JP6136338B2 - Boiler equipment - Google Patents

Description

  The present invention relates to a boiler apparatus for pre-drying a hydrated product, particularly low-grade coal such as lignite containing a large amount of water for improving boiler efficiency.

  In recent years, it has been required to use a high moisture content biomass or a water content such as a low grade coal such as a high moisture content lignite as a fuel for a boiler.

  However, when the hydrated material is used as the fuel for the boiler, there is a problem in that the amount of moisture brought into the furnace is large, so that the temperature in the furnace is lowered by the steam evaporated from the hydrated material, and the efficiency of the boiler is lowered.

  For this reason, when using a hydrated product as a fuel for a boiler, a hydrated product drying device is provided between a pulverizer such as a hammer mill and a furnace, and the hydrated product is previously dried by the drying device to remove moisture. It is necessary to supply to the furnace later.

  In Patent Document 1, a low-grade coal drying device indirectly dries low-grade coal by the latent heat of superheated steam, and after removing fine particles from the steam generated by the drying by a dust collector, at least two-stage compression is performed. A configuration in which the steam is pressurized to superheated steam by a multistage compressor having a compressor is disclosed, and latent heat is recovered from the superheated steam with respect to steam during compression between stages of the multistage compressor. A low-grade coal drying system that sprays condensed condensed water as low-temperature water is disclosed.

JP 2011-214812 A

  In view of such a situation, the present invention provides a boiler device that improves boiler efficiency when a hydrated product is used as boiler fuel.

  The present invention is a boiler apparatus comprising a hydrated material drying system for drying hydrated material, and a burner provided on the furnace wall of the furnace and using the dried hydrated material as fuel, the hydrated material drying system comprising: A drying device for drying the water-containing material, a dust collecting device for separating and collecting the powder of the water-containing material in the steam generated from the water-containing material by drying, and the steam from which the powder of the water-containing material has been removed. Pressurizing means for increasing the pressure to superheated steam, fluidized medium supplying means for extracting a part of the steam and supplying it as a fluidized medium to the drying device, and liquefying the hydrated material, and using the superheated steam as a heat source The present invention relates to a boiler device comprising a heating means for drying a hydrated material.

  Further, the present invention relates to the boiler device, wherein the boosting means extracts a part of the steam generated in the boiler device and uses the extracted steam as a drive source.

  Furthermore, the present invention provides the drying device comprising: a drying chamber in which the hydrated material is stored; a hydrated material supply means for supplying the hydrated material from one end of the drying chamber; and a drying device from the other end of the drying chamber. Discharging means for discharging the water-containing material, the heating means provided in the drying chamber, an exhausting means for exhausting steam generated from the water-containing material by heating, and the drying chamber divided into a plurality of drying compartments And a plurality of dividing walls provided so that the drying compartment communicates alternately with the lower portion and the upper portion, and the fluid medium supply means for ejecting the fluid medium from the bottom plate of the drying chamber, The boiler according to the present invention is configured such that the hydrated liquefied material flows while being reversed between the drying compartments at the lower end or the upper end of the dividing wall.

  According to the present invention, there is provided a boiler apparatus comprising a hydrated material drying system for drying hydrated material, and a burner provided on a furnace wall of a furnace and using the dried hydrated material as fuel. Is a drying device for drying the water-containing material, a dust collecting device for separating and collecting the powder of the water-containing material in the vapor generated from the water-containing material by drying, and the powder from which the water-containing material has been removed Pressurizing means for boosting steam to superheated steam, fluidized medium supplying means for extracting a part of the steam and supplying it as a fluidized medium to the drying device, and liquefying the hydrated material, and the superheated steam as a heat source And a heating means for drying the water-containing material, so that a temperature drop in the furnace due to water vapor when a large amount of water is brought into the furnace can be suppressed, and boiler efficiency can be improved. Over drying In the heat generated heat can be effectively utilized by a heat source, there is exhibited an excellent effect that it is possible to improve the drying efficiency of the hydrate.

It is the schematic which shows the boiler apparatus with which the hydrated material drying system which concerns on the Example of this invention is applied. It is the schematic which shows the hydrated material drying system which concerns on the Example of this invention. It is the schematic which shows the drying apparatus applied to the hydrated material drying system which concerns on the Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, referring to FIG. 1, a boiler device 1 to which a hydrated matter drying system according to an embodiment of the present invention is applied will be described.

  In FIG. 1, 2 indicates a furnace of the boiler device 1, and 3 indicates a burner 3 provided on the furnace wall of the furnace 2. The furnace wall of the furnace 2 is provided with a heat transfer tube (not shown) for absorbing radiant heat from the inside of the furnace, and a super heater (superheated steam generation) for heating the generated steam above the furnace 2. 4) is provided.

  In FIG. 1, reference numeral 5 denotes a hydrated material drying system for drying hydrated materials such as biomass and low-grade coal, such as lignite, and when lignite 6 containing moisture is supplied to the hydrated material drying system 5. The hydrated coal drying system 5 dries the lignite 6 and supplies it as the dried lignite 7 to the burner 3.

  By supplying the dry lignite 7 to the burner 3, the dry lignite 7 is burned in the burner 3, and a flame is formed in the furnace 2. The flue gas 8 generated by the combustion is exhausted through the flue 9 while heating the inside of the furnace 2 and exchanging heat with the super heater 4.

  Next, referring to FIG. 2, the hydrated material drying system 5 will be described.

  In FIG. 2, 11 indicates a pulverizer such as a hammer mill for pulverizing the lignite 6 to a predetermined particle size, for example, 2 mm or less, and 12 a drying chamber 10 for drying the pulverized lignite 6 formed therein. 1 shows a drying device.

  A lignite supply line 13 is connected to the upper part of the side wall of the drying chamber 10, the pulverizer 11 is provided in the middle of the lignite supply line 13, and the pulverizer 11 will be described later via the lignite supply line 13. A brown coal hopper 36 is connected. The lignite hopper 36, the pulverizer 11, and the lignite supply line 13 constitute a hydrated material supply means.

  A dust collector 15 is connected to the top plate of the drying chamber 10 via an exhaust line 14 that is an exhaust means, and a brown coal discharge line 16 that is an exhaust means is connected to the lower part of the other side wall of the drying chamber 10. The lignite discharge line 16 is connected to the burner 3. The lignite discharge line 16 is provided with a heat exchanger 17 for cooling the dry lignite 7.

  The bottom plate 18 of the drying chamber 10 is provided with a number of fluid medium supply pipes 21 for introducing a fluid medium such as bubbling steam 19 through holes (not shown). By supplying the bubbling steam 19 to the lignite 6, the lignite powder is floated by the steam and becomes a pseudo-liquid body, and the fluidized bed 22 is formed in the drying chamber 10 by the pseudo-liquid body.

  The dust collector 15 has a function of collecting and separating the powder of the lignite 6 from the steam 23 evaporated from the lignite 6. A powder discharge line 24 is connected to the dust collector 15, and the powder discharge line 24 merges with the lignite discharge line 16. The collected powder is sent to the lignite discharge line 16 via the powder discharge line 24 and further sent to the heat exchanger 17 via the lignite discharge line 16.

  A steam circulation line 25 is connected to the dust collector 15, the steam circulation line 25 is connected to the fluid medium supply pipe 21, and a blower 26 is provided in the middle of the steam circulation line 25. A part of the steam 23 from which the powder of the lignite 6 has been removed by the dust collector 15 is fed to the fluid medium supply pipe 21 as the bubbling steam 19 by the blower 26. The fluid medium supply pipe 21, the steam circulation line 25, and the blower 26 constitute fluid medium supply means.

  The steam circulation line 25 is branched to a superheated steam introduction line 27 between the dust collector 15 and the blower 26. The superheated steam introduction line 27 is provided with a boosting means, for example, a steam-driven compressor 28, and a part of the steam is extracted from a turbine of a boiler (not shown) and introduced as drive steam through a drive steam introduction line 29. It has become like that. The compressor 28 is driven using the driving steam as a power source, and the steam 23 sucked from the steam circulation line 25 is heated to a higher pressure.

  The downstream end of the superheated steam introduction line 27 is connected to one end of a heat transfer tube 31 (only one is shown in FIG. 2) which is a heating means provided in the fluidized bed 22. In the heat transfer pipe 31, superheated steam that has been heated up by the compressor 28 and has become high-temperature and high-pressure flows.

  A drain pipe 32 is connected to the other end of the heat transfer pipe 31. Superheated steam circulates in the heat transfer pipe 31, condenses by heat exchange with the lignite 6 in the fluidized bed 22, and releases latent heat of condensation. The condensed condensed water is discharged from the drain pipe 32. The drain pipe 32 is connected to a condenser such as a condenser (not shown), and the condensed water is returned to the boiler.

  The steam circulation line 25 and the superheated steam introduction line 27 are connected to a starter steam introduction line 33 that is bifurcated. The startup steam introduction line 33 can extract a part of the steam from the turbine of another operating boiler, supplies a part of the extracted steam to the steam circulation line 25 as the bubbling steam 19 and extracts the steam. The remaining steam is supplied to the superheated steam introduction line 27 as superheated steam.

  Valves 34 and 35 are provided on the bubbling steam side startup steam introduction line 33a connected to the steam circulation line 25 and the superheated steam side startup steam introduction line 33b connected to the superheated steam introduction line 27, respectively. Thus, supply and stop of steam to the steam circulation line 25 and the superheated steam introduction line 27 can be controlled individually.

  Next, the details of the drying device 12 will be described with reference to FIG. In FIG. 3, the heat transfer tube 31 is provided only on the upper part of the fluidized bed 22, but the heat transfer tube 31 is also provided on the middle and lower parts of the fluidized bed 22.

  3, reference numeral 36 denotes a lignite hopper for storing the lignite 6 pulverized by the pulverizer 11 (see FIG. 2), and the lignite is supplied from the lignite hopper 36 to the drying chamber 10 through the lignite supply line 13. 6 is supplied. In addition, the opening position with respect to the said drying chamber 10 of the said lignite supply line 13 is located above the opening position with respect to the said drying chamber 10 of the said lignite discharge line 16. The height difference between the opening position of the lignite supply line 13 and the opening position of the lignite discharge line 16 is appropriately determined depending on the fluidity of the lignite 6 liquefied by bubbling and the drying processing capability of the drying device 12. .

  In the drying chamber 10, a plurality of dividing walls provided to divide the drying chamber 10 into a plurality of drying compartments, for example, a first dividing wall 37, a second dividing wall 38, and a third dividing wall 39. The three dividing walls are provided.

  An upper end of the first dividing wall 37 protrudes above the surface of the fluidized bed 22, and a gap 41 having a predetermined interval is formed between the lower end and the bottom plate 18 of the drying chamber 10. The second dividing wall 38 is provided so as to protrude upward from the bottom plate 18 of the drying chamber 10, and the upper end is located below the surface of the fluidized bed 22 by a predetermined distance. Further, the upper end of the third dividing wall 39 projects upward from the surface of the fluidized bed 22, and a gap 42 having a predetermined interval is formed between the lower end and the bottom plate 18 of the drying chamber 10. The gap 41 and the gap 42 are appropriately selected according to the fluidity of the fluidized bed 22.

  A first drying compartment 43 is formed between the first dividing wall 37 and the side wall of the drying device 12 on the lignite supply line 13 side, and between the first dividing wall 37 and the second dividing wall 38. A second drying compartment 44 is formed, a third drying compartment 45 is formed between the second dividing wall 38 and the third dividing wall 39, and the lignite discharge of the third dividing wall 39 and the drying device 12 is performed. A fourth drying compartment 46 is formed between the side wall on the line 16 side.

  The lignite 6 supplied from the lignite supply line 13 is liquefied and meanders up and down in the first dry compartment 43 to the fourth dry compartment 46 until it is discharged from the lignite discharge line 16. Fluid and dry. In addition, by meandering the first drying compartment 43 to the fourth drying compartment 46, the flow path length becomes longer, the contact time between the lignite 6 and the heat transfer tube 31 becomes longer, and drying is promoted.

  Next, the drying of the lignite 6 by the hydrated matter drying system 5 according to the present embodiment will be further described.

  First, the unpulverized lignite 6 is put into the pulverizer 11 and pulverized by the pulverizer 11 so that the particle diameter becomes 2 mm or less. After the lignite 6 crushed by the pulverizer 11 is stored by the lignite hopper 36, the lignite 6 is charged into the drying device 12 through the lignite supply line 13.

  The lignite 6 supplied to the drying device 12 is deposited in the first drying compartment 43 and liquefied by supplying the bubbling steam 19 to the deposited lignite 6 via the fluid medium supply pipe 21. Thus, the fluidized bed 22 of the lignite 6 having fluidity is formed. When starting up the hydrated matter drying system 5, steam is extracted from the turbine of another boiler (not shown) through the startup steam introduction line 33. Is opened, a part of the steam flowing through the starting steam introduction line 33 is supplied to the fluid medium supply pipe 21 as the bubbling steam 19 through the bubbling steam side starting steam introduction line 33a.

  In parallel with the above processing, by opening the valve 35, the remainder of the steam flowing through the startup steam introduction line 33 is transferred to the superheated steam introduction line 27 via the superheated steam side startup steam introduction line 33b. The superheated steam is introduced into the superheated steam and is heated and raised by the compressor 28, and the superheated steam flows through the heat transfer pipe 31.

  The fluidized bed 22 flows downward in the first drying compartment 43, passes through the gap 41, and flows into the second drying compartment 44. At this time, since the introduced lignite 6 contains a large amount of water, the lignite 6 flows down by its own weight, flows down without staying in the first drying compartment 43, and the lower lignite 6 It is extruded into the second drying compartment 44 through the gap 41 by pressure from above. The lignite 6 is in contact with the heat transfer pipe 31 in the process of flowing from the first drying compartment 43 to the second drying compartment 44 and is heated by heat exchange with superheated steam flowing through the heat transfer pipe 31 to be dried. Is done.

  Further, since the gap 41 is set according to the fluidity of the fluidized bed 22, the lignite 6 does not move over the first dividing wall 37 and move to the second drying compartment 44. It has become. Further, the supply amount of the lignite 6 from the lignite hopper 36 is adjusted so as not to move over the first dividing wall 37 and move to the second drying compartment 44.

  The lignite 6 that has flowed into the second drying compartment 44 is reversed in the second drying compartment 44 and flows upward from below, and passes over the second dividing wall 38 to the third drying compartment 45. And flow. At this time, the lignite 6 is dried by heat exchange in the first drying compartment 43 and the fluidity of the fluidized bed 22 is increased, and the lignite 6 flows backward by the pressure from the first drying compartment 43 side. It smoothly flows to the third drying compartment 45 without doing so. Also, in the second drying compartment 44, the lignite 6 is heated and dried by the superheated steam flowing through the heat transfer pipe 31 in the process of flowing into the third drying compartment 45.

  The lignite 6 that has flowed into the third drying compartment 45 is further heated by the superheated steam that circulates in the heat transfer pipe 31, and flows in the reverse direction in the third drying compartment 45 while being dried, It flows through the gap 42 and flows into the fourth drying compartment 46.

  The lignite 6 that has flowed into the fourth drying compartment 46 is finally heated by the superheated steam flowing through the heat transfer pipe 31 and flows in an upward direction in the fourth drying compartment 46 while being dried. Then, it is discharged from the lignite discharge line 16 as the dry lignite 7 in powder form.

  The lignite 6 flows while inverting the first drying compartment 43 to the fourth drying compartment 46, and the steam 23 generated in the process of drying is outside the drying chamber 10 through the exhaust line 14. And is sent to the dust collector 15.

  The dust collector 15 separates and collects the powder of the lignite 6 from the steam 23, feeds the powder of the lignite 6 to the lignite discharge line 16 through the powder discharge line 24, and The steam 23 from which the brown coal 6 powder has been removed is introduced into the steam circulation line 25.

  A part of the steam 23 flowing through the steam circulation line 25 is sent to the fluid medium supply pipe 21 as the bubbling steam 19 by the blower 26. When the steam 23 is supplied to the fluid medium supply pipe 21 as the bubbling steam 19, the valve 34 is closed and the supply of the steam introduced from the starting steam introduction line 33 is stopped. The

  The remainder of the steam 23 flowing through the steam circulation line 25 is sucked into the superheated steam introduction line 27 and boosted by the compressor 28 driven by the drive steam from the drive steam introduction line 29. It is heated and introduced into the heat transfer tube 31 as superheated steam. When the steam 23 is introduced into the heat transfer pipe 31 as superheated steam by the compressor 28, the valve 35 is closed and the supply of steam introduced from the starting steam introduction line 33 is stopped. Is done.

  The superheated steam undergoes heat exchange with the lignite 6 in the fluidized bed 22 in the process of flowing through the heat transfer pipe 31, and the condensed latent heat is recovered to change the phase to become condensed water. To a condenser such as a condenser (not shown).

  The dried lignite 7 discharged from the drying chamber 10 and the powder of the lignite 6 separated and collected by the dust collector 15 are recovered by the heat exchanger 17 and cooled. The dried lignite 7 is burned by the burner 3.

  The combustion exhaust gas 8 generated by the dry lignite 7 is exhausted through the flue 9 and drives a gas turbine (not shown). A part of the steam generated when heat is recovered from the combustion exhaust gas 8 is introduced into the compressor 28 via the drive steam introduction line 29 to drive the compressor 28.

  As described above, in the present embodiment, when the lignite 6 that is a hydrous material is burned, the lignite 6 pulverized by the pulverizer 11 is dried by the drying device 12, and the dried lignite 7 is used as the dry lignite 7. Since the fuel is supplied to the burner 3 and combusted, it is possible to prevent a large amount of moisture from being brought into the furnace 2, and the temperature in the furnace 2 is reduced by water vapor evaporated in the furnace 2. Can be suppressed and boiler efficiency can be improved.

  Further, in this embodiment, the steam 23 generated when the lignite 6 is dried is heated up by the compressor 28 to be superheated steam, and the superheated steam is used as a heat source for drying the lignite 6. Therefore, the heat generated during the drying process can be used effectively, and the drying efficiency of the lignite 6 can be improved.

  Further, in this embodiment, the compressor 28 which is a boosting means for converting the steam into superheated steam is driven by steam, and the compressor 28 is driven by a part of the steam generated when heat is recovered from the combustion exhaust gas 8. As a result, an electric system or the like for driving the compressor 28 becomes unnecessary, and the system can be simplified.

  In the present embodiment, the steam-driven compressor 28 is used as a boosting means. For example, an ejector that sucks the steam 23 using the driving steam from the driving steam introduction line 29 as a driving medium is used. You may use as a pressure | voltage rise means. By using an ejector that does not have a mechanical drive unit as a booster, the failure rate is significantly reduced, costs can be reduced, maintenance work for the booster is not required, and the reliability of the hydrated matter drying system 5 is improved. Can be made.

  Further, an electric drive compressor may be used as the boosting means.

  In this embodiment, the case where the lignite 6 is dried by the hydrated material drying system 5 is described, but also when other hydrated material such as biomass is used as the fuel of the boiler device 1, Needless to say, the hydrated material drying system 5 of this embodiment is applicable.

DESCRIPTION OF SYMBOLS 1 Boiler apparatus 2 Furnace 3 Burner 5 Water content drying system 6 Brown coal (water content)
7 Dry brown coal 8 Combustion exhaust gas 10 Drying chamber 12 Drying device 13 Brown coal supply line 14 Exhaust line 15 Dust collector 16 Brown coal discharge line 19 Bubbling steam (fluid medium)
21 Fluidizing medium supply pipe 22 Fluidized bed 23 Steam 25 Steam circulation line 26 Blower 27 Superheated steam introduction line 28 Compressor (pressure increase means)
29 Drive steam introduction line 31 Heat transfer tube (heating means)
32 Drain pipe 33 Start-up steam introduction line 37 First dividing wall 38 Second dividing wall 39 Third dividing wall 43 First drying compartment 44 Second drying compartment 45 Third drying compartment 46 Fourth drying compartment

Claims (3)

A boiler device comprising a hydrated material drying system for drying hydrated material, and a burner provided on a furnace wall of the furnace and using the hydrated material dried as fuel, the hydrated material drying system drying the hydrated material A drying apparatus for separating, collecting and removing the powder of the hydrated product in the steam generated from the hydrated product by drying, and heating the steam from which the powder of the hydrated product has been removed by pressurizing and heating. Pressurizing means for generating steam; fluid medium supplying means for extracting a part of the steam and supplying it as a fluid medium to the drying device to liquefy the hydrated material; and circulating the superheated steam to heat the hydrated material. A heat transfer tube to be dried by replacement, a startup steam introduction line for extracting a part of the steam from the turbine of another boiler in operation and introducing it into the heat transfer tube and the fluidized medium supply means, and at the time of startup of the hydrated matter drying system Previous Boiler apparatus characterized by comprising a valve to open a starting vapor introduction line.   2. The boiler apparatus according to claim 1, wherein the boosting means extracts a part of the steam generated in the boiler apparatus and uses the extracted steam as a drive source. The drying device includes: a drying chamber in which the hydrated material is stored; a hydrated material supply unit that supplies the hydrated material from one end of the drying chamber; and the hydrated material dried from the other end of the drying chamber. Discharging means for discharging, the heat transfer pipe provided in the drying chamber, exhaust means for exhausting steam generated from the water-containing material by heating, and dividing the drying chamber into a plurality of drying compartments, A plurality of dividing walls provided so as to be alternately communicated with a lower portion and an upper portion; and the fluid medium supply means for ejecting a fluid medium from a bottom plate of the drying chamber, and the water content liquefied by the fluid medium The boiler apparatus of Claim 1 or Claim 2 comprised so that a thing might flow between each drying compartment, reversing at the lower end or upper end of the said division wall.

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