Biomass combustion system

Abstract

To provide a biomass combustion system capable of maintaining a good combustion state by reducing a water content of biomass fuel accommodated within a fuel storage.SOLUTION: A biomass combustion system includes fuel accommodation means for storing biomass fuel and combustion means for burning the biomass fuel. The fuel accommodation means includes a fuel accommodation space 37 for accommodating the biomass fuel. The combustion means is disposed in a combustion means arrangement chamber 12. The biomass combustion system also includes ventilation means 88 for communicating the combustion means arrangement chamber 12 and the fuel accommodation space 37 and air exhaust means 85 for discharging air in the fuel accommodation space. By discharging air in the fuel accommodation space 37 by the air exhaust means 85, air in the combustion means arrangement chamber 12 is introduced to the fuel accommodation space 37.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a combustion system for burning biomass fuel such as wood chips. [Background technology]

[0002] In forestry, trees that are not growing well are thinned out as part of the maintenance of mountains and fields. This generates thinned lumber. Also, when old houses are demolished to be rebuilt, waste lumber is generated. At sawmills, the ends are shaved off to obtain square lumber, creating offcuts.

[0003] These thinned wood, waste wood, scrap wood, etc. have traditionally had no uses and have been discarded. However, in recent years, there has been a growing momentum to make effective use of these waste wood, and various uses have been proposed. As one example, Patent Document 1 discloses a configuration in which thinned wood or the like is processed into chips and burned in a boiler to obtain thermal energy.

[0004] Furthermore, Patent Document 2 discloses a system for simultaneously supplying heat and electricity in which a solid fuel combustion device is installed in a container. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-3488 [Patent Document 2] Patent No. 2695088 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors have been making prototypes with the aim of mass-producing a biomass combustion system that uses biomass as fuel. The biomass combustion system envisioned by the inventors is a combination of a fuel tank and a boiler, with biomass fuel stored in the fuel tank.

[0007] In the biomass combustion system envisioned by the present inventors, biomass fuel is stored in the fuel storehouse just before being fed into the boiler, and the biomass fuel is supplied from the fuel storehouse to the boiler. Therefore, if the biomass fuel in the fuel storehouse is wet, there is a concern that it may not burn properly.

[0008] The present invention aims to solve the above-mentioned problems and proposes a biomass combustion system that can reduce the moisture content of biomass fuel stored in a fuel storehouse and maintain good combustion conditions. [Means for solving the problem]

[0009] An embodiment for solving the above-mentioned problems is a biomass combustion system having a fuel storage means for storing biomass fuel and a combustion means for burning the biomass fuel, wherein the fuel storage means has a fuel storage space for storing biomass fuel, the combustion means is arranged in a combustion means arrangement chamber, and has a ventilation means for connecting the combustion means arrangement chamber with the fuel storage space, and an exhaust means for exhausting air from the fuel storage space, and is characterized in that the biomass combustion system is capable of introducing air from the combustion means arrangement chamber into the fuel storage space by exhausting the air from the fuel storage space with the exhaust means.

[0010] In the biomass combustion system of this aspect, biomass fuel is stored in the fuel storage means, and the biomass fuel is supplied to the combustion means by the fuel supply means and used for combustion. In the biomass combustion system of this aspect, the air in the combustion means arrangement chamber is introduced into the fuel storage space by exhausting the air from the fuel storage space. In the biomass combustion system of this embodiment, the combustion means is disposed in the combustion means chamber. Because the combustion means generates heat, the temperature in the combustion means chamber is higher than outside. Therefore, by exhausting the air in the fuel storage space, the warm air in the combustion means chamber is introduced into the fuel storage space. As a result, the biomass fuel in the fuel containing means is exposed to heated air, reducing its moisture content.

[0011] In the above-described aspect, it is desirable that the fuel storage means and the combustion means are located in a common housing, the interior of the housing is partitioned to form a fuel storage chamber and a combustion means arrangement chamber, the fuel storage space is formed in the fuel storage chamber, and the partition has an opening that serves as the ventilation means.

[0012] According to the biomass combustion system of this aspect, the fuel storage means and the combustion means can be integrated into a single unit. In the biomass combustion system of this aspect, warm air is introduced into the fuel storage space from the adjacent combustion means arrangement chamber directly through the opening provided in the partition, so that the warm air is introduced into the fuel storage space before it cools down.

[0013] In the above aspect, it is desirable that an outside air inlet be provided at the bottom of the combustion means placement chamber.

[0014] According to this aspect, the outside air inlet also functions as a drain outlet, so that water does not accumulate in the combustion means arrangement chamber.

[0015] In each of the above-described aspects, it is desirable that the fuel storage means is located within a housing, that a bottom space is provided between the bottom of the housing and the bottom of the fuel storage space, that ventilation is ensured between the bottom space and the fuel storage space, and that the ventilation means is open to the bottom space.

[0016] In the combustion system of this aspect, the fuel storage space has a bottom, and a bottom space is provided between the bottom of the housing and the bottom of the fuel storage space. Warm air from the combustion means arrangement chamber is supplied to the bottom space by the ventilation means. In the combustion system of this embodiment, there is air permeability between the bottom space and the fuel storage space, so that air supplied to the bottom space enters the fuel storage means, exposing the biomass fuel to heated air and reducing its moisture content.

[0017] In each of the above-mentioned aspects, a large number of small holes are provided in the bottom, and these small holes ensure air permeability between the bottom space and the fuel storage space, and it is desirable that the small holes are not able to pass through the anticipated biomass fuel.

[0018] In the biomass combustion system of this embodiment, a number of small holes are provided at the bottom of the fuel storage space, and air supplied to the bottom space passes through the small holes and enters the fuel storage means, reducing the moisture content of the biomass fuel. The small holes are such that the biomass fuel cannot pass through, so the biomass fuel does not fall into the bottom space.

[0019] In each of the above-mentioned aspects, it is desirable to have a fuel supply means that connects the fuel storage means and the combustion means and supplies the biomass fuel in the fuel storage means to the combustion means, one end of the fuel supply means being in the bottom space, a communication part being at the bottom of the fuel storage space that connects the fuel storage space and the fuel supply means, and the biomass fuel in the fuel storage space entering the fuel supply means via the communication part.

[0020] In the biomass combustion system of this aspect, biomass fuel is stored in the fuel storage means, and the biomass fuel is supplied to the combustion means by the fuel supply means and used for combustion. In the biomass combustion apparatus of this embodiment, a communication part is provided at the bottom of the fuel storage space that connects the fuel storage space and the fuel supply means, and the biomass fuel in the fuel storage space enters the fuel supply means through the communication part. That is, in the biomass combustion system of this embodiment, the biomass fuel is taken out from the bottom side of the fuel storage space and is used for combustion. In the biomass combustion system of this embodiment, a bottom space is provided between the bottom of the housing and the fuel storage space. Heated air is supplied to the bottom space by the heated air supply means, and the heated air enters the fuel storage space from the bottom side of the fuel storage space. Therefore, the biomass fuel near the bottom of the fuel storage space comes into contact with air that is hot and has low humidity, causing the moisture content to drop more rapidly than in other locations.The biomass fuel with the lowest moisture content is then burned in order. [Effects of the Invention]

[0021] According to the biomass combustion system of the present invention, the moisture content of the biomass fuel stored in the fuel storehouse can be reduced to maintain a good combustion state. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view showing the configuration of a biomass combustion system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan cross-sectional view of a boiler unit of the biomass combustion system of FIG. 1. [Figure 3] FIG. 2 is a front cross-sectional view showing the internal structure of a boiler unit of the biomass combustion system of FIG. 1. [Figure 4] FIG. 2 is a cross-sectional perspective view of a fuel chamber of the biomass combustion system of FIG. 1. [Figure 5] 2 is a perspective view of the housing of the biomass combustion system of FIG. 1 with the door open. [Figure 6] FIG. 2 is a perspective view of a wall surface that forms a fuel storage space in the housing of the biomass combustion system of FIG. 1 and corresponds to a door. [Figure 7] 2 is a perspective view showing the internal structure of a fuel storage space in the housing of the biomass combustion system of FIG. 1. FIG. [Figure 8] FIG. 4 is a perspective view of a lower corner of the fuel storage space. [Figure 9] FIG. 2 is an exploded perspective view of a fuel storage space. [Figure 10]10A and 10B are plan views of the fuel storage space, in which FIG. 10A shows a state in which the agitating member is stopped, and FIG. 10B shows the range of motion of the lateral agitating pieces of the agitating member. [Figure 11] 10(a), 10(b), and 10(c) are perspective views showing modified examples of the protrusions of the stirring member. [Figure 12] 10(a), 10(b), and 10(c) are perspective views showing modified examples of the upper agitating piece of the agitating member. [Figure 13] 10(a) to 10(d) are plan views of the fuel storage space, illustrating the relationship between the inner wall of the fuel storage space and the overall length of the stirring member, showing the state in which a sealing member is attached to the fuel storage space. [Figure 14] (a) to (c) are plan views of the fuel storage space, and are explanatory diagrams explaining the relationship between the inner wall of the fuel storage space and the overall length of the stirring member, showing the state in which a sealing member is not attached to the fuel storage space. [Figure 15] FIG. 4 is a cross-sectional view of the fuel storage space, illustrating the height relationship between the sealing member and the agitating member. [Figure 16] FIG. 2 is a perspective view of a receiving device of the biomass combustion system of FIG. 1. [Figure 17] FIG. 17 is a side cross-sectional view showing the state in which the receiving device of FIG. 16 is installed in a pit. [Figure 18] FIG. 17 is a front cross-sectional view showing the state in which the receiving device of FIG. 16 is installed in a pit. [Figure 19] FIG. 2 is a side view of a vertical conveying device of the biomass combustion system of FIG. 1. [Figure 20] 2 is a cross-sectional perspective view of a connection portion between a vertical conveying device and a housing of the biomass combustion system of FIG. 1. FIG. [Figure 21] 2 is a cross-sectional view of a connection portion between a vertical conveying device and a housing of the biomass combustion system of FIG. 1. FIG. [Figure 22] FIG. 1A is a perspective view of a fixture that connects the vertical conveying device to the housing, and FIG. 1B is a side view thereof. [Figure 23] 23(a), (b), and (c) are explanatory views showing how the fixture shown in FIG. 22 is used. [Figure 24]FIG. 2(a) is an explanatory diagram showing the relationship between the vertical conveying device and the housing in the embodiment shown in FIG. 1, and FIGS. 2(b), 2(c), and 2(d) are explanatory diagrams showing the relationship between the vertical conveying device and the housing in other embodiments. [Figure 25] FIG. 1 is a configuration diagram illustrating an example of a fuel drying system. [Figure 26] FIG. 10 is a front cross-sectional view showing the internal structure of a boiler unit illustrating another example of a fuel drying system. [Figure 27] FIG. 10 is a configuration diagram of a biomass combustion system according to another embodiment of the present invention. [Figure 28] FIG. 10 is a configuration diagram of a biomass combustion system according to another embodiment of the present invention. [Figure 29] FIG. 10 is a perspective view showing the internal structure of a fuel storage space in a biomass combustion system according to another embodiment of the present invention. [Figure 30] FIG. 10 is a perspective view showing the internal structure of a fuel storage space in a biomass combustion system according to another embodiment of the present invention. [Figure 31] FIG. 2 is a plan view showing the equipment layout of the consumption-side device group of the biomass combustion system of FIG. 1. [Figure 32] FIG. 2 is a piping diagram of the consumption-side devices of the biomass combustion system of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described. The biomass combustion system 1 of this embodiment burns biomass fuel to obtain thermal energy, and uses the thermal energy to provide hot water and the like. Here, "biomass" refers to substances derived from plants and animals. The biomass combustion system 1 of this embodiment uses biomass fuel, which is particularly plant-based biomass such as wood chips and grass, and is easily combustible. However, the present invention does not exclude systems that use other biomass fuels. Suitable biomass fuels for the biomass combustion system 1 of this embodiment include thinned wood, sawdust and other lumber waste, pruned or felled trees, and waste materials from demolished houses, which are crushed and processed into chips. Herbaceous biomass fuels such as straw waste and weeds can also be used.

[0024] The biomass combustion system 1 of this embodiment (hereinafter simply referred to as the combustion system 1) can be broadly divided into a boiler unit 2 that stores and burns biomass fuel, a fuel supply side device group 5 that introduces biomass fuel to the boiler unit 2, and a consumption side device group 6 that utilizes the heat generated by the boiler unit 2. In this embodiment, the boiler unit 2 and the consumption side device group 6 form a hot water supply system 18. The combustion system 1 of this embodiment has a heat storage tank 7, and heats the heat medium in the heat storage tank 7 with the heat generated by the boiler unit 2, and the heat of the heat medium is used for heat exchange and water supply, etc. It also has a fuel drying system 8 that dries the biomass fuel stored in the boiler unit 2 using the heat from the heat storage tank 7. Below, we will explain each individually.

[0025] (Boiler unit 2) As shown in Figures 2 and 3, the boiler unit 2 is a combination of a fuel storehouse (fuel storage chamber 11) that stores biomass fuel and a boiler (combustion means) 15. In this embodiment, there is one housing 10, and the fuel storage means and the boiler 15 are located within this single housing 10. That is, in the combustion system 1 of this embodiment, the housing 10 is divided into a fuel storage chamber (fuel storage means) 11 and a combustion means arrangement chamber 12. Biomass fuel is stored in the fuel storage chamber 11. Furthermore, a boiler 15 is installed in the combustion means arrangement chamber 12. The boiler 15 is combustion means that combusts biomass fuel. In this embodiment, a wood chip boiler that uses wood chips as fuel is used. A supply conveyor (fuel supply means) 16 is installed between the fuel storage chamber 11 and the combustion means arrangement chamber 12, and the biomass fuel stored in the fuel storage space 37 is supplied to the boiler 15. The biomass fuel is then combusted in the boiler 15 to generate thermal energy.

[0026] (Housing 10) The housing 10 is a box made of iron. In this embodiment, a shipping container used for sea transportation is used as the housing 10 of the boiler unit 2. The housing 10 is a rectangular parallelepiped metal box having a front wall 21, a rear wall 22, a left side wall 23, a right side wall 25, a top wall 27, and a bottom wall . 1 and 5, a door 30 is provided on the left side wall 23 of the housing 10. A fuel entrance 31 is provided on the top wall 27 of the housing 10. A partition wall 32 is provided inside the housing 10, and as shown in FIGS. 2 and 3, the partition wall 32 divides the inside of the housing 10 into a fuel storage chamber 11 and a combustion means arrangement chamber 12.

[0027] The fuel storage chamber 11 is an area that functions as a fuel storehouse for storing biomass fuel. The fuel storage chamber 11 is divided into upper and lower sections by a bottom plate 35, and the area above the bottom plate 35 functions as a fuel storage space 37. The fuel storage space 37 has a bottom plate 35 (bottom) and peripheral walls 38, 40, 41, and 42. The upper part is closed by the top wall 27 of the housing 10 itself. A fuel inlet 31 provided in the top wall 27 opens into the fuel storage space 37. In this embodiment, as shown in Fig. 4, three side surfaces of the fuel storage space 37 are lined with wooden pieces 33, 47. That is, the wooden pieces 33 are attached to the peripheral walls 38, 40, 42 of the fuel storage space 37. In this embodiment, wooden boards are used as the wooden pieces 33. The wooden pieces 33 are thin, rectangular boards. The wooden pieces 33 are solid boards with no surface treatment and have moderate moisture absorption properties. In this embodiment, the peripheral wall 41 of the fuel storage space 37 on the door 30 side is made by stacking a plurality of wooden pieces 47 arranged horizontally.

[0028] In the fuel storage chamber 11 employed in this embodiment, the peripheral walls 38, 40, 41, and 42 are substantially made of wood, and the peripheral wall portion of the fuel storage chamber 11 is entirely covered with wood. In this embodiment, the peripheral wall 41 on the left side of the fuel storage space 37 is located opposite the door 30 of the housing 10 . In this embodiment, the peripheral wall 41 that forms the left side surface of the fuel storage space 37 can be removed. More precisely, as described above, the fuel storage chamber 11 employed in this embodiment has peripheral walls 38, 40, 41, and 42 that are substantially formed by the wooden pieces 33 and 47, and the peripheral wall 41 made of the wooden piece 47 can be removed. In this embodiment, the wooden piece 47 that forms the peripheral wall 41 and functions as a closing member that closes one side of the fuel storage chamber 11 can be removed to open that side of the fuel storage chamber 11.

[0029] As described above, the door 30 is provided on the left side wall 23 of the housing 10 (FIG. 5). That is, the left side wall 23 of the housing 10 has an opening 45. 6, in this embodiment, holding members 46a and 46b are provided inside the housing 10 along the left and right edges of the opening 45. The holding members 46a and 46b are groove-shaped members with a U-shaped cross section. The holding members 46a and 46b are disposed in a vertically elongated position with the grooves facing each other. The grooves of the holding members 46a and 46b are open at the top.

[0030] The peripheral wall 41 that forms the left side of the fuel storage space 37 is formed by stacking wooden pieces 47 vertically, with the ends of the wooden pieces 47 fitted into the vertical grooves 48 of the left and right holding members 46a, 46b, as shown in Figure 6. The wooden pieces 47 are rectangular boards, and are stacked vertically in a horizontal position to form the wall. In this embodiment, each wooden piece (closing member) 47 is shifted upward to remove it from the vertical grooves 48 of the holding members 46a, 46b, and this is repeated sequentially, thereby allowing the wooden peripheral wall 41 portion of the fuel storage space 37 to be removed. Therefore, by opening the door 30 of the housing 10 and then sliding the wooden pieces 47 upward and removing them, one side of the fuel storage space 37 can be opened. Then, an operator can enter the fuel storage space 37 and perform the desired work. The wooden piece (closing member) 47 described above is a rectangular plate, but the shape of the wooden piece (closing member) is not limited to a rectangular plate. For example, it may be a square timber or a round bar.

[0031] . In this embodiment, multiple pieces of wood 47 are placed horizontally with their widths vertical and stacked vertically to form a wall, but one side of the fuel storage space 37 may simply be blocked by a single board (closing member). In this embodiment, the housing 10 is provided with the holding members 46a and 46b, but the closing member may be fixed to the end surfaces of the peripheral walls 38 and 42 of the fuel storage space 37 with removable fastening elements such as screws.

[0032] (Fuel storage space 37) The fuel storage space 37 is located inside the fuel storage chamber 11 of the housing 10, and is a region surrounded by a bottom plate 35 (bottom) and peripheral walls 38, 40, 41, and 42. The planar shape of the fuel storage space 37 is approximately square. In this embodiment, the bottom plate 35 (bottom portion) is inclined so that the combustion means arrangement chamber 12 side is at the top. An agitating member 50 is attached to the bottom plate 35 . The bottom plate 35 (bottom) of the fuel storage space 37 is located above and spaced apart from the bottom wall 28 of the housing 10 as shown in Figure 3, and a bottom space 51 is present between the bottom wall 28 of the housing 10 and the fuel storage space 37. In the bottom space 51, there is an end of the supply conveyor (fuel supply means) 16.

[0033] 9, the bottom plate 35 is made of a steel plate, such as a punched metal, having a large number of small holes 52 formed therein. The small holes 52 are distributed evenly over the entire area of ​​the bottom plate 35. The small holes 52 in the bottom plate 35 are of a size and shape that prevent biomass fuel of an expected size and shape from passing through. However, the small holes 52 can allow air to pass through, and the small holes 52 ensure breathability above and below the bottom plate 35. The bottom plate 35 is also provided with a communication section 53 through which the biomass fuel falls. The communication section 53 in this embodiment is a rectangular opening, and is formed near the partition wall 32.

[0034] 7, 8, and 9, in this embodiment, a sealing member 55 is provided at the corner of the lower end of the fuel storage space 37. As shown in FIG. 9, the sealing member 55 is an isosceles triangular plate having a base 56 and two hypotenuses 57. 8, in this embodiment, an apex 60 of the isosceles triangle is located at a joining portion 61 between any two of the peripheral walls 38, 40, 41, and 42, and a base 56 is in contact with the bottom plate 35 (bottom) of the fuel storage space 37. In addition, two hypotenuses 57 of the isosceles triangle are in contact with any one of the peripheral walls 38, 40, 41, and 42.

[0035] Therefore, the sealing member 55 is in an inclined position as a whole. In this embodiment, the sealing member 55 forms an inclined surface at a three-corner portion having a corner formed by the joint 61 of any two of the peripheral walls 38, 40, 41, 42, and two corners formed by any two of the peripheral walls 38, 40, 41, 42 and the bottom plate 35 (bottom). In this embodiment, the three corners at the bottom of the fuel storage space 37 are closed by sealing members 55 to prevent biomass fuel from accumulating in the four corners. In this embodiment, the three corners are closed with plates, but the corners may be filled with a three-dimensional object such as a triangular pyramid, putty, or the like.

[0036] It is desirable that all corners of the lower portion of the fuel receiving space 37 are closed by the closing members 55, but the present invention does not require that all corners be closed by the closing members 55. In the fuel storage chamber 11 employed in this embodiment, a sealing member 55 is provided on the bottom plate 35 of the fuel storage space 37, and the sealing member 55 is provided at the lower corner of the fuel storage space 37 to prevent blind spots in the movement trajectory of the agitating member 50. If the agitating member 50 rotates at an intermediate height position, it is desirable to provide the sealing member at an intermediate height position accordingly. In this case, the corner formed by the joining portion 61 of the two peripheral walls 38, 40, 41, 42 is closed with a sealing member.

[0037] (agitating member 50) As shown in FIGS. 8 and 9, the stirring member 50 has a rotary plate 62 provided with a convex portion 65, an upper stirring piece 66, and a side stirring piece 67. The rotary plate 62 is a circular plate. The protrusion 65 is located at the center of rotation of the rotary plate 62 and protrudes upward. In this embodiment, the protrusion 65 is conical. The upper stirring piece 66 has a vertical bar portion 63 that stands vertically from the upper surface of the rotating plate 62 and a horizontal bar portion 68 that connects the middle of the vertical bar portion 63 to the protrusion 65. The side stirring pieces 67 are elongated plates that have flexibility and elasticity like whips or leaf springs, and two of them are provided on the side surfaces of the rotating plate 62. The side stirring pieces 67 can also be called stirring blades. The natural length of the lateral stirring pieces 67 is long, and at the natural length, the free ends thereof reach the peripheral walls 38, 40, 41, and 42 of the fuel storage space 37. When the stirring members 50 are attached to the bottom plate 35 (bottom), they are in the state shown in Figure 10(a), with their tips abutting the peripheral walls 38, 40, 41, and 42 and curved in a bow shape as a whole. Of course, they may be shaped in a bow shape from the beginning.

[0038] 7, 8, and 9, the agitating member 50 is attached to the bottom plate 35 of the fuel storage space 37, and is rotated at the bottom plate 35 by a driving source 73 shown in FIG. 9. That is, the driving source 73, which is composed of a motor 71 and a reducer 72, is disposed in the bottom space 51. An output shaft 75 of the reducer 72 passes through a through-hole 76 provided in the bottom plate 35 and is connected to the center of the rotating plate 62. The rotating plate 62 is rotatably supported on the bottom plate 35 by a bearing (not shown).

[0039] When the rotary plate 62 is rotated by the driving source 73, the convex portion 65, the upper agitating pieces 66, and the side agitating pieces 67 rotate within the fuel containing space 37, preventing bridging of the biomass fuel. Furthermore, since there are protrusions 65 on the rotating plate 62, biomass fuel is less likely to remain on the rotating plate 62. That is, the center of the rotating plate 62 does not have a stirring function, but in this embodiment, there are protrusions 65 on the rotating plate 62, and the area of ​​the central portion is small. Therefore, biomass fuel is less likely to remain in the center. In this embodiment, the three corners at the bottom of the fuel storage space 37 are closed by the sealing members 55, and the bottom of the fuel storage space 37 is substantially octagonal and close to a circle. Therefore, as the agitating member 50 rotates, the side agitating pieces 67 reach every corner and scrape out the biomass fuel. That is, the agitating member 50 is in a slightly inclined position, but this position has a horizontal component. Therefore, the agitating member 50 rotates in a position near the bottom of the fuel containing space 37 and has a horizontal component, scraping out the biomass fuel remaining in the lower sides and corners of the fuel containing space 37. Therefore, according to this embodiment, the side agitating pieces 67 sweep the area shown by the hatched area in FIG. 10(b), and the biomass fuel does not stagnate in the corners. In addition, in this embodiment, the bottom plate 35 is inclined and the four corners of the lower end of the fuel storage space 37 are inclined, which also has the effect of collecting the upper biomass fuel toward the center.

[0040] In this embodiment, a conical protrusion 65 is used, but the shape of the protrusion 65 is not limited to a cone, and may be, for example, a truncated cone as shown in Fig. 11(a) or a pyramid as shown in Fig. 11(b). Also, as shown in Fig. 11(c), some kind of member may protrude from the protrusion.

[0041] Similarly, the shape of the upper stirring piece 66 can be any shape, such as an "L" shape as shown in Figure 12(a), a frame shape as shown in Figure 12(b), or a blade shape as shown in Figure 12(c).

[0042] The total length of the stirring member 50 including the lateral stirring pieces 67 is not limited, and may be such that the free end does not reach the peripheral walls 38, 40, 41, and 42 of the fuel storage space 37, as shown in Figure 13(a). Alternatively, as shown in Figure 13(b), the length may be sufficiently longer than the diagonal of the fuel storage space 37.

[0043] The ideal total length of the agitating member 50 is such that its natural length is equal to or greater than the width W of the fuel containing space 37 as shown in FIG. 14(a) and equal to or less than the length of the diagonal line D as shown in FIG. 14(b). As described above, the total length of the agitating member 50 is not limited and can be any length, so the total length of the agitating member 50 may of course be less than the width W of the fuel containing space 37. Alternatively, the agitating member 50 may have a length greater than the length of the diagonal line D. The planar shape of the fuel storage space 37 is generally square, but if the planar shape of the fuel storage space 37 is rectangular, the longer diagonal line is used as the reference. If the planar shape of the fuel storage space 37 is a polygon with five or more sides, the longest diagonal line D among the multiple diagonals is used as the reference. If the center of the agitating member 50 is considered as the reference point, the calculation can also be performed by setting the diagonal line D as twice the distance from the center of the agitating member 50 to the farthest position on the inner wall. This calculation can also be used when the center of the agitating member 50 is shifted from the center of the fuel storage space 37.

[0044] The width W is based on the shortest width. It is also possible to calculate the width W by taking the diagonal line D as twice the distance from the center of the stirring member 50 to the closest position on the inner wall. That is, it is desirable that the overall length of the stirring member 50, including the side stirring pieces 67, is as shown in FIG. 14(c).

[0045] An agitating member 50 having an ideal total length contacts the peripheral walls 38, 40, 41, 42 of the fuel containing space 37 and the closing member 55 over the majority of the area of ​​the fuel containing space 37. That is, 80 percent or more of the peripheral walls 38, 40, 41, 42 and the closing member 55 contact the agitating member 50, more preferably 90 percent or more of the peripheral walls 38, 40, 41, 42 and the closing member 55 contact the agitating member 50, and most preferably the entire area contacts the agitating member 50. It is recommended that the limit of the position where the free end side of the agitating member 50 comes into contact with the peripheral walls 38, 40, 41, and 42 of the fuel storage space 37 be approximately 10 percent of the width W before and after the center position, which is approximately one-fourth of the width W of the fuel storage space 37 from the corner of the fuel storage space 37, as shown in Figures 13(d) and 14(c).

[0046] Furthermore, when comparing the height h of the side stirring pieces 67 of the stirring member 50 with the height H of the sealing member 55, the sealing member 55 is higher, as shown in Figure 15. Of course, the heights of the two can be arbitrary, and the side stirring pieces 67 may be higher.

[0047] In the combustion system 1 of this embodiment, the inner surface of the fuel storage space 37 is covered with wood. As described above, wood has moderate hygroscopicity, so it can absorb moisture from the fuel storage chamber 11, making it difficult for the stored biomass fuel to become wet. Still, instead of wood, other moisture-absorbing materials may be used to line the inner surface of the fuel-receiving space 37 .

[0048] (Supply Conveyor 16) As described above, a series of fuel supply means is provided between the fuel storage chamber (fuel storage means) 11 and the combustion means arrangement chamber 12. That is, a supply conveyor (fuel supply means) 16 is provided between the fuel storage chamber (fuel storage means) 11 and the boiler (combustion means) 15. In this embodiment, a screw conveyor is used as the supply conveyor 16. The supply conveyor 16 is not limited to a screw conveyor, and may be a belt conveyor or a bucket conveyor. It may also be a piston-shaped conveyor that pushes out biomass fuel.

[0049] As shown in FIG. 3, the starting end of the supply conveyor 16 is located in the bottom space 51 of the fuel storage chamber 11. The starting end of supply conveyor 16 is located directly below communication section (fuel supply means) 53 provided on bottom plate 35 , and is connected to communication section 53 via chute (fuel supply means) 78 . The middle portion of the supply conveyor 16 is inserted through an opening 80 formed in the partition wall 32 . 3, the end of the supply conveyor 16 is connected to a fuel supply port 77 of the boiler 15. A chute (fuel supply means) may be provided between the end of the supply conveyor 16 and the fuel supply port 77. In this embodiment, an electromagnet 81 is attached to the middle of the supply conveyor 16. The electromagnet 81 is also provided with magnetic attraction amount detection means 82 that detects when a predetermined amount of metal has been attracted. The magnetic attraction amount detection means 82 is, for example, a weight sensor, and detects the amount of metal attracted to the electromagnet 81 based on changes in the surrounding weight.

[0050] The biomass combustion system 1 of this embodiment also has an automatic discharge mechanism (not shown) that automatically removes the sucked metals and automatically discharges them to the outside. The biomass combustion system 1 of this embodiment also has a supply conveyor stopping means that stops the supply conveyor 16 and an automatic boiler stopping means that stops the boiler 15. The automatic discharge mechanism, the supply conveyor stopping means and the boiler automatic stopping means operate in stages according to the amount of metal attracted by the electromagnet 81. That is, in the biomass combustion system 1 of this embodiment, when the amount of metal attracted by the electromagnet 81 reaches a predetermined amount corresponding to the appropriate amount to be discharged, the automatic discharge mechanism operates to discharge the accumulated metal to the outside. For example, if the metals cannot be completely discharged and exceed the appropriate amount of discharge, reaching a predetermined amount equivalent to a warning amount, the supply conveyor stopping means will automatically operate to stop the supply conveyor 16 and stop the supply of biomass fuel to the boiler 15. Furthermore, when the metal exceeds the warning amount and reaches a predetermined amount corresponding to a dangerous amount, the automatic boiler stop means is activated to automatically stop the boiler 15, thereby preventing breakdown of the boiler 15.

[0051] (ventilation means) The boiler unit 2 is provided with a ventilation fan and a ventilation duct. These mainly serve to introduce warm, dry air from the combustion means arrangement chamber 12 into the fuel storage chamber 11 to reduce the moisture content of the biomass fuel and promote drying. In this embodiment, a fuel storage ventilation fan (exhaust means) 85 is provided on the upper side of the fuel storage chamber 11. An internal ventilation passage (ventilation means) 88 is provided inside the housing 10, connecting the combustion means arrangement chamber 12 and the fuel storage chamber 11. The internal ventilation passage (ventilation means) 88 is an opening provided in the partition wall 32, and connects the combustion means arrangement chamber 12 and the bottom space 51 of the fuel storage chamber 11. Furthermore, an outside air intake (outside air introduction port) 83 is provided on the bottom wall 28 of the combustion means arrangement chamber 12. The reason why the outside air intake 83 is provided on the bottom wall 28 is to prevent water from accumulating inside the combustion means arrangement chamber 12. That is, in this embodiment, the outside air intake 83 also functions as a drainage port. In this embodiment, the combustion means arrangement chamber 12 and the bottom space 51 of the fuel storage chamber 11 are connected by an internal ventilation passage (ventilation means) 88, but the combustion means arrangement chamber 12 and the fuel storage space 37, which is the upper space of the fuel storage chamber 11, may also be connected by an internal ventilation passage (ventilation means).

[0052] (Fuel supply side equipment group 5) Next, we will explain the fuel supply side device group 5. As described above, the fuel supply side device group 5 is a group of devices that introduce biomass fuel into the boiler unit 2. In this embodiment, the fuel supply side device group 5 constitutes an introduction means that introduces biomass fuel into the fuel storage chamber (fuel storage means) 11. The fuel supply side device group 5 is composed of a receiving device 100 that receives biomass fuel from the outside, and a vertical conveying device 101 that transports the biomass fuel received by the receiving device 100 to the fuel storage chamber (fuel storage means) 11 of the boiler unit 2.

[0053] (Receiving device 100) As shown in Figures 16 to 18, the receiving device 100 is composed of an input hopper 103 into which biomass fuel is directly input from a bulk vehicle, dump truck, etc. (not shown), and an output means 105 that outputs the biomass fuel input into the input hopper 103 to the vertical conveying device 101. The input hopper 103 is a hopper of a certain length with a rectangular input opening 106. As described above, since biomass fuel is input directly into the input hopper 103 from a bulk vehicle, dump truck, or the like, it is desirable that the length of the input hopper 103 be wider than the width of the bulk vehicle, dump truck, or the like. The input hopper 103 has a widely opened input port 106, similar to known input hopper, and has an inclined surface inside that converges to a certain position.

[0054] The delivery means 105 is a screw conveyor. That is, the cross section is approximately circular, and a screw-shaped delivery member 108 is housed in a cylindrical housing 107. By rotating the delivery member 108, the biomass fuel is transported laterally. The above-mentioned feeding hopper 103 is connected to the starting end of the delivery means 105. Furthermore, the vertical conveying device 101 is connected to the end of the delivery means 105. The feeding hopper 103 is attached in an inclined position as shown in Figures 16 and 17. That is, the feeding hopper 103 is in an inclined position, and the rectangular feeding opening 106 is open in the inclined direction.

[0055] In this embodiment, a motor 110 and a reducer 111 are installed on the starting end side of the housing 107, and by driving the motor 110, a screw-shaped feed member 108 rotates. In this embodiment, as shown in FIGS. 16 and 18, the motor 110 is placed vertically, and the axis of rotation is converted to a horizontal direction by a reducer 111 at the bottom. As is well known, a power supply 112 for the motor 110 is provided on the side of the motor 110 .

[0056] In the combustion system 1 of this embodiment, as shown in Figures 1, 17, and 18, a pit (recess) 115 is dug on the front side of the boiler unit 2 parallel to the boiler unit 2, and part of the receiving device 100 is housed in the pit 115. Therefore, the area including the pit (recess) 115 is the installation area 117 of the receiving device 100 , and the surface of the area surrounding the opening of the pit 115 is the upper surface 91 of the installation area 117 .

[0057] The pit 115 employed in this embodiment is formed outdoors and is a recessed portion created by excavating the ground. 17 and 18, in the pit 115 of this embodiment, the height of the opening 113 is the same as the height of the ground surface 126. That is, the height of the opening 113 of the recess is the same as the height of the ground surface 126. As described above, the area including the pit (recess) 115 is the installation area 117 of the receiving device 100, and therefore in this embodiment, the height of the upper surface 91 of the installation area 117 of the receiving device 100 is the same as the height of the ground surface 126.

[0058] In this embodiment, the top of the receiving device 100 protrudes outward (upward) from the pit 115 . 17 and 18, all of the inlets 106 of the input hoppers 103 are above the upper surface 91 of the installation area 117 of the receiving device 100, and the input inlets 106 are above the ground surface 126. However, the height of the input inlets 106 of the input hoppers 103 above ground level is low. All of the motors 110 also protrude outward (upward) from the pit 115. That is, as shown in Figures 17 and 18, all of the motors 110 are above the upper surface 91 of the installation area 117 of the receiving device 100, and the motors 110 are above the ground surface 126. The remaining portion is mostly housed in the pit 115 .

[0059] In the combustion system 1 of this embodiment, the receiving device 100 that receives biomass fuel is housed in a pit 115, and most of the receiving device 100 is installed underground. Therefore, the height of the input hopper 103 above ground is low. According to this embodiment, the inlet 106 of the feeding hopper 103 is located at a low position, so that when the bed of a dump truck, for example, is tilted, the corner of the bed is unlikely to hit the feeding hopper 103. Therefore, according to this embodiment, biomass fuel can be directly fed from a dump truck or the like into the inlet 106 of the feeding hopper 103.

[0060] In the combustion system 1 of this embodiment, the top of the input hopper 103 protrudes upward from the pit 115. The top of the input hopper 103 is also higher than the upper surface 91 of the installation area 117 of the receiving device 100, and the top of the input hopper 103 is above the ground surface 126. In this embodiment, the input inlet 106 of the input hopper 103 is above the upper surface 91 of the installation area 117 of the receiving device 100, and the input inlet 106 of the input hopper 103 is above the ground surface 126. Therefore, even if heavy rain occurs and the pit 115 is submerged, the inlet 106 of the feeding hopper 103 is open above the water surface, so water does not enter through the feeding hopper 103. Therefore, water is unlikely to accumulate inside the housing 107 of the delivery means 105.

[0061] In the combustion system 1 of this embodiment, even if heavy rain falls and the pit 115 is submerged, water does not accumulate inside the housing 107 of the delivery means 105, making it easy to recover after heavy rain. That is, if the pit 115 is submerged due to heavy rain, a pump will be used to drain the water from the pit 115. Here, draining the water from the pit 115 is relatively easy. However, once water accumulates inside the housing 107 of the delivery means 105, it is not easy to drain it. Furthermore, if biomass fuel is received and transported while water is accumulated inside the housing 107, the biomass fuel will absorb water and become difficult to burn. In contrast, the receiving device 100 used in this embodiment is designed to prevent water from entering the sending means 105, so that even in heavy rain, water will not accumulate inside the housing 107, eliminating the hassle of draining water and problems such as wetting the biomass fuel. Similarly, stones blown by strong winds are less likely to enter the inlet 106 of the inlet hopper 103.

[0062] Furthermore, in the receiving device 100 employed in this embodiment, the motor 110 also protrudes out of the pit 115 and is located above the upper surface 91 of the installation area 117, and the motor 110 is also located above the ground surface 126. Therefore, even if the pit 115 is submerged, the motor 110 will not be submerged. Since the power supply unit 112 is located on the side of the motor 110, the power supply unit 112 will also not be submerged. Therefore, failures such as poor insulation will not occur, and recovery after heavy rain will be easy.

[0063] In the above-mentioned pit (recess) 115, the height of the opening 113 is the same as the height of the ground surface 126, but a dam-like frame is often provided around the opening 113. There are also pits where the entire structure is raised like a platform and a recess is formed in the center. In other words, there are many pits with a structure where the periphery of the opening is higher than the ground surface. In pits with such a structure, the upper surface of the dam-like frame or the raised area is the installation area 117 of the receiving device 100.

[0064] When a pit with such a structure is employed, the height of the open end of the pit, which is the upper surface of the installation area of ​​the receiving device 100, is higher than the ground surface 126 in the first place. Therefore, even when the receiving device 100 is installed in a pit whose opening is surrounded by a higher level than the ground surface, if the top of the input hopper 103, particularly the input port 106 of the input hopper 103, protrudes above the opening of the pit, even if the pit is submerged, the input port 106 of the input hopper 103 will be open above the water surface and water will not enter through the input hopper 103. Similarly, if the motor 110 protrudes out of the pit and the receiving device 100 is located above the upper surface 91 of the installation area 117, the motor 110 will not be submerged. Furthermore, in a pit where the area around the opening is higher than the ground surface, it is difficult for water to get into the pit in the first place.

[0065] In the embodiment described above, a screw conveyor is used as the delivery means 105. The delivery means 105 is not limited to a screw conveyor, and may be a belt conveyor or a bucket conveyor. It may also be a piston-shaped device that pushes out the biomass fuel. It is also recommended to provide a lid 116 as shown in FIG. 16, and cover the feeding hopper 103 with the lid 116 to close the feeding port 106 during rainy weather or when the device is not in operation, thereby preventing rainwater from entering. When waste materials from houses are used as biomass fuel, it is desirable to install a dust removal device for removing dust near the receiving device 100.

[0066] (Vertical conveying device 101) The vertical conveying device 101 is composed of a vertical feeding means 120 and a chute 121, which are installed in an inclined position, as shown in FIGS. The vertical feeding means 120 is a screw conveyor. That is, the cross section is approximately circular, and a screw-shaped feeding member 122 is housed inside a cylindrical housing 118. By rotating the feeding member 122, the biomass fuel is conveyed in the vertical direction.

[0067] In this embodiment, a motor 123 and a reducer 125 are installed on the distal end side of the housing 118, and by driving the motor 123, a screw-shaped feed member 122 rotates. As described above, the starting end of the vertical feeding means 120 is connected to the end of the delivery means 105 of the receiving device 100. In other words, the starting end of the vertical feeding means 120 is located on the side of the delivery means 105 of the receiving device 100. The vertical feeding means 120 extends diagonally upward and rearward relative to the receiving device 100. Alternatively, the height of the distal end of the vertical feed means 120 exceeds the height of the housing 10. The vertical feed means 120 is attached in an inclined position, and its distal end reaches approximately the middle of the housing 10 in plan view. The distal end of the vertical feed means 120 reaches above the fuel inlet 31 formed in the top wall 27 of the housing 10. The middle portion of the vertical feed means 120 is connected to the housing 10 via a fixture 130 and an auxiliary metal fitting 131 .

[0068] The fixture 130 is made of steel, and as shown in FIGS. 20 and 22, side plates 141a and 141b are provided on both sides of a fixing plate (fixing portion) 140. The fixed plate 140 is a rectangular plate. The side plates 141a and 141b are rectangular in shape with a portion missing, and have parallel vertical sides 142 and 143, parallel horizontal sides 145 and 146, and a diagonal side 147. That is, one vertical side 143 is shorter than the other vertical side 142, and one horizontal side 146 is shorter than the other horizontal side 145. The shorter vertical side 143 and the shorter horizontal side 146 are connected by a hypotenuse 147. The side plates 141a and 141b are located on both sides of the fixed plate 140 and stand upright relative to the fixed plate 140. The side plates 141a and 141b are parallel to each other, and the distance A between them is slightly wider than the width B of the housing 118 of the vertical feed means 120. That is, as shown in Figures 20 and 21, the housing 118 of the vertical feed means 120 can fit between the side plates 141a and 141b. In this embodiment, the distance between the side plates 141a and 141b corresponds to the width of the vertical feed means (vertical conveying device) 120, and the vertical feed means 120 is sandwiched between the side plates 141a and 141b.

[0069] The side plates 141a and 141b are provided with a large number of mounting holes 133. In this embodiment, the mounting holes 133 are concentrated at positions closer to the longer vertical side 142, but the mounting holes 133 may be provided on the entire surface. In this embodiment, the mounting holes 133 are arranged in two rows and four columns, but the arrangement and number of mounting holes 133 may be arbitrary. However, it is necessary to provide a greater number of mounting holes 133 than the number of mounting holes 133 that will actually be used. The auxiliary metal fitting 131 is strip-shaped and has two mounting holes 135 formed near the tip. The number of mounting holes 135 is optional.

[0070] In this embodiment, when installing the vertical feed means 120 of the vertical conveying device 101, the vertical conveying device 101 is connected to the housing 10 by selectively using the mounting holes 133 of the fixing device 130 depending on the posture of the vertical feed means 120. That is, in this embodiment, the fixing plate 140 of the fixing device 130 is attached to one surface of the housing 10 by welding or other known methods. Then, the fixing device 130 and the housing 118 of the vertical feed means 120 are screwed together via auxiliary metal fittings 131. Here, the attachment of the vertical feed means 120 is so-called on-site adjustment, and the position varies slightly depending on the site. The fixture 130 employed in this embodiment is provided with more mounting holes 133 than necessary in advance, so that the vertical feed means 120 can be attached using the mounting holes 133 required for on-site adjustment.

[0071] For example, in Figure 23(a), the third mounting hole 133 and the sixth mounting hole 133 are selected to attach the vertical feed means 120 to the housing 10. In Figure 23(b), the second mounting hole 133 and the fifth mounting hole 133 are selected to attach the vertical feed means 120 to the housing 10. In Figure 23(c), the first mounting hole 133 and the fifth mounting hole 133 are selected to attach the vertical feed means 120 to the housing 10.

[0072] In this embodiment, the end of the vertical feed means 120 and the fuel inlet 31 formed in the top wall 27 of the housing 10 are connected by a chute 121. The chute 121 employed in this embodiment has deformability. For example, the chute 121 itself may be made of flexible rubber or the like, and can function as a chute even if it is deformed to a certain extent. Alternatively, multiple metal tubes may be connected by flexible rubber or resin, and can function as a chute even if it is deformed to a certain extent. Alternatively, multiple metal tubes may be connected by a metal that undergoes plastic deformation, and can function as a chute even if the connecting parts are plastically deformed.

[0073] In this embodiment, the chute 121 having a variable displacement function is used, so that the alignment of the vertical feeding means 120 and the housing 10 is easy. That is, the connection between the vertical transport means 120 and the fuel carrying inlet 31 formed in the top wall 27 of the housing 10 is also adjusted on-site, and the position varies slightly depending on the site. The chute 121 employed in this embodiment has deformability, so that it can be deformed at the installation site so as to connect the vertical feed means 120 and the fuel carry-in port 31. Therefore, according to this embodiment, the installation of the chute 121 is easy.

[0074] (Layout) Next, the layout of the boiler unit 2 and the fuel supply side device group 5 will be described. In the combustion system 1 of this embodiment, the equipment is arranged so that biomass fuel can be introduced into the fuel storage chamber (fuel storage means) 11 by directly loading the biomass fuel from a bulk truck or dump truck into the loading port 106 of the receiving device 100. In the combustion system 1 of this embodiment, the receiving device 100 is installed on the front side of the housing 10 that constitutes the boiler unit 2. That is, the housing 10 is rectangular in plan view, and the receiving device 100 is arranged parallel to the long side of the housing 10. The feeding hopper 103 of the receiving device 100 is rectangular and parallel to the housing 10. Alternatively, the feeding opening 106 of the feeding hopper 103 is inclined outward with respect to the housing 10.

[0075] The vertical conveying device 101 is located on the side of the receiving device 100. In other words, the starting end of the vertical feeding means 120 is located on the side of the sending means 105 of the receiving device 100. Therefore, the vertical conveying device 101 and the inlet 106 of the input hopper 103 are located at separate positions in the left-right direction as shown in Figures 1, 16, and 18, and there is no overlapping portion. In addition, in this embodiment, since the vertical conveying device 101 is in an inclined position, when viewed from the side, there is little overlap between the vertical conveying device 101 and the inlet 106 of the input hopper 103, as shown in Figures 1, 16, and 19. In other words, since the vertical feeding means 120 extends diagonally upward and rearward relative to the receiving device 100, there is little overlap between the vertical conveying device 101 and the inlet 106 of the input hopper 103 when viewed from the side.

[0076] When biomass fuel is loaded into the loading hopper 103 from a dump truck or the like, the vehicle is parked in front of the casing 10. At this time, the rear edge of the loading platform is positioned directly above the loading hopper 103 and parallel to the loading hopper 103. The loading platform is then tilted to discharge the biomass fuel from the loading platform. Here, in the combustion system 1 of this embodiment, there is little overlap between the vertical conveying device 101 and the loading port 106 of the loading hopper 103 in both the left-right direction and the front-to-back direction relative to the casing 10. Therefore, when the loading platform is tilted, it is unlikely that the loading platform will hit the vertical conveying device 101. This makes it easy to load biomass fuel into the loading hopper 103. In the combustion system 1 of this embodiment, a portion of the receiving device 100 is housed in the pit (recess) 115, so that when biomass fuel is loaded into the loading hopper 103 from a dump truck or the like, the biomass fuel that overflows from the loading hopper 103 falls into the pit (recess) 115 and is less likely to scatter around.

[0077] The vertical feed means 120 employed in this embodiment has a linear structure as shown in the model of FIG. 24(a), and all points are inclined at the same angle. However, depending on the topography of the location where the boiler unit 2 is installed, it may not be possible to connect the receiving device 100 and the housing 10 with a straight vertical feed means 120. In this case, a vertical feeding means 120 appropriate for the terrain will be used. As described above, in the combustion system 1 of this embodiment, biomass fuel is directly input from a bulk vehicle or a dump truck. Therefore, for example, when the bed of the dump truck is tilted, it is necessary to position the longitudinal feeding means 120 so that the bed of the dump truck can be prevented from coming into contact with the longitudinal feeding means 120. In this case too, a vertical transport means 120 will be used according to the method of receiving the biomass fuel. For these reasons, a configuration may be adopted in which a horizontal conveying section 152 is provided between two inclined conveying sections 150 and 151, as shown in FIG. 24(b). 24(c), the vertical feed means 120 may be connected to the front side of the housing 10. In FIG. 24(d), the vertical feed means 120 may be connected to the front side of the housing 10 by a short inclined conveying section 153 and a long horizontal conveying section 152. In either case, a fixture 130 can be used that can select a specific mounting hole 133 from a plurality of mounting holes 133. Also, a deformable chute 121 can be used.

[0078] In the embodiment described above, a screw conveyor is used as the vertical feeding means 120. The vertical feeding means 120 is not limited to a screw conveyor, and may be a belt conveyor or a bucket conveyor. It may also be a piston-shaped conveyor that pushes up the biomass fuel.

[0079] (Transportation route for biomass fuel) The fuel supply side device group 5 is made up of a receiving device 100 and a vertical conveying device 101. In this embodiment, the receiving device 100 and the vertical conveying device 101 are installed adjacent to each other. The receiving device 100 is composed of a charging hopper 103 and a sending means 105, and the vertical conveying device 101 is composed of a vertical feeding means 120 and a chute 121.

[0080] In the combustion system 1 of this embodiment, the input hopper 103 is connected to the discharge means 105, an end (side) of the discharge means 105 is connected to the vertical feed means 120, and an end of the vertical feed means 120 is connected to the fuel inlet 31 of the casing 10 via a chute 121. The fuel inlet 31 opens into the fuel storage chamber 11. That is, in this embodiment, the input port 106 of the input hopper 103 is connected to the vertical feed means 120 via the discharge means 105, and further connected to the fuel inlet 31 of the casing 10 via the vertical feed means 120 and the chute 121. In this manner, in this embodiment, the receiving device 100 and the vertical conveying device 101 constitute an introduction means having a series of fuel transport paths from the input port 106 to the fuel inlet 31 of the casing 10, and biomass fuel transported from the outside via this fuel transport path is transported into the fuel storage chamber (fuel storage means) 11 of the boiler unit 2.

[0081] Biomass fuel is transported from outside the combustion system 1 by a bulk vehicle, dump truck, or the like, and is directly loaded from the bulk vehicle, dump truck, or the like into the loading hopper 103. For example, the biomass fuel is loaded onto the bed of a dump truck and brought into the premises of the combustion system from outside. The dump truck is then stopped in front of the input hopper 103, the loading platform is tilted to slide the loaded biomass fuel off, and the loading platform directly deposits the biomass fuel into the input port 106 of the input hopper 103. The biomass fuel input into the input port 106 slides down the inclined surface of the input hopper 103 and enters the delivery means 105. The introduced biomass fuel is then transported horizontally by the delivery means 105 and introduced into the vertical transport means 120. The biomass fuel is transported diagonally upward by the vertical transport means 120, reaches the end, falls into the chute 121, is introduced into the fuel storage chamber 11, and accumulates in the fuel storage space 37.

[0082] The interior of the housing 10 is divided into a fuel storage chamber 11 and a combustion means arrangement chamber 12. The fuel storage chamber 11 is divided into upper and lower sections by a bottom plate 35, and the area above the bottom plate 35 functions as a fuel storage space 37, with biomass fuel collecting on the bottom plate 35. A communication section (fuel supply means) 53 is provided in the bottom plate 35. In this embodiment, a bottom space 51 is provided below the bottom plate 35. A supply conveyor (fuel supply means) 16 is provided within the housing 10, spanning between the fuel storage chamber 11 and the combustion means arrangement chamber 12. The starting end of the supply conveyor 16 is located in the bottom space 51 of the fuel storage chamber 11, directly below the communication part 53 of the bottom plate 35. The end of the supply conveyor 16 is connected to a fuel supply port 77 of the boiler 15.

[0083] The biomass fuel in the fuel storage space 37 is stirred by the stirring member 50 near the bottom plate 35, and then sequentially enters the supply conveyor 16 below through the communication part 53 provided in the bottom plate 35. The biomass fuel is then transported by the supply conveyor 16 to the boiler 15 where it is burned.

[0084] The biomass fuel used in the combustion system 1 of this embodiment is mainly wood chips, and waste materials from demolished houses may also be used as biomass fuel. Here, metal pieces such as old nails, screws, metal fittings, and wire may be mixed in with the waste materials from houses, and these metal pieces may still be mixed in even after they have been chipped. Furthermore, if metal pieces are mixed in the biomass fuel, there is a concern that they may damage the boiler 15.

[0085] To address this issue, in the combustion system 1 of this embodiment, an electromagnet 81 is attached to the middle of the supply conveyor 16. Therefore, if iron pieces such as old nails or wires are mixed in with the biomass fuel, the iron pieces are attracted to the electromagnet 81 and removed, preventing them from entering the boiler 15. In this embodiment, a magnetic attraction amount detecting means 82 is provided. The amount of metal attracted to the electromagnet 81 can be determined by this. In the combustion system 1 of this embodiment, a signal from the magnetic attraction amount detection means 82 is input to a control device (not shown). When the amount of metal attracted to the electromagnet 81 exceeds a certain amount, a predetermined message appears on a display device (not shown), and an automatic discharge mechanism is activated to automatically discharge the accumulated metal to the outside. Alternatively, the operator can know from this display that the amount of metal attracted to the electromagnet 81 has exceeded a certain amount, and can manually remove the accumulated metal pieces. When the amount of metal attracted to the electromagnet 81 further increases, the supply conveyor stopping means is activated to forcibly stop the supply conveyor 16, thereby preventing metal pieces from entering the boiler 15. If the amount of metal attracted to the electromagnet 81 increases further, the automatic boiler stop means will function to automatically stop the boiler 15, thereby preventing breakdown of the boiler 15.

[0086] (ventilated environment) Next, the ventilation environment inside the housing 10 will be described. As described above, the boiler unit 2 is provided with a plurality of fans and ventilation ducts. These primarily serve to introduce warm, dry air from the combustion means arrangement chamber 12 into the fuel storage chamber 11 to promote drying of the biomass fuel. That is, a boiler 15 is installed in the combustion means arrangement chamber 12. Air necessary for combustion is supplied to the boiler 15 from outside the housing 10 by a fan (not shown), and exhaust gas is exhausted to the outside of the housing 10 through the exhaust pipe 17 shown in FIG. 1. In this way, the air necessary for combustion is taken in from outside and the exhaust gas is exhausted to the outside of the housing 10, so the air inside the housing 10 is not used for combustion, and exhaust gas does not accumulate inside the housing 10. However, since the boiler 15 is a combustion means in which biomass fuel is burned, the temperature of the outer surface of the boiler 15 is higher than the outside temperature, which warms the air in the combustion means installation chamber 12, and as the temperature rises, the humidity decreases. Therefore, the air in the combustion means arrangement chamber 12 is in a state suitable for drying things. In the combustion system 1 of this embodiment, the air in the combustion means arrangement chamber 12 is introduced into the fuel storage chamber 11 by the ventilation means, thereby reducing the moisture content of the biomass fuel.

[0087] 3, in this embodiment, a fuel storage ventilation fan (exhaust means) 85 is provided on the upper side of the fuel storage chamber 11 of the boiler unit 2. Furthermore, an internal ventilation passage (ventilation means) 88 connecting the combustion means arrangement chamber 12 and the fuel storage chamber 11 is provided in the partition wall 32 of the housing 10, and the combustion means arrangement chamber 12 and the bottom space 51 of the fuel storage chamber 11 communicate with each other via the internal ventilation passage 88. Furthermore, an outside air intake (outside air introduction port) 83 is provided on the bottom wall 28 of the combustion means arrangement chamber 12.

[0088] In the above-described configuration, when the fuel storage ventilation fan 85 on the upper side of the fuel storage chamber 11 is started, the air inside the fuel storage chamber 11 is exhausted, causing the upper side to tend to become negative pressure, and warm, low-humidity air is introduced from the combustion means arrangement chamber 12 into the bottom space 51 of the fuel storage chamber 11 via the internal ventilation passage (ventilation means) 88. In this embodiment, a large number of small holes 52 are provided in the bottom plate 35 of the fuel storage space 37 , and the small holes 52 ensure ventilation between the bottom space 51 and the fuel storage space 37 . Therefore, the air introduced from the combustion means arrangement chamber 12 into the bottom space 51 of the fuel storage chamber 11 enters the fuel storage space 37 through the small holes 52 in the bottom plate 35 of the fuel storage space 37, comes into contact with the biomass fuel, and reduces the moisture content of the biomass fuel. As a modified example, as described above, it is also possible to connect the combustion means arrangement chamber 12 and the fuel storage space 37, which is the upper space of the fuel storage chamber 11, via an internal ventilation passage (ventilation means). Even in this case, the moisture content of the biomass fuel can be reduced by exposing the biomass fuel in the fuel storage space 37 to low-humidity air.

[0089] When wood chips are heated, moisture contained in the wood chips, such as sap and tar, may rise to the surface. In the biomass combustion system 1 of this embodiment, the inner surface of the fuel storage chamber 11 is covered with wood, which has a certain degree of hygroscopicity. Therefore, the wood lining absorbs moisture that leaks out from the biomass fuel, accelerating the drying of the biomass fuel. As described above, the small holes 52 in the bottom plate 35 are of a size that does not allow the biomass fuel to pass through, so the biomass fuel will not fall into the bottom space 51.

[0090] In the biomass combustion system 1 of this embodiment, dry air is passed through the biomass fuel from the bottom of the fuel storage space 37, and the biomass fuel is agitated by the agitator 50. Therefore, due to the synergistic effect of these factors, dry air is evenly distributed over the biomass fuel in the fuel storage space 37, reducing the moisture content of all the biomass fuel.

[0091] In this embodiment, the biomass fuel is supplied from above the fuel storage space 37 and extracted from below the fuel storage space 37 for combustion. Therefore, the lower the biomass fuel is in the fuel storage space 37, the longer the residence time and the drier it becomes. That is, in the biomass combustion system of this embodiment, biomass fuel is stored in the fuel storage space 37, and warm air is supplied from the lower part of the fuel storage space 37. Although the biomass fuel is agitated, the lower part of the fuel storage space 37 has a low moisture content, while the biomass fuel in the upper part has a high moisture content. In this embodiment, dry air is supplied from the bottom of the fuel storage space 37. Therefore, the biomass fuel at the bottom of the fuel storage space 37 has more opportunities to come into contact with fresh, dry air, and dries faster than the fuel in other areas. That is, in the biomass combustion system of this embodiment, warm air is supplied from the lower part of the fuel storage space 37. The biomass fuel in the lower part of the fuel storage space 37 comes into contact with fresh warm air, so the amount of dehydration per unit time is large, and the moisture content is particularly low. Therefore, when the distribution of moisture content in the fuel storage space 37 is viewed macroscopically, the moisture content of the biomass fuel near the bottom plate 35 of the fuel storage space 37 is lowest.

[0092] On the other hand, biomass fuel is extracted from the bottom of the fuel storage space 37 and transported to the boiler 15. Therefore, just before being used for combustion, the biomass fuel is actively dehydrated by coming into contact with dry, fresh hot air, and the biomass fuel that has been dried most rapidly is preferentially supplied to the boiler 15 and burned. The biomass combustion system 1 of this embodiment is efficient because the drying of the biomass fuel progresses rapidly immediately before it is burned. In the biomass combustion system 1 of this embodiment, the biomass fuel in the fuel storage space 37 is dried, and the dried biomass fuel is preferentially supplied to the boiler 15. The biomass combustion system 1 of this embodiment dries and burns the biomass fuel in parallel. This is therefore more efficient than a configuration in which all biomass fuel is dried before being supplied to the boiler 15. In other words, it is possible to reduce the time required just to dry the biomass fuel, and it is also possible to reduce the downtime and preparation time of the boiler 15.

[0093] In this embodiment, an outside air intake (outside air introduction port) 83 is provided at the bottom of the combustion means arrangement chamber 12, and outside air is taken in from the bottom of the combustion means arrangement chamber 12 to prevent the inside of the combustion means arrangement chamber 12 from becoming negative pressure, and the warm air inside the combustion means arrangement chamber 12 is drawn by the negative pressure of the fuel storage chamber 11 and flows into the fuel storage chamber 11. However, the position of the outside air intake (outside air introduction port) 83 is not limited to the bottom of the combustion means arrangement chamber 12, and may be on the upper side of the combustion means arrangement chamber 12, for example. When an outside air intake (outside air introduction port) 83 is provided on the upper side of the combustion means arrangement chamber 12, the air in the combustion means arrangement chamber 12 is stirred, and the relatively high temperature air in the combustion means arrangement chamber 12 is introduced into the fuel storage chamber 11 through an internal ventilation passage (ventilation means) 88 provided at the bottom.

[0094] (Fuel Drying System 8) The combustion system 1 of this embodiment has heated air supply means 43 that supplies heated air to the fuel storage space 37, and is equipped with a fuel drying system 8 that reduces the moisture content of the biomass fuel in the fuel storage space 37 using the heated air supply means 43. In this embodiment, air is heated using heat stored in the heat storage tank 7, and is blown into the fuel storage space 37 by a blower 198. In the combustion system 1 of this embodiment, as shown in Figs. 1 and 25, a heat storage tank 7 is installed near the housing 10. Water is stored in the heat storage tank 7 as a primary heat medium (first heat medium). The water is used as the primary heat medium (first heat medium) and is not directly supplied as water. The heat storage tank 7 is connected to a boiler 15 in the housing 10 by piping, and the boiler 15 heats and raises the temperature of a primary heat medium (first heat medium). In this embodiment, a first heat exchanger 161 is built into the heat storage tank 7. The first heat exchanger 161 is, for example, a coiled pipe. A secondary heat medium (second heat medium) passes through the first heat exchanger 161, and the temperature of the secondary heat medium is increased. A temperature sensor (temperature detection means) 163 is attached to the heat storage tank 7. The temperature sensor 163 detects the temperature of the primary heat medium (first heat medium) in the heat storage tank 7.

[0095] The heat storage tank 7 is primarily used to store heat for hot water supply, but in the combustion system 1 of this embodiment, it is also used to dry the biomass fuel stored in the boiler unit 2. The fuel drying system 8 has a heated air supply means 43 constituted by a heat storage tank 7, a gas-liquid heat exchanger 178, and a ventilation means 188, as shown in FIGS. The gas-liquid heat exchanger 178 has a primary flow path 191 through which a heat medium passes inside a casing 190, and raises the temperature of the air passing through by ventilating the inside of the casing 190 and exposing it to the draft. In this embodiment, the first heat exchanger 161 in the heat storage tank 7 and the primary flow path 191 of the gas-liquid heat exchanger 178 are connected by a heat medium pipe 192, and a secondary side heat medium (second heat medium) is supplied from the first heat exchanger 161 in the heat storage tank 7 to the primary flow path 191 of the gas-liquid heat exchanger 178 by a pump 193.

[0096] The ventilation means 188 is composed of a blower 198 and a ventilation duct 195. The blower 198 creates a ventilated environment inside the casing 190 of the gas-liquid heat exchanger 178 to generate warm air. In this embodiment, the ventilation duct 195 connects the air outlet side of the gas-liquid heat exchanger 178 to the bottom space 51 of the fuel storage chamber 11.

[0097] Next, the function of the fuel drying system 8 will be described. The main component of the fuel drying system 8 is the heated air supply means 43, which is driven by the system. Specifically, the secondary heat medium (second heat medium) is passed through the primary flow path 191 of the gas-liquid heat exchanger 178, and the blower 198 is started. As a result, hot air is generated in the gas-liquid heat exchanger 178, and the hot air is forcibly supplied to the bottom space 51 of the fuel storage chamber 11 via the air supply duct 195. Specifically, air heated by the heated air supply means 43 is supplied to the fuel storage chamber 11. As a result, the bottom space 51 of the fuel storage chamber 11 becomes positively pressurized, and the heated air generated in the gas-liquid heat exchanger 178 enters the fuel storage space 37 through the small holes 52 in the bottom plate 35 of the fuel storage space 37, comes into contact with the biomass fuel, and dries the biomass fuel.

[0098] In the above-described configuration, dried air that has been heated by the heated air supply means 43 is forcibly supplied from the bottom of the fuel storage space 37, so that the dried air is evenly distributed over the biomass fuel in the fuel storage space 37. Furthermore, the dried air is supplied intensively to the biomass fuel immediately before it is burned, so that the biomass fuel is exposed to high-temperature air and dried immediately before it is burned, resulting in high efficiency. That is, in the fuel drying system 8, the heated air is supplied from the bottom of the fuel storage space 37 by the heated air supply means 43. Therefore, the dry air has many opportunities to come into contact with the biomass fuel, particularly at the bottom of the fuel storage space 37, and dries quickly. As a result, the biomass fuel at the bottom of the fuel storage space 37 has a lower moisture content than that in other areas. Even when the fuel drying system 8 is used, it is possible to supply the dried biomass fuel preferentially to the boiler 15. The fuel drying system 8 dries and burns the biomass fuel in parallel using the heated air supply means 43. This makes it more efficient than a configuration in which all biomass fuel is dried before being supplied to the boiler 15. In other words, even when the fuel drying system 8 is used, it is possible to reduce the time required just to dry the biomass fuel, thereby reducing the downtime and preparation time of the boiler 15.

[0099] In the embodiment described above, hot air is generated using the heat stored in the heat storage tank 7, but the heated air supply means may also generate hot air using other thermal energy derived from the boiler 15. For example, the heated air supply means may extract thermal energy from the exhaust gas of the boiler 15 and heat the air with that thermal energy. Alternatively, the heated air supply means may heat the air using a completely different heat source. For example, hot air may be generated using electricity or gas, pressurized by a blower, and introduced into the fuel storage chamber 11.

[0100] As one of the measures for utilizing the heat derived from the boiler 15, a heated air supply means having a configuration as shown in Fig. 26 can be considered. In the embodiment shown in Fig. 26, an external ventilation passage (ventilation means) 196 is provided that bypasses the housing 10 and connects the combustion means arrangement chamber 12 and the fuel storage chamber 11, and a blower 197 is provided in the external ventilation passage 196 to introduce the warm air from the fuel storage chamber 11 into the fuel storage chamber 11. In this embodiment, the external ventilation passage 196 is connected to a high position of the combustion means arrangement chamber 12 and takes air out of the combustion means arrangement chamber 12. The external ventilation passage 196 is also connected to the bottom space 51 of the fuel storage chamber 11.

[0101] In each figure, a model of the blower is shown. The illustrated blower is an axial flow blower, but because air needs to be forced through the biomass fuel, it is desirable to select a blower with a structure that can generate higher static pressure. For example, it is desirable to use a centrifugal blower such as a sirocco fan or turbo fan.

[0102] (Separate type) In the combustion system 1 of the embodiments described above, an integrated boiler unit 2 is adopted in which a fuel tank (fuel storage chamber 11) for storing biomass fuel and a boiler 15 are incorporated into a single housing 10, but a structure in which the fuel tank and boiler 15 are separate is also possible. 27 and 28 show a separate type combustion system 200. The separate type combustion system 200 has a housing 201 that serves as the fuel storage chamber (fuel storage means) 11, and a housing 202 that serves as the combustion means arrangement chamber 12. A supply conveyor (fuel supply means) 16 is stretched between the two housings 201 and 202. The fuel storage chamber 11 is the same as that of the integrated combustion system 1, and is divided into upper and lower sections by a bottom plate 35, and the area above the bottom plate 35 functions as a fuel storage space 37.

[0103] The separate type combustion system 200 also has a fuel supply side device group (not shown), and the biomass fuel is introduced into the fuel containing space 37 by the fuel supply side device group. In the separate type combustion system 200, the vertical conveying device 101 is installed in a housing 201 which serves as the fuel storage chamber (fuel storage means) 11. The middle part of the vertical feeding means 120 is connected to the housing 201 via a fixing tool 130 and an auxiliary metal fitting 131 (not shown). The combustion means arrangement chamber 12 is also the same as that of the integrated combustion system 1, and a boiler 15 is installed therein.

[0104] In the integrated combustion system 1, an internal ventilation passage 88 connecting the combustion means arrangement chamber 12 and the fuel storage chamber 11 was provided inside the housing 10, but in the separate type combustion system 200, an external ventilation passage (ventilation means) 205 is installed as an alternative ventilation passage. The external ventilation passage 205 is a conduit made of pipes or ducts, and connects the combustion means arrangement chamber 12 in the housing 202 with the bottom space 51 of the fuel storage chamber 11 in the housing 201 .

[0105] As described above, in the separate type combustion system 200, when the fuel storage ventilation fan (exhaust means) 85 on the upper side of the fuel storage chamber 11 is started, air is exhausted from the upper side of the fuel storage chamber 11, causing the upper side of the fuel storage chamber 11 to tend to become negative pressure, and warm, low-humidity air is introduced from the combustion means arrangement chamber 12 into the bottom space 51 of the fuel storage chamber 11 via the external ventilation path (ventilation means) 205. The air introduced from the combustion means arrangement chamber 12 enters the fuel storage space 37 through the small holes 52 in the bottom plate 35 of the fuel storage space 37, and comes into contact with the biomass fuel to dry it.

[0106] The combustion system 200 also includes a fuel drying system 206 . The heated air supply means 207 of the fuel drying system 206 is composed of a fan heater 208 and a ventilation means 210 . Fan heater 208 is an integrated unit of an electric heater or oil heater and a blower, and emits heated air. Ventilation means 210 is a conduit made of pipes or ducts, and connects fan heater 208 to bottom space 51 of fuel storage chamber 11 inside housing 201. When the fan heater 208 of the heated air supply means 207 is activated, high-temperature air is generated, and the high-temperature air is forcibly supplied to the bottom space 51 of the fuel storage chamber 11 via the ventilation means 210.

[0107] (Other accessories) It is desirable to have an inventory checking means for monitoring the remaining amount of biomass fuel in the fuel storage chamber 11. For example, an infrared sensor or a monitoring camera may be installed in the fuel storage chamber 11. Alternatively, a weight sensor may be installed to detect the inventory of biomass fuel by weight. It is desirable to provide a notification means that notifies the manager when the biomass fuel inventory falls below a certain level. It is also possible to automatically notify the biomass fuel supplier when the biomass fuel inventory falls below a certain level.

[0108] (Other variations) In the combustion systems 1 and 200 described above, the bottom plate 35 (bottom) installed in the fuel chamber 11 is inclined, but the present invention is not limited to this configuration, and the bottom plate 35 may be in a horizontal position. In the combustion systems 1 and 200 described above, the bottom plate 35 has a communication section 53 through which biomass fuel is dropped, and the communication section 53 is a rectangular opening provided near the partition wall 32. However, the present invention is not limited to this configuration, and the shape and number of the communication sections 53 are arbitrary.

[0109] In the fuel storage chamber 11 shown in FIG. 29, the bottom plate 211 is in a horizontal position, and a plurality of circular holes 212 are formed as communication sections along the housing 215 of the supply conveyor 16 below. In the fuel storage chamber 11 shown in Figure 30, a bottom plate 211 and a housing 216 of a supply conveyor 16 are integrated together. That is, a groove 217 is formed in the bottom plate 211, and a screw 218 is disposed in the groove 217. In the fuel storage chamber 11 shown in Figure 30, the groove 217 in the bottom plate 211 functions as a communication part. Also, a separate supply conveyor 16 may be connected below the groove 217 shown in FIG. 30, and the groove 217 may be used as a feeding hopper.

[0110] In the combustion system 1 described above, the biomass fuel and the boiler 15 are housed in the housing 10, and the heat storage tank 7 is placed outside. However, the heat storage tank 7 may be installed inside the housing 10.

[0111] In the combustion system 1 described above, an electromagnet 81 is attached to the supply conveyor 16 to remove metals. The supply conveyor 16 is the final part of the biomass fuel supply path and is located just before the boiler 15, making it a preferable location for preventing metals from entering the boiler 15. However, the present invention is not limited to this configuration, and the electromagnet 81 may be attached in another position. That is, an electromagnet may be provided in the supply path that supplies biomass fuel to the fuel storage chamber 11, or inside or on the outer wall of the fuel storage chamber 11, and metal may be removed each time. The electromagnet may also be provided in a position near the fuel storage chamber 11 where it can exert a magnetic force on the interior of the fuel storage chamber 11. For example, an electromagnet may be provided in the receiving device 100 that receives biomass fuel. For example, an electromagnet may be provided in the input hopper 103 or the delivery means 105. Alternatively, an electromagnet may be provided in the vertical feed means 120. If an electromagnet is provided at the connection between the delivery means 105 and the vertical feed means 120, it becomes easier to remove the collected metals.

[0112] When an electromagnet is provided in the fuel storage chamber 11, it is desirable to install it on the inner wall of the fuel storage chamber 11. Although it is not intended to deny the provision of an electromagnet on the bottom plate 35, in this embodiment, since the agitating member 50 passes over the bottom plate 35, measures for the agitating member 50 are necessary. An electromagnet may be attached to the stirring member 50. When attaching an electromagnet to the stirring member 50, attaching the electromagnet to a location with little movement has the advantage of making it easier to hold the magnetized metal. Attaching the electromagnet to a location with more movement has the advantage of increasing the chances of contact with the metal and making it easier to collect the metal. An electromagnet may be provided in the communication portion 53 provided in the bottom plate 35 of the fuel storage chamber 11 . A permanent magnet can be used instead of an electromagnet. In this embodiment, the term "electromagnet" is a general term for a component that generates magnetic force using electricity, and it does not matter whether it has a core or not. A superconducting magnet is also a type of electromagnet.

[0113] (Consumption side equipment group 6 and hot water supply system 18) Next, the consumer-side device group 6 will be described. The combustion systems 1, 200 of this embodiment burn biomass fuel in a boiler 15 to obtain thermal energy, and can use this thermal energy to supply hot water. In other words, the combustion systems 1, 200 incorporate a hot water supply system 18. In this embodiment, the hot water supply system 18 is constructed by the boiler unit 2 and the consumer-side device group 6. Hereinafter, hot water supply that is performed by burning biomass fuel to obtain thermal energy and utilizing that thermal energy will be referred to as specific hot water supply. The consumption side device group 6 employed in this embodiment has an equipment layout as shown in FIG. 31, for example, and is a hot water supply pipe 160 as shown in FIG.

[0114] In the combustion system 1 (hot water supply system 18) of this embodiment, a heat storage tank 7 is used, and the first heat exchanger 161 heats the secondary side heat medium (second heat medium) of the secondary circuit 162 from the primary side heat medium (first heat medium) of the heat storage tank 7, and the second heat exchanger 165 heats city water passing through the tertiary circuit 166 from the secondary side heat medium (second heat medium) of the secondary circuit 162, so that hot water can be supplied from the hot water tap (consumption destination) 157, etc. That is, in this embodiment, a specific hot water generating means 155 is constructed using a boiler 15, a heat storage tank 7, a first heat exchanger 161, a secondary circuit 162, a second heat exchanger 165, and a tertiary circuit 166 to generate hot water using thermal energy obtained by burning biomass fuel. A primary heat medium (first heat medium) is stored in the heat storage tank 7 of the specific hot water generating means 155, a secondary heat medium flows in the secondary circuit 162, and city water flows in the tertiary circuit 166. In addition, a water heater 167 that produces hot water using other thermal energy is connected to the tertiary circuit 166, and hot water can also be supplied using the water heater 167. Hereinafter, hot water supply using the water heater 167 will be referred to as general hot water supply. In the hot water supply system 18 of this embodiment, it is possible to automatically switch between the specific hot water supply and the general hot water supply depending on the status of the specific hot water generating means 155.

[0115] As described above, in the combustion systems 1, 200 of the present embodiment, the heat storage tank 7 is installed near the housing 10. The heat storage tank 7 contains a primary heat medium (first heat medium). The primary heat medium (first heat medium) in the heat storage tank 7 is heated by the boiler 15. In this embodiment, a first heat exchanger 161 is built into the heat storage tank .

[0116] The secondary circuit 162 connects the heat storage tank 7 and the second heat exchanger 165. That is, the secondary circuit 162 is connected to both the heat storage tank 7 and the second heat exchanger 165. In detail, the secondary circuit 162, which is a component of the hot water supply system 18, is made up of a coiled pipe of the heat storage tank 7, which is the first heat exchanger 161, a primary side flow path 170 of the second heat exchanger 165, a circulation pipe 171 that connects these in a ring shape, and a pump 172, as shown in FIG. 32 . A secondary side heat medium (second heat medium) is built in the secondary circuit 162, and the secondary side heat medium circulates within the secondary circuit 162. The tertiary circuit 166, which is a component of the hot water supply system 18, is made up of a circulation flow path 175 and a branch flow path 176 as shown in FIG. The circulation flow path 175 is a circulation flow path that connects a water inlet 180 and a water outlet 181 of a secondary side flow path 177 of the second heat exchanger 165, and has a circulation pump 182 provided midway. The circulation flow path 175 has a city water inlet 183, where city water is pressurized by a pump (not shown) and introduced. A check valve 185 is provided in the city water inlet. The circulation flow path 175 includes a secondary side flow path 177 of the second heat exchanger 165, and clean water circulates through the secondary side flow path 177 of the second heat exchanger 165. Therefore, hot water that has been heated in the secondary side flow path 177 of the second heat exchanger 165 and is maintained at a constant temperature circulates through the circulation flow path 175.

[0117] Furthermore, a branch flow path 176 branches off from the circulation flow path 175. The branch flow path 176 is connected to the hot water tap 157 via a switching means 186. The switching means 186 is a valve that is switched by power such as a solenoid valve or a motor valve. In this embodiment, a three-way switching valve is used as the switching means 186. A water heater 167 is connected to one port of the switching means 186. The water heater 167 uses electricity, gas, oil, or the like as a heat source. The water heater 167 is a general hot water generating means that generates hot water using thermal energy derived from sources other than biomass fuel. A flow meter 187 is attached to the branch flow path 176 upstream of the switching means 186 .

[0118] The switching means 186 is automatically switched by the control device depending on the state of the specific hot water generating means 155. In this embodiment, the switching means 186 in the heat storage tank 7 is switched depending on the temperature of the primary side heat medium inside. As described above, a temperature sensor 163 that detects the temperature of the primary heat medium (first heat medium) inside the heat storage tank 7 is attached to the heat storage tank 7. A signal from the temperature sensor 163 is input to a control device (not shown), which monitors the temperature of the primary heat medium (first heat medium). In this embodiment, the switching means 186 is controlled by a control device (not shown). Specifically, the temperature of the primary heat medium (first heat medium) in the heat storage tank 7 is monitored, and if the temperature of the heat medium is equal to or higher than a predetermined temperature, the flow path from the water heater (general hot water generating means) 167 to the hot water tap 157 is blocked, and the circulation flow path 175 and the hot water tap 157 are connected to each other. Conversely, if the temperature of the primary heat medium in the heat storage tank 7 is below the predetermined temperature, the circuit between the circulation flow path 175 and the hot water tap 157 is blocked, and the flow path between the water heater 167 and the hot water tap 157 is opened.

[0119] As described above, the hot water supply pipe 160 of this embodiment has the secondary circuit 162 and the tertiary circuit 166, which are circulation flow paths. In the hot water supply pipe 160 of this embodiment, liquid is constantly circulating through the two circulation pipes. That is, as described above, the secondary circuit 162 is a circulation flow path that connects the coiled piping of the heat storage tank 7 and the primary side flow path 170 of the second heat exchanger 165 with the circulation piping 171, and the secondary side heat medium inside is circulated by driving the pump 172. When the secondary heat medium passes through the coiled piping of the heat storage tank 7, it receives heat from the primary heat medium in the heat storage tank 7 and is heated, thereby increasing in temperature. As described above, the secondary heat medium circulates within the secondary circuit 162, so that the secondary heat medium is maintained at a constant temperature.

[0120] The tertiary circuit 166 is a circulation flow path that connects a water inlet 180 and a water outlet 181 of the secondary side flow path 177 of the second heat exchanger 165, and city water is circulated inside by driving a circulation pump 182. That is, as described above, the tertiary circuit 166 is a circulation flow path connecting the water inlet 180 and water outlet 181 of the secondary side flow path 177 of the second heat exchanger 165, so when the city water inside passes through the secondary side flow path 177 of the second heat exchanger 165, it receives heat from the high-temperature secondary side heat medium flowing through the primary side flow path 170 of the second heat exchanger 165, is heated, and its temperature rises. Therefore, in this embodiment, city water heated to a constant temperature is constantly circulating within the tertiary circuit 166. That is, the circulation flow path 175 of the tertiary circuit 166 is a flow path through which hot water heated in the secondary flow path 177 of the second heat exchanger 165 and maintained at a constant temperature circulates.

[0121] As described above, if the temperature of the primary heat medium in the heat storage tank 7 is equal to or higher than a predetermined temperature, the primary heat medium in the heat storage tank 7 and the secondary heat medium flowing in the secondary circuit 162 exchange heat through the coiled piping of the heat storage tank 7, causing the secondary heat medium to reach a high temperature, and the city water flowing in the tertiary circuit 166 exchanges heat with the city water in the second heat exchanger 165, causing the city water flowing in the tertiary circuit 166 to reach a high temperature. Furthermore, since the temperature of the primary heat medium in the heat storage tank 7 is above a predetermined temperature, the switching means 186 blocks the flow path between the water heater 167 and the hot water tap 157, and connects the circulation flow path 175 and the hot water tap 157. In this state, when hot water tap 157 is opened, high-temperature city water flowing in tertiary circuit 166 flows into branch flow path 176 and hot water is dispensed from hot water tap 157. That is, hot water that has been heated in secondary flow path 177 of second heat exchanger 165 and maintained at a constant temperature circulates in circulation flow path 175 of tertiary circuit 166, so when hot water tap 157 is opened, hot water maintained at a constant temperature is immediately dispensed. In practice, a hot and cold water mixing valve is installed near the hot water tap 157 or in the flow path midway, and the hot water flowing in the tertiary circuit 166 is mixed with room temperature city water to be adjusted to a predetermined temperature before being dispensed.

[0122] On the other hand, if the temperature of the primary heat medium in the heat storage tank 7 is below a predetermined temperature, the switching means 186 switches, blocking the connection between the circulation flow path 175 and the hot water tap 157, and opening the flow path between the water heater 167 and the hot water tap 157. That is, because the temperature of the primary heat medium in the heat storage tank 7 is low, the temperature of the secondary heat medium flowing through the secondary circuit 162 is also low, and the temperature of the city water flowing through the tertiary circuit 166 is also low. Therefore, even if the city water flowing through the tertiary circuit 166 is made to flow hot water, the desired outlet temperature may not be obtained. As described above, when the temperature of the primary heat medium in the heat storage tank 7 is low, the circulation flow path 175 and the hot water tap 157 are blocked, and the flow path between the water heater 167 and the hot water tap 157 is opened. For example, immediately after starting up boiler 15, the temperature of the primary heat medium in heat storage tank 7 is low. In this case, switching means 186 blocks communication between circulation flow path 175 and hot water tap 157, and the flow paths between water heater 167 and hot water tap 157 are open. Therefore, when the hot water tap 157 is opened, hot water produced by the water heater 167 is dispensed from the hot water tap 157 .

[0123] For ease of understanding, only the main components of the hot water supply piping 160 are shown in the diagram, but in reality, it is equipped with components that isolate the tertiary circuit 166 from the city water piping, various sensors, switching valves, etc. Furthermore, in the above-described embodiment, the liquid is constantly circulated in the secondary circuit 162, but the temperature sensor 163 may monitor the temperature of the primary heat medium (first heat medium) in the heat storage tank 7, and the flow of the liquid in the secondary circuit 162 may be interrupted in response to temperature changes. Similarly, the temperature sensor 163 may monitor the temperature of the primary heat medium (first heat medium) in the heat storage tank 7, and the flow of the liquid in the tertiary circuit 166 may be interrupted in response to temperature changes. Furthermore, a hot water discharge signal may be detected, and the pumps 172, 182 may be driven in response to the hot water discharge signal.

[0124] In the embodiment described above, the switching means 186 is automatically switched based on the temperature of the primary heat medium in the heat storage tank 7, but the present invention is not limited to this configuration. As described above, the specific hot water generating means 155 of this embodiment has the boiler 15, the heat storage tank 7, the first heat exchanger 161, the secondary circuit 162, the second heat exchanger 165, and the tertiary circuit 166. In the specific hot water generating means 155, the primary heat medium is stored in the heat storage tank 7, the secondary heat medium flows through the secondary circuit 162, and city water flows through the tertiary circuit 166. Therefore, the switching means 186 may be switched depending on any of these states.

[0125] For example, the flow paths may be switched depending on the temperature of the liquid flowing through each flow path. For example, the temperature of the secondary heat medium flowing through the secondary circuit 162 may be monitored by a sensor, and the switching means 186 may be switched based on that temperature. Similarly, the temperature of city water flowing through the tertiary circuit 166 may be monitored by a sensor, and the switching means 186 may be switched based on that temperature. The switching means 186 may be switched depending on the state of the boiler 15 .

[0126] 31, in the hot water supply system 18 of this embodiment, there are three buildings 300, 301, and 302 near the boiler unit 2, and hot water is supplied to each of the buildings 300, 301, and 302. That is, each of the buildings 300, 301, and 302 has a tertiary circuit 166, and a secondary circuit 162 is connected to the tertiary circuit 166 of each of the buildings 300, 301, and 302.

[0127] The consumption-side device group 6 described above heats a heat medium in the boiler 15, and uses the heat of the heat medium to raise the temperature of city water through several stages of heat exchange to supply hot water, but the number of heat exchanges is optional and may be three or more or less. Alternatively, water in a tank may be heated by the boiler 15, and the hot water may be supplied directly. Alternatively, the heat storage tank 7 may not be provided, and the heat medium heated by the boiler 15 may be passed through the primary side of the heat exchanger to heat the heat medium or hot water flowing through the secondary side of the heat exchanger. In either case, it is desirable to be able to switch between the specific hot water supply and the general hot water supply depending on the status of the specific hot water generating means 155.

[0128] In the hot water supply system 18 of this embodiment, the heat storage tank 7 is used, and thermal energy can be stored in the heat storage tank 7, so that the imbalance between the amount of heat generated and the amount of heat consumed can be eliminated. For example, hot water supply tends to be concentrated in limited time periods. If heat generated by combustion means is used for hot water supply, the amount of heat generated will be insufficient during the time periods when hot water supply is concentrated. Also, there will be excess heat during the time periods when hot water supply is less frequent. In the hot water supply system 18 of this embodiment, a heat storage tank 7 is used, and excess thermal energy is stored in the heat storage tank 7, and heat is extracted from the heat storage tank 7 during times when heat consumption is high. In addition, the hot water supply system 18 of this embodiment is also equipped with a hot water heater 167 that uses heat from gas, oil, etc., so even if the thermal energy stored in the heat storage tank 7 is not enough to supply hot water, hot water at the required temperature and in the required amount can be supplied to the consumer and dispensed. In the embodiment described above, the hot water tap 157 is used as a consumer, but the hot water tap 157 is merely one example of a consumer, and the consumer may also be a bath, shower, heater, or the like.

[0129] In the embodiment described above, the specific hot water supply and the general hot water supply are automatically switched in accordance with the state of the specific hot water generating means 155, but the two may be switched manually. For example, when it is known in advance that the specific hot water generating means 155 cannot be used due to circumstances such as inspection of the boiler 15, the specific hot water supply and the general hot water supply are switched over manually. [Explanation of symbols]

[0130] 1: Biomass combustion system, 2: Boiler unit, 10: Housing, 11: fuel storage chamber, 12: combustion means arrangement chamber, 15: boiler (combustion means), 16: supply conveyor (fuel supply means), 32: partition wall, 35: bottom plate, 37: Fuel storage space, 51: Bottom space, 52: Small hole, 53: Communication part, 83: Outside air intake (outside air intake), 85: Fuel storage ventilation fan (exhaust means), 88: Internal ventilation passage (ventilation means), 196: External ventilation passage (ventilation means),

Claims

1. A biomass combustion system having a fuel storage means for storing biomass fuel and a combustion means for burning the biomass fuel, the fuel storage means has a fuel storage space for storing biomass fuel, the combustion means is disposed in a combustion means arrangement chamber, a vent means for communicating the combustion means arrangement chamber with a fuel storage space, and an exhaust means for exhausting air from the fuel storage space, A biomass combustion system, characterized in that the air in the combustion means arrangement chamber can be introduced into the fuel storage space by exhausting the air in the fuel storage space with the exhaust means.

2. the fuel storage means and the combustion means are in a common housing, the interior of the housing is partitioned to form a fuel storage chamber and a combustion means arrangement chamber, and the fuel storage space is formed in the fuel storage chamber, 2. The biomass combustion system according to claim 1, wherein the partition has an opening that serves as the ventilation means.

3. 2. The biomass combustion system according to claim 1, wherein an outside air inlet is provided at the bottom of the combustion means arrangement chamber.

4. the fuel containing means is within a housing; a bottom space is provided between a bottom of the housing and a bottom of the fuel storage space, and air permeability is ensured between the bottom space and the fuel storage space; 2. The biomass combustion system of claim 1, wherein said vent means is open to said bottom space.

5. The biomass combustion system of claim 4, characterized in that a large number of small holes are provided in the bottom, which ensure ventilation between the bottom space and the fuel storage space, and which are not able to pass through the small holes.

6. a fuel supply means for connecting the fuel storage means and the combustion means and supplying the biomass fuel in the fuel storage means to the combustion means; A biomass combustion system as described in claim 4 or 5, characterized in that one end of the fuel supply means is located in the bottom space, and a communication part is provided at the bottom of the fuel storage space that connects the fuel storage space and the fuel supply means, and the biomass fuel in the fuel storage space enters the fuel supply means through the communication part.

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