Compressor housing, radial compressor with a compressor housing of this type, radial compressor arrangement, exhaust gas turbocharger and internal combustion engine

Abstract

The invention relates to a compressor housing (9) for a radial compressor (7), with a receiving chamber (17) for a compressor impeller (15), an outflow region (19) and a collecting cavity (21), wherein the compressor housing (9) has a flow connection (23) between the collecting cavity (21) and the outflow region (19), and a valve device (25) which is arranged and configured to change a flow cross section of the flow connection (23) between the collecting cavity (21) and the outflow region (19).

Description

[0001] DESCRIPTION

[0002] Compressor housing, radial compressor with such a compressor housing, radial compressor arrangement, exhaust gas turbocharger and internal combustion engine

[0003] The invention relates to a compressor housing, a radial compressor with such a compressor housing, a radial compressor arrangement with such a radial compressor, an exhaust gas turbocharger with such a radial compressor arrangement or such a radial compressor, and an internal combustion engine with such an exhaust gas turbocharger, such a radial compressor arrangement or such a radial compressor.

[0004] Radial compressors of the type discussed here typically have a diffuser in which the flow velocity of the compressed fluid is reduced in favor of a pressure buildup. If the mass flow of the fluid in the diffuser decreases, flow instabilities and / or backflows can occur because an available flow channel is not fully utilized and a pressure gradient of the fluid acts against its flow direction. In such operating situations, compressor surge of the radial compressor can occur, which in particular makes stable engine operation of an internal combustion engine equipped with the radial compressor impossible. In particular, certain operating ranges of the internal combustion engine are not viable, and it is possible that targets for the operation of the internal combustion engine cannot be achieved. In particular, compressor surge can lead to the need to reduce the power of the internal combustion engine.

[0005] It is fundamentally possible to stabilize or shift the performance map of a radial compressor through measures such as recirculating the pumped fluid. However, depending on the specific design, this can result in further disadvantages, particularly in performance map ranges where compressor surge is not a concern.

[0006] The invention is therefore based on the object of creating a compressor housing, a radial compressor with such a compressor housing, a radial compressor arrangement with such a radial compressor, an exhaust gas turbocharger with such a radial compressor arrangement or such a radial compressor, and an internal combustion engine with such an exhaust gas turbocharger, such a radial compressor arrangement or such a radial compressor, wherein the disadvantages mentioned are at least reduced, preferably do not occur.

[0007] The object is achieved by providing the present technical teaching, in particular the teaching of the independent claims as well as the preferred embodiments disclosed in the dependent claims and the description.

[0008] The object is achieved in particular by providing a compressor housing for a radial compressor, which has a receiving space for a compressor wheel, a discharge flow area and a collecting cavity, wherein the compressor housing also has a fluidic connection - in particular a fluidic return connection - between the collecting cavity and the discharge flow area and a valve device. The valve device is arranged and configured to determine a flow cross-section of the fluidic connection between the collecting cavity and the

[0009] To change the outflow area. By means of the fluidic connection between the collecting cavity and the outflow area, a characteristic map of a radial compressor having the compressor housing can advantageously be expanded, shifted and / or stabilized, in particular to prevent compressor surge. By means of the valve device, it is advantageously possible to make the corresponding change to the characteristic map only when and / or only to the extent that compressor surge is actually to be feared. If, on the other hand, the radial compressor is operated in characteristic map areas in which no compressor surge occurs, the flow cross-section of the fluidic connection can be reduced - in particular to zero - so that at least substantially, preferably completely, the characteristic map is retained which would exist without the fluidic connection.This makes it possible to reduce or avoid disadvantages that would otherwise be associated with changing the engine map, particularly efficiency losses, particularly in those operating ranges. Recirculation generally leads to efficiency losses and a reduction in the pressure ratio across the radial compressor. However, in engine map ranges where compressor surge is a threat, this is accepted in favor of stable engine operation without any loss of performance. The option of switching off recirculation advantageously avoids efficiency losses of the radial compressor in engine map ranges where there is no threat of compressor surge and thus the efficiency losses are not offset by other advantages, particularly at rated engine power. Recirculation in the downstream flow range advantageously leads to a further improvement in the surge limit.Thus, the combination of the variable, particularly switchable and switchable recirculation on the one hand and the recirculation in the outflow area downstream of the compressor wheel on the other hand leads to a significantly improved characteristic map and to stable, performance-optimized engine operation.

[0010] The fluidic connection between the collecting cavity and the outflow region is designed, in particular, such that, during operation of the radial compressor having the compressor housing, a gas flow can flow from the collecting cavity into the outflow region—in particular opposite to a main flow direction in the radial compressor. In particular, the fluidic connection is a second fluidic connection formed between the collecting cavity and the outflow region in addition to a first fluidic connection formed along the main flow direction between the outflow region and the collecting cavity. In particular, the second fluidic connection is therefore also referred to as a fluidic return connection.

[0011] In particular, the outflow area is arranged downstream of the compressor wheel.

[0012] In particular, the outflow region has at least one stationary guide vane, in particular a plurality of stationary guide vanes.

[0013] In particular, the collecting cavity is arranged downstream of the compressor wheel, in particular downstream of the discharge area. Alternatively or additionally, the collecting cavity is part of a diffuser section of the compressor housing.

[0014] In one embodiment, the compressor housing has the diffuser section, which in particular encompasses the outflow area and the collecting cavity or is formed by the outflow area and the collecting cavity. The valve device is in particular configured to change the flow cross-section of the fluidic connection between the collecting cavity and the outflow area in a parameter-dependent manner, i.e., depending on at least one parameter.

[0015] In particular, the valve device is designed to selectively interrupt or release the fluidic connection - in particular depending on the parameters.

[0016] In particular, the valve device is designed to completely release or completely block the fluidic connection - in particular depending on the parameters - or to release the fluidic connection - in particular depending on the parameters - gradually, in particular in discrete steps or continuously.

[0017] According to a further development of the invention, the compressor housing has a first housing wall that at least partially delimits the receiving space, the discharge area, and the collecting cavity. At least one discharge bore opening into the collecting cavity and at least one inflow bore opening into the discharge area are formed in the first housing wall. The collecting cavity is fluidically connected to the discharge area via the at least one discharge bore and the at least one inflow bore. This represents a design of the compressor housing that is both compact and simple and cost-effective to manufacture.

[0018] In one embodiment, the first housing wall can be formed in multiple parts. In another embodiment, the first housing wall is formed in one piece, in particular from a single material. In particular, in one embodiment, the first housing wall can be formed as a cast part or as part of a cast part.

[0019] In particular, the fluidic connection between the collecting cavity and the outflow area is established or formed via the at least one outflow bore and the at least one inflow bore. In particular, the at least one outflow bore is fluidically connected to the at least one inflow bore in such a way that the gas flow during operation of the radial compressor having the compressor housing can flow from the collecting cavity via the at least one outflow bore and the at least one inflow bore into the outflow area. According to a further development of the invention, it is provided that the compressor housing has an annular space into which the at least one outflow bore and the at least one inflow bore open, so that the collecting cavity is connected to the

[0020] The downstream flow area is fluidically connected via the annular space. This represents a particularly compact design for the compressor housing.

[0021] In particular, the annular space concentrically surrounds the receiving space along a circumferential direction. In one embodiment, the annular space is a protective space or containment space intended to stabilize the compressor housing or to protect, in particular, bystanders or neighboring equipment in the event of destruction of the compressor wheel, in particular due to bursting.

[0022] In the context of the present technical teaching, an axial direction is understood in particular to mean a direction that extends along an imaginary axis of rotation of the compressor wheel when the latter is arranged as intended in the compressor housing, in particular in the receiving space. The circumferential direction encompasses the axial direction concentrically. A radial direction is perpendicular to the axial direction.

[0023] According to a further development of the invention, the compressor housing has a second housing wall that connects a collecting cavity wall section of the first housing wall with an outflow area wall section of the first housing wall. This represents a particularly simple design for mechanically stabilizing the compressor housing and forming the annular space.

[0024] In particular, the annular space is delimited on the one hand by the first housing wall and on the other hand by the second housing wall - in particular completely.

[0025] In one embodiment, the second housing wall can be formed in multiple parts. In another embodiment, the second housing wall is formed in one piece, in particular from the same material. In one embodiment, the second housing wall can be formed in one piece, in particular from the same material, as the first housing wall. In one embodiment, the compressor housing, together with the first housing wall and the second housing wall, can be formed as a cast part.

[0026] According to a further development of the invention, the valve device is configured to selectively open and close at least one bore selected from the outflow bore and the inflow bore. This represents a particularly simple and compact way of changing the flow cross-section of the fluidic connection.

[0027] According to a further development of the invention, the first housing wall has a plurality of inlet bores opening into the discharge area. In particular, this allows a portion of the fluid from the collecting cavity to be very efficiently recirculated into the discharge area in order to modify the compressor characteristic map.

[0028] In particular, the inlet holes are arranged at equal angular intervals along a circumference, i.e., particularly along the circumferential direction. This allows for a particularly uniform and efficient recirculation of a portion of the compressed fluid.

[0029] Alternatively or additionally, it is possible for the first housing wall to have a plurality of outlet bores leading into the collecting chamber—and in particular into the annular chamber. In particular, the outlet bores are distributed at equal angular intervals along the circumference, i.e., in particular along the circumferential direction.

[0030] In particular, the valve device is designed to selectively open or close all outflow holes and / or all inflow holes - in particular simultaneously.

[0031] According to a further development of the invention, the at least one inlet bore is nozzle-shaped. This allows a directed and thus particularly efficient inflow of the recirculated fluid into the outflow area.

[0032] In one embodiment, the at least one nozzle-shaped inlet bore has an insert, in particular a nozzle insert, integrated into or inserted into the first housing wall, or is designed as such an insert. In another embodiment, the at least one nozzle-shaped inlet bore is shaped or formed by the first housing wall.

[0033] The object is also achieved by providing a radial compressor having a compressor housing according to the invention or a compressor housing according to one or more of the previously described embodiments. In connection with the radial compressor, the advantages already explained above in connection with the compressor housing are particularly evident.

[0034] According to a further development of the invention, it is provided that a compressor wheel is arranged in the receiving space.

[0035] In particular, the compressor wheel has at least one rotating guide vane, in particular a plurality of rotating guide vanes.

[0036] The object is also achieved by providing a radial compressor arrangement comprising a radial compressor according to the invention or a radial compressor according to one or more of the previously described embodiments, as well as a control device that is operatively connected to the valve device and configured to control the valve device. In connection with the radial compressor arrangement, the advantages that were previously explained in connection with the compressor housing or the radial compressor are particularly advantageous.

[0037] In particular, the control device is configured to control the valve device in a parameter-dependent manner, i.e., dependent on at least one parameter. In this way, a very flexible modification of the characteristic map of the radial compressor can be carried out, wherein the characteristic map can remain unchanged, in particular, when the radial compressor is operated in a characteristic map range in which compressor surge is not to be feared.

[0038] According to a further development of the invention, the control device is configured to control the valve device to an open position when an operating state of the radial compressor lies in a predetermined characteristic map region adjacent to a surge limit. Particularly in such a characteristic map region, there is a risk of compressor surge occurring, which is why it is advantageous if the valve device is controlled to the open position to release the fluidic connection.

[0039] In one embodiment, the control device is configured to control the valve device depending on the at least one parameter such that the fluidic connection is optionally completely released or completely blocked, or gradually released, in particular in discrete steps or continuously.

[0040] The at least one parameter is selected, in particular, from a group consisting of: a pressure downstream of the radial compressor, a pressure loss across the radial compressor, a speed of the compressor wheel, and a mass flow across the radial compressor. These parameters, in particular, define a characteristic map of the radial compressor and are therefore suitable for evaluating the risk of compressor surge and, if necessary, initiating appropriate countermeasures.

[0041] In one embodiment, the control device is configured to enable or disable the fluidic connection depending on a comparison of the at least one parameter with an associated limit value.

[0042] In particular, the control device is operatively connected to at least one parameter sensor, which is arranged and configured to detect the at least one parameter. The at least one parameter sensor is in particular selected from a group consisting of: a pressure sensor, a tachometer, and a mass flow sensor.

[0043] Alternatively or additionally, it is possible for the control device to be configured to calculate the at least one parameter or to determine it by simulation, or to receive the at least one parameter from another computing device, for example the control unit of an internal combustion engine.

[0044] The object is also achieved by providing an exhaust gas turbocharger having a radial compressor according to the invention or a radial compressor according to one or more of the previously described embodiments, or having a radial compressor arrangement according to the invention or a radial compressor arrangement according to one or more of the previously described embodiments. In connection with the exhaust gas turbocharger, the advantages that have already been explained in connection with the radial compressor arrangement, the radial compressor, or the compressor housing are particularly advantageous.

[0045] The object is finally also achieved by creating an internal combustion engine which has a radial compressor according to the invention or a radial compressor according to one or more of the previously described embodiments, or which has a radial compressor arrangement according to the invention or a radial compressor arrangement according to one or more of the previously described embodiments, or which has an exhaust gas turbocharger according to the invention or an exhaust gas turbocharger according to one or more of the previously described embodiments. In connection with the internal combustion engine, in particular those advantages arise which have already been explained in connection with the compressor housing, the radial compressor, the radial compressor arrangement or the exhaust gas turbocharger.

[0046] The invention is explained in more detail below with reference to the drawing. The single figure shows an embodiment of an internal combustion engine with an embodiment of an exhaust gas turbocharger, an embodiment of a radial compressor arrangement, an embodiment of a radial compressor, and an embodiment of a compressor housing.

[0047] The sole figure shows an embodiment of an internal combustion engine 1 with an embodiment of an exhaust gas turbocharger 3, an embodiment of a radial compressor arrangement 5, an embodiment of a radial compressor 7 and an embodiment of a compressor housing 9.

[0048] The exhaust gas turbocharger 3 has in particular a turbine 13 arranged in an exhaust gas path 11 of the internal combustion engine 1, which is drive-connected to a compressor wheel 15 of the radial compressor 7.

[0049] The compressor housing 9 has a receiving space 17 for the compressor wheel 15, a

[0050] Outflow area 19 and a collecting cavity 21. In addition, the compressor housing 9 has a fluidic connection 23 between the collecting cavity 21 and the outflow area 19 and a valve device 25, wherein the valve device 25 is arranged and configured to change a flow cross-section of the fluidic connection 23 between the collecting cavity 21 and the outflow area 19, in particular depending on parameters, in particular to selectively interrupt or release the fluidic connection 23.

[0051] In particular, at least one stationary guide vane 26 is arranged in the outflow region 19. The compressor wheel 15 has, in particular, at least one rotating guide vane 28.

[0052] The radial compressor arrangement 5 has a control device 27, which is operatively connected to the valve device 25 and is configured to control the valve device 25, in particular as a function of at least one parameter. The at least one parameter is preferably selected from a group consisting of: a pressure downstream of the radial compressor 7, a pressure loss across the radial compressor 7, a rotational speed of the compressor wheel 15, and a mass flow across the radial compressor 7.

[0053] The control device 27 is in particular designed to control the valve device 25 into an open position when an operating state of the radial compressor 7 lies in a predetermined characteristic map range arranged adjacent to a surge limit.

[0054] In particular, the compressor housing 9 has a first housing wall 29 which at least partially delimits the receiving space 17, the outflow area 19 and the collecting cavity 21. In the first housing wall 29, at least one outflow bore 31 opening into the collecting cavity 21 and at least one in the

[0055] An inflow bore 33 is formed which opens into the outflow area 19, the collecting cavity 21 being fluidically connected to the outflow area 19 via the at least one outflow bore 31 and the at least one inflow bore 33.

[0056] In particular, the compressor housing 9 has an annular space 35 into which, on the one hand, the at least one outflow bore 31 and, on the other hand, the at least one inflow bore 33 open, so that the collecting cavity 21 is fluidically connected to the outflow area 19 via the annular space 35.

[0057] In the embodiment illustrated here, the compressor housing 9 has a second housing wall 37, which connects a collecting cavity wall section 39 of the first housing wall 29 with an outflow area wall section 41 of the first housing wall 29. In particular, the annular space 35 is delimited on the one hand by the first housing wall 29 and on the other hand by the second housing wall 37.

[0058] The valve device 25 is in particular designed to selectively open and close at least one bore selected from the outflow bore 31 and the inflow bore 33, here in particular the outflow bore 31.

[0059] In particular, the first housing wall 29 has a plurality of inflow bores 33 opening into the outflow area 19, which are preferably distributed at equal angular intervals along a circumference around a rotational axis A of the compressor wheel 15. Alternatively or additionally, the first housing wall 29 has a plurality of outflow bores 31 opening into the collecting chamber 21, which are preferably distributed at equal angular intervals along the circumference around the rotational axis A of the compressor wheel 15.

[0060] Preferably, the at least one inflow bore 33 is nozzle-shaped, wherein it is formed in particular integrally with the first housing wall 29, in particular formed by it, or in particular inserted into it as a nozzle insert.

Claims

CLAIMS 1. Compressor housing (9) for a radial compressor (7), with a receiving space (17) for a compressor wheel (15), a discharge flow area (19) and a collecting cavity (21), wherein the compressor housing (9) has a fluidic connection (23) between the collecting cavity (21) and the discharge flow area (19) and a valve device (25) which is arranged and set up to control a flow cross-section of the fluidic connection (23) between the collecting cavity (21) and the From flow area (19) to change.

2. Compressor housing (9) according to claim 1, wherein the compressor housing (9) has a first housing wall (29) which at least partially delimits the receiving space (17), the outflow region (19) and the collecting cavity (21), wherein at least one outflow bore (31) opening into the collecting cavity (21) and at least one inflow bore (33) opening into the outflow region (19) are formed in the first housing wall (29), wherein the collecting cavity (21) is fluidically connected to the outflow region (19) via the at least one outflow bore (31) and the at least one inflow bore (33).

3. Compressor housing (9) according to claim 2, wherein the compressor housing (9) has an annular space (35) into which the at least one outflow bore (31) and the at least one inflow bore (33) open, so that the collecting cavity (21) is connected to the From the flow area (19) is fluidically connected via the annular space (35).

4. Compressor housing (9) according to one of claims 2 or 3, wherein the compressor housing (9) has a second housing wall (37) which connects a collecting cavity wall section (39) of the first housing wall (29) to an outflow region wall section (41) of the first housing wall (29), wherein in particular the annular space (35) is delimited by the first housing wall (29) and by the second housing wall (37).

5. Compressor housing (9) according to one of claims 2 to 4, wherein the valve device (25) is arranged to selectively open and close at least one bore (31, 33) selected from the outflow bore (31) and the inflow bore (33).

6. Compressor housing (9) according to one of claims 2 to 5, wherein the first housing wall (29) has a plurality of inflow bores (33) opening into the outflow area (19), which are arranged distributed in particular along a circumference at equal angular intervals.

7. Compressor housing (9) according to one of claims 2 to 6, wherein the at least one inflow bore (33) is nozzle-shaped.

8. Radial compressor (7), with a compressor housing (9) according to one of claims 1 to 7.

9. Radial compressor (7) according to claim 8, wherein a compressor wheel (15), in particular with at least one rotating guide vane (28), is arranged in the receiving space (17).

10. Radial compressor arrangement (5), with a radial compressor (7) according to one of claims 8 or 9, and with a control device (27) which is operatively connected to the valve device (25) and is designed to control the valve device (25), in particular in a parameter-dependent manner.

11. Radial compressor arrangement (5) according to claim 10, wherein the control device (27) is arranged to control the valve device (25) into an open position when an operating state of the radial compressor (7) lies in a predetermined characteristic map range arranged adjacent to a surge limit.

12. Exhaust gas turbocharger (3) with a radial compressor (7) according to one of claims 8 or 9, or with a radial compressor arrangement (5) according to one of claims 10 or 11.

13. Internal combustion engine (1) with a radial compressor (7) according to one of claims 8 or 9, or with a radial compressor arrangement (5) according to one of claims 10 or 11, or with an exhaust gas turbocharger (3) according to claim 12.

Images