KR102195210B1 - Combined cycle power generation system - Google Patents

Abstract

A combined power generation system is disclosed. In the combined power generation system according to the present invention, since the steam generated in the cooler that cools the syngas generated in the gasifier of the gasifier is supplied to the reformer of the fuel cell part and used, there is no need to separately generate the steam used in the reformer. . Therefore, there may be an effect of reducing the cost.

Description

Combined Cycle Power Generation System {COMBINED CYCLE POWER GENERATION SYSTEM}

The present invention relates to a combined power generation system for supplying steam generated from a cooler for cooling a syngas generated in a gasifier of a gasifier to a reformer of a fuel cell.

In Combined Cycle Power Generation, gaseous raw materials, liquid raw materials, fossil raw materials, or organic raw materials are gasified and purified, and then syngas is generated, and the gas turbine is rotated with the combustion gas generated when the synthetic gas is combusted. It is a technology that generates power as a primary, generates steam by using exhaust gas discharged from a gas turbine, and then rotates the steam turbine with the generated steam to generate secondary power. Combined power generation has the advantage of having excellent thermal efficiency and low environmental pollution because it generates power in two stages.

In addition, a fuel cell is a technology that continuously supplies fuel and oxygen containing hydrogen, and generates electric energy through an electrochemical reaction between supplied hydrogen and supplied oxygen.

Therefore, if the gasification unit and the fuel cell are properly combined, an efficient combined cycle power generation system can be implemented, and thus research and development are underway.

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

An object of the present invention may be to provide a combined power generation system capable of reducing cost by supplying steam generated in a cooler that cools the syngas generated in the gasifier of the gasifier to the reformer of the fuel cell unit.

A combined cycle power generation system according to an embodiment of the present invention for achieving the above object includes a gasifier that generates syngas by receiving oxygen and raw materials, and a cooler that generates steam while cooling the syngas generated in the gasifier. A gasifier having a; A power generation unit for generating electricity by burning the syngas generated by the gasification unit; An electrochemical reaction while having a reformer receiving steam and reforming the syngas generated in the gasification unit into hydrogen and carbon dioxide, an anode receiving hydrogen and carbon dioxide from the reformer, and a cathode receiving oxygen. It includes a fuel cell unit having a fuel cell that generates power, and the steam supplied to the reformer may be steam generated from the cooler.

In the combined power generation system according to the present embodiment, since the steam generated by the cooler that cools the syngas generated by the gasifier of the gasifier is supplied to the reformer of the fuel cell unit and used, it is necessary to separately generate the steam used in the reformer. none. Therefore, there may be an effect of reducing the cost.

1 is a diagram showing the configuration of a combined power generation system according to a first embodiment of the present invention.
2 is a diagram showing the configuration of a combined power generation system according to a second embodiment of the present invention.

In the present specification, in adding reference numerals to elements of each drawing, it should be noted that only the same elements have the same number as possible, even if they are indicated on different drawings.

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

Singular expressions should be understood as including plural expressions unless clearly defined differently in context, and terms such as “first” and “second” are used to distinguish one element from other elements, The scope of rights should not be limited by these terms.

It is to be understood that terms such as "comprise" or "have" do not preclude the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

The term “at least one” is to be understood as including 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 2 among the first item, the second item, and the third item as well as the first item, the second item, and the third item. It means a combination of all items that can be presented from more than one.

The term “and/or” is to be understood as including all possible combinations from one or more related items. For example, the meaning of “the first item, the second item and/or the third item” means two of the first item, the second item or the third item as well as the first item, the second item, or the third item. It means a combination of all items that can be presented from the above.

When a component is referred to as being "connected or installed" to another component, it should be understood that it may be directly connected or installed to the other component, but other components may exist in the middle. On the other hand, when a component is referred to as "directly connected or installed" to another component, it should be understood that there is no other component in the middle. On the other hand, other expressions describing the relationship between the constituent elements, that is, "between" and "directly between" or "adjacent 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.

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

As shown, 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 syngas, which is a combustible gas, by burning gas raw materials, liquid raw materials, fossil raw materials, or organic raw materials. The gasifier 110, the air separator 140, It may include a wastewater treatment unit 150 and a purification device 160.

In particular, a system that generates syngas using coal as a raw material and then generates power is referred to as a coal gasification combined cycle power generation system. Coal may be introduced in the form of a slurry or pulverized coal. In the slurry form of coal, water is introduced together with air or oxygen as an oxidizing agent, and in the pulverized coal form, steam is introduced together with air or oxygen as an oxidizing agent.

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

The gasifier 110 may generate raw syngas by burning pulverized coal. In order to supply the pulverized coal to the gasifier 110, a coal storage container 131 and a pulverizer 135 for pulverizing coal stored in the coal storage container 131 may be provided.

Oxygen, which is an oxidizing agent, is required to burn the pulverized coal in the gasifier 110, and the air separator 140 may generate oxygen by separating air into oxygen and nitrogen. That is, when the compressed air from which impurities have been removed is cooled, the air is separated into low-temperature liquid oxygen and low-temperature liquid nitrogen due to the difference between the boiling points of oxygen and nitrogen, and the liquid oxygen separated by the air separator 140 undergoes heat exchange. After that, it may be supplied to the gasifier 110 through the main oxygen pipe 142.

The raw syngas generated by 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 2-20% of coal ash, a non-combustible material.

Approximately 20% of the coal ash is melted by the high-temperature combustion heat of the gasifier 110 to become slag in which several particles are condensed, and a hopper (not shown) installed in communication with the lower portion of the gasifier 110 with water It can be discharged to the outside through.

The wastewater treatment unit 150 may treat water discharged from the gasifier 110, and the water treated by the wastewater treatment unit 150 may be re-inflowed into the gasifier 110.

And, the remaining approximately 80% of the coal ash may be burned for each particle, scattered according to the flow of the raw syngas, and cooled in the cooler 120. At this time, since the syngas generated by the gasifier 110 is high temperature around 1,500° C., it may be quenched and then cooled to about 900° C. and introduced into the cooler 120.

In addition, the cooler 120 may cool the syngas to approximately 200°C and supply it to the purification device 160. At this time, the cooler 120 may cool the syngas using cooling water, and when the syngas is cooled in the cooler 120, steam may be generated. And, the steam generated in the cooler 120 may be used for combined power generation.

The purification apparatus 160 may purify raw syngas containing coal ash generated by the gasifier 110.

The purification device 160 is a dust remover 161 that separates and removes dust including fly ash contained in the raw syngas and collects and removes dust, and a hydrolyzer 163 that hydrolyzes the synthetic gas from which the dust is removed to remove sulfur components. ), an acidic gas remover 165 for separating the synthetic gas from which the sulfur component has been removed into acidic gas and pure synthetic gas, and a sulfur remover 167 for separating and discharging the acidic gas into sulfur and sulfuric acid.

At this time, the gas from which the sulfur component has been removed from the hydrolyzer 163 may be introduced into the wastewater treatment unit 150 and be treated, and the wastewater treatment unit 150 may transfer the sour gas to the sulfur eliminator 167. have. And, the sulfur remover 167 may transfer the tail gas (Tail Gsa) to the use place.

The pure synthetic gas separated by the acidic gas remover 165 may be supplied to the power generation unit 200 to generate power.

Next, the power generation unit 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 may receive the pure syngas separated from the acid gas remover 165 to drive the generator. In detail, the gas turbine 210 is driven by a compressor for compressing air, a combustor for combusting the syngas by receiving air and syngas from the compressor and the acid gas eliminator, respectively, and the combustion gas generated in the combustor. It may include a turbine that drives the generator.

The combustion gas driving 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 may be purified and then discharged, and the steam turbine 230 receives and drives the steam generated from the waste heat recovery boiler 220 while driving another generator. Can drive. In addition, 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.

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 may receive the generated pure syngas separated by the acidic gas remover 165 of the gasifier 100 and may reform the syngas into hydrogen and carbon dioxide. In addition, the fuel cell 320 may include an anode 321 receiving hydrogen and carbon dioxide and a cathode 325 receiving oxygen, and a solid oxide fuel cell using a solid oxide as an electrolyte. It is preferable to be provided with.

In the fuel cell 320, oxygen ions generated by a reduction reaction of oxygen in the cathode 325 move to the anode 321 through an electrolyte and react with hydrogen supplied to the anode 321 to generate water. At this time, since electrons are generated in the anode 321 and electrons are consumed in the cathode 325, electricity is generated by connecting the anode 321 and the cathode 325 to generate electric current.

When reforming by receiving pure syngas from the reformer 310, steam is required to reform the gas into a gas containing a large amount of hydrogen. At this time, the steam supplied to the reformer 310 may be steam generated from the cooler 120 of the gasifier 100. Then, since there is no need for a separate device for generating steam supplied to the reformer 310, cost is reduced.

A steam pipe line 411 may be installed to supply the steam generated by the cooler 120 to the reformer 310, and the steam pipe line 411 is a first for controlling the degree of opening and closing of the steam pipe line 411. A valve 413 may be installed.

The combined power generation system according to the first embodiment of the present invention cools the high-temperature synthetic gas generated in the gasifier 110 of the gasifier 100 in the cooler 120 to cool the dust remover 161 of the filter device 160 To be supplied. At this time, steam is generated in the cooler 120, and the steam generated in the cooler 120 is supplied to the reformer 310 of the fuel cell unit 300 and used. Then, since it is not necessary to separately generate the steam used in the reformer 120, cost can be reduced.

Embodiment 2

2 is a diagram showing a configuration of a combined power generation system according to a second embodiment of the present invention, and only differences from the first embodiment are described.

As shown, in the combined power generation system according to the second embodiment of the present invention, air generated by the air separator 140 of the gasifier 100 may be supplied to the cathode 325 of the fuel cell 320. In addition, unreacted oxygen among the oxygen supplied to the cathode 325 may be resupplied to the gasifier 120 and used.

In order to supply the oxygen generated in the air separator 140 to the cathode 325 and to resupply the unreacted oxygen discharged from the cathode 325 to the gasifier 120, the main oxygen pipe 142 is provided with an oxygen distribution pipe. 421 can be installed branch. In addition, a second valve 423 may be installed in the oxygen branch path 421 to adjust the degree of opening and closing of the oxygen branch path 421.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and that various substitutions, modifications, and changes are possible within the scope of the technical spirit of the present invention. It will be obvious to those who have the knowledge of. Therefore, the scope of the present invention is indicated by the claims to be described later, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

100: gasification unit
110: gasifier
120: cooler
140: air separator
200: power generation department
300: fuel cell unit
310: reformer
320: fuel cell

Claims (3)

A gasifier having a gasifier receiving oxygen and raw materials to generate syngas and a cooler generating steam while cooling the syngas generated in the gasifier;
A gas turbine that generates power by burning the syngas generated in the gasification unit, a waste heat recovery boiler that generates steam using exhaust gas discharged from the gas turbine, and a steam generated from the waste heat recovery boiler are supplied and driven. A power generation unit having a steam turbine to generate power;
An electrochemical reaction while having a reformer receiving steam and reforming the syngas generated in the gasification unit into hydrogen and carbon dioxide, an anode receiving hydrogen and carbon dioxide from the reformer, and a cathode receiving oxygen. It includes a fuel cell unit having a fuel cell to generate power,
The steam supplied to the reformer is steam generated by the cooler while the gasifier generates syngas to be supplied to the gas turbine. The method of claim 1,
The gasifier further comprises an air separator for separating air into oxygen and nitrogen and supplying it to the gasifier,
Combined power generation system, characterized in that the oxygen separated by the air separator is supplied to the cathode. The method of claim 2,
Combined power generation system, characterized in that the unreacted oxygen discharged from the cathode is supplied to the gasifier.

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