JP6993842B2 - Boiler, steam temperature adjustment method, and refractory for boiler - Google Patents

Description

The present disclosure relates to boilers and refractories for boilers.

In general, it is very difficult to take measures when the heat transfer area of the boiler is insufficient, so it is often the case that the heat transfer area has a margin at the time of designing, which causes the steam temperature to exceed the design temperature. It can happen. In particular, in biomass-burning boilers, which are expected to increase in the future, the properties (moisture content, etc.) of biomass used as fuel are extremely unstable and it is difficult to make accurate predictions, so there is a high possibility that such a situation will occur. Therefore, in order to adjust the temperature of steam in the boiler, various studies have been made on a structure using a water spray and a structure in which the heat transfer area between the exhaust gas and the heat exchanger can be changed.

In Patent Documents 1 and 2, in order to adjust the steam temperature, a partition plate is provided in the flue through which the exhaust gas flows so as to shield a part of the heat exchanger, and heat transfer is performed by changing the flow path width of the exhaust gas. A temperature control device capable of adjusting the area is disclosed. Further, Patent Document 1 discloses that a damper abutting on a partition plate is provided, and the heat transfer area is adjusted by changing the flow path width of the exhaust gas by adjusting the damper.

Jitsukaisho 61-204119 Jitsukaisho 60-160308 Gazette

However, even if the heat transfer area is limited in an attempt to lower the steam temperature, the flow velocity of the gas actually increases as the flow path width narrows, and the heat transfer efficiency of the heat exchanger increases. Therefore, the effect of reducing the steam temperature may be limited. In addition, since the temperature of the exhaust gas is usually as high as 1000 degrees or more, it is actually difficult to install a movable device such as a damper in such an environment, and even if it is installed, the durability of the damper is improved. Problems can arise. It is conceivable to lower the exhaust gas temperature to the heat resistant temperature of the damper, but in that case, it is necessary to take measures such as installing an evaporation pipe in the exhaust gas flow path, which leads to an increase in cost.

Therefore, an object of at least one embodiment of the present invention is to provide a boiler and a refractory for the boiler whose steam temperature can be easily adjusted by a simple configuration in view of the above circumstances.

(1) The boiler according to some embodiments of the present invention is
The flue that forms the exhaust gas flow path through which the exhaust gas discharged from the furnace flows,
A heat exchanger provided in the exhaust gas flow path for overheating steam,
A bypass flue forming a bypass flow path that branches from the upstream side of the heat exchanger in the exhaust gas flow path and joins the downstream side of the heat exchanger.
It includes at least one refractory material stacked so as to block at least a part of the cross section of the bypass flow path.

According to the configuration of (1) above, when it is desired to raise the steam temperature, a large amount of exhaust gas can be passed through the heat exchanger by stacking refractory materials and blocking the cross section of the bypass flow path. On the other hand, when it is desired to lower the steam temperature, the flow of exhaust gas toward the bypass flow path is generated by removing the accumulated refractory, and the flow rate of the exhaust gas passing through the heat exchanger can be reduced. In this way, the steam temperature can be easily adjusted by changing the degree of blockage of the cross section of the bypass flow path and increasing or decreasing the flow rate of the exhaust gas passing through the heat exchanger by a simple method of simply stacking refractories. Can be done.

(2) In some embodiments, in the configuration of (1) above,
The flue contains a plurality of tubes extending along the vertical direction.
The refractory material is fitted between a pair of tubes adjacent to each other in a direction intersecting the flow direction of the bypass flow path at a branching point of the bypass flow path from the exhaust gas flow path.

According to the configuration of (2) above, the refractory is fitted between a pair of tubes adjacent to each other in the direction intersecting the flow direction of the bypass flow path at the branch point of the bypass flow path from the exhaust gas flow path. Is done. Therefore, refractories can be stacked by utilizing the space formed between the tubes. Further, by fitting the refractory material between the pair of tubes, it is possible to prevent the stacked refractory material from falling off.

(3) In some embodiments, in the configuration of (2) above,
The refractory has recesses at both ends of the refractory that abut on the outer peripheral surfaces of each of the pair of tubes.

According to the configuration of (3) above, the stacked refractories come into contact with the outer peripheral surface of the tube at the recesses at both ends thereof, so that the refractory is more difficult to fall off from between the tubes. This makes it possible to avoid damage to the boiler that may occur due to the fall of the refractory.

(4) In some embodiments, in the configuration of (3) above,
The refractory is a first portion and a second portion that are divided along the axial direction of the tube, the first portion that abuts on one of the adjacent pair of tubes, and the adjacent portion. Includes a second portion of the pair of tubes that contacts the other tube.
A first partition plane is formed on the first portion.
A second division surface that abuts on the first division surface is formed in the second portion.

According to the configuration of (4) above, the refractory is divided into a first portion and a second portion along the axial direction of the tube. The first portion is formed so as to abut on one side of the pair of adjacent tubes and the second portion abuts on the other side of the pair of adjacent tubes. Therefore, when stacking refractories between a pair of adjacent tubes, for example, the first portion can be installed so as to be in contact with one side of the tube, and then the second portion can be installed so as to be in contact with the other side of the tube. Therefore, it becomes easy to stack and remove refractories between a pair of adjacent tubes.

(5) In some embodiments, in the configuration of (4) above,
The first partition surface has a first tapered surface extending in a direction in which at least a part of the first partition surface intersects the axial direction of the tube.
The second divided surface is a second tapered surface in which at least a part of the second divided surface extends in a direction intersecting the axial direction of the tube, and is a second tapered surface that abuts on the first tapered surface. It has a tapered surface.

According to the configuration of (5) above, each of the first division surface and the second division surface is a tapered surface (first taper) in which at least a part of the first division surface extends in a direction intersecting the axial direction of the tube and abuts on each other. It has a surface, a second tapered surface). Therefore, on the tapered surface, a pressing force acting downward in the vertical direction is generated with respect to the first portion to the second portion or the second portion to the first portion. On the other hand, due to the pressing force, each recess of the refractory and each pair of tubes in contact with each recess are in close contact with each other, and the refractory can be firmly fixed between the pair of adjacent tubes. As a result, refractories can be stacked between the pair of tubes with the first portion and the second portion in close contact with each other. Therefore, it is possible to suppress the rattling of the stacked refractories with a simple configuration.

(6) In some embodiments, in the configuration of (4) or (5) above,
The first partition plane has a convex portion protruding toward the second partition plane.
The second dividing surface has a recess that can accept the convex portion.

According to the configuration of (6) above, the first portion and the second portion can be installed so that the convex portion of the first division surface is fitted into the concave portion of the second division surface. Therefore, it is possible to suppress the deviation and separation between the first portion and the second portion, and make it difficult for the stacked refractories to fall out from between the tubes. This makes it possible to effectively avoid damage to the boiler that may occur due to the fall of the refractory.

(7) In some embodiments, in any one of the above (1) to (6) configurations.
The refractory material includes bricks.

According to the configuration of (7) above, the cross-sectional area of the bypass flow path can be easily adjusted only by stacking or removing bricks having excellent fire resistance, handleability, and cost.

(8) In some embodiments, in any one of the above (1) to (7) configurations.
Fuel containing biomass is burned in the furnace. That is, the boiler of the present embodiment is configured as a biomass combustion boiler that burns a fuel containing biomass (including a single biomass and a mixture of pulverized coal and biomass) in a furnace.

The properties (moisture content, etc.) of biomass may differ greatly depending on the place of production, transportation / storage conditions, and the like. For this reason, the biomass combustion boiler is likely to fall into a situation where the steam temperature exceeds the design temperature.
According to the configuration of (8) above, in such a biomass combustion boiler, the exhaust gas passing through the heat exchanger is changed in the degree of blockage of the cross section of the bypass flow path by a simple method of simply stacking refractory materials. The steam temperature can be easily adjusted by increasing or decreasing the flow rate of.

(9) The method for adjusting the steam temperature of the boiler according to some embodiments of the present invention is as follows.
The steam temperature adjusting method in the boiler according to any one of (1) to (8) above.
A temperature measurement step for measuring the temperature of steam superheated by the heat exchanger, and
A difference calculation step for calculating the difference between the measured temperature of the steam measured in the temperature measurement step and a predetermined planned temperature, and a difference calculation step.
Based on the difference calculated in the difference calculation step, the refractory number adjustment step for adjusting the number of the at least one refractory material stacked so as to block the flow path cross section of the bypass flow path, and the refractory number adjustment step.
To prepare for.

As described above, in the boiler according to some embodiments of the present invention, when it is desired to raise the steam temperature, a large amount of exhaust gas passes through the heat exchanger by stacking refractories and blocking the cross section of the bypass flow path. Can be made to. On the other hand, when it is desired to lower the steam temperature, the flow of exhaust gas toward the bypass flow path is generated by removing the accumulated refractory, and the flow rate of the exhaust gas passing through the heat exchanger can be reduced.
Therefore, according to the configuration of (9) above, when the difference between the measured temperature and the planned temperature is larger than a predetermined value, for example, when the measured temperature> the planned temperature, the accumulated fireproof material is removed and the measured temperature < In the case of the planned temperature, the measured temperature can be brought closer to the planned temperature by stacking fireproof materials and blocking the flow path cross section of the bypass flow path.

(10) The refractory material for a boiler according to some embodiments of the present invention is
A refractory material for boilers that is fitted between a pair of adjacent tubes.
The refractory has recesses (arc-shaped) in contact with the outer peripheral surfaces of each of the pair of tubes at both ends of the refractory.
The refractory is a first portion and a second portion divided along the axial direction of the tube, the first portion of the pair of tubes abutting on one side of the tube, and the adjacent pair. Includes a second portion of the tube that contacts the other tube.

According to the configuration of (10) above, the stacked refractories come into contact with the outer peripheral surface of the tube at the recesses at both ends thereof, so that the refractory is more difficult to fall off from between the tubes. This makes it possible to avoid damage to the boiler that may occur due to the fall of the refractory. Further, the refractory material is divided into a first portion and a second portion along the axial direction of the tube. The first portion is formed so as to abut on one side of the pair of adjacent tubes and the second portion abuts on the other side of the pair of adjacent tubes. Therefore, when stacking refractories between a pair of adjacent tubes, for example, the first portion can be installed so as to be in contact with one side of the tube, and then the second portion can be installed so as to be in contact with the other side of the tube. Therefore, it becomes easy to stack and remove refractories between a pair of adjacent tubes.

According to at least one embodiment of the present invention, it is possible to provide a boiler and a refractory material for the boiler whose steam temperature can be easily adjusted by a simple configuration.

It is a schematic diagram which shows the whole structure of the boiler which concerns on some embodiments. It is a figure which shows the structure of the branch part and the confluence part which concerns on some embodiments. It is a figure which looked at each of the two types of cross sections in FIG. 2 from directly above. It is a figure which showed by extracting a part of the exhaust gas communication part in FIG. It is a figure which looked at the cross section of CC'in FIG. 4 from directly above. It is a perspective view of the refractory thing which concerns on some embodiments. It is a figure which shows the modification of the refractory material which concerns on some Embodiments. It is a flow diagram for demonstrating the steam temperature method in the boiler which concerns on some embodiments. It is a map showing the relationship between the blockage rate of the cross section of the flow path and the difference between the measured difference temperature and the planned temperature according to some embodiments.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely explanatory examples. do not have.

First, with reference to FIG. 1, the overall structure of the boiler according to some embodiments will be described. FIG. 1 is a schematic view showing the overall configuration of the boiler 100 according to some embodiments.

As shown in FIG. 1, the boiler 100 according to some embodiments has a furnace wall 3 forming a combustion field 10 inside and a flue 35 forming an exhaust gas flow path 30 on the downstream side of the furnace 10. To prepare for. The furnace 10 has a hollow shape and is provided along the vertical direction, and the furnace wall 3 constituting the furnace 10 is composed of a heat transfer tube (not shown) extending along the vertical direction. In such a boiler 100, fuel F such as coal supplied from the outside is burned in the furnace 10, and the exhaust gas generated there is passed through the heat exchanger 5 provided in the exhaust gas flow path 30, so that the heat exchanger 100 is used. The temperature of the steam introduced in 5 can be raised.

In some embodiments, the fuel F containing biomass is burned in the furnace 10. That is, the boiler 100 of the present embodiment is configured as a biomass combustion boiler in which the fuel F containing biomass (including a single biomass and a mixture of pulverized coal and biomass) is burned in the furnace 10.

The steam drum 7 is connected to each heat transfer tube (not shown) of the furnace wall 3 and is connected to the heat exchanger 5 via the steam line 9. When the steam introduced into the heat exchanger 5 exchanges heat with the high-temperature exhaust gas in the exhaust gas flow path 30 to raise the temperature, water W is introduced by the overheat reducer 13 via the steam line 11. This is adjusted to the desired temperature. After that, the steam S is supplied to an external turbine (not shown).

As shown in FIG. 1, the boiler 100 according to some embodiments branches at a branch portion 31 on the upstream side of the heat exchanger 5 in the exhaust gas flow path 30, and is a confluence portion located on the downstream side of the heat exchanger 5. It includes a bypass flue 41 forming a bypass flow path 40 that joins at 33, and at least one refractory material 50 stacked so as to block at least a part of the flow path cross section in the bypass flow path 40. The bypass flue 41 is formed, for example, by a duct or the like connecting the branch portion 31 and the merging portion 33.
Here, stacking means placing at least one refractory material 50 on an arbitrary installation surface in the flue 35 or the bypass flue 41 until the desired height is reached (the refractory materials 50 are sequentially stacked over a plurality of stages). Also includes).

According to the present embodiment, when it is desired to raise the steam temperature, a large flow rate of exhaust gas can be passed through the heat exchanger 5 by stacking the refractory materials 50 and narrowing the cross section of the bypass flow path 40, and steam. The amount of heat exchange with and can be increased. On the other hand, when it is desired to lower the steam temperature, the flow rate of the exhaust gas toward the bypass flow path 40 can be increased and the flow rate of the exhaust gas passing through the heat exchanger 5 can be reduced by removing the stacked refractory materials 50. In this way, by simply stacking and removing the refractory materials 50, the degree of blockage of the cross section of the bypass flow path 40 is changed to increase or decrease the flow rate of the exhaust gas passing through the heat exchanger 5. , The steam temperature can be easily adjusted.

In the embodiment shown in FIG. 1, the refractory material 50 is stacked on the branch portion 31 to block the cross section of the bypass flow path 40, but in other embodiments, the refractory material 50 is stacked on the confluence portion 33. The cross section of the flow path may be blocked.

Further, the location where the refractory material 50 is stacked may be between the branch portion 31 and the confluence portion 33, and can be appropriately selected depending on the structure of the bypass flue 41, the flow rate of the exhaust gas, and other conditions.

Also, in some embodiments, the refractory 50 comprises bricks. This makes it possible to easily adjust the cross-sectional area of the bypass flow path 40 simply by stacking or removing bricks that are excellent in terms of fire resistance, handleability, and cost.

The refractory material 50 is not limited to the above embodiment, and may be any object that retains its shape without being burned or melted by high-temperature exhaust gas. For example, it may be a castable refractory of an amorphous refractory, a plastic refractory and a refractory mortar, a heat-resistant steel material, or the like.

Here, the structure of the branch portion 31 and the confluence portion 33 between the bypass flow path 40 and the exhaust gas flow path 30 according to some embodiments will be described with reference to FIGS. 2 and 3. FIG. 2 is a diagram showing the configuration of the branch portion 31 and the confluence portion 33 according to some embodiments. FIG. 3 shows a view of each of the two types of cross-sectional views in FIG. 2 viewed from directly above.

The flue 35 forming the exhaust gas flow path 30 is formed by connecting a plurality of tubes 21 extending in the vertical direction arranged at predetermined intervals to each other by a seal fin 23. Therefore, the branch portion 31 and the confluence portion 33 between the exhaust gas flow path 30 and the bypass flow path 40 are originally closed by at least one tube 21 and the seal fin 23, so that the exhaust gas flows into the bypass flow path 40. There is no space.

Therefore, in some embodiments, as shown in FIG. 2, the exhaust gas is discharged by deforming a part (21B, 21D) of the plurality of tubes 21 (21A to 21E) in the branch portion 31 and the confluence portion 33. An exhaust gas communication portion 25 for flowing into the bypass flow path 40 is formed. In FIG. 2, the direction orthogonal to the illustrated axial direction and the axis orthogonal direction (paper depth direction) is the flow direction of the bypass flow path 40, and the exhaust gas flows from the front side to the back side of the paper surface. In the example shown in FIG. 2, in one of the adjacent tubes 21A and 21B, a part of the tube 21B in the axial direction is bent toward the downstream side in the flow direction of the bypass flow path 40. Further, in one of the adjacent tubes 21C and 21D, a part of the tube 21D in the axial direction is bent toward the downstream side in the flow direction of the bypass flow path 40.
(A) of FIG. 3 shows a view of the cross section of AA'in FIG. 2 seen from directly above. In the AA'cross section, since the tubes 21B and 21D are not bent, the plurality of tubes 21 (21A to 21E) are connected by the seal fins 23. FIG. 3B is a cross-sectional view taken along the line BB'in FIG. In the BB'cross section, the tube 21B and the tube 21D are bent toward the downstream side in the flow direction of the bypass flow path 40. By removing the seal fin 23 in the bent part, the part originally closed by the tube 21 and the seal fin 23 like the AA'cross section can be opened like the BB' cross section. It is possible to form a space through which the exhaust gas passes (exhaust gas communication portion 25).

Focusing on the adjacent tubes 21A and 21B in the AA'cross section, in the BB' cross section, the axis of one tube 21B is on the downstream side of the axis of the other tube 21A in the flow direction of the bypass flow path 40. It is bent diagonally with respect to the flow direction of the bypass flow path 40 so as to be located at. As a result, it is possible to suppress a situation in which the flow of the exhaust gas flowing into the bypass flow path 40 is obstructed by the bent tube 21B.
As described above, in some embodiments, the tubes (21A, 21C, 21E) extending along the axial direction and a part of the axial direction are bent toward the downstream side in the flow direction of the bypass flow path 40. The tubes (21B, 21D) are arranged alternately to form the exhaust gas communication portion 25 in an iron grid pattern.

It is not always necessary to bend the tube 21 to form the exhaust gas communication portion 25 of the branch portion 31 and the merging portion 33 as in the above embodiment. For example, in another embodiment, the exhaust gas communication portion 25 may be formed by simply removing at least a part of the seal fins 23 in the axial direction between the tubes 21.

Here, in the region blocked by the tube 21 and the seal fin 23 in the axial direction as in the AA'cross section of FIG. 3A, the "adjacent pair of tubes" is, for example, the tube 21A and the tube. Refers to 21B, tube 21C, tube 21D, and the like. In FIG. 3A, the tubes 21A, 21B, 21C, 21D, and 21E are arranged in this order, and the pair of adjacent tubes are connected by the seal fins 23.
On the other hand, in the region where the exhaust gas communication portion 25 is formed in the axial direction as in the cross section of BB'in FIG. Note that it refers to tubes 21D, tubes 21E, etc.

FIG. 4 is a diagram showing a part of the exhaust gas communication portion 25 in FIG. 2 extracted.
In some embodiments, as shown in FIGS. 3B and 4, the refractory 50 is at a branch (branch 31, confluence 33) of the bypass flow path 40 from the exhaust gas flow path 30. It is fitted between a pair of tubes 21 adjacent to each other in a direction intersecting the flow direction of the bypass flow path 40.
In the example shown in FIG. 3B, the refractory material 50 is fitted between a pair of tubes 21 (21A and 21C and 21C and 21E) adjacent to each other in the direction orthogonal to the axis in the region where the exhaust gas communication portion 25 is formed. It has been. However, the present embodiment is not limited to this, and the pair of tubes 21 into which the refractory material 50 is fitted may be positioned so as to intersect the flow direction of the bypass flow path 40. That is, for example, the refractory material 50 may be fitted between the tube 21B and the tube 21C, between the tube 21A and the tube 21D, between the tube 21D and the tube 21E, and the like. In this way, the refractory material 50 is fitted between the pair of tubes 21 adjacent to each other in the direction intersecting the flow direction of the bypass flow path 40, so that the cross section of the flow path of the bypass flow path 40 is closed by the refractory material 50. Can be done.

According to this embodiment, the refractory materials 50 can be stacked by utilizing the space formed between the tubes 21. Further, by fitting the refractory material 50 between the pair of tubes 21, it is possible to prevent the stacked refractory materials 50 from falling off.

Further, in one embodiment, as shown in FIG. 4, a receiving portion 27 which is a pedestal of the refractory material 50 may be provided at a place where the refractory material 50 is stacked and becomes an installation surface. That is, the refractory material 50 may be placed on the receiving portion 27. In this case, the receiving portion 27 is supported by, for example, being welded to the upper end of the seal fin 23 on the lower side in the axial direction forming the exhaust gas communication portion 25 (see FIG. 2).

Hereinafter, some embodiments relating to the structure of the refractory material 50 itself will be described with reference to FIGS. 5 to 7. FIG. 5 is a view of the CC'cross section in FIG. 4 viewed from directly above. FIG. 6 is a perspective view of the refractory material 50 according to some embodiments. FIG. 7 is a diagram showing a modified example of the refractory material 50 according to some embodiments.

In some embodiments, as shown in FIG. 5, the refractory 50 has recesses 54 that abut on the outer peripheral surfaces of each of the pair of tubes 21 (21A, 21C) at both ends of the refractory 50. In the embodiment illustrated in FIG. 4, the recess 54 has an arc shape so as to abut on a part of the outer peripheral surface of each of the pair of tubes 21 (21A, 21C). Then, the refractory material 50 is stacked so that the arc-shaped recess 54 and a part of the outer peripheral surface of the tubes 21A and 21C are in contact with each other, so that the refractory material 50 is fitted between the pair of adjacent tubes 21A and 21C. It has been.

According to the present embodiment, the stacked refractories 50 come into contact with the outer peripheral surface of the tube 21 at the recesses 54 at both ends thereof, so that the refractory 50 is more difficult to fall off from between the tubes 21. This makes it possible to avoid damage to the boiler 100 that may occur due to the fall of the refractory material 50.

In some embodiments, as shown in FIGS. 4-6, the refractory 50 is a pair of adjacent first and second portions 51 and second portions 52 that are divided along the axial direction of the tube 21. It includes a first portion 51 that abuts the tube 21C on one side of the tube and a second portion 52 that abuts the tube 21A on the other side of the pair of adjacent tubes. Then, the first division surface 61 is formed on the first portion 51, and the second division surface 62 that abuts on the first division surface 61 is formed on the second portion 52.

According to the present embodiment, when the refractory materials 50 are stacked between the pair of adjacent tubes 21, for example, the first portion 51 is installed so as to be in contact with the tube 21C on one side, and then the first portion 51 is installed. The second portion 52 can be installed so as to be in contact with the tube 21A on the other side from above. That is, if the refractory material 50 is shaped so as to be fitted between the tubes 21 without a gap, it may be difficult to install the refractory material 50 between the tubes 21 and the tubes 21 unless the refractory material 50 can be divided. Therefore, when the shape as in the present embodiment is adopted, the first portion 51 and the second portion 52 can be installed in order at the height position where the refractory materials 50 are desired to be stacked. Therefore, the refractory materials 50 can be easily stacked and removed between the pair of adjacent tubes 21.

In some embodiments, as shown in FIGS. 4 and 6, the first split plane 51 extends in a direction in which at least a portion of the first split plane 51 intersects the axial direction of the tube 21. The second divided surface 62 has one tapered surface 71, and the second divided surface 62 is a second tapered surface 72 extending in a direction in which at least a part of the second divided surface 62 intersects the axial direction of the tube 21. It has a second tapered surface 72 that abuts on one tapered surface 71. In the embodiment illustrated in FIGS. 4 and 6, all of the first divided surface 61 and the second divided surface 62 have the first tapered surface 71 and the second tapered surface 72, but the present embodiment is not limited to this. Instead, a part of the first divided surface 61 and the second divided surface 62 may have a tapered surface. Further, a part of the first division surface 61 and the second division surface 62 may have a plurality of tapered surfaces.

According to the present embodiment, on the first tapered surface 71 and the second tapered surface 72, a pressing force f acting downward in the vertical direction is generated from the second portion 52 to the first portion 51. As a result, the refractory material 50 can be stacked between the pair of tubes 21 in a state where the first portion 51 and the second portion 52 are in close contact with each other. On the other hand, due to the pressing force f generated on the first tapered surface 71 and the second tapered surface 72, each recess 54 of the refractory 54 and each pair of tubes 21 abutting on each recess 54 (21A, 21C in FIG. 5). The refractory material 50 can be firmly fixed between the pair of adjacent tubes 21. Therefore, the rattling of the stacked refractories 50 can be suppressed by a simple configuration.

In some embodiments, as shown in FIGS. 5 and 6, the first division surface 61 has a convex portion 56 projecting toward the second division surface 62, and the second division surface 62 has a convex portion. It has a recess 58 capable of accepting 56. In the embodiment illustrated in FIGS. 5 and 6, the concave portion 58 and the convex portion 56 are continuously formed from the upper surface 64 to the lower surface 65 of the refractory material 50 along the axial direction, but this embodiment is to this. Not limited to this, the concave portion 58 and the convex portion 56 may be provided in a part in the axial direction, or a plurality of concave portions 58 and the convex portion 56 may be provided on the first division surface 61 and the second division surface 62. You may. Further, the first division surface 61 may have a concave portion 58, and the second division surface 62 may have a convex portion.

According to such an embodiment, the first portion 51 and the second portion 52 can be installed so that the convex portion 56 of the first division surface 61 is fitted into the concave portion 58 of the second division surface 62. Therefore, it is possible to suppress the displacement and separation between the first portion 51 and the second portion 52, and make it difficult for the stacked refractories 50 to fall out from between the tubes 21. This makes it possible to effectively avoid damage to the boiler 100 that may occur due to the fall of the refractory material 50.

In one embodiment, as shown in FIG. 7, recesses 68 and protrusions 66 may be provided on the upper surface 64 and the lower surface 65 of the refractory material 50. In the embodiment illustrated in FIG. 7, a convex portion 66 is provided on the upper surface 64 of the first portion 51 and the second portion, respectively, and a concave portion 68 is provided on the lower surface 65 of the first portion and the second portion, respectively. In this case, when the refractory materials 50 are stacked up and down, the convex portion 66 of the upper surface 64 engages with the concave portion 68 of the lower surface 65 of the refractory material 50 stacked on top. According to the present embodiment, even when a plurality of refractories 50 are stacked, the upper and lower refractories 50 are further fixed to each other, so that the refractory 50 can be effectively suppressed from falling off. Although not shown, a concave portion 68 may be provided on the upper surface 64 and a convex portion 66 may be provided on the lower surface 65.
According to such an embodiment, workability when stacking the refractory materials 50 in a plurality of stages is improved, and deviation and separation between the refractory materials 50 stacked in the vertical direction are suppressed, and the stacked refractory materials 50 are tubed. It can be made difficult to drop out from between 21.

FIG. 8 is a flow chart for explaining a steam temperature method in the boiler 100 according to some embodiments.
Some embodiments of the present invention are the steam temperature adjusting method in the boiler 100 described above, wherein the temperature measuring step S3 for measuring the temperature of the steam superheated by the heat exchanger 5 is shown in FIG. Bypass flow path based on the difference calculation step S4 for calculating the difference ΔT between the measured steam temperature Tm measured in the temperature measurement step S3 and the predetermined planned temperature Tp, and the difference ΔT calculated in the difference calculation step S4. A fireproof material number adjusting step S7 for adjusting the number of at least one fireproof material 50 stacked so as to close the flow path cross section of 40 is provided.

In the embodiment shown in FIG. 8, first, the cross section of the flow path is completely closed with the refractory material 50 (S1), and the operation of the boiler 100 is started (S2). Then, in the temperature measurement step S3 described above, the temperature of the steam superheated by the heat exchanger 5 is measured, and in the difference calculation step S4 described above, the difference ΔT (= Tm-Tp) between the measured temperature Tm and the planned temperature Tp is measured. ) Is calculated. Then, after the operation of the boiler 100 is stopped (S5), when the magnitude of the difference ΔT is equal to or larger than the predetermined value Tth (Yes in S6), the cross section of the flow path is closed in the above-mentioned refractory number adjustment step S7. Adjust the number of at least one refractory 50 stacked in the. On the other hand, when the magnitude (absolute value) of the difference ΔT is less than the predetermined value Tth (No in S6), the number of refractories 50 is not adjusted (S8). Then, after S7 and S8 are completed, the operation of the boiler 100 is started again (S2). In the above-described embodiment, the difference calculation step S4 may be executed after the operation of the boiler 100 is stopped.

As described above, in the boiler 100 according to some embodiments of the present invention, when it is desired to raise the steam temperature, a large amount of exhaust gas is exchanged by stacking refractories 50 and blocking the cross section of the bypass flow path 40. It can be passed through the vessel 5. On the other hand, when it is desired to lower the steam temperature, the flow of exhaust gas toward the bypass flow path 40 is generated by removing the stacked refractory materials 50, and the flow rate of the exhaust gas passing through the heat exchanger 5 can be reduced.
Therefore, according to the above-described embodiment, when the difference between the measured temperature Tm and the planned temperature Tp is larger than a predetermined value, for example, when the measured temperature Tm> the planned temperature Tp, the accumulated fireproof material 50 is removed. When the measured temperature Tm <planned temperature Tp, the measured temperature Tm can be brought closer to the planned temperature Tp by stacking the refractory materials 50 and closing the flow path cross section of the bypass flow path 40.

In some embodiments, in the above-mentioned refractory number adjustment step S7, the number of refractories 50 to be adjusted according to the magnitude of the difference ΔT between the measured difference temperature Tm and the planned temperature Tp is set in advance. The number of refractories 50 may be adjusted based on a preset number. For example, if the magnitude of the difference ΔT is divided into a plurality of levels such as A level, B level, and C level from the larger one, and the number of refractories 50 to be adjusted corresponding to each of the plurality of levels is set. good.

Further, in some embodiments, in the above-mentioned refractory number adjustment step S7, the map M () showing the relationship between the closed rate (%) of the cross section of the flow path and the difference ΔT between the measured difference temperature Tm and the planned temperature Tp. The number of refractories 50 to be adjusted may be determined based on (see FIG. 9). Further, if the relationship between the block rate (%) of the cross section of the flow path and the refractories 50 to be stacked is known, the number of refractories 50 to be stacked may be set on the horizontal axis of the map M. Such a map M may be created in advance before the start of operation of the boiler 100.

According to such an embodiment, the number of refractories 50 can be easily adjusted based on the calculated difference ΔT.

Further, in some embodiments, after the number of refractories 50 is adjusted in the above-mentioned refractory number adjustment step S7, the operation of the boiler 100 is started again, and in the above-mentioned difference calculation step S4. If the calculated difference ΔT is still large (for example, when ΔT ≧ Tth), the map M described above may be modified based on the result.

According to such an embodiment, by modifying the map M based on the actual operation result, it is possible to improve the accuracy in controlling the steam temperature based on the map M.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and includes a modification of the above-mentioned embodiment and a combination of these embodiments as appropriate. For example, each embodiment has been described based on a circulating boiler equipped with a steam drum 7 (see FIG. 1) and circulating boiler water via steam lines 9 and 11, but the present invention is not limited thereto. .. For example, it can be applied to a once-through boiler or the like which does not have a steam drum 7 and generates steam without circulating boiler water.

In the present specification, an expression representing a relative or absolute arrangement such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial". Strictly represents not only such an arrangement, but also a tolerance or a state of relative displacement at an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
Further, in the present specification, the expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also within a range in which the same effect can be obtained. , The shape including the uneven portion, the chamfered portion, etc. shall also be represented.
Further, in the present specification, the expression "comprising", "including", or "having" one component is not an exclusive expression excluding the existence of another component.

3 Fireplace wall 5 Heat exchanger 7 Steam drum 9,11 Steam line 10 Fireplace 13 Overheat reducer 21 Tube 23 Seal fin 25 Exhaust gas communication part 27 Receiving part 30 Exhaust gas flow path 31 Branch part 33 Conflue part 35 Flue 40 Bypass flow path 41 Bypass flue 50 Fireproof 51 First part 52 Second part 54 Concave 56 Convex 58 Concave 61 First division surface 62 Second division surface 64 Top surface 65 Bottom surface 71 First taper surface 72 Second taper surface 100 Boiler F Fuel W Water S Steam G Exhaust gas f Pushing force M Map

Claims (5)

The flue that forms the exhaust gas flow path through which the exhaust gas discharged from the furnace flows,
A heat exchanger provided in the exhaust gas flow path for overheating steam,
A bypass flue forming a bypass flow path that branches from the upstream side of the heat exchanger in the exhaust gas flow path and joins the downstream side of the heat exchanger.
With at least one refractory material stacked so as to block at least a part of the cross section of the bypass flow path .
Equipped with
The flue contains a plurality of tubes extending along the vertical direction.
The refractory material is fitted between a pair of tubes adjacent to each other in a direction intersecting the flow direction of the exhaust gas in the bypass flow path at a branch point of the bypass flow path from the exhaust gas flow path.
The refractory has recesses at both ends of the refractory that abut on the outer peripheral surfaces of each of the pair of tubes.
The refractory is a first portion and a second portion that are divided along the axial direction of the tube, the first portion that abuts on one of the adjacent pair of tubes, and the adjacent portion. Includes a second portion of the pair of tubes that contacts the other tube.
A first partition plane is formed on the first portion.
A second division surface that abuts on the first division surface is formed on the second portion.
The first partition surface has a first tapered surface extending in a direction in which at least a part of the first partition surface intersects the axial direction of the tube.
The second divided surface is a second tapered surface in which at least a part of the second divided surface extends in a direction intersecting the axial direction of the tube, and is a second tapered surface that abuts on the first tapered surface. Has a tapered surface
boiler. The first partition plane has a convex portion protruding toward the second partition plane.
The boiler according to claim 1 , wherein the second dividing surface has a concave portion capable of accepting the convex portion. The boiler according to claim 1 or 2 , wherein the refractory material includes bricks. The boiler according to any one of claims 1 to 3 , wherein the fuel containing biomass is burned in the furnace. The method for adjusting the steam temperature in the boiler according to any one of claims 1 to 4 .
A temperature measurement step for measuring the temperature of steam superheated by the heat exchanger, and
A difference calculation step for calculating the difference between the measured temperature of the steam measured in the temperature measurement step and a predetermined planned temperature, and a difference calculation step.
Based on the difference calculated in the difference calculation step, the refractory number adjustment step for adjusting the number of the at least one refractory material stacked so as to block the flow path cross section of the bypass flow path, and the refractory number adjustment step.
A steam temperature adjustment method.

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