Embedded inverted-U-shaped exhaust pipe for nuclear power plant
By installing an anti-corrosion layer and a non-metallic layer on the inner wall of the inverted U-shaped exhaust pipe pre-embedded in nuclear power plants, and by adopting an inner lining inversion process and an edge-wrapping structure, the corrosion problem of the exhaust pipe was solved, the corrosion resistance and sealing performance were improved, the manufacturing cost and process complexity were reduced, and the system safety was ensured.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-03-10
AI Technical Summary
Due to their unique structural limitations, the inverted U-shaped exhaust pipes pre-buried in nuclear power plants cannot be effectively treated by conventional anti-corrosion methods, resulting in a high risk of internal wall corrosion. The shedding of rust products affects system safety and equipment reliability.
An anti-corrosion layer and a non-metallic layer are installed on the inner wall of the exhaust pipe, and an inner lining flipping process and an edge wrapping structure are adopted, combined with sealant to form a dense anti-corrosion structure.
It improves the corrosion resistance and sealing performance of the exhaust pipe, reduces manufacturing costs and process complexity, extends service life, avoids the need for excavation or pipe cutting, and ensures system safety.
Smart Images
Figure CN223986431U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of nuclear power technology, specifically to a pre-embedded inverted U-shaped exhaust pipe for nuclear power plants. Background Technology
[0002] Nuclear power plants typically install inverted U-shaped exhaust pipes on the upper part of large tanks and pools to ensure that the tanks and pools are connected to the external atmosphere and to maintain atmospheric pressure inside the tanks and pools.
[0003] Inverted U-shaped exhaust pipes are generally made of carbon steel with an external coating but no internal corrosion protection. Because these pipes connect to the tanks and pools, the internal humidity is high, leading to a high risk of internal corrosion. Based on operational experience, several inverted U-shaped pipes at a certain nuclear power plant have experienced severe corrosion. Corrosion not only affects the pipe's strength, but the rust products can also detach and enter the tanks or pools, potentially forming foreign objects and impacting system safety. Furthermore, the detached rust products can affect the water quality within the containers. Therefore, corrosion of inverted U-shaped exhaust pipes is a common and critical issue in nuclear power plants, significantly impacting equipment reliability and safety.
[0004] The inner walls of general pipelines have various anti-corrosion methods, such as coatings, plastic linings, and rubber linings. However, due to the special structural limitations of pre-embedded inverted U-shaped exhaust pipes (limited space in the pipeline location and inaccessible bends, etc.), conventional surface treatment measures, such as sandblasting or manual grinding, cannot effectively treat the surface. Utility Model Content
[0005] In view of the problems existing in the prior art, this utility model proposes a pre-embedded inverted U-shaped exhaust pipe for nuclear power plants.
[0006] To achieve the above objectives, the technical solution of this utility model is as follows: a pre-embedded inverted U-shaped exhaust pipe for nuclear power plants, comprising an inverted U-shaped pipe body, an anti-corrosion layer disposed on the inner wall of the pipe body, and a non-metallic layer disposed on the inner wall of the anti-corrosion layer.
[0007] Furthermore, it is preferable that the non-metallic layer is a flexible tube impregnated with synthetic resin.
[0008] Furthermore, it is preferable that the hose is installed on the inner wall of the tube using an inner lining inverting process.
[0009] Furthermore, preferably, at least one end of the tube is provided with a sealing structure, the sealing structure extending from the inner wall surface of the tube to the outer wall surface, and the sealing structure is sealed between the sealing structure and the inner wall surface and the outer wall surface of the tube.
[0010] Furthermore, it is preferable that the extension distance of the edging structure from the port of the tube to the outermost end of the outer wall is 5-10cm.
[0011] Furthermore, it is preferable that both ends of the tube body are provided with a edging structure.
[0012] Furthermore, it is preferable that the edge-sealing structure and the outer wall surface of the tube are sealed with a sealant layer.
[0013] Furthermore, the anti-corrosion layer is preferably a dense oxide layer.
[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: The nuclear power plant pre-embedded inverted U-shaped exhaust pipe of this utility model improves its corrosion resistance by setting a non-metallic layer and an anti-corrosion layer; at the same time, the non-metallic layer is set by using an inner lining flipping process, which reduces manufacturing costs and process complexity; in addition, by setting an edge wrapping structure and using sealant, the sealing performance and service life of the exhaust pipe are further improved. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a schematic diagram of the structure of the nuclear power plant pre-embedded inverted U-shaped exhaust pipe in this utility model;
[0017] Figure 2 This is a schematic diagram of the process of flipping the non-metallic layer 30 inner lining of the nuclear power plant pre-embedded inverted U-shaped exhaust pipe in this utility model.
[0018] Figure 3 This is a schematic diagram of another embodiment of the nuclear power plant pre-embedded inverted U-shaped exhaust pipe in this utility model;
[0019] Figure 4 This is a schematic diagram of the edging structure of the inverted U-shaped exhaust pipe pre-embedded in nuclear power plants in this utility model. Detailed Implementation
[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0021] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.
[0022] Furthermore, in this utility model, the use of terms such as "first," "second," etc., is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0023] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0024] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0025] This utility model provides a pre-embedded inverted U-shaped exhaust pipe for nuclear power plants, such as Figures 1-4 As shown, it includes an inverted U-shaped pipe body 10, an anti-corrosion layer 20 disposed on the inner wall of the pipe body 10, and a non-metallic layer 30 disposed on the inner wall of the anti-corrosion layer 20. The pipe body 10 of the inverted U-shaped exhaust pipe includes a curved section and a straight section. The curved section can be exposed on the ground, and the straight section extends underground through the concrete layer 100.
[0026] In the above technical solution, the inverted U-shaped pipe body 10 serves as the main structure of the exhaust pipe, and its shape and size are designed according to actual needs. The anti-corrosion layer 20 can be made of various anti-corrosion coatings, anti-corrosion films, etc. The anti-corrosion layer 20 is set on the inner wall of the pipe body 10 to further improve the corrosion resistance of the exhaust pipe. The non-metallic layer 30 is set on the inner wall of the anti-corrosion layer 20 to isolate the pipe body 10 from direct contact with the medium, thereby reducing corrosion. The non-metallic layer 30 can be made of various corrosion-resistant materials, such as plastics, rubber, etc.
[0027] In one specific embodiment, the non-metallic layer 30 is a flexible tube impregnated with synthetic resin. In the above technical solution, the non-metallic layer 30 is a flexible tube impregnated with synthetic resin. Synthetic resin has good corrosion resistance and flexibility, effectively protecting the metal tube 10 from corrosion. Simultaneously, the flexible tube design allows the non-metallic layer 30 to adhere tightly to the inner wall of the tube 10, preventing it from easily falling off.
[0028] In one specific embodiment, such as Figure 2 As shown, the hose is installed on the inner wall of the tube body 10 using an inner lining inversion process. This process ensures the hose adheres evenly to the inner wall of the tube body 10, minimizing the formation of air bubbles and wrinkles, thereby improving the sealing and corrosion resistance of the non-metallic layer 30.
[0029] In one specific embodiment, such as Figures 3-4 As shown, at least one end of the pipe body 10 is provided with a sealing structure 40. The sealing structure 40 extends from the inner wall surface of the pipe body 10 to the outer wall surface, and the sealing structure 40 is sealed to both the inner and outer wall surfaces of the pipe body 10. In the above technical solution, at least one end of the pipe body 10 is provided with a sealing structure 40, which extends from the inner wall surface of the pipe body 10 to the outer wall surface, forming a seal with both the inner and outer wall surfaces of the pipe body 10. The sealing structure 40 can enhance the strength and sealing performance of the end of the pipe body 10, preventing the medium from leaking from the end of the pipe body 10. At the same time, the sealing structure 40 can also protect the non-metallic layer 30 and the anti-corrosion layer 20, extending the service life of the exhaust pipe.
[0030] In one specific embodiment, the extension distance of the edging structure 40 from the port of the tube 10 to the outermost end of the outer wall is 5-10 cm. In the above technical solution, the extension distance of the edging structure 40 from the port of the tube 10 to the outermost end of the outer wall is 5-10 cm. This distance can ensure the strength and sealing of the edging structure 40, and can also avoid material waste and increased processing difficulty caused by excessive extension.
[0031] In one specific embodiment, both ends of the pipe body 10 are provided with a sealing structure 40. This ensures that the exhaust pipe is well sealed and protected at both ends, further improving its corrosion resistance and service life.
[0032] In one specific embodiment, a sealant layer is used to seal the edge-sealing structure 40 with the outer wall of the pipe body 10. This further improves the sealing performance of the exhaust pipe and prevents the medium from leaking from the gap between the edge-sealing structure 40 and the outer wall of the pipe body 10.
[0033] In one specific embodiment, the anti-corrosion layer 20 is a dense oxide layer. The dense oxide layer has good corrosion resistance and adhesion, effectively protecting the metal pipe body 10 from corrosion. Furthermore, the preparation process of the dense oxide layer is relatively simple, low-cost, and easy to mass-produce.
[0034] This embodiment provides a method for manufacturing a pre-embedded inverted U-shaped exhaust pipe for a nuclear power plant, the method comprising the following steps:
[0035] Step 1: Prepare an inverted U-shaped tube. Design the shape and size of the tube according to actual needs.
[0036] Step 2: Prepare a dense oxide layer on the inner wall of the pipe to form an anti-corrosion layer. Alternatively, the pipe can be a used and rusted one. In this case, first use a sandblasting gun to preliminarily sandblast the inside of the pipe from one direction to remove large pieces of loose corrosion products from the inner wall. After sandblasting, use compressed air to purge the inside of the pipe. Install a cover plate to seal the pipe opening on one side, and install a cover plate with a conduit on the other side. Connect the conduit to the press and pressurize it, allowing the rust converter (or corrosion inhibitor if it's a new pipe) to fill the inside of the pipe. Maintain the pressure for a period of time, such as 10 hours, to allow the rust converter to fully react with the rust on the pipe surface, forming an anti-corrosion layer. After pressurizing, disconnect the press and remove the cover plates at both ends of the pipe. Collect any remaining rust converter residue from the pipe and dispose of it properly. Finally, use compressed air to thoroughly dry the inside of the pipe.
[0037] Step 3: Using an inner lining inversion process, the hose impregnated with synthetic resin is attached to the inner wall of the tube to form a non-metallic layer: After folding the hose impregnated with synthetic resin, it is inserted into one end of the tube and then compressed air is passed through that end. Under the action of compressed air, the folded part of the hose is continuously unfolded along the tube until the hose extends beyond the other end.
[0038] Step 4: Trim both ends of the tube, ensuring the hose extends 5-10cm beyond the tube opening. Immediately after trimming, fold the excess hose along the opening to form a ferrule at the tube end, extending from the inner wall to the outer wall and creating a seal between them. Allow the hose to stand and cure to allow the synthetic resin to fully harden.
[0039] Step 5: After the hose has cured, use sealant to seal the flange to ensure that moisture cannot seep into the space between the plastic-coated tube and the hose through the flange.
[0040] By following the above steps, the inverted U-shaped exhaust pipe for nuclear power plants of this utility model can be manufactured.
[0041] Due to the unique structural limitations of the pre-embedded inverted U-shaped exhaust pipe (limited space and inaccessible bends), conventional surface treatment methods, such as sandblasting or manual grinding, are ineffective. Furthermore, conventional anti-corrosion processes require thorough surface preparation. Therefore, current technologies cannot achieve effective anti-corrosion treatment without excavating or cutting the pipe. Excavating or cutting the pipe would render the system unusable, impacting the nuclear power unit's power generation capacity and safety.
[0042] This utility model patent enables in-situ repair without excavation or cutting of the pipeline. After repair, it can completely avoid corrosion and ensure that the anti-corrosion layer has no risk of peeling off, unlike general coating anti-corrosion processes.
[0043] Taking the maintenance of the exhaust pipe of the fire-fighting water tank in a nuclear power plant as an example, if conventional methods are used, the power plant needs to excavate about 1 meter of concrete, with an expected construction period of 10 days. During this period, the availability of fire protection will be affected, posing certain fire hazards. Moreover, the excavation may affect the overall structure of the concrete. However, using this technology, the repair work can be completed in 3 days without excavation, greatly optimizing the maintenance process.
[0044] Compared with the prior art, the beneficial effects of this utility model are as follows: The nuclear power plant pre-embedded inverted U-shaped exhaust pipe of this utility model improves its corrosion resistance by setting a non-metallic layer and an anti-corrosion layer; at the same time, the non-metallic layer is set by using an inner lining flipping process, which reduces manufacturing costs and process complexity; in addition, by setting an edge wrapping structure and using sealant, the sealing performance and service life of the exhaust pipe are further improved.
[0045] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A nuclear power plant embedded inverted U-shaped exhaust pipe, characterized in that, The pipe body comprises a reverse U-shaped pipe body, an anticorrosive layer arranged on the inner wall of the pipe body, and a non-metal layer arranged on the inner wall of the anticorrosive layer.
2. The embedded inverted U-shaped exhaust pipe of a nuclear power plant according to claim 1, characterized by, The non-metal layer is a hose soaked with synthetic resin.
3. The embedded inverted U-shaped exhaust pipe of a nuclear power plant according to claim 2, characterized by, The hose is arranged on the inner wall of the pipe body by using an inner lining inversion process.
4. The embedded inverted U-shaped exhaust pipe of a nuclear power plant according to claim 1, characterized by, At least one end of the pipe body is provided with a hem structure, the hem structure is arranged from the inner wall to the outer wall of the pipe body, and the hem structure is sealed between the inner wall and the outer wall of the pipe body.
5. The embedded inverted U-shaped exhaust pipe of a nuclear power plant according to claim 4, wherein The extension distance of the hem structure from the port to the outermost end of the outer wall of the pipe body is 5-10 cm.
6. The embedded inverted U-shaped exhaust pipe of a nuclear power plant according to claim 4, characterized by, Both ends of the pipe body are provided with a hem structure.
7. The embedded inverted U-shaped exhaust pipe of the nuclear power plant according to claim 4, characterized in that, The hem structure is sealed between the outer wall of the pipe body by using a sealant layer.
8. The embedded inverted U-shaped exhaust pipe of a nuclear power plant according to claim 1, characterized by, The anticorrosive layer is a dense oxide layer.