| 摘要 |
PURPOSE:To achieve the extension of life by raising the steam temperature at a turbine inlet by means of steam for raising temperature supplied from the other unit at the time of changeover from a start-up system of starting time to a once- through system when D.S.S operation (a system in which operation is stopped at midnight and is started early in the morning) is carried out. CONSTITUTION:In a constant supercritical pressure once-through plant, the turbine inlet steam temperature of D.S.S unit comprising a secondary superheater 15, main steam pipe 16, main steam stop valve 17, steam regulating valve 18, turbine 19, etc. is kept at a prescribed value by opening a shutoff valve 25 installed in a main steam connecting pipe 23 branched from the other unit comprising a superheater 20, main steam pipe 21, turbine 22, etc., after D.S.S machine is started and initial load is charged, and before ramping (changeover from a startup system to a once-through system) is effected. And the steam temperature at the turbine inlet is raised by admitting high temperature steam from the other unit into the D.S.S unit by regulating a main steam temperature control valve 24 in response to a control signal from a main steam temperature controller 27. |
