Graphene composite heat transfer tube

Abstract

The utility model belongs to the technical field of petrochemical industry and coal chemical industry energy conservation, and particularly discloses a graphene composite heat transfer pipe, which comprises a metal base pipe and a graphene composite layer wrapped outside the metal base pipe, has the advantages of high mechanical strength, good heat transfer performance, strong corrosion resistance and the like, and overcomes the defects of large heat transfer resistance and the like caused by large wall thickness of a graphite composite pipe. The graphene composite pipe overcomes the defects that a pure graphene pipe is difficult to form, high in price and the like, is simple in production process and convenient to operate, can resist acid dew point corrosion of low-temperature flue gas due to the fact that air is not corrosive, an air medium circulates in the composite pipe and the outer wall of the composite pipe is made of the graphene composite material when the graphene composite pipe is used as a heat transfer pipe of an air preheater, and has a good application prospect.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy conservation in petrochemical industry and coal chemical industry, and specifically discloses a graphene composite heat transfer pipe. Background Art

[0002] At present, the air preheaters used in low-temperature waste heat recovery systems in the petrochemical, coal chemical and other industries are generally made of metal or non-metallic graphite, glass or ceramics. When the flue gas is corrosive, it will cause corrosion damage to the metal heat transfer elements of the air preheater, which cannot meet the use requirements. Non-metallic graphite, glass and ceramic heat transfer elements have good corrosion resistance, but they are all brittle materials with insufficient mechanical strength. They are easily affected by thermal stress during use and deformed, which in turn causes damage to the heat transfer elements.

[0003] The existing graphite metal composite tube is a kind of air preheater heat transfer tube that is both corrosion-resistant and has certain heat transfer performance. However, due to the thick composite material and large thermal resistance, the heat transfer performance of the graphite composite tube is affected. In addition, the brittleness of the graphite composite material is also large, which makes the installation, transportation and application of the graphite composite tube have the risk of damage, thus affecting its application in low-temperature air preheaters.

[0004] Graphene is an excellent corrosion-resistant material with superb thermal conductivity, with a thermal conductivity of 1500-5100 W / (m·K). However, graphene alone is not suitable for directly making heat transfer elements for low-temperature air preheaters due to factors such as the extremely high price of graphene materials and the difficulty in molding. Summary of the invention

[0005] In order to solve the problems in the background technology, the utility model discloses a graphene composite heat transfer pipe, including a metal base pipe and a graphene composite layer, which has high strength, good toughness, corrosion resistance, good heat transfer performance, and can resist acid dew point corrosion of low-temperature flue gas.

[0006] In order to achieve the above-mentioned invention object, the utility model adopts the following technical solutions:

[0007] A graphene composite heat transfer tube comprises a metal base tube and a graphene composite layer wrapped outside the metal base tube. The graphene composite layer can conduct heat and resist acid corrosion.

[0008] Furthermore, in the graphene composite heat transfer tube, the graphene composite layer slurry is compounded on the outer wall of the metal base tube through injection and heat treatment processes in sequence.

[0009] Furthermore, in the graphene composite heat transfer tube, the graphene composite layer slurry is compounded on the outer wall of the metal base tube through casting and heat treatment processes in sequence.

[0010] Furthermore, the graphene composite heat transfer tube has grooves evenly distributed on the outer wall of the metal base tube.

[0011] Furthermore, the graphene composite heat transfer tube and the metal base tube are made of carbon steel, low alloy steel or stainless steel.

[0012] Furthermore, in the graphene composite heat transfer tube, the thickness of the graphene layer is equal to 0.3 to 3.0 mm.

[0013] Furthermore, the diameter of the metal base tube of the graphene composite heat transfer tube is φ25 to φ219 mm, and the wall thickness is 1 to 10 mm.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The graphene composite heat transfer tube disclosed in the utility model comprises a metal base tube and a graphene composite layer wrapped outside the metal base tube, and has the advantages of high mechanical strength, good heat transfer performance, strong corrosion resistance, etc., solves the defects of large heat transfer resistance caused by large wall thickness of the graphene composite tube, overcomes the disadvantages of difficult molding and high price of simple graphene tube, and has a simple production process and convenient operation. The use of the graphene composite heat transfer tube disclosed in the utility model as a heat transfer element of a low-temperature air preheater has good application prospects. When used as a heat transfer tube of an air preheater, since the air is not corrosive, the air medium flows through the composite tube, and the outer wall of the composite tube is a graphene composite material, which can resist the acid dew point corrosion of low-temperature flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the cross-sectional structure of the graphene composite heat transfer tube of the utility model;

[0017] In the above picture: 1-metal substrate tube; 2-graphene multilayer. DETAILED DESCRIPTION

[0018] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments.

[0019] Combined with Figure 1, the utility model describes in detail a graphene composite heat transfer tube, comprising a metal base tube 1 and a graphene layer 2 wrapped outside the metal base tube 1, the metal base tube 1 mainly maintains the mechanical strength of the graphene composite tube, the graphene layer 2 is heat conductive and acid corrosion resistant, the acid resistance of the graphene composite heat transfer tube is ≥99%, and the use temperature of the graphene composite heat transfer tube is less than or equal to 300°C. The graphene composite heat transfer tube disclosed in the utility model solves the defects of large heat transfer resistance caused by large wall thickness of the graphene composite tube, as well as the disadvantages of simple graphene tubes being difficult to form and expensive, and has the advantages of high mechanical strength, good heat transfer performance, strong corrosion resistance, etc.; and the production process is simple and the operation is convenient, so that it has good application prospects as a heat transfer element of a low-temperature air preheater.

[0020] As an optional design, the graphene composite heat transfer tube is preferably, the slurry of the graphene composite layer 2 is first composited on the outer wall of the metal base tube 1 by injection or casting process, and after injection or casting, the graphene composite heat transfer tube is heat treated, the first heat treatment is a curing heat treatment, the heat treatment temperature is 120-180°C, the time is 5-10 hours, the second heat treatment is a strengthening heat treatment, the temperature is 280-350°C, the time is 12-24 hours, the outer diameter of the graphene composite heat transfer tube of the utility model is generally φ25-φ219mm, the length is ≤9000mm, and the total thickness of the graphene composite heat transfer tube is 3-15mm;

[0021] It should be noted here that the slurry of the graphene multilayer includes graphene powder, carbon fiber, suspending agent, dispersing agent, binder and curing agent. The mass percentage of graphene powder is generally 5-35%, wherein the graphene powder is graphene oxide and / or graphene nano-flakes with a purity of more than 99%, and the sheet diameter of the graphene nano-flakes is 1-0 microns, the thickness is 1-10 nanometers, and the density is 0.15-0.6 g / cm 3 , carbon fiber is a reinforcing material, generally 12-24K, T300-T1000 chopped carbon fiber, the length of the carbon fiber is 0.5-1mm, the suspending agent is polyvinyl chloride or polystyrene, the dispersing agent is a polytetrafluoroethylene dispersion, the binder is an epoxy resin, furan resin, phenolic resin or fluororesin, and the curing agent is ethyl sulfate, benzenesulfonyl chloride or p-toluenesulfonyl chloride. The graphene nanosheets, suspending agent, dispersing agent and binder are uniformly mixed, and then the graphene slurry is compounded on the outer wall of the metal tube through an injection or casting process. The slurry raw materials, injection process, casting process and heat treatment process of the graphene composite layer 2 are all existing technologies, so they are not described in detail here.

[0022] As an optional design, the graphene composite heat transfer tube is preferably formed by uniformly rolling out regular grooves with concave settings on the outer wall of the metal base tube 1, wherein the grooves are circular, triangular, rhombus or other polygonal shapes, wherein the depth of the rhombus grooves is 0.2 to 1.0 mm and the side length is 3 to 50 mm.

[0023] As an optional design, the graphene composite heat transfer tube is preferably made of carbon steel, low alloy steel or stainless steel.

[0024] As an optional design, the graphene composite heat transfer pipe is preferably, the thickness of the graphene layer 2 is equal to 0.3-3.0 mm, the function of the graphene layer 2 is heat conduction and acid corrosion resistance, and the mass percentage of graphene is generally 5-35%.

[0025] As an optional design, the graphene composite heat transfer tube is preferably, the diameter of the metal base tube 1 is φ25~φ219mm, the wall thickness is 1~10mm, and the function of the metal base tube 1 is mainly to maintain the mechanical strength of the graphene composite tube.

[0026] The working process of the utility model is as follows:

[0027] The graphene composite heat transfer tube disclosed in the utility model has both the strength and toughness of a metal tube and the corrosion resistance and good heat transfer performance of graphene. When used as a heat transfer tube for an air preheater, since air is not corrosive, the air medium flows through the composite tube, and the outer wall of the composite tube is a graphene composite material, which can resist the acid dew point corrosion of low-temperature flue gas.

[0028] The graphene composite heat transfer tube disclosed in the utility model solves the defects of large heat transfer resistance caused by large wall thickness of graphite composite tube, as well as the disadvantages of difficulty in forming simple graphene tube and high price, and has the advantages of high mechanical strength, good heat transfer performance, strong corrosion resistance, etc.; and the production process is simple and the operation is convenient, so that it has good application prospects as a heat transfer element of low-temperature air preheater.

[0029] The above description is only an application implementation method of the present utility model, but the protection scope of the present utility model is not limited to this, and the right scope of the present utility model cannot be limited by this. Any equivalent changes made according to the technical solution of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A graphene composite heat transfer tube, characterized in that: It includes a metal base tube and a graphene composite layer wrapped outside the metal base tube. The graphene composite layer can conduct heat and resist acid corrosion.

2. The graphene composite heat transfer tube according to claim 1, characterized in that: The graphene composite slurry is compounded on the outer wall of the metal base tube through injection and heat treatment processes in sequence.

3. The graphene composite heat transfer tube according to claim 1, characterized in that: The graphene composite slurry is compounded on the outer wall of the metal base tube through casting and heat treatment processes in sequence.

4. The graphene composite heat transfer tube according to claim 2 or 3, characterized in that: The outer wall of the metal base tube is evenly distributed with recessed grooves.

5. The graphene composite heat transfer tube according to claim 4, characterized in that: The material of the metal base pipe is carbon steel, low alloy steel or stainless steel.

6. The graphene composite heat transfer tube according to claim 4, characterized in that: The thickness of the graphene layer is equal to 0.3 to 3.0 mm.

7. The graphene composite heat transfer tube according to claim 4, characterized in that: The diameter of the metal base tube is φ25~φ219mm, and the wall thickness is 1~10mm.

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