Anti-vibration wear-resistant low-pressure rotor last-stage blade of steam turbine

Abstract

The utility model discloses a kind of low-pressure rotor last stage blade of steam turbine of anti-vibration wear resistance, belong to steam turbine technical field, including blade root, blade body, damping boss and wear-resistant insert, blade body is set on blade root, damping boss is set on blade body, wear-resistant insert is set on the steam inlet edge of blade body, cavity is set inside blade body, cavity inside is provided with free damping block, damping boss is Z type shape, multiple damping bosses are tightly occluded, form a solid, continuous annular damping structure, greatly improve the overall rigidity and self-vibration frequency of blade group, to improve its anti-vibration capacity, wear-resistant insert is fixed on the top end area of steam inlet edge of blade body by brazing or laser cladding process, and it is covered in steam inlet edge, water erosion area on blade body is protected by wear-resistant insert, improve the wear resistance effect of blade body, by cavity and its inside free damping block cooperation, further improve the anti-vibration effect of blade.

Description

Technical Field

[0001] This utility model relates to the field of steam turbine technology, and more specifically, to a vibration-resistant and wear-resistant secondary and final stage blade for a low-pressure rotor of a steam turbine. Background Technology

[0002] Steam turbines, especially the low-pressure rotors of large power plant turbines, operate in extremely harsh environments, with their last and second-to-last stage blades. Currently, the second-to-last stage blades of low-pressure turbine rotors operate in a low-pressure, high-humidity steam environment for extended periods, and must withstand centrifugal forces and vibration loads generated by high-speed rotation. Existing technologies face two major challenges:

[0003] 1. Insufficient vibration resistance: Traditional blades mostly use T-shaped blade roots to connect with rotor grooves, resulting in a small contact area and weak vibration damping ability. Long-term operation can easily lead to blade root fatigue cracks, affecting the safety of the unit.

[0004] 2. Poor wear resistance and water erosion resistance: The blade surface is mostly treated with ordinary polishing. Water droplets in the high humidity steam in the low pressure area can easily cause erosion of the blade, resulting in blade profile distortion, reduced aerodynamic efficiency, and shortened blade service life. Utility Model Content

[0005] In view of the problems existing in the prior art, the purpose of this utility model is to provide a vibration-resistant and wear-resistant secondary and final stage blade for a low-pressure rotor of a steam turbine, which aims to solve the problems mentioned in the background art.

[0006] To solve the above problems, the present invention adopts the following technical solution:

[0007] A vibration-resistant and wear-resistant secondary and final stage blade for a low-pressure turbine rotor, comprising:

[0008] Leaf roots;

[0009] The main body of the leaf is located at the leaf base;

[0010] Also includes:

[0011] Damping bosses are installed on the blade body to resist vibration;

[0012] Wear-resistant inserts are installed on the air inlet edge of the blade body to improve the wear resistance of the blade body; and

[0013] The blade body has a cavity inside, and a free damping block is installed inside the cavity.

[0014] As a preferred embodiment of this utility model, the damping boss and the blade body are integrally formed. After the blade body is assembled on the rotor, multiple damping bosses abut against each other to form a continuous annular damping structure.

[0015] As a preferred embodiment of this utility model, the wear-resistant insert is made of Stellite alloy material and has an "L" shaped cross section.

[0016] As a preferred embodiment of this utility model, the free damping block is a damping block made of high specific gravity alloy, and the outer diameter of the free damping block is smaller than the inner diameter of the cavity.

[0017] In a preferred embodiment of this utility model, a medium channel is provided on the outer wall of the leaf root, and the medium channel is connected to the cavity.

[0018] As a preferred embodiment of this utility model, the damping medium in the medium channel is either low-temperature steam or oil mist.

[0019] Beneficial effects

[0020] Compared with existing technologies, this utility model provides a vibration-resistant and wear-resistant secondary and final stage blade for a low-pressure turbine rotor, which has the following beneficial effects:

[0021] 1. In this design, the damping boss is Z-shaped. After the blade body is installed on the rotor through the blade root, multiple Z-shaped damping bosses are tightly interlocked to form a very robust and continuous annular damping structure, which greatly improves the overall rigidity and natural frequency of the blade assembly, thereby improving its vibration resistance. The wear-resistant insert is fixed to the top area of ​​the steam inlet edge on the blade body by brazing or laser cladding and covers the steam inlet edge. The wear-resistant insert protects the water erosion area on the blade body and improves the wear resistance of the blade body. The vibration resistance of the blade is further improved by the cavity and its internal free damping block.

[0022] 2. In this scheme, multiple free damping blocks are provided, and they are spherical in shape. The outer dimensions of the free damping blocks are smaller than the inner wall dimensions of the cavity, so that there is an active gap between the free damping blocks and the inner wall of the cavity for them to move freely. When the blade body vibrates, the cavity moves accordingly, and the free damping blocks inside will lag behind the movement of the cavity due to inertia, thus causing discontinuous collisions with the cavity wall. Each collision converts a part of the blade's vibration kinetic energy into sound energy and heat energy, thereby suppressing vibration. Attached Figure Description

[0023] Figure 1 This is a perspective view of the present utility model;

[0024] Figure 2 This is a second-view perspective perspective view of the present invention;

[0025] Figure 3 This is a cross-sectional view of the present invention.

[0026] Explanation of the labels in the diagram:

[0027] 1. Blade root; 2. Blade body; 3. Damping boss; 4. Wear-resistant insert; 5. Cavity; 6. Free damping block; 7. Medium channel. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0029] Example:

[0030] Please see Figure 1-3 A vibration-resistant and wear-resistant low-pressure rotor secondary and final stage blade for a steam turbine includes a blade root 1, a blade body 2, a damping boss 3, and a wear-resistant insert 4. The blade body 2 is disposed on the blade root 1, the damping boss 3 is disposed on the blade body 2 for vibration resistance, and the wear-resistant insert 4 is disposed on the steam inlet edge of the blade body 2 to improve the wear resistance of the blade body 2. A cavity 5 is provided inside the blade body 2, and a free damping block 6 is disposed inside the cavity 5.

[0031] In this embodiment, the damping boss 3 is Z-shaped. After the blade body 2 is installed on the rotor through the blade root 1, multiple "Z"-shaped damping bosses 3 are tightly interlocked to form a very robust and continuous annular damping structure, which greatly improves the overall rigidity and natural frequency of the blade assembly, thereby improving its vibration resistance. The wear-resistant insert 4 is fixed to the top area of ​​the steam inlet edge on the blade body 2 by brazing or laser cladding process and covers the steam inlet edge. The wear-resistant insert 4 protects the water erosion area on the blade body 2 and improves the wear resistance of the blade body 2. The vibration resistance of the blade is further improved by the cooperation of the cavity 5 and its internal free damping block 6.

[0032] Please refer to the specific details. Figure 1-3 As shown, the damping boss 3 and the blade body 2 are integrally machined; after the blade body 2 is assembled on the rotor, multiple damping bosses 3 abut against each other to form a continuous annular damping structure.

[0033] In this embodiment, the damping boss 3 and the blade body 2 are integrally machined, which improves the stability of the damping boss 3 and makes it easier to use.

[0034] Please refer to the specific details. Figure 2 As shown, the wear-resistant insert 4 is made of Stellite alloy material, and the cross-section of the wear-resistant insert 4 is "L" shaped.

[0035] In this embodiment, the wear-resistant insert 4 is made of Stellite alloy, which has good corrosion resistance and high temperature resistance, thus improving its protective effect. The wear-resistant insert 4 has an "L" shaped cross section, which facilitates the protection of the steam inlet edge on the blade body 2.

[0036] Please refer to the specific details. Figure 1 and Figure 3 As shown, the free damping block 6 is a damping block made of high specific gravity alloy, and the outer diameter of the free damping block 6 is smaller than the inner diameter of the cavity 5.

[0037] In this embodiment, multiple free damping blocks 6 are provided, and they are spherical in shape. The outer dimensions of the free damping blocks 6 are smaller than the inner wall dimensions of the cavity 5, so that there is an active gap between the free damping blocks 6 and the inner wall of the cavity 5 for them to move freely. When the blade body 2 vibrates, the cavity 5 moves accordingly, and the free damping blocks 6 inside will lag behind the movement of the cavity 5 due to inertia, thus causing discontinuous collisions with the cavity wall. Each collision converts a part of the blade's vibration kinetic energy into sound energy and heat energy, thereby suppressing vibration.

[0038] Please refer to the specific details. Figure 1 and Figure 3 As shown, a medium channel 7 is provided on the outer wall of the leaf root 1, and the medium channel 7 is connected to the cavity 5.

[0039] In this embodiment, the damping medium is conveniently injected into the cavity 5 through the medium channel 7, which further improves the vibration resistance of the blade.

[0040] Please refer to the specific details. Figure 3 As shown, the damping medium in the medium channel 7 is either low-temperature steam or oil mist.

[0041] In this embodiment, the damping medium can be low-temperature steam. Steam is the working medium of the steam turbine. Even if there is a slight leakage, it will be directly mixed into the main steam flow, posing zero risk to the safe operation of the unit and improving the safety of use.

[0042] Working principle: During use, the blade body 2 is installed onto the turbine rotor via the blade root 1, and multiple damping bosses 3 are tightly interlocked to form a very robust and continuous annular damping structure, which improves the overall rigidity and natural frequency of the blade assembly, thereby enhancing its vibration resistance. Wear-resistant inserts protect the water erosion zone at the steam inlet edge of the blade body, improving the wear resistance of the blade body. A cavity 5 is set inside the blade body 2, and a free damping block 6 is set inside the cavity 5. During the vibration of the blade body 2, the cavity 5 moves accordingly, while the free damping block 6 inside will lag behind the movement of the cavity 5 due to inertia, thus causing discontinuous collisions with the cavity wall. Each collision converts a portion of the blade's vibration kinetic energy into sound energy and heat energy, thereby suppressing vibration. Damping medium is conveniently injected into the cavity 5 through the medium channel 7, further improving the blade's vibration resistance.

[0043] The control method of this utility model is to control the device by manually starting and stopping the switch. The wiring diagram of the power element and the supply of power are common knowledge in the field. Since this utility model is mainly used to protect mechanical devices, the control method and wiring layout will not be explained in detail.

[0044] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model based on the technical solution and its improved concept should be covered within the protection scope of the present utility model.

Claims

1. A vibration-resistant and wear-resistant secondary and final stage blade for a low-pressure rotor of a steam turbine, comprising: Leaf root (1); The main body of the leaf (2) is set on the leaf root (1); Its characteristic is that it further includes: Damping boss (3) is provided on the blade body (2) and is used to resist vibration; Wear-resistant inserts (4) are provided on the steam inlet edge of the blade body (2) to enhance the wear resistance of the blade body (2); and The blade body (2) has a cavity (5) inside, and a free damping block (6) is provided inside the cavity (5).

2. The vibration-resistant and wear-resistant secondary and final stage blade of a low-pressure turbine rotor according to claim 1, characterized in that, The damping boss (3) and the blade body (2) are integrally formed; after the blade body (2) is assembled on the rotor, multiple damping bosses (3) abut against each other to form a continuous annular damping structure.

3. The vibration-resistant and wear-resistant secondary and final stage blade of a low-pressure turbine rotor according to claim 2, characterized in that, The wear-resistant insert (4) is made of Stellite alloy material and has an "L" shaped cross section.

4. The vibration-resistant and wear-resistant secondary and final stage blade of a low-pressure turbine rotor according to claim 3, characterized in that, The free damping block (6) is a damping block made of high specific gravity alloy, and the outer diameter of the free damping block (6) is smaller than the inner diameter of the cavity (5).

5. The vibration-resistant and wear-resistant secondary and final stage blade of a low-pressure turbine rotor according to claim 4, characterized in that, The outer wall of the leaf root (1) is provided with a medium channel (7), and the medium channel (7) is connected to the cavity (5).

6. The vibration-resistant and wear-resistant secondary and final stage blade of a low-pressure turbine rotor according to claim 5, characterized in that, The damping medium in the medium channel (7) is either low-temperature steam or oil mist.

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