Patent Application
20120047895
This present application relates generally to systems and/or apparatus for improving the efficiency and/or operation of turbine engines and/or industrial machinery, which, as used herein and unless specifically stated otherwise, is meant to include all types of combustion turbine or rotary engines, including gas turbine engines, aircraft engines, and others. More specifically, but not by way of limitation, the present application relates to methods, systems, and/or apparatus pertaining to combustor cooling and operation in gas turbine engines.
During operation of a gas turbine engine, combustion of fuel and compressed air mixture occurs inside a combustor. To prevent damage to the turbine or other parts of the gas turbine engine, the combustion process is stabilized to contain the process inside the combustor. Typically, a venturi is provided inside a combustion chamber of the combustor. A venturi substantially stabilizes the combustion process and prevents the flame from flashing backwards into other parts of the turbine engine. Further, various components of the combustor, especially walls of the combustion chamber and the venturi, require cooling to prevent damage and also, to increase the life of the components.
Over the years, different methods and systems have been used to provide cooling to various components of the combustor. This may include a liner, which circumferentially surrounds the combustion chamber and accepts a flow of a coolant. The coolant flowing through the liner may only provide surface cooling to the combustion chamber and the venturi. However, surface cooling may not be effective in cooling the combustion chamber and the venturi, which results in a reduced life for the combustor. Further, the coolant flowing through the liner may substantially include compressed air diverted from a compressor of the gas turbine engine. The compressed air, after performing the cooling operation, is discarded in an aft portion of the liner, which may reduce an efficiency of the gas turbine engine. Moreover, the venturi used in this type of cooling configuration may include more number of components and thus, involves a complicated construction.
Further, to reduce wastage of compressed air from the compressor, the compressed air may be introduced inside the combustion chamber, after performing cooling. However, such a configuration may further complicate the construction of the venturi and/or the combustion chamber and only provide a surface cooling of the parts of the combustor.
As a result, there is a need for improved systems and apparatus relating to the more efficient and cost effective cooling of the combustors in a gas turbine engines.
The present application, thus, describes a venturi for use in a combustor of a gas turbine engine, the venturi comprising two non-integrally formed pieces: a forward piece and an aft piece; wherein: the forward piece comprises a forward axial extension, a converging wall section, and a diverging outer-wall section; the aft piece comprises an aft axial extension and a diverging inner-wall section; and the forward piece and the aft piece are configured such that the diverging inner-wall section resides in close, spaced relation to the diverging outer-wall section such that a circumferentially extending cooling slot is formed therebetween.
The present application further describes a combustor for a gas turbine engine that includes first and second combustion chambers interconnected by a throat region that includes a converging wall section, a diverging wall section, and a throat apex between the diverging wall section and the converging wall section; a plurality of cooling apertures disposed on the converging wall section; and a cooling slot disposed on the diverging wall section; wherein: the cooling apertures comprise apertures through the thickness of the converging wall section; and the cooling slot comprising a circumferentially extending slot through the length of the diverging wall section.
These and other features of the present application will become apparent upon review of the following detailed description of the preferred embodiments when taken in conjunction with the drawings and the appended claims.
These and other features of this invention will be more completely understood and appreciated by careful study of the following more detailed description of exemplary embodiments of the invention taken in conjunction with the accompanying drawings, in which:
As an initial matter, to communicate clearly the invention of the current application, it may be necessary to select terminology that refers to and describes certain parts or machine components of a combustion turbine engine. Whenever possible, common industry terminology will be used and employed in a manner consistent with its accepted meaning. However, it is meant that any such terminology be given a broad meaning and not narrowly construed such that the meaning intended herein and the scope of the appended claims is unreasonably restricted. Those of ordinary skill in the art will appreciate that often a particular component may be referred to using several different terms. In addition, what may be described herein as a single part may include and be referenced in another context as consisting of several component parts, or, what may be described herein as including multiple component parts may be fashioned into and, in some cases, referred to as a single part. As such, in understanding the scope of the invention described herein, attention should not only be paid to the terminology and description provided, but also to the structure, configuration, function, and/or usage of the component, as provided herein.
In addition, several descriptive terms may be used regularly herein, and it may be helpful to define these terms. These terms and their definitions, as used herein, are as follows. As used herein, “downstream” and “upstream” are terms that indicate a direction relative to the flow of a working fluid through the turbine. As such, the term “downstream” refers to a direction that generally corresponds to the direction of the flow of the working fluid, and the term “upstream” generally refers to the direction that is opposite of the direction of flow of the working fluid. The terms “forward” and “aft”, without any further specificity, refer to directions, with “forward” referring to the forward or compressor end of the engine and “aft” referring to the aft or turbine end of the engine. The term “radial” refers to movement or position perpendicular to an axis. It is often required to describe parts that are at differing radial positions with regard to an axis. In this case, if a first component resides closer to the axis than a second component, it may be stated herein that the first component is “radially inward” or “inboard” of the second component. If, on the other hand, the first component resides further from the axis than the second component, it may be stated herein that the first component is “radially outward” or “outboard” of the second component. The term “axial” refers to movement or position parallel to an axis. Finally, the term “circumferential” refers to movement or position around an axis.
Referring now to the figures, where the various numbers represent like parts throughout the several views,
Further, the coolant may include coolant air that is diverted from combustor air, which is compressed in a compressor (not shown) and utilized for combustion. Thus, coolant air, which may form a significant part of combustor air, also reduces an efficiency of the gas turbine engine. Moreover, the venturi 102 may also include a large number of components and thus, involves a complicated construction because of the inner and outer venturi portions 106 and 108.
The combustor 200 may include an inlet (not shown) for the entry of the combustor air and fuel mixture into a combustion chamber 208. In various embodiments of the present application, the combustor 200 may include one or more inlets. One or more ignition means (E.g. spark plugs) may be provided in the combustion chamber 208 to ignite the combustor air and fuel mixture. Subsequent to ignition, combustion products may exit the combustor 200 to a turbine (not shown). A venturi 210 may be provided inside the combustion chamber 208 to substantially stabilize in order to contain the ignition of the combustor air and fuel mixture inside the combustor 200. In an embodiment of the present application, a divergence step 211 may be provided downstream of the venturi 210 to substantially mitigate a screech of the combustor air and fuel mixture. As shown, the venturi 210 may substantially divide the combustion chamber into a first stage combustion chamber 212 and a second stage combustion chamber 214.
Further, a flow sleeve 216 may be provided to form a coolant plenum 218 between the flow sleeve 216 and a combustion chamber wall 220. The coolant plenum 218 may be disposed circumferentially around the combustor chamber 208. In an embodiment of the present application, the coolant plenum 218 may be configured to receive a flow of pressurized coolant through a flow sleeve inlet 222. In an embodiment of the present application, the pressurized coolant may be pressurized air diverted from the compressor. In another embodiment of the present application, the pressurized coolant may be pressurized air mixed with water, steam or inert gas. The pressurized coolant may flow through the coolant plenum 218 and exit the coolant plenum 218 through a flow sleeve outlet 224. Those of ordinary skill in the art will appreciate that the pressurized coolant may also flow in a direction opposite to the direction illustrated in
As illustrated in
As illustrated in
In an embodiment of the present application, the cooling slot 316 may include a mouth 340, which is defined between the end 332 of the outer-wall section 310 and a section of the aft piece 304 where the aft axial extension 312 transitions to the diverging inner-wall section 314. Such a section of the aft piece 304 may be proximate to the forward end 334 of the aft axial extension 312. In an embodiment of the present application, the cooling slot 316 may include an outlet 342 defined between the end 338 of the diverging inner-wall section 314 of the aft piece 304 and the throat apex 330 of the forward piece 302. In various embodiments of the present application, at least one of the sections of the forward piece 302 or the aft piece 304 where the forward axial extension 306 or the aft axial extension 312 transitions to the converging wall section 308 or the diverging inner wall section 314 may be chamfered or filleted.
As illustrated in
In an embodiment of the present application, the cooling apertures 348 may be configured such that each of the cooling apertures 348 is approximately perpendicular to the inner face 344 and the outer face 346 of the converging wall section 308. In an alternative embodiment of the present application, the cooling apertures 348 may be obliquely oriented with respect to the inner face 344 and the outer face 346 of the converging wall section 308. In an embodiment of the present application, the cooling apertures 348 on the converging wall section 308 may be arranged in multiple circumferentially extending rows. However, the cooling apertures 348 on the converging wall section 308 may be arranged in any other configuration (E.g. staggered) without deviating from the scope of the present application.
In an embodiment of the present application, the cooling apertures 348 may be configured such that each of the cooling apertures 348 is approximately perpendicular to the inner face 344 and the outer face 346 of the converging wall section 308. In an alternative embodiment of the present application, the cooling apertures 348 may be tilted with respect to the centerline A-A shown in
In an embodiment of the present application, the cooling apertures 502 may be configured such that each of the cooling apertures 502 is approximately perpendicular to the inner face 324 and the outer face 322 of the diverging inner-wall section 314. In an alternative embodiment of the present application, the cooling apertures 502 may be tilted with respect to the centerline A-A shown in
In an embodiment of the present application, the cooling apertures 502 may be configured such that each of the cooling apertures 502 is approximately perpendicular to the inner face 324 and the outer face 322 of the diverging inner-wall section 314. In an alternative embodiment of the present application, the cooling apertures 502 may be obliquely oriented with respect to the inner face 324 and the outer face 322 of the diverging inner-wall section 314. In an embodiment of the present application, the cooling apertures 502 on the diverging inner-wall section 314 may be arranged in multiple circumferentially extending rows. However, the cooling apertures 502 on the diverging inner-wall section 314 may be arranged in any other configuration (E.g. staggered) without deviating from the scope of the present application.
As one of ordinary skill in the art will appreciate, the many varying features and configurations described above in relation to the several exemplary embodiments may be further selectively applied to form the other possible embodiments of the present invention. For the sake of brevity and taking into account the abilities of one of ordinary skill in the art, all of the possible iterations is not provided or discussed in detail, though all combinations and possible embodiments embraced by the several claims below or otherwise are intended to be part of the instant application. In addition, from the above description of several exemplary embodiments of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are also intended to be covered by the appended claims. Further, it should be apparent that the foregoing relates only to the described embodiments of the present application and that numerous changes and modifications may be made herein without departing from the spirit and scope of the application as defined by the following claims and the equivalents thereof.
