A method for troubleshooting a PEM electrolyzer based on short-circuiting of polar plates

Abstract

The present invention provides a PEM electrolyzer fault handling method based on plate short-circuiting, comprising: S1 modeling the PEM electrolyzer plate; S2 evaluating the assembly state of the PEM electrolyzer, confirming the plate area, area and spacing that can be short-circuited; S3 selecting the short-circuiting material; S4 confirming the boundary conditions of the electrothermal coupling simulation; S5 screening out the best short-circuiting scheme; S6 locating the position of the faulty electrolytic chamber and cleaning the faulty area; S7 connecting the short-circuiting areas of the plates on both sides of the faulty electrolytic chamber using the best short-circuiting scheme; S8 after the short-circuiting is completed, using a detergent to clean the connection area, and then reinstalling and operating the PEM electrolyzer to ensure that the fault has been resolved. The present invention short-circuits the plates on both sides of the abnormal electrolytic chamber on the faulty PEM electrolyzer, actively shuts down the reaction capacity of the electrolytic chamber, effectively handles the problem of low performance of some electrolytic chambers of the PEM electrolyzer, and reduces the safety risk of the operation of the PEM electrolyzer.

Description

Technical Field

[0001] The invention belongs to the technical field of basic electrical component fault processing, and in particular relates to a PEM electrolyzer fault processing method based on polar plate short circuit. Background Art

[0002] As the core component of the entire PEM water electrolysis hydrogen production system, the PEM electrolyzer is the only place where the power-to-gas chemical reaction occurs. It is composed of membrane electrodes, gas diffusion layers, metal plates, current collectors, and end plates. During the operation of the PEM electrolyzer, some electrolysis chambers may experience abnormal conditions such as low performance, which will affect the overall operating efficiency and life of the PEM electrolyzer and increase the safety risks of the PEM electrolyzer operation.

[0003] The existing technology is to dismantle the PEM electrolyzer to repair the abnormal electrolytic chamber to avoid further deterioration of the state of the PEM electrolyzer. However, as a way to handle PEM electrolyzer faults, dismantling and repairing is difficult to implement, has a low fault tolerance rate, and has high risks in the implementation process. During the disassembly and assembly process, the PEM electrolyzer relaxes and re-tightens, and the normal state of the electrolytic chamber may deteriorate. In particular, after the PEM electrolyzer relaxes, the swollen membrane electrode may lose restraint and expand freely, causing wrinkles in the membrane electrode during the re-tightening process, resulting in attenuation of the electrolytic chamber performance and even hot spots that pose safety risks. In addition, repeated disassembly and assembly will also affect the sealing of the PEM electrolyzer, which may cause the working pressure of the PEM electrolyzer to fail to reach the level before dismantling.

[0004] Patent CN103898554A discloses a method for quickly eliminating short circuits in magnesium electrolytic cells. When the voltage of the magnesium electrolytic cell is more than 10% lower than the voltage of the magnesium electrolytic cell under normal conditions or when the current intensity of each electrode in the magnesium electrolytic cell differs by more than 5%, inert gas is blown into the gaps between the electrodes in the magnesium electrolytic cell to effectively solve the local short circuit problem in the magnesium electrolytic cell. However, this method is only applicable to the treatment of short circuit faults in magnesium electrolytic cells and is not a universal method for the treatment of various electrolytic cell faults. Since the structure of the PEM electrolytic cell is different from that of the magnesium electrolytic cell, the causes of the abnormal voltage are also different. Therefore, this method cannot be applied to the treatment of abnormal voltage faults in the small chambers of the PEM electrolytic cell. Summary of the invention

[0005] In order to solve the problem of low performance of some electrolytic chambers of a PEM electrolyzer and avoid the problem of PEM electrolyzer relaxation and normal electrolytic chamber failure caused by dismantling the stack for maintenance, the present invention provides a PEM electrolyzer fault handling method based on plate short-circuiting. The method short-circuits the metal plates on both sides of the faulty electrolytic chamber so that the current does not pass through the electrolytic chamber, actively shuts down the reaction capacity of the electrolytic chamber, and transforms the risk of high operating voltage of the electrolytic chamber.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A method for handling a PEM electrolyzer fault based on a short-circuited plate comprises the following steps:

[0008] S1. Modeling of PEM electrolyzer plates;

[0009] S2. Evaluate the assembly status of the PEM electrolyzer and confirm the plate area, area and spacing that can be short-circuited;

[0010] S3. Select the short-circuit material;

[0011] S4. Confirm the electrothermal coupling simulation boundary conditions according to the PEM electrolyzer operating conditions and the electrothermal characteristics of the short-circuit material selected in S3;

[0012] S5. Based on the plate model established in S1, the electric and thermal coupling simulation method is used to simulate the electric field and thermal field distribution under working conditions after the plate is short-circuited, to form a short-circuit area and material solution set with no overheating area and uniform electric field distribution, and to select the best short-circuit solution according to the difficulty of implementation;

[0013] S6. Locate the faulty electrolysis chamber and clean the faulty area;

[0014] S7. Use the best short-circuit solution selected in S5 to connect the short-circuit areas of the plates on both sides of the faulty electrolysis chamber;

[0015] S8. After the short circuit is completed, clean the connection area with a detergent and reinstall and operate the PEM electrolyzer to ensure that the fault has been resolved.

[0016] Furthermore, in step S1, the PEM electrolyzer plate is modeled, that is, the plate geometric dimensions, flow field configuration, flow channel period, and sealing height are modeled using Solidworks, UG, ProE or C4D three-dimensional modeling software.

[0017] As a further preferred embodiment of the present invention, in step S2, the short-circuited plate region, area and spacing can be confirmed by measuring the distance from the outer sealing line of the plate to the exposed edge of the plate, the length of the exposed edge of the plate and the spacing between adjacent plates.

[0018] Specifically, the short-circuited plate area should be outside the sealant line, maintain a safety distance of at least 1mm from the sealant line, and this area should not interfere with the normal functional components of the plate, such as the inspection line. The short-circuited area is the sum of the areas that meet the above requirements. The short-circuited spacing is the spacing between the adjacent plates involved.

[0019] Furthermore, in step S3, the short-circuit material is selected according to the rated working current of the PEM electrolyzer and the material of the electrode plate.

[0020] As a further preferred embodiment of the present invention, in step S6, the position of the faulty electrolytic chamber is the positioning information determined by the single-cell electrolytic chamber voltage data fed back by the voltage patrol meter during operation.

[0021] As a further preferred embodiment of the present invention, in step S6, the specific method of cleaning the fault area includes:

[0022] S601. Cut the membrane electrode frame exposed outside the sealing structure of the faulty electrolysis chamber and clear the objects in the gap between adjacent plates;

[0023] S602. Use alcohol or other cleaning agents to wipe the exposed plate edges to ensure that there is no dust and grease on the plate surface.

[0024] As another preferred embodiment of the present invention, in step S7, the short-circuited areas of the plates on both sides of the faulty electrolysis chamber may be connected by welding, filling with metal sheets, filling with liquid metal or connecting with wires.

[0025] Furthermore, in step S7, the temperature during connection cannot exceed the tolerance temperature of the PEM electrolyzer component in direct contact.

[0026] Furthermore, in step S8, the method for ensuring that the fault has been resolved is: observing the voltage of the inspection instrument by running the PEM electrolyzer, and judging whether the fault has been resolved by the voltage value.

[0027] Preferably, in step S8, the cleaning agent is alcohol, methanol, isopropanol or water.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The PEM electrolyzer fault handling method based on plate short-circuiting provided by the present invention short-circuits the plates on both sides of the abnormal electrolytic chamber on the faulty PEM electrolyzer, actively shuts down the reaction capacity of the electrolytic chamber, effectively handles the problem of low performance of some electrolytic chambers of the PEM electrolyzer, and reduces the safety risk of the operation of the PEM electrolyzer.

[0030] 2. The sealing of the PEM electrolyzer is not affected, and the other electrolytic chambers can work normally, avoiding the problem of PEM electrolyzer looseness and normal electrolytic chamber failure caused by dismantling the stack for maintenance, and increasing the service life of the electrolyzer.

[0031] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other design solutions and drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 Schematic diagram of the short-circuit structure of a PEM electrolyzer.

[0034] Figure 2 Schematic diagram of the short-circuit area of ​​the PEM electrolyzer plates.

[0035] Figure 3 This is a comparison chart of the membrane electrode voltage before and after the PEM electrolyzer is short-circuited (short-circuited in Section 2).

[0036] Figure 4 Schematic diagram of another type of PEM electrolyzer plate short-circuit area.

[0037] Description of reference numerals:

[0038] 1-metal bipolar plate; 2-anode gas diffusion layer; 3-anode catalyst layer; 4-proton exchange membrane; 5-cathode catalyst layer; 6-cathode gas diffusion layer; 7-anode cavity opening; 8-cathode cavity opening; 9-sealing glue line; 10-flow channel; 11-short-circuit area.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0040] The content of the present invention can be further understood by combining the following detailed description of the preferred implementation method of the present invention and the embodiments included. Unless otherwise stated, all technical and scientific terms used in this article have the same meaning as those of ordinary skill in the art to which the present invention belongs. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in the present invention, the definition of the term provided in the present invention shall prevail.

[0041] In a typical implementation of this application, please refer to Figure 1 A method for troubleshooting a PEM electrolyzer based on short-circuiting of polar plates comprises the following steps:

[0042] S1. Modeling of PEM electrolyzer plates;

[0043] S2. Evaluate the assembly status of the PEM electrolyzer and confirm the plate area, area and spacing that can be short-circuited;

[0044] S3. Select the short-circuit material;

[0045] S4. Confirm the electrothermal coupling simulation boundary conditions according to the PEM electrolyzer operating conditions and the electrothermal characteristics of the short-circuit material selected in S3;

[0046] S5. Based on the plate model established in S1, the electric and thermal coupling simulation method is used to simulate the electric field and thermal field distribution under working conditions after the plate is short-circuited, to form a short-circuit area and material solution set with no overheating area and uniform electric field distribution, and to select the best short-circuit solution according to the difficulty of implementation;

[0047] S6. Locate the faulty electrolysis chamber and clean the faulty area;

[0048] S7. Use the best short-circuit solution selected in S5 to connect the short-circuit areas of the plates on both sides of the faulty electrolysis chamber;

[0049] S8. After the short circuit is completed, clean the connection area with a detergent and reinstall and operate the PEM electrolyzer to ensure that the fault has been resolved.

[0050] As a further preferred embodiment of the present invention, in step S1, the PEM electrolyzer plate can be modeled by preferably using Solidworks, UG, ProE, C4D three-dimensional modeling software to model the plate geometric dimensions, flow field configuration, flow channel period, and sealing height for subsequent electrothermal coupling finite element simulation to evaluate the feasibility of the short-circuiting scheme.

[0051] As a further illustration of the technical solution of the present invention, in step S2, the short-circuited plate region, area and spacing can be confirmed by measuring the distance from the outer sealing glue line of the plate to the exposed edge of the plate, the length of the exposed edge of the plate and the spacing between adjacent plates. In specific implementation, the short-circuited plate area should be outside the sealing glue line, maintain a safety distance of at least 1mm from the sealing glue line, and the area should not interfere with the normal functional components of the plate such as the inspection line. The short-circuited area is the sum of the areas that meet the above requirements. The short-circuited spacing is the spacing between the adjacent plates involved.

[0052] In step S3, the short-circuit material is selected according to the rated working current of the PEM electrolyzer and the material of the electrode plate. It should be noted that the short-circuit material should have high electrical conductivity and thermal conductivity to have sufficient safe current carrying capacity without causing damage to the electrode plate.

[0053] In a specific embodiment, the rated working current of the PEM electrolyzer is 500A, and the plate material is titanium alloy. The short-circuit current is relatively large. Considering the electrical and thermal conductivity of titanium alloy, the short-circuit area should be as large as possible to avoid overheating. 2 In this case, the short-circuit material should have high electrical conductivity and high thermal conductivity, and the contact resistance with the plate should be as low as possible to avoid overheating in the short-circuit area. Taking into account the compatibility of the short-circuit material and the plate material, the short-circuit material can be selected from metals and alloys such as copper, tin, and silver.

[0054] As a further preferred embodiment of the present invention, in step S6, the position of the faulty electrolytic chamber is the positioning information determined by the single-cell electrolytic chamber voltage data fed back by the voltage patrol meter during the working process.

[0055] As a further preferred embodiment of the present invention, in step S6, the specific method of cleaning the fault area includes:

[0056] S601. Cut the membrane electrode frame exposed outside the sealing structure of the faulty electrolysis chamber and clear the objects in the gap between adjacent plates;

[0057] S602. Use alcohol or other cleaning agents to wipe the exposed plate edges to ensure that there is no dust and grease on the plate surface.

[0058] It is worth mentioning that in step S7, the short-circuited areas of the plates on both sides of the faulty electrolytic chamber can be connected by welding, filling metal sheets, filling liquid metal or connecting wires, etc. It should be noted that the connection temperature cannot exceed the tolerance temperature of the PEM electrolyzer components in direct contact.

[0059] In specific implementation, in step S8, the method for ensuring that the fault has been resolved is: observing the voltage of the inspection instrument by running the PEM electrolyzer, and judging whether the fault has been resolved by the voltage value.

[0060] In step S8, the cleaning agent is preferably alcohol, methanol, isopropanol or water.

[0061] The present invention short-circuits the polar plates on both sides of the abnormal electrolytic chamber on the faulty PEM electrolytic cell, actively shuts down the reaction capacity of the electrolytic chamber, effectively handles the problem of low performance of some electrolytic chambers of the PEM electrolytic cell, and reduces the safety risk of the operation of the PEM electrolytic cell.

[0062] In a typical embodiment, see Figure 1 , Figure 1The figure is a schematic diagram of the short-circuit structure of a PEM electrolyzer. The PEM cell is composed of a plurality of stacked electrolytic chambers. A single electrolytic chamber includes two adjacent metal bipolar plates 1 and anode gas diffusion layer 2, anode catalyst layer 3, proton exchange membrane 4, cathode catalyst layer 5, and cathode gas diffusion layer 6 components stacked in sequence therebetween. During the implementation process, the short-circuit material is filled between the two adjacent metal bipolar plates 1 to short-circuit the two adjacent metal bipolar plates and actively shut down the reaction capacity of the electrolytic chamber. Due to the barrier effect of the sealant line 9 on the metal bipolar plate 1, the short-circuit material will not affect the anode gas diffusion layer 2, anode catalyst layer 3, proton exchange membrane 4, cathode catalyst layer 5, and cathode gas diffusion layer 6 components between the plates.

[0063] In another specific embodiment, see Figure 2 and Figure 3 , Figure 2 Schematic diagram of the short-circuit area of ​​the PEM electrolyzer plate, wherein the anode cavity 7, the cathode cavity 8, the sealant line 9, the flow channel 10 and the short-circuit area 11 are respectively shown in the figure. This embodiment relates to a PEM electrolyzer fault handling method based on plate short-circuit, which specifically includes the following steps:

[0064] 1. Use Solidworks 3D modeling software to model the plate geometry, flow field configuration, flow channel cycle, and sealing height;

[0065] 2. Evaluate the assembly status of the PEM electrolyzer by measuring the distance from the outer sealant line of the plate to the exposed edge of the plate, the length of the exposed edge of the plate, and the distance between adjacent plates to confirm the 3 mm area on both sides of the long side of the plate (see Figure 2 ) can be short-circuited, the short-circuit area is up to 1800 mm 2 , the distance between the two plates is 2 mm;

[0066] 3. It is planned to use Sn63 / Pb37 (melting point 183°C) with a diameter of 0.38 mm or Sn42 / Bi58 (melting point 138°C) with a diameter of 0.8 mm for welding;

[0067] 4. Set the cooling water flow rate in the flow channel to 2 mL / cm 2 , temperature is 60℃, current density is 1 A / cm 2 , as well as the dimensions and electrothermal characteristics of the plates and welding blocks;

[0068] 5. Based on the established plate model, the electric and thermal coupling simulation is used to simulate the electric and thermal field distribution under working conditions after the plate is short-circuited. The conclusion is that when the width of the short-circuit area is more than 1 mm, the maximum temperature of the short-circuit area does not exceed 70°C, and the electric field distribution is uniform in the service temperature range of each component material. According to the plate spacing and the melting point of the tin solder wire, a 0.8mm diameter Sn42 / Bi58 (melting point 138°C) tin solder wire is selected for welding;

[0069] 6. Locate the faulty electrolysis chamber at Section 2, and cut the membrane electrode frame exposed outside the sealing structure of the faulty electrolysis chamber with a cutting width of 2-3 mm;

[0070] 7. Use alcohol or other cleaning agents to wipe the exposed edge of the plate to ensure that there is no dust and grease on the surface of the plate;

[0071] 8. Set the soldering iron temperature to 200°C, melt the Sn42 / Bi58 solder wire, and fill the gap between the metal plates on both sides of the faulty electrolytic chamber.

[0072] 9. After the short circuit is completed, clean the connection area with alcohol or other cleaning agents. Reinstall and operate the PEM electrolyzer to obtain the voltage of each electrolytic cell of the PEM electrolyzer (see Figure 3 ), confirm that the fault has been resolved.

[0073] In yet another specific embodiment, see Figure 4 , Figure 4 Another schematic diagram of the short-circuit area of ​​the plate of a PEM electrolyzer is shown in the figure, wherein the anode cavity 7, the cathode cavity 8, the sealant line 9, the flow channel 10 and the short-circuit area 11 are respectively shown in the figure. The fault handling method of the PEM electrolyzer based on the short-circuit of the plate involved in this embodiment specifically includes the following steps:

[0074] 1. Use Solidworks, UG, ProE or C4D 3D modeling software to model the plate geometry, flow field configuration, flow channel cycle and sealing height;

[0075] 2. Evaluate the assembly status of the PEM electrolyzer by measuring the distance from the outer sealant line of the plate to the exposed edge of the plate, the length of the exposed edge of the plate, and the distance between adjacent plates to confirm the 3 mm area on both sides of the long and short sides of the plate (see Figure 4 ) can be short-circuited, the short-circuit area is up to 3000 mm 2 , the distance between the two plates is 2 mm;

[0076] 3. It is planned to use molten Sn42 / Bi58 (melting point 138℃) solder paste or tin-indium alloy (melting point 117℃) to coat the surface of 2 mm copper plate and insert it into the gap between the plates to form a short circuit;

[0077] 4. Set the cooling water flow rate in the flow channel to 2 mL / cm 2 , temperature is 60℃, current density is 1 A / cm 2 , as well as the dimensions and electrothermal characteristics of the plates and copper plates;

[0078] 5. Based on the established plate model, the electric and thermal coupling simulation is used to simulate the electric field and thermal field distribution under working conditions after the plate is short-circuited. The conclusion is: when the width of the short-circuit area is more than 0.8 mm, the maximum temperature of the short-circuit area does not exceed 70°C, and the electric field distribution is uniform in the service temperature range of each component material. According to the melting point of the alloy, tin-indium alloy (melting point 117°C) and 2 mm copper plate are selected for short-circuiting;

[0079] 6. Locate the faulty electrolysis chamber at Section 6, and cut the membrane electrode frame exposed outside the sealing structure of the faulty electrolysis chamber with a cutting width of 2-3 mm;

[0080] 7. Use alcohol or other cleaning agents to wipe the exposed edge of the plate to ensure that there is no dust and grease on the surface of the plate;

[0081] 8. Set the soldering iron temperature to 200°C, melt the tin-indium alloy and apply it on the surface of the copper plate, and insert it into the gap between the plates.

[0082] 9. After the short circuit is completed, clean the connection area with alcohol or other cleaning agents, reinstall and operate the PEM electrolyzer, and confirm that the fault has been resolved.

[0083] By adopting the PEM electrolyzer fault handling method based on plate short-circuiting of the present invention, the sealing of the PEM electrolyzer is not affected, and the remaining electrolytic chambers can work normally, thereby avoiding the problems of PEM electrolyzer relaxation and normal electrolytic chamber failure caused by dismantling the stack for maintenance, and improving the service life of the electrolyzer.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for handling a PEM electrolyzer fault based on plate short circuit, characterized in that: The following steps are involved: S1. Modeling of PEM electrolyzer plates; S2. Evaluate the assembly status of the PEM electrolyzer to confirm the region, area and spacing of the plates that can be short-circuited; the region, area and spacing of the plates that can be short-circuited can be confirmed by measuring the distance from the outer sealant line of the plate to the exposed edge of the plate, the length of the exposed edge of the plate and the spacing between adjacent plates; the short-circuited plate region should be outside the sealant line and maintain a safety distance of at least 1 mm from the sealant line, and the region should not interfere with the normal functional components of the plate; S3. Select the short-circuit material, which can be selected according to the rated current of the PEM electrolyzer and the plate material; S4. Confirm the electrothermal coupling simulation boundary conditions according to the PEM electrolyzer operating conditions and the electrothermal characteristics of the short-circuit material selected in S3; S5. Based on the plate model established in S1, the electric and thermal coupling simulation method is used to simulate the electric field and thermal field distribution under working conditions after the plate is short-circuited, to form a set of short-circuit areas and materials with no overheating area and uniform electric field distribution, and to select the best short-circuit solution according to the difficulty of implementing each solution; S6. Locate the faulty electrolytic chamber and clean the faulty area; the location of the faulty electrolytic chamber is determined by the voltage data of the single-section electrolytic chamber feedback from the voltage patrol meter during operation; S7. Use the best short-circuit solution selected in S5 to connect the short-circuit areas of the plates on both sides of the faulty electrolysis chamber; S8. After the short circuit is completed, clean the connection area with a detergent and reinstall and operate the PEM electrolyzer to ensure that the fault has been resolved.

2. The method for handling a PEM electrolyzer fault based on a short-circuited plate according to claim 1, characterized in that: Step S1, modeling the PEM electrolyzer plate, that is, using Solidworks, UG, ProE or C4D three-dimensional modeling software to model the plate geometry, flow field configuration, flow channel period, and sealing height.

3. The method for handling a PEM electrolyzer fault based on plate short circuit according to claim 1, characterized in that: In step S6, the specific method of cleaning the fault area includes: S601. Cut the membrane electrode frame exposed outside the sealing structure of the faulty electrolysis chamber and clear the objects in the gap between adjacent plates; S602. Use a cleaning agent to wipe the exposed edge of the plate to ensure that there is no dust and grease on the surface of the plate.

4. The method for handling a PEM electrolyzer fault based on a short-circuited plate according to claim 1, characterized in that: In step S7, the short-circuited areas of the plates on both sides of the faulty electrolysis chamber may be connected by welding, filling with metal sheets, filling with liquid metal or connecting with wires.

5. The method for handling a PEM electrolyzer fault based on a short-circuited plate according to claim 1, characterized in that: In step S7, the temperature during connection cannot exceed the tolerance temperature of the PEM electrolyzer components in direct contact.

6. The method for handling a PEM electrolyzer fault based on plate short circuit according to claim 1, characterized in that: In step S8, the method for ensuring that the fault has been resolved is: observing the voltage of the inspection instrument by running the PEM electrolyzer, and judging whether the fault has been resolved by the voltage value.

7. The method for handling a PEM electrolyzer fault based on a short-circuited plate according to claim 1, characterized in that: In step S8, the cleaning agent is alcohol, methanol, isopropanol or water.

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