A supercritical CO2 combustion power generation system coupling solar energy and carbon utilization and storage

Abstract

This invention belongs to the technical field of boiler combustion power generation systems, specifically disclosing a supercritical CO2 combustion power generation system coupling solar energy and carbon utilization and storage. The system includes an oxygen production module, a supercritical CO2 power cycle oxygen-enriched combustion module, a solar photovoltaic power generation module, and a CO2 utilization and storage module. This system uses oxygen-enriched combustion of coal in a boiler as the core power generation unit, combined with solar photovoltaic power generation to form a multi-energy complementary power supply. Supercritical CO2 is used as the working fluid for circulating heat exchange, and a portion of the CO2 separated from the combustion flue gas is reused for oxygen-enriched combustion. Excess CO2 is catalytically converted into syngas with green hydrogen or compressed and stored. The beneficial effects of this invention are that it couples traditional coal oxygen-enriched combustion with solar power generation, improving energy utilization efficiency, reducing coal consumption, and decreasing pollutant emissions from the carbon capture source; simultaneously, the CO2 utilization and storage module achieves deep carbon emission reduction and resource utilization, powerfully promoting the synergistic complementarity of traditional thermal power and new energy sources, and transitioning towards near-zero carbon emissions.

Description

Technical Field

[0001] This invention relates to the field of boiler combustion power generation system technology, and in particular to a supercritical CO2 combustion power generation system that couples solar energy with carbon utilization and storage. Background Technology

[0002] Combining traditional coal with the photovoltaic industry is an effective solution and key link in achieving carbon neutrality. Solar energy fundamentally reduces carbon emissions and provides clean energy in the form of green hydrogen. As a new type of energy storage, it can solve the problem of the intermittency of renewable energy. The demonstration and application of traditional coal-solar thermal power generation is a key direction for the current development of diversified energy utilization, providing a new path for the coal-fired power generation industry to develop towards energy conservation and low carbon emissions. Several solar-coal complementary projects have been built or launched both domestically and internationally. However, some key issues in coal-solar thermal power generation still need to be resolved. Further research is needed on technologies such as the high-proportion coupling principle and design methods of solar thermal energy, system integration, control strategies, and flexible peak shaving of power plants.

[0003] Supercritical CO2-powered cycle coal-fired power generation systems possess advantages such as simple structure, compact components, and environmental friendliness. They are key technologies for improving system cycle efficiency and achieving energy conservation, and have significant scientific and practical value for the global coal-fired power generation industry in achieving carbon emission reduction targets. However, the establishment of novel industrial-scale supercritical CO2-powered cycle coal-fired power generation and solar power generation coupled systems remains a blank both domestically and internationally. The interaction laws and coupling methods between the two systems are still unclear.

[0004] Oxygen-enriched combustion technology is one of the most promising CO2 capture technologies for industrial application at present, and it has significant scientific and practical value for achieving carbon emission reduction targets in the global thermal power industry. Currently, the challenge facing the industrialization of oxygen-enriched combustion technology lies in how to reduce the energy consumption of air separation oxygen production units and further improve system economics. Developing oxygen-enriched combustion technology routes and adopting new oxygen production technologies are effective ways to reduce the energy consumption of carbon capture in oxygen-enriched combustion.

[0005] Carbon sequestration (CFS) technology is a key technology for achieving carbon neutrality. Combining traditional coal-fired power plants with CFS technologies to build a new industrial chain for thermal power presents an opportunity for transformation, upgrading, and a move towards a low-carbon future. Currently, research and development of coupled coal-fired power generation and CFS systems both domestically and internationally is mainly focused on laboratory exploration. Research primarily focuses on capturing CO2 after combustion and reusing it through novel chemical methods. Research on CFS systems focuses on the economic optimization of the system under given operating conditions, failing to consider the coupling relationship between the CFS system and upstream thermal power plants, and has not yet developed effective control methods and demonstration applications for the overall coal-fired power plant-CFS system. Summary of the Invention

[0006] In view of this, the present invention is mainly intended to achieve the following two objectives: The primary objective is to construct a supercritical CO2 oxy-fuel combustion power generation system that integrates oxygen production, supercritical CO2 oxy-fuel combustion power generation, solar photovoltaic utilization, and CO2 resource utilization and storage modules. This system aims to reduce energy consumption in the oxygen production and carbon capture processes, improve overall power generation efficiency and energy utilization, and simultaneously achieve multi-path diversion and closed-loop utilization of CO2 generated during combustion, avoiding direct emissions and achieving low-carbon and near-zero emission operation. The second objective is to improve system stability, power supply reliability, and overall economic efficiency through the coordinated operation of direct solar power and supercritical CO2 power cycle generation, providing an integrated technical solution for efficient and clean coal-fired power generation and carbon resource utilization. Therefore, a supercritical CO2 combustion power generation system that couples solar energy with carbon utilization and storage is proposed.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: This invention discloses a supercritical CO2 oxygen-enriched combustion power generation system that couples solar energy and carbon utilization and storage. The entire system is organically composed of four functional modules: an oxygen production module, a supercritical CO2 power cycle boiler oxygen-enriched combustion module, a solar photovoltaic power generation module, and a CO2 utilization and storage module.

[0008] The modules are interconnected through material flow, energy flow and information flow to form a comprehensive energy system that integrates high-efficiency power generation, clean combustion, renewable energy utilization, CO2 resource conversion and storage. Its core technical logic is defined by core formulas such as general thermodynamic relationships, energy balance, material distribution and conversion efficiency, to ensure the scientific nature and rigor of the technical solution.

[0009] The oxygen generation module mainly includes a cryogenic oxygen generation unit and a membrane separation oxygen generation unit. The two oxygen generation units operate in parallel or in series to provide high-purity O2 to the system, meeting the oxygen source supply required for oxygen-enriched combustion. Its core design follows the principle of comprehensive oxygen generation efficiency and oxygen source supply and demand balance.

[0010] The cryogenic oxygen generation unit uses air as raw material and utilizes the boiling point difference between oxygen and nitrogen in the air. Through multiple processes such as air compression, precooling, purification, distillation, low-temperature separation, product purification, and pressurization, it continuously produces high-purity oxygen, characterized by high oxygen purity, stable output, and suitability for large-scale oxygen supply. The membrane separation oxygen generation unit, based on the selective permeation characteristics of gas separation membranes, uses the pressure difference across the membrane to create a significant difference in the permeation rates of oxygen and nitrogen in the air. Oxygen preferentially permeates through the separation membrane to obtain oxygen-enriched air, offering advantages such as rapid start-up, compact structure, low energy consumption, and flexible operation.

[0011] This invention combines cryogenic oxygen production with membrane separation oxygen production to form a composite oxygen production system. This system allows for flexible adjustment of oxygen production and purity based on system load and operating conditions, significantly reducing energy consumption in the entire process of oxygen-enriched combustion and carbon capture using traditional single-method oxygen production. The oxygen production of the two oxygen production units follows a total oxygen supply and demand balance formula, ensuring a stable oxygen source for the system's oxygen-enriched combustion. .

[0012] in, The total oxygen production volume flow rate of the oxygen generation module (m³) 3 / h), The oxygen production volume flow rate (m³) of the cryogenic oxygen production unit 3 / h), The volumetric flow rate (m³) of pure oxygen in the oxygen-enriched air of a membrane separation oxygen production unit. 3 / h), The volumetric flow rate of pure oxygen required for oxygen-enriched combustion in a supercritical CO2 boiler (m³) 3 / h), Pure oxygen volumetric flow rate (m³) supplied to the water electrolysis unit 3 / h).

[0013] The overall energy efficiency of the oxygen generation module is quantified using the oxygen generation specific energy consumption formula, which characterizes the energy-saving advantage of the combined oxygen generation system compared to a single oxygen generation method: .

[0014] in, The overall specific energy consumption of the oxygen generation module (kWh / m³) 3 •O2), which is the energy consumption per unit of oxygen production in a cryogenic oxygen production unit (kWh / m³). 3 •O2), Energy consumption per unit of pure oxygen in a membrane separation oxygen production unit (kWh / m³) 3 •O2).

[0015] Preferably, the cryogenic oxygen production unit adopts a fully low-pressure plate heat exchanger type air separation equipment with an oxygen purity of not less than 99.6%, and the membrane separation oxygen production unit adopts a polyimide hollow fiber membrane separation module with an oxygen volume fraction of not less than 35% in the oxygen-enriched air. The operating pressures of the two units are controlled at 0.6~0.8MPa and 0.4~0.6MPa, respectively, to balance oxygen production efficiency and energy economy.

[0016] The oxygen produced by both oxygen generation units is delivered to the O2 / CO2 mixed gas storage tank to provide a stable oxygen source for subsequent oxygen-enriched combustion. The oxygen concentration in the mixed gas follows an ideal mixing relationship to ensure that the combustion atmosphere is controllable.

[0017] The supercritical CO2 power cycle boiler oxygen-enriched combustion module is the core power generation unit of the system, mainly including a feeder, an O2 / CO2 mixed gas storage tank, a supercritical CO2 power cycle boiler, a supercritical CO2 turbine, a generator, a flue gas purification device, a heat exchanger, and a compressor. Its core operation follows the thermodynamic cycle law of supercritical CO2 and the law of conservation of energy conversion.

[0018] Coal fuel, metered by a feeder, is fed into the combustion chamber of the supercritical CO2 power cycle boiler. Simultaneously, an O2 / CO2 mixed atmosphere is introduced into the furnace from an O2 / CO2 mixed gas storage tank, achieving oxygen-enriched combustion. The large amount of heat released during combustion is absorbed by the supercritical CO2 working fluid within the boiler's heating surfaces and cold walls, causing a significant increase in the working fluid's temperature and pressure, forming a high-temperature, high-pressure supercritical CO2 fluid. The heat transfer in this process follows the energy balance formula: .

[0019] in, The total heat flow (kW) released by the oxygen-enriched combustion of coal. Boiler heat exchange efficiency (dimensionless). The mass flow rate of supercritical CO2 working fluid is (kg / s). The specific enthalpy (kJ / kg) of CO2 working fluid at the boiler cold wall outlet. The specific enthalpy (kJ / kg) of CO2 working fluid at the boiler cold wall inlet.

[0020] High-temperature and high-pressure supercritical CO2 working fluid enters the supercritical CO2 turbine (6) and expands to do work, converting the thermal and pressure energy of the working fluid into mechanical energy, driving the turbine rotor to rotate at high speed. The turbine output power follows the turbine work formula: .

[0021] in, The mechanical power output (kW) of the supercritical CO2 turbine. The specific enthalpy (kJ / kg) of the CO2 working fluid imported into the turbine. The specific enthalpy (kJ / kg) of CO2 working fluid at the turbine outlet. Turbine internal efficiency (dimensionless).

[0022] The turbine spindle is connected to the generator, which further converts mechanical energy into electrical energy output. The generator's power output follows the electromechanical conversion efficiency formula, achieving high-efficiency power generation. .

[0023] in, This refers to the generator's output electrical power (kW). The electromechanical conversion efficiency of the generator (dimensionless).

[0024] The high-temperature flue gas generated by combustion enters the flue gas purification device, where it undergoes dust removal, desulfurization, denitrification, and gas separation to efficiently separate and purify the CO2 gas, resulting in a high-concentration CO2 stream. The CO2 separation efficiency is defined by the following formula, providing a raw material guarantee for subsequent CO2 recycling and storage: .

[0025] in, The CO2 separation efficiency (%) of the flue gas purification device. The mass flow rate (kg / s) of the pure CO2 obtained by separation. This represents the total CO2 mass flow rate (kg / s) in the boiler flue gas.

[0026] Preferably, the supercritical CO2 circulating boiler adopts a vertical water-cooled wall + spiral coil type supercritical CO2 circulating fluidized bed boiler, the supercritical CO2 turbine adopts an axial flow impulse multi-stage turbine, the generator adopts an air-cooled synchronous steam turbine generator, and the flue gas purification device adopts a bag filter + limestone-gypsum wet desulfurization + SCR denitrification + pressure swing adsorption CO2 capture integrated device.

[0027] Preferably, the supercritical CO2 power cycle boiler operates at a pressure of 20-30 MPa, with the working fluid outlet temperature controlled at 550-650℃, the turbine's internal efficiency not less than 92%, and the generator's electromechanical conversion efficiency not less than 98.5%, to ensure that the system's power generation efficiency is within the optimal range.

[0028] The solar photovoltaic power generation module provides clean and renewable energy to the system. It mainly includes solar electrothermal equipment and water electrolysis device. Its core operation follows the photovoltaic conversion law and the stoichiometric relationship of water electrolysis to realize the cascade conversion of light energy, electrical energy and chemical energy.

[0029] Solar-powered electrothermal equipment directly converts solar energy into direct current (DC) electricity using photovoltaic (PV) cell arrays. The total output power of the PV array follows the PV power calculation formula, reflecting the coupling relationship between light intensity and PV module performance. .

[0030] in, This represents the actual output power (kW) of the photovoltaic array. G represents the rated power of the photovoltaic array under standard test conditions (kW), and G represents the actual irradiance (W / m²). 2 ), Standard test light intensity (1000 W / m²) 2 ), The power temperature coefficient (K) of photovoltaic modules -1 ), This represents the actual operating temperature (K) of the photovoltaic cell. The standard test temperature is 298K.

[0031] Part of the generated electricity can be directly supplied to DC electrical equipment within the system, while the other part is converted into AC power through an inverter to provide a stable power source for the water electrolysis unit. The water electrolysis unit uses water as raw material and undergoes an electrolysis reaction driven by electricity, decomposing it to produce high-purity O2 and H2. This reaction follows Faraday's law of electrolysis, and the relationship between the mass flow rates of hydrogen and oxygen produced and the input electrical energy is as follows: , .

[0032] in, , The values ​​are the mass flow rates (kg / s) of hydrogen and oxygen produced by the water electrolysis unit, respectively; I is the operating current of the electrolyzer (A); and t is the operating time (s). The current efficiency (dimensionless) of the water electrolysis device. , The molar masses (kg / mol) of H2 and O2 are respectively, and F is the Faraday constant (96485C / mol).

[0033] The generated O2 serves as a supplementary oxygen source for oxygen-enriched combustion. Together with a portion of the CO2 separated from the oxygen-enriched combustion module of the supercritical CO2 power cycle boiler, it is sent to the O2 / CO2 mixed gas storage tank to adjust the oxygen concentration and circulating gas ratio in the combustion atmosphere, thereby improving combustion efficiency and reducing oxygen production energy consumption. The generated H2 serves as a high-grade reducing gas and is transported to the CO2 utilization and storage module as the feed gas for CO2 catalytic reforming.

[0034] Preferably, the solar electrothermal equipment uses monocrystalline silicon photovoltaic modules with a photoelectric conversion efficiency of not less than 22%, and the water electrolysis device uses a proton exchange membrane (PEM) electrolyzer with a current efficiency of not less than 90%, with the unit hydrogen production energy consumption controlled at 4.5~5.0 kWh / Nm³. 3 •H2, to improve the efficiency of solar energy utilization and the economics of hydrogen production.

[0035] The CO2 utilization and storage module realizes the resource conversion, recycling and geological storage of CO2 within the system. It mainly includes a CO2 / H2 catalytic reforming unit, a CO / CH4 syngas storage unit, a CO2 compression unit and a CO2 storage unit. Its core follows the stoichiometric relationship of catalytic reforming reaction and the balance law of CO2 utilization and storage throughout the entire process.

[0036] H2 from the solar photovoltaic power generation module and a portion of CO2 from the oxygen-enriched combustion module of the supercritical CO2 power cycle boiler are mixed in a set ratio and then fed into the CO2 / H2 catalytic reforming unit (4). Under the conditions of catalyst and suitable temperature and pressure, a catalytic reforming reaction occurs. The core reaction includes the reverse water-gas shift reaction and the methanation reaction. The material metering relationship of the total reaction follows: .

[0037] Where x and y are the number of moles of reactants CO2 and H2, and a, b, and c are the number of moles of products CO, CH4, and H2O, satisfying the law of conservation of elements (x = a + b, 2y = 2a + 4b + 2c).

[0038] CO2 is converted into CO / CH4 syngas through catalytic reforming. The resource conversion efficiency of the syngas is quantified by the following formula, reflecting the degree of effective utilization of CO2: .

[0039] in, The conversion rate of CO2 catalytic reforming is %. The molar flow rate of CO2 participating in the reaction is expressed in mol / s. The CO2 molar flow rate (mol / s) fed into the reforming unit.

[0040] The resulting syngas has high industrial utilization value. It is transported to the CO / CH4 syngas storage unit for storage and can be used as a chemical raw material, fuel gas, etc. for subsequent industrial applications, realizing the resource-efficient utilization of CO2.

[0041] Another portion of the CO2 in the system is pressurized to supercritical or transportable state by the CO2 compression unit, and then transported to the CO2 storage unit for long-term geological storage. The entire CO2 distribution process follows a material balance formula, ensuring a balance between the total amount of CO2 recycled, converted into resources, and stored, preventing direct CO2 emissions into the atmosphere, and achieving near-zero carbon emissions. .

[0042] in, The CO2 mass flow rate (kg / s) is the CO2 that is returned to the boiler cold wall to participate in the circulation. The CO2 mass flow rate (kg / s) fed into the catalytic reforming unit. The CO2 mass flow rate (kg / s) fed into the storage unit. The system CO2 leakage mass flow rate (kg / s, negligible) is given.

[0043] The flue gas produced by the combustion of a supercritical CO2 circulating boiler is separated and purified by a flue gas purification device to obtain high-purity CO2 gas. This portion of CO2 is diverted and circulated through multiple paths according to the system's energy balance, material balance, and operational requirements. The diversion ratio follows a normalized distribution formula to ensure the rationality of the flow distribution along each path. in, This refers to the volume fraction of CO2 fed into the O2 / CO2 mixed gas storage tank. The volume fraction of CO2 fed into the CO2 compression unit. This refers to the volume fraction of CO2 fed into the CO2 / H2 catalytic reforming unit. This represents the volume fraction of CO2 refluxed to the boiler cold wall.

[0044] Preferably, the CO2 gas separated by the flue gas purification device is sequentially transported to the O2 / CO2 mixed gas storage tank, the CO2 compression unit, the CO2 / H2 catalytic reforming unit, and the cold wall side of the supercritical CO2 power cycle boiler in volume fractions of 20%, 30%, 35%, and 15%, respectively, to achieve precise distribution and take into account the synergistic optimization of system power generation efficiency, CO2 resource utilization rate, and storage rate.

[0045] Preferably, the CO2 / H2 catalytic reforming unit adopts a fixed-bed catalytic reforming reactor, the reaction temperature is controlled at 300~400℃, the reaction pressure is controlled at 2.0~3.0MPa, a nickel-based or cobalt-based supported catalyst is used, the CO2 catalytic reforming conversion rate is not less than 85%, the CO2 compression unit (13) adopts a multi-stage centrifugal CO2 compressor to pressurize CO2 to 10~15MPa, and the CO2 storage unit (14) adopts a deep saline aquifer injection storage well group to meet the transportation requirements of geological storage.

[0046] The overall energy efficiency of the system described in this invention comprehensively considers fossil fuel consumption, renewable energy utilization, and CO2 emission reduction benefits. Defined by the system's total energy efficiency formula, it reflects the technical advantages of multi-module coupling. .

[0047] in, The overall energy efficiency of the system (dimensionless). This refers to the electrical power (kW) that the system connects to the power grid. The chemical energy flow rate (kW) of CO / CH4 synthesis gas. The heat input (kW) for coal combustion. The solar radiation energy flow (kW) received by the photovoltaic array.

[0048] Preferably, the system is equipped with a PLC centralized control cabinet and a variable frequency speed control system to uniformly control all electrical equipment.

[0049] Preferably, the direct solar power supply mode utilizes direct current (DC) generated by solar panels to directly supply certain DC loads. An inverter converts the DC power into alternating current (AC) for input into the power grid, continuously powering the water electrolysis unit, CO2 / H2 catalytic reforming unit, flue gas purification unit, and CO2 compression unit. Simultaneously, it outputs electrical energy to the grid, accounting for 50%, 5%, 5%, 5%, and 35% of the power supply, respectively. The supercritical CO2 power circulating boiler oxygen-enriched combustion power generation mode uses oxygen-enriched combustion of coal to increase the temperature and pressure of the supercritical CO2 working fluid in the cold wall. The high-temperature, high-pressure supercritical CO2 working fluid enters the supercritical CO2 turbine, converting its thermal energy into mechanical energy. The rotation of the supercritical CO2 turbine drives the generator, converting the mechanical energy into electrical energy for output, continuously powering the water electrolysis unit, CO2 / H2 catalytic reforming unit, flue gas purification unit, and CO2 compression unit. Simultaneously, it outputs electrical energy to the grid, accounting for 5%, 10%, 10%, 10%, and 65% of the power supply, respectively.

[0050] Compared with existing technologies, the beneficial effects of this invention are: Significantly improved power generation efficiency and greatly reduced energy consumption: The deep coupling of supercritical CO2 power cycle and oxygen-enriched combustion, combined with a multi-energy complementary power supply mode of solar energy, significantly improves the overall power generation efficiency of the system; the use of a combined oxygen production system of cryogenic oxygen production and membrane separation oxygen production effectively reduces the comprehensive energy consumption of the oxygen production module and the energy consumption of carbon capture in oxygen-enriched combustion; through closed-loop circulation of CO2 working fluid and waste heat recovery of flue gas, the energy utilization rate of the system is further improved, solving the technical pain points of low efficiency and high energy consumption of carbon capture and oxygen production in traditional coal-fired power generation.

[0051] The synergistic utilization and storage of CO2 resources have yielded significant low-carbon benefits: High-purity CO2 separated by the flue gas purification device is diverted in precise proportions for use in catalytic reforming to produce syngas for resource utilization, geological storage after compression, reflux into the system cycle, and supplementation of the oxygen-enriched combustion atmosphere. This achieves the synergistic advancement of CO2 resource utilization and storage, effectively reducing the overall CO2 emissions of the system and solving the greenhouse effect problem caused by direct CO2 emissions from traditional coal-fired power generation. This aligns with the development of low-carbon energy and the "dual carbon" target requirements.

[0052] Multi-energy synergy and complementarity significantly improve operational stability and flexibility: Solar photovoltaic power generation and supercritical CO2 oxygen-enriched combustion power generation are synergistically regulated in two modes, each undertaking corresponding power supply tasks under different light conditions to ensure continuous and stable power supply to the system; at the same time, the two oxygen production modules can flexibly adjust the oxygen production according to the combustion load, and the CO2 diversion ratio can be precisely controlled by relevant equipment to adapt to different operating conditions, solving the problems of poor stability of single-energy power generation and difficulty in system load adjustment.

[0053] The system boasts high integration, strong practicality, and adaptability to industrial needs: the four modules of oxygen production, power generation, CO2 utilization and storage all utilize mature industrial-grade equipment with standardized connection methods and clear operating parameters, allowing for direct implementation. The synthesized gas produced can be directly supplied to external chemical users, achieving the integration of "power generation-carbon utilization-chemical supply," expanding the system's industrial application scenarios, and enhancing the technology's economic efficiency and practicality.

[0054] Clean and environmentally friendly, with pollutant emissions meeting standards: The flue gas purification device integrates multiple functions such as dust removal, desulfurization, denitrification and CO2 separation, which can effectively control the emission of various pollutants. The clean utilization of solar energy replaces part of the consumption of fossil energy, further reducing pollutant and greenhouse gas emissions. It solves the technical shortcomings of excessive pollutant emissions in traditional coal-fired power generation and achieves synergy between clean combustion and efficient power generation. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the module structure of the supercritical CO2 oxygen-enriched combustion power generation system that couples solar energy and carbon utilization and storage according to the present invention. Figure 2 This is an overall flow diagram of the supercritical CO2 oxygen-enriched combustion power generation system that couples solar energy and carbon utilization and storage according to the present invention.

[0056] In the diagram: 1. Solar electric heating equipment; 2. Generator; 3. Water electrolysis device; 4. CO2 / H2 catalytic reforming device; 5. CO / CH4 syngas storage unit; 6. Supercritical CO2 turbine; 7. Feeder; 8. Cryogenic oxygen production unit; 9. Membrane separation oxygen production unit; 10. O2 / CO2 mixed gas storage tank; 11. Supercritical CO2 power cycle boiler; 12. Flue gas purification device; 13. CO2 compression unit; 14. CO2 storage unit; 15. Heat exchanger; 16. Compressor; 17. Power grid. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0058] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0060] This technical solution is as follows: Figure 1 As shown, Figure 1 The diagram shows the modular structure of the entire system, which is clearly divided into four major functional modules: oxygen production module (a), supercritical CO2 power cycle oxygen-enriched combustion module (b), solar photovoltaic power generation module (c), and CO2 utilization and storage module (d). The modules work together through dedicated material conveying pipelines and energy transmission lines. The specific linkage relationships are as follows: The oxygen generation module (a) and the solar photovoltaic power generation module (c) work together to supply oxygen to the supercritical CO2 power cycle oxygen-enriched combustion module (b), providing a stable oxygen source for the oxygen-enriched combustion reaction of the module. The CO2 produced by the solar photovoltaic power generation module (c) and the supercritical CO2 power cycle oxygen-enriched combustion module (b) is jointly transported to the CO2 utilization and storage module (d) for resource utilization and geological storage of CO2. The electrical energy generated by the supercritical CO2 power cycle oxygen-enriched combustion module (b) and the solar photovoltaic power generation module (c) is partly transmitted between the two modules to ensure their stable operation, partly sent to the CO2 utilization and storage module (d) to provide power for its operation, and the other part is sent to the power grid 17 to achieve grid-connected power supply.

[0061] For appendix Figure 1 The specific structure of each module is shown in the appendix. Figure 2 As shown, attached Figure 2The entire system flowchart is based on the core logic of "raw material input - reaction power generation - product processing - recycling", with all equipment units arranged in an orderly manner from left to right and from top to bottom; The oxygen generation module (a) is located in the middle of the left side, specifically including the cryogenic oxygen generation unit 8 and the membrane separation oxygen generation unit 9. The two units operate in parallel to provide a stable oxygen source for the system. Both are connected to the O2 / CO2 mixed gas storage tank 10 through material pipelines. The cryogenic oxygen production unit 8 uses a KDON-6000 / 8000 low-pressure plate heat exchanger type air separation equipment with an oxygen purity of not less than 99.6%. It uses ambient air as raw material and takes advantage of the boiling point difference between oxygen and nitrogen in the air. Through processes such as air compression, precooling, purification, distillation, low-temperature separation, product purification and pressurization, it continuously produces high-purity O2. It has the characteristics of high oxygen purity, stable output and suitability for large-scale oxygen supply. During operation, the air compressor of the cryogenic oxygen production unit 8 compresses ambient air to 0.7 MPa, cools it to 10°C via a precooler, then removes impurities such as moisture and carbon dioxide through molecular sieve purification, and finally cools it to -170°C via plate heat exchanger 15. It is then sent to a distillation column for cryogenic separation, ultimately producing O2 with a purity of 99.7%. After being boosted to 0.65 MPa by a booster compressor, it is transported through pipeline to the O2 / CO2 mixed gas storage tank 10, with an oxygen production volumetric flow rate of 5000 m³ / h. 3 / h; Among them, the membrane separation oxygen generation unit 9 adopts a polyimide hollow fiber membrane separation component of model MPF-1000. Based on the selective permeation characteristics of the gas separation membrane, the permeation rate of each component in the air is different when it passes through the membrane. Under the pressure difference, oxygen in the air preferentially passes through the membrane to obtain oxygen-enriched air. The oxygen volume fraction in the oxygen-enriched air is not less than 35%. It has the advantages of fast start-up, compact structure, low energy consumption and flexible operation.

[0062] During operation, the membrane separation oxygen generation unit 9 pressurizes ambient air to 0.5 MPa and introduces it into the polyimide hollow fiber membrane module. Driven by the pressure difference (0.3 MPa) across the membrane, oxygen preferentially permeates through the membrane module, producing oxygen-enriched air with an oxygen volume fraction of 38%, of which the pure oxygen volume flow rate is 1200 m³ / h. 3 / h, oxygen-enriched air is directly delivered to the O2 / CO2 mixed gas storage tank 10 and mixed with the high-purity O2 delivered by the cryogenic oxygen generation unit 8.

[0063] This technical solution combines cryogenic oxygen production with membrane separation oxygen production to form a composite oxygen production system. It can flexibly adjust the oxygen output and purity according to the system load and operating conditions, significantly reducing the energy consumption of traditional single oxygen production methods in the entire process of oxygen-enriched combustion and carbon capture, while ensuring a stable supply of oxygen. The total oxygen production volume flow rate of the two oxygen generation units follows the total oxygen supply and demand balance formula: in, The total oxygen production volume flow rate of the oxygen generation module (m³) 3 / h), The oxygen production volume flow rate (m³) of the cryogenic oxygen production unit 3 / h), The volumetric flow rate (m³) of pure oxygen in the oxygen-enriched air of a membrane separation oxygen production unit. 3 / h), The volumetric flow rate of pure oxygen required for oxygen-enriched combustion in a supercritical CO2 boiler (m³) 3 / h), Pure oxygen volumetric flow rate (m³) supplied to the water electrolysis unit 3 / h).

[0064] The overall energy efficiency of the oxygen generation module is quantified using the oxygen generation specific energy consumption formula, which characterizes the energy-saving advantage of the combined oxygen generation system compared to a single oxygen generation method: ; in, The overall specific energy consumption of the oxygen generation module (kWh / m³) 3 •O2), which is the energy consumption per unit of oxygen production in a cryogenic oxygen production unit (kWh / m³). 3 •O2), Energy consumption per unit of pure oxygen in a membrane separation oxygen production unit (kWh / m³) 3 •O2).

[0065] The calculated specific energy consumption of the oxygen generation module is 0.68 kWh / m³. 3 • O2, two new oxygen production technologies effectively reduce the energy consumption of carbon capture in oxygen-enriched combustion. Compared with a single cryogenic oxygen production unit 8, the energy consumption is reduced by 18%, achieving the energy-saving goal.

[0066] The supercritical CO2 power cycle oxygen-enriched combustion module (b) is the core power generation unit of the system, including a feeder 7, an O2 / CO2 mixed gas storage tank 10, a supercritical CO2 power cycle boiler 11, a supercritical CO2 turbine 6, a generator 2, a flue gas purification device 12, a heat exchanger 15, and a compressor 16. The equipment is connected in sequence according to the process flow direction, and its core operation follows the thermodynamic cycle law of supercritical CO2 and the law of conservation of energy conversion.

[0067] Among them, the supercritical CO2 power circulating boiler 11 adopts a 600MW vertical water-cooled wall + spiral coil type supercritical CO2 circulating fluidized bed boiler. The supercritical CO2 turbine 6 adopts the HT-600-SCO2 axial flow impulse multi-stage turbine. Generator 2 is an air-cooled synchronous steam turbine generator of model QF-300-2; The flue gas purification device 12 adopts an integrated device with model EP-2000+FGD-1500+SCR-1800+PSA-CO2, which combines bag filter dust collection, limestone-gypsum wet desulfurization, SCR denitrification, and pressure swing adsorption CO2 capture. Heat exchanger 15 is a shell-and-tube heat exchanger of model F-1000; The compressor 16 is a centrifugal CO2 compressor of model C-800; The feeder 7 is a spiral quantitative feeder of model LS-500.

[0068] Among them, the supercritical CO2 power cycle boiler 11, the supercritical CO2 turbine 6, and the generator 2 are the main power generation units. The supercritical CO2 power cycle boiler 11 is connected to the supercritical CO2 turbine 6, the supercritical CO2 turbine 6 is rigidly connected to the generator 2, and the output end of the generator 2 is connected to the power grid 17. The operating pressure of the supercritical CO2 power cycle boiler 11 is controlled at 20~30MPa, the working fluid outlet temperature is controlled at 550~650℃, the internal efficiency of the supercritical CO2 turbine 6 is not less than 92%, and the electromechanical conversion efficiency of the generator 2 is not less than 98.5%, so as to ensure that the power generation efficiency of the system is in the optimal range.

[0069] The input end of the supercritical CO2 power cycle boiler 11 is connected to the feeder 7 to transport the burning bituminous coal; The input end of the supercritical CO2 power cycle boiler 11 is connected to the O2 / CO2 mixed gas storage tank 10 to transport O2 / CO2; The flue gas output end of the supercritical CO2 power cycle boiler 11 is connected to the flue gas purification device 12 through a flue gas conveying pipeline. The output end of the flue gas purification device 12 is provided with four outlet pipelines, as follows: ① One outlet is connected to the O2 / CO2 mixed gas storage tank 10; ② The second outlet is connected in sequence to the heat exchanger 15, compressor 16, and supercritical CO2 power cycle boiler 11, and finally flows back to the cold wall of supercritical CO2 power cycle boiler 11 to form a closed loop. ③ The other two outlets are connected to the CO2 utilization and storage module (d) for storage and reuse; During power generation, the screw feeder 7 meteres bituminous coal (calorific value 29308 kJ / kg) at a flow rate of 120 t / h and feeds it into the combustion chamber of the supercritical CO2 power cycle boiler 11; the mixed atmosphere (30% O2 volume fraction and 70% CO2 volume fraction) in the O2 / CO2 mixed gas storage tank 10 is fed at a rate of 28000 m³ / h. 3A flow rate of / h is introduced into the furnace of the supercritical CO2 circulating boiler 11, where it undergoes an oxygen-enriched combustion reaction with the bituminous coal. The combustion temperature is controlled at 1200℃. The large amount of heat released during combustion is absorbed by the supercritical CO2 working fluid in the cold walls and heated surfaces of the supercritical CO2 circulating boiler 11, causing a significant increase in the temperature and pressure of the working fluid, forming a high-temperature, high-pressure supercritical CO2 fluid, which follows the energy balance formula: in The total heat flow (kW) released by the oxygen-enriched combustion of coal is specifically 1,000,000 kW. The boiler heat exchange efficiency (dimensionless) is specifically 92%. The supercritical CO2 working fluid mass flow rate (kg / s) is specifically 800 kg / s. The specific enthalpy (kJ / kg) of the CO2 working fluid at the boiler cold wall outlet is 1200 kJ / kg. The specific enthalpy (kJ / kg) of the CO2 working fluid at the boiler cold wall inlet is 300 kJ / kg, which ultimately heats the supercritical CO2 working fluid to a high temperature and high pressure state of 600℃ and 25 MPa.

[0070] High-temperature and high-pressure supercritical CO2 working fluid enters the axial-flow impulse multi-stage supercritical CO2 turbine 6 through pipelines. Expansion and work convert the thermal and pressure energy of the working fluid into mechanical energy, driving the turbine rotor to rotate at a high speed of 3000 r / min. The turbine output power follows the turbine work formula: , in The mechanical power output (kW) of the supercritical CO2 turbine. The specific enthalpy (kJ / kg) of the CO2 working fluid at the turbine inlet is 1200 kJ / kg. The specific enthalpy (kJ / kg) of the CO2 working fluid at the turbine outlet is 700 kJ / kg. The internal efficiency of the turbine (dimensionless) is 93%, and the output mechanical power of the supercritical CO2 turbine 6 is 372,000 kW. The main shaft of the supercritical CO2 turbine 6 is rigidly connected to the generator 2 of the air-cooled synchronous steam turbine, converting mechanical energy into electrical energy, following the electromechanical conversion efficiency formula: , in, The output power (kW) of generator 2. The electromechanical conversion efficiency (dimensionless) of generator 2 is 99%, and the output power of generator 2 is 368,280 kW. Part of it is used to power various electrical equipment in the system, specifically to continuously power the water electrolysis device 3, CO2 / H2 catalytic reforming device 4, flue gas purification device 9, and CO2 compression unit 10. The other part is connected to the power grid 17 through the transmission line, with a grid-connected power of 280,000 kW. The power supply ratios are 5%, 10%, 10%, 10%, and 65%, respectively.

[0071] During flue gas treatment operation, the high-temperature flue gas (temperature 1300℃, flow rate 180000 m³ / h) generated by the supercritical CO2 power cycle boiler 11 is treated. 3 The flue gas, passing through a pipeline, enters the flue gas purification unit 12 and sequentially undergoes bag filter dust collection (dust removal efficiency 99.9%), limestone-gypsum wet desulfurization (desulfurization efficiency 98.5%), and SCR denitrification (denitrification efficiency 95%) to remove pollutants such as dust, SO2, and NOx from the flue gas. Subsequently, CO2 is separated and purified by the pressure swing adsorption unit to obtain a high-concentration CO2 gas stream. The CO2 separation efficiency is defined by the following formula, providing a raw material guarantee for subsequent CO2 recycling and storage, following the CO2 separation efficiency formula: , in, The CO2 separation efficiency (%) of the flue gas purification device. The mass flow rate (kg / s) of the separated pure CO2 is specifically 150 kg / s. The total CO2 mass flow rate in the boiler flue gas is 160 kg / s. The calculated CO2 separation efficiency is 93.75%, and a high-concentration CO2 gas flow with a purity of 99.5% is finally obtained.

[0072] The separated high-purity CO2 is diverted through multiple paths. This portion of CO2 is diverted and circulated through multiple paths based on system energy balance, material balance, and operational requirements. The diversion ratio follows a normalized distribution formula to ensure the rationality of flow allocation in each path. , The specific diversion ratio is calculated based on volume fraction: The CO2 volume fraction fed into the O2 / CO2 mixed gas storage tank is specifically 20% (30kg / s). It is delivered to the O2 / CO2 mixed gas storage tank 10 and mixed with the O2 delivered by the oxygen generation module to adjust the mixed atmosphere ratio. The volume fraction of CO2 fed into the CO2 compression unit is specifically 30% (45 kg / s) delivered to the CO2 compression unit (CO2 utilization and storage module (d)). The volume fraction of CO2 fed into the CO2 / H2 catalytic reforming unit is specifically 35% (52.5 kg / s) and delivered to the CO2 / H2 catalytic reforming unit (CO2 utilization and storage module (d)). The CO2 volume fraction returned to the boiler cold wall is specifically 15% (22.5 kg / s). After being heated by heat exchanger 15 (from 80℃ to 300℃) and pressurized by compressor 16 (from 0.1 MPa to 25 MPa), it forms supercritical CO2, which is then returned to the cold wall of supercritical CO2 power cycle boiler 11 to continue participating in the heat exchange cycle, thus realizing the closed-loop utilization of CO2 working fluid.

[0073] This enables precise allocation, taking into account the synergistic optimization of system power generation efficiency, CO2 resource utilization rate, and storage rate.

[0074] The main body of the solar photovoltaic power generation module (c) is the solar electrothermal equipment 1, which provides clean and renewable energy to the system. Its core operation follows the photovoltaic conversion law and the stoichiometric relationship of water electrolysis, realizing the cascade conversion of light energy, electrical energy and chemical energy. It is another power generation unit in this system. The equipment selection and operating parameters are as follows: Solar electric thermal equipment 1 uses SM-72-550 monocrystalline silicon photovoltaic modules, with a total installed capacity of 100MW and a laying area of ​​180,000m². 2 The photovoltaic modules are arranged in a matrix and equipped with a tracking system, which can automatically adjust according to the angle of sunlight to improve photoelectric conversion efficiency. During operation, under standard lighting conditions (light intensity 1000W / m²), 2 (Ambient temperature 25℃) The photoelectric conversion efficiency of the monocrystalline silicon photovoltaic module is 23%. Solar electrothermal equipment 1 directly converts solar energy into DC power. The total output power of the photovoltaic array follows the photovoltaic power calculation formula, reflecting the coupling relationship between light intensity and photovoltaic module performance. The actual output power of the photovoltaic array follows the photovoltaic power calculation formula: , in, This represents the actual output power (kW) of the photovoltaic array. The rated power of the photovoltaic array (kW) under standard test conditions is 100,000 kW, and G is the actual irradiance (W / m²). 2 Specifically, 1000W / m 2 , The standard test light intensity is 1000 W / m². 2 , The power temperature coefficient (K) of photovoltaic modules -1 Specifically, it is 0.004K. -1 , This refers to the actual operating temperature (K) of the photovoltaic cell, specifically 303K. The standard test temperature is 298K.

[0075] The actual output power of the photovoltaic array is 98,000 kW; part of the DC power produced is directly supplied to DC power equipment in the system (such as solenoid valves and sensors), and another part is converted into AC power through an inverter to provide stable power to the proton exchange membrane electrolyzer with a power supply of 80,000 kW. The last part is connected to the power grid through the transmission line 17.

[0076] Secondly, the solar photovoltaic power generation module (c) also includes a water electrolysis device 3, which uses a PEM-500 proton exchange membrane PEM electrolyzer, with a total of 5 sets installed and operating in parallel.

[0077] The water electrolysis device 3 uses deionized water as raw material and undergoes a water electrolysis reaction driven by electricity, following Faraday's law of electrolysis, to decompose and produce high-purity O2 and H2. The relationship between the mass flow rates of hydrogen and oxygen production and the input electrical energy is as follows: , ; Where I is the electrolytic cell operating current (A), specifically 120000A, and t is the operating time (s). The current efficiency (dimensionless) of the water electrolysis device is 92%. The molar mass of H2 (kg / mol) is specifically 0.002 kg / mol. Let O2 be the molar mass (kg / mol), specifically 0.032 kg / mol, and F be the Faraday constant, specifically 96485 C / mol. The calculated hydrogen production mass flow rate is 0.0115 kg / s (hydrogen production volume flow rate 120 m³ / s). 3 / h), oxygen production mass flow rate is 0.092 kg / s (oxygen production volume flow rate 60 m³ / h). 3 / h, which is 200m 3 / h standard state).

[0078] The O2 generated by the water electrolysis device 3, along with the supplementary oxygen source for oxygen-enriched combustion and a portion of the CO2 separated from the oxygen-enriched combustion module of the supercritical CO2 power cycle boiler, are sent to the O2 / CO2 mixed gas storage tank 10 to adjust the oxygen concentration and circulating gas ratio in the combustion atmosphere, improve combustion efficiency, and reduce oxygen production energy consumption. The generated H2, as a high-grade reducing gas, is transported through an insulated pipeline (temperature controlled at 50℃) to the CO2 / H2 catalytic reforming unit 4 (CO2 utilization and storage module) as the feed gas for CO2 catalytic reforming, ensuring the stable progress of the reforming reaction.

[0079] The solar direct power supply mode operates in conjunction with the oxygen-enriched combustion power generation mode of the supercritical CO2 power cycle boiler 11. In the solar direct power supply mode, the proportions of power supply to the water electrolysis device 3, CO2 / H2 catalytic reforming device 4, flue gas purification device 12, and CO2 compression unit 13 are 50%, 5%, 5%, and 5%, respectively. At the same time, it outputs power to the grid 17, accounting for 35% of the total power supply. The two power supply modes operate independently and can be flexibly switched to ensure the stability of the system's power consumption.

[0080] The solar-electric heating device 1 uses monocrystalline silicon photovoltaic modules with a photoelectric conversion efficiency of no less than 22%. The water electrolysis device 3 uses a proton exchange membrane (PEM) electrolyzer with a current efficiency of no less than 90%, and the energy consumption per unit of hydrogen production is controlled at 4.5~5.0 kWh / Nm³. 3 •H2, to improve the efficiency of solar energy utilization and the economics of hydrogen production.

[0081] The supercritical CO2 power circulating boiler 11 uses an oxygen-enriched combustion power generation mode. The water electrolysis device 3 is connected to the generator 2, so that when solar power generation is insufficient, the supercritical CO2 power circulating boiler 11 can generate electricity solely through the oxygen-enriched combustion mode. This ensures the normal operation of the water electrolysis device 3 and guarantees that the water electrolysis device 3 provides sufficient O2 and H2 to the entire system.

[0082] The CO2 utilization and storage module (d) realizes the resource conversion, recycling and geological storage of CO2 within the system. Its core follows the stoichiometric relationship of catalytic reforming reaction and the balance law of CO2 utilization and storage throughout the entire process. Specifically, it includes a CO2 / H2 catalytic reforming unit 4, a CO / CH4 syngas storage unit 5, a CO2 compression unit 13, a CO2 storage unit 14 and an electrolysis water unit 3, which form a closed loop with the supercritical CO2 power cycle oxygen-enriched combustion module (b) to realize the resource utilization and storage of CO2.

[0083] Among them, the CO2 / H2 catalytic reforming unit 4 adopts a fixed-bed catalytic reforming reactor of model CR-800, and the catalyst is a nickel-based supported high-temperature resistant catalyst (Ni / Al2O3, loading 15%). CO2 compression unit 13 adopts a multi-stage centrifugal CO2 compressor 16 of model C-1000; CO2 storage unit 14 adopts a deep saline aquifer injection storage well group (depth 1500m, a total of 3 injection wells). CO / CH4 synthesis gas storage unit 5 adopts a high-pressure gas cylinder group (pressure 8.0 MPa, volume 500 m³). 3 ); ① CO2 / H2 catalytic reforming reaction: CO2 (52.5 kg / s, volumetric flow rate 27000 m³ / s) from flue gas purification unit 12 3 / h) and H2 (0.0115kg / s, volumetric flow rate 120m³) from water electrolysis unit 3 3 / h), after being mixed at a molar ratio of CO2:H2=3:1, it is fed into a fixed-bed catalytic reforming reactor (4). The reactor operating temperature is controlled at 350℃ and the reaction pressure is controlled at 2.5MPa. Under the action of a nickel-based supported high-temperature resistant catalyst, a reverse water-gas shift reaction and a methanation reaction occur. The overall reaction follows , Where x is the number of moles of reactant CO2, specifically equal to 3; y is the number of moles of reactant H2, specifically equal to 10; a is the number of moles of product CO, specifically equal to 1; b is the number of moles of product CH4, specifically equal to 2; and c is the number of moles of product H2O, specifically equal to 4, satisfying the law of conservation of elements (x = a + b, 2y = 2a + 4b + 2c).

[0084] CO2 is converted into CO / CH4 syngas through catalytic reforming. The resource conversion efficiency of the syngas is quantified by the following formula, reflecting the degree of effective utilization of CO2: , in, The specific CO2 molar flow rate (mol / s) participating in the reaction is 2.38 mol / s. The CO2 molar flow rate (mol / s) fed into the reforming unit is specifically 2.79 mol / s. The CO2 catalytic reforming conversion rate (%) is 85.3%; The CO / CH4 syngas generated by the reaction (CO volume fraction 25%, CH4 volume fraction 65%, other gases 10%) has high industrial utilization value. It is transported to CO / CH4 syngas storage unit 5 through pipeline, and stored after dehydration and purification at a storage pressure of 8.0 MPa. It can be used as a chemical raw material (for the synthesis of methanol and ethylene) or fuel gas, realizing the resource utilization of CO2. The chemical energy flow rate of the syngas is 18000 kW.

[0085] ② CO2 Sequestration Process: CO2 (45 kg / s, volumetric flow rate 23000 m³ / s) from flue gas purification unit 12 3The CO2 is fed into a multi-stage centrifugal CO2 compressor 16. After four stages of compression, the pressure rises to 12 MPa and the temperature rises to 120℃, forming a supercritical CO2 fluid (supercritical state of CO2: temperature ≥31.1℃, pressure ≥7.38 MPa). It is then transported to the deep saline aquifer injection and storage well group through the delivery pipeline (insulated and pressure resistant). The CO2 is injected into the deep saline aquifer at a depth of 1500m through the injection well, realizing the long-term geological storage of CO2. The storage rate is 45 kg / s, and the annual CO2 storage is about 1.42 million tons, ensuring that the CO2 generated in the system is not directly discharged.

[0086] The entire CO2 distribution process of the system follows the material balance formula: , in The CO2 mass flow rate (kg / s) returned to the boiler cold wall for circulation is specifically 150 kg / s. The CO2 mass flow rate (kg / s) returned to the boiler cold wall for circulation is specifically 22.5 kg / s. The CO2 mass flow rate (kg / s) fed into the catalytic reforming unit is specifically 52.5 kg / s. The CO2 mass flow rate (kg / s) fed into the storage unit is specifically 45 kg / s. The system CO2 leakage mass flow rate (kg / s) is 10 kg / s (negligible). Therefore, it can be seen that the entire system's CO2 distribution follows the material balance formula, ensuring a balance between the total amount of CO2 recycling, resource conversion, and storage, avoiding direct CO2 emissions into the atmosphere, and achieving the near-zero carbon emission target.

[0087] Meanwhile, the reaction temperature of the CO2 / H2 catalytic reforming unit 4 is controlled at 300~400℃, the reaction pressure is controlled at 2.0~3.0MPa, and a nickel-based or cobalt-based supported catalyst is used. The CO2 catalytic reforming conversion rate is not less than 85%. The CO2 compression unit 13 pressurizes the CO2 to 10~15MPa. The CO2 storage unit 14 uses a deep saline aquifer injection storage well group to meet the transportation requirements of geological storage.

[0088] In addition to the independent operation of each module, this embodiment of the system is equipped with a PLC centralized control cabinet (model S7-400+ACS800) and a variable frequency speed control system to uniformly regulate the various electrical equipment, material conveying flow, and reaction parameters, ensuring stable system operation; the overall system energy efficiency follows: , in, The overall energy efficiency of the system (dimensionless). The power (kW) of the system connected to the grid is 340,000 kW (grid-connected power of generator 2 + grid-connected power of solar power). The chemical energy flow rate (kW) of the CO / CH4 synthesis gas is 18000 kW. The heat input for coal combustion (kW) is specifically 1,000,000 kW. The solar radiation energy flow (kW) received by the photovoltaic array is 270,000 kW. The calculated comprehensive energy efficiency of the system is 0.42, which is 10.5% higher than that of the traditional coal-fired power generation system (comprehensive energy efficiency 0.38).

[0089] In summary, this system includes two power generation and supply modes: (1) The solar direct power supply mode is powered by the solar electric heating device 1 to supply power to the water electrolysis device 3, CO2 / H2 catalytic reforming device 4, flue gas purification device 12, CO2 compression unit 13, and outputs power to the external power grid 17. (2) The supercritical CO2 power cycle boiler 11 oxygen-enriched combustion power generation mode drives the supercritical CO2 turbine 6 and generator 2 through coal oxygen-enriched combustion to generate electricity, continuously supplying power to each electrical device in the system and transmitting power to the grid. The two modes can operate independently and can work together to power the system.

[0090] During system operation, all modules work together: the oxygen generation module ensures a stable oxygen source, the supercritical CO2 combustion module achieves efficient power generation, the solar energy module provides clean supplementary energy, and the CO2 utilization and storage module achieves carbon closed-loop. The entire system operates stably with low energy consumption and low pollutant emissions. The CO2 resource utilization rate reaches 35%, and the storage rate reaches 30%, achieving coordinated development of efficient power generation, clean combustion, renewable energy utilization, and carbon emission reduction.

[0091] To clearly present all the core calculation data, operating parameters and results of this embodiment, the relevant data are now compiled into a detailed statistical table, as shown in Table 1; Table 1 ; In summary, this embodiment, through the organic coupling of four major modules, strictly adheres to the structure, connection relationships, and functions defined in the claims, and combines the preferred equipment and formula requirements of the invention, to achieve supercritical CO2 oxygen-enriched combustion power generation that couples solar energy and carbon utilization and storage. This solves the technical pain points of traditional coal-fired power generation, such as low efficiency, high energy consumption for carbon capture, and large CO2 emissions. All module equipment is selected from mature industrial-grade equipment with clearly defined operating parameters and smooth process connections, allowing for direct implementation. Figure 1 and attached Figure 2 The overall structure and module layout of the system are clearly shown, which completely corresponds to the equipment and process in this embodiment, verifying the scientific nature, practicality and reproducibility of the technical solution of the present invention.

[0092] In summary, we can understand that: ① This technical solution adopts a deep coupling of supercritical CO2 power cycle and oxygen-enriched combustion, combined with a solar multi-energy complementary power supply mode, which significantly improves the overall power generation efficiency of the system compared with traditional coal-fired power generation systems. At the same time, it adopts a combined oxygen production system of cryogenic oxygen production and membrane separation oxygen production, which effectively reduces the comprehensive energy consumption of the oxygen production module and the carbon capture energy consumption of oxygen-enriched combustion. Through the closed-loop circulation of CO2 working fluid and the recovery of waste heat from flue gas, the energy utilization rate of the system is further improved, solving the technical pain points of low efficiency and high energy consumption of carbon capture and oxygen production in traditional coal-fired power generation.

[0093] ② This technical solution constructs a complete CO2 full-process treatment system. The high-purity CO2 separated by the flue gas purification device 12 is diverted and utilized in a precise ratio. Part of it is used for catalytic reforming to produce syngas for resource utilization, part of it is compressed and geologically stored, part of it is refluxed to participate in the system cycle, and part of it is used to supplement the oxygen-enriched combustion atmosphere. This realizes the synergistic promotion of CO2 resource utilization and storage, effectively reduces the overall CO2 emissions of the system, solves the greenhouse effect problem caused by direct CO2 emissions from traditional coal-fired power generation, and meets the needs of low-carbon energy development and the "dual carbon" target.

[0094] ③ This technical solution integrates two modes: solar photovoltaic power generation and supercritical CO2 oxygen-enriched combustion power generation. The two modes work together to perform corresponding power supply tasks under different light conditions, ensuring continuous and stable power supply to the system. At the same time, the two oxygen production modules can flexibly adjust the oxygen production according to the combustion load, and the CO2 diversion ratio can be precisely controlled by relevant equipment, which can adapt to different operating conditions and solve the problems of poor stability of single energy power generation and difficulty in system load adjustment.

[0095] ④ This technical solution organically couples four major modules: oxygen production, power generation, CO2 utilization and storage. The equipment selected for each module adopts mature industrial-grade equipment, with standardized connection methods and clear operating parameters, which can be directly implemented. The synthesized gas can be directly supplied to external chemical users, realizing the integration of "power generation-carbon utilization-chemical supply", expanding the industrial application scenarios of the system and improving the economy and practicality of the technology.

[0096] ⑤ The flue gas purification device 12 of this technical solution integrates multiple functions such as dust removal, desulfurization, denitrification and CO2 separation, which can effectively control the emission of various pollutants and ensure that the exhaust gas emission meets the relevant national emission standards. At the same time, the clean utilization of solar energy replaces part of the fossil energy consumption, further reducing pollutant and greenhouse gas emissions, solving the technical shortcomings of excessive pollutant emissions from traditional coal-fired power generation, and achieving synergy between clean combustion and efficient power generation.

[0097] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A supercritical CO2 combustion power generation system coupling solar energy and carbon utilization and storage, characterized in that: It includes an oxygen production module, a supercritical CO2 power cycle oxygen-enriched combustion module, a solar photovoltaic power generation module, and a CO2 utilization and storage module; The oxygen generation module is used to produce high-purity O2. The oxygen generation module transfers the produced O2 to the supercritical CO2 power cycle oxygen-enriched combustion module to provide a stable oxygen source for subsequent oxygen-enriched combustion. The oxygen concentration in the mixture follows an ideal mixing relationship to ensure that the combustion atmosphere is controllable. The supercritical CO2 power cycle oxygen-enriched combustion module is used for oxygen-enriched combustion of coal, thereby realizing supercritical CO2 working fluid circulation heat exchange for power generation. A portion of the CO2 produced by the supercritical CO2 power cycle oxygen-enriched combustion module is internally recycled. The solar photovoltaic power generation module includes a solar electric heating device (1) and an electrolysis water device (3). The solar electric heating device (1) is used to directly convert solar energy into electrical energy output by solar cells, and at the same time supplies power to the electrolysis water device (3). The electrolysis water device (3) outputs O2 and H2 to the entire system. The CO2 utilization and storage module is used to reuse and store another part of the CO2 in the whole system, ensuring that there is no CO2 emission from the whole system. At the same time, it converts H2 into reformed and stored H2 for industrial applications. The supercritical CO2 power cycle oxygen-enriched combustion module and the solar photovoltaic power generation module operate independently and work together to supply power to the entire system and transmit power to the external power grid (17); The CO2 utilization and storage module and the supercritical CO2 power cycle oxygen-enriched combustion module form a closed loop, so that all the CO2 generated in the system can be utilized or stored as a resource, with no direct external emission. The modules are interconnected through material flow, energy flow and information flow.

2. The supercritical CO2 combustion power generation system coupling solar energy and carbon utilization and storage according to claim 1, characterized in that: The oxygen generation module includes a cryogenic oxygen generation unit (8) and a membrane separation oxygen generation unit (9). The cryogenic oxygen generation unit (8) utilizes the boiling point difference between oxygen and nitrogen in the air to produce high-purity O2 through multiple processes. The membrane separation oxygen generation unit (9) utilizes the different permeation rates of various components in the air through the membrane. Driven by the pressure difference, oxygen in the air preferentially passes through the membrane to obtain oxygen-enriched air. The oxygen generation module, including the cryogenic oxygen generation unit (8) and the membrane separation oxygen generation unit (9), is connected to the supercritical CO2 power cycle oxygen-enriched combustion module.

3. The supercritical CO2 combustion power generation system coupling solar energy and carbon utilization and storage according to claim 1, characterized in that: The supercritical CO2 power cycle oxygen-enriched combustion module includes a feeder (7), an O2 / CO2 mixed gas storage tank (10), a supercritical CO2 power cycle boiler (11), a supercritical CO2 turbine (6), a generator (2), a flue gas purification device (12), a heat exchanger (15), and a compressor (16). The input end of the feeder (7) is connected to the outside, and the output end is connected to the fuel input end of the supercritical CO2 power cycle boiler (11). The input end of the supercritical CO2 power cycle boiler (11) is connected to the output end of the O2 / CO2 mixed gas storage tank (10). The input end of the O2 / CO2 mixed gas storage tank (10) is connected to the oxygen generation module and the water electrolysis device (3). The output end of the supercritical CO2 power circulating boiler (11) is connected to the supercritical CO2 turbine (6), the supercritical CO2 turbine (6) is connected to the generator (2), and the generator (2) is connected to the water electrolysis device (3) and the external power grid (17). The feeder (7) sends external coal fuel into the supercritical CO2 power cycle boiler (11), and the O2 / CO2 mixed gas storage tank (10) simultaneously delivers O2 and CO2 into the supercritical CO2 power cycle boiler (11). Thus, the supercritical CO2 working medium is circulated and heat exchanged through the oxygen-enriched combustion of coal, which drives the supercritical CO2 turbine (6) to operate and drives the generator (2) to generate electricity.

4. The supercritical CO2 combustion power generation system coupling solar energy and carbon utilization and storage according to claim 3, characterized in that: The flue gas output end of the supercritical CO2 power cycle boiler (11) is connected to the input end of the flue gas purification device (12), the output end of the flue gas purification device (12) is connected to the input end of the heat exchanger (15), the output end of the heat exchanger (15) is connected to the input end of the compressor (16), and the output end of the compressor (16) is connected to the input end of the supercritical CO2 power cycle boiler (11). The supercritical CO2 power cycle boiler (11) separates CO2 gas from the flue gas generated by coal combustion through the flue gas purification device (12). A portion of the separated CO2 gas is heated and pressurized by the heat exchanger (15) and compressor (16) to form supercritical CO2, which is then returned to the cold wall of the supercritical CO2 power cycle boiler (11) to continue participating in heat exchange, forming a closed loop.

5. The supercritical CO2 combustion power generation system coupled with solar energy and carbon utilization and storage according to claim 4, characterized in that: The output end of the flue gas purification device (12) is also connected to the input end of the O2 / CO2 mixed gas storage tank (10) to adjust the oxygen concentration and the ratio of circulating gas in the combustion atmosphere. The output end of the flue gas purification device (12) is also connected to the CO2 utilization and storage module to collect and reform CO2, thereby realizing multi-path diversion utilization and circulation.

6. The supercritical CO2 combustion power generation system coupled with solar energy and carbon utilization and storage according to claim 5, characterized in that: The CO2 utilization and storage module includes a CO / CH4 syngas storage unit (5) and a CO2 storage unit (14). The input end of the CO / CH4 syngas storage unit (5) is connected to the output end of the CO2 / H2 catalytic reforming unit (4), and the input end of the CO2 / H2 catalytic reforming unit (4) is connected to the output end of the water electrolysis unit (3) and the output end of the flue gas purification unit (12), respectively. The H2 and a portion of CO2 generated by the electrolysis water device (3) and the combustion module of the supercritical CO2 power cycle boiler (11) are mixed and sent to the CO / CH4 syngas storage unit (5) through the CO2 / H2 catalytic reforming device (4) to produce CO / CH4 syngas for industrial application. The input end of the CO2 storage unit (14) is connected to the output end of the CO2 compression unit (13), and the input end of the CO2 compression unit (13) is connected to the output end of the flue gas purification device (12). The supercritical CO2 power cycle boiler (11) combustion module stores a portion of the generated CO2 in the CO2 storage unit (14) through the CO2 compression unit (13) for long-term geological storage, avoiding direct CO2 discharge into the atmosphere and achieving the near-zero carbon emission target.

7. The supercritical CO2 combustion power generation system coupled with solar energy and carbon utilization and storage according to claim 6, characterized in that: The O2 / CO2 mixed gas storage tank (10) is connected to the oxygen generation module, the solar photovoltaic power generation module and the supercritical CO2 power cycle oxygen-enriched combustion module, respectively, to realize the centralized allocation and stable supply of oxygen-enriched gas.

8. The supercritical CO2 combustion power generation system coupled with solar energy and carbon utilization and storage according to claim 7, characterized in that: The O2 generated by the water electrolysis device (3) and part of the CO2 generated by the supercritical CO2 power cycle oxygen-enriched combustion module are both sent to the O2 / CO2 mixed gas storage tank (10) to provide oxygen-enriched gas for the oxygen-enriched combustion cycle of the supercritical CO2 power cycle boiler (11).

9. The supercritical CO2 combustion power generation system coupled with solar energy and carbon utilization and storage according to claim 1, characterized in that: It also includes a PLC centralized control cabinet and a variable frequency speed control system, which uniformly regulates and controls each electrical device.

10. The supercritical CO2 combustion power generation system coupled with solar energy and carbon utilization and storage according to any one of claims 1 to 9, characterized in that: This system includes two power generation and supply modes: (1) The solar direct power supply mode is powered by solar electric heating equipment (1) to continuously supply power to each electrical device in the system and transmit power to the grid. (2) The supercritical CO2 power cycle boiler (11) oxygen-enriched combustion power generation mode drives the supercritical CO2 turbine (6) and generator (2) to generate electricity through the oxygen-enriched combustion of coal, continuously supplying power to each electrical device in the system and transmitting power to the grid. The two modes can operate independently and can work together to power the system.

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