JP6100295B2 - Fuel nozzle, combustor equipped with the same, and gas turbine - Google Patents

Description

  The present invention relates to a fuel nozzle, a combustor including the fuel nozzle, and a gas turbine.

  In a combustor of a gas turbine, when a small internal pressure fluctuation occurs in the combustor when generating combustion gas, the small internal pressure fluctuation causes a pressure fluctuation in the vicinity of the fuel nozzle. Due to the pressure fluctuation of the fuel nozzle, the flow rate of the fuel supplied from the fuel nozzle fluctuates, and the pressure fluctuation of the fuel nozzle further increases. As a result, combustion vibrations caused by fluctuations in the amount of heat generated by combustion occurred, and the soundness of the combustor components may be impaired by the combustion vibrations.

  Patent Document 1 discloses an invention that suppresses propagation of pressure fluctuations generated in a fuel nozzle upstream of a throttle portion by providing a throttle that reduces the flow area of the fuel inside the fuel nozzle.

Japanese Patent No. 3494753

  However, in the invention disclosed in Patent Document 1, the pressure fluctuation generated in the fuel nozzle propagates between the throttle portion and the fuel nozzle hole, thereby causing a phase difference in the fuel nozzle. Therefore, there has been a problem that the fuel flow rate in the fuel nozzle hole varies.

  This invention is made in view of such a situation, Comprising: It is providing the fuel nozzle which can suppress the increase in the pressure fluctuation of fuel nozzle hole vicinity, a combustor provided with the same, and a gas turbine. is there.

In order to solve the above-mentioned problems, the following means are employed in the fuel nozzle of the present invention, the combustor including the fuel nozzle, and the gas turbine.
That is, a fuel nozzle according to a reference example of the present invention includes a fuel nozzle hole and a flow path portion that supplies fuel to the fuel nozzle hole, and the fuel nozzle includes a gap between the flow path portion and the fuel nozzle. The enlarged flow having a volume that is in the vicinity of the upstream side of the fuel nozzle hole and that is linked to the pressure fluctuation generated in the fuel nozzle hole, and that has a flow path cross-sectional area larger than the flow path cross-sectional area of the flow path portion. A road portion is provided.

  According to this reference example, the enlarged flow path portion has a volume that is linked to the pressure fluctuation of the fuel nozzle hole, so that the phase difference generated between the pressure fluctuation of the enlarged flow path portion and the pressure fluctuation of the fuel nozzle hole is reduced. To do. Therefore, the change in the fuel flow rate in the fuel nozzle hole can be reduced. Therefore, it is possible to suppress an increase in pressure fluctuation generated in the fuel nozzle hole due to a change in the fuel flow rate, and it is possible to prevent the occurrence of combustion vibration.

  Furthermore, the enlarged flow path portion of the fuel nozzle according to the reference example of the present invention is connected to a resonance chamber having a volume for attenuating pressure fluctuation in the enlarged flow path portion.

  According to this reference example, the resonance chamber has a volume that attenuates the pressure fluctuation in the enlarged flow path portion, and therefore the pressure fluctuation in the enlarged flow path portion can be further reduced. Therefore, the change in the fuel flow rate in the fuel nozzle hole can be further reduced. Accordingly, it is possible to suppress an increase in pressure fluctuation that occurs in the fuel nozzle hole due to a change in the fuel flow rate.

  Furthermore, the enlarged flow path portion of the fuel nozzle according to the reference example of the present invention is characterized by including a volume adjusting means capable of adjusting the volume.

  According to this reference example, by adjusting the volume of the enlarged flow path portion, it is possible to optimize the attenuation of the pressure fluctuation in the enlarged flow path portion with respect to the assumed combustion vibration. Can be effectively reduced. Therefore, it is possible to suppress an increase in pressure fluctuation caused in the fuel nozzle hole due to the fuel flow rate.

  Furthermore, the volume adjusting means of the fuel nozzle according to the reference example of the present invention is a porous body inserted into the enlarged flow path portion.

According to this reference example, by adjusting the volume of the porous body, it is possible to optimize the attenuation of the pressure fluctuation in the enlarged flow path section, and the pressure fluctuation in the enlarged flow path section is absorbed by the porous body. Therefore, the change in the fuel flow rate in the fuel nozzle hole can be further reduced. Accordingly, it is possible to suppress an increase in pressure fluctuation that occurs in the fuel nozzle hole due to a change in the fuel flow rate.
In addition, it is preferable that the porous body provided in the enlarged flow path portion has a larger porosity than the filter installed upstream of the fuel nozzle in order to prevent clogging.

  Furthermore, the volume adjusting means of the fuel nozzle according to the reference example of the present invention is a spacer that can be inserted into the enlarged flow path portion.

  According to this reference example, it is possible to easily adjust the volume of the enlarged flow path portion by changing the number of spacers and the insertion depth, and thus it is possible to easily optimize the attenuation of pressure fluctuation in the enlarged flow path portion. A change in the fuel flow rate can be effectively suppressed. Accordingly, it is possible to suppress an increase in pressure fluctuation that occurs in the fuel nozzle hole due to a change in the fuel flow rate.

Further, the fuel nozzle according to the present invention includes a fuel nozzle hole, a flow path portion for supplying fuel to the fuel nozzle hole, an outer cylinder provided with the fuel nozzle hole on the outer periphery of the lower end, and a lower end of the outer cylinder. A fuel nozzle including a plurality of orifices formed between the outer cylinder and the inner cylinder and spaced apart in the longitudinal direction in the interior of the fuel nozzle. Is arranged.
The fuel nozzle according to the present invention is characterized in that a flow path cross-sectional area of the flow path portion is larger than a flow path cross-sectional area of the fuel nozzle hole.

The pressure fluctuation propagated from the fuel nozzle hole to the flow path portion is reduced by the pressure loss of the flow path portion and does not propagate upstream of the flow path portion. Therefore, since the change in the flow rate of the fuel supplied to the fuel nozzle hole is suppressed, an increase in pressure fluctuation generated in the fuel nozzle hole can be suppressed.
Further, the pressure fluctuation propagated from the fuel nozzle hole to the flow path portion is attenuated by a pressure loss caused by a plurality of orifices provided at intervals in the longitudinal direction of the flow path portion. Therefore, as compared with the case where there is no orifice, the length of the flow path portion can be shortened to suppress an increase in pressure fluctuation generated in the fuel nozzle hole.

  A combustor according to the present invention includes any one of the fuel nozzles described above.

  It is possible to suppress an increase in the pressure fluctuation generated in the fuel nozzle hole due to the internal pressure fluctuation of the combustor, and to reduce the fluctuation of the calorific value due to combustion. Therefore, the soundness of the combustor components against the combustion vibration can be maintained.

  A gas turbine according to the present invention includes the combustor described above.

  Since the soundness of the combustor components can be maintained, the reliability of the gas turbine is improved.

  According to the fuel nozzle of the present invention, the pressure fluctuation propagated from the fuel nozzle hole to the flow path portion is reduced by the pressure loss of the flow path portion and does not propagate upstream of the flow path portion. Accordingly, since the change in the flow rate of the fuel supplied to the fuel nozzle hole is suppressed, an increase in pressure fluctuation generated in the fuel nozzle hole can be suppressed, and the occurrence of combustion vibration can be suppressed.

It is a schematic block diagram which shows the combustor of the gas turbine which has the fuel nozzle concerning 1st Embodiment of this invention. It is the perspective view which decomposed | disassembled and showed the combustor shown in FIG. 1 to the fuel nozzle, the inner cylinder, and the tail cylinder. It is a figure which shows 1st Embodiment of this invention by the longitudinal cross-sectional view along the AA part of FIG. 2 which expanded and showed the principal part of the pilot nozzle shown in FIG. 3A and 3B are cross-sectional views taken along the line B-B in FIG. 3 in the flow path portion of the pilot nozzle shown in FIG. 3, where FIG. 3A is a flow path portion formed concentrically, and FIG. It is the figure which showed having been arrange | positioned equally at the inner periphery of the outer cylinder of a nozzle. It is a longitudinal cross-sectional view of the pilot nozzle concerning 1st reference embodiment of this invention. It is a longitudinal cross-sectional view of the pilot nozzle concerning 2nd reference embodiment of this invention. It is a longitudinal cross-sectional view of the pilot nozzle concerning 3rd reference embodiment of this invention. It is a longitudinal cross-sectional view of the pilot nozzle concerning 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the pilot nozzle concerning 3rd Embodiment of this invention. It is a longitudinal cross-sectional view of the pilot nozzle concerning 4th Embodiment of this invention.

[First Embodiment]
Hereinafter, a combustor including a fuel nozzle of a gas turbine and a gas turbine according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
A gas turbine (not shown) having the combustor 10 shown in FIGS. 1 and 2 includes a compressor (not shown) and a turbine (not shown) in addition to the combustor 10. The gas turbine generally includes a plurality of combustors 10, and the air compressed by the compressors and the fuel supplied to the combustors 10 are mixed and burned in each combustor 10 to perform high-temperature combustion. Generate gas. This high-temperature combustion gas is supplied to the turbine to rotate the turbine.

  A plurality of combustors 10 are annularly arranged in the combustor casing 11 (only one is shown in FIG. 1). The combustor casing 11 and the gas turbine casing 12 are filled with compressed air to form a passenger compartment 13. Air that has been compressed by a compressor is introduced into the passenger compartment 13. The introduced compressed air enters the inside of the combustor 10 from an air inlet 14 provided in the upstream portion of the combustor 10. In the inner cylinder 15 of the combustion burner 16 of the combustor 10, the fuel supplied from the combustion burner 16 and the compressed air are mixed and burned. Combustion gas generated by the combustion is supplied to the turbine chamber side through the transition piece 17 of the combustion burner 16, and rotates a turbine rotor (not shown).

In FIG. 2, the combustion burner 16, the inner cylinder 15 of the combustion burner 16, and the tail cylinder 17 of the combustion burner 16 are shown separately.
The combustion burner 16 has a plurality of main combustion burners 18 and one pilot combustion burner 19.
The plurality of main combustion burners 18 are arranged inside the inner cylinder 15 of the combustion burner 16 and so as to surround the periphery of the pilot combustion burner 19.

The pilot combustion burner 19 includes a pilot nozzle and a pilot burner cylinder 32. The pilot burner cylinder 32 is concentric with the pilot nozzle and is disposed so as to surround the tip of the pilot nozzle. For this reason, a ring-shaped air passage is formed between the pilot nozzle tip and the pilot burner cylinder 32, and compressed air flows through the air passage from the upstream side to the downstream side. The pilot nozzle has a plurality of (for example, eight) fuel nozzle holes at its lower end. The fuel injected from each fuel nozzle hole is mixed with compressed air, sent to the inner space of the inner cylinder 15 of the combustion burner 16 and burned.
The main combustion burner 18 mainly includes a main fuel nozzle 21 and a main burner cylinder 22. The main burner cylinder 22 is disposed so as to surround the main fuel nozzle 21. For this reason, an air passage is formed between the outer peripheral surface of the main fuel nozzle 21 and the inner peripheral surface of the main burner cylinder 22, and the compressed air flows through the air passage from the upstream side to the downstream side. . The main fuel nozzle 21 has a plurality of fuel nozzle holes at its lower end. The fuel injected from each fuel nozzle hole is mixed with compressed air, sent to the inner space of the inner cylinder 15 of the combustion burner 16 and burned.

FIG. 3 is a schematic longitudinal sectional view of the pilot nozzle included in the pilot combustion burner shown in FIG.
The pilot nozzle 20 (fuel nozzle) includes an outer cylinder 24 having a plurality of (for example, eight) fuel nozzle holes 23 on the circumference of the lower end, an inner cylinder 25, a large flow path portion 26, A passage portion 27 and an enlarged flow passage portion 28 are provided.
The large flow path portion 26 is located upstream of the flow path portion 27 and is surrounded by the outer cylinder 24 of the pilot nozzle 20. The large flow path portion 26 has a larger volume than the enlarged flow path portion 28.
The flow path portion 27 is formed between the outer cylinder 24 of the pilot nozzle 20 and the inner cylinder 25 accommodated at the lower end of the outer cylinder 24. The flow path portion 27 has such a length that the pressure of the fuel that has passed through is substantially constant and is supplied to the enlarged flow path portion 28. The flow passage cross-sectional area of the flow passage portion 27 is larger than the flow passage cross-sectional area of the fuel nozzle hole 23 and smaller than that of the enlarged flow passage portion 28.
The enlarged flow path portion 28 is provided between the flow path portion 27 and the fuel nozzle hole 23 and in the vicinity of the upstream side of the fuel nozzle hole 23. The enlarged flow path portion 28 is formed in a ring shape between the inner cylinder 25 and the outer cylinder 24 of the pilot nozzle 20. The volume of the enlarged flow path portion 28 has such a size that the ratio between the maximum value and the minimum value of the flow rate of the fuel supplied to the fuel nozzle hole 23 is minimized.

  As shown in FIG. 4A, the flow path portion 27 is formed in a ring shape between the outer cylinder 24 and the inner cylinder 25 of the pilot nozzle 20, and the fuel flows from the upstream side to the downstream side. As shown in FIG. 4B, a plurality of (for example, eight) flow path portions 27 are arranged on the outer periphery of the inner cylinder 25 between the outer cylinder 24 and the inner cylinder 25 of the pilot nozzle 20. May be.

As described above, the pilot nozzle 20 according to the present embodiment has the following operational effects.
The enlarged flow path portion 28 has a volume (a volume linked with a pressure fluctuation of the fuel nozzle hole 23) in which the ratio between the maximum value and the minimum value of the flow velocity of the fuel supplied to the fuel nozzle hole 23 is minimized. Therefore, the phase difference generated between the pressure fluctuation in the enlarged flow path portion 28 and the pressure fluctuation in the fuel nozzle hole 23 is reduced. Therefore, the change in the fuel flow rate in the fuel nozzle hole 23 can be reduced. Therefore, it is possible to suppress an increase in pressure fluctuation that occurs in the fuel nozzle hole 23 due to a change in the fuel flow rate, and to prevent the occurrence of combustion vibration.
Note that the volume of the enlarged flow path portion 28 can be obtained based on the frequency of the internal pressure fluctuation generated in the combustor 10.

  Furthermore, according to the combustor having the pilot nozzle 20 according to the present embodiment, an increase in the pressure fluctuation generated in the fuel nozzle hole 23 due to the fluctuation in the internal pressure of the combustor is suppressed, and the fluctuation of the heat generation amount due to the combustion is suppressed. be able to. Therefore, it is possible to prevent the soundness of the combustor components from being damaged by the combustion vibration.

  Furthermore, according to the gas turbine having the combustor including the pilot nozzle 20 according to the present embodiment, the soundness of the combustor components can be maintained, so that the reliability of the gas turbine is improved.

[First embodiment]
Hereinafter, a first reference embodiment of the present invention will be described with reference to FIG. The configuration of the pilot nozzle and the combustor of the present embodiment is different from that of the first embodiment in that it has a resonance chamber connected to the enlarged flow path portion, and the others are the same. Accordingly, the same components are denoted by the same reference numerals and description thereof is omitted.
The resonance chamber 29 is connected to the enlarged flow path portion 28 in a direction orthogonal to the fuel flow direction. The resonance chamber 29 is formed between the inner cylinder 25 and the outer cylinder 24 of the pilot nozzle 20 at the lower end of the flow path portion 27. The resonance chamber 29 has a volume that attenuates the pressure fluctuation on the upstream side in the enlarged flow path portion 28.

As described above, the pilot nozzle 20 according to the present embodiment has the following operational effects.
Since the resonance chamber 29 has a volume that attenuates the pressure fluctuation in the enlarged flow path portion 28, the pressure fluctuation in the enlarged flow path portion 28 can be further reduced. Therefore, the change in the fuel flow rate in the fuel nozzle hole 23 can be further reduced. Therefore, it is possible to suppress an increase in pressure fluctuation that occurs in the fuel nozzle hole 23 due to a change in the fuel flow rate.
The volume of the resonance chamber 29 can be obtained based on the frequency of the internal pressure fluctuation generated in the combustor.

[Second embodiment]
Hereinafter, a second reference embodiment of the present invention will be described with reference to FIG. The configuration of the pilot nozzle and the combustor of the present embodiment is different from that of the first embodiment in that a porous body is inserted into the enlarged flow path portion, and the other configurations are the same. Accordingly, the same components are denoted by the same reference numerals and description thereof is omitted.
The porous body (capacity adjusting means) 30 is inserted on the upstream side in the enlarged flow path portion 28. The porous body 30 occupies half of the volume of the enlarged flow path portion 28.

As described above, the pilot nozzle 20 according to the present embodiment has the following operational effects.
By adjusting the volume of the enlarged flow path portion 28, the attenuation of the pressure fluctuation of the enlarged flow path portion 28 can be optimized, and the pressure fluctuation of the enlarged flow path portion 28 is absorbed by the porous body 30. The change in the fuel flow rate in the fuel nozzle hole 23 can be effectively reduced. Therefore, it is possible to suppress an increase in pressure fluctuation that occurs in the fuel nozzle hole 23 due to a change in the fuel flow rate.
In addition, the volume which the porous body 30 occupies in the expansion flow path part 28 can be calculated | required based on the frequency of the internal pressure fluctuation which arises in a combustor, About the porosity of the porous body 30, the information obtained by experiment etc. A value based on can be used.

  The porous body 30 provided in the enlarged flow path portion 28 preferably has a larger porosity than a filter (not shown) installed upstream of the pilot nozzle 20 in order to prevent clogging.

[Third Reference Embodiment]
Hereinafter, a third reference embodiment of the present invention will be described with reference to FIG. The configuration of the pilot nozzle and the combustor of the present embodiment is different from that of the first embodiment in that it has a spacer that can be inserted into the enlarged flow path portion, and the others are the same. Accordingly, the same components are denoted by the same reference numerals and description thereof is omitted.
Two spacers (capacity adjusting means) 31 are provided on the inner peripheral side of the outer cylinder 24 of the pilot nozzle 20. The spacer 31 is of a screw-in type that has a thread on the outer periphery, is embedded from the outside of the outer cylinder 24 of the pilot nozzle 20 with a screw, and protrudes into the enlarged flow path portion 28.

As described above, the pilot nozzle 20 according to the present embodiment has the following operational effects.
By changing the number of spacers 31 and the insertion depth, the volume of the enlarged flow passage portion 28 can be easily adjusted, so that attenuation of pressure fluctuations in the enlarged flow passage portion 28 can be easily optimized, and the change in the fuel flow rate is effective. Can be suppressed. Therefore, it is possible to suppress an increase in pressure fluctuation that occurs in the fuel nozzle hole 23 due to a change in the fuel flow rate.
In addition, the value based on the information obtained by experiment etc. can be used for the number of spacers 31 and insertion depth.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. The configuration of the pilot nozzle and the combustor of the present embodiment is different from that of the first embodiment in that it does not have an enlarged flow path portion, and the others are the same. Accordingly, the same components are denoted by the same reference numerals and description thereof is omitted.
The flow path portion 27 is formed between the outer cylinder 24 and the inner cylinder 25 of the pilot nozzle 20, and has a length that can suppress the pressure fluctuation propagated from the fuel nozzle hole 23 due to the pressure loss of the flow path portion 27. ing. The flow path portion 27 communicates with a plurality of (for example, eight) fuel nozzle holes 23 provided on the outer periphery of the lower end of the outer cylinder 24 of the pilot nozzle 20.

As described above, the pilot nozzle 20 according to the present embodiment has the following operational effects.
The pressure fluctuation propagated from the fuel nozzle hole 23 to the flow path portion 27 is reduced by the pressure loss of the flow path portion 27 and does not propagate upstream of the flow path portion 27. Therefore, since the change in the flow rate of the fuel supplied to the fuel nozzle hole 23 is suppressed, an increase in pressure fluctuation generated in the fuel nozzle hole 23 can be suppressed.
As the length of the flow path portion 27, a value based on information obtained through experiments or the like can be used.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIG. The configuration of the pilot nozzle and the combustor of the present embodiment is different from that of the first embodiment in that it does not have an enlarged flow path portion and the flow path portion has a labyrinth shape, and the others are the same. Accordingly, the same components are denoted by the same reference numerals and description thereof is omitted.
The flow path portion 27 is formed between the outer cylinder 24 and the inner cylinder 25 of the pilot nozzle 20, and a plurality of fuel nozzle holes 23 (for example, eight) provided on the outer periphery of the lower end of the outer cylinder 24. Communicating with On the inner periphery of the outer cylinder 24 and the outer periphery of the inner cylinder 25 of the pilot nozzle 20, a labyrinth shape 32 provided with a plurality of throttle pieces is provided.

As described above, the pilot nozzle 20 according to the present embodiment has the following operational effects.
The pressure fluctuation propagated from the fuel nozzle hole 23 to the flow path portion 27 is attenuated by a pressure loss caused by the labyrinth shape 32 of the flow path portion 27. Therefore, compared with the case where there is no labyrinth shape 32, the length of the flow path portion 27 can be shortened to suppress an increase in pressure fluctuation generated in the fuel nozzle hole 23.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG. The configurations of the main combustion burner and the combustor of the present embodiment are different from those of the first embodiment in that they do not have an enlarged flow path part and are provided with orifices in the flow path part, and are otherwise the same. Accordingly, the same components are denoted by the same reference numerals and description thereof is omitted.
The flow path portion 27 is formed between the outer cylinder 24 and the inner cylinder 25 of the pilot nozzle 20, and a plurality of fuel nozzle holes 23 (for example, eight) provided on the outer periphery of the lower end of the outer cylinder 24. Communicating with The flow path portion 27 is provided with three orifices 33, which are throttling mechanisms composed of disk-shaped thin plates, at positions opposite to the inner peripheral side of the outer cylinder 24 and the outer peripheral side of the inner cylinder 25 of the pilot nozzle 20. It has been. The orifices 33 are provided at equal intervals from the upstream side to the downstream side of the flow path portion 27.

As described above, the pilot nozzle 20 according to the present embodiment has the following operational effects.
The pressure fluctuation propagated from the fuel nozzle hole 23 to the flow path portion 27 is attenuated by a pressure loss caused by the orifice 33 provided in the flow path portion 27. Therefore, compared with the case where the orifice 33 is not provided, the length of the flow path portion 27 can be shortened to suppress an increase in pressure fluctuation generated in the fuel nozzle hole 23.
Note that the intervals at which the orifices 33 are installed, the number and the shape of the orifices 33 are obtained by experiments and the like so that pressure fluctuations passing through the orifices 33 can be prevented from propagating upstream of the flow path portion 27 due to pressure loss. Information based values can be used.

  In each of the above embodiments, the pilot nozzle 20 is used as the fuel nozzle. However, the present invention is not limited to this, and may be, for example, the main fuel nozzle 21 (see FIG. 2).

10 Combustor 20 Pilot nozzle (fuel nozzle)
23 Fuel nozzle hole 24 Outer cylinder 25 Inner cylinder 27 Channel portion 28 Expanded channel portion 32 Labyrinth shape 33 Orifice

Claims (4)

A fuel nozzle hole;
A flow path for supplying fuel to the fuel nozzle hole;
An outer cylinder provided with the fuel nozzle hole on the outer periphery of the lower end;
An inner cylinder housed at the lower end of the outer cylinder;
In a fuel nozzle with
The fuel nozzle, wherein the flow path portion is formed between the outer cylinder and the inner cylinder, and a plurality of orifices are arranged in the interior thereof at intervals in the longitudinal direction . The flow path cross-sectional area of the flow path unit, the fuel nozzle of claim 1, wherein greater than the flow path cross-sectional area of the fuel nozzle hole. A combustor comprising the fuel nozzle according to claim 1 . A gas turbine comprising the combustor according to claim 3 .

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