Method of performing exhaust aftertreatment on an internal combustion engine of a vehicle

Abstract

A method of performing exhaust aftertreatment of an internal combustion engine (4) of a vehicle having an exhaust system (20), the method comprising the steps of starting (100) the internal combustion engine (4), specifying (200) a target value of a combustion air ratio (l) within an exhaust space (20') of the exhaust system (20), and adjusting (300) a current combustion air ratio (l) within the exhaust space (20') of the exhaust system (20) to the target value of the combustion air ratio (l) within the exhaust space (20') of the exhaust system (20), wherein the adjustment (300) of the current combustion air ratio (l) is implemented via a supply of secondary air by means of a first controllable secondary air source (10) in a normal mode (I) and is performed via a supply of secondary air by means of a second controllable secondary air source (22, 30) in an emergency mode (II).

Description

Technical Field

[0001] The present invention relates to a method and system for performing exhaust aftertreatment on an internal combustion engine of a vehicle, and a vehicle including such a system. Background Technology

[0002] Methods and systems for performing exhaust aftertreatment on internal combustion engines are known in the prior art. Due to increasingly stringent exhaust standards, automakers have a growing need to develop and adapt such systems and methods for exhaust aftertreatment. Various methods, such as introducing secondary air to reduce pollutant concentrations, are known in the prior art to meet required exhaust standards and provide internal combustion engines with the lowest possible emissions.

[0003] However, existing exhaust aftertreatment systems generally operate only in a static idling mode, during which they ensure maximum heat output and minimum NO through a rich fuel mixture in the combustion chamber via secondary air reaction. X Raw emissions. In contrast, under load, secondary air operation is impossible, or only possible to a very limited extent. Furthermore, known systems for exhaust aftertreatment generally lack any means to perform exhaust aftertreatment in emergency modes, where, for example, the onboard battery used for power supply has too little charging capacity, or requires air pressure higher than the base pressure supply, making optimal exhaust aftertreatment impossible under such conditions. Summary of the Invention

[0004] Therefore, the problem solved by the present invention is to at least partially overcome the shortcomings described above. Specifically, the problem of the present invention is to provide a system or method that allows for a simple and cost-effective method for quickly, reliably, and efficiently treating the exhaust gas of an internal combustion engine in a vehicle, thereby ensuring low-emission operation of the internal combustion engine.

[0005] The aforementioned problems are addressed by the method of the present invention for performing exhaust aftertreatment on an internal combustion engine of a vehicle with an exhaust system, the system of the present invention for performing exhaust aftertreatment on an internal combustion engine of a vehicle with an exhaust system, and the vehicle of the present invention including the system for performing exhaust aftertreatment on an internal combustion engine of a vehicle with an exhaust system. The technical features and details disclosed in conjunction with the method according to the present invention are naturally applicable in conjunction with the system according to the present invention and the vehicle according to the present invention, and vice versa, such that reference is always, or can always, to the disclosures regarding various aspects of the present invention.

[0006] According to the present invention, a method for performing exhaust aftertreatment on an internal combustion engine of a vehicle having an exhaust system is provided. The method according to the present invention includes the following steps: starting the internal combustion engine, specifying a target value for the combustion air ratio within the exhaust space of the exhaust system, and adjusting the current combustion air ratio within the exhaust space to the target value. According to the present invention, the adjustment of the current combustion air ratio is proposed to be implemented under normal operation by means of a first controllable secondary air source via the supply of secondary air, and under emergency operation by means of a second controllable secondary air source via the supply of secondary air.

[0007] Therefore, according to the present invention, this method is designed to facilitate particularly rapid and effective exhaust aftertreatment in normal mode by means of a first controllable secondary air source via the supply of secondary air, which can also be performed under vehicle load or during driving operations. Simultaneously, this method is designed to facilitate ensuring the supply of secondary air by means of a second controllable secondary air source, and thus ensure particularly reliable exhaust aftertreatment even in emergency mode. By means of a controllable secondary air source, combined with preferably provided software functionality and operating strategies, in addition to effectively reducing NO... X In addition, it is particularly likely to effectively reduce hydrocarbon (HC) and CO. This method can also preferably achieve the parameters for ignition capability and the optimal λ operating strategy for minimum emissions.

[0008] It should be understood that the steps of the method according to the invention can be performed in a specified order or optionally deviate from the specified order. It should also be understood that individual, multiple, or all steps of the method according to the invention can be repeated, for example, cyclically. In the context of the invention, exhaust aftertreatment should be understood in particular as a method in which combustion gases are removed from the combustion chamber by mechanical, catalytic, or chemical means. Preferably, the target value of the combustion air ratio can be adjusted within the exhaust space by adjusting the target value of the combustion air ratio within the combustion chamber. Vehicle can preferably be understood as a motor vehicle, such as a bus or truck. However, the use of this method in aircraft, such as aircraft or airships, is also contemplated. In the context of the invention, the combustion air ratio is preferably understood as the mass ratio between air and fuel, which is preferably determined by means of a λ sensor of the oxygen content in the exhaust. When the combustion air ratio is 1, there is a stoichiometric ratio between the amount of air and the amount of fuel, such that all fuel molecules can fully react with atmospheric oxygen. In contrast, a combustion air ratio <1 indicates so-called fuel-rich or λ-rich, and a combustion air ratio >1 indicates so-called fuel-lean or λ-lean. Therefore, the corresponding combustion air ratio in the exhaust space preferably indicates the so-called rich or lean exhaust λ. According to the invention, the normal mode can be particularly understood as the operation of the exhaust aftertreatment system, wherein the energy for exhaust aftertreatment is provided by the vehicle battery. In contrast, the emergency mode according to the invention can be particularly understood as the operation of the exhaust aftertreatment system, wherein the energy for exhaust aftertreatment is no longer provided by the vehicle battery, for example because the vehicle battery no longer has sufficient charging capacity. Similarly, the normal mode can be understood as referring to the state of the exhaust space, wherein the basic pressure supply is sufficient. Therefore, the emergency mode can be understood as the state of the exhaust space, wherein the basic pressure supply is no longer sufficient.

[0009] Regarding the most efficient and universal exhaust aftertreatment, it is particularly relevant in the current context to propose continuously adjusting the supply of secondary air during full-load vehicle operation. For this purpose, the first and / or second secondary air sources can be continuously adjustable, for example, such that the supply of secondary air during full-load vehicle operation is not only performed in a specified sequence or mode, but is also continuously adjustable. In the context of this invention, load can be understood in particular to mean vehicle operation at a speed higher than idle.

[0010] It is further advantageous when the energy for actuating the first controllable secondary air source to supply secondary air is provided by the vehicle's onboard battery, while the energy for actuating the second controllable secondary air source to supply secondary air is preferably provided by a different power source, particularly by an electric motor coupled to the vehicle's internal combustion engine. In this manner, a certain degree of reliability is particularly possible, ensuring reliable performance of the exhaust aftertreatment system even in the vehicle's emergency mode. Specifically, in the context of providing power to control the other source, energy can be provided via an electric motor coupled to the vehicle's internal combustion engine, load transfer, and / or speed increase and recovery.

[0011] Given the rapid, reliable, and efficient exhaust aftertreatment of a vehicle's internal combustion engine, it may be particularly advantageous when the first controllable secondary air source is configured as a secondary air blower and the second controllable secondary air source is configured as at least one electric exhaust turbocharger. Similarly, for example, two electric exhaust turbochargers can be provided as the second controllable secondary air source. Thus, for example in normal mode, exhaust aftertreatment can be performed via a secondary air blower controlled by a control unit by selectively supplying secondary air to the combustion chamber, optimizing exhaust aftertreatment before the exhaust is emitted. Subsequently, alternatively or cumulatively, in emergency mode, after entering the combustion chamber through a throttle valve, the secondary air can be conducted via one or two electric exhaust turbochargers, preferably via another secondary air routing system, through the compressor and intercooler.

[0012] Similarly, given the rapid, reliable, and efficient exhaust aftertreatment of the vehicle's internal combustion engine, it may be advantageous when the first controllable secondary air source is configured as a secondary air blower and the second controllable secondary air source is configured as a first compressor and a second compressor. Likewise, in this case, in normal mode, exhaust aftertreatment can be performed via the secondary air blower by selectively supplying secondary air to the combustion chamber, while being controlled by the control unit (e.g., using a pre-compressor) to optimize exhaust aftertreatment before the exhaust is discharged. Subsequently, alternatively or cumulatively, in emergency mode, secondary air can be routed to the combustion chamber via the second compressor stage and the intercooler after passing through a throttle valve.

[0013] In the context of this invention, it can be further proposed that the supply of secondary air via a first controllable secondary air source and / or a second controllable secondary air source is actuated by means of a control unit, wherein the adjustment of the supply of secondary air is preferably performed at least in part as a function of a measurable parameter, particularly as a function of one or more of the following parameters:

[0014] -The time from the start of the internal combustion engine

[0015] -Current engine load,

[0016] -Current engine speed,

[0017] -Current catalytic converter temperature,

[0018] - Heating process of the catalytic converter

[0019] - The total energy input into the catalytic converter.

[0020] Such regulation of the first and / or second controllable secondary air sources particularly allows for highly precise, targeted, and flexible adjustments to the current combustion air ratio within the exhaust space. Similarly, the regulation of the secondary air supply can preferably occur at least in part as a function of the current exhaust back pressure in the vehicle's exhaust system, as a function of the current pressure of the secondary air, or as a function of the calculated catalytic converter heating process, etc.

[0021] This may be advantageous when, in addition to changing the supply of secondary air for adjusting the current combustion air ratio within the exhaust space, other parameters are modified, preferably one or more of the following:

[0022] -Vehicle engine speed,

[0023] -The combustion air ratio in the combustion chamber,

[0024] - Current fuel injection parameters,

[0025] - Current ignition angle position.

[0026] In this way, it is particularly possible to quickly, accurately, and flexibly adjust the current combustion air ratio in the exhaust space.

[0027] Furthermore, given the effective exhaust aftertreatment, this is advantageous when the supply of secondary air is regulated such that post-catalytic control is activated during secondary air operation, provided that the combustion air ratio in the exhaust space is between 0.95 and 1.05.

[0028] According to another aspect of the invention, a computer program is provided. This computer program includes instructions that, when executed by a computer, cause the computer program to perform the methods described in detail above. Therefore, the computer program according to the invention provides the same advantages as those already described in detail above with respect to the methods according to the invention. The computer program can be implemented as computer-readable instruction code in any suitable programming language (e.g., JAVA or C++). The computer program can be stored on a computer-readable storage medium such as a data disk, a removable drive, volatile or non-volatile memory, or built-in memory / processor. The instruction code can program a computer or other programmable devices (such as controllers) to perform desired functions. Furthermore, the computer program can be provided on a network (e.g., the Internet), from which a user can download the computer program as needed. The computer program can be implemented in software form, or as a computer program product implemented by means of one or more dedicated electronic circuit systems, i.e., in hardware, or in any hybrid form, i.e., by means of software components and hardware components. According to another aspect of the invention, a storage device on which a computer program is stored is provided, wherein the computer program is configured and designed to perform the methods described above. Therefore, the storage device according to the invention also provides the advantages described above. Storage devices can be understood as data carriers on which computer programs are stored, such as thumb drives.

[0029] Furthermore, the controller includes a computer program installed thereon, which is configured and designed to facilitate the execution of the methods described above. The control unit according to the invention also provides the advantages described above. The control unit is preferably a vehicle controller or part of a vehicle control unit.

[0030] The subject of this invention further relates to a system according to the invention for performing exhaust aftertreatment on an internal combustion engine of a vehicle with an exhaust system, particularly for performing the methods described above. Here, the system according to the invention includes a first controllable secondary air source and a second controllable secondary air source having a secondary air routing system. The second controllable secondary air source is used to adjust the current combustion air ratio in the exhaust space to a target value for the combustion air ratio in the exhaust space via a secondary air supply and a control unit for regulating the secondary air supply. The current combustion air ratio can be adjusted in normal mode by means of the first controllable secondary air source via the secondary air supply, and in emergency mode by means of the second controllable secondary air source via the secondary air supply. Fine-tuning of the target value for the combustion air ratio in the exhaust space can preferably be implemented via approved pre-catalytic converter control. Here, the vehicle's exhaust system may include, for example, a gasoline particulate filter, a catalytic converter, and an exhaust turbocharger. The exhaust system may also be connected via a piping system to the vehicle's internal combustion engine, particularly the individual cylinders of the internal combustion engine. The secondary air blower can also be connected to the exhaust system piping system via a secondary air introduction system, through which the supply of secondary air can be regulated for rapid and efficient exhaust aftertreatment to ensure low-emission operation of the vehicle's combustion engine. The exhaust turbocharger can preferably be configured as an electronically controlled exhaust turbocharger and can additionally be connected to the vehicle's combustion chamber via another secondary air introduction system, wherein a compressor, intercooler, and throttle valve can be arranged between the exhaust turbocharger and the combustion chamber. The system according to the invention for performing exhaust aftertreatment on the internal combustion engine of a vehicle is also preferably configured such that the supply of secondary air can be continuously adjusted by a control unit during full-load driving of the vehicle.

[0031] The subject matter of this invention also includes vehicles with systems as described above. Attached Figure Description

[0032] Other advantages, features, and details of the invention will arise from the following description, in which exemplary embodiments of the invention are described in detail with reference to the accompanying drawings. The features mentioned in the claims and specification may be essential to the invention independently or in any combination.

[0033] The following is illustrated schematically:

[0034] Figure 1 : An embodiment of a system for performing exhaust aftertreatment according to a first exemplary embodiment,

[0035] Figure 2 According to an embodiment of the method for performing exhaust gas aftertreatment according to a first exemplary embodiment,

[0036] Figure 3 The present invention relates to an embodiment of a method for performing exhaust aftertreatment in detail according to a first exemplary embodiment. Detailed Implementation

[0037] Figure 1 An embodiment of the system 2 according to the invention for performing exhaust aftertreatment according to a first exemplary embodiment is shown.

[0038] Here, system 2 includes a controllable secondary air blower 10 with a secondary air routing system 14 for adjusting the current combustion air ratio 300 in the exhaust space 20' of the vehicle's (not shown) exhaust system 20 to a target value for the combustion air ratio in the exhaust space 20'. The adjustment 300 of the current combustion air ratio is implemented via a control unit 12 through the supply of secondary air, which regulates the supply of secondary air. The supply of secondary air is implemented in normal mode I by means of a first controllable secondary air source 10, and in emergency mode II by means of second controllable secondary air sources 22, 30, thereby ensuring reliable operation of the exhaust aftertreatment. Here, the exhaust system 20 includes first and second gasoline particulate filters 16, first and second catalytic converters 18, and first and second exhaust turbochargers 22, and is connected via exhaust lines 24 to the combustion chamber 4' of the internal combustion engine 4, particularly to the individual cylinders of the internal combustion engine 4. The first controllable secondary air source 10 is preferably configured as a secondary air blower and connected to the exhaust line 24 of the exhaust system 20 via a secondary air routing system 14. The second controllable secondary air sources 22, 30 are preferably configured as one or two electric turbochargers 22 and / or two compressors 30. In Emergency Mode II, where, for example, the onboard battery does not have sufficient capacity, secondary air supply can then be implemented, for example, by means of an electric exhaust turbocharger, which can supply secondary air to the combustion chamber 4' via the compressors 30, intercooler 38, and throttle valve 36.

[0039] Figure 2 An embodiment of the method for performing exhaust aftertreatment according to the present invention is shown.

[0040] Specifically, Figure 2The following steps according to the invention are schematically illustrated: starting the internal combustion engine 4 according to 100, specifying a target value for the combustion air ratio λ in the exhaust space 20' of the exhaust system 20 according to 200, and adjusting the current combustion air ratio λ in the exhaust space 20' of the exhaust system 20 according to 300 to the target value of the combustion air ratio λ in the exhaust space 20' of the exhaust system 20, wherein the adjustment 300 of the current combustion air ratio λ is carried out in normal mode I by means of a first controllable secondary air source 10 via the supply of secondary air, and in emergency mode II by means of a second controllable secondary air source 22, 30 via the supply of secondary air.

[0041] In doing so, the supply of secondary air via the first controllable secondary air source 10 and / or via the second controllable secondary air source 22, 30 can preferably be actuated by means of the control unit 12, wherein the regulation of the secondary air supply can preferably be at least in part a function of measurable parameters, in particular a function of the time since the start of the 100 internal combustion engine 4 and / or the current engine load and / or the current engine speed and / or the current catalytic converter temperature.

[0042] In addition to supplying secondary air to adjust the current combustion air ratio λ in the 300 exhaust space 20', other parameters can also be changed, such as preferably, the vehicle's engine speed and / or the combustion air ratio λ in the combustion chamber 4' and / or the current fuel injection parameters and / or the current ignition angle position.

[0043] Figure 3 An embodiment of the method for performing exhaust aftertreatment according to the invention in detail according to a first exemplary embodiment is shown.

[0044] Specifically, Figure 3 Views are shown of five operating phases BP1 to BP5 preferably provided within the scope of the invention, and preferably provided during these operating phases for variations in the following parameters: load L, which can vary between infinite u, moderate m, and idle LL; target values ​​for the air-fuel ratio λ in the exhaust space λAR (varying between 1.3 and 1.01) and combustion chamber λVR (varying between 1 and 0.65); variations in the secondary air supply settings (varying between 20% load, 70% load, and 100% load); and ignition angle ZW, which preferably varies between +10°, 0°, and -40° depending on top dead center (OT). In the present case, the first operating phase preferably lasts 0 to 15 seconds, the second operating phase BP2 lasts 0 to 5 seconds, and the third operating phase BP3 lasts 0 to 3 seconds. Furthermore, the fourth operating phase BP4 lasts 0 to 60 seconds, and the fifth operating phase BP5 lasts 0 to 120 seconds.

[0045] By corresponding, predetermined, and purposefully controlled changes in the parameters, it is particularly possible to implement rapid and effective exhaust aftertreatment within the scope of the method according to the invention, even during operation under load, which ensures low-emission operation of the vehicle's internal combustion engine.

[0046] The above explanation of the embodiments describes the invention only in the context of examples. Of course, without departing from the scope of the invention, the various features of the embodiments can be freely combined with each other if it is technically meaningful.

Claims

1. A method for performing exhaust aftertreatment on an internal combustion engine (4) of a vehicle having an exhaust system (20), the method comprising the steps of: -Start (100) the internal combustion engine (4), -Specify the target value of the combustion air ratio (λ) within the exhaust space (20') of the exhaust system (20) described in (200). - Adjust (300) the current combustion air ratio (λ) in the exhaust space (20') of the exhaust system (20) to the target value of the combustion air ratio (λ) in the exhaust space (20'). The feature is that the adjustment (300) of the current combustion air ratio (λ) is implemented in normal mode (I) by means of a first controllable secondary air source (10) via the supply of secondary air, and in emergency mode (II) by means of a second controllable secondary air source (22, 30) via the supply of secondary air. The normal mode (I) is the operation of the exhaust aftertreatment system, in which the energy for exhaust aftertreatment is provided by the vehicle battery; the emergency mode (II) is the operation of the exhaust aftertreatment system, in which the energy for exhaust aftertreatment is no longer provided by the vehicle battery; or, the normal mode (I) is the state of the exhaust space, in which the basic pressure supply is sufficient; the emergency mode (II) is the state of the exhaust space, in which the basic pressure supply is no longer sufficient.

2. The method according to claim 1, characterized in that, During the full-load operation of the vehicle, the supply of secondary air is continuously adjusted.

3. The method according to claim 1 or 2, characterized in that, The energy used to actuate the first controllable secondary air source (10) to supply the secondary air is provided by the vehicle's onboard battery, while the energy used to actuate the second controllable secondary air source (22, 30) to supply the secondary air is provided by different power sources.

4. The method according to claim 3, characterized in that, The energy used to actuate the second controllable secondary air source (22, 30) to supply secondary air is provided by an electric motor combined with the internal combustion engine of the vehicle.

5. The method according to claim 1 or 2, characterized in that, The first controllable secondary air source (10) is configured as a secondary air blower, and the second controllable secondary air source (22, 30) is configured as at least one electric exhaust turbocharger.

6. The method according to claim 1 or 2, characterized in that, The first controllable secondary air source (10) is configured as a secondary air blower, and the second controllable secondary air source (22, 30) is configured as a first compressor and a second compressor.

7. The method according to claim 1 or 2, characterized in that, The supply of secondary air via the first controllable secondary air source and / or the second controllable secondary air source is actuated by means of a control unit (12), wherein the adjustment of the supply of secondary air is performed at least in part as a function of a measurable parameter, which is a function of one or more of the following parameters: -The time from the start of the internal combustion engine (4) mentioned in (100), -Current engine load, -Current engine speed, -Current catalytic converter temperature, - Heating process of catalytic converter (18), - The total energy input into the catalytic converter (18).

8. The method according to claim 1 or 2, characterized in that, In addition to the supply of secondary air used to adjust the current combustion air ratio (λ) within the exhaust space (20') of (300), one or more of the following parameters are also changed: -The engine speed of the vehicle, - The combustion air ratio (λ) in the combustion chamber (4'), - Current fuel injection parameters, - Current ignition angle position.

9. The method according to claim 1 or 2, characterized in that, The supply of the secondary air is adjusted such that post-catalytic control is activated during secondary air operation, provided that the combustion air ratio (λ) in the exhaust space (20') is between 0.95 and 1.

05.

10. A system (2) for performing exhaust aftertreatment on an internal combustion engine (4) of a vehicle having an exhaust system (20), the system being used to perform the method according to any one of claims 1 to 9, the system comprising a first controllable secondary air source (10) and a second controllable secondary air source (22, 30) having a secondary air routing system (14), the second controllable secondary air source being used to adjust (300) the current combustion air ratio (λ) in the exhaust space (20') to a target value of the combustion air ratio (λ) in the exhaust space (20') via a secondary air supply and a control unit (12) for adjusting the secondary air supply, characterized in that, The current combustion air ratio (λ) can be adjusted in normal mode (I) by means of a first controllable secondary air source (10) via the supply of secondary air, and in emergency mode (II) by means of a second controllable secondary air source (22, 30) via the supply of secondary air.

11. A vehicle comprising the system (2) according to claim 10.

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