Device for PEM electrolyzed water gas collection and off-line detection of hydrogen in oxygen

Abstract

The utility model relates to the technical field of hydrogen production by electrolyzing water, and discloses a device for PEM electrolyzed water gas collection and off-line detection of hydrogen in oxygen, which comprises a water pump, a first pipeline, a first gas collection bottle, a second pipeline, a second gas collection bottle, a third pipeline and a container which are communicated in sequence. According to the utility model, the problems of complex equipment, poor flexibility and the like in the prior art are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen production by electrolysis of water, in particular to a device for collecting gas from PEM electrolysis of water and for off-line detection of hydrogen in oxygen. Background Art

[0002] PEM electrolysis uses a perfluorosulfonic acid proton exchange membrane as a solid electrolyte, effectively preventing electron transfer and ensuring that most hydrogen and oxygen are isolated at the anode and cathode, even under high pressure. However, a small amount of gas will inevitably leak. However, the H2 concentration threshold for explosion in the hydrogen and oxygen mixture after leakage is very low, at 4 vol%. Therefore, accurate monitoring of the hydrogen concentration in the oxygen on the anode side is essential. Furthermore, to cope with the various external operating environments of the PEM electrolyzer, the collection and detection equipment must also be flexible.

[0003] In order to monitor this safety issue, CN116103696A provides an online monitoring device and method for hydrogen in oxygen / oxygen in hydrogen of PEM water electrolysis. The device includes two sets of monitoring mechanisms, including a variety of devices and components, which can measure hydrogen in oxygen and oxygen in hydrogen online. The system can effectively remove acidic components and moisture in the produced gas. CN219010478U relates to a hydrogen collection device for water electrolysis hydrogen production, including a collection box, a filter box and a connecting pipe. The alkaline gas in the inner cavity of the filter box can be neutralized with the acidic gas doped in the hydrogen, thereby eliminating the acidic gas contained in the hydrogen, solving the problem that the collection device in the prior art does not remove the acidic gas doped in the hydrogen thoroughly. CN217869115U discloses a hydrogen collection device for water electrolysis hydrogen production equipment. By using an impurity removal device, the moisture and acidic gas contained in the hydrogen are removed before the hydrogen is collected, thereby improving the purity of the hydrogen entering the storage box. However, the equipment systems provided by the above technologies are relatively complex and lack flexibility and adaptability to various application scenarios. Most of them use instruments such as gas flow meters to detect hydrogen in oxygen, which may have problems with insufficient accuracy and pose certain safety hazards. If high-precision detection equipment is directly connected to the electrolyzer, when the gas production is too large, there is a risk of impact and damage to the detection equipment, which reduces the service life of the high-precision equipment.

[0004] Problems with existing technologies: 1. Most relevant technical reports utilize online testing, which results in complex equipment, limited flexibility, and limited adaptability to various operating environments. 2. Online monitoring generally utilizes instruments such as gas flowmeters, which lack the accuracy to detect hydrogen in oxygen and pose certain safety risks. 3. Because PEM electrolyzers often operate under fluctuating operating conditions, which can result in transient excessive gas production, direct connection to high-precision instruments carries a risk of impact damage. Utility Model Content

[0005] In order to overcome the deficiencies of the prior art, the utility model provides a device for collecting gas from PEM electrolysis of water and detecting hydrogen in oxygen offline, which solves the problems of complex equipment and poor flexibility in the prior art.

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] A gas collection device for PEM water electrolysis comprises a water pump, a first pipeline, a first gas collecting bottle, a second pipeline, a second gas collecting bottle, a third pipeline, and a container which are connected in sequence.

[0008] As a preferred technical solution, the outlet of the first pipeline is lower than the inlet of the second pipeline in the height direction, and the outlet of the second pipeline is lower than the inlet of the third pipeline in the height direction.

[0009] As a preferred technical solution, a first valve is provided on the first pipeline.

[0010] As a preferred technical solution, a second valve is provided on the third pipeline.

[0011] As a preferred technical solution, the inner diameter of the first pipeline is 20-100 mm.

[0012] As a preferred technical solution, the inner diameter of the second pipeline is 20-100 mm.

[0013] As a preferred technical solution, the container is a water tank or an electrolytic cell.

[0014] An off-line detection device for hydrogen in oxygen during PEM water electrolysis comprises the aforementioned gas collection device for PEM water electrolysis, a fourth pipeline, and a gas chromatograph.

[0015] As a preferred technical solution, the container is a dryer.

[0016] As a preferred technical solution, the inner diameter of the fourth pipeline is 20-100 mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The overall device of the utility model is simple and flexible, and is suitable for application in various scenarios;

[0019] (2) The utility model solves the problem that the air in the gas collection container is difficult to be fully discharged or the discharge time is long;

[0020] (3) The utility model can be directly connected to high-precision detection equipment and ensure the safety of the detection equipment and the accuracy of the detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the water filling and air exhaust process;

[0022] Figure 2 Schematic diagram of the gas collection and drainage process;

[0023] Figure 3 Schematic diagram of the water filling and exhaust detection process.

[0024] Marks and their corresponding names in the accompanying drawings: 1. water pump, 2. first pipeline, 3. first gas collecting bottle, 4. second pipeline, 5. second gas collecting bottle, 6. third pipeline, 7. container, 8. first valve, 9. second valve, 12. fourth pipeline, 13. gas chromatograph. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0026] Example 1

[0027] like Figures 1 to 3 As shown, the present invention uses a water-through-air method to solve the problem of insufficient exhaustion of air from the collection container and ensure the accuracy of the test results. Secondly, the gas is collected in a container using a ventilation and drainage method. Due to the flexibility of the collection device, it can be moved to a gas chromatograph with higher accuracy than traditional instruments for offline testing. This ensures the authenticity of the test results while avoiding the risk of excessive gas flow during online testing, which could damage the gas chromatograph. Furthermore, the measurement process is safe and risk-free, making it suitable for applications in a variety of scenarios.

[0028] A device for collecting gas from PEM electrolytic water and offline detection of hydrogen in oxygen adopts a method of filling with water and exhausting air. A water pump 1 is used to fill water with a flow rate of 0.1-10L / min along a first pipeline 2 with a diameter (inner diameter) of 20-100mm into a first gas collecting bottle 3 with a volume of 0.5-100L. When the first gas collecting bottle 3 is full of water, all the air in the bottle will reach the second gas collecting bottle 5 with a volume of 0.5-100L along a second pipeline 4 with a diameter (inner diameter) of 20-100mm. Similarly, the water in the first gas collecting bottle 3 will continue to reach the second gas collecting bottle 5 along the second pipeline 4, eventually filling the bottle with water, and the air will reach the external water tank (container 7) with a capacity of 5-200L along the third pipeline 6. This completes the removal of air from the first gas collecting bottle 3, the second gas collecting bottle 5 and each pipeline. Close the first valve 8 and the second valve 9, and move the above-mentioned part of the device to the electrolytic cell (container 7).

[0029] Next, collect the gas drainage, open the second valve 9 and the first valve 8, and the oxygen production rate from the anode is 0.001-5Nm 3 / h or the cathode hydrogen production rate is 0.002-10Nm 3 A gas-producing anode or cathode is connected to the electrolytic cell with a flow rate of 100 liters / h, and the gas is fed along the third pipeline 6 to the second gas collection bottle 5. As gas production gradually increases, the water in the second gas collection bottle 5 is transferred along the second pipeline 4 to the first gas collection bottle 3. Correspondingly, the water in the first gas collection bottle 3 is also discharged into the water tank along the first pipeline 2 by the gas. When the water in the second gas collection bottle 5, the first gas collection bottle 3, and each pipeline is emptied, gas collection is complete. Close the second valve 9 and the first valve 8, and move the above-mentioned part of the equipment to the gas chromatograph 13.

[0030] For water filling and exhaust testing, open the first valve 8 and the second valve 9, start the water pump 1, and control the flow rate to 0.05-10L / min to fill water into the first gas collecting bottle 3 along the first pipeline 2. When the first gas collecting bottle 3 is full of water, all the sample gas in the bottle will reach the second gas collecting bottle 5 along the second pipeline 4. Similarly, the water in the first gas collecting bottle 3 will continue to flow along the second pipeline 4 to the second gas collecting bottle 5, eventually filling the bottle with water. The sample gas will reach the external dryer (container 7) along the third pipeline 6. After being fully dried, it will reach the gas chromatograph 13 along the fourth pipeline 12 with a diameter (inner diameter) of 20-100mm for gas composition analysis.

[0031] The dryer contains 50-1000g of desiccant, which includes one or more of quartz sand, silica gel, aluminum oxide, calcium oxide, anhydrous sodium sulfate, and anhydrous magnesium sulfate.

[0032] It should be noted that since there will be some air in the dryer and the fourth pipeline 12, they should be evacuated with sample gas for 1-10 minutes before testing and analysis to ensure accuracy.

[0033] Example 2

[0034] like Figures 1 to 3 As shown, using Figure 1 The device shown is used for water filling and air exhaust. Open the first valve 8 and the second valve 9, control the water flow of the water pump 1 at 1L / min, and fill the 20L first gas collecting bottle 3 with water along the first pipe 2 with a diameter of 20mm until the bottle is full. The water will continue to flow along the second pipe 4 with a diameter of 20mm to the 20L second gas collecting bottle 5. When the bottle is full, the water will continue to flow along the third pipe 6 with a diameter of 20mm to the water tank with a capacity of 100L. When water flows in the water tank, the first valve 8 and the second valve 9 can be closed, and the air exhaust treatment of the entire device is completed. Move the above part of the device to the oxygen production rate of 0.01Nm 3 / h at the electrolytic cell.

[0035] use Figure 2The device shown collects and drains the anode gas of the electrolytic cell. Connect the anode gas outlet of the electrolytic cell 10 to the device, open the first valve 8 and the second valve 9, power on the electrolytic cell, and control the oxygen production rate at 0.01Nm 3 / h. Anode gas is fed into the second gas collection bottle 5 via the third pipeline 6. Water in the bottle is discharged into the first gas collection bottle 3 via the second pipeline 4 until all the water is discharged into the water tank along the first pipeline 2. Once no more water flows out, the first valve 8 and the second valve 9 are closed, completing anode gas collection. The above-mentioned equipment is moved to the gas chromatograph.

[0036] use Figure 3 The device shown is used to detect the composition of the anode gas. The third pipeline 6 in the device is connected to the dryer, and then connected to the gas chromatograph 13 through the fourth pipeline 12. After opening the first valve 8 and the second valve 9, start the water pump 1 to supply water at a water flow rate of 0.5L / min, and fill it into the first gas collecting bottle 3 along the first pipeline 2, while the moist anode gas will flow along the second pipeline 4 to the second gas collecting bottle 5, and then the moist anode gas in the second gas collecting bottle 5 will be discharged along the third pipeline 6 to the dryer containing 200g quartz sand and 100g silica gel for sufficient drying. The dried gas enters the gas chromatograph 13 along the fourth pipeline 12 with a diameter (inner diameter) of 20mm for detection. In order to ensure that the data is true and stable, the gas in the first 5 minutes is not detected to eliminate the influence of the small amount of air contained in the dryer and the fourth pipeline 12. The data is then recorded every 1 minute, for a total of 5 results, as shown in Table 1. It should be noted that as the detection time increases, water will fill the first gas collecting bottle 3 and then fill the second gas collecting bottle 5 along the second pipeline 4. Therefore, the entire test time must be ended before the second gas collecting bottle 5 is filled with water to avoid water directly entering the gas chromatograph 13 and causing damage to the equipment.

[0037] Comparative Example 1

[0038] Connect the anode gas outlet of the electrolytic cell to the gas flow meter, power on the electrolytic cell, and control the oxygen production rate to 0.01Nm 3 After the produced gas is evacuated for 2 hours, read the flow meter reading and record the test result of hydrogen in oxygen every 1 minute.

[0039] Example 3

[0040] like Figures 1 to 3 As shown, this embodiment provides a more detailed implementation method based on Example 1 and Example 2.

[0041] Example 3 is an improvement based on Example 2. The difference between Example 3 and Example 2 is that the oxygen production rate is set to 0.01 Nm 3 / h electrolytic cell was replaced with an oxygen production rate of 1Nm 3 / h electrolytic cell.

[0042] Comparative Example 2

[0043] Comparative Example 2 is an improvement based on Comparative Example 1. The difference between Comparative Example 2 and Comparative Example 1 is that the oxygen production rate is 0.01Nm 3 / h electrolytic cell was replaced with one with an oxygen production rate of 1Nm 3 / h electrolytic cell.

[0044] The composition of the anode gas was tested based on the national standards GB / T 8981-2008 and GB / T 28124-2011, with the results shown in Table 1. A comparison between Example 2 and Example 3 shows that accurate hydrogen-in-oxygen detection can be achieved regardless of whether the oxygen production rate is low or high. A comparison between Example 2 and Comparative Example 1, and between Example 3 and Comparative Example 2, shows that the hydrogen-in-oxygen detection results obtained using the device of the present invention have smaller deviations and higher accuracy, while the results obtained using the conventional gas flowmeter used in Comparative Examples 1 and 2 have larger deviations.

[0045] Table 1 Test results and deviations of hydrogen in oxygen

[0046] Sample No. Hydrogen in Oxygen 1# Hydrogen in Oxygen 2# Hydrogen in Oxygen 3# Oxygen in Hydrogen 4# Oxygen in Hydrogen 5# Relative standard deviation Example 2 0.245％ 0.234％ 0.226％ 0.241％ 0.238％ 3.07％ Comparative Example 1 0.272％ 0.216％ 0.228％ 0.278％ 0.249％ 10.83％ Example 3 0.466％ 0.481％ 0.492％ 0.478％ 0.485％ 2.00％ Comparative Example 2 0.442％ 0.497％ 0.513％ 0.431％ 0.492％ 7.62％

[0047] Compared with other online test systems, the utility model has higher flexibility and can be easily moved to the required scene for use.

[0048] The protection device is designed based on a drainage method that can solve the problem in traditional gas collection devices of using gas to exhaust air, which makes it difficult to completely exhaust the air or takes too long to completely exhaust the air.

[0049] In order to ensure the accuracy of the hydrogen in oxygen detection results, the device provided by the utility model can be directly connected to a high-precision detection instrument, which can not only obtain accurate data results but also ensure the service life of the detection instrument.

[0050] As described above, the present invention can be implemented well.

[0051] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Based on the technical essence of the present invention and within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement of the above embodiment shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A gas collection device for PEM water electrolysis, characterized in that: It comprises a water pump (1), a first pipeline (2), a first gas collecting bottle (3), a second pipeline (4), a second gas collecting bottle (5), a third pipeline (6), and a container (7) which are connected in sequence.

2. A gas collection device for PEM water electrolysis according to claim 1, characterized in that: The outlet of the first pipeline (2) is lower than the inlet of the second pipeline (4) in the height direction, and the outlet of the second pipeline (4) is lower than the inlet of the third pipeline (6) in the height direction.

3. A gas collection device for PEM water electrolysis according to claim 1, characterized in that: A first valve (8) is provided on the first pipeline (2).

4. A gas collection device for PEM water electrolysis according to claim 1, characterized in that: A second valve (9) is provided on the third pipeline (6).

5. A gas collection device for PEM water electrolysis according to claim 1, characterized in that: The inner diameter of the first pipeline (2) is 20-100 mm.

6. A gas collection device for PEM water electrolysis according to claim 1, characterized in that: The inner diameter of the second pipeline (4) is 20-100 mm.

7. A gas collection device for PEM water electrolysis according to any one of claims 1 to 6, characterized in that: The container (7) is a water tank or an electrolytic tank.

8. An off-line detection device for hydrogen in PEM electrolysis of water oxygen, characterized in that: The device comprises a gas collection device for PEM water electrolysis according to any one of claims 1 to 7, and further comprises a fourth pipeline (12) and a gas chromatograph (13).

9. The device for offline detection of hydrogen in PEM water electrolysis according to claim 8, characterized in that: The container (7) is a dryer.

10. An off-line detection device for hydrogen in PEM water electrolysis according to claim 8 or 9, characterized in that: The inner diameter of the fourth pipeline (12) is 20-100 mm.

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