After the power plant unit runs for a long time

there is a recurring phenomenon that load responses well at some valve position intervals while not ideal at some others.The direct reason is that the steam turbine governing valve's flow characteristics have deviated from the design value.In order to consistently match the unit flow characteristics setting with the actual situation

this paper proposed a new flow characteristic curve identification method

by means of historical data mining and analysis for a 660 MW unit

and combining with the features of the turbine's characteristic flow area.The application of this method in a 660 MW steam turbine regulating valve's flow characteristics identification shows a good performance

which piecewise-linearly optimized the corresponding flow management function

improved the linearity of the whole unit's flow characteristics in sequence valve mode

and readjusted the degree of valve overlap.This method provides a good reference for related turbine's flow identification and optimization.