低风速下双风轮风力机增功现象分析

Analysis on the Phenomenon of Power Increase in Dual-wind Turbine under Low Wind Speed

将NH1500 kW风力机作为原模型,在其(主风轮)前安装同轴、同向和同转速旋转的小风轮(副风轮),得到双风轮风力机。副风轮设计成直径为26 m,叶片数依次为8~12的结构,得到五种双风轮模型,并针对以上模型在不同工况下进行气动分析。结果表明:双风轮风力机可以增大风能利用率,副风轮叶片数为10的双风轮风力机增功效果最佳;在风速为3 m/s时相较于原风力机,功率增大了14.17%,风能利用系数提高了4.53%;相较于单独运行的两风轮,其功率增大了0.47%,风能利用系数提高了1.74%;双风轮风力机的主风轮靠近叶根部分(半径小于13 m)来流风速相对减小,副风轮叶尖部分(半径约在13~20 m)来流风速相对增大;副风轮转化了部分能量,使尾流中的动能明显降低。

With NH1500 kW wind turbine as the base model,installing a small wind turbine(auxiliary wind wheel)of the same rotary axis、direction and rotating speed in front of it(main wind wheel)to obtain a dual-wind turbine.Auxiliary wind wheel with a diameter of 26 m is designed,and different number of blades as 8~12 is used to configure five types of dual-wind turbine models.The aerodynamic analysis of models under different working conditions shows that the dual-wind turbines can increase wind energy utilization.Dual-wind turbine with 10-blade auxiliary wind wheel has the best effect.When the wind speed is 3 m/s,compared with original model,the power of the double-wind turbine is increased by 14.17%,and the wind energy utilization factor is increased by 4.53%.Compared with two wind wheels running separately,the power is increased by 0.47%,and the wind energy utilization factor is increased by 1.74%.The wind speed at the area close to the blade root of the main wind wheel(radius less than 13 m)is relatively reduced,while that at the area close to the tip of auxiliary wind wheel(radius is about 13~20 m)is relatively increased.The auxiliary wind wheel converts part of energy,so the kinetic energy in the wake is significantly reduced.