| 摘要 |
PURPOSE:To significantly lessen total pressure loss in a mixed pressure turbine by arranging a set of shutter members for shutting and opening a secondary vapor passage near the outlet end of the secondary vapor passage connected at a specified angle to the primary vapor passage of the turbine. CONSTITUTION:A mixed pressure turbine has a primary vapor passage 5 for allowing primary vapor A to flow in form the first stage 4 of the turbine. A secondary vapor passage 9 smoothly sloping to the downstream of and communicating with the passage 5 is formed at an intermediate stage of the turbine. The slope of the secondary vapor passage 9 is set so that the angle alpha formed between an extension line of an outlet end 9a of the passage 9 and the central axis of a turbine rotor falls within a range between zero and pi/3: 0<=alpha<=pi/3. In this case, a shutter member 19 consisting of both a ring-shaped rotary plate 20 projecting from a nozzle diaphragm outer ring 18 located on the downstream side of the passage 9 into the passage 9 and a ring-shaped fixed plate 21 projecting from a casing 10 located on the downstream side of the passage 9 is arranged at the said outlet end 9a so that the passage 9 can be opened or closed.
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