KR20170136138A - Combined cycle power generation system - Google Patents

Abstract

A complex power generation system is disclosed. According to the present invention, the complex power generation system can condense steam generated in a desalination unit by using low-temperature liquid nitrogen or low-temperature liquid oxygen generated in an air separator. Then, the present invention does not require an additional condensation device to condense the steam in order to reduce costs.

Description

{COMBINED CYCLE POWER GENERATION SYSTEM}

The present invention relates to a combined power generation system for condensing vapor of a desalination part using low temperature liquid oxygen or liquid nitrogen produced in an air separator of a gasification part.

Thermal power generation is a method of generating steam by burning gaseous fuel, liquid fuel or fossil fuel (fossil fuel), and generating rotating steam by rotating the rotating equipment. The combustion gas generated during combustion of the fuel There is a problem that the environment is polluted due to discharge.

In order to solve this problem, it is necessary to rotate the gas turbine by the combustion gas generated when the fuel is burned, generate the steam by using the exhaust gas discharged from the gas turbine, rotate the steam turbine by the generated steam A second generation power generation system has been developed and used.

Combined power generation has advantages over thermal power generation, thermal efficiency is better than that of thermal power generation, environmental pollution is less, and restarting time is short. In addition, combined power generation is advantageous in that the construction period of the power plant is shortened compared to the thermal power generation using coal as fuel.

A general combined power generation system includes a desalination unit for desalinating seawater using waste heat of the power generation unit, including a gasification unit for gasifying coal to produce syngas and a power generation unit for generating syngas generated from the gasification unit as fuel It is possible. At this time, the desalination unit heats the seawater using the waste heat of the power generation unit, and condenses the steam generated when heating the seawater to generate fresh water.

However, in the conventional combined-cycle power generation system, a separate condenser is installed to condense the steam generated during the heating of seawater, so that the cost increases.

Prior art relating to the combined power generation system is disclosed in Korean Patent Laid-Open Publication No. 10-2016-0036685 (April 05, 2016).

It is an object of the present invention to provide a combined power generation system capable of solving all the problems of the conventional art.

Another object of the present invention is to provide a combined power generation system capable of reducing costs.

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 liquid oxygen and liquid nitrogen, and a fuel cell for generating syngas by burning fuel, A gasifier having a gasifier; A generator having a condenser for generating syngas generated from the gasification unit as fuel and condensing the steam generated at the time of generation using seawater; And a desalination unit for generating seawater by heating seawater discharged from the condenser to condense the seawater to generate fresh water. The steam generated in the desalination unit is separated into at least one of liquid oxygen and liquid nitrogen generated in the air separator Can be condensed.

In the combined-cycle power generation system according to the present embodiment, the steam generated in the desalination unit can be condensed using low-temperature liquid oxygen or low-temperature liquid nitrogen generated in the air separator. Then, since there is no need for a separate condenser for condensing the steam, the cost can 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;
3 is a view showing a configuration of a combined power generation system according to a third embodiment of the present invention;
4 is a view showing a configuration of a combined-cycle power generation system according to a fourth 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.

1 is a view showing a configuration of a combined-cycle power generation system according to a first embodiment of the present invention.

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 desalination unit 300.

First, the gasification unit 100 will be described.

The gasification unit 100 may combust a gas fuel, a liquid fuel or a fossil fuel to produce a syngas, which is a combustible gas, and the gasifier 110, the air separator 130, the wastewater processor 140, And a purification device 150.

In particular, a system for generating syngas by using coal as fuel and generating electricity 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 the fine coal as the fuel is 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 oxidizer, is required, and oxygen can be generated in the air separator 130. When the compressed air from which 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. The liquid oxygen separated in the air separator 130 may be supplied to the gasifier 110 after heat exchange.

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 flowing into the waste heat recovery boiler 220 and used for generating steam is purified by a denitrification module (not shown) installed inside the waste heat recovery boiler 220 and then discharged through a stack Can be discharged.

The steam turbine 230 can drive another generator while driving the steam generated in the waste heat recovery boiler 220. The steam used to drive the steam turbine 230 is condensed in the condenser 240, Can be reintroduced into the recovery boiler (220).

Since a large amount of cooling water is required to condense the vapor of the condenser 240, the steam of the condenser 240 can be condensed using seawater. At this time, since the seawater discharged after condensing the vapor of the condenser 240 is relatively high in temperature, desalination of the seawater discharged from the condenser 240 can save energy for heating the seawater.

The combined power generation system according to the first embodiment of the present invention can condense the steam generated in the desalination unit 300 using low temperature liquid oxygen or low temperature liquid nitrogen generated in the air separator 130. Then, there is no need for a separate condenser for condensing the steam, so the cost can be reduced.

Next, the condensation of the vapor generated in the desalination unit 300 using the low-temperature liquid oxygen or the low-temperature liquid nitrogen produced in the air separator 130 will be described.

The desalination unit 300 includes a seawater reservoir for storing seawater, a heat source for heating the seawater in the seawater reservoir, a steam line 310 through which the seawater is stored, And a fresh water reservoir 320 in which fresh water generated by condensation of steam of the steam pipe 310 is stored.

The seawater channel 411 may be installed to supply the seawater to the desalination unit 300. The seawater introduced into the seawater channel 411 condenses the vapor of the condenser 240 and is discharged from the condenser 240 . At this time, the seawater discharged from the condenser 240 can be supplied to the desalination unit 300.

A liquid gas pipe 413 through which liquid oxygen or liquid nitrogen produced in the air separator 130 passes may be installed and one side between the liquid gas pipe line 413 and the steam pipe line 310 may be a liquid gas pipe And a heat exchanger 415 for exchanging heat with the steam pipe line 310 at the other side. Then, the vapor of the vapor pathway 310 is condensed by the liquid oxygen or liquid nitrogen generated in the air separator 130.

A first valve 421 for controlling the degree of opening and closing of the seawater conduit 411 and the liquid gas conduit 413 is provided in the seawater conduit 411 and the liquid gas conduit 413 between the condenser 240 and the desalination unit 300, And a second valve 423 may be respectively installed. The amount of liquid oxygen or liquid nitrogen bridged with the heat exchanger 415 by using the second valve 423 can be adjusted by adjusting the amount of seawater supplied to the desalination part 300 using the first valve 421, . The second valve 423 is preferably installed in the liquid gas pipe 413 through which liquid oxygen or liquid nitrogen passes before heat exchange with the heat exchanger 415.

The meaning of the heat exchange between the liquid gas pipe 413 and the heat exchanger 415 means that the liquid oxygen or liquid nitrogen in the liquid gas pipe 413 exchanges heat with the heat exchanger 415. The heat exchanger 415, 415 means heat exchange between the steam of the steam pipe 310 and the heat exchanger 415.

The combined power generation system according to the first embodiment of the present invention condenses and desalvates the steam generated in the desalination unit 300 using low-temperature liquid oxygen or low-temperature liquid nitrogen generated in the air separator 130. In this case, since a separate condenser for condensing the steam generated in the desalination unit 300 is not needed, 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, the combined power generation system according to the second embodiment of the present invention includes a portion of a liquid gas pipe 413 through which liquid oxygen or liquid nitrogen passes before heat exchange with the heat exchanger 415, a heat exchanger 415, The portion of the liquid gas pipe 413 through which the heat exchanged liquid oxygen or liquid nitrogen passes can be communicated by the communicating pipe passage 413a and the communicating pipe passage 413a is provided with the third A valve 425 may be provided. Then, liquid oxygen or liquid nitrogen before heat exchange with the heat exchanger 415 can be bypassed and discharged.

Third Embodiment

FIG. 3 is a block diagram showing a configuration of a combined power generation system according to a third embodiment of the present invention, and only differences from the first embodiment will be described.

As shown in the figure, the combined-cycle power generation system according to the third embodiment of the present invention may include a seawater branch passage 511a branching from the seawater channel 511. One side of the sea water branch passage 511a communicates with the sea water conduit 511 through which sea water passes before the heat exchange with the condenser 240 and the other side communicates with the sea water conduit 511 between the condenser 240 and the desalination unit 300, As shown in FIG.

One side of the heat exchanger 515 is heat-exchanged with the sea water branch passage 511a, and the other side is heat-exchanged with the liquid gas pipe line 513. At this time, the portion of the seawater distribution passage 511a through which the seawater heat-exchanged with the heat exchanger 515 passes may be formed in the form of a coil so as to cover the steam pipe 310. Then, the steam of the steam pipe 310 is condensed by the seawater of the seawater branch passage 511a which has exchanged heat with the liquid oxygen or liquid nitrogen generated in the air separator 130 via the heat exchanger 515.

The combined power generation system according to the third embodiment of the present invention includes a seawater distribution pipe 511a between the heat exchanger 515 and the steam pipe 310 and a seawater distribution pipe 511a which exchanges heat with the steam of the steam pipe 310 And a second valve 523 for controlling the degree of opening and closing of the liquid gas pipe line 513 may be installed in the liquid gas pipe line 513. The degree of opening and closing of the liquid gas pipe 513 is controlled according to the temperature sensed by the temperature sensor 527 so that the liquid gas pipe 513 is exchanged with the sea water of the seawater distribution pipe 511a through the heat exchanger 515, The amount of liquid oxygen or liquid nitrogen in the steam line 513 can be adjusted so that the temperature of the seawater necessary to condense the steam in the steam line 310 can be adjusted.

It is preferable that the second valve 523 is installed at a portion of the liquid gas pipe 513 through which liquid oxygen or liquid nitrogen passes before heat exchange with the heat exchanger 515. [

The meaning of heat exchange between the sea water branch passage 511a and the heat exchanger 515 means that the sea water in the sea water branch passage 511a exchanges heat with the heat exchanger 515 and the heat exchanger 515 Means that liquid oxygen or liquid nitrogen in the liquid gas pipe 513 exchanges heat with the heat exchanger 515. [

Fourth Embodiment

FIG. 4 illustrates a configuration of a combined power generation system according to a fourth embodiment of the present invention, and only differences from the third embodiment will be described.

As shown in the drawing, a portion of the liquid gas pipe 513 through which liquid oxygen or liquid nitrogen passes before heat exchange with the heat exchanger 515 and a portion of the liquid gas pipe 513 through which the liquid oxygen or liquid nitrogen, which has undergone heat exchange with the heat exchanger 515, The third valve 515 can be communicated with the communicating pipe 513a and a third valve 525 may be provided in the communicating pipe 515a to control the opening and closing degree of the communicating pipe 515a. Then, liquid oxygen or liquid nitrogen before heat exchange with the heat exchanger 515 can be bypassed and discharged.

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
130: air separator
200:
240:
300: desalination part

Claims (6)

A gasifier having an air separator for separating air into liquid oxygen and liquid nitrogen, and a gasifier for generating syngas by burning the fuel supplied with oxygen generated in the air separator;
A generator having a condenser for generating syngas generated from the gasification unit as fuel and condensing the steam generated at the time of generation using seawater;
And a desalination unit for generating seawater discharged from the condenser to generate steam and then condensing the seawater to generate fresh water,
Wherein the steam generated in the desalination unit is condensed by at least one of liquid oxygen and liquid nitrogen produced in the air separator. The method according to claim 1,
A seawater pipe for supplying seawater discharged after heat exchange with steam of the condenser to the desalination unit;
A steam pipe through which the steam discharged from the desalination part passes;
A liquid gas pipe through which at least one of liquid oxygen or liquid nitrogen produced in the air separator passes;
Further comprising a heat exchanger for exchanging heat with the liquid gas pipe on one side and heat-exchanging with the steam pipe on the other side. 3. The method of claim 2,
A portion of the liquid gas pipe through which liquid oxygen or liquid nitrogen passes before heat exchange with the heat exchanger and a portion of the liquid gas pipe through which liquid oxygen or liquid nitrogen heat-exchanged with the heat exchanger pass through are communicated with each other by a communication pipe,
Wherein the seawater conduit, the liquid gas conduit, and the communicating conduit between the condenser and the desalination portion are provided with a first valve, a second valve, and a third valve for adjusting opening and closing degree of the seawater conduit, the liquid gas conduit, Respectively. The method according to claim 1,
A seawater pipe for supplying seawater discharged after heat exchange with steam of the condenser to the desalination unit;
A steam pipe through which the steam discharged from the desalination part passes;
One side of which is connected to the seawater channel through which seawater passes before heat exchange with the condenser and the other side is connected to the seawater channel between the condenser and the desalination unit;
A liquid gas pipe through which at least one of liquid oxygen or liquid nitrogen produced in the air separator passes;
Further comprising a heat exchanger for exchanging heat with one of the seawater distribution passages and the other of the heat exchanges with the liquid gas passage,
And a portion of the seawater distribution passage through which seawater heat-exchanged with the heat exchanger passes is formed in a coil shape to surround the steam pipe. 5. The method of claim 4,
A first valve is provided in the seawater channel between the condenser and the desalination unit to adjust the degree of opening and closing of the seawater channel,
A temperature sensor for sensing the temperature of seawater is provided in the seawater distribution pipe between the heat exchanger and the steam pipe,
And a second valve for adjusting the degree of opening / closing of the liquid gas pipe according to a temperature sensed by the temperature sensor is installed in the liquid gas pipe. 6. The method of claim 5,
A portion of the liquid gas pipe through which liquid oxygen or liquid nitrogen passes before heat exchange with the heat exchanger and a portion of the liquid gas pipe through which liquid oxygen or liquid nitrogen heat-exchanged with the heat exchanger pass through are communicated with each other by a communication pipe,
And a third valve for adjusting the degree of opening and closing of the communicating pipe is installed in the communicating pipe passage.

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