JP5462551B2 - Seal inspection method for high pressure water electrolyzer - Google Patents

Description

  In the present invention, an anode-side power feeder and a cathode-side power feeder are provided on both sides of the electrolyte membrane, and a first flow path for supplying water is formed between the anode-side power feeder and one separator, In the high pressure water electrolysis apparatus in which the water is electrolyzed and a second flow path for obtaining hydrogen higher than the pressure of the water is formed between the cathode-side power feeder and the other separator. The present invention relates to a seal inspection method for a high-pressure water electrolysis apparatus that inspects a seal function of a seal member that holds the seal.

  In general, a water electrolysis apparatus is employed to produce hydrogen. This water electrolysis apparatus uses a solid polymer electrolyte membrane (ion exchange membrane) in order to decompose water and generate hydrogen (and oxygen). Electrode catalyst layers are provided on both sides of the solid polymer electrolyte membrane to form an electrolyte membrane / electrode structure, and a power feeder is provided on both sides of the electrolyte membrane / electrode structure. It is configured.

  Therefore, in a state where a plurality of units are stacked, a voltage is applied to both ends in the stacking direction, and water is supplied to the anode-side power feeder. For this reason, water is decomposed and hydrogen ions (protons) are generated on the anode side of the electrolyte membrane / electrode structure, and the hydrogen ions permeate the solid polymer electrolyte membrane and move to the cathode side to bond with electrons. Thus, hydrogen is produced. On the other hand, on the anode side, oxygen produced together with hydrogen is discharged from the unit with excess water.

  In this type of equipment, a high-pressure hydrogen production apparatus capable of generating high-pressure hydrogen on the cathode side is known. For example, in Patent Document 1, as shown in FIG. 6, a fastening device 4 for fastening a laminated body of the anode main electrode 1, the plurality of unit cells 2, and the cathode main electrode 3 in the stacking direction is provided. The clamping device 4 includes a cylinder 6 having an introduction nozzle 5a and a discharge nozzle 5b for compression fluid, and a piston 8 disposed in the cylinder 6 with an O-ring 7 interposed.

  The clamping device 4 applies a pressure always higher than the hydrogen pressure generated during operation of the water electrolyzer by a fixed clamping pressure by the piston 8. That is, a constant tightening pressure is always ensured by adjusting an adjustment valve (not shown) connected to the introduction nozzle 5a and the discharge nozzle 5b for the compression fluid.

Japanese Patent Laid-Open No. 2003-160891

  However, in Patent Document 1 described above, when the operation of the water electrolyzer is stopped, the tightening load by the tightening device 4 is reduced, so that the pressure in the cylinder 6 is frequently switched between high pressure and low pressure. ing. Therefore, when the inside of the cylinder 6 is maintained at a high pressure, there is a possibility that high-pressure gas molecules that are a compression fluid may enter the O-ring 7.

  For this reason, when the internal pressure of the cylinder 6 is suddenly reduced, the high-pressure gas held inside the O-ring 7 is released while rapidly expanding, so that minute bubbles are likely to be generated inside the O-ring 7. . As a result, the O-ring 7 is easily damaged, and the sealing function of the O-ring 7 is deteriorated. On the other hand, a defect of the O-ring 7 cannot be easily detected.

  The present invention solves this type of problem and provides a seal inspection method for a high-pressure water electrolysis apparatus capable of easily and reliably inspecting the sealing function of a seal member holding high-pressure hydrogen by a simple process. The purpose is to do.

In the present invention, an anode-side power feeder and a cathode-side power feeder are provided on both sides of the electrolyte membrane, and a first flow path for supplying water is formed between the anode-side power feeder and one separator, In the high-pressure water electrolysis apparatus, a second flow path is formed between the cathode-side power feeder and the other separator, in which the water is electrolyzed to obtain hydrogen having a pressure higher than the pressure of the water. The present invention relates to a seal inspection method for a high-pressure water electrolysis apparatus that inspects a sealing function of a sealing member that holds the high-pressure hydrogen inside .

In this seal inspection method, high-pressure hydrogen is supplied to a first chamber that communicates with the second flow path and is sealed by a seal member, while the other side is opposite to the first chamber across the seal member. A step of detecting the pressure in the closed second chamber formed by another sealing member which is a member of the first member, and the pressure in the second chamber is detected while the pressure in the first chamber is reduced. And a step of judging whether the sealing function of the seal member is good or not based on a pressure reduction state in the second chamber.

  Further, in this seal inspection method, the pressure decrease state in the second chamber is compared with a preset specified pressure decrease state or compared with the pressure decrease state in the first chamber, and the seal is determined based on the comparison result. It is preferable to judge the quality of the sealing function of the member.

  Furthermore, in this seal inspection method, it is preferable that the pressure in the first chamber and the pressure in the second chamber are the same before the first chamber is depressurized.

  Further, in this seal inspection method, the first chamber is a cylinder chamber into which high-pressure hydrogen is introduced, and the seal member advances and retreats in the cylinder chamber in the axial direction and presses the other separator toward the cathode side power supply side. It is preferable that the piston is arranged at a sliding portion between the possible piston and the inner wall of the cylinder chamber.

  According to the present invention, when high-pressure hydrogen is supplied into the first chamber, the hydrogen having a small molecular diameter enters the inside of the seal member and is introduced into the second chamber. For this reason, the pressure in the second chamber becomes high, and the pressure in the second chamber is detected. Next, when the pressure in the first chamber is reduced, the high-pressure hydrogen in the second chamber passes through the seal member and moves into the first chamber, and the pressure in the second chamber is reduced.

  At this time, the quality of the sealing function of the sealing member is determined based on the pressure reduction rate and angle in the second chamber. Therefore, before the seal function of the seal member is lost, it is possible to reliably detect the replacement time of the seal member, and to prevent hydrogen leakage as much as possible.

It is a partial cross section side view of the water electrolysis apparatus to which the seal inspection method concerning a 1st embodiment of the present invention is applied. It is principal part sectional explanatory drawing of the said water electrolysis apparatus. It is a flowchart for implementing the said seal | sticker inspection method. It is change explanatory drawing of the internal pressure of a cylinder chamber, and the internal pressure of a chamber. It is principal part sectional explanatory drawing of the water electrolysis apparatus to which the seal | sticker test | inspection method concerning the 2nd Embodiment of this invention is applied. It is explanatory drawing of the water electrolysis tank currently disclosed by patent document 1. FIG.

  As shown in FIG. 1, the water electrolysis apparatus 10 to which the seal inspection method according to the first embodiment of the present invention is applied constitutes a differential pressure type high-pressure hydrogen production apparatus. The water electrolysis apparatus 10 includes a laminate 14 in which a plurality of unit cells 12 are laminated in a vertical direction (arrow A direction) or a horizontal direction (arrow B direction).

  At one end in the stacking direction of the stacked body 14, a terminal plate 16a, an insulating plate 18a, and an end plate 20a are sequentially disposed. Similarly, a terminal plate 16b, an insulating plate 18b, and an end plate 20b are sequentially disposed at the other end of the stacked body 14 in the stacking direction.

  In the water electrolysis apparatus 10, for example, the disk-shaped end plates 20a and 20b are integrally clamped and held via a plurality of tie rods 22 extending in the arrow A direction. The water electrolysis apparatus 10 may employ a configuration in which the water electrolysis apparatus 10 is integrally held by a box-like casing (not shown) including the end plates 20a and 20b as end plates. Moreover, although the water electrolysis apparatus 10 has a substantially cylindrical shape as a whole, it can be set in various shapes such as a cubic shape.

  Terminal portions 24a and 24b are provided on the side portions of the terminal plates 16a and 16b so as to protrude outward. The terminal portions 24a and 24b are electrically connected to the power source 28 via the wirings 26a and 26b. The terminal portion 24 b on the anode (anode) side is connected to the positive pole of the power source 28, while the terminal portion 24 a on the cathode (cathode) side is connected to the negative pole of the power source 28.

  The unit cell 12 includes a disk-shaped electrolyte membrane / electrode structure 32, and an anode side separator 34 and a cathode side separator 36 that sandwich the electrolyte membrane / electrode structure 32.

  The anode-side separator 34 and the cathode-side separator 36 have a disk shape, and are made of, for example, a carbon member or the like, or are used for corrosion protection on a steel plate, a stainless steel plate, a titanium plate, an aluminum plate, a plated steel plate, or a metal surface thereof. The metal plate that has been subjected to the above surface treatment is press-molded or cut and subjected to a corrosion-resistant surface treatment.

  The electrolyte membrane / electrode structure 32 includes, for example, a solid polymer electrolyte membrane 38 in which a perfluorosulfonic acid thin film is impregnated with water, and an anode-side power feeder 40 disposed on both sides of the solid polymer electrolyte membrane 38. And a cathode-side power feeder 42.

  An anode electrode catalyst layer 40a and a cathode electrode catalyst layer 42a are formed on both surfaces of the solid polymer electrolyte membrane 38. The anode electrode catalyst layer 40a uses, for example, a Ru (ruthenium) -based catalyst, while the cathode electrode catalyst layer 42a uses, for example, a platinum catalyst.

  The anode-side power supply body 40 and the cathode-side power supply body 42 are made of, for example, a sintered body (porous conductor) of spherical atomized titanium powder. The anode-side power supply body 40 and the cathode-side power supply body 42 are provided with smooth surface portions that are etched after the grinding process. Note that the anode-side power supply body 40 and the cathode-side power supply body 42 may be formed with openings in a metal sheet such as a corrosion-resistant titanium sheet by etching, drilling, electric discharge machining, electron beam, laser, pressing, or the like.

  A first flow path 44 is provided on the surface of the anode separator 34 facing the electrolyte membrane / electrode structure 32, and a second flow path is provided on the surface of the cathode separator 36 facing the electrolyte membrane / electrode structure 32. A path 46 is provided. The first flow path 44 and the second flow path 46 are provided within a range corresponding to the surface areas of the anode-side power supply body 40 and the cathode-side power supply body 42, and are configured by a plurality of flow path grooves, a plurality of embosses, and the like. .

  A water supply passage 48 for supplying water (pure water) and an oxygen discharge passage 50 for discharging oxygen generated by the reaction and used water communicate with the first flow path 44. The second flow path 46 is provided with a hydrogen discharge passage 52 for discharging hydrogen generated by the reaction (high pressure hydrogen). The hydrogen discharge passage 52 communicates with a hydrogen communication hole 54 for allowing hydrogen to flow in the direction of arrow A, which is the stacking direction.

  A piston member 56 is disposed between the insulating plate 18a and the end plate 20a so as to freely advance and retract. As shown in FIG. 2, the piston member 56 includes a piston 60 bulging from the flange portion 58 in the direction of arrow A, and the piston 60 is a cylinder chamber (first chamber) formed in the inner peripheral portion of the end plate 20a. 1 chamber) 62. An elastic body such as a disc spring 64 is interposed between the inner wall surface 62 a of the cylinder chamber 62 and the tip of the piston 60.

  A first circumferential groove 66a and a second circumferential groove 66b are formed on the outer circumferential surface 60a of the piston 60 so as to be separated from each other by a predetermined interval in the axial direction. For example, a first seal member 68a that is an O-ring is disposed in the first circumferential groove 66a, and a second seal member (another seal member) that is an O-ring is disposed in the second circumferential groove 66b, for example. 68b is disposed.

  A gap is formed between the outer peripheral surface 60a of the piston 60 and the inner wall surface 62a of the cylinder chamber 62, and a chamber (second chamber) is formed between the first seal member 68a and the second seal member 68b. 70 is formed. A pressure detection sensor 72 is disposed on the end plate 20 a corresponding to the chamber 70.

  The piston member 56 is formed with a high-pressure hydrogen passage 74 having one end communicating with the hydrogen communication hole 54. The other end of the high-pressure hydrogen passage 74 is opened to the cylinder chamber 62, and a high-pressure hydrogen outlet port 76 formed in the end plate 20a communicates with the cylinder chamber 62.

  The operation of the water electrolysis apparatus 10 configured as described above will be described below.

  As shown in FIG. 1, water is supplied to the water supply passage 48 of each unit cell 12 constituting the water electrolysis apparatus 10 and is electrically connected to the terminal portions 24a and 24b of the terminal plates 16a and 16b. A voltage is applied via the power supply 28. Therefore, in each unit cell 12, water is supplied from the water supply passage 48 to the first flow path 44 of the anode side separator 34, and this water moves along the anode side power supply body 40.

  Accordingly, water is decomposed by electricity in the anode electrode catalyst layer 40a, and hydrogen ions, electrons, and oxygen are generated. Hydrogen ions generated by this anodic reaction permeate the solid polymer electrolyte membrane 38 and move to the cathode electrode catalyst layer 42a side, and combine with electrons to obtain hydrogen.

  For this reason, hydrogen flows along the second flow path 46 formed between the cathode side separator 36 and the cathode side power supply body 42. This hydrogen is maintained at a higher pressure than the water supply passage 48, and can flow out from the hydrogen discharge passage 52 through the hydrogen communication hole 54 and be taken out of the water electrolysis apparatus 10.

  As shown in FIG. 2, the high-pressure hydrogen led out to the hydrogen communication hole 54 is introduced into the cylinder chamber 62 through the high-pressure hydrogen passage 74 of the piston member 56. Therefore, the piston member 56 presses the cathode separator 36 toward the electrolyte membrane / electrode structure 32 through the pressure of the high-pressure hydrogen introduced into the cylinder chamber 62 and the elastic force of the disc spring 64. Therefore, the gap generated between the solid polymer electrolyte membrane 38 and the cathode-side power feeder 42 can be reduced, and the electrolytic voltage can be effectively reduced by preventing the electrolytic voltage from rising.

  On the other hand, as shown in FIG. 1, oxygen generated by the reaction and used water flow through the first flow path 44. The mixed fluid of oxygen and water is discharged outside the water electrolysis device 10 along the oxygen discharge passage 50. The second channel 46 has a higher pressure than the first channel 44.

  Next, the seal inspection method according to the first embodiment will be described below along the flowchart shown in FIG.

  First, when the operation of the water electrolysis apparatus 10 is started (YES in step S1), the process proceeds to step S2, and the pressure in the chamber 70 is detected via the pressure detection sensor 72.

  Here, when the operation of the water electrolysis apparatus 10 is started, as described above, hydrogen is generated in the second flow path 46, and the second flow path 46, the hydrogen communication hole 54, the high-pressure hydrogen passage 74, and the cylinder chamber. The 62 hydrogen pressure increases.

  When the internal pressure of the cylinder chamber 62 becomes high, hydrogen gas permeates and is held inside the first seal member 68a. When the high pressure state in the cylinder chamber 62 continues for a long time, hydrogen gas passes through the first seal member 68a and fills the chamber 70. Accordingly, the internal pressure of the chamber 70 gradually shifts to a high pressure state and is maintained at the same pressure as the internal pressure of the cylinder chamber 62 (see FIG. 4).

  Next, when the operation of the water electrolysis apparatus 10 is stopped (YES in step S3), the process proceeds to step S4, and the depressurization process in the water electrolysis apparatus 10 is performed. In this depressurization process, the second flow path 46 is rapidly decompressed to the same pressure as the first flow path 44, that is, to atmospheric pressure (see FIG. 4).

  At that time, if the first sealing member 68a has a normal sealing function, the pressure decreasing rate of the chamber 70 becomes very gradual (refer to normal in FIG. 4). On the other hand, when bubbles (blisters) are generated inside the first seal member 68a and the sealing function of the first seal member 68a is deteriorated, the pressure decreasing speed of the chamber 70 is increased, and the pressure of the cylinder chamber 62 is decreased. It approximates the speed (see NG in FIG. 4).

  For this reason, the pressure decrease state of the chamber 70 at the normal time is detected in advance, and this is set to the specified pressure decrease state. Then, the pressure decrease state of the chamber 70 detected by the pressure detection sensor 72 is compared with the specified pressure decrease state (step S5). Based on the comparison result, the quality of the sealing function of the first sealing member 68a is determined (step S6).

  If it is determined that the first seal member 68a has a desired seal function (YES in step S6), the seal inspection process for the first seal member 68a is completed. On the other hand, if it is determined that the first seal member 68a does not have the desired seal function (NO in step S6), the process proceeds to step S7, where the first seal member 68a is NG, and the replacement timing is reached. It is judged that it has reached.

  Although the second seal member 68b retains hydrogen gas therein, the hydrogen gas inside the second seal member 68b gradually escapes when the cylinder chamber 62 is depressurized. For this reason, it is possible to prevent foaming from being caused inside the second seal member 68b. As a result, the second seal member 68b does not lose its sealing function before the first seal member 68a, and reliably prevents hydrogen gas from leaking outside, so that the maintenance time of the first seal member 68a can be reduced. Can be detected.

  In this case, when high-pressure hydrogen gas is generated in the second flow path 46 during operation of the water electrolysis apparatus 10, the hydrogen gas having a small molecule enters the inside of the first seal member 68 a from the cylinder chamber 62. Since hydrogen gas is further introduced into the chamber 70, the pressure in the chamber 70 becomes high.

  Therefore, in the first embodiment, the internal pressure of the chamber 70 is detected by the pressure detection sensor 72, and the pressure decreasing state of the chamber 70 is detected during the decompression process accompanying the stop of the operation of the water electrolysis apparatus 10. And the quality of the sealing function of the 1st seal member 68a is judged based on the detection result. Therefore, it is possible to reliably detect the replacement time of the first seal member 68a before the sealing function of the first seal member 68a is lost, and to prevent hydrogen leakage as much as possible. An effect is obtained.

  FIG. 5 is a cross-sectional explanatory view of a main part of a water electrolysis apparatus 80 to which the seal inspection method according to the second embodiment of the present invention is applied. In addition, the same referential mark is attached | subjected to the component same as the water electrolysis apparatus 10 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted.

  The water electrolysis device 80 includes a pressure detection sensor 82 for detecting the internal pressure of the cylinder chamber 62 in addition to the pressure detection sensor 72 for detecting the internal pressure of the chamber 70. In addition to the cylinder chamber 62, the pressure detection sensor 82 can be arbitrarily attached to a part capable of detecting the pressure of the high-pressure hydrogen generated in the second flow path 46, such as the high-pressure hydrogen passage 74 and the hydrogen communication hole 54, for example. It is.

  In the second embodiment, the seal inspection of the first seal member 68a is performed according to the flowchart shown in FIG. 3 similarly to the first embodiment. At this time, in step S5, the internal pressure of the cylinder chamber 62 is detected by the pressure detection sensor 82 while the internal pressure of the chamber 70 is detected by the pressure detection sensor 72 during the decompression process of the cylinder chamber 62.

  Furthermore, as shown in FIG. 4, the pressure reduction state of the cylinder chamber 62 at the time of depressurization is compared with the pressure reduction state of the chamber 70. For example, the quality of the sealing function of the first seal member 68a is determined based on whether or not the differential pressure between the pressure in the cylinder chamber 62 and the pressure in the chamber 70 is greater than or equal to a set value.

  Specifically, if the pressure difference between the pressure in the cylinder chamber 62 and the pressure in the chamber 70 is equal to or greater than a set value, it is determined that the first seal member 68a has a desired sealing function. On the other hand, if the differential pressure is less than the set value, it is determined that the first sealing member 68a does not have a desired sealing function. Thereby, in 2nd Embodiment, the effect similar to said 1st Embodiment is acquired.

  In the first and second embodiments, the chamber 70 is formed between the first seal member 68a and the second seal member 68b. However, the present invention is not limited to this. For example, if a second sealed chamber corresponding to the chamber 70 is formed by employing another seal structure instead of the second seal member 68b, the same seal inspection method can be implemented.

  Further, the quality of the sealing function of the first seal member 68a is determined based on the pressure decrease rate of the chamber 70, but the quality of the sealing function of the first seal member 68a is determined based on the pressure reduction angle or the like. Good.

DESCRIPTION OF SYMBOLS 10, 80 ... Water electrolysis apparatus 12 ... Unit cell 14 ... Laminated body 16a, 16b ... Terminal plate 18a, 18b ... Insulation plate 20a, 20b ... End plate 24a, 24b ... Terminal part 28 ... Power supply 32 ... Electrolyte membrane and electrode structure 34 ... anode side separator 36 ... cathode side separator 38 ... solid polymer electrolyte membrane 40 ... anode side power supply body 42 ... cathode side power supply bodies 44, 46 ... flow path 48 ... water supply passage 50 ... oxygen discharge passage 52 ... hydrogen discharge passage 54 ... Hydrogen communication hole 56 ... Piston member 60 ... Piston 62 ... Cylinder chamber 64 ... Belleville spring 68a, 68b ... Seal member 70 ... Chamber 72, 82 ... Pressure detection sensor 74 ... High pressure hydrogen passage 76 ... High pressure hydrogen outlet

Claims (4)

An anode side feeder and a cathode side feeder are provided on both sides of the electrolyte membrane, and a first flow path for supplying water is formed between the anode side feeder and one separator, and the cathode side feeder In the high pressure water electrolysis apparatus in which a second flow path for obtaining hydrogen higher than the pressure of the water is formed by electrolyzing the water between the first separator and the other separator, A method for inspecting a seal of a high-pressure water electrolysis apparatus for inspecting a seal function of a seal member holding hydrogen,
The high-pressure hydrogen is supplied to a first chamber that communicates with the second flow path and is sealed by the seal member, while another member is disposed on the opposite side of the first chamber across the seal member. Detecting the pressure in the closed second chamber formed by some other sealing member;
A step of depressurizing the first chamber and detecting a pressure decrease state in the second chamber;
Determining the quality of the sealing function of the seal member based on the pressure reduction state in the second chamber;
A seal inspection method for a high pressure water electrolysis apparatus, comprising:   2. The seal inspection method according to claim 1, wherein a pressure reduction state in the second chamber is compared with a preset specified pressure reduction state or a pressure reduction state in the first chamber, and the comparison result A seal inspection method for a high-pressure water electrolysis apparatus, wherein the quality of the seal function of the seal member is determined based on the above. 3. The seal inspection method according to claim 1, wherein the pressure in the first chamber and the pressure in the second chamber are the same before the first chamber is depressurized. Seal inspection method for high pressure water electrolysis equipment. The seal inspection method according to any one of claims 1 to 3 , wherein the first chamber is a cylinder chamber into which the high-pressure hydrogen is introduced.
The seal member is disposed at a sliding portion between a piston capable of advancing and retreating in the cylinder chamber in the axial direction and pressing the other separator toward the cathode side power feeding body, and an inner wall of the cylinder chamber. Seal inspection method for high pressure water electrolysis equipment.

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