JP2001012740A - Gas turbine combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine combustion device to reduce incurring of a pressure loss at a premixer, sufficiently mix together fuel and air at a short premixture distance, and further sufficiently prevent the damage of a combustor due to discharge of flame to the outside of the premixer even when ignition is effected at the internal part of the premixer and flame is present. SOLUTION: A premixer 4 to mix together air and fuel is provided in a spot situated upper stream from a combustion chamber 2. The premixer comprises a gas flow passage 20 through which combustion air and mixture gas flow; and a fuel nozzle 5 situated in the gas flow passage. Fuel injected through a fuel nozzle is mixed with air in the premixer, and the air-fuel mixture is fed in the combustion chamber 2. In a so formed gas turbine combustion device, an air flow direction varying means 40 to change a flow of air flowing through the premixer into the direction of the fuel nozzle hole of the fuel nozzle is situated in a spot situated upper stream from the fuel nozzle hole of the fuel nozzle 5 and on the gas flow passage wall of the premixer. Further, a gas flow passage throttle means 30 to throttle the sectional area of the gas flow passage is situated in a spot situated downstream from the fuel nozzle hole of the fuel nozzle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine combustion apparatus, and more particularly, to a gas turbine combustion apparatus provided with a premixer for mixing air and fuel upstream of a combustion chamber, wherein fuel injected from a fuel nozzle is provided in the premixer. And a gas turbine combustion device formed to be mixed with air and supplied to a combustion chamber.

[0002]

2. Description of the Related Art The amount of nitrogen oxide (NOx) emitted when fuel is burned in a gas turbine engine is premixed combustion, that is, air and fuel are mixed in a premixer, and then the mixture is supplied to a combustion chamber. In the case of the premixed combustion in which the fuel is supplied and burned, it is possible to greatly reduce the diffusion combustion in which the fuel and the air are mixed and burned. Accordingly, gas turbine engines employing this premixed combustion are increasing in order to cope with recent NOx emission regulations.

On the other hand, this premixed combustion has a characteristic that a condition range such as a fuel-air ratio (weight ratio between fuel and air) and a flow velocity that can perform stable combustion is narrower than diffusion combustion. For this reason, many proposals have been made on a combustor structure for realizing premixed combustion that satisfies this condition in a gas turbine engine, a control method for the gas turbine engine, and the like. The following describes a premixer to be used.

[0004] In order to efficiently reduce NOx emissions in premixed combustion, it is necessary to make the method of mixing fuel and air uniform. Further, in premixed combustion, if a flame returns to the inside of the premixer, the combustor may be damaged. Therefore, it is necessary to adopt a structure for preventing a backfire.

[0005] For this reason, there has been proposed a premixing method and a premixer as a means for realizing the premixing method with the main object of uniform mixing of fuel and air and prevention of flashback. These are described, for example, in Japanese Patent Publication No. Hei.
187909, JP-A-6-272882, JP-A-6-241457, JP-A-6-2848,
It is disclosed in JP-A-9-303776.

[0006]

The premixer is provided upstream of the combustion chamber and mixes fuel and air. However, when used in a gas turbine combustor, it is necessary to satisfy several requirements. There is. For example, in premixed combustion for burning a premixed gas that is a mixed gas of fuel and air,
Generally, the more uniform the concentration distribution of the premixed gas supplied to the combustion region, the lower the NOx. Thus, swirling the air and increasing the length of the premixer are used to achieve a uniform concentration distribution. However, if these methods are excessively applied, the pressure loss in the premixer becomes large, and conversely, the characteristics are deteriorated. Therefore, the swirling strength is considered in consideration of the pressure loss range allowed for the gas turbine combustor. It is necessary to determine the pod premixer length. It is therefore desirable to be able to mix fuel and air with the shortest possible premixing distance.

Further, as a characteristic required for the premixer, it is important to prevent a flashback in which a flame flows back from the combustion zone into the premixer. For this reason, the flow velocity of the premixed gas injected into the combustion region is increased by narrowing the flow path at the outlet of the premixer. On the other hand, if fuel and air are mixed in a region where the air flow velocity in the premixer is large, the mixing characteristics deteriorate.Therefore, the air flow velocity in the fuel and air mixing start area is smaller than the injection velocity of the premixed gas into the combustion area. Is also preferably small.

As described above, even if the premixer has taken measures such as increasing the flow velocity of the premixed gas into the combustion region by narrowing the flow path at the outlet of the premixer, for some reason the premixer is not used. May ignite within. For example, if combustibles having a low ignition temperature are mixed in the fuel system or the air system, the temperature of the air flowing into the combustor from the compressor of the gas turbine is usually about 300 to 500 ° C., which leads to ignition. The possibilities are plentiful.

Further, when such ignition occurs in the premixer, local pressure fluctuations are induced, which may cause local flow velocity fluctuations to draw the flame into the premixer. If such a phenomenon occurs and the premixed gas continuously burns inside the premixer, the combustor may be damaged, and the gas turbine may not be able to operate stably for a long period of time. is there.

The present invention has been made in view of the above, and it is an object of the present invention to reduce the pressure loss in a premixer, to sufficiently mix fuel and air in a short premixing distance, This type of gas turbine combustion device is capable of swiftly discharging the flame to the outside of the premixer even if a fire is ignited or a flame is present inside the gas turbine, thereby sufficiently preventing damage to the combustor. Is to provide.

[0011]

That is, the present invention comprises a premixer for mixing air and fuel upstream of a combustion chamber,
The premixer includes a gas flow path through which combustion air and a mixed gas flow, and a fuel nozzle disposed in the gas flow path, and fuel injected from the fuel nozzle is supplied with air through the premixer. And a gas turbine combustion device formed to be supplied to the combustion chamber, wherein a premixer is provided upstream of a fuel injection port of the fuel nozzle and on a gas flow path wall surface of the premixer. Air flow direction changing means for changing the flow of air flowing through the fuel nozzle in the direction of the fuel injection port of the fuel nozzle is provided, and the cross-sectional area of the gas flow path is located downstream of the fuel injection port of the fuel nozzle. A narrowed gas flow path narrowing means is provided to achieve the intended purpose.

According to the present invention, a fuel nozzle for diffusion combustion for performing diffusion combustion or a fuel nozzle for combined diffusion / premix combustion capable of performing both diffusion combustion and premix combustion is disposed in the central portion on the upstream side of the combustion chamber. In addition, a plurality of premixers for mixing air and fuel are arranged around the fuel nozzle for diffusion combustion or the fuel nozzle for combined diffusion / premixed combustion, and each of the premixers is used for mixing combustion air and mixed gas. A gas flow path that circulates, comprising a premixed fuel nozzle disposed in the gas flow path, fuel injected from the premixed fuel nozzle is mixed with air in the premixer, and the combustion chamber In the gas turbine combustion device configured to be supplied, the premixer is provided on the inner wall of the gas passage on the side of the fuel nozzle for diffusion combustion or the fuel nozzle for combined use of diffusion / premix combustion and the premixer. On the inner wall surface upstream of the fuel injection port of the fuel nozzle, air flow direction changing means for changing the flow of air flowing through the gas flow path in the direction of the fuel injection port of the premixed fuel nozzle is provided, Gas flow restricting means for narrowing the cross-sectional area of the gas flow path is provided downstream of the fuel injection port of the fuel nozzle.

In this case, the air flow direction changing means is formed by a projection projecting into the flow passage on a part of the air flow path wall surface of the premixer. Further, the projections are formed so as to form a streamline in the direction of air flow, and are formed integrally with the gas flow path wall surface. Further, the flow path restricting means is formed by an entire circumference projection so as to restrict the entire circumference of the air flow path wall surface of the premixer.

[0014] Further, the entire circumference of the premixer, which narrows the cross-sectional area of the flow path, is formed so as to form a streamline in the direction of air flow, and is formed integrally with the wall of the gas flow path. Things. Further, the projection height of the entire circumference projection and the projection for changing the flow direction of the air are both formed to be substantially the same, and both are formed so as to be continuous in the flow direction of the air.

That is, in the gas turbine combustion apparatus formed as described above, the flow of air flowing through the premixer is applied to the gas flow path wall upstream of the fuel injection port of the fuel nozzle. Air flow direction changing means for changing the direction of the injection port is provided, and gas flow path narrowing means for narrowing the cross-sectional area of the gas flow path is provided downstream of the fuel injection port of the fuel nozzle, The flow direction of the air that has flowed into the gas passage of the premixer is changed by the air flow direction changing means, that is, the flow at the premixer inlet is directed toward the fuel nozzle, that is, the longitudinal direction of the gas passage. Since an air flow is formed at an angle to the direction, turbulence of the air flow occurs near the fuel nozzle, and the fuel injected from the fuel injection port (nozzle injection hole) of the fuel nozzle can travel in a relatively short distance. mixture To promote.

[0016] Further, since the throttle means for narrowing the cross-sectional area of the gas flow path is provided on the downstream side of the injection hole of the fuel nozzle, even if the fuel is ignited in the premixer for some reason, the fuel is not affected. Since the fuel injected from the nozzle orifice ignites after being mixed with air, the flow velocity is high in a region where the premixed gas can ignite, and the flame cannot propagate to the upstream of the premixer. Also, even if the premixed gas ignites before flowing into the throttle portion, the ignited flame hits the wall and is cooled, so that the flame cannot be stably held and is quickly discharged out of the premixer. With such a configuration, the pressure loss in the premixer is small, the fuel and the air can be sufficiently mixed with a short premixing distance, and a fire or a flame exists inside the premixer. However, this flame is quickly discharged out of the premixer, and damage to the combustor can be sufficiently prevented.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows the gas turbine combustion device in cross section. 1 is a gas turbine combustor, 2 is a combustion chamber, 3 is a fuel nozzle for diffusion combustion, 4 is a premixer, and 5 is a premixed fuel nozzle. Reference numeral 60 denotes an air compressor for compressing combustion air, and reference numeral 61 denotes a gas turbine driven by combustion gas of a combustor.

The gas turbine combustor 1 includes a diffusion burner 7 having a fuel nozzle 3 for injecting fuel 10 for diffusion combustion into the combustion chamber 2 and a fuel nozzle for injecting fuel 11 for premix combustion to the premixer 4. A premix burner 8 having a 5 is provided. That is, a diffusion-combustion fuel nozzle 3 for performing diffusion combustion is disposed at the upstream central portion of the combustion chamber 2, and a plurality of premixers 4 for mixing air and fuel around the diffusion-combustion fuel nozzle are provided. Are located.

Each premixer is provided with a gas passage through which the combustion air and the mixed gas flow, and a premixed fuel nozzle 5 disposed in the gas passage, and the fuel injected from the premixed fuel nozzle is provided. The premixer is configured to be mixed with air and supplied to the combustion chamber.

In operation, first, the combustion air 12 is
The air is supplied from the air compressor 60 to the combustor 1 and is supplied to the diffusion burner 7.
And is supplied to the premixed combustion burner 8 side.
On the side of the diffusion burner 7, the combustion air 12 and the fuel from the fuel nozzle 3 are swirled and agitated by the swirler 6 to form a circulation vortex of the combustion gas in the combustion chamber 2, resulting in a stable diffusion flame. On the other hand, the combustion air 12 flowing into the premixer 4 side is
The fuel is mixed with the fuel injected from the fuel nozzle 5, and after mixing, is injected into the combustion chamber 2 and burns. At the outlet of the premixer 4, an annular flame stabilizer 9 for keeping the flame is arranged.

FIG. 2 shows a view of the gas turbine combustor of FIG. 1 as viewed from the downstream side of the flow of the combustion gas. However, in FIG. 2, for the sake of explanation, the annular flame stabilizer 9 of FIG.
Is not listed. The pre-mixer 4 has a cylindrical air flow path (gas flow path) 20 in which a plurality of fuel nozzles 5 are arranged in a circumferential shape.

FIG. 1B shows an enlarged cross section of the premixer 4 in the axial direction. The pre-mixer 4 has an air flow direction changing means for changing the flow direction of air, that is, upstream of the fuel injection port (fuel injection hole) 21 of the fuel nozzle 5 and on the gas flow path wall surface of the pre-mixer. Gas flow path 2
The flow of air flowing through the inside of the fuel nozzle 21 is
A projection 40 for changing the direction is provided.

The projection 40 is formed on a part of the gas flow path wall surface so as to protrude into the flow path, and is formed so as to form a streamline in the flow direction of air. In addition, this projection 4
In the case of this premixer, the position of the gas flow path in the circumferential direction of 0 is a return flow structure in which the air 12 is inverted and flows in at the inlet section 50. It seems to be better to provide it on the gas flow path wall on the diffusion burner 7 side. The projection 40 may be formed by fixing a projection formed in advance to the gas flow path wall. However, it is preferable to form the projection 40 integrally with the gas flow path wall.

With such a configuration, the incoming combustion air 12
In the region near the premixer inlet 50 of the fuel nozzle 5, the direction becomes the inner circumferential side of the cylindrical air flow path 20. And flows toward the outer peripheral side, that is, flows toward the fuel injection holes 21 of the nozzle. As a result, a turbulence in the flow occurs near the fuel injection hole of the fuel nozzle 5.

Gas flow path narrowing means (throttle structure) 30, 31 for narrowing the flow area of the cylindrical air flow path 20 of the premixer 4 are provided immediately downstream of the injection hole 21 of the fuel nozzle 5. Have been. The throttle structures 30 and 31 are formed by full-circumferential projections so as to throttle the entire circumference of the air flow path wall surface.
Further, its end is formed so as to form a streamline in the direction of air flow. Of course, this projection may be formed integrally with the gas flow path wall surface, or may be manufactured separately and fixed later.

Although the entire shape of the throttle structure is not particularly limited, it is desirable that the increase in the flow velocity due to the throttle structure be 10% or more. The upper limit of the flow velocity is determined by the pressure loss due to the throttle structure or the effect of the jet velocity at which the premixed gas is supplied to the combustion chamber on the premixed combustion characteristics such as blowout and combustion vibration.

Further, the distance from the fuel injection hole to the throttle structure has an effective range depending on the shape of the premixer, the fuel-air ratio of the premixed gas, the flow rate, and the like.
It is desirable to set in the range of 0 to 120 mm. If the distance is less than 20 mm, the fuel will be ejected from the fuel nozzle orifice to a region where the air flow velocity is high, so that the mixing characteristics of fuel and air will deteriorate. On the other hand, if this distance is 12
When it is 0 mm or more, the possibility that the flame is held between the fuel nozzle injection hole and the throttle structure increases.

In response to such an air flow, the fuel injected from the injection hole 21 of the fuel nozzle is promoted to mix by the turbulence of the flow generated near the fuel nozzle 5, and the throttle structures 30, 3
Flow into one part. Although the flow speed of the gaseous mixture of fuel and air is accelerated by the throttle structures 30 and 31, the mixing state is not significantly impaired, and the increase in exhaust NOx due to the installation of the throttle structures 30 and 31 is small.

Here, assuming that the flame is ignited in the premixer 4 for some reason, the flame ignited by the premixed gas has a high flow velocity downstream of the throttle structures 30 and 31, It is discharged out of the vessel 4. Fuel injection hole 2
In this embodiment, even if ignition occurs between the throttle structure 1 and the throttle structures 30 and 31, the throttle structure 3 is located immediately downstream of the injection hole 21.
Because of the presence of 0 and 31, the flame collides with the wall of the throttle structure and is cooled, the flame cannot be stably present during this time and is therefore quickly discharged out of the premixer 4, ie into the combustion chamber.

According to the present embodiment, in the premixer having a cylindrical air flow path, even if the flame is ignited in the premixer for some reason without greatly impairing the mixing characteristics of the fuel and air, the flame is generated. The combustor can be quickly discharged to the outside of the premixer, so that an increase in NOx can be suppressed and the combustor can be prevented from being damaged.

FIGS. 5, 6 and 7 show another embodiment of the present invention. As in FIG. 1B described above,
FIG. 2 shows an axial cross section of the premixer 4 and shows a relationship between a means for changing a part or the whole of the air flow 12 in the radial direction of the premixer 4 and the throttle structures 30 and 31.

First, FIG. 5 shows that throttle structures 30, 31 for reducing the cross-sectional area of the flow path of the premixer 4 are provided on the inner and outer peripheral walls of the cylindrical air flow path 20, and the positions of the throttle structures 30, 31 on the inner and outer peripheral walls are determined by the air. Is shifted in the flow direction. That is, the protrusion heights of the circumferential projections for reducing the cross-sectional area of the flow path of the premixer and the projections for changing the flow direction of the air are substantially the same, and both are formed in the air flow direction. It is formed so as to be continuous.

With such a configuration, of the aperture structure,
By the throttle structure 31 arranged on the upstream side, the air 12
Some or all of the flow can be changed more in the radial direction near the tip of the fuel nozzle 5. Therefore,
Disturbance of the flow near the fuel nozzle 5 can be increased in a region near the injection hole 21 of the fuel nozzle 5, and mixing with the fuel can be promoted.
According to this embodiment, since the turbulence of the air near the fuel nozzle can be increased, there is an effect that the mixing of the air and the fuel can be promoted.

FIGS. 6 and 7 show an embodiment in which the air 12 flows into the premixer 4 in a straight flow with respect to the premixer having the return flow structure of FIG. In any case, the protrusion 40 provided on the inner peripheral side of the premixer 4
Part or all of the flow of the air 12 changes in the radial direction of the premixer 4. Here, the difference between FIG. 6 and FIG.
6 is provided at the inlet of the premixer 4 in FIG. 6, and is provided slightly upstream from the injection hole 21 of the fuel nozzle 5 in FIG. Of course, in any of the embodiments, the protrusion 4
0 may be provided on the outer peripheral side of the premixer. According to this embodiment, even when the air flows into the premixer in a straight flow, the turbulence of the air near the fuel nozzle can be increased.
This has the effect of promoting the mixing of air and fuel.

FIGS. 3 and 4 show another embodiment of the present invention. In the present embodiment, a diffusion burner 7 for injecting fuel from the diffusion fuel nozzle 3 and mixing and burning with the air swirled by the swirler 6 is placed at the center of the combustor 1, and eight ducts are formed around the diffusion burner 7. Is disposed to burn the premixed gas ejected into the combustion chamber 2. However, the number of duct-shaped premixers 4 is not limited. Also, the diffusion burner 7 may be a combined diffusion / premix combustion burner capable of performing both diffusion combustion and premix combustion.

Although two fuel nozzles 5 are provided in the air flow path 20 of the duct-shaped premixer 4, the number of fuel nozzles is not limited. A projection 40 is provided at the inlet 50 of the duct-shaped premixer 4. A part of the flow of the air 12 is turned by the projections 40 in the radial direction of the premixer 4. Immediately downstream of the fuel injection holes 21, throttle structures 30 and 31 are provided.
Is installed.

With these structures, as in the embodiment shown in FIG. 1, the mixing is promoted by the turbulence of the flow generated near the fuel nozzle. It is quickly discharged out of the premixer 4. Also in this embodiment, any of the premixer structures shown in FIGS. 1, 5, 6, and 7 can be applied.

According to the present embodiment, even in a combustor using a duct-shaped premixer, even if the mixture is ignited in the premixer for any reason without significantly impairing the mixing characteristics of fuel and air, the flame is not affected. Can be quickly discharged out of the premixer.
Therefore, there is an effect that damage to the combustor can be prevented while suppressing an increase in NOx.

As described above, in the gas turbine combustor formed as described above, the flow of the air flowing through the premixer is formed on the gas flow path wall upstream of the fuel injection port of the fuel nozzle. Air flow direction changing means for changing the direction of the fuel injection port of the fuel nozzle is provided, and gas flow path narrowing means for reducing the cross-sectional area of the gas flow path is provided downstream of the fuel injection port of the fuel nozzle. Therefore, part of the air that has flowed into the gas passage of the premixer flows toward the fuel nozzle, that is, turbulence of the air flow occurs near the fuel nozzle, and the fuel injection port of the fuel nozzle The fuel ejected from the (nozzle injection hole) promotes mixing at a relatively short distance, and a throttle means for narrowing the cross-sectional area of the gas flow path is provided downstream of the injection hole of the fuel nozzle. For some reason Even if the fuel is ignited in the premixer, the fuel injected from the fuel nozzle orifice will ignite after being mixed with air, so the flow velocity is large in the region where the premixed gas can ignite, and the flame It cannot propagate upstream of the premixer, and even if the premixed gas ignites before flowing into the throttle, the ignited flame hits the wall and is cooled, so the flame cannot be held stably.
It is quickly discharged out of the premixer, so that the fuel and air can be sufficiently mixed with a short premixing distance,
Even if a flame is ignited inside the premixer or a flame is present, the flame is quickly discharged out of the premixer, and damage to the combustor can be prevented.

[0040]

As described above, according to the present invention, the pressure loss in the premixer is small, the fuel and air can be sufficiently mixed with a short premixing distance, and the inside of the premixer can be reduced. Even if a fire is ignited or a flame is present, it is possible to obtain a gas turbine combustion device of this kind that can quickly discharge the flame out of the premixer and sufficiently prevent damage to the combustor. it can.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of a gas turbine combustion device of the present invention and an enlarged view of a main part thereof.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a longitudinal sectional side view showing another embodiment of the gas turbine combustion device of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is an axial sectional view of a premixer according to another embodiment of the present invention.

FIG. 6 is an axial sectional view of a premixer according to another embodiment of the present invention.

FIG. 7 is an axial sectional view of a premixer according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Combustor, 2 ... Combustion chamber, 3 ... Diffusion fuel nozzle, 4 ... Premixer, 5 ... Premixed fuel nozzle, 6 ... Swirler, 7 ... Diffusion burner, 8 ... Premixed burner, 9 ... Flame holder , 10, 11 ...
Fuel, 12 ... air, 20 ... air flow path (gas flow path), 21
... fuel injection holes, 30, 31 ... throttle structure (gas flow path narrowing means), 40 ... protrusions (air flow direction changing means), 50 ...
Premixer inlet.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Bunji Moriwaki 3-1-1, Sachimachi, Hitachi-City, Ibaraki Prefecture Inside the Hitachi Works, Hitachi, Ltd. No. 1-1 Inside Hitachi, Ltd.Hitachi Plant (72) Inventor Isao Takehara 3-1-1 Sakaicho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd.Hitachi Plant (72) Inventor Tetsuo Sasada Hitachi City, Ibaraki Prefecture 3-1-1 Sachimachi, Hitachi, Ltd.Hitachi Works, Hitachi, Ltd. (72) Inventor Kazuyuki Ito 7-2-1, Omika-cho, Hitachi, Ibaraki Pref. Inventor Nariki Kobayashi 7-2-1, Omika-cho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Power and Electricity Development Division

Claims (7)

[Claims] 1. A premixer for mixing air and fuel on an upstream side of a combustion chamber, wherein the premixer is disposed in a gas flow path through which combustion air and a mixed gas flow, and in the gas flow path. A fuel nozzle, wherein the fuel injected from the fuel nozzle is mixed with air in the premixer and is supplied to the combustion chamber. Upstream from the fuel injection port, and on the gas flow path wall surface of the premixer, air flow direction changing means for changing the flow of air flowing through the premixer in the direction of the fuel injection port of the fuel nozzle. A gas turbine combustion device, wherein a gas flow path restricting means for reducing a cross-sectional area of the gas flow path is provided downstream of a fuel injection port of the fuel nozzle. 2. A diffusion combustion fuel nozzle for performing diffusion combustion or a diffusion / premix combustion fuel nozzle capable of performing both diffusion combustion and premix combustion is disposed at the upstream central portion of the combustion chamber. A plurality of premixers for mixing air and fuel are arranged around the fuel nozzle for diffusion combustion or the fuel nozzle for combined diffusion / premixed combustion, and each of the premixers is a gas through which the combustion air and the mixed gas flow. A flow path, and a premix fuel nozzle disposed in the gas flow path, wherein fuel injected from the premix fuel nozzle is mixed with air in the premixer and supplied to the combustion chamber. In the gas turbine combustion device formed as described above, the fuel nozzle for diffusion combustion of the premixer or the inner wall of the gas passage on the side of the fuel nozzle for combined diffusion / premixed combustion and the premixed fuel nozzle On the inner wall surface upstream of the fuel injection port, air flow direction changing means for changing the flow of air flowing through the gas flow path in the direction of the fuel injection port of the premixed fuel nozzle is provided, and A gas turbine combustion device comprising a gas flow path narrowing means provided on a downstream side of a fuel injection port to reduce a cross-sectional area of the gas flow path. 3. The gas turbine combustion according to claim 1, wherein said air flow direction changing means is formed by a protrusion projecting into a flow passage on a part of an air flow path wall surface of said premixer. apparatus. 4. The gas turbine combustion apparatus according to claim 3, wherein the projection is formed so as to form a streamline in a flow direction of the air, and is formed integrally with a wall of the gas passage. 5. The gas flow path restricting means is formed by a full-circumferential projection so as to restrict the entire circumference of the air flow path wall surface of the premixer. Or the gas turbine combustion device according to 4. 6. A circumferential projection that narrows a cross-sectional area of the flow path of the premixer is formed so as to form a streamline in a flow direction of air, and is formed integrally with a wall surface of the gas flow path. The gas turbine combustion device according to claim 5, wherein 7. The projections of the circumferential projection for narrowing the cross-sectional area of the flow path of the premixer and the projection for changing the flow direction of the air are formed to have substantially the same height, and both of the projections are formed of air. The gas turbine combustion device according to claim 5, wherein the gas turbine combustion device is formed so as to be continuous in the flow direction of the gas turbine.