垂直轴风力机群组错列布机气动特性研究

Numerical Study on Aerodynamic Characteristics of Vertical Axis Wind Turbine Cluster with Equilateral Triangle Arrangement

垂直轴风力机因其运行稳定、低速尾迹恢复快及成本低廉等优势,更适宜大型化与群组化发展。为研究垂直轴风力机群组的气动特性和优化策略,通过数值模拟方法定量分析不同来流风向和不同布机间距下由8个同旋垂直轴风力机所组成群组的气动特性,并建议错列布机群组的最佳布机间距。结果表明:群组中风力机最佳尖速比降低、运行稳定性提高;布机间距和来流风向均影响功率密度和群组效率,且布机间距减小,群组互耦效应增强,功率密度大幅提高,尖速比为2.62,不同来流风向下,布机间距k从5减小到2时,群组最大功率密度增幅均可达3倍。适当的布机方式可避免下游风力机处于上游风力机的低速尾迹中,布机间距与布机方式的合理搭配可提升风力机群组平均风能利用系数和功率密度,最终使土地资源得以合理利用。

Vertical axis wind turbine is more suitable for large scale and group development due to its advantages of stable operation,fast recovery of low-speed wake and low cost.In order to study the aerodynamic characteristics and optimization strategy of the vertical axis wind turbine group,the numerical simulation method was used to analyze the aerodynamic characteristics of the group composed of 8 vertical axis wind turbines under different flow and wind directions and different spacing in between machines,and the optimal spacing of machines was suggested.The results show that the optimum tip ratio of wind turbines in the group is decreased and the operation stability is improved.Both machine spacing and wind flow influence the power density and group efficiency.As machine spacing decreases,the mutual coupling effect in the groups is enhanced,and the power density is significantly improved.With the peak speed ratio of 2.62,the maximum power density of the group can be increased by 3 times when the k value is decreased from 5 to 2.An appropriate arrangement of machines can avoid the downstream wind turbine from being located in the low speed wake generated from the upstream turbine.Proper configuration of machine spacing and positioning can promote wind farm wind energy utilization coefficient and average power density,eventually maximizing the utilization of land resources.