From the point of view of heat transfer mechanism, plate-fin heat exchanger still belongs to Shoulder-Arm heat exchanger.Its main feature is that it has an extended secondary heat transfer surface (fin), so the heat transfer process is not only carried out on the primary heat transfer surface (bulkhead), but also on the secondary heat transfer surface.In addition to one surface pouring into the low temperature side medium, the heat of the high temperature side medium also transfers part of the heat along the height direction of the fin surface, i.e. along the height direction of the fin, heat is poured into the high temperature side medium by a baffle, and then these heat convection is transferred to the low temperature side medium.Since the height of the fin greatly exceeds the thickness of the fin, the heat conduction along the height of the fin is similar to that of a homogeneous thin guide rod.At this point, the thermal resistance of the fins cannot be neglected.The maximum temperature at both ends of the fin equals the temperature of the baffle plate. With the convection and heat release of the fin and the medium, the temperature decreases continuously until the medium temperature is in the middle of the fin.
