JP2017166818A - Fluidized bed combustion furnace - Google Patents

Abstract

An object of the present invention is to provide a fluidized bed combustion furnace capable of reducing wear of a refractory protrusion and extending its life. Refractory projections 10 and 20 projecting from the refractory 6 into the furnace are provided in the middle of the inner surface of the refractory 6 covering the furnace wall 1 forming the combustion chamber 2 from the inside. By making the upper surfaces of the object projections 10 and 20 have flat surfaces 11 and 21, a fluid material reservoir in which the fluid material falling along the refractory 6 is deposited on the flat surfaces 11 and 21 is formed. Then, the fluidized material that falls thereafter is made to collide with the fluidized material in the fluidized material pool and not directly collide with the flat surfaces 11 and 21. [Selection] Figure 1

Description

  The present invention relates to a fluidized bed combustion furnace.

  2. Description of the Related Art Conventionally, there is known a fluidized bed furnace in which fuel such as coal is mixed with a fluidized material such as silica sand and the fuel is combusted while forming a fluidized bed (fluidized bed) in which the fluid flows. In this fluidized bed furnace, the furnace wall forming the combustion chamber is covered with a refractory from the inside in order to prevent the furnace wall from being worn by vigorous stirring and heat of the fluidized material. In such a fluidized bed furnace, a burner for injecting a flame into the furnace is installed through the furnace wall and the refractory.

  Specifically, as described in Non-Patent Document 1 below, a refractory protrusion protruding from the refractory into the furnace is further provided in the middle of the inner surface of the refractory. A burner opening is opened in the object protrusion, and the tip of the burner is configured to enter a through hole that follows the burner opening. Such a refractory projection is generally called a burner tile. Then, as shown in Non-Patent Document 1, this burner tile protrudes toward the furnace inner side so as to face the same direction as the burner arranged downward toward the furnace inner side, and the upper surface of the burner tile descends toward the furnace inner side. The slope is inclined.

“Painting waste incineration technology” issued by Ohm Co., Ltd. on January 25, 1995, 2.4 Fluid waste furnace for incineration of general waste 47, Fig. 2.36

  Here, in the above fluidized bed furnace, the fluidized material repeatedly descends along the refractory covering the furnace wall, so the fluidized material repeatedly contacts (impacts) the burner tile protruding into the furnace. As a result, since the upper surface of the burner tile is worn and the life cannot be extended, improvement is demanded.

  The present invention has been made to solve such problems, and it is possible to reduce the wear of refractory projections such as burner tiles and to improve the service life of the fluidized bed furnace. It is an object of the present invention to provide a fluidized bed combustion furnace.

  A fluidized bed combustion furnace according to the present invention includes a combustion chamber for combusting a raw material while forming a fluidized bed in which the raw material and a fluidized material flow, and the furnace wall forming the combustion chamber is covered with a refractory from the inside, and the refractory A fluidized bed combustion furnace having a refractory projection protruding into the furnace from the refractory in the vertical direction of the inner surface of the refractory, wherein the refractory projection has a fluidized material deposition surface on which the fluidized material is deposited on its upper surface. Have.

  According to such a fluidized bed combustion furnace, a refractory projection protruding from the refractory into the furnace is provided in the middle of the inner surface of the refractory covering the furnace wall forming the combustion chamber from the inside. Since the upper surface of the refractory protrusion is configured to have a fluid deposition surface, a fluid material reservoir is formed on the fluid deposition surface on which the fluid material falling along the refractory deposits. When the fluidized material pool is formed in this way, the fluidized material that subsequently falls does not collide with the fluidized material in the fluidized material pool and directly collide with the fluid deposition surface. Therefore, wear of the refractory projections can be reduced, and the life can be extended.

  Here, the refractory protrusion has a fluidized material deposition surface on the upper surface of the refractory material side, and an inclined surface having a downward slope on the upper surface inside the furnace following the fluidized material deposition surface. When such a configuration is adopted, if the amount of fluidized material deposited on the fluidized material accumulation surface exceeds a certain amount, the fluidized material slides down from the fluid pool, but the fluidized material falling down is The fluidized material can be easily returned to the fluidized bed by actively approaching the center of the furnace according to the inclined surface of the gradient.

  Here, as the refractory projection having the above action, specifically, a refractory projection having a raw material supply port for supplying a raw material into the furnace or a burner having a burner opening is opened. Tiles.

  Moreover, specifically as a raw material which exhibits the said effect | action, coal, biomass, or a waste tire is mentioned.

  According to the present invention as described above, it is possible to provide a fluidized bed combustion furnace capable of reducing wear of the refractory projections and extending the life.

It is a schematic sectional lineblock diagram showing the important section of a fluidized bed combustion furnace concerning an embodiment of the present invention. It is an II-II arrow line view of FIG. It is the enlarged view which looked at the refractory protrusion part for fuel supply in FIG. 1 from the furnace inner side. It is an expanded section lineblock diagram showing the 1st modification and the 2nd modification of a fluidized bed combustion furnace of the present invention.

  Hereinafter, an embodiment of a fluidized bed combustion furnace according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent element, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a schematic cross-sectional view showing the main part of a fluidized bed combustion furnace according to an embodiment of the present invention, FIG. 2 is a view taken along the line II-II in FIG. 1, and FIG. It is the enlarged view which looked at the refractory projection part from the furnace inner side, and this fluidized-bed combustion furnace is a fluidized-bed boiler here, and is used for a power station.

  As shown in FIG. 1, the fluidized bed boiler 100 generally has a rectangular cylindrical furnace whose upper and lower ends are closed, and its lower part narrows in the width direction (left and right direction in FIG. 1) as it goes downward, so that a rectangular cylinder is formed. The shape is reduced. In the fluidized bed boiler 100, the furnace wall 1 is a combustion chamber 2, and a fluidized material such as silica sand is previously stored in the combustion chamber 2 for the purpose of promoting complete combustion, and a plurality of fluidized bed boilers 100 are provided at the bottom of the combustion chamber 2. Combustion air is introduced into the combustion chamber 2 through the opening 3 and fuel such as coal and biomass is introduced into the lower portion of the combustion chamber 2 from the outside, and a fluidized bed is formed while these are flowing to burn the fuel. is there.

  The furnace wall 1 of the fluidized bed boiler 100 is constituted by a so-called membrane panel in which water wall tubes (water pipes) arranged in parallel in the circumferential direction of the furnace wall (left and right in the figure) are connected to each other with flat fins. The refractory 6 is provided so as to cover the membrane panel 1 from the inside. Here, the water wall tube converts heat generated in the combustion chamber 2 into water vapor by exchanging heat with water flowing in the water wall tube, and the refractory 6 is formed of a refractory lining formed of an irregular refractory. Has been.

  In the fluidized bed boiler 100, as shown in FIGS. 1 to 3, the fuel supply refractory protrusion 10 and the burner project from the refractory 6 into the furnace in the middle of the inner surface of the refractory 6 in the vertical direction. A tile 20 is provided. These fuel supply refractory projections 10 and burner tiles 20 are obtained by causing a part of the refractory 6 to bulge (extend) inside the furnace.

  As shown in FIGS. 1 and 3, the fuel supply refractory protrusion 10 is provided with a screw conveyor 4 and supplies fuel from the screw conveyor 4 into the furnace through the fuel supply port 5. Specifically, the fuel supply port 5 is opened inside the furnace, and the tip of the screw conveyor 4 enters from the outside of the furnace into the through hole 7 that passes through the fuel supply port 5 to the outside of the furnace. Installed. Then, by driving the screw conveyor 4, the fuel is conveyed by the screw conveyor 4 and supplied into the furnace through the fuel supply port 5.

  As shown in FIGS. 1 and 2, the burner tile 20 is a refractory projection for installing the burner 8 and for injecting a flame from the burner 8 into the furnace through the burner opening 9. The burner opening 9 is opened inside the furnace, and the burner 8 is installed in the through-hole 13 penetrating to the outside of the furnace following the burner opening 9 so that the tip of the burner 8 enters from the outside of the furnace. Then, by driving the burner 8, a flame is injected into the furnace through the burner opening 9, and the fuel supplied into the furnace by the screw conveyor 4 is combusted.

  Here, particularly in the present embodiment, as shown in FIGS. 1 and 3, the refractory projection 10 for supplying fuel has a flat surface (fluid deposition surface) 11 on the upper surface on the refractory 6 side. In addition, the upper surface inside the furnace following the flat surface 11 is an inclined surface 12 having a downward slope.

  Similarly to the upper surface of the fuel supply refractory projection 10, the burner tile 20 also has a flat surface (fluid deposition surface) 21 on the refractory 6 side as shown in FIGS. 1 and 2. At the same time, the upper surface inside the furnace following the flat surface 21 is an inclined surface 22 having a downward slope.

  According to the fluidized bed boiler 100 having such a configuration, fuel is burned in the combustion chamber 2, and the generated heat is transmitted to the water wall tube to perform heat exchange. The combustion gas generated by the combustion is discharged from the upper part of the furnace to the subsequent stage, and the fluidized material containing ash descends along the refractory 6 covering the membrane panel (furnace wall) 1 and repeats this.

  Here, in the present embodiment, since the refractory projections 10 for fuel supply, which are refractory projections protruding into the furnace from the refractory 6, and the upper surfaces of the burner tiles 20 have flat surfaces 11 and 21, respectively. On the flat surfaces 11 and 21, a fluidized material reservoir in which fluidized material falling along the refractory 6 is deposited is formed. When the fluidized material pool is formed in this way, the fluidized material that subsequently falls does not collide with the fluidized material in the fluidized material pool and directly collide with the flat surfaces 11 and 21. Therefore, according to the present embodiment, wear of the fuel supply refractory protrusion 10 and the burner tile 20 which are refractory protrusions can be reduced, and the life can be extended.

  Further, according to the present embodiment, the fuel supply refractory projection 10 and the burner tile 20 have the flat surfaces 11 and 21 on the upper surface on the refractory 6 side, respectively, and the furnace inner side following the flat surfaces 11 and 21. Since the sloping surfaces 12 and 22 have downward slopes on the upper surface, the amount of fluidized material deposited on the flat surfaces 11 and 21 exceeds a certain amount and the fluidized material slides down from the fluidized material pool. The fluidized material is actively brought to the center side in the furnace according to the inclined surfaces 12 and 22 having the downward slope, and the fluidized material can be easily returned to the fluidized bed.

  Although the present invention has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment. For example, in the above embodiment, the combustion target is a fuel that generates heat. For example, waste for incineration such as waste tires and garbage may be used. In short, any raw material for combustion including fuel and waste may be used. In addition, in this way, when the waste such as waste tires and garbage is burned instead of the fuel as the raw material, the screw conveyor 4 replaces the fuel with the waste as the raw material supply port (the fuel supply port 5). ) To be fed into the furnace.

  Moreover, in the above embodiment, the application to a fluidized bed boiler is described, but it can also be applied to a circulating fluidized bed boiler that is provided with a cyclone and returns ash such as combustion ash and unburned ash to the fluidized bed, Furthermore, the present invention can also be applied to a fluidized bed furnace that does not have a water pipe for heat exchange in the furnace. Applicable to all fluidized bed combustion furnaces.

  Moreover, in the said embodiment, although the flat surfaces 11 and 12 as a fluid material deposition surface of a fluid material pool were horizontal flat surfaces, if it is a shape which can deposit a fluid material, it will be horizontal flat. It is not limited to the surface. As shown in FIG. 4A, the fluidized material deposition surface of the fluidized bed combustion furnace according to the first modification may be a flat surface 11 </ b> A having a downward slope toward the refractory 6. Further, as shown in FIG. 4 (b), the fluidized material volume surface of the fluidized bed combustion furnace according to the second modification may be a concave surface 11B having a curved surface. Further, a part of the fluid material deposition surface may be a horizontal plane, and the other part may be a downward slope plane or a concave surface. According to these fluidized material deposition surfaces, the fluidized material can be reliably deposited, wear of the refractory projections 10 and the burner tile 20 can be reduced, and a longer life can be achieved.

DESCRIPTION OF SYMBOLS 1 ... Membrane panel (furnace wall), 2 ... Combustion chamber, 6 ... Refractory material, 10 ... Refractory protrusion part for fuel supply (refractory protrusion part), 11 ... Fluidized material deposition surface of refractory protrusion part for fuel supply ( Flat surface of the refractory projections), 12 ... inclined surfaces of the refractory projections for supplying fuel (inclined surfaces of the refractory projections), 20 ... burner tiles (refractory projections), 21 ... deposition of fluid material on the burner tiles Surface (flat surface of the refractory protrusion), 22 ... Inclined surface of the burner tile (inclined surface of the refractory protrusion), 100 ... Fluidized bed boiler (fluidized bed combustion furnace).

Claims (4)

A combustion chamber for combusting the raw material while forming a fluidized bed in which the raw material and the fluidized material flow; a furnace wall forming the combustion chamber is covered with a refractory from the inside; and the middle of the inner surface of the refractory in the vertical direction And a fluidized bed combustion furnace having a refractory projection protruding into the furnace from the refractory,
The refractory projection is a fluidized bed combustion furnace having a fluidized material deposition surface on which the fluidized material is deposited on the upper surface thereof.   2. The fluidized bed combustion according to claim 1, wherein the refractory protrusion has the fluidized material deposition surface on an upper surface on the refractory side, and has a downwardly inclined surface on the upper surface inside the furnace following the fluidized material deposition surface. Furnace.   3. The flow according to claim 1, wherein the refractory protrusion is a refractory protrusion having a raw material supply port for supplying a raw material into the furnace or a burner tile having a burner opening. 4. Floor burning furnace.   The fluidized bed combustion furnace according to any one of claims 1 to 3, wherein the raw material is coal, biomass, or waste tires.

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