Turbine blade is one of the three major parts of turbine runner (upper crown, lower ring and blade) which is most likely to fail. Its service life basically determines the service life of runner, and its manufacturing quality is very important. Combined with the hydraulic turbine blade produced by a heavy equipment manufacturing company in China, the flow field and temperature field are simulated by ProCAST software, the gating system is improved, and the improved gating system is verified. The stress field of hydraulic turbine blade is simulated by ProCAST software to analyze the stress and deformation of blade during solidification, so as to guide production practice.
Combined with the actual water turbine blade produced by sand casting, the gating system is improved through the simulation of flow field and temperature field, and the rationality of the improved gating system is verified. The main contents are as follows:
(1) According to the two-dimensional wood model diagram of hydraulic turbine blade, the three-dimensional solid diagram is established by UG. According to the design principle of gating system and riser, the gating system and riser of hydraulic turbine blade are designed.
(2) The flow field in the sand casting process of hydraulic turbine blade is simulated by ProCAST software. The simulation results are analyzed. It is concluded that turbulence will occur in the mold filling process, and the irrationality of the gating system is pointed out.
(3) According to the previous simulation results and the design principle of gating and riser, the gating system is redesigned and the low injection gating system is adopted. Then the flow field, temperature field and stress field of the turbine blade after the improved gating system are simulated to verify the rationality of the improved gating system. Through the simulation of temperature field, it is predicted that the shrinkage cavity and porosity casting defects existing in the sand casting process of hydraulic turbine blades are all concentrated at the riser. Through the simulation of stress field, the stress and deformation of hydraulic turbine blades during solidification are obtained. After analysis, the maximum deformation of hydraulic turbine blades is 50mm, which provides a basis for future production practice.