Research On The Key Problems Of Tower Crane For Wind Turbine Hoisting

With the development of the global wind power industry,the megawatt-class wind turbines have been off the assembly line.This means that the weight of the wind turbines equipment is getting heavier and heavier,the height is getting higher and higher,and the cost of hoisting and the safety risk are also growing.At present,the wind turbines hoisting method is mainly using crawler cranes.But the method has obvious shortcomings in the environmental adaptability,economy and efficiency.To this end,the design of a tower crane with an attachment device to complete the hoisting work of megawatt-class wind turbines(including offshore wind turbines).The tower crane increases the stability,safety and efficiency of hoisting operations by multiplying with the wind turbines.That is of great significance and practical value to the hoisting of the wind turbines and its subsequent maintenance work.In this paper,a 6MW wind turbine is used as the hoisting object.And according to the main features of the 6MW wind turbine structure,a kind of attached tower crane with large hoisting height and large weight is developed.It is by adopting the rear boom and long standard section,rack and pinion climbing mechanism and removable chassis to achieve efficient wind turbines hoisting operations.In view of the characteristics and key technologies of this tower crane,the following research contents are determined.Firstly,this study carries out the design and research of rack and pinion climbing mechanism and attachment device.Then it analyzes the influence of rack on the load of the web number of the tower’s standard section under the gears in different arrangement positions,and the influence of the section inertia of the wind turbines’ tower tube on the load of the attachment device.These can provide a reference for the optimal structural design of gear rack and attachment device.Secondly,considering the particularity of the structure of the wind turbines’ tower tube,this syudy mainly carries out its nonlinear stability analysis under the premise of preventing the local buckling under the action of local concentrated load(adhesion)and ensuring the stability of the wind turbines’ tower tube during hoisting.The results show that the wind turbines’ tower tube in the hoisting process can provide attachment for the tower crane.Finally,according to the uncontrollability of the environmental factors of the wind turbine hoisting,this study analyzes the calculation conditions of the wind load in the non-working condition.The finite element analysis and verification of the fan tower and the whole machine structure are carried out to determine the survive wind speed of the tower crane.It is found that when the transverse wind load acts on the tower crane,its attachment does not affect the stability of the structure of the wind turbine,but also can improve the load of the structure.The research contents and results of this paper lay the foundation for the feasibility of using the attached tower crane to realize wind turbines hoisting,and also provide reference for the design of tower crane for wind turbine hoisting.