KR20210093089A - Combined power generation system - Google Patents

Abstract

The present invention, a boiler for generating steam by circulating the heat generated by the combustion so that complete combustion of the fuel can be achieved in oxygen condition; a steam turbine configured to be driven by receiving the steam generated by the boiler; a gasifier configured to receive fossil fuel and high-temperature carbon dioxide generated from the boiler to generate and discharge syngas through thermal decomposition and gasification reaction; a gas turbine configured to be driven by receiving the synthesis gas generated from the gasifier; And it provides a combined power generation system including a storage tank is formed to enable storage of the char (char) generated by the pyrolysis and gasification reaction in the gasifier.

Description

Combined power generation system {COMBINED POWER GENERATION SYSTEM}

The present invention relates to a combined power generation system using a steam turbine and a gas turbine together.

The combined cycle power system is a boiler that generates steam by circulating the heat generated by the combustion so that the fuel can be completely burned under oxygen conditions, and a fossil fuel and high-temperature carbon dioxide generated from the boiler are supplied to the pyrolysis and gasification reaction. It consists of two reaction parts: a gasifier that produces and discharges syngas by In addition, in the pyrolysis and gasification reactor, devolatilization of fuel and gasification reaction using carbon dioxide as the main reaction gas occur, and in the boiler, only carbon dioxide is contained in the flue gas through the combustion reaction under oxygen conditions, and it has a combined power generation process configuration. Through this, the boiler drives the steam turbine and the gasifier drives the gas turbine, so that high-efficiency power generation of the combined power generation system is possible.

1 is a conceptual diagram illustrating an example of a configuration for a conventional combined cycle power generation system (10).

Referring to FIG. 1 , however, as described above, the conventional combined cycle power generation system 10 includes a boiler 11 , a steam turbine 12 , a gasifier 13 , and a gas turbine 14 .

The boiler 11 receives the air separated by the air separation unit (ASU) 10b from the oxygen flow control valve 10c. A reaction in which the fuel and air supplied through the oxygen flow control valve 10c are burned takes place in the boiler 11 . Through the combustion reaction, the boiler 11 generates steam.

The steam turbine 12 is driven by receiving steam generated from the boiler 11 and generates electricity.

The gasifier 13 receives the air separated by the air separation unit (ASU) 10b from the oxygen flow control valve 10d, and fuel is supplied from the fuel supply unit 10a. And the high-temperature carbon dioxide generated in the boiler 11 is supplied to the gasifier 13 through the flue gas flow control valves 11a and 11b, and thermal decomposition and gasification reactions occur together with the air and fuel to generate syngas.

The gas turbine 14 receives the syngas generated by pyrolysis and gasification reaction in the gasifier 13 through the syngas control unit 13d and the combustor 13e, and is driven to produce electricity.

However, in the case of the conventional combined cycle power generation system 10, char generated in the gasifier 13 is supplied to the boiler 11 without storage in a storage tank. Therefore, the input amount of char is inevitably determined by the operating conditions of the gasifier 13, so the conventional combined power generation system 10 cannot control the amount of power generation.

On the other hand, the conventional combined cycle power generation system 10 does not have a syngas burner. Therefore, since the syngas discharged from the gasifier 13 cannot be used as a fuel, the conventional combined power generation system 10 was unable to efficiently generate power.

On the other hand, the conventional combined power generation system 10 does not include a syngas burner and a syngas distribution unit, so it is not possible to supply syngas to the syngas burner and use it as a fuel for starting the boiler 11, so there is an uneconomic problem .

On the other hand, the conventional combined cycle power generation system 10 does not include a steam supply unit. Therefore, the hydrogen rate that can be obtained even if the syngas discharged by the pyrolysis and gasification reaction from the gasifier 13 is introduced into the syngas purification units 13a' and 13b' through the syngas distribution unit 13a and purified This was low, and it was insufficient to drive the hydrogen gas turbine using the hydrogen stored in the hydrogen storage unit 13c.

Meanwhile, the conventional combined cycle power generation system 10 further includes a heat exchanger 14a and a direct contact heat exchanger (DCC) 14b for heating the steam of the steam turbine 12 by using the heat of the gas turbine 14 . can do. In addition, the conventional combined cycle power generation system 10 may further include a CPU (14c) and a recirculation blower (11d). And the exhaust gas discharged through the combustion reaction in the boiler 11 may be stored in the carbon dioxide storage unit 14d through the recirculation exhaust gas control valve 11c.

However, as described above, in the case of the prior art, the char generated in the gasifier is not stored in a storage tank but is directly supplied to the boiler. For this reason, it was impossible to control the amount of power generation of the combined cycle power generation system because the input amount of char was inevitably determined by the operating conditions of the gasifier.

In addition, in the case of the conventional combined power generation system, the syngas discharged from the gasifier is burned only in the gas turbine, and there is no additional use of the syngas, so it is difficult to efficiently generate power.

In addition, in the case of the conventional combined power generation system, there was a problem in that the hydrogen yield of the syngas discharged from the gasifier was low, so that the utility was low in obtaining hydrogen from the syngas and generating power using the hydrogen.

One object of the present invention is to propose a combined power generation system capable of controlling the amount of power generated by a steam turbine and a gas turbine by controlling the amount of char supplied to a boiler.

Another object of the present invention is to provide a combined power generation system capable of increasing the temperature of steam in a boiler using syngas discharged from a gasifier.

Another object of the present invention is to provide a combined power generation system configured to convert and store the synthesis gas discharged from the gasifier into hydrogen when the production of hydrogen is required.

In order to achieve the above object of the present invention, the combined cycle power generation system according to an embodiment of the present invention is a boiler for generating steam by circulating the heat generated by the combustion so that the fuel can be completely burned in an oxygen condition. ; a steam turbine configured to be driven by receiving the steam generated by the boiler; a gasifier configured to receive fossil fuel and high-temperature carbon dioxide generated from the boiler to generate and discharge syngas through thermal decomposition and gasification reaction; a gas turbine configured to be driven by receiving the synthesis gas generated from the gasifier; and a storage tank formed to allow storage of char generated by the thermal decomposition and gasification reaction in the gasifier.

The combined cycle power system may further include a supply unit configured to adjust the load of the boiler by adjusting the amount of the char supplied to the boiler from the storage tank.

The combined cycle power system may further include a control unit for controlling the supply unit to supply the char stored in the storage tank to the boiler so that the steam is generated in the boiler.

The boiler may further include a syngas burner configured to generate the steam by using the syngas discharged from the gasifier as a fuel.

The combined cycle power system may further include a syngas distribution device for injecting the syngas generated in the gasifier into the syngas burner so that the syngas can be used to increase the temperature of the steam generated in the boiler. can

The combined cycle power system may further include a water vapor supply unit for supplying water vapor to the gasifier to increase the hydrogen yield of the synthesis gas generated in the gasifier.

The combined cycle power system may further include a controller configured to supply the steam from the steam supply unit to the boiler to increase the temperature of the steam generated in the boiler by using the steam.

The combined power generation system may further include a synthesis gas purification unit connected to the discharge unit of the gasifier from which the synthesis gas is discharged, and made to be obtained by purifying hydrogen among the synthesis gas generated in the gasifier.

The combined power generation system may include a hydrogen gas turbine configured to drive a generator using the hydrogen generated by the synthesis gas purification unit.

In the first operation mode in which the combined power generation system requires an increase in power generation, the combined power generation system reduces the supply amount of the char supplied from the gas turbine to the boiler, and burns the synthesis gas in the gasifier. It may further include a control unit configured to increase the amount of power generation of the gas turbine.

The synthesis gas purification unit includes a hydrogen storage unit for storing the hydrogen, and in the second operation mode in which the production of hydrogen is required, the combined power generation system stores the hydrogen purified by the synthesis gas purification unit in the hydrogen storage unit. It may further include a control unit for storing and driving the hydrogen gas turbine using the hydrogen stored in the hydrogen storage unit.

According to the present invention having the above configuration, a storage tank for storing char generated in the gasifier is installed, and the amount of char supplied to the boiler is adjusted to control the amount of power generation by the steam turbine and the gas turbine. Therefore, it is possible to overcome the conventional technical limitations in which the input amount of char is determined by the operating conditions of the gasifier.

In addition, the present invention can minimize the use of auxiliary fuel by not only burning the syngas discharged from the gasifier in the gas turbine, but also injecting it into the boiler combustion furnace through the syngas distribution unit and using it as a fuel for starting the boiler. .

In addition, the present invention can implement ultra-clean power generation that does not require the capture and storage of carbon dioxide by increasing the hydrogen rate in the syngas discharged from the gasifier by using the water vapor supply unit and enabling power generation using hydrogen.

1 is a conceptual diagram illustrating an example of a configuration for a conventional combined cycle power generation system.
2 is a conceptual diagram illustrating a combined cycle power generation system according to an embodiment of the present invention.
3 is a flowchart illustrating a first operation mode and a normal operation mode requiring an increase in generation amount in the combined cycle power generation system shown in FIG. 2 .
4 is a flowchart illustrating a second operation mode and a general operation mode requiring hydrogen production in the combined cycle power generation system shown in FIG. 2 .

Hereinafter, the combined power generation system related to the present invention will be described in more detail with reference to the drawings. In the present specification, the same and similar reference numerals are assigned to the same and similar components in different embodiments, and the description is replaced with the first description. As used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise.

2 is a conceptual diagram illustrating the combined cycle power generation system 100 according to an embodiment of the present invention.

Referring to FIG. 2 , the combined cycle power generation system 100 includes a boiler 110 , a steam turbine 120 , a gasifier 130 , a gas turbine 140 , and a storage tank 150 . The combined cycle power generation system 100 may include a supply unit 160 .

The boiler 110 receives the air separated by the air separation unit (ASU) 102 through the oxygen flow control valve 103 . A reaction in which the air supplied through the oxygen flow control valve 103 and fuel is combusted occurs in the boiler 110 . Through the combustion reaction, the boiler 110 generates steam.

The steam turbine 120 is driven by receiving the steam generated by the boiler 110 and generates electricity.

The gasifier 130 receives the air separated by the air separation unit (ASU) 102 through the oxygen flow control valve 104 , and fuel is supplied through the fuel supply unit 101 . And the high-temperature carbon dioxide generated in the boiler 110 is supplied to the gasifier 130 through the flue gas flow control valves 112 and 113, and thermal decomposition and gasification reactions occur together with the air and fuel to generate syngas.

The gas turbine 140 receives syngas generated by thermal decomposition and gasification reaction in the gasifier 130 through the syngas control unit 134 and the combustor 135 and is driven to produce electricity.

In the storage tank 150 , char generated by thermal decomposition and gasification reaction in the gasifier 130 is stored. Accordingly, the char generated in the gasifier 130 is not directly supplied to the boiler 110 but is stored in the storage tank 150 to enable flexible operation of the combined cycle power plant 100 .

Meanwhile, the combined cycle power generation system 100 may further include a supply unit 160 .

The supply unit 160 is connected to the storage tank 150 . The supply unit 160 allows the char stored in the storage tank 150 to be supplied to the boiler 110 .

Meanwhile, the combined cycle power generation system 100 may further include a control unit 170 .

The control unit 170 controls the supply unit 160 to adjust the amount of char stored in the storage tank 150 to be supplied to the boiler 110 . Accordingly, the combined power generation system 100 can control the amount of power generated by the steam turbine unit 120 and the gas turbine 140 , and thus can have power generation control responsiveness.

Meanwhile, the combined cycle power generation system 100 may further include a syngas burner 111 .

The syngas burner 111 is provided in the boiler 110 to generate steam in the boiler 110 using the syngas discharged from the gasifier 130 .

Meanwhile, the combined cycle power generation system 100 may further include a syngas distribution unit 131 .

The syngas distribution unit 131 is connected to the outlet of the gasifier 130 . The syngas distribution unit 131 supplies syngas to the syngas burner 111 and is used as a fuel for starting the boiler 110 . Through this, it is possible to increase the syngas discharged from the gasifier 130 to the combustible temperature of char in the boiler 110 without a separate auxiliary fuel during operation of the combined cycle power generation system 100 . And when it is necessary to rapidly increase the load of the boiler 110, it can be used for the purpose of maintaining a constant temperature of the layer material. Through this, the initial start-up cost of the combined power generation system 100 can be reduced, which is economical.

Meanwhile, the combined cycle power generation system 100 may further include a steam supply unit 180 .

The steam supply unit 180 supplies the steam to the gasifier 130 . The syngas discharged by the pyrolysis and gasification reaction in the gasifier 130 is introduced into the syngas purification units 132a and 132b through the syngas distribution unit 131 . The synthesis gas purification units 132a and 132b purify hydrogen in the synthesis gas and store it in the hydrogen storage unit 133 .

Meanwhile, the combined cycle power generation system 100 may further include a control unit 170 .

The control unit 170 controls the water vapor supply unit 180 to control the supply of water vapor from the supply unit 180 to the gasifier 130 . By supplying water vapor to the gasifier 130 , it is possible to increase the hydrogen rate in the syngas discharged by the pyrolysis and gasification reaction in the gasifier 130 .

Meanwhile, the combined cycle power generation system 100 may further include a combined gas purification unit 132 .

The syngas purification unit 132 is connected to the discharge unit from which the syngas is discharged from the gasifier 130 . The syngas purification unit 132 may receive the syngas discharged from the gasifier 130 from the syngas distribution unit to obtain hydrogen in the syngas.

Meanwhile, the combined cycle power generation system 100 may further include a hydrogen gas turbine 140 .

The hydrogen gas turbine 140 is driven using hydrogen stored in the hydrogen storage unit 133 . The hydrogen gas turbine 140 generates electric power by driving a generator. According to the combined power generation system 100 having such a configuration, it is possible to implement ultra-clean power generation that does not require the capture and storage of carbon dioxide by generating electricity using hydrogen.

On the other hand, the combined cycle power system 100 may further include a heat exchanger 141 and a direct contact heat exchanger (DCC) 142 for heating the steam of the steam turbine 120 using the heat of the gas turbine 140 . can In addition, the combined cycle power system 100 may further include a CPU 143 and a recirculation blower 115 . In addition, the exhaust gas discharged through the combustion reaction in the boiler 110 may be stored in the carbon dioxide storage unit 144 through the recirculation exhaust gas control valve 114 .

Hereinafter, a first operation mode and a general operation mode of the combined cycle power generation system 100 will be described with reference to FIG. 3 .

3 is a flowchart illustrating a first operation mode and a normal operation mode requiring an increase in the amount of power generation in the combined cycle power generation system 100 illustrated in FIG. 2 .

Referring to FIG. 3 , when an increase in the amount of power generation is required, the combined power generation system 100 is operated in the first operation mode. In the first operation mode, when power generation using the gas turbine 140 has high load responsiveness and an adjustment of the power generation load is urgently needed, the gas turbine 140 increases the amount of power generation by increasing the production of syngas in the gasifier 130 . make it And char (char) generated by the pyrolysis and gasification reaction in the gasifier 130 is stored in the storage tank (150). Contrary to this, when the adjustment of the power generation load is not large in the normal operation mode, the char stored in the storage tank 150 may be supplied to the boiler 110 to operate. In addition, electricity can be produced using the steam turbine 120 by using char stored in the storage tank 150 as a fuel for the boiler 110 , thereby maximizing the economic feasibility.

Hereinafter, the second operation mode and the general operation mode of the combined cycle power generation system 100 will be described with reference to FIG. 4 .

4 is a flowchart illustrating a second operation mode and a normal operation mode requiring hydrogen production in the combined cycle power generation system 100 illustrated in FIG. 2 .

Referring to FIG. 4 , when hydrogen production is required, the combined cycle power generation system 100 is operated in the second operation mode. In the second operation mode, for example, during a time period in which renewable energy produces a lot of electricity, such as during the daytime, production and storage of hydrogen is required rather than electricity production. in this case. By reducing the operation of the boiler 110, the amount of power generated by the steam turbine 120 is reduced. In addition, rather than generating electricity using the gas turbine 140 , the synthesis gas discharged from the gasifier 130 is mainly produced by the synthesis gas purification units 132a and 132b to produce hydrogen and synthesis gas, and the gasifier 130 generates Char can be stored in the storage tank 150 to increase the utilization rate of the combined cycle power generation system 100 and secure operational economics. And in the time zone when renewable energy produces little electricity, for example, at night time, electricity using a gas turbine (including a hydrogen turbine) 140 using hydrogen and syngas that have been produced and stored in the hydrogen storage unit 133 . can be produced, maximizing economic efficiency.

The combined power generation system described above is not limited to the configuration and method of the embodiments described above, the embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

10: Conventional combined cycle power generation system
100: combined cycle system
11, 110: boiler
10a, 101: fuel supply device
10b, 102: air separation device (ASU)
10c, 10d, 103, 104: oxygen flow control valve
111: syngas burner
11a, 11b, 112, 113: exhaust gas flow control valve
11c, 114: recirculation flue gas control valve
11d, 115: recirculating blower
12, 120: steam turbine
13, 130: gasifier
131: syngas distribution device unit
13a, 13b, 132a, 132b: syngas purification unit
13c, 133: hydrogen storage unit
13d, 134: syngas control unit
13e, 135: combustor
14, 140: gas turbine, hydrogen gas turbine
14a, 141: heat exchanger
14b, 142: Direct Contact Heat Exchanger (DCC)
14c, 143: CPU
14d, 144: carbon dioxide storage unit
150: storage tank
160: supply unit
170: control unit
180: water vapor supply unit

Claims (11)

a boiler for generating steam by circulating the heat generated by the combustion so that the fuel can be completely burned in oxygen condition;
a steam turbine configured to be driven by receiving the steam generated by the boiler;
a gasifier configured to receive fossil fuel and high-temperature carbon dioxide generated from the boiler to generate and discharge syngas through thermal decomposition and gasification reaction;
a gas turbine configured to be driven by receiving the syngas generated from the gasifier; and
Combined power generation system including a storage tank formed to enable storage of char (char) generated by the pyrolysis and gasification reaction in the gasifier.
According to claim 1,
Combined power generation system further comprising a supply unit configured to control the load of the boiler by adjusting the amount of the char (char) supplied from the storage tank to the boiler.
3. The method of claim 2,
Combined power generation system, characterized in that it further comprises a control unit for controlling the supply unit to supply the char stored in the storage tank to the boiler so that the steam is generated in the boiler.
3. The method of claim 2,
The boiler, combined power generation system comprising a syngas burner configured to generate the steam by using the syngas discharged from the gasifier as a fuel.
5. The method of claim 4,
Complex characterized in that it further comprises a syngas distribution device for injecting the syngas generated in the gasifier into the syngas burner so that the syngas can be used to increase the temperature of the steam generated in the boiler. power generation system.
3. The method of claim 2,
Combined power generation system, characterized in that it further comprises a water vapor supply unit for supplying water vapor to the gasifier to increase the hydrogen yield of the synthesis gas generated in the gasifier.
7. The method of claim 6,
The combined cycle power generation system of claim 1, further comprising: a controller configured to supply the steam from the steam supply unit to the boiler to increase the temperature of the steam generated in the boiler by using the steam.
7. The method of claim 6,
Combined power generation system, characterized in that it is connected to the discharge part of the gasifier from which the syngas is discharged, and further comprises a syngas purification unit made to be obtained by purifying hydrogen of the syngas generated in the gasifier.
9. The method of claim 8,
Combined power generation system, characterized in that it further comprises a hydrogen gas turbine configured to drive a generator using the hydrogen generated in the synthesis gas purification unit.
3. The method of claim 2,
In the first operation mode in which an increase in power generation is required, the supply amount of the char supplied from the gas turbine to the boiler is reduced, and the synthesis gas is burned in the gasifier to increase the power generation amount of the gas turbine. Combined power generation system, characterized in that it further comprises a control unit made of.
9. The method of claim 8,
The synthesis gas purification unit has a hydrogen storage unit for storing the hydrogen,
In the second operation mode in which the production of hydrogen is required, a control unit for storing the hydrogen purified by the synthesis gas purification unit in the hydrogen storage unit and driving the hydrogen gas turbine using the hydrogen stored in the hydrogen storage unit; Combined power generation system, characterized in that it further comprises.

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