Water electrolysis hydrogen production system

Abstract

The utility model relates to a water electrolysis hydrogen production system. The water electrolysis hydrogen production system comprises a plurality of electrolysis units. The electrolysis unit comprises an inlet end, an outlet end, an electrolytic bath array and a first gas-liquid separation device, the electrolytic bath array and the first gas-liquid separation device are arranged between the inlet end and the outlet end in series, the electrolytic bath array comprises a plurality of alkaline water electrolytic baths arranged in parallel, and the alkaline water electrolytic baths are used for electrolyzing alkaline liquor to generate a gas-liquid mixture; the first gas-liquid separation device is used for separating hydrogen, oxygen and alkali liquor in the gas-liquid mixture and discharging the alkali liquor from the outlet end. Wherein in the plurality of electrolysis units, the outlet end of at least one electrolysis unit is communicated with the inlet end of another electrolysis unit. According to the water electrolysis hydrogen production system, the energy utilization rate can be increased, heat energy and electric energy loss can be effectively reduced under the scenes of wind power fluctuation and the like, and stability and adaptability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrolytic water, in particular to an electrolytic water hydrogen production system. BACKGROUND

[0002] In recent years, with the gradual reduction of renewable energy costs, the demand for hydrogen production by renewable energy has increased significantly. Electrolytic cell array is the core equipment for converting electricity into hydrogen, and is used more and more widely.

[0003] In the scenario of hydrogen production by wind power, the fluctuating input of wind power makes the electrolytic water hydrogen production system in a non-stable working state. The multiple electrolytic units of the electrolytic water hydrogen production system are in different working states, and the working conditions of heat management are relatively complex. There is waste of heat energy and electric energy in the process of heat management. Making full use of the heat source and cold source outside the electrolytic water hydrogen production system can improve the thermal efficiency of the electrolytic water hydrogen production system and reduce energy loss. CONTENT OF THE UTILITY MODEL

[0004] The embodiment of the present application provides an electrolytic water hydrogen production system which can effectively reduce the waste of heat energy and electric energy and improve stability and adaptability.

[0005] According to the embodiment of the present application, an electrolytic water hydrogen production system is provided, which comprises multiple electrolytic units. The electrolytic unit comprises an inlet end, an outlet end, and an electrolytic cell array and a first gas-liquid separation device arranged in series between the inlet end and the outlet end. The electrolytic cell array comprises multiple alkaline water electrolytic cells arranged in parallel. The alkaline water electrolytic cell is used for electrolyzing alkaline solution to generate a gas-liquid mixture. The first gas-liquid separation device is used for separating hydrogen and oxygen in each gas-liquid mixture and the alkaline solution, and discharging the alkaline solution from the outlet end. Among them, the outlet end of at least one electrolytic unit in the multiple electrolytic units is in communication with the inlet end of another electrolytic unit.

[0006] According to an aspect of the embodiment of the present application, the outlet ends of the multiple electrolytic units are in communication with each other, and the inlet ends of the multiple electrolytic units are in communication with each other. The electrolytic water hydrogen production system further comprises a circulation pipeline, and the outlet end of each electrolytic unit is connected to the inlet end of each electrolytic unit through the circulation pipeline.

[0007] According to an aspect of the embodiment of the present application, the electrolytic water hydrogen production system comprises a first heat exchange unit, and the first heat exchange unit is arranged in the circulation pipeline and is used for adjusting the temperature of the alkaline solution in the circulation pipeline to a preset temperature.

[0008] According to an aspect of the embodiment of the present application, the first heat exchange unit comprises a refrigeration module and a heat exchange module. The first heat exchange unit further comprises a temperature sensor and a control device. The temperature sensor is used for detecting the temperature of the alkaline solution in the circulation pipeline, and the control device is configured to control one of the refrigeration module and the heat exchange module to be turned on according to the temperature of the alkaline solution and the preset temperature.

[0009] According to an aspect of the embodiments of the present application, the water electrolysis hydrogen production system further comprises a liquid storage device, the liquid storage device is arranged in the circulation pipeline, and the alkali liquor at the outlet end of each electrolysis unit flows into the liquid storage device and is connected to the inlet end of each electrolysis unit through the liquid storage device.

[0010] According to an aspect of the embodiments of the present application, the water electrolysis hydrogen production system further comprises a second heat exchange unit, the second heat exchange unit is connected to the liquid storage device and is used for heat preservation or heating of the alkali liquor in the liquid storage device.

[0011] According to an aspect of the embodiments of the present application, the water electrolysis hydrogen production system further comprises a second gas-liquid separation device, the second gas-liquid separation device is arranged in the circulation pipeline and is used for gas-liquid separation of the alkali liquor in the circulation pipeline.

[0012] According to an aspect of the embodiments of the present application, each first gas-liquid separation device is provided with a control switch, and the control switch is configured to control the start and stop of the first gas-liquid separation device.

[0013] According to an aspect of the embodiments of the present application, each alkaline water electrolysis cell comprises a sub-inlet and a sub-outlet, the sub-inlet of each alkaline water electrolysis cell is connected to the inlet end of the electrolysis unit, and the sub-outlet of each alkaline water electrolysis cell is connected to the first gas-liquid separation device. The electrolysis cell array further comprises a plurality of first valves and a plurality of second valves, each first valve is matched to the sub-inlet of one alkaline water electrolysis cell, and each second valve is matched to the sub-outlet of one alkaline water electrolysis cell.

[0014] According to an aspect of the embodiments of the present application, the sub-outlet of the alkaline water electrolysis cell comprises a hydrogen side outlet and an oxygen side outlet, the first gas-liquid separation device comprises a first hydrogen separation device and a first oxygen separation device, the first hydrogen separation device is connected to the hydrogen side outlet and separates hydrogen and alkali liquor, the first oxygen separation device is connected to the oxygen side outlet and separates oxygen and alkali liquor, and the alkali liquor separated by the first hydrogen separation device and the first oxygen separation device is discharged from the outlet end of the electrolysis unit.

[0015] The water electrolysis hydrogen production system provided by the embodiments of the present application comprises a plurality of electrolysis units, the outlet end of at least one electrolysis unit is connected to the inlet end of another electrolysis unit, and the alkali liquor of at least two electrolysis units is circulated and communicated. Under the condition of power fluctuation, the alkali liquor flowing out of the outlet end of the electrolysis unit in the power-on working state can be circulated into the electrolysis unit in the non-working state, the heat of the alkali liquor is used to heat preservation of the electrolysis unit in the non-working state, the electrolysis unit is in a hot standby state, the response speed of the electrolysis unit in the non-working state is improved, the heat capacity of the electrolysis unit in the non-working state is used to naturally cool the alkali liquor, the power consumption for cooling the alkali liquor is reduced, the energy utilization rate is improved, and the stability and adaptability of the water electrolysis hydrogen production system to power fluctuation are improved. Attached Figure Description

[0016] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0017] Fig. 1 These are schematic diagrams of some water electrolysis hydrogen production systems provided in the embodiments of this application;

[0018] Fig. 2 These are schematic diagrams of other water electrolysis hydrogen production systems provided in the embodiments of this application.

[0019] in:

[0020] 100-Electrolysis of water to produce hydrogen system;

[0021] 10-Electrolysis unit; 10a-First electrolysis unit; 10b-Second electrolysis unit; 20-First heat exchange unit; 210-Refrigeration module; 220-Heat exchange module; 30-Liquid storage device; 40-Second gas-liquid separation device; 410-Second hydrogen separation device; 420-Second oxygen separation device; 50-Second heat exchange unit;

[0022] 1-Alkaline water electrolysis cell; 2-First gas-liquid separation device; 21-First hydrogen separation device; 22-First oxygen separation device; 3-First valve; 4-Second valve.

[0023] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0024] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples. In the accompanying drawings and the following description, at least well-known structures and techniques of the regions are not shown to avoid unnecessarily obscuring the application; and, for clarity, the dimensions of the regional structures may be exaggerated. Furthermore, the features, structures, or characteristics described below can be combined in any suitable manner in one or more embodiments.

[0025] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the water electrolysis hydrogen production system of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] To facilitate understanding of the technical solution of this application, the following description is provided in conjunction with the appendix. Figs. 1-2 The water electrolysis hydrogen production system in the embodiments of this application will be described in detail.

[0027] Please see Fig. 1 , Fig. 1 This illustration shows a schematic diagram of a water electrolysis hydrogen production system 100 provided in some embodiments of this application. Embodiments of this application provide an water electrolysis hydrogen production system 100, which includes multiple electrolysis units 10. Each electrolysis unit 10 includes an inlet end, an outlet end, an electrolyzer array and a first gas-liquid separation device 2 connected in series between the inlet end and the outlet end. The electrolyzer array includes multiple alkaline water electrolyzers 1 connected in parallel.

[0028] Electrolysis unit 10 introduces an aqueous solution containing electrolyte, i.e., alkaline solution, at its inlet. The alkaline solution flows into multiple alkaline water electrolysis cells 1 connected in parallel. Each alkaline water electrolysis cell 1 is used to electrolyze the alkaline solution to generate a gas-liquid mixture. Specifically, when energized, the alkaline solution undergoes an electrolytic reaction. In the cathode region of the alkaline water electrolysis cell 1, it gains electrons and is reduced to generate hydrogen gas; in the anode region, it loses electrons and is oxidized to generate oxygen gas. After the electrolytic reaction, the hydrogen and oxygen generated in the multiple alkaline water electrolysis cells 1 mix in the alkaline solution to form a gas-liquid mixture, which is then transported together to the first gas-liquid separation device 2 for gas-liquid separation.

[0029] The first gas-liquid separation device 2 is used to separate the target gas and alkaline solution from the gas-liquid mixture. Multiple alkaline water electrolyzers 1 share the same first gas-liquid separation device 2. The gas-liquid mixture transported by the multiple alkaline water electrolyzers 1 will undergo gas-liquid separation in the first gas-liquid separation device 2 to separate the target hydrogen or target oxygen from the gas-liquid mixture, and the alkaline solution will be output from the outlet end of the water electrolysis hydrogen production system 100. Among them, the alkaline solution separated by the first gas-liquid separation device 2 can be processed and returned to the inlet end of the electrolysis unit 10 to realize the circulation of alkaline solution.

[0030] It can be understood that by arranging multiple electrolytic units 10, the electrolytic unit 10 can be taken as a standardized unit, which includes multiple alkaline water electrolysis cells 1 and a set of first gas-liquid separation devices 2. The electrolytic unit 10 can be expanded according to production requirements to configure different numbers of alkaline water electrolysis cells 1 to achieve different production capacities. This arrangement can facilitate the installation, disassembly and maintenance of individual alkaline water electrolysis cells 1.

[0031] In the wind power hydrogen production scenario or other hydrogen production occasions, due to the fluctuating input of wind power, the water electrolysis hydrogen production system 100 will be in a non-steady state. For example, in the case of wind, the electrolytic units 10 can all be in a working state. In the case of no wind, the electrolytic units 10 can all be in a non-working state. In the case of insufficient wind to produce hydrogen, the electrolytic units 10 can be partially in a non-working state and partially in a working state (for example, the electrolytic units 10 include first electrolytic units 10a and second electrolytic units 10b, the first electrolytic units 10a are in a working state, and the second electrolytic units 10b are in a shutdown state). It can be understood that for electrolytic units 10 in different working states, different heat management measures need to be taken, and the working conditions of heat management are relatively complex.

[0032] For electrolytic units 10 in a working state, due to the heat effect of the power supply of the alkaline water electrolysis cell 1, the temperature of the alkaline solution increases during the electrolysis process, and the outlet temperature of the alkaline solution is higher than the inlet temperature. The alkaline water electrolysis cell needs to ensure the stability of the outlet temperature of the alkaline solution under normal working conditions, so additional refrigeration equipment is needed to reduce the inlet temperature of the alkaline solution of the electrolytic unit 10 to a suitable temperature, ensuring the stability of the outlet temperature of the alkaline solution after flowing through the alkaline water electrolysis cell 1. For electrolytic units 10 in a non-working state, when they are started, a long time and energy are consumed to heat the alkaline solution to a suitable temperature. Therefore, in the above heat management process, heat and electricity will be wasted.

[0033] To solve the above problems, the water electrolysis hydrogen production system 100 provided by the embodiments of the present application is arranged in multiple electrolytic units 10, and the outlet end of at least one electrolytic unit 10 is connected to the inlet end of another electrolytic unit 10 through a liquid storage device, so as to circulate and communicate the alkaline solutions of at least two electrolytic units 10.

[0034] It should be noted that in the water electrolysis hydrogen production system 100 of the embodiments of the present application, the balance and exchange of heat occur between different electrolytic units 10. That is, the present application takes the electrolysis cell array formed by multiple parallel alkaline water electrolysis cells 1 and the connected first gas-liquid separation devices 2 as an electrolytic unit 10, and performs the balance and exchange of heat between multiple electrolytic units 10 included in the water electrolysis hydrogen production system 100.

[0035] For different electrolytic units 10, due to the fluctuation of wind power, part of the electrolytic units 10 can be in working state, and part of the electrolytic units 10 can be in non-working state. Therefore, by connecting at least two electrolytic units 10, heat balance and exchange can be achieved between the electrolytic units 10 in working state and the electrolytic units 10 in non-working state. That is, under the condition of power fluctuation, the alkali solution flowing out of the outlet end of the electrolytic unit 10 in working state can be circulated into the electrolytic unit 10 in non-working state to utilize the waste heat of the alkali solution to keep the electrolytic unit 10 in non-working state, so that the electrolytic unit 10 is in a hot standby state, improves the response speed of the electrolytic unit 10 in non-working state, and also utilizes the heat capacity of the electrolytic unit 10 in non-working state to naturally cool the alkali solution, reduces the power loss required for cooling the alkali solution, thereby improving the energy utilization rate and the stability and adaptability of the water electrolysis hydrogen production system 100 to power fluctuation. At the same time, the liquid storage device 30 is provided, and the high specific heat of the large volume of liquid reduces the temperature fluctuation of the alkali solution.

[0036] It can be understood that the outlet end of at least one electrolytic unit 10 and the inlet end of another electrolytic unit 10 are in communication with each other, which can be that the outlet end of one electrolytic unit 10 and the inlet end of another electrolytic unit 10 are in communication to form a series structure, or the outlet end of one electrolytic unit 10 and the outlet end of another electrolytic unit 10 are in communication to form a parallel structure, that is, the circulation communication requirement of multiple electrolytic units 10 can be met.

[0037] Optionally, the number of electrolytic units 10 can be two, three or even more. When the number of electrolytic units 10 is three or more (not shown in the figure), each electrolytic unit 10 can be in communication with each other, or part of the multiple electrolytic units 10 can be in communication with each other.

[0038] For the convenience of understanding, the water electrolysis hydrogen production system 100 only includes two electrolytic units 10, i.e., the first electrolytic unit 10a and the second electrolytic unit 10b.

[0039] In some optional embodiments, the outlet ends of the multiple electrolytic units 10 are in communication with each other, and the inlet ends of the multiple electrolytic units 10 are in communication with each other. The water electrolysis hydrogen production system 100 further includes a circulation pipeline, and the outlet end of each electrolytic unit 10 is connected to the inlet end of each electrolytic unit 10 through the circulation pipeline.

[0040] That is, the first electrolytic unit 10a and the second electrolytic unit 10b can be arranged in parallel. Taking the first electrolytic unit 10a in working state and the second electrolytic unit 10b in non-working state as an example, the temperature of the alkali liquor at the outlet end of the first electrolytic unit 10a is T1, and the temperature of the alkali liquor at the outlet end of the second electrolytic unit 10b is T2, T2 is less than T1. Therefore, when the outlet ends of the first electrolytic unit 10a and the second electrolytic unit 10b are connected to each other, the alkali liquor at the outlet ends of the first electrolytic unit 10a and the second electrolytic unit 10b will be mixed in the circulation pipeline, and the temperature of the mixed alkali liquor will reach T3, T3 is less than T1 and greater than T2. The mixed alkali liquor is then circulated back to the inlet ends of the first electrolytic unit 10a and the second electrolytic unit 10b. In the above process, the temperature of the alkali liquor injected into the inlet end of the first electrolytic unit 10a can be reduced, and the waste heat of the alkali liquor at the outlet end of the first electrolytic unit 10a can be reasonably utilized, so that the second electrolytic unit 10b is in a hot standby state, thereby significantly improving the energy utilization rate and the stability and adaptability of the water electrolysis hydrogen production system 100 to power fluctuations.

[0041] In some optional embodiments, the water electrolysis hydrogen production system comprises a first heat exchange unit 20, which is arranged in the circulation pipeline and is used to adjust the temperature of the alkali liquor in the circulation pipeline to a preset temperature.

[0042] It can be understood that, in some embodiments, when the temperature T1 of the alkali liquor at the outlet end of the first electrolytic unit 10a is 90°C, and the preset temperature T4 of the alkali liquor required to be injected into the inlet end of the first electrolytic unit 10a is 70°C, for example, after the alkali liquor at the outlet ends of the first electrolytic unit 10a and the second electrolytic unit 10b is mixed in the circulation pipeline, the temperature of the alkali liquor in the circulation pipeline, i.e. the temperature T3 of the mixed alkali liquor, may have a difference from T4.

[0043] Therefore, by arranging the first heat exchange unit 20, the temperature T3 of the mixed alkali liquor can be adjusted to the preset temperature T4, and then injected into the inlet end of the first electrolytic unit 10a, so as to improve the electrolysis efficiency, prolong the service life of the alkaline water electrolysis cell 1, and improve the reliability during operation.

[0044] Optionally, the first heat exchange unit 20 can include at least one of a heat exchanger, a refrigerator, a mechanical temperature controller, an electronic temperature controller, and a PID temperature controller.

[0045] As an optional implementation, the first heat exchange unit 20 includes a refrigeration module 210 and a heat exchange module 220. The first heat exchange unit 20 further includes a temperature sensor for detecting the temperature of the alkali liquor in the circulation pipeline, and a control device configured to control one of the refrigeration module 210 and the heat exchange module 220 to be turned on according to the temperature of the alkali liquor and the preset temperature.

[0046] When the temperature sensor detects that the temperature T3 of the alkali solution in the circulation pipeline is greater than the preset temperature T4, the control device can control the refrigeration module 210 of the first heat exchange unit 20 to be turned on to cool the temperature T3 of the alkali solution in the circulation pipeline to the preset temperature T4. When the temperature sensor detects that the temperature T3 of the alkali solution in the circulation pipeline is less than the preset temperature T4, the control device can control the heat exchange module 220 of the first heat exchange unit 20 to be turned on to heat the temperature T3 of the alkali solution in the circulation pipeline to the preset temperature T4.

[0047] It should be noted that the heat exchange module 220 can be connected with an external system, and the heat exchange module 220 can heat the alkali solution in the circulation pipeline by using the waste heat of the external system, without actively consuming additional energy for heating, thereby saving energy and reducing consumption.

[0048] By including the refrigeration module 210 and the heat exchange module 220 in the first heat exchange unit 20, the temperature of the inlet end of each electrolysis unit 10 can be reliably adjusted to the preset temperature T4, thereby improving the electrolysis efficiency, prolonging the service life of the alkaline water electrolysis tank 1, and improving the reliability during operation.

[0049] In some optional embodiments, the electrolytic water hydrogen production system further comprises a liquid storage device 30, which is arranged in the circulation pipeline, and the alkali solution at the outlet end of each electrolysis unit 10 flows into the liquid storage device 30 and is connected to the inlet end of each electrolysis unit 10 through the liquid storage device 30.

[0050] The liquid storage device 30 refers to a container with a storage space, which can be used to store part of the alkali solution. By arranging the liquid storage device 30 in the circulation pipeline, the storage capacity of the alkali solution can be increased, and in the case of wind power fluctuation, the liquid storage device 30 can be used to supplement the alkali solution in time, thereby ensuring the normal operation of the electrolytic water hydrogen production system 100. In addition, since the liquid storage device 30 stores the alkali solution with a certain amount of heat, the liquid storage device 30 can also be improved in structure and used as a heat storage device to further improve the comprehensive utilization rate of energy. The high specific heat of the large-volume liquid can reduce the temperature fluctuation of the alkali solution.

[0051] Optionally, in actual production, water or alkali solution can be supplemented into the liquid storage device 30 to make up for the consumption of water or alkali solution during the electrolytic water hydrogen production process, thereby improving the reliability of the electrolytic water hydrogen production system 100 during operation.

[0052] Optionally, the liquid storage device 30 can be a liquid storage tank.

[0053] In some alternative embodiments, the water electrolysis hydrogen production system further comprises a second heat exchange unit 50, which is connected to the liquid storage device 30 and used for heat preservation or heating of the alkali solution in the liquid storage device 30. The second heat exchange unit 50 can use external waste heat to heat or heat preserve the alkali solution in the liquid storage device 30, thereby saving energy and reducing consumption.

[0054] The heat exchange module 220 of the first heat exchange unit 20 and the second heat exchange unit 50 can share the same heat source of an external system. The first heat exchange unit 20 and the second heat exchange unit 50 are respectively arranged in different regions of the circulation pipeline. The first heat exchange module 220 is arranged in the circulation pipeline and is used for heating the alkali solution in the circulation pipeline. The alkali solution in the circulation pipeline is heated faster, so that the alkali solution in the circulation pipeline can be heated faster to the rated inlet temperature in the scene requiring a quick cold start. The second heat exchange unit 50 is arranged in the liquid storage device 30 and is used for heating or heat preserving the alkali solution in the liquid storage device 30, so as to better maintain the temperature in the circulation pipeline, thereby better utilizing external waste heat, saving energy and reducing consumption.

[0055] For each electrolysis unit 10, in some alternative embodiments, each alkaline water electrolysis cell 1 comprises a sub-inlet and a sub-outlet. The sub-inlet of each alkaline water electrolysis cell 1 is connected to the inlet end of the electrolysis unit 10, and the sub-outlet of each alkaline water electrolysis cell 1 is connected to the first gas-liquid separation device 2.

[0056] Since the multiple alkaline water electrolysis cells 1 of each electrolysis unit 10 are connected in parallel with each other, and after the alkali solution enters the inlet end of the electrolysis unit 10, branch paths are formed to respectively enter the sub-inlets of the alkaline water electrolysis cells 1. The alkali solution undergoes an electrolysis reaction in the alkaline water electrolysis cells 1 to generate a gas-liquid mixture, which is output from the sub-outlets of the alkaline water electrolysis cells 1 to the first gas-liquid separation device 2.

[0057] The electrolysis cell array further comprises multiple first valves 3 and multiple second valves 4. Each first valve 3 is matched to be connected to the sub-inlet of one alkaline water electrolysis cell 1, and each second valve 4 is matched to be connected to the sub-outlet of one alkaline water electrolysis cell 1.

[0058] Since the multiple alkaline water electrolysis cells 1 of the electrolysis cell array are arranged in parallel, by matching the electrolysis cell array to be provided with the first valve 3 and the second valve 4 corresponding to each alkaline water electrolysis cell 1, the individual closing of each alkaline water electrolysis cell 1 can be controlled, so that when any alkaline water electrolysis cell 1 has an abnormal condition, the individual maintenance of the alkaline water electrolysis cell 1 can be realized without affecting the operation of other alkaline water electrolysis cells 1, thereby improving the reliability of the operation of the water electrolysis hydrogen production system 100.

[0059] In some alternative embodiments, the sub-outlet of the alkaline water electrolysis cell 1 comprises a hydrogen side outlet and an oxygen side outlet.

[0060] The side of the alkaline water electrolyzer 1 where hydrogen is generated is referred to as a hydrogen side. Corresponding to the hydrogen side, the side where oxygen is generated is referred to as an oxygen side. The sub outlets of the alkaline water electrolyzer 1 include a hydrogen side outlet and an oxygen side outlet, and the alkaline water electrolyzer 1 outputs a gas-liquid mixture of hydrogen and alkaline solution from the hydrogen side outlet and outputs a gas-liquid mixture of oxygen and alkaline solution from the oxygen side outlet.

[0061] The hydrogen side outlet and the oxygen side outlet can be respectively provided with a second valve 4.

[0062] The first gas-liquid separation device 2 includes a first hydrogen separation device 21 and a first oxygen separation device 22. The first hydrogen separation device 21 is connected to the hydrogen side outlet and separates hydrogen and alkaline solution, and the first oxygen separation device 22 is connected to the oxygen side outlet and separates oxygen and alkaline solution. The alkaline solution separated by the first hydrogen separation device 21 and the first oxygen separation device 22 is discharged from the outlet end of the electrolysis unit 10.

[0063] Referring to Fig. 2 , Fig. 2 A schematic diagram of an electrolytic water hydrogen production system 100 provided by another embodiment of the present application is shown.

[0064] In some optional embodiments, the electrolytic water hydrogen production system further includes a second gas-liquid separation device 40, which is arranged in the circulation pipeline and is used for secondary gas-liquid separation of the alkaline solution in the circulation pipeline.

[0065] The first gas-liquid separation device 2 of each electrolysis unit 10 can be used as a sub gas-liquid separation device, and the second gas-liquid separation device 40 can be used as a total gas-liquid separation device. By arranging the second separation device in the circulation pipeline, the mixed alkaline solution after the first electrolysis unit 10a and the second electrolysis unit 10b can be further separated by the second gas-liquid separation device 40 after the gas-liquid separation of the gas-liquid mixture by the first gas-liquid separation device 2 of each electrolysis unit 10a and 10b, thereby improving the efficiency of gas-liquid separation and reducing the gas content in the alkaline solution.

[0066] Similarly to the first gas-liquid separation device 2, the second gas-liquid separation device 40 also includes a second hydrogen separation device 410 and a second oxygen separation device 420.

[0067] Further, the outlet end of the electrolysis unit 10 includes a hydrogen side outlet end and an oxygen side outlet end, the hydrogen side outlet end refers to the outlet end connected with the first hydrogen separation device 21, and the oxygen side outlet end refers to the outlet end connected with the first oxygen separation device 22. The hydrogen side outlet ends of the first electrolysis unit 10a and the second electrolysis unit 10b are communicated and connected with the second hydrogen separation device 410, so as to further separate the hydrogen in the alkali solution through the second hydrogen separation device 410. The oxygen side outlet ends of the first electrolysis unit 10a and the second electrolysis unit 10b are communicated and connected with the second oxygen separation device 420, so as to further separate the oxygen in the alkali solution through the second oxygen separation device 420.

[0068] Optionally, the second gas-liquid separation device 40 can be arranged between the outlet end of the electrolysis unit 10 and the liquid storage device 30, that is, after the second hydrogen separation device 410 and the second oxygen separation device 420 further separate the hydrogen and oxygen in the alkali solution, the alkali solution is injected into the liquid storage device 30, so as to simplify the arrangement of the water electrolysis hydrogen production system 100.

[0069] In order to further improve the efficiency of gas-liquid separation, in some optional embodiments, each first gas-liquid separation device 2 is provided with a control switch, and the control switch is configured to control the start and stop of the first gas-liquid separation device 2.

[0070] By providing the first gas-liquid separation device 2 with a control switch, the first gas-liquid separation device 2 of the second electrolysis unit 10b can still be started alone when the second electrolysis unit 10b is in a non-working state, that is, the electrolytic cell array of the second electrolysis unit 10b is closed. While the circulating alkali solution flows through the second electrolysis unit 10b and is in a hot standby state, the first gas-liquid device of the second electrolysis unit 10b can separate the gas-liquid in the circulating alkali solution, thereby further improving the efficiency of gas-liquid separation and reducing the gas content in the alkali solution.

[0071] Considering that the performance parameters of the alkaline water electrolytic cells 1 in each electrolysis unit 10 are not completely the same due to the manufacturing precision deviation of the alkaline water electrolytic cells 1, the need for coordinated control of the electrolytic cell array on multiple alkaline water electrolytic cells, and the safety needs of the production device, by arranging the number of alkaline water electrolytic cells 1 in each electrolysis unit 10 to be less than or equal to four, the efficiency of gas-liquid separation of each electrolysis unit 10 can be ensured while realizing the heat exchange and energy saving of the electrolytic cell array, so as to be more suitable for large-scale wind power hydrogen production scenarios.

[0072] As an optional implementation, when the water electrolysis hydrogen production system 100 includes eight alkaline water electrolytic cells 1, four of the alkaline water electrolytic cells 1 can be arranged with a first gas-liquid separation device 2 to form a first electrolysis unit 10a, and the other four alkaline water electrolytic cells 1 can be arranged with another first gas-liquid separation device 2 to form a second electrolysis unit 10b, so as to meet the needs of heat exchange and energy saving and gas-liquid separation.

[0073] Based on this, the electrolytic water hydrogen production system 100 in the embodiment of the present application can balance and exchange heat among the multiple electrolytic units 10 through unified alkali circulation under the condition of power fluctuation, thereby improving energy utilization rate by utilizing the waste heat of alkali and enabling the electrolytic units 10 in a non-working state to achieve rapid response, so as to have the advantages of low energy loss, high energy utilization rate, stability and adaptability under power fluctuation, and easy popularization and application.

[0074] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to it without departing from the scope of the present application, and equivalent components thereof can be substituted. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A hydrogen production system by electrolysis of water, characterized by, The electrolytic system comprises a plurality of electrolytic units (10); The electrolytic unit (10) comprises an inlet end, an outlet end, an electrolytic cell array and a first gas-liquid separation device (2) arranged in series between the inlet end and the outlet end, the electrolytic cell array comprises a plurality of alkaline water electrolytic cells (1) arranged in parallel; the alkaline water electrolytic cell (1) is used for electrolyzing alkaline solution to generate a gas-liquid mixture, and the first gas-liquid separation device (2) is used for separating hydrogen and oxygen in the gas-liquid mixture and the alkaline solution, and discharging the alkaline solution from the outlet end; Among the plurality of electrolytic units (10), the outlet end of at least one electrolytic unit (10) is in communication with the inlet end of another electrolytic unit (10).

2. The hydrogen production system of claim 1, wherein The outlet ends of the plurality of electrolytic units (10) are in communication with each other, and the inlet ends of the plurality of electrolytic units (10) are in communication with each other; The electrolytic water hydrogen production system (100) further comprises a circulation pipeline, and the outlet end of each electrolytic unit (10) is connected to the inlet end of each electrolytic unit (10) through the circulation pipeline.

3. The hydrogen production system of claim 2, wherein The electrolytic water hydrogen production system comprises a first heat exchange unit (20), and the first heat exchange unit (20) is arranged in the circulation pipeline and used for adjusting the temperature of the alkaline solution in the circulation pipeline to a preset temperature.

4. The hydrogen production system of claim 3, wherein The first heat exchange unit (20) comprises a refrigeration module (210) and a heat exchange module (220). The first heat exchange unit (20) further comprises a temperature sensor and a control device, the temperature sensor is used for detecting the temperature of the alkaline solution in the circulation pipeline, and the control device is configured to control one of the refrigeration module (210) and the heat exchange module (220) to be turned on according to the temperature of the alkaline solution and the preset temperature.

5. The hydrogen production system of claim 2, wherein The electrolytic water hydrogen production system further comprises a liquid storage device (30), the liquid storage device (30) is arranged in the circulation pipeline, the alkaline solution of the outlet end of each electrolytic unit (10) flows into the liquid storage device (30), and the alkaline solution is connected to the inlet end of each electrolytic unit (10) through the liquid storage device (30).

6. The hydrogen production system of claim 5, wherein, The electrolytic water hydrogen production system further comprises a second heat exchange unit (50), the second heat exchange unit (50) is connected to the liquid storage device (30) and used for heat preservation or heating of the alkaline solution in the liquid storage device (30).

7. The hydrogen production system of claim 2, wherein The electrolytic water hydrogen production system further comprises a second gas-liquid separation device (40), the second gas-liquid separation device (40) is arranged in the circulation pipeline and used for gas-liquid separation of the alkaline solution in the circulation pipeline.

8. The hydrogen production system of claim 1, wherein, Each first gas-liquid separation device (2) is provided with a control switch, and the control switch is configured to control the start and stop of the first gas-liquid separation device (2).

9. The hydrogen production system of claim 1, wherein, Each alkaline water electrolytic cell (1) comprises a sub-inlet and a sub-outlet, the sub-inlet of each alkaline water electrolytic cell (1) is connected to the inlet end of the electrolytic unit (10), and the sub-outlet of each alkaline water electrolytic cell (1) is connected to the first gas-liquid separation device (2). The electrolytic cell array further comprises a plurality of first valves (3) and a plurality of second valves (4), each of the first valves (3) is matched to access a sub-inlet of the alkaline water electrolytic cell (1), and each of the second valves (4) is matched to access a sub-outlet of the alkaline water electrolytic cell (1).

10. The hydrogen production system of claim 9, wherein, The sub-outlet of the alkaline water electrolytic cell (1) comprises a hydrogen side outlet and an oxygen side outlet; The first gas-liquid separation device (2) comprises a first hydrogen separation device (21) and a first oxygen separation device (22), the first hydrogen separation device (21) is connected with the hydrogen side outlet and separates hydrogen and alkali liquor, the first oxygen separation device (22) is connected with the oxygen side outlet and separates oxygen and alkali liquor, and the alkali liquor separated by the first hydrogen separation device (21) and the first oxygen separation device (22) is discharged from an outlet end of the electrolytic unit (10).

Images