JP5807899B2 - Gas turbine combustor - Google Patents

Description

  The present invention relates to a gas turbine combustor, and in particular, a special structure is provided in an opening where a premixing tube and a combustion cylinder communicate with each other, so that it is held in the combustion cylinder corresponding to the magnitude of radiant heat of the fuel used. The present invention relates to a structure of a gas turbine combustor that makes it possible to easily set and change the position of a flame and prevents deterioration of the durability of a combustion cylinder due to the heat of the flame.

  Patent Document 1 below discloses an invention of a gas turbine combustor 1 including a combustion cylinder 2, a premixing pipe 3, and a fuel supply means 5. According to the gas turbine combustor 1, in the fuel supply means, the fuel is supplied to the annular fuel passage 16 along the tangential direction, is uniformly injected from the annular nozzle portion 19, and the circumferential air surrounding the nozzle portion Atomized by air from passage 22 creates an axial flow in the combustor. On the other hand, the air that has flowed into the premixed tube from the hole 25 on the peripheral wall surface creates a swirling flow that surrounds the axial flow in the combustor. As a result, the flame is held at a position away from the top of the combustor, and the heat shield plate 6 is not overheated and the durability is improved.

  Further, in Patent Documents 2 and 3 below, in a burner that burns fuel, fuel and air are sufficiently mixed by a straight flow air that goes to the combustion cylinder and a swirl flow air by a swirler to stabilize combustion and reduce low emission. An invention relating to a gas turbine combustor that attempts to achieve the above is described.

JP 2009-198054 A US Pat. No. 5,735,681 US Pat. No. 5,879,148

  However, in the conventional gas turbine combustor as described above, when the air-fuel mixture supplied from the premixing tube burns as a flame in the combustion cylinder, the preheat is prevented so that the radiant heat of the flame does not damage the combustion cylinder. It is common to hold the flame at a position that is a predetermined distance away from the top of the combustion cylinder with which the mixing tube communicates. The distance from the top of the combustion cylinder to the flame is called the lift distance.

  By the way, the radiant heat of the flame varies depending on the type of fuel. Therefore, when designing a conventional gas turbine combustor, the flame lift distance should be set to an appropriate length that will not cause thermal damage to the device. Therefore, the structure of the apparatus has been set so that the amount of swirling air from the premixing tube and the amount of straight-running air are appropriately balanced.

  Specifically, the balance between the swirling air amount and the straight air amount was set to a desired value by adjusting the swirl number of the swirler used and the shape structure of the premixing tube. The operation of adjusting the structure and the like of each part according to the distance is complicated and complicated and requires a lot of time and cost.

  Furthermore, even in a gas turbine combustor in which a lift distance is set in accordance with a predetermined type of fuel, another fuel having different radiant heat during combustion may have to be used depending on the convenience of use. In such a case, in order to set different lift distances corresponding to the change of fuel, the structure of each part of the gas turbine combustor is changed, and the swirling air amount and the straight air amount from the premixing pipe are adjusted. It was necessary to do. Specifically, when the lift distance is shortened, modification is required to increase the amount of swirling air and decrease the amount of straight air travel. When increasing the lift distance, the amount of swirling air is decreased. It is necessary to make modifications to increase the amount of straight air. Such remodeling work is more complicated and complicated than when a new gas turbine combustor is manufactured, and much more time and cost are required.

  Therefore, the present invention solves the above-described problems, and can easily set and change the lift position of the flame held in the combustion cylinder in order to cope with the magnitude of the radiant heat of the fuel used. The purpose is to do so.

A gas turbine combustor according to claim 1 is provided.
A combustion cylinder that burns a mixture of fuel and air to supply combustion gas to the turbine;
A premixing pipe that is provided in the combustion cylinder so as to be provided and supplied to the combustion cylinder by mixing the supplied fuel and air;
Fuel supply means provided in the premixing tube and supplying fuel to the premixing tube;
An inner diameter enlarged portion provided at the opening end where the premixing tube opens in the combustion cylinder, in an exchangeable manner with an inner diameter enlarged portion of another inner diameter enlarged shape ,
It is characterized by having.

  The gas turbine combustor described in claim 2 is characterized in that, in the gas turbine combustor described in claim 1, the inner diameter enlarged portion has a plane machining portion having a predetermined angle.

  A gas turbine combustor according to a second aspect is the gas turbine combustor according to the first aspect, wherein the inner diameter enlarged portion has a curved surface processing portion.

  According to the gas turbine combustor according to the present invention, the opening end of the premixing tube with respect to the combustion cylinder is provided with the inner diameter enlarged portion, and the lift distance of the flame in the combustion cylinder according to the shape of the inner diameter enlarged portion. Is determined. That is, since the inner diameter expanding portion has a shape in which the inner diameter expands along the axial direction from the premixing tube toward the combustion cylinder, the swirling flow of air flowing along the inner peripheral surface of the premixing tube By flowing along the inner diameter enlarged portion at the opening, the gas flows into the combustion cylinder while expanding outward.

  Therefore, as the degree of inner diameter expansion in the inner diameter enlarged portion is relatively large and the shape is such that it escapes to the outside, the swirling flow of air is guided to the outside in the combustion cylinder. The cross-sectional area of the straight flow of the traveling air is relatively large. As a result, assuming that the amounts of fuel and air are constant, the speed of the air-fuel mixture becomes relatively small, so that the flame is held at a position closer to the premixing tube, and the lift distance becomes relatively short.

  On the contrary, the degree of the inner diameter expansion in the inner diameter enlarged portion is relatively small and the degree of escape to the outside is relatively small, so that the degree of air swirling flow is relatively guided outside in the combustion cylinder. Therefore, the cross-sectional area of the straight flow of the air flowing through the center of the premixing tube is relatively small. As a result, if the amount of fuel and air is assumed to be constant, the speed of the air-fuel mixture becomes relatively large, so that the flame is held at a far position by the premixing tube, and the lift distance becomes relatively long.

  Therefore, when using a fuel that has a relatively large radiant heat when burned, an inner diameter enlarged portion having a relatively smaller inner diameter is employed to make the flame lift distance relatively long and the radiant heat relatively When using a small fuel, it is only necessary to adopt an inner diameter enlarged portion having a relatively larger inner diameter to shorten the flame lift distance. In this way, the lift amount of the flame can be arbitrarily set according to the radiant heat of the fuel to be used, by simply replacing the enlarged inner diameter portion without changing the structure of the swirling air amount or the straight air amount. Therefore, the deterioration of the durability of the combustion cylinder due to the heat of the flame can be reliably prevented regardless of the type of fuel.

It is a longitudinal section of a gas turbine combustor concerning one embodiment of the present invention. It is an expanded longitudinal cross-sectional view of the premixing pipe vicinity in one Embodiment. (A) is an enlarged vertical sectional view schematically showing a structure near the opening of the premixing tube of the embodiment (when the chamfer of the inner diameter enlarged portion is C8) and a relatively short flame lift distance L1 at the time of combustion. It is a figure, (b) is a figure which shows the photograph of the flame. (A) schematically shows a structure in the vicinity of the opening of the premixing tube of the embodiment (when the chamfer of the inner diameter enlarged portion is C3) and a flame lift distance L2 that is a relatively median value at the time of combustion. It is an expanded longitudinal cross-sectional view, (b) is a figure which shows the photograph of the flame. (A) is an enlarged vertical sectional view schematically showing a structure in the vicinity of the opening of the premixing tube of the embodiment (when the chamfer of the inner diameter enlarged portion is C0) and a relatively long flame lift distance L3 at the time of combustion. It is a figure, (b) is a figure which shows the photograph of the flame. It is a figure which shows the graph showing the velocity distribution of the air and unignited fuel gas on the centerline of a premixing pipe. It is a figure which shows the graph showing the velocity distribution of the combustion gas on the centerline of a premixing pipe. It is an expanded longitudinal cross-sectional view which shows the structure of the opening vicinity of the premixing tube of 2nd Embodiment, (a) is a curved surface process of an internal diameter expansion part is R30, (b) is a curved surface process of an internal diameter expansion part is R20. In the case, (c) is a diagram showing a case where the curved surface processing of the inner diameter enlarged portion is R10.

The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.
First, the overall configuration of the gas turbine combustor 1 according to the first embodiment will be described with reference to FIG.
The gas turbine combustor 1 has a combustion cylinder 2 having a substantially cylindrical shape. The top of the combustion cylinder 2 is closed, and a lower opening communicates with an exhaust side of a gas turbine (not shown). Although details will be described later, a premixing tube 3 is attached to the top of the combustion cylinder 2, and a pressure injection device 4 as fuel supply means is attached to the top of the premixing tube 3. The combustion cylinder 2 and the premixing pipe 3 are surrounded by an outer cylinder 5 that communicates with a compressed air intake port of a turbo compressor (not shown), and a part of the fuel supply system connected to the pressure injection device 4 is The outer cylinder 5 is guided to the outside through the top.

  As shown in FIGS. 1 and 2, a premixing tube 3 is coaxially arranged at the center of the top of the combustion cylinder 2. The premixing tube 3 is disposed so as to protrude by a predetermined size into the lower combustion cylinder 2 attached to the top of the combustion cylinder 2 and a cylindrical peripheral wall 6 attached to the outside of the top of the combustion cylinder 2. It is composed of a cylindrical projecting wall 7. The outer shape of the peripheral wall 6 is a right cylindrical shape, but the inner shape thereof has a shape in which the inner diameter gradually decreases toward the lower combustion cylinder 2. The peripheral wall 6 is formed with a plurality of holes 8 through which air flows in along the tangential direction. The protruding wall 7 is a right cylindrical body having an inner diameter equal to the opening at the lower end of the peripheral wall 6, and is connected to the lower end of the peripheral wall 6.

  As shown in FIGS. 2 and 3, an inner diameter enlarged portion 10 is attached to the opening end of the protruding wall 7 of the premixing tube 3 that opens in the combustion cylinder 2. The inner diameter enlarged portion 10 is an annular member, and a chamfered portion 11 is formed on the inner peripheral edge of the inner peripheral portion, which is a planar processing portion that is inclined downward at a predetermined angle. In this embodiment, the angle of the chamfered portion is 45 degrees, the horizontal and vertical dimensions are 8 mm, and the chamfering process represented by C8 is applied to the inner peripheral edge as shown by the JIS symbol. I can say that.

  As shown in FIG. 2, a cylindrical inner wall 9 is coaxially arranged at a predetermined interval inside the peripheral wall 6 of the premixing tube 3. The outer peripheral surface of the inner wall 9 has a shape in which the outer diameter gradually decreases toward the lower combustion cylinder 2, and the radial interval between the peripheral wall 6 and the inner wall 9 is constant and A cylindrical gap S that narrows toward the end is formed. The gap S has an upper end that is one end side of the premixing tube 3 closed, and a lower end opened near the upper end of the protruding wall 7. Further, the inner peripheral surface of the inner wall 9 has a right cylindrical shape, and the upper end of the inner wall 9 that is one end side of the premixing tube 3 opens into the outer cylinder 5.

  Therefore, the compressed air from the turbo compressor guided into the outer cylinder 5 flows into the inside through the hole 8 of the peripheral wall 6 of the premixing tube 3 and is formed in the cylindrical gap S between the peripheral wall 6 and the inner wall 9. It turns into a swirl flow, further proceeds to the opening end while swirling along the inner peripheral surface of the projecting wall 7, and sent to the combustion cylinder 2 through the inner diameter enlarged portion 10.

  In addition, the compressed air is supplied to the inside of the inner wall 9 from the opening at the upper end of the inner wall 9 together with the fuel supplied from the pressure injection device 4 to become an air-fuel mixture, and the inner side of the inner wall 9 without being affected by the swirling flow. In the entire region, the straight flow is uniform along the axial direction of the inner wall 9 and is fed into the combustion cylinder 2.

  Here, the inner diameter expanding portion 10 has a shape in which the chamfered portion 11 faces obliquely downward, and the inner diameter increases as it advances toward the combustion cylinder 2 along the central axis. The flow flows along the chamfered portion 11 of the inner diameter enlarged portion 10 at the opening end of the projecting wall 7 of the premixing tube 3 and flows into the combustion cylinder 2 while expanding outward.

  Therefore, the swirling flow of air has an effect of being guided outside in the combustion cylinder 2 in accordance with the degree of expansion of the inner diameter of the inner diameter expanding portion 10. The area is affected as follows depending on the degree to which the swirl flow is directed outward.

  That is, if the degree to which the swirling flow of air is guided outward by the inner diameter enlarged portion 10 increases, the cross-sectional area of the straight air flow increases, and the amount of fuel and air is considered to be constant. Is relatively small. Therefore, the flame has a shorter lift distance and becomes closer to the top of the combustion cylinder 2. Further, if the degree to which the swirling flow of air is guided outward by the inner diameter enlarged portion 10 is reduced, the cross-sectional area of the straight air flow is reduced, and if the amount of fuel and air is considered constant, the speed of the air-fuel mixture Is relatively large. Accordingly, the flame becomes longer from the top of the combustion cylinder 2 as the lift distance becomes longer. Thus, the lift distance of the flame is determined according to the extent of the inner diameter expansion of the chamfered portion 11 in the inner diameter expanded portion 10 (in this case, the size of the chamfering process).

  As shown in FIG. 2, the pressure injection device 4 is arranged at the center of the opening at the upper end of the peripheral wall 6 that is one end side of the premixing tube 3. The pressure injection device 4 is a hollow cone type pressure injection nozzle that highly atomizes liquid fuel by injecting the fuel into a hollow conical shape. The pressure injection device 4 is configured such that fuel supplied from two fuel supply passages, that is, a main supply passage 20 and a pilot supply passage 21, flows out from the same injection nozzle 22, and a swirl motion is given to the fuel. As a result, the fuel discharged from the injection nozzle 22 spreads due to the centrifugal force to form a hollow conical membrane. As such a hollow cone type pressure injection nozzle, what is called a simplex injection valve is known.

  The injection angle of the injection nozzle 22 of the pressure injection device 4 is set such that the fuel injected in a conical shape does not adhere to the inner diameter enlarged portion 10 provided at the opening end of the protruding wall 7 of the premixing tube 3. Has been. Further, around the injection nozzle 22, a flow path 25 that guides and injects the compressed air in the outer cylindrical body 5 from the introduction port 24 is provided. Therefore, since the spread of the fuel injected in a conical shape from the injection nozzle 22 is suppressed by the air from the flow path 25, the adhesion of the fuel to the protruding wall 7 or the inner diameter enlarged portion 10 can be further relaxed / suppressed. it can.

Next, the operation of the gas turbine combustor 1 of the present embodiment configured as described above will be described.
The compressed air from the turbo compressor is usually at a temperature of about 300 ° C., for example. This compressed air is guided into the outer cylindrical body 5 and flows into the inside through a hole 8 provided in the peripheral wall 6 of the premixing tube 3, and turns into a swirl flow in the cylindrical gap S between the peripheral wall 6 and the inner wall 9. . After this swirl flow exits from the gap S, it flows along the inner peripheral surface of the projecting wall 7, reaches the open end of the projecting wall 7, and further flows along the chamfered portion 11 of the inner diameter enlarged portion 10. It flows into the combustion cylinder while expanding.

  On the other hand, the compressed air is also supplied to the space inside the inner wall 9 from the opening at the upper end of the premixing tube 3, forms a mixture with the fuel injected from the pressure injection device 4, and proceeds straightly from the protruding wall 7. It is sent to the combustion cylinder 2 and combusted, for example, to generate combustion gas of 1000 to 2000 ° C. In addition, the temperature of air and gas in the above description is an example.

  In such a flow of air or the like in the present embodiment, the swirling flow is guided and expanded outward along the inner diameter enlarged portion 10, so that the flow cross-sectional area of the straight air flow at the center of the premixing tube 3 is The swirl flow is in accordance with a mode of expanding outward. In other words, if the amount of fuel and air is assumed to be constant, the swirl flow is largely guided outward, and the flow velocity of the air-fuel mixture becomes relatively smaller as the flow cross-sectional area of the straight air flow increases. Flame lift distance is reduced. In addition, since the swirl flow is not guided to the outside so much, when the cross-sectional area of the straight flow of the air does not expand, the speed of the air-fuel mixture becomes relatively large, and as a result, the flame lift distance becomes long. .

  The compressed air and the fuel or the mixture thereof inside the inner wall 9 are not interfered with the swirling flow of the compressed air formed by the gap S between the peripheral wall 6 and the inner wall 9, and the inner wall 9 in the entire area inside the inner wall 9. As described above, the flow cross-sectional area of the straight flow is adjusted in accordance with the outward expansion of the swirling flow in the inner diameter expanding portion 10 as described above. It burns with the lift distance according to the speed corresponding to the adjusted channel cross-sectional area.

  As described above, the straight flow of the air-fuel mixture in the premixing tube 3 is reduced in flow passage cross section due to the swirling flow of the air flowing from the hole 8 in the peripheral wall 6 of the premixing tube 3 and the flow velocity is excessively increased. However, after being fed into the protruding wall 7 at a stable and constant flow rate, the speed is adjusted according to the shape of the inner diameter enlarged portion 10 when passing through the inner diameter enlarged portion 10 or immediately after that, as shown in FIG. As shown to a), it becomes the flame F by the predetermined lift distance L1 in the combustion cylinder 2, and will be in the state hold | maintained stably as shown to the same figure (b). For this reason, the flame F is stably held at an appropriate position in the combustion cylinder 2, the deterioration of the durability of the combustion cylinder 2 due to heat is prevented, and stabilization of combustion and low emission are realized.

  FIG. 3 described above is a case where the chamfered portion 11 of the inner diameter enlarged portion 10 is C8. In this gas turbine combustor 1, in order to use a fuel having a larger radiant heat generated during combustion, the lift distance L is further increased. Suppose you want to take a long time. For example, the radiant heat generated by aromatic fuel is greater than the radiant heat generated when kerosene or light oil is burned, so even if the structure in FIG. If this fuel is used, the combustion cylinder 2 and the like may be damaged by heat. According to the present embodiment, the inner diameter enlarged portion 10 provided at the opening end of the premixing tube 2 is attached by a simple attachment means such as a bolt, so that the inner diameter enlarged portion 10 having a chamfered portion 11 having another dimensional structure. It is possible to easily cope with the fuel change by simply replacing the fuel cell. Therefore, in order to change / adjust the lift distance L of the flame, the shape and the like of the premixing tube 3 of the gas turbine combustor 1 are changed later so that the amount of swirling air from the premixing tube 3 and the amount of straight air flow are subtle. There is no need to perform complicated and difficult operations for making changes and adjustments.

  For example, as shown in FIG. 4A, the angle of the chamfered portion 11 is 45 degrees, its horizontal and vertical dimensions are 3 mm, and a process represented by C3 of the JIS symbol has been performed. It is assumed that the inner diameter enlarged portion 10 is used. Since the swirling flow is not expanded and guided outward as in the case of FIG. 3, the flow cross-sectional area of the straight flow of the air traveling in the center of the premixing tube 3 is narrower than that in the case of FIG. Assuming that the amount of air is constant, the speed becomes relatively large, and as a result, the lift distance L2 of the flame F becomes longer than L1 in the case of FIG. 3, and in the farther position in FIG. As shown, the flame is stably held.

  Further, as shown in FIG. 5 (a), it is assumed that the inner diameter enlarged portion 10 which has no chamfered portion 11, is perpendicular to the cross section, and is processed to be C0 if represented by a JIS symbol is used. In this case, the chamfering process is not actually performed, and the inner diameter is the same as the inner diameter of the protruding wall 7 of the premixing tube 3 regardless of the name of the inner diameter enlarged portion 10 and is not enlarged. The swirling flow is not expanded or guided outward as in the case of FIG. 4, but is supplied into the combustion cylinder 2 while descending along the inner peripheral surface of the protruding wall 7. For this reason, the straight flow of air traveling through the center of the premixing tube 3 does not cause a substantial change in the flow path cross-sectional area. Therefore, if the amount of fuel and air is considered to be constant, the speed does not change greatly, and becomes relatively large compared to the case of FIG. 4, and as a result, the lift distance L3 of the flame F is the same as that in FIG. It becomes longer than L2, and the flame is stably held at the farthest position as shown in FIG.

  As described above, whether or not the lift distance of the flame F is appropriate should be determined according to the degree of radiant heat of the flame F. If the lift distance is too short with respect to the temperature of the flame F, the combustion cylinder 2 and the like. If the lift distance is too long with respect to the temperature of the flame F, the combustion may become unstable and the flame F may disappear. Therefore, in this embodiment, as illustrated in FIGS. 3 to 5, by selecting and attaching the inner diameter enlarged portion 10 having an appropriate inner diameter enlarged shape in accordance with the degree of radiant heat of the flame F, an appropriate flame F can be obtained. This shows that the lift distance L can be easily obtained. Therefore, the angle, dimension, and the like of the chamfered portion 11 of the inner diameter enlarged portion 10 can be variously set in accordance with the required flame lift distance and the configuration of the entire apparatus.

Next, in the gas turbine combustor 1 of this embodiment, the results of actual measurement of the actual flow rates of air and fuel or combustion gas will be described.
FIG. 6 shows data in a non-combustion state in which air and fuel gas are flown without ignition in the gas turbine combustor of the present embodiment. The gas velocity distribution on the center line of the premixing tube 3 with the outlet of the premixing tube 3 as the origin (X = 0) is measured for each of the inner diameter enlarged portions 10 of C8, C3, and C0 shown in FIGS. It is shown as a graph. The unit of distance X on the horizontal axis is mm, and the unit of axial velocity U on the vertical axis is m / s. In this non-combustion state, the speed of the flow rate is small at the outlet of the premixing tube 3 (X = 0), but the difference occurs as the distance X becomes longer, and C0 (FIG. 5), C3 ( 4) and C8 (FIG. 3).
From this result, it can be seen that, as described above, the swirling flow escapes outward as the inner diameter expanding portion 10 having a larger inner diameter increases, so that the flow speed of the straight flow decreases because the cross-sectional area of the flow increases.

FIG. 7 is data of a combustion state in which the gas turbine combustor 1 according to this embodiment is ignited by flowing air and fuel gas. The velocity distribution of the combustion gas on the center line of the premixing tube 3 with the exit of the premixing tube 3 as the origin (X = 0) is shown for each inner diameter enlarged portion 10 of C8, C3, and C0 shown in FIGS. It is actually measured and shown as a graph. The units of the horizontal and vertical axes are the same as in FIG. In this combustion state, the flow velocity is not constant for each inner diameter enlarged portion 10 and decreases as the distance X increases from the outlet (X = 0) of the premixing tube 3, but starts to increase at a certain position, and then remains constant. Follow the change of rising to the value. The position X at which the speed changes from descending to ascending, that is, the X value corresponding to the minimum value in each graph is the lift distance L, which differs depending on the structure of the inner diameter enlarged portion 10 as described above, and is shown in FIG. According to FIG. 3, L = 31 in C8 (FIG. 3), L = 35 in C3 (FIG. 4), and L = 39 in C0 (FIG. 5) from the shortest. This is because the speed decreases in the order of C8, C3, C0 until the minimum value due to the structure of each inner diameter enlarged portion 10, and the lift distance L at which the flame is generated in the order of C8, C3, C0 is as follows. This is because it becomes shorter. In any case after the position where the flame is generated, the speed of the combustion gas increases to a certain value.
From this result, as described above, it can be understood that the larger the inner diameter enlarged portion 10 having the larger inner diameter, the shorter the flame lift distance, and the closer the flame approaches the lower end portion of the premixing tube 3 (or the top portion of the combustion cylinder 2).

Next, with reference to FIG. 8, the structural example of the internal diameter expansion part 20 in the gas turbine combustor of 2nd Embodiment is demonstrated.
As shown in FIG. 8, a circumferential surface portion 21 having a predetermined radius and a section having a central angle of 90 degrees is formed as a curved surface processing portion on the inner peripheral edge of the inner diameter enlarged portion 20 of the present embodiment. 8A shows the case where the radius is 30 mm, FIG. 8B shows the case where the radius is 20 mm, and FIG. 8C shows the case where the radius is 20 mm, both of which are at the open end of the protruding wall 7 of the premixing tube 3. It attaches so that the internal diameter as the internal diameter expansion part 20 may spread toward the combustion cylinder 2 below illustration so that it may continue with the internal peripheral surface of the protrusion wall 7. FIG. The attachment method is arbitrary, and although not particularly illustrated, a detachable bolt stop as in the first embodiment is preferable . Also according to this embodiment, the same effect as that of the first embodiment can be obtained. Further, as the curved surface processing portion, the peripheral surface portion 21 having a predetermined radius and a sectoral cross section as in the present embodiment may be used, but the radius is not constant, but a curved surface whose inner diameter widens toward the combustion cylinder 2 at the lower side of the figure. It may be provided.

DESCRIPTION OF SYMBOLS 1 ... Gas turbine combustor 2 ... Combustion cylinder 3 ... Premixing pipe 4 ... Pressure injection apparatus 7 ... Projection wall which comprises premixing pipe 10,20 ... Inner diameter enlarged part 11 ... Chamfering part as a chamfering part 21 ... Curved surface processing Peripheral surface as part F ... Flame L ... Flame lift distance

Claims (3)

A combustion cylinder that burns a mixture of fuel and air to supply combustion gas to the turbine;
A premixing pipe that is provided in the combustion cylinder so as to be provided and supplied to the combustion cylinder by mixing the supplied fuel and air;
Fuel supply means provided in the premixing tube and supplying fuel to the premixing tube;
An inner diameter enlarged portion provided at the opening end where the premixing tube opens in the combustion cylinder, in an exchangeable manner with an inner diameter enlarged portion of another inner diameter enlarged shape ,
A gas turbine combustor comprising: The gas turbine combustor according to claim 1, wherein the inner diameter enlarged portion includes a planar processing portion having a predetermined angle. The gas turbine combustor according to claim 1, wherein the inner diameter enlarged portion has a curved surface processing portion.