JP2005283001A - Combustion device for gas turbine engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of efficiently reducing discharge of air polluting material, while excellently absorbing axial extension of a combustion cylinder 30 due to thermal expansion with simple structure, in regard to a combustion device 100 for a gas turbine engine structured by arranging a combustor 10 for burning fuel G supplied through a fuel supply pipe 50 provided inside a combustor casing 1 by using air A inside the combustor casing 1 in a cylindrical combustor case 1 for driving a turbine 5 by supplying the compressed air A from an air opening 2 formed in one end thereof and by injecting combustion gas CG from an injection opening 3 formed in the other end thereof, and by forming the combustor 10 by arranging a pre-mixer 20 for forming pre-fuel-air-mixture by mixing the fuel G and the air A and the combustion cylinder 30 for burning the pre-air-fuel-mixture M formed by the pre-mixer 20 by receiving it in order from an upstream side. <P>SOLUTION: In this combustion device for a gas turbine engine, at least one part of a fuel supply pipe 50 is structured of a flexible tube 51. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, compressed air is supplied from an air port formed on one end side, and combustion gas is injected from a jet port formed on the other end side into a cylindrical combustor casing that drives a turbine. A combustor for combusting fuel supplied through a fuel supply pipe installed in the combustor casing using the air in the combustor casing, and the combustor mixes fuel and air. The present invention relates to a combustion apparatus for a gas turbine engine comprising a premixer that forms a premixed gas and a combustion cylinder that receives and burns the premixed gas formed by the premixer in order from the upstream side. .

  Examples of air pollutants discharged from a gas turbine engine that burns fossil fuels include nitrogen oxides, carbon monoxide, and unburned hydrocarbons. In recent years, regulations regarding the emission of these air pollutants tend to be stricter worldwide, and reduction of air pollutants discharged from gas turbine engines is strongly desired.

  As a technique for reducing the emission of air pollutants such as nitrogen oxides from gas turbine engines, a method of directly injecting a large amount of water or steam into a combustion section in a combustion apparatus for gas turbine engines or a gas turbine engine There is a method of reducing the combustion gas introduced into the selective reduction catalyst system, but the method of injecting a large amount of water or steam directly into the combustion section has problems such as an increase in operating cost and a reduction in fuel consumption. In the method using the selective reduction catalyst system, there are problems such as high equipment costs.

  The technology that is currently widely used in gas turbine engines as the most effective method is called lean premixed combustion technology, which premixes fuel and air to form a uniformly lean premixed fuel. Then, by burning this premixed gas, the flame temperature is lowered, and the high temperature region of the combustion part, which is the main factor for the generation of nitrogen oxides, is eliminated.

  As described above, the use of the gas turbine engine combustion apparatus that burns the lean premixed gas greatly contributes to the reduction of the amount of air pollutants discharged from the gas turbine engine. However, in such a combustion apparatus for a gas turbine engine, in order to effectively reduce the emission amount of air pollutants, it is necessary to form a premixed gas in which the fuel is uniformly lean. The combustion apparatus for the construction was configured as follows.

  As shown in FIG. 4, a conventional combustion apparatus for a gas turbine engine 200 is supplied with compressed air A from an air compressor 4 from an air port 2 formed on one end side, and a jet port formed on the other end side. The fuel G supplied from the fuel supply pipe 60 installed in the combustor casing 1 is injected into the cylindrical combustor casing 1 that ejects the combustion gas CG from the fuel injector 3 and drives the turbine 5. A combustor 10 that burns using the air A therein, and the combustor 10 includes a premixer 20 that mixes fuel G and air A to form a premixed gas M, and a premixer 20. Combustion cylinders 30 that receive and burn the formed premixed gas M are arranged in order from the upstream side, the combustion cylinders 30 are fixed to the combustor casing 1, and the premixer 20 is a combustion cylinder. 30 (for example, patent literature) See.).

  In such a gas turbine engine combustion chamber 200, the fuel supply pipe 60 is made of a hard metal material, and the fuel supply pipe 60 is temporarily fixed to the combustor casing 1 by the fixing mechanism 61 and the other end side. Is connected to the fuel distribution member 21 of the premixer 20. Further, in order to prevent the axial load on the premixer 20 by absorbing the elongation in the axial direction (the flow direction of air and combustion gas in the combustor casing) due to the thermal expansion of the combustion cylinder 30, The mixer 20 and the combustor 30 are separated from each other by inserting the outer cylinder 23 of the premixer 20 into the insertion portion 31 of the combustor 30.

JP 2001-324137 A

  In the conventional gas turbine engine combustion apparatus 200 as shown in FIG. 4, in order to absorb the axial extension due to the thermal expansion of the combustion cylinder 30, the outer cylinder 23 of the premixer 20 and the insertion portion 31 of the combustion cylinder 30. Therefore, a relatively low gap 7 is required, so that the relatively low temperature air A flowing outside the premixer 20 flows into the combustion cylinder 30 through the gap 7. And in the combustion cylinder 30, when the low temperature air A flows in from the clearance 7, the equivalence ratio or the temperature of the premixed gas M near the clearance 7 decreases, and the air pollutant is effectively removed. There was a problem that emissions could not be reduced.

  Furthermore, in the conventional combustion apparatus 200 for a gas turbine engine, since the fuel supply pipe 60 is connected to the fuel distribution member 21 of the premixer 20, complicated work is required for assembling the fuel supply pipe 60 and the premixer 20. It was necessary.

  In addition, in order to eliminate the gap between the premixer and the combustion cylinder as described above, the premixer and the combustion cylinder are fixedly connected with the gap eliminated, and the fuel supply pipe is integrated with the premixer. It is conceivable to insert the premixer into the premixer, but in this case, a gap is generated between the fuel supply pipe and the premixer, and fuel leaks from the gap. There is a problem that the discharge of air pollutants cannot be effectively reduced.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a gas turbine engine combustion apparatus with a simple configuration while satisfactorily absorbing axial expansion due to thermal expansion of a combustion cylinder or the like. The object is to provide a technology that can efficiently reduce the emission of air pollutants.

  In order to achieve the above object, a combustion apparatus for a gas turbine engine according to the present invention is configured such that compressed air is supplied from an air port formed on one end side, and combustion gas is ejected from a jet port formed on the other end side. A combustor that burns fuel supplied through a fuel supply pipe installed in the combustor casing using air in the combustor casing is disposed in a cylindrical combustor casing that drives a turbine. A premixer that mixes fuel and air to form a premixed gas, and a combustion cylinder that receives and burns the premixed gas formed by the premixer from the upstream side. A combustion apparatus for a gas turbine engine that is arranged and configured in order, and a first characteristic configuration thereof is that at least a part of the fuel supply pipe is constituted by a flexible pipe.

  According to the first characteristic configuration, at least a part of the fuel supply pipe is formed of a flexible pipe, so that the premixer to which the fuel supply pipe is connected, and the combustion cylinder connected to the premixer, Since the flexible tube can absorb the axial extension due to thermal expansion of the fuel, the fuel supply tube and the premixer and the premixer and the combustion cylinder are fixedly connected without any gaps. This effectively prevents the leakage of fuel in the gap between the fuel supply pipe and the premixer, and the inflow of air in the gap between the premixer and the combustion cylinder, effectively suppressing the emission of air pollutants. can do.

  A second characteristic configuration of the combustion apparatus for a gas turbine engine according to the present invention lies in that a guide member fixed to the combustor casing and surrounding at least the upstream side of the flexible tube is provided.

  According to the second characteristic configuration, by providing the guide member so as to surround the upstream side of the flexible tube, it is possible to prevent the air flow flowing through the combustor casing from directly colliding with the flexible tube. In addition, the flexible tube can be prevented from being deformed or vibrated by the air flow, and the fuel can be stably supplied by the fuel supply tube at least partially configured as the flexible tube.

In a third characteristic configuration of the combustion apparatus for a gas turbine engine according to the present invention, the guide member is formed in a tubular shape surrounding the entire circumference of the fuel supply pipe,
The premixer is formed with a support portion that is axially fitted to the guide member.

  According to the third characteristic configuration, the premixer is fitted to the tubular guide member so that the axial extension due to the thermal expansion between the premixer and the guide member is absorbed. The relative position of the premixer and the guide member in the transverse direction (the direction perpendicular to the flow of air and combustion gas in the combustor casing) is improved while preventing an axial load from being applied to the guide member and the guide member. For example, when the horizontal direction is the axial direction, the premixer in which the support portion is fitted to the guide member can be supported in the transverse direction by the guide member fixed to the combustor casing. it can.

  A fourth characteristic configuration of the combustion apparatus for a gas turbine according to the present invention is that a projection is formed on the outer surface of the guide member.

  According to the fourth characteristic configuration, the protrusion is formed on the outer surface of the guide member by, for example, winding a tripping wire to stabilize air separation, so that it passes through the outer surface of the guide member to the premixer. The fluttering of the supplied air can be prevented.

An embodiment of a gas turbine combustion apparatus (hereinafter abbreviated as a combustion apparatus) according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the combustion apparatus 100 is supplied with compressed air A from an air compressor 4 from an air port 2 formed on one end side, and generates combustion gas CG from an outlet 3 formed on the other end side. The fuel G supplied through the fuel supply pipe 50 installed in the combustor casing 1 in the cylindrical combustor casing 1 that jets and drives the turbine 5 is used in the air A in the combustor casing 1. The combustor 10 to be combusted is disposed, and the combustor 10 mixes the fuel G and the air A to form the premixed gas M, and the premixed gas formed by the premixer 20. Combustion cylinders 30 that receive M and burn it are arranged in order from the upstream side.

  Further, the combustion cylinder 30 is fixed to the combustor casing 1, and the premixer 20 is fixedly connected to the combustion cylinder 30 with no gap. Therefore, the relatively low temperature air A flowing outside the premixer 20 is prevented from flowing into the combustion cylinder 30 through the gap between the premixer 20 and the combustion cylinder 30, and air pollutants are discharged. It is effectively reduced.

The fuel supply pipe 50 is connected to a connection mechanism 62 attached to the combustor casing 1 and supplied with fuel G, and a connection portion 53 connected to the fuel distribution member 21 of the premixer 20. And a flexible tube 51 made of metal provided at both ends.
Then, by configuring a part of the fuel supply pipe 50 with the flexible pipe 51, the premixer 20 and its premixing are accompanied by a temperature change in the combustor casing 1 due to operation and stop of the combustion apparatus 100, for example. Even if the axial expansion amount due to thermal expansion of the combustion cylinder 30 to which the combustor 20 is fixed changes, the flexible pipe 51 bends to cause stress in the fuel supply pipe 50 and the premixer 20 in the axial direction. Is prevented from being damaged by the load.

In the combustor casing 1, a tubular guide tube 57 that surrounds the entire circumference of the fuel supply tube 50 is provided as a guide member that surrounds at least the upstream side of the flexible tube 51.
That is, in the combustor casing 1, for example, air A at about 500 ° C. flows at a flow rate of about 200 m / s. However, by providing the guide tube 57, the flow of the air A directly collides with the flexible tube 51. Thus, deformation and vibration of the flexible tube 51 are suppressed, and fluctuations in the amount of fuel G supplied to the premixer 20 are suppressed.

  The guide tube 57 is temporarily fixed to the connection mechanism 62 side of the combustor casing 1, but the other end is the downstream end of the fuel distribution member 21 of the premixer 20 as shown in FIG. 2. Since the support portion 24 protruding from the portion is fitted in a loosely fitted state in the axial direction, the premixer 20 is absorbed while the axial extension due to thermal expansion between the premixer 20 and the guide tube 57 is absorbed. And the relative position in the transverse direction of the guide tube 57 are fixed well. The outer diameter of the support portion 24 is preferably smaller than the inner diameter of the guide tube 57 by 2 mm or more.

  Further, when the axial direction of the combustion apparatus 100 is set to the horizontal direction, the support portion 24 of the premixer 20 is fitted into the guide tube 57 fixed to the combustor casing 1 as described above, so that the premixer A part of the weight of 20 can be supported by the guide tube 57, and the stress applied to the combustion cylinder 30 by the weight of the premixer 20 can be reduced.

  As shown in FIG. 2, a protrusion 56 is formed on the outer surface of the guide tube 57 by winding a tripping wire. By the protrusion 56, the air A flowing along the outer surface of the guide tube 57 is formed. Separation can be stabilized, and the flow of air A to the premixer 20 can be stabilized. Moreover, it is preferable that the height of such a protrusion 56 is 1 mm or more and 15 mm or less.

  Instead of the guide pipe 57, for example, a guide member that surrounds only the upstream side of the flexible pipe 51 of the fuel supply pipe 50 may be provided. Moreover, when the deformation | transformation and vibration of the flexible tube 51 by the flow of the air A do not become a problem, you may abbreviate | omit the said guide member.

In a gas turbine engine, when a plurality of combustion devices 100 as described above are arranged in a so-called cannula type with the turbine 5 axis as the center, fuel supply paths of the plurality of combustion devices 100 from one fuel supply source. When the fuel G is supplied to 50, the flow resistances in the flow paths to the respective fuel supply paths 50 are different from each other, the supply amounts of the fuel G in the respective combustion devices 100 are different, and the combustion state varies. May occur.
Therefore, as shown in FIG. 3, each fuel supply pipe 50 is provided with an orifice 54 capable of setting the flow rate of the fuel G by reducing the cross-sectional area of the flow path, and the opening area of each orifice 54 is set in accordance with each combustion. It is preferable to set the supply amount of the fuel G in the apparatus 100 to be equal.

The premixer 20 will be described. The premixer 20 includes an outer cylinder 23 fixed to the combustion cylinder 30, an inner cylinder 22 surrounded by the outer cylinder 23, and an outer periphery of the inner cylinder 22. It is comprised with the fuel distribution member 21 made.
Although the fuel distribution member 21 will not be described in detail, the fuel G is supplied to the air A flowing through the pilot combustion flow path 26 formed in the inner cylinder 22 so as to have a relatively high equivalent ratio. The fuel G is supplied to the air A flowing through the main combustion flow path 25 formed between the inner cylinder 22 and the outer cylinder 23 while forming the premixed gas Mp for pilot combustion, and a relatively low equivalent ratio The premixed gas Mm for main combustion is formed.
The pilot combustion premixed gas Mp formed in this way flows into the combustion cylinder 30 and relatively stable pilot combustion is performed, while the main combustion premixed gas enters the combustion cylinder 30. The main combustion is performed by the lean premixed gas Mm having a relatively low equivalent ratio in the form of flowing out and holding the flame by the pilot combustion.

  The premixed gas M is ignited by a spark plug 32 that is disposed in a state where the outer cylinder 23 and the inner cylinder 22 are formed from the combustor casing 1.

Schematic configuration diagram of a combustion apparatus for a gas turbine engine Partial enlarged view of fuel supply pipe Partial enlarged view of the guide tube Schematic configuration diagram of a conventional combustion apparatus for a gas turbine engine

Explanation of symbols

1: Combustor casing 3: Jet port 5: Turbine 10: Combustor 20: Premixer 22: Inner cylinder 23: Outer cylinder 24: Support section 30: Combustion cylinder 50: Fuel supply pipe 51: Flexible pipe 54: Orifice 57: Guide tube 100: Gas turbine combustion device A: Air CG: Combustion gas G: Fuel M, Mm, Mp: Premixed gas

Claims (4)

Compressed air is supplied from an air port formed on one end side, and a combustion gas is ejected from an outlet formed on the other end side into a cylindrical combustor casing that drives a turbine. A combustor is provided for combusting fuel supplied through a built-in fuel supply pipe using air in the combustor casing, and the combustor mixes fuel and air to produce a premixed gas. A combustion apparatus for a gas turbine engine configured to sequentially form a premixer to be formed and a combustion cylinder that receives and burns the premixed gas formed by the premixer, from the upstream side;
A combustion apparatus for a gas turbine engine, wherein at least a part of the fuel supply pipe is constituted by a flexible pipe.   The combustion apparatus for a gas turbine engine according to claim 1, further comprising a guide member fixed to the combustor casing and surrounding at least the upstream side of the flexible tube. The guide member is formed in a tubular shape surrounding the entire circumference of the fuel supply pipe;
The combustion apparatus for a gas turbine engine according to claim 2, wherein a support portion that is axially fitted to the guide member is formed in the premixer.   The combustion apparatus for a gas turbine engine according to claim 3, wherein a protrusion is formed on an outer surface of the guide member.

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