| 摘要 |
PURPOSE:To control a thermal stress generated on the rotor of a mixed pressure turbine under an optimum condition by making the piping of an inlet part in a high pressure steam system or a low pressure steam system to be connected with the piping of a steam extraction part through a control valve so as to control a steam temperature. CONSTITUTION:Thermal stress generated on a rotor is calculated by a temperature variation computing device 17 and a thermal stress computing device 18 in response to the values of a pressure and a temperature supplied from a pressure detector 16 and a temperature detector 28, provided in the primary stage of a high pressure steam system. And when the thermal stress is judged to exceed an allowable value by use of a rotor stress device 24, a valve 32 is closed and a valve 39 is opened by means of a valve adjustor 26 so as to input low pressure steam to a high pressure steam system, so that a steam temperature is lowered. Meanwhile, when the thermal stress is judged to exceed the other allowable value, a valve 35 is throttled and the value 39 is opened by means of the valve adjustor 26 so as to input a high pressure steam to a low pressure steam system, so that the steam temperature is raised. Owing to this arrangement, the thermal stress generated on the rotor of a mixed pressure turbine is controlled under an optimum condition. |
