Optimum Design Of Weight Reduction For Main Frame Of Large Wind Turbine

With the increasing depletion of non-renewable energy and the enhancement of human environmental awareness,more and more attention has been paid to renewable energy.Although the global wind power industry has developed rapidly in recent decades,it has also exposed a series of problems.The domestic wind power industry started late and the wind turbine manufacturers are not mature in the design of the wind turbine components.The main frame safety margin is larg and the design process is not comprehensive.Meanwhile,the company has put forward requirements to reduce the manufacturing cost of the main frame.Therefore,the thesis addresses the problems of large safety margins of existing main frames,single design method and incomplete design process.Take the main frame of a large wind turbine as the research object,combine the finite element method and the related theoretical calculation method.Base on the Germanischer Lloyd’s register of certified standards and International Electrotechnical Commission standards.Use commercial optimization software and finite element software as tools.The system has been comprehensively studied from the optimization design of the main frame weight reduction to the actual production of the main frame.While reducing the weight of the main frame and saving manufacturing costs,it provides technical support and method guidance for the subsequent weight reducing optimization design of other wind turbine components.The main research contents of the thesis are as follows:(1)The basic theoretical knowledge of ultimate strength and fatigue life analysis of wind turbine components are introduced,include the theory of finite element ultimate strength analysis and damage accumulation theory of fatigue analysis.Take the main frame as an example,thesis points out how to improve the calculation accuracy and the fatigue life of the main frame in the optimized design for weight reduction,which provide support for the design of wind turbine components or other similar mechanical structures.(2)A realizable method for the design of wind turbine components is proposed.With the commercial optimization software as the design tool of the main frame structure,combined with the wind turbine certification standards and calculate the material distribution of the main frame under different extreme working conditions.Then,consider the positional relationship between the main frame and other components.Combine engineering experience to design the details of the main frame local configuration.It provides a practical engineering method for the design of the following main frame or other components of wind turbine.(3)A practical engineering method for weight reduction and optimization of the main frame is proposed.In the topology optimization design stage,builde a differentiation model of the main frame to improve the efficiency of topology optimization and shorten the design cycle of mainframe weight reduction optimization.In the calculation and verification stage of ultimate strength and fatigue life,a fine finite element model is established,which fully reflected the actual assembly relationship and load transfer mode of the main frame with other components,so as to improve the calculation accuracy of the model.The method can be extended to similar optimized configuration designs of wind turbine components or other machinery,provide a practical method for the modeling and analysis of such parts.(4)A practical engineering method for optimizing the local configuration of the main frame is proposed.Give a reasonable analysis and interpretation of the calculation results.Targete optimization and improvement measures for the local configuration of the main frame,so that the final main frame architecture meets the requirements of limits at the same time.This local configuration optimization method can be used as a reference method for complex configuration components in engineering design analysis.