High-efficiency positioning and assembly welding device and welding method for feed water ring spray tank of nuclear power steam generator

Abstract

The present invention discloses a high-efficiency positioning and welding device and method for a feed water ring spray tank of a nuclear power steam generator; the device can perform simple and accurate positioning, and prevent shrinkage and oxidation during the welding process through circulating water cooling and water level sealing; the device supports the spray pipe through a bottom plate, and provides radial limit for the spray pipe through a radial positioning rod; the top cover is supported by an axial distance pipe, and the radial positioning rod provides radial limit for the top cover; the height value of the axial distance pipe is 3 mm larger than the height value of the spray pipe, so that a 3-mm gap is maintained between the spray pipe and the top cover during the welding operation; a cooling water channel is formed by a water inlet pipe, a distance pipe, a water storage cylinder and a drain pipe to cool the weld seam and seal the drain holes of the spray pipe; and then argon gas protection is provided for the weld seam through an argon gas pipe and the axial distance pipe. Based on this, welding operations can meet the welding precision requirements, reduce grinding operations, and thus save operation time.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing nuclear power steam generators, and particularly to a device and method for controlling the assembly accuracy and welding quality of the steam feed water ring spray irrigation of a steam generator. Background Art

[0002] The Hualong One steam generator is the main nuclear island equipment of the third-generation pressurized water reactor nuclear power plant independently designed in China. As an important pressure-bearing component for internal water supply, the water supply ring has high installation accuracy for each weld, and strict requirements for welding quality and weld surface forming. The whole water supply ring is made of stainless steel material, and 24 spray cans for uniform water drainage are installed circumferentially at the upper end. The spray can is assembled and welded by a spray pipe and a top cover. After welding, non-destructive flaw detection inspections are required on both the inner and outer sides of the weld. After passing, it is installed with the water supply ring.

[0003] The weld between the spray pipe and the top cover is a full penetration structure. The inner side forming requires a smooth surface and good metallic luster, and the outer side requires the outer wall to be ground flat after welding, with the misalignment ≤ 1 mm. For welds requiring full penetration, usually the welding gap needs to be adjusted to at least 3 mm before welding to ensure that the welding fluid can penetrate through the gap to form on the inner side. When welding the first layer of the weld bead, an inert gas with a concentration ≥ 99% needs to be filled on the inner side to prevent the weld surface from oxidation. If the local forming of the inner weld is poor or oxidized, the inner weld surface needs to be ground to remove defects and oxides.

[0004] Due to the small size and large quantity of the spray irrigation, the following difficulties exist in actual manufacturing:

[0005] 1. The misalignment requirements between the spray pipe and the top cover are strict. With a 3 mm welding gap ensured, the two parts are in a non-contact state, making it difficult to position and weld.

[0006] 2. The full penetration requirement of the weld usually requires a welding gap of more than 3 mm to ensure the forming of the inner weld. However, during welding, the weld will gradually shrink with heat, and the poor thermal conductivity of the stainless steel material causes obvious shrinkage during welding. As a result, before the entire circumferential weld of the first layer is welded, the gap has shrunk to a state where it cannot be penetrated. Therefore, usually an additional step of fixed connection needs to be added before welding. A connecting block made of the same material is welded between the two parts to assist in positioning and prevent shrinkage. However, the welding of the connecting block also has installation difficulties and shrinkage risks, affecting the installation dimensions. Moreover, non-destructive flaw detection is required on the surface of the welding and removal positions of the connecting block, increasing the cost and operation cycle.

[0007] 3. When welding, the concentration of inert gas inside the weld seam is required to be ≥99% to prevent surface oxidation. However, there are dense hydrophobic holes arranged on the outer wall of the spray pipe. When filling inert gas inside, it is difficult to prevent air from mixing in, and oxides are very likely to be generated on the surface after welding. Since the diameter of the spray pipe is small and the weld position is relatively deep, once oxide scale appears on the surface of the inner weld seam or incomplete penetration occurs due to too small a gap, etc., grinding is required to remove it. In nuclear power manufacturing, strict requirements are imposed on grinding, and it is not allowed to damage the surface of the part body. Only the weld filler metal can be repaired. Therefore, the grinding is very difficult and time-consuming. The number of spray pipes for each steam generator is relatively large, a total of 24 pieces, and the manufacturing cycle reaches 12 days. If there are problems such as unqualified dimensions or weld quality, it will take twice as long for rework or even scrapping.

[0008] In summary, there is an urgent need for an efficient alignment auxiliary device and welding method that can solve the above problems and ensure the welding quality inside and is efficient. Summary of the Invention

[0009] To overcome the above problems, the inventor has conducted intensive research and designed a high-efficiency positioning and group welding device and method for the feed water ring spray tank of a nuclear power steam generator. The device can simply and accurately position, prevent shrinkage and oxidation during welding through circulating water cooling and water level sealing. The device supports the spray pipe through the bottom plate, and provides radial limit for the spray pipe through the radial positioning rod. The top cover is supported by the axial distance tube, and the radial positioning rod provides radial limit for the top cover. The height value of the axial distance tube is 3 mm larger than the height value of the spray pipe, so that a 3-mm gap is maintained between the spray pipe and the top cover during welding. A cooling water channel is formed by the water inlet pipe, the distance tube, the water storage cylinder and the drain pipe to cool the weld seam and seal the hydrophobic holes of the spray pipe. Then, argon gas protection is provided for the weld seam through the argon gas pipe and the axial distance tube. Based on this, welding operations can meet the welding accuracy requirements, reduce grinding operations, and thus save operation time, thereby completing the present invention.

[0010] Specifically, the object of the present invention is to provide a high-efficiency positioning and group welding device for the feed water ring spray tank of a nuclear power steam generator. The spray tank 8 includes a spray pipe 81 and a top cover 82; spray pipe hydrophobic holes 811 are provided on the spray pipe 81.

[0011] The device includes an axial distance tube 1, a radial positioning rod 2, an argon gas pipe 3, a water storage cylinder 4, a bottom plate 5, a water inlet pipe 6 and a drain pipe 7;

[0012] Among them, the spray pipe 81 is supported by the bottom plate 5, and the radial positioning rod 2 provides radial limit for the spray pipe 81;

[0013] The top cover 82 is supported by the axial distance tube 1, and the radial positioning rod 2 provides radial limit for the top cover 82;

[0014] The cooling water channel is composed of the water inlet pipe 6, the fixed-distance pipe 1, the water holding cylinder 4 and the drain pipe 7, which cools the weld seam and seals the hydrophobic holes 811 of the spray pipe.

[0015] Argon protection is provided for the weld seam through the argon pipe 3 and the axial fixed-distance pipe 1.

[0016] Among them, an argon sealing plate 11 is provided on the axial fixed-distance pipe 1, an argon distribution hole 12 is opened above the argon sealing plate 11, and a drain port 13 is opened below the argon sealing plate 11.

[0017] Preferably, a central hole for the argon pipe 3 to pass through is opened in the middle of the argon sealing plate 11.

[0018] More preferably, the argon in the argon pipe 3 enters the space surrounded by the argon sealing plate 11, the axial fixed-distance pipe 1 and the top cover 82 through the central hole, and finally overflows from the argon distribution hole 12, so as to cover the welding area.

[0019] Among them, the axial fixed-distance pipe 1 is arranged inside the water holding cylinder 4, and the spray pipe 81 is located between the axial fixed-distance pipe 1 and the water holding cylinder 4.

[0020] The water inlet pipe 6 is arranged at the edge of the bottom plate 5 and is located between the axial fixed-distance pipe 1 and the water holding cylinder 4; the drain pipe 7 is arranged in the middle of the bottom plate 5 and is located inside the axial fixed-distance pipe 1.

[0021] Preferably, the height of the water holding cylinder 4 is greater than the bottom edge height of the drain port 13 on the axial fixed-distance pipe 1; so that the cooling water entering through the water inlet pipe 6 can enter the inside of the axial fixed-distance pipe 1 from the drain port 13 and finally be discharged from the drain pipe 7.

[0022] The bottom edge height of the drain port 13 on the axial fixed-distance pipe is greater than the top edge height of the uppermost hydrophobic hole 811 of the spray pipe, so as to ensure that the cooling water can seal the hydrophobic hole 811 of the spray pipe and prevent the hydrophobic hole 811 of the spray pipe from breathing.

[0023] Among them, a plurality of radial positioning rods 2 are provided, arranged parallel to each other and all vertically and fixedly installed on the bottom plate 5.

[0024] All the radial positioning rods 2 are located inside the water holding cylinder 4.

[0025] The plurality of radial positioning rods 2 are arranged in a circular distribution.

[0026] The spray pipe 81 is embedded in the circular area surrounded by the plurality of radial positioning rods 2, and the spray pipe 81 abuts against at least two positioning rods at the same time.

[0027] Among them, the inner diameter dimension of the circular area formed by surrounding the multiple radial positioning rods 2 is 1 mm larger than the outer diameter dimensions of the spray pipe 81 and the top cover 82;

[0028] Both the spray pipe 81 and the top cover 82 can move horizontally within this circular area, so that the spray pipe 81 and the top cover 82 can simultaneously abut against the same two radial positioning rods 2, and further, the misalignment amount between the spray pipe 81 and the top cover 82 during the welding operation is 0.

[0029] Among them, the height value of the axial distance pipe 1 is 3 mm larger than the height value of the spray pipe 81; thus, during the welding operation, a 3-mm gap is maintained between the spray pipe 81 and the top cover 82.

[0030] Among them, a plurality of argon distribution holes 12 are provided;

[0031] Preferably, the plurality of argon distribution holes 12 are all at the same horizontal height, and in the horizontal direction, the circumferential distribution angle of the plurality of argon distribution holes 12 is β; in the horizontal direction, the welding area angle for performing the welding operation is α, and preferably, the angle value of α is 90° - 170°;

[0032] Preferably, the circumferential distribution angle β is greater than the welding area angle α.

[0033] Among them, the main body of the radial positioning rod 2 is cylindrical, and the top of the radial positioning rod 2 is a spherical head.

[0034] The present invention also provides a high-efficiency welding method for the feed water ring spray tank of a nuclear power steam generator,

[0035] This method is realized by using the high-efficiency positioning and group welding device for the feed water ring spray tank of the nuclear power steam generator described above;

[0036] Preferably, in this method, the spray pipe 81 is supported by the bottom plate 5, and the radial positioning rod 2 provides a limit for the spray pipe 81 in the radial direction;

[0037] The top cover 82 is supported by the axial distance pipe 1, and the radial positioning rod 2 provides a limit for the top cover 82 in the radial direction;

[0038] A cooling water channel is formed by the water inlet pipe 6, the distance pipe 1, the water storage cylinder 4 and the drain pipe 7 to cool the weld seam and seal the hydrophobic hole 811 of the spray pipe;

[0039] Argon protection is provided for the weld seam through the argon pipe 3 and the axial distance pipe 1.

[0040] Among them, this method includes the following steps:

[0041] Step 1: Place the spray pipe 81 between the axial distance tube 1 and the radial positioning rod 2, with its lower end in contact with the bottom plate 5. Then, place the top cover 82 between the radial positioning rods 2 and in contact with the top end of the axial distance tube 1. Push both the spray pipe 81 and the top cover 82 to the side opposite to the welding area and ensure that they are in contact with at least two radial positioning rods 2. At this time, the misalignment between the spray pipe 81 and the top cover 82 is 0 mm, and the gap is 3 mm.

[0042] Step 2: Inject cooling water into the water storage cylinder 4 along the water inlet pipe 6. The temperature of the cooling water should be close to room temperature.

[0043] Step 3: Input pure argon into the argon gas pipe 3 for about 30 seconds, and then start the welding operation within the angle α range of the welding area.

[0044] Preferably, in Step 3, during the welding process, manually adjust the circumferential position of the sprinkler 8 to the welding area. After each adjustment, touch the outer wall of the water storage cylinder 4 to confirm that the water temperature is normal, and then start the welding operation.

[0045] The beneficial effects of the present invention include:

[0046] (1) According to the high-efficiency positioning and assembly welding device and welding method for the feed water ring spray can of the nuclear power steam generator provided by the present invention, the misalignment and gap size accuracy between the spray pipe and the top cover during assembly are high, and the speed is fast, saving multiple steps such as fixing the welding connection block and subsequent removal, grinding, and flaw detection.

[0047] (2) According to the high-efficiency positioning and assembly welding device and welding method for the feed water ring spray can of the nuclear power steam generator provided by the present invention, the inert gas protection effect inside the weld is good. By sealing the hydrophobic holes of the spray pipe with cooling water, air entry into the inner space of the weld is avoided, and the argon concentration inside the first layer of the weld bead is well ensured through the uniform distribution of the argon distribution holes at the upper end of the axial distance tube 1, avoiding oxidation of the weld surface.

[0048] (3) According to the high-efficiency positioning and assembly welding device and welding method for the feed water ring spray can of the nuclear power steam generator provided by the present invention, the defect of poor thermal conductivity of stainless steel materials is solved by using the water cooling method. The rapid cooling of the welding area is ensured by the circulating flow of the cooling water under the weld, and the shrinkage of the welding gap is well controlled, ensuring the penetration of the weld. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A cross-sectional view showing the front view of the device;

[0050] Figure 2 A three-dimensional view showing the device;

[0051] Figure 3 Showing Figure 2 Schematic view in the direction of A in

[0052] Figure 4 Schematic diagram showing each part of the device and related dimensions;

[0053] Figure 5 Schematic diagram showing the structure of the axial spacing tube;

[0054] Figure 6 Schematic diagram showing the structure of the radial positioning rod;

[0055] Figure 7 Schematic diagram showing the structure of the bottom plate;

[0056] Figure 8 Schematic diagram showing the structure of the water supply ring assembly;

[0057] Figure 9 Schematic diagram showing the structure of the sprinkler irrigation;

[0058] Reference numerals

[0059] 1 - Axial spacing tube

[0060] 11 - Argon sealing plate

[0061] 12 - Argon distribution hole

[0062] 13 - Drain outlet

[0063] 131 - Positioning key slot

[0064] 132 - Lower clamping plate set screw thread hole

[0065] 14 - Rib plate

[0066] 2 - Radial positioning rod

[0067] 3 - Argon gas pipe

[0068] 4 - Water holding cylinder

[0069] 5 - Bottom plate

[0070] 51 - Radial positioning rod thread hole

[0071] 52 - Drain pipe hole

[0072] 53 - Argon gas pipe hole

[0073] 54 - Water inlet pipe hole

[0074] 6 - Water inlet pipe

[0075] 7 - Drain pipe

[0076] 8 - Sprinkler irrigation

[0077] 81 - Sprinkler pipe

[0078] 811 - Sprinkler pipe hydrophobic hole

[0079] 82 - Top cover

[0080] 9 - Feed water ring Detailed implementation manners

[0081] 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 more clearly defined.

[0082] The specific term "exemplary" herein means "serving as an example, embodiment, or illustration". Any embodiment described herein as "exemplary" is not necessarily 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.

[0083] According to the high - efficiency positioning and group welding device for the spray tank of the feed water ring of a nuclear power steam generator provided by the present invention, the spray tank 8 includes a spray pipe 81 and a top cover 82; a spray pipe drain hole 811 is provided on the spray pipe 81, as Figure 8 and Figure 9 shown in

[0084] As Figure 1 , Figure 2 , Figure 3 , Figure 4 shown, the device includes an axial spacing tube 1, a radial positioning rod 2, an argon gas pipe 3, a water - holding cylinder 4, a bottom plate 5, a water inlet pipe 6, and a drain pipe 7;

[0085] Among them, the spray pipe 81 is supported by the bottom plate 5, and the radial positioning rod 2 provides a limit for the spray pipe 81 in the radial direction;

[0086] The top cover 82 is supported by the axial spacing tube 1, and the radial positioning rod 2 provides a limit for the top cover 82 in the radial direction;

[0087] A cooling water channel is formed by the water inlet pipe 6, the spacing tube 1, the water - holding cylinder 4, and the drain pipe 7 to cool the weld and seal the spray pipe drain hole 811;

[0088] Argon gas protection is provided for the weld by the argon gas pipe 3 and the axial spacing tube 1.

[0089] In a preferred implementation manner, as Figure 5 shown, the axial spacing tube 1 is a regular stainless - steel tube with a diameter smaller than that of the spray pipe 81, its height C is the height A of the high spray pipe 81 + 3 mm, an argon gas sealing plate 11 is provided on the axial spacing tube 1, an argon gas distribution hole 12 is opened above the argon gas sealing plate 11, and a drain port 13 is opened below the argon gas sealing plate 11; the drain port 13 and the argon gas distribution hole 12 are arranged on the same side.

[0090] Preferably, a central hole for the argon pipe 3 to pass through is provided in the middle of the argon gas sealing plate 11; the argon pipe 3 is a stainless steel straight pipe, one end of which is connected to an argon gas hose, and the other end can pass through the bottom plate 5 and extend into the central hole of the axial distance tube argon gas sealing plate 11;

[0091] More preferably, the argon pipe 3 is inserted along the argon pipe hole 53 of the bottom plate and passes through the axial distance tube and the argon gas sealing plate 11. The argon gas in the argon pipe 3 enters the space surrounded by the argon gas sealing plate 11, the axial distance tube 1 and the top cover 82, that is, a relatively sealed chamber, and finally overflows from the argon gas distribution hole 12, so as to cover the welding area. Further, the argon gas is 100% concentrated argon gas, which can exhaust the air in the chamber between the argon gas sealing plate 11 and the top cover 82 and evenly blow pure argon gas along the argon gas distribution hole 12 to the back side of the weld between the spray pipe 81 and the top cover 82 for anti-oxidation protection.

[0092] In a preferred embodiment, the axial distance tube 1 is arranged inside the water storage cylinder 4, and the spray pipe 81 is located between the axial distance tube 1 and the water storage cylinder 4; the bottoms of the axial distance tube 1, the water storage cylinder 4 and the spray pipe 81 all abut against the bottom plate 5;

[0093] The water inlet pipe 6 is arranged at the edge of the bottom plate 5 and is located between the axial distance tube 1 and the water storage cylinder 4; the drain pipe 7 is arranged in the middle of the bottom plate 5 and is located inside the axial distance tube 1;

[0094] Preferably, the height E of the water storage cylinder 4 is greater than the bottom edge height D of the drain opening 13 on the axial distance tube 1; so that the cooling water entering through the water inlet pipe 6 can enter the inside of the axial distance tube 1 from the drain opening 13 and finally be discharged from the drain pipe 7, without affecting the welding area;

[0095] The bottom edge height D of the drain opening 13 on the axial distance tube is greater than the top edge height B of the uppermost spray pipe drain hole 811, so as to ensure that the cooling water can seal the spray pipe drain hole 811 and prevent the spray pipe drain hole 811 from breathing.

[0096] Preferably, the water storage cylinder 4 is a cylinder sleeved outside the radial positioning rod 2 and hermetically connected to the bottom plate 5 in the circumferential direction. The height E of the water storage cylinder is higher than the drain opening D of the axial distance tube and lower than the height A of the spray pipe, aiming to ensure a reasonable welding vision and operation space on the premise of satisfying that the water level in the cylinder seals all the spray pipe drain holes 811.

[0097] In a preferred embodiment, as Figure 6As shown in the figure, the radial positioning rod 2 is a stainless steel round rod with a length higher than that of the spray can. The main body of the radial positioning rod 2 is cylindrical, and the top of the radial positioning rod 2 is a spherical head SR. The purpose of setting the spherical head is to guide the spray pipe 81 and the top cover 82 when they are assembled into the device, shorten the assembly time, improve the efficiency, and reduce the error rate. The purpose of selecting a round rod is to reduce the contact area with the spray pipe 81 and avoid jamming. At the lower end of the radial positioning rod 2, there is a thread for connecting with the bottom plate to fix and install on the bottom plate 5.

[0098] A plurality of the radial positioning rods 2 are provided and arranged in parallel with each other, and are all vertically and fixedly installed on the bottom plate 5;

[0099] All the radial positioning rods 2 are located inside the water storage cylinder 4,

[0100] The plurality of radial positioning rods 2 are arranged in a circular distribution;

[0101] The spray pipe 81 is embedded in the circular area surrounded by the plurality of radial positioning rods 2, and the spray pipe 81 abuts against at least two positioning rods at the same time. Among them, the radial positioning rods 2 are not evenly distributed, and no radial positioning rods are provided at the positions corresponding to the welding areas to prevent interference with the welding operation.

[0102] Further preferably, the inner diameter of the circular area surrounded by the plurality of radial positioning rods 2 is 1 mm larger than the outer diameters of the spray pipe 81 and the top cover 82; to leave a certain margin for installation.

[0103] Both the spray pipe 81 and the top cover 82 can move horizontally in the circular area, so that the spray pipe 81 and the top cover 82 can simultaneously abut against the same two radial positioning rods 2, and further, the misalignment amount between the spray pipe 81 and the top cover 82 during the welding operation is 0;

[0104] The height value of the axial distance tube 1 is 3 mm larger than the height value of the spray pipe 81; so that during the welding operation, a 3-mm gap is maintained between the spray pipe 81 and the top cover 82.

[0105] In a preferred embodiment, as Figure 7 shown in the figure, the bottom plate 5 is a circular stainless steel plate, and an argon gas pipe hole 53, a water inlet pipe hole 54 and a drain pipe hole 52 are provided at the central position, and a plurality of radial positioning rod connection screw holes 51 are provided circumferentially at the upper end; when the axial distance tube 1 is installed on the bottom plate 5, the drain pipe hole 52 and the argon gas pipe hole 53 are located inside the radial positioning tube 1, and the argon gas distribution holes 12 and the drain ports 13 both face the side of the welding area at an angle α.

[0106] In a preferred embodiment, a plurality of the argon gas distribution holes 12 are provided;

[0107] Preferably, multiple argon distribution holes 12 are all located at the same horizontal height, and in the horizontal direction, the circumferential distribution angle of the multiple argon distribution holes 12 is β; in the horizontal direction, the welding area angle where welding operations can be performed is α. Preferably, the angle value of α is 90° - 170°, preferably 120°; this welding area angle is determined by the setting position of the radial positioning rod 2. Outside the welding area angle α, 3 - 5 radial positioning rods 2 are evenly distributed circumferentially, preferably 5, aiming to ensure that when the spray pipe 81 and the top cover 82 are placed into this device, they are at least in contact with 2 radial positioning rods 2, thereby better ensuring that the misalignment amount of the entire circle is 0 mm.

[0108] Preferably, the circumferential distribution angle β is greater than the welding area angle α, aiming to ensure that argon can directly blow the back side of the weld during welding and prevent oxygen from mixing in.

[0109] When the spray pipe and the top cover are successively placed into the high - efficiency positioning and group welding device for the feed water ring spray tank of a nuclear power steam generator, that is, when the spray pipe 81 and the top cover 82 are successively placed between the axial distance - determining pipe 1 and the radial positioning rod 2, and they are leaned against at least two radial positioning rods 2 to be in contact with them, at this time, the misalignment between the spray pipe 81 and the top cover 82 approaches 0 mm; the lower end of the spray pipe 81 is in contact with the bottom plate 5, and the top cover 82 is in contact with the axial distance - determining pipe 1, naturally forming a 3 - mm welding gap, meeting the dimensional requirements and welding requirements.

[0110] Cooling water is injected from the water inlet pipe 6 and flows into the drain pipe 7 through the drain opening 13 of the axial distance - determining pipe. By adjusting the flow rate of the valve of the water inlet pipe 6, a circulating water with a stable flow rate is ensured to be formed inside the water - holding cylinder 4. At this time, the cooling water seals all the spray pipe drain holes 811, improves the inert gas concentration on the back side of the weld to ensure that the weld surface is not oxidized, and during welding, the circulating cooling water can absorb the heat around the weld, effectively suppressing the problem that the welding gap is reduced due to thermal shrinkage and resulting in incomplete penetration.

[0111] The weld between the spray pipe 81 and the top cover 82 is welded within the welding area angle α. After each section is welded, the sprinkler can be manually rotated to adjust the circumferential position until the entire circle is welded. During the welding process, the lower end of the weld of the spray pipe 81 is always immersed in the circulating cooling water for cooling. The drain opening of the axial distance - determining pipe is located directly below the welding area, ensuring that the temperature around the weld will not shrink due to excessive heat and cause the gap to become smaller. This device is ingeniously designed, fully functional, and convenient to use, greatly improving the quality and efficiency of sprinkler assembly and welding, improving the alignment accuracy and manufacturing efficiency of the spray pipe and the top cover. The post - welding dimensions and the weld surface formation are good, without oxidation phenomenon.

[0112] The present invention also provides a high - efficiency welding method for the feed water ring spray tank of a nuclear power steam generator, which is realized by using the above - mentioned high - efficiency positioning and group welding device for the feed water ring spray tank of a nuclear power steam generator;

[0113] Preferably, in this method, the spray pipe 81 is supported by the bottom plate 5, and the radial positioning rod 2 provides radial limit for the spray pipe 81;

[0114] The top cover 82 is supported by the axial spacing pipe 1, and the radial positioning rod 2 provides radial limit for the top cover 82;

[0115] The cooling water channel is composed of the water inlet pipe 6, the spacing pipe 1, the water storage cylinder 4 and the drain pipe 7 to cool the weld and seal the hydrophobic holes 811 of the spray pipe;

[0116] Argon protection is provided for the weld through the argon pipe 3 and the axial spacing pipe 1.

[0117] In a preferred embodiment, the feed water ring spray tank of the Hualong One steam generator is welded by the spray pipe 81 and the top cover 82. The height A of the spray pipe 81 is 170 mm, and the radius R is 51 mm; there are 24 pieces in each set. The weld between the spray pipe 81 and the top cover 82 requires full penetration welding, and the welding gap is required to be at least 3 mm. Inert gas protection is required inside during the first layer of welding, and then the filling of 3 - 4 circles of welds is completed for welding; after welding, the inside is required to be smooth and free of oxides, the outside is required to be smooth after grinding the weld, the misalignment amount ≤ 1 mm, and both sides of the weld must meet the requirements of penetrant flaw detection.

[0118] The method for welding the feed water ring spray tank includes the following steps:

[0119] Step 1, assemble the high - efficiency positioning and group welding device for the feed water ring spray tank of the nuclear power steam generator and conduct dimensional inspection to ensure that the height after the axial spacing pipe 1 and the bottom plate 5 are installed is 170 + 3 mm, and the distance from the inner side of the radial positioning rod 2 to the center of the bottom plate 5 is 51 + 0.5 mm;

[0120] Step 2, place the spray pipe 81 between the axial spacing pipe 1 and the radial positioning rod 2, with the lower end fitting with the bottom plate 5. Then place the top cover 82 between the radial positioning rods 2 and fit with the top end of the axial spacing pipe 1. Push both the spray pipe 81 and the top cover 82 to the side opposite to the welding area and ensure that they both fit with at least two radial positioning rods 2. At this time, the misalignment between the spray pipe 81 and the top cover 82 is 0 mm, and the gap is 3 mm;

[0121] Step 3, inject cooling water into the water storage cylinder 4 along the water inlet pipe 6. The temperature of the cooling water can be close to room temperature; when the water level reaches the height D of the drain port of the axial spacing pipe, the cooling water will be discharged from the drain pipe 7 to form circulating water, and at this time all the hydrophobic holes 811 of the spray pipe are sealed by the cooling water;

[0122] Step 3, input pure argon into the argon pipe 3 for about 30 seconds and then start welding to ensure that the oxygen inside is exhausted; conduct welding operations within the angle α range of the welding area; ensure that the weld is in the same direction as the argon distribution holes 12 on the axial spacing pipe, and adjust the height of the welding torch and the welding vision well.

[0123] Preferably, in step 3, since the top cover 82 has no axial fixation, before welding, it can be pressed on the upper end of the top cover 82 by hand or weights to prevent it from moving when touched by the welding torch. Before welding, 3 to 4 spot welds are evenly distributed circumferentially to fix the root weld of the spray pipe 81 and the top cover 82, and then the full-circle penetration welding of the root pass is started.

[0124] Preferably, in step 3, during the welding process, manually adjust the circumferential position of the sprinkler 8 to the welding area. After each adjustment, touch the outer wall of the water-filled cylinder 4 to confirm that the water temperature is normal before starting the welding operation.

[0125] Preferably, in step 3, after the first layer of weld is completed, the spray can be taken out from the high-efficiency positioning and group welding device for the feed water ring spray can of the nuclear power steam generator to observe the forming condition of the inner weld and the outer misalignment. If the forming is good and there is no oxide on the surface, the outer groove can be continued to be filled to complete the welding.

[0126] By using the high-efficiency positioning and group welding device and method for the feed water ring spray can of the nuclear power steam generator provided in this application, the assembly and the first layer welding of the spray pipe 81 and the top cover 82 only take about 5 - 8 minutes. The manufacturing of each spray can only takes about 30 minutes. The 24 spray cans only take 3 days from welding, grinding to passing the flaw detection. After welding, the inner weld is well formed, the outer misalignment is 0 - 0.3 mm, and the qualified rate of non-destructive testing is 100%.

[0127] The present invention has been described in combination with preferred embodiments above, but these embodiments are only exemplary and only serve an illustrative purpose. On this basis, various substitutions and improvements can be made to the present invention, and these all fall within the protection scope of the present invention.

Claims

1. An efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator, characterized in that The spray can (8) includes a spray pipe (81) and a top cover (82); a spray pipe drain hole (811) is formed on the spray pipe (81); The device includes an axial spacing pipe (1), a radial positioning rod (2), an argon gas pipe (3), a water holding cylinder (4), a bottom plate (5), a water inlet pipe (6) and a drain pipe (7); Wherein, the spray pipe (81) is supported by the bottom plate (5), and the radial positioning rod (2) provides a limit for the spray pipe (81) in the radial direction; The top cover (82) is supported by the axial spacing pipe (1), and the radial positioning rod (2) provides a limit for the top cover (82) in the radial direction; A cooling water channel is formed by the water inlet pipe (6), the axial spacing pipe (1), the water holding cylinder (4) and the drain pipe (7) to cool the weld and seal the spray pipe drain hole (811); Argon gas protection is provided for the weld by the argon gas pipe (3) and the axial spacing pipe (1); An argon gas sealing plate (11) is arranged on the axial spacing pipe (1), an argon gas distribution hole (12) is formed above the argon gas sealing plate (11), and a drain port (13) is formed below the argon gas sealing plate (11); A central hole for the argon gas pipe (3) to pass through is formed in the middle of the argon gas sealing plate (11).

2. The efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 1, characterized in that The argon gas in the argon gas pipe (3) enters the space surrounded by the argon gas sealing plate (11), the axial spacing pipe (1) and the top cover (82) after passing through the central hole, and finally overflows from the argon gas distribution hole (12) to cover the welding area.

3. The efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 2, characterized in that The axial spacing pipe (1) is arranged inside the water holding cylinder (4), and the spray pipe (81) is located between the axial spacing pipe (1) and the water holding cylinder (4); The water inlet pipe (6) is arranged at the edge of the bottom plate (5) and is located between the axial spacing pipe (1) and the water holding cylinder (4); the drain pipe (7) is arranged in the middle of the bottom plate (5) and is located inside the axial spacing pipe (1).

4. The efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 3, characterized in that The height of the water holding cylinder (4) is greater than the bottom edge height of the drain port (13) on the axial spacing pipe (1); so that the cooling water entering through the water inlet pipe (6) can enter the inside of the axial spacing pipe (1) from the drain port (13) and finally be discharged from the drain pipe (7); The bottom edge height of the drain port (13) on the axial spacing pipe (1) is greater than the top edge height of the uppermost spray pipe drain hole (811), so as to ensure that the cooling water can seal the spray pipe drain hole (811) and prevent the spray pipe drain hole (811) from breathing.

5. The efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 1, characterized in that A plurality of the radial positioning rods (2) are provided and are arranged parallel to each other and are all vertically and fixedly installed on the bottom plate (5); All the radial positioning rods (2) are located inside the water holding cylinder (4), The plurality of radial positioning rods (2) are arranged in a circular distribution; The spray pipe (81) is embedded in the circular area surrounded by the plurality of radial positioning rods (2), and the spray pipe (81) abuts against at least two radial positioning rods (2) at the same time.

6. The efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 5, characterized in that The inner diameter dimension of the circular area surrounded by the plurality of radial positioning rods (2) is 1 mm larger than the outer diameter dimensions of the spray pipe (81) and the top cover (82); Both the spray pipe (81) and the top cover (82) can move horizontally within this circular area, so that the spray pipe (81) and the top cover (82) can simultaneously abut against the same two radial positioning rods (2), and thus the misalignment amount between the spray pipe (81) and the top cover (82) during the welding operation is 0.

7. The efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 1, characterized in that The height value of the axial spacing pipe (1) is 3 mm greater than the height value of the spray pipe (81); so that during the welding operation, a 3-mm gap is maintained between the spray pipe (81) and the top cover (82).

8. The efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 1, characterized in that A plurality of argon distribution holes (12) are provided.

9. The efficient positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 8, characterized in that The plurality of argon distribution holes (12) are all at the same horizontal height, and in the horizontal direction, the circumferential distribution angle of the plurality of argon distribution holes (12) is β; in the horizontal direction, the welding area angle for performing the welding operation is α, and the angle value of α is 90° to 170°.

10. The high-efficiency positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 9, characterized in that The circumferential distribution angle β is greater than the welding area angle α.

11. The high-efficiency positioning and assembly welding device for the feed water ring spray tank of a nuclear power steam generator according to claim 1, characterized in that The main body of the radial positioning rod (2) is cylindrical, and the top of the radial positioning rod (2) is a spherical head.

12. A high-efficiency welding method for the feed water ring spray tank of a nuclear power steam generator, characterized in that This method is realized by using the high-efficiency positioning and assembly welding device for the feed water ring spray tank of the nuclear power steam generator described in any one of claims 1-11; In this method, the spray pipe (81) is supported by the bottom plate (5), and the radial positioning rod (2) provides a limit for the spray pipe (81) in the radial direction; The top cover (82) is supported by the axial spacing pipe (1), and the radial positioning rod (2) provides a limit for the top cover (82) in the radial direction; A cooling water channel is formed by the water inlet pipe (6), the axial spacing pipe (1), the water holding cylinder (4) and the drain pipe (7) to cool the weld and seal the spray pipe drain hole (811); Argon protection is provided for the weld through the argon pipe (3) and the axial spacing pipe (1).

13. The high-efficiency welding method for the feed water ring spray tank of a nuclear power steam generator according to claim 12, characterized in that This method includes the following steps: Step 1: Place the spray pipe (81) between the axial spacing pipe (1) and the radial positioning rod (2), with the lower end in contact with the bottom plate (5). Then place the top cover (82) between the radial positioning rods (2) and in contact with the top end of the axial spacing pipe (1). Push both the spray pipe (81) and the top cover (82) to the side opposite to the welding area and ensure that they are both in contact with at least two radial positioning rods (2). At this time, the misalignment between the spray pipe (81) and the top cover (82) is 0 mm, and the gap is 3 mm; Step 2: Inject cooling water into the water holding cylinder (4) along the water inlet pipe (6). The temperature of the cooling water is close to room temperature. Step 3: Input pure argon into the argon pipe (3) for 30 seconds and then start the welding operation within the range of the welding area angle α.

14. The high-efficiency welding method for the feed water ring spray tank of a nuclear power steam generator according to claim 13, characterized in that In Step 3, during the welding process, manually adjust the circumferential position of the spray can (8) to the welding area. After each adjustment, touch the outer wall of the water holding cylinder (4) to confirm that the water temperature is normal and then start the welding operation.

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