Turbine guider mounting edge heat preservation structure

Abstract

The invention belongs to the field of aero-engine gas turbines, and provides a turbine guider mounting edge heat preservation structure which comprises a heat insulation cover and a supporting ring, the supporting ring is fixed to the mounting edge of a turbine guider and an exhaust casing, one end of the heat insulation cover is connected with the supporting ring, and the other end of the heat insulation cover is connected with the supporting ring. And the other end is lapped on the turbine case. An annular cavity is defined by the heat insulation cover, the supporting ring and the turbine case, an air inlet hole communicated with the annular cavity is formed in the heat insulation cover, and an air outlet hole communicated with the annular cavity is formed in the supporting ring. The heat preservation structure does not influence original performance indexes of turbine parts, influences on external culvert performance parameters are small, the structure is easy to adjust, the machining cost is low, the service life of the turbine guider is greatly prolonged, and the improvement effect is remarkable.

Description

Technical Field

[0001] The present invention belongs to the technical field of aero-engine gas turbines, and relates to a thermal insulation structure for a turbine guide vane mounting flange. Background Art

[0002] When designing a small engine, it is required that the engine has characteristics such as low cost, small size, light weight, practical performance, long life, high reliability, and good maintainability. In order to improve efficiency, reduce weight, and lower costs, the turbine component usually adopts a design method in which the low-pressure turbine guide vane directly bears the load to provide support and constraint for the rotor system. The turbine guide vane generally consists of guide vanes and inner and outer flange plates. The mounting flange of the outer flange plate of the guide vane is connected to the turbine casing by bolts and positioned by a radial stop. Some of the guide vanes are hollow structures, and the lubricating oil pipeline passes through them. The guide vanes and the inner and outer flange plates are located in the mainstream passage position and are in direct contact with the gas, without active cooling measures, so the temperature is relatively high. The remaining components are located outside the mainstream passage, and cooling air flows through them, so the temperature is relatively low. When the engine is working, the temperature in the mainstream passage of the turbine component varies in the range of 500 - 1150K, and the temperature of the turbine guide vane mounting flange varies in the range of 200 - 400K. Due to the influence of factors such as temperature gradient, structure, and load transfer, there are differences in the thermal deformation of the inner and outer flange plates and the guide vanes of the turbine guide vane, which will lead to the phenomenon of inconsistent deformation. High thermal stress will appear in the high stress concentration areas at the tip and root of the trailing edge of the blade, and fatigue cracks are extremely likely to occur under the action of thermal fatigue, resulting in the service life of the turbine guide vane not meeting the design requirements. Summary of the Invention

[0003] In order to solve the technical problem that the existing turbine guide vane causes fatigue cracks due to inconsistent deformation and high stress concentration during operation, resulting in the service life of the turbine guide vane not meeting the design requirements, the present invention discloses a thermal insulation structure for a turbine guide vane mounting flange. The thermal insulation structure for the turbine guide vane mounting flange includes a heat insulation cover and a support ring. The support ring is fixed on the mounting flange between the turbine guide vane and the exhaust casing. One end of the heat insulation cover is connected to the support ring, and the other end overlaps on the turbine casing.

[0004] A ring cavity is formed among the heat insulation cover, the support ring, and the turbine casing. An air inlet hole communicating with the ring cavity is formed on the heat insulation cover, and an air outlet hole communicating with the ring cavity is formed on the support ring.

[0005] Further, the heat insulation cover is arc-shaped or S-shaped. One end of the heat insulation cover contacts the outer wall surface of the turbine casing, the other end of the heat insulation cover is connected to the outer wall surface of the support ring, and a plurality of the air inlet holes are circumferentially formed in the middle of the heat insulation cover.

[0006] Furthermore, the other end of the heat insulation cover is welded to the support ring, and a plurality of exhaust holes are circumferentially formed at the top of the heat insulation cover.

[0007] Further, one end of the heat shield connected to the support ring extends to form an extension section, and an open annular cavity is formed between the extension section and the outer wall of the mounting edge.

[0008] Further, the support ring includes a vertical section, an arc transition section, and a horizontal section. The vertical section is fixed to the mounting edge by connecting bolts. The horizontal section is connected to the heat shield, and a plurality of the air outlet holes are circumferentially formed in the arc transition section.

[0009] Further, the air inlet hole is circular, the air outlet hole is square, and the centers of the air inlet hole and the air outlet hole do not coincide.

[0010] Further, both the heat shield and the support ring are formed by a plurality of fan-shaped blocks, and the fan-shaped blocks are fixed to the mounting edge by connecting bolts.

[0011] Compared with the prior art, the at least one technical solution adopted in the embodiments of this specification can achieve at least the following beneficial effects: Without changing the original structure of the turbine guide vane, by assembling a heat insulation cover structure on the mounting edge of the turbine guide vane, the present invention appropriately changes the air flow distribution ratio of the cold air in the outer bypass duct flowing through the mounting edge of the turbine guide vane, increases the temperature of the mounting edge of the turbine guide vane and the turbine casing connected thereto, reduces the radial temperature gradient of the turbine guide vane, and further reduces the thermal stress at the trailing edge of the turbine guide vane blade and the fillet of the inner cavity, thereby increasing the service life of the turbine guide vane.

[0012] The heat insulation structure provided by the present invention does not affect the original performance indicators of the turbine components, has little influence on the outer bypass performance parameters, has a simple structure adjustment, low processing cost, greatly increases the service life of the turbine guide vane, and has a remarkable improvement effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0014] Figure 1 Schematic diagram of the heat insulation structure of the mounting edge of the turbine guide vane disclosed in the embodiments of the present invention;

[0015] Figure 2 Installation diagram of the heat insulation structure of the mounting edge of the turbine guide vane disclosed in the embodiments of the present invention;

[0016] Figure 3 Stereogram of the heat insulation structure of the mounting edge of the turbine guide vane disclosed in the embodiments of the present invention and the cutting position of the fan-shaped block;

[0017] Among them, 1. Turbine casing; 2. Turbine guide vane; 3. Connecting bolt; 4. Exhaust casing; 6. Heat insulation cover; 7. Support ring; 100. Annular cavity; 200. Open annular cavity; 61. Air inlet hole; 62. Air outlet hole; 71. Air outlet hole; 72. Vertical section; 73. Arc transition section; 74. Horizontal section. Specific implementation manners

[0018] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0019] The following uses specific specific examples to illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features of the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts fall within the scope of protection of the present application.

[0020] In the description of the present embodiment, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0021] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0022] It should also be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present disclosure in a schematic manner. The components shown in the drawings only show the components related to the present disclosure and are not drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0023] An embodiment of the present invention discloses a thermal insulation structure for the installation edge of a turbine guide vane. Refer to Figure 1 and Figure 2 As shown, the thermal insulation structure for the installation edge of the turbine guide vane includes a heat insulation cover 6 and a support ring 7. Among them, both the heat insulation cover 6 and the support ring 7 are annular parts. The support ring 7 is fixed on the installation edge of the turbine guide vane 2 and the exhaust casing 4. One end of the heat insulation cover 6 is connected to the support ring 7, and the other end overlaps on the turbine casing 1. Through this installation edge thermal insulation structure, the axial air flow in the outer flow path is separated from the installation edge of the turbine guide vane.

[0024] Refer to Figure 2 As shown, a ring cavity 100 is formed by enclosing the heat insulation cover 6, the support ring 7 and the turbine casing 1. An air inlet hole 61 communicating with the ring cavity 100 is opened on the heat insulation cover 6, and an air outlet hole 71 communicating with the ring cavity 100 is opened on the support ring 7. Cold air enters the ring cavity 100 through the air inlet hole 61, and after heat exchange, it is discharged through the air outlet hole 71. By controlling the number and hole parameters of the air inlet hole 61 and the air outlet hole 71, the air flow rate in the ring cavity 100 can be controlled.

[0025] During specific implementation, the axial distance between the heat insulation cover 6 and the support ring 7 can be adjusted, that is, the axial length of the ring cavity 100 is adjusted, the heat transfer coefficient between the air flow in the ring cavity 100 and the solid wall surface is changed, the temperature of the turbine casing 1 is adjusted, and further the extrusion force of the turbine casing on the stop of the installation edge of the turbine guide vane is adjusted. For example, by increasing the axial length of the ring cavity 100, the temperature of the turbine casing at the corresponding axial distance can be increased, and the extrusion force of the turbine casing on the stop of the installation edge of the turbine guide vane can be reduced.

[0026] Furthermore, refer to Figure 1 and Figure 2 As shown, the circumferential profile of the heat insulation cover 6 is designed as an arc or an S shape. One end of the heat insulation cover 6 is in contact with the outer wall surface of the turbine casing 1, and the other end of the heat insulation cover 6 is connected to the outer wall surface of the support ring 7. A plurality of the air inlet holes 61 are circumferentially opened in the middle of the heat insulation cover 6. In this specific implementation manner, by designing the heat insulation cover 6 as an arc or an S shape and making it overlap on the turbine casing 1, most of the oncoming gas in the outer flow path can flow backward along the outer surface of the heat insulation cover 6, preventing a large amount of cold flow in the outer flow path from forming forced convection heat transfer to the installation edge, reducing the convective heat transfer coefficient of the installation edge, reducing the influence of the cold flow in the outer flow path on the installation edge, and at the same time hindering the cold air flow from impacting the surface of the turbine casing 1.

[0027] Even further, the other end of the heat insulation cover 6 is welded to the support ring 7.

[0028] Furthermore, exhaust holes 62 can be circumferentially formed at the top of the heat shield 6. Through the exhaust holes 62, the cold air in the annular cavity 100 can flow out along the outer wall surface of the heat shield 6. Meanwhile, by adjusting the size, quantity, and shape of the exhaust holes 62, the amount of cold air in the annular cavity 100 can be controlled, so that the temperature of the mounting edge is within the expected design temperature range. In addition, the arrangement of the exhaust holes 62 can also facilitate the insertion of installation tools to tighten the connection bolts 3 when installing the support ring 7.

[0029] Furthermore, as shown in Figure 2 FIG. [5], one end of the heat shield 6 connected to the support ring 7 extends to form an extension section. The extension section and the outer wall of the mounting edge form an open annular cavity 200. Through the design of the extension section, the cold air discharged from the annular cavity 100 can be concentrated in the open annular cavity 200 formed on the outer wall of the mounting edge to control the temperature of the mounting edge within a predetermined temperature range. Meanwhile, by adjusting the quantity, shape, and position of the air inlet holes 61 and the air outlet holes 71, the distribution of the cooling air in the annular cavity 100 and the open annular cavity 200 can be realized to control the temperature of the mounting edge of the turbine guide vane.

[0030] During specific implementation, the length of the extension section can be adjusted to regulate the flow heat transfer at the rear side of the support ring 7, so as to control the temperature of the mounting edge within the expected temperature range.

[0031] Furthermore, as shown in Figure 1 FIG.

[13] , the circumferential profile of the support ring 7 is designed as an inverted "L" shape, including a vertical section 72, an arc transition section 73, and a horizontal section 74. The vertical section 72 is fixed to the mounting edge through the connection bolts 3 for support and positioning. The horizontal section 74 is connected to the heat shield 6, and a plurality of the air outlet holes 71 are circumferentially formed on the arc transition section 73.

[0032] Furthermore, the air inlet holes 61 are circular, the air outlet holes 71 are square, and the centers of the air inlet holes 61 and the air outlet holes 71 do not coincide.

[0033] Furthermore, during specific implementation, in order to release the radial extrusion force of the turbine casing 1 on the support ring 7 and the heat shield 6, as shown in Figure 3 FIG.

[21] , both the heat shield 6 and the support ring 7 are formed by a plurality of fan-shaped blocks. The fan-shaped blocks are fixed to the mounting edge through the connection bolts 3. During processing, the heat shield 6 and the support ring 7 can be respectively designed as a whole, then welded into one body, and then cut into at least two fan-shaped blocks.

[0034] In the present invention, the parameters affecting the temperature T of the mounting edge are shown in the following formula (1):

[0035] T = f(h f , T f , λ), in formula (1): hf is the heat transfer coefficient of the installation edge wall surface of the turbine guide vane; T f is the fluid temperature of the wall surface of the turbine guide vane; λ is the solid thermal conductivity.

[0036] During design, the more the number of the air inlet holes 61, the exhaust holes 62 and the air outlet holes 71, the larger the flow area, and the shorter the heat insulation cover 6, the heat transfer coefficient h between the air flow in the annular cavity 100 and the solid wall surface f is larger, and the temperature of the installation edge is lower. By adjusting parameters such as the number, flow area and length of the air inlet holes 61, the exhaust holes 62 and the air outlet holes 71, the temperature of the installation edge can be controlled.

[0037] On the basis of not changing the original structure of the turbine guide vane, the present invention assembles a heat insulation cover structure on the installation edge of the turbine guide vane, appropriately changes the air flow distribution ratio of the cold air in the outer bypass duct flowing through the installation edge of the turbine guide vane, improves the temperature of the installation edge of the turbine guide vane and the turbine casing connected thereto, reduces the radial temperature gradient of the turbine guide vane, and further reduces the thermal stress at the trailing edge of the turbine guide vane blade and the fillet of the inner cavity, thereby improving the service life of the turbine guide vane.

[0038] The heat insulation structure provided by the present invention does not affect the original performance indexes of the turbine components, has little influence on the performance parameters of the outer bypass, has simple structural adjustment and low processing cost, greatly improves the service life of the turbine guide vane, and has obvious improvement effect.

[0039] Obviously, those skilled in the art should understand that the above description is only the preferred embodiments of the present invention and is not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the embodiments of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0040] In addition, it should be understood that although this specification is described according to the embodiments, not each embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A thermal insulation structure for the installation edge of a turbine guide vane, characterized in that, It includes a heat shield (6) and a support ring (7). The support ring (7) is fixed on the installation edge of the turbine guide vane (2) and the exhaust casing (4). One end of the heat shield (6) is connected to the support ring (7), and the other end is lapped on the turbine casing (1). A ring cavity (100) is formed by the heat shield (6), the support ring (7) and the turbine casing (1). An air inlet hole (61) communicating with the ring cavity (100) is formed on the heat shield (6), and an air outlet hole (71) communicating with the ring cavity (100) is formed on the support ring (7).

2. The insulation structure of the turbine guide vane installation edge according to claim 1, wherein The heat shield (6) is arc-shaped or S-shaped. One end of the heat shield (6) contacts the outer wall surface of the turbine casing (1), the other end of the heat shield (6) is connected to the outer wall surface of the support ring (7), and a plurality of the air inlet holes (61) are circumferentially formed in the middle of the heat shield (6).

3. The thermal insulation structure of the turbine guide vane installation edge according to claim 2, characterized in that The other end of the heat shield (6) is welded to the support ring (7), and a plurality of exhaust holes (62) are circumferentially formed at the top of the heat shield (6).

4. The insulation structure for the turbine guide vane mounting flange according to claim 1, wherein An extension section is formed at one end of the heat shield (6) connected to the support ring (7), and an open ring cavity (200) is formed between the extension section and the outer wall of the installation edge.

5. The insulation structure for the installation edge of the turbine guide vane according to claim 1, wherein, The support ring (7) includes a vertical section (72), an arc-shaped transition section (73) and a horizontal section (74). The vertical section (72) is fixed on the installation edge through a connecting bolt (3), the horizontal section (74) is connected to the heat shield (6), and a plurality of the air outlet holes (71) are circumferentially formed on the arc-shaped transition section (73).

6. The thermal insulation structure of the turbine guide vane mounting edge according to claim 1, wherein The air inlet hole (61) is circular, the air outlet hole (71) is square, and the centers of the air inlet hole (61) and the air outlet hole (71) do not coincide.

7. The thermal insulation structure of the turbine guide vane installation edge according to claim 1, characterized in that, Both the heat shield (6) and the support ring (7) are formed by a plurality of fan-shaped blocks, and the fan-shaped blocks are fixed on the installation edge through connecting bolts (3).

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