Electrolytic apparatus

Abstract

SOLUTION: An electrolytic apparatus 10 comprises: a water electrolysis stack 16 for electrolyzing water; a gas-liquid separator 14 for separating a hydrogen gas from the water discharged from the water electrolysis stack; and a hydrogen booster stack 22 for boosting the hydrogen gas separated by the gas-liquid separator. The gas-liquid separator includes a storage tank 40 for storing water, in which a maximum storage water level 100 that is the maximum value of water level allowable for the storage tank is predetermined. The hydrogen booster stack is located above the maximum storage water level.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to electrolysis devices. [Background technology]

[0002] In recent years, research and development into electrolysis devices has been conducted to contribute to energy efficiency, ensuring that more people have access to affordable, reliable, sustainable and advanced energy.

[0003] Japanese Patent Application Laid-Open Publication No. 2022-029892 discloses an electrolysis device including a water electrolysis stack that electrolyzes water, a gas-liquid separator that separates hydrogen gas from water discharged from the water electrolysis stack, and a hydrogen booster stack that boosts the hydrogen gas separated by the gas-liquid separator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-029892 Summary of the Invention [Problem to be solved by the invention]

[0005] A better electrolysis device is needed.

[0006] The present disclosure aims to solve the above-mentioned problems. [Means for solving the problem]

[0007] An aspect of the present disclosure is an electrolysis device comprising: a water electrolysis stack that electrolyzes water; a gas-liquid separator that separates hydrogen gas from water discharged from the water electrolysis stack; and a hydrogen booster stack that pressurizes the hydrogen gas separated by the gas-liquid separator, wherein the gas-liquid separator has a storage tank for storing water, a maximum storage water level that is the maximum water level that the storage tank can tolerate is predetermined, and the hydrogen booster stack is located above the maximum storage water level. [Effects of the Invention]

[0008] According to the present disclosure, a better electrolysis device can be obtained. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an electrolysis device. [Figure 2] FIG. 2 is a perspective view of the electrolysis device. [Figure 3] FIG. 3 is a plan view of the electrolysis device as seen from above. [Figure 4] FIG. 4 is a cross-sectional explanatory view of the electrolysis device, with some parts omitted. [Figure 5] FIG. 5 is an explanatory diagram of the inclined state of the electrolysis device. [Figure 6] FIG. 6 is an explanatory diagram of the inclined state of the electrolysis device. [Figure 7] FIG. 7 is a cross-sectional explanatory view, with some parts omitted, of an electrolysis device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] The gas-liquid separator of the electrolysis device has a storage tank for storing water. When such an electrolysis device is mounted on a mobile body, the electrolysis device may be tilted relative to a horizontal plane. When the electrolysis device is tilted relative to a horizontal plane, the water (liquid water) stored in the storage tank may flow into the hydrogen booster stack. In this case, water may accumulate inside the hydrogen booster stack, preventing the hydrogen booster stack from efficiently boosting hydrogen gas. The present disclosure can provide an electrolysis device that can suppress the inflow of water stored in the storage tank into the hydrogen booster stack and efficiently boost hydrogen gas.

[0011] 1 and 2 are perspective views of the electrolysis device 10. FIG. 3 is a plan view of the electrolysis device 10 as viewed from above. As shown in FIGS. 1 to 3, the electrolysis device 10 can be incorporated into, for example, a circulatory renewable energy system. The circulatory renewable energy system is a system that combines the electrolysis device 10 with a fuel cell system (not shown). The fuel cell system generates electricity and water through an electrochemical reaction between oxygen gas and hydrogen gas. The electrolysis device 10 electrolyzes water to generate oxygen gas and hydrogen gas. The electrolysis device 10 utilizes the water generated in the fuel cell system. The fuel cell system utilizes the oxygen gas and hydrogen gas generated in the electrolysis device 10.

[0012] Fig. 4 is a partially omitted cross-sectional explanatory view of the electrolysis device 10. As shown in Fig. 4, the electrolysis device 10 is mounted on a mobile body 200. The electrolysis device 10 can be used, for example, but is not limited to, for a probe for a planet outside the Earth. The mobile body 200 is, for example, a vehicle, an aircraft, or the like.

[0013] The electrolysis device 10 is formed as a single integrated module. The electrolysis device 10 is installed on an installation surface 202 of a mobile body 200. Fig. 4 shows a state in which the installation surface 202 on which the electrolysis device 10 is installed is horizontal (a state in which the electrolysis device 10 is not tilted). Figs. 5 and 6 are explanatory diagrams of an inclined state of the electrolysis device 10. As shown in Figs. 5 and 6, the installation surface 202 of the electrolysis device 10 may be inclined with respect to the horizontal plane depending on the attitude of the mobile body 200. In this case, the electrolysis device 10 is inclined with respect to the horizontal plane.

[0014] A maximum elevation / depression angle θa, which is the maximum allowable value of the elevation / depression angle θ (inclination angle with respect to the horizontal), is predetermined for the electrolysis device 10. That is, in this embodiment, the electrolysis device 10 can be operated when the elevation / depression angle θ is equal to or less than the maximum elevation / depression angle θa.

[0015] As shown in FIGS. 1 to 3 , the electrolysis device 10 includes a support member 12, a gas-liquid separator 14, a water electrolysis stack 16, a water supply flow path 18, a water discharge flow path 20, a hydrogen booster stack 22, a hydrogen gas supply flow path 24, and a hydrogen gas discharge flow path 26.

[0016] The support member 12 has a base portion 28, a plurality of casters 30, a first support portion 32, a second support portion 34, and a third support portion 36. The base portion 28 extends in the X and Y directions. The X direction is a direction perpendicular to the height direction (Z direction) of the electrolysis device 10. The Y direction is a direction perpendicular to the X and Z directions. When the electrolysis device 10 is not tilted, the X and Y directions are horizontal. Furthermore, when the electrolysis device 10 is not tilted, the Z direction, which is the height direction of the electrolysis device 10, is vertical.

[0017] As shown in Figures 1, 2 and 4, the casters 30 are attached to the underside (surface facing the Z1 direction) of the base 28. This allows the entire electrolysis device 10 to be easily positioned relative to the installation surface 202 of the movable body 200. The casters 30 have stoppers (not shown) for locking the rotation of the wheels. Note that the support member 12 does not necessarily have to be provided with the casters 30. In this case, the base 28 is installed directly on the installation surface 202 of the movable body 200.

[0018] As shown in FIGS. 1 to 3 , the first support part 32, the second support part 34, and the third support part 36 are attached to the base part 28. The first support part 32 supports the gas-liquid separator 14. The gas-liquid separator 14 can be attached to the first support part 32 by an attachment member (not shown). The second support part 34 supports the hydrogen booster stack 22. The third support part 36 supports the water electrolysis stack 16.

[0019] In this embodiment, the gas-liquid separator 14 and the hydrogen booster stack 22 are arranged side by side in the Y direction. The water electrolysis stack 16 and the hydrogen booster stack 22 are arranged side by side in the X direction. Specifically, the gas-liquid separator 14 is located in the Y1 direction relative to the hydrogen booster stack 22. In other words, the hydrogen booster stack 22 is located in the Y2 direction, which is the opposite direction to the Y1 direction, relative to the gas-liquid separator 14. The hydrogen booster stack 22 is located in the X1 direction relative to the water electrolysis stack 16. In other words, the water electrolysis stack 16 is located in the X2 direction, which is the opposite direction to the X1 direction, relative to the hydrogen booster stack 22.

[0020] Auxiliary equipment (not shown) may be attached to the base portion 28. The auxiliary equipment may include, for example, an ion exchanger, a heat exchanger, an on-off valve, piping, etc. The auxiliary equipment may be disposed, for example, in an empty space in the base portion 28 adjacent to the gas-liquid separator 14 in the X2 direction.

[0021] The arrangement of the gas-liquid separator 14, the water electrolysis stack 16, and the hydrogen booster stack 22 is not limited to the above example and can be set as appropriate. For example, the support member 12 does not need to have the third support portion 36. That is, the water electrolysis stack 16 may be disposed directly on the base portion 28.

[0022] 1 to 4, the gas-liquid separator 14 includes a gas-liquid separator main body 38 and a storage tank 40. The gas-liquid separator main body 38 separates the fluid (a mixed fluid of hydrogen gas and water) discharged from the water electrolysis stack 16 into gas and liquid. The gas-liquid separator main body 38 is formed, for example, in a cylindrical shape. The gas-liquid separator main body 38 extends in the Z direction.

[0023] The storage tank 40 stores water (liquid water). The storage tank 40 is provided below the gas-liquid separator main body 38. The interior of the storage tank 40 is in communication with the interior of the gas-liquid separator main body 38 (see FIG. 4). The storage tank 40 is formed, for example, in a cylindrical shape. The storage tank 40 can store water separated in the gas-liquid separator main body 38. Water may also be introduced into the storage tank 40 from the outside.

[0024] The gas-liquid separator 14 may include components other than those described above. The size, shape, etc. of the gas-liquid separator 14 can be set as appropriate.

[0025] A first power supply (not shown), which is a DC power supply, is connected to the water electrolysis stack 16. As shown in FIGS. 1 to 3, the water electrolysis stack 16 electrolyzes water by receiving a current from the DC power supply. As a result, the water electrolysis stack 16 generates hydrogen gas and oxygen gas. The water electrolysis stack 16 is, for example, a differential pressure water electrolysis stack capable of producing high-pressure oxygen gas. The water electrolysis stack 16 may also be an equal pressure water electrolysis stack.

[0026] 1 and 2, the water electrolysis stack 16 is formed, for example, in a cylindrical shape. The water electrolysis stack 16 includes a cell stack 42 and a pair of end plates 44. The cell stack 42 has a plurality of water electrolysis cells 46. The plurality of water electrolysis cells 46 are stacked in the Z direction.

[0027] Although detailed illustration is omitted, the water electrolysis cell 46 includes a membrane electrode assembly and a pair of separators. The membrane electrode assembly is sandwiched between the pair of separators in the Z direction. The membrane electrode assembly includes an electrolyte membrane, a cathode electrode, and an anode electrode. The electrolyte membrane is an ion exchange membrane. A voltage is applied between the cathode electrode and the anode electrode by a first power source.

[0028] The pair of end plates 44 sandwich the cell stack 42 in the Z direction. An oxygen gas pipe 48 is connected to the upper end plate 44 (in the Z2 direction) to transport oxygen gas generated in the water electrolysis stack 16 to the outside (for example, an oxygen gas tank not shown).

[0029] In order to lower the center of gravity of the electrolysis device 10, the lower surface of the water electrolysis stack 16 is located relatively close to the base portion .

[0030] 1 to 3, the water supply flow path 18 supplies water stored in the storage tank 40 to the water electrolysis stack 16. The water supply flow path 18 includes a water outlet 50, a first water supply pipe 52, a water pump 54, a second water supply pipe 56, and a water inlet 58.

[0031] The water outlet portion 50 is connected to the storage tank 40. A water outlet port (hole) (not shown) is formed in the water outlet portion 50 for leading water from the storage tank 40. The water outlet portion 50 protrudes in the Y2 direction from the storage tank 40. A first water supply pipe 52 connects the water outlet portion 50 to a water pump 54. The water pump 54 pumps water toward the water electrolysis stack 16. A second water supply pipe 56 connects the water pump 54 to a water inlet portion 58.

[0032] The water inlet 58 is connected to the water electrolysis stack 16. A water inlet port (hole) (not shown) is formed in the water inlet 58 for introducing water into the water electrolysis stack 16. The water inlet 58 is located in the center of the cell stack 42 in the up-down direction (see FIGS. 1 and 2). The water inlet 58 protrudes in the Y2 direction from the cell stack 42. This allows a portion of the second water supply pipe 56 to be positioned in the Y2 direction of the water electrolysis stack 16, and therefore the second water supply pipe 56 can protect the water electrolysis stack 16 from the Y2 direction (outside the electrolysis device 10).

[0033] 2 and 3 , the water discharge flow path 20 discharges the hydrogen gas generated in the water electrolysis stack 16 and unreacted water to the storage tank 40. The water discharge flow path 20 includes a first water outlet portion 60, a second water outlet portion 62, a drain pipe 64, and a water return portion 66.

[0034] The first water outlet portion 60 and the second water outlet portion 62 are connected to the water electrolysis stack 16. Each of the first water outlet portion 60 and the second water outlet portion 62 has a water outlet port (hole) (not shown) formed therein for allowing water to flow out from the inside of the water electrolysis stack 16. The first water outlet portion 60 is located at the lower end of the cell stack 42. The second water outlet portion 62 is located at the upper end of the cell stack 42. Each of the first water outlet portion 60 and the second water outlet portion 62 protrudes in the Y1 direction from the cell stack 42.

[0035] The drain pipe 64 guides the unreacted water and hydrogen gas guided from the first water outlet 60 and the second water outlet 62 to the water return section 66. The water return section 66 is connected to the storage tank 40. The water return section 66 is formed with a water return port (hole) (not shown) for returning the unreacted water and hydrogen gas discharged from the water electrolysis stack 16 to the inside of the storage tank 40 (gas-liquid separator 14).

[0036] A second power supply (not shown), which is a DC power supply, is connected to the hydrogen booster stack 22. As shown in Figures 1 to 4, the hydrogen booster stack 22 can boost the pressure of hydrogen gas by supplying current from the DC power supply.

[0037] The hydrogen booster stack 22 is formed, for example, in a cylindrical shape. The hydrogen booster stack 22 includes a cell stack 68 and a pair of end plates 70. The cell stack 68 has a plurality of booster cells 72. The plurality of booster cells 72 are stacked in the Z direction.

[0038] Although detailed illustration is omitted, the booster cell 72 has a membrane electrode assembly and a pair of separators. The membrane electrode assembly is sandwiched between the pair of separators in the Z direction. The membrane electrode assembly includes an electrolyte membrane, a cathode electrode, and an anode electrode. The electrolyte membrane is an ion exchange membrane. A voltage is applied between the cathode electrode and the anode electrode by a second power source.

[0039] A pair of end plates 70 sandwich the cell stack 68 in the Z direction. A hydrogen gas pipe 74 is connected to the upper end plate 70 to transport the hydrogen gas generated in the hydrogen booster stack 22 for boosting pressure to the outside (for example, a hydrogen gas tank not shown).

[0040] 1 and 2, the height position of the lower surface of the hydrogen booster stack 22 is higher than the height position of the lower surface of the water electrolysis stack 16. The height position of the lower surface of the hydrogen booster stack 22 is lower than the height position of the upper surface of the water electrolysis stack 16. The height position of the upper surface of the hydrogen booster stack 22 is higher than the height position of the upper surface of the water electrolysis stack 16. In other words, when the electrolysis device 10 is not tilted, the vertical height position of the upper surface (upper end) of the water electrolysis stack 16 is lower than the vertical height position of the upper surface (upper end) of the hydrogen booster stack 22.

[0041] As shown in FIGS. 1 to 4, the hydrogen gas supply flow path 24 supplies hydrogen gas from the gas-liquid separator 14 to the hydrogen booster stack 22. The hydrogen gas supplied from the gas-liquid separator 14 to the hydrogen booster stack 22 contains a moderate amount of moisture. This moisture humidifies the electrolyte membrane of the booster cell 72. The hydrogen gas supply flow path 24 includes a hydrogen gas outlet 76, a first hydrogen gas supply pipe 78, a hydrogen pump 80, a second hydrogen gas supply pipe 82, and a hydrogen gas inlet 84.

[0042] The hydrogen gas outlet 76 is connected to the gas-liquid separator main body 38. A hydrogen gas outlet port 86 (hole) for guiding hydrogen gas from the gas-liquid separator main body 38 is formed in the hydrogen gas outlet 76 (see FIG. 4). The hydrogen gas outlet 76 protrudes in the Y2 direction from the gas-liquid separator main body 38. The height of the hydrogen gas outlet 76 is lower than the height of the lower surface of the hydrogen booster stack 22.

[0043] The first hydrogen gas supply pipe 78 connects the hydrogen gas outlet 76 and the hydrogen pump 80. When the electrolysis device 10 is not tilted, the first hydrogen gas supply pipe 78 rises from the hydrogen gas outlet 76 to the hydrogen pump 80 without descending. In other words, when the electrolysis device 10 is not tilted, the first hydrogen gas supply pipe 78 descends from the hydrogen pump 80 to the hydrogen gas outlet 76 without ascending. This allows water droplets condensed on the inner surface of the first hydrogen gas supply pipe 78 to flow by gravity to the gas-liquid separator body 38. The hydrogen pump 80 pumps hydrogen gas toward the hydrogen booster stack 22. Although not shown in detail, the hydrogen pump 80 may be supported by a support member 12. The height of the hydrogen pump 80 is higher than the height of the hydrogen gas outlet 76.

[0044] The second hydrogen gas supply pipe 82 connects the hydrogen pump 80 and the hydrogen gas inlet 84. When the electrolysis device 10 is not tilted, the second hydrogen gas supply pipe 82 rises from the hydrogen pump 80 to the hydrogen gas inlet 84 without descending. In other words, when the electrolysis device 10 is not tilted, the second hydrogen gas supply pipe 82 descends from the hydrogen gas inlet 84 to the hydrogen pump 80 without ascending. This allows water droplets condensed on the inner surface of the second hydrogen gas supply pipe 82 to flow by gravity through the hydrogen pump 80 and the first hydrogen gas supply pipe 78 to the gas-liquid separator body 38. This prevents condensed water from being introduced into the hydrogen booster stack 22 from the hydrogen gas supply flow path 24.

[0045] The hydrogen gas inlet portion 84 is connected to the hydrogen booster stack 22. A hydrogen gas inlet port (hole) (not shown) is formed in the hydrogen gas inlet portion 84 for introducing hydrogen gas into the hydrogen booster stack 22. The hydrogen gas inlet portion 84 is located in the center of the cell stack 68 in the up-down direction. The hydrogen gas inlet portion 84 protrudes in the Y1 direction from the cell stack 68. As shown in Figures 1, 2, and 4, the height of the hydrogen gas inlet portion 84 is higher than the height of the hydrogen pump 80. The height of the hydrogen gas inlet portion 84 is higher than the height of the hydrogen gas outlet portion 76.

[0046] As shown in FIGS. 1 to 4 , the hydrogen gas discharge flow path 26 returns unreacted hydrogen gas and excess moisture that did not react in the hydrogen booster stack 22 to the gas-liquid separator 14. The hydrogen gas discharge flow path 26 includes a hydrogen gas outlet portion 88, a hydrogen gas lead-out pipe 90, and a hydrogen gas return portion 92. The hydrogen gas outlet portion 88 is connected to the hydrogen booster stack 22. A hydrogen gas outlet port (hole) (not shown) is formed in the hydrogen gas outlet portion 88 for leading out the unreacted hydrogen gas and excess moisture. The hydrogen gas outlet portion 88 is located at the lower end of the cell stack 68. The hydrogen gas outlet portion 88 protrudes in the Y2 direction from the cell stack 68. This allows a portion of the hydrogen gas lead-out pipe 90 connected to the hydrogen gas outlet portion 88 to be positioned in the Y2 direction of the hydrogen booster stack 22, thereby protecting the hydrogen booster stack 22 from the Y2 direction (outside the electrolysis device 10) by the hydrogen gas lead-out pipe 90. The hydrogen gas outlet portion 88 is located lower in the height direction than the hydrogen gas inlet portion 84 (see FIGS. 1, 2 and 4).

[0047] The hydrogen gas outlet pipe 90 connects the hydrogen gas outlet portion 88 and the hydrogen gas return portion 92. When the electrolysis device 10 is not tilted, the hydrogen gas outlet pipe 90 descends from the hydrogen gas outlet portion 88 to the hydrogen gas return portion 92 without ascending. In other words, when the electrolysis device 10 is not tilted, the hydrogen gas outlet pipe 90 ascends from the hydrogen gas return portion 92 to the hydrogen gas outlet portion 88 without descending. This allows water droplets that condense on the inner surface of the hydrogen gas outlet pipe 90 to flow by gravity to the gas-liquid separator body 38.

[0048] The hydrogen gas return section 92 is connected to the gas-liquid separator main body 38. A hydrogen gas return port 94 (hole) is formed in the hydrogen gas return section 92 to return unreacted hydrogen gas and excess moisture introduced by the hydrogen gas outlet pipe 90 to the inside of the gas-liquid separator 14. As shown in FIGS. 1, 2, and 4, the height of the hydrogen gas return section 92 is lower than the height of the hydrogen gas outlet section 88. The height of the hydrogen gas return section 92 is also lower than the height of the hydrogen gas outlet section 76. In other words, the height of the hydrogen gas outlet port 86 is higher than the height of the hydrogen gas return port 94 (see FIG. 4).

[0049] As shown in Fig. 4, in this embodiment, the electrolysis device 10 includes a pipe 96 that connects the gas-liquid separator 14 and the hydrogen booster stack 22. The pipe 96 includes a first hydrogen gas supply pipe 78, a second hydrogen gas supply pipe 82, and a hydrogen gas outlet pipe 90. When the electrolysis device 10 is not tilted, the pipe 96 ascends without descending from the gas-liquid separator 14 toward the hydrogen booster stack 22. In this embodiment, the storage tank 40 is provided with a hydrogen flow path port 98. The hydrogen flow path port 98 includes a hydrogen gas outlet port 86 and a hydrogen gas return port 94.

[0050] In this embodiment, a maximum storage water level 100, which is the maximum water level that the storage tank 40 can tolerate, is determined in advance. FIG. 4 shows a state in which water is stored in the storage tank 40 up to the maximum storage water level 100. The hydrogen pressurization stack 22 is located above the maximum storage water level 100. Specifically, the bottom surface of the hydrogen pressurization stack 22 is located above the maximum storage water level 100. That is, the hydrogen gas inlet 84 and the hydrogen gas outlet 88 are each located above the maximum storage water level 100.

[0051] The hydrogen gas return port 94 is located above the maximum stored water level 100. This prevents water stored in the storage tank 40 from flowing from the hydrogen gas return port 94 into the hydrogen gas return section 92 and clogging or narrowing the flow path of the hydrogen gas return section 92. This allows unreacted hydrogen gas and water to be smoothly discharged from the hydrogen booster stack 22, thereby preventing water from accumulating inside the hydrogen booster stack 22.

[0052] When the electrolysis device 10 is not tilted, the hydrogen flow path port 98 is located above the maximum stored water level 100. Specifically, as shown in Fig. 5 , even when the electrolysis device 10 is tilted downward in the Y2 direction at the maximum elevation / depression angle θa with the storage tank 40 filled with water up to the maximum stored water level 100, the height position of the hydrogen flow path port 98 in the vertical direction is higher than the position of the upper end of the maximum stored water level 100 of the storage tank 40 in the vertical direction.

[0053] 6 , even when the electrolysis device 10, in which the storage tank 40 is filled with water up to the maximum storage water level 100, is tilted downward in the Y1 direction to the maximum elevation / depression angle θa, the height position in the vertical direction of the hydrogen flow path port 98 is higher than the position of the upper end in the vertical direction of the maximum storage water level 100 of the storage tank 40. This makes it possible to prevent the water stored in the storage tank 40 from flowing into the pipe 96, even when the electrolysis device 10, in which the storage tank 40 is filled with water up to the maximum storage water level 100, is tilted.

[0054] 3 , in this embodiment, the distance L1 between the gas-liquid separator 14 and the hydrogen booster stack 22 is shorter than the distance L2 between the gas-liquid separator 14 and the water electrolysis stack 16. The distance L1 is the shortest distance between the axis Ax1 of the gas-liquid separator 14 and the axis Ax2 of the hydrogen booster stack 22. The distance L2 is the shortest distance between the axis Ax1 of the gas-liquid separator 14 and the axis Ax3 of the water electrolysis stack 16.

[0055] As shown in Fig. 4, the electrolysis device 10 becomes larger as the distance L1 increases. Furthermore, the heightwise positions of the hydrogen gas inlet section 84 and the hydrogen gas outlet section 88 become higher as the distance L1 increases. In other words, the longer the distance L1, the greater the distance from the base section 28 to the hydrogen booster stack 22 must be, and therefore the heightwise dimension of the electrolysis device 10 increases and the position of the center of gravity of the electrolysis device 10 becomes higher. When the distance L1 is shorter than the distance L2, as in the present embodiment, the electrolysis device 10 can be configured to be relatively compact and the position of the center of gravity of the electrolysis device 10 can be lowered.

[0056] Next, a brief description will be given of the operation of the electrolysis device 10. In the electrolysis device 10, when the water pump 54 is driven, water stored in the storage tank 40 is supplied to the water electrolysis stack 16 via the water supply flow path 18. In the water electrolysis stack 16, water is electrolyzed by the supply of current from the first power source, generating oxygen gas and hydrogen gas. The oxygen gas generated in the water electrolysis stack 16 is transported to the outside via the oxygen gas pipe 48. The hydrogen gas generated in the water electrolysis stack 16 and unreacted water are guided to the gas-liquid separator 14 via the water discharge flow path 20. The gas-liquid separator 14 separates the hydrogen gas from the water.

[0057] Furthermore, when the hydrogen pump 80 is driven, the hydrogen gas in the gas-liquid separator 14, together with an appropriate amount of moisture, is guided to the anode electrode of the hydrogen booster stack 22 via the hydrogen gas supply passage 24. In the hydrogen booster stack 22, hydrogen gas is generated at the cathode electrode when a current is supplied from the second electrode. The hydrogen gas generated at the cathode electrode is transported to the outside via the hydrogen gas pipe 74. Unreacted hydrogen gas and excess moisture that did not react in the hydrogen booster stack 22 are returned to the gas-liquid separator 14 via the hydrogen gas discharge passage 26.

[0058] According to this embodiment, the hydrogen booster stack 22 is located above the maximum storage water level 100, and therefore water stored in the storage tank 40 can be prevented from flowing into the hydrogen booster stack 22. This prevents water stored in the storage tank 40 from flowing into the hydrogen booster stack 22 and accumulating inside the hydrogen booster stack 22. Therefore, hydrogen gas can be efficiently boosted by the hydrogen booster stack 22. Therefore, a better electrolysis device 10 can be obtained.

[0059] FIG. 7 is a partially omitted cross-sectional explanatory view of an electrolysis device 10 according to a modified example. As shown in FIG. 7, the electrolysis device 10 may include a gas-liquid separator 14a instead of the above-described gas-liquid separator 14. The gas-liquid separator 14a has a gas-liquid separator main body 38a and a storage tank 40a. At least a portion of the gas-liquid separator 14a is located below (in the Z1 direction) the hydrogen booster stack 22. In this modified example, a portion of the gas-liquid separator main body 38a and a portion of the storage tank 40a are located below the hydrogen booster stack 22. In this case, for example, the hydrogen gas return section 92 can be disposed relatively close to the hydrogen gas outlet section 88, thereby shortening the length of the hydrogen gas outlet pipe 90. This allows the electrolysis device 10 to be configured more compactly.

[0060] The following additional notes are further disclosed regarding the above embodiment.

[0061] (Appendix 1) The electrolysis device (10) of the present disclosure includes a water electrolysis stack (16) that electrolyzes water, a gas-liquid separator (14, 14a) that separates hydrogen gas from water discharged from the water electrolysis stack, and a hydrogen booster stack (22) that pressurizes the hydrogen gas separated by the gas-liquid separator, wherein the gas-liquid separator has a storage tank (40, 40a) that stores water, and a maximum storage water level (100) that is the maximum water level that the storage tank can tolerate is predetermined, and the hydrogen booster stack is located above the maximum storage water level.

[0062] This configuration can prevent water stored in the storage tank from flowing into the hydrogen booster stack. This prevents water stored in the storage tank from flowing into the hydrogen booster stack and accumulating inside the hydrogen booster stack. This allows the hydrogen gas to be efficiently boosted by the hydrogen booster stack. This results in a better electrolysis device.

[0063] (Appendix 2) In the electrolysis apparatus described in Appendix 1, the hydrogen booster stack is provided with a hydrogen gas inlet (84) for introducing hydrogen gas into the hydrogen booster stack and a hydrogen gas outlet (88) for discharging unreacted hydrogen gas from the hydrogen booster stack, and the hydrogen gas inlet and the hydrogen gas outlet may be located above the maximum stored water level.

[0064] With this configuration, it is possible to prevent water stored in the storage tank from flowing into the hydrogen gas inlet and the hydrogen gas outlet.

[0065] (Appendix 3) In the electrolysis apparatus according to Supplementary Note 2, the gas-liquid separator may be provided with a hydrogen gas return port (94) for returning unreacted hydrogen gas and water, which have been led out from the hydrogen gas outlet port, to the inside of the gas-liquid separator, and the hydrogen gas return port may be located above the maximum stored water level.

[0066] This configuration prevents water stored in the storage tank from flowing from the hydrogen gas return port into the piping connecting the hydrogen gas outlet and the hydrogen gas return port, thereby preventing the flow path of the piping from being blocked or narrowed. This allows unreacted hydrogen gas and water to be smoothly discharged from the hydrogen booster stack, further preventing water from accumulating inside the hydrogen booster stack. Note that the water is mainly generated by condensation due to a drop in the temperature of the wet gas when the hydrogen booster stack is stopped.

[0067] (Appendix 4) In the electrolysis apparatus described in Appendix 1, a maximum elevation / depression angle (θa), which is a maximum allowable value of the elevation / depression angle (θ), is predetermined for the electrolysis apparatus, and even when the electrolysis apparatus is tilted to the maximum elevation / depression angle with the storage tank filled with water up to the maximum storage water level, the vertical height position of the hydrogen flow path port (98) provided in the storage tank may be higher than the maximum storage water level of the storage tank.

[0068] With this configuration, even when the electrolysis device is tilted to the maximum elevation / depression angle, the water stored in the storage tank can be prevented from flowing into the hydrogen flow path port.

[0069] (Appendix 5) In the electrolysis device according to Supplementary Note 1, a distance (L1) between the gas-liquid separator and the hydrogen boosting stack may be shorter than a distance (L2) between the gas-liquid separator and the water electrolysis stack.

[0070] With this configuration, the distance between the gas-liquid separator and the hydrogen pressurization stack can be made relatively short, and the height positions of the hydrogen gas inlet and outlet can be made low, thereby enabling the electrolysis device to be made compact and the center of gravity of the electrolysis device to be lowered.

[0071] (Appendix 6) In the electrolysis apparatus according to Supplementary Note 1, the pipe (96) connecting the gas-liquid separator and the hydrogen booster stack may rise, without descending, from the gas-liquid separator toward the hydrogen booster stack when the electrolysis apparatus is not tilted.

[0072] With this configuration, water droplets condensed on the inner surface of the piping can be guided to the gas-liquid separator by gravity. Furthermore, even if water stored in the storage tank flows into the piping when the electrolysis device is tilted, the water in the piping can be returned to the gas-liquid separator when the electrolysis device is returned to its normal position.

[0073] (Appendix 7) In the electrolysis apparatus according to Supplementary Note 1, at least a portion of the gas-liquid separator may be located below the hydrogen boosting stack.

[0074] With this configuration, the electrolysis device can be made even more compact.

[0075] (Appendix 8) In the electrolysis apparatus according to Supplementary Note 1, when the electrolysis apparatus is not tilted, a vertical height position of an upper end of the water electrolysis stack may be lower than a vertical height position of an upper end of the hydrogen boosting stack.

[0076] According to this configuration, the water electrolysis stack is disposed at a relatively low position, so that the center of gravity of the electrolysis device can be lowered.

[0077] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0078] 10... Electrolyzer 14, 14a... Gas-liquid separator 16...Water electrolysis stack 22...Hydrogen booster stack 40, 40a... Storage tank 84... Hydrogen gas inlet 88...Hydrogen gas outlet 96...Piping 98...Hydrogen flow outlet 100...Maximum storage water level L1, L2…distance θ…elevation / depression angle θa…Maximum elevation and depression angle

Claims

1. a water electrolysis stack that electrolyzes water; a gas-liquid separator that separates hydrogen gas from water discharged from the water electrolysis stack; a hydrogen pressurization stack that pressurizes the hydrogen gas separated by the gas-liquid separator; and Equipped with the gas-liquid separator has a storage tank for storing water, a maximum storage water level that is a maximum value of the water level that the storage tank can tolerate is determined in advance; The electrolysis device, wherein the hydrogen boosting stack is located above the maximum storage water level.

2. 2. The electrolysis device according to claim 1, The hydrogen boosting stack includes: a hydrogen gas inlet for introducing hydrogen gas into the hydrogen boosting stack; a hydrogen gas outlet portion for discharging unreacted hydrogen gas from the inside of the hydrogen boosting stack; is established, The electrolysis device, wherein the hydrogen gas inlet and the hydrogen gas outlet are located above the maximum stored water level.

3. 3. The electrolysis device according to claim 2, the gas-liquid separator is provided with a hydrogen gas return port for returning the unreacted hydrogen gas and water led out from the hydrogen gas outlet portion to the inside of the gas-liquid separator, The electrolysis device, wherein the hydrogen gas return port is located above the maximum storage water level.

4. 2. The electrolysis device according to claim 1, a maximum allowable value of the elevation / depression angle is predetermined for the electrolysis device; an electrolysis device, wherein even when the electrolysis device is tilted to the maximum elevation / depression angle with the storage tank filled with water up to the maximum storage water level, the vertical height position of the hydrogen flow path port provided in the storage tank is higher than the maximum storage water level in the storage tank.

5. 2. The electrolysis device according to claim 1, an electrolysis device, wherein the distance between the gas-liquid separator and the hydrogen boosting stack is shorter than the distance between the gas-liquid separator and the water electrolysis stack.

6. 2. The electrolysis device according to claim 1, an electrolysis device, wherein a pipe connecting the gas-liquid separator and the hydrogen booster stack rises without descending from the gas-liquid separator toward the hydrogen booster stack when the electrolysis device is not tilted.

7. 2. The electrolysis device according to claim 1, an electrolysis device, wherein at least a portion of the gas-liquid separator is located below the hydrogen boosting stack;

8. 2. The electrolysis device according to claim 1, an electrolysis device, wherein, when the electrolysis device is not tilted, a height position in the vertical direction of an upper end of the water electrolysis stack is lower than a height position in the vertical direction of an upper end of the hydrogen boosting stack.

Images