高原地区垂直轴风力机应用分析

青藏高原大部分地区属风能资源可利用区,但风向的多变特性限制了水平轴风力机的应用.从分析青藏高原地区风能资源分布情况及特征入手,依据高原独特的气象条件,采用理论分析方法探讨了空气密度对垂直轴风力机出力特性的影响规律,采用数值模拟方法对比海拔4 000 m处以及标准状态2种空气密度下垂直轴风力机的出力特性,归纳了光照辐射、覆冰、雷击等特殊因素对垂直轴风力机的影响.结果表明:空气密度对风能利用系数影响较小,但对输出功率影响较大.在相同风速条件下,同一垂直轴风力机在海拔4 000 m处(即ρ₁=0.843 7 kg/m³)输出功率约为在ρ₀=1.225 0 kg/m³地区的0.60~0.67倍.最后针对分析结果,提出了风轮改进设计方法及应对环境因素的改善措施.研究结果可对高原环境下垂直轴风力机的推广应用提供参考.

Analysis on application of vertical axis wind turbines in Qinghai-Tibet Plateau

Most parts of the Qinghai-Tibet Plateau belongs to a wind energy resources available area, but variable wind direction characteristic limits the use of horizontal axis wind turbine. Firstly, the distribution and characteristics of wind energy resources in the Qinghai-Tibet Plateau are analyzed. Then, the influence of air density on the output characteristics of vertical axis wind turbines is addressed by using analytical method according to the unique climatic conditions in the plateau. Thirdly, the output characteristics of a vertical axis wind turbine at the air density of 4 000 m altitude is predicted by employing numerical simulation and compared with these under the standard air state. Finally, the influences of special factors such as illumination, radiation, icing and lightning on the turbine are summarized. The results show that the air density has a little influence on the power coefficient, but has a great effect on the output power. At the same wind speed, the output power of the turbine at 4 000 m altitude with the air density of ρ₁=0.843 7 kg/m³ is about 0.60-0.67 times the power in the area of ρ₀=1.225 0 kg/m³. According to the results analyzed, the methods for updating wind turbine design and the improvement measures to deal with the environmental factors are put forward. The results in the paper can provide reference for the popularization and application of vertical axis wind turbines in plateau operational conditions. 