Pressure-adjustable multichannel water electrolysis testing device

Abstract

The invention discloses a pressure-adjustable multi-channel water electrolysis testing device which comprises a plurality of electrolytic cells which are arranged in parallel and have the same structure and design, and an output pipeline of each electrolytic cell is connected with a normal-pressure branch switch valve and a back-pressure branch switch valve. The output end of the normal-pressure branch switch valve is connected with the normal-pressure hydrogen outlet; wherein the output end of the backpressure branch switch valve is connected with the gas-liquid separator, one output port of the gas-liquid separator is connected with the high-pressure hydrogen outlet through the pressure regulating valve, and the other output port of the gas-liquid separator is connected with the liquid outlet of the gas-liquid separation tank through the liquid level regulating valve. When the normal-pressure mode is selected, hydrogen is directly discharged to the atmosphere through the normal-pressure branch and the emptying pipeline; when the back pressure mode is selected, hydrogen enters the gas-liquid separator through the back pressure branch, separated liquid gathers in the separator, and when the current pressure sensor detects that the system pressure reaches a set value, an instruction is sent to adjust the opening degree of the pressure adjusting valve, the system pressure value is constant, and it is guaranteed that the electrolytic cell operates under the stable set pressure working condition.

Description

Technical Field

[0001] The invention relates to the field of proton exchange membrane (PEM) testing, and in particular discloses a pressure-adjustable multi-channel water electrolysis testing device. Background Art

[0002] The water electrolysis test device is an important test equipment for evaluating the performance of membrane electrodes. The test device is generally divided into a single-channel test device and a multi-channel test device. The single-channel test device is mainly used for the performance evaluation of membrane electrodes and key materials; the multi-channel test device is mainly used for the durability evaluation of membrane electrodes. It is generally developed to improve the test efficiency and integrates multiple single channels into one to meet the needs of simultaneous testing of multiple electrolyzers. The main function of the water electrolysis test device is to provide the electrolyzer to be tested with a constant temperature, pressure and flow rate of the reaction material supply, and to achieve gas-liquid separation and pressure control of the electrolyzer product. In order to reduce the compression energy consumption of hydrogen at the back end, the current industrial-grade electrolyzer generally operates under a certain pressure. The pressure operation will affect the performance and durability of the membrane electrode. Therefore, in the membrane electrode development stage, for the real reaction membrane electrode operating conditions, the water electrolysis test device needs to have a pressure control function. The current water electrolysis test device function is mainly concentrated in temperature and flow control. How to achieve the regulation of different pressure conditions such as normal pressure and back pressure, especially for multi-channel test devices, is still not accurate enough for the pressure regulation process. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention discloses a pressure-adjustable multi-channel water electrolysis test device. The pressure control logic of the device is simple and reliable. It is not necessary to set a pressure control unit separately for each channel. The pressure control of multiple channels is integrated into a pressure control unit, which reduces the use of high-cost components such as pressure vessels and back pressure valves, and can effectively reduce the manufacturing cost of the pressure-type multi-channel test device. It is easy to realize the independent and free selection of the normal pressure mode and the back pressure mode of each test channel of the multi-channel test bench. The specific technical solution includes:

[0004] A plurality of electrolyzers of the same structure and design are arranged in parallel, wherein the output pipeline of each electrolyzer is connected with a normal pressure branch switch valve and a back pressure branch switch valve, wherein the output end of the normal pressure branch switch valve is connected with the normal pressure hydrogen outlet; wherein the output end of the back pressure branch switch valve is connected with a gas-liquid separator, wherein one output port of the gas-liquid separator is connected with the high pressure hydrogen outlet via a pressure regulating valve, and the other output port is connected with the liquid outlet of the gas-liquid separation tank via a liquid level regulating valve;

[0005] Under working condition: hydrogen is generated at the cathode of the electrolyzer during the electrolysis process, and the hydrogen is discharged from the electrolyzer through the pipeline. When the normal pressure mode is selected for the electrolyzer, the normal pressure branch switch valve is opened, and the back pressure branch switch valve is closed. The hydrogen is discharged directly from the hydrogen pipeline outlet to the atmosphere through the normal pressure branch; when the back pressure mode is selected for the electrolyzer, the normal pressure branch switch valve is closed, and the back pressure branch switch valve is opened. The hydrogen reaches the gas-liquid separator through the back pressure branch for gas-liquid separation. The dried hydrogen after separation is discharged through the pipeline at the upper end of the tank body. At the beginning, the pressure regulating valve is in a closed state. When the hydrogen production in the system increases, the gas pressure gradually increases. When the system pressure reaches the set pressure target value, the control instruction is transmitted to the pressure regulating valve, and the opening of the pressure regulating valve is adjusted to control the pressure to remain within the set pressure value range, so that the system operates under stable back pressure conditions.

[0006] Furthermore, a pressure sensor is provided on the connecting pipeline between the gas-liquid separator and the pressure regulating valve. When the hydrogen production in the system increases and the gas pressure rises, the pressure sensor monitors the pressure information of the hydrogen on the output pipeline of the gas-liquid separator in real time. When the pressure reaches a preset value, the opening of the pressure regulating valve is controlled to maintain the system at a constant pressure, thereby realizing back pressure operation.

[0007] Furthermore, a liquid level switch valve is provided on the connecting pipeline between the gas-liquid separator and the liquid outlet of the gas-liquid separation tank. The liquid level switch valve is opened when the liquid level is higher than the upper limit, and is closed when the liquid level is lower than the lower limit.

[0008] Due to the adoption of the above-mentioned technical scheme, the present invention provides a pressure-adjustable multi-channel water electrolysis testing device, which can realize that each channel of the multi-channel electrolytic cell has two operating modes, namely, normal pressure mode and back pressure mode, and independently and freely selects, so as to realize the testing of the electrolytic cell under different pressure conditions. In addition, the pressure control strategy proposed by the present invention is simple and easy to implement, and the independent back pressure control units of multiple channels are integrated into one pressure control unit, which greatly reduces the use of high-cost components such as pressure vessels and back pressure valves, and can greatly reduce the manufacturing cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0010] Figure 1 The structure diagram of the pressure-adjustable multi-channel water electrolysis test device of the present invention

[0011] In the figure: 101, the first electrolytic cell unit, 201, the second electrolytic cell unit, 301, the third electrolytic cell unit, 101.1, the first normal pressure branch switch valve, 101.2, the first back pressure branch switch valve, 101.3, the first normal pressure branch needle valve, 401, the gas-liquid separation tank, 401.4, the high pressure hydrogen outlet, 401.3, the liquid level regulating valve, 401.5, the gas-liquid separation tank liquid outlet, 401.1, the pressure sensor, 401.2, the pressure regulating valve, 501, the hydrogen pipeline outlet, 201.1, the second normal pressure branch switch valve, 201.2, the second back pressure branch switch valve, 201.3, the second normal pressure branch needle valve, 301.1, the third normal pressure branch switch valve, 301.2, the third back pressure branch switch valve, 301.3, the third normal pressure branch needle valve. DETAILED DESCRIPTION

[0012] In order to make the technical solutions and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention:

[0013] like Figure 1 The present invention shown provides a multi-channel water electrolysis test device with adjustable pressure, each channel of the multi-channel test device is provided with an electrolytic cell, material water is introduced into the anode side of the electrolytic cell as a reactant, a DC power supply provides current and voltage, a water electrolysis reaction occurs inside the electrolytic cell, oxygen is generated on the anode side of the electrolytic cell, and hydrogen is generated on the cathode side. The hydrogen generated on the cathode side of the electrolytic cell is discharged from the electrolytic cell through the main line, the main line is subdivided into two branches, and a switch valve is provided in each of the two branches, so that the opening and closing states of the switch valves of the two branches are inconsistent, so that the hydrogen generated by the reaction enters different branches, and then enters the normal pressure mode or the back pressure mode. When the normal pressure mode is selected, hydrogen is directly discharged into the atmosphere through the normal pressure branch and the vent pipeline; when the back pressure mode is selected, hydrogen enters the gas-liquid separator through the back pressure branch, and the separated liquid gathers in the separator. When the set liquid level value is reached, the liquid level switch valve 401.3 is opened to discharge the liquid from the separator. When the liquid level reaches the set liquid level low point, the liquid level switch valve 401.3 is closed to prevent the internal gas from being discharged from the separator from the liquid outlet at the lower end of the separator. The separated and dried hydrogen is discharged from the pipeline at the upper end of the separator. A pressure sensor and a pressure regulating valve are arranged on the discharge pipeline. When the current pressure sensor detects that the system pressure reaches the set value, it sends a command to adjust the opening of the pressure regulating valve to achieve a constant system pressure value, thereby ensuring that the electrolyzer operates under a stable set pressure condition.

[0014] Specific details are as follows:

[0015] This embodiment takes a three-channel PEM water electrolysis test system as an example to illustrate the pressure control strategy. The entire control scheme process flow is divided into 4 unit structures, the specific structure is shown in the attached Figure 1As shown, the unit structure mainly includes three parallel-connected first electrolytic cell units 101 , second electrolytic cell units 201 , third electrolytic cell units 301 and a gas-liquid separation and back pressure control unit 401 . The output end of the first electrolyzer unit 101 is connected to the first normal-pressure branch switch valve 101.1, wherein the first normal-pressure branch switch valve 101.1 is connected to the first normal-pressure branch needle valve 101.3, and the first normal-pressure branch needle valve 101.3 is connected to the hydrogen pipeline outlet 501, wherein the other output end of the first electrolyzer unit 101 is connected to the first back-pressure branch switch valve 101.2, wherein the output end of the first back-pressure branch switch valve 101.2 is connected to the gas-liquid separator 401, one output port of the gas-liquid separator 401 is connected to the high-pressure hydrogen outlet 401.4 through the pressure regulating valve 401.2, and the other output port is connected to the liquid outlet 401.5 of the gas-liquid separation tank through the liquid level regulating valve 401.3, and a pressure sensor 401.1 and a pressure regulating valve 401.2 are arranged on the connecting pipeline of the pressure regulating valve 401.2.

[0016] The second electrolytic cell unit 201 adopts the same connection method as the first electrolytic cell unit 101, wherein one output end of the second electrolytic cell unit 201 is connected to the second normal pressure branch switch valve 201.1, the second normal pressure branch switch valve 201.1 is connected to the second normal pressure branch needle valve 201.3, and the other output end of the second electrolytic cell unit 201 is connected to the second back pressure branch switch valve 201.2. The third electrolyzer unit 301 adopts the same connection method as the first electrolyzer unit 101, wherein one output end of the third electrolyzer unit 301 is connected to the third normal pressure branch switch valve 301.1, and the third normal pressure branch switch valve 301.1 is connected to the third normal pressure branch needle valve 301.3, and the other output end of the third electrolyzer unit 301 is connected to the third back pressure branch switch valve 301.2, wherein the second normal pressure branch needle valve 201.3 and the third normal pressure branch needle valve 301.3 are both connected to the hydrogen pipeline outlet 501.

[0017] The pressure control scheme of the first electrolyzer unit 101 is now described: the cathode of the electrolyzer generates hydrogen during the electrolysis process, and the hydrogen is discharged from the electrolyzer through the pipeline. When the normal pressure mode is selected for the first electrolyzer unit 101, the first normal pressure branch switch valve 101.1 is opened, the first back pressure branch switch valve 101.2 is closed, and the hydrogen is directly discharged from the hydrogen pipeline outlet 501 to the atmosphere through the normal pressure branch; when the back pressure mode is selected for the first electrolyzer 101, the first normal pressure branch switch valve 101.1 is closed, the first back pressure branch switch valve 101.2 is opened, and the hydrogen reaches the gas-liquid separator 4 through the back pressure branch. 01 performs gas-liquid separation, and the dried hydrogen after separation is discharged through the pipeline at the upper end of the tank body. Since a pressure sensor 401.1 and a pressure regulating valve 401.2 are provided on the discharge pipeline, the pressure regulating valve 401.2 is in a closed state at the beginning. When the hydrogen production in the system gradually increases and the gas pressure gradually increases, the pressure sensor 401.1 detects that the system pressure reaches the set pressure target value, and transmits the control instruction to the pressure regulating valve 401.2, automatically adjusting the opening of the 401.2 pressure regulating valve to maintain the system pressure at the set pressure value, so that the entire system operates under stable back pressure conditions. A liquid level sensor is provided in the gas-liquid separator 401. When the liquid level in the tank body reaches the preset upper limit, the liquid level switch valve 401.3 is controlled to discharge the liquid from the gas-liquid separator. When the liquid level reaches the preset lower limit, the liquid level switch valve 401.3 is closed. It is worth noting that a certain liquid level should be maintained in the gas-liquid separator 401, and the liquid cannot be emptied to ensure the sealing of the system. The above control scheme can realize the independent and free selection of normal pressure and back pressure modes of the multi-channel electrolyzer. It should be noted that the function of the first normal pressure branch needle valve 101.3, the second normal pressure branch needle valve 201.3, and the third normal pressure branch needle valve 301.3 is to prevent the impact of high pressure gas on the pipeline when the normal pressure branch switch valve is opened when the high pressure mode is switched to the normal pressure mode.

[0018] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A pressure-adjustable multi-channel water electrolysis test device, characterized in that include: A plurality of electrolyzers of the same structure and design are arranged in parallel, wherein the output pipeline of each electrolyzer is connected with a normal pressure branch switch valve and a back pressure branch switch valve, wherein the output end of the normal pressure branch switch valve is connected with the normal pressure hydrogen outlet; wherein the output end of the back pressure branch switch valve is connected with a gas-liquid separator, wherein one output port of the gas-liquid separator is connected with the high pressure hydrogen outlet through a pressure regulating valve, and the other output port is connected with the liquid outlet of the gas-liquid separation tank; Under working condition: hydrogen is generated at the cathode of the electrolyzer during the electrolysis process, and the hydrogen is discharged from the electrolyzer through the pipeline. When the normal pressure mode is selected for the electrolyzer, the normal pressure branch switch valve is opened, and the back pressure branch switch valve is closed. The hydrogen is discharged directly from the hydrogen pipeline outlet to the atmosphere through the normal pressure branch; when the back pressure mode is selected for the electrolyzer, the normal pressure branch switch valve is closed, and the back pressure branch switch valve is opened. The hydrogen reaches the gas-liquid separator through the back pressure branch for gas-liquid separation. The dried hydrogen after separation is discharged through the pipeline at the upper end of the tank body. At the beginning, the pressure regulating valve is in a closed state. When the hydrogen production in the system increases, the gas pressure gradually increases. When the system pressure reaches the set pressure target value, the control instruction is transmitted to the pressure regulating valve, and the opening of the pressure regulating valve is adjusted to control the pressure to remain within the set pressure value range, so that the system operates under stable back pressure conditions.

2. A pressure-adjustable multi-channel water electrolysis testing device according to claim 1, characterized in that: A pressure sensor is provided on the connecting pipeline between the gas-liquid separator and the pressure regulating valve. When the hydrogen production in the system increases and the gas pressure rises, the pressure sensor monitors the pressure information of the hydrogen on the output pipeline of the gas-liquid separator in real time. When the pressure reaches a preset value, the opening of the pressure regulating valve is controlled to maintain the system at a constant pressure, thereby realizing back pressure operation.

3. The pressure-adjustable multi-channel water electrolysis testing device according to claim 1, characterized in that: A liquid level switch valve is provided on the connecting pipeline between the gas-liquid separator and the liquid outlet of the gas-liquid separation tank. The liquid level switch valve is opened when the liquid level is higher than the upper limit, and is closed when the liquid level is lower than the lower limit.

4. The pressure-adjustable multi-channel water electrolysis testing device according to claim 1, characterized in that: The normal pressure branch switch valve is connected to the normal pressure branch needle valve, and the normal pressure branch needle valve is connected to the hydrogen pipeline outlet.

5. The pressure-adjustable multi-channel water electrolysis testing device according to claim 1, characterized in that: A liquid level regulating valve is arranged on the other output port of the gas-liquid separator, and the liquid level regulating valve is connected to the liquid outlet of the gas-liquid separation tank.

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