Design Of Cooling Duct Of 3.0MW Doubly-fed Wind Generator And Numerical Simulation Of Temperature Field

In recent years,as a kind of clean and cheap renewable resource,the wind energy develops rapidly.At the same time,doubly-fed wind generator has become one of the main Grid-connected wind generators for its light weight,small size and high quality of power supply.But with the increasing of the capacity of doubly-fed wind generator,and its physical design becomes more and more complex,besides,its engine room gets smaller and smaller,because of all the reasons,the cooling performance is badly affected,as a result,the security of operation and working will decrease.In this paper,the 3.0MW doubly-fed wind generator is chosen to be the study object,and the power losses in all parts of the generator,are analyzed,which are also regarded as the thermal load in the process of the generator cooling.According the hydro-mechanics,heat transfer theory,and heat dissipation charac teristics,the proper cooling scheme is chosen,and its cooling duct is also designed.Then set the 3D solid modeling by using Solid Work according to the size of the rotors,1/18 of which are taken as the study object.Secondly,the established model is imported into Fluent and set the boundary conditions and grid partition densities,and in order to analyze the regularities of distribution of the temperature in all parts of the generator,I take the calculated power losses as heat source,which will be used to calculated the accuracy of all parts of the generator.Finally,the change regularities of the temperature,pressure,heat transfer coefficient,frictional resistance coefficient,and Nusel coefficient of the cooling ducts in different wind speed will be discussed.The analysis result will be presented in pictures,through which the changes of the regularities of distribution of the temperature in all parts of the generator and fluid velocity.The change rules of the temperature in all parts of the generator can be got by the above analysis,and the get the optimum value of the air velocity in the cooling duct.The result shows that the total losses in all parts of the generator is about 53 kW,a nd that the regularities of distribution in temperature accord with the generator working requirements,besides,the design of the cooling duct can satisfy the maximum allowed temperature of the generator insulation class.The research results in this paper can offer references to the design of the wind generator cooling system.