The main factor affecting the heat-exchanging performance of direct air cooling condenser is backflow or recirculation of the hot air resulted from the ambient strong wind. A mathematical model of flow and heat transfer in direct air cooling condenser for a 135 MW unit has been established. By using a heat transfer software Fluent

the numerical simulation of direct air cooling condenser's performance under condition under turbine rated load (TRL) in summer has been carried out

i.e. the velocity field and temperature field of air outside the air cooling condenser have been simulated

analyzed

and studied

providing with help of optimizing design of the direct air cooling system.