A CMC turbine outer ring assembly with high thermal match to mid-pod and method of manufacture

Abstract

The present application relates to the technical field of ceramic matrix composite turbine components, and discloses a CMC turbine outer ring assembly with high thermal matching of a middle layer casing and a preparation method, wherein the present application realizes the thermal deformation self-adaptation and stable connection of the whole CMC turbine outer ring assembly by combining the elastic pre-pressing structure with the V-shaped distribution of the inclined plate. The present application realizes the cooling of the CMC turbine outer ring body by designing the cooling channel in the CMC turbine outer ring, and the heat exchange between the cooling channel and the CMC turbine outer ring, and forms the air film cooling layer on the inner concave side outer wall surface of the CMC turbine outer ring, so as to reduce the wall surface temperature of the CMC turbine outer ring by using the air film cooling, realize the high-efficiency cooling, match the high-temperature working environment of the middle layer casing, and improve the structural stability and service life of the whole turbine outer ring.

Description

Technical Field

[0001] This invention relates to the field of ceramic matrix composite turbine components, and discloses a CMC turbine outer ring assembly that is thermally matched with the middle casing and its preparation method. Background Technology

[0002] During the operation of a gas turbine engine, the turbine outer ring, as a core stationary component that isolates the high-temperature combustion gases and ensures efficient work of the turbine system, must withstand the scouring of high-temperature combustion gases exceeding 1200℃, cyclic thermal loads, and vibration loads over long periods. Its structural reliability, thermal deformation compatibility, and cooling effect directly determine the engine's performance ceiling and service life. In existing technologies, the connection between the turbine outer ring and the intermediate casing generally suffers from the following problems:

[0003] (1) Severe thermal deformation mismatch: The thermal expansion coefficients of the CMC turbine outer ring and the high-temperature alloy middle casing differ by 5 to 6 times. The CMC turbine outer ring and the high-temperature alloy middle casing adopt the traditional "rigid planar bonding" connection method. Due to the large difference in deformation between the two at the working temperature, huge thermal stress is easily generated, leading to cracking of the CMC outer ring, deformation of the casing, and even loosening of the connection and gas leakage. (2) Insufficient cooling efficiency: Most existing cooling solutions rely on the gap between the "middle casing and the outer ring of the turbine" to indirectly guide the air. However, the air path is long, the air is unevenly distributed, and the gap is difficult to seal, resulting in the temperature of the local "hot spot" of the outer ring of the turbine exceeding 1000℃, which accelerates the failure of CMC material. (3) Poor connection stability and vibration suppression: Existing pin-spring connections mostly use ordinary metal springs, but the elasticity of the springs decays quickly at high temperatures (the elastic modulus decreases by 30% above 600℃), and it cannot maintain the preload for a long time, resulting in a gap between the turbine outer ring and the middle casing, causing vibration and collision; and lack of targeted damping design, it is difficult to suppress high-frequency vibration during engine operation, further reducing structural reliability. Summary of the Invention

[0004] The purpose of this invention is to provide a CMC turbine outer ring assembly and its preparation method that are highly heat-matched with the middle casing, which can improve the cooling efficiency and connection stability of the CMC turbine outer ring assembly and improve the thermal deformation matching degree between the CMC turbine outer ring and the high-temperature alloy middle casing.

[0005] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows: A CMC turbine outer ring assembly for high-temperature matching with the middle casing includes: The CMC turbine outer ring is a hollow circular ring structure with an outer ring cold air cavity, and the CMC turbine outer ring is provided with a first inclined wall plate and a second inclined wall plate, the first inclined wall plate and the second inclined wall plate are distributed in a V shape that is wider at the top and narrower at the bottom. The CMC turbine outer ring comprises a front middle casing and a rear middle casing, which are respectively disposed on both sides of the CMC turbine outer ring. The front middle casing and the rear middle casing are respectively provided with a front mounting ramp and a rear mounting ramp, which are arranged in a V-shape with a wider top and a narrower bottom. The front mounting ramp is attached to a first inclined wall plate, and the rear mounting ramp is attached to a second inclined wall plate. The front mounting ramp and the rear mounting ramp are used to guide the CMC turbine outer ring to slide radially relative to the front middle casing and the rear middle casing at the operating temperature. The elastic preload structure is respectively installed on the inner walls of the front middle casing and the rear middle casing, and is used to apply a preload force to the outer ring of the CMC turbine, forcing the first inclined wall plate to be tightly attached to the front mounting inclined plate, and at the same time forcing the second inclined wall plate to be tightly attached to the rear mounting inclined plate. The CMC turbine outer ring is provided with an outer ring air inlet, and the front middle layer casing is provided with a first air inlet. The first air inlet is connected to the outer ring air inlet and is used to guide cold air into the outer ring cold air chamber. The CMC turbine outer ring is provided with several rows of cooling channel groups along the circumference of the CMC turbine outer ring. Each row of cooling channel groups includes multiple cooling channels located on the same cross section and arranged along the axial direction of the CMC turbine outer ring. These channels are used to guide the cold air in the outer ring cold air chamber to the concave outer wall surface of the CMC turbine outer ring to cool the CMC turbine outer ring and form an air film cooling layer on the concave outer wall surface of the CMC turbine outer ring.

[0006] Furthermore, the CMC turbine outer ring is composed of several arc-shaped segments spliced ​​together, and sealing plates are provided at both ends of the arc-shaped segments to seal the splice seam between two adjacent arc-shaped segments.

[0007] Furthermore, the arc-shaped segment includes an arc-shaped bottom plate and a cover plate. The arc-shaped bottom plate, the first inclined wall plate, the second inclined wall plate, and the cover plate together form a section of the outer ring cold air cavity, and the cross-sectional shape of the outer ring cold air cavity is trapezoidal.

[0008] Furthermore, the elastic preload structure includes a base, a spring, and a pressure actuating element; the base is fixed to the inner walls of the front middle casing and the rear middle casing; the pressure actuating element is slidably connected to the base, and one end of the pressure actuating element abuts against the cover plate; the spring is sleeved on the pressure actuating element, and both ends of the spring abut against the pressure actuating element and the base respectively, for driving the pressure actuating element to apply a preload force to the cover plate.

[0009] Furthermore, the cover plate is provided with mounting holes; The CMC turbine outer ring assembly also includes an impact cooling plate, which is mounted on the cover plate through mounting holes. The impact cooling plate, the front middle casing, and the rear middle casing together form an impact cooling chamber. The impact cooling plate is provided with impact cooling holes to guide the cooling air in the impact cooling chamber to form an impact jet to impact cool the outer convex side wall of the arc-shaped bottom plate.

[0010] Furthermore, the pressure-acting component applies pressure to the impact cooling plate to apply a preload force to the outer ring of the CMC turbine.

[0011] Furthermore, the equivalent diameter of each of the cooling channels is determined by the following formula: ; ; in: For the first The first in the exhaust cooling channel group The design mass flow rate of each cooling channel; For the first The design number of cooling channels in the cooling channel group. ; For the first The first in the exhaust cooling channel group The interference coefficient of each cooling channel; For the first The first in the exhaust cooling channel group Friction coefficient of each cooling channel; For the first The first in the exhaust cooling channel group The design equivalent length of each cooling channel; For the first The first in the exhaust cooling channel group Equivalent diameter of each cooling channel; For the first The first in the exhaust cooling channel group The number of local resistance characteristic points in each cooling channel; For the first The first in the exhaust cooling channel group On the first cooling channel A given local resistance coefficient for a feature point; For the first The first in the exhaust cooling channel group The interference coefficient of each cooling channel; For the first The first in the exhaust cooling channel group Friction coefficient of each cooling channel; For the first The first in the exhaust cooling channel group The design equivalent length of each cooling channel; For the first The first in the exhaust cooling channel group Equivalent diameter of each cooling channel; For the first The first in the exhaust cooling channel group The number of local resistance characteristic points in each cooling channel; For the first The first in the exhaust cooling channel group On the first cooling channel A given local resistance coefficient for a feature point; The design number of rows for the cooling channel assembly inside the arc-shaped base plate; For the first Inter-row interference and integration effect coefficients of the cooling channel group; For the first Equivalent total flow resistance coefficient of the exhaust cooling channel group; For the first Interference coefficient of the cooling channel group; For the first Equivalent total flow resistance coefficient of the exhaust cooling channel group; This represents the total design mass flow rate of all cooling channel groups within the curved base plate. For the first Friction coefficient of the exhaust cooling channel assembly; For the first The total equivalent length of all cooling channels in the exhaust cooling channel group; For the first The total equivalent diameter of all cooling channels in the exhaust cooling channel group; For the first The number of local resistance characteristic points in the exhaust cooling channel group; For the first The integrated local resistance coefficient of the exhaust cooling channel group.

[0012] A method for fabricating a CMC turbine outer ring assembly with high thermal compatibility with the middle casing, for fabricating the CMC turbine outer ring assembly as described above, includes the following steps: A CMC turbine outer ring preform was prepared and densified to obtain the CMC turbine outer ring; The CMC turbine outer ring is assembled with the front middle casing, the rear middle casing, and the elastic preload structure to obtain the CMC turbine outer ring assembly.

[0013] Furthermore, the steps for preparing the CMC turbine outer ring preform include: Several layers of fiber cloth or fiber strips are laid on the lower mold to form an arc-shaped base plate preform; Several layers of fiber cloth or fiber strips are laid on the upper mold to form an upper preform, which includes an Ω-shaped sub-preform and a U-shaped sub-preform; Install the cooling channel forming embedded part on the lower mold, and make the lower end of the cooling channel forming embedded part penetrate the arc-shaped bottom plate preform; The lower mold is closed with the upper mold, and the upper end of the cooling channel forming embedded part penetrates the upper preform. Then the arc-shaped bottom plate preform is sewn to the upper preform to form a CMC turbine outer ring preform containing the cooling channel forming embedded part.

[0014] Furthermore, after obtaining the CMC turbine outer ring preform, the CMC turbine outer ring preform is densified, and then the cooling channel forming embedded part is removed in a directional manner to obtain the CMC turbine outer ring.

[0015] Compared with the prior art, the beneficial effects of this invention are: This invention, by setting a first and second inclined wall plate in a V-shape on the outer ring of the CMC turbine, and simultaneously setting a front mounting inclined plate and a rear mounting inclined plate in a V-shape on the front and rear middle casings respectively, allows the thermal deformation difference between the middle casing and the outer ring of the CMC turbine to be radially slidably compensated, thus avoiding structural stress concentration damage caused by deformation mismatch between the middle casing and the outer ring of the CMC turbine. At the same time, this invention employs an elastic pre-compression structure to ensure that the inclined wall surfaces between the middle casing and the outer ring of the CMC turbine are always tightly fitted. This invention, through the combination of the elastic pre-compression structure and the V-shaped inclined plates, achieves adaptive thermal deformation and stable connection of the entire CMC turbine outer ring assembly. This invention designs a cooling channel within the outer ring of the CMC turbine, allowing cool air to exchange heat with the outer ring and thus cool the CMC turbine body. Simultaneously, an air film cooling layer is formed on the concave outer wall of the CMC turbine outer ring, reducing the wall temperature and achieving efficient cooling. This is suitable for the high-temperature operating environment of the middle casing and improves the overall structural stability and service life of the turbine outer ring. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the CMC turbine outer ring assembly that is thermally matched with the middle casing in Example 1; Figure 2 This is a cross-sectional view of the CMC turbine outer ring assembly that is thermally matched with the middle casing in Example 1; Figure 3 This is a schematic diagram of the CMC turbine outer ring in Example 1; Figure 4 This is a cross-sectional view of the first configuration of the CMC turbine outer ring in Example 1; Figure 5This is a cross-sectional view of the second configuration of the CMC turbine outer ring in Example 1; Figure 6 This is a schematic diagram of the front middle layer casing in Example 1; Figure 7 This is a cross-sectional view of the front middle casing in Example 1; Figure 8 This is a schematic diagram of the rear middle casing in Example 1; Figure 9 This is a cross-sectional view of the rear middle casing in Example 1; Figure 10 This is a schematic diagram of the perforated pin in Example 1; Figure 11 This is a schematic diagram of the CMC turbine outer ring assembly that is thermally matched with the middle casing in Example 2; Figure 12 This is a cross-sectional view of the CMC turbine outer ring assembly that is thermally matched with the middle casing in Example 2; Figure 13 This is a schematic diagram of the CMC turbine outer ring in Example 2; Figure 14 This is a schematic diagram of the sealing plate and the outer ring of the CMC turbine in Example 2; Figure 15 This is a schematic diagram of the impact cooling plate in Example 2; Figure 16 This is a cross-sectional view of the impact cooling plate in Example 2; Figure 17 This is a schematic diagram of the structure of the CMC turbine outer ring preform; Figure 18 This is a schematic diagram of the upper and lower molds being closed in the embodiment. Figure 19 This is a schematic diagram of the lower mold in the embodiment; Figure 20 This is a schematic diagram of the structure of the pre-embedded part for forming the cooling channel in the embodiment; Figure 21 This is a schematic diagram of the cooling channel positioning plate in the embodiment; Figure 22 This is a cross-sectional view of the cooling channel positioning plate in the embodiment; Figure 23 This is a schematic diagram of the cooling channel positioning plate assembly in the embodiment; Figure 24 This is a cross-sectional view of the cooling channel positioning plate assembly in the embodiment; Figure 25 This is a flowchart illustrating the method for fabricating the CMC turbine outer ring assembly that is thermally matched with the middle casing in this embodiment; Among them, 1-front middle casing, 11-front mounting ramp, 12-base, 13-positioning baffle, 14-first air inlet, 15-second air inlet, 2-CMC turbine outer ring, 21-arc-shaped base plate, 22-first inclined wall plate, 23-second inclined wall plate, 24-cover plate, 25-mounting hole, 213-outer ring air inlet, 31-impact positioning hole, 26-U-shaped sealing plate, 27-I-shaped sealing plate, 28-cooling channel, 29-outer ring cold air chamber, 30-impact cold air chamber, 3-pressure actuating element, 4-spring, 5-rear middle casing, 51-rear mounting ramp, 6-impact cooling plate, 61-cold air slot, 62-positioning boss. 63-Impact cooling hole, 64-Flanged mounting edge, 701-Ω-shaped sub-preform, 702-U-shaped sub-preform, 703-Arc-shaped base plate preform, 801-Upper mold, 8011-Left sub-mold, 8012-Middle sub-mold, 8013-Right sub-mold, 8014-Radial upper stitching hole of preform, 8015-Axial upper stitching hole of preform, 802-Lower mold, 901-Cooling channel forming embedded part, 904-Cooling channel positioning plate, 9041-Positioning block, 9042-Fixing hole, 9043-Fixing groove, 8022-Mold positioning groove, 8021-Radial lower stitching hole of preform, 8023-Lower positioning hole of embedded part. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0018] See Figure 1 and Figure 24 The present invention provides a CMC turbine outer ring assembly that is thermally matched with the middle casing, comprising: CMC turbine outer ring 2, the CMC turbine outer ring 2 is a hollow ring structure with an outer ring cold air cavity 29, and the CMC turbine outer ring 2 is provided with a first inclined wall plate 22 and a second inclined wall plate 23, the first inclined wall plate 22 and the second inclined wall plate 23 are distributed in a V shape that is wider at the top and narrower at the bottom. The front middle casing 1 and the rear middle casing 5 are respectively disposed on both sides of the CMC turbine outer ring 2, and the front middle casing 1 and the rear middle casing 5 are respectively provided with a front mounting ramp 11 and a rear mounting ramp 51. The front mounting ramp 11 and the rear mounting ramp 51 are distributed in a V shape with a wider upper part and a narrower lower part. The front mounting ramp 11 is attached to the first inclined wall plate 22, and the rear mounting ramp 51 is attached to the second inclined wall plate 23. The front mounting ramp 11 and the rear mounting ramp 51 are used to guide the CMC turbine outer ring 2 to slide radially relative to the front middle casing 1 and the rear middle casing 5 at the operating temperature. The elastic preload structure is respectively installed on the inner walls of the front middle casing 1 and the rear middle casing 5, and is used to apply a preload force to the CMC turbine outer ring 2, forcing the first inclined wall plate 22 to be tightly attached to the front mounting inclined plate 11, and at the same time forcing the second inclined wall plate 23 to be tightly attached to the rear mounting inclined plate 51. The CMC turbine outer ring 2 is provided with an outer ring air inlet, and the front middle layer casing 1 is provided with a first air inlet 14. The first air inlet 14 is connected to the outer ring air inlet 213 and is used to guide cold air into the outer ring cold air chamber 29. Several rows of cooling channel groups are provided in the inner circumference of the CMC turbine outer ring 2. Each row of cooling channel groups includes multiple cooling channels 28 located on the same cross section and arranged in the axial direction of the CMC turbine outer ring 2. These channels are used to guide the cold air in the outer ring cold air chamber 29 to the concave outer wall surface of the CMC turbine outer ring 2 to cool the CMC turbine outer ring 2 and form an air film cooling layer on the concave outer wall surface of the CMC turbine outer ring 2.

[0019] Based on the same inventive concept, see [link to inventive concept] Figure 25 The present invention also provides a method for fabricating a CMC turbine outer ring assembly that is thermally matched with the middle casing, for fabricating the aforementioned CMC turbine outer ring assembly, comprising the following steps: A CMC turbine outer ring preform was prepared and densified to obtain CMC turbine outer ring 2; The CMC turbine outer ring 2 is assembled with the front middle casing 1, the rear middle casing 5, and the elastic preload structure to obtain the CMC turbine outer ring assembly.

[0020] This invention provides a first inclined wall plate 22 and a second inclined wall plate 23 arranged in a V-shape on the outer ring 2 of the CMC turbine. Simultaneously, a front mounting inclined plate 11 and a rear mounting inclined plate 51 arranged in a V-shape are provided on the front middle casing 1 and the rear middle casing 5, respectively. This allows the thermal deformation difference between the middle casing and the outer ring of the CMC turbine to be radially compensated by sliding at operating temperatures, thus avoiding structural stress concentration damage caused by deformation mismatch between the middle casing and the outer ring of the CMC turbine. Furthermore, this invention employs an elastic pre-compression structure to ensure that the inclined wall surfaces between the middle casing and the outer ring of the CMC turbine are always tightly fitted. By combining the elastic pre-compression structure with the V-shaped inclined plates, this invention achieves adaptive thermal deformation and stable connection of the entire CMC turbine outer ring assembly. This invention designs a cooling channel 28 inside the CMC turbine outer ring 2, where cool air exchanges heat with the CMC turbine outer ring 2, thereby cooling the CMC turbine outer ring 2 body. At the same time, an air film cooling layer is formed on the outer wall surface of the concave side of the CMC turbine outer ring 2, which reduces the wall temperature of the CMC turbine outer ring 2, achieving efficient cooling. This is suitable for the high-temperature working environment of the middle casing and improves the overall structural stability and service life of the turbine outer ring.

[0021] Example 1 This embodiment further elaborates on the details of the CMC turbine outer ring assembly and its preparation method that are highly thermally matched with the middle casing of the present invention, as follows.

[0022] See Figures 1 to 2 A CMC turbine outer ring assembly that is highly heat-matched with the middle casing, comprising a front middle casing 1, a CMC turbine outer ring 2, an elastic preload structure, and a rear middle casing 5, wherein each component works together to achieve the functions of "thermal deformation self-adaptation + efficient cooling + stable connection", and the whole is arranged in an axisymmetric layout to fit the installation space of the engine turbine section.

[0023] See Figures 3 to 4 The CMC turbine outer ring is a hollow circular structure with an outer ring cooling chamber 29, and is composed of several arc-shaped segments. Specifically, the arc-shaped segments include an arc-shaped base plate 21, a first inclined wall plate 22, a second inclined wall plate 23, and a cover plate 24; all the arc-shaped base plates 21 form a ring to form an engine gas flow channel; the first inclined wall plate 22 and the second inclined wall plate 23 are distributed in a V-shape with a wider top and a narrower bottom, and the arc-shaped base plate 21, the first inclined wall plate 22, the second inclined wall plate 23, and the cover plate 24 together form a closed outer ring cooling chamber 29 with a trapezoidal cross-sectional shape.

[0024] Furthermore, sealing grooves are provided at both ends of the arc segment. The sealing grooves include a U-shaped sealing groove and a straight sealing groove. A U-shaped sealing plate 26 and a straight sealing plate 27 are respectively installed in the U-shaped sealing groove and the straight sealing groove to seal the splice between two adjacent arc segments and reduce the leakage of cold air between two adjacent arc segments.

[0025] See Figure 1 The front middle casing 1 and the rear middle casing 5 are respectively located on both sides of the CMC turbine outer ring 2, and the upper parts of the front middle casing 1 and the rear middle casing 5 are connected by bolts. See also Figures 6 to 9The lower part of the front middle casing 1 is provided with a front mounting ramp 11, and the lower part of the rear middle casing 5 is provided with a rear mounting ramp 51. The front mounting ramp 11 and the rear mounting ramp 51 are distributed in a V-shape with the upper part wider and the lower part narrower. After the front middle casing 1, the CMC turbine outer ring 2 and the rear middle casing 5 are assembled together, the front mounting ramp 11 is attached to the first inclined wall plate 22, and the rear mounting ramp 51 is attached to the second inclined wall plate 23. Both the front middle casing 1 and the rear middle casing 5 are made of high-temperature alloy. At operating temperature, due to the different thermal deformation amounts of the front middle casing 1, the CMC turbine outer ring 2, and the rear middle casing 5, the CMC turbine outer ring 2 relative to the front middle casing 1 and the CMC turbine outer ring 2 relative to the rear middle casing 5 will slide relative to each other. In this embodiment, the front mounting ramp 11 and the rear mounting ramp 51 are used to guide the CMC turbine outer ring 2 to slide freely in the radial direction relative to the middle casing. This allows the difference in thermal deformation between the middle casing and the CMC turbine outer ring 2 under high-temperature conditions to be compensated by radial sliding, thereby adapting to the thermal expansion difference between the CMC turbine outer ring 2 and the high-temperature alloy middle casing and avoiding structural stress concentration damage caused by the deformation mismatch between the middle casing and the CMC turbine outer ring 2.

[0026] It should be noted that the operating temperature in this embodiment refers to a temperature range of ≤1350℃. Furthermore, sealing strips are provided on the front mounting inclined plate 11 and the rear mounting inclined plate 51 to seal the gaps between the front mounting inclined plate 11 and the first inclined wall plate 22, and between the rear mounting inclined plate 51 and the second inclined wall plate 23, preventing leakage. Further, guide grooves can be provided on the walls of the front mounting inclined plate 11 and the rear mounting inclined plate 51 to guide cold air to cool the sealing strips, preventing the sealing strips from failing.

[0027] See Figures 1 to 9 Both the front middle casing 1 and the rear middle casing 5 have the same number of elastic preload structures on their inner walls, arranged symmetrically along the circumference of the middle casing. Each elastic preload structure includes a base 12, a spring 4, and a pressure actuating element 3. Taking the front middle casing 1 as an example, the base 12 is fixed to the inner wall of the front mounting ramp 11. The base 12 has a stepped hole, which includes a large-diameter section and a small-diameter section. The small-diameter section is used to accommodate the pressure actuating element 3, while the large-diameter section provides installation space for the spring 4. The pressure actuating element 3 is a perforated pin made of a high-temperature resistant material, such as... Figure 10As shown, the perforated pin is inserted into the stepped hole of the base 12 from bottom to top, and the perforated pin can slide up and down in the stepped hole. Furthermore, a positioning pin is installed at the upper end of the perforated pin through the pin hole to prevent the perforated pin from disengaging from the stepped hole. The lower end of the perforated pin abuts against the cover plate 24. The spring 4 is a high-temperature damping spring, sleeved on the perforated pin. The upper end of the spring 4 abuts against the step in the stepped hole, and the lower end of the spring 4 abuts against the head of the perforated pin. In the cold state, the spring 4 is in a compressed state. At operating temperature, it drives the perforated pin to apply a preload force to the cover plate 24, forcing the first inclined wall plate 22 to tightly adhere to the front mounting inclined plate 11, and simultaneously forcing the second inclined wall plate 23 to tightly adhere to the rear mounting inclined plate 51, thus achieving a stable connection of the CMC turbine outer ring assembly. It should be noted that, see... Figure 8 and Figure 9 In the elastic preload structure on the rear middle casing 5, the base 12 is fixed to the inner wall of the rear mounting ramp 51, and the elastic preload structure on the rear middle casing 5 is the same as that on the front middle casing 1.

[0028] The high-temperature damping spring is made of Inconel 718 alloy. At the operating temperature, the preload of the high-temperature damping spring keeps the outer ring 2 of the CMC turbine in contact with the middle casing. Even if the spring experiences slight elastic decay due to high temperature, the preload can be maintained by the alloy damping characteristics to prevent loosening.

[0029] In this embodiment, the CMC turbine outer ring 2 is provided with an outer ring air inlet 213, and the front middle casing 1 is provided with a first air inlet 14. The first air inlet 14 communicates with the outer ring air inlet 213 and is used to guide cold air into the outer ring cold air chamber 29. Furthermore, see... Figure 4 Inside the arc-shaped base plate 21, several rows of cooling channel groups are arranged circumferentially along the outer ring 2 of the CMC turbine. Each row of cooling channel groups includes multiple cooling channels 28 arranged on the same cross section along the axial direction of the outer ring 2 of the CMC turbine. In each row of cooling channel groups, the cooling channels 28 are not interconnected and are connected in parallel. The cooling channels 28 are used to guide the cold air flow from the outer ring cold air chamber 29 to the concave side of the arc-shaped base plate 21. During the flow of the cold air along the cooling channels 28, heat exchange is completed through convection, thereby cooling the arc-shaped base plate 21. At the same time, after the cold air flows out of the cooling channels 28, an air film cooling layer is formed on the concave side wall of the arc-shaped base plate 21 to achieve air film cooling, which prevents the high-temperature gas from the engine combustion passage from directly scouring the arc-shaped base plate 21, thereby improving cooling efficiency.

[0030] It should be noted that the cooling channel 28 on the outer ring 2 of the CMC turbine can be a straight-through flow channel, such as... Figure 5 As shown, the cooling channels 28 on the outer ring 2 of the CMC turbine can also employ a combination of straight and curved flow channels, such as... Figure 4 As shown.

[0031] In this embodiment, the cooling channels 28 on the CMC turbine outer ring 2 employ a combination of straight and curved flow channels, and the equivalent diameter of each cooling channel 28 in each row of cooling channels is determined by the following formula: ; ; in: For the first The first in the exhaust cooling channel group The design mass flow rate of each cooling channel is 28. For the first The design number of cooling channels in the cooling channel group. ; The number of rows of cooling channels within the arc-shaped base plate 21 is designed; For the first The first in the exhaust cooling channel group The interference coefficient of each cooling channel 28 characterizes the additional flow resistance amplification effect caused by airflow coupling between adjacent cooling channels in the same row, and its value ranges from 1 to 1. ≤1.8, the specific value is determined and adjusted by those skilled in the art based on experience, especially for the low-temperature region with sparse channels on the turbine outer ring. The value range is 1.0~1.15, targeting the medium-temperature region on the turbine outer ring. The value range is 1.15~1.40, targeting the high-temperature dense flow channel region at the leading edge of the turbine outer ring. The value range is 1.40~1.80; For the first The first in the exhaust cooling channel group The friction coefficient of each cooling channel 28 is a dimensionless constant, with a value range of [value missing]. Those skilled in the art determine and adjust the specific values ​​based on experience; For the first The first in the exhaust cooling channel group The design equivalent length of each cooling channel is 28. For the first The first in the exhaust cooling channel group The equivalent diameter of each cooling channel is 28. For the first The first in the exhaust cooling channel group The number of local resistance characteristic points (such as inlet, elbow, abrupt change in cross section, outlet) of each cooling channel 28; For the first The first in the exhaust cooling channel group The 28th cooling channel Given the local drag coefficient of the nth feature point, for the nth feature point... When modeling the 28 cooling channels in 3D, specific values ​​were manually calibrated. For the first The first in the exhaust cooling channel group The interference coefficient of each cooling channel, its value range is related to... same; For the first The first in the exhaust cooling channel group The friction coefficient of each cooling channel 28 is a dimensionless constant, with a value range of [value missing]. Those skilled in the art determine and adjust the specific values ​​based on experience; For the first The first in the exhaust cooling channel group The design equivalent length of each cooling channel is 28. For the first The first in the exhaust cooling channel group The equivalent diameter of each cooling channel is 28. For the first The first in the exhaust cooling channel group The number of local resistance characteristic points (such as inlet, elbow, abrupt change in cross section, outlet) of each cooling channel 28; For the first The first in the exhaust cooling channel group The 28th cooling channel Given the local drag coefficient of the nth feature point, for the nth feature point... When modeling the 28 cooling channels in 3D, specific values ​​were manually calibrated. For the first Inter-row interference and integration effect coefficients of cooling channel groups ; For the first The equivalent total flow resistance coefficient of the exhaust cooling channel assembly is adopted. Obtained by formula calculation; For the first Interference coefficient of the cooling channel group at each level. Those skilled in the art determine and adjust the specific values ​​based on experience; For the first Equivalent total flow resistance coefficient of the exhaust cooling channel group; The total design mass flow rate of all cooling channel groups within the arc-shaped base plate 21; For the first The friction coefficient of the exhaust cooling channel assembly is a dimensionless constant. For the first The total equivalent length of all cooling channels in the exhaust cooling channel group; For the first The total equivalent diameter of all cooling channels in the exhaust cooling channel group; For the first The number of local resistance characteristic points designed in the cooling channel group, including inlet, elbow, abrupt change in cross section, outlet, etc. For the first The integrated local resistance coefficient of the cooling channel group, summing the local resistances of all cooling channels in the group at the inlet, bends, abrupt changes, etc., reflects the first... The overall complexity of the exhaust cooling channel assembly.

[0032] This embodiment comprehensively considers the total design mass flow rate of all cooling channel groups within the arc-shaped base plate 21. Design mass flow rate of 28 for each cooling channel Interference coefficient of cooling channel group Interference coefficient between channels in each row of cooling channels Friction coefficient of each cooling channel 28, and design equivalent length of each cooling channel 28. Total number of rows in the cooling channel group The design quantity of 28 cooling channels in each row of cooling channel groups Equivalent total flow resistance coefficient of each row of cooling channels The equivalent diameter of each cooling channel 28 is solved iteratively. This design method can accurately match the given total airflow design index while meeting the requirements for airflow distribution. It avoids excessive or insufficient airflow due to deviations in flow channel size design, which could affect the air cooling effect of the turbine outer ring or the overall aerodynamic efficiency of the engine. At the same time, this design method can also ensure that the airflow distribution of each row of cooling channels and each channel in the same row meets the design expectations, maximizing the air cooling efficiency of the CMC turbine outer ring.

[0033] It should be noted that when solving for the equivalent diameter of each cooling channel 28... At the same time, based on the total design mass flow rate, flow resistance constraints, and flow distribution rules of all cooling channel groups within the arc-shaped base plate 21, the present invention can use the Levenberg-Marquardt (LM) iterative algorithm to determine the equivalent diameter of the cooling channel 28. The inverse calculation, specifically the iterative steps, are as follows: 1) Define the physically feasible region for the equivalent diameter of the cooling channels. Considering the CMC molding process and the size limitations of the flow channel structure, assume the initial equivalent diameter of each cooling channel. ; 2) Set the initial equivalent diameter Substituting the values ​​into the flow rate and flow resistance calculation formulas above, the initial mass flow rate of each cooling channel can be obtained. Construct the objective function for flow deviation; 3) Use the LM algorithm to update the iterative step size and correction amount of the equivalent diameter to obtain the new round of equivalent diameter. ; 4) Repeatedly iterate the calculation. When the deviation between the calculated flow rate and the design flow rate of all cooling channels is less than the preset convergence threshold, the iteration is considered to have converged and the final equivalent diameter of the cooling channel is output. If the convergence condition is not met, continue iterative correction until the convergence requirement is met.

[0034] In this embodiment, see Figures 6 to 8 Positioning baffles 13 are provided at the ends of the front middle casing 1 and the rear middle casing 5, specifically on the inner wall surfaces of the front mounting ramp 11 and the rear mounting ramp 51. The positioning baffles 13 align and contact with the end faces of the CMC turbine outer ring 2, ensuring accurate circumferential and radial positioning of the CMC turbine outer ring 2. Furthermore, the thickness and width of the positioning baffles 13 must be designed to ensure that the sealing of the joint between adjacent arc-shaped segments is not affected.

[0035] Based on the same inventive concept, this embodiment also provides a method for preparing a CMC turbine outer ring assembly that is highly heat-matched with the middle casing. When preparing the CMC turbine outer ring 2, a preform forming mold is required. The preform forming mold is divided into an upper mold 801, a lower mold 802, a cooling channel forming embedded part 901, and a cooling channel positioning plate 904.

[0036] See Figures 18 to 19 The lower mold 802 is an arc plate structure with mold positioning grooves 8022 on both sides. Several radially downward stitching holes 8021 of the preform and several lower positioning holes 8023 of the embedded parts are opened through the lower mold 802. The radially downward stitching holes 8021 of the preform and the lower positioning holes 8023 of the embedded parts do not coincide.

[0037] See Figure 18 The upper mold 801 is composed of three parts: a left sub-mold 8011, a middle sub-mold 8012, and a right sub-mold 8013. Each of the left sub-mold 8011, the middle sub-mold 8012, and the right sub-mold 8013 has several radially upward stitching holes 8014 and axially upward stitching holes 8015 for the preform, as well as several positioning holes on the pre-embedded parts for the cooling channels. The radially upward stitching holes 8014 of the preform in the upper mold 801 and the radially downward stitching holes 8021 of the preform in the lower mold 802 correspond one-to-one.

[0038] See Figure 20The cooling channel forming embedded part 901 is used to form a cooling channel 28 during the preparation of the CMC turbine outer ring 2. The cooling channel forming embedded part 901 has the same shape, size, and arrangement as the cooling channel 28. The cooling channel forming embedded part 901 is made of a material capable of directional ablation. In this embodiment, the cooling channel forming embedded part 901 is made of Al2O3, which has a melting point of 2050℃ and will not react during the CVI-PIP densification process.

[0039] See Figures 21 to 24 The cooling channel positioning plate 904 is used to accurately position the cooling channel forming pre-embedded part 901 on the lower mold 802. The cooling channel positioning plate 904 is provided with fixing holes 9042 and fixing grooves 9043 for positioning the cooling channel forming pre-embedded part 901. The cooling channel forming pre-embedded part 901 is inserted into the fixing holes 9042 and fixing grooves 9043 without loosening or falling out, forming the cooling channel positioning plate assembly 909. See [link to documentation]. Figure 23 and Figure 21 Furthermore, the cooling channel positioning plate 904 is equipped with a positioning block 9041, which cooperates with the mold positioning groove 8022 of the lower mold 802 to achieve positioning and ensure that the cooling channel forming embedded part 901 can be accurately inserted into the embedded part lower positioning hole 8023 of the lower mold 802.

[0040] It should be noted that, since the cooling channels 28 on the CMC turbine outer ring 2 in this embodiment employ a mixture of straight and curved flow channels, the cooling channel forming embedded part 901 also includes straight sub-embedded components and curved sub-embedded components. If the cooling channels 28 on the CMC turbine outer ring 2 only employ straight flow channels, then the cooling channel forming embedded part 901 also correspondingly employs straight sub-embedded components, and a cooling channel positioning plate 904 adapted to the straight sub-embedded components can be used.

[0041] In this embodiment, the steps of the CMC turbine outer ring assembly fabrication method include: Step 1: Lay several layers of fiber cloth or fiber strips on the lower mold 802 to form an arc-shaped base plate preform 703.

[0042] Step 2: Assemble the cooling channel forming embedded part 901 and the cooling channel positioning plate 904 into a cooling channel positioning plate assembly 909. Then, assemble the cooling channel positioning plate assembly 909 with the lower mold 802 containing the arc-shaped base plate preform 703. The positioning block 9041 of the cooling channel positioning plate is inserted into the mold positioning groove 8022 of the lower mold 802. After the lower end of the cooling channel forming embedded part 901 pierces through the arc-shaped base plate preform 703, it is inserted into the embedded part lower positioning hole 8023 of the lower mold 802 and fixed on the lower mold 802. During the process of the cooling channel forming embedded part 901 piercing through the arc-shaped base plate preform 703, the fibers at local positions of the arc-shaped base plate preform 703 undergo slight movement, providing space for the cooling channel forming embedded part 901 without disrupting the fiber continuity.

[0043] Step 3: Lay several layers of fiber cloth or fiber strips on the surface of the neutron mold 8012 to form a U-shaped sub-preform 702. Then place the prepared Ω-shaped sub-preform 701 on the neutron mold 8012. Finally, place the left sub-mold 8011 and the right sub-mold 8013 in the preset positions. The U-shaped sub-preform 702 and the Ω-shaped preform 701 together constitute the upper preform.

[0044] Step 4: Remove the cooling channel positioning plate 904, close the upper mold 801 and the lower mold 802, and at the same time, make the upper end of the cooling channel forming embedded part 901 penetrate the upper preform and pass through the positioning hole on the cooling channel forming embedded part of the upper mold 801. When closing the mold, the upper mold 801 and the lower mold 802 are positioned and fixed by matching the positioning pin and the mold positioning groove 8022 of the lower mold 802.

[0045] Step 5: Radially stitch the combination of the arc-shaped base plate preform 703 and the upper preform along the radial stitching hole 8014 of the preform in the upper mold 801 and the radial stitching hole 8021 of the preform in the lower mold 802. Axially stitch the combination along the axial stitching hole 8015 of the preform in the upper mold 801 to finally form the CMC turbine outer ring preform, which contains the cooling channel forming embedded part 901 inside.

[0046] Step Six: The turbine outer ring preform is densified using the CVI-PIP process to obtain the CMC turbine outer ring 2. Then, the CMC turbine outer ring 2 is immersed in a directional removal liquid, causing the pre-embedded cooling channel forming component 901 embedded within the CMC turbine outer ring 2 to react and dissolve with the directional removal liquid. After all the pre-embedded cooling channel forming component 901 is dissolved and removed, the required cooling channel 28 is formed within the CMC turbine outer ring 2. Finally, the CMC turbine outer ring 2 with the internal cooling channel 28 is removed. The directional removal liquid is molten NaOH at a temperature not exceeding 800°C. It should be noted that those skilled in the art can also use other processes to densify the turbine outer ring preform.

[0047] Step 7: Install spring 4 and the perforated pin onto the front middle casing 1 and the rear middle casing 5 to complete the assembly of the elastic preload structure of the front middle casing 1 and the rear middle casing 5. Then assemble the CMC turbine outer ring 2 with the front middle casing 1 and the rear middle casing 5 to obtain the CMC turbine outer ring assembly.

[0048] Example 2 This embodiment provides a CMC turbine outer ring assembly that is heat-matched to the middle casing and can adapt to high-temperature operating conditions of 1400°C or higher. The difference between this embodiment and Embodiment 1 is that the CMC turbine outer ring assembly is provided with an impact cooling plate 6, and the cover plate 24 is provided with mounting holes 25. The front middle casing 1 is also provided with a second air inlet 15. The rest of the structure is the same as that of Embodiment 1.

[0049] Specifically, in this example, the cover plate 24 of the CMC turbine outer ring 2 is provided with mounting holes 25, and the outer ring cooling chamber 29 of the CMC turbine outer ring 2 is an open structure. Furthermore, the cover plate 24 is also provided with impact positioning holes 31 for fitting and installing the impact cooling plate 6.

[0050] The impact cooling plate 6 is made of high-temperature alloy and includes a cooling gas groove 61 and a flanged mounting edge 64. The cooling gas groove 61 is an open groove, and the flanged mounting edge 64 is a flanged structure at the opening of the cooling gas groove 61. Four positioning bosses 62 adapted to the mounting holes 25 are provided on the flanged mounting edge 64. The positioning bosses 62 are adapted to the impact positioning holes 31 to ensure that the cooling gas groove 61 is coaxial with the outer ring cooling gas cavity 29 during assembly. In addition, the impact cooling plate 6 is provided with impact cooling holes 63 to guide the cooling gas in the impact cooling gas cavity 30 to form an impact jet to impact cool the outer convex side wall of the arc-shaped base plate 21.

[0051] During assembly, the impact cooling plate 6 is first installed on the CMC turbine outer ring 2. After assembling the elastic preload structures on the front middle casing 1 and the rear middle casing 5, the CMC turbine outer ring 2 is then assembled with the front middle casing 1 and the rear middle casing 5, so that the perforated pins in the elastic preload structure contact the impact cooling plate 6. The impact cooling plate 6 is pressed and fixed by the preload force provided by the spring 4, while ensuring that the CMC turbine outer ring 2 remains in close contact with the front middle casing 1 and the rear middle casing 5. Moreover, the impact cooling plate 6, the front middle casing 1, and the rear middle casing 5 together form the impact cooling chamber 30. The impact cooling plate 6 and the CMC turbine outer ring 2 together form the outer ring cooling chamber 29, which is located below the impact cooling chamber 30.

[0052] During operation, part of the cold air enters the impact cooling chamber 30 through the second air inlet 15 of the front middle casing 1, and then forms an impact jet through the impact cooling hole 63 at the bottom of the cold air slot 61, which forms impact cooling on the arc-shaped bottom plate 21 of the CMC turbine outer ring 2; another part of the cold air enters the outer ring cooling chamber 29 directly through the first air inlet 14 and the outer ring air inlet 213, and then flows into the cooling channel 28 to cool the arc-shaped bottom plate 21. At the same time, an air film cooling layer is formed on the concave side wall of the arc-shaped bottom plate 21 to perform air film cooling and enhance convective heat transfer. This embodiment forms a composite cooling of "impact + air film" through the above structure, which can further reduce the maximum temperature of the CMC turbine outer ring 2 at the operating temperature.

[0053] It should be noted that, in the CMC turbine outer ring assembly of this embodiment, sealing grooves and sealing plates need to be added to the sides of the front middle casing 1 and the rear middle casing 5 to prevent cold air leakage.

[0054] Based on the same inventive concept, this embodiment also provides a method for manufacturing a CMC turbine outer ring assembly that is thermally matched with the middle casing. The difference from Embodiment 1 is that after obtaining the CMC turbine outer ring 2, mounting holes 25 are made on the cover plate 24 of the CMC turbine outer ring 2 according to the design dimensions. During the assembly stage, the CMC turbine outer ring 2 is assembled with the front middle casing 1, the rear middle casing 5, the elastic preload structure, and the impact cooling plate 6 to obtain the CMC turbine outer ring assembly. The remaining steps are the same as in Embodiment 1.

[0055] Compared with the prior art, the CMC turbine outer ring assembly of the present invention, which is highly heat-matched to the middle casing, has the following advantages: (1) The present invention provides a first inclined wall plate 22 and a second inclined wall plate 23 arranged in a V-shape on the outer ring 2 of the CMC turbine, and provides a front mounting inclined plate 11 and a rear mounting inclined plate 51 arranged in a V-shape on the front middle casing 1 and the rear middle casing 5, respectively, to guide the outer ring of the CMC turbine to slide freely in the radial direction relative to the middle casing, so as to adapt to the thermal expansion difference between CMC and high temperature alloy and improve the thermal deformation compatibility of the CMC turbine outer ring assembly.

[0056] (2) The present invention improves the utilization rate of cold air by using the cooling method of "direct air guiding + air film cooling" to achieve efficient cooling and reduce the radial temperature difference of the outer ring of the CMC turbine. At the same time, the present invention can also use the cooling method of "direct air guiding + air film cooling + impact cooling" to further improve the cooling efficiency. Furthermore, the front middle casing 1 and the rear middle casing 5 are equipped with closed sealing plates to reduce the cooling gas leakage rate and improve the sealing performance.

[0057] (3) Strong connection stability and vibration resistance: The present invention utilizes the spring 4 to maintain the preload force for a long time, and through the symmetrical setting of the elastic preload structure, ensures uniform force and improves the connection stability of the CMC turbine outer ring assembly; at the same time, the damping characteristics of the Inconel 718 alloy spring 4 can suppress high-frequency vibration of 1000~2000Hz, so as to improve the vibration resistance of the CMC turbine outer ring assembly.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A CMC turbine outer ring assembly for high-temperature matching with the middle casing, characterized in that, include: CMC turbine outer ring (2), the CMC turbine outer ring (2) is a hollow ring structure with an outer ring cold air cavity (29), and the CMC turbine outer ring (2) is provided with a first inclined wall plate (22) and a second inclined wall plate (23), the first inclined wall plate (22) and the second inclined wall plate (23) are distributed in a V shape with a wider top and a narrower bottom; The front middle casing (1) and the rear middle casing (5) are respectively disposed on both sides of the CMC turbine outer ring (2), and the front middle casing (1) and the rear middle casing (5) are respectively provided with a front mounting ramp (11) and a rear mounting ramp (51). The front mounting ramp (11) and the rear mounting ramp (51) are V-shaped with a wider top and a narrower bottom. The front mounting ramp (11) is fitted with the first inclined wall plate (22), and the rear mounting ramp (51) is fitted with the second inclined wall plate (23). The front mounting ramp (11) and the rear mounting ramp (51) are used to guide the CMC turbine outer ring (2) to slide radially relative to the front middle casing (1) and the rear middle casing (5) at the operating temperature. The elastic preload structure is respectively installed on the inner walls of the front middle layer casing (1) and the rear middle layer casing (5) to apply preload force to the outer ring (2) of the CMC turbine, forcing the first inclined wall plate (22) to be tightly attached to the front mounting inclined plate (11), and at the same time forcing the second inclined wall plate (23) to be tightly attached to the rear mounting inclined plate (51). The CMC turbine outer ring (2) is provided with an outer ring air inlet, and the front middle layer casing (1) is provided with a first air inlet (14). The first air inlet (14) is connected to the outer ring air inlet (213) and is used to guide cold air into the outer ring cold air chamber (29). The CMC turbine outer ring (2) is provided with several rows of cooling channel groups along the circumference of the CMC turbine outer ring (2). Each row of cooling channel groups includes multiple cooling channels (28) located on the same cross section and arranged along the axial direction of the CMC turbine outer ring (2). These channels are used to guide the cold air in the outer ring cold air chamber (29) to the concave outer wall of the CMC turbine outer ring (2) to cool the CMC turbine outer ring (2) and form an air film cooling layer on the concave outer wall of the CMC turbine outer ring (2).

2. The CMC turbine outer ring assembly according to claim 1, characterized in that, The CMC turbine outer ring (2) is composed of several arc segments spliced ​​together. The two ends of the arc segments are provided with sealing plates to seal the splice seam between two adjacent arc segments.

3. The CMC turbine outer ring assembly according to claim 2, characterized in that, The arc segment includes an arc-shaped bottom plate (21) and a cover plate (24). The arc-shaped bottom plate (21), the first inclined wall plate (22), the second inclined wall plate (23), and the cover plate (24) together form a section of the outer ring cold air cavity (29), and the cross-sectional shape of the outer ring cold air cavity (29) is trapezoidal.

4. The CMC turbine outer ring assembly according to claim 3, characterized in that, The elastic preload structure includes a base (12), a spring (4), and a pressure actuating element (3); the base (12) is fixed to the inner wall of the front middle layer casing (1) and the rear middle layer casing (5); the pressure actuating element (3) is slidably connected to the base (12), and one end of the pressure actuating element (3) abuts against the cover plate (24); the spring (4) is sleeved on the pressure actuating element (3), and both ends of the spring (4) abut against the pressure actuating element (3) and the base (12) respectively, for driving the pressure actuating element (3) to apply a preload force to the cover plate (24).

5. The CMC turbine outer ring assembly according to claim 4, characterized in that, The cover plate (24) is provided with mounting holes (25); The CMC turbine outer ring assembly also includes an impact cooling plate (6), which is mounted on the cover plate (24) through mounting holes (25). The impact cooling plate (6), the front middle casing (1), and the rear middle casing (5) together form an impact cooling chamber (30). The impact cooling plate (6) is provided with impact cooling holes (63) to guide the cold air in the impact cooling chamber (30) to form an impact jet to impact cool the outer convex side wall of the arc-shaped bottom plate (21).

6. The CMC turbine outer ring assembly according to claim 5, characterized in that, The pressure-acting component (3) applies pressure to the impact cooling plate (6) to apply a preload force to the outer ring (2) of the CMC turbine.

7. The CMC turbine outer ring assembly according to claim 6, characterized in that, The equivalent diameter of each of the cooling channels (28) is determined by the following formula: ； ； in: For the first The first in the exhaust cooling channel group The design mass flow rate of each cooling channel (28); For the first The design number of cooling channels (28) in the exhaust cooling channel group. ; For the first The first in the exhaust cooling channel group Interference coefficient of each cooling channel; For the first The first in the exhaust cooling channel group Friction coefficient of each cooling channel (28); For the first The first in the exhaust cooling channel group The design equivalent length of each cooling channel (28); For the first The first in the exhaust cooling channel group The equivalent diameter of each cooling channel (28); For the first The first in the exhaust cooling channel group The number of local resistance characteristic points of each cooling channel (28); For the first The first in the exhaust cooling channel group The first cooling channel (28) A given local resistance coefficient for a feature point; For the first The first in the exhaust cooling channel group Interference coefficient of each cooling channel; For the first The first in the exhaust cooling channel group Friction coefficient of each cooling channel (28); For the first The first in the exhaust cooling channel group The design equivalent length of each cooling channel (28); For the first The first in the exhaust cooling channel group The equivalent diameter of each cooling channel (28); For the first The first in the exhaust cooling channel group The number of local resistance characteristic points of each cooling channel (28); For the first The first in the exhaust cooling channel group The first cooling channel (28) A given local resistance coefficient for a feature point; The number of rows of cooling channels in the arc-shaped base plate (21) is designed; For the first Inter-row interference and integration effect coefficients of the cooling channel group; For the first Equivalent total flow resistance coefficient of the exhaust cooling channel group; For the first Interference coefficient of the cooling channel group; For the first Equivalent total flow resistance coefficient of the exhaust cooling channel group; The total design mass flow rate of all cooling channel groups within the arc-shaped base plate (21); For the first Friction coefficient of the exhaust cooling channel assembly; For the first The total equivalent length of all cooling channels in the exhaust cooling channel group; For the first The total equivalent diameter of all cooling channels in the exhaust cooling channel group; For the first The number of local resistance characteristic points in the exhaust cooling channel group; For the first The integrated local resistance coefficient of the exhaust cooling channel group.

8. A method for fabricating a CMC turbine outer ring assembly with high thermal compatibility with the middle casing, used to fabricate the CMC turbine outer ring assembly as described in any one of claims 1-7, characterized in that, Includes the following steps: A CMC turbine outer ring preform was prepared and densified to obtain a CMC turbine outer ring (2); The CMC turbine outer ring (2) is assembled with the front middle casing (1), the rear middle casing (5), and the elastic preload structure to obtain the CMC turbine outer ring assembly.

9. The method for manufacturing the CMC turbine outer ring assembly according to claim 8, characterized in that, The steps for preparing the CMC turbine outer ring preform include: Several layers of fiber cloth or fiber strips are laid on the lower mold (802) to form an arc-shaped base plate preform (703); Several layers of fiber cloth or fiber strips are laid on the upper mold (801) to form an upper preform, the upper preform including an Ω-shaped sub-preform (701) and a U-shaped sub-preform (702); Install the cooling channel forming embedded part (901) on the lower mold (802) and make the lower end of the cooling channel forming embedded part (901) penetrate the arc-shaped bottom plate preform (703); The lower mold (802) and the upper mold (801) are closed together, and the upper end of the cooling channel forming embedded part (901) penetrates the upper preform. Then the arc-shaped bottom plate preform (703) is sewn to the upper preform to form a CMC turbine outer ring preform containing the cooling channel forming embedded part (901).

10. The method for manufacturing the CMC turbine outer ring assembly according to claim 9, characterized in that, After the CMC turbine outer ring preform is made, the CMC turbine outer ring preform is densified, and then the cooling channel forming embedded part (901) is removed in a directional manner to obtain the CMC turbine outer ring (2).

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