DE102018221147B4 - Supercharged internal combustion engine with a compressor and a guide device arranged upstream of the compressor - Google Patents

Abstract

Supercharged internal combustion engine with - an intake system (1) for supplying charge air, - an exhaust gas discharge system for discharging exhaust gas, - at least one compressor (2) arranged for compressing a charge air flow in the intake system (1), which has at least one compressor housing (2c). an impeller (2b) mounted on a rotatable shaft (2a) and equipped with rotor blades and having an inlet area (3) which runs coaxially to the shaft (2a) of the compressor (2) and is designed, - an exhaust gas recirculation system comprising a recirculation line which runs from exhaust gas removal system and opens into the intake system (1) upstream of the at least one impeller (2b) forming a node, and- a guide device (4) which is arranged upstream of the at least one compressor impeller (2b) in the intake system (1) and which extends at least between the at least one compressor impeller (2b) and the node, characterized in that- the Guide device (4) comprises an inner sleeve (4a) and a plurality of strip-like guide elements (4b), the strip-like guide elements (4b) spiraling around the inner sleeve (4a) at least in regions.

Description

• - einem Ansaugsystem zum Zuführen von Ladeluft,
• - einem Abgasabführsystem zum Abführen von Abgas,
• - mindestens einem zur Kompression einer Ladeluftströmung im Ansaugsystem angeordneten Verdichter, der mindestens ein in einem Verdichtergehäuse auf einer drehbaren Welle gelagertes und mit Laufschaufeln ausgestattetes Laufrad umfasst und einen Eintrittsbereich aufweist, der koaxial zur Welle des Verdichters verläuft und ausgebildet ist,
• - einer Abgasrückführung umfassend eine Rückführleitung, die vom Abgasabführsystem abzweigt und stromaufwärts des mindestens einen Laufrades unter Ausbildung eines Knotenpunktes in das Ansaugsystem mündet, und
• - einer Leiteinrichtung, die stromaufwärts des mindestens einen Verdichterlaufrades im Ansaugsystem angeordnet ist und die sich zumindest auch zwischen dem mindestens einen Verdichterlaufrad und dem Knotenpunkt erstreckt.

The invention relates to a supercharged internal combustion engine

• - an intake system for supplying charge air,
• - an exhaust gas discharge system for discharging exhaust gas,
• - at least one compressor arranged in the intake system for compressing a charge air flow, which comprises at least one impeller mounted in a compressor housing on a rotatable shaft and equipped with rotor blades and having an inlet area which runs and is configured coaxially to the shaft of the compressor,
• - An exhaust gas recirculation comprising a recirculation line, which branches off from the exhaust gas discharge system and upstream of the at least one impeller, forming a node, opens into the intake system, and
• - A guide device which is arranged upstream of the at least one compressor impeller in the intake system and which also extends at least between the at least one compressor impeller and the node.

An internal combustion engine of the type mentioned is used, for example, as a motor vehicle drive. In the context of the present invention, the term internal combustion engine refers to diesel engines and Otto engines, but also hybrid internal combustion engines, i.e. internal combustion engines that are operated with a hybrid combustion process, and hybrid drives that, in addition to the internal combustion engine, use at least one other torque source to drive a motor vehicle include, for example, an electric machine which can be drive-connected or is drive-connected to the internal combustion engine and which delivers power instead of the internal combustion engine or in addition to the internal combustion engine.

Supercharged internal combustion engines are becoming increasingly important, with supercharging primarily being a method of increasing performance in which the air required for the engine's combustion process is compressed, which means that a larger air mass can be supplied to each cylinder per working cycle. As a result, the fuel mass and thus the intermediate pressure can be increased.

Supercharging is a suitable means of increasing the performance of an internal combustion engine with the same displacement or reducing the displacement with the same performance. In any case, supercharging leads to an increase in installation space performance and a more favorable mass of power. If the displacement is reduced, the load collective can be shifted towards higher loads, at which specific fuel consumption is lower. Through supercharging in combination with a suitable gear design, so-called downspeeding can also be achieved, with which a lower specific fuel consumption can also be achieved.

Supercharging consequently supports the constant effort in the development of internal combustion engines to minimize fuel consumption, i.e. to improve the efficiency of the internal combustion engine.

An exhaust gas turbocharger is often used for charging, in which a compressor and a turbine are arranged on the same shaft. The hot exhaust gas flow is fed to the turbine and expands in the turbine, releasing energy, causing the shaft to rotate. The energy given off by the exhaust gas flow to the turbine and finally to the shaft is used to drive the compressor, which is also arranged on the shaft. The compressor conveys and compresses the charge air supplied to it, which means that the cylinders are charged.

Advantageously, a charge air cooler is provided downstream of the compressor in the intake system, with which the compressed charge air is cooled before it enters the at least one cylinder. The cooler lowers the temperature and thus increases the density of the charge air, so that the cooler also contributes to better filling of the cylinders, i.e. to a larger air mass. Compression occurs through cooling.

The advantage of an exhaust gas turbocharger compared to a - mechanical - charger is that an exhaust gas turbocharger uses the exhaust gas energy of the hot exhaust gases, while a mechanical charger obtains the energy required for its drive directly or indirectly from the internal combustion engine. As a rule, a mechanical connection, such as a traction drive, is required for power transmission between the charger and the internal combustion engine.

The advantage of a mechanical supercharger compared to an exhaust gas turbocharger is that the mechanical supercharger can generally generate and make available the required boost pressure independently of the current operating state of the internal combustion engine, especially at low crankshaft speeds. This applies in particular to a charger that can be driven by an electric machine and can therefore also be referred to as an electric charger.

According to the state of the art, it is difficult to increase the power in all speed ranges by means of exhaust gas turbocharging. A greater drop in torque is observed when the speed falls below a certain level. This drop in torque becomes understandable when it is taken into account that the boost pressure ratio depends on the turbine pressure ratio. If the engine speed is reduced, this leads to a smaller exhaust gas mass flow and thus to a lower turbine pressure ratio, which is why the boost pressure ratio also decreases towards lower engine speeds. This is equivalent to a drop in torque.

In addition to an exhaust gas turbocharger, a mechanical or electrical supercharger can in principle also be provided. Since exhaust gas turbocharging is cost-intensive, in particular when using a plurality of exhaust gas turbochargers, charging by means of a mechanical or electrical supercharger can also be carried out instead of exhaust gas turbocharging. The advantages are those already mentioned above.

The supercharged internal combustion engine, which is the subject of the present invention, has at least one compressor, which can be a mechanical supercharger, an electric supercharger or the compressor of an exhaust gas turbocharger, for the purpose of supercharging.

Problems can arise upstream of the compressor if the internal combustion engine—like the internal combustion engine according to the invention—is equipped with exhaust gas recirculation, in which the exhaust gas is introduced into the intake system upstream of the compressor. Condensation can form. There are several scenarios to consider.

First, condensate can form when recirculated hot exhaust gas meets and mixes with cool fresh air. The exhaust gas cools down, while the temperature of the fresh air is raised. The temperature of the mixture of fresh air and recirculated exhaust gas, i.e. the charge air temperature, is below the exhaust gas temperature of the recirculated exhaust gas. As part of the cooling of the exhaust gas, liquids previously contained in the exhaust gas in gaseous form, in particular water, can condense out if the dew temperature of a component of the gaseous charge air flow is not reached.

Condensate forms in the free charge air flow, with impurities in the charge air often being the starting point for the formation of condensate droplets.

On the other hand, condensate can form when recirculated hot exhaust gas or the charge air hits the inner wall of the intake system or the inner wall of the compressor housing, since the wall temperature is usually below the dew temperature of the relevant gaseous components.

The problems described above are exacerbated as the recirculation rate increases, since the proportions of the individual exhaust gas components in the charge air inevitably increase with the increase in the recirculated quantity of exhaust gas, in particular the proportion of water contained in the exhaust gas. According to the prior art, the amount of exhaust gas recirculated by means of low-pressure EGR is therefore often limited in order to prevent or reduce condensation. The necessary limitation of the low-pressure EGR on the one hand and the high exhaust gas recirculation rates required for a significant reduction in nitrogen oxide emissions on the other lead to different objectives when measuring the recirculated exhaust gas quantity. The legal requirements for reducing nitrogen oxide emissions illustrate the high relevance of this problem in practice.

The effects described above in connection with the recirculation of hot exhaust gas also apply in an analogous manner to the ventilation flow, which is usually taken from the crankcase and introduced into the intake system upstream of the compressor.

Condensate and condensate droplets are undesirable and lead to increased noise emissions in the intake system, possibly to damage to the blades of the at least one compressor impeller. The latter is associated with a reduction in the efficiency of the compressor.

Even if, as part of a low-pressure EGR, exhaust gas that has undergone exhaust gas aftertreatment, in particular in a particle filter, is preferably fed through the compressor, deposits in the compressor can change the geometry of the compressor, in particular the flow cross sections, and thus the efficiency of the compressor deteriorate cannot be completely avoided.

the US 8,297,922 B1 describes a hood that is intended to protect the impeller of the compressor from damage and deposits. The hood has two surfaces, with a first surface forming the front of the hood that is exposed to the charge air flow. A second surface, opposite the first surface and forming the rear of the hood, faces the impeller. The back of the Hood is designed to fit snugly to the front of the impeller so that no voids are formed between the rear of the assembled hood and the front of the impeller. Like the impeller of the compressor, the front side of the hood is designed with a view to aerodynamic aspects and the efficiency of the compressor.

At the in the US 8,297,922 B1 described hood is a complex and costly concept. The hood encloses the impeller of the compressor as a whole at the front and has to be manufactured with a precise fit, which is why high demands are placed on production. Apparently the in the US 8,297,922 B1 described hood designed as a wearing part, which is to be replaced as part of maintenance work. This must be taken into account in particular with regard to the costs of the proposed protective measure.

In addition, the voluminous hood has a corresponding weight, which is to be regarded as very disadvantageous. It must be taken into account that the hood rotates with the rotating impeller of the compressor and very high speeds are achieved, which means that correspondingly high forces act on the compressor shaft and in the bearing. Since the heavy hood also has to be accelerated and decelerated with the rotating impeller of the compressor, the response behavior of the compressor deteriorates in a not inconsiderable way.

the DE 10 2014 216 162 B4 describes annular channels that spirally surround a guide device in an intake system of a supercharged internal combustion engine.

Against the background of what has been said, it is the object of the present invention to provide a supercharged internal combustion engine according to the preamble of claim 1, with which the disadvantages known from the prior art are overcome and with which, in particular, damage to the compressor due to condensation is counteracted.

• - einem Ansaugsystem zum Zuführen von Ladeluft,
• - einem Abgasabführsystem zum Abführen von Abgas,
• - mindestens einem zur Kompression einer Ladeluftströmung im Ansaugsystem angeordneten Verdichter, der mindestens ein in einem Verdichtergehäuse auf einer drehbaren Welle gelagertes und mit Laufschaufeln ausgestattetes Laufrad umfasst und einen Eintrittsbereich aufweist, der koaxial zur Welle des Verdichters verläuft und ausgebildet ist,
• - einer Abgasrückführung umfassend eine Rückführleitung, die vom Abgasabführsystem abzweigt und stromaufwärts des mindestens einen Laufrades unter Ausbildung eines Knotenpunktes in das Ansaugsystem mündet, und
• - einer Leiteinrichtung, die stromaufwärts des mindestens einen Verdichterlaufrades im Ansaugsystem angeordnet ist und die sich zumindest auch zwischen dem mindestens einen Verdichterlaufrad und dem Knotenpunkt erstreckt,

die dadurch gekennzeichnet ist, dass

• - die Leiteinrichtung eine innenliegende Hülse und mehrere leistenartige Leitelemente umfasst, wobei die leistenartigen Leitelemente die innenliegende Hülse außen zumindest bereichsweise spiralförmig umlaufen.

This task is solved by a supercharged internal combustion engine

• - an intake system for supplying charge air,
• - an exhaust gas discharge system for discharging exhaust gas,
• - at least one compressor arranged in the intake system for compressing a charge air flow, which comprises at least one impeller mounted in a compressor housing on a rotatable shaft and equipped with rotor blades and having an inlet area which runs and is configured coaxially to the shaft of the compressor,
• - An exhaust gas recirculation comprising a recirculation line, which branches off from the exhaust gas discharge system and upstream of the at least one impeller, forming a node, opens into the intake system, and
• - a guide device which is arranged upstream of the at least one compressor impeller in the intake system and which also extends at least between the at least one compressor impeller and the node,

which is characterized in that

• - The guiding device comprises an inner sleeve and a plurality of strip-like guiding elements, the strip-like guiding elements encircling the inner sleeve on the outside at least in regions in a spiral manner.

Embodiments of the supercharged internal combustion engine are advantageous in which the strip-like guide elements spirally encircle the inner sleeve in such a way that the charge air flow guided using the guide elements has or is forced to have a speed component in the direction of the peripheral speed of the rotating compressor impeller.

The internal combustion engine according to the invention is not intended to counteract the formation of condensate in the intake system or to collect and discharge the separated condensate upstream of the compressor. I.e. the problem resulting from the formation of condensate should not be countered causally in this case.

Rather, the disadvantageous effects of condensate formation should be reduced or eliminated by suitable measures, in particular damage to the blades of the at least one compressor impeller should be avoided.

For this reason, according to the invention, the charge air flow passes through a guide device before it hits the at least one compressor impeller. The guiding device according to the invention comprises an internal sleeve, inside which a part—preferably the majority—of the charge air is guided centrally in the intake system. This part of the charge air flow is also referred to below as the inner charge air flow. A remaining part of the charge air flows around the inner sleeve on the outside and flows through an outer channel between the inner sleeve and the inner wall of the intake system is formed and is regularly ring-shaped. This part of the charge air flow is also referred to below as the outer charge air flow.

The outer charge air flow regularly has a high proportion of condensate or many condensate droplets. This can have different causes. On the one hand, the outer charge air flow sweeps over the inner wall of the intake system, on which condensate and condensate droplets form and collect, which get into the outer charge air flow or are entrained by this outer charge air flow. On the other hand, the recirculation line of an exhaust gas recirculation or the ventilation line of a crankcase ventilation opens into the intake system, specifically with the formation of an inlet opening in the inner wall of the intake system. As a result, the recirculated exhaust gases or the ventilation flow get into the outer charge air flow, preferably if the inner sleeve covers the inlet opening or protrudes far enough into the intake system upstream of the inlet opening.

According to the invention, guide elements of the guide device are arranged in the outer channel between the inner sleeve and the inner wall of the intake system, which encircle the inner sleeve on the outside and at least in regions in a spiral shape.

When flowing through the strip-like guide elements, the outer charge air flow, together with the condensate or the condensate droplets, is forced to have a velocity component in the direction of the peripheral speed of the rotating compressor impeller, which reduces the relative speed between the impeller and the outer charge air flow entering the impeller, in particular the relative speed between the impeller and the condensate droplets hitting the impeller is reduced or minimized.

The reduction in the relative speeds has the advantageous effect that in particular the condensate droplets striking the impeller have or bring with them a comparatively small impulse, as a result of which the risk of damage to the blades of the at least one compressor impeller is reduced or eliminated.

Damage to the blade edges by condensate and an associated reduction in compressor efficiency are prevented.

It is not necessary to limit the amount of exhaust gas that is recirculated, so that high recirculation rates can be achieved in order to significantly reduce nitrogen oxide emissions.

The internal combustion engine according to the invention achieves the object underlying the invention, namely providing a supercharged internal combustion engine with which the disadvantages known from the prior art are overcome and with which damage to the compressor as a result of condensation is counteracted in particular.

A strip-like guide element is characterized in that the length of the guide element—as with a skirting board—exceeds the width and depth of the guide element many times over.

The guide device according to the invention is also suitable for retrofitting compressors that are already on the market.

Further advantageous embodiments of the supercharged internal combustion engine are discussed in connection with the subclaims.

Embodiments of the supercharged internal combustion engine are advantageous in which at least one strip-like guide element is fastened to an inner wall of the intake system.

A strip-like guiding element, several guiding elements or all guiding elements can be fastened to the inner wall of the intake system, for example by the at least one guiding element being formed in one piece with the intake system, whereby an integral connection is realized.

However, embodiments of the supercharged internal combustion engine in which at least one strip-like guide element is fastened to the inner sleeve are particularly advantageous.

A strip-like guiding element, several guiding elements or all guiding elements can also be fastened to the inner sleeve, for example by the at least one guiding element being formed in one piece with the inner sleeve, so that the inner sleeve and the at least one strip-like guiding element form a monolithic component, i.e. in one piece are trained.

The above embodiment is particularly suitable for retrofitting compressors that are already on the market.

Are advantageous in this context - as already mentioned - embodiments of the supercharged internal combustion engine, in which at least one strip-like guide element and the inner sleeve are integrally formed in the way that the at least one strip-like guide element and the inner sleeve form a monolithic component.

Embodiments of the supercharged internal combustion engine are advantageous in which at least one strip-like guide element has a wing-shaped cross section at least in regions. The guide element is then preferably thickened on its side facing the sleeve and becomes thinner or narrower with increasing distance from the sleeve.

Embodiments of the supercharged internal combustion engine are advantageous in which each strip-like guide element has a leading edge facing the charge air flow.

In this context, embodiments of the supercharged internal combustion engine in which the leading edge is wedge-shaped are advantageous.

A wedge-shaped leading edge makes it easier for the charge air flow to enter between two adjacent guide elements without the flow becoming turbulent. Rather, the charge air flow is guided by the wedge-shaped entry edges in a funnel-like manner between the guide elements, with the wing-like guide elements ensuring that the charge air flow is guided along the guide elements.

Embodiments of the supercharged internal combustion engine are advantageous in which two adjacent strip-like guide elements form a channel that tapers towards the compressor impeller.

If the duct formed by two adjacent guide elements tapers like a nozzle in the direction of flow, the charge air flow guided between two adjacent guide elements is accelerated as it flows through the duct, as a result of which the relative speed between the impeller and the outer charge air flow entering the impeller, in particular the relative speed between the impeller and the condensate droplets hitting the impeller can be reduced.

Embodiments of the supercharged internal combustion engine in which the inner sleeve is cylindrical are advantageous.

The cylindrical design of the inner sleeve gives the guide device a certain symmetry, which facilitates installation of the guide device in the intake system or the compressor inlet area, i.e. assembly.

Embodiments of the supercharged internal combustion engine are advantageous in which the inner sleeve runs and is designed coaxially to the shaft of the compressor.

The at least one compressor has an inlet area which runs and is formed coaxially to the shaft of the compressor. In this respect, an internal sleeve designed coaxially to the shaft of the compressor forms the streamlined extension of the coaxially designed inlet area.

This simplifies the adjustment or introduction of the charge air flow guided between the guide elements to the peripheral speed of the impeller or the impeller blades.

Embodiments of the supercharged internal combustion engine are advantageous in which the inner sleeve has first holes.

The first holes provide fluid communication of the outer charge air flow with the inner charge air flow, i.e. the interior of the sleeve. The holes can be circular, elliptical or angular, in particular polygonal, but can also have any other shape.

In this context, embodiments of the supercharged internal combustion engine are advantageous in which the inner sleeve has first holes between the strip-like guide elements.

As a result of the acceleration of the outer charge air flow guided between two adjacent guide elements, the static pressure outside the sleeve drops. The resulting pressure difference between the interior of the sleeve and the outer channel, as the driving pressure difference, ensures a charge air flow via the first holes from the interior of the sleeve into the outer channel. This creates additional turbulence in the outer charge air flow, which leads to or contributes to the atomization of the condensate or the comminution of the condensate droplets.

Also advantageous are embodiments of the supercharged internal combustion engine in which at least one strip-like guide element has at least one second hole.

In this context, embodiments of the supercharged internal combustion engine are advantageous in which each strip-like guide element has a plurality of second holes.

The second holes ensure a fluidic connection of the charge air flows on both sides th of a strip-like guiding element. The holes can be circular, elliptical or angular, in particular polygonal, but can also have any other shape.

As a result of this fluidic connection and the deflection of the charge air streams between the guide elements, additional turbulences are generated in the outer charge air flow, which lead to or contribute to the atomization of the condensate or the comminution of the condensate droplets. This further counteracts the risk of damage to the blades.

Embodiments of the supercharged internal combustion engine are advantageous in which the strip-like guide elements are encased by an external sleeve.

Embodiments of the supercharged internal combustion engine are advantageous in which the at least one compressor is a mechanical supercharger or an electrically driven supercharger.

Embodiments of the supercharged internal combustion engine are advantageous in which the at least one compressor belongs to an exhaust gas turbocharger that includes a turbine arranged in the exhaust gas discharge system and the compressor, with the compressor and the turbine being arranged on the same shaft.

Embodiments of the supercharged internal combustion engine are advantageous in which the exhaust gas recirculation comprises a shut-off element which is used to adjust the recirculated exhaust gas quantity. The exhaust gas that is returned to the inlet side and preferably cooled is mixed with fresh air upstream of the compressor. The mixture of fresh air and recirculated exhaust gas generated in this way forms the charge air, which is fed to the compressor and compressed.

Embodiments of the supercharged internal combustion engine are advantageous in which a ventilation line is provided which opens into the intake system upstream of the at least one compressor.

• 1a schematisch ein Fragment des Ansaugsystems einer ersten Ausführungsform der Brennkraftmaschine mitsamt Leiteinrichtung, teilweise geschnitten und mit Blick in Richtung der Welle des Verdichters,
• 1b das in 1a dargestellte Fragment des Ansaugsystems im Querschnitt entlang der in 1a kenntlich gemachten Linie A - A, und
• 1c das in 1a dargestellte Fragment des Ansaugsystems im Querschnitt entlang der in 1a kenntlich gemachten Linie B - B.

The invention is based on an embodiment and according to the 1a , 1b and 1c described in more detail. This shows:

• 1a schematically a fragment of the intake system of a first embodiment of the internal combustion engine together with the guide device, partially sectioned and looking in the direction of the compressor shaft,
• 1b this in 1a shown fragment of the intake system in cross section along the in 1a marked line A - A, and
• 1c this in 1a shown fragment of the intake system in cross section along the in 1a marked line B - B.

the 1a shows schematically a fragment of the intake system 1 of a first embodiment of the internal combustion engine together with the guide device 4, partially in section and with a view in the direction of the shaft 2a of the compressor 2 1a a plan view of the compressor impeller 2b in the direction of the charge air flow.

the 1b and 1c show that in 1a shown fragment of the intake system 1 in cross section along the in 1a marked lines A - A and B - B.

The intake system 1 serves to supply charge air to the cylinders and the compressor 2 to charge the cylinders and thus the internal combustion engine. The compressor 2 comprises an impeller 2b mounted in a compressor housing 2c on a rotatable shaft 2a and equipped with rotor blades. The inlet area 3 of the compressor 2 is designed coaxially to the shaft 2a of the compressor 2, so that the section of the intake system 1 upstream of the compressor 2 has no changes in direction and the flow of charge air to the compressor 2 would take place axially without further measures.

The internal combustion engine is equipped with exhaust gas recirculation, which includes a recirculation line that branches off from the exhaust gas discharge system and opens into intake system 1 upstream of compressor 2 or compressor impeller 2b, forming a node (not shown).

The intake system 1 of the internal combustion engine is equipped with a guide device 4, which is arranged upstream of the compressor impeller 2b and which also extends between the compressor impeller 2b and the node, as also in FIG 1b shown.

The guide device 4 comprises an inner cylindrical sleeve 4a and several strip-like guide elements 4b, which encircle the inner sleeve 4a at least in regions in a spiral shape, as shown in FIG 1c shown.

Inside the sleeve 4a, the majority of the charge air is guided centrally in the intake system 1. This inner charge air flow 6b flows against the compressor impeller 2b essentially axially.

Another part of the charge air flows around the inner sleeve 4a on the outside and forms an outer charge air flow 6a, which flows through an outer annular channel formed between the inner sleeve 4a and the inner wall 1a of the intake system 1.

The outer charge air flow 6a regularly has a high proportion of condensate or many condensate droplets, as also in 1b shown.

In the outer channel between the inner sleeve 4a and the inner wall 1a of the intake system 1, several guide elements 4b of the guide device 4 are arranged, which spirally surround the inner sleeve 4a on the outside in regions and have a wedge-shaped leading edge 4b'.

When flowing through the strip-like guide elements 4b, the outer charge air flow 6a together with the condensate or the condensate droplets is forced to have a speed component in the direction of the peripheral speed of the rotating compressor impeller 2b. The peripheral speed of the impeller 2b is in 1c indicated by a straight arrow.

The relative speed between the impeller 2b and the outer charge air flow 6a entering the impeller 2b, in particular the relative speed in the circumferential direction of the impeller 2b between the impeller 2b and the condensate droplets impinging on the impeller 2b, is reduced.

The speed vector of the charge air flow 6a relative to the compressor wheel 2b is composed of the speed vector of the charge air flow 6a in the intake system 1 and the vector of the peripheral speed of the rotating compressor wheel 2b.

The inner sleeve 4a has first holes 5a between the strip-like guide elements 4b, which create a fluidic connection between the outer channel and the interior of the sleeve 4a. As a result of the acceleration of the outer charge air flow 6a between the guide elements 4b, the static pressure in the outer channel drops, which is why charge air flows from the inside of the sleeve 4a into the outer channel via the first holes 5a. The turbulence thus generated in the outer charge air flow 6a contributes to the atomization of the condensate and the comminution of the condensate droplets.

The guide elements 4b themselves have second holes 5b, which also ensure a fluidic connection between the charge air flows on both sides of the strip-like guide elements 4b. As a result of the deflection of the charge air flow between the guide elements 4b, additional turbulences are generated in the outer charge air flow 6a by means of the second holes 5b.

Reference List

1

intake system

1a

inner wall of the intake system

2

compressor

2a

shaft of the compressor

2 B

Compressor impeller, compressor impeller

2c

compressor housing

3

inlet area of the compressor

4

control device

4a

inner sleeve

4b

strip-like guiding element

4b'

Leading edge of a guide element

5a

hole, first hole

5b

hole, second hole

6a

outer charge air flow

6b

internal charge air flow

Claims (16)

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 the intake system (1) for compressing a charge air flow, which has at least one compressor in a compressor housing (2c). an impeller (2b) mounted on a rotatable shaft (2a) and equipped with rotor blades and having an inlet area (3) which runs coaxially to the shaft (2a) of the compressor (2) and is formed, - an exhaust gas recirculation system comprising a recirculation line which runs from exhaust gas discharge system and opens into the intake system (1) upstream of the at least one impeller (2b) forming a node, and - a guide device (4) which is arranged upstream of the at least one compressor impeller (2b) in the intake system (1) and which at least also between the at least one compressor impeller (2b) and the node, characterized in that s - the guiding device (4), an inner sleeve (4a) and several strip-like guiding elements (4b) comprises, wherein the strip-like guide elements (4b) the inner sleeve (4a) encircle the outside at least partially spirally. Supercharged internal combustion engine claim 1 , characterized in that the strip-like guide elements (4b) spiral around the inner sleeve (4a) in such a way that the charge air flow guided using the guide elements (4b) has a speed component in the direction of the peripheral speed of the rotating compressor impeller. Supercharged internal combustion engine claim 1 or 2 , characterized in that at least one strip-like guide element (4b) is attached to an inner wall (1a) of the intake system (1). Supercharged internal combustion engine according to one of the preceding claims, characterized in that at least one strip-like guide element (4b) is fastened to the inner sleeve (4a). Supercharged internal combustion engine claim 4 , characterized in that at least one strip-like guide element (4b) and the inner sleeve (4a) are formed in one piece in such a way that the at least one strip-like guide element (4b) and the inner sleeve (4a) form a monolithic component. Supercharged internal combustion engine according to one of the preceding claims, characterized in that at least one strip-like guide element (4b) has a wing-shaped cross-section at least in regions. Supercharged internal combustion engine according to one of the preceding claims, characterized in that each strip-like guide element (4b) has an entry edge (4b') facing the flow of charge air. Supercharged internal combustion engine claim 7 , characterized in that the leading edge (4b ') is wedge-shaped. Supercharged internal combustion engine according to one of the preceding claims, characterized in that two adjacent strip-like guide elements (4b) form a channel which tapers towards the compressor impeller (2b). Supercharged internal combustion engine according to one of the preceding claims, characterized in that the inner sleeve (4a) is cylindrical. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the inner sleeve (4a) runs and is designed coaxially to the shaft (2a) of the compressor (2). Supercharged internal combustion engine according to one of the preceding claims, characterized in that the inner sleeve (4a) has first holes (5a). Supercharged internal combustion engine claim 12 , characterized in that the inner sleeve (4a) has first holes (5a) between the strip-like guide elements (4b). Supercharged internal combustion engine according to one of the preceding claims, characterized in that at least one strip-like guide element (4b) has at least one second hole (5b). Supercharged internal combustion engine Claim 14 , characterized in that each strip-like guide element (4b) has a plurality of second holes (5b). Supercharged internal combustion engine according to one of the preceding claims, characterized in that the strip-like guide elements (4b) are encased by an external sleeve.

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