One, in accordance with the principle of classification: Direct contact heat exchanger This type of heat exchanger 's main principle is the two medium upon contact with each other to achieve heat transfer, heat transfer, contact area directly affects the heat transfer, the heat exchanger medium which is a gas, a liquid, is the main tower equipment as the main body of the heat transfer equipment, but also relates to mass transfer it is difficult to distinguish between, with the tower 's relationship, usually centralized for tower equipment, power plant cooling tower is the most typical of the direct contact heat exchanger. Energy storage type heat exchanger (the accumulator), this kind of heat exchanger with little dosage, principle of heat medium by heating the solid material to reach a certain temperature, cooling medium through the solid material is heated, so that the purpose of reaching heat transfer. Dividing wall type heat exchanger This type of heat exchanger the amount is very large, occupy the 99% above of gross, principle of heat medium through a metal or non metal heat is transferred to a cooling medium, such heat exchangers are usually referred to as the shell and tube type, plate, plate fin type or plate type heat exchanger. In two, according to the classification of heat transfer In 1, no phase change heat transfer Generally divided into the heater and cooler. In 2, a phase change heat transfer Generally divided into condenser and reboiler. Reboiler is divided into a kettle reboiler, siphon reboiler, reboiler, an evaporator, a steam generator, a waste heat boiler. In three, according to the heat transfer element classification In 1, pipe type heat transfer element: (1) of floating head type heat exchanger (2) fixed tube sheet heat exchanger (3) the stuffing box type heat exchanger (4) U type heat exchanger (5) tube type heat exchanger (6) double shell side heat exchanger (7) the single double-pipe heat exchanger (8) multiple casing heat exchanger (9) the outer tube heat exchanger (10) the rod baffle heat exchanger (11) heat pipe type heat exchanger (12) tube type heat exchanger (13) the sliding tube plate heat exchanger 2, plate type heat transfer element (1) spiral plate heat exchanger (2) heat exchanger (3) the plate-fin heat exchanger (4) plate shell type heat exchanger (5) the plate evaporator (6) the plate condenser (7) printed circuit board plate heat exchanger In four, a metal heat exchanger classification (1) graphite heat exchanger (2) fluorine plastic heat exchanger (3) the ceramic fiber composite heat exchanger (4) glass steel heat exchanger Five, air cooled heat exchanger classification (1) dry type air cooling device (2) wet air cooling device (3) dry and wet air cooling device (4) power plant air cooling device (5) surface evaporation type air cooling device (6) type air cooling device (7) the energy recovery in air cooling device (8) the natural convection air cooling device (9) high pressure air cooling device (10) a perforated plate heat exchanger In six, according to the heat transfer element classification (1) spiral tube heat exchanger (2) the corrugated pipe heat exchanger (3) shaped tube heat exchanger (4) the surface porous tube heat exchanger (5) spiral flat tube heat exchanger (6) spiral groove tube plate heat exchanger (7) the ring groove tube heat exchanger (8) the longitudinal groove tube heat exchanger (9) spiral winding pipe type heat exchanger (11) T type finned tube heat exchanger (12) the new structure of high efficient heat exchanger