KR20170136141A - Combined cycle power generation system - Google Patents

Abstract

A combined power generation system is disclosed. The combined power generation system according to the present invention is configured to supply syngas separated from an acid gas eliminator of a gasification portion to an anode of a fuel cell through a reformer and to supply oxygen generated from a gas separator of the gasification portion to a cathode of the fuel cell. In addition, since syngas of an unreacted anode and oxygen of the cathode are supplied to a gasifier of the gasification portion and then used, the present invention may reduce production cost.

Description

{COMBINED CYCLE POWER GENERATION SYSTEM}

The present invention relates to a combined power generation system for supplying synthesis gas (Syngas) generated by a gasification unit to fuel of a fuel cell unit and using uncombusted synthesis gas and oxygen discharged from the fuel cell unit as fuel for a gasifier of the gasification unit will be.

Combined Cycle Power Generation is the process of gasification of gas, liquid, fossil, or organic raw materials to produce Syngas, and the gas turbine is rotated by the combustion gas generated during the combustion of syngas It is a technology that generates steam by using exhaust gas discharged from a gas turbine, and then generates steam by rotating the steam turbine by the generated steam. Combined power generation has two advantages: it has excellent thermal efficiency and low environmental pollution.

A fuel cell is a technology for continuously supplying fuel and oxygen containing hydrogen, and generating electrical energy by electrochemical reaction between supplied hydrogen and supplied oxygen.

Therefore, an efficient combined-cycle power generation system can be realized by appropriately combining the gasification unit and the fuel cell, and research and development thereof is in full swing.

Prior art relating to the combined power generation system is disclosed in Korean Patent Registration No. 10-1543168 (August 07, 2015).

An object of the present invention is to provide a fuel cell system capable of reducing costs by supplying synthesis gas (Syngas) generated by a gasification unit to a fuel cell unit and generating electricity, and using uncombusted synthesis gas discharged from a fuel cell unit as fuel for a gasifier To provide a combined power generation system.

According to an aspect of the present invention, there is provided a combined-cycle power generation system including an air separator for separating air into oxygen and nitrogen, a gasification unit for generating syngas by supplying the raw material and oxygen generated from the air separator, A gasifier having a group; A power generator for generating electricity by burning a syngas generated in the gasification unit; A reformer for reforming the synthesis gas produced by the gasification unit into hydrogen and carbon dioxide, an anode for receiving hydrogen and carbon dioxide from the reformer, and a cathode for receiving oxygen from the air separator, And a fuel cell that generates electricity.

The combined-cycle power generation system according to the present embodiment supplies syngas separated from the acid gas eliminator of the gasification unit to the anode of the fuel cell through the reformer, and supplies the generated oxygen from the gas separator to the cathode of the fuel cell. In addition, since the unreacted anode synthesis gas and oxygen in the cathode are supplied to the gasifier of the gasification unit and used, the cost may be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a configuration of a combined power generation system according to a first embodiment of the present invention; FIG.
2 is a view showing a configuration of a combined power generation system according to a second embodiment of the present invention;

It should be noted that, in the specification of the present invention, the same reference numerals as in the drawings denote the same elements, but they are numbered as much as possible even if they are shown in different drawings.

Meanwhile, the meaning of the terms described in the present specification should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

It should be understood that the term "and / or" includes all possible combinations from one or more related items. For example, the meaning of "first item, second item and / or third item" may include not only the first item, the second item or the third item but also two of the first item, Means a combination of all items that can be presented from the above.

It is to be understood that when an element is referred to as being "connected or installed" to another element, it may be directly connected or installed with the other element, although other elements may be present in between. On the other hand, when an element is referred to as being "directly connected or installed" to another element, it should be understood that there are no other elements in between. On the other hand, other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

Hereinafter, a combined power generation system according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing the construction of a combined power generation system according to a first embodiment of the present invention, and FIG. 2 is an enlarged view of a waste heat recovery boiler and a fuel cell shown in FIG.

As shown in the figure, the combined power generation system according to the first embodiment of the present invention may include a gasification unit 100, a power generation unit 200, and a fuel cell unit 300.

First, the gasification unit 100 will be described.

The gasification unit 100 may generate a syngas, which is a combustible gas, by burning a gas raw material, a liquid raw material, a fossil raw material (fossil fuel), or an organic raw material and includes a gasifier 110, an air separator 130, A wastewater treatment device 140 and a purification device 150.

In particular, a system that generates electricity after producing syngas from coal as a raw material is called a coal gasification combined cycle power generation system. Coal may be put into slurry form or into pulverized coal form. The coal in the form of slurry is fed with water, which is an oxidant, with air or oxygen, and coal in the form of pulverized coal is fed with air or oxygen which is an oxidizing agent.

Hereinafter, the use of pulverized coal, which is a fossil raw material, as a raw material will be described as an example.

The gasifier 110 may combust the pulverized coal to produce a raw syngas. A pulverizer 125 for pulverizing coal stored in the coal storage vessel 121 and the coal storage vessel 121 may be provided to supply the pulverized coal to the gasifier 110. [

In order to burn the pulverized coal in the gasifier 110, oxygen, which is an oxidizing agent, is required, and the air separator 130 can generate oxygen by separating air into oxygen and nitrogen. That is, when the compressed air from which the impurities are removed is cooled, the air is separated into low-temperature liquid oxygen and low-temperature liquid nitrogen due to the difference in boiling point of oxygen and nitrogen, and the liquid oxygen separated and generated in the air separator 130 is heat- And may be supplied to the gasifier 110 through the main oxygen conduit 132.

The raw syngas produced by the combustion of the pulverized coal in the gasifier 110 may include carbon dioxide, carbonyl sulfide (COS), and hydrogen sulfide, and carbon dioxide, carbonyl sulfide (COS), and hydrogen sulfide are acid gases.

Coal contains about 2 to 20% of coal fly ash.

Approximately 20% of the coal ash is melted by the high-temperature heat of combustion of the gasifier 110 to become a slag in which various particles are condensed, and a hopper (not shown) communicated with the lower part of the gasifier 110 together with water So that it can be discharged to the outside.

The wastewater processor 140 can process the water discharged from the gasifier 110 and the treated water in the wastewater processor 140 can be reintroduced into the gasifier 110.

The remaining approximately 80% of the coal ash is burned by each particle and scattered according to the flow of the raw syngas, and the purification apparatus 150 can purify the raw syngas containing the coal fly ash produced in the gasifier 110 have.

The purification apparatus 150 includes a dust eliminator 151 for separating and removing dust including fly ash contained in the raw syngas, and a hydrolysis unit 153 for removing sulfur components by hydrolyzing the dust- An acid gas remover 155 for separating the synthesis gas from which the sulfur component has been removed into an acid gas and a pure syngas, and an emitter 157 for separating and discharging the acid gas into sulfur and sulfuric acid.

At this time, the gas from which the sulfur component has been removed in the hydrolysis unit 153 can be introduced into the wastewater treatment unit 140 and treated, and the wastewater treatment unit 140 can transfer the sour gas to the wastewater treatment unit have. Then, the emitter (157) can transfer tail gas (Tail Gsa) to use.

The pure syngas separated from the acid gas eliminator 155 is supplied to the power generator 200 to generate electricity.

Next, the power generation section 200 will be described.

The power generation unit 200 may include a gas turbine 210, a waste heat recovery boiler 220, a steam turbine 230, and a condenser 240.

The gas turbine 210 can receive the pure syngas separated from the acid gas remover 155 and drive the generator. In detail, the gas turbine 210 includes a compressor for compressing air, a combustor for combusting synthesis gas by receiving air and synthesis gas from the compressor and the acid gas remover, respectively, and a combustion gas generated by the combustor And a turbine that drives the generator.

The combustion gas that drives the turbine may be discharged at a high temperature, and the waste heat recovery boiler 220 may generate steam using the exhaust gas discharged from the gas turbine 210.

The exhaust gas introduced into the waste heat recovery boiler 220 and used to generate steam can be purified and discharged. The steam turbine 230 is supplied with steam generated in the waste heat recovery boiler 220, Can be driven. The steam used to drive the steam turbine 230 may be condensed in the condenser 240 and re-introduced into the waste heat recovery boiler 220.

2, the waste heat recovery boiler 220 may include a main body 221, and exhaust gas discharged from the gas turbine 210 flows into one side surface and the other side surface of the main body 221 An inlet portion 221a and a discharge portion 221b formed of a chimney or the like may be respectively formed.

An economizer 221 for heating the water with residual heat of the exhaust gas flowing into the main body 221 in the main body 221 and an economizer 221 for heating the water by heat of the exhaust gas flowing into the main body 221 from the economizer 223 An evaporator 224 for vaporizing the delivered water, and a superheater 225 for heating superheated steam delivered from the evaporator 224 to generate superheated steam. The superheated steam generated in the superheater 225 can generate power while the steam turbine 230 is driven.

A burner 227 for heating the superheater 225 may be installed in the main body 211 on the inflow portion 221a and the burner 227 heats the superheater 225 by burning the fuel.

Next, the fuel cell unit 300 will be described.

The fuel cell unit 300 may include a reformer 310 and a fuel cell 310.

The reformer 310 is capable of reforming the synthesis gas into hydrogen and carbon dioxide by receiving the generated pure syngas separated from the acid gas remover 155 of the gasification unit 100. The fuel cell 320 may include an anode 321 supplied with hydrogen and carbon dioxide and a cathode 325 supplied with oxygen from the air separator 130 of the gasification unit 100 , And a solid oxide fuel cell using a solid oxide as an electrolyte.

The fuel cell 320 generates water by reacting oxygen supplied to the anode 321 with the oxygen ions generated by the reduction reaction of oxygen in the cathode 325 to the anode 321 through the electrolyte. At this time, since electrons are generated in the anode 321 and electrons are consumed in the cathode 325, the anode 321 and the cathode 325 are connected to generate a current to generate electricity.

A synthetic gas pipe line 411 may be installed to supply the pure synthetic gas separated from the acid gas eliminator 155 to the reformer 310 and the synthetic gas pipe line 411 may be provided with a synthetic gas pipe 411, A first valve 413 may be provided to adjust the degree of the valve.

In order to supply the oxygen generated in the air separator 130 to the cathode 325, the main oxygen conduit 132 may be provided with an oxygen branch conduit 421 branched from the oxygen branch conduit 421, A second valve 423 may be provided to adjust the opening and closing degree of the oxygen branch tractor 421.

The combined power generation system according to the first embodiment of the present invention supplies the pure synthetic gas generated by the acid gas remover 155 of the gasification unit 100 to the anode 321 of the fuel cell 320, The oxygen generated in the fuel cell 320 is supplied to the cathode 325 of the fuel cell 320 so that a separate device for supplying fuel and oxygen to the fuel cell 320 is not required. Therefore, the cost can be reduced.

Second Embodiment

FIG. 2 illustrates a configuration of a combined-cycle power generation system according to a second embodiment of the present invention, and only differences from the first embodiment will be described.

As shown, in the combined-cycle power generation system according to the second embodiment of the present invention, among the hydrogen and carbon dioxide supplied to the anode 321, unreacted hydrogen and carbon dioxide are discharged to the outside of the fuel cell 320 And unreacted oxygen in the oxygen supplied to the cathode 325 may be discharged to the outside of the fuel cell 320.

At this time, unreacted synthesis gas discharged from the anode 321 and unreacted oxygen discharged from the cathode 325 may be supplied to the gasifier 110 of the gasification unit 100 and reused. Then, since the gas discharged from the fuel cell 320 can be recycled, the cost can be further reduced.

A gas pipe 431 for supplying the unreacted synthesis gas discharged from the fuel cell 320 and the unreacted oxygen to the gasifier 110 may be installed in the gas pipe 431, And a compressor 433 for supplying the unreacted synthesis gas and the unreacted oxygen to the gasifier 110 may be installed.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Will be clear to those who have knowledge of. Therefore, the scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention.

100: gasifier
110: Gasifier
130: air separator
200:
300: fuel cell unit
320: Fuel cell

Claims (4)

A gasifier having an air separator for separating air into oxygen and nitrogen, and a gasifier for supplying a raw material and oxygen generated in the air separator to produce syngas;
A power generator for generating electricity by burning a syngas generated in the gasification unit;
A reformer for reforming the synthesis gas produced by the gasification unit into hydrogen and carbon dioxide, an anode for receiving hydrogen and carbon dioxide from the reformer, and a cathode for receiving oxygen from the air separator, And a fuel cell for generating electricity. The method according to claim 1,
Wherein unreacted synthesis gas discharged from the anode and unreacted oxygen discharged from the cathode are supplied to the gasifier. 3. The method of claim 2,
Wherein unreacted synthesis gas discharged from the anode and unreacted oxygen discharged from the cathode are compressed and supplied to the gasifier. 3. The method of claim 2,
A gas pipe for supplying an unreacted synthesis gas discharged from the anode and unreacted oxygen discharged from the cathode to the gasifier,
Wherein the gas conduit is provided with a compressor for compressing unreacted synthesis gas discharged from the anode and unreacted oxygen discharged from the cathode.

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