JP2002038287A - Hydrogen/oxygen supplying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen/oxygen supplying system which can control flowing pure water and produced gas or the like adequately and can maintain the quality of the produced gas (supplying gas) effectively. SOLUTION: The hydrogen/oxygen supplying system which is composed to have an electrolytic cell (1) in which an anode side is isolated from a cathode side by a solid electrolytic film, to generate hydrogen in the above cathode side by supplying pure water to the anode side of the above electrolytic cell (1), to generate oxygen at the above anode side, and to be able to supply the above hydrogen and oxygen to a utilization point, comprises that a pressure of the above cathode side is set to be higher than that of the above anode side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water electrolysis apparatus for generating hydrogen gas and oxygen gas by electrolyzing pure water, and more particularly to a hydrogen / oxygen supply system using the water electrolysis apparatus. It is.

[0002]

2. Description of the Related Art Conventionally, as a water electrolysis apparatus constituting a hydrogen / oxygen supply system, an apparatus using an electrolytic cell having a solid electrolyte membrane as a member serving as an electrolyte is known.

[0003] An electrolysis cell according to the prior art is a solid polymer electrolyte membrane / electrode assembly membrane (hereinafter, referred to as a solid polymer electrolyte membrane) in which electrode catalyst layers (anode side and cathode side catalyst layers) are provided on both sides of a solid polymer electrolyte membrane. Electrolyte membrane "), an electrode plate (anode and cathode side electrode plates) provided to sandwich the solid electrolyte membrane, and a power supply (anode side) provided between the solid electrolyte membrane and the electrode plate. And a cathode side power supply).

[0004] In the above-mentioned electrolytic cell according to the prior art,
By supplying pure water to the anode side and supplying electricity to the electrode plate, pure water is decomposed mainly in the anode side catalyst layer, and oxygen gas is generated. The H ⁺ ions generated simultaneously with the oxygen gas move in the solid electrolyte membrane by the action of an electric field, so that electrons are obtained in the cathode-side catalyst layer and hydrogen gas is generated.

That is, in the prior art, the above-described electrolytic cell, a control means for energizing the electrolytic cell, a pure water tank provided for supplying pure water to (the anode side of) the electrolytic cell, and an electrolytic cell are used. A hydrogen / oxygen supply system is configured using a hydrogen separation tank that stores the generated hydrogen gas, and a piping section that connects these components.

[0006]

However, in the hydrogen / oxygen supply system according to the prior art described above, the solid electrolyte membrane constituting the electrolytic cell is extremely thin (50 to 20).
0 μm) Since the member is a soft member, stress is generated in the solid electrolyte membrane due to the operating state of the system or a change in the gas supply amount (that is, a change in the generated gas amount based on the change in the gas supply amount). However, there has been a problem that it is not possible to exhibit predetermined performance, and it is difficult to appropriately maintain the quality of generated hydrogen and oxygen. In addition, when the system is continuously operated, if the supply amount of pure water or the demand amount and supply amount of gas fluctuates greatly, it is difficult to generate hydrogen and oxygen having predetermined quality. there were.

Therefore, the present invention has been made to solve the above-described problems of the prior art, and does not apply any extra stress to the solid electrolyte membrane (that is, the solid electrolyte membrane can be properly applied). It is an object of the present invention to provide a hydrogen / oxygen supply system configured so as to be able to effectively maintain the quality of product gas. It is another object of the present invention to provide a hydrogen / oxygen supply system configured to appropriately control flowing pure water, generated gas, and the like to effectively maintain the quality of generated gas (supply gas). And

[0008]

That is, the present invention for solving the above-mentioned problems has an electrolytic cell separated on the anode side and the cathode side by a solid electrolyte membrane, and supplies pure water to the electrolytic cell. In the hydrogen / oxygen supply system wherein hydrogen is generated on the cathode side and oxygen is generated on the anode side, and at least one of the hydrogen and oxygen can be supplied to a use point. The side is set to a pressure higher than the anode side, or the anode side is set to a pressure higher than the cathode side.

According to the hydrogen / oxygen supply system of the present invention, since the pressure on the cathode side (or the anode side) in the electrolytic cell is set high, the pressure from the anode side to the cathode side is high. (Or from the cathode side to the anode side) it is possible to prevent the generated gas and the like from permeating. That is, according to the present invention, by setting the pressure on the cathode side (or the anode side) high, the hydrogen generated on the cathode side (or the hydrogen generated on the anode side) For oxygen),
Mixing of the oxygen generated on the anode side (or the oxygen generated on the cathode side) can be effectively prevented. Therefore, according to the present invention, a high-quality product gas (high-purity hydrogen gas or high-purity oxygen gas) can be obtained.

Further, in the hydrogen / oxygen supply system according to the present invention, a first pressure detecting means capable of detecting a pressure of the hydrogen supplied through the cathode side of the electrolytic cell; A second pressure detecting means capable of detecting the pressure of the oxygen supplied via the anode side, a pressure detection signal obtained by the first pressure detecting means and a pressure detection signal obtained by the second pressure detecting means. Differential pressure detecting means that can generate a predetermined differential pressure signal by comparing the pressure differential signal with the detected pressure detection signal, a first relief mechanism that can adjust the pressure of the hydrogen based on the differential pressure signal, And a second relief mechanism capable of adjusting the pressure of the oxygen based on the anode side pressure and the cathode side pressure in the electrolytic cell are adjusted using the first and second relief mechanisms. Is preferred.

According to this preferred configuration, the pressures of the oxygen and the hydrogen supplied through the anode side and the cathode side are constantly monitored using the first and second pressure detecting means. And the differential pressure signal obtained by the differential pressure detecting means can control the first and second relief mechanisms capable of adjusting each pressure.
Therefore, according to this preferred configuration, the pressure on the cathode side of the solid electrolyte membrane can be set high easily and without particularly applying stress, so that the solid electrolyte membrane is effectively protected. Thus, a high-quality product gas (high-purity hydrogen gas or high-purity oxygen gas) can be obtained.

Further, in the hydrogen / oxygen supply system according to the present invention, the first relief mechanism includes a first relief pipe provided in a hydrogen separation tank storing the hydrogen, And a first relief valve that can be controlled based on the differential pressure signal provided in the relief pipe section, and the second relief mechanism stores the oxygen generated in the electrolytic cell. A second relief pipe provided in the oxygen separation tank, and a second relief valve that can be controlled based on the differential pressure signal provided in the second relief pipe. Is preferred.

In this preferred configuration, each of the relief mechanisms is formed by using the relief pipe portion and the relief valve, and each of the relief valves can be opened and closed based on the differential pressure signal. The flow path diameter of the relief pipe portion can be adjusted). Therefore, according to this preferred configuration, without having a particularly complicated configuration, by adjusting the pressure around the solid electrolyte membrane,
A hydrogen / oxygen supply system capable of protecting the solid electrolyte membrane and obtaining a high-quality product gas can be obtained.

In the hydrogen / oxygen supply system according to the present invention, an electrolytic cell is accommodated in the oxygen separation tank, and pure water in the oxygen separation tank can be circulated without contacting outside air. It is preferable that a circulation pipe section is provided in the oxygen separation tank, and the pure water is supplied to the anode side of the electrolytic cell via the pure water circulation pipe section.

According to this preferred configuration, since the pure water is constantly supplied to the electrolytic cell via the pure water circulation pipe section, a stable quality product gas is obtained. It becomes possible. According to this configuration, even when the system is continuously operated, the solid water is supplied stably without applying extra stress to the solid electrolyte membrane. It is possible to effectively protect the electrolyte membrane and obtain a stable quality product gas.

Further, the hydrogen / oxygen supply system according to the present invention has a hydrogen gas supply pipe section for supplying the hydrogen, and a hydrogen gas flow control means provided in the hydrogen gas supply pipe section. The hydrogen gas flow rate control means is configured using a flow rate detection means and a rated flow rate control valve, and detects the supply flow rate of the hydrogen by the flow rate detection means, based on a detection signal from the flow rate detection means. By adjusting the rated flow control valve, it is preferable that the hydrogen flowing through the hydrogen gas supply pipe is controlled to have a rated flow.

According to this preferred configuration, a demand exceeding the permissible amount of the hydrogen that can be generated by the hydrogen / oxygen supply system is made on the downstream side of the hydrogen gas supply pipe section,
In order to meet the demand, even if any signal is sent to the electrolytic cell, since the supply amount of the hydrogen is limited to the rated flow rate in the hydrogen gas supply pipe section, Hydrogen (exceeding an appropriate amount generated in the electrolytic cell) does not flow through the hydrogen gas supply pipe. Therefore, according to this preferred configuration, no matter how the amount of use of the hydrogen on the downstream side of the hydrogen gas supply pipe changes, the hydrogen flows at a rated flow rate or more in the hydrogen gas supply pipe. Therefore, it is possible to effectively prevent excessive operation of the electrolytic cell and maintain the quality of the hydrogen at a constant level. In addition,
Here, a system for obtaining high-purity hydrogen as a generated gas is shown; however, the present invention is not limited to this configuration, and may be a system for obtaining high-purity oxygen gas. Such a system has an oxygen gas supply pipe unit for supplying the oxygen, and an oxygen gas flow control unit provided in the oxygen gas supply pipe unit, wherein the oxygen gas flow control unit includes a flow detection unit. A rated flow control valve, and the supply flow rate of the oxygen is detected by the flow rate detection means, and the rated flow control valve is adjusted based on a detection signal from the flow rate detection means, whereby the What is necessary is just to be comprised so that the said oxygen which circulates in an oxygen gas supply piping part may be controlled so that it may become a rated flow.

Further, in the hydrogen / oxygen supply system according to the present invention, a pure water tank for supplying the pure water to the electrolytic cell is provided, and the pure water in the pure water tank is provided with the pure water. Preferably, bubbling is performed using the oxygen generated in the electrolytic cell.

According to this preferred configuration, by bubbling the pure water with the oxygen, it is possible to effectively remove air (particularly nitrogen) as impurities in the pure water. High-purity hydrogen or oxygen can be obtained.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic system diagram of a hydrogen / oxygen supply system according to an embodiment of the present invention.
The hydrogen / oxygen supply system according to the present embodiment mainly includes a water electrolysis device 1 configured using an electrolysis cell, a pure water tank 3 for supplying pure water to the water electrolysis device 1, and a water electrolysis device. It is configured using a hydrogen separation tank 4 and the like for storing and supplying the hydrogen generated in 1. The details will be described below.

In the hydrogen / oxygen supply system according to this embodiment, pure water is supplied to an oxygen separation tank (electrolysis tank) 2 provided with a water electrolysis apparatus 1 through a pure water supply pipe section 5. The pure water tank 3 is connected. Also,
The pure water supply pipe section 5 has a make-up water pump 6 for supplying (supplying) the pure water stored in the pure water tank 3 to the electrolytic tank 2.
Is provided. The pure water tank 3 is provided with a pure water tank water level meter 3L for detecting the amount of pure water stored in the pure water tank 3, and a detection signal obtained by the pure water tank water level meter 3L is a pure water tank. 3 is supplied to a pure water supply valve 3A of a pure water supply unit provided to supply pure water to the pure water supply valve 3A. The amount of pure water stored in the pure water tank 3 is appropriately controlled by adjusting the pure water supply valve 3A based on the detection signal of the pure water tank water level gauge 3L. The electrolytic tank 2 has an electrolytic tank water level meter 2L for detecting the amount of pure water stored in the electrolytic tank 2.
The detection signal obtained by the electrolytic tank water level meter 2L is sent to a makeup water pump. The amount of pure water stored in the electrolytic tank 2 is controlled by appropriately adjusting the driving state of the makeup water pump 6 based on the detection signal of the electrolytic tank water level meter 2L.

The electrolytic tank 2 is provided with a pure water circulating pipe section 7 for circulating and reusing the pure water in the electrolytic tank 2. 2
After taking out the pure water from inside the electrolysis tank 2, the piping is configured so that it can be supplied again to a pure water supply hole (described later) of the water electrolysis device 1 (the electrolysis cell constituting the water electrolysis device 1).
A circulating water pump 8 for circulating pure water, a heat exchanger 9 for performing heat exchange of pure water (to lower the temperature of pure water), a pure water A polisher 10 for increasing the purity of the filter, a filter 11 for filtering pure water, and the like are provided. As the polisher 10, for example, a non-regenerative polisher made of an ion exchange resin or the like is used. Further, the pure water circulation pipe section 7 monitors the quality (electric conductivity) of the pure water in the pure water circulation pipe section 7 and, when necessary, a predetermined electric conductivity (for example, 0.2 μS / cm), the temperature of pure water in the pure water circulation pipe section 7 and the temperature of the pure water in the pure water circulation pipe section 7 are monitored, and if necessary (for example, a predetermined temperature range (for example, 40 to 45)). If the temperature exceeds (° C.), a water temperature warning means 13 for issuing a warning is provided. The pure water circulated through the pure water circulation pipe section 7 is:
Since it is pure water in which oxygen gas is dissolved, dissolved oxygen may be discharged from the pure water into the pure water circulation pipe section 7. As described above, when the oxygen gas is discharged, the oxygen gas accumulates in the circulating water pump 8, the polisher 10, the filter 11, or the like provided in the pure water circulation pipe section 7, and the oxygen gas is used for the circulation of the pure water. There is a risk of causing a malfunction. Therefore, in the present embodiment, a gas vent is provided in at least one of the circulating water pump 8, the polisher 10, and the filter 11.

The hydrogen gas generated in the water electrolysis device 1 in the electrolysis tank 2 is sent to the hydrogen separation tank 4 via the hydrogen gas transfer pipe section 14 together with a small amount of pure water. The hydrogen gas transfer pipe section 14 is provided with a hydrogen gas transfer valve 18 and a bypass pipe section 19 so as to bypass the hydrogen gas transfer valve 18 on the hydrogen gas transfer pipe section 14. The bypass pipe 19 is provided with a check valve 20.

The hydrogen separation tank 4 includes a hydrogen separation tank 4
A hydrogen separation tank water level meter 4L for detecting the amount of pure water stored in the tank is provided, and a detection signal obtained by the hydrogen separation tank water level meter 4L is supplied from the hydrogen separation tank 4 to the pure water tank 3 with respect to pure water. (To discharge and reuse pure water)
It is sent to the pure water discharge valve 4A of the provided pure water return piping section 15. If it is determined by the hydrogen separation tank water level meter 4L that a predetermined amount or more of pure water is stored in the hydrogen separation tank 4, pure water discharge is performed based on the detection signal of the hydrogen separation tank water level meter 4L. By adjusting the valve 4A, the amount of pure water stored in the hydrogen separation tank 4 is appropriately controlled. Further, the pure water flowing in the pure water return pipe section 15 has hydrogen dissolved, albeit slightly. Therefore, in the present embodiment, a gas scrubber 16 is provided in the pure water return pipe section 15, and a hydrogen release pipe section 17 is connected to the gas scrubber 16. Therefore, in the present embodiment, the hydrogen dissolved in the pure water discharged from the hydrogen separation tank 4 is appropriately removed.

The hydrogen gas stored in the hydrogen separation tank 4 is transported and supplied to a location (not shown) where the hydrogen gas is used through a hydrogen gas supply pipe 21. And
The hydrogen gas supply pipe section 21 has a hydrogen gas supply valve 22 for adjusting the supply amount of hydrogen gas, a hydrogen gas dehumidifier 23 for dehumidifying the hydrogen gas, and a hydrogen gas dehumidifier 23 for maintaining the flow rate of the hydrogen gas at the rated flow rate. Hydrogen gas flow rate control means 24 is provided. The hydrogen gas flow control means 24 is connected to the hydrogen gas supply pipe 21 through the hydrogen gas supply valve 22.
And a rated flow control valve 24B which can be controlled based on a detection signal obtained by the flow detection means 24A. Here, the hydrogen gas dehumidifying means 23
Is configured using, for example, a hollow fiber membrane. In the hydrogen gas dehumidifying means 23, the hydrogen gas is dehumidified by flowing hydrogen gas inside the hollow fiber membrane and flowing dry air outside the hollow fiber membrane. Although not particularly shown in FIG. 1, in order to obtain hydrogen gas of higher purity (for example, 7N (99.99999) or more), the downstream side of the hydrogen gas dehumidifier 23 or the hydrogen gas Instead of dehumidifying means, zeolite,
It is preferable to provide a purifier using a molecular sieve such as activated alumina. In this embodiment, the hydrogen gas dehumidifying means 23 (or a purifier) using a hollow fiber membrane or the like is used.
Therefore, there is no need to use a palladium purifier or the like, which is required in the prior art. Further, the hydrogen gas supply valve 22 is controlled based on the pressure of the hydrogen separation tank 4 as described later. For this purpose, the hydrogen separation tank 4 is provided with a first pressure detecting means 25.

Further, the hydrogen separation tank 4 is provided with a first relief pipe section 27 having a first relief valve 26. The first relief valve 26 is configured to be controlled based on the pressure of the electrolytic tank 2 and the pressure of the hydrogen separation tank 4 as described later.

Oxygen gas generated in the water electrolysis apparatus 1 in the electrolysis tank 2 is stored in the upper part of the electrolysis tank 2, and is supplied to an oxygen gas supply piping section (not shown) with respect to the use location (not shown) of the oxygen gas. It is conveyed and supplied through 31. The oxygen gas supply pipe section 31 includes an oxygen gas supply valve 32 for adjusting the supply amount of oxygen gas, an oxygen gas dehumidifying means 33 for dehumidifying oxygen gas, and an oxygen gas supply pipe section 3.
And a hydrogen gas detecting means 34 for detecting the concentration of hydrogen in the oxygen gas flowing through the fuel cell 1. here,
The oxygen gas supply valve 32 is connected to the electrolytic tank 2 as described later.
And the pressure of the hydrogen separation tank 4 is controlled. For this purpose, the electrolytic tank 2 is provided with a second pressure detecting means 35. Also, the oxygen gas dehumidifying means 3
3 is formed using, for example, a hollow fiber membrane or the like. In the oxygen gas dehumidifying means 33, the oxygen gas is dehumidified by flowing oxygen gas inside the hollow fiber membrane and flowing dry air outside the hollow fiber membrane.

Further, the electrolytic tank 2 is provided with a second relief pipe section 37 having a second relief valve 36. The second relief valve 36 is configured to be controlled based on the pressure of the electrolytic tank 2 and the pressure of the hydrogen separation tank 4 as described later.

Further, in the present embodiment, the detected value of the first pressure detecting means 25 and the detected value of the second pressure detecting means 35 are compared, and a predetermined signal is transmitted to various valves 22 and 2.
6, 32 and 36 are provided with a differential pressure detecting means 45 which can be sent. Further, in the present embodiment, the water electrolysis device 1 receives the pressure detection signal from the first pressure detection means 25 and receives the pressure detection signal.
Is provided with a current value control means 28 for supplying an appropriate current to the current.

As described above, the hydrogen / oxygen supply system according to the present embodiment is configured by using the water electrolysis apparatus 1, which supplies pure water and a predetermined current. By using an electrolytic cell capable of producing hydrogen and oxygen. Next, the structure of the electrolytic cell will be described with reference to the drawings.

FIG. 2 is a schematic view showing an example of an electrolysis cell constituting a water electrolysis apparatus constituting the hydrogen / oxygen supply system according to FIG. 1, and FIG. 2 (a) is a plan view of the electrolysis cell. FIG. 2B is a cross-sectional view of a part of FIG.
FIG. 2 shows a side view taken along the arrow I. FIG. 3 is similar to FIG.
FIG. 2A is a cross-sectional view illustrating a main part of a cross section taken along line II-II of FIG. FIG. 4 is a cross-sectional view showing a main part of a cross section taken along the line III-III in FIG. FIG. 5 is an exploded perspective view of an electrode plate unit constituting the electrolytic cell according to the present embodiment. In the present embodiment, FIG.
The electrolytic cell is configured using the electrode plate unit and the solid electrolyte membrane shown in FIG.

The electrolytic cell 1 shown in FIGS. 2 to 4 comprises a solid electrolyte membrane 102 in which electrode catalyst layers (anode side and cathode side catalyst layers) are provided on both surfaces of a solid polymer electrolyte membrane and an electrode plate unit 103. It is configured by laminating a plurality. That is,
The solid electrolyte membrane 102 and the electrode plate unit 103 are sandwiched by the electrode plate unit 103.
Are laminated in a predetermined number. Then, the solid electrolyte membrane 102 and the electrode plate unit 103 are sandwiched between end plates 122 provided on both ends, and are tightened by tightening bolts 123, so that the electrolytic cell 1
Is configured.

Further, in the electrolytic cell 1 according to this embodiment, a nut 124 is attached to the tightening bolt 123 via a plurality of disc springs 125. When assembling the electrolytic cell, the solid electrolyte membrane 102, the electrode plate unit 103, and the like are stacked and then tightened by a tightening bolt 123 or the like while being tightened by a press.

The electrode plate unit 103 has a structure in which a porous power supply 105, a spacer 106, a sealing member 107 and the like are disposed on both sides of an electrode plate 104 made of a titanium plate. As will be described later, the oxygen holes 11 used to take out the generated oxygen gas are formed in the spacer 106 and the like.
3. A hole 114 for hydrogen used to take out the generated hydrogen gas and holes 115 and 116 for pure water used to supply pure water to be used for electrolysis are formed.

Next, the structure of the electrode plate 104 and its surroundings will be described in detail with reference to FIG.

The electrode plate 104 includes a plate portion 104a serving as an inner portion thereof, and a peripheral portion 104b provided on an outer peripheral portion of the plate portion 104a. Also, between the plate portion 104a and the peripheral edge portion 104b, an outer side ridge 1 is provided.
12a and the inner side protrusion 112b are formed.
That is, the groove 111 for the sealing member 107 is formed by bending along the inner edge of the peripheral portion 104b.
The outer side and the inner side of the groove 111 are bent so as to form protrusions 112 a and 112 b along the groove 111.
The electrode plate 104 can be obtained by molding a titanium plate by a mold press. Further, a predetermined portion of the electrode plate 104 that comes into contact with (and may come into contact with) when the electrode plate units 103 are stacked is provided with a coating for electrical insulation. For example, Teflon (registered trademark) is provided at the bottom of the seal member groove 111.
(Polytetrafluoroethylene) coating.

On both sides of the electrode plate 104, porous power supply members 105 (A) and 105 (C) are disposed at the center thereof, and spacers 106 are disposed on both sides of the porous power supply member 105, respectively. . Also, this spacer 106
The spacers 106c and 106d on the lower surface are changed to the spacers 106 on the upper surface due to the presence of the inward protrusions 112b.
a, 106b.

An annular spacer 106e is fitted in the dead space on the back side (lower side) of the inner side ridge 112b. Fluid passage holes (holes for oxygen 113, holes for hydrogen 114, holes for pure water 115 and 116) are formed at corresponding positions in the electrode plate 104 and the spacer. Specifically, as shown in FIGS. 3, 4, and 5,
Oxygen holes 113 and hydrogen holes 114 formed at predetermined positions of the left spacers 106a and 106c of the electrode plate 104 and the corresponding electrode plate 104, and the right spacers 106b and 106d and the corresponding electrodes are formed. Board 104
The holes 115 and 11 for pure water are drilled at predetermined positions.
6.

In FIGS. 3, 4 and 5, the space on the upper surface side of the electrode plate 104 is the hydrogen generation chamber C, and the space on the lower surface side is the oxygen generation chamber A. A seal member 107 for sealing the hydrogen generation chamber C and the oxygen generation chamber A from the outside is fitted into the groove 111 formed by bending the electrode plate 104.

As shown in FIGS. 3, 4, and 5, an O-ring groove 117 is formed around the oxygen hole 113 on the lower surface of the spacer 106a on the upper left side of the electrode plate 104. A hydrogen groove 118 is formed from the hydrogen hole 114 to the edge facing the porous power supply. An O-ring groove 117 is also formed around the oxygen hole 13 on the upper surface of the spacer 106a.

Further, an O-ring groove 117 is formed around the hydrogen hole 114 on the upper surface of the spacer 106 c on the lower left side of the electrode plate 104, and the edge facing the porous power supply 105 from the oxygen hole 113. An oxygen groove 119 is formed up to this point. An O-ring groove 117 is also formed around the hydrogen hole 114 on the lower surface of the spacer 106c.

Further, both the upper surface and the lower surface of the spacer 106b on the right side of the upper surface of the electrode plate 104
An O-ring groove 117 is formed around 116. The spacer 106d on the lower right side of the electrode plate 104
A groove 120 for pure water is formed from the holes 115 and 116 for pure water on the upper surface to the edge facing the porous feeder 105. Each O-ring groove 117 has an O-ring 121
Is fitted.

The groove 120 for pure water formed in the spacer 106d on the lower right side is formed in a different shape from the groove 118 for hydrogen and the groove 119 for oxygen formed in the other spacers 106a and 106c. That is, the hydrogen groove 118 and the oxygen groove 119 are formed as one independent groove.
14 and holes 113 for oxygen. However, the pure water groove 120 is formed in the wide recess 12 communicating with the two pure water holes 115 and 116.
0a and a plurality of small grooves 120b formed from the recess 120a to the edge facing the porous power supply body 105. The recess 120a of the groove 120 for pure water, the small groove 12
0b is formed in a substantially fan shape. This is devised so that pure water, which is the water to be decomposed, reaches the porous power supply 105 as uniformly as possible.

In this embodiment, since the spacers 106 are formed by using a metal such as titanium for the purpose of improving the strength, etc., there is no space between each spacer 106 and the electrode plate 104. , Each spacer 106a, 106
b, 106c, insulating sheet 1 according to the size of 106d
09a, 109b, 109c, and 109d are provided. Fluid passage holes (oxygen holes 113, hydrogen holes 114, and pure water holes 115, 116) are formed at predetermined positions (at corresponding positions) in the insulating sheet 109, respectively. Further, the hydrogen gas transfer piping section 14 shown in FIG. 1 is connected to the hydrogen hole 114.

Further, in the electrolytic cell 1 according to the present embodiment, a shim is provided on the outer peripheral portion 104b (the outer peripheral portion of the plate portion 104a and the outer peripheral portion of the outer protrusion 112a) which is a part of the electrode plate 104. 110 are provided.

In the present embodiment, as described above,
A hydrogen / oxygen supply system is formed using a water electrolysis apparatus (electrolysis cell) 1 configured by the electrolysis cells shown in FIGS. Therefore, as shown in FIG. 1, in the water electrolysis apparatus 1 provided in the electrolysis tank 2, the pure water in the electrolysis tank 2 flows from the two pure water holes 115 and 116 through the pure water groove 120. , Electrode plate 104 serving as oxygen generation chamber A
Pure water is supplied to the porous power supply body 105 on the lower surface side of. Pure water is prevented from flowing into the hydrogen generation chamber C by the O-ring 121.

The oxygen gas generated in the oxygen generation chamber A is released from the oxygen groove 119 through the oxygen hole 113 into the electrolytic tank 2, and is discharged from the electrolytic tank 2 to the oxygen gas supply pipe section 3.
The oxygen gas is supplied to a place where oxygen gas is used through 1 or the like. In the water electrolysis device 1, the oxygen gas is prevented from flowing into the hydrogen generation chamber C by the O-ring 121. Further, the hydrogen gas generated in the hydrogen generation chamber C is transported to the hydrogen separation tank 4 via the hydrogen groove 118, the hydrogen hole 114, and the hydrogen gas transport pipe section 14. Hydrogen gas is O-ring 1
By 21, the flow into the oxygen generation chamber A is prevented. Furthermore, naturally, in the water electrolysis device according to the present embodiment, the generated hydrogen gas and oxygen gas are prevented from leaking from between the electrode plate units 103 to the outside by the seal member 107. .

The hydrogen / oxygen supply system according to the present embodiment is configured as shown in FIGS. 1 to 5 described above. In such a system, pure water supply control, current value control, and the like are appropriately performed. ing.

FIG. 6 shows a flowchart when the hydrogen / oxygen supply system according to this embodiment is operated. Hereinafter, the control method will be specifically described using necessary drawings such as FIG.

As shown in FIG. 6, in the hydrogen / oxygen supply system according to the present embodiment, first, in step 601, pure water is supplied to the electrolytic tank 2. Specifically, the makeup water pump 6 is driven to supply pure water from the pure water tank 3 to the electrolytic tank 2.

Next, in step 602, the storage amount (water level) of pure water in the electrolytic tank 2 is detected using the electrolytic tank water level meter 2L.

Next, in step 603, it is determined whether or not the water level in the electrolytic tank 2 is a predetermined amount based on the water level detection signal in step 602. When the water level has reached the predetermined amount (when it is determined “Yes” in step 603),
Next, the process of step 604 is performed. If the water level has not reached the predetermined amount (if determined to be “No” in step 603), the processes after step 602 are performed again with the makeup water pump 6 driven. .

Next, in step 604, water supply from the pure water tank 3 to the electrolytic tank 2 is stopped based on the determination in step 603. That is, the makeup water pump 6 is stopped. Next, in step 605,
The amount of circulating water supplied to the electrolytic cell 1 is detected. That is, in step 605, the circulating water pump 8 is driven before supplying electricity to the electrolytic cell 1 to supply pure water to the electrolytic cell 1, so that the amount of circulating water is detected.

Next, in step 606, it is determined whether a predetermined amount of water is supplied to the electrolytic cell 1 based on the circulating water amount detection signal in step 605. Then, if the circulating water amount has reached the predetermined amount (if “Yes” is determined in step 606), then the process of step 607 is performed. If the amount of circulating water has not reached the predetermined amount (if “No” is determined in step 606), the process does not proceed to step 607 but proceeds to step 6 again.
05 is performed (that is, the circulating water pump 8
And the detection of the amount of circulating water is continuously performed.)

Next, in step 607, energization of the water electrolysis apparatus 1 is started. That is, in the hydrogen / oxygen supply system according to the present embodiment, after a predetermined amount of pure water is circulated in the water electrolysis device (electrolysis cell) 1, the supply of current to the water electrolysis device 1 is performed for the first time. Is started. The reason why the energization is started after confirming the circulating water flow rate is that if the energization is performed in a state where the pure water is not sufficiently supplied to the water electrolysis apparatus 1, the solid electrolyte constituting the water electrolysis apparatus 1 This is because the film 102 may be damaged. That is, in the present embodiment, in order to protect the solid electrolyte membrane 102, the current is supplied to the water electrolysis apparatus 1 after confirming the circulation amount of pure water. Here, the supply of current to the water electrolysis device 1 is 0%
A predetermined time (for example, about 30 seconds) is required to increase the current value from (0 A) to 100% (for example, 600 A). By supplying the current in this manner, the current is gradually applied to the solid electrolyte membrane 102, so that the solid electrolyte membrane 102 can be protected. That is, the supply current to the water electrolysis apparatus 1 fluctuates rapidly (in an extreme case, the ON / OF
F) Then, an overshoot occurs and an excessive current is applied to the electrolytic cell, which may damage the solid electrolyte membrane.
According to the above-described current supply means (stepwise current supply means) according to the present embodiment, such a problem can be effectively solved.

Next, in step 608, continuous hydrogen / hydrogen supply by the hydrogen / oxygen supply system shown in FIG.
An oxygen supply step is performed. Specifically, appropriate pure water supply control, current value control, and the like are performed. These controls will be specifically described later.

Next, in step 609, hydrogen
A determination is made as to whether to terminate the oxygen supply step. If it is determined that the hydrogen / oxygen supply process is to be terminated (if “Yes” is determined in step 609), the process of step 610 is performed. If it is determined that the hydrogen / oxygen supply process is not to be ended (if “No” is determined in step 609), the processes in and after step 608 are performed again.

Next, in step 610, energization of the water electrolysis apparatus 1 is terminated based on the determination of the termination of the hydrogen / oxygen supply step in step 609. Although not particularly shown in the flowchart of FIG. 6, in step 610, the energization is terminated in a state where the water electrolysis apparatus 1 is sufficiently filled with pure water. Specifically, the circulating water pump 8 is stopped several seconds (about 3 seconds) after the power supply to the water electrolysis device 1 is stopped. This is also because no extra load is applied to the solid electrolyte membrane 102.

As described above, the operation of the hydrogen / oxygen supply system according to the present embodiment is controlled based on the steps 601 to 610 in FIG. However, the description of the hydrogen / oxygen supply step in the above-described flowchart of FIG. 6 is insufficient, so that the hydrogen / oxygen supply step performed in step 608 will be specifically described.

In the hydrogen / oxygen supply step performed in step 608, the supply of pure water to the electrolytic tank 2 is controlled.
And current value control for the water electrolysis device 1. The details will be described below.

FIG. 7 shows a flowchart of one mode of pure water supply control according to the present embodiment.

As shown in FIG. 7, in this embodiment, first, in step 701, the amount of pure water stored in the electrolytic tank 2 is detected. Here, the stored amount (water level) of pure water in the electrolytic tank 2 is detected using the electrolytic tank water level meter 2L.

Next, in step 702, it is determined whether or not the water level in the electrolytic tank 2 is below a predetermined value based on the water level detection signal in step 701. If it is determined that the water level is equal to or lower than the predetermined value (if “Yes” is determined in step 702), the process of step 703 is performed. If the water level is not equal to or less than the predetermined value (if “No” is determined in step 702), the processing in step 701 and the subsequent steps is performed again.

Next, in step 703, the driving of the makeup water pump 6 is started based on the judgment in step 702. That is, the makeup water pump 6 is driven to move the pure water tank 3 from the pure water tank 3 through the pure water supply pipe.
Replenish pure water.

Next, in step 704, the amount of pure water stored in the electrolytic tank 2 is detected. Here, as in step 701, the stored amount (water level) of pure water in the electrolytic tank 2 is detected using the electrolytic tank water level meter 2L.

Next, in step 705, it is determined whether or not the water level in the electrolytic tank 2 is within a predetermined range based on the water level detection signal in step 704. If it is determined that the water level is within the predetermined range (if “Yes” is determined in step 705), then the process of step 706 is performed. When it is determined that the water level is not within the predetermined range (when it is determined “No” in step 705), while the makeup water pump 6 is driven, the processes in and after step 704 are performed again. Processing is performed.

Next, in step 706, water supply from the pure water tank 3 to the electrolytic tank 2 is stopped based on the determination in step 705. That is, the makeup water pump 6 is stopped. Then, after step 706, the processes after step 701 are performed again.

The above steps 701 to 706
Is the basic pure water supply (supply) control in the hydrogen / oxygen supply system according to the present embodiment. In addition,
Although not particularly shown in FIG. 7, in the present embodiment, the pure water in the electrolytic tank 2 is circulated through the pure water circulation pipe section 7 provided as a closed circuit with respect to the electrolytic tank 2. , Water electrolysis device 1.

Specifically, in this embodiment, the pure water in the electrolytic tank 2 is circulated by the circulating water pump 8 provided in the pure water circulating pipe section 7, and the pure water circulating pipe section 7
Through the heat exchanger 9, polisher 10, and filter 11 provided in the water electrolysis apparatus 1.
6 is supplied with pure water. The pure water circulation pipe section 7 is also provided with a water quality alarm unit 12, a water temperature alarm unit 13, and a circulating water amount alarm unit.

In the present embodiment, pure water is supplied to the water electrolysis apparatus 1 through the pure water circulation pipe section 7 which is a closed circuit provided with various elements as described above. Water supply becomes possible. That is, the provision of the heat exchanger 9 makes it possible to perform heat exchange of pure water whose temperature has increased due to the heat generated by the water electrolysis device 1, so that the water electrolysis device 1 can be efficiently driven. Further, the provision of the polisher 10 makes it possible to supply pure water to the water electrolysis apparatus 1 in a state where the purity of pure water is increased. Further, by providing the filter 11, impurities contained in pure water can be removed and pure water can be supplied to the water electrolysis device 1. Further, in the present embodiment, since the water quality warning means 12 and the water temperature warning means 13 are provided, some troubles have occurred (or are likely to occur) in the heat exchanger 9, the polisher 10, and the filter 11 described above. Is detected), the heat exchanger 9, polisher 10, or filter 11 can be replaced before inappropriate (low purity or many impurities, etc.) pure water is supplied. It is. Further, in the present embodiment, since the circulating water amount warning means is provided, it is possible to prevent the amount of circulating water from being lower than the processing amount (predetermined processing amount), thereby preventing the electrolytic cell from being damaged. In other words, if the amount of water supplied to the electrolytic cell is insufficient, the flow of water in the electrolytic cell becomes uneven, and the solid electrolyte membrane may be damaged by local heat generation. Is provided, the decrease in the amount of circulating water can be detected in advance, and such a problem can be effectively solved. Therefore, according to the present embodiment, it is possible to continuously supply pure water having appropriate properties to the water electrolysis device 1. Also,
In the present embodiment, as described above, since a gas vent is provided at an appropriate position of the pure water circulation pipe section 7, oxygen gas in the pure water circulation pipe section 7 causes a problem in the circulation of the pure water. If necessary, degassing can be performed so as not to cause the generation.

As described above, in this embodiment, since the quality and temperature of pure water are controlled to supply pure water having appropriate properties to the water electrolysis apparatus 1, the life of the solid electrolyte membrane 102 is extended. In addition to being able to extend, the electrolysis efficiency in the water electrolysis device 1 can also be improved.

In the present embodiment, the pure water separated from the hydrogen gas in the hydrogen separation tank 4 can be reused through the pure water return pipe section 15 (and the pure water tank 3 and the like). (Can be supplied to the water electrolysis apparatus 1). In the present embodiment, as described above, the pure water tank 3 and the electrolytic tank 2 are connected by the pure water supply pipe 5, and the water electrolyzer 1 and the hydrogen separation tank 4 in the electrolytic tank 2 are connected to each other. The hydrogen separation tank 4 and the pure water tank 3 are connected by a hydrogen gas transfer pipe section 14 and the pure water return pipe section 15 is connected by a hydrogen gas transfer pipe section 14. In other words, the pure water tank 3, the electrolytic tank 2, and the hydrogen separation tank 4 are configured as a closed circuit by the pure water supply pipe 5, the hydrogen gas transport pipe 14, and the pure water return pipe 15. Hydrogen is dissolved in the pure water transported from the hydrogen separation tank 4 using the pure water return pipe section 15, and if the circulation in the closed circuit is continuously repeated, the dissolved rate becomes However, it is not preferable in terms of the system configuration. In other words, the pure water discharged from the hydrogen separation tank 4 contains dissolved hydrogen under the hydrogen generation pressure, and when this is returned to the pure water tank (supplementary water tank) 3 as it is, the pressure becomes large. Since the pressure is released to the atmospheric pressure, dissolved hydrogen corresponding to the differential pressure is gasified and released as the pressure is reduced. Then, hydrogen and air are mixed in the pure water tank 3, and the hydrogen concentration gradually increases, which may cause various problems. Therefore, the hydrogen / oxygen supply system according to the present embodiment is configured to dispose the gas scrubber 16 at a predetermined position of the pure water return pipe section 15 so as to solve the above-described problem.

Next, the current value control for the water electrolysis device 1 will be described. FIG. 8 shows a flowchart of one mode of the current value control according to the present embodiment.

As shown in FIG. 8, in this embodiment, first, in step 801, the hydrogen separation tank 4
The pressure of the hydrogen gas is detected by using the first pressure detecting means 25 provided in the first embodiment. Here, the pressure of the hydrogen gas in the hydrogen separation tank 4 is determined by the amount of hydrogen gas generated (the amount of hydrogen gas generated by the water electrolysis apparatus 1 and transferred to the hydrogen separation tank 4 via the hydrogen gas transfer pipe section 14). And the amount of hydrogen gas supplied (the amount of hydrogen gas supplied from the hydrogen separation tank 4 to the hydrogen gas use point via the hydrogen gas supply pipe 21).

Next, in step 802, it is determined whether or not the hydrogen gas pressure in the hydrogen separation tank 4 is lower than a predetermined value based on the pressure detection signal in step 801. This is because if the hydrogen gas pressure falls below a predetermined value, it becomes difficult to supply the required hydrogen gas. If it is determined that the hydrogen gas pressure is equal to or lower than the predetermined value (if “Yes” is determined in step 802), the process of step 803 is performed. If it is determined that the hydrogen gas pressure is not lower than the predetermined value (if “No” is determined in step 802), the processes in and after step 801 are performed again.

Next, in step 803, based on the judgment in step 802, a pressure detection signal is sent from the first pressure detection means 25 to the current value control means 28, and based on this pressure detection signal, An appropriate value of current is supplied from the value control unit 28 to the water electrolysis device 1. Here, an appropriate value is selected as the current to be supplied, depending on the required amount of supplied hydrogen gas (or hydrogen gas pressure or the like) and the hydrogen gas pressure fluctuation rate (hydrogen gas pressure fluctuation amount per unit time). And supplied to the water electrolysis device 1.

Next, in step 804, the pressure of the hydrogen gas is detected using the first pressure detecting means 25 provided in the hydrogen separation tank 4.

Next, in step 805, it is determined whether or not the hydrogen gas pressure in the hydrogen separation tank 4 is within a predetermined range based on the pressure detection signal in step 804. Then, if it is determined that the hydrogen gas pressure is within the predetermined range (if “Yes” is determined in step 805), then step 8 is performed.
Step 06 is performed. If it is determined that the hydrogen gas pressure is not within the predetermined range (if “No” is determined in Step 805), Step 80 is performed again.
Steps 3 and later are performed.

Next, in step 806, supply of current from the current value control means 28 to the water electrolysis device 1 is stopped based on the determination in step 805. After step 806, step 801 is performed again.
The following processing is performed.

In the present embodiment, as described above,
To show the steps 801 to 806,
An electric current is supplied to the water electrolysis device 1. That is,
In the present embodiment, the balance between the hydrogen gas generation amount and the hydrogen gas supply amount is detected by using the first pressure detection unit 25, and this detection signal is sent to the current value control unit 28 to respond to the detection signal. A current value (according to the pressure fluctuation) is supplied to the water electrolysis device 1. In the present embodiment, a rectifier or the like is used as the current value control means 28. That is, in the present embodiment, rectifier PID control is performed using a rectifier or the like.

On the other hand, in the prior art, the current is generally supplied to the water electrolysis apparatus when a constant current is supplied, or when the current is supplied based on ON / OFF control. In such a configuration, if an attempt is made to achieve an appropriate supply of hydrogen gas, a large tank for storing hydrogen gas (that is, a lower limit to an upper limit of the operating pressure) must be used in order to meet the required pressure of the hydrogen gas. Tank that can handle up to Then, in order to cope with the fluctuation of the used hydrogen gas pressure, it is necessary to store a predetermined amount of hydrogen gas in the tank in advance, and the used hydrogen gas pressure is shifted from the upper limit to the lower limit. When shifting, the hydrogen gas was released to the atmosphere or the like to meet the required hydrogen gas pressure. When the pressure of the hydrogen gas used shifts to the upper limit side, the current supply method (constantly constant or ON /
In the OFF control, etc., it is difficult to take a quick response (generation of hydrogen gas in response to a required increase in hydrogen gas pressure). Therefore, a predetermined amount (for example, 30 minutes to 2 hours at 100% operation) is always stored in the tank. (Amount of gas generated per minute) of hydrogen gas. Furthermore, in the case of alkaline water electrolysis, since the diaphragm (partition between the cathode chamber and the anode chamber) in the electrolysis cell is a porous body, when the output of the apparatus is reduced (below 15% or less), the cathode side and the anode side are reduced. Cannot be maintained uniformly, and hydrogen and oxygen may pass through the diaphragm and mix. Therefore, when the apparatus is stopped / restarted, it is necessary to purge the gas in the apparatus by purging it with N ₂ .

However, in the hydrogen / oxygen supply system according to the present embodiment, as described above, an appropriate current is supplied from the current value control means 28 to the water electrolysis apparatus 1 according to the amount of hydrogen gas used. With the configuration, it is possible to eliminate waste of the generated hydrogen gas and the current supplied to the water electrolysis device 1. Further, in the hydrogen / oxygen supply system according to the present embodiment, since pure water is supplied to the water electrolysis device 1 via the pure water circulation piping section 7 which is a closed circuit, the water electrolysis device 1 and the electrolytic tank 2
Can maintain relatively high hermeticity. That is, a predetermined hydrogen gas pressure can be obtained without driving the water electrolysis apparatus 1. Therefore, when there is no particular change in the pressure of hydrogen gas (when hydrogen gas is not used)
, The supply of current to the water electrolysis device 1 can be stopped. Therefore, in the hydrogen / oxygen supply system according to the present embodiment, the water electrolysis apparatus 1 can be driven in a range of 0 to 100% while supplying hydrogen or the like at an appropriate pressure.

In the hydrogen / oxygen supply system according to the present embodiment, the pressure of the hydrogen gas in the hydrogen separation tank 4 is detected by the first pressure detecting means 25, and the electrolytic tank is detected by the second pressure detecting means 35. 2 to detect the pressure of the oxygen gas in each of them, and the respective detection signals are used as differential pressure detecting means 45.
Sent to Then, based on a differential pressure signal between the hydrogen gas pressure and the oxygen gas pressure obtained by the differential pressure detecting means 45,
The hydrogen gas supply valve 22, the first relief valve 26, the oxygen gas supply valve 32, and the second relief valve 36
It is adjusted appropriately. In the hydrogen / oxygen supply system according to the present embodiment, it is possible to obtain a high-purity hydrogen gas by setting the hydrogen gas pressure to be slightly higher (about 0.05 to 0.1 MPa) than the oxygen gas pressure. It is configured as follows. Therefore, in the present embodiment, based on the above-described differential pressure signal, each valve 22 is set in the water electrolysis apparatus 1 so that the hydrogen gas pressure is about 0.05 to 0.1 MPa higher than the oxygen gas pressure. , 26, 32, and 36 are adjusted.

Further, in the present embodiment, each of the above-described relief valves 26 and 36 also functions as an interlock. That is, when any abnormality occurs in the differential pressure signal obtained by the differential pressure detecting means 45, in order to protect the solid electrolyte membrane 102 and the like, each relief valve 26,
By properly adjusting 36, at least one of the hydrogen gas and the oxygen gas is discharged through the respective relief piping portions 27 and 37. The interlock using the relief valves 26 and 36 is not limited to the above-described configuration. Therefore, for example, a spring relief valve or the like can be used as each of the relief valves 26 and 36, and when the pressure in each of the relief pipe portions 27 and 37 exceeds a predetermined pressure, each of the relief valves 26 and 36 may be configured to be appropriately opened.

In the hydrogen / oxygen supply system according to the present embodiment, the oxygen gas supply pipe section 31 provided for supplying oxygen gas from the electrolytic tank 2 to an oxygen use point (not shown) is provided. A hydrogen gas detecting means 34 is provided. The hydrogen gas detecting means 34 is configured using an on-line gas analyzer of a thermal conductivity type, a density type or the like in order to detect the hydrogen concentration in the oxygen gas. According to the present embodiment, by detecting the concentration of hydrogen gas in the oxygen gas in the oxygen gas supply pipe section 31, the occurrence of pinholes in the solid electrolyte membrane 102 can be detected. That is, according to the present embodiment, as described above, the pressure in the water electrolysis apparatus 1 is higher on the hydrogen gas generation side (the hydrogen generation chamber C side) than on the oxygen gas generation side (the oxygen generation chamber A side). When a pinhole or the like is generated in the solid electrolyte membrane 102, hydrogen gas is mixed from the hydrogen generation chamber C to the oxygen generation chamber A, and the oxygen gas mixed with the hydrogen gas is , Oxygen gas supply piping section 31
Is supplied via the. Therefore, according to the present embodiment, as shown in FIG.
Is provided with a hydrogen gas detecting means 34 to monitor the concentration of hydrogen gas in the oxygen gas, thereby early detecting damage (pinhole) or the like of the solid electrolyte membrane 102 and effectively performing system maintenance management. It becomes possible.

Further, in the hydrogen / oxygen supply system according to the present embodiment, the hydrogen / oxygen supply pipe 21 provided for supplying hydrogen gas from the hydrogen separation tank 4 to a hydrogen use point (not shown) is provided. , A hydrogen gas flow control means 24 is provided. This hydrogen gas flow control means 2
4 is configured using the flow rate detecting means 24A and the rated flow rate control valve 24B as described above. And
The flow rate detecting means 24A constantly monitors the flow rate of the hydrogen gas flowing in the hydrogen gas supply pipe section 21 and transmits an appropriate control signal to the rated flow rate control valve 24B according to the flow rate of the hydrogen gas. It is configured. That is, according to the present embodiment, even if a large amount of hydrogen gas is used on the downstream side of the hydrogen gas supply pipe section 21 (that is, at the location where the hydrogen gas is used), the hydrogen gas supply pipe section 21 Before the flowing hydrogen gas exceeds the rated flow rate, the flow rate detecting means 2
A control signal is sent from 4A to the rated flow control valve 24B, and the rated flow control valve 24B is adjusted so that hydrogen gas having a flow rate higher than the rated flow does not flow. Therefore, according to the present embodiment, no matter how the amount of hydrogen gas used on the downstream side of the hydrogen gas supply pipe unit 21 fluctuates,
Since the hydrogen gas having a flow rate higher than the rated flow does not flow through the hydrogen gas supply pipe section 21, the quality of the hydrogen gas can be kept constant. Such hydrogen gas flow control means 24
According to the configuration having (1), it is possible to effectively prevent problems when the user uses the buffer tank or the like. Specifically, in the case of using a buffer tank, the amount of hydrogen used may fluctuate significantly between normal times and peak times. In such a case, if the hydrogen / oxygen supply system is configured in accordance with the usage amount at the peak, the capacity becomes large, the operation rate decreases, and the economic efficiency is poor. For this reason, the buffer tank pressure is used with a certain width (for example,
It is used in a width of 0.9 MPa to 0.4 MPa).
During this time, gas exceeding the rated generation amount of the water electrolysis device 1 is used. In such a configuration, in order to perform the rated operation of the water electrolysis apparatus 1, it is necessary to control the flow rate so as to prevent gas exceeding the rated value from flowing as shown in the present embodiment. Thereby, the water electrolysis apparatus 1 can continue to operate stably, and the gas property (pressure and the like) at the inlet of the dehumidifier at the subsequent stage can be controlled to be constant, so that the supply gas quality can be kept constant. Further, with such a configuration, it is possible to prevent the water electrolysis device (electrolysis cell) 1 from being used beyond its performance, so that the life of the system can be extended.

In the hydrogen / oxygen supply system according to the present embodiment, a hydrogen gas transfer valve 18 is provided in the hydrogen gas transfer pipe section 14 provided between the water electrolysis device 1 and the hydrogen separation tank 4. In addition, a bypass pipe section 19 is provided to bypass the hydrogen gas transfer valve 18 on the hydrogen gas transfer pipe section 14. The bypass pipe 19 is provided with a check valve 20. Here, the check valve 20 is configured not to open when a pressure equal to or higher than a predetermined value does not act, so that hydrogen gas does not flow from the water electrolysis device 1 to the hydrogen separation tank 4. That is, in the present embodiment, a predetermined value or more (for example,
When a pressure of 0.1 MPa or more is applied, the check valve 20 is opened for the first time, and hydrogen gas flows from the water electrolysis apparatus 1 to the hydrogen separation tank 4 via the bypass pipe 19. Have been. Therefore, according to the hydrogen / oxygen supply system according to the present embodiment, even if some trouble occurs in the hydrogen gas transfer valve 18 and the hydrogen gas does not flow through the hydrogen gas transfer pipe section 14, the above-described state is obtained. As described above, when the pressure equal to or more than the predetermined value acts on the bypass pipe portion 19, the transfer of the hydrogen gas is performed via the check valve 20. Therefore, according to the present embodiment, even if a failure occurs in the hydrogen gas transfer valve 18, the check valve 20 is opened before the pressure at that time flows back to the water electrolysis device 1, and the hydrogen gas transfer pipe section is opened. 14, the hydrogen gas can be appropriately circulated through the bypass pipe section 19 and the check valve 20, so that the solid electrolyte membrane 102 constituting the water electrolysis apparatus 1 is effectively prevented from being damaged. be able to.

Further, the hydrogen / oxygen supply system according to the present embodiment is configured so that the gas pressure and the water level in each of the tanks 2 and 4 can be controlled to predetermined values using various detecting means and the like. . Specifically, the electrolytic tank 2
Is controlled using a second pressure control means 35, a differential pressure detection means 45, a second relief valve 36, and the like so that the tank pressure becomes a predetermined value. The water level in the tank is controlled to a predetermined value using the water pump 6. The hydrogen separation tank 4 includes a first pressure control unit 25, a differential pressure detection unit 45,
And the pressure in the tank is controlled to be a predetermined value using the first relief valve 26 and the like, and the water level in the tank is controlled to be the predetermined value using the hydrogen separation tank water level meter 4L and the pure water discharge valve 4A. Have been. Further, the pressures in the oxygen generation chamber A and the hydrogen generation chamber C in the water electrolysis apparatus 1 are also controlled to have a predetermined value as described above. In the present embodiment, as described above, each gas pressure and the water level in each of the tanks 2 and 4 can be controlled to be a predetermined value. That is, the hydrogen / oxygen supply system according to the present embodiment is configured to be operable based on certain conditions. Therefore,
Since the hydrogen / oxygen supply system according to the present embodiment can basically be operated under certain conditions, high-quality gas (particularly, high-purity hydrogen gas) can be obtained. In addition, since operation is possible under certain conditions, stress is less likely to be applied to each component of the system, and it is possible to extend the life of the entire system as well as each component. Becomes In addition,
As described above, in the present embodiment, not only the gas pressure control but also the water level control is performed, so that the gas pressure control can be performed more easily than when only the gas pressure control is performed. .

In this embodiment, the case where the hydrogen / oxygen supply system is constituted by using one water electrolysis apparatus 1 has been described. However, the present invention is not limited to this constitution. A hydrogen / oxygen supply system may be configured using the water electrolysis apparatus 1 of the first embodiment. At this time, each water electrolysis apparatus 1 may be provided with an electrolysis tank 2 and the like, and each water electrolysis apparatus 1 may be blocked to form a hydrogen / oxygen supply system. According to such a configuration, a failure of the water electrolysis device 1 or the like can be detected not only for the entire system but also for each block. Therefore, even if a failure or the like occurs in any part of the system, Replacement or the like can be performed by stopping only the failed block. Therefore, in the case of a hydrogen / oxygen supply system that realizes such a block, even if a failure occurs in the water electrolysis apparatus 1 or the like, it is not necessary to stop the entire system, so that stable gas supply can be achieved. It can be a feasible system.

Further, in this embodiment, the hydrogen / oxygen supply system whose main purpose is to obtain hydrogen gas (to obtain high-purity hydrogen gas) has been described, but the present invention is limited to this configuration. Not what you need,
A system whose main purpose is to obtain high-purity oxygen gas may be used. That is, in the present embodiment, the pressure of the hydrogen gas is set slightly higher in order to prevent the oxygen gas from being dissolved in the hydrogen gas. The hydrogen / oxygen supply system may be configured by setting the pressure slightly higher. Also,
The oxygen gas supply pipe may be provided with a flow rate detecting means and a flow rate controlling means.

In the hydrogen / oxygen supply system according to the present embodiment, the piping for connecting each element is not particularly described. However, in the present invention, a fluid containing a large amount of oxygen gas is conveyed. A hydrogen / oxygen supply system is configured using pipes having appropriate characteristics for a pipe section (O ₂ rich line) and a pipe section (H ₂ rich line) for transporting a fluid containing a large amount of hydrogen gas. May be. Specifically, for example, an O ₂ rich line is formed by subjecting a stainless steel surface to electrolytic polishing treatment and then heating in an oxidizing atmosphere to form a colored oxide film of a metal oxide mainly composed of an iron-based oxide. It is preferable to use stainless steel formed on the surface (see JP-A-10-140322). Such stainless steel has a characteristic that the amount of metal ions eluted with respect to a fluid containing a large amount of oxygen gas is extremely small. Therefore,
If an O ₂ rich line is formed using such stainless steel, a system capable of effectively preventing unnecessary elution of metal ions into oxygen gas can be realized. In addition, for example, an H ₂ rich line cleans the stainless steel surface, heat-treats it in an oxidizing atmosphere to form a colored oxide film on the cleaned surface, and then dissolves the colored oxide film. Removed stainless steel
It is preferable to use the configuration described in Japanese Patent Application Laid-Open No. 0-25561). Such stainless steel has a characteristic that the amount of metal ions eluted with respect to a fluid containing a large amount of hydrogen gas is extremely small. Therefore, if an H ₂ rich line is formed using such stainless steel, it is possible to realize a system capable of effectively preventing unnecessary elution of metal ions into hydrogen gas.

Further, in the present embodiment, the electrolytic tank 2 is made of the same stainless steel as the O ₂ rich line not only in the above-mentioned piping section but also in each of the tanks 2 and 4, and the hydrogen separation tank is used. Is preferably formed using the same stainless steel as the H ₂ rich line. According to this preferred configuration, the tanks 2 and 4 also
Since elution of metal ions can be prevented, the use of such a tank makes it possible to realize a system capable of supplying high-purity gas.

In the present invention, it is preferable that oxygen gas generated by the own system is used to bubble the pure water in the pure water tank 3. In the hydrogen / oxygen supply system according to the present embodiment, air (particularly nitrogen) is the only impurity, and such air mainly enters the system via the pure water tank 3. Therefore, if such air is eliminated, it becomes possible to obtain hydrogen or oxygen with higher purity. Therefore, in the present invention, it is preferable that the pure water tank 3 be bubbled with oxygen gas in order to eliminate the air as impurities. At this time, for bubbling, it is possible to use oxygen gas or the like which should be originally relieved. According to this configuration, a hydrogen / oxygen supply system capable of obtaining high-purity hydrogen gas or oxygen gas without using a new facility or the like is realized by using oxygen gas or the like which should be originally relieved. can do.

Further, in the present embodiment, the so-called “high pressure type” hydrogen / oxygen supply system in which the water electrolysis apparatus 1 is accommodated in an electrolysis tank (a tank that also functions as an oxygen separation tank) 2 has been described. The present invention is not limited to this configuration, and may be configured as a “low pressure type” system as needed. Specifically, the water electrolysis apparatus 1 may be installed without being housed in a tank or the like, and an oxygen separation tank may be provided on the oxygen supply side of the water electrolysis apparatus 1. Here, FIG. 9 shows an example of a “low pressure type” hydrogen / oxygen supply system. In FIG. 9, the same components as those described with reference to FIG. 1 and the like are denoted by the same reference numerals. In the hydrogen / oxygen supply system shown in FIG. 9, pure water is supplied to the electrolytic cell 1 provided outside the oxygen separation tank 2 via the pure water circulation pipe section 7, and the electrolytic cell is supplied to the electrolytic cell 1. In this case, electric power (current) is supplied via the current value control means 28 in the same manner as in the “high pressure type” hydrogen / oxygen supply system described with reference to FIG. Further, the hydrogen gas generated in the electrolytic cell 1 is transferred to a hydrogen separation tank (not shown) via the hydrogen gas transfer pipe section 14. Further, the oxygen gas generated in the electrolysis cell is
It is transported to the oxygen separation tank 2. The “low pressure type” hydrogen / oxygen supply system shown in FIG. 9 is configured as described above, and the point where the electrolysis cell 1 is provided outside the tank (and the Presence etc.)
Except for the above, it basically has the same configuration as the “high pressure type” hydrogen / oxygen supply system described with reference to FIG. That is, the “low pressure type” shown in FIG.
As in the case of the "high-pressure type", various sensors and the like can be provided, and the above-described various controls can be realized. Therefore, the same effects as those of the "high-pressure type" can be obtained.

In this specification, the term “predetermined value” refers not only to a case where a predetermined value is indicated but also to a predetermined range (a value within a certain range or a plurality of values within the range). This is a concept that includes the case where

[0097]

As described above, according to the present invention,
Obtaining a hydrogen / oxygen supply system configured to effectively maintain the quality of product gas without applying unnecessary stress to the solid electrolyte membrane (that is, properly protecting the solid electrolyte membrane). Can be. Further, according to the present invention, it is possible to obtain a hydrogen / oxygen supply system configured to be able to effectively maintain the quality of a generated gas (supply gas) by appropriately controlling flowing pure water and generated gas. it can.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram of a hydrogen / oxygen supply system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of an electrolysis cell constituting a water electrolysis apparatus constituting the hydrogen / oxygen supply system according to FIG.

FIG. 3 is a sectional view showing a main part of a section taken along line II-II of FIG. 2 (a);

FIG. 4 is a sectional view showing a main part of a section taken along line III-III of FIG. 2 (a);

FIG. 5 is an exploded perspective view of an electrode plate unit constituting the electrolytic cell according to the embodiment.

FIG. 6 is a flowchart when the hydrogen / oxygen supply system according to the present embodiment is operated.

FIG. 7 is a flowchart showing one mode of pure water supply control according to the embodiment;

FIG. 8 is a flowchart showing one mode of current value control according to the embodiment;

FIG. 9 shows a part of a schematic system diagram of a hydrogen / oxygen supply system according to another embodiment of the present invention.

[Explanation of symbols]

1: water electrolysis device (electrolysis cell), 2: electrolysis tank, 2L ...
Electrolysis tank water level meter, 3 ... Pure water tank, 3A ... Pure water supply valve, 3L ... Pure water tank water level meter, 4 ... Hydrogen separation tank,
4A: Pure water discharge valve, 4L: Hydrogen separation tank water level meter,
5 ... pure water supply piping, 6 ... supplementary water pump, 7 ... pure water circulation piping, 8 ... circulating water pump, 9 ... heat exchanger, 10 ... polisher, 11 ... filter, 12 ... water quality warning means, 13 ... Water temperature alarm means, 14: hydrogen gas transfer pipe, 15: pure water return pipe, 16 ... gas scrubber, 17: hydrogen discharge pipe, 18 ... hydrogen gas transfer valve, 19: bypass pipe, 20 ... check valve, 21 ... hydrogen gas supply piping section, 22 ...
Hydrogen gas supply valve, 23 ... hydrogen gas dehumidifying means, 24 ...
Hydrogen gas flow rate control means, 24A ... flow rate detection means, 24B
... Rated flow control valve, 25 ... First pressure detection means, 2
6 ... first relief valve, 27 ... first relief piping section,
28: current value control means, 31: oxygen gas supply pipe section, 3
2 ... Oxygen gas supply valve, 33 ... Oxygen gas dehumidifying means, 3
4 ... hydrogen gas detecting means, 35 ... second pressure detecting means, 3
6 ... second relief valve, 37 ... second relief pipe part,
45 ... Differential pressure detecting means, 94 ... Oxygen gas transfer piping section 102 ... Solid electrolyte membrane, 103 ... Electrode plate unit, 10
4 ... electrode plate, 104a ... plate part (inner part), 104b
... Peripheral part, 105 ... Porous feeder, 106, 106a,
106b, 106c, 106d: spacer, 107: sealing member, 109, 109a, 109b, 109c, 1
09d: insulating sheet, 110: shim, 111: groove (groove for seal member), 112a: ridge (outward ridge), 112
b: ridge (inner ridge), 113: hole for oxygen, 114:
Holes for hydrogen, 115, 116 ... holes for pure water, 117 ... O-ring grooves, 118 ... grooves for hydrogen, 119 ... grooves for oxygen, 120 ...
Groove for pure water, 120a ... recess, 120b ... small groove, 121 ...
O-ring, 122: end plate, 123: tightening bolt, 124
... Nut, 125 ... Belleville spring A ... Oxygen generation chamber, C ... Hydrogen generation chamber

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shinji Miyazawa 7-4 Takamaru, Tarumi-ku, Kobe A-203 (72) Inventor Teruyuki Morioka 934-4, Tsuchiyama, Hiraoka-cho, Kakogawa-shi (72) Inventor Sueki Nakao Osaka 1-4-2 Mitsuya Minami, Yodogawa-ku (72) Inventor Yu Hosomi 2-26-3-503, Uozumi-cho, Akashi-shi (72) Inventor Masahiro Uemura 700-8 Nagasago, Noguchi-cho, Kakogawa-shi F term (reference) 4K021 AA01 BA02 BC01 CA09 CA11 CA13 CA15 DB02 DB04 DB28 DB43 DB49 DB53 DC01 DC03

Claims (6)

[Claims] An electrolytic cell separated on the anode side and the cathode side by a solid electrolyte membrane, wherein pure water is supplied to the electrolytic cell to generate hydrogen on the cathode side, and hydrogen is generated on the anode side. Oxygen has been generated, and in a hydrogen / oxygen supply system configured so that at least one of the hydrogen and oxygen can be supplied to a point of use, the cathode side has a higher pressure than the anode side, or the anode side has a higher pressure than the cathode side. Is set to one of high pressures.
Oxygen supply system. 2. A first pressure detecting means capable of detecting a pressure of the hydrogen supplied through the cathode side of the electrolytic cell, and a first pressure detecting means detecting a pressure of the oxygen supplied through the anode side of the electrolytic cell. A second pressure detecting means capable of detecting pressure, a pressure detection signal obtained by the first pressure detecting means and a pressure detection signal obtained by the second pressure detecting means are compared with a predetermined difference. A differential pressure detecting means capable of generating a pressure signal, a first relief mechanism capable of adjusting the pressure of the hydrogen based on the differential pressure signal, and a second relief mechanism capable of adjusting the pressure of the oxygen based on the differential pressure signal 2. The hydrogen / oxygen supply system according to claim 1, wherein the anode pressure and the cathode pressure in the electrolytic cell are adjusted using the first and second relief mechanisms. 3. . 3. The first relief mechanism includes: a first relief pipe provided in a hydrogen separation tank storing the hydrogen; and a differential pressure signal provided in the first relief pipe. And a second relief mechanism is provided in an oxygen separation tank that stores the oxygen generated in the electrolytic cell. 3. The hydrogen / oxygen supply according to claim 2, wherein the hydrogen / oxygen supply is configured by using a relief piping section provided in the second relief piping section and a second relief valve that can be controlled based on the differential pressure signal provided in the second relief piping section. system. 4. A pure water circulating pipe portion for accommodating an electrolytic cell in the oxygen separation tank and circulating pure water in the oxygen separation tank without contacting outside air is provided in the oxygen separation tank. The hydrogen / oxygen supply system according to claim 3, wherein the pure water is supplied to the anode side of the electrolytic cell via the pure water circulation pipe. 5. A hydrogen gas supply pipe section for supplying the hydrogen, and a hydrogen gas flow rate control means provided in the hydrogen gas supply pipe section, wherein the hydrogen gas flow rate control means includes a flow rate detection means. And a rated flow control valve, and the supply flow rate of the hydrogen is detected by the flow detection means, and the rated flow control valve is adjusted based on a detection signal in the flow detection means, The hydrogen / oxygen supply system according to any one of claims 1 to 4, wherein the hydrogen flowing through the hydrogen gas supply pipe is controlled to have a rated flow rate. 6. A pure water tank for supplying the pure water to the electrolytic cell, wherein the pure water in the pure water tank uses the oxygen generated in the electrolytic cell. The hydrogen / oxygen supply system according to claim 1, wherein bubbling is performed.