Exhaust diffuser, turbine assembly and gas turbine

Abstract

The invention provides an exhaust diffuser, a turbine assembly and a gas turbine, the exhaust diffuser comprises an annular diffuser and a plurality of support plate assemblies, the annular diffuser is connected with an exhaust end of a turbine, a mounting area is defined between the peripheral wall of the annular diffuser and the peripheral wall of a rotor shaft end, the support plate assemblies are arranged in the mounting area, and the support plate assemblies are arranged in the mounting area. The multiple supporting plate assemblies are arranged in the circumferential direction of the rotor shaft end at intervals, each supporting plate assembly comprises a fixed supporting plate and a rotating supporting plate, the fixed supporting plates are connected between the rotor shaft end and the annular diffuser, the rotating supporting plates are connected with the fixed supporting plates, the rotating supporting plates are located on the sides, close to the turbine, of the fixed supporting plates, and the rotating supporting plates can rotate around the first axial direction. The first axial direction is orthogonal to the axial direction of the rotor shaft end. According to the exhaust diffuser, the total pressure loss can be effectively reduced, and the diffusion effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbines, and in particular, to an exhaust diffuser, a turbine assembly, and a gas turbine. Background Art

[0002] An exhaust diffuser is designed at the turbine outlet of a gas turbine to recover the kinetic energy of the turbine exhaust gas, enabling the turbine components to obtain a greater total static pressure ratio and increasing the turbine output power. The exhaust diffuser adopts an axial exhaust method that combines an annular diffuser and a conical diffuser in its structure. There are blade-shaped support plates arranged circumferentially inside the annular diffuser, and a support structure is wrapped inside the support plates.

[0003] In the related art, the blade-shaped support plates of the exhaust diffuser are fixed. Under the design conditions, the turbine outlet airflow is close to the axial direction, and good rectification can be obtained after passing through the support plates, achieving a good pressure diffusion effect. However, under off-design conditions, the turbine exhaust gas will deviate from the axial direction, and the airflow passing through the fixed exhaust support plates will induce relatively serious flow separation. Under the action of flow separation and swirl, the exhaust loss increases after the airflow passes through the blade-shaped support plates, and a good pressure diffusion effect cannot be obtained, and the turbine output work will also be affected. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to some extent.

[0005] To this end, an embodiment of the present invention provides an exhaust diffuser, a turbine assembly, and a gas turbine, and the exhaust diffuser can effectively reduce the total pressure loss and improve the pressure diffusion effect.

[0006] The exhaust diffuser according to an embodiment of the present invention includes:

[0007] An annular diffuser, which is connected to the exhaust end of the turbine, and an installation area is defined between the peripheral wall of the annular diffuser and the peripheral wall of the rotor shaft end;

[0008] A support plate assembly, which is arranged in the installation area. The support plate assembly is plural, and the plural support plate assemblies are arranged at intervals along the circumferential direction of the rotor shaft end. The support plate assembly includes a fixed support plate and a rotating support plate. The fixed support plate is connected between the rotor shaft end and the annular diffuser, the rotating support plate is connected to the fixed support plate, and the rotating support plate is located on the side of the fixed support plate adjacent to the turbine. The rotating support plate is rotatable about a first axial direction, and the first axial direction is orthogonal to the axial direction of the rotor shaft end.

[0009] Through the design of the rotating support plate in the exhaust diffuser according to the embodiment of the present invention, the exhaust diffuser can automatically adjust the position of the support plate according to the airflow deflection under off-design conditions, thereby reducing flow separation and swirl and improving the pressure diffusion effect.

[0010] In some embodiments, in a plane orthogonal to the axial direction of the rotor shaft end, the cross-sectional area of the rotating support plate gradually decreases in the direction from the fixed support plate to the rotating support plate.

[0011] In some embodiments, in a plane parallel to the axial direction of the rotor shaft end, the cross-sectional profile of the rotating support plate is arc-shaped.

[0012] In some embodiments, one end of the fixed support plate adjacent to the rotating support plate has an arc-shaped groove, one end of the rotating support plate adjacent to the fixed support plate is convex arc-shaped, and one end of the rotating support plate adjacent to the fixed support plate is adapted to the arc-shaped groove.

[0013] In some embodiments, the angle by which the rotating support plate can rotate about the first axial direction is less than or equal to 120 degrees.

[0014] In some embodiments, one end of the fixed support plate adjacent to the rotating support plate is connected to the rotating support plate through a smooth surface transition.

[0015] In some embodiments, in a plane parallel to the axial direction of the rotor shaft end, the cross-sectional profile of the fixed support plate is arc-shaped.

[0016] In some embodiments, the fixed support plate has a chamber, and the chamber extends in a direction orthogonal to the axial direction of the rotor shaft end.

[0017] The turbine assembly according to an embodiment of the present invention includes a turbine body and a diffuser, the diffuser is connected to the end of the turbine body, and the diffuser is an exhaust diffuser according to any one of the above embodiments.

[0018] The gas turbine according to an embodiment of the present invention includes the turbine assembly according to the above embodiment. Description of the Drawings

[0019] Figure 1 is a three-dimensional structural schematic diagram of the exhaust diffuser according to an embodiment of the present invention.

[0020] Figure 2 is a planar structural schematic diagram of the exhaust diffuser according to an embodiment of the present invention.

[0021] Figure 3 is a first cross-sectional schematic diagram of the support plate assembly of the exhaust diffuser according to an embodiment of the present invention.

[0022] Figure 4 is a first cross-sectional schematic diagram of the support plate assembly of the exhaust diffuser according to an embodiment of the present invention.

[0023] Figure 5 is a streamline diagram of a fixed vane support plate in the related art.

[0024] Figure 6 It is a streamline diagram of the strut assembly (adjustable vane strut) of the exhaust diffuser according to an embodiment of the present invention.

[0025] Figure 7 It is a comparison diagram of the exit wake widths of the fixed vane strut and the adjustable vane strut.

[0026] Figure 8 It is a schematic structural diagram of the rotating strut of the exhaust diffuser according to an optional embodiment of the present invention.

[0027] Reference numerals:

[0028] 100, turbine; 200, rotor shaft end

[0029] 1, annular diffuser; 11, installation area

[0030] 2, conical diffuser

[0031] 3, strut assembly; 31, fixed strut; 311, arc-shaped groove; 315, chamber; 32, rotating strut; 321, convex arc Detailed implementation manners

[0032] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention and should not be construed as a limitation to the present invention.

[0033] The exhaust diffuser according to an embodiment of the present invention will be described below with reference to the drawings.

[0034] As Figures 1 - 8 shown, the exhaust diffuser according to an embodiment of the present invention includes: an annular diffuser 1 and a strut assembly 3.

[0035] The annular diffuser 1 is connected to the exhaust end of the turbine 100, and an installation area 11 is defined between the circumferential wall of the annular diffuser 1 and the circumferential wall of the rotor shaft end 200. The strut assembly 3 is disposed in the installation area 11. There are a plurality of strut assemblies 3, and the plurality of strut assemblies 3 are arranged at intervals in the circumferential direction of the rotor shaft end 200. The strut assembly 3 includes a fixed strut 31 and a rotating strut 32. The fixed strut 31 is connected between the rotor shaft end 200 and the annular diffuser 1. The rotating strut 32 is connected to the fixed strut 31, and the rotating strut 32 is located on the side of the fixed strut 31 adjacent to the turbine 100. The rotating strut 32 is rotatable about a first axial direction, and the first axial direction is orthogonal to the axial direction of the rotor shaft end 200.

[0036] Specifically, as Figures 1 - 4As shown, the left end of the annular diffuser 1 is connected to the right end of the turbine 100 (i.e., the exhaust end of the turbine 100), and an air flow passage is formed between the annular diffuser 1 and the rotor shaft end 200. The fixed support plate 31 is connected between the rotor shaft end 200 and the annular diffuser 1 to provide structural support. The rotating support plate 32 is connected to the fixed support plate 31 and is located on the side of the fixed support plate 31 close to the turbine 100, so that when the rotating support plate 32 rotates around the first axis, the air flow direction passing through the installation area 11 can be changed.

[0037] Optionally, in practical applications, the annular diffuser 1 can be connected to the conical diffuser 2, that is, as Figure 1 shown, the annular diffuser 1 and the conical diffuser 2 are connected in sequence from left to right to further compress the gas. Of course, it can also be connected to diffusers of other specifications to adapt to the actual use scenarios. The following takes the Figure 1 connection method shown as an example for illustration.

[0038] It can be understood that, as Figures 1 - 4 shown, a shaft hole is provided on the rotating support plate 32, and the rotating support plate 32 can be connected to the fixed support plate 31 through the cooperation of a rotating shaft and the shaft hole. Thus, the axial direction of this rotating shaft is the first axis. That is to say, under off-design conditions, the fixed support plate may cause relatively large energy losses. The rotatable support plate can better adapt to the air flow changes, reduce energy losses, and improve the output power of the turbine 100. The rotatable support plate can optimize the rectification effect of the air flow, ensuring that the air flow still has good directivity after passing through the support plate even under off-design conditions, thereby improving the working efficiency of the diffuser.

[0039] In addition, the design of the rotating support plate 32 increases the flexibility of the system, helps to avoid structural fatigue or damage caused by air flow deflection, and thus improves the reliability and service life of the entire system. The design of the support plate assembly 3 makes the maintenance work more convenient. The support plate assembly 3 can be repaired or replaced separately without having to disassemble the entire diffuser on a large scale.

[0040] In other words, under design conditions, enabling the rotating support plate 32 to be designed with a leading edge angle according to the radial distribution of the aerodynamic parameters can make the rotating support plate 32 face the oncoming flow and reduce the attack angle loss. Under off-design point conditions, the air flow angle at the outlet of the turbine 100 will deviate from the axial position. Through the design of the adjustable rotating support plate 32, the rotating support plate 32 can be made to face the oncoming flow direction as much as possible under off-design conditions, reducing the degree of flow separation and improving the off-design point aerodynamic performance of the exhaust diffuser of the turbine 100.

[0041] The inventor conducted the following tests on the adjustable support plate assembly 3 and the aerodynamic parameter adjustment of the fixed blade support plate according to the exhaust diffuser of the embodiment of the present invention:

[0042] parameter fixed scheme adjustable scheme total pressure loss 1.062 kPa 0.891 kPa exit gas flow angle 9.17° 8.37°

[0043] Table 1

[0044] As Figures 5 - 7 shown, by comparing the flow analysis results of the fixed vane strut and the adjustable strut assembly 3, with the adjustable design, the total pressure loss of the vane strut can be reduced from 1.062 kPa to 0.891 kPa, and the outlet air flow angle is more biased towards the axial direction (as shown in Table 1), and a better diffusing effect can be obtained in the downstream conical diffuser 2.

[0045] Thus, through the design of rotating the strut 32 in the exhaust diffuser according to the embodiments of the present invention, the exhaust diffuser can automatically adjust the position of the strut according to the air flow deflection under off-design conditions, thereby reducing flow separation and swirl and improving the diffusing effect.

[0046] In some embodiments, in a plane orthogonal to the axial direction of the rotor shaft end 200, the cross-sectional area of the rotating strut 32 gradually decreases in the direction from the fixed strut 31 to the rotating strut 32.

[0047] It can be understood that, as Figures 1 - 4 shown, the cross-sectional area of the rotating strut 32 gradually decreases in the direction from right to left. That is to say, through the rotation of the rotating strut 32, a gradually changing flow channel is formed inside the installation area 11, which is beneficial to the smooth flow of the air flow through the strut and reduces the flow resistance. The gradually changing cross-sectional area of the rotating strut 32 enables the strut to better adapt to the change of the air flow under different working conditions. Especially under off-design conditions, the rotating strut 32 can be adjusted as needed to maintain high performance.

[0048] Optionally, in a plane parallel to the axial direction of the rotor shaft end 200, the cross-sectional profile of the rotating strut 32 is arc-shaped. It can be understood that, as Figures 1 - 4 shown, the arc-shaped design enables the rotating strut 32 to better adapt to the curved movement of the air flow during rotation. The arc-shaped profile can better match the streamline of the air flow and reduce the impact and turbulence generated due to the change of the air flow direction.

[0049] In addition, the arc of the cross-sectional profile of the rotating strut 32 can be a whole; or multiple arcs can be spliced, that is, the curvature of the multiple spliced arcs in the rotating strut 32 gradually increases from right to left, so that when the air flow flowing into the installation area 11 contacts the end of the rotating strut 32, it is more beneficial to the flow of the air flow. That is, the arc-shaped design enables the strut assembly 3 to better adapt to the air flow changes under different working conditions. Especially under off-design conditions, the arc-shaped profile helps to maintain the stability of the air flow.

[0050] In some embodiments, one end of the fixed support plate 31 adjacent to the rotating support plate 32 has an arc-shaped groove 311, one end of the rotating support plate 32 adjacent to the fixed support plate 31 is a convex arc 321, and one end of the rotating support plate 32 adjacent to the fixed support plate 31 is adapted to the arc-shaped groove 311.

[0051] Specifically, as Figures 1 - 4 shown, an arc-shaped groove 311 is provided at the left end of the fixed support plate 31, and a convex arc 321 matching the arc-shaped groove is provided at the right end of the rotating support plate 32. Then, the right end of the rotating support plate 32 can be fitted into the arc-shaped groove 311 at the left end of the fixed support plate 31, so that the transition of the adjacent parts between the rotating support plate 32 and the fixed support plate 31 is smoother.

[0052] It can be understood that through the cooperation of the arc-shaped groove 311 and the convex arc 321, the rotating support plate 32 can be adjusted more flexibly according to the change of the air flow, improving the adaptability of the exhaust diffuser under different working conditions. The design of the fitting connection reduces the gap between the rotating support plate 32 and the fixed support plate 31, thereby reducing the leakage when the air flow passes through and improving the diffusing efficiency. The combination of the ends of the arc-shaped groove 311 and the convex arc 321 provides a smoother channel for the air flow, helping to reduce flow separation and turbulence and optimizing the air flow dynamics. The cooperation between the end of the convex arc 321 and the arc-shaped groove 311 increases the stability of the rotating support plate 32, which helps to maintain the structural integrity under high-speed rotation and high-load conditions.

[0053] Optionally, the angle by which the rotating support plate 32 can rotate about the first axis is less than or equal to 120 degrees. It can be understood that, as Figure 4 shown, the angle by which the rotating support plate 32 rotates about the first axis is α. Then, restricting the rotation angle of the rotating support plate 32 helps to more precisely control the rotation of the rotating support plate 32, thereby better adjusting the direction and speed of the air flow to adapt to different working conditions.

[0054] In addition, as Figure 8 shown, the leading edge of the rotating support plate 32 (i.e., the left end of the rotating support plate 32) can be stacked by different blade profiles along its radial direction. That is to say, the rotating support plate 32 can adopt different arc-shaped designs according to the actual working conditions in its height direction, or it is a twisted structure itself, so that different air flow paths can be formed when the rotating support plate 32 contacts the air flow, and thus it is applicable to more scenarios.

[0055] In some embodiments, one end of the fixed support plate 31 adjacent to the rotating support plate 32 is connected to the rotating support plate 32 through a smooth surface transition.

[0056] It can be understood that, as Figure 3 and Figure 4As shown, the right end of the rotating support plate 32 is connected to the left end of the fixed support plate 31 with a smooth curved surface transition, that is, the tangent plane of the side wall at the right end of the rotating support plate 32 coincides with the tangent plane of the side wall at the left end of the fixed support plate 31, making the air flow from the rotating support plate 32 to the fixed support plate smoother, thereby reducing the air flow resistance.

[0057] Preferably, in a plane parallel to the axial direction of the rotor shaft end 200, the cross-sectional contour of the fixed support plate 31 is arc-shaped. It can be understood that the arc-shaped cross-sectional contour of the fixed support plate 31 makes the overall streamline of the outer contour of the fixed support plate 31 neater, making the fixed support plate 31 more stable in structure, capable of withstanding the centrifugal force and the acting force of the air flow generated during high-speed rotation, and improving the durability of the fixed support plate 31.

[0058] Optionally, as Figures 1 - 4 shown, the outer peripheral contour of the fixed support plate 31 can adopt a combination of partial elliptical arcs and semi-circular arcs. Of course, the arc-shaped part of the side wall of the fixed support plate 31 can also be designed according to different working conditions. In addition, other arc designs can also be adopted, such as parabolas, etc.

[0059] In some embodiments, the fixed support plate 31 has a chamber 315, and the chamber 315 extends in a direction orthogonal to the axial direction of the rotor shaft end 200.

[0060] Specifically, as Figures 1 - 4 shown, a chamber 315 is designed inside the fixed support plate 31, and the extending direction of the chamber 315 is the same as the height direction of the fixed support plate 31. The chamber 315 provides an installation space for other devices of the exhaust diffuser. For example, partial support structures can be arranged in the chamber 315 to provide effective support for the flow channel passing through the chamber 315.

[0061] It should be noted that since the fixed support plate 31 is long-term exposed to environments of high temperature, high pressure and high-speed air flow, materials with good high-temperature performance and oxidation resistance, such as nickel-based alloys and cobalt-based alloys, can be used.

[0062] Next, the turbine 100 assembly of the embodiments of the present invention will be described according to the accompanying drawings.

[0063] As Figure 2 shown, the turbine 100 assembly of the embodiments of the present invention includes a turbine 100 body and a diffuser. The diffuser is connected to the end of the turbine 100 body, and the diffuser is an exhaust diffuser according to any one of the above embodiments.

[0064] It can be understood that the turbine 100 component designs the turbine 100 body and the diffuser as a whole, optimizing the transition and management of the air flow, and improving the compactness and overall performance of the system. The diffuser adopts a combination of fixed vanes 31 and rotating vanes 32, thereby improving the air flow management ability of the turbine 100 component, helping to reduce the transition loss of the air flow between the turbine 100 and the diffuser, and improving the overall energy conversion efficiency.

[0065] The gas turbine according to an embodiment of the present invention includes the turbine 100 component according to the above embodiment.

[0066] It can be understood that the gas turbine according to the embodiment of the present invention can improve the thermal efficiency and output power of the gas turbine by optimizing the integrated design of the turbine 100 body and the diffuser. In addition, the design of the vane assembly 3 adopted by the diffuser makes the overall structure more compact, improves the compactness of the turbine 100, and is also convenient for maintenance and repair. The movable vane can be adjusted according to the change of the air flow direction, reducing the flow separation phenomenon when the air flow passes through the vane, and reducing the exhaust loss.

[0067] Of course, the diffuser is not only applicable to gas turbines, but also can be applied to other types of turbine 100 machinery, such as steam turbines.

[0068] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0069] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0070] In the present invention, unless otherwise clearly specified or limited, terms such as "installed", "connected", "coupled", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0072] In the present invention, terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0073] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. An exhaust diffuser, characterized in that, Comprising: An annular diffuser, which is connected to the exhaust end of the turbine, and an installation area is defined between the peripheral wall of the annular diffuser and the peripheral wall of the rotor shaft end; A strut assembly, which is arranged in the installation area. There are multiple strut assemblies, and the multiple strut assemblies are arranged at intervals along the circumferential direction of the rotor shaft end. The strut assembly includes a fixed strut and a rotating strut. The fixed strut is connected between the rotor shaft end and the annular diffuser. The rotating strut is connected to the fixed strut, and the rotating strut is located on the side of the fixed strut adjacent to the turbine. The rotating strut is rotatable about a first axial direction, and the first axial direction is orthogonal to the axial direction of the rotor shaft end.

2. The exhaust diffuser according to claim 1, wherein In a plane orthogonal to the axial direction of the rotor shaft end, the cross-sectional area of the rotating strut gradually decreases in the direction from the fixed strut to the rotating strut.

3. The exhaust diffuser according to claim 2, wherein, In a plane parallel to the axial direction of the rotor shaft end, the cross-sectional profile of the rotating strut is arc-shaped.

4. The exhaust diffuser according to claim 3, characterized in that, One end of the fixed strut adjacent to the rotating strut has an arc-shaped groove, one end of the rotating strut adjacent to the fixed strut is convex arc-shaped, and one end of the rotating strut adjacent to the fixed strut is adapted to the arc-shaped groove.

5. The exhaust diffuser according to claim 4, characterized in that, The angle by which the rotating strut can rotate about the first axial direction is less than or equal to 120 degrees.

6. The exhaust diffuser according to claim 5, characterized in that, One end of the fixed strut adjacent to the rotating strut is connected to the rotating strut through a smooth curved surface transition.

7. The exhaust diffuser according to claim 6, characterized in that, In a plane parallel to the axial direction of the rotor shaft end, the cross-sectional profile of the fixed strut is arc-shaped.

8. The exhaust diffuser according to any one of claims 1-7, characterized in that, The fixed strut has a chamber, and the chamber extends in a direction orthogonal to the axial direction of the rotor shaft end.

9. A turbine component, characterized in that, The turbine assembly includes a turbine body and a diffuser, the diffuser is connected to the end of the turbine body, and the diffuser is the exhaust diffuser according to any one of claims 1-8.

10. A gas turbine, characterized in that, The gas turbine includes the turbine assembly according to claim 9.

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