A renewable energy hydrogen production method coupled with liquid hydrogen

Abstract

The application discloses a renewable energy hydrogen production method coupled with liquid hydrogen, which mainly comprises a renewable energy power generation system, a water electrolysis hydrogen production system, a hydrogen liquefaction system, a liquid hydrogen storage tank system and a liquid hydrogen power generation system. The application realizes continuous and stable supply of green hydrogen by adopting liquid hydrogen storage hydrogen, and realizes maximum utilization of renewable energy by generating power through the liquid hydrogen gasification process, reduces the fluctuation of the water electrolysis hydrogen production device, and reduces the production cost of green hydrogen. The application solves the contradiction between the intermittency and fluctuation of renewable energy and the continuity and stability of downstream green hydrogen users in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of renewable energy hydrogen production and storage, and specifically relates to a renewable energy hydrogen production method coupled with liquid hydrogen. Background Technology

[0003] Accelerating the application of green hydrogen in the industrial sector is an important path to promote energy conservation and carbon reduction, and advance new industrialization. However, renewable energy sources, such as solar energy, are affected by natural factors and are characterized by intermittency, volatility, and seasonality, making it impossible to meet the stable hydrogen demand of the industrial sector. Therefore, how to utilize renewable energy sources with significant fluctuations to provide continuous and stable green hydrogen for industrial production has become a hot topic in the current hydrogen energy research field.

[0004] To ensure a continuous and stable supply of green hydrogen, hydrogen storage is typically considered. This involves producing more hydrogen when renewable energy power generation systems have sufficient reserves, and storing some of it to provide hydrogen when renewable energy power generation systems are insufficient. Currently, the main methods for hydrogen storage and transportation include high-pressure gaseous storage, cryogenic liquid storage, and solid-state hydrogen storage. While high-pressure gaseous hydrogen storage technology is relatively mature, it suffers from poor safety and low hydrogen storage density per unit volume. Solid-state hydrogen storage offers better safety and higher hydrogen storage density, but the technology is not yet mature and requires high hydrogen release temperatures. Cryogenic liquid hydrogen storage, on the other hand, has the advantages of high storage density and efficiency, making it more suitable as a hydrogen storage method.

[0005] Chinese patent CN114232005 proposes an energy storage device and method that couples hydrogen production by water electrolysis with cryogenic conditions. It solves the contradiction between the discontinuous photovoltaic resources and the continuous hydrogen production requirements by constructing a liquid nitrogen pre-cooling hydrogen liquefaction system, a liquid hydrogen-liquid nitrogen heat exchange system, a cold energy storage system, and an air separation device cold energy utilization system. However, the device requires the construction of an air separation device system, which is highly complex and requires a large investment. Summary of the Invention

[0006] This invention proposes a renewable energy-based hydrogen production method coupled with liquid hydrogen. It achieves a continuous and stable supply of green hydrogen through liquid hydrogen storage, while simultaneously maximizing the utilization of renewable energy by generating electricity through the liquid hydrogen gasification process. This reduces the volatility of water electrolysis hydrogen production units and lowers the production cost of green hydrogen. This addresses the contradiction between the intermittency and volatility of renewable energy and the continuity and stability of downstream green hydrogen users in existing technologies.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A renewable energy hydrogen production method coupled with liquid hydrogen, characterized in that the method comprises the following steps:

[0009] The electricity generated by the renewable energy power generation system is sent to the water electrolysis hydrogen production system;

[0010] The water electrolysis hydrogen production system utilizes the electricity generated by the renewable energy power generation system and the liquid hydrogen power generation system to produce room temperature gaseous hydrogen through water electrolysis;

[0011] The room-temperature gaseous hydrogen is cooled and liquefied to produce liquid hydrogen through a hydrogen liquefaction system refrigeration cycle.

[0012] The produced liquid hydrogen is sent to a liquid hydrogen storage tank system;

[0013] The liquid hydrogen power generation system utilizes the cooling energy from the liquid hydrogen vaporization process to generate electricity, which is then sent to the water electrolysis hydrogen production system.

[0014] The present invention discloses a renewable energy hydrogen production method coupled with liquid hydrogen, which is further characterized in that the method mainly consists of a renewable energy power generation system, an electrolysis water hydrogen production system, a hydrogen liquefaction system, a liquid hydrogen storage tank system, and a liquid hydrogen power generation system.

[0015] This invention discloses a renewable energy-based hydrogen production method coupled with liquid hydrogen, further characterized in that: the renewable energy power generation system includes one or more combined power generation systems such as solar power generation, wind power generation, tidal power generation, and geothermal power generation. Preferably, the renewable energy power generation system consists of solar power generation facilities and wind power generation facilities, wherein the solar power generation facilities include photovoltaic modules, inverters, and photovoltaic transformers; and the wind power generation facilities include wind turbines and wind transformers.

[0016] This invention discloses a renewable energy hydrogen production method coupled with liquid hydrogen, further characterized in that: the water electrolysis hydrogen production system includes one or more combinations of alkaline water electrolysis hydrogen production systems, proton exchange membrane hydrogen production systems, anion exchange membrane hydrogen production systems, and high-temperature solid oxide hydrogen production systems. Preferably, the water electrolysis hydrogen production system is an alkaline water electrolysis hydrogen production system, which consists of an electrolysis section, a gas-liquid separation section, and a hydrogen purification section. The electrolysis section mainly includes an electrolyzer, a transformer, and a rectifier; the gas-liquid separation section mainly includes a gas-liquid separator, a washing cooler, an alkaline cooler, and an alkaline circulating pump; and the hydrogen purification section mainly includes a deoxygenator, a dryer, and a cooler.

[0017] This invention discloses a renewable energy hydrogen production method coupled with liquid hydrogen, further characterized in that: the hydrogen liquefaction system includes a hydrogen precooling section and a hydrogen liquefaction section. The hydrogen precooling section can employ liquid nitrogen precooling or a mixed refrigerant precooling; the hydrogen liquefaction section can employ one of the Linde-Hampson hydrogen liquefaction process, the Claude hydrogen cycle liquefaction process, the Brayton helium cycle liquefaction process, or a mixed refrigerant liquefaction process. Preferably, the hydrogen liquefaction system comprises a mixed refrigerant precooling section and a mixed refrigerant liquefaction section, wherein the mixed refrigerant precooling section uses a mixture of methane, propane, pentane, ethylene, hydrogen, and nitrogen as the refrigerant, and the mixed refrigerant liquefaction section uses a mixture of hydrogen and helium as the refrigerant.

[0018] The present invention discloses a renewable energy hydrogen production method coupled with liquid hydrogen, which is further characterized in that: the liquid hydrogen storage tank system mainly consists of a liquid hydrogen storage tank and a liquid hydrogen booster pump.

[0019] This invention discloses a renewable energy hydrogen production method coupled with liquid hydrogen, further characterized in that: the liquid hydrogen power generation system can employ one of the following methods: direct expansion, Rankine cycle, Brayton cycle, and combined cycle. Preferably, the liquid hydrogen power generation system employs the Rankine cycle and consists of a circulating pump and a turbine generator set.

[0020] The present invention discloses a renewable energy hydrogen production method coupled with liquid hydrogen, which is further characterized in that: the electricity generated by the renewable energy power generation system and the liquid hydrogen power generation system is sent to the water electrolysis hydrogen production system.

[0021] This invention discloses a renewable energy hydrogen production method coupled with liquid hydrogen, further characterized in that: the hydrogen produced by the water electrolysis hydrogen production system is sent to downstream users, and the surplus hydrogen is sent to a hydrogen liquefaction system for liquefaction and stored as liquid hydrogen in a liquid hydrogen storage tank system. The reheated hydrogen produced by the liquid hydrogen power generation system is sent together with the hydrogen produced by the water electrolysis hydrogen production system to downstream users.

[0022] As one application, the above-mentioned renewable energy hydrogen production method coupled with liquid hydrogen includes the following steps:

[0023] (1) The electricity generated by the renewable energy power generation system consisting of solar power generation facilities and wind power generation facilities is sent to the water electrolysis hydrogen production system;

[0024] (2) The hydrogen produced by the water electrolysis system is delivered to downstream hydrogen users. The excess hydrogen is sent to the hydrogen liquefaction system to produce liquid hydrogen, which is then stored in the liquid hydrogen storage tank system.

[0025] (3) When changes in environmental factors such as sunlight and wind power lead to insufficient electricity generation from the renewable energy power generation system, making it impossible for the hydrogen produced by the water electrolysis hydrogen production system to meet the needs of downstream hydrogen users, the liquid hydrogen stored in the liquid hydrogen storage tank is pressurized by the liquid hydrogen booster pump and sent to the liquid hydrogen power generation system. In the liquid hydrogen power generation system, the liquid hydrogen exchanges heat with the Rankine cycle working fluid, and the liquid hydrogen vaporizes to release cold energy and condense the working fluid, thereby obtaining room temperature gaseous hydrogen which is sent to downstream hydrogen users. The condensed working fluid is pressurized by the circulation pump and enters the turbine generator set to drive the turbine to generate electricity. The generated electricity is sent to the water electrolysis hydrogen production system to further increase the hydrogen production of the water electrolysis hydrogen production system.

[0026] The present invention has the following beneficial effects:

[0027] 1. This invention couples renewable energy electrolysis for hydrogen production, hydrogen liquefaction, and cryogenic liquid hydrogen power generation technologies. Through hydrogen liquefaction and liquid hydrogen power generation, it achieves a continuous and stable supply of hydrogen to downstream users while improving the utilization efficiency of renewable energy.

[0028] 2. When renewable energy is abundant, the surplus hydrogen produced by water electrolysis is liquefied and stored in liquid hydrogen storage tanks. When renewable energy is insufficient, the stored liquid hydrogen is vaporized and reheated through a liquid hydrogen cryogenic power generation system to provide hydrogen to downstream users while generating electricity to power the water electrolysis hydrogen production unit. By storing liquid hydrogen, the maximum utilization of renewable energy is achieved, which has good application prospects.

[0029] 3. By using liquid hydrogen as a buffer, it can not only provide hydrogen to downstream applications when renewable energy is insufficient, but also generate electricity through the liquid hydrogen cryogenic power generation system to maintain the operation of the water electrolysis hydrogen production system under a certain load. When renewable energy is sufficient, it can quickly increase the workload and improve the utilization rate of renewable energy. Attached Figure Description

[0030] Appendix Figure 1 This invention provides a schematic diagram of a renewable energy hydrogen production process coupled with liquid hydrogen.

[0031] The attached figures are labeled as follows: 1-Photovoltaic power generation system; 2-Alkaline water electrolysis hydrogen production system; 3-Hydrogen liquefaction system; 4-Liquid hydrogen storage tank system; 5-Liquid hydrogen power generation system; 6-Electricity generated by the photovoltaic power generation system; 7-Hydrogen produced by the water electrolysis hydrogen production system; 8-Surplus hydrogen; 9-Liquid hydrogen; 10-Liquid hydrogen after pressurization; 11-Electricity generated by the liquid hydrogen power generation system; 12-Hydrogen after reheating. Detailed Implementation

[0032] The implementation of the technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0033] To better understand the technical solution of the present invention, the content of the present invention will be further described below with reference to embodiments.

[0034] like Figure 1 As shown, this embodiment uses a photovoltaic power generation system 1 to generate electricity from solar energy. The electricity 6 generated by the photovoltaic power generation system is sent to an alkaline water electrolysis hydrogen production system 2 to produce hydrogen through water electrolysis. The hydrogen 7 produced by the alkaline water electrolysis hydrogen production system 2 is sent to downstream users. When solar energy resources are abundant, such as at noon in summer, the hydrogen produced by the alkaline water electrolysis hydrogen production system 2 has a surplus after meeting the needs of downstream users. The surplus hydrogen 8 is sent to a hydrogen liquefaction system 3. The precooling section of the hydrogen liquefaction system 3 uses a mixed refrigerant precooling process to precool the hydrogen to -193°C. The mixed precooling agent is a mixture of methane, propane, pentane, ethylene, hydrogen, and nitrogen. The liquefaction section uses a mixture of hydrogen and helium as a refrigerant to cool the hydrogen to -254°C to obtain cryogenic liquid hydrogen 9, which is then sent to a liquid hydrogen storage tank system 4. When solar energy resources are insufficient, in order to meet the downstream hydrogen demand, the liquid hydrogen in the liquid hydrogen storage tank is pressurized by a booster pump and then sent to a liquid hydrogen power generation system 5. Within the liquid hydrogen power generation system 5, liquid hydrogen releases cooling energy through heat exchange with the circulating working fluid, thereby obtaining reheated hydrogen 12 which is then delivered to downstream hydrogen users. Simultaneously, the cooling energy released during the liquid hydrogen vaporization and reheating process condenses the circulating working fluid within the liquid hydrogen power generation system 25. After condensation, the circulating working fluid is pressurized and enters the turbine generator set to drive the turbine to generate electricity. The electricity 11 generated by the liquid hydrogen power generation system is delivered to the alkaline water electrolysis hydrogen production system 2, further increasing the hydrogen 7 produced by the water electrolysis hydrogen production system and meeting the downstream demand for hydrogen.

[0035] The above are merely typical embodiments of the present invention. It should be noted that those skilled in the art can make several improvements or substitutions without departing from the principles described in the present invention, and these improvements or substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A renewable energy hydrogen production method coupled with liquid hydrogen, characterized in that... The method consists of the following steps: The electricity generated by the renewable energy power generation system is sent to the water electrolysis hydrogen production system; The water electrolysis hydrogen production system utilizes the electricity generated by the renewable energy power generation system and the liquid hydrogen power generation system to produce room temperature gaseous hydrogen through water electrolysis; The room-temperature gaseous hydrogen is cooled and liquefied to produce liquid hydrogen through a hydrogen liquefaction system refrigeration cycle. The produced liquid hydrogen is sent to a liquid hydrogen storage tank system; The liquid hydrogen power generation system utilizes the cooling energy from the liquid hydrogen vaporization process to generate electricity, which is then sent to the water electrolysis hydrogen production system.

2. The renewable energy hydrogen production method according to claim 1, characterized in that: The method mainly consists of a renewable energy power generation system, an electrolysis water hydrogen production system, a hydrogen liquefaction system, a liquid hydrogen storage tank system, and a liquid hydrogen power generation system.

3. The renewable energy hydrogen production method according to claim 1, characterized in that: The renewable energy power generation system includes one or more of the following: solar power generation system, wind power generation system, tidal power generation system, and geothermal power generation system.

4. The renewable energy hydrogen production method according to claim 1, characterized in that: The renewable energy power generation system consists of solar power generation facilities and wind power generation facilities, wherein the solar power generation facilities include photovoltaic modules, inverters and photovoltaic power generation transformers; and the wind power generation facilities include wind turbines and wind power generation transformers.

5. The renewable energy hydrogen production method according to claim 1, characterized in that: The aforementioned water electrolysis hydrogen production system includes one or more combinations of alkaline water electrolysis hydrogen production system, proton exchange membrane hydrogen production system, anion exchange membrane hydrogen production system, and high-temperature solid oxide hydrogen production system.

6. The renewable energy hydrogen production method according to claim 1, characterized in that: The water electrolysis hydrogen production system is an alkaline water electrolysis hydrogen production system. The system consists of an electrolysis section, a gas-liquid separation section, and a hydrogen purification section. The electrolysis section mainly includes an electrolytic cell, a transformer, and a rectifier. The gas-liquid separation section mainly includes a gas-liquid separator, a washing cooler, an alkaline cooler, and an alkaline circulating pump. The hydrogen purification section mainly includes a deoxygenator, a dryer, and a cooler.

7. The renewable energy hydrogen production method according to claim 1, characterized in that: The hydrogen liquefaction system includes a hydrogen precooling section and a hydrogen liquefaction section.

8. The renewable energy hydrogen production method according to claim 7, characterized in that: The hydrogen precooling section can use liquid nitrogen precooling or mixed refrigerant precooling; the hydrogen liquefaction section can use one of the following processes: Linde-Hampson hydrogen liquefaction process, Claude hydrogen cycle liquefaction process, Brayton helium cycle liquefaction process, or mixed refrigerant liquefaction process.

9. The renewable energy hydrogen production method according to claim 1, characterized in that: The liquid hydrogen storage tank system mainly consists of a liquid hydrogen storage tank and a liquid hydrogen booster pump.

10. The renewable energy hydrogen production method according to claim 1, characterized in that: The liquid hydrogen power generation system can employ one of the following methods: direct expansion, Rankine cycle, Brayton cycle, or combined cycle.

11. The renewable energy hydrogen production method according to claim 1, characterized in that: The electricity generated by the renewable energy power generation system and the liquid hydrogen power generation system is sent to the water electrolysis hydrogen production system.

12. The renewable energy hydrogen production method according to claim 1, characterized in that: The hydrogen produced by the water electrolysis hydrogen production system is sent to downstream users, and the surplus hydrogen is sent to the hydrogen liquefaction system for liquefaction and then stored as liquid hydrogen in the liquid hydrogen storage tank system.

13. A renewable energy hydrogen production method coupled with liquid hydrogen includes the following steps: 1) The electricity generated by the renewable energy power generation system, which consists of solar power generation facilities and wind power generation facilities, is sent to the water electrolysis hydrogen production system; 2) The hydrogen produced by the water electrolysis system is delivered to downstream hydrogen users. The excess hydrogen is sent to the hydrogen liquefaction system to produce liquid hydrogen, which is then stored in the liquid hydrogen storage tank system. 3) When changes in environmental factors such as sunlight and wind power lead to insufficient electricity generation from the renewable energy power generation system, making it impossible for the hydrogen produced by the water electrolysis hydrogen production system to meet the needs of downstream hydrogen users, the liquid hydrogen stored in the liquid hydrogen storage tank is pressurized by a liquid hydrogen booster pump and sent to the liquid hydrogen power generation system. In the liquid hydrogen power generation system, the liquid hydrogen exchanges heat with the Rankine cycle working fluid, and the liquid hydrogen vaporizes, releasing cold energy to condense the cycle working fluid, thereby obtaining room temperature gaseous hydrogen which is sent to downstream hydrogen users. The condensed cycle working fluid is pressurized by a circulation pump and enters the turbine generator set to drive the turbine to generate electricity, which is then sent to the water electrolysis hydrogen production system to further increase the hydrogen production of the water electrolysis hydrogen production system.

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