Study on wake effect of series fans

Abstract

Within the range of finite land resources, in order to improve the power generation efficiency of wind farms and reduce the impact of wake effects on the output power of fans, the rationality of wind farm fan layout is very important. The wake velocity and output power of two 2.5MW experimental fans in series 5D spacing are obtained by means of Doppler measured anemometer of windcube2. Based on CFX numerical simulation method, the simulation of the wake field is carried out by ANSYS software. The results showed that the fan spacing of 5D, the simulation and experimental results were basically the same. As the axial distance increased, the axial velocity first decreased and then increased, gradually recovered the incoming wind speed. The radial velocity and the tangential velocity amplitude and frequency fluctuation of different sections at the same angle were gradually reduced. The amplitude and frequency fluctuation of the tangential velocity were the largest at 3D, and were the minimum at 8D. The amplitude and frequency fluctuation of the radial velocity were the largest at 5D, and were the minimum at 3D. The velocity at the center of the bub gradually increased, and the velocity variation was the most obvious at 3D. The simulation speed first appeared an upward trend. Due to the superposition of the upstream fan wake, the output power of the downstream fan was greatly affected. Therefore, in the actual planning of the wind farm, the downstream fan should not be completely arranged in the wake field of the upstream fan.