Review of Heat Transfer Augmentation in a Tube Heat Exchanger Using Passive Methods: Enhancing Heat Exchanger Efficiency with Passive Methods

Abstract

There is a need to increase efficiency of existing heat exchangers by increasing the heat transfer area. It is possible with introducing passive methods of heat transfer. Heat transfer augmentation methods are employed in existing heat exchangers to increase heat transfer rate and decrease the size, weight there by cost of the system. It is proved that on adapting these methods, the overall thermal performance increases substantially. This paper reviews the work done on the use of passive techniques like swirl flow devices, surface roughness, coiled tubes, etc. in heat exchangers. It is found that a number of researches used different types of turbulators and these helped to continuously enhance the heat exchanger efficiency. In laminar regime, the twisted tape gives good results than in turbulent regime.