CFD Analysis Of Flow In Francis Turbine Of Sewage Treatment Plant Tailwater Power Station

Hydropower is renewable clean energy, which is an important component part of China's energy structure. In recent years, China's economic develops rapidly, as well as the development of industry,agriculture, and the accelerated pace of the urban infrastructure construction. Social tension in the demand for electricity has become pronounced contradiction. At the same time time, with the potential hydroelectric exploit more and more, we have less and less high water head resource. Therefore, more and more people pay attention to the development about low water head hydroelectric. In such circumstances, the first sewage treatment plant tailwater power station in our country has been put into use in Chongqing in September 2009. The project reflects on social development demand, energy sources saving, water environment protecting and etc. And it also conformed the relative policy of our country which are energy-saving and emission reduction and developing circular economy. As a demonstrating project, It will be great importance of reference and value to the same trade for launching circulation economic research.As a core component of a hydropower station, hydraulic turbine plays a vital role in the integration of a station.Research on the technology of hydraulic turbine is continuously increasing with the development of water electricity. However, in many domestic and foreign hydropower station, due to some technical problems, the malfunction of the water-turbine generator set still exisrt,which may lead to the damage of flowing parts. The effieient and steady performance of Francis turbine has been taken into more consideration with its increase in capacity,size and speed. It is essential to do further research on the internal flow field simulation.Therefore, studies of steady and unsteady flowin hydraulic turbine components are of importance to deeply understand the hydraulic turbine vibration intrinsic mechanism, improve the comprehensive hydraulic performance of the hydraulic turbine, and enhance the operating stability of the water-turbine generator set.The hydraulic turbine of the sewage treatment plant tailwater power station is taken as reference in this paper. The geometric model with whole flow passage of hydraulic turbine is built at first.Then the numerical simulation of internal flow is completed under the spplication of CFD software. The internal flow features and performance of hydraulic turbine is analysed according to the results.Main work of this paper can be listed as follow:Firstly, discharge apparatus'3-D geometric models are established according to actual hydraulic design parameters of a specific station by nigraphics software; leads all the hydraulic turbine models into the gambit software, and makes a mesh division of the discharge apparatus. Secondly, make reasearch of key steps before application of Fluent software, such as boundary setting,parameter selection,solution computation, ect. The the mesh file is introduced into software, it could be cauculated after setting boundaries.Thirdly, make an analyze of the francis hydraulic turbine's 3-D steady turbulent of the whole flow passage with numerical simulation method separately in peak discharge, proper discharge and minimum discharge of sediments free media, set up the francis hydraulic turbine's performance forecast method based on CFD analysis.Finally, the cauculation results should be made post-treatment, then we could get the velocity vector distribution , pressure equivalent distribution lines and turbulence intensityequivalent distribution lines. Flow state,velocity distribution and pressure variation. We could get the flowing information through compare and analyse internal flowing characteristics of hydraulic turbine. Then the performance of turbine could be evaluated quantitatively and qualitative.