JP5693493B2 - Gasification combined cycle power generation system using fluidized bed dryer and coal - Google Patents

Description

  The present invention relates to a fluidized bed drying apparatus for drying a material to be dried by fluidizing steam or fluidizing gas, and a gasification combined power generation system using coal.

  For example, a combined coal gasification power generation facility is a power generation facility that aims to further increase the efficiency and environmental performance compared to conventional coal-fired power generation by gasifying coal and combining it with combined cycle power generation. This coal gasification combined cycle power generation facility has a great merit that it can use coal with abundant resources, and it is known that the merit can be further increased by expanding the applicable coal types.

  Conventional coal gasification combined power generation facilities generally have a coal supply device, a drying device, a coal gasification furnace, a gas purification device, a gas turbine facility, a steam turbine facility, an exhaust heat recovery boiler, a gas purification device, and the like. ing. Therefore, the coal is dried and then pulverized, supplied to the coal gasifier as pulverized coal, and air is taken in. The coal gas is combusted and gasified in this coal gasifier, and the product gas (combustible) Gas) is produced. Then, the product gas is purified and then supplied to the gas turbine equipment to burn and generate high-temperature and high-pressure combustion gas to drive the turbine. The exhaust gas after driving the turbine recovers thermal energy by the exhaust heat recovery boiler, generates steam and supplies it to the steam turbine equipment, and drives the turbine. As a result, power generation is performed. On the other hand, the exhaust gas from which the thermal energy has been recovered is released into the atmosphere through a chimney after harmful substances are removed by the gas purification device.

  By the way, the coal used in such a coal gasification combined power generation facility is not only a high-grade coal (high-grade coal) having a high calorific value such as bituminous coal and anthracite, but also a comparison such as sub-bituminous coal and lignite. There is a low-grade coal (low-grade coal) with a low calorific value. This low-grade coal has a large amount of moisture to be brought in, and the power generation efficiency decreases due to this moisture. For this reason, in the case of low-grade coal, it is necessary to dry the coal with the above-described drying apparatus to remove moisture and then pulverize and supply the coal gasifier.

  As a drying apparatus for drying such coal, there are those described in Patent Documents 1 and 2 below. The fluidized drying method and fluidized bed drying apparatus described in Patent Document 1 supplies wet fuel containing moisture from a fuel supply port to a supply chamber, and is covered by fluidized gas through a dispersion plate in the supply chamber and the drying classification chamber. When the fluid is flowed and dried and classified into fine powder and coarse particles, the layer thickness of the fluidized bed in the supply chamber is controlled separately from the layer thickness of the fluidized bed in the dry classification chamber.

  In addition, the fluidized dryer and the drying method described in Patent Document 2 are configured so that the flow rate of the heat source / fluidizing gas blown from the lower side of the gas dispersion plate just below the charging chute is below the gas dispersion plate other than the lower portion of the charging chute. It is made faster than the flow rate of the heat source and fluidizing gas blown from the side.

JP 2008-128524 A JP 2011-69609 A

  As described above, the low-grade coal has a higher moisture content than the high-grade coal, so that fluidization failure occurs in the drying device, which may cause drying failure. In particular, in the region close to the inlet portion, the water concentration is high and the dispersibility of the particles is not good. This may cause fluidization failure, adhesion, and accumulation near the heat transfer tube and at the bottom surface, resulting in blockage. . Therefore, it is necessary to reduce the amount of coal to be input, and there is a problem that the processing amount decreases.

  In the proposal described in Patent Document 1 described above, the raw material particles (raw coal) having a high water content are controlled by controlling the layer thickness of the fluidized bed in the supply chamber separately from the layer thickness of the fluidized bed in the dry classification chamber. Is stably dried and classified while suppressing the occurrence of agglomeration and adhesion to the apparatus. However, this technique has a problem that the moisture evaporation load per unit volume of the fluidized bed in the supply chamber is increased, and the amount of heat for properly drying the raw material is insufficient.

Further, in the proposal described in Patent Document 2, the flow rate of the heat source / fluidizing gas is set to be higher than the flow rate of the heat source / fluidizing gas blown from the lower side of the gas dispersion plate other than just below the charging chute. However, for example, low-grade coal such as lignite has a moisture content of 60% or more, which is higher than the moisture content of coal, which is high-grade coal (9-13%), so it is not sufficient to make the fluidizing gas faster. Therefore, further measures to cope with the drying of low-grade coal are eagerly desired.
Further, when water vapor is used for drying low-grade coal, the water vapor is condensed on the raw material particles immediately after the addition, forming aggregated particles, which may cause flow failure.
Furthermore, in some large-capacity drying devices, heat transfer tubes are provided to promote drying. However, when raw materials with extremely high water content are supplied, they adhere to the periphery of the heat transfer tubes and become blocked. There is a risk of letting it.

  This invention solves the subject mentioned above, and it aims at providing the gasification combined cycle power generation system using the fluidized-bed drying apparatus and coal which can improve a drying efficiency.

The first invention of the present invention for solving the above-described problems includes a dry container having a hollow shape, a wet fuel input part for supplying wet fuel to one end side of the dry container, and the other end side of the dry container A dry matter discharge unit that discharges dry matter obtained by heating and drying the wet fuel, and fluidized steam or fluidization that forms a fluidized bed together with the wet fuel by supplying fluidized steam or fluidized gas to the lower part of the drying container. A gas supply unit, and a gas discharge unit for discharging fluidized steam or fluidized gas and generated steam from above the drying container, and the drying container is divided into at least three parts in the moving direction of the wet fuel in the fluidized bed And forming at least three or more drying chambers with an inlet drying chamber, an intermediate drying chamber, and an outlet drying chamber, each of the drying chambers having a heat transfer tube, and the heat transfer tubes in the inlet drying chamber Heat transfer tubes in other drying rooms The flow rate of fluidized steam or fluidized gas into the inlet drying chamber is increased, and the heat transfer tubes in the outlet drying chamber are arranged more densely than the heat transfer tubes in other drying chambers. And increasing the flow rate of fluidized steam or fluidized gas into the outlet drying chamber, and the heating temperatures of the heat transfer tubes in the inlet drying chamber and the outlet drying chamber are set in the other drying chambers. It exists in the fluidized-bed drying apparatus characterized by making it higher than a heat exchanger tube .

A second invention is characterized in that, in the first invention, the temperature of the fluidized vapor or fluidized gas in the inlet drying chamber and the outlet drying chamber is higher than the temperatures in the other drying chambers. Located in fluidized bed dryer.

A third invention is the fluidized bed drying apparatus according to the first or second invention, wherein the fluidized bed cross-sectional area of the outlet drying chamber is increased toward the upper side.

According to a fourth aspect of the present invention, there is provided a fluidized bed drying apparatus according to any one of the first to third aspects, a coal gasification furnace that processes dry coal supplied from the fluidized bed drying apparatus and converts the dried coal into a gasified gas, and the gas connecting a gas turbine, a steam turbines operated by the steam generated by the exhaust heat recovery boiler for introducing turbine exhaust gas from said gas turbine, said gas turbine and / or the steam turbine to be operated gases as fuel lying in gasification combined cycle system using coal, characterized in that and a has been generator.

According to the present invention, the drying container is divided into at least three parts in the moving direction of the wet fuel in the fluidized bed, and an inlet drying chamber, an intermediate drying chamber, an outlet drying chamber, and at least three drying chambers are formed. Each of the chambers is provided with a heat transfer tube, and the heat transfer tube in the inlet drying chamber is arranged more coarsely than the heat transfer tubes in the other drying chambers, and fluidized steam or fluidized gas into the inlet drying chamber. And the heat transfer tubes in the outlet drying chamber are arranged more densely than the heat transfer tubes in the other drying chambers, and the flow rate of fluidized steam or fluidized gas into the outlet drying chamber is increased. Since the wet fuel is preliminarily dried, the wet fuel is reliably dried, and the wet fuel is transferred to the drying chamber on the downstream side while performing the final drying while suppressing poor fluidization, adhesion to the surroundings, and accumulation. The drying efficiency of can be improved.
As a result, it is possible to avoid adhesion, blockage, and flow failure during drying on the inlet side of the wet fuel, and it is possible to make the drying apparatus more compact and stable operation by improving the drying efficiency per unit volume.

FIG. 1 is a schematic side view showing a fluidized bed drying apparatus according to Embodiment 1 of the present invention. 2 is a schematic cross-sectional view taken along line AA of FIG. 1 showing the fluidized bed drying apparatus of Example 1. FIG. 3 is a schematic cross-sectional view taken along the line BB of FIG. 1 showing the fluidized bed drying apparatus of Example 1. FIG. 4 is a schematic cross-sectional view taken along the line CC of FIG. 1 showing the fluidized bed drying apparatus according to the first embodiment. FIG. 5-1 is a velocity performance diagram that defines the velocity of the fluidized gas. FIG. 5-2 is a drying rate performance diagram defined for the tube group arrangement. FIG. 5-3 is a drying rate performance diagram defined for the steam temperature of the in-layer heating pipe. FIG. 5-4 is a drying rate performance diagram defined for the fluidizing gas temperature. FIG. 6A is a performance diagram of fluidity and scattering properties defined for the velocity of fluidized gas. FIG. 6-2 is a performance diagram of fluidity and scattering properties defined for the tube group arrangement. FIG. 6-3 is a performance diagram of fluidity and scattering properties defined for the steam temperature of the in-layer heating pipe. FIG. 6-4 is a performance diagram of fluidity and scattering properties defined for the fluidizing gas temperature. FIG. 7 is a schematic side view showing a fluidized bed drying apparatus according to Embodiment 2 of the present invention. FIG. 8 is a performance diagram of fluidity and scattering properties defined for the velocity of fluidized gas. FIG. 9 is a schematic configuration diagram of a coal gasification combined power generation facility to which the fluidized bed drying apparatus of the embodiment is applied.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic side view showing a fluidized bed drying apparatus according to Embodiment 1 of the present invention, and FIG. 5 is a schematic configuration diagram of a coal gasification combined power generation facility to which the fluidized bed drying apparatus of Embodiment 1 is applied. .

  The coal gasification combined power generation facility (IGCC: Integrated Coal Gasification Combined Cycle) of Example 1 adopts an air combustion method in which coal gas is generated in a gasification furnace using air as an oxidizer, and is purified by a gas purifier. Coal gas is supplied as fuel gas to gas turbine equipment to generate electricity. That is, the combined coal gasification combined power generation facility of this embodiment is a power generation facility of an air combustion system (air blowing). In this case, low-grade coal is used as the wet fuel supplied to the gasifier.

  In Example 1, as shown in FIG. 5, the coal gasification combined power generation facility 10 includes a coal supply device 11, a fluidized bed drying device 12, a pulverized coal machine (mill) 13, a coal gasification furnace 14, and a char recovery device 15. , A gas refining device 16, a gas turbine facility 17, a steam turbine facility 18, a generator 19, and a heat recovery steam generator (HRSG) 20.

  The coal feeder 11 includes a raw coal bunker 21, a coal feeder 22, and a crusher 23. The raw coal bunker 21 can store low-grade coal, and can drop a predetermined amount of low-grade coal into the coal feeder 22. The coal feeder 22 can transport the low-grade coal dropped from the raw coal bunker 21 by a conveyor or the like and drop it on the crusher 23. The crusher 23 can crush the dropped low-grade coal into a predetermined size.

  The fluidized bed drying device 12 supplies drying steam (superheated steam) to the low-grade coal introduced by the coal feeder 11 so as to heat and dry the low-grade coal while flowing. Moisture contained in the graded coal can be removed. The fluidized bed drying device 12 is provided with a cooler 31 for cooling the dried low-grade coal taken out from the lower portion, and the dried and cooled dried coal is stored in the dried coal bunker 32. Further, the fluidized bed drying apparatus 12 is provided with a dry coal cyclone 33 and a dry coal electrostatic precipitator 34 for separating dry coal particles from steam taken out from above, and the dry coal particles separated from the steam are dried coal bunker. 32 is stored. The steam from which the dry coal has been separated by the dry coal electrostatic precipitator 34 is compressed by the steam compressor 35 and then supplied to the fluidized bed drying device 12 as drying steam.

  The pulverized coal machine 13 is a pulverizer, and pulverizes the low-grade coal (dried coal) dried by the fluidized bed dryer 12 into fine particles to produce pulverized coal. That is, in the pulverized coal machine 13, the dry coal stored in the dry coal bunker 32 is dropped by the coal feeder 36, and the dry coal is converted into low-grade coal having a predetermined particle size or less, that is, pulverized coal. The pulverized coal after being pulverized by the pulverized coal machine 13 is separated from the conveying gas by the pulverized coal bag filters 37a and 37b and stored in the pulverized coal supply hoppers 38a and 38b.

  The coal gasification furnace 14 can supply pulverized coal processed by the pulverized coal machine 13 and can be recycled by returning the char (unburned coal) recovered by the char recovery device 15. .

  That is, the coal gasification furnace 14 is connected to the compressed air supply line 41 from the gas turbine equipment 17 (compressor 61), and can supply compressed air compressed by the gas turbine equipment 17. The air separation device 42 separates and generates nitrogen and oxygen from air in the atmosphere. A first nitrogen supply line 43 is connected to the coal gasifier 14, and a pulverized coal supply hopper is connected to the first nitrogen supply line 43. Charging lines 44a and 44b from 38a and 38b are connected. The second nitrogen supply line 45 is also connected to the coal gasification furnace 14, and the char return line 46 from the char recovery device 15 is connected to the second nitrogen supply line 45. Further, the oxygen supply line 47 is connected to the compressed air supply line 41. In this case, nitrogen is used as a carrier gas for coal and char, and oxygen is used as an oxidant.

  The coal gasification furnace 14 is, for example, a spouted bed type gasification furnace, which combusts and gasifies coal, char, air (oxygen) supplied therein or water vapor as a gasifying agent, and produces carbon dioxide. A combustible gas (product gas, coal gas) containing carbon as a main component is generated, and a gasification reaction takes place using this combustible gas as a gasifying agent. The coal gasification furnace 14 is provided with a foreign matter removing device 48 that removes foreign matter mixed with pulverized coal. In this case, the coal gasification furnace 14 is not limited to the spouted bed gasification furnace, and may be a fluidized bed gasification furnace or a fixed bed gasification furnace. The coal gasification furnace 14 is provided with a gas generation line 49 for combustible gas toward the char recovery device 15, and can discharge combustible gas containing char. In this case, by providing a gas cooler in the gas generation line 49, the combustible gas may be cooled to a predetermined temperature and then supplied to the char recovery device 15.

  The char recovery device 15 includes a dust collector 51 and a supply hopper 52. In this case, the dust collector 51 is constituted by one or a plurality of bag filters or cyclones, and can separate char contained in the combustible gas generated in the coal gasification furnace 14. The combustible gas from which the char has been separated is sent to the gas purification device 16 through the gas discharge line 53. The supply hopper 52 stores the char separated from the combustible gas by the dust collector 51. A bin may be disposed between the dust collector 51 and the supply hopper 52, and a plurality of supply hoppers 52 may be connected to the bin. A char return line 46 from the supply hopper 52 is connected to the second nitrogen supply line 45.

The gas purification device 16 performs gas purification by removing impurities such as sulfur compounds and nitrogen compounds from the combustible gas from which the char has been separated by the char recovery device 15. The gas purifier 16 purifies the combustible gas to produce fuel gas and supplies it to the gas turbine equipment 17. In the gas purifier 16, since the combustible gas from which the char is separated still contains sulfur (H ₂ S), the sulfur is finally removed by removing it with the amine absorbent. Is recovered as gypsum and used effectively.

  The gas turbine equipment 17 includes a compressor 61, a combustor 62, and a turbine 63, and the compressor 61 and the turbine 63 are connected by a rotating shaft 64. The combustor 62 has a compressed air supply line 65 connected to the compressor 61, a fuel gas supply line 66 connected to the gas purifier 16, and a combustion gas supply line 67 connected to the turbine 63. Further, the gas turbine equipment 17 is provided with a compressed air supply line 41 extending from the compressor 61 to the coal gasification furnace 14, and a booster 68 is provided in the middle. Therefore, in the combustor 62, the compressed air supplied from the compressor 61 and the fuel gas supplied from the gas purifier 16 are mixed and burned, and the rotating shaft 64 is rotated by the generated combustion gas in the turbine 63. By doing so, the generator 19 can be driven.

  The steam turbine facility 18 includes a turbine 69 that is coupled to the rotating shaft 64 in the gas turbine facility 17, and the generator 19 is coupled to the base end portion of the rotating shaft 64. The exhaust heat recovery boiler 20 is provided in the exhaust gas line 70 from the gas turbine equipment 17 (the turbine 63), and generates steam by exchanging heat between the air and the high temperature exhaust gas. Therefore, the exhaust heat recovery boiler 20 is provided with the steam supply line 71 between the steam turbine equipment 18 and the turbine 69 of the steam turbine equipment 18, the steam recovery line 72 is provided, and the steam recovery line 72 is provided with the condenser 73. Yes. Therefore, in the steam turbine facility 18, the turbine 69 is driven by the steam supplied from the exhaust heat recovery boiler 20, and the generator 19 can be driven by rotating the rotating shaft 64.

  The exhaust gas from which heat has been recovered by the exhaust heat recovery boiler 20 is freed of harmful substances by the gas purification device 74, and the purified exhaust gas is discharged from the chimney 75 to the atmosphere.

  Here, the action | operation of the coal gasification combined cycle power generation equipment 10 of Example 1 is demonstrated.

  In the coal gasification combined power generation facility 10 of the first embodiment, raw coal (low-grade coal) is stored in the raw coal bunker 21 by the coal feeder 11, and the low-grade coal of the raw coal bunker 21 is supplied to the coal. The machine 22 drops the crusher 23 where it is crushed to a predetermined size. The crushed low-grade coal is heated and dried by the fluidized bed drying device 12, cooled by the cooler 31, and stored in the dry coal bunker 32. Further, the steam taken out from the upper part of the fluidized bed drying device 12 is separated into dry coal particles by the dry coal cyclone 33 and the dry coal electrostatic precipitator 34 and compressed by the steam compressor 35 before being supplied to the fluidized bed drying device 12. Returned as drying steam. On the other hand, the dry coal particles separated from the steam are stored in the dry coal bunker 32.

  The dry coal stored in the dry coal bunker 32 is fed into the pulverized coal machine 13 by the coal feeder 36, where it is pulverized into fine particles to produce pulverized coal, which passes through the pulverized coal bag filters 37a and 37b. And stored in the pulverized coal supply hoppers 38a and 38b. The pulverized coal stored in the pulverized coal supply hoppers 38 a and 38 b is supplied to the coal gasification furnace 14 through the first nitrogen supply line 43 by nitrogen supplied from the air separation device 42. Further, the char recovered by the char recovery device 15 described later is supplied to the coal gasifier 14 through the second nitrogen supply line 45 by nitrogen supplied from the air separation device 42. Further, the compressed air extracted from the gas turbine equipment 17 to be described later is boosted by the booster 68 and then supplied to the coal gasification furnace 14 through the compressed air supply line 41 together with oxygen supplied from the air separation device 42.

  In the coal gasification furnace 14, the supplied pulverized coal and char are combusted by compressed air (oxygen), and the pulverized coal and char are gasified to generate combustible gas (coal gas) mainly composed of carbon dioxide. Can be generated. The combustible gas is discharged from the coal gasifier 14 through the gas generation line 49 and sent to the char recovery device 15.

  In the char recovery device 15, the combustible gas is first supplied to the dust collector 51, whereby the char contained in the gas is separated from the combustible gas. The combustible gas from which the char has been separated is sent to the gas purification device 16 through the gas discharge line 53. On the other hand, the fine char separated from the combustible gas is deposited on the supply hopper 52, returned to the coal gasifier 14 through the char return line 46, and recycled.

  The combustible gas from which the char has been separated by the char recovery device 15 is subjected to gas purification by removing impurities such as sulfur compounds and nitrogen compounds in the gas purification device 16 to produce fuel gas. In the gas turbine facility 17, when the compressor 61 generates compressed air and supplies the compressed air to the combustor 62, the combustor 62 is supplied from the compressed air supplied from the compressor 61 and the gas purification device 16. Combustion gas is generated by mixing with fuel gas and combusting, and the turbine 63 is driven by this combustion gas, so that the generator 19 can be driven via the rotating shaft 64 to generate power.

  The exhaust gas discharged from the turbine 63 in the gas turbine equipment 17 generates steam by exchanging heat with air in the exhaust heat recovery boiler 20, and supplies the generated steam to the steam turbine equipment 18. . In the steam turbine facility 18, the generator 69 can be driven through the rotating shaft 64 to generate electric power by driving the turbine 69 with the steam supplied from the exhaust heat recovery boiler 20.

  Thereafter, in the gas purification device 74, harmful substances in the exhaust gas discharged from the exhaust heat recovery boiler 20 are removed, and the purified exhaust gas is discharged from the chimney 75 to the atmosphere.

  Hereinafter, the fluidized bed drying apparatus 12 in the coal gasification combined power generation facility 10 described above will be described in detail.

  As shown in FIG. 1, the fluidized bed drying apparatus 12 includes a drying container 101, a raw coal charging port (wet fuel charging unit) 102, a dry coal discharging port (dry matter discharging unit) 103, fluidized steam or fluidized flow. A fluidizing gas supply unit (not shown) for supplying a gasified gas (hereinafter referred to as “fluidizing gas”) 104 (104a, 104b), a gas discharge port (gas discharge unit) 105, and a heat transfer tube (heating unit) 106a. , 106b.

  The drying container 101 has a hollow box shape, and is formed with a raw coal charging port 102 for charging raw coal (wet fuel) on one end side, and dried by heating and drying raw coal on a lower portion on the other end side. A dry charcoal discharge port 103 for discharging the material is formed, and the raw coal is dried by an extrusion method (plug flow) inside the drying container 101. In this case, the raw coal input port 102 and the dry coal discharge port 103 are provided one by one at the end of the drying container 101, but a plurality of them may be provided. In addition, the drying container 101 is provided with a dispersion plate 108 having a plurality of openings at a predetermined distance from the bottom plate 101a in the lower portion, so that an air box 109 is partitioned. And the drying container 101 is provided with the fluidization gas supply part which supplies the fluidization gas (superheated steam) 104 above the dispersion | distribution board 108 via the wind box 109 by this bottom plate 101a side. Further, in the drying container 101, a gas discharge port 105 for discharging the fluidized gas 104 and generated steam is formed in the ceiling plate 101b on the dry coal discharge port 103 side.

  The drying container 101 is supplied with raw coal from the raw coal inlet 102 and supplied with fluidizing gas 104 from the fluidizing gas supply section through the wind box 109 and the dispersion plate 108, thereby A fluidized bed S having a predetermined thickness is formed above, and a free board portion F is formed above the fluidized bed S.

  The drying container 101 of the present embodiment is internally partitioned by two partition plates 113a and 113b, and is provided with an inlet portion drying provided on the upstream side (wet fuel input portion 102 side) in the raw coal flow direction. The chamber 111a includes an intermediate drying chamber 111b provided on the downstream side in the flow direction of the raw coal, and an outlet 3 drying chamber 111c on the dry matter discharge unit 103 side.

  The partition plates 113a and 113b are installed from the upper surface of the dispersion plate 108, and an opening (flow port) 113a through which raw coal passes is formed in a part of the partition plate. The shape and size of the opening may be appropriately changed or changed depending on the wet state of the raw coal. Further, the upper end portion of the partition plate 113 is positioned so as to extend above the fluidized bed S so that the flowd raw coal does not flow over the partition plates 113a and 113b to the downstream side.

  The inlet drying chamber 111a, the intermediate drying chamber 111b, and the outlet drying chamber 111c communicate with each other above the partition plate 113. In this case, the inlet portion drying chamber 111a is a region where the freeboard portion F1 and the fluidized bed S1 are formed and performs initial drying (preliminary drying) of the raw coal, and the outlet portion drying chamber 111c is the freeboard portion F3. And the fluidized bed S3 is formed, and this is a region where late drying (finish drying) of raw coal is performed.

  In this case, the wind box 109 is partitioned into wind boxes 109a, 109b, and 109c corresponding to the inlet drying chamber 111a, the intermediate drying chamber 111b, and the outlet drying chamber 111c, and fluidized corresponding to the wind boxes 109a to 109c. A gas supply unit is provided. And the gas quantity of the fluidization gas 104a-104c supplied in the wind boxes 109a-109c can be adjusted by adjusting the opening degree of the flow regulating valve which is not illustrated.

  First, in this embodiment, fluidized beds are classified into an inlet drying chamber 111a, an intermediate drying chamber 111b, and an outlet drying chamber 111c in the raw material flow direction, and fluidized beds S1, S2, and S3 are formed, respectively.

  The inlet drying chamber 111a is a region where the raw coal is preheated or a constant rate drying period is partially mixed since the wet raw material is input from the raw coal inlet 102.

  The intermediate drying chamber 111b is a region where a constant rate drying period or a partial reduction rate drying period is mixed, or a part preheating period is mixed.

The outlet portion drying chamber 111c is a region where a decreasing rate drying period or a partial constant rate drying period is mixed.
Here, the partially mixed region means a room at the boundary of each part, and the room has a preheat drying period and a constant rate drying period mixed, or a constant rate drying period and a reduced rate drying period mixed.
Further, the preheating drying period refers to a period in which the raw material temperature is rising below the saturated vapor temperature.
The constant rate drying period refers to a period in which the evaporation rate has a constant value and the raw material temperature maintains a constant temperature (saturated steam temperature).
Further, the decreasing rate drying period refers to a period in which the evaporation rate starts to decrease and the raw material temperature rises from the saturated vapor temperature.

  In this embodiment, in the inlet drying chamber 111a, the intermediate drying chamber 111c, and the outlet drying chamber 111c, the intermediate drying chamber 111b is a standard specification, whereas the inlet drying chamber 111a and the outlet drying chamber 111c The specifications are as follows.

First, in the inlet drying chamber 111a, the tube group arrangement of the heat transfer tubes 106a is roughened and the fluidizing gas velocity is increased.
In the outlet drying chamber 111c, the tube group arrangement of the heat transfer tubes 106c is made dense and the fluidizing gas velocity is increased.
By setting it as such a structure, the compactness and flow stability of a drying apparatus are achieved simultaneously.

2 is a schematic cross-sectional view taken along line AA of FIG. 1 showing the fluidized bed drying apparatus of Example 1. FIG.
3 is a schematic cross-sectional view taken along the line BB of FIG. 1 showing the fluidized bed drying apparatus of Example 1. FIG.
4 is a schematic cross-sectional view taken along the line CC of FIG. 1 showing the fluidized bed drying apparatus according to the first embodiment.
As shown in FIG. 2, the heat transfer tube 106 a in the inlet drying chamber 111 a penetrates the side wall 101 c of the drying vessel 101 from the outside and is disposed in the fluidized bed S <b> 1 with a predetermined interval coarser than the standard. Then, superheated steam is supplied to the inside to heat the raw coal in the fluidized bed S1 to remove moisture and to dry.

  As shown in FIG. 3, the heat transfer tube 106b in the intermediate drying chamber 111b penetrates the side wall 101c of the drying container 101 from the outside and is disposed in the fluidized bed S2 with a standard predetermined interval. Superheated steam is supplied to the raw coal in the fluidized bed S2 to dry it.

  As shown in FIG. 4, the heat transfer tube 106 c in the outlet drying chamber 111 c penetrates the side wall 101 c of the drying container 101 from the outside and is disposed in the fluidized bed S3 with a predetermined interval finer than the standard. Then, superheated steam is supplied to the inside to heat the raw coal in the fluidized bed S3 and dry it.

  As described above, the inlet drying chamber 111a, the intermediate drying chamber 111b, and the outlet drying chamber 111c have different heat transfer tube intervals. This is because, since the moisture content is about 60% and the moisture state is very high, if the interval between the heat transfer tubes is made small, the raw coal is clogged between the heat transfer tubes, and the drying efficiency is lowered, which is not preferable.

Furthermore, the steam temperature in the heating tube supplied to the heat transfer tubes 106a and 106c in the inlet drying chamber 111a and the outlet drying chamber 111c may be increased, or the temperature of the fluidized gases 104a and 104c may be increased.
Thereby, drying performance can be increased (compact) without impairing fluidity.

  Further, in this embodiment, the temperature of the superheated steam introduced into the heat transfer tubes 106a, 106c of the inlet drying chamber 111a and the outlet drying chamber 111c is determined from the temperature of the superheated steam introduced into the heat transfer tubes 106b of the intermediate drying chamber 111b. Is also high. The temperature is adjusted by controlling the pressure of superheated steam.

  For example, the temperature is adjusted by increasing the pressure of superheated steam supplied to the heat transfer tubes 106a and 106c to, for example, about 180 ° C., and setting the superheated steam supplied to the heat transfer tube 106b to a design temperature of, for example, 150 ° C. ing. Here, as the superheated steam, steam obtained by collecting steam discharged from the gas discharge unit 105 of the drying vessel 101 and recompressing with a compressor (not shown) or the like to recover latent heat can be used.

  This is for the purpose of improving the moisture removal efficiency because the inlet drying chamber 111a is a wet fuel with a lot of moisture (for example, 60%).

  Further, the temperature of the superheated steam supplied to the heat transfer tube 106b installed in the intermediate drying chamber 111b may be lower than the temperature supplied to the heat transfer tube 106a installed in the inlet drying chamber 111a. Since the heat transfer tube 106b provided in the intermediate drying chamber 111b has a standard arrangement, the heat transfer area is larger than that of the heat transfer tube 106a in the inlet drying chamber 111a, and the original is moved to the intermediate drying chamber 111b. Since the drying of the charcoal is progressing, the charcoal is in a smoother state than that of the raw coal immediately after the charging, and even if the temperature of the superheated steam supplied into the heat transfer tube 106b is lowered, the drying can be performed satisfactorily. It is.

In other words, the inlet drying chamber 111a is an area for forming initial drying (preliminary drying) of the supplied raw coal in the chamber.
For this reason, the wet fuel can be dried in a high temperature state by roughly installing the heat transfer pipe 106a installed in the inlet drying chamber 111a and increasing the pressure of the superheated steam to be supplied. At this time, since the gap between the heat transfer tubes 106a is rough, clogging of wet fuel is prevented.

The pre-dried raw coal is pushed out from the gap between the openings of the partition plate 113a and introduced into the intermediate drying chamber 111b from the inlet drying chamber 111a, where constant rate drying is performed.
The heat transfer tubes 106b installed in the intermediate drying chamber 111b are standardly arranged to improve drying efficiency.
Here, the extruding flow is a flow for extruding the raw coal in a fluidized direction in the fluidized beds S1 and S2 formed in the drying container 101 so that the raw coal does not diffuse in the flowing direction.

The raw coal that has been dried at a constant rate is pushed out from the gap in the opening of the partition plate 113b and introduced into the outlet drying chamber 111c on the downstream side from the intermediate drying chamber 111b, where finish drying is performed.
The heat transfer tubes 106c installed in the outlet drying chamber 111c are arranged more densely than the heat transfer tubes 106b, further improving the drying efficiency.

  As a result, the raw coal forming the fluidized bed S1 of the inlet drying chamber 111a, the fluidized bed S2 of the intermediate drying chamber 111b, and the outlet drying chamber 111c is sequentially discharged from the inlet drying chamber 111a on the upstream side. By moving to (1), drying according to the wet state of the wet fuel is appropriately performed, a good extruded flow can be obtained, and the wet fuel is dried without being diffused in the flow direction.

  In this embodiment, raw coal having a water content of about 60% is dried to, for example, 50 to 40% in the inlet drying chamber 111a. And in the intermediate part drying chamber 111b or later, for example, raw coal having a moisture content of about 50 to 40% can be finish-dried until the moisture content becomes about 30 to 10%.

Further, in this embodiment, the flow rates of the fluidizing gases 104a and 104c supplied into the inlet drying chamber 111a and the outlet drying chamber 111c are increased, and the flow velocity of the fluidizing gas 104b supplied into the intermediate drying chamber 111b is increased. It is standard.
Thereby, the input raw coal in the inlet drying chamber 111a is loosened by the high-speed fluidized gas 104a.
Further, by increasing the flow rate of the fluidized gas 104c to the outlet drying chamber 111c, the drying speed is improved and the drying efficiency is improved.
Thus, it becomes possible to prevent adhesion to the heat transfer tube 106a by increasing the rising speed of the vapor of the fluidized gas 104a in the inlet drying chamber 111a.

  Here, the gas flow rates of the fluidized gases 104a and 104c to the inlet drying chamber 111a and the outlet drying chamber 111c are preferably increased to about 3 to 5 times the minimum fluidization speed for forming the fluidized bed. It is preferable that the flow rate of the fluidizing gas in the partial drying chamber 111b exceeds the minimum fluidizing speed.

In addition, the diameter of the heat transfer tube 106c may be reduced instead of densely arranging the outlet drying chambers 111c. Here, the meaning that the arrangement is not changed means that (pipe pitch = a constant multiple of the pipe diameter) is maintained.
In this case, even if the tube diameter is reduced, the heat transfer area does not change, but the heat transfer coefficient increases, leading to improved drying performance.

FIGS. 5-1 to 5-4 and FIGS. 6-1 to 6-4 show the drying performance, fluidity, and scattering properties in the case of changing each influencing factor as relative changes with reference to the pre-change.
5A to 5D examine the degree of influence on the drying performance.

FIG. 5-1 is a drying rate performance diagram that defines the velocity of fluidized gas.
As shown in FIG. 5A, the inlet drying chamber 111a has a large fluidizing gas velocity, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is large.
In this case, the drying speed of the inlet drying chamber 111a and the outlet drying chamber 111c is higher than the normal performance.

FIG. 5-2 is a drying rate performance diagram defined for the tube group arrangement.
As shown in FIG. 5-2, the arrangement of the inlet drying chambers 111a is rough, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is dense.
In this case, with respect to normal performance, the drying speed of the inlet drying chamber 111a is slow, whereas the drying speed of the outlet drying chamber 111c is faster.

FIG. 5-3 is a drying rate performance diagram defined for the steam temperature of the in-layer heating pipe.
As shown in FIG. 5-3, the vapor temperature of the in-layer heating pipe of the inlet drying chamber 111a is increased, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is higher.
In this case, the drying speed of the inlet drying chamber 111a and the outlet drying chamber 111c is higher than the normal performance.

FIG. 5-4 is a drying rate performance diagram defined for the fluidizing gas temperature.
As shown in FIG. 5-4, the fluidizing gas temperature in the inlet drying chamber 111a is increased, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is increased.
In this case, the drying speed of the inlet drying chamber 111a and the outlet drying chamber 111c is higher than the normal performance.

  6A to 6D examine the degree of influence on the fluidity / scattering property.

FIG. 6A is a performance diagram of fluidity and scattering properties defined for the velocity of fluidized gas.
As shown in FIG. 6A, the inlet drying chamber 111a has a large fluidizing gas velocity, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is large.
In this case, the flowability (scatterability) of the inlet drying chamber 111a and the outlet drying chamber 111c is increased with respect to the normal performance.

FIG. 6-2 is a performance diagram of fluidity and scattering properties defined for the tube group arrangement.
As shown in FIG. 6B, the arrangement of the inlet drying chambers 111a is rough, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is dense.
In this case, with respect to normal performance, the inlet drying chamber 111a has high fluidity, whereas the outlet drying chamber 111c has low fluidity.

FIG. 6-3 is a performance diagram of fluidity and scattering properties defined for the steam temperature of the in-layer heating pipe.
As shown in FIG. 6-3, the vapor temperature of the in-layer heating pipe of the inlet drying chamber 111a is increased, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is increased.
In this case, there is no change in both normal fluidity and scattering properties.
In addition, the secondary effect by raw material drying promotion is excluded.

FIG. 6-4 is a performance diagram of fluidity and scattering properties defined for the fluidizing gas temperature.
As shown in FIG. 6-4, the fluidizing gas temperature in the inlet drying chamber 111a is increased, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is increased.
Also in this case, there is no change in both normal fluidity and scattering property.
In addition, the secondary effect by raw material drying promotion is excluded.

From the above results, it was found that what has a large influence on the drying characteristics, fluidity / scattering properties as an absolute value is the arrangement (roughness / denseness) of the tube group and the fluidizing gas velocity.
Therefore, the drying performance can be significantly improved by taking these two parameters into consideration. Other influential factors may be applied as necessary.

Here, in the present embodiment, the floor area ratio of the inlet drying chamber 111a, the intermediate drying chamber 111b, and the outlet drying chamber 111c is equally divided by 1/3. May be appropriately changed.
The optimum ratio is set according to the amount of raw coal treated. For example, when the amount of raw coal is large, it is preferable to widen the drying region of the inlet drying chamber 111a. Is set.

  In the present embodiment, the inlet drying chamber 111a and the intermediate drying chamber 111b are divided through the partition plate 113, but the present invention is not limited to this, and the drying container without the partition plate 113 is provided. 101 may be divided. This is because the drying chamber 101 can be apparently divided without providing a partition plate when the drying chamber is long in the flow direction.

  Here, the whole operation | movement of the fluidized bed drying apparatus 12 of Example 1 is demonstrated.

  In the fluidized bed drying apparatus 12, as shown in FIGS. 1 to 4, raw coal is supplied from the raw coal inlet 102 to the drying container 101, and from the fluidizing gas supply unit through the dispersion plate 108, for example, The fluidized gas 104 (104a, 104b, 104c) of superheated steam is supplied to form a fluidized bed S (S1, S2, S3) having a predetermined thickness above the dispersion plate 108. The raw coal of the wet fuel gradually moves in a compacted state to the dry coal discharge port 103 side through the fluidized bed S (S1, S2, S3) by the fluidizing gas 104 (104a, 104b, 104c). It is heated and dried by receiving heat from 106a, 106b and 106c.

In this case, the raw coal is heated and dried by the heat from the heat transfer tubes 106a to 106c and the fluidized gases 104a to 104c while moving from the raw coal inlet 102 to the dry coal outlet 103. The raw coal immediately after being introduced from 102 has a high moisture concentration, and there is a possibility that proper drying becomes difficult.
However, in the present embodiment, the inside of the drying container 101 in the raw coal flow direction is the inlet portion drying chamber 111a on the wet fuel input portion 102 side, the intermediate portion drying chamber 111b, and the outlet portion drying chamber on the dry matter discharge portion 103 side. 111c, and the heat transfer tubes 106a, 106b, 106c provided in each of the drying chambers 111a to 111c are set to have the intermediate drying chamber 111b as a standard, the heat transfer tubes in the inlet drying chamber 111a. 106a is made coarser than the standard, and the heat transfer tube 106c in the outlet drying chamber 111c is made denser than the standard.
Therefore, the raw coal input into the inlet portion drying chamber 111a from the raw coal inlet 102 is first subjected to initial drying (preliminary drying) in the inlet portion drying chamber 111a without clogging between the heat transfer tubes 106a and the like.

  The raw coal that has been initially dried in the inlet drying chamber 111a is pushed away at the opening of the partition plate 113 and gradually flows into the intermediate drying chamber 111b and the outlet drying chamber 111c. In the intermediate drying chamber 111b, the raw coal flows in the fluidized bed S2 by the fluidized gas 104b, and is heated by the heat transfer tube 106b in the fluidized bed S2 and becomes an extruded flow without being diffused in the flow direction. Drying is done. Thereafter, it is moved to the outlet drying chamber 111c, in which the raw coal flows in the fluidized bed S3 by the fluidized gas 104c and is heated by the heat transfer tube 106c in the fluidized bed S3 while being pushed out. Thus, finish drying is performed without diffusing in the flow direction.

  Thereafter, the dry coal from which the raw coal has been dried is discharged to the outside through the dry coal discharge port 103, and the steam generated by heating and drying the raw coal in the fluidized beds S1, S2, and S3 rises together with the fluidized gas. Then, it flows to the dry coal discharge port 103 side and is discharged from the gas discharge port 105 to the outside.

  Thus, in the fluidized bed drying apparatus of Example 1, the drying container is divided into three chambers (the inlet drying chamber 111a, the intermediate drying chamber 111b, and the outlet drying chamber 111c), and each of them is wet. In a plug flow type fluidized bed dryer provided with heat transfer tubes 106a, 106b, 106c for heating fuel, the heat transfer tubes 106a in the inlet drying chamber 111a are arranged more coarsely than heat transfer tubes in other drying chambers. In addition, the flow rate of the fluidized gas 104a into the inlet drying chamber 111a is increased, and the heat transfer tubes 106c in the outlet drying chamber 111c are arranged more densely than the heat transfer tubes in the other drying chambers. At the same time, the flow rate of the fluidized gas 104c into the outlet drying chamber 111c is increased.

  Accordingly, the raw coal is introduced into the drying container 101 from the raw coal inlet 102, and the fluidizing gas 104 (104a, 104b, 104c) is supplied from the lower part of the drying container 101 through the dispersion plate 108 from the fluidizing gas supply unit. Then, the raw coal flows by the fluidized gas 104 (104a, 104b, 104c) to form a fluidized bed S (S1, S2, S3), and the raw coal in the fluidized bed S moves by the fluidized gas. When heated, the heat transfer tubes 106a, 106b, 106c are dried to become dry charcoal, and this dry charcoal is discharged to the outside from the dry charcoal discharge port 103, while the fluidized gas and raw coal are dried. The steam generated in the above is discharged from the gas discharge port 105 to the outside.

At this time, although the raw coal immediately after being input from the raw coal input port 102 has a large amount of water, the drying vessel 101 is divided in the moving direction of the wet fuel in the fluidized bed, so that at least three or more drying chambers 111a are provided. 111b, 111c, and three or more heat transfer tubes 106a, 106b, 106c for heating the wet fuel in the fluidized bed in each of the drying chambers 111a, 111b, 111c. The heat transfer tube 106a is roughly disposed and the heating temperature of the heat transfer tube 106a is increased, so that the raw coal is pre-dried reliably, while suppressing fluidization failure, adhesion to the surroundings and accumulation, It is pushed into the intermediate drying chamber 111b, where it is dried at a constant rate, and then pushed into the outlet drying chamber 111c, where it is subjected to finish drying, thereby improving the drying efficiency of the raw coal. It is possible.
As a result, it is possible to avoid adhesion, clogging, and poor flow in the drying in the inlet drying chamber 111a on the inlet side of the wet fuel, and the drying efficiency per unit volume can be improved and the drying apparatus can be made compact and stable. It becomes possible.
Therefore, it is possible to ensure the fluidity and drying performance of the inlet and the outlet while reducing the size of the drying apparatus 101.

  FIG. 7 is a schematic side view showing a fluidized bed drying apparatus according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

In the fluidized bed drying apparatus of Example 2, as shown in FIG. 7, the drying container 101 is divided into three parts using two partition plates 113a and 113b, and an inlet drying chamber 111a, an intermediate drying chamber 111b, and an outlet. The drying chamber 111c is used. In each drying chamber, heat transfer tubes 106a, 106b, and 106c are provided.
Also in the second embodiment, the heat transfer tube 106b installed in the intermediate drying chamber 111b is a standard gap, and the heat transfer tube 106a installed in the inlet drying chamber 111a on the wet fuel charging unit 102 side is more than the heat transfer tube 106b. The heat transfer tube 106c installed in the outlet drying chamber 111c on the dry matter discharge unit 103 side is a tighter gap than the heat transfer tube 106b.

Further, the fluidized bed cross-sectional area of the outlet drying chamber 111c is increased toward the upper side.
Thereby, since it is made wider as it goes to the upper side, the superficial velocity of the fluidized gas becomes slow, and the amount of fine particles dried in the outlet drying chamber 111c is scattered from the gas outlet 105 to the outside is reduced. To do.

FIG. 8 is a performance diagram of fluidity and scattering properties defined for the velocity of fluidized gas.
As shown in FIG. 8, the inlet drying chamber 111a has a large fluidizing gas velocity, the intermediate drying chamber 111b is standard, and the outlet drying chamber 111c is large.
In this case, the flowability (scattering property) of the inlet drying chamber 111a is larger than that of the normal performance, but the scattering property is decreased in the outlet drying chamber 111c, and FIG. As compared with the case, it is possible to reduce the amount of fine particles scattered.

Here, in this embodiment, the floor area ratio of the inlet drying chamber 111a, the intermediate drying chamber 111b, and the outlet drying chamber 111c is 1/3 at a time. However, the present invention is not limited to this, and these ratios are not limited thereto. May be appropriately changed.
This is an optimal ratio is set according to the raw coal processing amount, for example, when the raw coal processing amount is large, it is preferable to widen the drying region of the inlet intermediate drying chamber 111a, Set as appropriate.

DESCRIPTION OF SYMBOLS 11 Coal feeder 12 Fluidized bed dryer 13 Pulverized coal machine 14 Coal gasifier 15 Char recovery device 16 Gas refiner 17 Gas turbine equipment 18 Steam turbine equipment 19 Generator 20 Waste heat recovery boiler 101 Drying vessel 102 Raw coal input (Wet fuel input part)
103 Dry coal discharge port (dry matter discharge part)
104 (104a, 104b, 104c) Fluidized gas 105 Gas outlet (gas outlet)
106a, 106b, 106c Heat transfer tube (heating unit)
111a Inlet portion drying chamber 111b Intermediate portion drying chamber 111c Outlet portion drying chamber 113 Partition plate F (F1, F2, F3) Free board portion S (S1, S2, S3) Fluidized bed

Claims (4)

A drying container having a hollow shape;
A wet fuel charging unit for charging wet fuel to one end of the drying container;
A dry matter discharge unit for discharging dry matter obtained by heating and drying wet fuel from the other end of the drying container;
A fluidized steam or fluidized gas supply unit that forms a fluidized bed with wet fuel by supplying fluidized steam or fluidized gas to a lower portion of the drying container;
A gas discharge part for discharging fluidized steam or fluidized gas and generated steam from above the drying vessel, and
The drying container is divided into at least three parts in the moving direction of the wet fuel in the fluidized bed, and an inlet drying chamber, an intermediate drying chamber and an outlet drying chamber are formed, and at least three drying chambers are formed. With heat tubes,
The heat transfer pipe in the inlet drying chamber is arranged more roughly than the heat transfer pipes in the other drying chambers, the flow rate of fluidized steam or fluidized gas into the inlet drying chamber is increased, and the outlet drying is performed. The heat transfer tubes in the room are arranged more densely than the heat transfer tubes in the other drying chambers, and the flow rate of fluidized steam or fluidized gas into the outlet drying chamber is increased ,
Furthermore, the fluidized bed drying apparatus is characterized in that the heating temperature of the heat transfer tubes in the inlet drying chamber and the outlet drying chamber is set higher than that of the heat transfer tubes in other drying chambers . Oite to claim 1,
A fluidized bed drying apparatus characterized in that the temperature of the fluidized steam or fluidized gas in the inlet drying chamber and the outlet drying chamber is higher than the temperatures in other drying chambers. Oite to claim 1 or 2,
A fluidized bed drying apparatus, wherein the fluidized bed cross-sectional area of the outlet drying chamber is increased toward the upper side. A fluidized bed drying apparatus according to any one of claims 1 to 3 ,
A coal gasification furnace that processes the dry coal supplied from the fluidized bed drying device and converts it into gasification gas;
A gas turbine operated the gasification gas as fuel,
And steam turbines operated by the steam generated by the exhaust heat recovery boiler for introducing turbine exhaust gas from said gas turbine,
Gasification combined cycle system using coal, characterized in that it comprises a power generator connected to the gas turbine and / or the steam turbine.

Images