Steam turbine overspeed protection system and steam turbine

摘要

The present invention relates to the technical field of power plant steam turbine safety, and discloses a steam turbine overspeed protection system and a steam turbine. The steam turbine overspeed protection system comprises: a drive gear (100) arranged to match a rotation speed of a rotor (10) of a steam turbine; a rotating shaft (201) parallel to an axis of the drive gear (100) and capable of rotating at a critical rotation speed; a protective gear (200) arranged on the rotating shaft (201) and forming a lead screw nut mechanism with the rotating shaft (201), and arranged to be capable of engaging with the drive gear (100) when the rotation speed of the drive gear (100) exceeds the critical rotation speed; and an operating rod (202) connected to the protective gear (200); wherein, when the drive gear (100) engages with the protective gear (200), the protective gear (200) can move in the axial direction of the rotating shaft (201) and thereby drive the operating rod (202) to move and produce an action that activates a protection device (300) for preventing steam turbine overspeed.