Gas burners and combustion equipment

Abstract

To easily control a combustion state when using gas fuel including hydrogen.SOLUTION: A gas burner for burning gas fuel including hydrogen includes: a nozzle for jetting gas fuel; a primary air flow passage part surrounding the periphery of the nozzle in front view visually recognized in the axial line direction of the nozzle and forming a primary air outlet from which primary air flows out; at least one secondary air flow passage part located on the upper side or lower side of the primary air outlet in front view and forming a secondary air outlet from which secondary air flows out, the secondary air outlet including an inner side outlet and an outer side outlet located more separate from the primary air outlet than the inner side outlet; and a flow rate control device capable of controlling each of an outflow amount of the secondary air flowing out from the inner side outlet and an outflow amount of the secondary air flowing out from the outer side outlet.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a gas burner and combustion equipment for burning gaseous fuels including hydrogen. [Background technology]

[0002] Combustion equipment such as boilers is equipped with burners that burn fuel, and there are known techniques for improving flame stability and suppressing the generation of nitrogen oxides (NOx) in order to achieve a favorable combustion state. For example, Patent Document 1 discloses a combustion burner that is arranged on the central axis of the nozzle and has a split-shaped flame stabilizer that widens toward the downstream side in the flow direction of the fuel gas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-149676 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, some combustion facilities are making efforts to move away from fossil fuels (decarbonization) with the aim of reducing emissions of carbon dioxide, a major greenhouse gas. One such decarbonization initiative is the use of gas fuel containing hydrogen as burner fuel. Hydrogen has properties that are significantly different from the components contained in conventional fuels (for example, methane contained in city gas, propane contained in LPG, and pulverized coal contained in the fuel gas described in Patent Document 1). However, the combustion burner described in Patent Document 1 is not configured to control the combustion state taking into account the properties of hydrogen. In other words, when a gas burner uses a gas fuel containing hydrogen, there is room for improvement of the gas burner.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a gas burner that can easily control the combustion state when using a gas fuel containing hydrogen. [Means for solving the problem]

[0006] In order to achieve the above object, the gas burner according to the present disclosure comprises: 1. A gas burner for burning a gas fuel containing hydrogen, comprising: a nozzle for ejecting the gas fuel; a primary air flow path portion that surrounds the nozzle in a front view seen along the axial direction of the nozzle and forms a primary air outlet through which the primary air flows out; at least one secondary air flow path portion that is located above or below the primary air outlet in the front view and that forms a secondary air outlet through which secondary air flows out, the secondary air outlet including an inner outlet and an outer outlet that is located farther from the primary air outlet than the inner outlet; and a flow rate adjusting device that adjusts the amount of secondary air flowing out from the inner outlet and the amount of secondary air flowing out from the outer outlet. [Effects of the Invention]

[0007] According to the gas burner of the present disclosure, the combustion state can be easily controlled when using a gas fuel containing hydrogen. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic configuration of a combustion facility according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing a schematic internal configuration of a furnace according to a first embodiment. [Figure 3] 1 is a view (front view) of a gas burner according to a first embodiment as seen from inside a furnace. [Figure 4] 1 is a diagram schematically showing the configuration of a gas burner according to a first embodiment. [Figure 5A]FIG. 2 illustrates a flow path for secondary air in a gas burner according to some embodiments. [Figure 5B] FIG. 2 illustrates a flow path for secondary air in a gas burner according to some embodiments. [Figure 6] FIG. 6 is a diagram schematically showing the configuration of a gas burner according to a second embodiment. [Figure 7] FIG. 10 is a diagram illustrating the layout of an inner outlet according to some embodiments. [Figure 8] FIG. 10 is a diagram schematically showing the configuration of a gas burner according to a third embodiment. [Figure 9A] 1A and 1B are diagrams illustrating a schematic configuration of a first adjustment device according to some embodiments. [Figure 9B] 10A and 10B are diagrams illustrating a schematic configuration of a second adjustment device according to some embodiments. [Figure 10] FIG. 1 is a system diagram illustrating an automation system for a combustion facility according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a gas burner according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment shows one aspect of the present disclosure, but does not limit the present disclosure and can be modified as desired within the scope of the technical concept of the present disclosure.

[0010] First Embodiment (Combustion equipment configuration) FIG. 1 is a diagram schematically illustrating the configuration of a combustion facility 1 according to a first embodiment. As illustrated in FIG. 1, the combustion facility 1 includes a furnace 2 and a gas burner 4 that is provided in the furnace 2 and that burns a gas fuel F containing hydrogen in the furnace 2. The combustion facility 1 is, for example, a boiler that generates a flame X and burns the gas fuel F ejected from the gas burner 4 into the furnace 2 to generate high-temperature exhaust gas G, and then generates steam by recovering heat from the high-temperature exhaust gas G. The heat of the exhaust gas G may be recovered by a heat exchanger provided in the furnace 2 or by a heat exchanger provided outside the furnace 2.

[0011] In this disclosure, "hydrogen-containing gas fuel F" includes those containing hydrogen and fuels other than hydrogen (mixed combustion) and those containing only hydrogen (monocarbon combustion). Furthermore, even those containing hydrogen and fuels other than hydrogen can be classified as fuels where hydrogen is the main component (volume ratio of hydrogen is 50% or more) and fuels where a fuel other than hydrogen is the main component (volume ratio of hydrogen is less than 50%). "Hydrogen-containing gas fuel" includes all of these cases.

[0012] The configuration of the furnace 2 will now be described. Fig. 2 is a diagram schematically illustrating the internal configuration of the furnace 2 according to the first embodiment, as viewed from the vertical direction. In the first embodiment, the furnace 2 has a rectangular cylindrical shape with its longitudinal direction along the vertical direction. As illustrated in Fig. 2, the furnace 2 is formed with a combustion space 6 for combusting the gas fuel F ejected from the gas burner 4. The combustion space 6 of the furnace 2 has a rectangular shape.

[0013] The furnace 2 includes a first furnace wall 8 including a first inner circumferential surface 7a that corresponds to one side of the rectangular combustion space 6 among the inner circumferential surfaces 7 of the furnace 2, a second furnace wall 10 located on the opposite side of the first furnace wall 8 across the combustion space 6, a third furnace wall 12 connecting one end 16 of the first furnace wall 8 to one end 18 of the second furnace wall 10, and a fourth furnace wall 14 connecting the other end 17 of the first furnace wall 8 to the other end 19 of the second furnace wall 10. The third furnace wall 12 is located on the opposite side of the fourth furnace wall 14 across the combustion space 6. The combustion space 6 of the furnace 2 is formed into a rectangular shape by being surrounded by the first furnace wall 8, the second furnace wall 10, the third furnace wall 12, and the fourth furnace wall 14.

[0014] In the first embodiment, as illustrated in Fig. 2, the furnace 2 is provided with a plurality of gas burners 4. The plurality of gas burners 4 includes a first gas burner 4A(4) provided on the first furnace wall 8 so as to be closer to the fourth furnace wall 14 than the third furnace wall 12, a second gas burner 4B(4) provided on the second furnace wall 10 so as to be closer to the third furnace wall 12 than the fourth furnace wall 14, a third gas burner 4C(4) provided on the third furnace wall 12 so as to be closer to the first furnace wall 8 than the second furnace wall 10, and a fourth gas burner 4D(4) provided on the fourth furnace wall 14 so as to be closer to the second furnace wall 10 than the first furnace wall 8. Each of the plurality of gas burners 4 ejects gas fuel F toward a rectangular corner 21 of the combustion space 6. Although not shown, the plurality of gas burners 4 may further include an upper gas burner stacked on the first gas burner 4A.

[0015] The gas burner 4 combusts a gas fuel F. In the first embodiment, as illustrated in Fig. 1 , the combustion equipment 1 further includes a gas fuel supply device 100 that supplies the gas fuel F to the gas burner 4, and an air supply device 102 that supplies combustion air A to the gas burner 4. The gas burner 4 mixes the gas fuel F supplied from the gas fuel supply device 100 with the combustion air A supplied from the air supply device 102, and sprays the mixture into the furnace 2 (combustion space 6), thereby combusting the gas fuel F.

[0016] The gas fuel supply device 100 includes a gas tank 104 in which gas fuel F is stored, and a fuel supply line 106 that connects the gas tank 104 to the gas burner 4 and allows the gas fuel F stored in the gas tank 104 to flow toward the gas burner 4.

[0017] The air supply device 102 includes an air supply line 108 having one end open to the atmosphere and the other end connected to the gas burner 4, and a blower 110 provided on the air supply line 108 for blowing air taken in from one end of the air supply line 108 to the furnace 2 as combustion air A.

[0018] (Gas burner configuration) The configuration of the gas burner 4 will be specifically described. Fig. 3 is a view (front view) of the gas burner 4 according to the first embodiment as viewed from the combustion space 6 side of the furnace 2. Fig. 4 is a diagram schematically showing the configuration of the gas burner 4 according to the first embodiment.

[0019] In the first embodiment, as illustrated in Fig. 3, the gas burner 4 is a rectangular burner having an end face 5 facing the combustion space 6 of the furnace 2, the longitudinal direction of which is along the vertical direction D2. As illustrated in Fig. 4, the gas burner 4 includes a nozzle 20, a primary air passage section 22, a secondary air passage section 24, and a flow rate regulator 25.

[0020] The nozzle 20 injects the gas fuel F supplied from the gas fuel supply device 100 into the combustion space 6 of the furnace 2. The nozzle 20 has, for example, a cylindrical shape centered on an axis O so that the gas fuel F can flow through it. In the first embodiment, the nozzle 20 is supplied with the gas fuel F from the gas fuel supply device 100 via a burner body 26 having a cylindrical shape.

[0021] 3, the primary air flow path section 22 surrounds the periphery of the nozzle 20 in a front view seen along the axial direction D1 of the nozzle 20 (hereinafter referred to as "front view"). The primary air flow path section 22 forms a primary air outlet 36 through which combustion air A supplied from the air supply device 102 flows out as primary air A1.

[0022] 4, the primary air flow path section 22 includes a primary air flow path 38 through which primary air A1 supplied from the air supply device 102 flows. The primary air flow path section 22 (sleeve) has a cylindrical shape and extends along the axial direction D1 of the nozzle 20. The inner diameter of the primary air flow path section 22 is larger than the outer diameter of the nozzle 20, and the nozzle 20 is disposed within the primary air flow path section 22. In other words, the primary air flow path section 22 includes a primary air flow path 38 through which the primary air A1 flows between the inner wall surface of the primary air flow path section 22 and the outer wall surface of the nozzle 20. In other words, the primary air flow path 38 is formed on the outer periphery of the nozzle 20.

[0023] In the first embodiment, the gas burner 4 includes a flame stabilizer 55 provided at the outlet of the primary air flow path 38 mainly for the purpose of flame stabilization. The primary air A1 flowing through the primary air flow path 38 is a straight flow, but the flame stabilizer 55 is configured to impart a swirling force to a part or all of the primary air A1.

[0024] As illustrated in Figure 3, the secondary air flow path section 24 is located above or below the primary air outlet 36 when viewed from the front, and forms a secondary air outlet 40 through which secondary air A2 flows out, which is brought into contact with the gas fuel F later than the primary air A1.

[0025] In the first embodiment, the gas burner 4 includes a pair of secondary air flow path sections 24 arranged on either side of the primary air flow path section 22 in the vertical direction D2. The pair of secondary air flow path sections 24 includes an upper secondary air flow path section 24A (24) and a lower secondary air flow path section 24B (24). The secondary air outlet 40A (40) of the upper secondary air flow path section 24A is located above the primary air outlet 36. In the left-right direction D3, the primary air outlet 36 and the secondary air outlet 40A of the upper secondary air flow path section 24A at least partially overlap each other. The secondary air outlet 40B (40) of the lower secondary air flow path section 24B is located below the primary air outlet 36. In the left-right direction D3, the primary air outlet 36 and the secondary air outlet 40B of the lower secondary air flow path section 24B at least partially overlap each other. The secondary air outlet 40A of the upper secondary air flow path section 24A is located on the opposite side of the primary air outlet 36 from the secondary air outlet 40B of the lower secondary air flow path section 24B.

[0026] As illustrated in FIG. 3 , the secondary air outlet 40 includes an inner outlet 42 and an outer outlet 44 located farther away from the primary air outlet 36 than the inner outlet 42. In a radial direction centered on the axis O of the nozzle 20, the outer outlet 44 is located radially outward of the inner outlet 42. In the first embodiment, the secondary air outlet 40A of the upper secondary air flow path section 24A includes an inner outlet 42A (42) and an outer outlet 44A (44). The secondary air outlet 40B of the lower secondary air flow path section 24B includes an inner outlet 42B (42) and an outer outlet 44B (44). As illustrated in FIG. 3 , the outer outlet 44A of the secondary air outlet 40A, the inner outlet 42A of the secondary air outlet 40A, the primary air outlet 36, the inner outlet 42B of the secondary air outlet 40B, and the outer outlet 44B of the secondary air outlet 40B are arranged in this order from top to bottom in a front view.

[0027] Each of the inner outlet 42 and the outer outlet 44 is configured so that secondary air A2 flows out. Specifically, as illustrated in Fig. 4, the secondary air flow path section 24 includes an inner secondary air flow path 28 and an outer secondary air flow path 30 formed therein. The inner secondary air flow path 28 receives combustion air A supplied from an air supply device 102 and includes an inner outlet 42 at one end. The outer secondary air flow path 30 receives combustion air A supplied from the air supply device 102 and includes an outer outlet 44 at one end. The inner outlet 42 and the outer outlet 44 allow the combustion air A to flow out as secondary air A2 into the combustion space 6 of the furnace 2.

[0028] Hereinafter, the inner secondary air flow path 28 of the upper secondary air flow path section 24A according to the first embodiment will be referred to as a first flow path 28A (28), and the outer secondary air flow path 30 of the upper secondary air flow path section 24A will be referred to as a second flow path 30A (30). Similarly, the inner secondary air flow path 28 of the lower secondary air flow path section 24B according to the first embodiment will be referred to as a third flow path 28B (28), and the outer secondary air flow path 30 of the lower secondary air flow path section 24B will be referred to as a fourth flow path 30B (30).

[0029] The flow rate adjustment device 25 is configured to adjust the amount of secondary air A2 flowing out from the inner outlet 42 and the amount of secondary air A2 flowing out from the outer outlet 44. In the first embodiment, as illustrated in FIG. 4 , the flow rate adjustment device 25 includes a first valve 46 provided in the first flow path 28, a second valve 48 provided in the second flow path 30A, a third valve 50 provided in the third flow path 28B, and a fourth valve 52 provided in the fourth flow path 30B. By adjusting the aperture of the first valve 46, the amount of secondary air A2 flowing through the first flow path 28A is adjusted. By adjusting the aperture of the second valve 48, the amount of secondary air A2 flowing through the second flow path 30A is adjusted. By adjusting the aperture of the third valve 50, the amount of secondary air A2 flowing through the third flow path 28B is adjusted. By adjusting the aperture of the fourth valve 52, the amount of secondary air A2 flowing through the fourth flow path 30B is adjusted.

[0030] (Actions and Effects) The operation and effect of the gas burner 4 according to the first embodiment will be described. According to the first embodiment, the outer outlet 44 is located farther outward in the radial direction of the nozzle 20 from the primary air outlet 36 than the inner outlet 42, so that the secondary air A2 flowing out from the inner outlet 42 can be used for flame stabilization, and the secondary air A2 flowing out from the outer outlet 44 can be used for promoting slow combustion. As illustrated in FIG. 4, the gas burner 4 according to the present disclosure is equipped with a flow rate adjusting device 25, so that it is possible to improve flame stabilization or promote slow combustion depending on the combustion state. Therefore, the combustion state can be easily controlled.

[0031] In the first embodiment, the flow rate adjustment device 25 includes the first valve 46, the second valve 48, the third valve 50, and the fourth valve 52, but the present disclosure is not limited to this embodiment as long as it is configured to be able to adjust each of the outflow rate of the secondary air A2 flowing out from the inner outlet 42 and the outflow rate of the secondary air A2 flowing out from the outer outlet 44. Furthermore, the present disclosure does not limit the flow rate adjustment device 25 to a valve, and may include, for example, a blower.

[0032] FIG. 5A is a diagram showing the flow path of the secondary air A2 in a gas burner 4 according to some embodiments. FIG. 5A illustrates the flow path of the secondary air A2 flowing out of the inner outlet 42. In some embodiments, as illustrated in FIG. 5A , the gas burner 4 includes an inner air line 54 through which the secondary air A2 flows, the inner air line 54 including a branch point 56 branching into either the first flow path 28A or the third flow path 28B. A fifth valve 58 is provided in the inner air line 54 upstream of the branch point 56 in the flow direction of the secondary air A2. By adjusting the aperture of the fifth valve 58, the amount of secondary air A2 flowing through the first flow path 28A and the amount of secondary air A2 flowing through the third flow path 28B are simultaneously adjusted. This configuration eliminates the need for the first valve 46 and the third valve 50. In some embodiments, the air supply line 108 of the air supply device 102 includes the inner air line 54.

[0033] FIG. 5B is a diagram showing the flow path of the secondary air A2 in the gas burner 4 according to some embodiments. FIG. 5B illustrates the flow path of the secondary air A2 flowing out of the outer outlet 44. In some embodiments, as illustrated in FIG. 5B , the gas burner 4 includes an outer air line 60 through which the secondary air A2 flows, the outer air line 60 including a branch point 62 branching into either the second flow path 30A or the fourth flow path 30B. A sixth valve 64 is provided in the outer air line 60 upstream of the branch point 62 in the flow direction of the secondary air A2. By adjusting the aperture of the sixth valve 64, the amount of secondary air A2 flowing through the second flow path 30A and the amount of secondary air A2 flowing through the fourth flow path 30B are simultaneously adjusted. This configuration eliminates the need for the second valve 48 and the fourth valve 52. In some embodiments, the air supply line 108 of the air supply device 102 includes the outer air line 60.

[0034] Second Embodiment A gas burner 4 according to a second embodiment of the present disclosure will now be described. The second embodiment differs from the first embodiment in that low-oxygen secondary air A21 is configured to flow out from an inner outlet 42. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0035] Fig. 6 is a diagram schematically showing the configuration of a gas burner 4 according to the second embodiment. In the second embodiment, as shown in Fig. 6, the inner outlet 42 is configured to allow low-oxygen secondary air A21 (A2) having a lower oxygen concentration than the secondary air A2 flowing out from the outer outlet 44 to flow out.

[0036] 6, the gas burner 4 includes a circulation line 70 for mixing a portion of the exhaust gas G (circulation gas Eg) discharged from the furnace 2 with the combustion air A (secondary air A2) supplied from the air supply device 102 to the inner secondary air flow path 28. As described above, in the second embodiment, the gas burner 4 generates low-oxygen secondary air A21 by mixing the circulation gas Eg with the secondary air A2. Note that in some embodiments, the circulation line 70 is connected to the inner secondary air flow path 28, and the circulation gas Eg is mixed with the secondary air A2 flowing through the inner secondary air flow path 28.

[0037] Although not shown, in some embodiments, the gas burner 4 includes a circulation gas amount regulator that is provided in the circulation line 70 and is capable of adjusting the amount of the circulation gas Eg flowing through the circulation line 70. The circulation gas amount regulator may be a valve or a blower. With this configuration, the amount of oxygen contained in the low-oxygen secondary air A21 can be adjusted depending on the combustion state.

[0038] The operation and effects of the gas burner 4 according to the second embodiment will be described. Hydrogen has a higher combustion rate compared to the components contained in conventional gas fuels. Therefore, since the mixing of hydrogen and oxygen is rapidly carried out, the temperature in the combustion space 6 quickly rises, promoting the generation of nitrogen oxides (NOx). In contrast, according to the second embodiment, the low-oxygen secondary air A21 flowing out from the inner outlet 42 can be brought into contact with the gas fuel F prior to the secondary air A2 flowing out from the outer outlet 44. For this reason, the mixing of hydrogen and oxygen can be slowed down, and the temperature rise in the combustion space 6 can be suppressed. Thus, the generation of NOx can be further suppressed.

[0039] FIG. 7 is a diagram for explaining the layout of the inner outlet 42 according to some embodiments. As illustrated in FIG. 7, in a front view, a virtual line 80 is linearly extended along the vertical direction D2 from the axis O of the nozzle 20. The point where this virtual line 80 intersects the periphery of the primary air outlet 36 is defined as the first intersection point 82. Further, the point where this virtual line 80 first intersects the periphery of the inner outlet 42 is defined as the second intersection point 84. When the distance between the first intersection point 82 and the axis O of the nozzle 20 is r, and the distance between the second intersection point 84 and the axis O of the nozzle 20 is d, 1.5×r≦d≦5×r is satisfied.

[0040] As described above, hydrogen has a higher combustion rate compared to the components contained in conventional gas fuels. For this reason, even if the inner outlet 42 is separated from the axis O of the nozzle 20 so as to satisfy 1.5×r≦d, flame holding by the secondary air A2 (or low-oxygen secondary air A21) flowing out from the inner outlet 42 can be achieved. Further, by satisfying 1.5×r≦d, the contact between the secondary air A2 flowing out from the outer outlet 44 and the gas fuel F can be delayed, promoting slow combustion. On the other hand, when 5×r<d is satisfied, it becomes difficult to achieve flame holding by the secondary air A2 (or low-oxygen secondary air A21) flowing out from the inner outlet 42, and at the same time, the delay in the timing of the supplied secondary air A2 (or low-oxygen secondary air A21) is large, and it becomes difficult to maintain an appropriate combustion state by controlling the flow rate of the secondary air A2 (or low-oxygen secondary air A21).

[0041] According to the configuration illustrated in Figure 7, the inner outlet 42 is spaced from the axis O of the nozzle 20 so as to satisfy 1.5 x r < d < 5 x r, so that flame stabilization is achieved by the secondary air A2 (or low-oxygen secondary air A21) flowing out of the inner outlet 42, while delaying contact between the secondary air A2 flowing out of the outer outlet 44 and the gas fuel F, thereby promoting slow combustion.

[0042] Third Embodiment A gas burner 4 according to a third embodiment of the present disclosure will be described. The third embodiment differs from the second embodiment in that it further includes a first adjustment device 86 and a second adjustment device 88. In the third embodiment, the same components as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0043] Fig. 8 is a diagram schematically showing the configuration of a gas burner 4 according to the third embodiment. In the third embodiment, as shown in Fig. 8, the gas burner 4 further includes a first adjustment device 86 and a second adjustment device 88.

[0044] 8, the upper secondary air flow path section 24A has an inner swing section 90A (90) that includes the inner outlet 42A. Similarly, the lower secondary air flow path section 24B has an inner swing section 90B (90) that includes the inner outlet 42B. The inner swing section 90 has a cylindrical shape and its diameter decreases toward the combustion space 6. The inner swing section 90 has a fixed end on the opposite side to the combustion space 6 in the axial direction D1 and a rotating end on the combustion space 6 side, and is configured to be rotatable (swingable) along the vertical direction D2.

[0045] 8, the upper secondary air flow path section 24A has an outer swing section 94A (94) that includes the outer outlet 44A. Similarly, the lower secondary air flow path section 24B has an outer swing section 94B (94) that includes the outer outlet 44B. The outer swing section 94 has a cylindrical shape and its diameter decreases toward the combustion space 6. The outer swing section 94 has a fixed end on the opposite side to the combustion space 6 in the axial direction D1 and a rotating end on the combustion space 6 side, and is configured to be rotatable (swingable) along the vertical direction D2.

[0046] The first adjustment device 86 is configured to be able to simultaneously adjust the orientation of the inner outlet 42A of the upper secondary air flow path section 24A and the inner outlet 42B of the lower secondary air flow path section 24B. In the embodiment illustrated in Fig. 8, the first adjustment device 86 includes a first angle setting unit 91 and a first transmission unit 92. Note that in Fig. 8, the first transmission unit 92 is illustrated by a dotted line.

[0047] The first angle setting unit 91 is a device for setting the rotation angle (tilt angle) of the inner swing unit 90 and is, for example, a handle. The first transmission unit 92 connects the first angle setting unit 91 to the inner swing unit 90A of the upper secondary air flow path unit 24A, and also connects the first angle setting unit 91 to the inner swing unit 90B of the lower secondary air flow path unit 24B. The first transmission unit 92 is, for example, a rod-shaped member.

[0048] The rotation angle set by the first angle setting unit 91 is transmitted to the inner swing portion 90A of the upper secondary air flow path section 24A and the inner swing portion 90B of the lower secondary air flow path section 24B via the first transmission unit 92. Then, the inner swing portion 90A of the upper secondary air flow path section 24A and the inner swing portion 90B of the lower secondary air flow path section 24B each rotate to the rotation angle set by the first angle setting unit 91. Such a first adjustment device 86 is, for example, a turnbuckle (see FIG. 9A).

[0049] A description will now be given of an example of a specific configuration of the first adjustment device 86. Figure 9A is a diagram schematically showing the configuration of the first adjustment device 86 according to some embodiments.

[0050] 9A, the first angle setting unit 91 of the first adjustment device 86 includes a main body 120 that sets the rotation angle of the inner swing units 90A and 90B, and a pair of telescopic units 122A and 122B whose length protruding from the main body 120 in the vertical direction D2 is determined according to the rotation angle set by the main body 120. When one telescopic unit 122A extends upward, the other telescopic unit 122B extends downward. When one telescopic unit 122A contracts downward, the other telescopic unit 122B contracts upward. The pair of telescopic units 122A and 122B expand and contract by approximately the same amount.

[0051] The first transmission part 92 of the first adjustment device 86 includes a connection part 124A that connects the protruding end 123A of one of the extension parts 122A to the inner swing part 90A, and a connection part 124B that connects the protruding end 123B of the other extension part 122B to the inner swing part 90B.

[0052] A connection position PA of the connecting portion 124A to the inner swing portion 90A is below the fixed end 126A of the inner swing portion 90A. The connecting portion 124A extends from the connection position PA in the other direction in the axial direction D1. The connecting portion 124A is configured to push the inner swing portion 90A when one of the extendable portions 122A extends upward. When the inner swing portion 90A is pushed by the connecting portion 124A, it rotates (swings) upward. Furthermore, the connecting portion 124A is configured to pull the inner swing portion 90A when one of the extendable portions 122A retracts downward. When the inner swing portion 90A is pulled by the connecting portion 124A, it rotates (swings) downward.

[0053] A connection position PB of the connecting portion 124B to the inner swing portion 90B is above the fixed end 126B of the inner swing portion 90B. The connecting portion 124B extends from the connection position PB in the other direction in the axial direction D1. The connecting portion 124B is configured to push the inner swing portion 90B when the other expandable portion 122B expands downward. When the inner swing portion 90B is pushed by the connecting portion 124B, it rotates (swings) downward. Furthermore, the connecting portion 124B is configured to pull the inner swing portion 90B when the other expandable portion 122B contracts upward. When the inner swing portion 90B is pulled by the connecting portion 124B, it rotates (swings) upward. Thus, in the embodiment illustrated in FIG. 9A, the inner swing portion 90B is configured to rotate in the direction opposite to the rotation direction of the inner swing portion 90A. The rotation angle of the inner swing portion 90B is the same as the rotation angle of the inner swing portion 90A.

[0054] The second adjustment device 88 is configured to be able to simultaneously adjust the orientation of the outer outlet 44A of the upper secondary air flow path section 24A and the outer outlet 44B of the lower secondary air flow path section 24B. In the embodiment illustrated in Fig. 8, the second adjustment device 88 includes a second angle setting unit 93 and a second transmission unit 95. Note that in Fig. 8, the second transmission unit 95 is illustrated by a dotted line.

[0055] The second angle setting unit 93 is a device for setting the rotation angle (tilt angle) of the outer swing unit 94 and is, for example, a handle. The second transmission unit 95 connects the second angle setting unit 93 to the outer swing unit 94A of the upper secondary air flow path unit 24A, and also connects the second angle setting unit 93 to the outer swing unit 94B of the lower secondary air flow path unit 24B. The second transmission unit 95 is, for example, a rod-shaped member.

[0056] The rotation angle set by the second angle setting unit 93 is transmitted to the outer swing portion 94A of the upper secondary air flow path section 24A and the outer swing portion 94B of the lower secondary air flow path section 24B via the second transmission unit 95. Then, each of the outer swing portion 94A of the upper secondary air flow path section 24A and the outer swing portion 94B of the lower secondary air flow path section 24B rotates to the rotation angle set by the second angle setting unit 93. Such a second adjustment device 88 is, for example, a turnbuckle (see FIG. 9B).

[0057] FIG. 9B is a diagram illustrating a schematic configuration of a second adjustment device 88 according to some embodiments.

[0058] As illustrated in FIG. 9B, the second angle setting unit 93 of the second adjustment device 88 includes a main body 130 that sets the rotation angle of the outer swing units 94A and 94B, and a pair of telescopic units 132A and 132B whose length protruding from the main body 130 in the vertical direction D2 is determined according to the rotation angle set by the main body 130. When one telescopic unit 132A extends upward, the other telescopic unit 132B extends downward. When one telescopic unit 132A contracts downward, the other telescopic unit 132B contracts upward. The pair of telescopic units 132A and 132B expand and contract by approximately the same amount.

[0059] The second transmission part 95 of the second adjustment device 88 includes a connection part 134A connecting the protruding end 133A of one of the telescopic parts 132A to the outer swing part 94A, and a connection part 134B connecting the protruding end 133B of the other telescopic part 132B to the outer swing part 94B.

[0060] A connection position PC of the connecting portion 134A to the outer swing portion 94A is below the fixed end 136A of the outer swing portion 94A. The connecting portion 134A extends from the connection position PC in the other direction in the axial direction D1. The connecting portion 134A is configured to push the outer swing portion 94A when one of the extendable portions 132A extends upward. When pushed by the connecting portion 134A, the outer swing portion 94A rotates (swings) upward. Furthermore, the connecting portion 134A is configured to pull the outer swing portion 94A when one of the extendable portions 132A retracts downward. When pulled by the connecting portion 134A, the outer swing portion 94A rotates (swings) downward.

[0061] A connection position PD of the connecting portion 134B to the outer swing portion 94B is above the fixed end 136B of the outer swing portion 94B. The connecting portion 134B extends from the connection position PD in the other direction in the axial direction D1. The connecting portion 134B is configured to push the outer swing portion 94B when the other expandable portion 132B expands downward. When pushed by the connecting portion 134B, the outer swing portion 94B rotates (swings) downward. Furthermore, the connecting portion 134B is configured to pull the outer swing portion 94B when the other expandable portion 132B contracts upward. When pulled by the connecting portion 134B, the outer swing portion 94B rotates (swings) upward. Thus, in the embodiment illustrated in FIG. 9A, the outer swing portion 94B is configured to rotate in the direction opposite to the rotation direction of the outer swing portion 94A. The rotation angle of the outer swing portion 94B is the same as the rotation angle of the outer swing portion 94A.

[0062] The operation and effect of the gas burner 4 according to the third embodiment will be described. The flame stability can be increased or decreased by adjusting the outflow direction of the secondary air A2 (or low-oxygen secondary air A21) flowing out from the inner outlet 42. According to the third embodiment, the amount and outflow direction of the secondary air A2 (or low-oxygen secondary air A21) flowing out from the inner outlet 42 are adjusted, so that the flame stability can be increased or decreased more precisely according to the combustion state. Furthermore, with a simple configuration (for example, a configuration using turnbuckles), the timing at which the secondary air A2 (or low-oxygen secondary air A21) flowing out from the inner outlet 42A of the upper secondary air flow path section 24A and the inner outlet 42B of the lower secondary air flow path section 24B comes into contact with the gas fuel F (i.e., the formation of a flame) can be adjusted. According to the configuration illustrated in Figure 9A, the orientation of the inner outlet 42A and the orientation of the inner outlet 42B are adjusted to be symmetrical with each other across the axis O of the nozzle 20, so that the timing at which the secondary air A2 (or low-oxygen secondary air A21) comes into contact with the gas fuel F can be easily adjusted.

[0063] By adjusting the outflow direction of the secondary air A2 flowing out from the outer outlet 44, slow combustion can be promoted or suppressed. According to the third embodiment, the amount and outflow direction of the secondary air A2 flowing out from the outer outlet 44 are adjusted, so that slow combustion can be promoted or suppressed more precisely depending on the combustion state. Furthermore, with a simple configuration (for example, a configuration using a turnbuckle), the timing at which the secondary air A2 flowing out from the outer outlet 44A of the upper secondary air flow path section 24A and the outer outlet 44B of the lower secondary air flow path section 24B contacts the gas fuel F (i.e., flame formation) can be adjusted. According to the embodiment illustrated in FIG. 9B, the orientations of the outer outlet 44A and the outer outlet 44B are adjusted to be symmetrical with each other across the axis O of the nozzle 20, so that the timing at which the secondary air A2 contacts the gas fuel F can be easily adjusted.

[0064] In the third embodiment, the gas burner 4 is provided with both the first adjusting device 86 and the second adjusting device 88, but the present disclosure is not limited to this form. In some embodiments, the gas burner 4 is provided with either the first adjusting device 86 or the second adjusting device 88.

[0065] The adjustment of the amount of secondary air A2 flowing out from the inner outlet 42 and the amount of secondary air A2 flowing out from the outer outlet 44 by the flow rate adjustment device 25 may be performed automatically or manually by an operator. An automation system for the combustion equipment 1 that automates the adjustment of the amount of secondary air A2 flowing out by the flow rate adjustment device 25 will be described below.

[0066] Fig. 10 is a system diagram showing an automation system for a combustion facility 1 according to some embodiments. In the embodiment shown in Fig. 10, the combustion facility 1 includes a load acquisition device 140 that acquires the load BL of the combustion facility 1, and a control device 142 that controls the flow rate adjustment device 25 based on the load BL of the combustion facility 1 acquired by the load acquisition device 140. The load BL of the combustion facility 1 is, for example, the amount of power generation required of the combustion facility 1 (boiler) or the amount of steam generated by the combustion facility 1.

[0067] The control device 142 is, for example, a computer, and includes a processor such as a CPU or GPU (not shown), memories such as a ROM or RAM, and an I / O interface. The control device 142 realizes several functions provided by the processor by operating (calculating, etc.) according to instructions of a program loaded into the memory. In some embodiments, the control device 142 is a cloud server provided in a cloud environment.

[0068] 10 , the control device 142 is electrically connected to each of the load acquisition device 140 and the flow rate adjustment device 25. The control device 142 instructs the flow rate adjustment device 25 on the outflow rate of the secondary air A2 flowing out from the inner outlet 42 and the outflow rate of the secondary air A2 flowing out from the outer outlet 44 based on the load BL of the combustion equipment 1 acquired from the load acquisition device 140. The flow rate adjustment device 25 adjusts the flow rate of the secondary air A2 flowing out from the inner outlet 42 and the outer outlet 44 (adjusts the opening degrees of each of the first valve 46, the second valve 48, the third valve 50, and the fourth valve 52) in accordance with the instruction from the control device 142.

[0069] 10 , the control device 142 is electrically connected to each of the first adjustment device 86 and the second adjustment device 88. Based on the load BL of the combustion equipment 1 acquired from the load acquisition device 140, the control device 142 instructs the first adjustment device 86 about the orientation of the inner outlet 42 of the secondary air passage section 24, and instructs the second adjustment device 88 about the orientation of the outer outlet 44 of the secondary air passage section 24. The first adjustment device 86 adjusts the orientation of the inner outlet 42 of the secondary air passage section 24 in accordance with the instruction from the control device 142. The second adjustment device 88 adjusts the orientation of the outer outlet 44 of the secondary air passage section 24 in accordance with the instruction from the control device 142.

[0070] According to the embodiment illustrated in FIG. 10, it is possible to improve flame stability or promote slow combustion based on the load BL of the combustion equipment 1.

[0071] In some embodiments, when the load BL of the combustion equipment 1 becomes smaller than a preset threshold, the control device 142 controls the flow rate regulator 25 so that the amount of secondary air A2 flowing out from the inner outlet 42 is greater than the outer outlet 44. When the load BL of the combustion equipment 1 becomes smaller, the amount of gas fuel F supplied to the gas burner 4 decreases, and the amount of NOx generated decreases. Therefore, when the load BL of the combustion equipment 1 is smaller than the threshold, the flame stability can be improved by increasing the amount of secondary air A2 flowing out from the inner outlet 42 rather than the outer outlet 44.

[0072] In some embodiments, when the load BL of the combustion equipment 1 becomes larger than a preset threshold, the control device 142 controls the flow rate regulator 25 so that the amount of secondary air A2 flowing out from the outer outlet 44 is greater than the inner outlet 42. When the load BL of the combustion equipment 1 becomes larger, the amount of gas fuel F supplied to the gas burner 4 increases, and the amount of NOx generated increases. Therefore, when the load BL of the combustion equipment 1 is larger than the threshold, slow combustion can be promoted and the generation of NOx can be suppressed by increasing the amount of secondary air A2 flowing out from the outer outlet 44 rather than the inner outlet 42.

[0073] The contents described in each of the above embodiments can be understood, for example, as follows.

[0074] [1] The gas burner (4) according to the present disclosure is A gas burner for burning a gas fuel (F) containing hydrogen, a nozzle (20) for ejecting the gas fuel; a primary air flow path portion (22) that surrounds the nozzle in a front view seen along an axial direction (D1) of the nozzle and forms a primary air outlet (36) through which the primary air (A1) flows out; at least one secondary air flow path portion (24) that is located above or below the primary air outlet in the front view and that forms a secondary air outlet (40) through which secondary air (A2) flows out, the secondary air outlet including an inner outlet (42) and an outer outlet (44) that is located farther from the primary air outlet than the inner outlet; and a flow rate adjusting device (25) that can adjust each of the amount of secondary air flowing out from the inner outlet and the amount of secondary air flowing out from the outer outlet.

[0075] According to the configuration described in [1] above, since the outer outlet is located farther from the primary air outlet than the inner outlet, the secondary air flowing out from the inner outlet can be used for flame stabilization, and the secondary air flowing out from the outer outlet can be used for promoting slow combustion. Furthermore, since the gas burner according to the present disclosure is equipped with a flow rate adjustment device, it is possible to improve flame stabilization or promote slow combustion depending on the combustion state. Therefore, the combustion state can be easily controlled.

[0076] [2] In some embodiments, in the configuration described in [1] above, The inner outlet is configured to allow low-oxygen secondary air (A21) having a lower oxygen concentration than the secondary air flowing out from the outer outlet to flow out.

[0077] Hydrogen has a higher combustion speed than the components contained in conventional gas fuels. Therefore, hydrogen and oxygen are mixed quickly, which quickly raises the temperature of the combustion space where the gas fuel is burned, promoting the generation of nitrogen oxides (NOx). In contrast, according to the configuration described in [2] above, the low-oxygen secondary air flowing out from the inner outlet is brought into contact with the gas fuel before the secondary air flowing out from the outer outlet. This allows the hydrogen and oxygen to mix more slowly, suppressing the temperature rise in the combustion space. This further suppresses the generation of NOx.

[0078] [3] In some embodiments, in the configuration described in [1] or [2] above, the at least one secondary air flow path portion includes a pair of secondary air flow path portions (28A, 28B) arranged so as to sandwich the primary air flow path portion in the vertical direction, The air conditioner further includes a first adjusting device (86) capable of simultaneously adjusting the orientation of the inner outlets (42A, 42B) of the pair of secondary air flow path portions.

[0079] The flame stability can be increased or decreased by adjusting the flow direction of the secondary air flowing out from the inner outlet. According to the configuration described in [3] above, the amount and flow direction of the secondary air flowing out from the inner outlet are adjusted, so that the flame stability can be increased or decreased more precisely depending on the combustion state. In addition, with a simple configuration (for example, a configuration using a turnbuckle), the timing at which the secondary air flowing out from the inner outlet comes into contact with the gas fuel can be adjusted, thereby adjusting the formation of a flame.

[0080] [4] In some embodiments, in the configuration described in [3] above, The air conditioner further includes a second adjusting device capable of simultaneously adjusting the orientation of the outer outlets (44A, 44B) of the pair of secondary air flow path portions.

[0081] By adjusting the flow direction of the secondary air flowing out from the outer outlet, slow combustion can be promoted or suppressed. According to the configuration described in [4] above, the amount and flow direction of the secondary air flowing out from the outer outlet are adjusted, so that slow combustion can be promoted or suppressed more precisely depending on the combustion state. In addition, with a simple configuration (for example, a configuration using a turnbuckle), the timing at which the secondary air flowing out from the outer outlet comes into contact with the gas fuel can be adjusted, thereby adjusting the formation of a flame.

[0082] [5] In some embodiments, in the configuration described in any one of [1] to [4] above, When an imaginary line (80) is extended linearly in the vertical direction from the axis (O) of the nozzle in the front view, the distance between a first intersection point (82) where the imaginary line intersects with the periphery of the primary air outlet and the axis of the nozzle is defined as r, and the distance between a second intersection point (84) where the imaginary line first intersects with the periphery of the inner outlet and the axis of the nozzle is defined as d. The relationship 1.5×r≦d≦5×r is satisfied.

[0083] As described above, hydrogen has a higher combustion rate compared to the components contained in conventional gas fuels. Therefore, even if the inner outlet is separated from the axis of the nozzle so as to satisfy 1.5×r≦d, flame retention by the secondary air flowing out from the inner outlet can be achieved. Further, by satisfying 1.5×r≦d, the contact between the secondary air flowing out from the outer outlet and the gas fuel can be delayed, and slow combustion can be promoted. On the other hand, when 5×r<d is satisfied, it becomes difficult to achieve flame retention by the secondary air flowing out from the inner outlet, and at the same time, the delay in the timing of the supplied secondary air is large, and it becomes difficult to maintain an appropriate combustion state by controlling the flow rate of the secondary air. According to the configuration described in the above [5], the inner outlet is separated from the axis of the nozzle so as to satisfy 1.5×r≦d≦5×r, so that while realizing flame retention by the secondary air flowing out from the inner outlet, the contact between the secondary air flowing out from the outer outlet and the gas fuel can be delayed, and slow combustion can be promoted.

[0084] [6] In some embodiments, in the configuration described in any one of [1] to [5] above, The gas burner is a square burner in which the shape of the end face (5) facing the furnace (2) has a longitudinal direction along the vertical direction.

[0085] According to the configuration described in the above [6], the configuration described in any one of [1] to [5] above can be applied to a square burner.

[0086] [7] In some embodiments, the combustion equipment is a combustion equipment (1) including the gas burner described in any one of [1] to [6] above, a load acquisition device (140) that acquires the load (BL) of the combustion equipment; a control device (142) that controls the flow rate adjustment device based on the load of the combustion equipment acquired by the load acquisition device.

[0087] According to the configuration described in the above [7], based on the load of the combustion equipment, the flame retention property can be enhanced or slow combustion can be promoted.

Explanation of symbols

[0088] 1 Combustion equipment 2 Furnace 4 Gas burner 5 End face of gas burner 6 Combustion space 20 nozzles 22 Primary air flow path 24 Secondary air flow path 25 Flow control device 36 Primary air outlet 40 Secondary air outlet 40A Secondary air outlet of upper secondary air passage 40B Secondary air outlet of lower secondary air flow passage 42 Inner exit 42A Upper secondary air passage inner outlet 42B Inner outlet of lower secondary air passage 44 External exit 44A Outer outlet of upper secondary air passage 44B Outer outlet of lower secondary air passage 80 Virtual Line 82 First Intersection 84 2nd Intersection 86 1st adjustment device 88 Second regulator 140 Load acquisition device 142 Control device A1 Primary air A2 Secondary air A21 Low-oxygen secondary air BL Combustion equipment load D1 Axial direction D2 Vertical direction F Gas fuel O axis

Claims

1. 1. A gas burner for burning a gas fuel containing hydrogen, comprising: a cylindrical nozzle that ejects the gas fuel; a cylindrical primary air flow path portion that is disposed coaxially with the nozzle in a front view seen along the axial direction of the nozzle, surrounds the nozzle, and forms a primary air outlet through which the primary air flows out; a pair of secondary air flow path sections, the pair of secondary air outlets being located above and below the primary air outlet and spaced apart from each other in the front view, and through which secondary air flows out, each of the secondary air outlets including a rectangular inner outlet and a rectangular outer outlet located farther from the primary air outlet than the inner outlet; a flow rate adjusting device for adjusting the amount of secondary air flowing out of the inner outlet and the amount of secondary air flowing out of the outer outlet, for each of the pair of secondary air outlets; a first adjusting device that can simultaneously adjust the orientation of the inner outlets of each of the pair of secondary air flow path portions; a second adjusting device that can simultaneously adjust the orientation of the outer outlets of each of the pair of secondary air flow path portions; Equipped with When viewed from the front, a horizontal imaginary line is extended linearly from the axis of the nozzle along the horizontal direction so as not to intersect with the air outlet. Gas burner.

2. The inner outlet is configured to allow low-oxygen secondary air having a lower oxygen concentration than the secondary air flowing out of the outer outlet to flow out.

2. The gas burner according to claim 1.

3. The one adjustment device is a pair of inner swing sections each including a respective one of said pair of inner outlets; a first main body portion that sets the rotation angles of the pair of inner swing portions; a pair of inner stretchable parts whose protruding length from the first main body part is determined according to the rotation angle set in the first main body part, the pair of inner stretchable parts being configured so that when one inner stretchable part extends to one side, the other inner stretchable part extends to the other side, and when one inner stretchable part contracts to the other side, the other inner stretchable part contracts to the one side; a pair of inner connection portions that connect the respective protruding ends of the pair of inner telescopic portions to the pair of inner swing members; Including, 3. A gas burner according to claim 1 or 2.

4. The two adjusting devices are a pair of outer swing sections each including a respective one of said pair of outer outlets; a second main body portion that sets the rotation angles of the pair of outer swing portions; a pair of outer stretchable parts whose protruding length from the second main body part is determined according to the rotation angle set in the second main body part, the pair of outer stretchable parts being configured so that when one outer stretchable part extends to one side, the other outer stretchable part extends to the other side, and when one outer stretchable part contracts to the other side, the other outer stretchable part contracts to the one side; a pair of outer connection portions connecting the respective protruding ends of the pair of outer expansion and contraction portions to the pair of outer swing members; Including, 4. A gas burner according to claim 3.

5. When an imaginary line is extended linearly in the vertical direction from the axis of the nozzle in the front view, the distance between a first intersection point where the imaginary line intersects with the periphery of the primary air outlet and the axis of the nozzle is defined as r, and the distance between a second intersection point where the imaginary line first intersects with the periphery of the inner outlet and the axis of the nozzle is defined as d, 1.5×r≦d≦5×r is satisfied; A gas burner according to any one of claims 1 to 4.

6. The gas burner is a rectangular burner whose end face facing the furnace has a longitudinal direction along the vertical direction. A gas burner according to any one of claims 1 to 5.

7. A combustion facility comprising the gas burner according to any one of claims 1 to 6, a load acquisition device that acquires a load of the combustion facility; a control device that controls the flow rate adjusting device based on the load of the combustion equipment acquired by the load acquisition device, Combustion equipment.

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