System suitable for FCB operation of thermal power steam turbine unit and working method

The invention relates to the technical field of thermal power generation, and discloses a system suitable for FCB operation of a thermal power steam turbine unit and a working method.The system comprises the steam turbine unit and a PCV valve arranged at the preset position of the steam turbine unit; the PCV valves comprise at least one of superheater PCV valves arranged on a preset group number of branch pipes led out of an inlet of a last-stage superheater of the unit; the main steam PCV valves are arranged on the preset groups of branch pipes led out of the main steam pipeline of the unit; and the reheating cold section PCV valves are arranged on the preset groups of branch pipes led out from the reheating steam pipeline of the cold section of the unit. According to the technical scheme, an existing steam turbine set has the FCB function, through the bypass pipeline, the PCV release valve and the reheating safety valve, rapid load shedding and redundant steam release of the steam turbine can be achieved, s