Universal nuclear power heat exchanger tube bundle fragmented wrapping protection device and protection method

Abstract

The invention discloses a universal nuclear power heat exchanger tube bundle fragmentation type wrapping protection device and method, in the device and method, the protection device is arranged to be a plurality of small protection plates, the size of the protection plates is small enough, the size of the protection plates is light enough, so that the protection plates can enter and exit a manhole smoothly, and the protection device is allowed to be disassembled and assembled multiple times; and the plurality of protection plates are flexibly bound on the retaining ring through nylon ribbons, so that the heat exchange tube cannot be scratched, and the heat exchange tube can be protected.

Description

Technical Field

[0001] The present invention relates to a tube bundle wrapping protection device and a protection method for a nuclear power pressurized steam generator tube bundle part from the completion of the manufacturing process in a cleaning room to before the packaging of the steam generator. Background Art

[0002] The steam generator tube bundle assembly is the most important component in the steam generator. The tube bundle assembly is the heat exchange part of the entire steam generator during operation. The steam generator tube bundle is one of the core components of the steam generator, mainly responsible for transferring the heat of the primary coolant to the secondary feed water, heating the feed water to boiling, and generating dry saturated steam for driving the steam turbine after steam-water separation. The steam generator tube bundle usually consists of many tubes, which can be U-shaped tubes, straight tubes or other shapes. They are fixed on the tube sheet and are subjected to high temperature, high pressure, pressure difference inside and outside the tubes, as well as corrosion, hydraulic vibration and other working conditions during the heat exchange process.

[0003] In nuclear island heat exchange equipment, the heat exchange tubes are the first barrier to isolate radioactive substances, affecting the quality of the heat exchange tubes and related to the operation safety of nuclear power plants.

[0004] The steam generator heat transfer tubes are the boundary barrier between the primary side and the secondary side. The integrity of the heat transfer tubes is an important guarantee for nuclear safety. The thinning or even rupture of the heat exchange tube wall is an important reason for the failure of the steam generator tube bundle. Therefore, the protection during the manufacturing process of the heat exchange tubes has become an important part of affecting the integrity of the heat exchange tubes and reducing the damage of the heat exchange tubes, and is an important key technology for the manufacturing of steam generator products.

[0005] With the continuous increase of the capacity of nuclear power units and the gradual improvement of safety performance requirements, studying the protection of heat exchange tubes during the manufacturing process of steam generators can provide strong technical support for improving the manufacturing quality of nuclear power products and further improving the operation safety of nuclear power plants. In actual work, it is found that the hemispherical tube bundle head of nuclear power heat exchangers is the most vulnerable to subsequent work pollution, and it is most urgent to carry out protection design for it.

[0006] In summary, based on the complex conditions of the hemispherical tube bundle head of nuclear power heat exchangers, the inventor has designed a general nuclear power heat exchanger tube bundle segmented wrapping protection device and a protection method that can solve the above problems. Summary of the Invention

[0007] To overcome the above problems, the inventor of the present invention has conducted intensive research and designed a general-purpose segmented wrapping protection device and method for the tube bundle of a nuclear power heat exchanger. In this device and method, the protection device is set as multiple smaller protection plates. The size of the protection plates is small enough and the volume is light enough to facilitate entering and exiting the manhole smoothly, thereby allowing the protection device to be disassembled and installed multiple times. The multiple protection plates are all flexibly tied to the retaining ring by nylon ties, which can neither scratch the heat exchange tubes nor protect the heat exchange tubes, thus completing the present invention.

[0008] Specifically, the object of the present invention is to provide a general-purpose segmented wrapping protection device for the tube bundle of a nuclear power heat exchanger, and the protection device includes protection plates of various specifications;

[0009] All the protection plates are in the shape of thin plates, and the shape of their plate surfaces is an isosceles trapezoid or a rectangle. Circular through-holes 1 are opened at the edges of the plate surfaces of each protection plate, and the protection plates are tied and fixed to the retaining ring 8 by nylon ties passing through the circular through-holes 1.

[0010] Among them, waist-shaped through-holes 3 are also opened on the plate surfaces of the protection plates. By opening the waist-shaped through-holes 3, the weight of the protection plates is reduced, so that the mass of a single protection plate is not greater than 2 kg.

[0011] Among them, the diameter dimension of the waist-shaped through-hole 3 is φ20 mm;

[0012] Multiple waist-shaped through-holes 3 are opened on the protection plates, and the hole bridge distance between the multiple waist-shaped through-holes 3 is 15 - 25 mm;

[0013] Preferably, the length of the waist-shaped through-hole 3 is 300 mm or 130 mm.

[0014] Among them, the length of the upper bottom edge of the protection plate is less than the length of the lower bottom edge;

[0015] The protection plates of various specifications include a first protection plate 4, a second protection plate 5, a third protection plate 6, and a fourth protection plate 7;

[0016] The length of the lower bottom edge of the first protection plate 4 is less than the length of the upper bottom edge of the second protection plate 5;

[0017] The length of the lower bottom edge of the second protection plate 5 is less than the length of the upper bottom edge of the third protection plate 6;

[0018] The length of the lower bottom edge of the third protection plate 6 is less than the length of the upper bottom edge of the fourth protection plate 7;

[0019] When installing the protection plates, the first protection plate 4, the second protection plate 5, the third protection plate 6, and the fourth protection plate 7 are installed in sequence, and the obtained set of protection plates is in a spindle-like or olive-like shape after installation.

[0020] Among them, the distance between the protective plate and the anti-vibration strips 2 on both sides thereof is 15-30 mm;

[0021] The thickness of the protective plate does not exceed 2 mm, preferably 1.5 mm;

[0022] Preferably, the protective plate is a stainless steel plate.

[0023] Among them, 4 to 8 circular through holes 1 are opened on each protective plate, and the aperture size of the circular through holes 1 is φ15 mm;

[0024] The minimum distance between the center of the circular through hole 1 and the edge of the protective plate is 20-23 mm.

[0025] The present invention also provides a general method for segmentally wrapping and protecting the tube bundle of a nuclear power heat exchanger, and this method is realized by the general device for segmentally wrapping and protecting the tube bundle of a nuclear power heat exchanger described above.

[0026] Among them, this method includes the following steps:

[0027] Step 1, wrap a fireproof cloth around the tube bundle; on the outside of the heat exchange tube bundle, pass a nylon tie through the fireproof cloth and tie and fix the nylon tie on the retaining ring 8;

[0028] Step 2, install the segmental wrapping and protecting device on the outside of the fireproof cloth.

[0029] Among them, in Step 2, pass the nylon tie through the circular through hole 1 on the protective plate and tie and fix the nylon tie on the retaining ring 8.

[0030] Among them, in Step 2, protective plates of various specifications are sequentially tied between two adjacent anti-vibration strips 2; between two anti-vibration strips 2, the distance between two adjacent protective plates is 20 mm;

[0031] The distance between the protective plate and the anti-vibration strips 2 on both sides thereof is 15-30 mm.

[0032] The beneficial effects of the present invention include:

[0033] (1) According to the general device for segmentally wrapping and protecting the tube bundle of a nuclear power heat exchanger and the protection method provided by the present invention, considering that the working position of this device is inside the heat exchanger, it is set to be segmental, and the size and mass of each protective plate allow it to enter and exit the manhole multiple times, and thus it can be installed and removed multiple times to facilitate the production process of the overall structure of nuclear power equipment;

[0034] (2) According to the general nuclear power heat exchanger tube bundle segmented wrapping protection device and protection method provided by the present invention, waist-shaped through-hole structures are provided on the protection plates of the protection device. Considering the weight factor in its structure, it is convenient for manual operation by personnel, and at the same time, the protection effect is taken into account;

[0035] (3) According to the general nuclear power heat exchanger tube bundle segmented wrapping protection device and protection method provided by the present invention, the segmented structure enables the installed protection device to have a certain arc, adapting to the outer shape structure of the hemispherical tube bundle head;

[0036] (4) According to the general nuclear power heat exchanger tube bundle segmented wrapping protection device and protection method provided by the present invention, each protection plate can avoid the position of the retaining ring, preventing interference between the protection plate and the retaining ring. Description of the Drawings

[0037] Figure 1 Schematic diagram showing the structure when multiple protection plates of the general nuclear power heat exchanger tube bundle segmented wrapping protection device provided by the present application are spliced into a spindle-like shape;

[0038] Figure 2 Schematic diagram showing the structure of the first protection plate of the general nuclear power heat exchanger tube bundle segmented wrapping protection device provided by the present application;

[0039] Figure 3 Schematic diagram showing the structure of the second protection plate of the general nuclear power heat exchanger tube bundle segmented wrapping protection device provided by the present application;

[0040] Figure 4 Schematic diagram showing the structure of the third protection plate of the general nuclear power heat exchanger tube bundle segmented wrapping protection device provided by the present application;

[0041] Figure 5 Schematic diagram showing the structure of the fourth protection plate of the general nuclear power heat exchanger tube bundle segmented wrapping protection device provided by the present application;

[0042] Figure 6 Schematic diagram showing the structure when a set of the general nuclear power heat exchanger tube bundle segmented wrapping protection device described in the present application is installed on the hemispherical tube bundle head of a nuclear power heat exchanger;

[0043] Figure 7 Schematic diagram showing another structure after the protection plates on the steam generator in the embodiment of the present application are spliced.

[0044] Description of the Reference Numerals

[0045] 1 - Circular through-hole

[0046] 2 - Anti-vibration strip

[0047] 3 - Waist-shaped through-hole

[0048] 4 - First protective plate

[0049] 5 - Second protective plate

[0050] 6 - Third protective plate

[0051] 7 - Fourth protective plate

[0052] 8 - Retaining ring Detailed implementation mode

[0053] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more distinct.

[0054] The special term "exemplary" here means "serving as an example, embodiment or illustration". Any embodiment described as "exemplary" here does not have to be construed as superior or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0055] The present invention provides a general nuclear power heat exchanger tube bundle segmented wrapping protection device, as Figure 1 and Figure 6 shown in, the protection device is installed on the hemispherical tube bundle head of a nuclear power heat exchanger. Specifically, the hemispherical tube bundle head of the nuclear power heat exchanger includes a plurality of U-shaped heat exchange tubes, and the bending parts of the plurality of U-shaped heat exchange tubes are concentrated in the hemispherical area to form a hemispherical tube bundle head. A retaining ring 8 is provided between each layer of heat exchange tubes, and the retaining ring 8 extends out of the hemispherical tube bundle head. The extended part is fixedly connected to the anti-vibration strip 2, and the anti-vibration strip is an arc-shaped metal strip that surrounds the outside of the hemispherical tube bundle head.

[0056] The protection device in this application includes protective plates of various specifications; the specific quantity and specifications of the protective plates are determined according to the tube bundle size.

[0057] The protective plates are all in the shape of thin plates, and the shape of their plate surfaces is an isosceles trapezoid or a rectangle. Preferably, most of the protective plates are set as isosceles trapezoids, and the single protective plate at the central position can be set as a rectangle; circular through-holes 1 are opened at the edges of the plate surfaces of each protective plate, and the protective plates are tied and fixed to the retaining ring 8 through nylon cable ties passing through the circular through-holes 1. The protective plates are of a segmented structure, that is, each protective plate is very small relative to the area to be protected, and nearly a hundred protective plates are required to complete the protection of the protected area. These protective plates can be sequentially installed on the hemispherical tube bundle head to be protected and can be removed and reinstalled according to process requirements. In addition, this segmented structure enables the installed protective device to have a certain curvature, adapting to the outer shape structure of the hemispherical tube bundle head; during the actual construction and installation process, each protective plate can also avoid the position where the retaining ring is located, preventing interference between the protective plate and the retaining ring.

[0058] In a preferred embodiment, as Figure 2 、 Figure 3 、 Figure 4 and Figure 5 shown, waist-shaped through-holes 3 are also opened on the plate surfaces of the protective plates. By opening the waist-shaped through-holes 3, the weight of the protective plates is reduced, so that the mass of a single protective plate is not greater than 2 kg. The protective plates with such a mass are convenient for workers to disassemble and install, and also convenient for people to enter and exit the manhole, reducing the operation burden. More importantly, the protective device with a lighter weight can avoid deformation of the hemispherical tube bundle head and the retaining ring caused by excessive weight.

[0059] The diameter dimension of the waist-shaped through-hole 3 is φ20 mm; a plurality of waist-shaped through-holes 3 are opened on the protective plate, and the distance between the hole bridges of the plurality of waist-shaped through-holes 3 is 15 - 25 mm; preferably, the length of the waist-shaped through-hole 3 is 300 mm or 130 mm.

[0060] The size design of the waist-shaped through-hole 3 in the present application fully considers the construction process characteristics inside the spherical head, ensuring that the size of the waist-shaped through-hole will not affect the protection effect on the hemispherical tube bundle and can fully guarantee the safety of the hemispherical tube bundle.

[0061] In a preferred embodiment, all the edges of the protective plate are ground and rounded, without sharp corners or burrs, so as to prevent the protective plate from scratching the heat exchange tubes.

[0062] In a preferred embodiment, as Figure 1 shown, the length of the upper base of the protective plate is less than the length of the lower base; the various specifications of protective plates include a first protective plate 4, a second protective plate 5, a third protective plate 6, and a fourth protective plate 7;

[0063] The length of the lower base of the first protective plate 4 is less than the length of the upper base of the second protective plate 5;

[0064] The length of the lower bottom edge of the second protection plate 5 is less than the length of the upper bottom edge of the third protection plate 6;

[0065] The length of the lower bottom edge of the third protection plate 6 is less than the length of the upper bottom edge of the fourth protection plate 7;

[0066] When installing the protection plates, the first protection plate 4, the second protection plate 5, the third protection plate 6 and the fourth protection plate 7 are installed in sequence. After installation, the obtained set of protection plates is in a spindle-like or olive-like shape. The overall shape of the set of protection plates is similar to the shape between two adjacent anti-vibration strips, and can just cover and protect the area between two adjacent anti-vibration strips.

[0067] Preferably, the height dimensions of the first protection plate 4, the second protection plate 5, the third protection plate 6 and the fourth protection plate 7 are all set to 340 mm.

[0068] In a preferred embodiment, the side length dimension of the protection plate does not exceed 445 mm; this dimension design can ensure meeting the requirements for entering and exiting the manhole.

[0069] The distance between the protection plate and the anti-vibration strips 2 on both sides thereof is 15 - 30 mm; the thickness of the protection plate does not exceed 2 mm, preferably 1.5 mm; this thickness dimension can ensure that the protection plate has sufficient structural strength to meet the protection requirements, and can also ensure that the weight of the protection plate meets the set upper limit requirement, facilitating manual disassembly and transportation of the protection plate;

[0070] Preferably, the protection plate is a stainless steel plate. Specifically, the protection plate can be prepared by 06Cr19Ni10, which can meet the cleaning requirements of the protection plate.

[0071] In a preferred embodiment, 4 - 8 circular through-holes 1 are opened on each protection plate, and the aperture dimension of the circular through-holes 1 is φ15 mm;

[0072] The minimum distance between the center of the circular through-hole 1 and the edge of the protection plate is 20 - 23 mm. Setting the circular through-hole 1 to the above dimensions in this application can meet the connection strength requirements when fixing the protection plate, and can also take into account the convenience of the fixing operation.

[0073] The present invention also provides a general method for piecewise wrapping and protecting the tube bundle of a nuclear power heat exchanger, which is realized by the general piecewise wrapping and protecting device for the tube bundle of a nuclear power heat exchanger described above.

[0074] Specifically, the method includes the following steps:

[0075] Step 1, wrap a fireproof cloth around the tube bundle; specifically, the fireproof cloth is coated on the outside of the heat exchange tube bundle, and nylon ties are passed through the fireproof cloth and tied and fixed on the retaining ring 8;

[0076] Step 2: Install the segmented wrapping protection device outside the fireproof cloth.

[0077] Preferably, in Step 2, pass the nylon tie through the round through-hole 1 on the protection plate, and tie and fix the nylon tie on the retaining ring 8.

[0078] Preferably, in Step 2, protection plates of various specifications are successively tied between two adjacent anti-vibration strips 2; the distance between two adjacent protection plates is 20 mm between two anti-vibration strips 2;

[0079] The distance between the protection plate and the anti-vibration strips 2 on both sides thereof is 15 - 30 mm.

[0080] When the installation position and size of the protection plate are set to the above values in this application, the protection effect can be ensured to meet the use requirements, reliable protection can be provided for the inner tube bundle, and the convenience of installing the protection plate can also be taken into account.

[0081] Further, the number of protection plates between two adjacent anti-vibration strips 2 can be set to 6 or 8. When it is set to 6, specifically, two pieces of the second protection plate 5, the third protection plate 6, and the fourth protection plate 7 are selected respectively, as shown in Figure 6 ; at this time, at the position closer to the inside, since it is far from the head of the tube bundle and there are basically no operation processes, the first protection plate 4 at the outermost edge position can be omitted. If the number of protection plates is odd, the contour of the protection plate in the middle position is rectangular.

[0082] Embodiment

[0083] During the manufacturing process of the CAP 1000 steam generator, after the tube bundle assembly is completed with tube threading, the tube bundle is in an exposed state. At this time, the general nuclear power heat exchanger tube bundle segmented wrapping protection device provided by this application, as shown in Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , is used to protect the semi-spherical tube bundle head on the tube bundle assembly.

[0084] The specific operation process is as follows:

[0085] Step 1: Wrap the fireproof cloth around the tube bundle; outside the heat exchange tube bundle, pass the nylon tie through the fireproof cloth, and tie and fix the nylon tie on the retaining ring;

[0086] Step 2: Install the segmented wrapping protection device outside the fireproof cloth;

[0087] In Step 2, pass the nylon tie through the round through-hole on the protection plate, and then tie and fix the nylon tie on the retaining ring.

[0088] In step 2, the protection plates of various specifications are successively tied between two adjacent anti-vibration bars; between two anti-vibration bars, the distance between two adjacent protection plates is 20 mm.

[0089] The distance between the protection plate and the anti-vibration bars on its both sides is 15 - 30 mm.

[0090] After the hemispherical tube bundle head is protected by the above method, a total of 88 protection plates are used, and the effective coverage area is about 20.2 square meters. The coverage area is large enough to cover all areas where scuffing and knocking may occur. The total weight of the installed segmented wrapping protection device is 107 kg, and there is no deformation and no deflection in the hemispherical tube bundle head; two operators can complete the disassembly or installation operation of the segmented wrapping protection device in about 6 hours. The protection device between two adjacent anti-vibration bars is as Figure 1 Or Figure 7 shown in;

[0091] During the subsequent parking process, knocking occurred. Under the protection of the protection device, the tube bundle assembly was not scratched and the normal use was not affected. Finally, the manufacturing task of the CAP 1000 steam generator was successfully completed.

[0092] In addition, when the test piece is covered by the segmented wrapping protection device, the worker holds a steel pipe and strikes the segmented wrapping protection device with all his strength, and the test piece is not damaged, and there is no deformation and scratch on the surface.

[0093] The present invention has been described in combination with preferred embodiments above, but these embodiments are only exemplary and only serve an illustrative role. On this basis, various substitutions and improvements can be made to the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. A general nuclear power heat exchanger tube bundle segmented wrapping protection device, characterized in that, The protection device includes protection plates of various specifications; The protection plates are all in the shape of thin plates, and the shape of their plate surfaces is an isosceles trapezoid or a rectangle. Circular through-holes (1) are provided at the edges of the plate surfaces of each protection plate, and the protection plates are tied and fixed to the retaining ring (8) through nylon ties passing through the circular through-holes (1).

2. The general nuclear power heat exchanger tube bundle segmented wrapping protection device according to claim 1, characterized in that Waist-shaped through-holes (3) are also provided on the plate surfaces of the protection plates, and the waist-shaped through-holes (3) are provided to reduce the weight of the protection plates, so that the mass of a single protection plate is not greater than 2 kg.

3. The general nuclear power heat exchanger tube bundle segmented wrapping protection device according to claim 2, characterized in that The diameter size of the waist-shaped through-hole (3) is φ20 mm; A plurality of waist-shaped through-holes (3) are provided on the protection plate, and the distance between the hole bridges of the plurality of waist-shaped through-holes (3) is 15-25 mm; Preferably, the length of the waist-shaped through-hole (3) is 300 mm or 130 mm.

4. The general nuclear power heat exchanger tube bundle segmented wrapping protection device according to claim 1, characterized in that The length of the upper base of the protection plate is less than the length of the lower base; The protection plates of various specifications include a first protection plate (4), a second protection plate (5), a third protection plate (6) and a fourth protection plate (7); The length of the lower base of the first protection plate (4) is less than the length of the upper base of the second protection plate (5); The length of the lower base of the second protection plate (5) is less than the length of the upper base of the third protection plate (6); The length of the lower base of the third protection plate (6) is less than the length of the upper base of the fourth protection plate (7); When installing the protection plates, the first protection plate (4), the second protection plate (5), the third protection plate (6) and the fourth protection plate (7) are installed in sequence, and the obtained set of protection plates is in a quasi-spindle shape or a quasi-olive shape after installation.

5. The general nuclear power heat exchanger tube bundle segmented wrapping protection device according to claim 1, characterized in that The distance between the protection plate and the anti-vibration strips (2) on both sides thereof is 15-30 mm; The thickness of the protection plate does not exceed 2 mm, preferably 1.5 mm; Preferably, the protection plate is a stainless steel plate.

6. The general nuclear power heat exchanger tube bundle segmented wrapping protection device according to claim 1, characterized in that 4 to 8 circular through-holes (1) are provided on each protection plate, and the aperture size of the circular through-holes (1) is φ15 mm; The minimum distance between the center of the circular through-hole (1) and the edge of the protection plate is 20-23 mm.

7. A general method for piecewise wrapping and protecting the tube bundle of a nuclear power heat exchanger, characterized in that, This method is realized by the general nuclear power heat exchanger tube bundle segmented wrapping protection device described in claims 1-6.

8. The general nuclear power heat exchanger tube bundle segmented wrapping protection method according to claim 7, characterized in that, This method includes the following steps: Step 1, wrap a fireproof cloth around the tube bundle; outside the heat exchange tube bundle, pass a nylon tie through the fireproof cloth and tie and fix the nylon tie to the retaining ring (8); Step 2, install the segmented wrapping protection device outside the fireproof cloth.

9. The general nuclear power heat exchanger tube bundle segmented wrapping protection method according to claim 8, characterized in that In step 2, pass the nylon cable tie through the circular through-hole (1) on the protective plate, and tie and fix the nylon cable tie on the retaining ring (8).

10. The general nuclear power heat exchanger tube bundle segmented wrapping protection method according to claim 9, characterized in that In step 2, protective plates of various specifications are sequentially tied between two adjacent anti-vibration strips (2); between the two anti-vibration strips (2), the distance between two adjacent protective plates is 20 mm; The distance between the protective plate and the anti-vibration strips (2) on both sides thereof is 15-30 mm.

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