Water electrolysis hydrogen production system

Abstract

The utility model discloses a water electrolysis hydrogen production system which comprises an electrolytic bath and two gas-liquid separation units, each of the two gas-liquid separation units comprises a gas-liquid separator; a hydrogen side outlet and an oxygen side outlet of the electrolytic bath are respectively communicated with the two gas-liquid separation units; the gas-liquid separators of the two gas-liquid separation units convey electrolyte to the electrolytic bath through a first electrolyte loop and a second electrolyte loop; each of the first electrolyte loop and the second electrolyte loop comprises an electrolyte heat exchanger, a three-way valve and a delivery pump; in the electrolyte loop, an electrolyte inlet of the electrolyte heat exchanger is communicated with the gas-liquid separator of one gas-liquid separation unit, an electrolyte outlet of the electrolyte heat exchanger is communicated with one inlet of a three-way valve, and the other inlet of the three-way valve is communicated with the gas-liquid separator of the other gas-liquid separation unit; an outlet of the three-way valve communicates with the electrolytic bath through a delivery pump; and electrolyte inlets of the electrolyte heat exchangers in the two electrolyte loops are communicated with different gas-liquid separation units. The system is provided with the first electrolyte loop and the second electrolyte loop, redundant design of the electrolyte heat exchanger is achieved, and reliability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen production by water electrolysis, and more specifically, to a hydrogen production system by water electrolysis. Background Art

[0002] Hydrogen production by water electrolysis is a relatively convenient method for producing hydrogen. It is necessary to pass direct current into an electrolytic cell filled with electrolyte, so that water molecules undergo an electrochemical reaction on the electrodes and are decomposed into hydrogen and oxygen.

[0003] The hydrogen production system by water electrolysis includes an electrolytic cell, a gas-liquid separator and a heat exchanger; the hydrogen and electrolyte generated by the electrolytic cell are discharged together, and the hydrogen and electrolyte are separated by a gas-liquid separator; the oxygen generated by the electrolytic cell is discharged together with the electrolyte, and the oxygen and electrolyte are separated by another gas-liquid separator; the hydrogen and oxygen separated by the two gas-liquid separators are collected respectively, and the electrolyte separated by the two gas-liquid separators is passed into the same heat exchanger to dissipate heat and then returned to the electrolytic cell.

[0004] However, the reliability of a single heat exchanger is poor, and a failure will cause the entire hydrogen production system by water electrolysis to shut down, affecting the reliability of hydrogen production.

[0005] Therefore, how to improve the reliability of hydrogen production in the hydrogen production system by water electrolysis is an urgent problem to be solved by those skilled in the art. Summary of the Utility Model

[0006] In view of this, the utility model provides a hydrogen production system by water electrolysis. The electrolyte separated by the two gas-liquid separation units can transport the electrolyte to the electrolytic cell through two electrolyte circuits. Electrolyte heat exchangers are respectively arranged in the two electrolyte circuits. Compared with the design of a single electrolyte heat exchanger in the prior art, redundant design of the electrolyte heat exchanger is realized. When the electrolyte heat exchanger in one electrolyte circuit fails, the electrolyte heat exchanger in the other electrolyte circuit can be used for heat exchange, avoiding the shutdown of the entire hydrogen production system by water electrolysis and improving the reliability of hydrogen production in the hydrogen production system by water electrolysis.

[0007] To achieve the above object, the utility model provides the following technical solutions:

[0008] A hydrogen production system by water electrolysis includes: an electrolytic cell, a first gas-liquid separation unit and a second gas-liquid separation unit; the first gas-liquid separation unit and the second gas-liquid separation unit respectively include a gas-liquid separator; the hydrogen-side outlet of the electrolytic cell is communicated with the first gas-liquid separation unit, and the oxygen-side outlet is communicated with the second gas-liquid separation unit;

[0009] The gas-liquid separators of the first gas-liquid separation unit and the second gas-liquid separation unit can transport the electrolyte to the electrolytic cell through a first electrolyte circuit and a second electrolyte circuit;

[0010] Both the first electrolyte circuit and the second electrolyte circuit include an electrolyte heat exchanger, a three-way valve, and a delivery pump;

[0011] In the first electrolyte circuit, one inlet of the three-way valve is connected to the gas-liquid separator of the first gas-liquid separation unit through the electrolyte heat exchanger, and the other inlet is connected to the gas-liquid separator of the second gas-liquid separation unit. The outlet of the three-way valve is connected to the electrolytic cell through the delivery pump;

[0012] In the second electrolyte circuit, one inlet of the three-way valve is connected to the gas-liquid separator of the second gas-liquid separation unit through the electrolyte heat exchanger, and the other inlet is connected to the gas-liquid separator of the first gas-liquid separation unit. The outlet of the three-way valve is connected to the electrolytic cell through the delivery pump.

[0013] Optionally, in the above hydrogen production system by water electrolysis, there are multiple electrolytic cells;

[0014] The first electrolyte circuit and the second electrolyte circuit are respectively connected to different electrolytic cells; or both the first electrolyte circuit and the second electrolyte circuit are connected to each electrolytic cell; or the first electrolyte circuit and the second electrolyte circuit are connected to both some of the same electrolytic cells and some different electrolytic cells.

[0015] Optionally, in the above hydrogen production system by water electrolysis, there are multiple electrolytic cells;

[0016] The outlet of the three-way valve in the first electrolyte circuit is respectively connected to different multiple electrolytic cells through different first delivery branches; and / or

[0017] The outlet of the three-way valve in the second electrolyte circuit is respectively connected to different multiple electrolytic cells through different second delivery branches.

[0018] Optionally, in the above hydrogen production system by water electrolysis, a delivery pump is respectively provided on each of the first delivery branches; a delivery pump is respectively provided on each of the second delivery branches.

[0019] Optionally, in the above hydrogen production system by water electrolysis, the number of electrolytic cells connected by the three-way valve in the first electrolyte circuit is the same as the number of electrolytic cells connected by the three-way valve in the second electrolyte circuit.

[0020] Optionally, in the above hydrogen production system by water electrolysis, the first gas-liquid separation unit and the second gas-liquid separation unit further respectively include a gas-alkali mixer communicated with the gas-liquid separator; the hydrogen-side outlet of the electrolytic cell is communicated with the gas-alkali mixer of the first gas-liquid separation unit; the oxygen-side outlet of the electrolytic cell is communicated with the gas-alkali mixer of the second gas-liquid separation unit.

[0021] Optionally, in the above hydrogen production system by water electrolysis, the first gas-liquid separation unit and the second gas-liquid separation unit further respectively include a scrubber, a gas heat exchanger, and a gas-water separator that are sequentially communicated; the inlet of the scrubber is communicated with the gas outlet of the gas-liquid separator.

[0022] Optionally, in the above hydrogen production system by water electrolysis, the first gas-liquid separation unit and the second gas-liquid separation unit further respectively include a tank body, the inlet of the tank body is communicated with the liquid outlet of the gas-water separator, and the outlet of the tank body is communicated with the gas-liquid separator; a first valve is provided on the connecting pipeline between the tank body and the gas-water separator, and a second valve is provided on the connecting pipeline between the tank body and the gas-liquid separator; the first valve and the second valve are used to be opened at different times respectively.

[0023] Optionally, in the above hydrogen production system by water electrolysis, in any gas-liquid separation unit, the tank body is located below the gas-water separator, and the gas-liquid separator is located below the tank body.

[0024] Optionally, in the above hydrogen production system by water electrolysis, a liquid level regulating valve is provided on the gas outlet connecting pipeline of the gas-water separator in the first gas-liquid separation unit; a pressure regulating valve is provided on the gas outlet connecting pipeline of the gas-water separator in the second gas-liquid separation unit.

[0025] The present utility model provides a hydrogen production system by water electrolysis, including an electrolytic cell, a first gas-liquid separation unit, and a second gas-liquid separation unit; the first gas-liquid separation unit and the second gas-liquid separation unit respectively include a gas-liquid separator; the hydrogen-side outlet of the electrolytic cell is communicated with the first gas-liquid separation unit, and the oxygen-side outlet is communicated with the second gas-liquid separation unit; the gas-liquid separators of the first gas-liquid separation unit and the second gas-liquid separation unit can transport electrolyte to the electrolytic cell through a first electrolyte circuit and a second electrolyte circuit; both the first electrolyte circuit and the second electrolyte circuit include an electrolyte heat exchanger, a three-way valve, and a delivery pump; in the first electrolyte circuit, one inlet of the three-way valve is communicated with the gas-liquid separator of the first gas-liquid separation unit through the electrolyte heat exchanger, the other inlet is communicated with the gas-liquid separator of the second gas-liquid separation unit, and the outlet of the three-way valve is communicated with the electrolytic cell through the delivery pump; in the second electrolyte circuit, one inlet of the three-way valve is communicated with the gas-liquid separator of the second gas-liquid separation unit through the electrolyte heat exchanger, the other inlet is communicated with the gas-liquid separator of the first gas-liquid separation unit, and the outlet of the three-way valve is communicated with the electrolytic cell through the delivery pump.

[0026] In the above hydrogen production system by electrolyzing water, the electrolyte separated by the two gas-liquid separation units can be transported to the electrolyzer through the first and second electrolyte circuits. Electrolyte heat exchangers are respectively provided in the two electrolyte circuits. Compared with the single electrolyte heat exchanger in the prior art, a redundant design of the electrolyte heat exchanger is achieved. When the electrolyte heat exchanger in one electrolyte circuit fails, the electrolyte heat exchanger in the other electrolyte circuit can be used to exchange heat for the electrolyte, avoiding the shutdown of the entire hydrogen production system by electrolyzing water and improving the hydrogen production reliability of the hydrogen production system by electrolyzing water.

[0027] In addition, in the above hydrogen production system by electrolyzing water, both the first and second electrolyte circuits include three-way valves. One inlet of the three-way valve is connected to the gas-liquid separator of one gas-liquid separation unit through the electrolyte heat exchanger, and the other inlet is connected to the gas-liquid separator of the other gas-liquid separation unit. Then, the electrolyte (at a lower temperature) after heat exchange by the electrolyte heat exchanger is mixed with the electrolyte (at a higher temperature) in the gas-liquid separator and then returned to the electrolyzer. During application, the heat exchange efficiency of the electrolyte heat exchanger can be maintained within a relatively high preset range, and then the opening degree of the three-way valve is adjusted to adjust the proportion of the electrolytes at the two temperatures, thereby flexibly adjusting the temperature of the electrolyte flowing back to the electrolyzer, avoiding the temperature of the electrolyte flowing back to the electrolyzer being too high or too low, making the temperature of the electrolyte flowing back to the electrolyzer adapt to the actual needs of the electrolyzer, avoiding problems such as low gas production and high power consumption caused by too low electrolyte temperature in the electrolyzer, and avoiding problems such as excessive electrolyte discharge and increased corrosion risk of the entire system caused by too high electrolyte temperature in the electrolyzer. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram of the hydrogen production system by electrolyzing water provided by the embodiment of the present invention;

[0030] Among them, Figure 1 In:

[0031] Liquid level regulating valve 101; Pressure regulating valve 102; Gas heat exchanger 103; Gas-water separator 104; First valve 105; Tank body 106; Scrubber 107; Second valve 108; Gas-liquid separator 109; Connecting pipe 110; Gas-alkali mixer 111; Electrolyte heat exchanger 112; Three-way valve 113; Delivery pump 114; Flowmeter 115; Electrolyzer 116; First gas-liquid separation unit 10; Second gas-liquid separation unit 20. Specific embodiments

[0032] An embodiment of the present invention discloses a water electrolysis hydrogen production system. The electrolyte separated by its two gas-liquid separation units can be transported to the electrolyzer through two electrolyte circuits, and electrolyte heat exchangers are respectively provided in the two electrolyte circuits. Compared with the design of a single electrolyte heat exchanger in the prior art, redundant design of the electrolyte heat exchanger is realized. When the electrolyte heat exchanger in one electrolyte circuit fails, the electrolyte heat exchanger in the other electrolyte circuit can be used for heat exchange, avoiding the shutdown of the entire water electrolysis hydrogen production system and improving the hydrogen production reliability of the water electrolysis hydrogen production system.

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Please refer to Figure 1, an embodiment of the present utility model provides a water electrolysis hydrogen production system, which includes an electrolytic cell 116, a first gas-liquid separation unit 10, and a second gas-liquid separation unit 20; the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 each include a gas-liquid separator 109; the hydrogen-side outlet of the electrolytic cell 116 is communicated with the first gas-liquid separation unit 10, and the oxygen-side outlet is communicated with the second gas-liquid separation unit 20; the gas-liquid separators 109 of the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 can transport electrolyte to the electrolytic cell 116 through a first electrolyte circuit and a second electrolyte circuit; both the first electrolyte circuit and the second electrolyte circuit include an electrolyte heat exchanger 112, a three-way valve 113, and a delivery pump 114; in the first electrolyte circuit, one inlet of the three-way valve 113 is communicated with the gas-liquid separator 109 of the first gas-liquid separation unit 10 through the electrolyte heat exchanger 112 of the first electrolyte circuit, and the other inlet is communicated with the gas-liquid separator 109 of the second gas-liquid separation unit 20, and the outlet of the three-way valve 113 is communicated with the electrolytic cell 116 through the delivery pump 114 of the first electrolyte circuit; in the second electrolyte circuit, one inlet of the three-way valve 113 is communicated with the gas-liquid separator 109 of the second gas-liquid separation unit 20 through the electrolyte heat exchanger 112 in the second electrolyte circuit, and the other inlet is communicated with the gas-liquid separator 109 of the first gas-liquid separation unit 10, and the outlet of the three-way valve 113 is communicated with the electrolytic cell 116 through the delivery pump 114 in the second electrolyte circuit.

[0035] In the above water electrolysis hydrogen production system, the electrolyte separated by the two gas-liquid separation units can transport electrolyte to the electrolytic cell 116 through the first and second electrolyte circuits. The electrolyte heat exchangers 112 are respectively provided in the two electrolyte circuits. Compared with the single electrolyte heat exchanger in the prior art, the redundant design of the electrolyte heat exchanger 112 is realized. When the electrolyte heat exchanger 112 in one electrolyte circuit fails, the electrolyte heat exchanger 112 in the other electrolyte circuit can be used to heat and cool the electrolyte, avoiding the shutdown of the entire water electrolysis hydrogen production system and improving the hydrogen production reliability of the water electrolysis hydrogen production system.

[0036] In addition, in the above hydrogen production system by electrolyzing water, both the first electrolyte circuit and the second electrolyte circuit include a three-way valve 113. One inlet of the three-way valve 113 is connected to the gas-liquid separator 109 of a gas-liquid separation unit through an electrolyte heat exchanger 112, and the other inlet is connected to the gas-liquid separator 109 of another gas-liquid separation unit. Then, the electrolyte (at a lower temperature) after heat exchange in the electrolyte heat exchanger 112 is mixed with the electrolyte (at a higher temperature) in the gas-liquid separator 109 and then returned to the electrolytic cell 116. During application, the heat exchange efficiency of the electrolyte heat exchanger 112 can be maintained within a relatively high preset range, and then the opening degree of the three-way valve 113 is adjusted to adjust the proportion of the electrolytes at two temperatures, thereby flexibly adjusting the temperature of the electrolyte flowing back to the electrolytic cell 116, avoiding the temperature of the electrolyte flowing back to the electrolytic cell 116 being too high or too low, making the temperature of the electrolyte flowing back to the electrolytic cell 116 adapt to the actual needs of the electrolytic cell 116, avoiding problems such as low gas production and high power consumption in the electrolytic cell 116 due to too low electrolyte temperature, and avoiding problems such as excessive electrolyte discharge in the electrolytic cell 116 due to too high electrolyte temperature, which increases the corrosion risk of the entire system.

[0037] Furthermore, in the above hydrogen production system by electrolyzing water, the electrolyte inlets of the electrolyte heat exchangers 112 in the first electrolyte circuit and the second electrolyte circuit are connected to the gas-liquid separators 109 of different gas-liquid separation units, so that the gas-liquid separator 109 of the first gas-liquid separation unit 10 supplies electrolyte to both the electrolyte heat exchanger 112 in the first electrolyte circuit and the three-way valve 113 in the second electrolyte circuit, and the gas-liquid separator 109 of the second gas-liquid separation unit 10 supplies electrolyte to both the electrolyte heat exchanger 112 in the second electrolyte circuit and the three-way valve 113 in the first electrolyte circuit. This is beneficial to ensuring the balanced consumption of the electrolyte in the gas-liquid separators 109 in the first and second gas-liquid separation units, helping to reduce the liquid level difference in the gas-liquid separators 109 in the first and second gas-liquid separation units, and is beneficial to improving the safety of the entire hydrogen production system by electrolyzing water.

[0038] In the above hydrogen production system by electrolyzing water, the electrolytic cell 116 can be set to one, or can also be set to multiple.

[0039] When multiple electrolytic cells 116 are provided, the hydrogen-side outlets of each electrolytic cell 116 are respectively connected to the first gas-liquid separation unit 10, and the oxygen-side outlets of each electrolytic cell 116 are respectively connected to the second gas-liquid separation unit 20, forming a structure in which multiple electrolytic cells 116 are connected in parallel, and can respectively produce crude hydrogen products and crude oxygen products to achieve the purpose of hydrogen production.

[0040] When multiple electrolyzers 116 are provided, the first electrolyte circuit and the second electrolyte circuit can be arranged to communicate with different electrolyzers 116 respectively. In the solution provided in this embodiment, the first electrolyte circuit and the second electrolyte circuit communicate with different electrolyzers 116 respectively, so that when one electrolyte circuit fails, the other electrolyte circuit can operate normally, improving the reliability and production efficiency of the whole system.

[0041] Of course, when multiple electrolyzers 116 are provided, the first electrolyte circuit and the second electrolyte circuit can also be arranged to communicate with each electrolyzer 116, or the first electrolyte circuit and the second electrolyte circuit communicate with both some of the same electrolyzers 116 and some different electrolyzers 116. This embodiment does not limit the connection relationship between the first and second electrolyte circuits and the multiple electrolyzers 116, and only needs to ensure that each electrolyzer 116 is connected to at least one electrolyte circuit to obtain electrolyte to realize the hydrogen production function.

[0042] In the above hydrogen production system by water electrolysis, the outlet of the three-way valve 113 in the first electrolyte circuit can be connected to only one electrolyzer 116, and the outlet of the three-way valve 113 in the second electrolyte circuit can also be arranged to be connected to only one electrolyzer 116; correspondingly, if there is one electrolyzer 116, the outlets of the three-way valves 113 in the first and second electrolyte circuits are connected to the same electrolyzer 116; if there are two electrolyzers 116, the outlets of the three-way valves 113 in the first and second electrolyte circuits are connected to different electrolyzers 116.

[0043] The outlets of the three-way valves 113 in the first and second electrolyte circuits can also be connected to multiple electrolyzers 116 respectively. In one embodiment, the outlet of the three-way valve 113 in the first electrolyte circuit is connected to different multiple electrolyzers 116 through different first delivery branches; and / or the outlet of the three-way valve 113 in the second electrolyte circuit is connected to different multiple electrolyzers 116 through different second delivery branches.

[0044] Delivery pumps 114 are respectively provided on each of the first delivery branches; delivery pumps 114 are respectively provided on each of the second delivery branches. Flow meters can also be respectively provided on each of the first delivery branches and each of the second delivery branches.

[0045] In some embodiments, the number of electrolyzers 116 connected to the outlet of the three-way valve 113 in the first electrolyte circuit is the same as the number of electrolyzers 116 connected to the outlet of the three-way valve 113 in the second electrolyte circuit.

[0046] In the above hydrogen production system by water electrolysis, the gas-liquid separators 109 of the two gas-liquid separation units are connected through a connecting pipe 110; the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed along the vertical direction.

[0047] The first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed vertically. The gas-liquid separator 109 including the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 is symmetrically distributed vertically.

[0048] In the technical solution provided in this embodiment, the gas-liquid separators 109 of the first and second gas-liquid separation units form a communicating vessel structure through the connecting pipe 110, which helps to balance the liquid levels in the gas-liquid separators 109 on the hydrogen side and the oxygen side in the water electrolysis hydrogen production system. At the same time, in the solution provided in this embodiment, the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed vertically and form a communicating vessel structure, so that the volumes of the electrolyte in the gas-liquid separators 109 in the first and second gas-liquid separation units are close, ensuring that the two gas-liquid separators 109 act simultaneously to supply an appropriate amount of electrolyte to each electrolytic cell 116.

[0049] Furthermore, in the technical solution provided in this embodiment, although the first and second gas-liquid separation units form a communicating vessel structure through the connecting pipe 110, the electrolyte inlets of the electrolyte heat exchangers 112 in the first electrolyte circuit and the second electrolyte circuit are connected to the gas-liquid separators 109 of different gas-liquid separation units, and one inlet of the three-way valves 113 in the first and second electrolyte circuits is directly connected to the gas-liquid separators 109 of different gas-liquid separation units, which is beneficial to the balanced consumption of the electrolyte in the gas-liquid separators 109 of the first and second gas-liquid separation units, preventing excessive consumption of the electrolyte in one gas-liquid separator 109, while the electrolyte in the other gas-liquid separator 109 flows into this gas-liquid separator 109 through the connecting pipe 110 too much, avoiding a large amount of gas being carried by the electrolyte into this gas-liquid separator 109 resulting in the mixing of hydrogen and oxygen.

[0050] In addition, in the solution provided in this embodiment, the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically arranged, the number of electrolytic cells 116 connected by the first and second electrolyte circuits is the same, when the flow rates in the first and second electrolyte circuits are the same and the power of each electrolytic cell 116 is the same, the consumption of the electrolyte in the gas-liquid separator 109 of the first gas-liquid separation unit 10 and the consumption of the electrolyte in the gas-liquid separator 109 of the second gas-liquid separation unit 20 in the whole system can reach a basic balance, greatly reducing the adjustment frequency of the hydrogen-side liquid level regulating valve 101 and improving the stability of the system.

[0051] Of course, the number of electrolytic cells 116 connected by the first electrolyte circuit and the number of electrolytic cells 116 connected by the second electrolyte circuit may also be set to be different, and this embodiment does not make a limitation.

[0052] Specifically, the first gas-liquid separation unit 10 is connected to the hydrogen side of each electrolytic cell 116, and the second gas-liquid separation unit 20 is connected to the oxygen side of each electrolytic cell 116; a liquid level regulating valve 101 is provided on the gas outlet connecting pipe of the gas-water separator 104 in the first gas-liquid separation unit 10; a pressure regulating valve 102 is provided on the gas outlet connecting pipe of the gas-water separator 104 in the second gas-liquid separation unit 20.

[0053] The first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 also respectively include a gas-alkali mixer 111 connected to the gas-liquid separator 109; the hydrogen-side outlet of the electrolytic cell 116 is connected to the gas-alkali mixer 111 of the first gas-liquid separation unit 10; the oxygen-side outlet of the electrolytic cell 116 is connected to the gas-alkali mixer 111 of the second gas-liquid separation unit 20. The gas-alkali mixer 111 can be set as a vertical mixer.

[0054] In each gas-liquid separation unit, the gas-alkali mixer 111 is installed below the gas-liquid separator 109, and the diameter of the gas-alkali mixer 111 is larger than the diameter of the connecting pipe of the hydrogen-side outlet or the oxygen-side outlet of the electrolytic cell 116, reducing the interference between the head of the transfer pumps 114 on each transfer branch in the electrolyte circuit, and at the same time providing a sufficient rising channel for hydrogen or oxygen, facilitating the collection and separation of bubbles.

[0055] The first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 also respectively include a scrubber 107, a gas heat exchanger 103, and a gas-water separator 104 connected in sequence; the inlet of the scrubber 107 is connected to the gas outlet of the gas-liquid separator 109.

[0056] In the technical solution provided by this embodiment, each gas-liquid separation unit not only includes a gas-liquid separator 109, but also includes a gas heat exchanger 103 and a gas-water separator 104, which can respectively recover the water on the hydrogen side and the oxygen side, achieve zero emissions, and save water resources.

[0057] The first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 also respectively include a tank body 106, the inlet of the tank body 106 is connected to the liquid outlet of the gas-water separator 104, and the outlet of the tank body 106 is connected to the gas-liquid separator 109; a first valve 105 is provided on the connecting pipeline between the tank body 106 and the gas-water separator 104, and a second valve 108 is provided on the connecting pipeline between the tank body 106 and the gas-liquid separator 109; the first valve 105 and the second valve 108 are used to be opened at different times respectively.

[0058] In the above gas-liquid separation unit, the tank body 106 is located below the gas-water separator 104, and the gas-liquid separator 109 is located below the tank body 106.

[0059] When the liquid level in the gas-liquid separator 104 of the first gas-liquid separation unit 10 on the hydrogen side is high, the first valve 105 is opened. When the pressures of the tank body 106 and the gas-liquid separator 104 are balanced, water flows back into the tank body 106 by gravity until the water in the gas-liquid separator 104 is drained or the liquid level no longer changes, then the first valve 105 is closed. Then, the second valve 108 is opened. When the pressures of the tank body 106 and the gas-liquid separator 109 are balanced, water flows back into the gas-liquid separator 109 by gravity until it is drained. In such a cycle, the first valve 105 and the second valve 108 of the first gas-liquid separation unit 10 are interlocked and cannot be opened simultaneously. The interlocking process of the first valve 105 and the second valve 108 in the second gas-liquid separation unit 20 on the oxygen side is the same as that on the hydrogen side and will not be elaborated here.

[0060] In this embodiment, "the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed vertically" can be set to further include: the gas-alkali mixers 111 of the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed vertically, the scrubbers 107 of the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed vertically, the gas heat exchangers 103 of the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed vertically, the gas-liquid separators 104 of the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed vertically, and the tank bodies 106 of the first gas-liquid separation unit 10 and the second gas-liquid separation unit 20 are symmetrically distributed vertically.

[0061] The water electrolysis hydrogen production system provided by the present utility model has a simple structure and a redundant design, which is beneficial to improving the overall production efficiency.

[0062] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0063] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present utility model. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present utility model. Therefore, the present utility model will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A water electrolysis hydrogen production system, characterized in that: include: an electrolytic cell, a first gas-liquid separation unit and a second gas-liquid separation unit; The first gas-liquid separation unit and the second gas-liquid separation unit each include a gas-liquid separator; The hydrogen side outlet of the electrolyzer is connected to the first gas-liquid separation unit, and the oxygen side outlet is connected to the second gas-liquid separation unit; The gas-liquid separators of the first gas-liquid separation unit and the second gas-liquid separation unit can transport electrolyte to the electrolytic cell through the first electrolyte loop and the second electrolyte loop; The first electrolyte circuit and the second electrolyte circuit both include an electrolyte heat exchanger, a three-way valve and a delivery pump; In the first electrolyte circuit, one inlet of the three-way valve is connected to the gas-liquid separator of the first gas-liquid separation unit through the electrolyte heat exchanger, and the other inlet is connected to the gas-liquid separator of the second gas-liquid separation unit, and the outlet of the three-way valve is connected to the electrolytic cell through the delivery pump; In the second electrolyte circuit, one inlet of the three-way valve is connected to the gas-liquid separator of the second gas-liquid separation unit through the electrolyte heat exchanger, and the other inlet is connected to the gas-liquid separator of the first gas-liquid separation unit, and the outlet of the three-way valve is connected to the electrolytic cell through the delivery pump.

2. The water electrolysis hydrogen production system according to claim 1, characterized in that: There are multiple electrolytic cells; The first electrolyte circuit and the second electrolyte circuit are respectively connected to different electrolytic cells; or the first electrolyte circuit and the second electrolyte circuit are both connected to each electrolytic cell; or the first electrolyte circuit and the second electrolyte circuit are connected to both some of the same electrolytic cells and some of the different electrolytic cells.

3. The water electrolysis hydrogen production system according to claim 1, characterized in that: There are multiple electrolytic cells; The outlet of the three-way valve in the first electrolyte circuit is connected to different multiple electrolytic cells through different first delivery branches; and / or The outlet of the three-way valve in the second electrolyte circuit is connected to different multiple electrolytic cells through different second delivery branches.

4. The water electrolysis hydrogen production system according to claim 3, characterized in that: The delivery pump is provided on each of the first delivery branches; and the delivery pump is provided on each of the second delivery branches.

5. The water electrolysis hydrogen production system according to claim 3, characterized in that: The number of the electrolytic cells connected to the three-way valve in the first electrolyte circuit is the same as the number of the electrolytic cells connected to the three-way valve in the second electrolyte circuit.

6. The water electrolysis hydrogen production system according to claim 1, characterized in that: The first gas-liquid separation unit and the second gas-liquid separation unit also respectively include a gas-alkali mixer connected to the gas-liquid separator; the hydrogen side outlet of the electrolyzer is connected to the gas-alkali mixer of the first gas-liquid separation unit; and the oxygen side outlet of the electrolyzer is connected to the gas-alkali mixer of the second gas-liquid separation unit.

7. The water electrolysis hydrogen production system according to claim 6, characterized in that: The first gas-liquid separation unit and the second gas-liquid separation unit further respectively include a scrubber, a gas heat exchanger, and a gas-water separator which are connected in sequence; the inlet of the scrubber is connected to the gas outlet of the gas-liquid separator.

8. The water electrolysis hydrogen production system according to claim 7, characterized in that: The first gas-liquid separation unit and the second gas-liquid separation unit also include a tank body, respectively, the inlet of the tank body is connected to the liquid outlet of the gas-water separator, and the outlet of the tank body is connected to the gas-liquid separator; a first valve is provided on the connecting pipeline between the tank body and the gas-water separator, and a second valve is provided on the connecting pipeline between the tank body and the gas-liquid separator; the first valve and the second valve are used to be opened at different times.

9. The water electrolysis hydrogen production system according to claim 8, characterized in that: In any gas-liquid separation unit, the tank body is located below the gas-water separator, and the gas-liquid separator is located below the tank body.

10. The water electrolysis hydrogen production system according to claim 7, characterized in that: A liquid level regulating valve is provided on the gas outlet connecting pipe of the gas-water separator in the first gas-liquid separation unit; a pressure regulating valve is provided on the gas outlet connecting pipe of the gas-water separator in the second gas-liquid separation unit.

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