PEM electrolyzed water purification system

Abstract

The utility model discloses a PEM electrolyzed water purification system. Comprising an electrolytic bath, a gas-water separator, a deoxidation tower, a drying tank, a first purging solenoid valve and a second purging solenoid valve, the electrolytic bath, the gas-water separator and the deoxidation tower are sequentially connected through pipelines, an outlet of the deoxidation tower is simultaneously connected with inlets of the first flow control electromagnetic valve and the second flow control electromagnetic valve through pipelines, an outlet of the first flow control electromagnetic valve is connected with an inlet of the purification inlet valve, and an outlet of the second flow control electromagnetic valve is connected with an inlet of the cooling inlet valve; the cooling inlet valve and the purification inlet valve are connected with the top of the drying tank through pipelines; the top of the drying tank is further connected with a regeneration outlet valve, and the regeneration outlet valve is connected to a centralized discharge outlet through a pipeline. According to the utility model, the principle of the whole purification system is optimized, and a simpler hydrogen production device is provided.

Description

Technical Field

[0001] The utility model belongs to the field of fuel cells, and particularly relates to a PEM electrolyzed water purification system and a control method thereof. Background Art

[0002] The hydrogen purification system is used to connect the electrolyzed water hydrogen production equipment to deoxygenate and purify the hydrogen produced by the electrolyzed water hydrogen production equipment. In the prior art, the hydrogen purification system includes a first hydrogen drying tower, a second hydrogen drying tower, and a third hydrogen drying tower. The first hydrogen drying tower, the second hydrogen drying tower, and the third hydrogen drying tower can alternately perform drying and purification work. When hydrogen enters at a constant and uninterrupted flow rate, the molecular sieve in the drying tower does not require additional introduction of other media. When the system enters the shutdown state, the nitrogen gas replaced by the hydrogen pipeline can be used to cool down and regenerate the molecular sieve in the drying tower alone, avoiding the system safety risk caused by hydrogen storage and reducing the complexity of the entire purification system at the same time. After the electrolytic cell generates hydrogen, it will first enter the first gas-water separator for rough separation to separate the liquid water and part of the gaseous water in the hydrogen, and then enter the condenser for cooling to make the gaseous water precipitate into liquid water, and then enter the second gas-water separator for secondary separation to separate the precipitated liquid water, and then enter the heater to heat the gas to reach the overall deoxygenation tower for deoxygenation reaction to make the oxygen in the hydrogen become liquid water through chemical reaction. The gas after passing through the deoxygenation tower enters the third gas-water separator to separate the liquid water generated by the reaction, further improving the hydrogen purity. Immediately afterwards, it enters the filter, cooler, and separator to preprocess the hydrogen to be purified. The preprocessed gas is divided into two parts. A small part of the gas cools down the first drying tower, then undergoes adsorption regeneration in the second drying tower, and finally returns to the third drying tower for drying and purification. Most of the gas enters the third drying tower for drying and purification. The cooling / regeneration / drying and purification states of the above three drying towers are alternated, and the gas after drying and purification is pressurized by a compressor and then output.

[0003] The overall principle of the above system is relatively complex and there are many devices; the power consumption of the hydrogen production equipment using the compression pump scheme is high, the overall equipment volume is larger, and it is not suitable for small hydrogen production equipment; moreover, there is a safety risk in the hydrogen storage tank, and the system replacement time is longer after shutdown; if the hydrogen before purification does not meet the purification requirements, it cannot be directly discharged and still needs to enter the drying and regeneration tank before discharging. Summary of the Utility Model

[0004] The utility model overcomes the existing defects and provides a PEM electrolyzed water purification system. The utility model optimizes the principle of the entire purification system and provides a simpler hydrogen production equipment.

[0005] The technical solution of the utility model is as follows.

[0006] A PEM electrolytic water purification system, comprising an electrolytic cell, a gas-water separator, a deoxidation tower, a drying tank, a first purge solenoid valve and a second purge solenoid valve; the electrolytic cell, the gas-water separator and the deoxidation tower are sequentially connected by pipelines, the outlet of the deoxidation tower is connected to the inlets of a first flow control solenoid valve and a second flow control solenoid valve through pipelines, the outlet of the first flow control solenoid valve is connected to the inlet of a purification inlet valve, the outlet of the second flow control solenoid valve is connected to the inlet of a cooling inlet valve, and the cooling inlet valve and the purification inlet valve are connected to the top of the drying tank through pipelines; a regeneration outlet valve is further connected to the top of the drying tank, and the regeneration outlet valve is connected to a centralized discharge outlet through a pipeline; the bottom outlet of the drying tank is respectively connected with a cooling outlet valve, a purification outlet valve and a regeneration inlet valve, and the outlet pipelines of the cooling outlet valve, the purification outlet valve and the regeneration inlet valve are aggregated and then connected to a hydrogen production outlet;

[0007] A pipeline is also connected to the pipeline between the electrolytic cell and the gas-water separator and is connected to a replacement nitrogen inlet; a pipeline is also connected to the pipeline between the deoxidation tower and the cooling inlet valve and is connected to the replacement nitrogen inlet.

[0008] Further preferably, the deoxidation tower is also connected with a detection gas solenoid valve through a pipeline, and then is divided into two paths, which are respectively connected with an oxygen-in-hydrogen sensor and a discharge solenoid valve; the oxygen-in-hydrogen sensor and the discharge solenoid valve are respectively connected to the centralized discharge outlet through pipelines.

[0009] Further preferably, a back pressure valve, a flowmeter, a switch valve and a flame arrester are sequentially connected to the pipeline of the hydrogen production outlet.

[0010] Further preferably, a pipeline is also connected to the pipeline between the oxygen-in-hydrogen sensor and the detection gas solenoid valve and is respectively connected to the centralized discharge outlet and the hydrogen production outlet through an anti-backflow check valve.

[0011] Further preferably, a dew point meter and an anti-backflow check valve are sequentially arranged on the pipeline between the anti-backflow check valve and the centralized discharge outlet.

[0012] Further preferably, the drying tank includes a first drying tank, a second drying tank and a third drying tank.

[0013] Further preferably, a purification gas flow control valve is further included; the purification gas flow control valve is arranged on the pipeline between the deoxidation tower and the purification inlet valve.

[0014] Further preferably, the present utility model further includes a regeneration gas flow control valve; the regeneration gas flow control valve is arranged on the pipeline between the deoxidation tower and the cooling inlet valve.

[0015] Further preferably, the top outlets of the first drying tank, the second drying tank, and the third drying tank are respectively connected with a cooling inlet valve, a purification inlet valve, and a regeneration outlet valve.

[0016] Further preferably, the bottom outlets of the first drying tank, the second drying tank, and the third drying tank are respectively connected with a cooling outlet valve, a purification outlet valve, and a regeneration inlet valve. All the cooling outlet valves, purification outlet valves, and regeneration inlet valves are aggregated and then connected to the hydrogen production outlet.

[0017] Compared with the prior art, the advantages of the present utility model are as follows:

[0018] 1. The system structure of the present utility model is simple. Meanwhile, the number of components of the whole system is reduced, the integration degree is higher, and the cost is lower.

[0019] 2. The present utility model replaces the compressor method by adopting the back pressure valve pressure control method, which reduces the overall volume and power consumption. Meanwhile, the safety risk of hydrogen storage is also eliminated;

[0020] 3. The present utility model can reduce the usage amount of external replacement nitrogen by using the raw material gas to cool and regenerate the drying tower;

[0021] 4. The present utility model adds an external replacement nitrogen branch in the drying tank, which can well avoid the interruption of the cooling and regeneration process of the drying tank due to the lack of raw material gas, thus affecting the next startup time;

[0022] 5. The present utility model adds the detection of oxygen in hydrogen at the front end of the drying tank. When the raw material gas does not meet the purification requirements, it can be directly discharged without entering the drying tank, greatly improving the efficiency of the drying tank. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the cathode circuit of a PEM electrolyzed water system of the present utility model;

[0024] Figure 2 It is the system working route diagram when the oxygen in hydrogen of the deoxygenated gas does not meet the inlet requirements of the purification system;

[0025] Figure 3 It is the system working route diagram when the oxygen in hydrogen of the deoxygenated gas meets the inlet requirements of the purification system;

[0026] Figure 4 It is the system working route diagram when the system is shut down or the regeneration and cooling stages are not completed yet. Each component in the figure is as follows:

[0027] Electrolyzer 1, gas-water separator 2, deoxidation tower 3, purified gas flow control valve (first flow control solenoid valve) 4, regeneration gas flow control valve (second flow control solenoid valve) 5, cooling inlet valve 6, cooling outlet valve 7, purification inlet valve 8, purification outlet valve 9, regeneration outlet valve 10, regeneration inlet valve 11, anti-backflow check valve 12, oxygen-in-hydrogen sensor 13, dew point meter 14, back pressure valve 15, flow meter 16, switching valve 17, flame arrester 18, detection gas solenoid valve 19, discharge solenoid valve 20, first purge solenoid valve 21, second purge solenoid valve 22, first drying tank 23, second drying tank 24, third drying tank 25. Detailed implementation manners

[0028] The following further describes the present utility model in detail with reference to specific embodiments. However, the implementation manners of the present utility model are not limited thereto. For process parameters not specifically noted, conventional techniques can be referred to.

[0029] Embodiment 1

[0030] As Figure 1As shown in the figure, a PEM electrolyzed water purification system includes an electrolytic cell 1, a gas-water separator 2, a deoxidation tower 3, a drying tank, a first purge solenoid valve 21, and a second purge solenoid valve 22. The electrolytic cell 1, the gas-water separator 2, and the deoxidation tower 3 are sequentially connected by pipelines. The outlet of the deoxidation tower 3 is connected to the inlets of a first flow control solenoid valve 4 and a second flow control solenoid valve 5 through pipelines. The outlet of the first flow control solenoid valve 4 is connected to the inlet of a purification inlet valve 8, and the outlet of the second flow control solenoid valve 5 is connected to the inlet of a cooling inlet valve 6. The cooling inlet valve 6 and the purification inlet valve 8 are connected to the top of the drying tank through pipelines. A regeneration outlet valve 10 is also connected to the top of the drying tank, and the regeneration outlet valve 10 is connected to a centralized discharge outlet through a pipeline. The bottom outlet of the drying tank is respectively connected to a cooling outlet valve 7, a purification outlet valve 9, and a regeneration inlet valve 11. The outlet pipelines of the cooling outlet valve 7, the purification outlet valve 9, and the regeneration inlet valve 11 are aggregated and then connected to a hydrogen production outlet. A pipeline is also connected to the pipeline between the electrolytic cell 1 and the gas-water separator 2 and is connected to a replacement nitrogen inlet. A pipeline is also connected to the pipeline between the deoxidation tower 3 and the cooling inlet valve 6 and is connected to a replacement nitrogen inlet. The deoxidation tower 3 is also connected to a detection gas solenoid valve 19 through a pipeline, and then is divided into two paths, which are respectively connected to an oxygen-in-hydrogen sensor 13 and a discharge solenoid valve 20. The oxygen-in-hydrogen sensor 13 and the discharge solenoid valve 20 are respectively connected to a centralized discharge outlet through pipelines. A back pressure valve 15, a flow meter 16, a switch valve 17, and a flame arrester 18 are sequentially connected to the pipeline of the hydrogen production outlet. A pipeline is also connected to the pipeline between the oxygen-in-hydrogen sensor 13 and the detection gas solenoid valve 19 and is connected to a centralized discharge outlet and a hydrogen production outlet respectively through a non-return valve 12 to prevent backflow. A dew point meter 14 and a non-return valve 12 to prevent backflow are sequentially arranged on the pipeline between the non-return valve 12 to prevent backflow and the centralized discharge outlet. This embodiment also includes a purification gas flow control valve 4 and a regeneration gas flow control valve 5. The purification gas flow control valve 4 is arranged on the pipeline between the deoxidation tower 3 and the purification inlet valve 8, and the regeneration gas flow control valve 5 is arranged on the pipeline between the deoxidation tower 3 and the cooling inlet valve 6. The top outlets of a first drying tank 23, a second drying tank 24, and a third drying tank 25 are respectively connected to a cooling inlet valve 6, a purification inlet valve 8, and a regeneration outlet valve 10. The bottom outlets of the first drying tank 23, the second drying tank 24, and the third drying tank 25 are respectively connected to a cooling outlet valve 7, a purification outlet valve 9, and a regeneration inlet valve 11. All the cooling outlet valves 7, purification outlet valves 9, and regeneration inlet valves 11 are aggregated and then connected to a hydrogen production outlet.

[0031] In this embodiment, the drying tank includes a first drying tank 23, a second drying tank 24, and a third drying tank 25. As described in the above drying tank, a cooling inlet valve 6, a purification inlet valve 8, and a regeneration outlet valve 10 are respectively connected to the tops of the first drying tank 23, the second drying tank 24, and the third drying tank 25; a cooling outlet valve 7, a purification outlet valve 9, and a regeneration inlet valve 11 are connected to the bottoms.

[0032] The working principles of the cathode circuit of the PEM electrolyzed water of the present utility model are respectively:

[0033] Among them, when the oxygen in the deoxygenated gas hydrogen does not meet the requirements of the purification system inlet, the working route of the system is from the electrolytic cell 1 through the gas-water separator 2 to the deoxygenation tower 3. Since it is necessary to first monitor whether the gas before entering the purification equipment meets the requirements, the detection gas solenoid valve 19 is in the open state at this time, and the purification gas flow control valve (the first flow control solenoid valve) 4 and the regeneration gas flow control valve (the second flow control solenoid valve) 5 are in the closed state. When the oxygen concentration in the hydrogen is greater than 2%, the discharge solenoid valve 20 opens and is directly emptied without entering the purification system for purification; when the oxygen concentration in the hydrogen is in the range of 0.2-2%, the purification gas flow control valve (the first flow control solenoid valve) 4 and the regeneration gas flow control valve (the second flow control solenoid valve) 5 are opened, and the detection gas solenoid valve 19 is closed, and the purification work officially starts. (Details can be seen in Figure 2 ).

[0034] When the oxygen in the hydrogen of the gas after deoxidation meets the inlet of the purification system, the system works normally. The route is (only one situation is exemplified here, and the other two situations are: Situation 1: The purification inlet valve 8 and the purification outlet valve 9 of the third drying tower 25 are opened, and the cooling inlet valve 6 and the cooling outlet valve 7 of the first drying tower 23 are opened; the regeneration inlet valve 11 and the regeneration outlet valve 10 of the second drying tower 24 are opened. The third drying tower 25 is in the purification operation state, the first drying tower 23 is in the cooling operation state, and the second drying tower 24 is in the regeneration operation state. The purified gas only flows through the third drying tower 25, and the regeneration gas first flows through the first drying tower 23 and then flows to the second drying tower 24. Situation 2: The purification inlet 8 and the purification outlet valve 9 of the second drying tower 24 are opened, and the cooling inlet valve 6 and the cooling outlet valve 7 of the third drying tower 25 are opened; the regeneration inlet valve 11 and the regeneration outlet valve 10 of the first drying tower 23 are opened. The second drying tower 24 is in the purification operation state, the third drying tower 25 is in the cooling operation state, and the first drying tower 23 is in the regeneration operation state. The purified gas only flows through the second drying tower 24, and the regeneration gas first flows through the third drying tower 25 and then flows to the first drying tower 23. The operation state sequence of the drying tower is cooling → regeneration → purification): The system working route is from the electrolytic cell 1 through the gas-water separator 2 to the deoxidation tower 3. Then the purified gas flow control valve (the first flow control solenoid valve) 4 and the regeneration gas flow control valve (the second flow control solenoid valve) 5 are in the open state. Generally, the ratio of the purified gas flow to the regeneration gas flow is in the range of 7:3 to 9:1. This range is determined according to the regeneration time of the drying tower. Then the first drying tower 23 is in the purification state, the second drying tower 24 is in the cooling state, and the third drying tower 25 is in the regeneration state. According to the working states of each drying tower, it can be known that the purification inlet valve 8 and the purification outlet valve 9 of the first drying tower 23 are in the open state, and the other four valves are in the closed state. After the raw material gas passes through the first drying tower 23 and completes the purification process, it will flow through the purification outlet valve 14 and the oxygen-in-hydrogen sensor 13 to continuously detect whether it meets the requirements. If the detected gas pressure is too small and it is not suitable to return to the main path, it will be directly discharged; at the same time, it will also flow through the back pressure valve 15 to build up pressure to the required pressure, and then output after passing through the flow meter 16, the switching valve 17 and the flame arrester 18;

[0035] The regeneration inlet valve 11 and the regeneration outlet valve 10 of the second drying tower 24 are in the open state, and the other four valves are in the closed state. The cooling inlet valve 6 and the cooling outlet valve 7 of the third drying tower are in the open state, and the other four valves are in the closed state. A small stream of raw material gas flowing through the regeneration gas flow control valve (the second flow control solenoid valve) 5 will first enter the second drying tower through the cooling inlet valve 6 of the second drying tower for cooling. Then, after this heat exchange process, the temperature of this stream of raw material gas will increase to a certain extent, and then it will flow out of the second drying tower 24 through the cooling outlet valve 7 and flow through the pipeline to enter the third drying tower 25 through the regeneration inlet valve 11 of the third drying tower 25. After the small stream of raw material gas assists in the regeneration in the third drying tower 25, it flows out of the third drying tower 25 through the regeneration outlet valve 10 and is finally discharged centrally. (For details, see Figure 3 )

[0036] When the system is shut down or the regeneration and cooling stages are not yet completed, the working route of the system is that the replacement nitrogen introduced from the outside flows into the first purge solenoid valve 21 and the second purge solenoid valve 22 respectively to enter the system for purging. The nitrogen flowing into the first purge solenoid valve 21 will first pass through the gas-water separator 2 to the deoxidation tower 3, and then flow through the purified gas flow control valve (the first flow control solenoid valve) 4 to the first drying tower 23 that is undergoing purification [only one of the situations is exemplified here, and the other two situations are the same], to cool and regenerate the first drying tower 23. A part of the nitrogen flowing out of the first drying tower will be discharged after passing through the back pressure valve 15, the flow meter 16, the on-off valve 17 and the flame arrester 18, and another part will be discharged after passing through the purified gas outlet valve 14 and the oxygen-in-hydrogen sensor 13. The nitrogen flowing to the second purge solenoid valve 22 will first enter the second drying tower through the cooling inlet valve 6 of the second drying tower to complete the cooling and regeneration stage, and then flow to the third drying tower to complete the regeneration process and then be discharged. (For details, see Figure 4 ).

Claims

1. A PEM electrolysis water purification system, characterized in that: The invention comprises an electrolytic cell (1), a gas-water separator (2), a deoxidation tower (3), a drying tank, a first purge battery valve (21) and a second purge battery valve (22); the electrolytic cell (1), the gas-water separator (2) and the deoxidation tower (3) are connected in sequence through pipelines, the outlet of the deoxidation tower (3) is connected to the inlet of a first flow control solenoid valve (4) and the inlet of a second flow control solenoid valve (5) through pipelines, the outlet of the first flow control solenoid valve (4) is connected to the inlet of a purification inlet valve (8), and the outlet of the second flow control solenoid valve (5) is connected to the inlet of a purification inlet valve (8). The inlet of the cooling inlet valve (6) is connected, and the cooling inlet valve (6) and the purification inlet valve (8) are connected to the top of the drying tank through a pipeline; the top of the drying tank is also connected to a regeneration outlet valve (10), and the regeneration outlet valve (10) is connected to a centralized discharge outlet through a pipeline; the bottom outlet of the drying tank is respectively connected to a cooling outlet valve (7), a purification outlet valve (9) and a regeneration inlet valve (11), and the outlet pipelines of the cooling outlet valve (7), the purification outlet valve (9) and the regeneration inlet valve (11) are connected to the hydrogen production outlet after being collected; The pipeline between the electrolytic cell (1) and the gas-water separator (2) is also connected to a pipeline connected to a replacement nitrogen inlet; the pipeline between the deoxidation tower (3) and the cooling inlet valve (6) is also connected to a pipeline connected to a replacement nitrogen inlet.

2. A PEM electrolysis water purification system according to claim 1, characterized in that: The deoxygenation tower (3) is also connected to a gas detection battery valve (19) via a pipeline, and then divided into two paths, which are respectively connected to the hydrogen oxygen sensor (13) and the discharge battery valve (20); the hydrogen oxygen sensor (13) and the discharge battery valve (20) are respectively connected to the centralized discharge outlet via pipelines.

3. A PEM electrolysis water purification system according to claim 1, characterized in that: The pipeline of the hydrogen production outlet is also connected in sequence with a back pressure valve (15), a flow meter (16), a switch valve (17) and a flame arrester (18).

4. A PEM electrolysis water purification system according to claim 2, characterized in that: The pipeline between the hydrogen oxygen sensor (13) and the detection gas battery valve (19) is also connected to a pipeline which is connected to the centralized discharge outlet and the hydrogen production outlet respectively through an anti-backflow one-way valve (12).

5. A PEM electrolysis water purification system according to claim 4, characterized in that: A dew point meter (14) and the anti-backflow one-way valve (12) are also arranged in sequence on the pipeline between the anti-backflow one-way valve (12) and the centralized discharge outlet.

6. A PEM electrolysis water purification system according to claim 1, characterized in that: The drying tank comprises a first drying tank (23), a second drying tank (24) and a third drying tank (25).

7. A PEM electrolysis water purification system according to claim 1, characterized in that: It also comprises a first flow control solenoid valve (4); the first flow control solenoid valve (4) is arranged on the pipeline between the deoxidation tower (3) and the purification inlet valve (8).

8. A PEM electrolysis water purification system according to claim 1, characterized in that: It also includes a second flow control solenoid valve (5); the second flow control solenoid valve (5) is arranged on the pipeline between the deoxidation tower (3) and the cooling inlet valve (6).

9. A PEM electrolysis water purification system according to claim 6, characterized in that: The top outlets of the first drying tank (23), the second drying tank (24) and the third drying tank (25) are respectively connected to a cooling inlet valve (6), a purification inlet valve (8) and a regeneration outlet valve (10).

10. A PEM electrolysis water purification system according to claim 6, characterized in that: The bottom outlets of the first drying tank (23), the second drying tank (24) and the third drying tank (25) are respectively connected to a cooling outlet valve (7), a purification outlet valve (9) and a regeneration inlet valve (11), and all the cooling outlet valves (7), the purification outlet valves (9) and the regeneration inlet valves (11) are collected and connected to the hydrogen production outlet.

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