Numerical investigation on the cluster effect of an array of axial flow fans for air-cooled condensers in a power plant

The aerodynamic behavior of tens of axial flow fans incorporated with air-cooled condensers in a power plant is different from that of an individual fan. Investigation of the aerodynamic characteristics of axial flow fan array benefits its design optimization and running regulation. Based on a representative 2×600 MW direct-dry cooling power plant, the flow rate of each fan and the overall flow rate of the fan array are obtained in the absence of ambient wind and at various wind speeds and directions, using CFD simulation. The cluster factor of each fan and the average cluster factor of the fan array are calculated and analyzed. Results show that the cluster factors are different from each other and that the cluster effect with ambient wind is significantly different from the cluster effect with no wind. The fan at the periphery of the array or upwind of the ambient wind generally has a small cluster factor. The average cluster factor of the array decreases with the increasing wind speeds and also varies widely with wind direction. The cluster effect of the axial flow fan array can be applied to optimize the design and operation of air-cooled condensers in a power plant.