JP2006131935A - Water electrolysis cell enclosed in container in water-electrolysis hydrogen-generating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water electrolysis cell enclosed in a container in a water-electrolysis hydrogen-generating apparatus, which has a simple structure, is easily assembled and can generate a large amount of hydrogen. <P>SOLUTION: The water electrolysis cell enclosed in the container in the water-electrolysis hydrogen-generating apparatus comprises: the water electrolysis cells (24) and (24') respectively fixed on facing surfaces of a bilateral pair of end plates (21) and (21'); a trunk-shaped body (22) having the end plates arranged on both ends so as to store the water electrolysis cells in the body; and a pressure vessel (25) formed by fixing the end plates to the body, wherein the water electrolysis cells are electrically serially connected with each other. Thus configured water electrolysis cell enclosed in a container in a water-electrolysis hydrogen-generating apparatus has a simple structure, is easily assembled and can generate a large amount of hydrogen. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water electrolysis hydrogen generator that generates high-pressure hydrogen gas by electrolysis of water using a solid polymer electrolyte membrane. More specifically, the present invention relates to low-pressure hydrogen gas and several tens of MPa, such as a fuel cell vehicle. The present invention relates to a water electrolysis hydrogen generator capable of generating high-pressure hydrogen gas of at least 40 MPa, preferably 80 MPa, which is required in a hydrogen station for traveling the same distance as a gasoline vehicle, and particularly to a container-containing water electrolysis tank.

  A polymer electrolyte membrane that electrolyzes water, generates oxygen at the anode and hydrogen at the cathode, and a hydrogen gas / liquid that separates water and hydrogen generated at the cathode of the water electrolysis tank Water having a separator, an oxygen gas-liquid separator that separates oxygen and water generated at the anode of the water electrolysis tank, and a water supply line having a water supply pump that supplies water from the pure water tank to the water electrolysis tank An electrolytic hydrogen generator is already known. The container-accommodating water electrolysis hydrogen generator is a container in which the solid polymer water electrolysis tank as described above is stored in a container capable of maintaining a predetermined high pressure.

  Conventionally, as shown in FIG. 4, a container-containing water electrolysis hydrogen generator is a solid polymer water electrolyzer that electrolyzes water using a polymer electrolyte membrane and generates oxygen at the anode and hydrogen at the cathode, respectively. (120), a pressure vessel (121) having a water inlet on the left side wall, a water / oxygen outlet on the right side wall, and containing the water electrolyzer (120), and hydrogen gas provided on the top wall of the pressure vessel Extraction device (122), hydrogen line (123) provided in hydrogen gas extraction device, oxygen line (124) connected to water / oxygen discharge port of pressure vessel, water electrolysis tank provided in oxygen line An oxygen gas-liquid separator (125) for separating oxygen and water generated at the anode of (120), a water circulation line (126) connecting the oxygen gas-liquid separator and the water inlet of the pressure vessel, and a water electrolyzer And a DC power source (not shown) connected to (120). The pressure vessel (121) is composed of a cylindrical member and cone-shaped end wall members provided at both ends thereof (see Patent Document 1).

  However, in the container-accommodating water electrolysis hydrogen generator having such a configuration, a large ingot is required to produce a large-capacity pressure vessel from a metal ingot, but it is extremely difficult to obtain such an ingot. .

  Moreover, in the conventional container-accommodated water electrolysis hydrogen generator, the water electrolyzer is prevented from being damaged by preventing a differential pressure from being generated between the inside and outside of the water electrolyzer and between the anode and the cathode.

In this method, since only one water electrolysis tank can be installed in the pressure vessel, it is necessary to increase the number of unit cells stacked in one water electrolysis tank in order to generate a large amount of hydrogen. However, when the number of unit cells is increased, it becomes difficult to manufacture the water electrolyzer, and it is difficult to ensure the sealing performance on the anode side and the cathode side.
Japanese Patent Laid-Open No. 204-2914, in particular, Example 1 and FIG.

  SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a container-encased water electrolyzer in a water electrolysis hydrogen generator that is simple in construction and easy to assemble and that can generate a large amount of hydrogen. And

  The present invention has been devised to solve the above problems.

  In the invention according to claim 1, the water electrolyzer is fixed to the opposing surfaces of the pair of left and right end plates, and the end plates are arranged at both ends of the cylindrical body so that the water electrolyzer is accommodated in the body. Is a container-accommodating water electrolyzer in a water electrolysis hydrogen generator, in which a pressure vessel is formed by fixing to a body and water electrolyzers are electrically connected in series.

  According to a second aspect of the present invention, the pair of left and right end plates and the body are electrically insulated, the anode of the power source is connected to the anode of the water electrolysis tank fixed thereto via the left end plate, and the cathode of the power source is connected It is a container storage type water electrolyzer in the water electrolysis hydrogen generator according to claim 1, which is connected to the cathode of the water electrolyzer fixed to it through the right end plate.

  The invention according to claim 3 is the water electrolysis hydrogen according to claim 1, wherein the pressure vessel is provided with an oxygen outlet through which the anode side outlet of each water electrolysis tank communicates with the inside of the pressure vessel and oxygen generated at each anode is extracted. It is a container accommodation type water electrolyzer in a generating device.

  The invention according to claim 4 is the water electrolysis hydrogen according to claim 1, wherein a hydrogen outlet through which the cathode side outlet of each water electrolysis tank and the inside of the pressure vessel are communicated and hydrogen generated at each cathode is extracted is provided in the pressure vessel. It is a container accommodation type water electrolyzer in a generating device.

  The invention which concerns on Claim 5 produces two end plates which fixed the water electrolyzer on one side, and connects the non-end plate side electrodes of these water electrolyzers with the connection member which passes through the inside of a cylindrical body, Next, the container-accommodating water electrolyzer is assembled in the water electrolysis hydrogen generator, in which end plates are fixed to the openings at both ends of the body so that each water electrolyzer is accommodated in the body.

For example, the following methods are used to connect the electrodes of the water electrolyzer:
When the connection is made of a stretchable cable, one end of the cable connection is attached to the power supply terminal of one water electrolysis tank, and then one end plate is fixed to the one end opening of the body with the connection directed to the body. Next, after the other end of the connection is attached to the other power supply terminal through the body, the other end plate is fixed to the other end opening of the body.

  When the connection is made of a conductive rod, attach one end of the rod connection to the feed terminal (the terminal that does not flex the shape) of one of the water electrolyzers, and then connect the end plate to the fuselage with the connection facing the fuselage. It fixes to the opening part of one end. Next, the other end of the rod connection is attached to the power supply terminal (elastically deformed terminal) of the other water electrolysis tank, both the power supply terminals are in contact with each other, the other is bent, and the other end plate is attached to the other body. Secure to the end opening.

  According to the present invention, the total number of unit cells can be doubled without increasing the number of unit cells stacked in one water electrolyzer. In addition, in order to generate the same amount of hydrogen as in the conventional apparatus, the number of unit cells stacked in one water electrolyzer can be halved. Therefore, the apparatus can be made compact and the apparatus can be easily assembled and maintained.

  By connecting the anode and cathode of the power supply to the anode and cathode of the water electrolysis tank via the left and right end plates constituting the pressure vessel, no current introduction terminal is required inside the pressure vessel, and the configuration of the device is simplified. To improve its reliability.

  By connecting the anode side outlet or the cathode side outlet of each water electrolyzer with the inside of the pressure vessel, the pressure vessel can have a function as a gas-liquid separator. This gas-liquid separation can be easily achieved by placing a pressure vessel with a water electrolyzer inside.

  Moreover, the pressure difference between the anode and the cathode in the stacked unit cell constituting the water electrolysis tank was reduced by communicating the anode side outlet or cathode side outlet of each water electrolysis tank and the inside of the pressure vessel in this way. High pressure hydrogen and oxygen can be generated in the state.

  High-pressure hydrogen and oxygen can be generated with a small pressure difference between the anode and cathode by filling the pressure vessel with water at the same pressure as the supply water to the unit cell and the generated gas. .

  Thus, according to the present invention, the structure is simple, the assembly is easy, and a large amount of hydrogen can be produced.

  Hereinafter, the present invention will be specifically described based on examples. In the following description, the left and right refer to the left and right with reference to FIG.

Example 1
In FIG. 1, two stainless steel discs are prepared for use as the left and right end plates (21) (21 ') of the pressure vessel. The disc may be made of steel or titanium. The water electrolyzers (24) and (24 ') are respectively fixed to one side of these discs using the electrolyzer support bolts (14) and (14'). The water electrolysis tanks (24) and (24 ′) are for electrolyzing water using a polymer electrolyte membrane to generate oxygen at the anode and hydrogen at the cathode. The left water electrolyzer (24) includes a cathode main electrode (2), a plurality of unit cells (16) arranged in series between the end plate (21) and the cathode main electrode (2), and a plurality of units. The end plate (21) and presser plate (13) sandwiching the cell (16) -cathode main electrode (2) combination from both sides, and through the four corners of the end plate (21) and presser plate (13) It mainly comprises a plate (21), a plurality of unit cells (16), and a bolt (14) and a nut (15) for fastening the cathode main electrode (2) from both sides. The base end portion of each bolt (14) is screwed into the screw hole of the end plate (21). One cell (16) consists of the anode side of the bipolar plate (9), the anode feeder (7), the electrode assembly film (3), the cathode feeder (8), and the adjacent bipolar plate (9). It is mainly configured from the cathode side. An insulating layer (17) is interposed between the cathode main electrode (2) and the presser plate (13). The right side water electrolyzer (24 ') is opposite in direction to the left side water electrolyzer (24), but has the same configuration.

  On the other hand, a cylindrical body (22) having flange portions (23) (23 ') at both ends is prepared. The body (22) is integrally made from a stainless steel ingot, but may be made from a steel or titanium ingot. In addition, depending on the working pressure, standard piping can be used as the material of the body (22). A pair of left and right end plates (21) (21 ') with water electrolyzers fixed on one side are placed on the left and right sides of the body (22), and water electrolyzers (24) (24') are placed in the body (22). To arrange. The outer edge of the end plate (21) (21 ') and the flange (23) (23') of the fuselage (22) are joined together with an insulating layer (30) (30 ') interposed between them, and the bolt (27 ). Thus, the pressure vessel (25) is formed from the body (22) and the pair of left and right end plates (21) (21 ') fixed to both ends thereof. A pressure vessel (25) having water electrolyzers (24) and (24 ') is placed on a pair of left and right bases (29) and (29'). The pair (21 ′) and the body (22) are electrically insulated by the insulating layers (30) and (30 ′).

  A pair of left and right water electrolyzers (24) and (24 ') are electrically connected in series by a connecting member (37). The connecting member (37) includes a pair of left and right power supply terminals (28) and (28 ') arranged in an opposing manner and a connection (38) for connecting these horizontal portions. The lower end of the vertical portion of the left feeding terminal (28) is fixed to the upper surface of the cathode main electrode (2) of the left water electrolysis tank (24). The vertical portion is made of a thin strip, and can absorb displacement due to thermal expansion of the left water electrolyzer (24). The right feeding terminal (28 ') has the same configuration as that on the left.

  The anode-side inlet / outlet of the water electrolyzer (24) (24 ′) is communicated with the inside of the pressure vessel (25).

  One power supply (26) is provided, and its anode is connected to the anode of the water electrolysis tank (24) fixed to it via the left end plate (21), and the cathode of the power source (26) is connected to the right end plate ( It is connected via 21 ') to the cathode of the water electrolyzer (24') fixed to it.

  In the container-accommodating water electrolysis hydrogen generator configured as described above, pure water is supplied into the pressure vessel (25) from the water supply port (31) provided at the upper portion of the left end plate (21) constituting the pressure vessel (25). And the water electrolyzer (24) (24 ') is stored in the container so as to be submerged. As a result, water is supplied to each anode of the water electrolysis tanks (24) and (24 '), and the generated oxygen is discharged from the water electrolysis tanks (24) and (24') to the inside of the pressure vessel (25). The gas is separated from the gas and taken out from an upper gas outlet (32) provided at the upper part of the pressure vessel (25). Hydrogen and entrained water generated at each cathode of the water electrolyzer (24) (24 ') are taken out from the end central gas outlet (33) (33') provided at the center of both end walls of the pressure vessel (25). Then, it is sent to a gas-liquid separation tank outside the pressure vessel (25), and gas-liquid separation is performed in the tank. When the water in the pressure vessel (25) decreases, water is replenished from the water supply port (31). During maintenance, water is extracted from the water outlet provided at the lower part of the pressure vessel (25). Further, when using the apparatus, the pressure on the anode side and the cathode side is adjusted by peripheral devices so that the seals provided on the electrode assembly membrane and the electrolytic cell are not broken.

Example 2
In FIG. 2, in the container-accommodating water electrolysis hydrogen generator of this configuration, pure water is supplied from the water supply port (31) provided on the upper side of the left end plate (21) constituting the pressure vessel (25). Supply to the anode side of the water electrolyzer (24) of the pressure vessel (25). Hydrogen and entrained water are discharged from the cathode side into the pressure vessel (25). Hydrogen is gas-liquid separated in the container and taken out from the upper gas outlet (32) provided in the upper part of the pressure container (25). Oxygen generated at the anode of the water electrolysis tank (24) and the remaining water are taken out from the gas outlet (35) located below the end wall of the pressure vessel (25), and then outside the pressure vessel (25). It is sent to the gas-liquid separation tank and gas-liquid separation is performed in this tank. During maintenance or to prevent entrained water from losing the hydrogen gas storage space in the container, the accompanying water is withdrawn from the water outlet provided at the bottom of the pressure vessel (25) as necessary. .

  Since this apparatus has a symmetrical configuration, the right half is omitted in FIG. Other configurations are the same as those of the first embodiment.

Example 3
In FIG. 3, in the container-accommodating water electrolysis hydrogen generator of this configuration, pure water is supplied at two locations near the center and the upper end of the left end plate (21) constituting the pressure vessel (25). The water is supplied from the water supply ports (31) and (34) into the pressure vessel (25). Oxygen generated in each anode of the water electrolysis tank (24) is taken out together with water from the side lower gas outlet (35) provided below the end plate (21) of the pressure vessel (25), and the water electrolysis tank (24 The hydrogen generated at each cathode of the pressure vessel (25) is taken out from the side central gas outlet (33) provided at the center of the end plate (21) of the pressure vessel (25). Water in the pressure vessel (25) is discharged from a water discharge port (36) provided near the lower end of the end plate (21). Since this apparatus also has a symmetrical configuration, the right half of FIG. 3 is omitted. Other configurations are the same as those of the second embodiment.

1 is a vertical longitudinal sectional view schematically showing a container-accommodating water electrolysis hydrogen generator of Example 1. FIG. It is a vertical longitudinal cross-sectional view which shows roughly the container accommodation type | formula water electrolysis hydrogen generator of Example 2. FIG. It is a vertical longitudinal cross-sectional view which shows the container accommodation type | formula water electrolysis hydrogen generator of Example 3 roughly. It is a vertical longitudinal cross-sectional view which shows schematically the conventional container accommodation type water electrolysis hydrogen generator.

Explanation of symbols

(13): Presser plate
(14) (14 '): Bolt
(16): Cell
(17) (30) (30 '): Insulating layer
(21) (21 '): End plate
(22): Torso
(23) (23 '): Flange
(24) (24 '): Water electrolyzer
(25): Pressure vessel
(26): Power supply
(27): Bolt
(28) (28 '): Feeding terminal
(29) (29 '): Base
(31) (34): Water supply port
(32): Upper gas outlet
(33) (33 '): End central gas outlet
(35): Gas outlet at the lower end
(36): Water outlet
(37): Connection member
(38): Connection

Claims (5)

The water electrolyzer is fixed to the opposing surfaces of the pair of left and right end plates, these end plates are arranged at both ends of the cylindrical body so that the water electrolyzer is accommodated in the body, and the end plate is fixed to the body and the pressure vessel A container-encased water electrolyzer in a water electrolysis hydrogen generator, wherein the water electrolyzers are electrically connected in series. A pair of left and right end plates and the fuselage are electrically insulated, and the anode of the power source is connected to the anode of the water electrolyzer fixed to it via the left end plate, and the cathode of the power source is connected to it via the right end plate. The container-accommodating water electrolyzer in the water electrolysis hydrogen generator according to claim 1, wherein the container is housed in a water electrolyzer. The container-encased water electrolysis in the water electrolysis hydrogen generator according to claim 1, wherein the pressure vessel is provided with an oxygen outlet through which the anode outlet of each water electrolysis tank communicates with the inside of the pressure vessel, and oxygen generated at each anode is extracted. Tank. The container-encased water electrolysis in the water electrolysis hydrogen generator according to claim 1, wherein the pressure vessel is provided with a hydrogen outlet through which the cathode side outlet of each water electrolysis tank communicates with the inside of the pressure vessel to extract hydrogen generated at each cathode. Tank. Two end plates each having a water electrolysis tank fixed on one side are prepared, and the non-end plate side electrodes of these water electrolysis tanks are connected to each other by a connecting member passing through the inside of the cylindrical body, and then each water electrolysis tank is connected to the body. An assembly method for a container-accommodating water electrolysis tank in a water electrolysis hydrogen generator, wherein end plates are fixed to the opening portions at both ends of the body so as to be housed in the water electrolysis hydrogen generator.

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