JP2014118845A - Fuel nozzle, combustion burner, gas turbine combustor, and gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel nozzle capable of properly burning fuel by determining a distribution of concentration of the fuel suitable for differential pressure of the fuel.SOLUTION: A fuel nozzle for injecting fuel into a burner cylinder in which a premixed gas prepared by mixing the fuel and combustion air in advance, is circulated, includes a fuel passage L for circulating the fuel, a low-pressure injection hole 71a communicated with the fuel passage L for injecting the fuel, a high-pressure injection hole 71b communicated with the fuel passage L for injecting the fuel, and an injection switching mechanism 75 capable of switching the injection of the fuel from the high-pressure injection hole 71b according to a fuel pressure in the fuel passage L. The injection switching mechanism 75 injects the fuel from the low-pressure injection hole 71a without injecting the fuel from the high-pressure injection hole 71b when the fuel pressure in the fuel passage L is low, and injects the fuel from at least the high-pressure injection hole 71b when the fuel pressure in the fuel passage L is high.

Description

  The present invention relates to a fuel nozzle for injecting fuel, a combustion burner, a gas turbine combustor, and a gas turbine.

  Conventionally, as a fuel nozzle, a variable area fuel nozzle that changes the size of the area through which the fuel passes according to the fuel pressure (fuel pressure) is known (see, for example, Patent Document 1). When this fuel nozzle is used as a component of a gas turbine engine, the size of the area through which the fuel passes is changed according to the load of the turbine and the like, thereby changing the fuel injection amount.

JP 2011-208638 A

  By the way, the gas turbine combustor is provided with a fuel nozzle and a premixed gas flow passage through which a premixed gas in which fuel injected from the fuel nozzle and combustion air are mixed in advance flows. In the fuel nozzle, the pressure (fuel pressure) of the fuel flowing through the fuel nozzle changes according to the generator load. That is, since the fuel injection amount in the gas turbine combustor is adjusted to a predetermined ratio, if the generator load is increased, the fuel pressure is increased to increase the fuel injection amount, while the generator If the load is lowered, the fuel pressure is lowered to reduce the fuel injection amount. The case where the generator load of the gas turbine is low is, for example, a case where a partial load operation that is an operation from when the gas turbine is ignited (started) until reaching the rated operation is performed.

  Here, in the gas turbine combustor, when the gas turbine performs full load operation, while the fuel differential pressure between the fuel pressure of the fuel nozzle and the pressure in the premixed gas passage increases, the gas turbine performs partial load operation. When performing, the fuel differential pressure of the fuel pressure of a fuel nozzle and the pressure in a premixed gas distribution channel becomes low. If the fuel concentration distribution in the premixed gas passage is made constant and becomes thinner, the fuel may not be burned suitably. In this case, since it becomes difficult to burn all the fuel components of the premixed gas, unburned components are generated, and it is difficult to maintain combustion.

  Here, although the fuel nozzle shown in Patent Document 1 changes the size of the area through which the fuel passes according to the load of the turbine and the like, the fuel in the premixed gas distribution passage depends on the fuel differential pressure. However, it is still difficult to obtain a fuel concentration distribution suitable for the fuel differential pressure.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a fuel nozzle, a combustion burner, a gas turbine combustor, and a gas turbine that can suitably burn fuel by setting the fuel concentration distribution suitable for the fuel differential pressure. To do.

  The fuel nozzle of the present invention is a fuel nozzle that injects fuel into a premixed gas distribution passage through which a premixed gas in which fuel and combustion air are premixed flows, The injection of fuel from the high-pressure injection hole is switched according to the fuel pressure in the fuel passage, the low-pressure injection hole that communicates with the passage, the fuel is injected, the high-pressure injection hole that communicates with the fuel passage, and the fuel passage. An injection switching mechanism capable of injecting fuel from the low pressure injection hole without injecting fuel from the high pressure injection hole when the fuel pressure in the fuel passage is low. When the fuel pressure is high, the fuel is injected at least from the high-pressure injection hole.

  According to this configuration, when the fuel pressure in the fuel passage is low, fuel can be injected from the low pressure injection hole. For this reason, the concentration distribution of the fuel in the premixed gas flowing through the premixed gas distribution passage can be formed by the fuel injected from the low pressure injection holes. In other words, by providing a low-pressure injection hole at a predetermined position and injecting fuel from the low-pressure injection hole, it is possible to obtain an optimum fuel concentration distribution during operation at a low fuel pressure (for example, during partial load operation with a low fuel differential pressure). can do. On the other hand, when the fuel pressure in the fuel passage is high, fuel can be injected at least from the high-pressure injection hole. For this reason, the fuel concentration distribution of the premixed gas flowing through the premixed gas distribution passage can be formed by the fuel injected from the high-pressure injection holes. That is, by providing a high-pressure injection hole at a predetermined position and injecting fuel from the high-pressure injection hole, it is possible to obtain an optimum fuel concentration distribution during operation at a high fuel pressure (for example, at full load operation with a high fuel differential pressure). can do. When the fuel pressure in the fuel passage is high, it is preferable that the fuel is injected from the high-pressure injection hole and the low-pressure injection hole. As described above, the concentration distribution of the fuel in the premixed gas circulation passage can be made an optimum distribution according to the fuel differential pressure. For this reason, premixed gas can be combusted suitably and generation | occurrence | production of an unburned component can be suppressed, Therefore Combustion stability improves.

  In this case, the premixed gas circulation passage is provided outside the pilot burner, and the low-pressure injection hole has a fuel concentration on the pilot burner side and a fuel concentration on the opposite side of the pilot burner inside the premixed gas circulation passage. It is preferable to be provided at a position where it is darker than.

  According to this configuration, the fuel concentration on the pilot burner side can be increased in the premixed gas distribution passage. For this reason, since the fuel component of the premixed gas flowing through the premixed gas distribution passage can be burned by the combustion of the pilot burner, the generation of unburned components can be further suppressed.

  In this case, it has a nozzle rod extending along the flow direction of the premixed gas, and a plurality of swirl vanes provided around the nozzle rod at predetermined intervals, and the fuel passage is a nozzle rod The low-pressure injection holes are formed in some of the plurality of swirling blades, and the high-pressure injection holes are the other of the plurality of swirling blades. It is preferable to be formed on the swirl vane of the part.

  According to this configuration, when the fuel pressure in the fuel passage is low, the fuel can be injected from the swirl vanes in which the low pressure injection holes are formed. On the other hand, when the fuel pressure in the fuel passage is high, the fuel can be injected from the swirl vanes in which at least the high-pressure injection holes are formed. When the fuel pressure in the fuel passage is high, it is preferable that the fuel is injected from the swirl vane formed with the high pressure injection hole and the swirl vane formed with the low pressure injection hole. For this reason, since a swirl | wing blade can be selected according to a fuel pressure among several swirl | wing blades, the density | concentration distribution of the fuel in a premixed gas distribution channel can be made into optimal distribution.

  In this case, the premixed gas circulation passage is provided outside the pilot burner, the low pressure injection hole is formed in the swirl blade provided on the opposite side of the pilot burner among the plurality of swirl blades, and the plurality of high pressure injection holes are provided. Of these swirl vanes, the swirl blades provided on the pilot burner side are preferably formed.

  According to this configuration, when the fuel pressure in the fuel passage is low, fuel is injected from the low pressure injection hole of the swirl vane located on the opposite side of the pilot burner. At this time, the fuel component of the premixed gas moves to the pilot burner side as the premixed gas of the injected fuel and combustion air swirls in the premixed gas distribution passage. For this reason, the concentration distribution of the fuel in the premixed gas distribution passage is such that the concentration of the fuel on the pilot burner side can be made higher than the concentration of the fuel on the opposite side of the pilot burner, thereby forming an appropriate distribution. be able to.

  In this case, it has a nozzle rod extending along the flow direction of the premixed gas, and a plurality of swirl vanes provided around the nozzle rod at predetermined intervals, and the fuel passage is a nozzle rod The low pressure injection hole is formed at the low pressure injection position of each swirl blade, and the high pressure injection hole is formed at a high pressure injection position different from the low pressure injection position of each swirl blade. It is preferable that

  According to this configuration, when the fuel pressure in the fuel passage is low, fuel can be injected from the low pressure injection hole formed at the low pressure injection position in each swirl blade. On the other hand, when the fuel pressure in the fuel passage is high, the fuel can be injected from the high-pressure injection holes formed at least at the high-pressure injection position in each swirl blade. In addition, when the fuel pressure in a fuel passage is high, it is preferable that it is the structure which injects a fuel from the low-pressure injection hole of each swirl blade, and a high-pressure injection hole. For this reason, since the injection position of the fuel in each swirl blade can be selected according to the fuel pressure, the concentration distribution of the fuel in the premixed gas passage can be made an optimum distribution.

  A combustion burner according to the present invention is a premixed gas distribution passage in which a premixed gas in which the fuel nozzle, the fuel nozzle is disposed inside, and the fuel injected from the fuel nozzle and the combustion air are mixed is distributed. And.

  According to this configuration, the concentration distribution of the fuel injected from the fuel nozzle in the premixed gas passage, that is, the distribution of the fuel component in the premixed gas is set to an optimum distribution according to the fuel differential pressure. Can do.

  A gas turbine combustor according to the present invention includes a pilot burner provided in the center and a plurality of the above-described combustion burners arranged around the pilot burner.

  According to this configuration, the premixed gas from the premixed gas distribution passage of the combustion burner can be suitably burned by the combustion of the pilot burner.

  Another gas turbine combustor of the present invention includes a pilot burner provided in the center and a plurality of combustion burners arranged around the pilot burner, each combustion burner including a fuel nozzle for injecting fuel, a fuel The nozzle is disposed inside, and has a premixed gas distribution passage through which a premixed gas in which fuel injected from the fuel nozzle and combustion air are mixed in advance flows. An injection switching mechanism including a low-pressure fuel nozzle to be injected and a high-pressure fuel nozzle to which fuel is injected, and capable of switching injection of fuel from the high-pressure fuel nozzle according to the pressure of the fuel. The mechanism does not inject fuel from the high pressure fuel nozzle when the fuel pressure in the fuel nozzle is low, but injects fuel from the low pressure fuel nozzle while at least when the fuel pressure in the fuel nozzle is high. Characterized in that to inject fuel from the fuel nozzle.

  According to this configuration, when the fuel pressure in the fuel nozzle is low, fuel can be injected from the low pressure fuel nozzle. On the other hand, when the fuel pressure in the fuel nozzle is high, fuel can be injected at least from the high-pressure fuel nozzle. In addition, when the fuel pressure in a fuel nozzle is high, it is preferable that it is the structure which injects a fuel from a low pressure fuel nozzle and a high pressure fuel nozzle. For this reason, since a fuel nozzle can be selected according to the fuel pressure, the fuel concentration distribution can be made an optimal distribution.

  In this case, the number of low-pressure fuel nozzles is preferably less than half the number of the plurality of fuel nozzles.

  According to this configuration, when the fuel pressure is low, the fuel pressure can be increased and the fuel differential pressure can be increased by the amount of fuel injected by a small number of fuel nozzles, so that the fuel can be suitably injected.

  A gas turbine according to the present invention includes the gas turbine combustor described above, and a turbine rotated by combustion gas generated by burning the premixed gas in the gas turbine combustor.

  According to this configuration, since the fuel can be combusted suitably, the turbine can be rotated by the combustion with low NOx.

FIG. 1 is a schematic configuration diagram of a gas turbine according to a first embodiment. FIG. 2 is an enlarged view of the gas turbine combustor of FIG. FIG. 3 is a diagram schematically showing the internal configuration of the gas turbine combustor. FIG. 4 is a diagram showing the arrangement of various burners of the gas turbine combustor. FIG. 5 is a view schematically showing a fuel passage of the gas turbine combustor. FIG. 6 is a diagram showing an ideal fuel concentration distribution when the fuel pressure is low. FIG. 7 is a cross-sectional view showing the state of the main nozzle when the fuel pressure in Example 1 is low. FIG. 8 is a cross-sectional view showing the state of the main nozzle when the fuel pressure in Example 1 is high. FIG. 9 is a cross-sectional view showing the state of the main nozzle when the fuel pressure in Example 2 is low. FIG. 10 is a cross-sectional view showing the state of the main nozzle when the fuel pressure in Example 2 is high. FIG. 11 is a cross-sectional view showing the state of the fuel passage of the gas turbine combustor when the fuel pressure of Example 3 is low. FIG. 12 is a cross-sectional view showing the state of the fuel passage of the gas turbine combustor when the fuel pressure of Example 3 is high.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic configuration diagram of a gas turbine according to a first embodiment. As shown in FIG. 1, the gas turbine 1 includes a compressor 11, a gas turbine combustor (hereinafter referred to as a combustor) 12, a turbine 13, and an exhaust chamber 14, and a generator (not shown) is connected to the turbine 13. Has been.

  The compressor 11 has an air intake 15 for taking in air, and a plurality of stationary blades 17 and a plurality of moving blades 18 are alternately arranged in a compressor casing 16. The combustor 12 is combustible by supplying fuel to the compressed air (combustion air) compressed by the compressor 11 and igniting it with a burner. In the turbine 13, a plurality of stationary blades 21 and a plurality of moving blades 22 are alternately arranged in a turbine casing 20. The exhaust chamber 14 has an exhaust diffuser 23 that is continuous with the turbine 13. A rotor (turbine shaft) 24 is positioned so as to pass through the center of the compressor 11, the combustor 12, the turbine 13, and the exhaust chamber 14, and an end portion on the compressor 11 side is freely rotatable by a bearing portion 25. On the other hand, the end portion on the exhaust chamber 14 side is rotatably supported by the bearing portion 26. A plurality of disk plates are fixed to the rotor 24, the rotor blades 18 and 22 are connected, and a drive shaft of a generator (not shown) is connected to the end on the exhaust chamber 14 side.

  Therefore, the air taken in from the air intake port 15 of the compressor 11 passes through the plurality of stationary blades 17 and the plurality of moving blades 18 and is compressed into high-temperature and high-pressure compressed air. The fuel is burned by supplying a predetermined fuel to the compressed air. The high-temperature and high-pressure combustion gas that is the working fluid generated by the combustor 12 passes through the plurality of stationary blades 21 and the plurality of moving blades 22 constituting the turbine 13 to drive and rotate the rotor 24. Then, the generator connected to the rotor 24 is driven. On the other hand, the exhaust gas that is the combustion gas after driving and rotating the rotor 24 is converted into a static pressure by the exhaust diffuser 23 in the exhaust chamber 14 and then released to the atmosphere.

  FIG. 2 is an enlarged view of the gas turbine combustor of FIG. FIG. 3 is a diagram schematically showing the internal configuration of the gas turbine combustor. FIG. 4 is a diagram showing the arrangement of various burners of the gas turbine combustor. The combustor 12 has a combustor casing 30. The combustor casing 30 includes an inner cylinder 32 disposed inside the outer cylinder 31, and a tail cylinder 33 connected to the tip of the inner cylinder 32, and a center inclined with respect to the rotation axis I of the rotor 24. It extends along the axis S.

  As shown in FIG. 2, the outer cylinder 31 is fastened to a vehicle compartment housing 27 that forms a vehicle compartment 34 into which compressed air from the compressor 11 flows. The base end of the inner cylinder 32 is supported by the outer cylinder 31, and is arranged inside the outer cylinder 31 at a predetermined interval from the outer cylinder 31. A pilot burner 40 is disposed along the central axis S at the center of the inner cylinder 32. Around the pilot burner 40, a plurality of main burners (combustion burners) 50 are arranged in parallel with the pilot burner 40 so as to surround the pilot burner 40 (see FIG. 4). The tail tube 33 has a base end formed in a cylindrical shape and is connected to the tip of the inner tube 32. The transition piece 33 is formed to have a small cross-sectional area and bend toward the tip side, and is open toward the first stage stationary blade 21 of the turbine 13. The transition piece 33 forms a combustion chamber inside.

  As shown in FIG. 3, the pilot burner 40 includes a pilot cone 41, a pilot nozzle 42 disposed inside the pilot cone 41 and along the central axis S, and a pilot provided on the outer periphery of the pilot nozzle 42. And a swirler 43. The main burner 50 includes a burner cylinder 51 and a main nozzle (fuel nozzle) 52 disposed inside the burner cylinder 51 and parallel to the central axis S. Fuel is supplied to the pilot nozzle 42 from a pilot fuel line (not shown) via a fuel port 44 (FIG. 2). Fuel is supplied to the main nozzle 52 from a main fuel line (not shown) via a fuel port 54 (FIGS. 2 and 5).

  In FIG. 2, the high-temperature and high-pressure compressed air from the compressor 11 flows into the passenger compartment 34 around the combustor 12. The compressed air flows outside the tail cylinder 33 and the inner cylinder 32 from the tail cylinder 33 side to the inner cylinder 32 side, and flows into the inner cylinder 32 from the proximal end side of the inner cylinder 32. The compressed air that has flowed into the inner cylinder 32 is mixed with fuel by the pilot burner 40 and the main burner 50 and burned to become combustion gas.

  That is, the compressed air that has flowed into the inner cylinder 32 is mixed with the fuel injected from the main nozzle 52 and flows into the tail cylinder 33 from the burner cylinder 51 as a swirling flow of the premixed gas. For this reason, the burner cylinder 51 functions as a premixed gas distribution passage for supplying the premixed gas toward the tail cylinder 33. Separately, the compressed air flowing into the inner cylinder 32 is swirled by the pilot swirler 43, mixed with the fuel injected from the pilot nozzle 42, and flows into the tail cylinder 33 as premixed air. The premixed gas from the pilot nozzle 42 is ignited and burned by a not-shown seed fire, and is burned into the tail cylinder 33 as combustion gas. At this time, a part of the combustion gas is ejected so as to diffuse into the tail tube 33 with a flame. As a result, the premixed gas flowing into the tail cylinder 33 from the burner cylinder 51 of each main burner 50 is ignited and burned.

  In this way, flame diffusion for stable combustion of the lean premixed fuel from the main nozzle 52 can be performed by performing diffusion flame with the fuel injected from the pilot nozzle 42. Further, by premixing the fuel from the main nozzle 52 and the compressed air with the main burner 50, the fuel concentration is made uniform and NOx can be reduced.

  FIG. 5 is a view schematically showing a fuel passage of the gas turbine combustor. As shown in FIG. 5, a fuel passage L is formed in the gas turbine combustor 12 from the fuel port 54 to the inside of the plurality of main nozzles 52. That is, the fuel passage L is formed by the first member 61 provided with the fuel port 54, the second member 62 provided adjacent to the first member 61, and the plurality of main nozzles 52 attached to the second member 62. Has been. Therefore, the fuel passage L includes a port side fuel passage L1 formed in the first member 61 and a nozzle side fuel passage L2 formed in the main nozzle 52.

  The first member 61 is formed in a columnar shape centered on the central axis S, and a fuel port 54 is provided so as to protrude from a surface opposite to the surface adjacent to the second member 62. A fuel supply device (not shown) is connected to the fuel port 54, and fuel is supplied from the fuel supply device. The first member 61 has an annular port-side fuel passage L1 formed therein. The port side fuel passage L1 communicates with the fuel port 54 and also communicates with the nozzle side fuel passages L2 of the plurality of main nozzles 52. The second member 62 holds a plurality of main nozzles 52.

  Each main nozzle 52 includes a nozzle bar 65 and a plurality of swirl vanes (so-called swirlers) 66 arranged around the nozzle bar 65 at a predetermined interval. The nozzle rod 65 is formed to extend in the same direction as the central axis S, and is arranged in parallel to the central axis S. In the center of the nozzle rod 65, a part of the nozzle side fuel passage L2, that is, a portion of the nozzle side fuel passage L2 on the upstream side in the fuel flow direction is formed. The nozzle rod 65 is attached to the second member 62 at the base end that is upstream in the fuel flow direction. In addition, the nozzle rod 65 is provided with a plurality of swirl vanes 66 at a tip portion which is on the downstream side in the fuel flow direction.

  The plurality of swirl vanes 66 mix the air and the fuel as premixed gas when the air flowing through the burner tube 51 passes, and swirl the premixed gas toward the tail tube 33. Each swirl vane 66 is formed therein with another part of the nozzle-side fuel passage L2, that is, a downstream portion of the nozzle-side fuel passage L2 in the fuel flow direction. Each swirl vane 66 has a plurality of injection holes 71 through which fuel is injected. The injection hole 71 communicates with the nozzle side fuel passage L2. For example, four injection holes 71 are formed. Of the four injection holes 71, the two injection holes 71 are formed on the downstream side in the fuel flow direction and at positions close to the nozzle rod 65 side. The remaining two injection holes 71 are formed on the upstream side in the fuel flow direction and at a position away from the nozzle rod 65.

  Accordingly, when fuel is supplied from the fuel port 54, the fuel is supplied toward the plurality of main nozzles 52 through the port-side fuel passage L <b> 1. When fuel is supplied from the port-side fuel passage L1 to each main nozzle 52, the fuel flows through the nozzle-side fuel passage L2. The fuel flowing through the nozzle side fuel passage L <b> 2 flows from the proximal end side to the distal end side of the nozzle rod 65, and then flows from the nozzle rod 65 toward the swirl vane 66. The fuel that has flowed into the swirl vanes 66 is injected into the burner cylinder 51 through the injection holes 71, and thereby mixed with the air flowing through the burner cylinder 51.

  In the gas turbine combustor 12 configured as described above, the fuel pressure in the fuel passage L changes according to the generator load of the gas turbine 1. That is, in the gas turbine combustor 12, the amount of fuel injected from the injection hole 71 is adjusted to a predetermined ratio. For this reason, if the generator load is increased, the fuel pressure in the fuel passage L is increased by the fuel supply device in order to increase the fuel injection amount. On the other hand, if the generator load is lowered, the fuel pressure in the fuel passage L is lowered by the fuel supply device in order to reduce the fuel injection amount.

  At this time, when the generator load of the gas turbine 1 is low, the gas turbine 1 is started and the partial load operation is performed until the gas turbine combustor 12 ignites until the rated operation is reached. is there.

  Here, when the gas turbine 1 performs rated operation, in the gas turbine combustor 12, the fuel differential pressure that is the difference between the fuel pressure of the main nozzle 52 (fuel passage L) and the pressure in the burner cylinder 51 becomes high. Yes. That is, as the fuel pressure in the fuel passage L increases, the fuel differential pressure also increases. When the fuel differential pressure is high, it is preferable that the fuel concentration distribution in the burner cylinder 51, that is, the distribution of the fuel component of the premixed gas, be formed in a uniform concentration distribution.

  On the other hand, when the gas turbine 1 performs the partial load operation, the fuel differential pressure is low in the gas turbine combustor 12. That is, if the fuel pressure in the fuel passage L is lowered, the fuel differential pressure is also lowered. Here, FIG. 6 is a diagram showing an ideal fuel concentration distribution when the fuel pressure is low. When the fuel differential pressure is low, the fuel concentration distribution on the outflow side of the burner cylinder 51 is preferably formed as shown in FIG. That is, it is preferable that the fuel concentration distribution on the outflow side of the burner cylinder 51 is formed such that the fuel concentration on the pilot burner 40 side is higher than the fuel concentration on the opposite side of the pilot burner 40.

  Therefore, in the first embodiment, in order to form a fuel concentration distribution suitable for the fuel differential pressure, the main nozzle 52 is provided with an injection switching mechanism 75 that operates according to the fuel pressure. Hereinafter, the injection switching mechanism 75 will be described with reference to FIGS. 7 and 8. FIG. 7 is a cross-sectional view showing the state of the main nozzle when the fuel pressure in Example 1 is low. FIG. 8 is a cross-sectional view showing the state of the main nozzle when the fuel pressure in Example 1 is high.

  When the fuel pressure in the fuel passage L is low, the injection switching mechanism 75 injects fuel from the injection holes 71 of some of the swirling blades 66 among the plurality of swirling blades 66, while the fuel pressure in the fuel passage L is high. Fuel is injected from all the injection holes 71 of the plurality of swirl vanes 66. Prior to the description of the injection switching mechanism 75, the plurality of swirl vanes 66 will be specifically described.

  When the fuel pressure is low, the plurality of swirl vanes 66 are divided into swirl vanes 66a that inject fuel and swirl vanes 66b that do not inject fuel. At this time, the injection hole 71 formed in the swirl vane 66a functions as the low pressure injection hole 71a. Moreover, the injection hole 71 formed in the swirl vane 66b functions as the high-pressure injection hole 71b. Among the plurality of swirling blades 66, a part of the swirling blades 66 located on the side opposite to the pilot burner 40 is a swirling blade 66a, and the other swirling blades 66 located on the pilot burner 40 side are The swirl vane 66b is formed.

  For this reason, when the fuel pressure in the fuel passage L is low, the swirl vanes 66a located on the opposite side of the pilot burner 40 inject fuel from the low pressure injection holes 71a. At this time, the premixed gas of the injected fuel and compressed air swirls in the burner cylinder 51, so that the fuel component of the premixed gas moves to the pilot burner 40 side. For this reason, the concentration distribution of the fuel flowing out from the burner cylinder 51 to the tail cylinder 33 is formed in a distribution in which the concentration of fuel on the pilot burner 40 side becomes higher than the concentration of fuel on the opposite side of the pilot burner 40. .

  On the other hand, when the fuel pressure in the fuel passage L is high, fuel is injected from the low pressure injection hole 71a of the swirl vane 66a and the high pressure injection hole 71b of the swirl vane 66b. At this time, the fuel component of the premixed mixture of injected fuel and compressed air is evenly distributed. For this reason, even if the premixed gas swirls in the burner cylinder 51, the concentration distribution of the fuel flowing out from the burner cylinder 51 to the tail cylinder 33 is formed into a uniform concentration distribution.

  The nozzle side fuel passage L2 includes a rod fuel passage La which is a nozzle side fuel passage L2 inside the nozzle rod 65, a low pressure side blade fuel passage Lb which is a nozzle side fuel passage L2 inside the swirl blade 66a, and a rod fuel passage La. And a low pressure side communication passage Lc that communicates with the low pressure side blade fuel passage Lb. The nozzle side fuel passage L2 includes a high pressure side blade fuel passage Ld which is a nozzle side fuel passage L2 inside the swirl blade 66b, and a high pressure side communication passage Le which communicates the rod fuel passage La and the high pressure side blade fuel passage Ld. Have. The low-pressure side communication passage Lc is located upstream of the high-pressure side communication passage Le in the fuel flow direction.

  Next, the injection switching mechanism 75 will be described. The injection switching mechanism 75 includes a partition plate 76, an elastic member 77, and a purge hole 78. The purge hole 78 communicates between the rod fuel passage La and the outside of the nozzle rod 65, and is located downstream of the high-pressure side communication passage Le in the fuel flow direction.

  The partition plate 76 is provided in the rod fuel passage La of the nozzle rod 65. The partition plate 76 is formed in a shape that closes the rod fuel passage La, and is movable along the fuel flow direction of the rod fuel passage La. At this time, the partition plate 76 reciprocates between the downstream side of the low pressure side communication passage Lc and the upstream side of the purge hole 78. That is, the partition plate 76 reciprocates toward the upstream side and the downstream side across the high-pressure side communication passage Le.

  The elastic member 77 is provided between the partition plate 76 and the tip of the rod fuel passage La. That is, the elastic member 77 is provided in a space communicating with the purge hole 78. The elastic member 77 is, for example, a compression spring, one end of which is connected to the partition plate 76 and the other end is connected to the tip of the rod fuel passage La. For this reason, the elastic member 77 urges the partition plate 76 toward the upstream side of the rod fuel passage La. When the fuel pressure is low, the elastic member 77 has a biasing force in the rod fuel passage La such that the partition plate 76 is positioned between the low pressure side communication passage Lc and the high pressure side communication passage Le. On the other hand, when the fuel pressure is high, the elastic member 77 has a biasing force such that the partition plate 76 is positioned between the high-pressure side communication passage Le and the purge hole 78 in the rod fuel passage La. The purge hole 78 allows air to flow between this space and the burner cylinder 51 so as to allow displacement of the space in which the elastic member 77 partitioned by the partition plate 76 is provided.

  As shown in FIG. 7, in the main nozzle 52, when the gas turbine 1 performs the partial load operation, the fuel pressure in the fuel passage L is lower than that in the full load operation. When the fuel pressure in the fuel passage L is low, the elastic member 77 of the injection switching mechanism 75 positions the partition plate 76 between the low pressure side communication passage Lc and the high pressure side communication passage Le. Accordingly, the rod fuel passage La and the low pressure side communication passage Lc communicate with each other, while the rod fuel passage La and the high pressure side communication passage Le are closed. For this reason, the fuel flowing through the rod fuel passage La flows from the rod fuel passage La to the low pressure side blade fuel passage Lb via the low pressure side communication passage Lc. Therefore, fuel is injected only from the low pressure injection hole 71a of the swirl vane 66a among the plurality of swirl vanes 66.

  On the other hand, as shown in FIG. 8, in the main nozzle 52, when the gas turbine 1 performs full load operation, the fuel pressure in the fuel passage L becomes higher than that in the partial load operation. When the fuel pressure in the fuel passage L is high, the elastic member 77 of the injection switching mechanism 75 positions the partition plate 76 between the high-pressure side communication passage Le and the purge hole 78. As a result, the rod fuel passage La communicates with the low pressure side communication passage Lc, and the rod fuel passage La communicates with the high pressure side communication passage Le. Therefore, the fuel flowing through the rod fuel passage La flows from the rod fuel passage La to the low pressure side blade fuel passage Lb through the low pressure side communication passage Lc and from the rod fuel passage La to the high pressure side communication passage Le. It circulates in the side wing fuel passage Ld. Therefore, fuel is injected from the low pressure injection holes 71a of the swirl vanes 66a and the high pressure injection holes 71b of the swirl vanes 66b, that is, from the injection holes 71 of all the swirl vanes 66.

  As described above, according to the configuration of the first embodiment, when the fuel pressure in the fuel passage L is low, the fuel can be injected from the low pressure injection hole 71a. For this reason, the concentration distribution of the fuel in the premixed gas flowing through the burner cylinder 51 can be formed by the fuel injected from the low pressure injection hole 71a. That is, by injecting fuel from the low-pressure injection hole 71a, it is possible to obtain an optimal fuel concentration distribution during operation at a low fuel pressure (for example, during partial load operation with a low fuel differential pressure). On the other hand, when the fuel pressure in the fuel passage L is high, fuel can be injected from the low pressure injection hole 71a and the high pressure injection hole 71b. Therefore, the concentration distribution of the fuel in the premixed gas flowing through the burner cylinder 51 can be formed by the fuel injected from the low pressure injection hole 71a and the high pressure injection hole 71b. That is, by injecting fuel from the low-pressure injection hole 71a and the high-pressure injection hole 71b, it is possible to obtain an optimal fuel concentration distribution during operation at a high fuel pressure (for example, at full load operation with a high fuel differential pressure). . From the above, the fuel concentration distribution in the burner cylinder 51 can be made an optimal distribution according to the fuel differential pressure. For this reason, premixed gas can be combusted suitably and generation | occurrence | production of an unburned component can be suppressed, Therefore Combustion stability improves.

  Further, according to the configuration of the first embodiment, the fuel concentration on the pilot burner 40 side can be increased inside the burner cylinder 51 on the outflow side. For this reason, since the fuel component of the premixed gas that has circulated through the burner cylinder 51 can be burned by the combustion of the pilot burner 40, the generation of unburned components can be further suppressed.

  Further, according to the configuration of the first embodiment, when the fuel pressure in the fuel passage L is low, fuel can be injected from the swirl vanes 66a in which the low pressure injection holes 71a are formed. On the other hand, when the fuel pressure in the fuel passage L is high, fuel can be injected from the swirl blade 66a in which the low pressure injection hole 71a is formed and the swirl blade 66b in which the high pressure injection hole 71b is formed. For this reason, since the swirl vane 66 can be selected according to the fuel pressure among the plurality of swirl vanes 66, the fuel concentration distribution on the outflow side of the burner cylinder 51 can be set to an optimum distribution. .

  In the first embodiment, when the fuel pressure in the fuel passage L is high, fuel is injected from the swirl vane 66a formed with the low pressure injection hole 71a and the swirl vane 66b formed with the high pressure injection hole 71b. The fuel may be injected only from the swirl vanes 66b in which the holes 71b are formed. At this time, when the fuel pressure is high, the injection switching mechanism 75 closes the rod fuel passage La and the low pressure side communication passage Lc, and communicates the rod fuel passage La and the high pressure side communication passage Le. Is preferred.

  Next, the main nozzle 100 according to the second embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 is a cross-sectional view showing the state of the main nozzle when the fuel pressure in Example 2 is low. FIG. 10 is a cross-sectional view showing the state of the main nozzle when the fuel pressure in Example 2 is high. In the second embodiment, only parts different from the first embodiment will be described in order to avoid the description overlapping with the first embodiment. In the main nozzle 52 of the first embodiment, the injection switching mechanism 75 switches the fuel injection of the swirler 66 according to the fuel pressure. In the main nozzle 100 of the second embodiment, the injection switching mechanism 101 switches the fuel injection position in each swirl blade 66 according to the fuel pressure. Prior to the description of the injection switching mechanism 101, the plurality of swirl vanes 66 will be specifically described.

  As shown in FIGS. 9 and 10, in the main nozzle 100 according to the second embodiment, each swirl vane 66 is formed with a plurality of injection holes 71 through which fuel is injected. The injection hole 71 is divided into a low-pressure injection hole 71a that injects fuel and a high-pressure injection hole 71b that does not inject fuel when the fuel pressure in the fuel passage L is low. The low pressure injection hole 71a is formed on the upstream side in the fuel flow direction as compared with the high pressure injection hole 71b. That is, the low pressure injection hole 71 a is formed at a low pressure injection position on the upstream side of each swirl vane 66, and the high pressure injection hole 71 b is formed at a high pressure injection position on the downstream side of each swirl vane 66. For this reason, the low pressure injection hole 71a and the high pressure injection hole 71b are in different positions.

  The nozzle side fuel passage L2 inside the swirl vane 66 is divided into a low pressure side blade fuel passage Lb and a high pressure side blade fuel passage Ld. In the swirl vane 66, the low pressure side blade fuel passage Lb is formed on the upstream side in the fuel flow direction as compared with the high pressure side blade fuel passage Ld. For this reason, the low pressure injection hole 71a communicates with the low pressure side blade fuel passage Lb, and the high pressure injection hole 71b communicates with the high pressure side blade fuel passage Ld. The low pressure side communication passage Lc communicates the rod fuel passage La and the low pressure side blade fuel passage Lb of the swirl blade 66. Further, the high pressure side communication passage Le communicates the rod fuel passage La and the high pressure side blade fuel passage Ld of the swirl vane 66. Note that the low pressure side communication passage Lc is located upstream of the high pressure side communication passage Le in the fuel flow direction, as in the first embodiment.

  Next, the injection switching mechanism 101 according to the second embodiment will be described. The injection switching mechanism 101 includes a partition plate 76, an elastic member 77, and a purge hole 78. In addition, since the partition plate 76, the elastic member 77, and the purge hole 78 are substantially the same as Example 1, description is abbreviate | omitted.

  As shown in FIG. 9, in the main nozzle 100, when the gas turbine 1 performs the partial load operation, the fuel pressure in the fuel passage L is lower than that in the full load operation. When the fuel pressure in the fuel passage L is low, the elastic member 77 of the injection switching mechanism 101 positions the partition plate 76 between the low pressure side communication passage Lc and the high pressure side communication passage Le. Accordingly, the rod fuel passage La and the low pressure side communication passage Lc communicate with each other, while the rod fuel passage La and the high pressure side communication passage Le are closed. For this reason, the fuel flowing through the rod fuel passage La flows from the rod fuel passage La to the low pressure side blade fuel passage Lb via the low pressure side communication passage Lc. Therefore, fuel is injected only from the low pressure injection holes 71a of the plurality of swirl vanes 66.

  On the other hand, as shown in FIG. 10, in the main nozzle 100, when the gas turbine 1 performs full load operation, the fuel pressure in the fuel passage L becomes higher than that in the partial load operation. When the fuel pressure in the fuel passage L is high, the elastic member 77 of the injection switching mechanism 101 positions the partition plate 76 between the high-pressure side communication passage Le and the purge hole 78. As a result, the rod fuel passage La communicates with the low pressure side communication passage Lc, and the rod fuel passage La communicates with the high pressure side communication passage Le. Therefore, the fuel flowing through the rod fuel passage La flows from the rod fuel passage La to the low pressure side blade fuel passage Lb through the low pressure side communication passage Lc and from the rod fuel passage La to the high pressure side communication passage Le. It circulates in the side wing fuel passage Ld. Therefore, the fuel is injected from the low pressure injection holes 71a and the high pressure injection holes 71b of the plurality of swirl blades 66, that is, from the injection holes 71 of all the swirl blades 66.

  As described above, also in the configuration of the second embodiment, when the fuel pressure in the fuel passage L is low, fuel can be injected from the low pressure injection hole 71a. On the other hand, when the fuel pressure in the fuel passage L is high, fuel can be injected from the low pressure injection hole 71a and the high pressure injection hole 71b. For this reason, the fuel concentration distribution in the burner cylinder 51 can be set to an optimum distribution according to the fuel differential pressure. For this reason, premixed gas can be combusted suitably and generation | occurrence | production of an unburned component can be suppressed, Therefore Combustion stability improves.

  Further, according to the configuration of the second embodiment, when the fuel pressure in the fuel passage L is low, the fuel can be injected from the low pressure injection holes 71a of the swirl vanes 66. On the other hand, when the fuel pressure in the fuel passage L is high, fuel can be injected from the low pressure injection hole 71a and the high pressure injection hole 71b of each swirl vane 66. For this reason, since the fuel injection position in each swirl blade 66 can be selected according to the fuel pressure, the fuel concentration distribution in the burner cylinder 51 can be made an optimum distribution.

  In the second embodiment, the injection switching mechanism 101 injects fuel from the low pressure injection hole 71a and the high pressure injection hole 71b of each swirler 66 when the fuel pressure in the fuel passage L is high. You may inject a fuel only from the injection hole 71b. At this time, when the fuel pressure is high, the injection switching mechanism 101 closes the rod fuel passage La and the low pressure side communication passage Lc, and communicates the rod fuel passage La and the high pressure side communication passage Le. Is preferred.

  Next, with reference to FIG.11 and FIG.12, the gas turbine combustor 110 which concerns on Example 3 is demonstrated. FIG. 11 is a cross-sectional view showing the state of the fuel passage of the gas turbine combustor when the fuel pressure of Example 3 is low. FIG. 12 is a cross-sectional view showing the state of the fuel passage of the gas turbine combustor when the fuel pressure of Example 3 is high. In the third embodiment, only parts different from the first embodiment will be described in order to avoid the description overlapping with the first embodiment. In the first and second embodiments, the injection switching mechanisms 75 and 101 are provided in the main nozzles 52 and 100. In the third embodiment, the injection switching mechanism 111 is provided between the port side fuel passage L1 and the nozzle side fuel passage L2 of the fuel passage L of the gas turbine combustor 110.

  As shown in FIGS. 11 and 12, in the gas turbine combustor 110 according to the third embodiment, the injection switching mechanism 111 includes a plurality of main nozzles 52 in the plurality of main burners 50 when the fuel pressure in the fuel passage L is low. While the fuel is injected from some of the main nozzles 52, the fuel is injected from all of the plurality of main nozzles 52 when the fuel pressure in the fuel passage L is high. Prior to the description of the injection switching mechanism 111, the plurality of main nozzles 52 will be specifically described.

  The plurality of main nozzles 52 are divided into a low-pressure main nozzle (low-pressure fuel nozzle) 52a that injects fuel and a high-pressure main nozzle (high-pressure fuel nozzle) 52b that does not inject fuel when the fuel pressure is low. At this time, the injection hole 71 formed in the swirl vane 66 of the low pressure main nozzle 52a functions as the low pressure injection hole 71a. Further, the injection hole 71 formed in the swirl vane 66 of the high-pressure main nozzle 52b functions as the high-pressure injection hole 71b. The number of low-pressure main nozzles 52a is less than half the number of the plurality of main nozzles 52. For this reason, when the plurality of main nozzles 52 are, for example, eight, the number of low-pressure main nozzles 52a is any one of 1-4, and the number of high-pressure main nozzles 52b is 7-4. It is either number. Here, when there are a plurality of low-pressure main nozzles 52a, the plurality of low-pressure main nozzles 52a are provided adjacent to each other.

  Subsequently, the injection switching mechanism 111 according to the third embodiment will be described. The injection switching mechanism 111 is provided in a switching fuel passage L3 formed in the second member 62 between the port side fuel passage L1 of the first member 61 and the nozzle side fuel passage L2 of the high pressure main nozzle 52b. The switching fuel passage L3 communicates with the port-side fuel passage L1 and also communicates with the nozzle-side fuel passage L2.

  The injection switching mechanism 111 includes a partition plate 116, an elastic member 117, and a purge hole 118. The purge hole 118 communicates the switching fuel passage L3 with the outside. At this time, in the switching fuel passage L3, the nozzle side fuel passage L2 is communicated with the upstream side thereof, and the purge hole 118 is communicated with the downstream side thereof.

  The partition plate 116 is provided in the switching fuel passage L <b> 3 of the second member 62. The partition plate 116 is formed in a shape that closes the switching fuel passage L3, and is movable along the fuel flow direction in the switching fuel passage L3. At this time, the partition plate 116 reciprocates between a closed position where the nozzle side fuel passage L2 is closed and an open position where the nozzle side fuel passage L2 communicates with the switching fuel passage L3.

  The elastic member 117 is provided between the partition plate 116 and the downstream end of the switching fuel passage L3. The elastic member 117 is, for example, a compression spring, one end of which is connected to the partition plate 116, and the other end is connected to the downstream end of the switching fuel passage L3. For this reason, the elastic member 117 urges the partition plate 116 toward the upstream side of the switching fuel passage L3. When the fuel pressure is low, the elastic member 117 has a biasing force such that the partition plate 116 is in the closed position in the switching fuel passage L3. On the other hand, when the fuel pressure is high, the elastic member 117 has an urging force that causes the partition plate 116 to be in the open position in the switching fuel passage L3.

  As shown in FIG. 11, in the gas turbine combustor 110 described above, when the gas turbine 1 performs the partial load operation, the fuel pressure in the fuel passage L is lower than that in the full load operation. When the fuel pressure in the fuel passage L is low, the elastic member 117 of the injection switching mechanism 111 positions the partition plate 116 at the closed position. Therefore, the nozzle-side fuel passage L2 and the switching fuel passage L3 of the high-pressure main nozzle 52b are closed by the partition plate 116. Thus, the fuel flowing through the port side fuel passage L1 flows from the port side fuel passage L1 to the nozzle side fuel passage L2 of the low pressure main nozzle 52a. Therefore, fuel is injected only from the low pressure main nozzle 52a among the plurality of main nozzles 52.

  On the other hand, as shown in FIG. 12, in the gas turbine combustor 110 described above, when the gas turbine 1 performs full load operation, the fuel pressure in the fuel passage L is higher than that in partial load operation. When the fuel pressure in the fuel passage L is high, the elastic member 117 of the injection switching mechanism 111 positions the partition plate 116 in the open position. For this reason, the nozzle-side fuel passage L2 of the high-pressure main nozzle 52b and the switching fuel passage L3 are communicated by the partition plate 116. Thus, the fuel flowing through the port side fuel passage L1 flows from the port side fuel passage L1 to the nozzle side fuel passage L2 of the low pressure main nozzle 52a and the nozzle side fuel passage L2 of the high pressure main nozzle 52b. Therefore, fuel is injected from the low pressure main nozzle 52a and the high pressure main nozzle 52b, that is, from all the main nozzles 52.

  As described above, according to the gas turbine combustor 110 according to the configuration of the third embodiment, when the fuel pressure in the fuel passage L is low, fuel can be injected from the low-pressure main nozzle 52a. On the other hand, when the fuel pressure in the fuel passage L is high, fuel can be injected from the low pressure main nozzle 52a and the high pressure main nozzle 52b. For this reason, since the main nozzle 52 can be selected according to the fuel pressure, the concentration distribution of the fuel in the transition piece 33 can be made an optimum distribution.

  In the third embodiment, the injection switching mechanism 111 injects fuel from the low pressure main nozzle 52a and the high pressure main nozzle 52b when the fuel pressure in the fuel passage L is high, but injects fuel only from the high pressure main nozzle 52b. Also good. At this time, when the fuel pressure is high, the injection switching mechanism 111 closes the nozzle-side fuel passage L2 of the low-pressure main nozzle 52a by the partition plate 116, and the nozzle-side fuel passage L2 of the high-pressure main nozzle 52b by the partition plate 116. It is preferable that the switching fuel passage L3 communicate with the switching fuel passage L3.

  In the first to third embodiments, the gas turbine 1 is in a partial load operation when the fuel pressure in the fuel passage L is low, and the gas turbine 1 is in full load operation when the fuel pressure in the fuel passage L is high. However, the present invention is not limited to this configuration. For example, when the fuel pressure in the fuel passage L is low, it is assumed that the gas turbine 1 is operating from ignition (startup) until reaching a partial load that is about 25% of the full load. As a high case, it is good also as a case where the gas turbine 1 is driving | running from the partial load used as about 25% of full load to full load. That is, as long as the fuel concentration distribution suitable for the fuel differential pressure can be formed, the fuel pressure may be high or low in any operation state of the gas turbine 1.

  In the first to third embodiments, the injection switching mechanisms 75 and 111 include the partition plates 76 and 116, the elastic members 77 and 117, and the purge holes 78 and 118. However, the fuel injection is performed according to the fuel pressure. There is no particular limitation as long as the mechanism can be switched.

DESCRIPTION OF SYMBOLS 1 Gas turbine 11 Compressor 12 Gas turbine combustor 13 Turbine 14 Exhaust chamber 16 Compressor casing 20 Turbine casing 23 Exhaust diffuser 24 Rotor 27 Casing housing 31 Outer cylinder 32 Inner cylinder 33 Tail cylinder 34 Casing room 40 Pilot burner 41 Pilot Cone 42 Pilot nozzle 43 Pilot swirler 50 Main burner 51 Burner cylinder 52 Main nozzle 54 Fuel port 61 First member 62 Second member 65 Nozzle rod 66 Swirling blade 71 Injection hole 71a Low pressure injection hole 71b High pressure injection hole 75 Injection switching mechanism 76 Partition Plate 77 Elastic member 78 Purge hole 100 Main nozzle (Example 2)
101 Injection switching mechanism (Example 2)
DESCRIPTION OF SYMBOLS 110 Gas turbine combustor 111 Injection switching mechanism 116 Partition plate 117 Elastic member 118 Purge hole S Center axis L Fuel passage L1 Port side fuel passage L2 Nozzle side fuel passage L3 Switching fuel passage La Rod fuel passage Lb Low pressure side blade fuel passage Lc Low pressure Side communication passage Ld High pressure side blade fuel passage Le High pressure side communication passage

Claims (10)

In a fuel nozzle that injects the fuel into a premixed gas distribution passage through which a premixed gas in which fuel and combustion air are mixed in advance flows.
A fuel passage through which the fuel flows;
A low-pressure injection hole that communicates with the fuel passage and injects the fuel;
A high-pressure injection hole communicating with the fuel passage and through which the fuel is injected;
An injection switching mechanism capable of switching the injection of the fuel from the high-pressure injection hole according to the fuel pressure in the fuel passage,
When the fuel pressure in the fuel passage is low, the injection switching mechanism injects the fuel from the low pressure injection hole without injecting the fuel from the high pressure injection hole, A fuel nozzle that injects the fuel from at least the high-pressure injection hole when the fuel pressure is high. The premixed gas flow passage is provided outside the pilot burner,
The low-pressure injection hole is provided in the premixed gas passage so that the concentration of the fuel on the pilot burner side is higher than the concentration of the fuel on the opposite side of the pilot burner. The fuel nozzle according to claim 1, wherein A nozzle rod extending along the flow direction of the premixed gas;
A plurality of swirl vanes provided at predetermined intervals around the nozzle rod;
The fuel passage is formed from the inside of the nozzle rod to the inside of each swirl blade,
The low-pressure injection hole is formed in some of the swirl blades among the swirl blades,
The fuel nozzle according to claim 1, wherein the high-pressure injection hole is formed in another part of the swirl blades among the plurality of swirl blades. The premixed gas flow passage is provided outside the pilot burner,
The low pressure injection hole is formed in the swirl blade provided on the opposite side of the pilot burner among the swirl blades,
The fuel nozzle according to claim 3, wherein the high-pressure injection hole is formed in the swirl blade provided on the pilot burner side among the plurality of swirl blades. A nozzle rod extending along the flow direction of the premixed gas;
A plurality of swirl vanes provided at predetermined intervals around the nozzle rod;
The fuel passage is formed from the inside of the nozzle rod to the inside of each swirl blade,
The low pressure injection hole is formed at a low pressure injection position of each swirl vane,
The fuel nozzle according to claim 1, wherein the high-pressure injection hole is formed at a high-pressure injection position different from the low-pressure injection position of each swirl vane. A fuel nozzle according to any one of claims 1 to 5,
The fuel nozzle is disposed inside, and includes the premixed gas flow passage through which the premixed gas in which the fuel injected from the fuel nozzle and the combustion air are mixed in advance flows. And burning burner. A pilot burner provided in the center;
A gas turbine combustor comprising: a plurality of combustion burners according to claim 6 arranged around the pilot burner. A pilot burner provided in the center;
A plurality of combustion burners disposed around the pilot burner,
Each combustion burner is
A fuel nozzle for injecting fuel;
The fuel nozzle is disposed inside, and has a premixed gas distribution passage through which a premixed gas in which the fuel injected from the fuel nozzle and the combustion air are mixed in advance flows.
The plurality of fuel nozzles include a low pressure fuel nozzle through which the fuel is injected, and a high pressure fuel nozzle through which the fuel is injected,
An injection switching mechanism capable of switching the injection of the fuel from the high-pressure fuel nozzle according to the fuel pressure,
The injection switching mechanism injects the fuel from the low-pressure fuel nozzle without injecting the fuel from the high-pressure fuel nozzle when the fuel pressure in the fuel nozzle is low, while the fuel in the fuel nozzle A gas turbine combustor that injects the fuel from at least the high-pressure fuel nozzle when the fuel pressure is high.   The gas turbine combustor according to claim 8, wherein the number of the low-pressure fuel nozzles is less than half the number of the plurality of fuel nozzles. A gas turbine combustor according to any one of claims 7 to 9,
A gas turbine comprising: the gas turbine combustor comprising: a turbine that is rotated by combustion gas generated by burning the premixed gas.

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