COOLING CHANNEL STRUCTURE AND BURNER

Abstract

A cooling channel structure (100A-100G), comprising: a tubular element (5, 32) with openings at both ends, wherein the cooling channel structure (100A-100G) comprises cooling channels for flowing / conducting a cooling medium for cooling the tubular element (5, 32): a multitude of spiral outer surface channels (9a-9f) located on an outer surface side of the tubular element (5, 32), at least one inner surface channel (6a-6f) located on an inner surface side of the tubular element (5, 32), and a plurality of folded channels (8a-8f) which each connect the plurality of outer surface channels (9a-9f) and the at least one inner surface channel (6a-6f) at one end side of the tubular element (5, 32), wherein at least either the outer surface channels (9a-9f) or the inner surface channel (6a-6f) includes / comprises a section (18, 20) in which a channel cross-sectional area changes depending on an axial position on the tubular element (5, 32).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a cooling channel structure and a burner. BACKGROUND

[0002] To cool a structure exposed to a high-temperature atmosphere, a cooling channel through which a low-temperature cooling medium flows may be provided in an interior portion (the structure itself) or on the surface of the structure. For example, Patent Document 1 discloses a cooling channel structure in which a single cooling tube is spirally wound around a tubular structure (tubular member) to cool the structure. Furthermore, Patent Document 2 discloses a cooling channel structure in which a structure is cooled using a shield tube internally including a plurality of cooling channels extending along the axial direction.

[0003] Although the structure can be uniformly cooled, in the configuration described in Patent Document 1, a channel of the cooling pipe is likely to be long, the pressure loss in the cooling channel is high, and the driving force for supplying the cooling medium is high. Furthermore, in the configuration of Patent Document 2, since the structure is cooled using a plurality of cooling channels extending along the axial direction, even though a single cooling channel may be shorter than in the configuration of Patent Document 1, it is difficult to uniformly cool the structure in the event of unbalanced heat load distribution on the structure, possibly resulting in uneven cooling of the structure.

[0004] Meanwhile, Patent Document 3 discloses a cooling channel structure in which a tubular structure is cooled using a plurality of spiral channels extending from one end of the structure to the other end. With such a configuration, the channel length of the spiral channel can be shortened compared to a case where the structure is cooled by a single spiral channel, making it possible to cool the structure uniformly while preventing an increase in pressure loss in a cooling channel.

[0005] Patent Document 4 discloses a device including a passage for injecting material; an inner inflow part through which cooling water flows from the rear end of the passage to the front end; and an outer outflow part through which cooling water flows from the front end of the passage to the rear end, each extending through a passage wall; and an annular passage tip part disposed at the front end of the passage and connecting the inner and outer water passages to allow water to flow. The annular passage tip part includes an annular inner end part, an annular outer end part, an annular central part disposed between the inner end part and the outer end part; and a partition device for dividing a space between the outer end part and the central part into individual radial passages. Literature listPatent literature Patent Document 1: JP 2018-132248 A Patent Document 2: JP 2015-161460 A Patent Document 3: JP 2018-91599 A Patent Document 4: JP 2008-190854 A SUMMARYTechnical problem

[0006] Since the cooling channel structure disclosed in Patent Document 3 flows a cooling medium only in one direction in the axial direction through the tubular structure, it is necessary to install an inlet and an outlet for the cooling medium at one end and another end of the tubular structure, respectively. Therefore, if the tubular structure has a configuration in which the inlet and outlet for the cooling medium can be installed only on one side of the tubular structure, such as a combustor tube or a nozzle skirt of a rocket engine, the cooling channel structure of Patent Document 3 is not applicable.

[0007] In view of the above, an object of the present disclosure is to provide a cooling channel structure and a burner in which a tubular member is uniformly cooled while preventing an increase in pressure loss of the cooling medium, and in which the cooling medium can enter and exit from one side of the tubular member. Solution to the problem

[0008] To achieve the above-described object, the present invention discloses a cooling channel structure according to independent claims 1 and 12 and a burner according to independent claim 13. Advantageous modifications can be found in dependent claims 2 to 11. Beneficial effects

[0009] According to the present disclosure, a cooling channel structure and a burner are provided in which a tubular member is uniformly cooled while preventing an increase in pressure loss of a cooling medium, and in which the cooling medium can enter and exit from one side of the tubular member. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a vertical cross-sectional view showing the schematic structure of a burner 2 according to an embodiment. Fig. 2 is a side view of a burner tube 5 (5A) according to an embodiment. Fig. 3 is a front view of the burner tube 5 (5A). Fig. 4 is a cross-sectional view of the burner tube 5 (5A) along the Fig. Line AA shown in Figure 3. Fig. Figure 5 is a partially enlarged view of the burner tube 5 (5A) along the Fig. Line AA shown in Figure 3. Fig. 6 is a vertical cross-sectional view showing the schematic structure of the burner tube according to a comparative embodiment. Fig. 7 is a partially enlarged perspective view of a burner tube 5 (5B) according to another embodiment. Fig. Fig. 8 is a vertical cross-sectional view of a burner tube 5 (5C) according to another embodiment. Fig. 9 is a vertical cross-sectional view of a burner tube 5 (5D) according to another embodiment. Fig. 10 is a perspective view showing the schematic structure of a burner tube 5 (5E) according to another embodiment. Fig. 11 is a schematic view showing the configuration example of a header 12 according to an embodiment. Fig. 12 is a schematic view showing the configuration example of the header 12 according to an embodiment. Fig. 13 is a vertical cross-sectional view of a burner tube 5 (5F) according to another embodiment. Fig. 14 is a partial cross-sectional view showing the schematic structure of a nozzle skirt 32 of a rocket engine according to another embodiment. DETAILED DESCRIPTION

[0010] Embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, and the like of the components described or illustrated in the drawings as embodiments are intended to be interpreted as illustrative only and are not intended to limit the scope of the present invention.

[0011] For example, an expression for a relative or absolute arrangement, such as "in one direction", "along one direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial", should not be interpreted as indicating only the arrangement in the strict literal sense, but also includes a condition in which the arrangement is relatively shifted by a tolerance, or an angle or a distance and thereby it is possible to achieve the same function.

[0012] For example, an expression for an equivalent state, such as "equal", "equivalent" and "uniform", should not be interpreted as indicating only the state in which the characteristic is equivalent in the strict sense, but also includes a state in which a tolerance or difference exists and the same function can still be achieved.

[0013] Furthermore, for example, an expression for a shape such as a rectangular shape or a cylindrical shape should not be construed as indicating only the shape in the strict geometric sense, but also includes a shape with unevenness or bevelled corners in an area where the same effect can be achieved.

[0014] On the other hand, the terms “comprising”, “including”, “having”, “containing” and “constituting” in connection with a constituting component do not constitute exhaustive terms which exclude the presence of other constituting components.

[0015] Fig. Figure 1 is a vertical cross-sectional view showing the schematic structure of a burner 2 according to an embodiment. The burner 2 is used, for example, in a gasification furnace of a coal gasification device or the like, in a conventional boiler, in an incinerator, in a gas turbine combustor, or in a prime mover.

[0016] The burner 2 comprises a fuel nozzle 4 for injecting fuel, and a burner tube 5 arranged around the fuel nozzle 4 on the same axis CL as the fuel nozzle 4 for conducting air, which serves as an oxidizer for the combustion of the fuel. The burner tube 5 is a tubular element which has openings at both ends and functions as a shielding tube for shielding heat. A swirl device 30 is arranged between the outer peripheral surface of the fuel nozzle 4 and the inner peripheral surface of the burner tube 5. The burner tube 5 is arranged such that it penetrates a wall 28 of a combustion chamber 26 in which a flame is formed. The proximal end of the burner tube 5 is located outside the combustion chamber 26, while the distal end of the burner tube 5 is located inside the combustion chamber 26.For example, a flange or the like may be arranged on the proximal end side of the burner tube 5 to be connected to an air supply pipe (not shown) for supplying air.

[0017] Hereinafter, the axial direction of the burner tube 5 is referred to as the "axial direction" for the sake of simplicity, the radial direction of the burner tube 5 is referred to as the "radial direction" for the sake of simplicity, and the circumferential direction of the burner tube 5 is referred to as the "circumferential direction" for the sake of simplicity. Furthermore, an inner portion of the burner tube 5 hereinafter refers to a thick inner portion of the burner tube 5.

[0018] Next, with reference to Fig. 2 to 5 an example of the schematic structure of the burner tube 5 is described. Fig. 2 is a side view of a burner tube 5 (5A) according to an embodiment. Fig. 3 is a front view of the burner tube 5 (5A). Fig. 4 is a cross-sectional view of the burner tube 5 (5A) along the Fig. Line AA shown in Figure 3. Fig. Figure 5 is a partially enlarged view of the burner tube 5 (5A) along the Fig. Line AA shown in Figure 3.

[0019] As in Fig. 2 to 5, in an inner portion of the burner tube 5 (5A), a plurality of spiral inner surface side channels 6a to 6f located on an inner surface side of the burner tube 5, a plurality of spiral outer surface side channels 9a to 9f located on an outer surface side of the burner tube 5, and a plurality of folded channels 8a to 8f each connecting the plurality of inner surface side channels 6a to 6f and the plurality of outer surface side channels 9a to 9f on a distal end side (one end side) of the burner tube 5 are provided as cooling channels for flowing / guiding a cooling medium.

[0020] In the exemplary embodiment, the six inner surface side channels 6a to 6f are arranged on the inner surface side of the burner tube 5, the six outer surface side channels 9a to 9f are arranged on the outer surface side of the burner tube 5, and the six folded channels 8a to 8f are arranged on the distal end side of the burner tube 5.

[0021] The folded channel 8a connects the inner surface side channel 6a with the outer surface side channel 9a, the folded channel 8b connects the inner surface side channel 6b with the outer surface side channel 9b, the folded channel 8c connects the inner surface side channel 6c with the outer surface side channel 9c, the folded channel 8d connects the inner surface side channel 6d with the outer surface side channel 9d, the folded channel 8e connects the inner surface side channel 6e with the outer surface side channel 9e, and the folded channel 8f connects the inner surface side channel 6f with the outer surface side channel 9f.

[0022] As in Fig. 4 and Fig. 5, in a cross section along the axial direction of the burner tube 5, a channel cross section of the inner surface side channel 6a, a channel cross section of the inner surface side channel 6b, a channel cross section of the inner surface side channel 6c, a channel cross section of the inner surface side channel 6d, a channel cross section of the inner surface side channel 6e, and a channel cross section of the inner surface side channel 6f are arranged, for example, to repeat in this order from the proximal end side to the distal end side of the burner tube 5 along the axial direction.

[0023] As in Fig. 4 and Fig. 5, in the cross section along the axial direction of the burner tube 5, a channel cross section of the outer surface side channel 9a, a channel cross section of the outer surface side channel 9b, a channel cross section of the outer surface side channel 9c, a channel cross section of the outer surface side channel 9d, a channel cross section of the outer surface side channel 9e, and a channel cross section of the outer surface side channel 9f are further arranged, for example, to repeat in this order from the distal end side to the proximal end side of the burner tube 5 along the axial direction.

[0024] For example, in Fig. 2 and Fig. 4, in the inner portion of the burner tube 5, a header 12 is also arranged on the proximal end side of the burner tube 5, wherein the header 12 extends in the circumferential direction and thus connects end portions of the plurality of inner surface side channels 6a to 6f on the proximal end side. As shown in Fig. As shown in Figure 2, an inlet 14 for the cooling medium is arranged at the proximal end of the burner tube 5, and the head piece 12 is connected to the radially open inlet 14. The cooling medium flowing into the burner tube 5 from the inlet 14 flows separately through the head piece 12 into the plurality of inner surface-side channels 6a to 6f, and is discharged from outlets 16 in the plurality of outer surface-side channels 9a to 9f at the proximal end of the burner tube 5 through the folded channels 8a to 8f, respectively.

[0025] Specifically, the cooling medium flowing from the header 12 into the inner surface side channel 6a is sequentially guided through the inner surface side channel 6a, the folded channel 8a, and the outer surface side channel 9a, and is discharged from the burner tube 5 at the outlet 16 of the outer surface side channel 9a. The cooling medium flowing from the header 12 into the inner surface side channel 6b is sequentially guided through the inner surface side channel 6b, the folded channel 8b, and the outer surface side channel 9b, and is discharged from the burner tube 5 at the outlet 16 of the outer surface side channel 9b. The cooling medium flowing from the head piece 12 into the inner surface side channel 6c is guided in sequence through the inner surface side channel 6c, the folded channel 8c and the outer surface side channel 9c and is discharged from the burner tube 5 at the outlet 16 of the outer surface side channel 9c.The cooling medium flowing from the header 12 into the inner surface side channel 6d is guided in sequence through the inner surface side channel 6d, the folded channel 8d, and the outer surface side channel 9d and discharged from the burner tube 5 at the outlet 16 of the outer surface side channel 9d. The cooling medium flowing from the header 12 into the inner surface side channel 6e is guided in sequence through the inner surface side channel 6e, the folded channel 8e, and the outer surface side channel 9e and discharged from the burner tube 5 at the outlet 16 of the outer surface side channel 9e. The cooling medium flowing from the head piece 12 into the inner surface side channel 6f is guided in sequence through the inner surface side channel 6f, the folded channel 8f and the outer surface side channel 9f and is discharged from the burner tube 5 at the outlet 16 of the outer surface side channel 9f.

[0026] For example, in Fig. 3, the folded channels 8a to 8f are also curved such that a direction Ri in which the inner surface side channels 6a to 6f circulate to a downstream side along a spiral (a direction in which the cooling medium circulates along the spiral while moving through the inner surface side channels 6a to 6f to the downstream side) and a direction Ro in which the outer surface side channels 9a to 9f circulate to the downstream side along the spiral (a direction in which the cooling medium circulates along the spiral while moving through the outer surface side channels 9a to 9f to the downstream side) are identical.When viewing the burner tube 5 from the distal end side to its proximal end side along the axial direction, the direction Ri in which the inner surface side channels 6a to 6f circulate to the downstream side along the spiral and the direction Ro in which the outer surface side channels 9a to 9f circulate to the downstream side along the spiral are both counterclockwise in the illustrated form, thus being identical in direction.

[0027] In the Fig. In the burner tube 5 (5A) shown in Figures 2 to 5, the cooling channels through which the cooling medium flows to cool the burner tube 5 (5A) are formed in the inner portion of the burner tube 5 (5A) itself (the thick inner portion of the burner tube 5), wherein the burner tube 5 (5A) as such forms a cooling channel structure 100A. Such a burner tube 5 (5A) can be manufactured, for example, using a device suitable for three-dimensional additive manufacturing (so-called 3D printer). The cooling medium flowing through the cooling channels (the inner surface-side channels 6a to 6f, the folded channels 8a to 8f, and the outer surface-side channels 9a to 9f) can be, for example, a liquid such as water or oil, or a gas such as air.

[0028] Since the plurality of spiral outer surface side channels 9a to 9f are arranged on the outer surface side of the burner tube 5, with the above-described configuration, it is possible to prevent uneven cooling of the burner tube 5 and uniformly cool the burner tube 5, compared to a case where only the cooling channels along the axial direction are used for cooling the burner tube (see, for example, Patent Document 2 described above). Accordingly, it is possible to uniformly cool the burner tube 5 even in the case of unbalanced heat load distribution on the burner tube 5.

[0029] Furthermore, compared to a case where only a single spiral outer surface side channel is arranged on the outer surface side of the burner tube 5, it is possible to reduce the channel length required to cover the same area per spiral outer surface side channel, thereby preventing an increase in pressure loss and reducing a driving force for supplying the cooling medium. Consequently, it is possible to effectively cool the burner tube 5 using a driving source such as a pump or a fan with a low driving force.

[0030] In addition, since the plurality of inner surface side channels 6a to 6f and the plurality of outer surface side channels 9a to 9f are respectively connected to each other via the plurality of folded channels 8a to 8f at the distal end side of the burner tube 5, it is possible to combine the inlet 14 and the outlets 16 for the cooling medium in the burner tube 5 at the proximal end side of the burner tube 5.

[0031] Accordingly, it is possible to uniformly cool the burner tube 5 while preventing an increase in the pressure loss of the cooling medium, and it is possible to provide the burner tube 5 such that the cooling medium can enter and exit from one side (the proximal end side) of the burner tube 5.

[0032] Furthermore, since the folded channels 8a to 8f are curved such that the direction Ri in which the inner surface side channels 6a to 6f circulate to the downstream side along the spiral and the direction Ro in which the outer surface side channels 9a to 9f circulate to the downstream side along the spiral are identical, it is possible to smoothly reverse a flow direction of the cooling medium in the axial direction and prevent an increase in the pressure loss of the cooling medium.

[0033] In addition, since the header 12 connecting the end portions of the plurality of inner surface side channels 6a to 6f is disposed on the proximal end side of the burner tube 5, there is no need to individually connect each of the inner surface side channels 6a to 6f to an external cooling medium pipe, thereby making it possible to simplify the process of connecting each inner surface side channel 6a to 6f to the external cooling medium pipe.

[0034] In addition, since the burner tube 5 internally including the spiral inner surface side channels 6a to 6f and the spiral outer surface side channels 9a to 9f can be formed as a single component by means of the apparatus suitable for three-dimensional additive manufacturing, alignment between the respective components and dimensional management are easier compared to a case in which the burner tube and the cooling tubes are formed from separate components (for example, in a case in which the spiral cooling tubes as shown in Fig. 6, wound on the outer surface of the burner tube), simple.

[0035] As part of the Fig. 6, there is a need to appropriately manage the extent of an axial projection A of the respective tips of the cooling tubes relative to the tip of the burner tube and the extent of an axial projection B of the respective tips of the cooling tubes relative to the tip of the fuel nozzle, while in the configuration shown in Fig. 1 to 5, instead of the projection dimension A and the projection dimension B described above, only one projection dimension C (see Fig. 1) the tip of the burner tube 5 relative to the tip of the fuel nozzle 4 must be handled appropriately, thereby simplifying the alignment between the respective components and dimensional management.

[0036] Furthermore, the water-cooled shell structure described in Patent Document 2 is manufactured by subjecting the outer peripheral surface of the inner tube to channel groove machining and then sealing the channel groove with the outer tube. However, in this case, the high number of production steps is likely to increase production costs, and there are numerous problems, such as reliability regarding leakage from a close contact portion between the inner tube and the outer tube.In contrast, since the above-described burner tube 5 can provide the above-described inner surface-side channels 6a to 6f, folded channels 8a to 8f, and outer surface-side channels 9a to 9f integrally in the burner tube 5 using the apparatus suitable for three-dimensional additive manufacturing, it is possible to reduce the number of components, the number of production steps, and the production cost, and there is no need to perform the above-described channel groove closing process. Furthermore, the above-described inner surface-side channels 6a to 6f, folded channels 8a to 8f, and outer surface-side channels 9a to 9f can be configured to each have an appropriate channel cross-sectional area in accordance with a flow rate required for the cooling medium, thereby making it possible to effectively cool the burner tube 5.

[0037] According to the present disclosure, each of the inner surface side channels 6a to 6f includes a portion in which the channel cross-sectional area changes depending on the axial position. As shown in Fig. 4, the inner surface-side channels 6a to 6f may, for example, comprise a channel section 18 in which the channel cross-sectional areas decrease toward the folded channels 8a to 8f (toward the downstream side). Furthermore, each of the outer surface-side channels 9a to 9f may comprise a section in which the channel cross-sectional area changes depending on the axial position. As shown in Fig. 4, the outer surface side channels 9a to 9f can, for example, comprise a channel section 20 in which the channel cross-sectional areas decrease towards the folded channels 8a to 8f (towards the upstream side).

[0038] In the burner 2, the ambient temperature of the burner tube 5 tends to increase toward the distal end side. Therefore, by providing the inner surface-side channels 6a to 6f with the channel portion 18 as described above, in which the channel cross-sectional areas decrease toward the folded channels 8a to 8f on the distal end side, it is possible to effectively cool the burner tube 5 by increasing the flow velocity of the cooling medium in a region where the ambient temperature of the channel portion 18 tends to be high.Furthermore, by providing the outer surface side channels 9a to 9f with the channel portion 20 as described above in which the channel cross-sectional areas decrease toward the folded channels 8a to 8f on the distal end side, it is possible to effectively cool the burner tube 5 by increasing the flow velocity of the cooling medium in a region where the ambient temperature of the channel portion 20 tends to be high.

[0039] Consequently, in a case where the heat load distribution can be estimated in advance, it is possible to reduce thermal stress induced in the burner tube 5 by changing the channel cross-sectional areas of the inner surface side channels 6a to 6f and the outer surface side channels 9a to 9f depending on the axial positions. In another embodiment, such as in the Fig. 4, the cross-sectional shapes of the inner surface side channels 6a to 6f and the cross-sectional shapes of the outer surface side channels 9a to 9f can be changed depending on the axial positions together with the channel cross-sectional areas or instead of the channel cross-sectional areas.

[0040] Next, some other embodiments will be described. Unless otherwise specified, in the other embodiments to be described below, reference numerals that correspond to those for the corresponding constituent components of the above-mentioned embodiments denote the same constituent components as the corresponding constituent components of the above-mentioned embodiments, and therefore, their description will be omitted.

[0041] Fig. 7 is a partially enlarged perspective view of a burner tube 5 (5B) according to another embodiment.

[0042] For example, in Fig. 7, in some embodiments, the folded channels 8a to 8f are curved such that the direction Ri in which the inner surface side channels 6a to 6f circulate toward the downstream side along the spiral (the direction in which the cooling medium circulates along the spiral while moving through the inner surface side channels 6a to 6f toward the downstream side) and the direction Ro in which the outer surface side channels 9a to 9f circulate toward the downstream side along the spiral (the direction in which the cooling medium circulates along the spiral while moving through the outer surface side channels 9a to 9f toward the downstream side) are opposite to each other.When viewing the burner tube 5 from the distal end side to its proximal end side along the axial direction, the direction Ri in which the inner surface side channels 6a to 6f circulate to the downstream side along the spiral is counterclockwise in the illustrated form, and the direction Ro in which the outer surface side channels 9a to 9f circulate to the downstream side along the spiral is clockwise, thus being opposite to each other.

[0043] In the Fig. In the burner tube 5 (5B) shown in Fig. 7, the cooling channels through which the cooling medium flows to cool the burner tube 5 (5B) are formed in the inner portion of the burner tube 5 (5B) itself (the thick inner portion of the burner tube 5), the burner tube 5 (5B) as such forming a cooling channel structure 100B.

[0044] Although the pressure loss increases by reversing the flow direction of the cooling medium by 180 degrees in the folded channels 8a to 8f, it is possible to reduce the pressure loss by using the Fig. 7 compared to the configuration shown in Fig. 3, it is possible to reduce the thermal stress induced in the folded channels 8a to 8f.

[0045] Fig. Fig. 8 is a vertical cross-sectional view of a burner tube 5 (5C) according to another embodiment.

[0046] For example, in Fig. As shown in Fig. 8, in some embodiments, the header 12, which extends in the circumferential direction and thus connects the end portions of the plurality of inner surface-side channels 6a to 6f, and a header 22, which extends in the circumferential direction and thus connects the end portions of the plurality of outer surface-side channels 9a to 9f, are arranged on the proximal end side (another end side) of the burner tube 5. The header 22 is arranged on an outer peripheral side of the header 12.

[0047] In the Fig. In the burner tube 5 (5C) shown in Fig. 8, the cooling channels through which the cooling medium flows to cool the burner tube 5 (5C) are formed in the inner portion of the burner tube 5 (5C) itself (in the thick inner portion of the burner tube 5), the burner tube 5 (5C) as such forming a cooling channel structure 100C.

[0048] With the help of Fig. With the configuration shown in Figure 8, it is possible to realize a single inlet and a single outlet for the cooling medium in the burner tube 5. This means that there is no need to individually connect each of the inner surface side channels 6a to 6f to the external cooling medium pipe, thereby making it possible to simplify the process of connecting each of the inner surface side channels 6a to 6f to the external cooling medium pipe. Furthermore, there is no need to individually connect each of the outer surface side channels 9a to 9f to the external cooling medium pipe, thereby making it possible to simplify the process of connecting each of the outer surface side channels 9a to 9f to the external cooling medium pipe.

[0049] Fig. 9 is a vertical cross-sectional view of a burner tube 5 (5D) according to another embodiment.

[0050] For example, in Fig. 9, in some embodiments, each of the inner surface side channels 6a to 6f may extend not spirally, but linearly along the axial direction. Fig. 9, the cooling channels through which the cooling medium flows to cool the burner tube 5 (5D) are formed in the inner portion of the burner tube 5 (5D) itself (the thick inner portion of the burner tube 5), the burner tube 5 (5D) as such forming a cooling channel structure 100D.

[0051] By creating a Fig. 9 is used, it is possible to reduce the pressure loss by reducing the channel lengths of the inner surface side channels 6a to 6f, as compared with the case where each of the inner surface side channels 6a to 6f is formed spirally.

[0052] The present disclosure is not limited to the above-described embodiments, and also includes an embodiment obtained by modifying the above-described embodiments and an embodiment obtained by combining these embodiments, if necessary.

[0053] For example, in the context of Fig. In the embodiment shown in Figure 8, a configuration is described in which the plurality of inner surface side channels 6a to 6f extending linearly along the axial direction are arranged in the inner portion of the burner tube 5. However, only a single inner surface side channel may be arranged. If the burner tube 5 has only a single inner surface side channel, the inner surface side channel may be formed in an annular shape within the burner tube.

[0054] Furthermore, in some of the embodiments described above, the cases in which the burner tubes 5 (5A to 5D) per se constitute the respective cooling channel structures were exemplified. That is, a configuration in which the plurality of inner surface-side channels 6a to 6f, the plurality of folded channels 8a to 8f, and the plurality of outer surface-side channels 9a to 9f are integrally arranged in the inner portion of the burner tube 5 using a three-dimensional additive manufacturing method was exemplified. However, the burner tube 5 and the components constituting the cooling channels may also be separate components.

[0055] As part of the Fig. In the configuration shown in Fig. 10, each of the plurality of spiral inner surface-side channels 6a to 6f is formed from a corresponding one of the spiral cooling tubes arranged on an inner surface of a burner tube 5 (5E) along the inner surface of the burner tube 5, and each of the plurality of spiral outer surface-side channels 9a to 9f is formed from a corresponding one of the spiral cooling tubes arranged on the outer surface of the burner tube 5 along the outer surface of the burner tube 5. Furthermore, the plurality of folded channels 8a to 8f are formed from a plurality of cooling tubes, each of which connects the plurality of cooling tubes forming the inner surface-side channels 6a to 6f to the plurality of cooling tubes forming the outer surface-side channels 9a to 9f.

[0056] As part of the Fig. In the configuration shown in Fig. 10, the burner tube 5 (5E), the cooling tubes forming the inner surface side channels 6a to 6f respectively, the cooling tubes forming the folded channels 8a to 8f respectively, and the cooling tubes forming the outer surface side channels 9a to 9f respectively form a cooling channel structure 100E.

[0057] Also with the help of Fig. 10, it is possible to uniformly cool the burner tube 5 while preventing an increase in the pressure loss of the cooling medium, and it is possible to provide the burner tube 5 such that the cooling medium can enter and exit from one side (the proximal end side) of the burner tube 5.

[0058] Furthermore, the Fig. 2, Fig. 3, Fig. 8, Fig. 9 and the like, can be configured such that a channel cross-sectional area S and a headpiece diameter R (channel diameter) of the headpiece 12 increase with increasing distance from the inlet 14 for the cooling medium in the burner tube 5, as for example in Fig. 11 is shown.

[0059] Consequently, when the channel cross-sectional area S in the header 12 is increased, the flow velocity decreases compared to a case in which the channel cross-sectional area S and the header diameter R of the header 12, as in Fig. 12, are constant, making it possible to prevent a decrease in static pressure (a thrust of the cooling medium) at a position remote from the inlet 14 in the header 12. Consequently, it is possible to evenly distribute the cooling medium by means of the inner surface-side channels 6 (6a to 6f).

[0060] Furthermore, in the above-described burner tubes 5 (5A to 5E), a configuration example was described in which the cooling medium flows sequentially through the inner surface side channels 6, the folded channels 8, and the outer surface side channels 9. However, the flow direction of the cooling medium may also be opposite within the scope of the above-described configuration. This means that in the burner tubes 5 (5A to 5E), the cooling medium can flow sequentially through the outer surface side channels 9, the folded channels 8, and the inner surface side channels 6.

[0061] For example, in Fig. 13, in this case, the head piece 22 is connected to the inlet 14 for the cooling medium in the burner tube 5, and the head piece 12 is connected to the outlet 16 for the cooling medium in the burner tube 5. Furthermore, in this case, the head piece 22 can be configured such that a channel cross-sectional area and a head piece diameter of the head piece 12 increase with increasing distance from the inlet 14 for the cooling medium in the burner tube 5.

[0062] In the Fig. 13, the cooling channels through which the cooling medium flows to cool the burner tube 5 (5F) are formed in the inner portion of the burner tube 5 (5F) itself (the thick inner portion of the burner tube 5), the burner tube 5 (5F) as such forming a cooling channel structure 100F.

[0063] Furthermore, in some of the embodiments described above, those cases were exemplified in which the burner tubes 5 (5A to 5F) themselves each form the cooling channel structures. The same cooling channel structure as the cooling channel structures described above can also be applied to a nozzle skirt of a rocket engine.

[0064] Fig. 14 is a partial cross-sectional view showing the schematic structure of a nozzle skirt 32 of a rocket engine according to another embodiment.

[0065] The nozzle skirt 32 of the Fig. 14 is a tubular member with both ends open, and in an inner portion of the nozzle skirt 32 (a thick inner portion of the nozzle skirt 32), a plurality of spiral inner surface side channels 6a to 6f located on an inner surface side of the nozzle skirt 32, a plurality of spiral outer surface side channels 9a to 9f located on an outer surface side of the nozzle skirt 32, and a plurality of folded channels 8a to 8f each connecting the plurality of inner surface side channels 6a to 6f and the plurality of outer surface side channels 9a to 9f on a distal end side (one end side) of the nozzle skirt are arranged as cooling channels for flowing / guiding the cooling medium.In the illustrated form, each of the spiral inner surface side channels 6a to 6f is configured such that its radius increases toward the distal end side of the nozzle skirt 32. Furthermore, each of the spiral outer surface side channels 9a to 9f is configured such that its radius increases toward the distal end side of the nozzle skirt 32.

[0066] At the Fig. 14, the cooling channels through which the cooling medium flows to cool the nozzle skirt 32 are formed in the inner portion of the nozzle skirt 32 itself (the thick inner portion of the nozzle skirt 32), the nozzle skirt 32 as such forming a cooling channel structure 100G.

[0067] Also, by using the configuration described above, it is possible to uniformly cool the nozzle skirt 32 while preventing an increase in the pressure loss of the cooling medium, and it is possible to provide the nozzle skirt 32 such that the cooling medium can enter and exit from one side (the proximal end side) of the burner tube 5.

[0068] The contents described in the above embodiments are to be understood, for example, as follows.

[0069] (1) A cooling channel structure (such as the above-described cooling channel structures 100A to 100G) according to the present disclosure includes a tubular member (such as the above-described burner tube 5 (5A to 5E) or the nozzle skirt 32) having openings at both ends. In an inner portion or on a surface of the tubular member, a plurality of spiral outer surface side channels (such as the above-described outer surface side channels 9a to 9f) located on an outer surface side of the tubular member, at least one inner surface side channel (such as the above-described inner surface side channels 6a to 6f) located on an inner surface side of the tubular member, and a plurality of folded channels (such asthe above-described folded channels 8a to 8f) which respectively connect the plurality of outer surface side channels and the at least one inner surface side channel at one end side of the tubular member, are provided as cooling channels for flowing / guiding a cooling medium for cooling the tubular member, wherein at least one of the outer surface side channels and the inner surface side channel includes a portion (such as the above-described channel portion 18 and channel portion 20) in which a channel cross-sectional area changes depending on an axial position on the tubular member.

[0070] Since the plurality of spiral outer surface side channels are arranged on the outer surface side of the tubular member, by using the cooling channel structure according to the above-described configuration (1), it is possible to prevent uneven cooling of the tubular member and to cool the tubular member uniformly, compared with a case where only the cooling channels along the axial direction are used for cooling the tubular member.

[0071] Furthermore, compared to a case where only a single spiral outer surface side channel is arranged on the outer surface side of the tubular member, it is possible to reduce the channel length required for each spiral outer surface side channel to cover the same area, thereby preventing an increase in pressure loss and reducing a driving force for supplying the cooling medium. Consequently, it is possible to effectively cool the tubular member using a driving source such as a pump or a fan with a low driving force.

[0072] In addition, since the plurality of inner surface side channels and the plurality of outer surface side channels are each connected to each other via the plurality of folded channels at one end side of the tubular member, it is possible to combine the inlet and the outlets for the cooling medium in the tubular member at another end side of the tubular member.

[0073] Accordingly, it is possible to provide a cooling channel structure in which the tubular member is uniformly cooled while preventing an increase in the pressure loss of the cooling medium, and the cooling medium can flow in and out from one side of the tubular member. Furthermore, since the channel cross-sectional area of ​​at least one of the outer surface side channels and the inner surface side channel in the above-described portion changes depending on the heat load distribution in the tubular member, it is possible to effectively reduce the thermal stress induced in the tubular member.

[0074] (2) In some embodiments, in the cooling channel structure according to the above-described configuration (1), the plurality of outer surface side channels, the at least one inner surface side channel, and the plurality of folded channels are arranged in an inner portion or on a surface of the tubular member.

[0075] As for the configuration (2) described above, the plurality of outer surface side channels, the at least one inner surface side channel, and the plurality of folded channels may be arranged in the inner portion of the tubular member (in the tubular member itself), or may be arranged on the surface of the tubular member (as components separate from the tubular member).

[0076] (3) In some embodiments, the cooling channel structure according to the above-described configuration (1) or (2) includes an inlet for the cooling medium arranged at another end side of the tubular member and an outlet for the cooling medium arranged at the other end side of the tubular member.

[0077] Since the inlet and outlet for the cooling medium are combined on the other end side of the tubular member, by using the cooling channel structure according to the configuration (3) described above, it is possible to provide a cooling channel structure in which the tubular member is uniformly cooled, at the same time, an increase in the pressure loss of the cooling medium is prevented, and the cooling medium can enter and exit from one side of the tubular member.

[0078] (4) In some embodiments, in the cooling channel structure according to any one of the above-described configurations (1) to (3), a plurality of inner surface side channels located on the inner surface side of the tubular member are arranged in an inner portion or on a surface of the tubular member, and each of the plurality of inner surface side channels is formed in a spiral shape.

[0079] By using the cooling channel structure according to the configuration (4) described above, it is possible to provide a cooling channel structure in which the tubular member is cooled more uniformly and the cooling medium can enter and exit from one side in the axial direction.

[0080] (5) In some embodiments, in the cooling passage structure according to the above-described configuration (4), the folded passages are curved such that a direction in which the outer surface side passages circulate to a downstream side along a spiral and a direction in which the inner surface side passages circulate to the downstream side along the spiral are opposite to each other.

[0081] By using the cooling channel structure according to the configuration (5) described above, it is possible to reduce thermal stress caused in the folded channels.

[0082] (6) In some embodiments, in the cooling passage structure according to the above-described configuration (4), the folded passages are curved such that a direction in which the outer surface side passages circulate to a downstream side along a spiral and a direction in which the inner surface side passages circulate to the downstream side along the spiral are identical.

[0083] By using the cooling channel structure according to the configuration (6) described above, it is possible to smoothly reverse a flow direction of the cooling medium in the axial direction by means of the folded channels and prevent an increase in pressure loss.

[0084] (7) In some embodiments, in the cooling passage structure according to any one of the above-described configurations (1) to (3), a plurality of inner surface side passages located on the inner surface side of the tubular member are arranged in an inner portion or on a surface of the tubular member, and each of the plurality of inner surface side passages extends linearly along an axial direction of the tubular member.

[0085] By using the cooling passage structure according to the configuration (7) described above, it is possible to reduce the pressure loss by reducing the passage length of the inner surface side passage, as compared with a case where each of the inner surface side passages is formed in a spiral shape.

[0086] (8) In some embodiments, the cooling channel structure according to any one of the above-described configurations (4) to (7) further comprises a header (such as the above-described header 12) that connects end portions of the plurality of inner surface side channels to each other at another end side of the tubular member.

[0087] By using the cooling channel structure according to the configuration (8) described above, there is no need to connect each of the inner surface side channels to the external cooling medium pipe individually, whereby it is possible to simplify the process of connecting each inner surface side channel to the external cooling medium pipe.

[0088] (9) In some embodiments, the cooling channel structure according to any one of the above-described configurations (1) to (7) further comprises a header (such as the above-described header 22) that connects end portions of the plurality of outer surface side channels to each other at another end side of the tubular member.

[0089] By using the cooling channel structure according to the configuration (9) described above, there is no need to connect each of the outer surface side channels to the external cooling medium pipe one by one, whereby it is possible to simplify the process of connecting each outer surface side channel to the external cooling medium pipe.

[0090] (10) In some embodiments, in the cooling channel structure according to the above-described configuration (8) or (9), the header is connected to an inlet for the cooling medium in the tubular member, and the header has a channel cross-sectional area which increases with increasing distance from the inlet.

[0091] With the cooling channel structure according to the configuration (10) described above, when the channel cross-sectional area in the header is increased, the flow velocity decreases compared to a case where the channel cross-sectional area of ​​the header is constant, thereby preventing a decrease in static pressure (a thrust of the cooling medium) at a position in the header remote from the inlet. Consequently, it is possible to evenly distribute the cooling medium using the plurality of inner surface-side channels.

[0092] (11) In some embodiments, in the cooling channel structure according to the above-described configuration (1), at least one of the outer surface side channels and the inner surface side channel includes a portion (such as the above-described channel portion 18 and channel portion 20) in which the channel cross-sectional area decreases toward the folded channels.

[0093] In this case, only the outer surface side channels from the group of the outer surface side channels and the inner surface side channel may include the section in which the channel cross-sectional area decreases toward the folded channels, only the inner surface side channel from the group of the outer surface side channels and the inner surface side channel may include the section in which the channel cross-sectional area decreases toward the folded channels, or the outer surface side channels and the inner surface side channel may each include the section in which the channel cross-sectional area decreases toward the folded channels.

[0094] By means of the cooling channel structure according to the above-described configuration (11), in a case where the ambient temperature increases as the tubular member approaches one end side (such as in the case where the tubular member is the burner tube or the like), it is possible to effectively cool the tubular member by increasing the flow velocity of the cooling medium in a region where the ambient temperature in the above-described portion tends to be high, and to effectively reduce the thermal stress induced in the tubular member.

[0095] (12) A cooling channel structure (such as the above-described cooling channel structures 100A to 100G) according to the present disclosure includes a tubular member (such as the above-described burner tube 5 (5A to 5E) or the nozzle skirt 32) having openings at both ends. In an inner portion or on a surface of the tubular member, as cooling channels for flowing / guiding a cooling medium for cooling the tubular member, there are provided: a plurality of spiral outer surface side channels (such as the above-described outer surface side channels 9a to 9f) located on an outer surface side of the tubular member, at least one inner surface side channel (such as the above-described inner surface side channels 6a to 6f) located on an inner surface side of the tubular member, and a plurality of folded channels (such asthe above-described folded channels 8a to 8f) each connecting the plurality of outer surface side channels and the at least one inner surface side channel at one end side of the tubular member, wherein at least one of the outer surface side channels and the inner surface side channel has a portion (such as the above-described channel portion 18 and channel portion 20) in which a cross-sectional shape changes depending on an axial position on the tubular member.

[0096] In this case, only the outer surface side channels from the group of the outer surface side channels and the inner surface side channel may include the portion in which the cross-sectional shape changes depending on the axial position on the tubular member, only the inner surface side channel from the group of the outer surface side channels and the inner surface side channel may include the portion in which the cross-sectional shape changes depending on the axial position on the tubular member, or the outer surface side channels and the inner surface side channel may each include the portion in which the cross-sectional shape changes depending on the axial position on the tubular member.Since the cross-sectional shape of at least one of the outer surface side channels and the inner surface side channel in the above-described portion changes depending on the distribution of the heat load in the tubular member, by using the cooling channel structure according to the above-described configuration (12), it is possible to effectively reduce the thermal stress induced in the tubular member.

[0097] (13) A burner according to the present disclosure includes the cooling channel structure according to any one of the configurations (1) to (12) described above.

[0098] Since the burner according to the above-described configuration (13) includes the cooling channel structure according to any one of the above-described configurations (1) to (12), it is possible to prevent uneven cooling of the tubular member (burner tube) and to cool the tubular member uniformly.

[0099] Furthermore, compared to a case where only a single spiral outer surface side channel is arranged on the outer surface side of the tubular member, it is possible to reduce the channel length required for each spiral outer surface side channel to cover the same area, thereby preventing an increase in pressure loss and reducing a driving force for supplying the cooling medium. Consequently, it is possible to effectively cool the tubular member using a driving source such as a pump or a fan with a low driving force.

[0100] In addition, since the plurality of inner surface side channels and the plurality of outer surface side channels are each connected to each other via the plurality of folded channels at one end side of the tubular member, it is possible to combine the inlet and the outlets for the cooling medium in the tubular member at another end side of the tubular member. List of reference symbols 2 burners 4 Fuel nozzle 5 (5A-5E) Burner tube 6a-6f inner surface channel 8a-8f folded channel 9a-9f external surface channel 12 headpiece 14 Entrance 16 Outlet 18 canal section 20 canal section 22 headpiece 24 Air supply pipe 26 Combustion chamber 28 Wall 30 swirling device 32 Nozzle skirt 100A-100G cooling channel structure

Claims

[1] A cooling channel structure (100A-100G) comprising: a tubular element (5, 32) with openings at both ends, wherein the cooling channel structure (100A-100G), as cooling channels for flowing / conducting a cooling medium for cooling the tubular element (5, 32), comprises: a plurality of spiral outer surface side channels (9a-9f) located on an outer surface side of the tubular element (5, 32), at least one inner surface side channel (6a-6f) located on an inner surface side of the tubular element (5, 32), and a plurality of folded channels (8a-8f) each connecting the plurality of outer surface side channels (9a-9f) and the at least one inner surface side channel (6a-6f) at one end side of the tubular element (5, 32), wherein at least one of the outer surface side channels (9a-9f) and the inner surface side channel (6a-6f) comprises a portion (18, 20) in which a channel cross-sectional area changes depending on an axial position on the tubular element (5, 32). [2] The cooling channel structure (100A-100G) according to claim 1, wherein the plurality of outer surface side channels (9a-9f), the at least one inner surface side channel (6a-6f) and the plurality of folded channels (8a-8f) are arranged in an inner portion or on a surface of the tubular member (5, 32). [3] The cooling channel structure (100A-100G) according to claim 1 or 2, comprising: an inlet (14) for the cooling medium, which is arranged at another end side of the tubular element (5, 32), and an outlet (16) for the cooling medium, which is arranged at the other end side of the tubular element (5, 32). [4] The cooling channel structure (100A-100G) according to one of claims 1 to 3, wherein a plurality of inner surface side channels (6a-6f) located on the inner surface side of the tubular element (5, 32) are arranged in an inner portion or on a surface of the tubular element (5, 32), and wherein each of the plurality of inner surface side channels (6a-6f) is formed spirally. [5] The cooling passage structure (100A-100G) according to claim 4, wherein the folded passages (8a-8f) are curved such that a direction in which the outer surface side passages (9a-9f) revolve to a downstream side along a spiral and a direction in which the inner surface side passages (6a-6f) revolve to the downstream side along the spiral are opposite to each other. [6] The cooling channel structure (100A-100G) according to claim 4, wherein the folded channels (8a-8f) are curved such that a direction in which the outer surface side channels (9a-9f) revolve to a downstream side along a spiral and a direction in which the inner surface side channels (6a-6f) revolve to the downstream side along the spiral are identical. [7] The cooling channel structure (100A-100G) according to one of claims 1 to 3, wherein a plurality of inner surface side channels (6a-6f) located on the inner surface side of the tubular element (5, 32) are arranged in an inner portion or on a surface of the tubular element (5, 32), and wherein each of the plurality of inner surface side channels (6a-6f) extends linearly along an axial direction of the tubular member (5, 32). [8] The cooling channel structure (100A-100G) according to any one of claims 4 to 7, further comprising: a header (22) connecting end portions of the plurality of inner surface side channels (6a-6f) at another end side of the tubular member (5, 32). [9] The cooling channel structure (100A-100G) according to any one of claims 1 to 7, further comprising: a header (22) connecting end portions of the plurality of outer surface side channels (9a-9f) at another end side of the tubular member (5, 32). [10] The cooling channel structure (100A-100G) according to one of claims 8 or 9, wherein the head piece (22) is connected to an inlet (14) for the cooling medium in the tubular element (5, 32), and wherein the head piece (22) has a channel cross-sectional area which increases with increasing distance from the inlet (14). [11] The cooling channel structure (100A-100G) according to claim 1, wherein at least one of the outer surface side channels (9a-9f) and the inner surface side channel (6a-6f) includes a portion in which the channel cross-sectional area decreases toward the folded channels (8a-8f). [12] A cooling channel structure (100A-100G) comprising: a tubular element (5, 32) with openings at both ends, wherein the cooling channel structure (100A-100G), as cooling channels for flowing / conducting a cooling medium for cooling the tubular element (5, 32), comprises: a plurality of spiral outer surface side channels (9a-9f) located on an outer surface side of the tubular element (5, 32), at least one inner surface side channel (6a-6f) located on an inner surface side of the tubular element (5, 32), and a plurality of folded channels (8a-8f) each connecting the plurality of outer surface side channels (9a-9f) and the at least one inner surface side channel (6a-6f) at one end side of the tubular element (5, 32), wherein at least one of the outer surface side channels (9a-9f) and the inner surface side channel (6a-6f) includes a portion in which a cross-sectional shape changes depending on an axial position on the tubular member (5, 32). [13] A burner (2) comprising the cooling channel structure (100A-100G) according to any one of claims 1 to 12.

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