| 摘要 |
PURPOSE:To prevent a change of the inlet steam pressure to a turbine, by controlling the closing speed of a turbine bypass valve performing a follow-up motion to the actual opening of a main steam control valve when its rapid opening instruction is input. CONSTITUTION:A signal v8, obtained by a speed deviation signal v3 and a pressure deviation signal v6 passing through a low value selector 14, controls a main steam control valve 3. While a turbine bypass valve opening instruction value v15, obtain by a deviation v11 between a pressure control instruction value v7 and the main steam control valve opening instruction value v8 and a deviation v14 between the instruction value v7 and a main steam control valve opening signal v9 passing through a high value selector 23, controls a bypass valve 6. In this way, a control device actuates the bypass valve 6 to start opening performing a follow-up motion to the main steam control valve if it starts closing by increasing the speed of a turbine while it is in pressure control operation, and the control device controls the bypass valve 6 to be closed at an equal changing speed by opening the main steam control valve 3 if the speed of the turbine begins to return to the reference value. |
