The Design Of Front Support Structure Of Aero-engineering Gas Turbine

The aero-engineering gas turbine refers to a gas turbine that is transformed from an aero-engine as a parent aircraft for power generation,ground power,and ship power.The aero-engineering gas turbine covers multiple power levels below 50 MW.Compared with the ground heavy-duty gas turbine,it has the advantages of small size,light weight,fast start-up,flexible adjustment,high efficiency,strong fuel adaptability and easy maintenance.According to the market demand,this article has developed a gas turbine.The gas turbine is a two-shaft front output gas turbine that has been modified from a turbofan engine.The overall design is to eliminate the low pressure compressor unit,retain the core machine,use the original low pressure turbine structure as the power turbine and add the front output shaft.Since the front support is cancelled along with the low pressure compressor unit,the critical speed of the low pressure shaft system changes,and a new front bearing is required to ensure the critical speed and absorb the vibration strain energy.Taking the overall design of a gas turbine as the design goal,the newly added front support components are designed.According to the design guidelines,the overall layout design of various front bearing components(including front bearing casing,front fulcrum bearing,bearing cavity sealing system and lubrication system,etc.)is first developed,and then the appropriate scheme is selected through comparison.The rotor dynamics calculation results of the solution shafting are selected.After completing the overall design plan,the detailed design of each component system is carried out according to the design criteria of each component system,and the structural design of the front bearing casing,the front fulcrum bearing,the bearing cavity sealing system and the lubrication system are completed.After completion,the finite element method is used to calculate the bearing stiffness of the front bearing casing and the front fulcrum bearing,and the stiffness is determined to meet the rotor dynamics calculation requirements of the shafting system;The performance calculation of the bearing cavity sealing system is performed,and the leakage of the sealing system is3.67 g/s.Meet the requirements of the design criteria for leakage less than 5 g/s;Perform performance calculations on the lubrication system,the newly added oil flow path has no effect on the entire fuel supply system,and meets the requirements for new seals and point bearings cooling requirements.According to the calculation results,the front support design is determined to meet the low-pressure rotor performance requirements.