JPWO2019163765A1 - Solid fuel gasifiers, power generators and gasification methods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasification device, a power generation device and a gasification method for a solid fuel which realizes high thermal efficiency and miniaturization by a downdraft type and is less likely to cause clinker. A solid fuel gasifier 10 of the present invention constitutes the gasifier in a solid fuel gasifier that gasifies solid fuel using a downdraft fixed-bed gasifier 70. The lower part of the reaction furnace 77 is provided with an inclined surface 71a that descends from the peripheral edge portion toward the center side in the radial direction while reducing the diameter, and a through hole 71b located at the center of the lowermost end. It is characterized in that compression injection is performed along the inclined surface from the peripheral edge portion toward the through hole. By compressing and injecting the gasifying agent, the ash on the surface of the inclined surface is blown off, so that clinker is less likely to be formed, and the solid fuel existing near the through hole can be intensively heated to an ultra-high temperature to improve thermal efficiency. Can be done. [Selection diagram] Fig. 2

Description

The present invention relates to a solid fuel gasifier, a power generator and a gasification method.

Patent Document 1 (Japanese Unexamined Patent Publication No. 2008-81637) discloses a method and apparatus for gasifying woody biomass that suppresses the generation of clinker.
In the method and apparatus for gasifying woody biomass described in Patent Document 1, a partition plate for partitioning the inside of the furnace is provided, a passage hole penetrating the partition plate is provided vertically, and a blow port for blowing an oxidant is provided on the upper side of the partition plate. This is a method in which a raw material made of woody biomass is put into the furnace above the partition plate using the downdraft type fixed-bed gasification furnace provided in the above, and gasification is performed while blowing an oxidizer from the blow port. It is characterized by blowing water vapor from.

Japanese Unexamined Patent Publication No. 2008-81637

The downdraft type has an advantage that the tar concentration in the flammable gas is low as compared with the updraft type. However, the downdraft type has a demerit that the thermal efficiency is low because the amount of heat is taken away because the solid fuel containing a large amount of water in the upper part of the furnace is first dried.
Another problem with gasification furnaces (gasification equipment) is that in the case of heat treatment, ash adheres to or solidifies inside the furnace (inside the equipment) to form clinker (burnt mass), which is covered with gasified gas. There is a problem that it does not flow because it is blocked, or a problem that it does not flow because it is blocked.

An object of the present invention is to provide a gasification device for solid fuel and a gasification method for improving thermal efficiency and suppressing the generation of clinker.
Another object of the present invention is to provide a power generation device in which the amount of power generation is made more efficient by a gasification device having improved thermal efficiency.
Another object of the present invention is to provide a gasification device, a power generation device, and a gasification method for solid fuel, which are downdraft type, realize high thermal efficiency and miniaturization, and are less likely to cause clinker.

(1)
The solid fuel gasifier according to one aspect is a solid fuel gasifier that gasifies solid fuel using a downdraft fixed-bed gasifier, and the lower part of the reactor that constitutes the gasifier is the periphery. It is equipped with an inclined surface that descends from the portion toward the center side in the radial direction while reducing the diameter, and a through hole located at the center of the lowermost end, and a gasifying agent for gas is applied along the inclined surface from the peripheral portion toward the through hole. It is a compression injection.

In this case, since the gasifying agent can be supplied toward the through hole, the thermal efficiency can be improved and the generation of clinker can be suppressed.

(2)
The solid fuel gasifier according to the second invention is a solid fuel gasifier according to one aspect, in which a gasifying agent is compressed and injected from a plurality of peripheral portions.

In this case, since the gasifying agent can be supplied toward the through hole, the thermal efficiency can be improved and the generation of clinker can be suppressed.

(3)
The solid fuel gasifier according to the third invention is the one aspect or the solid fuel gasifier according to the second invention, in which the gasifier extends in the vertical direction along the outer peripheral surface of the reactor. A flow path for the gasifying agent is provided, and the gasifying agent may flow in the flow path for the gasifying agent from above to below to reach the peripheral portion.

Since the gasifier flow path extends in the vertical direction along the outer peripheral surface of the reactor, the gasifier is heated by passing through the gasifier flow path. As a result, a high-temperature gasifying agent can be injected into the solid fuel, so that a high combustion temperature can be maintained. Further, since the heat used for burning the solid fuel is reused, the gasifier can be made into a gasifier with high thermal efficiency.

(4)
The solid fuel gasifier according to the fourth invention is the solid fuel gasifier according to the first aspect to the third invention, in which the gasifier extends from the upper part of the reactor through the inside to the upper part of the bottom. It may be provided with a stir bar to reach.

In this case, the stirring rod can make the thermal decomposition uniform and prevent the solid fuel cross-linking phenomenon by stirring the solid fuel in the reaction furnace.

(5)
The solid fuel gasifier according to the fifth invention is the solid fuel gasifier according to the first aspect to the fourth invention, in which the gasifier is arranged below the through hole and the grate. May be provided with a drive mechanism for rotating the fuel in a horizontal plane.

By rotating the grate, the charcoal or ash produced by the combustion of solid fuel is prevented from sticking to the gasifier, and the charcoal and the ash or the ash between the charcoals solidify and block in the gasifier. Can be prevented.

(6)
The solid fuel gasifier according to the sixth invention is the solid fuel gasifier according to the first aspect to the fifth invention, in which the gasifier moves from the vicinity of the bottom of the reactor to the periphery of the gasifier flow path. The combustible gas flow path is provided so as to cover the gasification furnace and reach the upper part of the gasification furnace, and the combustible gas may flow from the lower side of the reaction furnace to the upper part of the combustible gas flow path from the lower side to the upper side. ..

In this case, the gasifying agent in the gasifying flow path can be heated by the flammable gas passing through the flammable gas flow path. As a result, since the heat used for burning the solid fuel is reused, it is possible to obtain a gasifier having high thermal efficiency.

(7)
The power generation device according to the other aspect is connected to the gasifier according to any one of claims 1 to 6, an engine that drives flammable gas generated from the gasifier as at least a part of fuel, and an engine. It is equipped with a generator.

In this case, the efficiency of the generator can be increased by improving the thermal efficiency and using the gasification device that suppresses the generation of clinker.

(8)
In the method of gasifying solid fuel according to still another aspect, in the method of gasifying solid fuel using a downdraft fixed-bed gasifier, the lower part of the reactor constituting the gasifier is It has an inclined surface that descends from the peripheral edge toward the center side in the radial direction while reducing the diameter, and a through hole formed in the center of the lowermost end, so that the gasifying agent of the gas is inclined from the peripheral edge toward the through hole. It is a compression injection along the surface.

In this case, since the gasifying agent can be supplied toward the through hole, the thermal efficiency can be improved and the generation of clinker can be suppressed.

(9)
The solid fuel gasifier according to still another aspect is a solid fuel gasifier including a gasifying agent supply unit and a combustion unit for burning the solid fuel, and the combustion unit forms a mortar shape. A surface portion, a hole portion provided in the center of the formed surface portion, and a convex portion provided so as to have a predetermined gap from the end portion forming the hole portion and project from the hole portion to the combustion portion. , And the gasifying agent supply unit supplies the gasifying agent toward the predetermined gap.

In this case, the solid fuel can be held or anchored by the convex portion and the end portion of the forming surface portion, and the gasifying agent can be supplied to efficiently burn the solid fuel. In addition, the ash after combustion can be dropped by gravity from the hole. As a result, it is possible to improve the thermal efficiency and suppress the generation of clinker.

(10)
In the solid fuel gasifier according to the tenth invention, in the solid fuel gasifier according to still another invention, the gasifying agent may be a gas containing oxygen.

In this case, the gasifying agent may be air in the atmosphere or a gas containing oxygen. As a result, the combustion reaction of the solid fuel can be enhanced.

(11)
In the solid fuel gasifier according to the eleventh invention, or in the solid fuel gasifier according to the tenth invention, the supply amount of the gasifying agent is 10 m ³ / h or more and 25 m ³ / h. The following is preferable.

In this case, the optimum combustion reaction can be maintained by supplying the gasifying agent in an amount of 10 m ³ / h or more and 25 m ³ / h or less.

(12)
The solid fuel gasifier according to the twelfth invention is the solid fuel gasifier according to the eleventh invention from another invention, and the gasifier is said before being supplied to the combustion unit. It may pass through a heat transfer section that transfers the heat of the flammable gas generated from the combustion section.

In this case, the combustion efficiency can be improved by transferring the calorific value of the flammable gas to the gasifying agent.

(13)
In the solid fuel gasifier according to the thirteenth invention, and in the solid fuel gasifier according to the twelfth invention from another invention, the ratio of the diameter of the hole to the convex portion is in the range of 2 or more and 3 or less. It is preferably inside.

In this case, since the ratio of the diameter of the hole to the convex is in the range of 2 or more and 3 or less, the combustion reaction can be caused while reliably holding the solid fuel.

(14)
The solid fuel gasifier according to the fourteenth invention is the solid fuel gasifier according to the thirteenth invention from another invention, and the temperature of the solid fuel in the combustion portion is 900 degrees Celsius or more and 1300 degrees Celsius or less. Is preferable.

In this case, since the temperature of the solid fuel in the combustion portion is 900 degrees Celsius or more and 1300 degrees Celsius or less, the water-gas shift reaction can be stably generated.

(15)
The solid fuel gasifier according to the fifteenth invention is the solid fuel gasifier according to the fourteenth invention from another invention, in which the solid fuel is burned before being supplied to the combustion unit. It may pass through a dry part that is dried by the calorific value of the flammable gas generated from the part.

In this case, the amount of water contained in the solid fuel can be evaporated and dried. As a result, a stable combustion reaction can be generated.

(16)
The solid fuel gasification device according to the sixteenth invention may further include a stirring unit for stirring the ash deposits generated in the combustion unit in the solid fuel gasification device according to the fifteenth aspect to the fifteenth aspect. preferable.

In this case, since the ash deposit can be agitated, the flammable gas can be discharged to the outside in a constant and stable manner.

(17)
The solid fuel gasifier according to the seventeenth invention is the solid fuel gasifier according to the sixteenth invention. The stirring unit includes a stirring blade, and the stirring blade has three rotations of 0.1 rotation / minute or more. It is preferable to rotate in the range of / min or less.

In this case, since the stirring unit further includes a stirring blade and rotates in a range of 0.1 rotation / minute or more and 3 rotations / minute or less, the flammable gas is agitated while stirring the accumulated ash without winding up the accumulated ash. Can be discharged.

The present invention relates to a solid fuel gasification device, a power generation device, and a gasification method. In detail, the solid fuel gasification device, a power generation device, and a downdraft type that realizes high thermal efficiency and miniaturization and are less likely to cause clinker. Regarding gasification method.
When gasifying a solid fuel containing carbon such as biomass or coal (hereinafter, may be simply referred to as "solid fuel"), the solid fuel is usually placed at a high temperature of 700 ° C. or higher and in a reducing atmosphere with little oxygen. Is thermally decomposed by reacting with a gasifying agent such as air, oxygen, and water vapor to extract flammable gas (carbon monoxide (CO), hydrogen (H ₂ ), methane (CH ₄ ), etc.).
Types of gasifiers include fixed beds, moving beds, fluidized beds, and jet beds. There are two types of fixed floors: the downdraft type in which the solid fuel and the gasifier flow in the same direction, and the updraft type in which the solid fuel and the gasifying agent flow in the opposite direction.

The downdraft type is a method in which the gasifying agent is flowed from above or from the center to the bottom of the gasifier. First, in the pyrolysis layer (200 ° C or higher and 600 ° C or lower) at the top of the furnace, the solid fuels are methane (CH ₄ ), carbon monoxide (CO), carbon dioxide (CO ₂ ), hydrogen (H ₂ ), and water ( H ₂ O), carbon (C (char (solid))), is pyrolyzed tar, ash content (solid) or the like.

The solid fuel gasifier of the present invention is a solid fuel gasifier that gasifies solid fuel using a downdraft fixed-bed gasifier, in which the lower part of the reactor constituting the gasifier is a peripheral edge. It has an inclined surface that descends from the portion toward the center side in the radial direction while reducing the diameter, and a through hole located at the center of the lowermost end, and a gasifying agent for gas is applied along the inclined surface from the peripheral portion toward the through hole. It is characterized by compression injection.
Another feature is that the gasifying agent is compressed and injected from a plurality of locations on the peripheral edge.
Further, the gasifier is provided with a flow path for the gasifying agent extending in the vertical direction along the outer peripheral surface of the reaction furnace to reach the peripheral portion, and the gasifying agent flows from above to below in the flow path for the gasifying agent. It is characterized by flowing toward the periphery and reaching the peripheral edge.
Further, the gasification furnace is characterized by including a stirring rod extending from the upper part of the reactor through the inside to the upper part of the bottom part.
Further, the gasification furnace is characterized by including a grate arranged below the through hole and a drive mechanism for rotating the grate in a horizontal plane.
Further, the gasification furnace is provided with a flow path for flammable gas that covers the periphery of the flow path for the gasifying agent from the vicinity of the bottom of the reaction furnace to the upper part of the gasification furnace, and the flammable gas is used in the reaction furnace. It is characterized in that it flows from the bottom to the top in the flow path for flammable gas.

The power generation device of the present invention is characterized by including the gasification device, an engine that drives combustible gas generated from the gasification device as at least a part of fuel, and a generator connected to the engine.
The method for gasifying solid fuel of the present invention is a method for gasifying solid fuel using a downdraft type fixed-bed gasifier, in which the lower part of the reactor constituting the gasifier is peripheral. It is equipped with an inclined surface that descends from the portion toward the center side in the radial direction while reducing the diameter, and a through hole formed in the center of the lowermost end, and a gaseous gasifying agent is applied to the inclined surface from the peripheral portion toward the through hole. It is characterized by compression injection along the line.

It is a figure which shows roughly the structure of the power generation apparatus. It is a schematic block diagram which shows an example of the structure of a power generation apparatus. It is a vertical sectional view which shows the internal structure of a gasification apparatus. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 3, showing an inclined surface, a through hole, a nozzle, and the like at the lower part of the reactor. It is a schematic diagram which shows an example of the movement of the amount of heat of the flow path for flammable gas. It is a schematic diagram which shows an example of the structure of a grate. It is a schematic diagram which shows the detail of the combustion part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Moreover, in the case of the same code, their names and functions are also the same. Therefore, the detailed description of them will not be repeated.

(Power generation device 1)
An embodiment of the gasification device 10 and the power generation device 1 of the present invention will be described.
As shown in FIGS. 1 and 2, the power generation device 1 includes a gasification device 10, a tar removal device 20, an ash recovery device 30, a gas mixer 40, an engine 50, and a generator 60.

(Outline of gasifier 10)
In the present embodiment, the gasification furnace 70 of the gasification device 10 can mainly improve the thermal efficiency and suppress the generation of clinker. Details of the gasifier 10 will be described later.

(Tar removal device 20)
The tar removing device 20 in the present embodiment uses a heat exchanger (first heat exchanger). The tar removing device 20 has a mechanism in which tar is positively condensed by cooling a flammable gas with water, and the condensed tar is removed by a scraper. In this case, the cooling is performed to a temperature at which water does not condense.
As the tar removing device 20, a pipe filled with a large number of porous ceramics may be used. Further, the tar removing device 20 is not limited to this, and any tar removing device 20 such as one using a nickel-based (Ni-based) catalyst or one usually used can be used. Then, both the flammable gas and tar are supplied to the next ash recovery device 30.

(Ash recovery device 30)
The ash recovery device 30 uses an automatic cleaning filter. The automatic cleaning filter operates with pressure air generated by an air cylinder. The ash (dust) in the flammable gas is attached to the filter, tar is attached to the dust attached to the filter, and these are scraped off from the filter by automatic cleaning. The removed dust and tar are discharged by the discharger.
As the ash recovery device 30, any ash recovery device 30 such as a commonly used one such as a metal non-woven fabric filter can be used.
That is, the tar removing device 20 and the ash collecting device 30 are devices that mainly remove impurities.
Next, the flammable gas that has passed through the automatic cleaning filter is temperature-controlled by the second heat exchanger and supplied to the gas mixer 40.

(Gas mixer 40)
The gas mixer 40 mixes an appropriate amount of air with a flammable gas and supplies the air-fuel mixture to the engine 50. The gas mixer 40 is provided to mix the flammable gas from which impurities have been removed by passing through the tar removing device 20 and the ash collecting device 30 with the outside air.

(Engine 50 and generator 60)
The engine 50 is driven by the air-fuel mixture supplied from the gas mixer 40. Power is generated by using the generator 60 by the driving force.

The driving or control of various devices such as the gasification device 10, the tar removing device 20, the ash recovery device 30, the gas mixer 40, the engine 50, and the generator 60 constituting the power generation device 1 is automatically controlled by a computer. It may be done manually by the operator.

(Gasifier 10)
Subsequently, the details of the gasification device 10 included in the power generation device 1 will be described.
FIG. 3 is a vertical sectional view showing an example of the internal structure of the gasifier 10.

As shown in FIG. 3, the gasifier 10 mainly includes a fuel supply unit 11, a gasifier supply unit 12, and a gasifier 70.
The gasifier 10 according to the present embodiment is a downdraft type by supplying solid fuel and a gasifier from the fuel supply unit 11 and the gasifier supply unit 12 into the reaction furnace 77 of the gasifier 70. It is a device that thermally decomposes solid fuel to generate flammable gas.

(Fuel supply unit 11)
The fuel supply unit 11 includes a tank for storing solid fuel and a rotary valve (rotary feeder).
The solid fuel stored in the tank is supplied to the gasifier 70 by a rotary valve. Specifically, the rotary valve operates in accordance with the consumption timing of the solid fuel in the gasification furnace 70, and the solid fuel in the tank is quantitatively supplied into the reaction furnace 77. The fuel supply unit 11 is not limited to the above configuration, and any other device or any general device may be used.
Next, the solid fuel will be described.

(Example of solid fuel)
The solid fuel according to the present embodiment includes carbon-containing solid substances such as woody biomass, animal biomass, charcoal, coal (anthracite, bituminous coal, sub-bituminous coal, lignite, sub-coal, peat), briquettes, coal coals, and coke. Can be mentioned.
Examples of the form of woody biomass include pellets, chips, sawdust (including extremely small chips), rice husks, pruned branches, bamboo and the like.
However, woody biomass has variations in composition such as composition or water content, and the variation becomes remarkable in sawdust (including extremely small chips). Therefore, from the viewpoint of stably driving the power generation device 1 for a long period of time, it is preferable to use woody biomass of chips or pellets.
The pellet is generally preferably cylindrical with a diameter of 6 mm or more and 10 mm or less and a length of 10 mm or more and 25 mm or less.
In the present embodiment, even woody biomass with bark can be efficiently burned. Further, the pellet is not limited to a cylindrical shape, and may be a cylindrical shape.

(Gasifying agent supply unit 12)
Next, the gasifying agent supply unit 12 will be described. The gasifying agent supply unit 12 includes a tank 12a for storing the gasifying agent, a blower as a compressor 12b, and a nozzle 12c.
"Compressor" refers to "a machine that pumps gas by the rotational motion of an impeller or rotor or the reciprocating motion of a piston," as defined in JIS B 0132.
Similarly, the “blower” refers to “a compressor having an effective discharge pressure of 200 kPa or less”.
The gasifying agent supplied from the gasifying agent supply unit 12 is compressed and injected into the reaction furnace 77 from the nozzle 12c arranged at the lower part of the reaction furnace 77 through the gasifying agent flow path 72 described later.
The nozzle 12c may be separately provided at the tip of the pipe, or may be an open end of the pipe. In the embodiment shown in FIG. 3, the nozzle 12c is provided in the lower part of the gasifier flow path 72.

(Gasifier 70)
As shown in FIG. 3, the gasification furnace 70 includes a reaction furnace 77, a gasifier flow path 72, a flammable gas flow path 73, a stirring rod 74, a grate 75, and a drive mechanism 76.

(Reactor 77)
The reactor 77 according to the present embodiment is a divergent cylindrical type in which the cross-sectional area in the horizontal plane increases downward. From the viewpoint of suppressing the frictional force generated on the inner wall 71 of the reaction furnace 77, the reaction furnace 77 is preferably circular or elliptical in horizontal cross section.
Further, the larger the inclination of the wall surface of the reactor 77 (inclination angle with respect to the vertical plane), the higher the effect of suppressing the frictional force, but on the other hand, the gas flow in the reactor 77 may be biased, so that it is about 5%. More than 10% is preferable.
The reactor 77 is not limited to a cylindrical shape, and may have an arbitrary shape such as a truncated cone, an inverted truncated cone, a cube, or a rectangular parallelepiped, or may have a rectangular shape in a horizontal cross section. ..

Further, the lower portion of the reactor 77 according to the present embodiment moves vertically downward (lowers) while reducing the diameter from the peripheral edge side to the radial center side of the cylinder of the reactor 77 in the horizontal cross section of the reactor 77. It is provided with an inclined surface 71a and a through hole 71b formed at the center of the lowermost end. That is, the inclined surface 71a forms a side surface having an inverted truncated cone shape.
The reaction furnace 77 is surrounded by an inner wall 71 with a predetermined gap. The circumference of the inner wall 71 is surrounded by the outer wall 78 with a predetermined gap.

(Flower path 72 for gasifying agent)
The flow path 72 for the gasifying agent is formed by extending the gap between the inner walls 71 of the gasifying furnace 70 in the vertical direction along the outer peripheral surface of the reaction furnace 77. One end side of the gasifier flow path 72 is connected to the gasifier supply unit 12. In the embodiment shown in FIG. 3, the upper end of the gasifier flow path 72 is connected to the gasifier supply unit 12 by a pipe.
The other end of the gasifying flow path 72 reaches a plurality of nozzles 12c arranged on the peripheral edge of the bottom of the reactor 77.
The gasifying agent supplied from the gasifying agent supply unit 12 moves from the upper side to the lower side in the gasifying agent flow path 72. The one or more nozzles 12c are formed so that the gasifying agent can be supplied toward the through hole 71b. The gasifying agent is compressed and injected along the inclined surface 71a.
FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3, showing an inclined surface 71a, a through hole 71b, a nozzle 12c, and the like at the lower part of the reactor 77.
Reference numeral 100 in FIGS. 3 and 4 indicates a gasifying agent supplied from the nozzle 12c. The gasifying agent may be compressed and injected from the nozzle 12c. Further, the gasifying agent may be air (atmosphere) or a gas containing oxygen.

(Flower path 73 for flammable gas)
As shown in FIG. 3, the flammable gas flow path 73 is formed so as to cover the periphery of the gasifier flow path 72 from the bottom of the reaction furnace 77 to the upper part of the gasification furnace 70.
Specifically, the gap formed between the inner wall 71 and the outer wall 78 is formed as the flammable gas flow path 73. The flammable gas flow path 73 communicates with the inside of the reactor 77 at the bottom of the reactor 77.

FIG. 5 is a schematic view showing an example of the movement of the amount of heat in the flammable gas flow path 73.
As shown in FIG. 5, a high-temperature flammable gas is generated from the combustion unit 500, which will be described later, in the flammable gas flow path 73. That is, the high-temperature flammable gas flows in the flammable gas flow path 73 from the lower side to the upper side. The gasifier flow path 72 is heated through the inner wall 71 of the flammable gas flow path 73. As a result, the temperature of the gasifying agent that passes through the flow path 72 for the gasifying agent and is supplied from the nozzle 12c to the combustion unit 500 can be raised.
Further, by heating the flow path 72 for the gasifying agent, heat is supplied to the solid fuel side, and the solid fuel supplied to the combustion unit 500 can be brought into a dry state.

(Stirring rod 74)
The stirring rod 74 is a rod-shaped member formed so as to pass from the upper part of the reaction furnace 77 to the upper part of the inclined surface 71a through the inside.
The stirring rod 74 is provided in order to make the thermal decomposition (200 ° C. or higher and 600 ° C. or lower) uniform by stirring the solid fuel in the reaction furnace 77 and to prevent the solid fuel cross-linking phenomenon.
The inside of the stirring rod 74 may be made hollow, and the gasifying agent 100 may be passed through the inside to supply the stirring rod 74 to the vicinity of the inclined surface 71a of the reaction furnace 77.
Further, it may be supplied to the through hole 71b instead of the inclined surface 71a of the reactor 77, or may be compressed and injected toward the through hole 71b.

(Grate 75 and drive mechanism 76)
As shown in FIG. 3, the grate 75 is arranged below the through hole 71b of the reaction furnace 77 to form the bottom portion (furnace bottom) of the reaction furnace 77. Further, the drive mechanism 76 is provided to rotate the grate 75 in the horizontal plane. By rotating the grate 75 by the drive mechanism 76, the solid fuel at the bottom of the reactor 77 can be agitated, the thermal decomposition can be made uniform, and the solid fuel cross-linking phenomenon can be prevented.
As shown in FIG. 3, in the present embodiment, the grate 75 is formed through the through hole 71b formed in the inclined surface 71a. That is, a part of the grate 75 is provided so as to penetrate the through hole 71b from the vertically downward direction to the vertically upward direction.

Further, FIG. 6 is a schematic view showing another example of the grate 75, and FIG. 7 is a schematic view showing details of the combustion unit 500.

Further, as shown in FIG. 6, the grate 75 may have one or more blade members 75c extending into the flammable gas flow path 73.
The blade member 75c is provided at the peripheral end of the grate 75. For example, the drive mechanism 76 rotates the grate 75 within a range of 0.1 rotation / min or more and 3 rotations or less / min at a constant, concise, fluctuating speed, etc., or a combination thereof. May be good.
More preferably, the drive mechanism 76 may rotate the grate 75 at 0.5 rpm. The drive mechanism 76 does not necessarily have to rotate the grate 75, and may be moved in the vertical direction or may be vibrated.
Further, it is preferable that the blade member 75c has a function of stirring the ash accumulated in the flammable gas flow path 73. As a result, the flammable gas generated in the combustion unit 500 can be stably supplied to the tar removing device 20 on the downstream side.

Next, as shown in FIG. 7, a part 75a of the grate 75 is provided so as to form a predetermined gap (horizontal distance 71L-75L, vertical distance 75H) with the inclined surface 71a and the through hole 71b. In the present embodiment, the predetermined gap is set within the range of equal to or more than twice the length of the solid fuel.

(Explanation of the combustion part in the reactor 77)
Next, the operation of the reactor 77 will be described.
First, solid fuel is charged into the tank of the fuel supply unit 11, and the rotary valve is driven to deposit the solid fuel up to a predetermined height in the reactor 77.
Next, the solid fuel in the ignited reaction furnace 77 comes into contact with the inclined surface 71a at the lower part of the reaction furnace 77 through the gasifier flow path 72. Immediately after ignition, a small amount of the gasifying agent is supplied, and when a predetermined time elapses after ignition, supply of a specified amount is started.

Next, the solid fuel tries to move downward from the inclined surface 71a through the through hole 71b. In this case, the solid fuel is in a state where it is difficult to pass through the gap formed by the through hole 71b and a part of the grate 75.
That is, as shown in FIG. 7, in the combustion unit 500, the pellets are held or anchored between a part 75a of the grate 75 and the inclined surface 71a for a predetermined time to generate a combustion state, and a combustion layer is generated. Is formed.
In particular, in the present embodiment, since the gasifying agent is supplied from the nozzle 12c in the direction of arrow 100, the combustion layer is maintained in an ultra-high temperature range of 900 ° C. or higher and 1300 ° C. or lower. That is, a water-gas shift reaction or the like occurs in the combustion unit 500.

The gasifying agent 100 does not have to be compression-injected, and may be compressed-injected. The merit of compression injection is that the ash on the inclined surface 71a can be blown off. Further, the merit of compression injection is that the gasifying agent can be supplied to the gap of the solid fuel.
In these cases, the solid fuel is oxidized, and a reaction layer by high-efficiency combustion is constructed around a part of the grate 75 and the through hole 71b. As a result, the production of flammable gas is started.

A reducing layer is formed near the lower part of the grate 75 and the through hole 71b, and the flammable gas generated from the reducing layer (600 ° C. or higher and 800 ° C. or lower) rises in the flammable gas flow path 73. Then, it is taken out to the outside of the gasifier 70.
The flammable gas flows upward from below the reactor 77 through the flammable gas flow path 73. In this case, one or a plurality of blade members 75c provided on the grate 75 agitate the ash accumulated in the flammable gas flow path 73.
As a result, the flammable gas is stably flowed upward from below the reactor 77 through the flammable gas flow path 73, taken out from the upper end to the outside of the gasification furnace 70, and the tar removing device 20 downstream. Etc. can be moved.

Further, the heat of the flammable gas rising in the flammable gas flow path 73 is transferred to the gasifying agent flowing in the gasifying agent flow path 72 through the inner wall 71, so that the gasifying agent is in a high temperature state. It is possible to perform compression injection by changing the gas to, and it is possible to prevent a temperature drop in the reactor 77.
Further, by partially oxidizing the solid fuel sequentially supplied from the fuel supply unit 11 in the reactor 77, the dry layer, the pyrolysis layer (200 ° C. or higher and 600 ° C. or lower), and the combustion layer (600 ° C. or higher and 1300 ° C. or lower) are sequentially oxidized from the top. The following) can be formed.

In the present invention, the gaseous gasifying agent is compressed and injected along the inclined surface 71a toward the through hole 71b at the bottom of the reactor 77. As described above, in the conventional gasifier 70, the ash in the furnace (particularly the bottom of the furnace and its surroundings) is often solidified to form a clinker during the heat treatment, but in the present invention, the gasifying agent is compressed and injected. By doing so, the ash on the inclined surface 71a is blown off, so that the clinker is less likely to be formed.
Further, the gasifying agent is compressed and injected toward the through hole 71b of the inclined surface 71a, and only the solid fuel existing in the vicinity of the through hole 71b is intensively heated to an ultra-high temperature and passed through the through hole 71b, so that the thermal efficiency can be improved. It has the effect of being able to do it.
Further, by injecting the gasifying agent by compression, the gas is not only in the range where the density of the solid fuel is low, that is, the range where the gap between the solid fuels is large, but also in the range where the density is high, that is, the range where the gap between the solid fuels is small. Since the agent can be sent in, the thermal efficiency can be further improved.
If the gasifying agent is compression-injected from a plurality of locations, it is more difficult for clinker to be formed, and the thermal efficiency can be further improved.

Further, if the gasifying agent flow path 72 extending in the vertical direction is provided along the outer peripheral surface of the reaction furnace 77 and the gasifying agent is allowed to flow in the gasifying agent flow path 72, the heat of the reactor 77 is generated. Is transmitted to the gasifying agent, so that the high-temperature gasifying agent can be compressed and injected, and the temperature drop in the reactor 77 can be prevented.
Further, if the solid fuel in the reaction furnace 77 is agitated by the stirring rod 74, the thermal decomposition can be made uniform and the cross-linking phenomenon of the solid fuel can be prevented.
Further, if the grate 75 arranged below the through hole 71b is rotated in the horizontal plane, ash is less likely to accumulate on the surface of the grate 75, so that the formation of clinker can be prevented.

Further, if the flammable gas flow path 73 that covers the periphery of the gasifier flow path 72 and reaches the upper part of the gasification furnace 70 is provided, the heat of the high-temperature combustible gas flows to the gasifier flow. Since it is transmitted to the gasifying agent in the path 72, the gasifying agent 100 can be compressed and injected at a high temperature.
As described above, in the present invention, the tar concentration in the flammable gas can be made extremely low by making the vicinity of the through hole 71b at the lower part of the reaction furnace 77 extremely high, so that the tar removal provided downstream of the gasification device 10 can be performed. The burden on the device 20 or the ash recovery device 30 can be reduced, and the engine 50 can be stably driven for a long period of time.

In the present invention, the gasifier 10 corresponds to the "gasifier", the gasifier 70 corresponds to the "gasifier", the reactor 77 corresponds to the "reactor", and the inclined surface. 71a corresponds to "inclined surface, forming surface portion", through hole 71b corresponds to "through hole, hole portion", and nozzle 12c corresponds to "multiple locations, gasifying agent supply portion" and is gasified. The agent flow path 72 corresponds to the "gasifier flow path", the stirring rod 74 corresponds to the "stirring rod", the grate 75 corresponds to the "grate", and the drive mechanism 76 Corresponding to the "drive mechanism", the combustible gas flow path 73 corresponds to the "combustible gas flow path", the engine 50 corresponds to the "engine", and the generator 60 becomes the "generator". The power generator 1 corresponds to the "power generator", the combustion unit 500 corresponds to the "combustion unit", a part 75a of the grate 75 corresponds to the "convex portion", and the inner wall 71 corresponds to the "calorific value". The inside of the reaction furnace 77 corresponds to the "drying part", and one or more blade members 75c correspond to the "stirring part, stirring blade".

A preferred embodiment of the present invention is as described above, but the present invention is not limited thereto. It will be appreciated that various embodiments are made that do not deviate from the spiritual scope of the present invention. Further, in the present embodiment, the actions and effects according to the constitution of the present invention are described, but these actions and effects are examples and do not limit the present invention.

1 Power generator 10 Gasifier 11 Fuel supply unit 12 Gasifier supply unit 12a Tank 12b Compressor 12c Nozzle 20 Tar removal device 30 Ash recovery device 40 Gas mixer 50 Engine 60 Generator 70 Gasifier 71 Inner wall 71a Inclined surface 71b Through hole 72 Gasifier flow path 73 Combustible gas flow path 74 Stirring rod 75 Grate 75a Part of grate 75c Blade member 76 Drive mechanism 77 Reaction furnace 78 Outer wall 100 Gasifier 500 Combustion unit

Claims (17)

In a solid fuel gasifier that gasifies solid fuel using a downdraft fixed-bed gasifier
The lower part of the reactor constituting the gasification furnace is provided with an inclined surface that descends from the peripheral portion toward the center side in the radial direction while reducing the diameter, and a through hole located at the center of the lowermost end.
A solid fuel gasification device for compressing and injecting a gaseous gasifying agent from the peripheral portion toward the through hole along the inclined surface. The solid fuel gasification device according to claim 1, wherein the gasifying agent is compressed and injected from a plurality of locations on the peripheral portion. The gasification furnace includes a flow path for a gasifying agent that extends in the vertical direction along the outer peripheral surface of the reaction furnace and reaches the peripheral edge portion, and the gasifying agent flows through the flow path for the gasifying agent. The solid fuel gasification device according to claim 1 or 2, wherein the gas flows from the upper side to the lower side to reach the peripheral portion. The gasification of a solid fuel according to any one of claims 1 to 3, wherein the gasification furnace includes a stirring rod extending from the upper part of the reaction furnace through the inside to the upper part of the bottom part. apparatus. The present invention according to any one of claims 1 to 4, wherein the gasification furnace includes a grate arranged below the through hole and a drive mechanism for rotating the grate in a horizontal plane. The solid fuel gasifier described. The gasification furnace includes a flow path for flammable gas that covers the periphery of the flow path for the gasifying agent from the vicinity of the bottom of the reaction furnace to the upper part of the gasification furnace, and the combustible gas. The solid fuel gasification apparatus according to any one of claims 1 to 5, wherein the gas flows from below the reactor to the inside of the combustible gas flow path from below to above. A gasifier according to any one of claims 1 to 6, an engine that drives a flammable gas generated from the gasifier as at least a part of fuel, and a generator connected to the engine. A power generator characterized by being provided. In the method of gasifying solid fuel using a downdraft fixed-bed gasifier to gasify solid fuel.
The lower part of the reactor constituting the gasification furnace is provided with an inclined surface that descends from the peripheral edge portion toward the center side in the radial direction while reducing the diameter, and a through hole formed at the center of the lowermost end.
A method for gasifying a solid fuel, which comprises compressing and injecting a gaseous gasifying agent from the peripheral portion toward the through hole along the inclined surface. Gasifier supply unit and
A solid fuel gasifier that includes a combustion unit that burns solid fuel.
The combustion part is
The mortar-shaped forming surface and
A hole provided in the center of the forming surface portion and
It includes a convex portion having a predetermined gap from the end portion forming the hole portion and being provided so as to project from the hole portion to the combustion portion.
The gasifying agent supply unit is a solid fuel gasifying device that supplies a gasifying agent toward the predetermined gap. The gasifier for a solid fuel according to claim 9, wherein the gasifying agent is a gas containing oxygen. The solid fuel gasifier according to claim 9 or 10, wherein the supply amount of the gasifying agent is 10 m ³ / h or more and 25 m ³ / h or less. The gasifying agent according to any one of claims 9 to 11, wherein the gasifying agent passes through a heat transfer unit that transfers the heat amount of the flammable gas generated from the combustion unit before being supplied to the combustion unit. Solid fuel gasifier. The solid fuel gasifier according to any one of claims 9 to 12, wherein the ratio of the diameter of the hole to the convex is in the range of 2 or more and 3 or less. The solid fuel gasifier according to any one of claims 9 to 13, wherein the temperature of the solid fuel in the combustion unit is 900 degrees Celsius or more and 1300 degrees Celsius or less. The solid according to any one of claims 9 to 14, wherein the solid fuel passes through a dry portion that is dried by the calorific value of the flammable gas generated from the combustion portion before being supplied to the combustion portion. Fuel gasifier. The solid fuel gasification apparatus according to any one of claims 1 to 15, further comprising a stirring unit for stirring the ash deposits generated in the combustion unit. The stirring unit includes a stirring blade.
The solid fuel gasification device according to claim 16, wherein the stirring blade rotates in a range of 0.1 rotation / minute or more and 3 rotations / minute or less.