Plate heat exchanger is a metal sheet has a corrugated shape by a series of overlapping and formed a new high efficiency heat exchanger. Thin rectangular channels formed between various plate, the plate heat exchanger. Plate heat exchanger is an ideal heat exchange equipment for liquid - liquid, liquid - vapor. It has the characteristics of high heat efficiency, low heat loss, compact structure, small occupation area, convenient installation and cleaning, wide application, long service life etc.. The condition of the same pressure loss ratio, the heat transfer coefficient of heat exchanger with high 3-5 times, covers an area of tube type heat exchanger 1/3, heat recovery rate can be as high as 90%