Patent Publication Number: US-8978388-B2

Title: Load member for transition duct in turbine system

Description:
FIELD OF THE INVENTION 
     The subject matter disclosed herein relates generally to turbine systems, and more particularly to load members and loading assemblies for transition ducts in turbine systems. 
     BACKGROUND OF THE INVENTION 
     Turbine systems are widely utilized in fields such as power generation. For example, a conventional gas turbine system includes a compressor section, a combustor section, and at least one turbine section. The compressor section is configured to compress air as the air flows through the compressor section. The air is then flowed from the compressor section to the combustor section, where it is mixed with fuel and combusted, generating a hot gas flow. The hot gas flow is provided to the turbine section, which utilizes the hot gas flow by extracting energy from it to power the compressor, an electrical generator, and other various loads. 
     The compressor sections of turbine systems generally include tubes or ducts for flowing the combusted hot gas therethrough to the turbine section or sections. Recently, compressor sections have been introduced which include tubes or ducts that shift the flow of the hot gas. For example, ducts for compressor sections have been introduced that, while flowing the hot gas longitudinally therethrough, additionally shift the flow radially or tangentially such that the flow has various angular components. These designs have various advantages, including eliminating first stage nozzles from the turbine sections. The first stage nozzles were previously provided to shift the hot gas flow, and may not be required due to the design of these ducts. The elimination of first stage nozzles may eliminate associated pressure drops and increase the efficiency and power output of the turbine system. 
     However, the movement and interaction of adjacent ducts in a turbine system is of increased concern. For example, because the ducts do not simply extend along a longitudinal axis, but are rather shifted off-axis from the inlet of the duct to the outlet of the duct, thermal expansion of the ducts can cause undesirable shifts in the ducts along or about various axes. These shifts can cause stresses and strains within the ducts, and may cause the ducts to fail. Further, loads carried by the ducts may not be properly distributed and, when shifting occurs, the loads may not be properly transferred between the various ducts. 
     Thus, an improved load member and loading assembly for ducts in a turbine system would be desired in the art. For example, a load member and loading assembly that allow for thermal growth of the duct and transfer loads between adjacent ducts would be advantageous. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     In one embodiment, a loading assembly for a turbine system is disclosed. The loading assembly includes a transition duct extending between a fuel nozzle and a turbine section. The transition duct has an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The mounting assembly further includes a load member extending from the transition duct. The load member is configured to transfer a load between the transition duct and an adjacent transition duct along at least one of the longitudinal axis, the radial axis, or the tangential axis. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG. 1  is a cross-sectional view of several portions of a gas turbine system according to one embodiment of the present disclosure; 
         FIG. 2  is a perspective view of an annular array of transition ducts according to one embodiment of the present disclosure; 
         FIG. 3  is a rear right side perspective view of a loading assembly according to one embodiment of the present disclosure; 
         FIG. 4  is a rear left side perspective view of a loading assembly according to another embodiment of the present disclosure; 
         FIG. 5  is a top view of a loading assembly according to one embodiment of the present disclosure; 
         FIG. 6  is a top view of a loading assembly according to another embodiment of the present disclosure; 
         FIG. 7  is a top view of a loading assembly according to another embodiment of the present disclosure; 
         FIG. 8  is a top view of a loading assembly according to another embodiment of the present disclosure; 
         FIG. 9  is a rear view of a loading assembly according to one embodiment of the present disclosure; 
         FIG. 10  is a rear view of a loading assembly according to another embodiment of the present disclosure; 
         FIG. 11  is a top view of a loading assembly according to one embodiment of the present disclosure; and 
         FIG. 12  is a top view of a loading assembly according to another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
     Referring to  FIG. 1 , a simplified drawing of several portions of a gas turbine system  10  is illustrated. It should be understood that the turbine system  10  of the present disclosure need not be a gas turbine system  10 , but rather may be any suitable turbine system  10 , such as a steam turbine system or other suitable system. 
     The gas turbine system  10  as shown in  FIG. 1  comprises a compressor section  12  for pressurizing a working fluid, discussed below, that is flowing through the system  10 . Pressurized working fluid discharged from the compressor section  12  flows into a combustor section  14 , which is generally characterized by a plurality of combustors  16  (only one of which is illustrated in  FIG. 1 ) disposed in an annular array about an axis of the system  10 . The working fluid entering the combustor section  14  is mixed with fuel, such as natural gas or another suitable liquid or gas, and combusted. Hot gases of combustion flow from each combustor  16  to a turbine section  18  to drive the system  10  and generate power. 
     A combustor  16  in the gas turbine  10  may include a variety of components for mixing and combusting the working fluid and fuel. For example, the combustor  16  may include a casing  20 , such as a compressor discharge casing  20 . A variety of sleeves, which may be axially extending annular sleeves, may be at least partially disposed in the casing  20 . The sleeves, as shown in  FIG. 1 , extend axially along a generally longitudinal axis  90 , such that the inlet of a sleeve is axially aligned with the outlet. For example, a combustor liner  22  may generally define a combustion zone  24  therein. Combustion of the working fluid, fuel, and optional oxidizer may generally occur in the combustion zone  24 . The resulting hot gases of combustion may flow generally axially along the longitudinal axis  42  downstream through the combustion liner  22  into a transition piece  26 , and then flow generally axially along the longitudinal axis  90  through the transition piece  26  and into the turbine section  18 . 
     The combustor  16  may further include a fuel nozzle  40  or a plurality of fuel nozzles  40 . Fuel may be supplied to the fuel nozzles  40  by one or more manifolds (not shown). As discussed below, the fuel nozzle  40  or fuel nozzles  40  may supply the fuel and, optionally, working fluid to the combustion zone  24  for combustion. 
     As shown in  FIGS. 2 through 12 , a combustor  16  according to the present disclosure may include a transition duct  50  extending between the fuel nozzle  40  or fuel nozzles  40  and the turbine section  18 . The transition ducts  50  of the present disclosure may be provided in place of various axially extending sleeves of other combustors. For example, a transition duct  50  may replace the axially extending combustor liner  22  and transition piece  26  of a combustor, and, as discussed below, may provide various advantages over the axially extending combustor liners  22  and transition pieces  26  for flowing working fluid therethrough and to the turbine section  18 . 
     As shown, the plurality of transition ducts  50  may be disposed in an annular array about longitudinal axis  90 . Further, each transition duct  50  may extend between a fuel nozzle  40  or plurality of fuel nozzles  40  and the turbine section  18 . For example, each transition duct  50  may extend from the fuel nozzles  40  to the transition section  18 . Thus, working fluid may flow generally from the fuel nozzles  40  through the transition duct  50  to the turbine section  18 . In some embodiments, the transition ducts  50  may advantageously allow for the elimination of the first stage nozzles in the turbine section, which may eliminate any associated drag and pressure drop and increase the efficiency and output of the system  10 . 
     Each transition duct  50  may have an inlet  52 , an outlet  54 , and a passage  56  therebetween. The inlet  52  and outlet  54  of a transition duct  50  may have generally circular or oval cross-sections, rectangular cross-sections, triangular cross-sections, or any other suitable polygonal cross-sections. Further, it should be understood that the inlet  52  and outlet  54  of a transition duct  50  need not have similarly shaped cross-sections. For example, in one embodiment, the inlet  52  may have a generally circular cross-section, while the outlet  54  may have a generally rectangular cross-section. 
     Further, the passage  56  may be generally tapered between the inlet  52  and the outlet  54 . For example, in an exemplary embodiment, at least a portion of the passage  56  may be generally conically shaped. Additionally or alternatively, however, the passage  56  or any portion thereof may have a generally rectangular cross-section, triangular cross-section, or any other suitable polygonal cross-section. It should be understood that the cross-sectional shape of the passage  56  may change throughout the passage  56  or any portion thereof as the passage  56  tapers from the relatively larger inlet  52  to the relatively smaller outlet  54 . 
     In some embodiments, as shown in  FIGS. 4 through 7 , a transition duct  50  according to the present disclosure may comprise an aft frame  58 . The aft frame  58  may generally be a flange-like frame surrounding the exterior of the transition duct  50 . The aft frame  58  may be located generally adjacent to the outlet  54 . Further, the aft frame  58 , while adjacent to the outlet  54 , may be spaced from the outlet  54 , or may be provided at the outlet to connect the transition duct  50  to the turbine section  18 . 
     As mentioned above, the plurality of transition ducts  50  may be disposed in an annular array about longitudinal axis  90 . Thus, any one or more of the transition ducts  50  may be referred to as a first transition duct  62 , and a transition duct  50  adjacent to the first transition duct  62 , such as adjacent in the annular array, may be referred to as a second transition duct  64 . 
     The outlet  54  of each of the plurality of transition ducts  50  may be offset from the inlet  52  of the respective transition duct  50 . The term “offset”, as used herein, means spaced from along the identified coordinate direction. The outlet  54  of each of the plurality of transition ducts  50  may be longitudinally offset from the inlet  52  of the respective transition duct  50 , such as offset along the longitudinal axis  90 . 
     Additionally, in exemplary embodiments, the outlet  54  of each of the plurality of transition ducts  50  may be tangentially offset from the inlet  52  of the respective transition duct  50 , such as offset along a tangential axis  92 . Because the outlet  54  of each of the plurality of transition ducts  50  is tangentially offset from the inlet  52  of the respective transition duct  50 , the transition ducts  50  may advantageously utilize the tangential component of the flow of working fluid through the transition ducts  30  to eliminate the need for first stage nozzles (not shown) in the turbine section  18 . 
     Further, in exemplary embodiments, the outlet  54  of each of the plurality of transition ducts  50  may be radially offset from the inlet  52  of the respective transition duct  50 , such as offset along a radial axis  94 . Because the outlet  54  of each of the plurality of transition ducts  50  is radially offset from the inlet  52  of the respective transition duct  50 , the transition ducts  50  may advantageously utilize the radial component of the flow of working fluid through the transition ducts  30  to further eliminate the need for first stage nozzles (not shown) in the turbine section  18 . 
     It should be understood that the tangential axis  92  and the radial axis  94  are defined individually for each transition duct  50  with respect to the circumference defined by the annular array of transition ducts  50 , as shown in  FIG. 2 , and that the axes  92  and  94  vary for each transition duct  50  about the circumference based on the number of transition ducts  50  disposed in an annular array about the longitudinal axis  90 . 
     During operation of the system  10 , each transition duct  50  may experience thermal growth and/or other various interactions that cause movement of the transition ducts  50  about and/or along various of the axes. Loads incurred by the transition ducts  50  during such operation must be transferred and thus reacted between adjacent ducts  50  in order to prevent damage or failure to the ducts  50 . 
     Thus, the present disclosure is further directed to a load member  100  and a loading assembly  102  for a turbine system  10 . The loading assembly  102  may comprise the transition duct  50  or transition ducts  50  extending between the fuel nozzle  40  and turbine section  18 , and a load member  100  or load members  100 . Each load member  100  may extend from a transition duct  50 , such as from a first transition duct  62  or second transition duct  64 . In some embodiments, for example, a load member  100  may be integral with the transition duct  50 . In these embodiments, the load member  100  and transition duct  50  are formed as a singular component. In other embodiments, the load member  100  may be mounted to the transition duct  50 . For example, the load member  100  may be welded, soldered, adhered with a suitable adhesive, or fastened with suitable mechanical fasteners such as rivet, nut/bolt combination, nail, or screw, to the transition duct  50 . 
     Each load member  100  may be configured to transfer a load between a transition duct  50  and an adjacent transition duct  50 , such as between first and second transition ducts  62  and  64 . For example, the load members  100  may be sized such that the load member  100  contacts the adjacent transition duct  50  during operation of the system  10 , when the transition duct  50  incurs a load about or along a certain axis or axes. When this loading occurs, the transition duct  50  may shift. This shift and the associated load may be transferred through the contact between the load member  100  and the adjacent transition duct  50  to the adjacent transition duct  50 . Thus, the load members  100  advantageously react various loads between the various transition ducts  50  in the system  10 . 
     In general, the load members  100  may have any suitable cross-sectional shape, such as rectangular or square, oval or circular, triangular, or any other suitable polygonal cross-sectional shape. Further, the load members  100  may have any size suitable for contacting adjacent transition ducts  50  during operation, and transferring loads between the adjacent transition ducts  50 . 
     A load may be transferred by a load member  100  along any of the longitudinal axis  90 , the tangential axis  92 , or the radial axis  94 . For example,  FIGS. 3 through 6  illustrate various embodiments of a load member  100  configured to transfer a load along tangential axis  92 . During operation, a transition duct  50 , such as first transition duct  62 , may move along the tangential axis  92 , such as because of twisting about the longitudinal axis  90  and/or radial axis  94 . When this occurs, the load member  100  extending from the transition duct  50  may contact the adjacent transition duct  50  and transfer at least a portion of this load to the adjacent transition duct, such as second transition duct  64 . In exemplary embodiments, this loading may occur for each transition duct  50  with respect to the adjacent transition duct  50  in the annular array of transition ducts  50 , such that the loads on the transition ducts  50  in the system are reacted and transferred generally evenly throughout the annular array. 
       FIGS. 3 through 5  illustrate a load member  100  extending from a transition duct, such as first transition duct  62 , and configured to transfer a load along tangential axis  92  between the transition duct  50  and an adjacent transition duct  50 , such as second transition duct  64 .  FIG. 6  illustrates a first load member  112  and a second load member  114 . The first load member  112  extends from a first transition duct  62 , while the second load member extends from a second transition duct  64 . Each of the first load member  112  and second load member  114  are configured to transfer a load along tangential axis  92  between the first transition duct  62  and the second transition duct  64 , such as second transition duct  64 . Further, it should be understood that any suitable number of load members  100  may be provided extending from a transition duct  50 , an adjacent transition duct  50 , or both, to transfer loads along the tangential axis  92  as required. 
     As shown in  FIG. 6 , the first load member  112  and second load member  114  may further be configured to transfer a load along the longitudinal axis  90 . For example, during operation, a transition duct  50 , such as first transition duct  62 , may move along the longitudinal axis  90 , such as because of twisting about the tangential axis  92  and/or radial axis  94 . When this occurs, the first load member  112  extending from the first transition duct  62  may contact the second load member  114  extending from the second transition duct  64  and transfer at least a portion of this load to the second load member  114 . In exemplary embodiments, this loading may occur for each transition duct  50  with respect to the adjacent transition duct  50  in the annular array of transition ducts  50 , such that the loads on the transition ducts  50  in the system are reacted and transferred generally evenly throughout the annular array. 
       FIGS. 7 and 8  illustrate various embodiments of a load member  100  configured to transfer a load along longitudinal axis  90 . During operation, a transition duct  50 , such as first transition duct  62 , may move along the longitudinal axis  90 , such as because of twisting about the tangential axis  92  and/or radial axis  94 . When this occurs, the load member  100  extending from the transition duct  50  may contact the adjacent transition duct  50  and transfer at least a portion of this load to the adjacent transition duct, such as second transition duct  64 . In exemplary embodiments, this loading may occur for each transition duct  50  with respect to the adjacent transition duct  50  in the annular array of transition ducts  50 , such that the loads on the transition ducts  50  in the system are reacted and transferred generally evenly throughout the annular array. 
       FIG. 7  illustrates a load member  100  extending from a transition duct, such as first transition duct  62 , and configured to transfer a load along longitudinal axis  90  between the transition duct  50  and an adjacent transition duct  50 , such as second transition duct  64 .  FIG. 8  illustrates a first load member  112  and a second load member  114 . The first load member  112  extends from a first transition duct  62 , while the second load member extends from a second transition duct  64 . Each of the first load member  112  and second load member  114  are configured to transfer a load along longitudinal axis  90  between the first transition duct  62  and the second transition duct  64 , such as second transition duct  64 . Further, it should be understood that any suitable number of load members  100  may be provided extending from a transition duct  50 , an adjacent transition duct  50 , or both, to transfer loads along the longitudinal axis  90  as required. 
     As shown in  FIG. 8 , the first load member  112  and second load member  114  may further be configured to transfer a load along the tangential axis  92 . For example, during operation, a transition duct  50 , such as first transition duct  62 , may move along the tangential axis  92 , such as because of twisting about the longitudinal axis  90  and/or radial axis  94 . When this occurs, the first load member  112  extending from the first transition duct  62  may contact the second load member  114  extending from the second transition duct  64  and transfer at least a portion of this load to the second load member  114 . In exemplary embodiments, this loading may occur for each transition duct  50  with respect to the adjacent transition duct  50  in the annular array of transition ducts  50 , such that the loads on the transition ducts  50  in the system are reacted and transferred generally evenly throughout the annular array. 
       FIGS. 9 and 10  illustrate further various embodiments of a load member  100  configured to transfer a load along tangential axis  92 . During operation, a transition duct  50 , such as first transition duct  62 , may move along the tangential axis  92 , such as because of twisting about the longitudinal axis  90  and/or radial axis  94 . When this occurs, the load member  100  extending from the transition duct  50  may contact the adjacent transition duct  50  and transfer at least a portion of this load to the adjacent transition duct, such as second transition duct  64 . In exemplary embodiments, this loading may occur for each transition duct  50  with respect to the adjacent transition duct  50  in the annular array of transition ducts  50 , such that the loads on the transition ducts  50  in the system are reacted and transferred generally evenly throughout the annular array. 
       FIG. 9  illustrates a load member  100  extending from a transition duct, such as first transition duct  62 , and configured to transfer a load along tangential axis  92  between the transition duct  50  and an adjacent transition duct  50 , such as second transition duct  64 .  FIG. 10  illustrates a first load member  112  and a second load member  114 . The first load member  112  extends from a first transition duct  62 , while the second load member extends from a second transition duct  64 . Each of the first load member  112  and second load member  114  are configured to transfer a load along tangential axis  92  between the first transition duct  62  and the second transition duct  64 , such as second transition duct  64 . Further, it should be understood that any suitable number of load members  100  may be provided extending from a transition duct  50 , an adjacent transition duct  50 , or both, to transfer loads along the tangential axis  92  as required. 
     As shown in  FIG. 10 , the first load member  112  and second load member  114  may further be configured to transfer a load along the radial axis  94 . For example, during operation, a transition duct  50 , such as first transition duct  62 , may move along the radial axis  94 , such as because of twisting about the longitudinal axis  90  and/or tangential axis  92 . When this occurs, the first load member  112  extending from the first transition duct  62  may contact the second load member  114  extending from the second transition duct  64  and transfer at least a portion of this load to the second load member  114 . In exemplary embodiments, this loading may occur for each transition duct  50  with respect to the adjacent transition duct  50  in the annular array of transition ducts  50 , such that the loads on the transition ducts  50  in the system are reacted and transferred generally evenly throughout the annular array. 
     It should further be understood that the present disclosure is not limited to load members  100  configured to transfer loads mainly along only one axis. For example, the above various embodiments disclose various load members  100  configured to transfer loads mainly along one axis because of movement about another axis. However, it should be understood that movement may occur about or along more than one axis at once, and that any of the above disclosed embodiments of various load members  100  may transfer loads along any number of axes based on this movement. 
     Further, in some embodiments, a load member  100  may extend from a transition duct  50  according to the present disclosure and be configured to transfer loads along more than one of the longitudinal axis  90 , the tangential axis  92 , and the radial axis  94 . For example, as shown in  FIGS. 11 and 12 , a load member  100  or first and second load members  112  and  114  may extend from the transition duct  50  or first and second transition ducts  62  and  64  and contact the adjacent respective transition ducts  50  at an angle between the longitudinal axis  90  and the tangential axis  92 . These load members  100  may thus transfer loads along both the longitudinal axis  90  and the tangential axis  92 . 
     In some embodiments, as shown in  FIGS. 4 through 8 ,  11 , and  12 , the load members  100  may extend from an aft frame  58  of the transition duct  50 . In other embodiments, as shown in  FIGS. 3 ,  9 , and  10 , the load members  100  may simply extend from the passage  56  of the transition duct  50 . 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated 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. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.