Gas turbine shroud cooling

Abstract

A shroud segment for a casing of gas turbine includes a body configured for attachment to the casing proximate a localized critical process location within the casing. The body has a leading edge, a trailing edge, and two side edges. The critical process location is located between the leading edge and the trailing edge when the body is attached to the casing. A cooling passage is defined in the body along one of the side edges with one of an inlet or an outlet proximate the critical process location. The cooling passage is configured large enough to cool the one side edge adjacent the cooling passage to a desired level during operation of the gas turbine. The critical process locations may be related to temperatures, pressures or other measurable features of the gas turbine environment when in use.

What is claimed is: 
     
         1 . A shroud segment for a casing of gas turbine comprising:
 a body configured for attachment to the casing proximate a localized critical process location within the casing, the body having a leading edge, a trailing edge, and two side edges, the body having a first surface for facing the casing and a second surface opposite the first surface for facing a hot gas path, the critical process location being located between the leading edge and the trailing edge when the body is attached to the casing; and   at least two cooling passages defined in the body related to one of the side edges, a first of the cooling passages having an inlet and extending to an outlet, one of the inlet or the outlet being adjacent the critical process location, a second of the cooling passages having an inlet and extending to an outlet, one of the inlet or the outlet being adjacent the critical process location, the first and second cooling passages being configured large enough to cool the one side edge to a desired level during operation of the gas turbine.   
     
     
         2 . The shroud segment of  claim 1 , wherein the first cooling passage has a first portion along the leading edge and a second portion along the one side edge. 
     
     
         3 . The shroud segment of  claim 2 , wherein the second cooling passage has a first portion along the one side edge and a second portion along the trailing edge. 
     
     
         4 . The shroud segment of  claim 1 , further including at least two additional cooling passages along the other of the side edges, the two additional cooling passages being substantially symmetrical to the at least two cooling passages with reference to a central plane of the body extending between the leading edge and the trailing edge. 
     
     
         5 . The shroud segment of  claim 1 , wherein the first cooling passage has a second outlet adjacent the critical process location along the other side edge. 
     
     
         6 . The shroud segment of  claim 5 , wherein the first cooling passage includes a first portion along the leading edge and a second portion along the one side edge, a third portion along the leading edge, and a fourth portion along the other side edge. 
     
     
         7 . The shroud segment of  claim 1 , wherein the second cooling passage has a second inlet adjacent the critical process location along the other side edge. 
     
     
         8 . The shroud segment of  claim 1 , wherein the second cooling passage includes a first portion along the one side edge and a second portion along the trailing edge, a third portion along the other side edge, and a fourth portion along the trailing edge. 
     
     
         9 . The shroud segment of  claim 1 , wherein the second cooling passage includes multiple outlets. 
     
     
         10 . The shroud segment of  claim 1 , wherein the body and first and second cooling passages are configured of a cast metal. 
     
     
         11 . A gas turbine comprising:
 a compressor section;   a combustion section downstream from the compressor section; and   a turbine section downstream from the combustion section, wherein the turbine section includes a casing defining a localized critical process location and a plurality of shroud segments circumferentially attached to the casing, each shroud segment including:   a body configured for attachment to the casing, at least one of the bodies having a leading edge, a trailing edge, and two side edges, the body having a first surface facing the casing and a second surface opposite the first surface facing a hot gas path, the critical process location being located between the leading edge and the trailing edge when the body is attached to the casing; and   at least two cooling passages defined in the body related to one of the side edges, a first of the cooling passages have an inlet and extending to an outlet, one of the inlet or the outlet being adjacent the critical process location, a second of the cooling passages having an inlet and extending to an outlet, one of the inlet or the outlet being adjacent the critical process location, the first and second cooling passages being configured large enough to cool the one side edge to a desired level during operation of the gas turbine.   
     
     
         12 . The gas turbine of  claim 11 , wherein the first cooling passage has a first portion along the leading edge and a second portion along the one side edge. 
     
     
         13 . The gas turbine of  claim 12 , wherein the second cooling passage has a first portion along the one side edge and a second portion along the trailing edge. 
     
     
         14 . The gas turbine of  claim 11 , further including at least two additional cooling passages along the other of the side edges, the two additional cooling passages being substantially symmetrical to the at least two cooling passages with reference to a central plane of the body extending between the leading edge and the trailing edge. 
     
     
         15 . The gas turbine of  claim 11 , wherein the first cooling passage has a second outlet adjacent the critical process location along the other side edge. 
     
     
         16 . The gas turbine of  claim 15 , wherein the first cooling passage includes a first portion along the leading edge and a second portion along the one side edge, a third portion along the leading edge, and a fourth portion along the other side edge. 
     
     
         17 . The gas turbine of  claim 11 , wherein the second cooling passage has a second inlet adjacent the critical process location along the other side edge. 
     
     
         18 . The gas turbine of  claim 11 , wherein the second cooling passage includes a first portion along the one side edge and a second portion along the trailing edge, a third portion along the other side edge, and a fourth portion along the trailing edge. 
     
     
         19 . The gas turbine of  claim 11 , wherein the second cooling passage includes multiple outlets. 
     
     
         20 . The gas turbine of  claim 11 , wherein the body and first and second cooling passages are configured of a cast metal.