Oil system is an important part to ensure the normal operation of the unit.Oil turbine is the core components of oil system for large-capacity steam turbine group over 600 MW.It was made currently through introducing technical drawings,but its internal flow mechanism and design method were few studied.Based on basic structure and operating principle of oil turbine components,reference to the design theory of radial and impulse turbine,the fundamental principle model of oil turbine was established by using velocity triangles and the impulse theorem.Its characteristic equation and key effect factors were presented,and it was verified through hydraulic performance numerical test model.On this basis,the parametric design model of the oil turbine was established.The intrinsic properties of oil turbine were found.Relative design principles were offered to oil turbine design.
