Numerical Investigation of Recirculation of Air-Cooled Condensers for a Large Power Plant

Abstract

In order to minimize the recirculation to ensure normal operation of the air-cooled condensers (ACC) system, the recirculation phenomenon and its dependence on ambient winds are numerically simulated by using the computational fluid dynamics code, FLUENT. Under the constant ambient temperature, the effects of different wind speed and wind direction on the recirculation are qualitatively considered by applying the concept of the recirculation rate. The mechanism of occurrence of recirculation are presented and analyzed. It was found that when considering about the existing and normally operating power plants, the recirculation is more sensitive to wind direction and wind speed. Based on the above results, three improved measures increasing the wind-wall height and accelerating the rotational speed of the fans near the edge of the ACC platform and lengthen or widen the platform are developed to effectively reduce the recirculation.