Prefabricated insulated pipeline

Abstract

A prefabricated insulated pipeline, comprising a working steel pipe. An outer casing steel pipe is sleeved on an outer side of the working steel pipe, a support base is provided at each of the two ends of the working steel pipe, and the support bases, the working steel pipe, and the outer casing steel pipe constitute a closed chamber. By using an ultra-fine glass wool blanket having a thickness of 250 mm and performing gas replacement on a thermal insulation interlayer to replace air with carbon dioxide, the thermal insulation effect is significantly improved. Glass wool is used as a thermal insulation material, thereby reducing costs. By providing the support bases made of rigid polyurethane foam at the two ends of the pipeline and forming a sealed chamber between the outer casing steel pipe, the support bases, and the working steel pipe, structural stability and sealing performance are enhanced.

Description

Pre-insulated pipes Technical Field

[0001] This application relates to the field of thermal insulation pipe technology, and more specifically, to prefabricated thermal insulation pipes. Background Technology

[0002] Precast direct-buried cold (hot) water insulated pipes have been around for over 50 years since their introduction in the 20th century. Their structure consists of a steel core pipe (working pipe), a high-density polyethylene outer steel pipe, and a rigid polyurethane foam insulation layer. The rigid polyurethane foam is bonded to the polyethylene outer steel pipe and the working steel pipe, forming a three-in-one structure suitable for non-compensated laying methods.

[0003] The thickness of the polyurethane foam layer varies from 40mm to 90mm depending on the pipe diameter. When a compensated design is used to construct the pipeline network, the thermal expansion and contraction of the working steel pipe causes the rigid polyurethane foam layer to tear and the outer casing joint to be damaged, which has always been a major pain point in the industry.

[0004] In addition, an insulation layer of 40mm to 90mm thickness is not a reasonable thickness for urban heating networks.

[0005] Among commonly used insulation materials, rigid polyurethane foam has the lowest thermal conductivity. Using conventional thinking to design hot and cold water insulation pipes, it is difficult to make breakthroughs in the current insulation pipe structure.

[0006] In terms of steam insulation pipes, in order to improve insulation capacity, the industry has begun to use nanoporous aerogel felt extensively. Aerogel felt has better insulation performance than polyurethane foam and a number of conventional insulation materials. However, the price of aerogel felt is 8-10 times that of polyurethane foam, and even more than 20 times that of glass wool, which greatly increases the cost of pipeline construction. Summary of the Invention

[0007] This application aims to at least address the long-standing problem in the existing technology of traditional prefabricated direct-buried cold (hot) water insulation pipes that use rigid polyurethane foam as the insulation layer, where the insulation effect has not been improved. Therefore, this application proposes a high-efficiency insulation pipe and its implementation method.

[0008] According to an embodiment of this application, a prefabricated insulated pipe includes a working steel pipe, an outer steel pipe is sleeved on the outside of the working steel pipe, and support seats are provided at both ends of the working steel pipe. The working steel pipe support seats and the outer steel pipe constitute a closed compartment.

[0009] Furthermore, the enclosed compartment, which is sealed on all four sides, is filled with fluffy, porous glass wool.

[0010] Furthermore, the sealed chamber, which is in a low vacuum state, is re-injected with a gas of low thermal conductivity to achieve gas replacement.

[0011] Furthermore, the support is made of rigid closed-cell polyurethane foam.

[0012] Furthermore, positioning steel plates are provided on the outside of the working steel pipe and the outer steel pipe. There are at least three positioning steel plates, which are evenly distributed along the circumference. The positioning steel plates are fixed to the working steel pipe and the outer steel pipe by welding.

[0013] 1. The beneficial effects of this application are: by using 250mm thick ultrafine glass wool felt and implementing gas replacement on the insulation interlayer, replacing air with carbon dioxide, the insulation effect is significantly improved; by using glass wool as the insulation material, the cost is saved; by setting support seats made of rigid polyurethane foam at both ends of the pipe and forming a sealed chamber between the outer steel pipe, the support seats and the working steel pipe, the stability and sealing performance of the structure are enhanced.

[0014] 2. The beneficial effects of this application are: In order to prevent the steel pipe from being misaligned during transportation and hoisting, the two pipes are welded and fixed with steel plates before leaving the factory. The positioning steel plate is removed before the pipeline interface is closed during pipeline construction. At the same time, the working steel pipe and the outer steel pipe can be flexibly connected by the use of positioning sleeves, screws and fixing blocks, which can replace the use of positioning steel plates and improve the efficiency of disassembly.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 is a schematic diagram of the overall three-dimensional structure of the prefabricated insulated pipe according to an embodiment of this application;

[0018] Figure 2 is a top view of the overall structure according to an embodiment of this application;

[0019] Figure 3 is a schematic cross-sectional view of the structure along point AA in Figure 2 according to an embodiment of this application;

[0020] Figure 4 is a cross-sectional schematic diagram of the outer steel tube structure according to an embodiment of this application;

[0021] Figure 5 is a schematic diagram of the installation state of the positioning sleeve according to an embodiment of this application;

[0022] Figure 6 is a schematic diagram of the disassembled positioning sleeve and working steel pipe structure according to an embodiment of this application;

[0023] Figure 7 is a schematic diagram of the structure at point A in Figure 6 according to an embodiment of this application;

[0024] Figure 8 is a schematic diagram of the positioning sleeve, screw, etc. according to an embodiment of this application;

[0025] Figure 9 is a planar structural schematic diagram of Figure 8 according to an embodiment of this application.

[0026] Reference numerals: 1. Working steel pipe; 2. Positioning steel plate; 3. Outer steel pipe; 4. Support base; 5. Copper ring; 6. Glass wool; 7. Fixing block; 8. Insert rod; 9. Positioning sleeve; 10. Positioning groove; 11. Screw; 12. Nut; 13. Insertion hole; 14. Slide rail; 15. Lead screw; 16. Clamp. Detailed Implementation

[0027] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the equipment or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0033] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] The following describes a prefabricated insulated pipe according to an embodiment of this application, with reference to the accompanying drawings.

[0036] Example 1

[0037] As shown in Figures 1-4, the prefabricated insulated pipe according to the embodiment of this application includes a working steel pipe 1, an outer steel pipe 3 is sleeved on the outside of the working steel pipe 1, the outer steel pipe 3 is made of steel pipe, and support seats 4 are provided at both ends of the working steel pipe 1. The outer steel pipe 3, the support seats 4 and the working steel pipe 1 form a sealed chamber. In order to improve the insulation effect, the air in the sealed chamber is replaced with carbon dioxide. The thermal conductivity of carbon dioxide is lower than that of air, which means that it can more effectively prevent heat conduction, thereby improving the overall insulation effect of the insulation layer.

[0038] Furthermore, the sealed chamber is filled with glass wool 6, which is a 250mm thick ultra-fine glass wool felt. It is laid on the outside of the working steel pipe 1. Glass wool 6 serves as the main insulation material, replacing the traditional rigid polyurethane foam, and optimizing the insulation effect.

[0039] In order to prevent carbon dioxide from escaping, the end face of the insulation layer is sealed with sealant, that is, the glass wool 6 and the support base 4 are sealed with sealant.

[0040] The support base 4 is tightly connected to the working steel pipe 1 through the internally set copper ring 5, and the support base 4 is made of rigid polyurethane foam to enhance structural stability and sealing performance.

[0041] This invention can be applied not only to air conditioning chilled water pipe networks, but also to hot water heating pipe networks and steam supply pipe networks. When used in steam pipe networks, the inner ring of the support base 4 supporting the working steel pipe 1 is made of microporous calcium silicate tile, and the outer ring is made of rigid polyurethane foam.

[0042] As shown in Figure 1, in order to prevent the working steel pipe 1 and the outer steel pipe 3 from misaligning during transportation and hoisting, thus damaging the end face seal of the insulation layer, the working steel pipe 1 and the outer steel pipe 3 are welded together with positioning steel plate 2 before the insulation pipe leaves the factory. The positioning steel plate 2 is removed before the pipeline interface is closed during pipeline construction, and the positioning steel plate 2 is used to prevent the working steel pipe 1 and the outer steel pipe 3 from misaligning.

[0043] Example: with Taking air conditioning chilled water pipes as an example, the chilled water temperature is 5℃ and the soil temperature in the area where the pipes are laid is 25℃. According to traditional processes, the steel pipes are wrapped with a 50mm thick rigid polyurethane foam insulation layer. After calculation, the cold loss intensity q of the pipe network is equal to 18.82w / m.

[0044] According to the implementation of the present invention, By laying 250mm thick ultrafine glass wool felt on the outside of the steel pipe and implementing gas replacement in the insulation interlayer, the cold loss intensity of the pipeline network can be reduced to 4.59w / m under the same conditions. Compared with the traditional method, the cold loss is reduced by 3 / 4.

[0045] Based on a cost of 560 yuan per cubic meter for glass wool 6, the cost of glass wool 6 per meter of pipe in this case is 387 yuan. According to the traditional process for making insulated cold water pipes, laying 230mm thick nano aerogel can achieve the same effect of 4.59w / m of cold loss. However, the cost of aerogel is 8000 yuan per cubic meter, which is 4972 yuan / meter, which is 12 times higher than the 387 yuan / meter of this invention.

[0046] Therefore, this solution addresses the problems of insufficient insulation, poor structural stability, low economic efficiency, and limited applicability compared to traditional insulation pipes.

[0047] Example 2

[0048] In addition, as shown in Figures 5 to 9, considering the inconvenience of disassembly after positioning the working steel pipe 1 and the outer steel pipe 3 by the positioning steel plate 2, improvements are made based on the above embodiments.

[0049] At least three fixing blocks 7 are distributed in a ring on the outer side of the outer steel pipe 3. Each fixing block 7 has a through hole. A positioning sleeve 9 is fitted onto the end of the working steel pipe 1. The positioning groove 10 on the inner side of the positioning sleeve 9 is engaged with the end of the working steel pipe 1 to fix the positioning sleeve 9 to the end of the working steel pipe 1. Since at least three screws 11 are distributed in a ring on the outer side of the positioning sleeve 9, the screws 11 are threaded through the fixing blocks 7 and connected to the nuts 12 to connect the working steel pipe 1 and the outer steel pipe 3.

[0050] Furthermore, a plug rod 8 is threadedly connected to one end of the fixing block 7. The plug rod 8 is inserted into the insertion hole 13 at one end of the screw 11. Rotating the plug rod 8 allows it to enter the insertion hole 13, further fixing the screw 11 and preventing it from shaking.

[0051] Furthermore, slide rails 14 are symmetrically arranged on both sides of the positioning sleeve 9, and lead screws 15 are rotatably installed inside each of the two slide rails 14. The two lead screws 15 are threadedly connected to two oppositely arranged clamps 16. One end of the clamp 16 is slidably connected to the slide rail 14. Therefore, when the lead screw 15 rotates, it causes the two clamps 16 to move closer to the working steel pipe 1 and fix the working steel pipe 1, further improving the stability of fixing the working steel pipe 1. At the same time, this structure is more flexible, easy to disassemble, and easy to reuse.

[0052] The working principle of prefabricated insulated pipes: A support seat 4 is set at each end of the working steel pipe 1. The outer steel pipe 3, the support seat 4 and the working steel pipe 1 form a sealed chamber. In order to improve the insulation effect, the air in the sealed chamber is replaced with carbon dioxide. In order to prevent carbon dioxide from escaping from the sealed chamber, the end face of the insulation layer is sealed with sealant. In order to prevent the working steel pipe 1 and the outer steel pipe 3 from being misaligned during transportation and hoisting, which would damage the seal of the end face of the insulation layer, the working steel pipe 1 and the outer steel pipe 3 are welded with positioning steel plate 2 before the insulated pipe leaves the factory. The positioning steel plate 2 needs to be removed before the pipe interface is sealed during pipeline construction.

[0053] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0054] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. The thermal insulation structure, materials, and implementation methods of this invention are applicable to aircraft, automobiles, trains, ships, cold storage facilities, factories, public buildings, residences, and other places requiring thermal insulation. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A prefabricated insulated pipe, characterized in that: It includes a working steel pipe (1), an outer steel pipe (3) is fitted on the outside of the working steel pipe (1), and support seats (4) are provided at both ends of the working steel pipe (1). The working steel pipe (1), support seats (4) and outer steel pipe (3) constitute a closed chamber.

2. The prefabricated insulated pipe according to claim 1, characterized in that: The enclosed compartment, which is sealed on all four sides, is filled with fluffy, porous glass wool (6).

3. The prefabricated insulated pipe according to claim 2, characterized in that: All the air in the sealed chamber was extracted, achieving a low vacuum level.

4. The prefabricated insulated pipe according to claim 3, characterized in that: The sealed chamber, which is in a low vacuum state, is re-injected with a gas of low thermal conductivity to achieve gas replacement.

5. The prefabricated insulated pipe according to claim 1, characterized in that: The support base (4) is made of rigid closed-cell polyurethane foam.

6. The prefabricated insulated pipe according to claim 1, characterized in that: Positioning steel plates (2) are provided on the outside of the working steel pipe (1) and the outer steel pipe (3). There are at least 3 positioning steel plates (2) evenly distributed along the circumference. The positioning steel plates (2) are fixed to the working steel pipe (1) and the outer steel pipe (3) by welding.

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