Prefabricated directly-buried thermal insulation pipe and preparation method thereof

Abstract

The invention discloses a prefabricated directly-buried thermal insulation pipe and a preparation method thereof.The prefabricated directly-buried thermal insulation pipe comprises unit thermal insulation pipes and connecting and locking assemblies, the unit thermal insulation pipes are locked through the connecting and locking assemblies, each unit thermal insulation pipe comprises a thermal insulation pipe body, and a first flange plate and a second flange plate are arranged at the two ends of each thermal insulation pipe body correspondingly; the second flange plate is provided with an inserting groove, the first flange plate is provided with an inserting head matched with the inserting groove, a sealing ring is arranged between the inserting head and the inserting groove, and the first flange plate and the second flange plate are locked through a connecting and locking assembly after being in butt joint. According to the heat preservation pipe, through the flexible aerogel felt heat preservation layer, the polyurethane foam heat preservation layer and the vacuum layer, and through a multi-layer heat preservation structure, it is ensured that the heat preservation pipe has the good heat preservation effect; the unit heat preservation pipes are directly positioned through the plugs and the slots, flange connectors do not need to be welded on site, locking can be completed only by sleeving the hoops and screwing the nuts, and compared with a traditional welding type pipeline, the installation efficiency is improved by more than 60%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of prefabricated direct-buried heat preservation pipes, in particular to a prefabricated direct-buried heat preservation pipe and a preparation method thereof. BACKGROUND

[0002] The prefabricated direct-buried heat preservation pipe is mainly used for regional heat supply external network pipelines. With the promotion of centralized heat supply by the state, its consumption is increasing, and its use range is also becoming wider. The prefabricated direct-buried heat preservation pipe has many advantages such as good waterproof and corrosion resistance, investment saving, shortening of construction period, low maintenance cost and the like.

[0003] The existing announcement No. CN113790583B discloses a prefabricated direct-buried heat preservation pipe, and specifically relates to the field of heat preservation pipes, which comprises a pre-buried mounting frame, an annular protective plate for supporting the heat preservation pipe is fixedly connected at the inner center of the pre-buried mounting frame, a holding seat with a separating function is arranged in the inner part of the annular protective plate, a heat preservation pipe seat is mounted in the inner part of the annular protective plate, heat preservation cotton with a heat preservation function is arranged in the inner part of the heat preservation pipe seat, an adding mechanism with an adding function is movably connected to the surface of the heat preservation pipe seat and located in the inner part of the annular protective plate, a recycling seat with a placing function is mounted in the inner part of the pre-buried mounting frame, and the pre-buried mounting frame comprises a connecting bracket seat. When in use, the heat preservation cotton can automatically absorb water vapor according to the changes of the external environment, thereby avoiding the problem that the heat preservation cotton is affected in use due to excessive moisture.

[0004] Although the existing technology has certain heat preservation performance, the existing heat preservation pipe is generally a single-layer heat preservation structure, and the heat preservation performance is limited. Therefore, the present application provides a prefabricated direct-buried heat preservation pipe and a preparation method thereof. SUMMARY

[0005] The present application aims to provide a prefabricated direct-buried heat preservation pipe and a preparation method thereof to solve the problems in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a prefabricated direct-buried heat preservation pipe, comprising unit heat preservation pipes and a connecting and locking assembly, the unit heat preservation pipes are locked by the connecting and locking assembly, the unit heat preservation pipe comprises a heat preservation pipe body, a first flange plate and a second flange plate are arranged at both ends of the heat preservation pipe body respectively, the second flange plate is provided with a insertion slot, the first flange plate is provided with a plug matched with the insertion slot, a sealing ring is arranged between the plug and the insertion slot, and the first flange plate and the second flange plate are locked by the connecting and locking assembly after being butted.

[0007] Preferably, the heat preservation tube body comprises a steel tube, a flexible aerogel felt heat preservation layer, a polyurethane foam heat preservation layer, a vacuum layer and a high-density polyethylene tube, the outer side of the steel tube is provided with the flexible aerogel felt heat preservation layer, the outer side of the flexible aerogel felt heat preservation layer is provided with the polyurethane foam heat preservation layer, the outer side of the polyurethane foam heat preservation layer is provided with the vacuum layer, and the outer side of the vacuum layer is provided with the high-density polyethylene tube.

[0008] Preferably, the connecting and locking assembly comprises a hoop, both ends of the hoop are provided with connecting ears, one of the connecting ears is rotatably installed with a connecting rod, the other connecting ear is rotatably installed with a rotating shaft, the connecting rod penetrates through the rotating shaft, and the connecting rod is installed with a nut for adjusting the position of the rotating shaft in the connecting rod; the middle part of the inner side of the hoop is provided with a middle limiting plate, the two sides of the hoop located on the middle limiting plate are provided with outer limiting plates, and gaps are arranged between the outer limiting plates and the middle limiting plate.

[0009] Preferably, the connecting rod is in the shape of T, and the rotating shaft is provided with a through hole for the connecting rod to penetrate.

[0010] Preferably, the two sides of the outer limiting plate and the middle limiting plate are both provided with an outer seat matched with the heat preservation tube body, and the outer limiting plate and the middle limiting plate are both provided with a limiting groove matched with the flange plate.

[0011] Preferably, the outer limiting plate is connected between one end of the middle limiting plate and the hoop by welding, and the other end of the outer limiting plate and the hoop are in an open structure.

[0012] A preparation method of a prefabricated directly-buried heat preservation tube comprises the following steps: S1, steel tube pretreatment: cleaning treatment is performed on the steel tube to ensure that the surface of the steel tube is free of impurities; S2, preparation of the flexible aerogel felt heat preservation layer: the flexible aerogel felt is cut into a size matched with the circumference of the steel tube, and is spirally wound on the outer side of the steel tube by using a high-temperature-resistant adhesive, the overlapping rate is controlled to be 10%-15%, and no gap is ensured; after coating, the flexible aerogel felt is temporarily fixed by using a high-temperature-resistant adhesive tape, and is left to stand for 24 hours until the adhesive is solidified; S3, preparation of the polyurethane foam heat preservation layer: a high-density polyethylene tube is sleeved on the outer side of the flexible aerogel felt heat preservation layer, and the two ends are sealed by using sealing plugs; polyurethane foam raw liquid is injected into the gap between the polyethylene tube and the aerogel felt by using a special pouring device, and is solidified at room temperature for 24-48 hours to form the polyurethane foam heat preservation layer; S4, preparation of the vacuum layer: an aluminum foil barrier film is wound on the outer side of the polyurethane foam heat preservation layer, and a polyethylene sleeve pipe with a vacuumizing interface is sleeved; the space between the sleeve pipe and the aluminum foil film is vacuumized to a vacuum degree of 1≤Pa by using a vacuumizing device, then the vacuumizing interface is sealed to form the vacuum layer; finally, the outer temporary sleeve pipe is removed, and the high-density polyethylene tube is left as the outer protection. S5, preparation of the connecting and locking assembly: the steel plate is rolled to prepare the hoop and the connecting lug, the steel structure is used to prepare the connecting rod and the rotating shaft, the middle limiting plate and the outer limiting plate are prepared by the steel plate, and the parts are assembled; S6, locking of the unit heat preservation pipe: the hoop is sleeved outside the flange after butt joint, the middle limiting plate and the outer limiting plate are clamped outside the flange plate, the nut is tightened, the rotating shaft is driven to slide along the connecting rod, the hoop is tightened, and the flange plate is not loose.

[0013] Compared with the prior art, the beneficial effects of the present application are: Through the flexible aerogel felt heat preservation layer, the polyurethane foam heat preservation layer and the vacuum layer, through the multi-layer heat preservation structure, it is ensured that the heat preservation pipe has good heat preservation effect.

[0014] The flexible aerogel felt as the inner layer can directly block the heat conduction of the steel pipe; the intermediate polyurethane foam heat preservation layer fills the gap and reduces the air convection heat exchange; the outer vacuum layer completely eliminates the heat conduction of gas, greatly reduces the heat loss of hot water, steam and other media in the conveying process, and the energy saving rate is increased by 30%-50% compared with the traditional heat preservation pipe. The composite heat preservation layer is stable in performance within the range of-50℃ to 120℃, can effectively prevent the condensation and freezing crack of the outer wall of the pipeline in low temperature environment, and is suitable for cold regions in north China or low temperature medium conveying scene.

[0015] The plug of the first flange plate precisely matches the slot of the second flange plate, the plug is inserted into the slot to extrude the sealing ring, a first sealing barrier is formed, can withstand 1.5 times working pressure, and direct leakage of the medium in the pipe is avoided. After the hoop of the connecting and locking assembly is tightened, the outer limiting plate and the middle limiting plate firmly clamp the flange plate through the limiting groove, the outer seat is attached to the heat preservation pipe body, which not only prevents the misalignment of the flange joint due to external force, but also further compresses the sealing ring, strengthens the sealing effect, and reduces the leakage rate of the butt joint part to below 0.1%.

[0016] The unit heat preservation pipe is directly positioned through the plug and the slot, does not need to weld the flange joint on site, and only needs to put on the hoop and tighten the nut to complete the locking, so that the installation efficiency is increased by more than 60% compared with the traditional welded pipe, and the risk of on-site open flame operation is reduced.

[0017] The outer seat on the inner side of the hoop is attached to the heat preservation pipe body, and the limiting groove precisely matches the flange plate, which can automatically compensate for the slight coaxiality deviation during pipeline installation, reduces the requirement for the operation accuracy of the construction personnel, and reduces the rework rate. DETAILED DESCRIPTION

[0018] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation of the present application. In the drawings: Figure 1 is a structural schematic diagram of the present application; Figure 2 is a structural schematic diagram of the unit heat preservation pipe of the present application; Figure 3 is a component diagram of the heat preservation pipe body of the present application; Figure 4 is a structural schematic diagram of the connecting and locking assembly of the present application; Figure 5 is a front view of the connecting and locking assembly of the present application; Figure 6 is a structural schematic diagram of the limiting plate of the present application.

[0019] In the figure: 1, unit heat preservation pipe; 2, connecting and locking assembly; 11, heat preservation pipe body; 12, first flange plate; 13, second flange plate; 14, insertion slot; 111, steel pipe; 112, flexible aerogel felt heat preservation layer; 113, polyurethane foam heat preservation layer; 114, vacuum layer; 115, high-density polyethylene pipe; 21, hoop; 22, connecting lug; 23, connecting rod; 24, pivot; 25, nut; 26, external limiting plate; 27, gap; 28, middle limiting plate; 261, external seat; 262, limiting slot. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0021] Please refer to Figures 1-6The embodiment of the present application is a prefabricated directly-buried heat preservation pipe, which comprises unit heat preservation pipes 1 and connecting and locking assemblies 2, the unit heat preservation pipes 1 are locked by the connecting and locking assemblies 2, the unit heat preservation pipe 1 comprises a heat preservation pipe body 11, the heat preservation pipe body 11 is provided with a first flange plate 12 and a second flange plate 13 at two ends respectively, the second flange plate 13 is provided with a slot 14, the first flange plate 12 is provided with a plug matched with the slot 14, a sealing ring is arranged between the plug and the slot 14, the sealing ring prevents medium leakage or external moisture from entering, the first flange plate 12 and the second flange plate 13 are locked by the connecting and locking assembly 2 after abutting, the plug of the first flange plate is accurately matched with the slot of the second flange plate, the plug is pressed against the sealing ring when being inserted into the slot, forming a first sealing barrier, which can withstand 1.5 times working pressure, avoiding direct leakage of the medium in the pipe. After the hoop of the connecting and locking assembly is tightened, the external limiting plate and the middle limiting plate firmly hold the flange plate through the limiting slot, the external seat is attached to the heat preservation pipe body, which prevents the flange joint from being dislocated due to external force, further compresses the sealing ring, and strengthens the sealing effect, so that the leakage rate of the abutting part is reduced to below 0.1%.

[0022] The heat preservation pipe body 11 comprises a steel pipe 111, a flexible aerogel felt heat preservation layer 112, a polyurethane foam heat preservation layer 113, a vacuum layer 114 and a high-density polyethylene pipe 115, the outer side of the steel pipe 111 is provided with the flexible aerogel felt heat preservation layer 112, the flexible aerogel felt heat preservation layer 112 blocks heat transfer by using the low thermal conductivity of aerogel, the outer side of the flexible aerogel felt heat preservation layer 112 is provided with the polyurethane foam heat preservation layer 113, the polyurethane foam heat preservation layer 113 can fill the gaps of the aerogel felt and buffer the extrusion of the outer layer structure to the inner side, the outer side of the polyurethane foam heat preservation layer 113 is provided with the vacuum layer 114, the vacuum layer 114 further reduces heat conduction, the vacuum environment has almost no convection heat transfer, and the heat preservation efficiency is greatly improved, the outer side of the vacuum layer 114 is provided with the high-density polyethylene pipe 115, the high-density polyethylene pipe 115 can resist soil corrosion and external force impact, and protect the internal heat preservation layer from being damaged.

[0023] The connecting and locking assembly 2 comprises a hoop 21, both ends of the hoop 21 are provided with connecting ears 22, one of the connecting ears 22 is rotatably installed with a connecting rod 23, the other connecting ear 22 is rotatably installed with a rotating shaft 24, the connecting rod 23 penetrates through the rotating shaft 24, the rotating shaft 24 can slide along the connecting rod to adapt the opening and closing degree of the hoop, the connecting rod 23 is installed with a nut 25 for adjusting the position of the rotating shaft 24 on the connecting rod 23; the middle part of the inner side of the hoop 21 is provided with a middle limiting plate 28, the two sides of the hoop 21 located at the middle limiting plate 28 are provided with outer limiting plates 26, and gaps 27 are arranged between the outer limiting plates 26 and the middle limiting plate 28; the connecting rod 23 is in T-shaped, the rotating shaft 24 is provided with a through hole for the connecting rod 23 to penetrate, one end of the connecting rod 23 is rotatably connected with one connecting ear, the other end of the connecting rod 23 penetrates through the rotating shaft 24, and the tightness of the hoop is controlled by length adjustment.

[0024] The two sides of the outer limiting plate 26 and the middle limiting plate 28 are provided with an outer seat 261 abutting with the heat preservation pipe body 11, the outer limiting plate 26 and the middle limiting plate 28 are provided with limiting grooves 262 matched with the flange plate, the limiting grooves 262 are matched with the edge of the flange plate, the flange plate is clamped, and axial displacement of the flange is prevented in use; the one end of the outer limiting plate 26 located between the middle limiting plate 28 and the hoop 21 is connected by welding, and the other end of the outer limiting plate 26 and the hoop 21 are in an open structure.

[0025] A preparation method of a prefabricated directly-buried heat preservation pipe, comprising the following steps: S1, steel pipe 111 pretreatment: cleaning treatment is performed on the steel pipe 111 to ensure that the surface of the steel pipe 111 is free of impurities; S2, preparation of flexible aerogel felt heat preservation layer 112: the flexible aerogel felt is cut into a size matched with the circumference of the steel pipe, and is spirally wound outside the steel pipe 111 by using a high-temperature-resistant adhesive, the overlapping rate is controlled to be 10%-15%, and no gap is ensured; after coating, a high-temperature-resistant adhesive tape is used for temporary fixing, and the adhesive is cured after 24 hours of standing; S3, preparation of polyurethane foam heat preservation layer 113: a customized high-density polyethylene pipe 115 is sleeved outside the flexible aerogel felt heat preservation layer 112, and both ends are sealed by sealing plugs; polyurethane foam raw liquid is injected into the gap between the polyethylene pipe and the aerogel felt through a special pouring device, and the polyurethane foam heat preservation layer 113 is formed after 24-48 hours of normal temperature curing; S4, preparation of vacuum layer 114: an aluminum foil barrier film is wound outside the polyurethane foam heat preservation layer 113, and a polyethylene sleeve pipe with a vacuumizing interface is sleeved; the space between the sleeve pipe and the aluminum foil film is vacuumized to a vacuum degree of ≤1 Pa through a vacuumizing device, and then the vacuumizing interface is sealed to form the vacuum layer 114; finally, the outer temporary sleeve pipe is removed, and the high-density polyethylene pipe 115 is left as an outer protection; S5, the preparation of the connecting locking assembly 2: the hoop and connecting lug are rolled by steel plate, the connecting rod 23 and the rotating shaft 24 are prepared by steel structure, the middle limiting plate and the outer limiting plate 26 are prepared by steel plate, and the parts are assembled; S6, locking of the unit heat preservation pipe: the hoop 21 is sleeved outside the flange after butt joint, the middle limiting plate and the outer limiting plate 26 are clamped outside the flange plate, the nut 25 is screwed, the rotating shaft 24 is driven to slide along the connecting rod 23, the hoop 21 is tightened, and the flange plate is not loose.

[0026] The working principle of the present application is as follows: the steel pipe 111 is cleaned to ensure that the surface of the steel pipe 111 is free of impurities; the flexible aerogel felt is cut to a size matching the circumference of the steel pipe, and is spirally wound outside the steel pipe 111 using a high-temperature-resistant adhesive, with an overlapping rate controlled at 10%-15% to ensure no gap; after coating, the high-temperature-resistant adhesive tape is used for temporary fixing, and the adhesive is cured for 24 hours; the customized high-density polyethylene pipe 115 is sleeved outside the flexible aerogel felt insulation layer 112, and the two ends are sealed with sealing plugs; the polyurethane foam solution is injected into the gap between the polyethylene pipe and the aerogel felt through a special pouring equipment, and is cured at room temperature for 24-48 hours to form a polyurethane foam insulation layer 113; an aluminum foil barrier film is wound outside the polyurethane foam insulation layer 113, and then a layer of polyethylene sleeve pipe with a vacuum interface is sleeved; the space between the sleeve pipe and the aluminum foil film is vacuumed to a vacuum degree of ≤1 Pa through a vacuum extraction equipment, and then the vacuum extraction interface is sealed to form a vacuum layer 114; finally, the outer temporary sleeve pipe is removed, and the high-density polyethylene pipe 115 is left as the outer protection; the hoop and connecting lug are rolled by steel plate, the connecting rod 23 and the rotating shaft 24 are prepared by steel structure, the middle limiting plate and the outer limiting plate 26 are prepared by steel plate, and the parts are assembled; the hoop 21 is sleeved outside the flange after butt joint, the middle limiting plate and the outer limiting plate 26 are clamped outside the flange plate, the nut 25 is screwed, the rotating shaft 24 is driven to slide along the connecting rod 23, the hoop 21 is tightened, and the flange plate is not loose.

[0027] Finally, it should be noted that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements of some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A prefabricated direct-buried insulated pipe, comprising a unit insulated pipe (1) and a connecting locking assembly (2), characterized in that: The unit insulation pipes (1) are locked together by a connecting locking assembly (2). The unit insulation pipe (1) includes an insulation pipe body (11). The two ends of the insulation pipe body (11) are respectively provided with a first flange plate (12) and a second flange plate (13). The second flange plate (13) has a slot (14). The first flange plate (12) is provided with a plug that mates with the slot (14). A sealing ring is provided between the plug and the slot (14). The first flange plate (12) and the second flange plate (13) are locked together by the connecting locking assembly (2).

2. The prefabricated direct-buried insulated pipe according to claim 1, characterized in that: The main body (11) of the insulation pipe includes a steel pipe (111), a flexible aerogel felt insulation layer (112), a polyurethane foam insulation layer (113), a vacuum layer (114), and a high-density polyethylene pipe (115). The flexible aerogel felt insulation layer (112) is provided on the outside of the steel pipe (111), the polyurethane foam insulation layer (113) is provided on the outside of the flexible aerogel felt insulation layer (112), the vacuum layer (114) is provided on the outside of the polyurethane foam insulation layer (113), and the high-density polyethylene pipe (115) is provided on the outside of the vacuum layer (114).

3. The prefabricated direct-buried insulated pipe according to claim 1, characterized in that: The connecting locking assembly (2) includes a clamp (21), both ends of which are provided with connecting ears (22). One connecting ear (22) is rotatably mounted with a connecting rod (23), and the other connecting ear (22) is rotatably mounted with a rotating shaft (24). The connecting rod (23) passes through the rotating shaft (24), and the connecting rod (23) is equipped with a nut (25) for adjusting the position of the rotating shaft (24) on the connecting rod (23). A central limiting plate (28) is provided in the middle of the inner side of the clamp (21), and external limiting plates (26) are provided on both sides of the clamp (21) located on the central limiting plate (28). A gap (27) is provided between the external limiting plate (26) and the central limiting plate (28).

4. A prefabricated direct-buried insulated pipe according to claim 3, characterized in that: The connecting rod (23) is T-shaped, and the rotating shaft (24) has a through hole through which the connecting rod (23) passes.

5. A prefabricated direct-buried insulated pipe according to claim 3, characterized in that: Both sides of the external limiting plate (26) and the middle limiting plate (28) are provided with external seats (261) that fit with the main body (11) of the insulation pipe. Both the external limiting plate (26) and the middle limiting plate (28) are provided with limiting grooves (262) that cooperate with the flange plate.

6. A prefabricated direct-buried insulated pipe according to claim 3, characterized in that: The external limiting plate (26) is welded to the clamp (21) at one end of the middle limiting plate (28), and the other end of the external limiting plate (26) is open to the clamp (21).

7. A method for preparing a prefabricated direct-buried insulated pipe, characterized in that: Includes the following steps: S1. Pretreatment of steel pipe (111): Clean the steel pipe (111) to ensure that there are no impurities on the surface of the steel pipe (111); S2, Preparation of flexible aerogel felt insulation layer (112): The flexible aerogel felt is cut to a size that matches the circumference of the steel pipe, and is spirally wound around the outside of the steel pipe (111) with a high-temperature resistant adhesive. The winding overlap rate is controlled at 10%-15% to ensure no gaps. After wrapping, it is temporarily fixed with high-temperature resistant tape and left to stand for 24 hours for the adhesive to cure. S3. Preparation of polyurethane foam insulation layer (113): A customized high-density polyethylene pipe (115) is fitted on the outside of the flexible aerogel felt insulation layer (112), and both ends are sealed with sealing plugs; polyurethane foam liquid is injected into the gap between the polyethylene pipe and the aerogel felt through a special injection equipment, and cured at room temperature for 24-48 hours to form polyurethane foam insulation layer (113). S4. Preparation of vacuum layer (114): A layer of aluminum foil barrier film is wrapped around the outside of polyurethane foam insulation layer (113), and then a layer of polyethylene sleeve with vacuum interface is fitted. The space between the sleeve and the aluminum foil film is evacuated to a vacuum degree ≤1Pa by vacuum equipment, and then the vacuum interface is sealed to form vacuum layer (114). Finally, the outer temporary sleeve is removed, and the high-density polyethylene pipe (115) is retained as outer protection. S5. Preparation of connecting locking assembly (2): The clamp and connecting lug are made by rolling steel plate, the connecting rod (23) and the rotating shaft (24) are made by steel structure, the middle limiting plate and the outer limiting plate (26) are made by steel plate, and the components are assembled. S6. Locking the unit insulation pipe: Put the clamp (21) on the outside of the flange after docking, and clamp the middle limiting plate and the outer limiting plate (26) on the outside of the flange plate. Tighten the nut (25), drive the rotating shaft (24) to slide along the connecting rod (23), tighten the clamp (21) until the flange plate is no longer loose.

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