Exhaust collector conversion system and method

Abstract

The present invention discloses a system that includes an exhaust collector tunnel (32) configured to be installed inside an exhaust collector (30) of a gas turbine (12). The exhaust collector tunnel (32) has a tunnel wall (33) configured to extend around turbine shafts (17, 19) of the gas turbine (12). The tunnel wall (33) has a variable diameter (98) along at least a portion of the length of the exhaust collector tunnel (32).

Description

BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates to turbine systems, and more particularly, to systems and methods for turbine systems having exhaust collectors.

[0002] Power plants, such as combined cycle power plants, typically include gas turbine engines. The gas turbine engine combusts fuel to generate hot combustion gases that flow through a turbine to drive a load, such as a generator. At high speeds and temperatures, the exhaust gases exit the turbine and enter an exhaust collector. Unfortunately, the exhaust collector is typically only usable with one type of turbine engine. SUMMARY OF THE INVENTION

[0003] Certain embodiments are outlined below that are equivalent in scope to the originally claimed subject matter. These embodiments are not intended to limit the scope of the claimed subject matter, but rather these embodiments are only intended to provide a brief overview of possible forms of the subject matter. Indeed, the subject matter may cover various forms that may be similar to or different from the embodiments set forth below.

[0004] In a first embodiment, a system includes an exhaust collector tunnel configured to be installed inside an exhaust collector of a gas turbine. The exhaust collector tunnel has a tunnel wall configured to extend around a turbine shaft of the gas turbine. The tunnel wall has a variable diameter along at least a portion of the length of the exhaust collector tunnel.

[0005] In a second embodiment, a system includes an exhaust collector configured to be coupled to a gas turbine. The exhaust collector includes an exhaust collector frame, an exhaust diffuser disposed in the exhaust collector frame, a diverging section disposed in the exhaust collector frame downstream of the exhaust diffuser, and an exhaust collector tunnel disposed in the exhaust collector frame between the exhaust diffuser and the diverging section. The exhaust collector tunnel has a tunnel wall configured to extend around a turbine shaft of the gas turbine. The tunnel wall has a variable diameter along at least a portion of the length of the exhaust collector tunnel.

[0006] In a third embodiment, a method includes installing an exhaust collector tunnel inside an exhaust collector of a gas turbine. The exhaust collector tunnel has a tunnel wall configured to extend around a turbine shaft of the gas turbine. The tunnel wall has a variable diameter along at least a portion of the length of the exhaust collector tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features, aspects, and advantages of the subject matter of the present invention will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout the drawings, where:

[0008] Figure 1Illustrations of embodiments of a gas turbine power station with an exhaust collector assembly that can be modified (e.g., retrofitted) with multiple different tunnels, diffusers, seals, and mounting brackets;

[0009] Figure 2 is Figure 1 A cross-sectional view of an embodiment of the exhaust collector assembly, showing a retrofit kit with a tunnel (e.g., a constant diameter tunnel) that can be used to retrofit the exhaust collector assembly;

[0010] Figure 3 is Figure 2 A partial cross-sectional view of the exhaust collector assembly, showing an embodiment of the turbine connection assembly;

[0011] Figure 4 is Figure 2 A partial cross-sectional view of the exhaust collector assembly, showing an embodiment of the diffuser connection assembly;

[0012] Figure 5 is Figure 1 A cross-sectional view of an embodiment of the exhaust collector assembly, showing a retrofit kit with a tunnel (e.g., a variable diameter tunnel) that can be used to retrofit the exhaust collector assembly;

[0013] Figure 6 is Figure 5 A partial cross-sectional view of the exhaust collector assembly, showing an embodiment of the turbine connection assembly;

[0014] Figure 7 is Figure 5 A partial cross-sectional view of the exhaust collector assembly, showing an embodiment of the diffuser connection assembly;

[0015] Figure 8 is Figure 1 A cross-sectional view of an embodiment of the exhaust collector assembly, showing a retrofit kit with a tunnel (e.g., a stepped tunnel) that can be used to retrofit the exhaust collector assembly;

[0016] Figure 9 is a flowchart of a method of removing multiple parts of the exhaust collector assembly in preparation for retrofitting with one of the retrofit kits of Figures 2 to 8 ; and

[0017] Figure 10 is for installing Figures 2 to 8 one of the retrofit kits of Figure 1 to modify the exhaust collector assembly of Detailed Description

[0018] One or more specific embodiments of the subject matter of the present invention will now be described. To provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be understood that such development work might be complex and time-consuming, but would still be a routine task of design, fabrication, and manufacture for those of ordinary skill in the art who have benefited from the present disclosure.

[0019] When introducing elements of the various embodiments of the subject matter of the present invention, the articles "a", "an", "the", and "said" are intended to mean that there is one or more of the elements. The terms "comprising", "including", and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0020] The embodiments disclosed herein include a retrofit kit for use with an exhaust collector of a gas turbine engine system. The retrofit kit includes one or more diffusers having different sizes and interfaces, a tunnel coupled to a diverging section (e.g., a conical section, a deflector section) of the exhaust collector, and a turbine frame implemented by a combination of a coupling structure (e.g., bolts, brackets) and one or more enlarged seal assemblies (e.g., circumferential grooves, circumferential seal segments, bolts, etc.). The tunnel may pass through a diffuser section of the gas turbine engine such that the tunnel is concentric with the diffuser section. That is, the tunnel (e.g., a bore) may be thermally insulated and coupled to an exhaust collector frame, extend into a collector chamber, pass through an exhaust diffuser, and be coupled to the gas turbine engine. The tunnel may surround a linkage (e.g., a shaft coupling of a gas turbine and a load shaft), thereby thermally insulating the linkage from hot gases. The tunnel may be a retrofit or an original component of the gas turbine engine. For example, the embodiments disclosed herein include a retrofit kit that includes an exhaust collector tunnel that enables a particular exhaust system (e.g., an exhaust collector) designed for a larger turbine engine to be used with a different turbine engine by changing the interface between the exhaust collector tunnel and a gas turbine frame for coupling the tunnel to the gas turbine engine.

[0021] The retrofit kit uses one or more seal carriers to reduce exhaust gas leakage. The tunnel has a geometry that is designed to transition from a gas turbine engine to a divergent section (e.g., a conical section, a deflector section) of an exhaust collector. For some embodiments of the gas turbine engine, the geometry of the tunnel can be cylindrical (e.g., a straight annular wall) from the gas turbine engine to the divergent section. However, for other embodiments of the gas turbine engine, the geometry of the tunnel can be variable (e.g., an annular wall with a variable diameter) from the gas turbine engine to the divergent section. For example, the annular wall of the tunnel can gradually increase or decrease from the gas turbine engine to the divergent section. The annular wall of the tunnel can have a frustoconical shape, a curved annular shape, a stepped annular shape (e.g., an annular wall with multiple stepped diameters), or a combination thereof. Thus, the retrofit kit enables an exhaust collector designed for a larger gas turbine engine to be used on other models of gas turbine engines (e.g., smaller engines), or vice versa, without the need for complex modifications to the exhaust collector housing or other packaging housings of the gas turbine engine power plant. For example, the retrofit kit can enable the tunnel to be directly installed between an existing exhaust collector and a gas turbine frame. Although a retrofit kit for a gas turbine engine is currently envisioned, the embodiments disclosed herein are not limited to retrofit kits.

[0022] Turning now to the drawings and first referring to Figure 1 , an illustration of a gas turbine engine power plant 10 is shown. A gas turbine engine 12 (or gas turbine), such as an aeroderivative gas turbine engine, is coupled to an exhaust collector assembly 14. The illustration also depicts a generator 16 coupled to the turbine engine 12 by a linkage 18 (e.g., a rotary coupling or a shaft coupling). The gas turbine engine 12, the exhaust collector assembly 14, and the generator 16 can be rigidly attached to a skid platform 20. Clean air for combustion can be supplied by an air intake and filtration system 22. The air is compressed in the compressor section of the gas turbine engine 12 and mixed with a liquid fuel or a gaseous fuel (such as natural gas). The fuel-air mixture then burns in the combustion chamber of the gas turbine engine 12. The hot pressurized gas generated by the combustion of the fuel-air mixture then passes through multiple turbine blades in the gas turbine engine 12. The hot pressurized gas will cause the turbine blades to rotate, thereby causing the rotation of the linkage 18. The rotation of the linkage 18 can drive a load, such as the generator 16, as shown.

[0023] In one embodiment, hot gases exit a gas turbine engine 12 in an axial direction and enter an exhaust collector assembly 14 downstream of the gas turbine engine 12. The gas turbine engine 12 converts a portion of the energy in the hot gases into rotational motion. However, some of the available energy may still remain in the hot exhaust gases. Thus, the exhaust collector assembly 14 can capture and direct the hot exhaust gases for further use, such as by a heat recovery steam generator (HRSG). The HRSG can use the hot exhaust gases to generate steam for use in a steam generator and / or other equipment in a power plant 10. The hot gases exiting into the exhaust collector assembly 14 can flow at high speeds and contain high temperatures. By using the embodiments described in more detail below with respect to Figures 2 to 10 the exhaust collector assembly 14 designed for a first gas turbine engine (e.g., a first power turbine) can be used with a second gas turbine engine (e.g., a second power turbine). The first gas turbine engine and the second gas turbine engine can differ in terms of turbine outlet or connection to the exhaust collector model, physical size, power output, and geometry. However, the embodiments disclosed herein address these differences by adapting or modifying the exhaust collector assembly 14 for use with any desired gas turbine engine.

[0024] Figure 2 A perspective view of an embodiment of an exhaust collector 30 of a gas turbine system 10 is shown, where the exhaust collector 30 is coupled to a tunnel 32 (e.g., an exhaust collector tunnel or shaft coupling tunnel). To clearly illustrate the features of the tunnel 32, the entire turbine 12, linkages 18, inlet, and filtration system 22 of the gas turbine system 10 are not shown in Figure 2 the drawing. Components of the gas turbine engine system 10, such as the exhaust collector 30, can be disposed in one or more frames 34. The exhaust collector 30 is coupled to a diffuser 36 that is located downstream of the turbine 12 relative to an inlet axis (i.e., turbine axis 38). The diffuser 36 is configured to be coupled to the outer wall of the turbine 12 (e.g., defining the outer boundary of the exhaust flow path), while the tunnel 32 is configured to be coupled to the inner wall of the turbine 12 (e.g., defining the inner boundary of the exhaust flow path).

[0025] The exhaust diffuser 36 shown has an annular wall 40 that increases in diameter in the downstream direction 42 of the exhaust gas flow from the gas turbine engine 12 toward the exhaust collector 30. The annular wall 40 can be described as a diverging or expanding annular wall that diverges away from the longitudinal axis 44 in the downstream direction 42 of the exhaust gas flow. The annular wall 40 can expand linearly (e.g., a frustoconical wall) and / or curvilinearly (e.g., a curved annular wall or a bell-shaped wall). The smaller diameter end 46 of the diffuser 36 is coupled to the gas turbine engine 12 (a portion is shown). The diffuser 36 diffuses the axial flow of the exhaust gas flowing out of the gas turbine engine 12 (e.g., spreads it out and reduces its velocity). The exhaust collector 30 receives the exhaust gas flow from the diffuser 36 into the collector chamber 37 along the inlet axis.

[0026] The exhaust collector 30 is disposed within an exhaust collector frame 34 (e.g., a housing) that includes a right wall 48, a top wall 50, a left wall 52, a bottom wall 54, a rear wall 56, and a front wall 58. A diverging section 60 (e.g., a diverging annular wall or a diverging wall) can project axially away from the left wall 52 and into the exhaust collector 30. The diverging section 60 can have a constant or substantially constant angle (e.g., a deflector section or a frustoconical wall) and / or a variable angle (e.g., a curved annular wall, such as a bell shape) relative to the longitudinal axis 44. For example, the angle can be about 20 degrees to 70 degrees, 30 degrees to 60 degrees, or 40 degrees to 50 degrees. The diverging section 60 can be used, for example, to radially disperse some of the gas flow such that the gas flow does not directly impact the left wall 52 in the same axial direction. As shown, the diverging section 60 diverges in the downstream direction 42 along the longitudinal axis 44, thereby gradually redirecting the exhaust gas flow from the axial direction 62 to the radial direction 64.

[0027] The tunnel 32 can be thermally insulated and coupled to the diverging section 60, extend into the exhaust collector 30, pass through the diffuser 36, and be coupled to the gas turbine engine 12 via the turbine frame 66 (see Figure 3 ). The thermally insulated tunnel 32 can include an annular wall 33 that has one or more walls or layers made of the same or different materials. For example, the annular wall 33 can include an inner annular wall 68, an outer annular wall 70, and one or more insulating layers 69 located between the inner annular wall 68 and the outer annular wall 70. The tunnel 32 can be coaxial with the longitudinal axis 42, e.g., generally at the axial center of the inner hollow region of the diffuser 36. The tunnel 32 can pass through a diffuser opening 72 at one end and be coupled to the turbine frame 66. The tunnel 32 can surround a linkage 18 (e.g., a shaft coupling of shafts 17 and 19), thereby thermally insulating the linkage 18 from the hot gas. The shaft 17 can be coupled to the gas turbine engine 12, while the shaft 19 can be coupled to a load, such as a generator 16.

[0028] The tunnel 32 may be removably coupled to the diverging section 60 and the diffuser opening 72. By removing the tunnel 32, other tunnels (see Figure 5 and Figure 8 ) replaceable tunnels 32, which results in a change in the interface 74 between the tunnel 32 and the turbine 12. By changing the interface 74, the various tunnels 32 enable the exhaust collector 30 to be used with multiple gas turbine engines by retrofitting the diverging section 60 of the exhaust collector 30 to the gas turbine engine 12. For example, the same diverging section 60 can be used in the exhaust collector 30 of a variety of different gas turbine engines 12, while the tunnel 32 varies in geometry to transition from the same diverging section 60 to the different geometries of the different gas turbine engines 12. In fact, selecting an appropriate tunnel 32 can expand the interface between the tunnel 32 and the gas turbine engine 12 (e.g., a larger diameter) or reduce the interface (e.g., a smaller diameter) so that a specific gas turbine engine 12 is suitable for using the exhaust collector 30. Therefore, depending on the geometry at the gas turbine engine 12 (e.g., a larger or smaller diameter), the tunnel 32 can have annular walls 33 of various shapes.

[0029] As described above, the annular wall 33 of the tunnel 32 may have a constant diameter (e.g., a cylindrical wall) or a variable diameter (e.g., a converging or diverging annular wall) in the flow direction 42 from the gas turbine engine 12 to the diverging section 60. For example, the variable diameter annular wall 33 may include a linear variable annular wall (e.g., a frustoconical wall), a curvilinear variable annular wall (e.g., a curved annular wall), or a stepped variable annular wall (e.g., an annular wall having a plurality of steps of different diameters). Depending on the specific application, the annular wall 33 may have any one or more of the aforementioned geometries in various combinations with each other. In the illustrated embodiment, the tunnel 32 has a substantially straight or uniform geometry (e.g., a cylindrical wall 33) having a constant or substantially constant diameter (e.g., a diameter that deviates by less than 1%) and is positioned coaxial with the longitudinal axis 44. The tunnel 32 is removably coupled to the diverging section 60 and the turbine frame 66. At the diverging section 60, a first end 76 of the tunnel 32 is secured to the diverging section 60 via a set of tunnel flanges 78 (e.g., circumferentially spaced apart flanges and / or annular flanges). The tunnel flanges 78 are bolted to the diverging section 60 and are used to secure these components together via a suitable number of fasteners (e.g., threaded bolts 75). The tunnel 32 passes through the diffuser 36, and a second end 79 of the tunnel 32 is secured to the turbine frame 66 via a turbine connection assembly 77. A partial cross-sectional view of the turbine connection assembly 77 is shown in FIG. Figure 3shown. The turbine connection assembly 77 may include a set of turbine frame flanges 80 (e.g., circumferentially spaced flanges and / or annular flanges). The second end 79 of the tunnel 32 is bolted to the turbine frame 66 and is used to fix the second end 79 of the tunnel 32 to the turbine frame 66. The second end 79 of the tunnel 32 may include a first seal 82 (e.g., circumferential or annular seal) disposed in an opening within a first seal groove 86 (e.g., circumferential or annular seal groove). The seal 82 may include one or more segments 84 (e.g., circumferential seal segments) that are circumferentially arranged about the longitudinal axis 44 to form a 360-degree structure (e.g., annular seal). The seal 82 may be decoupled at the groove end such that it can move freely within the opening of the first seal groove 86. The seal 82 may reduce the leakage of hot exhaust gases and reduce the likelihood of hot exhaust gases entering the tunnel 32.

[0030] The diffuser 36 is coupled to the exhaust collector frame 34 via a diffuser connection assembly 89. A partial cross-sectional view of the diffuser connection assembly 89 is shown in Figure 4 shown. The diffuser connection assembly 89 may include a set of exhaust hood flanges 88 (e.g., circumferentially spaced flanges and / or annular flanges). The exhaust hood flanges 88 are fastened to the exhaust collector frame 34 via a plurality of fasteners (e.g., threaded bolts 75) and are used to fix these components together. The exhaust hood flanges 88 may include a second seal groove 90 (e.g., circumferential or annular seal groove). One or more second seal segments 92 (e.g., circumferential seal segments) disposed along the outer surface 41 of the diffuser 36 may be fastened (e.g., via threaded bolts) into the second seal segments 92 to reduce the leakage of hot exhaust gases. The second seal segments 92 may be circumferentially disposed about the diffuser 36 to form a 360-degree structure (e.g., annular seal). The diffuser 36 may also be coupled to the turbine frame 66 upstream of the exhaust hood flanges 88 via a set of outer diffuser flanges 95 (e.g., circumferentially spaced flanges and / or annular flanges). The outer diffuser flanges 95 are fastened to the outer turbine flange connectors 96 via a plurality of fasteners (e.g., threaded bolts 75) to fix these components together.

[0031] As described above, the tunnel 32 passes through the diffuser 36. In the illustrated embodiment, the tunnel 32 and the diffuser 36 are directly coupled together without radial struts, couplings, or other support structures. The absence of radial struts, couplings, and other support structures allows the tunnel 32 to be more easily removed from the exhaust collector frame 34. The size of the tunnel 32 relative to the diffuser 36 may also allow the tunnel 32 to be more easily removed. In one embodiment, the diameter 98 (e.g., inner diameter or outer diameter) of the tunnel 32 can be any suitable size, such as between 14 inches and 54 inches, between 20 inches and 48 inches, between 24 inches and 44 inches, or any specific diameter therebetween. The diameter 100 (e.g., inner diameter or outer diameter) of the diffuser 36 can be any suitable size, such as between 34 inches and 136 inches, between 48 inches and 122 inches, between 60 inches and 110 inches, or any specific diameter therebetween.

[0032] Figure 5 Yes Figure 1 And Figure 2 Cross-sectional view of the exhaust collector 30 of the gas turbine system 10, where the exhaust collector 30 is modified (e.g., retrofitted) with an alternative embodiment of the tunnel 32. The components of the exhaust collector frame 34 and the diverging section 60 are the same as those referenced above Figure 2The components described above are generally the same and thus the discussion of these components will not be repeated. In the illustrated embodiment, the tunnel 32 has a tapered shape 102 along the annular wall 33 from the first end 76 to the second end 79 of the tunnel 32. The angle 104 of the tapered shape 102 may be about 2 degrees to 40 degrees, 3 degrees to 35 degrees, 4 degrees to 30 degrees, or 5 degrees to 25 degrees along the annular wall 33. In certain embodiments, the angle 104 may be greater than a minimum angle of 1 degree, 2 degrees, or 3 degrees and less than a maximum angle of 10 degrees, 15 degrees, 20 degrees, 25 degrees, or 30 degrees, or any combination of these minimum and maximum angles. The angle 104 may be constant or substantially constant (e.g., with a deviation of less than 1 degree) along a portion or all of the length between the first end 76 and the second end 79 (e.g., at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% of the length). If the angle 104 is constant or substantially constant, the annular wall 33 of the tunnel 32 may be described as a tapered annular wall (or a tapered annular wall portion if less than the entire length of the annular wall 33). Alternatively or additionally, the angle 104 may vary (e.g., vary in a curved manner by at least 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, or 10 degrees) along a portion or all of the length between the first end 76 and the second end 76 (e.g., at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% of the length). For example, if the angle 104 varies in a curved manner, the annular wall 33 of the tunnel 32 may be described as a curved annular wall (or a curved annular wall portion if less than the entire length of the annular wall 33). The annular wall 33 may reduce and / or distribute stress along the tunnel 32 by improving the capacity of the expected high stress regions of the walls 68, 70. The first end 76 of the tunnel 32 may be coupled to the diverging section 60, as described above with reference to Figure 2 described. That is, the first end 76 of the tunnel 32 may be coupled to the diverging section 60 via the set of tunnel flanges 78 (e.g., circumferentially spaced flanges and / or annular flanges).

[0033] Figure 6 is a partial cross-sectional view of an alternative embodiment of the turbine connection assembly 77, which may be used with Figure 5 the tapered tunnel 32 or Figure 3 and Figure 8used in conjunction with the illustrated tunnel 32. In the illustrated embodiment, the second end 79 of the tapered tunnel 32 may be coupled to the turbine frame bracket 80 via one or more fasteners (e.g., threaded bolts 75). The second end 79 of the tunnel 32 and the turbine frame bracket 80 may form a first seal groove 86 (e.g., an annular seal groove) for receiving a seal 82 (e.g., an annular seal or a circumferentially segmented seal). For example, the seal 82 may include a plurality of circumferential seal segments that are held in place, in part, by the force of the turbine frame bracket 80.

[0034] Figure 7 is a partial cross-sectional view of an alternative embodiment of the diffuser connection assembly 89 that may be used with Figure 5 the tapered tunnel 32 of Figure 3 and Figure 8 the illustrated tunnel 32. The diffuser connection assembly 89 may include a lip 93 that is connected (e.g., via a welded connection) to the outer surface 41 of the diffuser 36. The lip 93 (e.g., an annular lip) extends circumferentially around the outer surface 41 of the diffuser 36. The lip 93 may also include a seal segment 92 that is circumferentially disposed around the outer surface 41 of the diffuser 36. The diffuser connection assembly 89 includes at least two diffuser brackets 94 (e.g., circumferentially spaced brackets and / or annular brackets) to form a groove 90 (e.g., an annular seal groove) for receiving the seal segment 92. The diffuser brackets 94 may be coupled together via fasteners (e.g., threaded bolts 75). The diffuser brackets 94 may also be coupled to the exhaust hood flange 88.

[0035] Referring again to Figure 5 , the size of the diameter 98 (e.g., inner diameter or outer diameter) of the first end 76 of the tunnel 32 is sized to be different (e.g., larger) from the diameter 106 (e.g., inner diameter or outer diameter) of the second end 79 of the tunnel 32. Thus, the annular wall 33 of the tunnel 32 has a variable diameter between the first end 77 and the second end 79. The tapered tunnel 32 causes the interface between the second end 79 of the tunnel 32 and the turbine frame 66 to change. For example, the ratio of the diameter 98 (e.g., inner diameter or outer diameter) at the first end 76 to the diameter 106 (e.g., inner diameter or outer diameter) at the second end 79 is greater than 1, such as at least equal to or greater than 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.45, or 1.5. The tapered tunnel 32 causes the diverging section 60 (e.g., associated with Figure 2The same diverging section) can be used with different diffusers 36 of different gas turbine engines 12 (e.g., a low power turbine or other suitable turbine engine). For example, the diameter 106 and the angle 104 can be specifically selected to achieve a modification with different gas turbine engines 12 and / or different diffusers 36. Thus, the ratio of the diameter 100 (e.g., inner diameter or outer diameter) of the diffuser 36 to the diameter 106 (e.g., inner diameter or outer diameter) at the second end 79 can be equal to or greater than, for example, 1.5, 1.75, 2, 2.25, 2.5, 2.75, or 3.

[0036] In the illustrated embodiment, the diameter 98 (e.g., inner diameter or outer diameter) of the first end 76 of the tunnel 32 can be any suitable size, such as between 12 inches and 50 inches, between 18 inches and 44 inches, between 22 inches and 40 inches, or any specific diameter therebetween. And the diameter 106 (e.g., inner diameter or outer diameter) of the second end 79 of the tunnel 32 can be any suitable size, such as between 8 inches and 48 inches, between 14 inches and 42 inches, between 20 inches and 38 inches, or any specific diameter therebetween. In the illustrated embodiment, the diameter 100 (e.g., inner diameter or outer diameter) of the diffuser 36 can be any suitable size, such as between 34 inches and 136 inches, between 48 inches and 122 inches, between 60 inches and 110 inches, or any specific diameter therebetween. As described above, the tunnel 32 and the diffuser 36 are directly connected together without radial struts, connectors, or other support structures, so that the tunnel 32 can be more easily removed from the exhaust collector frame 34.

[0037] Figure 8 is Figure 1 、 Figure 2 and Figure 5 A cross-sectional view of the exhaust collector 30 of the gas turbine system 10, where the exhaust collector 30 is modified (e.g., retrofitted) with an alternative embodiment of the tunnel 32. The components of the exhaust collector frame 34 and the diverging section 60 are substantially the same as those described above with reference to Figure 2 and Figure 5 and thus the discussion of these components will not be repeated. In the illustrated embodiment, Figure 8 the exhaust collector 30 has a turbine connection assembly 77 as shown in Figure 9 and a diffuser connection assembly 89 as shown in Figure 10 . However, in some embodiments, Figure 8 the exhaust collector 30 can have a turbine connection assembly 77 as shown in Figure 3 and / or a diffuser connection assembly 89 as shown in Figure 4 .

[0038] In the illustrated embodiment, the tunnel 32 has a stepped portion 108 (e.g., an annular step or a sudden diameter change, such as a stepped wall portion) along the annular wall 33 between the first end 76 of the tunnel 32 and the second end 79 of the tunnel 32. The stepped portion 108 transitions between adjacent wall portions 107 and 109 of the annular wall 33 of the tunnel 32. Although Figure 8 only one stepped portion 108 is shown, embodiments of the tunnel 32 may include any number of stepped portions 108 (e.g., 1, 2, 3, 4, 5, 6, or more annular steps) between adjacent wall portions 107 and 109. The adjacent wall portions 107 and / or 109 may be cylindrical or conical. Each stepped portion 108 (such as the illustrated stepped portion 108) may change (e.g., decrease) the diameter of the annular wall 33 from wall portion 107 to wall portion 109 by some dimension or percentage. For example, with respect to the diameter of the annular wall 33 immediately preceding the stepped portion 108 (e.g., at wall portion 107), each stepped portion 108 may decrease the diameter 110 (e.g., inner diameter or outer diameter) of the annular wall 33 by at least 1 inch, 2 inches, 3 inches, 4 inches, 5 inches, 6 inches, 7 inches, 8 inches, 9 inches, 10 inches, or more inches, or by at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or more percentage. In some embodiments, the stepped portion 108 may decrease the diameter 110 to the same diameter 106 at the second end 79, or the stepped portion 108 may decrease the diameter 110 such that the angle 104 of the wall portion 107 is less than or equal to about 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, or 10 degrees. Additionally, the stepped portion 108 may have an angle 111 (e.g., an acute angle) relative to the longitudinal axis 44, such as between 15 degrees and 90 degrees, between 20 degrees and 75 degrees, between 30 degrees and 60 degrees, or between 40 degrees and 50 degrees. In some embodiments, the angle 111 of the stepped portion 108 may be generally the same as the angle 61 of the diverging section 60, where the angle 61 is also measured relative to the longitudinal axis 44. However, the angle 111 of the stepped portion 108 may be different from the angle 61 of the diverging section 60, such as a larger angle to more rapidly transition to a smaller diameter 110.

[0039] Similar to Figure 5In the illustrated embodiment, the first end 76 of the tunnel 32 has a larger diameter 98 (e.g., inner diameter or outer diameter) relative to the diameter 106 (e.g., inner diameter or outer diameter) of the second end 79 of the tunnel 32. Thus, the stepped portion 108 enables the interface between the second end 79 of the tunnel 32 and the frame 66 to be changed. In the illustrated embodiment, the first end 76 of the tunnel 32 has a diameter 90 (e.g., inner diameter or outer diameter) that is between 12 inches and 50 inches, between 18 inches and 44 inches, between 22 inches and 40 inches, or any specific diameter therebetween. At the first step 108, the tunnel diameter is reduced, and the tunnel diameter 110 is between 8 inches and 48 inches, between 14 inches and 42 inches, between 20 inches and 38 inches, or any specific diameter therebetween. The inner diameter 106 of the second end 79 of the tunnel 32 is between 10 inches and 46 inches, between 16 inches and 40 inches, between 22 inches and 36 inches, or any specific diameter therebetween. The illustrated tunnel 32 (e.g., a stepped tunnel) is disposed between the diverging section 60 and different diffusers 36 of different gas turbine engines 12. In the illustrated embodiment, the second diffuser 36 has a diameter 100 (e.g., an inner diameter or an outer diameter), which may be any suitable size, such as between 34 inches and 136 inches, between 48 inches and 122 inches, between 60 inches and 110 inches, or any specific diameter therebetween.

[0040] Figure 9 In the use of the embodiment disclosed herein Figures 2 to 8 A method 200 of removing multiple portions of an exhaust collector assembly 14 (e.g., a first tunnel 32 and a first diffuser 36) in preparation for retrofitting one of a retrofit kit of a power turbine 12. The method 200 includes disengaging (frame 202) the power turbine 12 and the tunnel 32. The method 200 includes separating (frame 204) the rear wall 56 of the packaged housing 30. By removing the rear wall 56 of the exhaust hood 30, the tunnel 32 and the diffuser 36 can be removed from the exhaust hood 30. The method 200 includes decoupling (frame 206) the tunnel 32 from a diverging section 60 (e.g., a deflector section). Decoupling the tunnel 32 may include uncoupling the first end 76 of the tunnel 32 from the diverging section 60 (e.g., a deflector section). The method 200 includes disengaging a seal 82 of the tunnel 32. Disengaging the seal 82 may include removing the turbine frame 80 from the second end 79 of the tunnel 32. The method 200 includes removing the installed tunnel 32 from the exhaust collector 30 along the axis 38 (block 208). The method 200 includes decoupling the diffuser 36 from the turbine 12 (block 210). Decoupling the diffuser 36 may include disassembling the diffuser bracket 94 from the exhaust hood flange 88. The method includes disengaging (block 212) the diffuser seal 92. The method 200 includes removing the installed diffuser 36 along the axis 38.

[0041] Figure 10 Shows the installation Figures 2 to 8 Method 300 of one of the modification kits of Figure 9 The method 200 of the present invention is followed by installing a different replacement tunnel 32 and a different replacement diffuser 36 to modify the method according to the embodiments disclosed herein. Figure 1 The method 300 may include installing (frame 302) a replacement diffuser 36 into the exhaust hood 30. The method 300 also includes attaching (frame 304) the replacement diffuser 36 to the turbine frame 66 by bolting the diffuser 36 to the turbine frame 66 via one or more bolt and flange connections or brackets, thereby securing the smaller diameter end 46 of the diffuser 36 to the turbine frame 66. The method 300 includes engaging (frame 306) a replacement seal 92 of the replacement diffuser 36. The method 300 includes installing (frame 308) a replacement tunnel 32. The method 300 includes coupling (frame 310) a first end 76 of the tunnel 32 to a diverging section 60 (e.g., a deflector section). Coupling the first end 76 of the tunnel 32 to the diverging section 60 (e.g., a deflector section) may include bolting the first end 76 of the tunnel 32 to one or more tunnel flanges 78 at the diverging section 60. The method 300 includes engaging (block 312) the seal 82 at the opposite second end 79 of the tunnel 32. Once the tunnel 32 is installed, the method 300 includes replacing (block 314) the rear wall 56 of the exhaust hood 30. The above-described methods 200 and 300 may be used to modify (e.g., retrofit) the exhaust collector assembly 14 to Figures 1 to 8 Varying between any of the illustrated embodiments allows the exhaust collector assembly 14 to be used with any desired gas turbine engine 12 (eg, switching between different sizes, models, types, etc. having different dimensions at the connections to the exhaust collector assembly 14 ).

[0042] The technical effects of the present invention include the ability to use a retrofit kit including a tunnel that enables a specific exhaust system (e.g., an exhaust collector) designed for a larger turbine engine to be used with a different turbine engine by changing the interface between the tunnel and the turbine frame. The retrofit kit includes one or more diffusers, tunnels, and one or more sealing assemblies for reducing exhaust gas leakage having different sizes and interfaces. The tunnel may have straight, tapered, curved, stepped, or other suitably shaped walls to fit between the exhaust collector and the turbine frame. Thus, the retrofit kit enables an exhaust collector designed for a larger gas turbine engine to be used on other models of gas turbine engines without extensive modifications to the exhaust collector frame or other housings for various components of a gas turbine engine power station.

[0043] This written description uses examples to disclose the claimed subject matter, including the best mode, and also enables any person skilled in the art to practice the subject matter, including making and using any device or system and performing any combined method. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ in substance from the literal language of the claims.

Claims

1. A system, comprising: An exhaust collector tunnel (32) configured to be installed inside an exhaust collector (30) of a gas turbine (12), wherein the exhaust collector tunnel (32) includes a tunnel wall (33) configured to extend around turbine shafts (17, 19) of the gas turbine (12); Wherein the exhaust collector tunnel (32) includes a first end portion (79) configured to extend at least partially into an exhaust diffuser (36) and a second end portion (76) configured to be coupled to a diverging section (60) of the exhaust collector (30), and the diverging section (60) is disposed downstream of the exhaust diffuser (36); Wherein when the system is in operation, an exhaust flow path extends through the exhaust diffuser (36), along the tunnel wall (33) of the exhaust collector tunnel (32), and along the diverging section (60); Wherein the tunnel wall (33) has a variable diameter (98) along at least a portion of the length of the exhaust collector tunnel (32); Wherein the variable diameter (98) includes a conical wall portion (102) and a second wall portion, the conical wall portion (102) has an angle (104) relative to a longitudinal axis (44) of the exhaust collector tunnel (32), the angle (104) is less than or equal to 30 degrees, and the second wall portion has an angle different from that of the conical wall portion, and the conical wall portion (102) extends along at least 10% of the exhaust collector tunnel (32).

2. The system according to claim 1, wherein the variable diameter (98) is configured such that a retrofit of the exhaust collector (30) can adapt to the geometry of the gas turbine (12).

3. The system according to claim 2, wherein the exhaust collector tunnel (32) is configured to replace a different exhaust collector tunnel (32) to effect connection of the exhaust collector (30) to the gas turbine (12), and the different exhaust collector tunnel (32) is not configured to be connected to the gas turbine (12).

4. The system according to claim 1, wherein the diverging section (60) includes a deflector section.

5. The system according to claim 1, including the exhaust collector (30) having the exhaust diffuser (36) and the diverging section (60).

6. The system according to claim 5, including the gas turbine (12) configured to be coupled to the exhaust collector (30).

7. The system according to claim 1, including an exhaust diffuser (36), wherein the exhaust collector tunnel (32) extends at least partially into the exhaust diffuser (36), and the exhaust collector tunnel (32) is not directly coupled to the exhaust diffuser (36).

8. The system according to claim 1, wherein the conical wall portion (102) includes a generally constant angle (104) relative to the longitudinal axis (44) of the exhaust collector tunnel (32).

9. The system according to claim 1, wherein the conical wall portion (102) includes a variable angle (104) relative to the longitudinal axis (44) of the exhaust collector tunnel (32).

10. The system according to claim 1, wherein the conical wall portion (102) extends along at least 50% of the length of the exhaust collector tunnel (32).

11. The system according to claim 1, wherein the variable diameter (98) includes a stepped wall portion (108).

12. A method of operating the system according to claim 1, comprising: Installing an exhaust collector tunnel (32) inside an exhaust collector (30) of a gas turbine (12), wherein the exhaust collector tunnel (32) includes a tunnel wall (33) configured to extend around a turbine shaft (17, 19) of the gas turbine (12), and the tunnel wall (33) has a variable diameter (98) along at least a portion of the length of the exhaust collector tunnel (32).

13. The method according to claim 12, comprising: Removing a different exhaust collector tunnel (32) from the exhaust collector (30) before installing the exhaust collector tunnel (32), wherein the different exhaust collector tunnel (32) is configured to fit another gas turbine (12) different from the gas turbine (12).

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