ELECTROHYDRAULIC REDUCTION SYSTEM FOR SNOWLING THE REQUIREMENTS IN AN APPROACH REQUIREMENT

摘要

An electrohydraulic emergency trip system and method, which rapidly closes the steam inlet valves to the turbine in response to one of a plurality of predetermined contingencies that are sensed by redundant devices is disclosed. The system is energized electrically by two independent power sources in a failsafe arrangement, both of which must fail to result in an unwarranted trip. Hydraulically, the system includes first and second trip valve means, both of which must operate to trip the turbine, and each of which are energized by one of the independent power sources. A test and indication panel is provided for selectively testing the response of the system to the occurrence of the predetermined contingencies and includes alarms and indications of system condition. Contingency simulation means are provided for subjecting each of the contingency sensing devices to a respective emergency trip environment during operation and the response of the system thereto without affecting the operational condition being simulated, and permitting the system to remain responsive to a trip contingency.