Compressor with trimmer and drainage pipe and internal combustion engine with such a compressor

Abstract

Compressor (22) with a housing (50) forming a flow chamber (52) within which a compressor impeller (30) is rotatably mounted, and an inlet channel (56) connecting a compressor inlet (58) to the flow chamber (52), wherein a trimming device (44) is arranged in the inlet channel (56) by which a marginal section of the inlet cross-section of the compressor impeller (30) can be variably covered, characterized by a drainage line (48) which extends into a section of the inlet channel (56) in which the trimming device (44) is arranged and which terminates in the inlet channel (56).

Description

[0001] The invention relates to a compressor and an internal combustion engine with such a compressor.

[0002] In the compressor of an internal combustion engine, the fresh gas supplied to the engine via a fresh gas stream is compressed. The increase in fresh gas pressure depends on the rotational speed of the compressor impeller and the mass flow rate of the fresh gas passing over it. Towards the so-called surge line of the compressor map, the flow towards the leading edges of the impeller blades becomes increasingly pressure-side due to the decreasing flow velocity relative to the circumferential speed; that is, the incidence of the flow increases steadily. Above an operating-point-dependent threshold for the incidence, the so-called surge line, the flow separates at the leading edges, and the flow within the compressor becomes unstable. In the surge line region, a backflow region of low-impulse fluid forms on the inlet-side contour of the compressor housing.This so-called backflow bubble leads to a decrease in compressor efficiency due to swirl and mixing losses. However, in the area of ​​the impeller hub contour, a high-impulse and low-loss core flow also runs through the compressor near the surge line, determining the mass flow rate and pressure build-up.

[0003] A trimmer, such as that known from DE 10 2010 026 176 A1, EP 3 018 355 A1, DE 10 2015 209 704 A1, or WO 2014 / 131790 A1, serves to shift the surge line of a compressor characteristic curve towards relatively low mass flow rates at high pressure ratios. Simultaneously, a trimmer can increase the compressor efficiency in the surge line region. For this purpose, a trimmer comprises a device by which the inflow cross-section through which the compressor impeller is exposed to the flow can be changed. Through the nozzle effect thus achieved by the trimmer, the gas flow can be more strongly focused on the hub-adjacent inlet cross-section of the compressor impeller with increasing control intervention (reduction of the inflow cross-section). This results in less gas flowing into the low-impulse and lossy area of ​​the backflow bubble, and the core flow in the hub area is accelerated and thus further stabilized.

[0004] The acceleration of the gas flow near the hub of the compressor impeller also results in a suction-side shift in the flow direction towards the impeller, which can contribute to further stabilization of the gas flow. This stabilization of the core flow leads to the desired shift of the surge line of the compressor characteristic curve to lower mass flow rates. If control intervention is not desired (trim control fully open), the entire cross-section of the fresh gas stream upstream of the compressor impeller is opened as much as possible, so that no additional friction or throttling losses occur in the resulting flow direction towards the impeller. Therefore, the compressor efficiency and the width of the compressor characteristic curve are not negatively affected to a significant degree by a trim control in the direction of the surge line.

[0005] Modern internal combustion engines frequently employ low-pressure exhaust gas recirculation (LP-EGR) to meet legally mandated emission limits. In this system, exhaust gas extracted downstream of an exhaust turbine in a turbocharger is routed through a recirculation line upstream of the turbocharger compressor into the fresh air intake of the engine. The compressor then draws this exhaust gas in along with air to create the fresh air supply. Ideally, the recirculated exhaust gas should be introduced as close as possible to the compressor to minimize unwanted condensation in the fresh air. A control valve is often integrated into the LP-EGR line to regulate the LP-EGR rate.

[0006] However, even when the recirculated exhaust gas is introduced directly upstream of the compressor impeller, there is a risk that a significant amount of condensate will be introduced into the fresh air stream of an internal combustion engine via the recirculated exhaust gas, potentially entering the compressor impeller. This is particularly true if the recirculated exhaust gas or an exhaust gas cooler integrated into the exhaust gas recirculation line has a relatively low temperature, which promotes condensation. If condensate, or larger droplets of condensate, enter the compressor impeller, there is a risk of damage to the impeller, which increases with the speed of the impeller. Consequently, it is currently standard practice to operate the internal combustion engine with no or relatively low recirculation, i.e.,The system should be operated below a defined low-pressure exhaust gas recirculation rate, optimized for minimizing pollutant emissions, when operating conditions for the internal combustion engine allow or promote condensate ingress into the compressor. It is obvious that this results in relatively poor emissions performance from the internal combustion engine.

[0007] In the compressors with trimmer known from DE 10 2015 209 704 A1 and WO 2014 / 131 790 A1, an exhaust gas recirculation line for low-pressure exhaust gas recirculation is also provided, which opens into an inlet channel of the respective compressor in the area of ​​the associated trimmer. The opening is positioned such that, with active exhaust gas recirculation and a relatively far closed position of the trimmer, which focuses the flow towards the respective compressor impeller on a hub-adjacent section of the inlet cross-section, the recirculated exhaust gas is guided into the edge section of the inlet cross-section covered by the respective trimmer.

[0008] DE 10 2010 027 26 A1 discloses a turbocharged internal combustion engine with an exhaust gas recirculation line and an eddy flow generator, by means of which solids are separated from the mixture of fresh gas and exhaust gas before the mixture enters the compressor. The solids are then discharged via an outlet line.

[0009] DE 10 2015 016 030 A1 describes a turbocharged internal combustion engine in which a condensate drain line leads from a high-pressure section of the compressor and downstream of a charge air cooler into the charge air path.

[0010] DE 20 2015 100 195 U1 discloses a turbocharged internal combustion engine with an exhaust gas recirculation line, in which condensation in the area of ​​the outlet of the exhaust gas recirculation line and thus also in front of the compressor is to be avoided by returning a portion of the fresh gas already compressed by the compressor to the compressor via a recirculation line as required.

[0011] US Patent 2016 / 0186701A1 describes a compressor in which condensate accumulating upstream of the compressor impeller is first collected in a recess and, as needed, selectively accelerated toward a section of the compressor impeller near the hub by opening a valve located in a return line that allows already compressed fresh gas to be returned to the low-pressure side and which opens into the recess. This is intended to prevent the condensate from splashing onto the outer sections of the compressor impeller and thus avoid damaging it. Condensate introduced into or accumulating in a fresh gas line upstream of a compressor can not only damage the compressor impeller but also negatively affect the functionality of a trimmer associated with the compressor.This is particularly true if the corresponding internal combustion engine is not operated at ambient temperatures below freezing, causing condensate that has accumulated in the area of ​​the trim control to freeze. This can prevent or at least hinder the adjustability of the trim control when the internal combustion engine is restarted.

[0012] The invention was based on the objective of avoiding such an impairment of the functionality of a trimmer of an internal combustion engine.

[0013] This problem is solved by an embodiment of a compressor according to claim 1 or of an internal combustion engine according to claim 6. Advantageous further developments of the compressor and the internal combustion engine according to the invention are the subject of further claims and / or will become apparent from the following description of the invention.

[0014] The invention is based on the idea of ​​preventing impairment of the functionality of a trimmer by condensate coming into contact with it, which can freeze when a compressor or internal combustion engine comprising the trimmer is not in operation at ambient temperatures below freezing, by removing this condensate.

[0015] Accordingly, according to the invention, a compressor is provided with a housing that forms a flow chamber within which a compressor impeller is rotatably mounted, and an inlet channel that connects a compressor inlet to the flow chamber. A trimmer is arranged in the inlet channel, particularly in a recess formed by the housing, by which a peripheral section of the inlet cross-section of the compressor impeller can be variably covered. Furthermore, a drainage line is provided that extends from a section of the inlet channel in which the trimmer is arranged and terminates in the inlet channel. The drainage line can preferably be designed as a fully enclosed drainage channel, at least in one section.

[0016] A corresponding internal combustion engine according to the invention comprises at least one combustion engine (in particular a diesel engine or a gasoline engine or a combination thereof, i.e., a combustion engine with homogeneous compression ignition), a fresh gas stream, and an exhaust stream, wherein a compressor is integrated into the fresh gas stream and wherein a trimmer is associated with the compressor, by which a peripheral section of the inlet cross-section of a compressor impeller can be variably covered. Furthermore, a drainage line is provided, which branches off in a section of the fresh gas stream in which the trimmer is arranged and terminates in the fresh gas stream. In this case as well, the trimmer can in particular be arranged in a recess in a wall of the fresh gas stream.

[0017] According to the invention, the "entry plane" of the compressor impeller is understood to be the plane closest to the trimmer, oriented perpendicular to the axis of rotation of the compressor impeller, and defined by the impeller blades of the compressor impeller by having at least a point-like section of one, several, or all of the leading edges of these impeller blades arranged within this plane. The "entry cross-section" of the compressor impeller is then the opening cross-section of the flow space located in this plane.

[0018] The trimmer of a compressor or internal combustion engine according to the invention can, in principle, be designed in any way, for example according to one of the embodiments disclosed in DE 10 2010 026 176 A1, EP 3 018 355 A1, DE 10 2015 209 704 A1 or WO 2014 / 131790 A1.

[0019] According to a preferred embodiment of a compressor according to the invention, the housing may be provided with at least one connecting channel opening into the inlet channel, which is / are provided for the connection of an exhaust gas recirculation line and / or an engine housing vent line and / or a tank vent line. It is further preferred that a section of the drainage line opens into the connecting channel. This indirect return of condensate via the connecting channel to the inlet channel allows for a particularly advantageous distribution of the condensate into the fresh gas flowing in the inlet channel towards the compressor impeller. The connecting channel forms a section of the drainage line.

[0020] Accordingly, an internal combustion engine according to the invention can preferably comprise an exhaust gas recirculation line that connects the exhaust gas stream (in a section preferably located downstream of an exhaust gas turbine (if present)) with the fresh gas stream, and / or an engine casing ventilation line that connects an internal volume, in particular a crankcase space, of the internal combustion engine with the fresh gas stream, and / or a purge gas line that connects a fuel vapor filter of a fuel tank system of the internal combustion engine with the fresh gas stream, wherein a section of the drainage line opens into the exhaust gas recirculation line or the engine casing ventilation line or the purge gas line.The outlet opening of the exhaust gas recirculation line and / or the engine casing ventilation line and / or the purge gas line can be formed by the compressor housing according to the design of a compressor according to the invention, which has at least one corresponding connection channel. However, it is also possible to arrange it at any other location on the wall of the fresh gas stream.

[0021] According to a preferred embodiment of such a compressor or internal combustion engine according to the invention, it can then be further provided that the connecting channel upstream of the trim control opens into the inlet channel, or that the exhaust gas recirculation line and / or the engine housing ventilation line and / or the purge gas line open / open into the fresh gas stream upstream of the trim control.This preferred embodiment of a compressor or internal combustion engine according to the invention is based on the understanding that the risk of damage to a compressor impeller by condensate, which is introduced in particular via recirculated exhaust gas upstream of the compressor impeller into the fresh gas stream (regardless of whether this condensate is discharged via the drain line or already carried along by the recirculated exhaust gas before the outlet of the drain line), increases not only with the rotational speed of the compressor impeller, but also depends on the area of ​​the compressor impeller on which the liquid droplets of condensate impact. Specifically, the outer or edge section of the compressor impeller is particularly vulnerable because it experiences the highest circumferential speeds during rotation.Furthermore, since an advantageous use of a trimmer is usually such that it focuses the flow of fresh gas onto a hub-adjacent section of the compressor impeller under the same operating conditions of the internal combustion engine where exhaust gas recirculation is also typically provided, an outlet, in particular of the exhaust gas recirculation line or the associated connecting channel, upstream of the trimmer consequently makes it possible to use the trimmer to shield the edge section of the compressor impeller from the condensate that was introduced into the fresh gas stream with the recirculated exhaust gas, and thereby protect the most vulnerable area of ​​the compressor impeller from damage by the condensate.

[0022] According to a preferred embodiment of a compressor according to the invention, the drainage line, or at least a section of it (drainage channel) that may be fully enclosed, runs (completely) within the housing, is integrated into the housing, or is limited by the housing. A corresponding embodiment of an internal combustion engine according to the invention is characterized in that the drainage line, or at least a section of the drainage line, runs within a wall of the fresh gas stream, is integrated into the housing, or is limited by the housing. Such an embodiment of a compressor or an internal combustion engine according to the invention can be further described in alternative embodiments in which the drainage line is partially enclosed by an external, i.e.,A pipe, particularly a hose, running outside the wall of the fresh gas line offers the advantage of relatively small installation space requirements and relatively simple assembly. On the other hand, designs with a partially external (drainage) pipe can be advantageous in terms of manufacturing costs.

[0023] Advantageous condensate removal can preferably be achieved by having the drainage line, or at least a section thereof, branch off at the lowest point of the inlet channel or fresh gas line receiving it, with respect to a defined operating position of the compressor or internal combustion engine, and / or by opening into the connecting channel, exhaust gas recirculation line, engine casing ventilation line, or purge gas line at a point that is lower than the point where the drainage line branches off from the inlet channel and / or has a continuously descending or sloped course.

[0024] The term "defined operating position" refers to the position or orientation of the compressor or internal combustion engine that it permanently or primarily exhibits during its intended use, particularly in a motor vehicle. When used in a motor vehicle, this is the position or orientation that the compressor or internal combustion engine exhibits when the vehicle is horizontally oriented.

[0025] The compressor of an internal combustion engine according to the invention can, in particular, be part of an exhaust gas turbocharger, which further comprises an exhaust gas turbine integrated into the exhaust stream, wherein the preferably provided exhaust gas recirculation line can then branch off from the exhaust stream, in particular downstream of the exhaust gas turbine. The compressor is then driven by means of the exhaust gas turbine using the exhaust gas enthalpy. Alternatively or additionally, the compressor can also be designed to be driven in another way, for example by the internal combustion engine, i.e., mechanically, or by means of an electric motor.

[0026] An internal combustion engine according to the invention can, in particular, be part of a motor vehicle. The internal combustion engine of the internal combustion engine can, in particular, be provided for the direct or indirect provision of propulsion power to the motor vehicle.

[0027] Such a motor vehicle may in particular be a wheel-based and not rail-bound motor vehicle (preferably a car or a truck).

[0028] The indefinite articles (“a”, “an”, “one”, and “ones”), particularly in the patent claims and in the description generally explaining the patent claims, are to be understood as such and not as numerals. Accordingly, components specified by these articles are to be understood as existing at least once and potentially existing multiple times.

[0029] The present invention is explained in more detail below with reference to embodiments illustrated in the drawings. The drawings show, in simplified form: Fig. 1: an internal combustion engine according to the invention; Fig. 2: a longitudinal section through a compressor for an internal combustion engine according to the Fig. 1 according to a first embodiment with an associated trim control in the widest possible open position Fig. 3: a longitudinal section through a compressor for an internal combustion engine according to the Fig. 1 according to a second embodiment; and Fig. 4: a longitudinal section through a compressor for an internal combustion engine according to the Fig. 1 according to a third design form.

[0030] The Fig. Figure 1 shows a schematic representation of an internal combustion engine according to the invention, comprising an internal combustion engine 10 with a plurality of cylinders 12. The cylinders 12, together with pistons moving up and down within them and a cylinder head (not shown), define combustion chambers in which fresh gas is combusted together with fuel. The fuel is injected directly into the combustion chambers by means of injectors 16, controlled by a control device 14 (engine control unit). The combustion of the fuel-fresh gas mixture results in cyclical up-and-down movements of the pistons, which are transmitted in a known manner via connecting rods (not shown) to a crankshaft (also not shown), thereby causing the crankshaft to rotate.The fresh gas is supplied to the combustion engine 10 via a fresh gas line and is drawn in from the environment through an intake opening 18, cleaned in an air filter 20, and then fed into a compressor 22, which is part of an exhaust gas turbocharger. The fresh gas is compressed by the compressor 22, then cooled in a charge air cooler 24, and then fed to the combustion chambers. The compressor 22 is driven by an exhaust gas turbine 26 of the exhaust gas turbocharger, which is integrated into an exhaust gas line of the combustion engine. Exhaust gas, which is produced during the combustion of the fuel-fresh gas mixture in the combustion chambers of the combustion engine 10, is discharged from the combustion engine 10 via the exhaust gas line and flows through the exhaust gas turbine 26. This results, in a known manner, in the rotating drive of a turbine impeller (not shown), which is connected to a compressor impeller 30 (see figure) via a shaft 28. Fig. 2, Fig. 3 to Fig. 4) of the compressor 22. The rotating drive of the turbine impeller is thus transferred to the compressor impeller 30.

[0031] To achieve the most optimal use of the exhaust gas enthalpy for generating compression power by means of the exhaust gas turbocharger when operating the internal combustion engine 10 with varying loads and speeds, the exhaust gas turbine 26 of the exhaust gas turbocharger can optionally (especially in a configuration of the internal combustion engine 10 as a diesel engine) have a device for variable turbine flow (VTG) 32, which can be controlled by the control device 14. This device can, in a known manner, comprise a plurality of guide vanes (not shown) arranged in an inlet channel of the exhaust gas turbine 26, which are individually rotatable, and which are collectively adjustable by means of an adjustment device (not shown).Depending on the rotational positions of the guide vanes, these narrow the free flow cross-section in the inlet channel of the exhaust gas turbine 26 to a greater or lesser degree and also influence the section of the primary flow to the turbine impeller and the direction of this flow.

[0032] Downstream of the compressor 22, a control flap 34, also controllable by means of the control device 14, is integrated into the charge air path, i.e., into the section of the fresh gas stream located between the compressor 22 and the internal combustion engine 10. In a configuration of the internal combustion engine 10 as a gasoline engine, this control flap 34 can be a throttle valve (with known functionality). In a configuration of the internal combustion engine 10 as a diesel engine, the primary function of the control flap 34 can be to close the charge air path briefly after the diesel engine has stopped operating, thereby preventing the flow of already compressed fresh gas into the combustion chambers of the diesel engine.

[0033] The internal combustion engine further comprises an exhaust gas recirculation line 36 for implementing (low-pressure) exhaust gas recirculation, in which exhaust gas from a section of the exhaust stream located downstream of the exhaust turbine 26 and, in particular, also downstream of an exhaust aftertreatment device 38, for example, a particulate filter, can be diverted and introduced into a section of the fresh gas stream upstream of the compressor impeller 30. The quantity of exhaust gas to be recirculated via the exhaust gas recirculation line 36 can be controlled or regulated by means of a control valve 40, which can be actuated by the control device 14. Furthermore, an exhaust gas cooler 42 is integrated into the exhaust gas recirculation line 36 for cooling the exhaust gas passing through it.

[0034] A trimmer 44 is assigned to the compressor 22, which can influence the flow of fresh gas to the compressor impeller 30. The trimmer 44, or an associated actuator (not shown), can be controlled by the control device 14. The exhaust gas recirculation line 36 opens upstream, or on the side of the trimmer 44 facing away from the compressor impeller 30, into the fresh gas stream.

[0035] The Fig. 2, Fig. 3 to Fig. Figure 4 shows possible embodiments of the compressors 22 according to the invention in longitudinal section. These compressors 22 can, for example, be used for an internal combustion engine according to the Fig. 1 is provided, so that the trimmer 44, a connection channel 46 for the exhaust gas recirculation line 36 and a drainage line 48 are then part of the compressor 22. This is in the Fig. 1 indicated by a dashed frame.

[0036] The compressor 22 according to the Fig. 2 comprises a housing 50, which can be a partial housing of a complete housing of an exhaust gas turbocharger. The housing 50 of the compressor 22 forms a flow chamber 52, within which the compressor impeller 30 is rotatably mounted. On the inlet side, the flow chamber 52 has an inlet cross-section located in an inlet plane 54. Fresh gas can be supplied from a compressor inlet 58 to the compressor impeller 30 via an inlet channel 56, which is also formed by the housing 50 of the compressor 22. On the outlet side, the flow chamber 52 is bounded by an "outlet plane" that surrounds the exit edges of impeller blades 60 of the compressor impeller 30. A diffuser chamber 62, also surrounding the exit edges of the impeller blades 60, closes there, and adjoining this, what is described in the Fig. 2 (and also in the Fig. 3 and Fig. 4) (not shown) a compressor volute. A compressor outlet (also not shown) extends from the compressor volute.

[0037] Within the inlet channel 56, the associated trimmer 44 is arranged at the shortest possible distance to the inlet cross-section of the compressor impeller 30. The trimmer 44 comprises an iris diaphragm 66 with a design also known from camera lenses. In the closed position, the trimmer 44 largely prevents the flow of air to the compressor impeller 30 in an annular region at the edge of the inlet cross-section and focuses the fresh gas flow onto a section of the compressor impeller 30 near the hub. In the open position, according to the Fig. 2 (and according to the Fig. 3 and Fig. 4) In contrast, the fresh gas can flow into the compressor impeller via the entire inlet cross-section. The aperture elements forming the iris diaphragm 66, which are each pivotably mounted within the housing 50 about an axis for opening or closing the iris diaphragm 66, are arranged completely in an annular recess 64 of the housing 50 in the open position.

[0038] The housing 50 of the compressor 22 forms a connection channel 46 in a section that limits the inlet channel 56 upstream or on the side of the trimmer 44 facing away from the compressor impeller 30. This connection channel is for connection to an exhaust gas recirculation line 36 of an internal combustion engine, for example, according to the Fig. 1 is planned.

[0039] Exhaust gas flowing into the inlet channel 56 via such an exhaust gas recirculation line 36 and the connecting channel 46 can comprise a relevant quantity of still gaseous or already condensed liquids (i.e., media that are liquid at least at room temperature). The still gaseous liquids of the exhaust gas condense relatively quickly upon entering the inlet channel 56 as a result of mixing there with the typically much cooler air, which together with the recirculated exhaust gas forms the fresh gas subsequently to be compressed by the compressor 22. If the operation of an internal combustion engine according to the invention, and thus also of a compressor 22 according to the invention, is carried out in accordance with the Fig. 2. Once the cycle is complete, condensate from the fresh gas still present in the inlet channel can accumulate in the recess 64. If this condensate, which consists largely of water, cools down to below freezing due to a sufficiently low ambient temperature, it freezes. After the combustion engine and thus the compressor 22 restart, this can at least temporarily prevent or impede the adjustability of the trim control 44 and thus its functionality. To avoid this problem, the housing 50 of the compressor 22 is fitted with a [missing information - likely a specific component or device] according to the [missing information - likely a specific component or device]. Fig. 2. A section of drainage line 48 is integrated, which, with respect to a defined operating position of the compressor 22, branches off at the lowest point of the recess 64 accommodating the trimmer 44 or the iris diaphragm 66 and is guided via a continuously descending, straight course to the connecting channel 46, into which it consequently empties at a point that is lower than the point at which the drainage line 48 branches off from the inlet channel 56 or from the recess 64. Condensate, which accumulates in the recess 64, particularly as a result of the cessation of operation of the internal combustion engine and thus of the compressor 22, can be discharged via the section of drainage line 48 into the connecting channel 46 and, if applicable, into the exhaust gas recirculation line 36 connected thereto.When operations are subsequently resumed, the condensate that has accumulated in the connecting channel 46 or the exhaust gas recirculation line 36 can then be reintroduced with exhaust gas into the inlet channel 56, where it may evaporate.

[0040] The compressor 22 according to the Fig. 3 differs from the one according to the Fig. 2 essentially only in that the drainage line 48 is largely formed by an external (hose) line 68. The external line 68 has a curved, continuously descending course.

[0041] In the case of compressor 22 according to the Fig. 4 The drainage line 48, which runs completely inside the housing 50, flows directly into the inlet channel 56 and not indirectly via the connecting channel 46 there for the exhaust gas recirculation line 36.

[0042] Regarding the compressors according to the Fig. 2, Fig. 3 to Fig.In section 4, the drainage line 48 is designed along its entire length as a fully enclosed drainage channel, which branches off from the inlet channel 56 or the recess 64 at the point where, in the defined operating position of the compressor 22, a gravity-induced accumulation of condensate is to be expected. This is a preferred embodiment according to the invention. However, it is also possible, in principle, to arrange the outlet opening of such a fully enclosed drainage channel at a distance from such a point and, in particular, also at a distance from the trimmer, provided, for example, that a corresponding shape of the housing wall bounding the inlet channel ensures that condensate accumulating at the aforementioned point can flow away to such an outlet opening of the drainage channel.A corresponding drainage section of the wall then forms, together with the drainage channel, a drainage line of a corresponding compressor according to the invention. In principle, the drainage line of a compressor or internal combustion engine according to the invention can also consist entirely of such a drainage section, particularly in the form of an open channel, and consequently without a fully enclosed drainage channel. REFERENCE MARK LIST 10 Internal combustion engine 12 cylinders 14 Control device 16 injectors 18 Intake nozzle 20 air filters 22 compressors 24 Intercoolers 26 Exhaust turbine 28 wave 30 compressor impeller 32 Device for variable turbine flow 34 Control valve 36 Exhaust gas recirculation line 38 Exhaust aftertreatment device 40 Control valve 42 Exhaust gas coolers 44 trimmers 46 connection channel 48 Drainage pipe 50 Compressor housing 52 Flow chamber 54 Inlet level of the compressor impeller 56 Inlet channel 58 Compressor inlet 60 wheel blade 62 Diffuser space 64 Recess of the housing 66 Iris diaphragm 68 external (hose) line

Claims

[1] Compressor (22) with a housing (50) forming a flow chamber (52) within which a compressor impeller (30) is rotatably mounted, and an inlet channel (56) connecting a compressor inlet (58) to the flow chamber (52), wherein a trimming device (44) is arranged in the inlet channel (56) by which a marginal section of the inlet cross-section of the compressor impeller (30) can be variably covered, characterized by a drainage line (48) which extends into a section of the inlet channel (56) in which the trimper (44) is located and which terminates in the inlet channel (56). [2] Compressor (22) according to claim 1, characterized by , that the housing (50) forms a connecting channel (46) opening into the inlet channel (56) for an exhaust gas recirculation line (36) or an engine housing vent line or a tank vent line, wherein a section of the drainage line (48) opens into the connecting channel (46). [3] Compressor (22) according to claim 2, characterized by , that the connecting channel (46) upstream of the trim control (44) leads into the inlet channel (56). [4] Compressor (22) according to any one of the preceding claims, characterized by , that a section of the drainage pipe (48) runs inside the housing (50). [5] Compressor (22) according to any one of the preceding claims, characterized by , that the drainage pipe (48) or at least a section thereof with respect to a defined operating position of the compressor (22) - at the lowest point of the receiving section of the inlet channel (56) and / or - ends at a point in the inlet channel (56) or opens into the connecting channel (46) that is lower than the point where it branches off from the inlet channel (56) and / or - exhibits a steadily decreasing trend. [6] Internal combustion engine comprising an internal combustion engine (10), a fresh gas stream and an exhaust gas stream, wherein a compressor (22) is integrated into the fresh gas stream and wherein a trim control (44) is associated with the compressor (22), by which a marginal section of the inlet cross-section of a compressor impeller (30) of the compressor (22) can be variably covered, characterized by a drainage line (48) which branches off in a section of the fresh gas line in which the trimming device (44) is located and which terminates in the fresh gas line. [7] Internal combustion engine according to claim 6, characterized by , that - an exhaust gas recirculation line (36) connects the exhaust gas stream with the fresh gas stream, and / or - an engine casing ventilation line connects an internal volume of the internal combustion engine (10) with the fresh gas stream and / or - a purge gas line connects a fuel vapor filter of a fuel tank system of the internal combustion engine to the fresh gas line, wherein a section of the drainage line (48) leads into the exhaust gas recirculation line (36) or into the engine casing ventilation line or into the purge gas line. [8] Internal combustion engine according to claim 7, characterized by , that the exhaust gas recirculation line (36) and / or the engine casing ventilation line and / or the purge gas line upstream of the trim control (44) leads into the fresh gas line. [9] Internal combustion engine according to any one of claims 6 to 8, characterized by , that at least one section of the drainage pipe (48) runs within a wall of the fresh gas line. [10] Internal combustion engine according to any one of claims 6 to 9, characterized by , that the drainage pipe (48) or at least a section thereof with respect to a defined operating position of the internal combustion engine - at the lowest point of the receiving section of the fresh gas stream and / or - ends at a point in the intake port (56) or opens into the exhaust gas recirculation line (36) or into the crankcase ventilation line or into the purge gas line, which is located lower than the point where it branches off from the intake port (56) and / or - exhibits a steadily decreasing trend.

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