Heat exchanger is a kind of equipment that transfers part of the heat of hot fluid to cold fluid, also known as heat exchanger. Heat exchanger plays an important role in chemical, petroleum, power, food and many other industrial production. It can be widely used as heater, cooler, condenser, evaporator and reboiler in chemical production. 2、 The classification is applicable to the heat exchangers with different media, different working conditions, different temperatures and different pressures, and the structural types are also different. The specific classification of heat exchangers is as follows: 1. According to the heat transfer principle, the inter wall heat exchanger is a kind of inter wall heat exchanger in which two kinds of fluids with different temperatures flow in the space separated by the wall, and the heat conduction and fluid convection on the wall surface, Heat transfer between the two fluids. There are shell and tube type, sleeve type and other types of inter wall heat exchanger. The inter wall heat exchanger is the most widely used heat exchanger at present. The regenerative heat exchanger transfers heat from the high temperature fluid to the low temperature fluid through the heat storage body composed of solid materials. The heat medium first reaches a certain temperature by heating the solid materials, and then the cold medium is heated through the solid materials, so as to achieve the purpose of heat transfer. Regenerative heat exchanger has rotary type, valve switching type and so on. Fluid connected indirect heat exchanger fluid connected indirect heat exchanger is a heat exchanger that connects two surface heat exchangers by circulating heat carriers. The heat carrier circulates between the high temperature fluid heat exchanger and the low temperature fluid, receives heat in the high temperature fluid, and releases heat to the low temperature fluid in the low temperature fluid heat exchanger. Direct contact heat exchanger is also known as hybrid heat exchanger. This kind of heat exchanger is a kind of equipment that two kinds of fluids contact directly and mix with each other for heat exchange, such as cold water tower, gas condenser, etc. The compound heat exchanger has two kinds of heat exchange modes: steam surface indirect heat exchange and water water direct mixed flow heat exchange. Compared with steam surface indirect heat transfer, it has higher heat transfer efficiency; Compared with steam water direct mixing heat transfer, it has higher stability and lower unit noise. 2. According to the purpose of classification, the heater is to heat the fluid to the necessary temperature, but there is no phase change in the heating fluid. The preheater pre heats the fluid to provide standard process parameters for process operation. Superheater superheater is used to heat the fluid (process gas or steam) to superheated state. The evaporator is used to heat the fluid to reach the temperature above the boiling point and make the fluid evaporate, generally with phase change. 3. According to the structure classification, it can be divided into floating head heat exchanger, fixed tube sheet heat exchanger, U-tube sheet heat exchanger, plate heat exchanger, etc. 3 All kinds of working principle pictures picture of tube heat exchanger picture of coking plant regenerator picture of floating head heat exchanger picture of immersed snake tube heat exchanger picture of plate heat exchanger picture of heat exchanger with compensation ring picture of plate fin heat exchanger picture of jacket heat exchanger picture of U-tube heat exchanger picture of tube heat exchanger parts picture of spiral plate heat exchanger picture of tube heat exchanger picture Film spray heat exchanger gas cooling tower