COOLING CHANNEL STRUCTURE, BURNER, AND HEAT EXCHANGER

Provided are a first wall section extending along a first direction, a second wall section disposed at an interval from the first wall section in a second direction orthogonal to the first direction, and a plurality of partition wall sections connecting the first wall section and the second wall section so as to form at least one cooling channel between the first wall section and the second wall section, the cooling channel having a plurality of channel cross-sections disposed at intervals in the first direction. In a cross-section including the first direction and the second direction, at least a part of each of the partition wall sections extends along a direction intersecting with the second direction.

TECHNICAL FIELD

The present disclosure relates to a cooling channel structure, a burner, and a heat exchanger.

BACKGROUND

Patent Document 1 discloses a fuel nozzle shroud which internally includes a cooling channel linearly extending along the axial direction. With the above configuration, by flowing a cooling medium to the cooling channel, it is possible to reduce a thermal stress caused in the fuel nozzle shroud.

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

Meanwhile, regarding a cooling channel for cooling an object to be cooled, if a plurality of channel cross-sections are disposed at intervals between two wall sections facing each other in a direction along wall surfaces, in the wall section of the above-described two wall sections exposed to a high-temperature fluid, a large thermal stress is caused at a connection position with a partition wall section partitioning the above-described plurality of channel cross-sections, which may cause damage. However, Patent Document 1 described above does not disclose any knowledge for the above problem and a solution thereto.

In view of the above, an object of the present disclosure is to provide a cooling channel structure, a burner, and a heat exchanger capable of suppressing damage caused by the thermal stress.

Solution to Problem

In order to achieve the above object, a cooling channel structure according to the present disclosure includes a first wall section extending along a first direction, a second wall section disposed at an interval from the first wall section in a second direction orthogonal to the first direction, and a plurality of partition wall sections connecting the first wall section and the second wall section so as to form at least one cooling channel between the first wall section and the second wall section, the cooling channel having a plurality of channel cross-sections disposed at intervals in the first direction. In a cross-section including the first direction and the second direction, at least a part of each of the partition wall sections extends along a direction intersecting with the second direction.

Advantageous Effects

According to the present disclosure, provided are a cooling channel structure, a burner, and a heat exchanger capable of suppressing damage caused by a thermal stress.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. It is intended, however, that unless particularly identified, dimensions, materials, shapes, relative positions and the like of components described or shown in the drawings as the embodiments shall be interpreted as illustrative only and not intended to limit the scope of the present invention.

Further, for instance, an expression of a shape such as a rectangular shape or a tubular shape shall not be construed as only the geometrically strict shape, but also includes a shape with unevenness or chamfered corners within the range in which the same effect can be achieved.

On the other hand, the expressions “comprising”, “including”, “having”, “containing”, and “constituting” one constituent component are not exclusive expressions that exclude the presence of other constituent components.

FIG. 1is a vertical cross-sectional view showing the schematic configuration of a burner2according to an embodiment. The burner2is applied to, for example, a gasification furnace for a coal gasification device or the like, a conventional boiler, an incinerator, a gas turbine combustor, or an engine.

The burner2includes a fuel nozzle4for injecting fuel, and a burner tube5Disposed around the fuel nozzle4on the same axis CL as the fuel nozzle4, for guiding air serving as an oxidant for combusting the fuel. The burner tube5is a tubular member having openings at both ends, respectively, and functions as a shield tube for shielding heat. A swirler30is disposed between the outer peripheral surface of the fuel nozzle4and the inner peripheral surface of the burner tube5. The burner tube5is disposed to penetrate a wall28of a combustion chamber26where flame is formed. The proximal end side of the burner tube5is located outside the combustion chamber26, and the distal end side of the burner tube5is located inside the combustion chamber26. On the proximal end side of the burner tube5, for example, a flange or the like may be provided which is to be connected to an air supply pipe (not shown) for supplying air.

Hereinafter, the axial direction of the burner tube5will simply be referred to as the “axial direction”, the radial direction of the burner tube5will simply be referred to as the “radial direction”, and the circumferential direction of the burner tube5will simply be referred to as the “circumferential direction”. Further, hereinafter, an inner portion of the burner tube5means a thick inner portion of the burner tube5.

Next, a configuration example of the burner tube5will be described with reference toFIG. 2.FIG. 2is a vertical cross-sectional view showing the schematic configuration of a burner tube5(5A) according to an embodiment, and shows a cross-section including the center axis CL (a cross-section including the axial direction and the radial direction) of the burner tube5(5A).

As shown inFIG. 2, the burner tube5(5A) includes a tubular first wall section6extending along the axial direction serving as the first direction, a tubular second wall section8disposed at an interval from the first wall section6in the radial direction (a thickness direction of the burner tube5) serving as the second direction orthogonal to the first direction, at least one cooling channel14, and a plurality of partition wall sections10connecting the first wall section6and the second wall section8. The tubular second wall section8is disposed on the inner peripheral side of the tubular first wall section6, and the center axis CL of the first wall section6coincides with a center axis of the second wall section8. In the cross-section shown inFIG. 2, the first wall section6and the second wall section8are disposed parallel to each other.

The plurality of partition wall sections10connect the first wall section6and the second wall section8so as to form the at least one cooling channel14, which has a plurality of channel cross-sections12disposed at intervals in the axial direction, between the first wall section6and the second wall section8. That is, each of the partition wall sections10is disposed in the cooling channel14, extends from the first wall section6to the second wall section8along the radial direction, and forms a wall surface of the cooling channel14. Each of the partition wall sections10has a radially outer end connected to a surface6aof the first wall section6on the side of the second wall section8(the inner peripheral surface of the first wall section6). Each of the partition wall sections10has a radially inner end connected to a surface8aof the second wall section8on the side of the first wall section6(the outer peripheral surface of the second wall section8). That is, the first wall section and the second wall section8are connected via the plurality of partition wall sections10. The at least one cooling channel14may be, for example, one spiral channel, a plurality of spiral channels, or one or a plurality of channels with various other shapes adopted for a heat exchanger and the like.

In the cross-section shown inFIG. 2, at least a part of each partition wall section10extends along a direction intersecting with the radial direction. In the cross-section shown inFIG. 2, each of the channel cross-sections12has an arrow shape including a substantially triangle, and each of the partition wall sections10includes a first inclined wall portion16linearly extending from the first wall section6along a direction a (third direction) intersecting with the radial direction, and a second inclined wall portion18linearly extending from the second wall section8along a direction b (fourth direction) intersecting with each of the radial direction and the direction a to be connected to the first inclined wall portion16. In the illustrated cross-section, the direction a is a direction toward the distal end side of the burner tube5in the axial direction from the first wall section6toward the radially inner side, and the direction b is a direction toward the distal end side of the burner tube5in the axial direction from the second wall section8toward the radially outer side.

In the configuration shown inFIG. 2, the first wall section6, the second wall section8, and the plurality of partition wall sections10constitute a cooling channel structure100A including the at least one cooling channel14. That is, the at least one cooling channel14, through which a cooling medium for cooling the burner tube5(5A) flows, is formed in the inner portion of the burner tube5(5A) itself (the thick inner portion of the burner tube5), and the burner tube5(5A) itself constitutes the cooling channel structure100A. Such burner tube5(5A) can be produced by using, for example, a three-dimensional additive manufacturing device (so-called 3D printer). The cooling medium flowing through the cooling channel14may be, for example, a liquid such as water or oil, or a gas such as air.

Herein, an effect obtained by the configuration shown inFIG. 2will be described with reference toFIGS. 3 to 5.FIG. 3is a vertical cross-sectional view showing the schematic configuration of the burner tube according to a comparative embodiment.FIG. 4is a partially enlarged view of the configuration shown inFIG. 3.FIG. 4schematically shows a thermal deformation amount of a first wall section06in the radial direction by a dashed line with regard to a virtual case (case1) where the first wall section06receives no constraint of thermal deformation from partition wall sections010, and schematically shows a thermal deformation amount of the first wall section06in the radial direction by a single-dotted chain line with regard to an actual case (case2) where the first wall section06receives the constraint of thermal deformation from the partition wall sections010.FIG. 5is a partially enlarged view of the configuration shown inFIG. 2.FIG. 5schematically shows a thermal deformation amount of a first wall section6in the radial direction by a dashed line with regard to a virtual case (case3) where the first wall section6receives no constraint of thermal deformation by partition wall sections10, and schematically shows a thermal deformation amount of the first wall section6in the radial direction by a single-dotted chain line with regard to an actual case (case4) where the first wall section6receives the constraint of thermal deformation by the partition wall sections10.

As shown inFIG. 3, in a device for performing heat exchange, in the first wall section06located between the high-temperature fluid and the cooling medium (a low-temperature fluid having a lower temperature than the high-temperature fluid), a temperature gradient (a temperature gradient with a temperature distribution ranging from a temperature T2to a temperature T1shown inFIG. 3) is generated in the thickness direction of the first wall section06, and thermal deformation is caused by a temperature increase due to a heat flux q from the high-temperature fluid. Meanwhile, the partition wall sections010, respectively, partitioning channel cross-sections012of a cooling channel014are interposed between the cooling media, the temperature of the partition wall sections010is the same as that of the cooling media.

As shown inFIG. 4, the first wall section06is not connected to the partition wall section010at a position P2away from the partition wall section010in the axial direction, and thus does not directly receive no constraint of thermal deformation from the partition wall section010at the position P2, whereas the first wall section06is connected to the partition wall section010at a position P1where the partition wall section010exists in the axial direction, and thus directly receives the constraint of thermal deformation from the partition wall section010at the position P1. Thus, a large thermal stress is caused in a portion of the first wall section06connected to the partition wall section010(a portion in the vicinity of the position P1), which may cause damage.

By contrast, in the burner tube5(5A) shown inFIGS. 2 and 5, as described above, at least the part of each partition wall section10extends along the direction intersecting with the radial direction. Thus, compared with the respective configurations shown inFIGS. 3 and 4, it is possible to suppress the damage to the first wall section6by reducing a constraint force of thermal deformation received from the partition wall section10by the first wall section6(the constraint force received by the portion of the first wall section6connected to the partition wall section10), while maintaining the density of the cooling channel14.

Further, as described above, each of the partition wall sections10includes the first inclined wall portion16extending from the first wall section6along the direction a intersecting with the radial direction, and the second inclined wall portion18extending from the second wall section8along the direction b intersecting with each of the radial direction and the direction a to be connected to the first inclined wall portion16. Thus, each of the channel cross-sections12has the arrow shape including the substantially triangle, implementing high pressure resistance and low pressure loss of the cooling channel14, as well as making it possible to suppress an increase in thermal stress caused in the first wall section6.

Next, some other embodiments will be described. In other embodiments to be described below, unless otherwise stated, common reference characters with those for the respective constituent components in the aforementioned embodiments denote the same constituent components as those for the respective constituent components in the aforementioned embodiments, and the description thereof will be omitted.

FIG. 6is a vertical cross-sectional view showing the schematic configuration of a burner tube5(5B) according to another embodiment, and shows a cross-section including the center axis CL (the cross-section including the axial direction and the radial direction) of the burner tube5(5B).FIG. 7is a vertical cross-sectional view showing the schematic configuration of a burner tube5(5C) according to another embodiment, and shows a cross-section including the center axis CL (the cross-section including the axial direction and the radial direction) of the burner tube5(5C).

The burner tube5(5B) shown inFIG. 6further includes a third wall section20and a plurality of partition wall sections22, in addition to the first wall section6, the second wall section8, and the plurality of partition wall sections10described above.

The third wall section20is disposed opposite to the first wall section6across the second wall section8, and extends along the axial direction. In the configuration shown inFIG. 6, a surface6bof the first wall section6on a side opposite to the second wall section8faces a high-temperature fluid in the combustion chamber26, and a surface20aof the third wall section20on the side opposite to the second wall section8faces the high-temperature fluid in the combustion chamber26.

The plurality of partition wall sections22connect the second wall section8and the third wall section20so as to form the at least one cooling channel34, which has a plurality of channel cross-sections32disposed at intervals in the axial direction, between the second wall section8and the third wall section20.

In the cross-section shown inFIG. 6, at least a part of each partition wall section22connecting the second wall section8and the third wall section20extends along the direction intersecting with the radial direction. In the cross-section shown inFIG. 6, each of the partition wall sections22includes a third inclined wall portion36linearly extending from the second wall section8along a direction c intersecting with the radial direction, and a fourth inclined wall portion38linearly extending from the second wall section8along a direction d intersecting with each of the radial direction and the direction c to be connected to the third inclined wall portion36. In the illustrated cross-section, the direction c is a direction toward the distal end side of the burner tube5in the axial direction from the second wall section8toward the radially inner side, and the direction d is a direction toward the distal end side of the burner tube5in the axial direction from the third wall section20toward the radially outer side.

In the configuration shown inFIG. 6, the first wall section6, the second wall section8, the third wall section20, the plurality of partition wall sections10, and the plurality of partition wall sections22constitute a cooling channel structure100B including the cooling channels14,34. That is, the cooling channels14and34, through which the cooling medium for cooling the burner tube5(5B) flows, are formed in the inner portion of the burner tube5(5B) itself (the thick inner portion of the burner tube5), and the burner tube5(5B) itself constitutes the cooling channel structure100B.

With the configuration shown inFIG. 6, since at least the part of each partition wall section10connecting the first wall section6and the second wall section8extends along the direction intersecting with the radial direction, it is possible to suppress the damage to the first wall section6by reducing the constraint force of the thermal deformation received from the partition wall section10by the first wall section6, while maintaining the density of the cooling channel24. Further, since at least the part of each partition wall section22connecting the second wall section8and the third wall section20extends along the direction intersecting with the radial direction, it is possible to suppress damage to the third wall section20by reducing a constraint force of thermal deformation received from the partition wall section22by the third wall section20, while maintaining the density of the cooling channel34.

In the configuration shown inFIG. 6, the first wall section6and the third wall section20are heated by the high-temperature fluid and thermal deformation (thermal expansion) is caused in the axial direction, whereas the second wall section8is interposed between the cooling media and cooled, constraining the axial thermal deformation of the first wall section6and the third wall section20by the second wall section8, and causing the thermal stress.

By contrast, in the burner tube5(5C) shown inFIG. 7, in the cross-section including the axial direction and the radial direction, at least a part of the second wall section8extends along the direction intersecting with the axial direction. Thus, the constraint force of the axial thermal deformation received from the second wall section8by the first wall section6and the third wall section20is reduced, making it possible to suppress the damage to the first wall section6and the third wall section20.

Further, in the cross-section shown inFIG. 7, the second wall section8includes, at the same pitch as the partition wall sections10, a plurality of connecting portions40, and a plurality of bent wall portions48each including a fifth inclined wall portion42, a sixth inclined wall portion44, and a seventh inclined wall portion46. The connecting portions40are connected to the partition wall sections10and the partition wall sections22, respectively.

The fifth inclined wall portion42linearly extends toward the radially outer side toward the proximal end side of the burner tube5in the axial direction. One end of the fifth inclined wall portion42is connected to the connecting portion40, and another end of the fifth inclined wall portion42is connected to one end of the sixth inclined wall portion44. The sixth inclined wall portion44linearly extends toward the radially inner side toward the proximal end side of the burner tube5in the axial direction, and another end of the sixth inclined wall portion44is connected to one end of the seventh inclined wall portion46. The seventh inclined wall portion46linearly extends toward the radially outer side toward the proximal end side of the burner tube5in the axial direction, and another end of the seventh inclined wall portion46is connected to the adjacent connecting portion40.

In the configuration shown inFIG. 7, the first wall section6, the second wall section8, the third wall section20, the plurality of partition wall sections10, and the plurality of partition wall sections22constitute a cooling channel structure100C including the cooling channels14,34. That is, the cooling channels14and34, through which the cooling medium for cooling the burner tube5(5C) flows, are formed in the inner portion of the burner tube5(5C) itself (the thick inner portion of the burner tube5), and the burner tube5(5C) itself constitutes the cooling channel structure100C.

In the configuration shown inFIG. 7, since the second wall section8includes the above-described bent wall portions48, it is possible to effectively reduce the constraint force of the axial thermal deformation received from the second wall section8by the first wall section6and the third wall section20.

FIG. 8is a partially enlarged view of the configuration shown inFIG. 6.FIG. 8schematically shows a thermal deformation amount in the axial direction by a dashed line with regard to a virtual case (case5) where thermal deformation is not constrained, and schematically shows a thermal deformation amount in the axial direction by a single-dotted chain line with regard to an actual case (case6) where thermal deformation is constrained.FIG. 9is a partially enlarged view of the configuration shown inFIG. 7.FIG. 9schematically shows a thermal deformation amount in the axial direction by a dashed line with regard to a virtual case (case7) where thermal deformation is not constrained, and schematically shows a thermal deformation amount in the axial direction by a single-dotted chain line with regard to an actual case (case8) where thermal deformation is constrained.

ComparingFIGS. 8 and 9, compared with the virtual case (case5, case7) where thermal deformation is not constrained, the thermal deformation amount of the first wall section6and the third wall section20are constrained and reduced in the actual case (case6, case8) where thermal deformation is constrained. Further, the constraint force of the axial thermal deformation received from the second wall section8by the first wall section6and the third wall section20is smaller in the configuration shown inFIG. 9than in the configuration shown inFIG. 8, compared with case6shown inFIG. 8, the axial thermal deformation amount of the first wall section6, the second wall section8, and the third wall section20is large in case8. Thus, it is possible to further reduce the thermal stress caused in the first wall section6and the third wall section20in the configuration shown inFIG. 9than in the configuration shown inFIG. 8, and to suppress the damage to the first wall section6and the third wall section20.

FIG. 10is a vertical cross-sectional view showing the schematic configuration of a burner tube5(5D) according to another embodiment, and shows a cross-section including the center axis CL (the cross-section including the axial direction and the radial direction) of the burner tube5(5D).

Each of the channel cross-sections12,32has the arrow shape including the substantially triangle in the configuration shown inFIG. 6, whereas each of the channel cross-sections12,32has the arrow shape including a substantially semicircle in the configuration shown inFIG. 10.

In the cross-section shown inFIG. 10, each of the partition wall sections10is formed along an arc, and at least the part of the partition wall section10extends along the direction intersecting with the radial direction. Further, in the cross-section shown inFIG. 10, each of the partition wall sections22is formed along an arc, and at least the part of the partition wall section22extends along the direction intersecting with the radial direction.

Thus, in the configuration shown inFIG. 10, the first wall section6, the second wall section8, the third wall section20, the plurality of partition wall sections10, and the plurality of partition wall sections22constitute a cooling channel structure100D including the cooling channels14,34. That is, the cooling channels14and34, through which the cooling medium for cooling the burner tube5(5D) flows, are formed in the inner portion of the burner tube5(5D) itself (the thick inner portion of the burner tube5), and the burner tube5(5D) itself constitutes the cooling channel structure100D.

In the configuration shown inFIG. 10as well, since at least the part of each partition wall section10extends along the direction intersecting with the radial direction, it is possible to suppress the damage to the first wall section6by reducing the constraint force of the thermal deformation received from the partition wall section10by the first wall section6, while maintaining the density of the cooling channel14. Further, since at least the part of each partition wall section22extends along the direction intersecting with the radial direction, it is possible to suppress damage to the third wall section20by reducing the constraint force of thermal deformation received from the partition wall section22by the third wall section20, while maintaining the density of the cooling channel34.

Further, forming each of the partition wall sections10along the arc, compared with the configuration shown inFIG. 6, it is possible to suppress an increase in pressure loss of the cooling channel14while increasing pressure resistance of the cooling channel14. Further, forming each of the partition wall sections22along the arc, compared with the configuration shown inFIG. 6, it is possible to suppress an increase in pressure loss of the cooling channel14while increasing pressure resistance of the cooling channel34.

FIG. 11is a vertical cross-sectional view showing the schematic configuration of a burner tube5(5E) according to another embodiment, and shows a cross-section including the center axis CL (the cross-section including the axial direction and the radial direction) of the burner tube5(5E).

Each of the channel cross-sections12,32has the arrow shape including the substantially triangle in the configuration shown inFIG. 6, whereas each of the channel cross-sections12,32has a substantially parallelogram in the configuration shown inFIG. 11.

In the cross-section shown inFIG. 11, each of the partition wall sections10linearly extends from the first wall section6to the second wall section8along a direction e intersecting with the radial direction. Further, in the cross-section shown inFIG. 11, each of the partition wall sections22linearly extends from the third wall section20to the second wall section8along a direction f intersecting with the radial direction. In the illustrated cross-section, the direction e is a direction toward the proximal end side of the burner tube5in the axial direction from the first wall section6toward the radially inner side, and the direction f is a direction toward the proximal end side of the burner tube5in the axial direction from the third wall section20toward the radially outer side.

Thus, in the configuration shown inFIG. 11, the first wall section6, the second wall section8, the third wall section20, the plurality of partition wall sections10, and the plurality of partition wall sections22constitute a cooling channel structure100C including the cooling channels14,34. That is, the cooling channels14and34, through which the cooling medium for cooling the burner tube5(5E) flows, are formed in the inner portion of the burner tube5(5E) itself (the thick inner portion of the burner tube5), and the burner tube5(5E) itself constitutes the cooling channel structure100E.

In the configuration shown inFIG. 11as well, since at least the part of each partition wall section10extends along the direction intersecting with the radial direction, it is possible to suppress the damage to the first wall section6by reducing the constraint force of the thermal deformation received from the partition wall section10by the first wall section6, while maintaining the density of the cooling channel14. Further, since at least the part of each partition wall section22extends along the direction intersecting with the radial direction, it is possible to suppress the damage to the third wall section20by reducing the constraint force of thermal deformation received from the partition wall section22by the third wall section20, while maintaining the density of the cooling channel34.

Further, since the partition wall sections10extend from the first wall section6to the second wall section8along the direction e intersecting with the radial direction, compared with the configuration shown inFIG. 6and the configuration shown inFIG. 10, it is possible to effectively suppress the damage to the first wall section6by effectively reducing the constraint force of thermal deformation received from the partition wall sections10by the first wall section6.

Further, since the partition wall sections22extend from the third wall section20to the second wall section8along the direction f intersecting with the radial direction, compared with the configuration shown inFIG. 6and the configuration shown inFIG. 10, it is possible to effectively suppress the damage to the third wall section20by effectively reducing the constraint force of thermal deformation received from the partition wall sections22by the third wall section20.

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 as appropriate.

For example, in some embodiments described above, the cases where the burner tubes5(5A to5E) constitute the cooling channel structures100A to100E, respectively, have been exemplified. The same cooling channel structure as the above cooling channel structures may be applied to a nozzle skirt of a rocket engine.

FIG. 12is a partial cross-sectional view showing the schematic configuration of a nozzle skirt50of a rocket engine according to another embodiment.

The nozzle skirt50of the rocket engine shown inFIG. 12is formed into a tubular shape and includes the tubular first wall section6extending along a first direction d1, the tubular second wall section8disposed at the interval from the first wall section6in a second direction d2(a thickness direction of the nozzle skirt50) orthogonal to the first direction d1, and the plurality of partition wall sections10connecting the first wall section6and the second wall section8. The tubular second wall section8is disposed on the inner peripheral side of the tubular first wall section6, and the center axis CL of the first wall section6coincides with the center axis CL of the second wall section8. The radius of the tubular first wall section6and the radius of the tubular second wall section8increase toward the distal end side (the lower side of the drawing) of the nozzle skirt50.

The plurality of partition wall sections10connect the first wall section6and the second wall section8so as to form the at least one cooling channel14, which has the plurality of channel cross-sections12disposed at intervals in the first direction d1, between the first wall section6and the second wall section8.

In the configuration shown inFIG. 12, the first wall section6, the second wall section8, and the plurality of partition wall sections10constitute a cooling channel structure100F including the at least one cooling channel14. That is, the cooling channel14, through which the cooling medium for cooling the nozzle skirt50flows, is formed in the inner portion of the nozzle skirt50itself (the thick inner portion of the nozzle skirt50), and the nozzle skirt50itself constitutes the cooling channel structure100F.

In the cross-section shown inFIG. 12, since at least the part of each partition wall section10extends along the direction intersecting with the second direction d2, it is possible to suppress the damage to the first wall section6by reducing the constraint force of the thermal deformation received from the partition wall section10by the first wall section6, while maintaining the density of the cooling channel14.

Further, in some embodiments described above, the cases where the tubular members constitute the cooling channel structures100A to100F, respectively, have been exemplified. That is, the cases where the first wall section6and the second wall section8are each formed into the tubular shape have been exemplified. However, in other embodiments, each of the first wall section6and the second wall section8is not limited to have the cylindrical shape but may have, for example, a tubular shape with a polygonal cross-section, and for example, as shown inFIG. 13, each of the first wall section6and the second wall section8may be formed in parallel to a plane S along the plane S. In this case, at least a part of each partition wall section10extends along a direction intersecting with the direction (second direction) orthogonal to the plane S.

In the cross-section shown inFIG. 13, each of the channel cross-sections12has the arrow shape including the substantially triangle, and each of the partition wall sections10includes the first inclined wall portion16linearly extending from the first wall section6along the direction a (third direction) intersecting with the radial direction, and the second inclined wall portion18linearly extending from the second wall section8along the direction b (fourth direction) intersecting with each of the radial direction and the direction a to be connected to the first inclined wall portion16. In the illustrated cross-section, the direction a is a direction toward one side in the direction d1with increasing distance from the first wall section6, and the direction b is a direction toward the above-described one side in the first direction with increasing distance from the second wall section8.

In the configuration shown inFIG. 13, the first wall section6, the second wall section8, and the plurality of partition wall sections10constitute a cooling channel structure100G including the at least one cooling channel14. The cooling channel structure100G shown inFIG. 13is applicable to, for example, a water wall of a boiler furnace or the like. With the configuration shown inFIG. 13, the constraint force of the thermal deformation received from the partition wall section10by the first wall section6is reduced, making it possible to suppress the damage to the first wall section6.

Further, in some embodiments described above, the configuration has been exemplified in which the first wall section6and the second wall section8(and the third wall section20) are arranged in parallel. However, the first wall section6and the second wall section8(and the third wall section20) may not necessarily be arranged in parallel.

The contents described in the above embodiments would be understood as follows, for instance.

(1) A cooling channel structure (100A to100G) according to the present disclosure includes a first wall section (such as the above-described first wall section6of each embodiment) extending along a first direction (such as the axial direction in the burner tube5(5A to5E), the first direction d1in the nozzle skirt50, and the first direction d1in the water wall52described above), a second wall section (such as the above-described second wall section8of each embodiment) disposed at an interval from the first wall section in a second direction (such as the radial direction in the burner tube5(5A to5E), the second direction d2in the nozzle skirt50, and the second direction d2in the water wall52described above) orthogonal to the first direction, at least one cooling channel (such as the above-described at least one cooling channel14of each embodiment) which has a plurality of channel cross-sections (such as the above-described plurality of channel cross-sections12of each embodiment) disposed at intervals in the first direction, the cooling channel being formed between the first wall section and the second wall section, and a plurality of partition wall sections (such as the above-described plurality of partition wall sections10of each embodiment) disposed in the cooling channel, connecting the first wall section and the second wall section, and forming a wall surface of the cooling channel. In a cross-section including the first direction and the second direction, at least a part of each of the partition wall sections extends along a direction (such as the direction a, b, e and the direction along the arc in the embodiment shown inFIG. 10described above) intersecting with the second direction.

With the cooling channel structure according to the above configuration (1), since at least the part of each of the partition wall sections extends along the direction intersecting with the second direction, compared with the configuration where the partition wall section extends in parallel to the second direction (the direction orthogonal to the first direction), it is possible to suppress the damage to the first wall section caused by the thermal stress by reducing the constraint force of the thermal deformation received from the partition wall section by the first wall section, while maintaining the density of the cooling channel.

(2) In some embodiments, in the cooling channel structure according to the above configuration (1), in the cross-section including the first direction and the second direction, each of the partition wall sections is formed along an arc.

With the cooling channel structure according to the above configuration (2), since each of the partition wall sections is formed along the arc, it is possible to implement the cooling channel structure which is particularly favorable in terms of pressure resistance and pressure loss of the cooling channel.

(3) In some embodiments, in the cooling channel structure according to the above configuration (1), in the cross-section including the first direction and the second direction, each of the partition wall sections includes a first inclined wall portion (such as the above-described first inclined wall portion16) extending from the first wall section in a third direction (such as the above-described direction a) intersecting with the second direction, and a second inclined wall portion (such as the above-described second inclined wall portion18) extending from the second wall section in a fourth direction (such as the above-described direction b) intersecting with each of the second direction and the third direction to be connected to the first inclined wall portion.

With the cooling channel structure according to the above configuration (3), since each of the channel cross-sections of the cooling channel has the shape including the substantially triangle, it is possible to implement the cooling channel structure which is favorable in terms of pressure resistance of the cooling channel, in terms of the pressure loss of the cooling channel, and in terms of the thermal stress caused in the first wall section.

(4) In some embodiments, in the cooling channel structure according to the above configuration (3), each of the partition wall sections includes the first inclined wall portion and the second inclined wall portion, and the third direction is a direction toward one side in the first direction with increasing distance from the first wall section, and the fourth direction is a direction toward the above-described one side in the first direction with increasing distance from the second wall section.

With the cooling channel structure according to the above configuration (4), since each of the channel cross-sections of the cooling channel has the shape including the substantially triangle, it is possible to implement the cooling channel structure which is favorable in terms of pressure resistance of the cooling channel, in terms of the pressure loss of the cooling channel, and in terms of the thermal stress caused in the first wall section.

(5) In some embodiments, in the cooling channel structure according to the above configuration (1), in the cross-section including the first direction and the second direction, the partition wall sections extend from the first wall section to the second wall section in a direction (such as the above-described direction e) intersecting with the second direction.

With the cooling channel structure according to the above configuration (5), it is possible to implement the cooling channel structure which is particularly favorable in terms of the thermal stress caused in the first wall section.

(6) In some embodiments, in the cooling channel structure according to any one of the above configurations (1) to (5), each of the first wall section and the second wall section is formed into a tubular shape, and the second wall section is disposed on an inner peripheral side of the first wall section.

With the cooling channel structure according to the above configuration (6), it is possible to suppress damage caused by the thermal stress in the tubular structure.

(7) In some embodiments, in the cooling channel structure according to any one of the above configurations (1) to (5), each of the first wall section and the second wall section is formed along a plane (such as the above-described plane S).

With the cooling channel structure according to the above configuration (7), it is possible to suppress damage caused by the thermal stress in the structure along the plane.

(8) In some embodiments, in the cooling channel structure according to any one of the above configurations (1) to (7), the cooling channel structure further includes a third wall section (such as the above-described third wall section20) disposed opposite to the first wall section across the second wall section, and a plurality of partition wall sections (such as the above-described plurality of partition wall sections22) connecting the second wall section and the third wall section so as to form at least one cooling channel (such as the above-described at least one cooling channel34) between the second wall section and the third wall section, the cooling channel having a plurality of channel cross-sections (such as the above-described plurality of channel cross-sections32) disposed at intervals in the first direction. In the cross-section including the first direction and the second direction, at least a part of each of the partition wall sections connecting the second wall section and the third wall section extends along the direction (such as the direction c, d, f and the direction along the arc in the embodiment shown inFIG. 10described above) intersecting with the second direction.

With the cooling channel structure according to the above configuration (8), since at least the part of each of the partition wall sections connecting the second wall section and the third wall section extends along the direction intersecting with the second direction, compared with the configuration where the partition wall section extends in parallel to the second direction (the direction orthogonal to the first direction), it is possible to suppress the damage to the third wall section caused by the thermal stress by reducing the constraint force of the thermal deformation received from the partition wall section by the third wall section, while maintaining the density of the cooling channel.

(9) In some embodiments, in the cooling channel structure according to the above configuration (8), in the cross-section including the first direction and the second direction, at least a part of the second wall section extends along a direction (such as the extension direction of the fifth inclined wall portion42, the extension direction of the sixth inclined wall portion44, and the extension direction of the seventh inclined wall portion46shown inFIG. 9) intersecting with the first direction.

With the cooling channel structure according to the above configuration (9), since at least the part of the second wall section extends along the direction intersecting with the first direction, it is possible to suppress the damage to the first wall section and the third wall section caused by the thermal stress by reducing the constraint force of the thermal deformation in the first direction received from the second wall section by the first wall section and the third wall section.

(10) In some embodiments, in the cooling channel structure according to the above configuration (8) or (9), in the cross-section including the first direction and the second direction, the partition wall sections connecting the first wall section and the second wall section extend from the first wall section to the second wall section in the direction intersecting with the second direction, and the partition wall sections connecting the second wall section and the third wall section extend from the third wall section to the second wall section in the direction intersecting with the second direction.

With the cooling channel structure according to the above configuration (10), it is possible to effectively suppress the damage to the first wall section by effectively reducing the constraint force of the thermal deformation received from the partition wall section by the first wall section.

(11) A burner according to the present disclosure includes the cooling channel structure according to any one of the above configurations (1) to (10).

Since the burner according to the above configuration (11) includes the cooling channel structure according to any one of the above configurations (1) to (10), compared with the configuration where the partition wall sections extend in parallel to the second direction (the direction orthogonal to the first direction), it is possible to suppress the damage to the first wall section caused by the thermal stress by reducing the constraint force of the thermal deformation received from the partition wall sections by the first wall section, while maintaining the density of the cooling channel. Thus, it is possible to suppress damage to the burner.

(12) A heat exchanger according to the present disclosure includes the cooling channel structure according to any one of the above configurations (1) to (10).

Since the heat exchanger according to the above configuration (12) includes the cooling channel structure according to any one of the above configurations (1) to (10), compared with the configuration where the partition wall sections extend in parallel to the second direction (the direction orthogonal to the first direction), it is possible to suppress the damage to the first wall section caused by the thermal stress by reducing the constraint force of the thermal deformation received from the partition wall sections by the first wall section, while maintaining the density of the cooling channel. Thus, it is possible to suppress damage to the heat exchanger.

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