Water electrolysis system based on proton exchange membrane

Abstract

The invention discloses a water electrolysis system based on a proton exchange membrane. The water electrolysis system comprises an electrolytic bath group, an anode circulation system and a cathode circulation system, the anode circulating system comprises a first connecting pipe, two ends of the first connecting pipe are respectively connected with an anode water inlet and an anode water outlet of the electrolytic bath group, the anode water outlet is used for discharging an anode solution mixed with oxygen, and a first pump body, an oxygen separation unit and an anode cooling unit are arranged on the first connecting pipe; the cathode circulating system comprises a second connecting pipe, two ends of the second connecting pipe are respectively connected with a cathode water inlet and a cathode water outlet of the electrolytic bath group, the cathode water outlet is used for discharging a cathode solution mixed with hydrogen, and a second pump body, a hydrogen separation unit and a cathode cooling unit are arranged on the second connecting pipe. According to the water electrolysis system based on the proton exchange membrane, by arranging the separation unit, the water outlet is used for discharging a solution mixed with gas, effective gas-liquid separation can be achieved, the recycling rate of the solution is increased, and therefore the electrolysis efficiency of the electrolytic bath set is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of water electrolysis, and in particular to a water electrolysis system based on a proton exchange membrane. Background Art

[0002] Since the product of hydrogen combustion is water, which is pollution-free to the environment, water electrolysis is widely used in the field of renewable energy power generation technology as a low-cost method for hydrogen production.

[0003] The renewable hydrogen and oxygen fuel cell energy storage and supply system is mainly divided into two parts: the proton exchange membrane electrolyzer and the hydrogen and oxygen fuel cell. Among them, the proton exchange membrane electrolyzer plays an energy storage role. The proton exchange membrane electrolyzer can use electricity to electrolyze water into hydrogen and oxygen. The proton exchange membrane electrolyzer has the advantages of high current density, renewable, pollution-free, and fast startup speed. It is an efficient and clean energy utilization storage device, and the hydrogen and oxygen fuel cell plays an energy supply role. The specific working principle is: connect the hydrogen and oxygen fuel cell with the power generation device. When the electricity consumption is low, the proton exchange membrane electrolyzer in the system uses excess electricity to electrolyze pure water to produce hydrogen and oxygen, and store them in the hydrogen and oxygen storage devices respectively; when the electricity consumption is peak, hydrogen and oxygen are introduced into the hydrogen and oxygen fuel cell to undergo chemical reactions to generate electricity to supplement the power supply, which can store the excess electricity in the renewable energy system for use when the system is underpowered. For energy storage, hydrogen can also be stored separately as fuel energy storage.

[0004] However, the proton exchange membrane electrolyzer of the existing proton exchange membrane water electrolysis system generates heat during the process of electrolytic hydrogen production. Currently, this heat is usually discharged by the flow of water in the electrolyzer and naturally cooled through the circulation pipeline. The cooling effect is poor, which affects the electrolysis efficiency of the proton exchange membrane electrolyzer. Summary of the invention

[0005] The object of the present invention is to provide a water electrolysis system based on a proton exchange membrane, which has a simple structure and a good cooling effect of a cooling unit.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] Provided is a water electrolysis system based on a proton exchange membrane, comprising an electrolytic cell group, an anode circulation system and a cathode circulation system, wherein the electrolytic cell group has an anode water inlet, an anode water outlet, a cathode water inlet and a cathode water outlet, wherein the anode water outlet is used to discharge an anode solution mixed with oxygen, and the cathode water outlet is used to discharge a cathode solution mixed with hydrogen; the anode circulation system comprises a first connecting pipe, wherein two ends of the first connecting pipe are respectively connected to the anode water inlet and the anode water outlet, wherein a first pump body, an oxygen separation unit and an anode cooling unit are arranged on the first connecting pipe, wherein the oxygen separation unit can separate the oxygen from the anode solution, and wherein the anode cooling unit can cool the anode solution in the first connecting pipe; and the cathode circulation system comprises a second connecting pipe, wherein two ends of the second connecting pipe are respectively connected to the cathode water inlet and the cathode water outlet, wherein a second pump body, a hydrogen separation unit and a cathode cooling unit are arranged on the second connecting pipe, wherein the hydrogen separation unit can separate the hydrogen from the cathode solution, and wherein the cathode cooling unit can cool the cathode solution in the second connecting pipe.

[0008] As a preferred solution of the proton exchange membrane-based water electrolysis system, the cell group includes at least two proton exchange membrane electrolyzers connected in series.

[0009] As a preferred solution of the proton exchange membrane-based water electrolysis system, the cell group includes a first proton exchange membrane electrolyzer, a second proton exchange membrane electrolyzer and a third proton exchange membrane electrolyzer, and each proton exchange membrane electrolyzer is provided with the anode water inlet, the anode water outlet, the cathode water inlet and the cathode water outlet, the first connecting pipe has a first end and a second end opposite to each other, the first end is connected to the anode water inlet of the first proton exchange membrane electrolyzer, the anode water outlet of the first proton exchange membrane electrolyzer is connected to the anode water inlet of the second proton exchange membrane electrolyzer through a first branch pipe, the anode water outlet of the second proton exchange membrane electrolyzer is connected to the anode water inlet of the third proton exchange membrane electrolyzer through a second branch pipe, and the anode water outlet of the third proton exchange membrane electrolyzer is connected to the second end;

[0010] The second connecting pipe has a third end and a fourth end opposite to each other, the third end is connected to the cathode water inlet of the first proton exchange membrane electrolyzer, the cathode water outlet of the first proton exchange membrane electrolyzer is connected to the cathode water inlet of the second proton exchange membrane electrolyzer through a third branch pipe, the cathode water outlet of the second proton exchange membrane electrolyzer is connected to the cathode water inlet of the third proton exchange membrane electrolyzer through a fourth branch pipe, and the cathode water outlet of the third proton exchange membrane electrolyzer is connected to the fourth end.

[0011] As a preferred solution of the proton exchange membrane-based water electrolysis system, a first control valve is provided on the first branch pipe, the first branch pipe is connected to the second end through a first connecting pipe, and the connection between the first connecting pipe and the first branch pipe is located between the anode water outlet of the first proton exchange membrane electrolyzer and the first control valve, and a second control valve is provided on the first connecting pipe;

[0012] The second branch pipe is provided with a third control valve, the second branch pipe is connected to the second end through a second connecting pipe, and the connection between the second connecting pipe and the second branch pipe is located between the anode water outlet of the second proton exchange membrane electrolyzer and the third control valve, and the second connecting pipe is provided with a fourth control valve;

[0013] The anode water outlet of the third proton exchange membrane electrolyzer is connected to the second end through a third connecting pipe, and a fifth control valve is provided on the third connecting pipe;

[0014] The third branch pipe is provided with a sixth control valve, the third branch pipe is connected to the third end through a fourth connecting pipe, and the connection between the fourth connecting pipe and the third branch pipe is located between the cathode water outlet of the first proton exchange membrane electrolyzer and the sixth control valve, and the fourth connecting pipe is provided with a seventh control valve;

[0015] The fourth branch pipe is provided with an eighth control valve, the fourth branch pipe is connected to the fourth end through a fifth connecting pipe, and the connection between the fifth connecting pipe and the fourth branch pipe is located between the cathode water outlet of the second proton exchange membrane electrolyzer and the eighth control valve, and the fifth connecting pipe is provided with a ninth control valve;

[0016] The cathode water outlet of the third proton exchange membrane electrolyzer is connected to the fourth end through a sixth connecting pipe, and a tenth control valve is provided on the sixth connecting pipe.

[0017] As a preferred solution of the water electrolysis system based on proton exchange membrane, the electrolytic cell group further includes a buffer tank, and the buffer tank is provided at the connection between each branch pipe and the connecting pipe.

[0018] As a preferred solution of the water electrolysis system based on proton exchange membrane, the oxygen separation unit includes an anode gas-liquid separator, an oxygen pipe, an oxygen dryer and an oxygen control valve, the anode gas-liquid separator is arranged on the first connecting pipe, the oxygen pipe is connected to the anode gas-liquid separator, and the oxygen dryer and the oxygen control valve are arranged on the oxygen pipe;

[0019] The hydrogen separation unit includes a cathode gas-liquid separator, a hydrogen pipe, a hydrogen dryer, a hydrogen control valve and a hydrogen storage tank. The cathode gas-liquid separator is arranged on the second connecting pipe, and the two ends of the hydrogen pipe are respectively connected to the cathode gas-liquid separator and the hydrogen storage tank. The hydrogen dryer and the hydrogen control valve are arranged on the hydrogen pipe.

[0020] As a preferred solution of the water electrolysis system based on proton exchange membrane, liquid level sensors are provided in both the anode gas-liquid separator and the cathode gas-liquid separator.

[0021] As a preferred solution of the water electrolysis system based on proton exchange membrane, the anode circulation system also includes an anode water replenishment unit, which includes an anode water replenishment jet pump, an anode water replenishment pipe, an anode water replenishment check valve and an anode water replenishment control valve. The anode water replenishment jet pump is arranged on the first connecting pipe, and the two ends of the anode water replenishment pipe are respectively connected to the anode water replenishment jet pump and the water replenishment tank, and the anode water replenishment pipe is provided with the anode water replenishment check valve and the anode water replenishment control valve; and / or,

[0022] The cathode circulation system also includes a cathode water replenishment unit, which includes a cathode water replenishment jet pump, a cathode water replenishment pipe, a cathode water replenishment one-way valve and a cathode water replenishment control valve. The cathode water replenishment jet pump is arranged on the second connecting pipe, and the two ends of the cathode water replenishment pipe are respectively connected to the cathode water replenishment jet pump and the water replenishment tank, and the cathode water replenishment pipe is provided with the cathode water replenishment one-way valve and the cathode water replenishment control valve.

[0023] As a preferred solution of the water electrolysis system based on proton exchange membrane, the anode cooling unit includes an anode heat exchanger, an anode radiator and an anode coolant circulation pump, wherein the anode heat exchanger is arranged on the first connecting pipe, the inner cavity of the anode heat exchanger has a coolant, the inner cavity of the anode radiator is communicated with the inner cavity of the anode heat exchanger, and the anode coolant circulation pump is arranged between the anode heat exchanger and the anode radiator;

[0024] The cathode cooling unit includes a cathode heat exchanger, a cathode radiator and a cathode coolant circulation pump. The cathode heat exchanger is arranged on the second connecting pipe. The inner cavity of the cathode heat exchanger has coolant. The inner cavity of the cathode radiator is communicated with the inner cavity of the cathode heat exchanger. The cathode coolant circulation pump is arranged between the cathode heat exchanger and the cathode radiator.

[0025] As a preferred solution of the proton exchange membrane-based water electrolysis system, the anode circulation system further includes an anode filtration unit, the anode filtration unit includes an anode filter and an anode deionizer arranged on the first connecting pipe, and the anode deionizer is located between the anode filter and the anode water inlet of the cell group;

[0026] The cathode circulation system further comprises a cathode filter unit, which comprises a cathode filter and a cathode deionizer arranged on the second connecting pipe, and the cathode deionizer is located between the cathode filter and the cathode water inlet of the cell group.

[0027] The beneficial effects of the present invention are as follows: by arranging an oxygen separation unit on the first connecting pipe, the anode water outlet used to discharge the anode solution mixed with oxygen can be effectively separated from the oxygen, and the recovery rate of the anode solution is improved, thereby ensuring the electrolysis efficiency of the cell group, and the setting of the anode cooling unit can effectively release the heat of the anode solution, avoid the temperature of the recycled anode solution being too high to affect the electrolysis efficiency of the cell group, and ensure the service life and use stability of the cell group; by arranging a hydrogen separation unit on the second connecting pipe, the cathode water outlet used to discharge the cathode solution mixed with hydrogen can be effectively separated from the hydrogen, and the recovery rate of the cathode solution is improved, thereby ensuring the electrolysis efficiency of the cell group, and the setting of the cathode cooling unit can effectively release the heat of the cathode solution, avoid the temperature of the recycled cathode solution being too high to affect the electrolysis efficiency of the cell group, and ensure the service life and use stability of the cell group. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described in detail below based on the accompanying drawings and embodiments.

[0029] Figure 1 is a schematic diagram of a process of a proton exchange membrane-based water electrolysis system according to an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of the coordination between the anode circulation system and the cell group of an embodiment of the present invention;

[0031] Figure 3 It is a schematic diagram of the coordination between the cathode circulation system and the cell group according to an embodiment of the present invention.

[0032] In the figure:

[0033] 1. Cell group; 11. First proton exchange membrane electrolyzer; 12. Second proton exchange membrane electrolyzer; 13. Third proton exchange membrane electrolyzer; 14. First branch pipe; 15. Second branch pipe; 16. Third branch pipe; 17. Fourth branch pipe; 18.1. First control valve; 18.2. Second control valve; 18.3. Third control valve; 18.4. Fourth control valve; 18.5. Fifth control valve; 18.6. Sixth control valve; 18.7. Seventh control valve; 18.8. Eighth control valve; 18.9. Ninth control valve ; 18.10, tenth control valve; 19.1, first connecting pipe; 19.2, second connecting pipe; 19.3, third connecting pipe; 19.4, fourth connecting pipe; 19.5, fifth connecting pipe; 19.6, sixth connecting pipe; 20, buffer tank; 2, anode circulation system; 21, first connecting pipe; 211, first end; 212, second end; 22, first pump body; 23, anode separation unit; 231, anode gas-liquid separator; 232, oxygen pipe; 233, oxygen dryer; 234, oxygen control valve; 2 4. Anode cooling unit; 241. Anode heat exchanger; 242. Anode radiator; 243. Anode coolant circulation pump; 25. Anode water supply unit; 251. Anode water supply jet pump; 252. Anode water supply pipe; 253. Anode water supply check valve; 254. Anode water supply control valve; 26. Anode filter unit; 261. Anode filter; 262. Anode deionizer; 3. Cathode circulation system; 31. Second connecting pipe; 311. Third end; 312. Fourth end; 32. Second pump body; 33. Hydrogen separation unit element; 331, cathode gas-liquid separator; 332, hydrogen pipe; 333, hydrogen dryer; 334, hydrogen control valve; 335, hydrogen tank; 34, cathode cooling unit; 341, cathode heat exchanger; 342, cathode radiator; 343, cathode coolant circulation pump; 35, cathode water replenishment unit; 351, cathode water replenishment jet pump; 352, cathode water replenishment pipe; 353, cathode water replenishment check valve; 354, cathode water replenishment control valve; 36, cathode filtration unit; 361, cathode filter; 362, cathode deionizer. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0035] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0038] like Figures 1 to 3 As shown, the water electrolysis system based on proton exchange membrane of the embodiment of the present invention comprises an electrolytic cell group 1, an anode circulation system 2 and a cathode circulation system 3, the electrolytic cell group 1 has an anode water inlet, an anode water outlet, a cathode water inlet and a cathode water outlet, the anode water outlet is used to discharge an anode solution mixed with oxygen, and the cathode water outlet is used to discharge a cathode solution mixed with hydrogen; the anode circulation system 2 comprises a first connecting pipe 21, the two ends of the first connecting pipe 21 are respectively connected to the anode water inlet and the anode water outlet, and the first connecting pipe 21 is provided with a first pump body 22, an oxygen separator 24 and a cathode pump body 25. The cathode circulation system 3 comprises a second connecting pipe 31, and the two ends of the second connecting pipe 31 are respectively connected to the cathode water inlet and the cathode water outlet. The second connecting pipe 31 is provided with a second pump body 32, a hydrogen separation unit 33 and a cathode cooling unit 34. The hydrogen separation unit 33 can separate hydrogen and the cathode solution, and the cathode cooling unit 34 can cool the cathode solution in the second connecting pipe 31.

[0039] It can be understood that, by providing the first pump body 22, it is possible to provide circulation power for the anode solution in the first connecting pipe 21, thereby ensuring the operational stability of the water electrolysis system. By providing the oxygen separation unit on the first connecting pipe 21, the anode water outlet used to discharge the anode solution mixed with oxygen can be effectively separated from the oxygen, thereby improving the recycling rate of the anode solution, thereby ensuring the electrolysis efficiency of the cell group 1. In addition, the provision of the anode cooling unit 24 can effectively release the heat of the anode solution, thereby avoiding the temperature of the recycled anode solution being too high and affecting the electrolysis efficiency of the cell group 1, thereby ensuring the service life and stability of the cell group 1. Qualitative; by setting the second pump body 32, it can provide circulation power for the cathode solution in the second connecting pipe 31, and ensure the operation stability of the water electrolysis system. By setting the hydrogen separation unit 33 on the second connecting pipe 31, the cathode water outlet is used to discharge the cathode solution mixed with hydrogen and can be effectively separated from the hydrogen, so as to improve the recovery rate of the cathode solution, thereby ensuring the electrolysis efficiency of the cell group 1, and the setting of the cathode cooling unit 34 can effectively release the heat of the cathode solution, avoid the temperature of the recycled cathode solution being too high and affect the electrolysis efficiency of the cell group 1, and ensure the service life and use stability of the cell group 1.

[0040] Furthermore, the cell group 1 includes at least two proton exchange membrane electrolyzers connected in series. The anode water inlet and the anode water outlet of all the proton exchange membrane electrolyzers are connected end to end in sequence, and the cathode water inlet and the cathode water outlet of all the proton exchange membrane electrolyzers are connected end to end in sequence. By setting up a plurality of proton exchange membrane electrolyzers, different numbers of proton exchange membrane electrolyzers can be independently selected to electrolyze water to produce hydrogen according to production needs, thereby enhancing the adaptability of the proton exchange membrane-based water electrolysis system under renewable energy power generation conditions.

[0041] Specifically, the cell group 1 includes a first proton exchange membrane electrolyzer 11, a second proton exchange membrane electrolyzer 12 and a third proton exchange membrane electrolyzer 13, and each proton exchange membrane electrolyzer is provided with an anode water inlet, an anode water outlet, a cathode water inlet and a cathode water outlet, a first connecting pipe 21 has a first end 211 and a second end 212 opposite to each other, the first end 211 is connected to the anode water inlet of the first proton exchange membrane electrolyzer 11, the anode water outlet of the first proton exchange membrane electrolyzer 11 is connected to the anode water inlet of the second proton exchange membrane electrolyzer 12 through a first branch pipe 14, and the anode water outlet of the second proton exchange membrane electrolyzer 12 is connected to the anode water inlet of the third proton exchange membrane electrolyzer 13 through a second branch pipe 15. The anode water inlet of the proton exchange membrane electrolyzer 13 and the anode water outlet of the third proton exchange membrane electrolyzer 13 are connected to the second end 212; the second connecting pipe 31 has a third end 311 and a fourth end 312 opposite to each other, the third end 311 is connected to the cathode water inlet of the first proton exchange membrane electrolyzer 11, the cathode water outlet of the first proton exchange membrane electrolyzer 11 is connected to the cathode water inlet of the second proton exchange membrane electrolyzer 12 through the third branch pipe 16, the cathode water outlet of the second proton exchange membrane electrolyzer 12 is connected to the cathode water inlet of the third proton exchange membrane electrolyzer 13 through the fourth branch pipe 17, and the cathode water outlet of the third proton exchange membrane electrolyzer 13 is connected to the fourth end 312. By arranging multiple proton exchange membrane electrolyzers, the production efficiency of the electrolytic water system based on the proton exchange membrane is improved.

[0042] Optionally, a first control valve is provided on the first branch pipe 14, the first branch pipe 14 is connected to the second end 212 through a first connecting pipe 19.1, and the connection between the first connecting pipe 19.1 and the first branch pipe 14 is located between the anode water outlet of the first proton exchange membrane electrolyzer 11 and the first control valve, and a second control valve 18.2 is provided on the first connecting pipe 19.1; a third control valve 18.3 is provided on the second branch pipe 15, the second branch pipe 15 is connected to the second end 212 through the second connecting pipe 19.2, and the connection between the second connecting pipe 19.2 and the second branch pipe 15 is located between the anode water outlet of the second proton exchange membrane electrolyzer 12 and the third control valve 18.3, and a fourth control valve 18.4 is provided on the second connecting pipe 19.2; the anode water outlet of the third proton exchange membrane electrolyzer 13 is connected to the second end 212 through the third connecting pipe 19.3, and a fifth control valve 18.5 is provided on the third connecting pipe 19.3; A sixth control valve 18.6 is provided on the branch pipe 16, the third branch pipe 16 is connected to the third end 311 through a fourth connecting pipe 19.4, and the connection between the fourth connecting pipe 19.4 and the third branch pipe 16 is located between the cathode water outlet of the first proton exchange membrane electrolyzer 11 and the sixth control valve 18.6, and a seventh control valve 18.7 is provided on the fourth connecting pipe 19.4; an eighth control valve 18.8 is provided on the fourth branch pipe 17, the fourth branch pipe 17 is connected to the fourth end 312 through a fifth connecting pipe 19.5, and the connection between the fifth connecting pipe 19.5 and the fourth branch pipe 17 is located between the cathode water outlet of the second proton exchange membrane electrolyzer 12 and the eighth control valve 18.8, and a ninth control valve 18.9 is provided on the fifth connecting pipe 19.5; the cathode water outlet of the third proton exchange membrane electrolyzer 13 is connected to the fourth end 312 through a sixth connecting pipe 19.6, and a tenth control valve 18.10 is provided on the sixth connecting pipe 19.6.

[0043] For example, when the electricity consumption is at a peak period, in order to reduce the electricity consumption of the proton exchange membrane-based water electrolysis system, it is necessary to convert it into low-power water electrolysis hydrogen production. At this time, it is only necessary to start the operation of the first proton exchange membrane electrolyzer 11, that is, open the second control valve 18.2 and the seventh control valve 18.7, close the first control valve 18.1, the third control valve 18.3, the fourth control valve 18.4, the fifth control valve 18.5, the sixth control valve 18.6, the eighth control valve 18.8, the ninth control valve 18.9 and the tenth control valve 18.10, so that the anode solution containing oxygen flowing out of the anode outlet of the first proton exchange membrane electrolyzer 11 flows back to the first connecting pipe 21 through the first branch pipe 14 and the first connecting pipe 19.1, and at the same time, the cathode solution containing hydrogen flowing out of the cathode outlet of the first proton exchange membrane electrolyzer 11 flows back to the second connecting pipe 31 from the third branch pipe 16 and the fourth connecting pipe 19.4;

[0044] When the power consumption is in a slow period, it is necessary to convert to medium power water electrolysis to produce hydrogen. At this time, the first proton exchange membrane electrolyzer 11 and the second proton exchange membrane electrolyzer 12 need to be started to operate, that is, the first control valve 18.1, the fourth control valve 18.4, the sixth control valve 18.6 and the ninth control valve 18.9 are opened, and the second control valve 18.2, the third control valve 18.3, the fifth control valve 18.5, the seventh control valve 18.7, the eighth control valve 18.8 and the tenth control valve 18.10 are closed, so that the anode solution containing oxygen flowing out of the anode outlet of the first proton exchange membrane electrolyzer 11 flows to the second proton exchange membrane electrolyzer 12 through the first branch pipe 14. The cathode water solution containing hydrogen flowing out of the cathode water outlet of the first proton exchange membrane electrolyzer 11 flows to the cathode water inlet of the second proton exchange membrane electrolyzer 12 through the third branch pipe 16, and after reacting in the second proton exchange membrane electrolyzer 12, flows back to the second connecting pipe 31 from the cathode water outlet of the second proton exchange membrane electrolyzer 12 through the fourth branch pipe 17 and the fifth connecting pipe 19.5;

[0045] When the electricity consumption is low, the proton exchange membrane-based water electrolysis system can use excess electricity to electrolyze water to produce more hydrogen and oxygen. At this time, the first proton exchange membrane electrolyzer 11, the second proton exchange membrane electrolyzer 12 and the third proton exchange membrane electrolyzer 13 are all involved in the operation, that is, the first control valve 18.1, the third control valve 18.3, the fifth control valve 18.5, the sixth control valve 18.6, the eighth control valve 18.8 and the tenth control valve 18.10 are opened, and the second control valve 18.2, the fourth control valve 18.4, the seventh control valve 18.7 and the ninth control valve 18.9 are closed, so that the anode solution containing oxygen flowing out of the anode outlet of the first proton exchange membrane electrolyzer 11 flows to the anode inlet of the second proton exchange membrane electrolyzer 12 through the first branch pipe 14, and the anode solution containing oxygen flowing out of the anode outlet of the second proton exchange membrane electrolyzer 12 after the reaction in the second proton exchange membrane electrolyzer 12 The anode solution containing oxygen flows to the anode water inlet of the third proton exchange membrane electrolyzer 13 through the second branch pipe 15, and flows out from the anode water outlet of the third proton exchange membrane electrolyzer 13 after reacting in the third proton exchange membrane electrolyzer 13, and flows back to the first connecting pipe 21 through the third connecting pipe 19.3; at the same time, the cathode solution containing hydrogen flowing out from the cathode water outlet of the first proton exchange membrane electrolyzer 11 flows to the cathode water inlet of the second proton exchange membrane electrolyzer 12 through the third branch pipe 16, and flows out from the cathode water outlet of the second proton exchange membrane electrolyzer 12 after reacting in the second proton exchange membrane electrolyzer 12 through the fourth branch pipe 17. The cathode solution containing hydrogen flowing out from the cathode water outlet of the third proton exchange membrane electrolyzer 13 after reacting in the third proton exchange membrane electrolyzer 13 flows back to the second connecting pipe 31 through the sixth connecting pipe 19.6. By controlling the connection or closing of the pipelines of multiple proton exchange membrane electrolyzers connected in series through a controller, the production needs of the water electrolysis system under different conditions can be adapted, the resource utilization rate can be improved, and the adaptability of the water electrolysis system under renewable energy power generation conditions can be enhanced. By connecting multiple proton exchange membrane electrolyzers in series, the number of entanglements of components in the system and the complexity of the cycle can be reduced, thereby improving the robustness of the water electrolysis system.

[0046] In addition, the cell group 1 is not limited to having three proton exchange membrane electrolyzers, namely the first proton exchange membrane electrolyzer 11, the second proton exchange membrane electrolyzer 12 and the third proton exchange membrane electrolyzer 13, but may also have 4, 5, 6, 7 or more proton exchange membrane electrolyzers connected in series.

[0047] In some embodiments, the cell group 1 further includes a buffer tank 20, and a buffer tank 20 is provided at the connection between each branch pipe and the connecting pipe. By providing the buffer tank 20, when the number of multiple proton exchange membrane electrolyzers is switched, the gas-containing solution flowing through the branch pipe can be effectively buffered, and the start and stop of each control valve can be assisted to avoid the situation where the pressure in the branch pipe increases sharply due to the closure of some control valves, resulting in rupture or explosion. For example, the first branch pipe 14 is provided with a buffer tank 20, and the first connecting pipe 19.1 is connected to the buffer tank 20.

[0048] Furthermore, the oxygen separation unit includes an anode gas-liquid separator 231, an oxygen pipe 232, an oxygen dryer 233 and an oxygen control valve 234. The anode gas-liquid separator 231 is arranged on the first connecting pipe 21, the oxygen pipe 232 is connected to the anode gas-liquid separator 231, and the oxygen pipe 232 is provided with an oxygen dryer 233 and an oxygen control valve 234. The oxygen is dried by the oxygen dryer 233 for subsequent storage and safe use, and the oxygen control valve 234 is used to control the discharge of oxygen; the hydrogen separation unit 33 includes a cathode gas-liquid separator The cathode gas-liquid separator 331 is arranged on the second connecting pipe 31, and the two ends of the hydrogen pipe 332 are respectively connected to the cathode gas-liquid separator 331 and the hydrogen storage tank. The hydrogen pipe 332 is provided with a hydrogen dryer 333 and a hydrogen control valve 334. The hydrogen dryer 333 is used to dry oxygen for subsequent storage and safe use. The hydrogen control valve 334 is used to control the discharge rate of hydrogen to the hydrogen tank 335 to ensure the safe use of the hydrogen tank 335.

[0049] Optionally, liquid level sensors are provided in the anode gas-liquid separator 231 and the cathode gas-liquid separator 331. The liquid level sensors are used to determine whether the water level in the gas-liquid separator is lower than the liquid level sensors. When the water level in the gas-liquid separator is lower than the liquid level sensors, the solution in the corresponding pipeline needs to be replenished.

[0050] Specifically, the anode circulation system 2 also includes an anode water replenishment unit 25, which includes an anode water replenishment jet pump 251, an anode water replenishment pipe 252, an anode water replenishment check valve 253 and an anode water replenishment control valve 254. The anode water replenishment jet pump 251 is arranged on the first connecting pipe 21, and the two ends of the anode water replenishment pipe 252 are respectively connected to the anode water replenishment jet pump 251 and the water replenishment tank, and the anode water replenishment pipe 252 is provided with an anode water replenishment check valve 253 and an anode water replenishment control valve 254; In this embodiment, the anode water replenishment jet pump 251 is arranged between the second end 212 and the anode gas-liquid separator 231, that is, the anode water outlet of the cell group 1 discharges the high-pressure anode solution mixed with oxygen into the anode water replenishment jet pump 251, so that a negative pressure is formed in the anode water replenishment jet pump 251. At this time, the anode solution in the water replenishment tank is sucked into the pump by the anode water replenishment jet pump 251 under the action of the negative pressure and mixed with the high-pressure anode solution, and then flows to the anode gas-liquid separator 231 for gas-liquid separation;

[0051] Similarly, the cathode circulation system 3 also includes a cathode water replenishment unit 35, which includes a cathode water replenishment jet pump 351, a cathode water replenishment pipe 352, a cathode water replenishment check valve 353 and a cathode water replenishment control valve 354. The cathode water replenishment jet pump 351 is arranged on the second connecting pipe 31, and the two ends of the cathode water replenishment pipe 352 are respectively connected to the cathode water replenishment jet pump 351 and the water replenishment tank. The cathode water replenishment pipe 352 is provided with a cathode water replenishment check valve 353 and a cathode water replenishment control valve 354. In this embodiment, the cathode water replenishment jet pump 351 is arranged between the fourth end 312 and the cathode gas-liquid separator 331, that is, the cathode water outlet of the cell group 1 discharges the mixed hydrogen The high-pressure cathode solution of the gas enters the cathode water replenishment jet pump 351, so that a negative pressure is formed in the cathode water replenishment jet pump 351. At this time, the cathode solution in the water replenishment tank is sucked into the pump by the cathode water replenishment jet pump 351 under the action of negative pressure and mixed with the high-pressure cathode solution, and then flows to the cathode gas-liquid separator 331 for gas-liquid separation; the anode water replenishment jet pump 251 and the cathode water replenishment jet pump 351 use the pressure generated by the proton exchange membrane electrolyzer to replenish water, and there is no need to set up an additional water pump for driving, thereby reducing the energy consumption of the water replenishment unit; and the setting of the one-way valve can prevent the solution in the connecting pipe from flowing back to the water replenishment tank, thereby ensuring the operating stability of the electrolytic water system.

[0052] It is worth noting that the anode water replenishment jet pump 251 and the cathode water replenishment jet pump 351 are both fluid power pumps, that is, they have no mechanical transmission and mechanical working components, and use the energy of the working fluid as a power source to transport low-energy liquid. In this embodiment, the anode solution and the cathode solution are both deionized water, so the anode water replenishment pipe 252 and the cathode water replenishment pipe 352 can share a water replenishment tank.

[0053] In addition, the anode water replenishment jet pump 251 and the cathode water replenishment jet pump 351 can also use other self-driven power pumps, which can be set at other positions of the connecting pipe. At the same time, the anode water replenishment pipe 252 and the cathode water replenishment pipe 352 can also use independent water replenishment tanks respectively.

[0054] Furthermore, the anode cooling unit 24 includes an anode heat exchanger 241, an anode radiator 242 and an anode coolant circulation pump 243. The anode heat exchanger 241 is arranged on the first connecting pipe 21. The inner cavity of the anode heat exchanger 241 has a coolant. The inner cavity of the anode radiator 242 is communicated with the inner cavity of the anode heat exchanger 241. The anode coolant circulation pump 243 is arranged between the anode heat exchanger 241 and the anode radiator 242. The coolant in the inner cavity of the anode heat exchanger 241 can perform heat exchange with the anode solution flowing in the first connecting pipe 21. The coolant after heat exchange is driven to the inner cavity of the anode heat exchanger 241 by the anode coolant circulation pump 243. In this embodiment, the anode heat exchanger 241 is a tube-fin radiator and a fan integrated product, which can perform heat exchange between the coolant in the inner cavity of the anode heat exchanger 241 and the air, so as to avoid the temperature of the recycled anode solution being too high and affecting the electrolysis efficiency of the cell group 1, thereby ensuring the service life and use stability of the cell group 1.

[0055] Similarly, the cathode cooling unit 34 includes a cathode heat exchanger 341, a cathode radiator 342 and a cathode coolant circulation pump 343. The cathode heat exchanger 341 is arranged on the second connecting pipe 31. The inner cavity of the cathode heat exchanger 341 has coolant. The inner cavity of the cathode radiator 342 is connected to the inner cavity of the cathode heat exchanger 341. The cathode coolant circulation pump 343 is arranged between the cathode heat exchanger 341 and the cathode radiator 342. The coolant in the inner cavity of the cathode heat exchanger 341 can exchange heat with the cathode solution flowing in the second connecting pipe 31. The coolant after heat exchange is driven to the inner cavity of the cathode heat exchanger 341 by the cathode coolant circulation pump 343. In this embodiment, the cathode heat exchanger 341 is a tube-fin radiator and a fan integrated product, which can exchange heat between the coolant in the inner cavity of the cathode heat exchanger 341 and the air, so as to avoid the temperature of the recycled cathode solution being too high and affecting the electrolysis efficiency of the cell group 1, thereby ensuring the service life and stability of the cell group 1.

[0056] In other embodiments, the anode circulation system 2 further includes an anode filter unit 26, the anode filter unit 26 includes an anode filter 261 and an anode deionizer 262 disposed on the first connecting pipe 21, and the anode deionizer 262 is located between the anode filter 261 and the anode water inlet of the cell group 1, the anode filter 261 can filter particles peeled off during the operation of each process component in the anode circulation system 2, and the anode deionizer 262 can remove various ions formed by the anode solution in the operation of each process of the anode circulation system 2;

[0057] The cathode circulation system 3 also includes a cathode filter unit 36, which includes a cathode filter 361 and a cathode deionizer 362 arranged on the second connecting pipe 31, and the cathode deionizer 362 is located between the cathode filter 361 and the cathode water inlet of the cell group 1. The cathode filter 361 can filter particles peeled off during the operation of each process component in the cathode circulation system 3, and the cathode deionizer 362 can remove various ions formed in the cathode solution during the operation of each process of the cathode circulation system 3. The setting of the filter unit can improve the water quality entering the cell group 1, ensure the electrolysis efficiency of the cell group 1 and the service life of the cell group 1.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A water electrolysis system based on a proton exchange membrane, characterized in that: include: An electric cell group, the electric cell group having an anode water inlet, an anode water outlet, a cathode water inlet and a cathode water outlet, the anode water outlet is used to discharge an anode solution mixed with oxygen, and the cathode water outlet is used to discharge a cathode solution mixed with hydrogen; An anode circulation system, the anode circulation system comprising a first connecting pipe, the two ends of the first connecting pipe are respectively connected to the anode water inlet and the anode water outlet, the first connecting pipe is provided with a first pump body, an oxygen separation unit and an anode cooling unit, the oxygen separation unit is capable of separating the oxygen and the anode solution, and the anode cooling unit is capable of cooling the anode solution in the first connecting pipe; A cathode circulation system, the cathode circulation system comprises a second connecting pipe, the two ends of the second connecting pipe are respectively connected to the cathode water inlet and the cathode water outlet, the second connecting pipe is provided with a second pump body, a hydrogen separation unit and a cathode cooling unit, the hydrogen separation unit can separate the hydrogen and the cathode solution, the cathode cooling unit can cool the cathode solution in the second connecting pipe.

2. The proton exchange membrane-based water electrolysis system according to claim 1, characterized in that: The electrolyzer group includes at least two proton exchange membrane electrolyzers connected in series.

3. The proton exchange membrane-based water electrolysis system according to claim 2, characterized in that: The cell group includes a first proton exchange membrane electrolyzer, a second proton exchange membrane electrolyzer and a third proton exchange membrane electrolyzer, and each proton exchange membrane electrolyzer is provided with the anode water inlet, the anode water outlet, the cathode water inlet and the cathode water outlet, the first connecting pipe has a first end and a second end opposite to each other, the first end is connected to the anode water inlet of the first proton exchange membrane electrolyzer, the anode water outlet of the first proton exchange membrane electrolyzer is connected to the anode water inlet of the second proton exchange membrane electrolyzer through a first branch pipe, the anode water outlet of the second proton exchange membrane electrolyzer is connected to the anode water inlet of the third proton exchange membrane electrolyzer through a second branch pipe, and the anode water outlet of the third proton exchange membrane electrolyzer is connected to the second end; The second connecting pipe has a third end and a fourth end opposite to each other, the third end is connected to the cathode water inlet of the first proton exchange membrane electrolyzer, the cathode water outlet of the first proton exchange membrane electrolyzer is connected to the cathode water inlet of the second proton exchange membrane electrolyzer through a third branch pipe, the cathode water outlet of the second proton exchange membrane electrolyzer is connected to the cathode water inlet of the third proton exchange membrane electrolyzer through a fourth branch pipe, and the cathode water outlet of the third proton exchange membrane electrolyzer is connected to the fourth end.

4. The proton exchange membrane-based water electrolysis system according to claim 3, characterized in that: The first branch pipe is provided with a first control valve, the first branch pipe is connected to the second end through a first connecting pipe, and the connection between the first connecting pipe and the first branch pipe is located between the anode water outlet of the first proton exchange membrane electrolyzer and the first control valve, and the first connecting pipe is provided with a second control valve; The second branch pipe is provided with a third control valve, the second branch pipe is connected to the second end through a second connecting pipe, and the connection between the second connecting pipe and the second branch pipe is located between the anode water outlet of the second proton exchange membrane electrolyzer and the third control valve, and the second connecting pipe is provided with a fourth control valve; The anode water outlet of the third proton exchange membrane electrolyzer is connected to the second end through a third connecting pipe, and a fifth control valve is provided on the third connecting pipe; The third branch pipe is provided with a sixth control valve, the third branch pipe is connected to the third end through a fourth connecting pipe, and the connection between the fourth connecting pipe and the third branch pipe is located between the cathode water outlet of the first proton exchange membrane electrolyzer and the sixth control valve, and the fourth connecting pipe is provided with a seventh control valve; The fourth branch pipe is provided with an eighth control valve, the fourth branch pipe is connected to the fourth end through a fifth connecting pipe, and the connection between the fifth connecting pipe and the fourth branch pipe is located between the cathode water outlet of the second proton exchange membrane electrolyzer and the eighth control valve, and the fifth connecting pipe is provided with a ninth control valve; The cathode water outlet of the third proton exchange membrane electrolyzer is connected to the fourth end through a sixth connecting pipe, and a tenth control valve is provided on the sixth connecting pipe.

5. The proton exchange membrane-based water electrolysis system according to claim 4, characterized in that: The battery cell group further includes a buffer tank, and the buffer tank is provided at the connection between each branch pipe and the connecting pipe.

6. The proton exchange membrane-based water electrolysis system according to any one of claims 1 to 5, characterized in that: The oxygen separation unit comprises an anode gas-liquid separator, an oxygen pipe, an oxygen dryer and an oxygen control valve, wherein the anode gas-liquid separator is arranged on the first connecting pipe, the oxygen pipe is connected to the anode gas-liquid separator, and the oxygen dryer and the oxygen control valve are arranged on the oxygen pipe; The hydrogen separation unit includes a cathode gas-liquid separator, a hydrogen pipe, a hydrogen dryer, a hydrogen control valve and a hydrogen storage tank. The cathode gas-liquid separator is arranged on the second connecting pipe, and the two ends of the hydrogen pipe are respectively connected to the cathode gas-liquid separator and the hydrogen storage tank. The hydrogen dryer and the hydrogen control valve are arranged on the hydrogen pipe.

7. The proton exchange membrane-based water electrolysis system according to claim 6, characterized in that: Liquid level sensors are provided in both the anode gas-liquid separator and the cathode gas-liquid separator.

8. The proton exchange membrane-based water electrolysis system according to claim 7, characterized in that: The anode circulation system further includes an anode water replenishment unit, which includes an anode water replenishment jet pump, an anode water replenishment pipe, an anode water replenishment check valve and an anode water replenishment control valve. The anode water replenishment jet pump is arranged on the first connecting pipe, and the two ends of the anode water replenishment pipe are respectively connected to the anode water replenishment jet pump and the water replenishment tank, and the anode water replenishment pipe is provided with the anode water replenishment check valve and the anode water replenishment control valve; and / or, The cathode circulation system also includes a cathode water replenishment unit, which includes a cathode water replenishment jet pump, a cathode water replenishment pipe, a cathode water replenishment one-way valve and a cathode water replenishment control valve. The cathode water replenishment jet pump is arranged on the second connecting pipe, and the two ends of the cathode water replenishment pipe are respectively connected to the cathode water replenishment jet pump and the water replenishment tank, and the cathode water replenishment pipe is provided with the cathode water replenishment one-way valve and the cathode water replenishment control valve.

9. The proton exchange membrane-based water electrolysis system according to any one of claims 1 to 5, characterized in that: The anode cooling unit comprises an anode heat exchanger, an anode radiator and an anode coolant circulation pump, wherein the anode heat exchanger is arranged on the first connecting pipe, the inner cavity of the anode heat exchanger has coolant, the inner cavity of the anode radiator is communicated with the inner cavity of the anode heat exchanger, and the anode coolant circulation pump is arranged between the anode heat exchanger and the anode radiator; The cathode cooling unit includes a cathode heat exchanger, a cathode radiator and a cathode coolant circulation pump. The cathode heat exchanger is arranged on the second connecting pipe. The inner cavity of the cathode heat exchanger has coolant. The inner cavity of the cathode radiator is communicated with the inner cavity of the cathode heat exchanger. The cathode coolant circulation pump is arranged between the cathode heat exchanger and the cathode radiator.

10. The proton exchange membrane-based water electrolysis system according to any one of claims 1 to 5, characterized in that: The anode circulation system further comprises an anode filter unit, wherein the anode filter unit comprises an anode filter and an anode deionizer arranged on the first connecting pipe, and the anode deionizer is located between the anode filter and the anode water inlet of the cell group; The cathode circulation system further comprises a cathode filter unit, which comprises a cathode filter and a cathode deionizer arranged on the second connecting pipe, and the cathode deionizer is located between the cathode filter and the cathode water inlet of the cell group.

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