A method for effectively improving the wear resistance of turbine runner blades and turbine runner blades

Abstract

This invention discloses a method for effectively improving the wear resistance of turbine runner blades and a turbine runner blade, characterized by parameterizing the distribution law of the rotation angle of each profile at the inlet of the runner blade, using a power function angle change f(s) = As. n The variation law of the rotation angle of various profiles at the inlet of the turbine runner blades is designed. The beneficial effects of this invention are: (1) This method enriches the basic theory of turbine design and expands its application scope. After a large amount of theoretical analysis and numerical simulation verification, an optimization method to effectively improve the wear resistance of turbine runner blades is proposed. (2) This method can select reasonable exponent n and parameter A according to different runner conditions to achieve the purpose of reducing blade wear, and can provide services for the design of turbine runners under sandy water flow conditions.

Description

Technical Field

[0001] This invention belongs to the field of fluid machinery and engineering equipment technology, specifically relating to a method for effectively improving the wear resistance of turbine runner blades and turbine runner blades. Background Technology

[0002] Hydropower turbines are among the most important hydraulic equipment. During the operation of high-head, ultra-large-capacity hydropower turbines, the complex internal flow and high water velocity cause serious damage to the surface of the flow components due to the impact of sediment particles, which exacerbates the hydraulic losses of the turbine and poses a challenge to its structural strength, thus creating difficulties for hydropower development on sediment-laden rivers. Summary of the Invention

[0003] This invention mainly addresses the limitations of existing turbine runner design methods by proposing a method and a turbine runner blade that effectively improves the wear resistance of turbine runner blades.

[0004] To achieve the above objectives, the present invention proposes the following technical solution:

[0005] This invention provides a method for effectively improving the wear resistance of turbine runner blades, characterized in that the rotation angles of each profile at the runner blade inlet are parameterized, and the rotation angles of each profile at the runner blade inlet are based on power function variations.

[0006] Furthermore, the power function is:

[0007]

[0008] In the formula: This represents the relative offset of the blade inlet profile. The relative position of the blade profile. For the exponent term, This represents the relative offset of the inlet of the crown line on the blade. .

[0009] Furthermore, the relative offset of the crown line inlet on the blade satisfies 0.1≤A≤0.3.

[0010] The present invention also provides a turbine runner blade that effectively improves wear resistance, characterized in that the rotation angle of each profile at the blade inlet conforms to a power function variation law.

[0011] Furthermore, the power function is:

[0012]

[0013] In the formula: This represents the relative offset of the blade inlet profile. The relative position of the blade profile. For the exponent term, This represents the relative offset of the inlet of the crown line on the blade. .

[0014] Furthermore, the relative offset of the crown line inlet on the blade satisfies 0.1≤A≤0.3.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This method enriches the fundamental theory of turbine design and expands its application scope. Extensive theoretical analysis and numerical simulation verification have revealed that this invention alters the distribution of vortices within the runner, effectively eliminating the lateral flow from the upper crown to the lower ring at the runner inlet and reducing the carrying effect of the impeller vortex near the lower ring on sediment particles. This method allows for the selection of appropriate indices n and A to configure runner blades based on different runner conditions, thereby reducing blade wear and improving the runner's wear resistance. It can provide services for turbine runner design under sediment-laden water flow conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the optimized structure of the rotor inlet of the present invention.

[0018] Figure 2 This is a schematic diagram comparing the wear of the optimized impeller blades with that of the original blades. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0020] This embodiment provides a method for effectively improving the wear resistance of turbine runner blades. The rotation angles of various profiles at the runner blade inlet are based on a power function variation. The distribution law of the rotation angles of various profiles at the runner blade inlet is parameterized, and the power function is:

[0021]

[0022] In the formula: This represents the relative offset of the blade inlet profile. The relative position of the blade profile. For the exponent term, This represents the relative offset of the inlet of the crown line on the blade. .

[0023] The relative offset of the inlet of the crown line on the blade satisfies 0.1≤A≤0.3.

[0024] This embodiment also provides a turbine runner blade that effectively improves wear resistance, wherein the rotation angle of each profile at the blade inlet conforms to the power function variation law.

[0025] The power function is:

[0026]

[0027] In the formula: This represents the relative offset of the blade inlet profile. The relative position of the blade profile. For the exponent term, This represents the relative offset of the inlet of the crown line on the blade. .

[0028] In conventional turbine design, f(s) = 0, meaning the inlet is vertical and the rotation angle at the inlet of each blade profile is 0. However, after in-depth research into the design theory of turbine runners, it was discovered that altering the distribution pattern of the rotation angle at the inlet of each blade profile can effectively increase the wear resistance of the runner blades.

[0029] In the aforementioned method for effectively improving the wear resistance of impeller blades and their inlet design, when the exponent n < 1, impeller blades with this type of inlet profile distribution pattern, when A approaches 0.1, show a reduced blade wear rate and improved wear resistance under the same flow rate. For impeller designs operating under sediment-laden water flow conditions, the aforementioned blade profile inlet rotation angle distribution pattern can be adopted, where A is used at a smaller value within the range of 0.1 ≤ A ≤ 0.3 to reduce the blade wear rate.

[0030] In the above-mentioned method for effectively improving the wear resistance of impeller blades, the... When using impeller blades with this type of imported profile distribution pattern, under the same flow rate, when 0.1≤A≤0.3, the wear rate of the blades is significantly reduced and the wear resistance is improved. It can be effectively applied to the design of water turbines and impellers under sandy water flow conditions.

[0031] use The inlet rotation angle distribution patterns for blade profiles are as follows: Blade 1 uses an n=0.5 blade profile; Blade 2 uses an n=1 blade profile; Blade 3 uses an n=2 blade profile; Blade 4 uses an n=2 blade profile. The inlet structure diagram is shown below. Figure 1 In this application, A is taken as 0.3.

[0032] During the verification of the invention method, the accuracy of the numerical calculations was verified based on on-site turbine sediment wear data. Subsequently, design parameters such as inlet and outlet diameters, head, and flow rate of the runner from the Nepal JHC power station model were extracted for independent runner design. The aforementioned invention method was then used for optimization. After calculation, the optimized results were compared with the original runner. Figure 2 This is a comparison chart of the wear rates of the pressure surfaces of the two surfaces.

[0033] Example 1:

[0034] The distribution law of the inlet rotation angle of the prototype turbine blade profile is as follows The calculated average wear rate is 1.58. 10 -7 kg / s / m 2 .

[0035] Example 2:

[0036] The optimized rotor blade profile inlet rotation angle distribution is adopted in the form of n=0.5. The average wear rate of the rotor blades is calculated using numerical simulation. The calculation results show that the average wear rate of the rotor blades is 1.53%. The average wear rate of the blades was 10-7 kg / s / m2, which is slightly lower than the result calculated in Example 1.

[0037] Example 3:

[0038] The optimized rotor blade profile inlet rotation angle distribution is adopted in the form of n=1. The average wear rate of the rotor blades is calculated using numerical simulation. The calculation results show that the average wear rate of the rotor blades is 1.12. 10 -7 kg / s / m 2 Compared with the results calculated in Example 1, the average wear rate of the blades was reduced by approximately 29%.

[0039] Example 4:

[0040] The optimized rotor blade profile inlet rotation angle distribution is adopted in the form of n=2. The average wear rate of the rotor blades is calculated using numerical simulation. The calculation results show that the average wear rate of the rotor blades is 1.18%. 10 -7 kg / s / m 2 Compared with the results calculated in Example 1, the average wear rate of the blades was reduced by approximately 25%.

[0041] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for effectively improving the wear resistance of the runner blade of a hydraulic turbine, characterized in that, The rotation angles of the various profiles at the inlet of the runner blade are parameterized, and the rotation angles of the various profiles at the inlet of the runner blade vary based on a power function; The power function is: wherein: is the relative offset of the blade inlet profile, is the relative position of the blade profile, is the exponential term, is the relative offset of the blade upper crown profile inlet, The relative offset of the upper crown profile at the inlet of the blade satisfies 0.1≤A≤0.

3.

2. A water turbine runner blade effective to improve wear resistance, characterized by, The rotation angles of the various profiles at the inlet of the runner blade vary according to a power function, and the power function is: wherein: is the relative offset of the blade entry profile, is the relative position of the blade profile, is the exponential term, is the relative offset of the blade upper crown entry profile, The relative offset of the upper crown profile at the inlet of the blade satisfies 0.1≤A≤0.3.

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