阅读说明：本技术 维持碱性电解系统液位平衡及抑制串气风险的装置和方法 (Device and method for maintaining liquid level balance of alkaline electrolysis system and inhibiting gas leakage risk ) 是由 杨福源 古俊杰 李洋洋 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种维持碱性电解系统液位平衡及抑制串气风险的装置和方法,该方法包括在碱性电解系统中的两个气液分离器之间的U型管上安装用于抑制串气风险的安全装置。所述安全装置抑制碱性电解系统中的两个气液分离器串气风险的方式包括减缓U型管中液体流动速度、增加U型管中液体流动路程、减少U型管中液体通过安全装置流量中的至少一种。本发明可以有效在电解功率发生变化时有效避免一侧气液分离器中的碱液携带氢气或氧气在压力的作用下流入另一侧,进而避免液位平衡被打破而导致的串气风险,解决波动性可再生能源离网制氢下的安全性问题,提高碱性电解系统的离网制氢安全性能。(The invention discloses a device and a method for maintaining liquid level balance of an alkaline electrolysis system and inhibiting gas leakage risks. The mode of the safety device for inhibiting the risk of gas leakage of the two gas-liquid separators in the alkaline electrolysis system comprises at least one of slowing down the liquid flowing speed in the U-shaped pipe, increasing the liquid flowing path in the U-shaped pipe and reducing the flow of the liquid in the U-shaped pipe passing through the safety device. The invention can effectively prevent the alkali liquor in the gas-liquid separator at one side from flowing into the other side under the action of pressure when the electrolytic power changes, thereby avoiding the risk of gas cross caused by breaking the liquid level balance, solving the safety problem of the fluctuating renewable energy source under the off-grid hydrogen production, and improving the safety performance of the off-grid hydrogen production of the alkaline electrolytic system.)

1. A method for suppressing the risk of gas cross-over in an alkaline electrolysis system, characterized in that it comprises mounting a safety device for suppressing the risk of gas cross-over on a U-tube (12) between two gas-liquid separators (11) in an alkaline electrolysis system (1).

2. A method for suppressing the risk of cross-gassing in an alkaline electrolysis system according to claim 1, wherein the means for suppressing the risk of cross-gassing by the safety device comprises at least one of slowing the liquid flow rate in the U-tubes (12), increasing the liquid flow path in the U-tubes (12), and reducing the liquid flow rate in the U-tubes (12) at the location of the safety device.

3. A method for suppressing the risk of cross-gassing in an alkaline electrolysis system according to claim 2, characterized in that the safety device is a flow restriction device (2) for suppressing an excessively rapid flow of liquid in the U-tube, which flow restriction device (2) comprises a closed chamber (21), a communicating tube (22) having one end projecting into the closed chamber (21); one end of the communicating pipe (22) extending into the closed cavity (21) is closed, and at least one orifice (23) is arranged on the side surface.

4. A method for suppressing the risk of cross-gassing in alkaline electrolysis systems according to claim 3, characterized in that the number of communicating tubes (22) in the flow restriction device (2) is two and they are symmetrically arranged on the closed chamber (21).

5. A method for suppressing the risk of gas cross-over in an alkaline electrolysis system according to claim 4, wherein at least one partition (24) separating two communicating tubes (22) is further provided in the closed chamber (21), and the partition (24) is also provided with an orifice (23).

6. The method for suppressing the air-crossing risk of the alkaline electrolysis system according to claim 5, wherein the number of the partition plates (24) is one layer, the diameter of the throttle hole (23) is 2mm, the number of the throttle holes (23) on the partition plates (24) is 25, and the number of the throttle holes (23) on the communicating tubes (22) is 40.

7. A method for suppressing the risk of blow-by in an alkaline electrolysis system according to any of claims 1-6, wherein the flow restriction device (2) is installed in the middle of the U-tube (12).

8. An apparatus for maintaining liquid level balance and suppressing gas cross-over risk in an alkaline electrolysis system, characterized by a flow restriction apparatus (2) as claimed in any one of claims 3 to 6.

9. An alkaline electrolysis system for maintaining liquid level balance and inhibiting gas leakage risk is characterized by comprising an alkaline electrolysis system (1) with a U-shaped pipe (12) and a device which is arranged on the U-shaped pipe (12) and used for maintaining the liquid level balance of the alkaline electrolysis system and inhibiting the gas leakage risk; the device for maintaining the liquid level balance of the alkaline electrolysis system and inhibiting the risk of gas leakage is the flow limiting device (2) as set forth in any one of claims 3-6.

Technical Field

The invention relates to the technical field of hydrogen production by water electrolysis, in particular to a device and a method for maintaining liquid level balance of an alkaline electrolysis system and inhibiting gas leakage risks.

Background

Alkaline electrolysis systems typically employ a 30% by mass KOH solution as the electrolyte and a nickel mesh as the electrode to perform electrolysis, producing hydrogen and oxygen at the cathode and anode, respectively. The electrode reaction of the alkaline electrolysis system is as follows:

to prevent hydrogen and oxygen mixing during electrolysis and short circuits caused by direct contact of the electrodes, a separator is often used to separate the cathode and anode cells. Asbestos dust is easily carcinogenic, and as a result of the development, diaphragms made of organic substrates with hydrophilic additives, such as Zirfon diaphragms from AGFA, germany, have been widely used.

As can be seen from the above, since 1 mole of water is decomposed to generate 1 mole of hydrogen and 0.5 mole of oxygen, in order to maintain the pressure balance between the hydrogen side and the oxygen side, it is necessary to adjust the membrane control valves on both sides, and to perform pressure control on the oxygen side or liquid level control on the oxygen side. Meanwhile, in order to ensure that the pressure difference between the gas phase and the liquid phase can be reflected by the liquid level difference of the gas-liquid separator, a U-shaped pipe (communicating vessel) is used to connect the gas-liquid separators at two sides of the existing alkaline electrolysis system, as shown in fig. 1.

However, when the hydrogen production by electrolyzing water in the alkaline electrolysis system is realized by using renewable energy sources, the energy power provided for the alkaline electrolysis system fluctuates due to the intermittent, periodic and regional renewable energy sources such as wind power. When the electrolysis power is changed, the hydrogen production amount in the electrolysis process is as follows: the oxygen production rate was 2:1, and the pressure on the hydrogen side and the oxygen side fluctuated. Specifically, as power increases, the hydrogen side pressure increases faster, causing the caustic in the hydrogen side gas-liquid separator to flow under pressure to the oxygen side gas-liquid separator; when the power is reduced, the hydrogen side pressure is reduced more rapidly without changing the opening of the membrane regulating valve, so that the alkali liquor in the gas-liquid separator on the oxygen side flows into the gas-liquid separator on the hydrogen side under the action of the pressure.

Therefore, in the U-shaped pipe, when the electrolysis power changes, the alkali liquor in the gas-liquid separator on one side may flow into the other side along with hydrogen or oxygen under the action of pressure, and further the liquid level balance is broken, so that the risk of gas cross is generated, and the potential safety hazard is caused.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is as follows: the device and the method for maintaining the liquid level balance of the alkaline electrolysis system and inhibiting the risk of gas cross are provided to overcome the defects that the liquid level balance in the U-shaped pipe is broken and the risk of gas cross is generated when the electrolysis power of the alkaline electrolysis system is changed in the prior art.

A method for inhibiting the gas leakage risk of an alkaline electrolysis system comprises the step of installing a safety device for inhibiting the gas leakage risk on a U-shaped pipe between two gas-liquid separators in the alkaline electrolysis system.

The mode of the safety device for inhibiting the risk of gas leakage of the two gas-liquid separators in the alkaline electrolysis system comprises at least one of slowing down the liquid flowing speed in the U-shaped pipe, increasing the liquid flowing path in the U-shaped pipe and reducing the flow of the liquid in the U-shaped pipe passing through the safety device. The safety devices include, but are not limited to, damping devices, cushioning devices, current limiting devices, and the like.

The safety device is preferably a flow limiting device for inhibiting the liquid in the U-shaped pipe from flowing too fast, the flow limiting device comprises a closed cavity, and one end of the flow limiting device extends into a communicating pipe of the closed cavity; one end of the communicating pipe extending into the closed cavity is closed, and at least one throttling hole is formed in the side face of the communicating pipe.

The flow limiting device is characterized in that the number of the communicating pipes is two, and the communicating pipes are symmetrically arranged on the closed cavity.

At least one layer of partition board for separating the two communicating pipes is arranged in the closed cavity, and the partition board is also provided with an orifice.

The quantity of baffle is one deck, and the diameter of orifice is 2mm, and the quantity of orifice on the baffle is 25, and the quantity of orifice on the communicating pipe is 40.

The flow limiting device is arranged in the middle of the U-shaped pipe.

The device for maintaining the liquid level balance of the alkaline electrolysis system and inhibiting the risk of gas leakage is the flow limiting device.

The alkaline electrolysis system comprises an alkaline electrolysis system with a U-shaped pipe and a device which is arranged on the U-shaped pipe and used for maintaining the liquid level balance of the alkaline electrolysis system and inhibiting the gas leakage risk, wherein the device used for maintaining the liquid level balance of the alkaline electrolysis system and inhibiting the gas leakage risk is the flow limiting device.

The technical scheme of the invention has the following advantages:

1. according to the method for inhibiting the gas leakage risk of the alkaline electrolysis system, the safety device for inhibiting the gas leakage risk is arranged on the U-shaped pipe, so that the alkali liquor in the gas-liquid separator at one side can be effectively prevented from carrying hydrogen or oxygen to flow into the other side under the action of pressure when the electrolysis power is changed, the gas leakage risk caused by breaking of liquid level balance is further avoided, the safety problem of the fluctuating renewable energy under the off-grid hydrogen production is solved, and the off-grid hydrogen production safety performance of the alkaline electrolysis system is improved.

2. The device for maintaining the liquid level balance of the alkaline electrolysis system and inhibiting the risk of gas leakage provided by the invention can effectively reduce the flow rate of the alkaline liquid in the U-shaped pipe, better maintain the liquid level balance of the alkaline electrolysis system, further provide more sufficient time for adjusting the pressure for the alkaline electrolysis system, and achieve the purpose of inhibiting the risk of gas leakage, and has an obvious effect.

3. The structure of the flow limiting device is further optimized, and under the optimized structure, the purpose of slowing down the flowing speed of the liquid in the U-shaped pipe can be effectively achieved, and the requirement of restraining the gas leakage risk in an alkaline electrolysis system is completely met; compared with the mode of increasing the liquid flow path in the U-shaped pipe and reducing the liquid flow at the position of the safety device in the U-shaped pipe, the structure is better, stable and reliable, the cost is low, and the U-shaped pipe is extremely suitable for popularization and application.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic view of the structure of an alkaline electrolysis system according to the present invention;

FIG. 2 is a schematic view of a current limiting device according to the present invention;

FIG. 3 is a schematic structural view of a U-shaped pipe after the flow limiting device is installed.

Description of reference numerals:

1-alkaline electrolysis system, 2-current limiting device;

11-a gas-liquid separator and 12-a U-shaped pipe;

21-closed chamber, 22-communicating pipe, 23-orifice and 24-clapboard.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

A method for inhibiting the risk of gas cross-over of an alkaline electrolysis system comprises the step of installing a safety device for inhibiting the risk of gas cross-over on a U-shaped pipe 12 between two gas-liquid separators 11 in the alkaline electrolysis system 1.

According to the invention, the safety device for inhibiting the gas leakage risk is arranged on the U-shaped pipe, so that the alkali liquor in the gas-liquid separator at one side can be effectively prevented from carrying hydrogen or oxygen to flow into the other side under the action of pressure when the electrolytic power is changed, the gas leakage risk caused by breaking of liquid level balance is further avoided, the safety problem of the fluctuating renewable energy under the off-grid hydrogen production is solved, and the off-grid hydrogen production safety performance of the alkaline electrolytic system is improved.

In the present invention, there are many ways to achieve the above-described suppression of the risk of gas leakage, as long as it is possible to prevent all the liquid in all the U-shaped tubes from being forced into any one of the gas-liquid separators 11. Specifically, the manner of suppressing the risk of gas cross-over between the two gas-liquid separators 11 in the alkaline electrolysis system 1 by the safety device includes at least one of slowing down the flow speed of the liquid in the U-shaped pipe 12, increasing the flow path of the liquid in the U-shaped pipe 12, and reducing the flow rate of the liquid in the U-shaped pipe 12 at the position where the safety device is located.

When the mode of slowing down the liquid flowing speed in the U-shaped pipe 12 is selected, a damping device, a flow limiting device and the like can be arranged on the U-shaped pipe 12, the flowing time of the liquid in the U-shaped pipe 12 is prolonged under the same path by slowing down the liquid flowing speed, and the purpose of restraining the risk of air leakage is further achieved.

For another example, when the flow path of the liquid in the U-shaped pipe 12 is selected to be increased, a buffer device, such as a spiral coil, may be additionally disposed on the U-shaped pipe 12, so as to increase the flow path of the liquid, and even if the flow speed of the liquid is not changed, the time for all the liquid to flow into the gas-liquid separator may be increased, so as to achieve the purpose of suppressing the risk of gas cross-flow.

For another example, a stop valve may be used as a safety device to reduce the liquid flow passing through the position of the stop valve in the U-shaped pipe 12, that is, when the liquid flow passing through the safety device reaches a certain threshold, the stop valve is directly started to close the U-shaped pipe 12, so as to achieve the purpose of suppressing the risk of air leakage.

The safety device is selected to increase the liquid flow path in the U-tube 12, which increases the volume of the safety device, and the safety device is selected to decrease the liquid flow through the U-tube 12 at the position of the stop valve, which is relatively costly. The safety device according to the invention is therefore preferably a flow restriction device 2 which inhibits an excessively rapid flow of liquid in the U-tube, as shown in figure 3.

The flow limiting device 2 has various structures, and can be any structure which can achieve the purpose of limiting the flow rate. In the present embodiment, a flow-limiting device 2 with a specific structure is provided, as shown in fig. 2, specifically, the flow-limiting device 2 includes a closed cavity 21, and a communicating pipe 22 having one end extending into the closed cavity 21; one end of the communicating pipe 22 extending into the closed cavity 21 is closed, and at least one orifice 23 is arranged on the side surface.

The number of the communicating pipes 22 in the flow limiting device 2 can be one or two; in the case of one, one of the two joints in the middle of the U-shaped tube 12 is communicated with the communicating tube 22, and the other joint can be directly communicated with the closed cavity 21. The liquid in the U-shaped pipe 12 is decelerated and turned after being blocked by the closed end of the communicating pipe 22 and the wall of the closed cavity 21, and the purpose of deceleration can be effectively achieved only by communicating the U-shaped pipes 12 at the two ends of the flow limiting device 2 through the throttling hole 23.

In order to achieve a better speed reduction effect, better meet the liquid level balance of the alkaline electrolysis system and inhibit the risk of gas leakage, the number of the communicating pipes 22 in the flow limiting device 2 is two, and the two communicating pipes are symmetrically arranged on the closed cavity 21. One of the communicating pipes 22 is a liquid inlet pipe, and the other communicating pipe 22 is a liquid outlet pipe, as shown in fig. 2; and at least one layer of partition plate 24 for separating the two communicating pipes 22 is arranged in the closed cavity 21, and the partition plate 24 is also provided with an orifice 23. The diameter, number and position of the orifices 23 in the present invention can be adjusted accordingly to the power of the alkaline electrolysis system 1.

For the U-shaped tube 12 with an outer diameter of 25mm and an inner diameter of 18mm in the present invention, the optimized structure of the flow restriction device 2 in the present embodiment is as follows: the number of the partition plates 24 in the closed cavity 21 is set to one layer, the diameter of the throttle holes 23 is set to 2mm, the number of the throttle holes 23 on the partition plates 24 is set to 25, and the number of the throttle holes 23 on the communicating pipes 22 is set to 40. Through the optimized arrangement, the purposes of maintaining liquid level balance and inhibiting gas leakage risks of the alkaline electrolysis system can be better achieved. Through detection, the following results are obtained: with the above structural arrangement, the object of the present invention can be achieved even if the power fluctuates at a speed of 2%/s in the range of 10% to 150%.

Example 2

The structure of a device for maintaining the liquid level balance of an alkaline electrolysis system and suppressing the risk of gas leakage is the same as that of the flow limiting device described in the above embodiment 1.

Example 3

An alkaline electrolysis system for maintaining liquid level balance and inhibiting gas leakage risk comprises the device for maintaining liquid level balance and inhibiting gas leakage risk of the alkaline electrolysis system in the embodiment 2, and the device is preferably arranged in the middle of a U-shaped pipe 12.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.