WO2019107421A1

WO2019107421A1 - Fluidized bed furnace

Info

Publication number: WO2019107421A1
Application number: PCT/JP2018/043805
Authority: WO
Inventors: 祐司小川; 五十嵐　実; 前川　勇; 敬哲清水; 貞行武藤; 元清瀧; 康二福本; 隆平山田; 利紀村岡; 熊田　憲彦; 貴大山口
Original assignee: 川崎重工業株式会社
Priority date: 2017-11-29
Filing date: 2018-11-28
Publication date: 2019-06-06
Also published as: BR112020010593A2; CN111630319B; JP2019100574A; JP7010676B2; CN111630319A

Abstract

This fluidized bed furnace is provided with: a fluid medium layer; a fluidizing gas supply device which supplies fluidizing gas from the bottom portion of the fluid medium layer; and a plurality of parallel partition walls partitioning the fluid medium layer into three cells. The partition walls include a first partition wall which serves as a partition between a first cell and a second cell so as to allow communication between the cells on the lower side, and a second partition wall which has a lower-end height level lower than that of the first partition wall and which allows communication between a third cell and the second cell on the upper and lower sides. The fluidizing gas supply device has a plurality of air diffusion pipes which are provided, at the respective cell bottom portions of the first to third cells and below the lower ends of the partition walls, in parallel with the partition walls so as not to overlap the partition walls in a plan view.

Description

Fluidized bed furnace

The present invention relates to the configuration of an internal circulation type fluidized bed furnace.

BACKGROUND Conventionally, a fluidized bed furnace is known in which a fluidized bed is formed in which a fluidized medium filled in the lower part of the furnace is made to flow with a flowing gas blown from a furnace bottom. The fluidized bed furnace has an internal circulation system and an external circulation system. In the internal circulation system, the fluidized bed is divided into a combustion chamber and a heat recovery chamber, and the fluid medium is circulated and flowed between these two chambers. , Combustion and heat recovery are performed in the fluidized bed. An internal circulation type fluidized bed furnace of this kind is disclosed, for example, in Patent Document 1.

In the fluidized bed furnace described in Patent Document 1, the fluidized bed is divided into three cells by the first partition and the second partition, and the flowable gas whose flow rate is adjusted independently below or under each cell is A supply air box or air diffuser is provided. In the first cell, fuel (combustion target) is supplied to burn the fuel, and in the third cell, a heat transfer pipe is provided to perform heat recovery. The first cell and the second cell are divided by the first partition so that the lower side communicates with each other, and the second cell and the third cell are divided by the second partition such that the upper side and the lower side communicate with each other. The fluidizing medium moves from the lower part of the first cell to the third cell across the second partition via the second cell and circulates from the lower part of the third cell to the second cell and the first cell by the flowable gas .

JP 2001-241626 A

Generally, in an internal circulation type fluidized bed furnace, a gas distribution plate is provided at the furnace bottom with a wind box at the bottom and a large number of nozzles are formed at the top of the wind box, and the gas in the wind box is a gas dispersion plate It is configured to blow out into the furnace bottom or into the fluidized bed via As described in Patent Document 1, instead of the air box, a configuration in which the fluidizing gas is supplied by a diffuser is also proposed, but a specific aspect is not shown.

The inventors of the present application are examining the supply of gas for fluidization using a diffusion tube in an internal circulation type fluidized bed furnace. In the gas dispersion plate, the nozzles can be appropriately dispersed and disposed on the furnace plane, so that the flowable gas is uniformly dispersed on the furnace plane. However, since it is difficult to distribute the air outlets in the furnace plane in the case of a straight-line aeration tube, it is difficult to form a circulating flow of the fluid medium by supplying the gas for fluidization by means of the aeration tube. It is necessary to determine the layout of the aeration tube etc. in consideration of

Therefore, a fluidized bed furnace according to one aspect of the present invention is
A fluid medium layer comprising a fluid medium,
A flowable gas supply device for supplying a flowable gas for flowing the flowable medium from the bottom of the flowable medium bed;
A plurality of parallel partition walls for dividing the fluidized medium layer into a first cell, a second cell, and a heat transfer pipe which are provided for the combustion of fuel to be subjected to heat recovery, the first cell being a first cell And a second partition wall for communicating the lower side with the second cell, and a height level of a lower end of the first partition wall is lower than that of the first partition wall, and the third cell and the second cell are upper side And a partition wall including a second partition wall communicating with the lower side,
The flow gas supply device is the bottom of each of the first to third cells, and is lower than the lower end of the partition wall, so that the partition wall does not overlap in plan view with the partition wall in plan view And a plurality of aeration tubes arranged in parallel with

According to the above-described fluidized bed furnace, the flowable gas blown out from the aeration pipe is well dispersed in each cell without blocking the flow of the flowable medium. As a result, the flow medium in each cell is urged to flow according to the flow direction of the cell. Therefore, in the internal circulation type fluidized bed furnace, if the above-described features of the fluidized bed furnace are applied, the flow medium can be favorably circulated and moved by the supply of the flowable gas using the diffusion pipe.

In the fluidized bed furnace described above, in the fluidizing gas supply apparatus, the superficial velocity of the fluidizing gas of the second cell is larger than the superficial velocity of the fluidizing gas of the first cell, and the first gas The flowing gas may be blown out from the aeration tube such that the superficial velocity of the flow gas in the cell is higher than the superficial velocity of the flow gas in the third cell.

Thereby, the fluid medium circulates from the first cell to the third cell through the second cell, and further, from the third cell to the first cell.

In the above fluidized bed furnace, the aeration pipe may be provided so as to be insertable into and removable from the furnace body.

As a result, due to thermal fatigue, friction, etc., it is possible to easily replace the aeration tube having a high replacement frequency as compared with other elements of the furnace.

In the fluidized bed furnace described above, the aeration pipes may be connected by a header for each cell, and a flow gas supply pipe provided with a flow rate adjusting means may be connected to each header.

This makes it easy to adjust the flow rate of the flowable gas supplied to the air diffusion pipe for each cell.

In the fluidized bed furnace described above, when the fluidizing gas of a predetermined standard flow rate is supplied to each of the aeration tubes, the superficial velocity of the fluidizing gas of the second cell is the fluid velocity of the first cell It arranges to each cell so that the superficial velocity of the flow gas of the first cell is larger than the superficial velocity of the flow gas and the superficial velocity of the flow gas of the third cell is larger The number of the aeration tubes to be carried out may be determined.

Thereby, even if the flow rate of the flowable gas supplied to each aeration tube is uniform, the superficial velocity of the flowable gas in the first to third cells has a predetermined correlation that causes the flow medium to circulate. Therefore, it becomes easy to adjust the flow rate of the fluidizing gas supplied to each cell.

According to the present invention, in the internal circulation type fluidized bed furnace, it is possible to realize the supply of the flowable gas using the diffusion pipe.

FIG. 1 is a block diagram showing a schematic configuration of a combustion system including a fluidized bed furnace according to an embodiment of the present invention. FIG. 2 is a view showing a schematic configuration of a fluidized bed furnace according to an embodiment of the present invention. FIG. 3 is an enlarged view of the fluidized bed portion of the fluidized bed furnace. FIG. 4 is a plan view of the furnace bottom showing the layout of the aeration tube.

[Composition of combustion system 100]
First, the configuration of a combustion system 100 including a fluidized bed furnace 1 according to an embodiment of the present invention will be described. The combustion system 100 shown in FIG. 1 is a system that burns fuel (combustion target) such as coal, biomass, RDF, municipal waste, and industrial waste, and recovers its exhaust heat.

The combustion system 100 comprises a fluidized bed furnace 1 for burning fuel. The flue gas system 3 of the fluidized bed furnace 1 is provided with a heat exchange device 31, a cyclone dust collector 32, a bag filter 33, and an induction blower 34 which is an induction fan. Exhaust heat from the fluidized bed furnace 1 is recovered by the heat exchanger 31 and dust is separated by the cyclone type dust collector 32 and the bag filter 33, and a part thereof is discharged out of the system through a chimney not shown by the induction blower 34. Be done.

An exhaust gas recirculation system 4 is connected to the downstream side of the bag filter 33 of the combustion exhaust gas system 3. A gas recirculation blower 40 is provided in the exhaust gas recirculation system 4, and a part of the combustion exhaust gas of the combustion exhaust gas system 3 is returned to the fluidized bed furnace 1 by the gas recirculation blower 40. The flue gas returned to the fluidized bed furnace 1 by the flue gas recirculation system 4 is used as a fluidizing gas (primary combustion gas), a secondary combustion gas, and a tertiary combustion gas.

[Configuration of fluidized bed furnace 1]
Next, the configuration of the fluidized bed furnace 1 according to an embodiment of the present invention will be described. The fluidized bed furnace 1 shown in FIG. 2 is an operation control device for controlling the operation of the fluidized bed furnace 1 and a furnace main body 10 provided with a combustion chamber consisting of a fluidized bed portion 11 at the lower part of the furnace and a freeboard portion 12 above it. And a fluidized bed monitoring device 9. At the lower portion of the freeboard portion 12, there is a throttle portion 13 in which the gas passage cross-sectional area is narrowed as compared with the remaining portion of the combustion chamber. In the freeboard portion 12, the combustion gas flows upward from the bottom, and in the flue connected to the upper portion of the freeboard portion 12, a heat transfer pipe constituting the heat exchange device 31 is installed.

FIG. 3 is an enlarged view of the fluidized bed portion 11. As shown in FIG. 2 and FIG. 3, the fluidizing bed 11 is provided with a fluidizing medium bed 51 filled with a fluidizing medium such as silica sand, and a fluidizing gas supply apparatus for supplying fluidizing gas from the bottom to the fluidizing medium bed 51. An internal circulating fluidized bed is formed by 52 and

partition walls

41 and 42 which divide the fluidized medium layer 51 into three

cells

61, 62 and 63.

The first partition wall 41 divides the lower portion of the furnace main body 10 including the fluidized bed portion 11 into a combustion area 53 and a heat recovery area 54. The second partition wall 42 is provided close to the first partition wall 41 and in parallel with the first partition wall 41 in the heat recovery region 54. The fluidized bed portion 11 is formed by the

partition walls

41 and 42 between the first side wall 10 a of the furnace main body 10 and the first partition wall 41, the “combustion cell 61”, the first partition wall 41 and the second Three cells of “circulating cell 62” formed between partition wall 42 and “heat collecting cell 63” formed between second partition wall 42 and second side wall 10 b of furnace main body 10 It is divided. The heat collection cell 63 is provided with a heat transfer pipe 64 such as a superheater pipe or an evaporator pipe. Heat recovery is performed by the heat medium passing through the heat transfer tube 64.

Above the combustion area 53, a combustion chamber extending linearly in the vertical direction is formed. On the other hand, above the heat recovery area 54, a ceiling wall 43 closing the upper portion of the heat recovery area 54 is provided. The upper end of the first partition wall 41 is close to the ceiling wall 43, and an upper communication port serving as an unburned gas supply port 68 is formed between the upper end of the first partition wall 41 and the ceiling wall 43. The lower end of the first partition wall 41 is higher than the lower end of the second partition wall 42, whereby a lower communication port 55 through which the fluid medium flows is formed in the lower portion of the first partition wall 41. Further, in the upper and lower portions of the second partition wall 42,

communication ports

56, 57 are formed, which communicate the circulation cell 62 with the heat collecting cell 63 and through which the fluid medium flows.

The flow gas supply device 52 supplies the flow gas whose flow rate is independently adjusted to each of the combustion cell 61, the circulation cell 62, and the heat collection cell 63. At the bottom of each of the combustion cell 61, the circulation cell 62, and the heat collection cell 63, one or a plurality of air diffusers 80 having a large number of blowout ports opened to the side are provided.

The air diffusion pipe 80 is connected by a header for each of the

cells

61, 62, 63, and each header is a flow provided with flow rate adjusting means 81a, 82a, 83a such as a damper (or valve) and

flowmeters

81b, 82b, 83b. The

gas supply pipes

81, 82, 83 are connected. To the flow gas supply pipe 81 connected to the air diffusion pipe 80 disposed at the bottom of the combustion cell 61 and the flow gas supply pipe 82 connected to the air diffusion pipe 80 disposed at the bottom of the circulation cell 62, Air is supplied by the pushing blower 79. Further, an exhaust gas recirculation system 4 is connected to a flow gas supply pipe 83 connected to the air diffusion pipe 80 disposed at the bottom of the heat collection cell 63.

The operation control device 15 detects each flow gas based on detection values of temperature sensors (not shown) for detecting the temperatures of the combustion cells 61 and the heat collection cells 63 in the flow medium layer 51 and the

flowmeters

81b, 82b, 83b, etc. The flow rate adjusting means 81a, 82a, 83a are operated so as to adjust the flow rate of the flowing gas in the

supply pipes

81, 82, 83. From the bottom of the combustion cell 61 and the circulation cell 62, air is blown out as a flow gas, and from the bottom of the heat collection cell 63, combustion exhaust gas is blown out as a flow gas.

Here, the superficial velocity of the flowable gas of the combustion cell 61 is larger than the superficial velocity of the flowable gas of the heat collection cell 63, and the superficial velocity of the flowable gas of the circulation cell 62 is equal to that of the combustion cell 61. The flow rate of the flowable gas is adjusted to be greater than the superficial velocity of the flowable gas and the superficial velocity of the flowable gas of the heat collection cell 63. Thereby, the flow medium of the combustion cell 61 moves to the circulation cell 62 through the lower communication port 55 of the first partition wall 41, and the flow medium of the circulation cell 62 passes through the upper communication port 56 of the second partition wall 42. The flow of the fluid medium occurs such that the fluid medium of the heat collection cell 63 is circulated to the combustion cell 61 and the circulation cell 62 through the lower communication port 57 of the second partition wall 42 after moving to the heat collection cell 63.

In the freeboard portion 12, a fuel inlet 65 is opened immediately above the surface layer portion of the fluidized bed portion 11 at the time of operation and in the first side wall 10a. The fuel inlet 65 is located on the upstream side of the flow of the combustion gas than the throttle portion 13. Fuel is supplied to the fuel inlet 65 by a fuel supply device (not shown). The fuel introduced into the furnace from the fuel inlet 65 falls to the top of the combustion cell 61 of the fluidized bed portion 11.

In the furnace wall on the downstream side of the flow of combustion gas with respect to the fuel inlet 65 and in the furnace wall around the throttle portion 13 in the freeboard portion 12, an unburned gas supply port 68 is opened. From the unburned gas supply port 68, the air is blown out from the aeration pipe 80 disposed in the fluid medium layer 51 of the heat recovery area 54 into the fluid medium layer 51, and after passing through the fluid medium layer 51 The mixture is blown out as a secondary combustion gas. However, in addition to the unburned gas supply port 68, a supply port for blowing out the secondary combustion gas may be provided.

In the freeboard portion 12, a plurality of tertiary combustion gas supply ports 69 are opened in the furnace wall on the downstream side of the flow of the combustion gas than the unburned gas supply port 68. The plurality of tertiary combustion gas supply ports 69 are provided to be dispersed at a plurality of height positions. Further, a temperature sensor 70 is provided on the furnace wall included in the diffusion area of the tertiary air blown out from the tertiary combustion gas supply port 69.

The air content of the tertiary combustion gas is adjusted by mixing the combustion exhaust gas with air. For that purpose, flow control means 88, 89 such as dampers (or valves) are provided in the air supply path to the tertiary combustion gas supply port 69 and the combustion exhaust gas supply path. When the temperature detected by the temperature sensor 70 at a certain point exceeds a predetermined range, the operation control device 15 maintains the flow rate of the tertiary combustion gas at the predetermined flow rate, and supplies the tertiary combustion gas to that point. In order to reduce the air content of the gas, and when the detected temperature is lower than the predetermined range, the flow rate adjusting means 88, 89 so that the air content of the tertiary combustion gas supplied to that point is increased. Adjust the opening of the.

[Operation method of fluidized bed furnace 1]
Here, the operation method of the fluidized bed furnace 1 of the said structure is demonstrated. In the fluidized bed furnace 1, low air ratio combustion is performed in the fluidized bed portion 11. More specifically, while the total air ratio between the fluidized bed portion 11 and the freeboard portion 12 is set to a value larger than 1, the air ratio (ie, the primary air ratio) of the combustion cells 61 of the fluidized bed portion 11 and the freeboard Supply amounts of fluidizing air and secondary combustion gas to the combustion cell 61 so that the air ratio (secondary air ratio) around the fuel inlet 65 of the portion 12 is all less than 1; And / or its air content is adjusted. Preferably, the primary air ratio is lower than the secondary air ratio. For example, when the total air ratio of the fluidized bed portion 11 and the freeboard portion 12 is 1.2, the primary air ratio may be 0.4 and the secondary air ratio may be 0.8.

In the fluidized bed portion 11 with a low oxygen concentration reducing atmosphere, the slow drying and thermal decomposition of the fuel generate combustible pyrolysis gas and pyrolysis residue. Pyrolysis residue and fuel residue are at the bottom of the combustion cell 61, and are provided at the intermediate position between the first side wall 10a and the first partition wall 41 from the outlet 72 of the fluid medium and the incombustible material. It is discharged outside. The pyrolysis gas generated in the fluidized bed portion 11 is burned with the secondary combustion gas, the unburned portion in the combustion gas is completely burned with the tertiary combustion gas, and the combustion exhaust gas is discharged to the combustion exhaust gas system 3 Ru.

[Flowing gas supply device 52]
Here, the configuration of the fluidizing gas supply device 52 will be described in detail. FIG. 4 is a plan view of the furnace bottom showing the layout of the air diffusion tube 80.

As shown in FIG. 4, in the fluidized bed portion 11, at least one air diffusion pipe 80 is provided in each of the

cells

61, 62, 63. The aeration tube 80 is, for example, a circular tube in which a plurality of laterally directed air outlets are uniformly distributed in the extending direction.

The first partition wall 41 and the second partition wall 42 are disposed in parallel, and the in-plane direction of the

partition walls

41 and 42 and the extension direction of the respective diffusers 80 are parallel. Between the first side wall 10 a and the first partition wall 41, between the first partition wall 41 and the second partition wall 42, the air diffusion tube 80 does not overlap with the

partition walls

41 and 42 in a plan view. It is arrange | positioned between the partition wall 42 and the 2nd side wall 10b, respectively.

Each aeration tube 80 is disposed below the lower ends of the first partition wall 41 and the second partition wall 42. The distance between the lower end of the second partition wall 42 having the lower height level of the lower end of the two

partition walls

41 and 42 and the pipe center of the air diffusion pipe 80 is in the range of 200 mm to 300 mm. Thus, if the distance between the lower partition wall 42 having a lower height level and the center of the aeration tube 80 is within the above range, the fluid medium moves across the cell well. Have been confirmed by

Each aeration tube 80 is inserted in the furnace wall of the furnace main body 10 so as to be insertable and removable parallel to the extending direction of the aeration tube 80. At the time of maintenance, the air diffusion tubes 80 can be individually attached to and detached from the furnace body 10.

The aeration tube 80 is connected by a header for each of the

cells

61, 62, 63, and the superficial velocity of the fluidizing gas in each of the

cells

61, 62, 63 has a predetermined correlation that causes the fluidizing medium to circulate. As described above, the flow rate of the flowable gas supplied to the air diffusion pipe 80 is adjusted for each of the

cells

61, 62, 63. Here, “predetermined correlation” means that the flow velocity of the flow cells in each of the

cells

61, 62, 63 is higher than the flow velocity of the flow medium. The superficial velocity is larger than the superficial velocity of the flowable gas of the combustion cell 61, and the superficial velocity of the flowable gas of the combustion cell 61 is larger than the superficial velocity of the flowable gas of the heat collection cell 63 It means the relationship of the superficial velocity of the gas for fluidization of the cell.

In addition, when all the gas diffusion tubes 80 are supplied with the flow gas for a predetermined standard flow rate, the superficial velocity of the flow gas for each cell becomes a predetermined correlation that causes the flow medium to circulate. The number of air diffusers 80 disposed in each

cell

61, 62, 63 is determined. Here, the number of outlets may be different for each of the aeration tubes 80.

As described above, in the fluidized bed furnace 1 according to the present embodiment, the fluidized medium bed 51 made of the fluidized medium and the flowing gas supply that supplies the flowing gas that causes the fluidized medium to flow from the bottom of the fluidized medium bed 51 A device 52, a combustion cell 61 (first cell) in which the fuel is combusted in the fluidized medium layer 51, a circulation cell 62 (second cell), and a heat collection cell in which heat transfer is performed are provided. A plurality of

parallel partition walls

41 and 42 which divide into 63 (third cells) are provided. The

partition walls

41 and 42 have lower height levels at the lower end than the first partition wall 41 and the first partition wall 41 that divide the combustion cell 61 and the circulation cell 62 so as to communicate with the lower side thereof; It includes a second partition wall 42 communicating the cell 63 with the circulation cell 62 on the upper side and the lower side. And the gas supply apparatus 52 for flow is a bottom view of each

cell

61,62,63, and it is a plan view so that it may not overlap with the

partition walls

41 and 42 in plan view below below the lower end of the

partition walls

41 and 42. , And a plurality of aeration tubes 80 disposed in parallel with the

partition walls

41 and 42. In the plan view, the fact that the

partition walls

41 and 42 and the plurality of diffusers 80 are arranged in parallel means that the direction in which the surfaces of the

partition walls

41 and 42 extend and the plurality of diffusers 80 in the plan view. It means that the stretching direction is parallel.

In the fluidized bed furnace 1 configured as described above, the flowable gas blown out from the aeration pipe 80 is well dispersed in each of the

cells

61, 62, 63 without obstructing the flow of the flowable medium, and becomes a flowable medium in each cell, Flow is promoted according to the flow direction of the cell.

In the fluidized bed furnace 1, the fluidizing gas supply device 52 has the superficial velocity of the fluidizing gas in the circulation cell 62 greater than the superficial velocity of the fluidizing gas in the combustion cell 61, and The gas for flow is blown out from the diffuser tube 80 so that the velocity of the gas for flow becomes higher than the velocity of the gas for flow of the heat collecting cell 63.

As described above, the inventors of the present invention have said that the flow medium circulates and moves favorably from the combustion cell 61 to the heat collecting cell 63 through the circulation cell 62 and further from the heat collecting cell 63 to the combustion cell 61 by blowing out the gas for flow. Has been confirmed by. Therefore, if the feature of the fluidized bed furnace 1 according to the present embodiment is applied to the internal circulation type fluidized bed furnace, the fluidized bed in which the flowing medium circulates and moves favorably by the supply of the flowing gas using the diffusion pipe 80. Can be realized.

And if supply of the gas for fluidization using diffusion pipe 80 is realized in fluidized bed furnace 1 of internal circulation type as mentioned above, the separation distance between diffusion pipe 80 and heat transfer pipe 64 in heat collection cell 63 It can be shortened in comparison, which makes it possible to reduce the bed height of the fluidized medium bed 51. If the bed height of the flowing medium layer 51 can be reduced, the driving power of the

blowers

40 and 79 for pumping the flowing gas to the aeration tube 80 can be reduced. In addition, when using the conventional gas distribution board and a wind box, in order to maintain the heat transfer tube 64, it was necessary to secure a working space between the gas distribution plate and the heat transfer pipe 64, but this embodiment In the fluidized bed furnace 1 according to the present invention, even if a working space is not provided between the heat transfer pipe 64 and the aeration pipe 80, work is performed on the heat transmission pipe 64 from the gap between the aeration pipes 80. It is possible to remove the heat transfer pipe 64 from the main body 10 and perform work on the heat transfer pipe 64.

Further, in the fluidized bed furnace 1 according to the present embodiment, the air diffusion pipe 80 is provided so as to be insertable into and removable from the furnace main body 10.

As described above, since the aeration tube 80 can be inserted into and removed from the furnace body 10, the aeration tube 80 having a high replacement frequency can be easily replaced as compared with other elements of the furnace due to thermal fatigue, friction, etc. .

Further, in the fluidized bed furnace 1 according to the present embodiment, the aeration pipe 80 is connected by a header for each of the

cells

61, 62, 63, and the flow is provided with flow rate adjusting means 81a, 82a, 83a in each header. The

gas supply pipes

81, 82, 83 are connected.

This makes it easy to adjust the flow rate of the fluidizing gas supplied to the air diffusion pipe 80 for each of the

cells

61, 62, 63.

Further, in the fluidized bed furnace 1 according to the present embodiment, when the flow gas for flow having a predetermined standard flow rate is supplied to each of the aeration pipes 80, the superficial velocity of the flow gas for the circulation cell 62 is that of the combustion cell 61. Each

cell

61, 62, and so that the superficial velocity of the fluidizing gas of the combustion cell 61 is larger than the superficial velocity of the fluidizing gas and greater than the superficial velocity of the fluidizing gas of the heat collecting cell 63. The number of aeration tubes 80 disposed at 63 is determined.

Thereby, even if the flow rate of the flowable gas supplied to each aeration tube 80 is made uniform, for example, the predetermined velocity of the flowable gas in each

cell

61, 62, 63 causes the flow medium to circulate. Because of the relationship, it becomes easy to adjust the flow rate of the fluidizing gas supplied to each of the

cells

61, 62, 63 in operation.

Although the preferred embodiments of the present invention have been described above, modifications of the specific structure and / or function details of the above embodiments may be included in the present invention without departing from the spirit of the present invention. .

1: fluidized bed furnace 3: combustion exhaust gas system 4: exhaust gas recirculation system 10: furnace main body 10 a: first side wall 10 b: second side wall 11: fluidized bed 12: free board 13: throttle 15: operation control device 31 : Heat exchange device 32: Cyclone type dust collector 33: Bag filter 34: Induction blower 40: Gas recirculation blower 41: First partition wall 42: Second partition wall 43: Ceiling wall 51: Fluid bed 52: Flowing gas supply device 53: combustion area 54:

heat recovery area

55, 56, 57: communication port 61: combustion cell (first cell)
62: Circulating cell (second cell)
63: Heat collection cell (third cell)
64: heat transfer pipe 65: fuel inlet 68: unburned gas supply port 69: third combustion gas supply port 70: temperature sensor 72: outlet port 79: push-in blower 80:

air diffuser

81, 82, 83: gas supply for

flow Piping

81a, 82a, 83a: Flow adjustment means 81b, 82b, 83b: Flow meter 88, 89: Flow adjustment means 9 Fluid bed monitoring device 91: Pressure sensor 92: Calculation unit 93: Monitoring unit 100: Combustion system

Claims

A fluid medium layer comprising a fluid medium,
A flowable gas supply device for supplying a flowable gas for flowing the flowable medium from the bottom of the flowable medium bed;
A plurality of parallel partition walls for dividing the fluidized medium layer into a first cell, a second cell, and a heat transfer pipe which are provided for the combustion of fuel to be subjected to heat recovery, the first cell being a first cell And a second partition wall for communicating the lower side with the second cell, and a height level of a lower end of the first partition wall is lower than that of the first partition wall, and the third cell and the second cell are upper side And a partition wall including a second partition wall communicating with the lower side,
The flow gas supply device is the bottom of each of the first to third cells, and is lower than the lower end of the partition wall, so that the partition wall does not overlap in plan view with the partition wall in plan view With multiple aeration tubes arranged parallel to the
Fluidized bed furnace.
In the gas supply apparatus for flow, the superficial velocity of the flowable gas of the second cell is larger than the superficial velocity of the flowable gas of the first cell, and the flowable gas of the first cell Blowing the flowable gas from the aeration tube such that the superficial velocity of the third cell is greater than the superficial velocity of the flowable gas of the third cell;
A fluidized bed furnace according to claim 1.
The aeration tube is provided so as to be insertable into and removable from the furnace body.
A fluidized bed furnace according to claim 1 or 2.
The aeration pipes are connected by a header for each cell, and a flow gas supply pipe provided with flow rate adjusting means is connected to each header.
A fluidized bed furnace according to any one of the preceding claims.
When the fluidizing gas of a predetermined standard flow rate is supplied to each of the diffusers, the superficial velocity of the fluidizing gas of the second cell is higher than the superficial velocity of the fluidizing gas of the first cell And the number of the diffusers disposed in each cell such that the superficial velocity of the fluidizing gas of the first cell is greater than the superficial velocity of the fluidizing gas of the third cell Is defined,
A fluidized bed furnace according to any one of the preceding claims.