Patent Publication Number: US-11035247-B2

Title: Turbine apparatus and method for redundant cooling of a turbine apparatus

Description:
FIELD OF THE INVENTION 
     The present invention is directed to turbine apparatuses, turbine nozzles, and turbine shrouds. More particularly, the present invention is directed to turbine apparatuses, turbine nozzles, and turbine shrouds including a redundant cooling configuration. 
     BACKGROUND OF THE INVENTION 
     Gas turbines operate under extreme conditions. In order to drive efficiency higher, there have been continual developments to allow operation of gas turbines at ever higher temperatures. As the temperature of the hot gas path increases, the temperature of adjacent regions of the gas turbine necessarily increase in temperature due to thermal conduction from the hot gas path. 
     In order to allow higher temperature operation, some gas turbine components, such as nozzles and shrouds, have been divided such that the higher temperature regions (the fairings of the nozzles and the inner shrouds of the shrouds) may be formed from materials, such as ceramic matrix composites, which are especially suited to operation at extreme temperatures, whereas the lower temperature regions (the outside and inside walls of the nozzles and the outer shrouds of the shrouds) are made from other materials which are less suited for operation at the higher temperatures, but which may be more economical to produce and service. 
     Gas turbines typically operate for very long periods of time. Service intervals generally increase with time as turbines advance, but current turbines may have combustor service intervals (wherein combustion is halted so that the combustor components may be serviced, but the rotating sections are generally left in place) of 12,000 hours or more, and full service intervals (wherein all components are serviced) of 32,000 hours or more. Unscheduled service stops impose significant costs and reduce the gas turbine reliability and availability. 
     Incorporation of gas turbine components, such as nozzles and shrouds, which have high temperature regions and low temperature regions, may result in unscheduled service stops in the event where a high temperature portion fails (the high temperature portions being subjected to operating conditions which are more harsh than the operating conditions to which the low temperature portions are subjected), as the low temperature portions may be unable to survive in the turbine without the protection afforded by the failed high temperature portion until the next scheduled service interval. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In an exemplary embodiment, a turbine apparatus includes a first article and a second article. The first article includes at least one first article cooling channel. The second article is disposed between the first article and a hot gas path of a turbine, and includes at least one second article cooling channel. The at least one first article cooling channel is in fluid communication with and downstream from a cooling fluid source, and the at least one second article cooling channel is in fluid communication with and downstream from the at least one first article cooling channel. 
     In another exemplary embodiment, a method for redundant cooling of a turbine apparatus includes flowing a cooling fluid from a cooling fluid source through at least one first article cooling channel disposed in a first article, exhausting the cooling fluid from the at least one first article cooling channel into at least one second article cooling channel disposed in a second article, and flowing the cooling fluid through the at least one second article cooling channel. The second article is disposed between the first article and a hot gas path of a turbine. 
     Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a turbine apparatus, according to an embodiment of the present disclosure. 
         FIG. 2A  is a perspective schematic view of a second portion of a turbine apparatus including a plurality of heat exchange channels, viewed from the first portion adjacent side, according to an embodiment of the present disclosure. 
         FIG. 2B  is a perspective schematic view of the second portion of a turbine apparatus of  FIG. 2A , viewed from the hot gas path adjacent side, according to an embodiment of the present disclosure. 
         FIG. 3  is a schematic view of the second portion of a turbine apparatus including cross-flow cooling channels, according to an embodiment of the present disclosure. 
         FIG. 4  is an exploded perspective view of a shroud assembly, according to an embodiment of the present disclosure. 
         FIG. 5  is an exploded perspective view of a nozzle, according to an embodiment of the present disclosure. 
     
    
    
     Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Provided are gas turbine apparatuses, such as turbine nozzles and turbine shrouds. Embodiments of the present disclosure, in comparison to apparatuses and methods not utilizing one or more features disclosed herein, decrease costs, increase efficiency, improve apparatus lifetime at elevated temperatures, decrease non-scheduled service outages, increase turbine service intervals, or a combination thereof. 
     Referring to  FIG. 1 , in one embodiment, a turbine apparatus  100  includes a first article  102  and a second article  104 . The first article  102  includes at least one first article cooling channel  106 . The second article  104  includes at least one second article cooling channel  108 , and is disposed between the first article  102  and a hot gas path  110  of a turbine (not shown). The at least one first article cooling channel  106  is in fluid communication with and downstream from a cooling fluid source  112 , and the at least one second article cooling channel  108  is in fluid communication with and downstream from the at least one first article cooling channel  106 . 
     The first article  102  may include any suitable composition, including, but not limited to, a metallic composition. Suitable metallic compositions include, but are not limited to, a nickel-based alloy, a superalloy, a nickel-based superalloy, an iron-based alloy, a steel alloy, a stainless steel alloy, a cobalt-based alloy, a titanium alloy, or a combination thereof. 
     The second article  104  may include any suitable composition, including, but not limited to, a refractory metallic composition, a superalloy composition, a nickel-based superalloy composition, a cobalt-based superalloy composition, a ceramic matrix composite composition, or a combination thereof. The ceramic matrix composite composition may include, but is not limited to, a ceramic material, an aluminum oxide-fiber-reinforced aluminum oxide (Ox/Ox), carbon-fiber-reinforced carbon (C/C), carbon-fiber-reinforced silicon carbide (C/SiC), and silicon-carbide-fiber-reinforced silicon carbide (SiC/SiC). 
     In one embodiment, the second article  104  includes a thermal tolerance greater than a thermal tolerance of the first article  102 . As used herein, “thermal tolerance” refers to the temperature at which material properties relevant to the operating of the turbine apparatus  100  are degraded to a degree beyond the useful material capability (or required capability). 
     The cooling fluid source  112  may be any suitable source, including, but not limited to, a turbine compressor (not shown) or an upstream turbine component (not shown). The cooling fluid source  112  may supply any suitable cooling fluid  114 , including, but not limited to, air. 
     The first article cooling channel  106  and the second article cooling channel  108  may, independently, include any suitable cross-sectional conformation, including, but not limited to circular, elliptical, oval, triangular, quadrilateral, rectangular, square, pentagonal, irregular, or a combination thereof. The edges of the first article cooling channel  106  and the second article cooling channel  108  may, independently, be straight, curved, fluted, or a combination thereof. The first article cooling channel  106  and the second article cooling channel  108  may, independently, include turbulators  116 , such as, but not limited to, pins (shown), pin banks, fins, bumps, and surface textures. 
     In one embodiment, the at least one first article cooling channel  106  includes a minimum first cooling fluid pressure and the at least one second article cooling channel  108  includes a second minimum cooling fluid pressure. Each of the first minimum cooling gas pressure and the second minimum cooling fluid pressure are greater than a hot gas path pressure of the hot gas path  110 . 
     In another embodiment, the at least one second article cooling channel  108  includes a flow restrictor  118 . The flow restrictor  118  restricts a flow of cooling fluid  114  through the at least one first article cooling channel  106 . 
     In one embodiment, the at least one first article cooling channel  106  includes at least one exhaust port  120 , the at least one second article cooling channel  108  includes at least one inlet  122 , and the at least one exhaust port  120  is coupled to the at least one inlet  122 . The flow restrictor  118  may include an inlet  122  having a narrower orifice that the exhaust port  120 . The coupling of the at least one exhaust port  120  to the at least one inlet  122  may be a hermetic coupling or a non-hermetic coupling. In a further embodiment, a sealing member  124  is disposed between the at least one exhaust port  120  and the at least one inlet  122 . The sealing member  124  may be any suitable seal, including, but not limited to, an elastic seal. As used herein, “elastic” refers to the property of being biased to return toward an original conformation (although not necessarily all of the way to the original conformation) following deformation, for example, by compression. Suitable elastic seals include, but are not limited to, w-seals (shown), v-seals, e-seals, c-seals, corrugated seals, spring-loaded seals, spring-loaded spline seals, spline seals, and combinations thereof. 
     In another embodiment, the at least one second article cooling channel  108  includes at least one outlet  126 , the at least one first article  102  includes at least one recycling channel  128 , and the at least one outlet  126  is coupled to the at least one recycling channel  128 . The at least one recycling channel  128  may be in fluid communication with a downstream component  130 . 
     In one embodiment, a method for redundant cooling of a turbine apparatus  100  includes flowing a cooling fluid  114  from the cooling fluid source  112  through the at least one first article cooling channel  106 , exhausting the cooling fluid  114  from the at least one first article cooling channel  106  into the at least one second article cooling channel  108 , and flowing the cooling fluid  114  through the at least one second article cooling channel  108 . Exhausting the cooling fluid  114  may include exhausting the cooling fluid  114  from at least one exhaust port  120  of the at least one first article cooling channel  106  into the at least one inlet  122  of the at least one second article cooling channel  108 . 
     In the event of a failure of the second article  104 , flowing the cooling fluid through the at least one first article cooling channel  106  may provide sufficient cooling to maintain a surface  132  of the first article  102  proximal to the hot gas path  110  at a temperature within a thermal tolerance of the first article  102  under operating conditions of the turbine for a predetermined length of time. The predetermined length of time may be any suitable length of time, including, but not limited to, a combustor service interval or a full service interval of the turbine. Suitable combustor service intervals may be an interval of at least 10,000 hours, alternatively at least 12,000 hours, alternatively at least 16,000 hours. Suitable full service intervals may be an interval of at least 20,000 hours, alternatively at least 24,000 hours, alternatively at least 32,000 hours. 
     In another embodiment, the cooling fluid  114  is flowed from the at least one second article cooling channel  108  into at least one recycling channel  128 . In a further embodiment, the cooling fluid  114  is flowed from the at least one recycling channel  128  to at least one downstream component  130 . The flow of cooling fluid  114  may be used for any suitable purpose, including, but not limited to, cooling the at least one downstream component  130 . 
     Referring to  FIGS. 2A and 2B , in one embodiment, the at least one second article cooling channel  108  includes a feed plenum  200  downstream from and in fluid communication with the first article cooling channel  106 , and a plurality of heat exchange channels  202  downstream from and in fluid communication with the feed plenum  200 . The at least one second article cooling channel  108  may further include an outlet plenum  204  downstream from and in fluid communication with the plurality of heat exchange channels  202 . The at least one second article cooling channel  108  may also include, in lieu or in addition to the outlet plenum  204 , and in lieu or in addition to an outlet  126  connected to a recycling channel  128 , a plurality of exhaust holes  206  in fluid communication with the hot gas path  110 . The plurality of exhaust holes  206  may be arranged and disposed to form a film barrier  208  between the second article  104  and the hot gas path  110 . In another embodiment (not shown), the at least one first article cooling channel  106  includes a feed plenum  200  downstream from and in fluid communication with the cooling fluid source  112 , and a plurality of heat exchange channels  202  downstream from and in fluid communication with the feed plenum  200 . The at least one first article cooling channel  106  may further include an outlet plenum  204  downstream from and in fluid communication with the plurality of heat exchange channels  202 . 
     Referring to  FIG. 3 , in one embodiment, the at least one second article cooling channel  108  includes a first cross-flow cooling channel  300  and a second cross-flow cooling channel  302 . The first cross-flow cooling channel  300  includes a flow vector  304  across the second article  104  in a first direction  306 , the second cross-flow cooling channel  302  includes a flow vector  304  across the second article  104  in a second direction  308 , and the second direction  308  is opposite to the first direction  306 . In another embodiment (not shown), the at least one first article cooling channel  106  includes a first cross-flow cooling channel  300  and a second cross-flow cooling channel  302 . The first cross-flow cooling channel  300  includes a flow vector  304  across the first article  102  in a first direction  306 , the second cross-flow cooling channel  302  includes a flow vector  304  across the first article  102  in a second direction  308 , and the second direction  308  is opposite to the first direction  306 . 
     Referring to  FIG. 4 , in one embodiment the turbine apparatus  100  is a shroud assembly  400 , the first article  102  is an outer shroud  402 , and the second article  104  is an inner shroud  404 . 
     Referring to  FIG. 5 , in another embodiment the turbine apparatus  100  is a nozzle  500 , the first article  102  is a spar  502 , and the second article  104  is a fairing  504 . 
     While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.