A system for detecting hydrogen concentration in oxygen at an outlet of an alkaline electrolyzer

Abstract

The utility model discloses a kind of hydrogen concentration detection systems in alkaline electrolytic cell outlet oxygen, belong to electrolytic cell technical field.The system includes: electrolytic cell, microporous membrane gas-liquid separator, cooling device and detection device;Electrolytic cell is provided with oxygen side outlet, oxygen side outlet is connected with microporous membrane gas-liquid separator, hydrogen, oxygen and lye are separated;One end of microporous membrane gas-liquid separator is connected with cooling device, separated gas is transported to detection device after temperature reduction and carries out hydrogen concentration detection in oxygen, the other end of microporous membrane gas-liquid separator is connected with alkali tank, separated lye is discharged to alkali tank and is recycled.The utility model optimizes existing electrolytic cell hydrogen detection technology, by configuring microporous membrane gas-liquid separator, the gas of electrolytic cell oxygen side outlet is directly detected concentration, reduce the hysteresis and error of the value of purity detector, timely judge the working state of alkaline electrolytic cell, improve the security of alkaline electrolytic water hydrogen production system.

Description

Technical Field

[0001] This application relates to the field of electrolytic cell technology, specifically to a system for detecting hydrogen concentration in oxygen at the outlet of an alkaline electrolytic cell. Background Technology

[0002] Hydrogen energy, as a core energy carrier for achieving deep decarbonization, has irreplaceable strategic value in fields such as chemical engineering, transportation, power, semiconductors, and metallurgy. Its high energy density, zero carbon emissions, and long-term storage capabilities are driving the global energy structure towards a green and low-carbon transformation. In the entire hydrogen energy industry chain, hydrogen production technology is crucial. Among them, alkaline electrolysis hydrogen production, with its mature, reliable, and cost-controllable advantages, has become a key technological path for absorbing fluctuating renewable energy sources such as photovoltaic and wind power. However, in the alkaline water electrolysis hydrogen production process, ion permeation on both sides of the hydrogen-oxygen membrane can lead to cross-mixing of product gases. Especially when the hydrogen volume concentration on the oxygen side exceeds the 4% explosion limit, it will cause significant safety hazards. Current national standards mandate that the hydrogen concentration in the oxygen during production must be strictly controlled below the 2% safety threshold.

[0003] For the safe operation of alkaline electrolyzers, it is necessary to monitor the hydrogen concentration in oxygen in real time. However, existing detection systems have some limitations: First, the detection sites are lagging. Purity analyzers are usually installed at the rear end of the gas-liquid separator, purification unit, and cooling device, far from the electrolyzer body, resulting in a slow system response and an inability to reflect the electrolyzer's operating status in real time. Second, in existing detection technologies, the sample gas still carries a small amount of alkaline solution after separation by the gas-liquid separator. When the system operates for a long time, the continuous accumulation of alkaline solution in the detection system will damage the detection instruments and affect the continuous monitoring of hydrogen concentration in oxygen.

[0004] Therefore, in order to solve the above problems, this utility model proposes a rapid detection system for hydrogen concentration in oxygen at the outlet of an alkaline electrolyzer. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a rapid detection system for hydrogen concentration in oxygen at the outlet of an alkaline electrolyzer. This system facilitates rapid detection of hydrogen concentration in oxygen at the alkaline electrolyzer and employs a microporous membrane gas-liquid separator, replacing traditional gravity settling or centrifugal separation devices. This results in extremely low alkali residue and complete isolation from water vapor interference. The technical problem this invention aims to solve and its objective is to overcome the limitations of existing technologies where the oxygen hydrogen detection instrument is connected after the gas-liquid separator, preventing direct detection of gas purity at the electrolyzer outlet and causing a lag in the measured hydrogen concentration. Furthermore, the use of a microporous membrane gas-liquid separator improves the separation efficiency and purity of the gas-liquid mixture, reduces the impact of alkali carried in the sample gas on the detection instrument, and provides a rapid detection system for hydrogen concentration in oxygen at the outlet of an alkaline electrolyzer, ensuring the safe and stable operation of the hydrogen production system.

[0006] The present invention adopts the following technical solution.

[0007] This utility model discloses a system for detecting hydrogen concentration in oxygen at the outlet of an alkaline electrolyzer, comprising: an electrolyzer, a microporous membrane gas-liquid separator, a cooling device, and a detection device; The electrolytic cell electrolyzes water to produce hydrogen and oxygen. The electrolytic cell is equipped with an oxygen side outlet, which is connected to a microporous membrane gas-liquid separator to separate hydrogen, oxygen and alkaline solution. One end of the microporous membrane gas-liquid separator is connected to a cooling device to lower the temperature of the separated gas before sending it to a detection device for detecting the hydrogen concentration in oxygen. The other end of the microporous membrane gas-liquid separator is connected to an alkali tank to discharge the separated alkali solution into the alkali tank for recovery.

[0008] Preferably, the electrolytic cell is equipped with an alkaline solution and an electrolysis device to electrolyze water to produce hydrogen and oxygen, and an oxygen-side outlet is provided at the top of the electrolytic cell.

[0009] Preferably, the oxygen-side outlet of the electrolytic cell is connected to a microporous membrane gas-liquid separator via a second valve, allowing alkaline solution and gas to be introduced into the microporous membrane gas-liquid separator, where the gas is separated for detection.

[0010] Preferably, the microporous membrane gas-liquid separator comprises: a gas-liquid mixture inlet, a microporous hydrophobic membrane, and a gas outlet; The oxygen-side outlet of the electrolyzer is connected to the gas-liquid mixture inlet. Oxygen and hydrogen are filtered through a microporous hydrophobic membrane and output from the gas outlet.

[0011] Preferably, the microporous membrane gas-liquid separator further includes: a microporous hydrophilic membrane and a liquid outlet; The oxygen-side outlet of the electrolyzer is connected to the gas-liquid mixture inlet, and the alkaline solution and water vapor are output from the liquid outlet through a microporous hydrophilic membrane.

[0012] Preferably, the liquid outlet is connected to the alkali tank to recover alkali solution and water vapor.

[0013] Preferably, the cooling device is connected to the alkali tank via a third valve to discharge the condensate that forms when the gas cools down into the alkali tank.

[0014] Preferably, the cooling device is connected to the detection device, and a fourth valve is installed on the pipeline between the cooling device and the detection device. The fourth valve is a pressure reducing valve. After the gas is output from the outlet of the cooling device, it passes through the fourth valve to reduce the pressure before entering the detection device for detection.

[0015] Preferably, a fifth valve is provided after the fourth valve. The fifth valve is a needle valve, and the gas flow rate is controlled by the fifth valve before entering the detection device for detection.

[0016] Preferably, a sixth valve is provided behind the detection device, through which the gas is vented.

[0017] Compared with the prior art, the beneficial effects of this utility model include at least the following: To address the technical problem in existing technologies for monitoring hydrogen concentration in oxygen, where the hydrogen concentration detector is connected after the gas-liquid separator, it is impossible to directly detect the gas purity at the electrolyzer outlet, resulting in a lag in the measured hydrogen concentration. This invention optimizes the existing hydrogen concentration detection technology in electrolyzers by configuring a microporous membrane gas-liquid separator to be directly connected to the oxygen-side outlet pipe of the electrolyzer. This facilitates direct concentration detection of the gas at the oxygen-side outlet of the electrolyzer, reduces the lag and error of the purity detector, allows for timely assessment of the alkaline electrolyzer's operating status, and improves the safety of the alkaline water electrolysis hydrogen production system. Furthermore, the microporous membrane gas-liquid separator is equipped with both hydrophobic and hydrophilic membranes, which can directly separate gas from alkaline solution. Compared with the gas-liquid separators configured in existing detection systems, the gas separated by the microporous membrane gas-liquid separator has higher purity and extremely low water vapor and alkaline solution content. Therefore, the back-end processing does not require water and alkali removal, which improves the separation efficiency and gas purity of the gas-liquid mixture, reduces the impact of alkaline solution carried in the sample gas on the detection instrument, and can quickly and efficiently detect the hydrogen concentration in the oxygen at the outlet of the electrolyzer, ensuring the safe and stable operation of the hydrogen production system. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a rapid detection system for hydrogen concentration in oxygen at the outlet of an alkaline electrolyzer, as proposed in this utility model. The attached diagram is labeled as follows: 1. Electrolytic cell; 2. First valve; 3. Alkali tank; 4. Second valve; 5. Microporous membrane gas-liquid separator; 6. Cooling device; 7. Third valve; 8. Fourth valve; 9. Fifth valve; 10. Detection device; 11. Sixth valve. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The embodiments described in this application are merely some embodiments of this utility model, and not all embodiments. Based on the spirit of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "a solution," "some solutions," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that solution or example is included in at least one solution or example of this invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same solution or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more solutions or examples.

[0024] like Figure 1 As shown, this utility model provides a system for detecting hydrogen concentration in oxygen at the outlet of an alkaline electrolyzer, comprising: an electrolyzer 1, a microporous membrane gas-liquid separator 5, a cooling device 6, and a detection device 10.

[0025] The electrolytic cell 1 is equipped with an alkaline solution and an electrolysis device for electrolyzing water to produce hydrogen and oxygen. The top of the electrolytic cell 1 is provided with an oxygen-side outlet, which is connected to the microporous membrane gas-liquid separator 5 through a second valve 4.

[0026] In the prior art, the electrolytic cell 1 is generally connected to a large gas-liquid separator through the first valve 2 to separate the alkali solution and gas in the whole system. The separated gas is then sent to a detection device to detect the hydrogen concentration in oxygen. However, the detection device is located far from the electrolytic cell body, which results in a longer gas path and detection time, and cannot reflect the operating status of the electrolytic cell in real time.

[0027] This application sets a branch at the oxygen-side outlet of the electrolytic cell 1 and connects it to the microporous membrane gas-liquid separator 5 via the second valve 4. A small amount of alkali solution and gas are introduced into the microporous membrane gas-liquid separator 5, and the gas is quickly separated for detection. This achieves the goal of setting the detection position at the outlet of the electrolytic cell 1, resulting in a shorter gas path and shorter analysis time. It can not only reflect the operating status of the electrolytic cell 1 in real time, but the microporous membrane separator 5 can also reduce the alkali and water vapor content in the gas, protecting the detection device 10.

[0028] The microporous membrane gas-liquid separator includes a hydrophilic membrane and a hydrophobic membrane. The oxygen-side outlet of the electrolytic cell 1 is connected to the microporous membrane gas-liquid separator 5, through which oxygen and hydrogen are separated from alkaline solution and water vapor.

[0029] Specifically, the microporous membrane gas-liquid separator is provided with a gas-liquid mixture inlet, a microporous hydrophobic membrane, a microporous hydrophilic membrane, a gas outlet, and a liquid outlet; The oxygen-side outlet of electrolytic cell 1 is connected to the gas-liquid mixture inlet. Oxygen and hydrogen are filtered through a microporous hydrophobic membrane and output from the gas outlet, while alkaline solution and water vapor are output from the liquid outlet through a microporous hydrophilic membrane.

[0030] Since the microporous hydrophobic membrane only allows gas to pass through, alkaline solution cannot pass through, and water vapor also cannot pass through due to the hydrophobicity of the microporous hydrophobic membrane.

[0031] The microporous hydrophobic membrane material includes, but is not limited to, polytetrafluoroethylene and polyvinylidene fluoride, and the microporous hydrophilic membrane material includes, but is not limited to, polysulfone and polyacrylonitrile.

[0032] The gas outlet of the microporous membrane gas-liquid separator 5 is connected to the inlet of the cooling device 6, and the liquid outlet is connected to the alkali tank 3. Hydrogen and oxygen separated by the microporous hydrophobic membrane in the microporous membrane gas-liquid separator 5 enter the cooling device 6. On the one hand, the gas temperature can be reduced to meet the requirements of the detection device 10. On the other hand, the residual water vapor in the hydrogen and oxygen can be cooled and condensed into water by the cooling device 6. The cooling device 6 is connected to the alkali tank 3 through the third valve 7 to discharge the condensate in the cooling device.

[0033] The alkaline solution separated by the hydrophilic membrane in the microporous membrane gas-liquid separator 5 is directly fed into the alkaline tank 3 through the liquid outlet for recovery.

[0034] The cooling device 6 is connected to the detection device 10, and a fourth valve 8 and a fifth valve 9 are sequentially installed on the pipeline between the cooling device 6 and the detection device 10.

[0035] The fourth valve 8 is a pressure reducing valve. After the gas exits from the outlet of the cooling device 6, it passes through the fourth valve 8 to reduce the pressure and then enters the fifth valve 9. The fifth valve 9 is a needle valve used to control the gas flow rate. After the separated gas passes through the fourth valve 8 and the fifth valve 9 to make the pressure and flow rate meet the detection requirements, it enters the detection device 10 for hydrogen concentration detection in oxygen. After the detection is completed, the gas is vented through the sixth valve 11.

[0036] Compared with the prior art, the beneficial effects of this utility model include at least the following: This invention addresses the technical problem in existing methods for monitoring hydrogen concentration in oxygen. The existing method connects the hydrogen concentration detector after the gas-liquid separator, making it impossible to directly detect the gas purity at the electrolyzer outlet, resulting in a lag in the measured hydrogen concentration. This system connects a microporous membrane gas-liquid separator directly to the oxygen outlet of the electrolyzer. The microporous membrane separator improves the separation efficiency and purity of the gas-liquid mixture, reduces the impact of alkaline solutions carried in the sample gas on the detector, and provides a system for detecting hydrogen concentration in oxygen at the outlet of an alkaline electrolyzer. This system enables rapid and efficient detection of hydrogen concentration in oxygen at the electrolyzer outlet, ensuring the safe and stable operation of the hydrogen production system.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A system for detecting hydrogen concentration in oxygen at the outlet of an alkaline electrolyzer, characterized in that, include: Electrolytic cell (1), microporous membrane gas-liquid separator (5), cooling device (6) and detection device (10); The electrolytic cell (1) electrolyzes water to produce hydrogen and oxygen. The electrolytic cell (1) is provided with an oxygen side outlet, which is connected to a microporous membrane gas-liquid separator (5) to separate hydrogen, oxygen and alkaline solution. One end of the microporous membrane gas-liquid separator (5) is connected to the cooling device (6) to cool the separated gas and then send it to the detection device (10) for detection of hydrogen concentration in oxygen. The other end of the microporous membrane gas-liquid separator (5) is connected to the alkali tank (3) to discharge the separated alkali liquid into the alkali tank (3) for recovery.

2. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 1, characterized in that, The electrolytic cell (1) is filled with alkali solution and an electrolysis device to electrolyze water to produce hydrogen and oxygen. An oxygen-side outlet is provided at the top of the electrolytic cell (1).

3. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 2, characterized in that, The oxygen-side outlet of the electrolytic cell (1) is connected to the microporous membrane gas-liquid separator (5) through the second valve (4). Alkali solution and gas are introduced into the microporous membrane gas-liquid separator (5), and the gas is separated out by the microporous membrane gas-liquid separator (5) for detection.

4. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 1, characterized in that, The microporous membrane gas-liquid separator (5) includes: a gas-liquid mixture inlet, a microporous hydrophobic membrane, and a gas outlet; The oxygen-side outlet of the electrolytic cell (1) is connected to the gas-liquid mixture inlet. Oxygen and hydrogen are filtered through a microporous hydrophobic membrane and output from the gas outlet.

5. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 3, characterized in that, The microporous membrane gas-liquid separator (5) further includes: a microporous hydrophilic membrane and a liquid outlet; The oxygen-side outlet of the electrolytic cell (1) is connected to the gas-liquid mixture inlet, and the alkaline solution and water vapor are output from the liquid outlet through the microporous hydrophilic membrane.

6. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 5, characterized in that, The liquid outlet is connected to the alkali tank (3) to recover alkali solution and water vapor.

7. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 1, characterized in that, The cooling device (6) is connected to the alkali tank (3) through the third valve (7) to discharge the condensate water that condenses when the gas is cooled into the alkali tank (3).

8. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 1, characterized in that, The cooling device (6) is connected to the detection device (10). A fourth valve (8) is installed on the pipeline between the cooling device (6) and the detection device (10). The fourth valve (8) is a pressure reducing valve. After the gas is output from the outlet of the cooling device (6), it passes through the fourth valve (8) to reduce the pressure and then enters the detection device (10) for detection.

9. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 8, characterized in that, A fifth valve (9) is provided behind the fourth valve (8). The fifth valve (9) is a needle valve. The gas flow rate is controlled by the fifth valve (9) and then enters the detection device (10) for detection.

10. The hydrogen concentration detection system for oxygen at the outlet of an alkaline electrolyzer according to claim 1, characterized in that, A sixth valve (11) is provided behind the detection device (10), and the gas is discharged through the sixth valve (11).

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