| 摘要 |
PURPOSE:To simplify the structure of a casing and as well as reduce the fluid loss by a structure wherein a part of the periphery of the casing of an upperstream side stage group is formed in double shell structure in a mixed pressure steam turbine. CONSTITUTION:Lowerstream side stage groups 24 and 25 are provided at both the sides of the upperstream side stage group 23 in the manner of double-flow. A part of the periphery of the casing 20 at the part falling on the upperstream side stage group is formed in double shell structure so as to shape a steam passage 30 with closed structure between walls. Steam pipings 34 and 35 for feeding primary and secondary steams are respectively connected to a casing 22 formed in single shell structure. In such a manner as mentioned above, the simplification of the structure of the casing can be resulted. Furthermore, because the primary steam is flowed through the steam passage 30 in the lower side stage group 24 and mixed with the secondary steam, the flow rate of the primary steam passing through the steam passage 30 can be reduced and the reduction of fluid loss can be resulted. |
