Patent Application
20180094815
The present invention relates to a damping device for a gas turbine combustor, more particularly, to a liner cap to control damping of the gas turbine combustor. The gas turbine combustor comprises a compressor, a liner, a fuel injector, and a combustion chamber. The compressor provides compressed air through the liner, and the fuel injector supplies the combustion chamber with a fuel gas for combustion. The compressed air and the fuel gas are mixed and provided to the combustion chamber, and then the fuel gas is combusted in the combustion chamber. After the combustion, a hot gas generated in the combustion chamber is supplied to a turbine blade of a turbine. However, the combustion of the fuel gas in the combustion chamber also makes a combustion vibration or an acoustic vibration. The acoustic vibration can make a noise, a crack, or a mechanical stress of the gas turbine combustor.
Damping devices have been disclosed for gas turbine combustors to solve the acoustic vibration problem. For example, the damping systems disclosed in U.S. Pat. No. 5,575,144 and U.S. Pat. No. 5,685,157 provide an external damping device disposed on the outside of the gas turbine combustor and communicating with a case of the gas turbine combustor. However, these damping systems are complex and make the gas turbine combustor bigger.
Exemplary embodiments of the subject invention relate to a gas turbine combustor that substantially obviates one or more of the above disadvantages/problems and provides one or more of the advantages as mentioned below. In many embodiments, a gas turbine combustor comprises a liner cap absorbing an acoustic vibration originating in a combustion chamber.
In one embodiment, a gas turbine combustor includes a first cavity having a first inlet; a second cavity disposed on the first cavity and having a first outlet; and a combustion chamber disposed on the first outlet of the second cavity.
In a further embodiment, the gas turbine combustor includes an impingement plate disposed between the first cavity and the second cavity.
Preferably, the impingement plate includes a plurality of through holes.
In a further embodiment, the gas turbine combustor also includes a liner connected to the first inlet.
Preferably, the liner provides a compressed air to the first inlet.
In a further embodiment, the gas turbine combustor also includes a swirler cup disposed on the first cavity and the second cavity.
In a further embodiment, the gas turbine combustor includes a fuel injector located in the swirler cup.
In a further embodiment, the gas turbine combustor includes a vane located in an inside of the swirler cup and, at an outside of the fuel injector.
Preferablym the vane provides air supplied by the liner and a fuel supplied by the fuel injector to the combustion chamber through the swirler cup.
Preferably, a cooling gas is provided to the first inlet.
In another embodiment, a liner cap comprises a first cavity including a first inlet; a second cavity including a first outlet facing a combustion chamber; and an impingement plate between the first cavity and the second cavity. An air passage may form from the first inlet to the first outlet through the first cavity, the impingement plate, and the second cavity.
Preferably, the first cavity and the second cavity absorb acoustic vibrations generated in the combustion chamber.
Preferably, a volume of the first cavity is larger than a volume of the second cavity.
Preferably, the acoustic vibrations have a plurality of frequency peaks.
Preferably, the first cavity corresponds to the acoustic vibration having a lower, frequency peak of the plurality of frequency peaks and the second cavity corresponds to the acoustic vibration having a higher frequency peak of the plurality of frequency peaks.
Preferably, the impingement plate has a plurality of first through holes, the first outlet has a plurality of second through holes, and each of the first through holes is larger than each of the second through holes.
In a further embodiment the second cavity includes a second outlet facing an outside of the combustion chamber.
In another embodiment, a gas turbine comprises a combustion chamber: a liner adjacent to the combustion chamber; a liner cap capping the combustion chamber: and a swirler cup passing through the liner cap. The liner cap includes a first cavity having a closed plate and an open plate opposite to the closed plate and a second cavity disposed between the open plate of the first cavity and the combustion chamber.
In a further embodiment, the gas turbine further comprises a turbine blade configured to receive a hot gas from the combustion chamber and a case encapsulating the liner cap and the swirler cup.
Preferably, the liner provides a first portion of air to the first cavity and a second portion of air to the swirler cup.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Patent Office upon request and payment of the necessary fee.
When the term “on” or “over” are used herein, when referring to layers, regions, patterns, or structures, it is understood that the layer, region pattern, or structure can be directly on another layer or structure, or intervening layers, regions, patterns, or structures may also be present. When the terms “under” or “below” are used herein, when referring to layers, regions, patterns, or structures, it is understood that the layer, region, pattern, or structure can be directly under the other layer or structure, or intervening layers, regions, patterns, or structures may also be present.
In addition, references to “first”, “second”, and the like (e.g., first and second portion), as used herein, and unless otherwise specifically stated, are intended to identify a particular feature of which there may be more than one. Such reference to “first” does not imply that there must be two or more. These references are not intended to confer any order in time, structural orientation, or sidedness (e.g., left or right) with respect to a particular feature, unless explicitly stated. In addition, the terms “first” and “second” can be selectively or exchangeably used for the members.
Furthermore, “exemplary” is merely meant to mean an example, rather than the best. It is also to be appreciated that features, layers and/or elements depicted herein are illustrated with particular dimensions and/or orientations relative to one another for purposes of simplicity and ease of understanding, and that the actual dimensions and/or orientations may differ substantially from that illustrated. That is, a dimension of each of the elements may be exaggerated for clarity of illustration, and the dimension of each of the elements may be different from an actual dimension of each of the elements. Not all elements illustrated in the drawings must be included and limited to the present disclosure, but the elements except essential features of the present disclosure may be added or deleted.
It is to be understood that the figures and descriptions of embodiments of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that may be well known. Those of ordinary skill in the art will recognize that other elements may be desirable and/or required in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein.
Now, the gas turbine combustor according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The liner 300 is disposed adjacent to the combustion chamber 200 and provides a compressed air. The majority of the compressed air provided by the liner 300 is supplied into the inner side of the case 500 and then flows into the combustion chamber 200 through the vane 800 and the swirler cup 600.
The fuel injector 700 provides a fuel to the combustion chamber 200 through the vane 800 and the swirler cup 600. That is, the compressed air provided by the liner 300 and the fuel provided by the fuel injector 700 are mixed by the vane 800 and provided to the combustion chamber 200 through the swirler cup 600.
The ignitor 900 ignites the fuel mixed with the compressed air in the combustion chamber 200. According to the ignition of the ignitor 900, the combustion occurs in the combustion chamber 200, and then a hot gas is generated in the combustion chamber 200. However, in addition to the intended combustion, an acoustic vibration also results as a by-product of the combustion. The resulting acoustic vibration may have multiple frequency peaks.
A portion of the compressed air provided by the liner 300 is supplied into the liner cap 400 and flows into the combustion chamber 200 through the liner cap 400. This compressed air exiting from the liner cap 400 inhibits the hot gas made by the combustion from making contact with the liner cap 400 by pushing the hot gas away from the liner cap 400. As a result, the hot gas is supplied from the combustion chamber 200 to a turbine blade (not shown) of a gas turbine and used to turn the turbine blade. While the compressed air flows through the liner cap 400, the liner cap 400 absorbs the acoustic vibration and functions as a damping device that reduces or eliminates the acoustic vibration. In certain embodiment, the liner cap 400 may not receive the compressed air from the liner 300, but may receive air from another source. The compressed air from the liner 300 or the air from another source may be a cooling air.
The liner cap 400 has a cylinder shape and caps a top portion of the combustion chamber 200. A plurality of swirler cups 600 having a cylinder shape pass through the liner cap 400. The number of swirler cups 600 in the gas turbine combustor 100 of the subject invention can be seven, though embodiments are not limited thereto.
The second cavity 450 includes a first outlet 460 that faces the combustion chamber 200 and that includes a plurality of second through holes 465. The second cavity 450 receives the compressed air from the first cavity 420 and supplies the compressed air to the combustion chamber 200 through the second through holes 465 of the first outlet 460. Each of the second through holes 465 of the first outlet 460 is smaller than each of the first through holes 440 of the impingement plate 430. However, the number of the second through holes 465 of the first outlet 460 is larger than the number of the first through holes 440 of the impingement plate 430. In addition, the second cavity 450 further includes a second outlet 470 that is connected to the outside of the combustion chamber 200. That is, a portion of the compressed air in the second cavity 450 may exit to the outside of the combustion chamber 200. The second outlet 470 includes a plurality of third through holes 475, and the size of each of the third through holes 475 is smaller than the size of the first through holes 440 of the impingement plate 430, but larger than the size of the second through holes 465 of the first outlet 460. The number and the size of the through holes are not limited and may be different.
A volume of the first cavity 420 is larger than a volume of the second cavity 450. The first cavity 420 absorbs an acoustic vibration having a lower frequency peak, for example, below 1000 Hz, and the second cavity 450 absorbs an acoustic vibration having a higher frequency peak, for example, over 1000 Hz. However, these volume sizes and frequency peaks of the first cavity 420 and, the second cavity 450 are not limited and may have different volumes and different frequency peaks. The volumes of the first cavity 420 and the second cavity 450 can be easily controlled by moving the impingement plate 430 back and forth.
In the first embodiment of the subject invention, the liner cap 400 incorporates a damping device that reduces or eliminates an acoustic vibration by forming the first cavity 420 and the second cavity 450 in an inner side of the liner cap 400. That is, the gas turbine combustor 100 can include the damping device that is accomplished in the liner cap 400 without increasing a volume of the gas turbine combustor.
A greater understanding of the present invention and of its many advantages may be had from the following example, given by way of illustration. The following example is illustrative of some of the methods, applications, embodiments, and variants of the present invention. It is, of course, not to be considered as limiting the invention. Numerous changes and modifications can be made with respect to the invention.
A gas turbine combustor according to an embodiment of the subject invention comprises a combustion chamber, a liner adjacent to the combustion chamber, a liner cap capping the combustion chamber, and a swirler cup passing through the liner cap, wherein the liner cap includes a first cavity having a first inlet, a second cavity having a first outlet facing the combustion chamber and a second outlet facing an outside of the combustion chamber, and an impingement plate between the first cavity and the second cavity. A longitudinal cross-sectional diagram of the gas turbine combustor of the subject invention is shown in
The volume of the first cavity is 13,470,789 mm3 and the volume of the second cavity is 1,579,933 mm3. The first inlet of the first cavity has six holes, wherein each of the holes has a diameter of 20 mm. The impingement plate has 30 first through holes, wherein each of the first through holes has a diameter of 10 mm. The first outlet of the second cavity facing the combustion chamber has 3940 second through holes, wherein each of the second through holes has a diameter of 0.8 mm. The second outlet of the second cavity facing the outside of the combustion chamber has 60 third through holes, wherein each of the third through holes has a diameter of 5 mm.
Normalized Impedance of the liner cap according to the embodiment of the subject invention is shown in
It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included, within the spirit and purview of this application. Thus, the invention is not intended to limit the examples described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
