| Summary: | 碩士 === 國立中央大學 === 機械工程研究所 === 100 === Current 2 MW wind turbine encounters an overheat problem in Taiwan’s tropic weather, thus this paper simulates the thermo-fluid field inside nacelle and generator of such wind turbine with FLUENT software and adopts feasible cooling solutions to reduce temperature inside nacelle and generator. The simplified geometry use in simulation is base on a realistic wind turbine, including nose, generator, nacelle and cooling pipe, others smaller sub-components are neglected.
The temperature of nacelle including generator is analyzed first and compared with realistic operating temperature of wind turbine. Based on this validation of simulation, the high temperature area is identified on the region of annular generator with maximum temperature located in the heat source inside the generator. Due to the influence of air flow from existing cooling pipe, large flow motion inside the annular upper region of generator and nose region is predicted, while in the rest region the flow is relatively slow, such uneven flow distribution leads to ineffective cooling for nacelle including generator.
Based on simulation results, three improving cooling options are suggested. First option is to increase inlet velocity of cooling pipe. Second approach is to install another cooling pipe into the annular bottom region of generator. Third option is to extend a branch pipe from the existing cooling pipe into annular bottom region of generator. The result is compare contour of temperature, velocity, pressure, and flow field in wind turbine. Increasing cooling velocity can reduce the temperature and enhance flow of annular upper region of generator, which increase the pressure too, but the temperature drop in other flow region is limited. Installing cooling duct alone can lead to temperature increased in annular upper region of generator, but it can effectively improve flow in annular bottom region of generator. Extended branch pipe from cooling pipe and enhanced velocity to 12 m/s can reduce temperature and increased flow motion inside nacelle and generator. This option is most effective in cooling and should be adopted.
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