Plate heat exchanger is a type of heat exchanger that is formed by pressing thin metal plates into heat exchange plates with a certain ripple shape, then stacking them and fastening them with clamps and bolts. Thin rectangular channels are formed between various plates for heat exchange through half plates. The working fluid flows through a narrow and tortuous channel formed between two plates. Cold and hot fluids pass through the flow channel in sequence, with a partition plate in the middle separating the fluid and conducting heat exchange through this plate. The structure and heat transfer principle of plate heat exchangers determine their compact structure, small footprint, high heat transfer efficiency, high operational flexibility, wide application range, low heat loss, and convenient installation and cleaning.