Study On Application Of Vortex Generators On Fin-tube Heat Exchangers

Fin-tube heat exchangers are employed in a wide variety of engineering applications, for example, in an air conditioning, gas heating equipment and condenser, etc. In the typical application, almost 90 percent of thermal resistance is on the gas-side of fin-tube heat exchangers. Therefore, the research on heat transfer enhancement of gas-side in such heat exchangers has become an important project. Vortex generator, which is one mode of passive heat transfer enhancement, is more widely used in the process of engineering production. Not only because it can improve the efficiency of heat exchanger and reduce the weight as well as volume of equipments, but also it needs no extra power. The purpose of this paper is to put vortex generator into the fin-tube heat exchanger, so that it can reduce the fin-side thermal resistance and improve the heat transfer efficiency as well.One unit of heat transfer in the fin-tube heat exchanger is chosen as foundation model, which is simplified as a rectangular channel with three rows of column. As methods of heat transfer enhancement, vortex generators are settled on the foundation model. It proves that vortex generators can change the structure of flow field, reduce the poor heat transfer field and then improve the overall heat transfer efficiency.The Standard k ?εTurbulence Model is applied respectively on the numerical simulations of foundation model and the rectangular channel with vortex generators settled. The velocity field, the temperature field, the pressure field and the vorticity field are contrastively analyzed in this paper. Then the two different physical models are numerically simulated with Large Eddy Simulation. The instantaneous characteristics of flow field are analyzed and the mechanism of heat transfer enhancement of vortex generators is induced, which provide theoretical foundation for future engineering application.