A diaphragm bubble point test apparatus and method for simulating alkaline electrolysis operating conditions

Abstract

A kind of diaphragm bubble point test device and method for simulating alkaline electrolysis working condition, including the first component (1) and the second component (2) located at the two sides of the diaphragm to be measured, sealing gasket (6) is arranged between the two, and the diaphragm to be measured is clamped to form first cavity (12) and second cavity (21);First cavity is provided with observation / liquid injection opening, second cavity is provided with air inlet assembly (22), liquid discharge assembly (23) and pressure detection assembly (24);First polar plate (13) and second polar plate (25) are respectively arranged in first cavity and second cavity and are connected with external power supply, for electrolysis treatment to diaphragm;When the device tests, first electrolyte is injected into two cavities, electrolysis is carried out under set current density or voltage, after electrolysis, external power supply is turned off and electrolyte in second cavity is emptied, then gas is introduced into second cavity to gradually pressurize, bubble condition is observed through first cavity side and corresponding pressure is read, that is, diaphragm bubble point pressure.

Description

Technical Field

[0001] This invention belongs to the field of alkaline water electrolysis for hydrogen production diaphragm testing technology, specifically relating to a diaphragm bubble point testing device and method for simulating electrolysis conditions. This invention can reflect the bubble point behavior of the diaphragm under electrolysis conditions. Background Technology

[0002] The diaphragm is one of the key components of an alkaline water electrolysis hydrogen production electrolyzer. Its main functions include isolating the anode and cathode to inhibit hydrogen-oxygen cross-linking and conducting OH- under alkaline conditions. - And maintain electronic insulation. Bubble point pressure is an important parameter characterizing the gas barrier capability of the diaphragm, usually obtained by pressurizing gas on one side of the diaphragm and observing the pressure of bubbles appearing on the other side. However, in actual electrolysis, the diaphragm is subjected to the coupled influence of multiple factors such as strong alkali wetting, electric field effect, and electrode gas evolution scouring. Its pore wetting state, interfacial tension, and surface attached bubbles differ from those of conventional static bubble point test conditions, resulting in a deviation between laboratory bubble point results and the effective gas barrier capability under electrolytic cell operating conditions. Existing bubble point testing devices usually only perform static pressure bubble formation judgment and lack the ability to pre-treat the diaphragm under electrolysis in the same clamping state and then measure the bubble point, thus making it difficult to obtain bubble point evaluation results that are closer to actual operating conditions. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a testing device for the bubble point of a water electrolysis membrane used to simulate electrolysis conditions. When testing the bubble point of a water electrolysis membrane under electrolysis conditions, this device first electrolyzes the membrane and then performs a bubble point test on the treated membrane. This simulates the wetting, electric field, and gas evolution effects of the membrane under electrolysis conditions, thereby improving the consistency between the bubble point test results and actual electrolysis conditions.

[0004] Specifically, the first aspect of the present invention is to provide a membrane bubble point testing device for simulating alkaline electrolysis conditions, comprising, in sequence, a first component (1), a second component (2), a sealing gasket (6) for clamping the membrane (7) to be tested, and a fastening assembly; the first component (1) and the second component (2) are arranged opposite to each other and abut against each other under the action of the fastening assembly, so that the sealing gasket (6) clamps the membrane (7) to be tested and forms a first cavity (12) and a second cavity (21) located on both sides of the membrane; the first component (1) is provided with a connection to the first cavity (12). The first cavity (12) has an observation / injection opening (11); the second component (2) is provided with an air intake assembly (22), a pressure detection assembly (24), and a drain assembly (23) communicating with the second cavity (21); the first cavity (12) is provided with a first electrode plate (13), and the second cavity (21) is provided with a second electrode plate (25). The first electrode plate (13) and the second electrode plate (25) are respectively provided with conductive terminals or tabs that are electrically connected to an external power supply, for applying an electric field in the first cavity (12) and the second cavity (21) to construct an electrolysis test environment. The drain assembly (23) is used to drain the electrolyte in the second cavity (21) after electrolysis and switch the second cavity (21) into a pressurized gas chamber. The air intake assembly (22) and the pressure detection assembly (24) are used to introduce gas into the second cavity (21) and monitor the pressure for bubble point testing.

[0005] Preferably, the sealing gasket (6) is an alkali-resistant sealing gasket, and at least one sealing gasket (6) is provided on both sides of the diaphragm (7) to achieve liquid tightness and air tightness sealing.

[0006] Preferably, the first electrode plate (13) and / or the second electrode plate (25) are porous plates, mesh plates or perforated plates, used to realize current distribution and provide an exhaust channel for the gas generated by electrolysis, while providing support for the diaphragm (7) to be tested to reduce deformation during the pressurization process.

[0007] Preferably, the air intake assembly (22) is connected to the air source and includes a valve and a flow regulating component; the pressure detection assembly (24) includes a pressure gauge or a pressure sensor, and preferably also includes a safety pressure relief component.

[0008] Preferably, the drainage assembly (23) is disposed at the lower part of the second component (2) and communicates with the second cavity (21). The drainage assembly (23) includes a drainage channel and a valve for injecting, draining or changing the liquid.

[0009] Preferably, the fastening assembly includes a bolt (3), a nut (4), and a washer (5). The bolt (3) passes through the mounting holes corresponding to the first component (1) and the second component (2) and is locked under a preset torque.

[0010] A second aspect of the present invention is to provide a method for performing bubble point testing under simulated electrolysis conditions using the testing apparatus of the first aspect of the present invention, comprising the following steps: (1) Place the diaphragm (7) to be tested between the first component (1) and the second component (2), seal it with the sealing gasket (6) and lock the fastening assembly under a preset torque, so that the device forms the first cavity (12) and the second cavity (21). (2) Electrolyte is injected into the first cavity (12) and the second cavity (21) respectively, so that both sides of the diaphragm (7) to be tested are fully wetted by the electrolyte, and the air intake assembly (22) or the pressure detection assembly (24) is in a state where it can be vented so that the gas generated by electrolysis can be discharged. (3) Connect the external power supply to the first electrode plate (13) and the second electrode plate (25) and perform electrolysis under the set current density or voltage conditions for a continuous electrolysis time t; (4) After turning off the external power supply and stopping the electrolytic pretreatment, open the drain assembly (23) to drain the electrolyte in the second cavity (21), then close the drain assembly (23) and keep the electrolyte in the first cavity (12) continuously covering and wetting the diaphragm; (5) Open the air intake assembly (22) and the pressure detection assembly (24) to introduce gas into the second cavity (21) at a preset pressure rise rate and gradually increase the pressure; (6) Observe the bubble formation of the diaphragm on the first cavity (12) side by observing / injection opening (11). When bubbles appear and continuous bubble formation is guided, read the corresponding pressure value of the pressure detection component (24) as the bubble point pressure of the diaphragm after pretreatment under simulated electrolysis conditions.

[0011] Compared with the prior art, the present invention has at least the following beneficial effects: (1) It can introduce the effects of wetting, electric field and gas evolution in the actual electrolysis process, so that the bubble point result is closer to the electrolysis working condition; (2) The draining component allows the second cavity to be switched from the electrolyte cavity to the pressurized gas cavity without disassembly, thereby improving the operating efficiency and safety. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the diaphragm bubble point testing device for simulating alkaline electrolysis conditions provided in this application; Figure 2 This is a schematic diagram of the diaphragm bubble point testing device for simulating alkaline electrolysis conditions provided in this application after installation. Figure 3 This is a schematic diagram of the first component (1) of the diaphragm bubble point testing device for simulating alkaline electrolysis conditions provided in this application.

[0013] exist Figure 1 and Figure 3In the process, the device sequentially includes a first component (1), a sealing gasket (6), a diaphragm to be tested (7), a second component (2), a bolt (3), a nut (4), a washer (5), and a sealing gasket (6); The lower part of the first component (1) and the upper part of the second component (2) are provided with holes for inserting bolts (3). The bolts (3), nuts (4), and washers (5) are used to connect the first component (1) and the second component (2), so that the first component (1) and the second component (2) abut against each other, and the sealing gasket (6) clamps the diaphragm to be tested (7). The first component (1) includes a first opening (11), a first cavity (12), and a first electrode plate (13); like Figure 3 As shown, the first electrode plate (13) is disposed at the lower part of the first component (1) and connected to the first component (1); The second component (2) includes a second cavity (21), an air intake assembly (22), a drainage assembly (23), a pressure detection assembly (24), and a second electrode plate (25); The second electrode plate (25) is connected to the second component (2) at the upper part of the second component (2). The inflation assembly is connected to the second cavity (21). Gas is injected into the second cavity (21) by an air pump. The inflation speed of the inflation assembly is adjustable and a valve is provided to control the gas flow. The drainage assembly (23) is connected to the second component (2) at the lower part of the second component (2) and communicates with the second cavity (21), and is equipped with a valve to control the passage of gas and liquid; The pressure detection component is connected to the second cavity (21), and a pressure gauge is connected to the top. A valve is provided to control the airflow. The bolt (3), nut (4), and washer (5) are used to connect the first component (1) and the second component (2). The bolt (3), nut (4), and washer (5) are tightened to a fixed torque by a torque wrench. The sealing gasket (6) is used to seal the diaphragm (7) to be tested. Detailed Implementation Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0014] The following description, with reference to the accompanying drawings, describes a diaphragm bubble point testing apparatus and method for simulating alkaline electrolysis conditions according to an embodiment of the present invention.

[0015] Example 1: Device Structure Reference Figures 1 to 3A membrane bubble point testing device for simulating electrolysis conditions includes, in sequence, a first component (1), a sealing gasket (6), a membrane to be tested (7), a second component (2), and a fastening assembly. The first component (1) and the second component (2) are arranged opposite to each other and are locked under a preset torque by bolts (3), nuts (4), and washers (5), so that the sealing gasket (6) clamps the membrane and forms a first cavity (12) and a second cavity (21). The first component (1) is provided with an observation / liquid injection opening (11) communicating with the first cavity; the second component (2) is provided with an air inlet assembly (22), a liquid drain assembly (23), and a pressure detection assembly (24) communicating with the second cavity.

[0016] In some embodiments, the sealing gasket (6) may be a gasket made of PTFE, EPDM, FKM or other alkali-resistant elastomer materials; the first component (1) and the second component (2) may be made of stainless steel, nickel or other alkali-resistant and pressure-resistant materials; In some embodiments, the first electrode plate (13) and the second electrode plate (25) may be nickel plates, nickel mesh, stainless steel porous plates or other alkali-resistant conductive materials, and preferably adopt a porous / mesh structure to facilitate the discharge of electrolytic gas and uniform pressure transmission; the electrode plates can be connected to an external power supply or electrochemical workstation through electrode tabs.

[0017] In some embodiments, the air intake assembly (22) includes a valve and a flow regulating component connected to the air source; the pressure detection assembly (24) includes a pressure gauge or a pressure sensor, and preferably includes a safety pressure relief component to avoid overpressure; the drain assembly (23) is located at the lower part of the second component and includes a drain channel and a valve for injecting, draining or changing liquid.

[0018] The structure of the diaphragm bubble point testing device for simulating alkaline electrolysis conditions described above after installation is as follows: Figure 2 As shown.

[0019] Example 2: Bubble point test method after electrolytic treatment (1) Clamping: Place the diaphragm (7) to be tested between the first component (1) and the second component (2), clamp the sealing gasket (6), tighten the bolts (3) in a diagonal sequence, and lock it under the preset torque to form the first cavity (12) and the second cavity (21).

[0020] (2) Injection and wetting: Electrolyte is injected into the first cavity and the second cavity respectively to fully wet both sides of the diaphragm. In order to avoid gas accumulation in the cavity during the electrolysis stage, in some embodiments the air intake assembly (22) or pressure detection assembly (24) can be kept in an exhaust-enabled state (e.g., a valve is slightly opened or a one-way exhaust passage is set).

[0021] (3) Electrolytic pretreatment: Connect the external power supply to the first electrode plate (13) and the second electrode plate (25) and perform electrolytic pretreatment in a constant current or constant voltage manner for a preset electrolysis time of 10 hours; turn off the external power supply after the pretreatment is completed.

[0022] (4) Drainage and mode switching: Open the drain assembly (23) to drain the electrolyte in the second cavity (21) and then close the valve to switch the second cavity to a pressurized gas chamber; at the same time, keep the electrolyte in the first cavity (12) covering the diaphragm to maintain the wetting conditions required for bubble point testing.

[0023] (5) Pressure test: Open the air intake assembly (22) and monitor the pressure through the pressure detection assembly (24). Gradually increase the pressure at the preset pressure rise rate. Observe the foaming situation on the first cavity side through the observation / liquid injection opening (11). When continuous foaming occurs, read the pressure value as the bubble point pressure after electrolytic pretreatment.

[0024] In some embodiments, the electrolyte may be a KOH solution with a concentration of, for example, 10 wt% to 40 wt%, and the test temperature may be 20 to 90 °C. Electrolytic pretreatment may be performed at 1000 to 5000 A / m 2 The current density range or equivalent voltage conditions can be used to preset the electrolysis time t, which can be 0-720 h.

[0025] Example 3: Bubble point test under different electrolytic pretreatment times In some embodiments, the electrolyte composition (30 wt% KOH), temperature (80 °C), and current density (1000 A / m) can be maintained. 2 Under the condition of keeping the process constant, only the electrolysis treatment time t was changed, and the corresponding bubble point pressure was measured to evaluate the effect of pretreatment under working conditions on the gas barrier capacity of the diaphragm.

[0026]

[0027] Table 1. Bubble point test results of a commercial PPS diaphragm under different electrolytic pretreatment times. Based on the results of the above embodiments, it can be seen that the present invention can achieve the following technical effects: (1) The test device of the present invention has a simple structure; (2) When the device is used, the electrolytic pretreatment can introduce the effects of wetting, electric field and gas evolution in the actual electrolysis process, so that the bubble point result is closer to the electrolysis working condition; (3) The device is easy to use and can improve the operating efficiency and safety.

[0028] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0029] The above description is only a preferred embodiment of the present invention. For those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A membrane bubble point testing device for simulating alkaline electrolysis conditions, comprising, in sequence, a first component (1), a second component (2), a sealing gasket (6) for clamping the membrane (7) to be tested, and a fastening assembly; the first component (1) and the second component (2) are arranged opposite to each other and abut against each other under the action of the fastening assembly, so that the sealing gasket (6) clamps the membrane (7) to be tested and forms a first cavity (12) and a second cavity (21) located on both sides of the membrane; the first component (1) is provided with an observation / liquid injection opening communicating with the first cavity (12). The first cavity (12) is equipped with an air intake assembly (22), a pressure detection assembly (24), and a drain assembly (23) communicating with the second cavity (21). The first cavity (12) is equipped with a first electrode plate (13), and the second cavity (21) is equipped with a second electrode plate (25). The first electrode plate (13) and the second electrode plate (25) are respectively equipped with conductive terminals or tabs that are electrically connected to an external power supply, for applying an electric field in the first cavity (12) and the second cavity (21) to construct an electrolysis test environment. The drain assembly (23) is used to drain the electrolyte in the second cavity (21) after electrolysis and switch the second cavity (21) into a pressurized gas chamber. The air intake assembly (22) and the pressure detection assembly (24) are used to introduce gas into the second cavity (21) and monitor the pressure for bubble point testing.

2. The testing apparatus according to claim 1, characterized in that, The sealing gasket (6) is an alkali-resistant sealing gasket, and at least one sealing gasket (6) is provided on both sides of the diaphragm (7) to achieve liquid tightness and air tightness sealing.

3. The testing apparatus according to claim 1, characterized in that, The first electrode plate (13) and / or the second electrode plate (25) are porous plates, mesh plates or perforated plates, used to realize current distribution and provide an exhaust channel for the gas generated by electrolysis, while providing support for the diaphragm (7) to be tested to reduce deformation during the pressurization process.

4. The testing apparatus according to claim 1, characterized in that, The air intake assembly (22) is connected to the air source and includes a valve and a flow regulating component; the pressure detection assembly (24) includes a pressure gauge or a pressure sensor, and preferably also includes a safety pressure relief component.

5. The testing apparatus according to claim 1, characterized in that, The drainage assembly (23) is located at the lower part of the second component (2) and communicates with the second cavity (21). The drainage assembly (23) includes a drainage channel and a valve for injecting, draining or changing the liquid.

6. The testing apparatus according to claim 1, characterized in that, The fastening assembly includes a bolt (3), a nut (4) and a washer (5). The bolt (3) passes through the mounting holes corresponding to the first component (1) and the second component (2) and is locked under a preset torque.

7. A method for bubble point testing using the apparatus according to any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Place the diaphragm (7) to be tested between the first component (1) and the second component (2), seal it with the sealing gasket (6) and lock the fastening assembly under a preset torque, so that the device forms the first cavity (12) and the second cavity (21). (2) Inject electrolyte into the first cavity (12) and the second cavity (21) respectively, so that both sides of the diaphragm (7) to be tested are fully wetted by electrolyte, and put the air intake assembly (22) or the pressure detection assembly (24) into an exhaust state so that the gas generated by electrolysis can be discharged. (3) Connect the external power supply to the first electrode plate (13) and the second electrode plate (25) and perform electrolysis under the set current density or voltage conditions for a continuous electrolysis time t. (4) After turning off the external power supply and stopping the electrolysis process, open the drain assembly (23) to drain the electrolyte in the second cavity (21), then close the drain assembly (23) and keep the electrolyte in the first cavity (12) continuously covering and wetting the diaphragm; (5) Open the air intake assembly (22) and the pressure detection assembly (24) to introduce gas into the second cavity (21) at a preset pressure rise rate and gradually increase the pressure; (6) Observe the bubble formation of the diaphragm on the first cavity (12) side by observing / injection opening (11). When bubbles appear and continuous bubble formation is guided, read the corresponding pressure value of the pressure detection component (24) as the bubble point pressure of the diaphragm after pretreatment under simulated electrolysis conditions.

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