| 摘要 |
The present invention relates to a flexible inlet tube for a high and intermediate pressure steam turbine, and an object thereof is to prevent a temperature rise of an integrally constructed casing by steam cooling a reheat steam inlet tube by means of a double construction. To achieve this object, the flexible inlet tube is configured as described below. A casing 11 is provided with a main steam inlet tube 14 and a reheat steam inlet tube 1 constructed integrally with the casing 11. Main steam 30 flows into a high pressure turbine section 17 through the inlet tube 14, and reheat steam 31 flows into an intermediate pressure turbine section 19 through the inlet tube 1, by which a rotor 12 is driven. A double tube portion 2 is provided in the inlet tube 1 to form an annular groove 3. An expanded diameter portion 4 is provided at the lower end of the double tube portion 2, and a vertical sliding motion can be accomplished between the expanded diameter portion 4 and a flange 5 fixed to a thermal shield 21, so that thermal elongation is absorbed. Low-temperature steam flows into the annular groove 3 from an in-casing space 23 through a hole, circulates in the annular groove 3, and flows out to a steam passage in the intermediate pressure turbine section 19, by which the interior of the annular groove 3 is cooled, so that a temperature rise of the casing 11 can be prevented. <IMAGE> |
