Research On Thermal Intensity And Fatigue Life Of Turbine Blades

As a large-scale power plant,gas turbine widely used in aviation,ship domain,power generation,chemical industry and various industrial fields.In the past twenty years,gas turbine has got extensive application and quick development in the field of ship power plant,in which field that has a great prospec.As an efficiency power system marine,the environment tenprecther and rotation speed of gas turbine are higer than other power systems in the same field,during its running time.Therefor,in order to ensure the safety and stability during the lifetime of the gas turbine,it is significantily to study for its fatigue life problems.turbine rotor blades is one kind of the important parts of the gas turbine,the complex structure and severe losd condition has forced it one of the high fatigue probability components of the gas turbine.In order to ensuring the reliability level of the gas turbine it is one of the core tasks to do the fatigue life evaluation and strength check of the turbine rotor blades.This paper analyzed the cycle-multiaxial fatigue life of turbine blade of marine gas turbine,and then study the various-factors influences on the fatigue life of turbine rotor blade of large marine gas turbine.First,collect the data of the loads which act on gas turbine blade through documentary.Analysis the different working conditions of gas turbine that possibly considering its work principl,then choose out the load state in the environmental condition that representative.Analysis the loads of turbine blade of marine gas turbine in different working conditions of different thermal loading state and different turbine of rotational speed.Lay the foundation for the following study on the fatigue life of marine gas turbine turbine rotor blade.Second,analyze the stress and strain of turbine rotor blade of marine gas turbine under different thermal load,centrifugal load and pressure load by using the ANSYS finite element method.And do the comparison of tress-strain distribution in different loads condition with controlling variable method,get the influence of each factor on the stress and strain of gas turbine blade.Ensure the dangerous positions and danger point may cause fatigue damage,basis on the analyzed results.Then,calculat the aerodynamic excitation of marine gas turbine turbine rotor bladea,then analysis the causes of induced vibration,got the expression of the induced vibration,determine the vibration load.Finally,analyze the vibration of the danger point with the infulence of thermal load,centrifugal load and pressure load,get the allowable cycle times under this kind of induced vibration.Analyze the fatigue life of marine gas turbine turbine rotor blades,then analyze the fatigue life under different working condition,get the influence of fatigue life of marine gas turbine turbine rotor bladea under different loads conditions.