JPH0828872A - Gas turbine combustion device - Google Patents

Abstract

PURPOSE:To provide a gas turbine combustion device in which an excessive occurrence of combustion vibration can be restricted and a stable combustion can be realized with an operating range including a combustion condition capable of reducing the discharged NOx. CONSTITUTION:A premixing burner 90 having a flame holder 3 is installed adjacent to a circulating flow burner 80 and a premixing gas injection port of the premixing burner 90 is provided with a projection 15. As a load at the gas turbine is increased, a rate of fuel supplying amount for the premixing burner is increased to restrict an increasing of the discharged NOx. Even if a flow rate of fuel at the circulating flow burner 80 is substantially varied, a circulation flow of high temperature formed at a downstream side of the projection 15 arranged at an inner circumferential wall surface of a premixing device 4 becomes a flame holding region, so that the flame is stably formed. With such an arrangement as above, combustion at the circulating flow burner can be stably held within all the operating ranges of the gas turbine combustion device and then occurrence of severe combustion vibration can be restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine combustor provided with a diffusion combustion burner that burns fuel and air while mixing them, and a premixed combustion burner that premixes and burns fuel and air. In particular, the present invention relates to a gas turbine combustor having an annular premixed combustion burner so as to surround the diffusion combustion burner or a gas turbine combustor having a plurality of premixed combustion burners around the diffusion combustion burner.

[0002]

2. Description of the Related Art Gas turbines must operate over a wide range of output power from large load changes from start-up to rated load. Therefore, stable combustion is one of the essential requirements of the gas turbine combustor from start to rated load even if the operating conditions such as the air flow rate and the fuel flow rate change significantly.

On the other hand, in order to reduce the amount of NOx emitted from the gas turbine combustor, there is a strong demand for a combustion method capable of suppressing the generation of NOx.

As a combustion method with a small amount of exhausted NOx, there is premixed combustion in which fuel and air are premixed before combustion reaction and then burned. This is by premixed combustion,
This is to prevent the combustion flame temperature from rising locally.

Generally, the amount of NOx produced increases exponentially as the combustion flame temperature increases. Therefore, the combustion flame temperature can be lowered and the NOx emission amount can be reduced by increasing the proportion of air to dilute the premixed air-fuel mixture.
Therefore, in recent years, the ratio of lean premixed combustion has been increasing in response to the ever-increasing demand for low NOx. However, lean premixed combustion generally has a narrower stable combustion range than diffusion combustion and is prone to misfire. Therefore, it is necessary to skillfully combine diffusion combustion and lean premixed combustion in order to achieve low NOx while ensuring stable combustion.

As a means for stably performing the premixed combustion, it is effective to dispose a flame stabilizer at the premixed gas jet port and hold the flame with the circulation flow of the combustion gas that can flow in the downstream of the flame stabilizer. Is. Therefore, a combustor in which a premixed burner with a flame stabilizer and a pilot burner by diffusion combustion are combined has been proposed. These are described in JP-A-4-103906 or JP-A-5-157239.

[0007]

A problem in a combustor in which a premixed burner with a flame stabilizer and a pilot burner by diffusion combustion are combined is a problem. When the flame relationship between the two becomes unstable, combustion oscillation occurs. It is to be.

The conditions under which combustion oscillation occurs are extremely complicated. If the conditions for jetting the diffusion combustion fuel and the premixed gas, the supply ratio of the premixed combustion fuel and the diffusion combustion fuel, etc. are changed,
The condition that the flame becomes unstable appears and combustion oscillation occurs. In order to suppress NOx emission due to combustion, it is desirable to reduce the proportion of the diffusion combustion fuel as much as possible. However, when combustion vibration occurs under such conditions, the vibration level becomes extremely large, and the NOx concentration is substantially low. Cannot be used as a combustor.

In a conventional combustor in which a premixing burner with a flame stabilizer and a pilot burner by diffusion combustion are combined, the fuel supply ratio of diffusion combustion is large, and the combustion chamber for diffusion combustion is premixed combustion. By separately arranging it on the upstream side of the combustion chamber for the engine, the interference between the premixed flame and the diffusion flame is reduced. However, in the burner having such a structure, the flow rate of combustion air for diffusion combustion suppresses NOx generation from the diffusion combustion flame, and also prevents locally generated high temperature portions from damaging structural materials. Therefore, the fuel must be distributed according to the maximum value of the fuel supply for diffusion combustion.

Therefore, the proportion of the flow rate of combustion air distributed to the premixer is reduced, the proportion of lean premixed combustion cannot be increased, and there is a limit to the reduction of exhausted NOx. If the ratio of the fuel for diffusion combustion is reduced in such a combustor, the combustion gas temperature due to diffusion combustion decreases, and it becomes difficult to propagate the flame to the premixed flame formed downstream of the diffusion combustion chamber. Therefore, from this point as well, there is a limit to the reduction of NOx emissions.

Therefore, there is a combustor structure in which a premixing burner with a flame stabilizer and a pilot burner by diffusion combustion are adjacent to each other, and a part of combustion air of fuel supplied to the pilot burner is shared with the combustion air of the premixing burner. Proposed.
In this case, if the gas jetted from the pilot burner is swirled, it can be better mixed with the air in the premix burner. Here, only the combustion air may be applied to the swirl flow, or both the combustion air and the fuel may be applied. In the former case, the fuel is jetted into the combustion chamber in a straight flow. In this combustor configuration, the flow rate of the combustion air used only for the combustion of the pilot burner can be reduced, so that the lean premixed combustion ratio can be increased and the exhausted NOx can be reduced.

On the other hand, however, in the combustor, as shown in the conventional example of FIG. 12, a condition in which combustion oscillation occurs violently appears depending on the ratio of fuel supplied to both burners, and the gas turbine combustor is operated. It was a big problem that hindered the reliability and reliability.

An object of the present invention is to provide a gas turbine combustor having a diffusion combustion burner and a premixed combustion burner with a wide range of air flow rate and fuel flow rate in order to increase lean premixed combustion ratio and reduce exhaust NOx. The purpose of the present invention is to provide a gas turbine combustor that does not generate combustion vibrations even when changed by the above and can perform stable combustion.

[0014]

According to the present invention, there is provided a diffusion combustion burner provided with an annular air nozzle so as to surround a fuel nozzle for diffusion combustion, and a premixed combustion burner arranged so as to surround the diffusion combustion burner. In a gas turbine combustor comprising: a swirl vane for generating a swirling air flow in the vicinity of an ejection port of an air nozzle provided in the diffusion combustion burner,
A flame stabilizer is provided near the downstream side of the premixed gas injection port of the premixed combustion burner to deflect the flow of the premixed gas of fuel and air to form a circulating flow of combustion gas on the downstream side to hold a flame, A feature is provided at the tip of the premixed gas jet outlet of the premixed combustion burner, which is provided with a projection portion which projects inward from the peripheral edge of the jet port and narrows the flow path of the premixed gas mixture.

Further, a gas turbine combustor comprising a diffusion combustion burner provided with an annular air nozzle so as to surround the fuel nozzle for diffusion combustion, and a premixed combustion burner arranged so as to surround the diffusion combustion burner. In the above method, another fuel nozzle is provided in the air nozzle of the diffusion combustion burner to make the burner a diffusion-premixed mixed burner, and swirl premixed at the air-fuel premixed gas jet port of the diffusion-premixed mixed burner. A swirl vane for generating an air flow is provided, and the flow of the premixed fuel and air is deflected in the vicinity of the downstream side of the premixed gas jet of the premixed combustion burner to form a circulation flow of combustion gas on the downstream side to form a flame. A flame stabilizer for holding the premixed gas is provided, and a projection portion is provided at the tip of the premixed gas ejection port of the premixed combustion burner to project inward from the peripheral edge of the ejection port to narrow the flow path of the premixed gas mixture. To.

The most reliable method of stably burning a gas turbine combustor is to clearly define a region where combustion starts, that is, a flame holding region, in the combustor. In the present invention, as a means for forming the flame holding region, a swirl flow is applied to combustion air or a premixed mixture of combustion air and fuel, and a backflow region is formed by the swirling flow to form a flame holding region, and A flame stabilizer is disposed at the outlet of the premixer that ejects the mixed gas, and the method is used in which the backflow region formed in the downstream of the flame stabilizer is used as the flame stabilizing region. In this case, the burner for generating the swirling flow and the premixing burner equipped with the flame stabilizer are arranged adjacent to each other. Then, in order to suppress combustion oscillation in a wide range of operating conditions of both burners, a protrusion protruding inward from the peripheral edge of the jet outlet is provided at the tip of the premixed jet outlet of the premixer burner, and Narrow the flow path.

Here, the projection for narrowing the diameter of the premixed gas outlet has an angle with respect to the flow of the premixed gas that does not form a large stagnation region of the premixed gas on the upstream side of the projection. It is desirable to have. Further, it is desirable that a turbulent flow promoting body composed of a plurality of minute protrusions is provided on the surface of the protrusion to disturb the flow of the premixed gas, whereby the metal temperature of the protrusion can be reduced.

In the present invention, it is desirable that the diffusion combustion burner is provided at the center of the combustor, and the premix combustion burner is provided so as to surround the diffusion combustion burner. As one means for this, it is desirable to provide an annular premixed combustion burner concentrically around the diffusion combustion burner. Further, it is desirable to provide a plurality of premixed combustion burners around the diffusion combustion burner at substantially equal intervals. In the case of providing an annular premixed combustion burner around the diffusion combustion burner, an air passage for supplying a part of the combustion air flowing through the diffusion combustion burner is provided in the partition wall that separates the premixed combustion burner and the diffusion combustion burner. It is desirable to cool both burners.

Even when a diffusion-premixed co-firing burner is provided instead of the diffusion combustion burner, it is desirable to provide an annular or a plurality of premixed combustion burners, as in the case where the diffusion combustion burner described above is provided. Further, in the case of providing an annular premixed combustion burner around the diffusion-premixed mixed burner,
It is desirable to cool both burners by providing a premixed gas flow path for supplying a part of the premixed gas flowing through the diffusion-premixed mixed burner to the partition wall that separates both burners.

Here, the cooling air and the mixed gas of air and fuel which are jetted from the cooling air passage provided in the partition wall are jetted in the jet direction substantially the same as the jet direction of the premixed gas flowing through the premix burner. Is desirable.

[0021]

A gas turbine combustor in which a diffusion combustion burner with a swirler or a diffusion-premixed co-firing burner and a premixed burner with a flame stabilizer are arranged adjacent to each other is, as shown in the conventional example of FIG. 12, both burners. Depending on the ratio of fuel supplied to the fuel cell, conditions under which combustion oscillations occur violently appear. The behavior of such combustion oscillations is that the combustion reaction progresses due to the region (flame formation region) where the fuel supplied from the burner with the swirl advances and the fuel supplied from the premix burner with the flame stabilizer. It is considered that the interaction with the region (flame formation region) plays an important role. That is, although the flame by the burner with a swirler is stable by itself, the flame formation region is changed depending on the ratio of the fuel supplied to the burner with a swirl, which causes fluctuation. It is considered that when the phase of fluctuation coincides with the phase of change in combustion reaction of the burner with flame stabilizer, a large combustion vibration is generated corresponding to the natural frequency of the combustor.

Therefore, in order to suppress the combustion oscillation, it is sufficient to reduce the rate at which the phase of the flame fluctuation of the burner with a swirler changes depending on the proportion of fuel supplied to the burner with a swirl. In order to achieve this, the present inventors believe that it is effective to prevent the flame formation region by the burner with a swirler from changing significantly at least under the condition of operating in combination with the burner with a flame stabilizer. It was

The present invention has been completed on the basis of such an idea, and suppresses the occurrence of intense combustion vibration as shown in the conventional example in FIG. 12 and stabilizes in the entire operating range of the gas turbine combustor. It is intended to provide a combustor capable of achieving stable combustion.

In the present invention, as a means for preventing the flame forming region of the burner with a swirler from greatly changing, the premixed gas jet port of the premixed burner with a flame stabilizer adjacent to the burner with a swirler has the jet port. Protrusions are provided that project from the surroundings toward the inside and interfere with the flow of the premixed gas. It is desirable that the protrusion has a ring shape or a shape in which a part of the ring is lost. When the protrusion is arranged, the flow of the premixed gas is accelerated along the protrusion, and a stable circulation vortex is formed in the wake of the protrusion. Since the fuel and air ejected from the burner with a swirler and the premixed gas and the combustion gas ejected from the premixer burner with a flame stabilizer are entrained in the circulation flow, a stable flame is formed here. region,
That is, a flame holding region is formed. What is important here is that the premixed gas and combustion gas ejected from the premixing burner with flame stabilizer are also entrained in the circulation flow. Due to this action, the circulation flow is stable even under the condition that the flow rate of fuel supplied to the premixing burner with flame stabilizer is overwhelmingly larger than the flow rate of fuel supplied to the burner with swirler. The flame-holding region becomes large, and the occurrence of severe combustion vibration can be suppressed.

The projections provided at the premixed gas jet port of the premixed burner with a flame stabilizer, which obstruct the flow of the premixed gas, are
It is desirable to have an angle with respect to the flow of the premixed gas that does not form a large stagnation region of the premixed gas on the upstream side of the protrusion. For example, when the protrusion has an angle of 90 degrees with respect to the flow of the premixed gas, a large stagnation area is formed on the upstream side of the protrusion. In this state, if the combustion state becomes unstable due to fluctuations in the fuel flow rate or the like, the flame is formed in the stagnation area, and there is a high possibility of backfire in the premixer. In order to prevent this, it is sufficient to suppress the generation of a large stagnation area on the upstream side of the protrusion, and in the present invention, the protrusion is formed at an angle of 90 degrees or less with respect to the flow of the premixed gas. Is desirable. The formation of a large stagnation region of the premixed gas is influenced by the shape of the premixed gas flow passage of the premixed burner and the flow rate of the premixed gas, and therefore the angle of the protrusion with respect to the premixed gas flow cannot be unconditionally determined. However, it is usually desirable to set it to 80 degrees or less. It is also desirable to sharpen the tip of the protrusion to prevent the flame from adhering to the portion.

In the present invention, the wall surface of the protrusion is
It is desirable to dispose a turbulence promoting body composed of a plurality of minute protrusions. By arranging the turbulence promoting body, a small vortex is formed in the wake of the turbulence promoting body by the airflow of air or premixed air, and the boundary layer is destroyed. As a result, the heat transfer coefficient increases, and heat transfer between the premixed gas stream and the flame forming region side of the protrusion, which has a high temperature adjacent to the flame, is promoted. Usually, the temperature of the premixed airflow is about 100 to 400 ° C., and the maximum temperature of the structural member forming the protrusion is 500.
It reaches ~ 800 ° C. If the heat transfer between the two is promoted, the temperature of the premixed gas flow rises. The higher the airflow temperature, the easier it is to start combustion, and thus more stable combustion can be achieved.
Further, promoting heat transfer between the flame forming region side of the protrusion and the airflow also prevents generation of a high temperature portion in the protrusion. Here, the turbulent flow promoting body promotes heat transfer by means of a vortex formed in the subsequent flow and a minute nonuniform flow of the flow, and it is desirable that the height is 0.1 mm or more and 1 mm or less. If the height of the turbulence promoting body is set to 1 mm or more, the scale of eddy currents and drift will be increased and the effect of the turbulence promoting body will be hindered. Also, the height of the turbulence promoting body is 0.1 mm.
In the following cases, the effect of generating turbulence cannot be exhibited. Therefore, by setting the height of the turbulence promoting body to 0.1 mm or more and 1 mm or less, the heat transfer performance of the turbulence promoting body can be maintained at a high level.

Further, in the present invention, a cooling air flow passage for cooling the burner structure is provided at the boundary between the burner with a swirler and the premixing burner with a flame stabilizer, and the cooling air flow passage flows through the cooling air flow passage. It would be desirable to add additional means of supplying fuel to the cooling air. Generally, in a burner with a swirler, since the fluid is spread in the circumferential direction by swirling, in order to avoid interference with the gas ejected from the premix burner with a flame stabilizer, the premix air outlet of the premix burner and the swirl It is desirable to provide a distance between the swirling fluid jet of the burner with a heater. In this case, a circulating flow is formed near the partition between the premixer outlet and the swirling fluid jet outlet of the burner with a swirl, that is, the partition that separates both burners, and the structure becomes hot. Therefore, cooling air is supplied to the structure portion so that the metal temperature of the structure does not exceed the allowable value of the material. In the present invention, however, the cooling air flow path for this purpose is provided with at least the swirler. It is desirable to provide it in the partition wall part which separates the burner and the premix burner. Further, it is desirable to provide means for supplying fuel to the cooling air flowing through the cooling air flow path. A projection is provided around the premixed gas jet outlet of the premixing burner so as to narrow the premixed gas flow path, and a circulation flow is formed in the downstream of the projection, so that the cooling air flow path is formed in the cooling air flow path. When the fuel is supplied together with the cooling air, the gas in the circulation flow becomes hotter and forms a more stable flame holding region. Therefore, the effect of suppressing the occurrence of combustion vibration can be further strengthened.

Here, the air or the mixed gas of air and fuel ejected from the cooling air passage provided in the partition wall of the burner with a swirler and the premix burner is almost the same as the ejection direction of the premixed gas of the premix burner. When jetted in the jet direction, a stable circulation vortex is formed between the jet stream of the mixed gas of air and fuel jetted from the cooling air flow path and the jet stream of the premixed gas. If the former jet flow is too close to the premixed gas jet flow side, stable circulation vortex formation is hindered, and if it is too far away, the flame holding region of the burner with a swirler may be disturbed.

By incorporating such a gas turbine combustor, the reliability of the gas turbine and the gas turbine power plant is improved.

[0030]

【Example】

[Embodiment 1] An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a gas turbine combustor according to this embodiment, and FIG. 2 is a side view of FIG. In the combustor, a burner with a swirler (hereinafter, referred to as a swirl flow burner) 80 having swirl vanes 2 is arranged on a central axis,
A premix burner 90 having a ring-shaped flame stabilizer 3 and a premixer 4 is arranged on the outer periphery thereof. Swirl burner 80
Includes a fuel nozzle 1 at the center and an annular air nozzle surrounding the fuel nozzle 1. At the tip of the jet nozzle of the air nozzle, the flow passage is narrowed by a flow passage reducing member 13 protruding from the peripheral edge toward the upstream side, and the narrowed air flow passage is provided with a swirl vane 2. Air 20 compressed by a compressor (not shown) is supplied to the combustor. The fuel 21 is supplied to the fuel nozzle 1 of the swirl flow burner 80, and the combustion air 2 passing through the swirl vanes 2
It is jetted into the swirling flow 30 formed by 0A. On the other hand, the fuel is supplied from the fuel nozzle 10 into the premixer 4, and mixed with air to be ejected from the inner and outer circumferences of the ring-shaped flame stabilizer 3 as the premixed gas 22. The fuel nozzle 10
As shown in FIG. 2, a plurality of them are provided.
The arrangement is not particularly limited. Further, in the present embodiment, the ring-shaped flame stabilizer 3 is used and is arranged at the outlet of the premixer 4 by the fixed plate 11, but if the circulation flow 40 can be formed in the downstream of the flame stabilizer, The shape and arrangement are not particularly limited. The air 20 is used as the combustion air 20A and is also distributed as the cooling air 23. The cooling air 23 is
After the combustion gas contacts and cools the wall surface of the flow path reducing member 13 that has a high temperature, it is ejected to the combustion region. Further, a ring-shaped projection 15 is provided on the inner peripheral wall surface of the premixer 4 on the swirl flow burner 80 side.

FIG. 3 is an enlarged cross-sectional view of a part of the combustor shown in FIG. Since the circulation flow 40 of high temperature combustion gas is formed in the wake of the ring-shaped flame stabilizer 3,
This is the flame holding region, and the premixed gas 2 along the circulation flow 40
Two burn. Regarding the swirl flow burner 80, a circulation flow 50A formed along the wall surface of the flow path reducing member 13 between the air jet port 2 from the swirl vane 2 and the premixer 4, and a reverse flow region 50B due to the swirl flow, Fuel jets 18A, 18B
The more jetted fuel and air are mixed, and combustion progresses.

FIG. 4 shows the flow around the projection 15 arranged on the inner wall surface of the premixer 4. A circulation vortex 60 is formed in the wake of the projection 15. The circulation vortex 60 has the swirl burner 8
Since it is the flow of the combustion gas due to the air flow 24 of the fuel and air and the premixture 22 from 0, the temperature is sufficiently high, and the flame 70 is formed along this. The combustion oscillation as shown in the conventional example of FIG. 12 is largely caused by the fluctuation of the flame formed at the boundary between the air flow 24 and the premix air flow 22 by the swirl burner 80. Therefore, according to this embodiment, the flame 7
Since 0 is stably formed, the combustion oscillation can be reduced to the level shown in the embodiment of the present invention shown in FIG.

Here, it is a basic requirement that the projection 15 is an obstacle to the premixed air flow 22, but the projection 15 is configured so that a large stagnation area cannot be formed in the premixer 4 on the other hand. There must be. This is because the protrusion 15 is arranged at the outlet of the premixer 4, and the stagnation area formed in this portion may cause flashback due to slight flame fluctuation, which may burn the combustor. . Therefore, the protrusion 15 is modified as shown in the following embodiments.

Similar to FIG. 4, FIG. 5 shows the cross-sectional shape of the projection 15 arranged on the inner wall surface of the premixer 4. Here, when the angle between the wall surface 15A of the projection 15 and the main flow direction of the premixed gas 22 is θ, the θ is preferably in the range of 10 ° to 80 °. When θ becomes 80 ° or more, a stagnation area 75 formed by the flow along the wall surface 4A of the premixer 4
Becomes larger and the possibility of flashback increases. Further, when θ is 10 ° or less, the circulation vortex 60 formed in the wake of the projection 15 becomes weak and the flame holding performance of the flame 70 deteriorates. When θ is in the range of 10 ° to 80 °, flame holding performance can be maintained while preventing flashback. When θ becomes large, the flame 7 of the protrusion 15
The thickness of the structure of the formation part of 0 becomes small. In this case, if the wall surfaces 15C and 15D of the protrusion 15 on the combustion gas side are angled as shown in FIG. 5, the thickness of the structure of the tip portion 15D can be increased and the strength can be increased.

FIG. 6 shows the wall surface 15A of the protrusion 15 of FIG.
The wall surfaces are angled from the wall surfaces 15A and 15B. With this configuration, the stagnation area 75 due to the premixed airflow 22A can be made extremely small. Moreover, since the thickness of the structure of 15B is increased, the strength of this portion can be increased.

FIG. 7 shows a structure in which a turbulent flow promoting body 16 which is a minute projection is further provided on the surface of the wall surface 15A in addition to the structure of the projection 15 of FIG. The turbulence promoting body 16 has a cross-sectional shape as shown in FIG. 8 and a height H of 0.1 mm or more and 1 mm or less,
The interval L is 4 to 20 times H. Here, the depth direction may be continuous or may have a shape in which a part is separated. Circulation vortices 76 are formed in the wake of the turbulence promoting body 16 and destroy the boundary layer formed on the surface of the wall surface 15A, so that heat transfer between the projection 15 and the premixed gas flow 22A is promoted. Therefore, the temperature of the air flow 22A rises, so that the formation of the flame 70 becomes stable. In addition, it is possible to suppress an increase in the metal temperature of the protrusion 15 that is in contact with the high-temperature circulating vortex 60. The effect of the turbulence promoting body 16 is not significantly different from that of the shape other than that shown in FIG. 8, for example, the sectional shape is trapezoidal or triangular.
There is no particular limitation including the arrangement of No. 6.

An embodiment of the operation of the gas turbine combustor in which the individual effects described above are integrated will be described with reference to FIG.

The fuel 21 is supplied from the fuel nozzle 1 to the swirl burner 80 when the gas turbine is started up or accelerated. Both the air flow rate and the fuel flow rate greatly change at the time of start-up and speed-up, but the swirling flow 30 by the swirl vanes 2 stably forms a diffusion flame, so there is no misfire. As the gas turbine enters load operation and the load is increased, the supply amount of the fuel 21 is increased.

At the stage when the load is further increased, the fuel is supplied from the fuel nozzle 10 in the premixer 4 to supply the premixed gas 22.
And introduced into the premix burner 90. A ring-shaped flame stabilizer 3 is arranged at the outlet of the premixer 4, and the flame is stably formed by the circulation flow 40 formed in the subsequent flow.

In this embodiment, the ring-shaped projection 1 is formed on the inner peripheral side wall surface of the premixer 4 adjacent to the swirl flow burner 80.
5 are arranged. NO in the process of reaching the rated load
In order to suppress x, the fuel supply amount to the premixed burner 90 having a small NOx generation amount is increased, and the fuel supply amount to the swirl flow burner 80 having a relatively large NOx generation amount is reduced.
In the conventional burner, as shown in the conventional example of FIG. 12, the flame became unstable in the process of changing the fuel supply amount of the swirl flow burner, and violent combustion oscillation was generated. On the other hand, in the present embodiment, as shown in the embodiment of the present invention in FIG. 12, the circulation flow that can be the wake of the ring-shaped protrusion becomes the flame holding region, so that the combustion vibration is violently generated. There is no such thing.

According to this embodiment, even if the fuel supply amount to the swirl flow burner changes in the process of reaching the rated load, the effect of suppressing combustion oscillation can be suppressed.

[Second Embodiment] FIG. 9 shows another embodiment of the present invention. Also in this embodiment, the swirl flow burner 80 according to the present embodiment and the premixing burner 90 provided with the premixer having the flame stabilizer at the outlet are arranged adjacent to each other and the projections 15 are provided on the inner wall of the premixer 4. The operational effects such as the formation of the flame holding region are similar to those of the first embodiment. The difference from the first embodiment is that the fuel nozzle 16 is arranged on the upstream side of the swirl burner 80 so that the fuel 17 can be supplied. Here, the number of fuel nozzles 16 is not particularly limited. Further, the supply of the fuel 17 from the fuel nozzle 16 can be started at any time from the start of the gas turbine to the rated load. In this case, the flow rate of fuel from the fuel nozzle 1 may be controlled to decrease in accordance with the increase in the supply amount of the fuel 17.

The fuel ejected from the fuel nozzle 17 partially passes through the swirl vanes 2 and is ejected together with the fuel from the fuel nozzle 1 into the combustion region. The remaining fuel is cooling air 2
Swirl flow burner 8 of premixer 4
It is jetted into the combustion area along the 0-side wall surface. As shown in FIG. 4, the projection 15 is arranged on the inner wall surface of the premixer 4, and the circulation vortex 60 is formed in the subsequent flow.
Here, the mixed gas of air and fuel passing through the cooling air passage 14 is ejected to the combustion region so as not to hinder the formation of the circulation vortex 60. Since the fuel supplied from the fuel nozzle 16 is mixed with the cooling air 23, the combustion of the flame along the circulation vortex 60 can be further promoted. Therefore, the flame holding in that portion can be strengthened, and the combustion reaction between the fuel from the swirl flow burner and the air 24 can be stabilized, so that the occurrence of severe combustion oscillation can be suppressed. Further, according to the present embodiment, a part of the fuel 17 is mixed with air in the process of reaching the swirl vanes 2 and becomes a premixed gas and is ejected to the combustion region. Therefore, since the supply amount of the fuel amount 21 by diffusion combustion can be reduced by the supply amount of the fuel 17, the NOx emission amount can be reduced.

According to this embodiment, it is possible to suppress the occurrence of severe combustion oscillation and reduce the NOx emission amount.

[Third Embodiment] Another embodiment according to the present invention is shown in FIGS. FIG. 11 is a view of a part of the combustor of FIG. 10 viewed from the downstream side. In the combustor of this embodiment, the premixing burner 9 with the flame stabilizer 3 is provided around the swirl burner 80.
0A, 90B, 90C, 90D and 90E are arranged. FIG. 10 shows the burners 90A, 80, 90 of FIG.
It is the figure which connected the cross section of D.

Premix burners 90A, 90B, 90C, 9
In 0D and 90E, the flame stabilizer 3 is fixed to the outlet of the premixer 4 by the support plate 11. The fuel is supplied from the fuel nozzle 10, mixed with the air 20, and ejected as a premixed gas 22 to the combustion region. A protrusion 15 is arranged on the inner wall surface of the premixer 4.

In the swirl flow burner 80, a swirl flow of air and fuel jetted from the fuel nozzle 1 is formed by the swirl vanes 2 and burned. In the case of the present embodiment, the swirling flow burner 80 is operated at the time of starting the gas turbine, and the fuel is sequentially supplied to the premixing burners 90A, 90B, 90C, 90D, and 90E as the load increases, and is operated. During this time, NO emissions
In order to reduce x, the fuel flow rate ratio of the swirl flow burner 80 decreases, but due to the effect of the projections 15 arranged on the inner peripheral wall surface of the premixer 4, the swirl flow burner 80 and the premix burner 90A, The flame formed at the boundaries of 90B, 90C, 90D, and 90E burns stably, and no noticeable combustion oscillation occurs.

According to this embodiment, there is an effect that a gas turbine combustor having a plurality of premixed burners can stably perform combustion.

[0049]

EFFECTS OF THE INVENTION According to the present invention, it is possible to stably secure the flame holding region for holding the combustion flame formed at the boundary between the swirling flow burner and the premixing burner with flame stabilizer, and to reduce the NOx emission amount. In a wide operating range including conditions, it is effective in preventing the occurrence of severe combustion vibration.

By incorporating the gas turbine combustor of the present invention, a gas turbine and a gas turbine power plant having excellent combustion stability are provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a gas turbine combustor according to an embodiment of the present invention.

FIG. 2 is a diagram of the burner configuration of FIG. 1 viewed from a downstream side of a combustor.

FIG. 3 is an enlarged view of a part of FIG.

FIG. 4 is an enlarged view of a part of FIG.

FIG. 5 is a partial cross-sectional explanatory view of a burner according to an embodiment of the present invention.

FIG. 6 is a partial cross-sectional explanatory view of a burner according to an embodiment of the present invention.

FIG. 7 is a partial cross-sectional explanatory view of a burner according to an embodiment of the present invention.

FIG. 8 is a diagram showing the shape and dimensions of the turbulence promoting body of FIG. 7 and the circulation vortices formed thereby.

FIG. 9 is a cross-sectional view of a gas turbine combustor according to another embodiment of the present invention.

FIG. 10 is a sectional view of a gas turbine combustor according to still another embodiment of the present invention.

11 is a view of a part of the burner configuration of FIG. 10 viewed from the downstream side of the combustor.

FIG. 12 is a graph showing an example of a situation of occurrence of combustion vibration.

[Explanation of symbols]

1, 10 ... Fuel nozzle, 2 ... Swivel blade, 3 ... Flame stabilizer,
4, 22 ... Premixer, 13 ... Flow path reducing member, 14 ... Cooling air flow path, 15 ... Protrusion, 20 ... Air, 21 ... Fuel, 23
... cooling air, 24 ... fuel and air flow, 30 ... swirl, 40,50,60,76 ... circulating vortex, 70 ... flame, 7
5 ... stagnation area, 80 ... swirl flow burner, 90 ... premix burner.

Front page continuation (72) Inventor Shigeru Shodohata 3-1-1, Saiwaicho, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Yasutaka Komatsu 3-1-1, Saiwaicho, Hitachi, Ibaraki Hitachi Ltd., Hitachi Works (72) Inventor Haruo Urushitani 1-1-1, Sachimachi, Hitachi, Ibaraki Prefecture Hitachi Ltd., Hitachi Works (72) Inventor Nobuyuki Iizuka 3-chome, Sachimachi, Hitachi City, Ibaraki Prefecture No. 1-1 Hitachi Ltd., Hitachi Plant (72) Inventor Tadataka Murakami 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd., Hitachi Research Laboratory

Claims (10)

[Claims] 1. A gas turbine combustor comprising: a diffusion combustion burner having an annular air nozzle outside a diffusion combustion fuel nozzle; and a premixed combustion burner disposed around the diffusion combustion burner. A swirl vane for generating swirling air flow is provided in the vicinity of the jet nozzle of the air nozzle of the combustion burner, and the flow of the premixed mixture of fuel and air is deflected in the vicinity of the downstream side of the premixed gas jet outlet of the premixed combustion burner. A flame stabilizer for forming a circulating flow of combustion gas to hold a flame is provided on the flow side, and the premixed gas jet tip of the premixed combustion burner projects inward from the periphery of the premixed gas burner. A gas turbine combustor, which is provided with a protrusion that narrows the flow path of the gas turbine combustor. 2. A gas turbine combustor comprising a diffusion combustion burner having an annular air nozzle surrounding a diffusion combustion fuel nozzle, and a premixed combustion burner arranged around the diffusion combustion burner. Another fuel nozzle is provided in the air nozzle of the diffusion combustion burner, and the burner is used as a diffusion-premixed co-firing burner, and a swirling premixed air flow is supplied to the air-fuel premixed gas injection port of the diffusion-premixed cofiring burner. A swirl vane for generating the premixed combustion burner is provided, and the flow of the premixed mixture of fuel and air is deflected in the vicinity of the downstream side of the premixed gas injection port of the premixed combustion burner to form a circulation flow of combustion gas on the downstream side to hold a flame. A gas stabilizer provided with a flame stabilizer, which is provided at the tip of the premixed gas ejection port of the premixed combustion burner and which projects inward from the peripheral edge of the ejection port and narrows the flow path of the premixed gas. -Bin combustor. 3. The pre-mixed gas burner according to claim 1, wherein the projection provided on the pre-mixed gas injection port of the pre-mixed combustion burner has an angle so as not to form a large stagnation region of the pre-mixed gas on the upstream side of the projection. A gas turbine combustor characterized by having a mixture flow. 4. The micro-mixing burner according to claim 1, wherein a surface of the projection portion of the pre-mixed combustion burner, which is in contact with the pre-mixed gas, is in contact with the pre-mixed gas. A gas turbine combustor, characterized in that a turbulent flow promoting body which is a projection is provided. 5. The premixed combustion burner according to claim 1, further comprising an annular premixed combustion burner so as to surround the diffusion combustion burner, wherein a part of the air flowing through the diffusion combustion burner is separated by a partition wall separating both burners. A gas turbine combustor, characterized in that it is provided with an air flow path supplied as. 6. The premixed gas according to claim 2, further comprising an annular premixed combustion burner surrounding the diffusion-premixed co-firing burner, and the partition wall separating both burners flows through the diffusion-premixed co-firing burner. A gas turbine combustor having a flow path for supplying a part of the gas turbine combustor. 7. The jet nozzle of an air nozzle provided in the diffusion combustion burner according to claim 1, wherein an annular flow passage of the jet nozzle is narrowed toward the inner peripheral side from the peripheral edge of the jet nozzle toward the inner side. A gas turbine combustor, wherein an overhanging air flow path reducing member is provided, and the swirl vane is provided at an air ejection port narrowed by the member. 8. The premixed gas jet port of the diffusion-premixed co-firing burner according to claim 2, wherein the annular flow passage of the jet port is narrowed toward the inner peripheral side from the peripheral edge of the jet port toward the inner side. A gas turbine combustor characterized in that an overhanging flow path reducing member is provided, and the swirl vane is provided at the premixed gas jet outlet narrowed by the member. 9. The gas turbine combustor according to claim 1, wherein the diffusion combustion burner is arranged in the center, and the diffusion combustion burner is surrounded and a plurality of the premixed combustion burners are arranged around the diffusion combustion burner. . 10. The diffusion-premixing co-firing burner according to claim 2, wherein the diffusion-premixing co-firing burner is arranged in the center, the diffusion-premixing co-firing burner is surrounded, and a plurality of the premixing combustion burners are arranged around the diffusion-premixing co-firing burner. And a gas turbine combustor.