KR20170136139A - 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 cool air introduced into a compressor of a gas turbine of a power generation portion by using low-temperature liquid oxygen or liquid nitrogen generated in an air separator. In this case, since there is no need for an additional cooling device to cool the air, cost can be reduced. In addition, since vapors of a condenser of the power generation portion are condensed using cooled seawater, the vapors of the condenser can be condensed with a relatively small amount of seawater. In this case, the present invention is able to pump the seawater by using a pump of a relatively small volume, and to minimize damage of a channel through which the seawater passes.

Description

{COMBINED CYCLE POWER GENERATION SYSTEM}

The present invention relates to a combined power generation system for cooling air supplied to a compressor of a gas turbine using low temperature liquid oxygen or liquid nitrogen produced in an air separator of a gasification section.

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 the above-mentioned problems, it is necessary to rotate the gas turbine by the combustion gas generated when the fuel is burned, to generate the steam by using the exhaust gas discharged from the gas turbine, Has been developed and used as a secondary power source.

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.

Generally, a combined power generation system has a gasification unit for gasifying coal to produce a syngas, and a power generation unit for generating syngas generated from the gasification unit as fuel. The gas turbine of the power generation unit includes a compressor for compressing air, And a turbine driven by a combustion gas generated when the synthesis gas is combusted.

When the temperature of the air flowing into the compressor of the gas turbine is low, the density of the air is increased so that the efficiency of the compressor is improved and the efficiency of the gas turbine is improved. Therefore, the efficiency of the power generation section is improved.

However, in the conventional combined power generation system, a separate cooling device is installed and used to lower the temperature of the air supplied to the compressor of the gas turbine. This has the disadvantage that the cost increases.

Prior art relating to the combined power generation system is disclosed in Korean Patent Laid-Open Publication No. 10-1998-0009763 (April 30, 1998).

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 gas turbine for generating electricity by driving the syngas generated by the gasification unit as fuel and a generator for condensing steam generated during power generation using seawater, wherein the gas turbine includes a compressor for compressing air, And a turbine driven by the combustion gas generated in the combustor, wherein the air introduced into the compressor is supplied to the compressor through the liquid oxygen And / or liquid nitrogen.

In the combined-cycle power generation system according to the present embodiment, the air introduced into the compressor of the gas turbine of the power generation section is cooled using low-temperature liquid oxygen or liquid nitrogen generated in the air separator. Then, since there is no need for a separate cooling device for cooling the air, the cost can be reduced.

Since the condensed steam of the condenser of the power generation section is condensed by using the cooled seawater, the vapor of the condensate can be condensed with a relatively small amount of seawater. Then, it is possible to pump the seawater by using a relatively small capacity pump, and it is possible to minimize the damage of the pipeline through which the seawater passes.

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 the gasification unit 100 and the power generation unit 200.

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 combustor 213 that receives air and synthesis gas from a compressor 211, a compressor 211, and an acid gas remover 155, And a turbine 215 for driving the generator while being driven by the combustion gas generated in the combustion chamber 213.

The combustion gas that drives the turbine 215 can be discharged at a high temperature and the waste heat recovery boiler 220 can generate steam using the exhaust gas discharged from the turbine 215 of 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).

When the temperature of the air flowing into the compressor 211 is low, the density of the air is increased, so that the efficiency of the compressor 211 can be improved. As a result, the efficiency of the gas turbine 210 can be improved and the efficiency of the power generator 200 can be improved.

The combined power generation system according to the first embodiment of the present invention can cool the air flowing into the compressor 211 using low temperature liquid oxygen or low temperature liquid nitrogen generated in the air separator 130. This eliminates the need for a separate cooling device for cooling the air, so that the cost can be reduced.

The cooling of the air flowing into the compressor 211 using the low temperature liquid oxygen or the low temperature liquid nitrogen generated in the air separator 130 will be described.

A seawater pipe 311 through which seawater passes may be installed. The sea water pipeline 311 can supply seawater to the condenser 240 and can be used as cooling water for cooling the condenser 240 vapor. Since a large amount of cooling water is required to cool the steam of the condenser 240, it is convenient to use seawater.

When the seawater conduit 311 passes through the condenser 240, the seawater in the seawater conduit 311 and the vapor in the condenser 240 exchange heat, so that the condensate in the condenser 240 is condensed. The meaning of the heat exchange between the sea water of the sea water pipeline 311 and the steam of the condenser 240 is equivalent to the meaning that the sea water pipeline 311 and the condenser 240 exchange heat.

The liquid gas pipeline 313 through which at least one of the liquid oxygen or liquid nitrogen produced in the air separator 130 passes can be installed and one side is heat exchanged with the sea water pipeline 311 and the other side is connected to the liquid gas pipeline A heat exchanger 315 for exchanging heat with the heat exchanger 313 may be installed.

The meaning of the heat exchange between the sea water line 311 and the heat exchanger 315 means that the sea water of the sea water line 311 exchanges heat with the heat exchanger 315 and the heat exchanger 315 exchanges heat with the liquid gas pipe line 313. [ It is natural that liquid oxygen or liquid nitrogen in the liquid gas pipe 313 exchanges heat with the heat exchanger 315.

Then, the sea water line 311 and the liquid gas pipe line 313 exchange heat with each other through the heat exchanger 315, so that the seawater in the sea water line 311 is cooled. The meaning of the heat exchange between the sea water duct 311 and the liquid gas duct 313 is equivalent to the meaning that the sea water of the sea water duct 311 and the liquid oxygen or liquid nitrogen of the liquid gas duct 313 are heat exchanged.

An air duct 321 for supplying air to the compressor 211 may be installed and an air cooler 323 may be installed in the air duct 321. At this time, the air cooler 323 can perform heat exchange with the sea water heat-exchanged with the heat exchanger 315. More specifically, the sea water branch passage 311a can be branched at a portion of the sea water pipe 311 through which the cooled seawater passes through the heat exchanger 315, and the sea water branch passage 311a is divided into air And can pass through the cooler 323. Then, the air in the air cooler 323 is cooled by the seawater cooled by heat exchange with the low-temperature liquid oxygen or the low-temperature liquid nitrogen generated in the air separator 130, and the air cooled in the air cooler 323 is supplied to the compressor 211).

The one end side of the sea water branch passage 311a communicates with the sea water pipeline 311 between the heat exchanger 315 and the condenser 240 and the other end side passes through the air cooler 323, As shown in Fig. When the sea water branch passage 311a passes through the air cooler 323, seawater in the seawater branch passage 311a and air in the air cooler 323 heat-exchange.

A first valve 331 for adjusting the amount of liquid oxygen or liquid nitrogen supplied to the heat exchanger 315 by adjusting the degree of opening and closing of the liquid gas pipe line 313 is installed in the liquid gas pipe line 313 .

A first temperature sensor 333a may be installed in the air pipe 321 between the air cooler 323 and the compressor 211 to detect the temperature of the air flowing into the compressor 211, The first valve 311a may be provided with a second valve 333b for controlling the degree of opening and closing of the seawater branch passage 311a. The amount of seawater in the seawater branch passage 311a for heat-exchanging with the air of the air cooler 323 is adjusted by adjusting the degree of opening and closing of the seawater branch passage 311a according to the temperature sensed by the first temperature sensor 333a Can be adjusted. Accordingly, the temperature of the air flowing into the compressor 211 can be optimally adjusted.

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.

The combined power generation system according to the second embodiment of the present invention includes a portion of the liquid gas pipe 313 through which liquid oxygen or liquid nitrogen passes before heat exchange with the heat exchanger 315 and the heat exchanger 315 The portion of the liquid gas pipe 313 through which the heat exchanged liquid oxygen or liquid nitrogen passes can be communicated by the communicating pipe passage 313a and the communicating pipe passage 313a is provided with the fourth pipe passage 313a for controlling the degree of opening / A valve 335 may be provided. Then, liquid oxygen or liquid nitrogen before heat exchange with the heat exchanger 315 can be bypassed and discharged.

Third Embodiment

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

As shown in the figure, the combined power generation system according to the third embodiment of the present invention includes a seawater conduit 311 between the heat exchanger 315 and the condenser 240, 2 temperature sensor 337a and a fourth valve 337b for adjusting the opening and closing degree of the sea water conduit 311 may be installed. Thus, the temperature of the seawater flowing into the condenser 240 can be appropriately maintained.

The combined power generation system according to the present embodiment cools the air flowing into the compressor 211 using low temperature liquid oxygen or low temperature liquid nitrogen generated in the air separator 130. In this case, since a separate cooling device for cooling the air flowing into the compressor 211 is not required, the cost can be reduced.

Then, the steam of the condenser 240 is cooled using the cooled seawater, so that the vapor of the condenser 240 can be condensed with a small amount of seawater. Then, a relatively small capacity pump can be used to pump the seawater, minimizing damage to the channel through which the seawater passes.

Fourth Embodiment

FIG. 4 illustrates only the differences between the hybrid power generation system according to the third embodiment of the present invention and the second embodiment and the third embodiment.

As shown, the combined power generation system according to the fourth embodiment of the present invention may include a controller 340. The controller 340 can control the second valve 333b that receives the temperature of the air flowing into the compressor 211 from the first temperature sensor 333a and adjusts the degree of opening and closing of the seawater distribution line 311a And a fourth valve 337b for receiving the temperature of the seawater flowing into the condenser 240 from the second temperature sensor 337a and controlling the degree of opening and closing of the seawater pipe 311. [

At this time, the controller 340 may control the second valve 333b and the fourth valve 337b in consideration of the efficiency of the combined power generation system including the power generation unit 200. [ In detail, since the liquid oxygen or liquid nitrogen generated in the air separator 130 is finite, the air flowing into the compressor 211 can not be cooled indefinitely, and the seawater flowing into the condenser 240 can not be cooled indefinitely . Therefore, it is necessary to determine the degree of cooling of the air flowing into the compressor 211 and the degree of cooling of the seawater flowing into the condenser 240 in consideration of the efficiency of the combined-cycle power generation system, The degree of cooling of the air flowing into the condenser 240 and the degree of cooling of the seawater flowing into the condenser 240 should be determined. That is, the controller 340 controls the second valve 333b and the fourth valve 337b so that the combined-cycle power generation system can achieve the optimum efficiency after forming the above-described conditions into a table. 311a and the sea water line 311 can be adjusted.

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:
210: Gas turbine
211: Compressor
323: Air cooler
340: controller

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 gas turbine generating electricity by driving the syngas generated by the gasification unit with fuel, and a generator having a condenser for condensing steam generated during power generation using seawater,
Wherein the gas turbine includes a compressor for compressing air, a combustor for supplying a synthesis gas and air from the gasifier and the compressor, a turbine for combusting a synthesis gas, and a turbine driven by a combustion gas generated in the combustor,
Wherein the air introduced into the compressor is cooled by at least one of liquid oxygen and liquid nitrogen generated in the air separator. The method according to claim 1,
A seawater pipe for supplying seawater to the condenser;
A liquid gas pipe through which at least one of liquid oxygen or liquid nitrogen produced in the air separator passes;
A heat exchanger in which one side exchanges heat with the seawater pipe and the other side exchanges heat with the liquid gas pipe;
An air pipe for supplying air to the compressor;
An air cooler installed in the air pipe and performing heat exchange with seawater heat-exchanged with the heat exchanger to cool the air;
Further comprising: a seawater distribution line branched from the seawater pipe through which the seawater heat-exchanged with the heat exchanger passes and supplies seawater to the air cooler. 3. The method of claim 2,
Wherein the liquid gas pipe is provided with a first valve for regulating the amount of liquid oxygen or liquid nitrogen supplied to the heat exchanger by regulating the opening degree of the liquid gas pipe,
A first temperature sensor for sensing a temperature of air flowing into the compressor is installed in the air pipe between the air cooler and the compressor,
And a second valve for adjusting the degree of opening and closing of the seawater distribution pipe according to a temperature sensed by the first temperature sensor is installed in the seawater distribution pipe. The method of claim 3,
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. The method of claim 3,
A second temperature sensor for sensing the temperature of the seawater flowing into the condenser, and a fourth valve for controlling the opening and closing degree of the seawater pipe according to the temperature sensed by the second temperature sensor, Respectively. 6. The method of claim 5,
Further comprising a controller for controlling the second valve and the fourth valve in accordance with the temperature received by the first temperature sensor, the temperature received by the second temperature sensor, the temperature of the atmosphere, and the temperature of the seawater. Power generation system.

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