JPH11257660A - Combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability and durability without increasing the size of a device under a condition that the combustion, reduced in the producing of NOx, is satisfied by a method wherein fuel, used for combustion in a combustion cylinder, is guided and fluid, necessary for the combustion, is guided also while a part of combustion gas, produced in the combustion cylinder, is guided to join with the guided fluid. SOLUTION: This combustion device comprises a combustion cylinder or an inner cylinder 32, whose inside is a combustion chamber 31, an outer cylinder 33, arranged around the outside of the inner cylinder 32, and a fuel guide mechanism 36, including a fuel supplying pipe 35 for supplying the fuel 34 used for combustion in the inner cylinder 32. Further, the combustion device comprises an air flow guide mechanism 37, guiding fluid, necessary for combustion or air, into the inner cylinder 32 through a space between the inner cylinder 32 and the outer cylinder 33, and combustion gas extracting mechanisms 38a, 38b, joining a part of high-temperature combustion gas, produced in the inner cylinder 32, with the flow of air, passing between the inner cylinder 32 and the outer cylinder 33. In this case, the downstream side of the combustion chamber 31 or the opening end side of the inner cylinder is communicated with a gas turbine through a gas guiding passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a combustion device suitable for use in a gas turbine device or the like.

[0002]

2. Description of the Related Art As is well known, in a general gas turbine apparatus, as shown in FIG. 7, fuel 1 is heated together with high-temperature (about 300 to 600.degree. C.) air 2 compressed by a compressor (not shown). The combustion chamber 4 formed by the combustion cylinder 3 guides the combustion chamber 4 for combustion, the turbine 6 is rotated by the combustion gas 5 generated by the combustion, and the generator is directly connected to the turbine 6 to generate power. .

[0003] Recently, NO during combustion has been increasing.
To reduce the amount of x (nitrogen oxides) generated,
A so-called high-temperature air combustion system, in which fuel is burned using high-temperature air of about 00 ° C., has attracted attention. This high-temperature air combustion system is said to satisfy most of the practically desired characteristics such as low NOx, low noise, and flattening of the flame temperature.

Attempts have been made to apply such a high-temperature air combustion method to a combustion device in a gas turbine device. For example, in Japanese Patent Application No. Hei 8-261015,
A configuration as shown in FIG. 8 is proposed. That is,
In this gas turbine device, the compressed air 12 compressed by the compressor 11 is guided to the preheating chamber 13 to be preheated, and the preheated compressed air 12 and the fuel 14 are guided to the combustion chamber 15 for combustion. A gas turbine 17 is rotated by the generated combustion gas 16, and power is generated by a generator 18 directly connected to the gas turbine 17. here,
As a heat source of the preheating chamber 13, a radiant tube type high-speed switching type regenerative combustor having a regenerator 21 for rapidly changing the direction of the combustion gas flowing through the radiant tube 19 by a switch 20 and recovering heat from exhaust gas. The compressed air 12 is preheated to about 1000 ° C. by the heat of combustion of the combustor 22.

[0005] With this configuration, the fuel can be burned in the radiant tube type high-speed switching type regenerative combustor 22 and the combustion chamber 15 by the high-temperature air combustion system, so that the amount of NOx generated due to the combustion is suppressed. can do.

However, the conventional combustion apparatus employing such a high-temperature air combustion system has the following problems. In other words, a configuration in which the compressed air is preheated to about 1000 ° C and a part in which fuel is burned using the preheated air is adopted, so that the entire combustion device becomes larger and the gas turbine becomes larger. When combined with the above, there is a problem that the entire gas turbine device is enlarged. In addition, the radiant tube type fast switching type regenerative combustor,
Since it requires a regenerator and a switching mechanism that switches the flow direction of the combustion flow at high speed, reliability and durability are poor, and since the wall of the radiant tube becomes a heat exchange wall, 1000 ° C
It is necessary to form the radiant tube with a material that can sufficiently withstand the temperature of the order, and there is also a problem that the price of the entire apparatus is increased.

[0007]

As described above, the conventional combustion apparatus employing the high-temperature air combustion system not only leads to an increase in the size of the whole, but also has poor reliability and durability, and has a high performance. There was a problem of price. Therefore, an object of the present invention is to provide a combustion apparatus that can solve the above-described conventional problems in a state where the conditions for NOx reduction combustion are satisfied.

[0008]

In order to achieve the above object, in the combustion apparatus according to the first aspect, a combustion cylinder forming a combustion chamber and a fuel for guiding fuel supplied to the combustion chamber into the combustion cylinder are provided. Guiding means, fluid guiding means for guiding a fluid required for combustion into the combustion cylinder, and combustion gas for joining a part of the combustion gas generated in the combustion cylinder to the fluid guided by the fluid guiding means Extraction means.

In order to achieve the above object, in a combustion apparatus according to a second aspect, an inner cylinder forming a combustion chamber, an outer cylinder disposed outside the inner cylinder, and a combustion chamber provided in the inner cylinder. Fuel guide means for guiding the fuel to be supplied, fluid guide means for guiding a fluid necessary for combustion into the inner cylinder through a space between the inner cylinder and the outer cylinder, and a fluid guide means formed in the inner cylinder. A combustion gas extracting means for joining a part of the combustion gas to a fluid flowing between the inner cylinder and the outer cylinder.

[0010] In the combustion apparatus according to claim 2,
The combustion gas extracting means is provided between the inner cylinder and the outer cylinder to increase the flow rate of the fluid, and faces a speed increasing region at the peripheral wall of the inner cylinder by the speed increasing means. And the difference between a high pressure equal to almost the total pressure of the high-temperature combustion gas in the inner cylinder and a low static pressure of the speed-up flow. It is preferable that it is constituted by an extraction path that partially joins the speed-increasing fluid.

Further, in the combustion apparatus according to claim 2,
A flow path through which a cooling fluid flows may be provided in the peripheral wall of the inner cylinder. And the said flow path may be provided with the protrusion for improving a cooling characteristic on the inner surface.

When a part of the high-temperature combustion gas joins with the fluid required for combustion guided by the fluid guide means by the action of the combustion gas extraction means, heat is supplied from the high-temperature combustion gas to receive the fluid required for combustion. Is automatically preheated to a high temperature, and this high temperature fluid is sent into the combustion chamber as a combustion fluid.

As described above, a so-called self-preheating method is employed in which a combustion fluid, that is, combustion air is preheated to a high temperature by using a part of the high-temperature combustion gas generated by the combustion device itself. A high-temperature air combustion system, that is, NOx reduction combustion, can be realized in a state in which the size of the entire apparatus is reduced as compared with a system provided with a combustion unit for the main combustion.

In particular, the means for increasing the flow velocity of the fluid, that is, the air flow, guided by the fluid guiding means is combined with the extraction passage provided on the wall of the combustion chamber, and the ejector action or the inner cylinder in this combination is combined. With a structure in which a part of the high-temperature combustion gas is combined with the air flow by utilizing the difference between the high pressure substantially equal to the total pressure of the high-temperature combustion gas and the low static pressure of the accelerated flow, no moving part is required. Since the air flow can be preheated, stability and durability can be sufficiently satisfied.

Further, since the combustion air is not preheated through the heat exchange wall, for example, the components of the combustion cylinder can be sufficiently cooled. Therefore, a high-temperature air combustion system can be realized without using expensive heat-resistant materials, and an existing combustion device can be easily applied by only partially changing the structure.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a combustion device according to an embodiment of the present invention, here, a combustion device for a gas turbine device.

This combustion device is roughly divided into an inner cylinder 32 as a combustion cylinder having an interior as a combustion chamber 31, and an inner cylinder 3 as a combustion cylinder.
2, a fuel guide mechanism 36 including a fuel supply pipe 35 for supplying a fuel 34 to be burned into the inner cylinder 32, and a space between the inner cylinder 32 and the outer cylinder 33. An air flow guide mechanism 37 that guides a fluid required for combustion, that is, an air flow, into the inner cylinder 32 through the inner cylinder 32, and a part of the high-temperature combustion gas generated in the inner cylinder 32 is And a combustion gas extraction mechanism 38a, 38b that merges with the airflow flowing between them.

The inner cylinder 32 is formed in a so-called bottomed cylindrical shape in which one end is closed by a closing wall 39 and the other end is opened. The combustion chamber 31 has the closed wall 39 side upstream and the open side downstream. Note that the downstream side of the combustion chamber 31, that is, the open end side of the inner cylinder 32 communicates with the gas turbine via a gas guide path (not shown).

A communication hole (not shown) formed in the closing wall 39 extends from the open end side of the inner cylinder 32 into the closing wall 39 inside the peripheral wall and the closing wall 39 constituting the inner cylinder 32. A cooling flow path 40 is provided which communicates with the most upstream part of the combustion chamber 31 through the cooling medium. The inlet of the cooling passage 40, that is, the end 41 located on the open end side of the inner cylinder 32, communicates with the air compressor driven by the gas turbine.

As shown in FIG. 2, a plurality of projections 42 for increasing the cooling effect are provided on the inner surface of the cooling passage 40. As shown in FIG. 2, a plurality of holes 44 for feeding a part of the cooling air 43 to the combustion chamber 31, for example, into the middle flow area for dilution, are provided in the inner wall of the cooling passage 40 in the middle thereof. Is provided. The hole 44 for dilution is used.
Is provided not only in the middle area of the combustion chamber 31 but also in a required place. Further, as shown in FIG. 2, a plurality of ejection holes 45 for using a part of the cooling air 43 for film cooling are provided on the inner and outer constituent walls in the middle of the cooling passage 40. Have been. The ejection holes 45 are also provided at required places.

The outer cylinder 33 is formed to have a predetermined gap between the peripheral wall of the inner cylinder 32 and the outer surface of the closing wall 39 so as to cover the entire outer surface. After extending from the open end side of the inner cylinder 32 into the closing wall 46, the outermost wall of the combustion chamber 31 is connected to the outermost wall of the combustion chamber 31 via the connecting pipe 47. A cooling passage 48 is provided to communicate therewith. An inlet of the cooling passage 48, that is, an end portion 49 located on the open end side of the inner cylinder 32 communicates with an air compressor driven by a gas turbine.

The air flow guide mechanism 37 includes an outer cylinder 33 and an inner cylinder 3.
2 is mainly constituted by an air flow guide path 50 formed therebetween. The air flow guide path 50 extends between the inner cylinder 32 and the outer cylinder 33 from the open end side of the inner cylinder 32 to the closing wall 39 and the closing wall 46.
Between the communication holes 5 formed in the closing wall 39.
1 communicates with the uppermost stream portion of the combustion chamber 31. The inlet of the air flow guide path 50, that is, the end 52 located on the open end side of the inner cylinder 32, communicates with the air compressor driven by the gas turbine.

On the other hand, the combustion gas extraction mechanisms 38a, 38b
Are configured as follows. That is, by locally reducing the inner diameter of the outer cylinder 33, the middle of the air flow guide path 50, specifically, between the peripheral wall of the inner cylinder 32 and the peripheral wall of the outer cylinder 33, A speed increasing mechanism 54 that narrows the flow cross-sectional area of a part surrounding the basin area and a part that surrounds the upstream area slightly below the downstream area of the combustion chamber 31 to increase the flow velocity of the air flow 53, and a speed increasing mechanism using the peripheral wall of the inner cylinder 32. 54, which is provided at a position facing the speed increasing region and utilizes the difference between a high pressure equal to almost the total pressure of the high temperature combustion gas in the inner cylinder 32 and a low static pressure of the speed increasing flow. Inner cylinder 3
And an extraction path 55 that joins a part of the high-temperature combustion gas in the air stream 2 to the accelerated air flow.

In this example, a portion of the peripheral wall of the inner cylinder 32 other than the portion where the speed increasing mechanism 54 is provided,
Part of the airflow flowing through the airflow guide path 50 is directly transferred to the inner cylinder 3.
A plurality of holes 59 leading into the inside 2 are provided.

With such a configuration, the compressed air sent out from the air compressor is distributed to three systems as shown by the thick arrow 56 in the drawing, and the cooling flow path 40, the air flow guide path 50, It is supplied to the cooling channel 48.

The cooling air 4 supplied to the cooling passage 40
3 cools the inner cylinder 32 from the inside while flowing. A part flows into the combustion chamber 31 for dilution through the hole 44, and a part is blown out from the blowing hole 45 to be used for film cooling of the inner cylinder 32, and the rest is provided on the closing wall 39. The air flows into the most upstream portion of the combustion chamber 31 through the communication hole and is used as a part of the combustion air.

The cooling air 5 supplied to the cooling passage 48
7 cools the outer cylinder 33 from inside while flowing. Finally, after flowing through the closed wall 46, the air flows into the uppermost stream portion of the combustion chamber 31 via the communication pipe 47 and is used as a part of the combustion air.

On the other hand, a part of the air flow 53 supplied to the air flow guide path 50 flows directly into the inner cylinder 32 through the hole 59, and a part of the speed increasing mechanism 54 in the combustion gas extracting mechanisms 38b and 38a. , The flow velocity is remarkably increased, and finally flows into the uppermost stream portion of the combustion chamber 31 through the communication hole 51 provided in the closing wall 39 and is supplied to the combustion air.

Therefore, when the fuel 34 is supplied into the combustion chamber 31 through the fuel supply pipe 35 and ignited, the combustion chamber 31
Combustion is performed continuously within the chamber. The combustion gas 58 generated by this combustion is guided to a gas turbine and used for generating power.

By the way, as described above, the air flow guide path 5
The air flow 53 supplied to 0 significantly increases the flow velocity when passing through the portion of the speed increasing mechanism 54. An extraction path 55 is provided on the peripheral wall of the inner cylinder 32 facing the speed increasing region. For this reason,
The ejector action between the accelerated flow and the extraction path 55 or the difference between the high pressure substantially equal to the total pressure of the high-temperature combustion gas in the inner cylinder and the low static pressure of the accelerated flow reduces the temperature of the high-temperature combustion gas in the combustion chamber 31. The portion is extracted and merges with the accelerated airflow. Therefore, at the position where the combustion gas extraction mechanisms 38a and 38b are provided, the high-temperature combustion gas joins the airflow 53.

As described above, when a part of the high-temperature combustion gas merges with the air flow 53, the air flow 53 is automatically preheated to, for example, about 1000 ° C. by receiving heat supply from the high-temperature combustion gas. The air flow 53 is sent as combustion air to the uppermost stream portion of the combustion chamber 31 through the communication hole 51 provided in the closing wall 39. Therefore, high-temperature air combustion is realized here.

In this case, a so-called self-preheating system is employed, in which the combustion air is preheated to a high temperature by using a part of the high-temperature combustion gas generated by the combustion device itself.
A high-temperature air combustion system can be realized in a state in which the entire apparatus is simplified and miniaturized as compared with an apparatus having a combustion section for air preheating and a combustion section for main combustion.

Also, as in this example, the air flow guide path 50
Is combined with an extraction path 55 provided on the peripheral wall of the inner cylinder 32, and the ejector action or the high pressure equal to almost the total pressure of the high-temperature combustion gas in the inner cylinder 32 is increased by this combination. With a structure in which a part of the high-temperature combustion gas is combined with the air flow 53 by utilizing the difference between the low static pressure of the flow and the air flow 53, the air flow can be self-preheated without the need for a movable part, so that stability is improved And durability can be sufficiently satisfied.

In addition, since the combustion air is not preheated through the heat exchange wall, the components of the inner cylinder 32 and the outer cylinder 33 can be sufficiently cooled in this example. Therefore, a high-temperature air combustion system can be realized without using expensive heat-resistant materials, and an existing combustion device can be easily applied by only partially changing the structure.

In the above-described example, the closing walls 39, 46 are provided in the inner cylinder 32 and the outer cylinder 33 from the respective open ends.
Cooling passages 40 and 48 are provided, which extend to the inside and communicate with the most upstream portion of the combustion chamber 31, respectively, but as shown in FIG. The cooling passages 40a and 48a may be provided only in the portions where the cooling channels are provided.

In addition, depending on the relationship between the temperature and the heat resistance of the material used, an outer cylinder 33a in which the cooling flow path is omitted may be used as shown in FIG. The inner cylinder 32a in which the path is omitted may be used, or the inner cylinder 32a and the outer cylinder 33a in which both cooling channels are omitted as shown in FIG. 6 may be used.

Further, in the above-described example, the present invention is applied to a combustion device for a gas turbine device. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to combustion devices for various uses. .

[0038]

As described above, according to the present invention, low NOx combustion can be realized in a state where the apparatus is simplified, downsized, and reduced in cost.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a combustion device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing the device in a locally extracted manner.

FIG. 3 is a schematic longitudinal sectional view of a combustion device according to a second embodiment of the present invention.

FIG. 4 is a schematic longitudinal sectional view of a combustion device according to a third embodiment of the present invention.

FIG. 5 is a schematic longitudinal sectional view of a combustion device according to a fourth embodiment of the present invention.

FIG. 6 is a schematic longitudinal sectional view of a combustion device according to a fifth embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a combustion device attached to a general gas turbine device.

FIG. 8 is a schematic configuration diagram of a gas turbine device provided with a high-temperature air combustion type combustion device.

[Explanation of symbols]

 31 combustion chamber 32, 32a inner cylinder 33, 33a outer cylinder 34 fuel 36 fuel guide mechanism 37 air flow guide mechanism 38, 38a, 38b combustion gas extraction mechanism 39, 46 closing wall 40, 40a, 48, 48a Cooling flow path 42 Projection 43, 57 Cooling air 44, 59 Hole 45 Spout hole for film cooling 50 Air flow guide path 51 Communication hole 53 Air flow 54 Speed increase Mechanism 55 Extraction path 58 Combustion gas

Continuation of front page (72) Inventor Masafumi Fukuda 1-1-1, Shibaura, Minato-ku, Tokyo Inside the head office of Toshiba Corporation

Claims (5)

[Claims] 1. A combustion cylinder forming a combustion chamber, fuel guide means for guiding fuel supplied for combustion into the combustion cylinder, and fluid guide means for guiding a fluid required for combustion into the combustion cylinder. A combustion gas extracting means for combining a part of the combustion gas generated in the combustion cylinder with a fluid guided by the fluid guiding means. 2. An inner cylinder forming a combustion chamber; an outer cylinder disposed outside the inner cylinder; fuel guide means for guiding fuel supplied to the inner cylinder for combustion; Fluid guiding means for guiding a fluid necessary for combustion into the inner cylinder through the outer cylinder; and a part of the combustion gas generated in the inner cylinder, the A combustion gas extracting means for merging with a fluid flowing therethrough. 3. The combustion gas extracting means is provided between the inner cylinder and the outer cylinder to increase the flow speed of the fluid, and the combustion gas extracting means is provided at a peripheral wall of the inner cylinder. Is provided at a position facing the speed-increasing region by the ejector action with the speed-increasing means or the difference between a high pressure equal to almost the total pressure of the high-temperature combustion gas in the inner cylinder and a low static pressure of the speed-increasing flow. 3. The combustion apparatus according to claim 2, further comprising an extraction passage for joining a part of the combustion gas in the cylinder to the speed-increasing fluid. 4. The combustion apparatus according to claim 2, wherein the inner cylinder has a flow passage through which a cooling fluid flows in a peripheral wall. 5. A flow path provided in a peripheral wall of the inner cylinder has a projection on an inner surface thereof.
The combustion device according to claim 1.