Flow velocity control device for electrolytic bath

Abstract

The invention relates to a flow rate control device for an electrolytic bath, and relates to the technical field of water electrolysis hydrogen production, the flow rate control device comprises a support frame, the support frame is provided with a through groove in a penetrating manner, an elastic membrane is arranged in the through groove, one side of the elastic membrane is a flow channel, the other side of the elastic membrane is a pressure cavity, and a corrugated pipe compensator and a honeycomb microporous membrane are arranged in the pressure cavity; one side of the honeycomb microporous membrane is attached to the side, away from the flow channel, of the elastic membrane, the other side of the honeycomb microporous membrane is fixedly connected with one end of the corrugated pipe compensator, the other end of the corrugated pipe compensator is fixedly connected with the supporting frame, a plurality of honeycomb holes are formed in the honeycomb microporous membrane in a penetrating mode and communicate with the corrugated pipe compensator, and the corrugated pipe compensator is fixedly connected with the supporting frame. The honeycomb holes and the corrugated pipe compensator are filled with nitrogen. The method has the effect of reducing the energy consumption of hydrogen production through water electrolysis.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology through water electrolysis, and in particular to a flow rate control device for an electrolyzer. Background Technology

[0002] Hydrogen energy, due to its abundant sources, high energy density, and zero emissions during combustion, is considered a core carrier of the future energy system. Electrolysis of water to produce hydrogen converts electrical energy into high-purity hydrogen for storage, offering dual value in peak shaving and energy storage.

[0003] Currently, alkaline electrolyzers used in water electrolysis for hydrogen production generally employ a fixed-section electrode frame flow channel design, using electrolyte circulation to remove bubbles and heat. Under rated operating conditions, the flow channel cross-sectional area is matched with the flow rate, reducing the proportion of power consumption of the circulation pump in the system's energy consumption and enabling timely removal of hydrogen and oxygen gases. When the input power from renewable energy sources fluctuates, the electrolyzer needs to be frequently adjusted between 10% and 150% of its rated load.

[0004] When the electrolyte flow rate is below 0.3 m / s, the residence time of the electrolyte in the electrode area is prolonged, which intensifies the mutual diffusion of hydrogen and oxygen gases and causes continuous loss of bypass current. When the electrolyte flow rate exceeds the rated value, the turbulent pressure drop increases dramatically, and the power consumption of the circulating pump exceeds the system energy consumption. Summary of the Invention

[0005] To reduce the energy consumption of hydrogen production through water electrolysis, this application provides a flow rate control device for an electrolyzer.

[0006] The flow rate control device for an electrolytic cell provided in this application adopts the following technical solution: An electrolytic cell flow rate control device includes a support frame with a through-slot. An elastic membrane is disposed within the through-slot. One side of the elastic membrane is a flow channel, and the other side is a pressure chamber. A bellows compensator and a honeycomb microporous membrane are disposed within the pressure chamber. One side of the honeycomb microporous membrane is attached to the side of the elastic membrane away from the flow channel, and the other side of the honeycomb microporous membrane is fixedly connected to one end of the bellows compensator. The other end of the bellows compensator is fixedly connected to the support frame. A plurality of honeycomb holes are formed through the honeycomb microporous membrane, and the honeycomb holes communicate with the bellows compensator. The honeycomb holes and the bellows compensator are filled with nitrogen gas.

[0007] By adopting the above technical solution, when the electrolyte enters the flow channel at a low flow rate, the static pressure in the flow channel decreases, and the pressure difference in the pressure chamber becomes less than 0 through conduction via the honeycomb microporous membrane. At this time, the bellows compensator pushes the elastic membrane, reducing the cross-sectional area of ​​the flow channel and forcing the flow velocity to increase again. The residence time of the electrolyte in the flow channel is shortened, reducing the hydrogen concentration in the oxygen and reducing the continuous loss of bypass current. When the power generation suddenly increases, the electrolyte circulation volume increases, causing the static pressure in the flow channel to rise, and the pressure difference in the pressure chamber becomes greater than 0 through conduction via the honeycomb microporous membrane. At this time, the bellows compensator pulls the elastic membrane, expanding the cross-sectional area of ​​the flow channel to suppress the turbulence intensity and reduce the power consumption of the circulating pump. By dynamically adjusting the cross-sectional area of ​​the flow channel, the energy consumption for hydrogen production through water electrolysis is reduced.

[0008] Preferably, the elastic membrane covers all the honeycomb holes, the central axis of the honeycomb holes is horizontally set, and the central axis of the honeycomb holes is perpendicular to the central axis of the bellows compensator.

[0009] By adopting the above technical solution, the honeycomb pores are arranged horizontally, reducing the penetration of alkaline vapor along the honeycomb pores.

[0010] Preferably, the elastic membrane is made of perfluoroether rubber, and the thickness of the elastic membrane increases from the center to the edge.

[0011] By adopting the above technical solution, the elastic membrane has high sensitivity, while the thicker edge of the elastic membrane improves the sealing reliability of the elastic membrane.

[0012] Preferably, the elastic membrane has microgrooves on the side away from the honeycomb microporous membrane, the width of the microgrooves is 20μm, and the depth of the microgrooves is 10μm.

[0013] By adopting the above technical solution, microgrooves reduce the resistance to electrolyte flow.

[0014] Preferably, the honeycomb microporous membrane is made of perfluoroether rubber, and the inner wall of the honeycomb pores is sputtered with a polytetrafluoroethylene coating.

[0015] By adopting the above technical solution, the polytetrafluoroethylene coating reduces the friction coefficient of the inner wall of the honeycomb pores.

[0016] Preferably, the honeycomb cells are arranged in a regular hexagonal honeycomb pattern.

[0017] By adopting the above technical solution, when the honeycomb microporous membrane is under pressure, the honeycomb microporous membrane transmits the pressure to the bellows compensator. At the same time, the honeycomb microporous membrane deforms and squeezes the nitrogen gas in the honeycomb pores, so that the pressure is evenly transmitted to the bellows compensator. By transmitting pressure in two ways in synergy, the pressure transmission efficiency is improved, and if one way fails, the other way transmits a part of the pressure.

[0018] Preferably, the inner wall of the bellows compensator is provided with an aluminum oxide protective layer.

[0019] By adopting the above technical solution, the alumina protective layer forms a protective layer on the inner wall of the bellows compensator.

[0020] Preferably, the inner wall of the channel is coated with a polyphenylene sulfide coating.

[0021] By adopting the above technical solution, the support frame contacts the electrolyte through a polyphenylene sulfide coating, thereby reducing the bypass current.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. By setting up a support frame, through groove, elastic membrane, flow channel, pressure chamber, bellows compensator, honeycomb microporous membrane and honeycomb pores, and by dynamically adjusting the cross-sectional area of ​​the flow channel, the energy consumption of hydrogen production by water electrolysis can be reduced; 2. By setting microgrooves, the resistance to electrolyte flow is reduced; 3. By setting a polyphenylene sulfide coating, the support frame can contact the electrolyte through the polyphenylene sulfide coating, thereby reducing the bypass current. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of a flow rate control device for an electrolytic cell according to an embodiment of this application.

[0024] Figure 2 yes Figure 1 Enlarged view of section A.

[0025] Figure 3 This is a cross-sectional view illustrating the positional relationship between the elastic membrane and the microgrooves in an embodiment of this application.

[0026] Figure 4 This is a cross-sectional view showing the positional relationship between the bellows compensator and the alumina protective layer in the embodiments of this application.

[0027] Explanation of reference numerals in the attached drawings: 1. Support frame; 11. Polyphenylene sulfide coating; 12. Through groove; 2. Elastic membrane; 21. Microgroove; 3. Pressure chamber; 4. Bellows compensator; 41. Alumina protective layer; 5. Honeycomb microporous membrane; 51. Honeycomb pore; 52. Polytetrafluoroethylene coating; 6. Flow channel. Detailed Implementation

[0028] The following is combined with Figure 1-4 This application is described in further detail.

[0029] This application discloses a flow rate control device for an electrolytic cell. (Refer to...) Figure 1The system includes a support frame 1, through which a through groove 12 is provided. An elastic membrane 2 made of perfluoroether rubber is installed within the through groove 12. One side of the elastic membrane 2 is a flow channel 6, and the other side is a pressure chamber 3. A pressure chamber 3 is formed between the elastic membrane 2 and the support frame 1. A bellows compensator 4 and a honeycomb microporous membrane 5 are installed within the pressure chamber 3.

[0030] refer to Figure 1 The support frame 1 is made of Hastelloy C276 alloy. The support frame 1 is mounted on the side wall of the electrode frame via vacuum brazing. The brazing filler metal is BAg-8 silver-based alloy with a melting point of 780℃. A sealed interface is formed between the support frame 1 and the electrode frame, with a helium leakage rate of less than [value missing]. A polyphenylene sulfide coating 11 is plated on the inner wall of the through channel 12. The polyphenylene sulfide coating 11 contacts the electrolyte in the flow channel 6, reducing bypass current.

[0031] refer to Figures 1 to 3 The thickness of the elastic membrane 2 increases from the center to the edge, giving it high sensitivity while the thicker edge enhances its sealing reliability. Microgrooves 21, 20 μm wide and 10 μm deep, are laser-engraved on the side of the elastic membrane 2 furthest from the honeycomb microporous membrane 5. The side of the elastic membrane 2 furthest from the support frame 1 contacts the electrolyte, and the microgrooves 21 reduce the electrolyte flow resistance.

[0032] refer to Figures 1 to 4 The bellows compensator 4 is made of 316L platinum-plated material. It is pre-filled with 0.20 MPa of high-purity nitrogen before being cold-welded. The inner wall of the bellows compensator 4 is electroplated with aluminum to form an aluminum oxide protective layer 41. One end of the bellows compensator 4 is bonded to the honeycomb microporous membrane 5 using vulcanization technology, and the other end is welded to the support frame 1 using laser welding technology. The support frame 1 provides protection for the bellows compensator 4.

[0033] refer to Figure 1 and Figure 2A honeycomb microporous membrane 5 has several honeycomb holes 51 arranged in a regular hexagonal honeycomb pattern. The honeycomb holes 51 are angled, with their axes forming a 15° angle with the flow direction, achieving self-cleaning through shear force. A polytetrafluoroethylene (PTFE) coating 52, 5 μm thick and with a contact angle of 110°, is sputtered onto the inner wall of each honeycomb hole 51. The honeycomb holes 51 are filled with nitrogen gas, and the bellows compensator 4 is connected to the honeycomb holes 51 via a laser weld. The honeycomb microporous membrane 5 is made of perfluoroether rubber and is bonded to an elastic membrane 2, which covers all the honeycomb holes 51. The central axis of the honeycomb holes 51 is horizontally aligned and perpendicular to the central axis of the bellows compensator 4. The transverse arrangement of the honeycomb holes 51 reduces the penetration of alkaline vapor along them. When the honeycomb microporous membrane 5 is compressed, it transmits the pressure to the bellows compensator 4. At the same time, the honeycomb microporous membrane 5 deforms and compresses the nitrogen gas inside the honeycomb pores 51, so that the pressure is evenly transmitted to the bellows compensator 4. By transmitting pressure in two ways in synergy, the pressure transmission efficiency is improved, and if one method fails, the other method transmits a portion of the pressure.

[0034] The implementation principle of the flow rate control device for an electrolyzer in this embodiment is as follows: When the electrolyte enters the flow channel 6 at a low flow rate, the static pressure in the flow channel 6 decreases, and the pressure difference in the pressure chamber 3 becomes less than 0 through conduction via the honeycomb microporous membrane 5. At this time, the bellows compensator 4 pushes the elastic membrane 2, reducing the cross-sectional area of ​​the flow channel 6 and forcing the flow rate to increase again. The residence time of the electrolyte in the flow channel 6 is shortened, reducing the hydrogen concentration in oxygen and reducing the continuous loss of bypass current. When the power generation suddenly increases, the electrolyte circulation volume increases, causing the static pressure in the flow channel 6 to rise. The pressure difference in the pressure chamber 3 becomes greater than 0 through conduction via the honeycomb microporous membrane 5. At this time, the bellows compensator 4 pulls the elastic membrane 2, expanding the cross-sectional area of ​​the flow channel 6 to suppress the turbulence intensity and reduce the power consumption of the circulation pump. By dynamically adjusting the cross-sectional area of ​​the flow channel 6, the energy consumption for hydrogen production through water electrolysis is reduced.

[0035] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A flow rate control device for an electrolytic cell, comprising a support frame, wherein a through groove is provided through the support frame, characterized in that: An elastic membrane is installed inside the channel. One side of the elastic membrane is a flow channel, and the other side is a pressure chamber. A bellows compensator and a honeycomb microporous membrane are installed inside the pressure chamber. One side of the honeycomb microporous membrane is attached to the side of the elastic membrane away from the flow channel, and the other side of the honeycomb microporous membrane is fixedly connected to one end of the bellows compensator. The other end of the bellows compensator is fixedly connected to the support frame. Several honeycomb holes are provided through the honeycomb microporous membrane. The honeycomb holes are connected to the bellows compensator, and the honeycomb holes and the bellows compensator are filled with nitrogen gas.

2. The flow rate control device for an electrolytic cell according to claim 1, characterized in that: The elastic membrane covers all the honeycomb holes, and the central axis of the honeycomb holes is set horizontally. The central axis of the honeycomb holes is perpendicular to the central axis of the bellows compensator.

3. The flow rate control device for an electrolytic cell according to claim 1, characterized in that: The elastic membrane is made of perfluoroether rubber, and its thickness increases from the center to the edge.

4. The flow rate control device for an electrolytic cell according to claim 1, characterized in that: The elastic membrane has microgrooves on the side away from the honeycomb microporous membrane. The width of the microgrooves is 20 μm and the depth of the microgrooves is 10 μm.

5. The flow rate control device for an electrolytic cell according to claim 1, characterized in that: The honeycomb microporous membrane is made of perfluoroether rubber, and the inner wall of the honeycomb pores is sputtered with a polytetrafluoroethylene coating.

6. The flow rate control device for an electrolytic cell according to claim 1, characterized in that: The honeycomb cells are arranged in a regular hexagonal honeycomb pattern.

7. The flow rate control device for an electrolytic cell according to claim 1, characterized in that: The inner wall of the bellows compensator is provided with an aluminum oxide protective layer.

8. The flow rate control device for an electrolytic cell according to claim 1, characterized in that: The inner wall of the channel is coated with polyphenylene sulfide.

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