JP2013167417A - Fluidized bed drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the performance of drying moist fuel by increasing a heat transfer area of a heat transfer tube per volume in a fluidized bed, in a fluidized bed drying device.SOLUTION: A drying container 101 having a raw coal inlet 102 and a dried coal outlet 103, a fluidizing steam supply section 104 forming a fluidized bed S with raw coal by supplying fluidizing steam to a lower section of the drying container 101, and heat transfer tubes 106, 107, 108 heating the raw coal of the fluidized bed S by circulating the fluidizing steam therein. The heat transfer tubes 106, 107, 108 are connected at ends of two straight sections 121a, 121b, 121c, 121d, 121e, 121f, 123a, 123b, 123c, 123d, 123e, 123f through curved sections 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, 124e, and the plurality of heat transfer tubes 106a, 106b are disposed while being intersected with each other, and not aligned in the longitudinal direction.

Description

  The present invention relates to a fluidized bed drying apparatus for drying a material to be dried by fluidizing steam.

  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 is one described in Patent Document 1 below. The heat exchanger described in Patent Document 1 is an upright heat exchange tube in which a supply and return pipe for a drying heat medium is arranged at the bottom of a fluidized bed, and a concentric pipe for return is provided inside the supply and return pipe. Is formed.

US Pat. No. 5,940,987

  The fluidized bed drying apparatus heats and dries the raw coal in the fluidized bed by supplying a fluidizing gas to the inside and supplying a heating fluid to a heat transfer tube disposed in the fluidized bed. In this case, the heat transfer tube has a higher heating efficiency as the heat transfer area per volume increases, and the drying performance of the raw coal is improved. However, in this heat transfer tube, a straight pipe is bent and used as a U-shaped pipe, and the minimum radius of curvature of the pipe is determined due to the restriction of bending by a processing machine. Therefore, it becomes difficult to arrange heat transfer tubes densely in the fluidized bed, and it is difficult to improve the drying performance of raw coal by increasing the heat transfer area per volume in the heat transfer tubes. .

  This invention solves the subject mentioned above, and provides the fluidized-bed drying apparatus which can improve the drying performance of wet fuel by increasing the heat-transfer area of the heat-transfer tube per volume in a fluidized bed. For the purpose.

  In order to achieve the above object, the fluidized bed drying apparatus according to the present invention is capable of supplying wet fuel from the wet fuel supply section on one end side and drying the wet fuel heated and dried from the dry matter discharge section on the other end side. A drying container having a hollow shape capable of discharging an object, a fluidized steam supply unit that forms a fluidized bed with wet fuel by supplying fluidized steam to the drying container, and a heating medium to circulate inside the heat transfer tube A heating section that heats the wet fuel in the fluidized bed, and the heat transfer tube is formed by connecting ends of two straight portions with curved portions, and the heating section includes a plurality of the heat transfer tubes. Are intersected and the curved portions are arranged shifted in the longitudinal direction.

  Therefore, the plurality of heat transfer tubes intersect with each other and the curved portions are arranged to be displaced in the longitudinal direction so that the heating unit is configured, so that the curvature radius of the curved portion in the heat transfer tubes is constant, and the plurality of heat transfer tubes are in the fluidized bed. Can be arranged efficiently, and the drying performance of the wet fuel can be improved by increasing the heat transfer area of the heat transfer tube per volume in the fluidized bed.

  In the fluidized bed drying apparatus of the present invention, the heat transfer tube has a plurality of the straight portions and a plurality of the curved portions, and each curved portion connected to each end of the one straight portion has a predetermined angle. It is characterized by being bent.

  Therefore, a plurality of heat transfer tubes can be efficiently arranged in the fluidized bed without reducing the radius of curvature of the bends in the heat transfer tubes by bending and arranging the respective bent portions in the heat transfer tubes.

  In the fluidized bed drying apparatus of the present invention, the heating unit is characterized in that the plurality of curved portions in the heat transfer tube are arranged in a zigzag shape.

  Therefore, it is possible to efficiently use the limited space in the fluidized bed and efficiently arrange the plurality of heat transfer tubes while suppressing interference with the plurality of heat transfer tubes.

  In the fluidized bed drying apparatus of the present invention, the heating unit is arranged by combining a plurality of the heat transfer tubes so as to be opposite to the zigzag direction in the curved portions of the heat transfer tubes. Yes.

  Therefore, a plurality of heat transfer tubes can be efficiently arranged by combining them efficiently while suppressing interference with the plurality of heat transfer tubes.

  In the fluidized bed drying apparatus of the present invention, the heat transfer tube has an end connected to a header.

  Therefore, the structure can be simplified by supplying and discharging the heating medium to and from the heat transfer tube from the header in the same direction.

  According to the fluidized bed drying apparatus of the present invention, a heating unit that heats the wet fuel in the fluidized bed is provided by circulating a heating medium inside the heat transfer tube, and each end of the two straight portions is curved. The heating unit is configured by arranging a plurality of heat transfer tubes intersecting and the curved portion being displaced in the longitudinal direction, so that the curvature radius of the curved portion in the heat transfer tube is constant, and the flow A plurality of heat transfer tubes can be efficiently arranged in the bed, and the drying performance of the wet fuel can be improved by increasing the heat transfer area of the heat transfer tubes per volume in the fluidized bed.

FIG. 1 is a schematic side view showing a fluidized bed drying apparatus according to an embodiment of the present invention. FIG. 2 is a schematic rear view showing the fluidized bed drying apparatus of the present embodiment. FIG. 3 is a front view of the heat transfer tube in the fluidized bed drying apparatus of the present embodiment. FIG. 4 is a side view of the heat transfer tube in the fluidized bed drying apparatus of the present embodiment. FIG. 5 is a schematic configuration diagram of a combined coal gasification combined power generation facility to which the fluidized bed drying apparatus of the present embodiment is applied.

  Exemplary embodiments of a fluidized bed drying apparatus according to the present invention will be described below in detail with reference to the accompanying 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.

  FIG. 1 is a schematic side view showing a fluidized bed drying apparatus according to an embodiment of the present invention, FIG. 2 is a schematic rear view showing a fluidized bed drying apparatus of the present embodiment, and FIG. 3 is a fluidized bed of the present embodiment. FIG. 4 is a side view of the heat transfer tube in the fluidized bed drying apparatus of the present embodiment, and FIG. 5 is a coal gasification combined power generation facility to which the fluidized bed drying apparatus of the present embodiment is applied. FIG.

  The coal gasification combined power generation facility (IGCC: Integrated Coal Gasification Combined Cycle) of the present embodiment 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 purification device. 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 this embodiment, 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 coal 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 a present Example is demonstrated.

  In the coal gasification combined power generation facility 10 of the present 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, and 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.

  The fluidized bed drying apparatus 12 is a plug flow type drying apparatus, and as shown in FIGS. 1 and 2, a drying container 101, a raw coal charging port 102, a dry coal discharging port 103, and a fluidized steam supply. Section 104 (104a, 104b, 104c), gas discharge port 105, and heat transfer tubes (heating sections) 106, 107, 108.

  The drying container 101 has a hollow box shape, and a raw coal charging port 102 for charging raw coal is formed on one end side, and a dried product obtained by heating and drying raw coal is discharged to the lower portion on the other end side. A dry charcoal discharge port 103 is formed. 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 this case, the drying container 101 can adjust the amount of raw coal supplied from the raw coal inlet 102 to the inside by the coal feeder 22 (see FIG. 5). Moreover, the dry container 101 can adjust raw coal discharge | emission amount by adjusting the rotation speed of the rotary valve which is not shown in the dry charcoal discharge port 103 provided.

  Further, the drying container 101 is provided with a dispersion plate 109 having a plurality of openings at a predetermined distance from the bottom plate 101a in the lower portion, so that the wind box 110 is partitioned. The drying container 101 is provided with a fluidized steam supply unit 104 (104a, 104b, 104c) that supplies fluidized steam (superheated steam) to the bottom plate 101a via the wind box 110 and above the dispersion plate 109. Yes. Further, in the drying container 101, a gas discharge port 105 for discharging fluidized steam and generated steam is formed in the ceiling plate 101b on the dry coal discharge port 103 side.

  The drying vessel 101 is supplied with raw coal from the raw coal inlet 102 and fluidized steam is supplied from the fluidized steam supply unit 104 through the wind box 110 and the dispersion plate 109, so that the dispersion plate 109 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 includes a first drying chamber 111 provided on the upstream side in the flow direction of the raw coal, a second drying chamber 112 provided on the downstream side of the first drying chamber 111, and raw coal. And the third drying chamber 113 provided on the most downstream side in the flow direction.

  More specifically, in the drying container 101, the fluidized bed S is divided into a plurality of (in this embodiment, two) partition plates 114 and 115 in the flow direction of the raw coal. Charcoal passage openings 116 and 117 are formed. The partition plates 114 and 115 are arranged along a vertical direction orthogonal to the flow direction of the raw coal, and are arranged at predetermined intervals in the flow direction of the raw coal. It is attached to the inner wall surface. And each partition plate 114,115 is located so that a lower end part may be located in the dispersion plate 109 with a predetermined clearance, and an upper end part may be extended upwards from the fluidized bed S. FIG. That is, passage openings 116 and 117 having a predetermined height and width (opening area) are secured between the partition plates 114 and 115 and the dispersion plate 109, and the passage openings 116 and 117 are substantially The same opening area is set.

  As described above, the drying container 101 is divided into the first drying chamber 111, the second drying chamber 112, and the third drying chamber 113 by providing the partition plates 114 and 115. The drying chambers 111, 112, and 113 are In addition, communication is made above the partition plates 114 and 115. In this case, the first drying chamber 111 is a region (preheat drying region) in which the freeboard portion F1 and the fluidized bed S1 are formed and the initial drying of the raw coal is performed. In the second drying chamber 112, a free board portion F2 and a fluidized bed S2 are formed, and the second drying chamber 112 is an area (fixed rate drying area) where the raw coal is dried in the middle period. In the third drying chamber 113, a free board portion F3 and a fluidized bed S3 are formed, and the third drying chamber 113 is a region where the latter drying of raw coal is performed (decrease rate drying region).

  In this case, each of the drying chambers 111, 112, and 113 is set so that the floor area is substantially the same, but may be set to an optimum ratio according to the moisture content of raw coal, for example, 2 It is desirable to set the floor area of the drying chamber 112 to the maximum. That is, the first drying chamber 111 is a preheat drying region in which the drying rate of the raw coal is increased to a predetermined moisture content because the moisture content of the raw coal to be charged is high. Since the drying rate of the raw coal rises to a predetermined drying rate and becomes constant, the second drying chamber 112 is a constant rate drying region where the drying rate of the raw coal becomes constant. Since the drying rate of the raw coal is processed when the moisture content of the raw coal reaches a predetermined moisture content (limit moisture content), the third drying chamber 113 is a reduced rate drying region in which the drying rate of the raw coal decreases. is there. Therefore, the drying efficiency is improved by maximizing the volume of the second drying chamber 112 that is the constant rate drying region.

  The wind box 110 is divided into three wind boxes 110a, 110b, and 110c by partition members 118 and 119 so as to correspond to the three drying chambers 111, 112, and 113, and the three wind boxes 110a, 110b, Three fluidized steam supply sections 104a, 104b, and 104c are provided so as to correspond to 110c. That is, the partition members 118 and 119 are disposed below the partition plates 114 and 115. The fluidized steam supply units 104a, 104b, and 104c are connected to a fluidized steam supply pipe (not shown). By adjusting the opening of the flow rate adjustment valve provided in the fluidized steam supply pipe, the wind box The amount of fluidized steam supplied to 110a, 110b, 110c can be adjusted.

  That is, the drying container 101 is configured as a plug flow system so that the supplied raw coal is pushed out in the room. This extruding flow is a flow for extruding the raw coal in the fluidizing direction so that the raw coal does not diffuse in the fluidizing direction in the fluidized bed S.

  Further, the drying container 101 is provided with a plurality of heat transfer tubes 106, 107, and 108 that pass through the drying container 101 from the outside and circulate in the fluidized beds S1, S2, and S3 in the drying chambers 111, 112, and 113, respectively. Has been. The heat transfer tubes 106, 107, 108 are positioned so as to be embedded in the fluidized beds S1, S2, S3, and the raw coals of the fluidized beds S1, S2, S3 are formed by fluidized steam (superheated steam) flowing inside. Can be dried by heating. In this case, the temperature of the heat transfer tubes 106, 107, 108 can be adjusted by changing the pressure of the supplied superheated steam.

  Therefore, the raw coal supplied to the first drying chamber 111 is fluidized by the fluidized steam and heated by the heat transfer tube 106 to be dried. The raw coal initially dried in the first drying chamber 111 is moved to the second drying chamber 112 through the passage opening 116 below the partition plate 114, and is heated by the heat transfer tube 107 here. Medium-term dry. The raw coal dried in the second drying chamber 112 is moved to the third drying chamber 113 through the passage opening 117 at the bottom of the partition plate 115, where it is heated by the heat transfer tube 108. Late drying.

  Thereby, the raw coal forming the fluidized beds S1, S2, and S3 of the drying chambers 111, 112, and 113 sequentially moves between the fluidized beds S1, S2, and S3 from the upstream side through the passage openings 116 and 117. By doing so, it can be made an extruded flow, and it is dried without being diffused in the flow direction.

  By the way, in the fluidized bed drying apparatus 12 of the present embodiment, a fluidized steam supply unit 104 that supplies fluidized steam is provided in the drying container 101, and is transmitted to the fluidized beds S1, S2, and S3 through which the fluidized steam flows. Heat pipes 106, 107, and 108 are arranged, and the raw coal is flowed and heated by the fluidized steam supplied from the fluidized steam supply unit 104, and also flows through the heat transfer pipes 106, 107, and 108. Heated by fluidized steam. In this case, the heat transfer tubes 106, 107, 108 have a higher heating efficiency as the heat transfer area per volume increases, and the drying performance of the raw coal is improved. However, the heat transfer tubes 106, 107, and 108 are bent so that the straight portions and the curved portions are alternately positioned, and the minimum radius of curvature of the bent portions is limited due to bending restrictions by the processing machine. It has been decided. Therefore, it is difficult to densely arrange the heat transfer tubes 106, 107, 108 in the fluidized beds S1, S2, S3, and it is difficult to increase the heat transfer area per volume in the heat transfer tubes.

  Therefore, in this embodiment, as shown in FIGS. 3 and 4, the heat transfer tubes 106 (106 a, 106 b) are configured by connecting the ends of the two straight portions with curved portions, and a plurality of heat transfer tubes 106 are configured. (106a, 106b) are crossed and the curved portion is arranged shifted in the longitudinal direction. Although not shown, the heat transfer tubes 107 and 108 have the same configuration.

  That is, the heat transfer tube 106 includes a first heat transfer tube 106a and a second heat transfer tube 106b. The first heat transfer tube 106a includes six straight portions 121a, 121b, 121c, 121d, 121e, and 121f and five curved portions 122a, 122b, 122c, 122d, and 122e. The ends of the straight portions 121a and 121b are connected by the curved portion 122a, the ends of the straight portions 121b and 121c are connected by the curved portion 122b, and the ends of the straight portions 121c and 121d are connected by the curved portion 122c. The end portions of the straight portions 121d and 121e are connected by the bending portion 122d, and the end portions of the straight portions 121e and 121f are connected by the bending portion 122e.

  In the first heat transfer tube 106a, five curved portions 122a, 122b, 122c, 122d, 122e are bent and arranged with a predetermined angle α. That is, as viewed from the side (FIG. 4), the first heat transfer tube 106a is bent at a predetermined angle α, and the curved portion 122b and the curved portion 122c are bent at a predetermined angle α. The portion 122c and the bending portion 122d are bent at a predetermined angle α, and the bending portion 122d and the bending portion 122e are bent at a predetermined angle α. In this case, the bending portions 122a, 122b, 122c, 122d, and 122e are arranged in a zigzag shape as a whole with the bending directions of adjacent ones being reversed.

  Further, the second heat transfer tube 106b includes six straight portions 123a, 123b, 123c, 123d, 123e, and 123f, and five curved portions 124a, 124b, 124c, 124d, and 124e, in substantially the same manner as the first heat transfer tube 106a. It is composed of The ends of the straight portions 123a and 123b are connected by the bending portion 124a, the ends of the straight portions 123b and 123c are connected by the bending portion 124b, and the ends of the straight portions 123c and 123d are connected by the bending portion 124c. The end portions of the straight portions 123d and 123e are connected by the curved portion 124d, and the end portions of the straight portions 123e and 123f are connected by the curved portion 124e.

  In the second heat transfer tube 106b, five curved portions 124a, 124b, 124c, 124d, and 124e are bent and arranged with a predetermined angle β. That is, as viewed from the side (FIG. 4), the first heat transfer tube 106a bends at a predetermined angle β at the bending portion 124a and the bending portion 124b, and bends at a predetermined angle β at the bending portion 124b and the bending portion 124c. The portion 124c and the bending portion 124d are bent at a predetermined angle β, and the bending portion 124d and the bending portion 124e are bent at a predetermined angle β. In this case, the bending portions 124a, 124b, 124c, 124d, and 124e are arranged in a zigzag shape as a whole with the bending directions of adjacent ones being reversed.

  Further, the first heat transfer tube 106a and the second heat transfer tube 106b are such that the bending direction of the bending portions 122a, 122b, 122c, 122d, and 122e is opposite to the bending direction of the bending portions 124a, 124b, 124c, 124d, and 124e. The heat transfer tubes 106a and 106b are combined and arranged.

  In this case, the curved portions 122a and 124a are arranged so as to cross and deviate in the longitudinal direction of the straight portions 121a, 121b, 123a, and 123b, and the curved portions 122b and 124b are the longitudinal lengths of the straight portions 121b, 121c, 123b, and 123c. The curved portions 122c and 124c are arranged so as to cross each other while being shifted in the longitudinal direction of the straight portions 121c, 121d, 123c, and 123d, and the curved portions 122d and 124d are arranged so as to intersect with each other. 121e, 123d, 123e are arranged so as to intersect with each other in the longitudinal direction, and the curved portions 122e, 124e are arranged so as to intersect with each other while being displaced in the longitudinal direction of the straight portions 121e, 121f, 123e, 123f.

  Further, the end portions of the first heat transfer tube 106 a and the second heat transfer tube 106 b are connected to the headers 125 and 126. That is, the first heat transfer tube 106 a has an end portion of the straight portion 121 a connected to the supply header 125 and an end portion of the straight portion 121 f connected to the discharge header 126. Further, the second heat transfer tube 106 b has an end portion of the straight portion 123 a connected to the supply header 125 and an end portion of the straight portion 123 f connected to the discharge header 126.

  The first heat transfer tube 106a and the second heat transfer tube 106b are configured such that the curved portions 124a, 124b, 124c, 124d, and 124e are shifted toward the headers 125 and 126 with respect to the curved portions 124a, 124b, 124c, 124d, and 124e. Since they are arranged, the overall lengths of both are almost the same.

  Further, the bending angle α of each bending portion 122a, 122b, 122c, 122d, 122e in the first heat transfer tube 106a and the bending angle β of each bending portion 124a, 124b, 124c, 124d, 124e in the second heat transfer tube 106b are as follows. The angles are preferably the same, but may be different.

  In this embodiment, a plurality of heat transfer tubes 106 including the first heat transfer tubes 106a and the second heat transfer tubes 106b are arranged and inserted into the fluidized bed S1 from the side of the drying vessel 101 as shown in FIG. doing. In this case, each head 125, 126 is fixed to the side of the drying container 101, and may be detachable in consideration of maintenance.

  In this embodiment, the heat transfer tube 106 is composed of the first heat transfer tube 106a and the second heat transfer tube 106b, and the two heat transfer tubes 106a and 106b intersect with each other and the curved portion is shifted in the longitudinal direction. Three or more heat transfer tubes may be crossed and the curved portion may be shifted in the longitudinal direction. In addition, the number and length of the straight portions and the curved portions, the bending angle of the curved portions, and the like may be set in consideration of the size of the fluidized bed S and the like.

  Here, the entire operation of the fluidized bed drying apparatus 12 of the present embodiment will be described.

  In the fluidized bed drying device 12, as shown in FIGS. 1 and 2, the raw coal is supplied from the raw coal inlet 102 to the drying container 101 and flows from the fluidized steam supply unit 104 through the dispersion plate 109. When the vaporized steam is supplied, fluidized beds S1, S2, and S3 having a predetermined thickness are formed above the dispersion plate 109. The raw coal moves through the fluidized beds S1, S2, and S3 to the dry coal discharge port 103 side by the fluidized steam, and at this time, the raw coal is heated and dried by receiving heat from the heat transfer tubes 106, 107, and 108.

  That is, when raw coal is supplied from the raw coal inlet 102, first, in the first drying chamber 111, fluidized steam is supplied from the fluidized steam supply unit 104 a through the dispersion plate 109, and heat is transferred from the heat transfer tube 106. By receiving, it is dried while flowing in the fluidized bed S1. Next, the raw coal that has been initially dried in the first drying chamber 111 flows into the second drying chamber 112 through the passage opening 116 of the partition plate 114. In the second drying chamber 112, fluidized steam is supplied from the fluidized steam supply unit 104 b through the dispersion plate 109 and receives heat from the heat transfer tube 107, so that it is dried while flowing in the fluidized bed S <b> 2. The raw coal that has been subjected to medium-term drying in the second drying chamber 112 flows into the third drying chamber 113 through the passage opening 117 of the partition plate 115. In the third drying chamber 113, fluidized steam is supplied from the fluidized steam supply unit 104c through the dispersion plate 109, and is also dried while flowing in the fluidized bed S3 by receiving heat from the heat transfer tube. In this way, the raw coal flows in the fluidized beds S1, S2, S3 by the fluidized steam supplied while being heated by the heat transfer tubes 106, 107, 108, and diffuses in the flow direction as an extruded flow. Without drying.

  At this time, in each of the fluidized beds S1, S2, and S3 of the drying chambers 111, 112, and 113, the fluidized steam flows in the heat transfer tubes 106, 107, and 108, so that the heat of the fluidized steam is transferred to the heat transfer tubes. The raw coal is transferred to the raw coal through 106, 107, and 108, and is heated and dried. In this case, since the heat transfer tubes 106, 107, 108 are arranged so that the two heat transfer tubes intersect with each other, the heat transfer area per volume is increased, the heating efficiency is improved, and the drying performance of the raw coal is improved. To do.

  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 bed S rises together with the fluidized steam. It flows to the discharge port 103 side and is discharged from the gas discharge port 105 to the outside.

  As described above, in the fluidized bed drying apparatus of the present embodiment, the raw coal is obtained by supplying fluidized steam to the drying vessel 101 having the raw coal inlet 102 and the dry coal outlet 103 and the lower portion of the drying vessel 101. In addition, a fluidized steam supply unit 104 that forms the fluidized bed S, and heat transfer tubes 106, 107, and 108 that heat the raw coal of the fluidized bed S by circulating the fluidized steam therein are provided. , 108 are linear portions 121a, 121b, 121c, 121d, 121e, 121f, 123a, 123b, 123c, 123d, 123e, 123f, and the end portions are curved portions 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, and 124e are connected to each other, and the plurality of heat transfer tubes 106a and 106b intersect with each other and are displaced in the longitudinal direction. That.

  Therefore, the plurality of heat transfer tubes 106a and 106b intersect and the curved portions 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, and 124e are arranged so as to be shifted in the longitudinal direction. The curvature radii of the curved portions 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, 124e in 106b are made constant, and a plurality of heat transfer tubes 106, 107, 108 are made efficient in the fluidized beds S1, S2, S3. It becomes possible to arrange well, and the drying performance of raw coal can be improved by increasing the heat transfer area of the heat transfer tubes 106, 107, 108 per volume in the fluidized beds S1, S2, S3.

  Further, in the fluidized bed drying apparatus of the present embodiment, the heat transfer tubes 106a and 106b are configured such that the curved portions 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, and 124e are bent at a predetermined angle. . Therefore, the plurality of heat transfer tubes 106, 107 in the fluidized bed S are not reduced without reducing the curvature radii of the curved portions 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, 124e in the heat transfer tubes 106a, 106b. , 108 can be arranged efficiently.

  In the fluidized bed drying apparatus of the present embodiment, the plurality of curved portions 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, and 124e in the heat transfer tubes 106a and 106b are arranged in a zigzag shape. And it arrange | positions combining so that the zigzag direction in each curved part 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, 124e of each heat exchanger tube 106a, 106b may become a reverse direction. Therefore, while suppressing interference with the plurality of heat transfer tubes 106a and 106b, the plurality of heat transfer tubes 106a and 106b can be efficiently arranged by efficiently using the limited space in the fluidized bed S and combining them appropriately. can do.

  Further, in the fluidized bed drying apparatus of the present embodiment, the end portions of the heat transfer tubes 106 a and 106 b are connected to the headers 125 and 126. Therefore, the structure can be simplified by supplying and discharging the fluidized steam to the heat transfer tubes 106a and 106b from the same direction.

  In the embodiment described above, the inside of the drying container 101 is divided into three drying chambers 111, 112, and 113, but may be two drying chambers or four or more drying chambers. Further, the configuration and arrangement of the shape of the drying container 101, the raw coal inlet 102, the dry coal outlet 103, the fluidized steam supply unit 104, the gas outlet 105, and the heat transfer tubes 106, 107, 108 are described in each embodiment. It is not limited and can be changed as appropriate according to the installation location and application of the fluidized bed drying device 12.

  In the above-described embodiments, low-grade coal is used as the wet fuel, but even high-grade coal can be applied, and is not limited to coal, and can be used as a renewable organic organic resource. For example, it is also possible to use thinned wood, waste wood, driftwood, grass, waste, sludge, tires, and recycled fuel (pellets or chips) using these as raw materials.

  In the above-described embodiment, the fluidized steam is supplied into the drying container 101. However, air or the like may be applied as the fluidized steam. In addition, although the passage openings 116 and 117 are provided in the middle portion of the partition plates 114 and 115 in the vertical direction, the passage openings 116 and 117 may be provided in the lower portion of the partition plates 114 and 115 in the vertical direction. It is not limited to the position of the parts 116 and 117.

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 103 Dry coal discharge port 104 Fluidized steam supply unit 105 Gas discharge port 106, 107, 108 Heat transfer tube (heating unit)
111 1st drying chamber 112 2nd drying chamber 113 3rd drying chamber 114, 115 Partition plate 116,117 Passing opening part 106a 1st heat exchanger tube 106b 2nd heat exchanger tube 121a, 121b, 121c, 121d, 121e, 121f, 123a, 123b, 123c, 123d, 123e, 123f Straight portion 122a, 122b, 122c, 122d, 122e, 124a, 124b, 124c, 124d, 124e Bending portion 125, 126 Header F, F1, F2, F3 Free board portion S, S1, S2, S3 fluidized bed

Claims (5)

A drying container having a hollow shape capable of discharging wet fuel from the wet fuel charging portion on one end side and discharging dry matter obtained by heating and drying the wet fuel from the dry matter discharging portion on the other end side;
A fluidized steam supply unit that forms a fluidized bed with wet fuel by supplying fluidized steam to the drying vessel;
A heating unit for heating the wet fuel in the fluidized bed by circulating a heating medium inside the heat transfer tube;
With
In the heat transfer tube, each end of two straight portions is connected by a curved portion, and the heating portion is arranged such that a plurality of the heat transfer tubes intersect and the curved portion is shifted in the longitudinal direction.
A fluidized bed drying apparatus.   The heat transfer tube includes a plurality of straight portions and a plurality of curved portions, and each curved portion connected to each end of the one straight portion is bent and arranged at a predetermined angle. The fluidized bed drying apparatus according to claim 1.   The fluidized bed drying apparatus according to claim 2, wherein the heating unit includes a plurality of the curved portions of the heat transfer tube arranged in a zigzag shape.   4. The fluidized bed according to claim 3, wherein the heating unit is arranged in combination with the plurality of heat transfer tubes so as to be opposite to each other in a zigzag direction in the curved portions of the heat transfer tubes. Drying equipment.   The fluidized bed drying apparatus according to any one of claims 1 to 4, wherein an end of the heat transfer tube is connected to a header.

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