PEM water electrolysis hydrogen production system

Abstract

The utility model discloses a PEM water electrolysis hydrogen production system which comprises a PEM electrolytic bath, a hydrogen separator and an oxygen separator, a water outlet of the oxygen separator is connected with a water inlet of the PEM electrolytic bath, and the PEM water electrolysis hydrogen production system further comprises a first liquid level meter, a second liquid level meter, a communicating pipeline and a first control valve; the bottom of the hydrogen separator is connected with the bottom of the oxygen separator through the communicating pipeline, the first liquid level meter is arranged on the hydrogen separator, the second liquid level meter is arranged on the oxygen separator, and the first control valve is arranged on the communicating pipeline; the first liquid level meter is used for measuring the liquid level of the hydrogen separator, the second liquid level meter is used for measuring the liquid level of the oxygen separator, and the first control valve is used for controlling opening or closing of the communicating pipeline. When the PEM water electrolysis hydrogen production system is applied, water generated by hydrogen side separation can be recycled, and gas mixing between the hydrogen separator and the oxygen separator is not prone to occurring.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by electrolysis of water, and in particular to a PEM water electrolysis hydrogen production system. Background Art

[0002] PEM (Proton Exchange Membrane) water electrolysis is a technology that uses a proton exchange membrane as an electrolyte and pure water as a reactant to produce hydrogen. Specifically, PEM water electrolysis is usually carried out in a PEM electrolyzer. Water molecules are first decomposed into oxygen and hydrogen ions under the catalytic action of the anode catalyst. The hydrogen ions then pass through the PEM membrane between the anode and cathode, and then generate hydrogen under the catalytic action of the cathode catalyst. The hydrogen and oxygen produced by the reaction are mixed with water to form a gas-liquid mixture. The hydrogen-side gas-liquid mixture enters the hydrogen-side gas-liquid separator (hereinafter referred to as the "hydrogen separator") for gas-liquid separation to obtain hydrogen and water. The oxygen-side gas-liquid mixture enters the oxygen-side gas-liquid separator (hereinafter referred to as the "oxygen separator") for gas-liquid separation to obtain oxygen and water. The separated hydrogen and oxygen enter the subsequent process.

[0003] Currently, the oxygen separator in PEM water electrolysis hydrogen production systems is often connected to the PEM electrolyzer via a circulating water pipeline. This allows the water separated from the oxygen side to be returned to the PEM electrolyzer, achieving water recycling. However, given the potential for hydrogen gas in the water produced by the hydrogen separator, which poses an explosion risk, the hydrogen separator typically drains the separated water directly out of the system via a connected drain pipe. This approach clearly wastes water resources and increases the cost of PEM water electrolysis hydrogen production.

[0004] To recycle the water produced during hydrogen separation, PEM electrolysis systems connect the hydrogen and oxygen separators at the bottom via a connecting pipe. This allows the water produced during hydrogen separation to enter the oxygen separator and then flow back to the PEM electrolyzer through a circulating water line connected to the oxygen separator. However, when there is a large pressure difference between the hydrogen and oxygen separators, the gases inside the two gas-liquid separators can easily cross-contaminate through the connecting pipe, potentially causing an explosion.

[0005] Therefore, how to provide a solution to overcome or alleviate the above-mentioned defects is still a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0006] The purpose of this application is to provide a PEM water electrolysis hydrogen production system to recycle the water generated by hydrogen side separation and prevent gas cross-contamination between the hydrogen separator and the oxygen separator.

[0007] To solve the above technical problems, the present application provides a PEM water electrolysis hydrogen production system, comprising a PEM electrolyzer, a hydrogen separator and an oxygen separator, wherein the water outlet of the oxygen separator is connected to the water inlet of the PEM electrolyzer, and the PEM water electrolysis hydrogen production system further comprises a first liquid level gauge, a second liquid level gauge, a connecting pipeline and a first control valve;

[0008] The bottom of the hydrogen separator and the bottom of the oxygen separator are connected via the connecting pipe, a first liquid level gauge is provided on the hydrogen separator, the second liquid level gauge is provided on the oxygen separator, and the first control valve is provided on the connecting pipe;

[0009] The first liquid level gauge is used to measure the liquid level of the hydrogen separator, the second liquid level gauge is used to measure the liquid level of the oxygen separator, and the first control valve is used to control the opening or closing of the connecting pipeline.

[0010] Optionally, the PEM water electrolysis hydrogen production system further includes a controller;

[0011] The first liquid level gauge, the second liquid level gauge and the first control valve are respectively connected to the controller, and the controller is used to control the opening or closing of the first control valve according to the liquid level.

[0012] Optionally, the PEM water electrolysis hydrogen production system further includes a second control valve and a relay;

[0013] The second control valve is provided in the communicating pipeline, the first liquid level gauge, the second liquid level gauge and the second control valve are respectively connected to the relay, and the first liquid level gauge and the second liquid level gauge are both high and low limit type liquid level gauges;

[0014] The first liquid level meter is used to send a closing signal to the relay when the measured liquid level reaches the limit value, and the second liquid level meter is used to send a closing signal to the relay when the measured liquid level reaches the limit value. The relay is used to control the second control valve to close when receiving the closing signal.

[0015] Optionally, the second control valve is a normally closed control valve.

[0016] Optionally, the PEM water electrolysis hydrogen production system further includes a first pressure gauge, a second pressure gauge and a controller;

[0017] The first pressure gauge is provided on the hydrogen separator, and the second pressure gauge is provided on the oxygen separator;

[0018] The first pressure gauge, the second pressure gauge and the first control valve are respectively connected to the controller, the first pressure gauge is used to measure the pressure of the hydrogen separator, and the second pressure gauge is used to measure the pressure of the oxygen separator; the controller is used to control the opening or closing of the first control valve according to the pressure.

[0019] Optionally, the PEM water electrolysis hydrogen production system further includes a first gas outlet pipeline, a second gas outlet pipeline, a first gas outlet valve and a second gas outlet valve;

[0020] The first gas outlet pipeline is connected to the gas outlet of the hydrogen separator, the second gas outlet pipeline is connected to the gas outlet of the oxygen separator, the first gas outlet valve is provided on the first gas outlet pipeline, and the second gas outlet valve is provided on the second gas outlet pipeline;

[0021] The first gas outlet valve and the second gas outlet valve are respectively connected to the controller, and the controller is used to control the opening of the first gas outlet valve according to the pressure of the hydrogen separator, and the controller is used to control the opening of the second gas outlet valve according to the pressure of the oxygen separator.

[0022] Optionally, the PEM water electrolysis hydrogen production system further includes a drain pipeline and a drain valve;

[0023] The drainage pipeline is connected to the water outlet of the hydrogen separator, and the drainage valve is provided on the drainage pipeline. The drainage valve is used to control the opening or closing of the drainage pipeline.

[0024] Optionally, the PEM water electrolysis hydrogen production system further includes a heat exchanger and a flow pump;

[0025] The water outlet of the oxygen separator and the water inlet of the PEM electrolyzer are connected through a circulating water pipeline. The heat exchanger and the flow pump are both arranged in the circulating water pipeline. The heat exchanger is used to cool the circulating water in the circulating water pipeline.

[0026] The PEM water electrolysis hydrogen production system provided in the present application is connected by a connecting pipe at the bottom of the hydrogen separator and the oxygen separator, and a first liquid level gauge is provided in the hydrogen separator, a second liquid level gauge is provided in the oxygen separator, and a first control valve is provided in the connecting pipe. When in use, the liquid level of the hydrogen separator can be measured by the first liquid level gauge, the liquid level of the oxygen separator can be measured by the second liquid level gauge, and the opening or closing of the first control valve can be controlled according to the liquid level data, thereby controlling the opening or closing of the connecting pipe. In this way, when the liquid levels of the hydrogen separator and the oxygen separator are within the normal range, the connecting pipe is opened, so that the water generated by the gas-liquid separation of the hydrogen separator flows to the oxygen separator and flows back to the PEM electrolyzer to recycle the water generated by the hydrogen side separation, save water resources, and thus reduce the cost of PEM water electrolysis hydrogen production. When the liquid level of the hydrogen separator or the oxygen separator is outside the normal range and may cause the two separators to cross-gas, the connecting pipe is closed, so that it is not easy to cross-gas between the hydrogen separator and the oxygen separator, reducing the risk of explosion, thereby improving the safety of PEM water electrolysis hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of a PEM water electrolysis hydrogen production system according to the first embodiment of the present application;

[0028] Figure 2 This is a structural schematic diagram of the PEM water electrolysis hydrogen production system provided in the second embodiment of this application.

[0029] The reference numerals in the above drawings are described as follows:

[0030] 1-PEM electrolyzer;

[0031] 2-hydrogen separator;

[0032] 3- oxygen separator;

[0033] 41-first liquid level gauge, 42-second liquid level gauge;

[0034] 51-connecting pipeline, 52-circulating water pipeline, 53-first delivery pipeline, 54-second delivery pipeline, 55-drainage pipeline, 56-first air outlet pipeline, 57-second air outlet pipeline;

[0035] 61-first control valve, 62-second control valve, 63-drain valve, 64-first air outlet valve, 65-second air outlet valve;

[0036] 71-controller, 72-relay;

[0037] 81-first pressure gauge, 82-second pressure gauge;

[0038] 91 - heat exchanger, 92 - flow pump, 93 - first temperature measuring device, 94 - second temperature measuring device, 95 - electrolysis power supply. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0040] It should be noted that the terms "first", "second", etc. in this application are only used to facilitate the description of two or more structures or components with the same or similar structures and / or functions, and do not imply any special limitation on the order and / or importance.

[0041] In this application, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, it can mean a fixed connection, a detachable connection, or an integral connection; it can mean a mechanical connection or a communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean internal communication between two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0042] Please refer to Figure 1 , Figure 1 This is a structural schematic diagram of the PEM water electrolysis hydrogen production system provided in the first embodiment of this application.

[0043] In the first embodiment provided in the present application, the PEM water electrolysis hydrogen production system includes a PEM electrolyzer 1, a hydrogen separator 2, an oxygen separator 3, a first liquid level gauge 41, a second liquid level gauge 42, a connecting pipe 51 and a first control valve 61; the water outlet of the oxygen separator 3 is connected to the water inlet of the PEM electrolyzer 1. Specifically, the two can be connected through a circulating water pipe 52, so that the water inside the oxygen separator 3 can flow back to the PEM electrolyzer 1 through the circulating water pipe 52. The bottom of the hydrogen separator 2 and the bottom of the oxygen separator 3 are connected through a connecting pipe 51, the first liquid level gauge 41 is provided in the hydrogen separator 2, the second liquid level gauge 42 is provided in the oxygen separator 3, and the first control valve 61 is provided in the connecting pipe 51. Among them, the first liquid level gauge 41 is used to measure the liquid level of the hydrogen separator 2, the second liquid level gauge 42 is used to measure the liquid level of the oxygen separator 3, and the first control valve 61 is used to control the opening or closing of the connecting pipe 51.

[0044] During use, the first liquid level gauge 41 can be used to measure the liquid level of the hydrogen separator 2, and the second liquid level gauge 42 can be used to measure the liquid level of the oxygen separator 3. The opening or closing of the first control valve 61 can be controlled according to the liquid level data, thereby controlling the opening or closing of the connecting pipeline 51.

[0045] It is not difficult to understand that the connecting pipe 51 can realize the connection between the hydrogen separator 2 and the oxygen separator 3, and the liquid levels of the hydrogen separator 2 and the oxygen separator 3 can reflect their respective pressure changes. When the pressure difference between the hydrogen separator 2 and the oxygen separator 3 is large, the liquid levels of the two will change greatly, so that the liquid level data can also reflect whether cross-gas is likely to occur between the hydrogen separator 2 and the oxygen separator 3.

[0046] In this way, when the liquid level of the hydrogen separator 2 and the liquid level of the oxygen separator 3 are both within the normal liquid level range, the first control valve 61 can be controlled to open, thereby opening the connecting pipe 51 and conducting the connection between the hydrogen separator 2 and the oxygen separator 3. The water generated by the gas-liquid separation in the hydrogen separator 2 can enter the oxygen separator 3 through the connecting pipe 51, and then can flow back to the PEM electrolyzer 1 through the circulating water pipe 52 connected to the oxygen separator 3, thereby realizing the recycling of the water separated from the hydrogen side, saving water resources, and correspondingly reducing the cost of hydrogen production by PEM electrolysis of water; when the liquid level of the hydrogen separator 2 or When the liquid level of the oxygen separator 3 is outside the normal liquid level range, the hydrogen obtained by gas-liquid separation inside the hydrogen separator 2 can easily enter the oxygen separator 3 through the connecting pipe 51, or the oxygen obtained by gas-liquid separation inside the oxygen separator 3 can easily enter the hydrogen separator 2 through the connecting pipe 51, that is, the hydrogen separator 2 and the oxygen separator 3 may cross-gas. Due to the setting of the first control valve 61, the connecting pipe 51 can be closed by closing the first control valve 61, thereby cutting off the connection between the hydrogen separator 2 and the oxygen separator 3, which can reduce the risk of cross-gas between the two and correspondingly improve the safety of PEM water electrolysis hydrogen production. Among them, the above-mentioned normal liquid level range may have a liquid level lower limit value and a liquid level upper limit value. When the liquid level is lower than the liquid level lower limit value or higher than the liquid level upper limit value, the liquid level is outside the normal liquid level range.

[0047] It is worth noting that the opening or closing of the first control valve 61 can be controlled directly according to the liquid level of the hydrogen separator 2 or the liquid level of the oxygen separator 3 as described above, or the liquid level difference between the two can be calculated according to the liquid level of the hydrogen separator 2 and the liquid level of the oxygen separator 3, and the opening or closing of the first control valve 61 can be controlled according to the liquid level difference. For example, when the liquid level difference is large, the first control valve 61 can be closed. There is no specific limitation.

[0048] In actual use, the opening or closing of the first control valve 61 can be controlled manually or automatically by a control device, and there is no specific limitation.

[0049] In the first embodiment provided in the present application, the PEM water electrolysis hydrogen production system also includes a controller 71; the first liquid level gauge 41, the second liquid level gauge 42 and the first control valve 61 are respectively connected to the controller 71, and the controller 71 is used to control the opening or closing of the first control valve 61 according to the liquid level.

[0050] It is not difficult to understand that the first liquid level gauge 41 and the second liquid level gauge 42 can be liquid level gauges with a data remote transmission function. After the first liquid level gauge 41 and the second liquid level gauge 42 obtain the corresponding liquid level data, the corresponding liquid level data can be transmitted to the controller 71 respectively. The controller 71 automatically sends an opening signal or a closing signal to the first control valve 61 according to the liquid level of the hydrogen separator 2 or the liquid level of the oxygen separator 3 or calculates and according to the liquid level difference between the hydrogen separator 2 and the oxygen separator 3 to control the opening or closing of the first control valve 61, thereby improving the control efficiency, which is beneficial to the timely recycling of the water obtained by gas-liquid separation on the hydrogen side, and is also beneficial to timely closing the channel connecting the hydrogen separator 2 and the oxygen separator 3 when there is a large pressure difference between the two, reducing the risk of cross-gas, so as to further improve the utilization rate of the water separated on the hydrogen side and the safety of PEM water electrolysis to produce hydrogen.

[0051] It is worth noting that the controller 71 can be a PLC controller or a DCS controller, without any specific limitation.

[0052] In the first embodiment provided in the present application, the PEM water electrolysis hydrogen production system also includes a second control valve 62 and a relay 72; the second control valve 62 is arranged in the connecting pipeline 51, and the first liquid level gauge 41, the second liquid level gauge 42 and the second control valve 62 are respectively connected to the relay 72, and the first liquid level gauge 41 and the second liquid level gauge 42 are both high and low limit liquid level gauges; the first liquid level gauge 41 is used to send a closing signal to the relay 72 when the measured liquid level reaches the limit value, and the second liquid level gauge 42 is used to send a closing signal to the relay 72 when the measured liquid level reaches the limit value, and the relay 72 is used to control the second control valve 62 to close when receiving the closing signal.

[0053] It is not difficult to understand that the first liquid level gauge 41 and the second liquid level gauge 42 are high-low limit type liquid level gauges, both of which can have an upper limit sensor and a lower limit sensor. When the liquid level of the hydrogen separator 2 or the oxygen separator 3 reaches the limit (the upper limit of the liquid level or the lower limit of the liquid level), the corresponding upper limit sensor or lower limit sensor will be activated, sending a shutdown signal to the relay 72. This shutdown signal can control the second control valve 62 to close through the relay 72, thereby controlling the closure of the connecting pipeline 51. In this way, when there is a possibility of cross-contamination between the hydrogen separator 2 and the oxygen separator 3, the relay 72 can be used to promptly cut off the connection between the two, reducing the risk of cross-contamination. Of course, the role of the relay 72 is more than that. When the controller 71 malfunctions and fails, the relay 72 can "bypass" the controller 71 and directly determine that the liquid level of the hydrogen separator 2 or the oxygen separator 3 has reached the limit, thereby promptly shutting off the second control valve 62. It can be seen that the relay 72 can provide another layer of protection for the control of the connectivity status of the connecting pipeline 51, so that even without the "supervision" of the controller 71, it can also ensure that the hydrogen separator 2 and the oxygen separator 3 are not prone to cross-gas, making the PEM water electrolysis hydrogen production process safer.

[0054] In specific configuration, the structural forms of the first control valve 61 and the second control valve 62 are not limited.

[0055] In the first embodiment provided herein, the second control valve 62 is a normally closed control valve. It is understood that the normally closed second control valve 62 is closed when powered off and can only be opened upon receiving an opening signal from the controller 71. This prevents water within the hydrogen separator 2 from entering the oxygen separator 3 without control. Furthermore, when the liquid level in either the hydrogen separator 2 or the oxygen separator 3 reaches a limit, triggering the operation of the relay 72, the relay 72 can be used to de-energize the second control valve 62 and close it. This makes the recycling process of the water separated from the hydrogen side safer.

[0056] Of course, the first control valve 61 may also be a normally closed control valve, and its specific function will not be described in detail.

[0057] In this embodiment, the first control valve 61 and the second control valve 62 can be pneumatic ball valves that can be opened and closed quickly, thereby enabling rapid opening or closing of the connecting pipeline 51. This can further improve the utilization efficiency of the water separated from the hydrogen side and the safety of hydrogen production by PEM electrolysis. Furthermore, the structure is compact and the cost is low. Furthermore, when the first control valve 61 and the second control valve 62 are normally closed control valves, if the circuit or gas path connected to their pneumatic actuators fails, both valves automatically close, thereby isolating the hydrogen separator 2 from the oxygen separator 3, further ensuring the safety of the water recovery and utilization of the water separated from the hydrogen side.

[0058] The first embodiment of the present application collects the liquid level data of the hydrogen separator 2 and the oxygen separator 3 to reflect the pressure changes of the two to control the connection between the two. Of course, the pressure data of the two can also be directly collected to control the connection between the two, and there is no specific limitation.

[0059] Please refer to Figure 2 , Figure 2 This is a structural schematic diagram of the PEM water electrolysis hydrogen production system provided in the second embodiment of this application.

[0060] In the second embodiment provided in the present application, the PEM water electrolysis hydrogen production system also includes a first pressure gauge 81 and a second pressure gauge 82; the first pressure gauge 81 is provided in the hydrogen separator 2, and the second pressure gauge 82 is provided in the oxygen separator 3; the first pressure gauge 81 is used to measure the pressure of the hydrogen separator 2, and the second pressure gauge 82 is used to measure the pressure of the oxygen separator 3.

[0061] It is not difficult to understand that the pressure of the hydrogen separator 2 can be measured using the first pressure gauge 81, and the pressure of the oxygen separator 3 can be measured using the second pressure gauge 82, so that the pressure difference between the hydrogen separator 2 and the oxygen separator 3 can be calculated. When the pressure difference is lower than the preset pressure threshold, the first control valve 61 can be controlled to remain open so that the water separated by the hydrogen separator 2 can be recycled. When the pressure difference exceeds the preset pressure difference threshold, the first control valve 61 can be controlled to close, so that the connecting pipe 51 between the hydrogen separator 2 and the oxygen separator 3 is closed, reducing the risk of cross-gas and ensuring the safety of PEM water electrolysis for hydrogen production. It is worth noting that the control of the connection between the hydrogen separator 2 and the oxygen separator 3 can be performed only based on the pressure data as described above. In addition, the control of the connection between the two can also be performed based on the liquid level data and the pressure data. Specifically, when either of the two conditions, that the liquid level data is outside the normal range and the pressure difference exceeds the pressure difference threshold, the connecting pipe 51 can be controlled to close. In this way, the reflection of the pressure changes inside the hydrogen separator 2 and the oxygen separator 3 is more accurate, which is conducive to further ensuring the safety of the recycling process of the water separated by the hydrogen separator 2.

[0062] In the second embodiment of the present application, since a controller 71 is provided, the first pressure gauge 81 and the second pressure gauge 82 can be connected to the controller 71 respectively, and the controller 71 can be used to automatically control the opening or closing of the first control valve 61 according to the pressure to improve the working efficiency of the water recovery process obtained by hydrogen side separation.

[0063] like Figure 2 As shown, in the second embodiment of the present application, the PEM water electrolysis hydrogen production system also includes a first gas outlet pipeline 56, a second gas outlet pipeline 57, a first gas outlet valve 64 and a second gas outlet valve 65; the first gas outlet pipeline 56 is connected to the gas outlet of the hydrogen separator 2, the second gas outlet pipeline 57 is connected to the gas outlet of the oxygen separator 3, the first gas outlet valve 64 is arranged on the first gas outlet pipeline 56, and the second gas outlet valve 65 is arranged on the second gas outlet pipeline 57; the first gas outlet valve 64 and the second gas outlet valve 65 are respectively connected to the controller 71, and the controller 71 is used to control the opening of the first gas outlet valve 64 according to the pressure of the hydrogen separator 2, and the controller 71 is used to control the opening of the second gas outlet valve 65 according to the pressure of the oxygen separator 3.

[0064] In this way, the controller 71 can be used to control the opening of the first outlet valve 64 of the first outlet pipeline 56 and the second outlet valve 65 of the second outlet pipeline 57 according to the pressure data of the hydrogen separator 2 and the oxygen separator 3, so as to control the flow rate of hydrogen and oxygen respectively, thereby realizing automatic adjustment of the pressure of the two and further ensuring the safety of the PEM water electrolysis hydrogen production process.

[0065] In the embodiment provided in the present application, the PEM water electrolysis hydrogen production system also includes a drain pipe 55 and a drain valve 63; the drain pipe 55 is connected to the water outlet of the hydrogen separator 2, and the drain valve 63 is arranged on the drain pipe 55, and the drain valve 63 is used to control the opening or closing of the drain pipe 55.

[0066] It is not difficult to understand that the drain valve 63 can be connected to the controller 71 to control the opening or closing of the drain valve 63 according to the liquid level data or pressure data of the hydrogen separator 2, thereby controlling the opening or closing of the drain pipe 55. For example, when the liquid level of the hydrogen separator 2 is higher than the upper limit of the liquid level, the drain valve 63 can be controlled to open to discharge the water separated by the hydrogen separator 2 from the hydrogen separator 2 through the drain pipe 55, which can further ensure the safety of the PEM water electrolysis hydrogen production process.

[0067] In the embodiment provided in the present application, the PEM water electrolysis hydrogen production system also includes a heat exchanger 91 and a flow pump 92; the water outlet of the oxygen separator 3 and the water inlet of the PEM electrolyzer 1 are connected through a circulating water pipeline 52, and the heat exchanger 91 and the flow pump 92 are both arranged in the circulating water pipeline 52, and the heat exchanger 91 is used to cool the circulating water in the circulating water pipeline 52.

[0068] It can be understood that the heat medium inlet and heat medium outlet of the heat exchanger 91 can be connected to the circulating water pipeline 52. Specifically, the heat medium inlet can be connected to the water outlet of the oxygen separator 3 through the circulating water pipeline 52, and the heat medium outlet can be connected to the PEM electrolyzer 1 through the circulating water pipeline 52. The circulating water can enter the heat exchanger 91 through the heat medium inlet and perform heat exchange with the cooling medium, such as coolant, introduced into the heat exchanger 91 to achieve cooling of the circulating water. The cooled circulating water can flow out of the heat exchanger 91 through the heat medium outlet; the flow pump 92 is used to pump the circulating water in the circulating water pipeline 52 so that the circulating water flows back to the PEM electrolyzer 1. The flow pump 92 can also be connected to an external water source to replenish the electrolyte for the PEM electrolyzer 1 when the electrolyte is consumed and needs to be replenished.

[0069] In the examples provided in this application, Figure 1 and Figure 2 As shown, the PEM water electrolysis hydrogen production system also includes an electrolysis power supply 95, a first temperature measuring device 93 and a second temperature measuring device 94. The electrolysis power supply 95 can be connected to the PEM electrolyzer 1 to provide power to the PEM electrolyzer 1. The hydrogen side outlet of the PEM electrolyzer 1 can be connected to the inlet of the hydrogen separator 2 through the first delivery pipeline 53, and the oxygen side outlet of the PEM electrolyzer 1 can be connected to the inlet of the oxygen separator 3 through the second delivery pipeline 54. The first temperature measuring device 93 can be provided on the first delivery pipeline 53 to measure the temperature of the hydrogen side after the PEM electrolyzer 1. The second temperature measuring device 94 can be provided on the second delivery pipeline 54 to measure the temperature of the oxygen side after the PEM electrolyzer 1.

[0070] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only intended to help understand the device and its core concept of this application. It should be noted that for those skilled in the art, without departing from the principles of this application, various improvements and modifications can be made to this application, and such improvements and modifications also fall within the scope of protection of the claims of this application.

Claims

1. A PEM water electrolysis hydrogen production system, comprising a PEM electrolyzer (1), a hydrogen separator (2) and an oxygen separator (3), wherein the water outlet of the oxygen separator (3) is connected to the water inlet of the PEM electrolyzer (1), characterized in that: The PEM water electrolysis hydrogen production system further includes a first liquid level gauge (41), a second liquid level gauge (42), a connecting pipeline (51) and a first control valve (61); The bottom of the hydrogen separator (2) and the bottom of the oxygen separator (3) are connected via the connecting pipe (51); a first liquid level gauge (41) is provided on the hydrogen separator (2); the second liquid level gauge (42) is provided on the oxygen separator (3); and the first control valve (61) is provided on the connecting pipe (51); The first liquid level gauge (41) is used to measure the liquid level of the hydrogen separator (2), the second liquid level gauge (42) is used to measure the liquid level of the oxygen separator (3), and the first control valve (61) is used to control the opening or closing of the connecting pipeline (51).

2. The PEM water electrolysis hydrogen production system according to claim 1, characterized in that: The PEM water electrolysis hydrogen production system further includes a controller (71); The first liquid level gauge (41), the second liquid level gauge (42) and the first control valve (61) are respectively connected to the controller (71), and the controller (71) is used to control the opening or closing of the first control valve (61) according to the liquid level.

3. The PEM water electrolysis hydrogen production system according to claim 2, characterized in that: The PEM water electrolysis hydrogen production system further includes a second control valve (62) and a relay (72); The second control valve (62) is provided in the connecting pipeline (51), the first liquid level gauge (41), the second liquid level gauge (42) and the second control valve (62) are respectively connected to the relay (72), and the first liquid level gauge (41) and the second liquid level gauge (42) are both high and low limit type liquid level gauges; The first liquid level meter (41) is used to send a closing signal to the relay (72) when the measured liquid level reaches a limit value, the second liquid level meter (42) is used to send a closing signal to the relay (72) when the measured liquid level reaches a limit value, and the relay (72) is used to control the second control valve (62) to close when receiving the closing signal.

4. The PEM water electrolysis hydrogen production system according to claim 3, characterized in that: The second control valve (62) is a normally closed control valve.

5. The PEM water electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: The PEM water electrolysis hydrogen production system further includes a first pressure gauge (81), a second pressure gauge (82) and a controller (71); The first pressure gauge (81) is provided on the hydrogen separator (2), and the second pressure gauge (82) is provided on the oxygen separator (3); The first pressure gauge (81), the second pressure gauge (82) and the first control valve (61) are respectively connected to the controller (71), the first pressure gauge (81) is used to measure the pressure of the hydrogen separator (2), and the second pressure gauge (82) is used to measure the pressure of the oxygen separator (3); the controller (71) is used to control the opening or closing of the first control valve (61) according to the pressure.

6. The PEM water electrolysis hydrogen production system according to claim 5, characterized in that: The PEM water electrolysis hydrogen production system further includes a first gas outlet pipeline (56), a second gas outlet pipeline (57), a first gas outlet valve (64) and a second gas outlet valve (65); The first gas outlet pipeline (56) is connected to the gas outlet of the hydrogen separator (2), the second gas outlet pipeline (57) is connected to the gas outlet of the oxygen separator (3), the first gas outlet valve (64) is provided on the first gas outlet pipeline (56), and the second gas outlet valve (65) is provided on the second gas outlet pipeline (57); The first gas outlet valve (64) and the second gas outlet valve (65) are respectively connected to the controller (71), and the controller (71) is used to control the opening of the first gas outlet valve (64) according to the pressure of the hydrogen separator (2), and the controller (71) is used to control the opening of the second gas outlet valve (65) according to the pressure of the oxygen separator (3).

7. The PEM water electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: The PEM water electrolysis hydrogen production system further includes a drainage pipeline (55) and a drainage valve (63); The drainage pipeline (55) is connected to the water outlet of the hydrogen separator (2), and the drainage valve (63) is provided on the drainage pipeline (55). The drainage valve (63) is used to control the opening or closing of the drainage pipeline (55).

8. The PEM water electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: The PEM water electrolysis hydrogen production system further includes a heat exchanger (91) and a flow pump (92); The water outlet of the oxygen separator (3) and the water inlet of the PEM electrolyzer (1) are connected via a circulating water pipeline (52). The heat exchanger (91) and the flow pump (92) are both provided in the circulating water pipeline (52). The heat exchanger (91) is used to cool the circulating water in the circulating water pipeline (52).

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