JP7516199B2 - Burner repair method, burner, boiler and power plant - Google Patents

Description

This disclosure relates to a burner repair method, a burner, a boiler, and a power generation plant.

Large boilers used in power plants have a hollow furnace that is installed vertically, and multiple burners are arranged on the furnace wall along the circumferential direction of the furnace. The boiler also has a flue connected vertically above the furnace, and a heat exchanger for generating steam is arranged in this flue. The burner then injects a mixture of fuel and air (oxidizing gas) into the furnace to form a flame, generating combustion gas that flows into the flue. A heat exchanger is installed in the area where the combustion gas flows, and superheated steam is generated by heating the water and steam flowing inside the heat transfer tubes that make up the heat exchanger.

For example, as disclosed in Patent Document 1, some burners used in coal-fired boilers have a burner body and a burner nozzle, and the burner nozzle is connected to the burner body so that the angle can be adjusted. In such burners, a combustible mixture of fuel (e.g., pulverized coal) and primary air flows inside the burner body, and high-temperature secondary air flows outside the burner body. In this case, if damage occurs to the tip of the burner body (the burner body near the connection with the burner nozzle), depending on the pressure difference between the inside and outside of the burner body and the angle of the burner nozzle, the combustible mixture may leak from the damaged area to the outside of the burner body.

JP 2001-165411 A

As mentioned above, high-temperature secondary air flows outside the burner body, so if the combustible mixture leaks outside the burner body, there is a possibility that the combustible mixture will undergo a high-temperature oxidation reaction outside the burner body. For this reason, it is necessary to repair the damaged area in order to prevent the combustible mixture from leaking.

For burners that do not have a burner nozzle angle adjustment function, or if the burner nozzle angle adjustment function is not used after repairing a damaged area, it is possible to repair the damaged area by attaching a repair part to the burner body from the outside of the burner body with fasteners such as bolts. This is because the position and angle of the burner nozzle are constant, so even if the external shape of the burner body changes due to the repair part, it will not interfere with the burner nozzle.

On the other hand, when using the angle adjustment function of the burner nozzle, minor damage can be repaired from the inside of the burner body with a filler such as ceramic putty. Also, when damage occurs that cannot be repaired with a filler, for example, when the damaged area is large, there is a method of attaching a repair part to the burner body by welding.
However, depending on the material of the burner body, welding may not be possible to the burner body. In such cases, extensive repair work such as replacing the burner body is required, which creates problems in terms of cost and delivery time.

This disclosure has been made in consideration of these circumstances, and aims to provide a burner repair method, a burner, a boiler, and a power generation plant that can quickly and easily repair damaged areas even if damage occurs to the burner body.

In order to solve the above problems, the burner repair method, burner, boiler, and power plant disclosed herein employ the following measures.
That is, a method of repairing a burner according to one aspect of the present disclosure is a method of repairing a burner having a cylindrical burner body through which a mixed gas containing fuel flows, and includes a removal process of removing a specified portion including a damaged area generated in the wall portion of the burner body from the wall portion of the burner body, a production process of providing a repair material having a shape corresponding to the defective portion formed in the wall portion by the specified portion on a plate material shaped along the inner surface of the wall portion, and a connection process of connecting the plate material to the inner surface of the wall portion with the repair material positioned in the defective portion.

The burner according to one aspect of the present disclosure includes a burner body that is cylindrical and surrounded by a wall portion, with a predetermined portion of the wall portion removed, a plate material that is connected to the inner peripheral surface of the wall portion so as to fit along the inner peripheral surface of the wall portion, and a repair material that is shaped to correspond to a defect portion formed in the wall portion by the predetermined portion and is attached to the plate material while being positioned in the defect portion.

In addition, a boiler according to one aspect of the present disclosure is equipped with the burner described above.

A power generation plant according to one aspect of the present disclosure includes the above-mentioned boiler and a power generation unit that generates power using steam generated by the boiler.

According to the present disclosure, it is possible to provide a burner repair method, a burner, a boiler, and a power generation plant that can quickly and easily repair damaged areas even if the burner body is damaged.

1 is a schematic configuration diagram of a coal-fired boiler according to a first embodiment. FIG. 2 is a partial enlarged view (longitudinal cross-sectional view) of the vicinity of the open end of the burner according to the first embodiment. 3 is a cross-sectional view taken along line III-III shown in FIG. 2. FIG. 2 is a front view of the burner according to the first embodiment, seen from the open end side. FIG. 2 is a partial perspective view of a burner body in which a damaged portion occurs in the first embodiment. FIG. 2 is a partial perspective view of the burner body in which a predetermined portion is determined in the first embodiment. FIG. 2 is a partial perspective view of a burner body in which a missing portion is formed in the first embodiment. FIG. 2 is a perspective view of a repair material according to the first embodiment. FIG. 2 is a perspective view of a plate material according to the first embodiment. FIG. 2 is a partial perspective view of a burner body on which a repair material and a plate material are arranged in the first embodiment. FIG. 2 is a perspective view of a repair material and a plate material in the first embodiment. FIG. 2 is a partial perspective view of a burner body in which a plate material to which a repair material is connected is arranged in the first embodiment. FIG. 2 is a partial perspective view of a burner body in which a plate material to which a connecting plate material is connected is arranged in the first embodiment. FIG. 2 is a partial perspective view of the burner body in which a gap between the repair material and the wall portion is filled with a filler material in the first embodiment. FIG. 2 is a vertical cross-sectional view of a burner body in which a step between a plate material and a wall portion is filled with a filler material in the first embodiment. FIG. 4 is a vertical cross-sectional view of the burner when a plate material is connected in FIG. 3 . 17 is a partial enlarged view of a portion X shown in FIG. 16 when the burner nozzle according to the first embodiment is offset. FIG. 17 is a partial enlarged view of part Y shown in FIG. 16 when the burner nozzle according to the first embodiment is offset. FIG. FIG. 11 is a partial perspective view of a burner body in which a damaged portion occurs in the second embodiment. FIG. 11 is a partial perspective view of a burner body in which a plate material is arranged in a second embodiment.

[About the boiler]
First, the configuration of the boiler will be described.
FIG. 1 is a schematic diagram showing the configuration of a boiler according to the present embodiment.
The boiler 10 is a coal-fired (pulverized coal-fired) boiler that uses, for example, pulverized coal made by pulverizing coal (carbon-containing solid fuel) as pulverized fuel, burns this pulverized fuel using a burner, and exchanges the heat generated by this combustion with feed water or steam to generate superheated steam.

The boiler 10 is provided in a power generation plant equipped with a power generation unit. The power generation unit includes, for example, a steam turbine and a generator that is rotationally driven by the steam turbine. The steam generated by the boiler 10 is supplied to the steam turbine provided in the power generation plant to rotate the steam turbine. The steam turbine then rotates the generator to generate electricity.

As shown in FIG. 1, the boiler 10 has a furnace 11, a combustion device 12, and a combustion gas passage 13. The furnace 11 has a hollow rectangular cylinder shape and is installed vertically. The furnace wall 101 that constitutes the furnace 11 is composed of multiple heat transfer tubes and fins that connect them, and exchanges heat generated by the combustion of pulverized fuel with water and steam flowing inside the heat transfer tubes, suppressing the temperature rise of the furnace wall 101.

The combustion device 12 is provided on the lower side of the furnace wall 101 that constitutes the furnace 11. In this embodiment, the combustion device 12 has multiple burners (e.g., 21, 22, 23, 24, 25) attached to the furnace wall 101. The burners 21, 22, 23, 24, 25 are arranged at equal intervals along the circumferential direction of the furnace 11 as one set, and are arranged in multiple stages (e.g., five stages in FIG. 1) along the vertical direction. However, the shape of the furnace 11 and the number, number of stages, arrangement, etc. of burners in one stage are not limited to this embodiment.

The burners 21, 22, 23, 24, and 25 are connected to a plurality of pulverizers (mills) 31, 32, 33, 34, and 35 via pulverized coal supply pipes 26, 27, 28, 29, and 30. The pulverizers 31, 32, 33, 34, and 35 are configured, for example, such that a pulverizer table (not shown) is supported in the housing of the pulverizer so as to be rotatable and driven, and a plurality of pulverizer rollers (not shown) are supported above the pulverizer table so as to be rotatable in conjunction with the rotation of the pulverizer table. When coal is fed between the plurality of pulverizer rollers and the pulverizer table, it is pulverized and transported by a carrier gas (primary air, oxidizing gas) to a classifier (not shown) in the housing of the pulverizer, and the pulverized fuel classified to a predetermined particle size range can be supplied to the burners 21, 22, 23, 24, and 25 from the pulverized coal supply pipes 26, 27, 28, 29, and 30.

Furnace 11 is also provided with a wind box 36 at the mounting positions of burners 21, 22, 23, 24, and 25, and one end of an air duct (airway) 37 is connected to this wind box 36. The other end of air duct 37 is provided with a forced draft fan (FDF: Forced Draft Fan) 38.

As shown in FIG. 1, the combustion gas passage 13 is connected to the vertical upper part of the furnace 11. The combustion gas passage 13 is provided with superheaters 102, 103, 104, reheaters 105, 106, and a coal economizer 107 as heat exchangers for recovering the heat of the combustion gas, and heat is exchanged between the combustion gas generated in the furnace 11 and the feed water and steam flowing inside each heat exchanger.

As shown in FIG. 1, the combustion gas passage 13 is connected to a flue 14 downstream, through which the combustion gas that has undergone heat exchange is discharged. An air heater (air preheater) 42 is provided between the flue 14 and the air duct 37, and heat is exchanged between the air flowing through the air duct 37 and the combustion gas flowing through the flue 14, thereby raising the temperature of the combustion air supplied to the burners 21, 22, 23, 24, and 25.

The flue 14 is provided with a denitration device 43 at a position upstream of the air heater 42. The denitration device 43 supplies a reducing agent, such as ammonia or urea water, that has the effect of reducing nitrogen oxides into the flue 14, and promotes the reaction between the nitrogen oxides in the combustion gas to which the reducing agent has been supplied and the reducing agent by the catalytic action of a denitration catalyst installed in the denitration device 43, thereby removing and reducing the nitrogen oxides in the combustion gas. The gas duct 41 connected to the flue 14 is provided with a dust collector 44, such as an electric dust collector, an induced draft fan (IDF) 45, a desulfurization device 46, etc. at a position downstream of the air heater 42, and a chimney 50 is provided at the downstream end.

On the other hand, when the multiple pulverizers 31, 32, 33, 34, 35 are driven, the generated pulverized fuel is supplied to the burners 21, 22, 23, 24, 25 together with the carrier gas (primary air, oxidizing gas) through the pulverized coal supply pipes 26, 27, 28, 29, 30. In addition, the exhaust gas discharged from the flue 14 is heat exchanged with the air heater 42, and the heated combustion air (secondary air, oxidizing gas) is supplied to the burners 21, 22, 23, 24, 25 from the air duct 37 through the wind box 36. The burners 21, 22, 23, 24, 25 blow a pulverized fuel mixture (mixed gas) of the pulverized fuel and the carrier gas into the furnace 11 and also blow the combustion air into the furnace 11, at which time the pulverized fuel mixture is ignited to form a flame. A flame is generated in the lower part of the furnace 11, and high-temperature combustion gas rises inside the furnace 11 and is discharged into the combustion gas passage 13. In this embodiment, air is used as the oxidizing gas. Gases with a higher or lower oxygen content than air may also be used, and can be used by optimizing the fuel flow rate.

Then, as shown in FIG. 1, the combustion gas undergoes heat exchange in the second superheater 103, the third superheater 104, the first superheater 102 (hereinafter sometimes simply referred to as "superheater"), the second reheater 106, the first reheater 105 (hereinafter sometimes simply referred to as "reheater"), and the economizer 107, which are arranged in the combustion gas passage 13. After that, nitrogen oxides are reduced and removed by the denitrification device 43, particulate matter is removed by the dust collector 44, and sulfur oxides are removed by the desulfurization device 46, and the combustion gas is discharged into the atmosphere from the chimney 50. Note that the heat exchangers do not necessarily have to be arranged in the order described above with respect to the combustion gas flow.

[Burner structure]
Next, a description will be given of the structure of the burners 21, 22, 23, 24, and 25. Note that the structure described below is common to the burners 21, 22, 23, 24, and 25. Therefore, in the following description, of the burners 21, 22, 23, 24, and 25, the burner 21 will be described as an example.

As shown in Figures 2 and 3, the burner 21 includes a burner body 210 and a burner nozzle 220 provided at the open end side of the burner body 210. Note that the left side of the burner 21 shown in Figures 2 and 3 is the interior of the furnace 11 (inside the furnace).

2 to 4, the burner body 210 is configured in a cylindrical shape closed by a body wall portion 211. In particular, the open end side corresponding to the tip of the burner body 210 is configured in a square cylindrical shape composed of four body walls 211A, 211B, 211C, and 211D. The burner body 210 is made of, for example, cast iron (FC200, etc.).
In the following description, when the positions of the main body walls are to be distinguished from one another, the reference numerals 211A, 211B, 211C, and 211D will be used. When the main body walls are to be collectively referred to, the reference numeral 211 will be used.

The inside of the main body wall 211 is the main body side primary flow path MP1. The supplied mixed gas flows through this main body side primary flow path MP1 toward the burner nozzle 220 side (furnace 11 side).

The outside of the main body wall 211 is the main body side secondary flow path MP2. This main body side secondary flow path MP2 is located inside the wind box 36, and the combustion air supplied from the air duct 37 flows toward the burner nozzle 220 side (furnace 11 side).

The burner nozzle 220 is configured in a double cylindrical shape in which a rectangular cylindrical portion closed by a nozzle inner wall 222 is housed inside a cylindrical portion closed by a nozzle outer wall 221 .
The burner nozzle 220 is provided on the open end side (furnace 11 side) of the burner body 210 and surrounds the outer circumferential surface of the open end side of the burner body 210.

As shown in FIG. 3, at the position where the nozzle outer wall 221 and nozzle inner wall 222 of the burner nozzle 220 overlap with the body wall 211 (more specifically, body wall 211B, 211D) of the burner body 210, a pin member 230 is inserted from the outside of the opposing wall surface (the upper and lower wall surfaces shown in FIG. 3) of the burner nozzle 220. The burner nozzle 220 is connected to the burner body 210 by the inserted pin member 230, and is configured to be rotatable relative to the burner body 210 with the pin member 230 as a rotation fulcrum.

As shown in Figures 2 to 4, the inside of the nozzle inner wall 222 is the nozzle-side primary flow passage NP1. In this nozzle-side primary flow passage NP1, the mixed gas supplied from the main body-side primary flow passage MP1 of the burner main body 210 flows toward the furnace 11.

The nozzle side secondary flow passage NP2 is defined between the nozzle outer wall 221 and the nozzle inner wall 222. Combustion air supplied from the main body side secondary flow passage MP2 of the burner main body 210 flows through this nozzle side secondary flow passage NP2 toward the furnace 11.

[How to repair the burner]
When the burner 21 configured as above is used, as shown in Fig. 5, a damaged area 223 may occur on the inner wall of the body wall 211 (e.g., the body wall 211A) located on the open end side of the burner body 210. The damaged area 223 occurs due to, for example, thinning due to wear, cracks, burnout, etc.

If it is desired to continue using the burner 21 with the damaged area 223 as described above, the damaged area 223 must be repaired. Below, a method for repairing the damaged area 223 in the main body wall 211 will be described. Note that it is assumed that the burner nozzle 220 is removed from the burner main body 210 when repair work begins.

[First embodiment]
The first embodiment of the present disclosure will be described below.
As shown in Fig. 6, a range of a predetermined portion 224 is determined in the body wall portion 211A, which includes a damaged portion 223 caused by the use of the burner 21. After the predetermined portion 224 is determined, the predetermined portion 224 is cut and removed from the body wall portion 211A (removal step), as shown in Fig. 7. As a result, a missing portion 225 is formed in the body wall portion 211A.

8, a separate member (repair material 240) is prepared that corresponds to the shape of the missing portion 225. The repair material 240 has substantially the same shape as the missing portion 225. Taking into consideration the conditions of use of the burner body 210, the repair material 240 is made of, for example, stainless steel.
9, a plate material 250 (plate material 250A) is prepared that is shaped to fit the inner circumferential surface of the body wall 211. In the case of FIG. 9, the shape of the plate material 250A is a flat plate that fits the inner circumferential surface of the body wall 211A. If the inner circumferential surface of the body wall 211A is curved, the plate material 250A is also curved. The plate material 250 is made of, for example, stainless steel, taking into account the conditions of use of the burner body 210.

Next, as shown in FIG. 10, plate material 250A is applied to main body wall portion 211A, and repair material 240 is placed in missing portion 225 to determine the position of repair material 240 relative to plate material 250A. At this time, the position of repair material 240 may be marked on plate material 250A.

After the repair material 240 is positioned relative to the plate material 250A, the repair material 240 is attached to the plate material 250A as shown in Fig. 11. This integrates the plate material 250A and the repair material 240. The attachment is performed by, for example, welding.
Also, instead of attaching the repair material 240, which is a separate member corresponding to the shape of the missing portion 225, to the plate material 250A, a member having a portion corresponding to the plate material 250A and a portion corresponding to the repair material 240 may be integrally formed. For example, a plate material thicker than the sum of the plate thickness of the plate material 250A and the plate thickness of the repair material 240 may be cut to integrally form a plate portion shaped along the inner circumferential surface of the main body wall portion 211 (a portion corresponding to the plate material 250A along the inner circumferential surface of the main body wall portion 211) and a portion to be placed in the missing portion (a portion corresponding to the repair material 240) and place them on the main body wall portion 211A and the missing portion 225. This can be applied, for example, when the damaged portion 223 of the burner body 210 can be accurately measured and the missing portion 225 is large compared to the size of the burner nozzle 220.
A member having plate material 250A and repair material 240 is prepared by any of the above processes (manufacturing processes).

12, the plate material 250A to which the repair material 240 is connected is applied to the main body wall portion 211A. At this time, the repair material 240 connected to the plate material 250A is located in the defective portion 225 formed in the main body wall portion 211A.
In addition to the plate material 250A, plate materials 250B, 250C, and 250D having shapes conforming to the inner peripheral surfaces of the body walls 211B, 211C, and 211D are prepared, and these plate materials 250B, 250C, and 250D are also applied to the body walls 211B, 211C, and 211D, respectively, in the same manner as the plate material 250A. As a result, most of the inner peripheral surface of the body wall 211 located on the opening end side of the burner body 210 is covered by the plate material 250.
In the following description, when the positions of the plate materials are to be distinguished, the reference numerals 250A, 250B, 250C, and 250D are used. When the plate materials are collectively referred to, the reference numeral 250 is simply used.

13, other plates (connecting plates 252) corresponding to the shapes of the gaps formed between the plates 250 (gaps at the four corners of the main body wall 211) are prepared and welded to the plates 250 to form a rectangular tubular plate 250 in which the four plates 250A, 250B, 250C, and 250D are integrated. As a result, the integrated rectangular tubular plate 250 is fitted into the inner circumferential surface of the rectangular tubular main body wall 211, and the displacement of the plate 250 in all directions is regulated by the inner circumferential surface of the main body wall 211.
The shape of the connecting plate 252 may be determined by matching with the shape of the burner nozzle 220 .

In the above description, the rectangular cylindrical plate material 250 is constructed using plate materials 250A, 250B, 250C, and 250D, but for example, plate material 250C located on the top surface may be omitted to construct a three-sided U-shaped plate material 250. Even with this type of plate material 250, it is possible to fit the inner peripheral surface of the rectangular cylindrical main body wall portion 211, so that the plate material 250 can be stably connected to the inner peripheral surface of the main body wall portion 211.

Next, as shown in FIG. 14, the gap formed between the main body wall 211A and the repair material 240 is filled with a filler 260 such as ceramic putty. Also, as shown in FIG. 15, the step formed between the end of the upstream side of the plate material 250A (the side opposite the opening end of the burner main body 210) and the inner circumferential surface of the main body wall 211A is filled with a filler 260 such as ceramic putty. In this way, by smoothing out the gaps, steps, and other deformed parts with the filler 260, it is possible to reduce resistance to the flow of the mixed gas and the combustion air.

Next, as shown in FIG. 16, the burner nozzle 220 is placed at a predetermined position on the open end side of the burner body 210, and the pin member 230 is inserted into the burner nozzle 220 from the outside.
Of the integrated plate material 250, each of the plate materials 250B, 250C corresponding to the side surfaces has a hole formed therein, and by inserting the pin member 230 into each hole of the plate materials 250B, 250C simultaneously with the connection of the burner nozzle 220, the plate material 250 is connected to the main body wall portion 211 (connection process).

At this time, a gap is provided between the burner body 210 and the burner nozzle 220 so that the burner nozzle 220 can rotate smoothly. However, the burner nozzle 220 may move in the insertion direction of the pin member 230 by the amount of the gap. For this reason, for example, when the burner nozzle 220 is offset to the one side and closest to the burner body 210 (when the burner nozzle 220 comes into contact with the body wall portion 211B) as shown in Fig. 17, the burner nozzle 220 is farthest from the body wall portion 211D of the burner body 210 at the portion located on the opposite side as shown in Fig. 18.
The pin member 230 used has a length dimension such that the amount of protrusion p from the inner peripheral surface of the main body wall portion 211D is equal to or greater than the thickness t of the plate material 250D even when the burner nozzle 220 is offset in this manner. In other words, the pin member 230 used has a length such that it is flush with the inner peripheral surface of the plate material 250D or protrudes from the inner peripheral surface even when the burner nozzle 220 is offset. For this reason, the plate material 250 is configured not to come off the pin member 230 even when the burner nozzle 220 is offset relative to the burner main body 210.

According to this embodiment, the following effects are obtained.
The repair method for the burner 21 according to this embodiment includes a removal step of removing a specified portion 224 including a damaged portion 223 generated in the body wall 211A of the burner body 210 from the body wall 211A of the burner body 210; a production step of providing a repair material 240 having a shape corresponding to the missing portion 225 formed in the body wall 211A by the specified portion 224 on a plate material 250A having a shape along the inner circumferential surface of the body wall 211A; and a connection step of connecting the plate material 250A to the inner circumferential surface of the body wall 211A with the repair material 240 positioned in the missing portion 225. Therefore, even if the damaged portion 223 occurs in the body wall 211A of the burner body 210, the entire damaged portion 223 can be removed from the burner body as the specified portion 224, and the repair material 240 can be applied to the missing portion 225 of the body wall 211A formed by removing the specified portion 224. Therefore, even if a damaged portion 223 occurs in the burner body 210 that is too large to repair with putty alone, the damaged portion can be repaired quickly and in a simple manner.

In addition, since the plate material 250 to which the repair material 240 is attached is connected to the inner peripheral surface of the body wall 211, the repair material 240 can be indirectly attached to the body wall 211 (missing portion 225) of the burner body 210 without changing the outer shape of the body wall 211, i.e., the outer shape of the burner body 210. Therefore, when providing other parts (e.g., the burner nozzle 220, etc.) around the burner body 210, no restrictions are imposed on the installation or operation of the other parts.

In addition, after the connection process, a process of providing a filler 260 at the boundary between the burner body 210 and the plate material 250 and/or the boundary between the burner body 210 and the repair material 240 is included, so that the shape change portion (step, gap, etc.) that may occur between the burner body 210 and the plate material 250 and/or the shape change portion (step, gap, etc.) that may occur between the burner body 210 and the repair material 240 can be formed into a smooth shape by the filler 260. The filler 260 is, for example, a putty material such as ceramic putty.

The burner body 210 has a body wall 211 on the open end side located downstream in the flow direction of the mixed gas, which is a square tube with four sides, and the plate material 250 is formed so as to contact at least three sides of the inner circumferential surface of the body wall 211, so that the plate material 250 can be stably connected to the inner circumferential surface of the body wall 211. Also, for example, when the plate material 250 is formed so as to contact the inner circumferential surfaces of all the body walls 211, the displacement of the plate material 250 in all directions is restricted by the inner circumferential surface of the body wall 211, so that thermal deformation that may occur in the plate material 250 can be suppressed.

The burner 21 also includes a cylindrical burner nozzle 220 that guides the mixed gas and combustion air flowing out of the burner body 210 into the furnace. The burner nozzle 220 is cylindrical and surrounds the outer peripheral surface of the open end side of the burner body 210. The burner nozzle 220 is rotatably connected to the burner body 210 using pin members 230 provided on each of the two opposing body walls 211B and 211D as fulcrums. The plate material 250 is connected to the inner peripheral surface of the body wall 211 by the pin members 230, so that the plate material 250 can be connected to the body wall 211 using the pin members 230 for connecting the movable burner nozzle 220 to the burner body 210. This allows the plate material 250 to be connected to the body wall 211 regardless of the material of the burner body 210. For example, even if the burner body 210 is made of cast steel that is not suitable for welding, the plate material 250 can be connected to the body wall 211 without welding.

In addition, by setting the dimensions of the pin member 230 such that when the body wall 211 (e.g. 211B) into which one pin member 230 is inserted approaches the burner nozzle 220 in the insertion direction of the pin member 230, the projection amount p of the pin member 230 projecting from the inner peripheral surface of the body wall 211 (e.g. 211D) into which the other pin member 230 is inserted is equal to or greater than the plate thickness t of the plate material 250 (e.g. 250D), the plate material 250 does not come off the pin member 230 even if the burner nozzle 220 is biased relative to the burner body 210. Therefore, even if the burner nozzle 220 is biased relative to the burner body 210, the plate material 250 does not fall off the burner body 210.

[Second embodiment]
The second embodiment of the present disclosure will be described below.
This embodiment differs from the first embodiment in that it does not use the repair material 240. Therefore, the same components are denoted by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 19, in the body wall 211A, the damaged area 223 caused by the use of the burner 21 can be made into a missing portion 225 of the body wall 211A. In this way, by making the damaged area 223 itself into the missing portion 225, the removal process of cutting the specified portion 224 from the body wall 211A can be omitted.

As in the first embodiment, a predetermined portion 224 including the damaged portion 223 may be cut from the body wall portion 211A to form the missing portion 225.

Next, as shown in FIG. 20, a plate material 250 is applied to the body wall portion 211 so as to cover the missing portion 225 .
At this time, repair material 240 is not provided on defective portion 225. This is useful, for example, when the area of defective portion 225 is smaller than the area of main body wall portion 211A, or when defective portion 225 is simply a thinning or a crack.

The connection process and the process of smoothing out any shape changes that may occur between the burner body 210 and the plate material 250 using the filler material 260 are the same as in the first embodiment described above.

According to this embodiment, the following effects are obtained.
The method for repairing the burner 21 according to this embodiment includes a connecting step for connecting a plate material 250 along the inner peripheral surface of the body wall 211 of the burner body 210 to the inner peripheral surface of the body wall 211 so as to cover the defective portion 225 formed in the body wall 211 of the burner body 210, so that even if a defective portion 225 occurs in the body wall 211A of the burner body 210, the plate material 250 can be applied to the defective portion 225 from the inner peripheral surface side. Therefore, the defective portion 225 can be repaired quickly and in a simple manner.

In addition, because the plate material 250 is connected to the inner peripheral surface of the body wall portion 211, the outer shape of the body wall portion 211, i.e., the outer shape of the burner body 210, is not changed. Therefore, when providing other parts (e.g., the burner nozzle 220, etc.) around the burner body 210, no restrictions are imposed on the installation or operation of the other parts.

In addition, after the connection process, a process of providing a filler 260 at the boundary between the burner body 210 and the plate material 250 is included, so that any shape changes (steps, gaps, etc.) that may occur between the burner body 210 and the plate material 250 can be molded into a smooth shape by the filler 260. The filler 260 is, for example, a putty material such as ceramic putty.

The burner body 210 has a body wall 211 on the open end side located downstream in the flow direction of the mixed gas, which is a square tube with four sides, and the plate material 250 is formed so as to contact at least three sides of the inner circumferential surface of the body wall 211, so that the plate material 250 can be stably connected to the inner circumferential surface of the body wall 211. Also, for example, when the plate material 250 is formed so as to contact the inner circumferential surfaces of all the body walls 211, the displacement of the plate material 250 in all directions is restricted by the inner circumferential surface of the body wall 211, so that thermal deformation that may occur in the plate material 250 can be suppressed.

The burner 21 also includes a cylindrical burner nozzle 220 that guides the mixed gas and combustion air flowing out of the burner body 210 into the furnace. The burner nozzle 220 is cylindrical and surrounds the outer peripheral surface of the open end side of the burner body 210. The burner nozzle 220 is rotatably connected to the burner body 210 with the pin members 230 provided on each of the two opposing body walls 211B and 211D as fulcrums. The plate material 250 is connected to the inner peripheral surface of the body wall 211 by the pin members 230, so that the plate material 250 can be connected to the body wall 211 with the pin member 230 for connecting the movable burner nozzle 220 to the burner body 210 as a fulcrum. This allows the plate material 250 to be connected to the body wall 211 regardless of the material of the burner body 210. For example, even if the burner body 210 is made of cast iron, which is not suitable for welding, the plate material 250 can be connected to the body wall 211 without welding.

In addition, by setting the dimensions of the pin member 230 such that when the body wall 211 (e.g. 211B) into which one pin member 230 is inserted approaches the burner nozzle 220 in the insertion direction of the pin member 230, the projection amount p of the pin member 230 projecting from the inner peripheral surface of the body wall 211 (e.g. 211D) into which the other pin member 230 is inserted is equal to or greater than the plate thickness t of the plate material 250 (e.g. 250D), the plate material 250 does not come off the pin member 230 even if the burner nozzle 220 is biased relative to the burner body 210. Therefore, even if the burner nozzle 220 is biased relative to the burner body 210, the plate material 250 does not fall off the burner body 210.

In addition, if the missing portion 225 is a damaged area 223 that has occurred in the body wall portion 211 of the burner body 210, the damaged area 223, such as wear, burnout, etc., that has occurred during use of the burner 21, can be easily repaired with the plate material 250.

In addition, when the missing portion 225 is formed by removing a specific portion 224 including the damaged portion 223 from the wall portion, the damaged portion 223, for example due to wear, burning, or the like caused by the use of the burner 21, can be completely removed from the main body wall portion 211, and the missing portion 225 can be repaired with a plate material 250.

The first embodiment described above can be understood, for example, as follows.
That is, a method for repairing a burner (21, 22, 23, 24, 25) according to one aspect of the present disclosure is a method for repairing a burner (21, 22, 23, 24, 25) having a cylindrical burner body (210) through which a mixed gas containing fuel flows, the method comprising the steps of: removing a predetermined portion (224) including a damaged portion (223) generated in a wall portion (211) of the burner body (210) from the wall portion (211) of the burner body (210) to a predetermined portion (224) including a damaged portion (223) generated in a wall portion (211) of the burner body (210) by removing the damaged portion (224) from the wall portion (211) of the burner body (210) by removing the damaged portion (224) from the wall portion (211) of the burner body (210) by removing the damaged portion (223 ... The method includes a removing process, a manufacturing process of providing a repair material (240) having a shape corresponding to the missing portion (225) formed in the wall portion (211) by the specified portion (224) on a plate material (250) having a shape along the inner surface of the wall portion (211), and a connecting process of connecting the plate material (250) to the inner surface of the wall portion (211) with the repair material (240) positioned in the missing portion (225).

The method for repairing the burner (21, 22, 23, 24, 25) according to this embodiment includes a removing step of removing a predetermined portion (224) including a damaged portion (223) generated in the wall portion (211) of the burner body (210) from the wall portion (211) of the burner body (210); a manufacturing step of providing a repair material (240) having a shape corresponding to a defective portion (225) formed in the wall portion (211) by the predetermined portion (224) on a plate material (250) having a shape along the inner circumferential surface of the wall portion (211); and a connecting step of connecting the plate material (250) to the inner peripheral surface of the wall portion (211) while the plate material is positioned at the missing portion (225). Therefore, even if a damaged portion (223) occurs in the wall portion (211) of the burner body (210), the entire damaged portion (223) can be removed from the burner body (210) as a predetermined portion (224), and the missing portion (225) of the wall portion (211) formed by removing the predetermined portion (224) can be filled with a repair material (240). Therefore, even if a damaged portion (223) occurs in the burner body (210) that is too large to be repaired with putty alone, it can be repaired quickly and in a simple manner.
In addition, since the plate material (250) provided with the repair material (240) is connected to the inner peripheral surface of the wall portion (211), the repair material (240) can be indirectly attached to the wall portion (211) of the burner body (210) without changing the outer shape of the wall portion (211), i.e., the outer shape of the burner body (210). Therefore, when providing other parts (e.g., the burner nozzle (220), etc.) around the burner body (210), no restrictions are imposed on the installation or operation of the other parts.

In addition, the method for repairing the burners (21, 22, 23, 24, 25) according to one embodiment of the present disclosure includes, after the connection step, a step of providing a filler material (260) at the boundary between the burner body (210) and the plate material (250) and/or at the boundary between the burner body (210) and the repair material (240).

The repair method for the burners (21, 22, 23, 24, 25) according to this embodiment includes a step of providing a filler (260) at the boundary between the burner body (210) and the plate material (250) and/or the boundary between the burner body (210) and the repair material (240) after the connection step, so that the shape change portion (step, gap, etc.) that may occur between the burner body (210) and the plate material (250) and/or the shape change portion (step, gap, etc.) that may occur between the burner body (210) and the repair material (240) can be formed into a smooth shape by the filler (260). The filler (260) is, for example, a putty material such as ceramic putty.

In addition, in a method for repairing a burner (21, 22, 23, 24, 25) according to one aspect of the present disclosure, the burner body (210) has a wall portion (211) on the open end side located downstream in the flow direction of the mixed gas, which is a square tube having four sides, and the plate material (250) is formed so as to contact at least three sides of the inner circumferential surface of the wall portion (211).

In the repair method for the burner (21, 22, 23, 24, 25) according to this embodiment, the wall (211) of the burner body (210) at the open end located downstream in the flow direction of the mixed gas is a square tube having four sides, and the plate material (250) is formed so as to contact at least three sides of the inner peripheral surface of the wall portion (211), so that the plate material (250) can be stably connected to the inner peripheral surface of the wall portion (211). In addition, for example, when the plate material (250) is formed so as to contact the inner peripheral surfaces of all the wall portions (211), the displacement of the plate material (250) in all directions is restricted by the inner peripheral surfaces of the wall portions (211), so that thermal deformation that may occur in the plate material (250) can be suppressed.

In addition, in a method for repairing a burner (21, 22, 23, 24, 25) according to one embodiment of the present disclosure, the burner is provided with a burner nozzle (220) that guides the mixed gas and combustion air flowing out from the burner body (210) into the furnace, the burner nozzle (220) is cylindrical and surrounds the outer peripheral surface of the open end side of the burner body (210), the burner body (210) and the burner nozzle (220) are rotatably connected at opposing positions with two pin members (230) as fulcrums, and the plate material (250) is connected to the inner peripheral surface of the wall portion (211) by the pin members (230).

In the method for repairing the burner (21, 22, 23, 24, 25) according to the present embodiment, the burner is provided with a burner nozzle (220) that guides the mixed gas and combustion air flowing out from the burner body (210) into the furnace, the burner nozzle (220) is cylindrical and surrounds the outer peripheral surface of the open end side of the burner body (210), the burner nozzle (220) is rotatably connected to the burner body (210) with the pin members (230) provided on each of the two opposing wall portions (211) as fulcrums, and the plate material (250) is connected to the inner peripheral surface of the wall portion (211) by the pin members (230), so that the plate material (250) can be connected to the wall portion (211) with the pin members (230) for connecting the movable burner nozzle (220) to the burner body (210) as a fulcrum for rotation. This allows the plate material (250) to be connected to the wall portion (211) regardless of the material of the burner body (210). For example, even if the burner body (210) is made of cast iron, which is not suitable for welding, the plate material (250) can be connected to the wall portion (211) without welding.

In addition, in a method for repairing a burner (21, 22, 23, 24, 25) according to one aspect of the present disclosure, the dimensions of the pin member (230) are set so that when the wall portion (211) on which one of the pin members (230) is provided approaches the burner nozzle (220) in the direction of insertion of the pin member (230), the amount of protrusion of the pin member (230) from the inner peripheral surface of the wall portion (211) into which the other pin member (230) is inserted is equal to or greater than the thickness of the plate material (250).

In the repair method for the burners (21, 22, 23, 24, 25) according to this embodiment, when the wall portion (211) into which one pin member (230) is inserted approaches the burner nozzle (220) in the insertion direction of the pin member (230), the pin member (230) has a dimension set such that the amount of protrusion of the pin member (230) from the inner peripheral surface of the wall portion (211) into which the other pin member (230) is inserted is equal to or greater than the thickness of the plate material (250). This prevents the plate material (250) from coming off the pin member (230) even if the burner nozzle (220) is biased toward the burner body (210). Therefore, even if the burner nozzle (220) is biased toward the burner body (210), the plate material (250) does not fall off the burner body (210).

The burner (21, 22, 23, 24, 25) according to one embodiment of the present disclosure comprises a burner body (210) having a cylindrical shape surrounded by a wall portion (211) from which a predetermined portion (224) of the wall portion (211) has been removed, a plate material (250) connected to the inner peripheral surface of the wall portion (211) so as to follow the inner peripheral surface of the wall portion (211), and a repair material (240) that is shaped to correspond to a defective portion (225) formed in the wall portion (211) by the predetermined portion (224) and is provided on the plate material (250) while being positioned at the defective portion (225).

Furthermore, the boiler (10) according to one embodiment of the present disclosure is equipped with the burners (21, 22, 23, 24, 25) described above.

In addition, a power generation plant according to one embodiment of the present disclosure includes the above-mentioned boiler (10) and a power generation unit that generates power using steam generated by the boiler (10).

10. Coal-fired boiler (boiler)
11 Furnace 12 Combustion device 13 Combustion gas passage 14 Flue 21, 22, 23, 24, 25 Burner 26, 27, 28, 29, 30 Pulverized coal supply pipe 31, 32, 33, 34, 35 Pulverizer (mill)
36 Wind box 37 Air duct (airway)
38 Forced draft fan (FDF)
41 Gas duct 42 Air heater (air preheater)
43 Denitrification device 44 Dust collector 45 Induced draft fan (IDF)
46 Desulfurization device 50 Chimney 101 Furnace wall 102 First superheater (heat exchanger)
103 Second superheater (heat exchanger)
104 Third superheater (heat exchanger)
105 First reheater (heat exchanger)
106 Second reheater (heat exchanger)
107 Energy saver (heat exchanger)
210 Burner body 211 (211A, 211B, 211C, 211D) Body wall (wall)
220 Burner nozzle 221 Nozzle outer wall 222 Nozzle inner wall 223 Damaged portion 224 Predetermined portion 225 Missing portion 230 Pin member 240 Repair material 250 (250A, 250B, 250C, 250D) Plate material 252 Connection plate material 260 Filler material MP1 Main body side primary flow path MP2 Main body side secondary flow path NP1 Nozzle side primary flow path NP2 Nozzle side secondary flow path

Claims (8)

A method for repairing a burner having a cylindrical burner body through which a mixed gas containing fuel flows, comprising the steps of:
a removing step of removing a predetermined portion including a damaged portion from the wall portion of the burner body;
a manufacturing process of providing a repair material having a shape corresponding to the missing portion formed in the wall portion by the predetermined portion on a plate material having a shape along an inner circumferential surface of the wall portion;
a connecting step of connecting the plate material to an inner circumferential surface of the wall portion with the repair material positioned in the missing portion;
A method for repairing a burner comprising: The burner repair method according to claim 1, further comprising a step of providing a filler material at the boundary between the burner body and the plate material and/or the boundary between the burner body and the repair material after the connecting step. The burner body has an opening end located downstream in a flow direction of the mixed gas, and the wall portion has a rectangular cylindrical shape having four sides,
3. The method for repairing a burner according to claim 1, wherein the plate material is formed so as to be in contact with at least three faces of an inner circumferential surface of the wall portion. The burner includes a burner nozzle for introducing the mixed gas and the combustion air flowing out from the burner body into the furnace,
The burner nozzle is cylindrical and surrounds the outer circumferential surface of the open end side of the burner body,
The burner body and the burner nozzle are rotatably connected to each other at opposing positions using two pin members as fulcrums,
The method for repairing a burner according to claim 3 , wherein the plate material is connected to the inner circumferential surface of the wall portion by the pin member. The burner repair method according to claim 4, wherein the dimensions of the pin members are set so that when the wall portion on which one of the pin members is provided approaches the burner nozzle in the direction of insertion of the pin members, the amount of protrusion of the pin member from the inner peripheral surface of the wall portion on which the other pin member is inserted is equal to or greater than the thickness of the plate material. A burner body having a cylindrical shape surrounded by a wall portion, with a predetermined portion of the wall portion removed;
A plate material connected to the inner circumferential surface of the wall portion so as to extend along the inner circumferential surface of the wall portion;
A repair material that is shaped to correspond to a defective portion formed in the wall portion by the predetermined portion and is provided on the plate material while being positioned in the defective portion;
A burner equipped with A boiler equipped with the burner according to claim 6. A boiler according to claim 7;
a power generation unit that generates electricity using steam generated by the boiler;
A power plant comprising:

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