A CMC turbine vane and method of making the same

Abstract

The application provides a CMC turbine guide vane, which comprises a blade body, an upper edge plate and a lower edge plate, the upper edge plate, the blade body and the lower edge plate are stacked in sequence, the blade body has a leading edge, a trailing edge and a pressure surface and a suction surface between the leading edge and the trailing edge; a first cooling cavity is arranged through the upper edge plate close to the leading edge, a second cooling cavity is arranged through the upper edge plate close to the trailing edge, the first cooling cavity and the second cooling cavity are both provided with film holes which are communicated to the outside of the guide vane, and a cooling channel is arranged through the upper edge plate close to the suction surface.

Description

Technical Field

[0001] This invention relates to the field of turbine guide vanes, and more particularly to a CMC turbine guide vane and its manufacturing method. Background Technology

[0002] With the increasing demands on thrust and efficiency of aero engines, the total inlet temperature of engines is also rising, reaching 1978K under high-temperature takeoff conditions. Currently, for turbine stator components, under traditional cooling and thermal barrier coating technologies, the service temperature and performance of traditional high-temperature alloy materials are nearing their limits, making it difficult to meet the design requirements of next-generation advanced aero engines. Compared to traditional high-temperature alloy materials, ceramic matrix composites (CMCs) have the following advantages: (1) high temperature resistance; (2) corrosion resistance; (3) low density: approximately 1 / 4 to 1 / 3 the density of high-temperature alloys. Based on these advantages, applying CMCs to turbine stator components, such as turbine guide vanes, can improve aero engine performance in many ways, such as reducing cooling gas consumption, increasing turbine temperature, and reducing NOx emissions, thereby meeting the needs of next-generation advanced aero engines.

[0003] The cooling methods for turbine guide vanes mainly include internal cooling and external film cooling. CMC turbine guide vanes also require cooling structures to reduce component temperature and thermal gradients. However, regarding the design of internal cooling structures, compared to guide vanes made of high-temperature alloy materials, CMC guide vanes are difficult to manufacture with complex cooling structures such as impact holes and turbulence columns. Furthermore, due to the high hardness of silicon carbide (SiC) fibers, it is difficult to manufacture structures with small radii of curvature, resulting in a large distance between the internal cooling chamber and the guide vane's trailing edge. This makes the trailing edge difficult to cool and prone to overheating. Simultaneously, the extremely high hardness of densified CMC components makes it difficult to machine long cooling channels. Subsequent subtractive processing using methods such as machining and laser processing presents challenges such as high processing difficulty, low processing efficiency, and damage to the processing interface.

[0004] Regarding the installation of external film cooling orifices, the suction surface of the guide vane has high combustion gas velocity and low pressure. Therefore, film cooling orifices are generally not installed or are installed as few as possible to avoid mixing of the outflowing cold air with the main combustion gas, which would reduce engine efficiency. If film cooling orifices are installed on the suction surface, the outlet of the orifice is usually located near the trailing edge of the guide vane to ensure aerodynamic efficiency. However, the path of the film cooling orifice on the suction surface is long, and the CMC guide vane has extremely high hardness, making it difficult to machine long film cooling orifices. Summary of the Invention

[0005] The objective of this invention is at least to provide a CMC turbine guide vane, and to provide a feasible cooling structure for cooling the CMC turbine guide vane.

[0006] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0007] One embodiment of the present invention provides a CMC turbine guide vane, which includes a blade body, an upper edge plate, and a lower edge plate, which are stacked sequentially. The blade body has a leading edge, a trailing edge, and a pressure surface and a suction surface located between the leading edge and the trailing edge. A first cooling chamber is provided through the guide vane near the leading edge, and a second cooling chamber is provided through the guide vane near the trailing edge. Both the first and second cooling chambers are provided with film cooling holes that communicate with the outside of the guide vane. A cooling channel is provided through the guide vane near the suction surface.

[0008] In some embodiments, the outlet of the first cooling chamber connected to the air film hole outside the guide vane is located near the leading edge; the outlet of the second cooling chamber connected to the air film hole outside the guide vane is located near the trailing edge.

[0009] In some embodiments, the first cooling cavity is adapted to the shape of the front portion of the blade, wherein the front portion of the blade is the part of the blade near the leading edge.

[0010] In some embodiments, there are multiple second cooling chambers, at least one of which is located near the pressure surface and at least one of which is located near the suction surface.

[0011] In some embodiments, the blade includes an inner ring layer, an outer ring layer, and a CMC-filled region; the inner ring layer surrounds a first cooling cavity to define the first cooling cavity; the inner ring layer is joined with the outer ring layer, and the outer ring layer forms the outer periphery of the blade alone or together with the inner ring layer to form the outer periphery of the blade; the area surrounded by the outer periphery of the blade, excluding the first cooling cavity surrounded by the inner ring layer, is the CMC-filled region.

[0012] In some embodiments, the second cooling chamber is disposed in the CMC filling area, or the outer ring layer, or the CMC filling area and the outer ring layer.

[0013] In some embodiments, there are multiple cooling channels, at least one of which is disposed in the inner ring layer, and at least one of which is disposed in the CMC filling area.

[0014] This specification provides a method for preparing a CMC turbine guide vane, which is used to prepare the aforementioned CMC turbine guide vane. The preparation method includes: forming an inner ring layer around a mandrel, the shape of which is adapted to the shape of a first cooling cavity; defining a CMC filling region using an internal pressure mold; curing the inner ring layer and the CMC filling region to form a preform; forming an outer ring layer around the preform; machining a second cooling cavity and a cooling channel in one or more of the inner ring layer, the CMC filling region, and the outer ring layer; laying an upper edge plate and a lower edge plate, and opening holes corresponding to the first cooling cavity, the second cooling cavity, and the cooling channel to form a CMC guide vane; curing the CMC guide vane, and machining film perforations on the cured CMC guide vane; and densifying the CMC guide vane.

[0015] In some embodiments, while laying a prepreg tape around the preform to form an outer ring, at least a portion of the second cooling cavity is defined by the prepreg tape.

[0016] In some embodiments, before forming the outer ring layer, cooling channels and a second cooling cavity are machined through the preform.

[0017] The CMC turbine guide vane structure involved in this invention can effectively cool the suction surface and trailing edge of the guide vane, while ensuring the aerodynamic efficiency of the guide vane, thereby improving engine efficiency. Attached Figure Description

[0018] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related properties or features may have the same or similar reference numerals. Wherein:

[0019] Figure 1 This is a schematic diagram of the structure of the CMC turbine guide vane according to some embodiments;

[0020] Figure 2 This is a cross-sectional view of the blade according to some embodiments;

[0021] Figure 3A This is a schematic diagram of the distribution of cooling channels according to some embodiments;

[0022] Figure 3B This is a schematic diagram of the distribution of cooling channels according to some other embodiments;

[0023] Figure 4 This is a cross-sectional view of the blade according to some other embodiments;

[0024] Figure 5 This is a schematic diagram illustrating the formation of the inner ring layer according to some embodiments;

[0025] Figure 6 This is a schematic diagram illustrating the formation of the CMC filling region according to some embodiments;

[0026] Figure 7A This is a schematic diagram of the processing cooling channel and the second cooling chamber according to some embodiments;

[0027] Figure 7B This is a schematic diagram of the processing cooling channel and the second cooling chamber according to some other embodiments;

[0028] Figure 8A This is a schematic diagram illustrating the formation of the outer ring layer according to some embodiments;

[0029] Figure 8B This is a schematic diagram illustrating the formation of the inner ring layer according to some other embodiments;

[0030] Figure 9 This is a schematic diagram illustrating the formation of the inner ring layer according to some other embodiments;

[0031] Figure 10 This is a cross-sectional view of the guide vane mold according to some other embodiments;

[0032] Figure 11 This is a schematic diagram of guide vane mold closing according to some other embodiments. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0034] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other words can achieve the same purpose, they may be replaced by other expressions.

[0035] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0036] It is understood that the technical terms that may be used in the description of this specification, such as “center,” “longitudinal,” “lateral,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” 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 the implementation method 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 limiting the scope of protection of the invention.

[0037] It should be noted that the use of terms such as "first" and "second" to define features in this article is merely for the purpose of distinguishing the corresponding features. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0038] In the description of this specification, it should also be noted that, unless otherwise expressly specified or limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium, or a connection within two components, etc. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0039] Figure 1 This is a schematic diagram of the structure of a CMC turbine guide vane according to some embodiments.

[0040] like Figure 1 As shown, the CMC turbine guide vane includes an upper edge plate 1, a lower edge plate 2, and a blade body 3. The upper edge plate 1, the blade body 3, and the lower edge plate 2 are stacked and connected sequentially. For ease of explanation, the arrangement direction of the upper edge plate 1, the blade body 3, and the lower edge plate 2 is defined as the stacking direction.

[0041] Figure 2 This is a cross-sectional view of the blade according to some embodiments.

[0042] like Figure 2 As shown, the blade 3 has a leading edge 21, a trailing edge 22, and a pressure surface 23 and a suction surface 24 located between the leading edge 21 and the trailing edge 22. The leading edge 21, pressure surface 23, trailing edge 22, and suction surface 24 are connected sequentially to form the entire periphery of the blade 3. The leading edge 21 and trailing edge 22 are distinguished according to the upstream and downstream positions of the blade 3 in the turbine airflow path, with the airflow flowing from the leading edge 21 to the trailing edge 22. The pressure surface 23 and suction surface 24 are distinguished according to the pressure on the surface of the blade 3, with the pressure on the surface of the pressure surface 23 being greater than the pressure on the surface of the suction surface 24.

[0043] A first cooling chamber 34 is provided through the guide vane near its leading edge 21, and a second cooling chamber 35 is provided through the guide vane near its trailing edge 22. Both the first cooling chamber 34 and the second cooling chamber 35 are provided with air film holes 36 that connect to the pressure surface 23. A cooling channel 37 is provided through the guide vane near its suction surface 24. The first cooling chamber 34, the second cooling chamber 35, and the cooling channel 37 penetrate the guide vane in the stacking direction, that is, the first cooling chamber 34, the second cooling chamber 35, and the cooling channel 37 penetrate the upper edge plate 1, the blade body 3, and the lower edge plate 2. Figure 1 As shown, both the upper edge plate 1 and the lower edge plate 2 are provided with a first cooling chamber opening 301, a second cooling chamber opening 302, and a cooling channel opening 303. The air film vents 36 provided on the blade body 3 are... Figure 1 Not shown in the image.

[0044] The CMC turbine guide vane described in this specification's embodiments introduces high-pressure cooling gas into a first cooling chamber 34 and a second cooling chamber 35. The first cooling chamber 34 is located near the leading edge 21 to achieve impact cooling of the leading edge 21, and the second cooling chamber 35 is located near the trailing edge 22 to achieve impact cooling of the trailing edge 22. The first cooling chamber 34 and the second cooling chamber 35 are respectively connected to film cooling holes 36 to the outside of the guide vane. The cooling gas flows out from the film cooling holes 36, covering the surface of the blade body 3 with a film of gas, isolating the combustion gases, and reducing the temperature of the guide vane. This can shorten the length of the film cooling holes 36, avoiding difficulties in machining the CMC guide vane.

[0045] A cooling channel 37 is provided on the blade 3 near the suction surface 24. Medium-pressure cooling gas is introduced into the cooling channel 37 to impact and cool the suction surface 24. By adjusting the pressure of the cooling gas in the cooling channel 37, the pressure difference between the inside and outside of the suction surface 24 is reduced, thereby reducing the load on the guide vane. Furthermore, it is not necessary to provide film cooling holes on the suction surface 24, which can prevent the cooling gas flowing out of the film cooling holes from mixing with the main combustion gas and reducing engine efficiency.

[0046] See also Figure 2 The first cooling chamber 34 is adapted to the shape of the front part of the blade 3, wherein the front part of the blade 3 is the portion of the blade 3 near the leading edge 21, so that the first cooling chamber 34 is as large as possible to allow more cooling gas to pass through and increase the cooling effect on the guide vane. It can be understood that the first cooling chamber 34 can be one or divided into multiple parts.

[0047] The second cooling chamber 35 is disposed near the trailing edge 22. In some embodiments, the second cooling chamber 35 is adapted to the shape of the rear portion of the blade 3, wherein the rear portion of the blade 3 is the part of the blade 3 near the trailing edge 22, so that the second cooling chamber 35 is as large as possible to allow more cooling gas to pass through and increase the cooling effect on the guide vane. In some embodiments, to ensure the structural strength of the guide vane, a smaller second cooling chamber 35 is disposed near the trailing edge 22, such as... Figure 4 As shown, Figure 4 An embodiment of the second cooling chamber 35 is shown. In some embodiments, to achieve cooling of both sides of the trailing edge 22 (i.e., the portions near the pressure surface 23 and suction surface 24 of the trailing edge 22), see [reference needed]. Figure 4 The second cooling chamber 35 is located on or near the extended centerline of the trailing edge 22. In some embodiments, to further ensure the structural strength of the guide vane, such as... Figure 2 As shown, a smaller second cooling chamber 35 is provided near the trailing edge 22. Figure 2 One embodiment of the second cooling chamber 35 is shown. See also Figure 2 The number of second cooling chambers 35 is at least two, at least one of the at least two second cooling chambers 35 is disposed near the pressure surface 23, and at least one of the at least two second cooling chambers 35 is disposed near the suction surface 24, in order to achieve cooling of both sides of the tail edge 22.

[0048] like Figure 2 and Figure 4 As shown, the outlet of the first cooling chamber 34, which connects to the outside of the guide vane, is located near the leading edge 21. In some embodiments, the outlet of the first cooling chamber 34, which connects to the outside of the guide vane, is located in at least one of the pressure surface 23 region, the leading edge 21 region, and the suction surface throat region near the leading edge 21, for example, as... Figure 2 and Figure 4 As shown, the outlets of the plurality of film cooling holes 36 connected to the outside of the guide vane in the first cooling chamber 34 are located in the pressure surface 23 region, the leading edge 21 region, and the suction surface throat region near the leading edge 21. The outlets of the film cooling holes 36 connected to the outside of the guide vane in the second cooling chamber 35 are located near the trailing edge 22. In some embodiments, the outlets of the film cooling holes 36 connected to the outside of the guide vane in the second cooling chamber 35 are located in at least one region of the pressure surface 23 and the suction surface 24 region near the trailing edge 22, for example, as shown in... Figure 2 and Figure 4 As shown, the outlets of multiple film cooling holes 36 connected to the outside of the guide vane in the second cooling chamber 35 are located in the pressure surface 23 region and the suction surface 24 region near the trailing edge 22. The outlets of the film cooling holes 36 are located at both ends of the pressure surface 23 near the leading edge 21 and the trailing edge 22. The cooling airflow ejected from the film cooling holes 36 forms a film of air, which can cover the pressure surface 23 as much as possible, ensuring the cooling of the pressure surface 23. The outlet of the film cooling hole 36 is located at one end of the suction surface 24 near the trailing edge 22. Specifically, the film cooling hole 36 connecting the second cooling chamber 35 to the suction surface 24 is positioned towards and close to the trailing edge 22. The cooling airflow ejected from this film cooling hole 36 forms a film of air, which assists the cooling channel 37 in insulating and cooling the suction surface 24. In some embodiments, such as... Figure 2As shown, when there are at least two second cooling chambers 35, the air film holes 36 connected to the pressure surface 23 are led out from the second cooling chamber 35 located near the pressure surface 23, and the air film holes 36 connected to the suction surface 24 are led out from the second cooling chamber 35 located near the suction surface 24, thereby reducing the length of the air film holes 36 and avoiding difficulties in processing on the CMC guide vane.

[0049] It should be noted that, Figure 2 and Figure 4 Only a portion of the film cooling hole 36 is shown in the diagram. Film cooling holes 36 can also be arranged at other locations on the pressure surface 23 and suction surface 24. The air supply chamber of the film cooling hole 36 is either the first cooling chamber 34 or the second cooling chamber 35.

[0050] like Figure 2 and Figure 4 As shown, to achieve cooling of the suction surface 24, several cooling channels 37 are provided near the suction surface. Each cooling channel 37 is connected to the upper and lower edge plates. Cooling air flows into each cooling channel 37 from one side edge plate and out from the other side edge plate. The cooling channels 37 are distributed along the suction surface 24. The cooling channels 37 penetrate the guide vanes in the stacking direction, but the distribution of the cooling channels 37 themselves can be varied. Figure 3A and Figure 3B As shown in the example. In some embodiments, such as Figure 3A As shown, the cooling channel 37 generally extends through the upper and lower edge plates along the stacking direction. In some embodiments, such as Figure 3B As shown, the cooling channels 37 are distributed in a winding manner and extend through the upper and lower edge plates in the stacking direction, achieving cooling of a wider range of guide vanes. In some embodiments, such as Figure 3B As shown, the cooling channel 37 extends a certain distance from the middle section of the blade 3 along the stacking direction to the front edge 21 or the trailing edge 22, thereby enhancing the cooling of the middle part of the guide vane.

[0051] In some embodiments, the cross-sectional dimensions of the cooling channel 37 are between 0.6 mm and 4 mm. Through internal heat exchange within the cooling channel 37, the temperature of the suction surface 24 can be reduced. Cooling gas with lower temperature and pressure can be introduced into the cooling channel 37 from a lower-stage compressor, improving the cooling effect on the suction surface 24. Simultaneously, the large pressure difference between the inner and outer surfaces of the suction surface 24, combined with the introduction of medium-pressure cooling gas within the wall thickness, effectively bridges the gap between the wall thickness and the pressure difference, which is beneficial to the strength of the suction surface 24.

[0052] See also Figure 2As shown in Figure 3, according to the CMC guide vane manufacturing process, the blade body 3 includes an inner ring layer 31, a CMC filling region 32, and an outer ring layer 33. The inner ring layer 31 surrounds the first cooling cavity 34 to define the first cooling cavity 34. The outer ring layer 33 forms the periphery of the blade body 3, and the inner ring layer 31 is joined to the outer ring layer 33. In some embodiments, the inner ring layer 31 and the outer ring layer 33 are joined internally and externally, and the outer ring layer 33 surrounds the inner ring layer 31. In some embodiments, the inner ring layer 31 and the outer ring layer 33 are joined in the extending direction of the periphery of the blade body 3, and together they are spliced ​​to form the periphery of the blade body 3, see [reference]. Figure 9 The area surrounding the blade 3, excluding the first cooling cavity 34 enclosed by the inner ring 31, is the CMC filling area 32.

[0053] The second cooling cavity 35 can be disposed in the CMC filling region 32, or in the outer ring layer 33, or partially disposed on the outer ring layer 33 and partially disposed in the CMC filling region 32, combined to form the second cooling cavity 35. In some embodiments, the second cooling cavity 35 can be inside the CMC filling region 32 or on the surface of the CMC filling region 32.

[0054] At least one of the plurality of cooling channels 37 is provided in the inner ring layer 31, and at least one of the plurality of cooling channels 37 is provided in the CMC filling area 32.

[0055] The following will combine Figures 5 to 11 The above embodiments illustrate the preparation method of the CMC turbine guide vane.

[0056] The method for manufacturing CMC turbine guide vanes includes the following steps.

[0057] S1, an inner ring layer 31 is formed around the core mold 41, and the shape of the core mold 41 is adapted to the shape of the first cooling cavity 34.

[0058] Specifically, such as Figure 5 As shown, multiple layers of continuous prepreg tape are laid around the core mold 41 to form an inner ring layer 31. Depending on the structure and number of the first cooling chambers 34, the core mold 41 can be one or more.

[0059] S2, the CMC filling area 32 is defined by the inner pressure mold 42 and the CMC filling area 32 is formed.

[0060] In some embodiments, such as Figure 6 As shown, the prepreg tape is laid and stacked according to the original shape of the filling area 32, combined with the inner ring layer 31, and compacted using the inner pressure mold 42.

[0061] S3, solidify the inner ring layer 31 and the CMC filling area 32 to form a preform.

[0062] In some embodiments, the inner pressure mold 42, along with the inner ring layer 31, CMC filling area 32, and core mold 41 laid inside, are placed together in a high-temperature furnace or autoclave for the first curing. The curing temperature is 85℃-200℃, and the curing time is 2h-24h. After curing, a preform is formed.

[0063] In some embodiments, after curing, the inner mold 42 is disassembled, and subtractive processing methods are used to process the inner ring layer 31 and the CMC filling area 32 to achieve structures such as grooves, holes, and smooth walls. Processing methods include milling, grinding, boring, waterjet machining, laser machining, and electrical discharge machining. In some embodiments, a cooling channel 37 and a second cooling cavity 35 penetrating the preform are machined on the preform. Figure 7A As shown, the second cooling cavity 35 can be machined inside the CMC filling area 32, such as... Figure 7B As shown, it can also be processed on the surface of the CMC-filled area 32. In some embodiments, such as Figure 7A and 7B As shown, some cooling channels 37 are machined on the surface of the CMC filling region 32, and some cooling channels 37 are machined on the surface of the inner ring layer 31. In some embodiments, subtractive processing is performed to eliminate dimensional deviations in the preform, providing an accurate base model for the subsequent layup of the outer ring layer and the edge plate portion.

[0064] S4, forming an outer ring 33 around the precast body.

[0065] Specifically, such as Figures 8A-8B As shown, prepreg tape is laid on the processed preform to form an outer ring layer 33, and an outer pressure mold 44 is installed to compact the blade body 3. Figure 8A The outer ring layer 33 is formed on the basis of the preform processed inside the CMC filling area 32 in the second cooling cavity 35. Figure 8B The diagram shows an outer ring layer 33 formed on the basis of a preform processed on the surface of the CMC filling area 32 in the second cooling chamber 35. Figure 8A The outer ring layer 33 is formed on the basis of the preform processed inside the CMC filling area 32 in the second cooling cavity 35.

[0066] S5, a second cooling cavity 35 and a cooling channel 37 are machined in one or more of the inner ring layer 31, the CMC filling area 32 and the outer ring layer 33.

[0067] The machining of the second cooling cavity 35 and the cooling channel 37 has been described in S3. It is understood that the second cooling cavity 35 and the cooling channel 37 can also be machined after S4. In some embodiments, the second cooling cavity 35 is disposed within the outer ring layer 33, and the outer ring layer 33 is subjected to subtractive machining to obtain the second cooling cavity 35. In some embodiments, the second cooling cavity 35 is disposed on the surface of the outer ring layer 33, such as... Figure 9 As shown, while laying prepreg tape around the preform to form an outer ring layer 33, at least a portion of the second cooling cavity 35 is defined by laying the prepreg tape, and an outer pressure mold 44 is installed and compacted to obtain the second cooling cavity 35 disposed on the surface of the outer ring layer 33. Figure 9 Cooling channel 37 is not shown in the diagram.

[0068] S6, lay the upper edge plate 1 and the lower edge plate 2, and make openings corresponding to the first cooling cavity 34, the second cooling cavity 35 and the cooling channel 37 to form CMC guide vanes.

[0069] like Figure 10 and Figure 11 As shown, upper and lower molds 45 are added to carry out the edge plate layup and guide vane mold closing, and the guide vane is compacted. During the edge plate layup process, openings of the first cooling cavity 34, the second cooling cavity 35 and the cooling channel 37 are formed by pre-reserving holes on the prepreg tape corresponding to the first cooling cavity 34, the second cooling cavity 35 and the cooling channel 37.

[0070] like Figure 11 As shown, the upper and lower molds 45 have through holes 46, 47, and 48 corresponding to the first cooling chamber opening 301, the second cooling chamber opening 302, and the cooling channel opening 303, and are connected to the openings 301, 302, and 303.

[0071] S7, Cure CMC guide vanes, and machine air film holes on the cured CMC guide vanes.

[0072] Specifically, the CMC guide vanes, after being laid up, are placed together with the mold in an autoclave for a second curing process. The curing temperature is 85-200℃, the curing time is 2-24 hours, and the internal pressure is 0.2-5MPa, completing the curing of the CMC guide vanes. In the autoclave, high-pressure gas can enter the open ports 302 and 303 through the through holes 47 and 48, pressurizing the second cooling chamber 35 and the cooling channel 37, thus compacting these two cooling structures and avoiding the need to fill the cooling structures with filler.

[0073] After curing, the mold is removed. The cured CMC guide vane is then machined using subtractive processing to create film cooling holes 36 that connect the internal cooling cavity and the flow channel surface. Machining methods include milling, drilling, laser, EDM, and water jetting.

[0074] S8, dense CMC guide vane.

[0075] Subsequent pyrolysis and melt infiltration processes are performed on the CMC guide vanes to obtain dense CMC guide vanes. The dense CMC guide vanes are then precision-machined to obtain the final CMC guide vane product.

[0076] The method for fabricating CMC turbine guide vanes described in this specification involves a first curing process after the inner ring layer 31 and CMC filling area 32 are laid up, followed by subtractive processing to create the second cooling cavity 35 and cooling channel 37. On this basis, the outer ring layer 33 and upper and lower edge plates are laid up. Holes are made on the upper and lower edge plates corresponding to the positions of the second cooling cavity 35 and cooling channel 37, allowing them to communicate with the outside. A second curing process is performed on the guide vane using an autoclave. In conjunction with the mold design, the pressure of the autoclave is used to pressurize the internal second cooling cavity 35 and cooling channel 37, maintaining and curing them. This avoids the need to fill the second cooling cavity 35 and cooling channel 37 with filler to maintain their shape, and also avoids the need to remove the filler, greatly simplifying the fabrication process.

[0077] The basic concepts have been described above. It is clear that the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification, especially for those skilled in the art. Furthermore, unless expressly stated in the claims, the order of elements and sequences, the use of numbers and letters, or other names in this specification are not intended to limit the order of the processes and methods described herein. Although various examples of currently considered useful embodiments of the invention have been discussed in the foregoing disclosure, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. Rather, the claims are intended to cover all modifications and equivalent combinations that conform to the substance and scope of the embodiments described herein.

Claims

1. A CMC turbine guide vane, characterized in that, The CMC turbine guide vane includes a blade body, an upper edge plate, and a lower edge plate, wherein the upper edge plate, the blade body, and the lower edge plate are stacked sequentially, and the blade body has a leading edge, a trailing edge, and a pressure surface and a suction surface located between the leading edge and the trailing edge; A first cooling chamber is provided through the guide vane near the leading edge, and a second cooling chamber is provided through the guide vane near the trailing edge. Both the first and second cooling chambers are provided with air film holes that communicate with the outside of the guide vane. A cooling channel is provided through the guide vane near the suction surface.

2. The CMC turbine guide vane according to claim 1, characterized in that, The first cooling chamber is connected to the outlet of the film cooling hole outside the guide vane, which is located near the leading edge; The second cooling chamber is connected to the outlet of the film cooling hole outside the guide vane and is located near the trailing edge.

3. The CMC turbine guide vane according to claim 1 or 2, characterized in that, The first cooling cavity is adapted to the shape of the front part of the blade, wherein the front part of the blade is the portion of the blade near the leading edge.

4. The CMC turbine guide vane according to claim 1 or 2, characterized in that, The number of the second cooling chambers is multiple, at least one of the multiple second cooling chambers is disposed near the pressure surface, and at least one of the multiple second cooling chambers is disposed near the suction surface.

5. The CMC turbine guide vane according to any one of claims 1 or 2, characterized in that, The blade includes an inner ring, an outer ring, and a CMC filling area; The inner ring surrounds the first cooling cavity to define the first cooling cavity; The inner ring layer is joined to the outer ring layer, and the outer ring layer alone forms the outer periphery of the leaf blade, or together with the inner ring layer forms the outer periphery of the leaf blade; The area surrounding the blade, excluding the first cooling cavity enclosed by the inner ring layer, is a CMC-filled area.

6. The CMC turbine guide vane according to claim 5, characterized in that, The second cooling chamber is disposed in the CMC filling area, or the outer ring layer, or the CMC filling area and the outer ring layer.

7. The CMC turbine guide vane according to claim 5, characterized in that, The number of cooling channels is multiple, at least one of the multiple cooling channels is disposed in the inner ring layer, and at least one of the multiple cooling channels is disposed in the CMC filling area.

8. A method for manufacturing a CMC turbine guide vane, characterized in that, For manufacturing the CMC turbine guide vane of claim 1, the blade body includes an inner ring layer, an outer ring layer, and a CMC filling region. The inner ring layer surrounds the first cooling cavity to define the first cooling cavity. The inner ring layer is joined to the outer ring layer. The outer ring layer forms the outer periphery of the blade body independently, or forms the outer periphery of the blade body together with the inner ring layer. The area surrounded by the outer periphery of the blade body, excluding the first cooling cavity surrounded by the inner ring layer, is the CMC filling region. The preparation method includes: The inner ring layer is formed around the core mold, and the shape of the core mold is adapted to the shape of the first cooling cavity; The CMC filling area is defined and formed using an internal pressure mold; The inner ring layer and CMC filling area are solidified to form a preform; The outer ring layer is formed around the preform; The second cooling cavity and the cooling channel are machined into one or more of the inner ring layer, the CMC filling area, and the outer ring layer; The upper edge plate and the lower edge plate are laid out, and openings are made corresponding to the first cooling cavity, the second cooling cavity and the cooling channel to form CMC guide vanes; The CMC guide vane is cured, and the air film pores are machined on the cured CMC guide vane; The CMC guide vane is densified.

9. The preparation method according to claim 8, characterized in that, While laying prepreg tape around the preform to form the outer ring layer, at least a portion of the second cooling cavity is defined by the laying of the prepreg tape.

10. The preparation method according to claim 8, characterized in that, Before forming the outer ring layer, the cooling channel and the second cooling cavity that penetrate the preform are machined on the preform.

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