A gas turbine and a casing cooling structure thereof

Abstract

This application discloses a gas turbine and its casing cooling structure, relating to the field of gas turbine technology. The casing cooling structure includes: an outer casing and an inner casing; the centerlines of the outer casing and the inner casing coincide, and the inner casing is disposed inside the outer casing; multiple casing protrusions; each casing protrusion is disposed between the outer casing and the inner casing, and the protrusions are distributed circumferentially around the inner casing; adjacent casing protrusions form cooling channels with the inner wall surface of the outer casing and the outer wall surface of the inner casing. This application, by setting multiple casing protrusions between the coaxially arranged outer and inner casings, utilizes the direct enclosure of adjacent casing protrusions with the inner and outer walls of the outer and inner casings to form cooling channels, completely replacing the traditional complex serpentine, multi-hole cooling channel design inside the inner casing.

Description

Technical Field

[0001] This application relates to the field of gas turbine technology, specifically to a gas turbine and its casing cooling structure. Background Technology

[0002] As a highly efficient power plant, the casing of a gas turbine operates under harsh conditions of high temperature and high pressure for extended periods. The casing cooling structure is a core component ensuring the safety and reliability of the gas turbine casing. However, existing casing cooling structures still present several problems that urgently need to be addressed. For example, most current mainstream casing cooling structures employ complex cooling channels (serpentine channels, porous cooling structures, etc.) machined inside the inner casing. To accommodate these cooling channels, the inner casing must be designed with thicker walls, which not only significantly increases material usage but also leads to uneven thermal stress distribution, affecting the inner casing's ability to coordinate deformation under high-temperature conditions. Furthermore, the machining of these complex internal channels requires extremely high precision, typically necessitating special processing techniques such as precision casting or deep-hole drilling. This process is difficult, has a long production cycle, and results in a low yield rate, directly increasing the manufacturing cost of the gas turbine casing. Summary of the Invention

[0003] The purpose of this application is to provide a gas turbine and its casing cooling structure to solve the technical problems of complex and high manufacturing cost of existing gas turbine casing cooling structures.

[0004] To achieve the above objectives, this application provides the following technical solution:

[0005] Firstly, this application proposes a casing cooling structure. The casing cooling structure includes: An outer casing and an inner casing; the centerlines of the outer casing and the inner casing coincide, and the inner casing is disposed inside the outer casing; Multiple casing protrusions; each casing protrusion is disposed between the outer casing and the inner casing, and each casing protrusion is distributed circumferentially around the inner casing; two adjacent casing protrusions form cooling channels with the inner wall surface of the outer casing and the outer wall surface of the inner casing.

[0006] As a specific solution in this application, each housing protrusion and the inner housing are integrally formed. The inner wall of the outer housing is provided with a first limiting groove and a limiting bolt corresponding to each housing protrusion. Each first limiting groove is used to limit the relative displacement of the outer housing and the inner housing in the circumferential and radial directions. Each limiting bolt is used to limit the relative displacement of the outer housing and the inner housing in the axial direction.

[0007] As a specific embodiment of the technical solution in this application, both the outer casing and the inner casing are split-type casings; the cross-section of the outer casing is C-shaped, so that the interior of the outer casing forms an annular cavity with a T-shaped cross-section; the inner casing is disposed in the annular cavity; a limiting module is also provided between the outer casing and the inner casing, the limiting module being used at least to limit the circumferential relative displacement between the outer casing and the inner casing.

[0008] As a specific solution in this application, the limiting module includes: A second limiting groove is provided in the inner casing; A limiting hole is provided in the outer casing; the limiting hole corresponds to the second limiting groove, and the inner diameter of the limiting hole is larger than the inner diameter of the second limiting groove; The limiting pin is both in an interference fit with the second limiting groove and in an interference fit with the limiting hole.

[0009] As a specific solution in this application, the limiting module includes: A second limiting groove is provided in the inner casing; A third limiting groove is disposed in the outer casing; the third limiting groove corresponds to the second limiting groove; The limiting post is adapted to the second limiting groove and the third limiting groove respectively; the first length is greater than the first depth, the first length is the length of the limiting post along the first direction; the first depth is the depth of the third limiting groove along the first direction; the first direction is parallel to the axial direction of the inner casing. A first elastic element is disposed between the second limiting groove and the limiting post, for generating a counterforce parallel to the first direction between the limiting post and the third limiting groove; and the sum of the first length and the second length is less than or equal to the second depth; the second length is the minimum length formed by the first elastic element after being compressed along the first direction within the elastic deformation range; the second depth is the depth of the second limiting groove along the first direction.

[0010] As a specific solution in this application, it also includes an adjustment module, which is disposed in the outer casing or the inner casing and is used to adjust the opening of the cooling channel.

[0011] As a specific solution in this application, the adjustment module includes an adjustment ring, which is threadedly connected to the outer casing or the inner casing by a plurality of fastening bolts.

[0012] As a specific embodiment of the technical solution in this application, the adjusting ring is elastic; and the adjusting ring includes a curved section and a horizontal section, so that the radial width of the adjusting ring is positively correlated with the axial compressive force applied to the adjusting ring.

[0013] As a specific embodiment of the technical solution in this application, the cross-section of the adjusting ring is shaped like the number 7, and the bolt shank of each fastening bolt moves through the adjusting ring; the casing cooling structure also includes a second elastic element corresponding to each fastening bolt; each second elastic element is located between the adjusting ring and the casing, and each second elastic element is used to apply an elastic force along a second direction to the adjusting ring; the second direction is parallel to the axis of the fastening bolt corresponding to the second elastic element, and points from the bolt shank of the fastening bolt to the bolt head.

[0014] Secondly, this application proposes a gas turbine. The gas turbine includes a casing cooling structure as described in any one of the first aspects.

[0015] Compared with the prior art, the beneficial effects of this application are: This application utilizes multiple casing protrusions between the coaxially arranged outer and inner casings to form cooling channels. These protrusions, along with the inner and outer walls of the outer and inner casings, directly enclose the cooling channels, completely replacing the traditional complex serpentine, multi-hole cooling channel design within the inner casing. This structure eliminates the need to thicken the inner casing wall, significantly reducing material usage. It also avoids uneven thermal stress distribution caused by internal flow channels, improving the inner casing's deformation tolerance under high-temperature conditions. In terms of manufacturing, its simple overall structure eliminates the need for precision casting, deep-hole drilling, and other special processes, effectively reducing processing difficulty, shortening the production cycle, and increasing yield, fundamentally lowering the manufacturing cost of the gas turbine casing cooling structure. Attached Figure Description

[0016] Figure 1 This is a front view schematic diagram of a casing cooling structure proposed in an embodiment of this application (bolts are not shown). Figure 2 for Figure 1 A three-dimensional schematic diagram of the cooling structure of the middle casing in one direction; Figure 3 for Figure 1 A three-dimensional schematic diagram of the cooling structure of the middle casing from another direction; Figure 4 for Figure 1 A partial cross-sectional view of the cooling structure of the middle casing along line AA; Figure 5 for Figure 1 A partial cross-sectional view of the cooling structure of the middle casing along line BB; Figure 6 A partial embodiment of another casing cooling structure proposed in this application. Figure 1 Schematic diagram of the cross section of the middle BB line; Figure 7 A partial embodiment of another casing cooling structure proposed in this application Figure 1 Schematic diagram of the cross section of the middle BB line; Figure 8 Another partial structure for casing cooling proposed in this application embodiment is based on... Figure 1 Schematic diagram of the cross section of the middle BB line; Figure 9 This application provides a partial embodiment of yet another casing cooling structure. Figure 1 A cross-sectional view of the orientation indicated by the middle BB line; Figure 10 for Figure 9 An enlarged schematic diagram of a structure in section D; Figure 11 for Figure 9 Another enlarged schematic diagram of the structure of part D in the middle.

[0017] In the diagram: 1. Outer casing; 2. Inner casing; 3. Casing protrusion; 4. Cooling channel; 5. First limiting groove; 61. Limiting bolt; 62. Second limiting groove; 63. Third limiting groove; 64. First elastic element; 65. Limiting post; 66. Disassembly hole; 67. Limiting hole; 68. Limiting pin; 71. Adjusting ring; 711. Bending section; 712. Horizontal section; 72. Fastening bolt; 73. Second elastic element. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that in the description of this application, the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] Furthermore, it should be understood that, for ease of description, the dimensions of the various components shown in the accompanying drawings are not drawn to actual scale; for example, the thickness or width of some layers may be exaggerated relative to other layers.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined or described in one figure, it will not need to be discussed or described in detail in the description of the subsequent figures.

[0022] To address the technical problems of complex and high-cost manufacturing of existing gas turbine casing cooling structures as mentioned in the background art, this application proposes an embodiment of a casing cooling structure. Specifically, the casing cooling structure includes an outer casing 1, an inner casing 2, and multiple casing protrusions 3. For example... Figure 1 and Figure 2 As shown, the centerlines of the outer casing 1 and the inner casing 2 coincide, and the inner casing 2 is located inside the outer casing 1. Each casing protrusion 3 is located between the outer casing 1 and the inner casing 2, and the protrusions 3 are distributed circumferentially around the inner casing 2. Two adjacent casing protrusions 3 form cooling channels 4 with the inner wall surface of the outer casing 1 and the outer wall surface of the inner casing 2.

[0023] This embodiment replaces the traditional complex serpentine, multi-hole cooling channel design inside the inner casing by setting multiple casing protrusions 3 between the outer casing 1 and the inner casing 2, utilizing adjacent casing protrusions 3 to form a cooling channel 4 enclosed by the outer casing 1 and the inner casing 2. This casing cooling structure eliminates the need to thicken the inner casing wall, reducing material usage and avoiding uneven thermal stress distribution caused by internal cooling channels, thus improving the deformation coordination of the inner casing under high-temperature conditions. In terms of manufacturing, the casing cooling structure formed by the outer casing 1, inner casing 2, and multiple casing protrusions 3 is relatively simple, eliminating the need for special processes such as precision casting and deep hole drilling. This reduces manufacturing difficulty, shortens the production cycle, and improves yield, fundamentally reducing the manufacturing cost of the casing cooling structure. During use, the cooling gas can... Figures 5 to 9 As shown in direction C, the cooling channel 4 formed between the outer casing 1 and the inner casing 2 flows.

[0024] In the embodiments of this application, there are no restrictions on the connection methods between the casing protrusion 3 and the outer casing 1 and the inner casing 2, respectively. For example, one end of the casing protrusion 3 can be fixedly connected to the outer casing 1, and the other end can be fixedly connected to the inner casing 2. To facilitate the disassembly and assembly of the outer casing 1 and the inner casing 2, in one embodiment of this application, such as Figure 2 , Figure 3 and Figure 4As shown, each casing protrusion 3 and the inner casing 2 are integrally formed. The inner wall of the outer casing 1 is provided with first limiting grooves 5 and limiting bolts 61 corresponding to each casing protrusion 3. The first limiting grooves 5 cooperate with each casing protrusion 3 to limit the relative circumferential and radial displacement between the outer casing 1 and the inner casing 2. The limiting bolts 61 limit the relative axial displacement between the outer casing 1 and the inner casing 2.

[0025] In use, if it is necessary to assemble the outer casing 1 and the inner casing 2, firstly, the inner casing 2, which is integrally formed with casing protrusions 3, is hoisted to the axial installation position of the outer casing 1. The posture of the inner casing 2 is adjusted so that its axis is completely aligned with the axis of the outer casing 1. Then, the inner casing 2 is slowly pushed axially into the outer casing 1, so that each casing protrusion 3 distributed circumferentially on the outer wall of the inner casing 2 is inserted one by one into the first limiting groove 5 on the inner wall of the outer casing 1. At this time, the radial groove wall of the first limiting groove 5 is tightly fitted with the radial side of the casing protrusion 3, and the circumferential groove wall is tightly fitted with the circumferential side of the casing protrusion 3. The outer casing 1 and the inner casing 2 are fitted together, thereby simultaneously restricting the radial movement and circumferential relative rotation between them, completing the initial positioning of the two. Finally, each limiting bolt 61 is inserted axially into the pre-set bolt holes on the outer casing 1 from the outer wall side of the outer casing 1, and screwed into the threaded holes opened at the ends of the corresponding casing protrusions 3. All limiting bolts 61 are tightened in sequence according to the specified torque, so that the bolt heads of the limiting bolts 61 press against the outer wall surface of the outer casing 1. The casing protrusions 3 and the outer casing 1 are axially locked through the threaded connection, completely restricting the axial relative displacement between the two, thus completing the overall assembly of the outer casing 1 and the inner casing 2. If it is necessary to disassemble the outer casing 1 and the inner casing 2, simply reverse the above steps: first, loosen and remove all the limiting bolts 61 in diagonal order to release the axial limit of the outer casing 1 and the inner casing 2; then, slowly pull out the inner casing 2 along the axial direction so that each casing protrusion 3 completely disengages from the corresponding first limiting groove 5, thereby realizing the separation of the outer casing 1 and the inner casing 2, which facilitates subsequent component inspection, replacement of worn parts and maintenance.

[0026] Of course, in other embodiments of this application, each housing protrusion 3 can also form an integral structure with the outer housing 1, with the first limiting groove 5 disposed on the outer wall surface of the inner housing 2, and the first limiting groove 5 corresponding one-to-one with each housing protrusion 3. That is to say, in this application, the integral molding method of the housing protrusion 3 with the outer housing 1 or the inner housing 2 can be flexibly selected according to actual assembly requirements and processing technology to adapt to different production scenarios, which will not be elaborated here.

[0027] It is important to note that gas turbines operate under harsh conditions of high temperature and high pressure for extended periods, making components such as hot-end blades susceptible to creep, cracking, and other damage. Having on-site cylinder disassembly and maintenance capabilities can significantly shorten repair cycles and avoid high return-to-factory costs and prolonged downtime. Therefore, current technology generally uses a split-type casing for the outer and inner casings. Specifically, a split-type casing refers to a casing structure where the overall annular casing is symmetrically divided into an upper and lower half along the axial midline of the gas turbine. These two halves are fastened together at the midline using circumferentially distributed flanges and connecting bolts, forming a complete, closed annular cavity. For the hot-end casing of a gas turbine, the core advantage of an axially split, two-section design is that during maintenance, only the connecting bolts at the split surface need to be removed to lift and separate the upper casing. This eliminates the need for complete disassembly of the gas turbine rotor, bearing housings, and upstream and downstream intake, exhaust, and fuel pipelines. It allows direct exposure of core hot-end components inside the casing, such as the moving blades, stationary blades, sealing rings, and combustion chamber, enabling rapid on-site inspection, troubleshooting, and replacement of vulnerable parts. However, traditional split-section casings require numerous bolts to connect and position the outer and inner casings, resulting in a large number of parts, high manufacturing costs, and a cumbersome assembly and disassembly process, impacting maintenance efficiency. To reduce the number of parts required for connecting the inner and outer casings in a split-section design, in one embodiment of this application, both the outer casing 1 and the inner casing 2 are split-section casings. Figure 9 As shown, the outer casing 1 has a C-shaped cross-section, creating a T-shaped annular cavity inside. The inner casing 2 is disposed within this annular cavity. A limiting module is also provided between the outer casing 1 and the inner casing 2, which at least limits the circumferential relative displacement between them.

[0028] This embodiment employs a split outer casing with a C-shaped cross-section, forming a T-shaped annular cavity inside the outer casing and nesting it with an inner casing, achieving axial and radial positioning of the outer and inner casings. A positioning module further enables circumferential positioning and limiting of the outer and inner casings. Eliminating the need for numerous bolts for connecting and positioning the outer and inner casings reduces the number of parts and assembly steps, lowering manufacturing costs. Furthermore, during maintenance, simply releasing the positioning module allows for rapid separation of the outer and inner casings, improving work efficiency and shortening gas turbine shutdown and maintenance cycles.

[0029] In this embodiment, the limiting module is not subject to many restrictions, as long as it can limit the circumferential relative displacement between the outer casing 1 and the inner casing 2. For example, in one embodiment of this application, the limiting module includes a second limiting groove 62, a limiting hole 67, and a limiting pin 68. Figure 10As shown, the second limiting groove 62 is disposed in the inner casing 2, and the limiting hole 67 is disposed in the outer casing 1. The limiting hole 67 corresponds to the second limiting groove 62, and the inner diameter of the limiting hole 67 is larger than the inner diameter of the second limiting groove 62. The limiting pin 68 is in interference fit with both the second limiting groove 62 and the limiting hole 67.

[0030] In use, if it is necessary to achieve circumferential limiting of the outer casing 1 and the inner casing 2, the inner casing 2 is first embedded into the annular cavity of the outer casing 1, and the second limiting groove 62 of the inner casing 2 is precisely aligned with the limiting hole 67 of the outer casing 1. Then, the limiting pin 68 is inserted from the limiting hole 67, so that it forms an interference fit with the second limiting groove 62 and the limiting hole 67 at the same time, which can limit the relative circumferential displacement of the outer casing 1 and the inner casing 2 and complete the circumferential limiting.

[0031] In this embodiment, the correspondence between the limiting hole 67 and the second limiting groove 62 means that when the inner casing 2 is fully embedded in the T-shaped annular cavity of the outer casing 1, and the center lines of the outer casing 1 and the inner casing 2 coincide and their axial and radial positions are precisely aligned, the center line of the limiting hole 67 and the center line of the second limiting groove 62 are completely collinear, so as to ensure that the limiting pin 68 can be smoothly inserted into the limiting hole 67 and the second limiting groove 62.

[0032] It is important to note that if the limiting pin 68 is both interference-fitted with the second limiting groove 62 and the limiting hole 67, during the long-term high-temperature operation of the gas turbine, the outer casing 1 and the inner casing 2 may undergo different degrees of thermal expansion deformation due to the operating temperature gradient. The interference-fitted limiting pin 68 will be firmly stuck by the compressive force generated by the thermal deformation. This may not only prevent the limiting pin 68 from being pulled out normally during casing maintenance, but also cause permanent structural damage such as scratches and cracks on the inner wall of the second limiting groove 62 or the limiting hole 67 if forcibly disassembled. At the same time, the rigid interference fit will completely restrict the free thermal deformation of the outer casing 1 and the inner casing 2, generating additional thermal stress that cannot be released inside the casing (i.e., the outer casing 1 or the inner casing 2). Under long-term alternating loads, this will accelerate the initiation and propagation of fatigue cracks in the casing and reduce the service life of the casing. To overcome the inherent defects of rigid interference limiting, in one embodiment of this application, the limiting module may include a second limiting groove 62, a third limiting groove 63, a limiting post 65, and a first elastic element 64. Wherein, as... Figure 11As shown, a second limiting groove 62 is disposed in the inner casing 2. A third limiting groove 63 is disposed in the outer casing 1, and the third limiting groove 63 corresponds to the second limiting groove 62. A first elastic member 64 is disposed between the second limiting groove 62 and the limiting post 65, for generating a contact force parallel to a first direction between the limiting post 65 and the third limiting groove 63. A first length is greater than a first depth, and the sum of the first length and the second length is less than or equal to a second depth. The first length is the length of the limiting post 65 along the first direction. The first depth is the depth of the third limiting groove 63 along the first direction. The second length is the minimum length formed by the first elastic member 64 after being compressed along the first direction within its elastic deformation range. The second depth is the depth of the second limiting groove 62 along the first direction. The first direction is parallel to the axial direction of the inner casing 2.

[0033] In use, if circumferential positioning of the outer casing 1 and the inner casing 2 is required, the limiting post 65 is pressed inward, compressing the first elastic element 64 so that the limiting post 65 is fully retracted into the second limiting groove 62, thereby facilitating the embedding of the inner casing 2 into the T-shaped annular cavity of the outer casing 1; further, the relative position between the outer casing 1 and the inner casing 2 is adjusted until the second limiting groove 62 and the third limiting groove 63 are precisely aligned; further, the first elastic element 64 rebounds and pushes the limiting post 65 to engage with the third limiting groove 63 along the axial direction (i.e., the first direction), thereby enabling the limiting post 65 to achieve circumferential positioning of the outer casing 1 and the inner casing 2.

[0034] In this embodiment, the third limiting groove 63 corresponds to the second limiting groove 62. When the inner casing 2 is fully embedded in the T-shaped annular cavity of the outer casing 1, and the center lines of the outer casing 1 and the inner casing 2 coincide and their axial and radial positions are precisely aligned, the center lines of the second limiting groove 62 and the third limiting groove 63 are collinear. This ensures that the limiting post 65 can smoothly enter the third limiting groove 63 from the second limiting groove 62 under the rebound action of the first elastic element 64, thus completing the circumferential limiting of the outer casing 1 and the inner casing 2.

[0035] In this embodiment, the matching of the limiting post 65 with the second limiting groove 62 and the third limiting groove 63 means that the outer diameter of the limiting post 65 matches the inner diameter of the second limiting groove 62 and the third limiting groove 63. The limiting post 65 can slide smoothly along the axial direction in the second limiting groove 62 without radial loosening. After the limiting post 65 is inserted into the third limiting groove 63, the outer wall of the post is tightly fitted with the inner wall of the groove, with no circumferential gap or only a small gap (e.g., a gap of 50 mil or 100 mil). This can accurately limit the relative circumferential displacement between the outer casing 1 and the inner casing 2, and will not hinder the slight axial and radial deformation of the outer casing 1 and the inner casing 2 caused by thermal expansion, thus taking into account both the limiting stability and the thermal deformation compensation requirements.

[0036] In this embodiment, no restrictions are placed on the shape and structure of the first elastic element 64 (the same applies to the second elastic element 73 described below, which will not be elaborated upon further), as long as the first elastic element 64 can generate a counterforce parallel to the first direction between the limiting post 65 and the third limiting groove 63. For example, the first elastic element 64 can be an elastic metal sheet, or as... Figure 11 The image shows a spring.

[0037] To facilitate the release of the circumferential limiting effect of the limiting post 65 between the outer casing 1 and the inner casing 2, in one embodiment of this application, such as... Figure 11 As shown, the outer casing 1 is also provided with a disassembly hole 66 corresponding to the limiting post 65. The inner diameter of the disassembly hole 66 is smaller than the inner diameter of the third limiting groove 63.

[0038] In use, if it is necessary to release the circumferential limit between the outer casing 1 and the inner casing 2, a slender tool (e.g., a copper rod or a plastic rod) is inserted into the disassembly hole 66 of the outer casing 1 and pushed inward to push the limiting post 65. The first elastic element 64 is compressed so that the limiting post 65 is completely retracted into the second limiting groove 62 of the inner casing 2, releasing the engagement state between the limiting post 65 and the third limiting groove 63. At this time, the circumferential limit between the outer casing 1 and the inner casing 2 is released, and the outer casing 1 and the inner casing 2 can be separated smoothly to complete the disassembly operation.

[0039] In this embodiment, the correspondence between the disassembly hole 66 and the limiting post 65 means that the disassembly hole 66 is directly opposite the end face of the limiting post 65 facing the disassembly hole 66, ensuring that the slender tool can accurately push the limiting post 65 through the disassembly hole 66 so that the limiting post 65 can smoothly compress the first elastic member 64 to release the limitation.

[0040] It is important to understand that the limiting module proposed in this embodiment does not require the limiting post to form an interference fit with the outer or inner casing. The elastic preload generated by the first elastic element can achieve stable and reliable circumferential limiting between the outer and inner casings. At the same time, the non-interference limiting can reserve sufficient margin for the axial and radial thermal deformation of the outer and inner casings, effectively releasing thermal stress and fundamentally solving the problems of jamming, disassembly difficulties and structural damage caused by rigid interference limiting.

[0041] It is important to note that in existing technologies, once the cooling channel is manufactured, its cooling gas flow rate cannot be adjusted. If the cooling gas flow rate does not match the cooling requirements of the gas turbine, the following problems may occur: If the cooling gas flow rate is greater than the cooling requirements of the gas turbine, excessive cooling gas loss will occur, reducing the gas turbine's main airflow share and lowering its power efficiency and output power. If the cooling gas flow rate is less than the cooling requirements of the gas turbine, the heat accumulated in the components requiring cooling cannot be removed in time, causing these components to exceed their temperature limits. Under prolonged high temperatures, creep, ablation, and other problems may occur, threatening the safe operation of the gas turbine. In order to adjust the cooling gas flow rate entering the cooling channel to match the cooling requirements of the gas turbine, in one embodiment of this application, the casing cooling structure also includes an adjustment module. The adjustment module is located in the outer casing 1 or the inner casing 2 and is used to adjust the opening of the cooling channel 4.

[0042] Of course, in other embodiments of this application, the adjustment module may also be disposed in the cooling channel 4.

[0043] Specifically, the adjustment module can be as follows: Figure 6 As shown, it includes an adjusting ring 71, which is threadedly connected to the outer casing 1 or the inner casing 2 by a plurality of fastening bolts 72.

[0044] When using it, if the cooling air volume needs to be adjusted, change to a different radial width (i.e., such as...). Figure 6 The adjustment ring 71 with the width S shown can be used. It should be clear that if the radial width of the adjustment ring 71 is larger, the opening of the cooling channel 4 inlet is smaller, that is, the cooling air volume is smaller; if the radial width of the adjustment ring 71 is smaller, the opening of the cooling channel 4 inlet is larger, that is, the cooling air volume is larger.

[0045] To eliminate the need for frequent disassembly and replacement of the adjusting ring 71 when adjusting the cooling air volume—that is, to allow different cooling air volumes to be adjusted using the same adjusting ring 71—in one embodiment of this application, the adjusting ring 71 is elastic. And as... Figure 7 As shown, the adjusting ring 71 includes a curved section 711 and a horizontal section 712, such that the radial width of the adjusting ring 71 is positively correlated with the axial compressive force applied to the adjusting ring 71.

[0046] In use, if it is necessary to reduce the cooling air volume, tighten the fastening bolts 72 of the adjusting ring 71 in a diagonal sequence. As the fastening bolts 72 are tightened, the axial compressive force on the adjusting ring 71 gradually increases, and its curved section 711 is axially compressed and elastically deformed radially outward, causing the horizontal section 712 to extend outward synchronously. This increases the overall radial width S of the adjusting ring 71, and the inlet opening of the cooling channel 4 decreases accordingly, ultimately achieving a precise reduction in the cooling air volume. If it is necessary to increase the cooling air volume, loosen the fastening bolts 72 of the adjusting ring 71 in a diagonal sequence. As the fastening bolts 72 are loosened, the axial compressive force on the adjusting ring 71 gradually decreases, and the compressed curved section 711 gradually springs back to its original position under its own elastic force, causing the horizontal section 712 to contract radially inward. This decreases the overall radial width S of the adjusting ring 71, and the inlet opening of the cooling channel 4 increases accordingly, ultimately achieving a precise increase in the cooling air volume.

[0047] In another embodiment of this application, such as Figure 8 As shown, the cross-section of the adjusting ring 71 is shaped like the number 7, and the bolt shank of each fastening bolt 72 moves through the adjusting ring 71. The casing cooling structure also includes a second elastic element 73 corresponding to each fastening bolt 72. Each second elastic element 73 is located between the adjusting ring 71 and the casing, and each second elastic element 73 is used to apply an elastic force to the adjusting ring 71 in a second direction. The second direction is parallel to the axis of the fastening bolt 72 corresponding to the second elastic element 73, and points from the bolt shank of the fastening bolt 72 to the bolt head.

[0048] In use, if it is necessary to reduce the cooling air volume, tighten the fixing bolts 72 of the adjusting ring 71 in a diagonal sequence. As the fixing bolts 72 are tightened, the adjusting ring 71 can overcome the elastic force generated by the second elastic element 73 and move along the axial direction of the inner casing 2 towards the inlet of the cooling channel 4. Since the cross-section of the adjusting ring 71 is shaped like a "7", its radially protruding flange will gradually extend into the inlet area of ​​the cooling channel 4 with the axial displacement. Therefore, the closer the adjusting ring 71 is to the inlet of the cooling channel 4, the smaller the effective flow area of ​​the cooling channel 4, and the cooling air volume is reduced accordingly. If it is necessary to increase the cooling air volume, loosen the fixing bolts 72 of the adjusting ring 71 in a diagonal sequence. As the fixing bolts 72 are loosened, the axial compression of the second elastic element 73 gradually decreases, and its stored elastic potential energy is gradually released. The resulting elastic force pushes the adjusting ring 71 along the axial direction of the inner casing 2 away from the inlet of the cooling channel 4. Since the cross-section of the adjusting ring 71 is shaped like the number 7, its radially protruding flange will gradually exit the inlet area of ​​the cooling channel 4 with the axial displacement, thereby increasing the effective flow area of ​​the cooling channel 4 and ultimately achieving precise adjustment of the cooling air volume.

[0049] In this embodiment, the bolt shank of the fastening bolt 72 movably passes through the adjusting ring 71, meaning that the adjusting ring 71 has a smooth hole rather than a threaded hole. The bolt shank of the fastening bolt 72 can freely pass through this smooth hole, and the bolt head only serves to axially limit the adjusting ring 71; there is no threaded connection between the two. The adjusting ring 71 can slide back and forth along the axis of the bolt shank, thereby achieving continuous adjustment of the axial position under the combined action of the elastic force of the second elastic element 73 and the bolt tightening force.

[0050] The casing cooling structure proposed in this application utilizes circumferentially distributed casing protrusions between the coaxially arranged outer and inner casings. These protrusions, along with the inner and outer walls of the outer and inner casings, directly enclose and form cooling channels, completely replacing the traditional complex serpentine, multi-hole cooling channel design within the inner casing. This structure eliminates the need to thicken the inner casing wall, significantly reducing material usage. It also avoids uneven thermal stress distribution caused by internal flow channels, improving the inner casing's deformation tolerance under high-temperature conditions. In terms of manufacturing, its overall structure is simple, eliminating the need for precision casting, deep-hole drilling, or other special processes. This effectively reduces processing difficulty, shortens the production cycle, and improves yield, fundamentally lowering the manufacturing cost of the gas turbine casing cooling structure.

[0051] Having described the casing cooling structure proposed in the embodiments of this application, the following describes a gas turbine proposed in this application. This gas turbine includes the casing cooling structure described in any of the embodiments above.

[0052] The gas turbine proposed in this application utilizes circumferentially distributed casing protrusions between the coaxially arranged outer and inner casings. These protrusions, along with the inner and outer walls of the outer and inner casings, directly enclose and form cooling channels, completely replacing the traditional complex serpentine, multi-hole cooling channel design within the inner casing. This structure eliminates the need to thicken the inner casing wall, significantly reducing material usage. It also avoids uneven thermal stress distribution caused by internal flow channels, improving the inner casing's deformation tolerance under high-temperature conditions. In terms of manufacturing, its overall structure is simple, eliminating the need for precision casting, deep-hole drilling, or other special processes. This effectively reduces processing difficulty, shortens the production cycle, and improves yield, fundamentally lowering the manufacturing cost of the gas turbine casing cooling structure.

[0053] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A casing cooling structure, characterized in that, include: An outer casing (1) and an inner casing (2); the center lines of the outer casing (1) and the inner casing (2) coincide, and the inner casing (2) is disposed inside the outer casing (1); Multiple casing protrusions (3); each casing protrusion (3) is disposed between the outer casing (1) and the inner casing (2), and each casing protrusion (3) is distributed around the circumference of the inner casing (2); two adjacent casing protrusions (3) form a cooling channel (4) with the inner wall surface of the outer casing (1) and the outer wall surface of the inner casing (2).

2. The casing cooling structure according to claim 1, characterized in that, Each housing protrusion (3) and the inner housing (2) are integral structures. The inner wall of the outer housing (1) is provided with a first limiting groove (5) and a limiting bolt (61) corresponding to each housing protrusion (3). Each first limiting groove (5) is used to limit the relative displacement of the outer housing (1) and the inner housing (2) in the circumferential and radial directions. Each limiting bolt (61) is used to limit the relative displacement of the outer housing (1) and the inner housing (2) in the axial direction.

3. The casing cooling structure according to claim 1, characterized in that, Both the outer casing (1) and the inner casing (2) are split-type casings; the cross-section of the outer casing (1) is C-shaped so that the interior of the outer casing (1) forms an annular cavity with a T-shaped cross-section; the inner casing (2) is disposed in the annular cavity; a limiting module is also provided between the outer casing (1) and the inner casing (2), and the limiting module is at least used to limit the circumferential relative displacement between the outer casing (1) and the inner casing (2).

4. The casing cooling structure according to claim 3, characterized in that, The limiting module includes: The second limiting groove (62) is provided in the inner casing (2); A limiting hole (67) is provided in the outer casing (1); the limiting hole (67) corresponds to the second limiting groove (62), and the inner diameter of the limiting hole (67) is larger than the inner diameter of the second limiting groove (62); Limiting pin (68); the limiting pin (68) is both interference-fitted with the second limiting groove (62) and interference-fitted with the limiting hole (67).

5. The casing cooling structure according to claim 3, characterized in that, The limiting module includes: The second limiting groove (62) is provided in the inner casing (2); A third limiting groove (63) is provided in the outer casing (1); the third limiting groove (63) corresponds to the second limiting groove (62); Limiting post (65); the limiting post (65) is adapted to the second limiting groove (62) and the third limiting groove (63) respectively; the first length is greater than the first depth, the first length is the length of the limiting post (65) along the first direction; the first depth is the depth of the third limiting groove (63) along the first direction; the first direction is parallel to the axial direction of the inner casing (2); The first elastic element (64) is disposed between the second limiting groove (62) and the limiting post (65) to generate a counterforce parallel to the first direction between the limiting post (65) and the third limiting groove (63); and the sum of the first length and the second length is less than or equal to the second depth; the second length is the minimum length formed by the first elastic element (64) after being compressed along the first direction within the elastic deformation range; the second depth is the depth of the second limiting groove (62) along the first direction.

6. The casing cooling structure according to any one of claims 1 to 5, characterized in that, It also includes an adjustment module, which is disposed in the outer casing (1) or the inner casing (2) for adjusting the opening of the cooling channel (4).

7. The casing cooling structure according to claim 6, characterized in that, The adjustment module includes an adjustment ring (71), which is threadedly connected to the outer casing (1) or the inner casing (2) by a plurality of fastening bolts (72).

8. The casing cooling structure according to claim 7, characterized in that, The adjusting ring (71) is elastic; and the adjusting ring (71) includes a curved section (711) and a horizontal section (712) such that the radial width of the adjusting ring (71) is positively correlated with the axial compressive force applied to the adjusting ring (71).

9. The casing cooling structure according to claim 7, characterized in that, The cross-section of the adjusting ring (71) is shaped like the number 7, and the bolt shank of each fastening bolt (72) moves through the adjusting ring (71); the casing cooling structure also includes a second elastic element (73) corresponding to each fastening bolt (72); each second elastic element (73) is located between the adjusting ring (71) and the casing, and each second elastic element (73) is used to apply an elastic force along a second direction to the adjusting ring (71); the second direction is parallel to the axis of the fastening bolt (72) corresponding to the second elastic element (73), and is directed from the bolt shank of the fastening bolt (72) to the bolt head.

10. A gas turbine, characterized in that, Includes the casing cooling structure as described in any one of claims 1 to 9.

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