JP5595132B2 - Biomass storage device - Google Patents

Description

  The present invention relates to a biomass storage device that stores biomass, and more particularly, to a biomass storage device that enables humidity management inside a storage tank that is affected by moisture held by biomass.

In recent years, the diversification of fuels has rapidly progressed in industrial thermal power plants and the like, and facilities that use biomass as one of the fuels are increasing in addition to the fossil fuels that have been widely used. Biomass is promoted because it contributes to CO ₂ emission control and is a non-depleting resource, and in response to this, various plant facilities switch from fossil fuels such as coal to biomass, Or other fuels and biomass co-firing.

For example, in a facility that co-fires biomass and other fuels such as coal, the brought-in biomass is temporarily stored in a storage tank, mixed with other fuels at a preset ratio, and supplied to the combustion furnace. .
As the fuel storage tank used in such facilities, a storage tank specialized for biomass has been rarely used, and a storage tank for other solid fuel such as coal has been used in many cases. The general structure has a fuel inlet at the top and a fuel outlet that cuts out and discharges a predetermined amount of fuel at the bottom, and the fuel discharged from the fuel outlet is transport means such as a belt conveyor. Thus, the fuel is transported to the load side where the fuel is used.

  Here, as a biomass storage tank, Patent Document 1 (Utility Model Registration No. 3123376) discloses a configuration of a storage tank for a beverage extractor. This storage tank prevents the beverage extraction basket from being compressed and solidified by an agitating part, a compressed air blow nozzle or the like provided in the tank, and enables the beverage extraction basket to be smoothly discharged. Further, Patent Document 2 (Japanese Patent No. 4402243) discloses a configuration of a supply device in which a stirrer and a screw feeder are provided in a storage tank so that particulate matter such as biomass is supplied uniformly and continuously. ing.

Utility Model Registration No. 3123376 Japanese Patent No. 4402243

However, biomass has a higher moisture content than fossil fuels such as coal, and this has conventionally caused problems peculiar to biomass in fuel storage devices.
For example, bark, which is often used for biomass, has an average water content of about 20-30% by weight, and the water content of bark is about 20% by weight in the upper part of the storage tank, but about 50% by weight in the lower part. Become. From this, it is considered that the dripping of water occurs in the storage tank due to the following phenomenon.

First, the moisture of the biomass in the storage tank evaporates, and is cooled at the ceiling or side wall of the storage tank and dewed to become water again, and moves to the bottom through the inner wall of the storage tank. And the water which moved to the bottom part of a storage tank is discharged | emitted from a storage tank as it is, or the biomass of a bottom part once absorbs, is squeezed out by the dead weight of biomass, and is discharged | emitted from a storage tank.
In this way, there is a problem that the moisture held by the biomass hangs down from the storage tank and causes corrosion of the conveyor rail portion, thereby damaging the conveyor.

In general solid fuel storage tanks, solid fuel with a high water content is not assumed, and the conventional biomass storage tanks disclosed in Patent Document 1 and Patent Document 2 also solve the above-mentioned problems. No measures are taken.
Therefore, in order to eliminate problems such as corrosion of storage tank peripheral equipment such as a conveyor due to moisture held by biomass, it is required to establish humidity management inside the storage tank and a technology associated therewith.

  An object of the present invention is to provide a biomass storage device capable of preventing problems such as corrosion in a storage tank peripheral device due to the influence of moisture held by biomass.

In order to solve the above problems, the biomass storage device according to the present invention is:
In a biomass storage apparatus having a storage tank for storing biomass and a transport means for transporting the biomass cut out from the bottom of the storage tank,
An opening provided in the side wall of the storage tank, the piping which the open port biomass connecting the load to be supplied, is provided on the pipe, suction means to pull the air inside the reservoir through the opening When connected to the suction side of the pipe of the suction means, the branch pipe to join the extraction air from the reservoir draws dilution air from outside the tank, provided on the branch pipe, the supply of the dilution air A dilution air amount adjusting means for adjusting the amount, and a humidity detecting means for detecting the humidity of the drawn air or the combined air of the drawn air and the diluted air is provided on the pipe, and a detection output from the humidity detecting means Based on the above, the dilution air amount adjusting means is controlled to set a humidity range in which the combined air does not condense on the pipe from the connecting portion of the branch pipe to the load .

According to this invention, since it is set as the structure which draws out the air in a storage tank from opening of a side wall, the inside of a storage tank can be kept below saturated vapor pressure. Therefore, it is possible to prevent condensation in the storage tank due to moisture evaporated from the biomass, and it is possible to prevent problems such as corrosion, wear, and breakage of peripheral equipment of the storage tank such as a transport means because no dripping of water from the storage tank occurs. .
At this time, since the extraction air from the opening is high in humidity, it is considered that the piping through which the extraction air passes and the suction means, etc., may condense and cause problems, but in the present invention the diluted air is extracted upstream from the suction means. Since the humidity is lowered by joining the pipes, it is possible to prevent dew condensation of equipment such as piping and suction means downstream of the branch pipe. The diluted air is air having a lower humidity than the drawn air in the tank, and is preferably outside air.

Further, the load supplied with the biomass from the storage tank is a combustion furnace, the pipe is connected to the combustion furnace, and the combined air of the extraction air and the dilution air is used as at least a part of the combustion air It is preferable to use it.
This is because the storage tank contains soot of biomass and a small amount of odor components, but by putting extracted air containing these into the combustion furnace together with dilution air, the soot and odor components can be burned and rendered harmless. . Therefore, it is not necessary to newly install an air purification device or the like for treating the drawn air, and an increase in cost can be prevented.

Furthermore, it is preferable to provide dilution air amount adjusting means for adjusting the supply amount of the dilution air on the branch pipe. This dilution air amount adjusting means may be manual control or automatic control.
In general, biomass does not have a constant moisture content, which may cause the humidity of the drawn air to fluctuate and the temperature of the drawn air or diluted air to fluctuate. By providing, it becomes possible to adjust the supply amount of dilution air in response to the above-described condition fluctuations, and it is possible to reliably prevent the combined air from condensing on the pipe.

Furthermore, humidity detection means for detecting the humidity of the extracted air or the combined air of the extracted air and the diluted air is provided so that the combined air falls within a humidity range based on the humidity detected by the humidity detecting means. It is preferable to control the dilution air amount adjusting means.
In addition, the humidity range where condensed air does not condense means the humidity range where condensed air does not condense on piping from the connection part of a branch pipe to load.
In this way, by adopting a configuration in which the dilution air amount adjusting means is controlled based on the humidity detected by the humidity detecting means, the dilution air amount adjusting means can be controlled with high accuracy, and the combined air can be more condensed on the pipe. It can be surely prevented.

Moreover, it is preferable to provide a plate-like biomass outflow prevention means having an air passage portion and inclined downward toward the inside of the tank at the opening of the storage tank.
Thus, by providing the biomass outflow prevention means, it is possible to suck only the air in the storage tank mainly from the opening and prevent the biomass from flowing out of the tank from the opening. Further, since this biomass outflow prevention means has a plate-like configuration inclined downward toward the inside of the tank, even when condensed water is generated inside the storage tank, the condensed water is transmitted from the side wall to the biomass outflow prevention means. Therefore, the water does not flow out of the storage tank, and it is possible to prevent the occurrence of problems due to the outflow water of the storage tank peripheral equipment.

  In addition to the above-described configuration, it is preferable that the inclination angle of the biomass outflow prevention means is set to an angle exceeding the repose angle of the biomass, thereby preventing biomass from being deposited on the biomass outflow prevention means. .

Further, it is preferable that a casing for forming a buffer space is provided outside the side wall of the storage tank so as to surround the opening, and the piping is connected to the casing.
Thus, by providing the buffer space between the opening and the pipe, it is possible to prevent the pipe from being blocked due to staying in the buffer space even when biomass flows out from the opening.

  As described above, according to the present invention, since the air in the storage tank is drawn out from the opening of the side wall, condensation in the storage tank due to water evaporated from the biomass can be prevented, and dripping of water from the storage tank occurs. Therefore, it is possible to prevent problems such as corrosion, wear, and damage on the storage tank peripheral equipment, and to reduce the humidity by joining diluted air to the extraction air from the storage tank. Condensation can be prevented.

It is a basic lineblock diagram of a biomass storage device concerning an embodiment of the present invention. It is a figure explaining the opening degree control of a damper. It is the figure which expanded the opening vicinity of the storage tank, (A) is a sectional side view, (B) is XX sectional drawing of (A). It is a figure explaining a biomass outflow prevention means. It is a figure which shows the other structural example of a biomass outflow prevention means, (A) is a sectional side view, (B-1) is a Y direction arrow view (other structural example 1) of (A), (B -2) is a view in the Y direction (another configuration example 2). 1 is an example of an embodiment of the present invention, and is an overall configuration diagram of a thermal power plant.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

With reference to FIG. 1, the basic composition of the biomass storage apparatus which concerns on embodiment of this invention is demonstrated.
The main configuration of the biomass storage apparatus includes a storage tank 1 that stores biomass and a transport conveyor 10 that transports biomass from the storage tank 1 to the load side, and from an opening 5 provided on the side wall of the storage tank 1 to the load side. The pipe 11 extends, a small fan 12 provided on the pipe 11, and a branch pipe 21 connected to the pipe 11 on the suction side of the small fan 12.
Biomass refers to a bio-derived resource created by photosynthesis that can be used for energy, and in this embodiment, in particular, woody biomass such as bark, thinned wood, construction waste, and remaining lumber is of a predetermined size. It is preferable that the material is crushed to a thickness below.

  The storage tank 1 has a fuel inlet 3 at the top of the tank body 2, a fuel discharge part 4 at the bottom, and an opening 5 in the side wall. The tank body 2 is a sealed type in order to prevent dust and odor components generated from biomass from being scattered. The fuel input port 3 can be opened and closed, and biomass is appropriately input from here. The fuel discharge unit 4 is configured to cut out and discharge a predetermined amount of biomass in the tank, and has a cut-out amount adjusting means and a discharge port. As the cut-out amount adjusting means, for example, a turning screw reclaimer as shown in FIG. 1 or a screw feeder as disclosed in Patent Document 2 can be used. The opening 5 is provided in the side wall of the tank body 2, and more preferably in the lower part of the side wall of the tank body 2. The shape of the opening 5 may be square or circular. Further, only one opening 5 may be provided for the tank body 2 or a plurality of openings 5 may be provided in the circumferential direction. In addition, in FIG. 1, the case where only one opening 5 is provided in the tank main body 2 is shown as an example.

The conveyor 10 is provided in the vicinity of the fuel discharge part 4 of the storage tank 1, and conveys the biomass discharged from the fuel discharge part 4 to the load side. For example, a belt conveyor is used as the conveyor 10.
Here, the load in the present embodiment is a device that generates energy using biomass as at least a part of the raw material, for example, a combustion furnace, a biological treatment device, a bioethanol production device, etc. It is good that it is a combustion furnace (including dry distillation and carbonization furnace) using woody biomass as at least a part of fuel.

One end of the pipe 11 is connected to the opening 5 of the storage tank 1 and the other end is connected to a load. A small fan 12 is provided on the pipe 11 as a suction means for extracting the air in the storage tank 1 through the opening 5 and guides the extracted air extracted from the tank to the load. The small fan is continuously or appropriately intermittently operated so that the inside of the storage tank 1 is maintained below the saturated vapor pressure.
Further, a branch pipe 21 is connected to the pipe 11 on the suction side of the small fan 12, that is, the pipe 11 between the opening 5 and the small fan 12, and draws dilution air from the outside of the tank and joins the drawn air from the storage tank. It is supposed to let you. The diluted air is air having a lower humidity than the drawn air in the tank, and is preferably outside air.

Thus, according to this embodiment, since it is set as the structure which draws out the air in the storage tank 1 from the opening 5 of a side wall, the inside of the storage tank 1 can be kept below saturated vapor pressure. Therefore, dew condensation in the storage tank 1 due to moisture evaporated from the biomass can be prevented, and no dripping of water from the storage tank 1 occurs, so that problems such as corrosion, wear, and damage of peripheral equipment of the storage tank such as the conveyor 10 Can be prevented.
At this time, since the extraction air from the opening 5 is high in humidity, it is considered that the piping 11 through which the extraction air passes, the small fan 12, etc. may condense and cause problems, but in the present embodiment, on the upstream side of the small fan 12. Since the dilution air is merged with the drawn air to reduce the humidity, it is possible to prevent dew condensation on equipment such as the pipe 11 and the small fan 12 on the downstream side of the branch pipe 21.

Further, Oite to the present embodiment, on the branch pipe 21, provided with a damper 22 as dilution air amount adjusting means for adjusting the supply amount of dilution air. The damper 22 may be manually controlled or automatically controlled.
In general, the amount of moisture held in biomass is not constant, which may cause the humidity of the drawn air to fluctuate and the temperature of the drawn air or diluted air to fluctuate. However, by providing the damper 22 as in this configuration, In addition, it becomes possible to adjust the supply amount of the dilution air in response to the above-described condition variation, and it is possible to reliably prevent the merging air from condensing on the pipe 11.

Furthermore, the Te embodiment smell, the humidity detecting means 23 for detecting the humidity of the confluent air in the dilution air and drawing air or drawing air provided, based on the humidity detected by the humidity detecting means 23, confluent air condensing The damper 22 is controlled so that the humidity range is not exceeded. In addition, the humidity range where condensed air does not condense means the humidity range where condensed air does not condense on the piping 11 from the connection part of the branch pipe 21 to a load.

  In FIG. 1, as a preferred configuration example, the humidity detecting means 23 is provided downstream of the small fan 12 so as to detect the humidity of the combined air. By detecting the humidity of the merged air after merging in this way, it can also be confirmed that the humidity range where the merging air is not condensed is obtained. In addition to the humidity detecting means, temperature detecting means (not shown) for detecting the temperature of the combined air or the temperatures of the drawn air and the diluted air may be provided. Based on the air temperature detected by the temperature detecting means. It is preferable to calculate an accurate humidity range in which the combined air does not condense in the pipe 11. In addition to this, temperature detection means for detecting the temperature of the merging air in the vicinity of the load is provided, the temperature of the merging air that is most likely to condense due to temperature drop is detected, and an accurate humidity range in which the merging air does not condense is calculated. Is more preferable. The damper 22 is controlled to adjust the supply amount of dilution air so that the humidity range obtained in this way is obtained.

  However, the present invention is not limited to this configuration, and the humidity detecting means 23 may be provided between the opening 5 and the connecting portion of the branch pipe 21. In this case, the mixing ratio of the drawn air and the diluted air is calculated based on the respective humidity and temperature of the drawn air and the diluted air, and the supply amount of the diluted air is adjusted by the damper 22. For example, the extracted air has a temperature of 30 ° C. (relative humidity 100%), the diluted air has a temperature of 15 ° C. (relative humidity 50%), and the merged air after merging reaches 15 ° C. (similar to the diluted air) downstream of the pipe 11. When the temperature decreases, the dilution air may be mixed at about 3 times or more of the extraction air.

  Thus, by setting it as the structure which controls the damper 22 based on the humidity detected by the humidity detection means 23, the damper 22 can be controlled with a sufficient precision and it can prevent more reliably that condensed air condenses on the piping 11. FIG. .

Here, a specific control method of the damper 22 will be described with reference to FIG.
When the humidity of the merged air is detected by the humidity detecting means 23 (see FIG. 1), the damper 22 is controlled to a constant reference opening until the humidity of the merged air reaches a preset humidity H1. This humidity H1 is an upper limit value of the humidity at which the combined air does not condense even at the end of the pipe 11 (load side). This upper limit value includes a safety range due to an error or the like.
On the other hand, when the humidity of the combined air becomes equal to or higher than the humidity H1, control is performed to open the opening of the damper 22 in proportion to the detected humidity.
As described above, the damper 22 is controlled by performing the two-stage control in which the damper 22 is maintained at the reference opening when the humidity is equal to or lower than the humidity H1, and the damper 22 is controlled to be opened when the humidity is equal to or higher than the humidity H1. Can be easily prevented and condensation can be reliably prevented.

Moreover, it is preferable that the biomass storage apparatus which concerns on this embodiment provides the biomass outflow prevention means 6 in the opening 5 of the storage tank 1, as shown in FIG. 3 thru | or FIG.
The biomass outflow prevention means 6 has an air passage portion 7 through which air passes and is formed in a plate shape inclined downward toward the inside of the storage tank. The biomass outflow prevention means 6 is configured to allow only air to pass mainly from the air passage portion 7, and prevents the biomass from being caught in the air and flowing out of the tank. Furthermore, since the biomass outflow prevention means 6 is formed in a plate shape inclined downward toward the inside of the storage tank, even when condensed water is generated in the tank, the condensed water is prevented from flowing out from the side wall by the biomass outflow prevention means. It flows down to the inside of the tank through 6. Therefore, moisture does not flow out to the outside of the storage tank, and it is possible to prevent the occurrence of problems due to the outflow moisture of the storage tank peripheral equipment.

With reference to FIG. 3, the specific structural example of the biomass outflow prevention means 6 is demonstrated. Here, FIG. 3 is an enlarged view of the vicinity of the opening of the storage tank, (A) is a side sectional view, and (B) is an XX sectional view of (A).
The biomass outflow means 6 has a configuration in which long plate members 6a that are stretched horizontally in the opening 5 are arranged in multiple stages in the vertical direction. A gap is formed between the plate members 6 a, and this gap serves as an air passage portion 7. The plate member 6a is installed to be inclined downward toward the inside of the storage tank.

FIG. 4 is a diagram for explaining the biomass outflow means shown in FIG. 3 in detail.
As shown in the figure, the inclination angle θ1 of the plate member 6a with respect to the horizontal plane is preferably set to an angle exceeding the repose angle of biomass. Thereby, it is possible to prevent biomass from being deposited on the plate member 6a.
The biomass outflow means 6 is preferably designed to satisfy the following conditions in order to prevent the outflow of biomass from the air passage portion 7.
The distance d between the surfaces of the two adjacent plate members 6a is set to be less than the particle size of biomass, or the angle formed by the surface connecting the upper end of the plate member 6a and the lower end of the plate member 6a adjacent thereto and the horizontal plane θ2 is set to be less than the angle of repose of biomass. By designing the biomass outflow means 6 so as to satisfy at least one of these, preferably both conditions, the outflow of biomass from the air passage portion 7 can be reliably prevented.
Furthermore, since the plate member 6a is installed to be inclined downward toward the inside of the storage tank, it is possible to prevent moisture from flowing out of the tank.

Further, as shown in FIG. 3, a casing 8 that forms a buffer space 9 may be provided outside the side wall of the storage tank 1 so as to surround the opening 5, and a pipe 11 may be connected to the casing 8. Thus, by providing the buffer space 9 between the opening 5 and the pipe 11, even when biomass flows out from the opening 5, it remains in the buffer space 9 and can prevent the pipe 11 from being blocked.
At this time, it is preferable that the casing 8 is provided with a freely openable / closable cleaning port 8a so that it can be removed when the air passage 7 is clogged with biomass dust or the like.

FIG. 5 is a diagram showing another configuration example of biomass outflow prevention means, (A) is a side sectional view, and (B-1) is a view in the Y direction of (A) (another configuration example 1). (B-2) is a view in the Y direction (another configuration example 2).
As shown in FIG. 5 (A), this biomass outflow prevention means 6 is formed in a single plate shape arranged so as to cover the entire surface of the opening 5.

Furthermore, as shown in another configuration example 1 of FIG. 5B-1, the biomass outflow prevention means 6 may be formed in a comb shape in which comb teeth are arranged in the vertical direction. In this case, the gap between the comb teeth becomes the air passage portion 7. The comb teeth are arranged so as to incline downward toward the inside of the storage tank, and moisture flows down into the tank through the comb teeth.
Furthermore, as shown in another configuration example 2 of FIG. 5 (B-2), the biomass outflow prevention means 6 may have a configuration in which a mesh is fitted in a frame shape. In this case, the mesh becomes the air passage portion 7. The frame mold and the mesh are arranged so as to be inclined downward toward the inside of the storage tank, and moisture flows down into the tank through the frame mold or the mesh.

Next, an example of a plant to which the biomass storage apparatus of the present embodiment is applied will be described with reference to FIG. FIG. 6 is an overall configuration diagram of the thermal power plant. In addition, since it has already demonstrated about the detailed structure of the biomass storage apparatus, it abbreviate | omits.
The thermal power plant mainly includes a biomass storage device, a combustion furnace 30, an exhaust gas treatment device including a filter 33, an induction blower 34, and a chimney 35.

Although the combustion furnace 30 has illustrated the fluidized bed boiler as an example, the kind of the combustion furnace 30 is not limited to this. The biomass cut out from the storage tank 1 of the biomass storage device is transported by the transport conveyor 10, mixed with other fuels, and charged into the combustion furnace 30.
A pipe 11 extending from the opening 5 of the storage tank 1 is connected to the bottom of the combustion furnace 30, and the branch pipe 21 and the small fan 12 are provided on the pipe 11 as described above. Further, a pusher blower 15 is provided on the pipe 11 on the downstream side of the small fan 12, and a branch pipe 25 that draws main air of combustion air is connected to the pipe 11 on the suction side.

  With this configuration, the extracted air extracted from the storage tank 1 is mixed with the diluted air, and further mixed with the main air, and then introduced into the furnace from the bottom of the combustion furnace 30 to be used as combustion air. Here, the case where the combined air is used as the main combustion air is shown, but the combined air can be supplied to the upper space of the combustion furnace 30 and used as the secondary combustion air.

  As described above, since the branch pipe 25 and the pusher blower 15 for drawing the main air of the combustion air are provided on the downstream side of the small fan 12, the overall piping structure can be reduced in size. Moreover, since the extraction air from the storage tank 1 is input into the combustion furnace 30 together with the dilution air and the main air, the dust and odor components contained in the extraction air can be burned and rendered harmless. Therefore, it is not necessary to newly install an air purification device or the like for treating the drawn air, and an increase in cost can be prevented.

DESCRIPTION OF SYMBOLS 1 Storage tank 2 Tank main body 5 Opening 6 Biomass outflow prevention means 6a Plate member 7 Air passage part 8 Casing 8a Cleaning port 9 Buffer space 10 Conveyor 11 Pipe 12 Small fan 15 Push-in fan 21, 25 Branch pipe 22 Damper 23 Humidity detection means 30 Combustion furnace

Claims (6)

In a biomass storage apparatus having a storage tank for storing biomass and a transport means for transporting the biomass cut out from the bottom of the storage tank,
An opening provided in the side wall of the storage tank, the piping which the open port biomass connecting the load to be supplied, is provided on the pipe, suction means to pull the air inside the reservoir through the opening When connected to the suction side of the pipe of the suction means, the branch pipe to join the extraction air from the reservoir draws dilution air from outside the tank, provided on the branch pipe, the supply of the dilution air A dilution air amount adjusting means for adjusting the amount, and a humidity detecting means for detecting the humidity of the drawn air or the combined air of the drawn air and the diluted air is provided on the pipe, and a detection output from the humidity detecting means A biomass storage device characterized in that the dilution air amount adjusting means is controlled based on the above and is set to a humidity range in which the merging air does not condense on the piping from the connecting portion of the branch pipe to the load . The load supplied with the biomass from the storage tank is a combustion furnace,
The biomass storage device according to claim 1, wherein the piping is connected to the combustion furnace, and the combined air of the extraction air and the dilution air is used as at least a part of the combustion air. The biomass storage device according to claim 1 or 2, wherein a humidity detection means is provided downstream of the suction means to detect the humidity of the combined air on the pipe from the branch pipe connection portion to the load. . Wherein the opening of the reservoir has an air passage section, biomass storage device according to claim 1, characterized in that a plate-like biomass outflow preventing section which is inclined downward toward the inside the tank. The biomass storage device according to claim 4 , wherein an inclination angle of the biomass outflow prevention means is set to an angle exceeding an angle of repose of the biomass. The biomass according to any one of claims 1 to 5 , wherein a casing that forms a buffer space is provided outside the side wall of the storage tank so as to surround the opening, and the pipe is connected to the casing. Storage device.

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