Hydrogen production system and hydrogen production station yard

Abstract

The invention discloses a hydrogen production system and a hydrogen production station yard, and belongs to the field of water electrolysis hydrogen production. The hydrogen production system comprises a first electrolytic cell, a corresponding first circulating pump, a second electrolytic cell, a corresponding second circulating pump, a liquid distributor, a gas-liquid separator and a heat exchanger, an outlet of the liquid distributor is connected with liquid inlets of the first electrolytic bath and the second electrolytic bath; gas-liquid outlets of the first electrolytic bath and the second electrolytic bath are connected with an inlet of the gas-liquid separator; an inlet of a first path of the heat exchanger is connected with a liquid phase outlet of the gas-liquid separator; wherein an inlet of the first circulating pump is connected with an outlet of the first path of the heat exchanger, and an outlet of the first circulating pump is connected with a liquid inlet of the first electrolytic cell and an inlet of the liquid distributor. The time from starting to entering the normal working state of the to-be-started second electrolytic cell can be shortened, meanwhile, redundant heat of the started first electrolytic cell is recycled, and energy waste is reduced.

Description

Technical Field

[0001] This application belongs to the field of hydrogen production by water electrolysis, and particularly relates to a hydrogen production system and a hydrogen production station. Background Technology

[0002] Currently, with the development of the industry, hydrogen production systems are gradually becoming larger in scale. In such large-scale projects, the typical configuration of the hydrogen production system involves multiple electrolyzers connected in parallel to a gas-liquid separator, with one or more gas-liquid separators corresponding to a liquid distributor. At present, the electrical energy used by electrolyzers comes from fluctuating energy sources such as wind and solar power, and multiple electrolyzers are generally not operated simultaneously.

[0003] In related technologies, when the electrical energy of the hydrogen production system can meet the needs of more electrolyzers, the liquid in the later-started electrolyzers needs to be heated from room temperature to a suitable operating temperature before it can work normally. This results in a longer start-up time and higher energy consumption, which requires improvement. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a hydrogen production system and hydrogen production station that can shorten the time from startup to normal operation of the second electrolyzer to be started, while recovering and utilizing the excess heat of the already started first electrolyzer, thereby reducing energy waste.

[0005] In a first aspect, this application provides a hydrogen production system, comprising:

[0006] The first electrolytic cell and the corresponding first circulating pump;

[0007] The second electrolytic cell and the corresponding second circulating pump;

[0008] A liquid mixer, the outlet of which is connected to the inlet of the first electrolytic cell and the second electrolytic cell;

[0009] A gas-liquid separator, wherein the gas-liquid outlets of the first electrolytic cell and the second electrolytic cell are connected to the inlet of the gas-liquid separator;

[0010] A heat exchanger, wherein the inlet of the first path of the heat exchanger is connected to the liquid phase outlet of the gas-liquid separator; wherein,

[0011] The inlet of the first circulating pump is connected to the outlet of the first path of the heat exchanger, and the outlet of the first circulating pump is connected to the inlet of the first electrolytic cell and the inlet of the liquid distributor; the inlet of the second circulating pump is connected to the inlet of the second electrolytic cell, and the outlet of the second circulating pump is connected to the inlet of the first path of the heat exchanger.

[0012] According to the hydrogen production system of this application, by connecting the inlet of the second circulating pump to the liquid inlet of the second electrolyzer, the outlet of the second circulating pump to the inlet of the first path of the heat exchanger, and the outlet of the liquid distributor to the liquid inlets of the first and second electrolyzers, the inlet of the first circulating pump to the outlet of the first path of the heat exchanger, and the outlet of the first circulating pump to the liquid inlet of the first electrolyzer and the inlet of the liquid distributor, the high-temperature liquid of the first electrolyzer during operation and the room-temperature liquid of the second electrolyzer before startup can be combined in the heat exchanger. The mixed liquid flows back to the first electrolyzer to continue participating in electrolysis, while another part of the mixed liquid flows to the liquid distributor and then flows into the second electrolyzer. This achieves the replacement of the room-temperature liquid in the second electrolyzer with the high-temperature liquid, which can shorten the time for the second electrolyzer to heat from room-temperature liquid to high-temperature liquid, that is, shorten the time for the second electrolyzer to enter normal working state from startup. At the same time, the excess heat of the first electrolyzer is recovered and utilized, reducing energy waste.

[0013] According to one embodiment of this application, the first electrolytic cell is an electrolytic cell that has already been started, and the second electrolytic cell is an electrolytic cell that is to be started.

[0014] According to one embodiment of this application, the hydrogen production system further includes:

[0015] The controller is equipped with a flow regulating valve between the outlet of the first circulating pump and the inlet of the liquid dispenser, and a flow meter between the outlet of the first circulating pump and the inlet of the first electrolytic cell. The controller is electrically connected to the flow meter and the flow regulating valve and is configured to control the flow regulating valve based on the signal from the flow meter. The flow meter is used to obtain the working flow rate Q1 of the first electrolytic cell.

[0016] According to one embodiment of this application, the hydrogen production system further includes:

[0017] The first temperature sensor is used to obtain the liquid inlet temperature T1 of the first electrolytic cell;

[0018] The second temperature sensor is used to obtain the outlet temperature T2 of the first electrolytic cell;

[0019] The third temperature sensor is used to obtain the liquid temperature T3 of the second electrolytic cell;

[0020] The controller is electrically connected to the first temperature sensor, the second temperature sensor, and the third temperature sensor, and is configured to switch the operating states of the second electrolytic cell and the second circulating pump based on the signals from the first temperature sensor, the second temperature sensor, the third temperature sensor, and the flow meter.

[0021] According to one embodiment of this application, the hydrogen production system further includes:

[0022] A nitrogen source is provided, which is connected to the gas-liquid outlets of the first electrolytic cell and the second electrolytic cell, respectively.

[0023] According to one embodiment of this application, the gas phase outlet of the gas-liquid separator is connected to the gas-liquid outlets of the first electrolytic cell and the second electrolytic cell, respectively.

[0024] According to one embodiment of this application, the inlet of the first circulating pump is connected to one of the outlet of the first path of the heat exchanger and the liquid inlet of the first electrolytic cell; the outlet of the first circulating pump is connected to the liquid inlet of the first electrolytic cell and the inlet of the liquid distributor or to the inlet of the first path of the heat exchanger.

[0025] The inlet of the second circulating pump is connected to one of the outlet of the first path of the heat exchanger and the inlet of the second electrolytic cell; the outlet of the second circulating pump is connected to the inlet of the second electrolytic cell and the inlet of the liquid distributor or to the inlet of the first path of the heat exchanger.

[0026] According to one embodiment of this application, when the first electrolytic cell and the second electrolytic cell are alkaline electrolytic cells, the liquid dispenser is an alkali dispenser; or, when the first electrolytic cell and the second electrolytic cell are PEM electrolytic cells, the liquid dispenser is a pure water dispenser.

[0027] According to one embodiment of this application, the gas-liquid separator includes:

[0028] The hydrogen separator has its inlet connected to the gas-liquid outlets on the hydrogen side of the first electrolytic cell and the second electrolytic cell, respectively, and its liquid phase outlet connected to the inlet of the first path of the heat exchanger.

[0029] An oxygen separator is provided, wherein the inlet of the oxygen separator is connected to the gas-liquid outlets on the oxygen side of the first electrolytic cell and the second electrolytic cell, respectively, and the liquid outlet of the oxygen separator is connected to the inlet of the first path of the heat exchanger.

[0030] Secondly, this application provides a hydrogen production system, which includes: a first electrolyzer and a corresponding first circulation pump;

[0031] The second electrolytic cell and the corresponding second circulating pump;

[0032] A liquid mixer, the outlet of which is connected to the inlet of the first electrolytic cell and the second electrolytic cell;

[0033] A gas-liquid separator, wherein the gas-liquid outlets of the first electrolytic cell and the second electrolytic cell are connected to the inlet of the gas-liquid separator;

[0034] A heat exchanger, wherein the inlet of the first path of the heat exchanger is connected to the liquid phase outlet of the gas-liquid separator;

[0035] A first control valve is provided between the inlet of the first circulating pump and the outlet of the first path of the heat exchanger; a second control valve is provided between the inlet of the first circulating pump and the liquid inlet of the first electrolytic cell; a third control valve is provided between the outlet of the first circulating pump and the liquid inlet of the first electrolytic cell; a flow regulating valve is provided between the outlet of the first circulating pump and the inlet of the liquid distributor; and a fourth control valve is provided between the outlet of the first circulating pump and the inlet of the first path of the heat exchanger. A fifth control valve is provided between the inlet of the second circulating pump and the outlet of the first path of the heat exchanger; a sixth control valve is provided between the inlet of the second circulating pump and the liquid inlet of the second electrolytic cell; a seventh control valve is provided between the outlet of the second circulating pump and the liquid inlet of the second electrolytic cell; and an eighth control valve is provided between the outlet of the second circulating pump and the inlet of the first path of the heat exchanger.

[0036] According to the hydrogen production system of this application, by connecting the inlet of the second circulating pump to the liquid inlet of the second electrolyzer, the outlet of the second circulating pump to the inlet of the first path of the heat exchanger, and the outlet of the liquid distributor to the liquid inlets of the first and second electrolyzers, the inlet of the first circulating pump to the outlet of the first path of the heat exchanger, and the outlet of the first circulating pump to the liquid inlet of the first electrolyzer and the inlet of the liquid distributor, the high-temperature liquid of the first electrolyzer during operation and the room-temperature liquid of the second electrolyzer before startup can be combined in the heat exchanger. The mixed liquid flows back to the first electrolyzer to continue participating in electrolysis, while another part of the mixed liquid flows to the liquid distributor and then flows into the second electrolyzer. This achieves the replacement of the room-temperature liquid in the second electrolyzer with the high-temperature liquid, which can shorten the time for the second electrolyzer to heat from room-temperature liquid to high-temperature liquid, that is, shorten the time for the second electrolyzer to enter normal working state from startup. At the same time, the excess heat of the first electrolyzer is recovered and utilized, reducing energy waste.

[0037] Thirdly, this application provides a hydrogen production station, which includes the hydrogen production system described in any of the above claims.

[0038] According to the hydrogen production station of this application, a hydrogen production system is installed. The inlet of the second circulation pump of the hydrogen production system is connected to the liquid inlet of the second electrolyzer, the outlet of the second circulation pump is connected to the inlet of the first path of the heat exchanger, the outlet of the liquid distributor is connected to the liquid inlets of the first and second electrolyzers, the inlet of the first circulation pump is connected to the outlet of the first path of the heat exchanger, and the outlet of the first circulation pump is connected to the liquid inlet of the first electrolyzer and the inlet of the liquid distributor. This allows the high-temperature liquid from the first electrolyzer during operation to be combined with the room-temperature liquid from the second electrolyzer before startup within the heat exchanger. The mixed liquid flows back to the first electrolyzer to continue electrolysis, while another portion of the mixed liquid flows to the liquid distributor and then into the second electrolyzer. This achieves the replacement of the room-temperature liquid in the second electrolyzer with the high-temperature liquid, shortening the time for the second electrolyzer to heat from room-temperature to high-temperature liquid, thus shortening the time from startup to normal operation. At the same time, excess heat from the first electrolyzer is recovered and utilized, reducing energy waste.

[0039] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0040] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0041] Figure 1 This is a schematic diagram of the structure of a hydrogen production system based on related technologies;

[0042] Figure 2 This is one of the structural schematic diagrams of the hydrogen production system provided in the embodiments of this application;

[0043] Figure 3 This is the second schematic diagram of the hydrogen production system provided in the embodiments of this application.

[0044] Figure label:

[0045] 1. First electrolytic cell 1; 2. First circulating pump 2; 3. Second electrolytic cell 3; 4. Second circulating pump 4; 5. Liquid mixer 5; 61. Hydrogen separator 6; 62. Oxygen separator 6; 7. Heat exchanger 7; 8. Flow regulating valve 8; 9. Flow meter 9; 10. Second hydrogen pressure gauge 10; 11. Second oxygen pressure gauge 11; 12. First control valve 12; 13. Second control valve 14; 15. Fourth control valve 15; 16. Fifth control valve 16; 17. Sixth control valve 17; 18. Seventh control valve 18; 19. Eighth control valve 19; 20. Ninth control valve 20; 21. Tenth control valve 21; 22. Eleventh control valve 22; 12th control valve 23; 24. Second hydrogen side control valve 25; 25. Second oxygen side control valve 26; 27. Third vent valve 26; Fourth vent valve 27; Alkali mixing pump 28; 29. ​​First nitrogen replenishment flow meter 20; 30. Second nitrogen replenishment flow meter 31. Detailed Implementation

[0046] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0047] like Figure 1 As shown, taking a hydrogen production system comprising three electrolyzers as an example, the three electrolyzers are connected in parallel. The leftmost electrolyzer is the first electrolyzer 1, which is already running, and the other two are the second electrolyzers 3, which are waiting to be started. The current startup process for the second electrolyzer 3 is as follows: after the hydrogen production system's electrical energy meets the requirements, the valves on the electrolyte circulation pipeline and the gas-liquid outlet pipeline of the second electrolyzer 3 are opened. Then, the corresponding circulation pump for the second electrolyzer 3 is started, followed by the start of the corresponding second electrolyzer 3. Because the electrolyte temperature in the newly started second electrolyzer 3 is low, the circulation pump can only operate at low power initially, not at full power. This process takes about 30 minutes to bring the newly started second electrolyzer 3 to full power operation, prolonging the startup time of the second electrolyzer 3 that starts later. Furthermore, all the heat generated by the first electrolyzer 1 in the early stages is carried away by the circulating water, resulting in heat waste.

[0048] In order to solve Figure 1 In a hydrogen production system with multiple electrolyzers operating in parallel, the start-up times of the electrolyzers differ. The later-starting electrolyzers suffer from longer start-up times, while the earlier-starting electrolyzers waste heat. This application provides an embodiment as follows: Figure 2 and Figure 3 The hydrogen production system shown.

[0049] like Figure 2 and Figure 3 As shown, the hydrogen production system of this application embodiment includes: a first electrolyzer 1 and a corresponding first circulating pump 2, a second electrolyzer 3 and a corresponding second circulating pump 4, a liquid distributor 5, a gas-liquid separator, and a heat exchanger 7; the outlet of the liquid distributor 5 is connected to the liquid inlet of the first electrolyzer 1 and the second electrolyzer 3; the gas-liquid outlet of the first electrolyzer 1 and the second electrolyzer 3 is connected to the inlet of the gas-liquid separator; the inlet of the first path of the heat exchanger 7 is connected to the liquid phase outlet of the gas-liquid separator; wherein, the inlet of the first circulating pump 2 is connected to the first path outlet of the heat exchanger 7, and the outlet of the first circulating pump 2 is connected to the liquid inlet of the first electrolyzer 1 and the inlet of the liquid distributor 5; the inlet of the second circulating pump 4 is connected to the liquid inlet of the second electrolyzer 3, and the outlet of the second circulating pump 4 is connected to the first path inlet of the heat exchanger 7.

[0050] In this embodiment, the hydrogen production system includes multiple electrolyzers connected in parallel, one or more of which are first electrolyzers 1, and one or more of which are second electrolyzers 3.

[0051] The electrolytic cell can be an alkaline electrolytic cell or a PEM electrolytic cell. When the electrolytic cell is an alkaline electrolytic cell, the liquid dispenser 5 can provide alkaline solution; when the electrolytic cell is a PEM electrolytic cell, the liquid dispenser 5 can provide pure water.

[0052] The second channel of the heat exchanger 7 can be used for heat exchange medium. The high-temperature liquid from the first electrolytic cell 1 during operation and the room-temperature liquid from the second electrolytic cell 3 can merge in the first channel of the heat exchanger 7. The temperature of the low-temperature liquid rises, preheating the room-temperature liquid in the second electrolytic cell 3, thereby recovering the waste heat from the first electrolytic cell 1.

[0053] A portion of the mixed liquid flowing out of the first outlet of heat exchanger 7 flows back to the first electrolytic cell 1 to continue participating in electrolysis, while the other portion flows to the liquid distributor 5 and then into the second electrolytic cell 3. This achieves the replacement of the room-temperature liquid in the second electrolytic cell 3 with the liquid that has been heated after mixing. This shortens the time it takes for the second electrolytic cell 3 to heat the liquid from room temperature to high temperature, thus shortening the time it takes for the second electrolytic cell 3 to go from startup to normal operation. At the same time, it recovers and utilizes the excess heat of the first electrolytic cell 1, reducing energy waste.

[0054] The first electrolytic cell 1 and the second electrolytic cell 3 are connected in parallel. The first electrolytic cell 1 can be an electrolytic cell that has been started or an electrolytic cell that has stopped working but whose liquid temperature is still higher than normal. There can be one or more first electrolytic cells 1. The first circulation pump 2 is the circulation pump corresponding to the first electrolytic cell 1. The first circulation pump 2 can be used to extract or discharge the mixed liquid in the heat exchanger 7. A portion of the mixed liquid is transported to the corresponding first electrolytic cell 1, and the excess mixed liquid is transported to the liquid distributor 5 for storage.

[0055] The second electrolytic cell 3 can be an electrolytic cell to be started or an electrolytic cell in which the liquid temperature has not reached the working temperature. There can be one or more second electrolytic cells 3. The second circulation pump 4 is the circulation pump corresponding to the second electrolytic cell 3. The second circulation pump 4 can draw the room temperature liquid in the second electrolytic cell 3 from the liquid inlet of the second electrolytic cell 3 and discharge it into the heat exchanger 7. The room temperature liquid of the second circulation pump 4 mixes with the high temperature liquid of the first electrolytic cell 1 in the heat exchanger 7.

[0056] The liquid distributor 5 is used to store the liquid mixed in the heat exchanger 7 between the first electrolytic cell 1 and the second electrolytic cell 3. The liquid temperature in the liquid distributor 5 should be higher than the ambient temperature so that after the liquid distributor 5 delivers the liquid to the second electrolytic cell 3, the liquid temperature in the second electrolytic cell 3 is higher than the ambient temperature, thereby making the liquid temperature in the second electrolytic cell 3 closer to the normal operating temperature of the second electrolytic cell 3, which can shorten the time from start-up to normal operation of the second electrolytic cell 3.

[0057] It should be noted that, since the high-temperature liquid from the first electrolytic cell 1 is transported to the gas-liquid separator and the room-temperature liquid from the second electrolytic cell 3 is mixed in the first path of the heat exchanger 7, the volume of the mixed liquid output from the heat exchanger 7 is greater than the volume of the first electrolytic cell 1. The mixed liquid exceeding the volume of the first electrolytic cell 1 can be transported to the distributor 5 for storage. Compared to directly transporting the mixed liquid to the second electrolytic cell 3 to mix it again with the room-temperature liquid that has not been extracted, sending the mixed high-temperature liquid to the distributor 5 first can separate the unheated liquid and the heated liquid in the second electrolytic cell 3. When the liquid in the second electrolytic cell 3 is extracted to a certain volume or for a certain period of time, the high-temperature mixed liquid in the alkali tank is transported back to the second electrolytic cell 3. The heated liquid will not be cooled down, and the temperature in the second electrolytic cell 3 can be maintained at a high temperature. It is also easier to control the volume of the liquid being replaced in the second electrolytic cell 3.

[0058] The gas-liquid separator is connected to the gas-liquid outlet of the first electrolytic cell 1 and the gas-liquid outlet of the second electrolytic cell 3, respectively, to separate the gas and liquid generated by the first electrolytic cell 1 and the second electrolytic cell 3.

[0059] The gas-liquid separator includes a hydrogen separator 61 and an oxygen separator 62. The hydrogen separator 61 is connected to the hydrogen gas-liquid outlets of the first electrolytic cell 1 and the second electrolytic cell 3, respectively. The oxygen separator 62 is connected to the oxygen gas-liquid outlets of the first electrolytic cell 1 and the second electrolytic cell 3, respectively.

[0060] The gas-liquid separator includes an inlet, a gas phase outlet, and a liquid phase outlet; the hydrogen inlet of the hydrogen separator 61 is connected to the gas-liquid outlets on the hydrogen side of the first electrolytic cell 1 and the second electrolytic cell 3, respectively; the oxygen inlet of the oxygen separator 62 is connected to the gas-liquid outlets on the oxygen side of the first electrolytic cell 1 and the second electrolytic cell 3, respectively; and the liquid phase outlets of the hydrogen separator 61 and the oxygen separator 62 are connected to the inlet of the first path of the heat exchanger 7.

[0061] The inlet of the first path of the heat exchanger 7 is connected to the liquid outlet of the gas-liquid separator to collect and exchange the high-temperature liquid separated by the gas-liquid separator, and then discharge it into the first electrolytic cell 1 and the liquid distributor 5; the inlet of the first path of the heat exchanger 7 is also connected to the second electrolytic cell 3, and the liquid in the second electrolytic cell 3 can flow into the first path of the heat exchanger 7 and mix with the high-temperature liquid.

[0062] According to the hydrogen production system provided in the embodiments of this application, by connecting the inlet of the second circulating pump 4 to the liquid inlet of the second electrolyzer 3, the outlet of the second circulating pump 4 to the inlet of the first path of the heat exchanger 7, the outlet of the liquid distributor 5 to the liquid inlets of the first electrolyzer 1 and the second electrolyzer 3, the inlet of the first circulating pump 2 to the outlet of the first path of the heat exchanger 7, and the outlet of the first circulating pump 2 to the liquid inlet of the first electrolyzer 1 and the inlet of the liquid distributor 5, it is possible to achieve the mixing of the high-temperature liquid from the first electrolyzer 1 during operation with the liquid inlet of the second electrolyzer 3 within the heat exchanger 7. When the two electrolytic cells 3 are about to start up, the room-temperature liquids merge together. The mixed liquid flows back to the first electrolytic cell 1 to continue participating in electrolysis. Another part of the mixed liquid flows to the liquid distributor 5, and then flows into the second electrolytic cell 3 through the liquid distributor 5. This realizes the replacement of the room-temperature liquid in the second electrolytic cell 3 with high-temperature liquid, which can shorten the time for the second electrolytic cell 3 to heat from room-temperature liquid to high-temperature liquid, that is, shorten the time for the second electrolytic cell 3 to enter the normal working state from start-up. At the same time, the excess heat of the first electrolytic cell 1 is recovered and utilized, reducing energy waste.

[0063] In some embodiments, when the first electrolytic cell 1 and the second electrolytic cell 3 are alkaline electrolytic cells, the liquid distributor 5 is an alkali distributor, for example, an alkali solution preparation tank.

[0064] In some embodiments, when the first electrolytic cell 1 and the second electrolytic cell 3 are PEM electrolytic cells, the liquid dispenser 5 is a pure water device, for example, a pure water tank.

[0065] In the case where the first electrolytic cell 1 and the second electrolytic cell 3 are alkaline electrolytic cells, the alkali preparation device can provide alkaline solution to the first electrolytic cell 1 and the second electrolytic cell 3; in the case where the first electrolytic cell 1 and the second electrolytic cell 3 are PEM electrolytic cells, the water purifier can provide pure water to the first electrolytic cell 1 and the second electrolytic cell 3.

[0066] In some embodiments, the first electrolytic cell 1 is an electrolytic cell that has already been started, and the second electrolytic cell 3 is an electrolytic cell that is to be started.

[0067] It should be noted that the normal operating temperature of an electrolytic cell is around 70℃, while the liquid temperature inside an unused electrolytic cell is at room temperature.

[0068] The normal operating temperature of the liquid in the first electrolytic cell 1 is around 70℃, while the liquid in the second electrolytic cell 3 is at room temperature. The high-temperature liquid from the first electrolytic cell 1, which has already been started, flows into the first channel of the heat exchanger 7 through the gas-liquid separator. The room-temperature liquid from the second electrolytic cell 3, which is about to be started, flows into the first channel of the heat exchanger 7 from the return port of the electrolytic cell. The high-temperature liquid and the room-temperature liquid mix in the first channel of the heat exchanger 7, which can heat the room-temperature liquid.

[0069] It should be noted that the structure and connection relationship of the first electrolytic cell 1 and the second electrolytic cell 3 can be the same or different.

[0070] When the first electrolytic cell 1 and the second electrolytic cell 3 have the same structure and connection relationship, they can be the same electrolytic cell or different electrolytic cells at different times. For example, the same electrolytic cell can be the first electrolytic cell 1 in the start-up state and the second electrolytic cell 3 in the waiting-to-start state.

[0071] When the structures and connections of the first electrolytic cell 1 and the second electrolytic cell 3 are different, the first electrolytic cell 1 and the second electrolytic cell 3 can be different electrolytic cells. The first electrolytic cell 1 is a normally open specific electrolytic cell, and the second electrolytic cell 3 is an intermittently started electrolytic cell.

[0072] In some embodiments, the hydrogen production system further includes: a controller; a flow regulating valve 8 is provided between the outlet of the first circulating pump 2 and the inlet of the liquid distributor 5; a flow meter 9 is provided between the outlet of the first circulating pump 2 and the inlet of the first electrolyzer 1; the controller is electrically connected to the flow meter 9 and the flow regulating valve 8; the controller is configured to control the flow regulating valve 8 based on the signal from the flow meter 9; the flow meter 9 is used to obtain the working flow rate Q1 of the first electrolyzer 1.

[0073] The flow meter 9 is used to detect the flow rate into the inlet of the first electrolytic cell 1. The controller controls the flow regulating valve 8 based on the signal from the flow meter 9, thereby controlling the flow rate of the liquid flowing into the first electrolytic cell 1 so that the flow rate of the liquid flowing into the first electrolytic cell 1 meets the normal working requirements, reduces the situation of liquid overflow due to excessive flow, and improves the reliability and safety of the hydrogen production system.

[0074] For example, the normal operating flow rate of the first electrolytic cell 1 is Q1, and the first circulating pump 2 operates at a flow rate of Q1. The controller ensures that the liquid flow rate into the first electrolytic cell 1 is Q1 based on the interlocking of the flow regulating valve 8 and the flow meter 9. Any excess liquid exceeding Q1 flows to the alkali mixing tank for storage.

[0075] Where Q1 can be 65m 3 / h, 70m 3 / h or other flow rates, which can be determined according to the type and working conditions of the first electrolytic cell 1.

[0076] In some embodiments, the hydrogen production system further includes: a first temperature sensor, a second temperature sensor, and a third temperature sensor; the first temperature sensor is used to acquire the inlet temperature T1 of the first electrolyzer 1; the second temperature sensor is used to acquire the outlet temperature T2 of the first electrolyzer 1; the third temperature sensor is used to acquire the liquid temperature T3°C of the second electrolyzer 3; the controller is electrically connected to the first temperature sensor, the second temperature sensor, and the third temperature sensor, and the controller is configured to switch the operating states of the second electrolyzer 3 and the second circulating pump 4 based on the signals from the first temperature sensor, the second temperature sensor, the third temperature sensor, and the flow meter 9.

[0077] In this embodiment, a first temperature sensor is installed near the liquid inlet of the first electrolytic cell 1. For example, the first temperature sensor can be installed at the liquid inlet of the first electrolytic cell 1, outside the liquid inlet of the first electrolytic cell 1, or inside the liquid inlet of the first electrolytic cell 1. A second temperature sensor is installed near the gas-liquid outlet of the first electrolytic cell 1. For example, the second temperature sensor can be installed at the gas-liquid outlet of the first electrolytic cell 1, outside the gas-liquid outlet of the first electrolytic cell 1, or inside the gas-liquid outlet of the first electrolytic cell 1. Based on the first and second temperature sensors, the controller can obtain the temperature difference between the inlet and outlet of the first electrolytic cell 1.

[0078] The third temperature sensor can be installed inside the second electrolytic cell 3 to obtain the liquid temperature of the liquid inside the second electrolytic cell 3.

[0079] It should be noted that when the first electrolytic cell 1 and the second electrolytic cell 3 are the same electrolytic cell, the first temperature sensor, the second temperature sensor, and the third temperature sensor are all located on the same electrolytic cell; when the first electrolytic cell 1 and the second electrolytic cell 3 are different electrolytic cells, the first electrolytic cell 1 is a normally open electrolytic cell, the second electrolytic cell 3 is an intermittently started electrolytic cell, the first temperature sensor and the second temperature sensor are located on the first electrolytic cell 1, and the third temperature sensor is installed on the second electrolytic cell 3.

[0080] The controller is configured to switch the operating states of the second electrolytic cell 3 and the second circulation pump 4 after the second circulation pump 4 draws liquid from the second electrolytic cell 3 for a first time t1, where t1 satisfies:

[0081]

[0082] Where T0 is the target temperature of the liquid in the second electrolytic cell 3; T2-T1 is the temperature difference between the inlet and outlet liquids of the first electrolytic cell 1; T3 is the liquid temperature inside the second electrolytic cell 3; and V2 is the volume of the second electrolytic cell 3, in cubic meters per second (m³). 3 Q1 is the operating flow rate of the first electrolytic cell 1, in m³ / s. 3 / h; t1 is the first time that the second circulating pump 4 draws liquid from the second electrolytic cell 3, in minutes.

[0083] In this embodiment, the controller switches the operating states of the second electrolytic cell 3 and the second circulation pump 4 based on the first time t1 when the second circulation pump 4 extracts liquid from the second electrolytic cell 3. After the first time t1, the volume of liquid extracted by the second circulation pump 4 from the second electrolytic cell 3 has reached the target replacement ratio of the liquid in the second electrolytic cell 3. The target replacement ratio can be 90%, 80%, or other ratios. The temperature of the mixed liquid in the heat exchanger 7 reaches the predetermined temperature, and the extraction of liquid from the second electrolytic cell 3 can be stopped. The mixed liquid in the liquid distributor 5 is then introduced into the second electrolytic cell 3 to complete the replacement of the room temperature liquid and the mixed liquid in the second electrolytic cell 3.

[0084] For example, the target temperature of the liquid in the second electrolyzer 3 can be close to the temperature at which the electrolyzer operates at full power. The target temperature is determined based on the working scenario of the hydrogen production system, the type of the second electrolyzer 3, and the type of liquid. For instance, the target temperature T0 of the liquid in the second electrolyzer 3 can be 70°C. The target temperature of the liquid in the second electrolyzer 3 can be 50°C, 55°C, or 65°C. Compared to the start-up process of the liquid in the second electrolyzer 3 rising from room temperature to the full power operating temperature of 70°C, rising from the target temperature of 55°C or 65°C to the full power operating temperature of 70°C can shorten the heating time, shorten the start-up time of the second electrolyzer 3, and also utilize the waste heat of the first electrolyzer 1, reducing energy consumption.

[0085] The volume of the second electrolyzer 3 can be set according to the working scenario of the hydrogen production system. For example, the volume of the second electrolyzer 3 can be 10m³. 3 15m 3 Or other volumes. After the first time t1, the second circulation pump 4 has drawn liquid from the second electrolytic cell 3 to the target replacement ratio of the liquid in the second electrolytic cell 3, which can be 90%, 80% or other ratios.

[0086] For example, the volume of the second electrolytic cell 3 can be 10m³. 3 In this case, the 9m of the second electrolytic cell 3 can be used. 3 The liquid is replaced.

[0087] The liquid temperature T3 in the second electrolytic cell 3 is related to the working state of the second electrolytic cell 3. When the second electrolytic cell 3 is not started, the liquid temperature T3 in the second electrolytic cell 3 can be at room temperature. After the second electrolytic cell 3 is started, the liquid temperature T3 in the second electrolytic cell 3 gradually rises to the target temperature for full power operation.

[0088] The operating flow rate Q1 of the first electrolytic cell 1 can be 70 m³ / s. 3 / h、80m 3 / h or 90m 3 / h, which can be determined based on factors such as the volume, working status and working scenario of the first electrolytic cell 1.

[0089] In some embodiments, in order for the second circulation pump 4 to successfully extract liquid from the sealed second electrolytic cell 3, it is necessary to first replenish the second electrolytic cell 3 with gas. The gas replenishment device includes at least the following two structures:

[0090] Firstly, such as Figure 3 As shown, the hydrogen production system also includes a nitrogen source, which is connected to the gas and liquid outlets of the first electrolyzer 1 and the second electrolyzer 3, respectively.

[0091] In this embodiment, before the second circulation pump 4 draws liquid from the second electrolytic cell 3, the nitrogen source is started and connected to the gas-liquid outlets of the first electrolytic cell 1 and the second electrolytic cell 3 respectively. The nitrogen source replenishes nitrogen into the second electrolytic cell 3 through the gas-liquid outlet of the second electrolytic cell 3 and pressurizes the second electrolytic cell 3. When the hydrogen pressure gauge and oxygen pressure gauge of the second electrolytic cell 3 reach the preset pressure value, the nitrogen source is turned off.

[0092] When the second electrolytic cell 3 is under positive pressure, the second circulation pump 4 is started to draw the liquid in the second electrolytic cell 3 to the first channel of the heat exchanger 7, which can make the second circulation pump 4 draw liquid smoothly and improve safety.

[0093] The preset pressure values ​​of the hydrogen pressure gauge and oxygen pressure gauge of the second electrolytic cell 3 can be 1MPa to 3MPa, for example, the preset pressure values ​​can be 1.5MPa, 1.8MPa or 2MPa.

[0094] Secondly, such as Figure 2 As shown, the outlet of the gas-liquid separator is connected to the gas-liquid outlet of the first electrolytic cell 1 and the second electrolytic cell 3, respectively.

[0095] In this embodiment, before the second circulation pump 4 draws liquid from the second electrolytic cell 3, the gas-liquid separator is connected to the second electrolytic cell 3. The gas that has been separated in the gas-liquid separator flows into the gas-liquid separator. The second hydrogen pressure gauge 10 and the second oxygen pressure gauge 11 of the second electrolytic cell 3 are observed. When the pressure of the second hydrogen pressure gauge 10 and the second oxygen pressure gauge 11 is balanced with the system pressure of the gas-liquid separator, the connection between the gas-liquid separator and the gas-liquid outlet of the first electrolytic cell 1 and the second electrolytic cell 3 is disconnected, and the second circulation pump 4 is started. This allows the second circulation pump 4 to draw liquid smoothly. The structure is simple and the cost is low.

[0096] In some embodiments, the inlet of the first circulating pump 2 is connected to one of the outlet of the first path of the heat exchanger 7 and the inlet of the first electrolytic cell 1; the outlet of the first circulating pump 2 is connected to the inlet of the first electrolytic cell 1 and the inlet of the liquid distributor 5 or to the inlet of the first path of the heat exchanger 7; the inlet of the second circulating pump 4 is connected to one of the outlet of the first path of the heat exchanger 7 and the inlet of the second electrolytic cell 3; the outlet of the second circulating pump 4 is connected to the inlet of the second electrolytic cell 3 and the inlet of the liquid distributor 5 or to the inlet of the first path of the heat exchanger 7.

[0097] In this embodiment, the first circulating pump 2 and the second circulating pump 4 have the same structure and connection relationship. That is, the connection structure between the first electrolyzer 1 and the first circulating pump 2, and the connection structure between the second electrolyzer 3 and the second circulating pump 4 are the same. In other words, in the multiple parallel electrolyzers of the hydrogen production system, any one of the electrolyzers can be the first electrolyzer 1, and any one of the electrolyzers can be the second electrolyzer 3. The hydrogen production system can replace and preheat the liquid inside any electrolyzer to be started, and can recover and utilize the residual heat of the liquid in any electrolyzer that has been started.

[0098] This application embodiment also provides a hydrogen production system, including: a first electrolyzer 1 and a corresponding first circulating pump 2, a second electrolyzer 3 and a corresponding second circulating pump 4, a liquid distributor 5, a gas-liquid separator, and a heat exchanger 7; the outlet of the liquid distributor 5 is connected to the liquid inlet of the first electrolyzer 1 and the second electrolyzer 3; the gas-liquid outlet of the first electrolyzer 1 and the second electrolyzer 3 is connected to the inlet of the gas-liquid separator; the inlet of the first path of the heat exchanger 7 is connected to the liquid phase outlet of the gas-liquid separator.

[0099] Specifically, a first control valve 12 is installed between the inlet of the first circulating pump 2 and the first outlet of the heat exchanger 7; a second control valve 13 is installed between the inlet of the first circulating pump 2 and the liquid inlet of the first electrolytic cell 1; a third control valve 14 is installed between the outlet of the first circulating pump 2 and the liquid inlet of the first electrolytic cell 1; a flow regulating valve 8 is installed between the outlet of the first circulating pump 2 and the inlet of the liquid distributor 5; and a fourth control valve 15 is installed between the outlet of the first circulating pump 2 and the first inlet of the heat exchanger 7. A fifth control valve 16 is installed between the inlet of the second circulating pump 4 and the first outlet of the heat exchanger 7; a sixth control valve 17 is installed between the inlet of the second circulating pump 4 and the liquid inlet of the second electrolytic cell 3; a seventh control valve 18 is installed between the outlet of the second circulating pump 4 and the liquid inlet of the second electrolytic cell 3; and an eighth control valve 19 is installed between the outlet of the second circulating pump 4 and the first inlet of the heat exchanger 7.

[0100] In this embodiment, the controller selectively connects the inlet of the first circulating pump 2 to one of the outlet of the first path of the heat exchanger 7 and the inlet of the first electrolytic cell 1 by controlling the first control valve 12 and the second control valve 13; the controller selectively connects the outlet of the first circulating pump 2 to the inlet of the first electrolytic cell 1 and the inlet of the liquid distributor 5 by controlling the third control valve 14 and the fourth control valve 15; and the controller controls the outlet of the first circulating pump 2 to connect to the inlet of the first path of the heat exchanger 7 by controlling the flow regulating valve 8.

[0101] The controller selectively connects the inlet of the second circulating pump 4 to one of the outlet of the first path of the heat exchanger 7 and the inlet of the second electrolytic cell 3 by controlling the fifth control valve 16 and the sixth control valve 17; the controller selectively connects the outlet of the second circulating pump 4 to the inlet of the second electrolytic cell 3 and the inlet of the first path of the heat exchanger 7 by controlling the seventh control valve 18 and the eighth control valve 19.

[0102] The hydrogen production system of this application embodiment will be specifically described below from the perspective of two different start-up methods.

[0103] Firstly, such as Figure 2 As shown, taking a hydrogen production system with three electrolyzers connected in parallel to a gas-liquid separation unit as an example, the first electrolyzer 1 is running, and the second electrolyzer 3, which is to be started, begins preparation half an hour before it is to be started. First, the second hydrogen side control valve 24 and the second oxygen side control valve 25 are opened simultaneously, and then the second hydrogen pressure gauge 10 and the second oxygen pressure gauge 11 are observed.

[0104] When the system pressure of the second hydrogen pressure gauge 10, the second oxygen pressure gauge 11, and the gas-liquid separator is balanced, the controller controls the opening of the eighth control valve 19, the sixth control valve 17, and the ninth control valve 20 from the inlet of the second electrolyzer 3 to the inlet of the second circulating pump 4; and closes the fifth control valve 16, the seventh control valve 18, the tenth control valve 21 from the inlet of the second electrolyzer 3 to the outlet of the distributor 5, the eleventh control valve 22 from the hydrogen-side gas-liquid outlet of the second electrolyzer 3 to the inlet of the gas-liquid separator, the twelfth control valve 23 from the oxygen-side gas-liquid outlet of the second electrolyzer 3 to the inlet of the gas-liquid separator, the third vent valve 26, and the fourth vent valve 27. While the first circulating pump 2 is running at a flow rate Q1, the second circulating pump 4 is started and runs at a flow rate Q2, so that the liquid in the second electrolyzer 3 is transported to the inlet of the heat exchanger 7.

[0105] The controller is interlocked with the flow regulating valve 8 between the outlet of the first circulating pump 2 and the inlet of the liquid dispenser 5, and the flow meter 9 between the outlet of the first circulating pump 2 and the inlet of the first electrolytic cell 1, to ensure that the liquid flow rate to the first electrolytic cell 1 is Q1. Liquid exceeding Q1 flows to the alkali preparation tank. Based on the first time t1 at which the second circulating pump 4 draws liquid from the second electrolytic cell 3, the controller controls the volume of liquid drawn by the second circulating pump 4 from the second electrolytic cell 3. Through the alkali preparation tank, it can be observed that 90% V2 of the liquid in the second electrolytic cell 3 is replaced, and the volume of the second electrolytic cell 3 is V2.

[0106] Then close the eighth control valve 19, the sixth control valve 17, the ninth control valve 20, the second hydrogen-side control valve 24, and the second oxygen-side control valve 25. Open the third vent valve 26 and the fourth vent valve 27. When the second hydrogen pressure gauge 10 and the second oxygen pressure gauge 11 are around 0.1 MPa, close the third vent valve 26 and the fourth vent valve 27. Open the tenth control valve 21 and start the alkali mixing pump 28 to pump the displaced electrolyte back to the second electrolytic cell 3. In this way, the room temperature liquid in the second electrolytic cell 3 is replaced by the mixed liquid in the liquid distributor 5, and part of the heat generated by the first electrolytic cell 1 is utilized. Moreover, the second electrolytic cell 3 can also be started quickly. The operation schemes for other multiple electrolytic cells are similar. In addition, the control valves in this application can be any one or a combination of manual, pneumatic, and electric types.

[0107] Secondly, such as Figure 3 As shown, taking a hydrogen production system with three electrolyzers connected in parallel to a gas-liquid separation unit as an example, if the first electrolyzer 1 is running, the second electrolyzer 3, which is to be started, will begin preparations half an hour before it is scheduled to start. First, the second hydrogen-side control valve 24, the second oxygen-side control valve 25, and the gas-liquid separator are opened simultaneously. Nitrogen is simultaneously supplied to both the hydrogen and oxygen sides of the second electrolyzer 3 through the nitrogen supply line. The nitrogen supply regulating valve is interlocked through the first nitrogen supply flow meter 29 and the second nitrogen supply flow meter 30 to ensure that the nitrogen flow rates on both the hydrogen and oxygen sides of the second electrolyzer 3 are basically the same. Then, the parameters of the second hydrogen pressure gauge 10 and the second oxygen pressure gauge 11 are observed.

[0108] When the pressures of the second hydrogen pressure gauge 10 and the second oxygen pressure gauge 11 reach the system set pressure, the controller controls the closure of the second hydrogen-side control valve 24 and the second oxygen-side control valve 25. The controller controls the opening of the eighth control valve 19, the sixth control valve 17, and the ninth control valve 20 from the inlet of the second electrolyzer 3 to the inlet of the second circulating pump 4. The controller closes the fifth control valve 16, the seventh control valve 18, the tenth control valve 21 from the inlet of the second electrolyzer 3 to the outlet of the distributor 5, the eleventh control valve 22 from the hydrogen-side gas-liquid outlet of the second electrolyzer 3 to the inlet of the gas-liquid separator, the twelfth control valve 23 from the oxygen-side gas-liquid outlet of the second electrolyzer 3 to the inlet of the gas-liquid separator, the third vent valve 26, and the fourth vent valve 27. While the first circulating pump 2 is running at a flow rate Q1, the second circulating pump 4 is started to run at a flow rate Q2, so that the liquid in the second electrolyzer 3 is transported to the inlet of the heat exchanger 7. For example, the preset pressure can be 1.8 MPa.

[0109] The controller is interlocked with the flow regulating valve 8 between the outlet of the first circulating pump 2 and the inlet of the liquid dispenser 5, and the flow meter 9 between the outlet of the first circulating pump 2 and the inlet of the first electrolytic cell 1, to ensure that the liquid flow rate to the first electrolytic cell 1 is Q1. Liquid exceeding Q1 flows to the alkali preparation tank. Based on the first time t1 at which the second circulating pump 4 draws liquid from the second electrolytic cell 3, the controller controls the volume of liquid drawn by the second circulating pump 4 from the second electrolytic cell 3. Through the alkali preparation tank, it can be observed that 90% V2 of the liquid in the second electrolytic cell 3 is replaced, and the volume of the second electrolytic cell 3 is V2.

[0110] Then close the eighth control valve 19, the sixth control valve 17, the ninth control valve 20, the second hydrogen-side control valve 24, and the second oxygen-side control valve 25. Open the third vent valve 26 and the fourth vent valve 27. When the second hydrogen pressure gauge 10 and the second oxygen pressure gauge 11 are around 0.1 MPa, close the third vent valve 26 and the fourth vent valve 27. Open the tenth control valve 21 and start the alkali mixing pump 28 to pump the displaced electrolyte back to the second electrolytic cell 3. In this way, the room temperature liquid in the second electrolytic cell 3 is replaced by the mixed liquid in the liquid distributor 5, and part of the heat generated by the first electrolytic cell 1 is utilized. Moreover, the second electrolytic cell 3 can also be started quickly. The operation schemes for other multiple electrolytic cells are similar. In addition, the control valves in this application can be any one or a combination of manual, pneumatic, and electric types.

[0111] This application also provides a hydrogen production station, including any of the above-described hydrogen production systems.

[0112] According to the hydrogen production station provided in the embodiments of this application, a hydrogen production system is installed. The inlet of the second circulation pump 4 of the hydrogen production system is connected to the liquid inlet of the second electrolyzer 3, the outlet of the second circulation pump 4 is connected to the inlet of the first path of the heat exchanger 7, the outlet of the liquid distributor 5 is connected to the liquid inlets of the first electrolyzer 1 and the second electrolyzer 3, the inlet of the first circulation pump 2 is connected to the outlet of the first path of the heat exchanger 7, and the outlet of the first circulation pump 2 is connected to the liquid inlet of the first electrolyzer 1 and the inlet of the liquid distributor 5. This allows the hydrogen production system to be used within the heat exchanger 7 to control the operation of the first electrolyzer 1. The high-temperature liquid merges with the room-temperature liquid in the second electrolytic cell 3 when it is ready to start up. The mixed liquid flows back to the first electrolytic cell 1 to continue participating in electrolysis. Another part of the mixed liquid flows to the liquid distributor 5, and then flows into the second electrolytic cell 3 through the liquid distributor 5. This realizes the replacement of the room-temperature liquid in the second electrolytic cell 3 with high-temperature liquid, which can shorten the time for the second electrolytic cell 3 to heat from room-temperature liquid to high-temperature liquid, that is, shorten the time for the second electrolytic cell 3 to enter the normal working state from start-up. At the same time, the excess heat of the first electrolytic cell 1 is recovered and utilized, reducing energy waste.

[0113] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0114] In the description of this application, 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", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0115] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0116] In the description of this application, "multiple" means two or more.

[0117] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them.

[0118] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0119] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0120] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A hydrogen production system, characterized in that, include: The first electrolytic cell and the corresponding first circulating pump; The second electrolytic cell and the corresponding second circulating pump; A liquid mixer, the outlet of which is connected to the inlet of the first electrolytic cell and the second electrolytic cell; A gas-liquid separator, wherein the gas-liquid outlets of the first electrolytic cell and the second electrolytic cell are connected to the inlet of the gas-liquid separator; A heat exchanger, wherein the inlet of the first path of the heat exchanger is connected to the liquid phase outlet of the gas-liquid separator; wherein, The inlet of the first circulating pump is connected to the outlet of the first path of the heat exchanger, and the outlet of the first circulating pump is connected to the inlet of the first electrolytic cell and the inlet of the liquid distributor; the inlet of the second circulating pump is connected to the inlet of the second electrolytic cell, and the outlet of the second circulating pump is connected to the inlet of the first path of the heat exchanger.

2. The hydrogen production system according to claim 1, characterized in that, The first electrolytic cell is an electrolytic cell that has already been started, and the second electrolytic cell is an electrolytic cell that is to be started.

3. The hydrogen production system according to claim 1, characterized in that, Also includes: The controller is equipped with a flow regulating valve between the outlet of the first circulating pump and the inlet of the liquid dispenser, and a flow meter between the outlet of the first circulating pump and the inlet of the first electrolytic cell. The controller is electrically connected to the flow meter and the flow regulating valve and is configured to control the flow regulating valve based on the signal from the flow meter. The flow meter is used to obtain the working flow rate Q1 of the first electrolytic cell.

4. The hydrogen production system according to claim 3, characterized in that, Also includes: The first temperature sensor is used to obtain the liquid inlet temperature T1 of the first electrolytic cell; The second temperature sensor is used to obtain the outlet temperature T2 of the first electrolytic cell; The third temperature sensor is used to obtain the liquid temperature T3 of the second electrolytic cell; The controller is electrically connected to the first temperature sensor, the second temperature sensor, and the third temperature sensor, and is configured to switch the operating states of the second electrolytic cell and the second circulating pump based on the signals from the first temperature sensor, the second temperature sensor, the third temperature sensor, and the flow meter.

5. The hydrogen production system according to claim 1, characterized in that, The hydrogen production system also includes: A nitrogen source is provided, which is connected to the gas-liquid outlets of the first electrolytic cell and the second electrolytic cell, respectively.

6. The hydrogen production system according to claim 1, characterized in that, The gas phase outlet of the gas-liquid separator is connected to the gas-liquid outlets of the first electrolytic cell and the second electrolytic cell, respectively.

7. The hydrogen production system according to any one of claims 1-6, characterized in that, The inlet of the first circulating pump is connected to one of the outlet of the first path of the heat exchanger and the inlet of the first electrolytic cell; the outlet of the first circulating pump is connected to the inlet of the first electrolytic cell and the inlet of the liquid distributor or to the inlet of the first path of the heat exchanger. The inlet of the second circulating pump is connected to one of the outlet of the first path of the heat exchanger and the inlet of the second electrolytic cell; the outlet of the second circulating pump is connected to the inlet of the second electrolytic cell and the inlet of the liquid distributor or to the inlet of the first path of the heat exchanger.

8. The hydrogen production system according to any one of claims 1-6, characterized in that, When the first electrolytic cell and the second electrolytic cell are alkaline electrolytic cells, the liquid dispenser is an alkali dispenser; or, when the first electrolytic cell and the second electrolytic cell are PEM electrolytic cells, the liquid dispenser is a pure water dispenser.

9. The hydrogen production system according to any one of claims 1-6, characterized in that, The gas-liquid separator includes: The hydrogen separator has its inlet connected to the gas-liquid outlets on the hydrogen side of the first electrolytic cell and the second electrolytic cell, respectively, and its liquid phase outlet connected to the inlet of the first path of the heat exchanger. An oxygen separator is provided, wherein the inlet of the oxygen separator is connected to the gas-liquid outlets on the oxygen side of the first electrolytic cell and the second electrolytic cell, respectively, and the liquid outlet of the oxygen separator is connected to the inlet of the first path of the heat exchanger.

10. A hydrogen production system, characterized in that, include: The first electrolytic cell and the corresponding first circulating pump; The second electrolytic cell and the corresponding second circulating pump; A liquid mixer, the outlet of which is connected to the inlet of the first electrolytic cell and the second electrolytic cell; A gas-liquid separator, wherein the gas-liquid outlets of the first electrolytic cell and the second electrolytic cell are connected to the inlet of the gas-liquid separator; A heat exchanger, wherein the inlet of the first path of the heat exchanger is connected to the liquid phase outlet of the gas-liquid separator; A first control valve is provided between the inlet of the first circulating pump and the outlet of the first path of the heat exchanger; a second control valve is provided between the inlet of the first circulating pump and the liquid inlet of the first electrolytic cell; a third control valve is provided between the outlet of the first circulating pump and the liquid inlet of the first electrolytic cell; a flow regulating valve is provided between the outlet of the first circulating pump and the inlet of the liquid distributor; and a fourth control valve is provided between the outlet of the first circulating pump and the inlet of the first path of the heat exchanger. A fifth control valve is provided between the inlet of the second circulating pump and the outlet of the first path of the heat exchanger; a sixth control valve is provided between the inlet of the second circulating pump and the liquid inlet of the second electrolytic cell; a seventh control valve is provided between the outlet of the second circulating pump and the liquid inlet of the second electrolytic cell; and an eighth control valve is provided between the outlet of the second circulating pump and the inlet of the first path of the heat exchanger.

11. A hydrogen production station, characterized in that, Includes the hydrogen production system according to any one of claims 1-10.

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