Electrochemical hydrogen boosting system

Abstract

The invention provides an electrochemical hydrogen boosting system. An electrochemical hydrogen boosting system (10) is provided with: a hydrogen boosting stack (16) that discharges hydrogen gas supplied to an anode electrode as high-pressure hydrogen gas boosted by a cathode electrode through an electrolyte membrane; the hydrogen supply device supplies the hydrogen gas to the anode electrode of the hydrogen booster stack (16) through a hydrogen supply flow channel (60); the PSA device has a plurality of adsorption towers (24) for dehumidifying the high-pressure hydrogen gas discharged from the hydrogen booster stack (16), and has a return flow path (94), and regenerated hydrogen gas used for regeneration of the adsorption towers (24) is returned to the hydrogen supply flow path (60) or the hydrogen supply device (14). Accordingly, a decrease in hydrogen production efficiency of the electrochemical hydrogen booster system can be suppressed.

Description

Technical Field

[0001] The present invention relates to an electrochemical hydrogen pressure boosting system. Background Art

[0002] In recent years, in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy, research and development of electrochemical hydrogen boosting systems that help improve energy efficiency have been underway.

[0003] Japanese Patent Application Publication No. 2022-94891 discloses an electrochemical hydrogen boosting system for boosting the pressure of hydrogen. This electrochemical hydrogen boosting system includes an electrochemical hydrogen boosting device. The electrochemical hydrogen boosting device comprises a single cell consisting of a proton exchange membrane (electrolyte membrane) and an anode and cathode disposed on either side of the proton exchange membrane. By applying a current between the anode and cathode, the hydrogen supplied to the anode is boosted, generating high-pressure hydrogen at the cathode.

[0004] Japanese Patent Application Laid-Open No. 2009-291732 discloses a PSA-type dehumidifier that produces low-dew-point air through pressure swing adsorption. This PSA-type dehumidifier alternately processes a treatment process in which treated air passes through an adsorption vessel containing adsorbent, and a regeneration process in which regenerated air passes through the vessel, producing low-dew-point air through pressure swing adsorption. Summary of the Invention

[0005] Furthermore, the high-pressure hydrogen gas generated by an electrochemical hydrogen boosting system contains a significant amount of water. Therefore, to supply this hydrogen gas to a hydrogen tank in a fuel cell system mounted on a mobile object such as a vehicle, for example, it is necessary to remove the water contained in the hydrogen gas. In this case, a PSA device is considered for removing the water contained in the hydrogen gas.

[0006] The PSA system has at least two adsorption towers that hold adsorbent. When the moisture adsorption capacity in one tower reaches its upper limit, the system switches to the other tower to continue removing moisture. Regeneration hydrogen is then circulated through the first tower to discharge the adsorbed moisture. However, the regeneration hydrogen contains a significant amount of moisture, making it unsuitable for use in fuel cell systems. This results in low hydrogen production efficiency in electrochemical hydrogen boost systems.

[0007] The purpose of the present invention is to solve the above-mentioned technical problems.

[0008] The first embodiment of the present invention is an electrochemical hydrogen boosting system, which has a hydrogen boosting stack, a power supply device, a hydrogen supply device and a PSA device, wherein the hydrogen boosting stack has a single cell, the single cell includes an electrolyte membrane, an anode electrode arranged on one side of the electrolyte membrane and a cathode electrode arranged on the other side of the electrolyte membrane, the hydrogen boosting stack supplies hydrogen to the anode electrode and discharges high-pressure hydrogen boosted by the cathode electrode; the power supply device applies voltage to the hydrogen boosting stack; the hydrogen supply device supplies hydrogen to the hydrogen boosting stack through a hydrogen supply flow channel; the PSA device has a plurality of adsorption towers for dehumidifying the high-pressure hydrogen discharged from the hydrogen boosting stack, and the electrochemical hydrogen boosting system has a return flow channel, so that the regenerated hydrogen used for regeneration of the adsorption tower flows back to the hydrogen supply flow channel of the hydrogen boosting stack or the hydrogen supply device.

[0009] According to the above embodiment, the regenerated hydrogen gas used for regeneration is returned to the hydrogen supply channel or hydrogen supply device of the hydrogen booster stack through the return flow channel, so the regenerated hydrogen gas can be used without being discharged to the outside and wasted. Therefore, the reduction in hydrogen production efficiency of the electrochemical hydrogen booster system can be suppressed.

[0010] The above-mentioned objects, features and advantages will be easily understood through the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic configuration diagram of an electrochemical hydrogen pressure boosting system according to an embodiment.

[0012] Figure 2 (a) is an explanatory diagram of the adsorption process in the adsorption tower A of the PSA apparatus. Figure 2 (b) is an explanatory diagram of the adsorption process in the adsorption tower B of the PSA device. Figure 2 (c) is an explanatory diagram of the regeneration step of the adsorption tower A of the PSA device. Figure 2 (d) is an explanatory diagram of the regeneration step of the adsorption tower B of the PSA device.

[0013] Figure 3 This is a flow chart of the adsorption process and regeneration process of the PSA device.

[0014] Figure 4 Then Figure 3 Flowchart of the adsorption process and regeneration process of the PSA device.

[0015] Figure 5 It is a timing chart of each process of the adsorption tower A and the adsorption tower B and the supply of raw material hydrogen. DETAILED DESCRIPTION

[0016] Figure 11 is a schematic diagram showing an electrochemical hydrogen pressure boosting system 10 according to an embodiment. The electrochemical hydrogen pressure boosting system 10 includes an electrochemical hydrogen pressure boosting device 12 , a hydrogen supply device 14 , a gas-liquid separator 18 , a condenser 20 , a PSA device 22 , and a control device 30 .

[0017] The electrochemical hydrogen pressure booster 12 electrochemically boosts the pressure of hydrogen gas and includes a hydrogen pressure booster stack 16 and a power supply 28 for applying voltage to the hydrogen pressure booster stack 16 .

[0018] The hydrogen booster stack 16 has a hydrogen inlet PT1, a hydrogen outlet PT2, and a high-pressure hydrogen outlet PT3. The hydrogen inlet PT1 supplies hydrogen gas from the hydrogen supply device 14 to the hydrogen booster stack 16. The supplied hydrogen gas is connected to the anode electrode 36 of each cell 32. The hydrogen outlet PT2 discharges unused hydrogen gas. The high-pressure hydrogen outlet PT3 discharges the high-pressure hydrogen gas generated in the cell 32. The high-pressure hydrogen gas is connected to the cathode electrode 40 of each cell 32.

[0019] The hydrogen booster stack 16 is constructed by stacking a plurality of unit cells 32. Each unit cell 32 has the same structure. Each unit cell 32 includes an electrolyte membrane 34, an anode electrode 36 disposed on one side of the electrolyte membrane 34, an anode power supply 37, a cathode electrode 40 disposed on the other side of the electrolyte membrane 34, and a cathode power supply 41.

[0020] The electrolyte membrane 34 is, for example, a solid polymer electrolyte membrane (cation exchange membrane). The electrolyte membrane 34 may be reinforced on the anode side with a protective sheet (not shown) comprising a fibrous skeleton. This allows it to effectively withstand the pressure of high-pressure hydrogen gas applied from the cathode side. In addition to fluorine electrolytes, the electrolyte membrane 34 may also use an HC (hydrocarbon) electrolyte. The electrolyte membrane 34 is sandwiched between the anode electrode 36 and the cathode electrode 40.

[0021] The anode electrode 36 includes an anode catalyst layer bonded to one side of the electrolyte membrane 34. An anode power supply 37 is stacked on the anode catalyst layer. The anode catalyst layer includes a platinum-based catalyst. An anode flow channel for hydrogen flow is formed on the anode power supply 37. Hydrogen supplied from the hydrogen inlet PT1 flows through the anode flow channel and reaches the anode catalyst layer. A porous reinforcing plate can be sandwiched between the anode catalyst layer and the anode power supply 37. The reinforcing plate can well withstand the pressure of the high-pressure hydrogen gas applied from the cathode side.

[0022] The cathode electrode 40 includes a cathode catalyst layer bonded to the other surface of the electrolyte membrane 34. A cathode current generator 41 is stacked on the cathode catalyst layer. The cathode catalyst layer contains a platinum-based catalyst. A cathode flow channel is formed on the cathode current generator 41 for circulating the boosted high-pressure hydrogen gas. The generated high-pressure hydrogen gas flows through the cathode flow channel and is discharged from the high-pressure hydrogen outlet PT3.

[0023] When a voltage is applied between the anode electrode 36 and the cathode electrode 40, the hydrogen supplied from the hydrogen inlet PT1 to the anode electrode 36 is ionized into protons (hydrogen ions) and electrons by a catalytic reaction in the anode catalyst layer. The generated protons pass through the electrolyte membrane 34 and move toward the cathode electrode 40. At this time, the protons bring moisture to the cathode electrode 40. Therefore, the hydrogen supplied to the anode electrode 36 needs to be humidified. In the cathode electrode 40, high-pressure hydrogen is generated by an electrochemical reaction in which protons and electrons that pass through the electrolyte membrane 34 are bonded. Unused hydrogen that is not ionized at the anode electrode 36 is exported from the hydrogen outlet PT2. The pressure of the high-pressure hydrogen circulating in the cathode flow channel is higher than the pressure of the hydrogen circulating in the anode flow channel.

[0024] The power supply device 28 applies a DC voltage to the hydrogen booster stack 16. This causes current to flow through the hydrogen booster stack 16. The hydrogen booster stack 16 comprises a stack of multiple cells 32, with anode and cathode terminals (not shown) located at each end of the stack. The positive terminal of the power supply device 28 is connected to the anode terminal via a connection cable, and the negative terminal of the power supply device 28 is connected to the cathode terminal via a connection cable. This applies a positive potential to the anode electrode 36 of each cell 32, and a negative potential to the cathode electrode 40 of each cell 32.

[0025] The power supply unit 28 is configured to adjust the voltage applied to the hydrogen booster stack 16 in response to control commands from the control unit 30. The voltage supplied to the hydrogen booster stack 16 is applied equally to each cell 32. As the voltage supplied to the hydrogen booster stack 16 increases, the current flowing increases, and the amount of high-pressure hydrogen gas generated in the hydrogen booster stack 16 increases.

[0026] The hydrogen supply device 14 includes a sealed container 44 that stores liquid water at a downward angle in the direction of gravity. Raw hydrogen is supplied to the liquid water in the sealed container 44 via a raw hydrogen supply path 50. A raw hydrogen valve 52 is provided on the raw hydrogen supply path 50. Raw hydrogen valve 52 allows the flow of raw hydrogen by opening the valve and stops the flow of raw hydrogen by closing the valve.

[0027] An opening is provided at one end of the raw hydrogen supply path 50. This opening opens into the liquid water in the sealed container 44. Hydrogen gas, serving as raw hydrogen, is discharged from the opening, forming bubbles in the liquid water and floating above the sealed container 44. At this point, droplets contained in the raw hydrogen are absorbed into the liquid water. Furthermore, the hydrogen gas floating above the liquid water is humidified by the liquid water. The sealed container 44 functions as both a gas-liquid separator 18 and a humidifier.

[0028] The raw hydrogen can simply contain hydrogen gas, for example, and can be produced by electrolysis of water. Alternatively, the raw hydrogen can be produced by a reforming reaction of a hydrocarbon-containing feedstock. The raw hydrogen can also contain impurities other than hydrogen gas, such as conductive components such as potassium hydroxide contained in the electrolyte during the electrolysis of water, or produced during the reforming reaction. These impurities are removed by the hydrogen booster stack 16 and are not included in the generated high-pressure hydrogen gas.

[0029] A space 45 is formed above the liquid water stored in the sealed container 44 to collect the hydrogen gas that has passed through the liquid water and become humidified. The hydrogen gas contained within the space 45 is pressurized to a predetermined pressure. A pressure sensor 64 is provided on the sealed container 44, communicating with the space 45 and measuring the pressure of the hydrogen gas contained therein. Furthermore, a hydrogen outlet 46 is provided above the sealed container 44, communicating with the space 45 and for discharging the hydrogen gas. The hydrogen gas, pressurized to the predetermined pressure, is discharged through the hydrogen outlet 46.

[0030] The hydrogen outlet 46 is connected to the hydrogen inlet PT1 of the hydrogen booster stack 16 via a hydrogen supply channel 60. The hydrogen outlet PT2 of the hydrogen booster stack 16 is connected to the hydrogen circulation port 67 of the sealed container 44 via a hydrogen circulation channel 62. The hydrogen circulation port 67 is connected to the liquid water in the sealed container 44. Hydrogen gas not used in the hydrogen booster stack 16 circulates in the sealed container 44. A circulation pump 66 is provided in the hydrogen circulation channel 62 to circulate the hydrogen gas.

[0031] The high-pressure hydrogen outlet PT3 of the hydrogen booster stack 16 is connected to the inlet path 80 of the PSA unit 22 via a high-pressure hydrogen supply channel 70. The high-pressure hydrogen supply channel 70 is provided with a backpressure valve 71, a check valve 72, a gas-liquid separator 18, and a condenser 20, in order from the upstream side. The condenser 20 can be provided to meet the required specifications of the high-pressure hydrogen and may be omitted.

[0032] The back pressure valve 71 adjusts the pressure of the high pressure hydrogen gas discharged from the hydrogen booster stack 16 . The check valve 72 allows the high pressure hydrogen gas to flow from the hydrogen booster stack 16 to the gas-liquid separator 18 and prevents the high pressure hydrogen gas from flowing back from the gas-liquid separator 18 to the hydrogen booster stack 16 .

[0033] The gas-liquid separator 18 removes the liquid component (liquid droplets) contained in the high-pressure hydrogen gas as liquid water. The gas-liquid separator 18 supplies the high-pressure hydrogen gas, after the liquid water has been removed, to the PSA unit 22 located downstream. The gas-liquid separator 18 comprises a sealed container. A position switch 77 for measuring the amount of stored liquid water is installed within the gas-liquid separator 18. The position switch 77 measures the height of the liquid level (the upper surface of the liquid water) stored within the sealed container.

[0034] A discharge passage 78 for discharging the separated liquid water to the outside is connected to the lower side of the gas-liquid separator 18 in the direction of gravity. A throttle valve 75 and an on-off valve 79 are provided in order from upstream on the discharge passage 78. The throttle valve 75 adjusts the flow rate of the liquid water flowing through the discharge passage 78. The on-off valve 79 discharges the liquid water from the discharge passage 78 by opening the valve and stops the discharge of the liquid water by closing the valve. When the control device 30 detects, based on a signal from the position switch 77, that the amount of liquid water stored in the gas-liquid separator 18 exceeds the upper limit, it opens the on-off valve 79 to discharge the liquid water to the outside.

[0035] A pressure relief passage 76, communicating with the high-pressure hydrogen gas within, is connected to the upper portion of the gas-liquid separator 18 in the direction of gravity. A pressure reducing valve 73 and a flow control valve 74 are provided in this pressure relief passage 76, starting from the upstream. In the pressure relief passage 76, the pressure inside the passage connected to the hydrogen booster stack 16 is relieved by adjusting the pressure reducing valve 73 and the flow control valve 74. The pressure reducing valve 73 reduces the pressure of the high-pressure hydrogen gas flowing through the pressure relief passage 76 to a pressure suitable for pressure relief. The flow control valve 74 adjusts the flow rate of the high-pressure hydrogen gas flowing through the pressure relief passage 76 and stops the discharge of hydrogen by closing the valve.

[0036] The condenser 20 is installed between the gas-liquid separator 18 and the PSA unit 22. The condenser 20 cools the high-pressure hydrogen gas by exchanging heat with the circulating high-pressure hydrogen gas. This condenses the water vapor contained in the high-pressure hydrogen gas, thereby reducing the humidity of the high-pressure hydrogen gas.

[0037] [PSA device] illustrate Figure 1 PSA unit 22 is shown.

[0038] The PSA unit 22 according to this embodiment includes multiple adsorption towers 24 (adsorption tower A and adsorption tower B). These multiple adsorption towers 24 are switched alternately, using an adsorbent to adsorb moisture contained in the introduced hydrogen gas and discharge the dried hydrogen gas. When the adsorption moisture content reaches the upper limit, dry hydrogen gas is circulated through the adsorption tower 24, and the adsorbed moisture is discharged for regeneration. The PSA unit 22 includes a hydrogen inlet 110 for introducing hydrogen gas and a hydrogen outlet 120 for discharging hydrogen gas.

[0039] The interior of each adsorption tower 24 of the PSA device 22 is filled with a porous adsorbent such as activated carbon, zeolite, alumina or silica. The adsorption tower 24 is composed of a cylindrical adsorption container. The cylindrical axis of the adsorption container is set along the direction of gravity. In addition, the axis can be set in the horizontal direction. In this embodiment, a PSA device 22 having two adsorption towers 24 (adsorption tower A and adsorption tower B) is described. However, the number of adsorption towers 24 is not limited to two, as long as there are multiple, it can be three or more.

[0040] A gas inlet (IN) is provided at the lower end of adsorption tower 24. Hydrogen gas, which is supplied through the gas inlet, is dehydrated by the adsorbent in adsorption tower 24 and discharged through a gas outlet (OUT). The gas outlet is located at the upper end of adsorption tower 24. When the water content of the adsorbent in adsorption tower 24 reaches its upper limit, its ability to absorb water decreases, necessitating water removal for regeneration.

[0041] The multiple adsorption towers 24 include a treatment adsorption tower that absorbs moisture contained in hydrogen gas for the adsorption process and a regeneration adsorption tower that discharges moisture adsorbed by the adsorbent for the regeneration process. The regeneration process uses hydrogen gas that has been dehumidified and dried in the adsorption process in another adsorption tower 24. However, a hydrogen storage device that stores dried hydrogen gas within the electrochemical hydrogen boosting system 10 may be provided, and hydrogen gas may be supplied from this hydrogen storage device. The multiple adsorption towers 24 alternately perform the adsorption process and the regeneration process.

[0042] The plurality of adsorption towers 24 include at least one treatment adsorption tower and at least one regeneration adsorption tower. There may be at least two treatment adsorption towers and at least one regeneration adsorption tower. Hydrogen gas (regeneration hydrogen) used to regenerate the regeneration adsorption tower and containing water is discharged from the regeneration hydrogen outlet 130 of the PSA unit 22. The plurality of adsorption towers 24 are constructed with the same specifications. However, the system may be constructed with adsorption towers 24 of different specifications.

[0043] The hydrogen inlet 110 of the PSA device 22 is connected to the high-pressure hydrogen outlet PT3 of the hydrogen booster stack 16 through the high-pressure hydrogen supply flow channel 70. The hydrogen outlet 120 of the PSA device 22 is connected to a hydrogen tank (not shown) through the high-pressure hydrogen outlet flow channel 122. A back pressure valve 124 is provided on the high-pressure hydrogen outlet flow channel 122 to adjust the pressure of the high-pressure hydrogen gas being discharged. An on-off valve (not shown) is provided on the high-pressure hydrogen outlet flow channel 122. High-pressure hydrogen gas is supplied by opening the valve and stopped by closing the valve. A connector that can disconnect the hydrogen tank can be provided between the high-pressure hydrogen outlet flow channel 122 and the hydrogen tank. The hydrogen tank is provided in a mobile vehicle, industrial equipment, fixed power generation device, etc. equipped with a fuel cell system. In addition, the high-pressure hydrogen outlet flow channel 122 can be directly connected to a fuel cell system that does not have a hydrogen tank. The regenerated hydrogen outlet 130 of the PSA device 22 is connected to the sealed container 44 of the hydrogen supply device 14 through the return flow channel 94. Therefore, the hydrogen gas (regeneration hydrogen gas) used for regenerating the adsorption tower refluxes into the interior of the closed container 44 .

[0044] The return flow channel 94 can be connected to the high-pressure hydrogen supply channel 70 connecting the gas-liquid separator 18 and the hydrogen booster stack 16. In this case, the return flow channel 94 is equivalent to being connected to the hydrogen inlet port PT1 of the hydrogen booster stack 16. In other words, the regenerated hydrogen gas discharged from the regenerated hydrogen outlet 130 flows back to the equipment upstream of the hydrogen booster stack 16 through the return flow channel 94.

[0045] The return flow channel 94 has a hydrogen discharge port at its downstream end. The hydrogen discharge port opens into the space 45 above the sealed container 44. Alternatively, the hydrogen discharge port may open into the liquid water within the sealed container 44. In this manner, the regenerated hydrogen gas discharged from the hydrogen discharge port is dehumidified by the liquid water, having its water droplets removed, and then reaches the space 45 above, where it is supplied to the hydrogen booster stack 16 via the hydrogen supply flow channel 60.

[0046] The return flow passage 94 is provided with a pressure reducing valve 96 and a flow regulating valve 98. The pressure reducing valve 96 reduces the pressure of the regenerated hydrogen gas discharged from the PSA unit 22. The reduced pressure regenerated hydrogen gas flows downstream. The flow regulating valve 98 adjusts the flow rate of the regenerated hydrogen gas discharged from the PSA unit 22. The flow regulating valve 98 adjusts the flow rate of the supplied regenerated hydrogen gas based on the pressure of the space 45 above the liquid water in the sealed container 44.

[0047] That is, when the flow rate of hydrogen supplied from the space 45 of the closed container 44 to the hydrogen booster stack 16 through the hydrogen supply flow channel 60 increases, the pressure of the space 45 of the closed container 44 detected by the pressure sensor 64 decreases. Therefore, the control device 30 adjusts the flow control valve 98 in a manner that increases the flow rate of the regenerated hydrogen supplied to the closed container 44 through the return flow channel 94, so that the pressure of the space 45 of the closed container 44 is maintained at a specified value. In addition, when the regenerated hydrogen is supplied to the closed container 44 through the return flow channel 94, the raw hydrogen is not supplied to the closed container 44. That is, the raw hydrogen valve 52 provided on the raw hydrogen supply path 50 is closed. In addition, the pressure of the regenerated hydrogen supplied from the return flow channel 94 is lower than the pressure of the raw hydrogen.

[0048] In addition to the multiple adsorption towers 24, the PSA unit 22 also includes multiple on-off valves VL1 to VL10 that control the flow of hydrogen gas into the adsorption towers 24 in response to commands from the control unit 30, and multiple connecting flow paths connected to these on-off valves VL1 to VL10. In the following description, the on-off valves VL1 to VL10 are simply referred to as VL1 to VL10. VL5 and VL6 are omitted.

[0049] The inlet path 80 connected to the hydrogen inlet 110 of the PSA device 22 branches at a branch point 86 into a first supply flow channel 82 and a second supply flow channel 84. The first supply flow channel 82 and the second supply flow channel 84 are respectively connected to the gas inlet of the adsorption tower A and the gas inlet of the adsorption tower B. On-off valves VL1 and VL2 are provided in the first supply flow channel 82 and the second supply flow channel 84, respectively, to control the flow of hydrogen gas in the first supply flow channel 82 and the second supply flow channel 84.

[0050] The first regenerated hydrogen discharge flow channel 90, which is connected to the regenerated hydrogen discharge port 130, is connected to the first supply flow channel 82 downstream of the on-off valve VL1. An on-off valve VL3 is provided in the first regenerated hydrogen discharge flow channel 90 to control the flow of hydrogen gas in the first regenerated hydrogen discharge flow channel 90. The second regenerated hydrogen discharge flow channel 92, which is connected to the regenerated hydrogen discharge port 130, is connected to the second supply flow channel 84 downstream of the on-off valve VL2. An on-off valve VL4 is provided in the second regenerated hydrogen discharge flow channel 92 to control the flow of hydrogen gas in the second regenerated hydrogen discharge flow channel 92.

[0051] The first regeneration hydrogen discharge flow path 90 and the second regeneration hydrogen discharge flow path 92 merge at a confluence point 93 on the downstream side and are connected to the regeneration hydrogen discharge port 130 .

[0052] A first discharge channel 102 and a second discharge channel 104 are connected to the gas outlet of adsorption tower A and the gas outlet of adsorption tower B, respectively. The first discharge channel 102 and the second discharge channel 104 merge at a confluence point 106 and are connected to a hydrogen outlet 120 via an outlet path 100. On-off valves VL7 and VL8 are provided in the first discharge channel 102 and the second discharge channel 104, respectively, to control the flow of hydrogen in the first discharge channel 102 and the second discharge channel 104.

[0053] The first purge flow path 102 upstream of the on-off valve VL7 and the second purge flow path 104 upstream of the on-off valve VL8 are connected to each other via an outlet bypass flow path 108. The outlet bypass flow path 108 is provided with an on-off valve VL9 and an on-off valve VL10 to control the flow of hydrogen in the outlet bypass flow path 108.

[0054] Dew point meters DP1 and DP2 are provided on the first exhaust flow channel 102 and the second exhaust flow channel 104 to measure the dew point of the hydrogen gas flowing through each flow channel. The dew point is the temperature at which water vapor contained in the hydrogen gas condenses when the hydrogen gas is cooled. The dew point is a physical quantity that indicates the amount of water contained in the hydrogen gas. The lower the dew point, the less water is contained, and the drier the hydrogen gas is. The dew point is measured using well-known dew point meters (DP1 to DP4), such as electrostatic capacitance type, mirror cooling type, and quartz oscillation type. In addition, a dew point meter DP3 is provided on the derivation path 100 to measure the dew point of the circulating hydrogen gas. The dew point meter DP3 measures the dew point of the hydrogen gas discharged from both the first exhaust flow channel 102 and the second exhaust flow channel 104.

[0055] [Operation of PSA Device] Next, use Figure 2 (a) to (d) illustrate the operation of the PSA device 22 according to the embodiment. In this embodiment, a PSA device 22 having two adsorption towers 24 is described. However, since the operation of a device having three or more adsorption towers 24 alternately performing the adsorption step and the regeneration step is the same as in this embodiment, a detailed description thereof will be omitted.

[0056] exist Figure 2 (a) shows an adsorption process in which hydrogen gas supplied from the hydrogen booster stack 16 is introduced into the hydrogen inlet 110 of the PSA device 22 , dehumidified in the adsorption tower A (treatment adsorption tower), and then discharged from the hydrogen outlet 120 .

[0057] Specifically, the control device 30 opens valve VL1 and closes valves VL2, VL3, and VL4. Consequently, hydrogen gas introduced from the hydrogen booster stack 16 through the hydrogen inlet 110 into the inlet path 80 flows through the branch point 86 and the first supply flow path 82, passes through the on-off valve VL1, and is supplied to the gas inlet of the adsorption tower A. The hydrogen gas supplied to the adsorption tower A is dehumidified by contact with the adsorbent contained within the adsorption tower A.

[0058] The controller 30 then opens valves VL7 and VL9 and closes valves VL8 and VL10. Consequently, the dehumidified and dried hydrogen (dry hydrogen) is discharged from the gas outlet of the adsorption tower A into the first discharge flow path 102, passes through the on-off valve VL7, flows through the confluence point 106 and the outlet path 100, and is discharged from the hydrogen outlet 120.

[0059] Dew point meters DP1 and DP3 are provided on the first exhaust flow path 102 and the outlet path 100, respectively, to measure the dew point of the circulating hydrogen gas.

[0060] exist Figure 2 (b) shows the adsorption process in which hydrogen gas supplied from the hydrogen booster stack 16 is supplied to the hydrogen inlet 110 of the PSA unit 22, dehumidified by adsorption tower B (treatment adsorption tower), and then discharged from the hydrogen outlet 120. This is the state in which the operation is switched to adsorption tower B (regeneration adsorption tower) after the amount of moisture adsorbed by adsorption tower A (treatment adsorption tower) reaches the upper limit.

[0061] Specifically, the control device 30 opens valve VL2 and closes valves VL1, VL3, and VL4. Consequently, hydrogen gas introduced from the hydrogen booster stack 16 through the hydrogen inlet 110 into the inlet path 80 flows through the branch point 86 and the second supply flow path 84, passes through the on-off valve VL2, and is supplied to the gas inlet of the adsorption tower B. The hydrogen gas supplied to the adsorption tower B is dehumidified by contact with the adsorbent contained within the adsorption tower B.

[0062] Furthermore, the controller 30 opens valves VL8 and VL10 and closes valves VL7 and VL9. Consequently, the dehumidified and dried hydrogen (dehumidified hydrogen) is discharged from the gas outlet of the adsorption tower B to the second discharge flow path 104, passes through the on-off valve VL8, flows through the confluence point 106 and the outlet path 100, and is discharged from the hydrogen outlet 120.

[0063] A dew point meter DP2 and a dew point meter DP3 are respectively provided on the second exhaust flow path 104 and the outlet path 100 to measure the dew point of the circulating hydrogen gas.

[0064] exist Figure 2(c) shows a regeneration step in which dehumidified hydrogen is supplied from adsorption tower B (treatment adsorption tower) to adsorption tower A (regeneration adsorption tower), moisture contained in the adsorbent of adsorption tower A is discharged, and adsorption tower A is regenerated.

[0065] Specifically, the control device 30 opens valves VL2 and VL3 and closes valves VL1 and VL4. Consequently, hydrogen gas introduced from the hydrogen booster stack 16 into the introduction path 80 through the hydrogen inlet 110 branches at the branch point 86 and flows through the second supply flow path 84, passing through the on-off valve VL2 and being supplied to the gas inlet of the adsorption tower B. The hydrogen gas supplied to the adsorption tower B is dehumidified by contact with the adsorbent contained within the adsorption tower B.

[0066] Furthermore, the control device 30 opens valves VL8, VL9, and VL10 and closes valve VL7. Consequently, dehumidified hydrogen is supplied from the gas outlet of adsorption tower B through outlet bypass flow channel 108 to the gas outlet of adsorption tower A. Simultaneously, the dehumidified hydrogen is discharged from the gas outlet of adsorption tower B to the second discharge flow channel 104, passes through opening and closing valve VL8, flows through confluence point 106 and outlet path 100, and is discharged from hydrogen outlet 120. The regenerated hydrogen gas, which has absorbed the moisture discharged from the adsorbent of adsorption tower A, is discharged from the gas inlet of adsorption tower A and is discharged through the first regenerated hydrogen discharge flow channel 90 to the regenerated hydrogen discharge outlet 130. In this case, a throttle valve (not shown) can be provided on outlet bypass flow channel 108 to reduce the pressure of the hydrogen discharged from adsorption tower B and supply it to adsorption tower A. This allows for further improved regeneration of adsorption tower A.

[0067] exist Figure 2 (d) shows a regeneration step in which dehumidified hydrogen is supplied from adsorption tower A (treatment adsorption tower) to adsorption tower B (regeneration adsorption tower) to discharge moisture contained in the adsorbent of adsorption tower B to regenerate adsorption tower B.

[0068] Specifically, the control device 30 opens valves VL1 and VL4 and closes valves VL2 and VL3. Consequently, hydrogen gas introduced from the hydrogen booster stack 16 into the inlet path 80 via the hydrogen inlet port 110 flows through the branch point 86 and the first supply flow path 82, and is supplied from the on-off valve VL1 through the gas inlet of the adsorption tower A. The hydrogen gas supplied to the adsorption tower A is dehumidified by contact with the adsorbent contained within the adsorption tower A.

[0069] Furthermore, the control device 30 opens valves VL7, VL9, and VL10, and closes valve VL8. Consequently, dehumidified hydrogen is supplied from the gas outlet of adsorption tower A through the outlet bypass flow channel 108 to the gas outlet of adsorption tower B. Simultaneously, the dehumidified hydrogen is discharged from the gas outlet of adsorption tower A to the first discharge flow channel 102, passes through the on-off valve VL7, flows through the confluence point 106 and the outlet path 100, and is discharged from the hydrogen outlet 120. Regenerated hydrogen, which has absorbed moisture discharged from the adsorbent of adsorption tower B, is discharged from the gas inlet of adsorption tower B and is discharged from the regenerated hydrogen outlet 130 through the second regenerated hydrogen discharge flow channel 92. In this case, a throttle valve (not shown) can be provided on the outlet bypass flow channel 108 to reduce the pressure of the hydrogen discharged from adsorption tower A and supply it to adsorption tower B. Consequently, adsorption tower B can be regenerated more effectively.

[0070] The control device 30 is comprised of an ECU (Electronic Control Unit). The ECU is a computer system comprising one or more processors (CPUs), memory, input / output interfaces, and electronic circuits. The one or more processors (CPUs) execute programs (computer-executable instructions) stored in the memory (not shown). The control device 30 performs all controls related to the electrochemical hydrogen boosting system 10.

[0071] Reference Figure 1 The operation of the electrochemical hydrogen pressure boosting system 10 will be described.

[0072] The controller 30 opens the raw hydrogen valve 52 provided in the raw hydrogen supply path 50 to supply raw hydrogen to the hydrogen supply device 14. The raw hydrogen supplied to the sealed container 44 of the hydrogen supply device 14 has its moisture content adjusted and is then supplied as hydrogen gas to the hydrogen inlet PT1 of the hydrogen booster stack 16 via the hydrogen outlet 46 and the hydrogen supply flow path 60. Unused hydrogen gas discharged from the hydrogen outlet PT2 of the hydrogen booster stack 16 circulates through the hydrogen circulation flow path 62 to the hydrogen circulation port 67 of the sealed container 44. The controller 30 controls the rotational speed of the circulation pump 66 provided in the hydrogen circulation flow path 62 to adjust the flow rate of the circulating hydrogen gas.

[0073] The hydrogen supplied to the hydrogen booster stack 16 is electrochemically boosted to high-pressure hydrogen gas, which is then discharged from the high-pressure hydrogen outlet PT3 to the high-pressure hydrogen supply flow path 70. After liquid water is removed from the high-pressure hydrogen by the gas-liquid separator 18, the high-pressure hydrogen gas is supplied to the condenser 20. The high-pressure hydrogen gas, dehumidified by the condenser 20, is supplied to the PSA unit 22. Subsequently, after further dehumidification by the PSA unit 22, the high-pressure hydrogen gas is supplied as dried gas to a hydrogen tank or the like through the high-pressure hydrogen outlet flow path 122.

[0074] [Flowchart of the electrochemical hydrogen boost system] according to Figure 3 、 Figure 4 The operation sequence of the adsorption process and the regeneration process of the electrochemical hydrogen pressure boosting system 10 according to the embodiment will be described with reference to the flowchart shown in FIG.

[0075] In step S1, the control device 30 measures the dew point of water contained in the hydrogen discharged in the adsorption process using the dew point meter DP1 installed in the first discharge flow path 102 of the adsorption tower A of the PSA device 22. The measured dew point is sent to the control device 30, and the control device 30 estimates the water content contained in the adsorption tower A based on the dew point. In addition, in step S1, the PSA device 22 implements the above-mentioned Figure 2 (a) adsorption step.

[0076] In step S2, the control device 30 determines whether the dew point measured by the dew point meter DP1 is above a predetermined value DP_H (dew point upper limit). If the determination is positive (step S2: Yes), the control device 30 proceeds to step S3. If the determination is negative (step S2: No), the control device 30 returns to step S1. The predetermined value DP_H is set based on the upper limit of the water content that the adsorbent filled in the adsorption tower 24 can absorb. As the water content of the adsorbent increases, the amount of water that can be adsorbed decreases, and the dew point increases. The predetermined value DP_H is the dew point of the hydrogen gas emitted when the water content of the adsorbent reaches the upper limit.

[0077] In this embodiment, the water content of the adsorbent is estimated based on the dew point. However, the water content of the adsorbent can be estimated based on the cumulative flow rate of hydrogen, the time the hydrogen has been flowing through the adsorption tower 24, or the weight of the adsorption tower 24, instead of the dew point, and a corresponding predetermined value can be set. Similarly, in the following description, physical quantities such as the cumulative flow rate of hydrogen, the time the hydrogen has been flowing through the adsorption tower 24, or the weight of the adsorption tower 24 can be used instead of the dew point.

[0078] In step S3, the control device 30 switches from the adsorption tower A to the adsorption tower B by controlling the on-off valves VL1 to VL10. Specifically, as already described, the control device 30 switches from the PSA unit 22 to the adsorption tower B. Figure 2 The state shown in (a) is Figure 2 The state shown in (b) is transferred to switch from adsorption tower A to adsorption tower B.

[0079] In step S4, the control device 30 starts the regeneration process of regenerating the adsorption tower A by controlling the opening and closing valves VL1 to VL10. Specifically, as described above, the control device 30 starts the regeneration process of regenerating the adsorption tower A by controlling the opening and closing valves VL1 to VL10. Figure 2 The state shown in (b) Figure 2 The state shown in (c) is shifted to start the regeneration step of the adsorption tower A.

[0080] In step S5 , the control device 30 closes (or shuts down) the raw hydrogen valve 52 provided in the raw hydrogen supply path 50 , thereby stopping the supply of raw hydrogen to the hydrogen supply device 14 .

[0081] In step S6, the control device 30 controls the pressure reducing valve 96 and the flow regulating valve 98 to supply the regenerated hydrogen gas discharged from the regenerated hydrogen outlet 130 of the PSA unit 22 to the hydrogen supply device 14 via the return flow path 94. The control device 30 then supplies the regenerated hydrogen gas as hydrogen gas to the hydrogen booster stack 16, and supplies the high-pressure hydrogen gas discharged from the hydrogen booster stack 16 to the adsorption tower B of the PSA unit 22 via the gas-liquid separator 18 and the condenser 20.

[0082] In step S7 , the control device 30 measures the dew point of the regenerated hydrogen gas discharged in the regeneration step of the adsorption tower A using the dew point meter DP4 provided in the return flow passage 94 .

[0083] In step S8, the control device 30 determines whether the dew point measured by the dew point meter DP4 is lower than a pre-set value DP_L (dew point lower limit). If the determination is positive (step S8: Yes), the control device 30 proceeds to step S9. If the determination is negative (step S8: No), the control device 30 returns to step S7. The pre-set value DP_L is set based on the moisture content of the adsorbent. When the dew point measured by the dew point meter DP4 drops to the pre-set value DP_L as the moisture content of the adsorbent decreases, the control device 30 determines that the moisture contained in the adsorbent has been fully discharged and proceeds to step S9, completing the regeneration process of the adsorption tower A.

[0084] In step S10, the control device 30 starts the adsorption process of the adsorption tower B by controlling the opening and closing valves VL1 to VL10. Specifically, as described above, the control device 30 starts the adsorption process of the adsorption tower B by controlling the PSA unit 22 to Figure 2 The state shown in (c) Figure 2 The state shown in (b) is transferred to the adsorption process of the adsorption tower B.

[0085] In step S11 , the control device 30 opens the raw hydrogen valve 52 provided in the raw hydrogen supply path 50 , thereby starting the supply of raw hydrogen to the hydrogen supply device 14 .

[0086] In step S12, the control device 30 measures the dew point of the water contained in the hydrogen discharged in the adsorption process using the dew point meter DP2 installed in the second discharge flow path 104 of the adsorption tower B of the PSA device 22. The measured dew point is sent to the control device 30, and the control device 30 estimates the water content contained in the adsorption tower B based on the dew point. In addition, in step S12, the PSA device 22 implements the above-mentioned Figure 2 (b) adsorption step.

[0087] In step S13, similar to step S2, the control device 30 determines whether the dew point measured by the dew point meter DP2 is greater than or equal to a predetermined value DP_H (dew point upper limit). If the determination result is affirmative (step S13: Yes), the control device 30 proceeds to step S14. If the determination result is negative (step S13: No), the control device 30 returns to step S12. Here, the predetermined value DP_H is set similarly to step S2.

[0088] Furthermore, the prescribed values ​​of the dew point (DP_H, DP_L) may be set to different values ​​for adsorption tower A and adsorption tower B. Furthermore, when a physical quantity such as the accumulated flow rate of hydrogen gas, the flow time of hydrogen gas, or the weight of the adsorption tower 24 is used instead of the dew point, different prescribed values ​​(upper limit and lower limit) may be set for adsorption tower A and adsorption tower B.

[0089] In step S14, the control device 30 switches from the adsorption tower B to the adsorption tower A by controlling the on-off valves VL1 to VL10. Specifically, as already described, the control device 30 switches from the PSA unit 22 to the adsorption tower A. Figure 2 The state shown in (b) Figure 2 The state shown in (a) is transferred to switch from the adsorption tower B to the adsorption tower A.

[0090] In step S15, the control device 30 starts the regeneration process of regenerating the adsorption tower B by controlling the opening and closing valves VL1 to VL10. Specifically, as described above, the control device 30 starts the regeneration process of regenerating the adsorption tower B by controlling the opening and closing valves VL1 to VL10. Figure 2 The state shown in (a) is Figure 2 The state shown in (d) is transferred to start the regeneration process of the adsorption tower B.

[0091] In step S16 , the control device 30 closes the raw hydrogen valve 52 provided in the raw hydrogen supply path 50 , thereby stopping the supply of raw hydrogen to the hydrogen supply device 14 .

[0092] In step S17, the control device 30 controls the pressure reducing valve 96 and the flow regulating valve 98 to supply the regenerated hydrogen gas discharged from the regenerated hydrogen outlet 130 of the PSA unit 22 to the hydrogen supply device 14 via the return flow path 94. The control device 30 then supplies the regenerated hydrogen gas as hydrogen gas to the hydrogen booster stack 16, and supplies the high-pressure hydrogen gas discharged from the hydrogen booster stack 16 to the adsorption tower B of the PSA unit 22 via the gas-liquid separator 18 and the condenser 20.

[0093] In step S18 , the control device 30 measures the dew point of the regenerated hydrogen gas discharged in the regeneration step of the adsorption tower B using the dew point meter DP4 provided in the return flow passage 94 .

[0094] In step S19, the control device 30 determines whether the dew point measured by the dew point meter DP4 is lower than a preset value DP_L (dew point lower limit). If the determination result is affirmative (step S19: Yes), the control device 30 proceeds to step S20. If the determination result is negative (step S19: No), the control device 30 returns to step S18. Here, the preset value DP_L is set in the same manner as in step S8. The control device 30 proceeds to step S20, completing the regeneration process of the adsorption tower B.

[0095] In step S21, the control device 30 starts the adsorption process of the adsorption tower A by controlling the opening and closing valves VL1 to VL10. Specifically, as described above, the control device 30 starts the adsorption process of the adsorption tower A by controlling the opening and closing valves VL1 to VL10. Figure 2 The state shown in (d) Figure 2 The state shown in (a) is transferred to the adsorption process of the adsorption tower A.

[0096] In step S22 , the control device 30 opens the raw hydrogen valve 52 provided in the raw hydrogen supply path 50 , thereby starting the supply of raw hydrogen to the gas-liquid separator 18 .

[0097] [Timing Diagram] according to Figure 5 The timing diagram of the adsorption tower A, adsorption tower B and the supply of raw hydrogen according to this embodiment is described. Figure 2 (a)~ Figure 2 The adsorption step and regeneration step described in (d) Figure 3 and Figure 4 Flowchart described.

[0098] At time t0, the control device 30 starts the adsorption process in the adsorption tower A. The adsorption tower A dehumidifies the water contained in the hydrogen and outputs the dried hydrogen. Figure 2In this case, the control device 30 performs a standby process on the adsorption tower B, and no hydrogen is supplied to the adsorption tower B. Raw hydrogen is supplied from the hydrogen supply device 14 to the hydrogen booster stack 16, and the boosted high-pressure hydrogen is supplied to the adsorption tower A.

[0099] At time t1, the control device 30 begins the dew point measurement process (step S1) by measuring the dew point of hydrogen gas using the dew point meter DP1. Time t1 is set after a predetermined time T1 has elapsed from time t0. The predetermined time T1 is the time it takes for the water content of the adsorbent contained in adsorption tower A to approximately approach the upper limit. This predetermined time T1 is pre-set through experimentation. Alternatively, adsorption tower A can begin the dew point measurement process simultaneously with the start of the adsorption process, without waiting for the predetermined time T1 to elapse.

[0100] At time t2, the control device 30 determines that the dew point measured by the dew point meter DP1 is greater than the specified value DP_H (step S2: Yes). Next, the control device 30 switches from adsorption tower A to adsorption tower B (see step S3). That is, instead of adsorption tower A, adsorption tower B dehumidifies the moisture contained in the high-pressure hydrogen supplied from the hydrogen booster stack 16 and outputs the dried hydrogen. Inside the PSA device 22, as shown in FIG. Figure 2 Hydrogen gas is circulated as indicated by the arrow in (b).

[0101] After switching from adsorption tower A to adsorption tower B, the control device 30 starts the regeneration process of adsorption tower A (step S4). Dried hydrogen is supplied from adsorption tower B to adsorption tower A, and adsorption tower A is regenerated. Figure 2 Hydrogen flows as indicated by the arrow in (c). In this case, the control device 30 stops the supply of raw hydrogen (step S5). The control device 30 supplies the regenerated hydrogen gas discharged from the PSA unit 22 to the hydrogen supply device 14. Next, the control device 30 supplies the regenerated hydrogen gas as hydrogen gas to the hydrogen booster stack 16, and supplies the high-pressure hydrogen gas discharged from the hydrogen booster stack 16 to the adsorption tower B of the PSA unit 22.

[0102] At time t3, the control device 30 begins a dew point measurement process (step S7) to measure the dew point of hydrogen gas using the dew point meter DP4. Time t3 is set after a predetermined time T2 has elapsed since time t2. The predetermined time T2 is the time it takes for the water content of the adsorbent contained in adsorption tower A to approximately approach the lower limit. This predetermined time T2 is pre-set through experimentation. Alternatively, adsorption tower A can begin the dew point measurement process simultaneously with the start of the regeneration process, without waiting for the predetermined time T2 to elapse.

[0103] At time t4, when the control device 30 determines that the dew point measured by the dew point meter DP3 is less than the specified value DP_L (step S8: Yes), the regeneration process of the adsorption tower A is completed (step S9). As a result, the supply of hydrogen from the adsorption tower B to the adsorption tower A is stopped. The control device 30 starts the adsorption process of the adsorption tower B (step S10). Inside the PSA device 22, as shown in FIG. Figure 2 Hydrogen flows as indicated by the arrow in (b). In this case, the control device 30 starts supplying raw hydrogen (step S11). The supplied raw hydrogen gas is adjusted for moisture by the hydrogen supply device 14 and then supplied as hydrogen to the hydrogen booster stack 16. The control device 30 supplies the high-pressure hydrogen gas, which has been pressurized by the hydrogen booster stack 16, to the adsorption tower B. The adsorption tower A performs a standby process.

[0104] At time t5, the control device 30 begins the dew point measurement process using the dew point meter DP2 (see step S12). Time t5 is set after a predetermined time T1 has elapsed since time t4. The predetermined time T1 is the time it takes for the water content of the adsorbent contained in adsorption tower B to approximately approach the upper limit. This predetermined time T1 is pre-set through experiments. Alternatively, adsorption tower B can begin the dew point measurement process simultaneously with the start of the adsorption process, without waiting for the predetermined time T1 to elapse.

[0105] At time t6, the control device 30 determines that the dew point measured by the dew point meter DP2 is greater than the specified value DP_H (step S13: Yes). Next, the control device 30 switches from adsorption tower B to adsorption tower A (step S14). That is, adsorption tower A replaces adsorption tower B to dehumidify the moisture contained in the high-pressure hydrogen supplied from the hydrogen booster stack 16 and outputs the dried hydrogen. Inside the PSA device 22, as shown in FIG. Figure 2 Hydrogen gas is circulated as indicated by the arrow in (a).

[0106] After switching from adsorption tower B to adsorption tower A, the control device 30 starts the regeneration process of adsorption tower B (step S15). Dried hydrogen is supplied from adsorption tower A to adsorption tower B, and adsorption tower B is regenerated. Figure 2 Hydrogen flows as indicated by the arrow in (d). In this case, the control device 30 stops the supply of raw hydrogen (step S16). The control device 30 supplies the regenerated hydrogen gas discharged from the PSA unit 22 to the hydrogen supply device 14. Next, the control device 30 supplies the regenerated hydrogen gas as hydrogen gas to the hydrogen booster stack 16, and supplies the high-pressure hydrogen gas discharged from the hydrogen booster stack 16 to the adsorption tower A of the PSA unit 22.

[0107] At time t7, the control device 30 begins the dew point measurement process (see step S18) by measuring the dew point of hydrogen gas using the dew point meter DP4. Time t7 is set after a predetermined time T2 has elapsed since time t6. The predetermined time T2 is the time it takes for the water content of the adsorbent contained in adsorption tower B to approximately approach the lower limit. This predetermined time T2 is pre-set through experiments. Alternatively, the dew point measurement process can be initiated simultaneously with the start of the regeneration process in adsorption tower B, without waiting for the predetermined time T2 to elapse.

[0108] At time t8, the control device 30 determines that the dew point measured by the dew point meter DP4 is less than the specified value DP_L (step S19: Yes), and the regeneration process of the adsorption tower B is completed (step S20). As a result, the supply of hydrogen from the adsorption tower A to the adsorption tower B is stopped. The control device 30 starts the adsorption process of the adsorption tower A (step S21). Inside the PSA device 22, as shown in FIG. Figure 2 Hydrogen flows as indicated by the arrow in (a). In this case, the control device 30 starts supplying raw hydrogen (step S22). The supplied raw hydrogen gas is adjusted for moisture by the hydrogen supply device 14 and then supplied as hydrogen to the hydrogen booster stack 16. The control device 30 supplies the high-pressure hydrogen gas, which has been pressurized by the hydrogen booster stack 16, to the adsorption tower A.

[0109] The operation at time t9 is the same as the operation at time t1 (step S1 ), and the operation at time t10 is the same as the operation at time t2 , so detailed descriptions of the subsequent time points are omitted.

[0110] The following supplementary notes are further disclosed regarding the above-mentioned embodiment.

[0111] (Note 1) The electrochemical hydrogen boosting system (10) of the present invention comprises a hydrogen boosting stack (16), a power supply device (28), a hydrogen supply device (14) and a PSA device (22), wherein the hydrogen boosting stack comprises a single cell (32), the single cell comprising an electrolyte membrane (34), an anode electrode (36) arranged on one side of the electrolyte membrane and a cathode electrode (40) arranged on the other side of the electrolyte membrane, the hydrogen boosting stack supplies hydrogen to the anode electrode and discharges high-pressure hydrogen boosted by the cathode electrode; the power supply device applies voltage to the hydrogen boosting stack; the hydrogen supply device supplies hydrogen to the hydrogen boosting stack through a hydrogen supply flow channel (60); the PSA device comprises a plurality of adsorption towers (24) (adsorption tower A, adsorption tower B) for dehumidifying the high-pressure hydrogen discharged from the hydrogen boosting stack, and the electrochemical hydrogen boosting system comprises a return flow channel (94) for returning the regenerated hydrogen used for regenerating the adsorption tower to the hydrogen supply flow channel of the hydrogen boosting stack or the hydrogen supply device.

[0112] Thus, since the regenerated hydrogen used for regeneration is returned to the hydrogen supply channel or hydrogen supply device of the hydrogen booster stack through the return flow channel, the hydrogen is recycled within the electrochemical hydrogen booster system without being discharged externally. This improves hydrogen utilization efficiency and suppresses the reduction in hydrogen production efficiency of the electrochemical hydrogen booster system. Furthermore, since the hydrogen used for regenerating the adsorption tower is not discharged externally, no special discharge device is required, making the electrochemical hydrogen booster system simple and economical.

[0113] (Note 2) In the electrochemical hydrogen boosting system described in Note 1, the multiple adsorption towers (adsorption tower A, adsorption tower B) may include a treatment adsorption tower for dehumidifying hydrogen and a regeneration adsorption tower for discharging the adsorbed moisture. When the regeneration adsorption tower is regenerated, dehumidified hydrogen is supplied from the treatment adsorption tower to the regeneration adsorption tower, so that the moisture adsorbed by the regeneration adsorption tower is discharged, and the regeneration adsorption tower is regenerated.

[0114] This allows an adsorption tower whose adsorbent water content has reached its upper limit to be regenerated using dried hydrogen discharged from another adsorption tower in the PSA unit. This eliminates the need for specialized equipment for regenerating the adsorption tower, simplifying the structure of the electrochemical hydrogen boosting system and making it economical.

[0115] (Note 3) In the electrochemical hydrogen boosting system described in Note 1, the hydrogen boosting stack and the PSA device may be connected by a high-pressure hydrogen supply channel (70), and a gas-liquid separator (18) is provided on the high-pressure hydrogen supply channel.

[0116] This method effectively separates and removes liquid water from the high-pressure hydrogen gas before supplying it to the PSA unit. This reduces the amount of water removed by the PSA unit and prolongs the time it takes for the water content in the adsorption tower to reach its upper limit. This improves the adsorption tower's operating rate.

[0117] (Note 4) In the electrochemical hydrogen pressurizing system described in Supplement 1, a pressure reducing valve (96) for reducing the pressure of the circulating regenerated hydrogen gas may be provided on the return flow passage.

[0118] With this configuration, the pressure of the regenerated hydrogen gas supplied from the return flow path through the hydrogen supply device to the hydrogen booster stack can be adjusted, and hydrogen gas at an optimal pressure can be supplied to the hydrogen booster stack.

[0119] (Note 5) In the electrochemical hydrogen boosting system described in Note 1, a flow regulating valve (98) for adjusting the flow rate of the circulating regenerated hydrogen gas may be provided on the return flow channel, and the flow regulating valve adjusts the flow rate of the circulating regenerated hydrogen gas according to the internal pressure of the closed container (44) of the hydrogen supply device.

[0120] This allows an appropriate amount of regenerated hydrogen to be supplied to the hydrogen booster stack in accordance with the flow rate of high-pressure hydrogen discharged from the hydrogen booster stack, thereby optimizing the operation of the hydrogen booster stack.

[0121] (Note 6) In the electrochemical hydrogen pressure boosting system according to Supplementary Note 1, the hydrogen discharge port provided at the downstream end of the return flow path may open into liquid water stored in a sealed container included in the hydrogen supply device.

[0122] With this configuration, liquid droplets contained in the hydrogen gas supplied from the return flow path can be removed, and the humidity of the hydrogen gas supplied to the hydrogen booster stack can be well adjusted by the liquid water.

[0123] (Note 7) In the electrochemical hydrogen boosting system described in Note 2, when the water content of the adsorbent in the regeneration adsorption tower reaches an upper limit, dehumidified hydrogen is supplied from the treatment adsorption tower to the regeneration adsorption tower to start the regeneration process of the regeneration adsorption tower.

[0124] (Note 8) In the electrochemical hydrogen boosting system described in Note 7, when the water content of the adsorbent in the regeneration adsorption tower drops to a specified value, the supply of dehumidified hydrogen from the treatment adsorption tower to the regeneration adsorption tower is stopped, thereby completing the regeneration process of the regeneration adsorption tower.

[0125] (Note 9) In the electrochemical hydrogen pressure boosting system according to Supplementary Note 5, the flow rate regulating valve may adjust the flow rate of the regenerated hydrogen gas flowing inside the closed container so that the pressure of the space of the closed container is maintained at a predetermined value.

[0126] The present invention has been described in detail, but the present invention is not limited to the above-mentioned embodiments. These embodiments can be supplemented, replaced, changed, partially deleted, etc., without departing from the scope of the present invention or the scope of the present invention derived from the contents described in the technical solutions and their equivalents. In addition, these embodiments can also be implemented in combination. For example, in the above-mentioned embodiments, the steps of each action or each processing step are shown as an example and are not limited to these.

Claims

1. An electrochemical hydrogen boost system, characterized in that: It has a hydrogen booster stack, a power supply device, a hydrogen supply device and a PSA device, wherein: The hydrogen booster stack comprises a single cell, wherein the single cell comprises an electrolyte membrane, an anode electrode provided on one side of the electrolyte membrane, and a cathode electrode provided on the other side of the electrolyte membrane. The hydrogen booster stack supplies hydrogen to the anode electrode and discharges high-pressure hydrogen gas boosted by the cathode electrode. The power supply device applies voltage to the hydrogen booster stack; The hydrogen supply device supplies hydrogen to the hydrogen booster stack through a hydrogen supply flow channel; The PSA device has a plurality of adsorption towers for dehumidifying the high-pressure hydrogen discharged from the hydrogen booster stack. The electrochemical hydrogen boosting system includes a return flow path for returning the regenerated hydrogen gas used for regenerating the adsorption tower to the hydrogen supply flow path of the hydrogen boosting stack or the hydrogen supply device.

2. The electrochemical hydrogen boost system according to claim 1, characterized in that: The multiple adsorption towers include a treatment adsorption tower for dehumidifying hydrogen and a regeneration adsorption tower for discharging the adsorbed moisture. When the regeneration adsorption tower is regenerated, dehumidified hydrogen is supplied from the treatment adsorption tower to the regeneration adsorption tower, so that the moisture adsorbed by the regeneration adsorption tower is discharged and the regeneration adsorption tower is regenerated.

3. The electrochemical hydrogen boosting system according to claim 1, characterized in that: The hydrogen booster stack and the PSA device are connected by a high-pressure hydrogen supply channel, and a gas-liquid separator is provided on the high-pressure hydrogen supply channel.

4. The electrochemical hydrogen boost system according to claim 1, characterized in that: The return flow passage is provided with a pressure reducing valve for reducing the pressure of the circulating regenerated hydrogen gas.

5. The electrochemical hydrogen boosting system according to claim 1, characterized in that: The return flow passage is provided with a flow regulating valve for regulating the flow rate of the circulating regeneration hydrogen gas. The flow regulating valve regulates the flow rate of the circulating regeneration hydrogen gas according to the internal pressure of the closed container of the hydrogen supply device.

6. The electrochemical hydrogen boosting system according to claim 1, characterized in that: A hydrogen discharge port provided at the downstream end of the return flow channel opens into liquid water stored in a sealed container included in the hydrogen supply device.

7. The electrochemical hydrogen boosting system according to claim 2, characterized in that: When the water content of the adsorbent in the regeneration adsorption tower reaches an upper limit, dehumidified hydrogen is supplied from the treatment adsorption tower to the regeneration adsorption tower to start a regeneration step of the regeneration adsorption tower.

8. The electrochemical hydrogen boosting system according to claim 7, characterized in that: When the moisture content of the adsorbent in the regeneration adsorption tower decreases to a predetermined value, the supply of the dehumidified hydrogen from the treatment adsorption tower to the regeneration adsorption tower is stopped, thereby completing the regeneration process of the regeneration adsorption tower.

9. The electrochemical hydrogen boosting system according to claim 5, characterized in that: The flow rate regulating valve adjusts the flow rate of the regeneration hydrogen gas flowing inside the closed container so that the pressure of the space of the closed container is maintained at a predetermined value.

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