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US 2002/0054817 A1Published application
High efficiency blade configuration for steam turbine
AssigneeKabushiki Kaisha Toshiba
InventorsTadashi Tanuma, Taro Sakamoto
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AssigneeKabushiki Kaisha Toshiba
InventorsTadashi Tanuma, Taro Sakamoto
Estimating the term…
A steam turbine that passes more turbine driving steam by off-setting the turbine moving blade throat.pitch ratio before operation and, when a blade untwist is generated during operation, causing more turbine driving steam to flow by maintaining an appropriate value, and, at the same time causing the turbine moving blade throat.pitch ratio to swell by giving the blade untwisting angle to the blade cross-sections in regions where the aerodynamic loss is small. The steam turbine is one in which the throat.pitch ratio (S/T) distribution of a turbine moving blade is offset by forming a curve providing at least one minimal value and maximal value by giving blade twist angle to the blade cross-sections in the blade height direction from blade root to blade tip and, at the same time, the distribution of throat.pitch ratio (S/T) taking into consideration blade untwist generated during operation.
In a turbine nozzle blade assembly for a steam turbine which has a plurality of stages each provided with turbine moving blades attached to the turbine shaft and fixed turbine nozzle blades positioned axially adjacent the turbine moving blades, each of the turbine nozzle blades being twisted from the blade root to the blade tip, the improvement wherein the twist angles at blade cross-sections along the height of each turbine nozzle blade are differentially twisted to produce a distribution of throat.pitch ratio (S/T) along the turbine moving blade height direction from the blade root to the blade tip that follows a curve having at least one maximum located in a turbine nozzle blade height range of about 20% to about 80%.
Dependencies are inferred from the claim text.