A packing for a long blade of a steam turbine

Abstract

The application provides a packing for a long blade of a steam turbine, comprising: a long strip structure, C-shaped grooves are arranged on both sides of the long strip structure along the length direction of the long strip structure, two strip structures are formed on the upper and lower sides of the C-shaped grooves respectively; one end of the long strip structure is a wedge-shaped structure, and a tail groove is arranged on the end face of the other end of the long strip structure; a top boss is arranged on each elastic structure; and a stress release groove is arranged on the long strip structure and located between the two elastic structures. The application provides a mode of arranging C-shaped grooves 11 on both sides of the long strip structure 1, so that the requirement for the width direction of the clamping groove is reduced.

Description

Technical Field

[0001] This invention relates to the technical field of a packing material, and more particularly to the technical field of a packing material for long turbine blades. Background Technology

[0002] A steam turbine is a rotating machine that converts steam energy into mechanical work. It typically operates under high temperature, high pressure, and high speed conditions and is the prime mover used in large-scale thermal power generation in power plants. In addition, it has wide applications in chemical, aerospace, and shipping industries. Damage to a steam turbine not only causes inconvenience to people's lives but also results in significant economic losses; therefore, the normal operation of steam turbines is crucial.

[0003] Blades are one of the core components of a steam turbine. In the steam turbine's flow path, the steam flow force acts on the blades, converting steam energy into mechanical energy for the entire rotor system. The normal and orderly operation of the blades is a prerequisite for the normal operation of the steam turbine; therefore, ensuring the normal and safe operation of the blades is crucial.

[0004] During blade assembly, to ensure a tight fit between the blade root 5 and the rotor groove 6 in the non-operating state, a filler fitting technique is typically used. This involves using a filler fitting to press against the bottom of the blade root 5, ensuring a tight fit between the blade root 5 and the rotor groove 6, thus facilitating precise blade installation. Generally, filler fittings are mainly used for fir-shaped blade roots. A tightening groove 4 is cut between the bottom of the blade root 5 and the bottom of the rotor groove 6. The dimensions of the tightening groove 4 are determined by calculating the tolerances of the fit dimensions to ensure accurate installation of the filler fitting. During installation, after the blade is positioned in the rotor groove 6, the tail of the filler fitting is tapped, and it is slowly guided into the tightening groove 4 from the head. Since the height of the filler fitting is greater than the height of the tightening groove 4, this interference fit causes the filler fitting to press against the bottom of the blade root 5, providing a tightening force and ensuring the assembly of the blade root 5 and the rotor groove 6.

[0005] The existing packing element provides clamping force to the blade by interfering with the bottom of the blade root 5 through a small area of ​​the boss. However, due to the limited space of the clamping groove 4 for installing the packing element, it is necessary to accurately measure the height dimension of the clamping groove 4 and accurately grind the height dimension of the packing element to ensure that the interference fit accurately meets the installation requirements. Generally, the interference fit is required to be less than 1mm. It cannot be too large or too small. If it is too large, the packing element is prone to failure and cannot bear the load after assembly. If it is too small, the packing element cannot provide the corresponding clamping force after assembly. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a packing component for long turbine blades, which solves the problems of easy failure of the packing component during assembly and insufficient force to tighten the blade root in the prior art.

[0007] To achieve the above and other related objectives, the present invention provides a packing material for long turbine blades, comprising:

[0008] The long strip structure has a C-shaped groove on each of its two sides along its length, and two strip structures are formed on the upper and lower sides of the C-shaped groove; one end of the long strip structure is a wedge-shaped structure, and the other end face of the long strip structure is provided with the tail groove.

[0009] A top protrusion is provided on each of the elastic structures;

[0010] A stress relief groove is provided on the elongated structure and is located between the two elastic structures.

[0011] Preferably, the width of the strip structure is one-quarter of the width of the filling element.

[0012] Preferably, the included angle of the profile of the C-shaped groove is 10° to 20°.

[0013] Preferably, the width of the top boss is one-eighth to one-sixth of the width of the filling member.

[0014] Preferably, the thickness of the top boss is 1mm to 5mm.

[0015] Preferably, the tail groove is a circular groove, and the radius of the circular groove is one-third of the height of the filling member.

[0016] Preferably, the circular groove is located between the two C-shaped grooves and is located below the stress relief groove.

[0017] Preferably, the distance between the bottom of the arc groove and the end of the top boss in the longitudinal direction is 1mm to 2mm.

[0018] Preferably, the included angle between the two sides of the wedge-shaped structure is 10° to 16°.

[0019] As described above, the packing material for long turbine blades according to the present invention has the following beneficial effects:

[0020] This invention provides a method of setting C-shaped grooves on both sides of the elongated structure 1, reducing the requirements for the width of the clamping groove. In addition, this invention incorporates stress-relieving grooves, which enhance the deformation capacity of the packing member, thereby providing a larger and safer clamping force. Furthermore, the packing member of this invention significantly increases the contact area between the top boss of the packing member and the bottom of the blade root, enabling the packing member to provide a greater clamping force and meet the blade clamping force requirements with less deformation, thus greatly benefiting the safe operation of the packing member. Attached Figure Description

[0021] Figure 1 The diagram shows the wheel groove, blade root, and clamping groove of a conventional steam turbine.

[0022] Figure 2 The image shown is a perspective view of a packing material for long turbine blades according to the present invention.

[0023] Figure 3 The image shown is a top view of a packing material for a long turbine blade according to the present invention.

[0024] Figure 4 The image shown is a right view of a packing material for a long turbine blade according to the present invention.

[0025] Figure 5 The diagram shows a schematic representation of the present invention for fixing long turbine blades to rotor grooves and filler components before installation.

[0026] Figure 6 The diagram shown is a schematic representation of the installation of a steam turbine long blade to the rotor groove and filler material according to the present invention.

[0027] Component designation explanation

[0028] 1. Long strip structure

[0029] 11 C-groove

[0030] 12 strip structures

[0031] 13 Tail Groove

[0032] 2. Top boss

[0033] 3. Stress relief groove

[0034] 4. Tightening groove

[0035] 5 leaf roots

[0036] 6 wheel grooves Detailed Implementation

[0037] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0038] Please see Figures 1 to 5It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0039] like Figure 1 As shown, the present invention provides a packing material for long turbine blades, comprising:

[0040] The long strip structure 1 has a C-shaped groove 11 on each of its two sides along its length, and two strip structures 12 are formed on the upper and lower sides of the C-shaped groove 11 respectively; one end of the long strip structure 12 is a wedge-shaped structure, and the other end face of the long strip structure 12 is provided with a tail groove 13.

[0041] Top protrusion 2, one top protrusion 2 is provided on each of the upper strip structures 12;

[0042] The stress relief groove 3 is provided on the elongated structure 1 and is located between the two top bosses 2.

[0043] This invention incorporates C-shaped grooves 11 on both sides of the elongated structure 1, creating elastic structures on both sides and allowing the upper strip structure 12 to deform to a certain extent. Furthermore, to increase contact between the blade root 5 and the inner wall of the rotor groove 6, a top boss 2 is provided on the strip structure 12. Compared to existing packing components, the top boss 12 has greater contact with the inner wall of the groove, and the length of the top boss 2 allows for greater control over the clamping force range. Additionally, the stress relief groove 3 in this invention has a symmetrical and uniform strain distribution with a large and wide range of values, thus bearing more of the load applied by the elastic structures on both sides, thereby providing a wider range of clamping force for the packing component.

[0044] To ensure that the strip structure 12 has a certain deformation capacity without collapsing directly under stress, the included angle θ1 of the C-shaped groove section is now set to 10° to 20°. This is because when θ1 is less than 10°, the strip structure 12 may lack sufficient elasticity; when θ1 is greater than 20°, the strip structure 12 may lack support and fail to provide sufficient clamping force at the blade root 5.

[0045] Similarly, if the width of the strip structure 12 is set too short, it will also make it difficult for the strip structure 12 to deform; therefore, the width of the strip structure 12 needs to be at least one-quarter of the width of the filling material to ensure that the strip structure 12 has a certain degree of elasticity.

[0046] Because if the width of the top boss 2 is too small, it cannot effectively support the bottom of the blade root 5; and if the width of the top boss 2 is too large, it may prevent the top boss 2 from deforming properly and from reaching the tightening groove 4. Therefore, the width of the top boss 2 is now set to one-eighth to one-sixth of the width of the filling component.

[0047] Similarly, to avoid the top boss 2 not being able to penetrate the tightening groove 4 and the top boss 2 being too thin to achieve an interference fit with the tightening groove 4, preferably, the thickness of the top boss 2 is set to 1mm to 5mm.

[0048] In order to fix the filling component to the opening end of the top clamping groove 4 after the filling component is set, a tail groove 13 is opened at one end of the back wedge structure of the filling component. The tail groove is a circular groove.

[0049] To avoid the circular groove being too deep and affecting the elasticity of the filler, the radius of the circular groove is now set to one-third of the height of the filler, and the axial depth of the circular groove ranges from 2mm to 5mm. Specifically, the circular groove is located between the two C-shaped grooves and below the stress relief groove 3.

[0050] In addition, to facilitate the installation and removal of fasteners from the circular groove, the bottom of the circular groove is now rounded.

[0051] Because the top boss 2 bears the pressure generated by contact with the blade root 5, a certain downward pressure will be generated at the top boss 2. The opening of the circular groove will affect the elasticity of the corresponding position of the filling component. In order to avoid the influence of the circular groove on the filling component, the distance between the bottom of the circular groove and the end of the top boss 2 in the length direction is now 1 to 2 mm.

[0052] In order to make it easier for the wedge structure to be inserted into the tightening groove 4, the included angle between the two sides of the wedge structure is now set to 10-16°.

[0053] In addition to the above embodiments, the present invention also includes the following installation method:

[0054] The packing material is installed between the bottom of the blade root 5 and the wheel groove 6. A groove is cut in the wheel groove 6 to insert the packing material, such as... Figure 5During installation, the blades need to be inserted into the wheel groove 6 first. After the blades are in place, a process shim is inserted into the non-contact surface between the blade root 5 and the wheel groove 6. This process shim can temporarily tighten the blade, making the blade root 5 and the wheel groove 6 fit tightly. After the filler is inserted into the wheel groove 6, the process shim is removed. Before installation, the height h from the bottom of the blade root 5 to the bottom of the groove is measured one by one. According to the interference fit e required by the design, the height of the filler boss or the bottom plane is ground one by one so that the filler height x satisfies x = h + e. Since it is an interference fit installation, the wedge structure can first guide the filler smoothly into the tightening groove 4, and then the tail of the filler is struck by external force until it is completely inserted into the tightening groove 4. Finally, the support bar is installed to prevent the filler from sliding out of the tightening groove 4.

[0055] In summary, this invention reduces the requirements for the width of the clamping groove 4 by providing C-shaped grooves 11 on both sides of the elongated structure 1. Furthermore, the stress-relieving groove 3 enhances the deformation capacity of the packing member, thereby providing a larger and safer clamping force. Additionally, the packing member of this invention significantly increases the contact area between the top boss 2 of the packing member and the bottom of the blade root 5, enabling the packing member to provide a greater clamping force and meet the blade clamping force requirements with less deformation, which is highly beneficial for the safe operation of the packing member.

[0056] Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0057] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A packing material for long turbine blades, characterized in that, include: The long strip structure has a C-shaped groove on each of its two sides along its length, and two strip structures are formed on the upper and lower sides of the C-shaped groove; one end of the long strip structure is a wedge-shaped structure, and the other end of the long strip structure is provided with a tail groove. A top protrusion is provided on each of the strip structures; A stress relief groove is provided on the elongated strip structure and is located between the two strip structures.

2. The packing material for long turbine blades according to claim 1, characterized in that: The width of the strip structure is one-quarter of the width of the filling element.

3. A packing material for long turbine blades according to claim 1, characterized in that: The included angle of the profile of the C-shaped groove is 10°~20°.

4. A packing material for long turbine blades according to claim 1, characterized in that: The width of the top boss is one-eighth to one-sixth of the width of the filling component.

5. A packing material for long turbine blades according to claim 1, characterized in that: The thickness of the top boss is 1mm to 5mm.

6. A packing material for long turbine blades according to claim 1, characterized in that: The tail groove is a circular groove, and the radius of the circular groove is one-third of the height of the filling member.

7. A packing material for long turbine blades according to claim 6, characterized in that: The circular groove is located between the two C-shaped grooves and is located below the stress relief groove.

8. A packing material for long turbine blades according to claim 6, characterized in that: The distance between the bottom of the circular groove and the end of the top boss in the longitudinal direction is 1mm to 2mm.

9. A packing material for long turbine blades according to claim 1, characterized in that: The included angle between the two profiles of the wedge structure is 10° to 16°.

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