PEM high-voltage electrolytic cell hydrogen side drainage pressure regulating device and system

Abstract

The utility model discloses a PEM high-voltage electrolytic bath hydrogen side drainage pressure regulating device and system, which comprises an electrolytic bath and a cathode separator connected with a cathode outlet of the electrolytic bath, the cathode separator is connected with a cathode drainage pipeline, the cathode drainage pipeline comprises two branch pipelines which are connected in parallel, each branch pipeline is provided with a needle valve and a pneumatic control valve, and the two branch pipelines are connected with the cathode separator. And a cathode differential pressure liquid level meter is arranged on the cathode separator. According to the utility model, the cathode drainage pipeline comprises the two branch pipelines which are connected in parallel, and each branch pipeline is provided with the needle valve and the pneumatic control valve, so that the device can adapt to the condition that the electrolytic bath simultaneously meets pressure fluctuation at high pressure and low pressure; when the opening degree of the two needle valves is large and the separator adapts to low-pressure drainage, the situation that the liquid level of the separation tank is high due to the fact that the discharged water is lower than water permeating from the hydrogen side of the electrolytic cell due to the fact that the water in the separator is discharged too slowly is avoided, and therefore the pressure fluctuation is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of electrolytic water hydrogen production, more particularly to a PEM high pressure electrolytic cell hydrogen side drainage pressure regulating device and system. BACKGROUND

[0002] PEM electrolytic cell (Proton Exchange Membrane Electrolyzer) as an important way of hydrogen production technology, has significant high pressure operation advantage, indicates its wide application in future energy production. First, PEM electrolytic cell can operate stably at higher operating pressure, which makes it avoid the compression link of low pressure hydrogen in the hydrogen production process, thereby reducing energy loss and system complexity. The hydrogen produced directly under high pressure can reduce the demand for compression equipment, reduce the capital and operating cost of the overall system. In addition, PEM electrolytic cell has higher current density and efficient electrolysis performance, which can further improve the electrolysis efficiency and enhance the overall performance of the system under high pressure operation condition. With the continuous progress of electrolytic cell technology, the operation stability and durability of PEM electrolytic cell under high pressure have been significantly improved, which can better adapt to the characteristics of renewable energy with greater volatility, especially in areas with greater fluctuations in wind and solar energy. Through high pressure hydrogen production, better energy storage and regulation can be achieved. More importantly, PEM electrolytic cell high pressure hydrogen production can effectively reduce the transportation and storage cost of hydrogen, improve the economy of hydrogen supply chain. Since high pressure hydrogen is directly available in many industrial applications, especially in high energy consumption industries such as chemical industry and steel industry, PEM electrolytic cell high pressure hydrogen production technology not only meets the needs of these industries, but also helps to achieve the goal of zero carbon emission. In summary, PEM electrolytic cell high pressure operation not only improves the efficiency and economy of hydrogen production, but also promotes the development of hydrogen energy industry towards high efficiency, low cost and sustainability, providing strong technical support for global low-carbon economy and energy transformation.

[0003] Currently, water electrolysis hydrogen production is developing towards higher temperature and higher pressure. With the increase of system pressure, higher requirements are put forward for the pressure control of the cathode side of the electrolytic cell. Therefore, the control of the cathode side pressure in the electrolytic cell test system must be more accurate. Since the PEM type water electrolysis test system is an anode side circulating water, the cathode side is mainly hydrogen and water permeated by the electrolytic cell membrane. Therefore, the hydrogen side separation tank will store a large amount of water during long-term operation of the electrolytic cell. These water needs to be discharged regularly, but the discharge process will inevitably cause large fluctuations in the cathode pressure, thereby affecting the performance of the electrolytic cell. UTILITY MODEL CONTENTS

[0004] The technical problem to be solved by the utility model is how to avoid pressure fluctuations during hydrogen side drainage of PEM electrolytic cell during long-term high pressure operation.

[0005] The utility model discloses a PEM high -pressure electrolytic cell hydrogen side drainage pressure regulating device, including electrolytic cell and with electrolytic cell cathode outlet links's cathode separator, is connected with cathode separator on the cathode separator and has cathode liquid discharge pipeline, and the cathode liquid discharge pipeline includes two parallel branch pipelines, and is equipped with needle valve and pneumatic control valve on each branch pipeline, is equipped with cathode pressure difference liquid level meter on the cathode separator.

[0006] The cathode liquid discharge pipeline includes two parallel branch pipelines, and a needle valve and a pneumatic control valve are arranged on each branch pipeline, which can adapt to the situation that the electrolytic cell meets pressure fluctuation under high pressure and low pressure. When the opening degree of one needle valve is small, the water in the separator will not be immediately emptied to cause large pressure fluctuation during high-pressure drainage. When the opening degree of two needle valves is large, the water in the separator will not be discharged too slowly to cause the discharged water to be lower than the water permeated from the hydrogen side of the electrolytic cell, thereby causing the liquid level of the separation tank to be high and reducing pressure fluctuation.

[0007] As a preferred technical solution, the cathode separator is connected with a cathode exhaust pipeline, and the cathode exhaust pipeline is provided with a cathode back pressure valve.

[0008] As a preferred technical solution, the cathode outlet of the electrolytic cell is connected with the cathode separator through a cathode output pipeline.

[0009] As a preferred technical solution, the cathode liquid discharge pipeline further includes a main pipeline and a wastewater pipeline, and the two branch pipelines are connected with the main pipeline at one end and connected with the wastewater pipeline at the other end.

[0010] As a preferred technical solution, the electrolytic cell is connected with a direct current power supply, the positive electrode of the direct current power supply is connected with the anode of the electrolytic cell, and the negative electrode of the direct current power supply is connected with the cathode of the electrolytic cell.

[0011] As a preferred technical solution, the cathode pressure difference liquid level meter is located at the side of the cathode separator.

[0012] As a preferred technical solution, the cathode separator is provided with a cathode pressure sensor.

[0013] As a preferred technical solution, the cathode separator is provided with a cathode pressure sensor.

[0014] As a preferred technical solution, the cathode separator is provided with a cathode pressure sensor.

[0015] The utility model discloses a PEM high -pressure electrolytic cell hydrogen side drainage pressure regulating system, including above-mentioned high -pressure electrolytic cell hydrogen side drainage pressure regulating device.

[0016] The utility model discloses the beneficial effect lies in:

[0017] (1) in the utility model, the cathode drainage pipeline includes two shunt branch lines, and the needle valve and pneumatic control valve are arranged on each branch line, can adapt to the situation that electrolytic cell is in high pressure and low pressure and satisfies pressure fluctuation simultaneously, the opening of one needle valve is smaller, adapts to high pressure drainage, and the water in the separator will not be emptied immediately to cause the condition of big pressure fluctuation, and the opening of two needle valves is bigger, adapts to low pressure drainage, and the water in the separator will not be discharged too slowly, causes the water of discharge to be lower than the water of electrolytic cell hydrogen side penetration, causes the liquid level of separation tank to be high, thereby reduces pressure fluctuation. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The device structure schematic view provided for the utility model embodiment;

[0019] Figure 2 The flow chart provided for the utility model embodiment;

[0020] Drawing reference: 1, electrolytic cell;2, anode separator;3, cathode separator;4, anode differential pressure liquid level meter;5, circulating water pump;6, heater;7, flow meter;8, anode pressure sensor;9, anode back pressure valve;10, cathode pressure sensor;11, cathode differential pressure liquid level meter;12, cathode back pressure valve;13, first drainage needle valve;14, first drainage pneumatic control valve;15, second drainage needle valve;16, second drainage pneumatic control valve;17, direct current power supply. DETAILED DESCRIPTION

[0021] To make the purpose, technical scheme and advantage of the utility model embodiment clearer, the technical scheme in the utility model embodiment will be clearly and completely described below in conjunction with the utility model embodiment, and obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor belong to the scope of the utility model protection.

[0022] Reference Figure 1The application discloses a hydrogen side drainage pressure regulating device for a PEM high-voltage electrolytic cell, which comprises an electrolytic cell 1, an electrolytic cell circulating water supply unit and a direct current power supply unit.

[0023] The electrolytic cell circulating water supply unit comprises an anode separator 2, a cathode separator 3, an anode differential pressure liquid level meter 4, a circulating water pump 5, a heater 6 and a flow meter 7.

[0024] The anode differential pressure liquid level meter 4 is arranged on the side of the anode separator 2 and is used for monitoring the anode liquid level of the electrolytic cell 1 and ensuring continuous electrolysis of the electrolytic cell 1 by circulating water supply.

[0025] The anode exhaust pipe is connected to a gas tail exhaust for providing anode back pressure in the electrolysis process of the electrolytic cell 1.

[0026] The cathode separator 3 is provided with a cathode pressure sensor 10, and the cathode exhaust pipeline is provided with a cathode back pressure valve 12; the cathode pressure sensor 10 is electrically connected with a controller, and the controller is electrically connected with the cathode back pressure valve 12; the cathode separator 3 is provided with a cathode differential pressure liquid level gauge 11 for monitoring the liquid level of the cathode separator 3; the cathode liquid discharge pipeline comprises a main pipeline, two branch pipelines and a waste water pipeline; the two branch pipelines are connected in parallel and are respectively a first branch pipeline and a second branch pipeline; one end of each of the two branch pipelines is connected with one end of the main pipeline through a three-way joint, and the other end of each of the two branch pipelines is connected with the waste water pipeline through a three-way joint; the first branch pipeline is provided with a first drain needle valve 13 and a first drain air control valve 14; and the second branch pipeline is provided with a second drain needle valve 15 and a second drain air control valve 16.

[0027] The direct current power supply unit comprises a direct current power supply 17 for supplying power to the electrolytic cell 1; the positive electrode of the direct current power supply 17 is connected with the anode of the electrolytic cell 1, and the negative electrode of the direct current power supply 17 is connected with the cathode of the electrolytic cell 1, so as to load the electrolytic cell 1 to produce gas.

[0028] It should be noted that the high pressure side of the cathode differential pressure liquid level gauge 11 and the high pressure side of the anode differential pressure liquid level gauge 4 are respectively connected with the lowest end of the side of the corresponding separator, and the low pressure side is connected with the highest end of the side of the cathode separator 3, so as to monitor the liquid level height of each separator; the embodiment further provides a PEM high pressure electrolytic cell hydrogen side drain pressure regulating system.

[0029] The pressure regulating method comprises the following steps:

[0030] The target value of the electrolytic cell 1 anode inlet temperature is determined, and the drain starting liquid level, the target liquid level, the pressure switching value, the pressure target value and the intermittent drain time of the first drain air control valve 14 of the cathode separator 3 are determined, wherein,

[0031] The drain starting liquid level: when the cathode differential pressure liquid level gauge 11 of the cathode separator 3 detects that the drain starting liquid level is reached, the liquid discharge is started through the cathode liquid discharge pipeline;

[0032] The target liquid level: when the cathode differential pressure liquid level gauge 11 of the cathode separator 3 detects that the target liquid level is reached, the liquid discharge is stopped;

[0033] The pressure switching value: the pressure value in the cathode separator 3 is detected by the cathode pressure sensor 10, and compared with the switching value to determine whether the current cathode separator 3 is in high pressure or low pressure;

[0034] The pressure target value: when the pressure target value is reached, the pressure regulating is stopped;

[0035] The electrolytic cell 1 is operated, and the electrolytic cell 1 is loaded by the direct current power supply 17; the anode back pressure valve 9 and the cathode back pressure valve 12 are operated according to the feedback values of the anode pressure sensor 8 and the cathode pressure sensor 10 respectively to reach the target value.

[0036] Referring to Figure 2 , the first drain needle valve 13 is given a smaller opening, and the second drain needle valve 15 is given a larger opening, that is, the opening of the first drain needle valve 13 is reduced, and the opening of the second drain needle valve 15 is increased, where the increase and decrease refer to the size of the corresponding flow rate. During the long-term operation of the electrolytic cell 1, when the liquid level monitored by the cathode differential pressure liquid level gauge 11 reaches the drain starting liquid level, it is determined according to the feedback value of the cathode pressure sensor 10 whether the current is in a low pressure or high pressure state, so as to adjust the opening of the first drain air control valve 14 or the second drain air control valve 16;

[0037] When the pressure is high, the first drain air control valve 14 is opened, and when the pressure is low, the second drain air control valve 16 is opened. When the pressure is high, the opening of the first drain needle valve 13 is small, which greatly reduces the rate of high-pressure drainage. At the same time, the first drain air control valve 14 is opened in a coupled pulse mode. It should be noted that the coupled pulse mode here refers to intermittent opening. The first drain air control valve 14 is intermittently started and stopped within a specified time, so that the liquid level of the cathode separator 3 slowly decreases to the target liquid level. Since the flow rate of the first drain air control valve 14 is greater than that of the first drain needle valve 13, direct drainage will result in a large liquid discharge flow rate, which in turn will cause rapid pressure loss in the cathode separator 3, which is not conducive to pressure stabilization.

[0038] The opening time of the first drain air control valve 14 is limited by the difference between the feedback value of the cathode pressure sensor 10 and the target value. It is determined whether the difference between the pressure displayed by the cathode pressure sensor 10, i.e. the actual pressure, and the set pressure target value is within the error range, i.e. a certain set value. If it is less than or equal to the certain value, it is detected whether the liquid level of the cathode separator 3 is less than or equal to the drain starting liquid level. If it is within the range, the first drain air control valve 14 is closed,

[0039] If the difference is greater than or equal to the certain value, the first drain air control valve 14 is closed. When the difference is less than or equal to the set target difference, the first drain air control valve 14 is opened in a pulse mode.

[0040] When it is monitored that the feedback value of the cathode pressure sensor 10 is in a low pressure state, the small opening of the first drain needle valve 13 may cause the hydrogen side permeation of the electrolytic cell to be greater than the water discharged from the cathode separator 3, thereby causing the hydrogen side liquid level to rise during the long-term operation of the electrolytic cell 1. Therefore, the second drain needle valve 15 is set to have a larger opening, and the drain path is discharged from the second drain needle valve 15 and the second drain air control valve 16, which can stabilize the hydrogen side pressure of the electrolytic cell 1 near the target value while discharging the cathode separator 3 to the target liquid level;

[0041] Specifically: open the second drainage air control valve 16, the opening time of the second drainage air control valve 16 is limited by the difference between the feedback value of the cathode pressure sensor 10 and the target value, whether the difference between the pressure displayed by the cathode pressure sensor 10, i.e. the actual pressure, and the set pressure target value is within the error range, i.e. a certain set value, is determined, and if it is less than or equal to the certain value, it is determined whether the liquid level of the cathode separator 3 is less than or equal to the drainage starting liquid level, and if it is, the second drainage air control valve 16 is closed.

[0042] If the difference is greater than or equal to the certain value, the second drainage air control valve 16 is closed, and when the difference is less than or equal to the set target difference, the second drainage air control valve 16 is opened in a pulse mode.

[0043] Working principle:

[0044] Two sets of double-valve control are adopted, which can adapt to the situation of electrolytic cell 1 under high pressure and low pressure at the same time to meet the pressure fluctuation, one needle valve has a small opening degree, which is suitable for high pressure drainage, and the water in the cathode separator 3 will not be immediately emptied, thereby causing a large pressure fluctuation, two needle valves, i.e. the first drainage needle valve 13 and the second drainage needle valve 15, have a large opening degree, which is suitable for low pressure drainage, and the water in the cathode separator 3 will not be drained too slowly, causing the drained water to be lower than the hydrogen side permeated water in the electrolytic cell 1, resulting in a high liquid level in the separation tank, if the needle valve has a small opening degree, it will still cause the high pressure drainage to be too fast, thereby causing a large pressure fluctuation, and an intermittent, i.e. pulse, drainage method can be used, the drainage air control valve is started and stopped continuously during drainage, thereby slowing down the drainage rate and reducing the pressure fluctuation.

[0045] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A PEM high pressure electrolyzer hydrogen side drainage pressure regulating device, characterized in that, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

2. The hydrogen side drainage pressure regulating device for a PEM high pressure electrolyzer of claim 1, wherein, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

3. The hydrogen side drainage pressure regulating device for a PEM high pressure electrolyzer of claim 1, wherein, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

4. The hydrogen side drainage pressure regulating device for a PEM high pressure electrolyzer of claim 1, wherein, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

5. The hydrogen side drainage pressure regulating device for a PEM high pressure electrolyzer of claim 1, wherein, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

6. The PEM high pressure electrolyzer hydrogen side water drainage pressure regulating device according to claim 1, characterized in that, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

7. The PEM high pressure electrolyzer hydrogen side water drainage pressure regulating device according to claim 2, characterized in that, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

8. The PEM high pressure electrolyzer hydrogen side water drainage pressure regulating device according to claim 1, characterized in that, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

9. The PEM high pressure electrolyzer hydrogen side water drainage pressure regulating device of claim 1, wherein, The cathode separator is connected with a cathode exhaust pipeline, the cathode exhaust pipeline comprises two parallel branch pipelines, each of which is provided with a needle valve and an air control valve, and the cathode separator is provided with a cathode differential pressure liquid level meter.

10. A PEM high pressure electrolyzer hydrogen side water drainage pressure regulating system, characterized in that, ​

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