Air humidification cycle power generation system and method using coal as raw material

Abstract

The present invention provides an air humidification cycle power generation system and method using coal as raw material, comprising an internal carbon capture gasification unit and an air humidification cycle unit, wherein the fuel gas inlet of the air humidification cycle unit is connected to the fuel gas outlet of the internal carbon capture gasification unit; the present invention can replace traditional coal gasification, water-gas shift, desulfurization and decarbonization, air separation and other units by the internal carbon capture gasification unit, so that the coal gasification process is greatly simplified and the directional conversion of C and H elements is achieved in one step; by using the heat of the gas at the outlet of the internal carbon capture gasification unit to heat a part of the hot water for humidification, the humidified air output of the air humidification cycle can be further increased, and the system output power can be further improved; at the same time, the heating air required by the internal carbon capture gasification unit comes from the air humidification cycle unit, eliminating the need for a separate air compressor, and the required air enters the fuel gas generation unit after being heated by the heat exchange unit, reducing the energy consumption of the oxygen transmission process.

Description

Technical Field

[0001] The invention belongs to the field of coal power generation, and in particular relates to an air humidification cycle power generation system and method using coal as raw material. Background Art

[0002] Coal is the cornerstone of my country's energy, providing economical and stable energy for economic and social development. At the same time, my country's energy development faces severe environmental challenges. Pollutants emitted by coal combustion are the main source of China's atmospheric pollutants. CO2 emissions are the main factor in global climate change. Resource and environmental constraints determine that a new generation of efficient and clean coal power generation technology and coal conversion technology are major needs of my country's energy system in the future.

[0003] The air humidification cycle is a representative advanced power cycle. It uses water injection, steam injection or humidifier to recover waste heat in the gas turbine cycle, and can develop new cycles suitable for different application backgrounds and scales. It can be integrated with syngas and its preparation process, and recover different grades of heat outside the gas turbine cycle by humidifying air or fuel with water, which can effectively expand the air humidification gas turbine cycle. Their characteristics are: improving efficiency and specific work, reducing costs and emissions, and improving flexibility.

[0004] After coal is gasified into raw synthesis gas and the synthesis gas is subjected to dust removal and purification, the clean synthesis gas can be used as the raw gas for the air humidification cycle. Compared with the conventional coal-fired power system or the integrated coal gasification combined cycle, the air humidification cycle with coal as raw material has a greater potential for improving efficiency through cycle innovation.

[0005] 1. The treatment process of syngas after coal gasification includes many processes such as coal gas purification, water-gas shift, desulfurization, decarbonization, heat recovery, etc. The process is long and energy-intensive, especially the decarbonization process, which consumes a lot of energy;

[0006] 2. Due to the demand for air humidification, the air humidification cycle requires a large amount of medium and low temperature heat to produce humidification hot water. If it only relies on the heat of the exhaust gas of the gas turbine, the air humidification capacity will be limited, thereby limiting the system power and efficiency; Summary of the invention

[0007] The purpose of the present invention is to provide an air humidification cycle power generation system and method using coal as raw material, which solves the defect of low efficiency of the existing zero-emission air humidification cycle power generation system using coal as raw material.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] The present invention provides an air humidification cycle power generation system using coal as raw material, comprising an internal carbon capture gasification unit and an air humidification cycle unit, wherein the fuel gas inlet of the air humidification cycle unit is connected to the fuel gas outlet of the internal carbon capture gasification unit;

[0010] The internal carbon capture gasification unit comprises a fuel gas generation unit and a heat exchange unit, wherein the fuel gas generation unit is provided with a gas inlet, a solid inlet, a fuel gas outlet and a mixed gas outlet, the gas inlet is connected to the water vapor outlet of the heat exchange unit, the mixed gas outlet is connected to the gas inlet of the heat exchange unit; the fuel gas outlet is connected to the fuel gas inlet of the air humidification circulation unit;

[0011] The air humidification unit comprises:

[0012] a superheated steam generating unit for generating superheated steam;

[0013] A power generation unit for generating electricity using superheated steam.

[0014] Preferably, the fuel gas generation unit comprises a gasification reactor, a regeneration reactor and an oxidation reactor, wherein the gasification reactor is provided with a solid inlet and a water vapor inlet, the water vapor inlet is connected to the water vapor outlet of the heat exchange unit; the hydrogen-rich fuel gas outlet on the gasification reactor is connected to the fuel gas inlet of the air humidification circulation unit;

[0015] The solid outlet of the gasification reactor is connected to the solid inlet of the regeneration reactor, and the water vapor inlet of the regeneration reactor is connected to the water vapor outlet of the heat exchange unit;

[0016] The mixed gas outlet of the regeneration reactor is connected to the high-temperature side gas inlet of the heat exchange unit;

[0017] The oxidation reactor is provided with a solid inlet and an air inlet, wherein the air inlet is connected to the heating air outlet of the heat exchange unit; the solid outlet of the oxidation reactor is connected to the solid inlet of the regeneration reactor, and the nitrogen-enriched air outlet of the oxidation reactor is connected to the fuel gas inlet of the air humidification circulation unit.

[0018] Preferably, the heat exchange unit comprises a high-temperature heat exchanger, a waste boiler and a low-temperature heat exchanger, wherein the mixed gas outlet of the fuel gas generation unit is connected to the high-temperature side gas inlet of the high-temperature heat exchanger, and the heated air outlet of the high-temperature heat exchanger is connected to the air inlet of the fuel gas generation unit;

[0019] The high-temperature side gas outlet of the high-temperature heat exchanger is connected to the high-temperature side gas inlet of the low-temperature heat exchanger through the waste boiler;

[0020] The air inlet of the high temperature heat exchanger is connected to the air outlet of the air humidification circulation unit;

[0021] The low-temperature side gas outlet of the low-temperature heat exchanger is divided into two paths, one of which is connected to the water vapor inlet of the fuel gas generation unit through the waste boiler, and the other is connected to the gas inlet of the air humidification circulation unit.

[0022] Preferably, the superheated steam generating unit comprises a primary compressor, a secondary compressor, an intercooler, a humidifier, a heat exchanger, a regenerator and an evaporator, wherein the primary compressor is provided with an air inlet and a compressed gas outlet, the compressed gas outlet is connected to the gas inlet of the secondary compressor through the intercooler, the compressed gas outlet of the secondary compressor is divided into two paths, one path is connected to the internal carbon capture gasification unit, and the other path is connected to the gas inlet at the bottom of the humidifier through the heat exchanger;

[0023] The wet air outlet of the humidifier is connected to the power generation unit through the regenerator;

[0024] The smoke exhaust port of the power generation unit is connected to the evaporator through a heat regenerator, and the superheated steam outlet of the evaporator is connected to the power generation unit.

[0025] Preferably, the water outlet at the bottom end of the humidifier is connected to the water inlets of the heat exchanger, intercooler and economizer respectively; the heating water outlets of the economizer, intercooler, heat exchanger and internal carbon capture gasification unit are all connected to the water inlet of the humidifier.

[0026] Preferably, the power generation unit comprises a turbine and a combustion chamber, wherein the superheated steam inlet of the turbine is respectively connected to the superheated steam outlet of the combustion chamber and the superheated steam generating unit; and the fuel gas inlet of the combustion chamber is respectively connected to the fuel gas outlet of the internal carbon capture gasification unit and the heated wet air outlet of the superheated steam generating unit.

[0027] An air humidification cycle power generation method using coal as raw material comprises the following steps:

[0028] Using water vapor, coal and metal oxygen carrier to generate hydrogen-rich fuel gas and heating gas, and using the generated hydrogen-rich fuel gas to generate high-temperature flue gas;

[0029] Air and heated gas are used to generate superheated steam, and superheated steam and high-temperature flue gas are used to generate electricity.

[0030] Preferably, coal, water vapor and a metal oxygen carrier from an oxidation reactor are fed into a gasification reactor for reaction to generate hydrogen-rich fuel gas, CaCO feedstock, coke and ash, wherein the hydrogen-rich fuel gas is fed into a combustion chamber for combustion;

[0031] The CaCO raw material, coke and ash are sent to the regeneration reactor to react with water vapor and the metal oxygen carrier from the oxidation reactor; a mixed gas and an oxygen carrier metal are generated, wherein the mixed gas is sent to a high-temperature heat exchanger to recover heat, and then the cooled mixed gas is sent to a waste boiler for cooling, and the cooled mixed gas is sent to a low-temperature heat exchanger for heating humidified hot water; a part of the heated humidified hot water is converted into water vapor through heat exchange in the waste boiler and sent to the gasification reactor and the regeneration reactor for reaction; the other part is sent to the air humidification circulation unit;

[0032] The oxygen carrier metal is sent into an oxidation reactor to react with the air heated by a high-temperature heat exchanger to generate metal oxygen carrier and nitrogen-rich air; the nitrogen-rich air is sent into a combustion chamber for combustion; and the generated metal oxygen carrier is sent into a regeneration reactor for reaction.

[0033] Preferably, the first-stage compressor draws air from the atmosphere for compression, and the generated compressed gas enters the intercooler for cooling and is then transported to the second-stage compressor for further compression;

[0034] Part of the compressed gas outlet of the secondary compressor enters the low-temperature side gas inlet of the high-temperature heat exchanger, and is sent to the oxidation reactor after further heating; the remaining gas enters the hot side of the heat exchanger, and enters the gas inlet at the bottom of the humidifier after heat recovery. The humidified wet air enters the low-temperature side of the regenerator, and enters the combustion chamber after heating to burn with the fuel to form high-temperature flue gas;

[0035] The high-temperature flue gas at the combustion chamber outlet enters the turbine to do work, driving the generator to generate electricity;

[0036] The exhaust gas of the turbine first passes through the high temperature side of the regenerator to heat the wet air from the humidifier, and then enters the evaporator to generate superheated steam to supply the turbine to do work. The exhaust steam generated is supplied to the regeneration reactor and gasification reactor of the internal carbon capture gasification unit.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention provides an air humidification cycle power generation system and method using coal as raw material, which can replace traditional coal gasification, water-gas shift, desulfurization and decarbonization, air separation and other units through an internal carbon capture gasification unit, thereby greatly simplifying the coal gasification process and realizing the directional conversion of C and H elements in one step; by utilizing the heat of the gas at the outlet of the internal carbon capture gasification unit to heat a part of the hot water for humidification, the humidified air output of the air humidification cycle can be further increased, and the system output power can be further improved; at the same time, the heated air required by the internal carbon capture gasification unit comes from the air humidification cycle unit, eliminating the need for a separate air compressor, and the required air enters the fuel gas generation unit after being heated by the heat exchange unit, thereby reducing the energy consumption of the oxygen transmission process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a system structure diagram of the present invention;

[0040] Among them, 1, gasification reactor 2, regeneration reactor 3, oxidation reactor 4, first-stage compressor 5, second-stage compressor 6, combustion chamber 7, turbine 8, intercooler 9, humidifier 10, high-temperature heat exchanger 11, heat exchanger 12, regenerator 13, evaporator 14, economizer 15, waste boiler 16, low-temperature heat exchanger. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0042] like Figure 1 As shown, the present invention provides an air humidification cycle power generation system using coal as raw material, comprising an internal carbon capture gasification unit and an air humidification cycle unit, wherein the fuel gas of the air humidification cycle unit is provided by the internal carbon capture gasification unit.

[0043] The intrinsic carbon capture gasification process uses water vapor as the gasification agent and achieves the purpose of capturing CO2 during the gasification process by introducing a CO2 acceptor (CaO).

[0044] The internal carbon capture gasification unit includes a gasification reactor 1, a regeneration reactor 2, an oxidation reactor 3, a high-temperature heat exchanger 10, a waste boiler 15 and a low-temperature heat exchanger 16, wherein the gasification reactor 1 is used for coal gasification and CO2 solidification; the regeneration reactor 2 is used for the regeneration of the CO2 acceptor and the regeneration of the oxygen carrier metal (Me); and the oxidation reactor 3 is used for the oxidation of the oxygen carrier.

[0045] The gasification reactor 1 is provided with a coal inlet, a water vapor inlet and a CaO raw material inlet, wherein the CaO raw material inlet is connected to the CaO raw material outlet provided on the regeneration reactor 2 .

[0046] The gasification reactor 1 is provided with a hydrogen-rich fuel gas outlet, a CaCO3 raw material outlet, a coke outlet and an ash outlet.

[0047] The regeneration reactor 2 is provided with a metal oxygen carrier inlet, a CaCO3 raw material inlet, a coke inlet, an ash inlet and a water vapor inlet.

[0048] The regeneration reactor 2 is provided with a mixed gas outlet, a CaO raw material outlet, an oxygen carrier metal outlet and an ash outlet, wherein the mixed gas outlet is connected to the high temperature side inlet of the high temperature heat exchanger 10, the high temperature side outlet of the high temperature heat exchanger 10 is connected to the inlet of the waste boiler 15, the outlet of the waste boiler 15 is connected to the high temperature side inlet of the low temperature heat exchanger 16, the high temperature side outlet of the low temperature heat exchanger 16 is a gas outlet, the low temperature side inlet of the low temperature heat exchanger 16 is a water replenishment inlet, and the low temperature side outlet of the low temperature heat exchanger 16 is divided into two paths, one path is connected to the heating and humidification hot water inlet of the waste boiler 15, and the other path is connected to the heating and humidification hot water inlets of the humidifier 9 and the evaporator 13 respectively.

[0049] The water vapor outlet of the waste boiler 15 is connected to the air inlet of the gasification reactor 1 and the air inlet of the regeneration reactor 2 respectively.

[0050] The heated air outlet of the high-temperature heat exchanger 10 is connected to the air inlet of the oxidation reactor 3 .

[0051] The oxidation reactor 3 is provided with a metal oxygen carrier outlet, an air inlet, and a nitrogen-enriched air outlet, wherein the air inlet is connected to the heating air outlet of the high-temperature heat exchanger 10; the nitrogen-enriched air outlet is connected to the air inlet of the combustion chamber; and the metal oxygen carrier outlet is connected to the metal oxygen carrier inlet of the gasification reactor 1.

[0052] Working process of internal carbon capture gasification unit:

[0053] Coal, water vapor and CaO from the regeneration reactor are sent to the gasification reactor 1 for reaction, and then the generated hydrogen-rich fuel gas is sent to the combustion chamber of the air humidification unit; the generated CaCO3 raw material, coke and ash are sent to the regeneration reactor 2 to react with the metal oxygen carrier and water vapor output from the oxidation reactor 3 to generate a mixed gas of CO2 and H2O, and the generated mixed gas of CO2 and H2O enters the waste boiler after heat recovery through the high-temperature heat exchanger, and enters the low-temperature heat exchanger after further cooling to heat the humidification hot water; a part of the heated humidification hot water is converted into water vapor through heat exchange in the waste boiler and sent to the gasification reactor 1 and the regeneration reactor 2 for reaction; the other part is sent to the humidifier 9 and the evaporator 13 respectively.

[0054] The oxygen carrier metal generated in the regeneration reactor 2 is sent to the oxidation reactor 3 to react with the air heated by the high-temperature heat exchanger to generate metal oxygen carrier and nitrogen-enriched air.

[0055] The ash generated in the regeneration reactor 2 is directly removed.

[0056] The nitrogen-rich air generated in the oxidation reactor 3 directly enters the combustion chamber of the air humidification circulation unit.

[0057] The air humidification cycle unit includes a first-stage compressor 4, a second-stage compressor 5, a combustion chamber 6, a turbine 7, an intercooler 8 and a humidifier 9, wherein the first-stage compressor 4 is provided with an air inlet and a compressed gas outlet, wherein the compressed gas outlet is connected to the second-stage compressor 5 through the intercooler 8.

[0058] The secondary compressor 5 is provided with a secondary compressed gas outlet, which is divided into two paths, one path is connected to the low temperature side inlet of the high temperature heat exchanger 10 , and the other path is connected to the hot side inlet of the heat exchanger 11 .

[0059] The low temperature side outlet of the high temperature heat exchanger 10 is connected to the air inlet of the oxidation reactor 3 .

[0060] The low-temperature side outlet of the heat exchanger 11 is connected to the gas inlet at the bottom end of the humidifier 9. The gas outlet of the humidifier 9 is divided into two paths, one of which is connected to the turbine 7 for cooling the turbine blades; the other is connected to the low-temperature side inlet of the regenerator 12. The low-temperature side outlet of the regenerator 12 is connected to the wet air inlet of the burner 6.

[0061] The high-temperature flue gas outlet of the burner 6 is connected to the turbine 7, and the turbine 7 is driven and connected to a generator.

[0062] The flue gas outlet of the turbine 7 is connected to the high temperature side inlet of the regenerator 12, the high temperature side outlet of the regenerator 12 is connected to the gas inlet of the evaporator 13, and the superheated steam outlet of the evaporator 13 is connected to the internal carbon capture gasification unit.

[0063] The flue gas outlet of the evaporator is connected to the flue gas inlet of the economizer 14 , and the economizer 14 is provided with a low-temperature flue gas outlet.

[0064] Working process of air humidification circulation unit:

[0065] The first-stage compressor 4 inhales air from the atmosphere, and the generated compressed gas enters the intercooler 8 for cooling and is then transported to the second-stage compressor 5 for further compression.

[0066] A part of the compressed gas outlet of the secondary compressor 5 enters the low-temperature side gas inlet of the high-temperature heat exchanger 10, and is sent to the oxidation reactor 3 after further heating; the remaining gas enters the hot side of the heat exchanger 11, and enters the gas inlet at the bottom end of the humidifier 9 after heat recovery. A part of the humidified wet air is sent to the turbine 7 for cooling the turbine blades, and the other part enters the low-temperature side of the regenerator 12, and enters the combustion chamber 6 after heating to burn with the fuel to form high-temperature flue gas.

[0067] The high-temperature flue gas at the outlet of the combustion chamber 6 enters the turbine 7 to perform work, driving the generator to generate electrical energy.

[0068] The exhaust gas of turbine 7 first passes through the high temperature side of the regenerator 12 to heat the moist air from the humidifier, and then enters the evaporator 13 to generate superheated steam to supply the turbine 7 to do work. The exhaust steam generated is then supplied to the regeneration reactor 2 and the gasification reactor 1 of the internal carbon capture gasification unit.

[0069] The flue gas after passing through the evaporator 13 enters the economizer 14 to transfer the low-temperature waste heat to the water from the humidifier 9, and is provided to the humidifier 9 as a part of the humidification water.

[0070] The water at the bottom of the humidifier 9 enters the intercooler 8 to exchange heat with the compressed air, and the heated water enters the humidifier 9 again.

[0071] The oxygen carrier Me and its oxide MeO are not limited to a certain metal and metal oxide, and all oxygen carriers used in chemical looping combustion are applicable to the present invention;

[0072] The CO2 absorber CaO can be replaced by alkali metal oxides such as MgO.

[0073] 1. Through the internal carbon capture gasification unit, the C and H components in the coal are converted in a targeted manner to directly produce hydrogen-rich fuel gas and high-concentration CO2, and by combining with oxygen carrier combustion, the air separation unit is omitted;

[0074] 2. Using the waste heat of CO2 from the regeneration reactor to heat a portion of the humidification hot water can increase the amount of hot water used for humidification, thereby further improving the degree of air humidification and increasing the output power.

[0075] 3. The air required by the oxidation reactor unit is extracted from the end of the secondary compressor, eliminating the need for a separate air compressor. The required air is heated by a high-temperature heat exchanger before entering the oxidation reactor, reducing the energy consumption of the oxygen transmission process.

[0076] The present invention can replace the traditional coal gasification, water-gas shift, desulfurization and decarbonization, air separation and other units by an internal carbon capture gasification unit including a gasification reactor, a regeneration reactor and an oxidation reactor, thereby greatly simplifying the coal gasification process and realizing the directional conversion of C and H elements in one step. By using the heat of the gas at the outlet of the regeneration reactor to heat a part of the hot water for humidification, the humidified air output of the air humidification cycle can be further increased, and the system output power can be further improved.

Claims

1. An air humidification cycle power generation system using coal as raw material, characterized in that: It comprises an internal carbon capture gasification unit and an air humidification circulation unit, wherein the fuel gas inlet of the air humidification circulation unit is connected to the fuel gas outlet of the internal carbon capture gasification unit; The internal carbon capture gasification unit comprises a fuel gas generation unit and a heat exchange unit, wherein the fuel gas generation unit is provided with a gas inlet, a solid inlet, a fuel gas outlet and a mixed gas outlet, the gas inlet is connected to the water vapor outlet of the heat exchange unit, the mixed gas outlet is connected to the gas inlet of the heat exchange unit; the fuel gas outlet is connected to the fuel gas inlet of the air humidification circulation unit; The air humidification unit comprises: a superheated steam generating unit for generating superheated steam; A power generation unit for generating electricity using superheated steam; The fuel gas generation unit comprises a gasification reactor (1), a regeneration reactor (2) and an oxidation reactor (3), wherein the gasification reactor (1) is provided with a solid inlet and a water vapor inlet, the water vapor inlet being connected to the water vapor outlet of the heat exchange unit; the hydrogen-rich fuel gas outlet on the gasification reactor (1) is connected to the fuel gas inlet of the air humidification circulation unit; The solid outlet of the gasification reactor (1) is connected to the solid inlet of the regeneration reactor (2), and the water vapor inlet of the regeneration reactor (2) is connected to the water vapor outlet of the heat exchange unit; The mixed gas outlet of the regeneration reactor (2) is connected to the high-temperature side gas inlet of the heat exchange unit; The oxidation reactor (3) is provided with a solid inlet and an air inlet, wherein the air inlet is connected to the heating air outlet of the heat exchange unit; the solid outlet of the oxidation reactor (3) is connected to the solid inlet of the regeneration reactor (2), and the nitrogen-enriched air outlet of the oxidation reactor (3) is connected to the fuel gas inlet of the air humidification circulation unit; The heat exchange unit comprises a high-temperature heat exchanger (10), a waste boiler (15) and a low-temperature heat exchanger (16), wherein the mixed gas outlet of the fuel gas generation unit is connected to the high-temperature side gas inlet of the high-temperature heat exchanger (10), and the heated air outlet of the high-temperature heat exchanger (10) is connected to the air inlet of the fuel gas generation unit; The high-temperature side gas outlet of the high-temperature heat exchanger (10) is connected to the high-temperature side gas inlet of the low-temperature heat exchanger (16) through the waste boiler; The air inlet of the high-temperature heat exchanger (10) is connected to the air outlet of the air humidification circulation unit; The low temperature side gas outlet of the low temperature heat exchanger (16) is divided into two paths, one path is connected to the water vapor inlet of the fuel gas generation unit through the waste boiler (15), and the other path is connected to the gas inlet of the air humidification circulation unit; The superheated steam generating unit comprises a first-stage compressor (4), a second-stage compressor (5), an intercooler (8), a humidifier (9), a heat exchanger (11), a regenerator (12) and an evaporator (13), wherein the first-stage compressor (4) is provided with an air inlet and a compressed gas outlet, the compressed gas outlet is connected to the gas inlet of the second-stage compressor (5) through the intercooler (8), the compressed gas outlet of the second-stage compressor (5) is divided into two paths, one path is connected to the internal carbon capture gasification unit, and the other path is connected to the gas inlet at the bottom end of the humidifier (9) through the heat exchanger (11); The wet air outlet of the humidifier (9) is connected to the power generation unit through the regenerator (12); The smoke exhaust port of the power generation unit is connected to the evaporator (13) via the regenerator (12), and the superheated steam outlet of the evaporator (13) is connected to the power generation unit.

2. The air humidification cycle power generation system using coal as raw material according to claim 1 is characterized in that: The water outlet at the bottom end of the humidifier (9) is respectively connected to the water inlets of the heat exchanger (11), the intercooler (8) and the economizer (14); the heating water outlets of the economizer (14), the intercooler (8), the heat exchanger (11) and the internal carbon capture gasification unit are all connected to the water inlet of the humidifier (9).

3. The air humidification cycle power generation system using coal as raw material according to claim 1 is characterized in that: The power generation unit comprises a turbine (7) and a combustion chamber (6), wherein the superheated steam inlet of the turbine (7) is respectively connected to the combustion chamber (6) and the superheated steam outlet of the superheated steam generation unit; and the fuel gas inlet of the combustion chamber (6) is respectively connected to the fuel gas outlet of the internal carbon capture gasification unit and the heated wet air outlet of the superheated steam generation unit.

4. A method for generating electricity by air humidification cycle using coal as raw material, characterized in that: The power generation system according to any one of claims 1 to 3 comprises the following steps: Using water vapor, coal and metal oxygen carrier to generate hydrogen-rich fuel gas and heating gas, and using the generated hydrogen-rich fuel gas to generate high-temperature flue gas; Use air and heated gas to generate superheated steam, and use superheated steam and high-temperature flue gas to generate electricity; Coal, steam and metal oxygen carrier from oxidation reactor (3) are fed into gasification reactor (1) for reaction to generate hydrogen-rich fuel gas, CaCO3 raw material, coke and ash, wherein the hydrogen-rich fuel gas is fed into combustion chamber (6) for combustion; The CaCO3 raw material, coke and ash are fed into a regeneration reactor (2) to react with water vapor and a metal oxygen carrier from an oxidation reactor (3); a mixed gas and an oxygen carrier metal are generated, wherein the mixed gas is fed into a high-temperature heat exchanger to recover heat, and then the cooled mixed gas is fed into a waste boiler (15) for cooling, and the cooled mixed gas is fed into a low-temperature heat exchanger (16) for heating humidified hot water; a portion of the heated humidified hot water is exchanged with the waste boiler (15) to form water vapor, which is fed into a gasification reactor (1) and a regeneration reactor (2) for reaction; and the other portion is fed into an air humidification circulation unit; The oxygen carrier metal is fed into the oxidation reactor (3) to react with the air heated by the high-temperature heat exchanger (10) to generate the metal oxygen carrier and nitrogen-enriched air; the nitrogen-enriched air is fed into the combustion chamber for combustion; the generated metal oxygen carrier is fed into the regeneration reactor (2) for reaction; The first-stage compressor (4) draws air from the atmosphere for compression, and the generated compressed gas enters the intercooler (8) for cooling and is then transported to the second-stage compressor (5) for further compression; A portion of the compressed gas at the outlet of the secondary compressor (5) enters the low-temperature side gas inlet of the high-temperature heat exchanger (10), is further heated and then sent to the oxidation reactor (3); the remaining gas enters the hot side of the heat exchanger (11), enters the gas inlet at the bottom end of the humidifier (9) after heat recovery, and the humidified air enters the low-temperature side of the regenerator (12), enters the combustion chamber (6) after being heated, and burns with the fuel to form high-temperature flue gas; The high-temperature flue gas at the outlet of the combustion chamber (6) enters the turbine (7) to perform work, thereby driving the generator to generate electrical energy; The exhaust gas of the turbine (7) first passes through the high temperature side of the regenerator (12) to heat the moist air from the humidifier, and then enters the evaporator (13) to generate superheated steam to supply the turbine (7) to do work. The exhaust steam generated is then supplied to the regeneration reactor (2) and the gasification reactor (1) of the internal carbon capture gasification unit.

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