Finned tube heat exchanger is a very good energy-saving technology equipment, which can reuse the energy that would have been wasted. Finned tube heat exchanger is a member of the heat exchanger family. Today, we will introduce and analyze some of the basic working principles and important characteristics of finned tube heat exchangers, so that everyone can have a better understanding of finned tube heat exchangers.
Finned tube heat exchanger is usually composed of baffles, fins, seals and guide plates. Fins, guides and seals are placed between two adjacent partitions to form a sandwich, called a channel. The sandwich is stacked up according to different ways of fluid and brazed into a complete plate bundle. The plate bundle is the core of the finned tube heat exchanger, with necessary heads, nozzles, supports, etc., to form a finned tube heat exchanger.
In terms of heat transfer mechanism, finned tube heat exchanger still belongs to shoulder-arm heat exchanger. Its main feature is that it has an extended secondary heat exchange surface (fin), so the heat transfer process is not only carried out on the primary heat exchange surface (baffle), but also on the secondary heat exchange surface. In addition to converting a surface into a low-temperature side medium, the heat of the high-temperature side medium can also be transferred along a part of the height direction of the fin surface, that is, along the height direction of the fin, there is a baffle that converts the heat, and then the heat is transferred to the low-temperature side medium.
Since the fin height development is greatly increased beyond the fin thickness, the heat conduction analysis process along the fin height is similar to a uniform slender guide rod. At this time, the thermal resistance of the fin cannot be ignored. The temperature at both ends of the fin is greater than or equal to the temperature of the baffle. As the fin and the medium dissipate heat by convection, the temperature can continue to develop and decrease until the medium temperature is in the middle of the fin.
The fin-tube heat exchanger has high heat transfer efficiency because the disturbance of the fin to the fluid causes the boundary layer to be continuously broken and the heat transfer coefficient is large. Due to the secondary surface expansion, the specific surface area of the fin-tube heat exchanger can reach 1000㎡/m3. Due to the compact structure, it is mostly made of aluminum alloy, and now steel, copper, and composite materials have also been mass-produced. Adaptive fin-tube heat exchangers can be used for heat exchange and phase change between gas-gas, gas-liquid, liquid-liquid and various fluids. Through the layout and combination of flow channels, it can adapt to different heat exchange conditions such as counterflow, crossflow, multi-flow, and multi-flow. By improving the combination of series, parallel, and series-parallel connection of units, the heat exchange needs of large-scale enterprise equipment in my country can be met. Industrial molding and batch production can be carried out to reduce costs, and interchangeability can be expanded through block combination.
The manufacturing technology process is strict and complex. It is easy to clog, corrosion-resistant, and very difficult to clean and maintain. Therefore, it can only be used in occasions where the heat exchange medium is clean, non-corrosive, non-scaling, and not easy to clog.
