Research On Hydrodynamic Design Method Of Oil Turbine And Its Applications

Oil system plays a crucial role in safe operation of thermal power plant units.With the development of steam turbine unit towards to the supercritical and ultra-supercritical machine type such as 600 MW and 1000 MW,the oil system consisted of main oil pump,booster pump and oil turbine has become the development tendency of large capacity steam turbine unit.As one of the key equipment of the oil system,oil turbine plays a key role in the stability of the oil system.However,China has not owned the mature oil turbine design methods so far.So the methods and theories of how to determine the geometric parameters of the flow channel are one of the technical issues needed to be solved urgently.According to the independent innovation and research needs of the oil system,combined with a series of technologies that urgent need for the 1000 MW class machine type,the topics,such as the theories and methods of hydrodynamic design of oil turbine digital design technology,multi-condition numerical simulation,prediction of performance and so on had been systematically researched.Based on the analysis of different working principle and special regulation performance between oil turbine and other prime mover such as steam turbine and hydraulic turbine,a design method of oil turbine had been proposed.Firstly,the oil turbine flow channel was preliminarily designed by the use of fluid dynamics digital methods.Secondly,the structures of each oil turbine components are parametrically designed according to their digital design model Finally,after numerical simulation and performance prediction of the preliminary designed oil turbine,an optimization scheme was selected in the iteration process of “preliminary design-numerical simulation and performance prediction-modify the design”,in order to achieve the design requirements.To verify the feasibility of the proposed oil turbine design methods,the design theories and methods were used for the development of independent innovation of1000 MW steam turbine oil system.Combined with the normal operation conditions and the increasing flow operation conditions of 1000 MW steam turbine oil system,two oil turbines that meeting the performance requirements were designed and the design cycle is shorten,which reduces development costs.In the oil system test bench of Dong Fang Steam Turbine Co.Ltd.,two oil turbines' adapted oil system were respectively tested in real machine linkage tests in order to verify the reliability of the oil turbine performance prediction method.It can be seen that the oil turbine hydrodynamic performance completely meets the design requirements according to the numerical simulation performance prediction results being fully compatible with the experimental results through the comparison.It has proved that the proposeddesign method in this paper is feasible,and the numerical simulation and performance prediction are reliable.In this paper,oil turbine has been successfully applied to the actual project of1000 MW steam turbine unit self-developed by Dong Fang Steam Turbine Co.Ltd.and solved the adapted key technical problems of 1000 MW steam turbine and make up for the blank of oil turbine design method and theoretical research.At the same time,it is significance for all domestic oil turbine technology and independent innovation,breaking the foreign monopoly,the formation of China's own intellectual property and so on.