Combustion facility

Abstract

To reduce power required for supplying air for combustion.SOLUTION: A combustion facility includes a furnace, a first burner provided on a furnace wall of the furnace, and a second burner provided on the furnace wall of the furnace adjacently to the first burner. The first burner includes an air-fuel mixture jetting part for jetting an air-fuel mixture obtained by mixing carbon fuel with primary air inside the furnace, and a first secondary air flow passage part surrounding at least part of the periphery of the air-fuel mixture jetting part, from which secondary air for carbon fuel flows out. The second burner includes a gas fuel jetting part for jetting gas fuel containing hydrogen inside the furnace, a primary air flow passage part surrounding the periphery of the gas fuel jetting part, from which primary air for gas fuel flows out, and at least one second secondary air flow passage part for causing secondary air for gas fuel to flow out from the outside in the radial direction of the gas fuel jetting part rather than a primary air exit. The second burner includes a recirculation region in which a virtual line extending in the radial direction from the center of the gas fuel jetting part does not intersect with a secondary air exit.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to combustion equipment. [Background technology]

[0002] Combustion equipment such as boilers is provided with pulverized coal burners that burn pulverized coal, and technology has been introduced to suppress the generation of nitrogen oxides (NOx) due to the combustion of pulverized coal. For example, in Patent Document 1, the combustion equipment is provided with multiple coal burners, and a multi-stage combustion method is applied in which each of the multiple coal burners supplies combustion air in multiple stages. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-017030 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, as the number of coal burners installed in a combustion facility increases, the amount of power required to supply combustion air becomes extremely large.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide combustion equipment that can reduce the power required to supply combustion air. [Means for solving the problem]

[0006] In order to achieve the above object, the combustion equipment according to the present disclosure includes a furnace, a first burner provided on a furnace wall of the furnace, and a second burner provided on the furnace wall of the furnace adjacent to the first burner, the first burner including a mixture ejection portion that ejects a mixture of a carbonaceous fuel and primary air for the carbonaceous fuel into the furnace, and a first secondary air flow path portion that surrounds at least a portion of the periphery of the mixture ejection portion in a front view seen along an axial direction of the mixture ejection portion and forms an outlet through which secondary air for the carbonaceous fuel flows out, and the second burner includes a gas fuel ejection portion that ejects a gas fuel containing hydrogen into the furnace. the second burner includes a gas fuel jetting portion, a primary air flow path portion which, in a front view seen along the axial direction of the gas fuel jetting portion, surrounds the gas fuel jetting portion and forms a primary air outlet through which the primary air for the gas fuel flows out, and at least one second secondary air flow path portion which, in a front view seen along the axial direction of the gas fuel jetting portion, forms a secondary air outlet through which the secondary air for the gas fuel flows out from a position radially outside the gas fuel jetting portion relative to the primary air outlet, and the second burner includes a recirculation region in which a virtual line extending radially from the center of the gas fuel jetting portion does not intersect with the secondary air outlet. Effect of the Invention

[0007] According to the combustion equipment of the present disclosure, the power required to supply combustion air can be reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a combustion facility according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a schematic configuration of a first burner according to one embodiment. [Diagram 3] FIG. 2 is a diagram illustrating a schematic configuration of a second burner according to one embodiment. [Figure 4] FIG. 2 is a schematic diagram (front view) of the configuration of a second burner according to one embodiment, as viewed from inside a furnace. [Diagram 5] FIG. 13 is a diagram illustrating a recirculation region according to an embodiment. [Figure 6] FIG. 2 is a diagram for explaining the layout of a first burner and a second burner in the combustion equipment according to one embodiment. [Figure 7] FIG. 11 is a schematic diagram (front view) of the configuration of a first burner according to another embodiment, as viewed from inside the furnace. [Figure 8] FIG. 2 is a schematic diagram of a second burner configuration according to some embodiments. [Figure 9] FIG. 2 is a schematic functional block diagram of a control device according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a combustion facility 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, and does not limit the present disclosure. The embodiment can be arbitrarily modified within the scope of the technical idea of ​​the present disclosure.

[0010] <Combustion equipment> (composition) Fig. 1 is a diagram showing a schematic configuration of a combustion equipment 1 according to one embodiment. As shown in Fig. 1, the combustion equipment 1 includes a furnace 2, a first burner 4, and a second burner 6.

[0011] The furnace 2 has a cylindrical shape, and a combustion space 20 defined by a furnace wall 21 is formed inside. A first burner 4 and a second burner 6 are provided on the furnace wall 21 of the furnace 2. Such a combustion equipment 1 is, for example, a boiler, which forms a flame in the combustion space 20 to combust a carbon fuel F1 and a gas fuel F2 containing hydrogen, respectively, to generate high-temperature exhaust gas G, and 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 inside the furnace 2, or may be recovered by a heat exchanger provided outside the furnace 2.

[0012] Fig. 2 is a diagram showing a schematic configuration of a first burner 4 according to one embodiment. As shown in Fig. 2, the first burner 4 includes a heavy oil nozzle 3, a mixture ejection section 8, a first secondary air passage section 14, and a tertiary air passage forming section 16.

[0013] The heavy oil nozzle 3 sprays heavy oil Fo into the combustion space 20 through a throat 23 formed in the furnace wall 21, for example, to start the first burner 4 or to increase the heat generation amount of the first burner 4. The heavy oil nozzle 3 has a cylindrical shape, and a heavy oil flow path 5 through which the heavy oil Fo flows is formed inside. Note that the first burner 4 may include a liquid fuel nozzle that sprays liquid fuel such as light oil or crude oil toward the combustion space 20, instead of the heavy oil nozzle 3.

[0014] The mixture ejection section 8 ejects the mixture FA, which is a mixture of carbonaceous fuel F1 and primary air A1 for the carbonaceous fuel F1, into the combustion space 20 (inside the furnace 2) through the throat 23. The mixture ejection section 8 is configured to allow the mixture FA to flow, and is, for example, a sleeve having a cylindrical shape centered on an axis O1. In one embodiment, the carbonaceous fuel F1 is pulverized coal. In another embodiment, the mixture ejection section 8 is a nozzle having a hole formed therein for ejecting the mixture FA into the combustion space 20.

[0015] Hereinafter, the direction in which the axis O1 of the mixture jetting portion 8 extends is referred to as the axial direction of the mixture jetting portion 8 (hereinafter, referred to as the "first axial direction D1"). Of the first axial direction D1, the direction toward the combustion space 20, which is the jetting side of the mixture FA, is referred to as one side of the first axial direction D1, and the direction away from the combustion space 20 is referred to as the other side of the first axial direction D1. In addition, the direction perpendicular to the axis O1 of the mixture jetting portion 8 starting from the axis O1 of the mixture jetting portion 8 is referred to as the radial direction of the mixture jetting portion 8 (hereinafter, referred to as the "first radial direction D2"). Of the first radial direction D2, the direction approaching the axis O1 is referred to as the inner side of the first radial direction D2, and the direction away from the axis O1 is referred to as the outer side of the first radial direction D2.

[0016] In the embodiment illustrated in FIG. 2, the mixture gas ejection section 8 covers the heavy oil nozzle 3 from the outside in the first radial direction D2. In other words, the heavy oil nozzle 3 is disposed in the mixture gas ejection section 8. Furthermore, the heavy oil nozzle 3 extends so as to be coaxial with the axis O1 of the mixture gas ejection section 8. The mixture gas ejection section 8 forms a mixture gas flow path 9 through which the mixture gas FA flows between the mixture gas ejection section 8 and the heavy oil nozzle 3. That is, the mixture gas flow path 9 is defined by the outer wall surface 3a of the heavy oil nozzle 3 and the inner wall surface 8a of the mixture gas ejection section 8. The tip of the mixture gas ejection section 8 on one side in the first axial direction D1 is open, and the mixture gas FA ejected from this opening flows into the combustion space 20 through the throat 23. As illustrated in FIG. 2, a flame stabilizer 10 may be attached to the tip of the mixture gas ejection section 8. A pulverized coal concentrating device 12 may be provided on the outer wall surface 8b of the mixture gas ejection section 8.

[0017] The first secondary air flow passage section 14 has a cylindrical shape and extends along the axis O1 of the mixture jet section 8 so as to surround the outside of the mixture jet section 8 in the first radial direction D2. More specifically, the first secondary air flow passage section 14 extends so as to be coaxial with the axis O1 of the mixture jet section 8. The first secondary air flow passage section 14 forms a secondary air flow passage 15 through which the secondary air A2 for the carbonaceous fuel F1 flows between the first secondary air flow passage section 14 and the mixture jet section 8. That is, the secondary air flow passage 15 is defined by the outer wall surface 8b of the mixture jet section 8 and the inner wall surface 14a of the first secondary air flow passage section 14. An outlet 17 through which the secondary air A2 for the carbonaceous fuel F1 flows out is formed at the tip of one side of the first axial direction D1 of the first secondary air flow passage section 14, and the secondary air A2 for the carbonaceous fuel F1 flowing out from the outlet 17 is mixed with the mixture FA. In the embodiment illustrated in FIG. 2, the tip 19 of the first secondary air flow passage section 14 on one side in the first axial direction D1 is located within the throat 23. The tip 19 of the first secondary air flow passage section 14 is spaced apart (increased in diameter) from the axis O1 of the mixture ejection section 8 as it moves toward one side in the first axial direction D1. The first secondary air flow passage section 14 surrounds the entire periphery of the mixture ejection section 8 in a front view seen along the first axial direction D1 (see FIG. 6). In one embodiment, the outlet 17 is circular in a front view seen along the first axial direction D1. In one embodiment, the first secondary air flow passage section 14 is a sleeve having a cylindrical shape.

[0018] 2, the tertiary air passage forming portion 16 forms a tertiary air passage 18 for the tertiary air A3 for the carbon fuel F1 to flow outside the first radial direction D2 from the first secondary air passage portion 14. The outlet of the tertiary air passage 18 is connected to a space formed between the throat 23 and the tip portion 19 of the first secondary air passage portion 14. The throat 23 and the tip portion 19 of the first secondary air passage portion 14 are configured so that the tertiary air A3 for the carbon fuel F1 flows out into the combustion space 20 at a tilt toward the opposite side to the axis O1 side of the mixture ejection portion 8 compared to the secondary air A2 for the carbon fuel F1.

[0019] The second burner 6 will be described. Fig. 3 is a diagram showing a schematic configuration of the second burner 6 according to one embodiment. Fig. 4 is a schematic diagram (front view) of the configuration of the second burner 6 according to one embodiment when viewed from inside the furnace 2. As shown in Fig. 3, the second burner 6 includes a gas fuel ejection section 30, a primary air passage section 32, and a second secondary air passage section 34.

[0020] The gas fuel ejection part 30 ejects the gas fuel F2 containing hydrogen into the combustion space 20 (inside the furnace 2). The gas fuel ejection part 30 is configured to allow the gas fuel F2 to flow therethrough, and has, for example, a cylindrical shape centered on the axis O2. The gas fuel ejection part 30 is a nozzle in which an ejection port 29 for ejecting the gas fuel F2 is formed.

[0021] Hereinafter, the direction in which the axis O2 of the gas fuel ejection part 30 extends is defined as the axial direction of the gas fuel ejection part 30 (hereinafter, referred to as the "second axial direction D3"). Of the second axial direction D3, the direction toward the combustion space 20, which is the ejection side of the gas fuel F2, is defined as one side of the second axial direction D3, and the direction away from the combustion space 20 is defined as the other side of the second axial direction D3. In addition, the direction perpendicular to the axis O2 of the gas fuel ejection part 30 starting from the axis O2 of the gas fuel ejection part 30 is defined as the radial direction of the gas fuel ejection part 30 (hereinafter, referred to as the "second radial direction D4"). Of the second radial direction D4, the direction approaching the axis O2 is defined as the inner side of the second radial direction D4, and the direction away from the axis O2 is defined as the outer side of the second radial direction D4.

[0022] In this disclosure, "hydrogen-containing gas fuel F2" includes those containing hydrogen and fuels other than hydrogen (mixed combustion) and those containing only hydrogen (monocarbon combustion), and further, those containing hydrogen and fuels other than hydrogen can be classified into fuels in which hydrogen is the main component (volume ratio of hydrogen is 50% or more) and fuels in which a fuel other than hydrogen is the main component (volume ratio of hydrogen is less than 50%). "Hydrogen-containing gas fuel F2" includes all of these cases.

[0023] The primary air flow passage section 32 has a cylindrical shape and extends along the axis O2 of the gas fuel ejection section 30 so as to surround the outside of the gas fuel ejection section 30 in the second radial direction D4. This primary air flow passage section 32 forms a primary air flow passage 33 through which the primary air A4 for the gas fuel F2 flows between the gas fuel ejection section 30 and the primary air flow passage section 32. In other words, the primary air flow passage 33 is defined by the outer wall surface 30a of the gas fuel ejection section 30 and the inner wall surface 32a of the primary air flow passage section 32. At the tip of one side of the primary air flow passage section 32 in the second axial direction D3, a primary air outlet 35 through which the primary air A4 for the gas fuel F2 flows out is formed, and the primary air A4 for the gas fuel F2 flowing out from the primary air outlet 35 is mixed with the gas fuel F2. Such a primary air flow passage section 32 surrounds the periphery of the gas fuel ejection section 30 in a front view seen along the second axial direction D3 (see FIG. 4). In one embodiment, the primary air outlet 35 has a circular shape in a front view seen along the second axial direction D3. In one embodiment, the primary air passage portion 32 is a sleeve having a cylindrical shape.

[0024] 3, the second burner 6 may include a flame stabilizer 36 provided at the outlet portion of the primary air passage 33 mainly for the purpose of flame stabilization. The primary air A4 for the gas fuel F2 flowing through the primary air passage 33 is a straight flow, but the flame stabilizer 36 is configured to impart a swirling force to a part or all of the primary air A4 for the gas fuel F2.

[0025] The second secondary air flow passage section 34 defines a secondary air flow passage 37 through which the secondary air A5 for the gas fuel F2 flows. In a front view seen along the second axial direction D3, the second secondary air flow passage section 34 defines a secondary air outlet 39 through which the secondary air A5 for the gas fuel F2 flows out from outside the primary air outlet 35 in the second radial direction D4 (see FIG. 4).

[0026] In one embodiment, as shown in FIG. 3, the second secondary air flow passage section 34 includes an upper second secondary air flow passage section 34A (34) and a lower second secondary air flow passage section 34B (34) located below the upper second secondary air flow passage section 34A. The upper second secondary air flow passage section 34A is a first cylindrical section 40 having an open end on one side in the second axial direction D3. The opening of the first cylindrical section 40 is configured as a secondary air outlet 39A (39). The lower second secondary air flow passage section 34B is a second cylindrical section 42 having an open end on one side in the second axial direction D3. The opening of the second cylindrical section 42 is configured as a secondary air outlet 39B (39). The first cylindrical section 40 and the second cylindrical section 42 are separate from each other. The opening (secondary air outlet 39A) of the first cylindrical portion 40 is located on the opposite side to the opening (secondary air outlet 39B) of the second cylindrical portion 42 across the primary air outlet 35 in the vertical direction D5. In another embodiment, the second burner 6 includes one second secondary air flow path portion 34, or three or more second secondary air flow path portions 34.

[0027] In one embodiment, as illustrated in Fig. 4, each of the secondary air outlet 39A of the first cylindrical portion 40 and the secondary air outlet 39B of the second cylindrical portion 42 has a rectangular shape having a longitudinal direction along the left-right direction D6 in a front view (viewed along the second axial direction D3) as viewed from inside the furnace 2. The secondary air outlet 39A of the first cylindrical portion 40 and the secondary air outlet 39B of the second cylindrical portion 42 are arranged at intervals from each other in a circumferential direction centered on the axis O2 of the gas fuel ejection portion 30 in a front view as viewed from inside the furnace 2. The secondary air outlet 39A of the first cylindrical portion 40 and the secondary air outlet 39B of the second cylindrical portion 42 at least partially overlap each other in the left-right direction D6 as viewed from inside the furnace 2.

[0028] As illustrated in Fig. 4, the second burner 6 includes a recirculation region R in which an imaginary line X extending from the axis O2 of the gas fuel ejection part 30 in the second radial direction D4 does not intersect with either the secondary air outlet 39A of the first cylindrical part 40 or the secondary air outlet 39B of the second cylindrical part 42 in a front view seen from inside the furnace 2. Here, the recirculation region R will be specifically described. Fig. 5 is a diagram for explaining the recirculation region R according to one embodiment.

[0029] The imaginary line X is a half line extending in an arbitrary second radial direction D4 from the axis O2 of the gas fuel ejection part 30. As illustrated in Fig. 5, the angular position θ of the imaginary line X when it extends upward from the axis O2 of the gas fuel ejection part 30 is set to 0 degrees. This angular position θ increases as the gas fuel ejection part 30 rotates in a clockwise direction (rightward on the paper surface of Fig. 5) around the axis O2 of the gas fuel ejection part 30 as the rotation center, and the angular position θ when the imaginary line X rotates once is set to 360 degrees.

[0030] In one embodiment, the recirculation region R is configured such that the sum of the angular positions θ is 180 degrees or more. As illustrated in FIG. 5, when the angular position θ is 0 degrees, the imaginary line X intersects with the secondary air outlet 39A of the first cylindrical portion 40. The imaginary line X intersects with the secondary air outlet 39A of the first cylindrical portion 40 until the angular position θ increases from 0 degrees to 30 degrees or less. The imaginary line X does not intersect with either the secondary air outlet 39A of the first cylindrical portion 40 or the secondary air outlet 39B of the second cylindrical portion 42 when the angular position θ is in the range of more than 30 degrees and less than 150 degrees. The imaginary line X intersects with the secondary air outlet 39B of the second cylindrical portion 42 until the angular position θ increases from 150 degrees to 210 degrees or less. When the angular position θ is in the range of greater than 210 degrees and less than 330 degrees, the imaginary line X does not intersect with either the secondary air outlet 39A of the first cylindrical portion 40 or the secondary air outlet 39B of the second cylindrical portion 42. The imaginary line X intersects with the secondary air outlet 39A of the first cylindrical portion 40 until the angular position θ increases to greater than or equal to 330 degrees and less than or equal to 360 degrees. That is, in the first embodiment, the sum of the angular positions θ is 240 degrees.

[0031] In one embodiment, the recirculation region R includes a first recirculation region R1(R) formed within a range where the angular position θ is greater than 30 degrees and less than 150 degrees. The first recirculation region R1 is located on the right side of the axis O2 of the gas fuel ejection part 30 in the left-right direction D6. The first recirculation region R1 is a region defined by a virtual line X whose angular position θ is 30 degrees and a virtual line X whose angular position θ is 150 degrees, and is a portion of the region where the angle formed by these two virtual lines X is smaller (120 degrees) than the primary air outlet 35.

[0032] More specifically, the first recirculation region R1 is defined as a position P1 where the imaginary line X with an angular position θ of 30 degrees intersects the secondary air outlet 39A of the first cylindrical portion 40. A position P2 where the imaginary line X with an angular position θ of 150 degrees intersects the secondary air outlet 39B of the second cylindrical portion 42. The first recirculation region R1 is a portion of the region defined by a straight line connecting the axis O2 of the gas fuel ejection portion 30 to the position P1, a straight line connecting the axis O2 of the gas fuel ejection portion 30 to the position P2, and an arc-shaped curve connecting the position P1 and the position P2 and protruding to the right, excluding the primary air outlet 35. The line connecting the position P1 and the position P2 may be a straight line.

[0033] In one embodiment, the recirculation region R includes a second recirculation region R2(R) formed in a range where the angular position θ is greater than 210 degrees and less than 330 degrees. The second recirculation region R2 is located on the left side of the axis O2 of the gas fuel ejection section 30 in the left-right direction D6. In other words, the second recirculation region R2 is located on the opposite side of the axis O2 of the gas fuel ejection section 30 from the first recirculation region R1 in the left-right direction D6. The second recirculation region R2 is a region defined by a virtual line X with an angular position θ of 210 degrees and a virtual line X with an angular position θ of 330 degrees, and is a portion of the region formed by these two virtual lines X at a smaller angle (120 degrees) excluding the primary air outlet 35.

[0034] More specifically, the second recirculation region R2 is defined as a position P3 where the imaginary line X with an angular position θ of 210 degrees intersects the secondary air outlet 39B of the second cylindrical portion 42. A position P4 where the imaginary line X with an angular position θ of 330 degrees intersects the secondary air outlet 39A of the first cylindrical portion 40. The second recirculation region R2 is a region defined by a straight line connecting the axis O2 of the gas fuel ejection portion 30 to the position P3, a straight line connecting the axis O2 of the gas fuel ejection portion 30 to the position P4, and an arc-shaped curve connecting the position P3 to the position P4 and protruding to the left, excluding the primary air outlet 35. The line connecting the position P3 to the position P4 may be a straight line.

[0035] Fig. 6 is a diagram for explaining the layout of the first burner 4 and the second burner 6 in the combustion equipment 1 according to one embodiment, as viewed from inside the furnace 2 (combustion space 20). In order to facilitate explanation, Fig. 6 illustrates the heavy oil nozzle 3, the mixture jetting section 8, and the first secondary air passage section 14 of the configuration of the first burner 4. Similarly, Fig. 6 illustrates the gas fuel jetting section 30, the primary air passage section 32, the upper second secondary air passage section 34A, and the lower second secondary air passage section 34B of the configuration of the second burner 6.

[0036] 6, the second burner 6 is provided on the furnace wall 21 of the furnace 2 adjacent to and above the first burner 4. In one embodiment, the air-fuel mixture ejection portion 8 and the gas fuel ejection portion 30 at least partially overlap each other in the left-right direction D6.

[0037] In the embodiment illustrated in Figure 6, if the distance from the axis O1 of the mixture ejection portion 8 to the axis O2 of the gas fuel ejection portion 30 is L, the length from the axis O1 of the mixture ejection portion 8 to the upper end of the first secondary air flow path portion 14 (the radius of the outlet 17) is l1, and the length from the axis O2 of the gas fuel ejection portion 30 to the lower end of the primary air flow path portion 32 (the radius of the primary air outlet 35) is l2, then 2(l1 + l2) ≦ L ≦ 7 (l1 + l2) is satisfied.

[0038] (Action and effect) The operation and effect of the combustion equipment 1 according to one embodiment will be described. Hydrogen has a faster combustion speed and better combustibility than carbon fuel F1. For this reason, a burner (hydrogen burner) that burns gas fuel F2 containing hydrogen has a smaller theoretical air volume of combustion air than a burner (coal burner) that burns a mixture FA containing carbon fuel F1.

[0039] According to one embodiment, the combustion equipment 1 includes a first burner 4 that burns the air-fuel mixture FA and a second burner 6 that burns the gas fuel F2. Therefore, compared to a case where the combustion equipment 1 includes only a plurality of first burners 4 (single-burning coal), the power required for the combustion equipment 1 to supply combustion air (for example, power for driving a fan) can be reduced. Note that in a combustion equipment already provided with a plurality of first burners 4 (coal burners), the power of the combustion equipment 1 may be reduced by replacing at least one of the plurality of first burners 4 with a second burner 6 (hydrogen burner).

[0040] When the hydrogen-containing gas fuel F2 is mixed with primary air A4 for the gas fuel F2 and burned, and then secondary air A5 for the gas fuel F2 is further mixed to burn the unburned gas fuel F2, the generation of nitrogen oxides (NOx) is greatly suppressed by flowing exhaust gas G into a region Ra (see FIG. 4) where the gas fuel F2 and the primary air A4 for the gas fuel F2 are mixed and burned. According to one embodiment, the second burner 6 can flow exhaust gas G into this region Ra via the recirculation region R. This makes it possible to suppress the generation of NOx.

[0041] Furthermore, according to one embodiment, the second burner 6 is provided adjacent to the upper side of the first burner 4, so that when the primary air A4 for the gas fuel F2 or the secondary air A5 for the gas fuel F2 is greater than the amount required for combustion of the gas fuel F2, this surplus combustion air can be used for combustion of the mixture FA. Note that, in one embodiment, the second burner 6 is provided adjacent to the upper side of the first burner 4, but the present disclosure is not limited to this form. The second burner 6 may be provided adjacent to the left, right, or lower side of the first burner 4.

[0042] According to one embodiment, the recirculation region R is easily formed by providing the first cylindrical portion 40 and the second cylindrical portion 42. The second burner 6 is disposed above the first burner 4, so that the time during which the carbonaceous fuel F1 is burned in the combustion space 20 (the residence time of the combustion of the carbonaceous fuel F1) can be extended, and the unburned portion of the carbonaceous fuel F1 can be reduced. Furthermore, the unburned portion of the carbonaceous fuel F1 can be gasified (C+H2O→CO+H2) by the steam generated by the combustion of hydrogen, and the unburned portion of the carbonaceous fuel F1 can be reduced.

[0043] In one embodiment, as shown in FIG. 6, the first burner 4 has a circular outlet 17 and is a burner for so-called wall combustion, but the present disclosure is not limited to this embodiment. FIG. 7 is a schematic diagram (front view) of the configuration of the first burner 4 according to another embodiment when viewed from inside the furnace 2. In the embodiment illustrated in FIG. 7, the first burner 4 is a burner for swirling combustion, and the outlet 17 is rectangular and elongated in the vertical direction D5. This outlet 17 surrounds the rectangular mixture ejection part 8 from above and below, but does not surround it from the left and right. Furthermore, the first burner 4 has an outlet of a rectangular tertiary air flow passage 18 formed at a position separated from the outlet 17 in the vertical direction D5.

[0044] <Other examples of combustion equipment configurations> FIG. 8 is a diagram that shows a schematic configuration of the second burner 6 according to some embodiments. As shown in FIG. 8, in some embodiments, the gas fuel ejection part 30 of the second burner 6 has a swing part 50 including an ejection port 29. The swing part 50 has a cylindrical shape, and the diameter of the swing part 50 decreases toward the combustion space 20. The swing part 50 has a fixed end on the opposite side to the combustion space 20 side in the second axial direction D3 and a rotating end on the combustion space 20 side, and is configured to be rotatable (swingable) along the second radial direction D4. In other words, the gas fuel ejection part 30 is configured so that the ejection direction of the gas fuel F2 ejected from the ejection port 29 can be freely tilted along the vertical direction D5.

[0045] In some embodiments, the combustion equipment 1 further includes a nozzle adjustment device 52 that changes the position of the nozzle 29 of the gas fuel ejection unit 30 along the vertical direction D5, and a control device 70. In the embodiment illustrated in Fig. 8, the nozzle adjustment device 52 includes a swing angle setting unit 54 and a transmission unit 56. In Fig. 8, the transmission unit 56 is illustrated by a dotted line.

[0046] The swing angle setting unit 54 is a device for setting the rotation angle (tilt angle) of the swing unit 50, and is, for example, a handle. The transmission unit 56 connects the swing angle setting unit 54 and the swing unit 50. Such a transmission unit 56 is, for example, a rod-shaped member. The swing angle setting unit 54 may be configured to be operable by an operator.

[0047] The rotation angle set by the swing angle setting unit 54 is transmitted to the swing unit 50 via the transmission unit 56. Then, the swing unit 50 rotates to the rotation angle set by the swing angle setting unit 54. Such an ejection nozzle adjustment device 52 is, for example, a turnbuckle.

[0048] The control device 70 is a computer such as an electronic control device, 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 70 realizes each of the functional units of the control device 70 by the processor operating (calculating, etc.) according to instructions of a program loaded into the memory. Each of the functional units of the control device 70 according to one embodiment will be described with reference to FIG. 9. In some embodiments, the control device 70 is a cloud server provided in a cloud environment.

[0049] Fig. 9 is a schematic functional block diagram of a control device 70 according to some embodiments. As shown in Fig. 9, the control device 70 includes an acquisition unit 72 and an instruction unit 74. The control device 70 is electrically connected to each of the nozzle adjustment device 52 and a measurement sensor 80 that measures the concentration B1 of nitrogen oxides contained in the exhaust gas G. Furthermore, the control device 70 is configured to be able to acquire the input amount B2 of carbon fuel F1, the input amount B3 of gas fuel F2, and the amount of heat recovered from the exhaust gas G, such as the amount of power generated by the boiler, B4.

[0050] The acquisition unit 72 acquires a concentration B1 of nitrogen oxides contained in the exhaust gas G and an amount B5 of unburned carbon fuel F1. The acquisition unit 72 acquires the concentration B1 of nitrogen oxides contained in the exhaust gas G from the measurement sensor 80. Furthermore, the acquisition unit 72 calculates the amount B5 of unburned carbon fuel F1 based on an input amount B2 of carbon fuel F1, an input amount B3 of gas fuel F2, and an amount B4 of heat recovered from the exhaust gas G.

[0051] The instruction unit 74 calculates the position of the nozzle 29 of the gas fuel ejection unit 30 based on the concentration B1 of nitrogen oxides contained in the exhaust gas G and the amount B5 of unburned carbon fuel F1 acquired by the acquisition unit 72. Then, the instruction unit 74 transmits an adjustment signal B6 to the nozzle adjustment device 52 to change the calculated position of the nozzle 29. When the nozzle adjustment device 52 receives the adjustment signal B6, it causes the swing angle setting unit 54 to set the rotation angle of the swing unit 50 so that the position of the nozzle 29 included in the adjustment signal B6 is the position of the nozzle 29. In another embodiment, the acquisition unit 72 acquires the concentration B1 of nitrogen oxides contained in the exhaust gas G or the amount B5 of unburned carbon fuel F1, and the instruction unit 74 calculates the position of the nozzle 29 of the gas fuel ejection unit 30 based on the information acquired by the acquisition unit 72 (the concentration B1 of nitrogen oxides contained in the exhaust gas G or the amount B5 of unburned carbon fuel F1).

[0052] According to some embodiments illustrated in Fig. 8 and Fig. 9, by lowering the position of the outlet 29 of the gas fuel ejection part 30, the gas fuel F2 ejected into the combustion space 20 approaches the mixture FA ejected into the combustion space 20. This can promote gasification of the unburned carbon fuel F1 by the water vapor. On the other hand, if the gas fuel F2 is brought closer to the mixture FA in the combustion space 20, the combustion temperature in the combustion space 20 may increase, and the amount of NOx generated may increase. For this reason, by raising the position of the outlet 29 of the gas fuel ejection part 30, the gas fuel F2 is separated from the mixture FA in the combustion space 20, and the generation of NOx can be suppressed.

[0053] According to some embodiments, since the gas fuel ejection part 30 has the swing part 50, by swinging the swing part 50, it becomes easy to bring the gas fuel F2 close to the mixture FA in the combustion space 20 and to move the gas fuel F2 away from the mixture FA. Therefore, it is possible to reduce the unburned carbon fuel F1 and suppress the generation of NOx according to the operating state of the combustion equipment 1. In another embodiment, the ejection port 29 of the gas fuel ejection part 30 is configured to be movable along the vertical direction D5.

[0054] According to some embodiments, the combustion facility 1 includes the control device 70, so that the amount B5 of the unburned carbon fuel F1 and the amount of NOx generated can be automatically and suitably adjusted.

[0055] The contents described in each of the above embodiments can be understood, for example, as follows.

[0056] [1] The combustion equipment (1) according to the present disclosure is Furnace (2), a first burner (4) provided on a furnace wall (21) of the furnace; A second burner (6) is provided on the furnace wall of the furnace adjacent to the first burner, The first burner is a mixture ejection section (8) for ejecting a mixture (FA) obtained by mixing carbonaceous fuel (F1) and primary air (A1) for the carbonaceous fuel into the furnace; a first secondary air flow passage portion (14) surrounding at least a part of the periphery of the mixture ejection portion in a front view seen along an axial direction (D1) of the mixture ejection portion and forming an outlet (17) through which the secondary air (A2) for the carbon fuel flows out; The second burner is a gas fuel ejection section (30) that ejects a gas fuel (F2) containing hydrogen into the furnace; a primary air flow passage portion (32) surrounding the gas fuel ejection portion in a front view seen along an axial direction (D3) of the gas fuel ejection portion and forming a primary air outlet (35) through which primary air (A4) for the gas fuel flows out; and at least one second secondary air flow path portion (34) in which a secondary air outlet (39) is formed, through which secondary air (A5) for the gas fuel flows out from a position outside the primary air outlet in the radial direction (D4) of the gas fuel ejection portion, in a front view seen along the axial direction of the gas fuel ejection portion, The second burner includes a recirculation region (R) in which an imaginary line (X) extending radially from a center of the gas fuel jet does not intersect with the secondary air outlet.

[0057] Hydrogen has a faster burning speed and better combustibility than carbon fuels. For this reason, a burner that burns a gas fuel containing hydrogen (hydrogen burner) has a smaller theoretical amount of combustion air compared to a burner that burns a mixture containing carbon fuel (coal burner). According to the configuration described in [1] above, the combustion equipment includes a first burner that burns a mixture containing carbon fuel and a second burner that burns a gas fuel containing hydrogen. For this reason, the power required for the combustion equipment to supply combustion air can be reduced compared to when the combustion equipment is equipped with only multiple first burners (single-burning coal).

[0058] When a gas fuel containing hydrogen is mixed with primary air for the gas fuel and burned, and then secondary air for the gas fuel is further mixed to burn the unburned gas fuel, the generation of NOx is greatly suppressed by flowing exhaust gas into the region where the gas fuel and the primary air for the gas fuel are mixed and burned. According to the configuration described in [1] above, the second burner can flow exhaust gas into the above-mentioned region through the recirculation region. This makes it possible to suppress the generation of NOx.

[0059] Furthermore, according to the configuration described in [1] above, since the second burner is provided adjacent to the first burner, when the primary air for the gas fuel or the secondary air for the gas fuel is greater than the amount required for combustion of the gas fuel, this excess combustion air can be used for burning the mixture.

[0060] [2] In some embodiments, in the configuration described in [1] above, The at least one second secondary air flow path portion includes: a second secondary air flow path portion (34A) on one side having a first cylindrical portion (40) having a cylindrical shape with one end opened, the opening being configured as the secondary air outlet; a second secondary air flow path portion (34B) on the other side having a second cylindrical portion (42) having an open end, the opening being configured as the secondary air outlet, the opening of the first cylindrical portion is located on the opposite side of the opening of the second cylindrical portion across the primary air outlet in the up-down direction (D5), The second burner is disposed above the first burner, In the left-right direction (D6), the air-fuel mixture ejection portion and the gas fuel ejection portion at least partially overlap each other.

[0061] According to the configuration described in [2] above, the recirculation region is easily formed by providing the first cylindrical portion and the second cylindrical portion. The second burner is disposed above the first burner, so that the time during which the carbonaceous fuel is burned in the furnace (the residence time of the burning carbonaceous fuel) can be extended, and the amount of unburned carbonaceous fuel can be reduced. Furthermore, the unburned carbonaceous fuel can be gasified (C+H2O→CO+H2) by the steam generated by the combustion of hydrogen, and the amount of unburned carbonaceous fuel can be reduced.

[0062] [3] In some embodiments, in the configuration described in [2] above, The fuel injection apparatus further includes an outlet adjustment device (52) for changing the position of the outlet (29) of the gas fuel outlet portion in the vertical direction.

[0063] According to the configuration described in [3] above, by lowering the position of the outlet of the gas fuel outlet, the gas fuel injected into the furnace approaches the air-fuel mixture injected into the furnace. This can promote the gasification of unburned carbon fuel by steam. On the other hand, if the gas fuel is brought closer to the air-fuel mixture in the furnace, the combustion temperature in the furnace may rise, which may increase the amount of NOx generated. For this reason, by raising the position of the outlet of the gas fuel outlet, the gas fuel is separated from the air-fuel mixture in the furnace, which can suppress the generation of NOx.

[0064] [4] In some embodiments, in the configuration described in [3] above, The gas fuel ejection portion is configured so that the ejection direction can be tilted vertically.

[0065] According to the configuration described in [4] above, the gas fuel can be brought closer to the air-fuel mixture in the furnace, and the gas fuel can be moved farther away from the air-fuel mixture.

[0066] [5] In some embodiments, in the configuration described in [3] or [4] above, An acquisition unit (72) that acquires at least one of a concentration (B1) of nitrogen oxides contained in the exhaust gas (G) of the furnace and an amount (B5) of unburned carbon fuel; The control device (70) further includes an instruction unit (74) that instructs the nozzle adjustment device to change the position of the nozzle of the gas fuel nozzle section, which is calculated based on at least one of the concentration of nitrogen oxides contained in the exhaust gas acquired by the acquisition unit and the amount of unburned carbon fuel.

[0067] According to the configuration described in [5] above, the amount of unburned carbon fuel and the amount of NOx generated can be automatically and suitably adjusted. [Explanation of symbols]

[0068] 1 Combustion equipment 2 Furnace 3 Heavy Oil Nozzle 3a Outer wall surface of heavy oil nozzle 4. First burner 5 Heavy oil flow path 6. Second burner 8. Air-fuel mixture outlet 8a Inner wall surface of mixer outlet (sleeve) 8b Outer wall surface of mixer outlet (sleeve) 9 Mixture flow path 10 Flame holder 12 Pulverized coal concentrator 14 First secondary air flow path section 14a: Inner wall surface of the first secondary air flow passage portion (sleeve) 15 Secondary air passage (first burner) 16 Tertiary air flow path forming section 17 Outlet of first secondary air flow passage section 18 Tertiary air passage 19 Tip of first secondary air flow passage 20 Combustion space 21 Furnace wall 23 Throat 29 spout 30 Gas fuel ejection section 30a Outer wall surface of gas fuel nozzle 32 Primary air flow passage 32a Inner wall surface of primary air flow passage (sleeve) 33 Primary air passage 34 Second secondary air flow passage section 34A Upper (one side) second secondary air flow passage section 34B: Second secondary air flow passage portion on the lower side (other side) 35 Primary air outlet 36 Flame holder 37 Secondary air passage (second burner) 39 Secondary air outlet 39A Secondary air outlet of the first cylindrical section 39B Secondary air outlet of second cylindrical section 40 First cylindrical portion 42 Second cylindrical section 50 Swing section 52 Spout adjustment device 54 Swing angle setting section 56 Transmission section 70 Control device 72 Acquisition Department 74 Instruction section 80 Measurement Sensor A1 Primary air for carbon fuels A2 Secondary air for carbon fuels A3 Tertiary Air for Carbon Fuels A4 Primary air for gas fuel A5 Secondary air for gas fuel B1 Concentration of nitrogen oxides in exhaust gas B2 Carbon fuel input B3 Gas fuel input B4 Heat recovery from exhaust gas B5 Unburned carbon fuel content B6 adjustment signal D1 1st axis direction D2 1st radial direction D3 2nd axis direction D4 Second radial direction D5 Vertical direction D6 Left / right direction F1 Carbon Fuel F2 gas fuel FA mixture Fo heavy oil G. Exhaust gas O1 Axis of the mixture outlet (sleeve) Axis of O2 gas fuel nozzle R recirculation area R1 First recirculation zone R2 Second recirculation zone X Virtual Line

Claims

1. The furnace and A first burner provided on a furnace wall of the furnace; A second burner is provided on the furnace wall of the furnace adjacent to the first burner, The first burner is A mixture ejection section that ejects a mixture of carbonaceous fuel and primary air for the carbonaceous fuel into the furnace; A first secondary air flow passage portion that surrounds at least a part of the periphery of the mixture ejection portion in a front view seen along the axial direction of the mixture ejection portion and forms an outlet through which the secondary air for the carbon fuel flows out, The second burner is a gas fuel ejection section that ejects a gas fuel containing hydrogen into the furnace; a primary air flow path portion that surrounds the gas fuel ejection portion in a front view seen along an axial direction of the gas fuel ejection portion and forms a primary air outlet through which primary air for the gas fuel flows out; at least one second secondary air flow path portion in which a secondary air outlet is formed at a radially outer side of the gas fuel jetting portion relative to the primary air outlet in a front view seen along the axial direction of the gas fuel jetting portion, The second burner includes a recirculation region in which an imaginary line extending in the radial direction from a center of the gas fuel ejection portion does not intersect with the secondary air outlet. Combustion equipment.

2. The at least one second secondary air flow path portion includes: a second secondary air flow path portion on one side having a first cylindrical portion having a cylindrical shape with one end opened, the first cylindrical portion being configured as the secondary air outlet, a second secondary air flow path portion on the other side having a second cylindrical portion having a cylindrical shape with one end opened, the opening being configured as the secondary air outlet, the opening of the first cylindrical portion is located on an opposite side to the opening of the second cylindrical portion across the primary air outlet in the up-down direction, The second burner is disposed above the first burner, In the left-right direction, the air-fuel mixture ejection portion and the gas fuel ejection portion at least partially overlap each other. The combustion facility according to claim 1.

3. The fuel injection device further includes an injection port adjustment device that changes the position of the injection port of the gas fuel injection part in the vertical direction. The combustion facility according to claim 2.

4. The gas fuel ejection section is configured so that the ejection direction can be tilted along the vertical direction. The combustion facility according to claim 3.

5. An acquisition unit that acquires at least one of a concentration of nitrogen oxides contained in the exhaust gas of the furnace and an amount of unburned carbon fuel; and an instruction unit that instructs the nozzle adjustment device to change the position of the nozzle of the gas fuel nozzle unit calculated based on at least one of the concentration of nitrogen oxides contained in the exhaust gas acquired by the acquisition unit and the amount of unburned carbon fuel, The combustion facility according to claim 3 or 4.

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