JP2012241120A - Gasification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasification system capable of drying brown coal in a good efficiency in a fuel-compositing time, while effectively utilizing nitrogen.SOLUTION: This gasification system including a fluidized bed drying device 12, an air separator 142, a coal gasification furnace 14, a power generation facility 22 and a fuel-compositing device 21 is provided in which fuel gas (gasified gas) is supplied to the power generation facility 22 in a power generation operation time by the power generation facility 22, vapor is supplied as fluidizing gas to the fluidized bed drying device 12 while nitrogen is not supplied as the fluidizing gas from the air separator 142, a high temperature fluid flows inside a heat transfer tube 38, the fuel gas is supplied to the fuel-compositing device 21 in the fuel-compositing time by the fuel-compositing device 21, the vapor is supplied as the fluidizing gas to the fluidized bed drying device 12 and also the nitrogen is supplied from the air separator 142 as the fluidizing gas, and a low temperature fluid at a low temperature as compared with that of the high temperature fluid, flows inside the heat transfer tube 38.

Description

  The present invention relates to a gasification system in which wet fuel such as lignite is dried to obtain dry fuel, and the dry fuel is gasified to produce fuel gas.

  Conventionally, as such a gasification system, coal is pulverized and dried to make a fine powder fuel, the fine powder fuel is supplied to a gasification furnace for gasification, and the coal gas is supplied to a gas turbine to generate power. There is known a coal-fired combined power generation facility in which exhaust gas is introduced into an exhaust heat recovery boiler to generate steam, and the generated steam is supplied to a steam turbine to generate power (see, for example, Patent Document 1).

JP 7-279621 A

  By the way, in a gasification system such as a conventional coal-fired combined power generation facility, when power generation by a gas turbine is not performed, methanol, dimethyl ether, etc. are used from coal gas gasified in the gasification furnace in order to effectively use the gasification furnace. A fuel synthesizer that synthesizes liquid fuel is also provided. When fuel synthesis is performed using a fuel synthesizing apparatus, the amount of oxygen separated in the air separation apparatus is supplied to the gasifier. For this reason, the nitrogen separated in the air separation device is left, and it is difficult to effectively use the nitrogen.

  Therefore, an object of the present invention is to provide a gasification system capable of efficiently drying wet fuel while effectively utilizing nitrogen during fuel synthesis.

  A gasification system according to the present invention includes a fluidized bed drying apparatus that uses wet fuel flowing by a fluidizing gas as a dry fuel by heating it with a heat transfer tube provided therein, and air that can separate air into nitrogen and oxygen. Power generation is possible by burning the gasification gas gasified in the gasification furnace and the gasification furnace that gasifies the dry fuel into gasification gas using oxygen supplied from the separation device and air separation device And a fuel synthesizing device capable of synthesizing liquid fuel using gasified gas gasified in a gasification furnace. During power generation operation by the power generating device, the power generating device includes gasified gas. In the fluidized bed drying apparatus, steam is supplied as fluidizing gas, while nitrogen is not supplied from the air separation apparatus as fluidizing gas, and a high-temperature fluid circulates inside the heat transfer tube, Fuel synthesis equipment At the time of synthesis, gasification gas is supplied to the fuel synthesizing device, steam is supplied as fluidizing gas to the fluidized bed drying device, and nitrogen is supplied as fluidizing gas from the air separation device, and the heat transfer tube A low-temperature fluid having a temperature lower than that of the high-temperature fluid circulates in the interior of the.

  According to this configuration, when liquid fuel is synthesized by the fuel synthesizing apparatus, the amount of oxygen separated by the air separation apparatus increases, and the separated excess nitrogen is supplied to the fluidized bed drying apparatus as fluidized gas. can do. For this reason, surplus nitrogen at the time of fuel synthesis can be effectively utilized. At this time, since nitrogen is a non-condensable gas, when nitrogen is used as the fluidizing gas, the wet fuel can be dried at a lower temperature than when vapor, which is a condensable gas, is used as the fluidizing gas. . Thereby, the fluid supplied to a heat exchanger tube can be made into a low-temperature fluid, and the drying efficiency of wet fuel can be achieved. Note that the low-temperature fluid has a lower temperature than the high-temperature fluid flowing through the heat transfer tube when fluidizing with steam during the power generation operation of the gasifier.

  In this case, the apparatus further includes an exhaust heat recovery device that recovers exhaust heat of the gasified gas combusted in the power generation device, and the steam supplied as the fluidizing gas is steam generated by the exhaust heat recovered by the exhaust heat recovery device. Preferably there is.

  According to this configuration, steam generated by exhaust heat of the gasification gas can be used, so that the wet fuel can be dried more efficiently.

  In this case, it is preferable to further include a gas purification device that removes impurities of the gasification gas gasified in the gasification furnace, and the low-temperature fluid is a heat medium obtained from the gas purification device.

  According to this configuration, since the heat medium obtained from the gas purifier can be used, the wet fuel can be dried more efficiently.

  According to the gasification system of the present invention, surplus nitrogen can be supplied as a fluidizing gas to the fluidized bed drying apparatus at the time of fuel synthesis, so that nitrogen can be effectively utilized, and the heat transfer tube Since the fluid supplied to the fuel can be a low-temperature fluid, the efficiency of drying the wet fuel can be improved.

FIG. 1 is a schematic configuration diagram of the combined coal gasification combined power generation facility according to the present embodiment.

  Hereinafter, a gasification 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 the combined coal gasification combined power generation facility according to the present embodiment. The gasification system of this embodiment is a so-called coal gasification combined cycle facility (IGCC: Integrated Coal Gasification Combined Cycle) 10. The combined coal gasification combined power generation facility 10 employs an air combustion system in which coal is generated in a gasification furnace using air as an oxidant, and the gas turbine facility 17 uses the coal gas purified by the gas purification device 16 as a gasification gas. To generate electricity. That is, the coal gasification combined power generation facility 10 of the present embodiment is an air combustion type (air blowing) power generation facility. In this case, lignite is used as a wet raw material supplied to the gasifier.

  In this example, lignite was applied as a wet raw material, but low-grade coal including subbituminous 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 raw material 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 this embodiment, as shown in FIG. 1, 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 and a generator 19, and a power generation facility (power generation device) 22, a heat recovery steam generator (HRSG) 20, a fuel synthesizing device 21, and the like It has the control apparatus 23 which controls.

  The coal feeder 11 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.

  The fluidized bed drying device 12 heats and drys the lignite charged by the coal supply device 11 while fluidizing with the fluidizing gas. The fluidized bed drying device 12 includes a drying furnace 30 in which lignite is supplied and a gas dispersion plate 31 provided in the drying furnace 30. The drying furnace 30 is formed in a rectangular box shape. The gas distribution plate 31 divides the space inside the drying furnace 30 into a chamber chamber 35 located on the lower side in the vertical direction (lower side in the drawing) and a drying chamber 36 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 31, and a fluidizing gas such as steam or nitrogen is introduced into the chamber chamber 35. Thereby, the lignite supplied to the drying furnace 30 flows by the fluidizing gas, thereby forming the fluidized bed 25 in the drying furnace 30. The fluidized bed drying device 12 has a heat transfer tube 38 provided in the fluidized bed 25. The drying steam (high-temperature fluid) flows into the heat transfer tube 38 through the fluid inflow line 39. The fluid inflow line 39 is provided with a first heat transfer tube open / close valve 40. When the heat transfer tube first open / close valve 40 is opened and drying steam flows in, the heat transfer tube 38 The lignite in the drying chamber 36 is dried using latent heat.

  The fluidized bed drying apparatus 12 is connected to a cooler 131 that cools dried lignite (dry coal) taken out from the lower portion, and the dried and cooled dried coal is a dried coal bunker connected to the cooler 131. 132 is stored. Further, the fluidized bed drying apparatus 12 includes a dry coal cyclone 133 that separates dry coal particles from exhaust gas discharged from above and a dry coal electrostatic precipitator 134 in order, and the dry coal particles separated from the exhaust gas. Is stored in the dry charcoal bunker 132. The exhaust gas from which the dry coal is separated by the dry coal electrostatic precipitator 134 is subjected to latent heat recovery by power generation using a low-pressure turbine.

  The pulverized coal machine 13 produces pulverized coal by pulverizing lignite (dried coal) dried by the fluidized bed dryer 12 into fine particles. That is, when the dry coal stored in the dry coal bunker 132 is dropped by the coal supply unit 136, the pulverized coal machine 13 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 13 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 gasification furnace 14 is supplied with the pulverized coal treated by the pulverized coal machine 13 and the char (unburned coal) recovered by the char recovery device 15.

  The coal gasification furnace 14 is connected to a compressed air supply line 141 from a gas turbine facility 17 (compressor 161), and can supply compressed air compressed by the gas turbine facility 17. 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 14, 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 gasification furnace 14, and the char return line 146 from the char recovery device 15 is connected to the second nitrogen supply line 145. In addition, the third nitrogen supply line 150 is connected to a steam discharge line 175, which will be described later, and a fluidizing first on-off valve 80 is interposed in the third nitrogen supply line 150. 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 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. Thereby, in the coal gasification furnace 14, fuel gas (generated gas, coal gas, gasification gas) containing carbon dioxide as a main component is generated, and a gasification reaction takes place using this fuel gas as a gasifying agent. The coal gasification furnace 14 is provided with a foreign matter removing device 148 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 149 that supplies a combustible gas toward the char recovery device 15, and can discharge combustible gas containing char. In this case, a gas cooler is provided in the gas generation line 149 so that the fuel gas is cooled to a predetermined temperature and then supplied to the char recovery device 15.

  The char recovery device 15 includes a dust collector 151 and a supply hopper 152. In this case, the dust collector 151 is configured by one or a plurality of bag filters or cyclones, and can separate char contained in the fuel gas (gasification gas) generated in the coal gasification furnace 14. The fuel gas from which the char has been separated is sent to the gas purification device 16 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 16 performs gas purification by removing impurities such as sulfur compounds and nitrogen compounds from the fuel gas from which the char has been separated by the char recovery device 15. The gas purification apparatus 16 includes an absorption tower 41 and a regeneration tower 42. The absorption tower 41 contacts the fuel gas and the impurity absorbing liquid to remove impurities in the fuel gas. The impurities in the impurity absorbing liquid that has absorbed the impurities in the absorption tower 41 are removed and regenerated. At this time, a low-temperature fluid (heat medium) such as steam or hot water extracted from the regeneration tower 42 can be supplied into the heat transfer chamber 38 of the fluidized bed drying device 12 via the extraction line 155. . This low-temperature fluid has a lower temperature than the drying steam supplied through the fluid inflow line 39. That is, the extraction line 155 is connected to the fluid inflow line 39, and the extraction line 155 is provided with a second heat transfer tube opening / closing valve 156.

The gas purifier 16 purifies the fuel gas and supplies the purified fuel gas to the gas turbine equipment 17 and the fuel synthesizer 21. Here, the gas purification device 16 appropriately supplies fuel gas to the gas turbine facility 17 and the fuel synthesizing device 21 in accordance with the operation status of power generation by the power generation facility 22. That is, when the power demand is high, the gas purifier 16 supplies the purified fuel gas to the power generation facility 22, while when the power demand is low, the gas purifier 16 supplies the purified fuel gas to the fuel synthesizer. Supply toward 21. In this gas purification device 16, since the sulfur gas (H ₂ S) is still contained in the fuel gas from which the char has been separated, the sulfur content is finally removed by removing it with the amine absorbent. Collect as gypsum and use it effectively.

  The fuel synthesizing device 21 synthesizes a liquid fuel such as methyl alcohol or ethyl alcohol using the fuel gas supplied from the gas purification device 16. Although details will be described later, when fuel synthesis is performed in the fuel synthesizing device 21, the proportion of oxygen supplied from the air separation device 142 to the coal gasification furnace 14 is larger than when fuel synthesis is not performed. . For this reason, when fuel synthesis is performed, the nitrogen separated by the air separation device 142 remains.

  The gas turbine equipment 17 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 16, and a combustion gas supply line 167 connected to the turbine 163. Further, the gas turbine equipment 17 is provided with a compressed air supply line 141 extending from the compressor 161 to the coal gasification furnace 14, 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 purification device 16 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 19 can be driven.

  The steam turbine facility 18 has a turbine 169 connected to a rotating shaft 164 in the gas turbine facility 17, and the generator 19 is connected to a base end portion of the rotating shaft 164. The exhaust heat recovery boiler 20 is provided in the exhaust gas line 170 from the gas turbine equipment 17 (the turbine 163), and generates steam by performing heat exchange between air and high-temperature exhaust gas. Therefore, the exhaust heat recovery boiler 20 is provided with a steam supply line 171 and a steam recovery line 172 between the turbine 169 of the steam turbine equipment 18, and a condenser 173 is provided in the steam recovery line 172. Yes. Therefore, in the steam turbine facility 18, the turbine 169 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 164.

  The exhaust heat recovery boiler 20 is connected to a steam discharge line 175 for discharging steam heated by the exhaust heat, and the steam discharge line 175 is connected to the chamber chamber 35 of the fluidized bed drying device 12. . The fluid discharge second on-off valve 176 is interposed in the steam discharge line 175, and the third nitrogen supply line 150 is connected to the steam discharge line 175. 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 174, and the purified exhaust gas is discharged from the chimney 178 to the atmosphere.

  The control device 25 includes a coal supply device 11, a fluidized bed drying device 12, a pulverized coal machine 13, a coal gasifier 14, a char recovery device 15, a gas purification device 16, a power generation facility 22, an exhaust heat recovery boiler 20, and a fuel synthesis device. 21 is controlled. The control device 25 is connected to the heat transfer tube first on-off valve 40, the heat transfer tube second on-off valve 156, the fluidizing first on-off valve 80, and the fluidizing second on-off valve 176. The on / off valves 40, 80, 156, and 176 are controlled to open and close. When the power generation facility 22 performs a power generation operation, the control device 25 closes the heat transfer tube second on-off valve 156 and the fluidization first on-off valve 80, while the heat transfer tube first on-off valve 40 and the flow. The second open / close valve 176 is opened. On the other hand, when the power generation operation is not performed by the power generation facility 22 and the fuel synthesis is performed by the fuel synthesizing device 21, the control device 25 closes the first heat transfer tube on-off valve 40 and the fluidization second on-off valve 176. On the other hand, the second open / close valve 156 for heat transfer tubes and the first open / close valve 80 for fluidization are opened.

  Here, the operation of the coal gasification combined power generation facility 10 during power generation operation by the power generation facility 22 and the operation of the coal gasification combined power generation facility 10 during fuel synthesis by the fuel synthesizing device 21 will be described. First, the operation of the coal gasification combined power generation facility 10 during power generation operation by the power generation facility 22 will be described.

  In the coal gasification combined power generation facility 10 of the present embodiment, when the power generation operation is performed by the power generation facility 22, the lignite stored in the raw coal bunker 121 is dropped into the crusher 123 by the coal feeder 122. Here, it is crushed into a predetermined size. The crushed lignite is heated and dried by the fluidized bed drying device 12. At this time, the control device 25 closes the second on-off valve for heat transfer tube 156 and the first on-off valve for fluidization 80, while the first on-off valve for heat transfer tube 40 and the second on-off valve for fluidization 176 are closed. The valve is open. Therefore, the fluidized gas supplied to the fluidized bed drying device 12 is steam supplied from the exhaust heat recovery boiler 20 through the steam discharge line 175 and supplied to the heat transfer tube 38 of the fluidized bed drying device 12. The fluid to be supplied is drying vapor supplied through the fluid inflow line 39.

  The dried lignite is cooled by the cooler 131 and stored in the dry coal bunker 132. The exhaust gas discharged from the upper part of the fluidized bed drying apparatus 1 is separated into dry coal particles by the dry coal cyclone 133 and the dry coal electrostatic precipitator 134. The 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 input to the pulverized coal machine 13 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 gasifier 14 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 15 described later is supplied to the coal gasifier 14 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 17 described later is boosted by a booster 168 and then supplied to the coal gasifier 14 together with oxygen supplied from the air separator 142 through a compressed air supply line 141.

  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 fuel gas (coal gas) mainly composed of carbon dioxide. can do. The fuel gas is discharged from the coal gasifier 14 through the gas generation line 149 and sent to the char recovery device 15.

  In the char recovery device 15, the fuel gas is first supplied to the dust collector 151, and the dust collector 151 separates the char contained in the fuel gas. The fuel gas from which the char has been separated is sent to the gas purification device 16 through the gas discharge line 153. On the other hand, the fine char separated from the fuel gas is deposited on the hopper 152, returned to the coal gasifier 14 through the char return line 146, and recycled.

  The fuel gas from which the char has been separated by the char recovery device 15 is purified by the gas purification device 16 by removing impurities such as sulfur compounds and nitrogen compounds. The fuel gas purified by the gas purification device 16 is supplied toward the gas turbine facility 17, but is not supplied toward the fuel synthesis device 21. In the gas turbine equipment 17, 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 purification device 16. Combustion gas is generated by mixing with fuel gas and burning, and the turbine 163 is driven by this combustion gas, so that the generator 19 can be driven via the rotating shaft 164 to generate power.

  The exhaust gas discharged from the turbine 163 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 turbine 169 is driven by the steam supplied from the exhaust heat recovery boiler 20, whereby the generator 19 can be driven via the rotating shaft 164 to generate power. Further, the exhaust heat recovery boiler 20 supplies the generated steam as fluidized gas to the chamber chamber 35 of the fluidized bed drying device 12 through the steam discharge line 175.

  Thereafter, in the gas purification device 174, 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 178 to the atmosphere.

  Next, the operation of the coal gasification combined power generation facility 10 at the time of fuel synthesis by the fuel synthesizing device 21 will be described. Only different parts will be described in order to avoid duplicate descriptions. In the coal gasification combined power generation facility 10 of the present embodiment, when fuel synthesis is performed by the fuel synthesizing device 21, the lignite supplied from the coal supply device 11 to the fluidized bed drying device 12 is heated and dried by the fluidized bed drying device 12. The At this time, the control device 23 closes the first on-off valve 40 for heat transfer tubes and the second on-off valve 176 for fluidization, while turning the second on-off valve 156 for heat transfer tubes and the first on-off valve 80 for fluidization. The valve is open. For this reason, the fluidizing gas supplied to the fluidized bed drying device 12 is nitrogen supplied from the air separation device 142 through the third nitrogen supply line 150, and is supplied to the heat transfer tube 38 of the fluidized bed drying device 12. The supplied fluid is a low-temperature fluid such as steam or hot water supplied from the regeneration tower 42 of the gas purifier 16 through the extraction line 155.

  The dried lignite passes through devices such as a cooler 131 and a dry coal bunker 132 and is supplied to the coal gasifier 14. At this time, the ratio of oxygen supplied to the coal gasification furnace 14 of the air separation device 142 increases as compared with the case where the power generation facility 22 performs a power generation operation. For this reason, although the nitrogen separated by the air separation device 142 is surplus, as described above, surplus nitrogen is supplied to the chamber chamber 35 of the fluidized bed drying device 12 through the third nitrogen supply line 150.

  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 fuel gas (coal gas) mainly composed of carbon dioxide. can do. The produced fuel gas passes through the char recovery device 15 and is purified by the gas purification device 16 by removing impurities such as sulfur compounds and nitrogen compounds.

  The fuel gas purified by the gas purification device 16 is supplied toward the fuel synthesis device 21, but is not supplied toward the gas turbine equipment 17. The fuel synthesizing device 21 can synthesize liquid fuel by supplying the fuel gas.

  As described above, according to the configuration of the present embodiment, when liquid fuel is synthesized by the fuel synthesizing device 21, the amount of oxygen separated by the air separating device 142 increases, and the excess nitrogen separated is The fluidized gas can be supplied to the fluidized bed dryer 12. For this reason, surplus nitrogen at the time of fuel synthesis can be effectively utilized. At this time, since nitrogen is a non-condensable gas, when nitrogen is used as a fluidizing gas, lignite can be dried at a lower temperature than when steam, which is a condensable gas, is used as a fluidizing gas. Thereby, the fluid supplied to the heat exchanger tube 38 can be made into a low-temperature fluid, and the efficiency of drying of lignite can be achieved.

  Moreover, according to the structure of a present Example, since the vapor | steam which generate | occur | produces with the exhaust heat collect | recovered by the exhaust heat recovery boiler 20 can be utilized as a fluidization gas of the fluidized bed drying apparatus 12, lignite is made more efficient. Can be dried. In this embodiment, the steam that is the high-temperature fluid supplied to the fluidized bed drying device 12 is obtained from the exhaust heat recovery boiler 20, but this is not the only configuration, and in other parts of the coal gasification combined power generation facility 10 You may bleed.

  Moreover, according to the structure of a present Example, since the heat medium obtained from the gas purification apparatus 16 can be utilized as a low-temperature fluid of the heat exchanger tube 38, lignite can be dried more efficiently. In the present embodiment, the low-temperature fluid is steam or hot water extracted from the regeneration tower 42 of the gas purification device 16, but is not limited to this configuration, and is extracted in other parts of the coal gasification combined power generation facility 10. May be.

DESCRIPTION OF SYMBOLS 10 Coal gasification combined cycle power generation equipment 11 Coal feeder 12 Fluidized bed drying device 13 Pulverized coal machine 14 Coal gasifier 15 Char recovery device 16 Gas purification device 17 Gas turbine equipment 18 Steam turbine equipment 19 Generator 20 Exhaust heat recovery boiler 21 Fuel synthesizing device 22 Power generation facility 23 Control device 35 Chamber chamber 38 Heat transfer tube 39 Fluid inflow line 40 First open / close valve for heat transfer tube 41 Absorption tower 42 Regeneration tower 80 First open / close valve for fluidization 142 Air separation device 150 Third nitrogen supply Line 155 Extraction line 156 Second on-off valve for heat transfer tube 175 Steam discharge line 176 Second on-off valve for fluidization

Claims (3)

A fluidized bed drying apparatus that uses wet fuel flowing by fluidizing gas as a dry fuel by heating with a heat transfer tube provided inside;
An air separation device capable of separating air into nitrogen and oxygen;
A gasification furnace using the oxygen supplied from the air separation device to gasify the dry fuel into a gasification gas;
A power generator capable of generating power by burning the gasified gas gasified in the gasifier;
A fuel synthesis device capable of synthesizing liquid fuel using the gasification gas gasified in the gasification furnace,
During the power generation operation by the power generation device, the gasification gas is supplied to the power generation device, and steam is supplied to the fluidized bed drying device as the fluidization gas, while the fluidization gas is the above-mentioned The nitrogen is not supplied from the air separation device, a high-temperature fluid circulates inside the heat transfer tube,
At the time of fuel synthesis by the fuel synthesizing apparatus, the gasification gas is supplied to the fuel synthesizing apparatus, steam is supplied to the fluidized bed drying apparatus as the fluidizing gas, and the fluidizing gas is used as the fluidizing gas. The gasification system, wherein the nitrogen is supplied from the air separation device, and a low-temperature fluid having a temperature lower than that of the high-temperature fluid flows through the heat transfer tube. An exhaust heat recovery device for recovering exhaust heat of the gasification gas combusted in the power generation device;
The gasification system according to claim 1, wherein the steam supplied as the fluidizing gas is steam generated by exhaust heat recovered by the exhaust heat recovery device. A gas purification device for removing impurities of the gasification gas gasified in the gasification furnace;
The gasification system according to claim 1, wherein the low-temperature fluid is a heat medium obtained from the gas purification device.

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