Hydrogen combustion type duct burner

Abstract

To suppress thermal damage due to glowing (abnormal overheating) of a burner component caused by hydrogen combustion.SOLUTION: A hydrogen combustion type duct burner 20 includes: a hydrogen ejection header 22 for ejecting hydrogen gas from a hydrogen ejection port 24A to a flame holding space R; a pair of air ejection plates 34 disposed to extend from both sides sandwiching the hydrogen ejection port 24A of the hydrogen ejection header 22 so that an opening at a downstream end of the flame holding space R expands to an ejecting direction of the hydrogen gas; air ejection nozzles 36 that are provided in the pair of air ejection plates 34, respectively and eject air to the flame holding space R; a pair of side plates 40 that constitute part of an inner wall of the flame holding space R and couple the pair of air ejection plates 34 to each other; and a pair of closing plates 44 each covering an end part of the opening continuing from the pair of side plates 40 and disposed to overlap with an extension line in the air ejecting direction from at least one of the air ejection nozzles 36.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this application relates to a hydrogen-fired duct burner. [Background technology]

[0002] Conventionally, a duct burner has been used that supplies hot air by arranging a hot air generating burner in a duct. The duct burner has a fuel ejection header, an air ejection plate, and a side plate (see Patent Document 1).

[0003] In recent years, hydrogen gas has been attracting attention as a decarbonized fuel, but hydrogen gas has a faster combustion speed and a higher flame temperature than city gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-286282 A Summary of the Invention [Problem to be solved by the invention]

[0005] When hydrogen gas is used as fuel for a duct burner as in Patent Document 1, the flame is likely to cause the burner parts to glow red (abnormally overheat), which can result in thermal damage and deterioration of the burner parts.

[0006] In consideration of the above, the present disclosure has an object to provide a hydrogen-fired duct burner that suppresses thermal damage to burner parts due to red heat caused by hydrogen combustion. [Means for solving the problem]

[0007] The hydrogen-fired duct burner of the first embodiment comprises a hydrogen injection header which injects hydrogen gas from a hydrogen outlet into a flame-holding space, a pair of air injection plates extending from both sides of the hydrogen outlet of the hydrogen injection header so that the opening at the downstream end of the flame-holding space widens in the direction of hydrogen gas injection, an air injection nozzle provided on each of the pair of air injection plates which injects air into the flame-holding space, a pair of side plates which extend in the direction of hydrogen gas injection to form part of the inner wall of the flame-holding space and connect the pair of air injection plates, and a pair of closure plates which cover the ends of the opening continuing from the pair of side plates and are arranged so as to overlap with an extension line in the air injection direction from at least one of the air injection nozzles.

[0008] The hydrogen-fired duct burner of the first embodiment has a hydrogen ejection header that ejects hydrogen gas from a hydrogen ejection port into a flame-holding space, and a pair of air ejection plates are arranged to extend from both sides of the hydrogen ejection port so that the opening widens in the ejection direction of the hydrogen gas. Each of the pair of air ejection plates is formed with an air ejection nozzle that ejects air into the flame-holding space. Also, side plates that form part of the inner wall of the flame-holding space are provided to connect the pair of air ejection plates. Furthermore, a pair of closure plates are provided to cover the ends of the opening continuing from the pair of side plates.

[0009] Hydrogen gas is ejected from the hydrogen nozzle into the flame holding space, and air is ejected from the air ejection nozzle into the flame holding space. The hydrogen gas and air are mixed, and the hydrogen gas burns in the flame holding space. The closure plate is arranged so as to overlap with an extension line of the air ejection direction from at least one air ejection nozzle, so that the air ejected from the air ejection nozzle hits the closure plate and creates a flow that returns to the upstream side of the flame holding space along the side plate. This air flow suppresses the temperature rise of the side plate, and makes it possible to suppress thermal damage caused by hydrogen combustion.

[0010] A hydrogen-fired duct burner of a second aspect is the hydrogen-fired duct burner of the first aspect, wherein the closure plate is arranged so as not to overlap with an extension line of the hydrogen ejection direction from the hydrogen ejection port.

[0011] According to the hydrogen combustion duct burner of the second aspect, the hydrogen gas ejected from the hydrogen ejection port does not directly hit the closure plate, so that it is possible to suppress a temperature rise of the side plate due to the flame caused by hydrogen gas combustion.

[0012] The hydrogen-fired duct burner of the third aspect is the hydrogen-fired duct burner of the first or second aspect, wherein at least 1 / 10 of each of both longitudinal ends of the hydrogen ejection header is made into a hydrogen non-ejection portion where the hydrogen ejection port is not formed.

[0013] According to the third embodiment of the hydrogen-fired duct burner, a non-hydrogen ejection portion is formed at the longitudinal end of the hydrogen ejection header, so that the flame caused by hydrogen gas combustion is formed at a position away from the side plate, thereby suppressing the temperature rise of the side plate.

[0014] The hydrogen-fired duct burner of the fourth aspect is a hydrogen-fired duct burner of any one of the first to third aspects, wherein at least 3 / 5 of the area of ​​the air ejection plate upstream of the hydrogen gas ejection is an air non-ejection section in which the air ejection nozzle is not formed.

[0015] In the hydrogen combustion duct burner of the fourth aspect, air is not ejected from the upstream 3 / 5 region of the air ejection plate from which hydrogen gas is ejected, so the position of hydrogen gas combustion can be shifted to the outside of the opening. This suppresses temperature rises in the hydrogen ejection header, the pair of air ejection plates, and the pair of side plates, and suppresses thermal damage caused by hydrogen combustion. Effect of the Invention

[0016] According to the present disclosure, it is possible to suppress thermal damage caused by red heat (abnormal overheating) of burner parts due to hydrogen combustion. [Brief description of the drawings]

[0017] [Figure 1] 1 is a diagram showing a schematic configuration of a hot air drying system using a hydrogen combustion hot air burner of this embodiment. [Diagram 2] FIG. 2 is a perspective view of the hydrogen combustion hot air burner of the present embodiment. [Diagram 3] FIG. 2 is a front view of the hydrogen combustion hot air burner of the present embodiment. [Figure 4] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Diagram 5] FIG. 3 is a cross-sectional view taken along line BB in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0019] 1 shows a schematic configuration of a hot air drying system 10 using a hydrogen combustion type hot air burner 20 of this embodiment. The hot air drying system 10 includes a drying furnace 12 and a circulation duct 14. Hot air generated by the hydrogen combustion type hot air burner 20 is supplied to the drying furnace 12, and hot air drying is performed on the material to be dried inside the furnace. An exhaust path 12A is connected to the drying furnace 12, and some of the gas inside the furnace is exhausted.

[0020] The circulation duct 14 constitutes a path through which the gas circulates inside the drying furnace 12. The gas G inside the circulation duct 14 is circulated by a circulation fan (not shown). A hydrogen combustion type hot air burner 20 is disposed inside the circulation duct 14 on the upstream side of the drying furnace 12.

[0021] The hydrogen combustion hot air burner 20 burns hydrogen gas with oxygen in the air and ejects the combustion gas produced by this combustion to generate hot air. The hydrogen combustion hot air burner 20 is equipped with a hydrogen ejection header 22 and an air ejection tube 30. A hydrogen gas supply pipe P1 is connected to the hydrogen ejection header 22, and hydrogen gas is supplied from the hydrogen gas supply pipe P1 to the hydrogen ejection header 22. An air supply pipe P2 is connected to the air ejection tube 30, and air is supplied from the air supply pipe P2 to the air ejection tube 30.

[0022] The hydrogen ejection header 22 is disposed inside the air ejection tube 30, and as shown in FIG. 2 and FIG. 3, a rectangular hydrogen ejection plate 24 is disposed on the hydrogen ejection side. The hydrogen ejection plate 24 has a plurality of hydrogen ejection holes 24A formed in a row in the longitudinal direction. The hydrogen ejection holes 24A are not formed at both ends of the hydrogen ejection plate 24 in the longitudinal direction. This portion of the hydrogen ejection plate 24 where the hydrogen ejection holes 24A are not formed is referred to as the "hydrogen non-ejection portion 26." The longitudinal length S1 of the hydrogen non-ejection portion 26 is preferably 1 / 10 or more and 3 / 8 or less of the overall longitudinal length S0 of the hydrogen ejection plate 24. This allows hydrogen gas to be ejected from the center away from a pair of side plates 40, which will be described later. In this embodiment, the longitudinal length S1 of the hydrogen non-ejection portion 26 is about 1 / 4 of the overall longitudinal length S0 of the hydrogen ejection plate 24.

[0023] As shown in Fig. 2, the air ejection tube 30 has a box-shaped outer wall 32 with one side open, and the hydrogen ejection header 22 is disposed inside away from the outer wall 32. A pair of air ejection plates 34 are disposed extending outward in the ejection direction of hydrogen gas from the upper and lower sides of the hydrogen ejection port 24A of the hydrogen ejection plate 24 (hydrogen ejection header 22). The pair of air ejection plates 34 are disposed such that the distance between them increases as they move outward in the ejection direction of hydrogen gas. At the extending tip of each of the pair of air ejection plates 34, a flange portion 35 is formed which is bent upward and downward, respectively. The upper and lower ends of the flange portion 35 are connected to the outer wall 32.

[0024] A pair of side plates 40 are disposed to extend outward in the direction of hydrogen gas ejection from both left and right ends of the hydrogen ejection port 24A of the hydrogen ejection plate 24 (hydrogen ejection header 22).

[0025] Inside the air ejection tube 30, an air chamber 31 is formed, which is partitioned by an outer wall 32, a hydrogen ejection header 22, a pair of air ejection plates 34, and a pair of side plates 40. Inside the air ejection tube 30, on the hydrogen gas ejection outer side of the hydrogen ejection plate 24, a flame holding space R is formed, surrounded by the pair of air ejection plates 34 and the pair of side plates 40. The flame holding space R gradually widens in the vertical direction toward the outside in the hydrogen gas ejection direction, and an opening R0 is formed that opens to the outside of the air ejection tube 30. The opening R0 is the downstream end of the flame holding space R. Being surrounded from the outside, the flame holding space R has the function of maintaining the flame and also guides the flame in the ejection direction of the hydrogen gas.

[0026] The upper air ejection plate 34A of the pair of air ejection plates 34 is formed with a plurality of upper air ejection nozzles 36A that eject air from the air chamber 31 into the flame holding space R. In this embodiment, the plurality of upper air ejection nozzles 36A are formed in two rows in the extension direction of the upper air ejection plate 34A, with 12 nozzles lined up in the left-right direction.

[0027] As shown in FIG. 3, the upper air ejection nozzle 36A is formed only on the opening R0 side in the extension direction of the upper air ejection plate 34A, and is not formed on the hydrogen ejection plate 24 side. This part of the upper air ejection plate 34A where the upper air ejection nozzle 36A is not formed is called the "non-air ejection part 38A". The length L1 in the extension direction of the non-air ejection part 38A is preferably 3 / 5 or more and 4 / 5 or less of the entire length L0 in the extension direction of the upper air ejection plate 34A. This prevents air from being ejected from the back side of the flame holding space R (the hydrogen ejection plate 24 side). In this embodiment, the length L1 in the extension direction of the non-air ejection part 38A is about 3 / 5 of the entire length L0 in the extension direction of the upper air ejection plate 34A exposed to the flame holding space R.

[0028] 5, the upper air ejection nozzle 36A is provided so that the air ejection direction D1 is inclined outward from the opening R0 with respect to the normal direction H of the plate surface of the upper air ejection plate 34A. That is, when the upper air ejection nozzle 36A is viewed from the left and right, the air ejection direction D1 is set at an inclination angle θ1 of less than 90° with respect to the plate surface of the upper air ejection plate 34A on the opening R0 side.

[0029] It is preferable that the air ejection direction D1 is set so that the lower air ejection plate 34B is not positioned on an extension line of the air ejection direction D1 of the central axis of the upper air ejection nozzle 36A, and the extension line extends outward from the opening R0. It is also preferable that the inclination angle θ1 is 30° or more and 60° or less. In this embodiment, the inclination angle θ1 of the air ejection direction D1 is 45°.

[0030] A plurality of lower air ejection nozzles 36B that eject air from the air chamber 31 to the flame holding space R are also formed in the lower air ejection plate 34B of the pair of air ejection plates 34. In this embodiment, the plurality of lower air ejection nozzles 36B are formed in two rows in the extension direction of the lower air ejection plate 34B, with 12 nozzles lined up in the left-right direction.

[0031] As shown in FIG. 2-4, the lower air ejection nozzle 36B is not formed on the hydrogen ejection plate 24 side in the extension direction of the lower air ejection plate 34B. This part of the lower air ejection plate 34B where the lower air ejection nozzle 36B is not formed is referred to as the "non-air ejection part 38B". The length L2 in the extension direction of the non-air ejection part 38B is preferably 3 / 5 or more and 4 / 5 or less of the entire length L0 in the extension direction of the lower air ejection plate 34B. This prevents air from being ejected from the back side (hydrogen ejection plate 24 side) of the flame holding space R. In this embodiment, the length L2 in the extension direction of the non-air ejection part 38B is about 3 / 5 of the entire length L0 in the extension direction of the lower air ejection plate 34B exposed to the flame holding space R.

[0032] 5, the lower air ejection nozzle 36B is provided such that the air ejection direction D2 is inclined toward the outside of the opening R0 with respect to the normal direction H of the plate surface of the lower air ejection plate 34B. That is, when the lower air ejection nozzle 36B is viewed from the left and right, the air ejection direction D2 is set at an inclination angle θ2 of less than 90° with respect to the plate surface of the lower air ejection plate 34B on the opening R0 side.

[0033] It is preferable that the air ejection direction D2 is set so that the upper air ejection plate 34A is not positioned on an extension line of the air ejection direction D2 of the central axis of the lower air ejection nozzle 36B, and the extension line extends outside the opening R0. It is also preferable that the inclination angle θ2 is 30° or more and 60° or less. In this embodiment, the inclination angle θ2 of the air ejection direction D2 is 45°.

[0034] A pair of plate-shaped blocking plates 44 are provided at the left and right ends of the opening R0 to cover a part of the opening R0. When viewed from the upstream side of hydrogen gas ejection, the right blocking plate 44A of the pair of blocking plates 44 is provided so as to cover the right end of the opening R0 when viewed from the upstream side of hydrogen gas ejection. When viewed from the opening R0 side, the right blocking plate 44A is disposed at a position that covers at least the upper air ejection nozzle 36A and the lower air ejection nozzle 36B formed at the left end. Also, when viewed from the opening R0 side, the right blocking plate 44A is disposed at a position that does not overlap with the hydrogen ejection port 24A (a position that does not cover the hydrogen ejection port 24A).

[0035] Furthermore, the left blocking plate 44B of the pair of blocking plates 44 is provided so as to cover the left end as viewed from the upstream side of the hydrogen gas ejection of the opening R0. The left blocking plate 44B is disposed in a position covering at least the upper air ejection nozzle 36A and the lower air ejection nozzle 36B formed at the right end as viewed from the opening R0 side. The left blocking plate 44B is disposed in a position not overlapping with the hydrogen ejection port 24A (a position not covering the hydrogen ejection port 24A) as viewed from the opening R0 side.

[0036] Next, the effects of this embodiment will be described.

[0037] The hot air drying system 10 operates by circulating gas in the circulation duct 14 while generating hot air from the hydrogen combustion type hot air burner 20. When hot air is generated by the hydrogen combustion type hot air burner 20, hydrogen gas is supplied from the hydrogen gas supply pipe P1 to the hydrogen ejection header 22, and air is supplied from the air supply pipe P2 to the air ejection tube 30, and ignition is performed by an ignition device (not shown).

[0038] The hydrogen gas is ejected from the hydrogen ejection nozzle 24A, and the air is ejected from the air ejection nozzle 36. The hydrogen gas and the air are mixed and combusted, and the combustion gas that has become hot air due to the combustion is supplied to the drying furnace 12 and is used for drying in the drying furnace 12.

[0039] In the hydrogen combustion hot air burner 20 of this embodiment, air is ejected from the upper air ejection nozzle 36A and the lower air ejection nozzle 36B toward the outside of the opening R0. Therefore, the air is mixed with the hydrogen gas ejected from the hydrogen ejection port 24A outside the flame holding space R from the positions where the upper air ejection nozzle 36A and the lower air ejection nozzle 36B are formed. This makes it possible to shift the combustion position of the hydrogen gas to the outside of the opening, and to suppress an excessive rise in temperature in the flame holding space R, compared to when the ejection direction of the air from the upper air ejection nozzle 36A and the lower air ejection nozzle 36B is normal to the plate surface of the air ejection plate 34.

[0040] In this embodiment, the upper air ejection nozzle 36A and the lower air ejection nozzle 36B are formed only on the opening R0 side in the extension direction of the upper air ejection plate 34A and the lower air ejection plate 34B, and non-air ejection sections 38A, 38B are provided. This makes it possible to shift the combustion position of hydrogen gas to the outside of the opening, and suppresses an excessive rise in temperature in the flame holding space R, compared to a case in which the upper air ejection nozzle 36A and the lower air ejection nozzle 36B are provided on the entire surface of the upper air ejection plate 34A and the lower air ejection plate 34B.

[0041] Furthermore, in this embodiment, the lower air ejection plate 34B is not disposed on an extension line of the air ejection direction D1 of the central axis of the upper air ejection nozzle 36A, and the upper air ejection plate 34A is not disposed on an extension line of the air ejection direction D2 of the central axis of the lower air ejection nozzle 36B. Therefore, the combustion flame of hydrogen gas is not directly blown onto the upper air ejection plate 34A and the lower air ejection plate 34B, and excessive temperature rise of the upper air ejection plate 34A and the lower air ejection plate 34B can be suppressed.

[0042] In this embodiment, the hydrogen outlet 24A is formed in the center of the hydrogen outlet plate 24, and hydrogen non-ejection sections 26 are provided at both longitudinal ends of the hydrogen outlet plate 24. This allows hydrogen gas to be ejected from a position away from the pair of side plates 40, making it possible to prevent an excessive temperature rise in the pair of side plates 40.

[0043] Furthermore, in this embodiment, a pair of blocking plates 44 are provided. The hydrogen outlet 24A does not overlap with the blocking plates 44, and the air ejected from the air ejection nozzles 36 provided at the left and right ends hits the blocking plates 44, so that the air that hits the blocking plates 44 returns upstream and an airflow is generated along the side plates 40. Therefore, excessive temperature rise in the vicinity of the side plates 40 can be suppressed.

[0044] In this embodiment, air non-ejection sections 38A, 38B where no air ejection nozzles are formed are formed on the upstream side of the hydrogen gas ejection of the upper air ejection plate 34A and the lower upper air ejection plate 34B, but it is not necessarily necessary to form the air non-ejection sections 38A, 38B.

[0045] In addition, in this embodiment, the upper air ejection nozzle 36A and the lower air ejection nozzle 36B are arranged so that the air ejection directions D1, D2 are inclined toward the outside of the opening R0 with respect to the plate surface, but the air ejection directions D1, D2 may be directed in the normal direction to the plate surface. [Explanation of symbols]

[0046] 20 Hydrogen-fired hot air burner 22 Hydrogen blowing header 24A Hydrogen nozzle 34 Air jet plate 36 Air jet nozzle 38A, 38B Non-air ejection section 40 Side Plate 44 Occlusion plate 44 R Flame holding space R0 opening (opening)

Claims

1. a hydrogen ejection header that ejects hydrogen gas from a hydrogen ejection port into a flame-holding space; a pair of air ejection plates extending from both sides of the hydrogen ejection header with respect to the hydrogen ejection port so that an opening at a downstream end of the flame stabilizing space widens in the ejection direction of the hydrogen gas; an air ejection nozzle provided on each of the pair of air ejection plates for ejecting air into the flame holding space; a pair of side plates extending in a direction in which the hydrogen gas is ejected, forming a part of an inner wall of the flame holding space, and connecting the pair of air ejection plates; A pair of closure plates that cover the ends of the openings that are continuous with the pair of side plates and are arranged to overlap with an extension line of an air ejection direction from at least one of the air ejection nozzles; A hydrogen combustion duct burner equipped with

2. 2. The hydrogen combustion duct burner according to claim 1, wherein the obturator plate is disposed so as not to overlap with an extension line of the hydrogen ejection direction from the hydrogen ejection port.

3. a region of at least 1 / 10 of each of both ends in the longitudinal direction of the hydrogen injection header is a hydrogen non-injection portion where the hydrogen injection port is not formed; 2. The hydrogen combustion duct burner according to claim 1.

4. At least 3 / 5 of the area of ​​the air ejection plate on the upstream side of the hydrogen gas ejection is an air non-ejection portion in which the air ejection nozzle is not formed.

2. The hydrogen combustion duct burner according to claim 1.

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