Compressor housing for a compressor, compressor, turbomachine comprising a compressor and engine comprising a turbocharger

Abstract

The utility model relates to a compressor housing for a compressor, a compressor, a turbomachine comprising the compressor and an engine comprising a turbocharger. The compressor for the turbomachine is provided with MWE slots comprising upstream slot (s) and downstream slot (s). The upstream slot (s) open onto the shroud surface at a first axial position, and the downstream slot (s) open onto the shroud surface at a second axial position further from the inlet than the first axial position. The passage of gas through the upstream slot (s) is constantly open. The passage of gas through the downstream slots is controlled by a valve located on the gas flow path comprising the downstream slots. If a potential surge condition is determined to exist, the valve is closed, and if a potential choke condition is determined to exist, the valve is opened. This means that the upstream slots can be designed to improve gas flow in surge conditions without having to take into account the downstream slot (s), but the downstream slots can be used to increase the efficiency of the compressor in choke conditions.

Description

Technical Field

[0001] This invention relates to a compressor housing for a compressor, a compressor, a turbomachinery including a compressor, and an engine including a turbocharger, and particularly to a turbomachinery having a compressor including an impeller element. The turbomachinery can be a turbocharger, an electric turbocharger, or an electric turbocharger / electric compressor, in which the compressor is connected to the turbine via a shaft; an electric turbocharger includes an electric motor that can remove / add power to the shaft between the compressor and the turbine; in an electric turbocharger / electric compressor, the compressor is powered by the electric motor. This invention also relates to an impeller element for use in turbomachinery. Background Technology

[0002] Turbomachinery is a machine that transfers energy between a rotor and a fluid. For example, a turbomachinery can transfer energy from a fluid to a rotor, or vice versa. Two examples of turbomachinery are a power turbine and a compressor. A power turbine uses the rotational energy of a fluid-driven rotor to do useful work, such as generating electricity; a compressor uses the rotational energy of a rotor to compress a fluid.

[0003] A turbocharger is a well-known turbine machine used to supply air to the inlet of an internal combustion engine at a pressure higher than atmospheric pressure (boost pressure). A conventional turbocharger mainly consists of an exhaust-driven turbine rotor mounted on a rotatable shaft within a turbine housing, connected downstream of the engine outlet manifold. The rotation of the turbine rotor causes an impeller element (here, "impeller") to rotate, which is a compressor rotor mounted on the other end of the shaft within a compressor housing. The impeller delivers compressed air to the engine inlet manifold. Typically, the turbocharger shaft is supported by journal bearings and thrust bearings located within a central bearing housing connecting the turbine housing and the compressor housing, and includes a suitable lubrication system.

[0004] Figure 1 A schematic cross-section through a known turbocharger is shown. The turbocharger includes a turbine 1 connected to a compressor 2 via a central bearing housing 3. The turbine 1 includes a turbine runner 4 for rotation within a turbine housing 5. Similarly, the compressor 2 includes a compressor runner 6 rotatable within a compressor housing 7. The compressor housing 7 defines a "runner chamber" in which the compressor runner 6 is located and rotatable. The turbine runner 4 and the compressor runner 6 are mounted on opposite ends of a common turbocharger drive shaft 8 that extends through the central bearing housing 3.

[0005] The turbine housing 5 has at least one exhaust inlet volute 9 (located annularly around the turbine runner 4) Figure 1 The image shows two volutes and an axial exhaust outlet 10. The compressor housing 7 has an axial intake passage (compressor inlet chamber) 11 and a volute 12 arranged annularly around the impeller chamber. The volute 12 is in airflow communication with the compressor outlet 13.

[0006] Bearing housing 3 defines bearing chamber 22 through which turbocharger shaft 8 passes. Shaft 8 is rotatably supported by bearing assembly comprising two journal bearings 14 and 15 respectively housed toward the turbine end and compressor end of bearing housing 3. Oil is supplied from the internal combustion engine's oil system to the bearing assembly via oil inlet 18 and to bearings 14 and 15 via oil passage 19. The oil supplied to bearings 14 and 15 can be used for both lubrication and heat removal from the bearings.

[0007] In operation, exhaust gas travels from exhaust inlet 9 to exhaust outlet 10, while turbine rotor 4 rotates about axis 25. Exhaust gas is supplied to exhaust inlet 9 from the exhaust manifold (also referred to as outlet manifold) of the engine (not shown) to which the turbocharger is attached. Turbine rotor 4 then rotates compressor rotor 6, thereby drawing in intake air through inlet chamber 11 and delivering pressurized air via volute 12 and then via outlet 13 to the engine's inlet manifold.

[0008] The impeller chamber is defined between the shroud portion 17 of the compressor housing 7 and the hub portion 50 of the bearing housing 3. Note that the compressor housing can be formed as a one-piece (i.e., monolithic) unit including the shroud portion 17, but alternatively, the compressor housing can include multiple interconnected components. The shroud portion 17 has an inwardly facing shroud surface 21, which is circularly symmetrical about the axis of rotation 25. The shroud surface 21 is spaced from the axis of rotation 25, the spacing being in the downstream axial direction (in... Figure 1 The direction from left to right (i.e., from the entrance chamber 11 toward the compressor rotor 6) does not decrease.

[0009] The compressor impeller 6 includes a central portion (“hub”) 20 positioned on a rotation axis 25 and having a surface facing a shroud surface 21 that is generally rotationally symmetrical about the rotation axis 25, and whose diameter increases toward the turbine 1 in the downstream axial direction. The compressor impeller 6 also includes a plurality of blades 23 (or “blades”) positioned on the hub 20. The blades 23 are circumferentially spaced about the rotation axis 25 and project radially outward from the central portion 20 of the compressor impeller 6 toward their ends, which are nearly in contact with the shroud surface 21. The blades 23 are substantially layered (i.e., each blade is a curved blade), but are bent into a three-dimensional shape. Each blade has a leading edge (i.e., in the upstream axial direction... Figure 1 The farthest edge in the axial direction (from the center to the left).

[0010] In some compressor impellers, all blades 23 have the same shape and are circumferentially spaced around a rotation axis 25, and all blades 23 are aligned in the axial direction (that is, the blades 23 are at the same distance along the rotation axis 25). The set of blades 23 may have a rotational symmetry of n times about the rotation axis 25, where n is the number of blades 23.

[0011] However, in other compressor impellers, the axial blade position of the leading edge of blade 23 varies from one blade to another. Specifically, blade 23 may include a "main blade" with its leading edge at a first axial blade position and one or more sets of "splitter blades." Each set of splitter blades consists of one or more blades 23 with their leading edges located at the corresponding axial blade position (i.e., the leading edges of one or more splitter blades in a given set are located at the corresponding axial blade position), positioned in the downstream axial direction relative to the leading edge of the main blade. For example, a corresponding splitter blade may exist for each set in the angular clearance between each pair of main blades. The compressor impeller as a whole may have a rotational symmetry of n times about the axis of rotation 25, where n is the number of main blades and there are n blades in each set of splitter blades. The inclusion of splitter blades provides improved operating characteristics, particularly for surge, boost pressure, and efficiency.

[0012] It is known to provide an axially extending map width enhancement (MWE) groove 24 and one or more MWE slots 26. This can be a single annular MWE slot 26 surrounding an axis. The MWE groove 24 is a conduit for gas. The MWE groove 24 extends radially outward from at least a portion of the shroud surface 21 (i.e., further away from the axis 25 than that at least portion of the shroud surface 21). The MWE groove 24 extends from or near the inlet chamber 11 (as shown) to the MWE slot 26, which provides a passage between the MWE groove 24 and the shroud surface 21, displaced in the downstream axial direction from the leading edge of the blade 23 (in the presence of a main blade and a splitter blade, displaced in the downstream axial direction from the leading edge of the main blade).

[0013] Figure 2 An alternative form of the compressor housing 75 is shown. The compressor housing 75 is compared with... Figure 1 Components with the same meaning as those in the compressor housing 7 are given the same reference numerals. Figure 2In this configuration, the compressor impeller, specifically the impeller chamber located therein, is designated 16. The impeller chamber is radially surrounded by a shroud surface 21. An MWE recess 24 is defined in the gap between an inner skirt wall 27 and an outer skirt wall 29. Both the inner and outer skirt walls are axially projecting and are generally cylindrical walls included within the shroud portion 17. The outer skirt wall 29 is further away from the axis 25 than the inner skirt wall 27. A portion of the radially inward-facing surface of the inner skirt wall 27 may define a portion of the shroud surface 21.

[0014] Figure 2 The inlet chamber 11 in the compressor housing is provided with an insertion element 30 having an outer perimeter supported by an outer skirt wall 29, and the insertion element 30 includes a wall 31 converging in the downstream axial direction. An MWE groove communicates with the inlet chamber 11 in an annular gap between the truncated conical wall 31 and the inner skirt wall 27. The wall 31 may be truncated conical, truncated spherical, or toroidal, and may be an "insertion element" formed separately from and subsequently attached to the housing 75.

[0015] As described above, the MWE slot 26 can be annular (i.e., extending around the entire axis 25). A strut / web can be provided (e.g., in...). Figure 1 (At an angle not shown in the diagram), to support the inner skirt wall 27. For example, a strut / web may be provided between the inner skirt wall 27 and the outer skirt wall 29, such as adjacent to or upstream of the MWE slot 26, and may be formed by casting. Alternatively, the inner skirt wall 27 may be formed as part of an element that also includes the wall 31, and the strut may connect the inner skirt wall 27 to the wall 31.

[0016] Figure 2 The illustration shows the function of the MWE groove 25 (in both forms of the compressor housing) in use (i.e., when the compressor rotor 6 (not shown) is present). Figure 2 The arrows in the diagram indicate airflow under surge conditions (operating points where the pressure on the pressure side of the blades is high, requiring high throttling). Specifically, some airflow near the shroud surface 21 is drawn into the MWE slot 26, travels through the MWE recess 24, and is injected into the inlet chamber 11 in front of the compressor rotor 6. In this way, flow conditions in the blade tip region of the inlet inducer can be manipulated. This results in reduced clogging and aerodynamic stabilization of the compressor for low mass flow rates. The compressor's pressure ratio increases, leading to higher efficiency. The MWE slot 26 is also beneficial under choke conditions, as under these conditions, gas can flow in the opposite direction through the MWE slot 26 to be injected into the rotor chamber 16, for example, between the blades.

[0017] Figure 1 and Figure 2 The difference between compressor housings 7 and 75 is that... Figure 2 The MWE groove 24 of the compressor housing 75 is longer. This means that during surge conditions, the gas traveling through the MWE slot 26 and the MWE groove 24 enters the inlet chamber 11 from the compressor impeller further, resulting in a more uniform impeller inlet flow.

[0018] Figure 3A It schematically shows, as Figure 1 and Figure 2 The diagram shows the efficiency levels of a compressor of a certain size at various values ​​of mass flow rate (mass of gas passing through the impeller per second) and pressure ratio (the ratio of pressure at the outlet to the inlet of the compressor impeller 6). Line 33 is the "surge line," to the left of which the flow becomes unstable. Line 32 is the "choke line," to the right of which efficiency drops below a certain limit (e.g., 58%). Ellipses 33, 34, and 35 are lines representing the corresponding efficiency values ​​in the flow diagram; for example, the efficiency is the same at all points on line 35 and is higher than the efficiency at all points on line 33. Line 37 represents a possible trajectory in the flow diagram during engine operation. It is undesirable for line 33 to be close to surge line 31, as this would lead to a risk of flow instability. The effect of the MWE groove 25 is to widen the gap between surge line 31 and choke line 32 to reduce this risk.

[0019] Figure 3B The diagram schematically illustrates the effect of reducing the dimensions of the compressor stages (i.e., compressor housings 7, 75 and compressor impeller 6) without altering the dimensions of the turbine impeller 4. This can be achieved by reducing the diameter of the upstream portion (“inlet guide”) of the compressor impeller 6 while maintaining the diameter of the downstream portion, thereby reducing compressor trim (i.e., the ratio of the diameter of the inlet guide to the diameter of the downstream portion). Surge lines 31, choke lines 32, and lines 33, 34, 34 are shifted to the left. This has the beneficial effect of trajectory 37 being closer to the high-efficiency ellipse 35. Furthermore, the “surge margin” (the separation of surge line 31 from trajectory 37) is extended. However, the leftward shift (i.e., towards lower mass flow) has the disadvantage that trajectory 37 extends beyond choke line 32 with a high mass flow. That is, the trajectory includes the end region marked 36 beyond choke line 32, resulting in lower engine efficiency. In other words, there is a trade-off between performance improvement under surge conditions and performance degradation under choke conditions. Utility Model Content

[0020] In general, this invention proposes that a compressor for turbomachinery has MWE slots at two axially spaced locations. Therefore, the MWE slots include "(one or more) upstream slots" and "(one or more) downstream slots", wherein the upstream slots open to the shroud surface at a first axial location, and the downstream slots open to the shroud surface at one or more second axial locations further from the inlet than the first axial location.

[0021] The passage of gas through one or more downstream slots can be controlled by a valve located in the airflow path including one or more downstream slots. This valve allows for fine-grained control of the flow. Specifically, the valve can be controlled based on input data including sensor measurements and / or information about the current operating conditions of a turbomachinery including a compressor (e.g., an engine including a compressor, such as in a turbocharger). Control of the valve involves opening / closing it based on determining whether the input data meets one or more criteria. For example, if a first criterion (e.g., a criterion indicating a potential surge condition) is met, the valve can be closed; and if a second criterion (e.g., a criterion indicating a surge condition) is met, the valve can be opened. The first and second criteria can be mutually exclusive, and optionally, one criterion can be true while the other is false. For example, the first and second criteria can be based on measured pressures, such as pressures measured in the downstream MWE slot.

[0022] The existence of a valve controlled to close under surge conditions means that one or more upstream slots can be designed to improve gas flow under surge conditions without considering downstream slots, but the downstream slots can be used to improve compressor efficiency under blockage conditions. Specifically, it has been found that opening the valve to activate the downstream slots can shift the blockage line in the direction of higher quality flow.

[0023] Note that the compressor can be configured such that, under blocked conditions (i.e., when the valve is controlled to be open), gas can flow into the impeller chamber through both the upstream and downstream slots. The airflow path including the upstream slot(s) can be passive, meaning there is no mechanism or means to alter (block or widen) the gas passage through the upstream slot(s). Therefore, the upstream slot(s) are in constant fluid communication with the compressor inlet (i.e., the gas passage through the upstream slot(s) is constantly open). For example, the airflow path can be defined (only) by the housing. Providing a passive airflow path through the upstream slot(s) simplifies the control mechanism or means, and the upstream and downstream slots can cooperate to inject gas at the perimeter of the compressor impeller when the control valve of the downstream slot(s) is open.

[0024] The housing can be a single element, or if the housing comprises multiple elements, these elements can be fixed to each other. In particular, as in the known systems described above, the gas passage can be at least partially defined by an MWE recess that communicates with one or more upstream MWE slots, surrounds the axis of rotation, and typically leads to a chamber defining the inlet of the compressor.

[0025] A valve for controlling the gas passage through one or more downstream slots can be configured to control gas entry from the upstream side into a gas chamber communicating with one or more downstream slots. The downstream slots can be configured as multiple slots circumferentially spaced at different angular positions around the axis of rotation, or as a single downstream slot extending around the entire axis or substantially the entire axis. In both cases, the compressor housing preferably includes only one valve (i.e., a single valve) that controls the airflow through the downstream slots. This makes a simple control system possible because only one valve needs to be controlled. In one case, the downstream slots can be configured as gaps between struts extending across an annular space in the housing that extends around the compressor's axis of rotation.

[0026] The valve can communicate with both the gas chamber and the conduit, providing a controlled airflow from the conduit to the gas chamber. The conduit extends from the compressor's gas inlet to the valve. Thus, a "downstream" airflow path is provided along one or more radial downstream slots, starting at (or near) the compressor inlet, traveling through the conduit, then through the valve, then via the valve into the gas chamber, and from the gas chamber to the downstream slots(s). Note that the conduit can lead to the compressor's inlet chamber, communicating with a single inlet gas of the compressor, such that the conduit receives gas already entering the compressor's inlet chamber (i.e., a portion of the gas traveling from the compressor inlet to the impeller); alternatively, the conduit can define a separate gas inlet, which is considered here as part of the compressor's inlet.

[0027] At least a portion of the downstream airflow passage can also be used for one or more other purposes. For example, under certain conditions, the airflow from the compressor outlet to the engine inlet manifold may be partially or completely blocked. This can happen, for example, in a spark-ignition engine when the throttle valve of the engine inlet manifold is closed. If the high-pressure gas produced by the compressor cannot travel from the compressor outlet to the engine inlet manifold (or at least not to the desired extent), this can lead to a phenomenon known as "dead heading," in which the high-pressure flow is forced back through the impeller (compressor impeller) toward the compressor inlet, resulting in a large "surge" event that can cause compressor instability or even damage to the compressor. Furthermore, since in embodiments where the compressor is part of a turbocharger, the compressor impeller is connected to the turbocharger turbine via a shaft, the reverse airflow through the compressor impeller can have undesirable effects on the engine's exhaust system.

[0028] To mitigate this situation, in embodiments of this invention, a surge duct may optionally be provided, communicating with the compressor outlet, and under dead-head conditions, allowing high-pressure gas to travel from the compressor outlet back to a point on the downstream airflow path. The gas can then travel from that point on the downstream airflow path to the opening of the duct at the compressor inlet, i.e., under dead-head conditions, the gas travels along the duct in the opposite direction to the flow direction under blocked conditions. This use of the duct under dead-head conditions avoids the need for the surge duct itself to extend all the way to the compressor inlet, i.e., avoids the need to provide a duct that extends to the compressor inlet and is only used under dead-head conditions. Therefore, the size of the compressor can be reduced compared to a compressor with a surge duct extending to the compressor inlet.

[0029] For example, a surge duct may lead to a gas chamber. A surge valve may be configured (e.g., controlled) to selectively allow gas to travel from the surge duct into the gas chamber. The surge valve may be controlled or configured to open under dead-head conditions, for example, if the pressure downstream of the compressor is higher than a "surge" threshold (an absolute pressure threshold, or a pressure threshold compared to, for example, the pressure in the gas chamber). For example, the surge valve may be controlled based on a sensor (e.g., located downstream of the surge duct or compressor impeller) or based on the current operating state of the engine manifold (including the throttle). Alternatively, the surge valve may be designed to open without external control when the pressure in the surge duct is higher than the pressure in the gas chamber by an amount exceeding the surge threshold. In either case, if dead-head surge occurs, the valve (the valve on the downstream airflow passage) provides gas communication between the duct and the gas chamber. Specifically, if (i) the second criterion (as defined above) is met (e.g., if the risk of an existing gas blockage condition is higher than a threshold); or (ii) the third criterion indicating a dead heading condition is met (e.g., if the pressure in the surge pipe is higher than a threshold, or higher than the pressure in the pipe by an amount higher than the threshold), then the valve provides gas communication between the pipe and the gas chamber.

[0030] Alternatively, the surge duct can lead to a valve (i.e., a valve in the downstream airflow path) instead of the gas chamber. In this case, the valve can be controlled or configured to allow gas to flow from the surge duct through the valve into the duct under dead-heading conditions (e.g., if the pressure in the surge duct (e.g., as measured by a sensor located in the surge duct or downstream of the compressor) is above a threshold, or based on the current operating state of the engine manifold). Thus, the valve can function to provide gas communication between the duct and the gas chamber if a second criterion is met (e.g., the aforementioned second criterion indicating a risk of an existing gas blockage condition exceeding a threshold); or alternatively, to provide gas flow between the duct and the surge duct if a third criterion (indicating a dead-heading condition) is met. Attached Figure Description

[0031] Non-limiting embodiments of the present invention will now be described with reference to the following accompanying drawings, which are merely examples:

[0032] Figure 1 This is a cross-sectional view of a known turbocharger;

[0033] Figure 2 It is a cross-section of the compressor casing of another type of compressor;

[0034] Figure 3 is from Figure 3A and Figure 3B The diagram illustrates the components and schematically demonstrates how to modify the compressor mapping if the compressor size is reduced.

[0035] Figure 4 This is a cross-section of the compressor housing according to the first embodiment of this utility model;

[0036] Figure 5 The diagram shows... Figure 4 Airflow under surge conditions in the casing;

[0037] Figure 6 The diagram shows... Figure 4 Airflow under air-blocking conditions within the casing;

[0038] Figure 7 The illustration shows how to open the included Figure 4 The modification of the compressor mapping caused by the valves of the compressor housing;

[0039] Figure 8 This is a cross-section of the compressor housing according to the second embodiment of the present invention; and

[0040] Figure 9 This is a cross-section of the compressor housing according to the third embodiment of this utility model. Detailed Implementation

[0041] refer to Figure 4 The compressor housing 175 is shown in cross-section, and this compressor housing 175 is an embodiment of the present invention. Figure 5 and Figure 6 The diagram illustrates the operation of a compressor including a compressor housing 175. The compressor housing 175 includes elements of a known compressor housing 75, but also includes additional elements described below. The compressor's... Figure 2 The components of the known compressor housing 75 are equivalent to those indicated by the same reference numerals. It should be understood that all these components have the structure explained above.

[0042] and Figure 2 Compared to the compressor housing 75, Figure 4 The compressor housing 175 includes an additional generally cylindrical portion 101 that defines an inlet chamber 111 at the compressor inlet, the inlet chamber 111 being larger than... Figure 2 The inlet chamber 11 is larger (because it is longer in the axial direction). A conduit 103 (pipe) is formed extending from the inlet chamber 111. The conduit 103 leads into the inlet chamber 111 at an axial position along the upstream axial direction (i.e., along...). Figure 4The MWE groove 24 is shifted (upward direction) from this axial position to communicate with the inlet chamber 111. Therefore, the conduit 103 receives a portion of the gas entering the compressor's inlet chamber. (Note that in a variation, the conduit 103 may alternatively not lead to the inlet chamber 111, but may instead define its own gas inlet to the compressor; in this case, the inlet to the conduit 103 is also considered part of the inlet to the compressor.)

[0043] and Figure 1 and Figure 2 Like compressor housings 7 and 75, compressor housing 175 includes an MWE slot 26. The MWE slot 26 communicates with an MWE recess 24 defined between the inner skirt wall 27 and the outer skirt wall 29 of the housing body 17. The MWE recess 24 communicates with the inlet chamber 111. The MWE slot 26 may have a... Figure 1 and Figure 2 The same configuration is used in the compressor housing 175, where the MWE slot 26 is referred to as the "upstream slot". In another embodiment, multiple circumferentially spaced upstream MWE slots 26 may exist.

[0044] The conduit 103 leads to a gas chamber 105 surrounding an axis 25 of the compressor housing 175. In this embodiment, the gas chamber 105 completely surrounds the axis 25, but in a variation, the gas chamber 105 may only surround a portion of the axis 25, for example, a portion at an angle of 330 degrees. The gas chamber 105 is defined in the upstream axial direction by an annular end wall 107 and has an outer perimeter defined by a generally cylindrical wall 109 in the radial direction (i.e., transverse to the axis 25). The gas chamber 105 in the downstream axial direction (i.e., Figure 2 The end surface in the downward direction is provided by a portion of the compressor housing 175 that defines the volute 12.

[0045] Valve 117 is disposed in the airflow path between inlet chamber 111 and gas chamber 105, for example, at the opening in the inlet gas chamber 105 of inlet chamber 111. Valve 117 can be controlled by a mechanical or electronic control system (not shown) as described below to move between a "closed" configuration and an "open" configuration. In the "closed" configuration, valve 117 prevents gas from flowing along the airflow path between inlet chamber 111 and gas chamber 105 via conduit 103. In the "open" configuration, valve 117 allows gas to travel along this airflow path from inlet chamber 111 through conduit 103 and into gas chamber 105.

[0046] One or more "downstream slots" 126 are provided. Each downstream slot 126 is a passageway that leads at a first end into a gas chamber 105 and at a second end onto a shroud surface 21 downstream of the radially inner end of the upstream slot 26. Thus, a "downstream" airflow passage is provided to the downstream slots 126 along a path that begins at the inlet chamber 111, passes through the conduit 103, then through the valve 117, enters the gas chamber 105, and from the gas chamber 105 into the downstream slots 126.

[0047] If multiple downstream slots 126 exist, they are angularly spaced from each other about the axis of rotation 25. However, a single downstream slot 126 may also exist, and this is assumed in the following description. The downstream slot 126 may be annular (i.e., completely surrounding the axis 25, for example, having rotational symmetry about the axis 25). However, in another embodiment (e.g., the gas chamber 105 does not completely surround the axis 25 in one of the above-mentioned embodiments), the downstream MWE slot 126 may be at an angle of less than 360 degrees about the axis 25, for example, an angle of 330 degrees.

[0048] The compressor housing 175 can be considered to include an upstream portion 120 and a downstream portion 121, wherein the upstream portion 120 and the downstream portion 121 are spaced apart by a downstream MWE slot 126 surrounding axis 25. The downstream slot 126 can be defined, for example, between two truncated conical surfaces (i.e., on the upstream portion 120 and the downstream portion 121 of the compressor housing 175, respectively). The upstream portion 120 and the downstream portion 121 of the compressor housing 175 can be connected by the walls of the gas chamber 105 (e.g., end walls 107 and 109). Furthermore, a strut (not shown) connecting the upstream portion 120 and the downstream portion 121 of the compressor housing 175 can be provided.

[0049] Note that even if multiple downstream slots 126 exist, preferably only a single valve 117 exists, which is positioned to control the only airflow path from the inlet chamber 111 to the gas chamber 105. Thus, the airflow passage through all downstream slots 126 is controlled by a single (i.e., unique) valve 117, which controls the airflow entering the gas chamber 105 along the duct 103.

[0050] In contrast, the airflow passage through the MWE groove 24 and the upstream MWE slot 26 is "passive". That is, there are no controllable elements on the airflow passage to change the airflow in the airflow passage, that is, to controllably suppress the airflow in the airflow path from the shield surface 21 to the inlet chamber 111, which includes the MWE groove 24 and the upstream MWE slot 26.

[0051] Note that the downstream MWE slot 126 leads to the impeller chamber 6 at a second axial position, which is in the downstream axial direction (in Figure 4 In the middle (in the downward direction), it is spaced apart from the first axial position where the upstream MWE slot 26 enters the impeller chamber 6.

[0052] In use, the compressor impeller (not shown) is inserted into the impeller chamber 6 and is arranged to rotate about axis 25 (e.g., in the case where the compressor is part of a turbocharger, it rotates on the turbocharger shaft connected to the turbine impeller).

[0053] As mentioned above, the compressor impeller can be a impeller with main blades and splitter blades. For simplicity, it will be assumed that only a single splitter blade exists. In this case, the leading edge of each main blade (e.g., the upstream position on the main blade) can be located at... Figure 4 The location of the first axial blade is indicated by the dashed line 113. The leading edge of the splitter blade (e.g., the upstream position on the splitter blade) can be located at... Figure 4 The second axial blade position is indicated by the dashed line 115. The upstream MWE slot 26 can extend to the shroud surface 21 between the first axial blade position 113 at the leading edge of the compressor impeller's main blade and the second axial position 115 at the leading edge of the compressor impeller's splitter blade (at the first axial position). In other words, the upstream MWE slot 26 can inject or remove gas at the first axial position (in the axial direction) on the shroud surface 21, located between the leading edge of the main blade and the leading edge of the splitter blade. In contrast, the downstream MWE slot 126 can extend to the shroud surface 21 at a second axial position, which is shifted downstream from the second axial blade position 115 at the leading edge of the splitter blade (i.e., at...). Figure 2 In the downward direction, it is further than the second axial blade position 115, but it is shifted from the downstream end of the splitter blade in the upstream axial direction (i.e., in...). Figure 2 The middle is further upstream than the downstream end of the cross-flow blade.

[0054] Figure 5 The first operating mode of the compressor, including the compressor housing 175, is schematically shown. Figure 5 The compressor impeller is omitted. The first operating mode is the operating mode used under "surge conditions," which are conditions where the compressor operation approaches the surge line on the compressor map. In this case, valve 117 is in the closed configuration. Gas flows away from impeller chamber 6 through upstream MWE slot 26, enters MWE recess 24, and is introduced into inlet chamber 111, as indicated by the arrow. Figure 2As is the case in a known compressor housing 75, this causes the surge line 32 to move toward a lower mass flow rate, thereby improving stability.

[0055] Figure 6 The second operating mode of the compressor, including the compressor housing 175, is schematically shown. Figure 5 The compressor impeller is omitted. The second operating mode is the operating mode employed under the "blocking condition," which is the condition where the compressor operation approaches the blockage line on the compressor map. In this case, valve 117 is in the open configuration. Gas flows from inlet chamber 111 through MWE recess 24 and enters the impeller chamber at a first axial position through upstream MWE slot 26, as indicated by the arrow. Furthermore, as indicated by other arrows, gas flows from inlet chamber 111 along pipe 103 and enters gas chamber 105 through valve 117. From there, gas travels through downstream MWE slot 126 and enters impeller chamber 6 at a second axial position. Thus, there is an airflow through both upstream MWE slot 26 and downstream MWE slot 126. The simultaneous airflow on these two gas paths cooperates to move the blockage line on the compressor map toward a higher quality flow rate.

[0056] Specifically, and especially when the compressor has a relatively small size, the presence of airflow in the downstream MWE slot 26 (or one or more) alters the compressor mapping from... Figure 3B The following modification is shown: Figure 7 As shown. When valve 117 is opened, Figure 3B The choke line 32 is moved to a new position 135 so that the trajectory 37 does not cross the choke line 32 even at the end 36. Therefore, high efficiency is maintained even for high mass flows (e.g., the position on trajectory 37 corresponding to the highest mass flow experienced by the engine under all possible operating conditions). This means that the compressor can be made smaller relative to the turbine runner without accepting any trade-offs for surge or choke conditions. This reduces the moment of inertia of the compressor runner 6. For example, the diameter of the inlet guide vane of the compressor runner 6 can be reduced even without reducing the diameter of the downstream portion of the compressor runner 6. Reducing the moment of inertia of the compressor runner 6 improves transient response and also improves turbine efficiency due to a better blade speed ratio.

[0057] In some embodiments, valve 117 may be implemented as a lift valve. Optionally, valve 117 may be operated electronically under the control of a control system implemented in electronic equipment, such as by a microprocessor. The control system may be a control system of a larger machine including a compressor. For example, in the case where the compressor is part of a turbocharger for an internal combustion engine, the control system may operate to control other aspects of the engine's operation. For example, the control system may be the main electronic control system of a vehicle including the engine.

[0058] The control system is operable to control the movement of valve 117 between an open configuration and a closed configuration. This can be achieved based on one or more criteria that are functions of input data. The input data may include sensor data captured by one or more sensors, and / or available operational data of the control system relating to the operation of the machinery that forms part of the compressor. For example, the control system may be configured to receive sensor data indicating the compressor's outlet-inlet pressure ratio.

[0059] Alternatively or additionally, if the compressor is part of an internal combustion engine, the control system may access operating data describing the operation of the engine (e.g., engine speed and / or load), such as the operating speed of the engine cylinders in which fuel is burned when mixed with pressurized gas injected from the compressor.

[0060] The control of valve 117 by the control system can depend on the compressor-side flow and / or pressure ratio. Under normal operating conditions (i.e., Figure 7 (On the left side), the control system controls valve 117 to close. In this case, the upstream MWE slot 26 can be operated to remove gas from the compressor rotor 6, and no additional gas source is required. Conversely, in Figure 7 On the right side, when the pressure in the downstream MWE slot 126 is negative (i.e., less than the pressure at the compressor inlet), the control system opens valve 117 to provide more gas to the compressor rotor 6.

[0061] In one implementation, the control system can determine whether the input data meets a criterion indicating the presence of a blockage condition (i.e., an indication that the risk of the compressor reaching the blockage line is more concerning than the risk of the compressor reaching the surge line), that is, the control system determines whether the criterion is "true". If it is "true", the control system controls valve 117 in the open configuration; that is, if valve 117 is not already in the open configuration, the control system moves valve 117 to the open configuration. If it is not "true", the control system controls valve 117 in the closed position; that is, if valve 117 is not already in the closed configuration, the control system moves valve 117 to the closed configuration.

[0062] Note that using only one criterion carries the risk that if the engine operates near the boundary between the true and false criterion, fluctuations in engine operation may cause the true value of the criterion (i.e., whether it is true or false) to change rapidly and repeatedly between "true" and "false". This could cause the control system to repeatedly and undesirably open and close valve 117 with little or no benefit. Therefore, in an alternative implementation, the control system can determine whether the input data meets two criteria. If there is a high risk of a surge condition, the control system determines that the first "surge" criterion is met (the control system finds it to be "true"); and if there is a high risk of a blockage condition, the second "blockage" criterion is met (the control system finds it to be "true"). The surge criterion and the blockage criterion can be designed such that if one criterion is met, the other is not, and there can also be compressor operating conditions where neither criterion is met. If the control system determines that the surge condition is met, the control system controls valve 117 to be in a closed configuration; that is, if valve 117 is not already in a closed configuration, the control system moves valve 117 to the closed configuration. If the gas choking condition is met, the control system will control valve 117 to be in the open position; that is, if valve 117 is not already in the open configuration, the control system will move valve 117 to the open configuration. If neither condition is met, the control system may not modify the valve configuration. Providing both surge and gas choking criteria means that fluctuations in engine operating conditions are unlikely to cause the control system to open / close the valve, because fluctuations that, for example, cause the gas choking criterion (from being "true") to being "false" do not necessarily cause the surge criterion to become "true".

[0063] For example, a first criterion could be that the measured pressure (e.g., the pressure in the downstream MWE slot) is higher than a first threshold, and a second criterion could be that the measured pressure (e.g., the pressure in the downstream MWE slot) is lower than a second threshold. The first threshold could be the same as the second threshold (i.e., only one criterion for the open / close valve). Alternatively, the first threshold could be higher than the second threshold, such that the first and second criteria are different. In this case, there exists a range of measured pressures where neither of these criteria is met. The valve can be open or closed depending on which of the first and second criteria is most recently met.

[0064] Go to Figure 8 The illustration shows a second embodiment of the present invention. Figures 4 to 6 Elements with the same meaning are given the same reference numerals. In contrast to the first embodiment, in the second embodiment, an additional "surge conduit" 203 is provided, which communicates at an opening 201 with the impeller chamber 16 downstream of the compressor impeller 6. Figure 8In the diagram, opening 201 is shown located on the volute 12, but other locations on the compressor are also possible. Surge duct 203 communicates with gas chamber 105 via surge valve 205.

[0065] In a "dead heading condition," where airflow from compressor outlet 13 to the engine manifold is blocked or impeded, and pressure surges or spikes occur downstream of compressor impeller 6, surge valve 205 allows gas to travel along surge duct 203 to gas chamber 105. This allows pressure downstream of compressor impeller 6 to be released without the gas being driven back through compressor impeller 6, which could potentially damage compressor impeller 6 or cause instability.

[0066] For example, if the pressure downstream of compressor impeller 6 is higher than a surge threshold (an absolute pressure threshold, or a pressure threshold compared to the pressure in gas chamber 105), the surge valve can be controlled to open. For example, the surge valve 205 can be controlled based on a sensor located in surge conduit 203 or downstream of compressor impeller 6, or based on the current operating state of the engine manifold. Alternatively, the surge valve 205 can be designed to open without external control when the pressure in surge conduit 203 is higher than the pressure in gas chamber 105 by an amount exceeding the surge threshold.

[0067] Similarly, valve 117 can be opened if a dead heading becomes a risk (i.e., if the third "dead heading" criterion is met), allowing gas entering gas chamber 105 through surge valve 205 to travel through valve 117 and along conduit 103 to inlet chamber 111. Therefore, if the risk of an existing gas blockage condition exceeds a threshold (the second "gas blockage" criterion discussed above), or if the third "dead heading" criterion indicating a dead heading condition is met (e.g., if the pressure in surge conduit 203 is higher than the threshold, or higher than the pressure in conduit 103 by an amount exceeding the threshold), valve 117 provides gas communication between conduit 103 and gas chamber 105. If neither the second nor the third criterion is met, for example, if the first criterion is met, valve 117 can be closed.

[0068] Figure 9 A third embodiment of the compressor according to the present invention is shown. Similarly, with... Figures 4 to 6 Elements having the same meaning are given the same reference numerals. In contrast to the second embodiment, in the third embodiment, the surge duct 303 extends between the first opening 301 of the surge duct 303 downstream of the compressor impeller 6 (e.g., in the volute 12) and the valve 317, which replaces the valve 117 of the first and second embodiments.

[0069] Valve 317 is operable to be controlled or configured to allow gas to flow from surge duct 303 into duct 103 under dead-head conditions (i.e., if the third "dead-head" criterion is met). Therefore, if the second criterion is met (e.g., the aforementioned second criterion indicating a risk of an existing gas blockage exceeding a threshold), valve 317 provides gas communication between duct 103 and gas chamber 105, and if the third "dead-head" criterion is met, valve 317 provides gas communication between surge duct 303 and duct 103. Thus, similarly, under dead-head conditions, the gas flow through surge duct 303 releases excessive pressure downstream of compressor impeller 6 without reversing the flow of gas through compressor impeller 6. If neither the second nor the third condition is met (and optionally, if the aforementioned first criterion is met), valve 317 can be controlled to close, thereby preventing gas communication from duct 103 to surge duct 303 or gas chamber 105.

[0070] Although only three embodiments of the present invention have been described, many variations are possible within the scope of the invention as defined in the claims. For example, in Figures 4 to 6 In a variant of the compressor housing, pipe 103 may not lead to inlet chamber 111, but may be arranged to communicate with another gas source through an inlet of pipe 103 that is separate from the inlet of inlet chamber 111.

Claims

1. A compressor housing for a compressor: A compressor housing that defines an airflow path between the compressor inlet and the compressor outlet, and defines a rotor chamber located on the airflow path, the rotor chamber being used to receive a compressor rotor to rotate about an axis within the rotor chamber; The compressor housing defines: At least one upstream slit, located in the wall, is used to deliver gas into the impeller chamber at a first axial position; as well as A gas chamber that extends about at least a portion of the axis; in, The at least one upstream slot maintains constant fluid communication with the inlet of the compressor; Its characteristic is that it further includes: A valve that selectively allows gas to enter the gas chamber; and At least one downstream slot for transferring gas from the gas chamber to the rotor chamber at a second axial position downstream of the first axial position.

2. The compressor housing according to claim 1, wherein, The at least one upstream slot is in fluid communication with a channel separated from the gas chamber by a wall.

3. The compressor housing according to claim 1, wherein, The valve is positioned on a single gas path entering the gas chamber from the upstream side, and the valve is operable to control the gas path entering the gas chamber.

4. A compressor, characterized in that, include: The compressor housing according to claim 1; and A compressor impeller is disposed in the airflow path within the impeller chamber defined by the wall of the compressor housing, and the compressor impeller is used to rotate about the axis.

5. The compressor according to claim 4, wherein, The compressor impeller includes one or more main blades and one or more branch blades, the leading edge of the main blades being further upstream in the axial direction than the leading edge of the branch blades, and the first axial position being located from the leading edge of the main blades in the downstream axial direction and from the leading edge of the branch blades in the upstream axial direction.

6. The compressor according to claim 5, wherein, The second axial position is located from the leading edge of the splitter blade along the downstream axial direction.

7. The compressor according to any one of the preceding claims further includes a control system configured to control the valve to be in an open or closed configuration based on input data indicating current operating conditions of the compressor or a turbomachinery including the compressor.

8. The compressor according to claim 7, wherein, The control system is capable of operating as follows: Determine whether the input data meets the criteria for indicating the presence of air blockage. When the input data is determined to meet the criteria, the valve is controlled to be in an open configuration; and When it is determined that the input data does not meet the standard, the valve is controlled to be in a closed configuration.

9. The compressor according to claim 7, wherein, The control system is operable to determine whether the input data meets two criteria, wherein... The control system determines whether a first criterion is met, wherein the risk of an existing surge condition is higher than a threshold. The control system determines whether a second criterion is met, wherein the risk of a present air-blocking condition is higher than a threshold. If the first criterion is determined to be met, the control system controls the valve to be in the closed configuration. If the second criterion is determined to be met, the control system controls the valve to be in the open configuration; and If it is determined that neither of the two criteria is met, the control system will not modify the configuration of the valve.

10. The compressor of claim 7, further comprising a surge conduit having a first opening downstream of the compressor impeller, wherein, When the third criterion indicating the presence of a dead heading is met, the valve allows gas to flow from the surge duct to the inlet of the compressor.

11. The compressor according to claim 10, wherein, The surge conduit is connected to the gas chamber via a surge valve, and if the third criterion is met, the valve and the surge valve allow gas to flow from the surge conduit through the gas chamber to the inlet of the compressor.

12. The compressor according to claim 10, wherein, The surge conduit is connected to the valve, and if the third criterion is met, the valve allows gas to flow from the surge conduit to the inlet of the compressor.

13. A turbomachinery, characterized in that, The compressor includes the compressor according to claim 1, wherein the central portion of the compressor impeller is connected to the drive shaft of the turbomachinery.

14. The turbomachinery according to claim 13, wherein the turbomachinery is a turbocharger.

15. An engine, characterized in that, Includes the turbocharger according to claim 14.

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