Integrated energy system coupling wind-solar-thermal-storage with water electrolysis-based hydrogen production

Abstract

The present application relates to an integrated energy system coupling wind-solar-thermal-storage with water electrolysis-based hydrogen production, comprising: a wind-solar power generation unit, a thermal power generation unit, an energy storage unit, a hybrid hydrogen production unit, an air separation unit, an ammonia synthesis unit, a flue gas carbon capture unit, a methanol synthesis unit, an oxygen-enriched combustion unit, and an ammonia-doped combustion unit. In the integrated energy system coupling wind-solar-thermal-storage with water electrolysis-based hydrogen production, integrated coordinated operation of wind-solar-thermal-storage in combination with hydrogen production, ammonia production and alcohol production processes facilitates peak shaving, frequency regulation and voltage control, and ensures the stability and safety of a power system. Power generation from wind, solar and other renewable energy in combination with water electrolysis-based hydrogen production enables the production of cost-effective green hydrogen, utilizes surplus wind and solar resources, and reduces the phenomenon of wind and solar curtailment. Hybrid hydrogen production technology can effectively solve the problems of the intermittency and variability of wind and solar energy and the coupling between the wind and solar energy and hydrogen production equipment, achieve flexible hydrogen production, improve the efficiency of wind-solar power utilization, and enhance the overall stability of the system.

Description

Integrated energy system combining wind, solar, thermal, and energy storage with water electrolysis for hydrogen production. Technical Field

[0001] This application relates to the field of energy system technology, and in particular to an integrated energy system that combines wind, solar, thermal, and energy storage with water electrolysis to produce hydrogen. Background Technology

[0002] Large-scale development of renewable energy is crucial for reducing carbon emissions. However, due to its volatility and intermittency, existing wind and solar power generation faces severe curtailment issues, and single energy storage technologies are insufficient to significantly improve energy efficiency. Converting surplus wind and solar resources into hydrogen energy is considered an ideal solution, but the current hydrogen energy consumption industry chain is still underdeveloped. Simultaneously, large-scale grid integration of renewable energy poses significant challenges to grid stability and security, necessitating flexible retrofitting of thermal power plants to support deep peak shaving and low-carbon transformation through ammonia blending for combustion to significantly reduce carbon emissions. In this context, utilizing renewable energy to produce ammonia can not only solve the hydrogen consumption problem but also provide a green and economical ammonia source for ammonia blending in thermal power plants, enabling on-site ammonia consumption. Furthermore, capturing carbon dioxide emissions from thermal power plants through carbon capture technology and using it to synthesize methanol can effectively reduce carbon emissions and achieve downstream utilization of carbon resources. Integrated operation of wind, solar, thermal, and energy storage systems, combined with hydrogen, ammonia, and methanol production processes, helps ensure the stability and security of the power system and achieve efficient consumption of wind and solar resources and near-zero carbon emissions. Summary of the Invention

[0003] Therefore, it is necessary to provide an integrated energy system that combines wind, solar, thermal, and energy storage with water electrolysis to produce hydrogen.

[0004] This application provides an integrated energy system for hydrogen production by electrolysis of water using a combination of wind, solar, thermal, and energy storage, comprising: a wind and solar power generation unit, a thermal power generation unit, an energy storage unit, a hybrid hydrogen production unit, an air separation unit, an ammonia synthesis unit, a flue gas carbon capture unit, a methanol synthesis unit, an oxygen-enriched combustion unit, and an ammonia-blended combustion unit.

[0005] The wind and solar power generation unit, the thermal power generation unit, and the energy storage unit are all connected to the energy storage unit, and together they supply power to the external power grid and the internal system. The hybrid hydrogen production unit is connected to the wind and solar power generation unit, and uses wind and solar power to electrolyze water to produce hydrogen and oxygen. The air separation unit uses air to produce nitrogen and oxygen. The air separation unit and the hybrid hydrogen production unit are both connected to the ammonia synthesis unit, which uses nitrogen and hydrogen as raw materials to synthesize ammonia. Ammonia; the flue gas carbon capture unit is connected to the thermal power generation unit, and the flue gas carbon capture unit is used to capture carbon dioxide in the flue gas; both the flue gas carbon capture unit and the mixed hydrogen production unit are connected to the methanol synthesis unit, and the methanol synthesis unit uses carbon dioxide and hydrogen as raw materials to synthesize methanol; both the oxygen-enriched combustion unit and the ammonia-blended combustion unit are connected to the thermal power generation unit, the oxygen-enriched combustion unit is used to realize oxygen-enriched combustion in the thermal power generation unit, and the ammonia-blended combustion unit is used to realize ammonia-blended combustion in the thermal power generation unit.

[0006] In some embodiments, the wind and solar power generation unit includes a photovoltaic array and a wind turbine; the thermal power generation unit includes a boiler; the energy storage unit includes an energy storage device; the hybrid hydrogen production unit includes a power control device; the photovoltaic array and the power control device are connected, and the photovoltaic array is used to provide electrical energy to the hybrid hydrogen production unit; the wind turbine is connected to the power control device after passing through a rectifier, and the wind turbine is used to provide electrical energy to the hybrid hydrogen production unit; the photovoltaic array, the wind turbine, and the boiler are all connected to the energy storage device.

[0007] In some embodiments, the hybrid hydrogen production unit further includes an alkaline electrolyzer, a proton exchange membrane electrolyzer, an oxygen compressor, a hydrogen compressor, an oxygen storage tank, and a hydrogen storage tank. The alkaline electrolyzer and the proton exchange membrane electrolyzer are both connected to the power control device. The alkaline electrolyzer and the proton exchange membrane electrolyzer are used to produce hydrogen from wind and solar power loads with different fluctuation characteristics. The power control device is used to distribute the wind and solar power loads to the alkaline electrolyzer and the proton exchange membrane electrolyzer. The oxygen compressor and the hydrogen compressor are both simultaneously connected to the alkaline electrolyzer and the proton exchange membrane electrolyzer. The oxygen compressor is used to pressurize oxygen to the storage pressure, and the hydrogen compressor is used to pressurize hydrogen to the pressure required for the reaction section. The oxygen storage tank is connected to the oxygen compressor and is used to regulate the oxygen supply to the oxygen-enriched combustion unit. The hydrogen storage tank is connected to the hydrogen compressor and is used to distribute and regulate the hydrogen supply to the ammonia synthesis unit and the methanol synthesis unit.

[0008] In some embodiments, the alkaline electrolyzer has a DC hydrogen production energy consumption of 4.0 kWh / Nm³. 3 ~4.3kWh / Nm 3 The current density is 6000 A / m 2 ~7000A / m 2 The chamber voltage is 1.8V to 2.0V, and the hydrogen purity is ≥99.7%.

[0009] The proton exchange membrane electrolyzer has a DC hydrogen production energy consumption of 3.8 kWh / Nm³. 3 ~4.0kWh / Nm 3 The current density is 7000 A / m 2 ~8000A / m 2 The chamber voltage is 1.8V to 2.0V, and the hydrogen purity is ≥99.9%.

[0010] In some embodiments, the air separation unit includes an air separation device, a nitrogen compressor, and a nitrogen storage tank connected in sequence; the air separation device is connected to the oxygen storage tank, and the air separation device produces nitrogen and oxygen from air; the nitrogen compressor is used to pressurize the nitrogen to the pressure required by the reaction section; and the nitrogen storage tank is used to regulate the nitrogen supply to the ammonia synthesis unit.

[0011] In some embodiments, the ammonia synthesis unit includes an ammonia synthesis reaction device, an ammonia compressor, and an ammonia storage tank connected in sequence; the ammonia synthesis reaction device is connected to the hydrogen storage tank and the nitrogen storage tank, and the ammonia synthesis reaction device uses hydrogen and nitrogen to synthesize ammonia; the ammonia compressor is used to liquefy ammonia; and the ammonia storage tank is used to regulate the ammonia supply to the ammonia-blended combustion unit.

[0012] In some embodiments, the ammonia synthesis reactor operates at a temperature of 400°C to 500°C, a pressure of 15 MPa to 30 MPa, a hydrogen to nitrogen volume ratio of (3 to 3.2):1, and an ammonia selectivity of 95% to 98%.

[0013] In some embodiments, the flue gas carbon capture unit includes an absorption tower, a regeneration tower, and a carbon dioxide storage tank connected in sequence; the absorption tower is connected to the boiler; the flue gas emitted from the boiler is subjected to carbon dioxide capture through the absorption tower and the regeneration tower; the carbon dioxide storage tank is used to regulate the carbon dioxide supply of the methanol synthesis unit; the absorption tower and the regeneration tower are connected by a lean-rich liquid circulation system, which contains a carbon dioxide absorbent; the flue gas carbon capture unit also includes a water washing device connected to the absorption tower.

[0014] In some embodiments, the methanol synthesis unit includes a methanol synthesis reactor and a methanol storage tank connected in sequence. The methanol synthesis reactor is connected to the hydrogen storage tank and the carbon dioxide storage tank. The methanol synthesis reactor uses hydrogen and carbon dioxide to synthesize methanol. The methanol storage tank is used to store methanol.

[0015] In some embodiments, the methanol synthesis reactor operates at a temperature of 220°C to 250°C, a pressure of 6 MPa to 8 MPa, a hydrogen to carbon dioxide volume ratio of (3 to 5):1, and a methanol selectivity of 90% to 98%.

[0016] In the aforementioned integrated energy system combining wind, solar, thermal, and energy storage with water electrolysis for hydrogen production, the integrated operation of wind, solar, thermal, and energy storage, combined with hydrogen, ammonia, and methanol production processes, facilitates peak shaving, frequency regulation, and voltage regulation, ensuring the stability and security of the power system. Utilizing renewable energy sources such as wind and solar power generation in conjunction with water electrolysis for hydrogen production can produce economically viable green hydrogen, absorbing excess wind and solar resources and reducing wind and solar curtailment. Hybrid hydrogen production technology can effectively address the coupling issues between the intermittency and volatility of wind and solar power and hydrogen production equipment, achieving flexible hydrogen production, improving the efficiency of wind and solar power utilization, and enhancing the overall stability of the system. The hydrogen produced by water electrolysis can be combined with nitrogen separated from the air to produce ammonia, which is then supplied to thermal power units for ammonia-blended combustion, achieving on-site utilization and solving the hydrogen utilization problem. The hydrogen produced by water electrolysis can also be combined with carbon dioxide captured from the flue gas of thermal power units to produce high-value-added methanol, providing a direction for the downstream utilization of carbon dioxide captured by power plants, achieving carbon emission reduction and carbon dioxide resource utilization. The oxygen produced by the electrolysis of water and the separation of air can provide an economical source of oxygen for oxygen-enriched combustion in thermal power units, while also improving the operational flexibility of the units and enhancing their peak-shaving capabilities. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the integrated energy system for hydrogen production by electrolysis of water coupled with wind, solar, thermal, and energy storage according to an embodiment of this application;

[0018] Figure 2 is a schematic diagram of the structure of an integrated energy system for hydrogen production by coupling wind, solar, thermal, and energy storage with water electrolysis, according to another embodiment of this application.

[0019] Explanation of reference numerals in the attached figures

[0020] 10. Wind and solar power generation unit; 11. Photovoltaic array; 12. Wind turbine; 20. Thermal power generation unit; 21. Boiler; 30. Energy storage unit; 31. Energy storage device; 40. Hybrid hydrogen production unit; 41. Power control device; 42. Alkaline electrolyzer; 43. Proton exchange membrane electrolyzer; 44. Oxygen compressor; 45. Hydrogen compressor; 46. Oxygen storage tank; 47. Hydrogen storage tank; 50. Air separation unit; 51. Air separation device; 52. Nitrogen compressor. 53. Nitrogen storage tank; 60. Ammonia synthesis unit; 61. Ammonia synthesis reaction apparatus; 62. Ammonia compressor; 63. Ammonia storage tank; 70. Flue gas carbon capture unit; 71. Absorption tower; 72. Water washing equipment; 73. Regeneration tower; 74. Carbon dioxide storage tank; 80. Methanol synthesis unit; 81. Methanol synthesis reaction apparatus; 82. Methanol storage tank; 90. Oxygen-enriched combustion unit; 91. Oxygen-enriched burner; 100. Ammonia-blended combustion unit; 101. Ammonia-blended burner. Detailed Implementation

[0021] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided below. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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 this application.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] Referring to Figure 1, one embodiment of this application provides an integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis, including: a wind and solar power generation unit 10, a thermal power generation unit 20, an energy storage unit 30, a hybrid hydrogen production unit 40, an air separation unit 50, an ammonia synthesis unit 60, a flue gas carbon capture unit 70, a methanol synthesis unit 80, an oxygen-enriched combustion unit 90, and an ammonia-blended combustion unit 100. The wind and solar power generation unit 10 and the thermal power generation unit 20 are both connected to the energy storage unit 30, and together they supply power to the external power grid and the internal system. The hybrid hydrogen production unit 40 is connected to the wind and solar power generation unit 10, and utilizes wind and solar power to electrolyze water to produce hydrogen and oxygen. The air separation unit 50 utilizes air to produce nitrogen and oxygen. Both the air separation unit 50 and the hybrid hydrogen production unit 40 are connected to the ammonia synthesis unit 60, which synthesizes ammonia using nitrogen and hydrogen as raw materials. The flue gas carbon capture unit 70 is connected to the thermal power generation unit 20, and is used to capture carbon dioxide from the flue gas. Both the flue gas carbon capture unit 70 and the mixed hydrogen production unit 40 are connected to the methanol synthesis unit 80, which synthesizes methanol using carbon dioxide and hydrogen as raw materials. The oxygen-enriched combustion unit 90 and the ammonia-blended combustion unit 100 are both connected to the thermal power generation unit 20. The oxygen-enriched combustion unit 90 is used to achieve oxygen-enriched combustion in the thermal power generation unit 20, and the ammonia-blended combustion unit 100 is used to achieve ammonia-blended combustion in the thermal power generation unit 20.

[0027] In the aforementioned integrated energy system combining wind, solar, thermal, and energy storage with water electrolysis for hydrogen production, the integrated operation of wind, solar, thermal, and energy storage, combined with hydrogen, ammonia, and methanol production processes, facilitates peak shaving, frequency regulation, and voltage regulation, ensuring the stability and security of the power system. Utilizing renewable energy sources such as wind and solar power generation in conjunction with water electrolysis for hydrogen production can produce economically viable green hydrogen, absorbing excess wind and solar resources and reducing wind and solar curtailment. Hybrid hydrogen production technology can effectively address the coupling issues between the intermittency and volatility of wind and solar power and hydrogen production equipment, achieving flexible hydrogen production, improving the efficiency of wind and solar power utilization, and enhancing the overall stability of the system. The hydrogen produced by water electrolysis can be combined with nitrogen separated from the air to produce ammonia, which is then supplied to thermal power units for ammonia-blended combustion, achieving on-site utilization and solving the hydrogen utilization problem. The hydrogen produced by water electrolysis can also be combined with carbon dioxide captured from the flue gas of thermal power units to produce high-value-added methanol, providing a direction for the downstream utilization of carbon dioxide captured by power plants, achieving carbon emission reduction and carbon dioxide resource utilization. The oxygen produced by the electrolysis of water and the separation of air can provide an economical source of oxygen for oxygen-enriched combustion in thermal power units, while also improving the operational flexibility of the units and enhancing their peak-shaving capabilities.

[0028] Specifically, the wind and solar power generation unit 10, the thermal power generation unit 20, and the energy storage unit 30 are connected to the external power grid via transmission cables to provide the power required for the operation of the system equipment. The thermal power generation unit 20 serves as the baseload power source. The wind, solar, thermal, and energy storage units operate in conjunction to achieve peak shaving and valley filling, peak regulation, frequency regulation, and voltage regulation, thus solving the problems of variable load operation of thermal power units and the curtailment of wind and solar power. The wind and solar power generation unit 10 is connected to the hybrid hydrogen production unit 40 to provide the electrical energy required for hydrogen production through water electrolysis. The hybrid hydrogen production unit 40 uses demineralized water as raw material to electrolyze water into hydrogen and oxygen. It has an oxygen output terminal and a hydrogen output terminal. The oxygen output terminal is connected to the oxygen-enriched combustion unit 90 to provide the oxygen required for oxygen-enriched combustion. The hydrogen output terminal is connected to the ammonia synthesis unit 60 to provide the hydrogen required for ammonia synthesis. The hydrogen output terminal is connected to the methanol synthesis unit 80 to provide the hydrogen required for methanol synthesis. Air separation unit 50 uses air as raw material to separate it into oxygen and nitrogen. It has oxygen and nitrogen output terminals. The nitrogen output terminal is connected to ammonia synthesis unit 60 to provide the nitrogen needed for ammonia synthesis, and the oxygen output terminal is connected to oxygen-enriched combustion unit 90 to provide the oxygen needed for oxygen-enriched combustion. Ammonia synthesis unit 60 produces ammonia using hydrogen and nitrogen as raw materials. Flue gas carbon capture unit 70 is connected to thermal power generation unit 20 to capture carbon from the flue gas emitted by the thermal power unit, producing high-purity carbon dioxide. Flue gas carbon capture unit 70 is also connected to methanol synthesis unit 80 to provide the carbon dioxide needed for methanol synthesis. Methanol synthesis unit 80 produces methanol using hydrogen and carbon dioxide as raw materials. Oxygen-enriched combustion unit 90 is connected to thermal power generation unit 20 and performs oxygen-enriched combustion within boiler 21. Ammonia-blended combustion unit 100 is connected to thermal power generation unit 20 and performs ammonia-blended combustion within boiler 21.

[0029] Referring to FIG2, in some embodiments, the wind and solar power generation unit 10 includes a photovoltaic array 11 and a wind turbine 12. The thermal power generation unit 20 includes a boiler 21. The energy storage unit 30 includes an energy storage device 31. The hybrid hydrogen production unit 40 includes a power control device 41. The photovoltaic array 11 and the power control device 41 are connected, and the photovoltaic array 11 is used to provide electrical energy to the hybrid hydrogen production unit 40. The wind turbine 12 is connected to the power control device 41 after passing through a rectifier, and the wind turbine 12 is used to provide electrical energy to the hybrid hydrogen production unit 40. The photovoltaic array 11, the wind turbine 12, and the boiler 21 are all connected to the energy storage device 31.

[0030] Specifically, the wind and solar power generation unit 10 includes a photovoltaic array 11 and a wind turbine 12. The photovoltaic array 11 and the wind turbine 12 are connected to the power control device 41 of the hybrid hydrogen production unit 40. The AC power generated by the wind turbine 12 is rectified and filtered by an AC / DC rectifier and converted into DC power, which, along with the DC power generated by the photovoltaic array 11, is supplied to the hybrid hydrogen production unit 40 to provide the electrical energy required for water electrolysis. The thermal power generation unit 20 includes a boiler 21, which supplies power to the external power grid through transmission cables, while ensuring the safe start-up and shutdown of each unit in the integrated energy system when wind and solar power output is insufficient. The energy storage unit 30 includes an energy storage device 31, which is connected to the wind and solar power generation unit 10, the thermal power generation unit 20, and the external power grid through transmission cables. The combined operation of wind, solar, thermal, and energy storage plays a role in peak shaving, frequency regulation, and voltage regulation, shortening the response time of thermal power units and reducing wind and solar curtailment rates, thereby ensuring the safe and stable operation of the power system.

[0031] Referring again to Figure 2, in some embodiments, the mixed hydrogen production unit 40 further includes an alkaline electrolyzer 42, a proton exchange membrane electrolyzer 43, an oxygen compressor 44, a hydrogen compressor 45, an oxygen storage tank 46, and a hydrogen storage tank 47. The alkaline electrolyzer 42 and the proton exchange membrane electrolyzer 43 are both connected to a power control device 41. The alkaline electrolyzer 42 and the proton exchange membrane electrolyzer 43 are used to produce hydrogen from wind and solar power loads with different fluctuation characteristics. The power control device 41 is used to distribute the wind and solar power loads to the alkaline electrolyzer 42 and the proton exchange membrane electrolyzer 43. The oxygen compressor 44 and the hydrogen compressor 45 are both connected to both the alkaline electrolyzer 42 and the proton exchange membrane electrolyzer 43. The oxygen compressor 44 is used to pressurize oxygen to the storage pressure, and the hydrogen compressor 45 is used to pressurize hydrogen to the pressure required for the reaction section. The oxygen storage tank 46 is connected to the oxygen compressor 44 and is used to regulate the oxygen supply to the oxygen-enriched combustion unit 90. Hydrogen storage tank 47 is connected to hydrogen compressor 45 and is used to distribute and regulate the hydrogen supply to ammonia synthesis unit 60 and methanol synthesis unit 80.

[0032] Specifically, the power control device 41 allocates wind and solar power loads. The alkaline electrolyzer 42 and proton exchange membrane electrolyzer 43 are used to electrolyze water to produce hydrogen from wind and solar power loads with different fluctuation characteristics. Wind and solar power loads with lower fluctuation rates are allocated to the alkaline electrolyzer 42 for utilization, while those with higher fluctuation rates are allocated to the proton exchange membrane electrolyzer 43 for utilization. After purification and separation, oxygen and hydrogen are produced. The oxygen compressor 44 compresses oxygen to a certain pressure and sends it to the oxygen storage tank 46 for storage. The oxygen storage tank 46 is used for oxygen filling and discharging, adjusting the oxygen flow rate to meet the needs of the oxygen-enriched combustion unit 90. The hydrogen compressor 45 compresses hydrogen to a certain pressure and sends it to the hydrogen storage tank 47 for storage. The hydrogen storage tank 47 is used for hydrogen filling and discharging, adjusting and distributing the hydrogen flow rate to meet the needs of the ammonia synthesis unit 60 and the methanol synthesis unit 80.

[0033] In some embodiments, the hydrogen production DC energy consumption of the alkaline electrolyzer 42 is 4.0 kWh / Nm³. 3 ~4.3kWh / Nm 3 The current density is 6000 A / m 2 ~7000A / m 2 The chamber voltage is 1.8V to 2.0V, and the hydrogen purity is ≥99.7%. The DC energy consumption for hydrogen production in the proton exchange membrane electrolyzer 43 is 3.8kWh / Nm³. 3 ~4.0kWh / Nm 3 The current density is 7000 A / m 2 ~8000A / m 2 The chamber voltage is 1.8V to 2.0V, and the hydrogen purity is ≥99.9%.

[0034] Optionally, the DC energy consumption for hydrogen production in the alkaline electrolyzer 42 is 4.0 kWh / Nm³. 3 4.1 kWh / Nm 3 4.2 kWh / Nm 3 Or 4.3 kWh / Nm 3 Alternatively, the DC energy consumption for hydrogen production in the alkaline electrolyzer 42 can also be within the range of any two of the above DC energy consumption values.

[0035] Optionally, the current density of the alkaline electrolytic cell 42 is 6000 A / m. 2 6200A / m 2 6400A / m 2 6600A / m 2 6800A / m 2 Or 7000A / m 2 Alternatively, the current density of the alkaline electrolytic cell 42 can also be within the range of any two of the above current densities.

[0036] Optionally, the cell voltage of the alkaline electrolytic cell 42 is 1.8V, 1.85V, 1.9V, 1.95V, or 2.0V, or the cell voltage of the alkaline electrolytic cell 42 may be within the range of any two of the above cell voltages.

[0037] Optionally, the hydrogen production DC energy consumption of the proton exchange membrane electrolyzer 43 is 3.8 kWh / Nm³. 3 3.85 kWh / Nm 3 3.9kWh / Nm 3 3.95 kWh / Nm 3 4.0 kWh / Nm 3 Alternatively, the DC energy consumption for hydrogen production in the proton exchange membrane electrolyzer 43 can also be within the range of any two of the above DC energy consumptions.

[0038] Optionally, the current density of the proton exchange membrane electrolyzer 43 is 7000 A / m. 2 7200A / m 2 7400A / m 2 7600A / m 2 7800A / m 2 Or 8000A / m 2 Alternatively, the current density of the proton exchange membrane electrolyzer 43 can also be within the range of any two of the above current densities.

[0039] Optionally, the cell voltage of the proton exchange membrane electrolyzer 43 is 1.8V, 1.85V, 1.9V, 1.95V, or 2.0V, or the cell voltage of the proton exchange membrane electrolyzer 43 may be within the range of any two of the above cell voltages.

[0040] Referring again to Figure 2, in some embodiments, the air separation unit 50 includes an air separation device 51, a nitrogen compressor 52, and a nitrogen storage tank 53 connected in sequence. The air separation device 51 is connected to the oxygen storage tank 46, and the air separation device 51 produces nitrogen and oxygen from air. The nitrogen compressor 52 is used to pressurize the nitrogen to the pressure required for the reaction section. The nitrogen storage tank 53 is used to regulate the nitrogen supply to the ammonia synthesis unit 60.

[0041] Specifically, the air separation unit 50 includes an air separation device 51, a nitrogen compressor 52, and a nitrogen storage tank 53 connected in sequence. The air separation device 51 uses air as raw material and turns the air into liquid through a compression cycle deep freezing method. Then, nitrogen and oxygen are gradually separated from the liquid air through distillation. The nitrogen compressor 52 compresses the nitrogen to a certain pressure and sends it to the nitrogen storage tank 53 for storage. The nitrogen storage tank 53 is used for nitrogen filling and releasing, and adjusting the nitrogen flow rate to meet the needs of the ammonia synthesis unit 60. Oxygen is compressed to a certain pressure by the oxygen compressor 44 and sent to the oxygen storage tank 46.

[0042] Referring again to Figure 2, in some embodiments, the ammonia synthesis unit 60 includes an ammonia synthesis reactor 61, an ammonia compressor 62, and an ammonia storage tank 63 connected in sequence. The ammonia synthesis reactor 61 is connected to a hydrogen storage tank 47 and a nitrogen storage tank 53, and utilizes hydrogen and nitrogen to synthesize ammonia. The ammonia compressor 62 is used to liquefy the ammonia. The ammonia storage tank 63 is used to regulate the ammonia supply to the ammonia-blended combustion unit 100.

[0043] Specifically, the ammonia synthesis unit 60 includes an ammonia synthesis reaction device 61, an ammonia compressor 62, and an ammonia storage tank 63 connected in sequence. The hydrogen in the hydrogen storage tank 47 connected to the ammonia synthesis reaction device 61 and the nitrogen in the nitrogen storage tank 53 are mixed and then compressed in stages by the compressor. Ammonia synthesis and condensation separation are completed through two-stage ammonia cooling and secondary ammonia separation. Finally, the synthesized ammonia is sent to the ammonia storage tank 63 for storage by compression and refrigeration by the ammonia compressor 62. The nitrogen storage tank 53 is used for nitrogen charging and discharging, and the nitrogen flow rate is adjusted to meet the needs of the ammonia-blended combustion unit 100.

[0044] In some embodiments, the ammonia synthesis reactor 61 operates at a temperature of 400°C to 500°C, a pressure of 15 MPa to 30 MPa, a hydrogen to nitrogen volume ratio of (3 to 3.2):1, and an ammonia selectivity of 95% to 98%.

[0045] Optionally, the operating temperature of the ammonia synthesis reaction apparatus 61 is 400°C, 420°C, 440°C, 460°C, 480°C, or 500°C, or the operating temperature of the ammonia synthesis reaction apparatus 61 may be within the range of any two of the above operating temperatures.

[0046] Optionally, the working pressure of the ammonia synthesis reactor 61 is 15 MPa, 20 MPa, 25 MPa or 30 MPa, or the working pressure of the ammonia synthesis reactor 61 may be within the range of any two of the above working pressures.

[0047] Optionally, the volume ratio of hydrogen to nitrogen in the ammonia synthesis reactor 61 is 3:1, 3.05:1, 3.1:1, 3.15:1 or 3.2:1, or the volume ratio of hydrogen to nitrogen in the ammonia synthesis reactor 61 can also be within the range of any two of the above volume ratios.

[0048] Optionally, the ammonia selectivity of the ammonia synthesis reaction apparatus 61 is 95%, 96%, 97%, or 98%, or the ammonia selectivity of the ammonia synthesis reaction apparatus 61 may be within the range of any two of the above ammonia selectivity rates.

[0049] Referring again to Figure 2, in some embodiments, the flue gas carbon capture unit 70 includes an absorption tower 71, a regeneration tower 73, and a carbon dioxide storage tank 74 connected in sequence. The absorption tower 71 is connected to the boiler 21. The flue gas emitted from the boiler 21 undergoes carbon dioxide capture through the absorption tower 71 and the regeneration tower 73. The carbon dioxide storage tank 74 is used to regulate the carbon dioxide supply to the methanol synthesis unit 80. The absorption tower 71 and the regeneration tower 73 are connected via a lean-rich liquor circulation system, which contains a carbon dioxide absorbent. The flue gas carbon capture unit 70 also includes a water washing device 72 connected to the absorption tower 71.

[0050] Specifically, the flue gas carbon capture unit 70 includes an absorption tower 71, a regeneration tower 73, and a carbon dioxide storage tank 74 connected in sequence. The flue gas pipeline discharged from the boiler 21 is connected to the absorption tower 71. A water washing device 72 is integrated at the top of the absorption tower 71. The absorption tower 71 and the regeneration tower 73 are connected through a lean-rich liquid circulation system. After pretreatment, the flue gas enters the absorption tower 71 and forms a countercurrent contact with the absorbent. The decarbonized flue gas is discharged from the top of the absorption tower 71 through the water washing device 72. The absorbent for absorbing CO2 is a rich liquid. After being heated by the lean-rich liquid heat exchanger, it enters the regeneration tower 73 to desorb CO2. The desorbed CO2, along with water vapor, is cooled and the water is removed to obtain carbon dioxide. The absorbent for desorbing CO2 is a lean liquid. It flows out from the bottom of the regeneration tower 73, is heated by the lean-rich liquid heat exchanger, and then enters the absorption tower 71 to circulate and absorb CO2. The regeneration tower 73 is connected to the carbon dioxide storage tank 74, which is used for carbon dioxide charging and discharging to regulate the carbon dioxide flow rate to meet the needs of the methanol synthesis unit 80.

[0051] Referring again to Figure 2, in some embodiments, the methanol synthesis unit 80 includes a methanol synthesis reactor 81 and a methanol storage tank 82 connected in sequence. The methanol synthesis reactor 81 is connected to a hydrogen storage tank 47 and a carbon dioxide storage tank 74. The methanol synthesis reactor 81 uses hydrogen and carbon dioxide to synthesize methanol. The methanol storage tank 82 is used to store methanol.

[0052] Specifically, the methanol synthesis unit 80 includes a methanol synthesis reaction device 81 and a methanol storage tank 82 connected in sequence. The methanol synthesis reaction device 81 is connected to a hydrogen storage tank 47 and a carbon dioxide storage tank 74. After hydrogen and carbon dioxide are introduced into the methanol synthesis reaction device 81, gaseous methanol is synthesized. The gaseous methanol is cooled by a cooler to obtain crude methanol. The crude methanol is separated and purified by a separator to obtain refined methanol. The refined methanol is sent to the methanol storage tank 82 for storage and will be used as a chemical raw material or fuel.

[0053] In some embodiments, the methanol synthesis reactor 81 operates at a temperature of 220°C to 250°C, an operating pressure of 6 MPa to 8 MPa, a hydrogen to carbon dioxide volume ratio of (3 to 5):1, and a methanol selectivity of 90% to 98%.

[0054] Optionally, the operating temperature of the methanol synthesis reactor 81 is 220°C, 230°C, 240°C or 250°C, or the operating temperature of the methanol synthesis reactor 81 may be within the range of any two of the above operating temperatures.

[0055] Optionally, the operating pressure of the methanol synthesis reactor 81 is 6 MPa, 6.5 MPa, 7 MPa, 7.5 MPa or 8 MPa, or the operating pressure of the methanol synthesis reactor 81 may be within the range of any two of the above operating pressures.

[0056] Optionally, the volume ratio of hydrogen to carbon dioxide in the methanol synthesis reactor 81 is 3:1, 3.5:1, 4:1, 4.5:1 or 5:1, or the volume ratio of hydrogen to carbon dioxide in the methanol synthesis reactor 81 can also be within the range of any two of the above-mentioned volume ratios of hydrogen to carbon dioxide.

[0057] Optionally, the methanol selectivity of the methanol synthesis reactor 81 is 90%, 92%, 94%, 96%, or 98%, or the methanol selectivity of the methanol synthesis reactor 81 may be within the range of any two of the above methanol selectivity rates.

[0058] Referring again to FIG2, in some embodiments, the oxygen-enriched combustion unit 90 includes an oxygen-enriched burner 91, which is connected to the oxygen storage tank 46.

[0059] Specifically, oxygen-enriched combustion refers to replacing air with pure oxygen in boiler 21 to improve the combustion stability and flexibility of boiler 21. The oxygen-enriched combustion unit 90 includes an oxygen-enriched burner 91, which is connected to an oxygen storage tank 46. Oxygen is depressurized by a pressure reducing valve and then fed into the oxygen-enriched burner 91 at a certain pressure. It has a primary oxygen inlet and a secondary oxygen inlet. The primary oxygen inlet uses a Laval nozzle structure, utilizing the negative pressure generated by the throat effect to draw back the flue gas and mix it with oxygen, thereby enhancing the fuel's ignition performance and improving combustion stability. The secondary oxygen inlet is deflected 15°–30° towards the axis, allowing the secondary oxygen to reach the center of the flame and fully mix with the fuel, improving the fuel's burnout rate. Different proportions of oxygen-enriched combustion are carried out within boiler 21.

[0060] Referring again to FIG2, in some embodiments, the ammonia-blended combustion unit 100 includes an ammonia-blended burner 101, wherein liquid ammonia in the ammonia storage tank 63 is fed into the ammonia-blended burner 101 in gaseous form after passing through an evaporation device.

[0061] Specifically, ammonia-blended combustion refers to the use of ammonia gas to partially replace coal in boiler 21 to reduce CO2 emissions. The ammonia-blended combustion unit 100 includes an ammonia-blended burner 101. Liquid ammonia from the ammonia storage tank 63 is fed into the ammonia-blended burner 101 in gaseous form after passing through an evaporation device. The burner has a first gas inlet and a second gas inlet. The first gas inlet contains a premixed lean gas of ammonia and air with an equivalence ratio of 0.6–1. The second gas inlet contains a premixed rich gas of ammonia and air with an equivalence ratio of 1–1.3. By adjusting the premixed gas equivalence ratio of the first and second gas inlets, the combustion state and NO emissions can be adjusted accordingly. x Emission concentrations are precisely controlled by ammonia-blended combustion in different proportions within boiler 21.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A comprehensive energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis, characterized in that: include: The unit includes wind and solar power generation, thermal power generation, energy storage, hybrid hydrogen production, air separation, ammonia synthesis, flue gas carbon capture, methanol synthesis, oxygen-enriched combustion, and ammonia-blended combustion. The wind and solar power generation unit, the thermal power generation unit, and the energy storage unit are all connected to the energy storage unit, and together they supply power to the external power grid and the internal system. The hybrid hydrogen production unit is connected to the wind and solar power generation unit, and uses wind and solar power to electrolyze water to produce hydrogen and oxygen. The air separation unit uses air to produce nitrogen and oxygen. The air separation unit and the hybrid hydrogen production unit are both connected to the ammonia synthesis unit, which uses nitrogen and hydrogen as raw materials to synthesize ammonia. Ammonia; the flue gas carbon capture unit is connected to the thermal power generation unit, and the flue gas carbon capture unit is used to capture carbon dioxide in the flue gas; both the flue gas carbon capture unit and the mixed hydrogen production unit are connected to the methanol synthesis unit, and the methanol synthesis unit uses carbon dioxide and hydrogen as raw materials to synthesize methanol; both the oxygen-enriched combustion unit and the ammonia-blended combustion unit are connected to the thermal power generation unit, the oxygen-enriched combustion unit is used to realize oxygen-enriched combustion in the thermal power generation unit, and the ammonia-blended combustion unit is used to realize ammonia-blended combustion in the thermal power generation unit.

2. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 1, characterized in that, The wind and solar power generation unit includes a photovoltaic array and a wind turbine; the thermal power generation unit includes a boiler; the energy storage unit includes an energy storage device; the hybrid hydrogen production unit includes a power control device; the photovoltaic array and the power control device are connected, and the photovoltaic array is used to provide power to the hybrid hydrogen production unit; the wind turbine is connected to the power control device after passing through a rectifier, and the wind turbine is used to provide power to the hybrid hydrogen production unit; The photovoltaic array, the wind turbine, and the boiler are all connected to the energy storage device.

3. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 2, characterized in that, The hybrid hydrogen production unit further includes an alkaline electrolyzer, a proton exchange membrane electrolyzer, an oxygen compressor, a hydrogen compressor, an oxygen storage tank, and a hydrogen storage tank. The alkaline electrolyzer and the proton exchange membrane electrolyzer are both connected to the power control device. The alkaline electrolyzer and the proton exchange membrane electrolyzer are used to produce hydrogen from wind and solar power loads with different fluctuation characteristics. The power control device is used to distribute the wind and solar power loads to the alkaline electrolyzer and the proton exchange membrane electrolyzer. The oxygen compressor and the hydrogen compressor are both simultaneously connected to the alkaline electrolyzer and the proton exchange membrane electrolyzer. The oxygen compressor is used to pressurize oxygen to the storage pressure, and the hydrogen compressor is used to pressurize hydrogen to the pressure required for the reaction section. The oxygen storage tank is connected to the oxygen compressor and is used to regulate the oxygen supply to the oxygen-enriched combustion unit. The hydrogen storage tank is connected to the hydrogen compressor and is used to distribute and regulate the hydrogen supply to the ammonia synthesis unit and the methanol synthesis unit.

4. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 3, is characterized in that, The hydrogen production DC energy consumption of the alkaline electrolyzer is 4.0 kWh / Nm³. 3 ~4.3kWh / Nm 3 The current density is 6000 A / m 2 ~7000A / m 2 The chamber voltage is 1.8V to 2.0V, and the hydrogen purity is ≥99.7%. The proton exchange membrane electrolyzer has a DC hydrogen production energy consumption of 3.8 kWh / Nm³. 3 ~4.0kWh / Nm 3 The current density is 7000 A / m 2 ~8000A / m 2 The chamber voltage is 1.8V to 2.0V, and the hydrogen purity is ≥99.9%.

5. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 3, characterized in that, The air separation unit includes an air separation device, a nitrogen compressor, and a nitrogen storage tank connected in sequence; the air separation device is connected to the oxygen storage tank, and the air separation device produces nitrogen and oxygen using air as raw material; The nitrogen compressor is used to pressurize nitrogen to the pressure required for the reaction section; the nitrogen storage tank is used to regulate the nitrogen supply to the ammonia synthesis unit.

6. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 5, is characterized in that, The ammonia synthesis unit includes an ammonia synthesis reaction device, an ammonia compressor, and an ammonia storage tank connected in sequence; the ammonia synthesis reaction device is connected to the hydrogen storage tank and the nitrogen storage tank, and the ammonia synthesis reaction device uses hydrogen and nitrogen to synthesize ammonia; the ammonia compressor is used to liquefy ammonia; and the ammonia storage tank is used to regulate the ammonia supply to the ammonia-blended combustion unit.

7. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 6, characterized in that, The ammonia synthesis reactor operates at a temperature of 400℃ to 500℃ and a pressure of 15MPa to 30MPa. The volume ratio of hydrogen to nitrogen is (3 to 3.2):1, and the ammonia selectivity is 95% to 98%.

8. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 3, is characterized in that, The flue gas carbon capture unit includes an absorption tower, a regeneration tower, and a carbon dioxide storage tank connected in sequence; the absorption tower is connected to the boiler; the flue gas emitted from the boiler is subjected to carbon dioxide capture through the absorption tower and the regeneration tower; the carbon dioxide storage tank is used to regulate the carbon dioxide supply of the methanol synthesis unit; the absorption tower and the regeneration tower are connected by a lean-rich liquid circulation system, which contains a carbon dioxide absorbent; the flue gas carbon capture unit also includes a water washing device connected to the absorption tower.

9. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 8, characterized in that, The methanol synthesis unit includes a methanol synthesis reaction device and a methanol storage tank connected in sequence. The methanol synthesis reaction device is connected to the hydrogen storage tank and the carbon dioxide storage tank. The methanol synthesis reaction device uses hydrogen and carbon dioxide to synthesize methanol. The methanol storage tank is used to store methanol.

10. The integrated energy system for hydrogen production via wind, solar, thermal, and energy storage coupled with water electrolysis as described in claim 9, characterized in that, The methanol synthesis reactor operates at a temperature of 220℃ to 250℃ and a pressure of 6MPa to 8MPa. The volume ratio of hydrogen to carbon dioxide is (3 to 5):1, and the methanol selectivity is 90% to 98%.

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