Numerical study on the impact mechanism of windshield devices on frozen phenomena in a direct air-cooled system

Abstract

Research on effects of windshield devices on frozen phenomena in a direct air-cooled condenser (DACC) is of great significance to avoid the risk of freezing in an extremely cold region or country. This study focused on analyzing frozen phenomena in DACCs in a representative 2 × 350 MW power plant by the numerical method of Fluent software. Results showed that frozen phenomena were more likely to appear in the last row under conditions of windshield devices length (L) below 20 m, wherein both the maximum airflow rate and the minimum inlet air temperature occurred. With an increase of L, the frozen region gradually decreased and disappeared, and the frozen phenomena did not occur in DACCs when L reached the maximum length. Airflow entered the DACC along the direction of the down-flow, and the inclined angle α increased along the wind direction at L = 0 m. For a long windshield device, the value of the wind velocity became much smaller, and the airflow entered the DACC from two opposite directions.