JP7713435B2 - Hydrogen/oxygen generating device and hydrogen gas production method - Google Patents

Description

The present invention relates to a hydrogen/oxygen generating device equipped with an electrolysis module that electrolyzes water to generate hydrogen gas and oxygen gas, and a hydrogen gas production method for producing hydrogen gas using such a hydrogen/oxygen generating device.

In recent years, opportunities to use hydrogen gas as a clean energy source have expanded, and the electrolysis of water is a widely known method for obtaining such hydrogen gas. Hydrogen and oxygen generating devices equipped with an electrolysis module for electrolyzing water are known for producing such hydrogen gas.

A type of electrolysis module for hydrogen and oxygen generation equipment is known that includes a cell stack in which multiple electrolysis cells are stacked, each of which includes a solid polymer electrolyte membrane and a cathode chamber and an anode chamber adjacent to each other via the solid polymer electrolyte membrane. Pure water is passed through the anode side of the solid polymer electrolyte membrane, oxygen gas and hydrogen ions are generated by electrolysis, the hydrogen ions are moved from the anode side to the cathode side within the solid polymer electrolyte membrane, and hydrogen gas is generated on the cathode side.

In this type of electrolysis module, a path for supplying water, a path for discharging oxygen gas, and a path for discharging hydrogen gas are provided so as to penetrate the cell stack, the water supply path and the oxygen gas discharge path are each provided so as to communicate with all the anode chambers, and the hydrogen gas discharge path is provided so as to communicate with all the cathode chambers. This type of electrolysis module also includes a water supply port for supplying water to the anode chamber through the water supply path, an outlet for oxygen gas discharged through the oxygen gas discharge path, and an outlet for hydrogen gas discharged through the hydrogen gas discharge path. This type of electrolysis module is configured so that oxygen gas and hydrogen gas are discharged from the oxygen gas discharge port and the hydrogen gas discharge port, respectively, by supplying water from the water supply port while supplying electric power.

In electrolysis cells, pinholes can occur in the solid polymer electrolyte membrane due to chemical deterioration, etc. For this reason, in hydrogen/oxygen generation devices, the hydrogen concentration in the oxygen gas discharged from the oxygen gas outlet is measured to detect the occurrence of such pinholes (see paragraph 0042 of Patent Document 1 below, etc.).

JP 2022-80108 A

When an abnormality such as a pinhole occurs in the solid polymer electrolyte membrane of a hydrogen/oxygen generating device, it is usually difficult to determine which electrolysis cell has the abnormality without dismantling the cell stack. In addition, since it is difficult to reassemble a cell stack that has been dismantled, when an abnormality such as a pinhole occurs, the repair method is to replace the entire cell stack. Therefore, the service life of all the electrolysis cells in the cell stack is determined by the electrolysis cell with the shortest life, and many electrolysis cells are discarded before the end of their service life. Therefore, in a hydrogen gas production method that produces hydrogen gas using such a device, it is difficult to suppress the consumption of replacement parts, and it is difficult to produce hydrogen gas efficiently. The present invention has been made with an eye on such problems, and aims to extend the service life of the electrolysis cells and improve the efficiency of hydrogen gas production.

To solve the above problems, the present invention provides:
An electrolysis module is provided for electrolyzing water to generate hydrogen gas and oxygen gas,
The electrolysis module includes an oxygen gas outlet for discharging the oxygen gas and a hydrogen gas outlet for discharging the hydrogen gas,
The electrolysis module includes a cell stack in which a plurality of electrolysis cells are stacked,
each of the plurality of electrolysis cells includes a solid polymer electrolyte membrane, and a cathode chamber and an anode chamber adjacent to each other with the solid polymer electrolyte membrane interposed therebetween, and is configured such that water is supplied to the anode chamber, the oxygen gas is discharged from the anode chamber, and the hydrogen gas is discharged from the cathode chamber;
the cell stack is provided with a hydrogen gas exhaust path that penetrates the electrolytic cells in a direction in which the electrolytic cells are stacked and communicates with the cathode chamber of each of the electrolytic cells;
A hydrogen and oxygen generation device configured so that the hydrogen gas generated in the cathode chamber of each of the plurality of electrolysis cells is discharged from the hydrogen gas discharge port through the hydrogen gas discharge path,
Further comprising one or more intermediate plates interposed between one end side and the other end side of the cell stack in a stacking direction,
The intermediate plate divides the cell stack into a plurality of blocks,
the electrolysis module includes a plurality of water supply ports for supplying the water to each of the plurality of blocks, and a plurality of oxygen gas discharge ports for discharging the oxygen gas from each of the plurality of blocks;
the intermediate plate is made of a gas impermeable material and has a vent portion for passing the hydrogen gas at a position corresponding to the hydrogen gas exhaust path;
The present invention provides a hydrogen/oxygen generating device that is configured so that the hydrogen gas discharged from the plurality of blocks can be discharged from the hydrogen gas discharge port while regulating the movement of the water and the oxygen gas between the blocks.

To solve the above problems, the present invention provides:
A hydrogen gas production method for producing hydrogen gas using a hydrogen/oxygen generation device including an electrolysis module that electrolyzes water to generate hydrogen gas and oxygen gas, comprising:
The hydrogen and oxygen generating device comprises:
The electrolysis module includes an oxygen gas outlet for discharging the oxygen gas and a hydrogen gas outlet for discharging the hydrogen gas,
The electrolysis module includes a cell stack in which a plurality of electrolysis cells are stacked,
each of the plurality of electrolysis cells includes a solid polymer electrolyte membrane, and a cathode chamber and an anode chamber adjacent to each other with the solid polymer electrolyte membrane interposed therebetween, and is configured such that water is supplied to the anode chamber, the oxygen gas is discharged from the anode chamber, and the hydrogen gas is discharged from the cathode chamber;
the cell stack is provided with a hydrogen gas exhaust path that penetrates the electrolytic cells in a direction in which the electrolytic cells are stacked and communicates with the cathode chamber of each of the electrolytic cells;
The hydrogen gas generated in the cathode chamber of each of the plurality of electrolysis cells is discharged from the hydrogen gas discharge port through the hydrogen gas discharge path,
Further comprising one or more intermediate plates interposed between one end side and the other end side of the cell stack in a stacking direction,
The intermediate plate divides the cell stack into a plurality of blocks,
the electrolysis module includes a plurality of water supply ports for supplying the water to each of the plurality of blocks, and a plurality of oxygen gas discharge ports for discharging the oxygen gas from each of the plurality of blocks;
the intermediate plate is made of a gas impermeable material and has a vent portion for passing the hydrogen gas at a position corresponding to the hydrogen gas exhaust path;
the hydrogen/oxygen generating device is configured to be able to discharge the hydrogen gas discharged from the plurality of blocks through the hydrogen gas discharge port while restricting the movement of the water and the oxygen gas between the blocks;
operating the electrolysis module to produce hydrogen gas;
and stopping the operation of the electrolysis module to inspect the solid polymer electrolyte membrane.
In the inspection, a pressure difference is generated between the cathode chamber and the anode chamber to measure the gas permeability of the solid polymer electrolyte membrane.

In the present invention, the cell stack is divided into multiple blocks, so that abnormalities in the solid polymer electrolyte membrane can be detected on a block-by-block basis, and the electrolytic cells can be replaced on a block-by-block basis. This allows the electrolytic cells in blocks where no abnormalities are detected to continue to be used as is, thereby extending the service life of the electrolytic cells.

FIG. 1 is a schematic diagram of a hydrogen/oxygen generating apparatus according to one embodiment. FIG. 2 is a schematic front view showing the electrolysis module in the hydrogen/oxygen generation device of one embodiment. FIG. 3A is (a) a schematic diagram showing the fixing state of each block of electrolysis cells constituting each block of the cell stack, and (b) a schematic diagram showing the state in the direction of the a-a' arrows. Figure 3B is (a) a schematic diagram showing a fixing state different from that of Figure 3A, and (b) a schematic diagram showing the state in the direction of the arrows b-b'. FIG. 4 is a schematic diagram showing the configuration of the electrolysis module of FIG. FIG. 5 is a schematic plan view showing the electrolysis module of FIG. 2 as viewed from above (the direction of block arrow V in FIG. 2). FIG. 6A is a schematic plan view showing the shape of a gasket used in an electrolysis cell. FIG. 6B is a schematic plan view showing the shape of a gasket used in the electrolysis cell. FIG. 6C is a schematic plan view showing the shape of the intermediate plate. FIG. 7 is a schematic bottom view showing the electrolysis module of FIG. 2 as viewed from below (in the direction of block arrow VII in FIG. 2). FIG. 8 is a schematic side view showing the electrolysis module of FIG. 2 as viewed from the left side (the direction of block arrow VIII in FIG. 2). FIG. 9 is a schematic side view showing the electrolysis module of FIG. 2 as viewed from the right side (the direction of block arrow IX in FIG. 2). FIG. 10 is a schematic front view showing the electrolysis module in a hydrogen/oxygen generation device according to another embodiment. FIG. 11A is a schematic perspective view showing one mechanism for measuring the gas permeability of a solid polymer electrolyte membrane. FIG. 11B is a schematic perspective view showing a mechanism for measuring the gas permeability of a solid polymer electrolyte membrane, which is different from the mechanism shown in FIG. 11A. FIG. 11C is a schematic perspective view showing a mechanism for measuring the gas permeability of a solid polymer electrolyte membrane, which is different from the mechanisms shown in FIGS. 11A and 11B.

The embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the hydrogen/oxygen generating device 1 of this embodiment includes an electrolysis module 100 that electrolyzes water to generate hydrogen gas and oxygen gas. The hydrogen/oxygen generating device 1 of this embodiment has a tank 200 that stores water to be electrolyzed in the electrolysis module 100. The hydrogen/oxygen generating device 1 of this embodiment is configured to circulate water to the anode side of the electrolysis module 100. The hydrogen/oxygen generating device 1 of this embodiment is configured to supply water in excess of that consumed by electrolysis to the electrolysis module 100, discharge oxygen gas and water from the anode side of the electrolysis module 100 in the form of a gas-liquid mixed flow, return the gas-liquid mixed flow to the tank 200, and perform gas-liquid separation in the tank 200.

In FIG. 1, the gas-liquid mixture is returned to the tank 200, and gas-liquid separation is performed in the tank 200. However, a gas-liquid separation tank may be provided separately from the tank 200, and the gas-liquid mixture may be returned to the gas-liquid separation tank. A partition may be provided inside the tank 200 to separate the tank into a section for storing water electrolyzed in the electrolysis module 100 and a section to which the gas-liquid mixture is returned. The partition may be provided so that the gas phases in the tanks on one side and the other side adjacent to each other are connected through the partition, or they may be provided so that they are completely separate.

The hydrogen/oxygen generating device 1 of this embodiment further includes a gas-liquid separator 300 so that water permeating the membrane is accompanied by hydrogen gas and discharged from the cathode side of the electrolysis module 100, and the water and hydrogen gas can be separated. The hydrogen/oxygen generating device 1 of this embodiment further includes a water supply pipe L1 constituting a water transport path for supplying water from the tank 200 to the electrolysis module 100, an oxygen gas discharge pipe L2 constituting an oxygen transport path for discharging the gas-liquid mixture flow containing oxygen gas from the electrolysis module 100 and returning it to the tank 200, and a hydrogen gas discharge pipe L3 constituting a hydrogen transport path for discharging hydrogen gas from the electrolysis module 100.

The electrolysis module 100 includes a solid polymer electrolyte membrane. The hydrogen/oxygen generation device 1 further includes an inspection device 400 that measures the gas permeability of the solid polymer electrolyte membrane. In the following, the electrolysis module 100 is illustrated as being rectangular, but the electrolysis module may be cylindrical or have other shapes.

The electrolysis module 100 of this embodiment has a rectangular parallelepiped shape, and as shown in Figures 2, 4, and 6 to 8, the horizontal (left-right) dimension in front view is longer than the depth (front-back) dimension. In other words, the electrolysis module 100 has a shape that is a horizontally long rectangle when viewed from above or below. In the following description, a first direction along the long side of this rectangle is referred to as the horizontal direction X of the electrolysis module 100, a second direction along the short side is referred to as the depth direction Y of the electrolysis module 100, and a direction perpendicular to the first direction and second direction is referred to as the vertical direction Z of the electrolysis module 100.

The electrolysis module 100 of this embodiment is equipped with a water supply port 101 for introducing water to be electrolyzed in the electrolysis module 100 into the module, an oxygen gas outlet 102 for discharging oxygen gas obtained by electrolysis, and a hydrogen gas outlet 103 for discharging hydrogen gas obtained by electrolysis. The electrolysis module 100 is equipped with a cell stack 110 in which a plurality of electrolysis cells 10 are stacked in the vertical direction Z.

As shown in FIG. 3, each of the multiple electrolysis cells 10 includes a solid polymer electrolyte membrane 11, a cathode chamber 12, and an anode chamber 13 adjacent to each other vertically with the solid polymer electrolyte membrane interposed therebetween, and is configured such that water is supplied to the anode chamber 13, the oxygen gas is discharged from the anode chamber 13, and the hydrogen gas is discharged from the cathode chamber 12.

In the electrolysis cell 10 of this embodiment, the anode chamber 13 is disposed above the solid polymer electrolyte membrane 11, and the cathode chamber 12 is disposed below the solid polymer electrolyte membrane 11. Electrode plates 14 are disposed above the anode chamber 13 and below the cathode chamber 12 to supply electrical energy to the anode chamber 13 and the cathode chamber 12, respectively. In the electrolysis cell 10 of this embodiment, a gasket material (cathode gasket S2) surrounding the cathode chamber 12 and a gasket material (anode gasket S1) surrounding the anode chamber 13 are provided. That is, the outer periphery of the cathode chamber 12 and the anode chamber 13 are sealed with the gasket material, and the openings in the upper and lower directions are closed by the electrode plates 14 and the solid polymer electrolyte membrane 11, respectively, to form highly airtight spaces.

The cell stack 110 of this embodiment is composed of bipolar electrolytic cells 10, and one electrode plate 14 is used as an electrode plate for two electrolytic cells 10 adjacent to each other in the vertical direction Z. In the cell stack 110, there are no more than two cathode chambers 12 or anode chambers 13 consecutive in the vertical direction Z, and the cathode chambers 12 and anode chambers 13 are arranged alternately. One of the two surfaces of the electrode plate 14 is a cathode surface 14c facing the cathode chamber 12 of one of the two electrolytic cells 10 for which the electrode plate 14 is used, and the surface opposite to the cathode surface 14c is an anode surface 14a facing the anode chamber 13 of the other electrolytic cell 10.

In the electrolysis module 100 of this embodiment, two end plates 120, a first end plate 121 and a second end plate 122, are provided at both ends of the cell stack 110 in the vertical direction Z in which the electrolysis cells 10 are stacked. The first end plate 121 is arranged so as to contact one end side (upper end) of the one end side and the other end side of the stacking direction of the cell stack 110 from above, and the second end plate 122 is arranged so as to contact the other end side (lower end) of the one end side and the other end side of the stacking direction of the cell stack 110 from below.

The electrolysis module 100 of this embodiment further includes one or more intermediate plates 150 interposed between one end side and the other end side of the cell stack 110 in the stacking direction, and the cell stack 110 is divided into a plurality of blocks by the intermediate plates 150. In the electrolysis module 100 illustrated in FIG. 2, one intermediate plate 150 is interposed only at one location, and the cell stack 110 is divided into two blocks. Of the two blocks, the first block 111 is provided between the first end plate 121 and the intermediate plate 150, and the second block 112 is disposed between the intermediate plate 150 and the second end plate 122. The thickness of the first end plate 121 and the second end plate 122 is preferably thicker than the intermediate plate 150. The thickness of the first end plate 121 and the second end plate 122 is preferably thicker than the electrode plate 14.

The shape of the electrolytic cell 10 in plan view or bottom view when viewed along the stacking direction (vertical direction Z) in the electrolytic module 100 is a horizontally long rectangle, the same as the planar shape and bottom shape of the electrolytic module 100. The first block 111 and the second block 112 each have a rectangular shape in which a plurality of electrolytic cells 10 are stacked straight in the vertical direction Z. The first block 111 and the second block 112 are stacked vertically via the intermediate plate 150 with all the electrolytic cells 10 aligned in plan view or bottom view when viewed along the vertical direction. In this embodiment, the first end plate 121, the second end plate 122, and the intermediate plate 150 are rectangular plates each having a size equal to or larger than the electrolytic cell 10. In this embodiment, the first end plate 121, the second end plate 122, and the intermediate plate 150 are one size larger than the electrolytic cell 10 and are provided in the electrolytic module 100 in a state where they protrude from the first block 111 and the second block 112 in the front, back, left and right directions.

The intermediate plate 150 does not need to be larger than the electrolytic cell 10, and may be the same size as the electrolytic cell 10. The intermediate plate 150 may have a protrusion that protrudes outward from the electrolytic cell 10. The protrusion may be formed around the entire circumference, or may be provided on two opposing sides. The protrusion may be provided so as to protrude only a part of the two opposing sides. By providing the protrusion, a pressing member that presses the protrusion and the first end plate 121 so as to sandwich the first block 111 from the vertical direction can be installed, and when a defect occurs in the second block 112, the protrusion and the first end plate 121 can be sandwiched by the pressing member, making it possible to inspect only the second block 112 without disassembling the first block. On the other hand, when the protrusion and the second block 112 are sandwiched by the pressing member, it becomes possible to inspect the first block 111 without disassembling the second block. The protrusions can be provided so as to protrude 5 mm or more outward from the electrolysis cells 10 adjacent to the upper and lower sides of the intermediate plate 150. The protrusions may be provided so as to protrude 10 mm or more outward, 15 mm or more outward, or 20 mm or more outward.

The protrusion may be provided with a hole so that it can be moved by suspending or lifting it with a hoisting jig. In this case, it is more preferable to provide a similar hole for the hoisting jig in the first end plate 121 or the second end plate 122 so that the hole in the protrusion and the hole in the first end plate 121, the hole in the protrusion and the hole in the second end plate, or the hole in the protrusion and the hole in the first end plate 121 and the hole in the second end plate are in the same position in a plan view.

The intermediate plate 150 may be arranged in a stacked manner. For example, by arranging two plates in a stacked manner, when only one block is removed from the module, one side of the other block in the stacking direction is protected by the other intermediate plate 150, so that damage to the other block can be prevented. In this case, it is more preferable to change the size of each intermediate plate 150 or to ensure that the protruding parts of the intermediate plates 150 do not overlap when viewed in a plan view, taking into consideration ease of removal. There is no particular limit to the size of the intermediate plate 150, but since a fixing bolt passes through the outer periphery of the end plate, it is more preferable to place the intermediate plate 150 inside the position where the bolt passes. Note that a fastener for fastening two members, such as a bolt or a nut, can also apply pressure in the direction in which the members approach each other, and can be used as a pressing member as described above.

As a method for stacking multiple intermediate plates 150 to protect each block, for example, as shown in FIG. 3A, there is a method in which two intermediate plates 150, an upper plate 150a and a lower plate 150b, are arranged as intermediate plates 150 located inside the area through which the total fixing bolt B0 passes, which engages with each of the first end plate 121 and the second end plate 122 to fix the entire module as a unit.

In the example shown in FIG. 3A, a general bolt is used as the total fixing bolt B0 for fixing the entire module, which has a round bar-shaped shaft B0a with a screw thread on the outer circumferential surface and a head B0b with a larger diameter than the shaft, and the head B0b is provided on one end side in the longitudinal direction of the shaft B0a. In the example shown in FIG. 3A, a total fixing through hole H0 is provided as a through hole for fixing the entire module to the first end plate 121 and the second end plate 122. The total fixing through hole H0 penetrates the first end plate 121 and the second end plate 122 in the thickness direction, respectively, and is arranged so that a virtual axis extending vertically passes through the center of both. In the total fixing bolt B0, the shaft B0a has an outer diameter equal to or smaller than the inner diameter of the total fixing through hole H0, and the head B0b has a larger diameter than the total fixing through hole H0.

In the example shown in FIG. 3A, a full fixing bolt B0 with a shaft longer than the distance from the top surface 121a of the first end plate 121 to the bottom surface 122b of the second end plate is used, and a nut N0 is fitted to the tip of the shaft B0a that protrudes downward from the bottom surface 122b of the second end plate 122 to fix the first end plate 121 and the second end plate 122 together.

In the example shown in FIG. 3A, the first end plate 121 and the upper plate 150a are each provided with a first fixing through hole H1 so that the first block 111 can be sandwiched between them from above and below and the stacked state of the electrolysis cells 10 in the first block 111 can be fixed by the first fixing bolt B1. In the example shown in FIG. 3A, the second end plate 122 and the lower plate 150b are each provided with a second fixing through hole H2 so that the second block 112 can be fixed by the lower plate 150b and the second end plate 122 from above and below and the second fixing bolt B2 can be fixed.

In the electrolysis module 100 of this embodiment, the stacked state of the cell stack 110 is fixed by the full fixing bolt B0 in principle at all times, except when the electrolysis module 100 is dismantled. On the other hand, the first block 111 is fixed by the first fixing bolt B1 and the second block 112 is fixed by the second fixing bolt B2 when the electrolysis module 100 is dismantled, and is not fixed in principle during normal operation. It is preferable that the first fixing bolt B1 and the second fixing bolt B2 are each provided at a position that does not interfere with the full fixing bolt B0, and it is preferable that they can be attached and detached freely to the electrolysis module 100 to which the full fixing bolt B0 is attached.

The first fixing bolt B1 and the second fixing bolt B2 may be installed when necessary, except when the electrolysis module 100 is disassembled. If the entire fixing bolt B0, the first fixing bolt B1, and the second fixing bolt B2 can be installed even when the electrolysis module 100 is energized, they are installed while ensuring electrical insulation between the end plates and the intermediate plate to prevent the formation of an electrical short path.

In the example shown in FIG. 3A, the upper plate 150a is not provided at the position where the second fixing through hole H2 opens on the upper surface of the lower plate 150b, and the upper plate 150a has a cutout portion (hereinafter also referred to as "upper plate cutout portion 150a1") larger than the second fixing through hole H2 at a position corresponding to the second fixing through hole H2. Also, in the example shown in FIG. 3A, the lower plate 150b is not provided at the position where the first fixing through hole H1 opens on the lower surface of the upper plate 150a, and the lower plate 150b has a cutout portion (hereinafter "lower plate cutout portion 150b1") larger than the first fixing through hole H1 at a position corresponding to the first fixing through hole H1.

3A, in the electrolysis module 100 illustrated in this figure, the first fixing bolt B1 and the second fixing bolt B2, which are shorter than the total fixing bolt B0, can be used when removing the first block 111 and the second block 112 from the electrolysis module 100. The electrolysis module 100 is configured so that the first end plate 121 and the upper plate 150a are fastened to each other by passing the first fixing bolt B1 through the first fixing through hole H1, thereby sandwiching and fixing the first block 111 from above and below. The electrolysis module 100 is configured so that the lower plate 150b and the second end plate 122 are fastened to each other by passing the second fixing bolt B2 through the second fixing through hole H2, thereby sandwiching and fixing the second block 112 from above and below. Therefore, in the electrolysis module 100 illustrated in this figure, the first block 111 and the second block 112 can be removed individually while preventing the stacked state of the electrolysis cells 10 that constitute the first block 111 and the second block 112 from being destroyed from their original state.

The relationship between the shape of the first fixing bolt B1 and the second fixing bolt B2 and the first fixing through hole H1 and the second fixing through hole H2 is the same as that of the full fixing bolt B0 and the full fixing through hole H0. That is, the first fixing bolt B1 and the second fixing bolt B2 also have a round rod-shaped shaft portion with a thickness equal to or smaller than the first fixing through hole H1 and the second fixing through hole H2 and a screw cut on the outer periphery, and a head portion with a diameter larger than the first fixing through hole H1 and the second fixing through hole H2, and the length of the shaft portion is long enough to reach the intermediate plate 150 from each end plate 120. In addition, the first fixing bolt B1 is configured so that when the shaft portion is passed through the first fixing through hole H1 upward from the side of the upper plate 150a toward the first end plate 121, the head portion is fitted in the lower plate notch portion 150b1 and can be abutted against the lower surface of the upper plate 150a. In addition, the second fixing bolt B2 is configured so that when the shaft portion is passed through the second fixing through hole H2 downward from the lower plate 150b side toward the second end plate 122, the head portion fits into the upper plate cutout portion 150a1 and can abut against the upper surface of the lower plate 150b.

The first fixing bolt B1 illustrated in the figure has a head thickness (thickness in the length direction of the shaft) that is equal to or less than the thickness of the lower plate 150b, so that the head does not protrude below the lower surface of the lower plate 150b when the first block 111 is fixed, but the head may have a thickness that protrudes below the lower surface of the lower plate 150b. The second fixing bolt B2 illustrated in the figure has a head thickness (thickness in the length direction of the shaft) that is equal to or less than the thickness of the upper plate 150a, so that the head does not protrude above the upper surface of the upper plate 150a when the second block 112 is fixed, but the head of the second fixing bolt B2 may have a thickness that protrudes above the upper surface of the upper plate 150a.

Because of the above-mentioned structure, in the electrolysis module 100 illustrated in FIG. 3A, even if the first block 111 and the second block 112 are not fixed with the first fixing bolt B1 and the second fixing bolt B2 during assembly, the first block 111 and the second block 112 can be fixed later as necessary. Note that such an advantage can also be achieved when a through hole large enough to accommodate a head is provided instead of providing a notch in the upper plate 150a and the lower plate 150b.

If the first block 111 and the second block 112 are fixed in advance at the time of assembling the electrolysis module 100, a structure as exemplified in FIG. 3B may be adopted. The electrolysis module 100 illustrated in FIG. 3B is the same as the embodiment in FIG. 3A in that two intermediate plates 150, an upper plate 150a and a lower plate 150b, are stacked without an electrolysis cell 10 interposed therebetween. In the electrolysis module 100 in FIG. 3A, the outer peripheral edges of the upper plate 150a and the lower plate 150b are positioned inside the area through which the full fixing bolt B0 passes, but in the electrolysis module 100 illustrated in FIG. 3B, the upper plate 150a and the lower plate 150b are adopted whose outer peripheral edges reach the area through which the full fixing bolt B0 passes, and a full fixing through hole H0 is provided in both the upper plate 150a and the lower plate 150b so that the shaft portion B0a of the full fixing bolt B0 is inserted therethrough.

In the electrolysis module 100 illustrated in FIG. 3B, the lower surface of the upper plate 150a and the upper surface of the lower plate 150b are provided with countersunk portions (upper plate countersunk portion 150a2, lower plate countersunk portion 150b2), and the heads of the first fixing bolt B1 and the second fixing bolt B2 are accommodated in the countersunk portions. Even in such a case, the first block 111 and the second block 112 can be separated while maintaining the stacked structure of the electrolysis cell 10. In the embodiment illustrated in FIG. 3A and FIG. 3B, the electrolysis module 100 can be disassembled while the stacked state of each block is fixed. This not only facilitates the disassembly work, but also prevents the electrolysis cell 10 from being unintentionally displaced in blocks that do not need to be replaced when replacing a block that needs to be replaced.

As described above, the first fixing bolt B1 and the second fixing bolt B2 are usually attached when the electrolysis module 100 is disassembled. On the other hand, in the embodiment illustrated in FIG. 3B, the first fixing bolt B1 and the second fixing bolt B2 are always attached, so it is necessary to ensure electrical insulation between the end plate and the intermediate plate. In order to ensure electrical insulation, an electrically insulating member may be interposed between the first fixing bolt B1 and the second fixing bolt B2 and the end plate or the intermediate plate, or a bolt that is electrically insulating itself (e.g., a resin bolt or a ceramic bolt) may be used as the first fixing bolt B1 or the second fixing bolt B2. In order to simplify the configuration of the electrolysis module 100, it is preferable to adopt the configuration shown in FIG. 3A, and it is preferable that the first fixing bolt B1 and the second fixing bolt B2 are freely attachable and detachable when the entire electrolysis module 100 is fixed by the entire fixing bolt B0.

As shown in Figs. 5 and 7, the first end plate 121 and the second end plate 122 each have a water supply port 101 and an oxygen gas exhaust port 102. Specifically, the first end plate 121 is provided with two water supply ports 101 (hereinafter also referred to as "first water supply ports 101a") in a pair in the front and rear (depth direction Y) at one end side in the longitudinal direction (horizontal direction X) in a plan view, and two oxygen gas exhaust ports 102 (hereinafter also referred to as "first oxygen gas exhaust ports 102a") in a pair in the front and rear at the other end side in the longitudinal direction. That is, in the first end plate 121, which is a horizontally long rectangle in this embodiment, the water supply ports 101 are provided at two corners on one end side of the long side, and the oxygen gas exhaust ports 102 are provided at two corners on the other end side.

The water supply pipe L1 is connected to the water supply port 101 at the first end plate 121. As shown in Figures 11A to 11C, the water supply pipe L1 is provided with an on-off valve (hereinafter also referred to as "water supply valve V1") at the connection point with the water supply port 101. In other words, the electrolysis module 100 of this embodiment is switchable between a state in which flow with the outside via the water supply port 101 is possible and a state in which flow with the outside is blocked.

The oxygen gas exhaust pipe L2 is connected to the oxygen gas exhaust port 102 at the first end plate 121. The oxygen gas exhaust pipe L2 is provided with an on-off valve (hereinafter also referred to as the "oxygen gas exhaust valve V2") at the connection point with the oxygen gas exhaust port 102. In other words, the electrolysis module 100 of this embodiment is switchable between a state in which flow with the outside via the oxygen gas exhaust port 102 is possible and a state in which flow with the outside is blocked.

As shown in FIG. 5, the first end plate 121 is provided with two hydrogen gas exhaust ports 103: a first hydrogen gas exhaust port 103a provided between two first water supply ports 101a that are paired in the front and rear at one end in the longitudinal direction, and a second hydrogen gas exhaust port 103b provided between two first oxygen gas exhaust ports 102a that are paired in the front and rear at the other end in the longitudinal direction.

The hydrogen gas exhaust pipe L3 is connected to the hydrogen gas exhaust port 103 at the first end plate 121. The hydrogen gas exhaust pipe L3 is provided with an on-off valve (hereinafter also referred to as "hydrogen gas exhaust valve V3") at the connection point with the hydrogen gas exhaust port 103. In other words, the electrolysis module 100 of this embodiment is switchable between a state in which flow with the outside via the hydrogen gas exhaust port 103 is possible and a state in which flow with the outside is blocked.

As shown in FIG. 7, the second end plate 122 in this embodiment is provided with two water supply ports 101 (hereinafter also referred to as "second water supply ports 101b") that are paired with the two first water supply ports 101a provided in the first end plate 121 in the vertical direction Z. The second end plate 122 is also provided with two oxygen gas exhaust ports 102 (hereinafter also referred to as "second oxygen gas exhaust ports 102b") that are paired with the two first oxygen gas exhaust ports 102a provided in the first end plate 121 in the vertical direction Z. That is, the first end plate 121 and the second end plate 122 are common in that the water supply ports 101 are provided at two corners on one end side of the long side, and the oxygen gas exhaust ports 102 are provided at two corners on the other end side.

The water supply pipe L1 equipped with the water supply valve V1 is connected to the water supply port 101, which is the same on the second end plate 122 side. That is, the electrolysis module 100 of this embodiment can be switched between a state in which flow with the outside is possible via the second water supply port 101b and a state in which flow with the outside is blocked. Also, the oxygen gas exhaust pipe L2 equipped with the oxygen gas exhaust valve V2 is connected to the oxygen gas exhaust port 102, which is the same on the second end plate 122 side. That is, the electrolysis module 100 of this embodiment can be switched between a state in which flow with the outside is possible via the second oxygen gas exhaust port 102b and a state in which flow with the outside is blocked.

In this embodiment, the second end plate 122 does not have a hydrogen gas exhaust port 103, and the electrolysis module 100 can only extract hydrogen gas from the first end plate 121 side. Note that the electrolysis module 100 of this embodiment may also have a hydrogen gas exhaust port 103 connected to the first hydrogen gas exhaust path 161 or the second hydrogen gas exhaust path 162 in the second end plate 122, making it possible to extract hydrogen gas from both the top and bottom. In this case, too, a hydrogen gas exhaust pipe L3 equipped with an opening and closing valve can be connected to the hydrogen gas exhaust port 103 provided in the second end plate 122.

As shown in Figures 4, 8, 9, etc., the cell stack 110 in the electrolysis module 100 is provided with a hydrogen gas exhaust path 160 that penetrates the electrolysis cells 10 in the vertical direction Z in which the electrolysis cells 10 are stacked, and also penetrates the intermediate plate 150 to communicate with the cathode chamber 12 of each of the electrolysis cells 10. In this embodiment, two hydrogen gas exhaust paths 160, a first hydrogen gas exhaust path 161 and a second hydrogen gas exhaust path 162, are provided, and are provided at both ends of the electrolysis module 100 in the horizontal direction X, respectively.

The first hydrogen gas exhaust path 161 is connected to the first hydrogen gas exhaust port 103a and is provided so as to extend downward from the first hydrogen gas exhaust port 103a. The second hydrogen gas exhaust path 162 is connected to the second hydrogen gas exhaust port 103b and is provided so as to extend downward from the second hydrogen gas exhaust port 103b. The first hydrogen gas exhaust path 161 and the second hydrogen gas exhaust path 162 extend so as to reach the cathode chamber 12 provided at the lowest part of the cell stack 110.

All cathode chambers 12 provided in the electrolysis module 100 are connected to the hydrogen gas exhaust path 160 at one end and the other end in the horizontal direction X. The first hydrogen gas exhaust path 161 is connected to the cathode chamber 12 at the end on the left side when viewed from the front in FIG. 2, and the second hydrogen gas exhaust path 162 is connected to the cathode chamber 12 at the end on the right side. The first hydrogen gas exhaust path 161 and the second hydrogen gas exhaust path 162 are each connected to the cathode chamber 12 at the center in the depth direction Y. That is, the first hydrogen gas exhaust path 161 and the second hydrogen gas exhaust path 162 are provided in the electrolysis module 100 so as to extend vertically in the up-down direction Z at both ends in the horizontal direction X and at the center in the depth direction Y.

As shown in FIG. 6A, the hydrogen gas exhaust paths 160 of the first hydrogen gas exhaust path 161 and the second hydrogen gas exhaust path 162 are arranged so as to pass through a position away from the anode chamber 13 in the gasket material (anode gasket S1) that defines the periphery of the anode chamber 13 on the anode chamber side of the solid polymer electrolyte membrane 11. On the other hand, as shown in FIG. 6B, the hydrogen gas exhaust paths 160 of the first hydrogen gas exhaust path 161 and the second hydrogen gas exhaust path 162 pass through the gasket material (cathode gasket S2) on the cathode chamber side of the solid polymer electrolyte membrane 11 so as to communicate with the cathode chamber 12.

As shown in FIG. 6C, the intermediate plate 150 has a vent 151 for passing the hydrogen gas at a position corresponding to these hydrogen gas exhaust paths 160, so that the flow of hydrogen gas through the hydrogen gas exhaust path 160 is not blocked. In this embodiment, a through hole is provided in the first end plate 121 so as to extend the hydrogen gas exhaust path 160 upward, and the through hole serves as the hydrogen gas exhaust port 103. As described above, in this embodiment, two hydrogen gas exhaust paths 160 are provided in a pair in the horizontal direction X, namely, the first hydrogen gas exhaust port 103a provided at a position corresponding to the first hydrogen gas exhaust path 161 in the horizontal direction X and the depth direction Y, and the second hydrogen gas exhaust port 103b provided at a position corresponding to the second hydrogen gas exhaust path 162. In this embodiment, hydrogen gas can be extracted through two paths, but one of the hydrogen gas exhaust ports 103 may be blocked to extract hydrogen gas through only one path.

When multiple intermediate plates 150 are interposed at one location in the stacking direction, as in the above-mentioned upper plate 150a and lower plate 150b, a ventilation portion 151 is formed in each intermediate plate 150. The ventilation portion 151 may be formed by a through hole penetrating the intermediate plate 150 in the thickness direction, and when such a through hole is provided as the ventilation portion 151 in each of the upper plate 150a and the lower plate 150b, a sealing material (e.g., an O-ring) may be disposed surrounding the ventilation portion 151 so that hydrogen gas does not leak through the interface between the upper plate 150a and the lower plate 150b. The sealing material may be a conductive material such as a metal gasket or a metal O-ring.

In this embodiment, there are water supply paths 130 that extend vertically from each water supply port 101 and communicate with the anode chamber 13. The water supply paths 130 in this embodiment are not designed to pass through the intermediate plate 150 like the hydrogen gas exhaust path 160, and the water supply path 130 extending downward from the first water supply port 101a provided in the first end plate 121 and the water supply path 130 extending upward from the second water supply port 101b provided in the second end plate 122 are separated by the intermediate plate 150. That is, in this embodiment, the two water supply paths 130, namely, the first water supply path 131 that passes through the electrolytic cells 10 in the vertical direction Z in which the electrolytic cells 10 are stacked in the first block 111 and communicates with all the anode chambers 13 in the first block 111, and the second water supply path 132 that passes through the electrolytic cells 10 in the vertical direction Z in which the electrolytic cells 10 are stacked in the second block 112 and communicates with all the anode chambers 13 in the second block 112, are provided so as not to communicate with each other.

In this embodiment, there is an oxygen gas exhaust path 140 that extends vertically from each oxygen gas exhaust port 102 and communicates with the anode chamber 13. The oxygen gas exhaust path 140 in this embodiment is not designed to pass through the intermediate plate 150, as is the water supply port 101, and the oxygen gas exhaust path 140 extending downward from each of the two first oxygen gas exhaust ports 102a provided in the first end plate 121 and the oxygen gas exhaust path 140 extending upward from each of the two second oxygen gas exhaust ports 102b provided in the second end plate 122 are separated by the intermediate plate 150. That is, in this embodiment, the first oxygen gas exhaust path 141 penetrates the electrolytic cells 10 in the vertical direction Z in which the electrolytic cells 10 are stacked in the first block 111 and communicates with all the anode chambers 13 in the first block 111, and the second oxygen gas exhaust path 142 penetrates the electrolytic cells 10 in the vertical direction Z in which the electrolytic cells 10 are stacked in the second block 112 and communicates with all the anode chambers 13 in the second block 112. The two oxygen gas exhaust paths 140 are provided so as not to communicate with each other.

In the electrolysis module 100 of this embodiment, in electrolysis in the first block 111, water is supplied from the water supply pipe L1 connected to the first water supply port 101a provided in the first end plate 121, the supplied water is distributed through the first water supply path 131 to the multiple anode chambers 13 provided in the first block 111, oxygen gas and hydrogen ions are generated while the water passes from one end side to the other end side of the anode chamber 13, the oxygen gas is discharged through the first oxygen gas discharge path 141 and the oxygen gas discharge port 102 (first oxygen gas discharge port 102a) to the oxygen gas discharge pipe L2, and the hydrogen ions are moved to the cathode chamber 12 through the solid polymer electrolyte membrane 11 to generate hydrogen gas, and the hydrogen gas is discharged from the hydrogen gas discharge port 103 to the hydrogen gas discharge pipe L3 through the first hydrogen gas discharge path 161 and the second hydrogen gas discharge path 162 arranged at both ends of the cathode chamber 12.

The electrolysis module 100 in this embodiment is also configured so that, in electrolysis in the second block 112, water is supplied from the water supply pipe L1 connected to the second water supply port 101b provided in the second end plate 122, the supplied water is distributed through the second water supply path 132 to the multiple anode chambers 13 provided in the second block 112, oxygen gas and hydrogen ions are generated while the water is passed from one end side to the other end side of the anode chamber 13, the oxygen gas is discharged through the second oxygen gas discharge path 142 and the oxygen gas discharge port 102 (second oxygen gas discharge port 102b) to the oxygen gas discharge pipe L2, and the hydrogen ions are moved through the solid polymer electrolyte membrane 11 to the cathode chamber 12 to generate hydrogen gas, and the hydrogen gas can be discharged through the first hydrogen gas discharge path 161 and the second hydrogen gas discharge path 162 arranged at both ends of the cathode chamber 12 to the hydrogen gas discharge pipe L3 from the hydrogen gas discharge port 103 provided in the first end plate 121.

In the electrolysis module 100 of this embodiment, for example, an amount of water greater than that which is electrolyzed in the electrolysis cell 10 is supplied from the first water supply port 101a and the second water supply port 101b, and the oxygen gas produced by electrolysis and the water that remains unelectrolyzed are discharged in a gas-liquid mixture state from each of the first oxygen gas exhaust port 102a and the second oxygen gas exhaust port 102b.

As described above, in the electrolysis module 100 of this embodiment, the anode side space is divided by the intermediate plate 150 and the first block 111 and the second block 112 are independent of each other, while the cathode side space is connected between the first block 111 and the second block 112 to form a single space as a whole. The electrolysis module 100 is configured to restrict the movement of water and oxygen gas between the blocks while allowing hydrogen gas discharged from both blocks to be discharged through the same hydrogen gas discharge path 160 and hydrogen gas discharge port 103 in both blocks. By generating a pressure difference between the cathode chamber 12 and the anode chamber 13, the gas permeability of the solid polymer electrolyte membrane 11 can be easily measured, and it is possible to check for the presence of abnormalities such as pinholes in the solid polymer electrolyte membrane 11 for each block.

In the electrolysis module 100, the material of the intermediate plate 150 is preferably the same as that of the electrode plate, and the material of the intermediate plate 150 and the electrode plate 14 is preferably a conductive material, and these are preferably pure titanium or a titanium alloy. In the electrolysis module 100 of this embodiment, the power system that supplies power for electrolysis in the first block 111 and the power system that supplies power for electrolysis in the second block 112 may be separate systems by electrically insulating the first block 111 side and the second block 112 side at the location where the intermediate plate 150 is provided, but by configuring it so that it can be powered by one power system, the device configuration can be simplified. More specifically, the electrolysis module 100 of this embodiment is configured so that the first end plate 121 and the second end plate 122 are counter electrodes, and an anode potential is applied to the first end plate 121 and a cathode potential is applied to the second end plate 122, so that the first block 111 and the second block 112 can simultaneously perform electrolysis of water.

The electric power used for electrolysis in this embodiment may be what is called grid electric power, which is generated by thermal power generation or nuclear power generation, and is supplied over a wide area by a power transmission line, and is constantly and stably available, or may be electric power generated by renewable energy. Renewable energy may be, for example, solar power, wind power, wave power, tidal power, biomass, geothermal power, running water, etc. When grid electric power is used, stable electrolysis can be performed. When electric power generated by renewable energy is used, the power supply is likely to become unstable, but the time during which the operation is forced to be suspended can be easily used effectively for inspecting the solid polymer electrolyte membrane 11. In addition, when electric power generated by renewable energy is used, it is assumed that the power supply is unstable and the stress on the solid polymer electrolyte membrane 11 is large. Therefore, the effect of the present invention, which can avoid the replacement time of all electrolysis cells being determined by the electrolysis cell that has the earliest abnormality, can be more significantly demonstrated in such a situation where the electric power is difficult to stabilize.

In the electrolysis module 100 of this embodiment, when an abnormality such as a pinhole is detected in the solid polymer electrolyte membrane 11 or when such an abnormality is suspected, for example, the operation of the electrolysis module 100 is stopped, and then the flow between the water supply pipe L1 and the electrolysis module 100 is cut off, and the flow between the electrolysis module 100 and the oxygen gas exhaust pipe L2 and the flow between the electrolysis module 100 and the hydrogen gas exhaust pipe L3 are cut off, and the electrolysis module 100 is isolated from the surroundings in the hydrogen/oxygen generation device 1, and an inspection can be performed. In this case, the inspection may be performed while the electrolysis module 100 is still attached to the hydrogen/oxygen generation device 1, or may be performed after removing the electrolysis module 100 from the hydrogen/oxygen generation device 1. Then, as described above, a pressure difference is generated between the cathode chamber 12 and the anode chamber 13, and the soundness of the solid polymer electrolyte membrane 11 can be inspected. The inspection can be started after the inside of the electrolysis module 100 after the operation is stopped is purged with nitrogen gas and returned to atmospheric pressure.

Inspections may be performed periodically, not just in such cases. More specifically, when the hydrogen concentration in the gas discharged from the anode chamber 13 increases during operation, nitrogen gas is supplied from the hydrogen gas outlet 103 so that the cathode chamber 12 is at a higher pressure than the anode chamber 13, and the amount of gas discharged from one or both of the water supply port 101 and the oxygen gas outlet 102 is measured. If the amount of gas is equal to or greater than a reference value, it is determined that a pinhole has occurred in the membrane. Nitrogen gas can be supplied from a nitrogen gas cylinder or the like. Such inspections can be performed, for example, when the hydrogen gas concentration in the gas discharged from the anode chamber becomes 3000 ppm or more.

By using this method, the degree of gas permeability of the solid polymer electrolyte membrane 11 can be confirmed, and the soundness of the solid polymer electrolyte membrane 11 can be evaluated. In the case of nitrogen gas, the pressure of the gas supplied is equal to or lower than the allowable design pressure value of the electrolysis cell 10 used, or is equal to or higher than 0.2 MPa and lower than 1.0 MPa in terms of gauge pressure. The standard value of the gas amount is determined by the type of membrane and the pressure of the gas supplied.

In addition to the above method, nitrogen gas may be supplied to the anode chamber 13 through the hydrogen gas outlet 103 to create a state in which the pressure is higher than that of the cathode chamber 12, and the amount of gas discharged from the cathode chamber 12 through either the water supply port 101 or the oxygen gas outlet 102 or both may be measured, and if the amount of gas exceeds a reference value, it may be determined that a pinhole has occurred in the membrane.

To more reliably inspect the integrity of the solid polymer electrolyte membrane 11, the amount of gas passing through the solid polymer electrolyte membrane 11 may be measured twice in one inspection, but it may also be measured once.

It is also possible to inspect using gases other than nitrogen gas. For example, if a pinhole is suspected during operation of the electrolysis module 100, the power supply for electrolysis can be stopped, the supply of water can be continued on the anode chamber 13 side, and water can be discharged directly from the first oxygen gas outlet 102a and the second oxygen gas outlet 102b, while hydrogen gas can be kept pressurized on the cathode chamber 12 side, and the amount of hydrogen gas discharged together with the water discharged from the first oxygen gas outlet 102a and the second oxygen gas outlet 102b can be measured to check for abnormalities such as pinholes. That is, in this embodiment, pinhole inspection can also be performed using hydrogen gas instead of nitrogen gas.

The inspection does not need to be performed with the cathode chamber 12 under positive pressure, and can be performed with the anode chamber 13 under negative pressure. The inspection can also be performed with the anode chamber 13 under a higher pressure than the cathode chamber 12. For example, the anode chamber 13 of the first block 111 is filled with nitrogen gas, and the anode chamber 13 of the second block 112 is filled with oxygen gas, so that the anode chamber 13 is under a higher pressure than the cathode chamber 12. If a pinhole or the like is present, nitrogen gas or oxygen gas is moved to the cathode chamber 12, and the amount of gas discharged from the hydrogen gas discharge port 103 through the hydrogen gas discharge path 160 is measured, the soundness of the solid polymer electrolyte membrane 11 can be confirmed for each block.

As described above, the inspection of an electrolysis module having a cell stack divided into multiple blocks including a first block and a second block may be performed by simultaneously inspecting each block in parallel or sequentially. For example, the inspection may be performed by supplying a first gas to the anode chamber of the first block, checking the soundness of the first block, and then supplying a second gas, which is the same as the first gas or different from the first gas, to the anode chamber of the second block.

If an abnormality such as a pinhole is found in any of the blocks during the inspection, the electrolytic cell 10 in that block is replaced with a new one, and the same electrolytic cell 10 can be continued to be used for blocks in which no abnormality is found. In this way, the hydrogen/oxygen generation device of this embodiment can extend the service life of the electrolytic cell 10.

In the hydrogen gas production method using the hydrogen/oxygen generation device of this embodiment, the electrolysis module 100 is operated to produce hydrogen gas, and the operation of the electrolysis module 100 is stopped to inspect the solid polymer electrolyte membrane 11. In this inspection, a pressure difference is generated between the cathode chamber 12 and the anode chamber 13, and the gas permeability of the solid polymer electrolyte membrane 11 is measured, so that the soundness of the electrolysis cell 10 for each block can be easily confirmed. This makes it possible to reduce the consumption of replacement parts and to efficiently produce hydrogen gas.

In the hydrogen gas production method, there is a demand for an increase in the amount of hydrogen gas produced per unit time compared to conventional methods. In such cases, this can be achieved by increasing the number of electrolytic cells stacked in the cell stack compared to conventional methods. In the case of conventional methods, simply increasing the number of electrolytic cells stacked can result in a high-risk situation in which all electrolytic cells must be replaced if one of the electrolytic cells reaches the end of its life prematurely. On the other hand, in the method of this embodiment, the electrolytic cells can be replaced in block units, so the above-mentioned risks are unlikely to occur even if the hydrogen gas production capacity is increased.

More specifically, the inspection can be carried out using the mechanisms illustrated in Figures 11A, 11B, and 11C. In addition, it is preferable that the number of electrolytic cells (solid polymer electrolyte membranes) in each block to be inspected is 20 or more and 50 or less.

In the electrolysis module 100 illustrated in FIG. 11A, an on-off valve is provided in each of the connected pipes. In the electrolysis module 100 illustrated in FIG. 11A, a branch path (hereinafter also referred to as the "water supply branch path L11") is provided that can communicate the space outside the module with the first water supply path 131 without passing through an on-off valve (water supply valve V1). In addition, in the electrolysis module 100 illustrated in FIG. 11A, a branch path (hereinafter also referred to as the "hydrogen gas branch path L31") is provided that can communicate the space outside the module with the hydrogen gas exhaust path 160 without passing through an on-off valve (hydrogen gas exhaust valve V3). In the electrolysis module 100 illustrated in FIG. 11A, an on-off valve is installed between each branch path and the external space, so that the open/closed state of the branch path can be switched. In addition, instead of providing an on-off valve, the open/closed state of the branch path may be switched by attaching and detaching a seal plug or the like. Although not specified in FIG. 11A, a similar branch path is also provided on the second end plate 122 side. Furthermore, such branch paths do not have to be provided only for the first and second blocks, but can also be provided for each block when a third or subsequent block is provided.

The electrolysis module 100 illustrated in FIG. 11A has a branch path, which allows it to be inspected while the water supply pipe L1, oxygen gas exhaust pipe L2, and hydrogen gas exhaust pipe L3 are connected.

11A, the electrolysis module 100 is configured such that the water supply branch path L11 is connected to the water supply path 130 at the midpoint in the thickness direction of the first end plate 121 or the second end plate 122, and the water supply branch path L11 communicates with the external space through the side portion of the end plate. Also, the electrolysis module 100 illustrated in FIG. 11A is configured such that the hydrogen gas branch path L31 is connected to the hydrogen gas exhaust path 160 at the midpoint in the thickness direction of the first end plate 121 or the second end plate 122, and the hydrogen gas branch path L31 communicates with the external space through the side portion of the end plate. Note that the water supply branch path L11 or the hydrogen gas branch path L31 may be formed to communicate with the external space on the upper surface side of the first end plate 121 or the lower surface side of the second end plate as shown in FIG. 11B.

In this embodiment, it is preferable to configure the electrolysis module 100 so that the branch path and the external space are connected at the side of the end plate, as in the embodiment shown in FIG. 11A. Also, in this embodiment, it is preferable to provide one branch path on the cathode side, and one branch path on the anode side in each block, as in the embodiment shown in FIG. 11A. Note that the communication point between the branch path and the external space does not have to be the side of the end plate. Also, multiple branch paths may be provided on each of the cathode side and the anode side. Below, such an example will be described with reference to FIG. 11B and FIG. 11C.

The electrolysis module 100 illustrated in FIG. 11B is common to the electrolysis module 100 illustrated in FIG. 11A in that each connected pipe is provided with an on-off valve. The electrolysis module 100 illustrated in FIG. 11B is also provided with a branch path (water supply branch path L11) that can connect the space outside the module to the first water supply path 131 without passing through an on-off valve (water supply valve V1). In addition, the electrolysis module 100 illustrated in FIG. 11B is provided with a branch path (hereinafter also referred to as "oxygen gas branch path L21") that can connect the space outside the module to the first oxygen gas exhaust path 141 without passing through an on-off valve (oxygen gas exhaust valve V2). Furthermore, the electrolysis module 100 illustrated in FIG. 11B is provided with a branch path (hydrogen gas branch path L31) that can connect the space outside the module to the hydrogen gas exhaust path 160 without passing through an on-off valve (hydrogen gas exhaust valve V3). The electrolysis module 100 illustrated in FIG. 11B has an on-off valve between each branch path and the external space, making it possible to switch the on-off state of the branch path. Note that instead of providing an on-off valve, the on-off state of the branch path may be switched by attaching and detaching a seal plug, which is the same as the electrolysis module 100 illustrated in FIG. 11A. A similar branch path is also provided on the second end plate 122 side. This branch path is not only provided for the first block and the second block, but can also be provided for each block when a third or subsequent block is provided, which is the same as the electrolysis module 100 illustrated in FIG. 11A.

In the hydrogen/oxygen generation device 1 equipped with the electrolysis module 100 illustrated in FIG. 11C, a branch path is omitted and three-way valves are provided as opening/closing valves (water supply valve V1, oxygen gas exhaust valve V2, hydrogen gas exhaust valve V3). In the electrolysis module 100 illustrated in FIG. 11C, the water supply pipe L1, oxygen gas exhaust pipe L2, and hydrogen gas exhaust pipe L3 are connected to the electrolysis module 100 via three-way valves, and the paths from the electrolysis module 100 can be switched between each pipe and the outside space.

In the hydrogen/oxygen generation device 1 equipped with the electrolysis module 100 illustrated in FIG. 11C,
The device has three outlets, namely, a first outlet, a second outlet, and a third outlet;
a first state in which the first outlet and the second outlet are in communication with each other, and the first outlet and the third outlet and the second outlet and the third outlet are in communication with each other;
a three-way valve capable of switching between a first state in which the first outlet and the third outlet are in communication with each other and a second state in which the first outlet and the second outlet and the second outlet and the third outlet are in communication with each other;
The flow path from the first outlet to the third outlet of the three-way valve constitutes a water transport path, and the three-way valve is provided on the water supply pipe L1 so that the first outlet is on the side of the electrolysis module 100.
In addition, in the hydrogen/oxygen generation device 1 equipped with the electrolysis module 100 illustrated in FIG. 11C,
The device has three outlets, namely, a first outlet, a second outlet, and a third outlet;
a first state in which the first outlet and the second outlet are in communication with each other, and the first outlet and the third outlet and the second outlet and the third outlet are in communication with each other;
a three-way valve capable of switching between a first state in which the first outlet and the third outlet are in communication with each other and a second state in which the first outlet and the second outlet and the second outlet and the third outlet are in communication with each other;
The flow path from the first outlet to the third outlet of the three-way valve constitutes an oxygen transport path, and the three-way valve is provided in the oxygen gas exhaust pipe L2 so that the first outlet is on the side of the electrolysis module 100.
Furthermore, in the hydrogen/oxygen generation device 1 equipped with the electrolysis module 100 illustrated in FIG. 11C,
The device has three outlets, namely, a first outlet, a second outlet, and a third outlet;
a first state in which the first outlet and the second outlet are in communication with each other, and the first outlet and the third outlet and the second outlet and the third outlet are in communication with each other;
a three-way valve capable of switching between a first state in which the first outlet and the third outlet are in communication with each other and a second state in which the first outlet and the second outlet and the second outlet and the third outlet are in communication with each other;
The flow path from the first outlet to the third outlet of the three-way valve constitutes a hydrogen transport path, and a three-way valve is provided on the hydrogen gas exhaust pipe L3 so that the first outlet is on the side of the electrolysis module 100.
Therefore, in the hydrogen/oxygen generation device 1 equipped with the electrolysis module 100 illustrated in FIG. 11C, the second outlet of each three-way valve can be used as a gas inlet/outlet for inspection of the solid polymer electrolyte membrane.
An example of such an inspection of the electrolysis module 100 is given below.

When measuring the gas permeability of the solid polymer electrolyte membrane of the electrolysis module 100 illustrated in FIG. 11A, first, the operation of the electrolysis module 100 is stopped.
At this time, water may be continued to circulate on the anode side to expel as much oxygen gas as possible remaining in the anode chamber.
After oxygen gas has been sufficiently discharged from the electrolysis module 100, the supply of water to the electrolysis module 100 is temporarily stopped, and the opening/closing valves (water supply valve V1, oxygen gas exhaust valve V2) between the water supply pipe L1 and the oxygen gas exhaust pipe L2, which serve as the water return path, are closed.
Next, a pipe is connected to the water supply branch path L11, and the tip of the pipe is immersed in a separately prepared water tank. The material and shape of the pipe are not particularly limited, and a commercially available product such as a polytetrafluoroethylene tube can be used.
Next, the on-off valve of the hydrogen gas discharge pipe L3 is closed, the hydrogen gas branch path L31 is connected to a nitrogen gas cylinder, and the cathode chamber side is pressurized to a predetermined pressure.
The pressure generated in the cathode chamber during the inspection can be adjusted by providing a regulator on the nitrogen gas cylinder.
If, in this state, more than the specified amount of bubbles are discharged from the pipe, it can be assumed that more nitrogen gas than normal has permeated from the cathode chamber to the anode chamber, and it can be determined that pinholes or the like are present and the pipe is not sufficiently sound.
Then, by measuring the amount of bubbles (nitrogen gas) released from the tip of the pipe per unit time, it is possible to confirm the level of nitrogen gas leakage occurring in each block.

When measuring the gas permeability of the solid polymer electrolyte membrane of the electrolysis module 100 illustrated in FIG. 11B, first, the operation of the electrolysis module 100 is stopped.
At this time, water may be continued to circulate on the anode side to expel as much oxygen gas as possible remaining in the anode chamber.
After oxygen gas has been sufficiently discharged from the electrolysis module 100, the supply of water to the electrolysis module 100 is temporarily stopped, and the on-off valve of the oxygen gas discharge pipe L2, which serves as a water return path, is closed.
Next, a pipe is connected to the oxygen gas branch path L21, and the tip of this pipe is immersed in a water tank prepared separately. Two oxygen gas branch paths L21 are provided in each block, but each block may be connected to one pipe. In this case, the on-off valve of the oxygen gas branch path L21 to which no pipe is connected is closed, and only the on-off valve of the oxygen gas branch path L21 to which the pipe is connected is opened. The material and shape of the pipe are not particularly limited, and a commercially available product such as a polytetrafluoroethylene tube can be used.
The pipe may be connected to one of two water supply branch paths L11 provided in each block, instead of being connected to the oxygen gas branch path L21.
The pressure generated in the cathode chamber during the inspection can be adjusted by providing a regulator on the nitrogen gas cylinder.
If, in this state, more than the specified amount of bubbles are discharged from the pipe, it can be assumed that more nitrogen gas than normal has permeated from the cathode chamber to the anode chamber, and it can be determined that pinholes or the like are present and the pipe is not sufficiently sound.
In order to quickly discharge the nitrogen gas that has moved from the cathode chamber to the anode chamber, the supply of water to the anode chamber through the water supply pipe L1 may be continued until the end of the inspection.
Then, by measuring the amount of bubbles (nitrogen gas) released from the tip of the pipe per unit time, it is possible to confirm the level of nitrogen gas leakage occurring in each block.

The electrolysis module 100 shown in FIG. 11C can also be inspected for pinholes in the same manner as described above. As in the above, in the inspection, inspection gas can be supplied to the cathode chamber so that the cathode chamber is at a higher pressure than the anode chamber, and water can be supplied to the anode chamber to quickly discharge the inspection gas that has moved from the cathode chamber to the anode chamber from the electrolysis module 100.

In the electrolysis module 100 illustrated in FIG. 2 and other figures, the cell stack 110 is divided into two blocks, but in order to extend the service life of more electrolysis cells 10, the cell stack 110 may be divided into three blocks as shown in FIG. 10. In other words, the intermediate plate 150 does not have to be a single sheet, and may be multiple sheets as shown in FIG. 10.

In the embodiment shown in FIG. 10, there are multiple intermediate plates 150 including a first intermediate plate 150' and a second intermediate plate 150", and blocks formed by dividing the cell stack 110 are formed not only between the intermediate plates 150 and the end plates 120, but also between the intermediate plates 150, i.e., the first intermediate plate 150' and the second intermediate plate 150".

The electrolysis module 100 shown in FIG. 10 is the same as the electrolysis module 100 shown in FIG. 2 in that it has a first block 111 between the first end plate 121 and the intermediate plate 150, and a second block 112 between the second end plate 122 and the intermediate plate 150. The electrolysis module 100 shown in FIG. 10 is different from the electrolysis module 100 shown in FIG. 2 in that it has two intermediate plates 150, a first intermediate plate 150' that defines the first block 111 together with the first end plate 121, and a second intermediate plate 150" that defines the second block 112 together with the second end plate 122, and has a third block 113 between the two intermediate plates 150.

The fact that it is possible to fix the blocks by interposing a plurality of intermediate plates 150 between adjacent blocks is the same as in the embodiment shown in FIG. 10. That is, in this embodiment, a plurality of intermediate plates 150 such as the upper plate 150a and the lower plate 150b described above are stacked as intermediate plates 150 that separate adjacent blocks, and the intermediate plates 150 (upper plate 150a and lower plate 150b) are configured to be fastened with fasteners such as bolts and nuts to other intermediate plates 150 or end plates provided on the opposite side of the block to which the intermediate plates 150 contact, and the blocks can be disassembled while being fixed when the electrolysis module 100 is disassembled, which can facilitate the replacement of blocks that need to be replaced. This is also true when three or more blocks are provided.

The first intermediate plate 150' and the second intermediate plate 150" are similar to the intermediate plate 150 of the electrolysis module 100 illustrated in FIG. 2 in that they are preferably gas impermeable and the same as the electrode plate 14, are preferably made of a conductive material such as pure titanium or a titanium alloy, and have a vent in a position corresponding to the hydrogen gas exhaust path.

In the cell stack 110 in the electrolysis module 100 shown in Figure 10, the first intermediate plate 150' separating the two blocks, the first block 111 and the third block 113, differs from the intermediate plate 150 of the electrolysis module 100 illustrated in Figure 2 in that it is provided with a water supply port 101 (third water supply port 101c) communicating with the water supply path 130 in the third block 113, and an oxygen gas exhaust port 102 (third oxygen gas exhaust port 102c) communicating with the oxygen gas exhaust path 140 in the third block 113. On the other hand, the second intermediate plate 150" that separates the third block 113 and the second block 112 has a structure similar to that of the intermediate plate 150 of the electrolysis module 100 illustrated in FIG. 2. That is, the electrolysis module 100 illustrated in FIG. 10 is also common to the electrolysis module 100 illustrated in FIG. 2 in that the anode side spaces are independent for each block, while the cathode side spaces are connected between the blocks to form a single space overall.

The first intermediate plate 150' shown in FIG. 10 has the water supply port 101 and the oxygen gas exhaust port 102, and is configured to supply water to one of the two blocks adjacent to the first intermediate plate 150' and to exhaust oxygen gas from the one block. Therefore, for example, even if a third intermediate plate having a water supply port 101 and an oxygen gas exhaust port 102 similar to the first intermediate plate 150' is further inserted between the first intermediate plate 150' and the second intermediate plate 150" and the third block 113 is further divided into a total of four blocks, the third block 113 in FIG. 10 can be arranged in two rows between the first block 111 and the second block 112.

That is, the first intermediate plate 150' can separate the water supply path 130 and the oxygen gas exhaust path 140 in the stacking direction of the cell stack 110 simply by being inserted in the middle of the cell stack 110, and the first intermediate plate 150' has a water supply port 101 and an oxygen gas exhaust port 102 that can communicate with one of the water supply path 130 and the oxygen gas exhaust path 140 that are each divided into two via the first intermediate plate 150', so that a block can be formed by inserting the first intermediate plate 150' at any position of the cell stack 110. Even when three or more blocks are formed in this way, a pressure difference can be generated between the cathode chamber and the anode chamber in the same way as in the electrolysis module 100 shown in FIG. 2, and the solid polymer electrolyte membrane can be easily inspected.

Since the water supply pipe L1, oxygen gas exhaust pipe L2, etc. are also connected to this first intermediate plate 150', by providing a branch path or connecting the pipes via a three-way valve, the mechanism illustrated in Figures 11A to 11C can be applied to the first intermediate plate 150', and inspection can be performed without removing the pipes from the first intermediate plate 150'.

The above examples of the hydrogen/oxygen generating device and hydrogen gas production method of this embodiment are merely restrictive examples. Therefore, the hydrogen/oxygen generating device and hydrogen gas production method of the present invention are in no way limited to the above examples.

As stated above, this specification includes the following disclosures:

(1)
An electrolysis module is provided for electrolyzing water to generate hydrogen gas and oxygen gas,
The electrolysis module includes an oxygen gas outlet for discharging the oxygen gas and a hydrogen gas outlet for discharging the hydrogen gas,
The electrolysis module includes a cell stack in which a plurality of electrolysis cells are stacked,
each of the plurality of electrolysis cells includes a solid polymer electrolyte membrane, and a cathode chamber and an anode chamber adjacent to each other with the solid polymer electrolyte membrane interposed therebetween, and is configured such that water is supplied to the anode chamber, the oxygen gas is discharged from the anode chamber, and the hydrogen gas is discharged from the cathode chamber;
the cell stack is provided with a hydrogen gas exhaust path that penetrates the electrolytic cells in a direction in which the electrolytic cells are stacked and communicates with the cathode chamber of each of the electrolytic cells;
A hydrogen and oxygen generation device configured so that the hydrogen gas generated in the cathode chamber of each of the plurality of electrolysis cells is discharged from the hydrogen gas discharge port through the hydrogen gas discharge path,
Further comprising one or more intermediate plates interposed between one end side and the other end side of the cell stack in a stacking direction,
The intermediate plate divides the cell stack into a plurality of blocks,
the electrolysis module includes a plurality of water supply ports for supplying the water to each of the plurality of blocks, and a plurality of oxygen gas discharge ports for discharging the oxygen gas from each of the plurality of blocks;
the intermediate plate is made of a gas impermeable material and has a vent portion for passing the hydrogen gas at a position corresponding to the hydrogen gas exhaust path;
A hydrogen and oxygen generating device configured so that the hydrogen gas discharged from the plurality of blocks can be discharged from the hydrogen gas discharge port while restricting the movement of the water and the oxygen gas between the blocks.

(2)
the electrolysis module comprises two end plates, a first end plate and a second end plate;
In the electrolysis module, the first end plate and the second end plate are disposed at both ends of the cell stack in a direction in which the electrolysis cells are stacked,
the intermediate plate is interposed at only one location of the cell stack to divide the cell stack into two blocks, a first block on the first end plate side and a second block on the second end plate side;
the water supply port and the oxygen gas discharge port of the first block are opened to the first end plate,
the water supply port and the oxygen gas discharge port of the second block are opened to the second end plate,
2. The hydrogen and oxygen generating device according to claim 1, wherein the hydrogen gas exhaust port is opened in the first end plate.

(3)
A hydrogen/oxygen generation device as described in (1), in which the water supply port and the oxygen gas exhaust port are provided in the intermediate plate, and the device is configured to supply water to one of the two blocks adjacent to the intermediate plate through the intermediate plate, and to exhaust the oxygen gas from the one block through the intermediate plate.

(4)
The electrolysis module is configured such that the cell stack is composed of a bipolar electrolytic cell, the intermediate plate is composed of a conductive material, and the multiple blocks can be supplied with power from a single power system.

(5)
A hydrogen gas production method for producing hydrogen gas using a hydrogen/oxygen generation device including an electrolysis module that electrolyzes water to generate hydrogen gas and oxygen gas, comprising:
The hydrogen and oxygen generating device comprises:
The electrolysis module includes an oxygen gas outlet for discharging the oxygen gas and a hydrogen gas outlet for discharging the hydrogen gas,
The electrolysis module includes a cell stack in which a plurality of electrolysis cells are stacked,
each of the plurality of electrolysis cells includes a solid polymer electrolyte membrane, and a cathode chamber and an anode chamber adjacent to each other with the solid polymer electrolyte membrane interposed therebetween, and is configured such that water is supplied to the anode chamber, the oxygen gas is discharged from the anode chamber, and the hydrogen gas is discharged from the cathode chamber;
the cell stack is provided with a hydrogen gas exhaust path that penetrates the electrolytic cells in a direction in which the electrolytic cells are stacked and communicates with the cathode chamber of each of the electrolytic cells;
The hydrogen gas generated in the cathode chamber of each of the plurality of electrolysis cells is discharged from the hydrogen gas discharge port through the hydrogen gas discharge path,
Further comprising one or more intermediate plates interposed between one end side and the other end side of the cell stack in a stacking direction,
The intermediate plate divides the cell stack into a plurality of blocks,
the electrolysis module includes a plurality of water supply ports for supplying the water to each of the plurality of blocks, and a plurality of oxygen gas discharge ports for discharging the oxygen gas from each of the plurality of blocks;
the intermediate plate is made of a gas impermeable material and has a vent portion for passing the hydrogen gas at a position corresponding to the hydrogen gas exhaust path;
the hydrogen/oxygen generating device is configured to be able to discharge the hydrogen gas discharged from the plurality of blocks through the hydrogen gas discharge port while restricting the movement of the water and the oxygen gas between the blocks;
operating the electrolysis module to produce hydrogen gas;
and stopping the operation of the electrolysis module to inspect the solid polymer electrolyte membrane.
In the inspection, a pressure difference is generated between the cathode chamber and the anode chamber to measure the gas permeability of the solid polymer electrolyte membrane.

(6)
6. The method for producing hydrogen gas according to claim 5, wherein in the inspection, the gas permeability is measured by supplying nitrogen gas to the cathode chamber so that the cathode chamber is at a higher pressure than the anode chamber.

The present invention as described above makes it possible to extend the service life of electrolytic cells in hydrogen/oxygen generating devices and improve the efficiency of hydrogen gas production.

10: electrolytic cell, 11: solid polymer electrolyte membrane, 12: cathode chamber, 13: anode chamber, 14: electrode plate,
100: electrolysis module, 101: water supply port, 102: oxygen gas outlet, 103: hydrogen gas outlet,
110: cell stack, 111: first block, 112: second block,
120: end plate, 130: water supply path, 140: oxygen gas exhaust path,
150: intermediate plate, 151: ventilation section,
160: Hydrogen gas exhaust path

Claims (6)

An electrolysis module is provided for electrolyzing water to generate hydrogen gas and oxygen gas,
The electrolysis module includes an oxygen gas outlet for discharging the oxygen gas and a hydrogen gas outlet for discharging the hydrogen gas,
The electrolysis module includes a cell stack in which a plurality of electrolysis cells are stacked,
each of the plurality of electrolysis cells includes a solid polymer electrolyte membrane, and a cathode chamber and an anode chamber adjacent to each other with the solid polymer electrolyte membrane interposed therebetween, and is configured such that water is supplied to the anode chamber, the oxygen gas is discharged from the anode chamber, and the hydrogen gas is discharged from the cathode chamber;
the cell stack is provided with a hydrogen gas exhaust path that penetrates the electrolytic cells in a direction in which the electrolytic cells are stacked and communicates with the cathode chamber of each of the electrolytic cells;
A hydrogen and oxygen generation device configured so that the hydrogen gas generated in the cathode chamber of each of the plurality of electrolysis cells is discharged from the hydrogen gas discharge port through the hydrogen gas discharge path,
Further comprising one or more intermediate plates interposed between one end side and the other end side of the cell stack in a stacking direction,
The intermediate plate divides the cell stack into a plurality of blocks,
the electrolysis module includes a plurality of water supply ports for supplying the water to each of the plurality of blocks, and a plurality of oxygen gas discharge ports for discharging the oxygen gas from each of the plurality of blocks;
the intermediate plate is made of a gas impermeable material and has a vent portion for passing the hydrogen gas at a position corresponding to the hydrogen gas exhaust path;
A hydrogen and oxygen generating device configured so that the hydrogen gas discharged from the plurality of blocks can be discharged from the hydrogen gas discharge port while restricting the movement of the water and the oxygen gas between the blocks. the electrolysis module comprises two end plates, a first end plate and a second end plate;
In the electrolysis module, the first end plate and the second end plate are disposed at both ends of the cell stack in a direction in which the electrolysis cells are stacked,
the intermediate plate is interposed at only one location of the cell stack to divide the cell stack into two blocks, a first block on the first end plate side and a second block on the second end plate side;
the water supply port and the oxygen gas discharge port of the first block are opened to the first end plate,
the water supply port and the oxygen gas discharge port of the second block are opened to the second end plate,
2. The hydrogen and oxygen generating device according to claim 1, wherein the hydrogen gas exhaust port is opened in the first end plate. The hydrogen/oxygen generating device according to claim 1, in which the water supply port and the oxygen gas discharge port are provided on the intermediate plate, and the device is configured to supply water to one of the two blocks adjacent to the intermediate plate through the intermediate plate, and to discharge the oxygen gas from the one block through the intermediate plate. The hydrogen/oxygen generating device according to any one of claims 1 to 3, wherein the electrolysis module is configured such that the cell stack is composed of a bipolar electrolysis cell, the intermediate plate is composed of a conductive material, and the multiple blocks can be supplied with power from a single power system. A hydrogen gas production method for producing hydrogen gas using a hydrogen/oxygen generation device including an electrolysis module that electrolyzes water to generate hydrogen gas and oxygen gas, comprising:
The hydrogen and oxygen generating device comprises:
The electrolysis module includes an oxygen gas outlet for discharging the oxygen gas and a hydrogen gas outlet for discharging the hydrogen gas,
The electrolysis module includes a cell stack in which a plurality of electrolysis cells are stacked,
each of the plurality of electrolysis cells includes a solid polymer electrolyte membrane, and a cathode chamber and an anode chamber adjacent to each other with the solid polymer electrolyte membrane interposed therebetween, and is configured such that water is supplied to the anode chamber, the oxygen gas is discharged from the anode chamber, and the hydrogen gas is discharged from the cathode chamber;
the cell stack is provided with a hydrogen gas exhaust path that penetrates the electrolytic cells in a direction in which the electrolytic cells are stacked and communicates with the cathode chamber of each of the electrolytic cells;
The hydrogen gas generated in the cathode chamber of each of the plurality of electrolysis cells is discharged from the hydrogen gas discharge port through the hydrogen gas discharge path,
Further comprising one or more intermediate plates interposed between one end side and the other end side of the cell stack in a stacking direction,
The intermediate plate divides the cell stack into a plurality of blocks,
the electrolysis module includes a plurality of water supply ports for supplying the water to each of the plurality of blocks, and a plurality of oxygen gas discharge ports for discharging the oxygen gas from each of the plurality of blocks;
the intermediate plate is made of a gas impermeable material and has a vent portion for passing the hydrogen gas at a position corresponding to the hydrogen gas exhaust path;
the hydrogen/oxygen generating device is configured to be able to discharge the hydrogen gas discharged from the plurality of blocks through the hydrogen gas discharge port while restricting the movement of the water and the oxygen gas between the blocks;
operating the electrolysis module to produce hydrogen gas;
and stopping the operation of the electrolysis module to inspect the solid polymer electrolyte membrane.
In the inspection, a pressure difference is generated between the cathode chamber and the anode chamber to measure the gas permeability of the solid polymer electrolyte membrane. The hydrogen gas production method according to claim 5, wherein the inspection measures the gas permeability by supplying nitrogen gas to the cathode chamber so that the cathode chamber is at a higher pressure than the anode chamber.