Internal combustion engine for a motor vehicle

Abstract

The invention relates to an internal combustion engine (10) for a motor vehicle, having an exhaust tract (20) through which exhaust gases can flow from the internal combustion engine (10), a turbine (28) arranged in the exhaust tract (20) and drivable by exhaust gases, and an exhaust gas recirculation device (50) having an exhaust gas recirculation line (52) by means of which at least a portion of the exhaust gases can be tapped off from the exhaust tract (20) at a tapping point (A1) arranged upstream of the turbine (28) and fed back to an air intake tract (18) of the internal combustion engine (10) through which air can flow and can be fed into the air intake tract (18) at a feed-in point (E1), wherein an electrically drivable compressor wheel (32, 92) is arranged in the air intake tract (18) upstream or downstream of the feed-in point (E1) for compressing the air flowing through the air intake tract (18).

Description

Technical Field

[0001] The present invention relates to an internal combustion engine for a motor vehicle according to the preamble of claim 1. Background Technology

[0002] An internal combustion engine of the same type for motor vehicles has been disclosed, for example, by DE 10 2018 006 413 A1. The internal combustion engine has an exhaust manifold through which exhaust gas flows and a turbine impeller / turbine arranged in the exhaust manifold through which exhaust gas flows, which may, for example, be a component of an exhaust turbocharger. Furthermore, an exhaust gas recirculation device is provided, having an exhaust gas recirculation line, whereby at least a portion of the exhaust gas flowing through the exhaust manifold is diverted from the exhaust manifold at a diversion point located upstream of the turbine and returned to the internal combustion engine intake manifold through which air flows, and is introduced into the intake manifold at an inlet and further into the air flowing through the intake manifold.

[0003] Additionally, GB 2590942 A discloses an air intake system for an internal combustion engine. US10677140 B1 discloses an exhaust delivery valve having multiple ports. DE 10 2018 006 413 A1 discloses an internal combustion engine for a motor vehicle. DE 10 2015015 794 A1 discloses a method for heating at least one exhaust aftertreatment device disposed in the exhaust manifold of a motor vehicle including and driven by an internal combustion engine. Furthermore, DE 10 2019 003 576 A1 discloses a method for operating an internal combustion engine for a motor vehicle. Summary of the Invention

[0004] The objective of this invention is to improve the type of internal combustion engine described above in such a way that it can achieve operation with very low emissions.

[0005] This task is accomplished by an internal combustion engine having the features of claim 1. Advantageous designs with suitable inventive improvements are described in the dependent claims.

[0006] To improve internal combustion engines of the type described in the preamble of claim 1, particularly those designed as diesel engines, i.e., to achieve low-emission operation, the present invention specifies the provision of an electrically driven compressor impeller located upstream or downstream of the intake port in the intake manifold for compressing the air flowing through the intake manifold. This means that the compressor impeller is part of an electric compressor, i.e., an electrically operated compressor, which has a compressor impeller and a motor by means of which the compressor impeller can be electrically driven to compress air. Air compression is also referred to as boosting or pressurization. Since the compressor impeller is electrically driven, electric-assisted boosting is achieved. With electric-assisted boosting, the driving scavenging pressure difference, especially between the split-flow and intake ports, can be reduced compared to common solutions, where this scavenging pressure difference is used for exhaust gas recirculation. Exhaust gas recirculation is also referred to as exhaust gas recirculation, and in this invention, exhaust gas recirculation can be particularly advantageously performed. The present invention is particularly based on the understanding and consideration that turbocharging technology has been established to improve the specific power of internal combustion engines and reduce emissions and consumption. In this context, a fluid machine, specifically designed as an exhaust turbocharger or functioning as an exhaust turbocharger, or capable of operating as an exhaust turbocharger, exhibits inertia that leads to delayed boost pressure formation during dynamic operation. During load surges at low engine speeds (e.g., at constant speeds during startup, particularly from idling), the exhaust turbocharger operates at low speeds, or boost pressures. That is, from the initial state, maximum torque cannot be immediately released under maximum torque requirements; instead, the injection quantity or torque is released at most with a minimum air-fuel ratio (λ). Torque formation follows boost pressure, which in turn depends on turbine size, efficiency, inertia, enthalpy supply, and exhaust gas recirculation rate. Once a constant boost pressure is reached, smoky or lean operation ceases. In these engine-dependent applications, a trade-off is sought between dynamic torque formation and exhaust gas recirculation rate, i.e., nitrogen oxide formation, because exhaust gas recirculation reduces fresh air mass flow and thus increases boost pressure requirements and reduces the energy supply to the turbine. The most critical period occurs after cold start and before the NOx purification via SCR (Selective Catalytic Reduction) reaches operating temperature. NOx purification begins to take effect at approximately 160-180 degrees Celsius, increasing to approximately 240-270 degrees Celsius with increasing efficiency. Subsequently, the AGR rate can be reduced or original NOx emissions can be increased to generate a small amount of soot due to the conflict between NOx and soot emissions, thus extending the regeneration interval for particulate filters, such as diesel particulate filters (DPFs), and improving the aging and dynamic power delivery of the exhaust purification system. To mitigate this conflict, techniques with faster boost pressure formation are effective. These techniques can also vary depending on the energy type.

[0007] - Smaller VTG turbines offer higher efficiency over lower flow rates.

[0008] - Turbines with low inertia, such as those made of ceramic materials or TiAl.

[0009] - Mechanical auxiliary compressor,

[0010] - Compressed air or air is blown in front of the turbine.

[0011] - Electric auxiliary compressor,

[0012] - Electric turbocharger.

[0013] Under load surges at constant speed, the following relationship emerges for diesel engine-dependent applications: NOx emissions decrease until maximum torque is reached. In the corresponding evaluation analysis, for example, the time or work done until a certain torque is reached is plotted, i.e., the positive power integral. Similarly, the NOx mass flow is integrated. By varying the AGR rate, different x and y value pairs are obtained, and curves can be formed illustrating the aforementioned relationship / correlation, particularly showing how NOx emissions vary with "time before reaching the stated torque" or with "work done." By adding an electric compressor or electric turbocharger, especially in load transfers at constant speeds, brief electric assistance facilitates significantly faster boost pressure formation, but also results in a substantial increase in NOx flow without application adjustments. Application adjustments lead to improvements related to NOx emissions, boost pressure, and torque formation. It has been found that smaller, more powerful turbines slightly improve the trade-off between NOx emissions and favorable dynamics. Significant improvements can be achieved through the use of electric turbochargers or electric compressors. The form of electric assistance affects the drive scavenging pressure differential from the splitter to the inlet in exhaust gas recirculation (EGR) devices, such as those designed for high-pressure EGR. For example, using an electric compressor impeller in an electric turbocharger or electric auxiliary compressor allows for an increase in the pressure present in the intake manifold, also known as the intake manifold pressure, without also increasing the pressure present in the exhaust manifold ahead of the turbine. Consequently, the drive scavenging pressure differential from the splitter to the inlet decreases in a manner independent of the initial level, thus preventing exhaust gas recirculation. This results in no further improvement in NOx emissions, although boost pressure can be built up more quickly.

[0014] The specification also stipulates that the exhaust gas recirculation device has an exhaust gas recirculation valve, thereby regulating the amount of exhaust gas flowing through the exhaust gas recirculation line. Here, a turbine is arranged in a turbine housing through which exhaust gas flows and is rotatable relative to the turbine housing. The exhaust gas recirculation valve is also arranged in the turbine housing and is movable relative to the turbine housing to regulate the amount of exhaust gas. Alternatively, an exhaust manifold is provided in the exhaust duct, where exhaust gas from multiple combustion chambers of the internal combustion engine is collected. The exhaust gas recirculation valve is arranged in the exhaust manifold and is movable relative to the exhaust manifold to regulate the amount of exhaust gas. Attached Figure Description

[0015] Other advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and in conjunction with the figures. The features and combinations thereof mentioned above in the specification, as well as those mentioned below in the description of the drawings and / or shown individually in the figures, may be used not only in their respective described combinations, but also in other combinations or individually, without departing from the scope of the invention.

[0016] The diagram shows:

[0017] Figure 1 A schematic diagram showing a first embodiment of an internal combustion engine for a motor vehicle;

[0018] Figure 2 A schematic cross-sectional view of a portion of an internal combustion engine is shown;

[0019] Figure 3 A partial cross-sectional schematic diagram of a second embodiment of an internal combustion engine is shown;

[0020] Figure 4 A front view schematic diagram of a portion of a turbine used in an internal combustion engine is shown;

[0021] Figure 5 A partial cross-sectional schematic diagram of a third embodiment of an internal combustion engine is shown;

[0022] Figure 6 A cross-sectional schematic diagram of a fourth embodiment of an internal combustion engine is shown.

[0023] In the figure, identical or functionally identical parts are labeled with the same reference numerals. Detailed Implementation

[0024] Figure 1A first embodiment of an internal combustion engine 10 for a motor vehicle is illustrated schematically. The internal combustion engine 10 is preferably designed as a diesel engine. The internal combustion engine 10 has an engine assembly 12 with a plurality of cylinders 14, wherein each cylinder 14 forms or defines a corresponding combustion chamber 16 of the internal combustion engine 10. The internal combustion engine 10 has an intake duct 18, also referred to as an intake manifold, through which air flowing through the intake duct 18 is directed to and fed into the combustion chamber 16. Furthermore, the internal combustion engine 10 has an exhaust duct 20 through which exhaust gas from the combustion chamber 16 flows, and an exhaust manifold 22, also simply referred to as a manifold, is provided therein. By means of the exhaust manifold 22, exhaust gas from the plurality of combustion chambers 16, particularly all of the combustion chambers, of the internal combustion engine 10 is collected. The internal combustion engine 10 has an exhaust turbocharger 24, which has a turbine 26 with a turbine 28 arranged in the exhaust duct 20. The turbine 28 can be driven by the exhaust gas flowing through the exhaust duct 20. The exhaust turbocharger 24 also includes a compressor 30 disposed in the intake duct 18, which has a compressor impeller 32, thereby compressing the air flowing through the intake duct 18 by driving the compressor impeller 32. Here, the compressor impeller 32 can be driven by a turbine 28 via the shaft 34 of the exhaust turbocharger 24. In the first embodiment, the exhaust turbocharger 24 has a motor 36, by which at least the compressor impeller 32 can be electrically driven. Therefore, the exhaust turbocharger 24 is designed as an electric exhaust turbocharger, that is, an electrically operable exhaust turbocharger. The pressure present upstream of the compressor impeller 32 in the intake duct 18 is indicated by p1. In the intake duct 18, a boost air cooler 39 is disposed downstream of the compressor impeller 32 and upstream of the combustion chamber 16, by means of which the compressed air is cooled. The air pressure present in the intake duct 18 downstream of the boost air cooler 39 and upstream of the combustion chamber 16 is designated p2s, where p2s is also referred to as the boost pressure, for example, air can be compressed to this boost pressure by means of the compressor impeller 32. The pressure present in the exhaust duct 20 downstream of the combustion chamber 16 and upstream of the turbine 28 is designated p3.

[0025] An exhaust aftertreatment device 38 is provided in the exhaust duct 20 through which exhaust gas flows. The exhaust gas is treated by means of the exhaust aftertreatment device 38. The pressure present in the exhaust duct 20 downstream of the turbine 28 and upstream of the exhaust aftertreatment device 38 is indicated by p4. The temperature of the exhaust gas in the exhaust duct 20, also called the exhaust temperature, is indicated by T4, where the exhaust gas has a temperature T4 downstream of the turbine 28 and upstream of the exhaust aftertreatment device 38. The exhaust aftertreatment device 38 has exhaust aftertreatment components 40a-40d, wherein exhaust aftertreatment component 40d is arranged downstream of the turbine 28 and upstream of exhaust aftertreatment component 40c. Exhaust aftertreatment component 40c is arranged downstream of exhaust aftertreatment component 40d and upstream of exhaust aftertreatment component 40b, while exhaust aftertreatment component 40b is arranged upstream of exhaust aftertreatment component 40c and upstream of exhaust aftertreatment component 40a. Exhaust aftertreatment component 40d is, for example, an oxidation catalyst, especially a diesel oxidation catalyst (DOC). Exhaust aftertreatment component 40c includes, for example, a particulate filter, especially a diesel particulate filter (DPF). Alternatively or additionally, the exhaust aftertreatment component 40c may have an SCR catalyst. In particular, the exhaust aftertreatment component 40c may have a coating that catalyzes selective catalytic reduction (SCR) for exhaust gas denitrification, and this coating may be provided on a particulate filter, especially a diesel particulate filter. The exhaust aftertreatment component 40b is, for example, an SCR catalyst, especially a second SCR catalyst. The exhaust aftertreatment component 40a is, for example, an ammonia-blocking catalyst (ASC).

[0026] In the first embodiment, an exhaust valve / baffle 42 is provided in the exhaust duct 20 downstream of the exhaust aftertreatment device 38 and thus downstream of the turbine 28, thereby allowing exhaust gas to be stored within the exhaust duct 18. For example, the exhaust valve 42 is arranged in the pipe member of the exhaust duct 20 and can move, in particular, swing, relative to the pipe member between at least two different positions. Due to the exhaust valve 42, in the first position, at least a partial area of ​​the flow cross section of the exhaust duct 20 through which exhaust gas can flow is locked by means of the exhaust valve 42, so that exhaust gas can no longer flow through that partial area. In the second position, the exhaust valve 42 opens, for example, that partial area.

[0027] Turbine 26, particularly turbine 28, is equipped with a bypass device 44. The bypass device 44 includes a bypass line 46, also referred to as a bypass line or exhaust pressure relief line. The bypass line 46 is in fluid communication with exhaust passage 20 at connection points V1 and V2, with connection point V1 located upstream of turbine 28 and connection point V2 located downstream of turbine 28, particularly upstream of exhaust aftertreatment device 38. Through the bypass line 46, at least a portion of the exhaust gas flowing through exhaust passage 20 can be diverted from exhaust passage 20 and into bypass line 46 at connection point V1. The diverted exhaust gas can flow through bypass line 46 and be delivered to connection point V2, where it can both exit from bypass line 46 and flow back into exhaust passage 20. The exhaust gas flowing through bypass line 46 bypasses turbine 28, therefore turbine 28 is not driven by the exhaust gas flowing through bypass line 46. The bypass device 44 also includes a valve 48, also known as an exhaust vent valve, exhaust pressure relief valve, or bypass valve, which allows regulation of the exhaust flow through the bypass line 46. By regulating the exhaust flow through the bypass line 46, for example, the power of the turbine 26 (also known as turbine power) can be adjusted, and thereby the boost pressure (pressure p2s) can be regulated.

[0028] The internal combustion engine 10 has a first exhaust gas recirculation device 50, thereby enabling exhaust gas recirculation designed as high-pressure exhaust gas recirculation. Therefore, the exhaust gas recirculation device 50 is designed as a high-pressure exhaust gas recirculation device. The exhaust gas recirculation device 50 includes a recirculation line 52, also referred to as an exhaust gas recirculation line. The recirculation line 52 is fluidly connected to the exhaust passage 20 at a branch point A1 and fluidly connected to the intake passage 18 at an inlet point E1, thereby allowing at least a portion of the exhaust gas flowing through the exhaust gas recirculation device 50 to be diverted from the exhaust passage 20 and introduced into the recirculation line 52 at the branch point A1 via the recirculation line 52. The diverted exhaust gas introduced into the recirculation line 52 can flow through the recirculation line 52 and be directed to the inlet point E1 via the recirculation line 52. At the inlet E1, exhaust gas flowing through the recirculation line 52 can exit from the recirculation line 52 and thus flow into the intake duct 18, such that the exhaust gas flowing through the recirculation line 52 is introduced into the intake duct 18 at the inlet E1 and subsequently into the air flowing through the intake duct 18. In the first embodiment, the exhaust gas recirculation device 50 is designed as both a cooled and uncooled exhaust gas recirculation device. This is particularly understood as follows: an exhaust gas recirculation cooler 54 is provided in the recirculation line 52, thereby cooling at least a portion of the exhaust gas flowing through the recirculation line 52. Furthermore, the exhaust gas recirculation device 50 has another bypass line 56, which is fluidly connected to the recirculation line 52 at points S1 and S2. The inlet S1 is arranged upstream of the exhaust gas recirculation cooler 54 in the recirculation line 52, and the inlet S2 is arranged downstream of the exhaust gas recirculation cooler 54 and upstream of the inlet E1 in the recirculation line 52. At least a portion of the exhaust gas flowing through the recirculation line 52 can be diverted from the recirculation line 52 at point S1 and introduced into the other bypass line 56 via another bypass line 56. The exhaust gas introduced into the other bypass line 56 flows through the other bypass line 56 and is transported to point S2 via the other bypass line 56. At point S2, the exhaust gas flowing through the other bypass line 56 can flow out of the other bypass line 56 and flow back into the recirculation line 52. The exhaust gas flowing through the other bypass line 56 bypasses the exhaust gas recirculation cooler 54. This means that the exhaust gas flowing through the other bypass line 56 does not flow through the exhaust gas recirculation cooler 54 and is therefore not cooled by the exhaust gas recirculation cooler 54, but remains uncooled. A valve 58 is provided in the other bypass line 56, by which the amount of exhaust gas flowing through the other bypass line 56 can be adjusted.

[0029] The exhaust gas recirculation device 50 also includes an exhaust gas recirculation valve 60, which can regulate the amount of exhaust gas flowing through the recirculation line 52, that is, the amount of exhaust gas diverted from the exhaust passage 20 at the diversion point A1 via the recirculation line 52. In the intake passage 18, particularly downstream of the boost air cooler 39 and upstream of the combustion chamber 16, especially upstream of the inlet point E1, a throttle valve 62 is provided, which can regulate the amount of air to be supplied to the combustion chamber 16 through the intake passage 18.

[0030] Furthermore, the internal combustion engine 10 has a second exhaust gas recirculation device 64, which is designed as a low-pressure exhaust gas recirculation device. This means that exhaust gas recirculation designed as low-pressure exhaust gas recirculation can be performed by means of the second exhaust gas recirculation device 64. For this purpose, the exhaust gas recirculation device 64 includes a second recirculation line 66, which is also referred to as the second exhaust gas recirculation line. The second recirculation line 66 is fluidly connected to the exhaust passage 20 at the second branch point A2 and fluidly connected to the intake passage 18 at the second inlet point E2. By means of the second recirculation line 66, at least a portion of the exhaust gas flowing through the exhaust passage 20 can be diverted from the exhaust passage and introduced into the second recirculation line 66 at the second branch point A2. The exhaust gas diverted at the branch point A2 and introduced into the second recirculation line 66 can flow through the second recirculation line 66 and be guided to the inlet point E2 by means of the second recirculation line 66. At the inlet E2, exhaust gas flowing through the recirculation line 66 can flow out of the recirculation line 66 and into the intake duct 18, so that the exhaust gas flowing through the recirculation line 66 can enter or be able to enter the intake duct 18 at the inlet E2 and thus enter the air flowing through the intake duct 18. It can also be from... Figure 1 As can be seen, the inlet section E2 is located in the intake duct 18 upstream of the compressor impeller 32. The splitter section A2 is located in the exhaust duct 20 downstream of the turbine 28, specifically downstream of the exhaust aftertreatment device 38 and upstream of the exhaust valve 42. The splitter section A1 is also seen located upstream of the turbine 28 in the exhaust duct 20.

[0031] The second exhaust gas recirculation device 64 may include a second exhaust gas recirculation cooler 68 arranged in the second recirculation line 66. The exhaust gas flowing toward and through the recirculation line 66 can be cooled by means of the exhaust gas recirculation cooler 68. Furthermore, the second exhaust gas recirculation device 64 may include a second exhaust gas recirculation valve 70 arranged in the second recirculation line 66. The exhaust gas flow rate through the recirculation line 66 can be adjusted by means of the exhaust gas recirculation valve 70, that is, the amount of exhaust gas diverted from the exhaust passage 20 and introduced into the recirculation line 66 via the recirculation line 66 at the diversion point A2.

[0032] Because of the use of the exhaust turbocharger 24, which is designed as an electric turbocharger, more power can be fed into the compressor 30 with electrical assistance. The scavenging pressure differential driving the AGR from the split section A1 to the inlet section E1 and further from p3 to p2s is reduced. In the current case, for example, assuming that the AGR rate is insufficient and the turbine 26 is optimally coordinated with the dynamics or AGR requirements, especially with respect to the variable turbine geometry (VTG) and / or exhaust pressure relief valve of the turbine 26. By closing the throttle valve 62, also known as the intake throttle valve, the pressure, also known as the intake manifold pressure and present in the intake duct 18, especially downstream of the boost air coolers 39, 38, such as pressure p2s, can be reduced. The additional boost pressure obtained electrically should be artificially throttled. In addition, the absorption curve in the compressor 30 is closer to the surge limit. Another possibility for increasing the AGR drive scavenging pressure differential is the exhaust valve 42. It allows for a higher scavenging pressure differential without feedback to the compressor 30. As pressure p4 increases, turbine power decreases, at least substantially proportionally to p3 / p4. This is compensated for by the electric turbocharger.

[0033] Figure 1 The internal combustion engine 10 shown, also known as an engine or internal combustion engine, has a low-pressure AGR section in the form of an exhaust gas recirculation device 50 from p3 to p2s, in addition to a high-pressure AGR section from ambient pressure to p1 in the form of an exhaust gas recirculation device 64. This low-pressure AGR section has an exhaust valve 42, thereby allowing, for example, active influence, and especially regulation, of the scavenging pressure difference from ambient pressure to p1. The low-pressure AGR section is therefore an additional low-pressure AGR section, allowing for faster boost pressure formation because the entire AGR mass flow is utilized via the turbine 26. Alternatively, this advantage can be easily achieved by means of an electric turbocharger, without necessarily requiring a low-pressure AGR section or low-pressure exhaust gas recirculation as a measure of nitrogen oxides and kinetics. Furthermore, low-pressure exhaust gas recirculation may not be usable at very low temperatures, especially due to the formation of condensate and icing.

[0034] With the low-pressure AGR stage (exhaust gas recirculation device 64) omitted, exhaust valve 42 can also be used. Therefore, for example, an exhaust gas turbocharger 24 specifically designed as an electric turbocharger may be proposed, which has an exhaust gas recirculation valve or is equipped with an exhaust gas recirculation valve (like, for example, exhaust gas recirculation valve 60), for example in... Figure 2 It is shown in the middle. Figure 2 A portion of the exhaust delivery component through which the exhaust gas flowing through the exhaust passage 20 passes can be seen and is marked with 72. The exhaust delivery component 72 is, for example, a turbine housing in which the turbine 28 is rotatably arranged. Alternatively, the exhaust delivery component 72 may be an exhaust delivery component that is arranged in the exhaust passage 20 upstream of the turbine 28, and particularly upstream of the turbine housing and therefore outside the turbine housing.

[0035] exist Figure 2 The total exhaust flow, indicated by arrow 74, can be seen. The exhaust flows towards and drives the turbine 28. Figure 2 Arrow 76 indicates that the exhaust gas upstream of turbine 28 is diverted from the exhaust passage 20 at the split point A1 via recirculation line 52 and therefore does not drive turbine 28. In this advantageous configuration, the exhaust gas recirculation valve 60 is a valve that, for example, swings to the main exhaust flow into turbine 28. This forces the exhaust gas recirculation, which is particularly desirable. In special cases, it is conceivable that the manifold section is completely enclosed in turbine 26 and the entire exhaust mass flow is forced towards the intake side and thus recirculated. This allows for a 100% AGR rate.

[0036] Figure 3 A portion of a second embodiment of the internal combustion engine 10 is shown. The exhaust delivery / guide 72 can be, for example, an exhaust manifold 22, hence particularly concerning... Figure 2 It is conceivable that the exhaust gas recirculation valve 60 is arranged in the exhaust manifold 22 and can move, in particular rotate, relative to the exhaust manifold 22 to adjust the amount of exhaust gas to be recirculated. In contrast, in Figure 3 In the second embodiment shown, a fixed bifurcation point 80 is provided in the exhaust delivery member 72, especially the exhaust manifold 22, which is therefore not movable relative to the exhaust delivery member 72 (exhaust manifold 22), thereby dividing the total exhaust flow, indicated by arrow 74, into a turbine flow (arrow 76) and an AGR flow (arrow 78).

[0037] Figure 1 The previous schematic diagram shows a turbine 26 with a turbine impeller 28. It can be seen from... Figure 4 As seen in the image, turbine 26 can have a variable turbine geometry (VTG) 82. The variable turbine geometry 82 includes guide vanes 84 that are movable, and in particular rotatable, relative to the turbine housing, thereby allowing, for example, a change in the flow cross-section through which exhaust gas flowing towards turbine 28 can pass, particularly within the turbine housing. Figure 4 The rotation center of one of the guide vanes 84 is indicated by 86. Furthermore, the minimum clearance through which exhaust gas can flow is indicated by 88. The variable turbine geometry 82 is, for example, a tightly sealed variable turbine geometry, in which the radial and axial clearances are minimized, thereby further reducing the flow parameters of the turbine 26. Potential efficiency drawbacks and the resulting lower turbine power are compensated for by an electric turbocharger.

[0038] Figure 5A third embodiment of the internal combustion engine 10 is shown. In this third embodiment, an auxiliary compressor 90 is provided in the intake duct 18, attached to the exhaust turbocharger 24, wherein the auxiliary compressor 90 is an electric auxiliary compressor. Furthermore, in this third embodiment, the exhaust turbocharger 24 is not designed as an electric exhaust turbocharger, therefore no motor is provided for electrically driving the compressor impeller 32. Here, pressure p2s exists downstream of the auxiliary compressor 90, wherein the pressure present in the intake duct 18 downstream of the boost air cooler / intercooler 39 and upstream of the auxiliary compressor 90 is indicated by p2n. The auxiliary compressor 90 has a compressor impeller 92 arranged in the intake duct 18, which is attached to the compressor impeller 32. The compressor impeller 92 is arranged downstream of the compressor impeller 32 and therefore downstream of the boost air cooler 39. Additionally, the auxiliary compressor 90 includes a motor 94, by which the compressor impeller 92 can be driven. By driving the compressor impeller 92, at least a portion of the air flowing through the intake duct 18 can be compressed.

[0039] The compressor impeller 92 is equipped with another bypass mechanism 96 having another bypass line 98. The other bypass line 98 is in fluid communication with the intake duct 18 at locations S3 and S4. Location S3 is located upstream of the compressor impeller 92 and downstream of the compressor impeller 32, particularly downstream of the booster air cooler 39. Location S4 is located downstream of the compressor impeller 92 and upstream of the combustion chamber 16. At least a portion of the air flowing through the intake duct 18 and compressed, particularly by means of the compressor impeller 32, is diverted from the intake duct 18 at location S3 and introduced into the bypass line 98. The air introduced into the bypass line 98 flows through the bypass line 98 and is directed to location S4 via the bypass line 98. At location S4, the air flowing through the bypass line 98 can be discharged from the bypass line 98 and introduced into the intake duct 18. The air flowing through the bypass line 98 bypasses the compressor impeller 92 and is therefore not compressed by the compressor impeller 92.

[0040] exist Figure 5 In the third embodiment shown, a valve 100 is formed in the bypass line 98, and the valve is based on... Figure 5It can be designed as a check valve, which closes towards part S3 and opens in the opposite direction, and therefore towards part S4. Thus, valve 100 allows air flowing through bypass line 98 from part S3 to part S4, but prevents, i.e., avoids, air flowing back from part S4 to part S3 in bypass line 98. Specifically, compressor impeller 92 and / or part S3 are arranged downstream of inlet E1 and therefore downstream of AGR inlet line. This means that high-pressure exhaust recirculation is introduced into intake duct 18 after booster air cooler 39 and before electric auxiliary compressor 90, especially at the location where pressure p2n exists. The boost pressure increased by electric auxiliary compressor 90 does not reduce the drive scavenging pressure differential. Valve 100, designed as a check valve here, prevents air from flowing back from p2s to p2n. Valve 100 is open under normal conditions, but also in case of malfunction, and closes only when pressure p2s is greater than pressure p2n. Valve 100 (check valve) is open when the electric auxiliary compressor 90 is not controlled.

[0041] Alternatively, one could conceive of using an intake throttle valve (throttle valve 62) to replace the function of valve 100, for example, designed as a bypass valve. The electric auxiliary compressor 90 also has the advantage of extending the surge limit through the auxiliary compressor characteristic curve family, which is beneficial at low speeds with high AGR rates. The auxiliary compressor 90, for example, temporarily operates at AGR non-steadily during torque formation and the compressed air is not cooled.

[0042] The aforementioned implementation method achieves a significant improvement in the conflict between nitrogen oxide emissions and dynamics-related objectives. A significant reduction in nitrogen oxide emissions can be achieved at similar driving power. Further advantages are gained by the addition of a supercharger 90, which functions as a high-pressure stage without reducing the volumetric flow of the compressor 30, thus moving it further away from the stability limit (spark limit). It can operate unsteadily, i.e., kinetically at a very high high-pressure AGR rate.

[0043] In one embodiment not shown in the figure, it is conceivable that valve 100 is designed as an active throttling valve, such as throttling valve 62. Thus, for example, valve 100 can be used to actively regulate the air flowing through bypass line 98, and therefore bypassing auxiliary compressor 90. For throttling operation, the electric auxiliary compressor 90 should generate sufficient pressure loss. This can be achieved by stopping operation or rotating it in the opposite direction of flow.

[0044] at last, Figure 6An internal combustion engine 10 according to a fourth embodiment is shown. In the fourth embodiment, an electric auxiliary compressor 90 is arranged in the intake duct 18, but simultaneously downstream of the compressor impeller 32 of the compressor 30 and upstream of the turbocharged air cooler 39. In the fourth embodiment, the exhaust turbocharger 24 is designed as an electric exhaust turbocharger, i.e., an electric-assisted exhaust turbocharger, and therefore includes an electric motor 36.

[0045] List of reference numerals

[0046] 10 Internal Combustion Engine

[0047] 12 Engine Sets

[0048] 14 cylinders

[0049] 16 Combustion Chamber

[0050] 18. Air intake

[0051] 20 Exhaust passage

[0052] 22 Exhaust manifold

[0053] 24 Exhaust Turbocharger

[0054] 26 Turbines

[0055] 28 Turbo

[0056] 30 Compressor

[0057] 32 Compressor impeller

[0058] 34 axes

[0059] 36 motors

[0060] 38 Exhaust aftertreatment device

[0061] 39. Boost Air Cooler

[0062] 40a-40d Exhaust Aftertreatment Components

[0063] 42 Exhaust valve

[0064] 44 Bypass device

[0065] 46 Bypass pipeline

[0066] 48 valves

[0067] 50 Exhaust gas recirculation device

[0068] 52 Recirculation Line

[0069] 54 Exhaust gas recirculation cooler

[0070] 56 Bypass pipeline

[0071] 58 valve components

[0072] 60 Exhaust Recirculation Valve

[0073] 62 Throttling valve

[0074] 64 Exhaust gas recirculation device

[0075] 66 Recirculation Line

[0076] 68 Exhaust gas recirculation cooler

[0077] 70 Exhaust Recirculation Valve

[0078] 72 Exhaust Conveyor

[0079] 74 arrows

[0080] 76 arrows

[0081] 78 arrows

[0082] 80 bifurcation points

[0083] 82 Variable turbine geometry

[0084] 84 Guide vanes

[0085] 86 Center of Rotation

[0086] 88 Minimum gap

[0087] 90 Electric auxiliary compressor

[0088] 92 Compressor impeller

[0089] 94 motor

[0090] 96 Bypass mechanism

[0091] 98 Bypass pipeline

[0092] 100 valves

[0093] A1 Diversion Section

[0094] A2 Diversion Section

[0095] E1 Inlet

[0096] E2 Inlet

[0097] p1 pressure

[0098] p2 pressure

[0099] p2n pressure

[0100] p2s pressure

[0101] p3 pressure

[0102] p4 pressure

[0103] s1 part

[0104] s2 part

[0105] S3 area

[0106] S4 location

[0107] T4 temperature

Claims

1. An internal combustion engine (10) for a motor vehicle, said internal combustion engine having: Exhaust passage (20) through which the exhaust of the internal combustion engine (10) flows. A turbine (28) arranged in the exhaust passage (20) and capable of being driven by exhaust, and An exhaust gas recirculation device (50) has an exhaust gas recirculation line (52) through which at least a portion of the exhaust gas can be diverted from the exhaust passage (20) at a diversion point (A1) located upstream of the turbine (28) and returned to the intake passage (18) of the internal combustion engine (10) through which air can flow, and can be introduced into the intake passage (18) at an inlet point (E1), wherein, An electrically driven first compressor impeller (32) is arranged upstream of the inlet (E1) in the intake duct (18) for compressing the air flowing through the intake duct (18), and wherein the exhaust gas recirculation device (50) has an exhaust gas recirculation valve (60) through which the exhaust gas flow through the exhaust gas recirculation line (52) can be adjusted. Its features are, The turbine (28) is arranged within a turbine housing through which exhaust gas flows and is rotatable relative to the turbine housing, wherein the exhaust gas recirculation valve (60) is also arranged within the turbine housing and is movable relative to the turbine housing to adjust the exhaust gas flow rate; or An exhaust manifold (22) is arranged in the exhaust duct (20) so that exhaust gas from the multiple combustion chambers (16) of the internal combustion engine (10) can be collected in the exhaust manifold. The exhaust gas recirculation valve (60) is arranged in the exhaust manifold (22) and can move relative to the exhaust manifold (22) to adjust the exhaust volume. An auxiliary compressor (90) is arranged on the intake side, and the inlet (E1) of the exhaust recirculation line (52) is located upstream of the auxiliary compressor (90). The auxiliary compressor (90) has a second compressor impeller (92) arranged in the intake duct (18), the second compressor impeller (92) is associated with a bypass mechanism (96) having a bypass line (98) which is fluidly connected to the intake duct (18) at a first part (S3) and a second part (S4). The first part (S3) is arranged upstream of the second compressor impeller (92) and downstream of the inlet part (E1), and the second part (S4) is arranged downstream of the second compressor impeller (92) and upstream of the plurality of combustion chambers (16).

2. The internal combustion engine (10) according to claim 1, characterized in that, Downstream of the turbine (28), an exhaust valve (42) is arranged in the exhaust passage (20) to block exhaust.

3. The internal combustion engine (10) according to claim 1 or 2, characterized in that, The turbine (28) is the turbine (28) of the turbine (26) having a variable turbine geometry (82).

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