Seal structure, turbine machine having the same, and power generating plant equipped with the same

Abstract

A seal structure includes shrouds that are provided at tips of a plurality of blades on which a main flow of fluid impinges and that come into contact with adjacent shrouds to form a cylindrical shape; a sealing part connected to a structure body facing the shrouds; and a space that is defined by downstream sides of the shrouds, a downstream side of the sealing part, and a wall on a downstream side of the structure body, and that communicates with the main flow of fluid that has impinged on the blades. An end of the wall on the downstream side of the structure body is formed so as to be disposed a predetermined distance away from a shroud extension and away from a sealing-part extension and so as to be located on the opposite side of the shroud extension with respect to the sealing-part extension.

1 . A seal structure comprising:
 shrouds that are provided at tips of a plurality of blades on which a main flow of fluid impinges and that come into contact with adjacent shrouds to form a cylindrical shape;   a sealing part connected to a structure body facing the shrouds; and   a space that is defined by downstream sides of the shrouds, a downstream side of the sealing part, and a wall on a downstream side of the structure body and that communicates with the main flow of fluid that has impinged on the blades,   wherein an end of the wall on the downstream side of the structure body is formed so as to be disposed a predetermined distance away from a shroud extension extending toward the downstream side of the shrouds and away from a sealing-part extension provided substantially parallel to the shroud extension and extending toward the downstream side of the sealing part and so as to be located on an opposite side of the shroud extension with respect to the sealing part extension.   
     
     
         2 . The seal structure according to  claim 1 , wherein surfaces of the shrouds facing the structure body are provided substantially parallel to a flow direction of the main flow of fluid that has impinged on the blades. 
     
     
         3 . The seal structure according to  claim 1 ,
 wherein surfaces of the shrouds facing the structure body are inclined such that they gradually become farther away from the structure body along a flow direction of the main flow of fluid impinging on the blades.   
     
     
         4 . The seal structure according to  claim 1 ,
 wherein surfaces of the shrouds facing the structure body are inclined such that they gradually become closer to the structure body along a flow direction of the main flow of fluid impinging on the blades.   
     
     
         5 . A turbine machine comprising the seal structure according to  claim 1 . 
     
     
         6 . A power generating plant comprising the turbine machine according to  claim 5 . 
     
     
         7 . The seal structure according to  claim 2 ,
 wherein surfaces of the shrouds facing the structure body are inclined such that they gradually become farther away from the structure body along a flow direction of the main flow of fluid impinging on the blades.   
     
     
         8 . The seal structure according to  claim 2 ,
 wherein surfaces of the shrouds facing the structure body are inclined such that they gradually become closer to the structure body along a flow direction of the main flow of fluid impinging on the blades.   
     
     
         9 . A turbine machine comprising the seal structure according to  claim 2 . 
     
     
         10 . A power generating plant comprising the turbine machine according to Claim  claim 9 .