The U-shaped tubular heat exchanger is formed by twisting the heat exchange tubes into U-shapes, and the ends are fixed on the same tube sheet. Since the casing and the heat exchange tube are separated, the heat exchange tube bundle can be freely stretched, and no temperature difference stress is generated due to the temperature difference of the medium. U-tube heat exchanger has only one tube plate, no floating head, and the structure is relatively simple. The tube bundle can be freely extracted and loaded for convenient cleaning, and has the advantages of a floating head heat exchanger. However, since the heat exchange tubes are formed into U-bends of different radii, the outermost heat exchange tubes can be replaced after being damaged, and other tubes are replaced. Damage can only block the pipe. At the same time, compared with the fixed tube plate heat exchanger, because the heat exchange tube is limited by the bending radius, there is a gap in the central portion of the tube bundle, and the fluid is easy to short-circuit, which affects the heat transfer effect.
Characteristics
1. The bundle of U-shaped heat exchange tubes can float freely, no need to consider temperature difference stress, and can be used in large temperature difference occasions;
2. only one tube plate, the number of flanges is small, the leakage point is small, and the structure is simple;
3.The core can be cleaned;
4. Due to the limitation of the minimum bending radius of the U-shaped tube, the splitting pitch is wide, so the number of tubes is small;
5. When the flow rate in the pipe is too high, it will cause serious erosion on the U-shaped elbow section, affecting the service life.
6. Since the heat exchange tube is U-shaped, the cleaning inside the tube is difficult, so the medium inside the tube should be clean and not easy to scale.
Advantages: simple structure, only one tube plate, less sealing surface, reliable operation, low cost; tube bundle can be extracted, and cleaning between tubes is convenient.
Disadvantages: In-pipe cleaning is difficult; because the pipe needs to have a certain bending radius, the utilization rate of the tube sheet is low; the inner tube of the tube bundle is large, and the shell side is easy to be short-circuited; the inner tube is broken and can only be blocked and cannot be replaced. Therefore, the scrap rate is higher.