JP2010241957A - Coal gasification combined power generation facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coal gasification combined power generation facility with enhanced power generation efficiency by increasing temperature of an air introduced into a gasification furnace. <P>SOLUTION: The coal gasification combined power generation facility 1 includes a gasification furnace 11 for gasification of a coal; a combustion air compressor 13 for air compression; a combustor 14 for combustion of a mixed gas of a gas produced by the gasification furnace 11 and an air compressed by the combustion air compressor 13; a gas turbine 15 driven by a combustion gas produced from the combustor 14; a power generator 16 driven by the gas turbine 15 to generate electrical power; an exhaust gas boiler 17 for generation of steam using an exhaust gas from the gas turbine 15; and a steam extraction system 20 extracting and introducing a part of an air compressed by the combustion air compressor 13 into the gasification furnace 11; wherein the exhaust gas boiler 17 has an exhaust gas heat exchanger 21 to conduct heat exchange of the air extracted from the combustion air compressor 13 by the steam extraction system 20 with the exhaust gas from the gas turbine 15. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a combined coal gasification combined power generation facility that combines a coal gasification furnace and combined cycle power generation.

  Conventionally, a coal gasification combined power generation facility (hereinafter referred to as “IGCC”) in which coal is gasified and combined with C / C (combined cycle power generation) is known (see, for example, Patent Document 1).

  The IGCC gasifies coal with abundant resources and uses this gas to drive a gas turbine to generate electricity. The exhaust gas boiler recovers the thermal energy of the exhaust gas from the gas turbine and generates steam. This is a facility for generating electricity by driving a steam turbine. Thus, generating efficiency can be improved by generating electric power using a gas turbine and a steam turbine.

JP-A-61-233084

  By the way, in the coal gasification combined power generation facility disclosed in Patent Document 1, the air for gasifying the coal is compressed into the gasification furnace by extracting the air extracted from the combustion air compressor with the extraction air compressor. be introduced. Originally, it is desirable that the air introduced into the gasification furnace has a high temperature from the viewpoint of power generation efficiency, but the compressor member has an allowable temperature, and the compressor power increases at a high temperature. Forced air to be supplied to the extraction air compressor. Therefore, the temperature of the air introduced into the gasification furnace is also lowered, and there is a disadvantage in that the power generation efficiency is lowered as a whole coal gasification combined power generation facility.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coal gasification combined power generation facility capable of increasing the temperature of air introduced into a gasification furnace and improving power generation efficiency. To do.

In order to solve the above problems, the present invention employs the following means.
The present invention includes a gasification furnace that gasifies coal, a combustion air compressor that compresses air for burning the gas generated by the gasification furnace, the gas generated by the gasification furnace, A combustor for combusting an air-fuel mixture compressed with air compressed by a combustion air compressor; a gas turbine driven by combustion gas generated in the combustor; and a generator driven by the gas turbine to generate electric power An exhaust gas boiler that generates steam using the exhaust gas from the gas turbine, and an extraction system that extracts a part of the air compressed by the combustion air compressor and introduces it into the gasification furnace, Coal gasification combined power generation in which an exhaust gas boiler has an exhaust gas heat exchanger that performs heat exchange between the air extracted from the combustion air compressor by the extraction system and the exhaust gas from the gas turbine To adopt the Bei.

  According to the present invention, an air-fuel mixture of gas generated by a gasification furnace and air compressed by a combustion air compressor is combusted in a combustor, and a gas turbine is driven by the generated combustion gas to generate a generator. Power is generated by At this time, a part of the air compressed by the combustion air compressor is extracted by the extraction system, and is heated by exhaust gas heat exchange with the exhaust gas heat exchanger provided in the exhaust gas boiler. Is used to gasify coal.

  Here, in order to gasify coal, for example, a combustion temperature of about 1800 ° C. is necessary. However, according to the present invention, the amount of heat in the exhaust gas is used to raise the temperature of the air introduced into the gasification furnace. Therefore, gas can be generated efficiently.

  Moreover, since the sensible heat can be utilized for gas generation by raising the temperature of the air introduced into the gasification furnace, the amount of air introduced into the gasification furnace can be reduced. As a result, since the air ratio in the gasification furnace can be reduced, a product gas with a high calorific value can be obtained, and gasification performance such as cold gas efficiency can be enhanced.

  As described above, according to the present invention, high gasification performance can be obtained by effectively using the amount of heat in the exhaust gas. Therefore, the power generation efficiency of the combined coal gasification combined power generation facility can be improved.

  In the above invention, the extraction system includes a cooler for cooling the air extracted from the combustion air compressor, and an extraction air compressor for compressing the air cooled by the cooler, and the exhaust gas heat exchange The heat exchanger may perform heat exchange between the air compressed by the extraction air compressor and the exhaust gas from the gas turbine.

  The power of the extraction air compressor can be reduced by cooling the air extracted from the combustion air compressor by the cooler. In addition, since the air compressed by the extraction air compressor is heat-exchanged with the exhaust gas from the gas turbine by the exhaust gas heat exchanger, the temperature of the air introduced into the gasification furnace can be raised. Can be generated.

  In the above invention, the extraction system is provided between the combustion air compressor and the cooler, and heats the air compressed by the extraction air compressor and the air extracted from the combustion compressor. It is good also as providing the extraction air heat exchanger to replace | exchange.

  By providing the extraction air heat exchanger, the temperature of the air compressed by the extraction air compressor can be raised by exchanging heat with the air extracted from the combustion compressor. As a result, the amount of heat of the air extracted from the combustion compressor can be used to raise the temperature of the air compressed by the extraction air compressor, that is, the air introduced into the gasification furnace. Coal can be gasified.

  In the above-described invention, a steam turbine driven using steam generated by the exhaust gas boiler may be provided, and the generator may be driven by the gas turbine and the steam turbine to generate power.

  By providing the steam turbine, steam can be generated using the heat quantity of the exhaust gas by the exhaust gas boiler, and power can be generated by driving the generator by the steam turbine using the steam. Thereby, since it can generate electric power using the rotational drive force of a gas turbine and a steam turbine, the electric power generation efficiency of the whole coal gasification combined cycle power generation equipment can be improved.

  In the above invention, the exhaust gas boiler has a plurality of superheaters that superheat steam, and the exhaust gas heat exchanger has a temperature between the plurality of superheaters so that steam supplied to the steam turbine has a rated temperature. It is good also as arrange | positioning.

  The exhaust gas heat exchanger is placed between a plurality of superheaters, for example, between a secondary superheater and a tertiary superheater, so that steam supplied to the steam turbine, that is, steam heated by the plurality of superheaters reaches a rated temperature. To place. With such an arrangement, the temperature of the air extracted from the combustion air compressor and introduced into the gasification furnace is raised by the exhaust gas heat exchanger, and the steam is superheated by a plurality of superheaters to form a steam turbine. The supplied steam can be heated to the rated temperature. Thereby, since a gas turbine and a steam turbine can be driven efficiently, the power generation efficiency of the whole coal gasification combined cycle power generation equipment can be improved.

  In the above invention, the rotating shaft of the gas turbine may be connected to the rotating shaft of the combustion air compressor.

  Thereby, the driving force of the gas turbine can be directly used to compress the air by the combustion air compressor, and the compression efficiency of the combustion air compressor can be improved.

  According to the present invention, there is an effect that the temperature of air introduced into the gasification furnace can be raised to improve the power generation efficiency.

1 is a schematic configuration diagram of a combined coal gasification combined cycle facility according to an embodiment of the present invention. It is the elements on larger scale of the exhaust gas boiler of FIG. It is a schematic block diagram of the conventional coal gasification combined cycle facility.

Hereinafter, an embodiment of a combined coal gasification combined cycle facility of the present invention will be described with reference to the drawings.
The combined coal gasification combined power generation facility 1 according to the present embodiment gasifies coal, drives a gas turbine using this gas, generates power, collects thermal energy of the exhaust gas of the gas turbine by an exhaust gas boiler, and generates steam. Is generated and the steam turbine is driven by this steam to generate electricity.

  As shown in FIG. 1, the coal gasification combined power generation facility 1 according to the present embodiment includes a gasification furnace 11, a gas purification device 12, a combustion air compressor 13, a combustor 14, and a gas turbine 15. A steam turbine (not shown), a generator 16, an exhaust gas boiler (HRSG) 17, a chimney 18 that exhausts exhaust gas that has passed through the exhaust gas boiler 17, and an extraction system 20 are provided as main components.

  The gasification furnace 11 is a furnace that heats, for example, fixed bed type, fluidized bed type, spouted bed type, or molten bed type coal. Coal and air are supplied into the furnace and, for example, 1800 ° C. under pressure. Is a facility that generates flammable gases such as carbon monoxide and hydrogen by heating at a high temperature.

  The gas purification device 12 is a facility that removes nitrogen oxides, sulfur oxides, trace components, and the like from the gas generated by the gasification furnace 11 and purifies the gas, and supplies the purified gas to the combustor 14. In addition, a flow rate adjustment valve 41 that adjusts the flow rate of the gas purified by the gas purification device 12 is provided between the gas purification device 12 and the combustor 14.

  The combustion air compressor 13 is a facility for compressing air taken from the outside, and supplies the compressed air to the combustor 14. That is, the combustion air compressor 13 is a facility for compressing combustion air for burning the gas purified by the gas purification device 12. The combustion air compressor 13 is configured such that the gas turbine 15 and a rotating shaft are connected to each other, and the gas turbine 15 is driven to rotate to compress air.

  The combustor 14 is a facility for burning an air-fuel mixture of gas generated by the gasification furnace 11 and purified by the gas purification device 12 and air compressed by the combustion air compressor 13, and is a high temperature generated by combustion. The combustion gas is supplied to the gas turbine 15.

  The gas turbine 15 is a facility driven by the combustion gas generated in the combustor 14, and converts the energy of the combustion gas supplied from the combustor 14 into a rotational driving force. Further, the gas turbine 15 is configured to be able to transmit the rotational driving force to the combustion air compressor 13 via the rotary shaft 19.

  The rotary shaft 19 is a facility for connecting the combustion air compressor 13, the gas turbine 15, and the generator 16, and transmits the rotational driving force from the gas turbine 15 to the combustion air compressor 13 and the generator 16. is there. Thereby, the driving force of the gas turbine 15 can be directly used to compress the air by the combustion air compressor 13.

  The generator 16 is a facility that generates power by being rotationally driven by the gas turbine 15. A rotating shaft 19 is connected to the generator 16 so that the rotational driving force of the rotating shaft 19 is transmitted. The generator 16 is connected to a rotating shaft of a steam turbine (not shown), and is driven to rotate by the steam turbine to generate power. Thereby, since the generator 16 can generate electric power using the rotational driving force from a gas turbine and a steam turbine, it can improve the electric power generation efficiency of the coal gasification combined cycle power generation facility 1 whole.

  The exhaust gas boiler 17 is a facility that generates steam using the exhaust gas from the gas turbine 15, and supplies the generated steam to the steam turbine. The exhaust gas boiler 17 is provided with an exhaust gas heat exchanger 21, and the exhaust gas heat exchanger 21 is connected to the extraction system 20.

The extraction system 20 is a system that extracts a part of the air compressed by the combustion air compressor 13 and introduces it into the gasification furnace 11.
In addition to the exhaust gas heat exchanger 21 described above, the extraction system 20 is provided with a cooler 22, an extraction air compressor 23, and an extraction air heat exchanger 24.

  Further, the extraction system 20 includes a piping 31 that connects the combustion air compressor 13 and the extraction air heat exchanger 24 in the order in which the air extracted from the combustion air compressor 13 circulates, and the extraction air heat exchanger. A pipe 32 connecting the cooler 22 and the cooler 22, a pipe 33 connecting the cooler 22 and the extracted air compressor 23, a pipe 34 connecting the extracted air compressor 23 and the extracted air heat exchanger 24, and A pipe 35 that connects the extraction air heat exchanger 24 and the exhaust gas heat exchanger 21 and a pipe 36 that connects the exhaust gas heat exchanger 21 and the gasifier 11 are provided. The pipe 36 is provided with a flow rate adjusting valve 42 that adjusts the flow rate of air introduced into the gasification furnace 11.

  The cooler 22 is provided between the combustion air compressor 13 and the extracted air compressor 23 and is a facility for cooling the air extracted from the combustion air compressor 13. By cooling the air extracted from the combustion air compressor 13 by the cooler 22, the power of the extraction air compressor 23 can be reduced.

  The extraction air compressor 23 is a facility that is rotationally driven by a motor and compresses the air extracted from the combustion air compressor 13 and cooled by the cooler 22, and supplies the compressed air to the gasification furnace 11. It is like that. That is, the extraction air compressor 23 is a facility that compresses air for generating gas by being heated together with coal in the gasification furnace 11.

  The extraction air heat exchanger 24 is provided between the combustion air compressor 13 and the cooler 22 and between the extraction air compressor 23 and the exhaust gas heat exchanger 21. Heat exchange is performed between the compressed air and the air extracted from the combustion air compressor 13.

  The extraction air heat exchanger 24 exchanges heat between the air compressed by the extraction air compressor 23 and the air extracted from the combustion air compressor 13, thereby increasing the air compressed by the extraction air compressor 23. Can be warmed. Thereby, the calorie | heat amount of the air extracted from the combustion air compressor 13 can be utilized in order to raise the temperature of the air compressed by the extraction air compressor 23, ie, the air introduced into the gasification furnace 11. Therefore, coal can be efficiently gasified. Moreover, since the temperature of the air supplied to the cooler 22 can be lowered, the load on the cooler 22 can be reduced.

The exhaust gas heat exchanger 21 performs heat exchange between the air extracted from the combustion air compressor 13 by the extraction system 20 and the exhaust gas from the gas turbine 15.
Since the air compressed by the extraction air compressor 23 is heat-exchanged with the exhaust gas from the gas turbine 15 by the exhaust gas heat exchanger 21, the temperature of the air introduced into the gasification furnace 11 can be raised. Gas can be efficiently generated in the conversion furnace 11.

Here, the arrangement of the exhaust gas heat exchanger 21 in the exhaust gas boiler 17 will be described with reference to a specific example shown in FIG.
In the specific example shown in FIG. 2, the exhaust gas boiler 17 includes a plurality of superheaters that superheat steam. The exhaust gas boiler 17 includes a primary superheater (not shown), a secondary superheater 52, a tertiary superheater 53, and a reheater 54 that reheats steam for driving a steam turbine (not shown), for example. Is provided. In the exhaust gas boiler 17 having such a configuration, the exhaust gas heat exchanger 21 is disposed between the secondary superheater 52, the tertiary superheater 53, and the reheater 54.

  Here, in the exhaust gas boiler 17, the temperature of the exhaust gas before passing through the exhaust gas heat exchanger 21 is, for example, 558 ° C., and the temperature of the exhaust gas after passing through the exhaust gas heat exchanger 21 is, for example, 545 ° C. In this case, the temperature of the air before passing through the exhaust gas heat exchanger 21 is 370 ° C., and the temperature of the air after passing through the exhaust gas heat exchanger 21 is 450 ° C. In this case, the temperature of the steam can be raised to the rated temperature of the steam turbine by a plurality of superheaters and reheaters.

  As described above, the arrangement shown in FIG. 2 can raise the temperature of the air extracted from the combustion air compressor 13 and introduced into the gasification furnace 11 by the exhaust gas heat exchanger 21. In addition, since the steam is heated by a plurality of superheaters and reheaters and the steam supplied to the steam turbine can be raised to the rated temperature, the gas turbine 15 and the steam turbine can be driven efficiently. The power generation efficiency of the coal gasification combined power generation facility 1 as a whole can be improved.

The operation of the combined coal gasification combined power generation facility 1 having the above configuration will be described with reference to FIG.
First, air whose flow rate is adjusted by the flow rate control valve 42 is introduced into the gasification furnace 11 via the pipe 36, and coal is gasified in the gasification furnace 11. Sulfur oxide and the like are removed from the generated gas by the gas purification device 12, the flow rate is adjusted by the flow rate control valve 41, and the gas is supplied to the combustor 14.

  On the other hand, the combustion air compressor 13 is rotationally driven by the rotary shaft 19 to suck in external air and raise the pressure to a predetermined pressure. The pressurized air is supplied from the combustion air compressor 13 to the combustor 14.

  In the combustor 14, an air-fuel mixture of the gas generated by the gasification furnace 11 and the air pressurized by the combustion air compressor 13 is burned, and high-temperature combustion gas is generated. The generated combustion gas is supplied from the combustor 14 to the gas turbine 15.

  In the gas turbine 15, thermal energy or the like that the combustion gas has is converted into a rotational driving force. The rotational driving force is transmitted from the gas turbine 15 to the rotating shaft 19. Thereafter, the combustion gas is supplied from the gas turbine 15 to the exhaust gas boiler 17 as exhaust gas.

  The rotating shaft 19 transmits a rotational driving force to the combustion air compressor 13 and the generator 16, and rotationally drives the combustion air compressor 13 and the generator 16. Thereby, the combustion air compressor 13 compresses external air, and the generator 16 generates power.

  In the exhaust gas boiler 17, steam is generated using the exhaust gas from the gas turbine 15, and the steam is supplied to the steam turbine. In a steam turbine, heat energy or the like of steam is converted into a rotational driving force. This rotational driving force is transmitted to the generator 16 and used to generate power.

  Here, a part of the compressed air is extracted from the combustion air compressor 13 by the extraction system 20, and is heated by exchanging heat with the exhaust gas by the exhaust gas heat exchanger 21 provided in the exhaust gas boiler 17. Later, it is introduced into the gasifier 11 and used to gasify coal.

Specifically, the air extracted from the combustion air compressor 13 is supplied to the extraction air heat exchanger 24 through the pipe 31. Here, the temperature of the air extracted from the combustion air compressor 13 is 450 ° C., for example.
The air supplied to the extraction air heat exchanger 24 is supplied to the cooler 22 through the pipe 32 and is cooled to, for example, 50 ° C. by the cooler 22.

The air supplied to the cooler 22 is supplied to the extraction air compressor 23 through the pipe 33 and is pressurized by the extraction air compressor 23.
The air boosted by the extraction air compressor 23 is supplied again to the extraction air heat exchanger 24 through the pipe 34, and heat exchange with the air extracted from the combustion air compressor 13 is performed. The temperature is raised to.

The air heated by the extraction air heat exchanger 24 is supplied to the exhaust gas heat exchanger 21 provided in the exhaust gas boiler 17 through the pipe 35.
The air supplied to the exhaust gas heat exchanger 21 is subjected to heat exchange with the exhaust gas from the gas turbine 15 by the exhaust gas heat exchanger 21, and is heated to 450 ° C., for example.
The air heated by the exhaust gas heat exchanger 21 is adjusted in flow rate by the flow rate control valve 42 through the pipe 36 and introduced into the gasification furnace 11 to be used for generating gas.

Here, as a comparative example, the operation of the conventional coal gasification combined cycle facility 100 will be described with reference to FIG.
The gas generated by the gasification furnace 111 is supplied to the combustor 114 via the gas purification device 112 and the flow rate control valve 141. In the combustor 114, an air-fuel mixture of the gas generated by the gasification furnace 111 and the air pressurized by the combustion air compressor 113 is burned, and the gas turbine 115 is driven by the generated combustion gas to generate power. Electric power is generated by the machine 116.

On the other hand, the air extracted from the combustion air compressor 113 is supplied to the extraction air compressor 123 through the extraction air heat exchanger 124 and the cooler 122 to be pressurized.
The air pressurized by the extraction air compressor 123 is supplied to the extraction air heat exchanger 124 again, heat exchange with the air extracted from the combustion air compressor 113 is performed, and the temperature is increased to 370 ° C., for example. .
The air heated by the extraction air heat exchanger 124 is introduced into the gasification furnace 111 as it is and used to generate gas.

  As described above, according to the conventional coal gasification combined power generation facility 100, the air introduced into the gasification furnace 111 is only heated by the extraction air heat exchanger 124. The air introduced into the gasification furnace 111 cannot be heated appropriately. As a result, coal cannot be efficiently gasified, and the power generation efficiency of the coal gasification combined power generation facility 100 as a whole is reduced.

  On the other hand, according to the coal gasification combined power generation facility 1 according to the present embodiment, a part of the air compressed by the combustion air compressor 13 is extracted by the extraction system 20 and provided in the exhaust gas boiler 17. The exhaust gas heat exchanger 21 exchanges heat with the exhaust gas to raise the temperature, and is then introduced into the gasification furnace 11 to be used for gasifying coal.

  In order to gasify coal, for example, a combustion temperature of about 1800 ° C. is required. According to the combined coal gasification combined power generation facility 1 according to the present embodiment, the gasification furnace 11 uses heat quantity in the exhaust gas. Since the temperature of the air introduced into can be raised, gas can be generated efficiently.

  Moreover, since the sensible heat can be utilized for gas generation by raising the temperature of the air introduced into the gasification furnace 11, the amount of air introduced into the gasification furnace 11 can be reduced. As a result, since the air ratio in the gasification furnace 11 can be reduced, a product gas with a high calorific value can be obtained, and gasification performance such as cold gas efficiency can be enhanced.

  As described above, according to the coal gasification combined power generation facility 1 according to the present embodiment, high gasification performance can be obtained by effectively using the amount of heat in the exhaust gas. It is possible to improve the power generation efficiency.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
For example, in the specific example of FIG. 2, the arrangement of the exhaust gas heat exchanger 21 is illustrated, but an arrangement different depending on the temperature distribution in the exhaust gas boiler 17 may be used. That is, it is only necessary that each superheater and reheater can superheat the steam supplied to the steam turbine at the rated temperature, and the present invention is not limited to this arrangement.

Moreover, although it demonstrated as the gas turbine 15 and the steam turbine being connected to the generator 16, it is good also as providing a generator in each of the gas turbine 15 and a steam turbine.
Further, although the extraction air compressor 23 has been described as being driven by a motor, it may be connected to the rotary shaft 19 and driven by the gas turbine 15.

DESCRIPTION OF SYMBOLS 1 Coal gasification combined cycle power generation facility 11 Gasification furnace 12 Gas refiner 13 Combustion air compressor 14 Combustor 15 Gas turbine 16 Generator 17 Exhaust gas boiler 19 Rotary shaft 20 Extraction system 21 Exhaust gas heat exchanger 22 Cooler 23 Extraction air Compressor 24 Extraction air heat exchanger 52 Secondary superheater 53 Tertiary superheater 54 Reheater

Claims (6)

A gasification furnace for gasifying coal;
A combustion air compressor for compressing air for burning the gas generated by the gasification furnace;
A combustor that burns an air-fuel mixture of gas generated by the gasification furnace and air compressed by the combustion air compressor;
A gas turbine driven by combustion gas generated in the combustor;
A generator driven by the gas turbine to generate power;
An exhaust gas boiler for generating steam using the exhaust gas from the gas turbine;
An extraction system for extracting a part of the air compressed by the combustion air compressor and introducing it into the gasification furnace;
The exhaust gas boiler is
A coal gasification combined power generation facility having an exhaust gas heat exchanger that performs heat exchange between the air extracted from the combustion air compressor by the extraction system and the exhaust gas from the gas turbine. The extraction system is
A cooler for cooling the air extracted from the combustion air compressor;
A bleed air compressor that compresses the air cooled by the cooler;
The exhaust gas heat exchanger is
The coal gasification combined cycle facility according to claim 1, wherein heat exchange is performed between the air compressed by the extraction air compressor and the exhaust gas from the gas turbine. The extraction system is
A bleed air heat exchanger is provided between the combustion air compressor and the cooler, and exchanges heat between the air compressed by the bleed air compressor and the air extracted from the combustion compressor. The coal gasification combined cycle power generation facility according to claim 2. Comprising a steam turbine driven using steam generated by the exhaust gas boiler;
The coal gasification combined power generation facility according to any one of claims 1 to 3, wherein the power generator is driven by the gas turbine and the steam turbine to generate power. The exhaust gas boiler has a plurality of superheaters that superheat steam,
The coal gasification combined power generation facility according to claim 4, wherein the exhaust gas heat exchanger is disposed between the plurality of superheaters so that steam supplied to the steam turbine has a rated temperature. The coal gasification combined cycle facility according to any one of claims 1 to 5, wherein a rotation shaft of the gas turbine is connected to a rotation shaft of the combustion air compressor.

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