Graphene air preheater

Abstract

The utility model belongs to the technical field of petrochemical industry and coal chemical industry energy-saving equipment, and particularly discloses a graphene air preheater which is characterized in that a flue gas inlet section and a flue gas outlet section are oppositely arranged at the upper end and the lower end of a preheater box body and are respectively communicated with a cavity of the preheater box body to form a flue gas channel; a plurality of graphene composite heat transfer pipes perpendicular to the flue gas channel are arranged in the cavity of the preheater box body in a penetrating mode, and the two ends of each graphene composite heat transfer pipe communicate with an air inlet section and an air outlet section which are arranged on the left side and the right side of the preheater box body correspondingly to jointly form an air channel. The graphene air preheater is used for deeply recovering heat of low-temperature flue gas of the heating furnace, so that the heat efficiency of the heating furnace can be greatly improved, energy is saved, good economic benefits are brought to enterprises, pollution gas emission can be reduced, good social benefits are brought, and the graphene air preheater has good application prospects.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy-saving equipment in petrochemical and coal chemical industries, and specifically discloses a graphene air preheater. Background Art

[0002] At present, waste heat recovery systems used in petrochemical and coal chemical industries to recover low-temperature heat below the flue gas dew point generally use corrosion-resistant non-metallic air preheaters. Corrosion-resistant non-metallic materials mainly include enamel coatings, graphite, glass, etc. Enamel coatings have a certain ability to resist acid dew point corrosion, but the application effect is not satisfactory. The main reasons for the failure of enamel coatings are: First, the defects of the enameled coating, such as bubbles and pinholes, when the acid-containing liquid passes through the pinholes of the enamel coating, it will corrode the base material along the pinholes, causing the heat exchange tubes to be perforated and fail. There are two main structural types of glass air preheaters: glass tube and glass plate. Glass tube air preheaters are more commonly used. The advantage is that glass materials can be produced in a standardized manner and are low in cost. The disadvantages of glass tube air preheaters are: (1) Glass is a brittle material with low strength and is prone to breakage under alternating stress; (2) The thermal conductivity of glass is very low, only 1.25W / m·k, resulting in poor heat transfer performance of glass tube air preheaters; (3) Sealing is difficult, and because glass tubes and metal tube plates are dissimilar materials and cannot be welded, only packing can be used for sealing. The reliability of packing sealing is low, and air leakage is prone to occur in air preheaters. The above disadvantages limit the application of glass air preheaters. Graphite air preheaters have good corrosion resistance and heat transfer performance, but graphite materials are relatively brittle and have low mechanical strength, which limits the promotion and application of graphite air preheaters. Summary of the invention

[0003] In order to solve the problems in the background technology, the utility model discloses a graphene air preheater, including a double-layer graphene composite heat transfer tube, which has excellent corrosion resistance and heat transfer performance, and high strength, and can ensure the reliable operation of the air preheater.

[0004] In order to achieve the above-mentioned invention object, the utility model adopts the following technical solutions:

[0005] A graphene air preheater comprises a preheater box with a hollow sealed structure, wherein a smoke inlet section and a smoke outlet section are arranged oppositely at the upper and lower ends of the preheater box, the smoke inlet section and the smoke outlet section are respectively connected with the cavity of the preheater box to form a smoke channel, a plurality of graphene composite heat transfer pipes arranged perpendicular to the smoke channel are penetrated in the cavity of the preheater box, sealing components are respectively sleeved on both ends of the graphene composite heat transfer pipe, the two ends of the graphene composite heat transfer pipe are respectively connected with the air inlet section and the air outlet section arranged on the left and right sides of the preheater box to form an air channel, and the graphene composite heat transfer pipe comprises an inner metal base pipe and an outer graphene composite material.

[0006] Furthermore, the graphene air preheater, the metal base tube and the graphene composite material are compounded by casting or injection.

[0007] Furthermore, the sealing assembly of the graphene air preheater includes a metal tube sheet and a sealing tube sheet, the metal tube sheet is made of carbon steel, alloy steel or stainless steel, and the sealing tube sheet is made of silicone rubber, fluororubber or polytetrafluoroethylene.

[0008] Furthermore, the graphene air preheater, the metal tube sheet and the sealing tube sheet are connected by threads or bonded with an adhesive.

[0009] Furthermore, the graphene air preheater has correspondingly arranged tube holes for the graphene composite heat transfer tube to pass through on the metal tube sheet and the sealed tube sheet, and the graphene composite heat transfer tube is interference fit with the tube holes of the sealed tube sheet.

[0010] Furthermore, the graphene air preheater has a polytetrafluoroethylene coating sprayed on the inside of the flue gas outlet section or a heat-lined polytetrafluoroethylene sheet.

[0011] Furthermore, in the graphene air preheater, a support ring for protecting the graphene composite heat transfer tube is provided between the tube holes of the metal tube sheet and the graphene composite heat transfer tube.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] The graphene air preheater disclosed in the utility model adopts a high-performance graphene composite heat transfer tube as a heat exchange element, which has both corrosion resistance and good heat transfer performance, and also has the high mechanical strength of a metal tube. At the same time, the graphene composite heat transfer tube and the sealing tube plate of the sealing assembly adopt an elastic interference fit, which is not only simple to assemble but also reliable in sealing. The graphene air preheater of the utility model is used to deeply recover the heat of the low-temperature flue gas of the heating furnace, which can not only greatly improve the thermal efficiency of the heating furnace, save energy, and bring good economic benefits to the enterprise, but also reduce the emission of polluting gases, bring good social benefits, and have good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the three-dimensional structure of the graphene air preheater of the utility model;

[0015] Figure 2 It is a cross-sectional structural schematic diagram of the sealing component in the utility model;

[0016] Figure 3 This is a schematic diagram of the connection structure between the sealing component and the graphene composite heat transfer pipe in the utility model;

[0017] In the above figure: 1-air inlet section; 2-flue gas inlet section; 3-graphene composite heat transfer tube; 4-preheater box; 5-air outlet section; 6-flue gas outlet section; 7-sealing assembly; 7.1-metal tube sheet; 7.2-sealing tube sheet; 7.3-first tube hole; 7.4-second tube hole; 7.5-support ring. 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] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. In addition, a brief description is given of the orientation involved in this specific implementation: the directions or positional relationships indicated by "front", "rear", "up", "down", "left", "right", etc., of each structural member mentioned below refer to the orientation or positional relationship shown in the accompanying drawings; these positional relationships are only for the convenience of description and simplified description, and do not indicate or imply that the device referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. If there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used to distinguish the purpose of description, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated.

[0020] Combined with Figure 1-3The utility model is a graphene air preheater, comprising a preheater box 4 with a hollow sealed structure, wherein a smoke inlet section 2 and a smoke outlet section 6 are arranged at the upper and lower ends of the preheater box 4, respectively, and the smoke inlet section 2 and the smoke outlet section 6 are connected with the cavity of the preheater box 4 to form a smoke channel, and a plurality of graphene composite heat transfer pipes 3 arranged perpendicular to the smoke channel are penetrated in the cavity of the preheater box 4, and sealing components 7 are respectively sleeved at both ends of the graphene composite heat transfer pipe 3, and the two ends of the graphene composite heat transfer pipe 3 are respectively connected with the air inlet section 1 and the air outlet section 5 arranged on the left and right sides of the preheater box 4 to form an air channel, and the graphene composite heat transfer pipe 3 comprises an inner metal base pipe and an outer graphene composite material, and the graphene composite heat transfer pipe 3 has both the strength and toughness of the metal pipe and the corrosion resistance and good heat transfer performance of graphene. When used as a heat transfer pipe of an air preheater, since the air has no The air medium flows through the graphene composite heat transfer tube 3. The outer wall of the graphene composite heat transfer tube 3 is a graphene composite material, which can resist the acid dew point corrosion of low-temperature flue gas. As a heat transfer element, the graphene composite heat transfer tube 3 can resist the dew point corrosion of flue gas and has good heat transfer performance. It can operate reliably in flue gas below 280°C. The sealing component 7 and the graphene composite heat transfer tube 3 can maintain a strict seal to ensure that the air preheater does not have cross-flow and leakage. When working, the high-temperature flue gas enters the preheater box 4 through the flue gas inlet section 2 and flows through the outside of the graphene composite heat transfer tube 3. After heat exchange with the air in the graphene composite heat transfer tube 3, it becomes cold flue gas and is discharged from the preheater box 4 through the flue gas outlet section 6. The cold air passes through the air inlet section 1, passes through the sealing component 7, and enters the graphene composite heat transfer tube 3. After heat exchange with the flue gas outside the graphene composite heat transfer tube 3, it becomes high-temperature air. After being discharged through the air outlet section 5, it enters the next-level air preheater or the hot air system of the heating furnace.

[0021] As an optional design, the graphene air preheater is preferably composed of a metal base tube and a graphene composite material by casting or injection. The graphene composite heat transfer tube 3 has both the strength and toughness of a metal tube and the corrosion resistance and good heat transfer performance of graphene.

[0022] As an optional design, the graphene air preheater is preferably used, and the sealing component 7 is a composite tube sheet, including a metal tube sheet 7.1 and a sealing tube sheet 7.2. The material of the metal tube sheet 7.1 is carbon steel, alloy steel or stainless steel, and the general thickness is 10 to 40 mm. The material of the sealing tube sheet 7.2 is silicone rubber, fluororubber or polytetrafluoroethylene material, and the general thickness is 20 to 50 mm. It has good elasticity and resistance to flue gas acid dew point corrosion. The sealing tube sheet 7.2 not only seals with the graphene composite heat transfer tube 3, but also protects the metal tube sheet 7.1 from flue gas corrosion. The sealing component 7 and the graphene composite heat transfer tube 3 can maintain a strict seal to ensure that the air preheater does not have cross-flow or leakage.

[0023] As an optional design, the graphene air preheater is preferably used, wherein the metal tube sheet 7.1 and the sealing tube sheet 7.2 are connected by threads or bonded with an adhesive, and the sealing tube sheet 7.2 protects the metal tube sheet 7.1 from being corroded by flue gas.

[0024] As an optional design, the graphene air preheater is preferably provided with tube holes for the graphene composite heat transfer tube 3 to pass through on the metal tube sheet 7.1 and the sealed tube sheet 7.2, and the tube holes include a first tube hole 7.3 provided on the metal tube sheet 7.1 and a second tube hole 7.4 provided on the sealed tube sheet 7.2. The first tube hole 7.3 and the second tube hole 7.4 are coaxially arranged. The inner diameter of the first tube hole 7.3 is larger than the outer diameter of the graphene composite heat transfer tube 3, and the outer diameter of the graphene composite heat transfer tube 3 is slightly larger than the inner diameter of the second tube hole 7.4. The graphene composite heat transfer tube 3 and the sealed tube sheet 7.2 are connected to each other. The holes of the sealing tube sheet 7.2 are interference fit. After the graphene composite tube 3 passes through the sealing tube sheet 7.2, the tube holes of the sealing tube sheet 7.2 are elastically deformed so that they can be tightly wrapped and pressed on the outer surface of the graphene composite heat transfer tube 3. The purpose of sealing the sealing tube sheet 7.2 and the graphene composite heat transfer tube 3 is achieved through interference fit. A support ring 7.5 for protecting the graphene composite heat transfer tube 3 is provided between the first tube hole 7.3 on the metal tube sheet 7.1 and the graphene composite heat transfer tube 3. The support ring 7.5 is sleeved on the graphene composite heat transfer tube 3 to prevent the outer wall of the graphene composite tube 3 from contacting and colliding with the metal tube sheet 7.1.

[0025] As an optional design, the graphene air preheater is preferably sprayed with a polytetrafluoroethylene coating or a heat-lined polytetrafluoroethylene sheet inside the flue gas outlet section 6 as an anti-corrosion layer. The thickness of the anti-corrosion layer is generally 1 to 3 mm to resist the acid dew point corrosion of the low-temperature flue gas.

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

[0027] Since the graphene composite heat transfer tube 3 includes an inner metal base tube and an outer graphene composite material, the graphene composite heat transfer tube 3 has both the strength and toughness of a metal tube and the corrosion resistance and good heat transfer performance of graphene. When used as an air preheater heat transfer tube, since air is not corrosive, the air medium flows through the graphene composite heat transfer tube 3. The outer wall of the graphene composite heat transfer tube 3 is a graphene composite material, which can resist acid dew point corrosion of low-temperature flue gas. As a heat transfer element, the graphene composite heat transfer tube 3 can resist dew point corrosion of flue gas and has good heat transfer performance. The sealing component 7 and the graphene composite heat transfer tube 3 are The heat transfer tube 3 can maintain a strict seal to ensure that the air preheater does not have cross-flow or leakage. When working, the high-temperature flue gas enters the preheater box 4 through the flue gas inlet section 2, flows through the outside of the graphene composite heat transfer tube 3, and becomes cold flue gas after heat exchange with the air in the graphene composite heat transfer tube 3. It is discharged from the preheater box 4 through the flue gas outlet section 6. The cold air passes through the air inlet section 1, passes through the sealing component 7, and enters the graphene composite heat transfer tube 3. It becomes high-temperature air after heat exchange with the flue gas outside the graphene composite heat transfer tube 3. It is discharged through the air outlet section 5 and enters the next-level air preheater or the hot air system of the heating furnace.

[0028] 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 air preheater, characterized in that: A preheater box body with a hollow sealing structure is provided, wherein a smoke inlet section and a smoke outlet section are arranged oppositely at the upper and lower ends of the preheater box body, the smoke inlet section and the smoke outlet section are respectively connected with the cavity of the preheater box body to form a smoke channel, a plurality of graphene composite heat transfer pipes arranged perpendicular to the smoke channel are passed through the cavity of the preheater box body, sealing components are respectively sleeved on both ends of the graphene composite heat transfer pipe, the two ends of the graphene composite heat transfer pipe are respectively connected with the air inlet section and the air outlet section arranged on the left and right sides of the preheater box body to form an air channel, and the graphene composite heat transfer pipe comprises an inner metal base pipe and an outer graphene composite material.

2. The graphene air preheater according to claim 1, characterized in that: The metal base tube and the graphene composite material are compounded by casting or injection.

3. The graphene air preheater according to claim 1 or 2, characterized in that: The sealing assembly comprises a metal tube sheet and a sealing tube sheet. The material of the metal tube sheet is carbon steel, alloy steel or stainless steel, and the material of the sealing tube sheet is silicone rubber, fluororubber or polytetrafluoroethylene.

4. The graphene air preheater according to claim 3 is characterized in that: The metal tube sheet and the sealing tube sheet are connected by threads or bonded with an adhesive.

5. The graphene air preheater according to claim 3, characterized in that: Tube holes for the graphene composite heat transfer tube to pass through are correspondingly arranged on the metal tube sheet and the sealed tube sheet, and the graphene composite heat transfer tube is interference fit with the tube hole of the sealed tube sheet.

6. The graphene air preheater according to claim 3, characterized in that: Spray PTFE coating or heat-line PTFE sheet inside the flue gas outlet section.

7. The graphene air preheater according to claim 5, characterized in that: A support ring for protecting the graphene composite heat transfer tube is arranged between the tube hole of the metal tube sheet and the graphene composite heat transfer tube.

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