JP2012087974A - Coal-fired power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated coal gasification combined cycle power generation system capable of reducing energy necessary for drying coal by a coal pulverizer by effectively utilizing excess nitrogen in an exhaust gas.SOLUTION: This coal-fired power generation system includes a coal gasification furnace 3 producing coal-gasification gas by gasifying coal supplied from coal supply equipment 2, a gas turbine 5 for obtaining power of a power generator by burning the coal-gasification gas, and an air separator 8 for separating oxygen and nitrogen from the exhaust gas discharged from the gas turbine 5. This system is constituted to supply carbon dioxide in the exhaust gas and oxygen of the air separator 8 to the coal gasification furnace 3 as a gasification agent, and the coal of the coal supply equipment 2 is dried by using nitrogen separated from the air separator 8.

Description

  The present invention relates to a coal-fired power generation system, and in particular, effectively uses surplus nitrogen generated in an air separation device in a coal-fired power generation system that recovers carbon dioxide, such as a coal gasification power generation system and an Oxy-fuel type power generation system. It is useful to apply to cases.

  Coal exists in a large area of the world, has a large recoverable reserve, and has a stable price, so it has a high supply stability and a low price per calorific value. An IGCC (Integrated Coal Gasfication Combined Cycle) system is known as one type of thermal power generation using coal as a fuel. In the combined coal gasification combined power generation system, the gas turbine is driven by using the coal gasification gas obtained by incomplete combustion of the coal to obtain power, and the exhaust heat of the gas turbine is recovered to generate steam, Electric power is obtained by driving the steam turbine with the generated steam (see, for example, Patent Document 1).

  One example of a combined coal gasification combined power generation system is one that collects carbon dioxide from exhaust gas discharged from a gas turbine and supplies a part thereof together with coal to a coal gasifier as a gasifying agent. Moreover, the coal gasification combined power generation system is provided with an air separation device that separates oxygen and nitrogen from air, and oxygen obtained by the air separation device is also supplied to the coal gasification furnace. Carbon dioxide has the effect of promoting the gasification of coal, so in a coal gasifier that supplies carbon dioxide, compared to gasifying coal with air, air with increased oxygen concentration, or oxygen. The purity of recovered carbon dioxide is greatly improved.

  Recently, CCS (Carbon Capture and Storage), which separates, collects and stores carbon dioxide generated from power plants, is being studied around the world as a measure against global warming. The coal gasification combined power generation system mentioned above is regarded as promising for realizing CCS. In other words, since the exhaust gas becomes high-concentration carbon dioxide, if the carbon dioxide is supplied to the coal gasifier, the carbon dioxide used in the conventional pre-combustion system (CCS system that separates carbon dioxide from the product gas in IGCC). This is because a carbon separation step becomes unnecessary and carbon dioxide emissions can be reduced. Furthermore, it is expected that the facility and operation costs will be significantly reduced by eliminating the separation step, and that high power generation efficiency of 40% or more will be maintained even after carbon dioxide recovery (for example, non-patent literature) 1).

  Thus, in the coal gasification combined power generation system, carbon dioxide recovered from the exhaust gas is effectively utilized for coal gasification, while surplus nitrogen generated in the air separation device is not effectively utilized. is the current situation. In particular, when a closed type gas turbine is employed, a large amount of nitrogen is generated. Therefore, effective utilization of excess nitrogen is an important issue.

  For example, in a coal gasification furnace, when gasification is performed by supplying oxygen without supplying carbon dioxide, in order to take measures against nitrogen oxides, in the coal gasification gas (product gas) in front of the gas turbine It is possible to supply surplus nitrogen generated in the air separator.

  However, similarly to this example, when surplus nitrogen is supplied to a coal gasifier using carbon dioxide as a gasifying agent, the concentration of carbon dioxide is relatively lowered, and the purity of recovered carbon dioxide is lowered. For this reason, it is not preferable to use surplus nitrogen for gasification in a coal gasifier.

  The coal gasification combined power generation system is provided with a pulverized coal machine that pulverizes coal and supplies it to a coal gasification furnace. Since moisture adheres to the surface of coal, the pulverized coal machine pulverizes the coal and dries the coal with high-temperature air. Since this drying requires a lot of energy, it is a factor that lowers the energy efficiency of the combined coal gasification combined power generation system.

  Such a problem is not limited to a coal gasification combined power generation system, but generally exists in a power generation system that burns finely pulverized coal. For example, the same applies to a CCS-compatible coal-fired power generation system using Oxy-fuel, which is another method of CCS. The CCS-compatible thermal power generation system using Oxy-fuel burns finely pulverized coal in a boiler, supplies a part of the carbon dioxide in the exhaust gas discharged from the boiler to the boiler, and compresses the remaining carbon dioxide. And have facilities for segregation.

  At present, in the coal-fired power generation system using Oxy-fuel, it seems that surplus nitrogen generated in the air separation device is discharged and discarded. In addition, even in an oxygen-blown coal gasification plant that is already in operation, a considerable amount of surplus nitrogen seems to have been discharged and discarded, and surplus nitrogen is not effectively utilized.

JP 2005-171148 A

“Development of oxy-fuel IGCC system with CO2 recirculation for CO2 capture”, Oki.Y., et al, Proceeding of 10th International Conference on Greenhouse Gas Control Technology, 2010

  In view of such circumstances, the present invention provides a coal-fired power generation facility that can effectively use surplus nitrogen generated in an air separation device and reduce energy required to dry coal with a pulverized coal machine. With the goal.

  A first aspect for achieving the above object is to generate power using coal supplied from a coal supply facility, to separate oxygen and nitrogen from air, and to burn coal or gasify coal. The coal thermal power generation system includes an air separation device that supplies oxygen to the power generation means, and a drying means that dries the coal of the coal supply facility using nitrogen generated in the air separation device.

  In the first aspect, surplus nitrogen generated in the air separation device is supplied to the coal supply facility, and the nitrogen is used for drying the coal. Therefore, effective use of nitrogen generated in a large amount in the air separation device can be achieved. . Moreover, since coal is dried with the excess nitrogen produced in large quantities, energy required for drying coal can be reduced, and the efficiency of the entire coal-fired power generation system can be improved.

  According to a second aspect of the present invention, in the coal-fired power generation system described in the first aspect, the coal supply facility is disposed in a coal bunker for storing coal conveyed by a conveyor, and a lower portion of the coal bunker. A pulverized coal machine to which coal is supplied via a metering coal feeder, and the drying means is configured to dry the coal with the nitrogen before the coal is supplied to the pulverized coal machine. The coal-fired power generation system is characterized by

  In this 2nd aspect, since coal is dried before pulverizing coal with a pulverized coal machine, the energy for drying of coal required with a pulverized coal machine can be reduced.

  According to a third aspect of the present invention, in the coal-fired power generation system described in the second aspect, the drying means is configured to dry the coal conveyed to the conveyor with the nitrogen. In the coal-fired power generation system.

  In the third aspect, the coal conveyed to the conveyor can be dried with nitrogen from the air separation device.

  According to a fourth aspect of the present invention, in the coal thermal power generation system described in the second or third aspect, the drying means is stored in a coal bunker chamber disposed between the conveyor and the coal bunker. The coal-fired power generation system is configured to dry the coal with the nitrogen.

  In the fourth aspect, the coal before being put into the coal bunker can be dried with excess nitrogen.

  A fifth aspect of the present invention is the coal-fired power generation system according to any one of the second to fourth aspects, wherein the drying means is supplied with coal between the coal bunker and the pulverized coal machine. The coal-fired power generation system is configured to install a fluidized bed dryer and supply the nitrogen to the fluidized bed dryer.

  In the fifth aspect, since the coal is preliminarily dried in the fluidized bed dryer before the pulverized coal machine, the energy required for drying the coal in the pulverized coal machine can be reduced, and air separation can be performed. Nitrogen from the apparatus can be used effectively.

  According to a sixth aspect of the present invention, in the coal-fired power generation system described in the fifth aspect, the coal-fired power generation system includes a heat exchanger that heats nitrogen supplied to the fluidized bed dryer. is there.

  In the sixth aspect, the higher temperature nitrogen is supplied to the fluidized bed dryer, so that the coal is further dried, and the energy required for drying the coal in the pulverized coal machine can be further reduced.

  A seventh aspect of the present invention is the coal-fired power generation system according to any one of the second to fourth aspects, wherein the drying means is supplied with coal between the coal bunker and the pulverized coal machine. The coal-fired power generation system is configured to install a rotary kiln type dryer and supply the nitrogen to the rotary kiln type dryer.

  In the seventh aspect, since the coal rolls by the rotation of the cylindrical body of the rotary kiln type dryer and the entire surface of the coal is exposed to the nitrogen atmosphere, the entire surface of the coal can be uniformly dried.

  According to an eighth aspect of the present invention, there is provided the coal-fired power generation system according to the seventh aspect, wherein the rotary kiln type dryer is an external heating type.

  In the eighth aspect, since the coal inside the rotary kiln type dryer is heated, the coal can be further dried.

  According to a ninth aspect of the present invention, in the coal-fired power generation system described in the eighth aspect, nitrogen supplied to the externally heated rotary kiln type dryer is preheated with heat generated in a residual oxygen treatment furnace of exhaust gas. It is in the coal thermal power generation system characterized by including the heating means to do.

  In the ninth aspect, the higher temperature nitrogen is supplied to the rotary kiln-type dryer, whereby the coal is further dried, and the energy required for drying the coal in the pulverized coal machine can be further reduced.

  According to a tenth aspect of the present invention, in the coal-fired power generation system according to any one of the first to ninth aspects, the power generation means gasifies coal to produce a coal gasification gas. And a gas turbine that burns the coal gasification gas to obtain power of a generator, and the carbon gas in the exhaust gas and the oxygen of the air separation device are supplied to the coal gasification furnace as a gasifying agent. A coal-fired power generation system is characterized by being configured as described above.

  In the tenth aspect, the surplus nitrogen is effectively used for drying the coal, and the surplus nitrogen is not charged into the coal gasification furnace. Therefore, the carbon dioxide concentration in the coal gasification furnace is maintained, and the carbon conversion rate and the recovered dioxide dioxide are maintained. It can avoid that carbon purity falls.

  According to an eleventh aspect of the present invention, in the coal-fired power generation system described in the tenth aspect, the power generation means obtains power of the generator by expanding the steam obtained by recovering heat of the exhaust gas. A coal-fired power generation system further comprising a steam turbine.

  In the eleventh aspect, power can be generated using the power generated by the steam turbine in addition to the power generated by the gas turbine, and more efficient power generation can be performed.

  A twelfth aspect of the present invention is the coal-fired power generation system according to any one of the first to ninth aspects, wherein the power generation means is obtained by a boiler that burns coal and heat generated in the boiler. A steam turbine that obtains power from the generator by expanding the generated steam, collects carbon dioxide contained in the exhaust gas from the boiler, supplies part of the carbon dioxide to the boiler, and stores the remaining carbon dioxide It is comprised in the coal-fired power generation system characterized by doing.

  In the twelfth aspect, in the so-called Oxy-fuel type coal-fired power generation system, the drying of coal can be promoted by various drying means using surplus nitrogen generated in the air separation device.

  ADVANTAGE OF THE INVENTION According to this invention, the coal-fired power generation system which can reduce the energy which uses effectively the surplus nitrogen which generate | occur | produces with an air separation apparatus, and dry coal with a pulverized coal machine is provided.

It is a schematic block diagram of the coal gasification combined cycle power generation equipment which is an example of the coal thermal power generation system concerning the embodiment of the present invention. It is a schematic block diagram of the coal supply equipment and drying means concerning Embodiment 1. It is a schematic block diagram of the coal supply equipment which concerns on Embodiment 2, and a drying means. It is a schematic block diagram of the coal supply equipment and drying means which concern on Embodiment 3. It is a schematic block diagram of the coal supply equipment and drying means which concern on Embodiment 3. It is a schematic block diagram of the coal supply equipment and drying means which concern on Embodiment 4. It is a schematic block diagram of the coal supply equipment and drying means which concern on Embodiment 4. It is a schematic block diagram of the coal supply equipment and drying means in the coal thermal power generation system concerning Embodiment 5.

<Embodiment 1>
FIG. 1 is a schematic configuration diagram of a coal gasification combined power generation facility which is an example of a coal gasification power generation system according to an embodiment of the present invention.

  As illustrated, the combined coal gasification combined power generation system 1 includes a coal supply facility 2 that supplies coal to a coal gasification furnace. Although the details will be described later, the coal supply facility 2 is a facility for pulverizing stored coal with a pulverized coal machine and supplying the coal to the coal gasification furnace 3.

  Coal pulverized by the coal supply facility 2 is supplied to the coal gasifier 3. The coal gasification furnace 3 is supplied with carbon dioxide from the inside of the system, that is, carbon dioxide separated from the exhaust gas that has finished work in the gas turbine 5 and heat-exchanged in the exhaust heat recovery boiler 6. Yes. The coal gasifier 3 is also supplied with oxygen separated from the raw air by the air separation device 8.

  These carbon dioxide and oxygen function as coal gasifying agents. In the coal gasification furnace 3, coal gasification gas is produced | generated when coal reacts with a gasification agent. By gasifying coal with carbon dioxide and oxygen, the carbon conversion rate is greatly improved compared to gasifying coal with air, air with increased oxygen concentration, or oxygen due to the gasification promotion effect of carbon dioxide. To do.

  The coal gasification gas contains combustible components such as carbon monoxide and hydrogen gas, and also contains water-soluble impurities, condensable impurities, particulate impurities, and gaseous impurities. The coal gasification gas generated in the coal gasification furnace 3 is dedusted by dust removing means (not shown), adjusted to a predetermined temperature by a heat exchanger (not shown), and supplied to the gas purification facility 4. The

  As the gas purification equipment 4, a dry method in which the temperature of the coal gasification gas is maintained at a temperature higher than the dew point or a device that removes impurities of the coal gasification gas by a wet method is used. The configuration is not particularly limited as long as it can remove the above-described various impurities. For example, as the gas purification facility 4, an impurity removal device such as a halide removal device, a desulfurization device, an ammonia removal device, or a mercury removal device is used. it can.

  When the coal gasification gas is sent to the gas purification facility 4, impurities are removed and purified by various impurity removal devices, and fuel gas is obtained.

  The gas turbine 5 is supplied with the fuel gas purified by the gas purification facility 4. Specifically, although not particularly illustrated, a combustor and a compressor are connected to the gas turbine 5 and fuel gas is sent to the combustor. Further, high concentration oxygen produced by the air separation device 8 is sent to the combustor, and the fuel gas is combusted. Further, the carbon dioxide in the exhaust gas heat recovered by the exhaust heat recovery boiler 6 is compressed by a compressor and put into a combustor. Combustion gas generated by combustion in the combustor is sent to the gas turbine 5, and the gas turbine 5 obtains power for driving the generator by expansion of the combustion gas.

  The exhaust gas that has finished work in the gas turbine 5 is sent to the exhaust heat recovery boiler 6. The exhaust heat recovery boiler 6 performs heat recovery of the exhaust gas and supplies steam generated by this heat to the steam turbine 7.

  The steam turbine 7 obtains power for driving the generator by expansion of the steam supplied from the exhaust heat recovery boiler 6. The above-described compressor, gas turbine 5, steam turbine 7 and generator (not shown) are connected in a coaxial state. The generator is driven by the power of the gas turbine 5 and the steam turbine 7 connected in series, and the combined power generation by the gas turbine 5 and the steam turbine 7 is performed.

  The exhaust gas heat recovered by the exhaust heat recovery boiler 6 is separated from carbon dioxide, and a part thereof is sent to the gas turbine 5 and the coal gasifier 3. The remaining carbon dioxide is transported outside and stored in the formation.

  The air separation device 8 cools the raw air with a cryogenic refrigerant and separates these gases according to the boiling points of various gases such as nitrogen, oxygen, and argon contained in the exhaust gas. Specifically, the raw material air is cooled by the air separation device 8 after moisture is removed by the adsorber. For this reason, the nitrogen (boiling point-196 ° C.) obtained from the air separation device 8 does not include moisture having different boiling points (boiling point 100 ° C.), and a large amount of dried nitrogen is obtained.

  As described above, the oxygen separated by the air separation device 8 is sent to the coal gasification furnace 3 and the gas turbine 5 (combustor). Furthermore, the nitrogen separated from the air separation device 8 is supplied to the coal supply facility 2 to effectively use the nitrogen.

  A coal supply facility for effectively using nitrogen will be described with reference to FIG. As shown in the figure, the coal supply facility 2 includes a bunker chamber 11 and a coal bunker 12 for temporarily storing the coal conveyed by the conveyor 10, a metering coal feeder 13 disposed below the coal bunker 12, It consists of a pulverized coal machine 14.

  The conveyor 10 is installed to be inclined upward in order to convey coal to the bunker chamber 11 installed at the upper side, and a cover 15 that covers the conveyor 10 is provided around the conveyor 10. Coal stored in the bunker chamber 11 is paid out to the metering coal feeder 13 via the coal bunker 12. The metering coal feeder 13 supplies a predetermined amount of coal to the pulverized coal machine 14 while measuring the coal.

  The pulverized coal machine 14 is supplied with the coal supplied from the metering coal feeder 13 and is supplied with high-temperature air for drying. The pulverized coal machine 14 crushes the coal and dries the coal with air for drying. The coal pulverized and dried by the pulverized coal machine 14 is supplied to the coal gasification furnace 3 by airflow conveyance.

  The coal supply facility 2 having such a configuration is provided with drying means for drying the coal using nitrogen separated from the air separation device 8 (see FIG. 1). Specifically, the drying means is configured by introducing nitrogen from the air separation device 8 into a space between the conveyor 10 that conveys coal and a cover 15 that covers the conveyor 10.

  As described above, since the nitrogen obtained from the air separation device 8 contains almost no moisture and is dry, the moisture attached to the coal conveyed by the conveyor 10 is likely to evaporate, and the drying of the coal can be promoted. .

  Thus, the energy required for heating the air for drying coal in the pulverized coal machine 14 can be reduced by drying the coal with nitrogen in the stage before being supplied to the pulverized coal machine 14. .

  As described above, the combined coal gasification combined cycle system 1 according to the present embodiment supplies surplus nitrogen generated in the air separation device 8 to the coal supply facility 2 and uses the nitrogen for drying the coal. Effective use of nitrogen generated in a large amount in the separation device 8 can be achieved. Moreover, since coal is dried before pulverizing coal with the pulverized coal machine 14, the energy for drying of coal required by the pulverized coal machine 14 can be reduced, and the coal gasification combined cycle power generation system 1 whole can be reduced. Efficiency can be improved.

  Moreover, since surplus nitrogen is not thrown into the coal gasification furnace 3, it can avoid that the carbon dioxide concentration in the coal gasification furnace 3 is maintained, and a carbon conversion rate and a carbon dioxide purity fall.

<Embodiment 2>
In the first embodiment, the drying unit that inputs nitrogen from the air separation device 8 into the space between the conveyor 10 and the cover 15 of the coal supply facility 2 has been described. However, the nitrogen input location is not limited thereto. . Hereinafter, various aspects of the drying means will be described.

  FIG. 3 is a schematic configuration diagram of coal supply equipment and drying means according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same thing as Embodiment 1, and the overlapping description is abbreviate | omitted.

  As shown in the figure, the drying means of the present embodiment is configured such that a part of the bunker chamber 11 is provided with an inlet 16 communicating with the outside, and nitrogen from the air separation device 8 is supplied to the inlet 16. Yes. Thus, by supplying nitrogen to the bunker chamber 11, it is possible to dry the coal before being put into the coal bunker 12. Thereby, similarly to Embodiment 1, the energy required for drying coal by the pulverized coal machine 14 can be reduced.

<Embodiment 3>
As a drying means for drying the coal before the pulverized coal machine 14, a fluidized bed dryer can be used. FIG. 4 is a schematic configuration diagram of coal supply equipment and drying means according to the third embodiment. In addition, the same code | symbol is attached | subjected to the same thing as Embodiment 1, and the overlapping description is abbreviate | omitted.

  As illustrated, the fluidized bed dryer 17 is installed between the coal bunker 12 and the pulverized coal machine 14. Coal supplied from the coal bunker 12 and measured by the metering coal feeder 13 is supplied to the fluidized bed dryer 17 in a predetermined amount.

  Further, the fluidized bed dryer 17 is configured to be supplied with nitrogen supplied from the air separation device 8 together with high-temperature air blown onto the coal from below the coal. That is, in the fluidized bed dryer 17, nitrogen from the air separation device 8 is also used for drying coal.

  As described above, since the coal is preliminarily dried in the fluidized bed dryer 17 in the previous stage of the pulverized coal machine 14, energy required for drying the coal in the pulverized coal machine 14 can be reduced, and air separation is performed. Nitrogen from the apparatus 8 can be used effectively.

  Furthermore, as shown in FIG. 5, the nitrogen supplied from the air separation device 8 to the fluidized bed dryer 17 may be heated by a heat exchanger 18. In this case, by supplying higher temperature nitrogen to the fluidized bed dryer 17, the coal is further dried, and the energy required for drying the coal by the pulverized coal machine 14 can be further reduced.

  In addition, although the heat source of the heat exchanger 18 is not particularly limited, the heat efficiency of the entire system can be improved by using the heat generated in the coal gasification combined power generation system 1.

<Embodiment 4>
As a drying means for drying the coal before the pulverized coal machine 14, a rotary kiln type dryer can be used. FIG. 6 is a schematic configuration diagram of a coal supply facility and a drying unit according to the fourth embodiment. In addition, the same code | symbol is attached | subjected to the same thing as Embodiment 1, and the overlapping description is abbreviate | omitted.

  As shown in the drawing, the rotary kiln-type dryer 19 rotates coal that is an object to be treated while rotating an inclined cylindrical body, and heats the coal at a predetermined temperature and time. The rotary kiln type dryer 19 is provided with a weighing function by installing a load cell.

  The rotary kiln type dryer 19 is installed between the coal bunker 12 and the pulverized coal machine 14. That is, the coal supplied from the coal bunker 12 is measured by the rotary kiln type dryer 19 and supplied to the pulverized coal machine 14.

  The rotary kiln-type dryer 19 is supplied with nitrogen from the air separation device 8. For this reason, in the rotary kiln type dryer 19, coal is heated and dried under a dry atmosphere.

  Thus, since the coal is preliminarily dried by the rotary kiln type dryer 19 in the previous stage of the pulverized coal machine 14, the energy required for drying the coal by the pulverized coal machine 14 can be reduced, and air separation is performed. Nitrogen from the apparatus 8 can be used effectively.

  Moreover, although the rotary kiln type dryer 19 mentioned above is what is called an external heating type rotary kiln type dryer 19 and heated coal in the dry nitrogen atmosphere, it is not necessarily required to heat. That is, coal may be thrown into the rotary kiln-type dryer 19 and exposed to the nitrogen atmosphere supplied from the air separation device 8 until it is discharged from the outlet while circulating through the rotating cylindrical body.

  In this case, the coal rolls due to the rotation of the cylindrical body of the rotary kiln-type dryer 19 and the entire surface of the coal is exposed to the nitrogen atmosphere, so that the entire surface of the coal can be uniformly dried.

  Further, as shown in FIG. 7, nitrogen supplied from the air separation device 8 to the rotary kiln type dryer 19 is generated in a residual oxygen treatment furnace (not shown) included in the exhaust gas of the gas turbine 5 (see FIG. 1). It may be heated with heat. In this case, the higher temperature nitrogen is supplied to the rotary kiln-type dryer 19, whereby the coal is further dried, and the energy required for drying the coal by the pulverized coal machine 14 can be further reduced.

  Note that the heat source of nitrogen supplied to the rotary kiln type dryer 19 is not limited to the heat of the above-described residual oxygen treatment furnace.

<Embodiment 5>
In the first to fourth embodiments, the coal gasification combined power generation system is exemplified as an example of the coal thermal power generation system. However, the present invention may be applied to a so-called Oxy-fuel type coal thermal power generation system. it can.

  FIG. 8 is a schematic configuration diagram of coal supply equipment and drying means in the coal-fired power generation system according to the fifth embodiment. In addition, the same code | symbol is attached | subjected to the same thing as Embodiment 1, and the overlapping description is abbreviate | omitted.

  The power generation means of the coal-fired power generation system according to the present embodiment includes a boiler 20 that burns coal, and a steam turbine that obtains the power of the generator by expanding the steam obtained by the heat generated in the boiler 20 (particularly not shown). )).

  Further, the air separation device 8 (not shown in particular) separates oxygen from the raw air as in the first embodiment, and supplies the oxygen to the boiler 20.

  The carbon dioxide in the exhaust gas generated in the boiler 20 is recovered, a part is supplied to the boiler 20, and the remainder is transported to the outside and stored in the formation.

  Even in the Oxy-fuel type coal-fired power generation system having such a configuration, surplus nitrogen generated in the air separation device 8 can be supplied to the coal supply facility 2 to promote drying of the coal. Specifically, the coal is dried with surplus nitrogen by applying various drying means as described in the first to fourth embodiments.

  FIG. 8 shows an example of the drying means. That is, as in the first embodiment, nitrogen from the air separation device 8 is introduced into the space between the conveyor 10 that conveys coal and the cover 15 that covers the periphery of the conveyor 10. Of course, the drying means described in the second to fourth embodiments may be used.

  Also in the coal-fired power generation system having such a configuration, the carbon dioxide emission can be suppressed and the drying of the coal in the coal supply facility 2 can be promoted by the surplus nitrogen generated in the air separation device 8, and the coal pulverizer 14 can dry the coal. The energy required for this can be reduced.

<Other embodiments>
In Embodiments 1 to 5 described above, one drying means is provided in each place of the coal supply facility 2, but may be combined. That is, you may use combining each drying means demonstrated in Embodiment 1- Embodiment 5. FIG.

  In the first to fourth embodiments, the coal gasification combined power generation system 1 is taken as an example of the coal gasification power generation system. However, the present invention is not necessarily limited to such an aspect. For example, the gas without using the steam turbine 7 is provided. The power generation may be performed only by the turbine 5. In short, the present invention is not limited to a coal gasification combined power generation system, but is applied to a power generation system that burns coal gasification gas to drive a gas turbine and uses carbon dioxide in the exhaust gas for coal gasification. Can do.

  Furthermore, the aspect which provides a drying means is not limited to the case where it demonstrates to Embodiment 1-5, Coal is dried using the nitrogen from the air separation apparatus 8 in the step before being supplied to the pulverized coal machine 14. What should I do?

  INDUSTRIAL APPLICABILITY The present invention can be used in a power generation system that generates coal gasification gas from coal, burns the coal gasification gas, drives a gas turbine, and uses carbon dioxide in the exhaust gas for gasification of coal. .

DESCRIPTION OF SYMBOLS 1 Coal gasification combined cycle power generation system 2 Coal supply equipment 3 Coal gasification furnace 4 Gas refinement equipment 5 Gas turbine 6 Waste heat recovery boiler 7 Steam turbine 8 Air separation device 10 Conveyor 11 Bunker room 12 Coal bunker 13 Weighing coal feeder 14 Fine powder Charcoal machine 15 Cover 16 Input port 17 Fluidized bed dryer 18 Heat exchanger 19 Rotary kiln type dryer

Claims (12)

Power generation means for generating electricity using coal supplied from a coal supply facility;
An air separation device for separating oxygen and nitrogen from air and supplying oxygen to power generation means for coal combustion or coal gasification;
A coal-fired power generation system, comprising: drying means for drying coal in the coal supply facility using nitrogen generated in the air separation device. In the coal thermal power generation system according to claim 1,
The coal supply facility is composed of a coal bunker that stores coal conveyed by a conveyor, and a pulverized coal machine that is supplied with coal via a metering coal feeder disposed in a lower portion of the coal bunker,
The drying means is configured to dry the coal with the nitrogen before the coal is supplied to the pulverized coal machine. In the coal thermal power generation system according to claim 2,
The said drying means is comprised so that the coal conveyed by the said conveyor may be dried with the said nitrogen. The coal thermal power generation system characterized by the above-mentioned. In the coal-fired power generation system according to claim 2 or claim 3,
The said drying means is comprised so that the coal stored in the coal bunker room arrange | positioned between the said conveyor and the said coal bunker may be dried with the said nitrogen. Coal thermal power generation system characterized by the above-mentioned. In the coal thermal power generation system according to any one of claims 2 to 4,
The drying means is configured to install a fluidized bed dryer to which coal is supplied between the coal bunker and the pulverized coal machine, and to supply the nitrogen to the fluidized bed dryer. And coal-fired power generation system. In the coal thermal power generation system according to claim 5,
A coal-fired power generation system comprising a heat exchanger for heating nitrogen supplied to the fluidized bed dryer. In the coal thermal power generation system according to any one of claims 2 to 4,
The drying means is configured to install a rotary kiln type dryer to which coal is supplied between the coal bunker and the pulverized coal machine, and to supply the nitrogen to the rotary kiln type dryer. And coal-fired power generation system. In the coal thermal power generation system according to claim 7,
The rotary kiln type dryer is an external heating type. In the coal thermal power generation system according to claim 8,
A coal-fired power generation system comprising heating means for preheating nitrogen supplied to the externally heated rotary kiln type dryer with heat generated in a residual oxygen treatment furnace of exhaust gas. In the coal-fired power generation system according to any one of claims 1 to 9,
The power generation means includes a coal gasification furnace that gasifies coal to generate coal gasification gas, and a gas turbine that obtains power of the generator by burning the coal gasification gas,
The coal-fired power generation system is configured such that carbon dioxide in the exhaust gas and oxygen in the air separation device are supplied to the coal gasifier as gasifying agents. In the coal thermal power generation system according to claim 10,
The said power generation means is further provided with the steam turbine which acquires the motive power of a generator by expanding the steam obtained by collect | recovering the heat | fever of the said waste gas, The coal thermal power generation system characterized by the above-mentioned. In the coal-fired power generation system according to any one of claims 1 to 9,
The power generation means includes a boiler that burns coal, and a steam turbine that obtains power of the generator by expanding steam obtained by heat generated in the boiler,
A coal-fired power generation system configured to collect carbon dioxide contained in exhaust gas from a boiler, supply a part of the carbon dioxide to the boiler, and store the remaining carbon dioxide.

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