Hydrogen-oxygen production system and method for coupling coal-fired power plant with renewable power generation

Abstract

This invention discloses a system and method for utilizing hydrogen and oxygen produced from renewable energy sources in a coal-fired power plant, followed by hydrogen and oxygen blending in a boiler combustion process. This system belongs to the field of boiler hydrogen and oxygen blending combustion technology. The system utilizes the high energy density and easy combustibility of hydrogen to blend with low-quality coal in the power plant, increasing the utilization rate of low-quality coal and enabling faster peak and frequency regulation, thus reducing power generation costs. Through water electrolysis technology, water is decomposed to generate high-purity oxygen. The high purity of oxygen allows for more uniform mixing with the fuel, ensuring sufficient contact during combustion and resulting in more complete combustion and more efficient energy release. Simultaneously, a stable oxygen supply ensures continuous and stable combustion within the furnace, improving combustion efficiency and stability.

Description

Technical Field

[0001] This invention belongs to the field of boiler hydrogen and oxygen blending combustion technology, specifically relating to a utilization system and method for hydrogen and oxygen production from coal-fired power plants coupled with renewable power generation and boiler hydrogen and oxygen blending combustion. Background Technology

[0002] Under the "dual carbon" goal, wind and solar renewable energy are developing on a large scale. However, due to natural conditions, their power generation is fluctuating and intermittent. After a large number of units are connected to the grid, coal-fired power plants need to flexibly regulate peak loads to ensure grid stability. Furthermore, most coal-fired power plants burn low-quality coal with high ash and low volatile matter content. This type of coal is difficult to ignite and burns unstably, resulting in low efficiency and an inability to meet rapid load changes, thus limiting peak load regulation capabilities. However, hydrogen has a fast combustion speed and low ignition point, and there is ample space around coal-fired power plants, making it suitable for the construction of photovoltaic power plants. The green electricity generated by the photovoltaic power plant can be used to electrolyze water to produce hydrogen and oxygen, forming a coupled system. This can both absorb photovoltaic power and improve the stability and load-changing capacity of coal-fired boilers, contributing to the low-carbon energy transition.

[0003] Regarding hydrogen-blended combustion methods for coal-fired boilers, Chinese patent application CN119436120A discloses a coal-hydrogen co-combustion boiler system and a method for co-combusting hydrogen in a coal-fired boiler. This method involves arranging a hydrogen combustion unit below the pulverized coal combustion unit to co-combust hydrogen into the coal-fired boiler. However, its placement is too simplistic and cannot meet the requirements of coal-fired boilers under different loads, nor is it applicable to all boiler types. Chinese patent application CN119934515A discloses a flue gas recirculation hydrogen-blended combustion peak-shaving and stable combustion system and method. This system uses water electrolysis to produce hydrogen and oxygen, which is then incorporated into the furnace to achieve stable, safe, and cost-effective boiler combustion during deep air adjustment. However, its flue gas-hydrogen burner design results in an excessively wide explosive concentration range for hydrogen, leading to lower safety during co-combustion. Furthermore, hydrogen's ability to compete for oxygen is far greater than that of flue gas, causing incomplete combustion of the flue gas and exacerbating environmental pollution. Summary of the Invention

[0004] The purpose of this invention is to provide a utilization system and method for a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and boiler combustion with added hydrogen and oxygen, in order to solve the technical problems of poor coal combustion stability and weak load-changing capacity in power plants.

[0005] To achieve the above objectives, the present invention employs the following technical solution: This invention discloses a utilization system for a coal-fired power plant coupled with renewable power generation for hydrogen and oxygen production and boiler combustion with added hydrogen and oxygen. The system includes a renewable power generation device, a water electrolysis device, a coal-fired boiler, a demineralized water device, a desulfurization device, a flue gas moisture recovery device, a carbon capture and nitrogen production device, a methanol synthesis device, a methanol burner, a pulverized coal burner, a hydrogen burner, and a nitrogen purging unit. The renewable power generation device is connected to one end of the water electrolysis device. One end of the hydrogen production end of the water electrolysis device is connected to the hydrogen burner in the coal-fired boiler, and the other end is connected to one end of the methanol synthesis device. One end of the oxygen production end of the water electrolysis device is connected to the pulverized coal burner in the coal-fired boiler, and the other end is connected to the methanol burner in the coal-fired boiler. The tail flue of the coal-fired boiler is connected to one end of the desulfurization device through a flue gas pipeline. The other end of the desulfurization device is connected to one end of the flue gas moisture recovery device, and the other end of the flue gas moisture recovery device is connected to the carbon capture and nitrogen production device. The outlet end of the demineralized water device is connected to the feed water end of the coal-fired boiler. The nitrogen-producing end of the carbon capture and nitrogen-generating unit is connected to the inlet of the nitrogen purging unit via a nitrogen supply pipeline, and the carbon dioxide-producing end is connected to the methanol synthesis unit and the pulverized coal burner via carbon dioxide supply pipelines. The methanol-producing end of the methanol synthesis unit is connected to the methanol burner in the coal-fired boiler via a methanol supply pipeline. The outlet of the nitrogen purging unit is connected to the hydrogen burner.

[0006] Furthermore, it also includes a purification device; the outlet of the demineralized water device is connected to the inlet of the electrolytic water device; the outlets of the desulfurization device and the flue gas moisture recovery device are respectively connected to the purification device and then connected to the inlet of the electrolytic water device. The water inlet of the electrolytic water device is also connected to a seawater source around the plant.

[0007] Furthermore, it also includes electrical equipment for daily life within the plant; one end of the renewable power generation device is connected to the water electrolysis device via a DC transmission cable, and the other end is connected via a transformer and transmission line to transmit the electricity generated in the renewable power generation device to the electrical equipment for daily life within the plant.

[0008] Furthermore, it also includes a co-firing system; The co-firing system includes an oxygen co-firing system and a hydrogen co-firing system; the oxygen co-firing system is installed in the pulverized coal burner and is connected to one end of the oxygen-producing end of the water electrolysis device through an oxygen-entraining pipeline. The hydrogen blending system is installed in the hydrogen burner and is connected to one end of the hydrogen production end of the water electrolysis device through a hydrogen blending pipeline. Both the oxygen-blending pipeline and the hydrogen-blending pipeline are equipped with flow regulators to ensure that when the power generation of renewable power generation devices such as wind and solar power is unstable, the flow rate of blended hydrogen and oxygen fluctuates by no more than 3-8%.

[0009] Furthermore, the oxygen blending system includes a primary air oxygen blending system and a secondary air oxygen blending system; The primary air oxygenation system includes a primary air electric valve, a primary air manual valve, a primary air nozzle, an oxygenation electric valve, an oxygenation manual valve, an oxygenation filter, an oxygen flow meter, an oxygen pressure gauge, and an oxygen concentration sensor. One end of the oxygen-generating end of the water electrolysis device is connected to one end of the primary air electric valve through an oxygen-incorporating pipeline, and the other end of the primary air electric valve is connected in sequence to the primary air manual valve, the oxygen concentration sensor and the primary air nozzle. The oxygen-enriching electric valve, oxygen-enriching manual valve, and oxygen pressure gauge are connected in sequence, and then connected to the pipelines of the primary air manual valve and the oxygen concentration sensor through pipelines.

[0010] Furthermore, the secondary air oxygenation system includes a secondary air electric valve, a secondary air manual valve, an oxygen concentration sensor, a secondary air nozzle, an oxygenation electric valve, an oxygenation manual valve, an oxygen pressure gauge, an oxygenation filter, and an oxygen flow meter. One end of the oxygen-generating end of the water electrolysis device is connected to one end of the secondary air electric valve through an oxygen-incorporating pipeline, and the other end of the secondary air electric valve is connected in sequence to the secondary air manual valve, the oxygen concentration sensor and the secondary air nozzle. The oxygen-enriching electric valve, the oxygen-enriching manual valve, and the oxygen pressure gauge are connected in sequence, and then connected to the secondary air manual valve and the oxygen concentration sensor via pipelines.

[0011] Furthermore, the hydrogen co-firing system includes a hydrogen electric valve, a hydrogen manual valve, a hydrogen filter, a hydrogen flow meter, a hydrogen concentration sensor, a hydrogen pressure gauge, a hydrogen nozzle, and a purging system; One end of the hydrogen production end of the water electrolysis device is connected to one end of the hydrogen electric valve through a hydrogen mixing pipeline. The other end of the hydrogen electric valve is connected in sequence to a hydrogen manual valve, a hydrogen filter, a hydrogen pressure gauge, a hydrogen flow meter, a hydrogen concentration sensor, and a hydrogen nozzle. The purging gas end of the nitrogen purging unit is connected to one end of the purging system, and the other end of the purging system is connected to the connecting pipeline between the hydrogen manual valve and the hydrogen filter. After merging, the gas flows out through the connecting pipeline between the hydrogen concentration sensor and the hydrogen nozzle.

[0012] Furthermore, the purging system includes a first electric purging gas valve, a first manual purging gas valve, a second electric purging gas valve, a second manual purging gas valve, and a nitrogen flow meter; The purge gas end of the nitrogen purging unit is connected in sequence to the first electric purge gas valve, the first manual purge gas valve, and the nitrogen flow meter via a purge pipeline. After the nitrogen flow meter is connected to the connecting pipeline between the hydrogen manual valve and the hydrogen filter, it flows out through the connecting pipeline between the hydrogen concentration sensor and the hydrogen nozzle, and then flows out sequentially to the second manual purge gas valve and the second electric purge gas valve.

[0013] This invention also discloses a method for the co-firing of hydrogen and oxygen in a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and then combustion in a boiler, comprising the following steps: A portion of the hydrogen produced by electrolysis in the renewable power generation unit is fed into the hydrogen burner in a coal-fired boiler for in-furnace co-firing, while the remaining hydrogen is fed into a methanol synthesis unit for methanol synthesis. A portion of the oxygen produced by electrolysis in the renewable power generation unit is fed into the pulverized coal burner in a coal-fired boiler for in-furnace co-firing, while the remaining oxygen is fed into a methanol burner. The products generated after in-furnace co-firing in the coal-fired boiler sequentially pass through a desulfurization unit, a flue gas moisture recovery unit, and a carbon capture and nitrogen co-production unit. A portion of the nitrogen produced by the carbon capture and nitrogen co-production unit is used as an industrial protective gas, while the remaining nitrogen is connected to a nitrogen purging unit as a purging gas. The flue gas water recovered from the tail end of the flue gas moisture recovery unit serves as the water source for the water electrolysis unit. The desulfurization wastewater from the desulfurization unit serves as the water source for the water electrolysis unit. The demineralized water obtained by the demineralization device is used as the water source for the water electrolysis device. The aforementioned system also includes a co-firing system; The co-firing system includes: an oxygen co-firing system and a hydrogen co-firing system; the oxygen co-firing system includes a primary air oxygen co-firing system and a secondary air oxygen co-firing system. The method of oxygen co-firing using an oxygen co-firing system is as follows: When the coal-fired boiler is running at low load, the oxygen generated by the water electrolysis device enters the primary air oxygen co-firing system and the secondary air oxygen co-firing system, and is mixed with the primary air or secondary air in the coal-fired boiler. The method of using a hydrogen co-firing system is as follows: when the coal-fired boiler needs to maintain stable combustion at low load or burn low-quality coal, the hydrogen generated by the water electrolysis device enters the hydrogen co-firing system and then enters the hydrogen burner. At medium and high loads, part of the hydrogen generated by the water electrolysis device is still co-fired into the hydrogen burner, and the other part of the hydrogen is used as reburning fuel for NOx reduction. The temperature of the primary air in the methanol burner is 110℃-160℃, and the temperature of the secondary air is 300℃-420℃. A flame-retardant strip is laid around the methanol burner; the shape of the flame-retardant strip includes, but is not limited to, circular or square shapes.

[0014] Furthermore, the coal-fired boiler is a tangentially corner boiler, a W-type flame boiler, a front and rear wall opposed-flow boiler, or a circulating fluidized bed boiler. When the coal-fired boiler is a tangentially corner boiler, the hydrogen burner is placed below any one or more of the primary air nozzles in layers A, B, C, D, E, and F at the four corners of the coal-fired boiler, or between the secondary air nozzle in layer FF and the SOFA air nozzle. The hydrogen burner is tilted 1-3° to the left, and the diameter of the resulting imaginary tangential circle is 30-50mm smaller than the original imaginary tangential circle diameter of the primary air. The methanol burner is tilted 3-6° to the left based on the original tilt angle of the pulverized coal burner, and the diameter of the resulting imaginary tangential circle is between the original imaginary tangential circle diameter of the primary air and the ideal tangential circle diameter of the hydrogen. The methanol burner is placed in the coal-fired boiler... The sidewall is located 1.5-2.5 meters from the four corners and at the same height as the primary air nozzle. When the coal-fired boiler is a W-type flame boiler, the hydrogen burner is placed in the pulverized coal nozzle area on the furnace arch or above the uppermost secondary air nozzle. The methanol burner is arranged in the sidewall area at the same height as the pulverized coal nozzle. When the coal-fired boiler is a front and rear wall opposed boiler, the hydrogen burner is located between the lowest burnout air and the uppermost pulverized coal burner or arranged on the sidewall at the same height as the two lower pulverized coal burners. The methanol burner is arranged between any two adjacent pulverized coal burners. When the coal-fired boiler is a circulating fluidized bed boiler, the hydrogen burner is located at the height of the front and rear wall coal-feeding air or between the coal-feeding air and the lower secondary air. The methanol burner is arranged between any two adjacent coal-feeding air nozzles. Considering the location of the hydrogen burner and the location of oxygen co-firing, when the coal-fired boiler is a tangentially oriented boiler, if the hydrogen burner is located below the primary air nozzle of any one of the four corner layers A, B, C, D, E, F, or below any combination of 2-3 primary air nozzles from layers A, B, C, D, E, F, then oxygen is co-fired into the secondary air nozzles of the adjacent one or two layers. If the hydrogen burner is located between the secondary air nozzle of layer FF and the SOFA air nozzle, then oxygen is co-fired only into the primary air nozzle. When the coal-fired boiler is a W-type flame boiler, if the hydrogen burner is placed within the coal-fired boiler... If the location is the pulverized coal nozzle area on the furnace arch, then oxygen is mixed into the pulverized coal nozzle; if the hydrogen burner is arranged above the uppermost secondary air nozzle, then oxygen is mixed into the pulverized coal nozzle; when the coal-fired boiler is a front and rear wall opposed boiler, and the hydrogen burner is located between the lowermost burnout air and the uppermost pulverized coal burner, then oxygen is mixed into the primary air or secondary air; if the hydrogen burner is located on the side wall at the same height as the lower two layers of pulverized coal burners, then oxygen is mixed into the lower two layers of pulverized coal burners; when the coal-fired boiler is a circulating fluidized bed boiler, oxygen is mixed into the fluidized air box, the coal spreading air nozzle, or the upper secondary air nozzle. Without considering the location of the hydrogen burner, the oxygen co-firing location is as follows: When the coal-fired boiler is a tangentially oriented boiler, all oxygen is co-fired into the bottom one or two bottom primary air layers, or into the next one, two, or three bottom secondary air layers, or into the next 1-2 bottom primary air layers and the next 1-3 bottom secondary air layers respectively; When the coal-fired boiler is a W-type flame boiler, all oxygen is co-fired into the pulverized coal nozzles, or into the next 1-2 top secondary air layers, or into the pulverized coal nozzles and any one layer of secondary air; When the coal-fired boiler is a front and rear wall opposed boiler, all oxygen is co-fired into the next 1-2 bottom pulverized coal burners, or into the burnout air; When the coal-fired boiler is a circulating fluidized bed boiler, all oxygen is co-fired into the coal spreading air, or into two layers of secondary air, or into the fluidized air box.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a utilization system for a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production, followed by hydrogen and oxygen blending and combustion in a boiler. By utilizing the high energy density and easy combustibility of hydrogen, it is blended with low-quality coal in the power plant, enabling faster and more complete combustion of the low-quality coal, increasing its utilization rate, and achieving peak and frequency regulation requirements more quickly, thus reducing power generation costs. Through water electrolysis technology, water is decomposed to generate high-purity oxygen. Utilizing oxygen for combustion, due to its high purity, it mixes more evenly with the fuel, ensuring sufficient contact during combustion, resulting in more complete combustion and more efficient energy release. Simultaneously, a stable oxygen supply ensures continuous and stable combustion within the furnace, improving combustion efficiency and stability.

[0016] Furthermore, this invention utilizes the proximity of renewable energy power plants such as wind and solar power to coal-fired power plants, using surplus electricity from these sources within and around the plant for hydrogen and oxygen production via water electrolysis. The resulting hydrogen and oxygen are then transported directly to the boiler in gaseous form over short distances for co-firing, thus solving the problems of high costs and liquefaction difficulties associated with long-distance hydrogen transportation.

[0017] Furthermore, in this invention, the carbon capture and nitrogen co-production device efficiently separates the generated carbon dioxide and nitrogen after combustion in the furnace. The collected carbon dioxide can be transported to oil fields for oil displacement operations to improve oil recovery. It can also react with hydrogen to produce methanol, which can be used not only in industrial production but also to replace a portion of the coal fed into coal-fired boilers as fuel, thereby achieving effective utilization of greenhouse gases. The collected nitrogen can be used as a protective gas in other processes or reintroduced into hydrogen-blended coal-fired boilers to purge hydrogen-blended pipelines and reduce the risks of hydrogen-blended combustion.

[0018] Furthermore, this invention introduces hydrogen as an auxiliary fuel, leveraging its high calorific value and environmentally friendly combustion products, which contrasts sharply with traditional ammonia-blended combustion technology. During combustion, the synergistic effect of hydrogen and fuel significantly optimizes the combustion path, effectively suppressing the formation of pollutants such as nitrogen oxides and substantially reducing the content of harmful substances in the combustion products. Simultaneously, the rapid combustion characteristics of hydrogen ensure more complete contact between fuel and oxygen, significantly improving combustion efficiency and enhancing the sustainability and stability of the combustion reaction. This opens up new technological pathways for improving energy utilization efficiency and reducing pollutant emissions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the utilization system of the present invention, which is a coal-fired power plant coupled with renewable power generation to produce hydrogen and oxygen, and then a boiler with hydrogen and oxygen added for combustion. Figure 2 Arrangement diagrams for burners of different furnace types; Among them: a-square-corner tangential boiler; b-W-type flame boiler; c-front and rear wall opposed boiler; d-circulating fluidized bed boiler; Figure 3 This is a system diagram of the oxygen blending system of the present invention; Wherein: a-primary air oxygenation system; b-secondary air oxygenation system; Figure 4 This is a system diagram of the hydrogen co-firing system of the present invention; Figure 5 A schematic diagram of the tangent circles at the four corners; Among them: 1-Renewable power generation unit; 2-Water electrolysis unit; 3-Coal-fired boiler; 4-Demineralized water unit; 5-Desulfurization unit; 6-Flue gas moisture recovery unit; 7-Carbon capture and nitrogen co-production unit; 8-Methanol synthesis unit; 9-Methanol burner; 10-Pulverized coal burner; 11-Hydrogen burner; 12-Nitrogen purging unit; 13-Purification unit; 14-In-plant electrical equipment; 11-1: Primary air electric valve; 11-2: Primary air manual valve; 11-3: Secondary air electric valve; 11-4: Secondary air manual valve; 17-Primary air nozzle; 21-Secondary air nozzle; 13-1: Oxygen blending Electric valve; 13-2: Oxygen-blending manual valve; 14-1: Oxygen-blending filter; 16-1: Oxygen flow meter; 15-1: Oxygen pressure gauge; 12-1: Oxygen concentration sensor; 18-1: Hydrogen electric valve; 18-2: Hydrogen manual valve; 14-2: Hydrogen filter; 16-2: Hydrogen flow meter; 12-2: Hydrogen concentration sensor; 15-2: Hydrogen pressure gauge; 19-1: First electric valve for purge gas; 19-2: First manual valve for purge gas; 19-3: Second electric valve for purge gas; 19-4: Second manual valve for purge gas; 20: Hydrogen nozzle; 16-3: Nitrogen flow meter. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] This invention provides a utilization system for a coal-fired power plant coupled with renewable power generation for hydrogen and oxygen production and boiler combustion with added hydrogen and oxygen. The system mainly includes a renewable power generation device (such as wind and solar power) around the plant 1, an electrolysis water device 2, a coal-fired boiler 3, a demineralized water device 4, a desulfurization device 5, a flue gas moisture recovery device 6, a carbon capture and nitrogen co-production device 7, a methanol synthesis device 8, a methanol burner 9, a pulverized coal burner 10, a hydrogen burner 11, and a nitrogen purging unit 12. The power transmission ends of the renewable power generation devices 1 (wind, solar, etc.) around the plant are connected to one end of the water electrolysis unit 2 via DC transmission cables. One end of the hydrogen production end of the water electrolysis unit 2 is connected to the hydrogen burner 11 in the coal-fired boiler 3 via a hydrogen blending pipeline, and the other end is connected to one end of the methanol synthesis unit 8 via a hydrogen transmission pipeline. One end of the oxygen production end of the water electrolysis unit 2 is connected to the primary or secondary air duct of the pulverized coal burner 10 in the coal-fired boiler 3 via an oxygen blending pipeline, and the other end is connected to the methanol burner 9 in the coal-fired boiler 3 via an oxygen blending pipeline. The tail flue of the coal-fired boiler 3 is connected to one end of the desulfurization unit 5 via a flue gas pipeline. The other end of the desulfurization unit 5 is connected to one end of the flue gas moisture recovery unit 6, and the other end of the flue gas moisture recovery unit 6 is connected to the carbon capture and nitrogen production unit 7. The nitrogen production end of the carbon capture and nitrogen production unit 7 is connected to the nitrogen purging unit 12 through the nitrogen supply pipeline, and the carbon dioxide production end is connected to the methanol synthesis unit 8 and the pulverized coal burner 10 through the carbon dioxide supply pipeline. The methanol production end of the methanol synthesis unit 8 is connected to the methanol burner 9 in the coal-fired boiler 3 through the methanol supply pipeline. The water outlets of the desulfurization unit 5 and the flue gas moisture recovery unit 6 are respectively connected to the purification unit 13 and then connected to the water inlet of the electrolysis water unit 2. The green electricity generated by the renewable power generation unit 1, using wind and solar power, is used in the water electrolysis unit 2 to produce hydrogen and oxygen. Part of the hydrogen is used for in-furnace co-firing, and the oxygen is added to the primary or secondary air ducts to increase the oxygen content. The tail gas from the coal-fired boiler 3 enters the carbon capture and nitrogen co-production unit 7 to separate nitrogen and carbon dioxide. The separated high-purity carbon dioxide is not limited to its use in synthesizing methanol with another portion of the hydrogen, for oilfield flooding, or for oxygen-enriched combustion in the furnace. The separated high-purity nitrogen is not limited to its use in purging hydrogen pipelines, preventing hydrogen explosions, or as a protective gas in other processes. The methanol in the methanol synthesis unit 8 can replace a portion of the coal fed into the coal-fired boiler 3 as fuel. The water electrolysis unit 2 also transmits the electricity generated in the renewable power generation unit 1 to the plant's residential electrical equipment 14 via transformers and power lines.

[0023] Preferably, the co-firing system includes an oxygen co-firing system and a hydrogen co-firing system. The oxygen co-firing system mainly includes: a primary air electric valve 11-1, a primary air manual valve 11-2, a secondary air electric valve 11-3, a secondary air manual valve 11-4, a primary air nozzle 17, a secondary air nozzle 21, an oxygen-blending electric valve 13-1, an oxygen-blending manual valve 13-2, an oxygen-blending filter 14-1, an oxygen flow meter 16-1, an oxygen pressure gauge 15-1, and an oxygen concentration sensor 12-1. Primary air passes through the primary air electric valve 11-1 and the primary air manual valve 11-2, and then reaches the primary air nozzle 17 before being injected into the furnace. Secondary air passes through the secondary air electric valve 11-3 and the secondary air manual valve 11-4, and then reaches the secondary air nozzle 21 before being injected into the furnace. Meanwhile, oxygen from an external oxygen source is filtered sequentially through an oxygen blending electric valve 13-1, an oxygen blending manual valve 13-2, and an oxygen blending filter 14-1. After the flow rate is measured by an oxygen flow meter 16-1 and the pressure is monitored by an oxygen pressure gauge 15-1, the oxygen is combined with the primary or secondary air duct and blended into the primary or secondary air. The mixed gas passes through an oxygen concentration sensor 12-1 to monitor the oxygen concentration, ensuring the stability and efficiency of the combustion process. The hydrogen blending system mainly includes: a hydrogen electric valve 18-1, a hydrogen manual valve 18-2, a hydrogen filter 14-2, a hydrogen flow meter 16-2, a hydrogen concentration sensor 12-2, a hydrogen pressure gauge 15-2, a first purge gas electric valve 19-1, a first purge gas manual valve 19-2, a second purge gas electric valve 19-3, a second purge gas manual valve 19-4, a hydrogen nozzle 20, and a hydrogen flow meter 16-3. Hydrogen gas passes sequentially through hydrogen electric valve 18-1, hydrogen manual valve 18-2, hydrogen filter 14-2, hydrogen flow meter 16-2, hydrogen concentration sensor 12-2, and hydrogen pressure gauge 15-2 before reaching hydrogen nozzle 20 and being injected into the furnace. Purge gas passes sequentially through purge gas first electric valve 19-1, purge gas first manual valve 19-2, purge gas second electric valve 19-3, and purge gas second manual valve 19-4 before merging with the hydrogen pipeline to purge it. Hydrogen electric valve 18-1 and the manual valve control the on / off state and flow rate; hydrogen filter 14-2 filters impurities; hydrogen flow meter 16-2 measures the flow rate; hydrogen concentration sensor 12-2 monitors the concentration; and hydrogen pressure gauge 15-2 monitors the pressure.

[0024] The oxygen co-firing method used in the system is as follows: When the boiler is running at medium and low loads, the oxygen generated by the water electrolysis device 2 enters the oxygen blending pipeline, and the oxygen flows through the oxygen blending pipeline into the boiler's primary air duct or secondary air duct to be mixed with the boiler's primary or secondary air. After the oxygen is mixed with the primary or secondary air, the increase in the oxygen volume concentration is between 1% and 6%. The hydrogen co-firing method is as follows: When it is necessary to start up the boiler, maintain stable combustion at low loads, or burn low-quality coal, the hydrogen generated by the water electrolysis device 2 enters the hydrogen blending pipeline, and the hydrogen is sent from the hydrogen blending pipeline to the hydrogen burner 11 arranged on the lower furnace water-cooled wall side. At medium and high loads, part of the hydrogen generated by the water electrolysis device 2 is still blended into the hydrogen burner 11 on the lower furnace water-cooled wall side, and the other part of the hydrogen is blended into the hydrogen burner 11 on the upper furnace water-cooled wall side as reburning fuel for NOx reduction.

[0025] Furthermore, the electrical energy for the water electrolysis unit 2 comes from, but is not limited to, plant-use photovoltaic units or wind turbine units, and all renewable energy power generation devices are located within or around the plant. The water in the water electrolysis unit 2 comes from, but is not limited to, seawater around the plant, demineralized water from the coal-fired unit 4, circulating water, wet desulfurization wastewater from the desulfurization unit 5, or water recovered from the flue gas by the flue gas recovery unit 6, which recovers water from the tail flue gas of pure coal combustion, coal-hydrogen co-combustion, and coal-hydrogen-methanol combustion in coal-fired boilers.

[0026] Preferably, the temperature of the primary air in the methanol burner 9 is 110℃-160℃, and the temperature of the secondary air is 300℃-420℃. Furthermore, a flame-retardant strip is laid around the methanol burner 9, and the shape of the flame-retardant strip is not limited to circular, square, or other shapes.

[0027] This invention also discloses the above-mentioned method for hydrogen and oxygen production from coal-fired power plants coupled with renewable energy sources such as wind and solar power, followed by hydrogen and oxygen blending combustion in boilers. A high-precision pressure transmitter and flow sensor are installed on the oxygen blending pipeline to monitor the pressure and flow parameters during oxygen delivery in real time, ensuring consistent parameters for the supplied oxygen. The primary or secondary air blending pipeline receives oxygen mixed with the primary or secondary air, calculated based on the fuel required for combustion in the coal-fired boiler 3, controlled by an intelligent regulating valve. A high-sensitivity hydrogen leak detection probe is installed in the hydrogen blending pipeline to ensure safe hydrogen delivery. During combustion, the hydrogen is precisely metered by a high-precision mass flow controller based on the boiler load and combustion conditions, and then sent to the hydrogen burner 11 for combustion.

[0028] Preferably, before hydrogen combustion, a nitrogen purging unit 12 is used to ensure that no residual combustible gas accumulates in the boiler furnace and to prevent safety accidents such as hydrogen explosions. This unit uses nitrogen collected after nitrogen production from carbon capture as the purging medium. The purging process strictly follows these steps: First, all hydrogen supply valves are closed to ensure that the hydrogen source is isolated from the furnace; then, the nitrogen purging valves are opened, allowing nitrogen to enter the furnace through a dedicated purging pipe at a flow rate of ≥15 m / s. The purging continues until the volume concentration of combustible gas in the furnace is reduced to below the lower explosive limit before oxygen and hydrogen are sequentially introduced for combustion.

[0029] Preferably, flow regulators are added to the oxygen-blending and hydrogen-blending pipelines to ensure that the flow rate of blended hydrogen and oxygen does not fluctuate by more than 3-8% when the power generation of renewable power generation devices such as wind and solar is unstable.

[0030] Preferably, for a corner-shaped tangential boiler, the hydrogen burner 11 can be positioned below any one or more of the primary air nozzles 17 in layers A, B, C, D, E, and F at the four corners of the boiler, or between the secondary air nozzle 21 and the SOFA air nozzle in layer FF. The hydrogen burner 11 is tilted 1-3° to the left, and the diameter of the resulting imaginary tangential circle is 30-50 mm smaller than the original imaginary tangential circle diameter of the primary air. The number of hydrogen burners 11 can be 4, 8, or 12. The methanol burner 9 can be positioned on the side wall at a distance of 1.5-2.5 meters from the four corners and at the same height as the primary air nozzles in layers A and B. The number of methanol burners 9 can be 4 or 8. For a W-type flame boiler, the hydrogen burner 11 can be positioned near the pulverized coal nozzle on the furnace arch, or above the uppermost secondary air nozzle. The number of hydrogen burners 11 can be 2 or 4. Methanol burners 9 can be arranged in the sidewall area at the same height as the pulverized coal nozzle, and the number of methanol burners 9 can be 2. For boilers with opposing front and rear walls, hydrogen burners 11 can be arranged between the lowest burnout air and the highest pulverized coal burner, or on the sidewall at the same height as the two lower pulverized coal burners, and the number of hydrogen burners 11 can be 4, 6, or 8. Methanol burners 9 can be arranged between any two adjacent pulverized coal burners, and the number of methanol burners 9 can be 3, 4, 6, or 8. For circulating fluidized bed boilers, hydrogen burners 11 can be located at the height of the front and rear wall coal-feeding air or between the coal-feeding air and the lower secondary air, and the number of hydrogen burners 11 can be 2 or 4. Methanol burners 9 can be arranged between any two adjacent coal-feeding air nozzles, and the number of methanol burners 9 can be 2.

[0031] Preferably, considering the location of the hydrogen burner 11 and the oxygen co-firing position, for a tangentially oriented boiler, if the hydrogen burner 11 is located below any one of the primary air nozzles 17 in layers A, B, C, D, E, and F at the four corners of the boiler, or below any combination of 2-3 primary air nozzles 17 in layers A, B, C, D, E, and F, then oxygen is co-fired into the secondary air nozzles of the adjacent layer or two layers; if the hydrogen burner 11 is located between the secondary air nozzle 21 in layer FF and the SOFA air nozzle, then oxygen is co-fired only into the primary air nozzles B and C; for a W-type flame boiler, if the hydrogen burner 11 is located below the primary air nozzles 17 in layer FF, then oxygen is co-fired into the secondary air nozzles 17 in layer FF. Oxygen is mixed into the pulverized coal nozzles if they are located near the pulverized coal nozzles on the furnace arch or on the side walls at the same height as the pulverized coal nozzles; if the hydrogen burner 11 is arranged above the uppermost secondary air nozzle, oxygen is mixed into the pulverized coal nozzle; for a boiler with opposing front and rear walls, if the hydrogen burner 11 is arranged between the lowermost burnout air and the uppermost pulverized coal burner, oxygen is mixed into the primary or secondary air; if it is arranged on the side walls at the same height as the lower two pulverized coal burners, oxygen is mixed into the lower two pulverized coal burners; for a circulating fluidized bed boiler, oxygen is mixed into the fluidizing air box, the coal feeding air nozzle, or the upper secondary air nozzle.

[0032] Without considering the position of the hydrogen burner 11, the oxygen co-firing position is as follows: For a tangentially oriented boiler, all oxygen is co-fired into the bottom one or two bottom primary air layers, or into the next one, two, or three bottom secondary air layers, or into the next 1-2 bottom primary air layers and the next 1-3 bottom secondary air layers respectively; For a W-type flame boiler, all oxygen is co-fired into the pulverized coal nozzle, or into the next 1-2 top secondary air layers, or into the pulverized coal nozzle and any one layer of secondary air; For a front and rear wall opposed boiler, all oxygen is co-fired into the next 1-2 bottom pulverized coal burners, or into the burnout air; For a circulating fluidized bed boiler, all oxygen is co-fired into the coal feeding air, or into two layers of secondary air, or into the fluidizing air box.

[0033] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0034] like Figure 1 As shown, this invention discloses a utilization system for a coal-fired power plant coupled with renewable energy power generation for hydrogen and oxygen production, followed by hydrogen and oxygen blending and combustion in a boiler. The renewable energy power generation devices, such as wind and solar power plants, are located near the coal-fired power plant, which is close to the sea. The green electricity generated by the renewable energy power generation devices 1 around the plant is used to electrolyze seawater in a water electrolysis device 2 to produce hydrogen and oxygen. The resulting hydrogen and oxygen are then directly fed into the furnace through oxygen blending pipelines and hydrogen blending pipelines for low-load stable combustion or variable-load regulation. (Reference) Figure 2 A. Layout diagram of the four-corner tangential boiler burners: Hydrogen burners 11 are positioned below the primary air nozzles of layer A, with four units arranged. Methanol burners 9 are positioned on the side walls 1.5 meters from the four corners and at the same height as the primary air nozzles of layer A, with four units arranged. The primary air temperature in methanol burners 9 is 150℃, and the secondary air temperature is 380℃. This enhances the atomization capability at the nozzles, improves flame stability and burnout rate. A flame-retardant strip is laid around methanol burners 9 to enhance stable combustion. Pure oxygen generated from water electrolysis is only incorporated into the secondary air of layers AA and AB through oxygen-incorporating pipelines, increasing the oxygen volume concentration by 3%. When renewable energy power generation from wind and solar is sufficient, only oxygen needs to be introduced to improve the oxygen concentration in the furnace to achieve stable combustion. When changing coal types or when renewable energy power generation is insufficient, hydrogen is introduced into the furnace. Due to the high energy density of hydrogen, the furnace temperature rises rapidly, allowing the pulverized coal to quickly reach the ignition temperature for combustion, thus enabling a rapid increase in load. Under stable load conditions, methanol can be injected to replace a portion of the coal fed into the furnace for combustion.

[0035] like Figure 2 As shown in Figure b, in a W-type flame boiler, two hydrogen burners 11 are arranged below the pulverized coal burners on the furnace arch; two methanol burners 9 are arranged on the side wall at the same height as the pulverized coal nozzles, with oxygen mixed into the pulverized coal nozzles. When maintaining stable combustion at low load in the furnace, the hydrogen burners 11 on the furnace arch increase the furnace temperature by injecting hydrogen into the furnace, allowing for more complete combustion of the pulverized coal. The oxygen mixed into the pulverized coal nozzles ensures sufficient oxygen for both hydrogen and pulverized coal combustion, preventing hydrogen from competing for oxygen and causing incomplete combustion. At full load, the methanol burners 9 on the furnace arch replace some of the pulverized coal as fuel by injecting methanol into the furnace, reducing the generation of nitrogen oxides. Figure 2 As shown in Figure c, in a counter-flow boiler with opposing front and rear walls, four hydrogen burners 11 are arranged between the lowest burnout air layer and the highest pulverized coal burner; three methanol burners 9 are arranged between adjacent lowest pulverized coal burners. Oxygen is mixed into the lowest pulverized coal burner. The hydrogen injected into the furnace can serve as a reburning fuel, ensuring stable combustion of low-quality coal and reducing the formation of nitrogen oxides. The oxygen mixed into the lowest pulverized coal burner provides sufficient oxygen for hydrogen combustion. During high-load stable combustion, methanol is injected to replace pulverized coal combustion; for example... Figure 2As shown in diagram d, in a circulating fluidized bed boiler, two hydrogen burners 11 are arranged between the coal-feeding air and the lower secondary air; two methanol burners 9 are arranged between any two adjacent coal-feeding air nozzles. Oxygen is mixed into the fluidized air box. The injected hydrogen can be used as a reburning fuel, reducing nitrogen oxide generation and improving the burnout rate of low-quality coal during low-load combustion or when burning low-quality coal. The oxygen mixed into the fluidized air box increases the oxygen concentration in the furnace, ensuring that both hydrogen and pulverized coal can burn completely. When combustion is stable in the furnace, methanol is injected to replace pulverized coal for combustion.

[0036] like Figure 3 As shown, the oxygen blending system of the present invention mainly includes: a primary air electric valve 11-1, a primary air manual valve 11-2, a secondary air electric valve 11-3, a secondary air manual valve 11-4, a primary air nozzle 17, a secondary air nozzle 21, an oxygen blending electric valve 13-1, an oxygen blending manual valve 13-2, an oxygen blending filter 14-1, an oxygen flow meter 16-1, an oxygen pressure gauge 15-1, and an oxygen concentration sensor 12-1. The primary air passes through the primary air electric valve 11-1 and the primary air manual valve 11-2, and then reaches the primary air nozzle 17 and is injected into the furnace. The secondary air passes through the secondary air electric valve 11-3 and the secondary air manual valve 11-4, and then reaches the secondary air nozzle 21 and is injected into the furnace. Meanwhile, oxygen from an external oxygen source is filtered sequentially through an oxygen-blending electric valve 13-1, an oxygen-blending manual valve 13-2, and an oxygen-blending filter 14-1. After the flow rate is measured by an oxygen flow meter 16-1 and the pressure is monitored by an oxygen pressure gauge 15-1, the oxygen is then combined with the primary or secondary air duct and incorporated into the primary or secondary air supply. The mixed gas then passes through an oxygen concentration sensor 12-1 to monitor the oxygen concentration, ensuring the stability and efficiency of the combustion process.

[0037] like Figure 4As shown, the hydrogen co-firing system of the present invention mainly includes: a hydrogen electric valve 18-1, a hydrogen manual valve 18-2, a hydrogen filter 14-2, a hydrogen flow meter 16-2, a hydrogen concentration sensor 12-2, a hydrogen pressure gauge 15-2, a first purge gas electric valve 19-1, a first purge gas manual valve 19-2, a second purge gas electric valve 19-3, a second purge gas manual valve 19-4, a hydrogen nozzle 20, and a hydrogen flow meter 16-3. Hydrogen supplied from the water electrolysis unit 2 passes sequentially through the hydrogen electric valve 18-1 and the hydrogen manual valve 18-2, which together control the on / off state and flow rate of the hydrogen. Next, the hydrogen flows into the hydrogen filter 14-2 to remove any impurities and ensure the purity of the hydrogen. The filtered hydrogen then passes through the hydrogen flow meter 16-2, which accurately measures the flow rate of the hydrogen to ensure that the hydrogen supply meets the requirements of the combustion process. Before entering the hydrogen concentration sensor 12-2, the hydrogen gas passes through the hydrogen pressure gauge 15-2 to monitor its pressure, ensuring that it flows within a safe pressure range. Finally, the hydrogen gas reaches the hydrogen nozzle 20 and is fed into the furnace for combustion. Before each hydrogen-blended combustion operation, the purge gas passes sequentially through the first electric purge gas valve 19-1 and the first manual purge gas valve 19-2, which control the flow of the purge gas. Subsequently, the purge gas enters the second electric purge gas valve 19-3 and the second manual purge gas valve 19-4, further regulating its flow rate and pressure to effectively clean and protect the hydrogen pipeline.

[0038] The flue gas generated after combustion in the furnace is recovered and converted into carbon dioxide and nitrogen through the carbon capture and nitrogen production unit 7. The carbon dioxide can be used for oilfield enhanced oil recovery, or it can be combined with excess hydrogen generated in the water electrolysis unit to synthesize methanol, reducing the environmental pollution caused by flue gas generated after boiler combustion and utilizing pollutants as resources. It can also be mixed into the furnace for oxygen-enriched combustion. Nitrogen can be used as a protective gas in other processes or sent to the hydrogen-blending pipeline of the hydrogen-blending boiler for purging to prevent pipeline explosions caused by excess gas in the pipeline.

[0039] The co-firing of hydrogen effectively increases the mixing degree of air and fuel, which is beneficial to stable combustion in the furnace and prolongs the residence time of pulverized coal in the furnace. Because of the added hydrogen jet, the jet velocity in the co-firing condition is increased compared to the basic operating condition, and the airflow rotation is enhanced. Hydrogen-coated combustion can further improve the burnout rate of pulverized coal, but it also increases the outlet water vapor content, which raises the risk of low-temperature corrosion. Therefore, anti-corrosion treatment of related equipment is necessary. At the same time, higher requirements are placed on the hydrogen embrittlement resistance of pipeline equipment and the high-temperature resistance of the burner.

[0040] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A utilization system for a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production, followed by hydrogen and oxygen blending and combustion in a boiler, characterized in that... It includes a renewable power generation unit (1), an electrolysis water unit (2), a coal-fired boiler (3), a demineralized water unit (4), a desulfurization unit (5), a flue gas moisture recovery unit (6), a carbon capture and nitrogen production unit (7), a methanol synthesis unit (8), a methanol burner (9), a pulverized coal burner (10), a hydrogen burner (11), and a nitrogen purging unit (12). The renewable power generation device (1) is connected to one end of the water electrolysis device (2). One end of the hydrogen production end of the water electrolysis device (2) is connected to the hydrogen burner (11) in the coal-fired boiler (3), and the other end of the hydrogen production end is connected to one end of the methanol synthesis device (8). One end of the oxygen production end of the water electrolysis device (2) is connected to the pulverized coal burner (10) in the coal-fired boiler (3), and the other end of the oxygen production end is connected to the methanol burner (9) in the coal-fired boiler (3). The tail flue of the coal-fired boiler (3) is connected to one end of the desulfurization device (5) through the flue gas pipeline. The other end of the desulfurization device (5) is connected to one end of the flue gas moisture recovery device (6), and the other end of the flue gas moisture recovery device (6) is connected to the carbon capture and nitrogen production device (7). The outlet end of the demineralized water device (4) is connected to the feed water end of the coal-fired boiler (3). The nitrogen-producing end of the carbon capture and nitrogen-generating unit (7) is connected to the inlet of the nitrogen purging unit (12) through a nitrogen supply pipeline, and the carbon dioxide-producing end is connected to the methanol synthesis unit (8) and the pulverized coal burner (10) through a carbon dioxide supply pipeline. The methanol-producing end of the methanol synthesis unit (8) is connected to the methanol burner (9) in the coal-fired boiler (3) through a methanol supply pipeline. The outlet of the nitrogen purging unit (12) is connected to the hydrogen burner (11).

2. The utilization system of a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and boiler combustion according to claim 1, characterized in that, It also includes a purification device (13); the outlet of the demineralized water device (4) is connected to the inlet of the electrolytic water device (2); the outlets of the desulfurization device (5) and the flue gas moisture recovery device (6) are respectively connected to the purification device (13) and then connected to the inlet of the electrolytic water device (2). The water inlet of the electrolytic water device (2) is also connected to a seawater source around the plant.

3. The utilization system of a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and subsequent combustion in a boiler, as described in claim 1, is characterized in that... It also includes the factory's living equipment (14); one end of the renewable power generation device (1) is connected to the water electrolysis device (2) via a DC power transmission cable, and the other end of the water electrolysis device (2) is connected via a transformer and a power transmission line to transmit the electricity generated in the renewable power generation device (1) to the factory's living equipment (14).

4. The utilization system of a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and boiler combustion according to claim 1, characterized in that, It also includes a co-firing system; The co-firing system includes an oxygen co-firing system and a hydrogen co-firing system; the oxygen co-firing system is installed in the pulverized coal burner (10) and is connected to one end of the oxygen-producing end of the water electrolysis device (2) through an oxygen-coating pipeline; The hydrogen blending system is installed in the hydrogen burner (11) and is connected to one end of the hydrogen production end of the water electrolysis device (2) through a hydrogen blending pipeline; Both the oxygen-doped pipeline and the hydrogen-doped pipeline are equipped with flow regulators and stabilizers.

5. The utilization system of a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and boiler combustion according to claim 4, characterized in that, The oxygen blending system includes a primary air oxygen blending system and a secondary air oxygen blending system; The primary air oxygenation system includes a primary air electric valve (11-1), a primary air manual valve (11-2), a primary air nozzle (17), an oxygenation electric valve (13-1), an oxygenation manual valve (13-2), an oxygenation filter (14-1), an oxygen flow meter (16-1), an oxygen pressure gauge (15-1), and an oxygen concentration sensor (12-1). One end of the oxygen-producing end of the water electrolysis device (2) is connected to one end of the primary air electric valve (11-1) through an oxygen-mixing pipeline. The other end of the primary air electric valve (11-1) is connected in sequence to the primary air manual valve (11-2), the oxygen concentration sensor (12-1), and the primary air nozzle (17). The oxygen-entraining electric valve (13-1), oxygen-entraining manual valve (13-2), and oxygen pressure gauge (15-1) are connected in sequence, and then connected to the primary air manual valve (11-2) and oxygen concentration sensor (12-1) via pipelines.

6. The utilization system of a coal-fired power plant coupled with renewable power generation for hydrogen and oxygen production and boiler combustion according to claim 5, characterized in that, The secondary air oxygenation system includes a secondary air electric valve (11-3), a secondary air manual valve (11-4), an oxygen concentration sensor (12-1), a secondary air nozzle (21), an oxygenation electric valve (13-1), an oxygenation manual valve (13-2), an oxygen pressure gauge (15-1), an oxygenation filter (14-1), and an oxygen flow meter (16-1). One end of the oxygen-producing end of the water electrolysis device (2) is connected to one end of the secondary air electric valve (11-3) through an oxygen-mixing pipeline. The other end of the secondary air electric valve (11-3) is connected in sequence to the secondary air manual valve (11-4), the oxygen concentration sensor (12-1), and the secondary air nozzle (21). The oxygen-enriched electric valve (13-1), oxygen-enriched manual valve (13-2), and oxygen pressure gauge (15-1) are connected in sequence, and then connected to the secondary air manual valve (11-4) and oxygen concentration sensor (12-1) through pipelines.

7. The utilization system of a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and subsequent combustion in a boiler, as described in claim 6, is characterized in that... The hydrogen blending system includes a hydrogen electric valve (18-1), a hydrogen manual valve (18-2), a hydrogen filter (14-2), a hydrogen flow meter (16-2), a hydrogen concentration sensor (12-2), a hydrogen pressure gauge (15-2), a hydrogen nozzle (20), and a purging system; One end of the hydrogen production end of the water electrolysis device (2) is connected to one end of the hydrogen electric valve (18-1) through a hydrogen mixing pipeline. The other end of the hydrogen electric valve (18-1) is connected in sequence to the hydrogen manual valve (18-2), the hydrogen filter (14-2), the hydrogen pressure gauge (15-2), the hydrogen flow meter (16-2), the hydrogen concentration sensor (12-2), and the hydrogen nozzle (20). The purging gas end of the nitrogen purging unit (12) is connected to one end of the purging system. The other end of the purging system is connected to the connecting pipeline between the hydrogen manual valve (18-2) and the hydrogen filter (14-2). The gas flows out through the connecting pipeline between the hydrogen concentration sensor (12-2) and the hydrogen nozzle (20).

8. The utilization system of a coal-fired power plant coupled with renewable power generation for hydrogen and oxygen production and boiler combustion according to claim 7, characterized in that, The purging system includes a first electric purging gas valve (19-1), a first manual purging gas valve (19-2), a second electric purging gas valve (19-3), a second manual purging gas valve (19-4), and a nitrogen flow meter (16-3). The purge gas end of the nitrogen purging unit (12) is connected in sequence to the first electric purge gas valve (19-1), the first manual purge gas valve (19-2), and the nitrogen flow meter (16-3) through the purge pipeline. After the nitrogen flow meter (16-3) is connected to the connecting pipeline between the hydrogen manual valve (18-2) and the hydrogen filter (14-2), it flows out through the connecting pipeline between the hydrogen concentration sensor (12-2) and the hydrogen nozzle (20) and then flows out in sequence to the second manual purge gas valve (19-4) and the second electric purge gas valve (19-3).

9. The co-firing method of a utilization system for a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and boiler combustion, as described in claim 1, is characterized in that... Includes the following steps: A portion of the hydrogen produced by electrolysis in the renewable power generation unit (1) is fed into the hydrogen burner (11) in the coal-fired boiler (3) for in-furnace co-firing, and the other portion of the hydrogen produced is fed into the methanol synthesis unit (8) for methanol synthesis; a portion of the oxygen produced by electrolysis in the renewable power generation unit (1) is fed into the pulverized coal burner (10) in the coal-fired boiler (3) for in-furnace co-firing, and the other portion of the oxygen produced is fed into the methanol burner (9); the products produced by in-furnace co-firing in the coal-fired boiler (3) are sequentially fed into the desulfurization unit (5), the flue gas moisture recovery unit (6), and the carbon capture and nitrogen production unit (7); a portion of the nitrogen produced by the carbon capture and nitrogen production unit (7) is used as an industrial protective gas, and the other portion is connected to the nitrogen purging unit (12) as a purging gas; the flue gas recovery water at the tail end of the flue gas moisture recovery unit (6) is used as the water source for the water electrolysis unit (2); the desulfurization wastewater from the desulfurization unit (5) is used as the water source for the water electrolysis unit (2). The demineralized water obtained by the demineralization device (4) is used as the water source for the water electrolysis device (2); The aforementioned system also includes a co-firing system; The co-firing system includes: an oxygen co-firing system and a hydrogen co-firing system; the oxygen co-firing system includes a primary air oxygen co-firing system and a secondary air oxygen co-firing system. The method of oxygen co-firing using the oxygen co-firing system is as follows: when the coal-fired boiler (3) is running at medium and low load, the oxygen generated by the water electrolysis device (2) enters the primary air oxygen co-firing system and the secondary air oxygen co-firing system and is mixed with the primary air or secondary air in the coal-fired boiler (3). The method of using a hydrogen co-firing system is as follows: when the coal-fired boiler (3) needs to maintain stable combustion at low load or use inferior coal, the hydrogen generated by the water electrolysis device (2) enters the hydrogen co-firing system and enters the hydrogen burner (11). At medium and high loads, part of the hydrogen generated by the water electrolysis device (2) is still co-fired into the hydrogen burner (11), and the other part of the hydrogen is used as reburning fuel for NOx reduction. The temperature of the primary air in the methanol burner (9) is 110℃-160℃, and the temperature of the secondary air is 300℃-420℃; A flame-retardant strip is laid around the methanol burner (9); the flame-retardant strip is laid in a circular or square shape.

10. The method for a utilization system of a coal-fired power plant coupled with renewable energy generation for hydrogen and oxygen production and boiler combustion, as described in claim 9, is characterized in that... The coal-fired boiler (3) is a tangential boiler, a W-type flame boiler, a front and rear wall opposed boiler, or a circulating fluidized bed boiler. When the coal-fired boiler (3) is a tangential boiler, the hydrogen burner (11) is placed in the coal-fired boiler (3) below any one or more of the primary air nozzles (17) in layers A, B, C, D, E, and F at the four corners of the coal-fired boiler (3) or between the secondary air nozzles (21) and SOFA air nozzles in layer FF. The hydrogen burner (11) is tilted to the left by 1 to 3 degrees, and the diameter of the imaginary tangential circle formed is 30 to 50 mm smaller than the original imaginary tangential circle diameter of the primary air. The methanol burner (9) is tilted to the left by 3 to 6 degrees based on the tilt angle of the original pulverized coal burner (10), and the diameter of the imaginary tangential circle formed is between the original imaginary tangential circle diameter of the primary air and the ideal tangential circle diameter of the hydrogen. The methanol burner (9) is placed in the coal-fired boiler (3) at a distance of 3 to 6 degrees from the four corners of the side wall of the coal-fired boiler (3). The area is 1.5-2.5 meters high and at the same height as the primary air nozzle (17); when the coal-fired boiler (3) is a W-type flame boiler, the hydrogen burner (11) is placed in the coal-fired boiler (3) in the area of ​​the pulverized coal nozzle on the furnace arch, or above the uppermost secondary air nozzle (21); the methanol burner (9) is arranged in the side wall area at the same height as the pulverized coal nozzle; when the coal-fired boiler (3) is a front and rear wall opposed boiler, the hydrogen burner (11) is located at the lowest The layer burnout air and the top layer pulverized coal burner (10) are arranged on the side wall at the same height as the two layers of pulverized coal burners (10) below; the methanol burner (9) is arranged between any two adjacent pulverized coal burners (10); when the coal-fired boiler (3) is a circulating fluidized bed boiler, the hydrogen burner (11) is located at the height of the coal-spreading air on the front and rear walls or between the coal-spreading air and the lower secondary air; the methanol burner (9) is arranged between any two adjacent coal-spreading air nozzles; Considering the location of the hydrogen burner (11) and the location of oxygen co-firing, when the coal-fired boiler (3) is a tangentially shaped boiler, if the hydrogen burner (11) is located below the primary air nozzle (17) of any one of the four corner layers A, B, C, D, E, F, or below any combination of 2-3 primary air nozzles (17) of layers A, B, C, D, E, F, then oxygen is co-fired into the secondary air nozzle (21) of the adjacent one or two layers; if the hydrogen burner (11) is located between the secondary air nozzle (21) of layer FF and the SOFA air nozzle, then oxygen is co-fired only into the primary air nozzle (17); when the coal-fired boiler (3) is a W-type flame boiler, if the hydrogen burner (11) is located inside the coal-fired boiler (3)... If the placement of the hydrogen burner (11) is in the coal pulverized air nozzle area on the furnace arch, then oxygen is mixed into the coal pulverized air nozzle; if the hydrogen burner (11) is arranged above the uppermost secondary air nozzle (21), then oxygen is mixed into the coal pulverized air nozzle; when the coal-fired boiler (3) is a front and rear wall opposed boiler, and the hydrogen burner (11) is located between the lowermost burnout air and the uppermost coal pulverized air burner (10), then oxygen is mixed into the primary air or secondary air; if the hydrogen burner (11) is located on the side wall at the same height as the lower two coal pulverized air burners (10), then oxygen is mixed into the lower two coal pulverized air burners (10); when the coal-fired boiler (3) is a circulating fluidized bed boiler, oxygen is mixed into the fluidized air box, the coal spreading air nozzle, or the upper secondary air nozzle (21). When considering the location of oxygen co-firing without regard to the position of hydrogen burner (11), when the coal-fired boiler (3) is a tangential boiler, all oxygen is co-fired into the bottom layer or the bottom two layers of primary air, or into the next layer, the next two layers or the next three layers of secondary air, or into the next 1-2 layers of primary air and the next 1-3 layers of secondary air respectively; when the coal-fired boiler (3) is a W-type flame boiler, all oxygen is co-fired into the pulverized coal nozzle, or into the next 1-2 layers of secondary air, or into the pulverized coal nozzle and any one layer of secondary air; when the coal-fired boiler (3) is a front and rear wall opposed boiler, all oxygen is co-fired into the next 1-2 layers of pulverized coal burners (10), or into the burnout air; when the coal-fired boiler (3) is a circulating fluidized bed boiler, all oxygen is co-fired into the coal spreading air, or into the two layers of secondary air, or into the fluidized air box.

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