A sealing structure for a small reactor once-through steam generator

Abstract

The utility model discloses a kind of sealing structure for small reactor direct current steam generator, it is related to pressure vessel sealing technical field, solve the problem that small reactor direct current steam generator sealing structure is prone to sealing failure, leakage and maintenance difficulty.This utility model includes head, water inlet pipe and tube sheet, head is sleeved on water inlet pipe and is connected with tube sheet;Water inlet pipe one end is provided with recess structure, sealing groove one is set on tube sheet, recess structure is inserted into sealing groove one, sealing ring is set between recess structure and sealing groove one;Recess structure is right trapezoidal groove, sealing ring is D type sealing ring, the inclined inner wall of recess structure and the bevel of sealing ring contact.The utility model is decomposed into vertical direction force and horizontal direction force by the special-shaped sealing ring structure and recess structure set, when displacement or rebound occurs in water inlet pipe, still can guarantee sealing effect.

Description

TECHNICAL FIELD

[0001] The utility model relates to pressure vessel sealing technical field, concretely is a kind of sealing structure for small reactor once-through steam generator. BACKGROUND

[0002] Small reactor benefits from its small size, flexibility, safety and other advantages, and is increasingly widely used in the field of nuclear power ships, among which once-through steam generator is used to convert the heat energy generated by the reactor into steam to drive the steam turbine to generate electricity.

[0003] However, small reactor steam generator has some problems due to its small size, one of which is difficult maintenance and repair.

[0004] The existing once-through steam generator cold side medium enters the heat exchange pipe from the upper part of the equipment, and returns to the upper part after descending to the bottom, so the upper pipe box of the equipment needs to have two chambers, the inlet side and the outlet side. The two chambers are generally formed by welding and cannot be disassembled. After searching, the U-shaped double-wall heat transfer pipe once-through steam generator with publication number CN114543556A, the once-through steam generator with publication number CN107274946A, the multi-unit tube type once-through steam generator with publication number CN107143833A, and the lead-bismuth reactor once-through steam generator with publication number CN115440401B all adopt such a structure.

[0005] Once the heat exchange pipe of the above steam generator leaks or clogs, it will be difficult to replace and repair. Using a detachable sealing structure instead of the original welded structure can solve the problem of maintenance, but the operating conditions of small reactor once-through steam generator are relatively complex, with high operating temperature and pressure, and the existing sealing structure is prone to sealing failure and leakage.

[0006] In summary, in order to meet the maintenance and repair requirements of small reactor once-through steam generator, it is necessary to develop an innovative high-performance sealing structure to solve the technical problems in the current nuclear energy field. INVENTION CONTENTS

[0007] The utility model discloses in order to solve the above-mentioned existing small reactor once-through steam generator sealing structure easy to appear sealing failure, leakage and maintenance difficult problem, hereby proposes a kind of sealing structure for small reactor once-through steam generator. The utility model discloses special-shaped sealing ring structure and groove structure are set, the compression force received by sealing ring is decomposed into vertical force and horizontal force, when water inlet connector occurs displacement or rebound, still can guarantee sealing effect.

[0008] The utility model provides a sealing structure for small reactor once-through steam generator, it specifically includes the head, water inlet connector and tube sheet, and the head is sleeved on the water inlet connector and is connected with the tube sheet, the recess structure is provided with the groove one on the tube sheet, and the recess structure is inserted into the groove one, and the sealing ring is arranged between the recess structure and the groove one.

[0009] Further, the recess structure is a right-angled trapezoid, and the long bottom of the right-angled trapezoid is the recess opening, and the oblique edge inner wall contacts the sealing ring.

[0010] Further, the angle between the oblique edge inner wall of the recess structure and the vertical direction is 28 degrees.

[0011] Further, the oblique edge inner wall of the recess structure and the recess bottom corner are provided with a circular groove.

[0012] Further, the upper half of the sealing ring is a right-angled trapezoid, and the lower half is a semicircle, and the oblique edge of the right-angled trapezoid contacts the oblique edge inner wall of the recess structure.

[0013] Further, the angle between the oblique edge of the right-angled trapezoid of the sealing ring and the vertical direction is 30 degrees.

[0014] Further, the head and the tube sheet are both provided with a sealing groove two, and the sealing groove two is provided with an octagonal pad.

[0015] Further, the sealing groove two is a trapezoidal groove.

[0016] Further, the sealing groove one is a rectangular groove.

[0017] Further, the head is provided with a steam outlet connector.

[0018] The sealing structure for small reactor once-through steam generator has the following advantages:

[0019] (1) The sealing structure for small reactor once-through steam generator can solve the problems of sealing failure and leakage of the existing small reactor once-through steam generator, and the contact between the trapezoidal slope inside the recess structure and the slope on the sealing ring can decompose the compression force on the sealing ring into the vertical force and the horizontal force, so that the sealing effect can be ensured when the water inlet connector is displaced or rebounds.

[0020] (2) The sealing structure for small reactor once-through steam generator is provided with a sealing groove two at the position of the head and the tube sheet flange connection, and the sealing groove two is provided with an octagonal pad, so that an auxiliary sealing structure is formed to strengthen the sealing effect. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and are used to interpret the illustrative embodiments of the present application and their descriptions, and do not constitute improper limitations on the present application.

[0022] In the drawings:

[0023] Figure 1 is a structural schematic view of a sealing structure for a small reactor once-through steam generator according to the present application;

[0024] Figure 2 is a structural schematic view of a sealing ring and groove structure cooperation of a sealing structure for a small reactor once-through steam generator according to the present application;

[0025] Figure 3 is a sectional schematic view of a groove structure of a sealing structure for a small reactor once-through steam generator according to the present application;

[0026] Figure 4 is a sectional schematic view of a sealing ring of a sealing structure for a small reactor once-through steam generator according to the present application;

[0027] Figure 5 is a local enlarged view and force schematic view of a sealing structure for a small reactor once-through steam generator according to the present application at I;

[0028] Wherein: 1 - head, 2 - water inlet pipe interface, 3 - steam outlet pipe, 4 - tube sheet, 5 - octagonal pad, 6 - groove structure, 7 - sealing groove one, 8 - sealing ring, 9 - sealing groove two. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In the description of the utility model, it needs to be explained that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second" and "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0031] In the description of the utility model, it needs to be explained that unless otherwise explicitly specified and limited, the terms "mounting", "connection" and "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication between two elements. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0032] In addition, the technical features involved in the different embodiments of the utility model described below can be combined with each other as long as there is no conflict between them.

[0033] Specific implementation method one: see Figures 1-5 Specific description of this embodiment. The sealing structure for small reactor once-through steam generator specifically comprises a head 1, a water inlet pipe 2 and a tube sheet 4, the head 1 is sleeved on the water inlet pipe 2 and is connected at C in the middle by welding, the head 1 is provided with a flange, and is connected with the tube sheet 4 through the flange and the bolt; the shape of the head 1 is oval; one end of the water inlet pipe 2 is provided with an annular groove structure 6, which is connected at D in the middle by welding, the tube sheet 4 is provided with a sealing groove 7, the groove structure 6 is inserted into the sealing groove 7, and a sealing ring 8 is arranged between the groove structure 6 and the sealing groove 7; the sealing groove 7 is a rectangular groove. Figure 1 Figure 2 The inner groove cross section shape of the groove structure 6 is a right trapezoid; the long bottom of the right trapezoid is the groove opening, the distance between the inclined inner wall and the axis of the water inlet pipe 2 is less than the distance between the right-angled inner wall and the axis of the water inlet pipe 2; the inclined inner wall is in contact with the sealing ring 8.

[0034] The angle between the inclined inner wall of the groove structure 6 and the vertical direction is 28 degrees.

[0035] The angle between the inclined inner wall of the groove structure 6 and the vertical direction is 28 degrees.

[0036] ​The inclined inner wall of the groove structure 6 and the groove bottom corner are provided with a circular groove, so that when sealing, damage caused by the contact and extrusion of the inclined inner wall and the sealing ring 8 is avoided, as shown in Figure 3 The material of the groove structure 6 is steel material with high temperature resistance and excellent resilience.

[0037] The sealing ring 8 is a D-shaped sealing ring, the upper half of the cross section is a right-angled trapezoid, the lower half is a semicircle, the plane of the semicircle part is connected with the long bottom edge plane of the right-angled trapezoid part, and the inclined edge part of the right-angled trapezoid of the sealing ring 8 is in contact with the inclined inner wall inside the groove structure 6.

[0038] The included angle between the inclined edge part of the right-angled trapezoid of the sealing ring 8 and the vertical direction is 30 degrees.

[0039] The flange of the sealing head 1 and the tube plate 4 are both provided with a sealing groove two 9, and an octagonal gasket 5 is arranged in the sealing groove two 9; the sealing groove two 9 is a trapezoidal groove; under the extrusion of the sealing head 1 and the tube plate 4, auxiliary sealing is formed through the sealing groove two 9 and the octagonal gasket 5.

[0040] The sealing head 1 is provided with a steam outlet connecting pipe 3.

[0041] The specific working principle of the sealing structure for the small reactor once-through steam generator is as follows:

[0042] After the contact surface of the groove structure 6 and the sealing ring 8 is tightened, a small displacement is generated in the elastic range of the material, at this time, the included angle between the sealing surface and the vertical direction is between 28° and 30°, the compression force F of the groove structure 6 on the sealing ring can be decomposed into a horizontal direction F x and a vertical direction F y ′, the compression force F y ′ of point B is F y , so that the sealing of points A and B can be realized, as shown in the accompanying drawings. Figure 5

[0043] At the same time, as shown in the accompanying drawings, Figure 5 it can be known that, due to the elastic deformation of the contact surface of the groove structure 6 and the sealing ring 8, when the water inlet connecting pipe 2 is displaced upward along the axial direction or inward along the radial direction under the action of a certain load, the side in contact with the groove structure 6 and the sealing ring 8 will rebound, continue to compress point A on the sealing ring 8, thereby compressing point B, and the sealing effect is ensured; when the displacement is downward along the axial direction or outward along the radial direction, the self-tightening sealing effect is generated.

[0044] ​Summarize the above implementation case, the sealing structure for small reactor once-through steam generator, solve the existing small reactor once-through steam generator sealing structure easily appear sealing failure, leakage problem, through the trapezoidal slope in the groove structure 6 inside and the slope on the sealing ring 8 contact, the sealing ring 8 received the compression force is decomposed into vertical force and horizontal force, when the water inlet pipe 2 displacement or rebound, still can guarantee sealing effect. The sealing structure for small reactor once-through steam generator, still be provided with sealing groove two in the position of the head and the tube plate flange connection, sealing groove two is provided with octagonal pad, forms auxiliary sealing structure, strengthens sealing effect.

[0045] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A seal structure for a small reactor once-through steam generator, characterized by: The application relates to a water inlet pipe joint structure of a heat exchanger, which comprises a cover (1), a water inlet pipe (2) and a tube plate (4), the cover (1) is sleeved on the water inlet pipe (2) and connected with the tube plate (4), the water inlet pipe (2) is provided with a groove structure (6) at one end, the tube plate (4) is provided with a sealing groove (7), the groove structure (6) is inserted into the sealing groove (7), and a sealing ring (8) is arranged between the groove structure (6) and the sealing groove (7).

2. The seal structure for a small-sized reactor once-through steam generator according to claim 1, characterized by: The inner groove of the groove structure (6) is in the shape of a right-angled trapezoid; the long bottom of the right-angled trapezoid is the groove opening, and the inner wall of the inclined side is in contact with the sealing ring (8).

3. The seal structure for a small-sized reactor once-through steam generator according to claim 2, characterized by: The included angle between the inner wall of the inclined side of the groove structure (6) and the vertical direction is 28 degrees.

4. The seal structure for a small-sized reactor once-through steam generator according to claim 2 or 3, characterized by: The inner wall of the inclined side of the groove structure (6) is provided with a circular groove at a corner of the bottom of the groove.

5. The seal structure for a small-sized reactor once-through steam generator according to claim 2, characterized by: The upper half of the cross section of the sealing ring (8) is in the shape of a right-angled trapezoid, and the lower half is in the shape of a semicircle; the inclined side of the right-angled trapezoid is in contact with the inner wall of the inclined side of the groove structure (6).

6. The seal structure for a small-sized reactor once-through steam generator according to claim 5, characterized by: The included angle between the inclined side of the right-angled trapezoid of the sealing ring (8) and the vertical direction is 30 degrees.

7. The seal structure for a small-sized reactor once-through steam generator according to claim 1, characterized by: The cover (1) and the tube plate (4) are both provided with a sealing groove (9), and an octagonal gasket (5) is arranged in the sealing groove (9).

8. The seal structure for a small-sized reactor once-through steam generator according to claim 7, characterized by: The sealing groove (9) is a trapezoidal groove.

9. The seal structure for a small-sized reactor once-through steam generator according to claim 1, characterized by: The sealing groove (7) is a rectangular groove.

10. The seal structure for a small-sized reactor once-through steam generator according to claim 1, characterized by: The cover (1) is provided with a steam outlet pipe (3).

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