Square electrolytic cell suitable for wind-solar coupling hydrogen production and flexible hydrogen production method

Abstract

The invention relates to the technical field of water electrolysis hydrogen production, and discloses a square electrolytic cell suitable for wind-solar coupling hydrogen production and a flexible hydrogen production method, the square electrolytic cell comprises an end cathode cell, a unit cell, an end anode cell and an extruder which are stacked, and a diaphragm body, a cathode gasket and an anode gasket are arranged between adjacent cell bodies. A membrane polar distance structure is formed in the unit tank through cooperation of an elastic buffer net and an extruding machine in a pressing mode, circulating plates are arranged on the cathode side and the anode side respectively and form a circulating flow channel with a bent base plate, and a bubble breaking net of an outlet assembly conducts bubble breaking and pre-separation on a gas-liquid mixture. The hydrogen production method comprises the steps of assembling and pressing, electrolysis gas production, unit tank pre-separation, system separation and collection and alkali liquor constant-pressure circulating supply. Mass transfer resistance is reduced through a membrane polar distance structure, gas is accelerated to be separated from the surface of an electrode through a circulating flow channel, the load of a rear-end separator is reduced through gas-liquid pre-separation, the flexible hydrogen production process is accurately matched with the fluctuation characteristic of wind and light power generation current, the problem that a traditional electrolytic cell is poor in adaptability is solved, and the stability and high efficiency of a hydrogen production system are improved.

Description

Technical Field

[0001] This invention relates to the field of water electrolysis hydrogen production technology, specifically to a square electrolyzer and a flexible hydrogen production method suitable for wind-solar coupled hydrogen production. Background Technology

[0002] In alkaline water electrolysis for hydrogen production, the wind-solar coupled hydrogen production mode is gradually becoming a development direction due to its alignment with the demand for green electricity consumption. Traditional alkaline electrolyzers mostly adopt circular or square internal flow channel structures. These electrolyzers typically rely on screw fastening for sealing and lack efficient alkaline solution circulation channels and gas-liquid pre-separation designs. The distance between the electrodes and the diaphragm is difficult to control stably, resulting in relatively high mass transfer resistance. In actual operation, the gas generated on the electrode surface is not easy to escape quickly and tends to accumulate, forming gas resistance.

[0003] Wind-solar coupled power generation is affected by natural conditions, resulting in second-level fluctuations in output current. These fluctuations directly cause sudden changes in gas production from the electrolyzer. Furthermore, structural defects in traditional electrolyzers exacerbate gas resistance issues, not only reducing electrolysis efficiency but also potentially leading to malfunctions such as dry burning, making them unsuitable for the operational requirements of wind-solar coupled hydrogen production. Therefore, there is an urgent need to develop an electrolyzer and hydrogen production method that can adapt to the characteristics of current fluctuations. This can be achieved by optimizing the internal structure to reduce mass transfer resistance, promote alkali circulation and gas-liquid separation, and thus adapt to the wind-solar coupled hydrogen production scenario. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a square electrolyzer and a flexible hydrogen production method suitable for wind-solar coupled hydrogen production, solving the technical problem that traditional alkaline electrolyzers, due to their high mass transfer resistance and low gas-liquid separation efficiency, are difficult to adapt to the current fluctuations of wind-solar coupled power generation.

[0005] In a first aspect, the present invention provides the following technical solution: a square electrolyzer suitable for wind-solar coupled hydrogen production, comprising an end cathode cell, at least one unit cell, and an end anode cell stacked sequentially along the electrolysis direction, and an extruder for pressing and fixing each cell; a diaphragm body, a cathode gasket, and an anode gasket are provided between adjacent cells; the unit cell includes a four-sided frame body, a bending base, an inlet assembly, an outlet assembly, and a gas-liquid box assembly; its interior is divided into a cathode side and an anode side by the diaphragm body; a cathode mesh is provided on the cathode side, and a cathode mesh is sandwiched between the diaphragm body and the diaphragm body. An elastic buffer net is provided, with a cathode bottom net on the side opposite to the diaphragm body; an anode net is provided on the anode side; the pressing force provided by the extruder compresses the elastic buffer net, thereby causing the cathode net and the anode net to adhere tightly to the diaphragm body, forming a membrane electrode distance structure; a cathode circulation plate and an anode circulation plate are also provided on the cathode side and the anode side respectively, and a flow channel for promoting the internal circulation of the alkali solution is formed between the cathode circulation plate and the anode circulation plate and the bending base; the outlet assembly includes a defoaming net for defoaming the gas-liquid mixture from the electrode net to achieve gas-liquid pre-separation.

[0006] Preferably, the compression of the elastic buffer net is 50% to 58% of its free height.

[0007] Preferably, the outlet assembly further includes a gas-liquid rectangular tube, a support plate, and a separation plate; the defoaming mesh is disposed in the flow channel of the gas-liquid rectangular tube, and the separation plate divides the inner cavity of the outlet assembly into an upper gas chamber and a lower liquid chamber, wherein the cross-sectional area ratio of the gas chamber to the liquid chamber is 1 to 2.

[0008] Preferably, the cathode side and the anode side are respectively provided with a cathode conductive support tube and an anode conductive support tube, and both the cathode conductive support tube and the anode conductive support tube are trapezoidal tube structures.

[0009] Preferably, the extruder includes an end fixed seat, a movable seat, a hydraulic cylinder for driving the movable seat, a locking screw, and a guide rail; the unit slot, the end cathode slot, and the end anode slot are all provided with handle brackets, and the handle brackets are supported on the guide rails for positioning.

[0010] Preferably, both the end cathode groove and the end anode groove include an end four-sided frame, a conductive plate, a support grid, a back plate, an inlet assembly, an outlet assembly, a gas-liquid box assembly, a bending chassis, and a handle bracket.

[0011] Secondly, the present invention provides the following technical solution: a flexible hydrogen production method suitable for wind-solar coupled hydrogen production, comprising the following steps:

[0012] S1. Assembly and pressing: The insulating plate, end cathode groove, cathode gasket, diaphragm body, anode gasket, at least one unit groove and end anode groove are placed in sequence between the end fixed seat and the movable seat of the extruder. The movable seat is pushed by the hydraulic cylinder to press each component, so that the elastic buffer net in the unit groove is compressed to form the membrane electrode distance structure.

[0013] S2. Electrolysis Gas Generation: The assembled square electrolytic cell is fed with imported alkaline solution and electrolyzed. The anode grid produces oxygen and the cathode grid produces hydrogen. The generated gas drives the alkaline solution to flow, forming a circulating alkaline solution and eventually forming a gas-liquid mixture.

[0014] S3. Pre-separation in unit tank: The gas-liquid mixture enters the outlet component of the unit tank, and after the bubble is broken by the bubble-breaking net, gas-liquid pre-separation is achieved. The separated gas and alkaline solution are discharged in a stratified form through the gas-liquid box component.

[0015] S4. System Separation and Alkali Collection: The gas-liquid mixture discharged from the cathode side is passed into a hydrogen separator for gas-liquid separation. The separated hydrogen is cooled by a hydrogen heat exchanger and washed by a hydrogen scrubber before being discharged. The gas-liquid mixture discharged from the anode side is passed into an oxygen separator for gas-liquid separation. The separated oxygen is cooled and washed before being discharged. The alkali returned from the hydrogen separator, oxygen separator, and scrubbing equipment is collected into a common buffer tank.

[0016] S5. Alkali solution constant pressure circulation supply: The alkali solution in the buffer tank is transported to the diaphragm-type pressure-maintaining alkali tank by a shielded pump; nitrogen gas at a constant pressure is introduced into the nitrogen chamber of the diaphragm-type pressure-maintaining alkali tank to supply the alkali solution back to the square electrolytic cell.

[0017] Preferably, the buffer tank is provided with a partition, which divides the tank into two parts corresponding to the cathode side and the anode side respectively, and the bottom of the partition is provided with a connecting structure.

[0018] Preferably, in step S4, the gas-liquid mixture passes through ball valves before entering the hydrogen separator and oxygen separator. The separated hydrogen is discharged after being detected by a hydrogen-oxygen analyzer, and the separated oxygen is discharged after being detected by an oxygen-hydrogen analyzer. The washing water for the hydrogen scrubber and oxygen scrubber is supplied by a water tank through a water pump. The flow rates of the discharged hydrogen and oxygen are regulated by the hydrogen pneumatic diaphragm regulating valve and the oxygen pneumatic diaphragm regulating valve, respectively.

[0019] Preferably, in step S5, the shielded pump delivers the alkali solution to the heat exchanger body for temperature regulation, and then sends it to the diaphragm-type pressure-maintaining alkali tank; the flow rate of the alkali solution supplied back to the square electrolytic cell is regulated by the alkali solution pneumatic diaphragm regulating valve.

[0020] This invention provides a square electrolyzer and a flexible hydrogen production method suitable for wind-solar coupled hydrogen production. It offers the following advantages:

[0021] 1. This invention reduces the mass transfer resistance between the anode and cathode by setting up an elastic buffer net and pressing it with an extruder to form a membrane electrode distance structure. At the same time, it uses the cathode circulation plate and anode circulation plate to form a flow channel with the bending chassis to promote the circulation of alkaline solution. Then, the gas-liquid pre-separation is achieved through the bubble-breaking net of the outlet component, which accelerates the gas from leaving the electrode surface and effectively adapts to the current fluctuation characteristics of wind-solar coupled power generation.

[0022] 2. This invention uses the hydraulic cylinder of the extruder to push the movable seat to move along the guide rail, and with the help of the end fixing seat, it achieves uniform pressing of each tank. The handle bracket accurately positions each tank, and the locking screw maintains stable pressing force, which improves the assembly accuracy of the electrolytic cell, simplifies the disassembly and assembly process, reduces the difficulty of later maintenance, and ensures long-term stable operation of the equipment.

[0023] 3. The present invention adopts a component structure that matches the unit cell for the end cathode cell and end anode cell, ensuring that the fluid channels of the end cell and the unit cell are connected end to end. At the same time, the conductive plate and the supporting grid are used to conduct current evenly, improve the interchangeability of the components of the end cell and the unit cell, and maintain the stability of the electrolysis reaction.

[0024] 4. In this invention, the buffer tank partition in the flexible hydrogen production method isolates the anode and cathode alkaline solutions and achieves bottom-to-bottom mixing. The alkaline solution is then delivered by a shielded pump. Combined with the constant nitrogen pressure supply of the diaphragm-type pressure-maintaining alkaline tank, the alkaline solution is flexibly matched to the alkaline solution requirements of the electrolyzer, avoiding backflow problems caused by current fluctuations and ensuring the stable operation of the hydrogen production system. Attached Figure Description

[0025] Figure 1 A perspective view provided for this invention;

[0026] Figure 2 A schematic diagram of the square unit groove for the outer flow channel provided by the present invention;

[0027] Figure 3 A schematic diagram of the membrane electrode distance structure provided by the present invention;

[0028] Figure 4 A schematic diagram of the membrane electrode distance structure provided by the present invention;

[0029] Figure 5 This is a schematic diagram of the internal circulation of the alkali solution provided by the present invention;

[0030] Figure 6 A schematic diagram of the export component provided by the present invention;

[0031] Figure 7 A schematic diagram of the end electrode groove provided by the present invention;

[0032] Figure 8 A flow chart of a flexible hydrogen production process provided by the present invention;

[0033] Figure 9 A schematic diagram of the oxygen separator provided by the present invention;

[0034] Figure 10 A schematic diagram of the buffer tank provided by the present invention;

[0035] Figure 11 This is a schematic diagram of the diaphragm-type pressure-maintaining alkali tank provided by the present invention.

[0036] The components include: 1. Electrolytic cell; 2. Ball valve; 3. Hydrogen separator; 4. Oxygen separator; 5. Hydrogen heat exchanger; 6. Oxygen heat exchanger; 7. Hydrogen scrubber; 8. Oxygen scrubber; 9. Hydrogen pneumatic diaphragm regulating valve; 10. Oxygen pneumatic diaphragm regulating valve; 11. Hydrogen-oxygen analyzer; 12. Oxygen-hydrogen analyzer; 13. Alkali pneumatic diaphragm regulating valve; 14. Buffer tank; 15. Shielded pump; 16. Heat exchanger body; 17. Diaphragm-type pressure-maintaining alkali tank; 18. Water tank; 19. Water pump; 100. Unit tank; 20. End cathode tank; 30. End anode tank; 40. Cathode gasket; 50. Diaphragm body; 60. Anode gasket; 70. Insulating plate; 80. Extruder; 801. Hydraulic cylinder; 802. Movable seat; 803. Locking screw; 804. End fixed seat; 805. Guide rail. 101. Anode mesh; 102. Anode conductive support tube; 103. Inlet component; 104. Outlet component; 105. Gas-liquid box component; 106. Four-sided frame body; 107. Bending chassis; 108. Cathode conductive support tube; 109. Cathode circulation plate; 1010. Cathode bottom mesh; 1011. Elastic buffer mesh; 1012. Cathode mesh; 1013. Anode circulation plate; 1014. Handle bracket; 10401. Bubble-breaking mesh; 10402. Support plate; 10403. Separation plate; 10404. Gas-liquid rectangular tube; 201. End four-sided frame; 202. Conductive plate; 203. Support grid; 204. Back plate; A1. Inlet alkali solution; A2. Oxygen generated by electrolysis; A3. Gas-liquid mixture; A4. Circulating alkali solution; A5. Oxygen; A6. Alkali solution; B1. Hydrogen; C1. Nitrogen. Detailed Implementation

[0037] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1: Please refer to the appendix Figure 1 -Appendix Figure 7This invention provides a square electrolyzer and a flexible hydrogen production method suitable for wind-solar coupled hydrogen production. The method includes an end cathode cell 20, at least one unit cell 100, and an end anode cell 30 stacked sequentially along the electrolysis direction, as well as a press 80 for pressing and fixing each cell. A diaphragm body 50, a cathode gasket 40, and an anode gasket 60 are provided between adjacent cells. The unit cell 100 includes a four-sided frame body 106, a bending base 107, an inlet assembly 103, an outlet assembly 104, and a gas-liquid box assembly 105. Its interior is divided into a cathode side and an anode side by the diaphragm body 50. A cathode mesh 1012 is provided on the cathode side, and an elastic buffer is sandwiched between the cathode mesh 1012 and the diaphragm body 50. The elastic buffer mesh 1011 has a cathode bottom mesh 1010 on the side opposite to the diaphragm body 50; the anode mesh 101 is provided on the anode side; the pressing force provided by the extruder 80 compresses the elastic buffer mesh 1011, thereby making the cathode mesh 1012 and the anode mesh 101 adhere tightly to the diaphragm body 50 to form a membrane electrode distance structure; the cathode side and the anode side are also provided with a cathode circulation plate 109 and an anode circulation plate 1013 respectively, and a flow channel for promoting the internal circulation of alkali solution is formed between the cathode circulation plate 109 and the anode circulation plate 1013 and the bending chassis 107; the outlet assembly 104 includes a defoaming mesh 10401 for defoaming the gas-liquid mixture A3 from the electrode mesh to achieve gas-liquid pre-separation.

[0039] Specifically, the end cathode tank 20 and end anode tank 30 form the beginning and end electrode regions of the electrolysis reaction, defining the electrolysis interval and conducting external current, thereby ensuring uniform current input to each unit tank 100 and providing the basic conditions for stable hydrogen production. The extruder 80 applies continuous and uniform clamping force, fixing the overall structure of the end cathode tank 20, unit tank 100, and end anode tank 30, ensuring a tight seal between the tanks and providing the necessary pressure for the formation of the membrane electrode distance structure. The diaphragm body 50 separates the cathode and anode sides of the unit tank 100, preventing the mixing of hydrogen and oxygen and conducting the ions required for electrolysis, thus ensuring the safe and orderly conduction of the electrolysis reaction. The cathode gasket 40 and anode gasket 60 fill the gaps between adjacent tanks, preventing alkali leakage and gas leakage, thereby improving the safety and stability of equipment operation. The frame structure of the unit tank 100 is constructed using the four-sided frame body 106, which fixes the relative positions of the internal components, thereby ensuring the regularity of the internal flow channels and reaction areas of the unit tank 100 and improving the interchangeability between unit tanks. The bottom of the unit tank 100 is sealed by the bent chassis 107, which supports the alkali solution and internal components, preventing alkali leakage and providing basic space for alkali circulation. The alkali solution is delivered through the inlet component 103, which evenly distributes the alkali solution to the reaction areas on both the cathode and anode sides, ensuring the continuous and efficient electrolysis reaction. The gas-liquid mixture A3 generated by the reaction is collected through the outlet component 104, guiding the orderly flow of fluids and creating conditions for subsequent gas-liquid pre-separation. The gas-liquid box component 105 receives the gas and liquid phases after pre-separation by the outlet component 104, allowing for the separate export of gas and return of alkali solution, thus improving the continuity of gas-liquid separation. The cathode mesh 1012 serves as the cathode reaction carrier, enabling the hydrogen evolution reaction to generate hydrogen, thereby achieving the core goal of hydrogen production. The elastic buffer net 1011 undergoes elastic deformation under the pressure, adjusting the distance between the cathode net 1012 and the diaphragm body 50, thereby stabilizing the membrane electrode spacing structure, reducing mass transfer resistance, and lowering energy consumption. The cathode bottom net 1010 supports the cathode net 1012 and the elastic buffer net 1011, dispersing the pressure transmitted by the extruder 80, thus preventing deformation of the cathode net 1012 due to excessive local stress. The anode net 101 serves as the anode reaction carrier, initiating the oxygen evolution reaction to generate oxygen, thus completing the associated reactions for water electrolysis. The cathode circulation plate 109 and the anode circulation plate 1013, together with the bent chassis 107, form a circulation channel, guiding the directional circulation of the alkaline solution, accelerating gas removal from the electrode surface, reducing surface gas resistance, improving electrolysis efficiency, and adapting to current fluctuations caused by wind-solar coupled power generation.The bubble-breaking mesh 10401 breaks the bubbles in the gas-liquid mixture A3, which plays a preliminary role in separating the gas and the alkaline solution, thereby reducing the working pressure of the downstream separator and improving the overall system's ability to adapt to the fluctuations of wind-solar coupled power generation.

[0040] Please see the appendix Figure 1 -Appendix Figure 7 The compression of the elastic buffer net 1011 is 50% to 58% of the free height; the outlet assembly 104 also includes a gas-liquid rectangular tube 10404, a support plate 10402 and a separation plate 10403; the debubbling net 10401 is disposed in the flow channel of the gas-liquid rectangular tube 10404, and the separation plate 10403 divides the inner cavity of the outlet assembly 104 into an upper gas chamber and a lower liquid chamber, with the cross-sectional area ratio of the gas chamber to the liquid chamber being 1 to 2.

[0041] Specifically, by controlling the compression of the elastic buffer net 1011 within a reasonable range, it balances the elastic support capacity and the precision of the membrane electrode gap. This ensures that the cathode mesh 1012 remains tightly attached to the diaphragm body 50 to reduce mass transfer resistance, while preventing excessive compression that could cause the elastic buffer net 1011 to lose its resilience and affect the long-term stability of the membrane electrode gap. The gas-liquid rectangular tube 10404 constructs a regular fluid channel, constraining the flow path of the gas-liquid mixture A3. This allows the gas-liquid mixture A3 to flow precisely and uniformly through the bubble-breaking net 10401, improving the uniformity of bubble breaking. By placing the bubble-breaking net 10401 within the flow channel of the gas-liquid rectangular tube 10404, it effectively contacts and tears the bubbles in the gas-liquid mixture A3, thus allowing for initial separation of the gas and alkali solution and reducing the pressure in subsequent separation stages. The support plate 10402 fixes the installation positions of the defoaming net 10401 and the separation plate 10403, maintaining the stability of the internal structure of the outlet component 104 and preventing flow channel blockage or separation failure caused by component displacement during equipment operation. The separation plate 10403 divides the inner cavity of the outlet component 104 into an upper gas chamber and a lower liquid chamber, with a cross-sectional area ratio suitable for the gas-liquid two-phase flow characteristics, accommodating different flow velocities of gas rising and liquid sinking. This allows the gas to quickly gather in the gas chamber for discharge, while the alkaline solution flows stably into the liquid chamber for reflux, improving the efficiency and stability of gas-liquid pre-separation and reducing the operating load of the downstream separator.

[0042] Please see the appendix Figure 1 -Appendix Figure 7The cathode side and anode side are respectively provided with a cathode conductive support tube 108 and an anode conductive support tube 102, both of which are trapezoidal tube structures; the extruder 80 includes an end fixed seat 804, a movable seat 802, a hydraulic cylinder 801 for driving the movable seat 802, a locking screw 803, and a guide rail 805; the unit slot 100, the end cathode slot 20, and the end anode slot 30 are all provided with a handle bracket 1014, which is supported on the guide rail 805 for positioning; the end cathode slot 20 and the end anode slot 30 each include an end four-sided frame 201, a conductive plate 202, a support grid 203, a back plate 204, an inlet component 103, an outlet component 104, a gas-liquid box component 105, a bending chassis 107, and a handle bracket 1014.

[0043] Specifically, the trapezoidal tube structure of the cathode conductive support tube 108 and the anode conductive support tube 102 increases the current conduction contact area, thereby allowing the current to be evenly distributed to all areas of the cathode mesh 1012 and the anode mesh 101, reducing the current conduction resistance, ensuring stable electrolysis, and minimizing the voltage difference between adjacent chambers. The hydraulic cylinder 801 provides a stable driving force, pushing the movable seat 802 along the guide rail 805, thereby applying uniform clamping force to the end cathode groove 20, unit groove 100, and end anode groove 30, ensuring the stable formation of the membrane electrode gap structure. The end fixing seat 804 provides a reverse support force, forming a bidirectional clamping effect with the movable seat 802, thus maintaining the overall stability of the electrolytic cell structure and preventing loosening during operation. The locking screw 803 locks the position of the movable seat 802, maintaining a constant clamping force over a long period, preventing clamping force attenuation due to equipment vibration, ensuring the long-term stability of the membrane electrode gap, and extending the service life of the equipment. The guide rail 805 provides movement guidance for the handle bracket 1014, accurately positioning the assembly positions of each tank and improving the assembly accuracy of the electrolytic cell. The handle bracket 1014 supports the unit tank 100, the end cathode tank 20, and the end anode tank 30, facilitating disassembly and maintenance and reducing the difficulty and cost of later maintenance. The end four-sided frame 201 constructs the frame structure of the end tank, fixing the relative positions of the internal components and ensuring structural compatibility between the end tank and the unit tank 100. The conductive plate 202 receives external input current, uniformly supplying power to the end cathode tank 20 and the end anode tank 30, providing a stable current foundation for the electrolytic reaction of the entire electrolytic cell. The supporting grid 203 supports the conductive plate 202, dispersing the clamping force applied by the extruder 80 and preventing deformation of the conductive plate 202 due to excessive localized stress. The back plate 204 enhances the structural strength of the end cathode tank 20 and the end anode tank 30, resisting the impact of clamping force and extending the service life of the end tank. The inlet component 103, outlet component 104, gas-liquid box component 105, and bending chassis 107 on the end tank work together with the corresponding components of the unit tank 100 to form a fluid circulation channel that runs from end to end. This also improves the interchangeability of components between the end tank and the unit tank, thereby ensuring smooth flow of alkali and orderly discharge of gas-liquid mixture, and improving the operational stability and maintenance convenience of the entire hydrogen production system.

[0044] Example 2: Please refer to the appendix Figure 8 -Appendix Figure 11 This embodiment describes a flexible hydrogen production method suitable for wind-solar coupled hydrogen production, employing a square electrolyzer as described above, and includes the following steps:

[0045] S1. Assembly and clamping: The insulating plate 70, the end cathode groove 20, the cathode gasket 40, the diaphragm body 50, the anode gasket 60, at least one unit groove 100 and the end anode groove 30 are placed sequentially between the end fixed seat 804 and the movable seat 802 of the extruder 80. The movable seat 802 is pushed by the hydraulic cylinder 801 to clamp the components, so that the elastic buffer net 1011 in the unit groove 100 is compressed to form the membrane electrode distance structure.

[0046] Specifically, the insulating plate 70 isolates the end cathode tank 20 and end anode tank 30 from the extruder 80, preventing current leakage and ensuring the safety of the electrolytic reaction. The precise stacking of the tanks and gaskets in sequence ensures the regularity of the internal structure of the electrolytic cell, laying a foundation for uniform current transfer and fluid flow. The hydraulic cylinder 801 pushes the movable seat 802 to gradually press the components, causing the elastic buffer mesh 1011 to deform controllably, thus precisely forming the membrane electrode distance structure and reducing the mass transfer resistance between the anode and cathode. The locking screw 803 locks the position of the movable seat 802, maintaining stable clamping force over the long term, preventing vibrations during equipment operation from causing changes in the membrane electrode distance and ensuring the long-term stable operation of the electrolytic cell.

[0047] S2. Electrolysis Gas Generation: Inlet alkaline solution A1 is introduced into the assembled square electrolytic cell and electrolysis is carried out. Anode mesh 101 generates oxygen and cathode mesh 1012 generates hydrogen. The generated gas drives the alkaline solution to flow, forming circulating alkaline solution A4 and finally forming a gas-liquid mixture A3.

[0048] Specifically, the imported component 103 evenly distributes the alkaline solution to the cathode and anode sides of the unit cell 100, ensuring sufficient and evenly distributed alkaline solution in each reaction zone, thereby maintaining the continuous and efficient electrolysis reaction. Oxygen evolution and hydrogen evolution reactions occur respectively through the anode mesh 101 and cathode mesh 1012, generating oxygen and hydrogen, thus achieving the core objective of hydrogen production. The principle of air flotation drives the flow of the alkaline solution, forming a gas-liquid mixture A3. This mixture circulates the alkaline solution within the flow channel formed by the cathode circulation plate 109, anode circulation plate 1013, and bending chassis 107, accelerating gas removal from the electrode surface, reducing gas resistance on the electrode surface, and adapting to current fluctuations caused by wind-solar coupling power generation, preventing gas resistance buildup during sudden changes in gas production.

[0049] S3. Pre-separation in unit tank: Gas-liquid mixture A3 enters the outlet component 104 of unit tank 100. After the bubble is broken by the bubble-breaking net 10401, gas-liquid pre-separation is achieved. The separated gas and alkaline solution are discharged in a stratified form through the gas-liquid box component 105.

[0050] Specifically, the gas-liquid mixture A3 is guided to flow in a directional manner through the gas-liquid rectangular tube 10404 of the outlet component 104, ensuring that the gas-liquid mixture A3 fully contacts the bubble-breaking net 10401, thereby improving the bubble breaking efficiency. The bubble-breaking net 10401 tears the bubbles in the gas-liquid mixture A3, achieving initial separation of gas and alkali, thus creating conditions for subsequent gas-liquid stratification. The separation plate 10403 divides the inner cavity of the outlet component 104 into a gas chamber and a liquid chamber, guiding the gas to rise and the liquid to sink, thereby achieving efficient gas-liquid stratification. The gas-liquid box component 105 separately discharges the stratified gas and alkali, improving the continuity of gas-liquid separation, thereby reducing the working pressure of the downstream hydrogen separator 3 and oxygen separator 4, and enhancing the system's adaptability to wind and solar fluctuations.

[0051] S4. System Separation and Alkali Collection: The gas-liquid mixture discharged from the cathode side is passed into the hydrogen separator 3 for gas-liquid separation. The separated hydrogen is cooled by the hydrogen heat exchanger 5 and washed by the hydrogen scrubber 7 before being discharged. The gas-liquid mixture discharged from the anode side is passed into the oxygen separator 4 for gas-liquid separation. The separated oxygen is cooled and washed before being discharged. The alkali returned from the hydrogen separator 3, oxygen separator 4, and scrubbing equipment is collected into a common buffer tank 14.

[0052] Furthermore, the buffer tank 14 is provided with a partition, which divides the tank into two parts corresponding to the cathode side and the anode side respectively, and the bottom of the partition is provided with a connecting structure.

[0053] Furthermore, before the gas-liquid mixture is introduced into the hydrogen separator 3 and the oxygen separator 4, it passes through the ball valve 2. The separated hydrogen is discharged after being detected by the hydrogen-oxygen analyzer 11, and the separated oxygen is discharged after being detected by the oxygen-hydrogen analyzer 12. The washing water for the hydrogen scrubber 7 and the oxygen scrubber 8 is supplied by the water tank 18 through the water pump 19. The flow rates of the discharged hydrogen and oxygen are regulated by the hydrogen pneumatic diaphragm regulating valve 9 and the oxygen pneumatic diaphragm regulating valve 10, respectively.

[0054] Specifically, ball valve 2 controls the on / off state and flow rate of the gas-liquid mixture on the cathode and anode sides, regulating the fluid input rhythm to address gas production fluctuations caused by wind-solar coupled power generation. Hydrogen separator 3 and oxygen separator 4 perform secondary separation on the pre-separated gas-liquid mixture, further purifying hydrogen and oxygen and improving the purity of the product gas. Hydrogen-oxygen analyzer 11 and oxygen-hydrogen analyzer 12 monitor gas purity in real time, monitoring gas safety indicators to prevent safety hazards caused by excessive hydrogen and oxygen content. Water tank 18 and water pump 19 provide washing water to hydrogen scrubber 7 and oxygen scrubber 8, removing alkaline impurities from the gas and improving gas quality. Hydrogen pneumatic diaphragm regulating valve 9 and oxygen pneumatic diaphragm regulating valve 10 regulate the gas discharge flow rate, maintaining stable internal pressure within the separators and preventing pressure fluctuations from affecting the electrolyzer operation. The baffle in buffer tank 14 initially isolates the alkaline solutions on the cathode and anode sides, preventing cross-contamination of hydrogen and oxygen gases. Simultaneously, the connecting structure at the bottom of the baffle mixes the alkaline solutions from both electrodes, thereby balancing the alkaline concentration and ensuring stable electrolysis. By collecting the alkaline solutions returning from the separators and scrubbers, the liquid level in buffer tank 14 is balanced, thus addressing level fluctuations caused by variations in gas production and maintaining flexible system operation.

[0055] S5. Alkali solution constant pressure circulation supply: The alkali solution in the buffer tank 14 is transported to the diaphragm pressure-maintaining alkali tank 17 by the shielded pump 15; nitrogen C1 at a constant pressure is introduced into the nitrogen chamber of the diaphragm pressure-maintaining alkali tank 17 to supply the alkali solution back to the square electrolytic cell.

[0056] Furthermore, the shielded pump 15 delivers the alkali solution to the heat exchanger body 16 for temperature regulation, and then sends it to the diaphragm-type pressure-maintaining alkali tank 17; the flow rate of the alkali solution supplied back to the square electrolytic cell is regulated by the alkali solution pneumatic diaphragm regulating valve 13.

[0057] Specifically, the shielded pump 15 transports the alkaline solution in the buffer tank 14 to the heat exchanger body 16, providing power for the alkaline solution. Simultaneously, the heat exchanger body 16 regulates the alkaline solution temperature, thereby removing waste heat generated by the electrolysis reaction and ensuring the electrolyzer operates at a suitable temperature. A constant pressure of nitrogen is introduced into the nitrogen chamber of the diaphragm-type pressure-maintaining alkaline tank 17, maintaining stable pressure in the alkaline solution chamber and flexibly adapting to changes in alkaline solution demand due to fluctuations in gas production, preventing insufficient alkaline solution supply or backflow. The alkaline solution pneumatic diaphragm regulating valve 13 regulates the flow rate of alkaline solution returning to the electrolyzer, precisely controlling the alkaline solution supply and ensuring a stable flow rate within the unit cell 100, thus improving electrolysis efficiency. The coordinated operation of the entire alkaline solution circulation system adapts to fluctuations in the wind-solar coupled power generation current, enabling flexible operation of the hydrogen production process.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A square electrolyzer suitable for wind-solar coupled hydrogen production, comprising an end cathode cell (20), at least one unit cell (100), and an end anode cell (30) stacked sequentially along the electrolysis direction, and an extruder (80) for pressing and fixing each cell; a diaphragm body (50), a cathode gasket (40), and an anode gasket (60) are provided between adjacent cells; characterized in that: The unit tank (100) includes a four-sided frame body (106), a bending chassis (107), an inlet assembly (103), an outlet assembly (104), and a gas-liquid box assembly (105); its interior is divided into a cathode side and an anode side by the diaphragm body (50); the cathode side is provided with a cathode mesh (1012), and an elastic buffer mesh (1011) is sandwiched between the cathode mesh (1012) and the diaphragm body (50); the side of the elastic buffer mesh (1011) facing away from the diaphragm body (50) is provided with a cathode bottom mesh (1010); the anode side is provided with an anode mesh (101); the extruder (80) The clamping force provided by the electrode mesh compresses the elastic buffer mesh (1011), thereby causing the cathode mesh (1012) and anode mesh (101) to adhere tightly to the diaphragm body (50) to form a membrane electrode distance structure; the cathode side and the anode side are also provided with a cathode circulation plate (109) and an anode circulation plate (1013), respectively, and the cathode circulation plate (109) and the anode circulation plate (1013) form a flow channel between them and the bending chassis (107) to promote the internal circulation of the alkali solution; the outlet assembly (104) includes a defoaming mesh (10401) for defoaming the gas-liquid mixture (A3) from the electrode mesh to achieve gas-liquid pre-separation.

2. A square electrolyzer for wind-solar coupled hydrogen production according to claim 1, characterized in that: The compression of the elastic buffer net (1011) is 50% to 58% of its free height.

3. A square electrolyzer for wind-solar coupled hydrogen production according to claim 1, characterized in that: The outlet assembly (104) further includes a gas-liquid rectangular tube (10404), a support plate (10402), and a separation plate (10403); the defoaming mesh (10401) is disposed in the flow channel of the gas-liquid rectangular tube (10404), and the separation plate (10403) divides the inner cavity of the outlet assembly (104) into an upper gas chamber and a lower liquid chamber, wherein the cross-sectional area ratio of the gas chamber to the liquid chamber is 1~2.

4. A square electrolyzer for wind-solar coupled hydrogen production according to claim 1, characterized in that: The cathode side and the anode side are respectively provided with a cathode conductive support tube (108) and an anode conductive support tube (102), both of which are trapezoidal tube structures.

5. A square electrolyzer for wind-solar coupled hydrogen production according to claim 1, characterized in that: The extruder (80) includes an end fixed seat (804), a movable seat (802), a hydraulic cylinder (801) for driving the movable seat (802), a locking screw (803), and a guide rail (805); each of the unit slot (100), the end cathode slot (20), and the end anode slot (30) is provided with a handle bracket (1014), which is supported on the guide rail (805) for positioning.

6. A square electrolyzer for wind-solar coupled hydrogen production according to claim 1, characterized in that: Both the end cathode groove (20) and the end anode groove (30) include an end four-sided frame (201), a conductive plate (202), a support grid (203), a back plate (204), an inlet assembly (103), an outlet assembly (104), a gas-liquid box assembly (105), a bending chassis (107), and a handle bracket (1014).

7. A flexible hydrogen production method suitable for wind-solar coupled hydrogen production, characterized in that, The square electrolyzer for wind-solar coupled hydrogen production, as described in any one of claims 1-6, comprises the following steps: S1. Assembly and pressing: The insulating plate (70), the end cathode groove (20), the cathode gasket (40), the diaphragm body (50), the anode gasket (60), at least one unit groove (100) and the end anode groove (30) are placed in sequence between the end fixed seat (804) and the movable seat (802) of the extruder (80). The movable seat (802) is pushed by the oil cylinder (801) to press each component, so that the elastic buffer net (1011) in the unit groove (100) is compressed to form the membrane electrode distance structure. S2, Electrolysis Gas Generation: Inlet alkaline solution (A1) is introduced into the assembled square electrolytic cell and electrolysis is carried out. The anode mesh (101) generates oxygen and the cathode mesh (1012) generates hydrogen. The generated gas drives the alkaline solution to flow, forming a circulating alkaline solution (A4) and finally forming a gas-liquid mixture (A3). S3, Pre-separation in unit tank: The gas-liquid mixture (A3) enters the outlet component (104) of the unit tank (100), and gas-liquid pre-separation is achieved after the bubble is broken by the bubble-breaking net (10401). The separated gas and alkaline solution are discharged in a stratified form through the gas-liquid box component (105). S4. System separation and alkaline solution collection: The gas-liquid mixture discharged from the cathode side is fed into the hydrogen separator (3) for gas-liquid separation. The separated hydrogen is cooled by the hydrogen heat exchanger (5) and washed by the hydrogen scrubber (7) before being discharged. The gas-liquid mixture discharged from the anode side is fed into the oxygen separator (4) for gas-liquid separation. The separated oxygen is cooled and washed before being discharged. The alkaline solution returned from the hydrogen separator (3), oxygen separator (4) and scrubbing equipment is collected into a common buffer tank (14). S5, Alkali constant pressure circulation supply: The alkali in the buffer tank (14) is transported to the diaphragm pressure-maintaining alkali tank (17) by the shielded pump (15); nitrogen (C1) at constant pressure is filled into the nitrogen chamber of the diaphragm pressure-maintaining alkali tank (17) to supply the alkali back to the square electrolytic cell.

8. A flexible hydrogen production method suitable for wind-solar coupled hydrogen production according to claim 7, characterized in that: The buffer tank (14) is provided with a partition, which divides the tank into two parts corresponding to the cathode side and the anode side respectively, and the bottom of the partition is provided with a connecting structure.

9. A flexible hydrogen production method suitable for wind-solar coupled hydrogen production according to claim 7, characterized in that: In step S4, the gas-liquid mixture passes through ball valve (2) before entering the hydrogen separator (3) and oxygen separator (4). The separated hydrogen is discharged after being detected by hydrogen-oxygen analyzer (11), and the separated oxygen is discharged after being detected by oxygen-hydrogen analyzer (12). The washing water for the hydrogen scrubber (7) and oxygen scrubber (8) is supplied by water tank (18) through water pump (19). The flow rates of the discharged hydrogen and oxygen are regulated by hydrogen pneumatic diaphragm regulating valve (9) and oxygen pneumatic diaphragm regulating valve (10), respectively.

10. A flexible hydrogen production method suitable for wind-solar coupled hydrogen production according to claim 7, characterized in that: In step S5, the shielded pump (15) delivers the alkali solution to the heat exchanger body (16) for temperature regulation, and then sends it to the diaphragm-type pressure-maintaining alkali tank (17); the flow rate of the alkali solution supplied back to the square electrolytic cell is regulated by the alkali solution pneumatic diaphragm regulating valve (13).

Images