Numerical simulation and analysis of the hot air recirculation phenomenon observed in direct air-cooled system

The hot air recirculation phenomenon observed in direct air- cooled system is numerical simulated and the causes of the hot air recirculation and its influence on air-cooled units are qualitatively analyzed with the help of computational fluid dynamics (CFD) software. The results indicate that the hot air recirculation is a common trouble in the air-cooled power units. It is provoked by the arrangement of the air-cooled island and the environmental condition around the direct air-cooled system, especially the strong wind. The hot air recirculation greatly reduces the heat transfer ability, which will worsen units' vacuum and cause the power units to trip out.