Patent Application
20160265431
The present invention relates to a nozzle, a combustion apparatus, and a gas turbine.
Priority is claimed on Japanese Patent Application No. 2013-247076, filed Nov. 29, 2013, the content of which is incorporated herein by reference.
As a combustion apparatus of a gas turbine, there is a combustion apparatus which includes a pilot fuel nozzle, and a plurality of main fuel nozzles provided around the pilot fuel nozzle. In the combustion apparatus, the stability of main pre-mixed flames is improved in diffusion flames formed by the pilot fuel nozzle.
Patent Document 1 discloses a configuration in which a region which does not have fuel injection holes is provided in some of pilot fuel nozzles in a circumferential direction, and fuel injected from the pilot fuel nozzles is non-uniformly distributed in the circumferential direction. In addition, Patent Document 1 discloses a configuration which causes the fuel injection amount of the fuel between a plurality of main fuel nozzles to be different from each other so as to non-uniformly distribute the fuel, which is injected from the plurality of main fuel nozzles to the outer circumferential sides of the pilot fuel nozzles, in the circumferential direction.
According to this configuration, the lengths of flames formed by combustion of the fuel are different from each other in the circumferential direction, and since the heat release rate is distributed, combustion oscillation decreases.
Patent Document 2 discloses a configuration in which fuel injection holes are respectively provided at a plurality of positions different from each other in an axial direction in a plurality of main fuel nozzles. In addition, Patent Document 2 discloses a configuration in which the fuel injection holes are respectively provided at a plurality of positions different from each other in the axial direction in the plurality of main fuel nozzles, and fuel injection angles from the fuel injection holes are different from each other. According to this configuration, periods of time elapsed from when fuel (pre-mixed gas) injected from the main fuel nozzles reaches flames are different from each other between the plurality of fuel injection holes having different positions in the axial direction, and combustion oscillation decreases.
Patent Document 1: Japanese Unexamined Patent Application, First Publication No. H11-294770
Patent Document 2: Japanese Unexamined Patent Application, First Publication No. 2003-120934
In recent years, there is a combustion apparatus having a method which injects water to flames in order to decrease emission of NOx (nitrogen dioxide) by decreasing the temperatures of the flames in the combustion apparatus.
In the combustion apparatus, it is necessary to effectively decrease combustion oscillation.
The present invention provides a nozzle, a combustion apparatus, and a gas turbine capable of effectively decreasing combustion oscillation, even in a combustion apparatus in which water is injected to flames.
A first aspect of the present invention includes a nozzle in which a fuel injection port for injecting a fuel is formed on the center of a tip and a plurality of water injection ports are formed with intervals therebetween in a circumferential direction around the fuel injection port of the tip, in which the water injection ports are non-uniformly formed in the circumferential direction.
According to this configuration, water injected from the water injection ports are non-uniformly injected in the circumferential direction with respect to flames generated by the fuel injected from the fuel injection port. Accordingly, axial positions of the flames are not uniform in the circumferential direction. Therefore, the axial positions of the flames, or the axial positions of the flames generated by fuel ignited by the flames are different from each other in the circumferential direction, and the heat release rate is distributed so as to decrease combustion oscillation.
According to a second aspect of the present invention, in the nozzle of the first aspect, some of the plurality of water injection ports may be formed such that inclination angles with respect to the center axis of the nozzle in a radial direction of the nozzle are different from inclination angles of the remaining water injection portions.
Accordingly, the injection angle of water which is injected from the water injection ports to a partial region in the circumferential direction is different from an injection angle of water which is injected from the water injection ports to remaining regions, except for the partial region, in a radial direction of the nozzle. Therefore, it is possible to non-uniformly inject water to flames in the circumferential direction.
According to a third aspect, in the nozzle of the first or second aspect, some of the plurality of water injection ports may be formed such that the inclination angles with respect to the center axis of the nozzle in a circumferential direction of the nozzle are different from the inclination angles of the remaining water injection ports.
Accordingly, the injection angle of water which is injected from the water injection ports to a partial region in the circumferential direction is different from the injection angle of water which is injected from the water injection ports to remaining regions, except for the partial region, in the circumferential direction of the nozzle (that is, a tangential direction at the position of the water injection port). Therefore, it is possible to non-uniformly inject water to flames in the circumferential direction.
According to a fourth aspect of the present invention, in the nozzle of any one of the first to third aspects, some of the plurality of water injection ports may be formed such that opening diameters are different from opening diameters of the remaining water injection ports.
Accordingly, an injection amount of water which is injected from the water injection ports to a partial region in the circumferential direction is different from an injection amount of water which is injected from the water injection ports to remaining regions except for the partial region. Therefore, it is possible to non-uniformly inject water to flames in the circumferential direction.
According to a fifth aspect of the present invention, in the nozzle of any one of the first to fourth aspects, some of the plurality of water injection ports may be formed such that opening positions of a diameter direction of the nozzle are different from opening positions of the remaining water injection ports.
Accordingly, the distance from the point at which the water injected from the water injection ports is injected from a partial region in the circumferential direction to the point at which the water reaches flames generated by a fuel injected from a fuel injection port positioned at the center portion is different from the distance from the point at which the water injected from the water injection ports is injected from remaining regions, except for the partial region, to the point at which the water reaches the flames. Therefore, it is possible to non-uniformly inject water to flames in the circumferential direction.
According to a sixth aspect of the present invention, in the nozzle of any one of the first to fifth aspects, some of the plurality of water injection ports may be formed such that installation intervals in the circumferential direction of the nozzles are different from those of the remaining water injection ports.
Accordingly, the injection amount (injection density) of the water injected from the water injection ports to a partial region in the circumferential direction is different from the injection amount of the water injected from the water injection ports to the remaining regions except for the partial region. Therefore, it is possible to non-uniformly inject water to flames in the circumferential direction.
According to a seventh aspect of the present invention, there is provided a combustion apparatus, including: a main nozzle which injects a fuel; and a pilot nozzle which generates flames to ignite the fuel injected from the main nozzle, in which the pilot nozzle may be the pilot nozzle according to any one of the first to sixth aspects.
Accordingly, it is possible to make flames for ignition generated by the pilot nozzle be non-uniform in the circumferential direction. Therefore, flames generated by the fuel injected from the main nozzle are also non-uniform in the circumferential direction.
According to an eighth aspect of the present invention, in the combustion apparatus of the seventh aspect, the pilot nozzle may be disposed in the center portion, and a plurality of the main nozzles may be provided on an outer circumferential side of the pilot nozzle in a circumferential direction.
A ninth aspect of the present invention includes a gas turbine, including: the combustion apparatus according to the seventh or eighth aspect; and a turbine main body which is driven by combustion gas generated by the combustion apparatus.
According to the gas turbine, it is possible to decrease combustion oscillation due to flames in the combustion apparatus.
According to the nozzle, it is possible to effectively decrease combustion oscillation, even in the combustion apparatus in which water is injected to flames.
Hereinafter, a combustion apparatus 3 according to a first embodiment of the present invention will be described with reference to the drawings.
As shown in
The compressor 2 and the turbine main body 4 respectively include rotors 5 which are connected so as to rotate integrally with each other, and stators 6 which surround outer circumferences of the rotors 5. Each rotor 5 includes a rotary shaft 7, and a plurality of annular blade groups 8 which are fixed with intervals therebetween in an axial direction. Each annular blade group 8 is configured so as to include a plurality of blades, which are fixed with intervals therebetween in a circumferential direction, on the outer circumference of the rotary shaft 7.
Each stator 6 includes a casing 9, and a plurality of annular vane groups 10 which are fixed with intervals in the axial direction in the casing 9. Each annular vane group 10 includes a plurality of vanes which are fixed to the inner surface of the casing 9 with intervals therebetween in the circumferential direction.
The annular vane groups 10 and the plurality of annular blade groups 8 are alternately disposed in the axial direction.
As shown in
First end side 32a of the outer shell 32 is closed, and second end side 32b thereof is open from the outer circumferential side of the combustor basket 31. The compressed air A flowing from a portion between the inner circumferential surface of the second end side 32b of the outer shell 32 and the outer circumferential surface of the combustor basket 31 into the combustion apparatus 3 rotates 180° at the first end side 32a of the outer shell 32, and is supplied into the combustor basket 31.
As shown in
The pilot burner 33 includes a pilot nozzle 35 and a pilot cone 36.
The pilot nozzle 35 is provided along a center axis O of the combustor basket 31 from the first end side 32a of the outer shell 32. The pilot nozzle 35 injects a fuel, which is supplied via a fuel supply path (not shown) from the first end side 32a of the outer shell 32, from a tip portion 35a, and the fuel is ignited so as to generate flames.
The pilot cone 36 is formed in a tubular shape, and is provided on the outer circumferential side of the tip portion 35a of the pilot nozzle 35. The pilot cone 36 has a tapered cone portion 36c in which an inner diameter gradually increases from the vicinity of the tip portion 35a of the pilot nozzle 35 toward a generation direction of the flames, and regulates the diffusion range and the direction of the flames so as to increase flame insulation properties.
Each main burner 34 includes a main nozzle 37 and a main swirler 38. A tubular outer circumferential cone 39 is provided on the outer circumference of the pilot cone 36. The plurality of main nozzles 37 are provided with intervals therebetween in the circumferential direction in a region between the outer circumferential surface of the outer circumferential cone 39 and the inner circumferential surface of the combustor basket 31. The main nozzles 37 are provided so as to be parallel to the center axis O of the combustor basket 31 from the first end side 32a of the outer shell 32.
The main swirler 38 is provided on the tip portion of each main nozzle 37. A fuel (main fuel) is injected from a fuel nozzle (not shown) to the outer circumferential surface side of the main nozzle 37 on the air flow upstream side of the main swirler 38. In addition, this fuel is mixed with the compressed air A inside the combustor basket 31 in the main burners 34 by the main swirlers 38 to generate pre-mixed gas.
The pilot nozzle 35 of the present embodiment injects water toward flames so as to decrease temperatures of the flames and decrease NOx. Hereinafter, a configuration of the pilot nozzle 35 will be described.
As shown in
A plurality of water injection ports 42 are formed around the fuel injection port 41 of the tip surface 35s of the pilot nozzle 35 with intervals therebetween in the circumferential direction. Water is supplied from a water supply source (not shown) to the water injection ports 42 through water passages which are formed in the pilot nozzle 35. Each water injection port 42 is formed so as to be inclined toward the inner circumferential side in the radial direction of the pilot nozzle and in the circumferential direction with respect to the center axis O of the pilot nozzle 35. Accordingly, water injected from each water injection port 42 is sprayed on the outer edge portions of flames F1 generated by the fuel injected from the fuel injection port 41 positioned on the inner circumferential side of the plurality of water injection ports 42. As shown in
The plurality of water injection ports 42 are non-uniformly formed in the circumferential direction.
In the present embodiment, among the plurality of water injection ports 42, inclination angles θ1 of water injection ports 42A of a partial region in the circumferential direction toward the inner circumferential side in the radial direction of the pilot nozzle 35 with respect to the center axis O of the pilot nozzle 35 are different from inclination angles θ2 of water injection ports 42B of the remaining regions except for the partial region. For example, the inclination angles θ1 of the water injection ports 42A of the partial region are smaller than the inclination angles θ2 of the water injection ports 42B (the remaining water injection ports) of the remaining regions except for the partial region.
Accordingly, in water injected from the water injection ports 42 toward the inner circumferential side of the pilot nozzle 35, the water injected from the water injection ports 42A positioned in the partial region in the circumferential direction is injected toward the outer circumferential side relative to other water injection ports 42B. Therefore, the water injected from the plurality of water injection ports 42 of the pilot nozzle 35 is non-uniformly injected to the flames F1 generated by the fuel injected from the central fuel injection port 41, in the circumferential direction. As the inclination angles of the water injection ports 42 toward the inner circumferential side in the radial direction decrease, the distance, in which the water injected from the water injection ports 42 reaches the outer edge portions of the flames F1 on the downstream side in the injection direction of water from the water injection ports 42, increases. Accordingly, axial positions of the flames F1 are non-uniform in the circumferential direction.
Therefore, ignition positions of the fuel injected from the main burners 34, that is, generation positions of the main flames are different from each other in the direction along the center axis O in the circumferential direction due to the flames F1 having different axial positions in the circumferential direction. As the inclination angle θ1 of the injection angle of water decreases, the generation position of the main flame due to the fuel injected from the main burner 34 transfers to the downstream side in the generation direction of the flame along the center axis O direction.
In this way, the positions in the center axis O direction of the main flames generated in the combustion apparatus 3 are different from each other in the circumferential direction. Accordingly, as shown in
Therefore, it is possible to decrease the vibrating force which is generated by one vibration mode due to the flames F1 or the main flames. As a result, it is possible to effectively decrease combustion oscillation.
In addition, in the first embodiment, since the inclination angles of the water injection ports 42 in the radial direction of the pilot nozzle 35 are different from each other, the plurality of water injection ports 42 are non-uniform in the circumferential direction. However, the present invention is not limited to this. Hereinafter, a plurality of embodiments is shown in which the plurality of water injection ports 42 is non-uniformly formed in the circumferential direction. In addition, in the embodiments described below, the entire configuration of the gas turbine 1 or the combustion apparatus 3 is the same as that of the first embodiment. Accordingly, in descriptions below, in the drawings, the same reference numerals are assigned to configurations which are the same as those of the first embodiment, descriptions thereof are omitted, and the configuration of the water injection port 42 in the pilot nozzle 35 is mainly described.
As shown in
Accordingly, in water injected from the water injection ports 42, the water injected from the water injection ports 42C positioned in the partial region in the circumferential direction is injected toward the upstream side in the generation direction of the flame F1 relative to other water injection ports 42D.
Accordingly, as shown in
Accordingly, positions at which the flames F1 are propagated to the fuel injected from the main burner 34 and the fuel is ignited are different from each other in the direction along the center axis O. Therefore, as shown in
As a result, it is possible to decrease a vibrating force which is generated by one vibration mode due to the flames F1 or the main flames. Accordingly, it is possible to effectively decrease combustion oscillation.
As shown in
Accordingly, in water injected from the water injection ports 42, an injection amount of the water injected from the water injection ports 42E positioned in the partial region in the circumferential direction is larger than injection amounts of other water injection ports 42F.
Accordingly, as shown in
Accordingly, positions at which the flames F1 are propagated to the fuel injected from the main burner 34 and the fuel is ignited are different from each other in the direction along the center axis O. Therefore, as shown in
As a result, it is possible to decrease a vibrating force which is generated by one vibration mode due to the flames F1 or the main flames. Accordingly, it is possible to effectively decrease combustion oscillation.
As shown in
Accordingly, in water injected from the water injection ports 42, the water injected from the water injection ports 42G positioned in the partial region in the circumferential direction reaches the outer edge portion of the flames F1 on the downstream side in the generation direction of the flame F1 relative to other water injection ports 42H.
Accordingly, as shown in
Accordingly, positions at which the flames F1 are propagated to the fuel injected from the main burner 34 and the fuel is ignited are different from each other in the direction along the center axis O. Therefore, as shown in
As a result, it is possible to decrease a vibrating force which is generated by one vibration mode due to the flames F1 or the main flames. Accordingly, it is possible to effectively decrease combustion oscillation.
As shown in
Accordingly, in water injected from the water injection ports 42, the injection amount (injection density) of the water injected from the water injection ports 42J positioned in the partial region in the circumferential direction is larger than the injection amount of the water injected from other water injection ports 42K.
Accordingly, as shown in
Accordingly, positions at which the flames F1 are propagated to the fuel injected from the main burner 34 and the fuel is ignited are different from each other in the direction along the center axis O. Therefore, as shown in
As a result, it is possible to decrease a vibrating force which is generated by one vibration mode due to the flames F1 or the main flames. Accordingly, it is possible to effectively decrease combustion oscillation.
In addition, the present invention is not limited to the embodiments described with reference to the drawings, and various modification examples may be considered within the technical range.
For example, in the embodiments, as an example in which the plurality of water injection ports 42 are non-uniformly formed in the circumferential direction, the plurality of water injection ports 42 are divided into the water injection ports 42A, 42C, 42E, 42G, and 421 positioned the partial regions in the circumferential direction and the water injection ports 42B, 42D, 42F, 42H, and 42K of the remaining regions, except for the partial regions, in the circumferential direction. However, the present invention is not limited to this. The plurality of water injection ports 42 may be non-uniformly formed so as to be divided into many divisions in the circumferential direction.
In addition, the inclination angles, the opening diameter, the positions in the radial direction, and installation intervals of the plurality of water injection ports 42 are formed in two steps such as the partial region in the circumferential direction and the remaining regions except for the partial region, but may be formed in three steps or more.
In addition, the first to fifth embodiments are configured so as to be appropriately combined with each other.
Moreover, in the above-described embodiments, the fuel injection port 41 and the plurality of water injection ports 42 are formed in the pilot nozzle 35. However, the water injection ports 42 may be provided on the outer circumferential side of the pilot nozzle 35 so as to be separated from the pilot nozzle 35.
Moreover, the above-described embodiments have configurations in which the combustion apparatus 3 includes the pilot nozzle 35 at the center portion and the plurality of main nozzles 37 on the outer circumferential side. However, the combustion apparatus 3 may have any configuration, as long as the configuration of the present invention is applied to at least one of the nozzles configuring the combustion apparatus 3.
In addition, the configurations described in the embodiments may be selected within a scope which does not depart from the gist of the present invention, and may be appropriately modified to other configurations.
According to the nozzle, it is possible to effectively decrease combustion oscillation, even in a combustion apparatus in which water is injected to flames.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-247076 | Nov 2013 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2014/081186 | 11/26/2014 | WO | 00 |
