JP5959879B2 - Drying system - Google Patents

Description

  The present invention relates to a drying system equipped with a fluidized bed drying device that dries while flowing wet fuel such as lignite.

  Conventionally, a fluidized bed dryer that dries a wet raw material such as coal is known (see, for example, Patent Document 1). In this fluidized bed dryer, fluidized gas is blown from the lower side of the gas dispersion plate to form a fluidized bed on the gas dispersion plate.

Japanese Patent Laid-Open No. 61-250096

  By the way, in a fluidized bed drying apparatus using fluidized steam as fluidized gas, the fluidized steam is condensed and condensed water is generated by supplying low temperature wet fuel on the fuel supply side of the fluidized bed drying apparatus. However, the wet fuel tends to aggregate due to the condensed water. When the wet fuel is aggregated, the wet fuel becomes difficult to flow in the fluidized bed drying apparatus, and there is a possibility that the poor flow of the wet fuel occurs.

  Then, this invention makes it a subject to provide the drying system which suppresses aggregation of wet fuel and can make wet fuel flow suitably.

  The drying system of the present invention is supplied to a fluidized bed drying apparatus that dries wet fuel while forming a fluidized bed inside by flowing the wet fuel supplied to the inside with fluidized steam, and the fluidized bed drying apparatus. And a preheating device for preheating the wet fuel.

  According to this configuration, the wet fuel can be preheated by the preheating device, and the preheated wet fuel can be supplied to the fluidized bed drying device. For this reason, when the preheated wet fuel is supplied to the fluidized bed drying device, the fluidized vapor in the fluidized bed drying device is difficult to condense. Thereby, aggregation of wet fuel due to condensation of fluidized vapor can be suppressed, occurrence of defective flow of wet fuel can be suppressed, and the flow of wet fuel in the fluidized bed drying apparatus can be made suitable. .

  In this case, it is preferable that the preheating device is a fluidized bed preheating device that preheats wet fuel while forming a fluidized bed inside by flowing the wet fuel supplied to the inside with a fluidizing gas.

  According to this configuration, the wet fuel can be efficiently preheated while flowing.

  In this case, it is preferable that a non-condensable gas is supplied to the fluidized bed preheating device as a fluidizing gas.

  According to this configuration, since the non-condensable gas is supplied as the fluidized gas, the occurrence of condensation of the fluidized gas can be suppressed in the fluidized bed preheating device. Thereby, the aggregation of the wet fuel due to the condensation of the fluidized gas can be suppressed, the occurrence of the poor flow of the wet fuel can be suppressed, and the flow of the wet fuel in the fluidized bed preheating device can be made suitable. .

  In this case, it is preferable that the preheating device is a transfer type preheating device that preheats the wet fuel while transferring the wet fuel supplied therein.

  According to this configuration, the wet fuel can be preheated while being transferred. For this reason, it can be set as the structure which served as the transfer of wet fuel, and preheating by providing in the movement path | route of wet fuel.

  In this case, the preheating device has a heating unit that heats the wet fuel, and the preheating temperature measuring device that measures the preheating temperature of the wet fuel preheated by the preheating device, and the preheating temperature measured by the preheating temperature measuring device is the steam. It is preferable to further include a control device that controls the heating temperature of the heating unit so as to reach the saturation temperature.

  According to this configuration, the preheating temperature of the wet fuel can be set to the saturation temperature of the steam by controlling the heating temperature of the heating unit. For this reason, the fluidized steam is more difficult to condense when the fluidized bed drying apparatus is supplied with wet fuel preheated to the steam saturation temperature.

  In this case, the wet fuel preferably has a moisture content of 50% or more.

  According to this configuration, the wet fuel having a high water content can be dried while suitably flowing in the fluidized bed drying apparatus without agglomerating.

  According to the drying system of the present invention, the wet fuel is preheated in the preheating device, so that the aggregation of the wet fuel can be suppressed in the fluidized bed drying device, and the wet fuel can be dried while flowing appropriately.

FIG. 1 is a schematic configuration diagram of a coal gasification combined power generation facility to which a drying system according to a first embodiment is applied. FIG. 2 is a schematic configuration diagram schematically illustrating the drying system according to the first embodiment. FIG. 3 is a schematic configuration diagram schematically illustrating a drying system according to the second embodiment.

  Hereinafter, a drying system according to the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following examples. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic configuration diagram of a coal gasification combined power generation facility to which a drying system according to a first embodiment is applied. An integrated coal gasification combined cycle (IGCC) 100 to which the drying system 1 of Example 1 is applied employs an air combustion method in which coal gas is generated in a gasification furnace using air as an oxidant, Coal gas after being refined by a gas purifier is supplied to gas turbine equipment as fuel gas to generate electricity. That is, the combined coal gasification combined power generation facility 100 according to the first embodiment is an air combustion type (air blowing) power generation facility. In this case, lignite is used as wet fuel supplied to the gasifier. The wet fuel has a moisture content of 50% or more, and a wet fuel having a moisture content of around 60% is mainly used.

  In Example 1, lignite was used as the wet fuel, but low-grade coal including sub-bituminous coal, peat such as sludge, etc. may be applied as long as the moisture content is high. Even charcoal is applicable. In addition, the wet fuel is not limited to coal such as lignite, but may be biomass used as organic resources derived from renewable organisms. For example, thinned wood, waste wood, driftwood, grass, waste, It is also possible to use sludge, tires, and recycled fuel (pellets and chips) made from these raw materials.

  In Example 1, as shown in FIG. 1, the coal gasification combined power generation facility 100 includes a coal supply device 111, a drying system 1, a pulverized coal machine 113, a coal gasification furnace 114, a char recovery device 115, and a gas purification device 116. A gas turbine facility 117, a steam turbine facility 118, a generator 119, and a heat recovery steam generator (HRSG) 120.

  The coal feeder 111 includes a raw coal bunker 121, a coal feeder 122, and a crusher 123. The raw coal bunker 121 can store lignite, and drops a predetermined amount of lignite into the coal feeder 122. The coal feeder 122 transports the brown coal dropped from the raw coal bunker 121 by a conveyor or the like and drops it on the crusher 123. The crusher 123 finely pulverizes the dropped lignite into fine particles.

  Although the details will be described later, the drying system 1 includes a preheating device 10 and a fluidized bed drying device 11, and preheats the lignite charged from the coal supply device 111 with the preheating device 10, and the preheated lignite. Moisture contained in lignite is removed by heating and drying with a heat transfer tube 44 while flowing with fluidized steam in the fluidized bed drying device 11. The fluidized bed drying apparatus 11 is connected to a cooler 131 that cools the discharged dried lignite (dry coal). The cooler 131 is connected to a dry charcoal bunker 132 for storing cooled dry charcoal. Further, a dry coal cyclone 133 and a dry coal electric dust collector 134 are connected to the fluidized bed dryer 11 as a dust collector 139 for separating dry coal particles from exhaust gas discharged to the outside. The dry coal particles separated from the exhaust gas in the dry coal cyclone 133 and the dry coal electrostatic precipitator 134 are stored in the dry coal bunker 132. The exhaust gas from which the dry coal is separated by the dry coal electrostatic precipitator 134 is compressed by the steam compressor 135 and then supplied as a heat medium to the heat transfer tube 44 of the fluidized bed drying device 11.

  The pulverized coal machine 113 produces pulverized coal by pulverizing the lignite (dried coal) dried by the fluidized bed dryer 11 into fine particles. In other words, when the dry coal stored in the dry coal bunker 132 is dropped by the coal feeder 136, the pulverized coal machine 113 converts the dry coal into pulverized coal having a predetermined particle size or less. The pulverized coal after being pulverized by the pulverized coal machine 113 is separated from the conveying gas by the pulverized coal bag filters 137a and 137b and stored in the pulverized coal supply hoppers 138a and 138b.

  The coal gasifier 114 is supplied with pulverized coal processed by the pulverized coal machine 113 and supplied with char (unburned coal) recovered by the char recovery device 115.

  The coal gasification furnace 114 is connected to a compressed air supply line 141 from a gas turbine facility 117 (compressor 161), and can supply compressed air compressed by the gas turbine facility 117. The air separation device 142 separates and generates nitrogen and oxygen from air in the atmosphere. A first nitrogen supply line 143 is connected to the coal gasifier 114, and a pulverized coal supply hopper is connected to the first nitrogen supply line 143. Charging lines 144a and 144b from 138a and 138b are connected. The second nitrogen supply line 145 is also connected to the coal gasifier 114, and the char return line 146 from the char recovery device 115 is connected to the second nitrogen supply line 145. Further, the oxygen supply line 147 is connected to the compressed air supply line 141. 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 114 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. Note that the coal gasification furnace 114 is provided with a foreign matter removing device 148 that removes foreign matter mixed with pulverized coal. In this case, the coal gasification furnace 114 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 114 is provided with a gas generation line 149 for combustible gas toward the char recovery device 115, and can discharge combustible gas containing char. In this case, by providing a gas cooler in the gas generation line 149, the combustible gas may be cooled to a predetermined temperature and then supplied to the char recovery device 115.

  The char recovery device 115 includes a dust collector 151 and a supply hopper 152. In this case, the dust collector 151 is constituted by one or a plurality of bag filters or cyclones, and can separate the char contained in the combustible gas generated in the coal gasification furnace 114. The combustible gas from which the char has been separated is sent to the gas purifier 116 through the gas discharge line 153. The supply hopper 152 stores the char separated from the combustible gas by the dust collector 151. A bin may be disposed between the dust collector 151 and the supply hopper 152, and a plurality of supply hoppers 152 may be connected to the bin. A char return line 146 from the supply hopper 152 is connected to the second nitrogen supply line 145.

The gas purification device 116 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 115. The gas purifier 116 purifies the combustible gas to produce fuel gas, and supplies it to the gas turbine equipment 117. In this gas purifier 116, 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 117 includes a compressor 161, a combustor 162, and a turbine 163, and the compressor 161 and the turbine 163 are connected by a rotating shaft 164. The combustor 162 has a compressed air supply line 165 connected from the compressor 161, a fuel gas supply line 166 connected from the gas purification device 116, and a combustion gas supply line 167 connected to the turbine 163. Further, the gas turbine equipment 117 is provided with a compressed air supply line 141 extending from the compressor 161 to the coal gasification furnace 114, and a booster 168 is interposed in the compressed air supply line 141. Therefore, in the combustor 162, the compressed air supplied from the compressor 161 and the fuel gas supplied from the gas purifier 116 are mixed and burned, and the rotating shaft 164 is rotated by the generated combustion gas in the turbine 163. By doing so, the generator 119 can be driven.

  The steam turbine equipment 118 has a turbine 169 connected to the rotating shaft 164 in the gas turbine equipment 117, and the generator 119 is connected to the base end portion of the rotating shaft 164. The exhaust heat recovery boiler 120 is provided in the exhaust gas line 170 from the gas turbine equipment 117 (the turbine 163), and generates steam by exchanging heat between air and high-temperature exhaust gas. Therefore, the exhaust heat recovery boiler 120 is provided with a steam supply line 171 and a steam recovery line 172 between the turbine 169 of the steam turbine equipment 118, and a condenser 173 is provided in the steam recovery line 172. Yes. Therefore, in the steam turbine equipment 118, the turbine 169 is driven by the steam supplied from the exhaust heat recovery boiler 120, and the generator 119 can be driven by rotating the rotating shaft 164.

  The exhaust gas from which heat has been recovered by the exhaust heat recovery boiler 120 is removed of harmful substances by the gas purification device 174, and the purified exhaust gas is discharged from the chimney 175 to the atmosphere.

  Here, the action | operation of the coal gasification combined cycle power generation equipment 100 of Example 1 is demonstrated.

  In the combined coal gasification combined power generation facility 100 of the first embodiment, raw coal (brown coal) is stored in the raw coal bunker 121 by the coal feeder 111, and the lignite in the raw coal bunker 121 is crushed by the coal feeder 122. It is dropped to 123, where it is crushed to a predetermined size. The crushed lignite is preheated and dried by the drying system 1, cooled by the cooler 131, and stored in the dry coal bunker 132. Further, the exhaust gas discharged from the fluidized bed drying device 11 is separated from dried coal particles by the dried coal cyclone 133 and the dried coal electrostatic precipitator 134 and compressed by the steam compressor 135 before being transferred to the fluidized bed drying device 11. It is returned to the heat tube 44 as a heat medium. On the other hand, dry coal particles separated from the steam are stored in the dry coal bunker 132.

  The dry coal stored in the dry coal bunker 132 is supplied to the pulverized coal machine 113 by the coal feeder 136, where it is pulverized into fine particles to produce pulverized coal, and the pulverized coal bag filters 137a and 137b are used. And stored in pulverized coal supply hoppers 138a and 138b. The pulverized coal stored in the pulverized coal supply hoppers 138 a and 138 b is supplied to the coal gasification furnace 114 through the first nitrogen supply line 143 by nitrogen supplied from the air separation device 142. Further, the char recovered by the char recovery device 115 described later is supplied to the coal gasifier 114 through the second nitrogen supply line 145 by nitrogen supplied from the air separation device 142. Further, compressed air extracted from a gas turbine facility 117 described later is boosted by a booster 168 and then supplied to the coal gasifier 114 through the compressed air supply line 141 together with oxygen supplied from the air separation device 142.

  In the coal gasification furnace 114, the supplied pulverized coal and char are combusted by compressed air (oxygen), and the pulverized coal and char are gasified, so that combustible gas (coal gas) mainly containing carbon dioxide is obtained. Can be generated. This combustible gas is discharged from the coal gasifier 114 through the gas generation line 149 and sent to the char recovery device 115.

  In the char recovery device 115, the combustible gas is first supplied to the dust collector 151, and the dust collector 151 separates the char contained in the combustible gas. The combustible gas from which the char has been separated is sent to the gas purifier 116 through the gas discharge line 153. On the other hand, the fine char separated from the combustible gas is deposited on the supply hopper 152, returned to the coal gasifier 114 through the char return line 146, and recycled.

  The combustible gas from which the char has been separated by the char recovery device 115 is gas purified by removing impurities such as sulfur compounds and nitrogen compounds by the gas purification device 116 to produce fuel gas. In the gas turbine equipment 117, when the compressor 161 generates compressed air and supplies the compressed air to the combustor 162, the combustor 162 is supplied from the compressed air supplied from the compressor 161 and the gas purifier 116. Combustion gas is generated by mixing with fuel gas and combusting, and the turbine 163 is driven by this combustion gas, so that the generator 119 is driven via the rotating shaft 164 to generate power.

  The exhaust gas discharged from the turbine 163 in the gas turbine facility 117 generates steam by exchanging heat with air in the exhaust heat recovery boiler 120, and supplies the generated steam to the steam turbine facility 118. . In the steam turbine equipment 118, the turbine 169 is driven by the steam supplied from the exhaust heat recovery boiler 120, whereby the generator 119 can be driven via the rotating shaft 164 to generate power.

  Thereafter, in the gas purification device 174, harmful substances in the exhaust gas discharged from the exhaust heat recovery boiler 120 are removed, and the purified exhaust gas is released from the chimney 175 to the atmosphere.

  Hereinafter, the drying system 1 in the coal gasification combined power generation facility 100 described above will be described in detail. FIG. 2 is a schematic configuration diagram schematically illustrating the drying system according to the first embodiment. The drying system 1 of Example 1 preheats the lignite input by the coal feeder 111, and heat-drys the preheated lignite while flowing it with fluidized steam.

  As shown in FIG. 2, the drying system 1 includes a preheating device 10 and a fluidized bed drying device 11. The preheating device 10 is a fluidized bed preheating device that forms a fluidized bed 15 therein. The preheating device 10 includes a preheating container 21 into which lignite is supplied and a preheating gas dispersion plate 22 provided inside the preheating container 21. The preheating container 21 is formed in a rectangular box shape. The preheating gas dispersion plate 22 has a space inside the preheating container 21 in a preheating wind chamber 23 located on the lower side in the vertical direction (lower side in the figure) and a preheating chamber 24 located on the upper side in the vertical direction (upper side in the figure). It is divided into. A number of through holes are formed in the preheating gas dispersion plate 22, and air or a non-condensable gas such as combustion exhaust gas burned in the combustor 162 is supplied as a fluidizing gas to the preheating wind chamber 23. The

  The preheating chamber 24 of the preheating vessel 21 has a lignite inlet 26 for introducing lignite, a lignite outlet 27 for discharging preheated lignite, a gas outlet 28 for discharging fluidized gas and generated steam, and a preheating transmission. A heat pipe 29 is provided.

  The brown coal inlet 26 is formed at the upper end of one end side (the left side in the figure) of the preheating chamber 24. A coal supply device 111 is connected to the lignite charging unit 26, and the lignite supplied from the coal supply device 111 is supplied to the preheating chamber 24.

  The brown coal discharge port 27 is formed in the lower part of the other end side (the right side in the figure) of the preheating chamber 24. From the lignite discharge port 27, the lignite preheated in the preheating chamber 24 is discharged, and the discharged lignite is transferred to the lignite transfer device 30 and supplied toward the fluidized bed drying device 11.

  The gas discharge port 28 is formed in the upper part on the other end side of the preheating chamber 24. The gas discharge port 28 discharges the generated steam generated from the preheating chamber 24 together with the fluidized gas supplied to the preheating chamber 24 during the preheating of the lignite. The fluidized gas and generated steam discharged from the gas discharge port 28 are supplied to a dust collector (not shown) different from the dust collector 139 described above.

  The preheating heat transfer tube 29 is provided inside the fluidized bed 15 formed in the preheating chamber 24, and functions as a heating unit that heats the wet fuel. A heating medium is supplied to the preheating heat transfer tube 29. The heating medium for heating may be the drying steam used in the heat transfer tube 44 of the fluidized bed drying apparatus 11 described later, and is not particularly limited. At this time, the temperature of the heating heat medium supplied to the preheating heat transfer tube 29 is controlled by the control unit 60. And when the heating medium is supplied into the pipe, the preheating heat transfer pipe 29 preheats the lignite by heating the lignite of the fluidized bed 15 and raising the temperature of the lignite to a predetermined preheating temperature. Thereafter, the heating medium used for preheating is discharged to the outside of the preheating chamber 24.

  Therefore, in the preheating device 10, the lignite supplied to the preheating chamber 24 via the lignite inlet 26 flows by the fluidized gas supplied via the preheating gas dispersion plate 22, thereby entering the preheating chamber 24. A fluidized bed 15 is formed. The lignite that has become the fluidized bed 15 is heated by the preheating heat transfer tube 29, and the moisture contained in the lignite becomes generated steam and is discharged from the gas outlet 28 together with the fluidizing gas. The lignite heated to a predetermined preheating temperature is discharged from the lignite discharge port 27.

  The lignite discharged from the lignite discharge port 27 is supplied to the lignite transport device 30. The lignite conveying device 30 conveys the lignite discharged from the lignite discharge port 27 toward the fluidized bed drying device 11. The brown coal conveying device 30 is, for example, a conveyor conveying device having a conveyor belt, and conveys the lignite to the fluidized bed drying device 11 by rotating the lignite placed on the conveyor belt around the conveyor belt. In addition, the lignite transfer device 30 is not limited to the conveyor transfer device, and may be any device as long as it can transfer lignite.

  The fluidized bed drying device 11 includes a drying container 35 into which lignite is supplied. The drying container 35 is formed in a rectangular box shape, and the lignite supplied to the inside flows in a flow direction from one end side (left side in the figure) to the other end side (right side in the figure). A gas dispersion plate 36 is provided inside the drying container 35. The gas distribution plate 36 divides the space inside the drying container 35 into a wind chamber 37 located on the lower side in the vertical direction (lower side in the drawing) and a drying chamber 38 located on the upper side in the vertical direction (upper side in the drawing). Yes. A large number of through holes are formed in the gas dispersion plate 36, and fluidized steam is introduced into the wind chamber 37.

  A plurality of drying chamber partition plates 39 for partitioning the drying chamber 38 and a plurality of wind chamber partition plates 40 for partitioning the air chamber 37 are provided inside the drying container 35. In the first embodiment, two drying chamber partition plates 39 are provided, and along the flow direction, the drying chamber 38 is divided into an upstream drying chamber 38a, a midstream drying chamber 38b, and a downstream drying chamber 38c. It is divided into. Each drying chamber partition plate 39 is provided with a gap between the upper end portion in the vertical direction and the upper portion of the drying chamber 38 and with a gap between the lower end portion and the gas dispersion plate 36. For this reason, the lignite dried in the upstream drying chamber 38a passes through a gap formed on the lower end side of the drying chamber partition plate 39 and is supplied to the intermediate drying chamber 38b, and then the downstream drying chamber. 38c.

  Similarly, in the first embodiment, two wind chamber partition plates 40 are provided, and along the flow direction, the wind chamber 37 is divided into an upstream wind chamber 37a, a midstream wind chamber 37b, and a downstream wind. It is divided into the chamber 37c. Each wind chamber partition plate 40 has an upper end portion in the vertical direction connected to the upper portion of the wind chamber 37 and a lower end portion connected to the lower portion of the wind chamber 37.

  The drying container 35 has a brown coal inlet 41 for charging lignite, a dry coal outlet 42 for discharging dry coal obtained by heating and drying lignite, and a steam outlet 43 for discharging fluidized steam and generated steam generated during drying. And the heat exchanger tube 44 which heats lignite is provided.

  The brown coal inlet 41 is formed at the upper part of one end side (the left side in the drawing) of the drying chamber 38a on the upstream side. The lignite transfer device 30 is connected to the lignite input port 41, and the lignite transferred from the lignite transfer device 30 is input to the drying chamber 38a on the upstream side.

  The dry charcoal discharge port 42 is formed in a lower portion on the other end side (right side in the drawing) in the downstream drying chamber 38c. The brown coal dried in the drying chamber 38 is discharged as dry coal from the dry coal discharge port 42, and the discharged dry coal is supplied toward the cooler 131 described above.

  The steam discharge ports 43 are respectively formed in the upper part of the drying chamber 38a on the upstream side, the drying chamber 38b on the middle stream side, and the drying chamber 38c on the downstream side. The steam discharge port 43 discharges generated steam generated by heating the lignite together with the fluidized steam supplied to the drying chamber 38 when the lignite is dried. The fluidized steam and generated steam discharged from the steam discharge port 43 are supplied to the dust collector 139 and then supplied to the steam compressor 135.

  The heat transfer tubes 44 are respectively provided inside the fluidized bed 18 formed in the upstream drying chamber 38a, the midstream drying chamber 38b, and the downstream drying chamber 38c. The heat transfer pipe 44 is connected to the outflow side of the steam compressor 135, and the steam compressed by the steam compressor 135 is supplied into the pipe as drying steam. For this reason, when the drying steam is supplied into the pipe, the heat transfer pipe 44 uses the latent heat of the drying steam to heat the lignite in the fluidized bed 18, thereby removing moisture in the lignite in the fluidized bed 18. By removing, the lignite in the drying chambers 38a, 38b, 38c is dried. Thereafter, the drying steam used for drying is discharged outside the drying chamber 38. The drying steam used for drying may be supplied to the preheating heat transfer tube 29 as a heating medium.

  Therefore, the preheated lignite supplied to the upstream drying chamber 38a via the lignite charging port 41 flows by the fluidized steam supplied via the gas dispersion plate 36, so that the upstream drying chamber 38a. The fluidized bed 18 is formed over the downstream drying chamber 38 c and the free board portion F is formed above the fluidized bed 18. The fluidized bed 18 formed in the drying chamber 38 flows in the direction from one end side to the other end side of the drying chamber 38. The lignite supplied to the upstream drying chamber 38a is heated and dried by the heat transfer tube 44 while flowing along the flow direction. Thereby, the water | moisture content contained in brown coal turns into generated vapor | steam, and is discharged | emitted from the vapor | steam discharge port 43 with fluidized vapor | steam. The lignite from which moisture has been removed and flowed to the drying chamber 38c on the downstream side is discharged from the dry coal discharge port 42 as dry coal.

  Here, the preheating temperature of the lignite discharged from the preheating device 10 is measured by a preheating thermometer (preheating temperature measuring device) 50. The preheating thermometer 50 is provided between the preheating device 10 and the brown coal conveying device 30 and is connected to the control unit 60. The control unit 60 may be a control panel provided in the coal gasification combined power generation facility 100 or may be a control panel provided in the drying system 1 and is not limited.

  The controller 60 controls the temperature (heating temperature) of the heating medium supplied to the preheating heat transfer tube 29 based on the preheating temperature measured by the preheating thermometer 50. Specifically, the control unit 60 controls the temperature of the heating medium so that the preheating temperature measured by the preheating thermometer 50 becomes the steam saturation temperature. For this reason, the control part 60 raises the temperature of the heating medium for heating, when the preheating temperature measured by the preheating thermometer 50 has not reached the saturation temperature of steam. The controller 60 does not increase the temperature of the heating medium when the preheating temperature measured by the preheating thermometer 50 exceeds the saturation temperature of the steam.

  As described above, according to the configuration of the first embodiment, the lignite can be preheated by the preheating device 10 and the preheated lignite can be supplied to the fluidized bed drying device 11. For this reason, the fluidized steam in the fluidized-bed drying apparatus 11 becomes difficult to condense by supplying the preheated lignite to the fluidized-bed drying apparatus 11. Thereby, aggregation of lignite due to condensation of fluidized steam can be suppressed, occurrence of poor flow of lignite can be suppressed, and flow of lignite in the fluidized bed drying device 11 can be made suitable.

  Moreover, according to the structure of Example 1, the preheating apparatus 10 uses a non-condensable gas as the fluidizing gas, and heats the lignite while flowing with the fluidizing gas, thereby efficiently raising the temperature of the lignite. Moreover, generation | occurrence | production of the condensation of fluidized gas in the preheating apparatus 10 can be suppressed. Thereby, the preheating apparatus 10 can suppress the aggregation of lignite due to the condensation of the fluidized gas, can suppress the occurrence of poor flow of lignite, and can make the flow of lignite in the preheating apparatus 10 suitable. it can.

  Moreover, according to the structure of Example 1, the control part 60 can control the temperature of a heating heat medium, and can make the preheating temperature of lignite the steam saturation temperature. For this reason, since the lignite preheated to the saturation temperature of the steam is supplied to the fluidized bed drying apparatus 11, the fluidized steam is more difficult to condense.

  Moreover, according to the structure of Example 1, the fluidized bed drying apparatus 11 can dry lignite with a water content of 50% or more while flowing using fluidized steam. For this reason, the fluidized bed drying apparatus 11 can be suitably dried even for lignite with a high water content.

  Next, a drying system 200 according to the second embodiment will be described with reference to FIG. FIG. 3 is a schematic configuration diagram schematically illustrating a drying system according to the second embodiment. In the second embodiment, parts that are different from the first embodiment will be described in order to avoid duplicated descriptions, and parts that have the same configuration as the first embodiment are denoted by the same reference numerals. In the drying system 1 according to the first embodiment, the preheating device 10 is a fluidized bed preheating device that preheats by forming the fluidized bed 15 therein. However, in the drying system 200 according to the second embodiment, the preheating device 201 includes: It is a transfer type preheating device that preheats while transferring the internal lignite. Hereinafter, the drying system 200 according to the second embodiment will be described.

  As shown in FIG. 3, the drying system 200 according to the second embodiment includes a preheating device 201 and a fluidized bed drying device 11. In addition, since the fluidized bed drying apparatus 11 is the structure similar to Example 1, description is abbreviate | omitted. The preheating device 201 includes a preheating container 205 into which lignite is supplied.

  The preheating container 205 is formed in a cylindrical shape whose horizontal direction is the axial direction. The preheating container 205 is formed with a heat medium flow path 206 through which a heating heat medium flows on the outer peripheral side thereof, and the heating heat medium flows through the heat medium flow path 206 to heat the preheating container 205. ing. In the heat medium flow path 206, a heat medium inlet 210 into which the heating heat medium flows and a heat medium outlet 211 from which the heating heat medium flows out are formed. The heat medium inlet 210 is provided in the heat medium flow path 206 on the other end side (right side in the figure) of the preheating container 205, and the heat medium outlet 211 is the heat medium flow path on one end side (left side in the figure) of the preheating container 205. 206. Thereby, the heating heat medium flows in the direction toward the one end side from the other end side of the preheating container 205 in the heat medium flow path 206.

  The preheating container 205 is provided with a brown coal inlet 215, a gas outlet 216, and a lignite outlet 217. The brown coal inlet 215 is formed in the upper part of one end side of the preheating container 205. A coal supply device 111 is connected to the brown coal inlet 215, and the lignite supplied from the coal supply device 111 is supplied into the preheating container 205. The gas discharge port 216 is formed in the upper part on the other end side of the preheating container 205. From the gas discharge port 216, generated steam generated by heating lignite in the preheating container 205 is discharged. The brown coal discharge port 217 is formed in the lower part on the other end side of the preheating container 205. From the lignite discharge port 217, the lignite preheated in the preheating container 205 is discharged toward the fluidized bed drying device 11.

  A screw feeder 222 is provided inside the preheating container 205. The screw feeder 222 has a rotating shaft 231, a screw portion 232 provided on the rotating shaft 231, and a motor 233 that rotates the rotating shaft 231. The rotating shaft 231 is in the same direction as the axial direction of the preheating container 205. Then, when the rotating shaft 231 is rotated by the motor 233, the lignite is transferred from one end side to the other end side of the preheating vessel 205 while the screw portion 232 is turned. That is, the transfer direction of lignite is a direction from one end side to the other end side of the preheating container 205.

  Therefore, the lignite supplied from the coal feeder 111 is input to one end side of the preheating container 205, and the input lignite is transferred in the transfer direction by the screw feeder 222. The lignite transferred in the transfer direction is heated by the heating heat medium passing through the heat medium flow path 206 via the preheating container 205. Thereby, the heated lignite is preheated to a predetermined preheating temperature. Then, the lignite transferred in the transfer direction is input from the lignite discharge port 217 toward the drying chamber 38a on the upstream side of the fluidized bed drying apparatus 11.

  As mentioned above, according to the structure of Example 2, the preheating apparatus 201 can preheat, conveying lignite in the transfer direction. For this reason, by providing the preheating device 201 in the movement path of lignite, it is possible to perform both lignite transfer and preheating.

DESCRIPTION OF SYMBOLS 1 Drying system 10 Preheating apparatus 11 Fluidized bed drying apparatus 15 Fluidized bed of preheating chamber 18 Fluidized bed of drying chamber 21 Preheating container 22 Preheating gas dispersion plate 23 Preheating wind chamber 24 Preheating chamber 26 Brown coal inlet of preheating device 27 Brown coal discharge Outlet 28 Gas outlet 29 Heat transfer pipe 30 for preheating 30 Brown coal conveying device 35 Drying container 36 Gas dispersion plate 37 Air chamber 38 Drying chamber 41 Brown coal inlet of fluidized bed dryer 42 Dry coal outlet 43 Steam outlet 44 Heat transfer tube 50 Preheating Thermometer 60 Control unit 200 Drying system (Example 2)
201 Preheating device (Example 2)
205 Preheating container (Example 2)
206 Heating medium flow path 210 Heating medium inlet 211 Heating medium outlet 215 Brown coal charging port of preheating device (Example 2)
216 Gas outlet (Example 2)
217 Brown coal discharge port (Example 2)
222 Screw feeder 231 Rotating shaft 232 Screw part 233 Motor F Free board part

Claims (3)

A fluidized bed drying apparatus that dries the wet fuel by a heat transfer tube provided inside the fluidized bed while forming a fluidized bed inside by flowing the wet fuel supplied to the inside with fluidized steam;
A preheating device for preheating the wet fuel supplied to the fluidized bed drying device,
The preheating device is a fluidized bed preheating device that preheats the wet fuel while forming a fluidized bed inside by flowing the wet fuel supplied to the inside with a fluidized gas.
The fluidized bed preheating device has a preheating heat transfer tube as a heating unit for heating the wet fuel,
The preheating heat transfer tube is supplied with a heating heat medium used in the heat transfer tube provided in the fluidized bed drying apparatus,
The fluidized bed preheating device is supplied with air or combustion exhaust gas which is a non-condensable gas as the fluidizing gas. The preheating device has the heating unit for heating the moist fuel,
A preheating temperature measuring device for measuring a preheating temperature of the wet fuel preheated by the preheating device;
The drying apparatus according to claim 1, further comprising a control device that controls a heating temperature of the heating unit so that the preheating temperature measured by the preheating temperature measurement device becomes a saturation temperature of steam. system.   The drying system according to claim 1 or 2, wherein the wet fuel has a moisture content of 50% or more.

Images