Internal vertical tube fixing device and fixing method for nuclear power steam generator

Abstract

The application discloses a fixing device and fixing method for vertical pipes in a nuclear power steam generator, which comprises a support clamping base, a universal block, a hinge base, a connecting shaft, a screw rod and a connecting nut. One side of the support clamping base is fixed to the outer wall of a straight pipe, and the other side is supported on the outer wall of a cross pipe through two groups of swingable hinge bases. The support clamping base is connected and pre-tightened by the screw rod, so that it is supported between two vertical pipes according to the shape of the pipes and is fixedly connected. The device has novel structure, is convenient to use and has strong universality. The device can be installed at any position in the narrow space of the complex vertical pipes in the steam generator to form radial support, so that the inner part is well fixed in the shell and rotates synchronously with the shell.

Description

Technical Field

[0001] This invention relates to the field of nuclear power steam generator manufacturing, and specifically to a temporary fixing device and method for fixing vertical tube assemblies inside a steam generator. Background Technology

[0002] The steam generator of a nuclear power plant is one of the main pieces of equipment in a nuclear reactor. It heats the water in the secondary loop with the nuclear reaction heat carried in the primary loop through the heat exchange tube 89 located at the bottom, forming high-temperature and high-pressure steam. The steam rises under pressure and is dried by the separator and dryer 84 before entering the turbine from the top to generate electricity.

[0003] The AP1000 type steam generator, a third-generation pressurized water reactor, has a meticulously designed internal structure. The equipment consists of two parts: an upper shell 81, a dryer 84, a separator, and a feedwater ring inside the separator; and a lower shell 83 and heat exchange tubes.

[0004] When manufacturing the AP1000 type steam generator for the third-generation pressurized water reactor, after the upper and lower parts of the evaporator equipment are manufactured, horizontal butt welding of the shell and internal components are carried out. The weld obtained from the shell welding is the main pressure-bearing weld of the equipment, which must be welded on both the inner and outer sides and subjected to multiple non-destructive testing.

[0005] like Figure 10 As shown, due to the limitations of the equipment structure, the internal operating space of the separator is extremely small after installation, making welding impossible. Therefore, during the manufacturing of the upper components, after the dryer and water supply ring are installed, the separator is assembled as shown... Figure 9 The separator is moved a certain distance towards the dryer so that there is enough operating space inside after the shell weld 88 is connected. After the weld is inspected and qualified, the separator is reset and the inner sleeve is welded to obtain the inner component weld, thus completing the equipment manufacturing.

[0006] The separator is a straight tube assembly composed of multiple straight tubes with cyclone blades on the inner side. The water supply ring is an annular horizontal tube installed in the middle of the separator's straight tubes and arranged perpendicularly to them. During the separator's manufacturing process, the water supply ring is placed inside but not fixedly connected to it. A uniform gap is provided between the horizontal tube of the water supply ring and the straight tube of the separator.

[0007] The internal components of the upper assembly are vertically mounted. After the dryer is installed, the separator and the water supply ring are as follows: Figure 11The separator is installed together as shown. Personnel enter the upper housing through the manhole to install and weld the water supply ring to the upper housing, securing it in place. The separator is then lowered to a temporary fixed height, and the upper assembly is laid down to prepare for docking with the lower assembly. During this stage, the separator should be placed coaxially with the housing, but structurally, there is approximately a 50mm circumferential gap between the separator and the housing. When the upper housing is flipped from an upright position to a horizontal position, the separator will shift downwards under its own weight and press against the water supply ring. During the rotation welding of the housing, the separator, not being properly secured, may collide with the water supply ring, causing eccentric torsion and resulting in separator misalignment and damage to parts, leading to quality issues.

[0008] Typically, temporary fixing of internal components in large containers can be achieved by welding temporary parts between the internal components and the shell. However, steam generators are Class I nuclear power plant equipment, and due to the special nature of the pressure-bearing shell material, arbitrary welding on its surface is not permitted. Furthermore, the manufacturing process of steam generators involves strict cleanliness requirements inside the shell, and temporary welding of internal fixing parts would generate a large amount of impurities such as welding flux, iron filings, and dust due to welding, cutting, and grinding. The internal structure of steam generators is complex and precise; once impurities enter the confined space, they are difficult to clean, causing significant contamination of the container's interior.

[0009] It is evident that coaxial fixation of the separator within the housing presents certain challenges, necessitating the design of a device and corresponding fixing method that enables the separator to be coaxially fixed within the housing via a non-welding method and rotate synchronously with the housing. Summary of the Invention

[0010] To overcome the aforementioned problems, the inventors conducted in-depth research and designed a fixing device and method for vertical tubes inside a nuclear power steam generator. The device includes a support bracket, a universal block, a hinge, a connecting shaft, a screw, and a connecting nut. One side of the support bracket is fixed to the outer wall of the straight tube, while the other side is supported on the outer wall of the horizontal tube by two sets of swingable hinges. The screw is pre-tightened to conform to the shape of the pipes and fix them between the two vertically aligned pipes. This device has a novel structure, is easy to use, and is highly versatile. It can be installed at any position within the confined space of the complex vertical pipes inside the steam generator to form radial support, ensuring that the internal components are well fixed within the shell and rotate synchronously with the shell, thus completing this invention.

[0011] Specifically, the purpose of this invention is to provide a fixing device between vertical tubes inside a nuclear power steam generator, the device including a support bracket 1, a universal block 2 and a hinge 3; One side of the support bracket 1 is a large arc surface 14, and the other side is hinged to the universal block 2. The support bracket 1 abuts against the straight tube 72 through the large arc surface 14. The universal block 2 is hinged to the support bracket 1 on one side and to the hinge bracket 3 on the other side, and the rotation directions of the two hinges are perpendicular to each other. The hinge seat 3 is hinged to the universal block 2 on one side, and two small arc surfaces 31 are provided on the other side. The hinge seat 3 abuts against the horizontal tube 71 through the small arc surfaces 31.

[0012] Two universal blocks 2 are hinged to the support bracket 1, and a hinge seat 3 is hinged to each universal block 2. That is, two hinge seats 3 are connected to one support bracket 1, so as to adapt to the curvature of the horizontal tube 71 and tighten the horizontal tube 71 through the hinge seat 3.

[0013] The device also includes a screw 5 and a connecting nut 6; the screw 5 and the connecting nut 6 connect two support brackets 1, and the distance between the two support brackets 1 can be adjusted according to the outer diameter of the horizontal tube 71.

[0014] Among them, on the support base 1, a recessed universal block connecting groove 11 is provided on the side opposite to the large arc surface 14, and one end of the universal block 2 can extend into the universal block connecting groove 11. The support bracket 1 is also provided with two connecting holes 12 that pass through the universal block connecting groove 11 vertically, and the connecting shaft 4 that is hinged can be inserted into the connecting hole 12. The end of the support bracket 1 is also provided with an inwardly recessed screw connection groove 13; the screw 5 can be embedded in the screw connection groove 13, and the support bracket 1 can be pushed to translate along the length direction of the screw 5 by pre-tightening the connection nut 6; Preferably, the radius of the large arc surface 14 is smaller than the radius of the straight tube 72.

[0015] When two universal blocks 2 are hinged in the universal block connecting groove 11, the maximum allowable angle for the universal block 2 to swing away from the other universal block 2 from the state perpendicular to the support base 1 is α, and the value of α is 10 to 20 degrees, preferably 15 degrees.

[0016] The universal block 2 includes a single plate end 21 that extends into the universal block connecting groove 11 and a double plate end 22 located outside the universal block connecting groove 11. The double-plate end 22 includes two parallel clamping plates, and the distance between the clamping plates allows the hinge end of the hinge seat 3 to extend in. Both the single-plate end 21 and the double-plate end 22 have through holes for the connecting shaft 4 to pass through. The single-plate end 21 and the double-plate end 22 are arranged perpendicularly to each other.

[0017] The hinge seat 3 has a hinge end 32 on one side, which is hinged to the universal block 2. The other side of the hinge 3 is a tube support end with two outwardly protruding small arc surfaces 31, and the two small arc surfaces 31 are connected by an inwardly concave arc structure.

[0018] The two support brackets 1 are used in a group, that is, the large arc surface 14 of the two support brackets 1 abuts against a straight tube 72; the hinges 3 connected to the two support brackets 1 abut against the two sides of the horizontal tube 71 independently, and the two support brackets 1 are tightened and fixed to each other by screws 5 and connecting nuts 6.

[0019] Among them, the straight tube 72 is a straight tube on the separator, there are multiple of them, and they are arranged in parallel to each other; The horizontal tube 71 is an annular tube on the water supply ring, which is arranged horizontally and embedded between multiple straight tubes 72.

[0020] The present invention also provides a method for fixing the internal vertical tubes of a nuclear power steam generator during horizontal rotation, which is achieved by the fixing device for the internal vertical tubes of the nuclear power steam generator described above.

[0021] The beneficial effects of this invention include: (1) According to the fixing device and fixing method between vertical tubes inside the nuclear power steam generator provided by the present invention, the device replaces the method of welding and fixing inside the container by mechanical connection support. The installation and removal are very convenient and clean, avoiding the internal pollution of the shell such as welding dust, flux fragments, cutting residue, iron filings and dust caused by grinding weld scars caused by the welding method, and improving the cleanliness of the container. (2) According to the fixing device and fixing method between vertical tubes inside the nuclear power steam generator provided by the present invention, the device has a compact structure and is easy to bring in and out of the shell through the manhole. It can be used in the narrow space inside the steam generator or large pressure vessel. (3) According to the fixing device and fixing method between the internal vertical tubes of the nuclear power steam generator provided by the present invention, the device provides stable support and has significant effect. It can achieve stable support and fixing of large vertical tubes with only a simple mechanism. (4) The fixing device and fixing method between the internal vertical tubes of the nuclear power steam generator provided by the present invention are highly versatile and can be used in various situations such as straight pipes, bent pipes, uneven gaps, and different pipe diameters by rotating the universal block and the hinge seat. Attached Figure Description

[0022] Figure 1 A three-dimensional structural schematic diagram of the fixing device between vertical tubes inside a nuclear power steam generator is shown. Figure 2 A three-dimensional structural diagram of the internal vertical tube fixing device of a nuclear power steam generator when used between straight and horizontal tubes is shown. Figure 3A top view of the internal vertical tube fixing device of a nuclear power steam generator is shown when it is used between straight and horizontal tubes. Figure 4 Show Figure 3 Schematic diagram of the AA section; Figure 5 This diagram illustrates the use of the fixing device between the vertical tubes inside a nuclear power steam generator when there is a deviation in the gap between the horizontal and vertical tubes. Figure 6 A schematic diagram of the support bracket structure for the fixing device between vertical tubes inside a nuclear power steam generator is shown. Figure 7 A schematic diagram of the universal joint structure of the fixing device between vertical tubes inside a nuclear power steam generator is shown. Figure 8 A schematic diagram of the hinge structure of the fixing device between vertical tubes inside a nuclear power steam generator is shown. Figure 9 This diagram shows the temporary fixing position of the separator during the welding of the steam generator shell weld. Figure 10 This diagram shows the reset installation of the steam generator separator. Figure 11 A schematic diagram showing the installation of the separator and feedwater ring on the upper part of the steam generator is shown. Figure 12 A schematic diagram showing the installation of the fixing device between the vertical tubes inside a nuclear power plant steam generator; Figure 13 Show Figure 12 Diagram of direction A in the middle.

[0023] Figure Labels 1-Supporting Card Holder 11-Universal block connection groove 12-Connecting hole 13-Screw connecting groove 14-Large Curved Surface 2-Universal Block 21-Single Board End 22-Double-plate end 3-Hinge 31-Small curved surface 32-Hinged end 4-Connecting Shaft 5-Screw 6-Connecting Nut 71-Horizontal Tube 72-Straight Pipe 81-Upper shell 82-Inner Sleeve 83-Lower shell 84-Dryer 85-Wedge 86-Separator 87-Water Supply Ring 88-Shell weld 89-Heat exchanger tube 90-Internal component weld 91-Manhole R-support bracket and straight tube installation arc α - Oscillating angle of the gimbal L1 - Small gap between straight and horizontal tubes L2 - Large gap between straight and horizontal tubes Detailed Implementation 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 apparent.

[0024] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0025] According to the present invention, a fixing device between vertical tubes inside a nuclear power steam generator is provided, such as... Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the device includes a support bracket 1, a universal block 2, and a hinge 3; One side of the support bracket 1 is a large arc surface 14, and the other side is hinged to the universal block 2. The support bracket 1 abuts against the straight tube 72 through the large arc surface 14. The universal block 2 is hinged to the support bracket 1 on one side and to the hinge bracket 3 on the other side, and the rotation directions of the two hinges are perpendicular to each other. The hinge seat 3 is hinged to the universal block 2 on one side, and two small arc surfaces 31 are provided on the other side. The hinge seat 3 abuts against the horizontal tube 71 through the small arc surfaces 31.

[0026] Preferably, two universal blocks 2 are hinged to the support bracket 1, and a hinge seat 3 is hinged to each universal block 2. That is, two hinge seats 3 are connected to one support bracket 1. The two hinge seats 3 can deflect appropriately to adapt to the curvature of the horizontal tube 71 and to press the horizontal tube 71 tightly. Since the horizontal tube 71 is relatively long and there are many straight tubes 72, it is necessary to limit and support the horizontal tube 71 at different positions with different straight tubes 72. Accordingly, the outer diameter of the horizontal tube 71 and its distance from the straight tube 72 may be different at different positions. The two hinge seats 3 can deflect relative to each other to ensure that the support is firm and reliable and to prevent scratching of the tubes.

[0027] Preferably, the device further includes a screw 5 and a connecting nut 6; the screw 5 and connecting nut 6 connect two support brackets 1, and the distance between the two support brackets 1 can be adjusted according to the outer diameter of the horizontal tube 71. In this application, the theoretical gap between the horizontal tube 71 of the water supply ring 87 and the straight tubes 72 of the separators 86 on both sides is 30mm. Due to the influence of the manufacturing precision of the parts and the installation tolerance, there is an uneven gap on both sides, such as... Figure 5 As shown, the small gap L1 on one side is about 20~30mm, and the large gap L2 on one side is about 30~40mm. In this application, by setting the above-mentioned screw 5 and connecting nut 6, the two support brackets 1 are pulled synchronously to bring them closer to each other, which can ensure that the hinge 3 on the support bracket 1 is in full contact with the horizontal tube 71, and eliminate problems such as insufficient contact and insufficient support strength caused by inconsistent gaps on both sides of the horizontal tube 71.

[0028] Preferably, such as Figure 6 As shown, on the support base 1, a recessed universal block connecting groove 11 is provided on the side opposite to the large arc surface 14, and one end of the universal block 2 can extend into the universal block connecting groove 11. The support bracket 1 is also provided with two connecting holes 12 that pass through the universal block connecting groove 11 vertically. The connecting shaft 4 for hinged connection can be inserted into the connecting hole 12. In this application, the connecting shaft 4 used for hinged support bracket 1 and universal block 2 and the connecting shaft 4 used for hinged universal block 2 and hinge bracket 3 can be selected as the same specification connecting shaft, so as to reduce the complexity of on-site assembly of the fixing device.

[0029] The end of the support bracket 1 is also provided with an inwardly recessed screw connection groove 13; the screw 5 can be embedded in the screw connection groove 13, and the support bracket 1 can be pushed to translate along the length direction of the screw 5 by pre-tightening the connecting nut 6.

[0030] Preferably, when two universal blocks 2 are hingedly connected in the universal block connecting groove 11, the maximum allowable angle for the universal block 2 to swing away from the other universal block 2 from a state perpendicular to the support bracket 1 is α, and the value of α is 10 to 20 degrees, preferably 15 degrees. The purpose of setting this angle α in this application is to ensure that the universal block 2 can rotate within the support bracket 1 to meet the fixing requirements of horizontal tubes of different shapes.

[0031] Preferably, the radius of the large arc surface 14 is smaller than the radius of the straight tube 72. More preferably, the radius of the arc surface is 3-5 degrees smaller than the radius of the straight tube 72. This curvature setting allows the two ends of the large arc surface to contact the straight tube 72, making it more stable.

[0032] Preferably, such as Figure 7 As shown, the universal block 2 includes a single plate end 21 extending into the universal block connection groove 11 and a double plate end 22 located outside the universal block connection groove 11; The double-plate end 22 includes two parallel clamping plates, and the distance between the clamping plates allows the hinge end of the hinge seat 3 to extend in. Both the single-plate end 21 and the double-plate end 22 have through holes for the connecting shaft 4 to pass through. The single-plate end 21 and the double-plate end 22 are arranged perpendicularly to each other.

[0033] Preferably, such as Figure 8 As shown in the figure, a hinge end 32 is provided on one side of the hinge seat 3, and the hinge end 32 is hinged to the universal block 2. The other side of the hinge 3 is a tube support end with two outwardly protruding small arc surfaces 31, and the two small arc surfaces 31 are connected by an inwardly concave arc structure. In this application, the purpose of providing two small arc surfaces 31 is to ensure that each hinge can stably support the horizontal tube without causing indentations; The two support brackets 1 described in this application are used in a group, that is, the large arc surfaces 14 of the two support brackets 1 abut against a straight tube 72; the hinges 3 connected to the two support brackets 1 abut against the two sides of the horizontal tube 71 independently, and the two support brackets 1 are tightened and fixed to each other by screws 5 and connecting nuts 6.

[0034] Preferably, the straight tube 72 is a straight tube on the separator, there are multiple of them, and they are arranged in parallel to each other; The horizontal tube 71 is an annular tube on the water supply ring, arranged horizontally and embedded between multiple straight tubes 72.

[0035] The present invention also provides a method for fixing the internal vertical tubes of a nuclear power steam generator during horizontal rotation.

[0036] The internal components of the upper shell of the steam generator in a CAP1000 pressurized water reactor nuclear power plant, such as... Figure 11The diagram shows a vertical installation. Due to structural limitations of the equipment, the separator needs to be pre-positioned 300mm towards the dryer after installation. After the upper and lower components are butt-welded together, the separator is reset and butt-welded to the inner sleeve 82, completing the overall manufacturing of the equipment.

[0037] The separator and feedwater ring are manufactured as a single unit, with the feedwater ring positioned in the middle of the separator's straight tube. During lifting and installation, the feedwater ring is welded to the shell. The separator is then lowered to its installation position and its coaxiality with the shell is adjusted to meet installation requirements. Finally, the separator and feedwater ring are vertically fixed between the tubes to allow for subsequent horizontal rotation of the nuclear power steam generator. This vertical tube fixing is achieved using the aforementioned internal vertical tube fixing device within the nuclear power steam generator.

[0038] Specifically, the steps include the following: Step 1: The operator enters through the manhole 91 on the casing and reaches the water supply ring position, selecting position 6-12, preferably as follows: Figure 12 , 13 The eight installation positions shown include four installation positions located circumferentially inside the feed water ring horizontal tube 71 and four installation positions circumferentially outside the feed water ring horizontal tube 71. The theoretical gap between the feed water ring horizontal tube 71 and the straight tubes 72 of the separators on both sides is 30mm. Due to the influence of the manufacturing precision of the parts and the installation tolerance, the gaps on both sides are uneven. The smaller gap L1 on one side is about 20~30mm, and the larger gap L2 on the other side is about 30~40mm. Step 2: Install a set of fixing devices between the internal vertical tubes of the nuclear power steam generator at each installation location. Each set of fixing devices includes two support brackets 1. Each support bracket 1 is equipped with two universal blocks 2 and two hinges 3. The two support brackets 1 are tightened together by two screws 5 with connecting nuts 6 screwed on both ends. First, a set of fixing devices is placed at the upper end of the gap between the horizontal tube 71 and the straight tube 72, and another set of fixing devices is placed at the lower end, so that the large arc surface of the support bracket 1 is close to the outer wall of the straight tube 72. The angle of the universal block 2 is adjusted so that each hinge 3 fits well with the shape of the water supply ring horizontal tube 71. Secondly, use screw 5 to connect the upper support bracket 1 and the lower support bracket 1 and pre-tighten the connecting nut 6 so that the fixing device supports between the horizontal tube 71 and the straight tube 72. Step 3: Install wedge 85 at the end of the separator to provide radial support to the shell. At this time, the separator, water supply ring and shell are relatively fixed. Lift the upper component and place it horizontally, and then perform rotary welding on the shell.

[0039] Because of the aforementioned fixing device, the separator is coaxial with the housing and rotates synchronously, and the support between the separator and the water supply ring remains stable at all times.

[0040] Finally, after the shell welds are completed, a hydraulic lifting trolley is used to support the lower part of the separator against the inner wall of the shell and remove all fixing devices. The trolley is then used to move the separator to the inner sleeve for butt welding, thus completing the manufacturing of the equipment.

[0041] Before use and dismantling, the position of the separator was tested. The coaxiality offset was 0mm. No movement occurred during rotation. Due to its own weight, the position of the housing was within 3mm, which met the design requirements. This shows that the fixing device and the fixing method are effective and meet expectations.

[0042] The present invention has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present invention based on these embodiments, all of which fall within the scope of protection of the present invention.

Claims

1. A fixing device between vertical tubes inside a nuclear power steam generator, characterized in that, The device includes a support bracket (1), a universal block (2), and a hinge (3); One side of the support bracket (1) is a large arc surface (14), and the other side is hinged to the universal block (2). The support bracket (1) abuts against the straight tube (72) through the large arc surface (14). The universal block (2) is hinged to the support bracket (1) on one side and to the hinge bracket (3) on the other side, and the rotation directions of the two hinges are perpendicular to each other. The hinge seat (3) is hinged to the universal block (2) on one side, and two small arc surfaces (31) are provided on the other side. The hinge seat (3) abuts against the horizontal tube (71) through the small arc surfaces (31).

2. The fixing device between vertical tubes inside a nuclear power steam generator according to claim 1, characterized in that, Two universal blocks (2) are hinged to the support bracket (1), and a hinge seat (3) is hinged to each universal block (2), that is, two hinge seats (3) are connected to one support bracket (1), so as to adapt to the curvature of the horizontal tube (71) and press the horizontal tube (71) against the hinge seat (3).

3. The fixing device between vertical tubes inside a nuclear power steam generator according to claim 1, characterized in that, The device also includes a screw (5) and a connecting nut (6); the screw (5) and the connecting nut (6) connect two support brackets (1), and the distance between the two support brackets (1) can be adjusted according to the outer diameter of the horizontal tube (71).

4. The fixing device between vertical tubes inside a nuclear power steam generator according to claim 1, characterized in that, On the support base (1), a recessed universal block connection groove (11) is provided on the side opposite to the large arc surface (14), and one end of the universal block (2) can be inserted into the universal block connection groove (11); The support bracket (1) is also provided with two connecting holes (12) that pass through the universal block connecting groove (11) vertically. The connecting shaft (4) that is hinged can be inserted into the connecting hole (12). The end of the support bracket (1) is also provided with an inwardly recessed screw connection groove (13); the screw (5) can be embedded in the screw connection groove (13) and can be pushed to translate along the length direction of the screw (5) by pre-tightening the connection nut (6); The radius of the large arc surface (14) is smaller than the radius of the straight tube (72).

5. The fixing device between vertical tubes inside a nuclear power steam generator according to claim 4, characterized in that, When two universal blocks (2) are hinged in the universal block connecting groove (11), the maximum allowable angle for the universal block (2) to swing away from the support bracket (1) towards the other universal block (2) is α, where α is between 10 and 20 degrees.

6. The fixing device between vertical tubes inside a nuclear power steam generator according to claim 1, characterized in that, The universal block (2) includes a single plate end (21) extending into the universal block connection groove (11) and a double plate end (22) located outside the universal block connection groove (11). The double-plate end (22) includes two parallel clamping plates, the distance between which allows the hinge end of the hinge seat (3) to extend in, and through holes for the connecting shaft (4) to pass through are provided on both the single-plate end (21) and the double-plate end (22). The single-plate end (21) and the double-plate end (22) are arranged perpendicularly to each other.

7. The fixing device between vertical tubes inside a nuclear power steam generator according to claim 1, characterized in that, The hinge seat (3) has a hinge end (32) on one side, and is hinged to the universal block (2) through the hinge end (32); The other side of the hinge (3) is a tube support end with two outwardly protruding small arc surfaces (31), and the two small arc surfaces (31) are connected by an inwardly concave arc structure.

8. The fixing device between vertical tubes inside a nuclear power steam generator according to claim 3, characterized in that, The two support brackets (1) are used in a group, that is, the large arc surface (14) of the two support brackets (1) abuts against a straight tube (72); the hinges (3) connected to the two support brackets (1) abut against the two sides of the horizontal tube (71) independently, and the two support brackets (1) are tightened and fixed to each other by screws (5) and connecting nuts (6).

9. The fixing device between vertical tubes inside a nuclear power steam generator according to claim 1, characterized in that, The straight tube (72) is a straight tube on the separator, there are multiple of them, and they are arranged in parallel to each other; The horizontal tube (71) is an annular tube on the water supply ring, arranged horizontally and embedded between multiple straight tubes (72).

10. A method for fixing internal vertical tubes in a horizontally rotating nuclear power steam generator, characterized in that, This method is achieved through the fixing device between the vertical tubes inside the nuclear power steam generator as described in any one of claims 1 to 9.

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