Turbine blade structure

Abstract

The utility model provides a steam turbine blade structure, which belongs to the field of steam turbine blades and comprises a casing, a steam pipe and a blade shaft, the steam pipe is fixedly connected with the casing, the blade shaft is arranged on the inner side of the casing, a plurality of fixing seats are sleeved on the blade shaft, and a plurality of moving blades are fixedly connected onto the fixing seats. A plurality of blade groups are fixedly connected to the inner side wall of the shell, each blade group comprises a plurality of stationary blades, an air injection seat is fixedly connected to the middle position in the length direction of a blade shaft, fixing sleeves are arranged on the two sides of the air injection seat and rotationally connected with the blade shaft, air pipes are fixedly connected to the fixing sleeves, and the air pipes are connected with an external ejector. According to the on-line shot peening strengthening device, an external ejector conveys aluminum oxide particles to the air injection seat through the air pipe, and the aluminum oxide particles are finally ejected out of the air outlet holes in the air injection seat at a high speed to impact the surface of the moving blade to form a pressure stress layer, so that on-line shot peening strengthening is realized, and the anti-fatigue performance of the blade is improved.

Description

Technical Field

[0001] This utility model relates to the field of steam turbine blades, and more specifically, to a steam turbine blade structure. Background Technology

[0002] A steam turbine is a high-speed rotating power machine that converts thermal energy into mechanical energy, widely used in thermal power generation, nuclear power plants, and large-scale industrial drives. Its core principle is that high-temperature, high-pressure steam impacts the blades, driving the rotor to rotate, which in turn drives a generator or mechanical equipment. Steam turbines typically consist of multiple stages of cylinders connected in series, including high-pressure, intermediate-pressure, and low-pressure cylinders. The steam performs work stage by stage during expansion, achieving an efficiency of over 40%. Modern steam turbines employ precision-cast blades, steam reheating, and regenerative cycles, significantly improving energy utilization.

[0003] During operation, the surface of steam turbine blades is subjected to high-speed impact from high-temperature, high-pressure steam over a long period of time, which can easily cause damage. When steam flows through the blade channel at extremely high velocities, the leading edge and pressure surface of the blade are subjected to strong dynamic loads and alternating stresses, leading to gradual erosion wear and microcracks on the material surface, thus reducing the service life of the blade.

[0004] How to design a turbine blade structure to improve these problems has become an urgent issue for those skilled in the art. Utility Model Content

[0005] To overcome the above deficiencies, this utility model provides a turbine blade structure, which aims to improve the problems mentioned in the background.

[0006] This utility model is implemented as follows:

[0007] This utility model provides a steam turbine blade structure, including a shell, a steam pipe, and a blade shaft. The shell is symmetrically arranged on both sides, and both sides of the shell have tapered openings. The steam pipe is fixedly connected to the shell. The blade shaft is located inside the shell, and multiple fixed seats are sleeved on the blade shaft. Multiple moving blades are fixedly connected to the fixed seats. Multiple blade groups are fixedly connected to the inner sidewall of the shell. Each blade group includes multiple stationary blades. An injection seat is fixedly connected to the middle position along the length of the blade shaft. Fixed sleeves are provided on both sides of the injection seat. The fixed sleeves are rotatably connected to the blade shaft. An air pipe is fixedly connected to the fixed sleeve and connected to an external injector. The blade shaft is provided with an inlet groove, multiple second inlet channels, and multiple outlet grooves.

[0008] Preferably, the steam pipe is connected to the shell, the fixed seat is fixedly connected to the blade shaft, and the moving blades are evenly distributed circumferentially on the outer wall of the fixed seat.

[0009] Preferably, both the stationary blades and the moving blades are inclined on the blade shaft, and the distance between adjacent stationary blades on one side in a single blade group is greater than the distance on the other side, with the direction of steam flow being from the side with the larger distance to the side with the smaller distance.

[0010] Preferably, the multiple stationary blades in the blade group are evenly distributed circumferentially on the inner sidewall of the housing, and the fixed seat and the blade group are staggered in the direction of the blade axis.

[0011] Preferably, the air pipe is provided with a first air inlet, and the jet seat is provided with multiple air outlets.

[0012] Preferably, the air inlet groove is located inside the fixed sleeve, the air outlet groove is located inside the air outlet hole, the second air inlet channel is located inside the blade shaft, and the air inlet groove and the air outlet groove are connected through the second air inlet channel.

[0013] Preferably, the air outlet groove is connected to multiple air outlet holes, and the first air inlet channel is connected to the air inlet groove.

[0014] The beneficial effects of this invention are as follows: the external injector delivers alumina particles to the jet seat through the air pipe. The particles pass through the air inlet groove, the second air inlet channel and the air outlet groove in sequence, and are finally ejected at high speed from multiple air outlets on the jet seat, impacting the surface of the moving blade and forming a compressive stress layer. This achieves online shot peening strengthening, improves the fatigue resistance of the blade, and increases the service life of the blade. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a three-dimensional structural diagram of a steam turbine blade provided by an embodiment of the present invention;

[0017] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0018] Figure 3 This is a schematic diagram of a turbine blade fixing sleeve structure provided by an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of a turbine blade structure and blade shaft structure provided by an embodiment of the present invention.

[0020] In the diagram: 1. Shell; 2. Steam pipe; 3. Blade shaft; 4. Fixing seat; 5. Moving blade; 6. Stationary blade; 11. Fixing sleeve; 12. Air pipe; 121. First air inlet; 13. Jet seat; 131. Air outlet; 31. Air inlet groove; 32. Second air inlet; 33. Air outlet groove. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0022] Example, refer to Figures 1-4 A turbine blade structure includes a casing 1, a steam pipe 2, and a blade shaft 3. The casing 1 is symmetrically arranged on both sides, and both sides of the casing 1 have tapered openings. The steam pipe 2 is fixedly connected to the casing 1. The blade shaft 3 is located inside the casing 1, and multiple fixing seats 4 are sleeved on the blade shaft 3. Multiple moving blades 5 are fixedly connected to the fixing seats 4. Multiple blade groups, each containing multiple stationary blades 6, are fixedly connected to the inner wall of the casing 1. An injection seat 13 is fixedly connected to the middle position along the length of the blade shaft 3. Fixing sleeves 11 are provided on both sides of the injection seat 13, and the fixing sleeves 11 are rotatably connected to the blade shaft 3. Air pipes 12 are fixedly connected to the fixing sleeves 11 and are connected to an external injector. The blade shaft 3 is provided with an inlet groove 31, multiple second inlet passages 32, and multiple outlet grooves 33. The steam pipe 2 communicates with the casing 1, and the fixing seats 4 are fixedly connected to the blade shaft 3. The moving blades 5 are evenly distributed circumferentially on the outer wall of the fixed base 4. The stationary blades 6 and the moving blades 5 are both inclined on the blade shaft 3. In a single blade group, the distance between one side of adjacent stationary blades 6 is greater than the distance on the other side. The direction of steam flow is from the side with the larger distance to the side with the smaller distance. Multiple stationary blades 6 in the blade group are evenly distributed circumferentially on the inner wall of the shell 1. The fixed base 4 and the blade group are staggered in the direction of the blade shaft 3. The air pipe 12 is provided with a first air inlet 121. The jet seat 13 is provided with multiple air outlets 131. The air inlet groove 31 is located inside the fixed sleeve 11. The air outlet groove 33 is located inside the air outlet 131. The second air inlet 32 ​​is located inside the blade shaft 3. The air inlet groove 31 and the air outlet groove 33 are connected through the second air inlet 32. The air outlet groove 33 is connected to multiple air outlets 131. The first air inlet 121 is connected to the air inlet groove 31.

[0023] It should be noted that since the jet holder 13 is fixed to the blade shaft 3 and rotates with it, when the gas-solid two-phase flow containing alumina particles enters the jet holder 13 through the gas pipe 12, the particles are ejected from multiple outlet holes 131 in a spiral trajectory as the jet holder 13 rotates. This rotating jetting method allows the particles to be evenly distributed over a larger area, avoiding concentrated jetting in only one direction, thus ensuring that each moving blade 5 surface receives sufficient and uniform particle impact.

[0024] The working principle of this turbine blade structure is as follows: This turbine blade structure achieves functional expansion by introducing a particle injection system on the basis of a traditional turbine. During operation, high-temperature and high-pressure steam enters the casing 1 through the steam pipe 2, flows through the stationary blades 6 for guidance, and then impacts the moving blades 5, driving the blade shaft 3 to rotate to complete energy conversion. The external injector mixes micron-sized particles such as alumina with the carrier gas and then delivers them to the jet seat 13 through the gas pipe 12. The particles pass through the inlet groove 31, the second inlet duct 32, and the outlet groove 33 in sequence, and are finally ejected at high speed from multiple outlet holes 131 on the jet seat 13, impacting the surface of the moving blades 5 to form a compressive stress layer, realizing online shot peening strengthening, improving the fatigue resistance of the blades, and increasing the service life of the blades.

[0025] It should be noted that the use of external injectors for spraying alumina particles is a mature and widely used existing technology, commonly found in surface treatment and strengthening processes across various industrial sectors. The external injector is responsible for providing a stable supply of alumina particles. The powerful kinetic energy generated by the high-pressure steam flow inside the turbine accelerates these particles and effectively impacts the blade surface. When the airflow containing alumina particles enters the blade shaft 3 and passes through the inlet slot 31 and the second inlet duct 32 to reach the outlet slot 33, they are ultimately released into the high-speed steam environment through multiple outlet holes 131 on the injector seat 13.

[0026] Alumina particles impact the blade surface at high speed, causing localized plastic deformation and generating elastic deformation in the underlying material, leaving residual compressive stress. This compressive stress helps resist externally applied tensile stress, thus effectively inhibiting the initiation and propagation of cracks.

[0027] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A steam turbine blade structure, comprising a casing (1), a steam pipe (2), and a blade shaft (3), characterized in that, The shell (1) is symmetrically arranged on both sides, and both sides of the shell (1) are tapered. The steam pipe (2) is fixedly connected to the shell (1). The blade shaft (3) is located inside the shell (1). Multiple fixed seats (4) are sleeved on the blade shaft (3). Multiple moving blades (5) are fixedly connected on the fixed seats (4). Multiple blade groups are fixedly connected to the inner wall of the shell (1). The blade groups include multiple stationary blades (6). A jet seat (13) is fixedly connected at the middle position of the blade shaft (3) in the length direction. Fixed sleeves (11) are provided on both sides of the jet seat (13). The fixed sleeves (11) are rotatably connected to the blade shaft (3). An air pipe (12) is fixedly connected to the fixed sleeve (11). The air pipe (12) is connected to an external injector. An air inlet groove (31), multiple second air inlets (32), and multiple air outlet grooves (33) are provided on the blade shaft (3).

2. The turbine blade structure according to claim 1, characterized in that, The steam pipe (2) is connected to the shell (1), the fixed seat (4) is fixedly connected to the blade shaft (3), and the moving blades (5) are evenly distributed circumferentially on the outer wall of the fixed seat (4).

3. The turbine blade structure according to claim 1, characterized in that, The stationary blades (6) and moving blades (5) are both inclined on the blade shaft (3). In a single set of blades, the distance between one side of adjacent stationary blades (6) is greater than the distance between the other side, and the direction of steam flow is from the side with the larger distance to the side with the smaller distance.

4. A turbine blade structure according to claim 1, characterized in that, The multiple stationary blades (6) in the blade group are evenly distributed in a circle on the inner sidewall of the housing (1), and the fixed seat (4) and the blade group are staggered in the direction of the blade shaft (3).

5. A turbine blade structure according to claim 1, characterized in that, The air pipe (12) is provided with a first air inlet (121), and the jet seat (13) is provided with multiple air outlets (131).

6. A turbine blade structure according to claim 5, characterized in that, The air inlet groove (31) is located inside the fixed sleeve (11), the air outlet groove (33) is located inside the air outlet hole (131), the second air inlet channel (32) is located inside the blade shaft (3), and the air inlet groove (31) and the air outlet groove (33) are connected through the second air inlet channel (32).

7. A turbine blade structure according to claim 6, characterized in that, The air outlet groove (33) is connected to a plurality of air outlet holes (131), and the first air inlet (121) is connected to the air inlet groove (31).

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