The types of mechanical and thermal stresses on the first stage rotor blade of a turbine

Introduction: in this paper, the simulation of first stage of low pressure turbine for Nasiriya Power Plant was done to study the aerodynamic characteristic of steam along stage at load 70 MW, also the two types of mechanical stresses on the first stage rotor blade were studied in this paper. Materials and Methods:The material of blade was X20Cr13 stainless steel grade 1.4021. The first type of mechanical stresses which due to the steam pressure on the blade was analyzed. The seconds types of mechanical stresses that the centrifugal stresses on the blade. The AutoCAD software code was used for modeling the turbine stage, the dimensions and operational conditions were obtained practically from Nasiriya power plant and ANSYS (15.0) software was used to make simulate the turbine. Results and Discussion: The results showed that maximum steam velocity occurred at trailing edge of stationary blades and leading edge of rotating blades, also the maximum stresses occurred at the leading edge and trailing edge of root blade, the stresses due to the effect of centrifugal force is larger than the stresses due the pressure force. Conclusions: The maximum deformation occurred at tip of blade and minimum deformation depicted at root of blade.