Movable steam seal ring for nuclear power low-voltage module

Abstract

A movable steam seal ring for a nuclear power low-pressure module belongs to the technical field of steam turbines and comprises an upper half ring, a lower half ring and a connecting component. The upper half ring and the lower half ring are the same in structure, and the upper half ring and the lower half ring are connected together through the connecting assembly to form a circular ring. The connecting assembly comprises connecting pieces, sleeves and fasteners, mounting holes are formed in the two ends of the upper half ring and the two ends of the lower half ring respectively, one sleeve is mounted on one side face of each mounting hole, when the upper half ring and the lower half ring are in butt joint, the connecting pieces are arranged on the other side faces of the two mounting holes where the butt joint ends are located, and the connecting holes are formed in the two ends of each connecting piece. The fastening piece is arranged in the connecting hole in a penetrating manner and is screwed in the inner threaded hole of the sleeve; and the axes of the mounting hole, the connecting hole and the sleeve are parallel to the axis of the circular ring. The steam seal overcomes the defect that a traditional steam seal cannot meet the requirements for axial displacement and radial displacement at the same time.

Description

Technical Field

[0001] This utility model relates to a steam seal ring, specifically a movable steam seal ring for a nuclear power low-pressure module, belonging to the field of steam turbine technology. Background Technology

[0002] As the nuclear power market continues to demand higher power output from its units, the design of new low-pressure modules for half-speed turbines increasingly requires longer last-stage blades and more diaphragms to be incorporated into the steam chamber (or diaphragm sleeve). Traditional steam seal assemblies, due to installation limitations, struggle to simultaneously meet the following requirements:

[0003] 1. Limited space prevents the installation of multiple levels of steam seals with spring plates;

[0004] 2. The low-pressure steam chamber (partition sleeve, partition) installed in the low-pressure inner cylinder has different expansion differences due to temperature differences during operation, and the position where the steam seal ring is arranged can have large axial and radial displacement.

[0005] Currently, there are no matching or production lines available for movable steam seal rings used in the low-pressure modules of nuclear power turbines. Utility Model Content

[0006] This invention provides a movable steam seal ring for nuclear power low-pressure modules to overcome existing technologies. It addresses the limitations of existing steam seal rings in simultaneously meeting the requirements of axial and radial displacement caused by the difference in expansion between the two components during operation, as well as the inability to arrange them in confined spaces.

[0007] A movable steam seal ring for a nuclear power low-pressure module includes an upper half ring, a lower half ring, and a connecting assembly. The upper and lower half rings have the same structure, and the upper half ring is connected to the lower half ring through the connecting assembly to form a circular ring. The connecting assembly includes a connecting piece, a sleeve, and a fastener. The upper and lower half rings are respectively provided with mounting holes at both ends. A sleeve is installed on one side of each mounting hole. When the upper and lower half rings are mated, the other side of the two mounting holes at the mating ends is provided with a connecting piece. Each connecting piece is provided with a connecting hole at both ends. The fastener passes through the connecting hole and is screwed into the internal thread hole of the sleeve. The axes of the mounting hole, the connecting hole, and the sleeve are all parallel to the axis of the circular ring.

[0008] Furthermore, support members are provided on the outer sides of both ends of the lower half ring near the dividing surface. The support members include pads and screws. The pads are placed in the grooves on the outer side of the lower half ring, and the screws are screwed into the internal threaded holes of the pads. The axis of the screws is perpendicular to the axis of the circular ring.

[0009] Furthermore, a retaining washer is provided between the fastener and the connecting piece, and a retaining hole is provided on the connecting piece to accommodate the retaining washer. The fastener passes through the retaining washer and the connecting hole and is screwed into the internal thread hole of the sleeve.

[0010] Furthermore, both the upper and lower halves of the ring include integrally formed reinforcing ribs and sealing arc segments, with sealing arc segments connecting both ends of the reinforcing ribs. The reinforcing ribs and sealing arc segments form a rounded transition, with the rounded arc pointing inwards.

[0011] The advantages of this utility model compared to the prior art are:

[0012] 1. Compared with traditional steam seal rings, the steam seal ring of this application is not fitted onto the steam chamber (diaphragm sleeve, diaphragm) and can be installed separately, reducing the installation difficulty of the working part sleeve. It allows for large axial and radial displacement of the cylinder and steam chamber (diaphragm sleeve, diaphragm) during unit operation. The seal remains effective even when both parts (low-pressure inner cylinder and low-pressure steam chamber or diaphragm sleeve, diaphragm) undergo axial and radial displacement simultaneously.

[0013] 2. The gas seal ring of this application does not adopt the traditional inlay design, and can be maintained independently during maintenance, saving maintenance time and improving maintenance efficiency.

[0014] 3. The steam seal ring of this application does not adopt the traditional spring plate push design structure, which effectively reduces the complexity of the steam seal ring and reduces manufacturing and maintenance costs.

[0015] 4. In this application, a positioning pin is provided on the inner arc side of the steam seal ring to increase the limit and prevent the steam seal ring from flipping. Attached Figure Description

[0016] Figure 1 This is a front view of the movable steam seal ring used in the low-pressure module of a nuclear power plant according to this application;

[0017] Figure 2 for Figure 1 Enlarged view of point A in the image;

[0018] Figure 3 for Figure 2 View B in the middle;

[0019] Figure 4 This is a schematic diagram showing the upper and lower halves of the circle connected by a connecting component at the midpoint.

[0020] Figure 5 for Figure 4 The C-direction view in the middle;

[0021] Figure 6 for Figure 4 The view in direction D;

[0022] Figure 7 This is a diagram illustrating the installation of the locating pin.

[0023] Figure 8 For along Figure 7A cross-sectional view of the EE line;

[0024] Figure 9 A structural diagram showing the upper or lower half of the circle;

[0025] Figure 10 This is a schematic diagram of the connecting piece.

[0026] Figure 11 This is a schematic diagram of the stop washer.

[0027] In the diagram: 1. Upper half circle, 11. Reinforcing rib segment, 12. Connecting arc segment, 2. Lower half circle, 3. Connecting assembly, 31. Connecting piece, 32. Sleeve, 33. Fastener, 4. Support component, 41. Pad, 42. Screw, 43. Washer, 5. Locking washer, 6. Locating pin, 7. Low-pressure inner cylinder, 8. Low-pressure steam chamber, a. Mounting hole, b. Connecting hole, c. Groove, d. Locking hole, e. Mounting arc surface. Detailed Implementation

[0028] The technical solution of this utility model is not limited to the specific implementation schemes listed below, but also includes any combination of the specific implementation schemes.

[0029] Reference Figures 1-11 A movable steam seal ring for a nuclear power low-pressure module includes an upper half ring 1, a lower half ring 2, and a connecting component 3; the upper half ring 1 and the lower half ring 2 have the same structure, and the upper half ring 1 is connected to the lower half ring 2 through the connecting component to form a circular ring.

[0030] The connecting assembly 3 includes a connecting piece 31, a sleeve 32, and a fastener 33. The upper half-ring 1 and the lower half-ring 2 each have mounting holes a at both ends. A sleeve 32 is installed on one side of each mounting hole a. When the upper half-ring 1 and the lower half-ring 2 are joined, a connecting piece 31 is provided on the other side of the two mounting holes a where the joining ends are located. Each connecting piece 31 has connecting holes b at both ends. The fastener 33 passes through the connecting holes b and is screwed into the internal threaded hole of the sleeve 32. The axes of the mounting holes a, connecting holes b, and sleeve 32 are all parallel to the axis of the circular ring. In this application, the upper and lower halves of the steam seal ring are connected by a connecting piece. The fasteners are hexagonal head bolts, locking washers with anti-loosening function, and spot-welded internal threaded sleeves fixed to the steam seal ring to achieve the connection between the upper and lower halves. Specifically, the connecting piece 31 is provided at the split surface, and the fastener 33 (e.g., hexagonal head bolts) is used for connection. This connection structure design can effectively reduce the amount of steam leakage generated at the split surface.

[0031] Using a cross-section similar to a bone knot, for example, refer to Figure 9The upper half-ring 1 and the lower half-ring 2 both include integrally formed reinforcing ribs 11 and sealing arc segments 12, with sealing arc segments 12 connected to both ends of the reinforcing ribs 11. There is a rounded transition between the reinforcing ribs 11 and the sealing arc segments 12, with the arcs pointing inwards. This design of the steam seal ring structure allows it to penetrate deeply into the two parts requiring sealing (low-pressure inner cylinder 7 and low-pressure steam chamber 8 or diaphragm sleeve / diaphragm). The sealing surface is designed such that the sealing arc segment 12 is spherical and makes planar contact with the low-pressure inner cylinder 7 and low-pressure steam chamber 8, providing excellent sealing performance while allowing for significant axial and radial displacement of the cylinder and steam chamber (diaphragm sleeve / diaphragm). Even when both parts (low-pressure inner cylinder 7 and low-pressure steam chamber 8 or diaphragm sleeve / diaphragm) experience simultaneous axial and radial displacement during unit operation, the seal remains effective. This solves the problem that traditional steam seals cannot simultaneously meet the requirements of axial and radial displacement. The sleeve 32 is spot-welded and fixed in the mounting holes a of the upper half-ring 1 and the lower half-ring 2. This design facilitates convenient installation, disassembly, and use.

[0032] For example, compared with the traditional AP1000 third-generation nuclear power turbine low-pressure module steam seal ring, the steam seal ring of this application does not adopt the design method of being embedded in one side of the sleeve at the location requiring sealing. Instead, it is arranged independently. The advantage of this design is that it can be installed and maintained separately, reducing the difficulty of installation and maintenance. It can also be maintained independently during maintenance, saving maintenance time and improving maintenance efficiency.

[0033] The gas seal ring in this application is designed with a flexible material, allowing for a certain amount of elastic deformation; for example, the material selected is ASTM A204GrB, but 12Cr13 or 15CrMoA can also be selected according to actual operating parameters.

[0034] In another embodiment, the steam seal ring of this application adopts a support member 4 design on the split surface, which can divide the steam seal ring into a combination structure of upper half ring 1 and lower half ring 2, making installation easier. Specifically, the support member 4 is provided on the outer sides of both ends of the lower half ring 2 near the split surface. The support member 4 includes a pad 41 and a screw 42. The pad 41 is placed in the groove c on the outer side of the lower half ring 2, and the screw 42 is screwed into the internal thread hole of the pad 41. The axis of the screw 42 is perpendicular to the axis of the circular ring.

[0035] Preferably, refer to Figure 2 The pad 41 has an L-shaped structure. It is formed by cutting an L-shaped portion off-center from a cylindrical body in the axial direction. The horizontal arm of the pad 41 is placed within the groove c, and the screw 42 is screwed into the internal threaded hole on the vertical arm. The pad 41 is installed on the lower half of the low-pressure cylinder 7 by the screw 42, thus enabling the horizontal arm on the pad 41 to support the lower half of the steam seal ring 2.

[0036] Meanwhile, positioning pins 6 are set on the inner arc sides of the upper half-circle 1 and the lower half-circle 2 relative to the mid-section surface to increase the limit and prevent the steam seal ring from overturning. Specifically, the inner middle part of the upper half-circle 1 and the lower half-circle 2 on both sides of the mid-section surface is provided with an installation arc surface e for arranging the positioning pins 6. Positioning pins 6 are set on the installation arc surface e for installation in the low-pressure steam chamber 8 or the partition or partition sleeve. While preventing overturning, this can increase the limit of the steam seal ring and make it easier to obtain the correct position during installation.

[0037] Reference Figure 4 and Figure 11 A retaining washer 5 is provided between the fastener 33 and the connecting piece 31. The connecting piece 31 is provided with a retaining hole d for accommodating the retaining washer 5. The fastener 33 passes through the retaining washer 5 and the connecting hole d and is screwed into the internal thread hole of the sleeve 32. With this configuration, during operation, after tightening the retaining washer 5, the retaining ear is tapped to prevent the fastener 33 from loosening.

Claims

1. A movable steam seal ring for a nuclear power low-pressure module, characterized in that: It includes an upper half circle (1), a lower half circle (2) and a connecting component (3); the upper half circle (1) and the lower half circle (2) have the same structure, and the upper half circle (1) is connected to the lower half circle (2) through the connecting component to form a circular circle; The connecting assembly (3) includes a connecting piece (31), a sleeve (32) and a fastener (33). The upper half ring (1) and the lower half ring (2) are respectively provided with mounting holes (a) at both ends. A sleeve (32) is installed on one side of each mounting hole (a). When the upper half ring (1) and the lower half ring (2) are connected, the other side of the two mounting holes (a) where the connecting ends are located is provided with a connecting piece (31). Each connecting piece (31) is provided with a connecting hole (b) at both ends. The fastener (33) passes through the connecting hole (b) and is screwed into the internal thread hole of the sleeve (32). The axes of the mounting hole (a), the connecting hole (b) and the sleeve (32) are all parallel to the axis of the circular ring.

2. The movable steam seal ring for a nuclear power low-pressure module according to claim 1, characterized in that: Support members (4) are provided on the outer sides of both ends of the lower half ring (2) near the split surface. The support member (4) includes a pad (41) and a screw (42). The pad (41) is placed in the groove (c) on the outer side of the lower half ring (2). The screw (42) is screwed into the internal thread hole of the pad (41). The axis of the screw (42) is perpendicular to the axis of the circular ring.

3. The movable steam seal ring for a nuclear power low-pressure module according to claim 1, characterized in that: A retaining washer (5) is provided between the fastener (33) and the connecting piece (31). The connecting piece (31) is provided with a retaining hole (d) for accommodating the retaining washer (5). The fastener (33) passes through the retaining washer (5) and the connecting hole (b) and is screwed into the internal thread hole of the sleeve (32).

4. The movable steam seal ring for a nuclear power low-pressure module according to claim 1, characterized in that: The upper half circle (1) and lower half circle (2) on both sides of the split surface are provided with mounting arc surfaces (e) for arranging positioning pins (6).

5. The movable steam seal ring for a nuclear power low-pressure module according to claim 2, characterized in that: The pad (41) has an L-shaped structure, with the horizontal arm of the pad (41) placed in the groove (c), and the screw (42) screwed into the internal thread hole on the vertical arm.

6. The movable steam seal ring for a nuclear power low-pressure module according to claim 1, characterized in that: The upper half ring (1) and the lower half ring (2) each include an integrally made reinforcing rib (11) and a sealing arc segment (12), with the sealing arc segment (12) connected to both ends of the reinforcing rib (11).

7. The movable steam seal ring for a nuclear power low-pressure module according to claim 6, characterized in that: There is a circular arc transition between the reinforcing rib (11) and the sealing arc segment (12), and the circular arc is set inward.

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