Patent Application
20140137536
The subject matter disclosed herein relates to gas turbine systems, and more particularly to a cross-fire tube, as well as a method of assembling a combustor structure.
Adjacent combustors of a gas turbine engine are typically connected by a cross-fire tube to ensure substantially simultaneous ignition and equalized pressure in all combustor chambers of the gas turbine engine. The cross-fire tube is typically coupled to the adjacent combustors by a variety of retention devices, including clips, for example. Geometry constraints and spatial limitations may hinder the ability to employ such retention devices. Additionally, the adjacent combustors may be assembled as a module that is inserted as a whole into a combustor structure. Assembly in this manner may limit the retention methods that are commonly required for cross-fire tubes having a relatively rigid construction or one of limited flexibility to accommodate the insertion of the module into the combustor structure, as at least a portion of the cross-fire tube is typically disposed in the space that is to receive the module. Furthermore, installation of the cross-fire tube requires proper positioning of the cross-fire tube, relative to other components, with the positioning left to an installation operator's discretion or manipulating, thereby often leading to human error.
According to one aspect of the invention, a super-telescoping cross-fire tube includes a cross-fire tube including a first portion and a second portion in mating engagement, the cross-fire tube extending from a first end region to a second end region for fluidly connecting a combustor chamber and an adjacent combustor chamber. Also included is an outer shield spaced radially outwardly and surrounding at least a portion of the cross-fire tube. Further included is a spring extending from proximate the first end region to the second end region and disposed between the cross-fire tube and the outer shield, wherein the cross-fire tube is telescopingly moveable between a first position and a second position.
According to another aspect of the invention, a combustor structure for a gas turbine engine includes a combustor assembly and an adjacent combustor assembly, the combustor assembly comprising a combustor chamber, the adjacent combustor assembly comprising an adjacent combustor chamber. Also included is a first collar operably coupled to the combustor assembly. Further included is a cross-fire tube extending from a first end region disposed adjacent the first collar to a second end region disposed proximate the adjacent combustor assembly. Yet further included is a spring extending from proximate the first end region to the second end region and disposed between the cross-fire tube and an outer shield surrounding at least a portion of the cross-fire tube.
According to yet another aspect of the invention, a method of assembling a combustor structure is provided. The method includes inserting a first portion of a cross-fire tube into a portion of a combustor assembly. Also included is rotating the first portion of the cross-fire tube to align an anti-rotation surface of the first portion with a corresponding anti-rotation feature of a first collar operably coupled to the combustor assembly. Further included is matably engaging a second portion of the cross-fire tube with the first portion, wherein a spring is positioned from the first portion to the second portion. Yet further included is compressing the cross-fire tube from a first position to a second position providing clearance for insertion of an adjacent combustor assembly into the combustor structure.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
Referring to
In operation, air flows into the compressor 12 and is compressed into a high pressure gas. The high pressure gas is supplied to the combustor assembly 14 and mixed with fuel, for example natural gas, fuel oil, process gas and/or synthetic gas (syngas), in the combustor chamber 18. The fuel/air or combustible mixture ignites to form a high pressure, high temperature combustion gas stream. In any event, the combustor assembly 14 channels the combustion gas stream to the turbine 24 which converts thermal energy to mechanical, rotational energy.
Referring now to
The cross-fire tube 40 includes an outer surface 62 and an inner surface 64, with the inner surface 64 defining an interior region 68 that provides the fluid coupling of the combustor chamber 18 and the adjacent combustor chamber 34, which allows passage of a flame from the combustor chamber 18 to the adjacent combustor chamber 34, or vice versa. Such passage is desirable during light-off of the combustor assemblies of the gas turbine engine 10 and allows for nearly simultaneous ignition or re-ignition of the combustor assemblies.
Disposed along the outer surface 62 is a spring 70 that extends from proximate the first end region 44 of the cross-fire tube 40 to proximate the second end region 50 of the cross-fire tube 40. The spring 70 is at least partially retained by an outer shield 72 that surrounds the outer surface 62 of the cross-fire tube 40. The outer shield 72 is spaced radially outwardly from the outer surface 62 to accommodate disposal of the spring 70 between the cross-fire tube 40 and the outer shield 72. In the illustrated embodiment, the outer shield 72 is segmented to only surround portions of the cross-fire tube 40 and the spring 70. Specifically, the outer shield 72 surrounds a portion of the first portion 58 and a portion of the second portion 60 of the cross-fire tube 40. However, it is to be understood that the outer shield 72 may extend along an entire, or nearly an entire, length of the cross-fire tube 40. Irrespective of the amount of the cross-fire tube 40 that is surrounded by the outer shield 72, the spring 70 provides a resilient spring biasing force on the first portion 58 and the second portion 60 of the cross-fire tube 40. The cross-fire tube 40 is telescopingly moveable between a first extended position, as shown, and a second compressed position upon compression of the spring 70. As will be described in detail below, compression of the cross-fire tube 40 and the spring 70 is advantageous during certain phases of assembly of the combustor assembly 14 and the adjacent combustor assembly 32.
Referring now to
Both the first collar 80 and the second collar 82 include a central opening 84 for receiving the first end region 44 and the second end region 50, respectively, of the cross-fire tube 40. The first end region 44 and the second end region 50 include an anti-rotation surface 86 that corresponds to at least one anti-rotation component 88 of the first collar 80 and the second collar 82. In an exemplary embodiment, the at least one anti-rotation component 88 and the anti-rotation surface 86 comprise corresponding non-planar surfaces each having conical regions. It is to be appreciated that numerous alternative geometries may be employed and furthermore it is contemplated that corresponding protrusions and recesses may be utilized to form the anti-rotation surface 86 and the at least one anti-rotation component 88. Irrespective of the precise configuration of the anti-rotation surface 86 and the at least one anti-rotation component 88, the corresponding features provide a self-aligning aspect for the cross-fire tube arrangement 42. Specifically, disposal of the cross-fire tube 40 into an abutting manner with the first collar 80 and the second collar 82 provides a fixed rotational position of the cross-fire tube 40, thereby reducing judgment of an installation operator.
During operation of the combustor assembly 14 and the adjacent combustor assembly 32, the first end region 44 and the second end region 50 are particularly susceptible to high temperatures due to exposure to the combustor chamber 18 and the adjacent combustor chamber 34. A plurality of cooling holes 90 are formed in the first collar 80 and the second collar 82 in a region adjacent the first end region 44 and the second end region 50 for cooling purposes. It is noted that the first end region 44 and the second end region 50 are formed of smooth contours, such as circular, elliptical or the like. These smooth contours reduce any disturbance of an airflow passing through an annulus between the combustor liner 46 and the sleeve 48 and/or the air shield 49.
Referring now to
To provide clearance for portions of the combustor assembly 14, such as a module that is inserted into the combustor assembly 14, the cross-fire tube 40 is moveable between a first position 94, as shown in
As illustrated in the flow diagram of
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
