Research On A Francis Turbine With Super-low Specific Speed Applied In Cooling Towers

The consumption power of fan motor in industrial cooling tower is very large and there is usually a certain suplus energy wasted in the circulating water.Through the analysis of the environment that the cooling tower work in,with further study of characterstics in the traditional power generation turbine,and reference to traditional design theory of francis turbine,a new good performance turbine is developed to replace the cooling tower fan motor by the method of numerical simulation to achieve the goal of energy saving.The suitable turbine type in cooling tower is determined mixed-flow through the analysis of working environment characteristics. Then the geometric parameters of runner are designed according to the geometric parameters of the flow channel of the hydraulic model that has similar head and specific speed as well as the excellent performance. And flow parts such as fixed guide vane, spiral case and draft tube were preliminarily designed.Initial program of the turbine is modeled three-dimensionally and meshed properly. The initial blades and other flow parts are adjusted according to the simulation results until the head and the efficiency of the turbine meet the design requirements.Performance curves of head, efficiency of the optimal solution in different flow were gained by numerical computation. The new turbine studied in this paper not only can achieve the goal of energy saving, but also provide reference of reasonable use of surplus energy for the other industry.