JP2018193573A - Electrolytic liquid tank, electrolytic device, and hydrogen production system - Google Patents

Abstract

To provide an electrolytic liquid tank, an electrolytic device and a hydrogen production device, capable of improving the production efficiency of hydrogen gas while curtailing power consumption.SOLUTION: The electrolytic tank according to an embodiment of the present invention comprises a first container allowing an electrolytic liquid to flow therethrough, a second container of a larger surface area relative to the first container, allowing the electrolytic liquid to flow therethrough, and a switching part that can supply at least either of the first container and the second container with the electrolytic liquid according to the temperature of the electrolytic liquid.SELECTED DRAWING: Figure 5

Description

  Embodiments described herein relate generally to an electrolytic solution tank, an electrolytic device, and a hydrogen production system.

  In recent years, production of hydrogen gas using renewable energy has been attempted. Renewable energy refers to energy that is permanently replenished by the natural world, such as wind and sunlight. Power generation facilities such as wind power generators and solar battery panels using renewable energy can be installed in mountainous areas, deserts, and the like, for example. Therefore, hydrogen gas can be produced by installing a hydrogen production system in the vicinity of such a power generation facility and electrolyzing water using the electric power supplied from the power generation facility in the hydrogen production system. The produced hydrogen gas is transported to an energy consuming area (for example, a city), and the hydrogen gas is supplied to a fuel cell or a fuel cell vehicle. If such an energy system is established, renewable energy can be collected effectively. Moreover, once the electric power is converted into hydrogen gas, energy can be stored, or the power generation site and the energy consumption site need not be matched.

Here, in the hydrogen production system, there is a problem in that the production efficiency of hydrogen gas is lowered even if the temperature of the electrolytic solution becomes too high or too low. Therefore, the hydrogen production system is provided with a heating device (heater) and a cooling device (chiller) in order to control the temperature of the electrolytic solution.
However, electric power is required to operate the heating device and the cooling device.
Therefore, it has been desired to develop a technology capable of improving the production efficiency of hydrogen gas while suppressing power consumption.

JP 2015-117407 A

  The problem to be solved by the present invention is to provide an electrolytic solution tank, an electrolyzer, and a hydrogen production system capable of improving the production efficiency of hydrogen gas while suppressing power consumption.

  The electrolyte tank according to the embodiment includes a first container through which the electrolyte solution can pass, and a second container through which the electrolyte solution can pass through a first container that has a larger surface area than the first container. And a switching unit capable of supplying the electrolytic solution to at least one of the first container and the second container based on the temperature of the electrolytic solution.

It is a model perspective view for illustrating the hydrogen production system concerning this embodiment. It is a block diagram for illustrating a hydrogen production system. It is a block diagram for illustrating the electrolysis device concerning this embodiment. It is a schematic diagram for illustrating the container which concerns on a comparative example. It is a mimetic diagram for illustrating the electrolyte tank concerning this embodiment. It is a mimetic diagram for illustrating the 2nd container concerning other embodiments. It is a schematic diagram for illustrating the electrolyte solution tank concerning other embodiments. (A), (b) is a schematic diagram for illustrating the electrolyte solution tank which concerns on other embodiment. (A), (b) is a schematic diagram for illustrating the electrolyte solution tank which concerns on other embodiment.

  Hereinafter, embodiments will be illustrated with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.

First, the hydrogen production system 1 according to the present embodiment is illustrated.
The hydrogen production system 1 according to the present embodiment is a system that produces hydrogen gas (H ₂ ) by electrolyzing water by an electrolysis method. Moreover, in this Embodiment, the case where the hydrogen production system 1 operates using a renewable energy, and the case where it connects with the existing electric power grid | system and operates are included. Here, as an example, at least one of a plurality of components (for example, the rectifier 11, the electrolyzer 12, the controller 14 and the like) provided in the hydrogen production system 1 is generated by the power generation facility 100 using renewable energy. The power that can be supplied is shown.

FIG. 1 is a schematic perspective view for illustrating a hydrogen production system 1 according to the present embodiment. In FIG. 1, only relatively large components are shown, and small components and piping are not shown.
FIG. 2 is a block diagram for illustrating the hydrogen production system 1.
FIG. 3 is a block diagram for illustrating the electrolyzer 12 according to the present embodiment.
In FIG. 3, the current and signal flows are represented by two-dot chain lines, the gas flow is represented by a one-dot chain line, and the liquid flow is represented by a solid line.

As shown in FIGS. 1 and 2, the hydrogen production system 1 is provided with a rectifier 11, an electrolyzer 12, a hydrogen tank 13, and a controller 14.
As shown in FIG. 2, the hydrogen production system 1 can be installed near the power generation facility 100. The power generation facility 100 is a facility that generates power using renewable energy. The power generation facility 100 is, for example, a wind power generation facility or a solar power generation facility. The power generation facility 100 can be installed, for example, in a mountainous area, a desert, a remote island, or the like. Therefore, the hydrogen production system 1 may be installed in a land far away from an energy consumption place such as a city that is not connected to an existing power system. The power generation facility 100 supplies AC power P1 to the hydrogen production system 1.

  The rectifier 11 is electrically connected to the power generation facility 100. The rectifier 11 converts the AC power P1 supplied from the power generation facility 100 into DC power P2 and AC power P3. The rectifier 11 can include, for example, a rectifier and a transformer. The rectifier converts a part of the supplied AC power P1 into DC power P2 and outputs it. Moreover, a storage battery can be provided in the rectifier 11 to store the converted DC power P2. The transformer converts a part of the supplied AC power P1 into AC power P3 having a predetermined voltage and outputs it. The voltage of the AC power P3 is, for example, 200V.

The electrolyzer 12 is electrically connected to the rectifier 11. Moreover, the electrolyzer 12 is connected to the hydrogen tank 13 through piping. Furthermore, the electrolyzer 12 is connected to a water source provided outside via a pipe. The water source is, for example, a water supply, a groundwater source, a tank that stores water brought in from the outside, and the like. Hereinafter, tap water, groundwater, and water brought in from outside are collectively referred to as “general water”.
The electrolyzer 12 produces hydrogen gas by electrolyzing water contained in the electrolyte S using the DC power P2 supplied from the rectifier 11. At this time, the oxygen gas (O ₂ ) produced together with the hydrogen gas can be exhausted to the outside, for example. The AC power P3 supplied from the rectifier 11 is used to drive a pump 36 and the like provided in the electrolysis device 12.

  The electrolyzer 12 includes an electrolyzer 32, a cathode gas gas-liquid separation chamber 33, an anode gas gas-liquid separation chamber 34, an electrolyte tank 35, a pump 36, an air pump 37, a pure water production device 38, a cleaning tower 41, a pump 42, A cleaning liquid tank 43, a buffer tank 44, a compressor 45, a chiller 46, a dryer 47, and a switch circuit 48 are provided.

The electrolytic bath 32 electrolyzes the electrolytic solution S. The electrolytic bath 32 has a liquid-tight structure that can store the electrolytic solution S. The electrolyte S can be, for example, an alkaline aqueous solution or an acidic aqueous solution. Examples of the alkaline aqueous solution include a potassium hydroxide (KOH) aqueous solution and a sodium hydroxide (NaOH) aqueous solution. The acidic aqueous solution is, for example, a sulfuric acid (H ₂ SO ₄ ) aqueous solution or a nitric acid (HNO ₃ ) aqueous solution. In this case, the electrolytic solution S has a low electrical resistance, a small amount of by-products generated during electrolysis, and a small amount of damage to the cathode electrode and the anode electrode using a general material. preferable. Therefore, the electrolytic solution S is preferably an alkaline aqueous solution rather than an acidic aqueous solution. In this case, if the electrolytic solution S is a potassium hydroxide aqueous solution, the cost of the electrolytic solution S can be reduced. The density | concentration of the potassium hydroxide in potassium hydroxide aqueous solution can be about 25 mass%, for example.

The inside of the electrolytic cell 32 can be partitioned into a plurality of cells 70. Each cell 70 is partitioned into a cathode side space and an anode side space by a diaphragm (not shown). The diaphragm is a membrane that allows water to pass but does not allow much gas to pass. The diaphragm can be, for example, a film in which a polymer nonwoven fabric is bonded to both surfaces of a polymer film made of PET (PolyEthylene Terephthalate). A cathode electrode (not shown) is provided in the cathode side space. An anode electrode (not shown) is provided in the anode side space. Each cell 70 is sealed, and one end of a hydrogen tube 51 is connected to the ceiling portion of the cathode side space. One end of an oxygen pipe 52 is connected to the ceiling portion of the anode side space.
When DC power P2 is supplied from the rectifier 11 to the cathode electrode and the anode electrode, the water contained in the electrolyte S is electrolyzed inside the electrolytic bath 32, and hydrogen gas and oxygen gas are generated. In addition, since a known technique can be applied to the electrolysis of the electrolytic solution S, a detailed description is omitted.

  The cathode gas gas-liquid separation chamber 33 is connected to the other end of the hydrogen pipe 51. The cathode gas gas-liquid separation chamber 33 flows from each cell 70 of the electrolytic cell 32 through the hydrogen pipe 51 in a state where the hydrogen gas and the electrolyte S are mixed. The hydrogen gas and the electrolyte solution S are separated in the cathode gas gas-liquid separation chamber 33. That is, the electrolyte S collects in the lower part of the cathode gas gas-liquid separation chamber 33, and the hydrogen gas collects in the upper part of the cathode gas gas-liquid separation chamber 33.

The anode gas gas-liquid separation chamber 34 is connected to the other end of the oxygen pipe 52. The anode gas gas-liquid separation chamber 34 flows from each cell 70 of the electrolytic cell 32 through the oxygen pipe 52 in a state where the oxygen gas and the electrolyte S are mixed. The oxygen gas and the electrolyte S are separated in the anode gas gas-liquid separation chamber 34. That is, the electrolyte S collects in the lower part of the anode gas gas-liquid separation chamber 34, and the oxygen gas collects in the upper part of the anode gas gas-liquid separation chamber 34.
One end of an oxygen pipe 69 is connected to the upper part (for example, the ceiling part) of the anode gas gas-liquid separation chamber 34. The other end of the oxygen tube 69 is opened outside the electrolyzer 12 and serves as an exhaust port.

  The electrolytic solution tank 35 includes a first container 35a and a second container 35b having a larger surface area than the first container 35a. The electrolytic solution S can pass through the first container 35a and the second container 35b. Details regarding the first container 35a and the second container 35b will be described later.

One end of the electrolyte tube 53 is connected to the lower part (for example, the bottom surface) of each of the cathode gas gas-liquid separation chamber 33 and the anode gas gas-liquid separation chamber 34. The other end of the electrolyte pipe 53 is connected to each of the first container 35a and the second container 35b via the switching unit 53a.
One end of the electrolyte tube 55 is connected to the lower part (for example, the bottom surface) of each of the first container 35a and the second container 35b via the switching unit 55a. The other end of the electrolytic solution pipe 55 is connected to the electrolytic cell 32 via the pump 36.

  The pump 36 circulates the electrolytic solution S between the electrolytic solution tank 35 and the electrolytic bath 32. For example, the pump 36 supplies the electrolytic solution S in the first container 35 a or the second container 35 b to the electrolytic cell 32. The electrolytic solution S supplied to the electrolytic bath 32 is supplied from the electrolytic solution S to the cathode gas gas-liquid separation chamber 33 and the anode gas gas-liquid separation chamber 34. The electrolyte S supplied to the cathode gas gas-liquid separation chamber 33 and the anode gas gas-liquid separation chamber 34 is supplied from the cathode gas gas-liquid separation chamber 33 and the anode gas gas-liquid separation chamber 34 to the first container 35a or the second container 35a. It is supplied to the container 35b.

  That is, by operating the pump 36 and the switching units 53a and 55a (first container 35a → electrolyzer 32 → cathode gas gas / liquid separation chamber 33 and anode gas gas / liquid separation chamber 34 → first container 35a), Alternatively, the electrolytic solution S circulates through a path of (second container 35b → electrolyzer 32 → cathode gas gas / liquid separation chamber 33 and anode gas gas / liquid separation chamber 34 → second container 35b).

The suction port of the air pump 37 is open to the atmosphere. The exhaust port of the air pump 37 is connected to the first container 35 a and the second container 35 b through the air pipe 56.
In this case, one end of the air pipe 57 is connected to each upper part (for example, ceiling part) of the 1st container 35a and the 2nd container 35b. The other end of the air pipe 57 is disposed outside.
When the air pump 37 operates, the air in the first container 35a and the second container 35b is discharged and replaced with new air.

  The pure water production apparatus 38 is connected to each of the first container 35 a and the second container 35 b through a pure water pipe 58. As described above, in the electrolytic cell 32, water contained in the electrolytic solution S is electrolyzed to generate hydrogen gas and oxygen gas. In this case, when the water contained in the electrolytic solution S is consumed, the concentration of the electrolytic solution S increases. Therefore, the pure water production apparatus 38 regenerates the electrolytic solution S having a predetermined concentration by adding the same amount of consumed water to the electrolytic solution S having a high concentration. The regenerated electrolytic solution S is supplied to the electrolytic cell 32 again.

  That is, the pure water production apparatus 38 generates pure water from general water supplied from the outside, and supplies it to each of the first container 35a and the second container 35b. The electric conductivity of the generated pure water is, for example, 10 μS / cm (micro Siemens per centimeter) or less. Note that a switching valve (not shown) may be provided in order to supply pure water to one of the first container 35a and the second container 35b.

  The same number of cleaning towers 41 and pumps 42 as the number of cells 70 in the electrolytic cell 32 are provided. In order to avoid complication, only one washing tower 41 and one pump 42 are depicted in FIG. The upper part (for example, the ceiling part) of the cathode gas gas-liquid separation chamber 33 and the cleaning tower 41 are connected by a hydrogen pipe 61.

  The cleaning tower 41 is separated by the cathode gas gas-liquid separation chamber 33, and the cleaning liquid C is sprayed on the hydrogen gas supplied by the hydrogen pipe 61 by a shower, so that components contained in the electrolytic solution S (for example, alkali Component and acid component). The cleaning liquid C is pure water, for example.

  One end of the cleaning liquid pipe 62 is connected to the lower part (for example, the floor surface) of the cleaning tower 41. The other end of the cleaning liquid pipe 62 is connected to an upper portion (for example, a ceiling portion) of the cleaning tower 41. A pump 42 is provided in the middle of the cleaning liquid pipe 62. The cleaning tower 41, the cleaning liquid pipe 62, and the pump 42 constitute a circulation path.

  The pump 42 pumps up the cleaning liquid C from the lower part of the cleaning tower 41 and injects the cleaning liquid C onto the gas phase part at the upper part of the cleaning tower 41. That is, the pump 42 circulates the cleaning liquid C stored in the cleaning tower 41.

  The cleaning liquid tank 43 stores the cleaning liquid C. The cleaning liquid tank 43 is connected to the cleaning tower 41 via a cleaning liquid pipe 63. The cleaning liquid tank 43 supplies the cleaning liquid C to the cleaning tower 41 as necessary.

  The buffer tank 44 is a container that temporarily stores the produced hydrogen gas. The buffer tank 44 is provided with an inlet 44i and an outlet 44o. The area of the cross section orthogonal to the direction from the inlet 44 i to the outlet 44 o in the buffer tank 44 is larger than the total area of the cross sections orthogonal to the flow direction of the hydrogen pipe 64.

  The inlet 44 i of the buffer tank 44 is connected to all of the plurality of cleaning towers 41. The upper part (for example, the ceiling part) of the cleaning tower 41 and the inlet 44 i of the buffer tank 44 are connected by a hydrogen pipe 64. A switching valve 65 is interposed in the hydrogen pipe 64. Opening and closing of the switching valve 65 is controlled by the control device 14.

  The compressor 45 compresses the hydrogen gas discharged from the cleaning tower 41 and supplied via the buffer tank 44. For example, the compressor 45 is provided with a motor and an inverter circuit, and the processing capability can be changed by a signal from the control device 14. An intake port of the compressor 45 is connected to an outlet 44 o of the buffer tank 44 through a hydrogen pipe 66.

The chiller 46 cools the compressor 45.
The dryer 47 is connected to the compressor 45 through a hydrogen pipe 67. One end of the hydrogen pipe 67 is connected to the exhaust port of the compressor 45, and the other end of the hydrogen pipe 67 is connected to the intake port of the dryer 47. The dryer 47 purifies the hydrogen gas compressed by the compressor 45 and supplied via the hydrogen pipe 67. In the dryer 47, a filter that removes impurities (for example, moisture) in hydrogen gas by chemical adsorption is provided. An exhaust port of the dryer 47 is drawn out of the electrolysis apparatus 12 through a hydrogen pipe 68 and connected to the hydrogen tank 13.

  The switch circuit 48 supplies the DC power P <b> 2 supplied from the rectifier 11 to each cell 70 of the electrolytic cell 32. The switch circuit 48 includes the same number of switches as the cells 70 and a stack control unit that controls opening and closing of the switches. The stack control unit operates according to a signal from the control device 14.

  The plurality of cells 70 of the electrolytic cell 32 can be connected in series to the rectifier of the rectifier 11. For example, among the plurality of cells 70 arranged in a row, the anode electrode of the cell 70 arranged at one end is connected to the positive electrode of the rectifier, and the anode electrode of the other cell 70 is connected to the cathode of the adjacent cell 70. Can be connected to an electrode. In this case, a node between adjacent cells 70 is connected to one end of a switch provided in the switch circuit 48. In addition, among the plurality of cells 70 arranged in a line, the cathode electrode of the cell 70 arranged at the other end is connected to one end of a switch provided in the switch circuit 48. The other ends of all the switches provided in the switch circuit 48 are connected to the negative electrode of the rectifier.

  The hydrogen tank 13 stores hydrogen gas produced by the electrolysis device 12. The hydrogen tank 13 is connected to a dryer 47 of the electrolysis apparatus 12 via a hydrogen pipe 68.

  The control device 14 controls the operations of the rectifying device 11 and the electrolysis device 12. For example, the control device 14 controls the switching units 53a, 55a, and 352d provided in the electrolyte solution tanks 35, 351, and 352 based on the temperature of the electrolyte solution S. The control device 14 can be, for example, a computer including a CPU (Central Processing Unit) and a memory. The operations of the rectifier 11 and the electrolyzer 12 are controlled based on an operation program stored in the memory. The control device 14 may also control the power generation facility 100.

Next, the first container 35a and the second container 35b will be further described.
FIG. 4 is a schematic diagram for illustrating a container 135 according to a comparative example.
In FIG. 4, the cathode gas gas-liquid separation chamber 33 and the anode gas gas-liquid separation chamber 34 will be omitted in order to avoid complexity.
As shown in FIG. 4, one end of the electrolytic solution tube 153 is connected to the electrolytic bath 32, and the other end of the electrolytic solution tube 153 is connected to the container 135. Further, one end of the electrolytic solution pipe 155 is connected to the container 135, and the other end of the electrolytic solution pipe 155 is connected to the electrolytic cell 32 via the pump 36. The pump 36 supplies the electrolytic solution S in the container 135 to the electrolytic cell 32. The electrolytic solution S supplied to the electrolytic bath 32 is supplied to the container 135 through the electrolytic solution pipe 153. That is, when the pump 36 operates, the electrolytic solution S circulates in the path of the container 135 → the electrolytic cell 32 → the container 135.

  Here, when the electrolytic solution S is electrolyzed, heat is generated. If the temperature of the electrolyte solution S becomes too high due to the generated heat, the production efficiency of hydrogen gas may be reduced. In this case, even if the temperature of the electrolytic solution S is too high or too low than the predetermined temperature range, the production efficiency of hydrogen gas is reduced. For example, if the temperature of the electrolytic solution S is about 80 ° C., the production efficiency of hydrogen gas can be improved.

In this case, the temperature of the electrolytic solution S tends to be lower than the predetermined temperature range immediately after the electrolysis apparatus is started. During the operation of the electrolyzer, the temperature of the electrolytic solution S tends to be higher than a predetermined temperature range due to heat generated during electrolysis. Further, the temperature of the electrolytic solution S varies depending on the temperature of the surrounding atmosphere. For example, the temperature of the electrolytic solution S tends to increase during the summer, and the temperature of the electrolytic solution S tends to decrease during the winter.
Therefore, generally, a heating device (heater) 154a for heating the electrolytic solution S and a cooling device (chiller) 154b for cooling the electrolytic solution S are provided.

However, electric power is required to operate the heating device 154a and the cooling device 154b. Therefore, a part of the electric power supplied from the power generation facility 100 through the rectifier 11 is used to operate the heating device 154a and the cooling device 154b. In this case, even when the power supply by the power generation facility 100 is stable or the amount of power supplied is not limited, if the heating device 154a and the cooling device 154b are operated, the power consumption in the hydrogen production system 1 is increased accordingly. growing. When the hydrogen production system is increased in size, or further configured with a plurality of hydrogen production systems, the power consumption increases accordingly. In addition, when the power supply is unstable (for example, when the amount of power increases or decreases) or when the amount of power supplied is limited, the amount of power that can be used for the production of hydrogen gas is small. Thus, there arises a new problem that the production efficiency of hydrogen gas is lowered.
According to the present embodiment, as will be described in detail below, power consumption in the hydrogen production system 1 can be suppressed. In addition, when the power supply is unstable or the amount of power supplied is limited as described above, the power consumption can be suppressed, so the power required for the production of hydrogen gas is reduced. It is also possible to secure without making it.
Therefore, according to the present embodiment, in the hydrogen production system 1, it is possible to improve the production efficiency of hydrogen gas by keeping the electrolytic solution in a predetermined temperature range while suppressing power consumption. In addition, even when the hydrogen production system is increased in size or further constituted by a plurality of hydrogen production systems, the power consumption can be suppressed and the production efficiency of hydrogen gas can be improved.

FIG. 5 is a schematic view for illustrating the electrolytic solution tank 35 according to the present embodiment.
In FIG. 5, the cathode gas gas-liquid separation chamber 33 and the anode gas gas-liquid separation chamber 34 are omitted in order to avoid complication.
As shown in FIG. 5, the electrolyte tank 35 includes a first container 35a, a second container 35b, a switching unit 53a, and a switching unit 55a.
The first container 35a has a box shape and has a space in which the electrolytic solution S is stored.

  The second container 35b has a larger surface area than the first container 35a. The second container 35b includes a supply unit 35b1, a discharge unit 35b2, and a plurality of cylinders 35b3. The supply part 35b1 has a plate shape and has a space in which the electrolyte S is stored. The discharge part 35b2 has a plate shape and has a space in which the electrolyte S is stored. The discharge part 35b2 faces the supply part 35b1. The plurality of cylinders 35b3 allow the electrolyte S to pass therethrough. The plurality of cylinders 35b3 are provided between the supply unit 35b1 and the discharge unit 35b2. One end of the plurality of cylinders 35b3 is connected to the supply unit 35b1, and the space inside the plurality of cylinders 35b3 and the space inside the supply unit 35b1 are connected. The other ends of the plurality of cylinders 35b3 are connected to the discharge part 35b2, and a space inside the plurality of cylinders 35b3 and a space inside the discharge part 35b2 are connected. Therefore, the electrolyte S supplied to the inside of the supply part 35b1 can be supplied to the inside of the discharge part 35b2 through the space inside the plurality of cylinders 35b3. Providing a plurality of cylinders 35b3 makes it easy to increase the surface area.

The material of supply part 35b1, discharge part 35b2, and several cylinder 35b3 should just have the tolerance with respect to the electrolyte solution S. FIG. The material of the supply unit 35b1, the discharge unit 35b2, and the plurality of cylinders 35b3 can be, for example, a metal such as a nickel alloy or an aluminum alloy, a resin, or the like. Note that electrolytic corrosion may occur when a metal is used for the portion in contact with the electrolytic solution S. Therefore, when using a metal, it is preferable to resin-coat the inner wall of supply part 35b1, discharge part 35b2, and several cylinder 35b3.
In FIG. 5, the plurality of cylinders 35b3 arranged in a matrix in the plan view is illustrated, but the arrangement of the plurality of cylinders 35b3 is not limited to this. For example, the plurality of cylinders 35b3 can be arranged concentrically in a plan view.
Moreover, although the cylindrical cylindrical body 35b3 is illustrated, a rectangular cylindrical cylindrical body 35b3 or the like may be used. Further, a plate-like heat radiation fin can be provided on the outer surface of the cylindrical body 35b3. A plurality of heat radiation fins can be provided.

  One end of the electrolyte pipe 53 is connected to each of the first container 35a and the second container 35b (supply part 35b1) via the switching part 53a. The other end of the electrolytic solution pipe 53 is connected to the electrolytic bath 32. One end of the electrolyte pipe 55 is connected to each of the first container 35a and the second container 35b (discharge part 35b2) via the switching part 55a. The other end of the electrolyte pipe 55 is connected to the electrolytic cell 32 via the pump 36. Therefore, also in the present embodiment, the electrolytic solution S circulates when the pump 36 operates.

  Further, similarly to the comparative example described above, the temperature of the electrolytic solution S also changes in the present embodiment. Therefore, in the present embodiment, the circulation path of the electrolytic solution S is switched according to the temperature of the electrolytic solution S. Based on the temperature of the electrolytic solution S, at least one of the switching unit 53a and the switching unit 55a is configured to supply the electrolytic solution S to the first container 35a and supply the electrolytic solution S to the second container 35b. Switch. For example, when the temperature of the electrolytic solution S is higher than a predetermined temperature range, the electrolytic solution S is circulated through the second container 35b. Since the second container 35b has a larger surface area than the first container 35a, the heat dissipation of the electrolyte S can be promoted. Therefore, the electrolyte solution S can be cooled so that the temperature of the electrolyte solution S falls within a predetermined temperature range. Further, even when a cooling device 54b such as a chiller for cooling the electrolytic solution S is provided as an auxiliary, the power required to operate the cooling device 54b can be greatly reduced.

When the temperature of the electrolytic solution S is lower than the predetermined temperature range, the electrolytic solution S is circulated through the first container 35a. Since the first container 35a has a smaller surface area than the second container 35b, the heat dissipation of the electrolytic solution S can be suppressed. Therefore, the electric power required for operating the heating device 54a such as a heater for heating the electrolytic solution S can be greatly reduced.
As a result, among the power supplied from the power generation facility 100 via the rectifier 11, power that can be used for electrolysis can be increased, so that the production efficiency of hydrogen gas can be improved.

  The temperature detector 54c such as a thermocouple for detecting the temperature of the electrolytic solution S can be provided in the electrolytic solution tube 55 between the pump 36 and the switching unit 55a, for example. The heating device 54a for heating the electrolytic solution S can be provided in the electrolytic solution pipe 55 between the pump 36 and the switching unit 55a, for example. When the cooling device 54b for cooling the electrolytic solution S is provided as an auxiliary, the cooling device 54b can be provided, for example, in the electrolytic solution pipe 55 between the pump 36 and the switching unit 55a.

FIG. 6 is a schematic view for illustrating a second container 35ba according to another embodiment.
The second container 35b illustrated in FIG. 5 has a plurality of cylindrical bodies 35b3 connected in parallel.
The second container 35ba illustrated in FIG. 6 has a plurality of cylindrical bodies 35b3 connected in series. Since the surface area can be increased even if the plurality of cylindrical bodies 35b3 are connected in series, the same effect as that of the second container 35b described above can be obtained.

  Further, the plurality of cylinders 35b3 can be brought into close contact with a heat radiating plate 35ba1 formed of a metal such as aluminum. In this way, heat dissipation can be further improved. Moreover, although the case where the some cylinder 35b3 is arrange | positioned planarly was illustrated, as illustrated in FIG. 5, the some cylinder 35b3 can also be arrange | positioned in three dimensions.

FIG. 7 is a schematic view for illustrating an electrolytic solution tank 351 according to another embodiment.
As a method for changing the area (heat radiation area) of the tank in contact with the electrolytic solution S, the electrolytic solution tank 351 changes the length of the passage path of the electrolytic solution S in the tank, and the contact area between the tank and the electrolytic solution S Adjust the temperature by increasing or decreasing.
As shown in FIG. 7, the electrolytic solution tank 351 has a supply unit 35b1, a discharge unit 35b2, and a plurality of third containers.
The third container can be, for example, the cylindrical body 35b3 described above. Hereinafter, a case where the third container is the cylindrical body 35b3 will be described as an example.

At least one of the plurality of cylindrical bodies 35b3 includes a switching unit 35b4 (corresponding to an example of a first switching unit) provided on the supply side of the electrolytic solution S of the cylindrical body 35b3, and an electrolytic solution S of the cylindrical body 35b3. At least one of the switching portions 35b4 (corresponding to an example of a second switching portion) provided on the discharge side of the. The switching unit 35b4 can be, for example, an on-off valve such as a butterfly valve. The switching unit 35b4 provided on the supply side of the electrolytic solution S controls the supply of the electrolytic solution S to the inside of the cylindrical body 35b3 and the stop of the supply. The switching part 35b4 provided on the discharge side of the electrolyte S controls the discharge of the electrolyte S from the inside of the cylindrical body 35b3 and the stop of the discharge.
Note that at least one of the switching unit 35b4 provided on the supply side of the electrolytic solution S and the switching unit 35b4 provided on the discharge side of the electrolytic solution S may be provided. Further, some of the plurality of cylinders 35b3 may not include the switching unit 35b4.

  If it does in this way, the 1st container 35a and the 2nd container 35b can be provided in one. For example, the first container 35a can be obtained by controlling the switching unit 35b4 to supply and discharge the electrolyte S in a part of the plurality of cylinders 35b3. Moreover, it can be set as the 2nd container 35b by controlling switching part 35b4 and supplying and discharging | emitting electrolyte solution S in all the cylinders 35b3.

  Further, the switching unit 35b4 provided on the supply side of the electrolytic solution S serves as the switching unit 53a described above. The switching unit 35b4 provided on the discharge side of the electrolytic solution S serves as the switching unit 55a described above.

  Moreover, based on the temperature of the electrolyte S, the number and position of the cylinder 35b3 to be used can be changed. For example, the number of cylinders 35b3 to be used can be increased as the temperature of the electrolytic solution S is increased, and the number of cylinders 35b3 to be used can be decreased as the temperature of the electrolytic solution S is decreased. Moreover, the cylindrical body 35b3 located on the outer side where heat dissipation is easier as the temperature of the electrolytic solution S becomes higher can be used, and the cylindrical body 35b3 located on the inner side where heat release is difficult as the temperature of the electrolytic solution S becomes lower. .

FIGS. 8A and 8B are schematic views for illustrating an electrolytic solution tank 352 according to another embodiment.
The electrolytic solution tank 352 is a method for changing the area (heat radiation area) of the tank in contact with the electrolytic solution S, by changing the length of the passage path of the electrolytic solution S in the tank, and the contact area between the tank and the electrolytic solution S Adjust the temperature by increasing or decreasing.
As shown in FIGS. 8A and 8B, the electrolytic solution tank 352 includes a container 352a (corresponding to an example of a fourth container), a partition part 352b, a lid part 352c, and a switching part 352d.

The electrolytic solution S can pass through the container 352a. The container 352a has a cylindrical shape, one end is open, and the other end is closed. A discharge port 352a1 through which the electrolytic solution S is discharged is provided on the bottom side of the container 352a.
The partition part 352b has a plate shape and is provided inside the container 352a. One end of the partition portion 352b is provided on the bottom surface of the container 352a, and the side surface of the partition portion 352b is provided on the inner surface of the container 352a. The partition part 352b partitions the inside of the container 352a into a plurality of regions. A plurality of partition portions 352b can be provided. When providing the some partition part 352b, the height of the some partition part 352b can each be made different. In this case, the height of the plurality of partition portions 352b can be made lower as the height is closer to the discharge port 352a1.

The lid portion 352c has a plate shape and is rotatably provided in the opening of the container 352a. The lid 352c is provided with a hole 352c1 penetrating in the thickness direction. The end of the electrolyte pipe 53 is connected to the hole 352c1, and the electrolyte S can be supplied to a region partitioned by the partition part 352b inside the container 352a.
The material of the container 352a, the partition part 352b, and the cover part 352c should just have the tolerance with respect to the electrolyte solution S. The material of the container 352a, the partition part 352b, and the lid part 352c can be the same as the material of the supply part 35b1, the discharge part 35b2, and the plurality of cylinders 35b3 described above.

  The switching unit 352d moves the position of the lid 352c in the rotation direction, and consequently the position of the hole 352c1 in the rotation direction. The region where the electrolyte S is supplied can be changed by moving the position of the hole 352c1 in the rotation direction by the switching unit 352d. That is, the switching unit 352d can supply the electrolytic solution S to at least one of the plurality of regions based on the temperature of the electrolytic solution S.

  If it does in this way, the 1st container 35a and the 2nd container 35b can be provided in one. For example, by controlling the switching unit 352d to supply the electrolyte S to a region close to the discharge port 352a1 among the plurality of regions partitioned by the partitioning unit 352b, the region becomes the first container 35a. In addition, if the electrolyte solution S is supplied to a region far from the discharge port 352a1 and the electrolyte solution S overflowing from the region is supplied to a region close to the adjacent discharge port 352a1, the region and the adjacent region become the second container 35b. It becomes.

Further, based on the temperature of the electrolytic solution S, the number of regions to be used can be changed. For example, the number of regions to be used can be increased as the temperature of the electrolytic solution S is increased, and the number of regions to be used can be decreased as the temperature of the electrolytic solution S is decreased.
For example, when the temperature of the electrolytic solution S is low, as shown in FIG. 8A, the electrolytic solution S can be supplied to a region closest to the discharge port 352a1. When the temperature of the electrolytic solution S is high, as shown in FIG. 8B, the electrolytic solution S can be supplied to a region farthest from the discharge port 352a1.

  In addition, although the cover part 352c provided rotatably and the switching part 352d which moves the position of the cover part 352c in the rotation direction are illustrated, the present invention is not limited to this. For example, the lid 352c can be fixed to the opening of the container 352a. Moreover, the hole 352c1 can be provided in the position which opposes each of the several area | region divided by the partition part 352b of the cover part 352c. Each of the plurality of holes 352c1 can be connected by branching the end portion of the electrolyte pipe 53. And the hole 352c1 which supplies electrolyte solution S can be selected with a switching valve etc., and the area | region which supplies electrolyte solution S can be changed.

FIGS. 9A and 9B are schematic views for illustrating an electrolytic solution tank 353 according to another embodiment.
As shown in FIGS. 9A and 9B, the electrolyte tank 353 includes a container 352a, a partition part 353b, a lid part 352c, and a switching part 352d.
The partition part 353b has a cylindrical shape and is provided inside the container 352a. One end of the partition portion 353b is provided on the bottom surface of the container 352a. The partition part 353b partitions the inside of the container 352a into a plurality of regions. A plurality of partition portions 353b can be provided. When providing the some partition part 353b, the height of the some partition part 353b can each be made different. Moreover, the some partition part 353b can be provided concentrically. In this case, the height of the partition portion 353b can be lowered as the inner surface of the container 352a is approached.
The material of the partition part 353b should just have the tolerance with respect to the electrolyte solution S. The material of the partition part 353b can be the same as the material of the supply part 35b1, the discharge part 35b2, and the plurality of cylinders 35b3 described above.

  If it does in this way, the 1st container 35a and the 2nd container 35b can be provided in one. For example, by controlling the switching unit 352d and supplying the electrolytic solution S to a region close to the inner surface of the container 352a among a plurality of regions partitioned by the partition unit 353b, the region becomes the first container 35a. . Further, if the electrolyte solution S is supplied to a region far from the inner side surface of the container 352a, and the electrolyte solution S overflowing from the region is supplied to a region near the inner side surface of the adjacent container 352a, the region and the adjacent region become the first region. 2 container 35b.

Further, based on the temperature of the electrolytic solution S, the number of regions to be used can be changed. For example, the number of regions to be used can be increased as the temperature of the electrolytic solution S is increased, and the number of regions to be used can be decreased as the temperature of the electrolytic solution S is decreased.
For example, when the temperature of the electrolytic solution S is low, as shown in FIG. 9A, the electrolytic solution S can be supplied to the region closest to the inner surface of the container 352a. When the temperature of the electrolytic solution S is high, as shown in FIG. 9B, the electrolytic solution S can be supplied to a region farthest from the inner surface of the container 352a.

  In addition, although the cover part 352c provided rotatably and the switching part 352d which moves the position of the cover part 352c in the rotation direction are illustrated, the present invention is not limited to this. For example, the lid 352c can be fixed to the opening of the container 352a. Moreover, the hole 352c1 can be provided in the position which opposes each of the several area | region divided by the partition part 353b of the cover part 352c. Each of the plurality of holes 352c1 can be connected by branching the end portion of the electrolyte pipe 53. And the hole 352c1 which supplies electrolyte solution S can be selected with a switching valve etc., and the area | region which supplies electrolyte solution S can be changed.

Next, the operation of the hydrogen production system 1 will be illustrated.
First, the power generation facility 100 generates power using renewable energy. The AC power P1 generated by the power generation is supplied to the rectifier 11 of the hydrogen production system 1. The supplied AC power P1 is unstable and includes short-cycle fluctuations and long-cycle fluctuations. For example, a short cycle variation is a variation with a cycle of less than one minute, and a long cycle variation is a variation with a cycle of one minute or more. When the power generation facility 100 is a wind power generation facility, the short-period fluctuation is a fluctuation due to the changing wind direction and wind speed, and the long-period fluctuation is a fluctuation due to weather change, seasonal change, and the like. In addition, when the power generation facility 100 is a solar power generation facility, the short-cycle fluctuation is a fluctuation due to the amount of sunlight that changes depending on the cloud condition, and the long-period fluctuation is a change between daytime and nighttime, Changes due to changes, seasonal changes, etc.

  When the electrolyzer 12 is activated, the electrolyte S is stored in the electrolyte tank 35 and the electrolytic tank 32. The electrolyte S is, for example, a potassium hydroxide aqueous solution having a concentration of 25% by mass. The pure water production apparatus 38 is supplied with general water, for example, ground water, from the outside of the hydrogen production system 1. Further, the cleaning liquid C is stored in the cleaning tower 41 and the cleaning liquid tank 43.

  Next, the control device 14 operates the rectifying device 11. The AC power P1 supplied to the rectifier 11 is distributed to the rectifier and the transformer provided in the rectifier 11. The AC power supplied to the rectifier absorbs short-cycle fluctuations through the storage battery. For this reason, the rectifier generates DC power P2 in which short-cycle fluctuations are suppressed. On the other hand, the voltage of the AC power supplied to the transformer is adjusted by the transformer and converted into AC power P3 having a predetermined standard voltage. In this way, the rectifier 11 supplies DC power P2 and AC power P3 to the electrolysis device 12.

Next, the control device 14 operates the components of the electrolysis device 12, such as the pump 36, the switching units 53a and 55a, the pump 42, the compressor 45, the chiller 46, the electrolytic cell 32, and the pure water production device 38.
By operating the pump 36 and the switching units 53a, 55a (first container 35a → electrolyzer 32 → cathode gas gas-liquid separation chamber 33 and anode gas gas-liquid separation chamber 34 → first container 35a), or The electrolytic solution S circulates through a path (second container 35b → electrolyzer 32 → cathode gas gas / liquid separation chamber 33 and anode gas gas / liquid separation chamber 34 → second container 35b).

  Here, when the electrolyzer 12 is started, the temperature of the electrolytic solution S is lower than a predetermined temperature range. Therefore, the electrolyte solution S is circulated through the first container 35a by switching the flow path using the switching units 53a and 55a. Further, the electrolytic solution S is heated by the heating device 54a so that the temperature of the electrolytic solution S is within a predetermined temperature range. In this case, since the first container 35a has a smaller surface area than the second container 35b, the heat dissipation of the electrolyte S can be suppressed. Therefore, the electric power required for operating the heating device 54a can be greatly reduced.

On the other hand, during the operation of the electrolysis apparatus 12, the temperature of the electrolytic solution S may be higher than a predetermined temperature range due to heat generated during electrolysis. In this case, the electrolyte solution S is circulated through the second container 35b by switching the flow path using the switching units 53a and 55a. Since the second container 35b has a larger surface area than the first container 35a, the heat dissipation of the electrolyte S can be promoted. Therefore, the electrolyte solution S can be cooled so that the temperature of the electrolyte solution S falls within a predetermined temperature range. Further, even when the cooling device 54b that cools the electrolytic solution S is used supplementarily, the power required to operate the cooling device 54b can be greatly reduced.
As a result, among the power supplied from the power generation facility 100 via the rectifier 11, power that can be used for electrolysis can be increased, so that the production efficiency of hydrogen gas can be improved.

  Further, when the pump 42 is operated, the cleaning liquid C circulates between the cleaning tower 41 and the pump 42, and the cleaning liquid C is injected into the gas phase in the upper part of the cleaning tower 41. When the compressor 45 operates, the hydrogen gas flowing into the intake port of the compressor 45 is compressed and discharged from the exhaust port. The compressor 45 is cooled by operating the chiller 46.

  Further, by supplying the DC power P2 to the electrolytic cell 32, a current flows between the cathode electrode and the anode electrode of the electrolytic cell 32, and the water in the electrolytic solution S is electrolyzed. When water is electrolyzed, hydrogen gas is generated on the cathode electrode side and oxygen gas is generated on the anode electrode side. Further, water in the electrolytic solution S in the electrolytic cell 32 is consumed, hydrogen gas is accumulated in the upper part of the cathode side space in the cell 70, and oxygen gas is accumulated in the upper part of the anode side space in the cell 70.

  And hydrogen gas and electrolyte solution S are extruded from the upper part of the cathode side space in each cell 70 of the electrolytic cell 32. The hydrogen gas and the electrolytic solution S flow into the cathode gas gas-liquid separation chamber 33 through the hydrogen pipe 51 and are separated into the hydrogen gas and the electrolytic solution S. Moreover, oxygen gas and electrolyte solution S are extruded from the upper part of the anode side space in each cell 70 of the electrolytic cell 32. The oxygen gas and the electrolytic solution S flow into the anode gas gas-liquid separation chamber 34 through the oxygen pipe 52 and are separated into the oxygen gas and the electrolytic solution S.

The electrolyte S in the cathode gas gas-liquid separation chamber 33 and the anode gas gas-liquid separation chamber 34 flows into the first container 35a or the second container 35b via the electrolyte pipe 53. When the water in the electrolytic solution S decreases with the electrolysis and the concentration of the electrolytic solution S increases (the amount of the electrolytic solution S decreases), the pure water production device 38 produces pure water from general water. Then, pure water is replenished to the electrolytic solution S through the pure water pipe 58. That is, the concentration of the electrolytic solution S is always maintained within a certain range. The concentration of the electrolytic solution S can be measured by, for example, a pH sensor. The amount of the electrolytic solution S can be measured with, for example, a water level meter. A pH sensor, a water level gauge, etc. can be provided in the 2nd container 35b etc., for example.

  The oxygen gas separated by the anode gas gas-liquid separation chamber 34 is exhausted to the outside of the hydrogen production system 1 through the oxygen pipe 69. The hydrogen gas separated by the cathode gas gas-liquid separation chamber 33 is introduced into the cleaning tower 41 through the hydrogen pipe 61. The hydrogen gas introduced into the cleaning tower 41 is removed by taking a shower of the cleaning liquid C, and the components contained in the remaining electrolyte S are dissolved in the cleaning liquid C.

The hydrogen gas processed by the cleaning tower 41 is accumulated in the buffer tank 44 through the hydrogen pipe 64 and the switching valve 65. Then, it is sent from the buffer tank 44 to the compressor 45 through the hydrogen pipe 66, compressed to 0.8 MPa (megapascal), for example, by the compressor 45, and sent to the dryer 47 through the hydrogen pipe 67. In the dryer 47, impurities such as water are removed by passing hydrogen gas through the filter. The hydrogen gas from which impurities have been removed is sent to the hydrogen tank 13 through the hydrogen pipe 68 and stored in the hydrogen tank 13.
The hydrogen gas stored in the hydrogen tank 13 is filled in, for example, a hydrogen lorry vehicle and transported to a consumption place.

In a general hydrogen production system, when an attempt is made to increase the amount of hydrogen produced by increasing the current density in an electrolytic cell or the like, resistance heat generation in the electrolytic cell or the like increases. For this reason, it is necessary to increase the number of cooling facilities for the electrolyte, increase the size of the cooling facilities, or increase the power consumption of the entire hydrogen production system.
Moreover, the case where the reduction | decrease of the electric power supplied to a hydrogen production system or the stop of electric power arises is assumed. For example, in the case of the power generation facility 100 using renewable energy, it is assumed that the power supplied to the hydrogen production system is reduced or stopped due to a change in weather or the like. Depending on the amount of power reduction and the length of power outage, the temperature of the electrolyte will decrease, so it may be necessary to add heating equipment to increase the temperature of the electrolyte, or to increase the size of the heating equipment. To do. In such a case, power consumption in the entire hydrogen production system increases.
The hydrogen production system 1 according to the embodiment of the present invention can efficiently adjust the temperature of the electrolytic solution (heat dissipation and heat retention) so as to be within a predetermined temperature range by switching the path through which the electrolytic solution passes. it can. Therefore, in the hydrogen production system 1, it becomes possible to reduce the cooling equipment and the heating equipment for the electrolytic solution, or to eliminate the need for these equipment itself. Manufacturing efficiency can be improved.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalents thereof. Further, the above-described embodiments can be implemented in combination with each other.

  DESCRIPTION OF SYMBOLS 1 Hydrogen production system, 11 Rectifier, 12 Electrolyzer, 13 Hydrogen tank, 14 Control apparatus, 32 Electrolyzer, 33 Cathode gas gas-liquid separation chamber, 34 Anode gas gas-liquid separation chamber, 35 Electrolyte tank, 35a 1st Container, 35b second container, 35b1 supply unit, 35b2 discharge unit, 35b3 cylinder, 35b4 switching unit, 36 pump, 38 pure water production device, 53 electrolytic solution pipe, 53a switching unit, 54a heating device, 54c temperature detector , 55 Electrolyte tube, 55a switching unit, 70 cells, 100 power generation facility, 351 electrolyte solution tank, 352 electrolyte solution tank, 352a container, 352b partition unit, 352c lid unit, 352d switching unit, 353 electrolyte solution tank, 353b partition unit , S electrolyte

Claims (9)

A first container through which an electrolyte can pass;
A second container having a larger surface area than the first container and capable of passing the electrolyte solution;
A switching unit capable of supplying the electrolytic solution to at least one of the first container and the second container based on the temperature of the electrolytic solution;
Electrolyte tank with   The electrolytic solution tank according to claim 1, wherein the second container has a plurality of cylindrical bodies through which the electrolytic solution can pass. A plurality of third containers through which the electrolyte can pass;
At least one of the plurality of third containers includes a first switching unit provided on the electrolyte solution supply side of the third container and a discharge side of the electrolyte solution of the third container. An electrolyte tank having at least one of the provided second switching units. A fourth container through which the electrolyte can pass;
A partition that divides the interior of the fourth container into a plurality of regions;
A switching unit capable of supplying the electrolytic solution to at least one of the plurality of regions based on the temperature of the electrolytic solution;
Electrolyte tank with The fourth container has an outlet;
A plurality of the partition portions are provided,
The electrolyte tank according to claim 4, wherein a height of the plurality of partition portions is lower as the height is closer to the discharge port. The electrolyte solution tank according to any one of claims 1 to 5,
An electrolytic cell capable of electrolyzing the electrolytic solution;
A pump capable of circulating the electrolytic solution between the electrolytic solution tank and the electrolytic cell;
Electrolyzer equipped with.   The electrolysis apparatus according to claim 6, wherein electric power generated by a power generation facility using renewable energy can be supplied to at least one of the electrolytic solution tank and the electrolytic cell. The electrolyte solution tank according to any one of claims 1 to 5,
An electrolytic cell capable of electrolyzing the electrolytic solution;
A pump capable of circulating the electrolytic solution between the electrolytic solution tank and the electrolytic cell;
Based on the temperature of the electrolytic solution, a control device capable of controlling a switching unit provided in the electrolytic solution tank,
Hydrogen production system equipped with   9. The hydrogen according to claim 8, wherein electric power generated by a power generation facility using renewable energy can be supplied to at least one of the electrolytic solution tank, the electrolytic cell, the switching unit, and the control device. Manufacturing system.

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