End cover assembly for gas turbine and gas turbine

Abstract

The present invention provides an end cover assembly for a gas turbine and a gas turbine. The end cover assembly comprises an end cover body and an extension section. The extension section is disposed at the rear end of the end cover body and is coaxial with the end cover body. The radial dimension of the extension section gradually decreases as it moves away from the end cover body. The extension section has a cavity, and an opening communicating with the cavity is provided at one end of the extension section distal from the end cover body. The end cover assembly for a gas turbine according to the present invention can reduce the area affected by the gas turbine wake, reduce total pressure loss, and improve the static pressure recovery coefficient.

Description

Technical Field

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

[0002] The exhaust gas from the gas turbine will form a violently separated wake zone at the turbine outlet. The gas flow in the wake zone will cause flow loss and increase the unevenness of the flow field. In the related art, a cover plate or an extension section with a conical surface is installed at the rear end of the gas turbine end cover assembly. However, due to the complex flow in the wake zone, the cover plate or extension section in the related art has poor guiding effect, which increases the total pressure loss and reduces the static pressure recovery coefficient. Summary of the Invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides an end cover assembly for a gas turbine, which can reduce the gas turbine wake influence area, reduce the total pressure loss, and improve the static pressure recovery coefficient.

[0005] An embodiment of the present invention provides a gas turbine having the advantages of a small wake influence area, low total pressure loss, and a high static pressure recovery coefficient.

[0006] An end cover assembly for a gas turbine according to an embodiment of the present invention includes: an end cover body; an extension section, wherein the extension section is arranged at the tail end of the end cover body, the extension section is coaxially arranged with the end cover body, the radial dimension of the extension section gradually decreases in a direction away from the end cover body, the extension section has a cavity, and an end of the extension section away from the end cover body is provided with an opening connected to the cavity.

[0007] The end cover assembly for a gas turbine according to an embodiment of the present invention is provided with a cavity and an opening, which provides a circulation space for the gas turbine wake, thereby reducing the area affected by the gas turbine wake, reducing the total pressure loss, and improving the static pressure recovery coefficient.

[0008] In some embodiments, the outer circumferential surface of the extension section is an arc-shaped surface, and the outer circumferential surface of the extension section is tangent to the outer circumferential surface of the end cover body.

[0009] In some embodiments, the cavity is cylindrical and is coaxially arranged with the end cover body.

[0010] In some embodiments, a radial dimension of the cavity is equal to a radial dimension of the opening, and the opening is coaxially arranged with the cavity.

[0011] In some embodiments, the extension section includes a connecting end surface, and the connecting end surface connects the outer peripheral surface of the extension section and the inner wall surface of the cavity.

[0012] In some embodiments, the normal line of the connecting end surface is parallel to the extension direction of the axis of the end cover body.

[0013] In some embodiments, the connecting end surface is a convex arc surface.

[0014] In some embodiments, the extension section is integrally formed with the end cap body.

[0015] A gas turbine according to an embodiment of the present invention includes an end cover assembly according to any one of the above embodiments.

[0016] In some embodiments, the gas turbine further includes an exhaust diffuser, which is arranged around the end cover assembly, and the exhaust diffuser includes a first exhaust section and a second exhaust section, the first exhaust section is located upstream of the second exhaust section, and the extension section is located at the junction of the first exhaust section and the second exhaust section. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of an end cover assembly for a gas turbine according to an embodiment of the present invention.

[0018] Figure 2 It is a schematic structural diagram of an end cover assembly for a gas turbine according to another embodiment of the present invention.

[0019] Figure 3 It is a structural schematic diagram of an extension section of an end cover assembly for a gas turbine according to an embodiment of the present invention.

[0020] Figure 4 Schematic diagram of exhaust gas flow of a gas turbine according to an embodiment of the present invention.

[0021] Figure 5 It is a schematic diagram of the exhaust flow of a gas turbine in the related art.

[0022] Figure 6 Schematic diagram of the structure of a gas turbine according to an embodiment of the present invention.

[0023] Reference numerals:

[0024] End cap assembly 1; end cap body 11; extension section 12; cavity 121; opening 122; connecting end surface 123;

[0025] Exhaust diffuser 2; first exhaust section 21; second exhaust section 22. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0027] like Figure 1-Figure 3 As shown, an end cover assembly 1 for a gas turbine according to an embodiment of the present invention includes an end cover body 11 and an extension section 12 .

[0028] The extension section 12 is arranged at the tail end of the end cover body 11. The extension section 12 is coaxially arranged with the end cover body 11. The radial dimension of the extension section 12 gradually decreases in the direction away from the end cover body 11. The extension section 12 has a cavity 121. The end of the extension section 12 away from the end cover body 11 is provided with an opening 122 connected to the cavity 121.

[0029] Specifically, if Figure 1 As shown, one end of the end cover body 11 (i.e., the left end) is connected to the gas turbine rotor shaft, for example, the compressor output shaft, while the other end of the end cover body 11 (i.e., the right end) is connected to the extension section 12. The extension section 12 is coaxially arranged with the end cover body 11 to ensure that rotation of the end cover body 11 drives the coaxial rotation of the extension section 12. The right end of the extension section 12 is provided with an opening 122, which is connected to the cavity 121.

[0030] It can be understood that the radial dimension of the extension section 12 gradually decreases in the direction away from the end cover body 11, which can facilitate the discharge of gas from the gas turbine, and the extension section 12 has a cavity 121, which can provide a larger circulation space for the gas discharged from the gas turbine, thereby reducing the influence area of ​​the gas turbine wake, reducing the total pressure loss, and improving the static pressure recovery coefficient.

[0031] The inventors discovered that Figure 5 As shown, the exhaust area at the rear end of the end cover assembly of the gas turbine in the related art is affected by the gas flow rate, resulting in a larger wake impact area, which increases the total pressure loss and reduces the static pressure recovery coefficient. Figure 4 As shown, the exhaust area at the rear end of the end cover assembly of the gas turbine in an embodiment of the present invention has a cavity and an opening set in the extension section, so the wake influence area is reduced along the circumferential and radial directions of the extension section, thereby reducing the total pressure loss and improving the pressure drop recovery coefficient.

[0032] In addition, if Figure 4 As shown, the flow velocity distribution in the exhaust region of the gas turbine of the embodiment of the present invention is more uniform, and the cavity 121 and the opening 122 provided on the extension section 12 can also reduce the central dead zone.

[0033] Therefore, the configuration of the end cover assembly 1 for a gas turbine according to the embodiment of the present invention can reduce the gas turbine wake influence area, reduce the total pressure loss, and improve the static pressure recovery coefficient.

[0034] In some embodiments, the outer circumference of the extension section 12 is an arc-shaped surface, and the outer circumference of the extension section 12 is tangent to the outer circumference of the end cover body 11 .

[0035] Specifically, if Figure 1 As shown, the outer circumference of the extension section 12 is a convex arc surface, and the radial dimension of the extension section 12 gradually decreases from left to right. The outer circumference of the extension section 12 is tangent to the outer circumference of the end cover body 11, thereby achieving a diversion effect on the discharged gas.

[0036] In some embodiments, the cavity 121 is cylindrical, and the cavity 121 is coaxially arranged with the end cover body 11 .

[0037] Specifically, if Figure 1 As shown, the cavity 121 is cylindrical, and the cavity 121 is coaxially arranged with the end cover body 11 to make the overall structure of the extension section 12 more uniform, so that the extension section 12 is more stable when rotating with the main section.

[0038] Of course, the cavity 121 can also be in other shapes, such as Figure 1 As shown, the cavity 121 of the extension section 12 provides an annular flow space for the wake of the gas turbine, that is, the cavity 121 can be conical (the radial dimension of the conical cavity 121 gradually increases from left to right) or other shapes.

[0039] In some embodiments, the radial dimension of the cavity 121 is equal to the radial dimension of the opening 122 , and the opening 122 and the cavity 121 are coaxially disposed.

[0040] Specifically, if Figure 1 As shown, a cavity 121 is provided on the extension section 12 , and the cavity 121 is communicated with the outside through an opening 122 . The radial dimension of the cavity 121 is equal to the radial dimension of the opening 122 and they are coaxially arranged, so as to facilitate processing.

[0041] It is understandable that a cavity 121 may be provided on the right end face of the extension section 12 , and an opening 122 is formed at the right end of the cavity 121 , that is, the cavity 121 and the opening 122 may be formed at one time.

[0042] In some embodiments, the extension section 12 includes a connecting end surface 123 , and the connecting end surface 123 connects the outer peripheral surface of the extension section 12 and the inner wall surface of the cavity 121 .

[0043] It is understandable that if Figure 1As shown, the size of the connecting end surface 123 is related to the size of the opening 122 , that is, as the size of the connecting end surface 123 increases, the size of the opening 122 decreases accordingly.

[0044] It should be noted that the outer peripheral surface of the extension section 12 is arc-shaped, which can guide the gas discharged from the gas turbine, and the gas flow will change near the connecting end surface 123, that is, part of the gas flow tends to flow into the cavity 121. In other words, the cavity 121 and the opening 122 are provided on the extension section 12 to provide a circulation space for the gas turbine wake. Therefore, the size of the cavity 121 and the size of the opening 122 can be changed for different gas turbines, thereby providing a circulation space for the wake.

[0045] Alternatively, as Figure 1 As shown, the normal line of the connecting end face 123 is parallel to the axis extension direction of the end cover body 11. It can be understood that, as Figure 1 As shown, the connecting end surface 123 is a plane, and the normal line of the connecting end surface 123 is parallel to the left-right direction.

[0046] Preferably, the connecting end surface 123 is a convex arc surface. Figure 2 As shown, the connecting end surface 123 is a curved surface that convexly projects to the right. Furthermore, the outer circumference of the connecting end surface 123 is tangent to the outer circumference of the extension section 12. In other words, the convex curved surface of the connecting end surface 123 further enhances the flow-guiding effect of the extension section 12, thereby allowing a portion of the exhaust gas from the gas turbine to be introduced into the cavity.

[0047] In some embodiments, the extension section 12 is integrally formed with the end cap body 11. It will be appreciated that integrally forming the extension section 12 with the end cap body 11 can simplify the manufacturing and installation process of the extension section 12 and can also increase the strength of the connection between the extension section 12 and the end cap body 11. Furthermore, integrally forming the extension section 12 with the end cap body 11 can ensure a smooth connection between the outer circumference of the extension section 12 and the outer circumference of the end cap body 11, thereby achieving a stable diversion effect.

[0048] The gas turbine according to the embodiment of the present invention includes the end cover assembly 1 according to any one of the above embodiments.

[0049] Specifically, if Figure 6 As shown, the end cover assembly 1 of the gas turbine in the embodiment of the present invention is provided with a cavity 121 and an opening 122, which provides a circulation space for the gas turbine wake, thereby reducing the influence area of ​​the gas turbine wake, reducing the total pressure loss, and improving the static pressure recovery coefficient.

[0050] In some embodiments, the gas turbine also includes an exhaust diffuser 2, which is arranged around the end cover assembly 1. The exhaust diffuser 2 includes a first exhaust section 21 and a second exhaust section 22. The first exhaust section 21 is located upstream of the second exhaust section 22, and the extension section 12 is located at the junction of the first exhaust section 21 and the second exhaust section 22.

[0051] Specifically, if Figure 6 As shown, the first exhaust section 21 is located on the left side of the second exhaust section 22. The second exhaust section 22 is conical, that is, the radial dimension of the second exhaust section 22 gradually increases from left to right to improve the diffusion effect.

[0052] It can be understood that the gas exhausted by the gas turbine in the embodiment of the present invention will form a wake area at the rear end of the end cover assembly 1. A cavity 121 and an opening 122 are provided on the extension section 12 of the end cover assembly 1, which provide a circulation space for the gas turbine wake, thereby reducing the area affected by the gas turbine wake, reducing the total pressure loss, and improving the static pressure recovery coefficient.

[0053] In addition, the end cover assembly 1 of the gas turbine according to the embodiment of the present invention further makes the velocity distribution of the flow field in the exhaust diffuser 2 more uniform, thereby further improving the pressure diffusion effect of the exhaust diffuser 2.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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 understood as limiting the present invention.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0056] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0057] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0058] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0059] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those skilled in the art are all within the scope of protection of the present invention.

Claims

1. An end cover assembly for a gas turbine, characterized in that: include: End cap body; an extension section, the extension section being provided at the rear end of the end cover body, the extension section being coaxially arranged with the end cover body, the radial dimension of the extension section gradually decreasing in a direction away from the end cover body, the extension section having a cavity, and an end of the extension section away from the end cover body being provided with an opening communicating with the cavity; The outer circumferential surface of the extension section is an arc-shaped surface, and the outer circumferential surface of the extension section is tangent to the outer circumferential surface of the end cover body.

2. The end cover assembly for a gas turbine according to claim 1, wherein: The cavity is cylindrical and is coaxially arranged with the end cover body.

3. The end cover assembly for a gas turbine according to claim 2, wherein: The radial size of the cavity is equal to the radial size of the opening, and the opening and the cavity are coaxially arranged.

4. The end cover assembly for a gas turbine according to claim 1, wherein: The extension section includes a connecting end surface, and the connecting end surface connects the outer peripheral surface of the extension section and the inner wall surface of the cavity.

5. The end cover assembly for a gas turbine according to claim 4, wherein: The normal line of the connecting end surface is parallel to the extending direction of the axis of the end cover body.

6. The end cover assembly for a gas turbine according to claim 4, wherein: The connecting end surface is a convex arc surface.

7. The end cover assembly for a gas turbine according to any one of claims 1 to 6, characterized in that: The extension section and the end cover body are integrally formed.

8. A gas turbine, characterized in that: It comprises an end cover assembly, and the end cover assembly is the end cover assembly according to any one of claims 1-7.

9. The gas turbine according to claim 8, characterized in that The gas turbine also includes an exhaust diffuser, which is arranged around the end cover assembly. The exhaust diffuser includes a first exhaust section and a second exhaust section. The first exhaust section is located upstream of the second exhaust section, and the extension section is located at the junction of the first exhaust section and the second exhaust section.

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