JP2000145480A - Cooling structure of gas turbine combustor pilot cone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow adjustment of flow rate, pressure loss and heat transfer coefficient and improve cooling effect. SOLUTION: The wall of the combustor pilot cone has a dual structure formed by bonding the outer side plate 1 and the inner side plate 4. Air inlet holes 3 linearly aligned are formed in the outer side plate 1. The groove 2 is processed inside so as to be closed at the bonded surface of the inner side plate 4, generating the air flow passage. On the inner side plate 4, air exhaust holes 5 are linearly arranged at the positions of the groove 2. The groove 2 communicates with the air inlet holes 3 and the air exhaust holes 5, which has a width expanded in a tapered manner in the direction from the hole 3 toward the hole 5. The width in the depth direction is kept constant or changed in a tapered manner such that the sectional shape of the groove is two- dimensionally or three-dimensionally changed. The cooling air flows into the groove 2 through the hole 3 formed in the rear side of the pilot cone. It flows to cool the wall at both sides and then expands, which may increase the flow rate and the pressure loss. However, as the flow passage is broadened at the hole 5, the increase in the flow rate is prevented, thus reducing the pressure loss.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a pilot cone of a gas turbine combustor, and more particularly, to a structure in which cooling air is circulated through a wall of the pilot cone to increase the cooling effect.

[0002]

2. Description of the Related Art FIGS. 15A and 15B show a general structure of a gas turbine combustor and a cooling method thereof. FIGS. 15A and 15B show an air cooling method and FIG. 15C shows a steam cooling method. It is an example. To summarize these outlines, FIG.
In (a), 100 is a pilot nozzle for injecting and burning pilot fuel, 101 is a main nozzle, which is called an annular nozzle system, and a plurality of nozzles are arranged around a pilot inner cylinder 102 to inject the main fuel. The main fuel is ignited and burned by the combustion of the pilot fuel in the pilot inner cylinder 102. 103 is a main inner cylinder, 104 is a connection cylinder, and 105 is a transition piece, which guides combustion gas, which has become hot due to combustion of the main fuel, to a combustion gas passage of a gas turbine. Reference numeral 106 denotes an air bypass valve for releasing excess air from the compressor from the bypass duct through the transition piece 105 to the gas turbine combustion gas passage at a low load. In such a type of combustor, the inside of the wall of the transition piece 105 is shown in FIG.
As described later, a cooling structure for cooling by air is employed.

[0005] The combustor shown in FIG. 15B is called a multi-nozzle system, in which 107 is a pilot nozzle, around which a plurality of main nozzles 108 are arranged, and an inner cylinder 109.
The main fuel is injected from the main nozzle 108 into the inside, and the main fuel is ignited and burned by the combustion of the pilot fuel from the pilot nozzle 107. 110 is a transition piece, and 106 is an air bypass valve. In the combustor having such a structure, the inside of the wall of the transition piece 110 is cooled by air as described later with reference to FIG.

[0004] The combustor shown in FIG. 15C is an example in which a steam cooling system is adopted for a multi-nozzle combustor. In the figure, 111 is a pilot nozzle, 112 is a plurality of main nozzles arranged around it, and 113 is a swirler holder. Reference numeral 114 denotes a transition piece integrated with an inner cylinder, which is connected to the swirler holder 113 and guides a high-temperature combustion gas to a combustion gas passage of a gas turbine. The transition piece 114 is provided with a number of cooling steam passages inside the wall, 115 is a steam supply passage, and 116 and 117 are steam recovery passages. The cooling steam 200 is supplied to the passage in the wall of the transition piece 114 from the steam supply passage 115, flows through the wall and cools the wall, and the steam recovery passages 116 and 117 provided at both ends, respectively.
And is returned to the steam generation source for effective use.

FIG. 16 is a perspective view showing a part of the wall of the combustor transition pieces 105 and 110 of FIGS. 15A and 15B. In the figure, the wall has a double structure,
0 and the inner plate 123 are joined together. The outer plate 120 constitutes the outer surface of the transition piece, and a plurality of grooves 121 having a constant cross-sectional shape are formed so as to be arranged substantially in the flow direction of the combustion gas. It is closed by a face. Each groove 1 is formed on the outer plate 120.
21 are provided respectively with air suction holes 122,
The air suction holes 122 are provided at predetermined intervals along one groove 121.

[0006] An air discharge hole 124 is formed in the inner plate 123. The air discharge holes 124 are arranged so as to communicate with the openings of the grooves 121 formed in the outer plate 120 joined to each other, and are arranged along the grooves 121 at an intermediate position between the two air suction holes 122. I have. The outer plate 120 and the inner plate 123 are joined using a heat-resistant material such as Hastelloy X, Tomiloy, or SUS material. This joining is performed by diffusion welding in which hot pressing is performed by heating and pressing.

In such a wall structure, cooling air 300 passes from a number of air suction holes 122 from around the transition piece.
Each of the air flows into the groove 121, flows through the groove 121, cools the wall surface, and the air 30 flows from the air discharge hole 124 of each groove 121.
It flows out into the transition piece as 1f. A large number of such grooves 121, air suction holes 122 and air discharge holes 124 communicating with the grooves 121 are provided around the entire wall of the transition piece. The entire circumference is cooled, and the air flows out into the transition piece through the air discharge holes 124 and is mixed with the combustion gas.

FIG. 17 is a sectional view of a pilot cone provided at the tip of a pilot nozzle of the combustor described with reference to FIGS. 15 (b) and 15 (c), and shows an upper half thereof.
In the figure, a pilot nozzle is provided at the center of the inner cylinder of the combustor, and a pilot cone 130 is attached to the tip thereof. The pilot cone 130 is open in a trumpet shape as shown in FIG.
A guide ring 131 for supporting the pilot cone 131 is provided, and the guide ring 131 is fixedly supported around the connection portion 132 by welding at predetermined intervals.

At the center of the pilot cone 131, fuel injected from the pilot nozzle burns and flows out as a high-temperature combustion gas 140, flows out along the tapered wall surface of the cone, and flows into the inner surface of the wall. Are constantly exposed to hot combustion gases. Further, as described above, a plurality of main nozzles are disposed around the pilot cone 130, and the fuel flowing out is ignited by the flame 140 of the combustion gas flowing out of the pilot cone 130 and burns. The outer surface of 130 and the guide ring 131 are also exposed to high temperatures.

Reference numeral 141 denotes an airflow, which flows out to the outlet through a gap between the pilot cone 130 and the guide ring 131. This air 141 is originally the pilot cone 1
A flame is generated at the outlet end of the nozzle 30 and is discharged to prevent the flame from continuing.
Is the back of the pilot cone 130 and the guide ring 131
In the process of flowing through the gap between the pilot cone 1 and the pilot cone 1
Holds 30 cooling. As described above, in the conventional gas turbine combustor, the transition piece of the combustor is provided with a cooling groove by a double structure and cooled by flowing air or steam, and the pilot cone 130 is cooled by the air 1 flowing on the back side of the cone wall surface.
It was cooled at 41.

[0011]

As described above, the cooling of the conventional gas turbine combustor is performed by using a cooling system in which air or steam is supplied as a double structure in which a cooling groove is provided in the wall of a transition piece. The cone has adopted a method of cooling by air passing behind the wall of the cone. However, in recent years, the temperature of the gas at the inlet of the gas turbine has increased, and the operating environment of the combustor has become severer year by year. In particular, in a multi-premixed combustor, combustion oscillation is a problem, and it has been confirmed that increasing the proportion of pilot fuel is effective as a measure to reduce combustion oscillation. This leads to an increase in the heat load on the wall of the pilot cone, and the conventional structure lacks cooling, and it is necessary to increase the cooling effect.

Therefore, in the present invention, in order to enhance the cooling effect of the pilot cone of the gas turbine combustor, the same cooling wall structure as the cooling structure of the transition piece may be employed for the cooling structure of the pilot cone wall. Improved air cooling structure,
An object of the present invention is to provide a pilot cone cooling structure that enhances the effect of air cooling.

[0013]

The present invention provides the following means (1) to (11) to solve the above-mentioned problems.

(1) A plurality of cooling air passages are provided around the inside of the wall of the pilot cone of the gas turbine combustor in the flow direction of the combustion gas, and each passage has an air suction hole opened on the back side of the pilot cone and a cooling air passage. The air discharge holes opened inside the pilot cone are sequentially arranged at predetermined intervals to communicate with each other, and the section between the air suction hole and the air discharge hole of each of the passages has a width or depth of the passage cross section, or both. The cooling structure of the pilot cone of a gas turbine combustor, characterized in that the air flow smoothly changes in the direction of air flow.

(2) In the above (1), a cooling structure in which a plurality of turbulators are provided in a predetermined section of the passage so as to be substantially orthogonal to the direction of air flow.

(3) The cooling structure according to the above (1), wherein a plurality of concave grooves are provided on the wall surface of the predetermined section of the passage so as to be substantially orthogonal to the air flow direction.

(4) A plurality of rows of cooling air passages are provided around the inside of the wall of the pilot cone of the gas turbine combustor in the direction of flow of the combustion gas. The air discharge holes that open inside the pilot cone are sequentially arranged at predetermined intervals so as to communicate with each other, and the section between the air suction hole and the air discharge hole of the passage has a cross-sectional area of the same section as the section where the cross-sectional shape remains unchanged. A cooling structure for a pilot cone of a gas turbine combustor, characterized by alternately communicating a section with a narrow flow path and a shape-invariant section.

(5) A plurality of rows of cooling air passages are provided around the inside of the wall of the pilot cone of the gas turbine combustor in the flow direction of the combustion gas, and each of the passages has an air suction hole opened on the back side of the pilot cone and a cooling air passage. A cooling structure for a pilot cone of a gas turbine combustor, wherein air discharge holes opened inside the pilot cone are sequentially arranged at predetermined intervals so as to communicate with each other, and the passage is meandering in a wave shape.

(6) In any one of the above (1), (4) and (5), the air discharge hole is inclined so that air flows out toward the inside of the pilot cone in the flow direction of the pilot combustion gas. Cooling structure provided.

(7) In any one of the above (1), (4) and (5), a cover is provided around the outlet of the air discharge hole so that air flows out in the flow direction of the pilot combustion gas. Cooling structure.

(8) In any one of the above (1), (4), and (5), the arrangement of the air suction holes and the air discharge holes in each of the passages is such that the flow direction of the air flowing through the passages is that of the adjacent passages. A cooling structure configured to be opposite to the direction of air flow.

(9) In any one of the above (1), (4), and (5), the terminal end of the passage connecting portion at the wall connecting portion may correspond to the terminal end and extend inward from the back side of the wall of the pilot cone. A cooling structure characterized in that each of the holes communicates with the middle of a hole that penetrates the hole, and a lid is inserted into each of the holes from either the back side or the inside and closed.

(10) A plurality of dimples projecting in a conical shape from the back side to the inside are arranged on the wall of the pilot cone of the gas turbine combustor, and the direction in which the pilot combustion gas flows in the conical portion of the dimple is provided. A cooling structure for a pilot cone of a gas turbine combustor, wherein a hole through which cooling air is ejected from the back side toward the inside is provided.

(11) In the pilot cone of a gas turbine combustor whose periphery is supported by a guide ring, a plurality of projecting fins are provided in the front-rear direction between the guide ring and the pilot cone on the outer periphery on the back side of the pilot cone. A cooling structure for a pilot cone of a gas turbine combustor, wherein the cooling structure is formed.

The conventional cooling structure of the pilot cone is a structure in which air is circulated to the back side of the pilot cone, and when the ratio of the pilot fuel is increased, the cooling is insufficient. (1) of the present invention
In the above, a cooling passage is provided inside the wall of the pilot cone, cooling air flows into the passage from the air suction hole from the back side of the pilot cone, cools the inside of the wall, and flows out from the air discharge hole to the inside of the pilot cone. .
Further, since the width and depth of the cross-sectional shape of the passage are changed two-dimensionally or three-dimensionally, the flow velocity can be changed depending on the location of the wall surface having a different temperature distribution, whereby the pressure loss can be reduced. The flow velocity, pressure loss, and heat transfer coefficient can be adjusted according to the cooling conditions of the cone, which enables the design of cooling passages under optimal conditions, improving the temperature distribution, reducing thermal stress, and causing cracks, etc. Can be prevented, and the reliability of the combustor is improved.

In (2) and (3), the heat transfer coefficient can be further improved by agitating the flow of the cooling air by the action of the turbulator and the depression. In (4), the flow path of the passage is orificed. The flow rate can be adjusted by narrowing or expanding the flow path by the effect. In (5), the flow path can be meandered in a waveform to increase the flow path length, and it is desired to enhance the cooling effect depending on the location of the pilot cone. This is particularly effective in such cases.

In the method (6), when air is discharged from the air discharge hole, the air is discharged in the combustion gas flow direction along the inner wall surface of the pilot cone, and the air is effectively cooled in the vicinity of the discharge hole into the pilot cone. Can be drained. In (7), the same effect as (6) can be realized by providing a cover. In (8), since the air flows in the adjacent passages are in opposite directions, the imbalance in cooling of the pilot cone wall surface is eliminated. In the case where the wall of the pilot cone is formed by welding, the passage is terminated at an intermediate point in this connection portion, and there may be a portion where the cooling air does not flow and stays. In this case, by providing a through hole at the end of the passage and closing the outside or inside with a lid, air can be sucked in from the outside or discharged into the pilot cone, and it is also effective at the connection part Cooling is possible.

In the invention of (10), a large number of dimples are arranged on the wall of the pilot cone, and the cooling air flows out from the hole of the conical portion of the dimple in the flow direction of the combustion gas, and flows along the inner surface of the wall. The cooling air flows to cool the film. This air flow forms a film layer of cooling air on the wall surface, and the wall surface is effectively cooled.

Further, in (11) of the present invention, the fins are provided on the back side of the pilot cone, the heat radiation area to the air flowing on the back side of the pilot cone becomes larger than before due to the unevenness of the fins, and the wall surface of the pilot cone becomes positive. Is cooled down. Further, the air whose wall has been cooled flows out to the pilot cone outlet as in the conventional case, and serves to prevent flame holding at the end.

[0030]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a sectional view showing a cooling structure of a pilot cone of a gas turbine combustor according to a first embodiment of the present invention, and shows an upper half of the pilot cone, which is described in the conventional example of FIG. 15 (b). , (C) as a pilot cone wall. In the figure, reference numeral 30 denotes a wall of the pilot cone to which the cooling structure of the present invention is applied, 131 denotes a guide ring which is the same as the conventional one,
I support. Reference numeral 300 denotes a cooling air described later, which has a structure in which the back surface of the wall 30 of the pilot cone flows in the pilot combustion gas flow direction G and flows into the inside of the wall as indicated by 301 to cool the wall.

FIG. 2 shows the pilot cone wall 3 shown in FIG.
0 is a plan view seen from the back side of the cone, FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, (a) is a cross-sectional shape of the internal groove is constant, (b), ( c) shows a modification in which the cross-sectional shape of the internal groove is changed.

In FIG. 2, reference numeral 1 denotes an outer plate, which constitutes the outer surface of the wall 30 of the pilot cone. Reference numeral 2 denotes a groove provided inside the outer plate 1, and its cross-sectional shape changes in a tapered shape. The tapered shape is a straight line or a smooth curve. An air suction hole 3 is formed in the outer plate 1 and communicates with a groove 2 provided inside. Reference numeral 4 denotes an inner plate, through which an air discharge hole 5 is formed, and which is in contact with and joined to the lower surface of the outer plate 1. The material of the outer plate 1 and the inner plate 4 is made of a heat-resistant material such as Hastelloy X, Tomiloy, or SUS as in the conventional case.

The air discharge hole 5 of the inner plate 4 is formed by the groove 2 of the outer plate 1.
Are arranged at a predetermined pitch along the opening of the outer plate 1 and on both sides of the air suction hole 3 of the outer plate 1 so as to communicate with the groove 2. The width of the groove 2 increases linearly from the air suction hole 3 to the air discharge hole 5, and has a minimum width at the position of the air suction hole 3 and a maximum width at the position of the air discharge hole 5. ,
The groove 2 communicates with both holes 3 and 5, respectively. Each of these grooves 2 extends from the upstream side of the pilot cone to the end on the outlet side, and is arranged at a predetermined pitch inside the peripheral wall of the pilot cone.

FIG. 3A is a sectional view taken along the line AA in FIG.
A groove 2 has a constant height h at the joint between the outer plate 1 and the inner plate 4.
Although the depth is constant, it is expanded linearly in the width direction as shown in FIG. The air suction hole 3 is formed in the outer plate 1, and the air discharge hole 5 is formed in the inner plate 4. Both holes 3 and 5 are provided so as to communicate with the groove 2. In addition, the diameter of the air discharge hole 5 is larger than the diameter of the air suction hole 3 so as to secure an outflow amount corresponding to the expanding volume of the groove 2.

FIG. 3B shows a modification of FIG.
This is an example in which the height a is linearly narrowed from the air suction hole 3 to the air discharge hole 5 and is tapered in the width direction as shown in FIG. 2C, contrary to the shape of FIG. 2B, the height of the groove 2b is changed to be narrow and tapered in the air suction hole 3 to be enlarged and widened in the air discharge hole 5, and as shown in FIG. This is an example in which the tapered shape is also expanded in the width direction. The change in the tapered depth direction may be a straight line or a smooth curve.

The examples (b) and (c) are examples in which the shape of the groove 2 is changed three-dimensionally. The taper shape is appropriately set, and the flow velocity of the cooling air flowing in the groove 2 is changed. The pressure loss can be adjusted depending on the location, and the flow velocity and the pressure loss can be set and designed to have appropriate values depending on the temperature distribution and the thermal stress distribution of the pilot cone. Processing of these grooves 2, 2a and 2b is performed by electric discharge machining or electrolytic machining because it is difficult to perform milling.

As shown in FIGS. 2 and 3, the cooling air 300 flows into the groove 2, 2a or 2b from a number of air suction holes 3 around the back side of the pilot cone, and flows on both sides to cool the wall. The air flows out from the air discharge holes 5 arranged at equal intervals into the pilot cone as indicated by 301a. The temperature of the air flowing into the air suction hole 3 is 350 ° C.
The temperature is 400 ° C., which is heated in the process of cooling the wall surface, rises to about 600 ° C., and flows into the pilot cone.

The air sucked from the air suction hole 3 is heated and expanded in the process of flowing in the grooves 2, 2a, 2b, and its volume increases. Although the flow velocity increases in the hole and the pressure loss of the air increases, the cross-sectional shape of the groove 2 expands two-dimensionally or three-dimensionally as approaching the air discharge hole 5 as in the first embodiment. Therefore, speed can be suppressed and pressure loss can be reduced.

FIG. 4 shows a cooling structure for a pilot cone of a gas turbine combustor according to a second embodiment of the present invention. A pilot cone 30 having a double structure as in FIG. That is, (a) is an example in which a turbulator is provided in the groove, and (b) is an example in which a recess is provided. In both figures, reference numerals 1 to 5 are the same as those of the first embodiment shown in FIGS. 2 and 3. In the second embodiment, in FIG. Turbulator 6 of shape
And a large number are arranged so as to be orthogonal to the flow direction, and the heat transfer coefficient is improved by stirring the flow of the cooling air. Further, FIG. 4B shows a configuration in which a large number of concave recesses 7 are provided in place of the turbulator 6, and has the effect of agitating the flow of cooling air and improving the heat transfer coefficient as in FIG. The turbulator 6 and the recess 7 may be the entire length of the groove 2 or may be partially provided in a predetermined section as required.

FIG. 5 shows the cross-sectional shape of the groove in FIG.
FIG. 5A is a sectional view taken along line BB in FIG.
FIG. 5B is a cross-sectional view taken along the line CC in FIG. FIG.
As shown in FIG. 4A, a convex turbulator 6 is formed around the groove 2, and in FIG. 4B, a recess 7 is provided on the entire wall surface of the groove 2. By providing the recesses 6 and the recesses 7 at right angles to the flow direction, the flow of the cooling air becomes turbulent and the heat transfer coefficient is improved.

In the first embodiment shown in FIGS. 2 and 3, the cross-sectional shape of the groove 2 gradually increases from the air suction hole 3 to the air discharge hole 5, thereby suppressing an increase in flow velocity due to thermal expansion of the cooling air. Although the pressure loss is reduced, the cooling performance is reduced near the air discharge hole 5. In the second embodiment, by providing the turbulator 6 and the recess 7, the heat transfer coefficient can be improved, and the decrease in the cooling performance can be compensated for.

FIG. 6 is a plan view showing a part of a wall of a cooling structure of a gas turbine combustor pilot cone according to a third embodiment of the present invention. In the figure, the wall is also a double wall 30, and the outer plate 1 is provided with an air suction hole 3. The inside of the groove 12 is processed,
Is an orifice 12a having a fixed cross-sectional shape, and the orifice 12a having a reduced width by a predetermined length is provided on both front and rear portions of the air suction hole 3.
And An air discharge hole 5 is formed in the inner plate 4.

In the third embodiment having such a structure, the cooling air passes through the air suction hole 3 from around the rear side of the pilot cone, flows into the groove 12a, and is divided into two sides.
2 and flows toward the air discharge hole 5, respectively, and is heated and expanded while cooling the wall. However, the width of the groove 12 increases near the air discharge hole 5 and the cross-sectional area increases, so that the flow velocity increases. , Pressure rise is prevented, and the same effect as in the first embodiment can be obtained.

In the third embodiment shown in FIG. 6, the cross-sectional shape of the groove 12 has been described as being constant. However, the depth direction of the groove 12 is gradually expanded toward the air discharge hole 5 to form a two-dimensional structure. If a turbulator or a recess is provided in the groove 12, the heat transfer coefficient can be further improved, and the cooling performance can be improved.

FIG. 7 is a sectional view of a wall of a cooling structure for a pilot cone of a gas turbine combustor according to a fourth embodiment of the present invention. The wall is also a double-structured wall 30, and FIG. An example in which the holes are provided obliquely, and FIG. 7B shows an example in which a cover is provided at the outlet of the air discharge hole. In FIG. 7A, FIGS.
The difference from the first and second embodiments shown in FIG. 6 and the third embodiment shown in FIG. 6 is the structure in which the air discharge holes are air discharge holes 15 inclined in the direction of the combustion gas flow direction G. Are the same as those in FIGS. 2, 3, and 6.

With such a structure, the cooling air 300 flows into the groove 2 or 12 from the air suction hole 3 from around the back side of the pilot cone, cools the wall, and obliquely extends from the air discharge hole 15 to the pilot cone 301b as indicated by 301b. However, since it flows out in the combustion gas flow direction G along the inner plate 4, it flows out while cooling the wall surface near the air discharge hole 15 to increase the cooling effect.

FIG. 7 (b) shows an air discharge hole 5 as shown in FIG. 2, FIG. 3, and FIG. 8 is provided. Other structures are the same as those shown in FIGS. Also in such a structure, the air flowing out of the air discharge hole 5 into the transition piece flows out in the combustion gas flow direction G along the inner plate 4, so that the same effect as that of FIG. Increase.

FIG. 8 is a plan view showing a part of a wall of a cooling structure of a gas turbine combustor according to a fifth embodiment of the present invention, and FIG. 9 is a perspective view thereof. In both figures, the wall is a double-structured wall 30, and an air suction hole 3 is drilled in the outer plate 1,
A groove 9 is machined therein. An air discharge hole 5 or 15 is formed in the inner plate 4. As shown in the figure, the groove 9 is provided in a wave shape meandering in an S-shape, and the air suction hole 3 communicates with the air discharge hole 5 or 15, and the air discharge hole 5 is provided on both sides of the air suction hole 3. Or 15 are arranged at equal intervals.

In the fifth embodiment having the above-described structure, cooling air flows into the groove 9 through the air suction hole from around the rear side of the pilot cone, and flows in a meandering S-shape to cool the wall. The air flows out from the air discharge hole 5 or 15 into the pilot cone as indicated by 301c, but since the groove 9 has a waveform, the flow path length becomes longer than that of the linear groove, particularly in a short section, and the cooling flow path The length can be lengthened. As a result, it is possible to design to obtain the required cooling effect with the minimum cooling air, adjust the flow rate of the cooling air, the pressure loss, the heat transfer coefficient according to the temperature distribution and the cooling flow path length, and reduce the thermal stress. This can be reduced to prevent cracks and the like and improve reliability.

The turbulator 6 and the recess 7 shown in FIG. 4 can be provided in the groove 9 shown in FIGS.
The orifice shown in FIG. 6 can be provided in a predetermined section on both sides of the air suction port, or a two-dimensional or three-dimensional cross-sectional change as shown in FIG. 2 can be provided as necessary.

FIG. 10 is a plan view showing a part of a wall of a cooling structure of a pilot cone of a gas turbine combustor according to a sixth embodiment of the present invention. ) Shows an example of a linear groove, and (b) shows an example of a corrugated groove. FIG. 10 (a) shows the structure shown in FIG. 2 in which the air suction holes 3 and the air discharge holes 5 are arranged between the grooves 2 adjacent to each other, and the flow direction of the cooling air 300 flowing in the grooves 2 is reversed. In this case, the grooves 2 are reversed in adjacent grooves 2.

Also, in FIG.
And the air discharge holes 5 are arranged between the adjacent grooves 9 so that the cooling air flows in the adjacent grooves 9 are opposite to each other. Although not shown, cooling air can be similarly supplied to the structure shown in FIG. The turbulator 6 and the recess 7 shown in FIG.
The air discharge hole may be an air discharge hole 15 or a cover 8 as shown in FIG.

In the sixth embodiment having the above-described structure, the cooling air 300 flows in opposite directions in the grooves adjacent to each other inside the wall, so that uniform cooling can be performed on the entire wall, and the temperature distribution due to the cooling of the pilot cone can be reduced. Uniformity is eliminated, and the imbalance in generation of thermal stress is eliminated.

FIG. 11 is a plan view showing a part of a wall of a cooling structure of a gas turbine combustor according to a seventh embodiment of the present invention. FIG. 11 (a) shows an example in which an air discharge hole is formed at a connection portion of the wall. ,
(B) is an example in which an air suction hole is formed at a connection portion of a wall.
The cooling structure of these connecting portions can be applied to all of the welded portions of the walls in the cooling structures of the first to sixth embodiments described above. It is applied when forming a cone.

In FIG. 11A, reference numeral 20 denotes a connecting portion, which serves as a connecting portion of a wall constituting the pilot cone, and is connected by welding to form a pilot cone. A groove 2 is formed in the outer plate 1, and air suction holes 3 are provided at a predetermined pitch along the groove 2, and air discharge holes 5 are provided on both sides of the air suction hole 3 in an inner plate 4 in contact with the outer plate 1. They are arranged at predetermined intervals. Therefore, in the connection part 20, the arrangement of these holes 3 and 5 is not always arranged at a predetermined size at the end.

According to the above situation, as shown in FIG. 11 (a), a through hole 10 communicating with the groove 2 at the end of the connecting portion 20 of the wall and penetrating the outer plate 1 and the inner plate 4 is formed. . Through hole 1
Since the cooling air flows into the pilot cone at 0, a lid 11 is inserted into the through hole 10 from the outside of the outer plate 1 to allow this air to flow out into the pilot cone, and the outside is closed to prevent the air from flowing. At the end and air at the end into the pilot cone.

FIG. 12A is a diagram showing the D- in FIG.
D shows a part of the cross-sectional view, in which a through hole 10 is projected from the outer plate 1 and the inner plate 4, and a lid 11 is inserted into the outer plate 1 of the through hole 10 and flows through the groove 2. The cooling air flows out as 301d into the inner plate 4 side, that is, into the pilot cone.

In FIG. 11 (b), a through hole 10 is similarly provided at the end of the connecting portion 20. These through holes 1
Numeral 0 communicates with the groove 2 and an air discharge hole 5 is provided upstream of the through hole 10.
It is necessary to flow so as to flow out of the pilot cone. Therefore, the lid 11 is inserted into the through hole 10 from the inner plate 4 side, and at the end, the air flows from the outer periphery of the pilot cone of the outer plate 1 into the groove 2 through the through hole 10 and the air discharge hole on the upstream side. 5 into the pilot cone.

FIG. 12B is a diagram showing E- in FIG. 11B.
FIG. 5 is a cross-sectional view taken along a line E in FIG.
The cover 11 is inserted into the through hole 10 from the inner plate 4 side, and air 300 flows into the through hole 10 from the back side of the pilot cone and flows into the groove 2.

By adopting the structure of the connecting portion of the seventh embodiment described above in the air cooling structure of the pilot cone of the gas turbine combustor, the inside of the groove at the end of the connecting portion of the wall of the pilot cone is cooled. By flowing air, the wall of the connection part 20 can be cooled uniformly.

FIGS. 13A and 13B show a cooling structure of a pilot cone of a gas turbine combustor according to an eighth embodiment of the present invention. FIG. 13A is a cross-sectional view showing the upper half of the pilot cone, and FIG. FIG. In FIG. 13A, reference numeral 31 denotes a pilot cone, the outer periphery of which is supported by a guide ring 131 as in the conventional case. On the wall of the pilot cone 31, a plurality of dimples 13 projecting conically toward the inside are arranged and formed.
The dimple 13 has air 3 in the flow direction of the combustion gas.
Hole 1 inclined from the wall of the conical part so that 01e flows out
4 is open.

FIG. 13 (b) is an enlarged cross-sectional view of this. Air 300 flows on the back side of the pilot cone 31 and flows out to the tip while cooling the wall as in the conventional case. 14 flows into the inside of the pilot cone 31, forms a film layer of cooling air on the wall surface, and performs the film cooling to enhance the wall cooling effect.

FIG. 14 shows a gas turbine combustor pilot cone according to a ninth embodiment of the present invention, in which (a) is a sectional view and (b) is a sectional view taken along line FF in (a). In both figures, 32 is a pilot cone and 131 is a guide ring, which is the same as the conventional one. In the ninth embodiment, a large number of fins 17 are arranged on the back side of the pilot cone 32 in the front-rear direction of the pilot cone 32 to protrude therefrom, and the guide ring 131 is configured to support the outer periphery of the fin 17. Things.

According to the cooling structure of the ninth embodiment having such a structure, the cooling air 300 flows through the space formed by the guide ring 131 and the many fins 17 behind the pilot cone 32 and flows out to the end. However, the heat radiation area to the air is increased due to the irregularities formed by the fins 17, and the wall is more actively cooled than before, and the air cooled on the wall is used to prevent flame holding at the pilot cone outlet. You.

[0065]

The cooling structure of the pilot cone of the gas turbine combustor according to the present invention has the following features. (1) A plurality of rows of cooling air passages are provided around the inside of the wall of the pilot cone of the gas turbine combustor in the combustion gas flow direction. In each of the passages, an air suction hole opened on the back side of the pilot cone and an air discharge hole opened on the inside of the pilot cone are sequentially arranged at predetermined intervals so as to communicate with each other. Is characterized in that the width and / or depth of the passage cross section smoothly changes in the direction of air flow. With such a configuration, the pilot cone can be effectively cooled from the inside of the wall, and the cooling effect is significantly increased as compared with the conventional system in which air is flowed to the back side. Furthermore, it is possible to adjust by changing the flow velocity, pressure loss, and heat transfer coefficient in the passage of the cooling air, thereby enabling the design of the cooling passage under optimum conditions and improving the temperature distribution that differs depending on the location of the wall surface. To reduce thermal stress,
Damage such as wall cracks can be prevented, and reliability can be significantly improved. In (2) and (3), the action of the turbulator and the recess can stir the flow of the cooling air to further improve the heat transfer coefficient.

In (4) of the present invention, a plurality of rows of cooling air passages are provided around the inside of the wall of the pilot cone of the gas turbine combustor in the direction of flow of the combustion gas, and each of the passages is opened on the back side of the pilot cone. The air suction holes and the air discharge holes opening inside the pilot cone are sequentially arranged at predetermined intervals so as to communicate with each other, and the section of the passage between the air suction hole and the air discharge hole is the same as the section having a constant cross-sectional shape. The flow path is narrower than the cross-sectional area of the section, and alternately communicates with the section whose shape does not change. With such a structure, the same effect as the above (1) can be obtained, and the flow path of the passage can be restricted by the orifice effect, or the flow velocity can be adjusted by expanding the flow path.

In (5) of the present invention, a plurality of cooling air passages are provided around the inside of the wall of the pilot cone of the gas turbine combustor in the combustion gas flow direction, and each of the passages is opened to the back side of the pilot cone. An air suction hole and an air discharge hole opening inside the pilot cone are sequentially arranged at predetermined intervals to communicate with each other, and the passage is meandering in a wave shape. With such a structure, it is possible to increase the flow path length by making the passage meander in a waveform, and this is particularly effective when it is desired to enhance the cooling effect depending on the location of the pilot cone, and the cooling effect can be enhanced.

In the method (6), when air is discharged from the air discharge hole, the air is discharged in the combustion gas flow direction along the wall surface, and is discharged into the combustor while effectively cooling the vicinity of the discharge hole. Can be. In (7), the same effect as (6) can be realized by providing a cover. In (8), since the air flows in the adjacent passages are in opposite directions, the cooling imbalance is eliminated. In addition, the wall of the combustor is formed by connection by welding, and at this connection portion, the passage ends at an intermediate point, and there may be a portion where cooling air does not flow and stays.
In (9), in this case, by providing a through hole at the end of the passage and closing the outside or inside with a lid, air can be sucked in from the outside or discharged into the combustor. Effective cooling is also possible in the part.

According to (10) of the present invention, a plurality of dimples protruding in a conical shape from the back side to the inside are arranged and provided on the wall of the pilot cone of the gas turbine combustor. It is characterized in that a hole is provided in which cooling air is jetted inward from the back side in the direction in which the combustion gas flows. With such a structure, the cooling air flows out along the inner wall surface of the pilot cone from the hole of the dimple, and the wall surface is film-cooled, so that the cooling effect of the wall surface is significantly improved as compared with the conventional case.

According to (11) of the present invention, in a gas turbine combustor pilot cone whose periphery is supported by a guide ring, a plurality of projecting protrusions are provided between the guide ring and the pilot cone on the outer periphery on the back side of the pilot cone. The fin is formed in the front-back direction. Due to such a structure, the heat transfer area to the air flowing on the back side of the pilot cone becomes larger than before due to the unevenness of the fins, cooling performance is improved, and the air cooled on the wall is the same as the conventional one at the pilot cone outlet end face Also has the effect of preventing flame holding in

[Brief description of the drawings]

FIG. 1 is a sectional view of a pilot cone to which a gas turbine combustor pilot cone cooling structure according to a first embodiment of the present invention is applied.

FIG. 2 is a plan view of a wall of the pilot cone in FIG. 1;

3A is a cross-sectional view taken along the line AA in FIG. 2, wherein FIG. 3A shows a constant depth of the groove cross section, FIG. 3B shows a depth decreasing toward the air discharge hole, and FIG. The example which expanded toward the hole is shown, respectively.

FIG. 4 is a plan view showing a part of a wall of a cooling structure of a pilot cone of a gas turbine combustor according to a second embodiment of the present invention, where (a) shows an example in which a turbulator is provided in a groove,
(B) is an example in which a recess is provided.

5A and 5B show a cross-sectional shape of the groove in FIG. 4; FIG. 5A is a cross-sectional view taken along line BB in FIG. 4A; FIG. 5B is a cross-sectional view taken along line CC in FIG.

FIG. 6 is a plan view showing a part of a wall of a cooling structure of a gas turbine combustor pilot cone according to a third embodiment of the present invention.

FIG. 7 shows a groove cross-sectional view of a cooling structure of a gas turbine combustor pilot cone according to a fourth embodiment of the present invention,
(A) is an example in which an air discharge hole is provided diagonally, and (b) is an example in which a cover is provided at an air discharge hole outlet.

FIG. 8 is a plan view showing a part of a wall of a cooling structure of a gas turbine combustor pilot cone according to a fifth embodiment of the present invention.

FIG. 9 is a perspective view of the cooling structure shown in FIG.

FIG. 10 is a plan view showing a part of a wall of a cooling structure of a pilot cone of a gas turbine combustor according to a sixth embodiment of the present invention, where (a) is a straight groove, and (b) is a wavy shape. Each groove is shown.

FIG. 11 is a plan view showing a part of a wall connection part of a cooling structure of a pilot cone of a gas turbine combustor according to a seventh embodiment of the present invention. )
Indicates an example in which an air suction hole is provided.

FIG. 12 is a cross-sectional view of FIG.
1 (a) is a cross-sectional view taken along line D-D, and FIG.
It is EE sectional drawing in.

13A and 13B show a cooling structure of a pilot cone of a gas turbine combustor according to an eighth embodiment of the present invention, wherein FIG. 13A is a sectional view of the pilot cone, and FIG. 13B is an enlarged sectional view of a wall.

14A and 14B show a cooling structure of a pilot cone of a gas turbine combustor according to a ninth embodiment of the present invention, wherein FIG. 14A is a cross-sectional view of the pilot cone, and FIG.
It is an arrow F view.

FIGS. 15A and 15B are general configuration diagrams of a gas turbine combustor, in which FIGS. 15A and 15B show examples using an air cooling system, and FIG. 15C shows an example using a steam cooling system.

FIG. 16 is a perspective view of a wall structure of a conventional air-cooled gas turbine combustor.

FIG. 17 is a side view of a pilot cone of a conventional gas turbine combustor.

[Explanation of symbols]

 Reference Signs List 1 outer plate 2, 2a, 2b, 9, 12 groove 3 air suction hole 4 inner plate 5, 15 air discharge hole 6 turbulator 7 dent 8 cover 10 through hole 11 lid 12a orifice 13 dimple 14 hole 17 fin 30, 31, 32 Pilot cone

Claims (11)

[Claims] 1. A plurality of rows of cooling air passages are provided around the inside of a wall of a pilot cone of a gas turbine combustor in the direction of flow of combustion gas. The air discharge holes opened inside the cone are sequentially arranged at predetermined intervals to communicate with each other, and the section between the air suction hole and the air discharge hole in each of the passages has a width or depth of the passage cross section, or both. A cooling structure for a pilot cone of a gas turbine combustor, wherein the cooling structure smoothly changes in a direction of air flow. 2. A cooling structure for a pilot cone of a gas turbine combustor according to claim 1, wherein a plurality of turbulators are provided in a predetermined section of said passage so as to be substantially perpendicular to a flow direction of air. 3. The pilot cone of a gas turbine combustor according to claim 1, wherein a plurality of concave grooves are provided on a wall surface of a predetermined section of the passage so as to be substantially orthogonal to a flow direction of air. Cooling structure. 4. A plurality of rows of cooling air passages are provided around the inside of the wall of the pilot cone of the gas turbine combustor in the flow direction of the combustion gas, and each of the passages has an air suction hole opened on the back side of the pilot cone and the pilot air passage. The air discharge holes that open inside the cone are sequentially arranged at predetermined intervals so as to communicate with each other, and the section between the air suction hole and the air discharge hole of the passage is smaller than the cross-sectional area of the same section as the section where the cross-sectional shape remains unchanged. A cooling structure for a pilot cone of a gas turbine combustor, wherein a passage having a narrow flow path and a shape-invariable section are alternately communicated with each other. 5. A plurality of rows of cooling air passages are provided around the inside of a wall of a pilot cone of a gas turbine combustor in the direction of flow of combustion gas, and each of the passages has an air suction hole opened on the back side of the pilot cone and the pilot passage. A cooling structure for a pilot cone of a gas turbine combustor, wherein air discharge holes that are opened inside the cone are sequentially arranged at predetermined intervals to communicate with each other, and the passage is meandering in a wave shape. 6. The air discharge hole according to claim 1, wherein the air discharge hole is provided so as to be inclined so that air flows out toward the inside of the pilot cone in the flow direction of the pilot combustion gas. A cooling structure for a pilot cone of a gas turbine combustor according to any of the first to third aspects. 7. A cover is provided around the outlet of the air discharge hole so that air flows out in the flow direction of the pilot combustion gas.
6. The cooling structure for a pilot cone of a gas turbine combustor according to any one of 5. 8. The arrangement of the air suction holes and the air discharge holes in each of the passages is configured such that the flow direction of the air flowing through the passages is opposite to the flow direction of the air in the adjacent passages. The cooling structure for a pilot cone of a gas turbine combustor according to any one of claims 1, 4, and 5, wherein 9. A terminal portion of each of the passages at the wall connecting portion communicates with a corresponding one of holes extending from the back side of the pilot cone wall to the inside thereof, corresponding to the terminal portions. The cooling structure for a pilot cone of a gas turbine combustor according to any one of claims 1, 4, and 5, wherein a lid is inserted and closed from any one of the insides. 10. A plurality of dimples protruding in a conical shape from the back side to the inside in an array on a wall of a pilot cone of a gas turbine combustor, and the dimple has a conical portion in a direction in which pilot combustion gas flows. A cooling structure for a pilot cone of a gas turbine combustor, characterized in that a hole for injecting cooling air is provided from the back side toward the inside. 11. A gas turbine combustor pilot cone whose periphery is supported by a guide ring, wherein a plurality of projecting fins are formed in the front-rear direction around the back side of the pilot cone between the guide ring and the pilot cone. A cooling structure for a pilot cone of a gas turbine combustor, which is characterized in that: