Ceramic-metal combined turbine guide blade and gas turbine thereof

Abstract

A ceramic-metal turbine guide vane comprises a metal rear half, located at the trailing edge; and a front half, located at the leading edge. The front half is designed separately from the metal rear half, forming a complete blade profile. The ceramic front half reduces cooling requirements. The present invention employs a split design, with the ceramic front half forming a solid blade base, while the metal rear half and inner and outer edge plates are constructed from conventional metal and employ a conventional air-cooling structure. Due to the high-temperature resistance of ceramic, cooling of the front half is unnecessary, significantly reducing the cooling requirements for the turbine blades and significantly improving overall gas turbine performance.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine blades, and in particular to a ceramic-metal combined turbine guide blade and a gas turbine thereof. Background Art

[0002] In the future, the turbine inlet temperature of gas turbines will reach over 1500℃, while the safe operating temperature of the most advanced high-temperature alloy blades is about 900℃. The comprehensive cooling efficiency required for the first-stage turbine guide vanes is about 0.65-0.7. According to the existing air cooling technology level, the cooling air demand of turbine components will reach more than 20%. The increase in cooling air consumption will reduce the performance of the gas turbine, which is contrary to the design requirements of high-efficiency gas turbines. Therefore, the development of ceramic blade structure is of great significance to the improvement of my country's gas turbine technology.

[0003] Compared to metal blades, ceramic blades boast mechanical properties such as high-temperature resistance, wear resistance, high hardness, and corrosion resistance, enabling them to operate directly in high-temperature gas environments. However, for many years, ceramic blades have not been widely used in engineering projects, primarily due to their poor toughness, elasticity, and installability. Summary of the Invention

[0004] In view of this, the main object of the present invention is to provide a ceramic-metal combined turbine guide blade and a gas turbine thereof, in order to at least partially solve at least one of the above-mentioned technical problems.

[0005] To achieve the above object, as one aspect of the present invention, a ceramic-metal combined turbine guide vane is provided, comprising:

[0006] The rear half blade body is arranged on one side of the trailing edge, and the material of the rear half blade body is metal;

[0007] The front half blade body is arranged on one side of the leading edge and is designed separately from the rear half blade body, and the front half blade body and the rear half blade body form a complete blade-shaped structure;

[0008] The front half of the blade is made of ceramic, which is used to reduce the demand for cold air for cooling.

[0009] As another aspect of the present invention, a gas turbine is provided, comprising the ceramic-metal combined turbine guide blades as described above.

[0010] Based on the above technical solution, the present invention has at least one or part of the following beneficial effects:

[0011] (1) The blade adopts a split structure, with the front half of the blade body made of ceramic material. Since the ceramic part of the blade body does not need to be cooled, the cooling demand will be greatly reduced under the same gas flow conditions. In addition, considering that the trailing edge of the turbine guide vane is too thin, usually about 1mm, a design is adopted in which the front half of the blade body is provided with a ceramic material on the leading edge side and the rear half of the blade body is provided with a metal material on the trailing edge side, thereby avoiding a vulnerable area of ​​the pure ceramic blade;

[0012] (2) Because the inner and outer edge plates are still made of metal and are connected to the rear half of the blade body, the present invention retains the installation performance of pure metal blades;

[0013] (3) The present invention proposes to use elastic gaskets to encapsulate the front half of the blade to solve the problem that the ceramic part of the blade cannot meet the matching requirements in the hot state because the linear expansion coefficient is smaller than that of the metal part of the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the assembly of a ceramic-metal combined turbine guide blade according to the present invention;

[0015] Figure 2 This is a schematic diagram of the assembly of the ceramic-metal combined turbine guide vane inner edge plate of the present invention;

[0016] Figure 3 Schematic diagram of the middle cooling structure of the ceramic-metal combined turbine guide blade of the present invention;

[0017] Figure 4 A schematic transverse half-section diagram of a ceramic-metal combined turbine guide vane according to an embodiment of the present invention;

[0018] Figure 5 for Figure 4 AA cross-sectional view of the .

[0019] In the above drawings, the meanings of the reference numerals are as follows:

[0020] 1. Front half of the blade body; 2. Rear half of the blade body; 3. Elastic gasket; 4. Cover plate; 5. Air film hole; 6. Groove; 7. Mounting edge; 8. Inner edge plate; 801, Positioning groove; 9. Outer edge plate. DETAILED DESCRIPTION

[0021] The ceramic-metal blade structure proposed in this invention leverages the characteristics of gas turbine blades, which are thickest at the leading edge and thinnest at the trailing edge. This split-body design makes it a feasible engineering solution. Its unique feature is that the leading half of the blade is made of ceramic, with the ceramic portion embedded within the remaining metal portion. When used in the design of gas turbine guide vanes, it can significantly reduce the amount of cooling required for gas turbine blades.

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0023] In an embodiment of the present invention, a ceramic-metal combined turbine guide vane is provided, comprising:

[0024] The rear half of the blade body is arranged on the side of the trailing edge and is made of metal;

[0025] The front half blade body is arranged on the side of the leading edge and is designed separately from the rear half blade body, and the front half blade body and the rear half blade body form a complete blade structure;

[0026] Among them, the material of the front half of the blade is ceramic, which is used to reduce the demand for cold air for cooling.

[0027] In an embodiment of the present invention, the interface between the front half of the blade and the rear half of the blade is located at a position of 0.3 to 0.6 of the relative axial chord length of the complete blade profile.

[0028] In an embodiment of the present invention, the two ends of the rear half of the blade body are fixedly connected to the inner edge plate and the outer edge plate respectively; the inner edge plate and the outer edge plate are made of the same material as the rear half of the blade body; and a mounting edge is provided on the side of the inner edge plate opposite to the rear half of the blade body.

[0029] In an embodiment of the present invention, the rear half of the blade body, the outer edge plate, the inner edge plate and the mounting edge are all made of high-temperature alloy material and are cast in one piece.

[0030] In an embodiment of the present invention, the ceramic-metal combined turbine guide vane further includes an elastic gasket and a cover plate; a positioning groove for encapsulating the front half of the blade body is provided on the side where the inner edge plate is connected to the rear half of the blade body; and mounting holes are provided at corresponding positions on the outer edge plate;

[0031] One end of the front half of the blade extends through the mounting hole and is embedded in the positioning groove. The other end of the front half of the blade is encapsulated at the mounting hole by an elastic gasket and a cover plate. More specifically, the elastic gasket is sandwiched between the front half of the blade and the cover plate, and the cover plate is welded to the outer end surface of the outer edge plate.

[0032] In an embodiment of the present invention, the positioning groove includes a groove bottom and a groove sidewall; the groove bottom is a plane, and the groove sidewall is a conical surface.

[0033] In an embodiment of the present invention, a groove is provided at the blade basin of the front mating surface where the rear half of the blade body contacts the front half of the blade body, or grooves are provided at the blade basin and the blade back respectively; one groove is provided radially or multiple grooves are provided radially at intervals; the cross-sectional shape of the groove is rectangular.

[0034] In an embodiment of the present invention, a plurality of air film holes are provided on the groove for connecting the outside with the cooling cavity of the rear half of the blade body.

[0035] In an embodiment of the present invention, the air film holes are made by electrical machining or laser drilling.

[0036] As another aspect of the present invention, a gas turbine is provided, comprising the ceramic-metal combined turbine guide blades as described above.

[0037] The structure of a ceramic-metal combined turbine guide vane provided by the present invention will be further described below with reference to specific embodiments.

[0038] Example 1

[0039] like Figure 1 and Figure 4 As shown in FIG. 1 , the ceramic-metal combined turbine guide blade structure of the present invention has a front half blade body 1 made of ceramic material, and a metal blade portion including a rear half blade body 2, an inner edge plate 8, an outer edge plate 9 and a mounting edge 7, which are integrally cast from a high-temperature alloy material. Figure 2 As shown, one end of the front half blade body 1 is embedded in the positioning groove 801 of the blade inner edge plate 8, and the positioning groove 801 is chamfered around the angle; Figure 1 and Figure 5 As shown, the other end of the front half blade body 1 is encapsulated by an elastic gasket 3 and a sealing metal cover plate 4. Figure 3 The figure shows a cooling method for the front portion of a metal blade. Grooves 5 and film holes 6 are respectively provided on the blade base and blade back of the front mating surface of the rear half of the blade 2. The grooves 5 can be continuous or discontinuous, and the film holes 6 can be of any shape. The grooves 5 are directly cast, while the film holes 6 are made by electromachining or laser drilling.

[0040] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A ceramic-metal combined turbine guide vane, characterized in that: include: The rear half blade body is arranged on one side of the trailing edge. The rear half blade body is made of metal. The two ends of the rear half blade body are respectively fixedly connected to the inner edge plate and the outer edge plate. The inner edge plate and the outer edge plate are made of the same material as the rear half blade body. The front half blade body is arranged on one side of the leading edge and is designed separately from the rear half blade body, and the front half blade body and the rear half blade body form a complete blade-shaped structure; Elastic gasket and cover plate, the inner edge plate is connected to the rear half of the blade body and is provided with a positioning groove for encapsulating the front half of the blade body; a mounting hole is provided at a corresponding position on the outer edge plate; One end of the front half blade body passes through the mounting hole and is embedded in the positioning groove, and the other end of the front half blade body is encapsulated at the mounting hole in sequence through an elastic gasket and a cover plate; the positioning groove includes a groove bottom and a groove sidewall; the groove bottom is a plane, and the groove sidewall is a conical surface; The front half of the blade is made of ceramic to reduce the demand for cooling air. The interface between the front half of the blade and the rear half of the blade is at a position 0.3 to 0.6 of the relative axial chord length of the complete blade profile; the blade of the turbine guide vane is thickest at the leading edge and thinnest at the trailing edge; A groove is provided at the blade basin of the front mating surface where the rear half blade body contacts the front half blade body; a plurality of air film holes are provided on the groove for connecting the outside with the cooling cavity of the rear half blade body.

2. The ceramic-metal combined turbine guide vane according to claim 1, characterized in that: A mounting edge is provided on a side of the inner edge plate opposite to the rear half blade body.

3. The ceramic-metal combined turbine guide vane according to claim 2, characterized in that: The rear half blade body, outer edge plate, inner edge plate and mounting edge are all made of high temperature alloy material and are cast in one piece.

4. The ceramic-metal combined turbine guide vane according to claim 1, characterized in that: The groove is arranged one at a time along the radial direction or a plurality of grooves are arranged at intervals along the radial direction; and the cross-sectional shape of the groove is rectangular.

5. The ceramic-metal combined turbine guide vane according to claim 1, characterized in that: The air film holes are made by electrical machining or laser drilling.

6. A gas turbine, characterized in that: A ceramic-metal combined turbine guide vane comprising the ceramic-metal combined turbine guide vane according to any one of claims 1 to 5.

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