Treatment of non-axisymmetric housing with corrugated pressurizing portion

Abstract

The invention relates to a turbomachine compressor (300), comprising an inner annular wall (111) and an outer annular wall (121), the inner annular wall (111) and the outer annular wall (121) defining therebetween an annular cavity (130) extending in an axial direction (DA) between a front bottom (131) and a rear bottom (132) and in a radial direction (DR) between an inner face portion (1210) of the outer annular wall and an outer face portion (1111) of the inner annular wall. The inner annular wall of the housing comprises a plurality of grooves (115) opening into the annular cavity (130), the grooves being arranged adjacent to each other in an axial direction (DC). The inner face portion (1210) of the outer annular wall (120) includes concave and convex portions alternately arranged in the circumferential direction so as to define a corrugation (140) in the inner cavity (130) in the circumferential direction (DC).

Description

Technical Field

[0001] This invention relates to the general field of turbine compressors, and more specifically, to the treatment of turbine compressor housings. Background Technology

[0002] A turbine compressor consists of blades that rotate inside a housing that seals the air ducts to the outside of the engine.

[0003] It is well known that the gap between the ends of the moving compressor blades and the housing that forms the inner wall of the airflow duct reduces the efficiency of a turbine engine.

[0004] Furthermore, this gap alters and reduces compressor operation until surge occurs, which is caused by airflow separating from the blade surface. Controlling airflow at the blade tips is a significant challenge if the compressor is to achieve good aerodynamic efficiency and sufficient surge margin.

[0005] To limit the effects of parasitic flow between the blade tips and the housing, the internal surface of the housing can be locally treated by cutting several grooves in the thickness of the housing opposite the blades. The housing treatment considered in this invention is of the "axial groove" type, corresponding to a series of grooves arranged along the periphery (azimuth direction) of the housing. These grooves are located vertically above the compressor impeller. Therefore, these treatments are non-axisymmetric with respect to the compressor's axis of rotation: thus, they relate to non-axisymmetric housing treatment, or NACT.

[0006] The presence of these grooves will locally modify the flow. Their purpose is to influence the mechanisms that cause compressor surge. Effective casing treatment will increase the compressor's operating range by delaying the occurrence of these mechanisms, particularly by reducing aerodynamic blockage at the impeller head.

[0007] Some NACT concepts propose adding an annular cavity or "boost unit" to the housing, such as described in document WO9420759, which is equivalent to adding a cavity above the slots. This cavity extends around the entire circumference of the housing and connects the slots together. This cavity does not directly connect to the duct or the secondary air circuit. Fluid must pass through the slots to enter and exit the cavity. Adding a boost unit often increases the capacity of the NACT to increase surge margin.

[0008] An annular cavity can be used to extract a portion of the fluid through one slot and re-inject it through different slots, which improves the efficiency of shell treatment (compared to shell treatment without an annular cavity). However, this mechanism is not optimal because the re-injection is distributed among several slots, and some of these slots are not well positioned relative to the rotor during re-injection.

[0009] Therefore, it is desirable to have better control over the extraction and re-injection zones at the tank. Summary of the Invention

[0010] To this end, the present invention provides a housing for a turbine compressor, the housing comprising an inner annular wall and an outer annular wall defining an annular cavity therebetween, the annular cavity extending axially between a front end and a rear end, and extending radially between an inner portion of the outer annular wall and an outer portion of the inner annular wall. The inner annular wall of the housing includes a plurality of slots opening into the annular cavity, the slots being arranged adjacent to each other in the axial direction, and the slots extending longitudinally along a longitudinal axis between the front end and the rear end in the axial direction.

[0011] The outer annular wall is characterized by having an inner surface portion of the plurality of grooves facing the inner annular wall, comprising a concave portion and a convex portion, which are alternately arranged in the circumferential direction to define a corrugated portion within the defined inner cavity in the circumferential direction. The concave portion and the convex portion each extend in the longitudinal direction between the front and rear ends of the inner cavity.

[0012] The longitudinal direction forms a non-zero angle with the longitudinal axis of the groove.

[0013] Alternatively, the longitudinal direction is parallel to the longitudinal axis of the groove, and each corrugated part extends circumferentially over two or more adjacent grooves.

[0014] When the concave and convex portions each extend between the front and rear ends of the inner cavity along a longitudinal direction forming a non-zero angle with the longitudinal axis of the groove, the concave portion forming a circulation channel for flow within the inner cavity allows for the offset of the fluid extraction zone and the fluid re-injection zone at the groove. Depending on the value of the angle, it is possible to determine one or more grooves through which fluid is drawn into the inner cavity and one or more grooves through which fluid is re-injected.

[0015] With the concave and convex portions extending between the front and rear ends of the inner cavity in a longitudinal direction parallel to the longitudinal axis of the groove, and each corrugated portion extending in a circumferential direction above two or more adjacent grooves, it is also possible to exchange between several adjacent grooves in the same circulation channel for flow in the inner cavity, and to offset the fluid extraction zone and fluid re-injection zone at the groove.

[0016] The presence of corrugations allows for better control of the flow path within the annular cavity. Guiding fluid through the corrugations in the inner cavity optimizes the operation of the non-axisymmetric shell treatment (NACT). In this way, it is possible to control one or more slots through which a portion of the flow is re-injected, thereby controlling the re-injection time relative to the rotor position, which increases the surge margin gain. By limiting the azimuth migration of the extracted flow, pressure losses during circulation within the inner cavity are reduced, thus optimizing the operation of NACT.

[0017] The non-zero angle formed between the longitudinal direction of the concave and convex portions and the longitudinal axis of the groove is between -60° and +60°, preferably between -40° and +40°.

[0018] According to another specific feature of the invention, when the longitudinal directions of the concave and convex portions form a non-zero angle with the longitudinal axis of the groove, the width of each concave portion is at least equal to the width of a groove in the inner ring wall.

[0019] According to another specific feature of the invention, when a non-zero angle is formed between the longitudinal direction of the concave portion and the convex portion and the longitudinal axis of the groove, the number of corrugations present on the inner surface of the outer wall is between 0.1 and 1 times the number of grooves present in the inner annular wall.

[0020] According to another specific feature of the invention, the amplitude of the corrugated portion formed by the alternating concave and convex portions arranged in the circumferential direction is between 0.2 and 5 times the height of the groove in the inner annular wall.

[0021] According to another specific feature of the invention, the housing includes a processing ring and a main ring, the processing ring including an inner annular wall, the main ring including an outer annular wall, and the processing ring being fixed to the main ring.

[0022] According to another specific feature of the invention, the processing ring and the main ring are made of the same material.

[0023] The present invention also relates to a turbine compressor comprising a housing according to the invention. Attached Figure Description

[0024] Other features and advantages of the invention will become apparent from the description given below with reference to the accompanying drawings, which illustrate exemplary embodiments of the invention in a manner that is by no means limiting.

[0025] [ Figure 1 ] Figure 1 This is a schematic perspective view of a turbine compressor according to an embodiment of the present invention;

[0026] [ Figure 2 ] Figure 2 It is shown Figure 1A schematic partial view of the corrugated portion present on the inner surface of the main ring of the compressor;

[0027] [ Figure 3 ] Figure 3 yes Figure 1 A schematic partial view of the compressor housing;

[0028] [ Figure 4 ] Figure 4 It is along Figure 3 A radial sectional view of the shell taken from section IV-IV;

[0029] [ Figure 5 ] Figure 5 It is along Figure 3 The radial sectional view of the shell section VV. Detailed Implementation

[0030] Figure 1 A turbine compressor 300 according to an embodiment of the present invention is shown. The compressor 300 includes components surrounding its axis A. 300 The rotor 200 is equipped with multiple moving blades 210 surrounded by a housing 100.

[0031] The housing 100 includes a processing ring 110 and a structural main ring 120. In the example described herein, the processing ring 110 includes a flange 116 that is attached to a flange 126 of the main ring 120.

[0032] like Figure 3 As schematically and partially shown, the main ring 120 includes an outer annular wall 121, while the processing ring 110 includes an inner annular wall 111 opposite to the outer annular wall 121. The inner annular wall 111 and the outer annular wall 121 each extend along the circumferential direction D in length. C Extending in width along the axial direction D corresponding to the axis of compressor 300 A Extending, in thickness along the radial direction D R Extended. An inner annular wall 111 and an outer annular wall 121 define an annular cavity 130 forming a pressurization section between them. The inner annular cavity 130 extends axially in the direction D between the front end 131 and the rear end 132. A Extending radially D between the inner portion 1210 of the outer annular wall 121 and the outer portion 1111 of the inner annular wall 111. R extend.

[0033] The inner annular wall 111 includes a plurality of slots 115 hollowed out (or cut out) in the thickness of the wall, each slot 115 opening both into the inner surface 1110 and the outer surface 1111 of the inner annular wall 111 to accommodate a flow duct E communicating with the annular cavity 130, with arrow E indicating the flow direction in the compressor, thereby indicating its upstream and downstream sides.

[0034] Groove 115 is located in the inner annular wall 111 along the circumferential direction D C They are arranged evenly adjacent to each other. Each slot 115 is along the longitudinal axis A in length. 115 Extend a given length L 115 In terms of height, in the radial direction D R Upward extension height H 115 In the example described here, the longitudinal axis A of slot 115 115 Parallel to the axial direction D A However, it can be related to the axial direction D. A It forms an angle between -60° and +60°.

[0035] In the example described here, slot 115 is relative to the radial direction D R Inclined at 45°. Groove 115 can be inclined at angles other than 45°, or parallel to the radial direction D. R .

[0036] In a known manner, the slots 115 and the annular cavity 130 to which they open constitute a non-axisymmetric shell treatment or NACT, which can locally alter the flow to reduce mechanisms that cause compressor surge.

[0037] According to the present invention, the inner portion 1210 of the plurality of grooves 115 of the outer annular wall 121 facing the inner annular wall 111 includes a portion D along the circumferential direction. C Alternating concave portions 1212 and convex portions 1213, thereby extending along the circumferential direction D within the inner cavity 130. C Limited ripple section ( Figure 2 , 4 and 5).

[0038] like Figure 2 As shown, the concave portion 1212 and the convex portion 1213 are respectively located along the longitudinal axis D between the front end 131 and the rear end 132 of the inner cavity 130. 140 Extension. The concave portion 1212 defines a circulation channel for guiding flow within the inner cavity 130.

[0039] In the example described here, the longitudinal directions of the concave portion 1212 and the convex portion 1213 are parallel to the longitudinal axis A of the groove 115. 115 Formation angle β 140 Angle β140 The angle is between -60° and +60°, preferably between -40° and +40°. The concave portion forms a circulation channel for flow within the inner cavity, allowing for the elimination of fluid extraction and re-injection zones at the groove. According to angle β... 140 The value of determines whether it is possible to draw fluid into one or more channels of the inner cavity and to re-inject fluid from one or more channels.

[0040] An example of the offset between the extraction and re-injection zones in the cavity is as follows: Figure 4 and Figure 5 As shown, corresponding to Figure 3 The radial cross-section of the shell shown. Figure 4 The cross-section shown is located upstream of the leading edge 211 of the blade 210 of the rotor 200 in the axial direction, and intersects with the slot 115 in its upstream portion. Figure 5 The cross-section is located downstream of the leading edge 211 of the blade 210 of the rotor 200 in the axial direction and intersects with the slot 115 in its downstream portion. Figure 4 and Figure 5 The grooves 1151 to 1156 shown correspond to the same grooves in the inner annular wall 111. Similarly, Figure 4 and Figure 5 The concave portion 12121 shown corresponds to the same concave portion of the defined circulation channel 136 of the outer annular wall 121. Due to the longitudinal direction D of the concave and convex portions... 140 With the longitudinal axis A of the groove 115 The angle β formed between them 140 The concave portion 12121 is in Figure 4 and Figure 5 They have different azimuth positions, and the longitudinal axis A of the groove 115 Here, the axial direction D corresponds to the axis of compressor 300. A coincide( Figure 3 In the example described here, angle β 140 It is approximately 37°.

[0041] Because the concave portion 12121 is inclined relative to the longitudinal axis of the groove, such as Figure 5 As shown, a portion of the flow F E It is extracted through slots 1154 and 1155. Then this part F is... E The fluid is guided into circulation channel 136 and then injected into flow channel E through grooves 1153 and 1154, as shown in the example. Figure 4 As shown. Here it can be seen that the inclined concave portion allows the fluid to be guided, so that the fluid flows from slot 1155 to slot 1153 as it passes through the inner cavity, i.e., in the example considered here, there is an azimuth offset between the two slots.

[0042] The width l of each concave portion 1212 1212 At least equal to the width l of slot 115 115 ( Figure 2 and Figure 3 ).

[0043] The height H corresponding to the concave portion 1212 1212 The amplitude of the corrugated section is at the height H of groove 115. 115 Between 0.2 and 5 times ( Figure 3 and Figure 4 ).

[0044] The number of corrugated sections is between 0.1 and 1 times the number of grooves 115 present on the processing ring 110.

[0045] The number of slots 115 present on the processing ring 110 is 2 to 10 times the number of blades 210 of the rotor 200. The number of slots on a blade is typically 5.

[0046] The main ring and the processing ring are preferably made of the same material or materials with similar coefficients of thermal expansion to avoid expansion differences between the two rings, which could lead to mechanical stress and / or sealing problems in the housing.

[0047] The phrase “…to…” should be understood to include limitations.

Claims

1. A housing (100) for a turbine compressor (300) comprising an inner annular wall (111) and an outer annular wall (121) defining an annular cavity (130) therebetween, the annular cavity being axially (D) between a front end (131) and a rear end (132). A ) extends radially (D) between the inner portion (1210) of the outer annular wall and the outer portion (1111) of the inner annular wall. R Extending from the inner annular wall (111) of the housing, the annular wall includes a plurality of grooves (115) opening into the annular cavity (130), the grooves being axially (D... C The grooves are arranged adjacent to each other on the front end (131) and the rear end (132) along the longitudinal axis (A) in the axial direction. 115 Extending longitudinally, Its features are, The inner surface (1210) of the outer annular wall (121) facing the plurality of grooves (115) in the inner annular wall (111) includes a concave portion (1212) and a convex portion (1213), the concave portion and the convex portion being arranged alternately in the circumferential direction, so as to be along the circumferential direction (D C A corrugated portion (140) is defined in the inner cavity (130), wherein the concave portion (1212) and the convex portion (1213) are respectively along the longitudinal direction (D) 140 The longitudinal direction extends between the front end (131) and the rear end (132) of the inner cavity (130), wherein the longitudinal direction is perpendicular to the longitudinal axis (A) of the groove (115). 115 ) forms a non-zero angle (β) 140 Alternatively, the longitudinal direction may be parallel to the longitudinal axis of the groove, and each corrugated portion may extend along the circumferential direction over two or more adjacent grooves.

2. The housing according to claim 1, characterized in that, The longitudinal direction (D) of the concave portion (1212) and the convex portion (1213) 140 ) and the longitudinal axis (A) of the groove (115) 115 The non-zero angle (β) formed between ) 140 (Between -60° and +60°) 3. The housing according to claim 2, characterized in that, The width (l) of each concave portion (1212) 1212 The width of the groove (115) of the inner annular wall (111) is at least equal to the width of the groove (115).

4. The housing according to claim 2 or 3, characterized in that, The number of corrugated portions present on the inner surface (1210) of the outer wall (121) is between 0.1 and 1 times the number of grooves (115) present in the inner annular wall (111).

5. The housing according to any one of claims 1 to 4, characterized in that, From along the circumferential direction (D) C The amplitude of the corrugated portion formed by the alternating concave portions (1212) and convex portions (1213) is the height (H) of the groove (115) in the inner ring wall (111). 115 It is between 0.2 and 5 times that of ).

6. The housing according to any one of claims 1 to 5, characterized in that, It includes a processing ring (110) and a main ring (120), the processing ring including an inner annular wall (111) and the main ring including an outer annular wall (121), the processing ring being fixed to the main ring.

7. The housing according to claim 6, characterized in that, The processing ring and the main ring are made of the same material.

8. A turbine compressor (300) comprising a housing (100) according to any one of claims 1 to 7.

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