Hydrogen system

Abstract

A hydrogen system comprises a compressor, an anode gas supply path, a recovery flow path, a drainage path, a pump and a controller. The compressor applies a voltage between an anode and a cathode arranged to clamp an electrolyte membrane to move hydrogen in the hydrogen-containing gas supplied to the anode to the cathode to generate compressed hydrogen. The anode gas supply path is used to flow the hydrogen-containing gas supplied to the anode. The recovery flow path is used to flow the anode exhaust gas that is discharged from the anode and is about to merge with the anode gas supply path. The drainage path is provided in the recovery flow path, or in the anode gas supply path downstream of the location where the anode gas supply path merges with the recovery flow path, and is used to discharge liquid water to the outside of the recovery flow path or the outside of the anode gas supply path. The pump is provided in the recovery flow path, or in the anode gas supply path downstream of the location where the anode gas supply path merges with the recovery flow path. When the operation of the compressor is stopped, the controller operates the pump in a state where the applied voltage is reduced.

Description

Technical Field

[0001] The present disclosure relates to hydrogen systems. Background Art

[0002] In recent years, due to environmental issues such as global warming and energy issues such as the depletion of oil resources, hydrogen has attracted attention as a clean alternative energy source to replace fossil fuels. Even if hydrogen is burned, it basically only produces water, does not emit carbon dioxide, which is the cause of global warming, and basically does not emit nitrogen oxides, etc., so it is expected to be used as a clean energy source. In addition, as a device that efficiently uses hydrogen as a fuel, there are fuel cells, and the development and popularization of them for automotive power sources and household private power generation are constantly advancing.

[0003] In the upcoming hydrogen society, in addition to hydrogen production, it is also required to develop technologies that can store hydrogen at high density and transport or utilize hydrogen in a small volume and at low cost. In particular, to promote the popularization of fuel cells as a distributed energy source, it is necessary to equip hydrogen supply facilities. In addition, in order to stably supply hydrogen, various studies are being conducted on the production, purification, and high-density storage of high-purity hydrogen.

[0004] For example, Patent Document 1 records that the hydrogen-containing gas can be purified and boosted by applying a voltage between the anode and cathode of the hydrogen purification boosting system. Specifically, by applying a voltage between the anode and the cathode, the hydrogen in the hydrogen-containing gas becomes protons at the anode. The protons move from the anode to the cathode in the electrolyte membrane along with water molecules and are restored to hydrogen at the cathode. Furthermore, the stacked structure of the anode, electrolyte membrane and cathode is called a membrane electrode assembly (hereinafter referred to as MEA: Membrane Electrode Assembly). Furthermore, Patent Document 1 records that when the hydrogen purification boosting system stops, the gas remaining in the cathode of the system is purified with nitrogen.

[0005] Prior art literature

[0006] Patent Document 1: Japanese Patent No. 6299027 Summary of the invention

[0007] An object of the present disclosure is to provide, as an example, a hydrogen system capable of suppressing a decrease in efficiency of a hydrogen compression operation at the time of restart more than conventional systems.

[0008] The present disclosure discloses a hydrogen system in one aspect, comprising a compressor, an anode gas supply path, a recovery flow path, a drainage path, a pump, and a controller, wherein the compressor applies a voltage between an anode and a cathode arranged with an electrolyte membrane interposed therebetween to move hydrogen in a hydrogen-containing gas supplied to the anode to the cathode to generate compressed hydrogen, the anode gas supply path being used to flow the hydrogen-containing gas supplied to the anode, the recovery flow path being used to flow the anode exhaust gas discharged from the anode and to be merged with the anode gas supply path, the drainage path being provided on the recovery flow path or on the anode gas supply path downstream of a portion where the anode gas supply path merges with the recovery flow path, and being used to discharge liquid water to the outside of the recovery flow path or the outside of the anode gas supply path, the pump being provided on the recovery flow path or on the anode gas supply path downstream of a portion where the anode gas supply path merges with the recovery flow path, and when the operation of the compressor is stopped, the controller operates the pump in a state where the voltage applied to the compressor is reduced.

[0009] The hydrogen system according to one aspect of the present disclosure can achieve an effect of suppressing a decrease in efficiency of the hydrogen compression operation at the time of restarting more than conventional systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a diagram showing an example of the electrochemical hydrogen pump according to the first embodiment.

[0011] Figure 2A This is a diagram showing an example of the electrochemical hydrogen pump according to the first embodiment.

[0012] Figure 2B This is a diagram showing an example of the electrochemical hydrogen pump according to the first embodiment.

[0013] Figure 2C This is a diagram showing an example of the electrochemical hydrogen pump according to the first embodiment.

[0014] Figure 2D This is a diagram showing an example of the electrochemical hydrogen pump according to the first embodiment.

[0015] Figure 3 This is a diagram showing an example of a hydrogen system according to a modification of the first embodiment.

[0016] Figure 4 This is a diagram showing an example of a hydrogen system according to the second embodiment.

[0017] Figure 5 This is a diagram showing an example of a hydrogen system according to the third embodiment.

[0018] Figure 6 This is a diagram showing an example of a hydrogen system according to a fourth embodiment.

[0019] Figure 7 This is a diagram showing an example of a hydrogen system according to the fifth embodiment.

[0020] Figure 8 This is a flowchart showing an example of the operation of the hydrogen system according to the fifth embodiment.

[0021] Fig. 9 This is a flowchart showing an example of the operation of the hydrogen system according to the modification of the fifth embodiment. DETAILED DESCRIPTION

[0022] In an electrochemical compressor, the electrolyte membrane generally exhibits the expected proton conductivity in a wet state. Therefore, in order to maintain the efficiency of the hydrogen compression operation of the compressor at the expected value, the electrolyte membrane needs to be kept in a wet state. Therefore, a high-humidity hydrogen-containing gas has been supplied to the anode of the compressor in most cases.

[0023] Here, in the hydrogen compression action of the compressor, a voltage is applied between the anode and cathode of the MEA (component). Therefore, in this case, by flowing current between the anode and the cathode, protons move from the anode to the cathode in the electrolyte membrane along with water (electro-osmosis). On the other hand, the electro-osmotic water moving from the anode to the cathode moves from the cathode to the anode (reverse diffusion) due to the pressure difference between the cathode and the anode. Furthermore, at this time, the higher the gas pressure on the cathode side, the more water moves from the cathode to the anode. In the hydrogen compression action of the compressor, even if water diffuses back from the cathode to the anode, the hydrogen-containing gas will circulate on the anode, so the water will not be retained and the overflow will be suppressed. However, when the compressor is stopped, if the voltage between the anode and the cathode is reduced and the circulation of the hydrogen-containing gas on the anode is stopped, the reverse diffusion of water continues during the period before the pressure difference between the anode and the cathode disappears, and the water from the reverse diffusion is retained on the anode. As a result, after the compressor stops, the possibility of overflow (blockage caused by water in the gas flow path) at the anode increases. If flooding occurs, the diffusion of hydrogen-containing gas on the anode of the compressor is hindered when restarting, so the voltage of the voltage applicator required to ensure that a predetermined amount of protons move to the cathode may increase. As a result, the efficiency of the hydrogen compression action decreases when the compressor restarts.

[0024] Therefore, the hydrogen system of the first embodiment of the present invention comprises a compressor, an anode gas supply path, a recovery flow path, a drainage path, a pump and a controller. The compressor moves hydrogen in the hydrogen-containing gas supplied to the anode to the cathode by applying a voltage between an anode and a cathode arranged to clamp an electrolyte membrane, thereby generating compressed hydrogen. The anode gas supply path is used to flow the hydrogen-containing gas supplied to the anode. The recovery flow path is used to flow the anode exhaust gas that is discharged from the anode and is about to merge with the anode gas supply path. The drainage path is provided in the recovery flow path, or in the anode gas supply path downstream of the point where the anode gas supply path merges with the recovery flow path, and is used to discharge liquid water to the outside of the recovery flow path or the outside of the anode gas supply path. The pump is provided in the recovery flow path, or in the anode gas supply path downstream of the point where the anode gas supply path merges with the recovery flow path. When the operation of the compressor is stopped, the controller operates the pump in a state where the voltage applied by the compressor is reduced.

[0025] According to this technical configuration, the hydrogen system of this embodiment can suppress the decrease in efficiency of the hydrogen compression operation at the time of restarting more than ever before.

[0026] Specifically, the hydrogen system of this method operates the pump in a state where the voltage is reduced when the compressor stops, so that the anode exhaust gas circulates in the recovery flow path, the anode gas supply path downstream of the location where the anode gas supply path and the recovery flow path merge, and the gas flow path on the anode in the compressor (hereinafter referred to as the circulation path). As a result, after the voltage drops, the water that diffuses back from the cathode to the anode does not remain on the anode, and the liquid water in the hydrogen-containing gas circulating in the circulation path containing the back-diffused water is discharged through the drainage path. Therefore, since the hydrogen system of this method is unlikely to overflow at the anode after the operation of the compressor stops, the reduction in the efficiency of the hydrogen compression action at the time of restarting can be suppressed.

[0027] The hydrogen system of the second embodiment of the present disclosure may be a hydrogen system of the first embodiment, wherein a gas-liquid separator is provided on the recovery flow path or on the anode gas supply path downstream of the location where the anode gas supply path and the recovery flow path merge, and the drainage path is connected to the water storage portion of the gas-liquid separator.

[0028] According to this technical configuration, the hydrogen system of this embodiment promotes the separation of liquid water in the hydrogen-containing gas circulating in the circulation path from the hydrogen-containing gas by the gas-liquid separator, thereby appropriately discharging the liquid water in the hydrogen-containing gas through the drainage path.

[0029] The hydrogen system of the third embodiment of the present disclosure may be a hydrogen system of the first embodiment or the second embodiment, wherein a pump is provided on the anode gas supply path downstream of the point where the anode gas supply path merges with the recovery path, and a hydrogen purifier is provided for generating purified hydrogen by applying a voltage between an anode and a cathode arranged to clamp an electrolyte membrane, thereby causing hydrogen in the hydrogen-containing gas supplied to the anode to move to the cathode.

[0030] According to this technical configuration, the hydrogen system of this mode does not need to be equipped with a special circulation pump, etc., and can remove impurities in the hydrogen-containing gas by operating the hydrogen purifier while circulating the hydrogen-containing gas in the circulation path. As a result, it is possible to suppress the overflow of the anode of the compressor after the compressor stops operating. At this time, since the hydrogen-containing gas also flows in the hydrogen purifier, it is also possible to suppress the overflow of the hydrogen purifier.

[0031] However, during the stop period of the compressor operation, the compressor is naturally cooled and condensed water is generated from the highly humidified hydrogen-containing gas. Therefore, in order to suppress the occurrence of flooding, the circulation of the hydrogen-containing gas in the circulation path may be performed until the temperature in the compressor becomes equal to the ambient temperature and the generation of condensed water from the hydrogen-containing gas stops.

[0032] Therefore, the hydrogen system according to the fourth aspect of the present disclosure may include a cooler for cooling the compressor in the hydrogen system of any one of the first to third aspects, and the controller may operate the pump to cool the compressor by the cooler.

[0033] According to this technical configuration, when the operation of the compressor stops, the hydrogen system of this mode cools the compressor while circulating the hydrogen-containing gas in the circulation path, so that not only the water from the reverse diffusion but also the condensed water from the hydrogen-containing gas flowing on the anode can be effectively discharged through the drainage path. That is, compared with the case where the compressor is naturally cooled during the circulation of the hydrogen-containing gas, the hydrogen system of this mode can promote the removal of water (water vapor and liquid water) on the anode. As a result, the circulation time of the hydrogen-containing gas after the voltage is reduced for suppressing the overflow on the anode can be shortened.

[0034] The hydrogen system of the fifth embodiment of the present disclosure may include a condenser in the hydrogen system of any one of the first to fourth embodiments, wherein the condenser is provided in the recovery flow path or in the anode gas supply path downstream of the point where the anode gas supply path and the recovery flow path merge.

[0035] According to this technical configuration, when the compressor stops, the hydrogen system of this mode condenses water vapor in the hydrogen-containing gas by using a condenser when the hydrogen-containing gas in the circulation path circulates, so that not only the water from the reverse diffusion but also the condensed water from the hydrogen-containing gas is effectively discharged through the drainage path. That is, compared with the case where the compressor is naturally cooled during the circulation of the hydrogen-containing gas, the hydrogen system of this mode can promote the removal of moisture (water vapor and liquid water) on the anode. As a result, the circulation time of the hydrogen-containing gas after the voltage is reduced for suppressing the overflow on the anode can be shortened.

[0036] The hydrogen system of the sixth embodiment of the present disclosure may be provided with a flow regulator in the hydrogen system of any one of the first to fifth embodiments, and the flow regulator adjusts the flow of the hydrogen-containing gas in the anode gas supply path upstream of the confluence of the anode gas supply path and the recovery path. When the pump is working, the controller controls the flow regulator to gradually reduce the flow of the hydrogen-containing gas and the output power of the pump, and then stops the pump.

[0037] According to this technical configuration, when the compressor is stopped, the hydrogen system of this embodiment operates the pump so that the anode exhaust gas circulates in the circulation path, thereby injecting hydrogen-containing gas into the circulation path and appropriately discharging liquid water through the drainage path.

[0038] Specifically, in the hydrogen system of this method, when the compressor stops operating, when the pump is operated in a manner that the anode exhaust gas circulates in the circulation path, the temperature of the compressor decreases over time, and thus the water vapor in the hydrogen-containing gas on the anode condenses. As a result, the pressure decreases as the molar amount of gas molecules of the hydrogen-containing gas present in the circulation path decreases, and thus the circulation path may become negatively pressurized. As a result, due to the intrusion of air into the circulation path from the outside, the components of the compressor may be deteriorated.

[0039] Therefore, the hydrogen system of this method uses a flow regulator to inject hydrogen-containing gas into the circulation path from the anode gas supply path upstream of the point where the anode gas supply path merges with the recovery path to compensate for the pressure reduction of the hydrogen-containing gas in the above-mentioned circulation path, thereby suppressing the negative pressure in the circulation path.

[0040] In addition, it can be easily understood from the curve of the amount of saturated water vapor in the hydrogen-containing gas related to the temperature of the hydrogen-containing gas that the amount of water condensed from the water vapor in the hydrogen-containing gas decreases as the temperature of the hydrogen-containing gas decreases over time. Therefore, the hydrogen system of this embodiment can inject an appropriate amount of hydrogen-containing gas into the circulation path from the upstream side of the anode gas supply path by gradually reducing the flow rate of the hydrogen-containing gas and the pump output power over time.

[0041] In the hydrogen system of the seventh embodiment of the present disclosure, when an abnormality occurs in the hydrogen system of the sixth embodiment and causes the compressor to stop operating, thereby making it impossible to supply hydrogen-containing gas from the hydrogen-containing gas supply source, the controller can gradually reduce the output of the pump without controlling the flow regulator and then stop the pump.

[0042] According to this technical configuration, the hydrogen system of the present embodiment can appropriately perform system stop control when the hydrogen-containing gas cannot be supplied due to an abnormality in the supply source of the hydrogen-containing gas.

[0043] Hereinafter, with reference to the accompanying drawings, the embodiments of the present disclosure will be described. The embodiments described below all represent an example of each of the above-mentioned methods. Therefore, the numerical values, shapes, materials, constituent elements, and the configuration positions and connection forms of the constituent elements shown below are only examples, and the above-mentioned methods are not limited unless they are recorded in the claims. In addition, the constituent elements that are not recorded in the independent claims representing the highest concept of the present method among the following constituent elements are described as optional constituent elements. In addition, the description of the same mark in the drawings is sometimes omitted. For easy understanding, the drawings schematically show the respective constituent elements, and the shapes and size ratios are sometimes not accurately represented. In addition, during work, the order of each process can be changed as needed, and other known processes can be added.

[0044] (First embodiment)

[0045] In the following embodiment, the structure and operation of an electrochemical hydrogen pump as an example of the above-mentioned compression device will be described.

[0046] [Device structure]

[0047] Figure 1 This is a diagram showing an example of the electrochemical hydrogen pump according to the first embodiment.

[0048] Figure 1 In the example shown, the hydrogen system 200 of the present embodiment includes the electrochemical hydrogen pump 100. The electrochemical hydrogen pump 100 may include a stack in which a plurality of MEAs (modules) are stacked. Details will be described later.

[0049] The electrochemical hydrogen pump 100 includes an electrolyte membrane 20 , an anode AN, a cathode CA, and a voltage applicator 21 .

[0050] The anode AN is provided on one main surface of the electrolyte membrane 20. The anode AN is an electrode including an anode catalyst layer and an anode gas diffusion layer. The cathode CA is provided on the other main surface of the electrolyte membrane 20. The cathode CA is an electrode including a cathode catalyst layer and a cathode gas diffusion layer. Thus, the electrolyte membrane 20 is in contact with the anode catalyst layer and the cathode catalyst layer, respectively, and is sandwiched by the anode AN and the cathode CA.

[0051] As long as it is a membrane with proton conductivity, the electrolyte membrane 20 can be of various structures. For example, as the electrolyte membrane 20, a fluorine-based polymer electrolyte membrane, a hydrocarbon-based electrolyte membrane, etc. can be cited. Specifically, as the electrolyte membrane 20, for example, Nafion (registered trademark, manufactured by DuPont), Aciplex (registered trademark, manufactured by Asahi Kasei Corporation), etc. can be used, but it is not limited thereto.

[0052] The anode catalyst layer is provided on one main surface of the electrolyte membrane 20. The anode catalyst layer includes carbon capable of supporting a catalyst metal (for example, platinum) in a dispersed state, but is not limited thereto.

[0053] The cathode catalyst layer is provided on the other main surface of the electrolyte membrane 20. The cathode catalyst layer includes carbon capable of supporting a catalyst metal (for example, platinum) in a dispersed state, but is not limited thereto.

[0054] Various methods can be cited as the modulation method of the cathode catalyst layer and the anode catalyst layer as catalysts, and there is no particular limitation. For example, as carbon-based powders, powders such as graphite, carbon black, and activated carbon with conductivity can be cited. The method of supporting platinum or other catalytic metals on a carbon carrier is not particularly limited. For example, methods such as powder mixing or liquid phase mixing can be used. As the latter liquid phase mixing, for example, a method of dispersing and adsorbing a carrier such as carbon in a colloidal liquid of the catalyst component can be cited. The supporting state of catalyst metals such as platinum on the carbon carrier is not particularly limited. For example, the catalyst metal can be micronized and supported on the carrier with high dispersion.

[0055] The cathode gas diffusion layer is provided on the cathode catalyst layer. The cathode gas diffusion layer is made of a porous material and has electrical conductivity and gas diffusion properties. It is desirable that the cathode gas diffusion layer has elasticity to appropriately follow the displacement and deformation of the constituent members caused by the pressure difference between the cathode CA and the anode AN when the electrochemical hydrogen pump 100 is working. As a substrate for the cathode gas diffusion layer, for example, a carbon fiber sintered body can be used, but it is not limited thereto.

[0056] The anode gas diffusion layer is provided on the anode catalyst layer. The anode gas diffusion layer is composed of a porous material and has electrical conductivity and gas diffusion properties. It is desirable that the anode gas diffusion layer has a degree of rigidity that can withstand the pressure adhesion of the electrolyte membrane 20 caused by the above-mentioned pressure difference when the electrochemical hydrogen pump 100 is working. As a substrate for the anode gas diffusion layer, for example, a carbon particle sintered body can be used, but it is not limited thereto.

[0057] The voltage applicator 21 is a device that applies a voltage between the anode AN and the cathode CA that are arranged to sandwich the electrolyte membrane 20. The voltage applicator 21 may have various structures as long as it can apply a voltage between the anode AN and the cathode CA. Figure 1In the example shown, the high potential side terminal of the voltage applicator 21 is connected to the anode AN, and the low potential side terminal of the voltage applicator 21 is connected to the cathode CA. Thus, the voltage applicator 21 is used to pass electricity between the anode AN and the cathode CA. Therefore, in the electrochemical hydrogen pump 100 of the present embodiment, the voltage applicator 21 applies a voltage between the anode AN and the cathode CA, so that hydrogen in the hydrogen-containing gas supplied to the anode AN moves to the cathode CA, and compressed hydrogen is generated.

[0058] Furthermore, as the voltage applicator 21, for example, a DC / DC converter, an AC / DC converter, etc. can be cited. When the voltage applicator 21 is connected to a DC power source such as a solar cell, a fuel cell, or a battery, a DC / DC converter is used. When the voltage applicator 21 is connected to an AC power source such as a commercial power source, an AC / DC converter is used.

[0059] In addition, the voltage applicator 21 can be a power source, for example, adjusting 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 components of the electrochemical hydrogen pump 100 becomes a predetermined set value.

[0060] The hydrogen-containing gas may be, for example, hydrogen gas generated by electrolysis of water, or may be reformed gas generated by a reforming reaction of hydrocarbon gas.

[0061] Here, although Figure 1 Although not shown, components and equipment required for the hydrogen compression operation of the hydrogen system 200 may be appropriately provided.

[0062] For example, a pair of diaphragms may sandwich the anode AN and the cathode CA from the outside, respectively. In this case, the diaphragm in contact with the anode AN is a conductive plate-shaped member for supplying hydrogen-containing gas to the anode AN. The plate-shaped member has a serpentine gas flow path through which the hydrogen-containing gas supplied to the anode AN flows. The diaphragm in contact with the cathode CA is a conductive plate-shaped member for extracting hydrogen from the cathode CA. The plate-shaped member has a gas flow path through which the hydrogen extracted from the cathode CA flows.

[0063] In addition, in the electrochemical hydrogen pump 100, sealing materials such as gaskets are usually provided on both sides of the assembly to prevent high-pressure hydrogen from leaking to the outside, and are pre-assembled as an integrated part of the assembly of the electrochemical hydrogen pump 100. Furthermore, the above-mentioned diaphragm is arranged on the outside of the assembly for mechanically fixing it and electrically connecting adjacent assemblies in series.

[0064] The components and the diaphragms are alternately overlapped, and about 10 to 200 components are stacked. The stack (stack) is clamped by end plates with collector plates and insulating plates interposed therebetween, and the two end plates are fastened by tie rods. This is a general stacking structure. Furthermore, in this case, in order to supply an appropriate amount of hydrogen-containing gas to each gas flow path of the diaphragm, it is necessary to form a structure in which a groove-shaped branch path branches from an appropriate pipeline in each diaphragm, and their downstream ends are connected to each gas flow path of the diaphragm. Such a pipeline is called a manifold, and the manifold is composed of, for example, a connection of through holes provided at each appropriate position of the components constituting the stack.

[0065] Furthermore, the hydrogen system 200 may be provided with a temperature detector for detecting the component temperature, a temperature regulator for adjusting the component temperature, a dew point regulator for adjusting the dew point of the hydrogen-containing gas supplied to the anode AN, and the like.

[0066] It should be noted that the above-mentioned components and devices not shown in the figures are merely examples and are not limited to the present example.

[0067] like Figure 1 As shown, the hydrogen system 200 includes an anode gas supply path 1 , a recovery path 2 , a drain path 3 , a pump 5 , and a controller 50 .

[0068] The anode gas supply path 1 is a flow path for the hydrogen-containing gas supplied to the anode AN of the electrochemical hydrogen pump 100. When the electrochemical hydrogen pump 100 is equipped with the above-mentioned stack, the downstream end of the anode gas supply path 1 can be connected to a manifold for introducing hydrogen-containing gas, for example. In addition, the upstream end of the anode gas supply path 1 can be connected to a hydrogen-containing gas supply source (not shown), for example. Furthermore, as a supply source of hydrogen-containing gas, for example, a reformer, a water electrolysis device, a hydrogen tank, etc. can be cited.

[0069] The recovery flow path 2 is a flow path for the anode exhaust gas discharged from the anode AN of the electrochemical hydrogen pump 100 to flow and merge with the anode gas supply path 1. When the electrochemical hydrogen pump 100 has the above-mentioned stack, the upstream end of the recovery flow path 2 can be connected to a manifold for derivation of hydrogen-containing gas, for example.

[0070] Thus, in the hydrogen system 200 of this embodiment, Figure 1 As shown, a circulation path 4 for circulating the anode exhaust gas discharged from the anode AN is formed by a recovery path 2, an anode gas supply path 1 downstream of a portion 2A where the anode gas supply path 1 and the recovery path 2 merge, and a gas path (not shown) on the anode AN in the electrochemical hydrogen pump 100.

[0071] The drainage path 3 is provided in the recovery flow path 2, or in the anode gas supply path 1 downstream of the portion 2A where the anode gas supply path 1 and the recovery flow path 2 merge, and is a flow path for discharging liquid water to the outside of the recovery flow path 2 or the outside of the anode gas supply path 1. As long as it is a flow path where the anode exhaust gas discharged from the anode AN flows, the upstream end of the drainage path 3 can be connected to various locations. For example, Figure 2A In the example shown, the upstream end of the drainage path 3A is connected to the recovery flow path 2. In this case, liquid water in the anode off-gas is discharged from the drainage path 3A. Figure 2B In the example shown, the upstream end of the drainage path 3B is connected to the anode gas supply path 1 downstream of the portion 2A where the anode gas supply path 1 merges with the recovery flow path 2. In this case, liquid water in the hydrogen-containing gas supplied to the anode AN is discharged from the drainage path 3B, and the liquid water includes liquid water in the anode exhaust gas merged with the anode gas supply path 1.

[0072] Furthermore, an appropriate on-off valve (not shown) may be provided in the drainage path 3, and the end of the flow path extending from the on-off valve may be opened to the outside. Thus, condensed water in the drainage path 3 is promptly discharged to the outside by opening and closing the on-off valve.

[0073] The pump 5 is a device provided in the recovery flow path 2, or provided in the anode gas supply path 1 downstream of the location 2A where the anode gas supply path 1 and the recovery flow path 2 merge. In other words, the pump 5 is a device that circulates the anode exhaust gas discharged from the anode AN in the circulation path 4. The pump 5 can be provided in various locations as long as the flow path is a flow path in which the anode exhaust gas discharged from the anode AN flows. For example, Figure 2C In the example shown, the pump 5A is provided on the anode gas supply path 1 downstream of the portion 2A where the anode gas supply path 1 merges with the circulation flow path 2 . Figure 2D In the example shown, the pump 5B is provided on the recovery flow path 2 .

[0074] As long as such anode exhaust gas can be circulated in the circulation path 4, the pump 5 can be of various types. As the pump 5, for example, a constant volume type reciprocating pump, a rotary pump, etc. can be cited, but it is not limited to this. For example, the pump 5 can be an electrochemical hydrogen purifier (hydrogen pump). The details are described in the second embodiment.

[0075] When the operation of the electrochemical hydrogen pump 100 is stopped, the controller 50 operates the pump 5 in a state where the applied voltage is reduced. Here, the so-called "stopping the operation of the electrochemical hydrogen pump 100" refers to stopping the action for supplying compressed hydrogen generated by the cathode CA from the cathode CA of the electrochemical hydrogen pump 100 to the hydrogen demander (not shown). Furthermore, as a hydrogen demander, for example, a hydrogen storage device, a fuel cell, etc. can be cited. In addition, as a hydrogen storage device, for example, a dispenser and a hydrogen tank provided at a hydrogen station can be cited. In addition, the "state where the applied voltage is reduced" can be a state where the voltage application between the anode AN and the cathode CA is stopped, or it can be a state where a voltage lower than the voltage applied between the anode AN and the cathode CA and greater than 0 is applied before the control (stop control) for stopping the operation of the electrochemical hydrogen pump 100 is about to start.

[0076] The controller 50 includes, for example, a computing circuit (not shown) and a storage circuit (not shown) storing a control program. Examples of the computing circuit include an MPU, a CPU, etc. Examples of the storage circuit include a memory, etc. The controller 50 may be composed of a single controller that performs centralized control, or may be composed of a plurality of controllers that cooperate with each other to perform distributed control.

[0077] [action]

[0078] Hereinafter, an example of hydrogen compression operation of the hydrogen system 200 will be described with reference to the accompanying drawings. The following operation can be performed by, for example, the operation circuit of the controller 50 reading a control program from the storage circuit of the controller 50. However, it is not necessarily necessary to perform the following operation using the controller 50. The operator can perform some of the operations.

[0079] 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 the voltage applicator 21 is supplied to the electrochemical hydrogen pump 100. Then, in the anode catalyst layer of the anode AN, hydrogen molecules are separated into protons and electrons (Formula (1)). The protons are conducted in the electrolyte membrane 20 and move to the cathode catalyst layer. The electrons move to the cathode catalyst layer through the voltage applicator 21.

[0080] Then, hydrogen molecules are generated again in the cathode catalyst layer (Formula (2)). It is known that when protons are conducted in the electrolyte membrane 20, a predetermined amount of water moves from the anode AN to the cathode CA as electroosmotic water along with the protons.

[0081] At this time, for example, when the high-pressure hydrogen generated by the cathode CA of the electrochemical hydrogen pump 100 is supplied to the unillustrated hydrogen storage device through the unillustrated cathode gas outlet flow path, the pressure loss of the cathode gas outlet flow path is increased by using a back pressure valve, a regulating valve (not shown), etc. provided in the cathode gas outlet flow path, thereby compressing the hydrogen (H2) generated in the cathode CA. Here, the so-called increase in the pressure loss of the cathode gas outlet flow path corresponds to reducing the opening of the back pressure valve and the regulating valve provided in the cathode gas outlet flow path.

[0082] Anode: H2 (low pressure) → 2H + +2e-…(1)

[0083] Cathode: 2H + +2e-→H2(high pressure)…(2)

[0084] Thus, in the hydrogen system 200, by applying a voltage between the anode AN and the cathode CA of the electrochemical hydrogen pump 100, the hydrogen in the hydrogen-containing gas supplied to the anode AN is moved to the cathode CA via the electrolyte membrane 20 and compressed. The high-pressure hydrogen generated at the cathode CA is temporarily stored in a hydrogen storage device as an example of a hydrogen demand body after, for example, water and impurities in the hydrogen are removed. In addition, the hydrogen stored in the hydrogen storage device is promptly supplied to a fuel cell as an example of a hydrogen demand body.

[0085] Next, the operation of the electrochemical hydrogen pump 100 is stopped. When the operation is stopped, the voltage between the anode AN and the cathode CA of the electrochemical hydrogen pump 100 decreases.

[0086] Here, when the electrochemical hydrogen pump 100 is, for example, a compressor for a fuel cell forklift, when the hydrogen compression operation is stopped, high-pressure hydrogen of about 40 MPa exists on the cathode CA side. In addition, low-pressure and high-humidity (for example, relative humidity of about 12% at about 50° C.) hydrogen-containing gas of about 0.1 MPa exists on the anode AN side.

[0087] Therefore, the pump 5 is operated in the state where the voltage is lowered. Then, the anode off-gas circulates in the circulation path 4. Thus, the liquid water moved by the circulation of the anode off-gas can be discharged in the drainage path 3.

[0088] As described above, the hydrogen system 200 of the present embodiment can suppress a decrease in the efficiency of the hydrogen compression operation at the time of restart more than in the related art.

[0089] Specifically, the hydrogen system 200 of the present embodiment operates the pump 5 in such a manner that the anode exhaust gas circulates in the circulation path 4 under a state where the applied voltage is reduced when the operation of the electrochemical hydrogen pump 100 is stopped. As a result, after the voltage is reduced, the water that diffuses back from the cathode CA to the anode AN does not remain on the anode AN, and the liquid water in the hydrogen-containing gas that includes the back-diffused water and circulates in the circulation path 4 is discharged through the drainage path 3. Therefore, the hydrogen system 200 of the present embodiment is unlikely to overflow in the anode AN after the operation of the electrochemical hydrogen pump 100 is stopped, so the reduction in the efficiency of the hydrogen compression action at the time of restarting can be suppressed.

[0090] (Variation Example)

[0091] Figure 3 This is a diagram showing an example of a hydrogen system according to a modification of the first embodiment.

[0092] Figure 3 In the illustrated example, the hydrogen system 200 includes an electrochemical hydrogen pump 100 , an anode gas supply path 1 , a recovery path 2 , a drainage path 13 , a pump 5 , a gas-liquid separator 6 , and a controller 50 .

[0093] Here, the electrochemical hydrogen pump 100 , the anode gas supply path 1 , the recovery path 2 , the pump 5 , and the controller 50 are the same as those in the first embodiment, and thus description thereof will be omitted.

[0094] Figure 3 In the example shown, the gas-liquid separator 6 is provided in the recovery flow path 2, and the drainage path 13 is connected to the water storage portion 6A of the gas-liquid separator 6. That is, in the hydrogen system 200 of this modification, the space in the gas-liquid separator 6 constitutes a part of the circulation path 4 in which the anode off-gas discharged from the anode AN circulates.

[0095] However, the arrangement and structure of the gas-liquid separator 6 are merely illustrative and are not limited to this example. For example, although not shown in the figure, a gas-liquid separator may be provided in the anode gas supply path 1 downstream of the point 2A where the anode gas supply path 1 and the recovery path 2 merge.

[0096] As described above, the hydrogen system 200 of this modification promotes separation of liquid water in the hydrogen-containing gas circulating in the circulation path 4 from the hydrogen-containing gas by using the gas-liquid separator 6 , whereby the liquid water in the hydrogen-containing gas is appropriately discharged through the drainage path 13 .

[0097] The hydrogen system 200 of this modification example may be the same as the hydrogen system 200 of the first embodiment except for the above-mentioned features.

[0098] (Second embodiment)

[0099] Figure 4 This is a diagram showing an example of a hydrogen system according to the second embodiment.

[0100] Figure 4 In the illustrated example, the hydrogen system 200 includes an electrochemical hydrogen pump 100 , an anode gas supply path 1 , a recovery path 2 , a drainage path 3 , a pump 15 , and a controller 50 .

[0101] Here, the electrochemical hydrogen pump 100 , the anode gas supply path 1 , the recovery path 2 , the drain path 3 , and the controller 50 are the same as those in the first embodiment, and thus description thereof will be omitted.

[0102] Figure 4 In the example shown, the pump 15 is provided on the anode gas supply path 1 downstream of the portion 2A where the anode gas supply path 1 and the recovery flow path 2 merge, and is a hydrogen purifier that generates purified hydrogen by applying a voltage between an anode and a cathode that are arranged to clamp an electrolyte membrane, so that hydrogen in the hydrogen-containing gas supplied to the anode moves to the cathode. Furthermore, the hydrogen purifier can be composed of an electrochemical hydrogen pump of low-pressure specifications. Thus, for example, by applying a voltage between the cathode and the anode of the hydrogen purifier, hydrogen of about tens to hundreds of KPa can be compressed at the cathode of the hydrogen purifier, that is, hydrogen can be pressurized, and the same function as a pump can be exerted. In this case, except that the stacked components are composed of materials and forms of low-pressure specifications, the stack of the hydrogen purifier is the same as the stack of the electrochemical hydrogen pump 100.

[0103] As described above, the hydrogen system 200 of the present embodiment does not need to be provided with a special circulation pump or the like, and can remove impurities (e.g., CO2) in the hydrogen-containing gas by operating the hydrogen purifier and circulate the hydrogen-containing gas in the circulation path 4. As a result, it is possible to suppress the flooding of the anode AN of the electrochemical hydrogen pump 100 after the operation of the electrochemical hydrogen pump 100 is stopped. At this time, since the hydrogen-containing gas also flows in the hydrogen purifier, it is also possible to suppress the flooding of the hydrogen purifier.

[0104] The hydrogen system 200 of the present embodiment may be the same as the hydrogen system 200 of the first embodiment or the first embodiment modification example except for the above-mentioned features.

[0105] (Third embodiment)

[0106] Figure 5 This is a diagram showing an example of a hydrogen system according to the third embodiment.

[0107] Figure 5 In the illustrated example, the hydrogen system 200 includes an electrochemical hydrogen pump 100 , an anode gas supply path 1 , a recovery path 2 , a drainage path 3 , a pump 5 , a cooler 8 , and a controller 50 .

[0108] Here, the electrochemical hydrogen pump 100 , the anode gas supply path 1 , the recovery path 2 , the drain path 3 , and the pump 5 are the same as those in the first embodiment, and thus description thereof will be omitted.

[0109] The cooler 8 is a device for cooling the electrochemical hydrogen pump 100. Thus, for example, the temperature of the hydrogen-containing gas circulating in the circulation path 4 can be lowered at an early stage compared to the case where the electrochemical hydrogen pump 100 is naturally cooled. Thus, the condensation of water vapor in the hydrogen-containing gas is promoted, and as a result, the dew point of the hydrogen-containing gas is lowered at an early stage.

[0110] The cooler 8 may have various structures as long as it can cool the electrochemical hydrogen pump 100. For example, the cooler 8 may include a device for supplying the cooling medium to a cooling medium flow path (not shown) provided in a member constituting the stack of the electrochemical hydrogen pump 100.

[0111] The controller 50 operates the pump 5 and cools the electrochemical hydrogen pump 100 through the cooler 8. Thus, when the operation of the electrochemical hydrogen pump 100 stops, the electrochemical hydrogen pump 100 can be quickly cooled by controlling the temperature and flow rate of the cooling medium. In addition, as the cooling medium, for example, liquid water, antifreeze, etc. can be cited, but it is not limited thereto.

[0112] As described above, when the operation of the electrochemical hydrogen pump 100 is stopped, the hydrogen-containing gas in the circulation path 4 is circulated. By cooling the electrochemical hydrogen pump 100, not only the water from the reverse diffusion but also the condensed water from the hydrogen-containing gas flowing on the anode AN is effectively discharged through the drainage path 3. That is, the hydrogen system 200 of the present embodiment promotes the removal of water (water vapor and liquid water) on the anode AN compared to the case where the electrochemical hydrogen pump 100 is naturally cooled during the circulation of the hydrogen-containing gas. As a result, the circulation time of the hydrogen-containing gas after the voltage reduction for suppressing the overflow on the anode AN can be shortened.

[0113] The hydrogen system 200 of the present embodiment may be the same as any of the hydrogen systems 200 in the first embodiment, the first embodiment modification, and the second embodiment except for the above-described features.

[0114] (Fourth embodiment)

[0115] Figure 6 This is a diagram showing an example of a hydrogen system according to a fourth embodiment.

[0116] Figure 6 In the illustrated example, the hydrogen system 200 includes an electrochemical hydrogen pump 100 , an anode gas supply path 1 , a recovery path 2 , a drainage path 3 , a pump 5 , a condenser 7 , and a controller 50 .

[0117] Here, the electrochemical hydrogen pump 100 , the anode gas supply path 1 , the recovery path 2 , the drain path 3 , and the pump 5 are the same as those in the first embodiment, and thus description thereof will be omitted.

[0118] The condenser 7 is a device for condensing water vapor in the hydrogen-containing gas. For example, the condenser 7 may include a cooler for cooling the piping constituting the circulation path 4. Thus, for example, compared with the case where the piping is naturally cooled, the temperature of the hydrogen-containing gas circulating in the circulation path 4 can be lowered at an early stage. Thus, the condensation of water vapor in the hydrogen-containing gas is promoted, and as a result, the dew point of the hydrogen-containing gas is lowered at an early stage.

[0119] The condenser 7 can be provided at various locations except for the gas flow path on the anode AN of the electrochemical hydrogen pump 100, as long as it is the circulation path 4, in other words, as long as it is the circulation path 4 outside the electrochemical hydrogen pump 100. For example, the condenser 7 can be provided at the recovery flow path 2, can be provided at the anode gas supply path 1 downstream of the location 2A where the recovery flow path 2 merges, and can also be provided at both the recovery flow path 2 and the anode gas supply path 1.

[0120] However, when the condenser 7 is provided in the recovery flow path 2, it is desirable to provide the condenser 7 at a location where the condensed water generated by the condenser 7 can be easily discharged in the drainage path 3A or the gas-liquid separator 6. Figure 2A In the example shown, it is appropriate to arrange the condenser 7 in the recovery flow path 2 upstream of the drainage path 3A. Figure 3 In the example shown, it is appropriate that the condenser 7 is disposed in the recovery flow path 2 upstream of the gas-liquid separator 6. Thus, the condensed water generated by the condenser 7 moves in the recovery flow path 2 on the downstream side of the condenser 7 through the flow of the anode exhaust gas, and thus the condensed water can be appropriately discharged through the drainage path 3A provided in the recovery flow path 2 or the drainage path 13 provided in the gas-liquid separator 6. The condenser 7 can be composed of a heat exchanger that exchanges heat between a cold medium such as air, water, and antifreeze and the hydrogen-containing gas.

[0121] As described above, when the hydrogen system 200 of the present embodiment circulates the hydrogen-containing gas in the circulation path 4 when the electrochemical hydrogen pump 100 stops operating, the water vapor in the hydrogen-containing gas is condensed by the condenser 7, so that not only the water from the reverse diffusion but also the condensed water from the hydrogen-containing gas is effectively discharged through the drainage path 3. That is, the hydrogen system 200 of the present embodiment promotes the removal of moisture (water vapor and liquid water) on the anode AN compared to the case where the electrochemical hydrogen pump 100 is naturally cooled during the circulation of the hydrogen-containing gas. As a result, the circulation time of the hydrogen-containing gas after the voltage is reduced for suppressing the overflow on the anode AN can be shortened.

[0122] The hydrogen system 200 of the present embodiment may be the same as any of the hydrogen systems 200 of the first embodiment, the first embodiment modification, the second embodiment, and the third embodiment except for the above-described features.

[0123] (Fifth embodiment)

[0124] Figure 7 This is a diagram showing an example of a hydrogen system according to the fifth embodiment.

[0125] Figure 7 In the illustrated example, the hydrogen system 200 includes an electrochemical hydrogen pump 100 , an anode gas supply path 1 , a recovery path 2 , a drainage path 3 , a pump 5 , a flow rate regulator 10 , and a controller 50 .

[0126] Here, the electrochemical hydrogen pump 100 , the anode gas supply path 1 , the recovery path 2 , the drain path 3 , and the pump 5 are the same as those in the first embodiment, and thus description thereof will be omitted.

[0127] The flow regulator 10 is a device for regulating the flow rate of the hydrogen-containing gas in the anode gas supply path 1 upstream of the portion 2A where the anode gas supply path 1 and the recovery flow path 2 merge. The flow regulator 10 may be of various structures as long as the flow rate of the hydrogen-containing gas can be regulated. As the flow regulator 10, a flow regulating device including a flow regulating valve, a mass flow controller, or a booster may be exemplified. Furthermore, the flow regulator 10 may also include a flow meter together with the above-mentioned flow regulating device.

[0128] Here, the hydrogen-containing gas is supplied from the hydrogen-containing gas supply source to the flow regulating device. As described above, the hydrogen-containing gas supply source may include a reformer, a water electrolysis device, a hydrogen tank, etc. Furthermore, when the hydrogen-containing gas supply source has a predetermined supply pressure, the flow rate of the hydrogen-containing gas in the anode gas supply path 1 may be adjusted by controlling the opening of a flow regulating valve as an example of the flow regulating device.

[0129] The controller 50 controls the flow regulator 10 when the pump 5 is working, gradually reduces the flow rate of the hydrogen-containing gas, and gradually reduces the output power of the pump 5, and then stops the pump 5. Furthermore, although not shown in the figure, the detectors required for the control of the flow regulator 10 and the pump 5 by the controller 50 are appropriately provided. Specifically, for example, the hydrogen system 200 has a temperature detector and a voltage detector. The temperature detector is a sensor that detects the temperature of the stack of the electrochemical hydrogen pump 100, and for example, a thermistor, a thermocouple, etc. can be used. The voltage detector is a voltage sensor that detects the potential difference applied between the anode AN and the cathode CA of the electrochemical hydrogen pump 100.

[0130] Figure 8 This is a flowchart showing an example of the operation of the hydrogen system according to the fifth embodiment. Figure 8 The operation shown can be performed, for example, by the operation circuit of the controller 50 reading the control program from the storage circuit of the controller 50. However, it is not necessary to perform the operation using the controller 50. The operator can perform part of the operation.

[0131] First, when the stop control of the hydrogen system 200 is started, the voltage between the anode AN and the cathode CA is reduced by the voltage applicator 21. For example, the voltage between the anode AN and the cathode CA may be set to zero volt.

[0132] Next, in step S11, the flow rate regulator 10 is controlled so that the flow rate of the hydrogen-containing gas gradually decreases over time, and in step S12, the pump 5 is controlled so that the pump output gradually decreases over time. At this time, the actions of step S11 and step S12 are performed in such a way that they overlap in time.

[0133] Next, in step S13, it is determined whether the stack temperature of the electrochemical hydrogen pump 100 is equal to or lower than a predetermined temperature. The "predetermined temperature" in step S13 may be, for example, approximately 30°C, but is not limited thereto.

[0134] Here, when the stack temperature of the electrochemical hydrogen pump 100 exceeds the predetermined temperature (in the case of "NO" in step S13), this state is maintained.

[0135] When the stack temperature of the electrochemical hydrogen pump 100 reaches or falls below the predetermined temperature (if "yes" in step S13), the process proceeds to the next step, in step S14, the flow regulator 10 is controlled to make the flow rate of the hydrogen-containing gas zero, and in step S15, the pump 5 is controlled to stop the pump output. Figure 8 In the figure, the action of step S14 is shown to be performed before the action of step S15, but the present invention is not limited thereto. Although the figure is omitted, the action of step S14 and the action of step S15 may be performed simultaneously, or the action of step S15 may be performed before the action of step S14.

[0136] Furthermore, the above actions are only examples and are not limited to this example. For example, in the judgment of step S13, "the operating time of the pump 5" or the like can be used instead of "the stack temperature". In this case, when the operating time of the pump 5 reaches or exceeds the predetermined time, the actions of step S14 and step S15 are performed.

[0137] As described above, when the electrochemical hydrogen pump 100 is stopped, the hydrogen system 200 of this embodiment can properly discharge liquid water through the drainage path 3 while operating the pump 5 to circulate the anode off-gas in the circulation path 4 .

[0138] Specifically, in the hydrogen system 200 of the present embodiment, when the electrochemical hydrogen pump 100 stops operating, the pump 5 is operated to circulate the anode exhaust gas in the circulation path 4. As the temperature of the electrochemical hydrogen pump 100 decreases over time, water vapor in the hydrogen-containing gas on the anode AN condenses. As a result, the pressure decreases as the gas molecule molar amount of the hydrogen-containing gas present in the circulation path 4 decreases, and thus the circulation path 4 may become negatively pressurized. As a result, due to the intrusion of air into the circulation path 4 from the outside, the components of the electrochemical hydrogen pump 100 may be deteriorated.

[0139] Therefore, the hydrogen system 200 of this embodiment uses a flow regulator 10 to inject hydrogen-containing gas into the circulation path 4 from the anode gas supply path 1 upstream of the point 2A where the anode gas supply path 1 merges with the recovery path 2 to compensate for the pressure reduction of the hydrogen-containing gas in the above-mentioned circulation path 4, thereby suppressing the negative pressure in the circulation path 4.

[0140] In addition, it can be easily understood from the curve of the amount of saturated water vapor in the hydrogen-containing gas related to the temperature of the hydrogen-containing gas that the amount of water condensed from the water vapor in the hydrogen-containing gas decreases as the temperature of the hydrogen-containing gas decreases over time. Therefore, the hydrogen system 200 of the present embodiment can inject an appropriate amount of hydrogen-containing gas from the upstream side of the anode gas supply path 1 into the circulation path 4 by gradually reducing the flow rate and pump output of the hydrogen-containing gas over time.

[0141] The hydrogen system 200 of the present embodiment may be the same as any of the hydrogen systems 200 of the first embodiment, the first embodiment modification, the second embodiment, the third embodiment, and the fourth embodiment except for the above-described features.

[0142] (Variation Example)

[0143] The hydrogen system 200 of the present modification is the same as the hydrogen system 200 of the fifth embodiment except for the control contents of the flow rate regulator 10 and the pump 5 by the controller 50 described below.

[0144] When an abnormality occurs and the electrochemical hydrogen pump 100 stops operating, and the hydrogen-containing gas supply source cannot supply the hydrogen-containing gas, the controller 50 gradually reduces the output power of the pump 5 without controlling the flow regulator 10 , and then stops the pump 5 .

[0145] Fig. 9 This is a flowchart showing an example of the operation of the hydrogen system according to the modification of the fifth embodiment. Fig. 9The operation shown can be performed, for example, by the operation circuit of the controller 50 reading the control program from the storage circuit of the controller 50. However, it is not necessarily necessary to use the controller 50 to perform this operation. The operator can perform part of the operation. Furthermore, the system stop control caused by power failure, etc., can be performed in the same manner as in the fifth embodiment ( Figure 8 ) performs the same actions as the hydrogen system 200.

[0146] First, when the stop control of the hydrogen system 200 is started, the voltage between the anode AN and the cathode CA is reduced by the voltage applicator 21. For example, the voltage between the anode AN and the cathode CA may be set to zero volt.

[0147] Next, in step S12 , the pump 5 is controlled so that the pump output power gradually decreases with the passage of time.

[0148] Next, in step S13, it is determined whether the stack temperature of the electrochemical hydrogen pump 100 is equal to or lower than a predetermined temperature. The "predetermined temperature" in step S13 may be, for example, approximately 30°C, but is not limited thereto.

[0149] Here, when the stack temperature of the electrochemical hydrogen pump 100 exceeds the predetermined temperature (in the case of NO in step S13 ), this state is maintained.

[0150] When the stack temperature of the electrochemical hydrogen pump 100 reaches or falls below the predetermined temperature (if "yes" in step S13), the process proceeds to the next step, and in step S15, the pump 5 is controlled to stop the pump output. Figure 8 The action of step S11 and the action of step S14 are used to perform the stop control of the hydrogen system 200 caused by the abnormality.

[0151] As described above, the hydrogen system 200 of the present modification example can appropriately perform the stop control of the system when the hydrogen-containing gas cannot be supplied due to an abnormality in the supply source of the hydrogen-containing gas.

[0152] The hydrogen system 200 of the present embodiment may be the same as any of the hydrogen systems 200 of the first embodiment, the first embodiment modification, the second embodiment, the third embodiment, the fourth embodiment, and the fifth embodiment except for the above-described features.

[0153] The first embodiment, the first embodiment modification, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, and the fifth embodiment modification may be combined with each other as long as they do not exclude each other.

[0154] In addition, based on the above description, many improvements and other embodiments of the present invention are obvious to those skilled in the art. Therefore, the above description should be interpreted as an example only, and is provided for the purpose of teaching those skilled in the art the best way to implement the present disclosure. The details of its structure and / or function may be substantially changed without departing from the spirit of the present disclosure.

[0155] Industrial Applicability

[0156] An aspect of the present disclosure can be applied to a hydrogen system, and can suppress a decrease in efficiency of a hydrogen compression operation at the time of restart more than before.

[0157] Description of Reference Numerals

[0158] 1: Anode gas supply path

[0159] 2: Recovery flow path

[0160] 2A: Location

[0161] 3: Drainage path

[0162] 3A: Drainage Path

[0163] 3B: Drainage Path

[0164] 4: Cycle Path

[0165] 5: Pump

[0166] 5A: Pump

[0167] 5B: Pump

[0168] 6: Gas-liquid separator

[0169] 6A: Water storage

[0170] 7: Condenser

[0171] 8: Cooler

[0172] 10: Flow regulator

[0173] 13: Drainage path

[0174] 15: Pump

[0175] 20: Electrolyte membrane

[0176] 21: Voltage applicator

[0177] 50: Controller

[0178] 100: Electrochemical hydrogen pump

[0179] 200: Hydrogen system

[0180] AN: Anode

[0181] CA: cathode

Claims

1. A hydrogen system comprising a compressor, an anode gas supply path, a recovery flow path, a drainage path, a pump and a controller, The compressor applies a voltage between an anode and a cathode disposed with an electrolyte membrane interposed therebetween, thereby causing hydrogen in the hydrogen-containing gas supplied to the anode to move to the cathode, thereby generating compressed hydrogen. The anode gas supply path is used to flow the hydrogen-containing gas supplied to the anode. The recovery flow path is used to flow the anode exhaust gas discharged from the anode and then merged with the anode gas supply path. The drainage path is provided in the recovery flow path, or in the anode gas supply path downstream of the location where the anode gas supply path and the recovery flow path merge, and is used to discharge liquid water to the outside of the recovery flow path or the outside of the anode gas supply path. The pump is provided in the recovery flow path, or in the anode gas supply path downstream of a portion where the anode gas supply path merges with the recovery flow path. When the operation of the compressor is stopped, the controller operates the pump in a state where the voltage applied to the compressor is reduced.

2. According to the hydrogen system of claim 1, a gas-liquid separator is provided on the recovery flow path or on the anode gas supply path downstream of the location where the anode gas supply path merges with the recovery flow path, and the drainage path is connected to the water storage part of the gas-liquid separator.

3. In the hydrogen system according to claim 1 or 2, the pump is arranged on the anode gas supply path downstream of the point where the anode gas supply path merges with the recovery flow path, and is a hydrogen purifier that applies a voltage between an anode and a cathode arranged to clamp an electrolyte membrane to move hydrogen in the hydrogen-containing gas supplied to the anode to the cathode to generate purified hydrogen.

4. The hydrogen system according to claim 1 or 2, A cooler is provided for cooling the compressor, The controller operates the pump and cools the compressor through the cooler. 5 . The hydrogen system according to claim 1 , further comprising a condenser, wherein the condenser is provided in the recovery flow path or in the anode gas supply path downstream of a portion where the anode gas supply path merges with the recovery flow path.

6. The hydrogen system according to claim 1 or 2, A flow rate regulator is provided for regulating the flow rate of the hydrogen-containing gas in the anode gas supply path upstream of a location where the anode gas supply path merges with the recovery path, When the pump is working, the controller controls the flow regulator to gradually reduce the flow of the hydrogen-containing gas and the output power of the pump, and then stops the pump.

7. In the hydrogen system according to claim 6, when an abnormality occurs and causes the compressor to stop operating, thereby making it impossible to supply hydrogen-containing gas from the hydrogen-containing gas supply source, the controller gradually reduces the output power of the pump without controlling the flow regulator, and then stops the pump.

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