Electrolytic hydrogen production device pre-separation system based on gravity separation principle

Abstract

The invention discloses an electrolytic hydrogen production device pre-separation system based on a gravity separation principle, which comprises an electrolytic bath and a gas-liquid separator, a pre-separator is arranged on a material pipeline of the electrolytic bath entering the gas-liquid separator, a mixture inlet and a liquid outlet are arranged at the lower part of the pre-separator, and a gas outlet is arranged at the top of the pre-separator. The mixture inlet is connected with the outlet end of the electrolytic cell through a material pipeline, the liquid outlet is connected to a liquid phase in the gas-liquid separator through a liquid pipeline, and the gas outlet is connected to a top gas phase of the gas-liquid separator through a gas pipeline. The pre-separator is innovatively and additionally arranged. According to the gravity separation principle, a vertical cylindrical shell is adopted. By means of the layout, gas and liquid can be preliminarily separated within a very short time, the workload of a subsequent gas-liquid separator is greatly relieved, the overall separation efficiency is remarkably improved, and a solid foundation is laid for efficient operation of the whole electrolytic hydrogen production process.

Description

Technical Field

[0001] The invention relates to the technical field of gas-liquid separation, and in particular to a pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle. Background Art

[0002] In the electrolytic hydrogen production system, the gas-liquid separation system plays an important role in separating gas and liquid. Specifically, the gas-liquid separation system separates the gas-liquid mixture of hydrogen or oxygen from the electrolyzer and alkali liquid. The hydrogen branch mainly includes a hydrogen separator, a hydrogen scrubber, and a hydrogen cooler; the oxygen branch mainly includes an oxygen separator, an oxygen scrubber, and an oxygen cooler; as well as an alkali liquid cooler, an alkali liquid filter (one open and one standby), an alkali liquid circulation pump (one open and one standby), a water supply pump, instruments, valves, pipelines, pipe fittings, frames, etc.; the gas-liquid separation system control cabinet is the core of the control part, which can realize automatic adjustment, display, alarm, interlocking and other functions to ensure the safe and stable operation of the electrolyzer and the gas-liquid separation system.

[0003] Take the gas-liquid separation on the hydrogen side as an example to illustrate. The gas-liquid separation process on the oxygen side is basically the same and will not be repeated. The hydrogen and alkali liquid gas-liquid mixture coming out of the electrolyzer is separated into gas and liquid and flows through the gas outlet hole on the cathode side of the pole frame through the hydrogen flow channel, flows out from the negative pole frame, and enters the hydrogen separator after being collected. Under the action of gravity sedimentation, the initial gas-liquid separation is carried out to separate the hydrogen and alkali liquid.

[0004] In the prior art, the gas and liquid coming out of the electrolyzer directly enter the gas-liquid separator for gas-liquid separation, such as the application number: CN202211558391.X An energy-saving and environmentally friendly electrolytic hydrogen production system and electrolytic hydrogen production method, which includes: a cooler, a high-level tank, raw water transportation equipment, an electrolyzer, an oxygen circulation pump, an oxygen-liquid separator, a hydrogen circulation pump, and a hydrogen gas-liquid separator; the anode outlet and the cathode outlet of the electrolyzer are directly connected to the corresponding oxygen-liquid separator and hydrogen gas-liquid separator. In this way, the load of the gas-liquid separator is large, which greatly affects the gas-liquid separation effect, makes the working efficiency of the entire hydrogen production system low, and leads to a long separation time and the risk of incomplete separation. The gas phase and the liquid phase have great differences in flow characteristics and physical properties. If the gas-liquid mixture directly enters the downstream pipeline and equipment, it will cause damage to the equipment, especially the mixed two-phase flow of oxygen and alkali solution, which will cause extremely serious scouring and corrosion to the pipeline.

[0005] In view of the above, it is necessary to propose a pre-separation system for an electrolytic hydrogen production device based on the gravity separation principle to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects in the prior art and provide a pre-separation system for an electrolytic hydrogen production device based on the gravity separation principle.

[0007] To achieve the above-mentioned purpose, the technical solution of the present invention is as follows: a pre-separation system for an electrolytic hydrogen production device based on the principle of gravity separation, comprising an electrolytic cell and a gas-liquid separator, wherein a pre-separator is arranged on a material pipeline entering the gas-liquid separator from the electrolytic cell, the pre-separator having a vertically arranged cylindrical shell, a mixture inlet and a liquid outlet being arranged at the lower portion of the pre-separator, a gas outlet being arranged at the top of the pre-separator, the mixture inlet being connected to the outlet end of the electrolytic cell through a material pipeline, the liquid outlet being connected to a liquid phase in the gas-liquid separator through a liquid pipeline, and the gas outlet being connected to a gas phase at the top of the gas-liquid separator through a gas pipeline.

[0008] Furthermore, the mixed material inlet and the liquid outlet of the pre-separator are respectively arranged on both sides of the pre-separator.

[0009] Furthermore, there is at least one mixed material inlet, and when multiple mixed material inlets are provided, they can be arranged in sequence from low to high, and each mixed material inlet is connected to each outlet end of the electrolytic cell in sequence.

[0010] Furthermore, the cylindrical shell is cylindrical, and the ratio of the height to the diameter of the cylindrical shell is 15~25:1.

[0011] Furthermore, a spiral guide vane is provided at the lower part of the cylindrical shell, so that the gas-liquid mixture forms a swirling centrifugal motion inside the cylindrical shell under the guidance of the guide vane.

[0012] Furthermore, the surface of the guide plate is covered with a nano-lyophobic coating that accelerates the aggregation of droplets, and the nano-lyophobic coating makes the contact angle of the droplets greater than 150°.

[0013] Furthermore, a conical expansion cavity is provided in the middle of the cylindrical shell.

[0014] Furthermore, an ultrasonic array module for breaking up entrained droplets is installed on the inner wall of the expansion cavity, and the ultrasonic array module emits high-frequency vibration waves with a vibration frequency of 20-40 kHz.

[0015] Furthermore, a honeycomb rectifier is provided on the top of the cylindrical shell, and an electrostatic defoaming module is provided on the upper side of the honeycomb rectifier.

[0016] Furthermore, the honeycomb rectifier is made of titanium alloy, with a pore size of 1-3 mm and a thickness of 50-150 mm; the voltage of the electrostatic defoaming module is 5 kV and the inter-electrode spacing is 10 mm.

[0017] The advantages and beneficial effects of the present invention are: 1. A pre-separator is innovatively added to the material conveying pipeline from the electrolyzer to the gas-liquid separator. The pre-separator cleverly uses the principle of gravity separation and achieves efficient operation with its unique and exquisite structural design. It adopts a vertical cylindrical shell, with the mixed material inlet and liquid outlet precisely set at the bottom, and the gas outlet at the top. This layout can perform preliminary separation of gas and liquid in a very short time, greatly reducing the workload of the subsequent gas-liquid separator, significantly improving the overall separation efficiency, and laying a solid foundation for the efficient operation of the entire electrolytic hydrogen production process.

[0018] 2. The cylindrical shell adopts a cylindrical design, and the ratio of its height to diameter is controlled between 15-25:1. This carefully planned slender structure effectively prolongs the residence time of gas and liquid in the shell, making the gas-liquid separation process more complete and thorough. At the same time, a spiral guide vane is set at the bottom of the shell to guide the gas-liquid mixture to form a cyclonic centrifugal motion, further significantly enhancing the gas-liquid separation effect, and doubly ensuring the high efficiency of separation from the physical structure and motion principle.

[0019] 3. A conical expansion chamber is set in the middle of the pre-separator, which is used to effectively slow down the gas-liquid flow rate and create favorable conditions for further separation of gas and liquid. The ultrasonic array module installed on the inner wall of the cavity emits high-frequency vibration waves with a frequency of 20-40kHz during operation, which can accurately break up the entrained droplets and make the output gas purer. At the top of the shell, it is equipped with a honeycomb rectifier made of titanium alloy with an aperture of 1-3mm and a thickness of 50-150mm, which can effectively regulate the airflow; the electrostatic defoaming module working with it has a voltage set to 5kv and an inter-electrode spacing of 10mm, which can capture micron-sized droplets and efficiently remove tiny liquid foam, further improving the purity of the gas and ensuring the high-quality output of hydrogen in all directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic flow diagram of a pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle of the present invention; Figure 2 Schematic diagram of the external structure of the pre-separator in Embodiment 1 of the present invention; Figure 3 It is a schematic diagram of the structure in which a guide vane is arranged on the lower side of the pre-separator in the present invention; Figure 4 It is a structural exploded view of a pre-separator provided with guide vanes in the present invention; Figure 5 It is a structural schematic diagram of setting an expansion cavity portion for the pre-separator structure in the present invention; In the figure: 1. electrolytic cell; 2. gas-liquid separator; 3. material pipeline; 4. pre-separator; 5. cylindrical shell; 6. mixture inlet; 7. liquid outlet; 8. gas outlet; 9. outlet end; 10. liquid pipeline; 11. gas pipeline; 12. guide plate; 13. expansion chamber; 14. ultrasonic array module; 15. honeycomb rectifier; 16. electrostatic defoaming module. DETAILED DESCRIPTION

[0021] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0022] Implementation 1: A pre-separation system of an electrolytic hydrogen production device based on the principle of gravity separation comprises an electrolytic cell 1 and a gas-liquid separator 2. A pre-separator 4 is arranged on a material pipeline 3 where the electrolytic cell 1 enters the gas-liquid separator 2. The pre-separator 4 has a vertically arranged cylindrical shell 5, which is cylindrical, and the ratio of the height to the diameter of the cylindrical shell 5 is 15-25:1. After the gas-liquid mixture enters the pre-separator 4 from the mixture inlet 6, due to the action of gravity, the liquid with a higher density begins to flow downward, while the hydrogen and oxygen mixed gas with a lower density moves upward. Inside the pre-separator 4, the gas-liquid separation process is not a simple natural sedimentation, but is accelerated based on the gravity separation principle and the fluid mechanics principle. Thereby improving the gas-liquid separation efficiency.

[0023] In actual use, the hydrogen branch and the oxygen branch in the electrolytic hydrogen production system can be respectively provided with a pre-separator 4, such as Figure 1 As shown, two branches come out of the electrolytic cell 1, the upper side is the oxygen branch and the lower side is the hydrogen branch. The material in the oxygen branch is a gas-liquid mixture of oxygen and alkali liquid, and the material in the hydrogen branch is a mixture of hydrogen and alkali liquid. The two materials enter the corresponding pre-separator 4 for separation. In this embodiment, the pre-separator 4 arranged between the electrolytic cell 1 and the gas-liquid separator 2 plays a role in reducing the load of the gas-liquid separator 2 and effectively improving the gas-liquid separation effect. In this embodiment, a cylindrical shell 5 with a relatively large aspect ratio is used, which greatly increases the material residence time and promotes gas-liquid separation. The principle of gravity separation is used to separate the alkali liquid and the gas from each other, and the separated materials are connected and sent to different positions of the gas-liquid separator 2, and the pre-separation effect is better.

[0024] Specifically, in this embodiment, the diameter of the gas-liquid separator 2 in the hydrogen branch is 325 mm, and its height is 6500 mm; meanwhile, the diameter of the gas-liquid separator 2 in the oxygen branch is 275 mm, and its height is 6500 mm.

[0025] like Figure 2As shown, a mixture inlet 6 and a liquid outlet 7 are provided at the lower portion of the pre-separator 4, and a gas outlet 8 is provided at the top of the pre-separator 4. The mixture inlet 6 is connected to the outlet end 9 of the electrolytic cell 1 through a material pipeline 3, the liquid outlet 7 is connected to the liquid phase in the gas-liquid separator 2 through a liquid pipeline 10, and the gas outlet 8 is connected to the top gas phase of the gas-liquid separator 2 through a gas pipeline 11.

[0026] The mixed material inlet 6 and the liquid outlet 7 of the pre-separator 4 are respectively arranged on both sides of the pre-separator 4, and preferably, as Figure 2 As shown, the position of the mixture inlet 6 is higher than the liquid outlet 7. There is at least one mixture inlet 6, and when multiple mixture inlets 6 are provided, they are arranged in sequence from low to high, and each mixture inlet 6 is connected to each outlet port 9 of the electrolytic cell 1 in sequence. It can be understood that the number of mixture inlets 6 is set according to the number of outlet ports 9 of the electrolytic cell 1, and the number can be increased or decreased according to actual conditions. The number of settings is not limited. This embodiment takes three settings as an example.

[0027] Embodiment 2: In the technology of the first embodiment, further, a spiral guide vane 12 is provided at the lower part of the cylindrical shell 5, so that the gas-liquid mixture forms a swirling centrifugal motion inside the cylindrical shell 5 under the guidance of the guide vane 12. Specifically, Figure 3 , 4 As shown, a spiral guide vane 12 is arranged on the lower side of the inner part of the cylindrical shell 5, and the guide vane 12 adopts a double spiral guide vane 12. The guide vane 12 adopts an inner 45° inclination angle and is staggered, forcing the gas-liquid mixture to form a swirling centrifugal motion in the cylindrical shell 5, thereby forming a centrifugal separation effect on the gas-liquid mixture. The heavier liquid adheres to the wall and rotates and falls, and the lighter gas gathers in the middle and rises. In this embodiment, the feeding direction of the mixed material inlet 6 is preferably along the tangential direction of the cylindrical shell 5. After the gas-liquid mixed material enters along the tangential direction, the liquid is in a state of rotating and falling flow under the collision and diversion with the guide vane 12 and the inner wall of the cylindrical shell 5, thereby utilizing the principle of centrifugal separation to enhance the separation effect of gas and liquid. And the feeding position of the mixed feed port is fed at the interval between the two guide vanes 12.

[0028] Furthermore, the surface of the guide plate 12 is covered with a nano-lyophobic coating that accelerates the aggregation of droplets, and the nano-lyophobic coating makes the contact angle of the droplets greater than 150°. In actual use, the nano-lyophobic coating can be a fluorine-containing polymer, such as a fluorine-containing coating such as perfluoropolyether of a nano-lyophobic coating material. Fluorine atoms have the characteristics of high electronegativity and small atomic radius, which makes the surface energy of fluorine-containing polymers extremely low and have excellent hydrophobic and oleophobic properties. It can also be an inorganic nanomaterial. Inorganic nanoparticles such as silica and alumina are often used to prepare nano-lyophobic coatings. These inorganic nanoparticles can form a nanoscale rough structure on the surface of an object through processes such as the sol-gel method, and then combined with surface modification treatment to make it have lyophobic properties.

[0029] After the liquid rotates and falls to the bottom, it flows out from the liquid outlet 7. An adjustable vortex suppression baffle is arranged at the inner bottom, and the opening is adjusted by an external handle to control the smoothness of the bottom liquid flow.

[0030] Embodiment three: Further, such as Figure 5 As shown, a conical expansion cavity 13 is provided in the middle of the cylindrical shell 5. The flow velocity is reduced by a sudden change in the cross-sectional area, and secondary separation is achieved by utilizing the inertial effect. When the rising gas reaches the expansion cavity 13, the velocity drops significantly, thereby giving time for the entrained droplets in the gas to fall. Furthermore, an ultrasonic array module 14 for breaking the entrained droplets is installed on the inner wall of the expansion cavity 13. The ultrasonic array module 14 emits high-frequency vibration waves with a vibration frequency of 20-40kHz. When the airflow rises, the ultrasonic array module 14 can be used to break the bubbles and avoid the generation of foam in the cylindrical shell 5. The high-frequency vibration of the ultrasonic wave can break the bubbles on the surface of the liquid, causing them to break and release to the surface of the liquid, thereby achieving the effect of defoaming. The focusing characteristics of the ultrasonic wave enable it to generate high energy in a specific area, and it is also convenient to decompose the accumulated bubbles. The setting of the ultrasonic array module is different from the chemical defoaming method in the prior art. Chemical reagents do not need to be added, thereby avoiding the contamination of the separated alkali solution and facilitating the recycling of the alkali solution. The ultrasonic array module 14 can achieve a good defoaming effect, thereby preventing the airflow from carrying the droplets upward.

[0031] Furthermore, a honeycomb rectifier 15 is provided on the top of the cylindrical shell 5, and an electrostatic defoaming module 16 is provided on the upper side of the honeycomb rectifier 15. The honeycomb rectifier 15 can suppress turbulence and adsorb liquid films on the gas; the electrostatic defoaming module 16 can capture micron-sized droplets, thereby enhancing the gas-liquid separation effect. The function of the rectifier 15 is to make the gas flow more smoothly and reduce gas turbulence. At the same time, the function of the electrostatic defoaming module 16 is to capture small droplets to achieve a better gas-liquid separation effect. Electrostatic defoaming utilizes the adsorption effect of static charges to allow small droplets to be adsorbed on the surface of the module, thereby reducing the outflow of gas with liquid. The honeycomb rectifier 15 is composed of many hexagonal micropores, which can promote more complete gas flow, reduce resistance, and may help the liquid be brought to the defoaming module. Specifically, the honeycomb rectifier 15 is made of titanium alloy, which has good corrosion resistance, and has a pore size of 1-3 mm and a thickness of 50-150 mm; the voltage of the electrostatic defoaming module 16 is 5 kV, and the inter-electrode spacing is 10 mm.

[0032] The specific process control method of this system is: 1. Ultrasonic-electrostatic synergistic defoaming strategy, through parameter linkage control, specifically, when the gas phase moisture content monitoring value is greater than 5%, start the ultrasonic atomizer (power density 0.5W / cm²) to break the bubbles or foam formed inside. Simultaneously increase the voltage of the electrostatic module to 7kV to enhance the electric field adsorption force. Safety protection: When the moisture content is greater than 10%, the emergency discharge procedure is triggered, the outlet valve is closed, and the liquid is directly discharged to the main separator through the bypass.

[0033] 2. Liquid level-flow coupling regulation, collect bottom liquid level data in real time through the liquid level meter (target value: 300±10mm). Calculate the valve opening correction through the PID algorithm. Output 4-20mA signal to drive the proportional valve; establish a suitable liquid level at the bottom of the cylindrical shell 5.

[0034] The system sets a three-stage separation module of spiral centrifugal layer + conical expansion cavity 13 + honeycomb rectification layer inside the pre-separator 4, breaking through the traditional single gravity separation mode, adding centrifugal separation, ultrasonic defoaming, and electrostatic defoaming modules 16, so that the system can maintain a high separation effect.

[0035] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A pre-separation system for an electrolytic hydrogen production device based on the gravity separation principle, comprising an electrolytic cell (1) and a gas-liquid separator (2), characterized in that: A pre-separator (4) is arranged on a material pipeline (3) from an electrolytic cell (1) into a gas-liquid separator (2). The pre-separator (4) has a vertically arranged cylindrical shell (5). A mixed material inlet (6) and a liquid outlet (7) are arranged at the bottom of the pre-separator (4). A gas outlet (8) is arranged at the top of the pre-separator (4). The mixed material inlet (6) is connected to an outlet end (9) of the electrolytic cell (1) through the material pipeline (3). The liquid outlet (7) is connected to a liquid phase in the gas-liquid separator (2) through a liquid pipeline (10). The gas outlet (8) is connected to a gas phase at the top of the gas-liquid separator (2) through a gas pipeline (11).

2. According to the pre-separation system of the electrolytic hydrogen production device based on the gravity separation principle of claim 1, it is characterized in that: The mixed material inlet (6) and the liquid outlet (7) of the pre-separator (4) are respectively arranged on both sides of the pre-separator (4).

3. The pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle according to claim 2 is characterized in that: There is at least one mixed material inlet (6), and each mixed material inlet (6) is connected to each outlet end (9) of the electrolytic cell (1) in sequence.

4. The pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle according to claim 3 is characterized in that: The cylindrical shell (5) is cylindrical, and the ratio of the height to the diameter of the cylindrical shell (5) is 15-25:

1.

5. The pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle according to claim 1 is characterized in that: A spiral guide vane (12) is provided at the lower portion of the cylindrical shell (5), so that the gas-liquid mixture forms a swirling centrifugal motion inside the cylindrical shell (5) under the guidance of the guide vane (12).

6. The pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle according to claim 5 is characterized in that: The surface of the guide plate (12) is covered with a nano-lyophobic coating that accelerates the aggregation of liquid droplets, and the nano-lyophobic coating makes the contact angle of the liquid droplets greater than 150°.

7. The pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle according to claim 1 is characterized in that: A conical expansion cavity (13) is provided in the middle of the cylindrical shell (5).

8. The pre-separation system of the electrolytic hydrogen production device based on the gravity separation principle according to claim 7 is characterized in that: An ultrasonic array module (14) for breaking up entrained liquid droplets is installed on the inner wall of the expansion cavity (13); the ultrasonic array module (14) emits high-frequency vibration waves, the vibration frequency of which is 20-40 kHz.

9. The pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle according to claim 1, characterized in that: A honeycomb rectifier (15) is provided on the top of the cylindrical shell (5), and an electrostatic defoaming module (16) is provided on the upper side of the honeycomb rectifier (15).

10. The pre-separation system of an electrolytic hydrogen production device based on the gravity separation principle according to claim 9, characterized in that: The honeycomb rectifier (15) is made of titanium alloy, has a pore size of 1-3 mm, and a thickness of 50-150 mm; the voltage of the electrostatic defoaming module (16) is 5 kV, and the inter-electrode spacing is 10 mm.

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