| 摘要 |
PURPOSE:To evade the operation stop of a steam turbine due to abnormality of a servo valve in operation as much as possible by arranging a servo valve sequence for normal operation consisting of specific valves coupled directly and a backup servo valve sequence in parallel. CONSTITUTION:The operating hydraulic system for a hydraulic cylinder 2 which drives the steam valve 1 is provided with the servo valve sequence A for normal operation consisting of front-end solenoid valve, servo valve, back-end solenoid valves 4A, 3A, and 5A, and 4B, 3B, and 5A in series connection relation, and the backup servo valve sequence B. Then, when the valve sequence A is faulty, the valve sequence B is put in operation by switching to replace an abnormal part of the valve sequence A where the fault occurs during operation, and the operation stop of the steam turbine due to abnormality of the servo valve in operation is evaded as much as possible. |
