Ray inspection device and method for pipe and pipe plate welding seam of steam generator and superheater

Abstract

The invention belongs to the technical field of nuclear power, and particularly relates to a steam generator and superheater tube plate welding seam ray inspection device and method. The ray inspection device is used for in-service, factory-leaving and pre-service inspection of steam generator and superheater tube and tube plate welding seams and can be remotely controlled, and the risk of personnel irradiation is greatly reduced. Exposure is carried out below a tube plate through a rod anode and a film plate fixing device, and the device is suitable for various stack types. The film plate supports quick replacement and automatic film replacement functions, so that the efficiency is improved; the rod anodes can be symmetrically installed and adjusted in direction to avoid interference with the inner wall of to-be-detected equipment. The tool is fixed through pneumatic toes, can be controlled through a simple air valve, is convenient to install, supports single-person handheld and remote operation, and is integrally safe and efficient.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power technology, specifically relating to a radiographic inspection device and method for weld seams of steam generator and superheater tube sheets. Background Technology

[0002] Nuclear power plants have various types of heat exchangers that operate under high radioactivity, high temperature, and high pressure environments for extended periods. To prevent radioactive leaks, these devices must undergo non-destructive testing before and after commissioning. Among the inspection targets are the welds connecting the heat transfer tubes and tube sheets of steam generators and superheaters, with radiographic inspection being a crucial method for detecting weld defects.

[0003] The in-service radiographic inspection of the tube sheet welds of the steam generator and superheater differs in structure and method from the factory and pre-service inspections. During the in-service inspection phase, the steam generator and superheater are in a vertical position. In related technologies, X-ray sources and cassettes are commonly used for factory and pre-service inspections. However, during in-service inspections, the radiographic inspection equipment cannot be directly placed on the tube sheet below the steam generator and superheater of the demonstration fast reactor. Inspection personnel must stand under the tube sheet holding the radiographic inspection tools, enduring significant radiation exposure during the exposure period. Therefore, inspection personnel cannot stand under the equipment during exposure. Currently, there is a lack of equipment that allows for in-service radiographic inspection of the tube sheet welds of the steam generator and superheater of the demonstration fast reactor using a radiographic source and cassette. Summary of the Invention

[0004] To overcome the problems existing in related technologies, a device and method for radiographic inspection of weld seams in tube sheets of steam generators and superheaters are provided.

[0005] According to one aspect of the present disclosure, a radiographic inspection apparatus for weld seams of tube sheets in steam generators and superheaters is provided, the apparatus comprising:

[0006] Pneumatic toes are used to tighten and fix the device to the inner wall of the tube hole of the equipment to be inspected.

[0007] The rod anode serves as the radiation source.

[0008] A rod anode fixing device connects the pneumatic toe to the rod anode, and is used to fix and restrict the degree of freedom of the rod anode;

[0009] Film plate, used to hold exposure film; and,

[0010] A film plate fixing device connects the pneumatic toe to the film plate;

[0011] The pneumatic toe, the rod anode, the rod anode fixing device, the film plate, and the film plate fixing device are connected as a whole. The anode head of the rod anode can pass through the film hole on the film plate and be inserted into the tube hole to be inspected.

[0012] In one possible implementation, the pneumatic toe includes a lifting stroke rod and a claw; the lifting stroke rod is configured to drive the claw to expand and tighten against the inner wall of the tube when air is pushed out, and to drive the claw to close and disengage from the tube when retracted.

[0013] In one possible implementation, the rod anode fixing device includes:

[0014] The rod anode fixing bracket is U-shaped and is used to support the main body of the rod anode;

[0015] A rod anode fixing cover plate is connected to the rod anode fixing bracket via a split connection, fixing the main body of the rod anode between the two.

[0016] A rod anode fixing ring is fixed to the rod anode fixing cover plate; and...

[0017] The rod anode retaining ring is connected to the rod anode fixing ring via a split connection and is used to hold the anode head of the rod anode tightly.

[0018] In one possible implementation, the two ends of the rod anode fixing cover are symmetrical, and the rod anode fixing ring and the rod anode retaining ring can be selectively installed at either end of the rod anode fixing cover.

[0019] In one possible implementation, the film plate fixing device includes:

[0020] Film plate fixing plate;

[0021] A film plate fixing sleeve is installed in the fixing hole of the film plate by interference fit and is threadedly connected to the film plate fixing plate; and,

[0022] A positioning pin, installed on the film plate fixing plate, is used to insert into the tube hole to restrict the rotation of the film plate.

[0023] In one possible implementation, the film plate is connected to the film plate fixing device by fixing screws.

[0024] In one possible implementation, the rod anode includes a rod anode body, cooling vents formed on the rod anode body, an anode head, and a spring retainer plate disposed on the anode head.

[0025] In one possible implementation, the film plate includes a film base plate, a film cover plate, and a fixing nut;

[0026] The film base plate and the film cover plate are used to clamp the exposure film and are fixed by the fixing nut;

[0027] The fixing nut has a slot for engaging with the spring plate on the anode head of the rod anode.

[0028] According to another aspect of the present disclosure, a method for radiographic inspection of weld seams in tube sheets of steam generators and superheaters is provided. The method is implemented based on the aforementioned apparatus and includes:

[0029] Step 1: Install the film plate onto the film plate fixing device and align the film hole with the tube hole to be inspected;

[0030] Step 2: Insert the pneumatic toe and the positioning pin into the corresponding tube hole, and ventilate to inflate the claw of the pneumatic toe, thus fixing the entire device under the tube plate;

[0031] Step 3: Fix the rod anode using the rod anode fixing device, and insert the anode head through the film hole of the film plate into the tube hole to be inspected;

[0032] Step 4: Remotely control the rod anode to perform X-ray exposure;

[0033] Step 5: After exposure is complete, reverse ventilation is used to close the pneumatic toe claws, and the entire device is removed from the tube sheet.

[0034] In one possible implementation, when inspecting the edge tube hole, the installation positions of the rod anode fixing ring and the rod anode clamping ring in the rod anode fixing device on the rod anode fixing cover plate are adjusted so that the side where the pneumatic toe is located faces away from the inner wall of the equipment, thus avoiding interference with the inner wall.

[0035] The beneficial effects of this disclosure are as follows: This disclosure uses a radiation source and a dark box to complete the in-service radiation inspection of the weld seams of the tube sheet of the steam generator and superheater. During the radiation inspection, the staff can operate remotely, avoiding the need for the staff to stand under the equipment during the exposure period and reducing the radiation dose level of the operators. Attached Figure Description

[0036] Figure 1 This is a schematic diagram illustrating the rod anode fixing state of a radiographic inspection device for weld seams of steam generator and superheater tubes and tube sheets according to an exemplary embodiment.

[0037] Figure 2 This is a schematic diagram illustrating the film plate fixing state of a radiographic inspection device for weld seams of steam generator and superheater tubes, according to an exemplary embodiment.

[0038] Figure 3This is a schematic diagram of the structure of a rod anode of a radiographic inspection device for weld seams of a steam generator and superheater tube sheet, according to an exemplary embodiment.

[0039] Figure 4 This is a schematic diagram of the structure of a film plate for a radiographic inspection device for weld seams of a steam generator and superheater tube sheet, according to an exemplary embodiment.

[0040] Figure 5 This is a schematic diagram illustrating the installation of a radiographic inspection device for weld seams of a steam generator and superheater tube sheet at the edge of the tube sheet, according to an exemplary embodiment.

[0041] Figure 6 This is a schematic diagram illustrating another state of a radiographic inspection device for weld seams of a steam generator and superheater tube sheet, installed at the edge of the tube sheet, according to an exemplary embodiment.

[0042] In the picture:

[0043] 1. Pneumatic toe, 2. Anode rod, 3. Anode rod fixing device, 4. Anode rod fixing cover plate.

[0044] 5. Anode fixing bracket, 6. Anode fixing ring, 7. Anode retaining ring, 8. Film plate

[0045] 9. Film plate fixing device; 10. Film plate fixing plate; 11. Film plate fixing sleeve; 12. Fixing screws.

[0046] 13 Positioning pin, 14 Anode body, 15 Cooling vent, 16 Anode head, 17 Spring clip Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Based on the structure of the steam generator and superheater tube sheet and heat transfer tube, and its vertical characteristics during in-service inspection, this disclosure uses a pneumatic toe 1 to fix the entire device below the tube sheet. A rod anode 2 fixing bracket connects the toe and the rod anode 2, and a film plate 8 fixing bracket connects the toe and the film plate 8. The rod anode 2 serves as the X-ray source for X-ray inspection, and the film plate 8 serves as the X-ray inspection cassette.

[0049] The pneumatic toe 1 includes a lifting stroke rod and a foot claw. When the cylinder stroke rod is vented, it pushes out to expand the foot claw. The foot claw tightens on the inner wall of the tube hole of the tube sheet, and the friction fixes the foot claw below the tube hole. When the cylinder stroke rod retracts, the foot claw closes and the toe disengages from the tube hole.

[0050] The rod anode fixing device 3 consists of a rod anode fixing bracket 5, a rod anode fixing cover plate 4, a rod anode fixing ring 6, and a rod anode clamping ring 7. The rod anode fixing bracket 5 is U-shaped, with the U-shaped groove supporting the anode body. The rod anode fixing cover plate 4 is used to fix it on top. The rod anode fixing bracket 5 and the rod anode fixing cover plate 4 are connected by a half-connection to restrict the movement of the rod anode 2. The rod anode fixing ring 6 is fixed to the rod anode fixing cover plate 4 with screws. The rod anode fixing cover plate 4 is symmetrical at both ends, allowing the rod anode fixing ring 6 to be installed at both ends respectively. The rod anode clamping ring 7 is connected to the rod anode fixing ring 6 by a half-connection to fix the anode head 16 of the rod anode 2, restricting the movement and rotation of the rod anode 2. The rod anode fixing device 3 connects the rod anode 2 and the pneumatic toe 1 into one unit and completes the restriction of the rod anode 2's degrees of freedom.

[0051] The film plate fixing device consists of a film plate fixing plate, a film plate fixing sleeve, fixing screws 12 and positioning pins 13. The film plate fixing sleeve is installed in the fixing hole of the film plate 8 by interference fit. The film plate fixing plate and the film plate fixing sleeve are connected by threads to connect the film plate 8 and the film plate fixing plate. The positioning pins 13 are installed on the film plate fixing plate. The film fixing device connects the film plate 8 and the pneumatic toe 1 into one unit.

[0052] The rod anode 2 consists of a rod anode body 14, cooling vents 15, an anode head 16, and a spring clamp 17. The anode head 16 emits rays, the cooling vents 15 vent to cool the rod anode 2, and the spring clamp 17 fixes the anode head 16.

[0053] The film plate 8 consists of a film base plate, a film cover plate, and a fixing nut. The exposure film is placed between the film base plate and the film cover plate. The fixing nut fixes the film base plate and the film cover plate. At the same time, the fixing nut has a slot, which, together with the spring clip 17 of the rod anode 2, connects and fixes the film plate 8 and the anode head 16.

[0054] like Figure 2 and Figure 4 As shown, the film plate 8 is fixed to the film plate fixing device 9 by fixing screws 12, the film hole is aligned with the hole to be inspected, and the pneumatic toe 1 and positioning pin 13 are inserted into the tube hole to restrict the rotation of the film plate and fix it by air.

[0055] like Figure 1 and Figure 3 As shown, the rod anode 2 is fixed and restricted by the rod anode fixing device 3. The rod anode fixing bracket 5 supports the rod anode in a U-shaped groove. The rod anode fixing cover plate 4 is connected to the rod anode fixing bracket 5 from above through a half-connection, fixing the rod anode 2 between the two. The rod anode fixing cover plate 4 is connected to the rod anode fixing ring 6. The rod anode fixing ring 6 and the rod anode clamping ring 7 are connected through a half-connection, clamping the anode head 16 to prevent the rod anode 2 from moving and rotating.

[0056] The anode head 16 passes through the film plate hole and is inserted into the tube hole. The pneumatic toe 1 is inserted into the corresponding tube hole. The spring clip 17 on the anode head 16 is inserted into the slot of the film plate fixing nut 20. The pneumatic toe 1 is vented and the claw expands to fix the entire device under the tube plate.

[0057] like Figure 5 and Figure 6 As shown, when inspecting the edge hole, the pneumatic toe end of the rod anode fixing device 3 may interfere with the inner wall of the equipment under inspection, making the inspection impossible. In this case, the rod anode fixing ring 6 and the rod anode retaining ring 7 in the rod anode fixing device 3 are installed on the symmetrical side of the rod anode fixing cover plate 4, with the pneumatic toe side facing away from the inner wall to prevent the pneumatic toe 1 from interfering with the inner wall.

[0058] The remotely controlled rod anode 2 is used for X-ray inspection. Exposure is performed on the film near the hole to be inspected. After exposure, the rod anode fixing device 3 is removed from the tube sheet. The anode head 16 of the rod anode 2 is inserted into the uninspected hole of the film plate and the rod anode fixing device 3 is fixed again. After all the inspection holes of the film plate are exposed in sequence, the fixing screws 12 on the film plate fixing device 9 are removed and the prepared unexposed film plate is installed. After installation, the X-ray inspection of the tube hole to be inspected is continued.

[0059] Compared to existing technologies, the beneficial effects of this disclosure are as follows:

[0060] To reduce radiation exposure, this device can replace the manual fixing of the X-ray source to complete the in-service inspection of tube and tube sheet welds. During the exposure period, the inspection personnel can operate it remotely without being exposed to the X-ray source.

[0061] With a wide range of applications, this inspection device is not only suitable for demonstration fast reactors, but can also be used for in-service radiographic inspection of weld seams in heat transfer tubes and tube sheets of various reactor types.

[0062] With a wide range of testing scenarios, this X-ray inspection tool is mainly used for in-service inspection of vertical evaporators and superheaters, but it also has the function of completing factory and pre-service inspections.

[0063] The main function of the radiographic inspection tool is to perform radiographic inspection of the weld seams of the tube sheet of the steam generator and superheater. The rod anode fixing device and the film plate fixing device fix the rod anode and the film plate under the tube sheet. The anode head is inserted into the tube hole to perform radiographic inspection and exposure on the film.

[0064] The film plate can be quickly replaced. The film fixing device, combined with pneumatic toes, fixes the film plate under the tube sheet. The film plate fits the weld seam. Multiple inspection holes are inspected in sequence. After all inspection holes have been exposed, the screws on the film fixing device are removed, a new film plate is replaced, and the inspection continues.

[0065] The film can be automatically changed. After all the holes on the film have been exposed, the device can automatically change the film, eliminating the need for manual disassembly and saving time.

[0066] The rod anodes can be installed symmetrically. The rod anode bracket and rod anode fixing cover plate in the rod anode fixing device are symmetrically distributed. The rod anode retaining ring and rod anode fixing ring can be installed at both ends of the rod anode fixing cover plate, so that the rod anodes can be installed in different directions.

[0067] When inspecting the rod anode, change the installation direction of the rod anode so that the pneumatic toe end of the rod anode fixing device always faces away from the inner wall. This will prevent the rod anode fixing device from interfering with the inner wall when inspecting the edge holes of the steam generator and superheater tube sheet, thus making the inspection impossible.

[0068] It is easy to control. The toes can be fixed and detached from the tube hole by simply controlling the stroke of the lifting cylinder and the lifting rod. The entire inspection tool has two pneumatic toes. The entire tool can be controlled with one hand by two hand-operated two-position three-way pneumatic control valves.

[0069] The tool is easy to install. The entire tool can connect the rod anode fixing device and the film fixing device together through the spring clip on the anode head and the fixing nut on the film plate. The entire device can be operated by a single person by hand and can be remotely controlled during inspection. The operator can stay away from the radiation source and reduce the radiation dose.

[0070] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A steam generator and superheater tube tube sheet weld radiographic inspection apparatus characterized by, The device comprises: a pneumatic telescopic toe (1) for inflation and fixation on the inner wall of the pipe hole of the equipment to be inspected; a rod anode (2) as a radiation source; a rod anode fixing device (3) connecting the pneumatic telescopic toe (1) and the rod anode (2) for fixing and limiting the freedom of the rod anode (2); a film plate (8) for carrying exposed film; and a film plate fixing device (9) connecting the pneumatic telescopic toe (1) and the film plate (8). The pneumatic telescopic toe (1), the rod anode (2), the rod anode fixing device (3), the film plate (8) and the film plate fixing device (9) are connected as a whole, and the anode head (16) of the rod anode (2) can pass through the film hole on the film plate (8) and be inserted into the pipe hole to be inspected.

2. The apparatus of claim 1, wherein, The pneumatic telescopic toe (1) comprises a lifting stroke rod and a claw; the lifting stroke rod is configured to drive the claw to expand for inflation and fixation on the inner wall of the pipe hole when being inflated, and to drive the claw to close for disengagement from the pipe hole when being retracted.

3. The apparatus of claim 1, wherein, The rod anode fixing device (3) comprises: a rod anode fixing bracket (5) in U shape for supporting the main body of the rod anode (2); a rod anode fixing cover plate (4) connected with the rod anode fixing bracket (5) through half connection to fix the main body of the rod anode (2) therebetween; a rod anode fixing ring (6) fixed on the rod anode fixing cover plate (4); and a rod anode holding ring (7) connected with the rod anode fixing ring (6) through half connection for holding the anode head (16) of the rod anode (2).

4. The apparatus of claim 3, wherein, The rod anode fixing cover plate (4) is symmetrical at both ends, and the rod anode fixing ring (6) and the rod anode holding ring (7) can be selectively installed at either end of the rod anode fixing cover plate (4).

5. The apparatus of claim 1, wherein, The film plate fixing device (9) comprises: a film plate fixing plate; a film plate fixing sleeve installed in the fixing hole of the film plate (8) through interference fit and screw-connected with the film plate fixing plate; and a positioning pin (13) installed on the film plate fixing plate for insertion into the pipe hole to limit the rotation of the film plate (8).

6. The apparatus of claim 5, wherein, The film plate (8) is connected with the film plate fixing device (9) through a fixing screw (12).

7. The apparatus of claim 1, wherein, The rod anode (2) comprises a rod anode main body, a cooling air hole opened on the rod anode main body, an anode head (16) and a spring clamping plate (17) arranged on the anode head (16).

8. The apparatus of claim 1, wherein, The film plate (8) comprises a film bottom plate, a film cover plate and a fixing nut (20); The film bottom plate and the film cover plate are used for clamping exposed film and are fixed through the fixing nut (20); The fixing nut (20) is provided with a clamping groove for clamping cooperation with the spring clamping plate (17) on the anode head (16) of the rod anode (2).

9. A method of radiographic examination of steam generator and superheater tube tube sheet welds characterized by, The method is realized based on the device according to any one of claims 1 to 8, and the method comprises: Step 1: installing the film plate (8) on the film plate fixing device (9) and aligning the film hole with the pipe hole to be inspected. Step 2: Insert the pneumatic retractable toes (1) and the positioning pins (13) into the corresponding tube holes, and inflate the toes to fix the device under the tube sheet; Step 3: Fix the rod anode (2) through the rod anode fixing device (3), and insert the anode head (16) into the tube hole to be inspected through the film hole of the film plate (8); Step 4: Remote control the rod anode (2) to expose to radiation; Step 5: After exposure, deflate the toes to remove the device from the tube sheet.

10. The method of claim 9, wherein, When inspecting the edge tube hole, adjust the installation position of the rod anode fixing ring (6) and the rod anode clamping ring (7) in the rod anode fixing device (3) on the rod anode fixing cover plate (4), so that the side where the pneumatic retractable toes (1) are located faces away from the inner wall of the evaporator or superheater, avoiding interference with the inner wall.

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