Ammonia burner

Abstract

According to exemplary embodiments of the present invention, an ammonia burner is provided. The ammonia burner comprises: an air supply pipe configured to provide air to a front end side; a main fuel supply pipe disposed inside the air supply pipe and configured to provide first fuel to the front end side; and a first auxiliary supply pipe disposed outside the main fuel supply pipe with respect to the central axis of the air supply pipe inside the air supply pipe, the first auxiliary supply pipe being configured to provide second fuel containing ammonia to the front end side, and the first auxiliary supply pipe comprising an injection port inclined in a direction away from the central axis of the air supply pipe.

Description

ammonia burner

[0001] The present invention relates to an ammonia burner.

[0002] More specifically, the present invention relates to a burner using fuel containing at least some ammonia.

[0003] As the climate crisis accelerates, the demand for implementing carbon emission reductions is increasing significantly. In the thermal power generation sector, efforts are primarily being made to co-combust hydrogen and ammonia with existing fuels as carbon-free fuels. To achieve this carbon emission reduction, interest in hydrogen and ammonia combustion is growing not only within the power generation sector but across the entire industrial sector that utilizes combustion equipment.

[0004] By-product gases emitted from industrial processes, such as steelmaking or chemical manufacturing, contain combustible substances and are used as fuel in burners to supply heat. These industrial by-product gases generally have a lower calorific value per unit volume (5,000 kcal / Nm³ or less) compared to natural gas or liquefied petroleum gas. In response to demands for carbon emission reduction, processes emitting by-product gases will gradually decrease in the future, and ammonia will be used as a carbon-free fuel to replace them in burners. However, when ammonia is co-fired in burners using conventional fuels such as by-product gases, the nitrogen contained in the fuel is converted into nitrogen oxides, resulting in the emission of large amounts of nitrogen oxides. Consequently, due to capacity limitations of existing denitrification equipment, such as SCR, and environmental emission standards, the co-firing of ammonia is restricted, making measures to reduce nitrogen oxides at the burner level essential.

[0005] [Prior Art Literature]

[0006] [Patent Literature]

[0007] (Patent Document 1) Republic of Korea Registered Patent Publication No. 10-2643208.

[0008] The problem that the technical concept of the present invention aims to solve is to minimize or prevent the generation of nitrogen oxides in an ammonia burner.

[0009] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall details of the specification.

[0010] In order to solve the above-mentioned problem, according to exemplary embodiments of the present invention, an ammonia burner is provided. The ammonia burner comprises: an air supply pipe configured to provide air toward the tip; a main fuel supply pipe disposed inside the air supply pipe and configured to provide a first fuel toward the tip; and a first auxiliary supply pipe disposed outside the main fuel supply pipe with respect to the central axis of the air supply pipe inside the air supply pipe, wherein the first auxiliary supply pipe comprises a first auxiliary supply pipe configured to provide a second fuel containing ammonia toward the tip, and the first auxiliary supply pipe comprises a nozzle inclined in a direction away from the central axis of the air supply pipe.

[0011] The inclination of the above nozzle may be 5 to 40° with respect to the above central axis.

[0012] The first auxiliary supply pipe may be positioned adjacent to the lowest side of the air supply pipe.

[0013] The above nozzle may be tilted in the direction of gravity.

[0014] The diameter of the first auxiliary supply pipe may be smaller than the diameter of the main fuel supply pipe.

[0015] In the inner side of the air supply pipe, a second auxiliary supply pipe positioned outside the main fuel supply pipe with respect to the central axis of the air supply pipe may further include a second auxiliary supply pipe configured to provide the second fuel to the leading edge.

[0016] The second auxiliary supply pipe is positioned adjacent to the uppermost side of the air supply pipe, and the nozzle of the second auxiliary supply pipe may be parallel to the central axis of the air supply pipe.

[0017] A third auxiliary supply pipe is positioned on the inner side of the air supply pipe and positioned further outward from the main fuel supply pipe with respect to the central axis of the air supply pipe, wherein the third auxiliary supply pipe is configured to provide the second fuel to the leading edge, and the third auxiliary supply pipe is positioned adjacent to the first auxiliary supply pipe, and the third auxiliary supply pipe may include a nozzle inclined in a direction away from the central axis of the air supply pipe.

[0018] The nozzle of the third auxiliary supply pipe can be arranged to be parallel to the nozzle of the first auxiliary supply pipe.

[0019] The nozzle of the third auxiliary supply pipe can be tilted toward the end of the nozzle of the first auxiliary supply pipe.

[0020] The air supply pipe comprises a first air supply pipe located in the center, a second air supply pipe surrounding the first air supply pipe, and a supply pipe body fluidly connected to the first air supply pipe and the second air supply pipe to distribute the air to the first air supply pipe and the second air supply pipe; wherein the main fuel supply pipe is disposed inside the first air supply pipe and the first auxiliary supply pipe may be disposed inside the second air supply pipe.

[0021] It may further include an auxiliary fuel supply pipe disposed inside the second air supply pipe and configured to provide the first fuel to the tip side.

[0022] According to exemplary embodiments of the present invention, by optimizing the nozzle arrangement and configuration of the ammonia burner, the generation of nitrogen oxides during the operation of the ammonia burner can be minimized or prevented.

[0023] The various and beneficial advantages and effects of the present invention are not limited to those described above and will be more easily understood in the process of explaining specific embodiments of the present invention.

[0024] FIG. 1 is a drawing for illustrating an ammonia burner according to exemplary embodiments.

[0025] Figure 2 is a front view of an ammonia burner according to Figure 1.

[0026] FIG. 3 is a drawing for explaining the operation of an ammonia burner according to exemplary embodiments.

[0027] FIG. 4 is a drawing for illustrating an ammonia burner according to other exemplary embodiments.

[0028] Fig. 5 is a front view of an ammonia burner according to Fig. 4.

[0029] FIG. 6 is a drawing for illustrating an ammonia burner according to other exemplary embodiments.

[0030] FIG. 7 is a drawing for illustrating an ammonia burner according to other exemplary embodiments.

[0031] FIG. 8 is a drawing for illustrating an ammonia burner according to other exemplary embodiments.

[0032] Fig. 9 is a front view of an ammonia burner according to Fig. 8.

[0033] FIG. 10 is a drawing for illustrating an ammonia burner according to other exemplary embodiments.

[0034] Fig. 11 is a front view of an ammonia burner according to Fig. 10.

[0035] FIG. 12 is a diagram illustrating the location of each fuel supply pipe according to test examples and comparative test examples.

[0036] Figure 13 is a graph showing the experimental results of nitrogen oxide generation.

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0038] In the following descriptions with reference to the drawings, identical or corresponding components are assigned the same reference numerals, and redundant descriptions thereof will be omitted.

[0039] In the following embodiments, the terms first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0040] In the following embodiments, the singular expression includes the plural expression unless the context clearly indicates otherwise.

[0041] In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0042] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0043] Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described consecutively may be performed substantially simultaneously or proceed in the reverse order of the description.

[0044] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0045] The present invention will be described in detail below through each embodiment. It should be noted that each embodiment described in this specification is not limited to a single embodiment but may also be combined with other embodiments. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0046] The present invention will be described in detail below through examples. However, it should be noted that the following examples are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0047]

[0048] (Example 1)

[0049] FIG. 1 is a drawing for illustrating an ammonia burner (100) according to exemplary embodiments. FIG. 2 is a front view of the ammonia burner (100) according to FIG. 1.

[0050] Referring to FIGS. 1 and 2, the ammonia burner (100) includes an air supply pipe (110), a main fuel supply pipe (120), and a first auxiliary supply pipe (130).

[0051] The air supply pipe (110) may be configured to provide air toward the tip section (E). In the present invention, the tip section (E) refers to the tip section (E) of the ammonia burner (100) unless otherwise defined. Air, the first fuel, and the second fuel are injected at the tip section (E) of the ammonia burner (100), and flames are formed in the forward region of the tip section (E). In the present invention, providing toward the tip section (E) means supplying air, the first fuel, or the second fuel so that they are injected at the tip section (E) to form flames. As long as the air, the first fuel, or the second fuel can flow toward the tip section (E) to form flames, the fluid flow path inside the ammonia burner (100) is not particularly limited.

[0052] The air supply pipe (110) may include an air flow pipe (111) through which air mainly flows and a supply pipe body (112) that receives air from the outside. Although not particularly limited, the air flow pipe (111) may be located at one end (110E1) on the leading end (E) side of the air supply pipe (110). The supply pipe body (112) may be located at the other end (110E2) opposite to the one end (110E1) of the air supply pipe (110). In FIG. 1, for convenience of illustration, the air supply pipe (110) is shown with a structure in which the supply pipe body (112) is bent from the air flow pipe (111). However, the shape of the air supply pipe (110) is not particularly limited as long as it can receive air from the outside and supply it to the leading end (E) side, and various members described later can be installed inside.

[0053] The main fuel supply pipe (120) may be configured to be positioned inside the air supply pipe (110) and to provide the first fuel to the leading edge (E). As a non-limiting example, the main fuel supply pipe (120) may be a pipe that allows independent flow of the first fuel to the leading edge (E). The main fuel supply pipe (120) may be installed through the air supply pipe (110). More specifically, it may be installed through the air flow pipe (111). The main fuel supply pipe (120) may have a other end (120E2) opposite to the leading edge (E) end (120E1) that is fluidly connected to an external device that provides the first fuel. The first fuel provided to the other end (120E2) may flow to the one end (120E1) of the main fuel supply pipe (120) and be provided to the leading edge (E).

[0054] The first fuel is a by-product gas originating from various industrial processes. The type of by-product gas is not particularly limited as long as it contains combustible components. As a non-limiting example, the by-product gas may be a gas originating from one or more of steelmaking facilities, ammonia reforming plants, petrochemical plants, power plants, incineration facilities, and combinations thereof. As such, the by-product gas contains combustible substances such as hydrogen, methane, and carbon monoxide, and utilizing it as fuel for a burner can improve the energy efficiency of the entire process. In terms of reducing nitrogen oxide generation, more preferably, the first fuel may not substantially contain nitrogen.

[0055] The first auxiliary supply pipe (130) is positioned inside the air supply pipe (110), and is positioned further outward than the main fuel supply pipe (120) with respect to the central axis (C) of the air supply pipe (110). That is, it can be positioned so that the distance from the central axis (C) of the air supply pipe (110) to the first auxiliary supply pipe (130) is longer than the distance from the central axis (C) of the air supply pipe (110) to the main fuel supply pipe (120). The first auxiliary supply pipe (130) can be configured to provide a second fuel containing ammonia to the leading edge (E).

[0056] The second fuel is a gaseous fuel mainly containing ammonia. The ammonia content of the second fuel is not particularly limited, but as a non-limiting example, it may be 60 to 100% by volume. In addition, the second fuel may further include gases such as hydrogen and nitrogen that may be contained in the second fuel during the process of producing and transporting the ammonia of the second fuel, but is not necessarily limited thereto. More preferably, from the perspective of the calorific value of the ammonia burner, the second fuel may be composed of ammonia.

[0057] The first fuel discharged from the main fuel supply pipe (120) reacts sufficiently with air to form a main flame. At this time, if the first fuel and the second fuel containing ammonia are burned together, a large amount of nitrogen oxides may be formed. However, according to exemplary embodiments, the first auxiliary supply pipe (130) is positioned relatively outward compared to the main fuel supply pipe (120). Therefore, the direct reaction of the second fuel with the first fuel and air can be minimized, thereby reducing the generation of nitrogen oxides.

[0058] According to exemplary embodiments, the first auxiliary supply pipe (130) may be positioned adjacent to the lowest side of the air supply pipe (110). As a result, the second fuel flows and burns in the lower part of the main flame forming space, thereby minimizing the reaction between the main flame and the second fuel. The lowest side of the air supply pipe (110) refers to the lowest point on the inner surface of the air flow pipe (111).

[0059] As a non-limiting example, the first auxiliary supply pipe (130) may be a pipe that allows independent flow of the second fuel toward the leading end (E). The first auxiliary supply pipe (130) may be a separate pipe distinct from the main fuel supply pipe (120). The first auxiliary supply pipe (130) may be installed through the air supply pipe (110). More specifically, it may be installed through the air flow pipe (111). The other end (130E2) opposite the leading end (E) side end (130E1) of the first auxiliary supply pipe (130) may be fluidly connected to an external device that provides the second fuel. The second fuel provided to the other end (130E2) may flow to the leading end (130E1) of the first auxiliary supply pipe (130) and be provided toward the leading end (E).

[0060] The first auxiliary supply pipe (130) includes a nozzle (131) that is inclined away from the central axis (C) of the air supply pipe. As a result, the ammonia of the second fuel is injected into an area separated from the main flame, thereby minimizing the direct reaction of the second fuel with the main flame. According to exemplary embodiments, when the first auxiliary supply pipe (130) is positioned adjacent to the lowest side of the air supply pipe (110), the nozzle (131) may be inclined in the direction of gravity.

[0061] The inclination (θ) of the nozzle (131) may be 5 to 40° with respect to the central axis (C). If the inclination (θ) of the nozzle (131) is less than 5°, the second fuel may meet the first fuel and burn in the main flame. In this case, an excessive amount of nitrogen oxides may be generated. If the inclination (θ) of the nozzle (131) exceeds 40°, ammonia slip may occur in which the ammonia of the second fuel is not burned and some of it leaks out to the outside. More preferably, in terms of reducing nitrogen oxides and preventing ammonia slip, the inclination (θ) of the nozzle (131) may be 10 to 30°. More specifically, the inclination (θ) of the nozzle (131) may be 10 to 20°.

[0062] FIG. 3 is a drawing for explaining the operation of an ammonia burner (100) according to exemplary embodiments.

[0063] Referring to FIG. 3, air, a first fuel, and a second fuel are injected at the leading edge (E) of the ammonia burner (100) to form various flames.

[0064] A first fuel and air react at the center of the front end (E) of the ammonia burner (100) to form a main flame (MF). More specifically, the main flame (MF) is formed through a combustion reaction between a combustible component in the first fuel and oxygen in the air. The main flame (MF) can be formed in the direction of injection of the first fuel and air at the center of the front end (E) of the ammonia burner (100).

[0065] Around the main flame (MF), a secondary fuel and air react to form a secondary flame (NF). The main flame (MF) is formed by byproduct gases generated from industrial facilities and may not possess sufficient heat. Consequently, the insufficient heat of the main flame (MF) can be supplemented by forming a secondary flame using a secondary fuel containing ammonia.

[0066] According to exemplary embodiments, the auxiliary flame (NF) may include an ammonia-rich region (NF1), an ammonia flame region (NF2), and a residual ammonia flame region (NF3).

[0067] More specifically, the ammonia-rich region (NF1) is a region formed between the main flame (MF) and the leading edge (E) of the ammonia burner (100). Most of the air injected from the air supply pipe (110) reacts with the first fuel to form the main flame (MF). In contrast, the second fuel is injected at an angle to the direction of the air injection, so it may not react sufficiently with the air at the leading edge (E) of the ammonia burner (100). As a result, the second fuel can be concentrated in an air-deficient state between the leading edge (E) of the ammonia burner (100) and the main flame (MF). Thus, the second fuel is concentrated in an air-deficient state, and the combustion reaction does not occur as actively as in the main flame (MF). Therefore, the reaction occurs relatively slowly in the ammonia-rich region (NF1) and can form the ammonia flame region (NF2) at the trailing edge. By delaying the reaction time between ammonia and oxygen, the reaction for the generation of nitrogen oxides can be suppressed. Furthermore, the generation of nitrogen oxides can be minimized in the overall combustion reaction of the second fuel.

[0068] According to exemplary embodiments, the ammonia burner (100) may be configured such that the injection speed of the second fuel is faster than the injection speed of the first fuel. This minimizes the drawing of the second fuel into the main flame (MF), thereby sufficiently forming an ammonia-rich region (NF1) and an ammonia combustion region (NF2), thereby minimizing the generation of nitrogen oxides. According to exemplary embodiments, the diameter of the first auxiliary supply pipe (130) may be smaller than the diameter of the main fuel supply pipe (120).

[0069] At the end of the second fuel injection direction of the ammonia-rich region (NF1), some air that did not react with the first fuel may undergo a combustion reaction with the ammonia concentrated in the ammonia-rich region (NF1) to form an ammonia flame region (NF2). The ammonia-rich region (NF1) and the ammonia flame region (NF2) may partially overlap. In this way, the second fuel is combusted after forming the ammonia-rich region (NF1) in a region with relatively low oxygen levels. As a result, the ammonia-rich region (NF1) is formed widely and reacts with a low concentration of oxygen for a sufficiently long time, thereby minimizing the generation of nitrogen oxides caused by ammonia. Furthermore, even if nitrogen oxides are formed due to incomplete combustion, the ammonia in the ammonia-rich region (NF1) can act as a reducing agent to reduce the nitrogen oxides to nitrogen and water.

[0070] As a non-limiting example, the portion of the ammonia flame region (NF2) that overlaps with or is adjacent to the ammonia rich region (NF1) may be formed at an angle in the direction of the second fuel injection.

[0071] At the rear end of the ammonia-rich region (NF2), the injection momentum of the first auxiliary supply pipe (130) disappears, and only the buoyancy of the second fuel and the combustion gases of the second fuel remains, allowing the gases to rise upward. The gases rising at the rear end of the ammonia-rich region (NF2) may contain unburned residual ammonia.

[0072] Residual ammonia is combusted by the main flame (MF) and air, forming a residual ammonia flame region (NF3). As a result, ammonia slip caused by unburned ammonia can be minimized. Thus, according to exemplary embodiments of the present invention, ammonia is not supplied directly to the main flame (MF). That is, the ammonia of the second fuel forms a separate ammonia rich region (NF1) and an ammonia flame region (NF2), and the unburned ammonia is only combusted indirectly by the thermal energy of the main flame (MF) and air. As a result, unburned components can be minimized, and the generation of nitrogen oxides can be effectively reduced.

[0073]

[0074] (Example 2)

[0075] FIG. 4 is a drawing for illustrating an ammonia burner (200) according to other exemplary embodiments. FIG. 5 is a front view of the ammonia burner (200) according to FIG. 4.

[0076] Referring to FIGS. 4 and 5, the ammonia burner (200) may further include a second auxiliary supply pipe (140) positioned on the inner side of the air supply pipe (110), positioned further outward from the main fuel supply pipe (110) with respect to the central axis (C) of the air supply pipe (110). That is, the distance from the central axis (C) of the air supply pipe (110) to the second auxiliary supply pipe (140) may be longer than the distance from the central axis (C) of the air supply pipe (110) to the main fuel supply pipe (120). This allows for the minimization of the generation of nitrogen oxides. The second auxiliary supply pipe (140) may be configured to provide the second fuel to the leading edge (E). In this way, the maximum combustion amount of the ammonia burner (200) can be increased by additionally burning the second fuel. Additionally, the supply path of the second fuel can be dispersed. As a result, when the supply amount of the second fuel is increased, the second fuel can be prevented from becoming excessively concentrated in the ammonia-rich region (NF1) and causing ammonia slip.

[0077] According to exemplary embodiments, the second auxiliary supply pipe (140) is positioned adjacent to the uppermost side of the air supply pipe (110), and the nozzle (141) of the second auxiliary supply pipe (140) may be parallel to the central axis (C) of the air supply pipe (110). As a result, the second fuel is mixed with the first fuel and does not burn in the main flame (MF), thereby minimizing the generation of nitrogen oxides.

[0078] According to exemplary embodiments, the diameter of the second auxiliary supply pipe (140) may be smaller than the diameter of the main fuel supply pipe (120). This allows the injection speed of the second fuel to be controlled faster than the injection speed of the first fuel. Consequently, the ammonia of the second fuel can be distributed more widely in three-dimensional space. At this time, by creating an air-deficient environment in the area, the reaction time with air can be delayed, thereby reducing the generation of nitrogen oxides.

[0079] As a non-limiting example, the second auxiliary supply pipe (140) may be a pipe that allows independent flow of the second fuel toward the leading end (E). The second auxiliary supply pipe (140) may be a separate pipe distinct from the main fuel supply pipe (120). The second auxiliary supply pipe (140) may be installed through the air supply pipe (110). More specifically, it may be installed through the air flow pipe (111). The other end (140E2) opposite the leading end (E) side end (140E1) of the second auxiliary supply pipe (140) may be fluidly connected to an external device that provides the second fuel. The second fuel provided through the other end (140E2) may flow to the leading end (130E1) of the first auxiliary supply pipe (140) and be provided toward the leading end (E). The other end (140E2) of the second auxiliary supply pipe (140) can be fluidly connected to the other end (130E2) of the first auxiliary supply pipe (130). In this case, the distribution of the second fuel can be performed more easily.

[0080] In addition, the configuration of the ammonia burner (100) according to the above-described embodiment can be applied in the same way to the ammonia burner (200) according to the present embodiment. Therefore, specific descriptions of overlapping configurations are omitted.

[0081]

[0082] (Example 3)

[0083] FIG. 6 is a drawing for illustrating an ammonia burner (300) according to other exemplary embodiments. FIG. 7 is a drawing for illustrating an ammonia burner (300') according to other exemplary embodiments.

[0084] Referring to FIGS. 6 and 7, the ammonia burner (300, 300') further includes a third auxiliary supply pipe (150, 150') positioned outside the main fuel supply pipe (120) with respect to the central axis (C) of the air supply pipe (110). The third auxiliary supply pipe (150, 150') is configured to provide a second fuel to the leading edge (E).

[0085] The third auxiliary supply pipe (150, 150') can be positioned adjacent to the first auxiliary supply pipe (130). This allows the heat content of the auxiliary flame (NF) to be further increased and makes it easier to control the ammonia content relative to the total fuel.

[0086] According to exemplary embodiments, the third auxiliary supply pipe (150, 150') may include a nozzle (151, 151') inclined away from the central axis (C) of the air supply pipe (110). This makes it easier to control the ammonia-rich region (NF1).

[0087] More specifically, depending on the environment in which the ammonia burner (300, 300') is used, it is necessary to appropriately control the shape of the ammonia-rich region (NF1) and the ammonia concentration. As an example, if the ammonia-rich region (NF1) is formed excessively wide, the contact area with air that has not reacted with the first fuel increases, and an ammonia flame region (NF2) can be easily formed. In this case, it may be more desirable in terms of replenishing the heat of the main flame (MF). However, as the ammonia flame region (NF2) becomes excessively wide, the possibility of unburned ammonia generation may increase. Therefore, in an environment where it is necessary to form the ammonia flame region (NF2) quickly, according to exemplary embodiments, the nozzle (151) of the third auxiliary supply pipe (150) may be arranged parallel to the nozzle (131) of the first auxiliary supply pipe (130).

[0088] As another example, as the supply of ammonia between the ammonia burner (300, 300') and the main flame (MF) increases, an ammonia-rich region (NF1) can be easily formed. However, if ammonia is supplied in excess, ammonia slip may occur. In environments where nitrogen oxides are strictly controlled, according to exemplary embodiments, the nozzle (151') of the third auxiliary supply pipe (150') may be inclined toward the end of the nozzle (131) of the first auxiliary supply pipe (130).

[0089] Furthermore, the configurations of the ammonia burners (100, 200) according to the embodiments described above can be applied in the same way to the ammonia burners (300, 300') according to the present embodiment. Therefore, specific descriptions of overlapping configurations are omitted.

[0090]

[0091] (Example 4)

[0092] FIG. 8 is a drawing for illustrating an ammonia burner (400) according to other exemplary embodiments. FIG. 9 is a front view of the ammonia burner (400) according to FIG. 8.

[0093] Referring to FIGS. 8 and 9, the air supply pipe (410) may include a first air supply pipe (411) located in the center, a second air supply pipe (412) surrounding the first air supply pipe (411), and a supply pipe body (413) fluidly connected to the first air supply pipe (411) and the second air supply pipe (412) to distribute air to the first air supply pipe (411) and the second air supply pipe (412). That is, the air flow pipe (111) may have a form divided into a plurality of zones.

[0094] As a result, by controlling the air flow rate of each air supply pipe (411, 412), an oxygen-sufficient region and a relatively oxygen-deficient region can be formed at the tip (E) of the ammonia burner (500). Consequently, an ammonia-rich region (NF1) in an air-deficient state can be formed more easily. Consequently, the generation of nitrogen oxides can be reduced or prevented.

[0095] According to exemplary embodiments, the main fuel supply pipe (120) may be positioned inside the first air supply pipe (411), and the first auxiliary supply pipe (130) may be positioned inside the second air supply pipe (412). This allows for easier formation of an ammonia-rich region (NF1), thereby further reducing the emission of nitrogen oxides.

[0096] Auxiliary supply pipes positioned outside the main fuel supply pipe (120) with respect to the central axis may be positioned in the second air supply pipe (412). More specifically, the second auxiliary supply pipe (140) may be positioned in the second air supply pipe (412). The third auxiliary supply pipe (150, 150') may be positioned in the second air supply pipe (412). In this way, the injection position of the second fuel can be optimized.

[0097] Furthermore, the configurations of the ammonia burners (100, 200, 300, 300') according to the embodiments described above can be applied in the same way to the ammonia burner (400) according to the present embodiment. Therefore, specific descriptions of overlapping configurations are omitted.

[0098]

[0099] (Example 5)

[0100] FIG. 10 is a drawing for illustrating an ammonia burner (500) according to other exemplary embodiments. FIG. 11 is a front view of the ammonia burner (500) according to FIG. 10.

[0101] Referring to FIGS. 10 and 11, the ammonia burner (500) may further include an auxiliary fuel supply pipe (121) positioned inside the second air supply pipe (412) and configured to supply the first fuel to the leading end (E). This allows the heat of the main flame (MF) to be increased, thereby further increasing the total heat produced by the ammonia burner (500). Additionally, the temperature of the trailing end of the main flame (MF) can be increased to promote the combustion of unburned ammonia. This effectively prevents ammonia slip.

[0102] Furthermore, the configurations of the ammonia burners (100, 200, 300, 300', 400) according to the above-described embodiments can be applied in the same way to the ammonia burner (500) according to the present embodiment. Therefore, specific descriptions of overlapping configurations are omitted.

[0103] In other words, although each embodiment has been described separately for the convenience of explanation, a person skilled in the art will be able to appropriately combine the configurations of the ammonia burners according to the above-described embodiments without departing from the technical spirit of the present invention.

[0104] Experiments were conducted to determine the amount of nitrogen oxides generated according to the injection direction of the second fuel. During this experiment, the amount of nitrogen oxides generated was measured while increasing the ammonia content (hereinafter referred to as the ammonia co-firing ratio) relative to the total injection amounts of the first and second fuels.

[0105] (Test Example 1)

[0106] A main fuel supply pipe providing a first fuel is positioned in the center of the air supply pipe. An auxiliary supply pipe providing a second fuel is positioned adjacent to the lowest side of the air supply pipe. The auxiliary supply pipe includes a nozzle having an inclination of approximately 15° from the central axis of the air supply pipe.

[0107] (Test Example 2)

[0108] The test was conducted under the same conditions as Test Example 1 above, except that an auxiliary supply pipe having a nozzle substantially parallel to the central axis of the air supply pipe was used.

[0109] (Test Example 3)

[0110] The test was conducted under the same conditions as Test Example 1 above, except that an auxiliary supply pipe was used that has a nozzle substantially parallel to the central axis of the air supply pipe and is positioned adjacent to the uppermost side of the air supply pipe.

[0111] (Comparative Test Example 1)

[0112] The test was conducted under the same conditions as Test Example 1, except that an auxiliary supply pipe was placed in a location adjacent to the main fuel supply pipe.

[0113] FIG. 12 is a diagram illustrating the locations of each fuel supply pipe according to test examples and comparative test examples. More specifically, FIG. 12(a) is a schematic diagram illustrating the arrangement of auxiliary supply pipes according to Test Example 1. FIG. 12(b) is a schematic diagram illustrating the arrangement of auxiliary supply pipes according to Test Example 2. FIG. 12(c) is a schematic diagram illustrating the arrangement of auxiliary supply pipes according to Test Example 3. FIG. 12(d) is a schematic diagram illustrating the arrangement of auxiliary supply pipes according to Comparative Test Example 1. In FIG. 12, the supply pipe into which the second fuel is injected is indicated differently from the supply pipe into which the first fuel and air are injected.

[0114] The emission of nitrogen oxides was measured by installing a separate sampling port in a flue gas duct spaced more than 10m away from the ammonia burner, sucking in and sampling the flue gas generated after combustion, and using a gas analyzer to measure the content of nitrogen oxides (NO, and NO2) in the flue gas.

[0115] Figure 13 is a graph showing the experimental results of nitrogen oxide generation.

[0116] Referring to FIG. 13, it can be seen that in Comparative Test Example 1, where a second fuel containing ammonia was injected into the center of the air supply pipe, an excess amount of nitrogen oxides was generated.

[0117] In contrast, in Test Examples 1, 2, and 3, where the second fuel was injected from the outside of the air supply pipe, the amount of nitrogen oxides generated was reduced, and it was confirmed that the amount of nitrogen oxides generated actually decreased as the ammonia co-firing ratio increased. This is interpreted as meaning that as the ammonia co-firing ratio increased, an ammonia-rich region was effectively formed, and the ammonia in the ammonia-rich region also acted as a reducing agent for nitrogen oxides. In particular, in Test Example 1, where the injection nozzle had a predetermined slope, it was confirmed that the amount of nitrogen oxides generated was relatively further reduced. This is judged to be because an ammonia-rich region in an oxygen-deficient state was formed more stably.

[0118] Although the invention has been described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims.

[0119]

[0120] (Explanation of symbols)

[0121] 100, 200, 300, 300', 400, 500: Ammonia burner

[0122] 110,410: Air supply pipe

[0123] 120: Main fuel supply line

[0124] 121: Auxiliary fuel supply line

[0125] 130: 1st auxiliary supply pipe

[0126] 131: Nozzle of the first auxiliary supply pipe

[0127] 140: Second auxiliary supply pipe

[0128] 141: Nozzle of the second auxiliary supply pipe

[0129] 150: 3rd auxiliary supply pipe

[0130] 151: Nozzle of the third auxiliary supply pipe

Claims

1. An air supply pipe configured to supply air to the leading edge; A main fuel supply pipe disposed inside the air supply pipe and configured to provide a first fuel to the leading end; and A first auxiliary supply pipe positioned on the inner side of the air supply pipe, further outward from the main fuel supply pipe with respect to the central axis of the air supply pipe, wherein the first auxiliary supply pipe is configured to provide a second fuel containing ammonia to the leading edge. The above first auxiliary supply pipe is an ammonia burner comprising a nozzle inclined in a direction away from the central axis of the air supply pipe.

2. In Paragraph 1, An ammonia burner in which the inclination of the above-mentioned nozzle is 5 to 40° with respect to the above-mentioned central axis.

3. In Paragraph 1, The above first auxiliary supply pipe is an ammonia burner positioned adjacent to the lowest side of the above air supply pipe.

4. In Paragraph 3, The above-mentioned nozzle is an ammonia burner that is inclined in the direction of gravity.

5. In Paragraph 1, The diameter of the first auxiliary supply pipe is smaller than the diameter of the main fuel supply pipe of the ammonia burner.

6. In Paragraph 1, An ammonia burner further comprising a second auxiliary supply pipe positioned on the inner side of the air supply pipe, further positioned on the outer side of the main fuel supply pipe with respect to the central axis of the air supply pipe, wherein the second auxiliary supply pipe is configured to provide the second fuel to the leading edge.

7. In Paragraph 6, The second auxiliary supply pipe is positioned adjacent to the uppermost side of the air supply pipe, and The nozzle of the second auxiliary supply pipe is an ammonia burner parallel to the central axis of the air supply pipe.

8. In Paragraph 1, A third auxiliary supply pipe is positioned on the inner side of the air supply pipe, further comprising a third auxiliary supply pipe positioned on the outer side of the main fuel supply pipe with respect to the central axis of the air supply pipe, wherein the third auxiliary supply pipe is configured to provide the second fuel to the leading edge side. The third auxiliary supply pipe is positioned adjacent to the first auxiliary supply pipe, and The above third auxiliary supply pipe is an ammonia burner comprising a nozzle inclined in a direction away from the central axis of the air supply pipe.

9. In Paragraph 8, The nozzle of the third auxiliary supply pipe mentioned above is, An ammonia burner positioned parallel to the nozzle of the first auxiliary supply pipe.

10. In Paragraph 8, The nozzle of the third auxiliary supply pipe mentioned above is, An ammonia burner inclined toward the end of the nozzle of the first auxiliary supply pipe.

11. In Paragraph 1, The above air supply pipe is, A first air supply pipe located at the center, a second air supply pipe surrounding the first air supply pipe, and a supply pipe body fluidly connected to the first air supply pipe and the second air supply pipe to distribute air to the first air supply pipe and the second air supply pipe; comprising The above main fuel supply pipe is positioned inside the first air supply pipe, and The above first auxiliary supply pipe is an ammonia burner positioned inside the above second air supply pipe.

12. In Paragraph 11, An ammonia burner further comprising an auxiliary fuel supply pipe disposed inside the second air supply pipe and configured to provide the first fuel to the tip side.

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