Patent Application
20050223707
The present invention relates to a gas turbine combustor (sometimes referred as a “combustor” hereinafter) and a gas turbine equipped with a gas turbine combustor, and especially, relates to a gas turbine combustor and a gas turbine that reduce combustion vibration in order to realize decrease in nitrogen oxides (NOx).
Conventionally, a gas turbine has an air compressor (sometimes referred as a “compressor” hereinafter), a combustor and a turbine serve as major components, wherein the combustor is installed between the compressor and the turbine that are directly connected to each other by a main shaft; an air serving as a working fluid is inhaled into the compressor by rotation of the main shaft and compressed therein; the compressed air is introduced into the combustor and burned with a fuel; and the high temperature and high pressure combustion gas is exhausted into a turbine so as to rotary-drive the main shaft with the turbine. The gas turbine constructed in such a manner is utilized as a driving source by having a generator and the like connected to the front end of the main shaft, and is also utilized as a jet engine by installing an exhaust port for injection of combustion gas at the front of the turbine.
And now, in recent years, especially reduction of NOx in exhaust gas being discharged from a gas turbine is strongly desired for an environmental issue as one of vital legal regulations. Therefore, a combustor which actually generates NOx especially requires a technology to suppress generation of NOx. In order to achieve this, as a combustion method to be adopted to a combustor, a premixed combustion method has become a main stream, wherein a fuel and compressed air are burned after being mixed preliminarily. In this premixed combustion method, because a fuel disperses uniformly and tenuously in the compressed air, local increase in temperature of combustion flame can be prevented, thereby making it possible to reduce the generation amount of NOx which increases in accordance with an increase in temperature of combustion flame.
Here, a more common gas turbine than conventional to which a combustor using a premixed combustion method is applied will be described by referring to
Being constructed as mentioned above, compressed air being compressed in the compressor 2 flows into the casing 5 (an outline arrow in the drawing), reverses for approximately 180 degrees (arrows in solid line in the drawing) after going through a tubular space which is formed by an outer circumference surface of the combustor basket 6 and an inner circumference surface of an outer shell 8, and is introduced into the combustor basket 6 from the rear-end side. Next, a fuel is blasted to the pilot burner (not illustrated) at the front end of the pilot nozzle 9 and be subject to diffusion combustion and is also subject to premixed combustion by being mixed with a fuel injected to the main burner (not illustrated) at the front end of each of the main nozzles 10, so as to become high temperature and high pressure combustion gas. The combustion gas goes through the internal of the transition piece 7 and is exhausted from the front end thereof, so as to drive the turbine 4. In addition, a part of compressed air (sometimes referred as “bypass air” hereinafter) inside the casing 5 is supplied to the internal of the transition piece 7 from the bypass duct 11, which plays a role of adjusting the density of combustion gas.
However, although the above-mentioned pre-mixed combustion method seemingly excels in reduction of NOx, it has a problem that combustion vibration is easy to occur because flame is thin and burns in a narrow region in a short time, resulting in an excessive combustion energy per unit space. This combustion vibration is generated by having a part of combustion energy converted into vibrational energy, and not only produces significant vibration and noise when it propagates as a pressure wave and resonates with an acoustical system consisting of casings of a combustor, a gas turbine and the like but also induces pressure fluctuation and heat-generation fluctuation inside the combustor, thereby making state of combustion unstable, which eventually interferes a decrease in NOx.
In order to cope with such a problem of combustion vibration as mentioned above, conventionally, by actually operating a gas turbine, appropriate adjustment is made so as to operate it in a normal condition and, at the same time, regular operational conditions are set as needed. Therefore, cumbersome adjustment activities are indispensable.
Additionally, a conventional combustor trying to reduce the combustion vibration has a resonator having a cavity installed around the outer circumference of a combustor basket and a transition piece which serve as cylinder bodies having a combustion region therein, and has sound-absorption holes opening to the cavity formed therein. (See FIG. 1 through FIG. 3 on pages 3 through 5 of the Japanese Patent Application Laid Open No. 2002-174427, for example.) By this combustor, fluid particles serving as vibration elements of the combustion vibration that occurs in the combustion region resonate with the air in the cavity inside the resonator and vibrate through the sound-absorption holes, damping the vibration amplitude thereof. In this way, it is possible to reduce the combustion vibration, thereby realizing more or less a decrease in NOx.
However, in the conventional combustor trying to reduce the combustion vibration as mentioned above, it is originally assumed that the combustion vibration occurs in a high-frequency area. Therefore, it is effective to the combustion vibration in a high-frequency area, but at the same time, it cannot be said to thoroughly cope with the combustion vibration in a low-frequency area.
It is an object of the present invention to provide a gas turbine combustor and a gas turbine that can reduce the combustion vibration in order to realize a decrease in NOx in a stable manner. Furthermore, it is another object to provide a gas turbine combustor and a gas turbine that can reduce the combustion vibration, irrespective of the frequency areas.
In order to achieve the above-mentioned object, a gas turbine combustor according to the present invention, comprising a cylinder body which has a combustion region therein, is provided with a first box body which is installed outside the cylinder body, forming a first internal space having a predetermined capacity; and a first throat having a predetermined length which has one end thereof open to the combustion region or a downstream area thereof and has the other end thereof open to the first internal space; and has a first resistive element having a multiple number of through-holes inserted and engaged into the one end of the first throat. By this, fluid particles serving as vibration elements of the combustion vibration that occurs in the combustion region are effectively trapped by the first resistive element; resonate with the air in the first internal space being connected through the first throat; and vibrate in the neighborhood of the first resistive element, damping the vibration amplitude thereof. In this way, it is possible to reduce the combustion vibration and realize a stable decrease in NOx. Here, the object to which one end of the first throat opens is a combustor basket or a transition piece which makes up the cylinder body or a bypass duct which is connected to a side wall of the cylinder body.
Additionally, in order to achieve the above-mentioned object, according to the present invention, a gas turbine combustor, comprising a cylinder body which has a combustion region therein, is provided with a box body which is installed outside the cylinder body, forming an internal space having a predetermined capacity; and a throat having a predetermined length which has one end thereof open to an area upstream of the combustion region and has the other end thereof open to the internal space; and has a resistive element having a multiple number of through-holes inserted and engaged into the one end of the throat. By this, fluid particles serving as vibration elements of the combustion vibration that occurs in a combustion region are effectively trapped by the resistive element; resonate with the air in the internal space of the box body being connected through the throat; and vibrate in the neighborhood of the resistive element, damping the vibration amplitude thereof. In this way, it is possible to reduce the combustion vibration and realize a stable decrease in NOx. Here, the object to which one end of the throat opens is a combustor basket which makes up the cylinder body or an outer shell which is installed so as to be concentric with the combustor basket.
In addition, in order to achieve the above-mentioned object, according to the present invention, a gas turbine is equipped with an air compressor and a turbine being directly connected to each other by a main shaft and a plurality of gas turbine combustors being installed on the same circumference of the main shaft between the air compressor and the turbine and consisting of a cylinder body each of which has a combustion region therein; wherein, are provided a first annulus pipe body which is installed outside the rear end of each of the cylinder bodies concentrically with the main shaft and a first throat having a predetermined length which has each of one ends open to an area upstream of each of the combustion regions and has each of the other ends open to the inside of the first annulus pipe body; and wherein, a first resistive element having a multiple number of through-holes is inserted and engaged into each of the one ends of each of the first throats. By this, fluid particles are effectively trapped by each of the first resistive element; resonate with the air inside the first annulus pipe body being connected through each of the first throats; and vibrate in the neighborhood of each of the first resistive elements, damping the vibration amplitude thereof. In this way, it is possible to reduce the combustion vibration and eventually realize a stable decrease in NOx as an entire gas turbine, thereby achieving a reduction of NOx in exhaust gas. Here, the object to which each of the ends of each of the first throats opens is each of combustor baskets which makes up each of the cylinder bodies or each of outer shells which is installed concentrically with each of the combustor baskets.
Furthermore, in order to achieve the above-mentioned object, according to the present invention, a gas turbine combustor, comprising a cylinder body which has a combustion region therein and a bypass duct which has one end open to the combustion region or a downstream area thereof in the cylinder body and has the other end open to the internal of a casing forming the periphery of the cylinder body; wherein, is installed a plate-type member which has a multiple number of through-holes and crosses the bypass duct. By this, fluid particles serving as vibration elements of the combustion vibration that occurs in a combustion region are introduced from one end of the bypass duct and effectively trapped in each of the through-holes of the plate-type member; resonate with the air inside the casing being connected through the bypass duct; and vibrate through each of the through-holes, damping the vibration amplitude thereof. In this way, it is possible to reduce the combustion vibration and realize a stable decrease in NOx.
Moreover, in order to achieve the above-mentioned object, according to the present invention, a gas turbine combustor, comprising a cylinder body which has a combustion region therein and a bypass duct which has one end open to the combustion region or a downstream area thereof in the cylinder body and has the other end open to the internal of a casing forming the periphery of the cylinder body; wherein, are provided a dividing wall which crosses in the neighborhood of the one end of the bypass duct, a protruding pipe which goes through this dividing wall and protrudes from at least one surface of the dividing wall, and a resistive element which is inserted and engaged into this protruding pipe and has a multiple number of through-holes. By this, fluid particles are effectively trapped by the resistive element; resonate with the air in a space from the dividing wall inside the bypass duct being connected through the protruding pipe to the other end; and vibrate in the neighborhood of the resistive element, damping the vibration amplitude thereof. In this way, it is possible to reduce the combustion vibration and realize a stable decrease in NOx.
Furthermore, in order to achieve the above-mentioned object, according to the present invention, a gas turbine is equipped with an air compressor, any of the above-mentioned gas turbines and a turbine. Therefore, it is possible to reduce the combustion vibration in a gas turbine combustor and realize a stable decrease in NOx, thereby achieving a reduction of NOx in exhaust gas.
And, in order to achieve the above-mentioned object further, according to the present invention, a gas turbine combustor, comprising a cylinder body having a combustion region therein; wherein, the cylinder body has a resonator having a cavity installed around the outer circumference thereof; has sound-absorption holes opening to the cavity formed therein; and is provided with a first box body which is installed so as to be adjacent to the resonator, forming a first internal space having a predetermined capacity, and a first throat which has one end thereof open to the cavity and has the other end thereof open to the first internal space. By this, fluid particles serving as vibration elements in a high-frequency area of the combustion vibration that occurs in a combustion region resonate with the air in a cavity inside the resonator and vibrate through the sound-absorption holes, damping the vibration amplitude thereof. On the other hand, fluid particles serving as vibration elements in a low-frequency area resonate with the air in a first internal space being connected through a first throat through the cavity inside the resonator and vibrate through the sound-absorption holes, damping the vibration amplitude thereof. In this way, it is possible to reduce the combustion vibration, regardless of frequency areas, and realize a stable decrease in NOx.
Then, in order to achieve the above-mentioned object further, according to the present invention, a gas turbine is provided with an air compressor, the above-mentioned gas turbine combustor and a turbine. Therefore, it is possible to reduce the combustion vibration in a gas turbine combustor, regardless of frequency areas, and realize a stable decrease in NOx, thereby achieving a reduction of NOx in exhaust gas.
Referring now to the drawings, embodiments of the present invention will be described hereinafter. First a first through eighth embodiments of the present invention will be explained in sequence.
A combustor 3 in accordance with a first embodiment of the present invention is applied to a gas turbine 1 shown in
Further, a first resistive element 33 having a multiple number of through-holes is inserted and engaged into one end 32a of the first throat 32. The first resistive element 33 is, for example, a punching metal, a ceramic sintered metal or a sintered metallic mesh. In addition, the object body 20 mentioned herein is a cylinder body such as the combustor basket 6 having a combustion region therein or the transition piece 7 in an area downstream thereof, or the bypass duct 11 being connected to the side walls thereof and is an object whose inside has combustion vibration propagate.
Constructed as described above, the first box body 30 functions as an air-container body which accommodates the air for resonance for fluid particles serving as vibration elements of the combustion vibration that occurs in a combustion region inside the combustor basket 6. Additionally, the first throat 32 functions as a junction body which connects the object body 20 and the first box body 30. Moreover, the first resistive element 33 functions as a transverse body which crosses inside the first throat 32, and through-holes thereof function as vents where fluid particles are vibrated by resonance with the air inside the first box body 30. In this way, as for the combustion vibration that occurs in a combustion region inside the combustor basket 6, fluid particles serving as vibration elements thereof are effectively trapped by the first resistive element 33 by propagating inside the object body 20; and then resonate with the air in a first internal space 31 being connected through the first throat 32 and vibrate in the neighborhood of the first resistive element 33. By this vibration, vibration amplitude of the fluid particles is damped and the combustion vibration thereof is reduced. As a result, a stable reduction of NOx is realized.
Additionally, in
Then, a second embodiment of the present invention will be described by referring to
Consequently, in accordance with this embodiment, such a stepped tubular object is applied as the first throat 32 as an inner circumference thereof is rapidly spread from one end 32b to the other end 32a in the neighborhood of the center, wherein an opening area of one end 32a thereof is larger than that of the other end 32b. The first resistive element 33 is inserted and engaged into one end 32a.
Because in this way, it is possible to make an internal of the first throat 32, namely the cross-sectional area of the other end 32b, smaller and at the same time, expand a region where the first resistive element 33 exists, the ratio of trapping of fluid particles in a low-frequency area is increased, thereby contributing to a reduction of combustion vibration sufficiently as a whole. As a result, it is possible to reduce thoroughly the combustion vibration in a low-frequency area as a whole.
Additionally, when a trumpet-like object whose inner circumference gradually expands is applied as the first throat 32, the same effects can be obtained.
Next, a third embodiment of the present invention will be described by referring to
Therefore, in this embodiment, the first throat 32 has a resistive element 34 having a multiple number of through-holes inserted and engaged into the other end 32b thereof. Same as the first resistive element 33, the resistive element 34 is, for example, a punching metal, ceramic sintered metal or sintered metallic mesh.
Constructed as described above, a phase difference occurs for each of pressure fluctuations (“−”and “+” in the drawing) between the first internal space 31 and the space inside the first throat 32. Therefore, by utilizing this, fluid particles vibrate effectively in the neighborhood of the resistive element 34. As a result, although vibration of fluid particles in the neighborhood of the first resistive element 33 is insufficient, combustion vibration in a low-frequency area can be reduced sufficiently.
Additionally, when the resistive element 34 is placed in either position of one end 32b having a smaller cross-sectional area than the other end 32a in the first throat 32, same effects can be obtained.
Next, a fourth embodiment of the present invention will be described by referring to
Namely, in accordance with the relevant embodiment, one end 32b of the first throat 32 protrudes into the first internal space 31, and a multiple number of through-holes 35 are formed in this protruding portion. Constructed in this manner, because fluid particles vibrate effectively in each of through-holes 35 by same action as the resistive element 34 in the third embodiment, combustion vibration in a low-frequency area can be thoroughly reduced in the same manner as the third embodiment.
Next, a fifth embodiment of the present invention will be described by referring to
By this, an area where the first resistive element 33 exists can be expanded as a whole. As a result, a ratio of trapping of fluid particles in a low-frequency area is increased, thereby making it possible to reduce combustion vibration in a low-frequency area more sufficiently as a whole.
Here, in
Next, a sixth embodiment of the present invention will be described by referring to
Therefore, in accordance with the relevant embodiment, a resistive element 36 having a multiple number of through-holes is installed to at least one of each of first internal spaces 31. Same as the first resistive element 33 and the resistive element 34, the resistive element 36 is, for example, a punching metal, ceramic sintered metal or a sintered metallic mesh.
Constructed as described above, because fluid particles vibrate in the neighborhood of the resistive element 36 due to a phase difference of pressure fluctuation being caused by a first internal space 31 itself, combustion vibration in a high-frequency area can be reduced.
Next, a seventh embodiment of the present invention will be described by referring to
In other words, in accordance with the relevant embodiment, a protruding plate 37 having a multiple number of through-holes is installed, protruding through each of first internal spaces 31 so as to form a connecting passageway from an end 32b of the first throat 32. Constructed as this, because fluid particles effectively vibrate in each of through-holes of the protruding plate 37 due to same action of the resistive element 36 in accordance with the sixth embodiment, combustion vibration in a high-frequency area can thoroughly be reduced.
Next, an eighth embodiment of the present invention will be described by referring to
To put simply, in accordance with the relevant embodiment, outside the first box body 30, is installed in a row a second box body 40 being similar to the first box body 30, and by a cavity inside the second box body 40, is formed a second internal space 41 having a predetermined capacity. Additionally, the second box body 40 is connected to the first box body 30 through a second throat 42 in a tubular form having a predetermined length in a same manner as the first throat 32, and the second throat 42 has one end 42a located on a side of the first box body 30 open to a first internal space 31 and has the other end 42b located on a side of the second box body 40 open to a second internal space 41.
Moreover, a second resistive element 43 having a multiple number of through-holes is inserted and engaged into one end 42a of the second throat 42. Same as the first resistive element 33, the second resistive element 43 is, for example, a punching metal, ceramic sintered metal or a sintered metallic mesh.
By this, fluid particles not only vibrate in the neighborhood of the first resistive element 33 but also resonate with the air in each of second internal spaces 41 being connected through each of second throats 42 and vibrate in the neighborhood of each of second resistive elements 42, thereby damping the vibration amplitude thereof. As a result, it is possible to make fluid particles vibrate in a multiple number of places and consequently, combustion vibration can be reduced efficiently.
Additionally, in
Additionally, same as the concept of the second through fifth embodiments of the present invention, the following deformation may be possible, considering more sufficient response to combustion vibration in a low-frequency area. Following the first throat 32 in accordance with the second embodiment, one end 42a of the second throat 42 has a larger opening area than the other end 42b. Following the resistive element 34 of the first throat 32 in accordance with the third embodiment, a resistive element having a multiple number of through-holes is inserted and engaged into the other end 42b of the second throat 42. Following the first throat 32 in accordance with the fourth embodiment, the other end 42b of the second throat 42 protrudes through the second internal space 41 and a multiple number of through-holes are formed in this protruding portion. Following the first box bodies 30 and the like in accordance with the fifth embodiment, a plurality of second box bodies 40 and the like are installed in a parallel, and at least one of the opening area or the length of each of ends 42b of a second throat 42 and the capacity of each of second internal spaces 41 is mutually different for every second box body 40.
Furthermore, same as the concept of the sixth and seventh embodiments, the following deformation may be possible, considering more sufficient response to combustion vibration in a high-frequency area. Following the resistive element 36 in accordance with the sixth embodiment, at least one of each of second internal spaces 41 has a resistive element having a multiple number of through-holes installed. Following the protruding plate 37 in accordance with the seventh embodiment, at least one of second box bodies 40 has a protruding plate having a multiple number of through-holes installed, protruding through each of second internal spaces 41 and forming a continuous passageway from an end 42b of the second throat 42.
Now, basic concepts of the present invention are explained as above, based on the first through eighth embodiments, and by referring to the drawings, an example of a gas turbine to which these concepts are applied concretely will be described.
As shown in
Additionally, three first throats 32 protruding from the side wall 11a are installed at regular intervals for same degrees in the first internal space 31. Each of ends 32a of these first throats 32 opens to the internal of the bypass duct 11 from the side wall 11a while each of the other ends 32b opens to the first internal space 31. Further, each of ends 32a of each of first throats 32 has a first resistive element 33 having a multiple number of through-holes inserted and engaged.
In other words, construction shown in
The reasons why a bypass duct 11 is adopted as an object body 20 here are that in order to reduce combustion vibration effectively, a certain size is necessary for a first internal space 31 and a certain length is necessary for a first throat 32 and that an area in the neighborhood of the bypass duct 11 having a rather sufficient room is suitable. In consequence, there are advantages that it is easy to install a first box body 30, being installed in order to form a first internal space 31, and a first throat 32, and that it is possible to sufficiently secure a first internal space 31 having a certain size necessary for effective reduction of combustion vibration as well as a first throat 32 having a certain length.
Additionally, in accordance with the above-mentioned first through eighth embodiments, shape of transverse cross sections of the first throat 32 and the second throat 42 is not only round but also it may be polygonal.
Next, a ninth through fourteenth embodiments of the present invention will be described by referring to the drawings in sequence.
A combustor 3 in accordance with a ninth embodiment of the present invention basically has a same construction as what is applied to a gas turbine 1 shown in
Furthermore, one end 151a of the throat 151 has a resistive 152 having a multiple number of through-holes inserted and engaged. The resistive element 152 is, for example, a punching metal, ceramic sintered metal or a sintered metallic mesh.
Constructed as described above, the box body 150 functions as an air-container body which accommodates the air for resonance for fluid particles serving as vibration elements of combustion vibration that occurs in a combustion region inside the combustor basket 6. Additionally, the throat 151 functions as a junction body which connects the outer shell 8 and the box body 150. Moreover, the resistive element 152 functions as a transverse body which crosses the internal of the throat 151, and through-holes thereof function as vents where fluid particles are vibrated by resonance with the air inside the box body 150. In this way, as for combustion vibration occurring in a combustion region inside the combustor basket 6, fluid particles serving as vibration elements thereof are propagated to the internal of the outer shell 8 through the combustor basket 6; trapped effectively by the resistive element 152; then resonate with the air in an internal space of the box body 150; and vibrate in the neighborhood of the resistive element 152. By this vibration, vibration amplitude of the fluid particles is damped and the combustion vibration thereof is reduced. As a result, a stable decrease in NOx is realized.
An outline arrow in the drawing shows a flow of compressed air that is compressed by the compressor 2. Compressed air first flows into the internal of the casing 5; next reverses for approximately 180 degrees after passing through a tubular space being formed by an outer circumference surface of the combustor basket 6 and an inner circumference surface of the outer shell 8, so as to be introduced into the internal of the combustor basket 6 from the rear-end side thereof; and then is subject to diffusion combustion and pre-mixed combustion with a fuel inside the combustor basket 6. Combustion gas produced as a result is discharged to the turbine 4 from the front end thereof through the transition piece 7.
Next, a tenth embodiment of the present invention will be described by referring to
Therefore, in accordance with this embodiment, the box body 150 is installed inside the casing 5. Additionally, in installation, it is only necessary to bend the throat 151 so as to be inserted into the casing 5. By this, the box body 150 itself is placed inside the casing 5 which is under approximately same pressure as the internal space, so that pressure difference between the inside and the outside is scarcely produced. As a result, special pressure-tight construction is not necessary for the box body 150, and the box body 150 does not need to get larger than necessary.
Next, an eleventh embodiment of the present invention will be described by referring to
To put simply, as shown in
Constructed as described above, same as the above-mentioned ninth and tenth embodiments, fluid particles resonate with the air in an internal space of the box body 150 and vibrate in the neighborhood of a resistive element 152, damping the vibration amplitude thereof.
Additionally, an object to which one end 151a of the throat 151 opens may be a side wall of the outer shell 8.
Next, a twelfth embodiment of the present invention will be described by referring to
Before describing characteristic of the relevant embodiment, general layout of a combustor in a gas turbine will be described. As shown in
Characteristic of the relevant embodiment will be described hereinafter. A first annulus pipe body 130 having an annulus internal space concentrically with the main shaft J is installed so as to be located outside a rear-end wall of each of outer shells 8. Additionally, the first annulus pipe body 130 is connected to the rear-end wall of each of outer shells 8 respectively through a first throat 131 in a tube form having a predetermined length, and the first throat 131 has each of ends 131a open to the internal of each of outer shells 8, namely an area upstream of a combustion area and has each of the other ends 131b open to the internal of the first annulus pipe body 130.
Furthermore, one end 131a of the first throat 131 has a first resistive element 132 having a multiple number of through-holes inserted and engaged. Same as the resistive element 152 in accordance with the ninth through eleventh embodiments, the first resistive element 132 is, for example, a punching metal, ceramic sintered metal or a sintered metallic mesh.
Constructed as mentioned above, a first annulus pipe body 130 functions as an air-container body which accommodates the air for resonance for fluid particles serving as vibration elements of combustion vibration that occurs in a combustion region inside each of combustor baskets 6. Additionally, each of first throats 131 functions as a junction body which connects each of outer shells 8 and the first annulus pipe body 130. Moreover, each of first resistive elements 132 functions as a transverse body which crosses the internal of the first throat 131, and through-holes thereof function as vents where fluid particles are vibrated by resonance with the air inside the first annulus pipe body 130. In this way, fluid particles serving as vibration elements of combustion vibration that occurs in a combustion region inside each of combustor baskets 6 are trapped effectively by each of first resistive elements 132, resonate with the air in the first annulus pipe body 130 being connected through each of first throats 131, and vibrate in the neighborhood of each of first resistive elements 132. By this vibration, vibration amplitude of the fluid particles in each of combustors 3 is damped and the combustion vibration thereof is reduced. As a result, a stable decrease in NOx is realized as an entire gas turbine, thereby achieving reduction of NOx in exhaust gas.
Next, a thirteenth embodiment of the present invention will be described by referring to
Consequently, as shown in
Constructed as described above, an internal space in the first annulus pipe body 130 being one continuous space is divided by a first dividing wall 135 for every first throat 131, namely for every combustor 3, thereby restraining a phase difference of pressure fluctuation from occurring in an individual partitioned space. As a result, because fluid particles vibrate effectively enough in the neighborhood of each of first resistive elements 132, combustion vibration can be reduced thoroughly.
Next, a fourteenth embodiment of the present invention will be described by referring to
To put simply, as shown in
Furthermore, each of ends 141a of each of second throats 141 has a second resistive element 142 having a multiple number of through-holes inserted and engaged. Same as the first resistive element 132, the second resistive element 142 is, for example, a punching metal, ceramic sintered metal or a sintered metallic mesh.
Constructed as described above, fluid particles not only vibrate in the neighborhood of each of first resistive elements 132 but also resonate with the air inside the second annulus pipe body 140 connected through each of second throats 141 and vibrate in the neighborhood of each of second resistive elements 142, damping the vibration amplitude thereof. As a result, it is possible to make fluid particles vibrate in a multiple number of locations, thereby reducing combustion vibration efficiently.
In
Additionally, from a same purpose as the thirteenth embodiment, second dividing walls (not illustrated) may be installed respectively between each of ends 141b of each of second throats 141 in the second annulus pipe body 140. By doing this, an internal space of the second annulus pipe body 140 being one continuous space is divided by second dividing walls for every second throat 141, namely for every combustor 3 through a first throat 131, thereby restraining a phase difference of pressure fluctuation from occurring in an individual space segment. As a result, because fluid particles vibrate effectively enough in the neighborhood of each of second resistive elements 142, coupled with vibration of fluid particles in the neighborhood of each of first resistive elements 132, combustion vibration can be reduced more thoroughly.
Moreover, an object to which one end 131a of each of first throats 131 opens may be a side wall of the combustor basket 6 or a side wall of the outer shell 8 as long as it is a part of an area upstream of a combustion region.
Additionally, in accordance with the above-mentioned ninth through fourteenth embodiments, shape of a transverse cross-section of a throat 151 or a first throat 131 or a second throat 141 is not limited to a circle but it may be a polygon.
Next, a fifteenth embodiment through twenty-first embodiments of the present invention will be described in sequence by referring to the drawings.
A combustor 3 in accordance with a fifteenth embodiment is applied to a gas turbine shown in
Furthermore, the bypass duct 11 has a plate-type member 250 installed so as to transverse therein, and the plate-type member 250 has a multiple number of through-holes 251 formed therein. Such a plate-type member 250 as this is not limited to a metal plate having through-holes 251 drilled through but a punching metal, ceramic sintered metal or a sintered metallic mesh may be applicable.
Constructed as described above, the casing 5 functions as an air-container body which accommodates the air for resonance for fluid particles serving as vibration elements of combustion vibration that occurs in a combustion region inside the combustor basket 6. Additionally, the bypass duct 11 functions as a junction body which connects the transition piece 7 and the casing 5. Moreover, the plate-type member 250 functions as a transverse body which crosses the internal of the bypass duct 11, and through-holes 251 thereof function as vents where fluid particles are vibrated by resonance with the air inside the casing 5. In this way, fluid particles serving as vibration elements of combustion vibration that occurs in a combustion region inside the combustor basket 6 are propagated through the transition piece 7; next introduced from one end 11a of the bypass duct 11 and trapped effectively by each of through-holes 251 of the plate-type member 250; then resonate with the air in the casing 5 being connected through the bypass duct 11 and vibrate through each of through-holes 251. By this vibration, vibration amplitude of the fluid particles is damped and the combustion vibration thereof is reduced. As a result, a stable decrease in NOx is realized.
Additionally, in
Next, a sixteenth embodiment of the present invention will be described by referring to
First characteristic requires the bypass duct 11 to originally have a function to introduce the bypass air from the casing 5 to the internal of the cylinder body (transition piece 7) and adjust the density of combustion gas, namely a function to adjust the flow of the bypass air. This is because, while remaining to be so constructed as the fifteenth embodiment, the plate-type member 250 serves as an obstacle, which makes the bypass air flow insufficient, resulting in such a case as the original function of the bypass duct 11 cannot be carried out.
Second characteristic is for a case where damping responsiveness is deteriorated remarkably according to frequency areas of combustion vibration because in a region of the plate-type member 250 corresponding to a transverse cross-section of the bypass duct 11, responsiveness of damping to various frequency areas of combustion vibration is determined by the ratio occupying the opening area (sometimes referred as “opening ratio” hereinafter) of through-holes 251.
Therefore, in accordance with the relevant embodiment, as shown in
Moreover, the bypass duct 11 has the bypass valve 12 installed adjacent to the plate-type member 250. Same as the plate-type member 250, the bypass valve 12 is movable by sliding in a transverse direction (an arrow Y in
Then, by operating the bypass-valve variable mechanism 13, the lever 12c moves in a circumferential direction, and with this, the foundation plate member 12a slides and rotates in a circumferential direction, namely slides to move in a transverse direction (an arrow Y in
Behavior of the combustor 3 being constructed as mentioned above will be described hereinafter by referring to
For example, when the bypass air is stopped to flow in by closing the bypass duct 11, the plate-type member 250 is slid to move and selected so as to have the through-area B coincide with an area corresponding to a transverse cross-section of the bypass duct 11, and at the same time, the bypass valve 12 is slid so as not to cover the through-hole 12b. (See
When the combustion vibration is to be reduced, as shown in
As a result, it is possible to surely reduce combustion vibration for various frequency areas without damaging the original function of the bypass duct.
Next, a seventeenth embodiment of the present invention will be described by referring to
To put simply, as shown in
Being constructed as mentioned above, when the flow of the bypass air is adjusted, the plate-type member 250 is slid to move appropriately and selected so as to have the through-holes areas A1, A2 . . . , through-area B and non-through-holes area C coincide with an area corresponding to the transverse cross-section of the bypass duct 11. By this, the degree of opening and closure of the bypass valve 12 is adjusted, thereby adjusting the flow of the bypass air, which is the original function of the bypass duct 11.
On the other hand, when combustion vibration is to be reduced, the plate-type member 250 is slid to move and selected so as to have through-holes areas A1, A2 . . . , being worth various frequency areas of combustion vibration, coincide with an area corresponding to the transverse cross-section of the bypass duct 11. By this, responsiveness of damping to combustion vibration in the frequency-area thereof is secured, thereby reducing the combustion vibration.
As a result, same as the sixth embodiment, combustion vibration in various frequency areas can surely be reduced without damaging the original function of the bypass duct, and additionally, it is not necessary to install such the bypass valve 12 as in accordance with the sixteenth embodiment separately. In other words, because the function of the bypass valve 12 is shared by the plate-type member 250, there is an advantage that construction is simple.
Next, an eighteenth embodiment of the present invention will be described by referring to
Therefore, in accordance with the relevant embodiment, into the end 11b of the bypass duct 11 is inserted and engaged a cylindrical member 255 being able to protrude axially and having a predetermined length. By this, the cylindrical member 255 is made to protrude, which makes the distance L substantially extend from the plate-type member 250 to the tip of the cylindrical member 255. Therefore, because the distance L can be adjusted freely by adjustment of protruding amount of the cylindrical member 255, it is possible to adjust the degree of a decrease in combustion vibration which fluctuates, depending on the distance L. As a result, setting is possible so as to reduce combustion vibration thoroughly.
Next, a nineteenth embodiment of the present invention will be described by referring to
To put simply, in accordance with the relevant embodiment, as shown in
Constructed as described above, the bypass duct 11 functions as an air-container body which accommodates the air for resonance for fluid particles serving as vibration elements of combustion vibration that occurs in a combustion region inside the combustor basket 6. Additionally, a dividing wall 260 and a protruding pipe 261 function as junction bodies which connect the transition piece 7 and the bypass duct 11. Moreover, a resistive element 262 functions as a transverse body which crosses the internal of the protruding pipe 261, and through-holes thereof function as vents where fluid particles are vibrated by resonance with the air inside the bypass duct 11. In this way, as for combustion vibration that occurs in a combustion region inside the combustor basket 6, fluid particles are propagated through the transition piece 7, next introduced from one end 11a of the bypass duct 11 and trapped effectively by the resistive element 262 in the protruding pipe 261, then resonate with the air in a space from the dividing wall 260 to the other end 11b in the bypass duct 11 being connected through the protruding pipe 261, and vibrate in the neighborhood of the resistive element 262. By this vibration, vibration amplitude of the fluid particles is damped and the combustion vibration thereof is reduced. As a result, a stable decrease in NOx is realized.
Additionally, in
Next, a twentieth embodiment of the present invention will be described by referring to
To put simply, in accordance with the relevant embodiment, as shown in
Next, a twenty-first embodiment of the present invention will be described. Characteristic of a twenty-first embodiment is that combustion vibration is reduced sufficiently in the combustor 3 in accordance with the fifteenth through twentieth embodiments.
As shown in
Furthermore, the throat 232 has a resistive element 233 having a multiple number of through-holes inserted and engaged therein. Same as the resistive element 262 in accordance with the nineteenth and twentieth embodiments, the resistive element 233 is, for example, a punching metal, ceramic sintered metal or a sintered metallic mesh.
Constructed as described above, as for combustion vibration that occurs in a combustion region inside the combustor basket 6, fluid particles vibrate not only in through-holes 251 of a plate-type member 250 but also resonate with the air in an internal space 231 being connected through a throat 232 and vibrate in the neighborhood of a resistive element 233 in the throat 232, thereby damping the vibration amplitude thereof. As a result, combustion vibration can be reduced more sufficiently.
In addition, in
Subsequently, a twenty-second through thirty-first embodiments of the present invention will be described sequentially by referring to the drawings.
A combustor 3 in accordance with a twenty-second embodiment is applied to a gas turbine shown in
Around the outer circumference of the side wall in the neighborhood of the combustion region F in the transition piece 7 is installed a resonator 320 (sometimes referred as “acoustic liner” hereinafter), and a cavity 321 is formed by a side wall, front-end wall and rear-end wall of the acoustic liner 320 and a side wall of the transition piece 7. Moreover, on a side wall of the transition piece 7 are formed a plurality of sound-absorption holes 322 penetrating from the internal thereof through the cavity 321, so as to be arranged regularly.
In addition, as shown in
Constructed as described above, the first box body 330 functions as an air-container body which accommodates the air for resonance for fluid particles serving as vibration elements in a low-frequency area of combustion vibration that occurs in a combustion region inside the combustor basket 6. Additionally, the acoustic liner 320 and the first throat 332 function as junction boxes which connect a transition piece 7 and the first box body 330. Moreover, a side wall of the transition piece 7 functions as a transverse body which crosses the internal of the acoustic liner 320, and further, through-holes 322 thereof function as vents where fluid particles in a low-frequency area are vibrated by resonating with the air inside the first box body 330. In this way, as for combustion vibration that occurs in a combustion region F, fluid particles serving as vibration elements in a high-frequency area of combustion vibration resonate with the air in a cavity 321 inside the acoustic liner 320 and vibrate through the sound-absorption holes 322, thereby damping the vibration amplitude thereof.
On the other hand, fluid particles serving as vibration elements in a low-frequency area resonate with the air inside the first internal space 331 through the cavity 321 and the first throat 332 and vibrate through the sound-absorption holes 322, thereby damping the vibration amplitude thereof. In this way, combustion vibration is reduced, regardless of frequency areas, and as a result, a stable decrease in NOx is realized.
Additionally, in
Next, a twenty-third embodiment of the present invention will be described by referring to
Therefore, according to the relevant embodiment, as shown in
Constructed as described above, the first resistive element 333 plays a role as a barrier so as to restrain resonance with the air inside the first internal space 331. By this, resonance with the air in a cavity 321 inside the acoustic liner 320 is secured, and in consequence, fluid particles effectively vibrate through the sound-absorption holes 322, thereby damping the vibration amplitude thereof. In addition, for combustion vibration in a low-frequency area, resonance with the air in the first internal space 331 is secured, and fluid particles are effectively trapped by the first resistive element 333 serving as resistance, and vibrate in the neighborhood thereof, thereby damping the vibration amplitude thereof.
Next, a twenty-fourth embodiment of the present invention will be described by referring to
Therefore, in accordance with the relevant embodiment, as shown in
Because in this way, it is possible to make the cross-sectional area of the internal of the first throat 332, namely the other end 332b, smaller and at the same time it is possible to expand an area where the first resistive element 333 exists, the ratio of trapping of fluid particles in a low-frequency area is increased, thereby contributing sufficiently to reduction of combustion vibration as a whole. As a result, it is possible to reduce thoroughly combustion vibration in a low-frequency area as a whole.
Additionally, when a trumpet-like object whose inner circumference gradually expands is applied as the first throat 332, same effects can be obtained.
Next, a twenty-fifth embodiment of the present invention will be described by referring to
Therefore, in accordance with the relevant embodiment, as shown in
Constructed as described above, because a phase difference of each of pressure fluctuations occurs between a first internal space 331 and a space inside the first throat 332, in order to make fluid particles vibrate effectively in the neighborhood of a resistive element 334, by utilizing this, combustion vibration in a low-frequency area can be reduced sufficiently, although vibration of fluid particles in the neighborhood of the first resistive element 333 is insufficient.
Moreover, same effect can be obtained although the resistive element 334 is installed to either side of the end 332b which has a smaller cross-sectional area than the other end 332a of the first throat 332.
Next, a twenty-sixth embodiment of the present invention will be described by referring to
To put simply, as shown in
By this, it is possible to substantially expand the capacity of the first internal space 331 as a whole, thereby enhancing efficiency of resonance with the air in the first internal space 331 for combustion vibration in a low-frequency area. As a result, vibration efficiency of fluid particles being caused by this resonance is enhanced, thereby making it possible to reduce combustion vibration in a low-frequency area more sufficiently as a whole.
Here, in
In addition, when the opening area or the length of each of ends 332b of the first throat 332, or the capacity of each of first internal spaces 331 being formed by each of first box bodies 330 is determined appropriately in advance so as to be mutually different, vibration properties responding to each of first box bodies 330 and the like will differ, so that it is possible to respond to various combustion vibrations in different frequency areas without fail.
Next, a twenty-seventh embodiment of the present invention will be described by referring to
Therefore, in accordance with the relevant embodiment, as shown in
Constructed as described above, the cavity 321 is divided by the dividing wall 323 for every first throat 332, thereby making it possible to restrain a phase difference of pressure fluctuation in an individual divided space from occurring. As a result, in combustion vibration in a high-frequency area, fluid particles vibrate effectively through sound-absorption holes 322, and in combustion vibration in a low-frequency area, fluid particles vibrate through sound-absorption holes 322 and vibrate in the neighborhood of the first resistive element and the like effectively, thereby making it possible to reduce combustion vibration thoroughly.
Next, a twenty-eighth embodiment of the present invention will be described by referring to
To put simply, as shown in
Next, a twenty-ninth embodiment of the present invention will be described by referring to
To put simply, as shown in
Next, a thirtieth embodiment of the present invention will be described by referring to
First problem is that because of having a combustion region F inside, the combustor basket 6 and the transition piece 7 which serve as cylinder bodies having a resonator 3 installed around the outer circumference thereof are subject to an environment of continually heating, which eventually results in heating of the acoustic liner 320 and the first box body 330. Therefore, it is required to prevent these cylinder body, acoustic liner 320 and the like from being subject to excessive increase in temperature.
Second problem is that sometimes a part of combustion gas being generated in a combustion region F in a cylinder body flows into the internal of the acoustic liner 320 or internal of the first box body 330 by way of sound-absorption holes 322 and further through the first throat 332. In such a case, a fuel and water vapor being contained in a part of combustion gas is liquefied and accumulates inadvertently. Therefore, it is required to discharge this inadvertent stagnant liquid outside the acoustic liner 320 and the first box body 330.
Therefore, as shown in
Additionally, the vertically lowest portion of the acoustic liner 320 and the first box body 330 have a drain hole 325 for the acoustic liner and a drain hole 336 for the first box body, which discharge stagnant liquid from inside to outside respectively. By this, it is possible to discharge outside inadvertent stagnant liquid being accumulated inside the acoustic liner 320 and the first box body 330, thereby solving the above-mentioned second problem.
Next, a thirty-first embodiment of the present invention will be described by referring to
To put simply, in accordance with the relative embodiment, as shown in
Additionally, the second throat 342 has a second resistive element 343 having a multiple number of through-holes inserted and engaged to an end 342a thereof. Same as the first resistive element 333, the second resistive element 343 is, for example, a punching metal, a ceramic sintered metal or sintered metallic mesh. Moreover, in
By this, fluid particles in a low-frequency area not only vibrate through sound-absorption holes 322 or vibrate in the neighborhood of the first resistive element 333 and the like but also resonate with the air in the second internal space 341 so as to vibrate in the neighborhood of the second resistive element 343, thereby damping the vibration amplitude thereof. As a result, fluid particles can vibrate in a multiple number of locations, which makes it possible to efficiently reduce combustion vibration in a low-frequency area.
Additionally, in
Moreover, same as concepts of the twenty-fourth through twenty-sixth embodiments, considering sufficient response to combustion vibration in a low-frequency area, the following modifications are possible. Following the first throat 332 in accordance with the twenty-fourth embodiment, an opening area of one end 342a of the second throat 342 is larger than that of the other end 342b. Following the resistive element 334 of the first throat 332 in accordance with the twenty-fifth embodiment, one end 342b of the second throat 342 has a resistive element having a multiple number of through-holes inserted and engaged. Following the first box body 330 in accordance with the twenty-sixth embodiment, a plurality of second box bodies 340 and the like are installed in parallel.
Furthermore, same as a concept of the twenty-ninth embodiment, in order to utilize a phase difference of pressure fluctuation between adjoining second box bodies 340 being installed in parallel, each of adjoining second box bodies 340 being installed in parallel has a second wall surface 340a which is shared so as to form a second internal space 341 mutually, and the second wall surface 340a can have a multiple number of through-holes as resistive elements.
In addition, same as a concept of the thirtieth embodiment, in order to solve a problem peculiar to a combustor 3, the second box body 340 has a plurality of fluid-introducing holes for cooling of a second box body, introducing the cooling fluid from outside to inside, formed therein, and furthermore, has a drain hole for the second box body, discharging stagnant liquid from inside to outside, formed therein.
Moreover, in accordance with the twenty-second through thirty-first embodiments, a shape of a transverse cross-section of the first throat 331 or the second throat 341 is not limited to a circle but may be a polygon. In addition, the first box body 330 or the second box body 340 may have the first internal space 331 or the second internal space 341 formed by an internal cavity respectively. In such a case, it is only to directly connect to the acoustic liner 320 or the first box body 330 through the first throat 332 or the second throat 342 respectively.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments or an example to which these embodiments are applied concretely, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
As described above, the present invention is useful for a gas turbine combustor and a gas turbine for which realization of reduction of NOx is desired.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP03/15298 | 11/28/2003 | WO | 2/17/2005 |
