JP4751594B2 - Hydrogen / oxygen gas generator and operation method thereof - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a hydrogen / oxygen gas generator, and more specifically, hydrogen gas pressurized by electrolyzing pure water using a water electrolysis apparatus separated into an anode part and a cathode part by a solid electrolyte membrane. The present invention relates to a hydrogen / oxygen gas generator for supplying oxygen and oxygen gas and an operation method thereof.

As a water electrolysis apparatus constituting the hydrogen / oxygen gas generating apparatus, one using an electrolytic cell provided with a solid electrolyte membrane as a member serving as an electrolyte is conventionally known (see Patent Document 1).
Such an electrolytic cell is referred to as a solid polymer electrolyte membrane / electrode assembly membrane (hereinafter referred to as “solid electrolyte membrane”) in which electrode catalyst layers (anode side and cathode side catalyst layers) are provided on both sides of the solid polymer electrolyte membrane. ), An electrode plate (anode side and cathode side electrode plate) provided to sandwich the solid electrolyte membrane, and a power supply body (anode side and cathode side power supply body) provided between the solid electrolyte membrane and the electrode plate ) Etc. to be separated into an anode part and a cathode part.

In the electrolysis cell according to the above prior art, by supplying pure water to the anode part and energizing the electrode plate, the pure water is decomposed mainly in the anode side catalyst layer and oxygen is generated. . The H ⁺ ions generated simultaneously with oxygen move in the solid electrolyte membrane by the action of the electric field, so that electrons are obtained in the cathode side catalyst layer and hydrogen is generated at the cathode portion.
The generated hydrogen and oxygen are respectively taken out as hydrogen gas and oxygen gas by a gas-liquid separation device called a separation tank, and used after dehydration.
The hydrogen / oxygen gas generator using the above electrolytic cell can generate high-pressure hydrogen gas and oxygen gas without using a gas compressor, and the pressure of these gases is controlled by the applied power. it can. Furthermore, since these gases can be continuously generated, they are widely used as an on-site hydrogen / oxygen supply source instead of a gas cylinder.
In particular, in recent years, it has come to be widely used for applications that require a large amount of higher-pressure hydrogen gas, such as hydrogen stations.

  By the way, it is known that hydrogen and oxygen have a small molecular size and permeate a polymer film. The amount of hydrogen or oxygen molecules that permeate the polymer film or the like is proportional to the partial pressure of hydrogen or oxygen and inversely proportional to the thickness of the permeating polymer film. For this reason, in such a hydrogen / oxygen gas generator, particularly in a hydrogen / oxygen gas generator used in a hydrogen station, for example, when the operation is stopped, the gas in the separation tank is kept in a pressurized state. There is a possibility that both gases will be mixed by gas permeating to the anode side of the solid electrolyte membrane or oxygen gas permeating to the cathode side. Therefore, in such a hydrogen / oxygen gas generator, the pressure in the separation tank is released to about atmospheric pressure when the operation is stopped. For this reason, at the start of operation, it takes time for the separation tank to reach a desired pressure, which has a problem of reducing the operation efficiency. In order to prevent this, it may be possible to suppress the permeation of hydrogen and oxygen by increasing the thickness of the solid electrolyte membrane, but in that case, the electrical resistance value of the solid electrolyte membrane increases, so Energy loss due to heat is increased, resulting in a problem of lowering operation efficiency. That is, it is difficult for the conventional hydrogen / oxygen gas generator to prevent the hydrogen gas or oxygen gas from passing through the solid electrolyte membrane and mixing both gases while suppressing a decrease in operating efficiency. Have a problem.

JP-A-8-193287

  In view of the above problems, an object of the present invention is to provide hydrogen / oxygen gas capable of preventing hydrogen gas or oxygen gas from passing through the solid electrolyte membrane and mixing both gases while suppressing a decrease in operating efficiency. It is to provide a generator.

  In order to solve the above problems, the present invention comprises an anode part provided with a positive electrode, a cathode part provided with a negative electrode, and a solid electrolyte membrane separating the anode part and the cathode part, A water electrolysis cell that is electrolyzed and oxygen gas is generated at the anode part and hydrogen gas is generated at the cathode part, so that the hydrogen gas generated at the cathode part can be taken out in a pressurized state. A hydrogen separation tank that is communicated with the cathode part, into which hydrogen gas and water in the cathode part are introduced and gas-liquid separated in a pressurized state, and oxygen gas generated in the anode part can be taken out in a pressurized state And a hydrogen / oxygen gas generator comprising an oxygen separation tank that is communicated with the anode part and into which oxygen gas and water in the anode part are introduced and gas-liquid separated in a pressurized state. And at least one of the oxygen separation tanks When the operation of the water electrolysis cell is stopped, the gas stored in the inside is discharged and pure water is injected so that the inside is filled with pure water and can be in a pressurized state. A hydrogen / oxygen gas generator characterized by being provided with a gas discharge mechanism and a water injection mechanism, an anode part with a positive electrode, a cathode part with a negative electrode, the anode part and the cathode part A water electrolysis cell having a solid electrolyte membrane for separating water and electrolyzing water to generate oxygen gas at the anode part, hydrogen gas at the cathode part, and at the cathode part The hydrogen gas and water in the cathode part are introduced into a hydrogen separation tank so that the hydrogen gas can be taken out in a pressurized state, gas-liquid separation is performed in the pressurized state, and the oxygen gas generated in the anode part is removed. Oxygen gas and water in the anode part so that it can be taken out under pressure An operation method of a hydrogen / oxygen gas generating device that is introduced into an oxygen separation tank and performs gas-liquid separation in a pressurized state, and when the operation of the water electrolysis cell is stopped, the hydrogen separation tank and the oxygen separation tank Hydrogen / oxygen gas characterized in that in at least one of the separation tanks, the gas stored in the interior is discharged and pure water is injected, and the interior of the separation tank is filled with pure water to be in a pressurized state. And a method of operating the generator.

  According to the present invention, since the hydrogen / oxygen gas generator includes the gas discharge mechanism and the water injection mechanism in at least one of the hydrogen gas separation tank or the oxygen gas separation tank, When the operation is stopped, the gas can be discharged from the separation tank and filled with pure water, and hydrogen gas or oxygen gas can be prevented from passing through the solid electrolyte membrane and mixing of both gases. In addition, since the inside of the separation tank can be maintained in a pressurized state by the filled pure water, the time until the gas reaches a desired pressure at the time of starting can be shortened, and the hydrogen / oxygen gas generator It can suppress that operating efficiency falls.

A hydrogen / oxygen gas generator according to a preferred embodiment of the present invention will be described below with reference to a schematic system diagram shown in FIG.
The hydrogen / oxygen gas generating apparatus according to the present embodiment is centered on a water electrolysis apparatus 1 configured using an electrolysis cell, and a pure water tank 3 for supplying pure water to the water electrolysis apparatus 1 and water electrolysis. A hydrogen separation tank 4 for storing and supplying hydrogen generated in the apparatus 1 is provided, and the hydrogen gas in the hydrogen separation tank 4 is accommodated when the operation of the hydrogen / oxygen gas generator is stopped. A water injection tank 50 for injecting pure water is further provided above the hydrogen separation tank 4.

  In the hydrogen / oxygen gas generating apparatus according to the present embodiment, pure water is supplied via a pure water supply piping section 5 to supply pure water to an oxygen separation tank (electrolysis tank) 2 provided with a water electrolysis apparatus 1. A water tank 3 is connected. The pure water supply pipe section 5 is provided with a replenishing water pump 6 for replenishing (supplying) the pure water stored in the pure water tank 3 to the electrolytic tank 2. 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 the 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 water. And 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 meter 3L. In the electrolytic tank 2, an electrolytic tank water level meter 2L that detects the amount of pure water stored in the electrolytic tank 2 is provided, and 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 drive 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 circulation pipe section 7 for circulating and reusing the pure water in the electrolytic tank 2, and the pure water circulation pipe section 7 is provided in the electrolytic tank 2. After taking out pure water out of the electrolytic 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 apparatus 1 (electrolytic cell constituting it). The pure water circulation pipe section 7 includes a circulating water pump 8 for circulating pure water, a heat exchanger 9 for heat exchange of pure water (to reduce the temperature of pure water), pure water A polisher 10 for increasing the purity of the water, a filter 11 for filtering pure water, and the like are provided. As the polisher 10, for example, an ion exchange resin is used. Further, the pure water circulation pipe section 7 monitors the water quality (electric conductivity) of the pure water in the pure water circulation pipe section 7 and, if necessary, has a predetermined electric conductivity (for example, 0.2 μS / cm)), the temperature of the pure water in the water quality alarm means 12 for issuing an alarm and the pure water circulation pipe section 7 is monitored, and when necessary (a predetermined temperature range (for example, 40 to 90)). Water temperature alarm means 13 is provided to issue an alarm when the temperature exceeds (° C.). Moreover, since the pure water circulated through the pure water circulation pipe section 7 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 oxygen gas is discharged, oxygen gas accumulates in the circulating water pump 8, the polisher 10, or the filter 11 provided in the pure water circulation pipe section 7, and such oxygen gas circulates in pure water. May cause problems. Therefore, in this embodiment, gas venting 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 apparatus 1 in the electrolysis tank 2 is sent to the hydrogen separation tank 4 through the hydrogen gas transport piping section 14 together with some pure water. The hydrogen gas transfer piping unit 14 is provided with a valve 18 and a bypass piping unit 19 to bypass the valve 18 on the hydrogen gas transfer piping unit 14. The bypass piping unit 19 is provided with a check valve 20.

The hydrogen separation tank 4 includes a reflux pipe 54 for discharging the hydrogen gas from the hydrogen separation tank 4 when the operation of the hydrogen / oxygen gas generator is stopped, and a pure water injection pipe 52 for injecting pure water into the hydrogen separation tank 4. It has been.
The reflux pipe 54 communicates the upper part of the hydrogen separation tank 4 with the upper part of the water injection tank 50 and includes a reflux valve 54A. The flow of hydrogen gas in the reflux pipe 54 is controlled by opening and closing the reflux valve 54A.
The pure water injection pipe 52 communicates the lower part of the hydrogen separation tank 4 and the lower part of the water injection tank 50 and includes an injection water control valve 52A. The flow of pure water in the pure water injection pipe 52 is controlled by opening and closing the injection water control valve 52A.
The hydrogen separation tank 4 is provided with a hydrogen separation tank water level meter 4L that detects the amount of pure water stored in the hydrogen separation tank 4. The detection signal obtained by the hydrogen separation tank water level meter 4L The pure water is sent from the separation tank 4 to the pure water tank 3 to the pure water discharge valve 4A of the pure water return pipe section 15 provided to return the pure water (to discharge and reuse the pure water). If the hydrogen separation tank water level meter 4L determines that a predetermined amount or more of pure water is stored in the hydrogen separation tank 4, the 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 through the pure water return pipe section 15 is slightly dissolved with hydrogen. Therefore, in the present embodiment, a gas scrubber 16 is disposed in the pure water return pipe section 15, and a hydrogen release pipe section 17 is connected to the gas scrubber 16. Therefore, in this 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 via a hydrogen gas supply piping unit 21 to a hydrogen gas use location (not shown). 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 dehumidifying means 23 for dehumidifying the hydrogen gas, and a hydrogen gas flow rate maintained at a rated flow rate. And a hydrogen gas flow rate control means 24 is provided. The hydrogen gas flow rate control means 24 is obtained by the flow rate detection means 24A for detecting the flow rate of the hydrogen gas flowing through the hydrogen gas supply pipe section 21 via the hydrogen gas supply valve 22, and the flow rate detection means 24A. The rated flow rate control valve 24B that can be controlled based on the detection signal is used. 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 circulating hydrogen gas inside the hollow fiber membrane and circulating dry air outside the hollow fiber membrane. Although not particularly shown in FIG. 1, when trying to obtain hydrogen gas of higher purity (for example, 6N (99.9999) or more), the downstream side of the hydrogen gas dehumidifying means 23 or the hydrogen gas A configuration in which a purifier configured using molecular sieves such as zeolite and activated alumina is used instead of the dehumidifying means is preferable. Since the present embodiment is configured to dehumidify the hydrogen gas by the hydrogen gas dehumidifying means 23 (or purifier) using a hollow fiber membrane or the like, it is not necessary to use a palladium purifier or the like that is necessary in the prior art. . If necessary, these purifiers can be used in combination. The hydrogen gas supply valve 22 is controlled based on the pressure of the hydrogen separation tank 4 as will be described later. For this purpose, the hydrogen separation tank 4 is provided with first pressure detection means 25.
Further, the hydrogen separation tank 4 is provided with a first relief pipe portion 27 having a first relief valve 26. The first relief valve 26 is configured to be controlled based on the pressure in the electrolytic tank 2 and the pressure in the hydrogen separation tank 4 as will be described later.

The water injection tank 50 has an internal volume sufficient to store an amount of pure water that can fill the hydrogen separation tank 4.
Furthermore, a hydrogen gas discharge pipe 53 that communicates between the upper part of the water injection tank 50 and the upstream side of the hydrogen gas supply valve 22 of the hydrogen gas supply pipe 21 is provided. A hydrogen gas discharge valve 53A for performing control is provided.

  Further, the oxygen gas generated in the water electrolysis apparatus 1 in the electrolytic tank 2 is stored in the upper part of the electrolytic tank 2, and the oxygen gas use location (not shown) is passed through the oxygen gas supply piping unit 31. Is transported and supplied. An oxygen gas supply valve 32 that adjusts the supply amount of oxygen gas, an oxygen gas dehumidifying means 33 for dehumidifying oxygen gas, and an oxygen gas supply piping unit 31 are circulated in the oxygen gas supply piping unit 31. Hydrogen gas detecting means 34 is provided for detecting the hydrogen concentration in the oxygen gas. Here, the oxygen gas supply valve 32 is controlled based on the pressure of the electrolytic tank 2 and the pressure of the hydrogen separation tank 4 as described later. For this purpose, the electrolytic tank 2 is provided with second pressure detection means 35. Moreover, the oxygen gas dehumidifying means 33 is configured using, for example, a hollow fiber membrane. The oxygen gas dehumidifying means 33 dehumidifies oxygen gas by circulating oxygen gas inside the hollow fiber membrane and circulating dry air outside the hollow fiber membrane. Although not shown, a flow rate control means such as an adjustment valve may be provided in the oxygen gas flow path as in the case of hydrogen gas.

  Furthermore, the electrolytic tank 2 is provided with a second relief pipe portion 37 having a second relief valve 36. And this 2nd relief valve 36 is comprised so that it may control based on the pressure of the electrolytic tank 2, and the pressure of the hydrogen separation tank 4 so that it may mention later.

  In this embodiment, the detection value of the first pressure detection means 25 and the detection value of the second pressure detection means 35 are compared, and a predetermined signal is sent to various valves 22, 26, 32, 36. A differential pressure detecting means 45 that can be fed is provided. Further, in the present embodiment, a current value control unit 28 that receives a pressure detection signal from the first pressure detection unit 25 and supplies an appropriate current to the water electrolysis apparatus 1 is provided.

  As described above, the hydrogen / oxygen gas generating apparatus according to the present embodiment is configured using the water electrolysis apparatus 1, and the water electrolysis apparatus 1 supplies hydrogen by supplying pure water and a predetermined current. And an electrolysis cell that can generate oxygen. Next, the structure of this electrolytic cell will be described with reference to the drawings.

  FIG. 2 is a schematic cross-sectional view of an example of a water electrolysis cell constituting the water electrolysis apparatus. In FIG. 2, 62 is an electrode plate, and 63 is a solid electrolyte membrane. 64 is a porous power supply, 65 is a gasket, and 66 is a protective sheet. Reference numeral 67 denotes a hydrogen gas extraction path, 67a a hydrogen gas extraction path, 68 an oxygen gas extraction path, and 68a an oxygen gas extraction path.

  Reference numerals 69 and 69 denote end plates. Although the pure water supply path is not shown in this figure, it is formed by the same configuration as the oxygen gas extraction path 68. The above-described components are fastened with bolts 60 via the insulating plate 61 so as to be sandwiched between the both end plates 69, 69, thereby forming an electrolysis cell (water electrolysis device 1). In addition, the part of the porous power supply body 64 becomes an anode part (oxygen generation chamber A) and a cathode part (hydrogen generation chamber C).

  As the solid electrolyte membrane 63, it is preferable to use a solid electrolyte membrane in which a porous layer made of a noble metal, particularly platinum, is chemically formed by electroless plating. As the solid polymer electrolyte, a cation exchange membrane (a fluororesin sulfonic acid cation exchange membrane, for example, “Nafion 117” manufactured by DuPont is preferable.

  In the present embodiment, as described above, the hydrogen / oxygen gas generator is formed using the water electrolysis apparatus 1 configured by the electrolysis cell shown in FIG. 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 is supplied to the oxygen generation chamber A through the pure water supply path. Pure water is prevented from flowing into the hydrogen generation chamber C by an O-ring or the like.

  Oxygen gas generated in the oxygen generation chamber is discharged into the electrolytic tank 2 through the oxygen gas extraction passage 68a and the oxygen gas extraction passage 68, and is used from the electrolytic tank 2 through the oxygen gas supply piping section 31 and the like. Supplied to places, etc. In the water electrolysis apparatus 1, oxygen gas is prevented from flowing into the hydrogen generation chamber C by an O-ring or the like.

  Further, the hydrogen gas generated in the hydrogen generation chamber passes through the hydrogen gas extraction passage 67a, the hydrogen gas extraction path 67, and the hydrogen gas transfer piping section 14 in the water electrolysis apparatus 1 (electrolysis cell), and then the high-pressure hydrogen separation tank 4 To be transported. Hydrogen gas is prevented from flowing into the oxygen generation chamber A by an O-ring or the like.

  The hydrogen / oxygen gas generating apparatus according to the present embodiment is configured as shown in FIGS. 1 and 2 described above. In such an apparatus, pure water supply control, current value control, and the like are appropriately performed. Yes.

  The hydrogen / oxygen gas generating apparatus according to the present embodiment is configured as shown in FIGS. 1 and 2 described above. In such an apparatus, pure water supply control, current value control, and the like are appropriately performed. Yes.

  FIG. 3a) shows a flowchart when the hydrogen / oxygen gas generator according to this embodiment is operated. Hereinafter, the control method will be specifically described with reference to necessary drawings such as FIG.

  As shown in FIG. 3 a), in the hydrogen / oxygen gas generator according to the present embodiment, first, pure water is supplied to the electrolytic tank 2 in step 601. 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, based on the water level detection signal in step 602, it is determined whether or not the water level in the electrolytic tank 2 is a predetermined amount. If the water level has reached a predetermined amount (when it is determined “Yes” in step 603), then the process of step 604 is performed. Further, when the water level has not reached the predetermined amount (when it is determined “No” in step 603), the process after step 602 is performed again while the makeup water pump 6 is 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 electrolysis cell 1 is detected. That is, in this step 605, since the circulating water pump 8 is driven and pure water is supplied to the electrolysis cell 1 before energization to the electrolysis cell 1, the amount of circulating water is detected.

  Next, in step 606, based on the circulating water amount detection signal in step 605, it is determined whether or not a predetermined amount of water is supplied to the electrolysis cell 1. Then, when the circulating water amount has reached a predetermined amount (when it is determined “Yes” in step 606), the processing in step 607 is then performed. Further, when the circulating water amount has not reached the predetermined amount (when it is determined “No” in step 606), the processing after step 605 is performed again without proceeding to step 607 (that is, The driving of the circulating water pump 8 and the detection of the circulating water amount are continuously performed).

  Next, in step 607, energization of the water electrolysis apparatus 1 is started. That is, in the hydrogen / oxygen gas generating device according to the present embodiment, the current to the water electrolysis device 1 is not changed until a predetermined amount of pure water is circulated in the water electrolysis device (electrolysis cell) 1. Supply is started. As described above, the energization is started after the circulating water flow rate is confirmed. When energization is performed in a state where 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 63 may be damaged. That is, in this embodiment, in order to protect the solid electrolyte membrane 63, the water electrolysis apparatus 1 is energized after confirming the circulation amount of pure water. Here, the supply of current to the water electrolysis apparatus 1 is performed as long as a predetermined time (for example, about 30 seconds) is required until the current value is increased from 0% (0 A) to 100% (for example, 600 A). . By supplying the current in this way, a current is gradually applied to the solid electrolyte membrane 63, so that the solid electrolyte membrane 63 can be protected. That is, when the supply current to the water electrolysis apparatus 1 fluctuates suddenly, there is a possibility that an overshoot occurs and an excessive current is applied to the electrolysis cell, thereby damaging the solid electrolyte membrane. According to the stepwise current supply means), such a problem can be effectively solved.

  Next, in step 608, a continuous hydrogen / oxygen supply process is performed by the hydrogen / oxygen gas generator shown in FIG. 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, it is determined whether or not to end the hydrogen / oxygen supply process. If it is determined here that the hydrogen / oxygen supply step is to be ended (when “Yes” is determined in step 609), then the processing of step 610 is performed. When it is determined not to end the hydrogen / oxygen supply process (when it is determined “No” at step 609), the processing after step 608 is performed again.

Next, in step 610, energization of the water electrolysis apparatus 1 is ended based on the determination of the end of the hydrogen / oxygen supply process in step 609.
More specifically, at the time of this stop, a water injection process as shown in the flowchart of FIG. That is, the valve 55 is closed, both the recirculation valve 54A and the injection water control valve 52A are opened, and the pure water stored in the water injection tank 50 flows naturally to the hydrogen separation tank 4 through the pure water injection pipe 52. And a water injection process for storing the hydrogen gas in the hydrogen separation tank 4 in the water injection tank 50 is performed, and water injection is performed when the hydrogen separation tank water level meter 4L detects that the hydrogen separation tank 4 is filled with pure water. The process is ended, and the reflux valve 54A and the injection water control valve 52A are closed.

  In addition, by maintaining the inside of the water injection tank 50 at the same pressure as that of the hydrogen separation tank by a method described later before the hydrogen / oxygen gas generator is stopped, the hydrogen separation tank 4 is purified water filled with the pressure at the end of the operation. It can be held at.

  Although not particularly shown in the flowchart, in step 610, the energization is terminated in a state where the anode side of the water electrolysis apparatus 1 is sufficiently filled with pure water. Specifically, the circulating water pump 8 is stopped several seconds (about 30 seconds) after the energization of the water electrolysis apparatus 1 is stopped. By operating the circulation pump for a predetermined time after the energization is stopped in this way, it is possible to prevent oxygen gas from staying in the water electrolysis cell, and thus to prevent the solid electrolyte membrane 63 from being subjected to an excessive load. Can do.

  Furthermore, when restarting the hydrogen / oxygen supply process, the high-pressure hydrogen gas held in the water injection tank 50 can be used, and the water electrolyzer 1 and the hydrogen separation tank 4 can be adjusted to the pressure before the shutdown. Since it is maintained, there is no need to wait until the hydrogen gas reaches the supply pressure as in the prior art, and the supply of hydrogen gas can be resumed in a shorter time than in the prior art.

At this time, steps 607 and 608 are as shown in the flowchart of FIG. That is, while the valve 55 is closed, the injection water control valve 52A and the hydrogen gas discharge valve 53A are opened, and the hydrogen gas stored in the water injection tank 50 is supplied to the hydrogen gas supply pipe 21. Then, a reflux process is performed in which pure water filled in the hydrogen separation tank 4 is caused to flow backward from the pure water injection pipe 52 and accommodated by the pressure of the hydrogen gas introduced from the water electrolysis apparatus 1 into the hydrogen separation tank 4. When the hydrogen separation tank water level meter 4L detects that the pure water in the hydrogen separation tank 4 has been returned to the water injection tank 50, the injection water control valve 52A and the hydrogen gas discharge valve 53A are closed. Then, the valve 55 is opened to supply hydrogen gas only from the hydrogen separation tank 4 side.
From this, the water injection tank 50 stores pure water having a pressure when the operation of the hydrogen / oxygen gas generator is stopped.

  In the present embodiment, a water injection tank 50 disposed above the hydrogen separation tank 4 as a water injection mechanism and a pure water injection pipe 52 that connects the water injection tank 50 and the hydrogen separation tank 4 are provided. Water can be injected using natural flow and does not require extra power. Further, since the pure water injection pipe 52 communicates with the bottom of the hydrogen separation tank 4, no extra power is required for returning the filled pure water to the water injection tank 50. In addition, since the hydrogen gas stored in the hydrogen separation tank 4 when the hydrogen / oxygen gas generator is stopped is temporarily stored in the water injection tank 50, the hydrogen gas can be effectively used without being discarded. It is possible to suppress an increase in operating cost and equipment cost without requiring a new tank for storing hydrogen gas.

  In this embodiment, the gas dissolved in the pure water is reduced in pressure to become bubbles and mixed in the pure water, and the bubbles can prevent the pump and the polisher from malfunctioning. And in the point which can be operated at a higher pressure while maintaining safety, the pure water having the pressure at the time of operation stop is stored in the separation tank. In the present invention, the pure water is stored in the separation tank. The pressure is not limited to the same pressure as that of the separation tank at the time of shutdown.

  As described above, the operation of the hydrogen / oxygen gas generator according to the present embodiment is controlled based on the processes from step 601 to step 610 in FIG. 3a) and the reflux process and water injection process in FIGS. 3b) and c).

  Next, the pure water supply control for the electrolytic tank 2 and the current value control for the water electrolysis apparatus 1 in the hydrogen / oxygen supply process performed in step 608 will be specifically described.

  FIG. 4 shows a flowchart of one aspect of the pure water supply control according to this embodiment.

  As shown in FIG. 4, in the present embodiment, first, in step 701, the pure water storage amount in the electrolytic tank 2 is detected. Here, 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 702, based on the water level detection signal in step 701, it is determined whether or not the water level in the electrolytic tank 2 is below a predetermined value. When it is determined that the water level is equal to or lower than the predetermined value (when “Yes” is determined in step 702), the process of step 703 is performed. If the water level is not less than or equal to the predetermined value (if “No” is determined in step 702), the processing from step 701 onward is performed again.

  Next, in step 703, driving of the makeup water pump 6 is started based on the determination in step 702. That is, the makeup water pump 6 is driven to replenish pure water from the pure water tank 3 to the electrolytic tank 2 via the pure water supply piping section.

  Next, in step 704, the amount of pure water stored in the electrolytic tank 2 is detected. Here, similarly to step 701, the 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, based on the water level detection signal in step 704, it is determined whether or not the water level in the electrolytic tank 2 is within a predetermined range. If it is determined that the water level is within the predetermined range (when “Yes” is determined in step 705), then the processing 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), the replenishment water pump 6 is driven again and after step 704 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 processing after step 701 is performed again.

  The processes from Step 701 to Step 706 described above are basic pure water supply (replenishment) control in the hydrogen / oxygen gas generator according to this embodiment. Although not particularly shown in FIG. 4, in the present embodiment, pure water in the electrolytic tank 2 is circulated through a pure water circulation pipe portion 7 provided as a closed circuit with respect to the electrolytic tank 2. However, it is configured to be supplied to the water electrolysis apparatus 1.

  Specifically, in the present embodiment, pure water in the electrolytic tank 2 is circulated by the circulating water pump 8 provided in the pure water circulation piping unit 7, and the heat provided in the pure water circulation piping unit 7. Pure water is supplied to the pure water holes 115 and 116 of the water electrolysis apparatus 1 through the exchanger 9, the polisher 10, and the filter 11. The pure water circulation pipe section 7 is also provided with a water quality alarm means 12, a water temperature alarm means 13, and a circulating water amount alarm means.

  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, so that pure water having appropriate properties is supplied. Is possible. 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 the pure water is increased. Moreover, by providing the filter 11, impurities contained in the pure water can be removed and pure water can be supplied to the water electrolysis apparatus 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. The heat exchanger 9, the polisher 10, or the filter 11 can be replaced before inappropriate water (such as low purity or a large amount of impurities) is supplied. It is. Moreover, in this embodiment, since the circulating water amount warning means is provided, it prevents that the amount of circulating water falls below a processing amount (predetermined processing amount) and an electrolysis cell is damaged. That is, if the amount of water supplied to the electrolysis cell is insufficient, the flow of water in the electrolysis cell becomes non-uniform, and the solid electrolyte membrane may be damaged by local heat generation. By providing this, it is possible to detect in advance a decrease in the amount of circulating water and effectively solve such a problem. Therefore, according to this embodiment, pure water having appropriate properties can be continuously supplied to the water electrolysis apparatus 1. In the present embodiment, as described above, since degassing is provided at an appropriate location of the pure water circulation pipe section 7, the oxygen gas in the pure water circulation pipe section 7 is used for the circulation of pure water. In order not to cause a problem, it is possible to vent the gas as needed.

  As described above, in the present embodiment, the quality and temperature of pure water are controlled and pure water having appropriate properties is supplied to the water electrolysis apparatus 1, so that the life of the solid electrolyte membrane 63 can be extended. It becomes possible, and the electrolysis efficiency in the water electrolysis apparatus 1 can also be improved.

  In the present embodiment, the pure water separated from the hydrogen gas in the hydrogen separation tank 4 can also be reused via the pure water return pipe section 15 (and the pure water tank 3 etc.) (water electrolysis apparatus). 1 can be supplied). In the present embodiment, as described above, the pure water tank 3 and the electrolytic tank 2 are connected by the pure water supply piping unit 5, and the water electrolysis apparatus 1 and the hydrogen separation tank 4 in the electrolytic tank 2 are connected. The hydrogen separation tank 4 and the pure water tank 3 are connected by a pure water return pipe section 15. That is, 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 piping unit 5, the hydrogen gas transfer piping unit 14, and the pure water return piping unit 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 this closed circuit is repeated continuously, the dissolved rate is On the other hand, it is not preferable in terms of the device configuration. That is, 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 (makeup water tank) 3 as it is, the pressure is large. Since the pressure is released to the atmospheric pressure, the dissolved hydrogen corresponding to the differential pressure is gasified and released as the pressure is reduced. If it does so, hydrogen and air will mix in the pure water tank 3, and hydrogen concentration will rise gradually and various malfunctions may arise. Therefore, the hydrogen / oxygen gas generator according to the present embodiment is configured to eliminate the above-described problems by disposing a gas scrubber 16 at a predetermined location of the pure water return pipe section 15.

  Next, current value control for the water electrolysis apparatus 1 will be described. FIG. 5 shows a flowchart of one aspect of current value control according to the present embodiment.

  As shown in FIG. 5, in the present embodiment, first, in step 801, the pressure of hydrogen gas is detected using the first pressure detection means 25 provided in the hydrogen separation tank 4. Here, the pressure of the hydrogen gas in the hydrogen separation tank 4 is the amount of hydrogen gas produced (the amount of hydrogen gas produced in the water electrolysis apparatus 1 and conveyed to the hydrogen separation tank 4 via the hydrogen gas conveyance piping unit 14). The amount of hydrogen gas varies depending on the balance with the amount of hydrogen gas supplied (the amount of hydrogen gas supplied from the hydrogen separation tank 4 to the location where the hydrogen gas is used via the hydrogen gas supply pipe 21).

  Next, in step 802, based on the pressure detection signal in step 801, it is determined whether or not the hydrogen gas pressure in the hydrogen separation tank 4 is equal to or lower than a predetermined value. This is because, when the hydrogen gas pressure becomes a predetermined value or less, 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 (when “Yes” is determined in step 802), then the processing in step 803 is performed. If it is determined that the hydrogen gas pressure is not less than or equal to the predetermined value (when “No” is determined in step 802), the processing in and after step 801 is performed again.

  Next, in step 803, based on the determination 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, the current value control means. A current having an appropriate value is supplied from 28 to the water electrolysis apparatus 1. Here, the current to be supplied is appropriately selected according to the required amount of supplied hydrogen gas (or hydrogen gas pressure, etc.) and the hydrogen gas pressure fluctuation rate (hydrogen gas pressure fluctuation per unit time). And supplied to the water electrolysis apparatus 1.

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

  Next, in step 805, based on the pressure detection signal in step 804, it is determined whether or not the hydrogen gas pressure in the hydrogen separation tank 4 is within a predetermined range. When it is determined that the hydrogen gas pressure is within the predetermined range (when “Yes” is determined in step 805), the process of step 806 is then performed. When it is determined that the hydrogen gas pressure is not within the predetermined range (when it is determined “No” in step 805), the processing from step 803 onward is performed again.

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

  In the present embodiment, as described above, a current is supplied to the water electrolysis apparatus 1 as shown in steps 801 to 806. 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 means 25, and this detection signal is sent to the current value control means 28 to be used as the detection signal. A current value corresponding to the pressure fluctuation is supplied to the water electrolysis apparatus 1. In the present embodiment, a rectifier or the like is used as the current value control means 28. That is, in this embodiment, rectifier PID control is performed using a rectifier or the like.

Current supply to the water electrolysis device can be controlled more easily by using constant current control that constantly supplies a constant current, or by using ON / OFF control to prevent the control mechanism from becoming complicated. It is.
According to the PID control, a large tank for storing hydrogen gas (that is, a tank capable of handling from the lower limit value to the upper limit value of the working pressure) is required to accommodate the required pressure of hydrogen gas. Can be prevented. In order to cope with fluctuations in 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 changed from the upper limit side to the lower limit side. In the case of shifting to (1), it is possible to prevent the hydrogen gas from being released into the atmosphere or the like to cope with the required hydrogen gas pressure. That is, when the hydrogen gas pressure to be used moves to the upper limit value side, using the rectifier PID control as described above, it is quicker than other current supply methods (always constant or ON / OFF control). (Generation of hydrogen gas in response to an increase in the required hydrogen gas pressure). Therefore, there is also an effect that it is not necessary to always store a predetermined amount (for example, gas generation amount for 30 minutes to 2 hours in 100% operation) in the tank. Furthermore, the electrolysis apparatus of the present embodiment can maintain the pressure on the cathode side and the anode side uniformly even when the output of the apparatus is reduced (for example, 15% or less) as compared with alkaline water electrolysis. It is possible to prevent the possibility of oxygen mixing with the diaphragm. For this reason, when the apparatus is stopped / restarted, there is an effect that the operation of purging the gas in the apparatus by purging with N ₂ is not required.

  In addition, as described above, the hydrogen / oxygen gas generator according to the present embodiment is configured such that an appropriate current is supplied from the current value control means 28 to the water electrolysis cell 1 according to the amount of hydrogen gas used. Therefore, it is possible to eliminate waste with respect to the generated hydrogen gas and the current supplied to the water electrolysis cell 1. In the hydrogen / oxygen gas generator according to the present embodiment, pure water is supplied to the water electrolysis cell 1 through the pure water circulation pipe section 7 which is a closed circuit. The tank 2 can maintain a relatively high hermeticity. That is, a predetermined hydrogen gas pressure can be obtained without driving the water electrolysis cell 1. Therefore, when there is no particular change in the pressure of hydrogen gas (when hydrogen gas is not used), it is possible to stop supplying current to the water electrolysis cell 1. Therefore, in the hydrogen / oxygen gas generator according to this embodiment, the water electrolysis cell 1 can be driven in the range of 0 to 100% while supplying hydrogen or the like at an appropriate pressure.

  In the hydrogen / oxygen gas generator according to this embodiment, the pressure of the hydrogen gas in the hydrogen separation tank 4 is detected by the first pressure detection means 25, and the inside of the electrolytic tank 2 is detected by the second pressure detection means 35. The oxygen gas pressure is detected and each detection signal is sent to the differential pressure detection means 45. Based on the 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 The relief valve 36 is adjusted as appropriate. In the hydrogen / oxygen gas generating apparatus according to the present embodiment, hydrogen gas can be used to prevent the oxygen gas from being mixed into the hydrogen gas through the solid electrolyte membrane and to increase the purity of the obtained hydrogen gas even during operation. The pressure is set slightly higher than the oxygen gas pressure. That is, in the present embodiment, the valves 26 and 36 are adjusted so that the hydrogen gas pressure is slightly higher than the oxygen gas pressure in the water electrolysis cell 1 based on the above-described differential pressure signal. It has been broken.

  If necessary, the pressure of the oxygen gas can be slightly higher than that of the hydrogen gas. As described above, the slight pressure difference provided between the hydrogen gas and the oxygen gas is usually 0.05 to 1 MPa, preferably 0.05, from the viewpoint that the load applied to the solid electrolyte membrane can be suppressed. -0.4 MPa More preferably, it is 0.05-0.1 MPa.

  Furthermore, in this embodiment, each relief valve 26 and 36 mentioned above will function also as an interlock. That is, when any abnormality occurs in the differential pressure signal obtained by the differential pressure detecting means 45, the relief valves 26 and 36 are appropriately adjusted to protect the solid electrolyte membrane 63 and the like, At least one of gas and oxygen gas is discharged through the relief pipes 27 and 37. The interlock using the relief valves 26 and 36 is not limited to the above-described configuration. Therefore, for example, as each relief valve 26, 36, a spring relief valve or the like can be used. When the pressure in each relief pipe portion 27, 37 exceeds a predetermined pressure, each relief valve 26 and 36 may be configured to be properly opened.

  Further, in the hydrogen / oxygen gas generator according to the present embodiment, hydrogen gas is supplied to the oxygen gas supply pipe portion 31 provided for supplying oxygen gas from the electrolytic tank 2 to the oxygen use location (not shown). Detection means 34 is provided. The hydrogen gas detection means 34 is configured using an on-line gas analyzer such as a thermal conductivity type or a density type in order to detect the hydrogen concentration in the oxygen gas. According to the present embodiment, it is possible to detect the occurrence of pinholes in the solid electrolyte membrane 63 by detecting the hydrogen gas concentration in the oxygen gas in the oxygen gas supply pipe section 31. That is, according to this embodiment, as described above, the pressure in the water electrolysis apparatus 1 is higher on the hydrogen gas generation side (hydrogen generation chamber C side) than on the oxygen gas generation side (oxygen generation chamber A side). Therefore, if a pinhole or the like is generated in the solid electrolyte membrane 63, hydrogen gas is mixed from the hydrogen generation chamber C into the oxygen generation chamber A, and the oxygen gas mixed with hydrogen gas is The oxygen gas supply pipe 31 is supplied. Therefore, according to the present embodiment, as shown in FIG. 1, the hydrogen gas detection means 34 is provided in the oxygen gas supply pipe section 31 and the hydrogen gas concentration in the oxygen gas is monitored, so that the solid electrolyte membrane 63 is damaged. (Pinhole) etc. can be discovered at an early stage, and maintenance and management of the device can be effectively performed. The installation location of the hydrogen gas detection means is not limited to the oxygen gas supply piping section 31. For example, the electrolytic tank 2 is provided with a concentration measurement takeout pipe and is provided in the takeout pipe. Also good.

  Further, in the hydrogen / oxygen gas generating apparatus according to the present embodiment, hydrogen is supplied to the hydrogen gas supply pipe portion 21 provided for supplying hydrogen gas from the hydrogen separation tank 4 to a hydrogen use location (not shown). Gas flow rate control means 24 is provided. As described above, the hydrogen gas flow rate control unit 24 is configured using the flow rate detection unit 24A and the rated flow rate control valve 24B. The flow rate detecting means 24A constantly monitors the flow rate of the hydrogen gas flowing through 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 structured to do. That is, according to this 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 inside of the hydrogen gas supply pipe section 21 is Before the flowing hydrogen gas exceeds the rated flow rate, a control signal is sent from the flow rate detecting means 24A to the rated flow rate control valve 24B, and the rated flow rate control valve 24B is adjusted so that hydrogen gas exceeding the rated flow rate does not flow. The 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 section 21 fluctuates, hydrogen gas of a rated flow rate or higher flows in the hydrogen gas supply pipe section 21. Therefore, the quality of hydrogen gas can be kept constant. According to such a configuration having the hydrogen gas flow rate control means 24, it is possible to effectively prevent a problem when the user uses a buffer tank or the like. Specifically, in the case of using a buffer tank, the amount of hydrogen used may vary greatly between normal times and peak times. In such a case, if the hydrogen / oxygen gas generator is configured in accordance with the peak usage, the capacity is increased, the operating rate is reduced, and the economy is poor. For this reason, the pressure in the buffer tank is used with a width (for example, it is used in a width of 0.9 MPa to 0.4 MPa). During this time, a gas exceeding the rated generation amount of the water electrolysis apparatus 1 is used. In such a configuration, in order to perform the rated operation of the water electrolysis apparatus 1, as shown in the present embodiment, it is necessary to control the flow rate so that the gas exceeding the rating does not flow. As a result, the water electrolysis apparatus 1 continues to operate stably, and the gas properties (pressure and the like) at the downstream dehumidifier inlet can be controlled to be constant, and the supply gas quality can be maintained constant. Moreover, since it becomes possible to prevent the use beyond the performance of the water electrolysis apparatus (electrolysis cell) 1 if it is such a structure, the lifetime of an apparatus can also be achieved.

  Further, in the hydrogen / oxygen gas generator according to the present embodiment, a valve 18 is provided in the hydrogen gas transfer piping section 14 provided between the water electrolysis apparatus 1 and the hydrogen separation tank 4, and In order to bypass the valve 18 on the hydrogen gas transfer piping unit 14, a bypass piping unit 19 is provided. The bypass piping unit 19 is provided with a check valve 20. Here, the check valve 20 is configured not to be opened 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, when a pressure of a predetermined value or more (for example, 0.1 MPa or more) is applied, the check valve 20 is opened for the first time, and the hydrogen electrolysis device 1 supplies hydrogen through the bypass piping unit 19. Hydrogen gas is configured to flow through the separation tank 4. Therefore, according to the hydrogen / oxygen gas generator according to the present embodiment, when a pressure higher than a predetermined value is applied to the bypass pipe portion 19, the hydrogen gas is transferred via the check valve 20. It becomes. Therefore, since the check valve 20 is opened and hydrogen gas can be properly circulated through the hydrogen gas transfer piping unit 14, the bypass piping unit 19, and the check valve 20, the water electrolysis apparatus 1 is It is possible to effectively prevent the solid electrolyte membrane 63 constituting the breakage and the like. Further, when the valve 18 is normally closed and hydrogen gas is conveyed through the bypass pipe section 19, the valve 18 is closed, so that the hydrogen gas separation is performed even when the operation is stopped. It is possible to further prevent the hydrogen gas from flowing back from the tank to the water electrolysis cell and damaging the solid electrolyte membrane 63 constituting the water electrolysis cell 1.

  Further, the hydrogen / oxygen gas generating apparatus according to the present embodiment is configured to be able to control the gas pressure and the water level in each of the tanks 2 and 4 so as to become predetermined values using various detection means. Specifically, the electrolytic tank 2 is controlled so that the tank internal pressure becomes a predetermined value using the second pressure control means 35, the differential pressure detection means 45, the second relief valve 36, and the like. Using the electrolytic tank water level meter 2L and the makeup water pump 6, the water level in the tank is controlled to be a predetermined value. The hydrogen separation tank 4 is controlled so that the tank internal pressure becomes a predetermined value using the first pressure control means 25, the differential pressure detection means 45, the first relief valve 26, and the like. The tank water level meter 4L and the pure water discharge valve 4A are used to control the water level in the tank to a predetermined value. Furthermore, the pressures in the oxygen generation chamber A and the hydrogen generation chamber C in the water electrolysis apparatus 1 are also controlled to be appropriately set to predetermined values as described above. In the present embodiment, as described above, each gas pressure and the water level in each tank 2 and 4 can be controlled to be a predetermined value. That is, the hydrogen / oxygen gas generator according to the present embodiment is configured to be operable based on certain conditions. Therefore, the hydrogen / oxygen gas generator according to the present embodiment can basically be operated based on certain conditions, so that a high-quality gas (particularly a high-purity hydrogen gas) can be obtained. it can. In addition, since it can be operated under certain conditions, it is difficult for stress to occur in each element that constitutes the device, and the life of the entire device as well as each component can be extended. It becomes. 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. It becomes.

  In the present embodiment, the case where the hydrogen / oxygen gas generating apparatus is configured by using one water electrolysis apparatus 1 has been described. However, the present invention is not limited to this configuration. The electrolysis apparatus 1 may be used to configure a hydrogen / oxygen gas generator. At this time, each water electrolysis apparatus 1 may be provided with an electrolysis tank 2 or the like, and each water electrolysis apparatus 1 may be blocked to constitute a hydrogen / oxygen gas generation apparatus. According to such a configuration, since it is possible to detect a failure of the water electrolysis apparatus 1 or the like for each block as well as the entire apparatus, even if a failure or the like occurs in any part of the apparatus, Only the failed block can be stopped and exchanged. Therefore, with a hydrogen / oxygen gas generator that realizes such blocking, even if a failure occurs in the water electrolysis apparatus 1 or the like, it is not necessary to stop the entire apparatus. Can be realized.

  Further, in this embodiment, the water injection mechanism and the hydrogen gas discharge mechanism are configured as described above, but the present invention is not limited to this configuration, and pure water is injected as the water injection mechanism. As long as the mechanism can be maintained in a pressurized state in the hydrogen separation tank 4, it may be configured by combining various general pumps, pipes, tanks, etc. The hydrogen gas discharge mechanism is simply released into the atmosphere. There may be. That is, when the supply of hydrogen gas is stopped, the water injection mechanism for injecting pure water and the inside of the hydrogen separation tank 4 are filled so that the pure water can be filled and the internal pressure can be made pressurized by the pure water. If the hydrogen gas discharge mechanism which discharges the stored hydrogen gas is provided, the kind, form, etc. will not be limited.

  In the present embodiment, the separation of hydrogen gas that is easier to pass through the solid electrolyte membrane than oxygen gas is possible in that it can more reliably prevent the hydrogen gas and oxygen gas from being mixed through the solid electrolyte membrane. The gas discharge mechanism and the water injection mechanism are provided in the tank. However, in the present invention, the gas discharge mechanism and the water injection mechanism may be provided in the oxygen gas separation tank, and both the oxygen gas and hydrogen gas separation tanks may be provided. A gas discharge mechanism and a water injection mechanism may be provided.

In addition, the hydrogen / oxygen gas generating apparatus according to the present embodiment has not been particularly described with respect to the piping portion for connecting each element, but in the present invention, the piping portion for transporting a fluid having a large amount of oxygen gas. A hydrogen / oxygen gas generator is constructed using pipes having appropriate characteristics for the (O ₂ rich line) and the pipe part (H ₂ rich line) for conveying a fluid containing a large amount of hydrogen gas. May be. Specifically, for example, in an O ₂ rich line, after a surface of stainless steel is subjected to an electropolishing treatment and heated in an oxidizing atmosphere, a colored oxide film of a metal oxide mainly composed of an iron-based oxide is formed. It is preferable to use stainless steel formed on the surface (see Japanese Patent Laid-Open No. 10-140322). Such stainless steel has a characteristic that the elution amount of metal ions with respect to a fluid containing a large amount of oxygen gas is extremely small. Therefore, if an O ₂ rich line is configured using such stainless steel, a device capable of effectively preventing unnecessary metal ions from being eluted into oxygen gas can be realized. In addition, for example, the H ₂ rich line cleans the stainless steel surface, heats it in an oxidizing atmosphere to form a colored oxide film on the cleaned surface, and then dissolves the colored oxide film. It is preferable to use the removed stainless steel (see JP-A-10-25561). Such stainless steel has a characteristic that the elution amount of metal ions with respect to a fluid containing a large amount of hydrogen gas is extremely small. Therefore, if such a stainless steel is used to form an H ₂ rich line, it is possible to realize an apparatus that can effectively prevent unnecessary elution of metal ions into the hydrogen gas.

Furthermore, in the present embodiment, not only the piping section described above but also the tanks 2 and 4, the electrolytic tank 2 is configured using stainless steel similar to the O ₂ rich line, and the hydrogen separation tank is H It is preferable to use the same stainless steel as the ₂ rich line. According to this preferable configuration, it is possible to prevent the elution of metal ions in each of the tanks 2 and 4, and therefore, by using such a tank, it is possible to realize an apparatus capable of supplying a high purity gas. it can.

  Moreover, in this invention, it is preferable to comprise so that the pure water in the pure water tank 3 may be bubbled using the oxygen gas produced | generated with its own apparatus. In the hydrogen / oxygen gas generating apparatus according to the present embodiment, air (in particular nitrogen) is the only impurity, and such air is mixed into the apparatus mainly through the pure water tank 3. Therefore, if such air is eliminated, hydrogen or oxygen with higher purity can be obtained. Therefore, in the present invention, in order to exclude such impurity air, it is preferable that the pure water tank 3 is bubbled with oxygen gas. At this time, oxygen gas or the like that should be relieved can be used for bubbling. According to such a configuration, a hydrogen / oxygen gas generator capable of obtaining high-purity hydrogen gas or oxygen gas by using oxygen gas or the like that should originally be relieved without particularly using new equipment or the like. Can be realized.

  Further, in the present embodiment, the hydrogen / oxygen gas generating apparatus in which the water electrolysis apparatus 1 is accommodated in the electrolysis tank (tank that also functions as an oxygen separation tank) 2 has been described, but the present invention is limited to this configuration. It is good also as a structure not hold | maintained at a pressure vessel 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. 6 shows an example of a hydrogen / oxygen gas generator. In FIG. 6, the same elements as those described with reference to FIG. In the hydrogen / oxygen gas generator shown in FIG. 6, pure water is supplied to the electrolysis cell 1 provided outside the oxygen separation tank 2 via the pure water circulation piping section 7, and this electrolysis cell is supplied to the electrolysis cell. On the other hand, as in the hydrogen / oxygen gas generator described with reference to FIG. 1 and the like, electric power (current) is supplied through the current value control means 28. Further, the hydrogen gas generated in the electrolysis cell 1 is transferred to a hydrogen separation tank (not shown) via the hydrogen gas transfer piping unit 14. Further, the oxygen gas generated in the electrolysis cell is transported to the oxygen separation tank 2 via the oxygen gas transport piping unit 94. The hydrogen / oxygen gas generating apparatus shown in FIG. 6 is configured as described above, and the points where the electrolysis cell 1 is provided outside the tank (and the presence of the oxygen gas transport piping unit 94 associated therewith) are as follows. Except for this, the configuration is basically the same as that of the hydrogen / oxygen gas generator described with reference to FIG. That is, the hydrogen / oxygen gas generator shown in FIG. 6 can be provided with various sensors as in the case of the hydrogen / oxygen gas generator described with reference to FIG. Therefore, it is possible to achieve the same effect as the hydrogen / oxygen gas generator described with reference to FIG.

  Further, in the present embodiment, a polisher, a filter, and the like are arranged in the pure water circulation piping unit. However, a makeup water pump, a pure water tank, and the like are not provided in the pure water circulation piping unit. It is also possible to increase the pressure resistance of the hydrogen gas and oxygen gas to be increased by increasing the pressure resistance of the pure water circulation piping section by arranging in the pure water supply piping section.

  In addition, when a polisher, a filter, etc. are arranged in the pure water supply piping section as described above, the purity of water supplied to the electrolysis cell can be suppressed from being lowered by dissolved metal as described above. From the point of view, it is preferable to expose the water electrolysis cell on the water surface as described above. Further, a part of the water in the pure water circulation piping section is returned to the pure water tank, and the water is replenished by passing through a polisher and a filter. It is preferable to increase the amount of water produced.

  In this embodiment, the water electrolysis cell is housed in the oxygen separation tank. However, the water electrolysis cell may be housed in a hydrogen separation tank instead of the oxygen separation tank, and housed in another pressure vessel. It is also possible.

  When the water electrolysis cell is configured to be accommodated in the oxygen separation tank, the pressure difference between the inside and outside of the water electrolysis cell is made small so that hydrogen gas at a higher pressure is generated while suppressing damage to the water electrolysis cell. obtain. Furthermore, hydrogen embrittlement of the member is reduced as compared with the case where it is accommodated in the hydrogen separation tank. Moreover, even if a malfunction occurs in the water electrolysis cell, the decrease in purity of the hydrogen gas in the hydrogen separation tank can be reduced. In addition, in terms of reducing hydrogen embrittlement of the member and reducing the purity of hydrogen gas in the hydrogen separation tank even if a failure occurs in the water electrolysis cell, the water electrolysis cell is separately accommodated in a pressure vessel. The same effect can be obtained by pressurizing the inside of the pressure vessel with a gas such as nitrogen gas. However, when the water electrolysis cell is accommodated in the oxygen separation tank, the pressure vessel is separately used. It can suppress that the number of parts increases and manufacturing cost increases. Furthermore, it is possible to suppress an increase in operating cost due to pressure control of nitrogen gas or the like.

  Further, in the present embodiment, the entire water electrolysis cell is uniformly and quickly cooled, and the water electrolysis cell is submerged in water in the oxygen separation tank from the point that it can be prevented from becoming defective due to high temperatures locally. In the present invention, the water electrolysis cell may be exposed and stored on the water surface by providing a pedestal in the oxygen separation tank. Pure water, especially pure water called ultrapure water, has the potential to dissolve metals, etc. due to high pressure, so water electrolysis cells are exposed and stored on the water surface as described above. While suppressing the deterioration of the cell, higher pressure hydrogen gas can be generated.

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

Schematic system diagram of a hydrogen / oxygen gas generator according to an embodiment of the present invention Schematic which shows an example of the electrolysis cell which comprises the water electrolysis apparatus which comprises the hydrogen and oxygen gas generator which concerns on FIG. a) Flowchart when operating the hydrogen / oxygen gas generating apparatus according to the present embodiment b) Flowchart showing a recirculation process of the hydrogen / oxygen gas generating apparatus according to the present embodiment c) Hydrogen / oxygen gas generation according to the present embodiment Flow chart showing the water injection process of the device The flowchart which shows the one aspect | mode of the pure water supply control which concerns on this embodiment The flowchart which shows the one aspect | mode of the electric current value control which concerns on this embodiment. The figure which shows a part of schematic systematic diagram of the hydrogen and oxygen gas generator which concerns on other embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Water electrolysis apparatus (electrolysis cell), 2 ... Electrolytic tank, 2L ... Electrolytic 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 ... Makeup water pump, 7 ... Pure water circulation piping, 8 ... Circulating water pump, 9 ... Heat exchanger, 10 ... Polisher, 11 ... Filter, 12 ... Water quality alarm means, 13 ... Water temperature alarm means, 14 ... Hydrogen gas transfer piping section, 15 ... Pure water return piping section, 16 ... Gas scrubber, 17 ... Hydrogen discharge piping section, 18 ... Valve, 19 DESCRIPTION OF SYMBOLS ... Bypass piping part, 20 ... Check valve, 21 ... Hydrogen gas supply piping part, 22 ... Hydrogen gas supply valve, 23 ... Hydrogen gas dehumidification means, 24 ... Hydrogen gas flow rate control means, 24A ... Flow rate detection means, 24B ... Rating Flow control valve, 25 ... first Pressure detecting means, 26 ... first relief valve, 27 ... first relief piping section, 28 ... current value control means, 31 ... oxygen gas supply piping section, 32 ... oxygen gas supply valve, 33 ... oxygen gas dehumidifying means, 34 ... Hydrogen gas detection means, 35 ... Second pressure detection means, 36 ... Second relief valve, 37 ... Second relief piping, 45 ... Differential pressure detection means, 50 ... Water injection tank, 52 ... Pure water injection Piping, 52A ... Injection water control valve, 53 ... Hydrogen gas discharge piping, 53A ... Hydrogen gas discharge valve, 54 ... Recirculation piping, 54A ... Recirculation valve, 60 ... Bolt, 61 ... Insulating plate, 62 ... Electrode plate, 63 ... Solid Electrolyte membrane, 64 ... porous power supply, 65 ... gasket, 66 ... protective sheet, 67 ... hydrogen gas extraction path, 67a ... hydrogen gas extraction path, 68 ... oxygen gas extraction path, 68a ... oxygen gas extraction Passage, 69 ... end plates, 94 ... oxygen gas conveying pipe section A ... oxygen generating chamber, C ... hydrogen generating chamber

Claims (6)

It has an anode part with a positive electrode, a cathode part with a negative electrode, and a solid electrolyte membrane that separates the anode part and the cathode part, and water is electrolyzed to generate oxygen gas at the anode part. A water electrolysis cell in which hydrogen gas is generated at the cathode part,
Hydrogen separation in which hydrogen gas generated in the cathode portion is taken out in a pressurized state and is communicated with the cathode portion, and hydrogen gas and water in the cathode portion are introduced and gas-liquid separated in a pressurized state A tank,
Oxygen separation that is communicated with the anode part and oxygen gas and water in the anode part are introduced and gas-liquid separated in a pressurized state so that oxygen gas generated in the anode part can be taken out in a pressurized state A hydrogen / oxygen gas generator comprising a tank,
When at least one of the hydrogen separation tank and the oxygen separation tank is stopped, the gas stored therein is discharged and pure water is injected when the operation of the water electrolysis cell is stopped. A hydrogen / oxygen gas generator comprising a gas discharge mechanism and a water injection mechanism so that the water can be filled with pure water to be pressurized. The water injection mechanism is provided with a water injection tank arranged above the separation tank and communicated with the separation tank so that pure water is injected into the separation tank by natural flow and can fill the separation tank. The hydrogen / oxygen gas generator according to claim 1. At the start of operation of the water electrolysis cell, the water injection tank is connected to the bottom of the separation tank so that the pure water filled in the separation tank can be returned to the water injection tank by the pressure of the gas introduced from the water electrolysis device to the separation tank. The hydrogen / oxygen gas generator according to claim 2, which is communicated with each other. The hydrogen / oxygen gas generator according to claim 1, wherein the water electrolysis cell is accommodated in a pressure vessel. The hydrogen / oxygen gas generator according to claim 4, wherein the pressure vessel is the hydrogen separation tank or the oxygen separation tank. Using a water electrolysis cell having an anode part provided with a positive electrode, a cathode part provided with a negative electrode, and a solid electrolyte membrane separating the anode part and the cathode part, water was electrolyzed and the anode part To generate oxygen gas, to generate hydrogen gas at the cathode,
Introducing the hydrogen gas and water in the cathode part into a hydrogen separation tank and gas-liquid separation in a pressurized state so that hydrogen gas generated in the cathode part can be taken out in a pressurized state,
Hydrogen / oxygen gas generation in which oxygen gas and water in the anode part are introduced into an oxygen separation tank and gas-liquid separation is performed in a pressurized state so that the oxygen gas generated in the anode part can be taken out in a pressurized state A method of operating the device,
When the operation of the water electrolysis cell is stopped, in the separation tank of at least one of the hydrogen separation tank and the oxygen separation tank, the gas stored therein is discharged and pure water is injected, A method for operating a hydrogen / oxygen gas generator, wherein the interior is filled with pure water to provide a pressurized state.

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