Turbine guide blade margin plate step control structure and design method thereof

Abstract

The invention relates to the technical field of aero-engine and gas turbine design, and discloses a turbine guide blade margin plate step control structure and a design method thereof.A partitioned limiting block structure is adopted to be arranged at the position of a lower margin plate of two adjacent turbine guide blades, and the lower margin plate and a limiting block are matched with each other through the radial limiting characteristic; and the radial deformation of the lower edge plates of the adjacent turbine guide blades is limited. The problem that due to the fact that the step difference exists on the runner faces of the lower edge plates of the adjacent turbine guide blades, pneumatic loss of main runner airflow is generated at the step position is avoided, and the pneumatic integrity of the runner where the adjacent turbine guide blades are located is enhanced; meanwhile, the problem that the thermal deformation stress of the turbine guide blade is large due to deformation of a lower margin plate when whole ring limiting is adopted is avoided; in addition, radial positioning of the limiting block is only restrained by the blade margin plate, the limiting block can move in the radial direction along with the blade margin plate during working, and large deformation stress caused by the fact that the turbine guide blade is restrained by an inner casing is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengine and gas turbine design, and discloses a turbine guide blade edge plate step control structure and a design method thereof. Background Art

[0002] The turbine guide vanes bear the structural function of the aerodynamic flow surface. When working, they will produce thermal deformation incoordination under the combined effect of aerodynamic force and thermal stress. In existing designs, turbine guide vanes are usually designed as block structures to reduce the thermal deformation incoordination of the turbine guide vane blade body and inner and outer edge plates under high temperature. Thermal deformation incoordination will also lead to inconsistent radial deformation of different parts of the blade. The difference in radial deformation of the turbine guide vanes with a block structure on the back side of the edge plate and the basin side of the edge plate will cause adjacent turbine guide vanes to form a step difference at the edge plate. The existence of this step difference will destroy the integrity of the flow path and cause non-design losses to the aerodynamic performance of the turbine. Summary of the invention

[0003] The object of the present invention is to provide a step control structure for a turbine guide vane edge plate and a design method thereof, which can avoid the problem of aerodynamic losses of the main flow channel airflow at the step position due to the step difference in the flow channel surface of the lower edge plates of adjacent turbine guide blades, thereby enhancing the aerodynamic integrity of the flow channel where the adjacent turbine guide blades are located; and can avoid the large deformation stress caused by the turbine guide blades being constrained by the inner casing.

[0004] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0005] A turbine guide blade edge plate step control structure, comprising:

[0006] A limit block, wherein the limit block is arranged between lower edge plates of two adjacent turbine guide blades;

[0007] A radial limiting feature is provided between the limiting block and the lower edge plate, and is used for radially limiting the limiting block.

[0008] Furthermore, it also includes a boss, which is arranged on the lower edge plate of the turbine guide blade and protrudes along the axial direction of the aircraft engine; the limit block is a positioning petal ring installed on the axial end face of the lower edge plate of the turbine guide blade, and at least one positioning hole is opened on the positioning petal ring along the axial direction of the aircraft engine, and the positioning hole is plugged into a boss in the lower edge plate of the adjacent turbine guide blade, and a circumferential gap is set between two adjacent limit blocks.

[0009] Furthermore, the radial limiting feature includes a slot and a plug-in that cooperate with each other.

[0010] Furthermore, the slot comprises a groove provided on the lower edge plate of the turbine guide blade, and the plug-in is a hanging ring provided on the limit block and matched with the groove.

[0011] Furthermore, the hanging ring on each limit block is simultaneously connected to the grooves on the lower edge plates of two adjacent turbine guide blades.

[0012] In order to achieve the above technical effects, the present invention also provides a method for designing a turbine guide blade edge plate step control structure, the method being used to obtain a lower limit value of a circumferential clearance value range between two adjacent limit blocks in the turbine guide blade edge plate step control structure, comprising:

[0013] According to the number of turbine guide blades, the circumferential length of the lower edge plate of a single turbine guide blade is obtained by analysis;

[0014] According to the working temperature of the matching position of the lower edge plate of the turbine guide blade and the limit block, the linear expansion coefficient of the turbine guide blade material and the linear expansion coefficient of the limit block, the difference between the circumferential deformation of the limit block and the circumferential deformation of the lower edge plate corresponding to the limit block under different working conditions is analyzed and obtained;

[0015] According to the difference between the circumferential deformation of the limit block and the circumferential deformation of a single adjacent lower edge plate under different working states, the maximum value of the difference is determined as the lower limit value of the circumferential gap between two adjacent limit blocks.

[0016] Furthermore, the circumferential deformation of the limit block under different working conditions is L1=α1L(T i -T0), where T i is the working temperature of the matching position between the lower edge plate of the turbine guide blade and the stopper under the i-th working state, α1 is the temperature of the stopper material from T0 to T i The linear expansion coefficient, L is the circumferential fitting length between the limit block and the lower edge plate corresponding to the limit block, T0 is the room temperature, which is 20°C.

[0017] Furthermore, the circumferential deformation of a single lower edge plate L2 = α2L y (T i -T0), where L y is the circumferential length of the lower edge plate, D is the inner ring diameter of the positioning valve ring, N is the number of turbine guide blade rings, and α2 is the material of the turbine guide blade from T0 to T i The linear expansion coefficient.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention adopts a block-type limit block structure to be set at the lower edge plate position of two adjacent turbine guide blades, and adopts a radial limit feature to achieve the mutual cooperation between the lower edge plate and the limit block, so as to limit the radial deformation of the lower edge plates of adjacent turbine guide blades. It has a simple structure and good assembly performance, and can realize the control of the flow channel deformation of the turbine guide blade edge plate, avoids the problem of aerodynamic loss of the main flow channel at the step position due to the step difference on the flow channel surface of the lower edge plates of adjacent turbine guide blades, and enhances the aerodynamic integrity of the flow channel where the adjacent turbine guide blades are located.

[0020] 2. The present invention also avoids the problem of large thermal deformation stress of the turbine guide blades caused by deformation of the lower edge plate when using a full-ring limiter; in addition, since the radial positioning of the limit block is only constrained by the blade edge plate, the limit block can move radially with the blade edge plate during operation, thereby avoiding the large deformation stress caused by the turbine guide blades being constrained by the inner casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A three-dimensional diagram of a step control structure for a turbine guide blade edge plate in Example 1;

[0022] Figure 2 A schematic diagram of a step control structure for a turbine guide blade edge plate in Embodiment 1 or 2;

[0023] Figure 3 A three-dimensional diagram of a turbine guide blade edge plate step control structure in Example 2;

[0024] Figure 4 is a three-dimensional diagram of the limit block in Example 2;

[0025] Among them, 1. boss; 2. lower edge plate; 3. limit block; 4. positioning hole; 5. groove; 6. hanging ring. DETAILED DESCRIPTION

[0026] 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.

[0027] Example 1

[0028] See also Figure 1-Figure 2 , a turbine guide vane edge plate step control structure, comprising:

[0029] A limit block 3, wherein the limit block 3 is arranged between two adjacent turbine guide blade lower edge plates 2;

[0030] The radial limiting feature is arranged between the limiting block 3 and the lower edge plate 2 and is used to limit the limiting block 3 in the radial direction.

[0031] In the present embodiment, a block-type limit block 3 structure is adopted to be arranged at the position of the lower edge plate 2 of two adjacent turbine guide blades, and a radial limit feature is adopted to realize the mutual cooperation between the lower edge plate 2 and the limit block 3, so as to limit the radial deformation of the lower edge plate 2 of the adjacent turbine guide blades. It has a simple structure and good assembly performance, and can realize the control of the flow channel deformation of the turbine guide blade edge plate, thereby avoiding the problem of aerodynamic loss of the main flow channel at the step position due to the step difference in the flow channel surface of the lower edge plate 2 of the adjacent turbine guide blades, and enhancing the aerodynamic integrity of the flow channel where the adjacent turbine guide blades are located; at the same time, the limit block 3 only limits the radial deformation of the two adjacent turbine guide blades, and the block structure has low thermal stress, thereby avoiding the problem of large thermal deformation stress of the turbine guide blade caused by the deformation of the lower edge plate 2 when the full ring limit is adopted; in addition, since the radial positioning of the limit block 3 is only constrained by the blade edge plate, the limit block 3 can move radially with the blade edge plate during operation, thereby avoiding the large deformation stress caused by the turbine guide blade being constrained by the inner casing.

[0032] In this embodiment, it also includes a boss 1, which is arranged on the lower edge plate 2 of the turbine guide blade, and the boss 1 protrudes along the axial direction of the aircraft engine; the radial limiting feature includes a slot and a plug-in that cooperate with each other, the slot can be a groove 5 opened on the lower edge plate 2 of the turbine guide blade, and the plug-in is a hanging ring 6 arranged on the limiting block 3 and capable of cooperating with the groove 5; the hanging ring 6 on each limiting block 3 is simultaneously connected with the groove 5 on the lower edge plates 2 of two adjacent turbine guide blades. When the thermal deformation of the turbine guide blade is not coordinated, the adjacent turbine guide blades are constrained by the cooperation of the hanging ring 6 and the groove 5, which improves the overall cooperation stability between the limiting block 3 and the lower edge plate 2. Similarly, other radial limiting features (such as limiting convex strips, etc.) that can realize radial limiting of the limiting block 3 are also applicable to the present invention.

[0033] It should be noted that the step control structure for the turbine guide blade edge plate in the present embodiment is applicable to the situation where the linear expansion coefficients of the limit block 3 and the turbine guide blade are close. Under this condition, there is no need to consider the circumferential deformation on both sides of the limit block 3. The circumferential positioning of the limit block 3 can be automatically achieved simply by inserting the limit block 3 between adjacent protrusions. At this time, the limit block 3 has good follow-up performance to the deformation of the turbine guide blade, while taking into account the assembly performance of the two.

[0034] Example 2

[0035] See also Figure 2-Figure 4 In view of the large difference in linear expansion coefficient between the stop block 3 and the turbine guide blade, this embodiment provides another step control structure for the turbine guide blade edge plate, including:

[0036] A boss 1, wherein the boss 1 is arranged on a lower edge plate 2 of a turbine guide blade, and the boss 1 protrudes along the axial direction of the aircraft engine;

[0037] A limit block 3 is provided between two adjacent turbine guide blade lower edge plates 2; the limit block 3 is a positioning petal ring installed on the axial end surface of the turbine guide blade lower edge plate 2, and at least one positioning hole 4 is provided on the positioning petal ring along the axial direction of the aircraft engine, and the positioning hole 4 is plugged into a boss 1 in the adjacent turbine guide blade lower edge plate 2, and a circumferential gap is provided between two adjacent limit blocks 3.

[0038] When the linear expansion coefficient of the stop block 3 and the turbine guide blade is greatly different, the circumferential deformation of the stop block 3 and the turbine guide blade under different temperature conditions will be large, which will lead to an increase in thermal stress at a local position of the turbine blade, and easily cause extrusion deformation of adjacent turbine guide blades, thereby resulting in a strength reserve or shortened life of the turbine guide blade. In this embodiment, by providing a positioning hole 4 on the stop block 3, the boss 1 of the lower edge plate 2 of the turbine guide blade is plugged into the positioning hole 4 to achieve circumferential positioning of the stop block 3. At the same time, the positioning petal ring structure will have a certain circumferential gap between two adjacent stop blocks 3. The circumferential gap can coordinate the problem of inconsistent circumferential deformation of the stop block 3 and the turbine guide blade, thereby reducing the probability of increased thermal stress at a local position of the turbine blade.

[0039] Based on the same inventive concept, this embodiment also provides a method for designing a turbine guide blade edge plate step control structure, which is used to obtain the lower limit value of the circumferential clearance value range between two adjacent limit blocks 3 in the turbine guide blade edge plate step control structure; comprising:

[0040] According to the number of turbine guide blades, the circumferential length of the lower edge plate 2 of a single turbine guide blade is obtained by analysis;

[0041] According to the working temperature of the matching position of the lower edge plate 2 of the turbine guide blade and the limit block 3, the linear expansion coefficient of the turbine guide blade material and the linear expansion coefficient of the limit block, the difference between the circumferential deformation of the limit block 3 and the circumferential deformation of the lower edge plate 2 corresponding to the limit block under different working conditions is analyzed and obtained;

[0042] According to the difference between the circumferential deformation of the limit block 3 and the circumferential deformation of a single adjacent lower edge plate 2 under different working states, the maximum value of the difference is determined as the lower limit of the circumferential gap between two adjacent limit blocks 3.

[0043] In this embodiment, the lower limit value of the circumferential gap between two adjacent limit blocks 3 is min =Max(ΔL i ), ΔL i It is the difference between the circumferential deformation of the limit block 3 and the circumferential deformation of a single adjacent lower edge plate 2 in the i-th working state.

[0044] In this embodiment, the circumferential deformation of the limit block 3 under different working conditions is L1=α1L(T i -T0), where T i is the working temperature of the matching position between the lower edge plate 2 of the turbine guide blade and the stopper 3 in the i-th working state, α1 is the temperature of the material of the stopper 3 from T0 to T i The linear expansion coefficient, L is the circumferential fitting length between the limit block 3 and the lower edge plate 2 corresponding to the limit block 3, T0 is the room temperature, which is 20°C.

[0045] Circumferential deformation of a single lower edge plate 2 L2 = α2L y (T i -T0), where L y is the circumferential length of the lower edge plate 2, D is the inner ring diameter of the positioning valve ring, N is the number of turbine guide blade rings, and α2 is the material of the turbine guide blade from T0 to T i The linear expansion coefficient.

[0046] In this embodiment, the difference between the working temperature and the room temperature under different working conditions of the matching position of the lower edge plate 2 of the turbine guide blade and the limit block 3, as well as the linear expansion coefficient of the limit block 3 material and the turbine guide blade material and related structural dimensions are comprehensively considered, so as to analyze and obtain the lower limit value of the circumferential gap between two adjacent limit blocks 3, so as to achieve effective control of the thermal deformation of the turbine guide blade during operation and ensure the coordination of adjacent turbine blades.

[0047] The other parts of this embodiment are the same as those of Embodiment 1 and will not be described in detail here.

[0048] 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 step control structure for a turbine guide blade edge plate, characterized in that: include: A limit block, wherein the limit block is arranged between lower edge plates of two adjacent turbine guide blades; A radial limiting feature is provided between the limiting block and the lower edge plate, and is used for radially limiting the limiting block.

2. The step control structure for turbine guide blade edge plate according to claim 1, characterized in that: It also includes a boss, which is arranged on the lower edge plate of the turbine guide blade and protrudes along the axial direction of the aircraft engine; the limit block is a positioning petal ring installed on the axial end face of the lower edge plate of the turbine guide blade, and at least one positioning hole is opened on the positioning petal ring along the axial direction of the aircraft engine, and the positioning hole is plugged into a boss in the lower edge plate of the adjacent turbine guide blade, and a circumferential gap is set between two adjacent limit blocks.

3. The step control structure for turbine guide blade edge plate according to claim 1 or 2, characterized in that: The radial limiting feature includes a slot and a plug-in that cooperate with each other.

4. The step control structure for turbine guide vane edge plate according to claim 3, characterized in that: The slot comprises a groove formed on the lower edge plate of the turbine guide blade, and the plug-in is a hanging ring arranged on the limiting block and matched with the groove.

5. The turbine guide vane edge plate step control structure according to claim 4, characterized in that: The hanging ring on each limiting block is simultaneously connected with the grooves on the lower edge plates of two adjacent turbine guide blades.

6. A method for designing a turbine guide blade edge plate step control structure, the method being used to obtain the lower limit of the circumferential clearance value range between two adjacent limit blocks in the turbine guide blade edge plate step control structure as claimed in claim 2, characterized in that: include: According to the number of turbine guide blades, the circumferential length of the lower edge plate of a single turbine guide blade is obtained by analysis; According to the working temperature of the matching position of the lower edge plate of the turbine guide blade and the limit block, the linear expansion coefficient of the turbine guide blade material and the linear expansion coefficient of the limit block, the difference between the circumferential deformation of the limit block and the circumferential deformation of the lower edge plate corresponding to the limit block under different working conditions is analyzed and obtained; According to the difference between the circumferential deformation of the limit block and the circumferential deformation of a single adjacent lower edge plate under different working states, the maximum value of the difference is determined as the lower limit value of the circumferential gap between two adjacent limit blocks.

7. The method for designing a turbine guide vane edge plate step control structure according to claim 6, characterized in that: The circumferential deformation of the limit block under different working conditions is L1=α1L(T i -T0), where T i is the working temperature of the matching position between the lower edge plate of the turbine guide blade and the stopper under the i-th working state, α1 is the temperature of the stopper material from T0 to T i The linear expansion coefficient of the stop block is L, the circumferential fitting length between the stop block and the lower edge plate corresponding to the stop block, and T0 is the room temperature, which is 20°C.

8. The method for designing a turbine guide vane edge plate step control structure according to claim 7, characterized in that: Circumferential deformation of a single lower edge plate L2 = α2L y (T i -T0), where L y is the circumferential length of the lower edge plate, D is the inner ring diameter of the positioning valve ring, N is the number of turbine guide blade rings, and α2 is the material of the turbine guide blade from T0 to T i The linear expansion coefficient.

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