Method for installing and welding a containment vessel penetration of a nuclear power plant

Abstract

This invention relates to the field of nuclear power plant technology, and more particularly to a method for installing and welding a penetration component of a nuclear power plant containment structure. The method includes: setting a plumb bob box and a spirit level on the end face of the penetration component, with the plumb bob positioned radially in the vertical direction and the spirit level positioned radially in the horizontal direction; the intersection of the spirit level and the plumb bob is the center point of the end face of the penetration component, and the two center points on the two end faces of the penetration component are marked; measuring the two center points with a total station to obtain the central axis of the penetration component and the position of the center point; comparing the central axis of the penetration component with the central axis of the mounting hole on the shell plate, and comparing the position of the center point of the penetration component with the center point of the mounting hole; if they are inconsistent, adjusting the penetration component to ensure a one-to-one correspondence. This invention provides a method for installing and welding a penetration component of a nuclear power plant containment structure to reduce the deviation of the penetration component's position relative to the shell plate after welding.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant technology, and in particular to a method for installing and welding penetrations in the containment structure of a nuclear power plant. Background Technology

[0002] The containment vessel of a nuclear power plant is the last line of defense against the leakage of radioactive materials. The containment vessel consists of a cylindrical plate and penetrations welded to the cylindrical plate. The welding quality of the penetrations is crucial and affects the long-term safe operation of the nuclear power plant.

[0003] In existing technologies, the welding process for penetration components generally includes: opening mounting holes in the cylindrical plate for installing the penetration component, then hoisting the penetration component into the mounting holes and assembling it, and then welding the welded joints between the penetration component and the cylindrical plate. However, after the penetration component is welded to the cylindrical plate, there is a deviation in the position of the penetration component relative to the cylindrical plate, which affects the safety and structural integrity of the containment.

[0004] Therefore, this application provides a new method for installing and welding penetrations in the containment structure of a nuclear power plant to address the above-mentioned problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for installing and welding penetrations in the containment structure of a nuclear power plant, so as to reduce the deviation of the penetration relative to the containment plate after the penetration is welded to the containment plate.

[0006] To achieve the above objectives, the present invention provides a method for installing and welding a penetration component of a nuclear power plant containment structure, the method comprising:

[0007] S100, the drilling step, to create mounting holes in the cylindrical plate for mounting through parts;

[0008] S200, the hoisting and assembly steps of the penetrating component; step S200 includes: S210, hoisting the penetrating component into the mounting hole and assembling it; S220, checking and adjusting the orientation of the penetrating component;

[0009] S300, Welding step, welding is performed on the welding parts between the through-piece and the cylindrical plate;

[0010] Step S220 includes:

[0011] A plumb bob box is provided at the top of the end face of the through member, so that the plumb bob in the plumb bob box hangs down, thereby making the plumb bob radially arranged in the vertical direction on the end face of the through member; a spirit level is provided on the end face of the through member, and the spirit level is radially arranged in the horizontal direction on the end face of the through member.

[0012] The intersection of the level and the plumb line is the center point of the end face of the through piece, and the two center points of the two end faces of the through piece are marked as the first center point and the second center point, respectively. The first center point and the second center point are measured with a total station, and the central axis of the through piece is measured through the line connecting the first center point and the second center point. The position of the center point of the through piece is measured through the midpoint of the line connecting the first center point and the second center point.

[0013] The orientation of the through-hole is checked by comparing its central axis with the central axis of the mounting hole on the cylindrical plate, and by comparing its center point with the center point of the mounting hole on the cylindrical plate.

[0014] If the central axis of the through member is not aligned with the central axis of the mounting hole on the cylindrical plate, adjust the through member so that its central axis aligns with the central axis of the mounting hole on the cylindrical plate; if the center point of the through member is not aligned with the center point of the mounting hole on the cylindrical plate, adjust the through member so that its center point aligns with the center point of the mounting hole on the cylindrical plate.

[0015] Further, step S210 includes: S211, hoisting the through piece without the insert plate into the mounting hole and assembling it; and S212, hoisting the through piece with the insert plate into the mounting hole and assembling it.

[0016] Step S211 includes: before hoisting the penetrating component, distinguishing the inner and outer sides of the penetrating component, determining the insertion position of the penetrating component along the axial direction, and drawing a position marking line on the penetrating component accordingly; hoisting the penetrating component to the position of the mounting hole on the cylindrical plate according to the position marking line, and inserting it into the mounting hole; then welding clamps on both the cylindrical plate and the penetrating component, and adjusting the weld gap and misalignment between the penetrating component and the cylindrical plate using the clamps on the cylindrical plate and the penetrating component;

[0017] Step S212 includes: integrating the insertion plate and the through-piece into a through-piece assembly; before hoisting the through-piece assembly, distinguishing the inner and outer sides of the through-piece assembly and determining the axial insertion position of the through-piece assembly, and drawing a position marking line on the through-piece assembly accordingly; hoisting the through-piece assembly to the position of the mounting hole on the cylinder plate according to the position marking line, and inserting it into the mounting hole; then welding clamps on both the cylinder plate and the through-piece, and adjusting the weld gap and misalignment between the through-piece and the cylinder plate using the clamps on the cylinder plate and the through-piece.

[0018] Further, in step S300, the portion between the through-piece assembly and the cylindrical plate, or the portion between the through-piece and the cylindrical plate, is the portion to be welded. Step S300 includes: S310, preheating the welding portion using an auxiliary heating device; S320, performing tack welding on the welding portion; and S330, welding the welding portion.

[0019] In step S310, the auxiliary heating device includes a thermometer, a temperature controller, and a heating element. The thermometer is used to monitor the temperature of the welding area, and the heating element is used to heat the welding area. Both the thermometer and the heating element are connected to the temperature controller.

[0020] The temperature controller can preset a preheating temperature range and a preheating time. The preheating temperature range includes an upper temperature limit and a lower temperature limit. When the heating element is powered on, it can raise the temperature of the welding area until the temperature of the welding area reaches the upper temperature limit. At this time, the heating element is powered off. When the temperature of the welding area reaches the lower temperature limit, the heating element is powered on and activated, and the temperature of the welding area is raised accordingly.

[0021] Furthermore, the auxiliary heating device also includes a clamping mechanism, which includes an annular frame. The annular frame has a clamping cavity that matches the through member. On the side of the annular frame away from the clamping cavity, there are multiple receiving cavities for accommodating the heating element. The multiple receiving cavities are evenly distributed along the circumference of the annular frame, and the heating element is clamped in the receiving cavity.

[0022] Furthermore, the annular frame has multiple ear flaps on the side away from the clamping cavity, and the multiple ear flaps are evenly distributed along the circumference of the annular frame, forming the receiving cavity between adjacent ear flaps.

[0023] Furthermore, the auxiliary heating device also includes a reinforcing mechanism for fastening the heating element to the surface of the cylindrical plate;

[0024] The reinforcement mechanism includes a flexible component and a fixing pin. One end of the flexible component is fixedly connected to the annular frame, and the other end is fixedly connected to the fixing pin.

[0025] The ear flap is provided with a locking hole, and the fixing pin can be inserted into the locking hole. After the fixing pin is inserted into the locking hole, the two ends of the fixing pin are respectively located on both sides of the locking hole, and can respectively abut against the two heating elements on both sides of the locking hole, so that the heating elements are locked between the fixing pin and the cylindrical plate, thereby the heating elements are fastened to the surface of the cylindrical plate.

[0026] Furthermore, the annular frame includes multiple sub-frames, which are sequentially connected end to end to form the clamping cavity. Adjacent sub-frames are connected by a connecting component, and the connecting component can adjust the gap between adjacent sub-frames.

[0027] Furthermore, the adjacent sub-frames are respectively the first sub-frame and the second sub-frame;

[0028] The connecting assembly includes a threaded connector, a nut, a first connecting bracket disposed on the first sub-frame, and a second connecting bracket disposed on the second sub-frame. Both the first connecting bracket and the second connecting bracket are provided with connecting holes. The threaded connector can pass through the connecting holes on the first connecting bracket and the second connecting bracket and then be tightened by the nut.

[0029] Further, step S100 includes: S110, measuring and laying out lines to locate the opening position on the cylinder plate; S120, cutting the opening at the location and processing the cutting bevel; S130, inspecting the cutting bevel and detecting liquid penetration.

[0030] Step S110 includes: using a measuring tool to determine the angle line and elevation line where the center of the opening is located, the intersection of the angle line and the elevation line is the center point of the opening on the cylindrical plate; using the center point as a reference, using a drawing tool to draw the opening cutting line on the cylindrical plate.

[0031] Step S120 includes: using a cutting device to cut along the opening cutting line to form a mounting hole for installing the through part; after cutting, processing the cutting bevel;

[0032] Step S130 includes: after the beveling process is completed, beveling inspection and liquid penetration detection are performed.

[0033] Furthermore, after step S300, the installation and welding method for the nuclear power plant containment penetration component further includes, in sequence:

[0034] S400, Post-weld non-destructive testing steps: After the through-hole component or the through-hole component assembly is welded, visual inspection, liquid penetration testing, radiographic testing and ultrasonic testing are performed.

[0035] S500, Post-heating and post-weld heat treatment steps: After welding is completed, the weld seam of the welded part is subjected to post-heating; wherein, the post-heating temperature range of the weld seam between the through-hole component and the cylindrical plate is 200℃-350℃, and the post-heating time is not less than 30 minutes; the post-heating temperature range of the weld seam between the insert plate and the cylindrical plate is 200℃-350℃, and the post-heating time is not less than 2 hours;

[0036] S600, Non-destructive testing steps after heat treatment.

[0037] By adopting the above technical solution, the installation and welding method for the nuclear power plant containment penetration component of the present invention has at least the following beneficial effects:

[0038] The welding method of this embodiment firstly involves opening an installation hole in the cylinder plate in step S100, then hoisting the through-piece into the installation hole in step S210 and assembling it, then checking and adjusting the orientation of the through-piece in step S220, and finally welding the welding part between the through-piece and the cylinder plate in step S300, thus completing the welding of the through-piece to the cylinder plate.

[0039] In this process, after the penetrating component is hoisted into the mounting hole and assembled, the orientation of the penetrating component is checked and adjusted in step S220 to ensure that the central axis of the penetrating component is consistent with the central axis of the mounting hole on the cylindrical plate, and that the center point of the penetrating component is consistent with the center point of the mounting hole on the cylindrical plate. This ensures a more accurate relative position between the penetrating component and the mounting hole on the cylindrical plate, reduces the deviation of the penetrating component relative to the cylindrical plate after welding it to the cylindrical plate, and improves the safety and structural integrity of the containment.

[0040] It should be noted that in step S220, the vertical diameter direction on the end face of the penetrating component is determined by a plumb bob, and the horizontal radial direction on the end face of the penetrating component is determined by a spirit level. The center point of the end face of the penetrating component is determined by the intersection of the two. Then, the first center point and the second center point are measured by a total station to determine the central axis and center point position of the penetrating component. The above two parameters are then compared one by one with the central axis and center point position of the mounting hole on the cylinder plate to check the orientation of the penetrating component. If the check is not qualified, the orientation of the penetrating component is adjusted so that the central axis and center point position of the penetrating component correspond one by one with the central axis and center point position of the mounting hole on the cylinder plate, meeting the installation requirements of the penetrating component. Welding can then be performed. The operation is simple and convenient, and the equipment for checking and detecting the orientation of the penetrating component is relatively common and inexpensive, making it suitable for promotion in the field of nuclear power plants. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1A flowchart illustrating the installation and welding method for a nuclear power plant containment penetration component provided in an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of the through-hole component assembly installed on the cylindrical plate;

[0044] Figure 3 A schematic diagram of the through-hole component installed on the cylindrical plate;

[0045] Figure 4 This is a schematic diagram of measuring the center point of the end face of the penetration in step S220 of the installation and welding method for the penetration of the nuclear power plant containment structure provided in an embodiment of the present invention.

[0046] Figure 5 This is a schematic diagram showing the marking of the two center points on the two end faces of the penetration member as the first center point and the second center point in step S220 of the installation and welding method for the nuclear power plant containment penetration member provided in the embodiment of the present invention.

[0047] Figure 6 A schematic diagram of the auxiliary heating device provided in an embodiment of the present invention (only some heating elements and reinforcing mechanisms are shown);

[0048] Figure 7 for Figure 6 Top view of the auxiliary heating device;

[0049] Figure 8 The auxiliary heating device provided in the embodiment of the present invention is installed behind the penetrating member and the cylindrical plate.

[0050] Figure label:

[0051] 1-Penetrating component; 11-Insert plate; 2-Cylinder plate;

[0052] 3-Ring frame; 31-Clamping cavity; 32-Accommodation cavity; 33-Separated frame;

[0053] 4-Ear flap; 41-Card slot;

[0054] 5-Heating element;

[0055] 61-Flexible component; 62-Fixing pin;

[0056] 71-Threaded connector; 72-Nut; 73-First connecting bracket; 74-Second connecting bracket;

[0057] 81-Plumb box; 82-Plumb bob; 83-Level;

[0058] 91 - First center point; 92 - Second center point. Detailed Implementation

[0059] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] Example

[0063] Please see Figure 1 This embodiment provides a method for installing and welding a penetration component of a nuclear power plant containment structure. The welding method includes the following steps in sequence: S100, a hole-opening step, to open an installation hole for installing the penetration component 1 on the shell plate 2; S200, a penetration component hoisting and assembly step; S300, a welding step; S400, a post-weld non-destructive testing step; S500, a post-weld heat treatment step; S600, a post-heat treatment non-destructive testing step; and S700, a final shape and position inspection and corrosion protection.

[0064] Step S100 includes: S110, measuring and laying out lines to locate the opening position on the cylinder plate 2; S120, cutting the opening at the location and processing the cutting bevel; S130, inspecting the cutting bevel and detecting liquid penetration.

[0065] Specifically, step S110 includes: using a total station or other measuring tools to determine the angle line and elevation line where the center of the opening is located. The intersection of the angle line and the elevation line is the center point of the opening on the cylindrical plate 2. If the center of the fillet of the insert plate is not at the center of the through hole, the center of the fillet is accurately drawn based on the center of the through hole. Using the center point as a reference, and according to the dimensions of the through 1 and the insert plate, the opening cutting line is drawn on the cylindrical plate 2 using a scribe line, steel ruler, or other drawing tools. Specifically, before drawing the line, the dirt and oxide scale in the area to be drawn must be cleaned, and a cutting allowance should be reserved if necessary. When drawing the line, a line should be drawn on the inner and outer walls of the opening position on the cylindrical plate 2, one as the opening cutting line for cutting the straight bevel, and the other as the bevel edge line for bevel processing. An inspection line is set 100mm outside the bevel.

[0066] Step S120 includes: using a three-dimensional cutting machine or other cutting device to cut along the opening cutting line to form an installation hole for installing the through part 1; wherein, to prevent accuracy deviations during manual cutting, for the through part 1 with a larger size, a cutting allowance of 2mm-3mm needs to be reserved within the opening cutting line; after cutting, the cutting bevel is processed until the installation requirements of the through part 1 are met; wherein, during cutting, appropriate connecting accessories such as connecting lugs are welded to the part cut off on the cylinder plate 2, and a hand hoist or crane or other lifting tools are used in conjunction with the connecting accessories for lifting to prevent the cut-off part from suddenly falling and injuring people during cutting.

[0067] When using thermal cutting for hole cutting, preheating is required, and the preheating temperature should not be less than 120℃.

[0068] Step S130 includes: after the beveling is completed, beveling inspection and liquid penetration test are carried out as required. At the same time, finished product protection is provided for the completed beveling and the polished insert plate beveling to avoid rust or beveling damage.

[0069] The above step S200 includes: S210, hoisting the penetrating part 1 into the mounting hole and assembling it; S220, checking and adjusting the orientation of the penetrating part 1.

[0070] It should be noted that the penetrating member 1 includes both a penetrating member 1 without an insertion plate and a penetrating member 1 with an insertion plate. The penetrating member 1 without an insertion plate is as follows: Figure 3 As shown, the through-hole 1 is directly installed into the mounting hole of the cylindrical plate 2. The through-hole 1 with the insertion plate is as follows: Figure 2 As shown, the insertion plate of the penetrating member 1 is installed in the mounting hole of the cylindrical plate 2.

[0071] Therefore, step S210 includes: S211, hoisting the through-piece 1 without the insert plate into the mounting hole and assembling it, and S212, hoisting the through-piece 1 with the insert plate into the mounting hole and assembling it.

[0072] Specifically, step S211 includes: before hoisting the penetrating part 1, distinguishing the inner and outer sides of the penetrating part 1, determining the insertion position of the penetrating part 1 along the axial direction, and drawing a position marking line on the penetrating part 1 accordingly; selecting appropriate lifting lugs and rigging according to the weight and size of the penetrating part 1, hoisting the penetrating part 1 to the position of the mounting hole on the cylinder plate 2 according to the position marking line, and inserting it into the mounting hole; then welding clamps on both the cylinder plate 2 and the penetrating part 1, adjusting the weld gap and misalignment between the penetrating part 1 and the cylinder plate 2 through the clamps on the cylinder plate 2 and the penetrating part 1, and placing the clamps and the tack weld on the same side of the penetrating part 1.

[0073] Step S212 includes: integrating the insertion plate and the through-piece 1 into a through-piece assembly; before hoisting the through-piece assembly, distinguishing the inner and outer sides of the through-piece assembly and determining the axial insertion position of the through-piece assembly, and drawing position marking lines on the through-piece assembly accordingly; selecting appropriate lifting lugs and rigging according to the weight and size of the through-piece assembly, hoisting the through-piece assembly to the position of the mounting hole on the cylinder plate 2 according to the position marking lines, and inserting it into the mounting hole; then welding appropriate clamps on the cylinder plate 2 and the through-piece 1, adjusting the weld gap and misalignment between the through-piece 1 and the cylinder plate 2 using the clamps on the cylinder plate 2 and the through-piece 1, and placing the clamps and the tack weld on the same side of the through-piece 1.

[0074] Please see Figure 4 Step S220 includes: setting a plumb box 81 at the top of the end face of the penetrating member 1, so that the plumb 82 inside the plumb box 81 hangs down, thereby setting the plumb 82 radially in the vertical direction on the end face of the penetrating member 1; setting a level 83 on the end face of the penetrating member 1, and setting the level 83 radially in the horizontal direction on the end face of the penetrating member 1.

[0075] In this regard, please combine Figure 5The intersection of the level 83 and the plumb line 82 is the center point of the end face of the penetrating part 1. The two center points of the two end faces of the penetrating part 1 are marked as the first center point and the second center point 92, respectively. The first center point and the second center point 92 are measured using a total station. The central axis of the penetrating part 1 is measured through the line connecting the first center point and the second center point 92. The position of the center point of the penetrating part 1 is measured through the midpoint of the line connecting the first center point and the second center point 92. The position of the center axis of the penetrating part 1 is then compared with the position of the central axis of the mounting hole on the cylindrical plate 2. Yes, and compare the center point of the penetrating part 1 with the center point of the mounting hole on the cylindrical plate 2 to check the orientation of the penetrating part 1; if the center axis of the penetrating part 1 is not consistent with the center axis of the mounting hole on the cylindrical plate 2, adjust the penetrating part 1 so that the center axis of the penetrating part 1 is consistent with the center axis of the mounting hole on the cylindrical plate 2; if the center point of the penetrating part 1 is not consistent with the center point of the mounting hole on the cylindrical plate 2, adjust the penetrating part 1 so that the center point of the penetrating part 1 is consistent with the center point of the mounting hole on the cylindrical plate 2.

[0076] The welding method of this embodiment firstly involves opening an installation hole on the cylindrical plate 2 in step S100, then hoisting the through-part 1 into the installation hole in step S210 and assembling it, then checking and adjusting the position of the through-part 1 in step S220, and then welding the welding part between the through-part 1 and the cylindrical plate 2 in step S300, thus completing the welding of the through-part 1 onto the cylindrical plate 2.

[0077] In this process, after the penetrating component 1 is hoisted into the mounting hole and assembled, the orientation of the penetrating component 1 is checked and adjusted in step S220 to ensure that the central axis of the penetrating component 1 is consistent with the central axis of the mounting hole on the cylindrical plate 2, and that the center point of the penetrating component 1 is consistent with the center point of the mounting hole on the cylindrical plate 2. This ensures that the relative position of the penetrating component 1 and the mounting hole on the cylindrical plate 2 is more accurate, reduces the deviation of the position of the penetrating component 1 relative to the cylindrical plate 2 after the penetrating component 1 is welded to the cylindrical plate 2, and improves the safety and structural integrity of the containment.

[0078] It should be noted that in step S220, the vertical diameter direction on the end face of the penetrating component 1 is determined by the plumb bob 81, and the horizontal radial direction on the end face of the penetrating component 1 is determined by the level 83. The center point of the end face of the penetrating component 1 is determined by the intersection of the two. Then, the first center point and the second center point 92 are measured by the total station to determine the central axis and the center point position of the penetrating component 1. The above two parameters are then compared one by one with the central axis and the center point position of the mounting hole on the cylinder plate 2 to check the orientation of the penetrating component 1. If the check is not qualified, the orientation of the penetrating component 1 is adjusted so that the central axis and the center point position of the penetrating component 1 correspond one by one with the central axis and the center point position of the mounting hole on the cylinder plate 2, satisfying the installation requirements of the penetrating component 1. Welding can then be performed. The operation is simple and convenient, and the device for checking and detecting the orientation of the penetrating component 1 is relatively common and inexpensive, making it suitable for promotion in the field of nuclear power plants.

[0079] In step S300 above, it should be noted that the part between the through-piece assembly and the cylindrical plate 2, or between the through-piece 1 and the cylindrical plate 2, is the part that needs to be welded. Specifically, step S300 includes: S310, preheating the welding part by means of an auxiliary heating device; S320, performing tack welding on the welding part; S330, welding the welding part.

[0080] In step S310, the auxiliary heating device includes a thermometer, a temperature controller, and a heating element 5. The thermometer is used to monitor the temperature of the welding side of the welding area, and the heating element 5 is used to heat the welding area. Both the thermometer and the heating element 5 are connected to the temperature controller. The temperature controller can preset the preheating temperature range and preheating time, and correspondingly control the heating temperature and heating time of the heating element 5. Specifically, the preheating temperature range includes an upper temperature limit and a lower temperature limit. When the heating element 5 is powered on, it gradually raises the temperature of the welding area until the temperature of the welding area reaches the preset upper temperature limit. At this time, the heating element 5 is powered off. When the temperature of the welding area reaches the preset lower temperature limit, it is powered on. At this time, the heating element 5 raises the temperature of the welding area, thereby keeping the welding area constant between the upper temperature limit and the lower temperature limit, ensuring that the welding area and the surrounding base material are heated evenly.

[0081] Preferably, please refer to Figure 6 and Figure 7 and combined Figure 8 The auxiliary heating device also includes a clamping mechanism, which includes an annular frame 3. The annular frame 3 has a clamping cavity 31 that matches the through piece 1. On the side of the annular frame 3 away from the clamping cavity 31, there are multiple receiving cavities 32 for accommodating the heating element 5. The multiple receiving cavities 32 are evenly distributed along the circumference of the annular frame 3, and the heating element 5 is clamped in the receiving cavity 32.

[0082] When using the auxiliary heating device, the annular frame 3 is fitted over the through piece 1, so that the through piece 1 is located in the clamping cavity 31, and the annular frame 3 abuts against the cylindrical plate 2. Then, multiple heating elements 5 are clamped into multiple receiving cavities 32 one by one.

[0083] In this auxiliary heating device, since multiple receiving cavities 32 are evenly distributed along the circumference of the annular frame 3, after the heating element 5 is installed in the receiving cavity 32, the multiple heating elements 5 are evenly distributed along the circumference of the annular frame 3, so the layout of the multiple heating elements 5 is uniform, which can uniformly heat all parts of the weld, and will not cause local overheating or insufficient heating of the welded part, thus improving the uniformity of the heating process.

[0084] Specifically, see Figure 6 and Figure 7 Multiple ear flaps 4 are provided on the side of the annular frame 3 away from the clamping cavity 31. The multiple ear flaps 4 are evenly distributed along the circumference of the annular frame 3, and a receiving cavity 32 is formed between adjacent ear flaps 4.

[0085] Preferably, in this embodiment, the auxiliary heating device further includes a reinforcing mechanism, which is used to fasten the heating element 5 to the surface of the cylindrical plate 2.

[0086] Please see Figure 6 and Figure 7 As one possible approach, the reinforcement mechanism includes a flexible element 61 and a fixing pin 62. One end of the flexible element 61 is fixed to the annular frame 3, and the other end is fixed to the fixing pin 62. The ear flap 4 is provided with a locking hole 41, and the fixing pin 62 can be inserted into the locking hole 41. After the fixing pin 62 is inserted into the locking hole 41, the two ends of the fixing pin 62 are located on both sides of the locking hole 41, and can respectively abut against the two heating elements 5 on both sides of the locking hole 41, so that the heating elements 5 are locked between the fixing pin 62 and the cylindrical plate 2, thereby the heating elements 5 are fastened to the surface of the cylindrical plate 2.

[0087] With this setup, after the heating element 5 is placed in the receiving cavity 32, the fixing pin 62 is inserted into the locking hole 41. At this time, the two ends of the fixing pin 62 are located on both sides of the locking hole 41, and the two ends of the fixing pin 62 can respectively abut against the two heating elements 5 on both sides of the locking hole 41, so that the heating element 5 is locked between the fixing pin 62 and the cylinder plate 2, thus realizing that the heating element 5 is fastened to the surface of the cylinder plate 2, and the surface of the cylinder plate 2 can be heated.

[0088] Preferably, as shown in Figure 6, in this embodiment, the annular frame 3 includes multiple sub-frames 33, which are sequentially connected end to end to form a clamping cavity 31, and adjacent sub-frames 33 are connected by connecting components.

[0089] For example, see Figure 6The adjacent sub-frames 33 are the first sub-frame and the second sub-frame, respectively. The connecting components include a threaded connector 71, a nut 72, a first connecting frame 73 disposed on the first sub-frame, and a second connecting frame 74 disposed on the second sub-frame. Both the first connecting frame 73 and the second connecting frame 74 are provided with connecting holes. The threaded connector 71 can pass through the connecting holes on the first connecting frame 73 and the second connecting frame 74 and then be tightened by the nut 72.

[0090] Specifically, when the outer diameter of the through-piece 1 is large, the portion of the threaded connector 71 located between the first connecting frame 73 and the second connecting frame 74 is longer, resulting in a larger distance between the first connecting frame 73 and the second connecting frame 74. This increases the gap between adjacent sub-frames 33, and the clamping cavity 31 is larger, enabling it to accommodate the through-piece 1 with a larger outer diameter. When the outer diameter of the through-piece 1 is small, the portion of the threaded connector 71 located between the first connecting frame 73 and the second connecting frame 74 is shorter, resulting in a smaller distance between the first connecting frame 73 and the second connecting frame 74. This decreases the gap between adjacent sub-frames 33, and the clamping cavity 31 is smaller, enabling it to accommodate the through-piece 1 with a smaller outer diameter.

[0091] This configuration allows for adjustable gaps between adjacent subframes 33, enabling adjustment of the size of the clamping cavity 31 of the annular frame 3. This allows for the application of both large and small outer diameter penetrations 1, meaning it can be used for containment penetrations 1 in different nuclear power plants with significant differences in size, shape, and structure. It provides sufficient flexibility and adjustability, improves the adaptability of the auxiliary heating device, and enables effective installation and use when encountering penetrations 1 of different specifications, thereby reducing construction and time costs.

[0092] Preferably, in this embodiment, the auxiliary heating device further includes insulation cotton disposed on the welding side. The insulation cotton is used to cover the back side area of ​​the weld during the preheating process to reduce heat loss.

[0093] Optionally, the thermometer is a thermocouple or a non-contact infrared thermometer used to monitor the temperature on the weld side. For areas with a large weld thickness, the thermometer needs to monitor the temperature of the inner and outer surfaces of the weld.

[0094] It should be noted that, firstly, during the entire preheating process, a thermometer is used to monitor the temperature of the welding area in real time. The temperature monitoring points should be arranged to cover all critical parts of the area to be welded, especially the edges and thicker parts of the through-piece 1, to prevent temperature blind spots. The temperature controller is connected to the heating element 5 and can automatically adjust the heating intensity of the heating element 5 when the temperature deviation exceeds the preset range.

[0095] In addition, the preheating temperature is usually not lower than 150℃. For thicker parts on the through-hole 1, the appropriate preheating power and preheating time should be set according to the thickness of the base material to ensure that the heat can be evenly transferred to the entire welding area.

[0096] Furthermore, it should be added that during welding preheating, the heating element 5 should be preheated on the back side of the welding side, and the temperature should be measured on the welding side using a thermometer. For areas with a large weld thickness, a double-sided temperature detection method should be used, measuring the temperature on both the inner and outer surfaces of the weld to verify temperature uniformity. If the measured temperature difference exceeds the standard range, local supplementary heating is required.

[0097] In step S320 above, the gap and misalignment of the weld group can be adjusted while tack welding is performed to ensure that the gap and misalignment of the weld group meet the requirements. The length range of the tack weld is 50mm-100mm and the spacing is 250mm-300mm.

[0098] In addition, tack welding should be performed on the outside of the cylindrical plate 2. After tack welding, several workstations should be allocated according to the weld length of the through part 1 or the insert plate, and multiple welders should be arranged to perform welding symmetrically. After the welding of the root layer and part of the filler layer is completed, the back of the weld should be cleaned. Plasma gouging, carbon arc gouging plus cleaning, or direct grinding can be used for cleaning. The cleaning and grinding should be smooth to facilitate the next layer of welding. After cleaning and grinding, relevant non-destructive testing should be performed.

[0099] In step S330, during the welding process, the temperature of the welding area needs to be continuously monitored to ensure that the temperature changes are stable during the welding process and to prevent cracks or thermal stress concentration in the weld.

[0100] During the welding process between the through part 1 or the insert plate and the cylindrical plate 2, an auxiliary heating device is installed on the reverse side of the welding area. For irregularly shaped circular insert plates, the auxiliary heating device can be a trapezoidal heating element 5 or a rectangular heating element 5. If an electric heating element 5 is used, insulation cotton must be laid on the welding side to ensure that the preheating temperature of the side to be welded is not lower than 150°C.

[0101] In step S400 above, after the welding of the penetrating part 1 or the penetrating part assembly is completed, and after the stress stabilizes and the hydrogen content diffusion time is satisfied, relevant non-destructive testing is performed, such as visual inspection, liquid penetration testing, radiographic testing and ultrasonic testing.

[0102] In step S500 above, after welding is completed, the weld seam of the welded part is immediately subjected to post-heating, and heat insulation cotton is placed on the welding side. The post-heating temperature range of the weld seam between the penetrating part 1 and the cylinder plate 2 is 200℃-350℃, and the post-heating time is not less than 30 minutes; the post-heating temperature range of the weld seam between the insert plate and the cylinder plate 2 is 200℃-350℃, and the post-heating time is not less than 2 hours.

[0103] If welding and preheating need to be stopped before the weld at the welding point is completed, the weld at the welding point should be completed at least 25 mm or 25% of the weld thickness, and the postheating time should be at least 2 hours, with a postheating temperature range of 250℃-350℃.

[0104] It should be noted that after the post-heating is completed, the insulation cotton and the heating element 5 of the auxiliary heating device should not be removed until the temperature at the weld of the welded part drops to the ambient temperature.

[0105] In step S600 above, for the through-hole component 1 and through-hole component assembly that require post-weld heat treatment, the liquid penetration test is carried out after the weld is qualified; for the through-hole component assembly weld heat treatment, 15% of the welds are randomly selected for liquid penetration test again, and the T-joint of the weld must be selected.

[0106] It should be noted that steps S500 and S600 are optional welding steps, and whether or not to perform steps S500 and S600 should be selected according to actual needs.

[0107] In step S700 above, after all relevant inspections of the weld connecting the penetrating part 1 or penetrating part assembly to the cylinder plate 2 are completed, the final shape and position inspection and corrosion protection are performed.

[0108] In summary, the welding method of this embodiment has the following advantages:

[0109] (1) Improve welding quality: By using reasonable preheating methods, the temperature gradient during the welding process can be reduced, thermal stress concentration can be avoided, and the probability of material cracks can be reduced, thereby significantly improving welding quality.

[0110] (2) Energy saving: This embodiment uses trapezoidal or rectangular heating element 5 and is supplemented with heat insulation cotton, which effectively reduces heat loss, improves heating efficiency and reduces energy consumption.

[0111] (3) Enhance the precision and consistency of operation: The auxiliary heating device in this embodiment can flexibly adjust the heating method according to the different shapes and sizes of the penetrating part 1, while real-time temperature monitoring and control, to ensure the precision of operation and improve the stability of construction.

[0112] (4) The center point of the end face of the penetrating component 1 is found using a plumb bob 81 and a spirit level 83. This method is highly accurate, reduces human error, and provides a reliable foundation for subsequent steps. Secondly, the center points of both end faces are measured using a total station to obtain multi-dimensional data, ensuring a comprehensive and scientific assessment. Finally, adjustments are made based on the results to ensure accurate axis orientation and guarantee project quality and safety.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of installing and welding a containment penetration of a nuclear power plant, characterized in that, include: S100, the drilling step, to create a mounting hole in the cylindrical plate (2) for mounting the through member (1); S200, the hoisting and assembly steps of the penetrating component; the steps S200 include: S210, the penetrating component (1) is hoisted into the mounting hole and assembled; S220, the orientation of the penetrating component (1) is checked and adjusted; S300, Welding step, welding is performed on the welding part between the through part (1) and the cylindrical plate (2); Step S220 includes: A plumb bob box (81) is provided at the top of the end face of the penetrating member (1), so that the plumb bob (82) inside the plumb bob box (81) hangs down, thereby making the plumb bob (82) radially arranged in the vertical direction on the end face of the penetrating member (1); a level (83) is provided on the end face of the penetrating member (1), and the level (83) is radially arranged in the horizontal direction on the end face of the penetrating member (1); The intersection of the level (83) and the plumb line (82) is the center point of the end face of the penetrating member (1), and the two center points of the two end faces of the penetrating member (1) are marked as the first center point (91) and the second center point (92) respectively. The first center point (91) and the second center point (92) are measured with a total station. The central axis of the penetrating member (1) is measured through the line connecting the first center point (91) and the second center point (92). The center point position of the penetrating member (1) is measured through the midpoint of the line connecting the first center point (91) and the second center point (92). The orientation of the through-piece (1) is checked by comparing the position of the central axis of the through-piece (1) with the position of the central axis of the mounting hole on the cylindrical plate (2) and comparing the position of the center point of the through-piece (1) with the position of the center point of the mounting hole on the cylindrical plate (2). If the central axis of the through member (1) is not aligned with the central axis of the mounting hole on the cylindrical plate (2), adjust the through member (1) so that the central axis of the through member (1) is aligned with the central axis of the mounting hole on the cylindrical plate (2); if the center point of the through member (1) is not aligned with the center point of the mounting hole on the cylindrical plate (2), adjust the through member (1) so that the center point of the through member (1) is aligned with the center point of the mounting hole on the cylindrical plate (2). Step S300 includes: S310, preheating the welding area using an auxiliary heating device; S320, performing tack welding on the welding area; and S330, welding the welding area. The auxiliary heating device also includes a clamping mechanism, which includes an annular frame (3). The annular frame (3) has a clamping cavity (31) that matches the through piece (1). On the side of the annular frame (3) away from the clamping cavity (31), there are multiple receiving cavities (32) for accommodating the heating element (5) of the auxiliary heating device. The multiple receiving cavities (32) are evenly distributed along the circumference of the annular frame (3). The heating element (5) is clamped in the receiving cavity (32). The annular frame (3) has multiple ear flaps (4) on the side away from the clamping cavity (31). The multiple ear flaps (4) are evenly distributed along the circumference of the annular frame (3), and the receiving cavity (32) is formed between adjacent ear flaps (4). The auxiliary heating device also includes a reinforcing mechanism, which is used to fasten the heating element (5) to the surface of the cylindrical plate (2); The reinforcement mechanism includes a flexible component (61) and a fixing pin (62). One end of the flexible component (61) is fixed to the annular frame (3), and the other end is fixed to the fixing pin (62). The ear flap (4) is provided with a locking hole (41), and the fixing pin (62) can be inserted into the locking hole (41). After the fixing pin (62) is inserted into the locking hole (41), the two ends of the fixing pin (62) are located on both sides of the locking hole (41) and can respectively abut against the two heating elements (5) on both sides of the locking hole (41), so that the heating element (5) is locked between the fixing pin (62) and the cylindrical plate (2), thereby the heating element (5) is fastened to the surface of the cylindrical plate (2).

2. The containment-penetrating-member installation welding method of claim 1, characterized by, Step S210 includes: S211, the through piece (1) without the insert plate (11) is hoisted into the mounting hole and assembled; and S212, the through piece (1) with the insert plate (11) is hoisted into the mounting hole and assembled. Step S211 includes: before hoisting the penetrating part (1), distinguishing the inner and outer sides of the penetrating part (1), determining the insertion position of the penetrating part (1) along the axial direction, and drawing a position marking line on the penetrating part (1); hoisting the penetrating part (1) to the position of the mounting hole on the cylindrical plate (2) according to the position marking line, and inserting it into the mounting hole; then welding clamps on both the cylindrical plate (2) and the penetrating part (1), and adjusting the weld gap and misalignment between the penetrating part (1) and the cylindrical plate (2) using the clamps on the cylindrical plate (2) and the penetrating part (1); Step S212 includes: integrating the insertion plate (11) and the through piece (1) into a through piece assembly; before hoisting the through piece assembly, distinguishing the inner and outer sides of the through piece assembly and determining the axial insertion position of the through piece assembly, and drawing a position marking line on the through piece assembly accordingly; hoisting the through piece assembly to the position of the mounting hole on the cylindrical plate (2) according to the position marking line, and installing it into the mounting hole; then welding clamps on both the cylindrical plate (2) and the through piece (1), and adjusting the weld gap and misalignment between the through piece (1) and the cylindrical plate (2) using the clamps on the cylindrical plate (2) and the through piece (1).

3. The method for installing and welding the penetration component of the nuclear power plant containment structure according to claim 2, characterized in that, In step S300, the part between the through-piece assembly and the cylindrical plate (2), or the part between the through-piece (1) and the cylindrical plate (2), is the part that needs to be welded. In step S310, the auxiliary heating device includes a thermometer, a temperature controller and a heating element (5). The thermometer is used to monitor the temperature of the welding part, and the heating element (5) is used to heat the welding part. Both the thermometer and the heating element (5) are connected to the temperature controller. The temperature controller can preset the preheating temperature range and preheating time. The preheating temperature range includes an upper temperature limit and a lower temperature limit. The heating element (5) is powered on and started. The heating element (5) can raise the temperature of the welding part until the temperature of the welding part reaches the upper temperature limit. Then the heating element (5) is powered off. When the temperature of the welding part reaches the lower temperature limit, the heating element (5) is powered on and started. At this time, the heating element (5) raises the temperature of the welding part.

4. The method for installing and welding the penetration component of the nuclear power plant containment structure according to claim 1, characterized in that, The ring frame (3) includes multiple sub-frames (33), which are connected end to end to form the clamping cavity (31). Adjacent sub-frames (33) are connected by a connecting component, and the connecting component can adjust the gap between adjacent sub-frames (33).

5. The method for installing and welding the penetration component of the nuclear power plant containment structure according to claim 4, characterized in that, The adjacent sub-frames (33) are respectively the first sub-frame and the second sub-frame; The connecting assembly includes a threaded connector (71), a nut (72), a first connecting frame (73) disposed on the first sub-frame, and a second connecting frame (74) disposed on the second sub-frame. Both the first connecting frame (73) and the second connecting frame (74) are provided with connecting holes. The threaded connector (71) can pass through the connecting holes on the first connecting frame (73) and the second connecting frame (74) and then be tightened by the nut (72).

6. The method for installing and welding a penetration member of a nuclear power plant containment structure according to any one of claims 2-5, characterized in that, Step S100 includes: S110, measuring and laying out lines to locate the opening position on the cylindrical plate (2); S120, cutting the opening at the location and processing the cutting bevel; S130, inspecting the cutting bevel and detecting liquid penetration. The step S110 includes: using a measuring tool to determine the angle line and elevation line where the center of the opening is located, and the intersection of the angle line and the elevation line is the center point of the opening on the cylindrical plate (2); using the center point as a reference, using a drawing tool to draw the opening cutting line on the cylindrical plate (2). Step S120 includes: using a cutting device to cut along the opening cutting line to form an installation hole for installing the through part (1); after cutting, processing the cutting bevel; Step S130 includes: after the beveling process is completed, beveling inspection and liquid penetration detection are performed.

7. The method for installing and welding the penetration component of the nuclear power plant containment structure according to any one of claims 2-5, characterized in that, Following step S300, the method for installing and welding the nuclear power plant containment penetration component further includes, in sequence: S400, post-weld non-destructive testing steps: after the welding of the penetrating part (1) or the penetrating part assembly is completed, visual inspection, liquid penetration test, radiographic test and ultrasonic test are performed. S500, Post-heating and post-weld heat treatment steps: After welding is completed, the weld seam of the welded part is subjected to post-heating; wherein, the post-heating temperature range of the weld seam between the through part (1) and the cylindrical plate (2) is 200℃-350℃, and the post-heating time is not less than 30min; the post-heating temperature range of the weld seam between the insert plate (11) and the cylindrical plate (2) is 200℃-350℃, and the post-heating time is not less than 2 hours; S600, Non-destructive testing steps after heat treatment.

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