Rechargeable internal combustion engine with compressor and exhaust gas recirculation

Abstract

Supercharged internal combustion engine with - an intake system (1) for supplying charge air, - an exhaust gas removal system for removing exhaust gas, - at least one compressor (2) arranged in an intake line (1a) of the intake system (1), which is equipped with at least one impeller mounted in a housing on a rotatable shaft, and - an exhaust gas recirculation (3) comprising a recirculation line (3a) branching off from the exhaust gas discharge system and opening upstream of the at least one impeller into the intake system (1) forming a node (3b), wherein the node (3b) is formed and arranged in the vicinity of the at least one impeller forming a distance Δ, in which - the intake pipe (1a) upstream of the compressor (2) has a bend (4) by an angle γ and forms a convex outer surface (4a) and a concave inner surface (4b), wherein the node (3b) is located on the side of the intake pipe (1a) on which the concave inner surface (4b) is formed, characterized in that a guide element (5) is located in the intake pipe (1a) which separates the charge air and the recirculated exhaust gas at least section by section at the node (3b), wherein - the guiding element (5) is arc-shaped, and - the arc-shaped guide element (5) and the bend (4) are oriented in the same way.

Description

[0001] The invention relates to a turbocharged internal combustion engine with - an intake system for supplying charge air, - an exhaust gas removal system for removing exhaust gas, - at least one compressor arranged in an intake line of the intake system, which is equipped with at least one impeller mounted in a housing on a rotatable shaft, and - an exhaust gas recirculation system comprising a recirculation line branching off from the exhaust gas discharge system and leading upstream of the at least one impeller into the intake system by forming a node, wherein the node is formed and arranged in the vicinity of the at least one impeller by forming a distance Δ, at the - the intake pipe upstream of the compressor has a bend by an angle γ, forming a convex outer side and a concave inner side, with the node being located on the side of the intake pipe where the concave inner side is formed.

[0002] An internal combustion engine of the type mentioned is used as a motor vehicle drive and is described in US 2019 / 0 234 353 A1 and DE 10 2016 207 948 A1. Within the scope of the present invention, the term internal combustion engine includes gasoline engines, diesel engines, but also hybrid internal combustion engines that utilize a hybrid combustion process, as well as hybrid drives that, in addition to the internal combustion engine, comprise at least one further torque source for driving a motor vehicle, for example, an electric machine that can be connected to or is connected to the drive of the internal combustion engine and which delivers power instead of or in addition to the internal combustion engine.

[0003] In recent years, there has been a trend towards turbocharged engines, with the economic importance of these engines for the automotive industry continuing to increase.

[0004] Turbocharging is primarily a method for increasing performance, in which the air required for the engine's combustion process is compressed, allowing a larger mass of air to be supplied to each cylinder per combustion cycle. This increases the fuel mass and thus the mean effective pressure.

[0005] Turbocharging is a suitable method for increasing the power output of an internal combustion engine without changing its displacement, or for reducing the displacement while maintaining the same power output. In either case, turbocharging leads to increased power output per unit volume and a more favorable power-to-weight ratio. Reducing the displacement allows the load spectrum to be shifted towards higher loads, resulting in lower specific fuel consumption. Turbocharging, in combination with a suitable transmission design, can also achieve a so-called downspeeding effect, which likewise leads to lower specific fuel consumption.

[0006] Turbocharging therefore supports the ongoing effort in the development of internal combustion engines to minimize fuel consumption, i.e., to improve the efficiency of the internal combustion engine.

[0007] A turbocharger is frequently used for forced induction, in which a compressor and a turbine are mounted on the same shaft. The hot exhaust gas stream is fed to the turbine and expands within it, releasing energy and setting the shaft in motion. The energy transferred from the exhaust gas stream to the turbine and ultimately to the shaft is used to drive the compressor, which is also mounted on the shaft. The compressor forces and compresses the intake air, thus supercharging the cylinders. Advantageously, an intercooler is installed downstream of the compressor in the intake system to cool the compressed intake air before it enters at least one cylinder. The cooler lowers the temperature and thus increases the density of the intake air, contributing to better cylinder filling, i.e., a greater air mass. Compression is achieved through cooling.

[0008] The advantage of an exhaust gas turbocharger compared to a turbocharger driven by an auxiliary drive is that an exhaust gas turbocharger utilizes the exhaust energy of the hot exhaust gases, while a turbocharger obtains the energy required for its drive directly or indirectly from the internal combustion engine and thus, at least as long as the drive energy does not come from energy recovery, adversely affects, i.e. reduces, the efficiency.

[0009] If it is not a turbocharger powered by an electric motor, i.e., electrically driven, a mechanical or kinematic connection for power transmission between the turbocharger and the internal combustion engine is regularly required, which also affects the packaging in the engine compartment.

[0010] The advantage of a supercharger over an exhaust gas turbocharger is that the supercharger can always generate and provide the required boost pressure, regardless of the operating condition of the internal combustion engine. This is particularly true for a supercharger that is electrically driven by an electric motor and therefore independent of the crankshaft speed.

[0011] According to current technology, increasing power output using exhaust gas turbocharging across all engine speed ranges is difficult. A significant drop in torque is observed below a certain engine speed. This torque drop becomes understandable when considering that the boost pressure ratio depends on the turbine pressure ratio and / or turbine power. Reducing the engine speed results in a lower exhaust gas mass flow and thus a lower turbine pressure ratio and / or turbine power. Consequently, the boost pressure ratio also decreases at lower engine speeds. This is equivalent to a drop in torque.

[0012] The internal combustion engine that is the subject of the present invention has a compressor for the purpose of charging, wherein, within the scope of the present invention, the term compressor can encompass both a supercharger driven by an auxiliary drive and a compressor of an exhaust gas turbocharger.

[0013] Another fundamental goal is to reduce pollutant emissions. A wide range of measures are needed to comply with future emission limits.

[0014] Exhaust gas recirculation serves to reduce raw nitrogen oxide emissions. The recirculation rate x AGR is determined to x AGR = m AGR / (m AGR + m Frischluft ), where m AGR the mass of recirculated exhaust gas and m Frischluft This refers to the supplied fresh air. Any oxygen or air recirculated via exhaust gas recirculation must also be taken into account.

[0015] The internal combustion engine according to the invention, which is turbocharged by means of a compressor, is also equipped with exhaust gas recirculation, wherein the recirculation line branching off from the exhaust gas discharge system opens into the intake system upstream of the compressor at a junction, as is regularly the case with a low-pressure EGR, in which exhaust gas is recirculated to the intake side after it has already flowed through a turbine arranged in the exhaust gas discharge system. For this purpose, the low-pressure EGR comprises a recirculation line that branches off from the exhaust gas discharge system downstream of the turbine and preferably opens into the intake system upstream of the compressor.

[0016] Problems can arise when exhaust gas recirculation is activated if exhaust gas is introduced into the intake system upstream of the compressor. Condensation can form when recirculated hot exhaust gas comes into contact with and mixes with cooler fresh air.

[0017] The problem described above worsens with increasing recirculation rate, since the proportions of individual exhaust gas components in the charge air inevitably increase with the increasing volume of recirculated exhaust gas, particularly the proportion of water contained in the exhaust gas. In some cases, the volume of exhaust gas recirculated via low-pressure EGR is limited to prevent or reduce condensation.

[0018] The low-pressure EGR described above can be combined with a high-pressure EGR.

[0019] Exhaust gas recirculation (EGR), particularly low-pressure EGR systems, also presents difficulties in generating the necessary pressure differential between the exhaust and intake systems to achieve high recirculation rates. This often necessitates additional measures. According to current technology, a shut-off element is therefore provided in the exhaust system to stagnate the exhaust gas and increase the exhaust pressure, and / or a shut-off element is provided in the intake system to reduce the pressure on the intake side. Both measures are rather inefficient in terms of energy consumption.

[0020] In particular, an intake-side throttling of the charge air must be considered disadvantageous with regard to the turbocharging of the internal combustion engine.

[0021] Another problem with recirculating exhaust gas into the intake system upstream of a compressor is that turbulence is created when the exhaust gas is introduced into the fresh air, significantly disrupting the airflow to the compressor. This negatively affects the compressor's efficiency and pumping behavior, which is why, according to current technology, the exhaust gas is introduced into the intake system at a sufficient distance from the compressor. A straight, i.e., curvature-free, design of the intake system upstream of the compressor reduces the adverse flow effects caused by the introduction of recirculated exhaust gas.

[0022] Both introducing the exhaust gas at a considerable distance from the compressor and designing the intake system in a straight line upstream of the compressor are not feasible with compact, small-volume internal combustion engines, which is why other concepts are needed to mitigate the adverse flow effects caused by introducing recirculated exhaust gas into the intake system.

[0023] In this context, it should be taken into account that the importance and market share of small-volume internal combustion engines is increasing, which is why solving the problem described is highly relevant.

[0024] DE 11 2017 006 443 T5 describes an internal combustion engine with exhaust gas recirculation, in which a guide element is placed in the intake pipe, which separates the charge air and the recirculated exhaust gas section by section at the junction.

[0025] DE 20 2015 104 455 U1 also describes an internal combustion engine of the above type with exhaust gas turbocharging, in which a flap for exhaust gas recirculation arranged in the intake system, which is also to be regarded and functions as a guide element, is not flat but curved.

[0026] Against this background, it is an object of the present invention to provide a turbocharged internal combustion engine according to the preamble of claim 1 which is improved with regard to exhaust gas recirculation.

[0027] The first subtask is solved by a turbocharged internal combustion engine with - an intake system for supplying charge air, - an exhaust gas removal system for removing exhaust gas, - at least one compressor arranged in an intake line of the intake system, which is equipped with at least one impeller mounted in a housing on a rotatable shaft, and - an exhaust gas recirculation system comprising a recirculation line branching off from the exhaust gas discharge system and leading upstream of the at least one impeller into the intake system by forming a node, wherein the node is formed and arranged in the vicinity of the at least one impeller by forming a distance Δ, at the - the intake pipe upstream of the compressor has a bend by an angle γ, forming a convex outer side and a concave inner side, with the node being located on the side of the intake pipe where the concave inner side is formed, and which is characterized by the fact that - the intake pipe upstream of the compressor has a bend by an angle γ, forming a convex outer side and a concave inner side, with the node being located on the side of the intake pipe where the concave inner side is formed.

[0028] The intake manifold of the internal combustion engine according to the invention has a bend upstream of the compressor, as is regularly found in small-displacement internal combustion engines. This means that the intake system does not have a sufficiently long, straight section upstream of the compressor, which would be preferable with regard to exhaust gas recirculation. Introducing the exhaust gas at a considerable distance from the compressor is also not an option in this case.

[0029] To reduce the adverse flow effects caused by introducing recirculated exhaust gas into the intake system, the concept according to the invention utilizes the fact that the charge air detaches from the concave inner surface when flowing through the bend.

[0030] The separation of the charge air flow from the inside of the bend is accompanied by a constriction and acceleration of the charge air flow, which is associated with a pressure drop.

[0031] Downstream of the separation point, the accelerated charge air flow acts like the driving medium of a jet pump, entraining the recirculated exhaust gas through momentum transfer. As the exhaust gas is accelerated by the charge air flow, its static pressure drops. This pressure drop creates a suction effect, drawing more exhaust gas from the recirculation line into the intake system, i.e., recirculating it. In this way, higher recirculation rates can be achieved, meaning larger volumes of exhaust gas can be recirculated.

[0032] The mixing of the charge air with the exhaust gas is facilitated and supported by the fact that the charge air flow slows down when the exhaust gas is carried along and the static pressure increases again, causing the charge air jet to widen.

[0033] Advantageous are embodiments in which the intake line between the at least one impeller of the compressor and the bend is straight.

[0034] According to the invention, a guide element is placed in the intake pipe, which separates the charge air and the recirculated exhaust gas at least section by section at the junction.

[0035] In this system, a guide element separates the exhaust gas and the charge air or fresh air at the junction for a certain distance. The guide element, which is preferably movable and tongue-shaped, serves to enhance the jet pumping effect, so that recirculated exhaust gas can be conveyed even more effectively into the intake system.

[0036] The guide element is arc-shaped, with the arc-shaped guide element and the bend being oriented in the same way. The shape of the guide element then follows the flow pattern of the charge air resulting from the bend.

[0037] The internal combustion engine according to the invention solves the problem underlying the invention, namely providing a turbocharged internal combustion engine according to the preamble of claim 1, which is improved with regard to exhaust gas recirculation.

[0038] Further advantageous embodiments of the internal combustion engine according to the invention are discussed in connection with the dependent claims.

[0039] The following embodiments define the proximity or distance Δ of the node to the at least one compressor impeller. Depending on the compactness of the respective small-displacement internal combustion engine, the node is positioned more or less close to the compressor. The same applies analogously to the bend, which is also formed and arranged near the at least one impeller, creating a distance that is typically short in small-displacement internal combustion engines.

[0040] Advantageous are embodiments of the turbocharged internal combustion engine in which the distance Δ is given by: 2.5D V ≤ Δ ≤ 5.0D V , where D V specifies the diameter of at least one impeller.

[0041] Advantageous are embodiments of the turbocharged internal combustion engine in which the distance Δ is given by: 1.5D V < Δ ≤ 2.5D V , where D V specifies the diameter of at least one impeller.

[0042] Advantageous are embodiments of the turbocharged internal combustion engine in which the distance Δ is: 0.5D V < Δ ≤ 1.5D V , where D V specifies the diameter of at least one impeller.

[0043] Advantageous are embodiments of the turbocharged internal combustion engine in which the distance Δ is: Δ < 0.5D V , where D V specifies the diameter of at least one impeller.

[0044] The following embodiments define the bend of the intake manifold in more detail, using an angle γ that indicates the angle by which the charge air flow is deflected as it passes through the bend. The intake manifold can be bent more or less sharply depending on the compactness and design of the respective small-displacement internal combustion engine.

[0045] Advantageous are embodiments of the supercharged internal combustion engine in which the following applies to the angle γ: γ ≥ 20°.

[0046] Advantageous are embodiments of the supercharged internal combustion engine in which the following applies to the angle γ: γ ≥ 35°.

[0047] Advantageous are embodiments of the supercharged internal combustion engine in which the following applies to the angle γ: γ ≥ 45°.

[0048] Advantageous are embodiments of the supercharged internal combustion engine in which the following applies to the angle γ: γ ≥ 60°.

[0049] Advantageous are embodiments of the supercharged internal combustion engine in which the node is arranged between the at least one impeller and the bend.

[0050] Also advantageous are embodiments of the turbocharged internal combustion engine in which the node is located in the bend.

[0051] The arrangement of the junction relative to the bend also depends on the angle γ by which the charge air flow is deflected as it passes through the bend. The angle γ influences where the charge air flow separates from the inside of the bend. Therefore, the angle γ must be considered when positioning the junction where the return line enters the intake manifold and where the jet pump effect can be used most effectively for exhaust gas flow.

[0052] Advantageous embodiments of the turbocharged internal combustion engine are those in which at least one exhaust gas turbocharger is provided, comprising a turbine arranged in the exhaust gas discharge system and a compressor arranged in the intake system. With regard to the foregoing embodiment, reference is made to the explanations already given in connection with exhaust gas turbocharging, in particular the advantages highlighted therein.

[0053] In this context, advantageous are embodiments of the turbocharged internal combustion engine in which the at least one compressor is the compressor of the at least one exhaust gas turbocharger.

[0054] Advantageous are embodiments of the turbocharged internal combustion engine in which the return line branches off from the exhaust gas discharge system downstream of the turbine of the at least one exhaust gas turbocharger according to a low-pressure EGR.

[0055] In contrast to a high-pressure EGR system, which introduces exhaust gas extracted from the exhaust system upstream of the turbine into the intake system, preferably downstream of the compressor, a low-pressure EGR system recirculates exhaust gas that has already passed through the turbine back to the intake side. For this purpose, the low-pressure EGR system includes a recirculation line that branches off from the exhaust system downstream of the turbine and connects to the intake system upstream of the compressor.

[0056] The main advantage of low-pressure EGR over high-pressure EGR is that the exhaust gas flow introduced into the turbine is not reduced by the amount of recirculated exhaust gas. The entire exhaust gas flow is always available at the turbine to generate a sufficiently high boost pressure.

[0057] The exhaust gas, which is recirculated to the intake side via low-pressure EGR and preferably cooled, is mixed with fresh air upstream of the compressor. The resulting mixture of fresh air and recirculated exhaust gas forms the charge air or combustion air, which is supplied to the compressor and compressed.

[0058] Advantageous designs of the turbocharged internal combustion engine can include a first shut-off element in the exhaust system downstream of the branch point of the recirculation line. This first shut-off element can be used to increase the exhaust pressure upstream of the shut-off element in the exhaust system, thereby increasing the pressure differential between the exhaust system and the intake system. This facilitates the achievement of high recirculation rates, which require a greater pressure differential.

[0059] In certain cases, it can be advantageous to design the turbocharged internal combustion engine in which a second shut-off element is arranged in the intake system upstream of the junction. This second shut-off element serves to reduce the pressure in the intake system on the inlet side and can thus – like the first shut-off element – ​​contribute to an increase in the pressure differential between the exhaust system and the intake system.

[0060] In this context, embodiments of the turbocharged internal combustion engine in which neither a first nor a second shut-off element is provided are particularly advantageous. Because the jet pump effect is used to convey the recirculated exhaust gas according to the invention, shut-off elements can generally be dispensed with or their use reduced in terms of efficiency.

[0061] Advantageous are embodiments of the turbocharged internal combustion engine in which the turbine of the at least one exhaust gas turbocharger has a variable turbine geometry.

[0062] Variable turbine geometry increases the flexibility of turbocharging. It allows for stepless adjustment of the turbine geometry to the respective operating point of the internal combustion engine or to the current exhaust gas mass flow. In contrast to a turbine with a fixed geometry, a more or less satisfactory turbocharging effect can be achieved over a wide speed and load range.

[0063] Advantageous are embodiments of the turbocharged internal combustion engine in which the guide element is pivotably mounted upstream of the junction. This embodiment allows adjustment of the guide element and thus adaptation to different exhaust gas volumes, which are associated with different flow velocities and flow conditions.

[0064] Advantageous are embodiments of the turbocharged internal combustion engine in which the guide element is pivotably mounted near a wall section of the intake system.

[0065] Advantageous are embodiments of the turbocharged internal combustion engine in which an intercooler is arranged in the intake system downstream of the at least one compressor.

[0066] The invention is described below using two exemplary embodiments according to the Fig. 1a and Fig. 1b is described in more detail. This shows: Fig. 1a schematically a fragment of an intake system of a first embodiment of the supercharged internal combustion engine, and Fig. 1b schematically a fragment of an intake system of a second embodiment of the supercharged internal combustion engine.

[0067] Fig. Figure 1a schematically shows a fragment of an intake system 1 of a first embodiment of the supercharged internal combustion engine.

[0068] The intake system 1 serves to supply charge air to the cylinders of the internal combustion engine. A compressor 2 is arranged in the intake line 1a of the intake system 1. This compressor comprises an impeller mounted in a housing on a rotatable shaft and serves to supercharge the internal combustion engine.

[0069] Furthermore, the internal combustion engine is equipped with an exhaust gas recirculation system 3. A return line 3a of the exhaust gas recirculation system 3, which branches off from the exhaust gas discharge system, opens into the intake system 1 upstream of the compressor 2, i.e., the compressor impeller, forming a junction 3b. The junction 3b is located near the impeller. In this case, the distance Δ to the impeller is less than 1.5D. V , where D V specifies the diameter of the impeller.

[0070] The intake pipe 1a upstream of the compressor 2 has a bend 4 at an angle γ, forming a convex outer surface 4a and a concave inner surface 4b. The junction 3b is located between the impeller and the bend 4 and is positioned on the side of the intake pipe 1a where the concave inner surface 4b of the bend 4 is formed. This allows the jet pump effect to be used to convey the recirculated exhaust gas.

[0071] As the charge air flows through bend 4, it detaches from the concave inner surface 4b, thus constricting and accelerating the charge air flow. The static pressure in the charge air drops.

[0072] Downstream of the separation point, the accelerated charge air flow acts as a driving medium for the recirculated exhaust gas, which is carried along by momentum transfer, i.e., accelerated and thus conveyed. The static pressure drops in the accelerated exhaust gas, which assists the conveying process by creating a suction effect. In this way, higher recirculation rates can be achieved, meaning larger volumes of exhaust gas can be recirculated.

[0073] In the illustrated embodiment, a tongue-like guide element 5 is placed in the intake line 1a, which separates the charge air and the recirculated exhaust gas section by section at junction 3b.

[0074] The arc-shaped guide element 5 is oriented in the same way as the bend 4 and thus adopts the flow pattern of the charge air resulting from bend 4. The guide element 5 serves to enhance the jet pump effect, so that the exhaust gas from the internal combustion engine can be recirculated even more effectively and fed into the intake system 1.

[0075] In this case, the guide element 4 is pivotably mounted, with the mounting 5a of the guide element 5 being located upstream of node 3b near a wall section 1b of the intake system 1. This allows the guide element 5 to be adjusted and thus adapted to different exhaust gas volumes, different flow velocities and changing flow conditions in the intake system 1.

[0076] Fig. Figure 1b schematically shows a fragment of an intake system 1 of a second embodiment of the turbocharged internal combustion engine. In contrast to Fig. 1a is the one in Fig. The embodiment shown in 1b is not equipped with a guide element. Reference sign 1 Intake system 1a Intake pipe 1b Wall section of the intake system 2 compressors 3 Exhaust gas recirculation 3a Return line 3b Junction 4 bend 4a convex outer side 4b concave inside 5 guide element 5a Storage of the guide element Δ Distance of the node to the wheel EGR Exhaust Gas Recirculation γ Angle of bending D V Diameter of at least one impeller m AGR Mass of recirculated exhaust gas m Frischluft Mass of supplied fresh air x AGR Exhaust gas recirculation rate

Claims

[1] Supercharged internal combustion engine with - an intake system (1) for supplying charge air, - an exhaust gas removal system for removing exhaust gas, - at least one compressor (2) arranged in an intake line (1a) of the intake system (1), which is equipped with at least one impeller mounted in a housing on a rotatable shaft, and - an exhaust gas recirculation (3) comprising a recirculation line (3a) branching off from the exhaust gas discharge system and opening upstream of the at least one impeller into the intake system (1) forming a node (3b), wherein the node (3b) is formed and arranged in the vicinity of the at least one impeller forming a distance Δ, in which - the intake pipe (1a) upstream of the compressor (2) has a bend (4) by an angle γ and forms a convex outer surface (4a) and a concave inner surface (4b), wherein the node (3b) is placed on the side of the intake pipe (1a) on which the concave inner surface (4b) is formed, characterized by , that a guide element (5) is placed in the intake pipe (1a) which separates the charge air and the recirculated exhaust gas at least sectionally at the junction (3b), wherein - the guiding element (5) is arc-shaped, and - the arc-shaped guide element (5) and the bend (4) are oriented in the same way. [2] Supercharged internal combustion engine according to claim 1, characterized by , that for the distance Δ the following holds: 2.5D V ≤ Δ ≤ 5.0D V , where D V specifies the diameter of at least one impeller. [3] Supercharged internal combustion engine according to claim 1, characterized by, that for the distance Δ the following holds: 1.5D V < Δ ≤ 2.5D V , where D V specifies the diameter of at least one impeller. [4] Supercharged internal combustion engine according to claim 1, characterized by , that the distance Δ is: 0.5D V < Δ ≤ 1.5D v , where D V specifies the diameter of at least one impeller. [5] Supercharged internal combustion engine according to claim 1, characterized by , that for the distance Δ: Δ < 0.5D V , where D V specifies the diameter of at least one impeller. [6] Supercharged internal combustion engine according to any of the preceding claims, characterized by , that for the angle γ: γ ≥ 20°. [7] Supercharged internal combustion engine according to any one of claims 1 to 5, characterized by , that for the angle γ: γ ≥ 35°. [8] Supercharged internal combustion engine according to any one of claims 1 to 5, characterized by , that for the angle γ: γ ≥ 45°. [9] Supercharged internal combustion engine according to any one of claims 1 to 5, characterized by , that for the angle γ: γ ≥ 60°. [10] Supercharged internal combustion engine according to any of the preceding claims, characterized by , that the node (3b) is located between the at least one wheel and the bend (4). [11] Supercharged internal combustion engine according to any one of claims 1 to 9, characterized by , that the node (3b) is located in the bend (4). [12] Supercharged internal combustion engine according to any of the preceding claims, characterized by , that at least one exhaust gas turbocharger is provided, comprising a turbine arranged in the exhaust gas discharge system and a compressor (2) arranged in the intake system (1). [13] Supercharged internal combustion engine according to claim 12, characterized by , that the at least one compressor (2) is the compressor (2) of the at least one exhaust gas turbocharger. [14] Supercharged internal combustion engine according to claim 12 or 13, characterized by , that the return line (3a) branches off downstream of the turbine of the at least one exhaust gas turbocharger from the exhaust gas discharge system. [15] Supercharged internal combustion engine according to any of the preceding claims, characterized by , that the guide element (5) is pivotably mounted upstream of the node (3b). [16] Supercharged internal combustion engine according to claim 15, characterized by , that the guide element (5) is pivotably mounted near a wall section (1b) of the intake system (1).

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