METHOD FOR THE SHORT-TERM ADJUSTMENT OF THE OUTPUT OF A COMBINED-CYCLE POWER PLANT STEAM TURBINE, FOR PRIMARY FREQUENCY CONTROL

摘要

A method for the short-term adjustment of the output of a steam turbine of a combined-cycle power plant, includes: opening, respectively closing, a backed-up turbine valve of a pressure stage, according to a required change in output; comparing a desired pressure with a pressure measurement upstream of the turbine valve to measure pressure of steam mass flow flowing into the pressure stage; and opening, respectively closing, a feed line for introducing a variable proportion of water into the steam mass flow as soon as the pressure falls below or exceeds the desired pressure; the variable proportion of water is introduced into the steam mass flow until an adjusted desired steam temperature is reached, which is determined from the difference between a basic specified desired steam temperature and the default value of a controller which operates at least proportionally and evaluates the difference between the pressure measurement and the desired pressure.