CN116710398A

CN116710398A - Hydrogen system and method for operating hydrogen system

Info

Publication number: CN116710398A
Application number: CN202180080372.8A
Authority: CN
Inventors: 尾沼重德; 中植贵之
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2020-12-03
Filing date: 2021-06-16
Publication date: 2023-09-05

Abstract

A hydrogen system is provided with a compressor, a pressure regulator and a controller, wherein a voltage is applied between an anode and a cathode which are arranged to sandwich an electrolyte membrane, hydrogen in a hydrogen-containing gas supplied to the anode is moved to the cathode, compressed hydrogen is generated by the compressor, the pressure regulator regulates at least the pressure of the anode, and when the hydrogen system is stopped, the controller controls the pressure regulator so that the pressure of the anode is higher than the pressure of the cathode in a state where the hydrogen-containing gas is sealed from flowing out of the anode.

Description

Hydrogen system and method for operating hydrogen system

Technical Field

The present disclosure relates to hydrogen systems and methods of operating hydrogen systems.

Background

In recent years, hydrogen has been attracting attention as a clean alternative energy source to replace fossil fuel due to environmental problems such as global warming, energy problems such as exhaustion of petroleum resources, and the like. Hydrogen generates substantially only water even when burned, does not emit carbon dioxide which causes global warming, and hardly emits nitrogen oxides or the like, and is therefore expected as a clean energy source. In addition, as a device for efficiently using hydrogen as a fuel, there is a fuel cell, for example, and development and popularization of the device for an automobile power supply and home self-power generation are underway.

In the coming hydrogen society, in addition to the production of hydrogen, there is a demand for development of a technology capable of storing hydrogen at high density and transporting or utilizing hydrogen at a small capacity and at low cost. In particular, in order to promote the popularization of fuel cells as a distributed energy source, it is necessary to provide a hydrogen supply infrastructure. Accordingly, various studies have been made on the production, purification, and high-density storage of high-purity hydrogen in order to stably supply hydrogen.

For example, patent document 1 describes that hydrogen can be purified and boosted by electrolysis of water by applying a voltage between an anode and a cathode. Specifically, hydrogen is extracted from water at the anode by passing an electric current through a polymer electrolyte membrane sandwiched between the anode and the cathode, and becomes protons. Then, protons move from the anode to the cathode along with the water molecules in the electrolyte membrane, thereby being reduced to hydrogen at the cathode. The laminated structure of the anode, electrolyte membrane, and cathode is referred to as a membrane electrode assembly (MEA: membrane ElectrodeAssembly).

Patent document 1 proposes that an electrode structure functioning as a fuel cell or an ion pump supplies air to an anode to scavenge residual gas (hydrogen) and water when the electrode structure is stopped in a hydrogen purification mode (when the electrode structure is operated as an ion pump).

Further, for example, patent document 2 proposes that when the hydrogen generating operation of the electrochemical device is completed, the on-off valve of the anode outlet is closed while the on-off valve of the anode inlet is kept open, and thereby, by controlling the power supply, a current is caused to flow through the electrochemical device in a direction opposite to that at the time of the hydrogen generating operation, and the hydrogen-containing gas retained in the anode is replaced with purified hydrogen gas similar to that of the cathode.

Prior art literature

Patent document 1: japanese patent laid-open publication No. 2011-100610

Patent document 2: japanese patent laid-open No. 2020-172405

Disclosure of Invention

Problems to be solved by the invention

As an example, the present disclosure has an object to provide a hydrogen system and a method of operating the hydrogen system that can suppress a decrease in efficiency of a hydrogen compression operation at the time of restarting, as compared with the conventional art.

Means for solving the problems

A hydrogen system according to an aspect of the present disclosure includes a compressor, a pressure regulator, and a controller, wherein a voltage is applied between an anode and a cathode provided so as to sandwich an electrolyte membrane, hydrogen in a hydrogen-containing gas supplied to the anode is moved to the cathode, compressed hydrogen is generated by the compressor, the pressure regulator regulates at least the pressure of the anode, and when the hydrogen system is stopped, the controller controls the pressure regulator so that the pressure of the anode is higher than the pressure of the cathode in a state in which the hydrogen-containing gas is sealed from flowing out of the anode.

A method for operating a hydrogen system according to an aspect of the present disclosure includes: a step of generating compressed hydrogen by applying a voltage between an anode and a cathode provided so as to sandwich an electrolyte membrane, and moving hydrogen in a hydrogen-containing gas supplied to the anode to the cathode; and stopping the hydrogen system, wherein the pressure of the anode is higher than the pressure of the cathode in a state of sealing off the hydrogen-containing gas flowing out from the anode.

ADVANTAGEOUS EFFECTS OF INVENTION

The hydrogen system and the method of operating the hydrogen system according to one aspect of the present disclosure can exhibit an effect of suppressing a decrease in efficiency of the hydrogen compression operation at the time of restarting, as compared with the conventional art.

Drawings

Fig. 1 is a diagram showing an example of the hydrogen system according to embodiment 1.

Fig. 2 is a diagram showing an example of the hydrogen system according to embodiment 3 of embodiment 1.

Fig. 3 is a diagram showing an example of the hydrogen system according to embodiment 2.

Fig. 4 is a diagram showing an example of the hydrogen system according to embodiment 3 of embodiment 2.

Fig. 5 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 3 of embodiment 2.

Fig. 6 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 4 of embodiment 2.

Fig. 7 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 5 of embodiment 2.

Fig. 8 is a flowchart showing an example of the operation of the hydrogen system according to the modification of embodiment 2.

Fig. 9 is a diagram showing an example of the hydrogen system according to embodiment 3.

Fig. 10 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 3.

Fig. 11 is a diagram showing an example of the hydrogen system according to embodiment 4.

Fig. 12 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 4.

Fig. 13 is a diagram showing an example of the hydrogen system according to embodiment 5.

Fig. 14 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 5.

Fig. 15 is a flowchart showing an example of the operation of the hydrogen system according to the modification of embodiment 5.

Fig. 16 is a diagram showing an example of the hydrogen system according to embodiment 6.

Fig. 17 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 6.

Fig. 18 is a diagram showing an example of the hydrogen system according to embodiment 7.

Fig. 19 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 7.

Detailed Description

In electrochemical compressors, typically the electrolyte membrane exhibits the desired proton conductivity in the wet state. Therefore, in order to maintain the efficiency of the hydrogen compression operation of the compressor at a desired value, it is necessary to maintain the electrolyte membrane in a wet state. Therefore, conventionally, a hydrogen-containing gas having high humidity is supplied to the anode of the multi-directional compressor.

Here, as in patent document 1, if air is supplied to the anode at the time of stopping and hydrogen and water remaining in the anode are discharged, there is a reduced possibility that flooding (a phenomenon of clogging due to water in the gas flow path) occurs at the anode. However, the above patent document 1 is insufficient in the study of suppressing overflow. This is for the following reason.

First, in the hydrogen compression operation of the compressor, a voltage is applied between the anode and the cathode of the MEA (cell). In this case, by flowing an electric current between the anode and the cathode, protons move from the anode to the cathode (electroosmosis) together with water molecules in the electrolyte membrane. On the other hand, the electro-osmotic water moving from anode to cathode moves from cathode to anode by the pressure difference between cathode and anode (back diffusion). In this case, the higher the gas pressure on the cathode side, the larger the amount of water that moves from the cathode to the anode. In the hydrogen compression operation of the compressor, even if water is back-diffused from the cathode to the anode, the hydrogen-containing gas flows through the anode, so that water does not remain, and flooding is suppressed.

Here, when the compressor is stopped, if the purging of the anode with air of patent document 1 is performed, water retained at the anode is discharged to the outside immediately before the purging, but after the purging of the anode, the back diffusion of water continues until the pressure difference between the anode and the cathode disappears, and the back diffused water is retained at the anode. This increases the possibility of flooding at the anode after the compressor is stopped. If flooding occurs, the diffusivity of the hydrogen-containing gas on the anode of the compressor is hindered at the time of restart, and thus the voltage of the voltage applicator required to ensure a predetermined amount of proton movement to the cathode may increase. Thus, the efficiency of the hydrogen compression operation decreases when the compressor is restarted.

Accordingly, the hydrogen system according to claim 1 of the present disclosure includes a compressor, a pressure regulator, and a controller, wherein a voltage is applied between an anode and a cathode provided so as to sandwich an electrolyte membrane, hydrogen in a hydrogen-containing gas supplied to the anode is moved to the cathode, compressed hydrogen is generated by the compressor, the pressure regulator regulates at least the pressure of the anode, and when the hydrogen system is stopped, the controller controls the pressure regulator so that the pressure of the anode is higher than the pressure of the cathode in a state in which the hydrogen-containing gas is sealed from the anode.

According to this configuration, the hydrogen system of the present embodiment can suppress a decrease in efficiency of the hydrogen compression operation at the time of restarting, as compared with the conventional hydrogen system.

Specifically, in the hydrogen system according to the present embodiment, the pressure regulator is controlled so that the pressure of the anode is higher than the pressure of the cathode in a state where the hydrogen-containing gas is sealed from the anode when the hydrogen system is stopped. This can suppress back diffusion of water from the cathode to the anode when the hydrogen system is stopped. In addition, in the case where condensed water is generated at the anode, the condensed water can be diffused from the anode to the cathode by the pressure difference between the anode and the cathode. Therefore, the hydrogen system according to the present embodiment is less likely to overflow the anode, and can suppress a decrease in efficiency of the hydrogen compression operation at the time of restarting.

In addition, it is conceivable to perform a gas purging operation on the anode at the time of stopping as in patent document 1 in order to suppress flooding of the anode, or to perform a gas purging operation for eliminating this problem at the time of restarting the hydrogen system, assuming that flooding of the anode occurs at the time of stopping. However, in the hydrogen system according to the present invention, by making the pressure of the anode higher than the pressure of the cathode, it is possible to diffuse water present at the anode to the cathode, or to reduce back diffusion of water from the cathode to the anode, as described above. Therefore, the hydrogen system of the present embodiment can cancel the gas purging operation at the time of the stop or the restart. In addition, even when any of the above-described gas purging operations is performed, the hydrogen system of the present embodiment can shorten the period of the gas purging operation.

The hydrogen system according to claim 2 of the present disclosure may be configured such that, on the basis of the hydrogen system according to claim 1: the controller controls the pressure regulator to raise the pressure of the anode, thereby making the pressure of the anode higher than the pressure of the cathode.

The hydrogen system according to claim 3 of the present disclosure may be configured such that, on the basis of the hydrogen system according to claim 2: after the controller controls the pressure regulator to raise the pressure of the anode, when the pressure difference between the anode and the cathode is reduced, the controller controls the pressure regulator to raise the pressure of the anode.

According to this configuration, in the hydrogen system of the present invention, even if the pressure difference between the anode and the cathode is reduced after the pressure of the anode is increased, the pressure of the anode can be further increased, and therefore the pressure difference between the anode and the cathode can be appropriately maintained.

For example, if the temperature of the compressor decreases with the passage of time after the pressure of the anode is raised, water vapor present in the hydrogen-containing gas of the anode may condense. Accordingly, although the diffusion effect of water from the anode to the cathode or the inhibition effect of back diffusion of water from the cathode to the anode may be reduced as the molecular weight of the hydrogen-containing gas present in the anode decreases and the pressure decreases, the hydrogen system of the present embodiment can reduce the possibility of the reduction of the effect by the above-described structure.

The hydrogen system according to claim 4 of the present disclosure may be configured as follows: the pressure regulator includes a gas supply device for supplying gas to the anode, and the controller controls the gas supply device to supply gas to the anode in a state where an outlet of the anode is sealed, thereby increasing the pressure of the anode.

According to this configuration, in the hydrogen system of the present invention, the pressure of the anode can be appropriately increased by using the supply pressure of the gas supplied to the anode in a state where the outlet of the anode is sealed.

The hydrogen system according to claim 5 of the present disclosure may be configured as follows: the pressure regulator regulates the pressure of the anode and the cathode, and the controller controls the pressure regulator to raise the pressure of the anode and to reduce the pressure of the cathode, thereby making the pressure of the anode higher than the pressure of the cathode

According to this configuration, the hydrogen system of the present embodiment can easily maintain the pressure difference between the anode and the cathode, compared to the case where the pressure of the anode is higher than the pressure of the cathode by only reducing the pressure of the cathode or the case where the pressure of the anode is higher than the pressure of the cathode by only increasing the pressure of the anode. Thus, the hydrogen system according to the present embodiment can further suppress the decrease in efficiency of the hydrogen compression operation at the time of restarting.

The hydrogen system according to claim 6 of the present disclosure may be configured such that, on the basis of the hydrogen system according to claim 5: after the controller controls the pressure regulator to raise the pressure of the anode and to reduce the pressure of the cathode, when the pressure difference between the anode and the cathode is reduced, the controller controls the pressure regulator to raise the pressure of the anode.

According to this configuration, in the hydrogen system of the present embodiment, even if the pressure difference between the anode and the cathode is reduced after the pressure of the anode is increased and the pressure of the cathode is reduced, the pressure of the anode can be further increased, and therefore the pressure difference between the anode and the cathode can be appropriately maintained.

The hydrogen system according to claim 7 of the present disclosure may be configured such that, on the basis of the hydrogen system according to claim 5: after the controller controls the pressure regulator to raise the pressure of the anode and to reduce the pressure of the cathode, when the pressure difference between the anode and the cathode is reduced, the controller controls the pressure regulator to reduce the pressure of the cathode.

According to this configuration, in the hydrogen system of the present invention, even if the pressure difference between the anode and the cathode is reduced after the pressure of the anode is increased and the pressure of the cathode is reduced, the pressure of the cathode can be further reduced, and therefore the pressure difference between the anode and the cathode can be appropriately maintained.

The hydrogen system according to claim 8 of the present disclosure may be configured as follows: the pressure regulator includes a gas supply unit for supplying a gas to the anode, and a 1 st valve for discharging a cathode gas containing compressed hydrogen from the cathode to a different portion from the anode, and the controller controls the gas supply unit to supply the gas to the anode to raise the pressure of the anode while sealing the outlet of the anode, and the controller opens the 1 st valve to lower the pressure of the cathode.

According to this configuration, in the hydrogen system of the present invention, the pressure of the anode can be appropriately increased by using the supply pressure of the gas supplied to the anode in a state where the outlet of the anode is sealed. The 1 st valve functions as a valve for allowing high-pressure cathode gas to escape from the cathode to a position different from the anode. Thus, in the hydrogen system according to the present embodiment, the pressure of the cathode can be appropriately reduced by opening the 1 st valve.

The hydrogen system according to claim 9 of the present disclosure may be configured such that, on the basis of the hydrogen system according to claim 5 or 6: the pressure regulator includes a gas supplier for supplying gas to the anode, and a 2 nd valve for supplying cathode gas containing compressed hydrogen from the cathode to the anode, and the controller opens the 2 nd valve to reduce the pressure of the cathode, and then, in a state where the outlet of the anode is sealed, controls the gas supplier to supply gas to the anode to raise the pressure of the anode.

According to this configuration, in the hydrogen system of the present invention, the pressure of the anode can be appropriately increased by using the supply pressure of the gas supplied to the anode in a state where the outlet of the anode is sealed. In the hydrogen system according to the present embodiment, the pressure of the cathode can be reduced so that the pressure of the cathode approaches the pressure of the anode by opening the 2 nd valve.

Here, the 2 nd valve functions as a valve for controlling the supply of the cathode gas from the cathode to the anode. Thus, in the hydrogen system according to the present embodiment, the cathode gas is supplied from the cathode to the anode by using the 2 nd valve, and the supply amount of the gas supplied from the gas supplier to the anode for increasing the pressure of the cathode is reduced as compared with the case where the cathode gas is not supplied.

The hydrogen system according to claim 10 of the present disclosure may be configured such that, on the basis of the hydrogen system according to claim 5 or 7: the pressure regulator includes a 2 nd valve for supplying a cathode gas containing compressed hydrogen from the cathode to the anode, and a 1 st valve for discharging the cathode gas to a different portion from the anode, and the controller opens the 2 nd valve to raise the pressure of the anode and then opens the 1 st valve to reduce the pressure of the cathode in a state where the outlet of the anode is sealed.

According to this configuration, in the hydrogen system of the present invention, the pressure of the anode can be appropriately increased by the pressure of the cathode gas in a state where the outlet of the anode is sealed by opening the 2 nd valve, and then the pressure of the cathode can be further reduced by opening the 1 st valve, whereby the pressure of the anode is made higher than the pressure of the cathode.

The hydrogen system according to claim 11 of the present disclosure may be configured as follows: the hydrogen-containing gas discharged from the anode flows through the discharge path, and the 3 rd valve is provided in the discharge path, and the controller closes the 3 rd valve to seal the outlet of the anode.

According to this configuration, in the hydrogen system of the present invention, the 3 rd valve provided in the discharge path is closed, so that the outlet of the anode can be easily sealed.

The hydrogen system according to claim 12 of the present disclosure may be configured such that, on the basis of the hydrogen system according to any one of claims 1 to 3 and 5 to 7: the controller controls the pressure regulator to make the pressure of the anode less than 1MPa.

According to this configuration, in the hydrogen system of the present invention, the pressure of the anode is made smaller than 1MPa in terms of gauge pressure (gauge pressure) based on the atmospheric pressure, and thus the components connected to the anode in the hydrogen-containing gas supply system and the gas line of the anode can be easily configured in a low-pressure specification, compared with the case where the pressure of the anode is made 1MPa or more in terms of gauge pressure, whereby the cost of the apparatus can be reduced.

The hydrogen system according to claim 13 of the present disclosure may be configured as follows: the gas supplier supplies a gas different from the hydrogen-containing gas.

The hydrogen system according to claim 14 of the present disclosure may be configured such that, in addition to the hydrogen system according to any one of claims 5 to 7: the pressure regulator includes a voltage applicator for applying a voltage between the anode and the cathode, and the controller controls the voltage applicator in a state where the inlet and the outlet of the anode are sealed, and applies a voltage opposite to that before stopping between the anode and the cathode, thereby increasing the pressure of the anode and decreasing the pressure of the cathode.

According to this configuration, in the hydrogen system of the present invention, when the anode is stopped, the anode is sealed from the inlet and the outlet, and the proton is moved from the cathode to the anode via the electrolyte membrane by the application of the voltage between the anode and the cathode opposite to that before the stop, so that the pressure of the anode can be increased and the pressure of the cathode can be reduced.

A method for operating a hydrogen system according to claim 15 of the present disclosure includes: a step of generating compressed hydrogen by applying a voltage between an anode and a cathode provided so as to sandwich an electrolyte membrane, and moving hydrogen in a hydrogen-containing gas supplied to the anode to the cathode; and a step of making the pressure of the anode higher than the pressure of the cathode in a state where the hydrogen-containing gas is sealed from flowing out of the anode when the hydrogen system is stopped.

Thus, the operation method of the hydrogen system according to the present invention can suppress a decrease in efficiency of the hydrogen compression operation at the time of restarting, as compared with the conventional method.

The details of the operation effects of the operation method of the hydrogen system according to the present invention can be easily understood with reference to the operation effects of the hydrogen system according to claim 1, and therefore, the description thereof will be omitted.

The operation method of the hydrogen system according to claim 16 of the present disclosure may be configured as follows: by raising the pressure of the anode, the pressure of the anode is made higher than the pressure of the cathode.

The operation method of the hydrogen system according to claim 17 of the present disclosure may be configured as follows: the pressure of the anode is made higher than the pressure of the cathode by raising the pressure of the anode and reducing the pressure of the cathode.

The operational effects of the operation method of the hydrogen system according to the present invention can be easily understood with reference to the operational effects of the hydrogen system according to claim 5, and therefore, the description thereof will be omitted.

The operation method of the hydrogen system according to claim 18 of the present disclosure may be the operation method of the hydrogen system according to claim 16 or 17, wherein: by supplying gas to the anode, the pressure of the anode is raised.

The operational effects of the operation method of the hydrogen system according to the present invention can be easily understood with reference to the operational effects of the hydrogen system according to claim 4, and therefore, the description thereof will be omitted.

The operation method of the hydrogen system according to claim 19 of the present disclosure may be the operation method of the hydrogen system according to claim 17, wherein: by discharging the cathode gas containing the compressed hydrogen from the cathode, the pressure of the cathode is reduced.

The operational effects of the operation method of the hydrogen system according to the present invention can be easily understood with reference to the operational effects of the hydrogen system according to claim 8 or 9, and therefore the description thereof will be omitted.

The operation method of the hydrogen system according to claim 20 of the present disclosure may be the operation method of the hydrogen system according to claim 18, wherein: the pressure of the anode is raised by supplying a gas other than the hydrogen-containing gas to the anode.

Embodiments of the present disclosure will be described below with reference to the drawings. The embodiments described below are only examples of the above-described embodiments. Accordingly, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components, and the like shown below are only examples, and the respective embodiments are not limited to those described in the claims. Among the following components, the components not described in the independent claims showing the uppermost concept of the present invention will be described as arbitrary components. In the drawings, the same reference numerals are attached to the same elements, and the description thereof may be omitted. In the drawings, since each constituent element is schematically shown for easy understanding, the shape, the dimensional ratio, and the like may not be accurately shown. The order of the steps may be changed as needed during the operation, and other known steps may be added.

(embodiment 1)

In the following embodiments, a configuration and an operation of a hydrogen system including an electrochemical hydrogen pump as an example of the compressor will be described. In the following embodiments, the gauge pressure based on the atmospheric pressure is indicated.

[ device Structure ]

In the example shown in fig. 1, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, a pressure regulator 20, and a controller 50.

Here, the electrochemical hydrogen pump 100 includes AN electrolyte membrane 10, AN anode AN, and a cathode CA. The electrochemical hydrogen pump 100 may include a stack (stack) of a plurality of MEAs (cells). Details will be described later.

Anode AN is provided on one main surface of electrolyte membrane 10. Anode AN is AN electrode comprising AN anode catalyst layer and AN anode gas diffusion layer. The cathode CA is provided on the other main surface of the electrolyte membrane 10. The cathode CA is an electrode including a cathode catalyst layer and a cathode gas diffusion layer. Thus, the electrolyte membrane 10 is sandwiched between the anode AN and the cathode CA so as to be in contact with the anode catalyst layer and the cathode catalyst layer, respectively.

The electrolyte membrane 10 may have any structure as long as it has proton conductivity. For example, the electrolyte membrane 10 may be a fluorine-based polymer electrolyte membrane, a hydrocarbon-based electrolyte membrane, or the like. Specifically, for example, nafion (registered trademark, manufactured by dupont) or Aciplex (registered trademark, manufactured by asahi chemical corporation) may be used as the electrolyte membrane 10, but the present invention is not limited thereto.

The anode catalyst layer is provided on one main surface of the electrolyte membrane 10. The anode catalyst layer contains carbon capable of supporting a catalyst metal (e.g., platinum) in a dispersed state, but is not limited thereto.

The cathode catalyst layer is provided on the other main surface of the electrolyte membrane 10. The cathode catalyst layer contains carbon capable of supporting a catalyst metal (e.g., platinum) in a dispersed state, but is not limited thereto.

The preparation method of the catalyst is not particularly limited, and various methods may be used for the cathode catalyst layer and the anode catalyst layer. Examples of the carbon-based powder include graphite, carbon black, and conductive activated carbon. The method for supporting platinum or other catalyst metal on the carbon support is not particularly limited. For example, powder mixing, liquid phase mixing, or the like may be employed. Examples of the latter liquid phase mixing include a method of dispersing and adsorbing a carrier such as carbon in a colloidal liquid as a catalyst component. The state of supporting the catalyst metal such as platinum on the carbon support is not particularly limited. For example, the catalyst metal may be finely divided and supported on a carrier in a highly dispersed manner.

The cathode gas diffusion layer is disposed on the cathode catalyst layer. The cathode gas diffusion layer is made of a porous material and has conductivity and gas diffusivity. The cathode gas diffusion layer preferably has elasticity capable of appropriately following displacement and deformation of the constituent members due to a pressure difference between the cathode CA and the anode AN during operation of the electrochemical hydrogen pump 100. As a base material of the cathode gas diffusion layer, for example, a carbon fiber sintered body or the like can be used, but the invention is not limited thereto.

The anode gas diffusion layer is disposed on the anode catalyst layer. The anode gas diffusion layer is made of a porous material and has conductivity and gas diffusivity. The anode gas diffusion layer preferably has rigidity to such an extent that it can withstand the compression of the electrolyte membrane 10 by the pressure difference during operation of the electrochemical hydrogen pump 100. As the base material of the anode gas diffusion layer, for example, a carbon particle sintered body, a titanium sintered body, or the like can be used, but the invention is not limited thereto.

The electrochemical hydrogen pump 100 described above is a device that generates compressed hydrogen by applying a voltage between the anode AN and the cathode CA, which are provided so as to sandwich the electrolyte membrane 10, to move hydrogen in the hydrogen-containing gas supplied to the anode AN to the cathode CA. The hydrogen-containing gas may be, for example, hydrogen gas generated by electrolysis of water, or a modified gas generated by a modification reaction of hydrocarbon gas. The voltage may be applied by a voltage applicator, not shown. A specific example of such a voltage applicator is described in embodiment 7.

The pressure regulator 20 is a device that regulates at least the pressure of the anode AN. The pressure regulator 20 may have any structure as long as it can regulate the pressure of the anode AN. A specific example of such a pressure regulator 20 is described in example 3 of this embodiment.

The controller 50 controls the pressure regulator 20 so that the pressure of the anode AN is higher than the pressure of the cathode CA while the flow of the hydrogen-containing gas from the anode AN is blocked at the time of stopping. In this case, the outlet of the cathode CA is sealed by closing a cathode valve (not shown) by the controller 50. The controller 50 may control the operation of the overall hydrogen system 200. Here, "at the time of stop" means after the supply of the cathode gas containing the compressed hydrogen from the cathode CA of the electrochemical hydrogen pump 100 to the hydrogen demand body (not shown) is stopped. Examples of the hydrogen demand body include a hydrogen storage, a piping of a hydrogen infrastructure, and a fuel cell. Examples of the hydrogen storage device include a hydrogen cylinder. The "pressure of anode AN" and "pressure of cathode CA" refer to the pressure of each of the gas flow path communicating with anode AN and the gas flow path communicating with cathode CA, respectively. A specific example for realizing "the state of sealing off the hydrogen-containing gas from the anode AN" will be described later.

The controller 50 includes, for example, an arithmetic circuit (not shown) and a memory circuit (not shown) storing a control program. Examples of the arithmetic circuit include an MPU and a CPU. Examples of the memory circuit include a memory. The controller 50 may be a single controller for performing centralized control, or may be a plurality of controllers for performing decentralized control in cooperation with each other.

Here, although not shown in the drawings, components and devices required in the hydrogen compression operation of the hydrogen system 200 may be appropriately provided.

For example, in the electrochemical hydrogen pump 100, the anode AN and the cathode CA may be sandwiched from the outside by a pair of separators, respectively. In this case, the separator in contact with the anode AN is a plate-like member having conductivity for supplying the hydrogen-containing gas to the anode AN. The plate-like member includes a serpentine-like (serpentine) gas flow path through which the hydrogen-containing gas supplied to the anode AN flows. The separator in contact with the cathode CA is a plate-like member having conductivity for leading hydrogen from the cathode CA. The plate-like member is provided with a gas flow path through which hydrogen led out from the cathode CA flows.

In the electrochemical hydrogen pump 100, a sealing material such as a gasket is generally provided from both sides of the cell so as not to leak high-pressure hydrogen to the outside, and is assembled in advance in an integrated manner with the cell of the electrochemical hydrogen pump 100. The separator is disposed outside the cells to mechanically fix the cells and electrically connect adjacent cells to each other in series.

In a typical laminated structure, approximately 10 to 200 cells are stacked alternately with separators, and a laminate (cell group) thereof is sandwiched between end plates via a current collector plate and an insulating plate, and the two end plates are fastened by fastening rods. In this case, in order to supply an appropriate amount of hydrogen-containing gas to each of the gas passages of the separators, it is necessary to branch out a groove-like branch path from an appropriate line in each of the separators, and connect the downstream ends of the branch paths to one end of each of the gas passages of the separators. In order to discharge an appropriate amount of hydrogen-containing gas from each of the gas passages of the separators, it is necessary to branch out a groove-like branch path from an appropriate line in each of the separators, and to connect the upstream ends of the branch paths to the other end of each of the gas passages of the separators. In order to discharge the high-pressure cathode gas from the respective cathodes of the separators, it is necessary to branch the respective separators into a groove-like branch path from an appropriate line, and to connect the upstream ends of the branch paths to the respective cathodes of the separators.

Such a pipe is called a manifold (header pipe), and the manifold is formed by, for example, connecting through holes provided at appropriate positions of the respective members constituting the unit group.

The hydrogen system 200 may be provided with a temperature detector for detecting the temperature of the unit, a temperature regulator for regulating the temperature of the unit, a dew point regulator for regulating the dew point of the hydrogen-containing gas supplied to the anode AN, and the like.

The above-described components and devices not shown are merely examples, and are not limited to the present example.

Work

An example of the hydrogen compression operation of the hydrogen system 200 will be described below with reference to the drawings. The following operations may be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. The following operations are not necessarily performed by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

First, a low-pressure and high-humidity hydrogen-containing gas is supplied to the anode AN of the electrochemical hydrogen pump 100, and a voltage of a voltage applicator, not shown, is supplied to the electrochemical hydrogen pump 100. Then, in the anode catalytic layer of the anode AN, hydrogen molecules are separated into protons and electrons (formula (1)). Protons are conducted within the electrolyte membrane 10 and move to the cathode catalyst layer. Electrons are moved to the cathode catalyst layer by the voltage applicator.

Then, in the cathode catalyst layer, hydrogen molecules are generated again (formula (2)). In addition, it is known that when protons move within the electrolyte membrane 10, a predetermined amount of water reaches the cathode CA as electro-osmotic water along with the protons from the anode AN.

In this case, for example, when compressed hydrogen at a high pressure generated at the cathode CA of the electrochemical hydrogen pump 100 is supplied to a hydrogen storage device (not shown) through a cathode gas discharge passage (not shown), the pressure loss in the cathode gas discharge passage is increased by a back pressure valve, an adjustment valve (not shown) or the like provided in the cathode gas discharge passage, whereby the hydrogen (H ₂ ) And (5) compressing. Here, the increase in the pressure loss in the cathode gas discharge passage corresponds to the decrease in the opening of the back pressure valve and the adjustment valve provided in the cathode gas discharge passage.

Anode: h ₂ (Low pressure) →2H ⁺ +2e ^- ···(1)

And (3) cathode: 2H (H) ⁺ +2e ^- →H ₂ (high pressure) · (2)

In this way, in the hydrogen system 200, by applying a voltage between the anode AN and the cathode CA provided so as to sandwich the electrolyte membrane 10, AN operation is performed in which hydrogen in the hydrogen-containing gas supplied to the anode AN is moved to the cathode CA, thereby generating compressed hydrogen. The cathode gas containing compressed hydrogen generated at the cathode CA is temporarily stored in a hydrogen storage after, for example, removing moisture, impurities, and the like in the cathode gas.

Next, the operation of the hydrogen system 200 is stopped. Specifically, for example, the supply of the cathode gas from the cathode CA of the electrochemical hydrogen pump 100 to the hydrogen storage tank is stopped by closing a back pressure valve and an adjustment valve provided in the cathode gas discharge passage.

Here, in the case where the electrochemical hydrogen pump 100 is a compressor for a fuel cell forklift, for example, a cathode gas having a high pressure of about 40MPa is generally present on the cathode CA side. In addition, a hydrogen-containing gas having a low pressure of about 0.1MPa and a high humidity (for example, a saturated water vapor pressure of about 50 ℃ and a water vapor content of about 12% in the gas when the relative humidity is 100%) is present on the anode AN side. Therefore, in the hydrogen system 200 of the present embodiment, when the hydrogen system 200 is stopped, the operation is performed to make the pressure of the anode AN higher than the pressure of the cathode CA.

The cathode gas stored in the hydrogen storage device can be supplied to the fuel cell or the like at a proper timing.

As described above, the hydrogen system 200 and the operation method of the hydrogen system 200 according to the present embodiment can suppress the efficiency of the hydrogen compression operation at the time of restarting from being lowered as compared with the conventional one.

Specifically, the hydrogen system 200 and the operation method of the hydrogen system 200 according to the present embodiment control the pressure regulator 20 so that the pressure of the anode AN is higher than the pressure of the cathode CA while the flow of the hydrogen-containing gas from the anode AN is blocked at the time of stopping. This can suppress back diffusion of water from the cathode CA to the anode AN during the stop of the hydrogen system 200. In addition, when the anode AN generates condensed water, the condensed water can be diffused from the anode AN to the cathode CA by a pressure difference between the anode AN and the cathode CA. Therefore, the hydrogen system 200 according to the present embodiment is less likely to overflow the anode AN, and can suppress a decrease in the efficiency of the hydrogen compression operation at the time of restarting.

In order to suppress flooding of the anode AN, it is conceivable to perform a gas purging operation for the anode AN at the time of stopping as in patent document 1, or to perform a gas purging operation for eliminating flooding at the time of restarting the hydrogen system 200 if flooding occurs at the anode AN at the time of stopping. However, in the hydrogen system 200 of the present embodiment, by making the pressure of the anode AN higher than the pressure of the cathode CA, it is possible to diffuse water present in the anode to the cathode CA or to reduce back diffusion of water from the cathode CA to the anode AN as described above. Therefore, the hydrogen system 200 according to the present embodiment can eliminate the gas purging operation at the time of stopping or restarting. In addition, even when any of the above-described gas purging operations is performed, the hydrogen system 200 of the present embodiment can shorten the period of the gas purging operation.

In addition, if the pressure of the cathode CA is higher than the pressure of the anode AN at the time of stopping the hydrogen system 200, there is a possibility that the portion of the electrolyte membrane 10 on the cathode CA side may be changed in dry and wet due to back diffusion of water from the cathode CA to the anode AN. Thus, repeated swelling and shrinkage at the portion of the electrolyte membrane 10 may cause a decrease in durability of the electrolyte membrane 10. However, in the hydrogen system 200 of the present embodiment, the pressure of the anode AN is made higher than the pressure of the cathode CA at the time of stopping the hydrogen system 200, so that the above-described drawbacks can be alleviated.

(example 1)

The hydrogen system 200 and the operation method of the hydrogen system 200 of the present embodiment are the same as those of the hydrogen system 200 of embodiment 1 except for the control contents of the controller 50 described below.

The controller 50 increases the pressure of the anode AN by controlling the pressure regulator 20 to raise the pressure of the anode AN at the time of stopping the hydrogen system 200 so that the pressure of the anode AN is higher than the pressure of the cathode CA.

The operation and effects of the hydrogen system 200 and the operation method of the hydrogen system 200 in this example are the same as those of the hydrogen system 200 and the operation method of the hydrogen system 200 in embodiment 1, and therefore, the description thereof will be omitted.

The hydrogen system 200 and the operation method of the hydrogen system 200 of the present embodiment may be the same as embodiment 1 except for the above-described features.

(example 2)

The hydrogen system 200 of the present example is the same as the hydrogen system 200 of embodiment 1, except for the control contents of the controller 50 described below.

The controller 50 controls the pressure regulator 20 to raise the pressure of the anode AN when the pressure difference between the anode AN and the cathode CA is reduced after controlling the pressure regulator 20 to raise the pressure of the anode AN at the time of stopping the hydrogen system 200.

As described above, in the hydrogen system 200 of the present embodiment, even if the pressure difference between the anode AN and the cathode CA is reduced after the pressure of the anode AN is raised, the pressure of the anode AN can be further raised, and therefore the pressure difference between the anode AN and the cathode CA can be appropriately maintained.

For example, if the temperature of the electrochemical hydrogen pump 100 decreases with time after the pressure of the anode AN is raised, water vapor present in the hydrogen-containing gas of the anode AN may condense. Accordingly, with the decrease in the molecular weight of the hydrogen-containing gas present in the anode AN, the pressure decreases, and the pressure difference between the anode AN and the cathode CA decreases, so that the diffusion effect of water from the anode AN to the cathode CA or the inhibition effect of back diffusion of water from the cathode CA to the anode AN may decrease.

The hydrogen system 200 of the present embodiment may be the same as embodiment 1 or embodiment 1 except for the above-described features.

(example 3)

In the example shown in fig. 2, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, a pressure regulator 20, an anode supply path 21, an anode inlet valve 27, and a controller 50. Here, the electrochemical hydrogen pump 100 is the same as in embodiment 1.

The anode supply path 21 is a flow path through which the gas supplied to the anode AN of the electrochemical hydrogen pump 100 flows.

The pressure regulator 20 is a device including a gas supply 20A. The gas supply device 20A is provided in the anode supply path 21. The gas supplier 20A is a device for supplying gas to the anode AN. The gas supplier 20A may have any structure as long as it can supply gas to the anode AN. Examples of the gas supply device 20A include a pump, a switch valve, and a pressure reducing valve. When the gas supply device 20A is a switching valve or a pressure reducing valve, the anode supply path 21 is connected to a gas supply source having a predetermined supply pressure. As a gas supply source having a predetermined supply pressure, a gas cylinder may be exemplified. The gas supplier 20A may supply the hydrogen-containing gas to the anode AN, or may supply a gas different from the hydrogen-containing gas. Details of the latter will be described in embodiment 6.

The anode inlet valve 27 is a valve provided in the anode supply path 21 upstream of the pressure regulator 20. The anode inlet valve 27 may have any structure as long as it can cut off the anode supply path 21. As the anode inlet valve 27, for example, a drive valve or a solenoid valve driven by nitrogen gas, air, or the like can be used, but the present invention is not limited thereto.

In this embodiment, the controller 50 controls the gas supplier 20A to supply gas to the inlet of the anode AN in a state where the outlet of the anode AN is sealed, thereby increasing the pressure of the anode AN. After raising the pressure of anode AN, anode inlet valve 27 provided in anode supply path 21 is closed.

In this embodiment, when the gas is supplied to the inlet of the anode AN, the "state in which the outlet of the anode AN is sealed" is achieved, and the "state in which the hydrogen-containing gas flows out from the anode AN" is achieved. For example, when the gas is supplied to the inlet of the anode AN, if the anode discharge path communicating with the outlet of the anode AN is cut off, the outlet of the anode AN can be sealed. Such cutting of the anode discharge path may be performed by an anode outlet valve provided in the anode discharge path. A specific example of the anode discharge path and the anode outlet valve will be described in embodiment 3.

As described above, the hydrogen system 200 and the operation method of the hydrogen system 200 according to the present embodiment can appropriately raise the pressure of the anode AN by using the supply pressure of the gas supplied to the anode AN in a state where the outlet of the anode AN is sealed.

The hydrogen system 200 of the present example may be the same as the hydrogen system 200 of any one of embodiment 1 and 1 st to 2 nd examples of embodiment 1, except for the above-described features.

(embodiment 2)

In the example shown in fig. 3, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, a pressure regulator 20, and a controller 50. Here, the electrochemical hydrogen pump 100 is the same as in embodiment 1.

The pressure regulator 20 is a device for regulating the pressures of the anode AN and the cathode CA. The pressure regulator 20 may have any structure as long as it can regulate the pressures of the anode AN and the cathode CA. Further, a specific example of such a pressure regulator 20 will be described in example 3 of this embodiment.

In the present embodiment, the controller 50 controls the pressure regulator 20 to raise the pressure of the anode AN and to reduce the pressure of the cathode CA at the time of stopping the hydrogen system 200, thereby making the pressure of the anode AN higher than the pressure of the cathode CA.

As described above, the hydrogen system 200 and the operation method of the hydrogen system 200 according to the present embodiment can maintain the pressure difference between the anode AN and the cathode CA more easily than the case where the pressure of the anode AN is higher than the pressure of the cathode CA by the pressure reduction of only the cathode CA or the case where the pressure of the anode AN is higher than the pressure of the cathode CA by the pressure increase of only the anode AN. Thus, the hydrogen system 200 according to the present embodiment can further suppress a decrease in efficiency of the hydrogen compression operation at the time of restarting.

In addition, the order of the operation of raising the pressure of the anode AN and the operation of reducing the pressure of the cathode CA is arbitrary. The operation of raising the pressure of the anode AN may be performed after the operation of reducing the pressure of the cathode CA as in example 3 of the present embodiment, or the operations may be performed in the reverse order as in the modification of the present embodiment, or may be performed so as to overlap in time.

The hydrogen system 200 and the operation method of the hydrogen system 200 according to the present embodiment may be the same as any of embodiment 1 and embodiment 1 to embodiment 3 except for the above-described features.

(example 1)

The hydrogen system 200 of the present example is the same as the hydrogen system 200 of embodiment 2, except for the control contents of the controller 50 described below.

After the controller 50 controls the pressure regulator 20 to raise the pressure of the anode AN and reduce the pressure of the cathode CA, the controller 50 controls the pressure regulator 20 to raise the pressure of the anode AN when the pressure difference between the anode AN and the cathode CA decreases.

As described above, in the hydrogen system 200 of the present embodiment, even if the pressure difference between the anode AN and the cathode CA is reduced after the pressure of the anode AN is increased and the pressure of the cathode CA is reduced, the pressure of the anode AN can be further increased, and therefore the pressure difference between the anode AN and the cathode CA can be appropriately maintained.

The hydrogen system 200 of the present example may be the same as any of embodiment 1, examples 1 to 3, and embodiment 2 except for the above-described features.

(example 2)

After the controller 50 controls the pressure regulator 20 to raise the pressure of the anode AN and to lower the pressure of the cathode CA, when the pressure difference between the anode AN and the cathode CA is reduced, the controller 50 controls the pressure regulator 20 to lower the pressure of the cathode CA.

As described above, in the hydrogen system 200 of the present embodiment, even if the pressure difference between the anode AN and the cathode CA is reduced after the pressure of the anode AN is increased and the pressure of the cathode CA is reduced, the pressure of the cathode CA can be further reduced, and therefore the pressure difference between the anode AN and the cathode CA can be appropriately maintained.

The hydrogen system 200 of the present example may be the same as any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, and embodiment 2, embodiment 1 except for the above-described features.

(example 3)

In the example shown in fig. 4, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, a pressure regulator 20, an anode supply path 21, an anode discharge path 22, an anode inlet valve 27, and a controller 50. Here, the electrochemical hydrogen pump 100 is the same as in embodiment 1. The anode supply path 21 and the anode inlet valve 27 are the same as those of embodiment 3 of embodiment 1.

The pressure regulator 20 is a device including a gas supply 20A and a cathode valve 20B. Here, the gas supplier 20A is the same as in example 3 of embodiment 1.

The cathode valve 20B is a valve for discharging cathode gas containing compressed hydrogen from the cathode CA to a different location from the anode AN. The cathode valve 20B may have any structure as long as it can discharge the cathode gas to a different location from the anode AN. Examples of the location different from the anode AN include, but are not limited to, the atmosphere.

Examples of the cathode valve 20B include an on-off valve and an adjustment valve for controlling the opening degree of the valve. The regulating valve may be a pressure regulating valve or a flow regulating valve. As the cathode valve 20B, for example, a drive valve or a solenoid valve driven by nitrogen gas, air, or the like can be used, but the present invention is not limited thereto. In addition, the cathode valve 20B corresponds to one example of the "1 st valve" of the present disclosure.

The anode discharge path 22 is a flow path through which the gas discharged from the anode AN of the electrochemical hydrogen pump 100 flows. The cathode valve 20B is provided in the anode discharge path 22.

In the present embodiment, in a state where the outlet of the anode AN is sealed, the controller 50 increases the pressure of the anode AN by controlling the gas supply device 20A to supply gas to the inlet of the anode AN, and the controller 50 decreases the pressure of the cathode CA by opening the cathode valve 20B.

In this embodiment, when the gas is supplied to the inlet of the anode AN, the "state in which the outlet of the anode AN is sealed" is achieved, and the "state in which the hydrogen-containing gas flows out from the anode AN is sealed". For example, when the gas is supplied to the inlet of the anode AN, if the anode discharge path communicating with the outlet of the anode AN is cut off, the outlet of the anode AN can be sealed. Such cutting of the anode discharge path may be performed by an anode outlet valve provided in the anode discharge path. A specific example of the anode discharge path and the anode outlet valve will be described in embodiment 3.

Fig. 5 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 3 of embodiment 2. The operation shown in fig. 5 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

When the stop control of the hydrogen system 200 is started, the supply of the cathode gas from the cathode CA of the electrochemical hydrogen pump 100 to the hydrogen demand body (not shown) is stopped. At this time, the cathode valve 20B is in a closed state, and the operation of the gas supplier 20A is stopped. In this case, the anode inlet valve 27 may be opened or closed, and in this example, the case where the anode inlet valve 27 is in an open state will be described.

First, the cathode valve 20B is opened in step S1. Then, after "predetermined time a" has elapsed from the time of opening of the cathode valve 20B in step S2, the cathode valve 20B is closed in step S3. The "predetermined time a" in step S2 is, for example, an arbitrary time from about 1 second to about 1 hour, but is not limited thereto. At this time, as the "predetermined time a" of step S2, a time measured by a timer of the controller 50 may be employed. However, the above operation is merely illustrative and is not limited to this example. For example, instead of the "predetermined time a" of step S2, the above-described operation may be performed based on the pressure of the cathode CA. Details of this operation will be described in embodiment 4.

In steps S1 to S3, if the cathode valve 20B is an on-off valve, the pressure of the cathode CA can be gradually reduced by repeating the on-off operation of the cathode valve 20B. In addition, if the cathode valve 20B is a pressure adjustment valve or a flow rate adjustment valve, the pressure of the cathode CA can be gradually reduced by performing pressure adjustment and flow rate adjustment based on the valve opening. The reason for gradually decreasing the pressure of the cathode CA is that if the pressure of the cathode CA is opened at once, there is a possibility that the high-pressure standard equipment and components in the electrochemical hydrogen pump 100 may be damaged.

Next, in step S4, the gas supplier 20A operates. Then, after "predetermined time B" has elapsed from the operation of the gas supplier 20A in step S5, the operation of the gas supplier 20A is stopped in step S6, and the anode inlet valve 27 is closed in step S16. The "predetermined time B" in step S5 is, for example, any time from about 10 seconds to about 300 seconds, but is not limited thereto. At this time, as the "predetermined time B" of step S5, a time measured by a timer of the controller 50 may be used. The above operation is merely illustrative, and is not limited to this example. For example, instead of the "predetermined time B" of step S2, the above-described operation may be performed based on the pressure difference between the anode AN and the cathode CA. Details of this operation will be described in embodiment 4.

Thus, the stop control of the hydrogen system 200 is completed.

As described above, in the hydrogen system 200 of the present embodiment, the pressure of the anode AN can be appropriately increased by using the supply pressure of the gas supplied to the anode AN in a state where the outlet of the anode AN is sealed. The cathode valve 20B functions as a valve for allowing the cathode gas of high pressure to escape from the cathode CA to a different portion from the anode AN. Thus, the hydrogen system 200 of the present embodiment can appropriately reduce the pressure of the cathode CA by opening the cathode valve 20B.

The hydrogen system 200 of the present example may be the same as any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, and embodiment 2, except for the above-described features.

(example 4)

Fig. 6 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 4 of embodiment 2. The operation shown in fig. 6 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

Here, the contents of steps S1 to S16 in fig. 6 are the same as those of steps S1 to S16 in fig. 5, and thus detailed description thereof is omitted.

First, in step S7, after "predetermined time C" has elapsed since the stop control of the hydrogen system 200 was completed, the anode inlet valve 27 is opened in step S26, and the gas supplier 20A is operated in step S104. Then, after "predetermined time BB" has elapsed in step S105 since the operation of the gas supplier 20A, the operation of the gas supplier 20A is stopped in step S106, and the anode inlet valve 27 is closed in step S116. The "predetermined time C" in step S7 is, for example, about 1 hour, but is not limited thereto. At this time, as the "predetermined time C" of step S7, a time measured by a timer of the controller 50 may be employed. The "predetermined time BB" of step S105 in fig. 5 is the same as the "predetermined time B" of step S5 in fig. 4. The hydrogen system 200 may then begin the start-up control at a timely time.

As described above, in the hydrogen system 200 of the present embodiment, even if the pressure difference between the anode AN and the cathode CA decreases due to the temperature of the electrochemical hydrogen pump 100 decreasing with the lapse of the predetermined time C after the pressure of the cathode CA is reduced and the pressure of the anode AN is increased, the pressure difference between the anode AN and the cathode CA can be further increased, and therefore, the pressure difference between the anode AN and the cathode CA can be appropriately maintained.

The hydrogen system 200 of the present example may be the same as any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, and embodiment 2, embodiment 1 to embodiment 3, except for the above-described features.

(example 5)

Fig. 7 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 5 of embodiment 2. The operation shown in fig. 7 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

Here, the contents of steps S1 to S16 in fig. 7 are the same as those of steps S1 to S16 in fig. 5, and thus detailed description thereof is omitted.

After "predetermined time C" has elapsed from the completion of the stop control of the hydrogen system 200 in step S7, the cathode valve 20B is opened in step S101. Then, after "predetermined time AA" has elapsed from the time of opening of the cathode valve 20B in step S102, the cathode valve 20B is closed in step S103. The "predetermined time C" in step S7 is, for example, about 1 hour, but is not limited thereto. At this time, as the "predetermined time C" of step S7, a time measured by a timer of the controller 50 may be employed. The "predetermined time AA" in step S102 of fig. 7 is, for example, about 60 seconds, but is not limited thereto. At this time, as the "predetermined time AA" of step S102, a time measured by a timer of the controller 50 may be employed. The hydrogen system 200 may then begin the start-up control at a timely time.

As described above, in the hydrogen system 200 of the present embodiment, even if the pressure difference between the anode AN and the cathode CA decreases due to the temperature of the electrochemical hydrogen pump 100 decreasing with the lapse of the predetermined time C after the pressure of the cathode CA is reduced and after the pressure of the anode AN is increased, the pressure difference between the two can be further maintained, and therefore, the pressure difference between the two can be appropriately maintained.

The hydrogen system 200 of the present example may be the same as any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, and embodiment 2, embodiment 1 to embodiment 4, except for the above-described features.

(modification)

Fig. 8 is a flowchart showing an example of the operation of the hydrogen system according to the modification of embodiment 2. The operation shown in fig. 8 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

In example 3 of embodiment 2, as shown in fig. 5, the operations of steps S1 to S3 are performed before the operations of steps S4 to S16, and in this modification, as shown in fig. 8, the operations of steps S4 to S16 are performed before the operations of steps S1 to S3.

The contents of steps S4 to S16 and steps S1 to S3 in fig. 8 are the same as steps S4 to S16 and steps S1 to S3 in fig. 5, respectively, except for the order of the steps described above. The operation and effect of the hydrogen system 200 according to the modification example are the same as those of the hydrogen system 200 according to embodiment 3 of embodiment 2. Therefore, the description thereof will be omitted.

The hydrogen system 200 of the present example may be the same as any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, and embodiment 2, embodiment 1 to embodiment 5, except for the above-described features.

(embodiment 3)

In the example shown in fig. 9, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, a pressure regulator 20, an anode supply path 21, an anode discharge path 22, an anode outlet valve 23, a cathode discharge path 24, an anode inlet valve 27, and a controller 50. Here, the electrochemical hydrogen pump 100 is the same as in embodiment 1. Otherwise, the pressure regulator 20 and the anode inlet valve 27 are the same as those in embodiment 3 of embodiment 2. In the following example, the case where the hydrogen-containing gas is supplied to the anode AN by the gas supplier 20A will be described, but the present invention is not limited thereto. That is, in this example, the anode supply path 21 is a flow path through which the hydrogen-containing gas supplied to the anode AN of the electrochemical hydrogen pump 100 flows. In the case where the electrochemical hydrogen pump 100 includes the above-described cell group, the downstream end of the anode supply path 21 may be in communication with, for example, a manifold for introducing a hydrogen-containing gas. The upstream end of the anode supply path 21 may be connected to, for example, a hydrogen-containing gas supply source (not shown). Examples of the supply source of the hydrogen-containing gas include a reformer, a water electrolysis apparatus, and a hydrogen cylinder. In this example, the anode discharge path 22 is a flow path through which the hydrogen-containing gas discharged from the anode AN of the electrochemical hydrogen pump 100 flows. In the case where the electrochemical hydrogen pump 100 includes the above-described cell group, the upstream end of the anode discharge path 22 may be in communication with, for example, a manifold for discharging the hydrogen-containing gas.

The anode outlet valve 23 is a valve provided in the anode discharge path 22. The anode outlet valve 23 may have any structure as long as it can cut off the anode discharge path 22. As the anode outlet valve 23, for example, a drive valve or a solenoid valve driven by nitrogen gas, air, or the like can be used, but the present invention is not limited thereto. In addition, the anode outlet valve 23 corresponds to one example of "3 rd valve" of the present disclosure.

The cathode discharge path 24 is a flow path through which the cathode gas discharged from the cathode CA of the electrochemical hydrogen pump 100 flows. The cathode valve 20B is provided in the cathode discharge path 24. In the case where the electrochemical hydrogen pump 100 includes the above-described cell group, the upstream end of the cathode discharge path 24 may be in communication with, for example, a manifold for discharging the cathode gas.

In the present embodiment, the controller 50 closes the anode outlet valve 23 to seal the outlet of the anode AN.

Fig. 10 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 3. The operation shown in fig. 10 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

Here, since the contents of step S1, step S2, and steps S4 to S16 in fig. 10 are the same as those of step S1, step S2, and steps S4 to S16 in fig. 5, detailed description thereof is omitted. In addition, at the start of the stop control of the hydrogen system 200, the cathode valve 20B is in a closed state, and the anode outlet valve 23 is in a closed state. In addition, the operation of the gas supplier 20A is stopped. The anode inlet valve 27 may be opened or closed, and the case where the anode inlet valve 27 is in an open state will be described in this example.

After "predetermined time a" has elapsed from the time of opening of the cathode valve 20B in step S2, the cathode valve 20B is closed in step S31. Thereby sealing the outlet of the anode AN.

As described above, in the hydrogen system 200 according to the present embodiment, the anode outlet valve 23 provided in the anode discharge path 22 is closed, so that the outlet of the anode AN can be easily sealed.

The hydrogen system 200 of the present embodiment may be similar to any of examples 1 to 3, 2, and 1 to 5 of embodiment 1 and 2 of embodiment 1 and 1 to 3 of embodiment 1, and the modified examples of embodiment 2, except for the above-described features.

(embodiment 4)

In the example shown in fig. 11, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, a pressure regulator 20, an anode supply path 21, an anode discharge path 22, an anode outlet valve 23, a cathode discharge path 24, an anode inlet valve 27, a 1 st pressure gauge 30, a 2 nd pressure gauge 31, and a controller 50. Here, the electrochemical hydrogen pump 100 is the same as in embodiment 1. The pressure regulator 20, the anode supply path 21, the anode discharge path 22, the anode outlet valve 23, the anode inlet valve 27, and the cathode discharge path 24 are the same as those of embodiment 3. In the following example, the case where the hydrogen-containing gas is supplied to the anode AN by the gas supplier 20A will be described, but the present invention is not limited thereto.

The 1 st pressure gauge 30 is a sensor for measuring the pressure of the anode AN (hereinafter referred to as anode pressure). The 1 st pressure gauge 30 may have any structure as long as it can measure the anode pressure. In the example shown in fig. 11, the 1 st pressure gauge 30 is provided in the anode supply path 21 downstream of the gas supplier 20A.

The 2 nd pressure gauge 31 is a sensor for measuring the pressure of the cathode CA (hereinafter referred to as cathode pressure). The 2 nd pressure gauge 31 may have any structure as long as it can measure the cathode pressure. In the example shown in fig. 11, the 2 nd pressure gauge 31 is provided in the cathode discharge path 24 upstream of the cathode valve 20B.

Fig. 12 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 4. The operation shown in fig. 12 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

Here, the contents of step S1, step S31, step S4, step S6, and step S16 in fig. 12 are the same as those of step S1, step S31, step S4, step S6, and step S16 in fig. 10, and thus detailed description thereof is omitted. In addition, at the start of the stop control of the hydrogen system 200, the cathode valve 20B is in a closed state, and the anode outlet valve 23 is in a closed state. In addition, the operation of the gas supplier 20A is stopped. The anode inlet valve 27 may be opened or closed, and the case where the anode inlet valve 27 is in an open state will be described in this example.

In step S1, the cathode valve 20B is opened, and in step S21, it is determined whether or not the cathode pressure is equal to or lower than a predetermined value a. The "predetermined value a" in step S21 is, for example, about 0.01MPa to 0.1MPa, but is not limited thereto.

Here, when the cathode pressure exceeds the predetermined value a (no in step S21), the state in which the cathode valve 20B is opened is maintained. If the cathode pressure reaches the predetermined value a or less (yes in step S21), the process proceeds to the next step S31, and the cathode valve 20B is closed in step S31.

In step S4, the gas supply device 20A is put into operation, and in step S51, it is determined whether or not the pressure difference "anode pressure-cathode pressure" between the anode pressure and the cathode pressure reaches a predetermined value B. The "predetermined value B" in step S51 is, for example, an arbitrary gauge pressure of about 0.01MPa to 1MPa, but is not limited thereto.

Here, when the pressure difference "anode pressure-cathode pressure" does not reach the predetermined value B (no in step S51), the gas supplier 20A is kept in operation. When the pressure difference "anode pressure-cathode pressure" reaches the predetermined value B (yes in step S51), the process proceeds to the next step S6, and the operation of the gas supplier 20A is stopped in step S6.

As described above, in the hydrogen system 200 according to the present embodiment, the timing of closing the cathode valve 20B can be appropriately known based on the cathode pressure measured by the 1 st pressure gauge 30. The hydrogen system 200 of the present embodiment can appropriately know the timing of stopping the operation of the gas supply unit 20A based on the pressure difference "anode pressure-cathode pressure" between the anode pressure and the cathode pressure measured by the 1 st pressure gauge 30 and the 2 nd pressure gauge 31.

In addition, in the hydrogen system 200 of the present embodiment, the anode pressure is set to be less than 1MPa according to the gauge pressure based on the atmospheric pressure, and thus the components connected to the anode AN in the hydrogen-containing gas supply system and the gas line of the anode AN can be easily configured in a low-pressure specification, compared with the case where the anode pressure is set to be 1MPa or more according to the gauge pressure, whereby the cost of the apparatus can be reduced.

The above predetermined values a and B are merely examples, and are not limited to this example. That is, in the hydrogen system 200 of the present embodiment, the predetermined value a and the predetermined value B may be set to arbitrary values as long as the condition that the anode pressure is higher than the cathode pressure is satisfied at the time of stopping the hydrogen system 200. For example, when the electrochemical hydrogen pump 100 is a compressor for a fuel cell forklift, a high-pressure cathode gas of about 40MPa is generally present on the cathode CA side. Therefore, the predetermined value a and the predetermined value B may not necessarily be set to values near the atmospheric pressure of less than 1 MPa.

The hydrogen system 200 of the present embodiment may be similar to any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, embodiment 1 to embodiment 5, and embodiment 2 modified examples and embodiment 3, except for the above-described features.

(embodiment 5)

In the example shown in fig. 13, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, a pressure regulator 20, an anode supply path 21, an anode discharge path 22, an anode outlet valve 23, an anode inlet valve 27, a cathode discharge path 24, a communication path 25, a 1 st pressure gauge 30, a 2 nd pressure gauge 31, and a controller 50. Here, the electrochemical hydrogen pump 100 is the same as in embodiment 1. The anode supply path 21, the anode discharge path 22, the anode outlet valve 23, the anode inlet valve 27, and the cathode discharge path 24 are the same as those of embodiment 3. The 1 st pressure gauge 30 and the 2 nd pressure gauge 31 are the same as those of embodiment 4.

The pressure regulator 20 includes a gas supply 20A, a cathode valve 20B, and a communication valve 20C. Here, the gas supplier 20A is the same as in example 3 of embodiment 1. The cathode valve 20B is the same as in example 3 of embodiment 2. In the following example, the case where the hydrogen-containing gas is supplied to the anode AN by the gas supplier 20A will be described, but the present invention is not limited thereto.

The communication valve 20C is a valve for supplying cathode gas from the cathode CA to the anode AN. The communication valve 20C may have any structure as long as it can supply the cathode gas from the cathode CA to the anode AN. As the communication valve 20C, for example, a drive valve or a solenoid valve driven by nitrogen gas, air, or the like can be used, but the present invention is not limited thereto. In addition, the communication valve 20C corresponds to one example of the "2 nd valve" of the present disclosure.

The communication valve 20C is provided in the communication path 25. In the case where the electrochemical hydrogen pump 100 includes the above-described cell group, the upstream end of the communication path 25 may be in communication with, for example, a manifold for cathode gas discharge. The downstream end of the communication path 25 may be in communication with a manifold for introducing a hydrogen-containing gas, for example. In the example shown in fig. 13, the downstream end of the communication path 25 is connected to the anode supply path 21 downstream of the gas supply device 20A, and the upstream end of the communication path 25 is connected to the cathode discharge path 24 upstream of the cathode valve 20B.

In the present embodiment, after the cathode pressure is reduced by opening the communication valve 20C, the controller 50 controls the gas supply unit 20A to supply the hydrogen-containing gas to the inlet of the anode AN in a state where the outlet of the anode AN is sealed, thereby increasing the anode pressure.

In the present embodiment, when the cathode gas is supplied from the cathode CA to the anode AN, the "state in which the inlet and outlet of the anode AN are sealed" is achieved, and the "state in which the hydrogen-containing gas flows out from the anode AN is sealed". In the example shown in fig. 13, when the communication valve 20C is opened, if the anode inlet valve 27 provided in the anode supply path 21 communicating with the inlet of the anode AN and the anode outlet valve 23 provided in the anode discharge path 22 communicating with the outlet of the anode AN are closed, the inlet and the outlet of the anode AN can be brought into a "sealed state".

In the present embodiment, when the gas is supplied to the inlet of the anode AN, the "state in which the outlet of the anode AN is sealed" is achieved, and the "state in which the hydrogen-containing gas flows out from the anode AN" is achieved. In the example shown in fig. 13, when the gas supply device 20A is controlled to supply gas to the inlet of the anode AN, if the anode outlet valve 23 provided in the anode discharge path 22 communicating with the outlet of the anode AN is closed, the outlet of the anode AN can be "sealed".

Fig. 14 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 5. The operation shown in fig. 14 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

Here, the contents of step S1, step S21, and step S31 in fig. 14 are the same as those of step S1, step S21, and step S31 in fig. 12, and thus detailed description thereof is omitted. Although not shown, the operations of step S1, step S21 and step S31 in fig. 14 are preliminary operations of opening and closing the cathode valve 20B for a predetermined time before the communication valve 20C in step S8 is opened. This is because if the communication valve 20C is opened without performing the preliminary operation described above when the cathode gas having a high pressure is present on the cathode CA side, the high-pressure cathode gas may be supplied to the hydrogen-containing gas supply system of the low-pressure specification. This preliminary operation is thus sometimes not required depending on the pressure of the cathode gas present at the cathode CA at the start of the stop control of the hydrogen system 200.

When the stop control of the hydrogen system 200 is started, the supply of the cathode gas from the cathode CA of the electrochemical hydrogen pump 100 to the hydrogen demand body (not shown) is stopped. At this time, the cathode valve 20B and the communication valve 20C are in a closed state, and the anode outlet valve 23 is in a closed state. In addition, the operation of the gas supplier 20A is stopped. The anode inlet valve 27 may be opened or closed, and the case where the anode inlet valve 27 is in an open state will be described in this example.

Here, the cathode valve 20B is closed in step S31, and the communication valve 20C is opened in step S8. In addition, the anode outlet valve 23 may be opened before step S8. In a state where the anode outlet valve 23 is opened, if the communication valve 20C is opened in step S8, the gas present on the anode AN is purged with the cathode gas.

Then, after "predetermined time D" has elapsed since the communication valve 20C was opened in step S9, the communication valve 20C is closed in step S10. As a result, the cathode CA supplies the cathode gas at a high pressure to the anode AN, and as a result, the anode pressure can be controlled to be approximately the same as the cathode pressure. The "predetermined time D" in step S9 is, for example, any time from about 60 seconds to about 30 minutes, but is not limited thereto. At this time, as the "predetermined time D" of step S9, a time measured by a timer of the controller 50 may be employed.

Then, the operation of the gas supplier 20A is started in step S4. At this time, although not shown, when the anode outlet valve 23 is in an open state at the time of opening the communication valve 20C, the anode outlet valve 23 is closed.

Here, when the pressure difference "anode pressure-cathode pressure" does not reach the predetermined value B (no in step S51), the gas supplier 20A is kept in operation. In the case where the above-described pressure difference "anode pressure-cathode pressure" reaches the predetermined value B (in the case of yes in step S51), the process proceeds to the next step S6, the operation of the gas supplier 20A is stopped in step S6, and the anode inlet valve 27 is closed in step S16.

As described above, in the hydrogen system according to the present embodiment, the anode pressure can be appropriately increased by using the supply pressure of the hydrogen-containing gas supplied to the anode AN in a state where the outlet of the anode AN is sealed. In the hydrogen system 200 of the present embodiment, the cathode pressure can be reduced so that the cathode pressure approaches the anode pressure by opening the communication valve 20C.

Here, the communication valve 20C functions as a valve for controlling the supply of the cathode gas from the cathode CA to the anode AN. As a result, in the hydrogen system 200 of the present embodiment, the cathode gas is supplied from the cathode CA to the anode AN by using the communication valve 20C, and the supply amount of the hydrogen-containing gas supplied from the gas supplier 20A to the anode AN is reduced in order to raise the pressure of the cathode CA, as compared with the case where the cathode gas is not supplied.

The hydrogen system 200 of the present embodiment may be similar to any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, embodiment 1 to embodiment 5, embodiment 2, embodiment 3, and embodiment 4, except for the above-described features.

(modification)

The hydrogen system 200 of the present modification is the same as that of embodiment 5 except for the control content of the controller 50 described below.

In a state where the outlet of the anode AN is sealed, the controller 50 increases the anode pressure by opening the communication valve 20C, and then decreases the cathode pressure by opening the cathode valve 20B.

Here, in the present modification, when the cathode gas is supplied from the cathode CA to the anode AN, the "state in which the inlet and outlet of the anode AN are sealed" is achieved, and the "state in which the hydrogen-containing gas flows out from the anode AN is sealed". In the example shown in fig. 13, when the communication valve 20C is opened, if the anode inlet valve 27 provided in the anode supply path 21 communicating with the inlet of the anode AN and the anode outlet valve 23 provided in the anode discharge path 22 communicating with the outlet of the anode AN are closed, the inlet and the outlet of the anode AN can be brought into a "sealed state".

Fig. 15 is a flowchart showing an example of the operation of the hydrogen system according to the modification of embodiment 5. The operation shown in fig. 15 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

In embodiment 5, as shown in fig. 14, after the communication valve 20C is closed in step S10, the operations of step S4, step S51, and step S6 are performed, but in the present modification, the following operations are performed instead of these operations.

In step S201, the cathode valve 20B is placed in an open state, and in step S51, it is determined whether or not the pressure difference "anode pressure-cathode pressure" between the anode pressure and the cathode pressure reaches a predetermined value B. The "predetermined value B" in step S51 is, for example, an arbitrary gauge pressure of about 0.01MPa to 1MPa, but is not limited thereto.

Here, when the pressure difference "anode pressure-cathode pressure" does not reach the predetermined value B (no in step S51), the state in which the cathode valve 20B is opened is maintained. When the pressure difference "anode pressure-cathode pressure" reaches the predetermined value B (yes in step S51), the process advances to step S203, and the cathode valve 20B is closed in step S203.

As described above, in the hydrogen system 200 according to the present modification example, the pressure of the anode AN is appropriately increased by the pressure of the cathode gas in a state where the outlet of the anode AN is sealed by opening the communication valve 20C, and then the pressure of the cathode CA is further reduced by opening the cathode valve 20B, whereby the pressure of the anode AN is made higher than the pressure of the cathode CA.

The hydrogen system 200 of the present modification example may be similar to any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, embodiment 1 to embodiment 5, embodiment 2 modification example, embodiment 3, embodiment 4, and embodiment 5, except for the above-described features.

(embodiment 6)

In the example shown in fig. 16, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, an anode supply path 21, an anode discharge path 22, an anode outlet valve 23, a cathode discharge path 24, an inflation valve 20AB, a gas supply path 26, a gas reservoir 40, a 1 st pressure gauge 30, a 2 nd pressure gauge 31, and a controller 50. Here, the electrochemical hydrogen pump 100 is the same as in embodiment 1. The anode supply path 21, the anode discharge path 22, the anode outlet valve 23, and the cathode discharge path 24 are the same as those of embodiment 3. The 1 st pressure gauge 30 and the 2 nd pressure gauge 31 are the same as those of embodiment 4.

The pressure regulator 20 includes a gas supply 20AA, an inflation valve 20AB, and a cathode valve 20B. Here, the cathode valve 20B is the same as in example 3 of embodiment 2.

The gas supplier 20AA supplies a gas different from the hydrogen-containing gas to the anode AN. The gas supplier 20AA may have any structure as long as it can supply a gas different from the hydrogen-containing gas to the anode AN. The gas supplier 20AA includes, for example, a pump. Examples of the gas other than the hydrogen-containing gas include nitrogen, helium, neon, argon, krypton, xenon, air, city gas, and liquefied petroleum gas.

The gas charging valve 20AB is provided in the gas supply path 26, and is a valve for supplying the gas from the gas reservoir 40 to the anode AN. The inflation valve 20AB and the gas supply path 26 may have any structures as long as the gas can be supplied from the gas reservoir 40 to the anode AN. In the example shown in fig. 16, the upstream end of the gas supply path 26 is connected to the gas reservoir 40, and the downstream end of the gas supply path 26 is connected to the gas supplier 20AA, but the present invention is not limited thereto. For example, when the gas pressure in the gas reservoir 40 is high, the downstream end of the gas supply path 26 may be connected to the anode supply path 21 upstream of the 1 st pressure gauge 30. As the inflation valve 20AB, for example, a drive valve or a solenoid valve driven by nitrogen gas, air, or the like can be used, but the present invention is not limited thereto.

Fig. 17 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 6. The operation shown in fig. 17 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

Here, the contents of step S1, step S21, and step S31 in fig. 17 are the same as those of step S1, step S21, and step S31 in fig. 12, and thus detailed description thereof is omitted. In addition, at the start of the stop control of the hydrogen system 200, the cathode valve 20B and the charging valve 20AB are in a closed state, and the anode outlet valve 23 is in a closed state. In addition, the operation of the gas supplier 20AA is stopped.

The cathode valve 20B is closed in step S31, and the inflation valve 20AB is opened in step S11. In addition, the gas supplier 20AA operates in step S204. Then, the supply of gas from the gas reservoir 40 to the anode AN is started. Thus, by supplying a gas different from the hydrogen-containing gas to the anode AN, the anode pressure is raised.

In step S204, the gas supplier 20AA is put into operation, and in step S51, it is determined whether the pressure difference "anode pressure-cathode pressure" between the anode pressure and the cathode pressure reaches a predetermined value B. The "predetermined value B" in step S51 is, for example, an arbitrary gauge pressure of about 0.01MPa to 1MPa, but is not limited thereto.

Here, when the pressure difference "anode pressure-cathode pressure" does not reach the predetermined value B (no in step S51), the inflation valve 20AB is maintained in an opened state and the gas supply device 20AA is operated. In the case where the above-described pressure difference "anode pressure-cathode pressure" reaches the predetermined value B (in the case of yes in step S51), the operation of the gas supplier 20AA is stopped in step S206, and the inflation valve 20AB is closed in step S12, proceeding to the next step S206 and step S12. Then, the supply of gas from the gas reservoir 40 to the anode AN is stopped.

The operational effects of the hydrogen system 200 and the operation method of the hydrogen system 200 according to the present embodiment can be easily understood by referring to the operational effects of the hydrogen system 200 and the operation method of the hydrogen system 200 according to embodiment 1 to embodiment 4, and therefore, the description thereof will be omitted.

The hydrogen system 200 and the operation method of the hydrogen system 200 according to the present embodiment may be the same as any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, embodiment 1 to embodiment 5 of embodiment 2, modification of embodiment 2, embodiment 3, embodiment 4, embodiment 5, and modification of embodiment 5, except for the above-described features.

(embodiment 7)

In the example shown in fig. 18, the hydrogen system 200 of the present embodiment includes an electrochemical hydrogen pump 100, a pressure regulator 20, an anode outlet valve 23, an anode inlet valve 27, and a controller 50. Here, the electrochemical hydrogen pump 100 is the same as in embodiment 1. The anode outlet valve 23 and the anode inlet valve 27 are the same as those of embodiment 3.

The pressure regulator 20 is a device including a voltage applicator 20D. The voltage applicator 20D is a device that applies a voltage between the anode AN and the cathode CA. The voltage applicator 20D may have any configuration as long as it can apply a voltage between the anode AN and the cathode CA. Thereby, current is conducted between anode AN and cathode CA by voltage applicator 20D. The voltage applicator 20D may be, for example, a DC/DC converter or an AC/DC converter. The DC/DC converter is used when the voltage applicator 20D is connected to a direct current power source such as a solar cell, a fuel cell, or a battery. The AC/DC converter is used when the voltage applicator 20D is connected to an AC power source such as a commercial power source.

The voltage applicator 20D may be, for example, a power-type power source that adjusts the voltage applied between the anode AN and the cathode CA and the current flowing between the anode AN and the cathode CA so that the power supplied to the unit of the electrochemical hydrogen pump 100 becomes a predetermined set value.

In the present embodiment, at the time of stopping the hydrogen system 200, the controller 50 controls the voltage applicator 20D to apply a voltage opposite to that before stopping the hydrogen system 200 between the anode AN and the cathode CA in a state where the inlet and the outlet of the anode AN are sealed, thereby increasing the anode pressure and decreasing the cathode pressure. Specifically, before the hydrogen system 200 is stopped, the high potential of the voltage applicator 20D is applied to the anode AN, while the low potential of the voltage applicator 20D is applied to the cathode CA, whereas during the stop of the hydrogen system 200, the high potential of the voltage applicator 20D is applied to the cathode CA, and the low potential of the voltage applicator 20D is applied to the anode AN.

In this embodiment, when a voltage opposite to that before the hydrogen system 200 is stopped is applied between the anode AN and the cathode CA, the "state in which the inlet and the outlet of the anode AN are sealed" is achieved, and the "state in which the hydrogen-containing gas flows out from the anode AN is sealed". For example, when the anode inlet valve 27 provided in the anode supply path communicating with the inlet of the anode AN and the anode outlet valve 23 provided in the anode discharge path communicating with the outlet of the anode AN are closed, the inlet and the outlet of the anode AN may be sealed.

Fig. 19 is a flowchart showing an example of the operation of the hydrogen system according to embodiment 7. The operation shown in fig. 19 can be performed by, for example, the arithmetic circuit of the controller 50 reading a control program from the memory circuit of the controller 50. But this is not necessarily done by the controller 50. Part of the work may be performed by the operator. In the following example, a case where the controller 50 controls the operation will be described.

Here, the contents of step S1 and step S21 in fig. 19 are the same as those of step S1 and step S21 in fig. 12, and thus detailed description thereof is omitted. When the stop control of the hydrogen system 200 is started, the cathode valve 20B (see fig. 4) and the anode outlet valve 23 are closed. The anode inlet valve 27 may be opened or closed, and the case where the anode inlet valve 27 is in an open state will be described in this example. In addition, the operation of the voltage applicator 20D is stopped.

In step S31A, the cathode valve 20B is closed, and the anode inlet valve 27 is closed. In this state, in step S13, the voltage applicator 20D is operated, and a voltage opposite to that before the hydrogen system 200 is stopped is applied between the anode AN and the cathode CA. Thus, at the time of stopping the hydrogen system 200, protons move from the cathode CA to the anode AN via the electrolyte membrane 10.

In step S13, the voltage applicator 20D is put into operation, and in step S51, it is determined whether the pressure difference "anode pressure-cathode pressure" between the anode pressure and the cathode pressure reaches a predetermined value B. The "predetermined value B" in step S51 is, for example, an arbitrary gauge pressure of about 0.01MPa to 1MPa, but is not limited thereto.

Here, when the pressure difference "anode pressure-cathode pressure" does not reach the predetermined value B (no in step S51), the voltage applicator 20D is maintained in an operating state. In the case where the above-described pressure difference "anode pressure-cathode pressure" reaches the predetermined value B (in the case of yes in step S51), the process proceeds to the next step S14, and the operation of the voltage applicator 20D is stopped in step S14.

As described above, in the hydrogen system 200 according to the present embodiment, when the hydrogen system 200 is stopped, the anode pressure is raised and the cathode pressure can be reduced by applying the voltage opposite to that before the hydrogen system 200 is stopped between the anode AN and the cathode CA in a state where the inlet and the outlet of the anode AN are sealed, and thereby moving protons from the cathode CA to the anode AN via the electrolyte membrane 10.

The hydrogen system 200 of the present embodiment may be similar to any of embodiment 1, embodiment 1 to embodiment 3, embodiment 2, embodiment 1 to embodiment 5, embodiment 2 modification, embodiment 3, embodiment 4, embodiment 5 modification, and embodiment 6, except for the above-described features.

Embodiment 1, embodiment 1 to embodiment 3, embodiment 2, embodiment 1 to embodiment 5 of embodiment 2, and modified examples of embodiment 2, embodiment 3, embodiment 4, embodiment 5, modified examples of embodiment 5, embodiment 6, and embodiment 7 may be combined with each other as long as they are not mutually exclusive.

In addition, many modifications and other embodiments of the disclosure will be apparent to those skilled in the art in light of the above description. Accordingly, the foregoing description should be construed as illustrative only and is presented to teach those skilled in the art the best way to practice the present disclosure. The details of the structure and/or function may be substantially changed without departing from the spirit of the present disclosure.

Industrial applicability

The technical scheme of the present disclosure can be applied to a hydrogen system and an operation method of the hydrogen system, which can suppress a decrease in efficiency of a hydrogen compression operation at the time of restarting, compared with the prior art.

Description of the reference numerals

10: electrolyte membrane

20: pressure regulator

20A: gas supply device

20AA: gas supply device

20AB: inflation valve

20B: cathode valve

20C: communication valve

20D: voltage applicator

21: anode supply path

22: anode discharge path

23: anode outlet valve

24: cathode discharge path

25: communication path

26: gas supply path

27: anode inlet valve

30: 1 st pressure gauge

31: 2 nd pressure gauge

40: gas storage device

50: controller for controlling a power supply

100: electrochemical hydrogen pump

200: hydrogen system

AN: anode

CA: cathode electrode

Claims

1. A hydrogen system includes a compressor, a pressure regulator, and a controller,

applying a voltage between an anode and a cathode provided so as to sandwich an electrolyte membrane, moving hydrogen in a hydrogen-containing gas supplied to the anode to the cathode, generating compressed hydrogen by the compressor,

the pressure regulator regulates at least the pressure of the anode,

when the hydrogen system is stopped, the controller controls the pressure regulator so that the pressure of the anode is higher than the pressure of the cathode in a state where the hydrogen-containing gas is blocked from flowing out of the anode.

2. The hydrogen system according to claim 1,

the controller controls the pressure regulator to raise the pressure of the anode, thereby making the pressure of the anode higher than the pressure of the cathode.

3. The hydrogen system according to claim 2,

After the controller controls the pressure regulator to raise the pressure of the anode, when the pressure difference between the anode and the cathode is reduced, the controller controls the pressure regulator to raise the pressure of the anode.

4. The hydrogen system according to claim 1 to 3,

the pressure regulator includes a gas supplier that supplies gas to the anode,

the controller controls the gas supplier to supply gas to the anode in a state where an outlet of the anode is sealed, thereby increasing a pressure of the anode.

5. The hydrogen system according to claim 1,

the pressure regulator regulates the pressures of the anode and the cathode, and the controller controls the pressure regulator to raise the pressure of the anode and to reduce the pressure of the cathode, thereby making the pressure of the anode higher than the pressure of the cathode.

6. The hydrogen system according to claim 5,

after the controller controls the pressure regulator to raise the pressure of the anode and to reduce the pressure of the cathode, the controller controls the pressure regulator to raise the pressure of the anode when the pressure difference between the anode and the cathode is reduced.

7. The hydrogen system according to claim 5,

after the controller controls the pressure regulator to raise the pressure of the anode and to reduce the pressure of the cathode, the controller controls the pressure regulator to reduce the pressure of the cathode when the pressure difference between the anode and the cathode is reduced.

8. The hydrogen system according to claim 5 to 7,

the pressure regulator includes a gas supply unit for supplying a gas to the anode, and a 1 st valve for discharging a cathode gas containing compressed hydrogen from the cathode to a different portion from the anode,

in a state where an outlet of the anode is sealed, the controller increases the pressure of the anode by controlling the gas supplier to supply gas to the anode, and decreases the pressure of the cathode by opening the 1 st valve.

9. The hydrogen system according to claim 5 or 6,

the pressure regulator includes a gas supplier for supplying a gas to the anode, and a 2 nd valve for supplying a cathode gas containing compressed hydrogen from the cathode to the anode,

the controller increases the pressure of the anode by controlling the gas supplier to supply gas to the anode in a state where the outlet of the anode is sealed after the pressure of the cathode is reduced by opening the 2 nd valve.

10. The hydrogen system according to claim 5 or 7,

the pressure regulator includes a 2 nd valve for supplying a cathode gas containing compressed hydrogen from the cathode to the anode, and a 1 st valve for discharging the cathode gas to a different location from the anode,

the controller may reduce the pressure of the cathode by opening the 1 st valve after lifting the pressure of the anode by opening the 2 nd valve in a state where the outlet of the anode is sealed.

11. The hydrogen system according to any one of claims 4, 8 to 10, comprising a discharge path and a 3 rd valve,

the hydrogen-containing gas discharged from the anode flows in the discharge path,

the 3 rd valve is disposed in the discharge path,

the controller seals the outlet of the anode by closing the 3 rd valve.

12. The hydrogen system according to claim 1 to 3, 5 to 7,

the controller controls the pressure regulator so that the pressure of the anode is less than 1MPa.

13. The hydrogen system according to claim 4, 8 to 10,

the gas supplier supplies a gas different from the hydrogen-containing gas.

14. The hydrogen system according to claim 5 to 7,

The pressure regulator includes a voltage applicator for applying a voltage between the anode and the cathode, and the controller controls the voltage applicator in a state where an inlet and an outlet of the anode are sealed, and applies a voltage opposite to that before stopping between the anode and the cathode, thereby increasing the pressure of the anode and decreasing the pressure of the cathode.

15. A method for operating a hydrogen system is provided with:

a step of generating compressed hydrogen by applying a voltage between an anode and a cathode provided so as to sandwich an electrolyte membrane, and moving hydrogen in a hydrogen-containing gas supplied to the anode to the cathode; and

and stopping the hydrogen system, wherein the pressure of the anode is higher than the pressure of the cathode in a state of sealing off the hydrogen-containing gas flowing out from the anode.

16. The method for operating a hydrogen system according to claim 15,

the pressure of the anode is made higher than the pressure of the cathode by raising the pressure of the anode.

17. The method for operating a hydrogen system according to claim 15,

the pressure of the anode is made higher than the pressure of the cathode by raising the pressure of the anode and reducing the pressure of the cathode.

18. The method for operating a hydrogen system according to claim 16 or 17,

the pressure of the anode is raised by supplying gas to the anode.

19. The method for operating a hydrogen system according to claim 17,

the pressure of the cathode is reduced by exhausting a cathode gas containing the compressed hydrogen from the cathode.

20. The method of operating a hydrogen system according to claim 18,

the pressure of the anode is raised by supplying a gas other than the hydrogen-containing gas to the anode.