Abstract: Based on the genetic optimization theory, a design method for the flow path of an axial flow steam turbine stage is presented. In the method, the maximum efficiency of the stage is taken as the objective, a series of functions are taken as constraints and the optimal geometric and aerodynamic parameters are solved using genetic algorithm process. The efficiency and constraints evaluation are performed using a program for the thermodynamic calculation of steam turbine stages in the design condition. The fitness of each individual is composed by the turbine efficiency and a penalty function containing the constraints. The proposed method is applied to the design of a real steam turbine stage. The results show that the new method successfully searched out the optimal geometric and aerodynamic parameters of the stage had maximum efficiency.

Key words: Genetic algorithm, Optimum design, Steam turbine, Through flow section