A 141mm unshrouded last stage blade for high speed steam turbine

Abstract

A 141mm no band last stage moving vane for high speed steam turbine relates to a last stage moving vane.The utility model discloses in order to solve the problem that the last stage moving vane of existing low power high speed steam turbine is easy to cause unit resonance and is easy to be damaged by water erosion.The utility model discloses the stress is reduced and the inherent frequency can be raised and the water drop can be discharged from the blade top by adopting no band structure, and the risk of blade water erosion is avoided;At the same time, the reasonable blade shape, size and blade stiffness make the blade can deal with the problem of large stress and resonance.Secondly, the whole blade is loose assembly in assembly, and the pull bar between the adjacent two blades and the pull bar are not in contact;When running, the pull bar part of the adjacent two blades is partially contacted by torsion recovery, so that the moving vane forms a whole circle connection, improves the stiffness of the whole stage blade and thus raises the frequency, and the assembly is also relatively simple.The utility model belongs to the technical field of steam turbine blade.

Description

Technical Field

[0001] This utility model relates to a final stage moving blade, specifically a 141mm unshrouded final stage moving blade for high-speed steam turbines, belonging to the field of steam turbine blade technology. Background Technology

[0002] Unlike normal units, the last-stage blades of a 3MW low-power, high-speed steam turbine unit require shorter blade profiles. Due to the high speed and centrifugal force of the blades, the relatively short last-stage moving blades will also experience greater stress.

[0003] Meanwhile, the frequency assessment of the blades is also very critical. Due to the high rotational speed, the natural frequency line of the blades is close to the velocity line, which can easily cause unit resonance. Secondly, due to the high humidity of the steam in the last stage, water erosion also has a significant impact on the blades.

[0004] In summary, how to propose a novel final-stage moving blade to address the aforementioned technical problems has become a pressing issue for those skilled in the art. Utility Model Content

[0005] This invention addresses the shortcomings of the prior art by providing a 141mm unshrouded final stage moving blade for high-speed steam turbines.

[0006] The technical solution of this utility model is: a 141mm unshrouded last-stage moving blade for a high-speed steam turbine, comprising a working part of the blade, a blade root, and two tie rods.

[0007] The profile of the working part of the blade is a variable cross-section twisted blade, and the cross-sectional area of ​​the working part of the blade gradually decreases from the root to the top.

[0008] The blade root is integrated at the root of the working part of the blade, and the tie rod is integrated on both sides of the working part of the blade, with the tie rod arranged at 83.3% of the height of the working part of the blade.

[0009] The height L of the working part of the blade is 141mm, the axial width V of the root of the working part of the blade is 46.79mm, and the root diameter of the working part of the blade is 190mm.

[0010] The axial width W of the leaf root is 55mm.

[0011] The axial width of the working part of the blade is V, which varies from 46.79 mm to 24.62 mm from the root to the tip. The chord length of the working part of the blade is b, which varies from 49.82 mm to 43.46 mm from the root to the tip. The installation angle of the working part of the blade is β. y ,β yThe variation range from root to tip is 69.89° to 32.94°. The maximum thickness of the blade working section profile is T, which varies from root to tip from 9.7 mm to 4.6 mm. The inlet angle of the blade working section is α, which varies from root to tip from 58.00° to -31.00°. The outlet angle of the blade working section is θ, which varies from root to tip from 62.00° to 69.00°.

[0012] Furthermore, when the height L of the working part of the blade is 0 mm, 6.14 mm, 29.66 mm, 59.33 mm, 88.99 mm, 118.66 mm, and 141 mm,

[0013] The axial widths V of the corresponding working parts of the blades are, in order: 46.79mm, 44.37mm, 41.25mm, 35.82mm, 30.35mm, 24.95mm, and 24.62mm.

[0014] The corresponding chord lengths b of the working parts of the blades are 49.82mm, 48.92mm, 47.73mm, 46.32mm, 45.25mm, 44.97mm, and 43.46mm, respectively.

[0015] The corresponding installation angle β of the working part of the blade y The angles are 69.89°, 63.42°, 58.44°, 49.61°, 41.51°, 33.05°, and 32.94°, respectively.

[0016] The maximum thickness T of the corresponding blade working section profiles are as follows: 9.7mm, 9.4mm, 8.1mm, 6.9mm, 6.4mm, 5.4mm, and 4.6mm.

[0017] The corresponding inlet angles α of the working parts of the blades are: 58.00°, 52.00°, 53.00°, 42.00°, 10.79°, -9.48°, and -31.00°, respectively.

[0018] The corresponding exit angles θ of the working parts of the blades are 62.00°, 66.94°, 72.00°, 73.00°, 74.00°, 77.00°, and 69.00°, respectively.

[0019] Furthermore, the total height K of the leaf root is 27.68 mm.

[0020] Furthermore, the leaf roots are fir-type leaf roots.

[0021] Furthermore, the end face of the tie is elliptical, with a major axis of 12mm and a minor axis of 8mm.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The blade design of this utility model adopts a reasonable beltless structure, which can reduce stress, increase natural frequency, and discharge water droplets from the blade tip, avoiding the risk of water erosion of the blade; at the same time, the reasonable blade shape, size and blade stiffness enable the blade to cope with the problems of high stress and resonance.

[0024] 2. This utility model adopts a single-connection tie design. During assembly, the entire blade is loosely assembled, so that the tie rods between adjacent blades do not contact each other. During operation, the tie rods between adjacent blades are brought into contact through torsion recovery, so that the moving blades form a full circle connection, which improves the stiffness of the entire stage blade and thus increases the frequency. At the same time, the assembly is also relatively simple.

[0025] 3. This utility model adopts a full three-dimensional unsteady aerodynamic calculation method, which can maintain high aerodynamic efficiency and excellent performance under varying operating conditions within a wider back pressure range.

[0026] 4. This utility model adopts comprehensive optimization of fluid dynamics and structural strength, which solves the problem of integrated aerodynamic / structural design optimization, and makes the flow efficiency and strength vibration characteristics of the blades optimal. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0028] Figure 2 This is a schematic diagram of the cross-sectional cross-sections of the working part 1 of the blade of this utility model.

[0029] Figure 3 This is a top view of the tie rod 3 of this utility model;

[0030] Figure 4 This is a typical cross-sectional schematic diagram of the working part 1 of the blade of this utility model;

[0031] Figure 5 yes Figure 4 A magnified view of a section at point I;

[0032] Figure 6 yes Figure 4 A magnified view of section II in the middle.

[0033] In the diagram: 1. Working part of the leaf; 2. Leaf root; 3. Supporting tendon. Detailed Implementation

[0034] To make the utility model's objectives, features, and advantages more apparent and understandable, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0035] Specific implementation method one: Combining Figures 1 to 6 This embodiment describes a 141mm unshrouded last-stage moving blade for a high-speed steam turbine, comprising a working part 1, a blade root 2, and two tie rods 3.

[0036] The profile of the working part 1 of the blade is a variable cross-section twisted blade, and the cross-sectional area of ​​the working part 1 of the blade gradually decreases from the root to the top.

[0037] The leaf root 2 is integrally set at the root of the working part 1 of the blade, and the tie rod 3 is integrally set on both sides of the working part 1 of the blade, and the tie rod 3 is arranged at 83.3% of the height of the working part 1 of the blade.

[0038] The height L of the working part 1 of the blade is 141mm, the axial width V of the root of the working part 1 of the blade is 46.79mm, and the root diameter of the working part 1 of the blade is 190mm.

[0039] The axial width W of the leaf root 2 is 55mm.

[0040] The axial width of the working part 1 of the blade is V, which varies from 46.79 mm to 24.62 mm from the root to the tip. The chord length of the working part 1 of the blade is b, which varies from 49.82 mm to 43.46 mm from the root to the tip. The installation angle of the working part 1 of the blade is β. y ,β y The variation range from root to top is 69.89° to 32.94°. The maximum thickness of the profile of the working part 1 of the blade is T, which varies from root to top from 9.7mm to 4.6mm. The inlet angle of the working part 1 of the blade is α, which varies from root to top from 58.00° to -31.00°. The outlet angle of the working part 1 of the blade is θ, which varies from root to top from 62.00° to 69.00°.

[0041] In this embodiment, the entire blade is loosely assembled, meaning that the tie rods between adjacent blades do not contact each other. During operation, the tie rods between adjacent blades are brought into contact through torsion recovery, so that the moving blades form a complete loop connection, which improves the stiffness of the entire blade stage and thus increases the frequency. At the same time, the assembly is also relatively simple.

[0042] Specific Implementation Method Two: Combining Figures 1 to 6This embodiment describes the following scenarios: When the height L of the working part 1 of the blade is 0 mm, 6.14 mm, 29.66 mm, 59.33 mm, 88.99 mm, 118.66 mm, and 141 mm,

[0043] The axial widths V of the corresponding working parts 1 of the blades are, in order: 46.79 mm, 44.37 mm, 41.25 mm, 35.82 mm, 30.35 mm, 24.95 mm, and 24.62 mm.

[0044] The chord lengths b of the corresponding working parts 1 of the blades are 49.82mm, 48.92mm, 47.73mm, 46.32mm, 45.25mm, 44.97mm, and 43.46mm, respectively.

[0045] The corresponding installation angle β of the working part 1 of the blade y The angles are 69.89°, 63.42°, 58.44°, 49.61°, 41.51°, 33.05°, and 32.94°, respectively.

[0046] The maximum thickness T of the profile of the corresponding working part 1 of the blade is as follows: 9.7mm, 9.4mm, 8.1mm, 6.9mm, 6.4mm, 5.4mm, and 4.6mm.

[0047] The inlet angles α of the corresponding working parts 1 of the blades are, respectively: 58.00°, 52.00°, 53.00°, 42.00°, 10.79°, -9.48°, and -31.00°.

[0048] The exit angles θ of the corresponding working parts 1 of the blades are 62.00°, 66.94°, 72.00°, 73.00°, 74.00°, 77.00°, and 69.00°, respectively.

[0049] By adopting the above structural parameters, the blade's external dimensions can meet the design requirements, while also making the blade easy to assemble.

[0050] The other components and connections are the same as in Specific Implementation Method 1.

[0051] Specific implementation method three: Combining Figures 1 to 6 This embodiment describes leaf root 2 as a fir-type leaf root.

[0052] Furthermore, the total height K of the blade root 2 is 27.68 mm. This structure allows the blade to be securely installed into the rim, ensuring stable, safe, and reliable assembly. Other components and connections are the same as in specific embodiments one or two.

[0053] Specific implementation method four: Combination Figures 1 to 6 In this embodiment, the end face of the tie rod 3 is elliptical, with a major axis of 12mm and a minor axis of 8mm. Other components and connections are the same as in specific embodiments one, two, or three.

[0054] Specific Implementation Method Five: Combining Figures 1 to 6 This embodiment describes the specific parameters of each cross-section as shown in the table below:

[0055]

[0056] The other components and connections are the same as those in specific implementation methods one, two, three, or four.

[0057] The present invention has been disclosed above with reference to preferred embodiments, but it is not intended to limit the present invention. Any simple modifications, equivalent changes and alterations made by those skilled in the art to the above embodiments without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A 141mm unshrouded last-stage moving blade for a high-speed steam turbine, characterized in that: It includes the working part of the leaf (1), the leaf root (2) and two bracing (3); The profile of the working part (1) of the blade is a variable cross section twisted blade, and the cross-sectional area of ​​the working part (1) of the blade gradually decreases from the root to the top. The leaf root (2) is integrally set at the root of the working part (1) of the leaf, and the bracing (3) is integrally set on both sides of the working part (1) of the leaf, and the bracing (3) is arranged at 83.3% of the height of the working part (1) of the leaf. The height L of the working part (1) of the blade is 141 mm, the axial width V of the root of the working part (1) of the blade is 46.79 mm, and the root diameter of the working part (1) of the blade is 190 mm. The axial width W of the leaf root (2) is 55 mm; The axial width of the working part (1) of the blade is V, which varies from 46.79 mm to 24.62 mm from the root to the tip. The chord length of the working part (1) of the blade is b, which varies from 49.82 mm to 43.46 mm from the root to the tip. The installation angle of the working part (1) of the blade is β. y ,β y The variation range from the root to the top is 69.89° to 32.94°. The maximum thickness of the profile of the working part of the blade (1) is T, and the variation range of T from the root to the top is 9.7mm to 4.6mm. The inlet angle of the working part of the blade (1) is α, and the variation range of α from the root to the top is 58.00° to -31.00°. The outlet angle of the working part of the blade (1) is θ, and the variation range of θ from the root to the top is 62.00° to 69.00°.

2. The 141mm unshrouded last-stage moving blade for a high-speed steam turbine according to claim 1, characterized in that: When the height L of the working part (1) of the blade is 0 mm, 6.14 mm, 29.66 mm, 59.33 mm, 88.99 mm, 118.66 mm, and 141 mm respectively, The axial widths V of the corresponding working parts (1) of the blades are as follows: 46.79 mm, 44.37 mm, 41.25 mm, 35.82 mm, 30.35 mm, 24.95 mm, and 24.62 mm, respectively. The chord lengths b of the corresponding working parts (1) of the blades are 49.82 mm, 48.92 mm, 47.73 mm, 46.32 mm, 45.25 mm, 44.97 mm, and 43.46 mm, respectively. The mounting angle β of the corresponding blade working part (1) y The angles are 69.89°, 63.42°, 58.44°, 49.61°, 41.51°, 33.05°, and 32.94°, respectively. The maximum thickness T of the profile of the corresponding working part (1) of the blade is as follows: 9.7mm, 9.4mm, 8.1mm, 6.9mm, 6.4mm, 5.4mm, and 4.6mm, respectively. The inlet angles α of the corresponding working parts (1) of the blades are respectively: 58.00°, 52.00°, 53.00°, 42.00°, 10.79°, -9.48°, and -31.00°. The exit angles θ of the corresponding working parts (1) of the blades are 62.00°, 66.94°, 72.00°, 73.00°, 74.00°, 77.00°, and 69.00°, respectively.

3. A 141mm unshrouded last-stage moving blade for a high-speed steam turbine according to claim 2, characterized in that: The total height K of the leaf root (2) is 27.68 mm.

4. A 141mm unshrouded last-stage moving blade for a high-speed steam turbine according to claim 3, characterized in that: The leaf root (2) is a fir-type leaf root.

5. A 141mm unshrouded last-stage moving blade for a high-speed steam turbine according to claim 4, characterized in that: The end face of the tie rod (3) is elliptical, with a major axis of 12mm and a minor axis of 8mm.

Images