JP2021188843A - Gas combustion apparatus - Google Patents

Abstract

To provide a gas combustion apparatus capable of suppressing increase in the size.SOLUTION: A gas combustion apparatus includes a burner 2 and a furnace body 3. The furnace body 3 includes a body part 10. The body part 10 includes an upstream wall 15, a downstream wall 17 and a peripheral wall 16 connecting the upstream wall 15 with the downstream wall 17. The upstream wall 15 includes a burning port 20 and a plurality of first air supply ports 21 disposed around the burning port 20 and supplying dilution air AD to a combustion chamber 4. The downstream wall 17 includes at least one discharge port 33 for discharging mixed gas GM.SELECTED DRAWING: Figure 13

Description

The present invention relates to a gas combustion device.

Patent Document 1 discloses a gas combustion device. The gas combustion device includes an inner cylinder having a combustion chamber and an discharge port provided on the side surface of the inner cylinder. The incinerator exhaust gas is discharged from the discharge port.

Japanese Unexamined Patent Publication No. 2017-150699

By the way, in order to burn a large amount of gas, it is necessary to increase the size of the gas combustion device. However, if the gas combustion device is made large, the weight increases and there is a problem in terms of installation space. Therefore, we provide a gas combustion device that can suppress the increase in size.

(1) A gas combustion device that solves the above problems includes a burner and a furnace body that burns fuel gas supplied from the burner and combustion air to generate combustion gas, and the furnace body burns. It has a main body portion constituting the chamber, and the main body portion covers the upstream wall provided on the upstream side of the combustion chamber, the downstream wall provided on the downstream side of the combustion chamber, and the periphery of the combustion chamber. The upstream wall includes a peripheral wall connecting the upstream wall and the downstream wall, and the upstream wall has a fire port and a plurality of air supply ports arranged around the fire port to supply diluted air to the combustion chamber. The downstream wall has at least one outlet for discharging a mixed gas in which the diluted air and the combustion gas are mixed.

According to this configuration, an air layer can be formed around the combustion gas by supplying diluted air to the combustion chamber from the air supply port. The air layer can suppress the temperature rise of the peripheral wall of the main body by preventing the convection heat transfer to the peripheral wall by the high-temperature combustion gas. Therefore, the peripheral wall of the main body can be formed by the member having low heat resistance, and the weight increase of the main body can be suppressed.

(2) In the gas combustion device, the main body portion includes a first air supply port as the air supply port and a second air supply port provided on the peripheral wall to supply diluted air to the combustion chamber. .. According to this configuration, the combustion gas is further diluted with the diluted air, so that the temperature rise of the combustion gas can be suppressed. As a result, the main body can be configured by a member having low heat resistance, and an increase in weight can be suppressed. Further, since the diluted air supplied from the second air supply port causes convection mixing with the combustion gas, the height at which the high temperature region of the combustion gas is generated can be suppressed, so that the combustion chamber can be made smaller. In this way, it is possible to suppress the increase in size of the gas combustion device.

(3) In the gas combustion device, the furnace body further has a passage portion provided so as to surround at least a part of the peripheral wall and the upstream wall of the main body portion and configured to allow the diluted air to pass therethrough. The passage portion is connected to the first air supply port. According to this configuration, the main body can be cooled by the diluted air. As a result, the main body can be configured by a member having low heat resistance, and the weight increase of the main body can be suppressed.

(4) In the gas combustion device, the furnace body further includes a mixing unit for mixing the mixed gas discharged from the discharge port and the diluted air. According to this configuration, the mixed gas discharged from the discharge port can be cooled by the diluted air. As a result, the downstream portion of the furnace body can be formed by the member having low heat resistance, and the weight increase of the furnace body can be suppressed.

(5) In the gas combustion device, the downstream wall is configured such that the central portion intersecting the central axis of the burner projects to the downstream side, and the downstream wall is provided with a plurality of the discharge ports. The plurality of outlets are arranged in the circumferential direction of the virtual circle about the central axis, and each of the plurality of outlets opens in the radial direction. According to this configuration, the mixed gas discharged from the discharge port and the diluted air can be efficiently mixed by convection mixing, so that the mixed gas discharged from the discharge port can be cooled quickly. As a result, it is possible to suppress the increase in size of the furnace body.

According to the gas combustion device, it is possible to suppress the increase in size of the furnace body.

Perspective view of the gas combustion device. Perspective view of the furnace body. Perspective view of the main body. Front view of the main body. Top view of the upstream wall seen from above. FIG. 6 is a cross-sectional view of a main body along the VI-VI line of FIG. Top view of the downstream wall seen from above. FIG. 2 is a cross-sectional perspective view of the furnace body along the line VIII-VIII of FIG. FIG. 8 is a cross-sectional view of the furnace body along the IX-IX line of FIG. Partial plan view of the first straightening vane. FIG. 8 is a cross-sectional perspective view of the furnace body along the XI-XI line of FIG. FIG. 11 is a cross-sectional perspective view of the furnace body along the XII-XII line of FIG. FIG. 2 is a cross-sectional view of the furnace body along the line VIII-VIII of FIG. Sectional drawing of the downstream wall which has a modification of a discharge guide. Cross-sectional view of a modified example of the main body. Cross-sectional perspective view of a modified example of the main body. A perspective view of a modified example of the downstream wall. Cross-sectional view of a modified example of the downstream wall.

The gas combustion apparatus will be described with reference to FIGS. 1 to 13.
The gas combustion device 1 burns the fuel gas GF. Specifically, the gas combustion device 1 burns unnecessary fuel gas GF. Examples of the fuel gas GF include liquefied natural gas (hereinafter referred to as LNG). In LNG carriers and LNG fueled ships, LNG in the fuel tank volatilizes during operation and Boil Off Gas (hereinafter referred to as BOG) is generated. The release of BOG into the atmosphere is regulated in order to prevent global warming and reduce the environmental burden. Therefore, in the LNG carrier and the LNG fuel ship, the BOG is burned by the gas combustion device 1. As another example, when supplying LNG to the fuel tank or emptying the fuel tank, the fuel gas GF discharged as BOG containing nitrogen and other inert gas existing in the fuel tank is used as a gas combustion device. Burn by 1. Hereinafter, an example of the gas combustion device 1 will be described.

As shown in FIG. 1, the gas combustion device 1 includes a burner 2 and a furnace body 3. In the present embodiment, the gas combustion device 1 further includes a gantry 5. The furnace body 3 is attached to the gantry 5. The burner 2 is mounted under the furnace body 3 and is arranged in the gantry 5.

The burner 2 supplies the fuel gas GF and the combustion air AB to the furnace body 3. In one example, the burner 2 includes a throat 2a, a fuel supply pipe (not shown) for supplying fuel gas GF, and a pilot burner (not shown) (see FIG. 13). The pilot burner operates as an ignition source or an auxiliary combustion source when burning the fuel gas GF.

The furnace body 3 burns the fuel gas GF supplied from the burner 2 and the combustion air AB to generate the combustion gas GB.
The furnace body 3 has a main body portion 10 constituting the combustion chamber 4. Further, the furnace body 3 preferably has a passage portion 11 through which the diluted air AD passes. Further, the furnace body 3 preferably has a mixing unit 12. Further, the furnace body 3 preferably has a guide unit 13 that sends the diluted air AD to the mixing unit 12. Further, it is preferable that the furnace body 3 has a passage portion 11 and a connecting portion 14 for connecting the guide portion 13 and the duct 6.

As shown in FIG. 2, in the present embodiment, the furnace body 3 includes a main body portion 10 and an accommodating portion 40 for accommodating the main body portion 10. The passage portion 11, the mixing portion 12, and the guide portion 13 are provided between the accommodating portion 40 and the main body portion 10 (see FIG. 8).

The main body 10 will be described with reference to FIGS. 3 to 8.
As shown in FIGS. 4 and 8, the main body 10 has an upstream wall 15 provided on the upstream side of the combustion chamber 4, a downstream wall 17 provided on the downstream side of the combustion chamber 4, and a periphery of the combustion chamber 4. A peripheral wall 16 connecting the upstream wall 15 and the downstream wall 17 is provided so as to cover the upstream wall 15.

In the present embodiment, the fuel gas GF and the combustion air AB are supplied to the burner 2 in the main body 10, and the fuel gas GF and the combustion air AB are mixed at the firing port 20 described later, and the flame is formed by the pilot burner. It is ignited and fueled by the gas flame to be formed, and combustion gas GB is generated. In the present embodiment, the central axis of the burner 2 is referred to as "axis LG" (see FIG. 13). The direction of the axis LG coincides with the vertical DA.

The main body 10 is configured to surround the combustion gas GB generated along the axis LG. The downstream wall 17 is arranged at a position above the upstream wall 15. The downstream wall 17 when the upstream wall 15 is used as a reference plane is arranged at a position sufficiently higher than the height of the flame formed by mixing and burning the fuel gas GF and the combustion air AB.

The upstream wall 15 is made of a refractory material or a heat insulating material. Examples of the refractory material include refractory concrete called castable. Castables are formed by mixing an aggregate with excellent fire resistance and alumina cement. Wetfurt may be used as the heat insulating material. Wet felt is a wet sheet-like product in which an inorganic binder is impregnated in a blanket. It is molded into a predetermined shape in advance, dried to cure, and molded to complete the production. The downstream wall 17 and the peripheral wall 16 are formed of metal. The downstream wall 17 and the peripheral wall 16 are formed of, for example, iron or an iron alloy.

As shown in FIG. 5, the upstream wall 15 has a firing port 20 and a plurality of first air supply ports 21. At the firing port 20, the fuel gas GF supplied by the burner 2 and the combustion air AB are mixed as described above to form a flame, and the combustion gas GB is generated. The firing port 20 is provided in the central portion of the upstream wall 15. The firing port 20 is provided with a tubular member 22 that surrounds the firing port 20, and a burner 2 is arranged inside the tubular member 44 (see below) that communicates with the tubular member 22 (see FIG. 13). The tubular member 22 is provided on the lower surface of the upstream wall 15 so as to project downward.

The first air supply port 21 is an opening for supplying the diluted air AD to the combustion chamber 4. The plurality of first air supply ports 21 are arranged around the firing port 20 on the upstream wall 15. The plurality of first air supply ports 21 are arranged at equal intervals in a virtual circle centered on the axis LG.

The diluted air AD supplied from the first air supply port 21 rises along the peripheral wall 16 (see FIG. 8). The diluted air AD supplied from the plurality of first air supply ports 21 forms an air layer AL surrounding the flame that generates the combustion gas GB. Such an air layer AL suppresses heat transfer from the flame to the peripheral wall 16.

The peripheral wall 16 is configured to surround the flame and the combustion gas GB. In the present embodiment, the peripheral wall 16 is formed in a cylindrical shape centered on the axis LG. The peripheral wall 16 is provided with a plurality of second air supply ports 25. The second air supply port 25 is an opening for supplying the diluted air AD to the combustion chamber 4.

As shown in FIGS. 3 and 4, the plurality of second air supply ports 25 are provided so that all the second air supply ports 25 are arranged at the same height in the vertical DA. In the present embodiment, the heights of the plurality of second air supply ports 25 are set so that the end height of the flame length that generates the combustion gas GB is set as the target height, for example, the plurality of second air supply ports. Reference numeral 25 is arranged at a position substantially half the height of the main body portion 10. Further, the plurality of second air supply ports 25 are arranged at positions above the partition plate 50. The plurality of second air supply ports 25 are arranged so as to penetrate the peripheral wall portion along the guide portion 13 (see FIG. 8) which is a passage of the diluted air AD.

As shown in FIG. 6, the plurality of second air supply ports 25 are provided at equal intervals in a virtual circle centered on the axis LG. The second air supply port 25 is provided with an air supply guide 26 for guiding the diluted air AD. The air supply guide 26 is formed in a cylindrical shape. In FIG. 6, the partition plate 50 is omitted.

In one example, the central axis of the air supply guide 26 extends in the radial direction DR (hereinafter, simply referred to as “diameteral DR”) of the virtual circle centered on the axis line LG. The air supply guide 26 includes an inner portion 27 arranged inside the peripheral wall 16 and an outer portion 28 arranged outside the peripheral wall 16. The surface PA along the opening end 28a of the outer portion 28 is inclined with respect to the radial line LR extending in the radial direction DR when viewed from the direction along the axis line LG. Specifically, the surface PA along the opening end 28a of the outer portion 28 is inclined toward the outer EX of the radial DR toward the swirling direction DS (see FIG. 9) of the diluted air AD. With such a configuration, the diluted air AD is promoted to flow into the main body 10 (see FIG. 9).

The downstream wall 17 is arranged in the main body 10 so as to face the upstream wall 15. The downstream wall 17 is configured such that the central portion 31 intersecting the axis LG projects to the downstream side. In the present embodiment, the downstream wall 17 includes a central portion 31 and an inclined portion 32 provided so as to surround the central portion 31. The central portion 31 may be a flat surface or a curved surface. The inclined portion 32 is inclined so as to approach the axis LG from the outer periphery of the downstream wall 17 toward the downstream side of the injection direction DJ of the combustion gas GB.

In the portion between the downstream wall 17 and the second air supply port 25 in the vertical direction DA, a mixed gas GM of the diluted air AD and the combustion gas GB is generated. Specifically, the combustion gas GB generated in the furnace body 3 and the diluted air AD supplied from the second air supply port 25 are mixed to generate a mixed gas GM. Further, when the combustion gas GB hits the central portion 31 of the downstream wall 17, it spreads along the inclined portion 32 around the central portion 31, and the diluted air AD supplied from the first air supply port 21 of the upstream wall 15 is generated. By hitting the downstream wall 17, the combustion gas GB and the diluted air AD are mixed to generate a mixed gas GM. By mixing the combustion gas GB and the diluted air AD, the temperature of the mixed gas GM becomes lower than the temperature of the combustion gas GB.

The downstream wall 17 has at least one outlet 33. Preferably, the downstream wall 17 is provided with a plurality of outlets 33. The discharge port 33 discharges the mixed gas GM. The discharge port 33 is provided on the inclined portion 32 of the downstream wall 17. The plurality of discharge ports 33 are arranged in the circumferential direction of the virtual circle centered on the axis LG.

As shown in FIGS. 4 and 7, the plurality of discharge ports 33 are divided into two stages in the vertical direction DA. In the present embodiment, of the two stages, the stage arranged below is referred to as a lower stage, and the stage arranged above the lower stage is referred to as an upper stage.

As shown in FIG. 7, the lower discharge ports 33 are arranged at equal intervals along a virtual circle centered on the axis LG. The upper discharge ports 33 are arranged at equal intervals along a virtual circle centered on the axis LG. The upper discharge port 33 is arranged so that the center of the discharge port 33 is located between the two lines connecting the centers of the two lower discharge ports 33 adjacent to each other and the axis LG.

Each of the plurality of discharge ports 33 opens toward the radial DR when viewed from the direction along the axis LG. Specifically, the discharge port 33 is provided with a discharge guide 34 that guides the mixed gas GM. The discharge guide 34 is formed in a cylindrical shape. In one example, the central axis of the discharge guide 34 extends in the radial DR (see FIG. 13). As shown in FIG. 14, the discharge guide 34 may be attached to the inclined portion 32 so that the central axis CG of the discharge guide 34 is slanted with respect to the line along the radial DR.

The discharge guide 34 is provided on the outer surface of the inclined portion 32. The surface PB along the opening end 34a of the discharge guide 34 is located outside the position of the lower end portion 33a of the discharge port 33 in the radial DR (see FIG. 13). With such a configuration, the mixed gas GM generated around the downstream wall 17 enters the discharge port 33 and then is guided in the radial DR and flows out. The discharge guide 34 also has an effect as an eaves for rain entering from the outside.

The outline of the passage portion 11, the mixing portion 12, and the guide portion 13 will be described with reference to FIG.
The passage portion 11 is configured to allow the diluted air AD supplied to the main body portion 10 to pass through. The passage portion 11 is provided so as to surround at least a part of the peripheral wall 16 and the upstream wall 15 of the main body portion 10. The diluted air AD flowing through the passage portion 11 cools the upstream wall 15 and the peripheral wall 16 of the main body portion 10. As a result, overheating of the main body 10 is suppressed. The passage portion 11 is connected to the first air supply port 21.

The mixing unit 12 is a portion that mixes the mixed gas GM discharged from the discharge port 33 and the diluted air AD. The mixing portion 12 is located near the outlet of the discharge port 33 of the main body portion 10. By mixing the mixed gas GM and the diluted air AD in the mixing unit 12, the temperature of the mixed gas GM is further lowered.

The guide unit 13 is a passage for sending the diluted air AD to the mixing unit 12. The guide portion 13 is provided so as to surround at least a part of the peripheral wall 16 of the main body portion 10. The diluted air AD flowing through the guide portion 13 cools the peripheral wall 16. As a result, overheating of the peripheral wall 16 is suppressed. In the present embodiment, the guide unit 13 sends the diluted air AD to the mixing unit 12, and also sends the diluted air AD to the second air supply port 25.

The passage portion 11, the mixing portion 12, the guide portion 13, and the connection portion 14 will be described with reference to FIGS. 8 to 13. In the present embodiment, as described above, the passage portion 11, the mixing portion 12, and the guide portion 13 are provided between the accommodating portion 40 and the main body portion 10. The connecting portion 14 is provided in the accommodating portion 40.

The diluted air AD is the air supplied to the combustion chamber 4 for diluting the combustion gas GB. The outside air around the gas combustion device 1 is used as the diluted air AD. For example, the outside air taken in by a device having a blower fan (not shown) is sent to the passage portion 11 and the guide portion 13 via the duct 6 as diluted air AD. The passage portion 11, the guide portion 13, and the duct 6 are connected via the connecting portion 14.

As shown in FIG. 8, the accommodating portion 40 is configured to cover at least a part of the main body portion 10. The accommodating portion 40 includes an outer peripheral wall 41 and a bottom wall 42. The outer peripheral wall 41 can be divided into three in the vertical direction DA. In the present embodiment, the decorative panel 45 is attached to the outside of the outer peripheral wall 41. The bottom wall 42 is attached to the bottom of the outer peripheral wall 41.

The outer peripheral wall 41 is configured to surround the peripheral wall 16 of the main body 10. In the present embodiment, the outer peripheral wall 41 is formed in a cylindrical shape centered on the axis LG. The outer peripheral wall 41 has a central axis (axis center along the axis LG) common to the peripheral wall 16 of the main body 10. In the radial DR, an annular first space SA is formed between the outer peripheral wall 41 and the peripheral wall 16 of the main body 10. Further, in the radial DR, an annular second space SB is formed between the outer peripheral wall 41 and the downstream wall 17 of the main body 10. The above-mentioned mixing unit 12 includes a second space SB.

In the outer peripheral wall 41, the end portion on the opposite side to the bottom wall 42 is opened. The opening end 41a of the outer peripheral wall 41 is arranged above the upstream wall 15. The open end 41a of the outer peripheral wall 41 is connected to the exhaust pipe. The exhaust pipe guides the mixed gas GM to the outside.

The bottom wall 42 is arranged below the upstream wall 15 of the main body 10. An annular third space SC is provided between the bottom wall 42 and the upstream wall 15. An opening 43 through which the fuel gas GF and the combustion air AB pass is provided in the central portion of the bottom wall 42. The opening 43 is arranged below the firing port 20 of the main body 10. The opening 43 and the firing port 20 are connected by a tubular member 22. Further, a flange 44a is provided below the opening 43 via the tubular member 44. The flange 2b of the throat 2a of the burner 2 is coupled to the flange 44a (see FIG. 13). The bottom wall 42 supports the main body 10 via a plurality of support members 47.

The support member 47 is provided on the bottom wall 42. The support member 47 has a first support portion 48 that supports the upstream wall 15 of the main body portion 10, and a second support portion 49 that supports the peripheral wall 16 of the main body portion 10. The first support portion 48 extends along the radial DR. The plurality of first support portions 48 are arranged at equal intervals in the circumferential direction. The first support portion 48 is arranged so as to separate each of the plurality of first air supply ports 21 by the first support portion 48. The second support portion 49 is provided at the outer end portion of the radial DR in the first support portion 48. The second support portion 49 extends upward from the outer end portion. The second support portion 49 is arranged between the peripheral wall 16 of the main body portion 10 and the outer peripheral wall 41.

The space between the accommodating portion 40 and the main body portion 10 is partitioned by the partition plate 50. The partition plate 50 is provided in the first space SA between the outer peripheral wall 41 of the accommodating portion 40 and the peripheral wall 16 of the main body portion 10. The partition plate 50 is arranged below the second air supply port 25 in the vertical DA.

In the space between the accommodating portion 40 and the main body portion 10, the space below the partition plate 50 constitutes the passage portion 11. The passage portion 11 is connected to the first air supply port 21 of the main body portion 10. In the space between the accommodating portion 40 and the main body portion 10, the space above the partition plate 50 constitutes the guide portion 13. The guide portion 13 is connected to the second air supply port 25 of the main body portion 10 and is connected to the mixing portion 12.

An opening 46 is provided in a portion of the outer peripheral wall 41 where the partition plate 50 is provided. In the outer peripheral wall 41, the opening 46 is provided so as to extend over the partition plate 50. The opening 46 is divided into a first opening 46a connected to the passage portion 11 by a partition plate 50 and a second opening 46b connected to the guide portion 13. A connection portion 14 is attached to the opening portion 46.

The connection portion 14 separates the diluted air AD. The connection portion 14 includes a first connection passage portion 36 connected to the passage portion 11 and a second connection passage portion 37 connected to the guide portion 13. The diluted air AD separated by the connecting portion 14 is sent to the guide portion 13 and the passage portion 11, respectively.

As shown in FIG. 9, the connecting portion 14 is attached to the outer peripheral wall 41 so that the extension direction of the connecting portion 14 is parallel to the tangent line LA in contact with the peripheral wall 16 of the main body portion 10 when viewed from the direction along the axis LG. It is attached. Specifically, the center line LC of the connecting portion 14 is arranged between the tangent LA that is in contact with the peripheral wall 16 of the main body 10 and the line LB that is parallel to the tangent LA and intersects the axis LG. The connecting portion 14 is attached to the accommodating portion 40. By such attachment, the diluted air AD supplied to the guide portion 13 and the passage portion 11 via the connection portion 14 swirls.

The first connection passage portion 36 of the connection portion 14 is connected to the passage portion 11 via the first opening 46a. The second connection passage portion 37 of the connection portion 14 is connected to the guide portion 13 via the second opening portion 46b.

The passage portion 11 is configured to guide the diluted air AD to the first air supply port 21. The passage portion 11 has an annular passage 51 between the peripheral wall 16 of the main body portion 10 and the outer peripheral wall 41, and a bottom passage 55 between the upstream wall 15 and the bottom wall 42 of the main body portion 10. The annular passage 51 is divided into a first annular passage 53 and a second annular passage 54 by a first baffle plate 52. The first annular passage 53 has a first opening 46a to which the first connection passage portion 36 of the connection portion 14 is connected. The second annular passage 54 is provided between the first annular passage 53 and the bottom passage 55.

As shown in FIG. 10, the first straightening vane 52 is provided with a plurality of through holes 52a. The first straightening vane 52 guides the diluted air AD to flow in the circumferential direction so that the diluted air AD is evenly distributed in the circumferential direction, and the diluted air AD is rectified and guided downward. Specifically, the diluted air AD supplied from the outside swirls in the first annular passage 53. As a result, the diluted air AD can be evenly distributed in the circumferential direction, and the flow rate distribution of the diluted air AD flowing from the first annular passage 53 to the second annular passage 54 in the circumferential direction can be rectified and made uniform.

The second annular passage 54 is connected to the outer peripheral portion of the bottom passage 55. The second annular passage 54 is connected to the bottom passage 55 so as to intersect the bottom passage 55. The second annular passage 54 constitutes a bent passage integrated with the bottom passage 55. The second annular passage 54 is connected to the first air supply port 21 via the bottom passage 55.

As shown in FIGS. 11 and 12, the region of the second annular passage 54 on the side of the first air supply port 21 is partitioned by the support member 47. Each of the small passages 57 partitioned by the support member 47 is connected to the first air supply port 21. The diluted air AD that has entered the second annular passage 54 flows into the first air supply port 21 through the small passage 57 partitioned by the second support portion 49.

The guide unit 13 guides the diluted air AD so that the diluted air AD flows toward the mixing unit 12. The guide portion 13 is configured as a passage between the peripheral wall 16 of the main body portion 10 and the outer peripheral wall 41. The guide portion 13 is partitioned by a second straightening vane 61 into a third annular passage 62 and a fourth annular passage 63 above the third annular passage 62. The second straightening vane 61 is arranged between the second air supply port 25 and the mixing unit 12 in the vertical DA. The third annular passage 62 has a second opening 46b to which the second connecting passage portion 37 of the connecting portion 14 is connected. The third annular passage 62 is provided in a portion of the peripheral wall 16 having the second air supply port 25. The fourth annular passage 63 is provided between the third annular passage 62 and the mixing portion 12.

The third annular passage 62 is surrounded by a partition plate 50, a second straightening vane 61, an outer peripheral wall 41, and a peripheral wall 16 having a second air supply port 25. The diluted air AD supplied to the third annular passage 62 is supplied to the main body 10 through the second air supply port 25 while swirling.

Like the first rectifying plate 52, the second rectifying plate 61 is provided with a plurality of through holes. The second straightening vane 61 guides the diluted air AD so that the diluted air AD flows in the circumferential direction so that the diluted air AD is evenly distributed in the circumferential direction, and the diluted air AD is rectified and guided upward. Specifically, the diluted air AD supplied from the outside swirls in the third annular passage 62. As a result, the diluted air AD can be evenly distributed in the circumferential direction, and the flow rate distribution of the diluted air AD flowing from the third annular passage 62 to the fourth annular passage 63 in the circumferential direction can be rectified and made uniform.

The fourth annular passage 63 is connected to the mixing portion 12. The mixing portion 12 includes an annular second space SB between the inclined portion 32 of the main body portion 10 and the outer peripheral wall 41. The mixed gas GM flows into the mixing portion 12 from the downstream wall 17, and the diluted air AD flows into the mixing portion 12 through the fourth annular passage 63. In the mixing unit 12, the flow of the mixed gas GM and the flow of the diluted air AD intersect, and the mixed gas GM and the diluted air AD are mixed.

The operation of this embodiment will be described with reference to FIG.
The diluted air AD supplied to the furnace body 3 is divided into the passage portion 11 and the guide portion 13. The diluted air AD passing through the passage portion 11 flows to the lower part of the main body portion 10 while swirling along the peripheral wall 16 of the main body portion 10, and flows into the combustion chamber 4 from the first air supply port 21 of the upstream wall 15. The diluted air AD passing through the guide portion 13 flows upward while swirling along the peripheral wall 16 of the main body portion 10, and flows into the mixing portion 12. In this way, the diluted air AD flows along the peripheral wall 16 of the main body 10 before being supplied to the combustion chamber 4. As a result, the main body 10 is cooled.

The diluted air AD is supplied to the first air supply port 21 of the main body 10. The first air supply port 21 is arranged around the firing port 20. Therefore, an air layer AL is formed around the combustion gas GB. Since the air layer AL is a layer having a flow in the direction along the axis LG of the diluted air AD, it is difficult to mix with the combustion gas GB, so that the temperature of the air layer AL is unlikely to rise. In this way, the air layer AL protects the peripheral wall 16 of the main body 10 from the combustion gas GB.

Further, the diluted air AD is supplied to the combustion chamber 4 so as to intersect the combustion gas GB via the second air supply port 25. That is, the diluted air AD is supplied so as to collide with the combustion gas GB as a plurality of air jets from the periphery of the combustion gas GB when viewed from the direction along the axis LG. As a result, the temperature of the combustion gas GB can be sharply lowered.

The combustion gas GB spreads along the entire downstream wall 17, and is diluted with the combustion gas GB by the diluted air AD supplied from the first air supply port 21 and the second air supply port 25 hitting the downstream wall 17. It mixes with air AD to generate a mixed gas GM. The mixed gas GM flows out from the downstream wall 17 and flows into the mixing unit 12. The mixed gas GM is mixed with the diluted air AD supplied from below the mixing unit 12 in the mixing unit 12 and flows upward. In this way, the temperature of the combustion gas GB can be further lowered by mixing with the diluted air AD.

The following effects can be obtained by the above actions.
Before being supplied to the combustion chamber 4, the diluted air AD is flowed along the main body 10 to cool the main body 10. The fire resistance of the peripheral wall 16 of the main body 10 can be lowered, and the weight increase of the main body 10 can be suppressed.

Since the inside of the peripheral wall 16 of the main body 10 is protected by the air layer AL formed by the diluted air AD, the fire resistance of the peripheral wall 16 of the main body 10 can be lowered, and the peripheral wall 16 of the main body 10 can be lowered. Weight increase can be suppressed.

The combustion gas GB collides with the combustion gas GB and is mixed by the flow of jet-shaped diluted air AD supplied from the plurality of second air supply ports 25. As a result, it is possible to prevent the high temperature portion of the combustion gas GB from increasing in the vertical direction DA. As a result, it is possible to suppress the increase in size of the main body 10. Further, the combustion gas GB can be rapidly cooled by radially dispersing the combustion gas GB by the downstream wall 17 of the main body 10 and mixing it with the diluted air AD. As a result, it is possible to suppress an increase in the size of the accommodating portion 40.

The effect of this embodiment will be described.
(1) In the gas combustion device 1, the main body 10 of the furnace body 3 includes an upstream wall 15, a peripheral wall 16, and a downstream wall 17. The upstream wall 15 has a heating port 20 and a plurality of first air supply ports 21 arranged around the heating port 20 to supply the diluted air AD to the combustion chamber 4. The downstream wall 17 has at least one discharge port 33 for discharging the mixed gas GM in which the diluted air AD and the combustion gas GB are mixed.

According to this configuration, the air layer AL can be formed around the combustion gas GB by supplying the diluted air AD into the combustion chamber 4 from the first air supply port 21. The air layer AL can suppress the temperature rise of the peripheral wall 16 of the main body 10 by preventing the convection heat transfer to the peripheral wall 16 by the high temperature combustion gas. Therefore, the peripheral wall 16 of the main body portion 10 can be formed by a member having low heat resistance, and the weight increase of the main body portion 10 can be suppressed.

(2) The main body 10 further includes a second air supply port 25 for supplying the diluted air AD to the combustion chamber 4. The second air supply port 25 is provided on the peripheral wall 16. According to this configuration, since the combustion gas GB is further diluted by the diluted air AD, the temperature rise of the combustion gas GB can be suppressed. As a result, the main body portion 10 can be configured by a member having low heat resistance, and an increase in weight can be suppressed. Further, since the diluted air AD supplied from the second air supply port 25 causes convection mixing with the combustion gas GB, the height at which the high temperature region of the combustion gas GB is generated can be suppressed, so that the combustion chamber 4 can be made smaller. In this way, it is possible to suppress the increase in size of the gas combustion device 1.

(3) The furnace body 3 further includes a passage portion 11. The passage portion 11 is provided so as to surround at least a part of the peripheral wall 16 and the upstream wall 15, and is configured to allow the diluted air AD to pass through. The passage portion 11 is connected to the first air supply port 21. According to this configuration, the main body 10 can be cooled by the diluted air AD. As a result, the main body portion 10 can be configured by a member having low heat resistance, and the weight increase of the main body portion 10 can be suppressed.

(4) The furnace body 3 further includes a mixing unit 12. The mixing unit 12 is configured to mix the mixed gas GM discharged from the discharge port 33 and the diluted air AD. According to this configuration, the mixed gas GM discharged from the discharge port 33 by the diluted air AD can be cooled. As a result, the downstream portion of the furnace body 3 (in this embodiment, the mixing portion 12) can be formed by the member having low heat resistance, and the weight increase of the furnace body 3 can be suppressed.

(5) The downstream wall 17 is configured such that the central portion 31 projects to the downstream side. The plurality of discharge ports 33 provided on the downstream wall 17 are arranged in the circumferential direction of the virtual circle centered on the axis LG. Each of the plurality of discharge ports 33 opens toward the radial DR. According to this configuration, the mixed gas GM discharged from the discharge port 33 and the diluted air AD can be efficiently mixed by convection mixing, so that the mixed gas GM discharged from the discharge port 33 can be quickly cooled. As a result, it is possible to suppress the increase in size of the furnace body 3.

<Other embodiments>
The embodiment is not limited to the example of the above configuration. The above embodiment can be modified as follows. In the following modification, the configuration that is substantially unchanged from the configuration of the above embodiment will be described with the same reference numerals as the configuration of the above embodiment.

-In the present embodiment, the outer peripheral wall 41 of the accommodating portion 40 can be divided into three, but the number of divisions is not limited to this. The outer peripheral wall 41 of the accommodating portion 40 may be disassembled into two or may be configured to be disassembled into four or more. Further, the outer peripheral wall 41 of the accommodating portion 40 may be configured as an integral cylinder that is not divided.

-In the present embodiment, the first air supply port 21 may be configured as an annular through hole surrounding the firing port 20. In this case, the upstream wall 15 of the main body 10 is divided into a first component inside the annular through hole and a second component outside the annular through hole. The first component and the second component are supported independently. The first component may be connected to the second component by a connecting member.

-In the present embodiment, the second air supply port 25 may be configured as an annular slit centered on the axis LG. In this case, the main body portion 10 is divided into an upper portion and a lower portion with the annular slit as a boundary. The upper and lower parts are supported independently. The upper part may be connected to the lower part by a connecting member.

In the present embodiment, in order to send the diluted air AD to the passage portion 11 and the mixing portion 12, one opening 46 is provided in the outer peripheral wall 41, but a plurality of openings 46 are provided in the outer peripheral wall 41. It may be provided.

For example, as shown in FIG. 15, two openings 46 may be provided in the outer peripheral wall 41. The two openings 46 are arranged symmetrically with respect to the axis LG. Each of the two openings 46 is provided with a connecting portion 14 having the above-mentioned structure. The two connecting portions 14 are configured to be point-symmetrical with respect to the axis LG.

In one example, one of the two connecting portions 14 is preliminarily provided. Specifically, a blower is connected to both of the two connecting portions 14 via the duct 6. Normally, one blower is operated. If the blower in use fails, the other blower will be operated. A failed blower can be repaired while the other blower is in operation. In this way, the gas combustion device 1 can be used even if one of the feeders fails. The two blowers may be operated at the same time. For example, when correcting the bias of the flow of diluted air AD in the circumferential direction, or when a large amount of diluted air AD is required, two blowers are operated at the same time. In another example, a blower is connected to one of the two connecting portions 14 via a duct 6, and the other connecting portion 14 is closed with a lid. If the blower fails, a new blower is added and connected to the spare connection 14. In this way, even if one blower fails, the gas combustion device 1 can be continued to be used by additionally installing the blower.

As shown in FIG. 16, in order to protect the outer peripheral wall 41, a protective plate 71 may be provided so as to surround the main body 10. In one example, the protective plate 71 is made of a metal plate. The protective plate 71 may be attached so as to be in close contact with the inner surface of the outer peripheral wall 41. The protective plate 71 may be provided so as to be separated from the outer peripheral wall 41 as follows.

In the present embodiment, the protective plate 71 is provided so as to surround the downstream wall 17 when viewed from the vertical DA. The protective plate 71 is preferably arranged so as to face the open end 34a of the discharge guide 34. As a result, it is possible to prevent the mixed gas GM discharged from the discharge guide 34 from directly hitting the outer peripheral wall 41.

In the present embodiment, the protective plate 71 is arranged between the outer peripheral wall 41 and the peripheral wall 16 so as to be separated from the outer peripheral wall 41 and away from the peripheral wall 16. The protective plate 71 is attached to an additional straightening vane 72. The additional straightening vane 72 is arranged at a position above the above-mentioned second straightening vane 61. The additional straightening vane 72 is provided with a through hole. Specifically, the additional straightening vane 72 so that the diluted air AD circulates in the gap between the protective plate 71 and the outer peripheral wall 41 and also in the gap between the protective plate 71 and the peripheral wall 16. Is provided with a through hole. With this configuration, the heat of the protective plate 71 is suppressed from being transferred to the outer peripheral wall 41, and the thermal deformation of the outer peripheral wall 41 is suppressed.

-In the present embodiment, in the downstream wall 17, the discharge port 33 may be configured as an annular slit centered on the axis LG.
For example, as shown in FIGS. 17 and 18, the downstream wall 17 of the main body 10 includes a first annular slit 74, a second annular slit 75, and a third annular slit 76. Specifically, the downstream wall 17 is divided into an upper member 77, an intermediate member 78, and a lower member 79.

The upper member 77 has a central portion 77c and an inclined portion 77s provided around the central portion 77c and spread downward. The intermediate member 78 is configured as a ring body whose diameter is expanded downward. The lower member 79 is configured as a ring body whose diameter is expanded downward. The upper member 77, the intermediate member 78, and the lower member 79 are connected by one or a plurality of connecting members 80.

The upper member 77 is arranged above the intermediate member 78 so as to provide a gap constituting the first annular slit 74. The intermediate member 78 is arranged above the lower member 79 so as to provide a gap constituting the second annular slit 75. The lower member 79 is arranged above the peripheral wall 16 so as to provide a gap constituting the third annular slit 76. By making the discharge port 33 such an annular slit, the structure of the downstream wall 17 can be simplified, and the productivity of the downstream wall 17 can be improved.

The lower end 77b of the upper member 77 is located outside the radial DR with respect to the upper end 78a of the intermediate member 78. The lower end 78b of the intermediate member 78 is located outside the radial DR with respect to the upper end 79a of the lower member 79. The lower end 79b of the lower member 79 is located at the same position as the upper end 16a of the peripheral wall 16 in the radial DR or outside the radial DR. In the present embodiment, the upper portion of the peripheral wall 16 is reduced in diameter upward. With such a configuration, the upper member 77, the intermediate member 78, and the lower member 79 can prevent rainwater entering from the exhaust pipe from entering the main body 10.

More preferably, the lower end 77b of the upper member 77, the lower end 78b of the intermediate member 78, and the lower end 79b of the lower member 79 are formed in a circular shape having a concentric axis centered on the axis LG. The diameter of the lower end 77b of the upper member 77 is smaller than the diameter of the lower end 78b of the intermediate member 78, the diameter of the lower end 78b of the intermediate member 78 is smaller than the diameter of the lower end 79b of the lower member 79, and the diameter of the lower end 79b of the lower member 79. The diameter of is smaller than the diameter of the body of the peripheral wall 16. In this way, the downstream wall 17 is configured to have a shape similar to a truncated cone as a whole. As a result, for the mixed gas GM, the difference between the discharge amount on the downstream side and the discharge amount on the upstream side in the downstream wall 17 can be reduced.

AB ... Combustion air AD ... Diluted air GB ... Combustion gas GF ... Fuel gas GM ... Mixed gas LG ... Axis (central axis)
1 ... Gas combustion device 2 ... Burner 3 ... Furnace 4 ... Combustion chamber 10 ... Main body 11 ... Passage 12 ... Mixing section 15 ... Upstream wall 17 ... Downstream wall 20 ... Burning port 21 ... First air supply port 25 ... Second Air supply port 31 ... Central part 33 ... Discharge port

Claims (5)

It is provided with a burner and a furnace body that burns the fuel gas supplied from the burner and the combustion air to generate combustion gas.
The furnace body has a main body portion constituting a combustion chamber, and has a main body portion.
The main body portion connects an upstream wall provided on the upstream side of the combustion chamber, a downstream wall provided on the downstream side of the combustion chamber, and the upstream wall and the downstream wall so as to cover the periphery of the combustion chamber. Equipped with a peripheral wall,
The upstream wall has a fire port and a plurality of air supply ports arranged around the fire port to supply diluted air to the combustion chamber.
The downstream wall is a gas combustion device having at least one discharge port for discharging a mixed gas in which the diluted air and the combustion gas are mixed. The gas combustion apparatus according to claim 1, wherein the main body includes a first air supply port as the air supply port and a second air supply port provided on the peripheral wall to supply diluted air to the combustion chamber. .. The furnace body further includes a passage portion provided so as to surround at least a part of the peripheral wall and the upstream wall of the main body portion and configured to allow the diluted air to pass therethrough.
The gas combustion device according to claim 2, wherein the passage portion is connected to the first air supply port. The gas combustion apparatus according to any one of claims 1 to 3, further comprising a mixing unit for mixing the mixed gas discharged from the discharge port and diluted air. The downstream wall is configured such that the central portion intersecting the central axis of the burner projects downstream.
The downstream wall is provided with the plurality of outlets.
The gas combustion device according to claim 4, wherein the plurality of outlets are arranged in the circumferential direction of a virtual circle about the central axis, and each of the plurality of outlets opens in the radial direction.

Images