Research on improving the heat transfer of stainless steel tube heat exchangers includes research on enhancing heat transfer on both sides of the tube side and shell side. By strengthening the structural elements and optimizing implementation of the tube and shell process, the editor below has compiled a few points for your reference.
1, Enhanced heat transfer tube elements: The shape of the heat transfer surface and the surface or inserted heat flow path are set in different shapes. There are a variety of heat transfer surfaces that change shape and are used to enhance heat transfer tubes.:Spiral grooved tubes, transversal tubes, threaded tubes, scaled, vortex tubes and spiral flat tubes, etc. Alternatively, you can use interfering elements, twisted iron tubes, coil wires or metal fragments and add content that can also enhance turbulence and disrupt laminar layers.
2, Spiral grooved tube: The spiral grooved tube wall is extruded by the light tube. The nearby main spiral groove tube strengthens the restriction of heat transfer wall flow, causing the fluid movement throughout the spiral tube to generate local secondary flow. The spiral groove is resisted by the body, generating a reverse pressure gradient and boundary layer separation. Spiral grooved tubes and double sides enhance heat transfer, suitable for convection working conditions, boiling and condensation.
3, Scaling tube: The heat exchange tube on the surface of the bamboo structure, the flow in the tube causes shrinkage and amplification effects, increases turbulence to a moderate degree, and improves the ability of the heat exchange tube. The medium near the tube wall flows along the tube and tube axis, and the direction and speed of the node suddenly change, forming local turbulence, diluting liquid retention, reducing the thermal resistance of the wall, and also making the heat transfer capacity of the outside of the tube a medium.
4. Low thread fin tube: Ordinary heat exchange tubes form a type of outer surface of heat exchange tubes by rolling threaded fins. Strengthen the outside of the tube. On the one hand, strengthening the media is reflected in the increased heat exchange area of ​​the threaded fins; on the other hand, because the shell-side medium flows through the surface of the threaded tube, the laminar boundary layer on the surface of the threaded fins is divided, and the thickness of the boundary layer becomes thinner.
5. Diamond-shaped fin tubes: Diamond-shaped fin tubes have continuous three-dimensional fins for one week, high efficiency in heat transfer, and their heat transfer enhancement performance is better than that of fin tubes with continuous fins that last for several weeks. When used for condensation to enhance heat transfer, the surface tension of the liquid film on the fin surface of the three-dimensional fin is unevenly distributed due to its special structure.(Roots are big and small), the liquid film is pulled, which significantly thins the liquid film thickness on the surface of the three-dimensional fins, reduces the thermal resistance, and enhances the heat transfer capacity of the pipe steam medium and the external wall to improve the impact of heat transfer.
6, Corrugated tube: Corrugated tube is a common smooth tube heat exchange tube. There is no cutting roller penetration process to plastically deform the metal on the inner and outer surfaces of the tube, and the tube type has corrugations on both sides.
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