Cold insulation structure for on-line construction of low-temperature natural gas pipeline

Abstract

The utility model discloses an online construction cold insulation structure for a low-temperature natural gas pipeline. The pipeline sequentially comprises a pipeline base material from inside to outside; the primer layer is brushed on the surface of the pipeline base material and is used for improving the corrosion resistance of the pipeline base material; the cold insulation layer covers the exterior of the primer layer and is used for cold insulation and moisture insulation; the anti-cracking net layer wraps the cold insulation layer and is used for wrapping and fixing the cold insulation layer; the thick slurry type fiber flame-retardant heat-preservation coating layer is painted on the outer part of the expanding and cracking steel mesh layer and is used for sealing gaps of the expanding and cracking steel mesh layer; and the finish paint layer is brushed outside the high-build fiber flame-retardant thermal-insulation coating layer and is used for reducing blackness and preventing heat absorption. The low-temperature natural gas pipeline has the advantages that the low-temperature natural gas pipeline sequentially comprises the pipeline base material, the primer layer, the cold insulation layer, the anti-cracking net layer, the thick fiber flame-retardant heat preservation coating layer and the finish paint layer from inside to outside, and the low-temperature natural gas pipeline can be prevented from being corroded due to surface condensation by means of the overall film forming property of the coatings.

Description

Technical Field

[0001] The utility model relates to the technical field of pipeline cold preservation, in particular to a low-temperature natural gas pipeline online construction cold preservation structure. Background Art

[0002] When the pipeline is transporting low-temperature natural gas without reasonable cooling measures, the outer wall temperature is lower than the ambient dew point temperature, and condensation will occur on the surface. The condensed water will accelerate the failure of the external anti-corrosion coating, and then cause metal corrosion. Under certain circumstances, the spread of condensed water will make the surrounding environment slippery, breed moss, affect the appearance, and even pose a safety hazard.

[0003] At present, the most common method for treating condensation on the surface of low-temperature natural gas pipelines is to cover them with cold insulation materials. However, unreasonable cold insulation structures will leave joints, and water vapor will continuously enter the cold insulation layer through the joints, eventually causing the cold insulation structure to fail. In addition, the online cold insulation construction of low-temperature natural gas pipelines has always been a difficult problem that has troubled relevant practitioners. Directly sealing the condensed water on the surface of the pipeline under the cold insulation layer without protective measures will cause corrosion under the insulation layer. Due to the obstruction of the cold insulation layer, the corrosion risk cannot be directly eliminated by visual inspection. After a long period of corrosion development, it will eventually cause safety accidents such as leakage. Utility Model Content

[0004] The utility model aims to provide a cold-insulation structure for online construction of a low-temperature natural gas pipeline, which comprises, from the inside out, a pipeline substrate, a primer layer, a cold-insulation layer, an anti-cracking mesh layer, a thick-paste fiber flame-retardant thermal insulation coating layer and a topcoat layer, and utilizes the overall film-forming property of the coating to prevent the low-temperature natural gas pipeline from being corroded due to surface condensation.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions, which include from inside to outside:

[0006] Pipe substrate;

[0007] A primer layer, which is applied on the surface of the pipeline substrate to improve the anti-corrosion performance of the pipeline substrate;

[0008] A cold-insulating layer, which is coated on the outside of the primer layer and is used for cold-insulating and moisture-proofing; and an anti-cracking mesh layer, which is coated on the outside of the cold-insulating layer and is used for wrapping and fixing the cold-insulating layer;

[0009] A thick-paste fiber flame-retardant thermal insulation coating layer, which is applied to the outside of the anti-cracking mesh layer and is used to seal the gap between the cold insulation layer and the anti-cracking mesh layer;

[0010] The topcoat layer is applied on the outside of the thick-paste fiber flame-retardant thermal insulation coating layer to reduce the blackness and prevent heat absorption.

[0011] Preferably, an intermediate paint layer for continuous transition is provided between the thick-paste fiber flame-retardant thermal insulation coating layer and the top paint layer.

[0012] Preferably, the thick-paste fiber flame-retardant thermal insulation coating layer includes, from the inside to the outside, a first thick-paste fiber flame-retardant thermal insulation coating layer and a second thick-paste fiber flame-retardant thermal insulation coating layer; a fiber mesh layer for increasing strength is provided between the first thick-paste fiber flame-retardant thermal insulation coating layer and the second thick-paste fiber flame-retardant thermal insulation coating layer.

[0013] Preferably, the thickness of the primer layer is 150-300 μm; the thickness of the cold insulation layer is 5-20 mm; the thickness of the anti-cracking mesh layer is 1.1-1.3 mm; the thickness of the first thick-paste type fiber flame-retardant thermal insulation coating layer is 1.4-1.6 mm; the thickness of the fiber mesh layer is 0.4-0.6 mm; the thickness of the second thick-paste type fiber flame-retardant thermal insulation coating layer is 1.4-1.6 mm; the thickness of the intermediate paint layer is 80-200 μm; and the thickness of the topcoat layer is 80-150 μm.

[0014] Preferably, the cold insulation layer is made of any one of rock wool, glass wool, aluminum silicate, rubber plastic, silicate, polyurethane, aerogel, porous vacuum silicon, foam glass, polyisocyanurate, polyurethane, and polystyrene.

[0015] The beneficial effects of the utility model are as follows: from the inside out, it includes a pipeline substrate, a primer layer, a cold insulation layer, an anti-cracking mesh layer, a thick pulp fiber flame retardant thermal insulation coating layer and a topcoat layer, and utilizes the overall film-forming property of the coating to prevent low-temperature natural gas pipelines from being corroded due to surface condensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a stereoscopic diagram of a cold-insulation structure for online construction of a low-temperature natural gas pipeline according to the utility model.

[0017] Figure 2 It is a cross-sectional view of a cold-insulation structure for online construction of a low-temperature natural gas pipeline according to the utility model. DETAILED DESCRIPTION

[0018] The utility model is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0019] It should be understood that terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or other elements or combinations thereof.

[0020] like Figure 1-2 As shown, a low-temperature natural gas pipeline online construction cold preservation structure 1 of the utility model comprises:

[0021] Pipe substrate 110 .

[0022] The primer layer 120 is applied on the surface of the pipeline substrate 110 to improve the anti-corrosion performance of the pipeline substrate 110; preferably, the thickness of the primer layer 120 is 150 to 300 μm; further preferably, the primer layer is a modified epoxy coating.

[0023] The cold insulation layer 130 is coated on the outside of the primer layer for cold insulation and moisture insulation. Preferably, the thickness of the cold insulation layer 130 is 5 to 20 mm; more preferably, the cold insulation layer 130 is made of any one of rock wool, glass wool, aluminum silicate, rubber plastic, silicate, polyurethane, aerogel, porous vacuum silicon, foam glass, polyisocyanurate, polyurethane, and polystyrene.

[0024] The anti-cracking mesh layer 140 is a steel mesh or a fiber mesh, which is coated on the outside of the cold insulation layer 130 and is used to wrap and fix the cold insulation layer 130; as a preferred embodiment, the thickness of the crack-expanding steel mesh layer 140 is 1.1-1.3 mm; as a further preferred embodiment, the thickness of the crack-expanding steel mesh layer 140 is 1.2 mm.

[0025] The thick-paste fiber flame-retardant thermal insulation coating layer 150 is brushed on the outside of the anti-cracking mesh layer 140 to seal the gaps of the anti-cracking mesh layer 140. Preferably, the thick-paste fiber flame-retardant thermal insulation coating layer 150 includes, from the inside to the outside, a first thick-paste fiber flame-retardant thermal insulation coating layer 151 and a second thick-paste fiber flame-retardant thermal insulation coating layer 152; a fiber mesh layer 153 for increasing strength is provided between the first thick-paste fiber flame-retardant thermal insulation coating layer 151 and the second thick-paste fiber flame-retardant thermal insulation coating layer 152. Further preferably, the thickness of the first thick-paste fiber flame-retardant thermal insulation coating layer 151 is 1.4 to 1.6 mm; the thickness of the fiber mesh 153 layer is 0.4 to 0.6 mm; the thickness of the second thick-paste fiber flame-retardant thermal insulation coating layer 152 is 1.4 to 1.6 mm.

[0026] The topcoat layer 170 is applied on the outside of the thick-paste fiber flame-retardant coating layer 150 to reduce the blackness and prevent heat absorption. As a preferred embodiment, an intermediate paint layer 160 for continuous transition is provided between the thick-paste fiber flame-retardant thermal insulation coating layer 150 and the topcoat layer 170. As a further preferred embodiment, the thickness of the intermediate paint layer 160 is 80 to 200 μm; the thickness of the topcoat layer 170 is 80 to 150 μm.

[0027] During use, formulate a corresponding surface treatment method according to the coating status of the pipeline substrate 110 in the construction area: for coatings with good anti-corrosion performance and apparent flowery areas, remove oil, salt, dust and other debris from the surface and then roughen the entire surface; for coating failure areas, pre-treat the substrate surface in accordance with the requirements of the project specification. Use clean water with anti-flash rust agent added to rinse the remaining paint particles and rust residue on the surface, and wipe off the liquid water on the surface; 3) Apply a primer layer 120 with a thickness of 150 to 300 μm on the outside of the pipeline substrate 110; after the primer layer 120 is completely cured, after verifying that there are no missing points through a missing point test, wipe off the liquid water on the surface, and cover the cold insulation layer 130 with a thickness of 5 to 20 mm; use an anti-cracking mesh layer 140 with a thickness of 1.1 to 1.3 mm to reinforce the cold insulation layer 130; then apply a first thick slurry type fiber resistance with a thickness of 1.4 to 1.6 mm on the surface of the anti-cracking mesh layer 140. A flame retardant thermal insulation coating layer 151 is provided; when the first thick paste type fiber flame retardant thermal insulation coating layer 151 reaches surface dry, a fiber mesh layer 153 is wrapped on the surface of the first thick paste type fiber flame retardant thermal insulation coating layer 151; a second thick paste type fiber flame retardant thermal insulation coating layer 152 with a thickness of 1.4 to 1.6 mm is coated on the surface of the fiber mesh layer 153; after the second thick paste type fiber flame retardant thermal insulation coating layer 152 reaches complete dryness, an intermediate paint layer 160 with a thickness of 80 to 200 μm is sprayed on the surface; a top paint layer 170 with a thickness of 80 to 150 μm is sprayed outside the intermediate paint layer 160.

[0028] In another embodiment, an intermediate paint layer 160 for continuous transition is provided between the thick-paste fiber flame-retardant thermal insulation paint layer 150 and the topcoat layer 170. Preferably, the intermediate paint layer 160 is a penetrating epoxy sealing paint. The topcoat layer 170 is an aliphatic polyurethane topcoat with rutile titanium dioxide as filler.

[0029] In another embodiment, the thick paste type fiber flame retardant thermal insulation coating layer 150 includes, from the inside to the outside, a first thick paste type fiber flame retardant thermal insulation coating layer 151 and a second thick paste type fiber flame retardant thermal insulation coating layer 152; a fiber mesh layer 153 for increasing strength is provided between the first thick paste type fiber flame retardant thermal insulation coating layer 151 and the second thick paste type fiber flame retardant thermal insulation coating layer 152.

[0030] In another embodiment, the thickness of the primer layer 120 is 150-300 μm; the thickness of the cold insulation layer 130 is 5-20 mm; the thickness of the anti-cracking mesh layer 140 is 1.1-1.3 mm; the thickness of the first thick-paste fiber flame-retardant thermal insulation coating layer 151 is 1.4-1.6 mm; the thickness of the fiber mesh layer 153 is 0.4-0.6 mm; the thickness of the second thick-paste fiber flame-retardant thermal insulation coating layer 152 is 1.4-1.6 mm; the thickness of the intermediate paint layer 160 is 80-200 μm; the thickness of the topcoat layer 170 is 80-150 μm.

[0031] In another embodiment, the cold insulation layer 130 is made of any one of rock wool, glass wool, aluminum silicate, rubber plastic, silicate, polyurethane, aerogel, porous vacuum silicon, foam glass, polyisocyanurate, polyurethane, and polystyrene.

[0032] In summary, the utility model provides an online cold insulation structure 1 for low-temperature natural gas pipelines, which includes a pipeline substrate, a primer layer, a cold insulation layer, an anti-cracking mesh layer, a thick-paste fiber flame-retardant thermal insulation coating layer and a topcoat layer from the inside out. The overall film-forming property of the coating can prevent the low-temperature natural gas pipeline from being corroded due to surface condensation.

[0033] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A low-temperature natural gas pipeline online construction cold insulation structure, characterized in that: From inside to outside, it includes: Pipe substrate; A primer layer, which is applied on the surface of the pipeline substrate to improve the anti-corrosion performance of the pipeline substrate; A cold-insulating layer, which is coated on the outside of the primer layer and is used for keeping cold and moisture-proof; and An anti-cracking mesh layer, which is coated on the outside of the cold insulation layer and is used to wrap and fix the cold insulation layer; A thick-paste fiber flame-retardant thermal insulation coating layer, which is applied to the outside of the anti-cracking mesh layer and is used to seal the gap between the cold insulation layer and the anti-cracking mesh layer; The topcoat layer is applied on the outside of the thick-paste fiber flame-retardant thermal insulation coating layer to reduce the blackness and prevent heat absorption.

2. The low-temperature natural gas pipeline online construction cold insulation structure according to claim 1 is characterized by: An intermediate paint layer for continuous transition is provided between the thick-paste fiber flame-retardant thermal insulation paint layer and the topcoat layer.

3. The low-temperature natural gas pipeline online construction cold insulation structure according to claim 2 is characterized by: The thick-paste fiber flame-retardant thermal insulation coating layer includes, from the inside to the outside, a first thick-paste fiber flame-retardant thermal insulation coating layer and a second thick-paste fiber flame-retardant thermal insulation coating layer; a fiber mesh layer for increasing strength is provided between the first thick-paste fiber flame-retardant thermal insulation coating layer and the second thick-paste fiber flame-retardant thermal insulation coating layer.

4. The low-temperature natural gas pipeline online construction cold insulation structure according to claim 3 is characterized by: The thickness of the primer layer is 150 to 300 μm; the thickness of the cold insulation layer is 5 to 20 mm; the thickness of the anti-cracking mesh layer is 1.1 to 1.3 mm; the thickness of the first thick-paste fiber flame-retardant thermal insulation coating layer is 1.4 to 1.6 mm; the thickness of the fiber mesh layer is 0.4 to 0.6 mm; the thickness of the second thick-paste fiber flame-retardant thermal insulation coating layer is 1.4 to 1.6 mm; the thickness of the intermediate paint layer is 80 to 200 μm; and the thickness of the top paint layer is 80 to 150 μm.

5. The low-temperature natural gas pipeline online construction cold insulation structure according to claim 1 is characterized by: The cold insulation layer is made of any one of rock wool, glass wool, rubber plastic, silicate, polyurethane, aerogel, porous vacuum silicon, foam glass, polyisocyanurate, and polystyrene.

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