Patent Application
20160258628
The present disclosure relates generally to turbine engines and, more specifically, to liquid fuel cartridges for turbine engine combustor fuel nozzles.
At least some known turbine engines are configured for use with both gaseous and liquid fuels. More specifically, at least some known turbine engines are configured to combust gaseous fuels under typical operating conditions. However, occasionally conditions may exist during which operation with gaseous fuels may not be possible, due to unavailability of gaseous fuel, for example. Accordingly, combustors in such turbine engines are provided with both gaseous fuel nozzles and liquid fuel cartridges. The combustors may have a can-shaped configuration, with an end cover oriented on a “cold” end of the combustor. The liquid fuel cartridges may be configured for insertion into the combustor via an aperture defined in the end cover. Such liquid fuel cartridges may be referred to as “breach-loaded” liquid fuel cartridges.
The liquid cartridge may include a tip portion, an elongated stem, a body, and a flange configured to couple to fuel, air, and water supplies. In at least some known liquid fuel cartridges, the stem includes an outer tube and at least one inner tube section, such that the outer and at least one inner tube sections terminate at the tip portion. The inner tube section channels liquid fuel from a coupling at the cold end of the combustor to the tip, and the outer tube channels water and/or air to the tip. The liquid fuel enters the at least one inner tube section at a temperature that is approximately ambient temperature. However, the outer tube is exposed to combustion temperatures on the order of 800° F. Because liquid fuel at a substantially lower temperature is flowing through the at least one inner tube section during operation of the turbine engine, a substantial temperature differential may exist between the outer tube and the at least one inner tube section. As a result, the outer tube will be prompted to undergo thermal expansion relative to the at least one inner tube section. In order to prevent damage at the tip caused by stresses from the different expansion rates of the inner and outer tubes, in at least some liquid fuel cartridges, the at least one inner tube section is configured to axially slide within the tip.
However, such a liquid fuel tip configuration may result in wear between the tips of the outer tube, and/or the at least one inner tube section due to turbine engine vibration that may result in relative vibratory movements between the outer tube and the at least one inner tube section, at the tip portion, and/or at one or more locations along the stem.
In one aspect, a method for assembling a liquid fuel cartridge for use in a gas turbine engine is provided. The method includes orienting at least one flexible tube section within a housing. The method also includes coupling the at least one flexible tube section to an elongated inner tube section oriented within an elongated outer tube extending from the housing. The method also includes supporting the elongated inner tube section by at least one support member oriented within and coupled to an inner surface of the elongated outer tube, such that the at least one support member substantially precludes transverse movement of the elongated inner tube section within the elongated outer tube, and such that the elongated inner tube section is axially movable relative to the at least one support member.
In another aspect, a gas turbine system is provided. The gas turbine system includes a compressor section, a combustor assembly coupled to the compressor section, and a turbine section coupled to the compressor section, wherein the combustor assembly includes at least one liquid fuel cartridge. The at least one liquid fuel cartridge includes at least one flexible tube section coupled within a housing. The at least one liquid fuel cartridge also includes an elongated inner tube section coupled in fluid communication with the at least one flexible tube section. The elongated inner tube section is oriented within an elongated outer tube extending from the housing. The at least one support member is oriented within and coupled to an inner surface of the elongated outer tube, such that the at least one support member substantially precludes transverse movement of the elongated inner tube section within the elongated outer tube, and such that the elongated inner tube section is axially movable relative to the at least one support member.
In another aspect, a liquid fuel cartridge assembly for use in a combustor is provided. The liquid fuel cartridge assembly includes at least one flexible tube section coupled within a housing. The liquid fuel cartridge assembly also includes an elongated inner tube section coupled in fluid communication with the at least one flexible tube section, the elongated inner tube section oriented within an elongated outer tube extending from the housing. The liquid fuel cartridge assembly also includes at least one support member oriented within and coupled to an inner surface of the elongated outer tube, such that the at least one support member substantially precludes transverse movement of the elongated inner tube section within the elongated outer tube, and such that the elongated inner tube section is axially movable relative to the at least one support member.
As used herein, the terms “axial” and “axially” refer to directions and orientations extending substantially parallel to a longitudinal axis of a combustor. It should also be appreciated that the term “fluid” as used herein includes any medium or material that flows, including, but not limited to, liquid fuel, gaseous fuel, and air.
Air enters turbine system 10 via air intake 24 and is pressurized in compressor 22. The compressed air is mixed with fuel within fuel nozzles 12 for combustion within combustor 16. The combustion generates hot pressurized exhaust gases that drive blades 17 within turbine section 18 to rotate shaft 21 to drive compressor 22 and provide rotational power to load 26. More particularly, rotation of turbine blades 17 causes rotation of shaft 21, such that blades 19 within compressor 22 draw in and pressurize ambient air.
In the exemplary embodiment, fuel nozzle 12 includes a liquid fuel cartridge 40 for use in injecting liquid fuel from a supply of liquid fuel (not shown) into combustor 16. In one embodiment, liquid fuel cartridge 40 is provided so that liquid fuel can be used in combustor 16 as a supplement to a fuel gas supplied to fuel nozzle 12, wherein the fuel gas serves as the primary fuel for combustor 16. In addition, liquid fuel cartridge 40 can supply liquid fuel from a fuel reserve (not shown) that is maintained in the event that a supply of fuel gas (not shown) is interrupted or otherwise unavailable. In an alternative embodiment, combustor 16 may use liquid fuel as the primary fuel, channeled by liquid fuel cartridge 40 to fuel nozzle 12.
A water tube 54 may be oriented outside of, and concentric to, fuel tube 44. In addition, a water cavity 56, located between water tube 54 and fuel tube 44 enables fluid communication of water from a water inlet (not shown) to tip portion 48, to facilitate injection of water into a combustion zone (not shown) within combustor 16 (shown in
As depicted, the air, water, and fuel may flow in a downstream direction 68 toward tip portion 48 for injection through a fuel nozzle (not shown) into combustor 16 (shown in
Tip portion 48 includes an atomizing air tip 70, which is the exterior of tip portion 48. Further, shroud 72 is fixedly secured to atomizing air tip 70 via a joint 74. Joint 74 may couple the two components via any appropriate mechanism sufficient to block fluid flow. For example, joint 74 may include a braze joint directly between shroud 72 and atomizing air tip 70. Brazed joint 74 may provide a seal to prevent bypass flow between air tip 70 and shroud 72. Tip portion 48 may also include a water tip 76 located coaxially inside shroud 72. In the exemplary embodiment, atomizing air tip 70 and water tip 76 are secured by a weld or other durable coupling technique to air tube 58 and water tube 54, respectively. In addition, a fuel tip 78 may be located coaxially inside water tip 76, wherein fuel tip 78 is configured to enable fluid flow and mixing of the liquid fuel flowing in the downstream direction 68 through fuel tip 78. In the exemplary embodiment, tips 70, 76, and/or 78 are not coupled to each other, and so may be capable of movement relative to each other during operation of turbine 10.
In the exemplary embodiment, each tube section 92 and tube section 100 are initially fabricated as a single component, as are tube sections 94 and 98. In an alternative embodiment, tube sections 92 and 94 may be fabricated separately from tube sections 100 and 98, respectively, and subsequently secured together using any suitable coupling method. In the exemplary embodiment, each flexible coiled tube section 92 and 94 may be fabricated from any suitable flexible material that enables cartridge 80 to function as described herein. Moreover, tube sections 92 and 94 may have any cross-sectional configuration, including, but not limited to, a circular cross-sectional configuration, that enables cartridge 80 to function as described herein.
Tube sections 98 and 100 are supported within outer tube 96 by at least two supports 102 coupled to an inside surface of outer tube 96. Supports 102 maintain tube sections 98 and 100 spaced a distance 103 from each other. Supports 102 also maintain tube sections 98 and 100 spaced at least a distance 105 from the inside surface of outer tube 96. More particularly, tube sections 98 and 100 are slidably supported within outer tube 96 by supports 102. Each support 102 may have any configuration that enables cartridge 80 to function as described herein. For example, any number of supports 102 may be provided, that enables cartridge 80, and more specifically, tube sections 98 and 100, to be tuned to address vibrations that may be imposed on tube sections 98 and 100 during operation of turbine system 10. Supports 102 substantially prevent or reduce undesirable transverse vibratory movements of tube sections 98 and 100. In the exemplary embodiment, flange 88 includes at least one aperture 87 through which tube sections 98 and 100 extend to enable tube sections 98 and 100 to be coupled to respective flexible tube sections 94 and 92, such that tube sections 98 and 100 can move axially relative to flange 88.
In the exemplary embodiment, tube sections 98 and 100 terminate at inlet ports (not shown) of tip 86. Tip 86 may have any suitable configuration, including any suitable number and arrangement of apertures 87, that enables tip 86 to discharge a spray of air, fuel, and/or water toward a combustion zone (not shown) within combustor 16 (shown in
During operation of combustor 16 (shown in
In the exemplary embodiment, after liquid fuel combustion is terminated, cartridge 80 is flushed by channeling a flushing fluid, including but not limited to water, through cartridge 80. Flushing of cartridge 80 prevents coking of residual liquid fuel remaining in cartridge 80 during continued operation of combustor 16 (shown in
As described hereinabove with respect to
The exemplary embodiment of
In an alternative embodiment, cartridge 80 may include a single fitting (not shown) that includes two passages coupled in fluid communication, to tube sections 92 and 94, instead of fittings 93 and 95 as shown in
In the exemplary embodiment, each tube section 162 and tube section 168 are initially fabricated as a single component, as are tube sections 170 and 172. In an alternative embodiment, tube sections 162 and 170 may be fabricated separately from tube sections 168 and 172, respectively, and subsequently secured together using any suitable coupling method. In the exemplary embodiment, each flexible coiled tube sections 162 and 170 may be fabricated from any suitable flexible material that enables cartridge 150 to function as described herein. Moreover, tube sections 162 and 170 may have any cross-sectional configuration, including, but not limited to, one of an oval cross-sectional configuration and a rectangular cross-sectional configuration, that enables cartridge 150 to function as described herein. In the exemplary embodiment, tube sections 162 and 170 are coiled about an axis 151 that extends substantially perpendicular to longitudinal axis 161. Accordingly, tube sections 162 and 170 may be referred to as being “laterally” coiled, relative to body 152.
In the exemplary embodiment, stem 154 has a configuration that may be substantially identical to that of stem 84 shown in
In an alternative embodiment, cartridge 150 may include a single fitting (not shown) that includes two passages coupled in fluid communication, to tube sections 162, 170, instead of fittings 158 and 160 as shown in
The invention described herein provides several advantages over known systems and methods for assembling liquid fuel cartridges for use in combustors for gas turbine engines. Specifically, the systems and methods described herein facilitate accommodating differences in thermal expansion between an outer tube of a liquid fuel cartridge and at least one elongated inner tube section oriented within the outer tube. The systems and methods described herein prevent or reduce wear to a tip of a liquid fuel cartridge that may arise from relative axial movement between the outer tube and the at least one elongated inner tube section oriented within the outer tube. In addition, the systems and methods described herein prevent or reduce undesirable transverse vibratory movement of the at least one inner tube section relative to the outer tube. The systems and methods described herein also provide smooth continuous fluid flow paths within the liquid fuel cartridge that facilitate flushing of residual liquid fuel from the cartridge.
Exemplary embodiments of fuel nozzle cartridges and methods for assembling same are described above in detail. The systems and methods are not limited to the specific embodiments described herein, but rather, actions of the methods and/or components of the systems may be utilized independently and separately from other components and/or actions described herein. For example, the systems and methods described herein are not limited to practice only with combustors for gas turbine engines, but also may be used in combination with other devices that incorporate combustors. Moreover, the exemplary embodiment may be implemented and utilized in connection with many other rotary machine applications, other than gas turbines.
The systems and methods are not limited to the specific embodiments described herein, but rather, operations of the methods and/or components of the systems may be utilized independently and separately from other components and/or actions described herein. The method operations described herein are just examples. There may be many variations to the operations described therein without departing from the spirit of the disclosure. For instance, except as specifically described, the actions may be performed in a differing order, or actions may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
This written description uses examples to disclose the systems and methods described herein, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure 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 with insubstantial differences from the literal language of the claims.
While the disclosure has been described in terms of various specific embodiments, those skilled in the art will recognize that the disclosure may be practiced with modification within the spirit and scope of the claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/RU2013/001053 | 11/22/2013 | WO | 00 |
