Wind-light-fire-storage coupled water electrolysis hydrogen production comprehensive energy system

Abstract

The invention relates to a wind-light-fire-storage coupled water electrolysis hydrogen production comprehensive energy system. The system comprises a wind-light power generation unit, a thermal power generation unit, an energy storage unit, a mixed hydrogen production unit, an air separation unit, an ammonia gas synthesis unit, a flue gas carbon capture unit, a methanol synthesis unit, an oxygen-enriched combustion unit and an ammonia-doped combustion unit. According to the wind-light-fire-storage coupled water electrolysis hydrogen production comprehensive energy system, wind-light-fire-storage integrated cooperative operation is achieved, hydrogen production, ammonia production and alcohol production processes are combined, peak regulation, frequency modulation and voltage regulation are facilitated, and the stability and safety of a power system are guaranteed. Power generation through renewable energy sources such as wind and light is combined with hydrogen production through water electrolysis, green hydrogen with economic cost can be produced, excessive wind and light resources are consumed, and the phenomenon of wind and light abandoning is reduced. The hybrid hydrogen production technology can effectively solve the problems of intermittency and volatility of wind and light and coupling between hydrogen production equipment, realizes flexible hydrogen production, improves the wind-light-electricity absorption efficiency, and enhances the overall stability of the system.

Description

Technical Field

[0001] The present application relates to the technical field of energy systems, and in particular to an integrated energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis. Background Art

[0002] Large-scale development of renewable energy is of great significance to reducing carbon emissions. However, due to its volatility and intermittency, existing wind and solar power generation faces serious problems of wind and solar abandonment, and a single energy storage technology is difficult to significantly improve energy efficiency. Converting excess wind and solar resources into hydrogen energy is seen as an ideal solution, but the current industrial chain for hydrogen energy consumption is still imperfect. At the same time, large-scale renewable energy grid connection poses a significant challenge to the stability and security of the power grid. It is urgent to support deep peak regulation through the flexibility transformation of thermal power generation and significantly reduce carbon emissions through the low-carbon transformation of ammonia combustion. In this context, the use of renewable energy to produce ammonia can not only solve the problem of hydrogen energy consumption, but also provide a green and economical source of ammonia for ammonia combustion of thermal power generation, and realize the local consumption of ammonia. In addition, carbon capture technology can be used to capture carbon dioxide emitted by thermal power and use it to synthesize methanol, which can effectively reduce carbon emissions and realize the downstream utilization of carbon resources. The integrated coordinated operation of wind, solar, thermal and storage, combined with hydrogen production, ammonia production and alcohol production processes, will help ensure the stability and security of the power system and achieve the efficient consumption of wind and solar resources and the goal of near-zero carbon emissions. Summary of the invention

[0003] Based on this, it is necessary to provide a comprehensive energy system that couples wind, solar, thermal and storage to produce hydrogen through water electrolysis.

[0004] The present application provides a comprehensive energy system for wind, solar, thermal and storage coupled electrolysis of water to produce hydrogen, including: 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-solar power generation unit and the thermal power generation unit are both connected to the energy storage unit, and the wind-solar power generation unit, the thermal power generation unit and the energy storage unit jointly supply power to the external power grid and the internal system; the hybrid hydrogen production unit is connected to the wind-solar power generation unit, and the hybrid hydrogen production unit utilizes wind and solar power to electrolyze water to produce hydrogen and oxygen; the air separation unit utilizes air to produce nitrogen and oxygen; the air separation unit and the hybrid hydrogen production unit are both connected to the ammonia synthesis unit, and the ammonia synthesis unit utilizes nitrogen and hydrogen as raw materials to synthesize 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; the flue gas carbon capture unit and the mixed hydrogen production unit are both connected to the methanol synthesis unit, and the methanol synthesis unit synthesizes methanol using carbon dioxide and hydrogen as raw materials; the oxygen-enriched combustion unit and the ammonia-blended combustion unit are both connected to the thermal power generation unit, and the oxygen-enriched combustion unit is used to realize oxygen-enriched combustion of the thermal power generation unit, and the ammonia-blended combustion unit is used to realize ammonia-blended combustion of the thermal power generation unit.

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

[0007] In some embodiments, the hybrid hydrogen production unit also 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, and the alkaline electrolyzer and the proton exchange membrane electrolyzer are used to carry wind and photovoltaic loads with different fluctuation characteristics to produce hydrogen; the power control device is used to distribute the wind and photovoltaic loads to the alkaline electrolyzer and the proton exchange membrane electrolyzer; the oxygen compressor and the hydrogen compressor are both connected to the alkaline electrolyzer and the proton exchange membrane electrolyzer at the same time; the oxygen compressor is used to boost the oxygen to the storage pressure, and the hydrogen compressor is used to boost the hydrogen to the pressure required by the reaction section; the oxygen storage tank is connected to the oxygen compressor, and the oxygen storage tank is used to adjust the oxygen supply of the oxygen-enriched combustion unit; the hydrogen storage tank is connected to the hydrogen compressor, and the hydrogen storage tank is used to distribute and adjust the hydrogen supply of the ammonia synthesis unit and the methanol synthesis unit.

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

[0009] The DC energy consumption of hydrogen production in the proton exchange membrane electrolyzer is 3.8 kWh / Nm 3 ~4.0kWh / Nm 3 , current density is 7000A / m 2 ~8000A / m 2 , the chamber voltage is 1.8V~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 uses air as a raw material to produce nitrogen and oxygen; the nitrogen compressor is used to pressurize the nitrogen to the pressure required by the reaction section; the nitrogen storage tank is used to adjust the nitrogen supply of 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 synthesizes ammonia by using hydrogen and nitrogen; the ammonia compressor is used to liquefy ammonia; and the ammonia storage tank is used to adjust the ammonia supply of the ammonia blending combustion unit.

[0012] In some of the embodiments, the operating temperature of the ammonia synthesis reaction device is 400°C~500°C, the operating pressure is 15MPa~30MPa, the volume ratio of hydrogen to nitrogen is (3~3.2):1, and the ammonia selectivity is 95%~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 discharged from the boiler passes through the absorption tower and the regeneration tower to capture carbon dioxide; the carbon dioxide storage tank is used to adjust the carbon dioxide supply of the methanol synthesis unit; the absorption tower and the regeneration tower are connected through a lean and rich liquid circulation system, and the lean and rich liquid circulation system contains a carbon dioxide absorbent; the flue gas carbon capture unit also includes a water washing device, and the water washing device is connected to the absorption tower.

[0014] In some embodiments, 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, and the methanol synthesis reaction device uses hydrogen and carbon dioxide to synthesize methanol; the methanol storage tank is used to store methanol.

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

[0016] In the above-mentioned wind, solar, thermal and storage coupled with water electrolysis hydrogen production integrated energy system, wind, solar, thermal and storage integrated coordinated operation, combined with hydrogen production, ammonia production and alcohol production processes, is conducive to peak load regulation, frequency regulation and voltage regulation, and ensures the stability and safety of the power system. The combination of wind, solar and other renewable energy power generation and water electrolysis hydrogen production can produce economically cost-effective green hydrogen, absorb excess wind and solar resources, and reduce the phenomenon of wind and solar abandonment. Hybrid hydrogen production technology can effectively solve the coupling problem between the intermittent and volatile wind and solar power and hydrogen production equipment, realize flexible hydrogen production, improve the efficiency of wind and solar power consumption, and enhance 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 supplied to thermal power units for ammonia-blended combustion, and local consumption is realized, solving the problem of hydrogen consumption. The hydrogen produced by water electrolysis can be combined with carbon dioxide captured from the flue gas discharged by thermal power units to produce high-value-added methanol, providing direction for the downstream utilization of carbon dioxide captured by power plants, and realizing carbon emission reduction and carbon dioxide resource utilization. The oxygen produced by electrolysis of water and air separation can provide an economical source of oxygen for oxygen-enriched combustion in thermal power units, while improving the operating flexibility of the units and enhancing their peak-shaving capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic diagram of the structure of an integrated energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis provided in one embodiment of the present application;

[0018] FIG2 is a schematic diagram of the structure of an integrated energy system for producing hydrogen by coupling wind, solar, thermal and storage with water electrolysis provided in another embodiment of the present application.

[0019] Description of Reference Numerals

[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 supply 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 compression machine; 53, nitrogen storage tank; 60, ammonia synthesis unit; 61, ammonia synthesis reaction device; 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 device; 82, methanol storage tank; 90, oxygen-enriched combustion unit; 91, oxygen-enriched burner; 100, ammonia-blended combustion unit; 101, ammonia-blended burner. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0023] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

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

[0025] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] As shown in FIG1 , an embodiment of the present application provides a comprehensive energy system for wind-solar-fire-storage coupled electrolysis of water to produce hydrogen, including: a wind-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-solar power generation unit 10 and the thermal power generation unit 20 are both connected to the energy storage unit 30, and the wind-solar power generation unit 10 and the thermal power generation unit 20 jointly supply power to the external power grid and the internal system. The hybrid hydrogen production unit 40 is connected to the wind-solar power generation unit 10, and the hybrid hydrogen production unit 40 uses wind and solar power to electrolyze water to produce hydrogen and oxygen. The air separation unit 50 uses air to produce nitrogen and oxygen. The air separation unit 50 and the hybrid hydrogen production unit 40 are both connected to the ammonia synthesis unit 60, and the ammonia synthesis unit 60 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 the flue gas carbon capture unit 70 is used to capture carbon dioxide in the flue gas. The flue gas carbon capture unit 70 and the hybrid hydrogen production unit 40 are both connected to the methanol synthesis unit 80, and the methanol synthesis unit 80 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, and the oxygen-enriched combustion unit 90 is used to realize the oxygen-enriched combustion of the thermal power generation unit 20, and the ammonia-blended combustion unit 100 is used to realize the ammonia-blended combustion of the thermal power generation unit 20.

[0027] In the above-mentioned wind, solar, thermal and storage coupled with water electrolysis hydrogen production integrated energy system, wind, solar, thermal and storage integrated coordinated operation, combined with hydrogen production, ammonia production and alcohol production processes, is conducive to peak load regulation, frequency regulation and voltage regulation, and ensures the stability and safety of the power system. The combination of wind, solar and other renewable energy power generation and water electrolysis hydrogen production can produce economically cost-effective green hydrogen, absorb excess wind and solar resources, and reduce the phenomenon of wind and solar abandonment. Hybrid hydrogen production technology can effectively solve the coupling problem between the intermittent and volatile wind and solar power and hydrogen production equipment, realize flexible hydrogen production, improve the efficiency of wind and solar power consumption, and enhance 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 supplied to thermal power units for ammonia-blended combustion, and local consumption is realized, solving the problem of hydrogen consumption. The hydrogen produced by water electrolysis can be combined with carbon dioxide captured from the flue gas discharged by thermal power units to produce high-value-added methanol, providing direction for the downstream utilization of carbon dioxide captured by power plants, and realizing carbon emission reduction and carbon dioxide resource utilization. The oxygen produced by electrolysis of water and air separation can provide an economical source of oxygen for oxygen-enriched combustion in thermal power units, while improving the operating flexibility of the units and enhancing their peak-shaving capabilities.

[0028] Specifically, the wind-solar power generation unit 10, the thermal power generation unit 20 and the energy storage unit 30 are connected to the external power grid through transmission cables to provide power and provide the power required for the operation of the system equipment. The thermal power generation unit 20 serves as a base load power source, and the wind-solar-thermal-storage unit operates jointly to achieve peak shaving and valley filling, peak-shaving, frequency regulation and voltage regulation, and solve the problems of variable load operation of thermal power units and abandonment of wind and light energy. The wind-solar power generation unit 10 is connected to the hybrid hydrogen production unit 40 to provide the power required for electrolysis of water to produce hydrogen. The hybrid hydrogen production unit 40 uses deionized water as a raw material to electrolyze water into hydrogen and oxygen, and has an oxygen output end and a hydrogen output end. The oxygen output end is connected to the oxygen-enriched combustion unit 90 to provide the oxygen required for oxygen-enriched combustion, and the hydrogen output end is connected to the ammonia synthesis unit 60 to provide the hydrogen required for synthesizing ammonia. The hydrogen output end is connected to the methanol synthesis unit 80 to provide the hydrogen required for synthesizing methanol. The air separation unit 50 uses air as a raw material to separate air into oxygen and nitrogen. It has an oxygen output end and a nitrogen output end. The nitrogen output end is connected to the ammonia synthesis unit 60 to provide nitrogen required for synthesizing ammonia. The oxygen output end is connected to the oxygen-enriched combustion unit 90 to provide oxygen required for oxygen-enriched combustion. The ammonia synthesis unit 60 produces ammonia using hydrogen and nitrogen as raw materials. The flue gas carbon capture unit 70 is connected to the thermal power generation unit 20 to capture carbon from the flue gas emitted by the thermal power unit to produce high-purity carbon dioxide; the flue gas carbon capture unit 70 is connected to the methanol synthesis unit 80 to provide carbon dioxide required for synthesizing methanol; the methanol synthesis unit 80 uses hydrogen and carbon dioxide as raw materials to produce methanol; the oxygen-enriched combustion unit 90 is connected to the thermal power generation unit 20 to perform oxygen-enriched combustion in the boiler 21. The ammonia blending combustion unit 100 is connected to the thermal power generation unit 20 to perform ammonia blending combustion in the boiler 21.

[0029] As shown in FIG2 , in some embodiments, the wind-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 supply control device 41. The photovoltaic array 11 is connected to the power supply control device 41, and the photovoltaic array 11 is used to provide electrical energy for the hybrid hydrogen production unit 40. The wind turbine 12 is connected to the power supply control device 41 after passing through a rectifier, and the wind turbine 12 is used to provide electrical energy for 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 generator 12, which are connected to the power control device 41 of the hybrid hydrogen production unit 40. The alternating current generated by the wind generator 12 is converted into direct current after rectification and filtering by the AC / DC rectifier, and is transmitted to the hybrid hydrogen production unit 40 with the direct current generated by the photovoltaic array 11 to provide the electric energy required for water electrolysis. The thermal power generation unit 20 includes a boiler 21, which supplies power to the external power grid through a transmission cable, and at the same time ensures the safe start and shutdown of each unit of the comprehensive energy system when the 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 a transmission cable. The wind, solar, thermal and storage are jointly operated to play the role of peak regulation, frequency regulation and voltage regulation, shorten the response time of the thermal power unit, and reduce the wind and light abandonment rate, thereby ensuring the safe and stable operation of the power system.

[0031] Referring again to FIG. 2 , in some embodiments, the hybrid 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 the power control device 41, and the alkaline electrolyzer 42 and the proton exchange membrane electrolyzer 43 are used to produce hydrogen by carrying wind and photovoltaic loads with different fluctuation characteristics. The power control device 41 is used to distribute the wind and photovoltaic 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 the alkaline electrolyzer 42 and the proton exchange membrane electrolyzer 43 at the same time. The oxygen compressor 44 is used to boost the oxygen to the storage pressure, and the hydrogen compressor 45 is used to boost the hydrogen to the pressure required by the reaction section. The oxygen storage tank 46 is connected to the oxygen compressor 44, and the oxygen storage tank 46 is used to adjust the oxygen supply of the oxygen-enriched combustion unit 90. The hydrogen storage tank 47 is connected to the hydrogen compressor 45 , and is used to distribute and regulate the hydrogen supply to the ammonia synthesis unit 60 and the methanol synthesis unit 80 .

[0032] Specifically, the power control device 41 distributes wind and photovoltaic loads, and the alkaline electrolyzer 42 and the proton exchange membrane electrolyzer 43 are used to carry wind and photovoltaic loads with different fluctuation characteristics to electrolyze water to produce hydrogen. The wind and photovoltaic loads with lower fluctuations are distributed to the alkaline electrolyzer 42 for consumption and application, and the wind and photovoltaic loads with higher fluctuations are distributed to the proton exchange membrane electrolyzer 43 for consumption and application, and oxygen and hydrogen are produced after purification and separation. The oxygen compressor 44 compresses the 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 charging and discharging, and the oxygen flow rate is adjusted to meet the needs of the oxygen-enriched combustion unit 90. The hydrogen compressor 45 compresses the 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 charging and discharging, and the hydrogen flow rate is adjusted and distributed to meet the needs of the ammonia synthesis unit 60 and the methanol synthesis unit 80.

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

[0034] Optionally, the DC energy consumption of hydrogen production in the alkaline electrolyzer 42 is 4.0 kWh / Nm 3 、4.1kWh / Nm 3 、4.2kWh / Nm 3 or 4.3kWh / Nm 3 Alternatively, the DC energy consumption for hydrogen production of the alkaline electrolyzer 42 may also be within the range between any two of the above DC energy consumptions.

[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 may be within the range between 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 also be within a range between any two of the above cell voltages.

[0037] Optionally, the DC energy consumption of hydrogen production of the proton exchange membrane electrolyzer 43 is 3.8 kWh / Nm 3 、3.85kWh / Nm 3 、3.9kWh / Nm 3 、3.95kWh / Nm 3 、4.0kWh / Nm 3 Alternatively, the DC energy consumption for hydrogen production of the proton exchange membrane electrolyzer 43 may also be within the range between 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 may also be within the range between 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 also be within a range between any two of the above cell voltages.

[0040] Referring again to FIG. 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 uses air as a raw material to produce nitrogen and oxygen. The nitrogen compressor 52 is used to pressurize the nitrogen to the pressure required by the reaction section. The nitrogen storage tank 53 is used to adjust the nitrogen supply of 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 a raw material, converts the air into liquid through a compression cycle deep freezing method, and then gradually separates and produces nitrogen and oxygen 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 to charge and discharge nitrogen, and adjust the nitrogen flow to meet the needs of the ammonia synthesis unit 60. The oxygen is compressed to a certain pressure by the oxygen compressor 44 and sent to the oxygen storage tank 46.

[0042] Referring again to FIG. 2 , in some embodiments, 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 ammonia synthesis reaction device 61 is connected to the hydrogen storage tank 47 and the nitrogen storage tank 53, and the ammonia synthesis reaction device 61 synthesizes ammonia using hydrogen and nitrogen. The ammonia compressor 62 is used to liquefy ammonia. The ammonia storage tank 63 is used to adjust the ammonia supply of the ammonia-blending 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 which are 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 compressed step by step by the compressor. Ammonia synthesis and condensation separation are completed through two-stage ammonia cooling and secondary ammonia separation. Finally, the synthesized ammonia is compressed and frozen by the ammonia compressor 62 and sent to the ammonia storage tank 63 for storage. 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 blending combustion unit 100.

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

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

[0046] Optionally, the operating pressure of the ammonia synthesis reaction unit 61 is 15 MPa, 20 MPa, 25 MPa or 30 MPa, or, the operating pressure of the ammonia synthesis reaction unit 61 may also be within the range between any two of the above-mentioned operating pressures.

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

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

[0049] Referring again to FIG. 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 discharged from the boiler 21 passes through the absorption tower 71 and the regeneration tower 73 to capture carbon dioxide. The carbon dioxide storage tank 74 is used to adjust the carbon dioxide supply of the methanol synthesis unit 80. The absorption tower 71 and the regeneration tower 73 are connected by a lean-rich liquid circulation system, and the lean-rich liquid circulation system contains a carbon dioxide absorbent. The flue gas carbon capture unit 70 also includes a water washing device 72, which is 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 pipeline of the flue gas discharged from the boiler 21 is connected to the absorption tower 71. The top of the absorption tower 71 is integrated with a water washing device 72. The absorption tower 71 and the regeneration tower 73 are connected through a lean and rich liquid circulation system. After pretreatment, the flue gas enters the absorption tower 71 to form 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. Absorbing CO 2 The absorbent is rich liquid, which is heated by the lean-rich liquid heat exchanger and then enters the regeneration tower 73 to desorb CO 2 , the desorbed CO 2 After cooling together with water vapor, carbon dioxide is obtained after removing water, and CO is desorbed. 2 The absorbent is the lean liquid, which flows out from the bottom of the regeneration tower 73, and after heat exchange in the lean-rich liquid heat exchanger, enters the absorption tower 71 to circulate and absorb CO 2 The regeneration tower 73 is connected to a carbon dioxide storage tank 74 , and the carbon dioxide storage tank 74 is used to charge and discharge carbon dioxide and adjust the carbon dioxide flow to meet the needs of the methanol synthesis unit 80 .

[0051] Referring again to FIG. 2 , in some embodiments, 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 the hydrogen storage tank 47 and the carbon dioxide storage tank 74, and the methanol synthesis reaction device 81 synthesizes methanol using hydrogen and carbon dioxide. 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 which are connected in sequence. The methanol synthesis reaction device 81 is connected to the hydrogen storage tank 47 and the carbon dioxide storage tank 74. Hydrogen and carbon dioxide are introduced into the methanol synthesis reaction device 81 to synthesize gaseous methanol. The gaseous methanol is introduced into a cooler for cooling 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 subsequently consumed as a chemical raw material or fuel.

[0053] In some of the embodiments, the operating temperature of the methanol synthesis reaction unit 81 is 220°C~250°C, the operating pressure is 6MPa~8MPa, the volume ratio of hydrogen and carbon dioxide is (3~5):1, and the methanol selectivity is 90%~98%.

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

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

[0056] Optionally, the volume ratio of hydrogen and carbon dioxide in the methanol synthesis reaction unit 81 is 3:1, 3.5:1, 4:1, 4.5:1 or 5:1, or, the volume ratio of hydrogen and carbon dioxide in the methanol synthesis reaction unit 81 may also be within the range between any two of the above volume ratios of hydrogen and carbon dioxide.

[0057] Optionally, the methanol selectivity of the methanol synthesis reaction unit 81 is 90%, 92%, 94%, 96% or 98%, or, the methanol selectivity of the methanol synthesis reaction unit 81 may also be within the range between any two of the above methanol selectivities.

[0058] Referring again to FIG. 2 , 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 the boiler 21 to improve the combustion stability and flexibility of the boiler 21. The oxygen-enriched combustion unit 90 includes an oxygen-enriched burner 91, which is connected to the oxygen storage tank 46. The oxygen is depressurized by the pressure reducing valve and then sent to the oxygen-enriched burner 91 at a certain pressure. A primary oxygen inlet and a secondary oxygen inlet are provided. The primary oxygen inlet adopts a Rafael nozzle structure, and the negative pressure generated by the throat effect is used to suck the smoke back and mix with oxygen, thereby enhancing the ignition performance of the fuel and improving the combustion stability. The secondary oxygen inlet is deflected 15° to 30° toward the axis, so that the secondary oxygen can reach the center of the flame and fully mix with the fuel, thereby improving the burnout rate of the fuel, and performing oxygen-enriched combustion of different proportions in the boiler 21.

[0060] Referring again to FIG. 2 , in some embodiments, the ammonia-blending combustion unit 100 includes an ammonia-blending burner 101 , and the liquid ammonia in the ammonia storage tank 63 is sent into the ammonia-blending burner 101 in a gaseous form after passing through an evaporation device.

[0061] Specifically, ammonia combustion refers to the use of ammonia gas to partially replace coal in the boiler 21 to reduce CO 2 The ammonia combustion unit 100 includes an ammonia burner 101. The liquid ammonia in the ammonia storage tank 63 is sent into the ammonia burner 101 in gaseous form after passing through the evaporation device. The first gas inlet and the second gas inlet are provided. The first gas inlet is a premixed lean gas of ammonia and air, and the equivalence ratio is 0.6-1. The second gas inlet is a premixed rich gas of ammonia and air, and the equivalence ratio is 1-1.3. By adjusting the premixed gas equivalence ratio of the first and second gas inlets, the combustion state and NO x The emission concentration is precisely controlled, and ammonia combustion of different proportions is carried out in the boiler 21 .

[0062] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims, and the description and drawings may be used to interpret the contents of the claims.

Claims

1. A comprehensive energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis, characterized in that: include: Wind and solar power generation units, thermal power generation units, energy storage units, hybrid hydrogen production units, air separation units, ammonia synthesis units, flue gas carbon capture units, methanol synthesis units, oxygen-enriched combustion units and ammonia-blended combustion units; The wind-solar power generation unit and the thermal power generation unit are both connected to the energy storage unit, and the wind-solar power generation unit, the thermal power generation unit and the energy storage unit jointly supply power to the external power grid and the internal system; the hybrid hydrogen production unit is connected to the wind-solar power generation unit, and the hybrid hydrogen production unit utilizes wind and solar power to electrolyze water to produce hydrogen and oxygen; the air separation unit utilizes air to produce nitrogen and oxygen; the air separation unit and the hybrid hydrogen production unit are both connected to the ammonia synthesis unit, and the ammonia synthesis unit utilizes nitrogen and hydrogen as raw materials to synthesize 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; the flue gas carbon capture unit and the mixed hydrogen production unit are both connected to the methanol synthesis unit, and the methanol synthesis unit synthesizes methanol using carbon dioxide and hydrogen as raw materials; the oxygen-enriched combustion unit and the ammonia-blended combustion unit are both connected to the thermal power generation unit, and the oxygen-enriched combustion unit is used to realize oxygen-enriched combustion of the thermal power generation unit, and the ammonia-blended combustion unit is used to realize ammonia-blended combustion of the thermal power generation unit.

2. The integrated energy system for producing hydrogen by coupling wind, solar, thermal and storage with water electrolysis according to claim 1 is characterized in that: The wind-solar power generation unit includes a photovoltaic array and a wind generator; 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 supply control device; the photovoltaic array is connected to the power supply control device, and the photovoltaic array is used to provide electrical energy for the hybrid hydrogen production unit; the wind generator is connected to the power supply control device after passing through a rectifier, and the wind generator is used to provide electrical energy for the hybrid hydrogen production unit; The photovoltaic array, the wind turbine generator and the boiler are all connected to the energy storage device.

3. The integrated energy system for producing hydrogen by coupling wind, solar, thermal and storage with water electrolysis according to claim 2 is characterized in that: The hybrid hydrogen production unit also 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, and the alkaline electrolyzer and the proton exchange membrane electrolyzer are used to carry wind and photovoltaic loads with different fluctuation characteristics to produce hydrogen; the power control device is used to distribute the wind and photovoltaic loads to the alkaline electrolyzer and the proton exchange membrane electrolyzer; the oxygen compressor and the hydrogen compressor are both connected to the alkaline electrolyzer and the proton exchange membrane electrolyzer at the same time; the oxygen compressor is used to boost the oxygen to the storage pressure, and the hydrogen compressor is used to boost the hydrogen to the pressure required by the reaction section; the oxygen storage tank is connected to the oxygen compressor, and the oxygen storage tank is used to adjust the oxygen supply of the oxygen-enriched combustion unit; the hydrogen storage tank is connected to the hydrogen compressor, and the hydrogen storage tank is used to distribute and adjust the hydrogen supply of the ammonia synthesis unit and the methanol synthesis unit.

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

5. The integrated energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis according to claim 3 is characterized in that: The air separation unit comprises 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 uses air as a raw material to produce nitrogen and oxygen; The nitrogen compressor is used to increase the pressure of nitrogen to the pressure required by the reaction section; the nitrogen storage tank is used to adjust the nitrogen supply of the ammonia synthesis unit.

6. The integrated energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis according to claim 5 is characterized in that: The ammonia synthesis unit includes an ammonia synthesis reaction device, an ammonia compressor and an ammonia storage tank which are 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 synthesizes ammonia by using hydrogen and nitrogen; the ammonia compressor is used to liquefy ammonia; and the ammonia storage tank is used to adjust the ammonia supply of the ammonia blending combustion unit.

7. The integrated energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis according to claim 6 is characterized in that: The operating temperature of the ammonia synthesis reaction device is 400°C~500°C, the operating pressure is 15MPa~30MPa, the volume ratio of hydrogen to nitrogen is (3~3.2):1, and the ammonia selectivity is 95%~98%.

8. The integrated energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis according to 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 which are connected in sequence; the absorption tower is connected to the boiler; the flue gas discharged from the boiler passes through the absorption tower and the regeneration tower to capture carbon dioxide; the carbon dioxide storage tank is used to adjust the carbon dioxide supply of the methanol synthesis unit; the absorption tower and the regeneration tower are connected through a lean and rich liquid circulation system, and the lean and rich liquid circulation system contains a carbon dioxide absorbent; the flue gas carbon capture unit also includes a water washing device, and the water washing device is connected to the absorption tower.

9. The integrated energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis according to claim 8 is characterized in that: The methanol synthesis unit comprises a methanol synthesis reaction device and a methanol storage tank which are 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 synthesizes methanol using hydrogen and carbon dioxide. The methanol storage tank is used to store methanol.

10. The integrated energy system for producing hydrogen by coupling wind, solar, thermal and energy storage with water electrolysis according to claim 9 is characterized in that: The operating temperature of the methanol synthesis reaction device is 220°C~250°C, the operating pressure is 6MPa~8MPa, the volume ratio of hydrogen to carbon dioxide is (3~5):1, and the methanol selectivity is 90%~98%.

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