Performance prediction of an air-cooled steam condenser using UDF method

Abstract

The performance of air-cooled steam condensers (ACSCs) is always influenced under the unfavorable effect of wind conditions. It is significant to understand the mechanism of such influences so as to improve and optimize the performance of the condensers. In this study, the flow field around a 2 × 600 MW direct air-cooled power plant at different wind speeds and ambient temperatures is numerically simulated, and the relevant influence mechanism is illustrated. User defined function (UDF) based on steam properties, which plays a critical role in the prediction of condenser back pressures, is proposed to simulate the condensation of the turbine exhaust in the exchangers. It is found that wind speed has great influences on the performance of air-cooled steam condensers due to the variation of pressure distribution around the ACSC platform. Heat transfer rate degrades rapidly, while the fan flow rate rises slightly, with the increase of ambient temperature because the heat transfer potential between ambient air and the turbine exhaust is determined by their temperature difference. Finally, the stable back pressures corresponding to each prescribed wind condition are forecasted according to the comparison between the computational heat transfer rate and the ideal heat rejection.