Patent Application
20240077026
The present invention relates to a combustor cylinder that defines a flow path through which a combustion gas flows, a combustor including the combustor cylinder, and a gas turbine including the combustor.
Priority is claimed on Japanese Patent Application No. 2021-028331, filed on Feb. 25, 2021, the content of which is incorporated herein by reference.
A combustor of a gas turbine includes a combustor cylinder that defines a flow path of a combustion gas, and a combustor body that injects a fuel together with air into the combustor cylinder. Inside the combustor cylinder, the fuel is subjected to combustion, and the combustion gas generated through the combustion of the fuel flows.
As the combustor cylinder, for example, there is a combustor cylinder disclosed in PTL 1 below. The combustor cylinder includes a barrel having a cylindrical shape around an axis, and an air supply pipe attached to the barrel. The cylindrical barrel has an opening that penetrates an inner peripheral surface thereof from an outer peripheral surface thereof, and a plurality of cooling flow paths through which a cooling medium flows. In the plurality of cooling flow paths, outlets of some cooling flow paths are formed in an edge of the opening. The air supply pipe functions to supply secondary air for combustion to an inner peripheral side of the barrel. The air supply pipe has a cylindrical pipe body and a lip portion provided in the pipe body. A part of the pipe body is inserted into the inner peripheral side of the barrel from the opening, and protrudes to the inner peripheral side of the barrel. The above-described lip portion is provided in, of both ends of the pipe body, an end of the inner peripheral side of the barrel.
A high-temperature combustion gas flows on the inner peripheral side of the barrel in the combustor cylinder disclosed in PTL 1 above. Some of the combustion gas collides with a portion of the air supply pipe which is located on the inner peripheral side of the barrel. When the combustion gas collides with the air supply pipe, while a dynamic pressure thereof is lowered, a static pressure thereof rises. As a result, in the combustor cylinder disclosed in PTL 1 above, some of the combustion gas may flow back into the cooling flow path in which the outlet is formed in the edge of the opening of the barrel, thereby possibly causing the barrel to be burnt.
Therefore, an object of the present disclosure is to provide a technique for improving durability of a combustor cylinder.
As one aspect according to the present disclosure for achieving the above-described object, there is provided a combustor cylinder including a barrel that forms a cylindrical shape around a cylinder axis and that defines a circumference of a combustion space through which a combustion gas flows in a direction having a direction component, of an upstream side and a downstream side in a cylinder axis direction in which the cylinder axis extends, from the upstream side to the downstream side, and an air supply pipe attached to the barrel. The cylindrical barrel has an inner peripheral surface facing the combustion gas, an outer peripheral surface facing a side opposite to the inner peripheral surface, an insertion opening that penetrates the inner peripheral surface from the outer peripheral surface, and a plurality of cooling flow paths extending between the inner peripheral surface and the outer peripheral surface in a direction along the inner peripheral surface and through an inside of which a cooling medium flows. A part of the air supply pipe is inserted into an inner peripheral side of the barrel from the insertion opening, and protrudes to the inner peripheral side of the barrel. Each of the plurality of cooling flow paths has an inlet configured to introduce the cooling medium into the cooling flow path, and an outlet configured to discharge the cooling medium flowing into the cooling flow path. The plurality of cooling flow paths have a plurality of opening circumference flow paths, as some cooling flow paths in the plurality of cooling flow paths. The plurality of opening circumference flow paths have a circumvention flow path portion extending along an edge of the insertion opening. In the plurality of opening circumference flow paths, at least one opening circumference flow path forms an impingement flow path. The impingement flow path has an impingement circumvention flow path portion, as the circumvention flow path portion. The impingement circumvention flow path portion intersects with a collision gas axis extending in a flowing direction of, of the combustion gas, the combustion gas directed toward a pipe center axis, which is a radial direction of the air supply pipe with respect to the pipe center axis, extends in a direction having a direction component of the upstream side along the edge of the insertion opening from the collision gas axis, and extends in a direction having a direction component of the downstream side along the edge of the insertion opening from the collision gas axis. In the impingement circumvention flow path portion, an intersection position intersecting with the collision gas axis is located on the upstream side of the pipe center axis. In the impingement circumvention flow path portion, the outlet which opens on the inner peripheral surface is not formed in a portion within a range of a predetermined angle around the collision gas axis which is an angle around the pipe center axis.
When the combustion gas flowing inside the barrel collides with the air supply pipe, whereas a dynamic pressure thereof is lowered, a static pressure thereof rises. A static pressure rise region in which the combustion gas collides with the air supply pipe and the static pressure of the combustion gas rises is within a range of a predetermined upstream-side angle from the collision gas axis to the upstream side, which is an angle around the pipe center axis, and is within a range of a predetermined downstream-side angle from the collision gas axis to the downstream side. In the present aspect, the plurality of opening circumference flow paths having the circumvention flow path portion extending along the edge of the insertion opening are provided. Therefore, the edge of the insertion opening can be cooled by the cooling medium flowing through the circumvention flow path portion. Moreover, in the present aspect, the outlet of the impingement flow path having the impingement circumvention flow path portion is not formed in a portion inside the static pressure rise region in the impingement circumvention flow path portion. Therefore, in the present aspect, even when the combustion gas inside the barrel collides with the air supply pipe and the static pressure of the combustion gas rises inside the static pressure rise region, it is possible to prevent a backflow of the combustion gas into the impingement flow path.
As one aspect according to the present disclosure for achieving the above-described object, there is provided a combustor including the combustor cylinder according to the one aspect, and a burner disposed on an upstream side of the insertion opening and configured to inject a fuel into the combustion space. The burner has a burner frame having an annular fuel injection port around the cylinder axis, and a swirler provided inside the burner frame and configured to swirl the fuel ejected from the fuel injection port around the cylinder axis. The swirler is configured so that an angle of the fuel ejected from the fuel injection port with respect to the cylinder axis becomes a predetermined fuel swirl angle. An angle of the collision gas axis with respect to the cylinder axis is within a range of the fuel swirl angle ±15°.
When the fuel is swirled around the cylinder axis inside the combustion space on the inner peripheral side of the barrel, the collision axis angle, which is the angle of the collision gas axis with respect to the cylinder axis, substantially becomes the fuel swirl angle. However, the collision axis angle slightly varies depending on a relationship between a ratio of an injection flow rate of the fuel to an injection flow rate of the combustion air and a swirl angle of the combustion air. Therefore, the collision axis angle does not need to completely coincide with the fuel swirl angle, and may be any angle within an angle range of the fuel swirl angle ±15°.
As one aspect according to the present disclosure for achieving the above-described object, there is provided a gas turbine including the combustor according to the one aspect, a compressor configured to feed compressed air to the combustor, and a turbine configured to be driven by the combustion gas from the combustor.
In one aspect according to the present disclosure, it is possible to improve durability of a combustor cylinder.
Hereinafter, an embodiment of a combustor cylinder, a combustor, and a gas turbine according to the present disclosure, as well as various modification examples of the combustor cylinder will be described in detail with reference to the drawings.
A gas turbine of the present embodiment will be described with reference to
The gas turbine of the present embodiment includes a compressor 1 that compresses outside air Ao to generate compressed air A, a plurality of combustors 4 that combust a fuel F in the compressed air A to generate a combustion gas G, and a turbine 5 driven by the combustion gas G.
The compressor 1 includes a compressor rotor 2 that rotates around a rotational axis Ar, and a compressor casing 3 that covers the compressor rotor 2 to be rotatable. The turbine 5 has a turbine rotor 6 that rotates around the rotational axis Ar, and a turbine casing 7 that covers the turbine rotor 6 to be rotatable.
The compressor 1 is disposed on an upstream side with respect to the turbine 5, between the upstream side and a downstream side in a rotational axis direction in which the rotational axis Ar extends. The compressor rotor 2 and the turbine rotor 6 are located on the same rotational axis Ar, and are connected to each other to form a gas turbine rotor 8. For example, a rotor of a generator GEN is coupled to the gas turbine rotor 8.
The gas turbine further includes an intermediate casing 9. The compressor casing 3, the intermediate casing 9, and the turbine casing 7 are arranged in this order in the above-described rotational axis direction, and are connected to each other. The plurality of combustors 4 are provided in the intermediate casing 9.
The compressor 1 compresses the outside air Ao to generate the compressed air A. The compressed air A flows into the combustor 4. In addition, the fuel F is supplied to the combustor 4. Inside the combustor 4, the fuel F is combusted to generate the combustion gas G. The combustion gas G is fed into the turbine 5 to rotate the turbine rotor 6. The rotor of the generator GEN connected to the gas turbine rotor 8 is rotated by rotation of the turbine rotor 6. As a result, the generator GEN generates electricity. The fuel F in the present embodiment mainly includes a blast furnace gas from a blast furnace of a steel mill (hereinafter, referred to as a blast furnace gas (BFG)), and in some cases, a coke oven gas (COG) may be included in the BFG.
A combustor cylinder and the combustor 4 including the same of the present embodiment will be described with reference to
The combustor 4 of the present embodiment includes a combustion cylinder 20 serving as a combustor cylinder that defines a combustion space S through which the combustion gas G flows, and a combustor body 10 that injects the fuel F together with the compressed air A into the combustion cylinder 20. The combustion cylinder 20 is disposed inside the intermediate casing 9 in which the compressed air A compressed by the compressor 1 floats (refer to
As illustrated in
The outer cylinder 11 has an outer cylinder barrel 11a forming a cylindrical shape around the cylinder axis Ac, and a lid 11b that closes an opening on the upstream side Dau of the outer cylinder barrel 11a. An end of the outer cylinder barrel 11a on the downstream side Dad is connected to the intermediate casing 9 described above with reference to
The support cylinder 12 forms a cylindrical shape around the cylinder axis Ac, and is disposed on an inner peripheral side of the outer cylinder 11. The support cylinder 12 has an air introduction opening 12a penetrating the inner peripheral side from an outer peripheral side. An end of the support cylinder 12 on the upstream side Dau is connected to the lid 11b of the outer cylinder 11. The compressed air A floating inside the intermediate casing (refer to
The inner cylinder 13 has a small-diameter barrel 13a, an increasing diameter barrel 13b, and a large-diameter barrel 13c. All of the small-diameter barrel 13a, the increasing diameter barrel 13b, and the large-diameter barrel 13c form a cylindrical shape around the cylinder axis Ac. The small-diameter barrel 13a is disposed on the inner peripheral side of the support cylinder 12. An end of the increasing diameter barrel 13b on the upstream side Dau is connected to an end of the small-diameter barrel 13a on the downstream side Dad. An inner diameter of the increasing diameter barrel 13b gradually increases toward the downstream side Dad. The inner diameter of the end of the increasing diameter barrel 13b on the downstream side Dad is substantially the same as the inner diameter of the support cylinder 12. An end of the large-diameter barrel 13c on the upstream side Dau is connected to an end of the increasing diameter barrel 13b on the downstream side Dad and to an end of the support cylinder 12 on the downstream side Dad. Accordingly, the inner cylinder 13 is supported by the support cylinder 12. A space on the inner peripheral side of the increasing diameter barrel 13b and a space on the inner peripheral side of the large-diameter barrel 13c form a portion of the combustion space S on the upstream side Dau.
The burner 14 has a burner frame 15 and a plurality of fuel swirlers 16 that swirl the gas fuel F around the cylinder axis Ac. The burner frame 15 has a burner cylinder 15a forming a cylindrical shape around the cylinder axis Ac, and a center cylinder 15b disposed inside the burner cylinder 15a. The burner cylinder 15a is disposed on the inner peripheral side of the small-diameter barrel 13a of the inner cylinder 13. A portion of the burner cylinder 15a on the upstream side Dau penetrates the lid 11b portion of the outer cylinder 11. The burner cylinder 15a is fixed to the lid 11b portion of the outer cylinder 11. Both the end of the upstream side Dau and the end of the downstream side Dad of the burner cylinder 15a are open. The fuel F flows into the burner cylinder 15a from an opening in the end of the burner cylinder 15a on the upstream side Dau. The center cylinder 15b forms a cylindrical shape around the cylinder axis Ac, and is disposed so that its own center axis is located on the cylinder axis Ac. An annular space between the inner peripheral side of the burner cylinder 15a and the outer peripheral side of the center cylinder 15b forms a fuel flow path through which the fuel F flows. Therefore, an annular fuel injection port 14j is formed around the cylinder axis Ac in an end edge of the burner cylinder 15a on the downstream side Dad and in an end edge on the outer peripheral side of the center cylinder 15b on the downstream side Dad. The plurality of fuel swirlers 16 are disposed inside the fuel flow path. In the fuel swirler 16, a radial outer end with respect to the cylinder axis Ac is connected to an inner peripheral surface of the burner cylinder 15a, and a radial inner end with respect to the cylinder axis Ac is connected to an outer peripheral surface of the center cylinder 15b. The center cylinder 15b is fixed to the burner cylinder 15a via the plurality of fuel swirlers 16. The plurality of fuel swirlers 16 are configured so that an angle of the fuel F ejected from the fuel injection port 14j into the combustion space S with respect to the cylinder axis Ac becomes a predetermined fuel swirl angle θf. Specifically, an angle of a portion on the downstream side Dad in the fuel swirler 16 with respect to the cylinder axis Ac is the above-described fuel swirl angle θf. For example, the fuel swirl angle θf is 40°.
The air injector 17 has an air injection frame 18 and a plurality of air swirlers 19 that swirl the compressed air A around the cylinder axis Ac. The air injection frame 18 is formed by the small-diameter barrel 13a of the inner cylinder 13 and the burner cylinder 15a. An annular space between the outer peripheral side of the burner cylinder 15a and the inner peripheral side of the small-diameter barrel 13a forms an air flow path through which the compressed air A flows. The compressed air A flowing into the inner peripheral side of the support cylinder 12 from the air introduction opening 12a of the support cylinder 12 flows into the air flow path from a gap between the outer peripheral side of the burner cylinder 15a and an end edge of the small-diameter barrel 13a on the upstream side Dau. The compressed air A flows inside the air flow path, and is ejected from an air injection port 17j into the combustion space S as primary combustion air A1. The air injection port 17j has an annular shape around the cylinder axis Ac, and is formed by the end edge of the burner cylinder 15a on the downstream side Dad and by an end edge of the small-diameter barrel 13a on the downstream side Dad. The plurality of air swirlers 19 are disposed inside the air flow path. In the air swirler 19, a radial outer end with respect to the cylinder axis Ac is connected to the inner peripheral surface of the small-diameter barrel 13a, and a radial inner end with respect to the cylinder axis Ac is connected to the outer peripheral surface of the burner cylinder 15a. The plurality of air swirlers 19 are configured so that an angle of the compressed air A (primary combustion air A1) ejected from the air injection port 17j into the combustion space S with respect to the cylinder axis Ac becomes a predetermined air swirl angle. Specifically, an angle of a portion on the downstream side Dad in the air swirler 19 with respect to the cylinder axis Ac is the above-described air swirl angle. For example, the air swirl angle is 35°.
The combustion cylinder 20 serving as the combustor cylinder has a barrel 21 forming a cylindrical shape around the cylinder axis Ac, and an air supply pipe 40 attached to the barrel 21. The air supply pipe 40 may be referred to as a scoop. The cylindrical barrel 21 defines a circumference of the combustion space S through which the combustion gas G flows. An end of the barrel 21 on the upstream side Dau is connected to an end of the inner cylinder 13 on the downstream side Dad. In addition, as illustrated in
The barrel 21 has an inner peripheral surface 23i facing the combustion gas G, an outer peripheral surface 22o facing a side opposite to the inner peripheral surface 23i, a circular insertion opening 25 penetrating the inner peripheral surface 23i from the outer peripheral surface 22o, and a plurality of cooling flow paths 30 through which a cooling medium flows between the inner peripheral surface 23i and the outer peripheral surface 22o. The cooling medium herein is the compressed air A floating inside the intermediate casing (refer to
As illustrated in
As illustrated in
As illustrated in
Each of the plurality of opening circumference flow paths 33 has a circumvention flow path portion 34 extending along an edge of the insertion opening 25, an upstream-side flow path portion 35 extending from an end of the circumvention flow path portion 34 on the upstream side Dau to the upstream side Dau in the cylinder axis direction Da, and a downstream-side flow path portion 36 extending from an end of the circumvention flow path portion 34 on the downstream side Dad to the downstream side Dad in the cylinder axis direction Da. Both the upstream-side flow path portion 35 and the downstream-side flow path portion 36 are linear flow path portions extending in the cylinder axis direction Da. On the other hand, the circumvention flow path portion 34 is an arc-shaped flow path portion extending along the edge of the circular insertion opening 25. The inlet 30i of the opening circumference flow path 33 is formed in one of the upstream-side flow path portion 35 and the downstream-side flow path portion 36. The inlet 30i is shared with the inlet 30i of one normal flow path 31 of the plurality of normal flow paths 31. In addition, the outlet 30o of the opening circumference flow path 33 is formed in the other of the upstream-side flow path portion 35 and the downstream-side flow path portion 36. The outlet 30o shares the compressed air with the outlet 30o of another normal flow path 31 of the plurality of normal flow paths 31. The inlet 30i and the outlet 30o of the opening circumference flow path 33 are not formed in the circumvention flow path portion 34.
Here, a line extending in a flowing direction of, of the combustion gas G, the combustion gas G directed toward the pipe center axis At, which is the radial direction with respect to the pipe center axis At, will be referred to as a collision gas axis Ai. In the present embodiment, the flowing direction of the combustion gas G directed toward the pipe center axis At with respect to the cylinder axis Ac is approximately the same as the above-described fuel swirl angle θf, which is 40°. Therefore, a collision axis angle θi, which is an angle formed by the collision gas axis Ai of the present embodiment with respect to the cylinder axis Ac, is 40°. An intersection position of the collision gas axis Ai and the outer peripheral surface 22o of the air supply pipe 40 forms a main collision position 41p.
A part of the plurality of opening circumference flow paths 33 forms a plurality of impingement flow paths 33i, and the rest forms a plurality of non-impingement flow paths 33n. The circumvention flow path portion 34 of the impingement flow path 33i forms an impingement circumvention flow path portion 34i. Here, as illustrated in
The impingement circumvention flow path portion 34i for each of the plurality of impingement flow paths 33i intersects with the collision gas axis Ai. An intersection position 34p intersecting with the collision gas axis Ai is located on the upstream side Dau of the pipe center axis At and on the circumferential first side Dc1 of the pipe center axis At.
When the combustion gas G flowing inside the barrel 21 collides with the air supply pipe 40, whereas a dynamic pressure thereof is lowered, a static pressure thereof rises. A static pressure rise region R in which the combustion gas G collides with the air supply pipe 40 and the static pressure of the combustion gas G rises is within a range of a predetermined angle (θu+θd) around the pipe center axis At, which is an angle around the collision gas axis Ai. Specifically, the static pressure rise region R is within a range of a predetermined upstream-side angle θu from the collision gas axis Ai to the upstream side Dau, which is an angle around the pipe center axis At, and is within a range of a predetermined downstream-side angle θd from the collision gas axis Ai to the downstream side Dad. Here, the predetermined angle (θu+θd) varies depending on a flow speed immediately before the combustion gas G collides with the air supply pipe 40. Therefore, the predetermined angle (θu+θd) is 60°±20°. Specifically, the upstream-side angle θu and the downstream-side angle θd are 30°±10°. The upstream-side angle θu and the downstream-side angle θd of the present embodiment are 30°.
The impingement circumvention flow path portion 34i extends in a direction having a direction component of the upstream side Dau from the collision gas axis Ai along the edge of the insertion opening 25, and extends in a direction having a direction component of the downstream side Dad from the collision gas axis Ai along the edge of the insertion opening 25. An end of a portion extending in the direction having the direction component of the upstream side Dau from the collision gas axis Ai is connected to the upstream-side flow path portion 35 of the impingement flow path 33i. In addition, an end of a portion extending in the direction having the direction component of the downstream side Dad from the collision gas axis Ai is connected to the downstream-side flow path portion 36 of the impingement flow path 33i.
As described above, the inlet 30i and the outlet 30o are not formed in the circumvention flow path portion 34 for each of the plurality of opening circumference flow paths 33. Therefore, in the impingement circumvention flow path portion 34i, the inlet 30i and the outlet 30o are not formed in a portion existing in the static pressure rise region R, within the range of the upstream-side angle θu from the collision gas axis Ai to the upstream side Dau and within the range of the downstream-side angle θd from the collision gas axis Ai to the downstream side Dad.
Here, in the plurality of impingement flow paths 33i, the impingement flow path 33i in which the impingement circumvention flow path portion 34i is closest to the insertion opening 25 will be referred to as a first impingement flow path 33i1. The impingement flow path 33i adjacent to the circumferential first side Dc1 with respect to the first impingement flow path 33i1 will be referred to as a second impingement flow path 33i2, and the impingement flow path 33i adjacent to the circumferential first side Dc1 with respect to the second impingement flow path 33i2 will be referred to as a third impingement flow path 33i3. As illustrated in
Each of the plurality of normal flow paths 31 and the plurality of complementary flow paths 32 is a linear flow path extending in the cylinder axis direction Da. One of the inlet 30i and the outlet 30o is formed in an end of the upstream side Dau in the plurality of normal flow paths 31 and the plurality of complementary flow paths 32. In addition, the other of the inlet 30i and the outlet 30o is formed in an end of the downstream side Dad in the plurality of normal flow paths 31 and the plurality of complementary flow paths 32.
All of the plurality of complementary flow paths 32 exist inside the region in the circumferential direction Dc where the circumvention flow path portion 34 of at least one opening circumference flow path 33 in the plurality of opening circumference flow paths 33 exists, and are located at the same position in the cylinder axis direction Da with respect to a portion of the circumvention flow path portion 34 of at least one opening circumference flow path 33. In the present embodiment, all of the inlets 30i for each of the plurality of complementary flow paths 32 are formed in the ends on the side close to the insertion opening 25 in the cylinder axis direction Da.
As described above, the plurality of normal flow paths 31 are flow paths excluding the plurality of opening circumference flow paths 33 and the plurality of complementary flow paths 32 in the plurality of cooling flow paths 30. In the present embodiment, in the plurality of normal flow paths 31, some of the normal flow paths 31 are adjacent to a side far from the insertion opening 25 in the circumferential direction Dc with respect to the circumvention flow path portion 34 of one opening circumference flow path 33. As described above, the circumvention flow path portion 34 has an arc shape, and the normal flow path 31 has a linear shape. Therefore, a portion having a short distance therebetween and a portion having a long distance therebetween exist between the normal flow path 31 and the circumvention flow path portion 34 in the circumferential direction Dc. In the plurality of complementary flow paths 32, some of the complementary flow paths 32a are disposed in the portion having the long distance therebetween, between the normal flow path 31 and the circumvention flow path portion 34 in the circumferential direction Dc, and play a role of cooling a portion thereof. In addition, in the plurality of complementary flow paths 32, the other complementary flow paths 32b are disposed between the upstream-side flow path portions 35 or between the downstream-side flow path portions 36 of the two opening circumference flow paths 33 adjacent to each other in the circumferential direction Dc, and play a role of cooling the portion therebetween.
A temperature of the cooling medium flowing through a portion of the cooling flow path 30 which is close to the outlet 30o of the cooling flow path 30 is higher than a temperature of the cooling medium flowing through a portion of the cooling flow path 30 which is close to the inlet 30i of the cooling flow path 30. Therefore, cooling capacity of a portion close to the outlet 30o of the cooling flow path 30 in the cooling flow path 30 is smaller than cooling capacity of a portion close to the inlet 30i of the cooling flow path 30 in the cooling flow path 30. Therefore, when the outlets 30o of the two cooling flow paths 30 adjacent to each other in the circumferential direction Dc are located at the same position in the cylinder axis direction Da, the cooling capacity of the portion close to each outlet 30o of the two cooling flow paths 30 becomes extremely low. In the present embodiment, the outlets 30o of the two cooling flow paths 30 adjacent to each other in the circumferential direction Dc are located at positions different from each other in the cylinder axis direction Da. Therefore, it is possible to prevent the cooling capacity of the portion close to each outlet 30o of the two cooling flow paths 30 from becoming extremely low.
The barrel 21 of the present embodiment has the plurality of opening circumference flow paths 33 having the circumvention flow path portion 34 extending along the edge of the insertion opening 25. Therefore, in the present embodiment, the edge of the insertion opening 25 can be cooled by the cooling medium flowing through the circumvention flow path portion 34.
In the present embodiment, in the static pressure rise region R around the air supply pipe 40, the impingement circumvention flow path portion 34i of the impingement flow path 33i is formed along the edge of the insertion opening 25. The outlet 30o of the impingement flow path 33i is not formed in a portion inside the static pressure rise region R in the impingement circumvention flow path portion 34i. Therefore, even when the combustion gas G inside the barrel 21 collides with the air supply pipe 40 and the static pressure of the combustion gas G rises inside the static pressure rise region R, it is possible to prevent a backflow of the combustion gas G into the impingement flow path 33i.
In addition, in the present embodiment, in the plurality of impingement flow paths 33i, the flow path cross-sectional area of the first impingement flow path 33i1 in which the impingement circumvention flow path portion 34i is closest to the insertion opening 25 is wider than the flow path cross-sectional area of the other impingement flow paths 33i. Therefore, a flow rate of the compressed air serving as the cooling medium flowing through the first impingement flow path 33i1 is higher than a flow rate of the compressed air serving as the cooling medium flowing through the other impingement flow paths 33i. Furthermore, in the present embodiment, all of the inlets 30i for each of the plurality of complementary flow paths 32 are formed in the ends on the side close to the insertion opening 25 in the cylinder axis direction Da. Therefore, in the present embodiment, the portion of the barrel 21 which is close to the insertion opening 25 can be actively cooled.
In the present embodiment, from the above-described viewpoint, it is possible to prevent burning of the barrel 21 in the vicinity of the air supply pipe 40, and it is possible to improve durability of the combustion cylinder 20.
A first modification example of the combustor cylinder in the above-described embodiment will be described with reference to
As in the combustor cylinder in the first embodiment, the combustor cylinder of the present modification example is a combustion cylinder 20a. The combustion cylinder 20a of the present modification example is different from the combustion cylinder 20 in the first embodiment in shapes and disposition of the plurality of cooling flow paths, and other configurations are the same.
Also in the present modification example, as in the above-described embodiment, a part of the plurality of cooling flow paths 30 forms a plurality of opening circumference flow paths 33a, another part forms the complementary flow path 32, and the remaining part forms the normal flow path 31.
All of the plurality of opening circumference flow paths 33a in the present modification example are the impingement flow paths 33i. That is, the plurality of opening circumference flow paths 33a in the present modification example do not include the non-impingement flow path 33n in the above-described embodiment.
As in the impingement flow path 33i in the above-described embodiment, each of the plurality of impingement flow paths 33i has the impingement circumvention flow path portion 34i extending along the edge of the insertion opening 25 and forming an arc shape.
As in the above-described embodiment, the impingement circumvention flow path portion 34i for each of the plurality of impingement flow paths 33i intersects with the collision gas axis Ai. The intersection position 34p intersecting with the collision gas axis Ai is located on the upstream side Dau of the pipe center axis At and in the circumferential direction Dc of the pipe center axis At. The impingement circumvention flow path portion 34i extends in a direction having a direction component of the upstream side Dau from the collision gas axis Ai along the edge of the insertion opening 25, and extends in a direction having a direction component of the downstream side Dad from the collision gas axis Ai along the edge of the insertion opening 25. The inlet 30i and the outlet 30o are not formed in the portion existing in the static pressure rise region R in the impingement circumvention flow path portion 34i.
Of the plurality of impingement flow paths 33i, a first impingement flow path 33i1a in which the impingement circumvention flow path portion 34i is closest to the insertion opening 25 does not have the upstream-side flow path portion 35 and the downstream-side flow path portion 36, unlike the first impingement flow path 33i1 in the above-described embodiment. Therefore, in the impingement circumvention flow path portion 34i of the first impingement flow path 33i1a in the present modification example, the inlet 30i is formed in one end of the impingement circumvention flow path portion 34i, and the outlet 30o is formed in the other end. However, as described above, the outlet 30o is not formed inside the static pressure rise region R. Meanwhile, in the plurality of impingement flow paths 33i, as in the second impingement flow path 33i2 and the third impingement flow path 33i3 in the first embodiment, the second impingement flow path 33i2 and the third impingement flow path 33i3 have the upstream-side flow path portion 35 and the downstream-side flow path portion 36, in addition to the impingement circumvention flow path portion 34i.
Also in the present modification example, as in the above-described embodiment, the impingement circumvention flow path portion 34i of the impingement flow path 33i is formed along the edge of the insertion opening 25 in the static pressure rise region R around the air supply pipe 40. The outlet 30o of the impingement flow path 33i is not formed in a portion inside the static pressure rise region R in the impingement circumvention flow path portion 34i. Therefore, even when the combustion gas G inside the barrel 21 collides with the air supply pipe 40 and the static pressure of the combustion gas G rises inside the static pressure rise region R, it is possible to prevent a backflow of the combustion gas G into the impingement flow path 33i.
As described above, when the impingement circumvention flow path portion 34i exists in the static pressure rise region R around the air supply pipe 40, it is not necessary to substantially cover the entire circumference of the insertion opening 25 with the circumvention flow path portion 34 of the plurality of opening circumference flow paths 33 as in the first embodiment. In addition, as long as the impingement circumvention flow path portion 34i is provided, the impingement flow path 33i may not have the upstream-side flow path portion 35 and the downstream-side flow path portion 36. In addition, the inlet 30i and the outlet 30o may be formed in the impingement circumvention flow path portion 34i.
In the plurality of complementary flow paths 32 in the present modification example, the inlets 30i of some of the complementary flow paths 32 are formed in the ends on the side close to the insertion opening 25 in the cylinder axis direction Da. In addition, in the plurality of complementary flow paths 32 in the present modification example, the inlets 30i of some of the complementary flow paths 32c are formed in the ends on the side far from the insertion opening 25 in the cylinder axis direction Da. That is, the inlets 30i for each of all of the complementary flow paths 32 may not be formed in the ends on the side close to the insertion opening 25 in the cylinder axis direction Da.
A second modification example of the combustion cylinder in the first embodiment will be described with reference to
As in the combustor cylinder in the above-described embodiment, the combustor cylinder of the present modification example is a combustion cylinder 20b. The combustion cylinder 20b of the present modification example is different from the combustion cylinder 20 in the first embodiment in shapes of the plurality of circumvention flow path portions, and other configurations are the same.
All of the circumvention flow path portions 34 in the above-described embodiment form an arc shape in accordance with a shape of the circular insertion opening 25. On the other hand, all of the circumvention flow path portions 34b of the present modification example do not have the arc shape, and have a shape in which a plurality of straight line portions are connected to each other. Even when the circumvention flow path portion 34b has this shape, as long as the circumvention flow path portion 34b extends along the edge of the insertion opening 25, it is possible to achieve substantially the same advantageous effect as that of the circumvention flow path portion 34 in the above-described embodiment. However, a pressure loss of the compressed air A in the arc-shaped circumvention flow path portion 34 is smaller than that in the circumvention flow path portion 34b having this shape. Accordingly, when it is not difficult to manufacture the arc-shaped circumvention flow path portion 34, it is preferable that the circumvention flow path portion has the arc shape.
In the above-described embodiment and each modification example, the fuel swirl angle of and the collision axis angle θi are substantially the same. However, depending on a relationship between a ratio of the injection flow rate of the fuel F to the injection flow rate of the combustion air A1 and the swirl angle of the combustion air A1, the collision axis angle θi with respect to the fuel swirl angle θf may vary within a range of the fuel swirl angle of θf ±15° in some cases. Therefore, the collision axis angle θi, which is an angle of the collision gas axis Ai with respect to the cylinder axis Ac, is not limited to 40°, and may be any angle within a range of an angle of 40°±15°.
Some combustors do not swirl the combustion gas G around the cylinder axis Ac inside the combustion space. In this case, the collision gas axis Ai extends in the cylinder axis direction Da. That is, the collision axis angle θi, which is an angle of the collision gas axis Ai with respect to the cylinder axis Ac, may be 0°.
In the above-described embodiment and each modification example, the air supply pipe 40 is attached to the barrel 21 of the combustion cylinder 20. However, when the length of the large-diameter barrel 13c of the inner cylinder 13 in the cylinder axis direction Da is long, the air supply pipe 40 may be attached to the large-diameter barrel 13c in some cases. In this case, the barrel of the combustion cylinder including the air supply pipe 40 is the large-diameter barrel 13c of the inner cylinder 13.
The fuel F in the above-described embodiment and each modification example is mainly BFG. However, the fuel F may be another fuel F. Specifically, the fuel F may be a natural gas or COG.
For example, the combustor cylinder in the above-described embodiment and modification examples is understood as follows.
(1) According to a first aspect, there is provided the combustor cylinder including the barrel 21 that forms a cylindrical shape around the cylinder axis Ac and that defines the circumference of the combustion space S through which the combustion gas G flows in a direction having a direction component from, of the upstream side Dau and the downstream side Dad in the cylinder axis direction Da in which the cylinder axis Ac extends, the upstream side Dau to the downstream side Dad, and the air supply pipe 40 attached to the barrel 21. The cylindrical barrel 21 has the inner peripheral surface 23i facing the combustion gas G, the outer peripheral surface 22o facing the side opposite to the inner peripheral surface 23i, the insertion opening 25 that penetrates the inner peripheral surface 23i from the outer peripheral surface 22o, and the plurality of cooling flow paths 30 extending between the inner peripheral surface 23i and the outer peripheral surface 22o in the direction along the inner peripheral surface 23i and through the inside of which the cooling medium flows. A part of the air supply pipe 40 is inserted into the inner peripheral side of the barrel 21 from the insertion opening 25, and protrudes to the inner peripheral side of the barrel 21. Each of the plurality of cooling flow paths 30 has the inlet 30i configured to introduce the cooling medium into the cooling flow path 30, and the outlet 30o configured to discharge the cooling medium flowing into the cooling flow path 30. The plurality of cooling flow paths 30 have the plurality of opening circumference flow paths 33, as some cooling flow paths 30 in the plurality of cooling flow paths 30. The plurality of opening circumference flow paths 33 have the circumvention flow path portion 34 extending along the edge of the insertion opening 25. In the plurality of opening circumference flow paths 33, at least one opening circumference flow path 33 forms the impingement flow path 33i. The impingement flow path 33i has the impingement circumvention flow path portion 34i, as the circumvention flow path portion 34. The impingement circumvention flow path portion 34i intersects with the collision gas axis Ai extending in the flowing direction of, of the combustion gas G, the combustion gas G directed toward the pipe center axis At, which is the radial direction of the air supply pipe 40 with respect to the pipe center axis At, extends in the direction having the direction component of the upstream side Dau along the edge of the insertion opening 25 from the collision gas axis Ai, and extends in the direction having the direction component of the downstream side Dad along the edge of the insertion opening 25 from the collision gas axis Ai. In the impingement circumvention flow path portion 34i, the intersection position 34p intersecting with the collision gas axis Ai is located on the upstream side Dau of the pipe center axis At. In the impingement circumvention flow path portion 34i, the outlet 30o which opens on the inner peripheral surface 23i is not formed in the portion within a range of a predetermined angle (θu+θd) around the collision gas axis Ai which is the angle around the pipe center axis At.
When the combustion gas G flowing inside the barrel 21 collides with the air supply pipe 40, whereas a dynamic pressure thereof is lowered, a static pressure thereof rises. The static pressure rise region R in which the combustion gas G collides with the air supply pipe 40 and the static pressure of the combustion gas G rises is within the range of the predetermined upstream-side angle θu from the collision gas axis Ai to the upstream side Dau, which is the angle around the pipe center axis At, and is within the range of the predetermined downstream-side angle θd from the collision gas axis Ai to the downstream side Dad. In the present aspect, the plurality of opening circumference flow paths 33 having the circumvention flow path portion 34 extending along the edge of the insertion opening 25 are provided. Therefore, the edge of the insertion opening 25 can be cooled by the cooling medium flowing through the circumvention flow path portion 34. Moreover, in the present aspect, the outlet 30o of the impingement flow path 33i having the impingement circumvention flow path portion 34i is not formed in the portion inside the static pressure rise region R in the impingement circumvention flow path portion 34i. Therefore, in the present aspect, even when the combustion gas G inside the barrel 21 collides with the air supply pipe 40 and the static pressure of the combustion gas G rises inside the static pressure rise region R, it is possible to prevent a backflow of the combustion gas G into the impingement flow path 33i.
(2) According to a second aspect of the combustor cylinder, in the combustor cylinder according to the first aspect, the predetermined angle (θu+θd) is 60°±20°.
The predetermined angle (θu+θd) varies depending on the flow speed immediately before the combustion gas G collides with the air supply pipe 40. Therefore, the predetermined angle (θu+θd) is 60°±20°.
(3) According to a third aspect of the combustor cylinder, in the combustor cylinder according to the first aspect or the second aspect, the collision gas axis Ai forms the angle θi of 40°±15° with respect to the cylinder axis Ac.
When the fuel F is swirled around the cylinder axis Ac inside the combustion space S on the inner peripheral side of the barrel 21, the collision axis angle θi, which is the angle of the collision gas axis Ai with respect to the cylinder axis Ac, is approximately 40°. However, the collision axis angle θi slightly varies depending on the relationship between the ratio of the injection flow rate of the fuel F to the injection flow rate of the combustion air A1 and the swirl angle of the combustion air A1. Therefore, the collision axis angle θi is not limited to 40°, and may be any angle within an angle range of 40°±15°.
(4) According to a fourth aspect of the combustor cylinder, in the combustor cylinder according to any one of the first aspect to the third aspect, the plurality of opening circumference flow paths 33 have the upstream-side flow path portion 35 extending from the end of the upstream side Dau of the circumvention flow path portion 34 to the upstream side Dau in the cylinder axis direction Da. The upstream-side flow path portion 35 has one of the inlet 30i and the outlet 30o.
(5) According to a fifth aspect of the combustor cylinder, in the combustor cylinder according to any one of the first aspect to the fourth aspect, the plurality of opening circumference flow paths 33 have the downstream-side flow path portion 36 extending from the end of the downstream side Dad of the circumvention flow path portion 34 to the downstream side Dad in the cylinder axis direction Da.
(6) According to a sixth aspect of the combustor cylinder, in the combustor cylinder according to any one of the first aspect to the third aspect, the plurality of opening circumference flow paths 33 have the upstream-side flow path portion 35 extending from the end of the upstream side Dau of the circumvention flow path portion 34 to the upstream side Dau in the cylinder axis direction Da, and the downstream-side flow path portion 36 extending from the end of the downstream side Dad of the circumvention flow path portion 34 to the downstream side Dad in the cylinder axis direction Da. One of the inlet 30i and the outlet 30o is formed in the upstream-side flow path portion 35, and the other of the inlet 30i and the outlet 30o is formed in the downstream-side flow path portion 36. The inlet 30i and the outlet 30o are not formed in the circumvention flow path portion 34.
In the present aspect, the outlet 30o of the opening circumference flow path 33 is not formed in the circumvention flow path portion 34 extending along the edge of the insertion opening 25. Therefore, in the present aspect, it is possible to prevent a backflow of the combustion gas G into the circumvention flow path portion 34.
(7) According to a seventh aspect of the combustor cylinder, in the combustor cylinder according to any one of the first aspect to the sixth aspect, the plurality of cooling flow paths 30 have the complementary flow paths 32 extending in the cylinder axis direction Da, as some cooling flow paths 30 in the plurality of cooling flow paths 30. The complementary flow paths 32 exist inside the region in the circumferential direction Dc with respect to the cylinder axis Ac where the circumvention flow path portion 34 of at least one opening circumference flow path 33 in the plurality of opening circumference flow paths 33 exists, and are located at the same position in the cylinder axis direction Da with respect to a portion of the circumvention flow path portion 34 of the at least one opening circumference flow path 33.
In some cases, as one cooling flow path 30 in the plurality of cooling flow paths 30, the normal flow path 31 linearly extending in the cylinder axis direction Da may be provided on the side far from the insertion opening 25 in the circumferential direction Dc with respect to the cylinder axis Ac, with respect to the circumvention flow path portion 34 of the opening circumference flow path 33. In this case, a portion having a short distance therebetween and a portion having a long distance therebetween exist between the normal flow path 31 and the circumvention flow path portion 34 in the circumferential direction Dc. In the plurality of complementary flow paths 32, some of the complementary flow paths 32 are disposed in the portion having the long distance therebetween, between the normal flow path 31 and the circumvention flow path portion 34 in the circumferential direction Dc. Accordingly, in the present aspect, the portion having the long distance between the normal flow path 31 and the circumvention flow path portion 34 in the circumferential direction Dc can be cooled by the cooling medium flowing through the complementary flow path 32.
(8) According to an eighth aspect of the combustor cylinder, in the combustor cylinder according to the seventh aspect, the inlet 30i of the complementary flow path 32 is formed in, of both ends of the complementary flow path 32 in the cylinder axis direction Da, the end on the side close to the insertion opening 25.
In the present aspect, the vicinity of the insertion opening 25 can be actively cooled by the cooling medium flowing into the complementary flow path 32 from the inlet 30i of the complementary flow path 32.
(9) According to a ninth aspect of the combustor cylinder, in the combustor cylinder according to any one of the first aspect to the eighth aspect, the plurality of opening circumference flow paths 33 have a plurality of the impingement flow paths 33i. The impingement circumvention flow path portion 34i of, of the plurality of impingement flow paths 33i, the first impingement flow path 33i1 is closer to the insertion opening 25 than the impingement circumvention flow path portion 34i, of the plurality of impingement flow paths 33i, of another impingement flow path 33i excluding the first impingement flow path 33i1. The flow path cross-sectional area of the first impingement flow path 33i1 is wider than the flow path cross-sectional area of the other impingement flow path 33i.
In the present aspect, the flow path cross-sectional area of the first impingement flow path 33i1 is wider than the flow path cross-sectional area of the other impingement flow path 33i. Therefore, the flow rate of the cooling medium flowing through the first impingement flow path 33i1 is higher than the flow rate of the cooling medium flowing through the other impingement flow path 33i. Therefore, in the present aspect, in the above-described static pressure rise region R, the vicinity of the insertion opening 25 can be actively cooled.
(10) According to a tenth aspect of the combustor cylinder, in the combustor cylinder according to any one of the first aspect to the ninth aspect, in the plurality of cooling flow paths 30, the outlets 30o of two cooling flow paths 30 adjacent to each other in the circumferential direction Dc with respect to the cylinder axis Ac are located at positions different from each other in the cylinder axis direction Da.
A temperature of the cooling medium flowing through a portion of the cooling flow path 30 which is close to the outlet 30o of the cooling flow path 30 is higher than a temperature of the cooling medium flowing through a portion of the cooling flow path 30 which is close to the inlet 30i of the cooling flow path 30. Therefore, cooling capacity of a portion close to the outlet 30o of the cooling flow path 30 in the cooling flow path 30 is smaller than cooling capacity of a portion close to the inlet 30i of the cooling flow path 30 in the cooling flow path 30. Therefore, when the outlets 30o of the two cooling flow paths 30 adjacent to each other in the circumferential direction Dc are located at the same position in the cylinder axis direction Da, the cooling capacity of the portion close to each outlet 30o of the two cooling flow paths 30 becomes extremely low. In the present aspect, the outlets 30o of the two cooling flow paths 30 adjacent to each other in the circumferential direction Dc are located at positions different from each other in the cylinder axis direction Da. Therefore, it is possible to prevent the cooling capacity of the portion close to each outlet 30o of the two cooling flow paths 30 from becoming extremely low.
For example, the combustor in the above-described embodiment and modification examples is understood as follows.
(11) According to an eleventh aspect, there is provided the combustor including the combustor cylinder according to any one of the first aspect to the tenth aspect, and the burner 14 disposed on the upstream side Dau of the insertion opening 25 and configured to inject the fuel F into the combustion space S. The burner 14 has the burner frame 15 having the annular fuel injection port 14j around the cylinder axis Ac, and the swirler 16 provided inside the burner frame 15 and configured to swirl the fuel F ejected from the fuel injection port 14j around the cylinder axis Ac. The swirler 16 is configured so that the angle of the fuel F ejected from the fuel injection port 14j with respect to the cylinder axis Ac becomes the predetermined fuel swirl angle θf. The angle of the collision gas axis Ai with respect to the cylinder axis Ac is within the range of the fuel swirl angle θf ±15°.
When the fuel F is swirled around the cylinder axis Ac inside the combustion space S on the inner peripheral side of the barrel 21, the collision axis angle θi, which is the angle of the collision gas axis Ai with respect to the cylinder axis Ac, substantially becomes the fuel swirl angle θf. However, the collision axis angle θi slightly varies depending on the relationship between the ratio of the injection flow rate of the fuel F to the injection flow rate of the combustion air A1 and the swirl angle of the combustion air A1. Therefore, the collision axis angle θi does not need to completely coincide with the fuel swirl angle θf, and may be any angle within the angle range of the fuel swirl angle θf ±15°.
(12) According to a twelfth aspect of the combustor, in the combustor according to the eleventh aspect, the combustor further includes the air injector 17 disposed on the upstream side Dau of the insertion opening 25 and configured to diffuse and combust the fuel F injected from the burner 14 in the combustion space S by injecting the air into the combustion space S.
For example, the gas turbine in the above-described embodiment and modification examples is understood as follows.
(13) According to a thirteenth aspect, there is provided the gas turbine including the combustor according to the eleventh aspect or the twelfth aspect, the compressor 1 configured to feed the compressed air A to the combustor, and the turbine 5 configured to be driven by the combustion gas G from the combustor.
According to one aspect of the present disclosure, it is possible to improve durability of the combustor cylinder.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-028331 | Feb 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/007623 | 2/24/2022 | WO |
