JP3763018B2 - Hydrogen supply device using solid polymer water electrolyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water electrolyzer that electrolyzes water using a solid polymer electrolyte membrane to generate oxygen at an anode and hydrogen at a cathode, and more specifically, high-pressure hydrogen gas of 35 to 70 MPa is generated at a hydrogen station for a fuel cell. The present invention relates to a hydrogen supply device to be supplied.
[0002]
[Prior art]
Conventionally, as shown in FIG. 4, a hydrogen supply apparatus using a solid polymer type water electrolyzer electrolyzes water using a polymer electrolyte membrane and generates oxygen at the anode and hydrogen at the cathode ( 51), a hydrogen gas-liquid separator (53) for separating hydrogen and water generated at the cathode of the water electrolysis tank, and an oxygen gas-liquid separator for separating oxygen and water generated at the anode of the water electrolysis tank ( 54), a water circulation line (52) having a circulation pump (55) for circulating water so as to supply water to the water electrolyzer, and a hydrogen gas-liquid separator and a hydrogen pressure regulating valve (58) A hydrogen line (56) provided with an oxygen gas-liquid separator and an oxygen line (57) provided with an oxygen pressure regulating valve (59), and an oxygen gas-liquid separator (54) with a water supply pump (60 ) Connected through a pure water tank (61), a direct current power source (62) connected to the water electrolysis tank (51), and a pressure regulating valve (63) provided in the hydrogen line (56). .
[0003]
As shown in FIG. 5, the polymer electrolyte water electrolyzer is composed of an anode main electrode (71) and a cathode main electrode (72) arranged at both ends, and a series connection between these main electrodes (71) (72). A plurality of unit cells (86), a pair of end plates (83) sandwiching a combination of the anode main electrode (71) -the plurality of unit cells (76) -the cathode main electrode (72) from both sides, and a pair Bolts (84) and nuts (85) that pass through the four corners of the end plate (83) and tighten the anode main electrode (71), the plurality of unit cells (86), and the cathode main electrode (72) from both sides. It is mainly composed. One cell (86) includes the anode side of the bipolar plate (79), the anode feeder (77), the electrode assembly film (73), the cathode feeder (78), and the adjacent bipolar plate (79). It is mainly configured from the cathode side. At the periphery of each cell (86) is an O-ring that seals the inside and outside of the water electrolysis cell between the electrode assembly membrane (73) and the surface of the bipolar plate (79) on the cathode feeder (78) side. Is intervened.
[0004]
Oxygen generated at the anode of the water electrolysis tank (51) is sent to the oxygen gas-liquid separator (54), and hydrogen generated at the cathode is sent to the hydrogen gas-liquid separator (53). At this time, most of the water coming out of the water electrolysis tank (51) is sent to the oxygen side. The hydrogen gas-liquid separator (53) and the oxygen gas-liquid separator (54) are connected by piping, and the water level of both gas-liquid separators is always controlled to be the same. The water sent to both gas-liquid separators is adjusted in temperature by a circulating water cooler and sent again to the water electrolyzer (51) by a circulating pump (55). The supply of water to the water electrolyzer is performed by supplying pure water to the oxygen gas-liquid separator (54) by a water supply pump (60) in accordance with the preset value of the level of the oxygen gas-liquid separator (54). This is done by supplying to
[0005]
In addition, the high-pressure hydrogen having a structure in which the high-pressure hydrogen and high-pressure oxygen generated inside the water electrolysis tank are prevented from leaking out of the water electrolysis tank by disposing the water electrolysis tank having the above-described configuration in a pressure-resistant container filled with water. There is also a supply device (not shown). In this structure, since either oxygen or hydrogen is released into the pressure vessel, the inside and outside of the water electrolysis tank are at the same pressure, and there is little possibility of leakage.
[0006]
[Problems to be solved by the invention]
If high pressure hydrogen of 35 to 70 MPa is obtained in the atmosphere without using a pressure vessel, the water electrolyzer cannot withstand the internal pressure and gas may leak to the outside. Moreover, when using a pressure vessel, the attachment structure of each member in a pressure vessel becomes complicated, and operation | movement of an apparatus becomes difficult.
[0007]
An object of the present invention is to solve such a problem.
[0008]
[Means for Solving the Problems]
In a first hydrogen supply apparatus according to the present invention, a horizontal partition wall is arranged in a pressure vessel so that the inside of the vessel is divided into two upper and lower chambers, a polymer electrolyte water electrolyzer is provided in the lower chamber, and a water supply line is provided. The water supply line is pressurized and supplied from the lower chamber to the water header of the water electrolysis tank, and the upper chamber is divided into an oxygen gas-liquid separation chamber and a hydrogen gas-liquid separation chamber by a vertical partition wall. The oxygen header of the water electrolysis tank communicates with the liquid separation chamber through the oxygen side communication hole of the horizontal partition wall, and the hydrogen header of the water electrolysis tank passes through the hydrogen side communication hole of the horizontal partition wall with the hydrogen gas-liquid separation chamber. The oxygen gas / liquid separation chamber is provided with an oxygen extraction pipe and an oxygen side water discharge hole, and the hydrogen gas / liquid separation chamber is provided with a hydrogen extraction pipe and a hydrogen side water discharge line. Is.
[0009]
In the hydrogen supply apparatus, the space ratio between the oxygen gas-liquid separation chamber and the hydrogen gas-liquid separation chamber is preferably about 1: 2.
[0010]
In the second hydrogen supply device according to the present invention, the variable height partition plate is arranged horizontally in the pressure vessel so as to divide the inside of the vessel into an upper hydrogen storage chamber and a lower oxygen storage chamber. The polymer electrolyte water electrolyzer is placed in the oxygen storage chamber, the water supply line is connected to the water header of the water electrolyzer, and the hydrogen header of the water electrolyzer is connected to the oxygen reservoir. The header communicates with the oxygen storage chamber, and the oxygen storage pipe and the hydrogen discharge pipe are arranged in the hydrogen storage chamber and the oxygen storage chamber, respectively, so that airtightness between the storage chambers and between the inside and outside of the water electrolyzer is ensured. It is characterized by this.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described based on examples.
[0012]
In FIG. 1, a concave middle container (2) having a flange (2a) at the upper end is fitted into a bottomed cylindrical pressure-resistant container (1) having a flange (1a) at the upper end, and the flange (1a). (2a) The two are superimposed. A lid (3) is arranged on the middle container (2), and its peripheral edge, the flange (2a) of the middle container (2), and the flange (1a) of the pressure vessel (1) are bolts and nuts (4 ) The height of the middle container (2) is slightly shorter than half of the pressure container (1). The bottom wall (2b) of the middle container (2) serves as a horizontal partition wall that divides the inside of the pressure vessel (1) into two upper and lower chambers. A base plate (6) is horizontally arranged near the bottom of the lower chamber (28) of the pressure vessel (1) and welded to the inner surface of the lower chamber (28). In the lower chamber (28), a polymer electrolyte water electrolyzer (7) is placed between the bottom wall (2b) of the middle container (2) and the base plate (6) from above and below, and the bottom wall (2b ) And the base plate (6) with bolts and nuts (8). The tightening part of the bolt and nut (8) is coated with Teflon (registered trademark) rubber or treated with a sealant so as to prevent gas leakage of the bottom wall (2b) of the inner container (2). A DC power source (23) is connected to the polymer electrolyte water electrolyzer (7).
[0013]
The inside of the middle container (2) corresponding to the upper chamber of the pressure vessel (1) is divided into an oxygen gas-liquid separation chamber (10) and a hydrogen gas-liquid separation chamber (11) by a vertical partition wall (9). . The space of the oxygen gas / liquid separation chamber (10) and the hydrogen gas / liquid separation chamber (11) is substantially equal to the ratio of gas generation amount per unit time (1: 2).
[0014]
The lower chamber (28) is provided with a water supply line (16) having a water supply pump (20) from the water tank (19), and the water header of the polymer electrolyte water electrolyzer (7) from the lower chamber (28). In addition, a circulation line (22) having a circulation pump (21) is arranged through the side walls of the pressure vessel (1) and the middle vessel (2).
[0015]
The oxygen header of the water electrolyzer (7) communicates with the oxygen gas-liquid separation chamber (10) via the bottom wall (2b) of the middle vessel (2), that is, the oxygen side communication hole (17) opened in the horizontal partition wall. Yes. The hydrogen header communicates with the hydrogen gas-liquid separation chamber (11) through a hydrogen side communication hole (24) opened in the bottom wall (2b).
[0016]
The oxygen gas-liquid separation chamber (10) is provided with an oxygen take-out pipe (13) having a pressure regulating valve (12) on its top wall, i.e., the lid (3), and its bottom wall, i.e., the middle vessel (2). An oxygen-side water discharge hole (25) that leads to the lower chamber (28) is provided in the bottom wall of this. The hydrogen gas-liquid separation chamber (11) is provided with a hydrogen take-off pipe (15) having a pressure regulating valve (14) on its top wall, that is, a lid (3), and a hydrogen side water discharge line (18). It is arranged through the side walls of the pressure vessel (1) and the middle vessel (2) and reaches the water tank (19). The base plate (6) has a drain hole (26). An O-ring (27) is interposed between the bottom outer peripheral surface of the middle container (2) and the inner peripheral surface of the pressure vessel (1).
[0017]
In the hydrogen supply device having the above configuration, the water pressure-supplied from the water tank (19) through the water supply line (16) to the lower chamber (28) by the water supply pump (20) passes through the circulation line (22). The circulation pump (21) is pressurized and supplied to the water supply header of the polymer electrolyte water electrolyzer (7), led into each unit cell from the water supply header, electrolyzed on the surface of the catalyst electrode layer, and oxygen on the anode side. Hydrogen is generated on the cathode side. The obtained oxygen is introduced from the oxygen header through the oxygen side communication hole (17) into the oxygen gas / liquid separation chamber (10), where it is separated from entrained water and stored in a gas / liquid separation. On the other hand, the obtained hydrogen enters the hydrogen gas-liquid separation chamber (11) from the hydrogen header through the hydrogen side communication hole (24), where it is gas-liquid separated from the entrained water and stored. The volume ratio of the space portions of the hydrogen gas-liquid separation chamber (11) and the oxygen gas-liquid separation chamber (10) is substantially equal to the gas generation ratio (= 2: 1) per unit time. From the oxygen gas-liquid separation chamber (10), the high-pressure oxygen gas adjusted to a pressure of 35 to 70 MPa by adjusting the pressure regulating valve (12) through the oxygen take-out pipe (13), on the other hand, the hydrogen gas-liquid separation chamber (11) The high-pressure hydrogen gas adjusted to a pressure of 35 to 70 MPa by adjusting the pressure adjusting valve (14) through the hydrogen extraction pipe (15) is balanced and obtained at the same pressure. Under such conditions, the gas pressure is made the same inside and outside the water electrolysis tank (7) in the pressure vessel (1), so there is a possibility that gas leaks from the inside of the water electrolysis tank to the outside even at a high pressure of 35 to 70 MPa. Absent. The water in the oxygen gas / liquid separation chamber (10) is returned to the lower chamber (28) through the oxygen side water discharge hole (25), and the water in the hydrogen gas / liquid separation chamber (11) passes through the hydrogen side water discharge line (18). After that, it is returned to the water tank (19).
[0018]
Example 2
In FIG. 2, the height variable partition plate (32) is divided into an upper hydrogen storage chamber (48) and a lower oxygen storage chamber (34) in a vertically long cylindrical pressure vessel (31). Are arranged horizontally. The variable height partition plate (32) is suspended in the pressure vessel (31) via a spring (35) by a suspension member (33) provided in an inward projecting manner on the pressure vessel (31). The suspension member (33) also serves as an upper stopper. A slidable O-ring (36) is interposed between the outer peripheral surface and the inner peripheral surface of the pressure vessel (31). Below the variable height partition plate (32), a pressure-resistant container (31) is provided with a lower stopper (37) projecting inwardly, and the variable height partition plate (32) is suspended as an upper stopper. Between the member (33) and the lower stopper (37), it can move up and down slidably with respect to the pressure vessel (31) while ensuring airtightness between the chambers (48) and (34). A solid polymer type water electrolyzer (38) is disposed in the oxygen storage chamber (34), and a water supply line (39) is connected to a feed header of the water electrolyzer (38). A water pressure pump (40) and a flow rate control valve (41) are provided, and a water circulation line (42) from the oxygen storage chamber (34) is connected. The hydrogen header of the water electrolyzer (38) communicates with the hydrogen storage chamber (48) by a vertical vent pipe (43) that penetrates the variable height partition plate (32) in an airtight manner, and the oxygen header is the oxygen storage chamber (34). Communicating with Each of the hydrogen storage chamber (48) and the oxygen storage chamber (34) is provided with an oxygen extraction pipe (45) having a pressure adjustment valve (44) and a hydrogen extraction pipe (47) having a pressure adjustment valve (46). Yes.
[0019]
In the hydrogen supply apparatus configured as described above, the water pressure-supplied to the water supply header of the water electrolysis tank (38) by the water supply line (39) is guided from the water supply header into each unit cell, and on the surface of the catalyst electrode layer. Electrolysis is performed to generate oxygen on the anode side and hydrogen on the cathode side. The obtained oxygen exits from the water electrolyzer (38) through the oxygen header and is then stored in the oxygen storage chamber (34) .Hydrogen passes from the water electrolyzer (38) through the hydrogen header and then passes vertically. It is guided into the hydrogen storage chamber (48) through the trachea (43) and stored therein. The variable height partition plate (32) is slidably moved up and down relative to the pressure vessel (31), and is balanced so that no differential pressure is generated between the oxygen storage chamber (34) and the hydrogen storage chamber (48). This prevents the electrode assembly membrane of the water electrolysis tank (38) from being damaged. The high pressure oxygen gas adjusted to a pressure of 35 to 70 MPa by adjusting the pressure regulating valve (44) from the oxygen storage chamber (34) through the oxygen extraction pipe (45), on the other hand, the hydrogen extraction pipe from the hydrogen storage chamber (48). Through (47), the high-pressure hydrogen gas adjusted to a pressure of 35 to 70 MPa by adjusting the pressure adjusting valve (46) is balanced and obtained at the same pressure. The water at the bottom of the oxygen storage chamber (28) is returned to the water supply line (39) through the water circulation line (42).
[0020]
【The invention's effect】
According to the first invention, it is possible to provide a safe hydrogen supply device that does not cause a gas leak due to a difference in pressure (35 to 70 MPa) between the atmosphere and the water electrolyzer. Moreover, since the gas-liquid separator provided separately outside can also be omitted normally, the apparatus can be simplified.
[0021]
According to the second invention, since the variable height partition plate (32) can be slidably moved up and down with respect to the pressure vessel (31), the differential pressure between the oxygen storage chamber (34) and the hydrogen storage chamber (48). Does not occur. This effectively prevents the electrode assembly membrane of the water electrolysis tank from being damaged.
[Brief description of the drawings]
FIG. 1 is a vertical longitudinal sectional view showing a hydrogen supply device according to Embodiment 1. FIG.
FIG. 2 is a vertical longitudinal sectional view showing a solid polymer type water electrolysis tank.
3 is a vertical longitudinal sectional view showing a hydrogen supply device according to Embodiment 2. FIG.
FIG. 4 is a schematic view showing a hydrogen supply apparatus using a conventional solid polymer type water electrolyzer.
FIG. 5 is a vertical longitudinal sectional view showing a conventional solid polymer type water electrolyzer.
[Explanation of symbols]
(1) (31): Pressure vessel
(15) (47): Hydrogen extraction pipe
(13) (45): Oxygen extraction pipe
(34): Oxygen storage chamber
(7) (38): Solid polymer water electrolyzer
(2): Middle container
(3): Lid
(28): Lower room
(6): Base plate
(9): Vertical partition wall
(10): Oxygen gas-liquid separation chamber
(11): Hydrogen gas-liquid separation chamber
(18): Hydrogen side water discharge line
(25): Oxygen side water discharge hole
(32): Height variable partition plate
(35): Spring
(36): O-ring
(16) (39): Water supply line
(43): Vertical ventilation pipe
(48): Hydrogen storage chamber

Claims (3)

A horizontal partition wall is arranged in the pressure vessel so as to divide the inside of the vessel into two upper and lower chambers, a solid polymer type water electrolyzer is provided in the lower chamber and a water supply line is arranged so that the water in the water supply line is in the lower chamber Is pressurized and supplied to the water header of the same water electrolyzer, and the upper chamber is divided into an oxygen gas-liquid separation chamber and a hydrogen gas-liquid separation chamber by a vertical partition wall. Communicates through the oxygen side communication hole of the horizontal partition wall, the hydrogen header of the water electrolysis tank communicates with the hydrogen gas-liquid separation chamber through the hydrogen side communication hole of the horizontal partition wall, and oxygen gas in the oxygen gas-liquid separation chamber. A solid polymer water electrolyzer was used, characterized in that an extraction pipe and an oxygen-side water discharge hole were provided in the hydrogen gas-liquid separation chamber, respectively, and a hydrogen extraction pipe and a hydrogen-side water discharge line were provided. Hydrogen supply device. The hydrogen supply apparatus according to claim 1, wherein a space ratio between the oxygen gas-liquid separation chamber and the hydrogen gas-liquid separation chamber is 1 : 2. A variable height partition plate is horizontally arranged in the pressure vessel so as to divide the inside of the vessel into an upper hydrogen storage chamber and a lower oxygen storage chamber, and is suspended in the pressure vessel via an elastic member to store oxygen. The polymer electrolyte water electrolyzer is placed in the chamber, the water supply line is connected to the water header of the water electrolyzer, the hydrogen header of the water electrolyzer is connected to the hydrogen reservoir, and the oxygen header is connected to the oxygen reservoir, respectively. Solid polymer type water characterized in that an oxygen take-out pipe and a hydrogen take-out pipe are arranged in the storage chamber and the oxygen storage chamber, respectively, so that airtightness between the two storage chambers and airtightness between the inside and outside of the water electrolyzer are secured. A hydrogen supply device using an electrolytic cell.

Images