Multi-layer composite structure metal hose and application thereof

Abstract

The invention discloses a multi-layer composite structure metal hose and application thereof, and belongs to the technical field of pipeline conveying. The multi-layer composite structure metal hose is composed of a corrosion-resistant flexible inner layer, a composite heat insulation middle layer and a pressure-bearing protection outer layer from inside to outside. The composite heat insulation middle layer is composed of an inner side reflection heat insulation layer, a middle body heat insulation layer and an outer side buffering heat insulation layer from inside to outside. Through the three-layer structural design of the corrosion-resistant inner pipe, the composite heat insulation layer and the pressure-bearing outer net, multifunctional integration and performance collaboration are achieved, the corrosion-resistant function, the flexible compensation function, the efficient heat insulation function and the mechanical pressure-bearing function are decomposed and borne by different layers, and the comprehensive performance which is difficult to reach by a single component is achieved. All the layers work cooperatively, the inner layer focuses on corrosion prevention and flexibility, the middle layer efficiently isolates heat, the outer layer bears pressure in a relatively low-temperature environment, and the contradiction between performance is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pipeline transportation, and particularly relates to a multi-layer composite structure metal hose and application thereof. BACKGROUND

[0002] In the fields of energy chemical industry such as coal chemical industry and natural gas conversion, and metallurgy such as gas-based shaft furnace direct reduction of iron, the transportation of high-temperature synthesis gas (main components are H2 and CO, containing CO2, H2O and a small amount of H2S and other impurities) is a key technical link. The synthesis gas usually has characteristics such as high temperature (up to 800℃ or above), high pressure, strong reducing property and corrosiveness.

[0003] In the prior art, ordinary metal hoses are difficult to work for a long time under such extreme working conditions: the inner layer material is prone to corrosion such as high-temperature oxidation, carburization and sulfidation, resulting in failure; the insufficient heat insulation performance leads to large heat loss and excessively high outer wall temperature; the strength of the pressure-bearing component significantly decays at high temperature. Although there are some improved designs, there are still problems such as single structure and function, inability to balance various performances, and short service life.

[0004] Therefore, it is urgent to develop a special metal hose that can simultaneously meet the multiple requirements of high-temperature corrosion resistance, flexible connection, reliable pressure bearing and high-efficiency heat insulation.

[0005] The information disclosed in this BACKGROUND section is only intended to increase an understanding of the general context of the present application and is not to be taken in any way as an acknowledgment or any form of suggestion that this information forms the prior art that is already known to those of ordinary skill in the art. SUMMARY

[0006] In order to solve the technical problems that the existing metal hoses are difficult to simultaneously have corrosion resistance, high-temperature resistance and pressure resistance, a multi-layer composite structure metal hose and application thereof are provided.

[0007] The present application provides a multi-layer composite structure metal hose in the first aspect, which is composed of a corrosion-resistant flexible inner layer, a composite heat insulation intermediate layer and a pressure-bearing protective outer layer from inside to outside. The composite heat insulation intermediate layer is composed of an inner side reflective heat insulation layer, an intermediate main body heat insulation layer and an outer side buffer heat insulation layer from inside to outside.

[0008] In some embodiments, the corrosion-resistant flexible inner layer is a metal bellows, and the material of the metal bellows is a nickel-based or iron-nickel-based high-temperature alloy.

[0009] In some embodiments, the inner side reflective heat insulation layer is a nanofiber blanket wrapped on the outer surface of the metal bellows, and the inner surface of the inner side reflective heat insulation layer in contact with the metal bellows is coated with a heat reflective coating.

[0010] In some embodiments, the heat reflective coating has a reflectivity of not less than 80% in the infrared wave band.

[0011] In some embodiments, the intermediate main body thermal insulation layer is an alumina fiber layer wrapped outside the inner reflective thermal insulation layer, the alumina fiber has a maximum use temperature of not less than 1260℃ and a thermal conductivity of not higher than 0.28 W / (m·K) at 1000℃.

[0012] In some embodiments, the outer layer buffer thermal insulation layer is a nanofiber blanket wrapped outside the intermediate main body thermal insulation layer, the nanofiber blanket has a thermal conductivity of not higher than 0.055 W / (m·K) at 600℃ and a maximum use temperature of not less than 800℃.

[0013] In some embodiments, the pressure-bearing protective outer layer is an austenitic stainless steel wire woven mesh sleeve wrapped outside the composite thermal insulation intermediate layer, and the woven structure is a single-layer, double-layer or triple-layer mesh sleeve.

[0014] The second aspect of the present application provides an application of a multi-layer composite structure metal hose in a high-temperature, high-pressure and high-corrosive gas ring.

[0015] Compared with the prior art, the present application achieves the following technical effects: (1) Multi-functional integration and performance synergy: Through the three-layer structure design of "corrosion-resistant inner tube + composite thermal insulation layer + pressure-bearing outer mesh", the functions of corrosion resistance, flexibility compensation, high-efficiency thermal insulation and mechanical pressure bearing are decomposed and borne by different layers, realizing the comprehensive performance that a single component cannot achieve. The layers work synergistically, the inner layer focuses on corrosion prevention and flexibility, the intermediate layer efficiently insulates heat, and the outer layer bears pressure in a relatively low temperature environment, solving the contradiction between performance.

[0016] (2) Excellent high-temperature durability: The inner layer is made of an alloy material specially resistant to high-temperature synthesis gas corrosion, which fundamentally improves the service life of the hose main body. The composite thermal insulation layer effectively reduces the temperature transmitted to the outer mesh sleeve, avoiding the problem of rapid strength decrease of the outer metal material at high temperature, and ensuring the pressure-bearing reliability.

[0017] (3) High-efficiency thermal insulation and energy saving: The unique "reflection combined with barrier" composite thermal insulation structure (reflection coating combined with nanofiber blanket and alumina fiber layer) greatly inhibits heat radiation and heat conduction, significantly reduces the heat loss of the pipeline system, improves the energy utilization efficiency, and at the same time ensures that the outer wall temperature is within a safe range to prevent burns.

[0018] (4) Wide application potential: This design is particularly suitable for harsh working conditions such as coal gasification, IGCC, synthesis gas transportation, reforming device, etc. which exist in high-temperature corrosive medium and require flexible connection, and has broad market application prospect and significant economic benefit. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 This is a schematic diagram of the axial cross-sectional structure of the multi-layer composite metal hose in one embodiment of the present invention; Figure 2 This is a schematic diagram of the transverse cross-section of a multi-layer composite metal hose according to one embodiment of the present invention.

[0020] In the diagram: 1-Metal corrugated pipe; 2-Heat reflective coating; 3-Composite thermal insulation intermediate layer; 31 / 33-Nanofiber blanket; 32-Alumina fiber; 4-Metal wire woven mesh sleeve; 5-Insulation cotton; 6-Pipe sleeve. Detailed Implementation

[0021] The technical solution of the present invention will be described below with reference to the accompanying drawings and specific embodiments. It should be understood that the existence of other methods and steps before and after the combined steps, or the insertion of other methods and steps between these explicitly mentioned steps, does not preclude the use of one or more steps mentioned in the present invention. It should also be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise stated, the numbering of each method step is for the purpose of identifying each method step, and is not intended to limit the order of each method or limit the scope of the invention. Changes or adjustments to their relative relationships, without substantial changes to the technical content, can also be considered within the scope of the invention.

[0022] The raw materials and instruments used in the examples are not subject to any specific restrictions on their source; they can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0023] like Figure 1 and Figure 2 As shown, a multi-layer composite metal hose is composed of a corrosion-resistant flexible inner layer, a composite heat-insulating intermediate layer 3, and a pressure-bearing protective outer layer from the inside out.

[0024] In one embodiment, the corrosion-resistant flexible inner layer is a metal bellows 1 that is in direct contact with the syngas. The metal bellows 1 is made of a high-temperature alloy resistant to high temperatures and reducing atmosphere corrosion, such as a nickel-based or iron-nickel-based high-temperature alloy. Preferred models include, but are not limited to, N08330 (Incoloy 330 / RA330), GH4099, GH1140, GH3625 (Inconel 625), or Incoloy 800 series alloys. These alloys share the common characteristic of excellent resistance to oxidation, carburization, and sulfidation at high temperatures. The waveform of the metal bellows 1 is U-shaped, Ω-shaped, or S-shaped, and its wall thickness, wave height, and wave pitch are designed according to the required flexibility, compensation amount, and pressure rating.

[0025] In an embodiment, the composite heat insulation intermediate layer 3 is a multi-layer insulation structure wrapped outside the metal bellows 1, which is composed of an inner reflective insulation layer, an intermediate main insulation layer, and an outer buffer insulation layer from inside to outside, specifically: The inner reflective insulation layer is a nanofiber blanket 31 wrapped on the outer surface of the metal bellows, and the inner surface in contact with the metal bellows is coated with a high-reflectivity heat-reflecting paint 2. The intermediate main insulation layer is an alumina fiber layer 32 wrapped outside the inner reflective insulation layer. The outer buffer insulation layer is a nanofiber blanket 33 wrapped outside the intermediate main insulation layer, and its outer surface is in contact with the pressure-bearing protective outer layer.

[0026] Preferably, the heat-reflecting paint 2 coated on the inner reflective insulation layer has a reflectivity in the infrared band not less than 80%, preferably not less than 90%. Preferably, the infrared-reflecting paint is a high-temperature nanofunctional film material with anti-infrared radiation. The high-temperature nanofunctional film material is made of ZrO2 and TiO2 as raw materials, doped with rare earth elements such as Y, Sm, Ho, and Ce. The molar ratio of ZrO2 to TiO2 is 1:1-5, and other ions such as Y2O3 are doped for auxiliary / neutralization phase change / control functions to form a stable ZrO2 / Y2O3 system. The proportion of rare earth elements is about 3%-10% by weight for high-temperature stability control, so that ZrO2 can be used continuously at 1200°C to 1600°C. The doping concentration is generally less than 10%wt, such as introducing Y into TiO2 to improve catalytic activity, which usually accounts for 3%-10% of the Ti source. The focus is on anti-radiation, which reduces heat loss and reduces the requirement for temperature resistance of the pressure-bearing outer pipe, preventing the risk of hose failure.

[0027] Preferably, the nanofiber blanket 31 / 33 used in the inner reflective insulation layer and the outer buffer insulation layer has a thermal conductivity not higher than 0.055 W / (m·k) at 600°C, and a maximum use temperature not lower than 800°C.

[0028] Preferably, the alumina fiber layer 32 used in the intermediate main insulation layer has a maximum use temperature not lower than 1260°C, and a thermal conductivity not higher than 0.28 W / (m·K) at 1000°C.

[0029] In an embodiment, the pressure-bearing protective outer layer is a stainless steel wire mesh sleeve 4 wrapped outside the composite heat insulation intermediate layer. Preferably, the pressure-bearing protective outer layer is woven from austenitic stainless steel wire, preferably 304, 321, or 316L stainless steel, and the woven structure is a single-layer, double-layer, or triple-layer mesh sleeve, selected according to the design pressure.

[0030] In an embodiment, a heat insulation cotton 5 can be further arranged between the metal wire braided mesh sleeve 4 and the composite heat insulation intermediate layer to increase the high temperature resistance and durability; during use, the pipe sleeve 6 can be fixedly connected with the corresponding pipeline.

[0031] The multi-layer composite structure metal hose provided by the application can be applied to high-temperature, high-pressure and high-corrosion gas environments, such as coal gasification, natural gas conversion, synthetic gas transportation or reforming device pipeline systems Embodiment 1 A multi-layer metal hose for high-temperature synthetic gas pipeline connection of a coal gasification device.

[0032] The corrosion-resistant flexible inner layer is a U-shaped bellows made of N08330 (UNS N08330) high-temperature alloy, with a wall thickness of 0.8 mm.

[0033] The composite heat insulation intermediate layer is wrapped outside the bellows: The inner reflective heat insulation layer is an aluminum silicate nanofiber blanket with a thickness of 3 mm, and the inner surface is coated with a ceramic-based reflective coating with a thermal reflectivity of ≥90%, with a dry film thickness of about 0.2 mm; The intermediate main heat insulation layer is an alumina fiber blanket with a thickness of 10 mm and a density of 128 kg / m³; The outer buffer heat insulation layer is an aluminum silicate nanofiber blanket with a thickness of 2 mm.

[0034] The pressure-bearing protective outer layer is a double-layer mesh sleeve woven with 316L stainless steel wires, with a design working pressure of 4.0 MPa.

[0035] The hose is designed for transporting synthetic gas with a temperature of ≤800℃ and a pressure of ≤2.5 MPa, and is expected to have a service life that is more than 3 times longer than that of traditional hoses, with an outer wall temperature that can be controlled below 100℃.

[0036] Embodiment 2 A multi-layer metal hose for the outlet of a natural gas conversion furnace of a gas-based shaft furnace direct reduced iron process.

[0037] The corrosion-resistant flexible inner layer is an Ω-shaped bellows made of GH3625 (Inconel 625) nickel-based alloy, with a wall thickness of 1.0 mm.

[0038] The composite heat insulation intermediate layer: The inner reflective heat insulation layer is an alumina nanofiber blanket with a thickness of 4 mm, coated with a silicone-acrylate resin-based reflective coating with a thermal reflectivity of ≥92%; The intermediate main heat insulation layer is an alumina fiber board with a thickness of 15 mm and a density of 96 kg / m³; The outer buffer heat insulation layer is an alumina nanofiber blanket with a thickness of 3 mm.

[0039] The pressure-bearing protective outer layer adopts a three-layer mesh cover woven by 321 stainless steel wires, and the design working pressure is 6.4 MPa.

[0040] The hose is designed for conveying reducing gas with a temperature of ≤950 DEG C and a pressure of ≤4.0 MPa, and has good thermal shock resistance and fatigue life.

[0041] The three-layer structure design of the corrosion-resistant inner tube, the composite heat insulation layer and the pressure-bearing outer mesh decomposes and bears the functions of corrosion resistance, flexibility compensation, high-efficiency heat insulation and mechanical pressure bearing by different layers, realizes the comprehensive performance that a single component cannot achieve, and solves the contradiction between the performance. The inner layer focuses on corrosion prevention and flexibility, the middle layer efficiently insulates heat, and the outer layer bears pressure in a relatively low temperature environment. The inner layer is made of an alloy material specially resistant to high-temperature syngas corrosion, which fundamentally improves the service life of the hose body. The composite heat insulation layer effectively reduces the temperature transferred to the outer mesh, avoids the problem of sharp decrease of the strength of the outer metal material under high temperature, and guarantees the pressure-bearing reliability. The unique composite heat insulation structure of reflection combined with blocking (reflection coating, nanofiber blanket and alumina fiber layer) greatly inhibits heat radiation and heat conduction, significantly reduces the heat loss of the pipeline system, improves the energy utilization efficiency, and ensures that the outer wall temperature is within a safe range to prevent burns.

[0042] The present application is particularly suitable for harsh working conditions such as coal gasification, IGCC, syngas transportation, reforming device, etc. The foregoing description of specific exemplary embodiments of the application is intended to be illustrative only and is not intended to limit the application to the precise forms described. Many modifications and variations are possible in light of the above teachings without departing from the spirit or essential characteristics of the application. The exemplary embodiments were chosen and described in order to explain the principles of the application and its practical application and to allow others skilled in the art to understand the application for various exemplary embodiments with various modifications being made to the application that are suited to the particular use contemplated. It is intended that the scope of the application be defined by the claims and their equivalents.

Claims

1. A multilayer composite construction metal hose characterized by, It is composed of corrosion-resistant flexible inner layer, composite heat insulation middle layer and pressure-bearing protective outer layer from inside to outside. The composite heat insulation middle layer is composed of inner side reflective heat insulation layer, middle main body heat insulation layer and outer side buffer heat insulation layer from inside to outside.

2. The multilayer composite structure metal hose according to claim 1, characterized by, The corrosion-resistant flexible inner layer is a metal bellows, and the material of the metal bellows is nickel-based or iron-nickel-based high-temperature alloy.

3. The multilayer composite structure metal hose according to claim 2, characterized by, The inner side reflective heat insulation layer is a nanofiber blanket wrapped on the outer surface of the metal bellows, and the inner surface of the inner side reflective heat insulation layer in contact with the metal bellows is coated with heat reflective paint.

4. The multilayer composite structure metal hose according to claim 3, characterized by, The heat reflective paint has a reflectivity of not less than 80% in the infrared wave band.

5. The multilayer composite structure metal hose according to claim 2, wherein, The middle main body heat insulation layer is an alumina fiber layer wrapped on the outer side of the inner side reflective heat insulation layer, and the alumina fiber has a highest use temperature of not less than 1260 DEG C and a thermal conductivity of not higher than 0.28 W / (m·K) at 1000 DEG C.

6. The multilayer composite structure metal hose according to claim 2, wherein, The outer side buffer heat insulation layer is a nanofiber blanket wrapped on the outer side of the middle main body heat insulation layer, and the nanofiber blanket has a thermal conductivity of not higher than 0.055 W / (m·K) at 600 DEG C and a highest use temperature of not less than 800 DEG C.

7. The multilayer composite construction metal hose of claim 1, wherein, The pressure-bearing protective outer layer is an austenitic stainless steel wire braided mesh sleeve wrapped on the outer side of the composite heat insulation middle layer, and the braided structure is a single-layer, double-layer or three-layer mesh sleeve.

8. Application of the multilayer composite structure metal hose according to any one of claims 1-7 to a high-temperature, high-pressure and high-corrosion gas environment.

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