Gas-liquid separation device and gas-liquid separation method

Abstract

To provide a technology capable of realizing the downsizing of a device.SOLUTION: A gas-liquid separation device 1 separating a liquid and a gas from a gas-liquid mixed phase fluid includes: a hydrophobic partition wall part for the mixed phase fluid formed with a hydrophobic membrane 53 permeating only the gas in the mixed phase fluid; and a fluid passage 400 supplying the mixed phase fluid to the hydrophobic partition wall part.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to techniques for separating liquid and gas from a multiphase fluid. [Background technology]

[0002] A gas-liquid separator disclosed in Patent Document 1 below has been known as a conventional gas-liquid separator for separating gas and liquid from a multiphase fluid. The gas-liquid separator disclosed in this document has a swirl vane disposed in an annular space formed by a main body and an exhaust pipe. The upper end of the annular space is connected to an inlet, and the upper end of the annular space is connected to an outlet through a hole inside the exhaust pipe. A swirl chamber is formed below the annular space, and a liquid reservoir chamber is formed below the swirl chamber. A gap for liquid passage is formed between the outer periphery of the partition member and the inner circumferential wall of the casing. In this gas-liquid separator, the multiphase fluid entering through the inlet is swirled by the swirl vane, and the liquid is swung outward by centrifugal force and separated, then flows down along the inner circumferential wall of the main body and enters the liquid reservoir chamber through the gap. Meanwhile, gas that passes through the lower end of the exhaust pipe flows out through the outlet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-028422 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned gas-liquid separator requires an annular space in which swirl vanes are provided, a swirl chamber, a liquid reservoir chamber, etc., and therefore has a problem in that the size of the apparatus is large.

[0005] The problem to be solved by the present invention is to provide a technique that can realize the miniaturization of the device. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, one aspect of the present invention is a gas-liquid separation device that separates a liquid and a gas from a gas-liquid multiphase fluid, and is characterized by comprising: a hydrophobic partition wall portion for the multiphase fluid formed by a hydrophobic membrane that allows only the gas in the multiphase fluid to pass through; and a supply path that supplies the multiphase fluid to the hydrophobic partition wall portion.

[0007] Another aspect of the present invention is an electrolysis device that generates gas by electrolyzing a liquid supplied to an electrolyte membrane between an anode electrode section and a cathode electrode section, and is characterized by comprising: a liquid supply chamber in which the cathode electrode section is disposed and to which the liquid is supplied; a hydrophobic membrane that forms a partition wall of part of the liquid supply chamber and that allows permeation of only gas generated on the cathode side of the electrolyte membrane by the electrolysis; and a discharge path that discharges the gas that has permeated the hydrophobic membrane to the outside. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a gas-liquid separation device according to a first embodiment. [Figure 2] 1 is a front view showing a gas-liquid separation device according to a first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA shown in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along line BB shown in FIG. 2. [Figure 5] 1 is a schematic diagram illustrating the internal configuration and fluid flow of a gas-liquid separation device according to a first embodiment. FIG. [Figure 6] FIG. 4 is a perspective view showing a water electrolysis apparatus according to a second embodiment. [Figure 7] FIG. 1 is a perspective view showing a unit electrolytic cell according to a second embodiment. [Figure 8] FIG. 1 is a front view showing a unit electrolytic cell according to a second embodiment. [Figure 9] FIG. 10 is a right side view showing a unit electrolytic cell according to a second embodiment. [Figure 10] FIG. 10 is a left side view showing a unit electrolytic cell according to a second embodiment. [Figure 11]FIG. 10 is an exploded side view showing the configuration of a unit electrolytic cell according to a second embodiment. [Figure 12] FIG. 10 is a schematic diagram illustrating the internal configuration and fluid flow of an electrolysis cell according to a second embodiment. [Figure 13] FIG. 2 is a schematic diagram illustrating the internal configuration and fluid flow of a water electrolysis cell according to a first modified example. [Figure 14] FIG. 10 is a schematic diagram illustrating the internal configuration and fluid flow of a water electrolysis cell according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, components having substantially the same functions are designated by the same reference numerals, and redundant description will be omitted.

[0010] (First embodiment) The configuration of a gas-liquid separation device according to this embodiment will be described. The gas-liquid separator according to this embodiment will be described below assuming that the multiphase fluid to be separated is a gas-liquid two-phase fluid in which a liquid such as water and a gas (bubbles) such as air or water vapor are mixed. Figures 1 and 2 are a perspective view and a front view showing the gas-liquid separation device according to this embodiment. Figures 3 and 4 are cross-sectional views taken along lines AA and BB in Figure 2.

[0011] As shown in Fig. 1, the gas-liquid separation device 1 according to this embodiment includes a liquid-side plate 20 located on the front side of the device, a gas-side plate 30 located on the rear side, and a gas-liquid mixing plate 40 located between these plates and connected to each other, each of which is formed in a substantially disk shape. The plates are stacked on top of each other and fastened together with fasteners such as bolts and nuts, thereby being connected together as a single unit. By connecting these plates together as a single unit, flow paths are formed between the plates through which the multiphase fluid, the liquid separated from the multiphase fluid, and the gas separated from the multiphase fluid each flow separately. The flow paths will be described in detail below.

[0012] 1 and 2, the liquid side plate 20 has two supply / discharge pipes 41a, 41b, one liquid discharge pipe 21, and one gas discharge pipe 31 provided on its flat surface edge. Hereinafter, when there is no need to distinguish between these, they will be referred to as pipe sections. Each pipe section is formed in a substantially cylindrical shape that protrudes out of the surface of the liquid side plate 20, and in this embodiment, they are arranged in the following order clockwise when viewed from the front: supply / discharge pipe 41a, gas discharge pipe 31, supply / discharge pipe 41b, liquid discharge pipe 21, at equal intervals in the circumferential direction.

[0013] 3 and 4, the gas side plate 30 is provided with two supply and discharge pipes 41a, 41b, one liquid discharge pipe 21, and one gas discharge pipe 31 on its flat rear edge. These pipes are the same type as the pipes on the liquid side plate 20 and are provided on the rear side of the pipes on the liquid side plate 20. The same type of pipes located at corresponding positions on the front and rear sides of the gas-liquid separation device 1, i.e., on the liquid side plate 20 and the gas side plate 30, may be used in pairs, or either one may be used alone.

[0014] The pair of supply and discharge pipes 41a and the pair of supply and discharge pipes 41b are each connected to a fluid flow path 400 (see FIG. 5) described below, and supply and discharge the multiphase fluid into and from the inside of the device. These pipes are used, for example, by being connected to a pump (not shown) that supplies the multiphase fluid. In this embodiment, the multiphase fluid is supplied from both the supply and discharge pipes 41a and 41b, and gas and liquid separation is performed inside the device. Note that when the multiphase fluid is supplied into the device only from the supply and discharge pipe 41a, the multiphase fluid may be discharged from the supply and discharge pipe 41b and circulated, or vice versa. The multiphase fluid may also be supplied from one of the supply and discharge pipes 41a and 41b, and the other may be blocked.

[0015] The pair of liquid discharge pipes 21 each communicate with a liquid flow path 200 (see FIG. 5) described below in the gas-liquid separation device 1, and discharge the liquid separated from the multiphase fluid to the outside of the device. The pair of gas discharge pipes 31 each communicate with a gas flow path 300 (see FIG. 5) described below in the gas-liquid separation device 1, and discharge the gas separated from the multiphase fluid to the outside of the device. The discharged liquid and gas are each recovered in a container or the like provided outside the gas-liquid separation device 1.

[0016] (Internal configuration of gas-liquid separation device 1) The internal configuration of the flow paths and the like formed in the gas-liquid separation device 1 will be described in detail below with reference to Fig. 5. Fig. 5 is a schematic diagram for explaining the internal configuration and fluid flow of the gas-liquid separation device according to this embodiment. In the following description, the direction toward the front side of the gas-liquid separation device 1 will be referred to as the front, and the direction toward the back side will be referred to as the rear.

[0017] 5, a pair of disk-shaped partition walls 401a, 401b are provided in the gas-liquid mixing plate 40, spaced apart from each other and parallel to each other. A fluid flow path 400 is defined between the pair of partition walls 401a, 401b. The pair of partition walls 401a, 401b are provided with a plurality of through-holes (not shown) through which the multiphase fluid passes. Inflow chambers 402, 403 into which the multiphase fluid can flow from the through-holes are defined between the partition wall 401a and the liquid-side plate 20, and between the partition wall 401b and the gas-side plate 30, respectively.

[0018] The inflow chamber 402 is in contact at its front side with one surface of a disk-shaped hydrophilic membrane 52 fixed by a separator (not shown) or the like provided between the liquid side plate 20 and the gas-liquid mixing plate 40. Therefore, the inflow chamber 402 functions as a supply channel for supplying the multiphase fluid to the hydrophilic membrane 52 together with the fluid flow path 400.

[0019] The hydrophilic membrane 52 is a porous thin film made of a highly hydrophilic material that forms one wall surface of the inflow chamber 402, thereby forming a hydrophilic partition wall for the multiphase fluid. For this reason, in this embodiment, the hydrophilic membrane 52 is permeable (permeates) only with the liquid in the multiphase fluid when wet. As such, a known hydrophilic membrane 52 that allows only the liquid to pass through can be used.

[0020] A liquid flow path 200 is formed in the liquid-side plate 20 on the front side of the hydrophilic membrane 52, through which the liquid that has permeated the hydrophilic membrane 52, i.e., the liquid from which gas has been separated from the multiphase fluid, flows and through which the liquid is discharged to the outside. In other words, the hydrophilic membrane 52 forms one wall surface of the liquid flow path 200.

[0021] The rear side of the inflow chamber 403 contacts one surface of a disk-sheet-shaped hydrophobic membrane 53 fixed by a separator (not shown) or the like provided between the gas-side plate 30 and the gas-liquid mixing plate 40. Therefore, the inflow chamber 403 functions as a supply channel for supplying the multiphase fluid to the hydrophobic membrane 53 together with the fluid flow path 400.

[0022] The hydrophobic membrane 53 is a gas-permeable porous thin film that forms one wall surface of the inlet chamber 403, thereby forming a hydrophobic partition wall for the multiphase fluid. Therefore, in this embodiment, the hydrophobic membrane 53 allows only the gas in the multiphase fluid to pass through, while preventing the liquid from passing through. Known hydrophobic membranes can be used as the hydrophobic membrane 53. For example, Gore-Tex (registered trademark) manufactured by WL Gore & Associates, Inc., is made of ePTFE (expanded polytetrafluoroethylene). The type of hydrophobic membrane 53 can be appropriately selected depending on the usage environment, and may be either an organic membrane or an inorganic membrane. Examples of inorganic membranes include ceramic membranes such as zeolite membranes, silica membranes, alumina membranes, zirconia membranes, and titania membranes, as well as carbon membranes. Examples of organic membranes include fluororesin membranes such as PTFE (polytetrafluoroethylene) membranes and PVDF (polyvinylidene fluoride) membranes, and polymer membranes such as polyamide membranes, cellulose acetate membranes, polyimide membranes, and polyethylene membranes. The porous material may be made water-repellent and used as a hydrophobic membrane.

[0023] A gas flow path 300 is formed in the gas side plate 30 on the rear side of the hydrophobic membrane 53, through which gas that has permeated the hydrophobic membrane 53, i.e., gas in which liquid has been separated from the multiphase fluid, flows and through which the gas is discharged to the outside.

[0024] The hydrophilic membrane 52 and the hydrophobic membrane 53 are formed in sheet shapes and are spaced apart from each other with their faces facing each other. The distance between them is preferably equal to or less than a predetermined distance. The distance is based on the size of bubbles contained in the multiphase fluid. By setting the distance equal to or less than the size of the bubbles, gas bubbles contained in the multiphase fluid can come into contact with both the hydrophilic membrane 52 and the hydrophobic membrane 53, allowing the gas to quickly permeate into the gas flow path 300. Such a distance is preferably about 1 mm, which allows the multiphase fluid and bubbles to come into contact with the hydrophobic membrane 53. Therefore, the fluid flow path 400 may be formed by the hydrophilic membrane 52 and the hydrophobic membrane 53, excluding the partition walls 401a and 401b. That is, the front sidewall surface forming the fluid flow path 400 is the hydrophilic membrane 52, and the rear sidewall surface is the hydrophobic membrane 53. When the multiphase fluid is primarily composed of gas and includes droplets such as water droplets, the distance is preferably based on the size of the droplets contained in the multiphase fluid. By setting the separation distance to be equal to or smaller than the droplet size, the droplets contained in the multiphase fluid can come into contact with both the hydrophilic membrane 52 and the hydrophobic membrane 53, allowing the liquid to quickly permeate into the liquid flow path 200.

[0025] Furthermore, it is preferable that the pore size and the number of pores per unit area of ​​the hydrophilic membrane 52 and the hydrophobic membrane 53 are appropriately set depending on the type of gas and liquid to be separated, the supply pressure of the multiphase fluid, and the like.

[0026] (device operation) The operation of the gas-liquid separation device 1 according to this embodiment will be described below. Here, an example will be shown in which a multiphase fluid is supplied to each of the pair of supply and discharge pipes 41a and 41b. First, when the multiphase fluid is supplied to the pair of supply and discharge pipes 41a and 41b, the multiphase fluid flows into the fluid flow path 400, which communicates with the supply and discharge pipe 41a. The hatched arrows indicated by the symbol F1 in FIG. 5 indicate the flow direction of the multiphase fluid. The multiphase fluid that has flowed into the fluid flow path 400 flows into the inlet chambers 402 and 403 through the through-holes in the partition walls 401a and 401b. The multiphase fluid that has flowed into the inlet chambers 402 and 403 comes into contact with the hydrophilic membrane 52 and the hydrophobic membrane 53. At this time, the multiphase fluid flows from the fluid flow path 400 substantially perpendicular to the surfaces of the membranes, resulting in uniform contact with the multiphase fluid. In particular, when the hydrophilic film 52 has dry areas and wet areas, gas may escape from the dry areas, so it is preferable that the multiphase fluid contacts the surface uniformly.

[0027] When the multiphase fluid comes into contact with the hydrophilic membrane 52, the liquid in the multiphase fluid permeates the hydrophilic membrane 52 and flows into the liquid flow path 200. The hatched arrows indicated by the symbol L in Fig. 5 indicate the flow direction of the liquid permeating the hydrophilic membrane 52. The liquid that has flowed into the liquid flow path 200 is discharged to the outside of the device through a pair of liquid discharge pipes 21 that communicate with the liquid flow path 200.

[0028] Furthermore, when the multiphase fluid comes into contact with the hydrophobic membrane 53, the gas in the multiphase fluid permeates the hydrophobic membrane 53 and flows into the gas flow path 300. The hatched arrows indicated by the symbol G in Fig. 5 indicate the flow direction of the gas permeating the hydrophobic membrane 53. The gas that has flowed into the gas flow path 300 is discharged to the outside of the device through a pair of gas discharge pipes 31 that communicate with the gas flow path 300.

[0029] According to the embodiment described above, a gas-liquid separation function can be achieved by effectively separating liquid and gas in a multiphase fluid using only the hydrophilic membrane 52 and the hydrophobic membrane 53. Therefore, the device configuration is extremely simple, allowing for a smaller device size compared to conventional devices. In particular, sheet-like hydrophilic and hydrophobic membranes 52 and 53 are disposed on either side of a fluid flow path 400, with a liquid flow path 200 formed adjacent to the hydrophilic membrane 52 and a gas flow path 300 formed adjacent to the hydrophobic membrane 53. Therefore, the gas-liquid separation device 1 can be formed in a flat plate shape as shown in FIG. 1 , allowing it to be installed in small spaces such as gaps between devices or structures and making it easy to transport. Such a compact gas-liquid separation device 1 functions even in a microgravity environment and is therefore extremely useful in environments such as a space station where a gas-liquid separation device is essential but installation space is limited. Furthermore, the simple configuration allows for easy maintenance and low cost. Furthermore, the device is easy to use because it only requires connecting a pump or other device to each piping.

[0030] In this embodiment, the multiphase fluid to be subjected to gas-liquid separation has been described as a gas-liquid two-phase fluid, but this is not limited to this. Gas-liquid separation can also be performed on multiphase fluids with more phases, as long as the fluid contains gas.

[0031] (Second embodiment) The gas-liquid separator according to the first embodiment may be incorporated into a water electrolysis apparatus that generates hydrogen gas and oxygen gas by electrolyzing water. In this embodiment, a water electrolysis apparatus with an integrated gas-liquid separator will be described.

[0032] The configuration of a water electrolysis apparatus according to this embodiment will be described. FIG. 6 is a perspective view of the water electrolysis apparatus according to this embodiment. As shown in FIG. 6, the water electrolysis apparatus 1A according to this embodiment is a cell-stack type apparatus including multiple electrolysis cells 10A fastened to one another with bolts and nuts, and multiple heat radiation pipes (heat radiation portions) 12A inserted between the electrolysis cells 10A. The heat radiation pipes 12A are so-called heat pipes through which a heat exchange medium flows and exchanges heat with the outside. By inserting the heat radiation pipes 12A between the electrolysis cells 10A, they can promote heat radiation from the adjacent electrolysis cells. The number of inserted heat radiation pipes 12A may be appropriately determined depending on the scale of the apparatus. Note that, although three electrolysis cells 10A are connected in this embodiment, the number is not limited thereto, and two, four, or more electrolysis cells may be connected.

[0033] The water electrolysis apparatus 1A according to this embodiment electrolyzes water into oxygen gas and hydrogen gas using multiple electrolysis cells 10A, and the electrolysis cells 10A have the same configuration and operation. Therefore, hereinafter, the configuration and operation of one electrolysis cell 10A will be described.

[0034] First, the configuration of the electrolytic cell 10A will be described in detail below. For ease of explanation, a unit electrolytic cell having end plates 60, 70 provided on the front and back sides will be described as an example. FIGS. 7 to 10 are a perspective view, a front view, a right side view, and a left side view, respectively, of an electrolytic cell according to this embodiment. As shown in FIG. 7, the electrolytic cell 10A includes an end plate 60, an intermediate plate 61, an end plate 70, an intermediate plate 71, and current collector plates 81a, 81b.

[0035] The end plates 60, 70 are formed in the shape of square flat plates and constitute the front wall and rear wall of the electrolysis cell 10A. An intermediate plate 61, current collector plates 81a, 81b, and an intermediate plate 71 are disposed between the end plates 60, 70, and the end plates 60, 70 are fastened together with bolts and nuts to form the electrolysis cell 10A in an integrated, substantially rectangular parallelepiped shape. When stacking multiple electrolysis cells 10A as shown in FIG. 7 , multiple electrolysis cells each consisting of an intermediate plate 61, 71 may be interposed between a pair of end plates 60, 70.

[0036] The intermediate plates 61, 71 are formed to have the same shape and thickness as the end plates 60, 70. A water supply pipe 611, a drain pipe 612, and two hydrogen discharge pipes 613 are provided on the side of the intermediate plate 61. A water supply channel 614, a drain channel 615, and a hydrogen discharge channel 616 (see FIG. 12 ) are provided inside the intermediate plate 61, as will be described in detail later. The water supply pipe 611 is located on the lower left side in FIG. 8 and communicates with the water supply channel 614, and supplies water to the electrolysis cell 10A. The drain pipe 612 is located on the upper right side in FIG. 8 and communicates with the drain channel 615, and discharges water from the electrolysis cell 10A for circulating supply. The two hydrogen discharge pipes 613 are located on the lower right side and upper left side in FIG. 8, respectively, and communicate with the hydrogen discharge channel 616. The two hydrogen discharge pipes 613 discharge the hydrogen gas generated by electrolysis in the electrolysis cell 10A to the outside of the electrolysis cell 10A.

[0037] 9 and 10, oxygen exhaust pipes 711 are provided on the lower right side surface and the upper left side surface of the intermediate plate 71. The oxygen exhaust pipes 711 communicate with an oxygen exhaust channel 712 (see FIG. 12), which will be described in detail later, and exhaust oxygen gas generated by electrolysis in the electrolysis cell 10A to the outside of the electrolysis cell 10A.

[0038] The internal configuration of the electrolysis cell 10A will be described in detail below with reference to Fig. 11. Fig. 11 is an exploded side view showing the configuration of an electrolysis cell according to this embodiment. In Fig. 11, the electrolysis cell 10A is shown exploded in the front-to-rear direction, and for the sake of explanation, the O-rings 62, 72 and the gaskets 65, 82 are shown partially in cross section.

[0039] 11, the electrolysis cell 10A includes, in order from the left side in Fig. 11, i.e., the front side of the cell, an end plate 60, an intermediate plate 61, an O-ring 62, a separator 63, carbon paper 64, a gasket 65, a hydrophobic membrane 53, a gasket 65, the carbon paper 64, a current collector 81a, a gasket 82, an MEA (Membrane and Electrode Assembly) 80, a current collector 81b, an O-ring 72, an intermediate plate 71, and an end plate 70. The left side of the MEA 80 in Fig. 11 is the hydrogen side where water is supplied and hydrogen gas is produced, and the right side of the MEA 80 in Fig. 11 is the oxygen side where oxygen gas is produced.

[0040] The MEA 80 is a roughly rectangular plate-shaped member formed by sandwiching a solid polymer electrolyte membrane (hereinafter referred to as the electrolyte membrane) between gas diffusion electrode layers from the front and rear, with one side on the hydrogen side and the other on the oxygen side, and then joining these together. + It is preferable to use a porous electrolyte membrane having a high proton conductivity, such as inorganic ceramics containing titanium hydroxide nanoparticles or proton-conductive Nafion (registered trademark).

[0041] The gas diffusion electrode layer is porous, allowing hydrogen gas and oxygen gas to pass through. Examples of materials that can be used for such diffusion layers include Teflon (registered trademark)-modified porous carbon. A catalyst layer made of platinum, gold, or the like is provided between the gas diffusion electrode layer and the electrolyte membrane. In this embodiment, the catalyst layer is formed on the electrolyte membrane. The electrolysis cell 10A according to this embodiment is a cathode feed type in which water is supplied only to the cathode side to perform electrolysis. The water supplied to the cathode side permeates the electrolyte membrane and also penetrates to the anode side. The cathode-side gas diffusion electrode layer and current collector plate 81a form a cathode-side electrode unit, and the anode-side gas diffusion electrode layer and current collector plate 81b form an anode-side electrode unit.

[0042] The MEA 80 is sandwiched or fixed between current collector plates 81a and 81b via frame-shaped gaskets 82 located on both sides and connecting to its edges. The current collector plates 81a and 81b are plate-shaped members that are electrically connected to an external power supply to apply a voltage to the MEA 80, and in FIG. 8, connection pieces for connecting to the external power supply protrude upward. In this embodiment, the current collector plates 81a and 81b are configured integrally with the separator. Multiple grooves are formed so as to penetrate the separator of the current collector plate 81a, and when the electrolysis cell 10A is assembled, these multiple grooves form water flow channels 811 (see FIG. 12) into which water flows. The water flow channel 811 functions as a liquid supply chamber into which a cathode electrode portion is located and into which liquid is supplied, and water is supplied to the MEA 80. The water flow channel 811 is preferably formed so that water supplied to the MEA 80 is supplied to the entire membrane surface of the electrolyte membrane. The water flow path 811 communicates with the water supply pipe 611 via a water supply path 614 formed in the intermediate plate 61 , and communicates with the drain pipe 612 via a drain path 615 .

[0043] Meanwhile, multiple grooves are also formed in the separator of current collector plate 81b, and these multiple grooves form oxygen flow paths 713 (see FIG. 12 ) into which oxygen gas generated by electrolysis flows when electrolysis cell 10A is assembled. Oxygen flow path 713 is connected to oxygen exhaust path 712 formed in adjacent intermediate plate 71, and communicates with oxygen exhaust pipe 711 via oxygen exhaust path 712. Note that O-ring 72 is an elastic member, and airtightly connects the separator of current collector plate 81b and intermediate plate 71 via O-ring 72.

[0044] A rectangular hydrophobic membrane 53 is disposed on the front side of the current collector plate 81a. The hydrophobic membrane 53 is disposed opposite the MEA 80 so as to be spaced apart from each other, and forms a partition wall for part of the liquid supply chamber formed by the water flow path 811. This hydrophobic membrane 53 is the same as that described in the first embodiment, so a description of its function will be omitted here. The hydrophobic membrane 53 is fixed to the current collector plate 81a and the separator via frame-shaped gaskets 65 located on both sides and connecting to its edges. Gas-permeable carbon paper 64 is disposed between the hydrophobic membrane 53 and the current collector plate 81a to allow diffusion of gas and water. The carbon paper 64 allows the hydrophobic membrane 53 to come into contact with water and hydrogen gas that forms bubbles in the water.

[0045] It is preferable that the distance between the hydrophobic membrane 53 and the electrolyte membrane of the MEA 80, more specifically, the distance from the cathode-side catalyst layer, be the distance described in the first embodiment. This allows hydrogen gas bubbles generated and attached to the catalyst layer surface to come into contact with the hydrophobic membrane 53, allowing them to immediately permeate the hydrophobic membrane 53. As in the first embodiment, this distance is based on the size of the generated gas bubbles, and it is preferable that the bubbles come into contact with the hydrophobic membrane 53 before detaching from the catalyst layer. This distance is preferably about 1 mm, for example, which allows water and bubbles to each come into contact with the hydrophobic membrane 53.

[0046] Separator 63, located in front of hydrophobic membrane 53, is provided with a plurality of grooves that form hydrogen flow paths 631 (see FIG. 12 ), into which hydrogen gas that has permeated hydrophobic membrane 53 flows. Hydrogen flow paths 631 of separator 63 are connected via O-rings 62 to hydrogen discharge paths 616 formed in adjacent intermediate plate 61, and communicate with hydrogen discharge pipe 613 via these paths. Separator 63 also has grooves formed therein that are separate from the grooves that form hydrogen flow paths 631, and these grooves serve as water flow paths that connect water flow paths 811 in the separator of current collector plate 81a to water supply paths 614 formed in intermediate plate 61. O-rings 62 are elastic members that connect separator 63 and intermediate plate 61 airtightly.

[0047] (device operation) The operation of the electrolysis cell 10A according to this embodiment will be described below. FIG. 12 is a schematic diagram illustrating the internal configuration and fluid flow of the electrolysis cell according to this embodiment. The dashed-two-dot lines in the figure illustrate the joints of each flow path. Symbol P1 indicates a pump, symbol H1 indicates the flow direction of hydrogen gas, symbol H2 indicates hydrogen gas bubbles, and symbol O1 indicates the flow direction of oxygen gas. The pump P1 is connected to a water supply pipe 611 and a drain pipe 612, and supplies water to the water supply pipe 611 and obtains water from the drain pipe 612, circulating the water to the electrolysis cell 10A. Note that the electrolysis cell 10A is constantly supplied with water used for electrolysis from an external water supply device.

[0048] 12, water supplied through a water supply pipe 611 flows into a water flow path 811 via a water supply channel 614, and the water that has flowed into the water flow path 811 is supplied to the entire membrane surface of the electrolyte membrane 800 in the MEA 80. Here, water is electrolyzed by applying a voltage to current collectors 81a and 81b, which are connected to an external power source. Hydrogen gas produced by the electrolysis at the interface between the cathode-side gas diffusion electrode layer 801 and the electrolyte membrane 800 of the MEA 80, i.e., at the catalyst layer, comes into contact with and permeates the hydrophobic membrane 53 in the water flow path 811, and then flows into the hydrogen flow path 631. Specifically, the produced hydrogen gas diffuses and permeates the interior of the gas diffusion electrode layer, passes through the separator and carbon paper 64 of the current collector 81a, and comes into contact with the hydrophobic membrane 53. The hydrogen gas in the hydrogen flow channel 631 that has permeated the hydrophobic membrane 53 is discharged from the hydrogen discharge pipe 613 via the hydrogen discharge channel 616 to the outside of the electrolysis cell 10A and collected in a collection container or the like.

[0049] Meanwhile, water in the water flow path 811 that was not used for electrolysis is discharged via the drainage channel 615 and the drainage pipe 612 to the pump P1 and is then supplied again into the electrolysis cell 10A. Hydrogen gas produced by electrolysis at the interface between the anode-side gas diffusion electrode layer 802 of the MEA 80 and the electrolyte membrane 800 flows into the oxygen flow path 713, and is discharged via the oxygen discharge channel 712 and the oxygen discharge pipe 711 to the outside of the electrolysis cell 10A and collected in a collection container or the like.

[0050] According to the water electrolysis apparatus 1A of this embodiment described above, the hydrophobic membrane 53 is disposed in the water flow path 811, which serves as the cathode chamber on the cathode side. Therefore, water circulates through the water flow path 811 between the hydrophobic membrane 53 and the MEA 80, enabling reliable gas-liquid separation to be performed simultaneously with electrolysis. In particular, hydrogen gas can be recovered in a dry, favorable state. Therefore, the electrolysis cell can have the function of a gas-liquid separator, eliminating the need for a separate gas-liquid separator. This allows for a significantly smaller apparatus compared to a water electrolysis apparatus that is individually connected to a gas-liquid separator. Furthermore, the apparatus can be installed in small spaces, such as gaps between devices or structures, and is easily transported. Such a compact water electrolysis apparatus 1A functions even in a microgravity environment and is therefore extremely useful in environments such as a space station, where a water electrolysis apparatus is essential but installation space is limited.

[0051] Furthermore, when supplying water to the cathode side, a gas phase exists in the water tank on Earth, absorbing the pressure. However, when performing water electrolysis in a microgravity environment, an incompressible fluid such as water must be circulated in a sealed container without a gas phase. When water electrolysis is performed in a sealed space, gas generated in the electrolytic cell increases the pressure inside the electrolytic cell, disrupting the pressure balance between the oxygen and hydrogen sides. If left unchecked, this can result in one-sided pressure being applied to the electrolyte membrane, potentially damaging it. Therefore, a volume buffering device such as an accumulator is required in the past. However, in this embodiment, hydrogen gas generated in the MEA 80 immediately permeates and is discharged through the hydrophobic membrane 53, providing a volume buffer, preventing pressure buildup on only one side due to gas generation. This eliminates the need for a volume buffering device, enabling cost reduction and miniaturization. Furthermore, because water is supplied only to the cathode side, the use of a single pump P1 also contributes to cost reduction and miniaturization.

[0052] In addition, conventional methods involve permeating water from the periphery to the center of the MEA electrolyte membrane. However, this method separates the water path and the reaction path, reducing the effective membrane area of ​​the electrode. Furthermore, because the interface is maintained by surface tension, an imbalance between the pressure on the liquid side and the pressure on the gas side can lead to leakage of the liquid into the gas side or penetration of the gas into the liquid. However, in this embodiment, the water supplied to the MEA 80 is supplied to the entire membrane surface of the electrolyte membrane 800, so the distance the water permeates is limited only by the membrane thickness. This ensures a smooth and flexible water supply path, making it easy to circulate water.

[0053] The electrolysis cell 10A can also have an air regeneration function by connecting it to a Sabatier reactor, which produces methane (CH4) and water (H2O) from carbon dioxide (CO2) and oxygen (O2). Air regeneration is a process in which O2 is extracted again from the CO2 emitted by astronauts. Specifically, CO2 emitted into a sealed space by living organisms is separated and concentrated, and then led to the Sabatier reactor. In the Sabatier reactor, the Sabatier reaction (CO2 + 4H2 → CH4 + 2H2O) takes place, producing CH4 and H2O.

[0054] The electrolysis cell 10A generates hydrogen gas and oxygen gas by receiving water produced by the Sabatier reaction from the Sabatier reactor. Living organisms breathe the oxygen gas, and the hydrogen gas is sent back to the Sabatier reactor. This cycle allows oxygen to be consumed and carbon dioxide emitted by living organisms to be regenerated, thereby achieving air regeneration.

[0055] Furthermore, in the water electrolysis apparatus 1A, stacking multiple electrolysis cells 10A can increase the amounts of hydrogen gas and oxygen gas produced compared to using only one electrolysis cell 10A. In this case, for example, it is preferable to connect the water circulation supply path (the water supply pipe 611 and the drain pipe 612) to the pump P1 to a manifold so that the water circulation supply path and the pump P1 are shared by the multiple electrolysis cells 10A, and the same applies to the hydrogen gas and oxygen gas discharge paths (the hydrogen discharge pipe 613 and the oxygen discharge pipe 711).

[0056] (First Modification) Fig. 13 is a schematic diagram illustrating the internal configuration and fluid flow of the electrolysis cell according to the first modification. In Fig. 13, reference symbol P2 denotes a pump, which is similar to pump P1. Reference symbol O2 denotes oxygen gas bubbles.

[0057] 13 differs from the electrolysis cell 10A according to the second embodiment in that a hydrophobic membrane 53' is also arranged on the anode side, a water flow path 812 is formed between the hydrophobic membrane 53' and the MEA 80 as a second liquid supply chamber to which an anode-side electrode part is arranged and to which water is supplied, and water is circulated and supplied to the water flow path 812 by a pump P2. The hydrophobic membrane 53' is the same as the hydrophobic membrane 53, but differs in that it forms a partition wall of part of the water flow path 812 and allows only oxygen gas generated by electrolysis on the anode side of the electrolyte membrane 800 to pass through.

[0058] Specifically, the electrolysis cell 10B can be constructed by arranging an intermediate plate 61, an O-ring 62, a separator 63, a carbon paper 64, a gasket 65, a hydrophobic membrane 53, a gasket 65, a carbon paper 64, and a current collector 81a in a mirror image arrangement relative to the MEA 80, instead of the current collector 81b, the O-ring 72, and the intermediate plate 71 shown in Fig. 11 . This allows oxygen gas, rather than hydrogen gas, to flow into the hydrogen gas flow path of each of the mirror-image arranged components. That is, each of the mirror-image arranged components circulates water to the anode side and discharges oxygen gas that has permeated the hydrophobic membrane 53.

[0059] By providing the hydrophobic membrane 53' on the anode side in this way, the same effect as on the cathode side can be achieved on the anode side, allowing for the recovery of high-quality dried oxygen gas. In addition, since water can be supplied from both sides of the MEA 80, the heat dissipation function inside the cell generated by electrolysis can be further improved.

[0060] (Second Modification) Fig. 14 is a schematic diagram illustrating the internal configuration and fluid flow of an electrolysis cell according to a second modification. The electrolysis cell 10C shown in Fig. 14 differs from the electrolysis cell 1A according to the second embodiment in that it does not include a drainage channel 615. Therefore, the electrolysis cell 10C does not have a water circulation function, and is a dead-end type in which all water flowing into the water flow channel 811 is used for water electrolysis.

[0061] The amount of water required to produce enough oxygen for one person through water electrolysis is small, approximately 0.5 g per minute. Conventional water electrolysis requires the circulation of several liters of water to remove bubbles from the electrodes and to remove heat, and requires a pump for circulating the water, a gas-liquid separator, and power for these. However, with the electrolytic cell 10C of this modification, by supplying only the small amount of water necessary for water electrolysis (e.g., 0.5 g per minute), all of the supplied water can be electrolyzed. This eliminates the need for a gas-liquid separator and the pump P1 for circulating the water compared to conventional systems, significantly simplifying the oxygen gas production system and ultimately enabling a smaller, lighter, and more energy-efficient system, as well as improved system reliability.

[0062] The electrolytic cell 10C can be integrated with the Sabatier reactor described in the first embodiment. Conventional electrolytic cells lower their cell temperature by circulating water, which also lowers the temperature of the Sabatier reactor. On the other hand, the electrolytic cell 10C does not require water circulation, allowing the reaction to continue without lowering the temperature of the integrated Sabatier reactor. Furthermore, stacking the electrolytic cell 10C and the Sabatier reactor allows for a very compact device. Furthermore, the heat generated in the Sabatier reactor can also be used to heat the water electrolysis cell, making it possible to lower the electrolysis voltage.

[0063] Furthermore, when water circulation is not performed as in this modified example, heat may accumulate inside the cell. In this case, a heat radiation pipe 12A as shown in Fig. 7 may be provided on one of the intermediate plates 61, 71 of the electrolysis cell 10C, or between the electrolysis cells 10C when the electrolysis cells 10C are stacked.

[0064] Although an embodiment of the invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its modifications are included within the scope and spirit of the invention, and are also included in the invention described in the claims and their equivalents. [Explanation of symbols]

[0065] 1 Gas-liquid separator 1A water electrolysis device 10A, 10B, 10C Electrolytic Cell 12A heat radiation tube (heat radiation part) 400 Fluid flow path (supply path) 52 Hydrophilic membrane (hydrophilic partition) 53, 53' Hydrophobic membrane (hydrophobic partition) 616 Hydrogen exhaust channel (exhaust channel) 712 Oxygen exhaust channel (second exhaust channel) 81a, 81b Current collector plates (cathode electrode portion, anode electrode portion) 800 Solid polymer electrolyte membrane 801 Cathode side gas diffusion electrode layer (cathode side electrode part) 802 Anode side gas diffusion electrode layer (anode side electrode part) 811,812 Water flow path (liquid supply chamber, 2nd liquid supply chamber)

Claims

1. A gas-liquid separation device that separates a liquid and a gas from a gas-liquid multiphase fluid, a hydrophobic partition wall portion for the multiphase fluid formed by a hydrophobic membrane that allows only the gas in the multiphase fluid to pass through; a supply channel for supplying the multiphase fluid to the hydrophobic partition wall; a hydrophilic partition wall portion for the multiphase fluid, which is formed by a hydrophilic membrane that allows only the liquid in the multiphase fluid supplied by the supply channel to pass therethrough; Equipped with the hydrophobic film and the hydrophilic film are formed in a sheet shape and are provided so as to face each other and be spaced apart from each other; A pair of partition walls, each having a plurality of through-holes and spaced apart from each other, are disposed between the hydrophobic membrane and the hydrophilic membrane, and the supply channel is formed between the pair of partition walls. A gas-liquid separation device characterized by:

2. A gas-liquid separation method for separating a liquid and a gas from a gas-liquid multiphase fluid, comprising: The multiphase fluid flows between a pair of partition walls spaced apart from each other, the multiphase fluid comes into contact with a hydrophobic membrane that allows only the gas in the multiphase fluid to permeate through a through-hole formed in one of the pair of partition walls, and allows only the gas to permeate from the multiphase fluid through the hydrophobic membrane; Conducting the permeated gas; the multiphase fluid comes into contact with a hydrophilic membrane that allows only the liquid in the multiphase fluid to pass through a through-hole formed in the other of the pair of partition walls, and only the liquid from the multiphase fluid passes through the hydrophilic membrane; Conducting the permeated liquid A gas-liquid separation method characterized by:

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