Energy self-consistent system of water electrolysis hydrogen production factory

Abstract

The invention provides an energy self-consistent system of a water electrolysis hydrogen production factory, which comprises a water electrolysis hydrogen production side which comprises an electrolytic bath; the hydrogen purification equipment is connected with the electrolytic bath through a pipeline; the oxygen post-treatment device is connected with the electrolytic bath through a pipeline; a stepped energy storage tank; the energy storage side comprises a step energy storage tank, and stored energy of the step energy storage tank is transferred to the step energy storage tank through a movable energy storage vehicle; the first water tank is connected with the cascade energy storage tank through a pipeline; and the water and high-temperature hydrogen heat exchanger is used for carrying out heat exchange on the first water tank. Waste heat on the two sides of the system is more reasonably allocated through the movable energy storage vehicle, the energy utilization rate is increased, and the technical problem that in the prior art, an energy self-consistent system of an efficient heat utilization water electrolysis hydrogen production factory is lacked is solved.

Description

Technical fields:

[0001] This invention relates to the field of water electrolysis hydrogen production technology, and in particular to an energy self-sufficiency system for a water electrolysis hydrogen production plant. Background technology:

[0002] Currently, global warming and the related climate crisis have attracted worldwide attention. Hydrogen-based energy systems are a promising alternative. Hydrogen has wide applications in internal combustion engines, steam turbines, and fuel cells because it can be easily converted into mechanical, thermal, and electrical energy, thus potentially becoming an excellent energy carrier. Hydrogen can also be used in many currently available internal combustion engines with only relatively low-cost modifications. Alkaline water electrolysis can produce hydrogen simply, efficiently, and at low cost. High-purity hydrogen is obtained through this process. Utilizing hydrogen as an alternative to existing fuels and resources, combined with environmentally friendly and alternative production technologies, has the potential to significantly advance the pursuit of a sustainable energy future. This versatile energy carrier can be utilized without releasing harmful air pollutants or causing greenhouse gas emissions. However, since the conversion efficiency of hydrogen production through water electrolysis is only 60% to 75%, a considerable portion is converted into thermal energy. To maintain a stable temperature in the electrolyzer, the electrolyte is usually cooled and then recycled back to the electrolyzer. In the compressor station, low-pressure hydrogen needs to be compressed to high pressure, which also generates a lot of heat. In order to reduce the temperature of hydrogen and utilize this heat, it has become a hot issue of concern. Therefore, the recovery and utilization of these two waste heats have been extensively studied.

[0003] There is an urgent need for an energy self-sufficient system for water electrolysis hydrogen production plants, which would help solve the technical problem of the lack of an energy self-sufficient system for high-efficiency heat utilization water electrolysis hydrogen production plants in the existing technology. Summary of the Invention:

[0004] In one embodiment, the present invention provides an energy self-sufficiency system for a water electrolysis hydrogen production plant. By using a mobile energy storage vehicle, the waste heat on both sides of the system can be more rationally distributed, thereby improving energy utilization efficiency. This helps to solve the technical problem of the lack of an efficient heat utilization energy self-sufficiency system for water electrolysis hydrogen production plants in the prior art.

[0005] The energy self-sufficiency system of the water electrolysis hydrogen production plant includes:

[0006] One side of the water electrolysis hydrogen production process includes:

[0007] One electrolytic cell;

[0008] A hydrogen purification device is connected to the electrolytic cell via a pipeline.

[0009] An oxygen post-processing device is connected to the electrolytic cell via a pipeline;

[0010] A single-stage energy storage tank;

[0011] One energy storage side includes:

[0012] A cascade energy storage tank, through which the energy stored in the cascade energy storage tank is transferred to the cascade energy storage tank via a mobile energy storage vehicle;

[0013] A first water tank is connected to the cascade energy storage tank via a pipeline;

[0014] A water and high-temperature hydrogen heat exchanger is used for heat exchange in the first water tank.

[0015] In one embodiment, the energy storage side further includes:

[0016] A second water tank, which is connected to the first water tank;

[0017] The first water pump,

[0018] A heat exchanger, which introduces water into the second water tank through a pipeline, circulates the water for heat exchange, and then flows back to the second water tank;

[0019] A steam turbine that utilizes the high-temperature hot water from the heat exchanger;

[0020] A first cooler, which is connected to the steam turbine;

[0021] A second water pump, which is connected to the heat exchanger, draws water from the pipeline back to the heat exchanger.

[0022] In one embodiment, the energy storage side further includes:

[0023] A third water tank, which is connected to the first water tank;

[0024] A third water pump is connected to the third water tank;

[0025] A generator, one end of which is connected to the third water pump, and the other end of which is connected to the third water tank;

[0026] An absorber, one end of which is connected to the generator, and the other end of which is also connected to the generator, and a fourth water pump is connected in series.

[0027] A first evaporator, which is connected to the absorber;

[0028] A second cooler is connected in series between the absorber and the generator.

[0029] In one embodiment, the energy storage side further includes:

[0030] A fourth water tank, which is connected to the first water tank;

[0031] A fourth water pump, which is connected to the fourth water tank;

[0032] A second evaporator, one end of which is connected to the fourth water pump;

[0033] A compressor, which is connected to the second cooler;

[0034] A second cooler is connected to the compressor, the second cooler is connected to the second evaporator, and the other end of the second evaporator is connected to the fourth water tank.

[0035] In one embodiment, the cascade energy storage tank is connected to the fourth water tank.

[0036] In one embodiment, one end of the third water tank is connected between the cascade energy storage tank and the fourth water tank, and the other end of the third water tank is connected between the first water tank and the fourth water tank.

[0037] In one embodiment, one end of the second water tank is connected between the cascade energy storage tank and the fourth water tank.

[0038] In one embodiment, the cascade energy storage tank is fed back to the electrolytic cell via a pipeline through a fifth water pump;

[0039] Among them, the pipeline is connected in series with a temperature controller.

[0040] In one embodiment, a first throttle valve is further connected between the generator and the absorber via a pipeline;

[0041] A second throttle valve is connected in series between the second cooler and the second evaporator.

[0042] In one embodiment, the water electrolysis hydrogen production side further includes:

[0043] Two gas-liquid separators are connected in series between the electrolytic cell, the hydrogen purification equipment, and the oxygen post-treatment device, respectively. Attached image description:

[0044] Figure 1 This is a schematic diagram of an energy self-sufficiency system for a water electrolysis hydrogen production plant according to one embodiment of the present invention. Specific implementation examples:

[0045] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0047] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0048] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0049] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0050] Specific embodiments of this application are described below with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to ascertain the true intent based on the user's historical operations, and to avoid unnecessary or redundant details that would obscure this application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in various ways with substantially any suitable detailed structure.

[0051] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0052] Currently, the waste heat from biomass power generation coupled with alkaline water electrolysis to produce hydrogen mainly consists of the heat from the alkaline solution in the electrolyzer and the waste heat from the high-temperature hydrogen in the compressor station. The recovery and utilization of these two components of waste heat has been extensively studied. This patent designs a heat recovery system to collect the heat from the alkaline solution and the high-temperature hydrogen, thereby reducing dependence on fossil fuel energy resources and mitigating the environmental degradation caused by fossil fuel combustion, ultimately leading to a significant reduction in global carbon dioxide emissions and other air pollutants. Since the temperature of the alkaline solution in the electrolyzer cannot exceed 95℃, the most common method in factories is to cool the alkaline solution down using cooling water through a heat exchanger, which results in a waste of heat. To utilize this heat, this patent designs a mobile cascade phase change energy storage tank. After the alkaline solution passes through this tank, its temperature reaches the required 60 to 70℃, and this heat can be stored. The tank can then be transported by a mobile energy storage vehicle to a factory within 50km for use. A compression heat pump is used to raise the temperature of the heat transfer fluid passing through the tank to a suitable level, achieving adsorbent regeneration and providing a continuous supply of adsorbent for the hydrogen production plant. This heat can also be used in an absorption chiller to provide a cooling source for the hydrogen production plant, or in an organic Rankine cycle power generation system to provide power to the plant, ultimately achieving combined cooling, heating, and power (CCHP) for the hydrogen production plant. Since the water supply temperature in the pipeline network is around 20℃, which is too low, the cooling water after cooling the high-temperature hydrogen at the compressor station can be transported through pipelines to the inlet of the cascade energy storage tank to act as a heat transfer medium, thereby increasing the initial temperature of the heat transfer medium entering the cascade energy storage tank. This patent utilizes a movable cascade phase change energy storage tank to recover and utilize the waste heat from alkaline water electrolysis, and constructs a refrigeration and heat pump system for recovering waste heat. This achieves the goal of maintaining the normal operation of the electrolyzer and reducing dependence on fossil fuel energy resources, ultimately realizing energy self-sufficiency for the hydrogen production plant.

[0053] Figure 1 This is a schematic diagram of an energy self-sufficient system for a water electrolysis hydrogen production plant according to one embodiment of the present invention. Figure 1 As shown, in one embodiment, an energy self-sufficiency system for a water electrolysis hydrogen production plant includes:

[0054] One side of the water electrolysis hydrogen production process includes:

[0055] One electrolytic cell 1;

[0056] A hydrogen purification device 4 is connected to the electrolytic cell 1 via a pipeline;

[0057] An oxygen post-processing device 5 is connected to the electrolytic cell 1 via a pipeline;

[0058] First-stage energy storage tank 6-Ⅰ;

[0059] One energy storage side includes:

[0060] A cascade energy storage tank 6-II is used to transfer the stored energy of the cascade energy storage tank 6-I to the cascade energy storage tank 6-I via a mobile energy storage vehicle 10;

[0061] A first water tank 12 is connected to a cascade energy storage tank 6-II via a pipeline;

[0062] A water and high-temperature hydrogen heat exchanger 11 is used for heat exchange with the first water tank 12.

[0063] In one embodiment, the energy storage side further includes:

[0064] A second water tank 12-I is connected to the first water tank 12;

[0065] First water pump 9-II,

[0066] A heat exchanger 15 introduces water into the second water tank 12-I through a pipeline, and after circulating heat exchange, it flows back to the second water tank 12-I.

[0067] A steam turbine 16 utilizes the high-temperature hot water from a heat exchanger 15;

[0068] A first cooler 8-Ⅳ is connected to the steam turbine 16;

[0069] A second water pump 9-Ⅲ is connected to heat exchanger 15 to return water in the pipeline to heat exchanger 15.

[0070] In one embodiment, the energy storage side further includes:

[0071] A third water tank 12-II is connected to the first water tank 12;

[0072] A third water pump 9-Ⅳ is connected to a third water tank 12-Ⅱ;

[0073] A generator 14 is connected at one end to the third water pump 9-Ⅳ and at the other end to the third water tank 12-Ⅱ;

[0074] An absorber 19 is connected at one end to a generator 14 and at the other end to a generator 14, and is connected in series with a fourth water pump 9-V;

[0075] A first evaporator 13-II is connected to the absorber 19;

[0076] A second cooler 8-Ⅲ is connected in series between absorber 19 and generator 14.

[0077] In one embodiment, the energy storage side further includes:

[0078] A fourth water tank 12-Ⅲ is connected to the first water tank 12;

[0079] A fourth water pump 9-VI is connected to a fourth water tank 12-Ⅲ;

[0080] A second evaporator 13-I, one end of which is connected to a fourth water pump 9-VI;

[0081] A compressor 17 is connected to a second cooler 8-II;

[0082] A second cooler 8-II is connected to the compressor 17. The second cooler 8-II is connected to the second evaporator 13-I. The other end of the second evaporator 13-I is connected to the fourth water tank 12-III.

[0083] In one embodiment, the cascade energy storage tank 6-II is connected to the fourth water tank 12-III.

[0084] In one embodiment, one end of the third water tank 12-II is connected between the cascade energy storage tank 6-II and the fourth water tank 12-III, and the other end of the third water tank 12-II is connected between the first water tank 12 and the fourth water tank 12-III.

[0085] In one embodiment, one end of the second water tank 12-I is connected between the cascade energy storage tank 6-II and the fourth water tank 12-III.

[0086] In one embodiment, the cascade energy storage tank 6-Ⅰ is fed back to the electrolytic cell 1 via a pipeline through the fifth water pump 9-Ⅰ;

[0087] Among them, the pipeline is connected in series with the temperature controller 7.

[0088] In one embodiment, a first throttle valve 18-Ⅲ is also connected between the generator 14 and the absorber 19 via a pipeline;

[0089] A second throttle valve 18-I is connected in series between the second cooler 8-II and the second evaporator 13-I.

[0090] In one embodiment, the water electrolysis hydrogen production side further includes:

[0091] Two gas-liquid separators, 2-Ⅰ and 2-Ⅱ, are connected in series between the electrolytic cell 1 and the hydrogen purification equipment 4, and the oxygen post-treatment device 5, respectively.

[0092] This patent relates to an energy-self-sufficient system for a hydrogen production plant, comprising a water electrolysis hydrogen production unit, a heat storage / release unit, a compressor station cooling high-temperature hydrogen unit, a compression heat pump unit, an absorption refrigeration unit, and an organic Rankine cycle power generation unit. The water electrolysis hydrogen production unit primarily involves electrolyzing alkaline solutions to produce hydrogen and oxygen. The heat storage / release unit stores heat through cascaded energy storage tanks and then transports this heat to the required site using mobile energy storage vehicles. The compression heat pump unit, absorption refrigeration unit, and organic Rankine cycle power generation unit are used to recover waste heat from the electrolyte and heat generated by the high-temperature hydrogen in the compressor station, and respectively provide heat, cooling, and electricity to the outside world.

[0093] The electrolyzer 1, gas-liquid separator 2, cascade energy storage tank 6, temperature controller 7, cooler 8, and circulation pump 9 are connected by electrolyte to form a water electrolysis hydrogen production unit. The high-temperature electrolyte in the electrolyzer 1 flows to the gas-liquid separator 2 through pipelines, and the high-temperature electrolyte in the gas-liquid separator 2 flows to the cascade energy storage tank 6. The cooled electrolyte flows back to the electrolyzer 1 through the circulation pump 9. The gas in the gas-liquid separator 2 flows into the gas diaphragm valve 3, and finally the gas flows through the gas diaphragm valve 3 to the hydrogen purification device 4 and the oxygen post-treatment device 5, respectively.

[0094] The heat storage / release unit uses a mobile energy storage vehicle to move the cascade heat storage tank 6 from the water electrolysis hydrogen production side to the site where heat is needed; the compressor station cooling high-temperature hydrogen unit receives municipal water from the heat exchanger 11, and part of the water flowing out of the heat exchanger 11 flows to the cooling tower, while the other part flows to the water tank 12. The water in the water tank 12 flows into the cascade energy storage tank 6-II, and the high-temperature water flowing out of the cascade energy storage tank 6-II flows to the water tanks 12-I, 12-II, and 12-III respectively. Finally, the water in these three water tanks flows back to 12.

[0095] The compression heat pump unit receives hot water from water tank 12-Ⅲ via circulating water pump 9-Ⅵ into evaporator 13-Ⅰ, and the cooled water flows back into water tank 12-Ⅲ. The liquid in the compression heat pump exchanges heat with high-temperature water in evaporator 13-Ⅰ and then flows into compressor 17. The compressed gas flows into cooler 8-Ⅱ, and after cooler 8-Ⅱ cools the gas into liquid, it returns to evaporator 13-Ⅰ via throttling valve 18-Ⅰ.

[0096] In the absorption refrigeration unit, hot water from water tank 12-II flows into generator 14 via circulating water pump 9-Ⅳ, and the cooled water flows back into water tank 12-II. In the absorption refrigeration cycle, the refrigerant exchanges heat with the high-temperature water in generator 14 and then flows into condenser 8-Ⅲ. The refrigerant flowing out of condenser 8-Ⅲ flows into expansion valve 18-Ⅱ, and the refrigerant after passing through expansion valve 18-Ⅱ flows into evaporator 13-Ⅱ, thus forming a complete absorption refrigeration cycle process.

[0097] In the organic Rankine cycle power generation unit, hot water from water tank 12-I flows into heat exchanger 15 via circulating water pump 9-II, and the cooled water flows into water tank 12-I. The circulating agent on the organic Rankine cycle power generation side exchanges heat with high-temperature water in heat exchanger 15 and then flows into steam turbine 16. The circulating agent flowing out of steam turbine 16 flows into cooler 8-IV, and the circulating agent flows back into heat exchanger 15 via circulating water pump 9-III.

[0098] The energy self-sufficiency scheme of the water electrolysis hydrogen production plant of the present invention will be further explained below:

[0099] When the electrolyte in electrolyzer 1 of the hydrogen electrolysis unit is energized, it is electrolyzed to produce hydrogen and oxygen. Since the electrical energy cannot be fully used for the electrochemical reaction, some of the electrical energy will inevitably be converted into heat energy, causing the electrolyte temperature to rise. The gas-liquid mixture will then enter the gas-liquid separator 2. The high-temperature liquid flowing out after the gas-liquid separator 2 provides heat to the cascade heat storage tank. When the temperature controller 7 detects that the temperature at the outlet of the cascade heat storage tank exceeds 75°C, the cooler 8-I is activated to cool the electrolyte. This also indicates that the cascade heat storage tank has reached its maximum heat storage capacity and can be replaced with a new cascade heat storage tank for heat storage. When replacing the heat storage device, in order not to affect the normal operation of electrolyzer 1, the cooling required by the electrolyte is provided by the cooler 8-I. Subsequently, the replacement cascade heat storage tank is transported by a mobile energy storage vehicle to the required site to achieve the purpose of heating, cooling and power supply.

[0100] Hydrogen production plants need to compress low-pressure hydrogen into high-pressure hydrogen. During the compression process, a large amount of heat is generated. To utilize this heat, municipal water at around 20°C can be fed into heat exchanger 11 to cool the high-temperature hydrogen. The water coming out of heat exchanger 11 will reach around 35°C. Part of the water flowing out of heat exchanger 11 flows to cooling tower for circulation cooling, while the other part flows into water tank 12 to utilize this heat. The water flowing out of water tank 12 passes through a stepped heat storage tank, and the water temperature will rise further. This high-temperature water is then sent to the compression heat pump unit, absorption refrigeration unit, and organic Rankine cycle power generation unit to drive the normal operation of the units. The utilized high-temperature water will return to water tank 12, and this cycle will continue.

[0101] In the compression heat pump unit, the refrigerant absorbs heat and vaporizes into a high-temperature gas in the evaporator 13-I. This gas is then compressed into a high-temperature, high-pressure gas by the compressor 17, and the condenser 8-II supplies this heat to the heat user. In the absorption refrigeration unit, the refrigerant absorbs heat and vaporizes into a high-temperature gas in the generator 14. After passing through the condenser 8-III and the expansion valve 18-II, it transforms into a low-temperature, low-pressure liquid. This low-temperature, low-pressure liquid flows to the evaporator 13-II, which supplies this cooling capacity to the cold user. The liquid flowing out of the evaporator 13-II is absorbed by the absorber 19. The concentrated solution in the absorber 19 is sent to the generator 14 by the circulating pump 9-V, and the dilute solution in the generator 14 enters the absorber 19. This process is repeated to achieve a refrigeration cycle. In the organic Rankine cycle power generation unit, the refrigerant absorbs heat and vaporizes into a high-temperature gas in the heat exchanger 15. This high-temperature gas drives the steam turbine 16, which in turn drives the generator to provide power to the user.

[0102] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. An energy self-sufficient system for a water electrolysis hydrogen production plant, characterized in that, The energy self-sufficiency system of the water electrolysis hydrogen production plant includes: One side of the water electrolysis hydrogen production process includes: One electrolytic cell (1); A hydrogen purification device (4) is connected to the electrolytic cell (1) via a pipeline; An oxygen post-processing device (5) is connected to the electrolytic cell (1) via a pipeline; A single-stage energy storage tank (6-Ⅰ); One energy storage side includes: A cascade energy storage tank (6-Ⅱ) is used to transfer the energy stored in the cascade energy storage tank (6-Ⅰ) to the cascade energy storage tank (6-Ⅰ) via a mobile energy storage vehicle (10); A first water tank (12) is connected to the stepped energy storage tank (6-II) via a pipeline; A water and high-temperature hydrogen heat exchanger (11) is used to exchange heat with the first water tank (12).

2. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 1, characterized in that, The energy storage side also includes: A second water tank (12-Ⅰ) is connected to the first water tank (12); First water pump (9-II), A heat exchanger (15) introduces water into the second water tank (12-Ⅰ) through a pipeline, and then circulates and exchanges heat before flowing back to the second water tank (12-Ⅰ); A steam turbine (16) that utilizes the high-temperature hot water from the heat exchanger (15); A first cooler (8-Ⅳ) is connected to the steam turbine (16); A second water pump (9-Ⅲ), which is connected to the heat exchanger (15), draws water from the pipeline back to the heat exchanger (15).

3. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 2, characterized in that, The energy storage side also includes: A third water tank (12-Ⅱ) is connected to the first water tank (12); A third water pump (9-Ⅳ) is connected to the third water tank (12-Ⅱ); A generator (14) is connected at one end to the third water pump (9-Ⅳ) and at the other end to the third water tank (12-Ⅱ); An absorber (19) is connected at one end to the generator (14) and at the other end to the generator (14), and is connected in series with a fourth water pump (9-V); A first evaporator (13-II) is connected to the absorber (19); A second cooler (8-Ⅲ) is connected in series between the absorber (19) and the generator (14).

4. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 3, characterized in that, The energy storage side also includes: A fourth water tank (12-Ⅲ) is connected to the first water tank (12); A fourth water pump (9-VI) is connected to the fourth water tank (12-Ⅲ); A second evaporator (13-Ⅰ), one end of which is connected to the fourth water pump (9-Ⅵ); A compressor (17) is connected to the second cooler (8-II); A second cooler (8-II) is connected to the compressor (17), the second cooler (8-II) is connected to the second evaporator (13-I), and the other end of the second evaporator (13-I) is connected to the fourth water tank (12-III).

5. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 4, characterized in that, The cascade energy storage tank (6-Ⅱ) is connected to the fourth water tank (12-Ⅲ).

6. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 5, characterized in that, One end of the third water tank (12-Ⅱ) is connected between the cascade energy storage tank (6-Ⅱ) and the fourth water tank (12-Ⅲ), and the other end of the third water tank (12-Ⅱ) is connected between the first water tank (12) and the fourth water tank (12-Ⅲ).

7. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 6, characterized in that, One end of the second water tank (12-Ⅰ) is connected between the cascade energy storage tank (6-Ⅱ) and the fourth water tank (12-Ⅲ).

8. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 7, characterized in that, The cascade energy storage tank (6-Ⅰ) is fed back to the electrolytic cell (1) via a pipeline through the fifth water pump (9-Ⅰ); Among them, the pipeline is connected in series with a temperature controller (7).

9. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 8, characterized in that, A first throttle valve (18-Ⅲ) is also connected between the generator (14) and the absorber (19) via a pipeline; A second throttle valve (18-I) is connected in series between the second cooler (8-II) and the second evaporator (13-I).

10. The energy self-sufficiency system of the water electrolysis hydrogen production plant according to claim 9, characterized in that, The hydrogen production side of water electrolysis also includes: Two gas-liquid separators (2-Ⅰ) and (2-Ⅱ) are connected in series between the electrolytic cell (1), the hydrogen purification device (4), and the oxygen post-treatment device (5), respectively.

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