Thermal insulation pipeline, construction method and application

Abstract

The application discloses a heat preservation pipeline, a construction method and application, comprising a plurality of heat preservation pipe units capable of coaxial sealing connection, the heat preservation pipe unit comprises an inner pipe and an outer pipe which are coaxially sleeved, one end of the inner pipe extends out of one end of the outer pipe, and a mounting flange is fixedly connected to the end of the inner pipe extending out of the outer pipe; a sealed vacuum cavity is formed between the outer wall of the inner pipe and the inner wall of the outer pipe; the inner pipe comprises a first straight pipe section, a first tapered pipe section and a second straight pipe section which are sequentially arranged in a communication mode from back to front; the outer pipe comprises a third straight pipe section, a second tapered pipe section and a fourth straight pipe section which are integrally connected in a sequential arrangement mode from back to front; and a plate type positioning ring and a clamping flange are sequentially arranged from back to front at the connection position of the second tapered pipe section and the fourth straight pipe section. The heat preservation pipeline prepared by the method has the characteristics of high temperature resistance, light weight, high mechanical strength and low apparent thermal conductivity, and cannot be easily damaged, and can meet the application requirements of long-distance conveying of high-temperature hot water in a well or a tunnel.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of geothermal energy development pipeline, in particular to a heat preservation pipeline, construction method and application. BACKGROUND

[0002] The working face of high-temperature mine and high-temperature tunnel has a high temperature, which is a heat damage to the normal work of the mine and the tunnel. In order to eliminate and utilize the heat damage, the underground hot water as the source of the heat damage needs to be transported out through a heat preservation pipeline. The temperature of the underground hot water is high at the heat source, and the transportation distance is long. The temperature drop of the general heat preservation pipeline is high during long-distance transportation, which makes the heat preservation pipeline itself become a long-distance heat source, which is not conducive to the elimination of the heat damage. Therefore, a pipeline with good heat preservation performance, high structural strength, simple construction process, long service life and convenient maintenance is needed. The commonly used heat preservation pipelines mainly include non-metallic pipes such as PE pipe, PE-RT pipe and PPH pipe, and special heat insulation oil pipes for petroleum. The two types of commonly used pipelines have the following defects: (1) Non-metallic heat preservation pipe: easy to corrode and oxidize in a complex and humid environment, resulting in failure of the heat preservation layer and low pipeline strength, which is not conducive to application in complex engineering environments; the pipeline has a large apparent thermal conductivity and low heat insulation level, causing a large amount of heat to be emitted to the surrounding by the heat transfer medium, which is not conducive to the elimination of the heat damage; the temperature resistance of the pipeline is low, and when the temperature of the hot water is high, the mechanical properties and service life of the pipeline are greatly reduced, which cannot be used for long-term application in the heat damage treatment of high-temperature mines and tunnels. (2) Special heat insulation oil pipe for petroleum: the weight of the buried pipeline is large, and large equipment needs to be used for pipe installation and later maintenance, which has high use and maintenance costs.

[0003] In summary, the existing non-metallic pipes such as PE pipe, PE-RT pipe and PPH pipe and the special heat insulation oil pipe for petroleum cannot simultaneously have high pipeline strength, small density, high temperature resistance and low apparent thermal conductivity, and cannot meet the application requirements of long-distance transportation of high-temperature hot water to eliminate the heat damage in high-temperature mines and tunnels. SUMMARY

[0004] In view of the defects and deficiencies in the prior art, the present application provides a heat preservation pipeline and a preparation method thereof, to solve the technical problem of poor strength and temperature resistance of the heat preservation pipeline used for transporting underground hot water in mines and tunnels in the prior art.

[0005] To achieve the above-mentioned purposes, the present application adopts the following technical solutions:

[0006] A heat preservation pipeline comprises a plurality of heat preservation pipe units capable of being coaxially and sealingly connected, the heat preservation pipe unit comprises an inner pipe and an outer pipe which are coaxially sleeved, the inner pipe and the outer pipe are both open at both axial ends, one end of the inner pipe protrudes from one end of the outer pipe, and a mounting flange is fixedly connected to the end of the inner pipe protruding from the outer pipe, a sealed vacuum cavity is formed between the outer wall of the inner pipe, the side wall of the mounting flange and the inner wall of the outer pipe.

[0007] The inner pipe comprises a first straight pipe section, a first tapered pipe section and a second straight pipe section which are arranged in sequence from back to front, the first straight pipe section is connected with the large-diameter end of the first tapered pipe section, and the second straight pipe section is connected with the small-diameter end of the second tapered pipe section.

[0008] The outer pipe comprises a third straight pipe section, a second tapered pipe section and a fourth straight pipe section which are integrally connected in sequence from back to front, the third straight pipe section is connected with the large-diameter end of the second tapered pipe section, and the fourth straight pipe section is connected with the small-diameter end of the second tapered pipe section.

[0009] A plate type positioning ring and a clamping flange are sequentially arranged on the outer wall of the connection between the second tapered pipe section and the fourth straight pipe section from back to front.

[0010] The application also has the following technical features:

[0011] Specifically, a first straight pipe section sealing bushing is arranged on the inner wall of the first straight pipe section, the first straight pipe section sealing bushing is connected with a transition sealing bushing, and a flange sealing bushing is arranged on the transition sealing bushing, and the front abutting surface of the flange sealing bushing is arranged in abutment with the abutting surface of the mounting flange.

[0012] Further, a plurality of first through holes are arranged on the mounting flange at equal intervals in the circumferential direction, and a plurality of second through holes are arranged on the plate type positioning ring at equal intervals in the circumferential direction, and the first through holes and the second through holes are arranged in pairs in symmetry.

[0013] Further, a first tapered pipe section sealing bushing is further connected to the front end of the first straight pipe section sealing bushing, and the first tapered pipe section sealing bushing is arranged in abutment with the first tapered pipe section.

[0014] Further, a first connecting tapered surface is arranged at the front end of the fourth straight pipe section.

[0015] Further, the materials of the first straight pipe section sealing bushing, the transition sealing bushing, the flange sealing bushing and the first tapered pipe section sealing bushing are all polytetrafluoroethylene.

[0016] Further, the sealed vacuum cavity is filled with a heat insulation material, and the heat insulation material comprises nano aerogel and ceramic fiber heat insulation material.

[0017] The application further discloses a construction method of the heat preservation pipeline, and the method comprises the following steps:

[0018] Step 1, according to the design, the wire along the tunnel side wall or the shaft roadway side is fixed, the construction position of the installation support is determined;

[0019] Step 2, the installation support is constructed;

[0020] Step 3, the multiple thermal insulation pipe units are transported to the installation position by means of the car washer or the rail car, then the multiple thermal insulation pipe units are placed on the support in sequence by the hoisting equipment, the adjacent thermal insulation pipe units are inserted and connected, then the installation flange 3, the flange sealing bush 7, the clamping flange 9 and the plate type positioning ring 8 are fastened together by bolts, and the inter-pipe fixing of the thermal insulation pipe unit is completed;

[0021] Step 4, each thermal insulation pipe unit is fixed on the support by the fixing ring, so that the movement and dislocation of the thermal insulation pipeline in the operation process are prevented, and finally the installation of the whole thermal insulation pipeline is completed;

[0022] Step 5, after the installation of the thermal insulation pipeline is completed, the water pressure test is carried out, the test time is not less than 30 min, the possible leakage points of the sealing are adjusted, finally the pipeline water pressure test is completed, and the construction is completed.

[0023] The application also protects the application of the above-mentioned thermal insulation pipeline for heat damage treatment in coal mine underground and tunnel.

[0024] Compared with the prior art, the application has the following technical effects:

[0025] The thermal insulation pipeline provided by the application is composed of a plurality of thermal insulation pipe units which can be detachably and sealingly connected, and the installation and disassembly are convenient. The thermal insulation pipe unit adopts a double-pipe structure, a sealing vacuum cavity is arranged between the inner pipe and the outer pipe, the sealing vacuum cavity has an ultra-low apparent thermal conductivity, the heat preservation performance of the thermal insulation pipe is greatly improved. A sealing bush made of polytetrafluoroethylene material with an extremely low thermal conductivity is arranged in the inner pipe. The thermal insulation pipes with the same structure can be connected by insertion and sealing connection by means of the sealing bush, so that the temperature can be reliably transmitted and the temperature is almost not lost, the pipe body is not easy to be damaged, and the thermal insulation pipeline has the characteristics of high temperature resistance, light weight, high mechanical strength and low apparent thermal conductivity. The thermal insulation pipeline provided by the application is especially suitable for the thermal insulation pipeline for heat damage treatment laid in coal mine underground and tunnels, and has great popularization and application value. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the application.

[0027] Meaning of reference signs:

[0028] 1-inner tube, 2-outer tube, 3-mounting flange, 4-seal vacuum cavity, 5-first straight tube section sealing bushing, 6-transition sealing bushing, 7-flange sealing bushing, 8-plate positioning ring, 9-detent flange, 10-first conical tube section sealing bushing; 11-first straight tube section, 12-first conical tube section, 13-second straight tube section; 21-third straight tube section, 22-second conical tube section, 23-fourth straight tube section, 31-first through hole, 81-second through hole; 231-first connecting conical surface. DETAILED DESCRIPTION

[0029] It should be understood that the detailed description herein is only used to illustrate and explain the present application, and is not used to limit the present application.

[0030] It should be noted that, unless otherwise specified, the parts used in the present application are commercially available.

[0031] The terms "upper", "lower", "front", "rear", "top", "bottom", etc. used in the present application indicate the orientation or positional relationship only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation. "Inner" and "outer" refer to the inner and outer contours of the corresponding components, and the above terms should not be understood as limiting the present application. The front, rear, etc. shown in the present application are described. Figure 1

[0032] In addition, the ordinal numbers "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0033] In the present application, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected or integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] Example 1

[0035] According to the above technical solution, as Figure 1 ​As shown, the embodiment provides a heat preservation pipe unit for downhole and tunnel heat damage treatment, which comprises a plurality of coaxially sealed heat preservation pipe units, the heat preservation pipe unit comprises an inner pipe 1 and an outer pipe 2 which are coaxially sleeved, the inner pipe 1 and the outer pipe 2 in the embodiment are both low-carbon steel pipe materials, and other materials can also be selected according to actual needs, the inner pipe 1 and the outer pipe 2 are both open at both ends, and one end of the inner pipe 1 protrudes from one end of the outer pipe 2, a mounting flange 3 is fixedly connected to the end of the inner pipe 1 protruding from the outer pipe 2, and a sealed vacuum cavity 4 is formed between the outer wall of the inner pipe 1, the side wall of the mounting flange 3 and the inner wall of the outer pipe 2; the shape of the sealed vacuum cavity is shown in the special-shaped structure, and the cross sections of the inner pipe 1 and the outer pipe 2 are both circular. Figure 1 As shown in the special-shaped structure, the cross sections of the inner pipe 1 and the outer pipe 2 are both circular.

[0036] The inner pipe 1 comprises a first straight pipe section 11, a first tapered pipe section 12 and a second straight pipe section 13 which are sequentially arranged from back to front, the first straight pipe section 11 is connected with the large-diameter end of the first tapered pipe section 12, and the second straight pipe section 13 is connected with the small-diameter end of the second tapered pipe section 12.

[0037] The outer pipe 2 comprises a third straight pipe section 21, a second tapered pipe section 22 and a fourth straight pipe section 23 which are integrally connected from back to front, the third straight pipe section 21 is connected with the large-diameter end of the second tapered pipe section 22, and the fourth straight pipe section 23 is connected with the small-diameter end of the second tapered pipe section 22.

[0038] The outer wall of the connection between the second tapered pipe section 22 and the fourth straight pipe section 23 is sequentially provided with a plate type positioning ring 8 and a clamping flange 9 from back to front.

[0039] As a preferred scheme of the embodiment, a first straight pipe section sealing bush 5 is attached to the inner wall of the first straight pipe section 11, the first straight pipe section sealing bush 5 is connected with a transition sealing bush 6, a flange sealing bush 7, and the front butt joint surface of the flange sealing bush 7 is attached to the butt joint surface of the mounting flange 3.

[0040] Preferably, the inner diameter of the first straight pipe section sealing bush 5 matches the outer diameter of the fourth straight pipe section 23.

[0041] As a preferred scheme of the embodiment, a plurality of first through holes 31 are equidistantly arranged on the mounting flange 3 in the circumferential direction, a plurality of second through holes 81 are equidistantly arranged on the plate type positioning ring 8 in the circumferential direction, the first through holes 31 and the second through holes 81 are symmetrically arranged two by two, and the plate type positioning ring 8 and the mounting flange 3 can be fixedly connected by bolts arranged in the through holes, or other components such as buckles can be used to achieve the axial fixed connection of the plate type positioning ring 8 and the mounting flange 3.

[0042] As a preferred form of the present embodiment, the front end of the first straight pipe section sealing bush 5 is further connected with a first conical pipe section sealing bush 10, which is arranged in close contact with the first conical pipe section 12.

[0043] As a preferred form of the present embodiment, the front end of the fourth straight pipe section 23 is provided with a first connecting conical surface 231, which can abut against the first conical pipe section sealing bush 10 of another thermal insulation pipe unit when the two thermal insulation pipe units are butted.

[0044] As a preferred form of the present embodiment, the first straight pipe section sealing bush 5, the transition sealing bush 6, the flange sealing bush 7 and the first conical pipe section sealing bush 10 are made of polytetrafluoroethylene, and other materials can also be selected according to actual construction needs.

[0045] As a preferred form of the present embodiment, the sealing vacuum cavity 4 is filled with thermal insulation materials, including nano aerogel and ceramic fiber thermal insulation materials.

[0046] In use, at least two thermal insulation pipe units are placed coaxially, and the first straight pipe section sealing bush 5 of one thermal insulation pipe unit is axially inserted into the fourth straight pipe section 23 of the adjacent thermal insulation pipe unit to realize the insertion fit between the adjacent thermal insulation pipe units; then the plate type positioning ring 8 is axially butted and fixed with the mounting flange 3 through bolts, thereby completing the connection and assembly of the thermal insulation pipeline.

[0047] Embodiment 2

[0048] The present embodiment discloses a construction method of a thermal insulation pipeline, which comprises the following steps:

[0049] Step 1, according to the design, lay out the points along the sidewall of the tunnel or the sidewall of the underground roadway, and determine the construction position of the mounting bracket;

[0050] Step 2, install the mounting bracket; the installation spacing of the mounting bracket should meet the design requirements, and the spacing should not be adjusted arbitrarily, and the installation should be firm to prevent loosening during operation and affecting normal operation;

[0051] Step 3, use a car washer or a rail car to transport a plurality of thermal insulation pipe units to the installation position, and then use hoisting equipment to place the plurality of thermal insulation pipe units on the bracket in sequence, and the adjacent thermal insulation pipe units are inserted and fitted, and then the mounting flange 3, the flange sealing bush 7, the clamping flange 9 and the plate type positioning ring 8 are fastened together by bolts, thereby completing the inter-pipe fixation of the thermal insulation pipe unit;

[0052] Step 4, fix each thermal insulation pipe unit on the bracket with a fixing ring to prevent the thermal insulation pipeline from moving out of position during operation; finally, the entire thermal insulation pipeline is installed;

[0053] After the installation of the heat preservation pipeline is completed, a water pressure test is performed, the test time is not less than 30 min, the possible leakage points of the sealing are adjusted, the water pressure test of the pipeline is finally completed, the construction is completed, and the heat preservation pipeline is put into use.

[0054] The heat preservation pipeline prepared by the method can be used for heat damage treatment in a coal mine underground and a tunnel.

[0055] In the process of conveying underground hot water, the heat preservation pipeline prepared by the method can reliably transmit temperature, the pipe body is not easy to be damaged, and has the characteristics of strong temperature resistance, light weight, high mechanical strength and low apparent thermal conductivity.

[0056] The above implementation process is only an example for clearly illustrating the present application, and is not a limitation on the implementation mode. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the implementation modes are not required or can not be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application type.

Claims

1. A construction method for an insulated pipe, characterized in that, The insulated pipe includes multiple insulated pipe units that can be coaxially and sealed together. Each insulated pipe unit includes an inner pipe (1) and an outer pipe (2) that are coaxially sleeved. Both the inner pipe (1) and the outer pipe (2) are open at both ends in the axial direction. One end of the inner pipe (1) extends out from one end of the outer pipe (2), and a mounting flange (3) is fixedly connected to the end of the inner pipe (1) that extends out from the outer pipe (2). A sealed vacuum cavity (4) is formed between the outer wall of the inner pipe (1), the side wall of the mounting flange (3), and the inner wall of the outer pipe (2). The inner pipe (1) includes a first straight pipe section (11), a first tapered pipe section (12), and a second straight pipe section (13) arranged from back to front; the first straight pipe section (11) is connected to the large-diameter end of the first tapered pipe section (12), and the second straight pipe section (13) is connected to the small-diameter end of the first tapered pipe section (12); The outer pipe (2) includes a third straight pipe section (21), a second tapered pipe section (22) and a fourth straight pipe section (23) that are integrally connected from back to front. The third straight pipe section (21) is connected to the large-diameter end of the second tapered pipe section (22), and the fourth straight pipe section (23) is connected to the small-diameter end of the second tapered pipe section (22). Plate positioning rings (8) and locking flanges (9) are arranged sequentially from back to front on the outer wall of the connection between the second tapered pipe section (22) and the fourth straight pipe section (23). A first straight pipe section sealing bushing (5) is attached to the inner wall of the first straight pipe section (11). The first straight pipe section sealing bushing (5) is connected to the flange sealing bushing (7) via a transition sealing bushing (6). The front mating surface of the flange sealing bushing (7) is attached to the mating surface of the mounting flange (3). The front end of the first straight pipe section sealing bushing (5) is also connected to the first tapered pipe section sealing bushing (10), and the first tapered pipe section sealing bushing (10) is fitted to the first tapered pipe section (12); The sealed vacuum cavity (4) is filled with heat insulation material, which includes nano-aerogel and ceramic fiber heat insulation material; The front end of the fourth straight pipe section (23) is provided with a first connecting cone surface (231); The method includes the following steps: Step 1: Lay out the lines along the tunnel sidewall or the sidewall of the underground roadway according to the design to determine the construction position of the support installation; Step 2: Install the support frame. Step 3: Transport multiple insulation pipe units to the installation location using a car wash or railcar, and then use lifting equipment to place multiple insulation pipe units onto the bracket in sequence. Adjacent insulation pipe units are plugged in and matched, and then use bolts to fasten the mounting flange (3), flange sealing bushing (7), locking flange (9) and plate positioning ring (8) together to complete the pipe fixing of the insulation pipe units. Step 4: Secure each insulation pipe unit to the bracket using fixing rings to prevent the insulation pipe from moving or misaligning during operation; finally, complete the installation of the entire insulation pipe. Step 5: After the insulation pipe is installed, conduct a water pressure test for no less than 30 minutes. Adjust any leaks that may exist in the seal, and finally complete the water pressure test. The construction is then complete.

2. The construction method for the insulated pipeline as described in claim 1, characterized in that, The mounting flange (3) is provided with a plurality of first through holes (31) at equal intervals along the circumference, and the plate positioning ring (8) is provided with a plurality of second through holes (81) at equal intervals along the circumference. The first through holes (31) and the second through holes (81) are arranged symmetrically in pairs.

3. The construction method for the insulated pipeline as described in claim 1, characterized in that, The first straight pipe section sealing bushing (5), transition sealing bushing (6), flange sealing bushing (7) and the first tapered pipe section sealing bushing (10) are all made of polytetrafluoroethylene.

4. The construction method of the insulated pipeline as described in any one of claims 1 to 3 is used for the application of insulated pipelines for heat hazard control in underground coal mines and tunnels.

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