The plate heat exchanger is an ideal equipment for heat exchange, and is a new type of high-efficiency heat exchanger which is assembled by stacking some metal sheets with a certain corrugated shape. The plate heat exchanger is composed of main components such as heat transfer plates, gaskets, pressing plates and clamping bolts. The surface of the plate heat exchanger is pressed into a corrugated shape or a running to increase the rigidity of the plate and increase the turbulence of the fluid. The basic classification of plate heat exchangers is generally divided into four categories according to the shape； disassembled type heat exchangers, welded plate heat exchangers and spiral plate heat exchangers. Welded plate heat exchangers are divided into semi-welded plate heat exchangers, all-welded plate heat exchangers and plate-and-shell heat exchangers.