Ammonia co-firing burner and method for manufacturing ammonia co-firing system using same

Abstract

The ammonia-mixed combustion burner (4) is installed in the combustion chamber (2) and supplies ammonia and a carbon-containing fuel into the combustion chamber (2) and burns them. The ammonia-mixed combustion burner (4) includes a carbon-containing fuel supply passage (41) that mixes the carbon-containing fuel and air and supplies the mixture into the combustion chamber (2), and an ammonia supply passage (42) that mixes the ammonia and air and supplies the mixture into the combustion chamber (2).

Description

[Technical field]

[0001] The present disclosure relates to an ammonia co-firing burner and a method for manufacturing an ammonia co-firing system using the same. [Background technology]

[0002] In order to reduce CO2 emissions from coal-fired power plants, the development of technology for co-firing ammonia and pulverized coal (hereinafter referred to as co-firing) is underway. Ammonia (NH3) is a compound of hydrogen atoms (H) and nitrogen atoms (N), and since it does not contain carbon (C) as a constituent atom, it is expected to be used as a fuel that does not emit CO2 when burned.

[0003] On the other hand, in a boiler that burns ammonia as part of the fuel, there is a concern that an increase in nitrogen oxides (NOx) associated with the combustion of ammonia will occur as a result of a part of the fuel being replaced from coal by ammonia.Patent Document 1 discloses that in an ammonia co-firing system in which an ammonia burner and a pulverized coal burner are provided in different positions, the generation of NOx can be suppressed by providing a control device that controls the supply amounts of ammonia fuel, pulverized coal, and combustion air. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-39881 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, when ammonia and a carbon-containing fuel are mixed and burned in the same space, the combustion of the ammonia and the carbon-containing fuel competes with each other. Therefore, the optimal amount of oxygen for each combustion is not supplied, and NO X There is a problem that this leads to an increase in emissions and unburned fuel in ash.

[0006] Therefore, the present disclosure provides a method for premixing ammonia and a carbon-containing fuel with air before combustion, supplying them to a combustion chamber, and burning them in separate spaces to produce NO X The object of the present invention is to provide an ammonia co-firing burner with reduced emissions, and a method for manufacturing an ammonia co-firing system using the same. [Means for solving the problem]

[0007] The ammonia co-fuel burner according to the present disclosure is an ammonia co-fuel burner that is installed in a combustion chamber and supplies ammonia and a carbon-containing fuel into the combustion chamber to combust them, and includes a carbon-containing fuel supply flow path that mixes the carbon-containing fuel and air and supplies the mixture into the combustion chamber, and an ammonia supply flow path that mixes the ammonia and air and supplies the mixture into the combustion chamber.

[0008] The carbon-containing fuel supply passage may be a first injection nozzle that mixes the carbon-containing fuel and air and injects the mixture into the combustion chamber, and the ammonia supply passage may be a second injection nozzle that mixes the ammonia and air and injects the mixture into the combustion chamber.

[0009] The first injection nozzle is formed to surround the second injection nozzle and has a double cylindrical shape arranged concentrically with the second injection nozzle, the injection direction of the first injection nozzle and the injection direction of the second injection nozzle are oriented in the same direction as the nozzle axis, and the first injection nozzle may be provided with an air supply flow passage that supplies air into the combustion chamber through a swirler.

[0010] The second injection nozzle is formed to surround the first injection nozzle and has a double cylindrical shape arranged concentrically with the first injection nozzle, the injection direction of the first injection nozzle and the injection direction of the second injection nozzle are oriented in the same direction as the nozzle axis, and the second injection nozzle may be provided with an air supply flow passage that supplies air into the combustion chamber through a swirler.

[0011] When ammonia and air are mixed in the ammonia supply channel, the equivalence ratio of ammonia to air may be 1.0 or more.

[0012] The manufacturing method of an ammonia co-combustion system according to the present disclosure is a manufacturing method of an ammonia co-combustion system having a combustion chamber and an ammonia co-combustion burner which supplies ammonia and a carbon-containing fuel into the combustion chamber and combusts them, and the burner is equipped with a first injection nozzle which mixes the carbon-containing fuel and air and injects the mixture into the combustion chamber, and is modified by connecting a connection path to an air flow path which supplies air into the combustion chamber, and an ammonia supply flow path which mixes ammonia and air and supplies the mixture into the combustion chamber, and a swirler is installed in the ammonia supply flow path.

[0013] The manufacturing method of an ammonia co-combustion system according to the present disclosure is a manufacturing method of an ammonia co-combustion system having a combustion chamber and an ammonia co-combustion burner which supplies ammonia and a carbon-containing fuel into the combustion chamber and combusts them, wherein a first injection nozzle which mixes the carbon-containing fuel and air and injects the mixture into the combustion chamber is formed to surround the ammonia injection nozzle which injects ammonia into the combustion chamber, and the burner has a double-cylinder shape which is concentric with the ammonia injection nozzle. The burner is modified by connecting a connection path to an air supply flow path which supplies air into the combustion chamber, and an ammonia supply flow path which mixes ammonia and air and supplies the mixture into the combustion chamber, and a swirler is installed in the ammonia supply flow path.

[0014] The air supply passage may be divided into a plurality of air supply passages, and may be modified by connecting a connecting path to at least a portion of the plurality of air supply passages to provide an ammonia supply passage that mixes ammonia and air and supplies the mixture to the combustion chamber.

[0015] The manufacturing method of an ammonia co-combustion system according to the present disclosure is a manufacturing method of an ammonia co-combustion system having a combustion chamber and an ammonia co-combustion burner which supplies ammonia and a carbon-containing fuel into the combustion chamber and combusts them, wherein a first injection nozzle which mixes the carbon-containing fuel and air and injects them into the combustion chamber is formed to surround the ammonia injection nozzle which injects ammonia into the combustion chamber and the burner has a double-cylinder shape concentrically arranged with the ammonia injection nozzle, and is modified by connecting a connection path to the ammonia injection nozzle, and a second injection nozzle which mixes ammonia and air and supplies the mixture into the combustion chamber is installed.

[0016] The injection direction of the first injection nozzle and the injection direction of the second injection nozzle may be oriented in the same direction as the nozzle axis, and an air supply flow passage may be provided to supply air through a swirler into the combustion chamber.

[0017] The manufacturing method of an ammonia co-combustion system according to the present disclosure is a manufacturing method of an ammonia co-combustion system having a combustion chamber and an ammonia co-combustion burner which supplies ammonia and a carbon-containing fuel into the combustion chamber and combusts them, and the burner is equipped with a first injection nozzle which mixes the carbon-containing fuel and air and injects the mixture into the combustion chamber, and is modified by installing a second injection nozzle which mixes ammonia and air and injects the mixture into the combustion chamber outside the first injection nozzle.

[0018] The second injection nozzle may be formed to surround the first injection nozzle and have a double-cylinder shape arranged concentrically with the first injection nozzle, the injection direction of the first injection nozzle and the injection direction of the second injection nozzle may be oriented in the same direction as the nozzle axis, and an air supply passage may be provided to supply air into the combustion chamber through a swirler. Effect of the Invention

[0019] According to the present disclosure, ammonia and a carbon-containing fuel are premixed with air before combustion and supplied to a combustion chamber, and then combusted in separate spaces to produce NO X It is possible to provide an ammonia co-firing burner with reduced emissions, and a method for manufacturing an ammonia co-firing system using the same. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a main part of a boiler provided in an ammonia co-firing system according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing an outline of the ammonia-mixed combustion burner according to the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing an outline of an ammonia-mixed combustion burner according to the second embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing an outline of an ammonia-mixed combustion burner according to the third embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing an outline of an ammonia-mixed combustion burner according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, some exemplary embodiments will be described with reference to the drawings. Note that the dimensional ratios of the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0022] [First embodiment] Fig. 1 shows a boiler 1 provided in an ammonia co-firing system according to the first embodiment. As shown in Fig. 1, the boiler 1 includes a combustion chamber 2, a flue 3, an ammonia co-firing burner 4, a two-stage combustion air supply unit 5, an ammonia supply unit 6, a carbon-containing fuel supply unit 7, and an air supply unit 8.

[0023] The combustion chamber 2 is a furnace body that is composed of a vertical, cylindrical furnace wall and burns ammonia and a carbon-containing fuel to generate combustion heat. In the combustion chamber 2, high-temperature combustion gas is generated by burning the fuel. In addition, an exhaust port 2a is provided at the bottom of the combustion chamber 2 to discharge ash generated by the combustion of the fuel to the outside.

[0024] The flue 3 is connected to the upper part of the combustion chamber 2 and guides the combustion gas generated in the combustion chamber 2 to the outside as exhaust gas. Such a flue 3 includes a horizontal flue 3a extending horizontally from the upper part of the combustion chamber 2 and a rear flue 3b extending downward from the end of the horizontal flue 3a.

[0025] The boiler 1 is equipped with a superheater (not shown) that is installed at the top of the combustion chamber 2 or the like. The superheater generates steam by heat exchange between the combustion heat generated in the combustion chamber 2 and water. The boiler 1 also includes a reheater, a coal economizer, an air preheater, etc. (none of which are shown) as necessary.

[0026] The ammonia-mixed combustion burner 4 is disposed on the wall of the lower part of the combustion chamber 2. A plurality of ammonia-mixed combustion burners 4 may be disposed in the circumferential direction of the combustion chamber 2, or a plurality of ammonia-mixed combustion burners 4 may be disposed in the height direction of the combustion chamber 2. These ammonia-mixed combustion burners 4 are disposed two-dimensionally and facing each other at the lower part of the combustion chamber 2, and inject and burn fuel. All of these ammonia-mixed combustion burners 4 are composite burners capable of injecting ammonia and carbon-containing fuel as fuel into the combustion chamber 2. The combustion chamber 2 is provided with an ignition device (not shown) that ignites the ammonia and carbon-containing fuel injected from the ammonia-mixed combustion burner 4. The boiler 1 also has an air supply unit 8 that supplies combustion air to the ammonia-mixed combustion burner 4. The ammonia and carbon-containing fuel injected from the ammonia-mixed combustion burner 4 into the combustion chamber 2 together with the combustion air is ignited and burned by the action of the above-mentioned ignition device.

[0027] It is not necessary that all the burners installed in the boiler 1 are ammonia-mixed combustion burners 4. For example, the boiler 1 may be provided with a coal-only combustion burner or an ammonia-only combustion burner in addition to the ammonia-mixed combustion burner 4.

[0028] The two-stage combustion air supply unit 5 is connected to the combustion chamber 2 above the ammonia-mixed combustion burner 4, and supplies air for two-stage combustion to the inside of the combustion chamber 2. By supplying air for two-stage combustion by such two-stage combustion air supply unit 5, the unburned fuel combusted by the ammonia-mixed combustion burner 4 is combusted by the two-stage combustion air, thereby improving the heat absorption performance of the boiler 1 and reducing the unburned fuel contained in the exhaust gas. Then, the combustion gas generated by burning the fuel moves from the lower part to the upper part of the combustion chamber 2 and is guided to the outside through the flue 3.

[0029] The carbon-containing fuel supplied to the ammonia co-firing burner 4 includes fossil fuels, biomass fuels, and synthetic fuels. Examples of fossil fuels include methane, ethane, propane, butane, liquefied natural gas, kerosene, heavy oil, light oil, gasoline, and coal such as pulverized coal. Pulverized coal is coal that has been pulverized to a size of about several micrometers, and is generally used as fuel for boilers.

[0030] On the other hand, examples of biomass fuels include crushed materials produced by crushing woody biomass such as thinned wood, lumber scraps, and pruned branches with a crusher, sawdust, and pellets produced from woody biomass. Synthetic fuels may be hydrocarbons produced by methanation or the Fischer-Tropsch reaction. Carbon-containing fuels can also be used in combination. For example, a mixed powder of pulverized coal and biomass fuel powder can be supplied to the ammonia-mixed combustion burner 4 by air transportation.

[0031] Ammonia (NH3) is a compound of hydrogen atoms (H) and nitrogen atoms (N), and does not contain carbon (C) as a constituent atom, so it is expected to be used as a fuel that does not emit CO2 when burned. In order to reduce CO2 emissions, technological development is underway to introduce an ammonia co-firing system in which ammonia and coal are mixed and burned by modifying part of existing facilities such as coal-fired power plants. On the other hand, there is concern that the increase in nitrogen oxides (NOx) associated with the combustion of ammonia will occur as a result of replacing part of the fuel from coal with ammonia. For this reason, in this embodiment, NO X To provide an ammonia co-firing burner with reduced emissions.

[0032] The ammonia supply unit 6 includes an ammonia supply source 6a, a fuel ammonia supply unit 6b, and an ammonia supply control device 6c. The ammonia supply source 6a is composed of a tank for storing ammonia. The ammonia supply source 6a does not necessarily have to be a component of the ammonia supply unit 6. In other words, the ammonia supply unit 6 may take in ammonia from the ammonia supply source 6a installed externally.

[0033] The fuel ammonia supply unit 6b includes a fuel ammonia supply pipe 6b1 that connects the ammonia supply source 6a and the ammonia-mixed combustion burner 4, and a flow rate control valve 6b2 that is installed in the middle of the fuel ammonia supply pipe 6b1. The fuel ammonia supply pipe 6b1 is a pipe that guides ammonia supplied from the ammonia supply source 6a to the ammonia-mixed combustion burner 4, and supplies ammonia to the inside of the combustion chamber 2 via the ammonia supply passage 42. The flow rate control valve 6b2 is a valve that adjusts the flow rate of ammonia supplied from the ammonia supply source 6a to the fuel ammonia supply pipe 6b1.

[0034] The ammonia supply controller 6c controls the flow rate control valve 6b2 to adjust the aperture of the flow rate control valve 6b2. The ammonia supply controller 6c adjusts the aperture of the flow rate control valve 6b2 based on an external command or the like to adjust the flow rate of ammonia taken in from the ammonia supply source 6a.

[0035] The carbon-containing fuel supply unit 7 is connected to the ammonia-mixed combustion burner 4 and supplies the carbon-containing fuel to the inside of the combustion chamber 2 via the carbon-containing fuel supply passage 41 .

[0036] When the carbon-containing fuel is pulverized coal, coal is pulverized to produce pulverized coal and the pulverized coal is supplied to the ammonia-mixed combustion burner 4. The carbon-containing fuel supply unit 7 includes, for example, a mill that pulverizes coal to a particle size of about several micrometers to produce pulverized coal, and a coal feeder that supplies the pulverized coal produced by the mill to the ammonia-mixed combustion burner 4. The carbon-containing fuel supply unit 7 may also be configured to supply the pulverized coal directly from the mill to the ammonia-mixed combustion burner 4 without including a coal feeder.

[0037] The air supply unit 8 is connected to the middle of the pipe connecting the carbon-containing fuel supply unit 7 and the ammonia-mixed combustion burner 4, and supplies air for combustion to the carbon-containing fuel. The air supplied to the carbon-containing fuel is heated by a heating device (not shown) provided upstream of the air supply unit 8, and has a temperature higher than room temperature. The carbon-containing fuel supply passage 41 of the ammonia-mixed combustion burner 4 premixes the carbon-containing fuel and air before combustion and supplies the premixed fuel to the combustion chamber 2.

[0038] The air supply unit 8 is connected to the middle of the fuel ammonia supply pipe 6b1 and supplies air for combustion to the ammonia. The air supplied to the ammonia is heated by a heating device (not shown) provided upstream of the air supply unit 8 and has a temperature higher than room temperature. The ammonia supply flow path 42 of the ammonia-mixed combustion burner 4 premixes ammonia and air before combustion and supplies the mixture into the combustion chamber 2.

[0039] As described above, by premixing ammonia and carbon-containing fuel with air before combustion and adjusting the optimal conditions for combustion, the optimal amount of oxygen is supplied for each combustion, resulting in NO X It is possible to suppress an increase in emissions and unburned fuel in ash. When ammonia and air are mixed in the ammonia supply passage 42, the equivalence ratio between ammonia and air is preferably 1.0 or more, and more preferably 1.1 to 2.0. The equivalence ratio indicates the ratio of the amount of fuel actually input to the amount of fuel in the theoretical mixture when combustion is performed. An equivalence ratio greater than 1.0 indicates an excessively rich fuel state.

[0040] The ammonia-mixed combustion burner 4 is an ammonia-mixed combustion burner that is installed in the combustion chamber 2 and supplies and combusts ammonia and a carbon-containing fuel into the combustion chamber 2. The ammonia-mixed combustion burner 4 includes a carbon-containing fuel supply passage 41 that mixes the carbon-containing fuel and air and supplies the mixture into the combustion chamber 2, and an ammonia supply passage 42 that mixes the ammonia and air and supplies the mixture into the combustion chamber 2.

[0041] The ammonia-mixed combustion burner 4a according to the first embodiment will be described with reference to Fig. 2. The carbon-containing fuel supply passage 41 in the ammonia-mixed combustion burner 4a is a first injection nozzle 41a that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber 2. The ammonia supply passage 42 in the ammonia-mixed combustion burner 4a is a second injection nozzle 42a that mixes ammonia and air and injects the mixture into the combustion chamber 2. That is, the ammonia-mixed combustion burner 4a according to the first embodiment is equipped with the first injection nozzle 41a and the second injection nozzle 42a.

[0042] The first injection nozzle 41a may be formed to surround the second injection nozzle 42a and may have a double cylindrical shape provided concentrically with the second injection nozzle 42a. That is, the first injection nozzle 41a may be an outer cylindrical part and the second injection nozzle 42a may be an inner cylindrical part, and the double cylindrical shape may be centered on the nozzle axis L of the second injection nozzle 42a. In addition, the injection direction of the first injection nozzle 41a and the injection direction of the second injection nozzle 42a may be oriented in the same direction as the nozzle axis L.

[0043] On the other hand, the ammonia-mixed combustion burner 4a is provided with a secondary air supply passage 43a that supplies air through a swirler 45a into the combustion chamber 2. The secondary air supply passage 43a is disposed so as to surround the outside of the nozzle of the first injection nozzle 41a.

[0044] The air supply unit 8 is connected to the secondary air supply passage 43a and supplies secondary air for combustion from the radially outer side to the flame. The secondary air supplied to the combustion chamber 2 via the secondary air supply passage 43a is heated by a heating device (not shown) provided upstream of the air supply unit 8 and has a temperature higher than room temperature.

[0045] The swirler 45a is provided upstream of the secondary air supply passage 43a. The swirler 45a has a plurality of blades arranged radially and a driving device such as a motor for rotating the plurality of blades. The rotation of the plurality of blades of the swirler 45a finely adjusts the swirling force of the secondary air flowing into the secondary air supply passage 43a. The swirling force of the secondary air forms an internal circulating flow of fuel and air in the combustion chamber 2. The internal circulating flow is a circulating flow that flows from the outside toward the nozzle axis L in the combustion chamber 2, as shown by the dotted lines and arrows in FIG. 2.

[0046] In the ammonia-mixed combustion burner 4a, ammonia and air are injected from the second injection nozzle 42a, and carbon-containing fuel and air are injected from the first injection nozzle 41a. Furthermore, in the ammonia-mixed combustion burner 4a, secondary air for combustion is supplied and combusted, so that flames F1 and F2 are formed in front of the ammonia-mixed combustion burner 4a, as shown in FIG.

[0047] The flame F1 is a carbon-containing fuel flame that is burned by injecting a carbon-containing fuel and air from the first injection nozzle 41a. As described above, the flame F1 is formed toward the outside in the radial direction of the nozzle axis L due to the internal circulating flow in the combustion chamber 2 that is generated by the swirling force of the secondary air.

[0048] On the other hand, the flame F2 is an ammonia flame produced by combustion of ammonia and air injected from the second injection nozzle 42a. The flame F2 is formed in a linear direction along the nozzle axis L. When the flames F1 and F2 are formed in this manner, the outer edge region of the flame F1 (the region radially outward from the nozzle axis L) and the tip region of the flame F2 become low oxygen concentration regions where the oxygen concentration is low.

[0049] Ammonia and air are mixed and supplied into the combustion chamber 2 from the second injection nozzle 42a of the ammonia-mixed combustion burner 4a, but the ammonia is injected into the low oxygen concentration region where the oxygen concentration is low. When ammonia is burned in an oxygen-rich region, the nitrogen contained in the ammonia is likely to combine with the oxygen to generate NOx, but when ammonia is burned in the low oxygen concentration region, the nitrogen contained in the ammonia combines with itself to form nitrogen gas (N2). Therefore, the ammonia-mixed combustion burner 4a makes it possible to suppress an increase in NOx.

[0050] In this way, the ammonia-mixed combustion burner 4a according to the first embodiment includes a first injection nozzle 41a that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber 2, and a second injection nozzle 42a that mixes ammonia and air and injects the mixture into the combustion chamber 2. Therefore, during mixed combustion, ammonia and carbon-containing fuel are burned in separate spaces, and there is no competition between the combustion of ammonia and the combustion of carbon-containing fuel. Furthermore, by premixing a portion of the air with ammonia before combustion and adjusting the optimal conditions for combustion, an optimal amount of oxygen is supplied for each combustion, and NO X It is possible to suppress the increase in emissions and unburned fuel in ash.

[0051] [Second embodiment] Next, an ammonia-mixed combustion burner according to the second embodiment will be described. The boiler 1 provided in the ammonia-mixed combustion system shown in Fig. 1 is the same as that of the first embodiment except for the ammonia-mixed combustion burner 4, and therefore the description thereof will be omitted. In the description of the second embodiment, the description of the same parts as those of the first embodiment will be omitted or simplified.

[0052] The ammonia-mixed combustion burner 4b according to the second embodiment will be described with reference to Fig. 3. The carbon-containing fuel supply passage 41 in the ammonia-mixed combustion burner 4b is a first injection nozzle 41b that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber 2. The ammonia supply passage 42 in the ammonia-mixed combustion burner 4b is a second injection nozzle 42b that mixes ammonia and air and injects the mixture into the combustion chamber 2. That is, the ammonia-mixed combustion burner 4b according to the second embodiment includes a first injection nozzle 41b and a second injection nozzle 42b.

[0053] The second jet nozzle 42b may be formed to surround the first jet nozzle 41b and may have a double-cylinder shape provided concentrically with the first jet nozzle 41b. That is, the second jet nozzle 42b may be an outer cylinder and the first jet nozzle 41b may be an inner cylinder, with the nozzle axis L of the first jet nozzle 41b as the center. In addition, the jet direction of the first jet nozzle 41b and the jet direction of the second jet nozzle 42b may be oriented in the same direction as the nozzle axis L.

[0054] On the other hand, the ammonia-mixed combustion burner 4b includes a secondary air supply passage 43b that supplies air through a swirler 45b into the combustion chamber 2. The secondary air supply passage 43b is disposed so as to surround the outside of the nozzle of the second injection nozzle 42b.

[0055] The air supply unit 8 is connected to the secondary air supply passage 43b and supplies secondary air for combustion from the radially outer side to the flame. The secondary air supplied to the combustion chamber 2 via the secondary air supply passage 43b is heated by a heating device (not shown) provided upstream of the air supply unit 8 and has a temperature higher than room temperature.

[0056] The swirler 45b has the same function as the swirler 45a of the first embodiment, and is provided upstream of the secondary air supply passage 43b to finely adjust the swirling force of the secondary air flowing into the secondary air supply passage 43b. In the ammonia-mixed combustion burner 4b, the carbon-containing fuel and air are injected from the first injection nozzle 41b, and the ammonia and air are injected from the second injection nozzle 42b. Furthermore, in the ammonia-mixed combustion burner 4b, secondary air for combustion is supplied and combusted, and flames F1 and F2 are formed in front of the ammonia-mixed combustion burner 4b as shown in FIG.

[0057] The flame F2 is an ammonia flame burned by injecting ammonia and air from the second injection nozzle 42b. The flame F2 is formed toward the radially outward direction of the nozzle axis L by an internal circulating flow (dotted lines and arrows in FIG. 3) in the combustion chamber 2 generated by the swirling force of the secondary air. On the other hand, the flame F1 is a carbon-containing fuel flame burned by injecting a carbon-containing fuel and air from the first injection nozzle 41b, and is formed in a linear direction along the nozzle axis L. When the flames F1 and F2 are formed in this manner, the outer edge region of the flame F2 (the region radially outward of the nozzle axis L) and the tip region of the flame F1 become oxygen concentration reduced regions where the oxygen concentration is low.

[0058] Ammonia and air are mixed and supplied into the combustion chamber 2 from the second injection nozzle 42b of the ammonia-mixed combustion burner 4b, but the ammonia is injected into the low oxygen concentration region where the oxygen concentration is low. Therefore, similar to the first embodiment, the ammonia-mixed combustion burner 4b makes it possible to suppress an increase in nitrogen oxides (NOx).

[0059] In this way, the ammonia-mixed combustion burner 4b according to the second embodiment includes a first injection nozzle 41b that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber 2, and a second injection nozzle 42b that mixes ammonia and air and injects the mixture into the combustion chamber 2. Therefore, during mixed combustion, ammonia and carbon-containing fuel are burned in separate spaces, and there is no competition between the combustion of ammonia and the combustion of carbon-containing fuel. Furthermore, by premixing a portion of the air with ammonia before combustion and adjusting the optimal conditions for combustion, an optimal amount of oxygen is supplied for each combustion, and NO X It is possible to suppress the increase in emissions and unburned fuel in ash.

[0060] [Third embodiment] Next, an ammonia-mixed combustion burner according to the third embodiment will be described. The boiler 1 provided in the ammonia-mixed combustion system shown in Fig. 1 is the same as the first embodiment except for the ammonia-mixed combustion burner 4, so the description thereof will be omitted. In the description of the third embodiment, the description of the same parts as the above-mentioned embodiments will be omitted or simplified.

[0061] The ammonia-mixed combustion burner 4c according to the third embodiment will be described with reference to Fig. 4. The carbon-containing fuel supply passage 41 in the ammonia-mixed combustion burner 4c is a first injection nozzle 41c that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber 2. The ammonia supply passage 42 in the ammonia-mixed combustion burner 4c is an ammonia supply passage 42c that mixes ammonia and secondary air and supplies the mixture into the combustion chamber 2. That is, the ammonia-mixed combustion burner 4c according to the third embodiment includes the first injection nozzle 41c and the ammonia supply passage 42c.

[0062] The ammonia-mixed combustion burner 4c includes an air injection nozzle 46c that injects air for combustion into the combustion chamber 2. The air supply unit 8 is connected to the air injection nozzle 46c. The air injected into the combustion chamber 2 via the air injection nozzle 46c is heated by a heating device (not shown) provided upstream of the air supply unit 8, and is at a temperature higher than room temperature. The air injection nozzle 46c may be formed to surround the first injection nozzle 41c and may have a double-cylinder shape that is provided concentrically with the first injection nozzle 41c. That is, the air injection nozzle 46c may be an outer cylinder and the first injection nozzle 41c may be an inner cylinder, and the nozzle axis L of the first injection nozzle 41c may be the center. In addition, the injection direction of the first injection nozzle 41c and the injection direction of the air injection nozzle 46c may be oriented in the same direction as the nozzle axis L.

[0063] On the other hand, the ammonia-mixed combustion burner 4c includes an ammonia supply passage 42c that mixes ammonia and secondary air through a swirler 45c and supplies the mixture into the combustion chamber 2. The ammonia supply passage 42c is disposed so as to surround the outside of the nozzle of the air injection nozzle 46c.

[0064] The air supply unit 8 is connected to the ammonia supply passage 42c and supplies secondary air for combustion to the flame from the radially outer side. The secondary air supplied to the combustion chamber 2 via the ammonia supply passage 42c is heated by a heating device (not shown) provided upstream of the air supply unit 8 and has a temperature higher than room temperature.

[0065] The swirler 45c has the same function as the swirler 45a of the first embodiment, and is provided upstream of the ammonia supply passage 42c to finely adjust the swirling force of the secondary air flowing into the ammonia supply passage 42c. In the ammonia-mixed combustion burner 4c, the carbon-containing fuel and air are injected from the first injection nozzle 41c, and the air for combustion is injected. Furthermore, in the ammonia-mixed combustion burner 4c, ammonia and secondary air are supplied from the ammonia supply passage 42c, and thus flames F1 and F2 are formed in front of the ammonia-mixed combustion burner 4c as shown in FIG.

[0066] The flame F2 is an ammonia flame burned by supplying ammonia and secondary air from the ammonia supply passage 42c. The flame F2 is formed toward the radially outward direction of the nozzle axis L by an internal circulating flow (dotted lines and arrows in FIG. 4) in the combustion chamber 2 generated by the swirling force of the secondary air. On the other hand, the flame F1 is a carbon-containing fuel flame burned by injecting a carbon-containing fuel and air from the first injection nozzle 41c, and is formed in a linear direction along the nozzle axis L. When the flames F1 and F2 are formed in this manner, the outer edge region of the flame F2 (the region radially outward of the nozzle axis L) and the tip region of the flame F1 become oxygen concentration reduced regions where the oxygen concentration is low.

[0067] Ammonia and secondary air are mixed and supplied from the ammonia supply passage 42c of the ammonia-mixed combustion burner 4c into the combustion chamber 2, but the ammonia is injected into the oxygen concentration low region where the oxygen concentration is low. Therefore, similar to the first embodiment, the ammonia-mixed combustion burner 4c can suppress an increase in NOx.

[0068] In this way, the ammonia-mixed combustion burner 4c according to the third embodiment includes a first injection nozzle 41c that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber 2, and an ammonia supply passage 42c that mixes ammonia and air and supplies the mixture into the combustion chamber 2. Therefore, during the mixed combustion, ammonia and carbon-containing fuel are burned in separate spaces, and there is no competition between the combustion of ammonia and the combustion of carbon-containing fuel. Furthermore, by premixing a portion of the air with ammonia before combustion and adjusting the optimal conditions for combustion, an optimal amount of oxygen is supplied for each combustion, and NO X It is possible to suppress the increase in emissions and unburned fuel in ash.

[0069] [Fourth embodiment] Next, an ammonia-mixed combustion burner according to the fourth embodiment will be described. The boiler 1 provided in the ammonia-mixed combustion system shown in Fig. 1 is the same as the first embodiment except for the ammonia-mixed combustion burner 4, and therefore the description thereof will be omitted. In the description of the fourth embodiment, the description of the same parts as the above-mentioned embodiments will be omitted or simplified.

[0070] The ammonia-mixed combustion burner 4d according to the fourth embodiment will be described with reference to Fig. 5. The carbon-containing fuel supply passage 41 in the ammonia-mixed combustion burner 4d is a first injection nozzle 41d that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber 2. The ammonia supply passage 42 in the ammonia-mixed combustion burner 4d is an ammonia supply passage 42d that mixes ammonia and air and supplies the mixture into the combustion chamber 2. That is, the ammonia-mixed combustion burner 4d according to the fourth embodiment includes a first injection nozzle 41d and an ammonia supply passage 42d.

[0071] The ammonia mixed combustion burner 4d includes an ammonia injection nozzle 47d that injects ammonia into the combustion chamber 2. The above-mentioned fuel ammonia supply pipe 6b1 is connected to the ammonia injection nozzle 47d. The first injection nozzle 41d may be formed to surround the ammonia injection nozzle 47d and may have a double cylindrical shape that is concentric with the ammonia injection nozzle 47d. That is, the first injection nozzle 41d may be an outer cylindrical part and the ammonia injection nozzle 47d may be an inner cylindrical part, and the nozzle axis L of the ammonia injection nozzle 47d may be the center. In addition, the injection direction of the first injection nozzle 41d and the injection direction of the ammonia injection nozzle 47d may be oriented in the same direction as the nozzle axis L.

[0072] On the other hand, the ammonia-mixed combustion burner 4d includes an ammonia supply passage 42d that mixes ammonia and secondary air through a swirler 45d and supplies the mixture into the combustion chamber 2. The ammonia supply passage 42d is disposed so as to surround the outside of the nozzle of the first injection nozzle 41d.

[0073] The air supply unit 8 is connected to the ammonia supply passage 42d and supplies secondary air for combustion from the radially outer side to the flame. The secondary air supplied to the combustion chamber 2 via the ammonia supply passage 42d is heated by a heating device (not shown) provided upstream of the air supply unit 8 and has a temperature higher than room temperature.

[0074] The swirler 45d has a function similar to that of the swirler 45a in the first embodiment, is provided on the upstream side of the ammonia supply passage 42d, and finely adjusts the swirling force of the secondary air flowing into the ammonia supply passage 42d.

[0075] Furthermore, the ammonia-mixed combustion burner 4d is provided with a tertiary air supply passage 44d arranged to surround the ammonia supply passage 42d. The tertiary air supply passage 44d supplies tertiary air for combustion to the flame from the radially outer side. A swirler 45e is provided upstream of the ammonia supply passage 42d and the tertiary air supply passage 44d. The swirler 45e finely adjusts the swirling force of the secondary air flowing into the ammonia supply passage 42d and the tertiary air flowing into the tertiary air supply passage 44d.

[0076] In the ammonia-mixed combustion burner 4d, ammonia is injected from the ammonia injection nozzle 47d, and carbon-containing fuel and air are injected from the first injection nozzle 41d. Furthermore, in the ammonia-mixed combustion burner 4d, ammonia and secondary air are supplied from the ammonia supply passage 42d, and tertiary air for combustion is supplied, so that flames F1 and F2 are formed in front of the ammonia-mixed combustion burner 4d, as shown in FIG.

[0077] The flame F2 is an ammonia flame produced by combustion when ammonia is injected from the ammonia injection nozzle 47d, or when ammonia and secondary air are injected from the ammonia supply passage 42d. The flame F2 produced by combustion when ammonia is injected from the ammonia injection nozzle 47d is formed in a linear direction along the nozzle axis L. On the other hand, the flame F2 produced by combustion when injected from the ammonia supply passage 42d is formed toward the radial outside of the nozzle axis L by an internal circulating flow (dotted lines and arrows in FIG. 5) in the combustion chamber 2, which is generated by the swirling force of the secondary air and the tertiary air.

[0078] On the other hand, the flame F1 is a carbon-containing fuel flame that is burned by injecting a carbon-containing fuel and air from the first injection nozzle 41d. The flame F1 is formed in a position sandwiched between the flames F2 toward the radially outward direction of the nozzle axis L by the internal circulating flow in the combustion chamber 2.

[0079] When the flames F1 and F2 are formed in this manner, the outer edge region of the flame F2 (the region radially outward from the nozzle axis L) and the tip regions of the flames F1 and F2 become low oxygen concentration regions where the oxygen concentration is low.

[0080] Ammonia is supplied into the combustion chamber 2 from the ammonia injection nozzle 47d and the ammonia supply passage 42d of the ammonia-mixed combustion burner 4d, and the ammonia is injected into the oxygen concentration low region where the oxygen concentration is low. Therefore, similar to the first embodiment, the ammonia-mixed combustion burner 4d can suppress an increase in NOx.

[0081] Thus, the ammonia-mixed combustion burner 4d according to the fourth embodiment includes a first injection nozzle 41d that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber 2, and an ammonia supply passage 42d that mixes ammonia and air and supplies the mixture into the combustion chamber 2. Therefore, during the mixed combustion, ammonia and carbon-containing fuel are burned in separate spaces, and there is no competition between the combustion of ammonia and the combustion of carbon-containing fuel. Furthermore, by premixing a portion of the air with ammonia before combustion and adjusting the optimal conditions for combustion, an optimal amount of oxygen is supplied for each combustion, and NO X It is possible to suppress the increase in emissions and unburned fuel in ash.

[0082] As described above, the ammonia co-firing burner is installed in the combustion chamber, and supplies ammonia and carbon-containing fuel into the combustion chamber to burn them. The ammonia co-firing burner is equipped with a carbon-containing fuel supply passage or a first injection nozzle that mixes the carbon-containing fuel and air and supplies them into the combustion chamber, and an ammonia supply passage or a second injection nozzle that mixes the ammonia and air and supplies them into the combustion chamber 2. Therefore, during co-firing, the ammonia and the carbon-containing fuel are burned in separate spaces, and there is no competition between the combustion of the ammonia and the carbon-containing fuel. Furthermore, by premixing a portion of the air with the ammonia before combustion and adjusting the optimal conditions for combustion, an optimal amount of oxygen is supplied for each combustion, and NO X It is possible to suppress the increase in emissions and unburned fuel in ash.

[0083] The ammonia co-firing system has a combustion chamber and an ammonia co-firing burner that supplies ammonia and a carbon-containing fuel into the combustion chamber and burns them. As a method for manufacturing such an ammonia co-firing system, it is not necessary to build new equipment, and manufacturing costs can be reduced by modifying existing equipment such as a pulverized coal burner. For example, an existing pulverized coal burner can be modified by connecting a connection path to a secondary air supply flow path that supplies secondary air into the combustion chamber, and an ammonia supply flow path that mixes ammonia and air and supplies it into the combustion chamber can be installed. In addition, it is also possible to replace the injection nozzle of the existing pulverized coal burner that injects fuel or air into the combustion chamber with a second injection nozzle that mixes ammonia and air and injects it into the combustion chamber.

[0084] [Manufacturing method for ammonia co-firing system 1] As a manufacturing method, for example, a burner equipped with a first injection nozzle that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber is modified. Specifically, the burner is modified by connecting a connection path to a secondary air supply passage that supplies air into the combustion chamber, and ammonia is supplied to the secondary air supply passage. Then, the secondary air passage is replaced with an ammonia supply passage that mixes ammonia and air and supplies the mixture into the combustion chamber. In this way, an ammonia supply passage is installed in the ammonia-mixed combustion burner. Furthermore, a swirler is installed in the ammonia supply passage. The modified ammonia-mixed combustion burner is equipped with a first injection nozzle and an ammonia supply passage. The air injection nozzle may be formed to surround the first injection nozzle and may be a double-cylinder shape that is concentrically arranged with the first injection nozzle. In this way, the ammonia-mixed combustion burner 4c according to the third embodiment (FIG. 4) can be manufactured.

[0085] The air supply passage may be divided into a plurality of air supply passages, and may be modified by connecting a connecting path to at least a part of the plurality of air supply passages to provide an ammonia supply passage that mixes ammonia and air and supplies the mixture to the combustion chamber. For example, the secondary air supply passage that supplies air to the combustion chamber may be divided into a secondary air supply passage and a tertiary air supply passage, and then modified by connecting a connecting path to the secondary air supply passage to supply ammonia to the secondary air supply passage. In this way, the secondary air supply passage is replaced with an ammonia supply passage that mixes ammonia and air and supplies the mixture to the combustion chamber. On the other hand, the tertiary air supply passage supplies tertiary air to the combustion chamber. Furthermore, by providing a swirler upstream of the ammonia supply passage and the tertiary air supply passage, an ammonia supply passage and a tertiary air supply passage can be provided in the same manner as the ammonia supply passage 42d and the tertiary air supply passage 44d of the above-mentioned fourth embodiment (FIG. 5).

[0086] [Manufacturing method of ammonia co-firing system 2] As a manufacturing method, for example, a burner having a double-cylinder shape is modified in which a first injection nozzle that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber is formed to surround an ammonia injection nozzle that injects ammonia into the combustion chamber and is arranged concentrically with the ammonia injection nozzle. Specifically, the burner is modified by connecting a connection path to a secondary air supply passage that supplies air into the combustion chamber, and ammonia is supplied to the secondary air supply passage. Then, the secondary air supply passage is replaced with an ammonia supply passage that mixes ammonia and air and supplies the mixture into the combustion chamber. In this way, an ammonia supply passage is installed in the ammonia-mixed combustion burner. Furthermore, a swirler is installed in the ammonia supply passage. The modified ammonia-mixed combustion burner is equipped with a first injection nozzle and an ammonia supply passage.

[0087] The air supply passage is divided into a plurality of air supply passages, and may be modified by connecting a connecting path to at least a part of the plurality of air supply passages to provide an ammonia supply passage that mixes ammonia and air and supplies the ammonia and air to the combustion chamber. For example, the secondary air supply passage is replaced with an ammonia supply passage, while the tertiary air supply passage supplies tertiary air to the combustion chamber. Furthermore, by providing a swirler upstream of the ammonia supply passage and the tertiary air supply passage, the ammonia-mixed combustion burner 4d according to the fourth embodiment (FIG. 5) can be manufactured.

[0088] [Manufacturing method of ammonia co-firing system 3] As a manufacturing method, for example, a burner having a double-cylinder shape is modified, in which a first injection nozzle that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber is formed to surround an ammonia injection nozzle that injects ammonia into the combustion chamber, and is arranged concentrically with the ammonia injection nozzle. Specifically, the burner is modified by connecting a connection path to the ammonia injection nozzle, and air is supplied to the ammonia supply flow path. Then, the ammonia injection nozzle is replaced with a second injection nozzle that mixes ammonia and air and supplies the mixture into the combustion chamber. In this way, the second injection nozzle is installed in the ammonia co-firing burner. The modified ammonia co-firing burner is equipped with the first injection nozzle and the second injection nozzle.

[0089] The injection direction of the first injection nozzle and the injection direction of the second injection nozzle may be oriented in the same direction as the nozzle axis. Also, a swirler may be installed in the secondary air supply passage, and a secondary air supply passage may be installed that supplies air through the swirler into the combustion chamber. In this way, the ammonia-mixed combustion burner 4a according to the first embodiment (FIG. 2) can be manufactured.

[0090] [Manufacturing method of ammonia co-firing system 4] As a manufacturing method, for example, a burner equipped with a first injection nozzle that mixes carbon-containing fuel and air and injects the mixture into the combustion chamber is modified. Specifically, the burner is modified by installing a second injection nozzle that mixes ammonia and air and injects the mixture into the combustion chamber outside the first injection nozzle. The modified ammonia co-firing burner is equipped with the first injection nozzle and the second injection nozzle.

[0091] The second injection nozzle may be formed to surround the first injection nozzle and may have a double-cylinder shape provided concentrically with the first injection nozzle. The injection direction of the first injection nozzle and the injection direction of the second injection nozzle may be oriented in the same direction as the nozzle axis. A swirler may be provided in the secondary air supply passage, and a secondary air supply passage may be provided that supplies air through the swirler into the combustion chamber. This makes it possible to manufacture the ammonia-mixed combustion burner 4b according to the second embodiment (FIG. 3).

[0092] As described above, the ammonia co-firing burner according to the present embodiment is installed in a combustion chamber, and supplies ammonia and a carbon-containing fuel into the combustion chamber to combust them. The ammonia co-firing burner includes a carbon-containing fuel supply passage that mixes the carbon-containing fuel and air and supplies the mixture into the combustion chamber, and an ammonia supply passage that mixes the ammonia and air and supplies the mixture into the combustion chamber. The ammonia co-firing system includes a combustion chamber and an ammonia co-firing burner that supplies ammonia and a carbon-containing fuel into the combustion chamber to combust them. Therefore, as a method for manufacturing the ammonia co-firing system, the manufacturing cost can be reduced by modifying existing equipment such as a pulverized coal burner.

[0093] Although several embodiments have been described, the embodiments can be modified or modified based on the above disclosure. All components of the above embodiments and all features described in the claims may be individually extracted and combined as long as they are not mutually inconsistent.

[0094] This disclosure can contribute, for example, to Goal 7 of the United Nations-led Sustainable Development Goals (SDGs), "Ensure access to affordable, reliable, sustainable and modern energy for all" and Goal 13, "Take urgent action to combat climate change and its impacts."

[0095] The entire contents of Patent Application No. 2023-132239 (filing date: August 15, 2023) are incorporated herein by reference. [Explanation of symbols]

[0096] 1. Boiler 2. Combustion chamber 4, 4a, 4b, 4c, 4d Ammonia co-firing burner 41 Carbon-containing fuel supply passage 41a, 41b, 41c, 41d First injection nozzle (carbon-containing fuel supply passage) 42, 42c, 42d Ammonia supply channel 42a, 42b Second injection nozzle (ammonia supply passage) 43a, 43b Secondary air supply passage (air supply passage) 45a, 45b, 45c, 45d, 45e Swara

Claims

1. An ammonia co-fuel burner that is installed in a combustion chamber and supplies ammonia and a carbon-containing fuel to the combustion chamber and combusts them, A carbon-containing fuel supply passage that mixes carbon-containing fuel and air and supplies the mixture to the combustion chamber; an ammonia supply passage that mixes ammonia and air and supplies the mixture to the combustion chamber; Equipped with The air supply passage is disposed so as to directly surround the outside of the jet outlet of the jet nozzle having a double cylindrical shape that is concentrically arranged, The carbon-containing fuel supply passage is a first injection nozzle that mixes a carbon-containing fuel and air and injects the mixture into the combustion chamber, The ammonia supply passage is a second injection nozzle that mixes ammonia and air and injects the mixture into the combustion chamber, The injection nozzle has a double cylinder shape in which a second injection nozzle is formed to surround a first injection nozzle, and the first injection nozzle and the second injection nozzle are concentrically provided, The injection direction of the first injection nozzle and the injection direction of the second injection nozzle are directed in the same direction as a nozzle axis line, The air supply passage supplies air into the combustion chamber through a swirler.

2. The combustion chamber; A method for producing an ammonia co-firing system having the ammonia co-firing burner according to claim 1, A method for manufacturing an ammonia co-firing system, comprising: modifying a burner having the first injection nozzle by installing the second injection nozzle outside the first injection nozzle.

3. 3. The method for producing an ammonia co-firing system according to claim 2, wherein the injection direction of the first injection nozzle and the injection direction of the second injection nozzle are oriented in the same direction as a nozzle axis line, and an air supply flow passage is provided in the combustion chamber to supply air through a swirler.

4. A combustion chamber; and an ammonia co-combustion burner that is installed in the combustion chamber and supplies ammonia and a carbon-containing fuel to the combustion chamber and combusts them, The ammonia co-fuel burner includes a carbon-containing fuel supply passage that mixes carbon-containing fuel and air and supplies the mixture into the combustion chamber, and an ammonia supply passage that mixes ammonia and air and supplies the mixture into the combustion chamber, The air supply passage is disposed so as to directly surround the outside of the jet outlet of the jet nozzle having a double cylindrical shape that is concentrically arranged, The carbon-containing fuel supply passage is a first injection nozzle that mixes a carbon-containing fuel and air and injects the mixture into the combustion chamber, The injection nozzle has an air injection nozzle for injecting air into the combustion chamber, the air injection nozzle is formed to surround a first injection nozzle, and the air injection nozzle and the first injection nozzle are concentrically arranged to have a double cylindrical shape, The injection direction of the air injection nozzle and the injection direction of the first injection nozzle are directed in the same direction as a nozzle axis line, A method for manufacturing an ammonia co-firing system, comprising the steps of: modifying the air supply flow path for supplying air into the combustion chamber by connecting a connecting path; installing the ammonia supply flow path for mixing ammonia and air and supplying the mixture into the combustion chamber; and installing a swirler in the ammonia supply flow path.

5. A combustion chamber; and an ammonia co-combustion burner that is installed in the combustion chamber and supplies ammonia and a carbon-containing fuel to the combustion chamber and combusts them, The ammonia co-fuel burner includes a carbon-containing fuel supply passage that mixes carbon-containing fuel and air and supplies the mixture into the combustion chamber, and an ammonia supply passage that mixes ammonia and air and supplies the mixture into the combustion chamber, The air supply passage is disposed so as to directly surround the outside of the jet outlet of the jet nozzle having a double cylindrical shape that is concentrically arranged, The carbon-containing fuel supply passage is a first injection nozzle that mixes a carbon-containing fuel and air and injects the mixture into the combustion chamber, The injection nozzle is formed such that a first injection nozzle surrounds an ammonia injection nozzle that injects ammonia into the combustion chamber, and the first injection nozzle and the ammonia injection nozzle are concentrically arranged to have a double cylindrical shape, The injection direction of the first injection nozzle and the injection direction of the ammonia injection nozzle are directed in the same direction as a nozzle axis line, A method for manufacturing an ammonia co-firing system, comprising the steps of: modifying the air supply flow path for supplying air into the combustion chamber by connecting a connecting path; installing the ammonia supply flow path for mixing ammonia and air and supplying the mixture into the combustion chamber; and installing a swirler in the ammonia supply flow path.

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