在化工生产设备中,换热器占很大比例,约占设备投资的20%~40%;换热为化工最基本的单元操作,换热器完好与否对化工生产影响巨大。管壳式换热器因其结构坚固、适应性大、制造工艺成熟等优点成为主要化工换热设备。换热器由于处于受压、介质有腐蚀性、流动磨蚀,尤其是固定管板换热? In chemical production equipment, heat exchangers account for a large proportion, accounting for about 20% to 40% of equipment investment; heat exchange is the most basic chemical unit operation, the heat exchanger intact or not have a huge impact on chemical production. Shell and tube heat exchangers have become the major chemical heat exchange equipment because of their solid structure, large adaptability and mature manufacturing technology. As the heat exchanger is under pressure, the media is corrosive, fluid erosion, especially fixed tube heat exchanger?