| 摘要 |
PURPOSE:To make it possible to completely automate turbine run back control, by gradually reducing an opening degree of a cooling water flow control valve when at least one of condensate pumps is tripped, and gently decreasing a cooling water flow into a condenser. CONSTITUTION:A steam turbine plant includes a direct contact type condenser 5, a plurality of condensate pumps 6 and a control valve 8 for controlling a cooling water flow into the condenser. In the event that one of the condensate pumps 6 is tripped, an opening degree of a main steam control valve 2 is reduced to decrease an output of a turbine 3. In association with this, selectors 23 and 24 are switched, and a valve closing signal is formed by a change rate limiter 27 to close the control valve 8 through the selector 24 and an E/P converter 28. In this way, the cooling water flow into the condenser 5 is gently reduced, and accordingly it is possible to effect remarkably good turbine run back control. |
