| 摘要 |
PURPOSE:To hold a negative pressure state in a route from the ground portion of a turbine to a ground seal steam condenser when an exhauster is in a stop so that a smooth flow of steam is not interrupted and there is no possibility of causing lowering of efficiency or problems of occurrence of steam leakage, by providing a connecting tube between the ground seal steam condenser and a turbine condenser so that the pressure within the ground seal steam condenser can maintain a predetermined level even when the exhauster is in a stop. CONSTITUTION:A check valve 7 is fully closed in time coincidence with the stop of an air exhauster 3, whereas a connecting pipe 10 is fully opened. As a result, a ground seal steam condenser 4 is connected to a turbine condenser 8 through a connecting pipe 9, and the internal pressure of the condenser 4 is finally settled at a value balancing with the internal pressure of the condenser 8. Since the internal pressure is normally held at a value of 722mmHg which is close to absolute vacuum, while the turbine is in operation, the pressure within the condenser 4, when balancing with the condenser 8, assumes an equal value with the above described value, so that the route from a ground portion 2 to the condenser 4 assumes a stable negative pressure state. Hence, the flow of seal steam is not interrupted at all, and it is possible to cut off the flow of cycling steam flowing to the ground portion 2.
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