Pipeline, forming method of pipeline and cooling water system of nuclear power plant

Abstract

The invention relates to the technical field of pipelines, and provides a pipeline, a pipeline forming method and a nuclear power plant cooling water system.The pipeline comprises a pipe body and a lining structure, and a mortar layer is arranged on the inner wall of the pipe body; the lining structure comprises a first resin layer and a second resin layer, and the first resin layer is arranged on the side, opposite to the inner wall of the pipe body, of the mortar layer and used for isolating and sealing the mortar layer; the second resin layer is arranged on the side, opposite to the mortar layer, of the first resin layer and used for isolating and sealing the first resin layer. The lining structure can be prevented from generating a large number of pinholes or bubbling defects, the quality of the lining structure is effectively improved, a seawater medium and a pipeline are effectively isolated, the corrosion phenomenon of the pipeline is reduced, and therefore the durability of the pipeline is improved, and the service life of the pipeline is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of pipelines, and in particular provides a pipeline, a pipeline forming method and a cooling water system for a nuclear power plant. Background Art

[0002] At present, the cooling water system of nuclear power plants uses steel cylinder concrete pipes as cooling water delivery pipes. The structure of the steel cylinder concrete pipe is a thin steel plate pipe body in the middle, the outer wall of the pipe body is a reinforced concrete structure, and the inner wall of the pipe body is a mortar layer composed of cement mortar. The mortar layer mainly performs the anti-corrosion function. However, when the steel cylinder concrete pipe is used as a seawater water pipeline for a long time, the chloride ions in the seawater will penetrate the inner wall mortar layer under the action of infiltration, causing serious corrosion to the steel plate, steel bars and other components of the pipeline. The corrosion products further crack the mortar layer and reinforced concrete structure. After corrosion to a certain extent, the pipeline will leak or rupture, reducing the reliability of the pipeline and bringing very high safety risks to the normal operation of the system. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a pipeline, a pipeline forming method and a nuclear power plant cooling water system, aiming to solve the corrosion problem of existing steel cylinder concrete pipelines caused by chloride ion penetration when transporting seawater for a long time.

[0004] To achieve the above purpose, the technical solution adopted in this application is:

[0005] The present application provides a pipeline, the pipeline comprising a pipe body, the inner wall of the pipe body is provided with a mortar layer, and the pipeline further comprises:

[0006] The lining structure includes a first resin layer and a second resin layer. The first resin layer is arranged on the side of the mortar layer facing away from the inner wall of the tube body, and is used to isolate and seal the mortar layer; the second resin layer is arranged on the side of the first resin layer facing away from the mortar layer, and is used to isolate and seal the first resin layer.

[0007] The pipeline provided by the present application introduces a paste-like first resin layer as an isolation and sealing layer on the surface of the mortar layer on the inner wall of the pipeline. When the first resin layer is cured, the moisture and air cavity in the mortar layer on the inner wall of the pipeline can be isolated and sealed. In this way, during the rapid curing process of the second resin layer, although heat is still released, the water vapor generated by the moisture in the mortar layer on the inner wall of the pipeline under the action of heat cannot penetrate the first resin layer in a short time due to the isolation and sealing blocking effect of the first resin layer, thereby ensuring that the second resin layer is completely cured, avoiding the generation of a large number of pinholes or bubbles in the lining structure, effectively improving the quality of the lining structure, achieving effective isolation between the seawater medium and the pipeline, reducing pipeline corrosion, and thereby improving the durability of the pipeline and extending its service life.

[0008] Optionally, the first resin layer is bonded to the mortar layer;

[0009] And / or, the second resin layer is bonded to the first resin layer.

[0010] Optionally, the bonding strength between the first resin layer and the mortar layer is greater than 1.5 MPa;

[0011] Alternatively, the bonding strength between the first resin layer and the mortar layer is greater than the cohesive strength of the mortar layer.

[0012] Optionally, the bonding strength between the second resin layer and the first resin layer is greater than 5 MPa;

[0013] Alternatively, the bonding strength between the second resin layer and the first resin layer is greater than the cohesive strength of the mortar layer.

[0014] Optionally, the first resin layer is a high-viscosity resin, and the dynamic viscosity of the high-viscosity resin is between 10 Pa·s and 250 Pa·s.

[0015] Optionally, the thickness of the first resin layer is between 0.2 mm and 1.0 mm;

[0016] And / or, the water vapor permeability of the first resin layer is less than 80g / (m 2 ·24h).

[0017] Optionally, the second resin layer is a polyurethane resin.

[0018] Optionally, the curing time of the second resin layer is between 15s and 45s;

[0019] and / or, the thickness of the second resin layer is between 3.0 mm and 8.0 mm;

[0020] And / or, the bending strength of the second resin layer is greater than 40 MPa.

[0021] The present application also provides a nuclear power plant cooling water system, comprising: the above-mentioned pipeline, wherein the pipeline is used to transport cooling water.

[0022] The nuclear power plant cooling water system provided in the present application can improve the durability and safety of the system through the above-mentioned pipelines.

[0023] The present application also provides a method for forming a pipe, comprising:

[0024] Apply a first liquid resin on the surface of the mortar layer on the inner wall of the pipe body and solidify the first liquid resin to form a first resin layer;

[0025] Spraying a second liquid resin on the surface of the first resin layer facing away from the mortar layer and rapidly curing the surface to form a second resin layer, so as to obtain a pipe with an inner lining structure;

[0026] Wherein, the lining structure includes the first resin layer and the second resin layer.

[0027] The pipe forming method provided in the present application introduces a paste-like first resin layer as an isolation and sealing layer on the surface of the mortar layer on the inner wall of the pipe. When the first resin layer is cured, the moisture and air cavity in the mortar layer on the inner wall of the pipe can be isolated and sealed. In this way, during the rapid curing process of the second resin layer, although heat is still released, the water vapor generated by the moisture in the mortar layer on the inner wall of the pipe under the action of heat cannot penetrate the first resin layer in a short time due to the isolation and sealing blocking effect of the first resin layer, thereby ensuring that the second resin layer is completely cured, avoiding the generation of a large number of pinholes or bubbles in the lining structure, effectively improving the quality of the lining structure, achieving effective isolation between the seawater medium and the pipe, reducing pipe corrosion, and thereby improving the durability of the pipe and extending its service life.

[0028] Optionally, before applying the first liquid resin, the method further comprises:

[0029] The surface of the mortar layer on the inner wall of the tube body is pre-cleaned.

[0030] Optionally, the first liquid resin is a high-viscosity resin, and the dynamic viscosity of the high-viscosity resin is between 10 Pa·s and 250 Pa·s.

[0031] Optionally, the coating thickness of the first liquid resin is between 0.2 mm and 1.0 mm, and when the coating thickness of the first liquid resin is 1.0 mm, the heat generated by the first liquid resin during the curing process causes the temperature of the first resin layer to rise by less than 10°C.

[0032] Optionally, the bonding strength between the first resin layer and the mortar layer is greater than 1.5 MPa, or the bonding strength between the first resin layer and the mortar layer is greater than the cohesive strength of the mortar layer;

[0033] And / or, the water vapor permeability of the first resin layer is less than 80g / (m 2 ·24h).

[0034] Optionally, the second liquid resin is a polyurethane resin.

[0035] Optionally, the curing time of the second liquid resin is between 15s and 45s;

[0036] And / or, the coating thickness of the second liquid resin is between 3.0 mm and 8.0 mm.

[0037] Optionally, the bonding strength between the second resin layer and the first resin layer is greater than 5 MPa, or the bonding strength between the second resin layer and the first resin layer is greater than the cohesive strength of the mortar layer;

[0038] And / or, the bending strength of the second resin layer is greater than 40 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 A schematic diagram of the structure of a pipeline provided in an embodiment of the present application;

[0041] Figure 2 A schematic diagram of a process for forming a pipe provided in an embodiment of the present application;

[0042] Figure 3 A schematic diagram of the surface of the lining structure provided in an embodiment of the present application without adding an isolation sealing layer;

[0043] Figure 4 A schematic diagram of the surface of the lining structure with an additional isolation and sealing layer provided in an embodiment of the present application.

[0044] Among them, the reference numerals in the figure are:

[0045] 1. Pipe body; 2. Lining structure; 3. Mortar layer; 4. First resin layer; 5. Second resin layer;

[0046] 6. Reinforced concrete structure. DETAILED DESCRIPTION

[0047] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0048] In the description of the embodiments of the present application, it needs to be understood that the orientations or positional relationships indicated by the terms "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0050] In the embodiments of the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0051] The present application aims to solve the corrosion problem of steel cylinder concrete pipelines caused by chloride ion penetration when transporting seawater for a long time. The durability and anti-corrosion performance of the pipeline are improved by introducing an inner lining structure 2, i.e., a double-layer resin layer.

[0052] In one embodiment, referring to Figure 1 As shown, the pipe provided in the present application includes a pipe body 1 and an inner lining structure 2. The inner wall of the pipe body 1 is provided with a mortar layer 3; the inner lining structure 2 includes a first resin layer 4 and a second resin layer 5, wherein the first resin layer 4 is provided on the side of the mortar layer 3 facing away from the inner wall of the pipe body 1, and is used to isolate and seal the mortar layer 3; the second resin layer 5 is provided on the side of the first resin layer 4 facing away from the mortar layer 3, and is used to isolate and seal the first resin layer 4.

[0053] In this embodiment, the pipe body 1 may be a thin steel plate, a mortar layer 3 is provided on the inner wall of the pipe body 1, and a reinforced concrete structure 6 is provided on the outer wall of the pipe body 1, thereby forming a steel cylinder concrete pipe.

[0054] In the lining structure 2, the first resin layer 4 is located between the mortar layer 3 and the second resin layer 5, and serves as an isolation and sealing layer to isolate and seal the mortar layer 3. Specifically, after curing, the first resin layer 4 can effectively isolate the moisture and air in the mortar layer 3 and prevent them from penetrating outward, thereby providing a good environment for the curing of the second resin layer 5. In this way, pinholes or bubbling caused by the vaporization of moisture in the mortar layer 3 can be avoided, and the overall quality of the lining structure 2 can be improved.

[0055] The second resin layer 5 covers the first resin layer 4, further providing isolation protection to prevent the transport medium (such as seawater) from contacting the internal structure of the pipeline. Specifically, when the second resin layer 5 is rapidly cured, although heat is generated, due to the presence of the first resin layer (isolation sealing layer), the water vapor generated by the moisture in the mortar layer 3 on the inner wall of the pipeline under the action of heat cannot penetrate the first resin layer 4 in a short time, thereby ensuring that the second resin layer 5 is completely cured without interference, avoiding the generation of a large number of pinholes or bubbling defects, thereby improving the quality of the lining structure 2 and forming a solid protective barrier.

[0056] Reference Figure 3 As shown, if no isolation sealing layer is added and a single resin layer is directly used as the lining structure, since the mortar layer 3 on the inner wall of the pipeline is still in a water-saturated state, ventilation and drying can only reach a surface dry state in a short time and cannot be completely dried. A large amount of heat will be released during the rapid curing reaction of the resin material, causing the temperature of the inner wall of the pipeline to rise rapidly. The moisture in the mortar layer 3 will vaporize under the action of heat, and the generated gas will bulge the lining structure that has not yet hardened, forming a large number of pinholes or bubbling defects on the surface, making it impossible to achieve complete isolation of the seawater medium, thereby failing to achieve the purpose of anti-corrosion and life extension of the pipeline.

[0057] Reference Figure 4 As shown, the present application adds a double-layer resin lining structure with an isolation sealing layer, and the inner wall surface is smooth and defect-free, which can achieve complete isolation of the seawater medium, thereby achieving the purpose of corrosion protection and life extension of the pipeline.

[0058] Therefore, the double-layer resin lining structure of the embodiment of the present application can effectively isolate seawater from the pipeline, reduce the chance of corrosive substances such as chloride ions directly contacting the pipeline, and reduce the risk of corrosion. This design greatly improves the ability of the pipeline to resist seawater erosion and extends the service life of the pipeline.

[0059] In one embodiment, the first resin layer 4 is bonded to the mortar layer 3 .

[0060] Specifically, the first resin layer 4 may be made of a resin material with high reactivity, which can react chemically with the components in the mortar (such as silicate) to form a strong chemical bond. For example, the first resin layer 4 may be epoxy resin.

[0061] When the resin material is coated on the surface of the mortar layer 3, it can penetrate into the tiny pores or cracks on the surface of the mortar, increasing the bonding strength between the two, so that the first resin layer 4 has an excellent isolation and sealing effect after curing, which is beneficial to improving the sealing and stability of the lining structure 2.

[0062] In one embodiment, the second resin layer 5 is bonded to the first resin layer 4 .

[0063] Specifically, when the two layers of resin are tightly combined, it not only enhances the overall rigidity of the lining structure 2, but also better resists external pressure changes and mechanical damage, thereby improving the safety and reliability of the pipeline.

[0064] In one embodiment, the bonding strength between the first resin layer 4 and the mortar layer 3 is greater than 1.5 MPa.

[0065] Specifically, when the bonding strength between the first resin layer 4 and the mortar layer 3 exceeds 1.5 MPa, it means that the bonding force between them is strong enough to withstand considerable shear force and tensile force. This level of bonding strength is essential for improving the isolation and sealing effect of the first resin layer 4, thereby helping to improve the quality of the lining structure 2.

[0066] In one embodiment, the bonding strength between the first resin layer 4 and the mortar layer 3 is greater than the cohesive strength of the mortar layer 3 .

[0067] Specifically, the bonding strength between the first resin layer 4 and the mortar layer 3 is greater than the cohesive strength of the mortar layer 3 itself. When subjected to external force, even if damage occurs, it is mainly the mortar material itself that is damaged, and the integrity of the resin layer and its protective function will not be affected, thereby improving the reliability of the pipeline.

[0068] In one embodiment, the bonding strength between the second resin layer 5 and the first resin layer 4 is greater than 5 MPa.

[0069] Specifically, when the bonding strength between the second resin layer 5 and the first resin layer 4 exceeds 5 MPa, it indicates that the bonding force between them is very strong and can withstand great shear and tensile forces. This high-strength bonding is essential to prevent chloride ions and other corrosive substances in seawater from penetrating.

[0070] In one embodiment, the bonding strength between the second resin layer 5 and the first resin layer 4 is greater than the cohesive strength of the mortar layer 3 .

[0071] Specifically, the bonding strength between the second resin layer 5 and the first resin layer 4 is greater than the cohesive strength of the mortar layer 3 itself. When subjected to external force, even if damage occurs, it is mainly the mortar material itself that is damaged, and the integrity of the double-layer resin lining structure and its protective function will not be affected, thereby improving the reliability of the pipeline.

[0072] In one embodiment, the first resin layer 4 may be a high-viscosity resin, and the dynamic viscosity of the high-viscosity resin is between 10 Pa·s and 250 Pa·s.

[0073] Specifically, the first resin layer 4 is obtained by curing after coating with the first liquid resin. The selected first liquid resin is a high-viscosity resin. During the coating process, the high-viscosity resin has low fluidity, which reduces the possibility of air entrainment, thereby reducing the risk of bubbles and pinholes after curing, and improving the quality of the lining structure 2. In addition, the higher viscosity means that the resin material can form a denser and smoother covering layer on the surface of the mortar layer 3, effectively filling tiny pores and cracks, providing excellent sealing performance, and preventing moisture and chloride ion penetration. In addition, the high-viscosity resin after curing has good mechanical strength and toughness, which helps to resist external pressure changes and mechanical damage, and improves the durability and reliability of the entire lining structure 2.

[0074] In one embodiment, the thickness of the first resin layer 4 is between 0.2 mm and 1.0 mm.

[0075] Specifically, the first resin layer 4 is obtained by coating and curing the first liquid resin, and the coating thickness of the first liquid resin is between 0.2 mm and 1.0 mm, wherein 0.2 mm is the lower limit value, which ensures that the resin material will not be too thin during coating to cause unevenness or defects (such as pinholes), and will not increase the construction difficulty or time due to being too thick; 1.0 mm is the upper limit value, which avoids unnecessary material waste and cost increase while ensuring the protective effect, thereby optimizing the economic benefits.

[0076] The thickness of 0.2 mm to 1.0 mm can ensure that the first resin layer 4 forms an effective barrier and achieves efficient isolation and sealing. And within this thickness range, the resin layer can provide sufficient mechanical strength and toughness after curing to resist external pressure changes and mechanical damage, thereby extending the service life of the pipeline.

[0077] In some examples, when the coating thickness of the first liquid resin is 1.0 mm, that is, the thickness of the first resin layer 4 is 1.0 mm, the heat generated by the first liquid resin during the curing process causes the temperature rise of the first resin layer 4 to be less than 10° C. It can be understood that the thinner the coating thickness of the first liquid resin, the smaller the temperature rise of the first resin layer 4 caused by the heat generated by the first liquid resin during the curing process.

[0078] Specifically, a lower temperature rise can significantly reduce the internal stress caused by thermal expansion and contraction, thereby reducing the risk of cracks or delamination in the resin layer. In addition, a smaller temperature rise helps protect the internal mortar layer 3 from thermal shock, avoiding the rapid evaporation of moisture in the mortar layer 3 to generate steam pressure, thereby preventing the formation of defects such as pinholes or bubbles, thereby improving the integrity and protective performance of the resin layer.

[0079] In one embodiment, the water vapor transmission rate of the first resin layer 4 is less than 80 g / (m 2 ·24h).

[0080] Specifically, a lower water vapor permeability rate helps to improve the isolation and sealing effect, and can block the water vapor generated by the moisture in the mortar layer 3 under the heat of the second resin layer 5 during curing, thereby avoiding the generation of a large number of pinholes or bubbling defects, and improving the quality and sealing of the lining structure 2. In addition, low water permeability can also help maintain the bonding strength between the first resin layer 4 and the mortar layer 3, and prevent delamination or peeling caused by water penetration.

[0081] In some examples, the first resin layer 4 may be a high-strength room-temperature curing resin that remains stable in an alkaline environment and has a volume change rate of less than 10% after being immersed in a 1 mol / L sodium hydroxide solution for 148 hours.

[0082] Specifically, the first resin layer 4 can be a modified epoxy resin, a phenolic resin or other resin, which can remain stable in an alkaline environment, especially when facing a high concentration of sodium hydroxide solution, indicating that the resin material has excellent chemical resistance, which is particularly critical in preventing corrosion from alkaline components (such as carbonates) in seawater.

[0083] After immersion in 1 mol / L sodium hydroxide solution for 148 hours, the volume change rate is less than 10%, indicating that the resin material is not only stable in short-term contact, but also can maintain its physical size under long-term exposure to strong alkaline conditions without significant expansion or contraction, thereby ensuring the integrity and sealing of the lining structure 2.

[0084] In one embodiment, the second resin layer 5 is a polyurethane resin.

[0085] Specifically, the second resin layer 5 is formed by coating the second liquid resin and then rapidly curing it. The selected second liquid resin is a polyurethane resin, which can be rapidly cured in a short time, significantly shortening the construction period and improving work efficiency. In addition, the coating formed by the polyurethane resin can effectively prevent moisture, chloride ions and other corrosive substances in seawater from penetrating into the interior of the pipeline, providing long-term protection for the pipeline. This type of material has good resistance to a variety of chemical substances, including acids, alkalis and salts, and is particularly suitable for seawater transportation environments.

[0086] In addition, the second resin layer 5 has sufficient rigidity to maintain its physical integrity and structural stability even when the bonding strength decreases, and will not be easily damaged or peeled off, thereby ensuring the integrity and reliability of the lining structure 2 and avoiding adverse effects on the function of the process pipeline. This design choice is crucial to ensure the safe and stable operation of the transmission pipeline in the cooling water system of a nuclear power plant.

[0087] In one embodiment, the curing time of the second resin layer 5 is between 15s and 45s.

[0088] Specifically, the second resin layer 5 is obtained by coating the second liquid resin and then rapidly curing it. The curing time of the second liquid resin is between 15s and 45s, which not only improves the construction efficiency, but also ensures that the resin layer is uniformly cured in a short time to form a solid isolation and protective layer, thereby avoiding quality problems caused by uneven curing. Rapid curing helps to reduce defects such as pinholes and bubbles in the coating caused by water evaporation or air entrainment during the curing process, thereby improving the overall quality of the lining structure 2.

[0089] In one embodiment, the thickness of the second resin layer 5 is between 3.0 mm and 8.0 mm.

[0090] Specifically, the second resin layer 5 is obtained by coating the second liquid resin and then rapidly curing it, and the coating thickness of the second liquid resin is between 3.0 mm and 8.0 mm, wherein 3.0 mm is the lower limit, which ensures that the resin material will not be too thin during coating to cause unevenness or defects (such as pinholes), and will not increase the construction difficulty or time due to being too thick; 8.0 mm is the upper limit, which ensures the protective effect while avoiding unnecessary material waste and cost increase, thereby optimizing the economic benefits.

[0091] The thickness of 3.0 mm to 8.0 mm can ensure that the second resin layer 5 forms an effective barrier to prevent chloride ions and other corrosive substances in seawater from penetrating into the interior of the pipeline. Moreover, within this thickness range, the resin layer can provide sufficient mechanical strength and toughness after curing to resist external pressure changes, mechanical damage, and erosion caused by long-term exposure to a corrosive environment, thereby extending the service life of the pipeline.

[0092] In one embodiment, the bending strength of the second resin layer 5 is greater than 40 MPa.

[0093] Specifically, a bending strength greater than 40 MPa indicates that the resin layer has excellent bending resistance and can effectively prevent breakage or permanent deformation when subjected to external pressure or impact. High bending strength helps extend the service life of the pipeline and reduce maintenance requirements and costs caused by mechanical damage.

[0094] Even under extreme conditions, such as temperature fluctuations or long-term exposure to corrosive environments, the resin layer with high flexural strength can still maintain its physical size and shape and will not easily expand or shrink. Good flexural strength also means that the bond between the resin layer and the underlying material is stronger, reducing the risk of delamination or peeling, thereby ensuring the integrity and sealing of the entire lining structure 2.

[0095] In one embodiment, the present application also provides a cooling water system for a nuclear power plant, including: the pipeline of the above embodiment, the pipeline is used to transport cooling water.

[0096] The nuclear power plant cooling water system provided in the embodiment of the present application can improve the durability and safety of the system through the pipelines of the above embodiment.

[0097] In one embodiment, referring to Figure 2 As shown, the present application also provides a method for forming a pipe, comprising the following steps:

[0098] S201, applying a first liquid resin on the surface of the mortar layer 3 on the inner wall of the tube body 1 and curing the resin to form a first resin layer 4;

[0099] S202, spraying a second liquid resin on the surface of the first resin layer 4 facing away from the mortar layer 3 and rapidly curing the surface to form a second resin layer 5, so as to obtain a pipeline having an inner lining structure 2;

[0100] The lining structure 2 includes a first resin layer 4 and a second resin layer 5 .

[0101] In this embodiment, a layer of paste-like first liquid resin is evenly scraped on the surface of the mortar layer 3 on the inner wall of the pipe body 1 and cured to form a first resin layer 4 to isolate and seal the moisture and air cavity in the mortar layer 3. In this way, during the subsequent rapid curing process of the second resin layer 5, although heat is still released, due to the isolation and sealing blocking effect of the first resin layer 4, the water vapor generated by the moisture in the mortar layer 3 on the inner wall of the pipe under the action of heat cannot penetrate the first resin layer 4 in a short time, thereby ensuring that the second resin layer 5 is completely cured, avoiding the generation of a large number of pinholes or bubbling defects in the lining structure 2, and effectively improving the quality of the lining structure 2.

[0102] A second liquid resin can be sprayed on the side of the solidified first resin layer 4 facing away from the mortar layer 3 by high-pressure airless spraying or centrifugal spraying, and quickly solidified to form a second resin layer 5, which serves as an isolation and protective layer with high mechanical strength and chemical stability, thereby effectively isolating the seawater medium from the pipeline and reducing corrosion.

[0103] Therefore, the pipe forming method provided in the embodiment of the present application, by coating a double-layer resin lining structure on the surface of the mortar layer 3 on the inner wall of the pipe, not only solves the corrosion problem encountered by traditional steel cylinder concrete pipes during use, but also improves the safety and durability of the pipes, which is an important improvement for the cooling water system of nuclear power plants that rely on such pipes.

[0104] In one embodiment, referring to Figure 2 As shown, before scraping the first liquid resin, the steps further include:

[0105] S200 , pre-cleaning the surface of the mortar layer 3 on the inner wall of the tube body 1 .

[0106] For example, the treatment method can be high-pressure water jet cleaning, the pressure of the high-pressure water is between 15MPa and 70MPa, preferably between 25MPa and 50MPa, depending on the strength and surface cleanliness of the original mortar layer 3, and the cleaning equipment preferably includes a nozzle that automatically rotates along the central axis of the pipe. The nozzle of the nozzle is preferably a fan-shaped structure, and the distance from the nozzle to the surface of the mortar layer 3 on the inner wall of the pipe is between 10cm and 20cm.

[0107] The embodiment of the present application performs a pre-cleaning treatment on the surface of the mortar layer 3 to remove dust, oil, rust and other pollutants that affect the bonding effect, remove loose or damaged parts of the mortar layer 3, and ensure that the base is firm and flat. The pre-cleaning treatment can significantly improve the bonding strength between the first resin layer 4 and the mortar layer 3, thereby ensuring the integrity and sealing of the lining structure 2.

[0108] The pipeline provided in this application is further described below with reference to specific examples.

[0109] The pipeline used in the following example is a steel cylinder concrete pipeline, the pipe body 1 of the pipeline is a 2 mm thick steel plate, the inner wall of the pipe body 1 is provided with a 20 mm thick mortar layer 3, the outer wall of the pipe body 1 is provided with a reinforced concrete structure 6, and the conveying medium inside the pipeline is seawater.

[0110] The selected surface pre-cleaning treatment process is high-pressure water jet cleaning, using a self-rotating cleaning nozzle, the water pressure is 35MPa, the nozzle rotation speed is 50rpm, the distance from the nozzle of the nozzle to the surface of the mortar layer 3 on the inner wall of the pipe is 10cm, the surface deposits and loose mortar are removed, and the pipe is ventilated and dried.

[0111] Example 1:

[0112] In this embodiment, the second resin layer 5 is selected as the lining structure. The second resin layer 5 is a fast-curing high-strength polyurethane resin layer with a thickness ranging from 4mm to 6mm. The bonding strength between the second resin layer 5 and the first resin layer 4 is greater than the cohesive strength of the mortar layer 3; the bending strength of the second resin layer 5 is 65MPa. After the single-layer resin lining structure is formed, there are a large number of pinhole defects on the surface, such as Figure 3 shown.

[0113] Example 2:

[0114] Different from the above-mentioned example 1, this embodiment adds a first resin layer 4 as an isolation and sealing layer as the lining structure 2. The first resin layer 4 is a high-strength epoxy resin with a dynamic viscosity between 180Pa·s and 200Pa·s. After coating 1.0mm, the heat generated by the chemical reaction during the curing process causes the temperature of the resin layer to rise by less than 3°C. The bonding strength with the mortar layer 3 in the pipeline is 2.5MPa, and the water vapor permeability is 65g / (m 2 ·24h), and remain stable in alkaline environment, and the volume change rate is less than 10% after immersion in 1mol / L sodium hydroxide solution for 148h. After the double-layer resin lining structure is formed, the surface is smooth and has no defects, such as Figure 4 shown.

[0115] Therefore, by comparison, it can be seen that the present application introduces a double-layer resin lining structure on the surface of the mortar layer 3 inside the pipeline, which can avoid the generation of a large number of pinholes or bubbling defects in the lining structure 2, improve the quality of the lining structure 2, thereby improving the corrosion resistance and durability of the pipeline and extending its service life.

[0116] The above are only preferred embodiments of the present application and are not intended to limit the embodiments of the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A pipeline, comprising a pipe body, the inner wall of which is provided with a mortar layer, characterized in that: The pipeline also includes: The lining structure includes a first resin layer and a second resin layer. The first resin layer is arranged on the side of the mortar layer facing away from the inner wall of the tube body, and is used to isolate and seal the mortar layer; the second resin layer is arranged on the side of the first resin layer facing away from the mortar layer, and is used to isolate and seal the first resin layer.

2. The pipeline according to claim 1, characterized in that The first resin layer is bonded to the mortar layer; And / or, the second resin layer is bonded to the first resin layer.

3. The pipeline according to claim 2, characterized in that The bonding strength between the first resin layer and the mortar layer is greater than 1.5 MPa; Alternatively, the bonding strength between the first resin layer and the mortar layer is greater than the cohesive strength of the mortar layer.

4. The pipeline according to claim 2, characterized in that The bonding strength between the second resin layer and the first resin layer is greater than 5 MPa; Alternatively, the bonding strength between the second resin layer and the first resin layer is greater than the cohesive strength of the mortar layer.

5. The pipeline according to claim 1, characterized in that The first resin layer is a high-viscosity resin, and the dynamic viscosity of the high-viscosity resin is between 10 Pa·s and 250 Pa·s.

6. The pipeline according to claim 1, characterized in that The thickness of the first resin layer is between 0.2 mm and 1.0 mm; And / or, the water vapor permeability of the first resin layer is less than 80g / (m 2 ·24h).

7. The pipeline according to any one of claims 1 to 6, characterized in that The second resin layer is a polyurethane resin.

8. The pipeline according to claim 7, characterized in that The curing time of the second resin layer is between 15s and 45s; and / or, the thickness of the second resin layer is between 3.0 mm and 8.0 mm; And / or, the bending strength of the second resin layer is greater than 40 MPa.

9. A cooling water system for a nuclear power plant, characterized in that: include: The pipeline according to any one of claims 1 to 8, wherein the pipeline is used to transport cooling water.

10. A method for forming a pipe, characterized in that: include: Apply a first liquid resin on the surface of the mortar layer on the inner wall of the pipe body and solidify the first liquid resin to form a first resin layer; Spraying a second liquid resin on the surface of the first resin layer facing away from the mortar layer and rapidly curing the surface to form a second resin layer, so as to obtain a pipe with an inner lining structure; Wherein, the lining structure includes the first resin layer and the second resin layer.

11. The method for forming a pipe according to claim 10, characterized in that: Before scraping the first liquid resin, the method further comprises: The surface of the mortar layer on the inner wall of the tube body is pre-cleaned.

12. The method for forming a pipe according to claim 10, characterized in that: The first liquid resin is a high-viscosity resin, and the dynamic viscosity of the high-viscosity resin is between 10 Pa·s and 250 Pa·s.

13. The method for forming a pipe according to claim 10, characterized in that: The coating thickness of the first liquid resin is between 0.2 mm and 1.0 mm, and when the coating thickness of the first liquid resin is 1.0 mm, the heat generated by the first liquid resin during the curing process causes the temperature of the first resin layer to rise by less than 10° C.

14. The method for forming a pipe according to claim 10, characterized in that: The bonding strength between the first resin layer and the mortar layer is greater than 1.5 MPa, or the bonding strength between the first resin layer and the mortar layer is greater than the cohesive strength of the mortar layer; And / or, the water vapor permeability of the first resin layer is less than 80g / (m 2 ·24h).

15. The method for forming a pipe according to any one of claims 10 to 14, characterized in that: The second liquid resin is a polyurethane resin.

16. The method for forming a pipe according to claim 15, characterized in that: The curing time of the second liquid resin is between 15s and 45s; And / or, the coating thickness of the second liquid resin is between 3.0 mm and 8.0 mm.

17. The method for forming a pipe according to claim 15, characterized in that: The bonding strength between the second resin layer and the first resin layer is greater than 5 MPa, or the bonding strength between the second resin layer and the first resin layer is greater than the cohesive strength of the mortar layer; And / or, the bending strength of the second resin layer is greater than 40 MPa.

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