during the flow of the exhaust gases through the first exhaust system component (104). [16] Method according to claim 15, wherein the output signal is supplied to fuel injectors to control a rate of fuel injection. [17] Method according to one of claims 15 to 16, wherein the calculation of the approximate value comprises calculating a pressure drop in the exhaust gases between the pressure of gases at an inlet of the first exhaust system component (104) and an outlet of the first exhaust system component (104). [18] Method according to any one of claims 15 to 17, wherein calculating a correction comprises calculating a rate of heat loss from the exhaust gases during the flow of the exhaust gases through a further exhaust system component (109).

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