JP2011149075A - Water electrolysis equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide water electrolysis equipment capable of effectively reducing an area to which pressurizing force of a separator is applied, easily downsizing a pressurizing force-applying device and securing a desired sealing surface pressure. <P>SOLUTION: A unit cell 12 constituting the water electrolysis equipment 10 holds an electrolyte film/electrode structure 32 between an anode side separator 34 and a cathode side separator 36. In the cathode side separator 36, a hollow part 70 closed by a solid polymer electrolyte film 38 is formed on a first separator flat surface part 36aa which is located on the outer side of a first seal groove 68a and faces the solid polymer electrolyte film 38. The flat part other than the hollow part 70 of the first separator flat surface part 36aa and the second separator flat surface part 34aa of the anode side separator 34 constitute a pressure receiving part 72 that receives a load in the lamination direction across the solid polymer electrolyte film 38. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a water electrolysis apparatus in which a power feeding body is provided on both sides of an electrolyte membrane, a separator is stacked on the power feeding body, and a peripheral portion of the electrolyte membrane is sandwiched between a pair of separators.

  In general, a water electrolysis apparatus is employed to produce hydrogen gas that is a fuel gas. This water electrolysis apparatus uses a solid polymer electrolyte 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 feeding body. 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.

  For example, in the water electrolysis apparatus disclosed in Patent Document 1, as shown in FIG. 8, a unit cell configured by arranging power feeders 2 a and 2 b on both surfaces of a membrane electrode assembly 1, an anode chamber 3 a, The separator 4 provided with the cathode chamber 3b is laminated, and the anode side end plate 4a and the cathode side end plate 4b are arranged at both ends.

  The membrane electrode assembly 1 includes an anode catalyst layer 1a and a cathode catalyst layer 1c on both surfaces of a polymer electrolyte membrane 1b, and the polymer electrolyte membrane 1b protrudes to the outside. The pure water introduced into the anode chamber 3a and the cathode chamber 3b generates oxygen gas in the anode chamber 3a by electrolysis and hydrogen gas in the cathode chamber 3b.

  The anode chamber 3a is gas-sealed by an anode side seal packing 6a disposed in a groove 5 formed to face the polymer electrolyte membrane 1b of the membrane electrode assembly 1. The cathode chamber 3b is gas-sealed by a cathode-side seal packing 6b disposed in the packing groove 5 so as to face the polymer electrolyte membrane 1b.

JP 2004-115860 A

  In the above-mentioned Patent Document 1, the pressure of the generated gas is increased and high pressure operation is likely to occur. For this reason, the polymer electrolyte membrane 1b is pressed at a high surface pressure, and in particular, the cathode side end plate 4b has a problem that the portion 7 sealed by the cathode side seal packing 6b is likely to be corroded.

  In addition, in high-pressure operation, the pressure applied in the stacking direction of the unit cells is considerably increased in order to perform high-pressure sealing. At that time, in the separator 4, the anode side end plate 4 a and the cathode side end plate 4 b, the pressing force application area (applied surface pressure area) tends to be large, and the plate thickness increases in order to maintain the pressure strength. is there.

  Moreover, it is necessary to apply a large pressing pressure from the outside to the entire water electrolysis apparatus, and the pressing force applying apparatus is considerably increased in size. As a result, there is a problem that the entire facility cannot be easily made compact and is not economical.

  The present invention solves this type of problem, and can effectively reduce the pressing force application area of the separator, facilitate the downsizing of the pressing force application device, and secure the desired seal surface pressure. It is an object of the present invention to provide a water electrolysis apparatus that can do this.

  In the water electrolysis apparatus according to the present invention, a separator is stacked on a power feeding body provided on both sides of an electrolyte membrane, and a peripheral portion of the electrolyte membrane is sandwiched between a pair of separators. A first seal portion is formed to circulate around the outside of the body to dispose the first seal member, and the second separator is circulated around the outside of the other power supply body on the other separator. A second seal portion for disposing a member is formed, and the first seal portion and the second seal portion are set at different positions with respect to the stacking direction of the separator with the electrolyte membrane interposed therebetween. .

  The at least one separator is formed with a recess closed by the electrolyte membrane in a first separator flat portion located outside the first seal portion and facing the electrolyte membrane, and the first separator The flat portion other than the concave portion of the flat portion and the second separator flat portion facing the first separator flat portion of the other separator constitute a pressure receiving portion that receives a load in the stacking direction across the electrolyte membrane. Yes.

  Further, the water electrolysis apparatus electrolyzes water to generate oxygen and hydrogen having a pressure higher than normal pressure, while the pair of separators has an outer side of a water supply communication hole through which the water flows in the stacking direction. A fourth seal member is arranged around the third seal portion for circulating the third seal member and the outside of the discharge communication hole for circulating the unreacted water and oxygen in the stacking direction. A fourth seal portion for installing and a fifth seal portion for arranging a fifth seal member around the outside of the hydrogen communication hole for circulating the hydrogen in the stacking direction; At least in the first separator plane or the second separator plane, a recess is formed between the first seal portion, the third seal portion, the fourth seal portion, and the fifth seal portion. preferable.

  Further, the power feeding body has a circular shape, and the water supply communication hole and the discharge communication hole are set to have an opening cross-sectional area larger than that of the hydrogen communication hole, and the water supply communication hole and the discharge communication hole Is preferably arranged at a symmetrical position of the separator.

  According to the present invention, the first separator flat portion is formed with the recess closed by the electrolyte membrane, and the flat portion other than the concave portion of the first separator flat portion and the second separator flat portion are: The pressure receiving part which receives the load of a lamination direction is comprised on both sides of a denatured film.

  For this reason, the pressing force application area in the pressure receiving portion can be effectively reduced. Thereby, it is possible to easily reduce the size of the external pressing force application device and to secure a desired seal surface pressure.

It is a perspective explanatory view of a water electrolysis device concerning a 1st embodiment of the present invention. It is a partial cross section side view of the water electrolysis device. It is a disassembled perspective explanatory drawing of the unit cell which comprises the said water electrolysis apparatus. It is front explanatory drawing of the said unit cell. It is the VV sectional view taken on the line of the said unit cell in FIG. It is a section explanatory view of a unit cell which constitutes a water electrolysis device concerning a 2nd embodiment of the present invention. It is a section explanatory view of a unit cell which constitutes a water electrolysis device concerning a 3rd embodiment of the present invention. It is explanatory drawing of the water electrolysis apparatus currently disclosed by patent document 1. FIG.

  As shown in FIG.1 and FIG.2, the water electrolysis apparatus 10 which concerns on the 1st Embodiment of this invention comprises the high voltage | pressure hydrogen production apparatus, and the several unit cell 12 is a perpendicular direction (arrow A direction) or A stacked body 14 is stacked in the 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 upward. Similarly, a terminal plate 16b, an insulating plate 18b, and an end plate 20b are sequentially disposed on the other end in the stacking direction of the stacked body 14 downward.

  The water electrolysis apparatus 10 integrally holds and holds the disc-shaped end plates 20a and 20b via four tie rods 22 extending in the direction of arrow A, for example. 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.

  As shown in FIG. 1, 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 a on the anode (anode) side is connected to the positive pole of the power source 28, while the terminal portion 24 b on the cathode (cathode) side is connected to the negative pole of the power source 28.

  As shown in FIGS. 2 and 3, the unit cell 12 includes a substantially disc-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. Prepare. The anode-side separator 34 and the cathode-side separator 36 have a substantially disk shape and are made of, for example, a carbon member or the like, or a steel plate, a stainless steel plate, a titanium plate, an aluminum plate, a plated steel plate, or a metal surface thereof. A metal plate subjected to an edible surface treatment is press-molded or cut and subjected to an anticorrosive 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 a circular anode-side power feeder provided on both surfaces of the solid polymer electrolyte membrane 38. 40 and a cathode side power supply body 42. The peripheral edge of the solid polymer electrolyte membrane 38 protrudes outward from the outer peripheries of the anode side power supply body 40 and the cathode side power supply body 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 a smooth surface portion that is etched after grinding, and the porosity is set within a range of 10% to 50%, more preferably 20% to 40%. Is done.

  As shown in FIG. 3, a first protrusion 44 a, a second protrusion 44 b, and a third protrusion 44 c that protrude outward in the separator surface direction are formed on the outer periphery of the unit cell 12. The first protrusion 44a is provided with a water supply communication hole 46 that communicates with each other in the direction of the arrow A that is the stacking direction and supplies water (pure water) that is the first fluid.

  The second projecting portion 44b is provided with a discharge communication hole 48 that communicates with each other in the direction of the arrow A and discharges oxygen generated by the reaction and used water. The third projecting portion 44c is provided with a hydrogen communication hole 50 that communicates with each other in the direction of arrow A, which is the stacking direction, for flowing hydrogen generated by the reaction.

  As shown in FIG. 4, the water supply communication hole 46 and the discharge communication hole 48 have an oval cross-sectional shape and are arranged at points symmetrical with each other. An imaginary straight line L1 connecting the water supply communication hole 46 and the discharge communication hole 48 passes through the center O of the unit cell 12, and a cross-sectional circle is formed on the imaginary orthogonal line L2 orthogonal to the virtual straight line L1 and passing through the center O. A hydrogen communication hole 50 having a shape is arranged. The water supply communication hole 46 and the discharge communication hole 48 are set to have a larger opening cross-sectional area than the hydrogen communication hole 50.

  As shown in FIGS. 3 and 5, the anode separator 34 is provided with a supply passage 52 a that communicates with the water supply communication hole 46 and a discharge passage 52 b that communicates with the discharge communication hole 48. A first flow path 54 communicating with the supply passage 52a and the discharge passage 52b is provided on the surface 34a of the anode separator 34 facing the electrolyte membrane / electrode structure 32. The first flow path 54 is provided in a range corresponding to the surface area of the anode-side power feeding body 40, and includes a plurality of flow path grooves, a plurality of embosses, and the like (see FIGS. 2 and 5).

  As shown in FIGS. 3 and 5, the cathode-side separator 36 is provided with a discharge passage 56 that communicates with the hydrogen communication hole 50. A second flow path 58 communicating with the discharge passage 56 is formed on the surface 36 a of the cathode separator 36 facing the electrolyte membrane / electrode structure 32. The second flow path 58 is provided within a range corresponding to the surface area of the cathode-side power feeding body 42, and includes a plurality of flow path grooves, a plurality of embosses, and the like (see FIGS. 2 and 5).

  The seal members 60a and 60b are integrated with each other around the outer peripheral ends of the anode side separator 34 and the cathode side separator 36. The seal members 60a and 60b include, for example, EPDM, NBR, fluorine rubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene, acrylic rubber, or other seal materials, cushion materials, or packing materials. Used.

  As shown in FIG. 3 and FIG. 5, the surface 34 a of the anode-side separator 34 facing the electrolyte membrane / electrode structure 32 circulates outward from the first flow path 54 and the anode-side power feeding body 40, and thus the second seal. A second seal groove (second seal portion) 64a for disposing the member 62a is formed.

  On the surface 34a, the third seal member 62b, the fourth seal member 62c, and the fifth seal member 62d are arranged around the outside of the water supply communication hole 46, the discharge communication hole 48, and the hydrogen communication hole 50. A third seal groove (third seal portion) 64b, a fourth seal groove (fourth seal portion) 64c, and a fifth seal groove (fifth seal portion) 64d are formed. The second seal member 62a to the fifth seal member 62d are, for example, O-rings.

  On the surface 36a of the cathode side separator 36 facing the electrolyte membrane / electrode structure 32, the second seal 58a is disposed for circulating the second flow path 58 and the cathode side power supply body 42 outward. One seal groove (first seal portion) 68a is formed.

  As shown in FIGS. 3 and 5, the surface 36 a circulates outside the water supply communication hole 46, the discharge communication hole 48, and the hydrogen communication hole 50, so that the third seal member 66 b, the fourth seal member 66 c, A third seal groove (third seal portion) 68b, a fourth seal groove (fourth seal portion) 68c, and a fifth seal groove (fifth seal portion) 68d for disposing the five seal members 66d are formed. The first seal member 66a, the third seal member 66b to the fifth seal member 66d are, for example, O-rings.

  The second seal groove 64a that goes around the outside of the anode-side power supply body 40 and the first seal groove 68a that goes around the outside of the cathode-side power supply body 42 are solid polymer in the separator stacking direction (arrow A direction). The positions are set different from each other with the electrolyte membrane 38 interposed therebetween.

  The fifth seal groove 64d that circulates outward from the hydrogen communication hole 50 and the fifth seal groove 68d that circulates outward from the hydrogen communication hole 50 sandwich each other across the solid polymer electrolyte membrane 38 in the direction of arrow A. Set to a different position.

  In the cathode side separator 36, a recess 70 that is closed by the solid polymer electrolyte membrane 38 is formed in the first separator flat portion 36 aa that is located outside the first seal groove 68 a and faces the solid polymer electrolyte membrane 38. It is formed. The recess 70 has a substantially ring shape and is formed between the first seal groove 68a, the third seal groove 68b, the fourth seal groove 68c, and the fifth seal groove 68d.

  The flat portion other than the concave portion 70 of the first separator flat portion 36aa and the second separator flat portion 34aa facing the first separator flat portion 36aa of the anode side separator 34 are stacked in the stacking direction with the solid polymer electrolyte membrane 38 interposed therebetween. The pressure receiving part 72 which receives the load of is comprised. The pressure receiving portion 72 is set to a distance H between the fifth seal groove 68d and the second seal groove 64a with respect to the stacking direction, and the recess 70 is formed within a predetermined size range within the distance H.

  As shown in FIGS. 1 and 2, pipes 76a, 76b and 76c communicating with the water supply communication hole 46, the discharge communication hole 48 and the hydrogen communication hole 50 are connected to the end plate 20a. Although not shown, the pipe 76c is provided with a back pressure valve (or electromagnetic valve), and the pressure of hydrogen generated in the hydrogen communication hole 50 can be maintained at a high pressure. A pressing force is applied between the end plates 20 a and 20 b by a pressing force applying device (not shown), and the end plates 20 a and 20 b are tightened via the tie rods 22 in this state.

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

  As shown in FIG. 1, water is supplied from a pipe 76a to the water supply communication hole 46 of the water electrolysis apparatus 10, and a power supply 28 electrically connected to the terminal portions 24a and 24b of the terminal plates 16a and 16b is provided. A voltage is applied via For this reason, as shown in FIG. 3, in each unit cell 12, water is supplied from the water supply communication hole 46 to the first flow path 54 of the anode separator 34, and this water flows along the anode power supply body 40. Moving.

  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 58 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 communication hole 46, and can flow out of the water electrolysis apparatus 10 through the hydrogen communication hole 50. On the other hand, oxygen generated by the reaction and used water flow in the first flow path 54, and these are discharged to the outside of the water electrolysis apparatus 10 along the discharge communication hole 48.

  In this case, in the first embodiment, as shown in FIG. 5, the cathode separator 36 has a first separator flat portion located outside the first seal groove 68 a and facing the solid polymer electrolyte membrane 38. A recess 70 that is closed by the solid polymer electrolyte membrane 38 is formed in 36aa. The flat portion other than the concave portion 70 of the first separator flat portion 36aa and the second separator flat portion 34aa facing the first separator flat portion 36aa of the anode side separator 34 sandwich the solid polymer electrolyte membrane 38. The pressure receiving part 72 which receives the load of the lamination direction is comprised.

  For this reason, in the pressure receiving part 72, the pressing force application area (applied surface pressure area) can be effectively reduced. In particular, in the water electrolysis apparatus 10 which is a high-pressure hydrogen production apparatus in which high-pressure hydrogen is generated in the second flow path 58, the pressing pressure applied in the stacking direction of the unit cells 12 is considerably large in order to perform high-pressure sealing. Easy to be.

  Here, in the first embodiment, since the pressing force application area of the pressure receiving portion 72 is effectively reduced as described above, the external pressing force application device (not shown) can be easily downsized. As a result, it is possible to obtain a desired seal surface pressure.

  Further, the recess 70 is formed within a distance H between the fifth seal groove 68d and the second seal groove 64a with respect to the stacking direction, and overlaps with the second seal member 62a to the fifth seal member 62d in the stack direction. There is nothing. Therefore, it is possible to satisfactorily prevent the occurrence of seal failure.

  Furthermore, as shown in FIG. 4, the water supply communication hole 46 and the discharge communication hole 48 are arranged at point-symmetric positions, and are virtual straight lines that connect the water supply communication hole 46 and the discharge communication hole 48. A hydrogen communication hole 50 is provided on a virtual orthogonal line L2 orthogonal to L1. For this reason, when the reaction force acts on the anode separator 34 and the cathode separator 36 due to the high pressure hydrogen being led out to the hydrogen communication hole 50, the reaction force is applied to the water supply communication hole 46 and the discharge communication hole 48. Evenly distributed.

  Moreover, the water supply communication hole 46 and the discharge communication hole 48 are set to have a larger opening cross-sectional area than the hydrogen communication hole 50. Therefore, the unit cell 12 can have a good sealing function in a stable state by the seal structure of the water supply communication hole 46 and the seal structure of the discharge communication hole 48.

  As a result, the seal pressure of the water supply communication hole 46 and the discharge communication hole 48 having a relatively low pressure (normal pressure) can be maintained evenly with a simple configuration, and deterioration of the sealing performance is prevented as much as possible. The effect that it becomes possible is acquired.

  FIG. 6 is an explanatory cross-sectional view of a unit cell 82 constituting a water electrolysis apparatus 80 according to the second embodiment of the present invention.

  In addition, the same referential mark is attached | subjected to the component same as the unit cell 12 which comprises the water electrolysis apparatus 10 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted. Similarly, in the third embodiment described below, detailed description thereof is omitted.

  The unit cell 82 includes an anode side separator 84 and a cathode side separator 86 that sandwich the electrolyte membrane / electrode structure 32. The anode-side separator 84 has a recess 88 that is closed by the solid polymer electrolyte membrane 38 in the second separator flat portion 84aa that is located outside the second seal groove 64a and faces the solid polymer electrolyte membrane 38. It is formed. The recess 88 has a substantially ring shape and is formed between the second seal groove 64a, the third seal groove 64b, the fourth seal groove 64c, and the fifth seal groove 64d.

  The flat portion other than the concave portion 88 of the second separator flat portion 84aa and the first separator flat portion 86aa facing the second separator flat portion 84aa of the cathode side separator 86 are stacked in the stacking direction with the solid polymer electrolyte membrane 38 interposed therebetween. The pressure receiving part 90 which receives the load of is comprised. The recess 88 is formed in a predetermined size range within a distance H between the fifth seal groove 68d and the second seal groove 64a with respect to the stacking direction.

  In the second embodiment configured as described above, a flat portion other than the concave portion 88 of the second separator flat portion 84aa, and a first separator flat portion 86aa facing the second separator flat portion 84aa of the cathode side separator 86, Constitutes a pressure receiving portion 90 that receives a load in the stacking direction with the solid polymer electrolyte membrane 38 interposed therebetween.

  As a result, the pressing force application area of the pressure receiving unit 90 is effectively reduced, so that an external pressing force application device (not shown) can be easily reduced in size and a desired seal surface pressure can be secured. For example, the same effects as those of the first embodiment can be obtained.

  FIG. 7 is an explanatory cross-sectional view of the unit cell 102 constituting the water electrolysis apparatus 100 according to the third embodiment of the present invention.

  The unit cell 102 includes an anode-side separator 104 and a cathode-side separator 106 that sandwich the electrolyte membrane / electrode structure 32. The cathode-side separator 106 has a recess 70 that is closed by the solid polymer electrolyte membrane 38 in the first separator flat portion 106aa that is located outside the first seal groove 68a and faces the solid polymer electrolyte membrane 38. It is formed.

  The anode-side separator 104 has a recess 88 that is closed by the solid polymer electrolyte membrane 38 in the second separator flat portion 104aa that is located outside the second seal groove 64a and faces the solid polymer electrolyte membrane 38. It is formed. The flat portion other than the concave portion 70 of the first separator flat portion 106aa and the flat portion other than the concave portion 88 of the second separator flat portion 104aa define the pressure receiving portion 108 that receives a load in the stacking direction across the solid polymer electrolyte membrane 38. Constitute.

  In the third embodiment configured as described above, the same effects as those of the first and second embodiments can be obtained.

DESCRIPTION OF SYMBOLS 10, 80, 100 ... Water electrolysis apparatus 12, 82, 102 ... 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 / electrode structure 34, 84, 104 ... anode side separator 34aa, 36aa, 84aa, 86aa, 104aa, 106aa ... separator flat part 36, 86, 106 ... cathode side separator 38 ... solid polymer electrolyte membrane 40 ... anode side Power feeding body 42 ... Cathode side power feeding bodies 44a to 44c ... Projection 46 ... Water supply communication hole 48 ... Discharge communication hole 50 ... Hydrogen communication hole 54, 58 ... Flow paths 62a to 62d, 66a to 66d ... Seal members 64a to 64d, 68a to 68d ... seal grooves 70, 88 ... concave portions 72, 90, 108 ... pressure receiving portions

Claims (3)

A separator is stacked on a power supply body provided on both sides of the electrolyte membrane, and sandwiches a peripheral edge portion of the electrolyte membrane between the pair of separators, and one separator wraps around the outside of the power supply body. A first seal portion for disposing one seal member is formed, and a second seal member is disposed on the other separator around the outside of the other power feeding body. A water electrolysis apparatus in which a seal portion is formed, and the first seal portion and the second seal portion are set at different positions across the electrolyte membrane with respect to the stacking direction of the separator,
In at least one of the separators, a concave portion that is closed by the electrolyte membrane is formed in a first separator flat portion that is located outside the first seal portion and faces the electrolyte membrane,
The flat portion other than the concave portion of the first separator flat portion and the second separator flat portion facing the first separator flat portion of the other separator receive a load in the stacking direction across the electrolyte membrane. A water electrolysis apparatus comprising a pressure receiving portion. The water electrolysis apparatus according to claim 1, wherein the water electrolysis apparatus electrolyzes water to produce oxygen and hydrogen having a pressure higher than normal pressure.
In the pair of separators, a third seal portion for circulating a water supply communication hole for circulating the water in the stacking direction to dispose a third seal member;
A fourth seal portion for circulating the unreacted water and oxygen in the stacking direction around the discharge communication hole and disposing a fourth seal member;
A fifth seal portion for circulating the hydrogen in the stacking direction around the hydrogen communication hole and disposing a fifth seal member;
Is formed,
At least in the first separator plane or the second separator plane, the recess is formed between the first seal portion, the third seal portion, the fourth seal portion, and the fifth seal portion. A water electrolysis apparatus characterized by the above. The water electrolysis apparatus according to claim 2, wherein the power supply body has a circular shape,
The water supply communication hole and the discharge communication hole are set to have a larger opening cross-sectional area than the hydrogen communication hole,
The water electrolysis apparatus, wherein the water supply communication hole and the discharge communication hole are arranged at symmetrical positions of the separator.

Images