Numerical Simulation of Flow and Heat Transfer of a Direct Air-Cooled Condenser Cell in a Power Plant

The classical A-frame condenser cell and the complicated flow field at the exit of the axial flow fan bring on the air mal-distribution on the finned tube bundles and poor efficiencies. This paper addresses the detailed characteristics of the thermo-flow in the A-shaped frame condenser cell and the influence of the ambient temperature on the performance of the condenser cell. A three dimensional coupled air flow field calculation is carried out for the rotational fan and the stock-still A-shaped frame-work with the computational fluid dynamics code ANSYS FLUENT12.0. Results show that the coupled computation not only could give boundary conditions conveniently, but also could reflect many important flow phenomena, such as flow backward, biased flow and the air flow field in the chamber is rather complex. The distribution of velocity and temperature in A-frame at different cross sections are presented. Furthermore, the inlet air velocity of the finned tube bundles under different ambient temperature are compared. These simulations provide basis for both understanding the existing deficiencies of the A-frame condenser cell and moreover provide direction for improved designs in the future.