Heat transfer enhancement using different types of turbulators on the heat exchangers

Abstract

Energy-saving and heat transfer enhancement considerations are more crucial due to nearly running out energy resources and ensuring the sustainability of nature. The heat exchangers are one of the main components and directly affect the thermal efficiency of the systems. To enhance the heat transfer rate, the fin and plate structure is widely used. Various vortex generators may be involved generally on the surface of fins, like ribs, baffles, delta winglets, and perforations. Turbulators make the heat transfer performance better significantly but increase the friction of the fluid on the contacting surfaces and cause the pressure drop-down which depends on thermal properties of the fluid characteristics. This paper presents general protrusion vortex generators overview to heat transfer augmentation with pressure loss as an extensive literature review. The correlations are derived in terms of some parameters of turbulators like; angle, pitch, shape and combinations of an array. The target of this study is consolidating the verified outputs of the literature and support the increasing thermal performance of the heat exchangers. In conclusion, two tables are made for the first time and summarizing the crucial features of solid, perforated baffles/blockages and winglet turbulators, mentioned in the literature are presented. Obstacles such as winglets and vortex generators are used commonly to increase the heat transfer rate per unit volume for finned to tube exchangers with various types. In order to augment the heat transfer, the design parameters of important consideration are attack of angles, height and array structure in both laminar and turbulated fluid characteristics. Involving perforation forms on the surface may be used for winglets with variable angles both decrease the pressure loss and increase the heat transfer performance.