Burner and boiler comprising the same

Abstract

To provide a burner in which both liquefied gas fuel and oil fuel can be used with a simple structure.SOLUTION: In a burner 21, liquefied ammonia fuel L and oil fuel are used by switching between them. The burner 21 comprises a burner gun 60 comprising a nozzle 67 for injecting the liquefied ammonia fuel L and / or the oil fuel, and an atomizing gas conveying pipe for supplying atomizing gas for atomizing the oil fuel injected from the nozzle 67, to the nozzle 67. The atomizing gas conveying pipe is provided with an atomizing gas closing member 92 capable of blocking the flow of the atomizing gas.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a burner that burns a liquefied gas fuel, such as a liquefied ammonia fuel, and a boiler equipped with the burner. [Background technology]

[0002] Large boilers, such as power generation boilers, have a hollow furnace that is installed vertically, with multiple burners disposed on the furnace wall. Large boilers also have a flue connected vertically above the furnace, with a heat exchanger disposed in the flue for generating steam. The burner then injects a mixture of fuel and air (oxidizing gas) into the furnace, forming a flame, generating combustion gas that flows down the flue. A heat exchanger is installed in the area where the combustion gas flows, and superheated steam is generated by heating water or steam flowing through the heat transfer tubes that make up the heat exchanger.

[0003] As disclosed in Patent Document 1, for example, a boiler that burns oil fuel such as heavy oil or light oil is equipped with a burner that atomizes oil fuel supplied from outside the boiler using an atomizing medium such as air or steam and injects the atomized fuel into the boiler furnace. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-96590 Summary of the Invention [Problem to be solved by the invention]

[0005] When studying a burner that supplies liquefied gas fuel such as liquefied ammonia fuel as a liquid fuel, the inventors considered the possibility of using it in combination with an oil fuel burner gun that supplies oil fuel. However, the oil fuel burner gun and the liquefied gas fuel burner gun may have different injection nozzle hole diameters to achieve the desired injection amount, so they may not be compatible. It is also possible to use the burner opening of the furnace for both purposes and replace only the burner gun depending on the fuel being used, but when using a liquefied gas fuel burner gun, there is a risk of oil fuel or atomization gas leaking from the piping that supplies the oil fuel and the piping that supplies the atomization gas (atomization medium such as air or steam) required for oil fuel. Therefore, a simple configuration is required that allows safe and easy switching when switching between liquefied gas fuel and oil fuel.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a burner that can be used for both liquefied gas fuel and oil fuel with a simple configuration, and a boiler equipped with the same. [Means for solving the problem]

[0007] A burner according to one embodiment of the present disclosure is a burner that can be used by switching between liquefied gas fuel and oil fuel, and is equipped with a burner gun having a nozzle that sprays liquefied gas fuel and / or oil fuel, and an atomization gas supply path that supplies atomization gas to the nozzle for atomizing the oil fuel sprayed from the nozzle, and is provided with an atomization gas closing member that can block the flow of atomization gas flowing through the atomization gas supply path.

[0008] A boiler according to one aspect of the present disclosure includes the burner described above. [Effects of the Invention]

[0009] The fuel cell can be used for both liquefied gas fuel and oil fuel with a simple configuration. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a schematic configuration diagram showing a boiler according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a vertical cross-sectional view showing the burner of FIG. [Figure 3] 3 is an enlarged longitudinal cross-sectional view showing the periphery of the pipe connecting member of FIG. 2. FIG. [Figure 4] FIG. 1 is a schematic diagram showing the supply paths of liquefied ammonia fuel, oil fuel, and steam to a burner gun when oil fuel is used. [Figure 5] FIG. 2 is a schematic diagram showing the supply paths of liquefied ammonia fuel, oil fuel, and steam to a burner gun when liquefied ammonia fuel is used. [Figure 6] FIG. 2 is a vertical cross-sectional view showing the burner of FIG. 1 when liquefied ammonia fuel is used. [Figure 7] 7 is an enlarged longitudinal cross-sectional view showing the periphery of the pipe connecting member of FIG. 6. FIG. [Figure 8] FIG. 10 is a schematic configuration diagram showing supply paths of liquefied ammonia fuel, oil fuel, and steam to a burner gun when liquefied ammonia fuel is used according to a second embodiment of the present disclosure. [Figure 9] FIG. 1 is a vertical cross-sectional view showing a burner using a burner gun that uses liquefied ammonia fuel. [Figure 10] FIG. 10 is a vertical cross-sectional view showing the burner gun of FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to this embodiment, and when there are multiple embodiments, it also includes configurations that combine the embodiments. In the following description, "up" and "upper" refer to the upper side in the vertical direction, and "lower" and "lower" refer to the lower side in the vertical direction, and the vertical direction is not precise and may include errors.

[0012] [First embodiment] FIG. 1 shows a boiler 10 according to a first embodiment that is capable of burning liquefied ammonia (NH3) fuel. The boiler 10 of this embodiment is a boiler that can burn liquefied ammonia fuel, pulverized fuel made by pulverizing solid fuel (coal or biomass fuel), or oil fuel such as heavy oil using a burner, and exchange the heat generated by this combustion with feedwater or steam to generate superheated steam.

[0013] The boiler 10 has a furnace 11, a combustion device 20, and a combustion gas passage 12. The furnace 11 has a hollow rectangular cylindrical shape and is installed vertically. The furnace wall 101 that forms the inner wall surface of the furnace 11 is composed of a plurality of heat transfer tubes and fins that connect the heat transfer tubes together, and recovers the heat generated by the combustion of pulverized fuel by heat exchange with water and steam circulating inside the heat transfer tubes, while suppressing the temperature rise of the furnace wall 101.

[0014] The combustion device 20 is installed in the lower region of the furnace 11. In this embodiment, the combustion device 20 has a plurality of burners 21A, 21B, 21C, 21D, 21E, and 21F (hereinafter, when these burners are not to be distinguished, they will be simply referred to as "burners 21") attached to the furnace wall 101. The burners 21 are arranged at equal intervals in the furnace width direction along the furnace wall 101 (for example, they are arranged in the furnace width direction so as to face each other on the opposing furnace walls 101 for opposed combustion), and are arranged in multiple stages along the vertical direction. The shape of the furnace, the number of burner stages, the number of burners per stage, the arrangement of the burners, etc. are not limited to this embodiment.

[0015] Burners 21A, 21B, 21C, 21D, 21E, and 21F are connected to a plurality of mills (pulverizers) 31A, 31B, 31C, 31D, 31E, and 31F (hereinafter, when these mills are not distinguished, they will be simply referred to as "mills 31") via a plurality of pulverized fuel supply pipes 22A, 22B, 22C, 22D, 22E, and 22F, respectively (hereinafter, when these mills are not distinguished, they will be simply referred to as "mills 31"). Mill 31 is, for example, a vertical roller mill having a rotatable grinding table (not shown) supported therein and a plurality of grinding rollers (not shown) supported above the grinding table so that they can rotate in conjunction with the rotation of the grinding table. The solid fuel pulverized by the cooperation of the grinding rollers and the grinding table is transported to a classifier (not shown) provided in mill 31 by primary air (carrier gas, oxidizing gas) supplied to mill 31. The classifier separates the pulverized fuel into pulverized fuel having a particle size smaller than that suitable for combustion in the burner 21 and coarse pulverized fuel having a particle size larger than that. The pulverized fuel passes through the classifier and is supplied to the burner 21 together with primary air via the pulverized fuel supply pipe 22. The coarse pulverized fuel that does not pass through the classifier falls onto the grinding table inside the mill 31 under its own weight and is re-ground.

[0016] At least some of the burners 21A, 21B, 21C, 21D, 21E, and 21F are ammonia-fired burners that are supplied with liquefied ammonia fuel. In this case, the other burners 21A, 21B, 21C, 21D, 21E, and 21F are pulverized coal-fired burners. The ammonia-fired burners are not supplied with pulverized coal fuel from the mill 31, but are supplied with liquefied ammonia fuel from the liquefied ammonia supply source 50.

[0017] An air register 23 is provided outside the furnace 11 at the installation position of the burner 21, and one end of an air duct 24 is connected to the air register 23. A forced draft fan (FDF) 32 is connected to the other end of the air duct 24. The air supplied from the forced draft fan 32 is heated by an air preheater 42 installed in the air duct 24 and is supplied to the burner 21 via the air register 23 as secondary air (combustion air, oxidizing gas) and introduced into the furnace 11.

[0018] The combustion gas passage 12 is connected to the vertical upper part of the furnace 11. The combustion gas passage 12 is provided with superheaters 102A, 102B, and 102C (hereinafter, when there is no need to distinguish between these superheaters, they will simply be referred to as "superheaters 102"), reheaters 103A and 103B (hereinafter, when there is no need to distinguish between these reheaters, they will simply be referred to as "reheater 103"), and a coal economizer 104 as heat exchangers for recovering heat from the combustion gas, and heat is exchanged between the combustion gas generated in the furnace 11 and feedwater or steam circulating inside each heat exchanger. Note that the arrangement and shape of each heat exchanger are not limited to those shown in FIG. 1.

[0019] A flue 13 is connected to the downstream side of the combustion gas passage 12, and discharges the combustion gas whose heat has been recovered by the heat exchanger. An air preheater (air heater) 42 is provided between the flue 13 and the air duct 24, and heat is exchanged between the air flowing through the air duct 24 and the combustion gas flowing through the flue 13, heating the primary air supplied to the mill 31 and the secondary air supplied to the burner 21, thereby recovering further heat from the combustion gas after heat exchange with water and steam.

[0020] Furthermore, a denitration device 43 may be provided in the flue 13 at a position upstream of the air preheater 42. The denitration device 43 supplies a reducing agent, such as ammonia or urea water, which has the effect of reducing nitrogen oxides, to the combustion gas flowing through the flue 13, and promotes the reaction between the nitrogen oxides (NOx) in the combustion gas to which the reducing agent has been supplied and the reducing agent by the catalytic action of a denitration catalyst provided in the denitration device 43, thereby removing and reducing the nitrogen oxides in the combustion gas.

[0021] A gas duct 41 is connected to the flue 13 downstream of the air preheater 42. The gas duct 41 is provided with environmental equipment such as a dust collector 44, such as an electrostatic precipitator, that removes ash and the like from the combustion gas, and a desulfurization equipment 46 that removes sulfur oxides, as well as an induced draft fan (IDF) 45 that guides the exhaust gas to these environmental equipment. The downstream end of the gas duct 41 is connected to a chimney 47, and the combustion gas treated in the environmental equipment is discharged to the outside of the system as exhaust gas.

[0022] When the boiler 10 is performing mono-combustion of pulverized fuel (or co-combustion with ammonia fuel), the multiple mills 31 are driven, and pulverized and classified pulverized fuel is supplied to the burner 21 together with primary air via the pulverized fuel supply pipe 22. Secondary air heated by the air preheater 42 is supplied to the burner 21 from the air duct 24 via the wind box 23. The burner 21 blows a pulverized fuel mixture, which is a mixture of pulverized fuel and primary air, into the furnace 11, and also blows secondary air into the furnace 11. The pulverized fuel mixture blown into the furnace 11 ignites and reacts with the secondary air to form a flame. A flame is formed in the lower region of the furnace 11, and high-temperature combustion gas rises within the furnace 11 and flows into the combustion gas passage 12. In this embodiment, air is used as the oxidizing gas (primary air, secondary air), but the oxidizing gas may have a higher or lower oxygen content than air, and stable combustion can be achieved in the furnace 11 by adjusting the ratio of the amount of oxygen to the amount of fuel supplied within an appropriate range.

[0023] Additionally, above the mounting position of the burners 21 in the furnace 11, a plurality of additional air ports (AA ports) 25 are provided for supplying additional air for combustion (AA) into the furnace 11. The additional air ports 25 are connected to the ends of additional air ducts (AA ducts) 26 branching off from the air duct 24, and a portion of the air supplied from the forced draft fan 32 can be supplied to the additional air ports 25 via the additional air ducts 26 as additional air for combustion.

[0024] In region A (corresponding to the installation range of the wind box 23 in the height direction) inside the furnace 11 shown in Fig. 1, a flame is formed by combustion of a mixture of primary air, liquefied ammonia fuel and / or pulverized fuel, and secondary air. Here, the air ratio in region A is set to be 1 or less, specifically, the amount of air supplied to the burner 21 (the total amount of primary air and secondary air) is set to be less than the theoretical amount of air relative to the amount of fuel supplied to the burner 21. By doing so, regions A and B (regions between the top of the burner 21 and the bottom of the additional air port 25) inside the furnace 11 become reducing atmospheres, and nitrogen oxides (NOx) generated by combustion are reduced inside the furnace 11. Thereafter, in region C (region above the bottom of the additional air port 25), additional combustion air is supplied from the additional air port 25 to the combustion gas in which NOx has been reduced, completing the combustion. However, the amount of NOx generated is reduced by the reduction effect in regions A and B.

[0025] The combustion gas that has flowed into the combustion gas passage 12 exchanges heat with water and steam in a superheater 102, a reheater 103, and an economizer 104 arranged inside the combustion gas passage 12, and is then discharged into the flue 13, where nitrogen oxides are removed in a denitration device 43, and the gas exchanges heat with primary air and secondary air in an air preheater 42, and is then discharged into the gas duct 41, where ash and the like are removed in a dust collector 44, and sulfur oxides are removed in a desulfurization device 46, and the gas is then discharged to the outside of the system from a chimney 47. Note that the arrangement of the heat exchangers in the combustion gas passage 12 and the arrangement of the devices from the flue 13 to the gas duct 41 with respect to the combustion gas flow do not necessarily have to be in the order described above.

[0026] The boiler 10 is provided with a liquefied ammonia supply source 50. Ammonia is stored in liquid form as ammonia fuel in the liquefied ammonia supply source 50. The liquefied ammonia is supplied from the liquefied ammonia supply source 50 to each burner 21.

[0027] The boiler 10 is provided with an oil fuel supply source 52. Heavy oil or the like is stored in liquid form as oil fuel in the oil fuel supply source 52. The oil fuel is supplied from the oil fuel supply source 52 to each burner 21.

[0028] The control unit is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and computer-readable storage media. A series of processes for realizing various functions is stored in, for example, a storage medium in the form of a program. The CPU reads this program into RAM and executes information processing and arithmetic operations to realize various functions. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0029] FIG. 2 shows a burner 21 that can switch between burning liquefied ammonia fuel and oil fuel.

[0030] The burner 21 is equipped with a burner gun 60. The burner gun 60 is provided at a horizontal distance from the side wall 11s of the furnace 11, and is attached to a wind box front plate 62 that covers the furnace 11 from the outside.

[0031] The burner gun 60 includes an oil fuel transport pipe (oil fuel supply path) 64 for transporting oil fuel F, a steam transport pipe (atomization gas supply path) 65 for transporting steam G for atomizing the oil fuel, a nozzle 67, and a piping connection member (connection part) 69.

[0032] The oil fuel transfer pipe 64 and the steam transfer pipe 65 are each made of, for example, a metal pipe. The base ends 64a, 65a of the oil fuel transfer pipe 64 and the steam transfer pipe 65 are connected to a piping connection member 69, and the tip ends 64b, 65b are connected to a nozzle 67 via flexible hoses 71, 72. The oil fuel transfer pipe 64 and the steam transfer pipe 65 each have straight pipe sections 64s, 65s extending linearly for a certain length on the tip end 64b, 65b side, and U-shaped curved sections 64t, 65t are formed on the base end 64a, 65a side of these straight pipe sections 64s, 65s. These curved sections 64t, 65t allow the base ends 64a, 65a of the oil fuel transfer pipe 64 and the steam transfer pipe 65 to open in the same direction as the tip ends 64b, 65b (leftward in FIG. 2 ).

[0033] The nozzle 67 injects the oil fuel F transported through the oil fuel transport pipe 64 and the steam G transported through the steam transport pipe 65 into the furnace 11.

[0034] Highly elastic flexible hoses 71, 72 are connected between the nozzle 67 and the tips 64b, 65b of the oil fuel transfer pipe 64 and the steam transfer pipe 65. These flexible hoses 71, 72 can be bent in the vertical direction of the furnace 11, which makes it possible to adjust the spray direction of the oil fuel F and steam G from the nozzle 67 in the vertical direction.

[0035] The pipe connection member 69 is made of a metal material with high hardness and high thermal conductivity, such as carbon steel for mechanical structures (S25C), and has a plate shape. The pipe connection member 69 is formed with connection ports 75, 76 to which the base ends 64a, 65a of the oil fuel transfer pipe 64 and the steam transfer pipe 65 are connected, respectively, and pipe insertion holes 77, 78 through which the straight pipe portions 64s, 65s of the oil fuel transfer pipe 64 and the steam transfer pipe 65 are inserted. The connection ports 75, 76 and the pipe insertion holes 77, 78 are formed to penetrate one surface 69f and the other surface 69g of the pipe connection member 69 in the plate thickness direction, respectively. In this embodiment, the connection ports 75, 76 are formed side by side in the vertical direction, and the pipe insertion holes 77, 78 are formed side by side in the horizontal direction.

[0036] An external oil fuel pipe 80 for supplying oil fuel F and an external steam pipe 81 for supplying steam G are detachably connected to the pipe connection member 69 on the other surface 69g side. Ends 80a, 81a of the external oil fuel pipe 80 and the external steam pipe 81 are connected to a connector (connection) 83. The connector 83 is detachably connected to the pipe connection member 69.

[0037] The connecting fitting 83 has fitting connection ports 83a, 83b to which end portions 80a, 81a of the external oil fuel pipe 80 and the external steam pipe 81 are respectively connected. The connecting fitting 83 and the pipe connection member 69 are connected with the connection ports 75, 76 of the connecting fitting 83 facing the fitting connection ports 83a, 83b. The external oil fuel pipe 80 and the external steam pipe 81 are connected to the other surface 69g of the pipe connection member 69 so as to communicate with the connection ports 75, 76, respectively.

[0038] A seal packing 85 is sandwiched between the connecting fitting 83 and the piping connecting member 69 to prevent oil fuel F and steam G from leaking from the connection between the connection ports 75, 76 of the connecting fitting 83 and the fitting connection ports 83a, 83b. The seal packing 85 is made of a rubber-based material, a metal-based material, or the like that is softer than the connecting fitting 83 and the piping connecting member 69.

[0039] To detachably connect the fitting 83 and the pipe connection member 69, a fastening member such as a bolt can be used, but a clamp member 87 as shown in FIG. 3 can also be used. This clamp member 87 has, for example, a U-shape in plan view, and one end 87a is rotatably connected to the fitting 83. With the fitting 83 and the other surface 69g of the pipe connection member 69 facing each other via the seal packing 85, the clamp member 87 engages the other end 87b with the one surface 69f of the pipe connection member 69, and tightens a fastening screw 87c provided on the other end 87b. In this way, the other end 87b presses the one surface 69f of the pipe connection member 69 against the fitting 83, thereby easily connecting the fitting 83 and the pipe connection member 69.

[0040] When the fastening screw 87c of the clamp member 87 is loosened, the other end 87b of the connecting fitting 83 moves away from the one surface 69f of the pipe connecting member 69, causing the clamp member 87 to rotate about the one end 87a. This releases the engagement of the other end 87b with the pipe connecting member 69. This easily releases the connection between the connecting fitting 83 and the pipe connecting member 69.

[0041] As shown in Fig. 2, the burner gun 60 is installed by penetrating the side wall 11s of the furnace 11, with the nozzle 67 facing the interior of the furnace 11 and the piping connection member 69 arranged outside the furnace 11 and the wind box front plate 62. Specifically, the burner gun 60 is inserted from the outside of the furnace 11 and the wind box front plate 62, which is opposite to the inside of the furnace 11, through a through hole 11h formed in the side wall 11s of the furnace 11 and a burner insertion hole 62h formed in the wind box front plate 62. The gap between the burner insertion hole 62h and the burner gun 60 is closed by a plug member 89. In addition, a hood 90 is provided on the outer periphery of the nozzle 67 to guide secondary air (combustion air) around the flame generated by igniting the oil fuel F.

[0042] FIG. 4 shows a system for supplying oil fuel F, steam G, and liquefied ammonia fuel L to the burner gun 60.

[0043] An external oil fuel pipe 80 is connected to the burner gun 60. An oil fuel supply source 52 is connected to the upstream side of the external oil fuel pipe 80, and an on-off valve 80v controlled by the control unit is provided therein.

[0044] An external steam pipe 81 is connected to the burner gun 60. A steam supply source 54 is connected to the external steam pipe 81 on the upstream side, and an on-off valve 81v controlled by the control unit is provided.

[0045] An external ammonia pipe 82 is connected to the liquefied ammonia supply source 50. An on-off valve 82v controlled by the control unit is provided in the external ammonia pipe 82. The downstream end of the external ammonia pipe 82 is connected to the downstream side of the on-off valve 80v of the external oil fuel pipe 80. As a result, the liquefied ammonia fuel L flowing through the external ammonia pipe 82 is guided to the burner gun 60 through the external oil fuel pipe 80.

[0046] <Use of oil fuel F> When burning oil fuel F in the burner 21, the on-off valve 80v of the external oil fuel pipe 80 shown in Fig. 4 is opened, and the on-off valve 82v of the external ammonia pipe 82 is closed. The on-off valve 81v of the external steam pipe 81 is opened. In the figure, the on-off valves 80v, 81v, and 82v are shown as filled in black when they are closed, and as filled in white when they are open (the same applies below).

[0047] As shown in FIG. 4, the oil fuel F and steam G are supplied to the burner gun 60 by controlling the on-off valves 80v, 81v, and 82v.

[0048] 2, in the burner gun 60, oil fuel F and steam G supplied from the outside through an external oil fuel pipe 80 and an external steam pipe 81 are sent to a nozzle 67 via a fitting 83, a pipe connection member 69, an oil fuel transfer pipe 64, a steam transfer pipe 65, and flexible hoses 71 and 72. The sent oil fuel F and steam G are sprayed into the furnace 11 from the nozzle 67 exposed inside the furnace 11, generating a flame.

[0049] <Use of liquefied ammonia fuel L> When burning liquefied ammonia fuel L in the burner 21, as shown in Fig. 5, the on-off valve 80v of the external oil fuel pipe 80 is closed, and the on-off valve 82v of the external ammonia pipe 82 is opened. The on-off valve 81v of the external steam pipe 81 is closed.

[0050] As shown in FIG. 5, the liquefied ammonia fuel L is supplied to the burner gun 60 by controlling the on-off valves 80v, 81v, and 82v.

[0051] 6 and 7, a steam closing member (atomized gas closing member) 92 is installed so as to close the steam transport pipe 65. The steam closing member 92 is detachable.

[0052] The steam closing member 92 is provided to close the steam-side connection port 76 formed in the pipe connection member 69. It may also be provided to close the steam-side fitting connection port 83b of the fitting 83. The steam closing member 92 may be provided separately from the pipe connection member 69, or may be provided integrally therewith.

[0053] 6, in the burner gun 60, liquefied ammonia fuel L supplied from the outside through an external oil fuel pipe 80 is sent to a nozzle 67 via a connector 83, a pipe connection member 69, an oil fuel transfer pipe 64, and a flexible hose 71. The sent liquefied ammonia fuel L is sprayed into the furnace 11 from the nozzle 67 exposed inside the furnace 11, generating a flame.

[0054] The above-described embodiment has the following advantages. A steam shutoff member 92 is provided at the connection port 76 of the pipe connection member 69, which is a path for supplying steam, to block the flow of steam G, so that combustion using liquefied ammonia fuel L can be performed.

[0055] Since the steam shutoff member 92 is detachable from the pipe connection member 69 to which the base end portion 65a of the steam transport pipe 65 is connected, the steam G can be shut off with a simple configuration.

[0056] [Second embodiment] A second embodiment of the present disclosure will be described. This embodiment is different from the burner gun of the first embodiment, but is otherwise similar. Therefore, the same components as those of the first embodiment are designated by the same reference numerals, and their description will be omitted.

[0057] 8, in this embodiment, the liquefied ammonia fuel L is led directly to the burner gun (liquefied gas fuel burner gun) 61 using the external ammonia pipe 82 without using the external oil fuel pipe 80. Therefore, when the burner gun 61 that uses the liquefied ammonia fuel L is used, the on-off valve 80v of the external oil fuel pipe 80 is closed, and the on-off valve 82v of the external ammonia pipe 82 is opened. The on-off valve 81v of the external steam pipe 81 is closed.

[0058] 9 shows a state in which the burner gun 61 is attached to the burner 21. As shown in the figure, the burner gun 61 has a straight ammonia transfer pipe 94 for transferring the liquefied ammonia fuel L, and a tip 94a of the ammonia transfer pipe 94 is connected to a flexible hose 95. The liquefied ammonia fuel L introduced from the flexible hose 95 is injected into the furnace 11 from a nozzle 67.

[0059] A pipe connection member (connection portion) 96 is provided at a base end portion 94b of the ammonia transfer pipe 94. A connection pipe 97 connected to the external ammonia pipe 82 (see FIG. 8) is attached to the pipe connection member 96. The external ammonia pipe 82 is connected to a flange portion 97a of the connection pipe 97.

[0060] The pipe connection member 96 is provided with a closing member 98. The closing member 98 is fixed to and integrated with the pipe connection member 96. The closing member 98 blocks the flow path through which the oil fuel F flows and the flow path through which the steam G flows. Specifically, as shown in FIG. 9, the closing member 98 is attached to the connection fitting 83 and closes the fitting connection ports 83a and 83b. The closing member 98 is attached using a clamp member 87 as shown in FIG. 7.

[0061] Figure 10 shows the burner gun 61 of Figure 9. As can be seen from the figure, the closing member 98 is shown before being connected to the connecting fitting 83. By attaching the burner gun 61 to the boiler 10 as shown in Figure 9, the liquefied ammonia fuel L is burned.

[0062] The above-described embodiment has the following advantages. The burner gun 61 for burning the liquefied ammonia fuel L is used separately from the burner gun 60 of the first embodiment, thereby enabling the combustion of the liquefied ammonia fuel. At this time, the flow of the oil fuel F and the steam G is prevented by using a closing member 98 for closing the oil fuel F and the steam G. This allows only the liquefied ammonia fuel L to be supplied to the burner gun 61, and the combustion of the liquefied ammonia fuel L can be achieved with a simple configuration.

[0063] Since the closing member 98 is detachable from the connecting fitting 83 that connects the external oil fuel piping 80 and the oil fuel transfer pipe 64, the oil fuel F can be closed off with a simple configuration.

[0064] By fixing and integrating the closing member 98 to the piping connection member 96 of the burner gun 61, it is possible to always block the flow of oil fuel F and steam G when using liquefied ammonia fuel L. This makes it possible to switch between liquefied ammonia fuel L and oil fuel F with a simple configuration. It is also effective when the on-off valves 80v, 81v cannot be closed due to some malfunction.

[0065] This embodiment also offers greater design freedom than the first embodiment, because the first embodiment is limited by the oil flow path. Furthermore, this embodiment has a simpler structure than providing an ammonia burner in a separate compartment.

[0066] Although liquefied ammonia fuel is used in each of the above-described embodiments, any other liquefied gas fuel having a boiling point lower than the ambient temperature of use may be used. For example, the present invention can be applied to a burner that injects dimethyl ether (DME) in liquid form. Furthermore, although steam is used as the fluid for atomization, other gases such as air may also be used.

[0067] The burners and boilers including the burners described in the above-described embodiments can be understood, for example, as follows.

[0068] The burner (21) according to the first aspect of the present disclosure is a burner (21) that can be used by switching between liquefied gas fuel (L) and oil fuel (F), and includes a burner gun (60) having a nozzle (67) that sprays the liquefied gas fuel (L) and / or oil fuel (F), and an atomization gas supply path (65) that supplies an atomization gas (G) to the nozzle (67) to atomize the oil fuel (F) sprayed from the nozzle (67), and is provided with an atomization gas closing member (92) that can block the flow of the atomization gas flowing through the atomization gas supply path (65).

[0069] The atomization gas shutoff member is provided to block the flow of atomization gas through the atomization gas supply path, so combustion using liquefied gas fuel can be performed. When using oil fuel, the atomization gas shutoff member is removed and atomization gas is used. This allows for the use of both liquefied gas fuel and oil fuel with a simple configuration. Liquefied gas fuels are fuels with a boiling point below 0°C, such as liquefied ammonia and DME. The atomizing gas may be, for example, steam or air.

[0070] In the burner (21) according to the second aspect of the present disclosure, in the first aspect, the atomized gas supply path (65) comprises an atomized gas transport pipe (65) and a connection part (69) to which the base end of the atomized gas transport pipe is connected and which connects the atomized gas transport pipe to an external gas piping that supplies the atomized gas, and the atomized gas closing member (92) is detachable from the connection part (69).

[0071] Since the atomizing gas shutoff member is detachable from the connection portion where the base end of the atomizing gas transport pipe is connected to the external gas piping, the atomizing gas can be shut off with a simple configuration.

[0072] In the burner (21) according to the third aspect of the present disclosure, in the first or second aspect, the burner gun (60) is used by switching between liquefied gas fuel (F) and oil fuel (G), and is provided with an oil fuel supply path (64) that supplies oil fuel to the nozzle (67), and when liquefied gas fuel (L) is supplied to the oil fuel supply path (64), the atomization gas closing member (92) blocks the flow of atomization gas.

[0073] When using liquefied gas fuel, the atomizing gas shutoff member is used to block the flow of atomizing gas, and the liquefied gas fuel is supplied to the burner gun through the oil fuel supply path. This allows the burner gun to be used for both liquefied gas fuel and oil fuel with a simple configuration.

[0074] The burner (21) according to the fourth aspect of the present disclosure, in the first aspect, comprises an oil fuel burner gun (60) that uses oil fuel and a liquefied gas fuel burner gun (61) that uses liquefied gas fuel as the burner guns, a liquefied gas fuel supply path (94) that supplies liquefied gas fuel (L) to the nozzle (67) of the liquefied gas fuel burner gun (61), and an oil fuel supply path (64) that supplies oil fuel (F) to the nozzle (67) of the oil fuel burner gun (60), and is provided with an oil fuel closing member (98) that can block the flow of oil fuel (F) to the oil fuel supply path (64).

[0075] The use of a liquefied gas fuel burner gun makes it possible to burn liquefied gas fuel. At this time, an oil fuel shutoff member is used to block the flow of oil fuel into the oil fuel supply path. Also, an atomized gas shutoff member is used to block the flow of atomized gas. This allows only liquefied gas fuel to be supplied to the liquefied gas fuel burner gun, making it possible to achieve combustion of liquefied gas fuel with a simple configuration.

[0076] The burner (21) according to a fifth aspect of the present disclosure is the fourth aspect, and includes a connection part (83) that connects an external oil fuel pipe (80) that supplies oil fuel (F) from the outside to the oil fuel supply path (64), and the oil fuel closing member (98) is detachable from the connection part (83).

[0077] Since the oil fuel shutoff member is detachable from the connection portion that connects the external oil fuel pipe and the oil fuel supply path, the oil fuel can be shut off with a simple configuration.

[0078] A burner (21) according to a sixth aspect of the present disclosure is the burner according to claim 5, wherein in the fifth aspect, the oil fuel closing member (98) is fixed to the liquefied gas fuel burner gun (61).

[0079] By fixing and integrating the oil fuel shutoff member to the liquefied gas fuel burner gun, it is possible to always prevent the flow of oil fuel when using liquefied gas fuel, which makes it possible to switch between liquefied gas fuel and oil fuel with a simple configuration. The atomizing gas shutoff member may also be fixed integrally to the liquefied gas fuel burner gun.

[0080] A burner (21) according to a seventh aspect of the present disclosure is the burner (21) of the sixth aspect, wherein the oil fuel closing member (98) is integrated with the atomized gas closing member.

[0081] By integrating the atomized gas blocking member with the oil fuel blocking member, the flow of atomized gas can be blocked at the same time.

[0082] A boiler (10) according to a first aspect of the present disclosure includes any one of the burners (21) described above. [Explanation of symbols]

[0083] 10. Boiler 11 Furnace 11h Through hole 11s side wall 12 Combustion gas passage 13 Flue 20 Combustion equipment 21 Burner 22 Fine fuel supply pipe 23 Wind box 24 Wind road 25 Additional air port 26 Additional air duct 31 mil 32 Forced draft fan 41 Gas duct 42 Air preheater 43 Denitration equipment 44 Dust collection device 46 Desulfurization equipment 47 Chimney 50 Liquefied Ammonia Supply Source 52 Oil Fuel Source 54 Steam Source 60 Burnagan 61 Burner Gun (liquefied gas fuel burner gun) 62 Wind box front plate 62h Burner insertion hole 64 Oil fuel transport pipe (oil fuel supply route) 64a Proximal end 64b Tip 64s straight pipe section 64t curved section 65 Steam transport pipe (atomization gas supply route, atomization gas transport pipe) 65a Proximal end 65b Tip 65s straight pipe section 65t curved section 67 nozzle 69 Piping connection parts (connections) 69th floor, one side 69g other side 71 Flexible hose 72 Flexible hose 75 connection port 76 Connection port 77 Pipe insertion hole 78 Pipe insertion hole 80 External oil fuel piping 80a end 80v on-off valve 81 External steam piping 81a End 81v on-off valve 82 External ammonia piping 82v on-off valve 83 Connection fittings (connection parts) 83a Metal fitting connection port 83b Metal fitting connection port 85 Seal packing 87 Clamping member 87a One end 87b Other end 87c Fastening screw 89 Plug member 90 Food 92 Steam shutoff member (atomized gas shutoff member) 94 Ammonia transport pipe 94a Tip 94b Proximal end 95 Flexible Hose 96 Piping connection parts (connections) 97 Connecting piping 97a Flange 98 Closure member F oil fuel G Steam L Liquefied ammonia fuel

Claims

1. A burner that can switch between liquefied gas fuel and oil fuel, a burner gun having a nozzle for injecting liquefied gas fuel and / or oil fuel; an atomization gas supply path that supplies atomization gas to the nozzle for atomizing the oil fuel injected from the nozzle; The burner is provided with an atomization gas shutoff member capable of blocking the flow of the atomization gas flowing through the atomization gas supply path.

2. the atomization gas supply path comprises an atomization gas transport pipe, and a connection part to which a base end of the atomization gas transport pipe is connected and which connects the atomization gas transport pipe with an external gas pipe for supplying the atomization gas; 2. The burner according to claim 1, wherein said atomizing gas closing member is detachable from said connecting portion.

3. The burner gun is used by switching between liquefied gas fuel and oil fuel, an oil fuel supply path for supplying oil fuel to the nozzle; 2. The burner according to claim 1, wherein the atomizing gas shutoff member blocks the flow of the atomizing gas when the liquefied gas fuel is supplied to the oil fuel supply path.

4. The burner guns include an oil fuel burner gun that uses oil fuel and a liquefied gas fuel burner gun that uses liquefied gas fuel, a liquefied gas fuel supply path for supplying liquefied gas fuel to the nozzle of the liquefied gas fuel burner gun; an oil fuel supply path for supplying oil fuel to the nozzle of the oil fuel burner gun; Equipped with 2. The burner according to claim 1, further comprising an oil fuel shutoff member capable of blocking the flow of oil fuel to the oil fuel supply path.

5. a connecting portion for connecting an external oil fuel pipe for supplying oil fuel from the outside to the oil fuel supply path; 5. The burner according to claim 4, wherein the oil fuel shutoff member is detachable from the connecting portion.

6. 6. The burner of claim 5, wherein said oil fuel closure member is fixed relative to said liquefied gas fuel burner gun.

7. 7. A burner according to claim 6, wherein said oil fuel shut-off member is integral with said atomizing gas shut-off member.

8. A boiler equipped with the burner according to any one of claims 1 to 7.

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