JP7412480B2 - Water electrolysis device, water electrolysis method, water electrolysis system, water electrolysis/fuel cell device, water electrolysis/fuel cell operating method, and water electrolysis/fuel cell system - Google Patents

Description

The present invention relates to a water electrolysis device , a water electrolysis method , a water electrolysis system using a solid polymer type water electrolysis cell, and a water electrolysis/fuel cell device using a solid polymer type water electrolysis fuel cell integrated cell. , relates to a water electrolysis/fuel cell operating method and a water electrolysis/fuel cell system.

Conventionally, a plurality of solid polymer type water electrolysis cells in which a power supply body is arranged on both sides of an electrolyte membrane and a separator is further arranged on the outside of each cell are stacked and used as a water electrolysis device (Patent Document 1). .

To explain in more detail, the technology of Patent Document 1 aims to perform water electrolysis treatment by uniformly and reliably supplying raw water to the entire water flow path by evenly distributing raw water for water electrolysis to the water flow path. Therefore, the water electrolysis cells have a structure in which they are arranged horizontally and stacked vertically. Specifically, a plurality of inlet connection channels are provided that communicate the water supply communication hole and the water flow path, and the water supply communication hole is connected to the inner wall surface of the communication hole through which the plurality of inlet connection channels open and the water supply communication hole. The outer wall surface of the communication hole opposite to the inner wall surface of the communication hole has an elongated opening cross-section having an oval shape.

As a result, the raw water is evenly branched from the oval-shaped water supply communication hole to a plurality of inlet connecting channels, and then supplied to the water flow channel, and in the water flow channel, especially in the center near the water supply communication hole. The side was designed to prevent water from flowing preferentially. As a result, the occurrence of variations in pressure loss within the water flow path is suppressed, and water is evenly distributed throughout the water flow path.

Japanese Patent Application Publication No. 2011-127209

However, although the above-mentioned conventional technology aims to perform water electrolysis treatment by uniformly and reliably supplying the raw material water to the entire water flow path by distributing the raw water for water electrolysis evenly to the water flow path, There is no particular suggestion about pressure loss based on the length of the flow path, and in order to flow a large amount of raw water to each water electrolysis cell, it is necessary to separately increase the pressure of the pump that supplies raw water. was there.

The present invention has been made in view of this point, and aims to perform suitable water electrolysis treatment by flowing a large amount of raw material water for water electrolysis into the reaction region of a cell while suppressing the power of the pump.

In order to achieve the above object, the present invention provides a water electrolysis device in which a plurality of solid polymer water electrolysis cells are stacked, each of which has power feeders arranged on both sides of an electrolyte membrane and a separator placed outside each power feeder. The solid polymer type water electrolysis cells are rectangular, and the water electrolysis cells are arranged horizontally and vertically, and are stacked horizontally. A communication port for water supply is arranged along the long side of the side, and a communication port for discharging electrolyzed water and oxygen gas is arranged along the upper long side of each water electrolysis cell . The communication port for discharging electrolyzed water and oxygen gas is characterized in that it is formed over the entire length of the electrode portion of the water electrolysis cell .

The present invention according to another aspect is a method of electrolyzing water using the water electrolysis device described above, in which the raw material is It is characterized by supplying water into the water electrolysis cell .

According to still another aspect, the present invention is a water electrolysis system using the above-described water electrolysis device, in which the water electrolysis device is directly connected to a power supply on both sides of the electrolyte membrane. ) a power supply device that supplies DC power, a raw water supply path that supplies raw water to the water electrolysis device, a hydrogen gas discharge path that discharges hydrogen gas generated in the water electrolysis device outside the system, and a water electrolysis device that supplies raw water to the water electrolysis device; It is characterized by having an oxygen gas release path that releases oxygen gas generated in the electrolyzer to the outside of the system.

Furthermore, in view of the characteristics of the water electrolysis device , water electrolysis method , and water electrolysis cell employed in the water electrolysis system described above, the following invention can be further proposed.

First, water electrolysis is performed by stacking multiple solid polymer type water electrolysis fuel cell integrated cells, in which feeders and current collectors are placed on both sides of an electrolyte membrane, and separators are placed outside of each feeder and current collector. - In the fuel cell device , the solid polymer type water electrolysis fuel cell integrated cell is rectangular, and the water electrolysis fuel cell integrated cell is arranged horizontally and vertically, and is arranged horizontally. Along the lower long side of each rectangular water electrolysis fuel cell integrated cell , there are communication ports for supplying raw water during water electrolysis operation and for supplying cooling water. A communication port is arranged along the upper long side of each water electrolysis fuel cell integrated cell, and a communication port for discharging electrolyzed water and oxygen gas during water electrolysis operation is arranged. A communication port for hydrogen gas discharge during water electrolysis operation, a communication port for hydrogen gas supply during fuel cell operation, and a communication port for air or oxygen gas supply are formed on the short side of the integrated cell. A water electrolysis/fuel cell device characterized by:

According to another aspect , there is a method of switching between water electrolysis operation and fuel cell operation using the water electrolysis/fuel cell device described above, in which the rectangular water electrolysis fuel cell Raw water is supplied into the water electrolysis fuel cell integrated cell from the lower long side of the integrated cell toward the upper long side, and during fuel cell operation, the rectangular water electrolysis fuel cell A water electrolysis/fuel cell operating method can be proposed, which is characterized in that raw material gas is supplied into the water electrolysis fuel cell integrated cell from the short side of the integrated cell toward the opposite short side.

For example, the following water electrolysis/fuel cell system using the water electrolysis/fuel cell device described above can be proposed. That is, a power supply device that supplies DC power to the water electrolysis/fuel cell device, a raw water supply path that supplies raw water to the water electrolysis/fuel cell device, and hydrogen gas generated in the water electrolysis/fuel cell device. a hydrogen gas release path that releases oxygen gas to the outside of the system, an oxygen gas release path that releases oxygen gas generated in the water electrolysis/fuel cell device to the outside of the system, and a hydrogen gas release path that releases hydrogen gas to the water electrolysis/fuel cell device. It has a gas supply path, a gas supply path that supplies oxygen gas or air to the water electrolysis/fuel cell device, and an oxygen gas discharge path that releases water generated in the water electrolysis/fuel cell device to the outside of the system. This is a water electrolysis/fuel cell system that is characterized by :

According to the present invention, it is possible to flow a large amount of raw water into the reaction region of the cell while suppressing the power of the pump that supplies the raw water, and it is possible to perform suitable water electrolysis treatment.

FIG. 1 is an explanatory diagram schematically showing a system of a water electrolysis system incorporating a water electrolysis cell stack according to an embodiment. FIG. 2 is an exploded perspective view of a water electrolysis cell used in a water electrolysis cell stack according to an embodiment. FIG. 2 is a front view of the oxygen electrode side separator showing the state of fluid flowing on the oxygen electrode side separator in the water electrolysis cell stack according to the embodiment. FIG. 3 is a front view of the hydrogen electrode side separator showing the state of fluid flowing on the hydrogen electrode side separator in the water electrolysis cell stack according to the embodiment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a system of a water electrolysis/fuel cell system incorporating a stack of water electrolysis/fuel cells according to an embodiment. FIG. 2 is an exploded perspective view showing how fluid flows during water electrolysis operation in the solid polymer integrated cell used in the water electrolysis/fuel cell stack according to the embodiment. FIG. 2 is an exploded perspective view showing how fluid flows during fuel cell operation in the solid polymer integrated cell used in the water electrolysis/fuel cell stack according to the embodiment. It is a graph which shows the magnification of the flow path pressure loss with respect to the aspect ratio of an electrode. In a separator in a solid polymer type integrated cell, the communication port through which air and reaction product water are discharged is set to be located below the bottom of the electrode surface and the top of the lower side of the sealing material. It is an explanatory view of the front side showing a state where

To explain the embodiment of the present invention, FIG. 1 shows an outline of the configuration of a water electrolysis system 1 according to the embodiment. As a water electrolysis device constructed by connecting and stacking a plurality of electrolytic cells (unit cells) 10 vertically in a horizontal direction and sandwiching them between end plates 11 and 12 from both sides. It has a water electrolysis cell stack 13 of.

As shown in FIG. 2, the water electrolysis cell 10 includes an electrode body 21 having a configuration in which an electrolyte membrane is sandwiched between current collectors from both sides, a separator 31 on the hydrogen electrode side that sandwiches this electrode body 21 from both sides, and an oxygen It has a separator 41 on the pole side.

The electrode body 21, the separator 31 on the hydrogen electrode side, and the separator 41 on the oxygen electrode side each have an electrode portion 22 and regions 32 and 42 corresponding to the electrode portion 22 in the center. Communication ports 23, 24, 33, 34, 43, and 44 are formed above and below the outside of the electrode portion 22 and regions 32 and 42, respectively. These communication ports 23, 24, 33, 34, 43, and 44 function as a manifold for electrolyzed water and oxygen gas generated by water electrolysis. The horizontal lengths of the communication ports 23, 24, 33, 34, 43, and 44 are set to be the same length as the electrode portions 22 and the regions 32 and 42.

Further, in the electrode body 21, the separator 31 on the hydrogen electrode side, and the separator 41 on the oxygen electrode side, the central electrode portion 22 and the lower side of the outside of the regions 32 and 42 corresponding to the electrode portions 22 (in this embodiment, 2) are formed with vertically long communication ports 25, 35, and 45, respectively, which function as manifolds for hydrogen gas generated during water electrolysis.

Regarding the separator 31 on the hydrogen electrode side, sealing materials 36 and 37 (indicated by broken lines) are arranged on the outer periphery of the back side of the communication ports 33 and 34 so as to independently surround the communication ports 33 and 34, respectively. There is. Further, a sealing material 38 (indicated by a broken line) is arranged so as to surround the back surface of the central region 32 and the back surface of the communication port 35 together. Regarding the separator 41 on the oxygen electrode side, a sealing material 46 is arranged so as to surround the central region 42 and the communication ports 43 and 44 together, and a sealing material 47 is arranged so as to independently surround only the communication port 45. It is provided on the outer periphery of the communication port 45. These sealing materials 36 to 38, 46, and 47 prevent each fluid from flowing out other than the predetermined paths.

Furthermore, in this embodiment, at least the central regions 32 and 42, which serve as reaction channels, in the separator 31 on the hydrogen electrode side and the separator 41 on the oxygen electrode side are configured with a general straight channel or a serpentine channel. Unlike conventional materials, materials such as embossed plates, meshes, and punched metals are used that have many irregularities formed on their surfaces. As a result, flow paths are formed in the separator 31 on the hydrogen electrode side and the separator 41 on the oxygen electrode side, allowing fluid to flow in both the vertical and horizontal directions.

As described above, a plurality of water electrolysis cells (unit cells) 10 according to the above configuration are erected in the vertical direction, and as shown in FIG. A water electrolysis cell stack 13 is constructed by connecting and stacking the cells in series and sandwiching them between end plates 11 and 12 from both sides.

Next, returning to FIG. 1, a water electrolysis system 1 employing this water electrolysis cell stack 13 will be described. For example, pure water, which serves as raw water, is supplied to the pure water inlet port P1 of the water electrolysis cell stack 13. Specifically, raw water (pure water) is supplied from a tank 51 having a gas-liquid separation function on the oxygen side to the pure water inlet port P1, which is the raw water inlet of the water electrolysis cell stack 13, and the water is Electrolytic operation is performed.

More specifically, a pipe 52 is connected between the bottom of the tank 51 and the pure water inlet port P1 of the water electrolysis cell stack 13. A pump 53 provided in the piping 52 supplies pure water as raw water from the tank 51 to the pure water inlet port P1 of the water electrolysis cell stack 13. The piping 52 is provided with a check valve 54 on the downstream side of the pump 53, and further downstream thereof is provided with a pressure gauge 55 for measuring the pressure inside the piping 52. The pure water inlet port P1 communicates with the communication ports 24, 34, and 44 shown in FIG. 2, which have been described above in each of the water electrolysis cells 10.

A return pipe 56 for returning part of the water flowing in the pipe 52 to the tank 51 is connected to the pipe 52 on the downstream side of the pump 53, and this return pipe 56 includes a flow rate regulating valve V1, a heat An exchanger 57, an ion exchange resin column 58, and a filter 59 are provided, and the quality of the water in the tank 51 is maintained by treating the returned water through these devices. Note that a liquid level sensor 51a is provided in the tank 51 to detect the water level in the tank. Further, the tank 51 is appropriately replenished with pure water, which becomes raw water, from an external pure water supply source (not shown) through a pipe 60 based on a signal from the liquid level sensor 51a. Further, the oxygen gas remaining in the gas layer within the tank 51 is released to the outside or to an external consumer through the piping 63.

The raw water supplied to the water electrolysis cell stack 13 from the pure water inlet port P1 through the piping 52 is electrolyzed in the water electrolysis cell stack 13, and oxygen and the water accompanying the oxygen are converted into pure water which becomes the outlet on the oxygen side. The liquid is returned to the tank 51 from the outlet port P2 through the piping 61, and is separated into gas and liquid within the tank 51. The piping 61 is provided with a pressure gauge 62 that measures the pressure inside the piping 61 and a solenoid valve V2. The pure water outlet port P2 communicates with the communication ports 23, 33, and 43 shown in FIG. 2, which have been described above in each of the water electrolysis cells 10.

A pipe 71 is connected to a hydrogen outlet port P3 serving as a hydrogen side exit of the water electrolysis cell stack 13, and this pipe 71 communicates with a tank 72 having a gas-liquid separation function on the hydrogen side. The hydrogen outlet port P3 communicates with the communication ports 25, 35, and 45 shown in FIG. 2 described above in each of the water electrolysis cells 10.

There is a space between the tank 72 and the air layer part of the tank 51 (the part above the level of the water stored in the tank, and the part where the liquid level does not reach even if the level of the stored water rises). , and piping 73 are connected. The piping 73 is provided with a solenoid valve V3 and a valve V4. A liquid level sensor 72a is provided within the tank 72 to detect the level of water within the tank.

As described above, hydrogen generated by water electrolysis is sent to the tank 72 through the piping 71 along with associated water, and is separated into gas and liquid within the tank 72. The hydrogen gas separated into gas and liquid in the tank 72 is sent to the demand side or a hydrogen storage tank (high-pressure container, not shown) through a pipe 74, for example. A back pressure valve V5 is provided in the pipe 74, a discharge pipe 75 is connected to the upstream side of the back pressure valve V5 in the pipe 74, and a solenoid valve V6 is provided in the discharge pipe 75.

A DC power supply 2 is connected to the water electrolysis cell stack 13, and pure water for electrolysis supplied from the pure water inlet port P1 is electrolyzed into hydrogen ions and oxygen ions according to its output. Of these, oxygen ions become oxygen molecules on the catalyst in the water electrolysis cell 10, and as described above, are discharged from the cell from the pure water outlet port P2 together with the pure water, while the hydrogen ions generated by electrolysis release the accompanying water. Accordingly, it moves to the hydrogen side in the water electrolysis cell 10, becomes hydrogen molecules on the hydrogen side catalyst, and is discharged from the hydrogen outlet port P3 to the outside of the cell.

According to the water electrolysis system 1 having the above configuration, pure water supplied from the pure water inlet port P1 to each water electrolysis cell 10 of the water electrolysis cell stack 13 by electric power from the DC power supply 2 is supplied to each water electrolysis cell 10 of the water electrolysis cell stack 13. At 10, water is electrolyzed, and oxygen molecules are discharged from the pure water outlet port P2 together with pure water. At this time, as shown in FIG. 3, the separator 41 on the oxygen electrode side Then, pure water, which is raw water, flows from the lower communication port 44 communicating with the pure water inlet port P1 to the upper communication port 43 communicating with the pure water outlet port P2. On the other hand, in the separator 31 on the hydrogen electrode side, as shown in FIG. 4, the generated hydrogen gas flows obliquely toward the communication port 35 in the central region 32 (arrow in the figure).

Here, the main requirements for the reaction flow path of the water electrolysis cell 10 are that the reaction flow path pressure drop of the oxygen electrode is low from the viewpoint of reducing the power of the pump 53 and reducing the pressure difference downstream of the flow path, and Supplying pure water to the surface, ensuring the cooling function of the cell, and preventing water drying downstream due to an increase in void ratio (ratio of air bubbles in pure water) It is possible to secure a sufficient flow rate.

In light of this point, if we look at the flow of the reaction fluid in the separator 41 on the oxygen electrode side shown in FIG. (arrow in the figure), oxygen molecules generated in the central region 42 corresponding to the electrode portion 22 are transferred to the purified water from the upper communication port 43 along with the electrolyzed water that has not been electrolyzed (pure water that has been subjected to water electrolysis). It flows to exit port P2. Therefore, considering the same reaction area, as shown in the embodiment, the region 42 and the separator 41 are horizontally long rectangles, and the communication port 44 serving as the pure water supply port is located on the long side. Since the supply ports are arranged along the longitudinal direction and extend in the longitudinal direction, the length of the communication port 44 can be ensured long, and a large amount of pure water, which is raw water, can flow into the region 42. Moreover, since the length of the flow path is in the short side direction, the pressure loss in the reaction flow path when flowing through the regions 32 and 42 corresponding to the electrode portions 22 is also suppressed to a low level.

On the other hand, in this water electrolysis cell 10, the supplied electrolyzed water also plays the role of cooling the cell, so being able to increase the flow rate of supplied pure water is also advantageous for cooling the cell. If the flow rate of electrolyzed water is low, the heat generated during the reaction cannot be removed sufficiently, and there is a risk of abnormal overheating and damage to the cell. Furthermore, if cooling is insufficient, a large temperature change may occur upstream and downstream of the water electrolysis cell 10, but according to the water electrolysis cell 10 of the embodiment, the flow rate of supplied pure water can be increased, and the flow rate can be increased. Since the path length is short, such situations can be suppressed.

In addition, in the water electrolysis cell 10 of the embodiment, in order to simplify the system, only one communication port 25, 35, 45 is provided for discharging hydrogen gas. If desired, an appropriate number of communication ports communicating with the hydrogen outlet port P3 may be provided on both sides of the electrode portion 22 and the regions 32 and 42.

In addition, the vertical position of the communication port for hydrogen gas discharge may be made vertically on the entire surface so as to completely cover the electrode surface from the lower part to the upper part (i.e., approximately corresponding to the short sides of the separators 31 and 41). (You may also set the length). However, in that case, a large amount of hydrogen will remain in the communication port portion during operation, and the amount of hydrogen gas in the water electrolysis cell stack 13 will increase. Therefore, from the viewpoint of safety, it is better to reduce the size of the communication port 35 for discharging hydrogen gas to reduce the amount of hydrogen remaining in the water electrolysis cell stack 13.

As for how to arrange it, for example, the communication port 35 is provided only in the lower part of the electrode surface, and the external piping 71 leading to the communication port 35 is provided at a position lower than the lower end of the electrode surface 22, and from the oxygen electrode side. The coordinated water may be drained smoothly. In addition, in order to ensure the wet state of the electrolyte membrane as much as possible, the communication port 35 is provided in the upper part of the electrode surface 22, and the external piping 71 is provided at a position higher than the upper end of the electrode surface 22, so that the electrode surface 22 is submerged in water. You can do it like this.

The above is an example of the water electrolysis system 1 using the solid polymer type water electrolysis cell 10, but a solid polymer type integrated type that integrates the solid polymer type water electrolysis cell and the fuel cell Cells (also referred to as water electrolysis fuel cell integrated cells, integrated cells, and reversible cells) have hitherto had the following problems.

That is, a solid polymer integrated cell is an energy converter that integrates a solid polymer water electrolysis cell and a fuel cell to selectively perform the functions of both in one cell. As described above, in the water electrolysis cell, pure water is supplied to the reaction channel of the oxygen generating electrode, and the pure water is electrolyzed by supplying electric power from the outside. Oxygen is generated at the oxygen generating electrode and hydrogen is generated at the hydrogen generating electrode, which are separated by a solid polymer diaphragm. The generated hydrogen is discharged to the outside of the cell through the reaction flow path of the hydrogen generation electrode, and is stored in a storage container as needed or directly supplied to hydrogen demand. At this time, not all of the pure water supplied to the reaction flow path of the oxygen generating electrode is decomposed into hydrogen and oxygen, and the undecomposed pure water passes through the reaction flow path together with the generated oxygen to the cell. It is discharged outside.

On the other hand, in a fuel cell, hydrogen is introduced into the reaction flow path of the hydrogen electrode (hydrogen generating electrode of a water electrolysis cell; hereinafter sometimes referred to as a "hydrogen electrode"), and the oxygen electrode (oxygen generating electrode of a water electrolysis cell; hereinafter referred to as "hydrogen electrode") Oxygen-containing gas such as air or oxygen is supplied in a humidified state as necessary to the reaction flow path of the ``oxygen electrode'' (sometimes referred to as an ``oxygen electrode''), and electricity is generated by connecting an external load.

Along with such power generation, water is generated at the oxygen electrode and is discharged to the outside of the cell through the reaction flow path along with air and oxygen that are not used in the reaction. On the hydrogen electrode side as well, water generated within the cell is discharged to the outside of the cell through the reaction channel along with hydrogen not used in the reaction.

Ordinary water electrolysis cells and fuel cells, like the water electrolysis cells mentioned above, have the shape of a stack of multiple unit cells. When the reaction fluid is discharged to the outside of the cell, it is discharged through a communication port that functions as a manifold that connects the outside of the cell and the reaction flow path. Conventionally, this communication port is common to each pole of the water electrolysis cell and the fuel cell (for example, Japanese Patent Laid-Open No. 2006-127807).

Here, the main requirements for the reaction flow path of a water electrolysis cell are, as mentioned earlier, low pressure drop in the reaction flow path of the oxygen electrode from the viewpoint of reducing pump power and pressure difference downstream of the flow path. In addition, the flow rate of supplied pure water can be increased from the viewpoint of sufficiently supplying pure water to the electrode surface, ensuring the cooling function of the cell, and preventing water drying downstream of the flow path by increasing the void ratio. On the other hand, the main requirements for the reaction flow path of a fuel cell are to improve the diffusion of oxygen to the electrode surface and to prevent the reaction flow path from being blocked by generated water. The goal is to increase the flow rate.

In this case, in order to ensure the requirements required for the oxygen electrode reaction channel of the water electrolysis cell, it is necessary to increase the flow channel cross-sectional area, but it is necessary to ensure the requirements required for the oxygen electrode reaction channel of the fuel cell cell. Therefore, it is necessary to reduce the cross-sectional area of the flow path. Further, the density of pure water supplied to the oxygen electrode of a water electrolysis cell and the humidified air (oxygen) supplied to the oxygen electrode of a fuel cell is about 1,000 times different. Therefore, if pure water and humidified air were to flow at the same flow rate, the pressure loss caused by flowing water would be overwhelmingly greater. In other words, there are contradictory requirements required for both reaction channels, especially the reaction channel of the oxygen electrode, and it is important how to satisfy these requirements.

In this regard, in the past, reaction channels were designed to suit the more important function of water electrolysis and fuel cells, or were designed at a midpoint between the needs of both. Therefore, a reaction channel design that is optimal for both has not been made.

In view of this, the oxygen electrode communication port (functioning as a manifold) that has been commonly used in water electrolysis cells and fuel cells will be replaced with the oxygen electrode communication port (functioning as a manifold) of the water electrolysis cell. An embodiment will be described in which a communication port (functioning as a manifold) for the oxygen electrode of the fuel cell and the oxygen electrode of the fuel cell are respectively provided to solve such problems.

FIG. 5 schematically shows the configuration of a water electrolysis/fuel cell system 101 according to an embodiment. In this water electrolysis/fuel cell system 101, the solid polymer integrated cell (unit A water electrolysis/fuel cell constructed by connecting and stacking a plurality of cells in series in the horizontal direction and sandwiching them between end plates 111 and 112 from both sides, with the cells 110 standing upright in the vertical direction. has a stack 113

FIG. 6 shows an integrated cell 110 in which a water electrolysis cell and a fuel cell according to an embodiment are integrated. Note that FIG. 6 also shows the flow of fluid when the flow of fluid during water electrolysis operation will be explained later.

The integrated cell 110 includes an electrode body 121 having a structure in which an electrolyte membrane is sandwiched between supply and current collectors from both sides, a separator 131 on the hydrogen electrode side and a separator 141 on the oxygen electrode side, which sandwich this electrode body 121 from both sides. have.

The electrode body 121, the separator 131 on the hydrogen electrode side, and the separator 141 on the oxygen electrode side have various connections described below on the central electrode portion 122, the back side of the area 132 corresponding to this electrode portion 122, and the outside of the region 142, respectively. It has a mouth.

First, on both sides of the rectangular electrode body 121, the electrode part 122 in the hydrogen electrode side separator 131, the electrode part 122 in the oxygen electrode side separator 141, and the regions 132 and 142 corresponding to the electrode parts 122, hydrogen electrode communication ports 123a and 123b are provided. , 133a, 133b, 143a, and 143b are provided. Similarly, on both sides of the rectangular electrode body 121, the electrode part 122 of the hydrogen electrode side separator 131, the electrode part 122 of the oxygen electrode side separator 141, and the regions 132 and 142 corresponding to the electrode parts, oxygen electrodes for fuel cells are provided. Communication ports 124a, 124b, 134a, 134b, 144a, and 144b are provided.

On the other hand, below the electrode portion 122 of the rectangular electrode body 121, the separator 131 on the hydrogen electrode side, the separator 141 on the oxygen electrode side, and the outside of the regions 132 and 142 corresponding to the electrode portion 122, there are cooling water communication ports 125a, respectively. , oxygen electrode communication port 126a, cooling water communication port 135a, oxygen electrode communication port 136a, cooling water communication port 145a, and oxygen electrode communication port 146a are provided alternately. Further, above the electrode portion 122 and the outside of regions 132 and 142 corresponding to the electrode portion 122 in the electrode body 121, the separator 131 on the hydrogen electrode side, and the separator 141 on the oxygen electrode side, there is an oxygen electrode communication port 126b, a cooling water The oxygen electrode communication port 125b, the oxygen electrode communication port 136b, the cooling water communication port 135b, the oxygen electrode communication port 146b, and the cooling water communication port 145b are provided alternately.

A sealing material is arranged around each communication port of the separator 131 on the hydrogen electrode side and the separator 141 on the oxygen electrode side, as described below. First, regarding the separator 131 on the hydrogen electrode side, a sealing material 137 (indicated by a broken line) is arranged around the outer periphery of the oxygen electrode communication ports 134a and 134b to independently surround each communication port. Furthermore, a sealing material 138 (indicated by broken lines) is arranged around the hydrogen electrode communication ports 133a, 133b and the central region 132 to integrally surround them. Seal members 139 (indicated by broken lines) are arranged around the outer peripheries of the cooling water communication ports 135a, 135b and the oxygen electrode communication ports 136a, 136b, respectively, to independently surround them.

On the other hand, regarding the separator 141 on the oxygen electrode side, a sealing material 147 is arranged around the oxygen electrode communication ports 143a and 143b for the fuel cell to independently surround each communication port. Further, sealing materials 148 are arranged around the cooling water communication ports 145a and 145b to independently surround each communication port. As for the remaining oxygen electrode communication ports 146a, 146b and the central region 142, a sealing material 149 is arranged to integrally surround them.

These sealing materials 137 to 139 and 147 to 149 prevent each fluid from flowing to a path other than the predetermined path. Furthermore, in this embodiment, at least the central regions 132 and 142, which serve as reaction channels, in the separator 131 on the hydrogen electrode side and the separator 141 on the oxygen electrode side are configured with a general straight channel or a serpentine channel. Unlike other materials, materials such as embossed, mesh, and punched metal are used. As a result, a flow path is formed in the separator 131 on the hydrogen electrode side and the separator 141 on the oxygen electrode side, allowing fluid to flow in both the vertical and horizontal directions.

Next, returning to FIG. 5, the water electrolysis/fuel cell system 101 employing the water electrolysis/fuel cell stack 113 in which the integrated cells 110 are stacked will be described. In FIG. 5, the configurations of members, devices, etc. identified by the same symbols as those used in the explanation in FIG. 1 indicate the same components, devices, etc. as in the water electrolysis system 1 of FIG. Therefore, duplicate explanations will be omitted.

As mentioned above, the integrated cell 110 adopted in this water electrolysis/fuel cell system 101 has many types of communication ports that function as manifolds, so a stack of water electrolysis/fuel cell cells communicating with each communication port is used. The number of ports provided in 113 is also increasing. That is, first, the pure water inlet port P1 communicates with the oxygen electrode communication ports 126a, 136a, and 146a, the pure water outlet port P2 communicates with the oxygen electrode communication ports 126b, 136b, and 146b, and the hydrogen outlet port P3 communicates with the oxygen electrode communication ports 126a, 136a, and 146a. It communicates with communication ports 123b, 133b, and 143b. Since the water electrolysis/fuel cell system 101 is capable of fuel cell operation, a hydrogen inlet port P4 is newly provided to serve as an inlet for hydrogen gas serving as a raw material gas.

Hydrogen inlet port P4 communicates with hydrogen electrode communication ports 123a, 133a, and 143a. Further, an air inlet port P5 communicating with the oxygen electrode communication ports 124a, 134a, 144a for fuel cells is provided, and an air outlet port P6 communicating with the oxygen electrode communication ports 124b, 134b, 144b for fuel cells is provided. . Furthermore, a cooling water outlet port P7 that communicates with the cooling water communication ports 125a, 135a, and 145a, and a cooling water inlet port P8 that communicates with the cooling water communication ports 125b, 135b, and 145b are newly provided.

A flow path 151 is connected to the hydrogen inlet port P4, and hydrogen gas from a hydrogen gas supply source (not shown) can be introduced into the hydrogen inlet port P4. The flow path 151 is provided with a regulating valve V7, a solenoid valve V8, and a pressure gauge 152. A flow path 153 communicating with the air layer portion of the tank 72 is connected to the flow path 151 on the downstream side of the solenoid valve V8. A hydrogen pump 154 is provided in the flow path 153 .

A flow path 163 through which air supplied by a blower 161 is introduced via a humidity exchanger 162 is connected to the air inlet port P5. A check valve 164 is provided in the flow path 163. A flow path 165 is connected to the air outlet port P6, and the air coming out of the water electrolysis/fuel cell stack 113 is discharged to the outside through a humidity exchanger 162. The flow path 165 is provided with a solenoid valve V9.

A piping 181 is connected to the cooling water outlet port P7, and the heated cooling water is sent to a heat exchanger 183 by a hydrogen pump 182, where it exchanges heat with cooling water from the outside and cools down, and then is sent to the piping. 184, the cooling water is introduced into the stack 113 of the water electrolysis/fuel cell from the cooling water inlet port P8. Note that the water source for the cooling water may be, for example, city water such as tap water, underground water, or the like. Moreover, the cooling water whose temperature has been raised after the heat exchange may be appropriately supplied to a destination that requires heat.

In addition to the DC power supply 2, a power load 3, which is a power demand destination, is connected to the water electrolysis/fuel cell stack 113.

The water electrolysis/fuel cell system 101 is configured as described above, and the operating method thereof will be explained next.

[Water electrolysis operation]
First, the solenoid valve V2 is opened, and the other solenoid valves V3, V6, V8, and V9 are closed. The pure water stored in the tank 51 is supplied to the pure water inlet port P1 of the water electrolysis/fuel cell stack 113 through the pipe 52 by starting the pump 53. The pure water inlet port P1 communicates with the oxygen electrode communication ports 126a, 136a, and 146a, and as shown in FIG. It passes through the region 142, passes through the oxygen electrode communication ports 126b, 136b, and 146b, is discharged from the pure water outlet port P2 to the outside of the water electrolysis/fuel cell stack 113, and is returned to the tank 51 from the piping 61. .

When DC power is supplied from the DC power supply 2 to the water electrolysis/fuel cell stack 113 in this state, protons (H ⁺ ) and oxygen are generated on the oxygen electrode. The generated protons (H ⁺ ) move in the electrode body 121 from the oxygen electrode to the hydrogen electrode with coordinated water, and as shown in FIG. 133b, and is discharged to the outside of the water electrolysis/fuel cell stack 113 from the hydrogen outlet port P3. In the tank 72, the gas-liquid separated hydrogen gas is sent to the back pressure valve V5 through the pipe 71, where the pressure is adjusted, and then sent to a hydrogen demand outside the system or a hydrogen storage tank (not shown). It will be done.

The pure water separated in the tank 72 is sent to the tank 51 through a pipe 73 using the pressure difference between the hydrogen side and the oxygen side. Existing known technology may be used to send the pure water from the tank 72 to the tank 51.

On the other hand, oxygen generated in the stack 113 of the water electrolysis/fuel cell, along with undecomposed pure water, passes through the communication ports 126b, 136b, and 146b to the pure water outlet port P2, and passes through the piping 61 to the tank 51. The water is returned to The oxygen gas separated into gas and liquid in the tank 51 is discharged to the outside of the system through a pipe 63. Note that if oxygen gas is required, an oxygen storage tank (not shown) may be separately provided and the oxygen gas may be sent to the oxygen storage tank. The purified water separated in the tank 51 is again supplied to the water electrolysis/fuel cell stack 113 as pure water for electrolysis.

As described above, the pipes 181 and 184 are cooling water systems, and play a role in removing heat generated due to electrolysis. The removed heat may be supplied to heat demand via the heat exchanger 183, as described above. However, in the case of water electrolysis operation, cooling can be performed using electrolyzed water (pure water) for electrolysis, so the cooling water does not need to be circulated.

[Fuel cell operation]
Next, the case of fuel cell operation will be explained. During fuel cell operation, the solenoid valves V8 and V9 are opened, and the other solenoid valves V2, V3, and V6 are closed. On the hydrogen side, hydrogen whose pressure is regulated by the regulating valve V7 is supplied to the hydrogen inlet port P4 through the flow path 151. As shown in FIG. 7, the hydrogen supplied to the hydrogen inlet port P4 passes through the communication port 123a, the central electrode portion 122, and the hydrogen electrode communication port 123b, and is discharged to the outside of the cell from the hydrogen outlet port P3. By starting the hydrogen pump 154, the discharged hydrogen gas is sucked into the hydrogen pump 154 and is again supplied to the water electrolysis/fuel cell stack 113.

On the other hand, on the oxygen side, air is sucked in from the atmosphere by starting the blower 161, humidified as appropriate by the humidity exchanger 162, and then passed through piping 163 from the air inlet port P5 to the stack of water electrolysis/fuel cells. 113. Since the air inlet port P5 communicates with the oxygen electrode communication port 144a, the water electrolysis/fuel cell stack 113 passes from the oxygen electrode communication port 144a through the central region 142 and from the communication port 144b, and from the air outlet port P6. is discharged outside. The air is then exhausted to the atmosphere through piping 165 and humidity exchanger 162. When the connection with the external power load 3 is turned on in this state, hydrogen is decomposed into protons on the hydrogen electrode, and protons and oxygen combine on the oxygen electrode to generate water and electricity. The generated electricity will be supplied to the power load 3.

Hydrogen gas that is not used in the reaction during fuel cell operation is discharged from the hydrogen outlet port P3 to the outside of the water electrolysis/fuel cell stack 113 through the hydrogen electrode communication port 123b, and then passes through the pipe 71 to the tank 72. supplied to The hydrogen gas separated into gas and liquid in the tank 72 is supplied again to the water electrolysis/fuel cell stack 113 by the hydrogen pump 154. The amount of hydrogen consumed in the reaction is appropriately supplied from the outside at a constant pressure by the function of the regulating valve V7.

On the other hand, the air not used in the reaction and the water produced by the reaction pass through the communication port 144b and are discharged to the outside of the water electrolysis/fuel cell stack 113 from the air outlet port P6. Then, it is sent to the humidity exchanger 162 via piping 165. In the humidity exchanger 162, the air sent from the blower 161 is humidified and then exhausted to the outside of the system through piping 165. Therefore, even if the air is of low humidity, the air sent from the blower 161 is sufficiently humidified by the humidity exchanger 162 before being supplied to the water electrolysis/fuel cell stack 113. Note that when performing fuel cell operation, circulation of cooling water in the cooling water system constituted by the pipes 181 and 184 is essential.

Note that when switching the operation from water electrolysis operation to fuel cell operation, the power supply from the DC power supply 2 is first stopped. Next, on the hydrogen side, the solenoid valve V6 is opened, and the pressure of the entire hydrogen system is released to the outside, thereby reducing the pressure in the system to near normal pressure. On the oxygen side, the pump 53 is stopped, the solenoid valve V2 is closed, and the solenoid valve V9 is opened, and then the blower 161 is started to communicate the pure water remaining in and around the electrode part 122 of the electrode body 121. The air is discharged from the port 144b to the outside of the water electrolysis/fuel cell stack 113 via the air outlet port P6. For the subsequent method of drying the interior of the water electrolysis/fuel cell stack 113, conventional techniques may be applied as appropriate.

Further, when switching the operation from fuel cell operation to water electrolysis operation, first the connection with the electric power load 3 is disconnected. Next, on the hydrogen side, after stopping the hydrogen pump 154, the solenoid valve V8 is closed. On the oxygen side, the solenoid valve V9 is closed after the blower 161 is stopped. After that, water electrolysis operation can be started as usual.

Regarding water electrolysis operation and fuel cell operation as described above, in the case of conventional integrated cells, as mentioned above, the communication port of the oxygen electrode is commonly used during water electrolysis operation and fuel cell operation. The flow path cross-sectional area and flow path length when flowing the reaction fluid during water electrolysis operation and during fuel cell operation were the same in both operation modes. Therefore, as mentioned above, it has been impossible to satisfy the requirements for both reaction channels.

On the other hand, in the example using the integrated cell 110 according to the embodiment, it is possible to significantly change the flow path cross-sectional area and the flow path length between water electrolysis operation and fuel cell operation.

That is, during water electrolysis operation, as shown in FIG. 6, if you look at the flow of the reaction fluid in the separator 141 on the oxygen electrode side, the raw material flows from the lower oxygen electrode communication port 146a to the upper oxygen electrode communication port 146b. Pure water flows (arrow in the figure), and oxygen molecules generated in the central region 142 corresponding to the electrode portion 122 are electrolyzed water that has not been electrolyzed (pure water that has been subjected to water electrolysis). At the same time, the water flows from the upper oxygen electrode communication port 146b to the pure water outlet port P2. Therefore, considering the same reaction area, as shown in the embodiment, the region 142 and the separator 141 are horizontally long rectangles, and the oxygen electrode communication port 146a, which serves as the pure water supply port, is Since the supply ports are arranged along the sides and extend in the longitudinal direction, a large number of supply ports can be secured, and a large amount of pure water, which is raw water, can flow into the electrode portion 122 and the region 142. Moreover, since the channel length is in the transverse direction, the pressure loss in the reaction channel is also kept low.

On the other hand, during fuel cell operation, in order to ensure the requirements required for the oxygen electrode reaction flow path, it is necessary to reduce the flow path cross-sectional area. Since it flows from the oxygen electrode communication port 144a located on the side side through the region 142 toward the oxygen electrode communication port 144b located on the opposite short side, the flow path cross-sectional area is as described above. It is smaller than when water flows from the long side to the long side during water electrolysis operation. Similarly, hydrogen gas also flows from the communication port 123a located on the short side toward the hydrogen electrode communication port 123b located on the opposite short side, so the flow path is interrupted at that time. The area is smaller than that during water electrolysis operation.

As described above, the integrated cell 110 according to the embodiment of the present invention replaces the communication port of the oxygen electrode, which was conventionally used in common between water electrolysis cells and fuel cells, with the communication port of the oxygen electrode of the water electrolysis cell. and a communication port for the oxygen electrode of the fuel cell, each of which is provided for exclusive use. Furthermore, since the electrode body 121 and the separators 131 and 141 are rectangular in shape and arranged horizontally in a vertical direction, pure water, which is the raw material water, is oriented in the transverse direction during water electrolysis operation. In fuel cell operation, on the other hand, it is possible to flow humidified air in the longitudinal direction.

As a result, even though the same cell is used, the cross-sectional area of the reaction flow path can be changed significantly between water electrolysis operation and fuel cell operation, and the flow path length, which has a large effect on pressure loss, can also be significantly changed. can be changed to As a result, the requirements required for the reaction flow path of the water electrolysis cell and the requirements required for the fuel cell can be satisfied under more ideal conditions even in the same cell.

In order to quantitatively demonstrate this, we will show below how much the pressure loss and flow rate in the flow path can be changed between the conventional separator and the separator according to the embodiment while keeping the electrode shapes the same.

First, the flow path pressure loss: ΔP is expressed by the following formula.
ΔP=λ・(L/D)・(ρ・v2/2)...Formula (1)
In equation (1), λ is the tube friction coefficient, L is the channel length, D is the channel cross-sectional area, ρ is the fluid density, and v is the flow velocity.

FIG. 8 schematically shows how the channel pressure loss changes when the aspect ratio of the electrode is changed under the condition that the electrode area is fixed constant. The graph in FIG. 8 is the result of evaluation assuming that the value of the pipe friction coefficient is constant. When the aspect ratio of the electrode (short side direction It can be reduced by 16 times. Furthermore, when the aspect ratio of the electrode is set to 1:4, it can be reduced to 1/258 times. Pipe frictional resistance varies depending on the Reynolds number and whether the flow is laminar or turbulent, but the maximum difference is estimated to be about 5 times when the aspect ratio is about 1:4. By simple calculation, it can be reduced to 1/3 times or less when the aspect ratio is 1:2, and to 1/51 times or less when the aspect ratio is 1:4. Here, the density of gas and water is about 1000 times different, but the flow rate of humidified air when actually operating a fuel cell with a conventional integrated cell is about 10 times the flow rate of pure water during water electrolysis. be.

Taking these points into consideration, the difference in channel pressure drop when humidified air is actually flowed through an integrated cell and when pure water is flowed is the difference in channel pressure drop in the transverse direction with respect to the case in which humidified air is flowed in the longitudinal direction. When pure water is flowed through, when the aspect ratio is 1:2, it is 3.3 times or less, and when it is 1:4, it is 1/5 times or less.

If the communication port is shared as before, the difference in flow path pressure drop will be 10 times greater when pure water is flown than when humidified air is flown, regardless of the aspect ratio of the flow path (density of water: 1,000 times the density of humidified air, water flow rate: 1/10 times the density of humidified air), it can be seen that the embodiment of the present invention can dramatically reduce the flow path pressure loss during water electrolysis. . However, during water electrolysis operation, oxygen is generated at the oxygen electrode due to electrolysis, so the flow format of the oxygen electrode reaction flow path is such that oxygen gas increases from a single-phase flow of pure water toward the cell outlet. It becomes a liquid two-phase flow. Since the channel pressure drop in gas-liquid two-phase flow is higher than in the case of single-phase flow, it is necessary to take this point into consideration when determining the aspect ratio of the channel.

Next, we will discuss how the flow velocity v in the flow path changes when the aspect ratio of the electrodes is changed.If the flow rate is fixed at Q, then the only difference is the difference in cross-sectional area A. Therefore, it can be found by simple calculation of v=Q/A. The difference between flowing the flow rate Q in the widthwise direction and flowing it in the lengthwise direction is two times when the aspect ratio is 1:2, and four times when the aspect ratio is 1:4. From an analogy between mass transfer and heat transfer, the mass transfer coefficient increases in proportion to the 0.5th power of the flow velocity when the flow is laminar, and to the 0.8th power of the flow velocity when the flow is turbulent. Therefore, if the flow rate is 4 times higher, the mass transfer rate will be twice that of laminar flow, and three times that of turbulent flow, which will only promote the diffusion of oxygen from the reaction channel to the electrode surface. In addition, the effect of discharging reaction product water also increases.

If oxygen diffusion to the electrode surface is promoted, the fuel cell can be operated at a higher current density (=current value/electrode area) than before, and the output density per unit cell can be improved. Regarding this point as well, if the communication port is shared as before, and the cell is designed so that the flow path pressure loss during water electrolysis is small, the flow rate will be lower if the aspect ratio is set to 1:4. Since it is 1/4 times as large, the mass transfer rate is 1/2 or 1/3 times, which prevents sufficient oxygen diffusion to the electrode surface, and also reduces the effect of discharging reaction product water. As a result, it is only possible to operate at a lower current density.

From the above, it can be seen that the shape of the flow path and separator adopted in the integrated cell 110 according to the embodiment of the present invention makes it possible to reduce the flow path pressure loss during water electrolysis and ensure the flow rate during the fuel cell.

Note that in the electrode body 121 and separators 131, 141 employed in the integrated cell 110 shown in FIGS. 6 and 7, the pure water communication ports 126a, 126b, 136a, 136b, 146a, 146b and the cooling water communication port 125a are provided. , 125b, 135a, 135b, 145a, and 145b are divided into multiple parts. This allows the fluid to be evenly distributed in the reaction channels. In addition to simply dividing into a plurality of parts, the vertically opposing communication ports are provided for alternate purposes, which also makes it possible to distribute the fluid uniformly.

Incidentally, in the embodiment described above, the water electrolysis cell 10 and the integrated cell 110 are both arranged horizontally and vertically, and are stacked horizontally to form the water electrolysis cell stack 13 and the water electrolysis/fuel cell, respectively. However, if these rectangular cells are arranged vertically and raw water, etc. flows from the sides (raw water, etc. flows from the long side), the following will occur. There is a problem. In other words, if a rectangular cell is arranged vertically and raw water, etc. flows from the side, during water electrolysis operation, the pressure difference due to the water head pressure between the top and bottom of the cell will increase (cell (the lower part is under strong pressure). Therefore, it is necessary to design the entire cell so that it can withstand the strong pressure applied to the lower part of the cell. Therefore, it is preferable to install the cell horizontally so that the pressure difference within the cell can be reduced.

Additionally, during fuel cell operation, water generated on both the oxygen and hydrogen sides is drained from the electrode surface (by free fall due to gravity) to the outside of the cell through the manifold, but if a rectangular cell is installed vertically, the gas The gas flow is in the vertical direction, and the gas flow is upward on at least one of the oxygen side and the hydrogen side, which impedes drainage. Also from this point of view, it is preferable that each of the rectangular cells described above be installed horizontally.

By the way, since the integrated cell 110 described above is used in an upright state (a state in which it is arranged horizontally and stands vertically), during fuel cell operation, the lower edge portion of the sealing material 149 shown in FIG. There is a possibility that reaction product water accumulates in the area (indicated by the broken line a in the figure). If reaction product water accumulates in this way and the electrode surface (the part corresponding to the central region 142) becomes submerged, the area of the electrode that can contribute to the reaction decreases, resulting in a drop in power generation efficiency.

In order to cope with this situation, the oxygen electrode communication port 144b through which air and reaction product water are discharged is located at the lowest part of the electrode surface (indicated by the broken line b in the figure) and the lowermost part of the sealing material 149 (indicated by the dotted line b in the figure). In other words, the lower edge of the oxygen electrode communication port 144b (indicated by the dotted line d in the figure) is positioned below the electrode surface shown by the dotted line b. It can be proposed to set the arrangement so that it is located below the bottom and the top of the lower side of the sealing material 149 indicated by the wavy line c.

Thereby, the reaction product water is discharged from the oxygen electrode communication port 144b without reaching the electrode surface and submerging the electrode surface. Therefore, it is possible to prevent the electrode from being submerged in water due to accumulation of reaction product water, and it is possible to prevent the electrode area from decreasing and power generation efficiency from decreasing.

The present invention provides water electrolysis using a solid polymer type water electrolysis cell in which a power supply body is placed on both sides of an electrolyte membrane and a separator is placed on the outside of each cell, and a power supply/current collector is placed on both sides of an electrolyte membrane. Furthermore, it is useful for water electrolysis/fuel cells using solid polymer type water electrolysis fuel cell integrated cells in which a separator is disposed on the outside of each cell.

1 Water electrolysis system 2 DC power supply 3 External load 10 Water electrolysis cell 11, 12 End plate 13 Water electrolysis cell stack 21 Electrode body 22 Electrode part 23, 24, 25, 33, 34, 35, 43, 44, 45 Communication port 31 Separator on the hydrogen electrode side 32, 42 Area 36, 37, 38, 46, 47 Seal material 41 Separator on the oxygen electrode side 51, 72 Tank 52, 59, 74 Piping 53 Pump P1 Pure water inlet port P2 Pure water outlet port P3 Hydrogen Outlet port P4 Hydrogen inlet port P5 Air inlet port P6 Air outlet port P7 Cooling water outlet port P8 Cooling water inlet port 101 Water electrolysis/fuel cell system 101
110 Integrated cell 111, 112 End plate 113 Water electrolysis/fuel cell stack 121 Electrode body 122 Electrode portion 123a, 123b, 133a, 133b, 143a, 143b Hydrogen electrode communication port 124a, 124b, 134a, 134b, 144a, 144b Oxygen electrode communication port 131 Separator on the hydrogen electrode side 132, 142 Region 137, 138, 139, 147, 148, 149 Seal material 141 Separator on the oxygen electrode side 151, 153, 163, 165 Channel 154 Hydrogen pump

Claims (8)

A water electrolysis device in which a plurality of solid polymer water electrolysis cells are stacked, each of which has a power supply body arranged on both sides of an electrolyte membrane and a separator arranged outside each power supply body,
The solid polymer type water electrolysis cells are rectangular, and the water electrolysis cells are arranged horizontally and vertically, and are stacked horizontally,
A communication port for water supply is arranged along the lower long side of each of the rectangular water electrolysis cells,
A communication port for discharging electrolyzed water and oxygen gas is arranged along the upper long side of each water electrolysis cell .
A water electrolysis device , wherein the communication port for discharging the electrolyzed water and oxygen gas is formed over the entire longitudinal direction of the electrode portion of the water electrolysis cell . The water electrolysis device according to claim 1, wherein the communication port for water supply is formed over the entire length of the electrode portion. A method of electrolyzing water using the water electrolysis device according to claim 1 or 2, comprising:
A water electrolysis method characterized in that raw water is supplied into the rectangular water electrolysis cell from the lower long side to the upper long side of the rectangular water electrolysis cell. A water electrolysis system using the water electrolysis device according to claim 1 or 2,
a power supply device that supplies DC power to the water electrolysis device;
a raw water supply channel that supplies raw water to the water electrolysis device;
a hydrogen gas release path that releases hydrogen gas generated in the water electrolysis device to the outside of the system;
an oxygen gas release path that releases oxygen gas generated in the water electrolysis device to the outside of the system;
A water electrolysis system comprising: A water electrolysis/fuel cell system in which multiple solid polymer water electrolysis fuel cells are stacked together, with feeders and current collectors placed on both sides of an electrolyte membrane, and separators placed outside of each feeder and current collector. A battery device,
The solid polymer type water electrolysis fuel cell integrated cell is rectangular, and the water electrolysis fuel cell integrated cell is arranged horizontally and vertically, and is stacked horizontally,
A communication port for supplying raw water during water electrolysis operation and a communication port for supplying cooling water are arranged along the lower long side of each of the rectangular water electrolysis fuel cell integrated cells,
A communication port for discharging electrolyzed water and oxygen gas during water electrolysis operation is arranged along the upper long side of each water electrolysis fuel cell integrated cell,
On the short side of each water electrolysis fuel cell integrated cell, there is a communication port for discharging hydrogen gas during water electrolysis operation, a communication port for supplying hydrogen gas during fuel cell operation, and a communication port for supplying air or oxygen gas. A water electrolysis/fuel cell device characterized in that a communication port is formed. The communication port for supplying the raw water is formed over the entire length of the electrode portion of the water electrolysis fuel cell integrated cell,
6. The water electrolysis/fuel cell device according to claim 5, wherein the communication port for discharging the electrolyzed water and oxygen gas is formed over the entire longitudinal direction of the electrode portion. A method of switching between water electrolysis operation and fuel cell operation using the water electrolysis/fuel cell device according to claim 5 or 6,
During water electrolysis operation, raw water is supplied into the water electrolysis fuel cell integrated cell from the lower long side of the rectangular water electrolysis fuel cell integrated cell toward the upper long side,
During fuel cell operation, the raw material gas is supplied into the water electrolysis fuel cell integrated cell from the short side of the rectangular water electrolysis fuel cell integrated cell toward the opposite short side. How to operate water electrolysis and fuel cells. A water electrolysis/fuel cell system using the water electrolysis/fuel cell device according to claim 5 or 6,
a power supply device that supplies DC power to the water electrolysis/fuel cell device;
a raw water supply path that supplies raw water to the water electrolysis/fuel cell device;
a hydrogen gas release path for releasing hydrogen gas generated in the water electrolysis/fuel cell device to the outside of the system;
an oxygen gas release path that releases oxygen gas generated in the water electrolysis/fuel cell device to the outside of the system;
a hydrogen gas supply path that supplies hydrogen gas to the water electrolysis/fuel cell device;
a gas supply path that supplies oxygen gas or air to the water electrolysis/fuel cell device;
A water electrolysis/fuel cell system comprising: an oxygen gas discharge path for discharging water generated in the water electrolysis/fuel cell device to the outside of the system.

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