Exhaust gas recirculation system

Abstract

Exhaust gas recirculation (EGR) system (122) in a vehicle (100) comprising: a turbine (116) fluidically connected downstream of an exhaust manifold (200); and an EGR channel (124) comprising: a first port (126) connected to a line directly downstream of the turbine (116), wherein an axis of the first port (126) is arranged at a non-perpendicular angle to an axis of rotation of the turbine (116); and a second port connected to an intake system (106), characterized by the fact that the first connection (126) is positioned vertically above a wastegate outlet and the wastegate (120) is positioned inside the pipeline.

Description

BACKGROUND / SUMMARY

[0001] Exhaust gas recirculation (EGR) can be used in internal combustion engines to reduce emissions and improve combustion efficiency and fuel economy. Some EGR systems can draw exhaust gas from a point downstream of a turbine and recirculate it into the intake system. These types of EGR systems can be referred to as low-pressure EGR systems.

[0002] US Patent 7,801,669 discloses an engine with a low-pressure EGR loop. Specifically, the EGR channel is fluidically connected to an exhaust channel downstream of a turbine and a particulate filter. During selected operating conditions, exhaust gas can be redirected through the EGR loop. By positioning the connection point of the EGR channel and the exhaust system downstream of the particulate filter, fouling of the EGR channel can be reduced.

[0003] A turbocharger for an internal combustion engine according to the generic patent DE 10 2010 045 202 A1 comprises a turbine with a turbine wheel attached to a turbine shaft, wherein the turbine wheel and the turbine shaft are rotatably arranged in a turbine housing, the turbine housing comprising a turbine diffuser channel, the turbine diffuser channel having a turbine diffuser inlet and an EGR channel inlet, the EGR channel inlet being radially spaced from the turbine diffuser inlet along the turbine diffuser channel and opening into an EGR channel that is connected to the turbine diffuser channel. The turbine diffuser inlet is configured for fluid connection of an exhaust gas received from an engine to the turbine wheel, the EGR channel being configured for fluid connection of the exhaust gas to an engine intake manifold.The turbocharger also includes a compressor with a compressor wheel attached to the turbine shaft, the compressor wheel and the turbine shaft being rotatably arranged in the compressor housing.

[0004] WO 2011 / 053 513 A2 refers to a turbine housing of an exhaust gas turbocharger, with an inlet connection to which a spiral is attached, and with an outlet connection, characterized by an insulating device for reducing the heat input into the inlet connection, the spiral and / or the outlet connection.

[0005] The inventors identified several disadvantages of the EGR system disclosed in US Patent 7,801,669. The turbine and particulate filter can increase losses within the exhaust gas flowing through the exhaust system, thereby reducing the throughput of exhaust gases passing through the EGR channel. Furthermore, losses within the EGR channel can be significant due to the geometric configuration (e.g., T-branching) of the junction between the EGR channel and the turbine exhaust pipe. Specifically, the tangential component of the gas flow can cause a large amount of flow separation and turbulence at the inlet to the EGR channel. As a result, the efficiency of the EGR system can be reduced.

[0006] In principle, a solution proposed according to claim 1 provides an exhaust gas recirculation (EGR) system in a vehicle. The EGR system comprises a turbine fluidically connected downstream of an exhaust manifold and an EGR channel. The channel has a first port connected directly downstream of the turbine to an exhaust pipe, with one axis of the first port arranged at a non-perpendicular angle to the turbine's axis of rotation, and a second port connected to an intake system. In this way, the EGR channel inlet can be integrated into the turbine housing, thereby reducing losses and increasing the EGR efficiency, and consequently the engine efficiency, during selected operating conditions.

[0007] It was found that positioning the EGR port in this way reduces losses within the EGR system. Specifically, the structural design (e.g., the orientation of the EGR channel) of the tangential component of the exhaust gas flow exiting the turbine allows the flow to be driven through the EGR system, thereby increasing the volume flow of exhaust gas through the EGR channel.

[0008] This summary is provided to introduce, in a simplified form, a selection of concepts that are further described in the detailed description below. This summary is not intended to identify any principal or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to embodiments that eliminate any or all of the disadvantages listed in any part of the disclosure. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 shows a schematic representation of a vehicle with an internal combustion engine, an intake system, an exhaust system and an exhaust gas recirculation system (EGR system). The Fig. 2 - Fig. Figure 6 illustrates different views of an example exhaust system and an EGR system. Fig. 2 - Fig. 6 are approximately to scale. Fig. Figure 7 shows a procedure for operating an EGR system in a vehicle. DETAILED DESCRIPTION

[0009] An exhaust gas recirculation (EGR) system with increased efficiency is disclosed. The EGR system includes an EGR channel with a first port located downstream of a turbine in a vehicle's exhaust system. The first port may be positioned at a non-perpendicular angle to the turbine's axis of rotation. In one example, the turbine's axis of rotation is defined by the axis of rotation of the rotor assembly. In some embodiments, a central axis of the first port may be positioned at an angle between 0 and 90 degrees (e.g., 30 to 60 degrees) to the turbine's axis of rotation. The angle may be selected to balance the axial and peripheral vector components of the flow field exiting the turbine, thereby maximizing the benefits of the EGR process. Furthermore, in some examples, the first port may be integrated into the turbine's exhaust housing, thus enabling reduced losses in the EGR system.In this way, exhaust gas can be effectively directed through an EGR channel during EGR operation. As a result, the efficiency of the EGR system can be increased.

[0010] Fig. Figure 1 shows a schematic representation of a vehicle 100. It is understood that the one in Fig. The components contained in the vehicle shown in Figure 1 are schematically represented. Illustrations of the components, such as the EGR system, are included in the... Fig. 2 - Fig. 6 are shown and discussed in more detail here.

[0011] The vehicle 100 can contain an engine 102 with at least one combustion chamber 104. The engine 102 can be configured to carry out combustion in the combustion chamber 104. During operation, each combustion chamber in the engine 102 typically experiences a four-stroke cycle: the cycle includes the intake stroke, the compression stroke, the power stroke, and the exhaust stroke. During the intake stroke, air is drawn into the combustion chamber. During the compression stroke, a piston (not shown) moves within the combustion chamber 104 to compress the air-fuel mixture. Fuel is introduced into the combustion chamber in a process referred to below as injection. In other examples, however, fuel can be introduced into the combustion chamber 104 during the intake stroke in a process referred to here as port injection.In a process subsequently referred to as ignition, the injected fuel is ignited, for example by means of a spark plug or compression ignition. During the power stroke, the expanding gases push the piston. A crankshaft (not shown) converts the piston movement into torque of the rotating shaft. Finally, during the exhaust stroke, the combusted air-fuel mixture can be directed to an exhaust manifold (not shown). It should be noted that the above is shown only as an example, and that other combustion processes can be carried out in other embodiments. The vehicle 100 includes an intake system 106 and an exhaust system 108, which are connected to the engine 102. The intake system 106 can supply intake gases to the engine, and the exhaust system 108 can receive combustion exhaust gases from the engine 102.Arrow 140 represents the flow of intake air into the engine 102 from the intake system 106, and arrow 142 represents the flow of exhaust gas from the engine 102 to the exhaust system 108. The intake system may contain various components such as an electronic throttle 110. The throttle is configured to change the amount of intake air supplied to the engine 102.

[0012] The exhaust system 108 can contain various components, such as an emission control device 112. It is understood that the emission control device 112 can be positioned downstream of the turbine 116, which is discussed in more detail below. The emission control device can be a catalytic converter with one or more bricks, a particulate filter, etc. Furthermore, in some examples, two or more emission control devices can be used.

[0013] The intake system 106 can include a compressor 114. Likewise, the exhaust system can include a turbine 116. The turbine and compressor (114 and 116) can be contained within a turbocharger. The turbocharger can be configured to selectively supply boost pressure to the engine. In this way, the engine's efficiency can be increased. It is understood that a drive shaft or other suitable mechanical components can be provided in the turbocharger to enable the transmission of rotational energy from the turbine 116 to the compressor 114. The turbine 116 can include a bypass channel 118 in which a wastegate 120 is positioned. Furthermore, in some embodiments, the compressor 114 can include a bypass channel (not shown) and a wastegate (not shown) positioned within it.

[0014] The vehicle may also include an EGR system 122 configured to route exhaust gas from the exhaust system 108 to the intake system 106. Arrows 144 represent the flow of exhaust gas from the exhaust system 108 to the EGR system 122. Similarly, arrow 146 represents the flow of exhaust gas from the EGR system 122 to the intake system 106. The EGR system may include an EGR channel 124, which is described in more detail in the Fig. 2 - Fig. Figure 6 shows that the EGR channel 124 can include a first port 126, which is positioned in the exhaust system 108 downstream of the turbine 116, and a second port 128, which is positioned in the intake system 106. The first port 126 defines the connection between the exhaust system 108 and the EGR system 122. Similarly, the second port 128 defines the connection between the intake system and the EGR system. The first port 126 can be positioned in the exhaust system 108 downstream of the turbine 116. In some embodiments, the second port 128 can be positioned in the intake system 106 upstream of the compressor 114. In other embodiments, however, the second port 128 can be positioned downstream of the compressor 114. The EGR system may further include an EGR cooler 130 and / or an EGR valve 132, both of which may be positioned in the EGR channel 124.The EGR cooler 130 can be configured to remove heat from the exhaust gas flowing through the EGR system 122, and the EGR valve 132 can be configured to regulate the amount of exhaust gas flowing through the EGR system 122. Both the EGR cooler 130 and the EGR valve 132 can be set by commands from the control unit 150, which is discussed in more detail below. In other embodiments, the EGR system 122 may not include the EGR cooler 130.

[0015] The EGR channel 124, and specifically the first connection 126, can have various structural features that reduce losses in the EGR system 122, and which, with reference to the Fig. 2 - Fig. 6 will be described in more detail. The structural features can include the angle at which the first port 126 and / or the EGR channel 124 are arranged relative to the axis of rotation of the turbine 116. The structural features can also include the curvature of the EGR channel 124. Additional features for reducing losses include flush mounting of the first EGR port 126 with the exhaust system and integrating the first port 126 into an exhaust housing of the turbine 116. In one example, the port 126 can be located directly behind the turbine rotor 400 and upstream of the wastegate 120. Space constraints may preclude this design feature, resulting in the port 126 being located downstream of the wastegate 120. At both locations, the angle of the port 126 can be selected to balance the axial and peripheral vector components of the flow field exiting the turbine in order to maximize the benefits of the EGR.

[0016] A temperature sensor 134 can be connected to the motor 102. The temperature sensor can send signals to a control unit 150. The control unit 150 is in Fig. Figure 1 shows a typical microcomputer containing: a microprocessor unit 152, inputs / outputs 154, a read / write memory 156, a read / write memory 158, a battery-powered memory chip 160, and a typical data bus.

[0017] The control unit 150 can be used to operate various components in the vehicle 100, as well as to receive signals from sensors in the vehicle. These components can include the motor 102, the compressor 114, the turbine 116, the EGR cooler 130, and the EGR valve 132. In other examples, however, additional or alternative control units can be used to control the operation of one or more of the aforementioned components.

[0018] Several control strategies can be implemented to operate the aforementioned components. For example, the EGR valve 132 can be controlled by the control unit 150 and configured to modify the gas flow through the EGR channel 124. Thus, during a first operating state, at least a portion of the exhaust gas in the exhaust system 108 can be directed through the EGR system 122 by commands from the control unit 150. In this way, the EGR can be operated to reduce emissions and increase combustion efficiency and fuel economy. Similarly, during a second operating state, exhaust gas can be essentially prevented from flowing through the EGR channel 124 by a command from the control unit 150. In this way, exhaust gas can be selectively routed through the EGR system 122 based on the engine's operating conditions.It is understood that various operating conditions can change the vehicle's need for EGR operation, such as engine temperature, requested torque, intake manifold pressure, injection timing, valve timing, etc. Furthermore, it is understood that during certain operating conditions, such as when the exhaust gas has exceeded a threshold temperature, the EGR cooler 130 can be operated to remove heat from the exhaust gas passing through the EGR channel 124. In this way, excessive temperature conditions in the intake system 106 cannot occur.

[0019] The Fig. 2 - Fig. Figure 6 shows various illustrations of the merging of an EGR channel and an exhaust channel, positioned directly behind a turbine. In other words, no components (e.g., filters, catalysts, coolers, etc.) are positioned between the exhaust channel and the turbine outlet. Specifically, Figure 6 shows... Fig. Figure 2 shows a perspective view of part of the exhaust system 108 and the EGR system 122. As shown, the exhaust system 108 includes an exhaust manifold 200 with branch channels 202 that are fluidically connected to at least one combustion chamber in the engine 102. The branch channels 202 can converge at an exhaust collector 204. It is understood that a variety of exhaust system configurations can be used, and that the configuration shown is exemplary.

[0020] The exhaust gas collector 204 can in turn be connected to an inlet 206 of the turbine 116. As shown, the exhaust system further includes an emission control device 112, which is positioned downstream of the turbine 116. Additionally, the EGR channel 124 is fluidically connected to the exhaust system 108 at a point downstream of the turbine 116. Specifically, in the illustrated embodiment, the merging of the EGR channel 124 and the exhaust system 108 is arranged in an outlet housing 208 of the turbine 116.

[0021] Fig. Figure 3 shows a top view of the merging of the first connection 126 into the EGR channel 124. Although the merging between the first connection 126 and the exhaust system 108 is located in the outlet housing 208 of the turbine 116 in the illustrated embodiment, it is understood that in other embodiments the merging may be located at another suitable location behind the turbine, such as in an exhaust duct.

[0022] It is understood that exhaust gas from the exhaust manifold can be directed into a turbine spiral housing 300. The spiral housing can be configured to direct exhaust gas in such a way that it drives a rotor assembly 400, which is located in Fig. Figure 4 shows that the rotor assembly 400 can be connected in rotation to a drive shaft (not shown) that connects the turbine 116 to the compressor 114. In this way, boost pressure can be supplied to the engine. After passing through the rotor assembly, the exhaust gas can be directed to a turbine outlet defined by the outlet housing 208. The outlet housing 208 is fluidically connected to an exhaust channel 304. As shown, the exhaust channel 304 extends outwards and is curved with respect to the turbine axis of rotation 303. However, other geometric configurations and orientations are possible in other examples.

[0023] As shown, the angle 302 defined between the axis of rotation 303 of the turbine 116 and the central axis 305 of the first port 126 is neither perpendicular nor a right angle. When the first port 126 and the exhaust duct 124 are arranged in this way, a greater proportion of the tangential component of the exhaust gas flow exiting the rotor assembly 400 can be received via the EGR system during EGR operation. Specifically, the angle 302 can be between 0 and 90 degrees in the horizontal longitudinal plane. In the illustrated embodiment, the angle is approximately 50 degrees. However, other angles can be used in other embodiments. The angle 302 has a horizontal longitudinal component and also a vertical longitudinal component. The vertical coordinate axis is oriented in and out of the side in Fig. 3. Additionally, the horizontal coordinate axis 306 is oriented transversely across the side, and the longitudinal coordinate axis 308 is oriented downwards on the side. It is understood that the longitudinal coordinate axis 308 is parallel to the axis of rotation 303 of the turbine 116. The vertical longitudinal component of the angle 302 can be 0-90° (e.g., 30-60°), and the horizontal longitudinal component of the angle 302 can also be 0-90° (e.g., 30-60°). The angles can be physically positioned to balance the axial and peripheral vector components of the flow field exiting the turbine in order to maximize the benefits of the EGR process.

[0024] The exhaust channel 304 is fluidically connected to the turbine outlet housing 208. The exhaust channel is positioned downstream of the turbine outlet housing 208 and the first port 126. As shown, the exhaust channel 304 is curved with respect to the axis of rotation 303 of the turbine. Specifically, in the illustrated embodiment, the exhaust channel 304 is curved and extends away from the first port 126. This particular geometric configuration reduces losses in the EGR system 122 during EGR operation. However, alternative geometric configurations are possible in other embodiments to minimize losses and reduce the effects of downstream back pressure. Additionally, in some embodiments, the exhaust channel 304 can be positioned vertically below the EGR channel 124.

[0025] Three-dimensional flow analysis revealed that positioning the EGR channel 124 and the first connection 126 in this manner (e.g., angle 302 between 40 and 60 degrees) reduces losses caused by the tangential component of the airflow. Specifically, flow separation at the inlet of the EGR channel 124 can be reduced, thereby increasing the efficiency of the EGR system and, consequently, the engine. It is understood that the exhaust gases exiting the turbine 116 can have a higher tangential component than exhaust gases flowing through straight or curved channel sections, due to the flow pattern generated by the turbine's rotor arrangement. The geometric features of the EGR channel 124 allow a larger portion of the tangential component of the EGR gas to be transferred into the EGR channel, thus increasing the efficiency of the EGR system. Line 350 defines the in Fig. The cross-section shown in section 5. Additionally, line 352 defines the area shown in Fig. 6 cross-section shown.

[0026] Fig. Figure 4 shows a cross-sectional view of the turbine 116 and the EGR channel 124. Fig. Figure 4 shows a rotor assembly 400 contained within the turbine 116. The rotor assembly 400 can rotate clockwise or counterclockwise. As shown, the wastegate 120 can be positioned in the exhaust housing 208. The wastegate can be configured to vary the amount of exhaust gas flowing through the turbine bypass channel 118. In this way, the amount of boost pressure supplied to the engine 102 can be adjusted. In other embodiments, however, the wastegate 120 may not be contained within the exhaust system 108. As shown, the first port 126 can be positioned vertically above the wastegate 120 and / or the axis of rotation of the rotor assembly 400. The vertical, horizontal, and longitudinal coordinate axes are given for reference. The longitudinal axis can be aligned with the axis of rotation of the turbine 116. However, it is understood that the Fig. The part of the exhaust system 108 shown in Figure 4 may be positioned in different orientations in other embodiments. Additionally, the diameter of the EGR channel 124 is smaller than the diameter of the exhaust channel 304, which is shown in Figure 4. Fig. 2 and Fig. Figure 3 is shown. In addition, in the illustrated embodiment, the turbine outlet housing 208 has a larger diameter than the exhaust duct 304, which is located in the Fig. 2 and Fig. Figure 3 is shown. However, it is understood that other geometric configurations are possible in other embodiments.

[0027] Fig. Figure 5 shows another view of the turbine 116. As discussed previously, exhaust gas can be directed through the turbine inlet 206 to the spiral casing 300. Additionally, during certain operating conditions, the exhaust gas can be directed through the EGR channel 126.

[0028] Fig. Figure 6 shows a cross-sectional view of the turbine 116, the EGR channel 124, and the first port 126. As shown, the first port 126 can be flush-mounted. Flush mounting, as described here, involves a type of connection between the two channels where there is no protrusion at the joint. In other words, the EGR channel 124 does not extend into the turbine outlet housing 208. This reduces flow separation in the EGR channel. Reduced flow separation can decrease losses in the EGR system, thereby increasing the system's efficiency. Additionally, in some embodiments, the edges of the first port can be rounded to further reduce losses in the EGR channel.

[0029] Additionally, the first port 126 includes a chamfered section 600. As shown, the chamfered section is angled towards the rotor assembly 400. The chamfer can reduce flow separation in the EGR channel 124. In other embodiments, however, the first port 126 may not include a chamfered section. For example, a cross-section of the EGR channel 124 perpendicular to the axis of the channel may be substantially symmetrical (e.g., circular).

[0030] Fig. Figure 6 further shows the chamfered section 600 positioned adjacent to the outer edge 602 of the rotor assembly 400. The positioning and geometric configuration of the chamfered section 600 allows a large amount of the tangential flow of the exhaust gas exiting the turbine 116 to enter the EGR channel 124, thereby reducing losses in the EGR system 122. Furthermore, the first port 126 is positioned close to the rotor assembly 400. Specifically, the first port is positioned downstream of the rotor assembly 400 and is located in the turbocharger housing 208. Additionally, the first port 126 can be positioned downstream of the turbocharger housing 208 in the exhaust channel 304 with respect to the axis of rotation of the rotor assembly.

[0031] Fig. Figure 7 shows a method 700 for the operation of an EGR system in an internal combustion engine of a vehicle. Fig.7 can be carried out by the systems, components, devices, etc. described above, or alternatively can be carried out via other suitable systems, components, devices, etc.

[0032] Steps 702-707 are performed during a first operating condition. In 702, the procedure involves routing at least a portion of the exhaust gas from a turbocharger turbine into an EGR channel. As previously discussed, the EGR channel may be located at a non-perpendicular angle to the turbine's axis of rotation. In 704, the procedure further involves routing exhaust gas through the EGR channel into an intake system. Subsequently, in 706, the procedure involves routing exhaust gas from the intake system to the engine. Step 708 is performed during a second operating condition. In 708, the procedure involves routing most of the exhaust gas from the turbine to the atmosphere. The position of the EGR channel, as well as other structural features of the EGR system disclosed above, enable the reduction of losses within the EGR system, thus allowing for increased EGR efficiency. As a result, engine operation can be improved.

[0033] Preferably, an exhaust gas recirculation (EGR) system according to the invention in a vehicle comprises the following: a turbine fluidically connected downstream of an exhaust manifold; and an EGR channel comprising: a first port connected to a line directly downstream of the turbine, wherein an axis of the first port is arranged at a non-perpendicular angle to the axis of rotation of the turbine; and a second port connected to an intake system. The EGR system further preferably comprises an exhaust gas channel connected to the turbine housing and an EGR channel extending from the first port, wherein the exhaust gas channel is curved.

[0034] Furthermore, preferably the exhaust gas channel is positioned vertically below the EGR channel, and it is advantageous if the diameter of the EGR channel is smaller than the diameter of the exhaust gas channel.

[0035] It is also advantageous if the diameter of the turbine outlet housing is larger than the diameter of the exhaust duct.

[0036] According to another aspect, the exhaust gas recirculation (EGR) system according to the invention in a vehicle comprises the following: a turbine fluidically connected downstream of an exhaust manifold; and an exhaust gas recirculation (EGR) channel comprising a first port connected to an exhaust pipe directly downstream of the turbine, wherein an axis of the first port is arranged at a non-perpendicular angle to the axis of rotation of the turbine, and a second port connected to an intake system, wherein the first port is mounted flush with the exhaust pipe. The angle is preferably between 0 and 90 degrees. The first port more preferably includes an upper section that is chamfered. Advantageously, the first port is positioned vertically above a wastegate outlet.

[0037] The second connection is preferably connected before a compressor.

[0038] According to another aspect, an exhaust gas recirculation (EGR) system according to the invention in a vehicle comprises the following: a turbine fluidically connected downstream of an exhaust manifold; and an exhaust gas recirculation (EGR) channel comprising: a first connection flush with an exhaust pipe directly downstream of the turbine, wherein an axis of the first connection is arranged at an angle of 40-60 degrees to the axis of rotation of the turbine; and a second connection connected to an intake system. Preferably, the first connection is positioned adjacent to a rotor assembly in the turbine, wherein the rotor assembly is at least partially enclosed by an outlet housing of the turbine.

[0039] It is understood that the configurations and / or proposed solutions described herein are exemplary and that these specific embodiments or examples are not to be understood as limiting, since many variations are possible. The subject matter of this disclosure includes all new and non-obvious combinations and sub-combinations of the various features, functions, actions, and / or properties disclosed herein, as well as all equivalents thereto.

Claims

[1] Exhaust gas recirculation (EGR) system (122) in a vehicle (100) comprising: a turbine (116) fluidically connected downstream of an exhaust manifold (200); and an EGR channel (124) comprising: a first port (126) connected to a duct directly downstream of the turbine (116), wherein an axis of the first port (126) is arranged at a non-perpendicular angle to an axis of rotation of the turbine (116); and a second port connected to an intake system (106), characterized by , that the first connection (126) is positioned vertically above a wastegate outlet and the wastegate (120) is positioned inside the line. [2] EGR system (122) according to claim 1, wherein the line is an outlet housing (208) of the turbine (116). [3] EGR system (122) according to claim 1, wherein the axis of the first connection (126) is arranged at an angle greater than zero but less than 90 degrees to the axis of rotation of the turbine (116). [4] EGR system (122) according to claim 1, wherein the first connection (126) is mounted flush with the line. [5] EGR system (122) according to claim 1, further comprising an emission control device (112) connected to the line. [6] EGR system (122) according to claim 1, wherein the second connection (126) is connected upstream of a compressor (114). [7] EGR system (122) according to claim 1, which further comprises an exhaust gas channel (304) connected to the line and an EGR channel (124) extending from the first connection (126), wherein the exhaust gas channel (304) is curved. [8] EGR system (122) according to claim 7, wherein the curvature of the exhaust gas channel (304) extends away from the EGR channel (124). [9] EGR system (122) according to claim 7, wherein the exhaust gas channel (304) is positioned vertically below the EGR channel (124). [10] EGR system (122) according to claim 7, wherein the diameter of the EGR channel (124) is smaller than the diameter of the exhaust gas channel (304).

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