What are Heat Exchangers? These are special devices use to transfer heat between two fluids without having to bring the fluids themselves into contact with each other. Heat ex-changers can effectively transfer heat between two liquids, a liquid and a gas or between two gases. Heat exchangers which work on the same principle but transfers heat with the interaction of air are called as Air Cooled Heat Exchangers.
Importance & Applications of Heat Exchangers: These are vital components of machinery and factories while common examples of heat exchangers include car radiators and in refrigerators and air conditioners. Air cooled heat exchangers are those types of heat exchangers where heat is transferred from a hot fluid to the air which is flowing around it.
Air Cooled heat exchangers are mostly used in processes which generate heat which has no local use and must be removed. A car radiator is a good example of an air cooled heat exchanger. Water or coolant collects heat from the engine and flows through the radiator tubes and air flows over these tubes to collect this heat through the process of convection.
Design of Air Cooled Heat Exchangers: A number of closely spaced, thin plates or fins are attached to the tubes to increase the surface area and improve the rate of heat transfer between the two fluids. Air cooled heat exchangers fall under the category of cross flow heat exchangers since the two fluids move in a direction perpendicular to each other. The same principle is used in large air cooled heat exchangers in industries.