Analysis On Characteristics Of 2MW Fan Blades Impact Of Extreme Temperature

With the deterioration of human living environment and the problem of energy crisis,governments pay attention to renewable energy,wind power depend on its unique strengths such as advanced technology,low cost,high safety factor,its becomes the most commonly used electricity production mode.China as the largest energy consuming country,in order to get out of the energy predicament,the Chinese government put forward the " Renewable energy development plan" and "The 13 th Five-Year plan" and other policies.The performance level of annual power output of wind generator mainly depends on the quality of blades,however some environment problem such as global warming and extremely weather has increased.For one thing,the extreme temperature will declined the performance of blade material,for another,the extreme temperature will increased the blade load.Therefore,it is necessary to consider the influence of extreme temperature on the fatigue design of the blade when it is used in the service life.This article through the experiment and theoretical deduction and other methods to determine the performance of the blade material,then used the UG software to established the blade model,then through the ACP software laid and solid the blade mode,eventually import to the ANSYS Workbench analysis,the main results are as follows:1)Considering of the performance of the glass fiber reinforced epoxy composite varies with temperature,this article basis on tensile test and theory,the relation between performance(composite tensile strength,elastic modulus,shear modulus and thermal expansion coefficient,thermal conductivity)and temperature is deduced.2)Through the thermal structural coupling analysis in ANSYS software found that: during the normal temperature(22℃)and rated wind speed(12m/s),the maximum equivalent stress of the blade and the shear stress occurs at the blade root and airfoil section joints and the root of blade,and the spanwise stress distribution along the blade.Extreme temperature simulation analysis shows that the low temperature environment will cause irreparable damage to the blade.3)The blade root analysis show,the first(45°),second(-45°),sixth(0°),twenty-eighth(90 °)layer were analyzed,the normal temperature and low temperature static results show that: the 0 ° layer under the maximum load,next is± 45 °,90 °is minimum.Compared with the performance of each layer under normal temperature,the maximum equivalent stress and shear stress of each layer are obviously increased under the condition of extremely low temperature.4)Summary of temperature and the blade performance data show that at-20 ℃,the maximum tensile strength of the load happened to the dangerous section of blade has far exceeded the blade material’s strength limit,so if the blade operating temperature is lower than-20 ℃,we should be reinforcement of the blade root,leading edge and trailing edge,and do a good job of blade insulation measures.5)The fatigue life analysis shows that low temperature is an important cause of early failure.When the ambient temperature is lower than-20 ℃,the blade is easy to produce cracks,resulting in the stress concentration point on the blade surface,resulting in low temperature brittle fracture.