The Improvement Research For Aerodynamic Performance Of Inlet Path In An Industrial Steam Turbine

Industrial steam turbine is widely used in all fields of national economy and plays an important role in waste heat recovery and energy cascade utilization.Industrial steam turbines generally adopt the structure of lifting plate type control valve,and the structure of inlet path is more complex,so the pressure loss is larger,and the steam flow at the outlet of nozzle chamber is more uneven.In this paper,the inlet path of an industrial turbine is taken as the research object,and the structure of the inlet path is improved by means of numerical simulation,which reduces the pressure loss of the inlet path,provides better conditions for the control stage,improves the efficiency of the control stage.In this paper,the numerical simulation of the original inlet path in the fully open condition of the control valve is carried out,and it is found that there are a large number of low-speed vortices in the flow field.The reason is that the structure of the inlet path does not adapt to the fluid,and there are many structures of sudden expansion,turning and blocking.The structure of the inlet pipe,the main steam valve chamber,the diffuser section of the main steam valve and the nozzle chamber were improved,and the diversion structure was added.The pressure loss of steam inlet decreased by 58.3%,the pressure inhomogeneity of nozzle chamber decreased by55.6%,and the deflection degree of steam flow decreased by 57%.In order to calculate the influence of the improvement of the inlet path on the control stage,the inlet path and the control stage are numerically simulated.Finally,a comprehensive evaluation of the performance of the inlet path is obtained.The efficiency of the improved control stage is increased by 3.7%,and the efficiency of the inlet path and the control stage is increased by 6.5%.