A discharge pipe repair device and repair method based on dynamic thermal compensation function

Abstract

This invention discloses a discharge pipe repair device and method based on dynamic thermal compensation, comprising a damaged discharge pipe, an intermediate frequency device, a connecting pipe, a sealing structure, and a supporting structure. The upper end of the connecting pipe is connected to the damaged discharge pipe through the sealing structure, and the lower end of the connecting pipe is connected to the intermediate frequency device through the supporting structure. The heating end of the intermediate frequency device is located around the connecting pipe. This invention allows for repair and installation via remote operation, eliminating the need for operators to enter a radioactive environment. The connecting pipe structure features a quick-release design, allowing for replacement in case of failure. The device has a sealing function to prevent leakage of radioactive solidified material from the connection point. The spring support method provides dynamic thermal compensation, effectively supporting the discharge pipe under different thermal expansion conditions. The structure is compact, and the device can be placed in a solidified material container after disassembly, avoiding environmental pollution.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste liquid treatment, and in particular to a discharge pipe repair device and repair method based on dynamic thermal compensation function. Background Technology

[0002] Spent fuel from nuclear power plants primarily follows two routes: single-pass processing and reuse. Spent fuel undergoes reprocessing to extract uranium and plutonium, but this process generates high-level radioactive waste liquid, which contains the majority of the radioactive material from the spent fuel. Due to its high radioactivity, large heat release, and strong toxicity, this fluid high-level radioactive waste liquid poses a significant potential danger to the environment and must be solidified and buried deep underground to protect humans and the environment.

[0003] High-level radioactive waste liquids are mainly treated using vitrification technology. In engineering applications, tank vitrification, ceramic electric furnace vitrification, and cold crucible vitrification are commonly used. The common feature of these technologies is that the glass substrate and the radioactive waste liquid are added to a vitrification furnace, where they are evaporated, stirred, and melted to form a vitrified body. The vitrified body finally flows into a vitrified body container through the discharge pipe at the bottom of the vitrification furnace.

[0004] The discharge pipe is made of high-temperature and corrosion-resistant stainless steel and is usually equipped with an intermediate frequency coil on the outside. Before discharge, the discharge pipe is heated by the intermediate frequency coil to melt the glass in the flow channel, and the solidified body in the furnace flows out through the discharge pipe. After the solidified body container receives the predetermined weight of solidified body, the intermediate frequency coil is turned off, the glass in the flow channel cools and solidifies, and the solidified body in the furnace stops flowing out.

[0005] Due to crystallization and other reasons, modified glass gradually adheres to and accumulates on the inner wall of the discharge pipe. Modified glass usually requires a high temperature to melt, and in this case, the discharge can usually be achieved by increasing the medium-frequency power. The solidified glass has a certain degree of corrosion on the discharge pipe. In addition, during the furnace production process, the discharge pipe is repeatedly heated and cooled, which leads to fatigue and even damage.

[0006] The discharge pipe is a critical component of the furnace; damage to it will render the furnace unusable. The discharge pipe is fixed to the ceramic bricks at the bottom of the furnace and cannot be removed for replacement to prevent leaks. Replacing the entire furnace would require significant capital, be expensive, and have a lengthy processing time. Summary of the Invention

[0007] The purpose of this invention is to provide a discharge pipe repair device and method based on dynamic thermal compensation. It can be installed on a damaged discharge pipe remotely to restore its function.

[0008] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0009] The present invention includes a damaged discharge pipe, an intermediate frequency device, a connecting pipe, a sealing structure, and a supporting structure. The upper end of the connecting pipe is connected to the damaged discharge pipe through the sealing structure, and the lower end of the connecting pipe is connected to the intermediate frequency device through the supporting structure. The heating end of the intermediate frequency device is located around the connecting pipe.

[0010] The support structure includes a mounting plate and an elastic support. The lower end of the extension pipe is fixedly connected to the mounting plate, and the lower end of the mounting plate is connected to the bottom of the intermediate frequency device through the elastic support.

[0011] The elastic support includes a base plate, a fiberglass pad, a ceramic insulating ring, bolts, a shaped screw, and a spring. The base plate, the fiberglass pad, and the ceramic insulating ring are stacked from bottom to top and fixedly connected by the bolts. The shaped screw has a shoulder in the middle and threads at both ends. The lower end of the shaped screw is fixedly connected to the upper end of the ceramic insulating ring by the threads. The spring is fitted onto the shaped screw, with the lower end of the spring contacting the shoulder of the shaped screw and the upper end of the spring contacting the lower end face of the mounting plate. The upper end of the shaped screw passes through the mounting plate and is movable. After passing through the mounting plate, the shaped screw is connected to a nut. The base plate, the fiberglass pad, and the ceramic insulating ring are fixedly installed at the bottom of the intermediate frequency device.

[0012] The sealing structure includes a bottom sealing structure and a side sealing structure. Both the bottom sealing structure and the side sealing structure are disposed inside the upper end of the connecting pipe. The lower end of the damaged discharge pipe is in contact with the bottom sealing structure, and the outer side of the lower end of the damaged discharge pipe is connected to the inner wall of the connecting pipe through the side sealing structure.

[0013] The side sealing structure includes a side aluminum ring, a side copper ring, and a side nickel ring. The upper inner wall of the base plate is provided with a groove. The side aluminum ring, the side copper ring, and the side nickel ring are all overlapped and arranged in the groove on the upper inner wall of the connecting pipe. The connecting pipe, the side aluminum ring, and the side copper ring are arranged between the outer wall of the damaged discharge pipe and the inner wall of the connecting pipe.

[0014] The bottom sealing structure includes a first bottom copper ring, a first bottom aluminum ring, a second bottom aluminum ring, and a second bottom copper ring. The first bottom copper ring and the first bottom aluminum ring have the same inner and outer diameters. The thickness of the first bottom copper ring is greater than the thickness of the first bottom aluminum ring. Two grooves are provided on the upper inner end face of the connecting pipe, which are divided into an inner groove and an outer groove. The first bottom copper ring and the first bottom aluminum ring are located in the outer groove, the second bottom copper ring is located in the inner groove, and the second bottom aluminum ring is located above the outer groove. The second bottom aluminum ring is located between the lower end face of the damaged discharge pipe and the connecting pipe.

[0015] The method for repairing a storage pipe using the discharge pipe repair device based on dynamic thermal compensation includes the following steps:

[0016] Step 1: Assemble the connecting pipe, sealing structure, and support structure;

[0017] Step 2: Weld a support ring to the bottom of the intermediate frequency device, and place the lower end of the support structure on the support ring inside the assembly device;

[0018] Step 3: Cut and grind the lower end of the damaged discharge pipe until the end face is flush, connect the extension pipe to the lower end of the damaged discharge pipe, and fix the intermediate frequency device to complete the repair.

[0019] The beneficial effects of this invention are:

[0020] This invention relates to a discharge pipe repair device and method based on dynamic thermal compensation. Compared with the prior art, this invention has the following technical advantages:

[0021] 1. The device can be repaired and installed remotely, allowing operators to complete installation and repair work without entering the radioactive environment; 2. The connecting pipe structure adopts a quick-release design, and the connecting pipe can be replaced if it fails; 3. The device has a sealing function to prevent leakage of radioactive solidified material from the connection point; 4. The spring support method has a dynamic thermal compensation function, which is effectively applicable to the support of the discharge pipe under different thermal expansion conditions; 5. The structure is compact, and the device can be placed in the solidified material container after disassembly to avoid environmental pollution. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0024] Figure 3 This is a schematic diagram of the upper sealing structure of the present invention;

[0025] Figure 4 This is a schematic diagram of the present invention being connected to the damaged pipe;

[0026] Figure 5 This is a schematic cross-sectional view of the present invention assembled with the intermediate frequency device;

[0027] Figure 6 This is a schematic diagram of the external structure of the present invention and the intermediate frequency device.

[0028] In the diagram: 1. Base plate; 2. Fiberglass pad; 3. Ceramic insulating ring; 4. Bolt; 5. Mounting plate; 6. Special-shaped screw; 7. Extension pipe; 8. Side aluminum ring; 9. Side copper ring; 10. Side nickel ring; 11. First bottom copper ring; 12. First bottom aluminum ring; 13. Second bottom aluminum ring; 14. Second bottom copper ring; 15. Spring; 16. Damaged discharge pipe. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0030] like Figure 1-5 As shown: This invention includes a damaged discharge pipe 16, an intermediate frequency device, a connecting pipe 7, a sealing structure, and a supporting structure. The upper end of the connecting pipe 7 is connected to the damaged discharge pipe 16 through the sealing structure, and the lower end of the connecting pipe 7 is connected to the intermediate frequency device through the supporting structure. The heating end of the intermediate frequency device is located around the connecting pipe 7. The device of this invention can operate under high temperature conditions. The connecting pipe is used to connect to the discharge pipe and restore the function of the discharge pipe before it was damaged. There is a sealing structure and sealing material above the connecting pipe. The connecting pipe is installed on the supporting structure, which has a dynamic thermal compensation function to ensure support after the connecting pipe expands due to heat. There is an insulating structure at the lower end of the supporting structure for insulating the connecting pipe from the external intermediate frequency device. The connecting pipe (7) is a hollow structure, and its inner hole is aligned with the inner hole of the damaged discharge pipe to form a glass-cured body flow channel.

[0031] The support structure includes a mounting plate 5 and an elastic support. The lower end of the extension pipe 7 is fixedly connected to the mounting plate 5, and the lower end of the mounting plate 5 is connected to the bottom of the intermediate frequency device through the elastic support. The lower end of the extension pipe (7) can be connected to the upper end of the mounting plate (5) through three legs, and the liquid flow can be observed through the gap between the legs. The support structure has a dynamic thermal compensation function. After the discharge pipe and extension pipe are heated and stretched, the compressed spring (15) can still support the extension pipe (7).

[0032] The elastic support includes a base plate 1, a fiberglass pad 2, a ceramic insulating ring 3, bolts 4, a special-shaped screw 6, and springs 15. The base plate 1, the fiberglass pad 2, and the ceramic insulating ring 3 are stacked from bottom to top and fixedly connected by bolts 4. The special-shaped screw 6 has a shoulder in the middle and threads at both ends. The lower end of the special-shaped screw 6 is fixedly connected to the upper end of the ceramic insulating ring 3 by threads. The spring is fitted onto the special-shaped screw 6. The lower end of the spring contacts the shoulder of the special-shaped screw 6, and the upper end of the spring contacts the lower end face of the mounting plate 5. The upper end of the special-shaped screw 6 passes through the mounting plate 5 and is movable. After passing through the mounting plate 5, the special-shaped screw 6 is connected to a nut. The base plate 1, the fiberglass pad 2, and the ceramic insulating ring 3 are fixedly installed at the bottom of the intermediate frequency device. There are three springs (15) evenly distributed at 120° to ensure uniform load distribution.

[0033] The sealing structure includes a bottom sealing structure and a side sealing structure. Both the bottom sealing structure and the side sealing structure are disposed inside the upper end of the connecting pipe 7. The lower end of the damaged discharge pipe 16 is in contact with the bottom sealing structure, and the outer side of the lower end of the damaged discharge pipe 16 is connected to the inner wall of the connecting pipe 7 through the side sealing structure.

[0034] The side sealing structure includes a side aluminum ring 8, a side copper ring 9, and a side nickel ring 10. The upper inner wall of the base plate 1 is provided with a groove. The side aluminum ring 8, the side copper ring 9, and the side nickel ring 10 are all overlapped and arranged in the groove on the upper inner wall of the connecting pipe 7. The connecting pipe 7, the side aluminum ring 8, and the side copper ring 9 are arranged between the outer wall of the damaged discharge pipe 16 and the inner wall of the connecting pipe 7.

[0035] The bottom sealing structure includes a first bottom copper ring 11, a first bottom aluminum ring 12, a second bottom aluminum ring 13, and a second bottom copper ring 14. The first bottom copper ring 11 and the first bottom aluminum ring 12 have the same inner and outer diameters. The thickness of the first bottom copper ring 11 is greater than the thickness of the first bottom aluminum ring 12. Two grooves are provided on the upper inner end face of the connecting pipe 7, which are divided into an inner groove and an outer groove. The first bottom copper ring 11 and the first bottom aluminum ring 12 are located in the outer groove, the second bottom copper ring 14 is located in the inner groove, and the second bottom aluminum ring 13 is located above the outer groove. The second bottom aluminum ring 13 is located between the lower end face of the damaged discharge pipe 16 and the connecting pipe 7.

[0036] The method for repairing a storage pipe using the discharge pipe repair device based on dynamic thermal compensation includes the following steps:

[0037] Step 1: Assemble the extension pipe 7, sealing structure, and support structure: Place the fiberglass pad on the base plate, place the ceramic insulating ring on the fiberglass pad, and fix the ceramic insulating ring to the base plate with bolts. Pass the lower ends of the three shaped screws through the ceramic insulating ring and fix them with nuts. Thread the three springs onto the shaped screws respectively. Align the three through holes of the mounting plate with the shaped screws, place the plate on the springs, and fix the mounting plate to the shaped screws with nuts. Place the extension pipe in the slot of the mounting plate, and install the copper ring, aluminum ring, and nickel ring on the top of the extension pipe.

[0038] Step 2: Weld a support ring to the bottom of the intermediate frequency device, and place the lower end of the support structure on the support ring inside the assembly device;

[0039] Step 3: Cut and grind the lower end of the damaged discharge pipe 16 until the end face is flush. Connect the extension pipe 7 to the lower end of the damaged discharge pipe 16 and fix the intermediate frequency device to complete the repair. Transfer the connected repair device and intermediate frequency device to the bottom of the discharge pipe using the transfer device. Operate the transfer device to lift the repair device and intermediate frequency device, so that the extension pipe connects to the damaged pipe. Fix the intermediate frequency device and repair device under the furnace through remote operation and connect the power supply and water supply pipes. Start the intermediate frequency device and adjust the power to 2-5kW, maintain it for 10-15 minutes; increase the intermediate frequency power by 2-3kW each time until the intermediate frequency power is 20kW. After each increase in intermediate frequency power, continue to run for 15-20 minutes.

[0040] After the furnace reaches the discharge level, start the intermediate frequency device and gradually increase the power to 22kW at a rate of 5kW / 15min-5kW / 20min. When the discharge rate exceeds 200kg / h, reduce the intermediate frequency power by 3-12kW to control the rate at 120-150kg / h. After reaching the stop discharge rate, shut down the intermediate frequency device.

[0041] High-temperature testing of the device:

[0042] The device underwent a high-temperature test. Glass was added until the liquid level exceeded the joint. After confirming that the glass had melted, the temperature of the device was further increased to 1050℃, and a pressure test was performed. Argon pressure was tested for 10 minutes at 0.03MPa, 0.04MPa, and 0.05MPa respectively. There were no leaks at the joints of the device, and the device structure was stable, without deformation or damage.

[0043] Device life test:

[0044] A total of 35 life tests were conducted.

[0045] Among them, 29 tests were conducted by heating the splicing device to a maximum temperature of 1180℃ and the temperature at the joint to 760℃, maintaining argon gas at 0.05MPa, and holding the pressure for 1 hour.

[0046] One of the tests involved heating the splicing device to a maximum temperature of 1205℃ and a joint temperature of 770℃ for 6 hours.

[0047] Five of the tests involved heating the splicing device to a maximum temperature of 1200℃, heating the joint temperature to 780℃, maintaining argon gas at 0.05MPa, and holding the pressure for 3 hours.

[0048] No leakage occurred at the sealing joint during heating and cooling; after the device cooled to room temperature, the spring returned to its initial state without plastic deformation; the entire splicing device showed no abnormal deformation, and the device was stable and reliable.

[0049] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A discharge pipe repair device based on dynamic thermal compensation function, comprising a damaged discharge pipe (16) and a medium frequency device, characterized in that: It includes a connecting pipe (7), a sealing structure and a supporting structure. The upper end of the connecting pipe (7) is connected to the damaged discharge pipe (16) through the sealing structure, and the lower end of the connecting pipe (7) is connected to the intermediate frequency device through the supporting structure. The heating end of the intermediate frequency device is located on the periphery of the connecting pipe (7). The support structure includes a mounting plate (5) and an elastic support. The lower end of the extension pipe (7) is fixedly connected to the mounting plate (5). The extension pipe (7) is placed in the slot of the mounting plate (5). The lower end of the mounting plate (5) is connected to the bottom of the intermediate frequency device through the elastic support. The elastic support includes a base plate (1), a fiberglass pad (2), a ceramic insulating ring (3), bolts (4), shaped screws (6), and a spring (15). The base plate (1), the fiberglass pad (2), and the ceramic insulating ring (3) are stacked from bottom to top. The base plate (1), the fiberglass pad (2), and the ceramic insulating ring (3) are fixedly connected by the bolts (4). The shaped screw (6) has a shoulder in the middle and threads at both ends. The lower end of the shaped screw (6) is fixedly connected to the upper end of the ceramic insulating ring (3) by threads. The lower ends of the three shaped screws (6) pass through... The ceramic insulating ring (3) is fixed by a nut. The springs are respectively fitted onto the shaped screw (6). The lower end of the spring contacts the shoulder of the shaped screw (6). The upper end of the spring contacts the lower end face of the mounting plate (5). The three through holes of the mounting plate (5) are aligned with the shaped screw (6). The upper end of the shaped screw (6) passes through the mounting plate (5) and can move. The shaped screw (6) is connected to the nut after passing through the mounting plate (5). The base plate (1), glass fiber pad (2), and ceramic insulating ring (3) are fixedly set at the bottom of the intermediate frequency device. The sealing structure includes a bottom sealing structure and a side sealing structure. Both the bottom sealing structure and the side sealing structure are located inside the upper end of the connecting pipe (7). The lower end of the damaged discharge pipe (16) is in contact with the bottom sealing structure. The outer side of the lower end of the damaged discharge pipe (16) is connected to the inner wall of the connecting pipe (7) through the side sealing structure. The side sealing structure includes a side aluminum ring (8), a side copper ring (9) and a side nickel ring (10), and the side aluminum ring (8), side copper ring (9) and side nickel ring (10) are all overlapped and arranged in the groove of the upper inner wall of the connecting pipe (7).

2. The discharge pipe repair device based on dynamic thermal compensation function according to claim 1, characterized in that: The bottom sealing structure includes a first bottom copper ring (11), a first bottom aluminum ring (12), a second bottom aluminum ring (13), and a second bottom copper ring (14). The first bottom copper ring (11) and the first bottom aluminum ring (12) have the same inner and outer diameters. The thickness of the first bottom copper ring (11) is greater than the thickness of the first bottom aluminum ring (12). The upper inner end face of the connecting pipe (7) is provided with two grooves, namely an inner groove and an outer groove. The first bottom copper ring (11) and the first bottom aluminum ring (12) are located in the outer groove. The second bottom copper ring (14) is located in the inner groove. The second bottom aluminum ring (13) is located above the outer groove. The second bottom aluminum ring (13) is located between the lower end face of the damaged discharge pipe (16) and the connecting pipe (7).

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