风力机组叶片覆冰数值模拟及其气动载荷特性研究

Study on Ice Numerical Simulation and Its Power Loss Characteristics for the Blades of Wind Turbine

大规模的风电基地接入电网后,风力机组叶片覆冰造成的能量损失、机组的非计划停机,给电力系统调度运行带来巨大风险,严重影响了电网的安全稳定运行。本文根据k-ε模型计算了叶片周围的空气流场,采用拉格朗日法计算了过冷水滴运动轨迹得到风力机组叶片表面各个控制体的局部撞击系数,利用质量平衡和能量平衡方程求解控制体的覆冰质量,结合覆冰时间推进法模拟了叶片覆冰过程。验证结果表明,本文叶片冰型计算结果可为叶片覆冰提供有效预测。最后,构建了3维叶片覆冰模型,采用FLUENT计算了不同类型覆冰的厚度对发电机组转矩和功率损失的影响,仿真发现,雾凇覆冰对转矩和功率损失的影响小;雨凇覆冰使发电机组转矩下降大,造成功率损失大。结论表明,本文对电网的安全、稳定、高效运行具有重要意义。

After the large-scale wind power base connected to the power grid,huge risks were brought to the dispatching operation of the power system due to the energy loss and unplanned downtime of the unit caused by iced wind turbine blade,the safe and stable operation of the power grid was seriously affected.The air flow field was acquired based on k-s model in this text,the move trajectories of the supercooled water droplets was calculated by adopting the Lagrange method,then the local impact factor for each control unit of the wind turbine blade surface was obtained.The controled ice mass was solved by using the mass balance and energy balance equation,and the process of blade ice was simulated by combining with the ice time propulsion method;It provides effective prediction for the ice of the blade,Finally,the 3d iced blade model was built,and the influence on the blade torque for different radial thickness of ice was calculated by using the fluent software,it is of great significance to the safe,stable and efficient operation for the power grid.