JP2001090939A - Structure of combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the structure of a combustor for a gas turbine, which restrains the vibration of air in an air suction wheel chamber for the combustor highly reliably at a low cost. SOLUTION: One sheet of thin flat sheet 10 is attached to the inner wall of a casing 100 by studs 1 through a gap while the thin flat sheet resonates with the vibration of air whereby the energy of the vibration of air is absorbed. The stud is constituted of a bolt 2, welded to the casing, and two pieces of nuts 3, 4, welded to the bolt after screwing them to the bolt, while the thin flat sheet is retained through two pieces of nuts. A plurality of thin flat sheets can be laminated to absorb the energy of vibration of air by friction, the size of the thin flat sheet can be changed to absorb the energy of vibration of air having various frequencies, a three-dimensional formed matter can be welded directly to the inner wall of the casing and a hole can be bored on the thin flat sheet or the three-dimensional formed matter to pass air through the hole and facilitate the generation of vibration in the thin flat sheet or the three- dimensional formed matter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustor structure, and more particularly to a gas turbine combustor structure.

[0002]

2. Description of the Related Art Combustors are used in various fields, but with the stricter regulations on exhaust gas, especially with the stricter control of NOx, combustion with a large mixture ratio of air to fuel, that is, lean combustion must be performed. Is gone. When lean combustion is performed in this manner, combustion fluctuations are likely to occur, and when combustion fluctuations occur, pressure fluctuations of the combustion gas occur. By the way, for example, in a gas turbine, as shown in FIG. 10, a casing 100 separately covers the outside of a plurality of combustor inner cylinders (also referred to simply as combustors) 200 in which combustion is performed, and A space called a combustor intake casing 300 is formed between the inner cylinder 200 and the casing, and the air discharged from the compressor enters the combustor intake casing 300, and from there, the inside of the combustor is formed. Cylinder 200
And the fuel supplied from the fuel nozzle 400 is mixed and burned, and the combustion gas is directed to the turbine section.

[0003] The combustor intake casing 300 is generally annular, but has an axial length exceeding 2 m and a radial width of the annular exceeding 1 m is not unusually large. Therefore, the large intake casing forms a sound field, and when a combustion variation occurs and a pressure variation in the combustor inner cylinder 200 occurs, the pressure variation is transmitted to the combustor intake casing 300 and the sound field is reduced. The frequency component corresponding to the natural frequency is amplified and the combustor inner cylinder 2
00, the pressure fluctuation in the combustor inner cylinder 200 further increases. As a result, the amount of fuel and air flowing into the combustor also fluctuates, and grows to larger and larger combustion fluctuations.
A so-called combustion oscillation phenomenon occurs. JP-A-11-625
No. 49 proposes attaching a sound absorbing material to the inner surface of the casing 100 in order to suppress the air vibration amplifying action of the intake casing space 300.

[0004]

However, the combustor intake casing 300 is subject to severe conditions such as a temperature of 500 ° C. and a pressure of 25 ata, and is located upstream of a high-speed rotating turbine chamber. And the sound absorbing material
It is required not to be broken or scattered even under the above-mentioned severe conditions. In practice, it is very difficult to obtain a sound absorbing material that satisfies this requirement at an appropriate cost. In view of the above problems, an object of the present invention is to provide a combustor structure of a gas turbine in which vibration of air in a combustor intake casing is suppressed with high durability and at low cost.

[0005]

According to the first aspect of the present invention, there is provided a gas turbine combustor structure in which a combustor inner cylinder which performs combustion inside is covered with a casing via an intake casing space. Further, there is provided a combustor structure in which a planar damping material that resonates with air vibration in an intake cabin space and absorbs air vibration energy is attached to an inner wall of a casing with a mounting member through a gap. In the combustor structure configured as described above, the energy of the air vibration in the intake cabin space is absorbed by the planar damping material that resonates with the air vibration in the space.

According to a second aspect of the present invention, there is provided a combustor structure according to the first aspect, wherein the planar damping member is a single-layer thin plate. In the combustor structure thus configured, the thin flat plate resonates and absorbs the energy of the air vibration in the space.
According to a third aspect of the present invention, there is provided the combustor structure according to the first aspect of the present invention, which is a thin flat plate in which a plurality of planar damping members are stacked. In the combustor structure configured as described above, the energy of the air vibration in the intake casing space is also absorbed by the friction between the stacked thin plates. According to a fourth aspect of the present invention, there is provided the combustor structure according to the second or third aspect of the present invention, which uses thin plates having different sizes. In the combustor structure configured as described above, the thin flat plates having different sizes absorb and attenuate the energy of the air vibration having different frequencies.

According to a fifth aspect of the present invention, in the first aspect of the invention, the mounting member is a stud, and the stud is screwed to the bolt welded to the inner wall of the casing and the bolt while sandwiching the thin plate therebetween. A combustor structure is provided that comprises two nuts welded to the combustor.

According to a sixth aspect of the present invention, there is provided the combustor structure according to the first aspect of the invention, wherein the planar damping material is a three-dimensional molded member formed to include a space including the mounting member. You. In the combustor structure configured as described above, the three-dimensional molded member resonates and absorbs the energy of the air vibration in the intake cabin space. In the invention of claim 7, in the invention of claim 6, the three-dimensional molded member is a single three-dimensional molded member including one independent spatial layer, and a plurality of single three-dimensional molded members are attached to the inner wall of the casing. A combustor structure is provided. According to an eighth aspect of the present invention, there is provided the combustor structure according to the seventh aspect, wherein the single three-dimensional molded member is a box-shaped three-dimensional molded member forming a closed space.

According to a ninth aspect of the present invention, there is provided the combustor structure according to the sixth aspect, wherein the three-dimensionally formed member is a continuous three-dimensionally formed member in which a plurality of independent space layers are formed in advance. According to a tenth aspect of the present invention, there is provided the combustor structure according to the sixth aspect, wherein the volume of the space included in the three-dimensional molded member fixed to the inner wall of the casing is not uniform. In the combustor structure configured as described above, the three-dimensionally formed members having different sizes absorb and attenuate the energy of vibrations having different frequencies.

According to an eleventh aspect of the present invention, there is provided the combustor structure according to the first aspect of the present invention, wherein the planar damping member has holes formed therein so as to communicate spaces on both sides of the planar damping member. In the combustor structure configured as described above, air moves between the spaces on both sides of the planar damping material, and the vibration of the planar damping material is facilitated.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a combustor structure according to an embodiment of the present invention; FIG. I do. Each drawing shows an example in which the present invention is applied to the portion indicated by A in FIG. 10, but is applied not only to this portion but also to all the portions drawn by thick solid lines in FIG. 10 as much as possible. I have.

FIG. 1 is a view showing a planar damping material according to a first embodiment and a method of mounting the same. Referring to FIG. 1, the planar damping material is provided inside a casing 100 via a stud 1. One thin flat plate 10 as a material is attached. It should be noted that the casing 100 actually has a thickness of more than 10 cm, whereas the thin flat plate 10 has a thickness of less than 1 mm. Therefore, FIG. 1 (and FIGS. The flat plate 10 and the stud 1 are exaggerated.

Here, a method of attaching the thin flat plate 10 with the stud 1 will be described. First, the bolt 2 is welded to the casing 100, the nut 3 is screwed to the bolt 2 and positioned at a predetermined position. Weld to bolt 2. In this state, the thin plate 10 is engaged with the bolt 2 so that the bolt 2 passes through a mounting hole (not shown) formed in the thin plate 10 in advance, and then the inner nut 4
Is screwed into the bolt 2 and tightened. Then, the inner nut 4 is welded to the bolt 2. By doing so, the nuts and bolts are prevented from dropping, reaching the downstream turbine chamber and destroying the turbine blades and the like. In addition,
Stud 1 includes bolt 2, outer nut 3, and inner nut 4.
1 shows the entire mounting element consisting of

The first embodiment is configured as described above, and the thin plate 10 is disposed inside the casing 100 via the separation space 110. Therefore, the intake casing 3 due to the pressure fluctuation generated in the combustor inner cylinder 200
The vibration of the air in 00 is absorbed and attenuated by the thin flat plate 10. Therefore, an increase in pressure fluctuation in the combustor inner cylinder 200 is prevented, and a vicious cycle of increased combustion instability can be broken, leaner combustion can be performed, and NOx can be reduced. It should be noted that since one thin flat plate 10 cannot completely cover the inside of the casing 100, several thin flat plates 10 are used. In this case, all the thin flat plates 10 having the same size are used. Instead, use thin plates of different sizes. If the magnitudes are different, the frequencies of absorption and attenuation are different, so that vibrations of various frequencies can be absorbed and attenuated. The frequency of the target vibration is a low frequency vibration of several tens to hundreds Hz.

Next, a second embodiment shown in FIG. 2 will be described. In the second embodiment, the thin flat plate 10 is a perforated plate having holes 11. In the second embodiment, the same effect as that described in the first embodiment can be obtained.
By allowing air to flow between the space 10 and the space inside the thin plate 10, the thin flat plate 10 can be easily shaken, thereby improving the damping performance or changing the characteristics.

Next, a third embodiment shown in FIG. 3 will be described. In the third embodiment, a plurality of thin flat plates 10 are used. In the second embodiment, the same effect as that described in the first embodiment can be obtained. However, since a plurality of thin flat plates rub against each other when vibrating, the friction increases the damping effect. There is.

Next, a fourth embodiment shown in FIG. 4 will be described. In the fourth embodiment, a thin flat plate 1 is used.
0 is used by laminating a plurality of sheets. In the fourth embodiment, a plurality of thin plates 10 are stacked and used similarly to the third embodiment, but the size or the number of stacked plates is changed in various ways. By doing so, in addition to the effect obtained in the third embodiment, an advantage that vibrations of various frequencies can be absorbed and attenuated is added. In the third and fourth embodiments,
As in the second embodiment, a perforated plate can be used, but instead, a portion to which the thin plate 10 is not properly attached may be provided.

Next, a fifth embodiment shown in FIG. 5 will be described. In the fifth embodiment, instead of attaching a thin flat plate to the casing 100 as in the first to fourth embodiments, a three-dimensional molded member 20 that is three-dimensionally molded from a thin plate in advance is attached. The three-dimensional molded member 20 has a flat part 21 and a side part 22, and the end of the side part 22 can be directly attached to the casing by welding, so that the stud 1 used in the first to fourth embodiments is used. Is unnecessary. The fifth embodiment is configured as described above, and the three-dimensional molded member 2
0, particularly the plane portion 21, absorbs the vibration of the air in the intake casing 300, so that the same basic effects as described in the first embodiment can be obtained.

In the sixth embodiment shown in FIG. 6, three-dimensionally shaped members 20 of various sizes are attached to a casing 100. In addition to the effects of the fifth embodiment, various frequencies are provided. Has the advantage of being able to cope with the vibration of

FIG. 7 shows a three-dimensional molded member 24 according to the seventh embodiment. The three-dimensional molded members 20 according to the sixth embodiment are independent molded members each including one space. In contrast, the three-dimensional molded member 2 of the seventh embodiment
Reference numeral 4 denotes a continuous three-dimensionally formed member formed so as to include a plurality of spaces. Therefore, the mounting operation is easy.

FIG. 8 shows an eighth embodiment, in which a three-dimensional molded member 25 of the eighth embodiment is a box-shaped closed space three-dimensional molded member. There is an advantage that it is more robust than the three-dimensional molded member 20 of the embodiment. In the ninth embodiment, box-shaped three-dimensional shaped members 25 of various sizes are attached to the casing 100, and can cope with vibrations of various frequencies in addition to the effects of the eighth embodiment. It has the advantage that. In addition,
In each of the fifth to eighth embodiments, it is possible to provide a hole in each three-dimensional molded member as in the second embodiment, or to form a three-dimensional molded member with a perforated plate.

The present invention relates to a combustor structure of a gas turbine, and the embodiment has been described with the gas turbine. However, the present invention can be applied to a combustor structure similar to the gas turbine, The shape and the mounting method can be modified without departing from the spirit of the present invention, and the present invention includes those modifications.

[0023]

According to the invention described in each of the claims, in a combustor structure of a gas turbine in which a combustor inner cylinder which performs combustion inside is covered with a casing via a large space, air inside the space is provided. A planar damping material that converts the vibration into its own planar vibration and absorbs it is placed away from the inner wall of the casing, and the vibration of air in the space is absorbed by the planar damping material,
Attenuated. Therefore, the vibration of the combustor inner cylinder increases,
The vicious cycle of increased combustion instability can be broken, leaner combustion can be achieved and NOx can be reduced, but the structure is simple, resulting in high durability and low cost . In particular, if the planar damping material is formed of a perforated plate as described in claim 2, gas can flow on both sides of the planar damping material, and the damping effect is increased. In particular, when the planar damping material is formed by laminating a plurality of thin plates, the vibration damping effect is increased by the friction between the plurality of thin plates. In particular, if a three-dimensionally formed planar damping material is used as in claims 5 to 8, no mounting member is required, so that the number of parts is small, and the number of processing steps and mounting steps can be reduced. In particular, if a continuous three-dimensionally formed member as described in claim 7 is used, work is particularly easy. In addition, when the planar damping materials having different sizes are used, vibrations having different frequencies can be absorbed and attenuated.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a characteristic portion of a gas turbine combustor structure according to a first embodiment.

FIG. 2 is a diagram illustrating a characteristic portion of a gas turbine combustor structure according to a second embodiment.

FIG. 3 is a diagram showing a characteristic portion of a gas turbine combustor structure according to a third embodiment.

FIG. 4 is a diagram showing a characteristic portion of a gas turbine combustor structure according to a fourth embodiment.

FIG. 5 is a diagram showing a characteristic portion of a gas turbine combustor structure according to a fifth embodiment.

FIG. 6 is a diagram showing a characteristic portion of a gas turbine combustor structure according to a sixth embodiment.

FIG. 7 is a diagram illustrating a continuous three-dimensional molded member used in a seventh embodiment.

FIG. 8 is a diagram showing a characteristic portion of a gas turbine combustor structure according to an eighth embodiment.

FIG. 9 is a diagram showing a characteristic portion of a gas turbine combustor structure according to a ninth embodiment.

FIG. 10 is a view showing a combustor structure of a gas turbine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Stud 10 ... Thin flat plate 11 ... Hole 20 ... (Independent) three-dimensional molded member 24 ... (Continuous) three-dimensional molded member 25 ... (Box-shaped) three-dimensional molded member 100 ... Casing 200 ... Combustor inner cylinder 300 ... Intake casing 400 … Fuel nozzle

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Keizo Onishi 2-1-1, Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. No. 1 Inside Mitsubishi Heavy Industries, Ltd. Takasago Factory

Claims (11)

[Claims] 1. A gas turbine combustor structure in which a combustor inner cylinder which performs combustion inside is covered with a casing via an intake casing space, wherein the combustor structure resonates with air vibration in the intake casing space. A combustor structure, wherein a planar damping material that absorbs energy of air vibration is attached to an inner wall of a casing with a mounting member through a gap. 2. The combustor structure according to claim 1, wherein the planar damping material is a single-layer thin flat plate. 3. The combustor structure according to claim 1, wherein the thin plate is a thin plate in which a plurality of planar damping members are stacked. 4. The combustor structure according to claim 2, wherein thin plates having different sizes are used. 5. The mounting member is a stud. The stud is bolted to the inner wall of the casing, screwed to the bolt while sandwiching a thin plate therebetween, and then welded to the bolt.
The combustor structure according to claim 1, comprising two nuts. 6. The combustor structure according to claim 1, wherein the planar damping member is a three-dimensional molded member including a mounting member and molded to include a space. 7. The three-dimensional molded member is a single three-dimensional molded member including one independent spatial layer, and a plurality of single three-dimensional molded members are attached to an inner wall of the casing. 3. The combustor structure according to 1. 8. The three-dimensionally formed single member is a box-shaped three-dimensionally formed member forming a closed space.
3. The combustor structure according to 1. 9. The combustor structure according to claim 6, wherein the three-dimensional molded member is a continuous three-dimensional molded member in which a plurality of independent space layers are formed in advance. 10. The combustor structure according to claim 6, wherein the volume of the space included in the three-dimensional molded member fixed to the inner wall of the casing is unequal. 11. The combustor structure according to claim 1, wherein holes are formed in the planar damping material to communicate spaces on both sides of the planar damping material.