Turbine blade structure and preparation method thereof

Abstract

The invention provides a turbine blade structure and a preparation method thereof, and relates to the technical field of turbine.The turbine blade structure comprises a mounting base, a plurality of mounting holes are formed in the outer side of the mounting base, a plurality of blades are placed in the mounting holes, and first through holes are formed in the ends, located on the inner side of the mounting base, of the blades; the first through holes are connected through connecting rings, and the connecting rings are connected through first bolt assemblies. Blades are placed in the mounting holes and then are connected through the first bolt assemblies of the connecting rings, and therefore the problems that in the background technology, blades of an existing turbine impeller are difficult to disassemble and assemble and inconvenient to maintain and periodically check and replace, the size of the blades of the existing turbine impeller cannot be adjusted, and the size of the blades cannot be adjusted are effectively solved. And the technical problem that blades with different sizes cannot be flexibly used under different use conditions of the steam turbine is solved.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbines, and in particular to a steam turbine blade structure and a preparation method thereof. Background Art

[0002] Steam turbine blades are the general term for the steel used for the moving and stationary blades in steam turbines. Blades are key parts of steam turbines and one of the most delicate and important parts. They withstand high temperature, high pressure, huge centrifugal force, steam force, steam excitation force, corrosion and vibration, and water droplet erosion in the wet steam zone under extremely harsh conditions.

[0003] The existing steam turbine impeller blades are difficult to disassemble and assemble, and are not convenient for maintenance and regular inspection and replacement. In addition, the size of the existing steam turbine impeller blades cannot be adjusted, and it is not flexible to meet the need to use blades of different sizes in different use cases of the steam turbine. Therefore, in view of the above situation, it is urgent to develop a steam turbine blade structure and a preparation method thereof to overcome the shortcomings in current practical applications. Summary of the invention

[0004] The present invention provides a steam turbine blade structure and a preparation method thereof, which are used to solve the technical problems raised in the above-mentioned background technology that the blades of the existing steam turbine impeller are difficult to disassemble and assemble, and are not convenient for maintenance and regular inspection and replacement, and the size of the existing steam turbine impeller blades cannot be adjusted, and it is impossible to flexibly meet the technical problems that the steam turbine needs to use blades of different sizes under different usage conditions.

[0005] In order to solve the above technical problems, the present invention discloses a turbine blade structure, including: a mounting seat, a plurality of mounting holes are arranged on the outer side of the mounting seat, and blades are placed in the mounting holes, and a through hole 1 is arranged at one end of the blade located on the inner side of the mounting seat, and the through holes 1 and 1 are connected by a connecting ring, and the connecting ring is connected by a bolt assembly 1.

[0006] Preferably, the mounting seat is composed of an upper top seat and a lower base, and a plurality of through holes 2 are installed between the upper top seat and the lower base in a one-to-one correspondence, and the through holes 2 are connected by bolt assemblies 2.

[0007] Preferably, a reinforcement layer is fixedly provided on the outer side of the blade, and the reinforcement layer comprises: reinforcement ribs and a filling layer, the reinforcement ribs are hard alloy, and the filling layer is high temperature vulcanized silicone rubber.

[0008] Preferably, the surfaces of the blades are provided with air guide grooves, the surfaces of the blades are covered with ceramic material, and the blades are arc-shaped.

[0009] A method for preparing a steam turbine blade structure comprises the following steps: Step 1: Design the specific shape, size and structural parameters of the blade root, blade body and blade crown according to the performance requirements of the steam turbine; Step 2: Using high temperature alloy material to form the initial shape of the blade through die forging process; Step 3: Use CNC machining equipment to accurately process the blank; Step 4: Shot blast the finished blades to remove surface defects and burrs; Step 5: Assemble the processed blade structure and conduct strict inspection.

[0010] Preferably, in step three, the blades are finely machined using a five-axis CNC surface milling machine.

[0011] Preferably, in step 4, the shot blasting process uses appropriate shot blasting media and process parameters.

[0012] Preferably, in step five, the inspection of the blades includes: size inspection, shape and position tolerance inspection, material property inspection and surface quality inspection.

[0013] Preferably, the detection in step 5 further comprises: Speed ​​sensor, used to detect the speed per second of the turbine blades; Gas flow rate sensor, used to detect the intake speed of turbine gas through the blades; A controller and an alarm, wherein the controller is electrically connected to the rotation speed sensor, the gas flow rate sensor and the alarm, and the controller controls the alarm to work based on the rotation speed sensor and the gas flow rate sensor.

[0014] Preferably, the method for preparing a steam turbine blade structure comprises the following steps: Step 1: According to formula (1), calculate the natural frequency of the turbine blade in the non-rotating state:

[0015] (1); in is the natural frequency coefficient of the blade, is the material property coefficient of the blade, is the geometric shape coefficient of the blade, is the blade support coefficient, is the elastic modulus of the blade material, is the minimum centroid principal moment of inertia of the blade section, is the mass of the blade, is the height of the blade, The value is 3.14; Step 2: Calculate the turbine blade dynamic frequency coefficient according to formula (2) and the speed sensor detection value

[0016] (2); in is the natural frequency of the blade in working condition, is the natural frequency of the blade in the non-rotating state, is the average diameter of the leaves, is the speed sensor detection value, is the angle between turbine blades, is a sine; Step 3: Calculate the actual gap airflow excitation force of the blades during the operation of the turbine according to the following formula (3) and the gas velocity sensor detection value: The controller compares the actual gap airflow excitation force of the blades during the operation of the turbine When the actual gap airflow excitation force exceeds the preset gap airflow excitation force range, the controller controls the alarm to sound an alarm: (3); in is the gas flow rate sensor detection value, is the linear velocity of the blade, is the cosine, is the airflow outlet angle of the blade when it is stationary, is the blade inlet angle, is the gas velocity coefficient, is the blade outlet angle, is the average density of airflow passing through the blades of the steam turbine, is the blade tip radius, is the blade root radius, is the average gap between the blade tips, is the eccentricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A structural front view provided for an embodiment of the present invention; Figure 2 For the present invention Figure 1 A cross-sectional view of the mounting seat structure provided in the embodiment; Figure 3 For the present invention Figure 2 A side view of a blade structure provided in the embodiment; Figure 4 For the present invention Figure 2 An enlarged schematic diagram of the structure at point A provided in the embodiment.

[0019] Reference numerals: 1. Mounting seat; 2. Mounting hole; 3. Blade; 301. Reinforcement layer; 3011. Reinforcement rib; 3012. Filling layer; 4. Through hole one; 5. Connecting ring; 6. Bolt assembly one; 7. Upper top seat; 8. Lower base; 9. Through hole two. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0022] The present invention provides the following embodiments Example 1 The embodiment of the present invention provides a steam turbine blade structure, such as Figure 1-4 As shown, a steam turbine blade structure includes: a mounting seat 1, a plurality of mounting holes 2 are arranged on the outer side of the mounting seat 1, and blades 3 are placed in the mounting holes 2, and a through hole 4 is arranged on one end of the blade 3 located on the inner side of the mounting seat 1, and the through holes 4 are connected to each other through a connecting ring 5, and the connecting ring 5 is connected by a bolt assembly 6.

[0023] Optionally, the mounting seat 1 is composed of an upper top seat 7 and a lower base 8, and a plurality of through holes 9 are installed between the upper top seat 7 and the lower base 8 in a one-to-one correspondence, and the through holes 9 are connected by bolt assemblies 2.

[0024] Optionally, a reinforcement layer 301 is fixedly provided on the outer side of the blade 3, and the reinforcement layer 301 includes: reinforcement ribs 3011 and a filling layer 3012, the reinforcement ribs 3011 are hard alloy, and the filling layer 3012 is high temperature vulcanized silicone rubber.

[0025] Optionally, the surfaces of the blades 3 are provided with air guide grooves, the surfaces of the blades 3 are covered with ceramic material, and the blades 3 are arc-shaped.

[0026] The working principle and beneficial effects of the above technical solution are as follows: by opening the upper top seat 7, then placing the blade 3 into the mounting hole 2, then passing the connecting ring 5 through the through hole 4, and then connecting through the bolt assembly 6, and finally connecting the lower base 8 with the upper top seat 7 through the bolt assembly 2, so as to connect the blade 3 and the mounting seat 1, thereby effectively improving the background technology proposed: the blades of the existing steam turbine impeller are difficult to disassemble and assemble, and are not convenient for maintenance and regular inspection and replacement, and the size of the blades of the existing steam turbine impeller cannot be adjusted, and it is impossible to flexibly meet the technical problem that the steam turbine needs to use blades of different sizes under different usage conditions.

[0027] Example 2 Based on Example 1, a method for preparing a steam turbine blade structure comprises the following steps: Step 1: Design the specific shape, size and structural parameters of blade root, blade body and blade crown of blade 3 according to the performance requirements of the steam turbine; Step 2: Using a high temperature alloy material, a preliminary shape of the blade 3 is formed by die forging to ensure that the blade has sufficient strength and density; Step 3: Use CNC machining equipment to accurately process the blank; Step 4: Shot blasting the finished blade 3 to remove surface defects and burrs, and improve the smoothness and corrosion resistance of the blade; Step 5: Assemble the processed blade 3 structure and conduct strict testing to ensure that the performance indicators of the blade meet the design requirements.

[0028] Optionally, in step three, the blade 3 is finely machined using a five-axis CNC profile milling machine to ensure the accuracy and surface quality of the blade profile.

[0029] Optionally, in step four, the shot blasting process uses appropriate shot blasting media and process parameters to remove surface defects without damaging the base material of the blade.

[0030] Optionally, in step five, the inspection of the blade 3 includes: size inspection, shape and position tolerance inspection, material property inspection and surface quality inspection to ensure the overall performance and reliability of the blade.

[0031] The beneficial effects of the above technical solution are: Customized design: The shape, size and structural parameters of the blade root, blade body and blade crown are designed according to the specific performance requirements of the steam turbine, ensuring the perfect match between the blade 3 and the steam turbine, thereby improving the overall operating efficiency and performance of the steam turbine; High strength and density: The blade 3 is formed into its initial shape by die forging using high-temperature alloy materials. This material selection and processing technology ensure that the blade 3 has sufficient strength and density to withstand the huge stress and heat load generated by the turbine under high-speed rotation and high-temperature and high-pressure environment; High-precision machining: Use CNC machining equipment to accurately machine the blank, especially the use of a five-link CNC profile milling machine for fine machining as mentioned in the optional step. This method can significantly improve the accuracy and surface quality of the blade profile, reduce machining errors, and further improve the performance and service life of the blade 3; Surface quality optimization: Shot blasting is performed on the blade 3 after fine processing to remove surface defects and burrs, improve the smoothness and corrosion resistance of the blade. The use of appropriate shot blasting media and process parameters during the shot blasting process can remove surface defects while avoiding damage to the base material of the blade 3, thereby protecting the integrity and performance of the blade 3; Strict testing and quality assurance: Strict testing is carried out at each stage of blade 3 processing, including size testing, shape and position tolerance testing, material performance testing and surface quality testing. These testing measures ensure that the various performance indicators of blade 3 meet the design requirements and improve the overall performance and reliability of blade 3; Improve efficiency and reduce costs: By optimizing the design, material selection and processing technology of blade 3, as well as strict testing and quality control, this method not only improves the operating efficiency of the turbine, but also helps reduce the maintenance and replacement costs of blade 3 and extend the service life of the turbine.

[0032] Example 3 On the basis of Embodiment 1-2, in the method for preparing a steam turbine blade structure, the detection in step 5 further comprises: A rotation speed sensor, used to detect the rotation speed per second of the turbine blade 3; A gas flow rate sensor, used to detect the intake speed of the turbine gas through the blade 3; A controller and an alarm, wherein the controller is electrically connected to the rotation speed sensor, the gas flow rate sensor and the alarm, and the controller controls the alarm to work based on the rotation speed sensor and the gas flow rate sensor.

[0033] Optionally, a method for preparing a steam turbine blade structure comprises the following steps: Step 1: According to formula (1), calculate the natural frequency of turbine blade 3 in the non-rotating state:

[0034] (1); in is the natural frequency coefficient of blade 3 (the natural frequency of blade 3 is a physical quantity closely related to the blade material, geometry, size and support method, etc. It reflects the natural vibration frequency of the blade in the free vibration state, and the value range is 0.23-0.35), is the material property coefficient of blade 3 (the value range is 0.33-0.56), is the geometric shape coefficient of blade 3 (the range is 0.42-0.51), is the support mode coefficient of blade 3 (the range is 0.17-0.36), is the elastic modulus of the blade 3 material, is the minimum centroidal principal moment of inertia of blade 3 section, is the mass of blade 3, is the height of blade 3, The value is 3.14; Step 2: Calculate the dynamic frequency coefficient of turbine blade 3 according to formula (2) and the speed sensor detection value

[0035] (2); in is the natural frequency of blade 3 in working state, is the natural frequency of blade 3 in the non-rotating state, is the average diameter of blade 3, is the speed sensor detection value, is the angle between turbine blades 3 and 3, is a sine; Step 3: According to the following formula (3) and the gas velocity sensor detection value, calculate the actual gap airflow exciting force of blade 3 during the operation of the turbine: The controller compares the actual gap airflow excitation force of blade 3 during the operation of the turbine When the actual gap airflow excitation force exceeds the preset gap airflow excitation force range, the controller controls the alarm to sound an alarm: (3); in is the gas flow rate sensor detection value, is the linear velocity of blade 3, is the cosine, is the airflow outlet angle of blade 3 in a stationary state, is the blade inlet angle (the angle between the air velocity vector and the axial direction of blade 3 at the inlet of blade 3), is the gas velocity coefficient (the range is 0.23-0.57), is the blade outlet angle (the angle between the air velocity vector and the axial direction of blade 3 at the outlet of blade 3), is the average density of the airflow through the turbine blade 3, is the radius of the blade 3 end, is the root radius of blade 3, is the average gap between the tip of blade 3 and the tip of blade 3, is the eccentricity.

[0036] The beneficial effects of the above technical solution are as follows: the controller calculates the natural frequency of the steam turbine blade 3 in a non-rotating state based on the formula (1), and comprehensively considers the natural frequency coefficient of the blade 3, the material property coefficient of the blade 3, the geometric shape coefficient of the blade 3, the support method coefficient of the blade 3, the elastic modulus of the material of the blade 3, the minimum centroid principal moment of inertia of the cross section of the blade 3, the mass of the blade 3, and the height of the blade 3, so that the calculation result is more accurate and reliable; Then, according to the formula (2) and the speed sensor detection value, the dynamic frequency coefficient of the steam turbine blade 3 is calculated, and the natural frequency of the blade 3 in the working state, the natural frequency of the blade 3 in the non-rotating state, the average diameter of the blade 3, and the angle between the steam turbine blade 3 and the blade 3 are comprehensively considered, so that the calculation result is more accurate and reliable; Finally, according to formula (2) and the detection value of the gas flow rate sensor, the linear velocity of blade 3, the airflow outlet angle of blade 3 in a stationary state, the air inlet angle of the moving blade, the gas velocity coefficient, the air outlet angle of the moving blade, the average density of the airflow through blade 3 of the turbine, the end radius of blade 3, the root radius of blade 3, the average gap between the tip of blade 3 and the tip of blade 3, and the eccentricity, the actual gap airflow exciting force of blade 3 during the operation of the turbine is calculated, so that the calculation result is more accurate and reliable; The controller compares the actual gap airflow excitation force of blade 3 during the operation of the turbine Compared with the preset gap airflow exciting force range, when the actual gap airflow exciting force exceeds the preset gap airflow exciting force range, the controller controls the alarm to sound an alarm, thereby reminding the staff to promptly inspect or replace the turbine blade structure, thereby meeting the user's needs for the turbine blade structure.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A steam turbine blade structure, characterized in that: include: A mounting seat (1), wherein a plurality of mounting holes (2) are arranged on the outside of the mounting seat (1), and blades (3) are placed in the mounting holes (2), and a through hole (4) is arranged at one end of the blade (3) located on the inside of the mounting seat (1), and the through holes (4) and (4) are connected via a connecting ring (5), and the connecting ring (5) is connected via a bolt assembly (6).

2. A steam turbine blade structure according to claim 1, characterized in that: The mounting seat (1) is composed of an upper top seat (7) and a lower base seat (8), and a plurality of through holes (9) are mounted one-to-one between the upper top seat (7) and the lower base seat (8), and the through holes (9) are connected by bolt assemblies (2).

3. A steam turbine blade structure according to claim 1, characterized in that: A reinforcement layer (301) is fixedly arranged on the outer side of the blade (3), the reinforcement layer (301) comprising: reinforcement ribs (3011) and a filling layer (3012), the reinforcement ribs (3011) are hard alloy, and the filling layer (3012) is high-temperature vulcanized silicone rubber.

4. A steam turbine blade structure according to claim 1, characterized in that: The surfaces of the blades (3) are all provided with air guide grooves, the surfaces of the blades (3) are all covered with ceramic material, and the blades (3) are in an arc shape.

5. A method for preparing a steam turbine blade structure, characterized in that: The preparation method is applied to a steam turbine blade structure according to any one of claims 1 to 4, and is characterized in that it comprises the following steps: Step 1: Design the specific shape, size and structural parameters of the blade root, blade body and blade crown of the blade (3) according to the performance requirements of the steam turbine; Step 2: Using a high temperature alloy material, forming a preliminary shape of the blade (3) through a die forging process; Step 3: Use CNC machining equipment to accurately process the blank; Step 4: Shot blasting the finely machined blade (3) to remove surface defects and burrs; Step 5: Assemble the processed blade (3) structure and conduct strict inspection.

6. A method for preparing a steam turbine blade structure according to claim 5, characterized in that: In step three, the blade (3) is finely machined using a five-axis CNC surface milling machine.

7. The method for preparing a steam turbine blade structure according to claim 5, characterized in that: In step four, shot blasting is performed using appropriate shot blasting media and process parameters.

8. The method for preparing a steam turbine blade structure according to claim 5, characterized in that: In step five, the inspection of the blade (3) includes: size inspection, shape and position tolerance inspection, material property inspection and surface quality inspection.

9. The method for preparing a steam turbine blade structure according to claim 5, characterized in that: The detection in step 5 also includes: A rotation speed sensor for detecting the rotation speed per second of the turbine blade (3); A gas flow rate sensor for detecting the intake speed of the turbine gas through the blades (3); A controller and an alarm, wherein the controller is electrically connected to the rotation speed sensor, the gas flow rate sensor and the alarm, and the controller controls the alarm to work based on the rotation speed sensor and the gas flow rate sensor.

10. A method for preparing a steam turbine blade structure according to claim 9, characterized in that: The following steps are involved: Step 1: According to formula (1), calculate the natural frequency of the turbine blade (3) in the non-rotating state: （1）； in is the natural frequency coefficient of blade (3), is the material property coefficient of the blade (3), is the geometrical shape factor of the blade (3), is the support mode coefficient of blade (3), is the elastic modulus of the blade (3) material, is the minimum centroidal principal moment of inertia of the blade (3) section, is the mass of blade (3), is the height of the blade (3), The value is 3.14; Step 2: Calculate the dynamic frequency coefficient of the turbine blade (3) based on formula (2) and the speed sensor detection value （2）； in is the natural frequency of the blade (3) in the working state, is the natural frequency of blade (3) in the non-rotating state, is the average diameter of the blade (3), is the speed sensor detection value, is the angle between the turbine blades (3) and the blades (3), is a sine; Step 3: Calculate the actual gap airflow excitation force of the blade (3) during the operation of the turbine according to the following formula (3) and the gas velocity sensor detection value: The controller compares the actual gap airflow excitation force of the blade (3) during the operation of the turbine When the actual gap airflow excitation force exceeds the preset gap airflow excitation force range, the controller controls the alarm to sound an alarm: （3）； in is the gas flow rate sensor detection value, is the linear velocity of the blade (3), is the cosine, is the airflow outlet angle of the blade (3) in a stationary state, is the blade inlet angle, is the gas velocity coefficient, is the blade outlet angle, is the average density of the airflow through the turbine blade (3), is the tip radius of the blade (3), is the root radius of the blade (3), is the average gap between the tip of blade (3) and the tip of blade (3), is the eccentricity.

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