小型变桨风力机启动性能研究

Study on Start-up Performance of Small Variable-pitch Wind Turbine

为研究某小型水平轴变桨风力机的启动性能,通过搭建风力机风洞试验台,分析不同桨距角对风力机静态扭矩、转速以及启动风速的影响,同时通过数值模拟仿真结果结合理论分析,研究风力机启动时桨距角变化过程中的相关气动性能。结果表明:风速分别保持在3~6 m/s不变时,随着桨距角的增加,风轮静态扭矩值呈先增大后减小的趋势,50°桨距角下的静态扭矩约为10°桨距角下静态扭矩的2.2倍;风轮静止时表现出与高速旋转状态下截然相反的气动性能,叶片叶根区域为启动扭矩主要动力产生区域;桨距角越小,叶根区域流动分离现象越明显,且分离点越靠近前缘,气动性能越差;40°桨距角时,可兼顾最小的启动风速和较大的旋转速度,测得最低启动风速为3.7 m/s。

In order to study the start-up performance of a small horizontal-axis variable-pitch wind turbine, a wind tunnel test platform was built to analyze the influence of different pitch angles on the static torque, rotational speed and starting wind speed of the wind turbine. The relative aerodynamic characteristics of the wind turbine during the change of pitch angle were studied by numerical simulation and theoretical analysis. Results show that when the wind speed is kept constant at 3~6 m/s,the static torque value of the wind rotor first increases and then decreases with the increase of the pitch angle, and the static torque at 50° pitch angle is about 2.2 times of that at 10° pitch angle. When the rotor is stationary, the aerodynamic performance is completely opposite to that in the high-speed rotation state, and the blade root area is the main power generation area for the starting torque. The smaller the pitch angle becomes, the more obvious the flow separation phenomenon in the blade root area is, the closer the separation point is to the leading edge, and the worse the aerodynamic performance is.At the pitch angle of 40°, the minimum starting wind speed and the larger rotation speed can be achieved, and the minimum starting wind speed is 3.7 m/s.