JP2020037724A - Hydrogen system - Google Patents

Abstract

To provide a hydrogen system that can improve the efficiency of an electrochemical-type hydrogen pump during a hydrogen boosting operation.SOLUTION: A hydrogen system comprises: an electrochemical-type hydrogen pump in which a proton taken out of an anode fluid at an anode moves through an electrolyte film, and hydrogen boosted at a cathode is generated; a gas-liquid separator for separating the hydrogen to be discharged from the cathode from the moisture discharged together with the discharged hydrogen; a first valve for discharging the water in the gas-liquid separator; and a controller for opening the first valve when the pressure of the hydrogen boosted at the cathode is equal to or smaller than a first pressure that is smaller than the boost upper limit of the electrochemical-type hydrogen pump.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to hydrogen systems.

  In recent years, hydrogen has been attracting attention as a clean alternative energy source to fossil fuels due to environmental problems such as global warming and energy problems such as depletion of petroleum resources. Hydrogen basically emits only water when burned, does not emit carbon dioxide, which causes global warming, and emits almost no nitrogen oxides, so it is expected as clean energy. Further, as a device that uses hydrogen as a fuel with high efficiency, for example, there is a fuel cell, and the development and widespread use of a fuel cell for a power source for an automobile and a private power generation system for a household are progressing.

  In the coming hydrogen society, in addition to producing hydrogen, there is a demand for technology development that can store hydrogen at a high density and transport or use it at a small capacity and at low cost. In particular, in order to promote the spread of fuel cells, which are distributed energy sources, it is necessary to improve the fuel supply infrastructure.

  In order to stably supply hydrogen to the fuel supply infrastructure, various proposals have been made for purifying and pressurizing high-purity hydrogen.

  For example, Patent Literature 1 discloses a water electrolysis apparatus that generates high-pressure hydrogen while performing water electrolysis.

  Here, hydrogen generated by the electrolysis of water contains moisture. Therefore, when such hydrogen is stored in a hydrogen storage device such as a tank, if there is a large amount of water contained in the hydrogen, the amount of hydrogen in the hydrogen storage device is reduced due to the presence of the water in the hydrogen storage device. Not a target. There is also a problem that moisture contained in hydrogen solidifies in the hydrogen storage. For this reason, it is desired that the water content of hydrogen stored in the hydrogen storage be reduced to, for example, about 5 ppm or less.

  Therefore, in Patent Document 1, a gas-liquid separator for separating hydrogen and water on a flow path of hydrogen between the water electrolysis device and the hydrogen storage, and a gas-liquid separator for adsorbing and removing moisture from hydrogen. A hydrogen generation system provided with an adsorption tower has been proposed.

  Hydrogen is dissolved in water in a gas-liquid separator for separating high-pressure hydrogen generated by electrolysis of water from water. Therefore, when the water in the gas-liquid separator is drained to the outside in this state, the hydrogen in the drain is discharged to the outside.

  Therefore, Patent Document 2 proposes a system in which a gas-liquid separator is provided with a gas-phase depressurizing line for separating water and high-pressure hydrogen generated by electrolysis of water. Thereby, before draining the water in the gas-liquid separator, the internal pressure of the gas-liquid separator can be reduced, so that the amount of hydrogen in the drain can be reduced.

JP 2009-179842 A JP 2012-219293 A

  However, in the conventional example, the efficiency improvement of the electrochemical hydrogen pump at the time of increasing the hydrogen pressure has not been sufficiently studied.

  An aspect of the present disclosure has been made in view of such circumstances, and provides a hydrogen system capable of improving the efficiency of an electrochemical hydrogen pump during a hydrogen boosting operation as compared with the related art.

  In order to solve the above problem, a hydrogen system according to an embodiment of the present disclosure includes an electrochemical hydrogen pump in which protons extracted from an anode fluid at an anode move through an electrolyte membrane and pressurized hydrogen is generated at a cathode. A gas-liquid separator for separating hydrogen discharged from the cathode and moisture discharged along with the discharged hydrogen, and a first valve for discharging water in the gas-liquid separator. A controller that opens the first valve when the pressure of the boosted hydrogen is equal to or lower than a first pressure that is smaller than an upper limit pressure of the electrochemical hydrogen pump.

  The hydrogen system according to one embodiment of the present disclosure has an effect that the efficiency of the electrochemical hydrogen pump at the time of increasing the pressure of hydrogen can be improved as compared with the related art.

FIG. 1 is a diagram illustrating an example of the hydrogen system according to the first embodiment. FIG. 2A is a diagram illustrating an example of an electrochemical hydrogen pump of the hydrogen system according to the first embodiment. FIG. 2B is an enlarged view of part B of the electrochemical hydrogen pump of FIG. 2A. FIG. 3A is a diagram illustrating an example of an electrochemical hydrogen pump of the hydrogen system according to the first embodiment. FIG. 3B is an enlarged view of part B of the electrochemical hydrogen pump of FIG. 3A. FIG. 4 is a flowchart illustrating an example of the operation of the hydrogen system according to the first embodiment. FIG. 5 is a flowchart illustrating an example of the operation of the hydrogen system according to the modification of the first embodiment. FIG. 6 is a diagram illustrating an example of the hydrogen system according to the second embodiment. FIG. 7 is a flowchart illustrating an example of the operation of the hydrogen system according to the second embodiment. FIG. 8 is a flowchart illustrating an example of the operation of the hydrogen system according to the third embodiment. FIG. 9 is a diagram illustrating an example of the hydrogen system according to the fourth embodiment.

  When the hydrogen discharged from the cathode of the electrochemical hydrogen pump and the water accompanying the hydrogen are separated by the gas-liquid separator, the gas is separated into the gas-liquid separator as the hydrogen pressurizing operation of the electrochemical hydrogen pump proceeds. As the amount of liquid water present increases, it is necessary to discharge such water out of the gas-liquid separator in a timely manner. Here, hydrogen is dissolved in the water in the gas-liquid separator, and is dissolved in the water present in the gas-liquid separator as the pressure of the hydrogen pressurized at the cathode of the electrochemical hydrogen pump is higher. The concentration of hydrogen increases.

  Therefore, if the water in the gas-liquid separator is discharged to the outside in a state where the dissolved hydrogen concentration in the water in the gas-liquid separator is increased, the gas-liquid separation is performed when the inside of the gas-liquid separator is not in such a state. The amount of hydrogen discharged to the outside of the gas-liquid separator increases as compared with the case where water in the container is discharged to the outside. As a result, the efficiency of the electrochemical hydrogen pump at the time of the hydrogen pressure raising operation is reduced.

  Therefore, the inventors have conducted intensive studies and, as a result, determined the timing of discharging the water present in the gas-liquid separator to the outside in consideration of the concentration of dissolved hydrogen in the water in the gas-liquid separator. The inventors have found that hydrogen discharged to the outside of the gas-liquid separator can be reduced, and have reached the following one embodiment of the present disclosure.

  That is, the hydrogen system according to the first aspect of the present disclosure includes an electrochemical hydrogen pump in which protons extracted from the anode fluid at the anode move through the electrolyte membrane to generate pressurized hydrogen at the cathode, and discharge from the cathode. Gas-liquid separator for separating the hydrogen to be discharged and the water discharged along with the discharged hydrogen, a first valve for discharging the water in the gas-liquid separator, and the pressure increased at the cathode. A controller for opening the first valve when the pressure of the hydrogen is equal to or lower than a first pressure smaller than an upper pressure limit of the electrochemical hydrogen pump.

  Further, in the hydrogen system according to the second aspect of the present disclosure, in the hydrogen system according to the first aspect, the controller is configured to increase the pressure of the hydrogen generated at the cathode at the cathode when the pressure value of the electrochemical hydrogen pump is increasing. The first valve may be opened at least once when the pressure of the generated hydrogen is equal to or lower than the first pressure.

  According to the above configuration, the hydrogen system of the present embodiment can improve the efficiency of the electrochemical hydrogen pump at the time of increasing the hydrogen pressure as compared with the related art.

  Specifically, the concentration of dissolved hydrogen in the water in the gas-liquid separator increases as the pressure of hydrogen increased at the cathode of the electrochemical hydrogen pump increases. Therefore, in the hydrogen system of this aspect, the first valve for discharging the water in the gas-liquid separator to the outside is opened at an appropriate timing when the pressure of the hydrogen pressurized at the cathode is equal to or lower than the first pressure. are doing. Accordingly, the hydrogen system according to the present embodiment provides a gas-liquid separator for discharging water in the gas-liquid separator to the outside, as compared with the case where the first valve is opened when the pressure of hydrogen exceeds the first pressure. Since the concentration of dissolved hydrogen in the water in the separator is low, the amount of hydrogen discharged outside the gas-liquid separator can be reduced. As a result, in the hydrogen system of this embodiment, the efficiency of the electrochemical hydrogen pump at the time of increasing the pressure of hydrogen is improved.

  In addition, the hydrogen system according to the present aspect appropriately discharges water existing in the gas-liquid separator to the outside before the pressure of the hydrogen pressurized at the cathode reaches the first pressure. Within, the amount of water in a state where the dissolved hydrogen concentration is increased can be reduced. As a result, in the hydrogen system of this embodiment, the efficiency of the electrochemical hydrogen pump at the time of increasing the pressure of hydrogen is improved.

  In the hydrogen system according to the third aspect of the present disclosure, in the hydrogen system according to the first aspect or the second aspect, the controller may be configured to: The first valve may be opened irrespective of the water level.

  According to this configuration, the hydrogen system of the present embodiment, when the pressure of the hydrogen pressurized at the cathode is equal to or lower than the first pressure, changes the water in the gas-liquid separator regardless of the water level in the gas-liquid separator. By opening the first valve for discharging, the water with a low dissolved hydrogen concentration can be removed from the gas-liquid separator without waiting for the water level in the gas-liquid separator to rise and before the hydrogen pressure becomes high. Can be discharged.

  In the hydrogen system according to the fourth aspect of the present disclosure, in the hydrogen system according to any one of the first aspect to the third aspect, the controller may be configured so that the pressure of the hydrogen boosted at the cathode is equal to or lower than the first pressure, and When the water level in the liquid separator is equal to or higher than the reference, the first valve may be opened.

  According to this configuration, the hydrogen system according to the present embodiment provides a gas-liquid separator at a time when the pressure of hydrogen boosted at the cathode is equal to or lower than the first pressure and the water level in the gas-liquid separator is equal to or higher than the reference water level. The water in the separator can be discharged to the outside.

  A hydrogen system according to a fifth aspect of the present disclosure is the hydrogen system according to any one of the first aspect to the fourth aspect, wherein the hydrogen discharged from the cathode of the electrochemical hydrogen pump and flowing into the gas-liquid separator flows through the flow path. The controller is provided with a second valve provided, and the controller is configured so that the pressure of the hydrogen pressurized at the cathode is higher than the first pressure and equal to or higher than a second pressure that is equal to or lower than the upper limit of the pressure of the electrochemical hydrogen pump. Then, the second valve may be closed.

  According to such a configuration, the hydrogen system of the present embodiment can improve the efficiency of the electrochemical hydrogen pump during the hydrogen pressurizing operation as compared with the conventional case.

  Specifically, the concentration of dissolved hydrogen in the water in the gas-liquid separator increases as the pressure of hydrogen increased at the cathode of the electrochemical hydrogen pump increases. Therefore, the hydrogen system of the present embodiment, when the pressure of the hydrogen pressurized at the cathode is higher than the first pressure and equal to or higher than the second pressure which is equal to or lower than the upper limit of the pressure of the electrochemical hydrogen pump, becomes gas-liquid. By closing the second valve provided in the flow path through which the hydrogen flowing into the separator flows, it is possible to suppress an increase in the amount of hydrogen dissolved in the water present in the gas-liquid separator. As a result, in the hydrogen system of this embodiment, the efficiency of the electrochemical hydrogen pump at the time of increasing the hydrogen pressure is improved.

  Here, when the pressure of the hydrogen pressurized at the cathode increases, water is generated at the cathode by condensing the amount of water vapor contained in the hydrogen. Then, a part of the water present in the cathode is pushed back from the cathode to the anode through the electrolyte membrane due to the pressure difference between the cathode and the anode. As a result, as the pressure of hydrogen increased at the cathode becomes higher, the amount of water contained in hydrogen discharged from the cathode decreases. Therefore, when the pressure of the hydrogen pressurized at the cathode is equal to or higher than the second pressure, the amount of water contained in the hydrogen discharged from the cathode is very small, and the hydrogen pressurized at the cathode passes through the gas-liquid separator. Even if the second valve is closed so as not to cause such a problem, the water contained in the hydrogen can be appropriately treated.

  For example, even when moisture contained in hydrogen pressurized at the cathode is adsorbed and removed by an adsorbent of an appropriate moisture remover, deterioration of the moisture adsorption performance of the adsorbent can be appropriately reduced.

  That is, in the hydrogen system according to the sixth aspect of the present disclosure, in the hydrogen system according to any one of the first aspect to the fifth aspect, the hydrogen system is provided in the flow path between the gas-liquid separator and the hydrogen utilization device, and the hydrogen is entrained. A moisture removing device including an adsorbent for removing moisture to be removed.

  According to such a configuration, the hydrogen system of the present embodiment can adsorb and remove water contained in hydrogen such as water vapor that cannot be separated by the gas-liquid separator by the adsorbent of the water remover. Thereby, dry hydrogen can be supplied to an appropriate hydrogen utilization device.

  Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Each of the embodiments described below is an example of each of the above aspects. Therefore, the shapes, materials, components, and the arrangement positions and connection forms of the components shown below are merely examples, and do not limit the above embodiments unless otherwise described in the claims. . In addition, among the following components, components not described in the independent claims that indicate the highest concept of each aspect described above are described as arbitrary components. Also, in the drawings, the description of the same reference numeral may be omitted. In the drawings, each component is schematically shown for easy understanding, and shapes and dimensional ratios may not be accurately displayed.

  In operation, the order of each step and the like can be changed as necessary. Further, other known steps can be added as necessary.

(1st Embodiment)
[Configuration of hydrogen system]
FIG. 1 is a diagram illustrating an example of the hydrogen system according to the first embodiment.

  In the example illustrated in FIG. 1, the hydrogen system 200 includes an electrochemical hydrogen pump 100, a gas-liquid separator 110, a first valve 120, and a controller 50.

The electrochemical hydrogen pump 100 is a device in which protons (H ⁺ ) taken out of an anode fluid at an anode AN move through an electrolyte membrane 11 to generate hydrogen (H ₂ ) pressurized at a cathode CA. The electrochemical hydrogen pump 100 may have any configuration as long as it is an electrochemical booster using the electrolyte membrane 11.

  For example, in the electrochemical hydrogen pump 100 of FIG. 1, the anode fluid introduction passage 29 through which the anode fluid supplied to the anode AN flows, the anode fluid outlet passage 31 through which the anode fluid discharged from the anode AN flows, and the cathode CA And a cathode gas outlet path 26 through which hydrogen discharged from the fuel cell flows. A detailed configuration of such an electrochemical hydrogen pump 100 will be described later.

The anode fluid may be any substance as long as protons are generated by an electrochemical reaction on the anode AN. Examples of such an anode fluid include water, hydrogen (H ₂ ), and the like.

  The gas-liquid separator 110 is a device that separates hydrogen discharged from the cathode CA and moisture discharged along with the hydrogen discharged from the cathode CA. The gas-liquid separator 110 may have any configuration as long as it can separate moisture discharged along with such hydrogen from hydrogen. The gas-liquid separator 110 is provided on the cathode gas outlet path 26.

  The first valve 120 is a valve for discharging water from the gas-liquid separator 110. The first valve 120 may have any configuration as long as water in the gas-liquid separator 110 can be discharged. An example of the first valve 120 is an electromagnetic valve.

  In the hydrogen system 200 of the present embodiment, the gas-liquid separator 110 includes a tank 110A for storing water separated from hydrogen, as shown in FIG. A hydrogen inlet and a hydrogen outlet are provided on the upper wall of the tank 110A, and a pipe constituting the cathode gas outlet path 26 is connected to each of the hydrogen inlet and the hydrogen outlet. . A drain pipe for discharging water in the tank 110A to the outside is connected to a lower wall of the tank 110A, and a first valve 120 is provided in the drain pipe.

  As described above, when hydrogen discharged from the cathode CA of the electrochemical hydrogen pump 100 to the cathode gas outlet path 26 passes through the inside of the tank 110A, hydrogen and moisture are separated. The water separated from the hydrogen accumulates in the tank 110A. Then, as the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 progresses, the amount of liquid water present in the tank 110A increases, and such water is discharged to the outside of the tank 110A in a timely manner by opening and closing the first valve 120. Is done. The hydrogen from which water has been removed by the gas-liquid separator 110 is discharged out of the tank 110A through a hydrogen outlet provided on the upper wall of the tank 110A.

  The controller 50 performs gas-liquid separation when the pressure P of the hydrogen boosted at the cathode CA of the electrochemical hydrogen pump 100 is equal to or less than a first pressure P1 smaller than the boosting upper limit PL of the electrochemical hydrogen pump 100. The first valve 120 for discharging the water in the vessel 110 is opened.

  Conversely, the controller 50 does not open the first valve 120 when the pressure P of the hydrogen boosted at the cathode CA is higher than the first pressure P1.

  Note that the first pressure P1 may be set to any pressure as long as it is smaller than the pressure increase upper limit PL of the electrochemical hydrogen pump 100. For example, as the pressure P of the hydrogen boosted at the cathode CA of the electrochemical hydrogen pump 100 increases, the concentration of dissolved hydrogen in the water in the gas-liquid separator 110 increases. Therefore, the first pressure P1 may be, for example, a predetermined pressure at which the concentration of dissolved hydrogen in water in the gas-liquid separator 110 does not exceed an allowable value.

  As an example, the pressure increase upper limit PL of the electrochemical hydrogen pump 100 may be about 40 Mpa, and the first pressure P1 may be about 30 MPa. In addition, these pressure values are examples, and are not limited to the present example.

  The controller 50 includes, for example, an arithmetic circuit (not shown) and a storage circuit (not shown) for storing a control program. Examples of the arithmetic circuit include an MPU and a CPU. As the storage circuit, for example, a memory can be given. The controller 50 may be configured by a single controller that performs centralized control, or may be configured by a plurality of controllers that perform distributed control in cooperation with each other. Controller 50 may control the overall operation of hydrogen system 200.

[Configuration of electrochemical hydrogen pump]
2A and 3A are diagrams illustrating an example of an electrochemical hydrogen pump of the hydrogen system according to the first embodiment. FIG. 2B is an enlarged view of part B of the electrochemical hydrogen pump of FIG. 2A. FIG. 3B is an enlarged view of part B of the electrochemical hydrogen pump of FIG. 3A.

  2A shows a vertical cross section of the electrochemical hydrogen pump 100 including a straight line passing through the center of the electrochemical hydrogen pump 100 and the center of the cathode gas outlet manifold 28 in plan view. FIG. 3A shows a vertical view of the electrochemical hydrogen pump 100 including a straight line passing through the center of the electrochemical hydrogen pump 100, the center of the anode fluid introduction manifold 27, and the center of the anode fluid outlet manifold 30 in plan view. A cross section is shown.

  2A and 3A, the electrochemical hydrogen pump 100 includes at least one hydrogen pump unit 100A.

  Note that a plurality of hydrogen pump units 100A are stacked on the electrochemical hydrogen pump 100. For example, in FIGS. 2A and 3A, the three-stage hydrogen pump units 100A are stacked, but the number of hydrogen pump units 100A is not limited to this. That is, the number of hydrogen pump units 100A can be set to an appropriate number based on operating conditions such as the amount of hydrogen that the electrochemical hydrogen pump 100 increases in pressure.

  The hydrogen pump unit 100A includes an electrolyte membrane 11, an anode AN, a cathode CA, a cathode separator 16, an anode separator 17, and an insulator 21. In the hydrogen pump unit 100A, the electrolyte membrane 11, the anode catalyst layer 13, the cathode catalyst layer 12, the anode fluid diffusion layer 15, the cathode gas diffusion layer 14, the anode separator 17, and the cathode separator 16 are stacked.

  The anode AN is provided on one main surface of the electrolyte membrane 11. The anode AN is an electrode including the anode catalyst layer 13 and the anode fluid diffusion layer 15. In a plan view, an annular seal member 43 is provided so as to surround the periphery of the anode catalyst layer 13, and the anode catalyst layer 13 is appropriately sealed by the seal member 43.

  Cathode CA is provided on the other main surface of electrolyte membrane 11. The cathode CA is an electrode including the cathode catalyst layer 12 and the cathode gas diffusion layer 14. In a plan view, an annular seal member 42 is provided so as to surround the periphery of the cathode catalyst layer 12, and the cathode catalyst layer 12 is appropriately sealed by the seal member 42.

  As described above, the electrolyte membrane 11 is sandwiched between the anode AN and the cathode CA so as to be in contact with each of the anode catalyst layer 13 and the cathode catalyst layer 12. Note that a laminate of the cathode CA, the electrolyte membrane 11, and the anode AN is referred to as a membrane-electrode assembly (hereinafter, MEA: Membrane Electrode Assembly).

  The electrolyte membrane 11 has proton conductivity. The electrolyte membrane 11 may have any configuration as long as it has proton conductivity. For example, examples of the electrolyte membrane 11 include a fluorine-based polymer electrolyte membrane and a hydrocarbon-based polymer electrolyte membrane, but are not limited thereto. Specifically, for example, Nafion (registered trademark, manufactured by DuPont), Aciplex (registered trademark, manufactured by Asahi Kasei Corporation) or the like can be used as the electrolyte membrane 11.

  The anode catalyst layer 13 is provided on one main surface of the electrolyte membrane 11. The anode catalyst layer 13 includes, for example, platinum as a catalyst metal, but is not limited thereto.

  The cathode catalyst layer 12 is provided on the other main surface of the electrolyte membrane 11. The cathode catalyst layer 12 includes, for example, platinum as a catalyst metal, but is not limited thereto.

  Examples of the catalyst carrier of the cathode catalyst layer 12 and the anode catalyst layer 13 include, but are not limited to, carbon powder such as carbon black and graphite, and conductive oxide powder.

  In the cathode catalyst layer 12 and the anode catalyst layer 13, catalyst metal fine particles are supported in a highly dispersed manner on a catalyst carrier. In general, a hydrogen ion conductive ionomer component is added to the cathode catalyst layer 12 and the anode catalyst layer 13 in order to increase the electrode reaction field.

  The cathode gas diffusion layer 14 is provided on the cathode catalyst layer 12. In addition, the cathode gas diffusion layer 14 is made of a porous material and has conductivity and gas diffusion properties. Further, it is desirable that the cathode gas diffusion layer 14 has elasticity so as to appropriately follow the displacement and deformation of the components caused by the pressure difference between the cathode CA and the anode AN when the electrochemical hydrogen pump 100 operates. In the electrochemical hydrogen pump 100 of the present embodiment, a member made of carbon fiber is used as the cathode gas diffusion layer 14. For example, a porous carbon fiber sheet such as carbon paper, carbon cloth, and carbon felt may be used. Note that the carbon fiber sheet need not be used as the base material of the cathode gas diffusion layer 14. For example, the base material of the cathode gas diffusion layer 14 may be a sintered body of metal fibers made of titanium, a titanium alloy, stainless steel, or the like, or a sintered body of metal powder made of these materials.

  The anode fluid diffusion layer 15 is provided on the anode catalyst layer 13. Further, the anode fluid diffusion layer 15 is made of a porous material, and has conductivity and gas diffusion properties. Further, it is desirable that the anode fluid diffusion layer 15 has a high rigidity capable of suppressing displacement and deformation of the constituent members caused by a pressure difference between the cathode CA and the anode AN during the operation of the electrochemical hydrogen pump 100.

  In the electrochemical hydrogen pump 100 according to the present embodiment, a member formed of a thin plate of a titanium powder sintered body is used as the anode fluid diffusion layer 15, but the anode fluid diffusion layer 15 is not limited to this. That is, as the base material of the anode fluid diffusion layer 15, for example, a sintered body of metal fibers made of titanium, a titanium alloy, stainless steel, or the like, or a sintered body of metal powder made of these materials can be used. . Further, as a base material of the anode fluid diffusion layer 15, for example, an expanded metal, a metal mesh, a punching metal, or the like can be used.

  The anode separator 17 is a member provided on the anode fluid diffusion layer 15 of the anode AN. The cathode separator 16 is a member provided on the cathode gas diffusion layer 14 of the cathode CA.

  A concave portion is provided at the center of each of the cathode separator 16 and the anode separator 17. Each of these recesses accommodates a cathode gas diffusion layer 14 and an anode fluid diffusion layer 15, respectively.

  In this way, the hydrogen pump unit 100A is formed by sandwiching the MEA between the cathode separator 16 and the anode separator 17.

  On the main surface of the cathode separator 16 that is in contact with the cathode gas diffusion layer 14, a serpentine-shaped cathode gas flow path 32 including, for example, a plurality of U-shaped folded portions and a plurality of linear portions in a plan view is provided. ing. The straight line portion of the cathode gas flow path 32 extends in a direction perpendicular to the plane of FIG. 2A. However, such a cathode gas flow path 32 is an example, and is not limited to this example. For example, the cathode gas flow path may be constituted by a plurality of linear flow paths.

  The main surface of the anode separator 17 that is in contact with the anode fluid diffusion layer 15 is provided with, for example, a serpentine anode fluid flow path 33 including a plurality of U-shaped folded portions and a plurality of straight portions in plan view. ing. The straight line portion of the anode fluid flow path 33 extends in a direction perpendicular to the paper surface of FIG. 3A. However, such an anode fluid flow path 33 is an example, and is not limited to this example. For example, the anode fluid flow path may be constituted by a plurality of linear flow paths.

  Further, between the conductive cathode separator 16 and the anode separator 17, an annular and plate-shaped insulator 21 provided so as to surround the periphery of the MEA is sandwiched. This prevents a short circuit between the cathode separator 16 and the anode separator 17.

  Here, the electrochemical hydrogen pump 100 includes a first end plate and a second end plate provided on both ends of the hydrogen pump unit 100A in the stacking direction, and a hydrogen pump unit 100A, a first end plate and a second end plate. And a fastener 25 for fastening in the stacking direction.

  In the example shown in FIGS. 2A and 3A, the cathode end plate 24C and the anode end plate 24A correspond to the first end plate and the second end plate, respectively. That is, the anode end plate 24A is an end plate provided on the anode separator 17 located at one end in the stacking direction in which the members of the hydrogen pump unit 100A are stacked. The cathode end plate 24C is an end plate provided on the cathode separator 16 located at the other end in the stacking direction in which the members of the hydrogen pump unit 100A are stacked.

  The fastener 25 may have any configuration as long as the hydrogen pump unit 100A, the cathode end plate 24C, and the anode end plate 24A can be fastened in the stacking direction.

  For example, the fastener 25 may include a bolt and a nut with a disc spring.

  At this time, the bolts of the fastener 25 may be configured to penetrate only the anode end plate 24A and the cathode end plate 24C. However, in the electrochemical hydrogen pump 100 of the present embodiment, the bolts have three stages. Each member of the hydrogen pump unit 100A, the cathode power supply plate 22C, the cathode insulation plate 23C, the anode power supply plate 22A, the anode insulation plate 23A, the anode end plate 24A, and the cathode end plate 24C are penetrated. Then, the end face of the cathode separator 16 located at the other end in the above-described laminating direction, and the end face of the anode separator 17 located at one end in the above-described laminating direction are respectively referred to as a cathode power supply plate 22C, a cathode insulating plate 23C and A desired fastening pressure is applied to the hydrogen pump unit 100A by the fastener 25 so as to be sandwiched between the cathode end plate 24C and the anode end plate 24A via the anode power supply plate 22A and the anode insulating plate 23A, respectively.

  As described above, in the electrochemical hydrogen pump 100 of the present embodiment, the three-stage hydrogen pump unit 100A is appropriately held in the stacked state by the fastening pressure of the fastener 25 in the above-described stacking direction, and the electrochemical hydrogen pump Since the bolts of the fastener 25 penetrate the 100 members, the movement of these members in the in-plane direction can be appropriately suppressed.

  Here, in the electrochemical hydrogen pump 100 of the present embodiment, the cathode gas flow paths 32 through which the cathode gas flowing out from the respective cathode gas diffusion layers 14 of the hydrogen pump unit 100A are connected. Hereinafter, a configuration in which the cathode gas flow paths 32 communicate with each other will be described with reference to the drawings.

First, as shown in FIG. 2A, the cathode gas deriving manifold 28 includes a through-hole provided in each member of the three-stage hydrogen pump unit 100A and the cathode end plate 24C, and a non-through hole provided in the anode end plate 24A. It is constituted by a series of holes. The cathode end plate 24C is provided with a cathode gas outlet path 26. The cathode gas outlet path 26 may be configured by a pipe through which hydrogen (H ₂ ) discharged from the cathode CA flows. The cathode gas outlet path 26 is in communication with the cathode gas outlet manifold 28 described above.

  Further, the cathode gas outlet manifold 28 is in communication with one end of each cathode gas flow path 32 of the hydrogen pump unit 100A via each of the cathode gas passages 34. As a result, the hydrogen that has passed through each of the cathode gas passages 32 and the cathode gas passages 34 of the hydrogen pump unit 100A is joined at the cathode gas outlet manifold 28. Then, the merged hydrogen is led to the cathode gas outlet path 26.

  Thus, the respective cathode gas passages 32 of the hydrogen pump unit 100A communicate with each other via the respective cathode gas passages 34 and the cathode gas outlet manifold 28 of the hydrogen pump unit 100A.

  An O-ring is provided between the cathode separator 16 and the anode separator 17, between the cathode separator 16 and the cathode power supply plate 22C, and between the anode separator 17 and the anode power supply plate 22A so as to surround the cathode gas outlet manifold 28 in plan view. The cathode gas outlet manifold 28 is appropriately sealed by the seal member 40.

  As shown in FIG. 3A, an anode fluid introduction path 29 is provided in the anode end plate 24A. The anode fluid introduction path 29 may be configured by a pipe through which the anode fluid supplied to the anode AN flows. The anode fluid introduction path 29 is in communication with the cylindrical anode fluid introduction manifold 27. The anode fluid introduction manifold 27 is configured by a series of members of the three-stage hydrogen pump unit 100A and through holes provided in the anode end plate 24A.

  Further, the anode fluid introduction manifold 27 communicates with one end of each anode fluid flow path 33 of the hydrogen pump unit 100A via each of the first anode fluid passages 35. Thereby, the anode fluid supplied from the anode fluid introduction passage 29 to the anode fluid introduction manifold 27 is distributed to each of the hydrogen pump units 100A through the respective first anode fluid passages 35 of the hydrogen pump unit 100A. The anode fluid is supplied from the anode fluid diffusion layer 15 to the anode catalyst layer 13 while the distributed anode fluid passes through the anode fluid channel 33.

  As shown in FIG. 3A, an anode fluid outlet path 31 is provided in the anode end plate 24A. The anode fluid outlet path 31 may be configured by a pipe through which the anode fluid discharged from the anode AN flows. The anode fluid outlet path 31 communicates with the cylindrical anode fluid outlet manifold 30. The anode fluid outlet manifold 30 is configured by a series of members of the three-stage hydrogen pump unit 100A and through holes provided in the anode end plate 24A.

  In addition, the anode fluid outlet manifold 30 communicates with the other end of each anode fluid passage 33 of the hydrogen pump unit 100A via each of the second anode fluid passages 36. As a result, the anode fluid that has passed through each anode fluid passage 33 of the hydrogen pump unit 100A is supplied to the anode fluid outlet manifold 30 through each of the second anode fluid passages 36, where they are merged. Then, the merged anode fluid is guided to the anode fluid outlet path 31.

  Between the cathode separator 16 and the anode separator 17, between the cathode separator 16 and the cathode power supply plate 22 </ b> C, and between the anode separator 17 and the anode power supply plate 22 </ b> A, an anode fluid introduction manifold 27 and an anode fluid outlet manifold 30 are provided in plan view. An annular seal member 40 such as an O-ring is provided so as to surround it, and the anode fluid introduction manifold 27 and the anode fluid outlet manifold 30 are appropriately sealed by the seal member 40.

  As shown in FIGS. 2A and 3A, the electrochemical hydrogen pump 100 includes a voltage applicator 102.

  The voltage applicator 102 is a device that applies a voltage between the anode catalyst layer 13 and the cathode catalyst layer 12. Specifically, a high potential of the voltage applicator 102 is applied to the anode catalyst layer 13, and a low potential of the voltage applicator 102 is applied to the cathode catalyst layer 12. The voltage applicator 102 may have any configuration as long as a voltage can be applied between the anode catalyst layer 13 and the cathode catalyst layer 12. For example, the voltage applicator 102 may be a device that adjusts a voltage applied between the anode catalyst layer 13 and the cathode catalyst layer 12. At this time, the voltage applicator 102 includes a DC / DC converter when connected to a DC power supply such as a battery, a solar cell, or a fuel cell, and includes an AC / DC converter when connected to an AC power supply such as a commercial power supply. / DC converter.

  Further, the voltage applicator 102 controls the voltage applied between the anode catalyst layer 13 and the cathode catalyst layer 12 such that the power supplied to the hydrogen pump unit 100A becomes a predetermined set value. It may be a power type power supply in which the current flowing between the catalyst layers 12 is adjusted.

  2A and 3A, the terminal on the low potential side of the voltage applicator 102 is connected to the cathode power supply plate 22C, and the terminal on the high potential side of the voltage applicator 102 is connected to the anode power supply plate 22A. Have been. The cathode power supply plate 22C is in electrical contact with the cathode separator 16 located at the other end in the lamination direction, and the anode power supply plate 22A is in contact with the anode separator 17 located at one end in the lamination direction. There is electrical contact.

  Here, although not shown in FIGS. 1, 2A, and 3A, members and devices necessary for the hydrogen boosting operation of the electrochemical hydrogen pump 100 of the hydrogen system 200 of the present embodiment are appropriately provided.

  For example, the hydrogen system 200 is provided with, for example, a temperature detector that detects the temperature of the electrochemical hydrogen pump 100, a pressure detector that detects the pressure P of hydrogen boosted by the cathode CA of the electrochemical hydrogen pump 100, and the like. ing.

  In the hydrogen system 200, valves for opening and closing the anode fluid introduction path 29, the anode fluid exit path 31, and the cathode gas exit path 26 are provided at appropriate places.

  Further, the hydrogen system 200 is provided with a water level detector for detecting the water level H in the gas-liquid separator 110.

When the anode fluid is hydrogen (H ₂ ), the hydrogen system 200 includes a highly humidified state of hydrogen (H ₂ ) discharged from the anode AN through the anode fluid outlet passage 31 and an external fluid through the anode fluid introduction passage 29. A dew point adjuster (for example, a humidifier) that adjusts the dew point of a mixed gas in which hydrogen (H ₂ ) in a low humidified state supplied from the hydrogen supply source is mixed may be provided. At this time, the hydrogen of the external hydrogen supply source may be generated by, for example, a water electrolysis device.

  Further, the configuration of the electrochemical hydrogen pump 100 and the configuration of the hydrogen system 200 described above are merely examples, and are not limited to this example.

For example, when the anode fluid is hydrogen (H ₂ ), the electrochemical hydrogen pump 100 supplies the hydrogen supplied to the anode AN through the anode fluid introduction manifold 27 without providing the anode fluid outlet manifold 30 and the anode fluid outlet path 31. A dead end structure in which the pressure is boosted by the cathode CA may be employed.

When the anode fluid is hydrogen (H ₂ ), the hydrogen (H ₂ ) flows through the anode fluid passage 33 and the cathode gas passage 32, but the hydrogen concentration may not be 100%. It suffices if a hydrogen-containing gas containing hydrogen flows.

[motion]
FIG. 4 is a flowchart illustrating an example of the operation of the hydrogen system according to the first embodiment.

In the following operation, hydrogen (H ₂ ) is supplied to the anode AN of the electrochemical hydrogen pump 100 as an anode fluid. The following operation may be performed, for example, by the arithmetic circuit of the controller 50 reading a control program from the storage circuit of the controller 50. However, it is not always essential that the controller 50 performs the following operations. The operator may perform a part of the operation.

  In step S1, low-pressure hydrogen is supplied to the anode AN of the electrochemical hydrogen pump 100, and the voltage of the voltage applicator 102 is applied to the electrochemical hydrogen pump 100. Is started. At this time, the first valve 120 for discharging the water in the tank 110A of the gas-liquid separator 110 is closed.

  Specifically, in the anode catalyst layer 13 of the anode AN, hydrogen molecules are separated into hydrogen ions (protons) and electrons by an oxidation reaction (formula (1)). Protons travel through the electrolyte membrane 11 and move to the cathode catalyst layer 12. The electrons move to the cathode catalyst layer 12 through the voltage applicator 102.

  Then, in the cathode catalyst layer 12, hydrogen molecules are generated again by the reduction reaction (formula (2)). It is known that a predetermined amount of water moves from the anode AN to the cathode CA together with the protons as electroosmotic water when the protons conduct in the electrolyte membrane 11.

  At this time, the pressure generated in the cathode CA can be increased by increasing the pressure loss in the hydrogen outlet path using a flow controller (not shown). In addition, as the hydrogen derivation path, for example, the cathode gas derivation path 26 in FIGS. 1 and 2A can be cited. In addition, examples of the flow regulator include a back pressure valve, a regulating valve, and the like provided in the hydrogen outlet path.

Anode: _{H 2} (low ^{pressure) → 2H + + 2e - ···} (1)
Cathode: 2H ⁺ + 2e ⁻ → H ₂ (high pressure) (2)
In this manner, in the electrochemical hydrogen pump 100, the voltage supplied to the anode AN is boosted at the cathode CA by applying a voltage with the voltage applicator 102.

  Then, the hydrogen discharged from the cathode CA to the cathode gas outlet path 26 is sent to the gas-liquid separator 110 through the cathode gas outlet path 26, and the water discharged along with the hydrogen is separated by the gas-liquid separator 110. Is done. Then, as the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 proceeds, the amount of liquid water present in the gas-liquid separator 110 increases.

  Therefore, in the hydrogen system 200 of the present embodiment, the operation of draining water existing in the gas-liquid separator 110 is performed as described below.

  First, in step S2, it is determined whether or not the pressure P of hydrogen boosted at the cathode CA is equal to or lower than the first pressure P1. Here, the hydrogen pressure P in step S2 is detected by a pressure detector (not shown) provided at an appropriate position in the hydrogen system 200. Further, the first pressure P1 in step S2 is a predetermined pressure which is smaller than the pressure increase upper limit PL of the electrochemical hydrogen pump 100. As described above, the first pressure P1 may be a predetermined pressure at which the concentration of dissolved hydrogen in water in the gas-liquid separator 110 does not increase.

  When the hydrogen pressure P is equal to or lower than the first pressure P1 (P ≦ P1) in step S2, the first valve 120 is opened in step S3. Thereby, the water in the tank 110A of the gas-liquid separator 110 is discharged out of the tank 110A. Thereafter, in step S1, the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 is continued.

  After opening the first valve 120 in step S3, the first valve 120 is closed in a timely manner. At this time, the opening time of the first valve 120 depends on the amount of water in the gas-liquid separator 110, the pressure P of hydrogen in the gas-liquid separator 110, the flow path resistance of a drain pipe connected to the lower wall of the tank 110A, and the like. An appropriate time may be set based on this.

On the other hand, in step S2, when the hydrogen pressure P is higher than the first pressure P1 (P> P1), the first valve 120 is not opened. That is, the open / close state of the first valve 120 remains closed.
Thereafter, in step S1, the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 is continued.

  As described above, the hydrogen system 200 of the present embodiment can improve the efficiency of the electrochemical hydrogen pump 100 at the time of the hydrogen pressurizing operation as compared with the related art.

  Specifically, the higher the pressure P of the hydrogen boosted at the cathode CA of the electrochemical hydrogen pump 100, the higher the dissolved hydrogen concentration in the water in the gas-liquid separator 110. Therefore, in the hydrogen system 200 of the present embodiment, the water in the gas-liquid separator 110 is discharged to the outside at an appropriate timing when the pressure P of the hydrogen boosted at the cathode CA is equal to or lower than the first pressure P1. Of the first valve 120 is opened. Thereby, the hydrogen system 200 of the present embodiment allows the water in the gas-liquid separator 110 to be discharged to the outside as compared with the case where the first valve 120 is opened when the hydrogen pressure P exceeds the first pressure P1. Since the concentration of dissolved hydrogen in the water in the gas-liquid separator 110 at the time of discharging is low, the amount of hydrogen discharged to the outside of the gas-liquid separator 110 can be reduced. As a result, in the hydrogen system 200 of the present embodiment, the efficiency of the electrochemical hydrogen pump 100 at the time of increasing the pressure of hydrogen is improved.

  Further, the hydrogen system 200 of the present embodiment appropriately discharges the water present in the gas-liquid separator 110 to the outside before the pressure P of the hydrogen pressurized at the cathode CA reaches the first pressure P1. Accordingly, in the gas-liquid separator 110, the amount of water in a state where the dissolved hydrogen concentration is increased can be reduced. As a result, in the hydrogen system 200 of the present embodiment, the efficiency of the electrochemical hydrogen pump 100 at the time of increasing the pressure of hydrogen is improved.

(First embodiment)
The hydrogen system 200 of the present embodiment is the same as the hydrogen system 200 of the first embodiment except for the control contents of the controller 50 described below.

  When the pressure value of hydrogen generated at the cathode CA by the electrochemical hydrogen pump 100 is increasing, the controller 50 sets the pressure P of the hydrogen increased at the cathode CA at least once at a pressure equal to or lower than the first pressure P1. The first valve 120 is opened. For example, when the boosted value of the hydrogen generated at the cathode CA by the electrochemical hydrogen pump 100 is increasing, the operation from step S1 to step S3 in FIG. 4 may be performed only once, or It may be performed multiple times at each time interval. That is, when the pressure P of the hydrogen boosted at the cathode CA is equal to or lower than the first pressure P1, the first valve 120 is opened at least once in step S3 of FIG.

  The operation and effect of the hydrogen system 200 of the present embodiment are the same as the operation and effect of the hydrogen system 200 of the first embodiment, and a description thereof will be omitted.

  The hydrogen system 200 of the present embodiment may be the same as the hydrogen system 200 of the first embodiment, except for the features described above.

(Second embodiment)
The hydrogen system 200 of the present embodiment is the same as the hydrogen system 200 of the first embodiment except for the control contents of the controller 50 described below.

  The controller 50 opens the first valve 120 regardless of the water level H in the gas-liquid separator 110 when the pressure P of the hydrogen boosted at the cathode CA is equal to or lower than the first pressure P1. For example, when the pressure P of the hydrogen pressurized at the cathode CA is equal to or lower than the first pressure P1, the first valve 120 is opened regardless of the water level H in the gas-liquid separator 110 in step S3 of FIG. You.

  As described above, the hydrogen system 200 according to the present embodiment performs the gas-liquid separation regardless of the water level H in the gas-liquid separator 110 when the pressure P of the hydrogen boosted at the cathode CA is equal to or lower than the first pressure P1. By opening the first valve 120 for discharging the water in the vessel 110, the concentration of dissolved hydrogen can be reduced at a stage where the hydrogen pressure P does not become high without waiting for the water level H in the gas-liquid separator 110 to rise. Low-concentration water can be discharged out of the gas-liquid separator 110.

  Except for the features described above, the hydrogen system 200 of this example may be the same as the hydrogen system 200 of the first embodiment or the first example of the first embodiment.

(Modification)
The hydrogen system 200 of the present modified example is the same as the hydrogen system 200 of the first embodiment except for the control contents of the controller 50 described below.

  The controller 50 determines that the pressure P of the hydrogen boosted at the cathode CA is equal to or lower than the first pressure P1, and the water level H in the gas-liquid separator 110 is equal to or higher than the first water level H1 set as the reference water level. At one time, the first valve 120 for discharging the water in the gas-liquid separator 110 is opened.

FIG. 5 is a flowchart illustrating an example of the operation of the hydrogen system according to the modification of the first embodiment. In the following operation, hydrogen (H ₂ ) is supplied to the anode AN of the electrochemical hydrogen pump 100 as an anode fluid. The following operation may be performed, for example, by the arithmetic circuit of the controller 50 reading a control program from the storage circuit of the controller 50. However, it is not always essential that the controller 50 perform the following operations. The operator may perform a part of the operation.

  Steps S1, S2, and S3 in FIG. 5 are the same as steps S1, S2, and S3 in FIG. 4, respectively, and thus detailed description will be omitted.

  When the hydrogen pressure P is equal to or lower than the first pressure P1 (P ≦ P1) in step S2, the process proceeds to the next determination step S4, and in step S4, the water level H in the gas-liquid separator 110 is reduced to the first level. It is determined whether the water level is equal to or higher than H1.

  If the water level H in the gas-liquid separator 110 is equal to or higher than the first water level H1 (H ≧ H1) in step S4, the first valve for discharging the water in the gas-liquid separator 110 in step S3. 120 is opened. Thereby, the water in the tank 110A of the gas-liquid separator 110 is discharged out of the tank 110A. Thereafter, in step S1, the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 is continued.

  On the other hand, in step S4, when the water level H in the gas-liquid separator 110 is lower than the first water level H1 (H <H1), the first valve 120 is not opened. That is, the open / close state of the first valve 120 remains closed. Thereafter, in step S1, the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 is continued.

  However, this operation is an exemplification, and is not limited to this example. Even when the water level H in the gas-liquid separator 110 is lower than the first water level H1 (H <H1), if the hydrogen pressure P is equal to or lower than the first pressure P1 (P ≦ P1), the first valve 120 is turned off. You can open it.

  Here, when the hydrogen pressure P is higher than the first pressure P1 (P> P1), even if the water level H in the gas-liquid separator 110 is equal to or higher than the first water level H1, Valve 120 is not opened.

  Although not shown in FIG. 5, when the hydrogen pressure P is higher than the first pressure P1 (P> P1), the water level H in the gas-liquid separator 110 becomes higher than the first water level H1. Then, the hydrogen boosting operation of the electrochemical hydrogen pump 100 may be stopped. The reference water level for stopping the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 may be a second water level H2 higher than the first water level H1.

  As described above, in the hydrogen system 200 of the present modification, the pressure P of hydrogen boosted at the cathode CA is equal to or lower than the first pressure P1, and the water level H in the gas-liquid separator 110 is equal to or higher than the first water level H1. At a certain time, the water in the gas-liquid separator 110 can be discharged to the outside.

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

(2nd Embodiment)
[Device configuration]
FIG. 6 is a diagram illustrating an example of the hydrogen system according to the second embodiment.

  In the example shown in FIG. 6, the hydrogen system 200 includes an electrochemical hydrogen pump 100, a gas-liquid separator 110, a first valve 120, a second valve 130, a bypass valve 140, and a controller 50. .

  Here, the electrochemical hydrogen pump 100, the gas-liquid separator 110, and the first valve 120 are the same as those of the hydrogen system 200 of the first embodiment, and a description thereof will be omitted.

  The second valve 130 is a valve provided in a flow path through which hydrogen discharged from the cathode CA of the electrochemical hydrogen pump 100 flows into the gas-liquid separator 110. The second valve 130 may have any configuration as long as it can open and close the flow path through which the hydrogen flowing into the gas-liquid separator 110 flows.

  For example, in the hydrogen system 200 shown in FIG. 1, the cathode gas outlet path 26 includes an upstream path 26A extending from the cathode CA to a hydrogen inlet provided on the upper wall of the tank 110A of the gas-liquid separator 110, and an air path 26A. A downstream path 26B extending from a hydrogen outlet provided on the upper wall of the tank 110A of the liquid separator 110 to the outside, and a bypass path connecting to the upstream path 26A and the downstream path 26B and bypassing the gas-liquid separator 110. 26C.

  Then, the second valve 130 is provided with a valve 130A provided on the upstream path 26A downstream of the connection point between the bypass path 26C and the upstream path 26A, and on the downstream side upstream of the connection point between the bypass path 26C and the downstream path 26B. A valve 130B provided in the passage 26B. A bypass valve 140 is provided in the bypass path 26C.

  In addition, as the valve 130A, the valve 130B, and the bypass valve 140, for example, an electromagnetic valve or the like can be used.

  When the pressure P of the hydrogen boosted at the cathode CA is higher than the first pressure P1 and equal to or higher than the second pressure P2 which is equal to or lower than the upper limit PL of the electrochemical hydrogen pump 100, the controller 50 sets The two valves 130 are closed. For example, in the example shown in FIG. 6, the valves 130A and 130B of the second valve 130 are closed. At this time, the bypass valve 140 is opened. Thereby, the hydrogen discharged from the cathode CA is sent from the upstream path 26A to the downstream path 26B without passing through the gas-liquid separator 110.

  Conversely, the controller 50 opens the second valve 130 when the pressure P of the hydrogen boosted at the cathode CA is lower than the second pressure P2. For example, in the example shown in FIG. 6, the valves 130A and 130B of the second valve 130 are opened. At this time, the bypass valve 140 is closed. As a result, the hydrogen discharged from the cathode CA passes through the tank 110A of the gas-liquid separator 110. Therefore, in the gas-liquid separator 110, hydrogen discharged from the cathode CA to the cathode gas outlet path 26 and moisture discharged along with the hydrogen are separated.

  The second pressure P2 may be set to any pressure as long as it is higher than the first pressure P1 and lower than the upper limit PL of the electrochemical hydrogen pump 100. For example, as the pressure P of the hydrogen boosted at the cathode CA of the electrochemical hydrogen pump 100 increases, the concentration of dissolved hydrogen in the water in the gas-liquid separator 110 increases. Therefore, the second pressure P2 may be, for example, a predetermined pressure at which the concentration of dissolved hydrogen in water in the gas-liquid separator 110 does not exceed an allowable value.

  As an example, the pressure increase upper limit PL of the electrochemical hydrogen pump 100 may be about 40 Mpa, the first pressure P1 may be about 30 MPa, and the second pressure P2 may be about 35 MPa. In addition, these pressure values are examples, and are not limited to the present example. For example, here, the second pressure P2 is set to a value larger than the first pressure P1, but both may be the same pressure.

[motion]
FIG. 7 is a flowchart illustrating an example of the operation of the hydrogen system according to the second embodiment. In the following operation, hydrogen (H ₂ ) is supplied to the anode AN of the electrochemical hydrogen pump 100 as an anode fluid. The following operation may be performed, for example, by the arithmetic circuit of the controller 50 reading a control program from the storage circuit of the controller 50. However, it is not always essential that the controller 50 performs the following operations. The operator may perform a part of the operation.

  Step S1, step S2, and step S3 in FIG. 7 are the same as step S1, step S2, and step S3 in FIG. 4, respectively, and thus detailed description will be omitted.

  When the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 of the hydrogen system 200 is started, the first valve 120 for discharging the water in the tank 110A of the gas-liquid separator 110 is closed. The valves 130A and 130B of the second valve 130 provided in the flow path through which the hydrogen flowing into the gas-liquid separator 110 flows are open. Further, the bypass valve 140 is closed.

  In step S2, when the pressure P of the hydrogen boosted at the cathode CA is higher than the first pressure P1 (P> P1), the process proceeds to the next determination step S5. It is determined whether the pressure is equal to or higher than the pressure P2. Here, the hydrogen pressure P in step S5 is detected by a pressure detector (not shown) provided at an appropriate position in the hydrogen system 200. The second pressure P2 in step S5 is a predetermined pressure that is higher than the first pressure P1 and lower than the upper limit PL of the electrochemical hydrogen pump 100. As described above, the second pressure P2 may be a predetermined pressure at which the concentration of dissolved hydrogen in water in the gas-liquid separator 110 does not become excessively high.

  In step S5, when the hydrogen pressure P is equal to or higher than the second pressure P2 (P ≧ P2), the valves 130A and 130B of the second valve 130 are closed. At this time, the bypass valve 140 is opened. Thereby, the hydrogen discharged from the cathode CA is supplied to the downstream path 26B of the cathode gas outlet path 26 without passing through the gas-liquid separator 110. Thereafter, in step S1, the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 is continued.

  On the other hand, when the hydrogen pressure P is lower than the second pressure P2 (P <P2) in step S5, the valves 130A and 130B of the second valve 130 are not closed. That is, the open / close state of the valves 130A and 130B of the second valve 130 remains open. At this time, the open / close state of the bypass valve 140 remains closed. As a result, in the gas-liquid separator 110, hydrogen discharged from the cathode CA to the cathode gas outlet path 26 and water discharged together with the hydrogen are separated. Thereafter, in step S1, the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 is continued.

  As described above, the hydrogen system 200 of the present embodiment can improve the efficiency of the electrochemical hydrogen pump 100 during the hydrogen pressurization operation as compared with the conventional case.

  Specifically, the higher the pressure of hydrogen boosted at the cathode CA of the electrochemical hydrogen pump 100, the higher the concentration of dissolved hydrogen in the water in the gas-liquid separator 110. Therefore, in the hydrogen system 200 of the present embodiment, the second pressure at which the pressure P of the hydrogen boosted at the cathode CA is higher than the first pressure P1 and equal to or less than the boosting upper limit PL of the electrochemical hydrogen pump 100. When the pressure is equal to or higher than P2, the valves 130A and 130B of the second valve 130 provided in the flow path through which the hydrogen flowing into the gas-liquid separator 110 flows are closed, thereby dissolving in the water present in the gas-liquid separator 110. An increase in hydrogen can be suppressed. As a result, in the hydrogen system 200 of the present embodiment, the efficiency of the electrochemical hydrogen pump 100 at the time of increasing the pressure of hydrogen is improved.

  Here, when the pressure P of the hydrogen pressurized at the cathode CA rises, water is generated at the cathode by condensing the amount of water vapor contained in the hydrogen. Then, a part of the water present in the cathode CA is pushed back from the cathode CA to the anode AN through the electrolyte membrane 11 due to a pressure difference between the cathode CA and the anode AN. As a result, as the pressure P of the hydrogen pressurized at the cathode CA becomes higher, the moisture contained in the hydrogen discharged from the cathode CA to the cathode gas outlet path 26 decreases. Therefore, when the pressure P of the hydrogen pressurized at the cathode CA is equal to or higher than the second pressure P2, the amount of water contained in the hydrogen discharged from the cathode CA to the cathode gas outlet path 26 is very small. Even if the valves 130A and 130B of the second valve 130 are closed so that the pressurized hydrogen does not pass through the gas-liquid separator 110, the water contained in the hydrogen can be appropriately treated.

  For example, even when the water contained in the hydrogen pressurized at the cathode CA is adsorbed and removed by the adsorbent of the appropriate water remover, the deterioration of the water adsorption performance of the adsorbent can be appropriately reduced. The details of such a water remover will be described in a fourth embodiment.

  Except for the features described above, the hydrogen system 200 according to the present embodiment is different from the hydrogen system 200 according to the first embodiment, any one of the first to second examples of the first embodiment, and the modification of the first embodiment. The same may be applied.

(Third embodiment)
The hydrogen system 200 of the present embodiment is the same as the hydrogen system 200 of the first embodiment, except for the control contents of the controller 50 described below.

  When the pressure P of the hydrogen pressurized at the cathode CA is equal to or lower than the first pressure P1 and equal to or higher than the third pressure P3, the controller 50 controls the first valve for discharging the water in the gas-liquid separator 110. Release 120.

  Note that the third pressure P3 may be set to any pressure as long as it is lower than the first pressure P1 which is smaller than the pressure increase upper limit PL of the electrochemical hydrogen pump 100. For example, when the pressure P of hydrogen boosted at the cathode CA increases, water is generated at the cathode CA by condensing the amount of water vapor contained in the hydrogen. Then, a part of the water present in the cathode CA is pushed back from the cathode CA to the anode AN through the electrolyte membrane 11 due to a pressure difference between the cathode CA and the anode AN. As a result, as the pressure P of the hydrogen pressurized at the cathode CA becomes higher, the moisture contained in the hydrogen discharged from the cathode CA to the cathode gas outlet path 26 decreases. Therefore, the third pressure P3 may be, for example, a predetermined pressure at which water contained in hydrogen discharged from the cathode CA to the cathode gas outlet path 26 decreases.

  As an example, the upper limit PL of the electrochemical hydrogen pump 100 may be about 40 MPa, the first pressure P1 may be about 30 MPa, and the third pressure P3 may be about 10 MPa. In addition, these pressure values are examples, and are not limited to the present example. For example, the third pressure P3 may be set to an appropriate value based on the characteristics of the electrolyte membrane 11 and the like.

FIG. 8 is a flowchart illustrating an example of the operation of the hydrogen system according to the third embodiment. In the following operation, hydrogen (H ₂ ) is supplied to the anode AN of the electrochemical hydrogen pump 100 as an anode fluid. The following operation may be performed, for example, by the arithmetic circuit of the controller 50 reading a control program from the storage circuit of the controller 50. However, it is not always essential that the controller 50 performs the following operations. The operator may perform a part of the operation.

  Steps S1, S2, and S3 in FIG. 8 are the same as steps S1, S2, and S3 in FIG. 4, respectively, and thus a detailed description thereof will be omitted.

  When the hydrogen pressure P is equal to or lower than the first pressure P1 (P ≦ P1) in step S2, the process proceeds to the next determination step S7, and in step S7, is the hydrogen pressure P equal to or higher than the third pressure P3? It is determined whether or not.

  When the pressure P of the hydrogen is equal to or higher than the third pressure P3 in step S7 (P ≧ P3), the first valve 120 for discharging the water in the gas-liquid separator 110 is opened in step S3. Thereby, the water in the tank 110A of the gas-liquid separator 110 is discharged out of the tank 110A. Thereafter, in step S1, the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 is continued.

  On the other hand, in step S7, when the hydrogen pressure P is lower than the third pressure P3 (P <P3), the first valve 120 is not opened. That is, the open / close state of the first valve 120 remains closed. Thereafter, in step S1, the hydrogen pressurizing operation of the electrochemical hydrogen pump 100 is continued.

  However, this operation is an exemplification, and is not limited to this example. Even when the hydrogen pressure P is lower than the third pressure P3 (P <P3), when the hydrogen pressure P is equal to or lower than the first pressure P1 (P ≦ P1), for example, the water level in the gas-liquid separator 110 is When it becomes higher, the first valve 120 may be opened.

  As described above, the hydrogen system 200 according to the present embodiment is configured such that the pressure P of the hydrogen boosted at the cathode CA is equal to or lower than the first pressure P1 and equal to or higher than the third pressure P3. Water can be discharged to the outside.

  Specifically, when the pressure P of the hydrogen pressurized at the cathode CA is equal to or higher than the third pressure P3, the moisture contained in the hydrogen discharged from the cathode CA to the cathode gas outlet path 26 decreases. Therefore, when the pressure value of hydrogen generated at the cathode CA by the electrochemical hydrogen pump 100 is increasing, the timing at which the hydrogen pressure P becomes the third pressure P3 and the time when the hydrogen pressure P becomes the first pressure P1 Once the water collected in the gas-liquid separator 110 is drained to the outside within the time between the timings of the above and the following, it becomes difficult for water having a high concentration of dissolved hydrogen to accumulate in the gas-liquid separator 110.

  Except for the features described above, the hydrogen system 200 of the present embodiment is any one of the first embodiment, the first to second examples of the first embodiment, a modification of the first embodiment, and the second embodiment. May be the same as the hydrogen system 200 of FIG.

(Fourth embodiment)
FIG. 9 is a diagram illustrating an example of the hydrogen system according to the fourth embodiment.

  In the example shown in FIG. 9, the hydrogen system 200 includes an electrochemical hydrogen pump 100, a gas-liquid separator 110, a first valve 120, a moisture remover 150, and a controller 50.

  Here, the electrochemical hydrogen pump 100, the gas-liquid separator 110, the first valve 120, and the controller 50 are the same as those of the hydrogen system 200 of the first embodiment, and thus the description is omitted.

  The water remover 150 is an apparatus that is provided in a flow path between the gas-liquid separator 110 and a hydrogen utilization device (not shown), and includes an adsorbent that removes moisture accompanying hydrogen. Specifically, the water remover 150 is provided in the cathode gas outlet path 26 extending from the hydrogen outlet provided on the upper wall of the tank 110A of the gas-liquid separator 110 to the hydrogen utilization equipment.

  The above-mentioned hydrogen utilization device may be any device as long as it is a device for utilizing hydrogen. Examples of the hydrogen utilization device include a hydrogen storage device that temporarily stores hydrogen, a fuel cell that generates power using hydrogen, and the like.

  The adsorbent of the water remover 150 may be made of any material that adsorbs and removes moisture such as water vapor in hydrogen. Examples of the material of the adsorbent include porous materials such as zeolite and silica gel. While such adsorbents are dry, moisture is adsorbed, but eventually the adsorbent's moisture adsorption performance decreases due to the adsorption of moisture, so it is necessary to replace or regenerate the adsorbent. Becomes

  As described above, the hydrogen system 200 of the present embodiment can adsorb and remove water contained in hydrogen such as water vapor that cannot be separated by the gas-liquid separator 110 by the adsorbent of the water remover 150. Thereby, dry hydrogen can be supplied to the above-mentioned hydrogen utilization equipment.

  Except for the features described above, the hydrogen system 200 of the present embodiment has the first embodiment, the first to second examples of the first embodiment, the modifications of the first embodiment, the second embodiment, and the third embodiment. It may be similar to any of the hydrogen systems 200 of the embodiments.

  Note that the first embodiment, the first example-second example of the first embodiment, the modified example of the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment exclude each other. Unless otherwise stated, they may be combined with each other.

  From the above description, many modifications and other embodiments of the present disclosure are obvious to one skilled in the art. Therefore, the above description is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the present disclosure. Operational conditions, compositions, structures and / or functions may be substantially changed without departing from the spirit of the present disclosure.

  One embodiment of the present disclosure can be used, for example, in a hydrogen system that can improve the efficiency of an electrochemical hydrogen pump during a hydrogen pressure increasing operation as compared with the related art.

11: electrolyte membrane 12: cathode catalyst layer 13: anode catalyst layer 14: cathode gas diffusion layer 15: anode fluid diffusion layer 16: cathode separator 17: anode separator 21: insulator 22A: anode power supply plate 22C: cathode power supply plate 23A: Anode insulating plate 23C: Cathode insulating plate 24A: Anode end plate 24C: Cathode end plate 25: Fastener 26: Cathode gas outlet path 26A: Upstream path 26B: Downstream path 26C: Bypass path 27: Anode fluid introduction manifold 28: Cathode gas Derivation manifold 29: Anode fluid introduction path 30: Anode fluid derivation manifold 31: Anode fluid departure path 32: Cathode gas flow path 33: Anode fluid flow path 34: Cathode gas passage 35: First anode fluid passage 36: No. Anode fluid passage 40: seal member 42: seal member 43: seal member 50: controller 100: electrochemical hydrogen pump 100A: hydrogen pump unit 102: voltage applicator 110: gas-liquid separator 110A: tank 120: first valve 130: second valve 130A: valve 130B: valve 140: bypass valve 150: moisture remover 200: hydrogen system AN: anode CA: cathode

Claims (6)

An electrochemical hydrogen pump in which protons extracted from the anode fluid at the anode move through the electrolyte membrane, and pressurized hydrogen is generated at the cathode;
A gas-liquid separator for separating hydrogen discharged from the cathode and water discharged along with the discharged hydrogen,
A first valve for discharging water in the gas-liquid separator;
A controller for opening the first valve when the pressure of the boosted hydrogen is equal to or lower than a first pressure smaller than an upper limit pressure of the electrochemical hydrogen pump.   The controller is configured to, when the pressure value of the hydrogen generated at the cathode by the electrochemical hydrogen pump is rising, increase the pressure of the boosted hydrogen at least once below the first pressure, The hydrogen system according to claim 1, wherein the valve is opened.   3. The controller according to claim 1, wherein the controller opens the first valve regardless of a water level in the gas-liquid separator when the pressure of the boosted hydrogen is equal to or lower than the first pressure. 4. Hydrogen system.   2. The controller according to claim 1, wherein the controller opens the first valve when a pressure of the boosted hydrogen is equal to or lower than the first pressure and a water level in the gas-liquid separator is equal to or higher than a reference water level. 3. 3. The hydrogen system according to 2. A second valve provided in a flow path through which hydrogen is discharged from a cathode of the electrochemical hydrogen pump and flows into the gas-liquid separator,
5. The controller according to claim 1, wherein the controller closes the second valve when the pressure of the boosted hydrogen is higher than the first pressure and equal to or higher than a second pressure that is equal to or lower than the upper limit of pressure. The hydrogen system according to any one of claims 1 to 4.   The hydrogen according to any one of claims 1 to 5, further comprising a moisture remover provided in a flow path between the gas-liquid separator and the hydrogen utilization device, the moisture remover including an adsorbent that removes moisture accompanied by hydrogen. system.

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