The heat transfer mechanism of the plate heat exchanger is based on the law of thermodynamics: “The heat is always spontaneously transmitted from a high temperature object to a low temperature object. If there is a temperature difference between the two fluids, heat is inevitably transmitted.”In the design of the Alfa Laval heat exchangers, the plates are pressed into the channels through the rubber gasket at a certain interval, and the two fluids with temperature difference enter the plate passage through the corner holes during the forced convection heat transfer process.The two different fluids in the adjacent channels form a countercurrent or downstream flow through the plates for heat exchange. The heat exchange plates are pressed into various corrugated forms to increase the heat exchange plate area and rigidity. A reasonable form of corrugation allows the fluid to achieve high turbulence at low Reynolds numbers, creating the highest heat transfer efficiency. Since the surface of the heat transfer plate is optimized by the corrugated structure, even if the fluid flow rate is below the Reynolds value, the movement of the fluid between the plates is three-dimensional, which promotes the formation of severe turbulence of the fluid and reduces the heat transfer efficiency of the boundary layer.