Wind effect on the thermo-flow performances and its decay characteristics for air-cooled condensers in a power plant

摘要

Ambient wind plays important roles in the thermo-flow performances of air-cooled condensers, but the wind effect mainly imposes on the upwind and bilateral condenser cells and will decay immediately. It is of benefit to the design and operation optimization of air-cooled condensers in a power plant to investigate the wind effect and its decay characteristics. On the basis of a representative 2 × 600 MW direct dry cooling power plant, the physical and mathematical models of the air-side fluid and heat flows for the air-cooled condensers at various ambient wind speeds and directions are set up. The velocity and temperature fields are presented and the volumetric flow rate, inlet air temperature and heat rejection for different condenser cells are obtained by using CFD simulation. The results show that the reversed flows happened in the upwind condenser cells lead to the high inlet air temperature, worsening the cooling capability of air at high wind speeds. Due to the combined behavior of hot plume discharge and ambient wind, the wind effect decays rapidly along the wind direction. At the wind direction of 90°, the deficiencies of the thermo-flow performances of air-cooled condensers are mainly resulted from the flow rate decrease of the upwind condenser cells, not the hot plume recirculation. The hot plume recirculation flows play adverse roles in deteriorating the performances of air-cooled condensers at the wind direction of 0°.