The difference between internal flow-guiding heat exchangers and external flow-guiding heat exchangers

Thread Content

The difference between internal flow-guiding heat exchangers and external flow-guiding heat exchangers: In an internal flow-guiding tube heat exchanger, an internal flow-guiding tube is installed within the shell side tube of the heat exchanger; this allows for better utilization of those heat exchange tubes that would otherwise not be able to function effectively due to the lack of a flow-guiding element at the front or back end of the heat exchanger, thereby increasing its effective heat exchange area. Inner guide tubes are commonly used in floating-head or fixed-tube-sheet heat exchangers, but are less common in U-tube heat exchangers. The external flow-guiding heat exchanger features an additional enlarged section added to the shell of the original heat exchanger, which is used to spread the fluid flowing in the shell side. This allows the fluid to enter the shell side from both ends of the heat exchanger, thereby eliminating the need to consider the arc height of the piping layout. As a result, the number of piping elements required for a heat exchanger of the same specifications increases, and the heat exchange tubes at the front and rear ends of the heat exchanger can be utilized more effectively, increasing the effective heat exchange area. Outer flow guides are commonly used in fixed-tube-sheet heat exchangers, but are less common in U-tube heat exchangers and floating-head heat exchangers. Functionally, the inner flow guide cylinder and the outer flow guide cylinder are identical; both are intended to increase the effective heat exchange area of the heat exchanger. However, in terms of application, the latter can increase the number of tubes in a fixed-tube-sheet heat exchanger compared to the former. Heat exchangers, as heat transfer devices, can be found everywhere and are widely used in industry, especially in sectors with high energy consumption. With the rapid development of energy-saving technologies, an increasing variety of heat exchangers has been developed. Suitable for different media. Heat exchangers under different operating conditions, at different temperatures, and under different pressures also have different structures and types. The specific classifications of heat exchangers are as follows: (1) Classification by heat transfer principle: Direct contact heat exchangers ； Regenerative heat exchanger (abbreviated as regenerator) ； Plate and tube heat exchangers ； (II) Classification by type of heat transfer 1. Heat transfer without phase change is generally divided into heaters and coolers. 2. Heat transfer with phase change is generally divided into condensers and reboilers. Reboilers are further divided into kettle reboilers, siphon reboilers, reboilers, evaporators, steam evaporators, and waste heat boilers. (III) Classified by structure, they include floating-head heat exchangers, fixed-tube-sheet heat exchangers, stuffing-box heat exchangers, U-tube heat exchangers, coiled-tube heat exchangers, double-pass heat exchangers, single-sheath heat exchangers, multi-sheath heat exchangers, externally guided-tube heat exchangers, baffle-rod heat exchangers, heat-pipe heat exchangers, plug-in tube heat exchangers, and sliding-tube-sheet heat exchangers. (IV) Classification by baffle arrangement: it is divided into single-arch heat exchangers, double-arch heat exchangers, triple-arch heat exchangers, and spiral-arch heat exchangers. (5) Classified by plate type, they include spiral plate heat exchangers, plate heat exchangers, plate-fin heat exchangers, shell-and-plate heat exchangers, plate evaporators, plate condensers, printed circuit board heat exchangers, and perforated plate heat exchangers. (VI) Classification by sealing type: These types of heat exchangers are commonly used in high-temperature and high-pressure applications. They can be further divided into spiral lock ring heat exchangers, Ω-ring heat exchangers, film seal heat exchangers, steel gasket heat exchangers, and sealed cover plate heat exchangers. (7) Classification of non-metallic material heat exchangers: These include graphite heat exchangers, fluoroplastic heat exchangers, ceramic fiber composite material heat exchangers, and fiberglass-reinforced plastic heat exchangers. (8) Classification of air-cooled heat exchangers: They are divided into dry air coolers, wet air coolers, combined dry-wet air coolers, power plant air coolers, surface evaporation air coolers, plate-type air coolers, energy-recovery air coolers, natural convection air coolers, and high-pressure air coolers. (IX) Classified by material, they are mainly divided into two categories: metals and non-metals. Metals can also be divided into low-alloy steel, high-alloy steel, low-temperature steel, rare metals, etc.