Ammonia combustion nozzle, ammonia fuel pilot burner comprising same, and ammonia combustor comprising same

Abstract

The present invention relates to an ammonia combustion nozzle, an ammonia fuel pilot burner comprising same, and an ammonia combustor comprising same, the nozzle comprising: a coupling part coupled to a pilot burner body; a protruding part inserted into the pilot burner body so as to form an annular flow path extending in the axial direction of the pilot burner body between the protruding part and the pilot burner body; an ignition rod insertion hole penetrating through the closed end surface of the protruding part; and one or more injection holes formed in the protruding part so as to jet, into the protruding part, a mixed gas flowing in through the annular flow path, so that a swirling flow is formed inside the protruding part. Therefore, the present invention jets, in the tangential direction of the inner surface of the combustion nozzle, the mixed gas supplied to the combustion nozzle so as to form a strong swirling flow and, simultaneously, forms a strong backflow in the axial direction of the combustion nozzle and allows ammonia fuel to remain in the vicinity of the ignition rod, and thus enables ammonia fuel to be smoothly ignited without the input of other fuels or electrical energy, and can improve flame stability.

Description

Ammonia combustion nozzle, ammonia fuel pilot burner including the same, and ammonia combustor including the same

[0001] The present invention relates to an ammonia combustion nozzle, a pilot burner including the same, and an ammonia combustor including the same, and more particularly, to an ammonia combustion nozzle which is assembled to a burner body to form an ignition chamber surrounding the tip of an ignition rod, the ignition chamber including an injection hole for forming a strong swirling flow inside and a structure for stabilizing a flame, thereby enabling stable initial ignition and flame maintenance of ammonia fuel without inputting other fuel or electric energy, an ammonia fuel pilot burner including the same, and an ammonia combustor including the same.

[0002] To reduce carbon dioxide emissions to prevent global warming and climate change, demand is rapidly increasing for carbon-free fuels that can replace carbon-based fuels such as coal and oil, which emit large amounts of carbon dioxide when burned. Ammonia, which does not emit carbon dioxide when burned, is attracting attention as a carbon-free fuel that, along with hydrogen, can replace existing carbon-based fuels. However, compared to hydrogen, ammonia has a lower calorific value, a higher ignition temperature, making initial ignition difficult, and a slow combustion rate that makes flame stability difficult to ensure. Therefore, ammonia has been used only in combination with other fuels such as hydrogen, and a combustors that use ammonia alone have not yet been used or commercialized.

[0003] In general, when the capacity (or maximum heat load) of a combustor is low, a spark ignition method is adopted, and when the capacity is 200 kW or higher, a pilot burner is applied to induce stable initial combustion or maintain the flame even when the load changes to prevent explosion. However, the conventional pilot burner used in a general combustor cannot burn ammonia, and therefore cannot be used in an ammonia combustor.

[0004] Meanwhile, as a prior art document related to an ignition system that efficiently combusts ammonia, Japanese Patent No. 7324044 (registered on August 1, 2023, hereinafter referred to as "prior art document 1") has been proposed. As illustrated in Fig. 1, the ignition system according to prior art document 1 includes a reformer (1) that reforms ammonia gas to produce hydrogen gas having excellent combustibility, and is configured such that the hydrogen gas produced in the reformer (1) is supplied to a pilot burner (2).

[0005] The ignition system of the above prior art document 1 supplies hydrogen gas generated from a reformer (1) to a pilot burner (2) to ignite the pilot burner (2), and supplies ammonia gas after the pilot burner (2) is ignited, thereby enabling combustion of flame-retardant ammonia gas.

[0006] However, prior art document 1 has a reformer that generates hydrogen gas by reforming ammonia gas through dielectric barrier discharge, and thus has problems in that the structure and control are complex, a compact configuration is difficult, and flame stability is difficult to maintain by combustion of ammonia gas alone.

[0007] The present invention has been devised to solve the above problems, and the purpose of the present invention is to provide an ammonia combustion nozzle capable of stably igniting ammonia fuel without inputting other fuel or electric energy, a pilot burner including the nozzle, and an ammonia combustor including the nozzle.

[0008] Another object of the present invention is to provide an ammonia combustion nozzle, a pilot burner including the same, and an ammonia combustor including the same, in which a mixed gas supplied to the combustion nozzle is sprayed in a tangential direction to the inner surface of the combustion nozzle to generate a strong swirling flow inside the combustion nozzle.

[0009] Another object of the present invention is to provide an ammonia combustion nozzle capable of stabilizing an ammonia flame by forming an ignition chamber of sufficient length in which a flame is started inside the nozzle and ejected to the outside, and in which the flame is started and grows, a pilot burner including the same, and an ammonia combustor including the same.

[0010] The present invention is characterized by comprising: a coupling part coupled to a pilot burner body to perform a task for achieving the above-described purpose and eliminating conventional problems; a protrusion inserted into the interior of the pilot burner body to form an annular passage extending in the axial direction of the pilot burner body between the pilot burner body and the pilot burner body; an ignition rod insertion hole formed by penetrating a closed end surface of the protrusion; and one or more injection holes formed in the protrusion to inject a gas mixture flowing into the annular passage into the inside of the protrusion to form a swirling flow inside the protrusion.

[0011] In addition, the above-mentioned coupling part may be coupled to the tip of the pilot burner body, and the protrusion may be integrally formed with the coupling part so as to protrude from the coupling part and be inserted into the interior of the pilot burner body.

[0012] Additionally, it is preferable that the protrusion has an outer diameter smaller than the joining portion.

[0013] Additionally, screw threads may be formed on the outer surface of the above-mentioned joint and the inner surface of the pilot burner body so that they can be interlocked and joined to each other.

[0014] Additionally, the injection hole may be formed to penetrate the protrusion so as to connect the inner and outer surfaces of the protrusion, but extend in a tangential direction to the inner surface.

[0015] Additionally, a conical axle may be formed protruding at the end of the protrusion.

[0016] In addition, one injection hole is formed in the protrusion, and it is preferable that the ratio of the injection hole diameter to the ignition chamber radius is 0.475 to 0.575.

[0017] In addition, two injection holes are formed in the protrusion, and it is preferable that the ratio of the injection hole diameter to the ignition chamber radius is 0.400 to 0.475.

[0018] Additionally, the injection hole may be formed with an orifice structure to increase the flow rate of the mixed gas ejected into the protrusion.

[0019] In addition, it may further include an ignition chamber extending in the axial direction of the pilot burner body from the end face of the protrusion and penetrating the joint, so that a flame generated inside is ejected to the outside.

[0020] And, it is preferable that the ignition chamber have a depth that is more than five times the radius.

[0021] Meanwhile, the ammonia fuel pilot burner of the present invention is characterized by including a pilot burner body having a fuel input portion and an oxidizer input portion, and including a cylindrical transfer pipe through which a mixture of ammonia gas and air, which is input into the fuel input portion and the oxidizer input portion, respectively, flows; a spark igniter mounted on the pilot burner body and having an ignition rod extending through the interior of the transfer pipe; and an ammonia combustion nozzle coupled to an end of the transfer pipe.

[0022] Additionally, the material of the ammonia combustion nozzle may be stainless steel.

[0023] And, the ammonia combustion nozzle may have a ceramic tube, a quartz tube, or a ceramic coating layer formed on the inner surface.

[0024] Meanwhile, the ammonia combustor of the present invention is characterized by including a combustor body having an outlet through which ammonia fuel and an oxidizer are supplied internally and through which a flame is emitted; and an ammonia fuel pilot burner of claim 12, which is mounted on the combustor body to ignite the ammonia fuel supplied to the combustor body and maintain the flame.

[0025] According to the ammonia combustion nozzle of the present invention, the ammonia fuel pilot burner including the same, and the ammonia combustor including the same, the mixed gas supplied to the combustion nozzle is ejected in the tangential direction of the inner surface of the combustion nozzle to form a strong swirling flow, and at the same time, a strong countercurrent is formed in the axial direction of the combustion nozzle, and the countercurrent formed in the combustion nozzle in this way causes the ammonia fuel with a slow combustion speed to remain upstream of the combustion nozzle, i.e., around the ignition rod, so that the ammonia fuel can be stably ignited without inputting other fuel or electric energy, and the flame stability can be improved.

[0026] In particular, since the entire structure for changing the flow direction of the mixed gas moving in the axial direction of the pilot burner to the inner tangential direction of the combustion nozzle and being injected is formed inside the pilot body, the fuel supply structure can be simplified, and since the fuel supply structure is not exposed to the outside, there is no risk of fuel leakage, and smooth installation is possible even when the space around the pilot burner mounting location is narrow.

[0027] Furthermore, since the flame starts in the ignition chamber inside the combustion nozzle and grows within the ignition chamber of sufficient depth and is ejected to the outside, flame stability can be further improved.

[0028] In addition, the combustion nozzle, which is screwed onto the pilot burner body, is easily detachable, so it can be easily replaced if replacement is required due to aging or damage.

[0029] In addition, the conical throttle formed at the inner end of the combustion nozzle reduces the pressure loss that occurs during the process of the mixed gas flowing into the combustion nozzle, thereby preventing the intensity of the swirl flow from being reduced due to the pressure loss of the mixed gas.

[0030] Figure 1 is a structural diagram of an ignition system according to prior art literature.

[0031] FIG. 2 is a perspective view showing an ammonia combustion nozzle according to one embodiment of the present invention separated from a pilot burner body;

[0032] Figure 3 is a perspective view of an ammonia combustion nozzle according to one embodiment of the present invention;

[0033] Figure 4a is a cross-sectional view showing the structure of an injection hole provided in an ammonia combustion nozzle according to one embodiment of the present invention.

[0034] Figure 4b is a cross-sectional view showing the structure of a spray hole formed with an orifice structure.

[0035] Figure 5 is a structural diagram showing a state in which an ammonia combustion nozzle according to one embodiment of the present invention is connected to the tip of a pilot burner body.

[0036] Figure 6 is a graph showing the number of swirls according to changes in the number of injectors, diameter of injectors, and radius of ignition chamber.

[0037] Figure 7 is a perspective view of a pilot burner for ammonia fuel according to one embodiment of the present invention;

[0038] Figure 8 is a structural diagram of an ammonia combustor according to one embodiment of the present invention.

[0039] [Explanation of symbols]

[0040] 10: Nozzle for ammonia combustion 110: Joint

[0041] 111: Screw thread 120: Protrusion

[0042] 130: Ignition rod insertion hole 140: Injection hole

[0043] 150: Axle 160: Ignition chamber

[0044] 161: Coating layer

[0045] 20: Pilot burner for ammonia fuel

[0046] 210: Pilot burner body 211: Inlet block

[0047] 211a: Fuel input port 211b: Oxidizer input port

[0048] 212: Support block 213: Transfer pipe

[0049] 213a: Screw 220: Spark igniter

[0050] 221: Spark plug 222: Spark rod

[0051] 310: Combustor body 311: Outlet

[0052] Hereinafter, a preferred embodiment of the present invention will be described in detail based on matters illustrated in the drawings. However, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0053] As illustrated in FIGS. 2 to 5, an ammonia combustion nozzle (10) according to one embodiment of the present invention is formed in an overall cylindrical structure and is mounted on the tip of a pilot burner body (210), and includes a coupling portion (110), a protrusion (120), an ignition rod insertion hole (130), and an injection hole (140).

[0054] The above-mentioned connecting portion (110) is a portion connected to the tip of the pilot burner body (210), and has a cylindrical structure, with screw threads (111) formed on the outer surface thereof, and screw threads (213a) corresponding to the screw threads (111) formed on the outer surface of the connecting portion (110) are formed on the inner surface of the tip of the pilot burner body (210). Therefore, the connecting portion (110) can be connected to the tip of the pilot burner body (210) in a detachable structure by screw connection.

[0055] The above protrusion (120) is formed integrally with the joint (110) and is inserted into the inside of the tip of the pilot burner body (210). It has a cylindrical structure with a closed end located inside the pilot burner body (210) and is formed to protrude from the joint (110). At this time, the outer diameter of the protrusion (110) is smaller than the inner diameter of the tip of the pilot burner body (210) so that the outer circumference of the protrusion (120) is spaced apart from the inner circumference of the tip of the pilot burner body (210). Accordingly, an annular flow path (W) extending in the axial direction (D1) of the pilot burner body (210) is formed between the protrusion (120) and the pilot burner body (210).

[0056] In this way, the protrusion (120) formed integrally with the joint (110) is formed to have a relatively smaller outer diameter than the joint (110). As a result, the combustion nozzle (10) formed by integrating the joint (110) and the protrusion (120) having different outer diameters has a two-stage structure of a small-diameter portion (protrusion) and a large-diameter portion (joint), and when coupled to the tip of the pilot burner body (210), the outer end of the annular passage (W) formed between the protrusion (120) and the pilot burner body (210) is closed by the joint (110). Accordingly, the gas mixture flowing into the annular passage (W) from the pilot burner body (210) does not flow out from the annular passage (W), but is dispersed inside the annular passage (W) and can flow into the injection hole (140) formed around the protrusion (120).

[0057] Meanwhile, a conical throttle part (150) protruding inwardly of the pilot burner body (210) is formed at the end of the protrusion (120), and an ignition chamber (160) is formed inside the combustion nozzle (10) that extends in the axial direction (D1) from the end surface of the protrusion (120) and penetrates the joint part (110) to be exposed to the outside.

[0058] The above-mentioned throttle (150) is positioned on the outer side of the end face of the protrusion (120) so as to face the gas mixture flowing in the direction of the combustion nozzle (10) inside the pilot burner body (210), and is formed in a cone shape so as to protrude in the direction facing the gas mixture. Accordingly, the gas mixture naturally flows in the annular flow path (W) while being dispersed in all directions along the surface of the throttle (150), thereby preventing pressure loss of the gas mixture.

[0059] The above ignition chamber (160) is a space formed inside the combustion nozzle (10) by connecting the internal space of the protrusion (120) and the internal space of the coupling portion (110). In FIG. 5, the ignition chamber (160) is illustrated as having a two-stage structure in which the inner diameters of the protrusion (120) and the coupling portion (110) are different from each other. However, the ignition chamber (160) may have a constant inner diameter by having the inner diameters of the protrusion (120) and the coupling portion (110) the same. In order to improve flame stability through the smooth formation of negative velocity (NV) that acts in the opposite direction to the flame ejection direction, the ignition chamber (160) is formed to have a depth (L) that is 5 to 10 times the radius (r).

[0060] At this time, if the ignition chamber (160) has a depth (L) less than 5 times the radius (r), there is a problem that the flame stability is lowered because the negative velocity is not smoothly formed, and if the depth (L) of the ignition chamber (160) exceeds 10 times the radius (r), the area of ​​the overheated part due to the flame increases, and the surface temperature of the outer wall of the transfer pipe (213) increases, so there are problems such as an additional cooling device being required to prevent damage to the material. Therefore, it is preferable that the ignition chamber (160) be formed to have a depth (L) that is 5 to 10 times the radius (r).

[0061] The above ignition rod insertion hole (130) is a hole that allows the end of the ignition rod (222) extending in the axial direction (D1) inside the pilot burner body (210) to penetrate the closed end surface of the protrusion (120) and be positioned inside the ignition chamber (160), and is formed to penetrate the center of the closed end surface of the protrusion (120) in the axial direction (D1). Of course, when the throttle (150) is formed at the end of the protrusion (120), the ignition rod insertion hole (130) also penetrates the throttle (150).

[0062] The above injection hole (140) is a hole that penetrates the side wall of the protrusion (120) so that the gas mixture of the annular path (W) is injected into the ignition chamber (160). It extends in the tangential direction of the inner wall of the ignition chamber (160) so that a swirling flow can be formed by the gas mixture injected into the ignition chamber (160), and is formed so as to inject the gas mixture around the end of the ignition rod (222) located in the ignition chamber (160). As shown in FIG. 4a, the injection hole (140) may be formed as a hole having an overall constant inner diameter, or as shown in FIG. 4b, it may be formed as an orifice structure so as to increase the flow rate of the gas mixture injected into the ignition chamber (160) through a partial reduction in the inner diameter.

[0063] Such an injection hole (140) may be formed in one or two pieces, and the two injection holes (140) are formed to have a point-symmetrical structure based on the center point of the protrusion (120), so that the mixed gas can be injected into the ignition chamber (160) from different positions.

[0064] Meanwhile, the ratio (D / r) of the diameter (D) of the injection hole (140) and the radius (r) of the ignition chamber (160) is optimized so that the swirling flow formed inside the ignition chamber (160) by the mixed gas injected into the ignition chamber (160) can form a strong swirling flow having a swirl number in the range of 3.0 to 6.0.

[0065] That is, as shown in the graph of FIG. 6, which shows the swirl number according to the change in the number of injection holes (140) and the change in the ratio (D / r) of the diameter (D) of the injection hole (140) and the radius (r) of the ignition chamber (160), in order to implement the swirl number targeted by the present invention, one or two injection holes (140) must be formed in the protrusion (120), and when one injection hole (140) is formed in the protrusion (120), the ratio (D / r) of the diameter (D) of the injection hole (140) and the radius (r) of the ignition chamber (160) is preferably set within the range of 0.475 to 0.575, and when two injection holes (140) are formed in the protrusion (120), the ratio (D / r) of the diameter (D) of the injection hole (140) and the radius (r) of the ignition chamber (160) is preferably set within the range of 0.4 to 0.475.

[0066]

[0067] As illustrated in FIG. 7, a pilot burner (20) for ammonia fuel according to one embodiment of the present invention includes a pilot burner body (210), a spark igniter (220), and a combustion nozzle (10).

[0068] The above pilot burner body (210) includes an input block (211) in which a fuel input portion (211a) and an oxidizer input portion (211b) are formed, a support block (212) integrally formed on one side of the input block (211) to support a spark igniter (220), and a cylindrical transfer pipe (213) extending in the axial direction (D1) from the support block (212), and a combustion nozzle (10) is installed at the end of the transfer pipe (213). Accordingly, ammonia gas introduced through the fuel input portion (211a) and air introduced through the oxidizer input portion (211b) are supplied from the input block (211) to the combustion nozzle (10) via the support block (212) and the transfer pipe (213), and the ammonia gas and the air are mixed with each other during the flow process to form a mixed gas.

[0069] Meanwhile, inside the end of the above-mentioned transfer pipe (213), a screw thread (213a) corresponding to the screw thread (111) formed in the connecting portion (110) of the combustion nozzle (10) is formed on the inner surface, so that the combustion nozzle (10) is screw-connected to the end of the transfer pipe (213).

[0070] The above spark igniter (220) includes a spark plug (221) mounted on a support block (212) and an ignition rod (222) extending from the spark plug (221) to the inside of the ignition chamber (160) via a transfer pipe (213). This spark igniter (220) can generate an electric spark inside the ignition chamber (160) to ignite a gas mixture injected into the ignition chamber (160).

[0071] The above combustion nozzle (10) is connected to the end of the transfer pipe (213), and the combustion nozzle (10) connected to the transfer pipe (213) moves in the axial direction (D1) through the transfer pipe (213) and injects the mixed gas supplied to the annular path (W) through the injection hole (140) in the tangential direction (D2) inside the ignition chamber (160), thereby generating a strong swirling flow inside the ignition chamber (160).

[0072] As shown in Fig. 4a, in order to prevent damage to the combustion nozzle (10) due to the high-temperature flame formed in the ignition chamber (160), the combustion nozzle (10) is formed entirely of stainless steel, or a coating layer (161) made of one of a ceramic tube, a quartz tube, or a ceramic coating is provided on the wall surface of the ignition chamber (160), thereby improving durability against flames.

[0073] Hereinafter, the process of igniting ammonia fuel and forming and stabilizing a flame in the ammonia fuel pilot burner (20) of the present invention configured as described above will be described.

[0074] As illustrated in Fig. 5, a mixture formed by mixing ammonia gas and air flowing into the pilot burner body (210) flows in the axial direction (D1) through a transfer pipe (213) and flows into an annular passage (W), and the mixture flowing into the annular passage (W) is injected into the ignition chamber (160) through an injection hole (140) formed in a combustion nozzle (10). At this time, the mixture is injected in a tangential direction (D2) inside the ignition chamber (160), so a swirling flow is generated inside the ignition chamber (160) due to the flow of the mixed gas flowing into it. Meanwhile, the combustion nozzle (10) of the present invention does not generate a swirling flow by interfering with the flowing mixed gas and changing the direction of the mixed gas, but generates a swirling flow by directly injecting the mixed gas into the ignition chamber (160) through an injection hole (140) extending in the tangential direction (D2) inside the ignition chamber (160), thereby generating a strong swirling flow inside the ignition chamber (160).

[0075] In this way, the swirling flow generated inside the ignition chamber (160) extends in the axial direction (D1), and at the center of the swirling flow extending in the axial direction (D1), a negative velocity (NV) acting in the opposite direction to the direction in which the flame is ejected is formed. The negative velocity (NV) formed in this way slows down the flow velocity of the gas mixture flowing toward the exit end of the ignition chamber (160) and concentrates the gas mixture around the ignition rod (222), thereby inducing smooth ignition of the gas mixture and stabilizing the flame.

[0076] That is, if the combustion speed is generally lower than the fuel flow rate, the flame is blown out and extinguished, and if the continuous speed is higher than the fuel flow rate, the flame is stabilized.

[0077] Meanwhile, considering that the combustion speed of ammonia is very low and it is difficult to stabilize the flame even if the flow rate of the mixed gas is lowered, the present invention forms a negative velocity (NV) that generates a strong swirling flow inside the ignition chamber (160) to slow down the flow rate of the mixed gas, thereby promoting smooth ignition and stabilization of the flame.

[0078] Therefore, the pilot burner (20) for ammonia fuel according to the present invention can ignite a mixture of pure ammonia gas and air at room temperature without the aid of other fuels or electric energy, and can also stabilize the flame.

[0079] As illustrated in FIG. 8, an ammonia combustor according to one embodiment of the present invention may be configured to include a combustor body (310) through which ammonia fuel and an oxidizer are supplied internally and which includes an outlet end (311) through which a flame is ejected, and an ammonia fuel pilot burner (20) mounted on the combustor body (310). At this time, the structure of the combustor body (310) is not particularly limited and may have various structures, and the ammonia fuel pilot burner (20) may be mounted on the combustor body (310) so as to be positioned around an injection position of the ammonia fuel.

[0080]

[0081] It will be understood by those skilled in the art that the ammonia combustion nozzle according to the present invention described above, the ammonia fuel pilot burner including the same, and the ammonia combustor including the same can be implemented in other specific forms without changing the technical idea or essential features of the present invention.

[0082] Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive, and the scope of the present invention is indicated by the claims described below rather than the detailed description described above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

[0083] The present invention provides an ammonia combustion nozzle capable of stably initially igniting ammonia fuel without inputting other fuel or electric energy, a pilot burner including the same, and an ammonia combustor including the same, the nozzle including: a coupling portion (110) coupled to a pilot burner body (210); a protrusion (120) inserted into the interior of the pilot burner body (210) to form an annular passage (W) extending in the axial direction (D1) of the pilot burner body (210) between the nozzle and the pilot burner body (210); an ignition rod insertion hole (130) formed by penetrating a closed end surface of the protrusion (120); and one or more injection holes (140) formed in the protrusion (120) to inject a gas mixture flowing into the annular passage (W) into the interior of the protrusion (120) to form a swirling flow inside the protrusion (120).

[0084] The mixed gas supplied to the combustion nozzle is ejected in the tangential direction of the inner surface of the combustion nozzle to form a strong swirling flow, and at the same time, a strong countercurrent is formed in the axial direction of the combustion nozzle. The countercurrent formed in the combustion nozzle in this way causes the ammonia fuel with a slow combustion speed to remain upstream of the combustion nozzle, i.e., around the ignition rod, so that the ammonia fuel can be stably ignited without inputting other fuel or electric energy, and the flame stability can be improved, and therefore, there is potential for industrial application.

Claims

1. A joint (110) coupled to a pilot burner body (210); A protrusion (120) inserted into the interior of the pilot burner body (210) to form an annular flow path (W) extending in the axial direction (D1) of the pilot burner body (210) between the pilot burner body (210); An ignition rod insertion hole (130) formed by penetrating the closed end surface of the above protrusion (120); and An ammonia combustion nozzle comprising one or more injection holes (140) formed in a protrusion (120) to inject a mixed gas flowing into the above-mentioned annular flow path (W) into the inside of the protrusion (120) to form a swirling flow inside the protrusion (120).

2. In paragraph 1, An ammonia combustion nozzle, wherein the above-mentioned connecting portion (110) is connected to the tip of the pilot burner body (210), and the protrusion (120) is integrally formed with the connecting portion (110) so as to protrude from the connecting portion (110) and be inserted into the interior of the pilot burner body (210).

3. In paragraph 2, An ammonia combustion nozzle, wherein the above protrusion (120) has an outer diameter smaller than that of the connecting portion (110).

4. In paragraph 1, An ammonia combustion nozzle in which screw threads (111, 213a) are formed on the outer surface of the above-mentioned joint (110) and the inner surface of the pilot burner body (210) so that they can be interlocked and combined with each other.

5. In paragraph 1, The above injection hole (140) is a nozzle for combustion of ammonium oxide, which penetrates the protrusion (120) to connect the inner and outer surfaces of the protrusion (120), but extends in the tangential direction of the inner surface.

6. In paragraph 1, An ammonia combustion nozzle in which a conical axle (150) is formed protrudingly at the end of the above protrusion (120).

7. In paragraph 1, An ammonia combustion nozzle, wherein one injection hole (140) is formed in the above protrusion (120), and the ratio (D / r) of the diameter (D) of the injection hole (140) and the radius (r) of the ignition chamber (160) is 0.475 to 0.

575.

8. In paragraph 1, An ammonia combustion nozzle in which two injection holes (140) are formed in the above protrusion (120), and the ratio (D / r) of the diameter (D) of the injection holes (140) and the radius (r) of the ignition chamber (160) is 0.400 to 0.

475.

9. In paragraph 1, The above injection hole (140) is formed as an orifice structure to increase the flow rate of the mixed gas ejected into the protrusion (120), and is an ammonia combustion nozzle.

10. In paragraph 1, An ammonia combustion nozzle further comprising an ignition chamber (160) extending from the end face of the protrusion (120) in the axial direction (D1) of the pilot burner body (210) and penetrating the joint (110) so that a flame generated inside is ejected to the outside.

11. In paragraph 10, The above ignition chamber (160) is an ammonia combustion nozzle having a depth (L) that is more than 5 times the radius (r).

12. A pilot burner body (210) having a fuel input section (211a) and an oxidizer input section (211b), and including a cylindrical transfer pipe (213) through which a mixed gas consisting of ammonia gas and air, which are input into the fuel input section (211a) and the oxidizer input section (211b), respectively, flows; A spark igniter (220) mounted on the above pilot burner body (210) and having an ignition rod (222) extending through the interior of the transfer pipe (213); and A pilot burner for ammonia fuel, comprising an ammonia combustion nozzle (10) according to any one of claims 1 to 11, which is coupled to the end of the above-mentioned transfer pipe (213).

13. In paragraph 12, The material of the above ammonia combustion nozzle (10) is stainless steel, a pilot burner for ammonia fuel.

14. In paragraph 12, The above ammonia combustion nozzle (10) is a pilot burner for ammonia fuel, characterized in that a ceramic tube, quartz tube or ceramic coating layer (161) is formed on the inner surface.

15. A combustor body (310) including an outlet through which ammonia fuel and oxidizer are supplied internally and a flame is emitted; and An ammonia combustor comprising an ammonia fuel pilot burner (20) of claim 12, which is mounted on the combustor body (310) to ignite the ammonia fuel supplied to the combustor body (310) and maintain the flame.

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