Combustion furnace, boiler, power generation equipment, and control method for a combustion furnace

Abstract

The accumulation of unburned ammonia and nitrous oxide should be properly prevented. [Solution] Combustion gas produced by the combustion of pulverized fuel and ammonia fuel combustion When performing a mixed-combustion operation in which the fuel is flowed in the flow direction FD in the furnace 11 and discharged to the outside, and fine fuel is injected from at least one of the multiple combustion burners 100B, 100D, and 100F, and ammonia fuel is injected from at least one of the multiple combustion burners 100A, 100C, and 100E, the control unit controls the solid fuel adjustment unit and the ammonia fuel adjustment unit so that the fuel injected at the upstream end of the flow direction FD is fine fuel. combustion A furnace 11 is provided.

Description

Technical Field

[0001] The present disclosure relates to a combustion furnace, a boiler, a power generation facility, and combustion a method for controlling a furnace.

Background Art

[0002] Conventionally, a boiler that co-fires pulverized coal and ammonia has been known (for example, see Patent Document 1). The boiler disclosed in Patent Document 1 arranges a plurality of burners at intervals from the upstream side to the downstream side in the flow direction of combustion gas, and supplies ammonia to other burners except the burner on the most downstream side. According to the boiler disclosed in Patent Document 1, since ammonia is supplied to burners on the upstream side rather than the most downstream side in the flow direction of combustion gas, sufficient time can be ensured to decompose NOx generated by the combustion of ammonia into nitrogen, compared with the case of supplying ammonia to the burner on the most downstream side in the flow direction of combustion gas.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the boiler disclosed in Patent Document 1, ammonia is supplied to the burner on the most upstream side in the flow direction of combustion gas. However, the ambient temperature at the position in the flow direction where the burner on the most upstream side is arranged is lower than the positions in the flow direction where other burners are arranged. Therefore, in the lower part of the furnace where the ambient gas temperature is low, a part of ammonia may flow through the furnace without burning and be discharged out of the system as unburned ammonia. combustion In the lower part of the furnace where the ambient gas temperature is low, combustion a part of ammonia may flow through the furnace without burning and be discharged out of the system as unburned ammonia.

[0005] Also, where the ambient gas temperature is low combustionIn the lower part of the furnace, nitrous oxide (N2O), which is produced during the combustion of ammonia, remains undecomposed. combustion It can circulate within the reactor and potentially be emitted outside the system. Because the global warming potential of nitrous oxide is extremely high compared to carbon dioxide (CO2), a typical greenhouse gas, it is necessary to reduce its emissions.

[0006] This disclosure has been made in view of the above circumstances, and relates to a combustion furnace, boiler, power generation equipment, and that is capable of appropriately suppressing the emission of unburned ammonia and nitrous oxide outside the system. combustion The objective is to provide a method for controlling a furnace. [Means for solving the problem]

[0007] To solve the above problems, one aspect of this disclosure combustion Furnaces, boilers, power generation equipment, and combustion The following methods will be employed to control the reactor.

[0008] A particular aspect of this disclosure combustion The furnace is capable of co-firing ammonia fuel containing ammonia and a first fuel different from the ammonia fuel, and at each of the multiple first placement positions arranged at intervals in a predetermined direction, from multiple locations combustion Multiple first fuel burners that inject the first fuel into the furnace and burn it, and multiple locations at each of the second placement positions which are spaced apart in a predetermined direction and different from the first placement position, from which the first fuel is released combustion The furnace comprises a plurality of ammonia fuel burners that inject and burn the ammonia fuel, a first fuel adjustment unit that adjusts the amount of the first fuel supplied to the first fuel burner, an ammonia fuel adjustment unit that adjusts the amount of the ammonia fuel supplied to the ammonia fuel burner, and a control unit that controls the first fuel adjustment unit and the ammonia fuel adjustment unit, wherein the combustion gas generated by the combustion of the first fuel and the ammonia fuel is combustionIn a boiler that circulates fuel in a predetermined direction in a furnace and discharges it to the outside, the control unit controls the first fuel adjustment unit and the ammonia fuel adjustment unit so that the fuel injected at the upstream end in the predetermined direction becomes the first fuel when performing a co-firing operation in which the first fuel is injected from at least one of the plurality of first fuel burners and the ammonia fuel is injected from at least one of the plurality of ammonia fuel burners.

[0009] A particular aspect of this disclosure combustion In a reactor control method, combustion The furnace is capable of co-firing ammonia fuel containing ammonia and a first fuel different from the ammonia fuel, and at each of the multiple first placement positions arranged at intervals in a predetermined direction, from multiple locations combustion Multiple first fuel burners that inject the first fuel into the furnace and burn it, and multiple locations at each of the second placement positions which are spaced apart in a predetermined direction and different from the first placement position, from which the first fuel is released combustion The furnace comprises a plurality of ammonia fuel burners that inject and burn the ammonia fuel, a first fuel adjustment unit that adjusts the amount of the first fuel supplied to the first fuel burner, and an ammonia fuel adjustment unit that adjusts the amount of the ammonia fuel supplied to the ammonia fuel burner, wherein the combustion gas generated by the combustion of the first fuel and the ammonia fuel is combustion The system includes a control step that controls the first fuel adjustment unit and the ammonia fuel adjustment unit so that when performing a co-firing operation in which the fuel is circulated in the furnace in the predetermined direction and discharged to the outside, the first fuel is injected from at least one of the plurality of first fuel burners, and the ammonia fuel is injected from at least one of the plurality of ammonia fuel burners, the fuel injected at the upstream end in the predetermined direction is the first fuel. [Effects of the Invention]

[0010] According to this disclosure, a combustion furnace, boiler, power generation equipment, and a combustion furnace, boiler, power generation equipment capable of appropriately suppressing the emission of unburned ammonia and nitrous oxide outside the system, combustionA method for controlling a furnace can be provided.

Brief Description of the Drawings

[0011] [Figure 1] It is a schematic configuration diagram showing a boiler according to an embodiment of the present disclosure. [Figure 2] It is a cross-sectional view of a combustion burner for injecting ammonia fuel shown in FIG. 1. [Figure 3] It is a cross-sectional view of a combustion burner for injecting solid fuel shown in FIG. 1. [Figure 4] It is a partially enlarged view of the combustion furnace shown in FIG. 1. [Figure 5] It is a flowchart showing a method for controlling a boiler according to an embodiment of the present disclosure. [Figure 6] It is a diagram showing the relationship between the distance from the bottom of the combustion furnace and the temperature.

Modes for Carrying Out the Invention

[0012] Hereinafter, a boiler 10 provided with a combustion furnace (furnace) 11 according to an embodiment of the present disclosure will be described with reference to the drawings. The boiler 10 according to the present embodiment is a device that burns pulverized fuel (solid fuel) and ammonia fuel by a combustion burner and recovers the heat generated by this combustion. Note that, for the boiler 10 according to the present embodiment combustion The fuel that the furnace 11 burns together with the ammonia fuel may be other fuels different from the pulverized fuel as long as it is a fuel more flammable than the ammonia fuel.

[0013] FIG. 1 is a schematic configuration diagram showing a boiler 10 according to an embodiment of the present disclosure. As shown in FIG. 1, the boiler 10 of the present embodiment combustion has a furnace 11, a combustion device 12, and a flue 13. combustion The furnace 11 has a hollow shape of a square cylinder and is installed along the vertical direction, and combustion the combustion device 12 is provided at the lower part of the furnace wall constituting the furnace 11. The boiler 10 of the present embodiment burns the combustion gas generated by the combustion of pulverized fuel and ammonia fuel combustionIt is circulated vertically in the VD direction in the furnace 11 and discharged to the flue 13.

[0014] The combustion device 12 has a plurality of combustion burners 100A, 100B, 100C, 100D, 100E, 100F attached to the furnace wall. In this embodiment, these combustion burners 100A, 100B, 100C, 100D, 100E, 100F combustion Taking four pieces arranged at equal intervals along the circumferential direction centered on the vertical direction VD in which the furnace 11 extends as one set, six sets (six stages) are arranged along the vertical direction. Here, six sets are used, but any other number of sets can be used.

[0015] The combustion burners (solid fuel burners) 100B, 100D, 100F are connected to the pulverizers 31, 32, 33 via the pulverized fuel supply pipes 26, 27, 28. The pulverizers 31, 32, 33 pulverize solid fuels such as biomass fuel and coal into pulverized fuel and supply it to the pulverized fuel supply pipes 26, 27, 28 together with a conveying gas such as air. The pulverized fuel is supplied from the pulverized fuel supply pipes 26, 27, 28 to the combustion burners 100B, 100D, 100F.

[0016] The pulverizers 31, 32, 33 are respectively connected to the solid fuel adjustment units 31a, 32a, 33a via the solid fuel supply pipes 31b, 32b, 33b. The supply amount of the pulverized fuel supplied to the combustion burners 100B, 100D, 100F via the pulverized fuel supply pipes 26, 27, 28 is controlled by adjusting the amount of the solid fuel supplied to the pulverizers 31, 32, 33 by the solid fuel adjustment units 31a, 32a, 33a.

[0017] In FIG. 1, an example in which a belt conveyor type fuel supply machine (coal feeder) is applied to the solid fuel adjustment units 31a, 32a, 33a is shown. For example, the amount of the solid fuel supplied to the pulverizers 31, 32, 33 is adjusted by the moving speed of the belt of the belt conveyor. Here, since unpulverized solid carbonaceous fuel remains inside the pulverizers 31, 32, 33, the adjustment of the solid fuel supply amount by the moving speed of the belt is reflected in the amount of the pulverized fuel supplied to the combustion burner with a certain delay time.

[0018] The combustion burners (ammonia fuel burners) 100A, 100C, and 100E are connected to the ammonia fuel supply unit 50 via ammonia fuel supply pipes 51, 52, and 53. The ammonia fuel supply unit 50 supplies liquid or gaseous ammonia fuel containing ammonia as a component to the ammonia fuel supply pipes 51, 52, and 53. The ammonia fuel is then supplied from the ammonia fuel supply pipes 51, 52, and 53 to the combustion burners 100A, 100C, and 100E.

[0019] Ammonia fuel adjustment units 51a, 52a, and 53a are provided in the ammonia fuel supply pipes 51, 52, and 53, respectively. The ammonia fuel adjustment units 51a, 52a, and 53a use, for example, control valves that adjust the amount of fuel supplied by the degree of opening. The ammonia fuel adjustment units 51a, 52a, and 53a adjust the amount of ammonia fuel supplied from the ammonia fuel supply pipes 51, 52, and 53 to the combustion burners 100A, 100C, and 100E.

[0020] The boiler 10 includes a control unit 60 that controls each part of the boiler 10, including the solid fuel adjustment units 31a, 32a, 33a and the ammonia fuel adjustment units 51a, 52a, 53a. The control unit 60 indirectly adjusts the amount of pulverized fuel supplied from the pulverized fuel supply pipes 26, 27, 28 to the combustion burners 100B, 100D, 100F by controlling the belt movement speed of the solid fuel adjustment units 31a, 32a, 33a and thereby controlling the amount of solid fuel supplied to the crushers 31, 32, 33.

[0021] Furthermore, the control unit 60 adjusts the amount of ammonia fuel supplied from the ammonia fuel supply pipes 51, 52, and 53 to the combustion burners 100A, 100C, and 100E by controlling the opening of the ammonia fuel adjustment units 51a, 52a, and 53a. In other words, the ammonia fuel adjustment units 51a, 52a, and 53a directly control the amount of ammonia fuel supplied.

[0022] combustionThe furnace 11 has wind boxes 36 at the mounting positions of each combustion burner 100A, 100B, 100C, 100D, 100E, and 100F. One end of an air duct 37 is connected to the wind box 36. A blower 38 is attached to the other end of the air duct 37. combustion The furnace 11 is provided with additional air nozzles 39 located vertically above the mounting positions of each combustion burner 100A, 100B, 100C, 100D, and 100E.

[0023] The additional air nozzle 39 is connected to the end of a branch air duct 40 that branches off from the air duct 37. Combustion air supplied by the blower 38 is supplied from the air duct 37 to the wind box 36, and from the wind box 36 to each of the combustion burners 100A, 100B, 100C, 100D, and 100E. Combustion air supplied by the blower 38 is also supplied from the branch air duct 40 to the additional air nozzle 39.

[0024] combustion A flue 13 is connected to the vertical upper part of the furnace 11. The flue 13 is equipped with superheaters 41, 42, reheaters 43, 44, and economizers 45, 46, 47, which are heat exchangers for recovering heat from the combustion gases. These heat exchangers are combustion Heat exchange takes place between the combustion gases generated by combustion in furnace 11 and water or steam.

[0025] An exhaust gas pipe 48 is connected to the flue 13 on the downstream side of the gas flow, through which the heat-exchanged combustion gas is discharged as exhaust gas. An air heater 49 is installed between the exhaust gas pipe 48 and the air duct 37, and heat exchange occurs between the air flowing through the air duct 37 and the exhaust gas flowing through the exhaust gas pipe 48, raising the temperature of the combustion air supplied to the combustion burners 100A, 100B, 100C, 100D, and 100E. A chimney (not shown) is provided at the downstream end of the exhaust gas pipe 48.

[0026] Combustion burners 100A, 100B, 100C, 100D, and 100E use fine fuel and ammonia fuel. combustion The combustion air is blown into the furnace 11. combustionThe material is blown into the furnace 11, and ignited at this time to form a flame. combustion In furnace 11, fine fuel and ammonia fuel burn with combustion air to produce a flame, combustion When a flame is generated in the lower vertical region inside the furnace 11, the combustion gases (exhaust gases) combustion It rises inside the furnace 11 and is discharged into the flue 13.

[0027] Water supplied from the feedwater pump (not shown) is preheated by economizers 45, 46, and 47, then introduced into superheaters 41 and 42 via heat transfer tubes (not shown) that make up the furnace wall, where superheated steam is generated through heat exchange with the combustion gas.

[0028] The superheated steam generated in superheaters 41 and 42 is supplied to a steam turbine (not shown) of the power plant (power generation equipment). The steam turbine is connected to a generator and generates electricity by driving the generator with steam generated in the boiler 10. The steam turbine may be a multi-stage turbine equipped with a low-pressure turbine that utilizes steam discharged from a high-pressure turbine and reheated by introducing the steam into reheaters 43 and 44 of the boiler 10.

[0029] Next, the combustion device 12 will be described in detail. Figure 2 is a cross-sectional view of the combustion burner (ammonia fuel burner) 100A that injects the ammonia fuel shown in Figure 1. The configurations of the combustion burners 100C and 100D are the same as those of the combustion burner 100A, so their explanation will be omitted below.

[0030] As shown in Figure 2, the combustion burner 100A is combustion The furnace 11 has four walls 11a, 11b, 11c, and 11d, each equipped with ammonia fuel burners 110a, 110b, 110c, and 110d. The walls 11a, 11b, 11c, and 11d are each installed along the vertical direction VD.

[0031] The ammonia fuel burners 110a, 110b, 110c, and 110d are connected to branch pipes 51A, 51B, 51C, and 51D, respectively, which are branched from the ammonia fuel supply pipe 51. In addition, the ammonia fuel burners 110a, 110b, 110c, and 110d are connected to branch pipes 37a, 37b, 37c, and 37d, respectively, which are branched from the air duct 37.

[0032] The ammonia fuel burner 110a is installed on wall surface 11a and is located in a position close to wall surface 11b among wall surfaces 11b and 11d which are positioned opposite to wall surface 11a. The ammonia fuel burner 110b is installed on wall surface 11b and is located in a position close to wall surface 11c among wall surfaces 11a and 11c which are positioned opposite to wall surface 11b.

[0033] The ammonia fuel burner 110c is installed on wall surface 11c and is located in a position close to wall surface 11d among wall surfaces 11d and 11b which are positioned opposite to wall surface 11c. The ammonia fuel burner 110d is installed on wall surface 11d and is located in a position close to wall surface 11a among wall surfaces 11a and 11c which are positioned opposite to wall surface 11d.

[0034] therefore, combustion Each ammonia fuel burner 110a, 110b, 110c, 110d located on each wall of the furnace 11 is, combustion Ammonia fuel is supplied to reactor 11. combustion By blowing in with a slight angle of deviation relative to the center Ct of the furnace 11, four flames F1, F2, F3, and F4 can be formed. Flames F1, F2, F3, and F4 are combustion When viewed from above the furnace 11, the flame swirling flow rotates counterclockwise. Here, we have assumed a counterclockwise rotation, but the ammonia fuel burners 110a, 110b, 110c, and 110d may be arranged to produce a clockwise rotation of the flame swirling flow.

[0035] Figure 3 is a cross-sectional view of the combustion burner (solid fuel burner) 100B that injects the solid fuel shown in Figure 1. The configurations of combustion burners 100D and 100F are the same as those of combustion burner 100B, so their explanations are omitted below.

[0036] As shown in Figure 3, the combustion burner 100B is combustion The furnace 11 has solid fuel burners 120a, 120b, 120c, and 120d attached to the four wall surfaces 11a, 11b, 11c, and 11d that form the furnace 11.

[0037] The solid fuel burners 120a, 120b, 120c, and 120d are connected to branch pipes 26a, 26b, 26c, and 26d, respectively, which are branched from the fine fuel supply pipe 26. In addition, the solid fuel burners 120a, 120b, 120c, and 120d are connected to branch pipes 37a, 37b, 37c, and 37d, respectively, which are branched from the air duct 37.

[0038] The solid fuel burner 120a is installed on wall surface 11a and is located in a position close to wall surface 11b among wall surfaces 11b and 11d which are positioned opposite to wall surface 11a. The solid fuel burner 120b is installed on wall surface 11b and is located in a position close to wall surface 11c among wall surfaces 11a and 11c which are positioned opposite to wall surface 11b.

[0039] The solid fuel burner 120c is installed on wall surface 11c and is located in a position close to wall surface 11d among wall surfaces 11d and 11b which are positioned opposite to wall surface 11c. The solid fuel burner 120d is installed on wall surface 11d and is located in a position close to wall surface 11a among wall surfaces 11a and 11c which are positioned opposite to wall surface 11d.

[0040] therefore, combustion Each solid fuel burner 120a, 120b, 120c, 120d located on each wall of the furnace 11 is, combustion For reactor 11, fine fuel combustionBy blowing in with a slight angle to the center of the furnace 11, four flames F1, F2, F3, and F4 can be formed. Flames F1, F2, F3, and F4 are combustion When viewed from above the furnace 11, the flame swirling flow rotates counterclockwise. Here, we have assumed a counterclockwise rotation, but the solid fuel burners 120a, 120b, 120c, and 120d may be arranged to produce a clockwise rotation of the flame swirling flow.

[0041] As shown in Figures 2 and 3, the ammonia fuel burner 110a and the solid fuel burner 120a are, combustion When the reactor 11 is viewed in plan along the vertical direction VD, the ammonia fuel burner 110b and the solid fuel burner 120b are located at the same position on the wall surface 11a. combustion When the reactor 11 is viewed in plan along the vertical direction VD, the ammonia fuel burner 110c and the solid fuel burner 120c are located at the same position on the wall surface 11b. combustion When the reactor 11 is viewed in plan along the vertical direction VD, the ammonia fuel burner 110d and the solid fuel burner 120d are located at the same position on the wall surface 11c. combustion When the furnace 11 is viewed in plan along the vertical direction VD, it is positioned at the same location on the wall surface 11d.

[0042] The combustion burner 100A shown in Figure 2 is combustion The furnace 11 has four ammonia fuel burners 110a, 110b, 110c, and 110d attached to the four walls 11a, 11b, 11c, and 11d forming the furnace, and employs a swirling combustion method that forms a flame swirling flow, but other methods may also be used. For example, combustion A counter-combustion system may be used in which multiple ammonia fuel burners are arranged on each of a pair of opposing wall surfaces in the furnace 11.

[0043] Next, referring to Figure 4, the arrangement of the combustion burners 100A, 100B, 100C, 100D, 100E, and 100F in the combustion device 12 of the boiler 10 of this embodiment will be described. Figure 4 is shown in Figure 1. combustionThis is a partially enlarged view of the furnace 11. As shown in Figure 4, the boiler 10 of this embodiment is arranged at multiple first placement positions P1a, P1b, and P1c, which are spaced apart in the vertical direction VD along the axis Z, and at each of these positions, multiple points around the axis Z combustion The furnace 11 is equipped with multiple combustion burners 100B, 100D, and 100F for injecting and burning solid fuel.

[0044] In this embodiment, the flow direction FD of the combustion gas generated by the combustion of pulverized fuel and ammonia fuel in the combustion device 12 coincides with the vertical direction VD. A combustion burner 100F is positioned at the first position P1a. A combustion burner 100D is positioned at the first position P1b, which is downstream of the first position P1a in the flow direction FD. A combustion burner 100B is positioned at the first position P1c, which is downstream of the first position P1b in the flow direction FD.

[0045] In this embodiment, the boiler 10 is arranged at multiple second placement positions P2a, P2b, and P2c, which are spaced apart in the vertical direction VD along the axis Z, and at each of these positions, from multiple points around the axis Z combustion The furnace 11 is equipped with multiple combustion burners 100A, 100C, and 100E for injecting and burning ammonia fuel.

[0046] A combustion burner 100E is positioned at the second position P2a. A combustion burner 100C is positioned at the second position P2b, which is downstream of the second position P2a in the flow direction FD. A combustion burner 100A is positioned at the second position P2c, which is downstream of the second position P2b in the flow direction FD.

[0047] The furnace bottom 11f shown in Figure 4 is in the vertical direction VD. combustion This is the lowest part of furnace 11. The flow direction FD distances from furnace bottom 11f to combustion burners 100F, 100D, and 100B are L1a, L1b, and L1c, respectively. The flow direction FD distances from furnace bottom 11f to combustion burners 100E, 100C, and 100A are L2a, L2b, and L2c, respectively.

[0048] As shown in Figure 4, among the multiple first placement positions P1a, P1b, and P1c where the combustion burners 100B, 100D, and 100F that inject fine fuel are located, the first placement position P1a, which is the most upstream in the flow direction FD, is further upstream in the flow direction FD than the second placement position P2a, which is the most upstream in the flow direction FD among the multiple second placement positions P2a, P2b, and P2c where the combustion burners 100A, 100C, and 100E that inject ammonia fuel are located.

[0049] Next, with reference to Figure 5, the control method for the boiler 10 of this embodiment will be described. Figure 5 is a flowchart showing the control method for the boiler 10 according to one embodiment of the present disclosure. Figure 5 shows the control method for the boiler 10 when performing a co-firing operation in which fine fuel is injected from all of the multiple combustion burners 100B, 100D, and 100F, and ammonia fuel is injected from all of the multiple combustion burners 100A, 100C, and 100E.

[0050] In steps S101 and S102, a start operation is performed that switches from a fire extinguishing state, in which no particulate fuel is injected from any of the multiple combustion burners 100B, 100D, and 100F, and no ammonia fuel is injected from any of the multiple combustion burners 100A, 100C, and 100E, to a mixed combustion operation.

[0051] In step S101, the control unit 60 controls the solid fuel adjustment units 31a, 32a, and 33a to start injecting fine fuel from all of the combustion burners 100B, 100D, and 100F. For example, the control unit 60 controls the solid fuel adjustment units 31a, 32a, and 33a to start injecting fine fuel from the upstream side of the combustion gas flow direction FD in the order of combustion burner 100F, combustion burner 100D, and combustion burner 100B.

[0052] In step S102, the control unit 60 controls the ammonia fuel adjustment units 51a, 52a, and 53a to start injecting ammonia fuel from all of the combustion burners 100A, 100C, and 100E. For example, the control unit 60 controls the ammonia fuel adjustment units 51a, 52a, and 53a to start injecting ammonia fuel from the upstream side of the combustion gas flow direction FD in the order of combustion burner 100E, combustion burner 100C, and combustion burner 100A.

[0053] In step S101, injection of fine fuel is started from all of the multiple combustion burners 100B, 100D, and 100F. Subsequently, in step S102, injection of ammonia fuel is started from all of the multiple combustion burners 100A, 100C, and 100E. This results in a mixed-fuel operation in which fuel is injected from all of the combustion burners 100A, 100B, 100C, 100D, 100E, and 100F. In this embodiment, the control unit 60 controls the solid fuel adjustment units 31a, 32a, 33a and the ammonia fuel adjustment units 51a, 52a, 53a so that, for example, the proportion of ammonia fuel is 10% or more and 60% or less in terms of calorific value (calories).

[0054] As shown in Figure 4, the combustion burner 100F is positioned at the upstream end of the flow direction FD. In this manner, the control unit 60 controls the solid fuel adjustment units 31a, 32a, 33a and the ammonia fuel adjustment units 51a, 52a, 53a so that the fuel injected at the upstream end of the flow direction FD becomes pulverized fuel during co-firing operation.

[0055] The reason for initiating the injection of pulverized fuel in step S101, and then initiating the injection of ammonia fuel in step S102, is to bring the ambient temperature at the second placement positions P2a, P2b, and P2c where the combustion burners 100A, 100C, and 100E are located to a temperature sufficient for the combustion of ammonia and the decomposition of nitrous oxide produced during the ammonia combustion process.

[0056] When executing the startup operations of steps S101 and S102, the control unit 60 controls the solid fuel adjustment units 31a, 32a, and 33a so that the ambient temperature at the second placement positions P2a, P2b, and P2c where the combustion burners 100A, 100C, and 100E are located becomes 1000°C or higher at the timing when the supply of ammonia fuel to the combustion burners 100A, 100C, and 100E is started.

[0057] For example, when the control unit 60 controls the ammonia fuel adjustment unit 53a to inject ammonia fuel first from combustion burner 100E among combustion burners 100A, 100C, and 100E, it adjusts the solid fuel adjustment unit 33a so that the ambient temperature at the second position P2a where combustion burner 100E is located becomes 1000°C or higher. In this case, the control unit 60 injects fine fuel from combustion burner 100F prior to the injection of ammonia fuel from combustion burner 100E, and controls the system to inject ammonia fuel from combustion burner 100E after the ambient temperature at the second position P2a has reached 1000°C or higher.

[0058] The reason for setting the ambient temperature at the second placement positions P2a, P2b, and P2c to 1000°C or higher is to sufficiently promote the combustion of ammonia contained in the ammonia fuel and the decomposition of nitrous oxide produced during the ammonia combustion process. Since the decomposition of nitrous oxide is rapidly promoted when the ambient temperature exceeds 900°C, it is preferable to set it to 1000°C or higher to ensure sufficient decomposition. Furthermore, it is more preferable to set the ambient temperature at the second placement positions P2a, P2b, and P2c to 1100°C or higher, and even more preferable to 1200°C or higher.

[0059] Figure 6 shows combustion This figure shows the relationship between the distance from the furnace bottom 11f of furnace 11 and the temperature. In the example shown in Figure 6, fine fuel is supplied from all of the combustion burners 100B, 100D, and 100F. combustion The ammonia fuel is injected into furnace 11 and supplied from all combustion burners 100A, 100C, and 100E. combustion The system is operating in a co-firing configuration, injecting fuel into furnace 11.

[0060] As shown in Figure 6, when the distance from the furnace bottom 11f exceeds L2a, which is the distance to the second position P2a where the combustion burner 100E that injects ammonia fuel is located, combustion The ambient temperature inside the furnace 11 exceeds 1400°C. Also, when the distance from the furnace bottom 11f exceeds L1c, which is the distance to the first position P1c where the combustion burner 100B that injects the fine fuel is located, combustion The ambient temperature inside furnace 11 becomes close to 1600°C.

[0061] Under the operating conditions shown in Figure 6, the ambient temperature at the second placement positions P2a, P2b, and P2c where the combustion burners 100A, 100C, and 100E are located will be 1000°C or higher. This will sufficiently promote the combustion of ammonia contained in the ammonia fuel injected from the combustion burners 100A, 100C, and 100E, as well as the decomposition of nitrous oxide produced during the ammonia combustion process.

[0062] In the co-firing operation described above, fine fuel injection is initiated from all of the combustion burners 100B, 100D, and 100F, and then in step S102, ammonia fuel injection is initiated from all of the combustion burners 100A, 100C, and 100E. However, other co-firing operations are also possible.

[0063] For example, the injection of fine fuel may be started from at least one of the multiple combustion burners 100B, 100D, and 100F, and then in step S102, the injection of ammonia fuel may be started from at least one of the multiple combustion burners 100A, 100C, and 100E.

[0064] In this case, the control unit 60 controls the solid fuel adjustment units 31a, 32a, 33a and the ammonia fuel adjustment units 51a, 52a, 53a so that in co-firing operation, the fuel injected at the upstream end of the flow direction FD is fine fuel. When executing the startup operations of steps S101 and S102, the control unit 60 controls the solid fuel adjustment units 31a, 32a, 33a and the ammonia fuel adjustment units 51a, 52a, 53a so that the timing of starting to supply fine fuel to the combustion burners 100B, 100D, 100F located at the upstream end of the flow direction FD among the multiple first placement positions P1a, P1b, P1c is earlier than the timing of starting to supply ammonia fuel to each of the multiple combustion burners 100A, 100C, 100E.

[0065] In step S103, the control unit 60 determines whether to continue the co-firing operation. If it is YES, it proceeds to step S104; otherwise, it proceeds to step S106.

[0066] In step S104, the control unit 60 controls the solid fuel adjustment units 31a, 32a, and 33a to adjust the amount of fine fuel injected from the combustion burners 100B, 100D, and 100F. In step S105, the control unit 60 controls the ammonia fuel adjustment units 51a, 52a, and 52a to adjust the amount of ammonia fuel injected from the combustion burners 100A, 100C, and 100E.

[0067] When executing steps S104 and S105, the control unit 60 controls the solid fuel adjustment units 31a, 32a, 33a and the ammonia fuel adjustment units 51a, 52a, 53a so that the ambient temperature at the second placement positions P2a, P2b, P2c where the combustion burners 100A, 100C, 100E are located is 1000°C or higher.

[0068] In step S106, the control unit 60 controls the ammonia fuel adjustment units 51a, 52a, and 53a to stop the injection of ammonia fuel from the multiple combustion burners 100A, 100C, and 100E. For example, the control unit 60 controls the ammonia fuel adjustment units 51a, 52a, and 53a to stop the injection of ammonia fuel in the order of combustion burner 100A, combustion burner 100C, and combustion burner 100E, starting from the downstream side of the combustion gas flow direction FD.

[0069] In step S107, the control unit 60 controls the solid fuel adjustment units 31a, 32a, and 33a to stop the injection of fine fuel from the multiple combustion burners 100B, 100D, and 100F. For example, the control unit 60 controls the solid fuel adjustment units 31a, 32a, and 33a to stop the injection of fine fuel from the combustion burner 100B, combustion burner 100D, and combustion burner 100F in the order of downstream side of the combustion gas flow direction FD.

[0070] The reason for stopping the injection of ammonia fuel in step S106, and then stopping the injection of pulverized fuel in step S107, is to maintain the ambient temperature at the second positioning locations P2a, P2b, and P2c where the combustion burners 100A, 100C, and 100E are located at a temperature sufficient for the combustion of ammonia and the decomposition of nitrous oxide produced during the ammonia combustion process. When the injection of ammonia fuel is stopped, the injection of pulverized fuel continues, so the ambient temperature at the second positioning locations P2a, P2b, and P2c can be maintained at a temperature sufficient for the combustion of ammonia and the decomposition of nitrous oxide produced during the ammonia combustion process.

[0071] The functions and effects of the boiler 10 of this embodiment, as described above, will now be explained. In the boiler 10 of this embodiment, when performing a co-firing operation in which solid fuel is injected from at least one of the multiple combustion burners 100B, 100D, and 100F, and ammonia fuel is injected from at least one of the multiple combustion burners 100A, 100C, and 100E, the fuel injected at the upstream end of the flow direction FD through which the combustion gas flows becomes pulverized fuel. Since the combustion gas generated by the combustion of the pulverized fuel flows from the upstream to the downstream end of the flow direction FD, the ambient temperature at the second position where the combustion burners 100A, 100C, and 100E are located rises compared to when there is no combustion gas flow, and the combustion of ammonia fuel and the decomposition of nitrous oxide are promoted. In addition, since the ammonia fuel is guided from the upstream to the downstream end of the flow direction FD by the flow of combustion gas, it is possible to appropriately prevent unburned ammonia and nitrous oxide from accumulating on the upstream side in a predetermined direction.

[0072] In the boiler 10 of this embodiment, the first position P1a of the combustion burner 100F, which is located on the upstream side of the flow direction FD and injects pulverized fuel, is upstream of the second position P2a of the combustion burner 100E, which is located on the upstream side of the flow direction FD and injects ammonia fuel. Therefore, even when pulverized fuel is injected from all combustion burners 100B, 100D, and 100F, and ammonia fuel is injected from all combustion burners 100A, 100C, and 100E, the fuel injected at the upstream side of the flow direction FD through which the combustion gas flows will be pulverized fuel. As a result, the ambient temperature at the second position where the combustion burners 100A, 100C, and 100E are located rises, promoting the combustion of ammonia fuel and the decomposition of nitrous oxide. Furthermore, since the ammonia fuel is guided from the upstream side to the downstream side of the flow direction FD by the flow of combustion gas, it is possible to appropriately prevent the accumulation of unburned ammonia and nitrous oxide on the upstream side of the flow direction FD.

[0073] According to the boiler 10 of this embodiment, when performing the startup operation, the timing at which the supply of pulverized fuel begins to the combustion burner 100F located on the upstream side of the flow direction FD among the multiple first placement positions P1a, P1b, P1c is earlier than the timing at which the supply of ammonia fuel begins to any of the multiple combustion burners 100A, 100C, 100E. Therefore, at the timing at which the supply of ammonia fuel begins to any of the multiple combustion burners 100A, 100C, 100E, the combustion gas generated by the combustion of pulverized fuel flows from the upstream side to the downstream side of the flow direction FD.

[0074] Furthermore, the combustion burner that injects fine fuel (ignition operation) during startup only needs to be located upstream of the combustion burner that injects ammonia fuel in the flow direction FD. The combustion burner that injects fine fuel during startup may be the combustion burner 100F located at the lowest stage in the vertical direction VD of the boiler 10, or, if combustion burner 100F is not used during startup, it may be another combustion burner located downstream of it in the flow direction FD.

[0075] As a result, the ambient temperature at the location where the combustion burners 100A, 100C, and 100E are positioned rises compared to when there is no combustion gas flow, promoting the combustion of ammonia fuel and the decomposition of nitrous oxide. In addition, because the ammonia fuel is guided from the upstream side to the downstream side of the flow direction FD by the combustion gas flow, it is possible to effectively prevent the accumulation of unburned ammonia and nitrous oxide on the upstream side of the flow direction FD.

[0076] According to the boiler 10 of this embodiment, at the timing when the supply of ammonia fuel to the combustion burners 100A, 100C, and 100E is started, the ambient temperature at the second positioning positions P2a, P2b, and P2c where the combustion burners 100A, 100C, and 100E are located becomes 1000°C or higher, thereby ensuring reliable combustion of the ammonia fuel and reliably promoting the decomposition of nitrous oxide.

[0077] [First variation] In the above description, the combustion burner located furthest downstream in the flow direction FD was defined as combustion burner 100A, which injects ammonia fuel. However, other configurations are also possible. For example, combustion burner 100A may be removed from the combustion apparatus 12 of the boiler 10 shown in Figure 4, and the combustion burner located furthest downstream in the flow direction FD may be combustion burner 100B, which injects pulverized fuel. In this case, among the multiple first placement positions P1a, P1b, and P1c where combustion burners 100B, 100D, and 100F are located, the first placement position P1c, which is furthest downstream in the flow direction FD, is further downstream in the flow direction FD than the second placement position P2b, which is furthest downstream in the flow direction FD among the multiple second placement positions P2a and P2b where combustion burners 100C and 100E are located.

[0078] With the boiler 10 described above, the first position P1c of the combustion burner 100B, which is located at the downstream end of the flow direction FD and injects pulverized fuel, is located downstream of the second position P2b of the combustion burner 100C, which is located at the downstream end of the flow direction FD and injects ammonia fuel. Therefore, it is possible to ensure sufficient combustion time for the ammonia fuel injected from the combustion burner 100C and prevent unburned ammonia fuel and nitrous oxide from flowing out to the downstream side of the flow direction FD without being decomposed.

[0079] Furthermore, the combustion burner that injects (ignites) the pulverized fuel only needs to be positioned downstream in the flow direction FD from the combustion burner that injects the ammonia fuel. The combustion burner that injects the pulverized fuel may be the combustion burner 100B installed at the top of the vertical direction VD of the boiler 10, or, if combustion burner 100B is not used, it may be another combustion burner positioned upstream of it in the flow direction FD.

[0080] [Second variation] In the above description, the control unit 60 is assumed to perform co-firing operation by injecting fine fuel from all of the multiple combustion burners 100B, 100D, and 100F, and injecting ammonia fuel from all of the multiple combustion burners 100A, 100C, and 100E. However, other configurations are also possible. For example, the control unit 60 may perform co-firing operation without injecting fine fuel from at least one of the multiple combustion burners 100B, 100D, and 100F, and without injecting ammonia fuel from at least one of the multiple combustion burners 100A, 100C, and 100E. Such co-firing operation is performed, for example, when operating the boiler 10 at a partial load lower than the rated load.

[0081] The control unit 60 may, for example, perform a co-firing operation in which ammonia fuel is injected only from combustion burner 100E among combustion burners 100A, 100C, and 100E, and fine fuel is injected only from combustion burner 100F among combustion burners 100B, 100D, and 100F. In this case, the control unit 60 controls the injection of fine fuel from combustion burner 100F prior to the injection of ammonia fuel from combustion burner 100E, and then injects ammonia fuel from combustion burner 100E after the ambient temperature at the second position P2a reaches 1000°C or higher.

[0082] Each embodiment described above Combustion furnace, Boilers, power generation equipment, and combustion The reactor control method can be understood, for example, as follows: The first aspect of this disclosure combustion The furnace is capable of co-firing ammonia fuel containing ammonia and a first fuel different from the ammonia fuel, and at each of the multiple first placement positions (P1a, P1b, P1c) arranged at intervals in a predetermined direction (VD), multiple points around the axis combustion Multiple first fuel burners (100B, 100D, 100F) that inject and burn the first fuel into the furnace, and at each of the second positioning positions (P2a, P2b, P2c) which are spaced apart in the predetermined direction and different from the first positioning positions, the first fuel is released from multiple points around the axis. combustionThe reactor comprises a plurality of ammonia fuel burners (100A, 100C, 100E) for injecting and burning ammonia fuel into the reactor, a first fuel adjustment unit (31a, 32a, 33a) for adjusting the supply amount of the first fuel supplied to the first fuel burner, an ammonia fuel adjustment unit (51a, 52a, 53a) for adjusting the supply amount of the ammonia fuel supplied to the ammonia fuel burner, and a control unit (60) for controlling the first fuel adjustment unit and the ammonia fuel adjustment unit, wherein the combustion gas generated by the combustion of the first fuel and the ammonia fuel is used combustion A boiler (10) that flows fuel in a predetermined direction in a furnace and discharges it to the outside, wherein the control unit controls the first fuel adjustment unit and the ammonia fuel adjustment unit so that the fuel injected at the upstream end in the predetermined direction becomes the first fuel when performing a co-firing operation in which the first fuel is injected from at least one of the plurality of first fuel burners and the ammonia fuel is injected from at least one of the plurality of ammonia fuel burners.

[0083] The first aspect of this disclosure combustion In the furnace, when performing a co-firing operation in which a first fuel is injected from at least one of the multiple first fuel burners and ammonia fuel is injected from at least one of the multiple ammonia fuel burners, the fuel injected at the upstream end of a predetermined direction in which the combustion gas flows becomes the first fuel. Because the combustion gas generated by the combustion of the first fuel flows from the upstream end to the downstream end of the predetermined direction, the ambient temperature at the second position where the ammonia fuel burner is located rises compared to when there is no combustion gas flow, promoting the combustion of ammonia fuel and the decomposition of ammonia and nitrous oxide. In addition, because the ammonia fuel is guided from the upstream end to the downstream end of the predetermined direction by the flow of combustion gas, it is possible to appropriately prevent the accumulation of unburned ammonia and nitrous oxide on the upstream side of the predetermined direction.

[0084] The second aspect of this disclosure combustionIn the first embodiment, the furnace further comprises the following configuration: that, among the plurality of first placement positions in which the first fuel burner is located, the upstreammost position in the predetermined direction is further upstream in the predetermined direction than the upstreammost position in the plurality of second placement positions in which the ammonia fuel burner is located.

[0085] The second aspect of this disclosure combustion In this reactor, the first position of the first fuel burner, located at the upstream end of a predetermined direction, is upstream of the second position of the ammonia fuel burner, also located at the upstream end of a predetermined direction. Therefore, even when first fuel is injected from all first fuel burners and ammonia fuel is injected from all ammonia fuel burners, the fuel injected at the upstream end of the predetermined direction through which the combustion gas flows is the first fuel. This effectively prevents the accumulation of unburned ammonia and nitrous oxide upstream of the predetermined direction.

[0086] The third aspect of this disclosure combustion In a second embodiment, the furnace further comprises the following configuration. That is, when the control unit performs a startup operation to switch from a fire extinguishing state in which the first fuel is not injected from all of the plurality of first fuel burners and the ammonia fuel is not injected from all of the plurality of ammonia fuel burners to the co-firing operation, the control unit controls the first fuel adjustment unit and the ammonia fuel adjustment unit so that the timing at which the supply of the first fuel is started to the first fuel burner located on the upstream side in the predetermined direction among the plurality of first arrangement positions of the first fuel burners to be started is earlier than the timing at which the supply of the ammonia fuel is started to each of the plurality of ammonia fuel burners.

[0087] The third aspect of this disclosure combustionAccording to the reactor, when the startup operation is performed, the timing at which the supply of the first fuel begins to the first fuel burner located furthest upstream in a predetermined direction among multiple first placement positions is earlier than the timing at which the supply of ammonia fuel begins to each of the multiple ammonia fuel burners. Therefore, at the timing at which the supply of ammonia fuel begins to each of the multiple ammonia fuel burners, the combustion gas generated by the combustion of the first fuel flows from the upstream side to the downstream side in the predetermined direction. As a result, the ambient temperature at the location where the ammonia fuel burners are placed rises compared to when there is no flow of combustion gas, and the combustion of ammonia fuel is promoted. In addition, because the ammonia fuel is guided from the upstream side to the downstream side in the predetermined direction by the flow of combustion gas, it is possible to appropriately prevent the accumulation of unburned ammonia and nitrous oxide on the upstream side in the predetermined direction.

[0088] The fourth aspect of this disclosure combustion In a third embodiment, the furnace further comprises the following configuration: When the start operation is performed, the control unit controls the first fuel adjustment unit and the ammonia fuel adjustment unit so that the ambient temperature at the second position where the ammonia fuel burner is located is 1000°C or higher at the timing when the supply of the ammonia fuel to the ammonia fuel burner is started.

[0089] The fourth aspect of this disclosure combustion According to the reactor, at the moment when the supply of ammonia fuel to the ammonia fuel burner begins, the ambient temperature at the second position where the ammonia fuel burner is located will be 1000°C or higher, thus ensuring reliable combustion of the ammonia fuel and reliably promoting the decomposition of nitrous oxide.

[0090] The fifth aspect of this disclosure combustionIn any of the first to fourth embodiments, the furnace further comprises the following configuration: that, among the plurality of first placement positions in which the first fuel burner is located, the position furthest downstream in the predetermined direction is further downstream in the predetermined direction than the position furthest downstream in the plurality of second placement positions in which the ammonia fuel burner is located.

[0091] The fifth aspect of this disclosure combustion According to the reactor, the first position of the first fuel burner, which is located at the downstream end in a predetermined direction, is downstream of the second position of the ammonia fuel burner, which is also located at the downstream end in a predetermined direction. This ensures sufficient burning time for the ammonia fuel and prevents unburned ammonia fuel and nitrous oxide from flowing downstream in the predetermined direction.

[0092] The sixth aspect of this disclosure combustion In any of the first to fourth embodiments, the furnace further comprises the following configuration: The control unit performs the co-firing operation without injecting the first fuel from at least one of the plurality of first fuel burners and without injecting the ammonia fuel from at least one of the plurality of ammonia fuel burners.

[0093] The sixth aspect of this disclosure combustion According to the reactor, even when co-firing is performed at partial load in which first fuel is not injected from at least one of the multiple first fuel burners and ammonia fuel is not injected from at least one of the multiple ammonia fuel burners, it is possible to adequately prevent unburned ammonia and nitrous oxide from accumulating on the upstream side in a predetermined direction.

[0094] A boiler relating to the seventh aspect of this disclosure is one of the boilers described above. combustion It is equipped with a furnace.

[0095] The power generation equipment relating to the eighth aspect of this disclosure is any of the first to fourth aspects. combustionThe system comprises a boiler equipped with a furnace, a steam turbine driven by steam generated in the boiler, and a generator connected to the steam turbine.

[0096] According to the power generation equipment of the eighth aspect of this disclosure, by changing the amount of ammonia fuel supplied to the ammonia fuel burner, the load change rate of the boiler can be increased compared to the case where only the supply amount of the first fuel is changed.

[0097] The ninth aspect of this disclosure combustion In a reactor control method, combustion The furnace is capable of co-firing ammonia fuel containing ammonia and a first fuel different from the ammonia fuel, and at each of the multiple first placement positions arranged at intervals in a predetermined direction, from multiple locations around the axis combustion Multiple first fuel burners that inject and burn the first fuel into the furnace, and at each of the second arrangement positions which are spaced apart in the predetermined direction and different from the first arrangement position, the first fuel is released from multiple locations around the axis. combustion The furnace comprises a plurality of ammonia fuel burners that inject and burn ammonia fuel, a first fuel adjustment unit that adjusts the amount of first fuel supplied to the first fuel burner, and an ammonia fuel adjustment unit that adjusts the amount of ammonia fuel supplied to the ammonia fuel burner, wherein the combustion gas generated by the combustion of the first fuel and the ammonia fuel is combustion The system includes a control step that controls the first fuel adjustment unit and the ammonia fuel adjustment unit so that when performing a co-firing operation in which the fuel is circulated in the furnace in the predetermined direction and discharged to the outside, the first fuel is injected from at least one of the plurality of first fuel burners, and the ammonia fuel is injected from at least one of the plurality of ammonia fuel burners, the fuel injected at the upstream end in the predetermined direction is the first fuel.

[0098] The eighth aspect of this disclosure combustionAccording to the furnace control method, when performing a mixed-combustion operation in which first fuel is injected from at least one of the multiple first fuel burners and ammonia fuel is injected from at least one of the multiple ammonia fuel burners, the fuel injected at the upstream end of a predetermined direction in which the combustion gas flows becomes the first fuel. Since the combustion gas generated by the combustion of the first fuel flows from the upstream to the downstream end of the predetermined direction, the ambient temperature at the location where the ammonia fuel burner is positioned rises compared to when there is no combustion gas flow, and the combustion of the ammonia fuel is promoted. In addition, since the ammonia fuel is guided from the upstream to the downstream end of the predetermined direction by the flow of combustion gas, it is possible to appropriately prevent the accumulation of unburned ammonia and nitrous oxide on the upstream side of the predetermined direction. [Explanation of symbols]

[0099] 10 Boilers 11 combustion furnace 11a, 11b, 11c, 11d Wall surfaces 11f hearth bottom 12 Combustion device 13 Flue 26,27,28 Pulverized fuel supply pipe 31, 32, 33 Crusher 31a,32a,33a Solid fuel adjustment section 31b,32b,33b Solid fuel supply pipe 50 Ammonia Fuel Supply Unit 51, 52, 53 Ammonia fuel supply pipes 51a, 52a, 53a Ammonia fuel adjustment section 60 Control Unit 100A, 100C, 100E Combustion Burner (Ammonia Fuel Burner) 100B, 100D, 100F Combustion Burner (Solid Fuel Burner) 110a, 110b, 110c, 110d Ammonia fuel burner 120a, 120b, 120c, 120d Solid Fuel Burner FD flow direction P1a,P1b,P1c 1st placement position P2a, P2b, P2c Second configuration position VD Vertical direction Z-axis

Claims

1. A combustion furnace capable of co-firing an ammonia fuel containing ammonia and a first fuel different from the ammonia fuel, Multiple first fuel burners that inject the first fuel into the incinerator from multiple locations at each of multiple first placement positions arranged at intervals in a predetermined direction and burn it, A plurality of ammonia fuel burners are arranged at intervals in the predetermined direction and inject the ammonia fuel into the incinerator from multiple locations at each of the second arrangement positions which are different from the first arrangement positions for combustion. A first fuel adjustment unit that adjusts the amount of the first fuel supplied to the first fuel burner, an ammonia fuel adjustment unit that adjusts the amount of ammonia fuel supplied to the ammonia fuel burner, The system comprises a control unit that controls the first fuel adjustment unit and the ammonia fuel adjustment unit, A boiler that circulates the combustion gas generated by the combustion of the first fuel and the ammonia fuel in the incinerator in the predetermined direction and discharges it to the outside, The control unit controls the first fuel adjustment unit and the ammonia fuel adjustment unit so that when performing a co-firing operation in which the first fuel is injected from at least one of the plurality of first fuel burners and the ammonia fuel is injected from at least one of the plurality of ammonia fuel burners, the fuel injected at the upstream end in the predetermined direction becomes the first fuel.

2. The combustion furnace according to claim 1, wherein the upstreammost position in the predetermined direction among the plurality of first arrangement positions in which the first fuel burner is arranged is further upstream in the predetermined direction than the upstreammost position in the predetermined direction among the plurality of second arrangement positions in which the ammonia fuel burner is arranged.

3. The combustion furnace according to claim 2, wherein the control unit, when performing a startup operation to switch from a fire extinguishing state in which no first fuel is injected from any of the plurality of first fuel burners and no ammonia fuel is injected from any of the plurality of ammonia fuel burners to the co-firing operation, controls the first fuel adjustment unit and the ammonia fuel adjustment unit to start supplying the first fuel to the first fuel burner located on the upstream side in the predetermined direction among the plurality of first arrangement positions of the first fuel burners to be started earlier than the timing at which supplying the ammonia fuel to each of the plurality of ammonia fuel burners to start.

4. The combustion furnace according to claim 3, wherein the control unit controls the first fuel adjustment unit and the ammonia fuel adjustment unit so that the ambient temperature at the second position where the ammonia fuel burner is located becomes 1000°C or higher at the timing when the supply of the ammonia fuel to the ammonia fuel burner is started when the start operation is performed.

5. The combustion furnace according to any one of claims 1 to 4, wherein the most downstream position in the predetermined direction among the plurality of first arrangement positions in which the first fuel burner is arranged is further downstream in the predetermined direction than the most downstream position in the predetermined direction among the plurality of second arrangement positions in which the ammonia fuel burner is arranged.

6. The combustion furnace according to any one of claims 1 to 4, wherein the control unit performs the co-firing operation without injecting the first fuel from at least one of the plurality of first fuel burners and without injecting the ammonia fuel from at least one of the plurality of ammonia fuel burners.

7. A boiler comprising a combustion furnace according to any one of claims 1 to 4.

8. A boiler comprising a combustion furnace according to any one of claims 1 to 4, A steam turbine driven by steam generated in the aforementioned boiler, A power generation facility comprising a generator connected to the steam turbine.

9. A control method for an incinerator capable of co-firing an ammonia fuel containing ammonia and a first fuel different from the ammonia fuel, The aforementioned incinerator, A plurality of first fuel burners that inject the first fuel into the incinerator from multiple locations at each of a plurality of first placement positions arranged at intervals in a predetermined direction and burn it, A plurality of ammonia fuel burners are arranged at intervals in the predetermined direction and inject the ammonia fuel into the incinerator from multiple locations at each of the second arrangement positions which are different from the first arrangement positions for combustion. A first fuel adjustment unit that adjusts the amount of the first fuel supplied to the first fuel burner, The system includes an ammonia fuel adjustment unit that adjusts the amount of ammonia fuel supplied to the ammonia fuel burner, The combustion gas generated by the combustion of the first fuel and the ammonia fuel is circulated in the incinerator in the predetermined direction and discharged to the outside. A control method for an incinerator, comprising a control step of controlling the first fuel adjustment unit and the ammonia fuel adjustment unit so that the fuel injected at the upstream end in a predetermined direction becomes the first fuel when performing a co-firing operation in which the first fuel is injected from at least one of the plurality of first fuel burners and the ammonia fuel is injected from at least one of the plurality of ammonia fuel burners.

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