# US 11,306,636 B2 · Plant and air pollution control method

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- Number: US 11,306,636 B2
- Document ID: US11306636B2
- Status: Granted
- Kind: B2
- Application number: 17/050,260
- Filed: 2019-04-19
- Published: 2021-03-18
- Granted: 2022-04-19
- Earliest claimed: 2018-04-24
- Assignees: Mitsubishi Heavy Industries Engineering, Ltd.
- Applicants: Mitsubishi Heavy Industries Engineering, Ltd.
- Inventors: Tatsuya Tsujiuchi; Takahito Yonekawa; Takashi Kamijo
- Web page: https://patentgrep.com/patent/US11306636B2

## CPC

- B01D 53/1475: {Removing carbon dioxide}
- F01N 3/18: characterised by methods of operation; Control
- F01K 17/02: for heating purposes, e.g. industrial, domestic (F01K17/06 takes precedence; domestic- or space-heating systems, e.g. central-heating systems, in general F24D1/00, F24D3/00, F24D9/00)
- F01K 23/10: with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence)
- F02C 1/10: Closed cycles
- F02C 3/00: Gas-turbine plants characterised by the use of combustion products as the working fluid (generated by intermittent combustion F02C5/00)
- B01D 53/343: {Heat recovery}
- B01D 53/62: Carbon oxides
- B01D 2252/204: Amines
- B01D 2257/504: Carbon dioxide
- B01D 2258/0283: Flue gases
- F05D 2220/32: in gas turbines
- F05D 2220/62: with energy recovery turbines
- Y02C 20/40: of CO2
- Y02E 20/16: Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- F01K: STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES (gas-turbine or jet-propulsion plants F02; nuclear power plants, engine arrangements therein G21D)
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A plant according to an embodiment includes a gas turbine; a heat recovery unit that includes a primary heat recovery steam generator in which a primary heat exchanging unit generates primary steam by exchanging heat that is the thermal energy of the flue gas from the gas turbine, and a secondary heat recovery steam generator that is installed independently from the primary heat exchanging unit, and in which a secondary heat exchanging unit generates secondary steam by exchanging heat that is the thermal energy of the flue gas partly having exchanged heat in the primary heat exchanging unit included in the primary heat recovery steam generator; a primary steam turbine; a CO2 recovery unit; and a first reboiler heat supply line.

## Claims

### Claim 1

A plant comprising:
a gas turbine;
a heat recovery unit that includes a primary heat recovery steam generator in which a primary heat exchanging unit generates primary steam by exchanging heat that is thermal energy of flue gas from the gas turbine, and a secondary heat recovery steam generator installed independently from the primary heat exchanging unit, and in which a secondary heat exchanging unit generates heated water by exchanging heat that is thermal energy of the flue gas having exchanged heat in the primary heat exchanging unit included in the primary heat recovery steam generator;
a primary steam turbine that is driven by the primary steam generated by the primary heat recovery steam generator;
a CO2 recovery unit that includes a reboiler for recovering CO2 contained in the flue gas discharged from the heat recovery unit;
a heated water supply line via which the heated water having exchanged heat in the secondary heat recovery steam generator is drawn off;
a heat exchanger device that transfers heat of the heated water drawn via the heated water supply line and generates secondary steam; and
a first reboiler heat supply line via which the secondary steam is guided to the reboiler.

### Claim 2 (depends on 1)

The plant according to claim 1, wherein
the secondary heat recovery steam generator includes a first secondary heat exchanging unit, and a second secondary heat exchanging unit provided on a downstream side of the first secondary heat exchanging unit,
the secondary steam having exchanged heat in the first secondary heat exchanging unit is guided to the reboiler via the first reboiler heat supply line, and
the heated water having exchanged heat in the second secondary heat exchanging unit is guided to a heat exchanger device via the heated water supply line so that the heat of the heated water is transferred and the secondary steam is generated, and the secondary steam is guided to the reboiler.

### Claim 3

A plant comprising:
a gas turbine;
a heat recovery unit that includes a primary heat recovery steam generator in which a primary heat exchanging unit generates primary steam by exchanging heat that is thermal energy of flue gas from the gas turbine, and a secondary heat recovery steam generator installed independently from the primary heat exchanging unit, and in which a secondary heat exchanging unit generates secondary steam by exchanging heat that is thermal energy of the flue gas having exchanged heat in the primary heat exchanging unit included in the primary heat recovery steam generator;
a primary steam turbine that is driven by the primary steam generated by the primary heat recovery steam generator;
a CO2 recovery unit that includes a reboiler for recovering CO2 contained in the flue gas discharged from the heat recovery unit; and
a first reboiler heat supply line via which the secondary steam generated by the secondary heat recovery steam generator is guided to the reboiler, wherein
the secondary heat recovery steam generator includes a first secondary heat exchanging unit, and a third secondary heat exchanging unit provided on an upstream side of the first secondary heat exchanging unit,
the secondary steam having exchanged heat in the first secondary heat exchanging unit is guided to the reboiler via the first reboiler heat supply line, and
the secondary steam having exchanged heat in the third secondary heat exchanging unit, and having a temperature higher than a temperature of the secondary steam having exchanged heat in the first secondary heat exchanging unit is guided into a steam turbine for driving a CO2 compressor.

### Claim 4 (depends on 1)

The plant according to claim 1, further A plant comprising:
a gas turbine;
a heat recovery unit that includes a primary heat recovery steam generator in which a primary heat exchanging unit generates primary steam by exchanging heat that is thermal energy of flue gas from the gas turbine, and a secondary heat recovery steam generator installed independently from the primary heat exchanging unit, and in which a secondary heat exchanging unit generates secondary steam by exchanging heat that is thermal energy of the flue gas having exchanged heat in the primary heat exchanging unit included in the primary heat recovery steam generator;
a primary steam turbine that is driven by the primary steam generated by the primary heat recovery steam generator;
a CO2 recovery unit that includes a reboiler for recovering CO2 contained in the flue gas discharged from the heat recovery unit;
a first reboiler heat supply line via which the secondary steam generated by the secondary heat recovery steam generator is guided to the reboiler;
a condensed water branching line that is branched from a condensed steam line for discharging condensed water from the reboiler;
an external heat source that is installed on the condensed water branching line, and that converts the condensed water to steam; and
a second reboiler heat supply line via which steam obtained in the external heat source is guided to the first reboiler heat supply line.

### Claim 5 (depends on 1)

The plant according to claim 1, further comprising a first duct burner that is installed on an upstream side of the primary heat recovery steam generator, and that heats the flue gas.

### Claim 6 (depends on 1)

The plant according to claim 1, further comprising:
the secondary heat recovery steam generator that is installed independently on a downstream side of the primary heat recovery steam generator, and that recovers thermal energy from the flue gas discharged after having exchanged heat in the primary heat recovery steam generator; and
a second duct burner that is installed on an upstream side of the secondary heat recovery steam generator, and that heats the flue gas having exchanged heat in the primary heat recovery steam generator.

### Claim 7

An air pollution control method for recovering CO2 from a gas turbine combined cycle power plant, the air pollution control method comprising:
a primary heat recovery step at which a primary heat exchanging unit exchanges heat that is thermal energy of flue gas from the gas turbine;
a secondary heat recovery step that is independent from the primary heat recovery step, and at which thermal energy of the flue gas having exchanged heat at the primary heat recovery step in the primary heat exchanging unit is recovered;
a CO2 recovery step that includes a reboiler for recovering CO2 contained in the flue gas discharged at the secondary heat recovery step;
a first reboiler heat supply step at which secondary steam having exchanged heat at the secondary heat recovery step is guided to the reboiler;
a condensed water branching step at which a part of condensed water from the reboiler is branched;
an external heat source step at which the condensed water branched is converted to steam by an external heat source; and
a second reboiler heat supply step at which the steam obtained in the external heat source step is guided to the secondary steam.