Electrolysis of high-salinity water to produce hydrogen, power plant energy storage system and method

Abstract

The application provides an electrolysis high-salinity water hydrogen production system, a power plant energy storage system and a method, relates to the technical field of water electrolysis hydrogen production and energy storage, and comprises a salt water chamber and a fresh water chamber, the salt water chamber and the fresh water chamber are connected through a hydrophobic gas permeable membrane, high-heat salt water is arranged in the salt water chamber, and water vapor enters the fresh water chamber through the hydrophobic gas permeable membrane; an anode chamber and a cathode chamber, the anode chamber and the fresh water chamber are connected through a water-permeable gas-resistant membrane, the anode chamber and the cathode chamber are connected through a proton exchange membrane, and an anode in the anode chamber and a cathode in the cathode chamber are respectively connected with an external power supply. The technical scheme of the application does not need to carry out desalination treatment on the salt water, and can directly electrolyze high-salinity water to produce hydrogen; on the one hand, the application can be used for high-salinity water hydrogen production and energy storage of western or offshore wind power and photovoltaic power plants, and can recover rich lithium elements and rare earth elements in salt lakes and seawater. On the other hand, the application can also be used for directly producing hydrogen by using desulfurization wastewater of a coal-fired power plant, can realize desulfurization wastewater concentration reduction without external heat source, and can realize desulfurization wastewater resource utilization.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production and energy storage technology through water electrolysis, and in particular to a hydrogen production system, power plant energy storage system, and method based on the electrolysis of high-salt water. Background Technology

[0002] Under the overarching policy of "dual carbon" (carbon diversification and energy conservation), my country needs to install a large number of wind and solar power units. However, wind and solar resources are inherently highly volatile, necessitating energy storage technologies for regulation. Among these, electricity-to-fuel conversion, particularly water electrolysis for hydrogen production and storage, is a key area of ​​focus for research institutions, enterprises, and industries. Western my country possesses abundant wind and solar resources, especially in its desert and Gobi regions, suitable for photovoltaic and wind power development. Eastern China has a vast continental shelf, ideal for constructing numerous offshore wind turbines. These power plants can utilize surplus wind and solar power resources through water electrolysis for hydrogen production. However, the western region suffers from arid climates and high evaporation rates, resulting in high salinity in lakes and rivers. Desalination processes are required to remove salt from the water before hydrogen production can be achieved, increasing investment and operating costs. Seawater also requires desalination before hydrogen production. However, the large size and complexity of seawater desalination systems limit the application prospects of seawater electrolysis for hydrogen production.

[0003] The water-scarce western regions contain numerous salt lakes. These lakes have low lithium concentrations, which can be increased through concentration. Extracting lithium from high-concentration brine is relatively inexpensive, allowing for the direct production of industrial-grade lithium carbonate, which can then be purified into further processed lithium products. Similarly, seawater contains valuable lithium and rare earth elements.

[0004] Limestone-gypsum wet flue gas desulfurization (FGD) is the most widely used and technologically mature desulfurization process in the world. Wet FGD processes generate wastewater, known as desulfurization wastewater. This wastewater has a high salt content and cannot be discharged, making it the most difficult wastewater to treat from coal-fired power plants. The resource utilization of desulfurization wastewater has been a hot research topic. On the other hand, coal-fired power plants have the advantage of low electricity prices. The electricity generated by peak shaving and valley filling in the power grid can also be used to electrolyze water to produce hydrogen.

[0005] In summary, hydrogen production through water electrolysis has very high requirements for water quality. Freshwater resources are scarce in the arid and Gobi regions of the west and the deep-sea areas of the east, necessitating desalination of brine and seawater. This involves long process flows, significant investment and operating costs, and extended project construction periods. Similarly, coal-fired power plants generate large amounts of desulfurization wastewater, and the highly saline brine is difficult to utilize as a resource. Current treatment methods aim for compliant discharge or zero wastewater discharge, but this involves huge investments, high operating costs, low economic benefits, and insufficient water resource utilization. Summary of the Invention

[0006] The purpose of this invention is to provide a hydrogen production system, power plant energy storage system, and method based on the electrolysis of high-salinity water. On the one hand, it enables hydrogen production through electrolysis without the need for a desalination section. On the other hand, it allows for the concentration and extraction of lithium and rare earth elements from salt lakes without the need for an external heat source.

[0007] This invention provides an electrolytic high-salt water hydrogen production system, comprising: a brine chamber and a freshwater chamber, wherein the brine chamber and the freshwater chamber are connected by a hydrophobic and permeable membrane, the brine chamber contains high-heat brine, and water vapor enters the freshwater chamber through the hydrophobic and permeable membrane; an anode chamber and a cathode chamber, wherein the anode chamber and the freshwater chamber are connected by a water-permeable and gas-barrier membrane, and the anode chamber and the cathode chamber are connected by a proton exchange membrane, wherein the anode in the anode chamber and the cathode in the cathode chamber are respectively connected to an external power source.

[0008] Furthermore, the brine chamber is connected to the purification system or the tail heating device via a brine outlet pipe.

[0009] Furthermore, it also includes a conductivity meter connected to the freshwater chamber, and the freshwater chamber is provided with a freshwater discharge port.

[0010] Furthermore, the freshwater outlet is connected to a circulating water pipe, which is equipped with a freshwater pump and the conductivity meter, and a heat exchange system for heat exchange is located outside the circulating water pipe.

[0011] Furthermore, an oxygen collection device is connected to the outside of the anode, and a hydrogen collection device is connected to the outside of the cathode.

[0012] The present invention also provides a power plant energy storage system, wherein a brine inlet pipe is connected to the brine chamber, and high-salinity water in the power plant area enters the brine chamber through the brine inlet pipe.

[0013] Furthermore, a buffer tank is provided at the upstream end of the brine inlet pipe, and the buffer tank is connected to the purification system or the tail heating device through a pipeline, and a conductivity meter is provided on the connected pipeline.

[0014] Furthermore, the brine inlet pipe is equipped with a preheating device and a brine pump, which are connected to the power plant's power system for power supply.

[0015] Furthermore, the external power source includes the power plant's power system.

[0016] This invention also provides a method for energy storage in a power plant, comprising the following steps: S1, during a power surplus period, the power plant's power system supplies power to activate the preheating device and the brine pump. The high-salinity water in the power plant area is heated by the preheating device and enters the brine chamber through the brine inlet pipe; S2, the power plant's power system supplies power to activate the freshwater pump. The water vapor pressure in the brine chamber is higher than that in the freshwater chamber. The water vapor passes through the hydrophobic and permeable membrane into the freshwater chamber, where it is converted into freshwater through the circulating water pipe. The freshwater outlet periodically drains water to prevent salt accumulation; S3, the power plant's power system supplies power to the anode. Freshwater in the freshwater chamber passes through the hydrophobic and gas-barrier membrane into the anode chamber, where an oxygen evolution reaction occurs: 2H₂O → 4H₂O. + +O2+4e - Oxygen is stored in the oxygen collection device; S4, the power plant's power system supplies power to the cathode, and the anode chamber contains H... + The hydrogen enters the cathode chamber through the proton exchange membrane, where a hydrogen evolution reaction occurs: 4H₂O → 2H₂O + +4e - →2H2, hydrogen is stored in the hydrogen collection device; S5, the high brine in the power plant area and the concentrated brine in the brine chamber are recovered by the purification system or the tail heating device.

[0017] The beneficial effects of the technical solution of this invention are as follows:

[0018] (1) Taking advantage of the low electricity price of power plants to produce large quantities of hydrogen saves energy and maximizes economic value, and has broad application prospects. On the one hand, it can be used in wind power and photovoltaic power plants in western or deep-sea areas where salt lakes are widely distributed, to produce hydrogen and store energy using the high salinity of their power plant areas, while recovering the rich lithium and rare earth elements in salt lakes and seawater. On the other hand, it can also be used in coal-fired power plants to directly produce hydrogen from desulfurization wastewater. It can achieve the separation of wastewater concentration and volume reduction without the need for an external heat source. The concentrated water can be treated in the flue or evaporated and crystallized to recover salt. The distilled water can be directly used to electrolyze and produce hydrogen, realizing the resource utilization of desulfurization wastewater.

[0019] (2) No desalination treatment of brine is required; hydrogen can be produced directly by electrolysis of high-salt water.

[0020] (3) A proton exchange membrane hydrogen production system is used, which is suitable for fluctuating power sources such as wind power and photovoltaic power.

[0021] (4) The structure is simple and compact, and the system integration equipment can be made into skid-mounted or containerized types; it is convenient to transport; the process flow is short, the number of operation points is small, and the operating cost is low. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the internal structure of the electrolytic high-salt water hydrogen production system of the present invention;

[0024] Figure 2 For the present invention Figure 1 The main view;

[0025] Figure 3 This is an external schematic diagram of the electrolytic high-salt water hydrogen production system of the present invention;

[0026] Figure 4 This is a schematic diagram of the power plant energy storage system according to Embodiment 3 of the present invention;

[0027] Figure 5 This is a graph showing the change in the conductivity of freshwater over time in Example 3 of the present invention.

[0028] Figure 6 This is a graph showing the hydrogen production rate over time in Example 3 of the present invention.

[0029] Figure 7 This is a schematic diagram of the power plant energy storage system according to Embodiment 4 of the present invention;

[0030] Figure 8 This is a graph showing the change in the conductivity of freshwater over time in Example 4 of the present invention.

[0031] Figure 9 This is a graph showing the hydrogen production rate over time in Example 4 of the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Equipment casing, 2-Brine chamber, 201-Brine outlet pipe, 202-Brine inlet pipe, 203-Brine pump, 204-Preheating device, 3-Hydrophobic and breathable membrane, 4-Freshwater chamber, 401-Circulating water pipe, 402-Freshwater discharge port, 403-Freshwater pump, 5-Hydrophobic and gas-barrier membrane, 6-Anode chamber, 601-Oxygen outlet, 602-Oxygen collection device, 7-Anode, 8-Proton exchange membrane, 9-Cathode, 10-Cathode chamber, 1001-Hydrogen outlet, 1002-Hydrogen collection device, 11-Purification system, 12-Tail heating device, 13-Heat exchange system, 1301-Heat exchange pump, 14-External power supply, 15-Buffer tank, 16-Conductivity meter, 17-Thermometer, 18-pH meter, 19-High saline water, 20-Desulfurization wastewater, 21-Product. Detailed Implementation

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, 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," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0036] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Example 1

[0038] like Figures 1-4 and Figure 7As shown, this invention provides an electrolytic high-salt water hydrogen production system, comprising: a brine chamber 2 and a freshwater chamber 4, connected by a hydrophobic and breathable membrane 3; the brine chamber 2 contains high-heat brine, and water vapor enters the freshwater chamber 4 through the hydrophobic and breathable membrane 3; an anode chamber 6 and a cathode chamber 10, connected by a hydrophobic and gas-barrier membrane 5 and a proton exchange membrane 8; the anode 7 in the anode chamber 6 and the cathode 9 in the cathode chamber 10 are respectively connected to an external power supply 14. The brine chamber 2 is connected to a purification system 11 or a tail heating device 12 via a brine outlet pipe 201. The purification system 11 is used to purify the concentrated brine in the brine chamber 2, and the tail heating device 12 is used to evaporate and crystallize the brine. It also includes a conductivity meter 16 communicating with the freshwater chamber 4, and the freshwater chamber 4 is provided with a freshwater discharge port 402. The freshwater chamber 4 is connected to a circulating water pipe 401. The circulating water pipe 401 is equipped with a freshwater pump 403 and a conductivity meter 16. A heat exchange system 13 for heat exchange is located outside the circulating water pipe 401. An oxygen collection device 602 is connected to the outside of the anode chamber 6, and a hydrogen collection device 1002 is connected to the outside of the cathode chamber 10.

[0039] More specifically, the electrolytic high-salt water hydrogen production system includes a device shell 1, and four chambers, namely brine chamber 2, fresh water chamber 4, anode chamber 6 and cathode chamber 10, are sequentially opened inside the device shell 1. On the outside of the device shell 1, corresponding to the four chambers, are arranged in sequence as follows: brine inlet pipe 202 and brine outlet pipe 201 (located at opposite ends of brine chamber 2 respectively), circulating water pipe 401 (connecting opposite ends of fresh water chamber 4), oxygen outlet 601 (connecting to anode chamber 6), and hydrogen outlet 1001 (connecting to cathode chamber 10).

[0040] The hydrophobic and breathable membrane 3 is mainly used to allow water vapor in the brine chamber 2 to pass into the freshwater chamber 4 (the brine chamber 2 contains hot brine, and the water vapor pressure is higher than that in the freshwater chamber 4, so it moves into the freshwater chamber 4), but it prevents the brine solution from entering. Therefore, ions in the brine chamber 2 are trapped inside the brine chamber 2 and cannot enter the freshwater chamber 4. Specific materials can be selected from one or more combinations of porous polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), and polyvinylidene fluoride (PVDF) and manufactured by stretching or composite membrane methods. The membrane pore size is 0.2-0.4 μm.

[0041] The water-permeable and gas-barrier membrane 5 is mainly used for freshwater to permeate into the anode chamber 6 in the freshwater chamber 4, but prevents oxygen from entering the freshwater chamber 4 from the anode chamber 6, thus avoiding oxygen diffusion and loss. The specific material can be a hydrophilic ceramic membrane. Utilizing the capillary condensation principle, the membrane only allows liquid to pass through, preventing hydrogen from entering the freshwater chamber 4. The pore size of the ceramic membrane is 25-100 nm.

[0042] Proton exchange membrane 8 is mainly used in the anode chamber 6H +Ions enter the cathode chamber 10, and the specific membrane material can be selected from the Chemours Nafion series membranes.

[0043] The anode 7 is a surface structure that is attached to and covers one side of the anode chamber 6 of the proton exchange membrane 8. The specific material can be a titanium-based flow field plate coated with platinum or gold elements, and combined with an iridium or ruthenium metal catalyst and a gas diffusion layer.

[0044] The cathode 9 is a surface structure that is attached to and covers one side of the cathode chamber 10 of the proton exchange membrane 8. The specific materials can be selected from a combination of a titanium-based flow field plate, a catalyst with platinum or palladium noble metal and its alloy composition, and a gas diffusion layer.

[0045] The purification system 11 is mainly used to purify salts and other useful minerals in concentrated brine to obtain abundant lithium and rare earth elements. The purification device for this function is common knowledge and needs to be designed according to the specific composition of the concentrated brine; its structure need not be elaborated upon. The tail-end heating device 12 is mainly used to treat concentrated brine by evaporation and crystallization, such as for the recovery of impurities from desulfurization wastewater.

[0046] The circulating water pipe 401 is equipped with a thermometer 17, a pH meter 18, and a conductivity meter 16. These instruments monitor the salinity of the freshwater in the freshwater chamber 4. When the salinity exceeds a set value, the freshwater discharge port 402 is opened to discharge brine, reducing the salinity and controlling the temperature of the heat exchange system 13, thereby controlling the freshwater temperature. The water temperature in the freshwater chamber 4 is maintained between 5-25℃, and the pH is 6.5-8. The freshwater discharge port 402 can be directly connected to the circulating water pipe 401. The heat exchange system 13 can employ, for example, a tubular heat exchanger, to exchange heat with the freshwater without affecting its purity, such as promoting the formation of freshwater from water vapor and controlling the freshwater temperature.

[0047] Oxygen produced in anode chamber 6 via the oxygen evolution reaction (OER) enters oxygen collection device 602 (such as an oxygen storage tank) through oxygen outlet 601 and is collected. Hydrogen produced in anode chamber 6 via the hydrogen evolution reaction (HER) enters hydrogen collection device 1002 (such as a hydrogen storage tank) through hydrogen outlet 1001 and is collected. This allows for energy storage.

[0048] Example 2

[0049] like Figures 1-4 and Figure 7As shown, the present invention also provides a power plant energy storage system. A brine inlet pipe 202 is connected to a brine chamber 2, through which high-salinity water from the power plant area enters the brine chamber 2. A buffer tank 15 is provided at the upstream end of the brine inlet pipe 202. The buffer tank 15 is connected to the purification system 11 via a pipeline, and a conductivity meter 16 is provided on the connected pipeline. A preheating device 204 and a brine pump 203 are provided on the brine inlet pipe 202, and the preheating device 204 and the brine pump 203 are connected to the power plant's power system for power supply. The external power source 14 includes the power plant's power system.

[0050] Specifically, when the electrolysis high-salt water hydrogen production system is used in a power plant energy storage system, it can use the power of a power plant with surplus electricity, such as a photovoltaic or wind power plant with high wind speed and sufficient sunlight, or a coal-fired power plant with low load, to power the electrolysis high-salt water hydrogen production system to produce hydrogen and store energy, and release energy to supplement the power when there is a power shortage.

[0051] For example, power is supplied to brine pump 203 to pump salt lake water and seawater from areas near wind and photovoltaic power stations into brine chamber 2, and desulfurization wastewater from coal-fired power plants is also pumped into brine chamber 2; power is supplied to preheating device 204 (such as an electric heater) to heat the brine to high temperature and evaporate it into water vapor; power is supplied to external power source 14, which serves as the anode 7 and cathode 9, to initiate an electrolysis reaction; power is supplied to freshwater pump 403 in circulating water pipe 401 and heat exchange pump 1301 in heat exchange system 13 to complete the freshwater cooling cycle; power is supplied to purification system 11 to evaporate and obtain crystals, etc. The energy storage system of this power plant has low electricity costs and readily available brine.

[0052] Example 3

[0053] like Figures 1-6 As shown, this invention also provides an energy storage method for wind power and photovoltaic power plants. High-salinity water (>3.5%) from a salt lake in western China is taken and fed into a buffer tank (15) at a flow rate of 0.2 t / h. After homogenization and mixing in the buffer tank (15), the water enters a hot brine circulation system. First, it is heated to 50°C by a water pump. The high-salinity hot water enters the brine chamber (2) through the brine inlet pipe (202). The temperature in the brine chamber (2) is higher than the temperature of the freshwater in the freshwater chamber (4), and the water vapor pressure in the brine chamber (2) is higher than that in the freshwater chamber (4). Therefore, the water vapor passes through a hydrophobic and breathable membrane (3) and enters the freshwater chamber (4). Heat exchange between the freshwater system and the external cooling water system at the heat exchanger further promotes this process. The cooling water temperature in the freshwater chamber (4) is ensured to be between 20-25°C. The electrical conductivity of the freshwater in the freshwater chamber (4) is below 10 μm / cm. Freshwater in freshwater chamber 4 passes through the water-permeable gas-barrier membrane 5 and enters anode chamber 6. When external power supply 14 is applied, oxygen evolution reaction (OER) occurs at anode 7: 2H₂O → 4H₂O. + +O2+4e - Oxygen is discharged from oxygen outlet 601 and collected through an oxygen storage tank.+ The hydrogen enters through the proton exchange membrane 8 and enters at the cathode 9, where the hydrogen evolution reaction (HER) occurs: 4H + +4e - →2H2. Hydrogen gas is discharged from hydrogen outlet 1001 and collected in a hydrogen storage tank; the hydrogen purity can reach over 99.99%. A portion of fresh water is periodically discharged from fresh water chamber 4 to maintain a low salinity. Concentrated brine is periodically discharged, with a salinity greater than 20%. The concentrated brine is purified by purification system 11 to recover purification products 21, such as lithium salts and rare earth resources. After 500 hours of continuous operation, from... Figure 5 and Figure 6 It can be seen that the conductivity of freshwater can be stabilized at 10 μm / cm, and the hydrogen production rate can be stabilized at 12 m. 3 The above / h indicates that the system is feasible and has broad application prospects.

[0054] Example 4

[0055] like Figures 1-3 and Figures 7-9 As shown, this invention also provides an energy storage method for a coal-fired power plant. Desulfurization wastewater 20 from a power plant, with a salt content (>3.5%), is introduced into a buffer tank 15 at a flow rate of 0.2 t / h. After homogenization and mixing, it enters a hot brine circulation system. Since the temperature of the desulfurization wastewater 20 when discharged from the system is approximately 50°C, there is no need to raise the water temperature again. The desulfurization wastewater 20 enters the brine chamber 2 through the brine inlet pipe 202. The temperature in the brine chamber 2 is higher than that in the freshwater chamber 4, and the water vapor pressure in the brine chamber 2 is greater than that in the freshwater chamber 4. Therefore, the water vapor passes through the hydrophobic and breathable membrane 3 and enters the freshwater chamber 4. The heat exchange between the freshwater system and the external cooling water system at the heat exchanger further promotes this process. The cooling water temperature in the freshwater chamber 4 is ensured to be between 5 and 25 degrees Celsius. The conductivity of the freshwater in the freshwater chamber 4 is less than 10 μm / cm. Freshwater in freshwater chamber 4 passes through the water-permeable gas-barrier membrane 5 and enters anode chamber 6. When external power supply 14 is applied, oxygen evolution reaction (OER) occurs at anode 7: 2H₂O → 4H₂O. + +O2+4e - Oxygen is discharged from oxygen outlet 601 and collected through an oxygen storage tank. + The hydrogen enters through the proton exchange membrane 8 and enters at the cathode 9, where the hydrogen evolution reaction (HER) occurs: 4H + +4e - →2H2. Hydrogen gas is discharged from hydrogen outlet 1001 and collected in a hydrogen storage tank; the hydrogen purity can reach over 99.99%. A portion of the freshwater in freshwater chamber 4 is periodically discharged to maintain a low salinity. Concentrated brine is periodically discharged, with a salinity greater than 20%. The crystallized product 21 recovered through the evaporator crystallizer is a mixed salt. After 500 hours of continuous operation, from... Figure 8 and Figure 9It can be seen that the conductivity of freshwater is stable at 10 μm / cm, and the hydrogen production rate is stable at 12 m. 3 A flow rate of over / h indicates that the system can operate reliably and stably, and can directly electrolyze desulfurization wastewater 20 to produce hydrogen, thus realizing the resource utilization of desulfurization wastewater.

[0056] For the specific principles and usage methods of this device, please refer to the power plant energy storage methods section of Examples 3 and 4. The difference between Examples 3 and 4 is as follows:

[0057] ① Salt lake water and seawater taken from wind power and photovoltaic power plants need to be heated by preheating device 204, while desulfurization wastewater taken from coal-fired power plants has a high temperature and does not need to be heated.

[0058] ② The brine chamber 2 used in wind power and photovoltaic power plants is connected to the purification system 11 to purify lithium salts and rare earth resources in salt lake water and seawater, while the brine chamber 2 used in coal-fired power plants is connected to the tail heating device 12 to evaporate and crystallize and recover impurities in desulfurization wastewater.

[0059] Other details will not be elaborated further.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for producing hydrogen by electrolysis of high-salt water, characterized in that, include: The system includes a brine chamber and a freshwater chamber, which are connected by a hydrophobic and breathable membrane. The brine chamber contains hot brine, and water vapor enters the freshwater chamber through the hydrophobic and breathable membrane. The anode chamber and the cathode chamber are connected by a water-permeable and gas-barrier membrane, and by a proton exchange membrane. The anode in the anode chamber and the cathode in the cathode chamber are respectively connected to an external power source. The brine chamber is connected to the purification system or tail heating device via a brine outlet pipe. It also includes a conductivity meter connected to the freshwater chamber, and the freshwater chamber is provided with a freshwater discharge port; The freshwater outlet is connected to a circulating water pipe, which is equipped with a freshwater pump and a conductivity meter. A heat exchange system for heat exchange is located outside the circulating water pipe. The brine chamber is connected to a brine inlet pipe, through which high-salt water enters the brine chamber; The brine inlet pipe is equipped with a preheating device and a brine pump.

2. The electrolytic high-salt water hydrogen production system according to claim 1, characterized in that, An oxygen collection device is connected to the outside of the anode, and a hydrogen collection device is connected to the outside of the cathode.

3. A power plant energy storage system comprising the electrolysis high-salt water hydrogen production system of claim 2, characterized in that, The high-salinity water in the power plant area enters the brine chamber through the brine inlet pipe.

4. The power plant energy storage system according to claim 3, characterized in that, A buffer tank is provided at the upstream end of the brine inlet pipe. The buffer tank is connected to the purification system or the tail heating device through a pipeline, and a conductivity meter is provided on the connected pipeline.

5. The power plant energy storage system according to claim 4, characterized in that, The preheating device and the brine pump are connected to the power plant's power system for power supply.

6. The power plant energy storage system according to claim 5, characterized in that, The external power source includes the power plant's power system.

7. A power plant energy storage method comprising the power plant energy storage system of claim 6, characterized in that, Includes the following steps: S1, During the power surplus phase, the power plant's power system supplies power to start the preheating device and the brine pump. The high-salinity water in the power plant area is heated by the preheating device and enters the brine chamber through the brine inlet pipe. S2, the power plant's power system supplies power to start the freshwater pump. The water vapor pressure in the brine chamber is higher than that in the freshwater chamber. The water vapor passes through the hydrophobic and breathable membrane and enters the freshwater chamber. It is converted into freshwater by heat exchange through the circulating water pipe. The freshwater discharge outlet drains water periodically to avoid salt accumulation. S3, the power plant's power system supplies power to the anode, and fresh water from the freshwater chamber enters the anode chamber through the water-permeable gas-barrier membrane, where an oxygen evolution reaction occurs and the oxygen is stored in the oxygen collection device; S4, the power plant's power system supplies power to the cathode, and ions in the anode chamber enter the cathode chamber through the proton exchange membrane, where a hydrogen evolution reaction occurs, and hydrogen is stored in the hydrogen collection device; S5, the high-salinity water in the power plant area and the concentrated brine in the brine chamber are recycled by the purification system or the tail heating device.

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