Design method of turbine bearing support structure for high temperature conditions

Abstract

The present invention relates to the technical field of aeroengine and gas turbine design, and discloses a turbine bearing support structure and a design method thereof for high temperature conditions, wherein the bearing support is arranged in the turbine stator blade cavity along the radial direction of the turbine stator blade to form a turbine bearing frame to support the turbine rotor and transmit the radial force of the rotor; the heat-bearing parts and the force-bearing parts are functionally separated to ensure the rigidity of the bearing frame. In addition, the present invention constructs a bearing support rigidity analysis model, a circumferential clearance analysis model, and a bearing support radial height analysis model based on the basic parameters of the turbine bearing support structure to analyze and obtain the number of bearing supports and the size of a single bearing support that meet the rigidity requirements, thereby filling the gap in the system design process of the turbine bearing support structure, improving the deficiency that the determination of the basic structural parameters in the traditional scheme design needs to rely on personal experience, greatly improving the design efficiency, reducing the number of repeated iterations, and realizing the rapid optimization of the turbine bearing support structure.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengine and gas turbine design, and discloses a turbine load-bearing strut structure used in high-temperature conditions and a design method thereof. Background Art

[0002] The turbine bearing frame is an important part of the entire engine bearing system, and the bearing strut is an important component of the turbine bearing frame. The working stability of the bearing strut directly affects the stiffness of the entire bearing frame, and the stiffness of the bearing frame is the basic guarantee for the safe operation of the engine.

[0003] In the prior art, the load-bearing support is set between the inner and outer casings. The load-bearing support must bear not only the radial force, but also the thermal stress caused by the high temperature thermal environment, which greatly reduces the rigidity of the load-bearing frame. In addition, the design structural parameters of the existing turbine load-bearing support scheme are determined by relying on personal experience, lacking engineering design methods, and failing to achieve fast and high-precision design. Summary of the invention

[0004] The purpose of the present invention is to provide a turbine load-bearing strut structure and a design method thereof for use under high temperature conditions, which can ensure the rigidity of the load-bearing frame and improve the deficiency that the determination of basic structural parameters in traditional design schemes needs to rely on personal experience, greatly improve the design efficiency, reduce the number of repeated iterations, and realize the rapid optimization of the turbine load-bearing strut structure.

[0005] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0006] A turbine load-bearing support structure for high temperature conditions includes a load-bearing support, which is arranged in a turbine stator blade cavity, one end of which is fixedly connected to the outer wall of an inner casing, and the other end of which is fixedly connected to the inner wall of an outer casing; the load-bearing support is arranged along the radial direction of the turbine stator blade, and a gap is provided between the outer wall of the load-bearing support and the inner wall of the turbine stator blade cavity.

[0007] Furthermore, the number of the load-bearing struts is at least three, and the load-bearing struts are evenly distributed in the turbine stator blade cavities at corresponding positions along the circumference of the aircraft engine.

[0008] Furthermore, the load-bearing support is a hollow tubular structure, and a pipeline system for lubricating the fulcrum is arranged inside the hollow tubular structure of the load-bearing support.

[0009] Furthermore, the outer casing is provided with a pin hole at a position connected to the load-bearing support, and a pin sleeve is fixed in the pin hole; the load-bearing support and the outer casing are connected by the pin sleeve and bolts to form a turbine load-bearing frame.

[0010] In order to achieve the above technical effects, the present invention provides a method for designing a turbine bearing support structure for high temperature conditions, the method being used to obtain the turbine bearing support structure, comprising:

[0011] According to the structure of the aircraft engine turbine stator and its pivot bearing, a finite element analysis model of the turbine bearing support structure is constructed;

[0012] Under different working conditions, finite element simulation analysis is used to obtain the radial load of the fulcrum bearing corresponding to different numbers of bearing pillars and the cross-sectional area of ​​a single bearing pillar;

[0013] According to the radial load of the fulcrum bearing and the corresponding number of load-bearing pillars and the cross-sectional area of ​​a single load-bearing pillar, a load-bearing pillar stiffness analysis model is constructed;

[0014] Obtain the minimum clearance value of the air system design of the turbine stator blade cavity of the aircraft engine, as well as the manufacturing error of the inner profile of the turbine stator blade and the manufacturing error of the outer surface of the load-bearing support; according to the temperature value of the turbine stator blade cavity under the working state of the aircraft engine, analyze and obtain the maximum thermal deformation of the inner profile of the turbine stator blade and the circumferential thermal deformation of the load-bearing support;

[0015] According to the minimum clearance value of the air system design, the manufacturing error of the inner profile of the turbine stator blade, the manufacturing error of the outer surface of the load-bearing support, the maximum thermal deformation of the inner profile of the turbine stator blade and the circumferential thermal deformation of the load-bearing support, a circumferential clearance analysis model between the load-bearing support and the turbine stator blade cavity is constructed;

[0016] Based on the temperature difference between the outer casing and the bearing support in the working state, and the matching relationship between the inner cylindrical surface of the outer casing and the outer cylindrical surface of the bearing support, a radial height analysis model of the bearing support considering the radial elongation of the bearing support is constructed;

[0017] Obtain the design value of the radial load of the fulcrum bearing of the turbine bearing strut structure to be designed, substitute the design value of the radial load of the fulcrum bearing into the bearing strut stiffness analysis model, and solve it jointly with the circumferential clearance analysis model and the bearing strut radial height analysis model to obtain the number of bearing struts and the size of a single bearing strut that meet the stiffness requirements.

[0018] Furthermore, the load-bearing pillar stiffness analysis model constructed is ,in is the load factor, is the radial load of the pivot bearing, is the local operating temperature of the inner casing The linear expansion coefficient of the lower material, The local working temperature of the load-bearing support The linear expansion coefficient of the lower material, is the local operating temperature of the outer casing The linear expansion coefficient of the lower material; is the inner casing radius, is the design effective working length of the load-bearing support, is the outer casing radius; For the pressure load acting on the inner casing cavity, is the pressure load acting on the outer casing cavity; is the cross-sectional moment of inertia of the inner casing, is the moment of inertia of the cross section of the outer casing; is the elastic modulus of the inner casing material, is the elastic modulus of the bearing support material, is the elastic modulus of the outer casing material; is the cross-sectional area of ​​the inner casing, is the cross-sectional area of ​​the load-bearing support, is the cross-sectional area of ​​the outer casing, is the number of load-bearing pillars.

[0019] Furthermore, the circumferential clearance analysis model between the load-bearing support and the turbine stator blade cavity is constructed as follows: ,in is the minimum circumferential clearance between the load-bearing support and the turbine stator blade cavity, Design minimum clearance values ​​for air systems, is the maximum thermal deformation of the inner surface of the turbine stator blade, is the circumferential thermal deformation of the load-bearing pillar, is the manufacturing error of the inner surface of the turbine stator blade, It is the manufacturing error of the outer surface of the load-bearing support.

[0020] Furthermore, the load-bearing support radial height analysis model considering the radial elongation of the load-bearing support is constructed as follows: ,in The local working temperature of the load-bearing support The linear expansion coefficient of the lower material, is the design effective working length of the load-bearing support, is the load factor, is the radial load of the pivot bearing, is the elastic modulus of the bearing support material, is the cross-sectional area of ​​the load-bearing support.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention arranges the load-bearing pillars in the turbine stator blade cavity along the radial direction of the turbine stator blades, so that the turbine stator blades as heat-bearing parts directly work in high-temperature combustion gas, and the load-bearing pillars as force-bearing parts pass through the turbine stator blade cavity, thereby functionally separating the heat-bearing parts and the force-bearing parts, and ensuring the rigidity of the load-bearing frame.

[0023] 2. The present invention constructs a bearing pillar stiffness analysis model, a circumferential clearance analysis model, and a bearing pillar radial height analysis model based on the basic parameters of the turbine bearing pillar structure, and obtains the number of bearing pillars and the size of a single bearing pillar that meet the stiffness requirements through joint analysis. This fills the gap in the system design process of the turbine bearing pillar structure, improves the deficiency that the determination of basic structural parameters in the traditional scheme design needs to rely on personal experience, greatly improves the design efficiency, reduces the number of repeated iterations, and realizes the rapid optimization of the turbine bearing pillar structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of a method for designing a turbine bearing support structure for high temperature conditions in an embodiment;

[0025] Figure 2 This is a schematic diagram of a turbine bearing support structure used under high temperature conditions in an embodiment;

[0026] Figure 3 It is a schematic diagram of the position relationship between the load-bearing support, the turbine stator blades and the piping system in the embodiment;

[0027] Among them, 1. load-bearing pillar; 2. turbine stator blades; 3. cavity; 4. inner casing; 5. outer casing; 6. piping system; 7. pin sleeve; 8. bolt. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the embodiments and drawings. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0029] Example

[0030] See also Figure 1-Figure 3 , a turbine load-bearing support structure for high temperature conditions, including a load-bearing support 1, wherein the load-bearing support 1 is arranged in the cavity 3 of the turbine stator blade 2, wherein one end of the load-bearing support 1 is fixedly connected to the outer wall of the inner casing 4, and the other end is fixedly connected to the inner wall of the outer casing 5; the load-bearing support 1 is arranged radially along the turbine stator blade 2, and a gap is arranged between the outer wall of the load-bearing support 1 and the inner wall of the cavity 3 of the turbine stator blade 2.

[0031] In this embodiment, the load-bearing strut 1 is radially arranged in the cavity 3 of the turbine stator blade 2 along the turbine stator blade 2, so that one end of the load-bearing strut 1 is fixedly connected to the outer wall of the inner casing 4, and the other end is fixedly connected to the inner wall of the outer casing 5, so as to form a turbine load-bearing frame to support the turbine rotor and transmit the radial force of the rotor; wherein the turbine stator blade 2 is a heat-bearing part directly working in the high-temperature combustion gas, and the load-bearing strut 1 is a force-bearing part passing through the cavity 3 of the turbine stator blade 2, so as to functionally separate the heat-bearing part and the force-bearing part, thereby ensuring the rigidity of the load-bearing frame.

[0032] The number of the load-bearing struts 1 in this embodiment is at least three, and the load-bearing struts 1 are evenly distributed in the cavities 3 of the turbine stator blades 2 at corresponding positions along the circumference of the aircraft engine, ensuring the uniformity of the force on the load-bearing frame formed by the load-bearing struts 1.

[0033] In this embodiment, the load-bearing support 1 is a hollow tubular structure, and a pipeline system 6 for fulcrum lubrication is arranged inside the hollow tubular structure of the load-bearing support 1. By passing the pipeline system 6 through the inner cavity of the load-bearing support 1, the fulcrum lubrication system requirements are met.

[0034] In this embodiment, the outer casing 5 is provided with a pin hole at the position where it is connected to the load-bearing pillar 1, and a pin sleeve 7 is fixed in the pin hole; the load-bearing pillar 1 and the outer casing 5 are connected by the pin sleeve 7 and the bolt 8 to form a turbine load-bearing frame; by utilizing the connection form of the pin sleeve 7 + bolt 8, the pin sleeve 7 bears the force, and the bolt 8 is connected for centering, thereby functionally separating the force bearing and the connection centering.

[0035] Based on the same inventive concept, this embodiment also provides a design method for a turbine bearing support structure for high temperature conditions, and the specific design process is as follows:

[0036] Step 1: According to the structure of the aircraft engine turbine stator and its pivot bearing, a finite element analysis model of the turbine load-bearing strut 1 structure is constructed.

[0037] Step 2: Under different working conditions, finite element simulation analysis is used to obtain the radial load of the fulcrum bearing corresponding to different numbers of load-bearing pillars 1 and the cross-sectional area of ​​a single load-bearing pillar 1.

[0038] Step 3: construct a stiffness analysis model of the load-bearing pillar 1 according to the radial load of the fulcrum bearing and the corresponding number of load-bearing pillars 1 and the cross-sectional area of ​​a single load-bearing pillar 1;

[0039] In this embodiment, the stiffness analysis model of the load-bearing pillar 1 constructed is ,in is the load factor, is the radial load of the pivot bearing, is the local operating temperature of the inner casing 4 The linear expansion coefficient of the lower material, The local working temperature of the load-bearing support 1 at the load-bearing support 1 The linear expansion coefficient of the lower material, is the local operating temperature of the outer casing 5 at the outer casing 5 The linear expansion coefficient of the lower material; is the radius of the inner casing 4, is the designed effective working length of the load-bearing support 1, is the radius of the outer casing 5; To act on the 4 chamber pressure loads in the inner casing, is the cavity pressure load acting on the outer casing 5; is the moment of inertia of the cross section of the inner casing 4, is the moment of inertia of the cross section of the outer casing 5; is the elastic modulus of the inner casing 4 material, is the elastic modulus of the material of the load-bearing support 1, is the elastic modulus of the outer casing 5 material; is the cross-sectional area of ​​the inner casing 4, is the cross-sectional area of ​​the load-bearing support 1, is the cross-sectional area of ​​the outer casing 5, is the number of load-bearing pillars 1.

[0040] Step 4: Obtain the minimum clearance value of the air system design of the cavity 3 of the aircraft engine turbine stator blade 2, as well as the manufacturing error of the inner surface of the turbine stator blade 2 and the manufacturing error of the outer surface of the load-bearing support 1; according to the temperature value of the cavity 3 of the turbine stator blade 2 under the working state of the aircraft engine, analyze and obtain the maximum thermal deformation of the inner surface of the turbine stator blade 2 and the circumferential thermal deformation of the load-bearing support 1.

[0041] Step 5: According to the minimum clearance value of the air system design, the manufacturing error of the inner surface of the turbine stator blade 2, the manufacturing error of the outer surface of the load-bearing support 1, the maximum thermal deformation of the inner surface of the turbine stator blade 2, and the circumferential thermal deformation of the load-bearing support 1, a circumferential clearance analysis model between the load-bearing support 1 and the cavity 3 of the turbine stator blade 2 is constructed;

[0042] In this embodiment, the constructed clearance analysis model between the load-bearing support 1 and the cavity 3 of the turbine stator blade 2 in the circumferential direction is: ,in is the minimum value of the circumferential clearance between the load-bearing support 1 and the cavity 3 of the turbine stator blade 2, Design minimum clearance values ​​for air systems, is the maximum thermal deformation of the inner surface of the turbine stator blade 2, is the circumferential thermal deformation of the load-bearing support 1, is the manufacturing error of the inner surface of the turbine stator blade 2, is the manufacturing error of the outer surface of the load-bearing support 1.

[0043] Step 6: Based on the temperature difference between the outer casing 5 and the load-bearing pillar 1 in the working state, and the matching relationship between the inner cylindrical surface of the outer casing 5 and the outer cylindrical surface of the load-bearing pillar 1, a radial height analysis model of the load-bearing pillar 1 considering the radial elongation of the load-bearing pillar 1 is constructed;

[0044] In this embodiment, the radial height analysis model of the load-bearing support 1 considering the radial elongation of the load-bearing support 1 is constructed as follows: ,in The local working temperature of the load-bearing support 1 at the load-bearing support 1 The linear expansion coefficient of the lower material, is the designed effective working length of the load-bearing support 1, is the load factor, is the radial load of the pivot bearing, is the elastic modulus of the material of the load-bearing support 1, is the cross-sectional area of ​​load-bearing support 1.

[0045] Step seven, obtain the design value of the radial load of the fulcrum bearing of the turbine bearing strut 1 structure to be designed, substitute the design value of the radial load of the fulcrum bearing into the stiffness analysis model of the bearing strut 1, and solve it together with the circumferential clearance analysis model and the radial height analysis model of the bearing strut 1 to obtain the number of bearing struts 1 and the size of a single bearing strut 1 that meet the stiffness requirements.

[0046] In this embodiment, by constructing a bearing support 1 stiffness analysis model, a circumferential clearance analysis model, and a bearing support 1 radial height analysis model based on the basic parameters of the turbine bearing support 1 structure, the number of bearing supports 1 that meet the stiffness requirements and the size of a single bearing support 1 are obtained through joint analysis. This fills the gap in the system design process of the turbine bearing support 1 structure, improves the deficiency of the traditional scheme design that the determination of basic structural parameters needs to rely on personal experience, greatly improves the design efficiency, reduces the number of repeated iterations, and realizes the rapid optimization of the turbine bearing support 1 structure.

[0047] The above are only 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 in the protection scope of the present invention.

Claims

1. A method for designing a turbine load-bearing support structure for high temperature conditions, wherein the load-bearing support is arranged in a turbine stator blade cavity, one end of the load-bearing support is fixedly connected to the outer wall of an inner casing, and the other end is fixedly connected to the inner wall of an outer casing; the load-bearing support is arranged along the radial direction of the turbine stator blade, and a gap is arranged between the outer wall of the load-bearing support and the inner wall of the turbine stator blade cavity; characterized in that: include: According to the structure of the aircraft engine turbine stator and its pivot bearing, a finite element analysis model of the turbine bearing support structure is constructed; Under different working conditions, finite element simulation analysis is used to obtain the radial load of the fulcrum bearing corresponding to different numbers of bearing pillars and the cross-sectional area of ​​a single bearing pillar; According to the radial load of the fulcrum bearing and the corresponding number of bearing pillars and the cross-sectional area of ​​a single bearing pillar, a bearing pillar stiffness analysis model is constructed. ,in is the load factor, is the radial load of the pivot bearing, is the local operating temperature of the inner casing The linear expansion coefficient of the lower material, The local working temperature of the load-bearing support The linear expansion coefficient of the lower material, is the local operating temperature of the outer casing The linear expansion coefficient of the lower material; is the inner casing radius, is the design effective working length of the load-bearing support, is the outer casing radius; For the pressure load acting on the inner casing cavity, is the pressure load acting on the outer casing cavity; is the cross-sectional moment of inertia of the inner casing, is the moment of inertia of the cross section of the outer casing; is the elastic modulus of the inner casing material, is the elastic modulus of the bearing support material, is the elastic modulus of the outer casing material; is the cross-sectional area of ​​the inner casing, is the cross-sectional area of ​​the load-bearing support, is the cross-sectional area of ​​the outer casing, is the number of load-bearing pillars; Obtain the minimum clearance value of the air system design of the turbine stator blade cavity of the aircraft engine, as well as the manufacturing error of the inner profile of the turbine stator blade and the manufacturing error of the outer surface of the load-bearing support; according to the temperature value of the turbine stator blade cavity under the working state of the aircraft engine, analyze and obtain the maximum thermal deformation of the inner profile of the turbine stator blade and the circumferential thermal deformation of the load-bearing support; According to the minimum clearance value of the air system design, the manufacturing error of the inner profile of the turbine stator blade, the manufacturing error of the outer surface of the load-bearing support, the maximum thermal deformation of the inner profile of the turbine stator blade and the circumferential thermal deformation of the load-bearing support, a circumferential clearance analysis model between the load-bearing support and the turbine stator blade cavity is constructed; Based on the temperature difference between the outer casing and the bearing support in the working state, and the matching relationship between the inner cylindrical surface of the outer casing and the outer cylindrical surface of the bearing support, a radial height analysis model of the bearing support considering the radial elongation of the bearing support is constructed; Obtain the design value of the radial load of the fulcrum bearing of the turbine bearing strut structure to be designed, substitute the design value of the radial load of the fulcrum bearing into the bearing strut stiffness analysis model, and solve it jointly with the circumferential clearance analysis model and the bearing strut radial height analysis model to obtain the number of bearing struts and the size of a single bearing strut that meet the stiffness requirements.

2. The turbine bearing support structure design method according to claim 1, characterized in that: The constructed clearance analysis model between the load-bearing support and the turbine stator blade cavity in the circumferential direction is ,in is the minimum circumferential clearance between the load-bearing support and the turbine stator blade cavity, Design minimum clearance values ​​for air systems, is the maximum thermal deformation of the inner surface of the turbine stator blade, is the circumferential thermal deformation of the load-bearing pillar, is the manufacturing error of the inner surface of the turbine stator blade, It is the manufacturing error of the outer surface of the load-bearing support.

3. The turbine bearing support structure design method according to claim 1, characterized in that: The load-bearing support radial height analysis model considering the radial elongation of the load-bearing support is constructed as follows: ,in The local working temperature of the load-bearing support The linear expansion coefficient of the lower material, is the design effective working length of the load-bearing support, is the load factor, is the radial load of the pivot bearing, is the elastic modulus of the bearing support material, is the cross-sectional area of ​​the load-bearing support.

4. The turbine bearing support structure design method according to claim 1, characterized in that: The number of the load-bearing struts is at least three, and the load-bearing struts are evenly distributed in the turbine stator blade cavities at corresponding positions along the circumference of the aircraft engine.

5. The turbine bearing support structure design method according to claim 1, characterized in that: The load-bearing support is a hollow tubular structure, and a pipeline system for lubricating the fulcrum is arranged inside the hollow tubular structure of the load-bearing support.

6. The turbine bearing support structure design method according to claim 1, characterized in that: The outer casing is provided with a pin hole at a position where it is connected to the load-bearing support, and a pin sleeve is fixed in the pin hole; the load-bearing support and the outer casing are connected by the pin sleeve and bolts to form a turbine load-bearing frame.

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