| 摘要 |
PURPOSE:To prevent the occurrence of thermal stress and the deformation of diaphragms and a casing owing to the unevenness of heat transfer in the non-nozzle portions of the diaphragms, by providing hollow portions for each non-nozzle portion of each diaphragm, in a steam turbine having a partial injection stage. CONSTITUTION:A turbine stage comprises a rotor shaft 1, a disc 2, a buckets 3 planted thereon, the rotary portion of a shroud ring 4 which binds the buckets by several and several, a nozzle 5, diaphragms which support the nozzle and consist of an inner ring 6 and an outer ring 7, and the stationary portion of a casing 8 in which the plural diaphragms are included. And each diaphragm comprises a nozzle portion (arc angle alpha) in which steam passes through and a non-nozzle portion, and its structure is half-divided into an upper half 9 and an lower half 10. In this case, hollow portions 11a, 11b are formed at each non-nozzle portion of each diaphragm. And the axial widthes of the diaphragms are determined so as to narrow the clearance of the front and rear buckets for favorable distance.
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