Combustion equipment equipped with a supply unit for low-density combustion materials

Abstract

To provide a combustion facility comprising a supply part for appropriately charging a low specific gravity combustion body into a fluidized bed to combust it.SOLUTION: A combustion facility 1 combusts a combustion body in a fluidized bed 22 formed in an interior, and comprises a fluidized bed furnace 2 in which a flowing air supply part for injecting flowing air into the fluidized bed 22 is provided in a lower part, and a combustion body charging part 29 for supplying the combustion body to the fluidized bed 22 is provided in an upper part. The fluidized bed furnace 2 comprises a low specific gravity combustion body supply part 8 for supplying a low specific gravity combustion body 200 having a lower specific gravity than that of the combustion body to the fluidized bed 22, between a combustion body charging port 29a of the combustion body charging part 29 and an upper surface of the fluidized bed 22.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to combustion equipment including a fluidized bed furnace and a supply section for a low specific gravity combustible material.

Background Art

[0002] Conventionally, a fluidized bed furnace is known which forms a fluidized bed inside and burns combustible materials such as waste (e.g., garbage and sludge) and fuel (e.g., biomass fuel and waste plastic fuel) in the fluidized bed. In such a fluidized bed furnace, in order to flow the fluid medium (BM: Bed Material, generally silica sand) constituting the fluidized bed, fluidizing air is ejected from below into the fluidized bed, and the combustible material to be burned in the fluidized bed is supplied from above the fluidized bed and burned in the fluidized bed.

[0003] On the other hand, in recent years, as combustible materials to be burned in the fluidized bed, the demand for the above-mentioned biomass fuel and waste plastic fuel has been increasing in response to the trend of decarbonization of energy supply. Such combustible materials include low specific gravity combustible materials such as sawdust and rice husks in biomass-based fuels and fluff in waste plastic-based fuels.

[0004] For example, as a prior art for burning this type of combustible material, there is one in which a supply pipe for low specific gravity solid waste is inserted into the inside of the fluidized bed, and the low specific gravity solid waste is directly supplied to the furnace bottom side of the fluidized bed and burned (see, for example, Patent Document 1).

[0005] Also, as another prior art, there is one in which high-calorie garbage is selected from the garbage to be burned in the combustion furnace, the high-calorie garbage is introduced into the empty tower section from above, and the remaining garbage is introduced into the empty tower section from below (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

[0007] Incidentally, when low-density combustion materials such as fluff are introduced through the same input as general solid fuels (combustion materials), they may be carried downstream by the combustion gas flow within the furnace and fail to reach the fluidized bed. As a result, maintaining the bed temperature becomes difficult due to the fuel not reaching the fluidized bed, which may prevent stable operation of the fluidized bed furnace. In addition, the combustion of low-density fuel in the upper part of the fluidized bed causes the upper part to become hot, leading to problems such as clinker formation and poor fluidity of the fluidized medium due to clinker fallout. Furthermore, in configurations where heat is recovered in the fluidized bed, this can lead to problems such as a decrease in the amount of heat recovered by the in-bed heat recovery tubes.

[0008] In Patent Document 1, low-density solid incinerators are directly supplied into the fluidized bed from a supply pipe inserted into the bed. However, supplying low-density combustible materials such as fluff directly into the bed requires pushing them in with high-pressure gas. This makes it difficult to control the combustion temperature and other parameters due to the high-pressure gas blown into the fluidized bed.

[0009] Furthermore, in the above-mentioned Patent Document 2, high-calorie waste (combustible material) is introduced from the top of the empty tower section, which can cause it to burn before reaching the fluidized bed, making it difficult to supply fuel to the fluidized bed.

[0010] Therefore, the present invention aims to provide a combustion system equipped with a supply unit that appropriately introduces a low-density combustible material into a fluidized bed for combustion. [Means for solving the problem]

[0011] To achieve the above objective, the combustion equipment equipped with a low-density combustion body supply unit according to the present invention is a combustion equipment that burns a combustion body in a fluidized bed formed inside, comprising a fluidized bed furnace having a fluidized air supply unit at the bottom for injecting fluidized air into the fluidized bed and a combustion body input unit at the top for supplying the combustion body to the fluidized bed, wherein the fluidized bed furnace is equipped with a low-density combustion body supply unit between the input port of the combustion body input unit and the upper surface of the fluidized bed for supplying the low-density combustion body to the fluidized bed.

[0012] This configuration allows low-density combustion material to be supplied to the fluidized bed from a low-density combustion material supply unit located between the inlet of the combustion material input section (such as solid fuel) and the upper surface of the fluidized bed. Therefore, by supplying the low-density combustion material to the fluidized bed from a position close to the fluidized bed, the low-density combustion material can be properly delivered to the fluidized bed and burned. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a combustion system equipped with a low-density combustion material supply unit that can appropriately supply a low-density combustion material to a fluidized bed and stabilize combustion in the fluidized bed. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a schematic diagram showing a first combustion equipment according to the first embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view showing the low-density combustion element supply section of the first combustion equipment shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram showing a second combustion equipment according to a second embodiment of the present invention. [Figure 4] Figure 4 is a schematic diagram showing a third combustion equipment according to the third embodiment of the present invention. [Figure 5] Figure 5 is a schematic diagram showing a modified example of a fluidized bed furnace according to the present invention. [Modes for carrying out the invention]

[0015] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The combustion equipment 1,100,110 according to the following embodiment is merely one example. Therefore, the present invention is not limited to the following embodiments, and additions, deletions, and modifications are possible without departing from the spirit of the invention.

[0016] (First Embodiment) Figure 1 is a schematic diagram showing a first combustion equipment 1 according to the first embodiment. Figure 2 is a cross-sectional view showing a low-density combustion body supply section 8 of the first combustion equipment 1 shown in Figure 1. As shown in Figure 1, the first combustion equipment 1 includes a fluidized bed furnace 2 for burning the combustion body and a boiler 5 for recovering heat from the exhaust gas discharged from the fluidized bed furnace 2. Furthermore, the combustion equipment 1 includes a dust collector 62 connected to the boiler 5 by a first gas duct 61 and a chimney 65 connected to the dust collector 62 by a second gas duct 63. The dust collector 62 is, for example, a bag filter. An induced draft fan 64 is provided in the second gas duct 63. However, the combustion equipment 1 does not necessarily have to include a boiler 5, and the fluidized bed furnace 2 may be connected to the dust collector 62 by the first gas duct 61.

[0017] The fluidized bed furnace 2 of this embodiment has an internal circulation system in which a fluidized bed section 20 is formed inside. Also, the fluidized bed furnace 2 of this embodiment has a dispersion plate system. Above the fluidized bed section 20, a freeboard section 21 for secondary combustion is formed. The fluidized bed section 20 has a fluidized bed 22 formed of a fluid medium 10 such as silica sand. The fluidized bed 22 of this embodiment is partitioned by a first partition wall 23 and a second partition wall 24 into a combustion cell 25 in the central portion, circulation cells 26 formed on both outer sides thereof, and heat absorption cells 27 (in this embodiment, the heat absorption cells 27 in which heat exchangers 28 are arranged, but the heat exchangers 28 may not be arranged) formed on both outer sides thereof. That is, the combustion cell 25 and the heat absorption cell 27 are provided so as to be adjacent to each other with the circulation cell 26 interposed therebetween. The upper end of the first partition wall 23 is located above the fluidized bed 22, and partitions the combustion cell 25 and the circulation cell 26 in a state of being in communication with each other below. The upper end of the second partition wall 24 is located on the upper surface of the fluidized bed 22, and the lower end is located below the first partition wall 23, and partitions the circulation cell 26 and the heat absorption cell 27 in a state of being in communication with each other above and below. In this embodiment, a heat exchanger 28 for generating and / or superheating steam is arranged in the heat absorption cell 27.

[0018] Further, the freeboard section 21 formed upward from the fluidized bed section 20 is provided with a combustion body input section 29 for supplying a combustion body such as solid fuel to the fluidized bed 22. The combustion body input section 29 is provided at an angle such that the combustion body introduced into the fluidized bed furnace 2 from the combustion body input port 29a is introduced into the combustion cell 25 of the fluidized bed 22.

[0019] A fluidizing air supply device 3 is provided at the lower part of the fluidized bed furnace 2. The fluidizing air supply device 3 includes a plurality of air supply holes 30 which are fluidizing air supply parts for ejecting fluidizing air into the fluidized bed 22, a combustion cell air supply device 31, a circulation cell air supply device 32, and a heat recovery cell air supply device 33. The fluidizing air supply device 3 further includes a first fan 34 for supplying air to each of the combustion cell air supply device 31, the circulation cell air supply device 32, and the heat recovery cell air supply device 33. The combustion cell air supply device 31 includes a flow rate adjusting device 31a for adjusting the flow rate of air. Similarly, the circulation cell air supply device 32 includes a flow rate adjusting device 32a, and the heat recovery cell air supply device 33 includes a flow rate adjusting device 33a. By each of the combustion cell air supply device 31, the circulation cell air supply device 32, and the heat recovery cell air supply device 33, the combustion cell air 35, the circulation cell air 36, and the heat recovery cell air 37 are respectively adjusted to appropriate flow rates. The combustion cell air 35 is ejected into the combustion cell 25, the circulation cell air 36 is ejected into the circulation cell 26, and the heat recovery cell air 37 is ejected into the heat recovery cell 27.

[0020] In this fluidizing air supply device 3, the speed of the combustion cell air 35 is greater than the speeds of the circulation cell air 36 and the heat recovery cell air 37. As a result, the superficial velocity of the combustion cell 25 in the fluidized bed 22 becomes greater than the superficial velocities of the circulation cell 26 and the heat recovery cell 27, and a density difference occurs in the fluidizing medium 10. Due to this density difference, the fluidizing medium 10 is caused to flow. Specifically, this fluidizing medium 10 is caused to flow from the combustion cell 25 through the circulation cell 26 to the heat recovery cell 27, and further from the heat recovery cell 27 to the combustion cell 25.

[0021] More specifically, the fluidized medium 10, which has become hot from the combustion of the combustion material in the combustion cell 25 of the fluidized bed 22, flows from the combustion cell 25 through the lower part of the first partition wall 23 to the circulation cell 26, and the fluidized medium 10 in the circulation cell 26 flows through the upper part of the second partition wall 24 to the heat recovery cell 27. Since a heat exchanger 28 is located in the heat recovery cell 27, the heat from the fluidized medium 10 that has flowed into the heat recovery cell 27 is recovered by the heat exchanger 28. On the other hand, the fluidized medium 10 from which heat has been recovered in the heat recovery cell 27 flows from the heat recovery cell 27 through the lower part of the second partition wall 24 and the first partition wall 23 to the combustion cell 25.

[0022] Thus, the fluidized bed 22 is divided into a combustion cell 25, a circulation cell 26, and a heat recovery cell 27 by a first partition wall 23 and a second partition wall 24, and the fluidized medium 10, which has become hot in the combustion cell 25, is circulated as described above, and heat is recovered in the heat recovery cell 27.

[0023] Furthermore, the freeboard section 21 is equipped with a tertiary air supply section 39 that supplies tertiary air for secondary combustion. The tertiary air supply section 39 is located above the combustion body inlet 29a of the combustion body inlet section 29. Tertiary air 42 is supplied to the tertiary air supply section 39 from the second fan 41 via the third supply passage 40. In this figure, multiple second fans 41 are shown to clarify the configuration, but the system is not limited to this example.

[0024] Furthermore, the bottom of the fluidized bed section 20 is a hopper 45 that discharges combustion residues (e.g., ash and metal fragments) together with the fluidized medium 10. The hopper 45 has a discharge port 46 in the center, and the inner surface of the hopper 45 is inclined diagonally downward toward the discharge port 46. The air supply holes 30 are provided in this hopper 45.

[0025] However, the configuration of the fluidized bed furnace 2 is not limited to this and can be changed as appropriate. For example, the fluidized bed furnace 2 may not include a heat recovery cell 27, and the combustion element may be burned throughout the entire interior of the fluidized bed furnace 2.

[0026] In the boiler 5 described above, steam is generated by the exhaust gas discharged from the fluidized bed furnace 2. More specifically, the boiler 5 has a first flue 50 that connects the upper parts of the freeboard section 21 located above the fluidized bed furnace 2 and a second flue 51 that connects the lower parts of the first flue 50 and the first flue 51. Heat exchangers 52 and 53 are arranged in the second flue 51. Heat exchangers may also be arranged in the first flue 50. The steam generated in the boiler 5 is sent to a turbine (not shown) and used for power generation or as a heat source.

[0027] Furthermore, the fluidized bed section 20 is equipped with a low-density combustion material supply section 8 that supplies a low-density combustion material 200, such as fluff, which has a lower specific gravity than combustion materials such as solid fuel, to the combustion cell 25. The supply port 8a of the low-density combustion material supply section 8 is located below the combustion material inlet 29a of the combustion material inlet section 29, and above the upper surface of the fluidized bed 22 of the fluidized bed section 20. The low-density combustion material supply section 8 is located on the wall of the fluidized bed furnace 2.

[0028] In this embodiment, the low-density combustion material 200, which is introduced into the fluidized bed 22 from the low-density combustion material supply unit 8, is transported by a gas transport device 80. The gas transport device 80 transports the low-density combustion material 200, which is supplied from the hopper 81 to the low-density combustion material supply passage 82 via the pressure equalization system 83, to the low-density combustion material supply unit 8 by gas and then introduced (supplied) into the fluidized bed 22.

[0029] In the first combustion equipment 1, a portion of the exhaust gas discharged from the fluidized bed furnace 2 is used for gas transport of the low-density combustion body 200. In this embodiment, an exhaust gas supply device 7 is provided to supply a portion of the exhaust gas that has passed through the dust collector 62 to the gas transport device 80. The exhaust gas supply device 7 has an exhaust gas supply passage 70 that connects the second gas duct 63 and the low-density combustion body supply passage 82. The exhaust gas supply passage 70 is equipped with a supply fan 71. The low-density combustion body 200 is dispensed from the hopper 81 by a pressure equalization system 83. The pressure equalization system 83 has a metering feeder 83a provided at the bottom of the hopper 81, an upper rotary valve 83b, a pressure equalization hopper 83c, and a lower rotary valve 83d provided at the bottom of the metering feeder 83a. The pressure equalization system 83, using a quantitative feeder 83a, an upper rotary valve 83b, and a lower rotary valve 83d, can supply a predetermined amount of low-density combustion material 200 per unit time from the hopper 81 to the low-density combustion material supply passage 82 via the pressure equalization hopper 83c. The rotary valves 83b and 83d pressure-isolate the pressure equalization hopper 83c and the low-density combustion material supply passage 82. The low-density combustion material 200 is supplied to the low-density combustion material supply passage 82 by free fall via the pressure equalization system 83, transported to the low-density combustion material supply section 8 by exhaust gas sent from the supply fan 71, and then introduced (supplied) into the fluidized bed 22. The low-density combustion material 200 introduced into the fluidized bed 22 from the low-density combustion material supply section 8 can be appropriately delivered to the combustion cells 25 of the fluidized bed 22 by adjusting the velocity of the exhaust gas with the supply fan 71. The exhaust gas velocity may also be adjusted by installing a flow rate control device such as a damper in the exhaust gas supply device 7 or the gas transport device 80.

[0030] As shown in Figure 2, the low-density combustion body supply unit 8 of this embodiment is equipped with a water cooling device 85. The water cooling device 85 has a double-pipe structure for the low-density combustion body supply unit 8, with the central part serving as a passage 84 for the low-density combustion body 200, and the area surrounding the passage 84 serving as a water cooling section 86. The tip shape of the passage 84, such as its diameter, can be shaped to allow the low-density combustion body 200 to reach the combustion cell 25 of the fluidized bed 22. The water cooling section 86 supplies cooling water 87 from one side of the base of the low-density combustion body supply unit 8, and discharges the cooling water 87 that has flowed to the tip (furnace direction) of the low-density combustion body supply unit 8 from the other side of the base of the low-density combustion body supply unit 8. In other words, in this embodiment, the water cooling section 86 is supplied with cooling water 87 from a water inlet 88 located outside the fluidized bed furnace 2, and the cooling water that has flowed inward into the fluidized bed furnace 2 reverses direction at the tip and is discharged from a drain port 89 located outside the fluidized bed furnace 2. The structure of the water-cooling section 86 may be a configuration other than a double-tube structure, and is not limited to this embodiment.

[0031] In this embodiment, the low-density combustion material supply unit 8 is provided at a predetermined angle θ with respect to the wall surface of the fluidized bed furnace 2. The angle θ can be set to the angle at which the low-density combustion material 200 supplied from the tip of the low-density combustion material supply unit 8 into the fluidized bed furnace 2 is injected toward the combustion cells 25 of the fluidized bed 22.

[0032] With the first combustion equipment 1 configured as described above, the low-density combustion body 200 can be supplied to the fluidized bed 22 from the supply port 8a of the low-density combustion body supply unit 8, which is provided between the combustion body inlet 29a of the combustion body input section 29 of the fluidized bed furnace 2 and the upper surface of the fluidized bed 22. Therefore, the low-density combustion body 200 can be supplied to the fluidized bed 22 from a position close to the fluidized bed 22, and the low-density combustion body 200 can be properly delivered to the fluidized bed 22 and burned. As a result, even when the low-density combustion body 200 is used as fuel, the bed temperature can be properly maintained.

[0033] Furthermore, since the low-density combustion material 200 is transported as a gas by exhaust gas, combustion of the low-density combustion material 200 is suppressed from the time it is introduced into the fluidized bed furnace 2 until it reaches the fluidized bed 22. This makes it possible to supply the low-density combustion material 200 to the combustion cell 25 more appropriately.

[0034] (Second Embodiment) Figure 3 is a schematic diagram showing the second combustion equipment 100 according to the second embodiment. The second combustion equipment 100 is an example in which the gas used to transport the low-density combustion body 200 is different from the exhaust gas. In the first combustion equipment 1 described above, the low-density combustion body 200 transported by the gas transport device 80 was the exhaust gas supplied by the exhaust gas supply device 7, but in the second combustion equipment 100, the low-density combustion body 200 is transported by air. Note that the second combustion equipment 100 and the first combustion equipment 1 are identical except for the configuration in which the low-density combustion body 200 is transported, so the same reference numerals are used for identical components and their explanations are omitted.

[0035] The gas conveying device 80 of the second combustion equipment 100 is equipped with a conveying fan 75 that conveys the low-density combustion material 200, which is supplied from the hopper 81 to the low-density combustion material supply passage 82 via the pressure equalization system 83, to the low-density combustion material supply section 8. The conveying fan 75 is an example of supplying air to the low-density combustion material supply passage 82 via the supply passage. Alternatively, the conveying fan 75 may supply other gases (including gases) to the low-density combustion material supply passage 82 and convey the low-density combustion material 200 by gas.

[0036] Furthermore, according to the second combustion equipment 100, by supplying additional air from the conveying fan 75 to the supply passage 76 connected to the outlet of the pressure equalization system 83 installed below the hopper 81, additional air for adjusting the in-bed air ratio can be supplied to the fluidized bed 22 via the low-density combustion material supply passage 82 and the supply port 8a of the low-density combustion material supply section 8. In this specification and the claims, "in-bed air ratio" refers to "air ratio contributing to in-bed combustion." The additional air is injected towards the top of the combustion cell 25 of the fluidized bed 22. The velocity of the additional air can be greater than the empty tower velocity at the combustion cell 25. By making the injection velocity of the additional air greater than the empty tower velocity, the additional air can be appropriately supplied to the combustion cell 25 of the fluidized bed 22. The supply amount and flow velocity of the additional air can be adjusted by the conveying fan 75. Note that the velocity of the additional air may also be adjusted by installing a flow rate adjustment device such as a damper on the gas conveying device 80. Since the other components of the second combustion equipment 100 are the same as those of the first combustion equipment 1 described above, a description of the other components will be omitted.

[0037] As described above, the second combustion equipment 100 can also supply the low-density combustion body 200 to the fluidized bed 22 from the supply port 8a of the low-density combustion body supply unit 8, which is located between the combustion body inlet 29a of the combustion body input section 29 of the fluidized bed furnace 2 and the upper surface of the fluidized bed 22. Therefore, the low-density combustion body 200 can be supplied to the fluidized bed 22 from a position close to the fluidized bed 22, making it possible to properly deliver the low-density combustion body 200 to the fluidized bed 22 and burn it. As a result, even when using the low-density combustion body 200 as fuel, it is possible to properly maintain the bed temperature.

[0038] Furthermore, the second combustion equipment 100 allows additional air to be supplied to the fluidized bed 22 from the conveying fan 75. This means that, even when the type of combustion element is changed, the in-bed air ratio can be altered by supplying additional air from the additional air supply unit. This ensures that the in-bed empty velocity remains within a certain range even when the type of fuel is changed. Therefore, the initially planned boiler evaporation rate can be maintained even when the type of fuel is changed.

[0039] (Third embodiment) Figure 4 is a schematic diagram showing a third combustion equipment 110 according to the third embodiment. The third combustion equipment 110 is an example in which a configuration for supplying additional air to the fluidized bed 22 is added to the configuration of the first combustion equipment 1 described above. Note that the third combustion equipment 110 and the first combustion equipment 1 are identical except for the configuration related to the additional air supply device 9, so the same reference numerals are used for identical components and their descriptions are omitted.

[0040] The third combustion equipment 110 is equipped with an additional air supply device 9 that supplies additional air for adjusting the in-bed air ratio of the fluidized bed 22, in addition to the configuration of the first combustion equipment 1. In this embodiment, the additional air supply device 9 has an additional air supply passage 90 connected to a three-way valve 92 provided in the exhaust gas supply passage 70. An additional air supply fan 91 is provided in the additional air supply passage 90.

[0041] According to the third combustion equipment 110, an additional air supply passage 90 is connected to an exhaust gas supply passage 70 connected to the outlet of a pressure equalization system 83 installed below the hopper 81 by a three-way valve 92, and additional air is supplied to the additional air supply passage 90 from an additional air supply fan 91. This allows additional air to be supplied to the fluidized bed 22 from the supply port 8a of the low-density combustion body supply section 8 via the three-way valve 92 and the low-density combustion body supply passage 82 provided in the exhaust gas supply passage 70. The additional air is injected towards the top of the combustion cell 25 of the fluidized bed 22. The velocity of the additional air can be made greater than the empty tower velocity at the combustion cell 25. By making the injection velocity of the additional air greater than the empty tower velocity, the additional air can be appropriately supplied to the combustion cell 25 of the fluidized bed 22. The supply amount and flow velocity of the additional air can be adjusted by the additional air supply fan 91. The additional air supply device 9 should be provided in case the empty tower velocity changes due to a change in the combustion body introduced into the fluidized bed 22, etc. Since the other components of the third combustion unit 110 are the same as those of the first combustion unit 1 described above, a description of the other components will be omitted.

[0042] As described above, the third combustion equipment 110 can also supply the low-density combustion body 200 to the fluidized bed 22 from the supply port 8a of the low-density combustion body supply unit 8, which is located between the combustion body inlet 29a of the combustion body input section 29 of the fluidized bed furnace 2 and the upper surface of the fluidized bed 22. Therefore, the low-density combustion body 200 can be supplied to the fluidized bed 22 from a position close to the fluidized bed 22, making it possible to properly deliver the low-density combustion body 200 to the fluidized bed 22 and burn it. As a result, even when using the low-density combustion body 200 as fuel, it is possible to properly maintain the bed temperature.

[0043] Furthermore, the third combustion unit 110 allows for the supply of additional air from the conveying fan 75 to the fluidized bed 22 for adjusting the in-bed air ratio. This means that, even when the type of combustion element is changed, the in-bed air ratio can be altered by supplying additional air from the additional air supply unit. As a result, even when the type of fuel is changed, the in-bed empty velocity can be kept within a certain range. Therefore, even when the type of fuel is changed, the initially planned boiler evaporation rate can be maintained.

[0044] (modified version) Figure 5 is a schematic diagram showing a modified configuration of the fluidized bed furnace 2. Figure 5 shows only the fluidized bed 22 portion in the above-described embodiment, and only configurations that differ from the above-described embodiment will be explained, while identical configurations will be denoted by the same reference numerals and their explanations will be omitted. In the modified configuration shown in Figure 5, the fluidized air supply unit that supplies fluidized air to the fluidized bed 22 uses a diffuser pipe system in which fluidized air is ejected from a diffuser pipe 38 provided inside the fluidized bed 22. Since known technology can be used for the configuration of supplying air to the diffuser pipe 38, an explanation will be omitted. Also in Figure 5, the fluidized bed 22 consists of a combustion cell 25 in the central part and heat recovery cells 27 formed on both sides of it. The combustion cell 25 and the heat recovery cells 27 are separated by a first partition wall 23. Note that in any of the first combustion equipment 1, second combustion equipment 100, and third combustion equipment 110, the fluidized air supply unit that supplies fluidized air to the fluidized bed 22 may be either a dispersion plate system or a diffuser pipe system. Furthermore, the fluidized bed 22 may have a configuration that includes a circulation cell 26, or a configuration that does not include one.

[0045] In the above embodiment, the low-density combustion material supply unit 8 is shown as being in one location, but the low-density combustion material supply unit 8 may be provided in multiple locations. For example, it may be provided at positions opposite the fluidized bed unit 20.

[0046] Furthermore, in the above embodiment, the combustion cell 25 is provided with circulation cells 26 and heat recovery cells 27 on both sides, but the configuration can also be applied to one side only, where the circulation cells 26 and heat recovery cells 27 are provided. If there is no circulation cell 26, the configuration can also be applied to one side only, where the heat recovery cells 27 are provided.

[0047] Furthermore, although the above embodiment describes an example of a fluidized bed furnace 2 with an internal circulation system, it can also be applied to other types of fluidized bed furnaces such as those with an external circulation system and a bubbling system.

[0048] Furthermore, the configurations and combinations thereof in the embodiments described above are merely examples, and additions, omissions, substitutions, and other modifications can be made as appropriate without departing from the spirit of the present invention. The present invention is not limited by the embodiments, but is limited only by the scope of the claims.

[0049] (summary) The combustion equipment 1,100,110 according to the present invention is a combustion equipment that burns a combustion body in a fluidized bed 22 formed inside, and comprises a fluidized bed furnace 2 provided at the bottom for injecting fluidized air into the fluidized bed 22, and a combustion body input section provided at the top for supplying the combustion body to the fluidized bed 22, wherein the fluidized bed furnace 2 comprises a low-density combustion body supply section 8 between the input port of the combustion body input section and the top of the fluidized bed 22 for supplying a low-density combustion body 200 having a lower specific gravity than the combustion body to the fluidized bed 22.

[0050] This configuration allows a low-density combustion element 200, which has a lower specific gravity than the combustion element, to be supplied to the fluidized bed 22 from a low-density combustion element supply unit 8 located between the inlet of the combustion element input unit (such as a solid fuel) and the upper surface of the fluidized bed 22. Therefore, by supplying the low-density combustion element 200 to the fluidized bed 22 from a position close to the fluidized bed 22, the low-density combustion element 200 can be properly delivered to the fluidized bed 22 and burned.

[0051] Furthermore, the fluidized bed furnace 2 has a fluidized bed section including the fluidized bed 22 and a freeboard section 21 for secondary combustion formed above the fluidized bed section, and the low-density combustion material supply section 8 is the fluidized bed section of the fluidized bed furnace 2, and may have a supply port above the upper surface of the fluidized bed 22. With this configuration, the low-density combustion material 200 can be supplied from a supply port provided in the fluidized bed section near the upper surface of the fluidized bed 22, and the low-density combustion material 200 can be appropriately delivered to the fluidized bed.

[0052] Furthermore, the fluidized bed 22 may have a heat-recovering cell 27 and a combustion cell 25, and the low-density combustion material supply unit 8 may be set at an angle such that the low-density combustion material 200 is injected from the tip of the low-density combustion material supply unit 8 toward the combustion cell 25. With this configuration, the low-density combustion material 200 can be appropriately injected from the tip of the low-density combustion material supply unit 8 toward the combustion cell 25 inside the fluidized bed furnace 2.

[0053] Furthermore, the system may also include a gas transport device 80 that uses a portion of the exhaust gas discharged from the fluidized bed furnace 2 to transport the low-density combustion body 200. With this configuration, the low-density combustion body 200 is supplied to the fluidized bed furnace 2 from the low-density combustion body supply unit 8 together with the exhaust gas. Therefore, when the low-density combustion body 200 is supplied to the fluidized bed furnace 2, the exhaust gas suppresses the start of combustion of the low-density combustion body 200, allowing the low-density combustion body 200 to reach the fluidized bed 22 appropriately.

[0054] Furthermore, the gas transport device 80 may be configured to adjust the velocity of the exhaust gas. With this configuration, the velocity of the exhaust gas can be changed according to the low-density combustion body 200, and the low-density combustion body 200 can be appropriately supplied to the combustion cell 25 of the fluidized bed furnace 2.

[0055] Furthermore, the low-density combustion material supply unit 8 may also be equipped with a water cooling device 85 that cools a predetermined area from the wall surface of the fluidized bed furnace 2. With this configuration, the risk of the low-density combustion material 200, such as fluff, softening and adhering inside the low-density combustion material supply unit 8 can be suppressed.

[0056] Furthermore, the system may be equipped with an additional air supply device 9 that supplies additional air to the fluidized bed 22 via the low-density combustion element supply unit 8 for adjusting the in-bed air ratio. With this configuration, the in-bed air ratio can be changed by the additional air when the type of combustion element is changed. This allows the empty bed velocity to be kept within a certain range. Therefore, even if the type of fuel element is changed, the initially planned boiler evaporation rate can be secured. [Explanation of Symbols]

[0057] 1. First Combustion Equipment 2 Fluidized bed furnace 3. Fluidized air supply device 5 Boiler 7. Exhaust gas supply system 8 Low specific gravity combustion body supply section 8a Supply port 9. Additional air supply device 10 Fluid medium 20. Fluidized bed section 21 Freeboard Section 22 Fluidized bed 23. First partition wall 24. Second partition wall 25 Combustion Cells 26 Circulating Cells 27 Heat-recovering cells 28 Heat exchanger 29 Combustion element input section 29a Combustion element inlet 30 Air supply port (fluidized air supply section) 31 Combustion cell air supply device 31a Flow control device 32 Circulating cell air supply device 32a Flow control device 33 Heat Recovery Cell Air Supply System 33a Flow control device 34 First Fan 35 Combustion cell air 36 Circulating cell air 37 Heat-absorbing cell air 38 Air diffuser 39. Tertiary air supply unit 40 Third supply route 41 Second Fan 42 Third air 45 Hopper 46 Outlet 50 1st flue 51 Second flue 52 Heat exchanger 53 Heat exchanger 61. First Gas Duct 62 Dust collector 63 Second Gas Duct 64 Inducing Fan 65 Chimney 70 Exhaust gas supply line 71 Supply Fan 75 Conveyor Fan 76 Supply route 80 Gas conveying device 81 Hopper 82 Low specific gravity combustion body supply path 83 Pressure Equalization System 83a Metering machine 83b Upper rotary valve 83c pressure equalizing hopper 83d Lower rotary valve 84 aisle 85 Water cooling system 86 Water cooling section 87 Cooling water 88 Water inlet 89 Drain 90 Additional air supply channels 91 Additional air supply fan 92 3-way valve 100 Second Combustion Facility 110 Third Combustion Facility 200 Low specific gravity combustion body

Claims

1. A combustion apparatus that burns a combustible material in a fluidized bed formed inside, A fluidized bed furnace having a fluidized bed section including the fluidized bed and a free board section for secondary combustion formed above the fluidized bed section, comprising: a fluidized air supply section for injecting fluidized air into the fluidized bed; a combustion body input section disposed in the free board section for supplying the combustion body to the fluidized bed; and a low-density combustion body supply section having a supply port disposed between the combustion body input port of the combustion body input section and the upper surface of the fluidized bed, from which a low-density combustion body having a lower specific gravity than the combustion body is injected toward the upper part of the fluidized bed, The airflow conveying device includes a supply path connected to the low-density combustion body supply section, a supply machine that supplies the low-density combustion body to the supply path, a fan that supplies additional air containing at least one of air or exhaust gas from the fluidized bed furnace to the supply path, and a flow rate adjustment device that adjusts the flow rate of the additional air. The low-density combustion element supply unit is configured to inject the low-density combustion element and the additional air for adjusting the in-layer air ratio, whose rate is adjusted by the flow rate adjustment device. Combustion equipment equipped with a supply section for low-density combustion material.

2. The fluidized bed furnace has partition walls that divide the fluidized bed into a plurality of cells, each including a heat recovery cell for recovering heat and a combustion cell for burning the combustion material, The low-density combustion material supply unit is set at an angle such that the low-density combustion material is injected from the tip of the low-density combustion material supply unit toward the upper part of the combustion cell. A combustion apparatus comprising a supply unit for low-density combustion material as described in claim 1.

3. The low-density combustion material supply unit is equipped with a water cooling device that cools a predetermined range from the wall surface of the fluidized bed furnace, including the low-density combustion material supply unit or the low-density combustion material supply unit. A combustion apparatus comprising a supply unit for low-density combustion material according to claim 1 or 2.

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