Coolant delivery via an independent cooling circuit

Abstract

The present invention discloses an implementation of an independent cooling circuit for selectively delivering a cooling fluid to components of a gas turbine system. The independent cooling circuit includes: at least one coolant feed channel fluidly connected to a cooling fluid supply source; and a cooling channel interconnect circuit including: a cooling channel interconnect circuit embedded within an outer wall of the component; an impingement plate; and a plurality of feed tubes connecting the impingement plate to the outer wall of the component and fluidly connecting the cooling fluid supply source to the cooling channel interconnect circuit; wherein cooling fluid flows through the plurality of feed tubes into the cooling channel interconnect circuit only in response to the formation of a notch in at least one of the cooling channels exposed in the outer wall of the component.

Description

[0001] Statement Regarding Federally Sponsored Research or Development

[0002] This invention was made with government support under Contract No. DE - FE0031611 awarded by the U.S. Department of Energy. The government has certain rights. BACKGROUND OF THE INVENTION

[0003] This disclosure generally relates to turbine systems and, more particularly, to the delivery of a cooling fluid via a separate cooling circuit to components of a gas turbine system.

[0004] A gas turbine system is an example of a turbine that is widely used in fields such as power generation. Conventional gas turbine systems typically include a compressor section, a combustor section, and a turbine section. During operation of the gas turbine system, various components in the system such as turbine blades, nozzle airfoils, and shroud segments are subjected to high - temperature gas flows, which can cause component failure. Since higher - temperature gas flows generally result in increased performance, efficiency, and power output of the gas turbine system, it is advantageous to cool the components that are subjected to high - temperature gas flows to allow the gas turbine system to operate at elevated temperatures and to extend the life of the components of the gas turbine system.

[0005] Cooling is typically provided by directing a flow of cooling fluid through internal channels formed in the components of the gas turbine system (e.g., convective cooling, impingement cooling, etc.). In many cases, the cooling fluid is provided by bleeding off a portion of the air discharged by the compressor section of the gas turbine system.

[0006] Thermal barrier coatings (TBCs) are typically applied to components of gas turbine systems to provide a protective thermal shield, prevent damage due to high temperatures, and extend component life by reducing oxidation and thermal fatigue. Spalling of the TBC is a common problem in gas turbine systems. When the TBC spalls, portions of the TBC may break off and detach from the component, exposing the underlying surface to high temperatures and damage (e.g., wall notches). SUMMARY OF THE INVENTION

[0007] One aspect of the present disclosure relates to a separate cooling circuit for selectively delivering a flow of cooling fluid to components of a gas turbine system, the separate cooling circuit comprising: a cooling channel interconnect circuit embedded within an outer wall of the component; an impingement plate; and a plurality of feed tubes that connect the impingement plate to the outer wall of the component and fluidly couple a source of cooling fluid to the cooling channel interconnect circuit; wherein the cooling fluid flows through the plurality of feed tubes into the cooling channel interconnect circuit only in response to the formation of a notch in the outer wall of the component that exposes at least one of the cooling channels.

[0008] Another aspect of the present disclosure relates to a cooling system that includes: components of a gas turbine system; and an independent cooling circuit for selectively delivering a cooling fluid to the components of the gas turbine system, the independent cooling circuit including: a cooling channel interconnect circuit embedded within an outer wall of the component; an impingement plate; and a plurality of feed tubes that connect the impingement plate to the outer wall of the component and fluidly couple a source of the cooling fluid to the cooling channel interconnect circuit; wherein the cooling fluid flows through the plurality of feed tubes into the cooling channel interconnect circuit only in response to the formation of a notch in the outer wall of the component that exposes at least one of the cooling channels.

[0009] Another aspect of the present disclosure relates to a method for reducing spallation-related damage to components of a gas turbine system, the method including: embedding a cooling channel interconnect circuit within a section of an outer wall of the component; and directing a flow of cooling fluid into the cooling channel interconnect circuit only in response to a wall notch that exposes a portion of the cooling channel interconnect circuit.

[0010] Exemplary aspects of the present disclosure address the problems described herein and / or other problems not discussed. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] These and other features of the present disclosure will be more readily understood from the following detailed description of various aspects of the present disclosure in conjunction with the accompanying drawings that depict various embodiments of the present disclosure.

[0012] Figure 1 A schematic diagram of a gas turbine system according to an embodiment is depicted.

[0013] Figure 2 A side view of a portion of a turbine section of a gas turbine system according to an embodiment is depicted.

[0014] Figure 3 A perspective view of a turbine blade according to an embodiment is depicted.

[0015] Figure 4A and Figure 4B Examples of impingement cooling before and after the formation of a wall notch are depicted, respectively.

[0016] Figure 5 An independent cooling circuit within a component of a gas turbine system as viewed from the inside out of the component according to an embodiment is depicted.

[0017] Figure 6 Depicted is an independent cooling circuit as viewed from the outside in of Figure 5 according to an embodiment.

[0018] Figure 7 Depicted is according to an embodimentFigure 6 An independent cooling circuit, where a portion of the outer wall is removed to show the cooling channel interconnecting circuit.

[0019] Figure 8 Depicts an independent cooling circuit according to an embodiment Figure 5 Another view of the independent cooling circuit, where a portion of the outer wall of the component is removed.

[0020] Figure 9 Depicts an independent cooling circuit according to an embodiment Figure 5 Cross-sectional view of the independent cooling circuit.

[0021] Figure 10 Depicts the operation of an independent cooling circuit according to an embodiment after partial or complete outer wall notch formation Figure 5 of the independent cooling circuit.

[0022] Figure 11 Depicts an independent cooling circuit in a component of a gas turbine system according to an additional embodiment.

[0023] Figure 12 Depicts an independent cooling circuit according to an additional embodiment Figure 11 where a portion of the outer wall of the component is removed.

[0024] Figure 13 Depicts an independent cooling circuit according to an additional embodiment Figure 11 Another view of the independent cooling circuit.

[0025] Figure 14 Depicts an independent cooling circuit in a component of a gas turbine system according to yet another embodiment.

[0026] Figure 15 Depicts an independent cooling circuit according to yet another embodiment Figure 14 Another view of the independent cooling circuit.

[0027] Figure 16 Depicts a block diagram of an additive manufacturing process according to an embodiment, the additive manufacturing process including a non-transitory computer-readable storage medium storing code representative of an object.

[0028] Figure 17 and Figure 18 Depicts a wall specimen block for additive manufacturing of a component for a gas turbine system according to an embodiment.

[0029] Figure 19 and Figure 20 Depicts a wall specimen block for additive manufacturing having powder removal openings according to an embodiment.

[0030] It should be noted that the accompanying drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the present disclosure and should not, therefore, be regarded as limiting the scope of the present disclosure. In the drawings, like numerals represent like elements among the drawings. Detailed Description

[0031] Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following description is not intended to limit the embodiments to one preferred embodiment. Instead, it is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the described embodiments as defined by the appended claims.

[0032] First, in order to clearly describe the present disclosure, it will be necessary to select certain terms when referring to and describing relevant machine components within the scope of the present disclosure. In doing so, where possible, common industry terms will be used and adopted in a manner consistent with their accepted meanings. Unless otherwise indicated, such terms should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. Those of ordinary skill in the art will appreciate that several different or overlapping terms may typically be used to refer to a particular component. An object that may be described herein as a single part may include multiple components and be referred to in another context as being composed of multiple components. Alternatively, an object that may be described herein as including multiple components may elsewhere be referred to as a single part.

[0033] In addition, several descriptive terms may be regularly used herein, and it should prove helpful to define these terms at the beginning of this section. Unless otherwise indicated, these terms and their definitions are as follows. As used herein, "downstream" and "upstream" are terms indicating direction relative to the direction of fluid flow, such as the working fluid through a turbine engine, or for example, the airflow through a burner or the coolant through one of the component systems of a turbine. The term "downstream" corresponds to the direction of fluid flow, and the term "upstream" refers to the direction opposite to the flow. In the absence of any additional particularity, the terms "front" and "rear" refer to directions, where "front" refers to the front end or compressor end of the engine, and "rear" refers to the rear end or turbine end of the engine. Additionally, the terms "forward" and "backward" may be used and / or understood separately and / or descriptively similar to the terms "front" and "rear". Generally, it is necessary to describe parts in different radial, axial, and / or circumferential positions. The "A" axis represents an axial orientation. As used herein, the terms "axial" and / or "axially" refer to the relative position / direction of an object along the axis A, which is substantially parallel to the rotational axis of the gas turbine system (particularly the rotor section). As further used herein, the terms "radial" and / or "radially" refer to the relative position / direction of an object along the direction "R" (see Figure 1), this direction is substantially perpendicular to axis A and intersects axis A at only one location. Finally, the term "circumferential" refers to movement or position around axis A (e.g., direction "C").

[0034] In various embodiments, components described as being "fluidly coupled" or "in fluid communication" with each other may be joined along one or more interfaces. In some embodiments, these interfaces may include joints between different components, and in other cases, these interfaces may include rigid and / or integrally formed interconnects. That is, in some cases, components that are "coupled" to each other may be formed simultaneously to define a single continuous member. However, in other embodiments, these coupled components may be formed as separate members and subsequently joined by known processes (e.g., fastening, ultrasonic welding, bonding).

[0035] Where an element or layer is referred to as being "on another element", "joined to another element", "connected to another element", or "coupled to another element", it may be directly on, joined to, connected to, or coupled to the other element, or intervening elements may be present. In contrast, where an element is referred to as being "directly on another element", "directly joined to another element", "directly connected to another element", or "directly coupled to another element", no intervening element or layer may be present. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between", "adjacent" versus "directly adjacent", etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0036] Figure 1 A schematic view of a gas turbine system 10 according to various embodiments is shown. As shown, the gas turbine system 10 includes a compressor section 12 that compresses an incoming air flow 14 and delivers a compressed air flow 16 to a combustor section 18. The combustor section 18 mixes the compressed air flow 16 with a pressurized fuel supply 20 and ignites the mixture to form a combustion gas flow 22. Although only a single combustor section 18 is shown, the gas turbine system 10 may include any number of combustor sections 18. The combustion gas flow 22 is then delivered to a turbine section 24. The combustion gas flow 22 drives the turbine section 24 to produce mechanical work. The mechanical work generated in the turbine section 24 drives the compressor section 12 via a shaft 26 and may be used to drive an external load 28 (such as a generator, etc.).

[0037] Figure 2A side view of a portion of a turbine section 24 of a gas turbine system is depicted, including at least one stage 30 of turbine blades 32 (one shown) and at least one stage 34 of nozzles 36 (one shown) located within a casing 38 of the turbine section 24. Each stage 30 of turbine blades 32 includes a plurality of turbine blades 32 coupled to and positioned circumferentially about the rotor 26 and driven by the combustion gases 22. Each stage 34 of nozzles 36 includes a plurality of nozzles 36 coupled to and positioned circumferentially about the casing 38 of the turbine section 24. Figure 2 In the illustrated embodiment, each nozzle 36 includes an airfoil 40 positioned between an outer platform 42 and an inner platform 44 .

[0038] Similar to the nozzle 36, each turbine blade 32 of the turbine section 24 includes an airfoil 46 extending radially from the rotor 26. Each airfoil 46 includes a tip portion 48 and a platform 50 positioned opposite the tip portion 48.

[0039] The turbine blades 32 and the nozzles 36 may be positioned axially adjacent to each other within the casing 38. Figure 2 , for example, nozzles 36 are shown as being axially positioned adjacent and downstream of turbine blades 32. Turbine section 24 may include a plurality of stages 30 of turbine blades 32 and a plurality of stages 34 of nozzles 36 positioned axially throughout a casing 38.

[0040] The turbine section 24 of the gas turbine system 10 may include a plurality of stages 52 of shrouds 54 positioned axially throughout the casing 38 (in Figure 2 One level is shown in Figure 2 , for example, the stage 52 of the shroud 54 is shown as being radially positioned adjacent to and substantially surrounding or encircling the stage 30 of the turbine stage blade 32. The stage 52 of the shroud 54 may also be axially positioned adjacent to and / or upstream of the stage 34 of the nozzle 36. In addition, the stage 52 of the shroud 54 may be positioned between two adjacent stages 34 of the nozzle 36 located on opposite sides of the stage 30 of the turbine blade 32. The stage 52 of the shroud 54 may be coupled around the casing 38 of the turbine section 24 using a set of extensions 56, each extension including an opening 58 configured to receive a corresponding section of the shroud 54.

[0041] Go to Figure 3, shows a perspective view of a turbine blade 32. The turbine blade 32 includes a shank 60; a platform 50 that is radially located above the platform 50; and an airfoil 46 that is coupled to the platform 50 and extends radially outward from the platform. The airfoil 46 includes a pressure side 62, an opposite suction side 64, and a tip portion 48. The airfoil 46 further includes a leading edge 68 that is between the pressure side 62 and the suction side 64; and a trailing edge 70 that is between the pressure side 62 and the suction side 64, on a side opposite the leading edge 68.

[0042] Many components of a gas turbine system (e.g., turbine blades, nozzles, shrouds, etc.) can be cooled during operation by guiding a fixed cooling fluid supply source through internal channels formed in these components. In many cases, the cooling fluid is provided by bleeding a fixed air supply source discharged by the compressor section of the gas turbine system.

[0043] Many different internal cooling methods can be used to cool the components of a gas turbine system, including, for example, convective cooling, film cooling, and impingement cooling. Convective cooling works by flowing the cooling fluid through channels inside the component. Heat is transferred through the component by conduction and then to the cooling fluid flowing through the component. With respect to film cooling, the cooling fluid is discharged through small holes formed through the outer wall of the component to the outer surface of the component. The cooling fluid provides a thin, cooled insulating blanket along the outer surface of the component. Impingement cooling (a variant of convective cooling) works by guiding a higher velocity flow of cooling fluid against the inner surface of the component. This allows more heat to be transferred by convection than conventional convective cooling. Impingement cooling is typically used in areas of the component that are exposed to high heat loads (e.g., the leading edge of a turbine blade).

[0044] If a notch is formed in a portion of a component of a gas turbine system (e.g., due to TBC spallation or other damage) and any internal cooling channels are exposed, some of the fixed cooling fluid supply source in the fixed cooling fluid supply source can flow out of the component through the notch from the exposed internal cooling channels. This reduces the remaining amount of the fixed cooling fluid supply source available for the component, thereby reducing the cooling effectiveness and potentially leading to component failure. Figure 4A and Figure 4B Examples of such wall notches are depicted in

[0045] Figure 4A Examples of impingement cooling in a component 80 of a gas turbine system (e.g., gas turbine system 10, Figure 1 ) are depicted. As shown, a cooling fluid supply source 82 is guided through a plurality of openings 88 formed in an impingement plate 90 against the inner surface 84 of the outer wall 86 of the component 80. The outer surface 92 of the outer wall 86 of the component 80 is exposed to a hot gas stream 94. Figure 4BDepicts a component 80 having a notch 96 extending through an outer wall 86. As shown, a portion of the cooling fluid 82 passes through the notch 96 and escapes past the outer wall 86 of the component 80, reducing the available cooling for the component 80, thereby causing damage propagation and potentially leading to component failure.

[0046] According to an embodiment, an independent cooling circuit is provided to deliver an additional independent cooling fluid supply source to a component of a gas turbine system in response to a partial or complete wall notch. The component can include, for example, a turbine blade, a nozzle airfoil, a shroud segment, a combustion liner, or other components that may require cooling during operation of the gas turbine system. Cooling channel interconnect circuits are embedded within the outer wall of the component. A plurality of coolant feed channels are disposed within the component (e.g., within / on an impingement plate or insert, within / on an inner wall, and / or the like). A plurality of feed tubes fluidly couple the coolant feed channels to the cooling channel interconnect circuits embedded within the outer wall of the component. During normal operation (e.g., no partial or complete notch in the outer wall of the component), the cooling fluid does not flow through the independent cooling circuit because there is no outlet for the cooling fluid. However, when a partial or complete wall notch occurs and exposes at least a portion of the cooling channel interconnect circuits embedded within the outer wall of the component, a flow path is created that allows the cooling fluid supply source to flow through the coolant feed channels, the feed tubes, and the cooling channel interconnect circuits to the affected area. The cooling provided by the additional independent cooling fluid flow can extend the life of the component after surface damage has occurred (e.g., reduce / prevent additional spalling in the notch area) without affecting the baseline cooling effectiveness within the component (e.g., impingement cooling).

[0047] A first embodiment of an independent cooling circuit 100 for a component 102 of a gas turbine system 10 according to an embodiment ( Figure 1 ) is shown in Figures 5 to 10 . The component 102 can include any component of the gas turbine system 10 that may require cooling, including but not limited to turbine blades, nozzle airfoils, shroud segments, combustion liners, etc. In this example, an impingement cooling arrangement 104 is used to cool the outer wall 106 of the component 102. For example, to provide impingement cooling, a supply source of cooling fluid 108 can be directed into the inner cavity 110 of the component 102 during operation of the gas turbine system 10. The supply source of cooling fluid 108 can be, for example, bled from a compressor section 12 of the gas turbine system 10 ( Figure 1) is provided by the discharged air. The cooling fluid 108 flows from the inner cavity 110 through a plurality of impingement holes 112 formed in the impingement plate 114, enters the impingement cavity 118, and impinges against the inner surface 116 of the outer wall 106 of the component 102. After impinging against the inner surface 116 of the outer wall 106, the cooling fluid 108 can be directed from the impingement cavity 118 to one or more internal / external regions of the component 102 (e.g., for film cooling). Although described in conjunction with impingement cooling in this and other embodiments, the independent cooling circuit 100 can be used in conjunction with other cooling arrangements (e.g., convective cooling, etc.).

[0048] Figures 5 to 10 (simultaneously mentioned) The independent cooling circuit 100 depicted includes a single pressurized supply source of the cooling fluid 128; a plurality of coolant feed channels 120 (although not always required depending on the application); a plurality of feed pipes 122 that connect the impingement plate 114 to the outer wall 106; and an interconnected circuit 124 of cooling channels 126 ( Figures 7 to 10 ) that is embedded within the outer wall 106 of the component 102. The interconnected circuit 124 of cooling channels 126 is fully encapsulated within the outer wall 106 of the component 102 such that none of the cooling channels 126 extends to or is exposed at the outer surface 132 (e.g., the hot gas surface) of the outer wall 106. The coolant feed channels 120 can be attached to the impingement plate 114, formed as a part of or within the impingement plate 114, or provided in any other suitable manner. According to an embodiment, the nominal position of the feed pipes 122 can be intermediate between the intersection points 130 to ensure feeding at the notches that are most likely to occur at the intersection points 130. In other embodiments, the feed pipes 122 can be located at or near the intersection points 130.

[0049] Each of these coolant feed channels 120 is fluidly coupled via a plurality of openings 121 in the impingement plate 114 and a plurality of feed tubes 122 to an interconnecting loop 124 of the cooling channels 126. The coolant feed channels 120 are each fluidly coupled to a pressurized source of coolant 128 that is independent of the source of coolant 108 provided to the impingement cooling arrangement 104. The source of coolant 128 can be provided by bleeding off a source of air discharged by the compressor section 12 of the gas turbine system 10 or in any other suitable manner (e.g., a source of compressed air provided by a source other than the compressor section 12 of the gas turbine system 10). The interconnecting loop 124 of the cooling channels 126 does not include an outlet for the coolant 128. If desired, the coolant feed channels 120 can also include individual channels that feed each of the feed tubes 122. In other embodiments, the coolant feed channels 120 can be integral with the outer wall 106. In embodiments where the coolant feed channels 120 are not used, the pre-impingement coolant 108 can be fed through the plurality of feed tubes 122 into the interconnecting loop 124 of the cooling channels 126.

[0050] In Figures 5 to 10 In the illustrated embodiment, the cooling channels 126 of the interconnecting loop 124 can be embedded within the outer wall 106 of the component 102 at a distance that is substantially the same as the outer surface 132 of the outer wall 106 (e.g., in a planar configuration). Additionally, the feed tubes 122 can extend into the outer wall 106 for a distance that is substantially the same as the cooling channels 126 of the interconnecting loop 124. A plurality of intersections 130 can be provided to fluidly interconnect all of the cooling channels 126 of the interconnecting loop 124. The cooling channels 126 can be arranged in a grid-like pattern (e.g., a rectangular grid) within the outer wall 106 and can extend linearly between the feed tubes 122 and / or between the intersections 130.

[0051] In other embodiments, as will be described in more detail below, the cooling channels 126 (or portions thereof) of the interconnecting loop 124 can be embedded within the outer wall 106 at different distances from the outer surface 132 of the outer wall 106. This may require the feed tubes 122 to extend into the outer wall 106 for different distances from the cooling channels 126 of the interconnecting loop 124.

[0052] During normal operation (e.g., in the absence of a partial or complete notch in the outer wall 106 of the component 102), no flow of coolant 128 passes through the independent cooling loop 100 because the interconnecting loop 124 of the cooling channels 126 is embedded and fully encapsulated within the outer wall 106 and does not include an outlet for the coolant 128. However, as Figure 10As shown, in response to the formation of a partial or full-wall notch 96 in the outer wall 106 of component 102, at least a portion of the cooling channels 126 in the outer wall 106 of component 102 may become exposed, thereby providing an outlet for the cooling fluid 128. To this extent, the cooling fluid 128 can now flow through the cooling channels 126 exposed by the wall notch 96. Specifically, the cooling fluid 128 can flow through the coolant feed channels 120, the plurality of feed tubes 122, and the cooling channels 126 of the interconnecting loop 124 to and from the cooling channels 126 exposed by the wall notch 96. The cooling fluid 128 ultimately flows out of the cooling channels 126 exposed in the notch 96 to the exterior of component 102. Generally, the flow rate of the cooling fluid 128 increases in the cooling channels 126 closest to the notch 96. The flow of the cooling fluid 128 provides additional cooling to component 102 in the region adjacent to the wall notch 96, which is independent of any cooling provided by the impingement cooling arrangement 104. The additional cooling provided by the cooling fluid 128 can, for example, reduce or prevent additional spalling in the region of the notch 96. This can prevent the notch 96 from increasing in size and can extend the operating life of component 102.

[0053] The independent cooling system 100 includes a plurality of coolant feed channels 120 and a plurality of feed tubes 122. In addition, the cooling channels 126 are interconnected by a plurality of intersections 130. Figures 11 to 13 (Mentioned simultaneously) shows another embodiment of an independent cooling loop 200 that includes a plurality of feed channels, a plurality of feed tubes, and a plurality of cooling channels interconnected by a plurality of intersections.

[0054] As in Figures 5 to 10 the embodiment shown, an impingement cooling system 104 is provided to cool the outer wall 106 of component 102. To provide impingement cooling, a source of the cooling fluid 108 is directed into the inner cavity 110 of component 102 during operation of the gas turbine system 10 (see, for example, Figure 5 ). The cooling fluid 108 flows from the inner cavity 110 through a plurality of impingement holes 112 (formed, for example, in the impingement plate 114), into the impingement cavity 118, and against the inner surface 116 of the outer wall 106 of component 102.

[0055] The independent cooling loop 200 may include a plurality of coolant feed channels 120 (see, for example, Figure 5)(although not always required depending on the application); a plurality of feed tubes 202 that connect the impact plate 114 to the outer wall 106; and an interconnecting circuit 204 of cooling channels 206 that is embedded within the outer wall 106 of the component 102. The interconnecting circuit 204 of cooling channels 206 is fully encapsulated within the outer wall 106 of the component 102 such that none of the cooling channels 206 extend to or are exposed at the outer surface 132 of the outer wall 106 of the component 102. A plurality of intersections 208 are provided to fluidly couple all of the cooling channels 206. The interconnecting circuit 204 of cooling channels 206 does not include an outlet for the cooling fluid 128. The cooling channels 206 may be arranged in a grid pattern (e.g., a rectangular grid) within the outer wall 106.

[0056] Different from the interconnecting circuit 124 of cooling channels 126 that linearly extends between the feed tubes 122 and / or between the intersections 130 as described above with respect to Figures 5 to 10 , some or all of the cooling channels 206 in the interconnecting circuit 204 of the independent cooling circuit 200 may have a non-linear configuration (e.g., a zigzag configuration, a sinusoidal configuration, etc. as shown). As Figures 11 to 13 depicted, for example, the cooling channels 206 may be zigzag within the outer wall 106 between the feed tubes 202 and / or between the intersections 208. Accordingly, the distance between the cooling channels 206 and the outer surface 132 of the outer wall 106 may vary.

[0057] During normal operation (e.g., in the absence of a partial or complete notch 96 in the outer wall 106 (see, e.g., Figure 10 )), there is no flow of the cooling fluid 128 through the independent cooling circuit 200 because the interconnecting circuit 204 of the cooling channels 206 is embedded and fully encapsulated within the outer wall 106 of the component 102 and does not include an outlet for the cooling fluid 128. When a partial or complete wall notch 96 occurs in the outer wall 106, at least a portion of the cooling channels 206 in the outer wall 106 of the component 102 may become exposed, thereby providing an outlet for the cooling fluid 128. Accordingly, the cooling fluid 128 can now flow through the coolant feed channel 120 ( Figure 5 ), the plurality of openings 201 in the impact plate 114, the plurality of feed tubes 202, and the cooling channels 206 of the interconnecting circuit 204, and then out of the cooling channels 206 exposed by the wall notch 96. This flow of the cooling fluid 128 provides additional cooling of the component 102 in the region adjacent to the wall notch 96, which is independent of any cooling provided by the impingement cooling arrangement 104. In an embodiment where the cooling feed channel 120 is not used, the pre-impingement cooling fluid 108 may be fed through the plurality of feed tubes 122 into the interconnecting circuit 204 of the cooling channels 206.

[0058] Advantageously, the longer flow path of the cooling fluid 128 due to the non-linear configuration of the interconnecting loop 204 of the cooling channels 206 can enhance heat transfer to the cooling fluid 128 and enhance the cooling effectiveness of the independent cooling loop 200. Additionally, in response to the formation of a shallower / smaller notch 96, portions of the cooling channels 206 positioned closer to the outer surface 132 of the outer wall 106 of the component 102 can become exposed. Thus, the independent cooling loop 200 can be activated in response to a spallation event more quickly than the independent cooling loop 100 having a planar configuration. Further, the additional cooling provided by the cooling fluid 128 can reduce additional spallation or prevent additional spallation from occurring, for example, in the region of the notch 96. This can prevent the notch 96 from increasing in size and can extend the operating life of the component 102.

[0059] An independent cooling loop 300 in accordance with yet another embodiment is depicted in Figure 14 and Figure 15 . Again, as in the above-described embodiments, the independent cooling loop 300 includes a plurality of feed channels; a plurality of feed tubes that connect the impingement plate 114 to the outer wall 106; and a plurality of cooling channels that are interconnected by a plurality of intersections.

[0060] As in other embodiments, an impingement cooling system 104 is provided to cool the outer wall 106 of the component 102. To provide impingement cooling, a source of the cooling fluid 108 is directed into the inner cavity 110 of the component 102 during operation of the gas turbine system 10 (see, for example, Figure 5 ). The cooling fluid 108 flows from the inner cavity 110 through a plurality of impingement holes 112 (formed, for example, in the impingement plate 114), into the impingement cavity 118, and against the inner surface 116 of the outer wall 106 of the component 102.

[0061] The independent cooling loop 300 includes a plurality of feed tubes 302 that connect the impingement plate 114 to the outer wall 106; and an interconnecting loop 304 of the cooling channels 306, 308. The feed tubes 302 are fluidly coupled to the coolant feed channel 120 ( Figure 5 ), although not always required depending on the application). The cooling channels 306 are arranged in a grid pattern (e.g., a rectangular grid) and extend between intersections 310 that are fluidly coupled to the feed tubes 202. The cooling channels 308 extend diagonally between adjacent intersections 310. Pairs of intersections of the cooling channels 308 can be fluidly coupled together at intersections 312. The interconnecting loop 304 of the cooling channels 306, 308 does not include an outlet for the cooling fluid 128. In embodiments where the cooling feed channel 120 is not used, the pre-impingement cooling fluid 108 can be fed through a plurality of feed tubes 122 into the interconnecting loop 304 of the cooling channels 306.

[0062] Some or all of the cooling channels 306, 308 in the interconnecting circuit 304 of the independent cooling circuit 300 may have a non-linear configuration (e.g., a zigzag configuration, a sinusoidal configuration, etc. as shown). As Figure 14 and Figure 15 shown, for example, the cooling channels 306, 308 may be zigzag within the outer wall 106 between the intersections 310 and between the intersections 312, respectively. Such non-linear configurations provide a longer flow path within the outer wall 106, which can enhance heat transfer to the cooling fluid 128 and enhance the cooling effectiveness of the independent cooling circuit 300. The use of the diagonally extending cooling channel 308 can also enhance heat transfer to the cooling fluid 128.

[0063] Comparing Figure 15 with Figure 8 or Figure 13 , it can be seen that due to the incorporation of the diagonally extending cooling channel 308, the interconnecting circuit 304 can also provide a higher density of cooling channels 306, 308 than the interconnecting circuits 104, 204. To this extent, in response to the formation of a smaller wall notch 96, the cooling channels 306, 308 in the interconnecting circuit 304 may be more likely to be exposed. In addition, the higher density of cooling channels 306, 308 can enhance heat transfer to the cooling fluid 128 and enhance the cooling effectiveness of the independent cooling circuit 300. Additionally, portions of the cooling channels 306, 308 positioned closer to the outer surface 132 of the outer wall 106 of the component 102 can become exposed in response to the formation of a shallower / smaller notch 96, resulting in earlier activation of the independent cooling circuit 300 (e.g., compared to the independent cooling circuit 100).

[0064] During normal operation (e.g., in the absence of a partial or complete notch 96 in the outer wall 106 of the component 102 (see, for example, Figure 10 )), no cooling fluid 128 flows through the independent cooling circuit 300 because the interconnecting circuit 304 of the cooling channels 306, 308 is embedded and completely encapsulated within the outer wall 106 and does not include an outlet for the cooling fluid 128. When a partial or complete wall notch 96 occurs in the outer wall 106, at least a portion of the cooling channels 306 and / or 308 in the outer wall 106 of the component 102 can become exposed, providing an outlet for the cooling fluid 128. Thus, the cooling fluid 128 can now flow (and flow out) through the coolant feed channel 120, the plurality of feed tubes 302, and the cooling channels 306, 308 of the interconnecting circuit 304 to the cooling channels 306, 308 exposed at the wall notch 96.

[0065] Cooling fluid 128 flows through an independent cooling circuit 300 to provide additional cooling of component 102 in the region adjacent to wall notch 96, independent of any cooling provided by impingement cooling arrangement 104. The additional cooling provided by cooling fluid 128 can, for example, reduce or prevent additional spalling in the region of notch 96. This can prevent the size of notch 96 from increasing and can extend the operating life of component 102.

[0066] The various components and features of the independent cooling circuits 100, 200, 300 of the present disclosure can be formed using additive manufacturing processes. Advantageously, additive manufacturing enables the design and production of more customizable and complex feature structures.

[0067] As used herein, additive manufacturing can include any process for producing an object by successively layering material rather than removing material (as is the case with conventional processes). Additive manufacturing can form complex geometries without the use of any kind of tool, die, or fixture, and with little or no waste of material. Instead of machining a component from a solid plastic or metal blank (much of which is cut away and discarded), the only material used in additive manufacturing is that which is required to form the part. Additive manufacturing processes can include, but are not limited to: 3D printing, rapid prototyping (RP), direct digital manufacturing (DDM), binder jetting, selective laser melting (SLM), and direct metal laser melting (DMLM). In the current setup, DMLM or SLM has been found to be advantageous.

[0068] For purposes of illustrating an example of an additive manufacturing process, Figure 16 a schematic / block diagram of an exemplary computerized additive manufacturing system 400 for generating an object 402 is shown. In this example, the system 400 is arranged for DMLM, but it should be understood that the general teachings of the present disclosure apply equally to other forms of additive manufacturing. AM system 400 generally includes a computerized additive manufacturing (AM) control system 404 and an AM printer 406. AM system 400 executes code 420, which includes a set of computer-executable instructions that define object 402, to physically generate object 402 using AM printer 406. Each AM process can use a different raw material in the form of, for example, fine-grained powder, liquid (such as a polymer), sheet, etc., the stock of which can be held in chamber 410 of AM printer 406. According to an embodiment, object 402 can be made of a material capable of withstanding the gas turbine system 10 (see Figure 1) made of metal or metal compound in the environment. As shown, the applicator 412 can form a thin layer of the raw material 414, which spreads out as a blank canvas on the build plate 444 of the AM printer 406, and each successive slice of the final object will be formed based on this blank canvas. In other cases, the applicator 412 can directly apply or print the next layer onto the previous layer defined by the code 420. In the example shown, as defined by the code 420, a laser or electron beam fuses the particles of each slice. Various parts of the AM printer 406 can be moved to accommodate the addition of each new layer. For example, after each layer, the build platform 418 can be lowered, and / or the chamber 410 and / or the applicator 412 can be raised.

[0069] The AM control system 404 is shown as being implemented as computer program code on the computer 430. To that extent, the computer 430 is shown to include a memory 432, a processor 434, an input / output (I / O) interface 436, and a bus 438. Additionally, the computer 430 is shown to communicate with external I / O devices / resources 440 and a storage system 442. Generally, the processor 434 executes the computer program code stored in the memory 432 and / or the storage system 442, such as the AM control system 404, under the instructions from the code 420 representing the object 402.

[0070] The additive manufacturing process begins with a non-transitory computer-readable storage medium (e.g., the memory 432, the storage system 442, etc.) that stores the code 420 representing the object 402. For example, the code 420 can include an accurately defined 3D model of the object 402 and can be generated by any of a variety of well-known computer-aided design (CAD) software systems. The AM control system 404 executes the code 420, dividing the object 402 into a series of thin slices to be assembled using the AM printer 406 in successive liquid, powder, sheet, or other material layers.

[0071] An additive manufacturing (AM) process (e.g., using the AM system 400, Figure 16 ) can be used to produce various components of the gas turbine system 10 ( Figure 1 ) or portions of such components. For example, at least a portion of the outer wall of a component including a cooling channel interconnect loop can be produced via the AM process.

[0072] In Figure 17 , for example, (e.g., printed) has been produced via the AM process Figures 5 to 10The wall specimen block 500 of component 102 depicted in

[0073] According to an embodiment, the wall specimen block 500 can be produced in any size via an AM process and can be attached to another section 504 of component 102 to form at least a part of the independent cooling circuit 100 (see, for example, Figure 18 ). The section 504 of component 102 can be formed in a conventional manner (e.g., machining, casting, etc.) or can be formed using an AM process. It should be noted that the wall specimen 500 can be configured for any of the independent cooling circuits 100, 200, 300 described herein. The attachment can be achieved, for example, using brazing, fusion welding, or other suitable metal joining processes. Figure 18 Depicted is the wall specimen 500 attached (e.g., via brazing / fusion welding) to the impact plate 114 of component 102 to form at least a part of the independent cooling circuit 100. In other embodiments, Figure 18 the entire cooling structure depicted in

[0074] The independent cooling circuit 100 formed using an AM printed wall specimen block 500 can be strategically placed in those areas of component 102 of the gas turbine system 10 that are likely to suffer from spalling. This can be done, for example, without having to produce the entire component 102 using an AM process. Additionally, the independent cooling circuit 100 formed using an AM printed wall specimen block 500 can be retrofitted into an existing component 102 of the gas turbine system 10 to repair areas previously damaged by spalling and / or selectively provide enhanced cooling to areas of component 102 that are subject to spalling as described above.

[0075] When producing the independent cooling circuits 100, 200, 300 (or parts thereof) using an AM process, the removal of excess powder can be problematic. Since the independent cooling circuits 100, 200, 300 do not have an outlet for the cooling fluid 128 (e.g., the circuits are deliberately closed-ended), there is no easy way to use forced air to attempt to remove the excess powder.

[0076] According to an embodiment, as Figure 19 and Figure 20 depicted in Figure 17 andFigure 18 ) As described, a plurality of small openings 600 for powder removal (e.g., formed during the AM process) can be provided in the outer wall section 502 of the wall specimen block 500. In Figure 19 and Figure 20 , for example, the openings 600 are shown extending from the interconnecting circuit 124 of the cooling channels 126 of the independent cooling circuit 100 through the outer wall section 502 to the outer surface 132 of the wall specimen block 500.

[0077] The openings 600 provide an outlet for removing excess powder. The powder can be removed, for example, using vibration or by forcing air into the interconnecting circuit 124 of the cooling channels 126 and out through the openings 600. After powder removal, the openings 600 can be filled / sealed in any suitable manner (e.g., filled with metal, sealant, etc.) to close the independent cooling circuit 100. The openings 600 can be filled / sealed before applying the TBC coating on the outer surface 132 of the wall specimen block 500, or simply sealed by the TBC coating itself. In some cases, before any interconnecting circuit in the interconnecting circuit 124 of the cooling channels 126 is exposed due to the formation of a notch, a spalling event may unseal some of the sealed openings 600. Then, the cooling fluid 128 can flow to and from the unsealed openings 600 via the independent cooling circuit 100, thereby providing immediate cooling benefits.

[0078] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It will be further understood that when used in the specification, the terms "comprises" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0079] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system and performing any combined methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If such other examples have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims, then such other examples are intended to be within the scope of the claims.

Claims

1. An independent cooling circuit for selectively delivering a cooling fluid, the independent cooling circuit comprising: An interconnected circuit of cooling channels embedded within an outer wall of a component of a gas turbine system; An impingement plate; And A plurality of feed tubes connecting the impingement plate to the outer wall of the component and fluidly coupling a source of cooling fluid to the interconnected circuit of cooling channels; Wherein the cooling fluid flows through the plurality of feed tubes into the interconnected circuit of cooling channels only in response to the formation of a notch in the outer wall of the component exposing at least one of the cooling channels.

2. The independent cooling circuit according to claim 1, wherein, The cooling fluid flows through the interconnected circuit of cooling channels towards the notch in response to the exposure of at least one of the cooling channels.

3. The independent cooling circuit according to claim 1, wherein, The cooling channels are arranged in a grid within the outer wall of the component, the grid comprising a plurality of intersections.

4. The independent cooling circuit according to claim 3, wherein, At least some of the cooling channels extend between diagonally adjacent pairs of the plurality of intersections.

5. The independent cooling circuit according to claim 3, wherein, At least some of the cooling channels extend linearly between the plurality of intersections.

6. The independent cooling circuit according to claim 5, wherein, The cooling channels are located at the same distance from an outer surface of the outer wall of the component.

7. The independent cooling circuit according to claim 3, wherein, At least some of the cooling channels extend non-linearly between the plurality of intersections.

8. The independent cooling circuit according to claim 7, wherein, The distance between the cooling channels and the outer surface of the outer wall of the component varies.

9. The independent cooling circuit according to claim 1, the independent cooling circuit further comprising at least one coolant feed channel fluidly coupling the source of cooling fluid to the plurality of feed tubes.

10. The independent cooling circuit according to claim 1, the independent cooling circuit further comprising a wall specimen formed using an additive manufacturing process, the wall specimen comprising a section of the outer wall of the component and the plurality of feed tubes, wherein the interconnected circuit of cooling channels is embedded within the section of the outer wall.

11. The independent cooling circuit according to claim 10, wherein, The wall specimen is attached to the impingement plate.

12. The independent cooling circuit according to claim 10, wherein, The wall specimen includes a plurality of powder removal openings extending from the interconnected circuit of cooling channels to an outer surface of the section of the outer wall.

13. A cooling system comprising: A component of a gas turbine system; And An independent cooling circuit for selectively delivering a cooling fluid to the component of the gas turbine system, the independent cooling circuit comprising: An interconnected circuit of cooling channels embedded within an outer wall of the component; An impingement plate; and A plurality of feed tubes connecting the impingement plate to the outer wall of the component and fluidly coupling a source of cooling fluid to the interconnected circuit of cooling channels; Wherein the cooling fluid flows through the plurality of feed tubes into the interconnected circuit of cooling channels only in response to the formation of a notch in the outer wall of the component exposing at least one of the cooling channels.

14. The cooling system according to claim 13, wherein, The cooling channels are arranged in a grid within the outer wall of the component, the grid including a plurality of intersection points, and wherein the cooling channels extend between the plurality of intersection points.

15. The cooling system according to claim 14, wherein, At least some of the cooling channels extend between diagonally adjacent pairs of the plurality of intersection points.

16. The cooling system according to claim 14, wherein, At least some of the cooling channels extend linearly between the plurality of intersection points, and wherein the cooling channels are located at the same distance from the outer surface of the outer wall of the component.

17. The cooling system according to claim 14, wherein, At least some of the cooling channels extend non-linearly between the plurality of intersection points, and wherein the distance between the cooling channels and the outer surface of the outer wall of the component varies.

18. A method for reducing spallation-related damage, the method comprising: Embedding an interconnected loop of cooling channels within a section of the outer wall of a component of a gas turbine system; Connecting impingement plates to the outer wall of the component with a plurality of feed tubes; Fluidly coupling a source of cooling fluid to the interconnected loop of cooling channels via the plurality of feed tubes; and Directing a flow of cooling fluid through the plurality of feed tubes into the interconnected loop of cooling channels only in response to a wall breach exposing a portion of the interconnected loop of cooling channels.

19. The method of claim 18, the method further comprising: Forming the section of the outer wall including the interconnected loop of cooling channels using an additive manufacturing process; And Replacing a damaged section of the outer wall of the component with the section of the outer wall including the interconnected loop of cooling channels.

20. The method of claim 18, the method further comprising: Forming the section of the outer wall including the interconnected loop of cooling channels using an additive manufacturing process; And Attaching the section of the outer wall including the interconnected loop of cooling channels to a component area of the component subject to spallation.

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