Band structure and micro gas turbine having the same

Abstract

Disclosed are a band structure and a micro gas turbine having the same. An insert wall and a nozzle ring casing are respectively surrounded in part by a first band structure of a heat resistant material and a second band structure of a material that is identical or similar to the material of the first band structure to prevent thermal deformation of the insert wall and of the nozzle ring casing and a nozzle vane so as to maintain constant gaps between a blade tip of a turbine wheel and the insert wall and between a leading edge of the turbine wheel and the nozzle vane, thereby preventing reduction in both the power output of the turbine wheel even after a prolonged drive period and the operation efficiency of the micro gas turbine.

What is claimed is: 
     
         1 . A band structure surrounding a portion of an outer circumference of an insert wall or a nozzle ring casing in a micro gas turbine so as to prevent the insert wall or the nozzle ring casing from being enlarged due to thermal deformation. 
     
     
         2 . A micro gas turbine comprising:
 a turbine wheel;   a bearing casing provided in one side of the turbine wheel;   a nozzle ring casing supported by the bearing casing;   a combustor supplying combustion gas to the turbine wheel;   an insert wall disposed between the combustor and the turbine wheel to provide a channel wall for the combustion gas;   a nozzle vane provided between the insert wall and the nozzle ring casing to apply an aerodynamic force from the combustor to the turbine wheel; and   a first band structure surrounding a portion of an outer circumference of the insert wall to prevent the insert wall from being thermally deformed and enlarged.   
     
     
         3 . The micro gas turbine according to  claim 2 , further comprising a second band structure surrounding a portion of an outer circumference of the nozzle ring casing to prevent the nozzle ring casing and the nozzle vane from being thermally deformed and enlarged.