Magnetic control eddy current enhanced heat transfer jacketed heat exchange tube

Abstract

The application discloses a magnetic control eddy current reinforced heat transfer double-pipe heat exchange tube, which comprises a double pipe, the double pipe comprises a magnetic conducting inner pipe and an insulating outer pipe, a flow channel for high viscosity / low Pr fluid is arranged in the magnetic conducting inner pipe, a spiral electromagnetic coil is embedded between the magnetic conducting inner pipe and the insulating outer pipe, a magnetic field shielding layer is coated outside the insulating outer pipe, and the gap between the magnetic conducting inner pipe, the insulating outer pipe and the spiral electromagnetic coil is filled with heat conducting insulating material. The application provides that the surface of the magnetic conducting inner pipe is induced to generate eddy current by passing alternating current in the spiral electromagnetic coil, the Lorentz force is formed to drive the turbulent flow of the fluid in the magnetic conducting inner pipe, and the laminar flow boundary layer of the fluid is destroyed, so that the heat transfer efficiency of the high viscosity / low Pr fluid is improved. The surface heating power of the heat exchange tube can be significantly improved, the volume of the heat exchange equipment is reduced, and the size design of the equipment is more flexible. The electromagnetic driving mode without mechanical moving parts avoids the wear problem of the traditional active reinforcement technology.

Description

Technical Field

[0001] This invention relates to the field of pressure vessel and high-efficiency heat transfer technology, and in particular to a magnetically controlled eddy current enhanced heat transfer sleeve heat exchanger tube, which is suitable for extreme heat transfer scenarios of high viscosity or low Prandtl number (Pr) fluids in nuclear energy, new energy, chemical industry and other fields. Background Technology

[0002] In modern industrial systems, pressure vessel heat exchangers, as key equipment for heat exchange, are widely used in chemical, energy, aerospace, and nuclear energy fields. With the development of industrial technology towards high temperature, high pressure, and high integration, traditional pressure vessel heat exchangers have revealed numerous insurmountable technical bottlenecks when dealing with complex operating conditions, severely restricting the efficient and safe operation of related industries. From the perspective of heat transfer efficiency, traditional heat exchangers have extremely poor heat transfer performance for high-viscosity fluids (such as heavy oil and molten salts in petrochemicals) and low Prandtl number (Pr) fluids (such as liquid metals). This is because such fluids easily form stable laminar boundary layers in conventional flow channels, greatly hindering heat transfer. Existing heat transfer enhancement methods, such as adding fins or changing the flow channel structure, have very limited effects on these fluids, and may even lead to a significant increase in fluid flow resistance due to the complex structure.

[0003] From the perspective of equipment reliability and maintenance, traditional heat exchangers face serious material failure risks under extreme conditions such as high temperature, high pressure, and strong corrosion. For example, in chemical reactors, conventional metal fins are prone to corrosion, spalling, and creep deformation under high temperature and highly corrosive media, leading to a rapid decline in heat transfer efficiency and a short equipment lifespan. Furthermore, when handling fluids containing particles or prone to scaling, traditional heat exchangers are highly susceptible to fouling deposits within the flow channels. Existing chemical or mechanical cleaning methods are not only costly but may also damage the equipment, and the fouling tends to recrystallize quickly after cleaning, making long-term stable operation difficult.

[0004] With the rapid development of new energy industries (such as nuclear fusion energy development and lithium battery thermal management) and high-end manufacturing industries (such as semiconductor chip cooling), higher requirements are being placed on pressure vessel heat exchangers: efficient heat transfer needs to be achieved within a compact space. Therefore, a magnetically controlled eddy current enhanced heat transfer sleeve-type heat exchanger is needed to improve the above-mentioned key technical challenges. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention designs a magnetically controlled eddy current enhanced heat transfer sleeve-type heat exchanger. Through electromagnetic coupling flow channel design and dynamic magnetic field control, this invention overcomes the limitations of traditional heat transfer enhancement technologies, solves the problem of heat transfer being hindered by the laminar boundary layer of the fluid, thereby improving the heat transfer efficiency of high viscosity / low Pr fluids and enhancing equipment reliability under extreme operating conditions.

[0006] The present invention adopts the following technical solution: A magnetically controlled eddy current-enhanced heat transfer sleeve-type heat exchanger includes a sleeve comprising a magnetically conductive inner tube and an insulating outer tube. The magnetically conductive inner tube contains a flow channel for a high-viscosity / low Prandtl number fluid. A helical electromagnetic coil is embedded between the magnetically conductive inner tube and the insulating outer tube. The insulating outer tube is covered with a magnetic field shielding layer. The gap between the magnetically conductive inner tube, the insulating outer tube, and the helical electromagnetic coil is filled with a thermally conductive insulating material. This heat exchanger is suitable for high-viscosity, low Prandtl number media such as liquid metals and molten salts. This invention uses the alternating current of the helical electromagnetic coil to induce eddy currents in the medium inside the tube, enhancing heat transfer and creating a Lorentz force that drives turbulent flow within the magnetically conductive inner tube, disrupting the laminar boundary layer of the fluid and thus improving the heat transfer efficiency of high-viscosity / low Prandtl number fluids.

[0007] Preferably, the magnetic inner tube is made of magnetically conductive stainless steel.

[0008] Preferably, the insulating outer tube is an insulating ceramic sleeve.

[0009] Preferably, the spiral electromagnetic coil generates an axially adjustable magnetic field gradient, which can dynamically adjust the eddy current intensity according to the fluid viscosity.

[0010] Preferably, the spiral electromagnetic coil adopts a segmented power supply design, with each segment connected to the PLC controller via a lead-out rod. The current in each segment can be adjusted independently to achieve a non-uniform magnetic field distribution, adapting to the heat transfer requirements of fluids with varying properties.

[0011] Preferably, a temperature sensor is installed at the outlet end of the heat exchange tube, and the temperature sensor feeds back the medium temperature to the PLC controller.

[0012] Preferably, the inner surface of the magnetic inner tube is mirror-polished to ensure uniform eddy current distribution.

[0013] Preferably, the spiral electromagnetic coil is tightly wound around the outside of the magnetic inner tube, and the coil is made of high-temperature resistant enameled wire.

[0014] Preferably, the magnetic field shielding layer is welded to the outside of the insulating ceramic sleeve. This suppresses the leakage magnetic field interference from the electromagnetic coupling heat exchange tube to the outside environment.

[0015] Preferably, the thermally conductive insulating material is selected from one or more of magnesium oxide, aluminum oxide, and boron nitride powder.

[0016] The beneficial effects of the present invention are: (1) The heat exchange tube provided by the present invention has a spiral electromagnetic coil in the middle of the magnetic inner tube and the insulating outer tube. By passing an alternating current through the spiral electromagnetic coil, eddy currents are induced on the surface of the magnetic inner tube, forming a Lorentz force to drive the turbulent flow of the fluid in the magnetic inner tube, destroying the laminar boundary layer of the fluid, so as to improve the heat transfer efficiency of high viscosity / low Pr fluid; (2) The surface heating power of the heat exchange tube of the present invention can be significantly improved, thereby reducing the volume of the heat exchange equipment and making the equipment size design more flexible; (3) The electromagnetic drive method without mechanical moving parts avoids the wear problem of traditional active reinforcement technology. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the heat exchanger tube structure of the present invention; Figure 2 This is a schematic diagram of the heat exchanger tube arrangement system of the present invention; In the diagram: 1. Magnetic inner tube; 2. Insulating outer tube; 3. Spiral electromagnetic coil; 31. Lead-out rod; 4. Magnetic field shielding layer; 5. Temperature sensor; 6. PLC controller; 7. Thermally conductive and insulating material. Detailed Implementation

[0018] The technical solution of the present invention will be further described in detail below through specific embodiments and with reference to the accompanying drawings: Example: Figure 1 , Figure 2 A magnetically controlled eddy current enhanced heat transfer jacketed heat exchanger tube includes a jacket. The jacket is provided with a magnetically conductive inner tube 1, an insulating outer tube 2, a spiral electromagnetic coil 3, and a magnetic field shielding layer 4. The heat exchanger tube has a double-layer structure. The magnetically conductive inner tube 1 is made of magnetically conductive stainless steel and has a flow channel for high-viscosity / low Prandtl number fluid. The outer layer is an insulating ceramic jacket 2. A spiral electromagnetic coil 3 is embedded between the two layers. The gap between the magnetically conductive inner tube, the insulating outer tube, and the spiral electromagnetic coil is filled with a thermally conductive insulating material 7.

[0019] Preferably, the thermally conductive and insulating material is selected from one or more of the following: magnesium oxide, aluminum oxide, and boron nitride powder.

[0020] In this embodiment, as Figure 2 As shown, the magnetic field shielding layer 4 is welded to the outside of the insulating ceramic sleeve 2 to suppress the leakage magnetic field interference of the electromagnetic coupling heat exchange tube to the outside. The heat exchange tube induces eddy currents in the medium inside the tube through the alternating current of the spiral electromagnetic coil to enhance heat transfer. A temperature sensor 5 is installed at the outlet end of the heat exchange tube to feed back the medium temperature to the PLC controller 6. The coil current can be adjusted in real time according to the dynamic eddy current intensity based on the fluid viscosity and the outlet temperature of the heat exchange tube.

[0021] Preferably, the magnetic field shielding layer material is selected from one or more of the following: permalloy, iron-silicon-aluminum magnetic powder core, and nanocrystalline alloy.

[0022] In this embodiment, as Figure 1 , Figure 2 As shown, the spiral electromagnetic coil 3 adopts a segmented power supply design. Each segment of the spiral electromagnetic coil 3 is connected to the PLC controller 6 by the lead-out rod 31. The current of each segment can be adjusted independently to achieve a non-uniform magnetic field distribution, which is suitable for the heat transfer requirements of fluids with variable physical properties.

[0023] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A magnetically controlled eddy current enhanced heat transfer jacketed heat exchanger tube, comprising a jacket, characterized in that, The sleeve includes a magnetic inner tube and an insulating outer tube. The magnetic inner tube is provided with a flow channel for high viscosity / low Prandtl number fluid. A spiral electromagnetic coil is embedded between the magnetic inner tube and the insulating outer tube. The insulating outer tube is covered with a magnetic field shielding layer. The gap between the magnetic inner tube, the insulating outer tube and the spiral electromagnetic coil is filled with a thermally conductive insulating material. The magnetic inner tube is made of magnetic stainless steel. The insulating outer tube is an insulating ceramic sleeve that isolates the spiral electromagnetic coil from the external medium. The spiral electromagnetic coil generates an axially adjustable magnetic field gradient, which can dynamically adjust the eddy current intensity according to the fluid viscosity. The spiral electromagnetic coil adopts a segmented power supply design, with each segment of the spiral electromagnetic coil connected to the PLC controller by a lead-out rod; A temperature sensor is installed at the outlet end of the heat exchange tube, and the temperature sensor feeds back the medium temperature to the PLC controller.

2. The magnetically controlled eddy current enhanced heat transfer jacketed heat exchanger tube according to claim 1, characterized in that, The inner surface of the magnetic inner tube is mirror-polished.

3. The magnetically controlled eddy current enhanced heat transfer sleeve-type heat exchanger tube according to claim 1, characterized in that, The spiral electromagnetic coil is tightly wound around the outside of the magnetic inner tube, and the coil is made of high-temperature resistant enameled wire.

4. A magnetically controlled eddy current enhanced heat transfer jacketed heat exchanger tube according to claim 1, characterized in that, The magnetic field shielding layer is welded to the outside of the insulating ceramic sleeve.

5. A magnetically controlled eddy current enhanced heat transfer sleeve-type heat exchanger tube according to claim 1, characterized in that, The thermally conductive and insulating material is selected from one or more of magnesium oxide, aluminum oxide, and boron nitride powder.

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