Heat exchange tube based on porous silicon carbide

Abstract

The utility model discloses a heat exchange tube based on porous silicon carbide, and relates to the technical field of heat exchange, the heat exchange tube comprises a cylindrical porous support body made of porous silicon carbide, the porous support body is axially provided with a heat exchange pore channel structure, and the inner wall of the heat exchange pore channel structure is uniformly sintered with a compact high-heat-conductivity heat exchange film layer. Porous silicon carbide with multiple pores in the surface is adopted as the material of the porous supporting body, the dense high-heat-conduction heat exchange film layer is sintered on the porous supporting body, and the porous silicon carbide is communicated with the outer wall of the dense high-heat-conduction heat exchange film layer through the pores in the porous silicon carbide. When cold and hot liquid and gas flow into the pores to be in contact with the outer wall of the compact high-heat-conductivity heat exchange film layer, heat exchange is achieved.

Description

Technical Field

[0001] This utility model relates to the field of heat exchange technology, specifically to a heat exchange tube based on porous silicon carbide. Background Technology

[0002] Heat exchange tubes are key components widely used in heat exchange equipment for heat transfer and separation. Existing heat exchange tubes still have some problems and limitations. For example, using alumina, a material with good thermal conductivity, to create ceramic cylinders as the heat transfer medium, and then incorporating multiple heat exchange pipes inside to achieve heat exchange through adjacent pipes, this method of heat conduction does not achieve optimal heat exchange efficiency. Additionally, some heat exchange tubes use a single-tube structure, achieving heat exchange through the tube wall. To achieve better heat exchange, these tubes often have thinner walls, which reduces the structural strength of the tube and, without external support, can lead to cracking after prolonged use. Therefore, improvements are urgently needed. Utility Model Content

[0003] The purpose of this invention is to provide a heat exchange tube based on porous silicon carbide to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0005] A heat exchange tube based on porous silicon carbide includes a cylindrical porous support body made of porous silicon carbide. The porous support body has an axially arranged heat exchange channel structure, and a dense, highly thermally conductive heat exchange film layer is uniformly disposed on the inner wall of the heat exchange channel structure. The dense, highly thermally conductive heat exchange film layer is achieved through pressureless sintering. The porous silicon carbide contains a large number of pores that communicate with the dense, highly thermally conductive heat exchange film layer. Cold liquid gas or hot liquid gas contacts the dense, highly thermally conductive heat exchange film layer through these pores, achieving heat exchange with the hot liquid gas or cold liquid gas inside the dense, highly thermally conductive heat exchange film layer. The porous support body is a ceramic structure made of porous silicon carbide and also has good thermal conductivity.

[0006] Preferably, the porous support includes cylindrical and polygonal shapes.

[0007] Preferably, the outer diameter or side length of the porous support is between 10mm and 500mm, and the length is between 100mm and 10000mm. The shape, outer diameter or side length, and length of the porous support depend on the actual application scenario.

[0008] Preferably, the cross-sectional shape of the heat exchange channel structure is circular or polygonal.

[0009] Preferably, the number of heat exchange channel structures is between 1 and 1000. Depending on the actual application, a single heat exchange channel structure may also be used.

[0010] Preferably, the dense, highly thermally conductive heat exchange film layer is made of silicon carbide, silicon nitride, aluminum, or copper. All are made of highly thermally conductive materials.

[0011] Preferably, the thickness of the dense, highly thermally conductive heat exchange film layer is between 10 μm and 1000 μm.

[0012] Due to the adoption of the above technical solution, the technological progress achieved by this utility model compared to the prior art is as follows:

[0013] 1. This utility model provides a heat exchange tube based on porous silicon carbide. Porous silicon carbide with porous surface is used as the material of porous support, and a dense high thermal conductivity heat exchange film is sintered on the porous support. The porous silicon carbide is connected to the outer wall of the dense high thermal conductivity heat exchange film through the pores inside. When hot or cold liquids or gases flow into the pores and come into contact with the outer wall of the dense high thermal conductivity heat exchange film, heat exchange is achieved.

[0014] 2. This utility model provides a heat exchange tube based on porous silicon carbide. A porous support is fixed to the outside of a dense, highly thermally conductive heat exchange film layer. This addresses the issue of weak strength caused by the long length of the dense, highly thermally conductive heat exchange film layer. Therefore, the thickness of the dense, highly thermally conductive heat exchange film layer can be between 10μm and 1000μm, reducing the thickness of the film layer and increasing heat exchange efficiency. It is made of a high thermal conductivity material and achieves good heat conduction with a relatively small thickness, making it suitable for a wide range of applications. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of multiple porous supports of this utility model;

[0016] Figure 2 This is a schematic diagram of the three-dimensional cross-sectional structure of the porous support of this utility model.

[0017] Figure 3 This is a partial structural diagram of the porous support body of this utility model, cut in half.

[0018] In the figure: 1. Porous support; 2. Heat exchange channel structure; 3. Dense, high thermal conductivity heat exchange film layer. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to embodiments:

[0020] like Figures 1-3As shown, this utility model provides a heat exchange tube based on porous silicon carbide, including a cylindrical porous support 1 made of porous silicon carbide. The porous support 1 has a ceramic structure, and multiple heat exchange channel structures 2 are axially formed on the porous support 1. A dense, highly thermally conductive heat exchange film layer 3 is sintered on each of the multiple heat exchange channel structures 2 and fixed to the inner wall of the heat exchange channel structure 2 by pressureless sintering. The porous support 1 has a large number of pores that are connected to the dense, highly thermally conductive heat exchange film layer 3. When liquid or gas is introduced into the inner wall of the dense, highly thermally conductive heat exchange film layer 3, heat is transferred to the outer wall of the porous support 1 and the liquid flowing into the pores, achieving a good heat exchange function. At the same time, the porous support 1 is located outside the dense, highly thermally conductive heat exchange film layer 3, which can ensure the strength of the dense, highly thermally conductive heat exchange film layer 3 with a certain length.

[0021] The dense high thermal conductivity heat exchange film layer 3 is prepared by pressureless sintering. The preparation process is as follows: the slurry of the dense high thermal conductivity heat exchange film layer 3 is uniformly impregnated and penetrated into the inner wall of the heat exchange channel structure 2 by slurry impregnation, and then the slurry is densified by pressureless sintering.

[0022] Furthermore, the porous support 1 made of porous silicon carbide can be cylindrical or polygonal, and the outer diameter of the porous support 1 when it is cylindrical and the side length when it is polygonal are between 10mm and 500mm, and the length is between 100mm and 10000mm. The outer diameter, side length and length are all determined by the installation scenario to ensure that they meet the usage requirements.

[0023] Furthermore, depending on the actual heat exchange requirements, the number of heat exchange channel structures 2 ranges from 1 to 1000, with a circular or polygonal cross-sectional shape. The dense, high thermal conductivity heat exchange film layer 3 is made of materials such as silicon carbide, silicon nitride, aluminum, or copper, which possess good sealing properties and high thermal conductivity. Depending on the application and heat exchange effect, a thickness between 10 μm and 1000 μm can be selected for the dense, high thermal conductivity heat exchange film layer 3. When made of silicon carbide, the dense, high thermal conductivity heat exchange film layer 3 exhibits corrosion resistance, can replace traditional metal structures, and can be widely used in chemical plants.

[0024] The relationship between heat transfer efficiency and heat exchanger tubes can be found using the heat transfer formula and Fourier's law of heat transfer below:

[0025] Heat conduction formula: Q=△T / R=△T·λ·S / L

[0026] Where: R = L / (λ·S)

[0027] Q: Heat (w), ΔT: Temperature difference (k), R: Thermal resistance (k / w), L: Thickness (m), λ: Thermal conductivity [w / (m·k)], S: Area (m²).

[0028] Fourier's law of heat conduction: q = λ·ΔT / L = Q / S

[0029] Where q=λ·△T / L=Q / S

[0030] q: heat flux density per unit area (w / m²), λ: thermal conductivity [w / (m·k)], ΔT: temperature difference (k), L: thickness (m).

[0031] Therefore, in this practical application, the thickness of the dense, highly thermally conductive heat exchange film layer 3 is relatively thin, and its thermal conductivity is relatively stronger.

[0032] like Figure 3 As shown, hot and cold liquid gases come into contact with the outer wall of the dense, highly thermally conductive heat exchange film layer 3 through numerous pores inside the porous silicon carbide, and hot and cold liquid gases flow through the interior of the dense, highly thermally conductive heat exchange film layer 3; heat conduction is achieved through the inner and outer walls of the dense, highly thermally conductive heat exchange film layer 3.

[0033] The working principle of this porous silicon carbide-based heat exchange tube will be explained in detail below.

[0034] like Figures 1-3 As shown, the heat exchange of this utility model's heat exchange tube is achieved through heat conduction, specifically through the heat conduction of a dense, highly thermally conductive heat exchange film layer 3. Taking liquid-gas heat exchange as an example, the heat exchange tube is placed in a low-temperature liquid, and high-temperature gas is transported through a pipe to the heat exchange channel structure 2 of the heat exchange tube. The low-temperature liquid permeates through the pores of the porous support 1 and directly contacts the outer wall of the dense, highly thermally conductive heat exchange film layer 3, while the high-temperature gas contacts the inner wall of the dense, highly thermally conductive heat exchange film layer 3, thus achieving heat exchange through the dense, highly thermally conductive heat exchange film layer 3. According to the heat conduction formula and Fourier's law of conduction, with constant coefficients such as temperature difference, the smaller the thickness, the higher the heat conduction efficiency. Compared with traditional heat exchange pipes, the thickness of the dense, highly thermally conductive heat exchange film layer 3 of this utility model is greatly reduced, thus greatly improving its heat exchange effect. In addition, the porous support, besides providing structural strength support, also has thermal conductivity, further enhancing the heat exchange process.

[0035] It should be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0036] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A heat exchange tube based on porous silicon carbide, characterized in that: It includes a columnar porous support made of porous silicon carbide, wherein the porous support is provided with a heat exchange channel structure in the axial direction, and the inner wall of the heat exchange channel structure is uniformly sintered with a dense, highly thermally conductive heat exchange film layer.

2. The heat exchange tube based on porous silicon carbide according to claim 1, characterized in that: The porous support includes cylindrical and polygonal shapes.

3. A heat exchange tube based on porous silicon carbide according to claim 2, characterized in that: The outer diameter or side length of the porous support is between 10mm and 500mm, and the length is between 100mm and 10000mm.

4. A heat exchange tube based on porous silicon carbide according to claim 1, characterized in that: The cross-sectional shape of the heat exchange channel structure is circular or polygonal.

5. A heat exchange tube based on porous silicon carbide according to claim 1, characterized in that: The number of heat exchange channel structures is between 1 and 1000.

6. A heat exchange tube based on porous silicon carbide according to claim 1, characterized in that: The dense, highly thermally conductive heat exchange film is made of silicon carbide, silicon nitride, aluminum, or copper.

7. A heat exchange tube based on porous silicon carbide according to claim 1, characterized in that: The thickness of the dense, highly thermally conductive heat exchange film is between 10 μm and 1000 μm.

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