Optimization for a steam turbine stage efficiency using a genetic algorithm

Based on the genetic optimization theory, a design method for the flow path of an axial flow steam turbine stage is presented. In this 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 the 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 determined 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 reveals the optimal geometric and aerodynamic parameters of the stage for maximum efficiency.