Numerical simulation on flow and heat transfer of fin-and-tube heat exchanger with longitudinal vortex generators

Fin-and-tube heat exchangers with plain fins are widely used in direct air-cooled condenser system in the power plant, because of its relatively simple property compared to some other fins with variable cross-sectional area channel. In the present study, heat transfer performance and pressure drop for fin-and-tube heat exchanger with longitudinal vortex generators (LVGs) on the fin surface were numerically investigated. Rectangular and delta winglet pairs were punched/mounted on the fin surfaces to enhance the heat transfer of the air-side of the fin-and-tube heat exchangers. The results showed that the Nusselt numbers increased up to 20% for LVGs on plain fins comparing with plain fins channel without LVGs. The heat transfer enhancement by rectangular winglets was more significant than that of the delta winglets. The rectangular winglet with angle of attack of 25°showed the best overall performance than any other angles of attack in rectangular winglets configurations. Additionally, the delta winglet with angle of attack of 45° showed the best overall performance than the other angles of attack in delta winglets configurations.