JP5439115B2 - Powder fuel-fired combustion device - Google Patents

Description

  The present invention relates to a combustion apparatus that burns pulverized fuel, such as a pulverized coal-fired boiler that performs multi-stage injection of combustion air and performs denitration in the furnace.

2. Description of the Related Art As a conventional combustion apparatus, there is known a pulverized coal fired boiler that uses pulverized coal obtained by pulverizing coal as fuel and burns the pulverized coal in a boiler to generate steam. In such a pulverized coal fired boiler, a combustion method in which combustion air is introduced in multiple stages has already been established for denitration in the furnace.
That is, in the combustion method in which air is introduced in multiple stages, an additional air nozzle provided as an additional air at the upper part of the furnace (downstream side in the furnace) as additional air for about 30% of the combustion air required for combustion in the boiler. (Hereinafter referred to as “AA nozzle”). In order to further enhance the denitration effect in the furnace, a hydrocarbon-based fuel is introduced into the reduction zone from the burner to the installation position of the AA nozzle (AA portion). (For example, see Patent Document 1)

  There is also known a technique in which a gasification furnace is installed immediately before a conventional boiler and the generated gasification gas is charged at a high temperature (650 to 750 ° C.). In this case, the gasification gas is introduced at the lower portion of the burner, and in the case where the biomass gasification gas is co-fired, the nitrogen oxide (NOx) reduction rate remains at about 5 to 10%.

JP 2006-023076 A

By the way, since the prior art described in Patent Document 1 described above uses the same fuel as a denitration agent, there is a concern about an increase in unburned outlet. And in order to improve such an increase in the amount of unburned exit, it is assumed that the furnace must be enlarged. For this reason, it is known that the denitration fuel suitable for reducing the unburned content is gas, light liquid fuel, or the like.
Moreover, solids such as waste, biomass, and coal are gasified in a fluidized bed gasifier, and are produced in various combustion devices (boilers, lime kilns, etc.) in which this combustible gas is supplied as fuel. Inflammable gas (char) and fine particles such as fluidized material are mixed in the combustible gas. These fine particles are burned by a combustor installed in the downstream, but when a combustible gas containing fine particles is used as fuel, a usable burner type (powder burner is required) ) And the input position of the combustion device are restricted.

In particular, in order to completely burn the unburned matter in the fine particles, the residence time in the furnace in the combustion apparatus is required. Therefore, the combustible gas containing fine particles is burned in the lower stage of the furnace (or residence time). It is desirable to put in more than the position where you can earn.
On the other hand, gas fuel is more combustible than powdered fuel (solid fuel) such as pulverized coal, so it is more powdery to be charged from the burner (or the downstream part of the furnace) located in the upper stage of the furnace. It is thought that there is little influence on fuel combustion.

Against this background, a pulverized coal fired boiler that effectively uses high-temperature combustible gas, such as gasified gas, and can reduce the amount of nitrogen oxides and unburned fuel generated by mixing and burning with pulverized coal in the furnace. Thus, development of a combustion apparatus for burning pulverized fuel is desired. In recent thermal power plants, there is a demand for technology for co-firing biomass with a pulverized coal-fired boiler for the purpose of effective use of renewable energy for reducing carbon dioxide emissions.
The present invention has been made in view of the above circumstances. The object of the present invention is to mix and burn high-temperature combustible gas with pulverized fuel such as pulverized coal in a furnace so An object of the present invention is to provide a combustion apparatus capable of reducing the amount of generated fuel.

In order to solve the above problems, the present invention employs the following means.
According to a first aspect of the present invention, there is provided a combustion apparatus comprising: a pulverized fuel burner disposed in a lower part of a furnace; and an additional air charging nozzle disposed above the pulverized fuel burner. In a combustion apparatus using pulverized coal fuel that performs multi-stage injection of combustion air from an injection nozzle and performs denitration in the furnace, the high-temperature and combustible gas generated in the gasification furnace is at the same level as the additional air injection nozzle. includes gases and installed premixing type burner for burning premixture with air Rutotomoni, a solid / gas separating device for the solids contained in the gasification gas provided on the upstream side separated from the gas, the solid was separated by solid / gas separating device is supplied to the pulverized fuel burner, the gas separated in the solid / gas separating device is characterized in that there use as the combustible gas.

According to such a pulverized fuel burning combustion device, premixing of high-temperature and combustible gasification gas generated in the gasification furnace and air at a height level equivalent to the additional air charging nozzle in the furnace. Since the premixing burner for burning the gas is installed, the amount of pulverized fuel input from the pulverized fuel burner can be reduced by the amount of combustible gas input. As a result, in the reduction zone in the furnace formed between the premixing burner and the additional air injection nozzle, the flame residence time becomes longer due to the reduction of the combustion gas, so that the nitrogen oxides generated by the combustion are reduced. be able to.
In addition, by adopting a premixing method in which high temperature premixed gas is burned, the unburned content of the combustible gas can be reduced.
In addition, since the high-temperature and combustible gasification gas generated in the gasification furnace is supplied to the furnace, the high-temperature combustible gas can be easily introduced and co-fired with the pulverized fuel. As gasification gas in this case, what gasified solid fuels, such as coal, biomass, a waste material, and a tire, can be used.
In addition, the solid separated by the solid / gas separation device is supplied to the pulverized fuel burner, and the gas separated by the solid / gas separation device is used as a flammable gas. It is possible to improve the combustibility of the solid fuel by increasing the residence time of the solid fuel in the furnace and preventing rapid consumption of oxygen by the gas.

According to a second aspect of the present invention, there is provided a combustion apparatus comprising: a pulverized fuel burner disposed in a lower part of a furnace; and an additional air charging nozzle disposed above the pulverized fuel burner. In a combustion apparatus using a pulverized fuel that performs multistage injection of combustion air from an injection nozzle and performs denitration in the furnace, high-temperature and combustible gas generated in a gasification furnace in secondary air of the pulverized fuel burner A premixed gas that has been premixed by introducing a gasification gas is mixed and burned with pulverized fuel, and a solid / gas separation device that is provided upstream and separates solids contained in the gasification gas from the gas, The solid separated by the solid / gas separator is supplied to the pulverized fuel burner, and the gas separated by the solid / gas separator is used as the combustible gas .

According to such a pulverized fuel-burning combustion apparatus, a premixed gas in which high-temperature and combustible gasified gas generated in a gasification furnace is premixed in secondary air of a pulverized fuel burner. Is mixed and combusted with the pulverized fuel, so that the secondary air of the pulverized fuel burner can be heated to a high temperature by introducing the premixed high-temperature fuel to reduce the generation of nitrogen oxides and unburned components.
Moreover, while increasing the residence time of the solid (solid fuel) having low combustibility compared with the gas and preventing rapid consumption of oxygen by the gas, the combustibility of the solid fuel can be improved.

According to a third aspect of the present invention, there is provided a combustion apparatus comprising: a pulverized fuel burner disposed in a lower portion of a furnace; and an additional air charging nozzle disposed above the pulverized fuel burner, wherein the additional air is provided. In a powder fuel-fired combustion device that performs multi-stage injection of combustion air from an injection nozzle and performs in-furnace denitration, a premixed mixture of high-temperature and combustible gasification gas and air generated in the gasification furnace A solid / gas separation device is provided at the bottom for mixing and burning with the pulverized fuel and separating the solid contained in the gasification gas from the gas, and is separated by the solid / gas separation device. The solid thus supplied is supplied to the pulverized fuel burner, and the gas separated by the solid / gas separator is used as the combustible gas .

According to such a pulverized fuel-fired combustion apparatus, a premixed mixture of high-temperature and combustible gasified gas and air generated in a gasification furnace is introduced into the bottom of the furnace and mixed with pulverized fuel. Therefore, the unburned content can be reduced by introducing the premixed high-temperature fuel.
Moreover, while increasing the residence time of the solid (solid fuel) having low combustibility compared with the gas and preventing rapid consumption of oxygen by the gas, the combustibility of the solid fuel can be improved.

In the pulverized fuel-fired combustion apparatus, the gasification furnace is a circulating fluidized bed gasification furnace, and a hole is formed in an inner cylinder wall surface of a centrifugal separator provided at a product gas outlet of the circulating fluidized bed gasification furnace. It is preferable to provide a large number of unburned material passage holes whose diameter is smaller than the average particle size of the fluidized material, whereby a gas and particles (fluidized material such as silica sand + unburned material) are separated from the circulating fluidized bed gasifier. In the centrifuge, the unburned matter with a low specific gravity in the particles is actively separated to the gas side through a large number of unburned matter passage holes, so when a combustion device is installed in the downstream, It becomes possible to increase the fuel flow rate (heat generation amount) supplied to the combustion device.

According to a fifth aspect of the present invention, there is provided a combustion apparatus comprising: a pulverized fuel burner disposed in a lower portion of a furnace; and a gas burner disposed above the pulverized fuel burner; A solid / gas separation device for separating solids contained in the combustible gasification gas from the gas, and supplying the solid separated by the solid / gas separation device to the pulverized fuel burner; The gas separated by the solid / gas separation device is supplied to the gas burner, and the gasification furnace is a circulating fluidized bed gasification furnace, and the inside of the centrifugal separator provided at the product gas outlet of the circulating fluidized bed gasification furnace The cylindrical wall surface is provided with a large number of unburned part passage holes whose hole diameter is smaller than the average particle diameter of the fluidized material .

According to such a pulverized fuel burning combustion device, a solid / gas separation device for separating solids contained in combustible gasification gas generated in a gasification furnace from the gas is provided on the upstream side, Since the solid separated by the gas separator is supplied to the powder fuel burner and the gas separated by the solid / gas separator is supplied to the gas burner, the existing powder fuel burner and gas burner are used, While improving the combustibility of the solid used as the fuel of the pulverized fuel burner, the amount of NOx generated can be reduced by the reducing action.
Moreover, in the circulating fluidized bed gasifier centrifuge that separates gas and particles (silica sand and other fluidized material + unburned matter), the unburned matter with a light specific gravity in the particles passes through many unburned component passage holes. Since the gas is actively separated to the gas side, it is possible to increase the flow rate of fuel (heat generation amount) supplied to the combustion device when the combustion device is installed downstream.

According to the present invention described above, a high-temperature combustible gas (such as a high-temperature gasification gas of a solid fuel produced in a gasification furnace) is premixed with air, and is introduced into the furnace from the same level as the additional air injection nozzle. Since it is mixed and burned with powdered fuel (solid fuel) such as pulverized coal, it is possible to provide a combustion device for pulverized coal burning such as a pulverized coal-fired boiler with reduced generation amount of nitrogen oxides and unburned components. . In this case, the amount of combustion gas generated by the combustion of the pulverized fuel decreases according to the co-firing ratio of the combustible gas, so that the nitrogen oxide can be reduced as the amount of combustion gas decreases. Become.
In addition, when premixed gas that has been premixed by injecting high-temperature combustible gas into the secondary air of the pulverized fuel burner is mixed and combusted with pulverized coal, the secondary air of the pulverized fuel burner is heated to a higher temperature and oxidized with nitrogen. When it becomes a combustion device for pulverized coal burning such as a pulverized coal burning boiler that can reduce the generation of substances, a premixed gas of high temperature combustible gas and air is introduced into the bottom of the furnace and mixed with pulverized fuel, It becomes a combustion apparatus for pulverized fuel burning such as a pulverized coal burning boiler with reduced generation of unburned matter.
In addition, in a combustion device using pulverized fuel, renewable energy such as biomass can be co-fired with pulverized coal and other pulverized fuel, and therefore, effective use of renewable energy to reduce carbon dioxide emissions. Is possible.

1 is a configuration diagram showing a first embodiment of a pulverized fuel burning combustion apparatus (pulverized coal burning boiler) according to the present invention. It is a block diagram which shows 2nd Embodiment about the combustion apparatus (pulverized coal burning boiler) of the pulverized fuel burning which concerns on this invention. It is a block diagram which shows 3rd Embodiment about the combustion apparatus (pulverized coal burning boiler) of the pulverized fuel burning which concerns on this invention. It is a block diagram which shows the example applied to a circulating fluidized bed gasification furnace as an example of installation of the solid / gas separation apparatus provided in the upstream of a combustion apparatus, and isolate | separating the solid contained in gasification gas from gas. As an installation example of a solid / gas separation device that is provided upstream of a combustion device and separates solids contained in gasification gas from gas, an application example to a bubble type fluidized bed gasification furnace is shown in the figure. is there. It is a longitudinal cross-sectional view which shows the structural example of the centrifuge provided in the product gas exit of a circulating fluidized bed gasification furnace. It is a cross-sectional view of the centrifuge shown in FIG.

Hereinafter, an embodiment of a pulverized coal burning boiler according to an embodiment of the present invention applied to a pulverized coal burning boiler will be described with reference to the drawings.
<First Embodiment>
In the embodiment shown in FIG. 1, a pulverized coal fired boiler (powder fuel fired combustion apparatus) 10 is provided with a burner portion 12 in a lower part of the furnace 11. The burner unit 12 is provided with a plurality of coal burners (powder fuel burners) 13 that are charged with pulverized coal as pulverized fuel and burned, and are supplied with pulverized coal and secondary air.
Further, an additional air input part (AA part) 15 provided with an additional air input nozzle (AA nozzle) 14 is provided above the coal burner 13 of the furnace 11. The amount of air introduced here is about 30% of the amount of air necessary for the pulverized coal to burn in the furnace 11. That is, the pulverized coal burning boiler 10 is configured to perform denitration in the furnace by introducing combustion air from the AA nozzle 14 in multiple stages from the burner section 12 to the AA section 15.
Reference numeral 16 in the figure denotes a heat exchanger group arranged in a plurality so as to generate steam by heat exchange with a high-temperature combustion gas, and 17 denotes a denitration apparatus that performs denitration of the combustion gas.

  In the pulverized coal-fired boiler 10 configured in this way, a pre-combustion gas of high-temperature combustible gas and air is preliminarily burned at a height level equivalent to that of the AA nozzle 14, that is, in the area of the AA portion 15. A mixing type burner (hereinafter referred to as “premixed burner”) 20 is installed. In this case, the premixed gas is set so that the premixing ratio is out of the flammable range from the relationship between the composition of the combustible gas and the temperature to prevent spontaneous ignition.

The premix burner 20 premixes a combustible product gas (gasification gas) obtained by gasifying solid fuel such as coal, biomass, waste, and tires with air to reach the uppermost level in the furnace 11. It is injected from the AA section 15 and burned. In the illustrated configuration example, a gasification furnace 30 that receives supply of solid fuel is adjacent, and a high-temperature generated gas gasified in the gasification furnace 30 is used as a combustible gas. Therefore, the premix burner 20 can easily secure a high-temperature combustible gas from the adjacent gasification furnace 30.
Reference numeral 31 in the figure denotes a centrifuge (hopper) that separates and removes unburned solid fuel (char) from the gasification gas, and 32 heats the air supplied to the gasification furnace 30 with a high-temperature gasification gas. Therefore, it is a heat exchanger provided as necessary.

  Further, on the downstream side of the above-described pulverized coal fired boiler 10, for example, facilities such as a dust collector 40 and a desulfurizer 50 are provided in order to process the combustion gas after steam generation and denitration. The combustion gas thus subjected to various treatments such as dust collection and desulfurization is finally discharged from the chimney 60 to the atmosphere as exhaust gas.

The pulverized coal-fired boiler 10 having the above-described configuration is a main burner because the combustible gas pre-mixed from a height level equivalent to the additional air input is input instead of the reduction region lower than the level of the AA unit 15. The amount of gas from the coal burner 13 to the AA section 15, that is, the amount of combustion gas generated by pulverized coal combustion changes according to the mixed firing rate (the ratio of pulverized coal and combustible gas input), and according to the decrease in the amount of combustion gas Therefore, nitrogen oxides can be reduced. In other words, since a high temperature (for example, about 300 to 800 ° C.) combustible gas is supplied from the premix burner 20 in a premixed state with air, the coal burner is equivalent to the amount of combustible gas input (the amount of heat generated by combustion). The amount of pulverized coal input from 13 (the amount of heat generated by combustion) can be reduced. For this reason, in the reduction | restoration area | region in the furnace 11, since the residence time of a flame becomes long by the combustion gas reduction | decrease of pulverized coal, the nitrogen oxide generated by combustion of pulverized coal will reduce.
In addition, since the premixing type premixing burner 20 is employed, it is possible to burn the combustible gas in a good state and complete combustion in a short time to reduce the unburned content. Furthermore, since the high temperature combustible gas is supplied from the premix burner 20, the high combustion temperature can be maintained and the unburned content can be reduced.

<Second Embodiment>
Next, a second embodiment of the pulverized coal-fired combustion apparatus according to the present invention applied to a pulverized coal-fired boiler will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In this embodiment, the high-temperature product gas supplied from the gasification furnace 30 is used as a combustible gas, and this combustible gas is mixed and introduced into the secondary air of the coal burner 13. Therefore, the combustible gas is premixed with the secondary air to become a premixed gas, and this premixed gas is introduced into the furnace 11 from the coal burner 13 together with the pulverized coal. That is, since the pulverized coal-fired boiler (combustion device for pulverized fuel) 10A of the present embodiment is a mixture of high-temperature combustible gas into the secondary air of the coal burner 13 and mixed and combusted with pulverized coal, The high temperature combustible fuel is put into the furnace 11 in a state premixed with the secondary air.

  Also in the pulverized coal fired boiler 10A having such a configuration, a high temperature combustible gas is introduced into the secondary air of the coal burner 13 by a premixing method, and the premixed gas of flammable gas and pulverized coal are mixed and burned. Therefore, when the secondary air of the coal burner 13 is heated, nitrogen oxides and unburned components generated by combustion in the furnace 11 can be reduced.

<Third Embodiment>
Next, a third embodiment in which the pulverized coal burning combustion apparatus according to the present invention is applied to a pulverized coal burning boiler will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In this embodiment, an air-fuel mixture obtained by premixing high-temperature product gas and air is introduced into the bottom of the furnace 11. That is, the pulverized coal burning boiler (powder fuel burning combustion apparatus) 10B of this embodiment premixes the high-temperature combustible gas supplied from the gasification furnace 30 with air, and uses this premixed gas for the coal burner 13. A premixing burner (premixing burner) 20A installed at a lower position is introduced into the bottom of the furnace and mixed and combusted with pulverized coal.

  In the pulverized coal-fired boiler 10B having such a configuration, a premixed gas of high-temperature combustible gas and air is introduced below the coal burner 13 in the furnace 11 from the premixed burner 20A and mixed and burned with the pulverized coal. The unburned fuel can be reduced by introducing the premixed high-temperature fuel.

By the way, in the pulverized coal burning boilers 10, 10A, and 10B of the above-described embodiments, the high-temperature generated gas supplied from the gasification furnace 30 installed nearby is used as the combustible gas. As a result, the high temperature combustible gas can be easily introduced by maintaining the temperature of the high temperature gasification gas generated in the gasification furnace 30 or adjusting the temperature to a necessary gas temperature.
As the generated gas in this case, a gas obtained by gasifying solid fuel such as coal, biomass, waste, and tire in the gasification furnace 30 can be used.

Thus, according to the present invention described above, high temperature combustible gas is premixed with air, and this premixed gas is introduced into the furnace 11 from the same level as the AA nozzle 14 to be mixed and burned with pulverized coal. Therefore, the amount of pulverized coal combustion gas in the furnace 11 is reduced, and the amount of nitrogen oxides and unburned matter generated in the furnace 11 of the pulverized coal burning boiler is also reduced.
Moreover, when high temperature combustible gas is thrown into the secondary air of the coal burner 13 and the premixed gas of flammable gas and pulverized coal are mixed and combusted, the secondary air of the coal burner 13 is heated to nitrogen oxidation. Generation of objects can be reduced.
In addition, when a premixed gas of high temperature combustible gas and air is introduced into the bottom of the furnace and the premixed gas of flammable gas and pulverized coal are mixed and burned, the generation of unburned matter can be reduced. .
Therefore, in the above-described pulverized coal-fired boilers 10, 10A, 10B, the pulverized coal is co-fired with renewable energy such as biomass, thereby enabling effective use of renewable energy for reducing carbon dioxide emissions. .

<Fourth Embodiment>
Next, a pulverized fuel burning combustion apparatus according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
In the configuration example shown in FIG. 4, the gasification furnace 30 is a circulating fluidized bed (CFB) gasification furnace, and the gasification furnace is disposed upstream of the pulverized coal burning boiler 10 as a combustion apparatus. A solid / gas separation device 40 is provided for separating solids contained in the gasification gas (gasification fuel of the generated gas) supplied from 30 from the gas.
The solid / gas separation device 40 is a centrifuge or filter installed in connection with a generated gas pipe 33 that supplies gasified gas from the gasifier (circulating fluidized bed gasifier) 30 to the pulverized coal-fired boiler 10. Yes, it has the function of separating the gasification gas into gas components and solids (fine particles).

When the gasification furnace 30 is a circulating fluidized bed gasification furnace, since a fluidized material such as silica sand is used, the gasified gas separated and removed by the centrifugal separator 31 provided at the product gas outlet is removed from the fluidized material. The pulverized coal burning burner 10 is supplied.
However, the centrifuge 31 cannot completely remove the fine particles, and the gasified gas that has passed through the centrifuge 31 contains fine particles such as unburned matter in addition to the fluidized material. . For this reason, in this embodiment, before supplying the gasification gas produced | generated in the gasification furnace 30 to the pulverized-coal-burning burner 10 installed in the downstream of the centrifuge 31, it is a gas component through the solid / gas separation apparatus 40. And fine particles.

The gas component thus separated, that is, the gas component of the gasification gas from which fine particles have been removed, is supplied to the premixing burner 20 of the pulverized coal burning boiler 10 as a combustible gas.
On the other hand, the fine particles separated by the solid / gas separation device 40 are supplied to the coal burner 13 of the pulverized coal burning boiler 10 located at a lower position (lower stage) than the premixing burner 20.
In this way, solids (solid fuel) that are less combustible than gas, that is, fine particles such as unburned matter, are burned together with pulverized coal as the main fuel in the coal burner 13, thus increasing the residence time in the furnace. In addition, it is possible to improve the combustibility of the solid fuel by preventing the rapid consumption of oxygen by the gas. Furthermore, the reducing action of NOx generated by the combustion of the solid fuel can be promoted by the hydrocarbon in the gas.

  Further, the solid / gas separator 40 described above, for example, a fine particle from a combustible gas generated in a bubble fluidized bed (BFB) gasification furnace like a gasification furnace 30 ′ shown in FIG. They may be separated and supplied to the premixing burner 20 and the coal burner 13 of the pulverized coal burning boiler 10.

Thus, the installation of the solid / gas separation device 40 described above is a case where the gasification furnaces 30 and 30 'are additionally installed in the existing combustion device using solid fuel such as coal to supply the gasification gas. This makes it possible to use the burner for solid fuel and the gas burner provided in the existing combustion apparatus.
That is, for example, like a pulverized coal-fired boiler 10, a combustion apparatus provided with a coal burner 13 disposed in the lower part of the furnace and a gas burner such as a premixing burner 20 disposed above the coal burner 13. However, if the solid / gas separation device 40 is provided on the upstream side in order to separate the solid contained in the combustible gasification gas generated in the gasification furnace 30 from the gas, the solid / gas separation device The solid fine particles separated at 40 can be supplied to the coal burner 13, and the product gas separated by the solid / gas separation device 40 can be supplied to the premix burner 20.

Further, the above-described configuration in which the solid / gas separation device 40 is provided is also effective in a combustion device in which solid main fuel such as pulverized coal is not supplied from the coal burner 13. That is, a combustion apparatus that includes two types of burners including a gas burner that inputs and burns gas components and a solid fuel burner that inputs and burns fine particles, and the solid fuel burner is disposed below the gas burner. Applicable. In this case, since the solid / gas separation device 40 is provided on the distillation side of the combustion device to separate the product gas and the fine particles, it is not necessary to employ a dedicated burner corresponding to the gas component containing the fine particles in the combustion device, Existing gas burners and solid fuel burners can be used.
Accordingly, the combustion apparatus provided with the solid / gas separation device 40 between the gasification furnace 30 and the existing pulverized fuel burner and the solid fuel such as pulverized coal from the coal burner 13 can be used. A gas burner can be used to improve the combustibility of the solid used as the fuel for the powder fuel burner and reduce the amount of NOx generated by the reducing action.

By the way, in the pulverized fuel-fired combustion apparatus 10 provided with the solid / gas separation apparatus 40 described above, when the gasification furnace 10 is a circulating fluidized bed gasification furnace, for example, as shown in FIGS. It is desirable to provide a large number of unburned part passage holes 35 on the inner cylindrical wall surface 34a of the centrifugal separator 31 provided at the product gas outlet of the gasification furnace 10.
That is, the centrifuge 31 has a vertical concentric double tube structure in which an inner cylinder 34 is disposed inside an outer cylinder 36, and a product gas outlet of the gasification furnace 30 is provided on the side wall of the outer cylinder 36. A gas introduction pipe 37 communicating with the gas is connected. The unburned part passage hole 35 of the inner cylinder wall surface 34a has a diameter that is, for example, equal to or less than the average particle diameter of silica sand (circulated sand) used as a fluidized material, and has a large number of through holes drilled in at least a part of the wall surface of the inner cylinder 34. It is a hole.

  The generated gas that has flowed into the outer cylinder 36 from the gas introduction pipe 37 contains fine particles such as silica sand and unburned material as a fluid material, and swirls around the outer periphery of the inner cylinder 34 inside the outer cylinder 36. Flowing. At this time, the microparticles having a large specific gravity present in the swirling flow of the product gas are affected by the centrifugal force and, as indicated by an arrow Pa in the figure, collide with the inner wall of the outer cylinder 36 and move downward. Fall. In this case, the fine particles that fall and separate from the swirling flow of the product gas are mainly fluid materials such as silica sand having a specific gravity and a particle size larger than that of the unburned matter. After flowing out, it flows into the gasifier 30 and is reused.

On the other hand, the unburned matter contained in the swirling flow of the product gas has a smaller specific gravity and particle size than the fluidized material. For this reason, when the unburned portion flows into the inner cylinder 36, it passes through the unburned portion passage hole 35 together with the flow of the generated gas and opens at the lower end portion of the inner tube 34 as indicated by an arrow C in the drawing. Together with the product gas flowing out from the gas outlet 39, it is supplied to the solid / gas separation device 40 from the product gas pipe 33 connected to the upper part of the inner cylinder 34.
Incidentally, the unburned matter is a fine particle having a specific gravity of 1 g / cm ³ or less, smaller than that of silica sand (about 2.7 g / cm ³ ), and a particle size of 50 μm or less and smaller than that of silica sand (about 100 to 200 μm). Therefore, it easily passes through the unburned part passage hole 35 of the inner cylinder surface 34a and is mixed into the air flow of the product gas.

  Thus, in the centrifugal separator 31 that separates the generated gas and particles (fluid material such as silica sand + unburned matter), in the apparatus configuration in which the combustion apparatus such as the pulverized coal burning boiler 10 is installed in the downstream, The structure is such that the unburned matter having a low specific gravity in the particles is actively separated to the combustible product gas side, that is, the unburned matter having a low specific gravity in the particles passes through a large number of unburned portion passage holes 35. Therefore, the fuel flow rate (heat generation amount) supplied to the combustion device can be increased by the amount of unburned fuel.

By the way, in each embodiment mentioned above, although high temperature combustible gas is introduce | transduced from the adjacent gasification furnace 30, a high temperature combustible gas supply source is not limited to this.
Further, the combustion device installed downstream of the solid / gas separation device 40 is not limited to the pulverized coal burning boiler 10 described above, and is applied to the pulverized coal burning boilers 10A and 10B shown in FIGS. May be. That is, the gas component separated by the solid / gas separation device 40 may be used as a generated gas of the pulverized coal-fired boilers 10A and 10B, and the fine particles may be supplied to the coal burner 13 together with the pulverized coal.
In addition, this invention is not limited to embodiment mentioned above, For example, it can change suitably in the range which does not deviate from the summary, such as combining the structure of each embodiment mentioned above.

10, 10A, 10B Pulverized coal burning boiler 11 Furnace 12 Burner section 13 Coal burner (powder fuel burner)
14 Additional air injection nozzle (AA nozzle)
15 Additional air input part (AA part)
20, 20A premixing burner (premixing burner)
30, 30 'Gasifier 31 Centrifugal separator 33 Generated gas pipe 34 Inner cylinder 34a Inner cylinder wall surface 35 Unburned part passage hole 36 Outer cylinder 40 Solid / gas separation device

Claims (5)

A pulverized fuel burner disposed in a lower portion of the furnace, and an additional air charging nozzle disposed above the pulverized fuel burner, and the combustion air is input in multiple stages from the additional air charging nozzle. In a combustion apparatus using a pulverized coal fuel that performs internal denitration,
The additional air injection nozzle the same height level, Rutotomoni is installed premixing type burner for burning premixed gas of high temperature and flammable gasification gas and air generated in the gasification furnace,
A solid / gas separation device provided on the upstream side for separating the solid contained in the gasification gas from the gas, and supplying the solid separated by the solid / gas separation device to the pulverized fuel burner; solid / gas separation combustion device of the powder fuel-burning, characterized in that there use the separated gas as the combustible gas in the apparatus. A pulverized fuel burner disposed in a lower portion of the furnace, and an additional air charging nozzle disposed above the pulverized fuel burner, and the combustion air is input in multiple stages from the additional air charging nozzle. In a powder fuel-fired combustion device that performs internal denitration,
In the secondary air of the pulverized fuel burner, the high-temperature and combustible gasified gas generated in the gasification furnace is charged and premixed and mixed with the pulverized fuel, and premixed ,
A solid / gas separation device provided on the upstream side for separating the solid contained in the gasification gas from the gas, and supplying the solid separated by the solid / gas separation device to the pulverized fuel burner; A powder fuel-fired combustion apparatus using a gas separated by a solid / gas separation apparatus as the combustible gas . A pulverized fuel burner disposed in a lower portion of the furnace, and an additional air charging nozzle disposed above the pulverized fuel burner, and the combustion air is input in multiple stages from the additional air charging nozzle. In a powder fuel-fired combustion device that performs internal denitration,
A premixed gas of high-temperature and combustible gasification gas and air generated in the gasification furnace is introduced into the bottom of the furnace and mixed and burned with the pulverized fuel .
A solid / gas separation device provided on the upstream side for separating the solid contained in the gasification gas from the gas, and supplying the solid separated by the solid / gas separation device to the pulverized fuel burner; A powder fuel-fired combustion apparatus using a gas separated by a solid / gas separation apparatus as the combustible gas .   The gasification furnace is a circulating fluidized bed gasification furnace, and on the inner cylinder wall surface of the centrifuge provided at the product gas outlet of the circulating fluidized bed gasification furnace, The combustion apparatus for burning pulverized fuel according to any one of claims 1 to 3, wherein a fuel passage hole is provided. A pulverized fuel burner disposed in the lower part of the furnace, and a gas burner disposed above the pulverized fuel burner, the solid contained in the combustible gasification gas generated in the gasification furnace A solid / gas separation device for separating from the gas is provided upstream, and the solid separated by the solid / gas separation device is supplied to the pulverized fuel burner, and the gas separated by the solid / gas separation device is Supply to the gas burner ,
The gasification furnace is a circulating fluidized bed gasification furnace, and on the inner cylinder wall surface of the centrifuge provided at the product gas outlet of the circulating fluidized bed gasification furnace, A combustion apparatus for burning pulverized fuel, characterized in that a fuel passage hole is provided .

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