TW202338263A - Ammonia combustion burner and boiler - Google Patents

Abstract

An ammonia combustion burner according to at least one embodiment of the present disculosure is an ammonia combustion burner for causing an ammonia fuel to combust in a boiler, and comprises: an ammonia spray nozzle for spraying the ammonia fuel; a combustion air nozzle for jetting air for combustion from outside of the ammonia spray nozzle; and a flow rate distribution imparting part that imparts a flow rate distribution to the air for combustion which is jetted from the combustion air nozzle.

Description

Ammonia combustion burners and boilers

The present invention relates to ammonia combustion burners and boilers. This case claims priority based on Special Application No. 2021-209730 filed with the Japan Patent Office on December 23, 2021, the contents of which are cited here.

There is known a boiler in which ammonia is supplied to the furnace as fuel. For example, the boiler invented in Patent Document 1 performs ammonia mixed combustion in which ammonia and coal are burned together in the furnace. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2020-41748

[Problem to be solved by the invention]

When ammonia is burned with an ammonia-dedicated combustion burner, the ignition position or the amount of _NOx produced is easily affected by the flow rate or flow rate of the combustion air. Therefore, it is required to supply combustion air in a manner that stabilizes the ignition position and suppresses the generation of _NOx .

In view of the above, at least one embodiment of the present invention aims to stabilize the ignition position and suppress the generation of _NOx in an ammonia combustion burner and a boiler. [Technical means to solve problems]

(1) An ammonia combustion burner according to at least one embodiment of the present invention is an ammonia combustion burner for burning ammonia fuel in a boiler, and has: Ammonia injection nozzle, which is used to inject the aforementioned ammonia fuel; a combustion air nozzle for injecting combustion air from outside the ammonia injection nozzle; and A flow velocity distribution providing unit provides a flow velocity distribution to the combustion air before it is sprayed from the combustion air nozzle.

(2) The boiler of at least one embodiment of the present invention has: A stove containing a stove wall; and The ammonia combustion burner of the structure (1) above is provided on the furnace wall.

(3) The boiler of at least one embodiment of the present invention has: A stove containing a stove wall; The ammonia combustion burner with the structure of the above (1) is installed on the aforementioned furnace wall; and Other fuel burners are provided on the furnace wall at different positions from the ammonia combustion burners to burn fuels other than ammonia fuel. [Effects of the invention]

According to at least one embodiment of the present invention, in an ammonia combustion burner and a boiler, the ignition position is stabilized and the generation of _NOx is suppressed.

Hereinafter, several embodiments of the present invention will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the constituent parts described as embodiments or shown in the drawings are not intended to limit the scope of the present invention and are merely illustrative examples. For example, relative or absolute expressions indicating "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" etc. are not strictly It only indicates this arrangement, but also includes tolerances, or a state of relative displacement with an angle or distance to the extent that the same function can be obtained. For example, expressions that express the equal state of things such as "same", "equal", and "homogeneous" do not strictly express only the equal state, but also include tolerances or exist to the extent that they can obtain the same function. Poor condition. For example, the representation of a shape such as a rectangular shape or a cylindrical shape does not only express a geometrically strict rectangular shape, a cylindrical shape, etc., but includes concave and convex portions within the range in which the same effect can be obtained. Or the shape of chamfered parts, etc. On the other hand, expressions such as "having", "having", "having", "containing", or "having" a constituent element are not exclusive expressions that exclude the existence of other constituent elements.

<1． Overall structure of boiler system 1＞ FIG. 1 is a schematic structural diagram showing a boiler system 1 including a boiler using ammonia fuel and a fuel other than ammonia fuel as a main fuel according to this embodiment.

The boiler 10 included in the boiler system 1 of this embodiment burns ammonia fuel and fuels other than the ammonia fuel with a burner, and can produce superheated steam by exchanging heat with water supply or steam. of boilers. As other fuels, solid fuels such as biomass fuel or coal are used. Solid fuel is, for example, pulverized coal fuel obtained by finely pulverizing coal. Moreover, ammonia fuel is a liquid or gas containing ammonia.

The boiler 10 has a furnace 11, combustion devices 20 and 50, and a combustion gas passage 12. The stove 11 has a hollow shape of a square tube and is installed along the vertical direction. The furnace wall 101 constituting the inner wall of the furnace 11 is composed of a plurality of heat transfer tubes and connecting tube segments that connect the heat transfer tubes to each other. The heat generated by the combustion of fuel is circulated inside the heat transfer tubes. The water or steam is recovered through heat exchange, and the temperature rise of the furnace wall 101 is suppressed.

The combustion devices 20 and 50 are arranged in the lower area of the stove 11 . In this embodiment, the combustion device 20 is configured to inject pulverized coal fuel into the inside of the furnace 11 . Furthermore, the combustion device 50 is configured to inject ammonia fuel into the inside of the furnace 11 .

The combustion device 20 has a plurality of burners 21 installed on the furnace wall 101, and the combustion device 50 has a plurality of ammonia burners (ammonia combustion burners) 51. An injection nozzle (not shown) is provided at the front end of each burner 21 and is configured to inject pulverized coal fuel into the furnace 11 . Furthermore, an ammonia injection nozzle 52 is provided at the front end of each ammonia burner 51 (see, for example, FIG. 3 ). When a liquid ammonia injection method is used to inject liquid ammonia fuel into the furnace 11, the ammonia injection nozzle may be, for example, a two-fluid injection nozzle in which liquid ammonia is atomized by an atomized fluid such as steam and injected. A single fluid injection nozzle that injects only liquid ammonia fuel may also be used. Furthermore, when an ammonia gas injection method is used to inject gaseous ammonia fuel into the furnace 11, the ammonia injection nozzle may be a gas injection nozzle. In some embodiments of the present invention, the ammonia burner 51 is a dedicated combustion burner for ammonia. Thereby, as will be described later, in the ammonia-dedicated combustion burner, the ignition position can be stabilized and the generation of _NOx can be suppressed.

The burner 21 and the ammonia burner 51 are arranged at equal intervals along the circumferential direction of the furnace 11 (for example, four are provided at each corner of the square furnace 11) as a set, and Arrange multiple segments along the vertical direction. In the example of FIG. 1 , one set of burners 21 is arranged in two stages, and one set of ammonia burners 51 is arranged in four stages. In addition, in FIG. 1 , for the convenience of illustration, only two burners in one group are shown, and the symbols 21 and 51 are assigned to each group. The shape of the furnace, the number of burner stages, the number of burners per stage, the arrangement of the burners, etc. are not limited to this embodiment. Furthermore, the combustion method of the stove 11 in this embodiment is a rotating combustion method in which burners are installed at each corner to form spirally rotating flames in the stove 11. However, other combustion methods are also possible. The shape of the furnace 11 and the arrangement of the plurality of burners 21 and the plurality of ammonia burners 51 may be appropriately changed according to the combustion method used. Another combustion method is, for example, an opposing combustion method in which burners are provided on both sides of a pair of opposing furnace walls of the furnace 11 .

The burner 21 of the combustion device 20 is connected to a plurality of pulverizers 31A, 31B (hereinafter sometimes referred to as "pulverized coal fuel supply pipes 22") through a plurality of pulverized coal fuel supply pipes 22A, 22B (hereinafter sometimes referred to as "pulverized coal fuel supply pipes 22"). In the following, they are collectively referred to as "pulverizer 31"). The grinder 31 has, for example, a grinding platform (not shown) that is rotatably supported internally, and a plurality of grinding rollers (not shown) above the grinding platform that are rotatably supported in conjunction with the rotation of the grinding platform. Vertical roller crusher. The solid fuel crushed by the cooperative operation of the crushing roller and the crushing platform is transported to the classifier (shown in the figure) provided in the crusher 31 by the primary air (transport gas, oxidizing gas) supplied to the crusher 31 omitted). In the classifier, the pulverized coal fuel is classified into pulverized coal fuel having a particle size smaller than or equal to the particle size suitable for combustion by the burner 21 and briquette fuel having a particle size larger than the particle size. The pulverized coal fuel is supplied to the burner 21 through the pulverized coal fuel supply pipe 22 together with the primary air through the classifier. The coal fuel that has not passed through the classifier falls to the crushing platform due to its own weight inside the crusher 31 and is crushed again.

The primary air (transport gas, oxidizing gas) supplied to the grinder 31 is sent to the grinder 31 through the air duct 30 from a primary air fan 33 (PAF: Primary Air Fan) that sucks in outside air. The air pipe 30 is provided with: a hot air induction pipe 30A through which hot air heated by an air preheater (air heater) 42 among the air sent from the primary air blower 33 flows; and a cold air induction pipe 30B through which Among the air sent from the primary air blower 33, there flows cold air close to normal temperature that has not passed through the air preheater 42; and a transport gas flow path 30C that combines the hot air and the cold air to flow.

The ammonia burner 51 of the combustion device 50 is connected to the ammonia fuel supply unit 90 . The ammonia fuel supply unit 90 of this embodiment includes an ammonia tank 91 and an ammonia fuel supply pipe 92 for supplying ammonia fuel (for example, liquid ammonia) stored in the ammonia tank 91 to the combustion device 50 of the boiler 10 . When the ammonia gas injection method is used, a vaporizer (not shown) for vaporizing liquid ammonia may be provided in the ammonia fuel supply unit 90 . Furthermore, when the liquid ammonia injection method is adopted, the ammonia fuel supply unit 90 may further include an atomization fluid supply pipe (not shown) for supplying an atomization fluid for atomizing liquid ammonia to the combustion device 50 .

An air regulator (air box) 23 is provided outside the furnace 11 where the burner 21 and the ammonia burner 51 are installed, and one end of an air duct (air passage) 24 is connected to the air regulator 23 . The other end of the air duct 24 is connected to a forced draft fan (FDF) 32 . The air supplied from the blower fan 32 is heated by the air preheater 42 provided in the air duct 24, and is supplied to the burner as secondary air (combustion air, oxidizing gas) through the air regulator 23. 21, and is supplied to the ammonia burner 51 as combustion air (oxidizing gas), and is introduced into the interior of the furnace 11.

The combustion gas passage 12 is connected to the upper part of the furnace 11 in the vertical direction. The combustion gas passage 12 is provided with superheaters 102A, 102B, and 102C (hereinafter, sometimes collectively referred to as "superheaters 102") and reheaters 103A and 103B as heat exchangers for recovering the heat of the combustion gas. (Hereinafter, sometimes collectively referred to as the "reheater 103") and the economizer 104 perform heat exchange between the combustion gas generated in the furnace 11 and the water supply or steam flowing inside each heat exchanger. In addition, the arrangement and shape of each heat exchanger are not limited to the form shown in FIG. 1 .

A flue 13 for discharging the combustion gas superheated in the heat exchanger is connected to the downstream side of the combustion gas passage 12 . An air preheater (air heater) 42 is provided between the flue 13 and the air duct 24, and heat exchange is performed between the air flowing in the air duct 24 and the combustion gas flowing in the flue 13. The primary air supplied to the pulverizer 31 or the combustion air supplied to the burner 21 and the ammonia burner 51 is heated, thereby further recovering heat from the combustion gas after heat exchange with water or steam.

Furthermore, the flue 13 may be provided with a denitration device 43 at a position upstream of the air preheater 42 . The denitrification device 43 supplies a reducing agent that has the effect of reducing nitrogen oxides such as ammonia and urea water to the combustion gas flowing in the flue 13, so that the nitrogen oxides in the combustion gas to which the reducing agent is supplied are eliminated. The reaction between ( _NOx ) and the reducing agent is promoted by the catalytic action of the denitration catalyst provided in the denitration device 43, thereby removing and reducing nitrogen oxides in the combustion gas. A gas passage 41 is connected to the flue 13 on the downstream side of the air preheater 42 . The gas passage 41 is provided with an environmental device such as a dust collecting device 44 such as an electric dust collector that removes ash in the combustion gas, a desulfurizing device 46 that removes sulfur oxides, or a device that guides the exhaust gas. Induced Draft Fan (IDF: Induced Draft Fan) 45 introduced to these environmental devices. The downstream end of the gas channel 41 is connected to the chimney 47, and the combustion gas processed by the environmental device is discharged out of the system as exhaust gas.

In the boiler 10, if a plurality of pulverizers 31 are driven, the pulverized coal fuel that has been crushed and classified will be supplied to the burner 21 through the pulverized coal fuel supply pipe 22 together with primary air. And, ammonia fuel is supplied from the ammonia fuel supply unit 90 to the ammonia burner 51 . In addition, the secondary air heated by the air preheater 42 is supplied from the air duct 24 through the air regulator 23 to the burner 21 and the ammonia burner 51 . The burner 21 blows the pulverized coal fuel mixture into the furnace 11 and blows the secondary air into the furnace 11 . The pulverized coal-fuel mixture blown into the furnace 11 is ignited and reacts with the secondary air to form a flame. The ammonia burner 51 blows combustion air into the furnace 11 together with ammonia fuel. The ammonia fuel blown into the furnace 11 reacts with the combustion air and burns. The high-temperature combustion gas generated by the combustion of pulverized coal fuel and ammonia fuel rises in the furnace 11 and flows into the combustion gas passage 12 . Furthermore, the timing at which the ammonia fuel is blown into the furnace 11 may be after the temperature in the furnace 11 has been raised to a certain temperature by burning the pulverized coal fuel. For example, after the pulverized coal fuel is exclusively burned when the boiler 10 is started, the ammonia fuel is blown into the furnace 11 and ammonia mixed combustion of the ammonia fuel and the pulverized coal fuel may be performed. After that, the injection of pulverized coal fuel may be stopped and ammonia-only combustion may be performed. In addition, in this embodiment, air is used as the oxidizing gas (primary air, secondary air, combustion air), but the proportion of oxygen may be more or less than that of air. The amount of supplied oxygen may be The ratio of the fuel amount is adjusted to an appropriate range, thereby achieving stable combustion in the stove 11 .

The combustion gas flowing into the combustion gas passage 12 exchanges heat with water or steam through the superheater 102, the reheater 103, and the economizer 104 arranged inside the combustion gas passage 12, and then is discharged to the flue 13. Nitrogen oxides are removed by the denitrification device 43, and the air preheater 42 performs heat exchange with the primary air, secondary air and combustion air, and then is further discharged to the gas passage 41, and is discharged by the dust collection device 44. Ash, etc. are removed, and sulfur oxides are removed by the desulfurization device 46, and then are discharged from the chimney 47 to the outside of the system. In addition, the arrangement of each device from each heat exchanger in the combustion gas passage 12 and the flue 13 to the gas passage 41 does not necessarily need to be arranged in the order described above for the flow of the combustion gas.

In addition, the boiler of this invention is not limited to the said embodiment. As solid fuel used in boilers, biomass fuel, petroleum coke (PC: Petroleum Coke) fuel, petroleum residue, etc. can be used instead of coal or together with coal. Furthermore, the fuel for the boiler combined with ammonia fuel is not limited to solid fuel, and liquid fuel such as petroleum fuel such as heavy oil, light oil, heavy oil, or factory waste liquid may also be used. In addition, gaseous fuels such as natural gas, various petroleum gases, and by-product gases generated in the steelmaking process can also be used. In addition, it can also be applied to mixed combustion boilers that use a combination of these various fuels. In the following description, ammonia fuel will also be referred to as ammonia.

As described above, the boiler 10 according to at least one embodiment of the present invention is provided with the furnace 11 including the furnace wall 101, the ammonia burner 51 provided on the furnace wall 101 to be described in detail later, and the ammonia burner 51 provided on the furnace wall 101. The burner 51 has different positions and the pulverized coal burner that burns the pulverized coal is the burner 21. Thereby, in the ammonia burner 51 of the boiler 10 according to at least one embodiment of the present invention, the ignition position is stabilized and the generation of _NOx is suppressed. The burner 21 may be another fuel burner that burns fuel other than ammonia fuel. Also, pulverized coal burners are included in other fuel burners.

The boiler 10 according to at least one embodiment of the present invention may be a spiral combustion boiler in which the ammonia burner 51 and the burner 21 as a pulverized coal burner perform spiral combustion in the furnace 11. Thereby, in the ammonia burner 51 of the swirling combustion boiler, the ignition position is stabilized and the generation of _NOx is suppressed. In addition, the burner 21 may be another fuel burner that burns fuel other than ammonia fuel. Furthermore, the boiler 10 according to at least one embodiment of the present invention may be a mixed combustion boiler that combusts ammonia fuel and fuels other than ammonia fuel, or may be an ammonia-specific combustion boiler that combusts only ammonia fuel.

(Influence of the flow rate of the combustion air) When ammonia is burned with an ammonia-dedicated combustion burner, the ignition position or the amount of _NOx generated are easily affected by the flow rate or flow rate of the combustion air. Figure 2 is a schematic diagram illustrating the relationship between the flow rate and ignition position of the combustion air and the amount of _NO Take the 51X as an example. In the ammonia burner 51X shown in FIG. 2 , with the central axis Ax of the ammonia burner 51X along the flow of the combustion air as a boundary, the combustion air sprayed from the combustion air nozzle 54 is shown on the upper side of the figure. When the flow speed is relatively slow, the lower side of the figure shows a case where the flow speed of the combustion air sprayed from the combustion air nozzle 54 is relatively fast. The ammonia burner 51X shown in FIG. 2 is a diffusion combustion system (diffusion type) burner and includes an ammonia injection nozzle 52 for injecting ammonia, and an ammonia injection nozzle 52 for injecting combustion air from the outside of the ammonia injection nozzle 52 . Combustion air nozzle 54, flame retainer 56. In the ammonia burner 51X shown in FIG. 2 , the flame retainer 56 is, for example, a diffusion-type flame retainer 56A in the shape of a hollow truncated cone. In addition, "outside of the ammonia injection nozzle 52" refers to a region radially outside the ammonia injection nozzle 52 with the central axis Ax of the ammonia injection nozzle 52 as the center. The same applies to the following description.

In FIG. 2 , the range of the heat preservation area (the circulation flow generation area formed in the wake of the heat preservation device) 81 is surrounded by a dotted line. In FIG. 2 , the injection range 82 of ammonia injected from the ammonia injection nozzle 52 is schematically represented by a two-dot chain line. In FIG. 2 , the mixing position 83 of the combustion air injected from the combustion air nozzle 54 and the ammonia injected from the ammonia injection nozzle 52 is surrounded by a solid line and painted on the bottom of the screen.

When the flow rate of the combustion air is relatively slow, the flame-preserving area 81 is relatively small, and the ignitability tends to be relatively low. When the flow rate of the combustion air is relatively slow, the inertia of the combustion air becomes relatively small, so the combustion air tends to concentrate near the ignition part. Therefore, an area with relatively high air content (high oxygen concentration area) is formed locally, and the _NOx generation amount tends to change relatively much.

When the flow rate of the combustion air is relatively fast, the flame-preserving area 81 is relatively large, and the flammability tends to be relatively high. When the flow rate of the combustion air is relatively high, the inertia of the combustion air becomes relatively large, so the mixing positions 83 of the combustion air injected from the combustion air nozzle 54 and the ammonia injected from the ammonia injection nozzle 52 are dispersed downstream. side tendency. Therefore, the local formation of a high air ratio area is alleviated, and the amount of _NOx generation tends to become relatively small.

As shown in the ammonia burner 51X shown in Figure 2, when the flow path of the combustion air is a single flow path, the flow rate and flow rate of the combustion air will change simultaneously, so it is relatively difficult to adjust the ignition position of ammonia. Furthermore, during retarding to reduce the combustion amount of the burner, it is necessary to maintain the flow rate of the combustion air in order to ensure ignition. However, if the flow rate is maintained through a single flow path, the flow rate of the combustion air will become fixed. On the other hand, during idle, the amount of fuel injected will decrease, so the air ratio will increase, and _NOx will tend to increase. In particular, compared with other fuels, the amount of _NOx produced by ammonia is easily affected by the air ratio, so the control of the air ratio is very important. Therefore, even during retarding, combustion air must be supplied in a manner that stabilizes the ignition position and suppresses the generation of _NOx .

Here, in the boiler 10 of this embodiment, the ammonia burner 51 is configured as follows to maintain the flow rate of the combustion air during rated operation and slowdown, and to achieve an air ratio suitable for combustion in consideration of the generation of _NOx . . Hereinafter, several embodiments of the ammonia burner 51 will be described.

(About each embodiment of the ammonia burner 51) 3 is a side cross-sectional view schematically showing the structure of the first ammonia burner 51A according to one of the several embodiments of the ammonia burner 51, along the central axis Ax from the flow direction of the combustion air. The schematic front view of the first ammonia burner 51A is viewed from the downstream side. FIG. 4 is a schematic diagram showing an example of a structure for driving the flow velocity distribution providing part 60 described later on the first ammonia burner 51A shown in FIG. 3 . 5A, 5B, and 5C are schematic diagrams for explaining the function of the flow velocity distribution providing part 60 of the first ammonia burner 51A shown in FIG. 3. In addition, in FIG. 3 , FIG. 5A , FIG. 5B , and FIG. 5C , description of the structure for driving the flow velocity distribution imparting part 60 is omitted. 6A, 6B, and 6C are schematic diagrams for explaining the structure of the second ammonia burner 51B of other embodiments and the function of the flow velocity distribution providing part 60 among the ammonia burners 51 of several embodiments. 7A, 7B, and 7C are schematic diagrams for explaining the structure of the third ammonia burner 51C of other embodiments and the function of the flow velocity distribution providing part 60 in the ammonia burner 51 of several embodiments. . 8A, 8B, and 8C are schematic diagrams for explaining the structure of the fourth ammonia burner 51D of other embodiments and the function of the flow velocity distribution providing part 60 in the ammonia burner 51 of several embodiments. A side sectional view and a schematic front view of the fourth ammonia burner 51D viewed from the downstream side in the flow direction of the combustion air along the central axis Ax. 9 is a schematic side cross-sectional view for explaining the structure of the fifth ammonia burner 51E of another embodiment and the function of the flow velocity distribution providing part 60 among the ammonia burners 51 of the several embodiments. A schematic front view of the fifth ammonia burner 51E as viewed from the downstream side in the flow direction of the combustion air with the central axis Ax. 10 is a schematic side cross-sectional view for explaining the structure of the sixth ammonia burner 51F of another embodiment and the function of the flow velocity distribution providing part 60 among the ammonia burners 51 of the several embodiments. A schematic front view of the sixth ammonia burner 51F when the central axis Ax is viewed from the downstream side in the flow direction of the combustion air. 11 is a schematic side cross-sectional view for explaining the structure of the seventh ammonia burner 51G of another embodiment and the function of the flow velocity distribution providing part 60 among the ammonia burners 51 of the several embodiments. A schematic front view of the seventh ammonia burner 51G when the central axis Ax is viewed from the downstream side in the flow direction of the combustion air. 12 is a schematic side cross-sectional view for explaining the structure of the eighth ammonia burner 51H of another embodiment and the function of the flow velocity distribution providing part 60 among the ammonia burners 51 of the several embodiments. A schematic front view of the eighth ammonia burner 51H as viewed from the downstream side in the flow direction of the combustion air with the central axis Ax.

In the following description, when the ammonia burners 51A, 51B, 51C, 51D, 51E, 51F, 51G, and 51H are collectively referred to as each ammonia burner, it is not necessary to distinguish between the ammonia burners 51A, 51B, 51C, 51D, 51E, In the case of 51F, 51G, and 51H, the symbols are omitted and only represent the ammonia burner 51. In addition, in the following description, within the extending direction of the central axis Ax of the ammonia burner 51, the downstream side in the flow direction of the combustion air will be simply referred to as the downstream side, and the upstream side in the flow direction of the combustion air will be referred to as the downstream side. Referred to as the upstream side.

(About the first ammonia burner 51A) The first ammonia burner 51A shown in Fig. 3 is a diffusion type burner and includes an ammonia injection nozzle 52 for injecting ammonia, and a combustion air for injecting combustion air from the outside of the ammonia injection nozzle 52. The nozzle 54 , the flame retainer 56 , and the flow velocity distribution providing part 60 . In the first ammonia burner 51A shown in FIG. 3 , the flame retainer 56 is, for example, a hollow truncated cone-shaped diffusion type flame retainer 56A.

In the first ammonia burner 51A shown in FIG. 3 , the combustion air nozzle 54 has a rectangular shape when viewed along the central axis Ax and is a passage with a rectangular cross section. It is formed near the downstream end. The cross-sectional area of the flow path is reduced toward the downstream side while maintaining the rectangular cross-sectional shape. By forming the constriction portion as described above, it is possible to suppress a decrease in flow velocity in the cross-sectional peripheral portion of the passage wall surface from affecting the flow velocity distribution of the opening portion 54 a at the downstream end of the combustion air nozzle 54 .

In the first ammonia burner 51A shown in FIG. 3, the ammonia injection nozzle 52 is coaxially arranged with the combustion air nozzle 54, and is configured to inject ammonia into the furnace 11 from a plurality of injection holes 52h. Furthermore, in the first ammonia burner 51A shown in FIG. 3 , in order to avoid interference with the flow velocity distribution imparting part 60 , the ammonia injection nozzle 52 has its upstream nozzle pipe directed inward or outward in the drawing in FIG. 3 . The drawing can also be extended in the up and down direction.

In the first ammonia burner 51A shown in FIG. 3, the combustion air supplied to the combustion air nozzle 54 is supplied from the opening 54a of the outlet of the combustion air nozzle 54 and the outer peripheral end of the diffusion type flame retainer 56A. The gap between them is sprayed into the furnace 11 .

In the first ammonia burner 51A shown in FIG. 3 , the flow velocity distribution providing unit 60 is configured to provide a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54 . More specifically, in the first ammonia burner 51A shown in FIG. 3 , the flow velocity distribution imparting part 60 is the first flow velocity distribution imparting part 61 , which is arranged inside the combustion air nozzle 54 . For the combustion air nozzle, The combustion air flowing inside the 54 imparts a flow velocity distribution. In the first ammonia burner 51A shown in FIG. 3 , the first flow velocity distribution portion 61 includes a flow path restricting member 611 , which is formed to form a flow path from the combustion air nozzle 54 when viewed along the central axis Ax of the combustion air nozzle 54 . The center of the air nozzle 54 extends toward the outside. The flow path restricting member 611 forms a gap through which the combustion air can flow, and the inner peripheral surface 54i of the combustion air nozzle 54 .

In the first ammonia burner 51A shown in FIG. 3, the position of the first flow velocity distribution imparting part 61 (flow path restricting member 611) along the central axis Ax is used to make the air ejected from the combustion air nozzle 54 The flow velocity distribution of combustion air changes. In addition, in FIGS. 5A, 5B, and 5C, the arrows described on the downstream side than the outlet of the combustion air nozzle 54 indicate the flow rate of the combustion air sprayed from the opening 54a at the downstream end of the combustion air nozzle 54. The tendency of the distribution, that is, the relationship between the distance from the central axis Ax and the flow rate of the combustion air.

(When the flow path restricting member 611 is located relatively far from the opening 54a) FIG. 5A shows a case where the flow path restricting member 611 is located relatively far from the opening 54 a , that is, a case where the flow path restricting member 611 is located relatively upstream. The combustion air is guided to the gap by the flow path restricting member 611 away from the central axis Ax, as shown by arrow a in FIG. 5A . A part of the combustion air guided to the above-mentioned gap is located further downstream than the downstream end 611d of the flow path restricting member 611, and is close to the central axis by the inertial force of the fluid as shown by arrow b in Fig. 5A The way Ax flows. Therefore, as the opening 54a approaches the outlet of the combustion air nozzle 54, the flow velocity approaches a uniform state in the cross section of the combustion air nozzle 54 orthogonal to the central axis Ax. As shown in FIG. 5A , when the flow path restricting member 611 is located on the upstream side, the flow velocity is closer to a uniform state in the cross section of the combustion air nozzle 54 that is orthogonal to the central axis Ax. That is, when the flow path restricting member 611 is located relatively upstream, the flow path restricting member 611 hardly affects the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 . Thereby, as shown in FIG. 5A , when the flow path restricting member 611 is located on the relatively upstream side, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 will be the flow velocity distribution regardless of the position of the central axis Ax. become relatively equal flow rates.

(When the flow path restriction member 611 is present at a position relatively close to the opening 54a) FIG. 5C shows a case where the flow path restriction member 611 is present at a position relatively close to the opening 54a, that is, the flow path restriction member 611 Located on the relatively downstream side. The combustion air is guided to the gap by the flow path restricting member 611 away from the central axis Ax, for example, as indicated by arrow d in FIG. 5C . As shown in FIG. 5C , when the flow path restricting member 611 is located on the relatively downstream side, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is affected by the flow of the combustion air as indicated by arrow d. , is a flow velocity distribution in which the flow velocity is faster at a position farther from the central axis Ax than at a position closer to the central axis Ax. In the case of such a flow velocity distribution, it is easy to supply combustion air to a position relatively far from the ignition point, so it is difficult to form a local area with relatively high air, and it is expected that the amount of _NOx generated can be suppressed.

(When the flow path restricting member 611 is close to the opening 54a to some extent) FIG. 5B shows a situation where the flow path restricting member 611 is close to the opening 54a to some extent, for example, between the position of the flow path restricting member 611 shown in FIG. 5A and the position of the flow path restricting member 611 shown in FIG. 5C . The flow path restricting member 611 may be present at the position. The combustion air is guided to the gap by the flow path restricting member 611 away from the central axis Ax, as shown by arrow c in FIG. 5B . A part of the combustion air guided to the gap flows downstream from the downstream end 611d of the flow path restricting member 611 so as to be close to the central axis Ax. However, in the case shown in Fig. 5B, the distance between the downstream end 611d of the flow path restricting member 611 and the opening 54a is shorter than in the case shown in Fig. 5A. Therefore, in the area relatively close to the central axis Ax, the flow velocity is not Will respond fully. Therefore, as shown in FIG. 5B , when the flow path restricting member 611 is close to the opening 54 a to some extent, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 becomes such that the flow velocity is closer to the central axis Ax. The position will have a faster flow velocity distribution than the position farther from the central axis Ax. In the case of such a flow velocity distribution, by increasing the flow velocity of the combustion air around the flame retaining device 56, a flame retaining area (circulation area) can be fully formed, thereby improving ignition properties.

The first ammonia burner 51A shown in FIG. 3 can be configured so that the position of the first flow velocity distribution providing part 61 (flow path restricting member 611) along the central axis Ax can be changed even during operation of the boiler 10. . For example, in the first ammonia burner 51A shown in FIG. 3 , as shown in FIG. 4 , the flow velocity distribution imparting part 60 may also include a moving device 613 configured to move the flow path restricting member 611 along the central axis Ax. Move. For example, the moving device 613 may include a driving source 615 for moving the flow path restricting member 611 along the central axis Ax. As the driving source 615, a hydraulic cylinder or an electric cylinder is used, for example. Furthermore, for example, the driving source 615 and the flow path restricting member 611 may be connected by a rod 616, and the flow path restricting member 611 may be moved along the central axis Ax through the rod 616. Furthermore, as shown in FIG. 4 , the flow path restricting member 611 may be configured to be guided along the central axis Ax by a guide rail 617 or the like arranged inside the combustion air nozzle 54 .

The first ammonia burner 51A shown in FIG. 3 provides a flow velocity distribution to the combustion air blown out from the combustion air nozzle 54, thereby stabilizing the ignition position and suppressing the generation of _NOx .

In the first ammonia burner 51A shown in FIG. 3 , the first flow velocity distribution imparting part 61 (flow path restricting member 611 ) arranged inside the combustion air nozzle 54 makes it easier to control the flow from the combustion air nozzle 54 The jetted combustion air imparts flow velocity distribution.

In the first ammonia burner 51A shown in FIG. 3, the combustion air is guided to the above-mentioned gap, thereby making it possible to increase the flow rate of the combustion air when viewed along the central axis Ax of the combustion air nozzle 54. The central region and the outer region of the combustion air nozzle 54 are different. Thereby, flow velocity distribution can be provided to the combustion air sprayed from the combustion air nozzle 54 .

In the first ammonia burner 51A shown in FIG. 3 , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is affected by the position of the flow path restricting member 611 in the extending direction of the central axis Ax. Therefore, by changing the position of the flow path restricting member 611 in the extending direction of the central axis Ax by the moving device 613, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 can be changed. Thereby, even if the flow rate of the combustion air changes during slowdown, for example, by changing the position of the flow path restricting member 611 in the extending direction of the central axis Ax, the ignition position can be stabilized and the generation of _NOx can be suppressed.

Furthermore, in the first ammonia burner 51A shown in FIG. 3 , the position of the first flow velocity distribution portion 61 (flow path restricting member 611 ) along the central axis Ax is fixed at a preset position, and is configured as follows It does not matter that the position cannot be changed while the boiler 10 is in operation.

(About the second ammonia burner 51B) The second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C is the same as the first ammonia burner 51A shown in FIG. 3. It is a diffusion type burner and is equipped with: The ammonia injection nozzle 52 , the combustion air nozzle 54 for injecting combustion air from the outside of the ammonia injection nozzle 52 , the flame retainer 56 , and the flow velocity distribution providing part 60 . The second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C is the same as the first ammonia burner 51A shown in FIG. 3 , and the flame retainer 56 is, for example, a diffusion-type flame retainer 56A.

In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the combustion air nozzle 54 has the same structure as the first ammonia burner 51A shown in FIG. 3 .

The second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C is the same as the first ammonia burner 51A shown in FIG. 3. The ammonia injection nozzle 52 is coaxially arranged with the combustion air nozzle 54. , is configured to inject ammonia into the furnace 11 from a plurality of injection holes 52h. In addition, the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C is the same as the first ammonia burner 51A shown in FIG. 3. The ammonia injection nozzle 52 has a nozzle pipe on the upstream side. 6A, 6B, and 6C may extend inward in the drawing or in the up-down direction in the drawing, or they may not be configured in this way.

The second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C is the same as the first ammonia burner 51A shown in FIG. 3. The combustion air supplied to the combustion air nozzle 54 is from The air is injected into the furnace 11 through the gap between the opening 54a of the outlet of the combustion air nozzle 54 and the outer peripheral end of the diffusion type flame holder 56A.

In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, similar to the first ammonia burner 51A shown in FIG. 3, the flow velocity distribution imparting part 60 is configured to provide combustion air from The combustion air blown out from the nozzle 54 is provided with a flow velocity distribution. More specifically, the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C is the same as the first ammonia burner 51A shown in FIG. 3 , and the flow velocity distribution providing part 60 is the first flow velocity The distribution providing unit 61 is disposed inside the combustion air nozzle 54 and provides a flow velocity distribution to the combustion air flowing inside the combustion air nozzle 54 . In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the first flow velocity distribution portion 61 includes a guide piece 612 having a predetermined inclination angle θ with respect to the extension direction of the central axis Ax. to the inclined guide surface 612a.

In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the guide piece 612 is arranged along each side of the combustion air nozzle 54 having a rectangular cross section, and at least one guide piece 612 is arranged on each side. Can. For example, in the examples shown in FIGS. 6A, 6B, and 6C, a guide piece is disposed on each side of the combustion air nozzle 54 having a rectangular cross-section, and on the two sides separated in the vertical direction as shown in the figure. 612, a guide piece 612 is respectively arranged on the two sides (not shown) that are separated toward the inner direction of the figure. In addition, for example, as in the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C to be described later, the guide piece 612 is formed along each side of the combustion air nozzle 54 having a rectangular cross section. A plurality of segments may be arranged in a direction orthogonal to the central axis Ax. Furthermore, the guide pieces 612 may be arranged in plural numbers along each side of the combustion air nozzle 54 having a rectangular cross section in the extending direction of the side. The guide pieces 612 may be arranged in plural numbers in the extending direction of the central axis Ax. In addition, the guide pieces 612 are respectively arranged on two sides separated in the up-down direction as shown in the figure, and may not be respectively arranged on two sides (not shown) separated in the inward direction as shown in the figure. Furthermore, the guide pieces 612 may be arranged on two sides (not shown) that are separated in the inward direction of the figure, instead of being arranged on two sides separated in the up-down direction as shown in the figure.

In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the flow velocity distribution of the combustion air blown from the combustion air nozzle 54 is changed by the inclination angle θ of the guide surface 612a. In addition, in FIGS. 6A, 6B, and 6C, the arrows described on the downstream side than the outlet of the combustion air nozzle 54 indicate the flow rate of the combustion air sprayed from the opening 54a at the downstream end of the combustion air nozzle 54. The tendency of the distribution, that is, the relationship between the distance from the central axis Ax and the flow rate of the combustion air.

(When the tilt angle θ is 0 degrees) FIG. 6A shows a case where the inclination angle θ of the guide surface 612a of the guide piece 612 is 0 degrees. In the case shown in FIG. 6A , the guide surface 612a of the guide piece 612 does not guide the combustion air flowing through the combustion air nozzle 54 close to the central axis Ax, nor does it guide it away from the central axis Ax. . Thereby, in the case shown in FIG. 6A , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 becomes a relatively equal flow velocity regardless of the position of the central axis Ax.

(When the guide surface 612a approaches the central axis Ax toward the downstream side) FIG. 6B shows a case where the inclination angle θ is set so that the guide surface 612a approaches the central axis Ax as it goes toward the downstream side. In the case shown in FIG. 6B, the combustion air is guided toward the central axis Ax by the guide surface 612a. Therefore, in the case shown in FIG. 6B , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is such that the flow velocity is faster at a position closer to the central axis Ax than at a position farther from the central axis Ax. flow velocity distribution.

(When the guide surface 612a is moved away from the central axis Ax toward the downstream side) FIG. 6C shows a case where the inclination angle θ is set so that the guide surface 612a moves away from the central axis Ax as it goes toward the downstream side. In the case shown in FIG. 6C , the combustion air is guided away from the central axis Ax by the guide surface 612a. Therefore, in the case shown in FIG. 6C , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is such that the flow velocity is faster at a position farther from the central axis Ax than at a position closer to the central axis Ax. flow velocity distribution.

The second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C can be configured so that the inclination angle θ of the guide surface 612a can be changed even during operation of the boiler 10. For example, in the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the flow velocity distribution portion 60 may include a guide plate driving device 614 configured to change the inclination angle θ of the guide surface 612a. . The guide piece driving device 614 may include a drive source (not shown) for changing the inclination angle θ of the guide surface 612a, and a drive source configured to transmit the driving force of the drive source to change the guide surface 612a. A communication device (not shown) for the tilt angle θ.

The second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C provides a flow velocity distribution to the combustion air blown out from the combustion air nozzle 54, thereby stabilizing the ignition position and suppressing _NOx. of production.

In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the first flow velocity distribution providing part 61 (guide piece 612) arranged inside the combustion air nozzle 54 makes it easier to The combustion air sprayed from the combustion air nozzle 54 is provided with a flow velocity distribution.

In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the guide piece 612 is used to guide the combustion air, so that when viewed along the central axis Ax of the combustion air nozzle 54 , the flow velocity of the combustion air can be made different between the central area and the outer area of the combustion air nozzle 54 . Thereby, flow velocity distribution can be provided to the combustion air sprayed from the combustion air nozzle 54 .

In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the flow velocity distribution of the combustion air blown from the combustion air nozzle 54 is affected by the above-mentioned inclination angle θ. Then, by changing the inclination angle θ with the guide vane driving device 614, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 can be changed. Thereby, even if the flow rate of the combustion air changes during slowdown, for example, by changing the inclination angle θ, the ignition position can be stabilized and the generation of _NOx can be suppressed.

In the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C, the guide surface 612a is fixed at an angle where the above-mentioned inclination angle θ is set in advance, and the above-mentioned inclination angle θ cannot be changed during the operation of the boiler 10. The tilt angle θ is also acceptable.

(About the third ammonia burner 51C) The third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C is a diffusion type burner similar to the first ammonia burner 51A shown in FIG. 3, and is equipped with: The ammonia injection nozzle 52 , the combustion air nozzle 54 for injecting combustion air from the outside of the ammonia injection nozzle 52 , the flame retainer 56 , and the flow velocity distribution providing part 60 . The third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C is the same as the first ammonia burner 51A shown in FIG. 3 , and the flame retainer 56 is, for example, a diffusion-type flame retainer 56A.

In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the combustion air nozzle 54 has the same structure as the first ammonia burner 51A shown in FIG. 3.

The third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C is the same as the first ammonia burner 51A shown in FIG. 3. The ammonia injection nozzle 52 is coaxially arranged with the combustion air nozzle 54. , is configured to inject ammonia into the furnace 11 from a plurality of injection holes 52h. In addition, the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C is the same as the first ammonia burner 51A shown in FIG. 3. The ammonia injection nozzle 52 has a nozzle pipe on the upstream side. 7A, 7B, and 7C may extend inward in the drawing or in the up-down direction in the drawing.

The third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C is the same as the first ammonia burner 51A shown in FIG. 3. The combustion air supplied to the combustion air nozzle 54 is from The air is injected into the furnace 11 through the gap between the opening 54a of the outlet of the combustion air nozzle 54 and the outer peripheral end of the diffusion type flame holder 56A.

In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, similar to the first ammonia burner 51A shown in FIG. 3, the flow velocity distribution providing part 60 is configured to provide combustion air from The combustion air blown out from the opening 54a at the downstream end of the nozzle 54 is given a flow velocity distribution. More specifically, the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C is the same as the first ammonia burner 51A shown in FIG. 3, and the flow velocity distribution providing part 60 is the first flow velocity The distribution providing unit 61 is disposed inside the combustion air nozzle 54 and provides a flow velocity distribution to the combustion air flowing inside the combustion air nozzle 54 . In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the first flow velocity distribution portion 61 includes a guide piece 612 having a predetermined inclination angle θ with respect to the extension direction of the central axis Ax. to the inclined guide surface 612a. In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the first flow velocity distribution providing part 61 is included in the combustion air nozzle 54 and is arranged inward of the guide piece 612. Regional flow restrictor 618. The flow restrictor 618 can adjust the flow rate of the combustion air passing through this area (ie, the flow restrictor 618).

In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the guide piece 612 is directed perpendicularly to the central axis Ax along each side of the combustion air nozzle 54 having a rectangular cross section. It is also possible to configure multiple segments in the intersection direction. In the example shown in FIGS. 7A, 7B, and 7C, the guide piece 612 is arranged in two sections on each side in a direction orthogonal to the central axis Ax. In addition, in the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the above-mentioned number of arrangement stages of the guide piece 612 is the same as that in the second ammonia burner 51C shown in FIGS. 6A, 6B, and 6C. The burner 51B may also be one-stage in the same manner. Furthermore, the guide pieces 612 may be arranged in plural numbers along each side of the combustion air nozzle 54 having a rectangular cross section in the extending direction of the side. The guide pieces 612 may be arranged in plural numbers in the extending direction of the central axis Ax. In addition, the guide pieces 612 are respectively arranged on two sides separated in the up-down direction as shown in the figure, and may not be respectively arranged on two sides (not shown) separated in the inward direction as shown in the figure. Furthermore, the guide pieces 612 may be arranged on two sides (not shown) that are separated in the inward direction of the figure, instead of being arranged on two sides separated in the up-down direction as shown in the figure.

In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the flow velocity distribution of the combustion air blown from the combustion air nozzle 54 is changed by the inclination angle θ of the guide surface 612a. Furthermore, in the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the flow rate of the combustion air passing through the flow limiter 618 is limited by the flow limiter 618, thereby allowing the flow rate of the combustion air to pass through the limiter 618. The flow rate of the combustion air on the outer peripheral side of the flow device 618 increases. Therefore, in the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, by adjusting the inclination angle θ of the guide surface 612a and the opening of the flow restrictor 618, the combustion air can be changed. The flow velocity distribution of the combustion air ejected from the nozzle 54. In addition, in FIGS. 7A, 7B, and 7C, the arrows described on the downstream side than the outlet of the combustion air nozzle 54 indicate the flow rate of the combustion air sprayed from the opening 54a at the downstream end of the combustion air nozzle 54. The tendency of the distribution, that is, the relationship between the distance from the central axis Ax and the flow rate of the combustion air.

(When the tilt angle θ is 0 degrees and the flow limiter 618 does not restrict contraction) FIG. 7A shows a case where the inclination angle θ of the guide surface 612a of each guide piece 612 is 0 degrees, and the flow rate of the combustion air passing through the flow restrictor 618 is not restricted. In the case shown in FIG. 7A , the guide surface 612a of the guide piece 612 does not guide the combustion air flowing through the combustion air nozzle 54 close to the central axis Ax, nor does it guide it away from the central axis Ax. . Furthermore, the flow rate of the combustion air passing through the flow restrictor 618 is not restricted, so the flow rate of the combustion air passing through the outer peripheral side of the flow limiter 618 does not increase. Thereby, in the case shown in FIG. 7A , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 becomes a relatively equal flow velocity regardless of the position of the central axis Ax.

(When the guide surface 612a approaches the central axis Ax toward the downstream side) 7B shows that among the guide pieces 612 arranged in two stages on the outer circumferential side and the inner circumferential side with the central axis Ax as the center, the inclination angle θ is set for the guide piece 612 on the outer circumferential side so as to move toward the downstream side. And the guide surface 612a is brought close to the central axis Ax. Furthermore, among the guide pieces 612 arranged in two stages on the outer circumferential side and the inner circumferential side with the central axis Ax as the center, the inclination angle θ is set so that the inclination angle θ increases toward the downstream as well for the inner circumferential side guide piece 612 . Alternatively, the guide surface 612a may be brought closer to the central axis Ax. In the case shown in FIG. 7B , the combustion air is guided toward the central axis Ax by the guide surface 612 a of the guide piece 612 on the outer peripheral side. In the case shown in FIG. 7B , the guide piece 612 on the outer peripheral side is tilted to increase the pressure loss and restrict the flow through the restriction without reducing the flow rate of the combustion air flowing on the outer peripheral side of the combustion air nozzle 54 . The flow rate of the combustion air of the device 618 can also be changed. In addition, as long as the flow rate of the combustion air flowing on the outer peripheral side of the combustion air nozzle 54 is not reduced, the flow rate of the combustion air passing through the flow restrictor 618 does not need to be restricted. Therefore, in the case shown in FIG. 7B , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is such that the flow velocity is faster at a position closer to the central axis Ax than at a position farther from the central axis Ax. flow velocity distribution.

(When the guide surface 612a is moved away from the central axis Ax toward the downstream side) 7C shows that among the guide pieces 612 arranged in two stages on the outer circumferential side and the inner circumferential side with the central axis Ax as the center, the inclination angle θ is set for the inner circumferential side guide piece 612 so as to go downstream. The guide surface 612a is moved sideways away from the central axis Ax. Furthermore, among the guide pieces 612 arranged in two stages on the outer circumferential side and the inner circumferential side with the central axis Ax as the center, the inclination angle θ is set so that the inclination angle θ increases toward the downstream side for the outer circumferential side guide piece 612 as well. The guide surface 612a may be further away from the central axis Ax. In the case shown in FIG. 7C , the combustion air is guided away from the central axis Ax by the guide surface 612a. In the case shown in FIG. 7C , the guide piece 612 on the inner peripheral side is tilted to increase the pressure loss, and the flow rate of the combustion air flowing on the outer peripheral side of the combustion air nozzle 54 is not reduced. The flow rate of the combustion air of the flow device 618 may also be different. In addition, as long as the flow rate of the combustion air flowing on the outer peripheral side of the combustion air nozzle 54 is not reduced, the flow rate of the combustion air passing through the flow restrictor 618 does not need to be restricted. Therefore, in the case shown in FIG. 7C , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is such that the flow velocity is faster at a position farther from the central axis Ax than at a position closer to the central axis Ax. flow velocity distribution.

The third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C can be configured so that the inclination angle θ of the guide surface 612a can be changed even during operation of the boiler 10. For example, in the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the flow velocity distribution imparting part 60 is the same as the second ammonia burner 51B shown in FIGS. 6A, 6B, and 6C. A guide piece driving device 614 may be included, which is configured to change the inclination angle θ of the guide surface 612a. The guide piece driving device 614 may include a drive source (not shown) for changing the inclination angle θ of the guide surface 612a, and a drive source configured to transmit the driving force of the drive source to change the guide surface 612a. A communication device (not shown) for the tilt angle θ.

The third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C can be configured so that the opening degree of the flow restrictor 618 can be changed even during operation of the boiler 10. For example, in the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the flow velocity distribution portion 60 may also include a restrictor driving device 619 configured to change the opening of the restrictor 618. . The current limiter driving device 619 may include a driving source (not shown) for changing the opening of the current limiter 618, and may be configured to transmit the driving force of the driving source to change the opening of the current limiter 618. Transmission device not shown in the figure.

The third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C provides a flow velocity distribution to the combustion air blown out from the combustion air nozzle 54, thereby stabilizing the ignition position and suppressing _NOx. of production.

In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the first flow velocity distribution imparting part 61 (the guide piece 612 and the flow restrictor 618) arranged inside the combustion air nozzle 54 ), it is relatively easy to provide flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54 .

In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the guide piece 612 is used to guide the combustion air and suppress the flow rate of the combustion air passing through the flow restrictor 618, thereby When viewed along the central axis Ax of the combustion air nozzle 54, the flow velocity of the combustion air can be made different between the central area and the outer area of the combustion air nozzle 54. Thereby, flow velocity distribution can be provided to the combustion air sprayed from the combustion air nozzle 54 .

In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is affected by the above-mentioned inclination angle θ and the opening of the flow restrictor 618. influence. Therefore, the guide plate driving device 614 is used to change the inclination angle θ, and the restrictor driving device 619 is used to change the opening of the flow restrictor 618, thereby changing the flow rate of the combustion air sprayed from the combustion air nozzle 54. distributed. Thereby, even if the flow rate of the combustion air changes, for example, by changing the inclination angle θ, the ignition position can be stabilized and the generation of _NOx can be suppressed.

In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the guide surface 612a is fixed at an angle where the above-mentioned inclination angle θ is set in advance, and the above-mentioned inclination angle θ cannot be changed during the operation of the boiler 10. The tilt angle θ is also acceptable. In the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the opening of the flow limiter 618 is fixed to a predetermined opening, and the limit cannot be changed during the operation of the boiler 10. The opening of the flow device 618 can also be adjusted.

(About the fourth ammonia burner 51D) The fourth ammonia burner 51D shown in FIGS. 8A, 8B, and 8C is a diffusion type burner similar to the first ammonia burner 51A shown in FIG. 3, and is equipped with: The ammonia injection nozzle 52 , the combustion air nozzle 54 for injecting combustion air from the outside of the ammonia injection nozzle 52 , the flame retainer 56 , and the flow velocity distribution providing part 60 . The fourth ammonia burner 51D shown in FIGS. 8A, 8B, and 8C is the same as the first ammonia burner 51A shown in FIG. 3 , and the flame retainer 56 is, for example, a diffusion-type flame retainer 56A.

In the fourth ammonia burner 51D shown in FIGS. 8A, 8B, and 8C, the combustion air nozzle 54 has the same structure as the first ammonia burner 51A shown in FIG. 3 .

The fourth ammonia burner 51D shown in FIGS. 8A, 8B, and 8C is the same as the first ammonia burner 51A shown in FIG. 3. The ammonia injection nozzle 52 is coaxially arranged with the combustion air nozzle 54. , is configured to inject ammonia into the furnace 11 from a plurality of injection holes 52h. In addition, the fourth ammonia burner 51D shown in FIGS. 8A, 8B, and 8C is the same as the first ammonia burner 51A shown in FIG. 3. The ammonia injection nozzle 52 has a nozzle pipe on the upstream side. 8A, 8B, and 8C may extend inward in the drawing or in the up-down direction in the drawing, or they may not be configured in this way.

The fourth ammonia burner 51D shown in FIGS. 8A, 8B, and 8C is the same as the first ammonia burner 51A shown in FIG. 3. The combustion air supplied to the combustion air nozzle 54 is from The air is injected into the furnace 11 through the gap between the opening 54a of the outlet of the combustion air nozzle 54 and the outer peripheral end of the diffusion type flame holder 56A.

In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , like the first ammonia burner 51A shown in FIG. 3 , the flow velocity distribution imparting part 60 is configured to provide a response to the air ejected from the combustion air nozzle 54 . The combustion air imparts a flow rate distribution. More specifically, the fourth ammonia burner 51D shown in FIGS. 8B and 8C is the same as the first ammonia burner 51A shown in FIG. 3 , and the flow velocity distribution imparting part 60 is the first flow velocity distribution imparting part. 61, which is arranged inside the combustion air nozzle 54 and provides a flow velocity distribution to the combustion air flowing inside the combustion air nozzle 54. In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , the first flow velocity distribution portion 61 includes a guide piece 612 that is inclined at a predetermined inclination angle θ with respect to the extending direction of the central axis Ax. Guide surface 612a.

In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , the guide piece 612 is arranged, for example, near the opening 54 a of the outlet of the combustion air nozzle 54 . In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , the guide piece 612 is arranged, for example, in a region near the outlet of the combustion air nozzle 54 , that is, while maintaining a rectangular cross-sectional shape, the guide piece 612 follows the At least a part of the region in which the cross-sectional area of the flow path becomes smaller toward the downstream side overlaps with the extending direction of the central axis Ax. Furthermore, in the fourth ammonia burner 51D shown in FIGS. 8B and 8C , the guide piece 612 may be disposed in an area on the upstream side of this area.

In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , the guide piece 612 does not include a movable part that can be used to change the inclination angle θ, and is fixed to the combustion air at a preset inclination angle θ, for example. Nozzle 54.

In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , at least one guide piece 612 may be disposed along each side of the combustion air nozzle 54 having a rectangular cross-section. For example, in the examples shown in FIGS. 8B and 8C , a guide piece 612 is disposed on each side of the combustion air nozzle 54 having a rectangular cross-section on the two sides separated in the vertical direction in the figure. A guide piece 612 is respectively arranged on the two sides (not shown) that are separated toward the inner side of the figure. In addition, as in the third ammonia burner 51C shown in FIGS. 7A, 7B, and 7C, the guide piece 612 is arranged along each side of the combustion air nozzle 54 having a rectangular cross section, and is connected to each side of the combustion air nozzle 54. A plurality of segments may be arranged in a direction orthogonal to the central axis Ax. Furthermore, the guide pieces 612 may be respectively arranged on two sides separated in the up-down direction as shown in the figure, and may not be arranged respectively on two sides (not shown) separated in the inward direction as shown in the figure. Furthermore, the guide pieces 612 may be arranged on two sides (not shown) that are separated in the inward direction of the figure, instead of being arranged on two sides separated in the up-down direction as shown in the figure.

In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , the flow velocity distribution of the combustion air blown from the combustion air nozzle 54 is changed by the inclination angle θ of the guide surface 612 a. In addition, in FIGS. 8A, 8B, and 8C, the arrows described on the downstream side than the outlet of the combustion air nozzle 54 indicate the tendency of the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54, that is, The relationship between the distance from the central axis Ax and the flow rate of the combustion air.

(When the guide piece 612 is not configured) FIG. 8A shows a case where the guide piece 612 is not arranged in the fourth ammonia burner 51D. In the case shown in FIG. 8A , there is no guide piece 612 , so the combustion air flowing through the combustion air nozzle 54 is not guided close to the central axis Ax by the guide piece 612 , nor is it guided to the central axis Ax. away from the central axis Ax. Thereby, in the case shown in FIG. 8A , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 becomes a relatively equal flow velocity regardless of the position of the central axis Ax.

(When the guide surface 612a approaches the central axis Ax toward the downstream side) FIG. 8B shows a case where the inclination angle θ is set so that the guide surface 612a approaches the central axis Ax as it goes toward the downstream side. In the case shown in FIG. 8B , the combustion air is guided toward the central axis Ax by the guide surface 612a. Therefore, in the case shown in FIG. 8B , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is such that the flow velocity is faster at a position closer to the central axis Ax than at a position farther from the central axis Ax. flow velocity distribution.

(When the guide surface 612a is moved away from the central axis Ax toward the downstream side) FIG. 8C shows a case where the inclination angle θ is set so that the guide surface 612a moves away from the central axis Ax as it goes toward the downstream side. In the case shown in FIG. 8C , the combustion air is guided away from the central axis Ax by the guide surface 612a. Therefore, in the case shown in FIG. 8C , the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is such that the flow velocity is faster at a position farther from the central axis Ax than at a position closer to the central axis Ax. flow velocity distribution.

The fourth ammonia burner 51D shown in FIGS. 8A, 8B, and 8C provides a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54, thereby stabilizing the ignition position and suppressing _NOx. of production.

In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , the first flow velocity distribution imparting part 61 (guide plate 612 ) arranged inside the combustion air nozzle 54 makes it easier to adjust the flow rate from the combustion air nozzle 54 to the fourth ammonia burner 51D. The combustion air sprayed from the air nozzle 54 is provided with a flow velocity distribution.

In the fourth ammonia burner 51D shown in FIGS. 8B and 8C , the guide piece 612 is used to guide the combustion air. When viewed along the central axis Ax of the combustion air nozzle 54, it can The flow velocity of the combustion air is made different between the central area and the outer area of the combustion air nozzle 54 . Thereby, flow velocity distribution can be provided to the combustion air sprayed from the combustion air nozzle 54 .

The fourth ammonia burner 51D shown in FIGS. 8B and 8C does not include a movable part capable of changing the inclination angle θ, and has a simple structure.

(About the fifth ammonia burner 51E) The fifth ammonia burner 51E shown in Fig. 9 is the same as the first ammonia burner 51A shown in Fig. 3. It is a diffusion type burner and includes: an ammonia injection nozzle 52 for injecting ammonia; The combustion air nozzle 54 which injects combustion air from the outside of the ammonia injection nozzle 52, the flame retainer 56, and the flow velocity distribution providing part 60. In the fifth ammonia burner 51E shown in FIG. 9 , like the first ammonia burner 51A shown in FIG. 3 , the flame retainer 56 is, for example, a diffusion-type flame retainer 56A.

In the fifth ammonia burner 51E shown in FIG. 9 , the combustion air nozzle 54 has a rectangular shape when viewed along the central axis Ax, similar to the first ammonia burner 51A shown in FIG. 3 . The channel with a cross-section is formed such that the flow path cross-sectional area becomes smaller toward the downstream side while maintaining a rectangular cross-sectional shape near the end portion on the downstream side.

The fifth ammonia burner 51E shown in Fig. 9 is the same as the first ammonia burner 51A shown in Fig. 3. The ammonia injection nozzle 52 is coaxially arranged with the combustion air nozzle 54, and is configured to inject from a plurality of Hole 52h injects ammonia into furnace 11. In addition, in the fifth ammonia burner 51E shown in FIG. 9 , similar to the first ammonia burner 51A shown in FIG. 3 , the ammonia injection nozzle 52 has the nozzle pipe on the upstream side inward of the drawing in FIG. 9 The direction may be extended in the up and down direction of the drawing, or it may not be constructed in this way.

In the fifth ammonia burner 51E shown in FIG. 9 , as will be described later, the combustion air supplied to the combustion air nozzle 54 is supplied from the opening 54 a of the outlet of the combustion air nozzle 54 and the diffusion type flame retainer. 56A is injected into the furnace 11 between the outer peripheral ends.

In the fifth ammonia burner 51E shown in FIG. 9 , the flow velocity distribution providing part 60 is configured to provide a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54 . Specifically, in the fifth ammonia burner 51E shown in FIG. 9 , the flow velocity distribution providing part 60 is the second flow velocity distribution providing part 62 . The second flow velocity distribution imparting part 62 has a partition wall 625 that separates a first flow path 541 through which combustion air can flow inside the combustion air nozzle 54 and a second flow path through which combustion air can flow outside the first flow path 541 . 2 flow paths 542 are separated. That is, in the fifth ammonia burner 51E shown in FIG. 9 , the combustion air nozzle 54 becomes the first flow path 541 and is formed to surround the outside of the first flow path 541 when viewed along the central axis Ax. The dual structure of the second flow path 542. In addition, the first flow path 541 and the second flow path 542 are formed to surround the ammonia injection nozzle 52 in the circumferential direction on the outside in the radial direction in FIG. 9 , but they may also be formed in a layered shape in the up and down direction as shown in the figure. The direction may be layered.

In the fifth ammonia burner 51E shown in FIG. 9 , the second flow velocity distribution providing part 62 has a first flow rate adjusting device 621 that adjusts the flow rate of the combustion air supplied to the first flow path 541 . The second flow velocity distribution providing unit 62 has a second flow rate adjusting device 622 that adjusts the flow rate of the combustion air supplied to the second flow path 542 . The first flow rate regulating device 621 is, for example, a flow rate regulating means (eg, a flow restrictor) provided at the connection portion between the air duct 24 and the first flow path 541 . In addition, when it is not necessary to change the combustion air flow rate supplied to the first flow path 541 during the operation of the boiler 10, the first flow rate regulating device 621 is provided between the air duct 24 and the first flow path 541, for example. Flow restriction means (such as flow restriction holes) at the connection part are also acceptable. Similarly, the second flow rate adjusting device 622 is, for example, a flow rate adjusting means (eg, a flow restrictor) provided at the connection portion between the air duct 24 and the second flow path 542 . In addition, when it is not necessary to change the combustion air flow rate supplied to the second flow path 542 during the operation of the boiler 10, the second flow rate regulating device 622 is provided between the air duct 24 and the second flow path 542, for example. Flow restriction means (such as flow restriction holes) at the connection part are also acceptable.

In the following description, the combustion air flow rate flowing through the first flow path 541 will be referred to as the first flow rate Q1, and the combustion air flow rate flowing through the second flow path 542 will be referred to as the second flow rate Q2. In the fifth ammonia burner 51E shown in FIG. 9 , the combustion air flow rate (first flow rate Q1 ) supplied to the first flow path 541 is adjusted by the first flow rate adjusting device 621 , and the supply is adjusted by the second flow rate adjusting device 622 The combustion air flow rate (second flow rate Q2) to the second flow path 542 makes it easier to provide a flow velocity distribution to the combustion air blown out from the combustion air nozzle 54 . That is, in the fifth ammonia burner 51E shown in FIG. 9 , the first flow rate Q1, the second flow rate Q2, and the ratio of the first flow rate Q1 to the second flow rate Q2 can be appropriately adjusted to change the flow rate from the combustion air nozzle. The flow velocity distribution of the combustion air blown out from the opening 54a at the downstream end of 54.

That is, in the fifth ammonia burner 51E shown in FIG. 9 , the flow rate distribution of the combustion air sprayed from the combustion air nozzle 54 can be easily changed by increasing the number of combustion air flow paths. . Furthermore, by adjusting the flow rate of the combustion air flowing through each flow path (the first flow path 541 and the second flow path 542 ), the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 can be changed in detail. This makes it easy to control the ignition position and the amount of _NOx generated.

In the fifth ammonia burner 51E shown in FIG. 9 , for example, the same amount of combustion air is injected equally into the furnace 11 from the first flow path 541 and the second flow path 542 , and the situation is as follows: When either the flow path 541 or the second flow path 542 is injected into the furnace 11, the flow rate of the fuel air injected into the furnace 11 is faster than the former. Therefore, the mixing position of the combustion air and ammonia is such that the latter is further away from the fifth ammonia burner 51E than the former.

Furthermore, in the fifth ammonia burner 51E shown in FIG. 9 , for example, the same amount of combustion air is injected into the furnace 11 only from the first flow path 541, and the same amount is injected only from the second flow path 542. As for the situation inside the furnace 11, the entrapment of combustion air (generation of circulating flow) due to the flame retainer 56A is smaller in the latter than in the former. Therefore, it is considered that the velocity component in the linear direction of the combustion air injected into the furnace 11 is larger in the latter than in the former, and the mixing position of the combustion air and ammonia is further away from the fifth ammonia burner 51E in the latter than in the former.

The fifth ammonia burner 51E shown in FIG. 9 provides a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54, thereby stabilizing the ignition position and suppressing the generation of _NOx . Specifically, for example, it is as follows. The ratio of the first flow rate Q1 to the second flow rate Q2 in which the flow rate distribution of the combustion air sprayed from the combustion air nozzle 54 becomes relatively equal regardless of the position of the central axis Ax is defined as Ra1. For example, if the proportion of the first flow rate Q1 is increased compared with the ratio Ra1, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 will be such that the flow velocity is closer to the central axis Ax than farther from the central axis Ax. The location also has fast flow velocity distribution. In the case of such a flow velocity distribution, by increasing the flow velocity of the combustion air around the flame retaining device 56, a flame retaining area (circulation area) can be fully formed, thereby improving ignition properties. Furthermore, for example, if the specific gravity of the second flow rate Q2 is increased compared to the above-mentioned ratio Ra1, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is such that the flow velocity is higher at a position farther from the central axis Ax than at a position farther from the central axis Ax. The flow velocity distribution is faster at closer locations. In the case of such a flow velocity distribution, it is easy to supply combustion air to a position relatively far from the ignition point, so it is difficult to form a local area with relatively high air, and it is expected that the amount of _NOx generated can be suppressed.

(About the sixth ammonia burner 51F) The sixth ammonia burner 51F shown in Fig. 10 has the same structure as the fifth ammonia burner 51E shown in Fig. 9 except for the structure of the flame retainer 56. That is, the sixth ammonia burner 51F shown in FIG. 10 is a diffusion type burner similar to the first ammonia burner 51A shown in FIG. 3 and is provided with an ammonia injection nozzle 52 for injecting ammonia. , a combustion air nozzle 54 for injecting combustion air from the outside of the ammonia injection nozzle 52 , a flame retainer 56 , and a flow velocity distribution providing part 60 . The sixth ammonia burner 51F shown in FIG. 10 is different from the first ammonia burner 51A shown in FIG. 3 in that the flame retainer 56 is, for example, a swirl type flame retainer 56B.

In the sixth ammonia burner 51F shown in Fig. 10, the combustion air nozzle 54, like the first ammonia burner 51A shown in Fig. 3, has a rectangular shape when viewed along the central axis Ax, and has a rectangular shape. The channel with a cross-section is formed such that the flow path cross-sectional area becomes smaller toward the downstream side while maintaining a rectangular cross-sectional shape near the end portion on the downstream side.

The sixth ammonia burner 51F shown in Fig. 10 is the same as the first ammonia burner 51A shown in Fig. 3. The ammonia injection nozzle 52 is coaxially arranged with the combustion air nozzle 54, and is configured to inject from a plurality of Hole 52h injects ammonia into furnace 11. In addition, in the sixth ammonia burner 51F shown in Fig. 10, similar to the first ammonia burner 51A shown in Fig. 3, the ammonia injection nozzle 52 has the nozzle pipe on the upstream side inward of the drawing in Fig. 9 The direction may be extended in the up and down direction of the drawing, or it may not be constructed in this way.

In the sixth ammonia burner 51F shown in FIG. 10 , the combustion air supplied to the combustion air nozzle 54 is supplied from the opening 54 a of the outlet of the combustion air nozzle 54 and the outer periphery of the swirl type flame retainer 56B. Between the ends and from the swirl type flame retainer 56B, it is sprayed into the furnace 11 .

In the sixth ammonia burner 51F shown in FIG. 10 , the flow velocity distribution imparting unit 60 is configured to impart a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54 . More specifically, in the sixth ammonia burner 51F shown in FIG. 10 , the flow velocity distribution portion 60 is the second flow velocity distribution portion 62 . The second flow velocity distribution imparting part 62 has a partition wall 625 that separates a first flow path 541 through which combustion air can flow inside the combustion air nozzle 54 and a second flow path through which combustion air can flow outside the first flow path 541 . 2 flow paths 542 are separated. That is, in the sixth ammonia burner 51F shown in FIG. 10 , the combustion air nozzle 54 becomes the first flow path 541 and is formed to surround the outside of the first flow path 541 when viewed along the central axis Ax. The dual structure of the second flow path 542. In addition, the first flow path 541 and the second flow path 542 are formed to surround the ammonia injection nozzle 52 in the circumferential direction on the outside in the radial direction in FIG. 10 , but they may also be formed in a layered shape in the up and down direction as shown in the figure. The direction may be layered.

In the sixth ammonia burner 51F shown in FIG. 10 , the second flow velocity distribution portion 62 has a first flow rate adjusting device 621 that adjusts the flow rate of the combustion air supplied to the first flow path 541 . The second flow velocity distribution providing unit 62 has a second flow rate adjusting device 622 that adjusts the flow rate of the combustion air supplied to the second flow path 542 . In the sixth ammonia burner 51F shown in FIG. 10 , the first flow rate adjusting device 621 and the second flow rate adjusting device 622 are the same as the first flow rate adjusting device 621 and the second flow rate adjusting device 622 in the fifth ammonia burner 51E shown in FIG. 9 The second flow rate regulating device 622 is the same.

In the sixth ammonia burner 51F shown in FIG. 10 , the combustion air flow rate (first flow rate Q1 ) supplied to the first flow path 541 is adjusted by the first flow rate adjusting device 621 , and the supply is adjusted by the second flow rate adjusting device 622 The combustion air flow rate (second flow rate Q2) to the second flow path 542 makes it easier to provide a flow velocity distribution to the combustion air blown out from the combustion air nozzle 54 . That is, in the sixth ammonia burner 51F shown in FIG. 10 , the first flow rate Q1, the second flow rate Q2, and the ratio of the first flow rate Q1 to the second flow rate Q2 can be appropriately adjusted to change the flow rate from the combustion air nozzle. 54Flow velocity distribution of combustion air ejected.

In the sixth ammonia burner 51F shown in FIG. 10 , the number of combustion air flow paths in the combustion air nozzle 54 is increased, thereby making it easier to change the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 . Furthermore, by adjusting the flow rate of the combustion air flowing through each flow path (the first flow path 541 and the second flow path 542 ), the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 can be changed in detail. In addition, in the sixth ammonia burner 51F shown in Fig. 10, the combustion air flow rate flowing in each flow path (the first flow path 541 and the second flow path 542) is adjusted, thereby making it possible to adjust the swirl type in detail. The rotational force of the combustion air generated by the flame holder 56B. This makes it easy to control the ignition position and the amount of _NOx generated.

In the sixth ammonia burner 51F shown in FIG. 10 , for example, the same amount of combustion air is injected equally into the furnace 11 from the first flow path 541 and the second flow path 542 , and the situation is as follows: When either the flow path 541 or the second flow path 542 is injected into the furnace 11, the flow rate of the fuel air injected into the furnace 11 is faster than the former. Therefore, the mixing position of the combustion air and ammonia is such that the latter is further away from the sixth ammonia burner 51F than the former. By arranging the mixing position of combustion air and ammonia away from the sixth ammonia burner 51F as described above, it is difficult to locally form a relatively high air area, and it is expected that the amount of _NOx generated can be suppressed.

Furthermore, in the sixth ammonia burner 51F shown in FIG. 10 , for example, the same amount of combustion air is injected into the furnace 11 only from the first flow path 541, and the same amount is injected only from the second flow path 542. As for the situation inside the furnace 11, the entrainment (generation of swirling flow) of combustion air due to the flame retainer 56B is smaller in the latter than in the former. Therefore, the velocity component in the linear direction of the combustion air injected into the furnace 11 is larger in the latter than in the former, and the mixing position of the combustion air and ammonia is further away from the sixth ammonia burner 51F in the latter than in the former. By arranging the mixing position of combustion air and ammonia away from the sixth ammonia burner 51F as described above, it is difficult to locally form a relatively high air area, and it is expected that the amount of _NOx generated can be suppressed.

(About the seventh ammonia burner 51G) The seventh ammonia burner 51G shown in Fig. 11 is not a diffusion type burner like the fifth ammonia burner 51E shown in Fig. 9 and the sixth ammonia burner 51F shown in Fig. 10, but It is a partially premixed joint (flat) type burner. The seventh ammonia burner 51G shown in FIG. 11 is provided with an ammonia injection nozzle 52 for injecting ammonia, a combustion air nozzle 54 for injecting combustion air from the outside of the ammonia injection nozzle 52, and a flow velocity distribution providing part 60. . In the seventh ammonia burner 51G shown in FIG. 11, the ammonia injection nozzle 52 is a partial premixing type joint nozzle 52A.

In the seventh ammonia burner 51G shown in Fig. 11, the combustion air nozzle 54, like the first ammonia burner 51A shown in Fig. 3, has a rectangular shape when viewed along the central axis Ax, and has a rectangular shape. The channel with a cross-section is formed such that the flow path cross-sectional area becomes smaller toward the downstream side while maintaining a rectangular cross-sectional shape near the end portion on the downstream side.

In the seventh ammonia burner 51G shown in FIG. 11, the joint nozzle 52A has a plurality of injection holes 52h for injecting ammonia. In the joint nozzle 52A, the plurality of injection holes 52h are arranged at intervals in one direction, for example. In the seventh ammonia burner 51G shown in FIG. 11 , the cylindrical portion 58 is arranged on the downstream side of the joint nozzle 52A, and is arranged to surround the joint nozzle 52A with a gap from the outside.

In the seventh ammonia burner 51G shown in FIG. 11 , as will be described later, the combustion air supplied to the combustion air nozzle 54 is injected into the furnace 11 from the opening 54 a at the outlet of the combustion air nozzle 54 .

In the seventh ammonia burner 51G shown in FIG. 11 , ammonia is injected into the inside of the cylinder portion 58 from the plurality of injection holes 52h of the joint nozzle 52A, and is burned with the gas flowing in from the gap between the joint nozzle 52A and the cylinder portion 58 . It is injected into the furnace 11 while premixing with air. In addition, in the seventh ammonia burner 51G shown in FIG. 11 , the combustion air flowing into the inside of the cylinder 58 from the gap between the joint nozzle 52A and the cylinder 58 flows through the first flow path 541 described below. part of the air used for combustion. That is, partial premixed combustion is performed in the seventh ammonia burner 51G.

In the seventh ammonia burner 51G shown in FIG. 11 , the flow velocity distribution providing part 60 is configured to provide a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54 . More specifically, in the seventh ammonia burner 51G shown in FIG. 11 , the flow velocity distribution providing part 60 is the second flow velocity distribution providing part 62 . The second flow velocity distribution imparting part 62 has a partition wall 625 that separates a first flow path 541 through which combustion air can flow inside the combustion air nozzle 54 and a second flow path through which combustion air can flow outside the first flow path 541 . 2 flow paths 542 are separated. That is, in the seventh ammonia burner 51G shown in FIG. 11 , the combustion air nozzle 54 becomes the first flow path 541 and is formed to surround the outside of the first flow path 541 when viewed along the central axis Ax. The dual structure of the second flow path 542. In addition, the first flow path 541 and the second flow path 542 are formed to surround the ammonia injection nozzle 52 in the circumferential direction on the outside in the radial direction in FIG. 11 , but they may also be formed in a layered shape in the up and down direction as shown in the figure. The direction may be layered.

In the seventh ammonia burner 51G shown in FIG. 11 , the second flow velocity distribution providing part 62 has a first flow rate adjusting device 621 that adjusts the flow rate of the combustion air supplied to the first flow path 541 . The second flow velocity distribution providing unit 62 has a second flow rate adjusting device 622 that adjusts the flow rate of the combustion air supplied to the second flow path 542 . In the seventh ammonia burner 51G shown in FIG. 11 , the first flow rate adjusting device 621 and the second flow rate adjusting device 622 are the same as the first flow rate adjusting device 621 and the second flow rate adjusting device 622 in the fifth ammonia burner 51E shown in FIG. 9 The second flow rate regulating device 622 is the same.

In the seventh ammonia burner 51G shown in FIG. 11 , the combustion air flow rate (first flow rate Q1 ) supplied to the first flow path 541 is adjusted by the first flow rate adjusting device 621 , and the supply is adjusted by the second flow rate adjusting device 622 The combustion air flow rate (second flow rate Q2) to the second flow path 542 makes it easier to provide a flow velocity distribution to the combustion air blown out from the combustion air nozzle 54 . That is, in the seventh ammonia burner 51G shown in FIG. 11, the first flow rate Q1, the second flow rate Q2, and the ratio of the first flow rate Q1 to the second flow rate Q2 can be appropriately adjusted to change the flow rate from the combustion air nozzle. 54Flow velocity distribution of combustion air ejected.

In the seventh ammonia burner 51G shown in FIG. 11 , the number of combustion air flow paths in the combustion air nozzle 54 is increased, thereby making it easier to change the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 . Furthermore, by adjusting the flow rate of the combustion air flowing through each flow path (the first flow path 541 and the second flow path 542 ), the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 can be changed in detail.

The seventh ammonia burner 51G shown in FIG. 11 can adjust the flow rate of the combustion air flowing in the first flow path 541, so it can also help to adjust the flow rate of the combustion air premixed with the ammonia inside the cylinder portion 58. Adjust.

(About the 8th ammonia burner 51H) The eighth ammonia burner 51H shown in FIG. 12 corresponds to an embodiment in which the number of combustion air flow paths in the combustion air nozzle 54 of the fifth ammonia burner 51E shown in FIG. 9 is further increased. That is, the eighth ammonia burner 51H shown in FIG. 12 is a diffusion type burner similar to the first ammonia burner 51A shown in FIG. 3 and includes an ammonia injection nozzle 52 for injecting ammonia. , a combustion air nozzle 54 for injecting combustion air from the outside of the ammonia injection nozzle 52 , a flame retainer 56 , and a flow velocity distribution providing part 60 . In the eighth ammonia burner 51H shown in FIG. 12 , the flame retainer 56 is, for example, a diffusion-type flame retainer 56A, similar to the first ammonia burner 51A shown in FIG. 3 .

In the eighth ammonia burner 51H shown in Fig. 12, the combustion air nozzle 54, like the first ammonia burner 51A shown in Fig. 3, has a rectangular shape when viewed along the central axis Ax, and has a rectangular shape. The channel with a cross-section is formed such that the flow path cross-sectional area becomes smaller toward the downstream side while maintaining a rectangular cross-sectional shape near the end portion on the downstream side.

The eighth ammonia burner 51H shown in Fig. 12 is the same as the first ammonia burner 51A shown in Fig. 3. The ammonia injection nozzle 52 is coaxially arranged with the combustion air nozzle 54, and is configured to inject from a plurality of Hole 52h injects ammonia into furnace 11. In addition, in the eighth ammonia burner 51H shown in Fig. 12, similar to the first ammonia burner 51A shown in Fig. 3, the ammonia injection nozzle 52 has the nozzle pipe on the upstream side inward of the drawing in Fig. 12 The direction may be extended in the up and down direction of the drawing, or it may not be constructed in this way.

In the eighth ammonia burner 51H shown in FIG. 12, as will be described later, the combustion air supplied to the combustion air nozzle 54 is supplied from the opening 54a of the outlet of the combustion air nozzle 54 and the diffusion type flame retainer. 56A is injected into the furnace 11 between the outer peripheral ends.

In the eighth ammonia burner 51H shown in FIG. 12 , the flow velocity distribution imparting unit 60 is configured to impart a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54 . More specifically, in the eighth ammonia burner 51H shown in FIG. 12 , the flow velocity distribution portion 60 is the second flow velocity distribution portion 62 . The second flow velocity distribution imparting part 62 has a partition wall 625 and a partition wall 626. The partition wall 625 provides a first flow path 541 for circulating combustion air inside the combustion air nozzle 54 and a partition wall 626 that allows the first flow path 541 to flow outside the first flow path 541. The second flow path 542 through which combustion air flows is divided, and the partition wall 626 separates a third flow path 543 through which combustion air can flow outside the second flow path 542 . That is, in the eighth ammonia burner 51H shown in FIG. 12 , the combustion air nozzle 54 becomes the first flow path 541 and is formed to surround the outside of the first flow path 541 when viewed along the central axis Ax. The second flow path 542 and the third flow path 543 surrounding the outer side of the second flow path 542 are formed into a triple structure. In addition, the first flow path 541, the second flow path 542, and the third flow path 543 are formed to surround the ammonia injection nozzle 52 in the circumferential direction on the radial outer side in FIG. 12, but they may also be formed in a layered shape in the vertical direction as shown in the figure. Yes, it can be formed into a layered shape toward the inside as shown in the figure.

In the eighth ammonia burner 51H shown in FIG. 12 , the second flow velocity distribution providing part 62 has a first flow rate adjusting device 621 that adjusts the flow rate of the combustion air supplied to the first flow path 541 . The second flow velocity distribution providing unit 62 has a second flow rate adjusting device 622 that adjusts the flow rate of the combustion air supplied to the second flow path 542 . The second flow velocity distribution providing unit 62 has a third flow rate adjusting device 623 that adjusts the flow rate of the combustion air supplied to the third flow path 543 . In the eighth ammonia burner 51H shown in FIG. 12 , the first flow rate adjusting device 621 and the second flow rate adjusting device 622 are the same as the first flow rate adjusting device 621 and the second flow rate adjusting device 622 in the fifth ammonia burner 51E shown in FIG. 9 The second flow rate regulating device 622 is the same. In the eighth ammonia burner 51H shown in FIG. 12 , the third flow rate adjustment device 623 is, for example, a flow rate adjustment (for example, a flow limiter) provided at the connection portion between the air duct 24 and the third flow path 543 . In addition, when it is not necessary to change the combustion air flow rate supplied to the third flow path 543 during the operation of the boiler 10, the third flow rate regulating device 623 is provided between the air duct 24 and the third flow path 543, for example. Flow restriction means (such as flow restriction holes) at the connection part are also acceptable.

In the following description, the combustion air flow rate flowing in the third flow path 543 will be referred to as the third flow rate Q3. In the eighth ammonia burner 51H shown in Figure 12, the first flow rate adjustment device 621 is used to adjust the first flow rate Q1, the second flow rate adjustment device 622 is used to adjust the second flow rate Q2, and the third flow rate adjustment device 623 is used to adjust the third flow rate Q1. The flow rate Q3 makes it relatively easy to provide a flow velocity distribution to the combustion air blown out from the combustion air nozzle 54 . That is, in the eighth ammonia burner 51H shown in FIG. 12, the first flow rate Q1, the second flow rate Q2, the third flow rate Q3, the ratio of the first flow rate Q1, the second flow rate Q2, and the third flow rate Q3 are appropriately adjusted. , thereby changing the flow velocity distribution of the combustion air sprayed from the opening 54a at the downstream end of the combustion air nozzle 54.

That is, in the eighth ammonia burner 51H shown in FIG. 12 , the number of combustion air flow paths in the combustion air nozzle 54 is further increased, thereby making it easier to change the flow rate of the combustion air sprayed from the combustion air nozzle 54 distributed. Furthermore, by adjusting the flow rate of the combustion air flowing in each flow path (the first flow path 541, the second flow path 542, and the third flow path 543), the combustion air sprayed from the combustion air nozzle 54 can be changed in detail. flow velocity distribution. This makes it easy to control the ignition position and the amount of _NOx generated.

Furthermore, in the eighth ammonia burner 51H shown in FIG. 12 , the combustion air nozzle 54 is further provided with a flow path formed to surround the outside of the third flow path 543 when viewed along the central axis Ax, thereby forming A multiple structure of four or more layers may be configured so that the flow rate of the combustion air flowing through each flow path can be adjusted.

The present invention is not limited to the above-described embodiments, but also includes modifications of the above-described embodiments and modifications of these embodiments, as well as modifications of these embodiments. For example, the above-described first ammonia burner 51A, second ammonia burner 51B, third ammonia burner 51C, fourth ammonia burner 51D, fifth ammonia burner 51E, and eighth ammonia burner 51H is a diffusion type burner with a diffusion type flame retainer 56A, but it can also be a diffusion type burner with a swirl type flame retainer 56B like the sixth ammonia burner 51F. It may also be a partially premixed joint type burner like the seventh ammonia burner 51G. That is, in the above-mentioned embodiments, the ammonia burner 51 may be any of a partially premixed joint type, a diffusion type and a swirl type with a different flame retainer structure, or a diffusion type. . Thereby, in the ammonia burner 51 of the various burner types mentioned above, it is relatively easy to provide flow velocity distribution to the combustion air blown out from the combustion air nozzle 54 .

For example, in the sixth ammonia burner 51F shown in Fig. 10 and the seventh ammonia burner 51G shown in Fig. 11, the combustion air nozzle 54 becomes the first flow when viewed along the central axis Ax. The passage 541 has a dual structure formed to surround the outer side of the first passage 541 and the second passage 542 . However, in the sixth ammonia burner 51F shown in Fig. 10 and the seventh ammonia burner 51G shown in Fig. 11, the combustion air nozzle 54 is the same as the eighth ammonia burner 51H shown in Fig. 12 Similarly, it may be a multiple structure of three or more layers, and the flow rate of the combustion air flowing in each flow path may be adjusted.

The contents described in each of the above embodiments can be understood as follows, for example. (1) The ammonia combustion burner (ammonia burner 51) according to at least one embodiment of the present invention is an ammonia combustion burner for burning ammonia fuel in the boiler 10. An ammonia combustion burner (ammonia burner 51) according to at least one embodiment of the present invention is provided with: an ammonia injection nozzle 52 for injecting ammonia fuel; and a combustion air nozzle 54 for ejecting ammonia fuel from the ammonia injection nozzle 52. The combustion air is injected from the outside; and the flow velocity distribution providing part 60 provides a flow velocity distribution to the combustion air sprayed from the combustion air nozzle.

The ignition position and the generation of _NOx are affected by the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 . Therefore, according to the structure of (1) above, flow velocity distribution is provided to the combustion air sprayed from the combustion air nozzle 54, thereby stabilizing the ignition position and suppressing the generation of _NOx .

(2) In some embodiments, in the structure of (1) above, the flow velocity distribution portion 60 may also include a first flow velocity distribution portion 61, which is arranged inside the combustion air nozzle 54. The combustion air flowing inside the nozzle 54 provides a flow velocity distribution.

According to the structure of (2) above, it is relatively easy to provide a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54 by the first flow velocity distribution providing part 61 disposed inside the combustion air nozzle 54 .

(3) In some embodiments, in the structure of (2) above, the first flow velocity distribution portion 61 may include a flow path restricting member 611 when viewed along the central axis Ax of the combustion air nozzle 54 It extends from the center of the combustion air nozzle 54 toward the outside. The flow path restricting member 611 may form a gap through which the combustion air can flow, and the inner peripheral surface 54i of the combustion air nozzle 54 .

According to the structure of the above (3), the combustion air is guided to the gap, so that the flow rate of the combustion air can be adjusted to the center axis Ax of the combustion air nozzle 54 when viewed along the center axis Ax of the combustion air nozzle 54 . The central area is different from the outer areas. Thereby, flow velocity distribution can be provided to the combustion air sprayed from the combustion air nozzle 54 .

(4) In some embodiments, in the structure of (3) above, the flow velocity distribution providing part 60 may include a moving device 613 configured to move the flow path restricting member 611 along the central axis Ax.

The flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is affected by the position of the flow path restricting member 611 in the extending direction of the central axis Ax. Therefore, according to the structure of (4) above, the flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 can be changed by changing the position of the flow path restricting member 611 in the extending direction of the central axis Ax. Thereby, even if the flow rate of the combustion air changes, for example, by changing the position of the flow path restricting member 611 in the extending direction of the central axis Ax, the ignition position can be stabilized and the generation of _NOx can be suppressed.

(5) In some embodiments, in the structure of (2) above, the first flow velocity distribution portion 61 may also include a guide piece 612 having a predetermined inclination angle θ with respect to the extending direction of the central axis Ax. Inclined guide surface 612a.

According to the structure of the above (5), the combustion air is guided by the guide piece 612, so that when viewed along the central axis Ax of the combustion air nozzle 54, the flow rate of the combustion air can be adjusted to the position of the combustion air. The central area of the nozzle 54 is different from the outer areas. Thereby, flow velocity distribution can be provided to the combustion air sprayed from the combustion air nozzle 54 .

(6) In some embodiments, in the structure of (5) above, the flow velocity distribution providing part 60 may include a guide piece driving device 614 configured to change the inclination angle θ.

The flow velocity distribution of the combustion air sprayed from the combustion air nozzle 54 is affected by the above-mentioned inclination angle θ. Therefore, according to the structure of (6) above, by changing the inclination angle θ, the flow velocity distribution of the combustion air blown from the combustion air nozzle 54 can be changed. Thereby, even if the flow rate of the combustion air changes, for example, by changing the inclination angle θ, the ignition position can be stabilized and the generation of _NOx can be suppressed.

(7) In some embodiments, in the structure of the above (5) or (6), the first flow velocity distribution providing part 61 may also include a flow restrictor 618, which is arranged inside the combustion air nozzle 54 at a position larger than the above-mentioned The guide piece 612 also regulates the flow rate of the combustion air passing through the inner area.

According to the structure of (7) above, the combustion air is guided by the guide piece 612 and the flow rate of the combustion air passing through the flow restrictor 618 is suppressed, so that when viewed along the central axis Ax of the combustion air nozzle 54 , the flow velocity of the combustion air can be made different between the central area and the outer area of the combustion air nozzle 54 . Thereby, flow velocity distribution can be provided to the combustion air sprayed from the combustion air nozzle 54 .

(8) In some embodiments, in the structure of (1) above, the flow velocity distribution providing part 60 may also include a second flow velocity distribution providing part 62. The second flow velocity distribution imparting part 62 has a partition wall 625 that separates a first flow path 541 through which combustion air can flow inside the combustion air nozzle 54 and a second flow path through which combustion air can flow outside the first flow path 541 . 2. The flow paths 542 may be separated. The second flow velocity distribution providing unit 62 may include a first flow rate adjusting device 621 that adjusts the flow rate of the combustion air supplied to the first flow path 541 . The second flow velocity distribution providing unit 62 may include a second flow rate adjusting device 622 that adjusts the flow rate of the combustion air supplied to the second flow path 542 .

According to the structure of (8) above, the combustion air flow rate (first flow rate Q1) supplied to the first flow path 541 is adjusted by the first flow rate adjusting device 621, and the supply to the second flow path 542 is adjusted by the second flow rate adjusting device 622. The combustion air flow rate (the second flow rate Q2) makes it easier to provide a flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54.

(9) In some embodiments, in the structure of (8) above, the ammonia combustion burner (ammonia burner 51) may be a joint type, swirl type, or diffusion type burner. .

According to the structure of the above (9), in the ammonia combustion burner (ammonia burner 51) of the various burner types described above, it is relatively easy to provide flow velocity distribution to the combustion air sprayed from the combustion air nozzle 54.

(10) In some embodiments, in one of the structures of (1) to (9) above, the ammonia combustion burner (ammonia burner 51) may be a dedicated ammonia combustion burner.

According to the structure of (10) above, in the ammonia-dedicated combustion burner, the ignition position is stabilized and the generation of NOx is suppressed.

(11) The boiler 10 according to at least one embodiment of the present invention is provided with a furnace 11 including a furnace wall 101, and an ammonia combustion burner (ammonia combustion burner) having any one of the structures (1) to (10) provided on the furnace wall 101. Burner 51).

According to the structure of (11) above, in the ammonia combustion burner (ammonia burner 51) of the boiler 10, the ignition position is stabilized and the generation of _NOx is suppressed.

(12) The boiler 10 according to at least one embodiment of the present invention is provided with a furnace 11 including a furnace wall 101, and an ammonia combustion burner (ammonia combustion burner) having any one of the structures (1) to (10) provided on the furnace wall 101. The burner 51) is another fuel burner (burner 21) that is provided at a different position from the ammonia combustion burner (ammonia burner 51) on the furnace wall 101 and burns fuel other than ammonia fuel.

According to the structure of (12) above, in the ammonia combustion burner (ammonia burner 51) of the boiler 10, the ignition position is stabilized and the generation of _NOx is suppressed.

(13) In several embodiments, in the structure of (12) above, the boiler 10 is equipped with an ammonia combustion burner (ammonia burner 51) and other fuel burners (burner 21). A convolution-fired boiler that performs convolution combustion within 11 hours can also be used.

According to the structure of (13) above, in the ammonia combustion burner (ammonia burner 51) of the spiral combustion boiler, the ignition position is stabilized and the generation of _NOx is suppressed.

1: Boiler system 10: Boiler 11:Stove 20,50: Combustion device 21:Burner 51: Ammonia burner (ammonia combustion burner) 51A: No. 1 ammonia burner 51B: The second ammonia burner 51C: The third ammonia burner 51D: No. 4 ammonia burner 51E: No. 5 ammonia burner 51F: No. 6 ammonia burner 51G: No. 7 ammonia burner 51H: No. 8 ammonia burner 52: Ammonia injection nozzle 52A: Connector nozzle 54:Combustion air nozzle 54i: Inner surface 56,56A,56B: Flame protector 60: Flow velocity distribution giving part 61: The first flow velocity distribution providing part 62: The second flow velocity distribution providing part 101: stove wall 541: 1st flow path 542: 2nd flow path 611: Flow path restriction member 612:Guide film 612a: Guide surface 613:Mobile device 614: Guide plate driving device 618: Current limiter 619: Current limiter drive device 621: The first flow regulating device 622: Second flow regulating device 625:Partition wall

[Fig. 1] Fig. 1 is a schematic structural diagram showing a boiler system including a boiler using ammonia fuel and a fuel other than ammonia fuel as a main fuel according to this embodiment. [Fig. 2] A schematic diagram illustrating the relationship between the flow rate and ignition position of the combustion air and the _NOx production amount of the ammonia-dedicated combustion burner. [Fig. 3] Schematic diagram of the first ammonia burner. [Fig. 4] A schematic diagram showing an example of a structure for driving the flow velocity distribution providing portion of the first ammonia burner shown in Fig. 3. [Fig. [Fig. 5A] A schematic diagram for explaining the function of the flow velocity distribution providing part of the first ammonia burner shown in Fig. 3. [Fig. [Fig. 5B] A schematic diagram for explaining the function of the flow velocity distribution providing part of the first ammonia burner shown in Fig. 3. [Fig. [Fig. 5C] A schematic diagram for explaining the function of the flow velocity distribution providing part of the first ammonia burner shown in Fig. 3. [Fig. [Fig. 6A] Schematic diagram of the second ammonia burner. [Fig. 6B] Schematic diagram of the second ammonia burner. [Fig. 6C] Schematic diagram of the second ammonia burner. [Fig. 7A] Schematic diagram of the third ammonia burner. [Fig. 7B] Schematic diagram of the third ammonia burner. [Fig. 7C] Schematic diagram of the third ammonia burner. [Fig. 8A] Schematic diagram of the fourth ammonia burner. [Fig. 8B] Schematic diagram of the fourth ammonia burner. [Fig. 8C] Schematic diagram of the fourth ammonia burner. [Fig. 9] Schematic diagram of the fifth ammonia burner. [Fig. 10] Schematic diagram of the sixth ammonia burner. [Fig. 11] Schematic diagram of the seventh ammonia burner. [Fig. 12] Schematic diagram of the eighth ammonia burner.

51: Ammonia burner (ammonia combustion burner)

51A: No. 1 ammonia burner

52: Ammonia injection nozzle

52h: Multiple injection holes

54:Combustion air nozzle

54a: opening

54i: Inner surface

56,56A: Flame protector

60: Flow velocity distribution giving part

61: The first flow velocity distribution providing part

611: Flow path restriction member

611d: Downstream end

616: Rod

Ax: central axis

Claims (13)

An ammonia combustion burner is an ammonia combustion burner used to burn ammonia fuel in a boiler. It has: Ammonia injection nozzle, which is used to inject the aforementioned ammonia fuel; a combustion air nozzle for injecting combustion air from outside the ammonia injection nozzle; and A flow velocity distribution providing unit provides a flow velocity distribution to the combustion air before it is sprayed from the combustion air nozzle. The ammonia combustion burner as described in claim 1, wherein, The flow velocity distribution imparting unit includes a first flow velocity distribution imparting unit disposed inside the combustion air nozzle and imparts a flow velocity distribution to the combustion air flowing inside the combustion air nozzle. The ammonia combustion burner as described in claim 2, wherein, The first flow velocity distribution imparting portion includes a flow path restricting member that extends from the center of the combustion air nozzle toward the outside when viewed along the central axis of the combustion air nozzle, The flow path restricting member forms a gap through which the combustion air can circulate with the inner peripheral surface of the combustion air nozzle. The ammonia combustion burner as described in claim 3, wherein, The flow velocity distribution imparting unit includes a moving device configured to move the flow path restricting member along the central axis. The ammonia combustion burner as described in claim 2, wherein, The first flow velocity distribution imparting portion includes a guide piece having a guide surface inclined at a predetermined inclination angle with respect to the extending direction of the central axis of the combustion air nozzle. The ammonia combustion burner as described in claim 5, wherein, The flow velocity distribution imparting unit includes a guide plate driving device configured to change the inclination angle. The ammonia combustion burner as described in claim 5 or 6, wherein, The first flow velocity distribution imparting part includes a flow restrictor, which is disposed in an area inside the guide piece inside the combustion air nozzle and regulates the flow rate of the combustion air passing through the area. The ammonia combustion burner as described in claim 1, wherein, The aforementioned flow velocity distribution imparting section includes a second flow velocity distribution imparting section, which has: A partition wall that separates a first flow path through which the combustion air can circulate inside the combustion air nozzle, and a second flow path through which the combustion air can circulate outside the first flow path; a first flow rate regulating device that regulates the flow rate of the combustion air supplied to the first flow path; and A second flow rate adjusting device adjusts the flow rate of the combustion air supplied to the second flow path. The ammonia combustion burner as described in claim 8, wherein, The aforementioned ammonia combustion burner is any type of joint type, swirl type, or diffusion type burner. The ammonia combustion burner as described in claim 1 or 2, wherein, The aforementioned ammonia combustion burner is a special combustion burner for ammonia. A boiler having: A stove containing a stove wall; and The ammonia combustion burner as described in claim 1 or 2 is located on the wall of the aforementioned furnace. A boiler having: A stove containing a stove wall; The ammonia combustion burner as described in claim 1 or 2 is located on the wall of the aforementioned furnace; and Other fuel burners are provided on the furnace wall at different positions from the ammonia combustion burners to burn fuels other than ammonia fuel. A boiler as claimed in claim 12, wherein, The boiler is a spiral combustion boiler that uses the ammonia combustion burner and the other fuel burner to perform spiral combustion in the furnace.

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