JP4206500B2 - Hydrogen supply device using solid polymer water electrolyzer - Google Patents

Description

This invention uses the solid polymer electrolyte membrane electrolyze water, oxygen on the anode relates to a solid-state polymer type water electrolysis cell for generating hydrogen on the cathode, and more particularly, in the hydrogen station for example, a fuel cell 35~70MPa The present invention relates to a hydrogen supply apparatus using a polymer electrolyte water electrolyzer capable of supplying a high-pressure hydrogen gas.

A hydrogen supply device using a solid polymer type water electrolyzer is conventionally known as disclosed in, for example, Patent Document 1, and the solid polymer type water electrolyzer (51) As shown in FIGS. 6 and 7, an anode main electrode (1) and a cathode main electrode (2) arranged at both ends, and a plurality of these arranged in series between these main electrodes (1) and (2). A unit cell (16) and a pair of end plates (13) sandwiching a combination of an anode main electrode (1) -a plurality of unit cells (16) -cathode main electrode (2) from both sides are mainly constituted. One cell (16) consists of the anode side of the bipolar plate (90), the anode feeder (7), the electrode assembly film (3), the cathode feeder (8), and the adjacent bipolar plate (90). The electrode assembly membrane (3) is mainly configured from the cathode side, and includes an ion exchange membrane (4) and catalyst electrode layers (5) and (6) provided on both sides thereof. On the periphery of each cell (16), the inside and outside of the polymer electrolyte water electrolyzer are connected between the electrode assembly membrane (3) and the surface of the bipolar plate (90) on the cathode feeder (8) side. An O-ring (17) for sealing is interposed. The solid polymer water electrolyzer (51) has a water supply header (10) formed at the center of the lower end and a hydrogen header (11) and an oxygen header (12) formed in parallel with the upper end. Has been.

In this hydrogen supply device, heat is generated by the electrolytic reaction of the polymer electrolyte water electrolyzer (51), and the exhaust heat is generated by the movement of the circulating water on the oxygen side and the latent heat of vaporization of the water vapor on the hydrogen side. Further, in this apparatus, the internal pressure is maintained by an O-ring (17) provided on the outer periphery of the solid polymer water electrolyzer (51), and the pressure of the generated gas is 1.1 MPa (10 kg / cm ² G).

Patent Document 2 discloses that a polymer electrolyte water electrolyzer is installed in a pressure vessel.
JP-A-11-256380 JP-A-6-33283

  By the way, the use of hydrogen in fuel cells is advancing, and for that purpose, supplying high-pressure hydrogen gas of 35 to 70 MPa at a hydrogen station for fuel cells has become a problem.

However, when water electrolysis is performed at a high pressure of about several tens of MPa using the above-described conventional hydrogen supply apparatus, there is a problem that the seal by the O-ring is broken. Therefore, as disclosed in Patent Document 2, it is conceivable to install a solid polymer type water electrolyzer in the pressure vessel. However, the point that can cope with a high pressure of about several tens of MPa and the structure of the pressure vessel are possible as much as possible. Satisfactory products have not been obtained in terms of simple and small capacity.

  In the present invention, even when water electrolysis is performed at a high pressure of about several tens of MPa, the electrolyte membrane is prevented from being damaged, and has sufficient pressure resistance, and the pressure vessel structure is as simple and small in capacity as possible. It is an object of the present invention to provide a hydrogen supply device using a solid polymer type water electrolyzer that can be used.

A hydrogen supply apparatus using a solid polymer type water electrolyzer according to the present invention comprises a polymer electrolyte membrane for electrolyzing water to generate oxygen at the anode and hydrogen at the cathode, A hydrogen supply device consisting of a pressure vessel with a lid that contains a polymer electrolyte water electrolyzer, and is fixed to the bottom surface of the pressure vessel lid by pressing the polymer electrolyte water electrolyzer against the bottom wall of the pressure vessel body the downward projecting shape of the electrolytic cell presser set vignetting Rukoto you, between the solid polymer water electrolyzer and the lid, the clearance corresponding to the length of the electrolytic cell retainer is formed, a solid polymer type water By adjusting the pressure of pure water supplied to the electrolyzer, an electrolyzed water layer is secured in the gap, and a layer of generated hydrogen gas is formed above the electrolyzed water layer, thereby also characterized in that the hydrogen gas-liquid separator at the top is formed It is.

A pressure vessel is formed by covering a cylindrical vessel body whose upper end is open, and a solid polymer type water electrolysis tank is, for example, a bipolar plate, an anode feeder, and an electrode assembly film constituting the same. And the cathode feeders are all arranged horizontally, and either one of the front and back sides of each bipolar plate is provided with a horizontal parallel passage serving as a passage for the electrolyzed water and oxygen of each cell. A horizontal parallel passage is formed, and a hydrogen gas passage of each cell is joined to a hydrogen header extending vertically through each bipolar plate. The electrolytic water passage in the solid polymer type water electrolysis bath is electrolyzed water is forced through a pump or the like, thereby, oxygen, hydrogen on the cathode to generate an anode. Since the generated hydrogen moves upward in the polymer electrolyte water electrolyzer and is stored at the top of the pressure vessel, hydrogen can be obtained by providing a hydrogen gas-liquid separator at the top of the pressure vessel. it can.

In the case where the electrolyzed water passages in the polymer electrolyte water electrolyzer are formed in parallel in the horizontal direction, the electrolyzed water is used in comparison with the case where the electrolyzed water is supplied by a single feed header. Since the entire polymer electrolyte water electrolyzer can be cooled almost uniformly and the flow rate of the electrolyzed water can be increased, the polymer electrolyte water electrolyzer is efficiently cooled. The temperature is suppressed from locally exceeding the heat-resistant temperature, and even when water electrolysis is performed at a high pressure of about several tens of MPa, the electrolyte membrane is prevented from being damaged.

It is preferable that a solid polymer type water electrolyzer is formed by densely laminating a bipolar plate having an O-ring fitted on the outer periphery in the container body. In this way, the radial extension of the O-ring is regulated by the inner peripheral surface of the pressure vessel, and the O-ring is not damaged even if the internal pressure of the solid polymer type water electrolysis tank becomes high. Even when gas is required, the pressure vessel can be made small and simple.

Moreover, the pressure vessel is formed by covering a cylindrical vessel body whose upper end is open with an insulating layer interposed therebetween, and the vessel body and the lid are preferably electrodes. Since the electrode of the pressure vessel and the solid polymer water electrolyzer direct contact, usually to form a pressure vessel is made of metal with an insulating material, an electrode of a solid polymer type water electrolysis cell in the pressure vessel exterior Although it is possible to take out, the structure for taking out the electrode of the solid polymer type water electrolyzer to the outside of the pressure vessel by using the vessel main body and the lid as an electrode utilizing the fact that the pressure vessel is made of metal Can be omitted.

According to the hydrogen supply apparatus using the polymer electrolyte water electrolyzer of the present invention, a configuration in which the polymer electrolyte water electrolyzer is accommodated in the pressure vessel is adopted, and the polymer electrolyte water electrolyzer is attached to the bottom of the pressure vessel body. By making the electrolytic cell holder pressed against the wall between the polymer electrolyte water electrolytic cell and the lid, the structure of the pressure vessel can be made as simple and as small as possible. Even when water electrolysis is performed at a high pressure of about MPa, it is possible to prevent damage to the electrolyte membrane and ensure sufficient pressure resistance. In addition, since a gap serving as a hydrogen gas / liquid separator is formed between the solid polymer water electrolyzer and the lid, the hydrogen gas / liquid separator can be omitted from the hydrogen supply device.

  Hereinafter, the present invention will be specifically described with reference to the drawings. In the following description, left and right and top and bottom refer to the left and right and top and bottom of FIG.

In FIG. 1, a hydrogen supply apparatus using a solid polymer type water electrolyzer uses a polymer electrolyte membrane to electrolyze water, and generates oxygen at the anode and hydrogen at the cathode, respectively. (40), a pressure vessel (41) with a lid (42) for accommodating the solid polymer water electrolyzer (40), and a hydrogen gas-liquid separation unit (43) provided on the top of the pressure vessel (41) A hydrogen line (44) provided in the hydrogen gas-liquid separator (43), an oxygen line (45) connected to the water / oxygen discharge port on the peripheral wall of the pressure vessel (41), and an oxygen line (45). An oxygen gas-liquid separator (46) provided with an oxygen gas-liquid separator (46) for separating oxygen and water generated at the anode of the polymer electrolyte water electrolyzer (40) and a circulation pump (48) ( 46) and a water circulation line (47) connecting the water inlet of the pressure vessel (41), and a DC power source (not shown) connected to the solid polymer type water electrolyzer (40).

As shown in FIG. 3, each cell (16) of the polymer electrolyte water electrolyzer (40) has an anode side of a bipolar plate (19), an anode feeder (7), an electrode assembly film (3), It is mainly configured from the cathode side of the cathode feeder (8) and the adjacent bipolar plate (19). The electrode assembly membrane (3) includes an ion exchange membrane (4) and catalyst electrode layers (5) and (6) provided on both sides thereof.

  The bipolar plate (19) is obtained by grinding a thick plate. As shown in FIG. 2 (a) and FIG. 4, the bipolar plate (19) has a disk shape, and parallel passages (19a, 19b) are formed on both sides thereof. In addition, an O-ring (50) is fitted in an annular groove provided on the outer periphery. In FIG. 4, the passage provided on the upper surface of the bipolar plate is the passage (19a) on the oxygen generation side, and the passage provided on the lower surface is the passage (19b) on the hydrogen generation side. The hydrogen generation side passage (19b) does not open to the outer periphery of the bipolar plate (19) as shown in FIG. 5C, whereas the oxygen generation side passage (19a) As shown in FIGS. 5A and 5B, an open communication passage (19c) that opens to the outer periphery of the bipolar plate (19) and that serves as an inlet for water and an outlet for water and oxygen is communicated. . The open communication path (19c) does not open on the upper and lower surfaces of the bipolar plate (19), but opens only on the outer periphery.

The bipolar plate (19) with the O-ring (50) is horizontally layered so that the passages (19a) and (19b) are oriented horizontally and the O-ring (50) is in contact with the inner periphery of the pressure vessel (41). Are stacked. In the polymer electrolyte water electrolyzer (40) formed by laminating the bipolar plate (19), the anode feeder (7), the electrode assembly film (3) and the cathode feeder (8), A hydrogen header (49) is formed in a direction penetrating vertically.

  As shown in FIG. 5, the hydrogen header (49) has a vertical through-hole (49a) that penetrates the bipolar plate (19), the anode feeder (7), the electrode assembly film (3), and the cathode feeder (8). ) And a pair of passage forming rings (55) (55) (55) (58) fitted into stepped holes (57) (58) provided in each bipolar plate (19) via O-rings (53) (54). 56). Each of the passage forming rings (55) and (56) is made of ceramic or heat-resistant resin (for example, engineering plastic), and has a small diameter portion having the same inner diameter and a smaller outer diameter at one end. One O-ring (53) is fitted into the outer periphery of the small-diameter portion, and the other O-ring (54) is fitted into the annular groove on the end surface without the small-diameter portion so as not to be exposed to the passage. The end surfaces of the large-diameter portions of the forming rings (55) and (56) are abutted against each other, and the end surfaces of the small-diameter portions are brought into contact with the portion having the smallest inner diameter of the bipolar plate. The hydrogen side passage forming ring (56) is provided with a plurality of small holes (56a) of about 1 to 2 mm on the side surface.

Thus, in the polymer electrolyte water electrolyzer (40), horizontal parallel passages (19a) (19c) that serve as passages for electrolytic water and oxygen in each cell and horizontal parallel passages that serve as hydrogen gas passages in each cell. A passage (19b) and a vertical hydrogen header (49) in which these hydrogen gas passages are joined are formed. The O-ring (50) fitted to the outer periphery of the bipolar plate (19) is suppressed from increasing in diameter by the inner periphery of the pressure vessel (41).

The pressure vessel (41) is formed by covering a cylindrical vessel body whose upper end is open with a lid (42) through an insulating layer.In this embodiment, the vessel body is a cathode and a lid (42 ) Is the anode. A downwardly projecting electrolytic cell holder (42a) is provided on the lower surface of the lid (42) of the pressure vessel (41). The electrolytic cell holder (42a) presses the entire polymer electrolyte water electrolyzer (40) against the bottom wall of the container body, and the lid (42) of the pressure vessel (41) and the polymer electrolyte water electrolyzer (40 A gap corresponding to the length of the electrolytic cell holder (42a) is formed between the upper surface and the upper surface. By adjusting the pressure of pure water supplied to the polymer electrolyte water electrolyzer (40), an electrolyzed water layer is secured in the gap, and the generated hydrogen gas layer is located above the electrolyzed water layer. Thus, a hydrogen gas-liquid separator (43) is formed at the top of the pressure vessel (41).

According to the hydrogen supply apparatus using the polymer electrolyte water electrolyzer of this embodiment, the electrolyzed water forcedly fed into the polymer electrolyte water electrolyzer (40) by the circulation pump (48) is a bipolar plate. Flowing from left to right through the horizontal parallel passages (19a) and (19c) of (19), being decomposed into hydrogen and oxygen, and serving as cooling water for the polymer electrolyte water electrolyzer (40), the pressure vessel Discharged from (41). Oxygen generated at the anode flows through the parallel parallel passages (19a) and (19c) of the bipolar plate (19) together with the electrolyzed water, and hydrogen generated at the cathode is horizontal parallel of the bipolar plates (19) of each cell. It flows through the passage (19b), joins the hydrogen header (49), and is stored at the top of the pressure vessel (41). The purity of the hydrogen gas is increased in the hydrogen gas-liquid separator (43) at the top of the pressure vessel (41), and is adjusted to a predetermined pressure by a check valve pressure valve (44a) provided in the hydrogen line (44). Supplied to the outside. A conventional bipolar plate is formed by corrugating thin plates into a corrugated shape, resulting in variations in contact between the ion exchange membrane (4) and the catalyst electrode layers (5) and (6) due to pressure deflection. However, by using the bipolar plate (19) obtained by grinding a thick plate, variation can be suppressed and hydrogen can be stably obtained.

The exhaust heat from the polymer electrolyte water electrolyzer (40) is such that the circulating water cooled in the pressure vessel (41) is introduced to fill the gap with the polymer electrolyte water electrolyzer (40). Has been done by. When water electrolysis is performed at high pressure, the amount of water vapor generated on the hydrogen side is drastically reduced. Compensated by heat. Thus, even when high-pressure hydrogen gas is generated, the electrode assembly membrane (electrolyte membrane) (3) is prevented from being damaged.

  In addition, since the conventional rubber bush is not used to form the hydrogen header (49), the problem of poor processing accuracy and large thermal deformation due to the rubber bush is eliminated. .

  In the above description, the bipolar plate (19) has a disc shape. However, as shown in FIG. 2 (b), the bipolar plate (19) is a square plate shape with corners chamfered and rounded. It can also be used. The bipolar plate (19) is formed by grinding a thick aluminum plate to form passages (19a) and (19b), and the surface is coated with titanium / platinum. The passages (19a) and (19b) may be curved or bent.

By manufacturing the bipolar plate (19) with a manufacturing method that performs groove grinding on a thick plate, the peripheral edge of the bipolar plate (19) can be made thicker, the strength of the bipolar plate (19) is increased, and the high pressure Even when the gas is generated, the cell is not distorted and the pressure resistance is improved. Furthermore, the rigidity of the entire cell is increased by tightening, and a high-strength polymer electrolyte water electrolyzer is obtained.

It is the schematic which shows the hydrogen supply apparatus using the solid polymer type water electrolyzer by this invention. It is a perspective view which shows an example of a bipolar plate, and its modification. It is a vertical longitudinal cross-sectional view which shows the principal part of a solid polymer type water electrolyzer. It is a figure which shows the detail of the channel | path shape of a bipolar plate, (a) is the front view seen from the advancing direction of water, (b) is a top view, (c) is a bottom view. It is sectional drawing which shows the detail of a hydrogen header. It is a disassembled perspective view which shows the conventional polymer-type water electrolyzer. It is a vertical sectional view showing a conventional polymer type water electrolyzer.

Explanation of symbols

(40): Solid polymer water electrolyzer
(41): Pressure vessel
(42): Lid
(42a): Electrolyzer holder
(43): Hydrogen gas-liquid separator
(49): Hydrogen header
(50): O-ring

Claims (4)

Hydrogen comprising a polymer electrolyte water electrolyzer that electrolyzes water using a polymer electrolyte membrane to generate oxygen at the anode and hydrogen at the cathode, and a pressure vessel with a lid for housing the polymer electrolyte water electrolyzer A feeding device,
The lower surface of the lid of the pressure vessel, by Rukoto downward projecting shape of the electrolytic cell holding you fixed against a solid polymer water electrolyzer in the bottom wall of the pressure vessel body is set vignetting, solid polymer water electrolyzer A gap corresponding to the length of the electrolytic cell holder is formed between the lid and the lid, and an electrolytic water layer is secured in this gap by adjusting the pressure of pure water supplied to the solid polymer type water electrolytic cell A solid polymer water electrolyzer characterized in that a hydrogen gas-liquid separation part is formed at the top of the pressure vessel by forming a layer of the generated hydrogen gas above the electrolyzed water layer. Hydrogen supply device using The increase in the diameter of the O-ring is suppressed by the inner periphery of the pressure vessel body by densely laminating a bipolar plate having an O-ring fitted on the outer periphery thereof. A hydrogen supply apparatus using the solid polymer water electrolyzer described in 1.   The solid container according to claim 1 or 2, wherein the pressure vessel is formed by covering a cylindrical vessel body having an open upper end with an insulating layer interposed between the lid and the vessel body and the lid as electrodes. A hydrogen supply device using a polymer water electrolyzer. In the solid polymer type water electrolyzer, the bipolar plate, the anode feeder, the electrode assembly film and the cathode feeder constituting the same are all arranged in a horizontal shape, A horizontal parallel passage serving as a passage for electrolytic water and oxygen of the cell is formed on the other side, and a horizontal parallel passage serving as a hydrogen gas passage for each cell is formed on the other side. The hydrogen gas passage of each cell is connected to each bipolar plate. It is joined to a hydrogen header that penetrates and extends vertically, a hydrogen gas-liquid separation unit provided at the top of the pressure vessel, a hydrogen line provided in the hydrogen gas-liquid separation unit, and a pressure vessel An oxygen line connected to the water / oxygen discharge port on the peripheral wall, and an oxygen gas-liquid separator provided in the oxygen line and separating oxygen and water generated at the anode of the solid polymer water electrolyzer Hydrogen supply using the polymer electrolyte water electrolyzer according to claim 1, 2 or 3 Apparatus.

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