Fin-type heat exchangers are devices that enhance heat transfer by increasing the heat transfer area. They are widely used in air conditioning, automotive radiators, industrial waste heat recovery, and other fields. The operating principle of these devices mainly relies on the following core mechanisms: 

Basic Structure

The fins are attached to the base tube or the surface of the plate, increasing the surface area to enhance the heat exchange efficiency.

The base tube/channel is where the high-temperature or low-temperature fluid flows inside.

The fluid channel design usually has gas on one side and liquid on the other side. The fins are used to enhance the heat exchange on the gas side. 

Operating Principle 

Modes of heat transfer

Convection heat transfer: When air flows over the surface of the fin, heat is transferred to the fin through forced convection or natural convection. The fluid inside the tube conducts heat to the tube wall through turbulence or laminar flow.

Conduction: Heat is conducted from the root of the fin to the far end of the fin, relying on the high thermal conductivity of the fin material. 

Increase the heat transfer area

The fins expand the surface area, compensating for the low heat transfer coefficient on the gas side. 

Fluid Flow Design

Cross-flow: Commonly found in air conditioning condensers, air flows laterally through the finned tube bundles, perpendicular to the direction of the fluid inside the tubes.

Counter-flow: Some highly efficient designs achieve a more counter-flow-like heat exchange through the layout of the flow channels, enhancing the logarithmic mean temperature difference. 

Typical application scenarios

Air conditioning condenser/evaporator, automotive radiator, and waste heat recovery from industrial exhaust gases