Cleaning device

Abstract

To restrain damage to a cleaning device caused by heat.SOLUTION: A pushing rod 100 cleans a burner provided in a boiler, and comprising a burner nozzle for injecting fuel and oxidizing gas into a furnace, and is a long member extending in a predetermined direction. The pushing rod 100 comprises: a tip part 50 located at one end in the predetermined direction, and to be brought into contact with deposits adhering to the inside of the burner nozzle; and a base end part 80 located at the other end in the predetermined direction, and outside the burner. A cooling air flow passage through which cooling air flows is formed inside the tip part 50.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to cleaning devices. [Background technology]

[0002] Large boilers, such as power generation boilers, have a hollow furnace installed vertically, with multiple burners arranged circumferentially around the furnace wall. Large boilers also have a flue connected vertically above the furnace, with a heat exchanger for generating steam located in the flue. The burner 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] In such boilers, when a fuel containing ash (for example, coal) is burned in a burner, ash is generated by the combustion. The generated ash adheres to and accumulates on the surfaces of components inside the boiler and then solidifies. Since the solidified ash can cause various problems, it is known that the solidified ash must be removed (for example, see Patent Document 1).

[0004] Patent Document 1 describes a method in which ash contained in the fuel melts and turns into slag, which adheres and solidifies around the tip of the water-cooled nozzle, i.e., the outer periphery of the tip of the fuel nozzle. When slag has adhered and solidified, the method involves using an air cylinder to project the fuel nozzle into the furnace, causing it to collide with the slag, while continuing to supply fuel without stopping combustion, and then directly removing the slag with the fuel nozzle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-161284 Summary of the Invention [Problem to be solved by the invention]

[0006] In boilers, etc., ash generated during combustion can flow into the burner nozzle through the opening of the burner nozzle that sprays fuel and air into the furnace, and accumulate and stick to the inside of the nozzle.If ash accumulates and sticks inside the burner nozzle, it could clog the opening of the burner nozzle that sprays fuel and air.

[0007] To prevent the burner nozzle opening from clogging, it is conceivable to insert a rod-shaped cleaning device (hereinafter referred to as a "thrust rod") into the burner nozzle and remove the accumulated and solidified ash (hereinafter referred to as "clinker") from the inside of the burner nozzle by pressing it with the thrust rod. However, because the burner nozzle is located facing the furnace, the thrust rod inserted inside is exposed to the high-temperature atmosphere and radiant heat inside the furnace and is prone to becoming hot. For this reason, there is a possibility that the thrust rod will be damaged by the heat received from the furnace.

[0008] The present disclosure has been made in consideration of the above circumstances, and aims to provide a cleaning device that can suppress damage to the cleaning device due to heat received from a furnace. [Means for solving the problem]

[0009] In order to solve the above problems, the cleaning device of the present disclosure employs the following measures. A cleaning device according to one aspect of the present disclosure is an elongated cleaning device that is provided in a boiler and extends along a predetermined direction for cleaning a burner having a burner nozzle that injects fuel or oxidizing gas into a furnace, and that is equipped with a tip portion located at one end in the predetermined direction and that abuts against deposits that have adhered to the inside of the burner nozzle, and a base portion located at the other end in the predetermined direction and outside the burner, and a cooling gas flow path through which cooling gas flows is formed inside the tip portion. [Effects of the Invention]

[0010] According to the present disclosure, damage to the cleaning device due to heat received from the furnace can be suppressed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram illustrating a coal-fired boiler according to an embodiment of the present disclosure. FIG. [Figure 2] 1 is a longitudinal cross-sectional view illustrating a burner according to an embodiment of the present disclosure. FIG. [Figure 3] FIG. 1 is a front view illustrating a burner nozzle according to an embodiment of the present disclosure. [Figure 4] FIG. 1 is a side view of a poker according to an embodiment of the present disclosure. [Figure 5] FIG. 2 is a side view showing a main portion of a push rod according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is a side view showing a main portion of a push rod according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a side view showing a main portion of a push rod according to an embodiment of the present disclosure. [Figure 8] FIG. 2 is a side view showing a main portion of a push rod according to an embodiment of the present disclosure. [Figure 9] FIG. 1 is a front view of a poker according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present disclosure will be described below with reference to the drawings. Note that the present invention 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.

[0013] FIG. 1 is a schematic diagram showing the configuration of a boiler using solid fuel as the main fuel according to this embodiment.

[0014] The boiler 10 of this embodiment is a boiler that can generate superheated steam by burning pulverized fuel made by pulverizing solid fuel with a burner and exchanging the heat generated by this combustion with feedwater or steam. Biomass fuel, coal, etc. are used as solid fuel.

[0015] The boiler 10 has a furnace 11, a combustion device, 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 multiple 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.

[0016] The combustion device is installed in the lower region of the furnace 11. In this embodiment, the combustion device has a plurality of burners 21A, 21B, 21C, 21D, 21E, and 21F (hereinafter, may be collectively referred to as "burners 21") attached to the furnace wall 101. The burners 21 are arranged at equal intervals along the circumferential direction of the furnace 11 (for example, four burners installed at each corner of the rectangular furnace 11), and are arranged in multiple rows along the vertical direction. Note that, for convenience of illustration, only two burners of one set are shown in FIG. 1, and each set is denoted by the reference numerals 21A, 21B, 21C, 21D, 21E, and 21F. The shape of the furnace 11, the number of burner rows, the number of burners in one row, the arrangement of the burners, and the like are not limited to this embodiment.

[0017] Burners 21A, 21B, 21C, 21D, 21E, and 21F are connected to a plurality of mills (pulverizers) 31A, 31B, 31C, 31D, 31E, and 31F (hereinafter, sometimes collectively referred to as "mills 31") via a plurality of pulverized fuel supply pipes 22A, 22B, 22C, 22D, 22E, and 22F (hereinafter, sometimes collectively referred to as "pulverized fuel supply pipes 22"). Mill 31 is, for example, a vertical roller mill having a pulverizing table (not shown) supported therein so as to be rotatable, and a plurality of pulverizing rollers (not shown) supported above the pulverizing table so as to be rotatable in conjunction with the rotation of the pulverizing table. The solid fuel pulverized by the cooperation of the pulverizing rollers and the pulverizing 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.

[0018] 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 (details will be described later), 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.

[0019] 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 sometimes collectively referred to as "superheaters 102"), reheaters 103A and 103B (hereinafter sometimes collectively referred to as "reheaters 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 flowing inside each heat exchanger. Note that the arrangement and shape of each heat exchanger are not limited to those shown in FIG. 1.

[0020] 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.

[0021] 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. 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 that has been treated in the environmental equipment is discharged to the outside of the system as exhaust gas.

[0022] In the boiler 10, when the multiple mills 31 are driven, 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). However, the oxidizing gas may have a higher or lower oxygen content than air. By adjusting the ratio of the oxygen content to the amount of fuel supplied within an appropriate range, stable combustion in the furnace 11 is achieved.

[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 and pulverized fuel with 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] [Burner] Next, the burner 21 according to this embodiment will be described in detail with reference to FIGS. The burner 21 has a burner nozzle 27 that sprays pulverized solid fuel (pulverized fuel) and combustion air (oxidizing gas) into the furnace 11, and a main body 29 that has a fuel flow path 28 formed therein that supplies the pulverized fuel and combustion air (oxidizing gas, primary air) to the burner nozzle 27.

[0027] The fuel flow path 28 is a flow path that supplies pulverized fuel and combustion air to the furnace 11. The downstream end of the main body 29 is connected to the burner nozzle 27. The upstream end of the main body 29 is connected to the pulverized fuel supply pipe 22.

[0028] The burner nozzle 27 has an opening 27a that opens into the furnace 11. As shown in Figures 2 and 3, the upper edge of the opening 27a is defined by a ceiling portion 27b of the burner nozzle 27. The lateral edges of the opening 27a are defined by sidewall portions 27c of the burner nozzle 27. The lower edge of the opening 27a is defined by a bottom surface portion 27d of the burner nozzle 27.

[0029] A straightening vane 30 is also provided inside the burner nozzle 27. The straightening vane 30 straightens the flow of pulverized coal supplied together with the primary air, aligning the flow direction of the pulverized coal with the axial direction of the burner nozzle 27 (the pulverized coal flow direction). The straightening vane 30 is configured in a grid shape inside the burner nozzle 27 by two straightening vanes: an upper straightening vane 30a arranged above and a lower straightening vane 30b arranged below. The upper straightening vane 30a includes one horizontal straightening vane 33a and two vertical straightening vanes 34a. The lower straightening vane 30b includes one horizontal straightening vane 33b and two vertical straightening vanes 34b. While the example in which the straightening vane 30 is configured in a grid shape by two straightening vanes has been shown, the present invention is not limited thereto. As long as the flow of the pulverized coal can be regulated and the flow direction aligned with the axial direction of the burner nozzle 27, it is sufficient that at least one straightening vane is arranged in the horizontal or vertical direction parallel to the axial direction.

[0030] [Cleaning tools] Next, the push rod (cleaning device) 100 according to this embodiment will be described with reference to FIGS. As shown in FIG. 2, the thrust rod 100 according to this embodiment is used when cleaning the inside of the burner 21 (particularly the burner nozzle 27) provided in the boiler 10.

[0031] 4, the push rod 100 is an elongated member that extends in a predetermined direction. Hereinafter, the direction in which the push rod 100 extends will be referred to as the longitudinal direction. The thrust rod 100 is a hollow member. More specifically, the thrust rod 100 is a cylindrical member extending along a central axis L, and has a space (a cooling air flow path 90, described later) formed inside over the entire length.

[0032] The cue stick 100 is made up of multiple parts. The cue stick 100 can be separated into multiple parts along the longitudinal direction. In other words, the cue stick 100 has multiple parts connected so that they are aligned in a straight line along the longitudinal direction.

[0033] The ram 100 has a tip portion (first part) 50, a first intermediate portion (second part) 60, a second intermediate portion 70, and a base portion (third part) 80. The tip portion 50, the first intermediate portion 60, the second intermediate portion 70, and the base portion 80 are arranged in a straight line along the longitudinal direction. The overall length of the ram 100 may be adjusted by, for example, omitting the first intermediate portion 60 and / or the second intermediate portion 70, depending on the distance between the inlet pipe 22a and the burner nozzle 27 or clinker C, which will be described later. A cooling air flow path (cooling gas flow path) 90 is formed inside the thrust rod 100 from the tip to the base end. The thrust rod 100 also has a plurality of hanging parts 91 on its outer periphery that can be hung by string-like members.

[0034] As shown in Fig. 4, the tip portion 50 is located at one end in the longitudinal direction of the thrust rod 100. As shown in Fig. 5, the tip portion 50 has a contact portion 51 that comes into contact with the clinker C adhering inside the burner nozzle 27, a base portion 52 that is connected to the upstream end of the contact portion 51 in the cooling air flow, a connecting portion 53 that connects the contact portion 51 and the base portion 52, and an engaging portion 54 that is connected to the upstream end of the base portion 52 in the cooling air flow.

[0035] The contact portion 51 is a cylindrical member centered on the central axis L and extending linearly along the central axis L. The downstream end of the cooling air flow path 90 is formed inside the contact portion 51. The inner and outer diameters of the contact portion 51 may be smaller than those of the base portion 52, and the end face on the tip side may be inclined with respect to a horizontal or vertical plane. In either case, the contact area between the contact portion 51 and the clinker C is reduced and the surface pressure increases, so that the clinker C can be removed with a relatively weak force and cleaning workability is improved.

[0036] The base portion 52 is a cylindrical member centered on the central axis L and extending linearly along the central axis L. The downstream end of the base portion 52 in the cooling air flow is connected to the upstream end of the contact portion 51 via a connecting portion 53.

[0037] Connecting portion 53 is an annular member centered on central axis L. It is provided between contact portion 51 and base portion 52, and connects contact portion 51 and base portion 52. A hanging portion 91 (more specifically, a tip hanging portion 91a, which will be described later) is provided on the outer circumferential surface of connecting portion 53.

[0038] The engaging portion 54 is a cylindrical member centered on the central axis L and extends linearly along the central axis L. An insertion portion 61 of the first intermediate portion 60 (described later) is inserted into the engaging portion 54, and the engaging portion 54 engages with the insertion portion 61. The inner diameter of the engaging portion 54 is formed slightly larger than the outer diameter of the insertion portion 61. Note that the inner peripheral surface of the engaging portion 54 and the outer peripheral surface of the insertion portion 61 may be threaded to screw the engaging portion 54 and the insertion portion 61 together. A hanging portion 91 is provided on the outer peripheral surface of the engaging portion 54.

[0039] The first intermediate section 60 and the second intermediate section 70 have the same structure, and therefore the following description will mainly focus on the first intermediate section 60, and will omit a detailed description of the second intermediate section 70. The first intermediate section 60 and the second intermediate section 70 may have the same or different longitudinal lengths.

[0040] As shown in Fig. 4, the first intermediate section 60 is located between the tip end 50 and the base end 80 in the longitudinal direction of the thrust rod 100. As shown in Fig. 6, the first intermediate section 60 has an insertion section 61 that is inserted into the engagement section 54, a base section 62 that is connected to the end of the insertion section 61 on the upstream side of the cooling air flow, and an engagement section 64 that is connected to the end of the base section 62 on the upstream side of the cooling air flow.

[0041] The insertion portion 61 is a cylindrical member centered on the central axis L and extends linearly along the central axis L. The insertion portion 61 integrally includes a fitting portion 61a that is inserted into and fits with the engaging portion 54 of the tip portion 50, and a flange portion 61b that is connected to the upstream end of the fitting portion 61a in the cooling air flow. The inner diameter of the fitting portion 61a and the inner diameter of the flange portion 61b may be the same size, or may be different sizes as long as the fitting relationship is not affected. The outer diameter of the fitting portion 61a is smaller than the outer diameter of the flange portion 61b.

[0042] The base 62 is a cylindrical member centered on the central axis L and extends linearly along the central axis L. The downstream end of the base 62 in the cooling air flow is connected to the upstream end of the insertion part 61 in the cooling air flow.

[0043] The engagement portion 64 is a cylindrical member centered on the central axis L and extends linearly along the central axis L. The insertion portion of the second intermediate portion 70 is inserted into and engages with the interior of the engagement portion 64. The insertion portion 81 of the base end portion 80, which will be described later, is inserted into and engages with the interior of the engagement portion of the second intermediate portion 70. The inner diameter of the engagement portion 64 is slightly larger than the outer diameter of the insertion portion 81. The inner peripheral surface of the engagement portion 64 and the outer peripheral surface of the insertion portion 81 may be threaded to thread the engagement portion 64 and the insertion portion 81 together. A hanging portion 91 is provided on the outer peripheral surface of the engagement portion 64.

[0044] As shown in Fig. 4, the base end 80 is located at the other longitudinal end of the thrust rod 100. As shown in Fig. 7, the base end 80 has an insertion portion 81 that is inserted into the engagement portion of the second intermediate portion 70, a base portion 82 that is connected to the end of the insertion portion 81 on the upstream side of the cooling air flow, and an engagement portion 84 that is connected to the end of the base portion 82 on the upstream side of the cooling air flow.

[0045] The insertion portion 81 is a cylindrical member centered on the central axis L and extends linearly along the central axis L. The insertion portion 81 integrally includes a fitting portion 81a that is inserted into and fits into an engaging portion of the second intermediate portion 70, and a flange portion 81b that is connected to the upstream end of the fitting portion 81a. The inner diameter of the fitting portion 81a and the inner diameter of the flange portion 81b are the same. The outer diameter of the fitting portion 81a is smaller than the outer diameter of the flange portion 81b.

[0046] The base 82 is a cylindrical member centered on the central axis L and extends linearly along the central axis L. The downstream end of the base 82 in the cooling air flow is connected to the upstream end of the insertion part 81 in the cooling air flow.

[0047] The engaging portion 84 is a cylindrical member centered on the central axis L and extends linearly along the central axis L. A supply portion 95 (see FIG. 8) of a cooling air supply device (not shown) is inserted into and engages with the inside of the engaging portion 84. The inner diameter of the engaging portion 84 is formed slightly larger than the outer diameter of the supply portion 95 of the cooling air supply device, which will be described later. Note that the inner peripheral surface of the engaging portion 84 and the outer peripheral surface of the supply portion 95 may be threaded to thread the engaging portion 84 and the supply portion 95 together.

[0048] In this embodiment, the engaging portion 54 of the tip portion 50, the engaging portion 64 of the first intermediate portion 60, and the engaging portion of the second intermediate portion 70 have the same inner diameter and longitudinal length. The engaging portion 84 of the base end portion 80 may also have the same inner diameter and longitudinal length as the engaging portion 54 of the tip portion 50, the engaging portion 64 of the first intermediate portion 60, and the engaging portion of the second intermediate portion 70. The inserting portion 61 of the first intermediate portion 60, the inserting portion of the second intermediate portion 70, and the inserting portion 81 of the base end portion 80 have the same outer diameter and longitudinal length. The supply portion 95 of the cooling air supply device may also have the same outer diameter and longitudinal length as the inserting portion 61 of the first intermediate portion 60, the inserting portion of the second intermediate portion 70, and the inserting portion 81 of the base end portion 80.

[0049] That is, in this embodiment, the first connecting portion, which is the connecting portion between the distal end portion 50 and the first intermediate portion 60, and the second connecting portion, which is the connecting portion between the second intermediate portion 70 and the proximal end portion 80, have the same structure. Furthermore, in this embodiment, the connecting portion between the first intermediate portion 60 and the second intermediate portion 70 also has the same structure as the first connecting portion and the second connecting portion. Therefore, for example, it is also possible to engage the insertion portion 81 of the proximal end portion 80 with the engaging portion 64 of the first intermediate portion 60.

[0050] The cooling air flow path 90 is a linear flow path extending along the central axis L. Cooling air supplied from a supply unit 95 of a cooling air supply device flows through the cooling air flow path 90. The cooling air supplied from the supply unit 95 of the cooling air supply device flows from the upstream end of the cooling air flow formed in the base end 80 to the downstream end of the cooling air flow formed inside the tip end 50, and then is discharged into the furnace 11. In detail, the cooling air supplied from the supply unit 95 of the cooling air supply device flows from the inside of the engagement portion 84 of the base end 80 to the inside of the contact portion 51 of the tip end 50, and then is discharged into the furnace 11.

[0051] As shown in Fig. 9, the hanging part 91 is an arc-shaped member, both ends of which are fixed to the upper end of the outer circumferential surface of the thrust rod 100. As shown in Fig. 8, the hanging part 91 can be suspended by a string-like member (in this embodiment, a wire rope 92, which will be described later). The multiple hanging parts 91 are arranged in a line at predetermined intervals along the longitudinal direction, as shown in Fig. 4. The hanging part 91 provided closest to the tip (hereinafter referred to as "tip hanging part 91a") is provided at the connection part between the protruding part of tip part 50 and the base part.

[0052] As shown in Figure 8, wire ropes 92, which are string-like members, are engaged with hanging portions 91. Specifically, one wire rope 92 is engaged with all hanging portions 91. Specifically, wire rope 92 is passed through all hanging portions 91. Wire rope 92 is provided with a stopper 92a so that its tip is loop-shaped. The outer diameter of stopper 92a is larger than the inner diameter of tip hanging portion 91a. Therefore, stopper 92a prevents wire rope 92 from slipping out of tip hanging portion 91a.

[0053] 8, the other end of the wire rope 92 is fastened to a fall prevention rod 93 extending in the vertical direction. The fall prevention rod 93 may be fixed to the base end portion 80.

[0054] [Cleaning method] Next, a method for cleaning the burner 21 using the thrust rod 100 according to this embodiment will be described. When the burner 21 burns a fuel containing ash (for example, coal or biomass fuel), ash is generated by the combustion. In particular, when the burner 21 burns pulverized coal as pulverized fuel, a large amount of ash is generated because the ash content is higher than that of other fuels. The generated ash accumulates and adheres to components inside the boiler 10, and then solidifies. Furthermore, when the ash contains elements such as Na, Ca, and K, the melting point of the ash generated by combustion decreases, so some of the ash melts due to the heat of the furnace and tends to adhere to the components that make up the boiler 10. 2 and 3, ash also accumulates and solidifies on the bottom surface 27d of the burner nozzle 27 of the burner 21. Hereinafter, the accumulated and solidified ash will be referred to as "clinker C."

[0055] First, the burner 21 is visually inspected through a peephole provided in the furnace wall 101 of the boiler or the like to check the state of accumulation of clinker C on the bottom surface 27d of the burner nozzle 27. If it is determined that clinker C has accumulated to an extent that it needs to be removed, cleaning is performed using the thrust rod 100. Note that cleaning using the thrust rod 100 is performed when the burner 21 is not ignited. In other words, it is performed while the burner 21 is stopped.

[0056] As shown in FIG. 2 , when cleaning the burner nozzle 27 of the burner 21, first, the inlet pipe 22a of the pulverized fuel supply pipe 22 is opened from its closed state. Next, a ramming rod 100 is inserted into the pulverized fuel supply pipe 22 and the burner nozzle 27 through the inlet pipe 22a. Next, the tip 50 of the ramming rod 100 is used to ram the clinker C that has accumulated and solidified inside the burner nozzle 27 toward the furnace 11. When the clinker C is rammed with the tip 50 of the ramming rod 100, the adhesive portion between the clinker C and the burner nozzle 27 is peeled off, and the clinker C is pushed out of the burner nozzle 27 into the furnace 11. This removes the clinker C from the burner nozzle 27. Note that the operation of ramming the clinker C with the tip 50 of the ramming rod 100 is repeated until the clinker C is removed from the burner nozzle 27. At this time, the worker holds the base end 80 located outside the burner 21.

[0057] In this embodiment, the distance from the inlet pipe 22a to the burner nozzle 27 varies depending on the position of the burner 21. Specifically, for example, the distance from the inlet pipe 22a to the burner nozzle 27 differs between the burner 21A (see FIG. 1) and the burner 21F (see FIG. 1). Therefore, before inserting the thruster rod 100 into the burner 21, the longitudinal length of the thruster rod 100 is adjusted so that it corresponds to the distance from the inlet pipe 22a to the burner nozzle 27 of the burner 21 to be inserted. Specifically, the longitudinal length of the thruster rod 100 is adjusted by adjusting the number and type (length) of intermediate sections (first intermediate section 60 and second intermediate section 70). Note that if the required longitudinal length of the thruster rod 100 can be obtained by the tip end 50 and the base end 80, the intermediate sections (first intermediate section 60 and second intermediate section 70) may not be used.

[0058] After adjusting the length of the thrust rod 100, the wire rope 92 is passed through the hanging parts 91 in order, starting from the one located at the tip. Once the wire rope 92 has been passed through all of the hanging parts 91, the other end of the wire rope 92 is fastened to the fall prevention rod 93. In this way, the wire rope 92 is attached to the thrust rod 100. With the wire rope 92 attached, the thrust rod 100 is inserted into the burner 21, and the inside of the burner 21 is cleaned.

[0059] According to this embodiment, the following advantageous effects are achieved. In this embodiment, the burner 21 is provided with a tip 50 that comes into contact with the clinker C adhering to the inside of the burner nozzle 27. This allows the clinker C inside the burner nozzle 27 to be pressed with the tip of the thrust rod 100, thereby making it possible to remove the clinker C from the inside of the burner. Furthermore, in this embodiment, a cooling air flow path 90 through which cooling air flows is formed inside the thruster 100. As a result, the thruster 100 (particularly the tip 50), which is prone to becoming hot due to the heat of the furnace 11, is cooled by the cooling air flowing through the cooling air flow path 90. This prevents the thruster 100 from becoming hot, thereby preventing damage to the thruster 100 due to heat. Furthermore, by circulating cooling air from the base end 80 to the tip end 50, the base end 80 that is held by the worker during cleaning work can be kept at a relatively low temperature, thereby reducing the risk of injury to the worker, such as burns due to heat, and ultimately improving the safety of cleaning work.

[0060] Furthermore, in this embodiment, during cleaning, the thrust rod 100 is supported in a cantilevered manner with the base end portion 80 as a fixed point, which makes it easy for the tip portion 50 to fall off. On the other hand, in this embodiment, the tip portion 50 is provided with a hanging part 91 that is provided on the outer peripheral surface thereof and can be hung by a string-like member. This allows the tip portion 50 to be hung by a string-like member. Therefore, the tip portion 50 is less likely to fall.

[0061] In this embodiment, the pusher rod 100 can be separated into multiple parts along the longitudinal direction. That is, the pusher rod 100 is constructed by connecting multiple parts so that they are lined up along the longitudinal direction. This makes it possible to change the longitudinal length of the pusher rod 100 by changing the number of connected parts. Therefore, the length of the pusher rod 100 can be changed to a length that makes cleaning easier, improving the workability of the cleaning work.

[0062] In this embodiment, the first connecting portion connecting the tip portion 50 and the first intermediate portion 60 and the second connecting portion connecting the second intermediate portion 70 and the base end portion 80 have the same structure. This makes it possible to connect, for example, the tip portion 50 and the base end portion 80. This makes it easy to change the number of parts to be connected. This also makes it easy to change the longitudinal length of the thrust rod 100. This makes it possible to change the length of the thrust rod 100 to a length that makes cleaning easier, further improving the workability of cleaning work.

[0063] The present disclosure is not limited to the inventions according to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. In the above-described embodiment, the boiler of the present invention has been described as a boiler that uses solid fuel as fuel, such as coal, biomass fuel, petroleum coke (PC), petroleum residue, etc. The boiler can be fueled not only with solid fuels, but also with petroleum products such as heavy oil, light oil, and crude oil, industrial wastewater, liquefied ammonia, and other liquid fuels. It can also use gaseous fuels such as natural gas, various petroleum gases, by-product gases generated in steelmaking processes, hydrogen gas, and ammonia gas. Furthermore, the present invention can also be applied to a multi-fuel boiler that uses a combination of these various fuels.

[0064] Furthermore, in the above configuration, an example in which two intermediate portions are provided has been described, but the present disclosure is not limited to this. There may be only one intermediate portion, or three or more intermediate portions.

[0065] The cleaning device according to the above-described embodiment can be understood, for example, as follows. The cleaning device according to the first aspect of the present disclosure is an elongated cleaning device (100) that is provided in a boiler (10) and extends along a predetermined direction for cleaning a burner (21) having a burner nozzle (27) that injects fuel or oxidizing gas into a furnace (11), and includes a tip end (50) that is located at one end in the predetermined direction and abuts against deposits (C) that have adhered to the inside of the burner nozzle (27), and a base end (80) that is located at the other end in the predetermined direction and outside the burner, and a cooling gas flow path (90) through which a cooling gas flows is formed inside the tip end (50).

[0066] The above-described configuration includes a tip that comes into contact with deposits adhering to the inside of the burner nozzle, thereby enabling the deposits to be removed from the inside of the burner by, for example, pressing the deposits inside the burner nozzle with the tip of the cleaning device.

[0067] In addition, in the above configuration, a cooling gas flow path through which cooling gas flows is formed inside the tip portion. As a result, the tip portion of the cleaning device, which is likely to become hot due to the heat of the furnace, is cooled by the cooling gas flowing through the cooling gas flow path. Therefore, the temperature rise of the cleaning device can be suppressed, and damage to the cleaning device due to heat can be suppressed.

[0068] Furthermore, the cleaning device according to a second aspect of the present disclosure is the cleaning device of the first aspect, further comprising a hanging part (91) that is provided on the outer circumferential surface of the tip end and that can be hung by a string-like member.

[0069] In the above configuration, the tip portion is provided with a hanging portion that is provided on the outer peripheral surface of the tip portion and can be hung with a string-like member. This allows the tip portion to be hung with the string-like member, making it less likely for the tip portion to fall.

[0070] Furthermore, the cleaning device according to a third aspect of the present disclosure is the cleaning device of the first or second aspect described above, which is separable into a plurality of parts (50, 60, 70, 80) along the predetermined direction.

[0071] In the above configuration, the cleaning device can be separated into multiple parts along a predetermined direction. That is, the cleaning device is configured by connecting multiple parts so that they are lined up along the predetermined direction. This allows the length of the cleaning device in the predetermined direction to be changed by changing the number of connected parts. Therefore, the length of the cleaning device can be changed to a length that makes cleaning easier, thereby improving the workability of cleaning work.

[0072] In addition, in the cleaning device according to the fourth aspect of the present disclosure, in the third aspect described above, the multiple parts include a first part (50) having the tip end portion, a second part (60) connected to the first part (50), a third part (70) connected to the second part (60), and a fourth part (80) having the base end portion and connected to the third part, and the first connecting portion connecting the first part and the second part and the second connecting portion connecting the third part and the fourth part have the same structure.

[0073] In the above configuration, the first connecting portion connecting the first part and the second part and the second connecting portion connecting the third part and the fourth part have the same structure. This allows the first part to be connected to the third part or the fourth part. This makes it easy to change the number of parts to be connected. This makes it easy to change the length of the cleaning device in a predetermined direction. This allows the length of the cleaning device to be changed to a length that makes cleaning easier, further improving the workability of cleaning work. [Explanation of symbols]

[0074] 10: Boiler 11: Furnace 12: Combustion gas passage 13: Flue 21: Burner 22:Powdered fuel supply pipe 22a: Inlet pipe 23: Wind box 24: Wind road 25: Additional air port 26: Additional air duct 27: Burner nozzle 27a: Opening 27b: Ceiling part 27c: Side wall part 27d: Bottom part 28: Fuel flow path 29: Main body 30: Rectifier plate 31: Mill 32: Forced ventilation fan 33a: Horizontal rectifier plate 33b: Horizontal rectifier plate 34a: Vertical rectifier plate 34b: Vertical rectifier plate 41: Gas duct 42: Air preheater 43: Denitration equipment 44: Equipment 46: Desulfurization equipment 47: Chimney 50:Tip 51: Contact part 52: Base 53:Connection part 54: Engagement part 60: First intermediate section 61: Insertion section 61a: fitting part 61b: flange part 62: Base 64: Engagement part 70: Second intermediate section 80: Proximal end 81: Insertion section 81a: Fitting part 81b: Flange part 82: Base 84: Engagement part 90: Cooling air flow path 91: Hanging part 91a: Tip hanging part 92: Wire rope 92a: Stopper 93: Fall prevention rod 95: Supply section 100: Goad 101: Furnace wall 102:Superheater 103 :Reheater 104: Economizer

Claims

1. A long cleaning device extending in a predetermined direction for cleaning a burner provided in a boiler and having a burner nozzle for injecting fuel or oxidizing gas into a furnace, a tip portion located at one end in the predetermined direction and coming into contact with deposits adhering to the inside of the burner nozzle; a base end portion located outside the burner at the other end in the predetermined direction, The cleaning device has a cooling gas flow path formed inside the tip portion, through which a cooling gas flows.

2. The cleaning device according to claim 1 , further comprising a hanging portion provided on the outer peripheral surface of the tip portion and capable of being hung by a string-like member.

3. 3. The cleaning device according to claim 1, wherein the cleaning device is separable into a plurality of parts along the predetermined direction.

4. the plurality of parts include a first part having the tip end portion, a second part connected to the first part, a third part connected to the second part, and a fourth part having the base end portion and connected to the third part, The cleaning device according to claim 3 , wherein a first connecting portion connecting the first part and the second part and a second connecting portion connecting the third part and the fourth part have the same structure.

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