Sealing device for conical pipe orifice

Abstract

The invention relates to the technical field of nuclear power, in particular to a sealing device for a conical pipe orifice, which comprises a connecting pipe assembly and an L-shaped hook, the connecting pipe assembly is formed by welding a large circular plate, a connecting pipe and a small circular plate, the large circular plate and the small circular plate are respectively positioned at the upper end and the lower end of the connecting pipe, and the large circular plate is of a shouldered structure consisting of a circular disc and a barrel shoulder; a plurality of through holes are formed in the circumference of the disc at equal intervals, grooves are formed in the inner walls of the through holes, O-shaped rings A are installed in the grooves, grooves are formed in the outer wall of the shell ring, and O-shaped rings B are installed in the grooves. Except the O-shaped sealing ring, other parts are mechanical parts, the reliability is high, the application of the radial O-shaped sealing ring enables the long arm of the L-shaped hook piece and the cylindrical connecting pipe to perform axial displacement, the assembly of the L-shaped hook piece and the connecting pipe assembly is effectively solved, a low-hardness non-metal gasket is arranged on the stress contact surface of the device and the pipe orifice of the voltage stabilizer, and the damage of an equipment body is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power, in particular to a sealing device for a tapered pipe mouth. Background Art

[0002] The AP1000 is an advanced, passive, third-generation pressurized water reactor (PWR) nuclear power technology that has been rapidly developed in China. The pressurizer is a key component of the primary circuit in the AP1000 nuclear island and is the primary device for controlling pressure fluctuations in the reactor coolant system. After manufacture, the pressurizer is typically filled with nitrogen at a pressure of 20kPa to 350kPa, with a dew point less than -28.9°C and an oxygen content less than 1.0%, for transportation and on-site storage. This is to prevent oxidation of the metal inside the pressurizer and maintain cleanliness. One of the exposed pipe openings in the AP1000 pressurizer is conical in shape, making it impossible to seal the pipe with conventional clamps or flange gaskets. Furthermore, during pressurizer operation, hydrogen is injected into the containment tank to control the oxygen content in the primary circuit water during irradiation. This requires preventing leakage of primary circuit hydrogen through the pressurizer safety valve.

[0003] For example, the existing water seal device disclosed in Patent No. CN201811476988.3 utilizes a U-tube cold water seal structure located on the process pipeline connecting the pressurizer upper head to the safety valve. During pressurizer startup and operation, saturated water vapor within the pressurizer condenses within the U-tube cold water seal structure. When the condensed water level rises above the lowest point on the upper surface of the U-tube inner wall, the water seal is established. This pressurizer water seal device can effectively reduce hydrogen leakage from the vapor phase within the pressurizer. However, the U-tube cold water seal is located outside the pressurizer upper head, where the condensate inside is at a low temperature. When the pressurizer safety valve is opened, the discharge pipeline downstream of the safety valve is subjected to high hydraulic loads, and the U-tube cold water seal also takes up considerable layout space. A water seal structure with a thermowell connecting the safety end of the pressurizer safety valve pipe and an elbow creates a water seal by utilizing the heat released by saturated water vapor through the pressurizer safety valve, the pipe, and the safety end, preventing hydrogen leakage. This structure is simple and easy to manufacture. A high-temperature water seal is formed, and the condensate temperature within the water seal system is high, effectively reducing the hydraulic load on the discharge pipeline downstream of the safety valve when the safety valve is opened. The thermowell reduces fatigue caused by fluid temperature differences. The thermowell and elbow-type water seal structure has a small volume and quickly forms a water seal. The safety end and elbow of the pressurizer safety valve pipe with a thermowell are located inside the pressurizer upper head body, saving layout space outside the pressurizer. The boss effectively supports the thermowell.

[0004] Although the above solution improves some problems by connecting the safety end of the safety valve pipe with a thermo-sleeve and the water seal structure of the elbow, the solution is mainly designed for the internal water seal structure of the regulator, and still does not solve the technical problem that the conical exposed pipe in the AP1000 type regulator cannot be sealed by conventional clamps or flange gaskets. Summary of the Invention

[0005] In view of the problems in the prior art, the present invention provides a sealing device for a tapered pipe mouth.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a sealing device for a tapered pipe mouth, including a pipe assembly and an L-shaped hook, the pipe assembly is welded by a large circular plate, a pipe and a small circular plate, the large circular plate and the small circular plate are respectively located at the upper and lower ends of the pipe, the large circular plate is a shoulder structure composed of a disc and a barrel shoulder, a plurality of through holes are evenly spaced on the circumference of the disc, a groove is formed on the inner wall of the through hole and an O-ring A is installed in the groove, a groove is formed on the outer wall of the barrel section and an O-ring B is installed in the groove, a plurality of through holes are evenly spaced on the circumference of the small circular plate, the number of through holes on the small circular plate is the same as the number of through holes on the disc and corresponds one to one, the upper end of the pipe is sleeved with a non-metallic liner A, the upper end of the non-metallic liner A is against the lower end of the large circular plate;

[0007] The L-shaped hook is welded by a stud and a short arm steel plate. The lower end of the stud is rod-shaped, the outer side of the upper end of the stud is provided with a thread and the end is fixedly connected to a rectangular parallelepiped. The short arm steel plate is processed from a steel plate. A through hole is opened on one side of the short arm steel plate and is sleeved on the lower end of the stud through the through hole. A concave platform is provided on the other side of the short arm steel plate and a non-metallic liner B is provided on the upper end of the concave platform.

[0008] Specifically, the connecting pipe is a cylindrical structure, and the outer diameter of the connecting pipe is the same as the outer diameter of the small circular plate.

[0009] Specifically, the upper end of the stud passes through the through hole on the small circular plate and the through hole on the disc in sequence, and the upper end of the stud is sequentially sleeved with a thin nut, a nut and a spacer from top to bottom.

[0010] Specifically, a screw hole is formed at the lower end of the recessed platform and a screw is threadedly connected in the screw hole. The upper end of the screw passes through the screw hole and is threadedly connected to the lower end of the non-metallic gasket B.

[0011] Beneficial effects of the present invention:

[0012] (1) Except for the O-ring, all other parts are mechanical parts with high reliability;

[0013] (2) The application of radial O-rings enables the long arm of the L-shaped hook and the tubular pipe to move axially, effectively solving the assembly problem of the L-shaped hook and the pipe assembly;

[0014] (3) Install a low-hardness non-metallic liner on the contact surface between the device and the stabilizer nozzle to prevent damage to the device body;

[0015] (4) The O-ring structure solves the problem that the narrow end tapered nozzle cannot achieve annular and axial sealing on the body;

[0016] (5) Two O-ring groove structures are set on the device to achieve radial sealing inside and outside the pipe mouth, ensuring double sealing insurance;

[0017] (6) A simple and convenient device is used to achieve sealing without changing the original body structure or increasing the difficulty of processing and manufacturing;

[0018] (7) Using an extended screw to achieve remote operation from the outside where the internal space cannot be entered, and using the structure of the device to ensure accurate positioning without visual inspection;

[0019] (8) A double nut anti-loosening structure is set to ensure the sealing reliability of the device under long-term nitrogen filling conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and examples.

[0021] Figure 1 A cutaway view of the present invention;

[0022] Figure 2 for Figure 1 The regional map at position Ⅰ in the middle;

[0023] Figure 3 for Figure 1 The regional map at center Ⅱ;

[0024] Figure 4 It is a cross-sectional view of the large circular plate of the present invention;

[0025] Figure 5 This is a schematic structural diagram of the pipe assembly of the present invention;

[0026] Figure 6 This is a schematic diagram of the L-shaped hook structure of the present invention;

[0027] Figure 7 A top view of an L-shaped hook of the present invention;

[0028] Figure 8 Schematic diagram of the rotation positioning and fastening state structure during the assembly process of the present invention Figure 1 ;

[0029] Figure 9 Schematic diagram of the rotation positioning and fastening state structure during the assembly process of the present invention Figure 2 .

[0030] In the figure: 1. Stud; 2. Thin nut; 3. Nut; 4. Spacer; 5. Large round plate; 6. O-ring A; 7. Non-metallic gasket A; 8. O-ring B; 9. Connecting pipe; 10. Small round plate; 11. Non-metallic gasket B; 12. Screw; 13. Short arm steel plate. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0032] like Figures 1-9 As shown, the present invention provides a technical solution: a sealing device for a tapered pipe mouth, including a pipe assembly and an L-shaped hook, the pipe assembly is welded by a large circular plate 5, a pipe 9 and a small circular plate 10, the large circular plate 5 and the small circular plate 10 are respectively located at the upper and lower ends of the pipe 9, the large circular plate 5 is a shoulder structure composed of a disc and a barrel shoulder, a plurality of through holes are evenly spaced on the circumference of the disc, a groove is formed on the inner wall of the through hole and an O-ring A6 is installed in the groove, a groove is formed on the outer wall of the barrel section and an O-ring B8 is installed in the groove, a plurality of through holes are evenly spaced on the circumference of the small circular plate 10, the number of through holes on the small circular plate 10 is the same as the number of through holes on the disc and corresponds one to one, the pipe 9 is a cylindrical structure, the outer diameter of the pipe 9 is the same as the outer diameter of the small circular plate 10, the upper end of the pipe 9 is sleeved with a non-metallic liner A7, and the upper end of the non-metallic liner A7 is against the lower end of the large circular plate 5;

[0033] The L-shaped hook is welded by a stud 1 and a short arm steel plate 13. The upper end of the stud 1 passes through the through hole on the small circular plate 10 and the through hole on the disc in sequence. The upper end of the stud 1 is sequentially sleeved with a thin nut 2, a nut 3 and a spacer 4 from top to bottom. The lower end of the stud 1 is rod-shaped, and a thread is provided on the outer side of the upper end of the stud 1 and the end is fixedly connected to a rectangular parallelepiped. The short arm steel plate 13 is processed from a steel plate. A through hole is provided on one side of the short arm steel plate 13 and is sleeved on the lower end of the stud 1 through the through hole. A concave platform is provided on the other side of the short arm steel plate 13 and a non-metallic gasket B11 is provided on the upper end of the concave platform. A screw hole is provided at the lower end of the concave platform and a screw 12 is threadedly connected to the screw hole. The upper end of the screw 12 passes through the screw hole and is threadedly connected to the lower end of the non-metallic gasket B11.

[0034] When the sealing device is working, first install the O-ring A6 and O-ring B8 in the disc groove of the large circular plate 5 and the outer groove of the cylinder section respectively, fix the non-metallic liner B11 to the concave platform of the short arm steel plate 13 by screw 12, then pass the stud 1 through the through hole on the small circular plate 10 and the disc in turn, install the nut 3 and thin nut 2, rotate the stud 1 to shrink the short arm steel plate 13 to the outer diameter of the pipe 9, insert the device into the tapered pipe mouth of the stabilizer, make the small circular plate 10 flush with the end of the inner pipe, and the large circular plate 5 covers the pipe. Outside the mouth, the spacer 4 is placed under the large circular plate 5, and the stud 1 is rotated to screw the short arm steel plate 13 out of the inner extending pipe, and the nut 3 and the thin nut 2 are tightened. The short arm steel plate 13 is pressed against the end of the inner extending pipe through the non-metallic liner B11 by the pulling force of the stud 1, and the large circular plate 5 is pressed against the end of the outer pipe mouth through the spacer 4. At the same time, the O-ring A6 and the O-ring B8 are compressed and deformed to realize double-pass radial sealing. The non-metallic liner A7 and the non-metallic liner B11 avoid damage to the metal contact surface. The double nut anti-loosening structure ensures long-term reliable sealing.

[0035] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above-described embodiments. The above-described embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A sealing device for a tapered pipe opening, comprising a pipe assembly and an L-shaped hook, characterized in that: The pipe assembly is welded together by a large circular plate (5), a pipe (9) and a small circular plate (10), the large circular plate (5) and the small circular plate (10) being respectively located at the upper and lower ends of the pipe (9), the large circular plate (5) being a shoulder structure composed of a disc and a barrel shoulder, a plurality of through holes being evenly spaced on the circumference of the disc, a groove being formed on the inner wall of the through hole and an O-ring A (6) being installed in the groove, a groove being formed on the outer wall of the barrel section and an O-ring B (8) being installed in the groove, a plurality of through holes being evenly spaced on the circumference of the small circular plate (10), the number of through holes on the small circular plate (10) being the same as the number of through holes on the disc and corresponding to each other, the upper end of the pipe (9) being sleeved with a non-metallic liner A (7), the upper end of the non-metallic liner A (7) being against the lower end of the large circular plate (5); The L-shaped hook is welded by a stud (1) and a short arm steel plate (13). The lower end of the stud (1) is rod-shaped. The outer side of the upper end of the stud (1) is provided with a thread and the end is fixedly connected to a rectangular parallelepiped. The short arm steel plate (13) is processed from a steel plate. A through hole is opened on one side of the short arm steel plate (13) and is sleeved on the lower end of the stud (1) through the through hole. A concave platform is provided on the other side of the short arm steel plate (13) and a non-metallic liner B (11) is provided on the upper end of the concave platform.

2. A sealing device for a tapered pipe orifice according to claim 1, characterized in that: The connecting pipe (9) is a cylindrical structure, and the outer diameter of the connecting pipe (9) is the same as the outer diameter of the small circular plate (10).

3. The sealing device for a tapered pipe orifice according to claim 1, characterized in that: The upper end of the stud (1) passes through the through hole on the small circular plate (10) and the through hole on the disc in sequence, and the upper end of the stud (1) is sequentially sleeved with a thin nut (2), a nut (3) and a spacer (4) from top to bottom.

4. The sealing device for a tapered pipe orifice according to claim 1, characterized in that: A screw hole is provided at the lower end of the recessed platform, and a screw (12) is threadedly connected in the screw hole. The upper end of the screw (12) passes through the screw hole and is threadedly connected to the lower end of the non-metallic liner B (11).

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