Membrane humidifier for fuel cell

Abstract

Disclosed is a membrane humidifier for a fuel cell, which can prevent degradation of performance of the fuel cell caused by harmful gas during humidification without a separate gas filtration device. The humidifier for a fuel cell according to the present invention comprises: a housing unit comprising a first fluid inlet through which a first fluid flows in, a first fluid outlet through which the first fluid flows out, a second fluid inlet through which a second fluid flows in, and a second fluid outlet through which the second fluid flows out, the humidity of the first fluid flowing in through the first fluid inlet is different from that of the second fluid flowing in through the second fluid inlet; at least one first cartridge installed inside the housing unit and accommodating a plurality of hollow fiber membranes therein; and a gas filter provided inside the first cartridge or between the inner peripheral surface of the housing unit and the first cartridge so as to be able to collect harmful gas contained in the first fluid and / or the second fluid, the gas filter having a shape different from that of the hollow fiber membrane.

Description

[0001] This case is a divisional application, and its parent case is an application with an application date of August 6, 2021, application number 201980086012.1, and invention name “Membrane humidifier for fuel cell”. Technical Field

[0002] The present invention relates to a membrane humidifier for a fuel cell, and more particularly to a membrane humidifier capable of removing nitrogen oxides (NO x ), sulfur oxides (SO x ) and ammonia (NH 3) and other gases without the need for a separate gas filtering device, thereby preventing the performance of the fuel cell from being deteriorated. Background Art

[0003] A fuel cell is a power generation cell that combines hydrogen and oxygen to generate electricity. The advantages of this fuel cell are that, unlike ordinary chemical batteries such as dry cells, storage batteries, etc., it can generate electricity continuously as long as hydrogen and oxygen are supplied, and it also has the advantage of no heat loss, so the efficiency of the fuel cell is about twice that of the internal combustion engine.

[0004] In addition, the fuel cell directly converts chemical energy generated by the combination of hydrogen and oxygen into electrical energy, thereby the emission of pollutants is small. Therefore, the fuel cell has the advantage that the fuel cell is environmentally friendly and can reduce the concern about resource depletion caused by the increase in energy consumption.

[0005] Based on the type of electrolyte used, fuel cells can generally be classified as polymer electrolyte membrane fuel cells (PEMFC), phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), solid oxide fuel cells (SOFC) or alkaline fuel cells (AFC).

[0006] These fuel cells operate on basically the same principle, but differ from each other in the type of fuel used, operating temperature, catalyst, and electrolyte. Among these fuel cells, polymer electrolyte membrane fuel cells (PEMFCs) are known to be the most advantageous for transportation systems and small stationary power generation equipment because the polymer electrolyte membrane fuel cell operates at a lower temperature than other fuel cells and the output density of the polymer electrolyte membrane fuel cell is high, thereby miniaturizing the polymer electrolyte membrane fuel cell.

[0007] One of the most important factors for improving the performance of polymer electrolyte membrane fuel cells (PEMFCs) is to supply a specified amount or more of water to the polymer electrolyte membrane or the proton exchange membrane (PEM) of the membrane electrode assembly (MEA) to maintain the moisture content. The reason for this is that when the polymer electrolyte membrane or the proton exchange membrane is dry, the power generation efficiency is drastically reduced.

[0008] As methods for humidifying the polymer electrolyte membrane or the proton exchange membrane, 1) a bubbler humidification method of filling a pressure-resistant container with water and passing the target gas through a diffuser to supply moisture, 2) a direct injection method of calculating the amount of moisture to be supplied required for the fuel cell reaction and supplying moisture directly to the gas flow pipe through an electromagnetic valve, and 3) a membrane humidification method of supplying moisture to a gas fluidized bed using a polymer separation membrane are used.

[0009] Among these methods, the membrane humidification method of humidifying the polymer electrolyte membrane or the proton exchange membrane by providing water vapor to the gas supplied to the polymer electrolyte membrane or the proton exchange membrane through a membrane configured to selectively permeate only the water vapor contained in the exhaust gas has the advantage that the weight and size of the humidifier can be reduced.

[0010] In the case of forming an assembly, a hollow fiber membrane having a large permeation area per unit volume is suitable for a selective permeation membrane used in a membrane humidification method. That is, in the case of manufacturing a membrane humidifier using a hollow fiber membrane, the hollow fiber membrane having a large contact surface area can be highly integrated, thereby making it possible to sufficiently humidify a fuel cell even in a small capacity, to use inexpensive materials, and to collect moisture and heat contained in exhaust gas discharged from a fuel cell at a high temperature, and to reuse the collected moisture and heat by the humidifier.

[0011] In a conventional membrane humidifier for a fuel cell, a hollow fiber membrane is accommodated in a housing unit, and the hollow fiber membrane is fixed to the inner wall of the housing unit by a potting portion. A certain number of hollow fiber membranes are accommodated in the housing unit according to the desired output of the cell stack, and are fixed to the housing unit by a potting portion. High temperature air from a blower and high temperature and high humidity air from the cell stack are introduced into the membrane humidifier for a fuel cell.

[0012] In a fuel cell system, when high-temperature air generated by a compressor or a blower is introduced into the cell stack through a humidifier, nitrogen oxides (NO x ), sulfur oxides (SO x ), ammonia (NH3), etc. are introduced into the fuel cell stack and may deteriorate the performance of the fuel cell stack. For this reason, a separate gas filtering device configured to remove these substances is usually installed at the front end or rear end of the air compressor.

[0013] [Related patent documents]

[0014] 1. Korean Patent Application Publication No. 10-2009-0013304

[0015] 2. Korean Patent Application Publication No. 10-2009-0057773

[0016] 3. Korean Patent Application Publication No. 10-2009-0128005

[0017] 4. Korean Patent Application Publication No. 10-2000-0108092

[0018] 5. Korean Patent Application Publication No. 10-2000-0131631

[0019] 6. Korean Patent Application Publication No. 10-2001-0001022

[0020] 7. Korean Patent Application Publication No. 10-2001-0006122

[0021] 8. Korean Patent Application Publication No. 10-2001-0006128

[0022] 9. Korean Patent Application Publication No. 10-2001-0021217

[0023] 10. Korean Patent Application Publication No. 10-2001-0026696

[0024] 11. Korean Patent Application Publication No. 10-2001-0063366 Summary of the invention

[0025] Technical issues

[0026] The object of the present invention is to provide a membrane humidifier for a fuel cell, which is capable of removing nitrogen oxides (NO x ), sulfur oxides (SO x ) and ammonia (NH 3) and other gases without the need for a separate gas filtering device, thereby preventing the performance of the fuel cell from being deteriorated.

[0027] Technical Solution

[0028] In order to achieve the above-mentioned purpose, a membrane humidifier for a fuel cell according to the present invention comprises: a housing unit, the housing unit comprising a first fluid inlet for introducing a first fluid, a first fluid outlet for discharging the first fluid, a second fluid inlet for introducing a second fluid, and a second fluid outlet for discharging the second fluid, the humidity of the first fluid introduced via the first fluid inlet being different from the humidity of the second fluid introduced via the second fluid inlet; at least one first box installed in the housing unit, the first box having a plurality of hollow fiber membranes; and a gas filter arranged in the first box or between the inner circumferential surface of the housing unit and the first box, the gas filter being configured to capture harmful gases contained in at least one of the first fluid and the second fluid, the gas filter having a shape different from that of the hollow fiber membranes, and the harmful gases including nitrogen oxides (NO x ), sulfur oxides (SO x ), ammonia (NH3) or a mixture of two or more thereof.

[0029] The membrane humidifier may further include at least one second cartridge installed in the housing unit, wherein the second cartridge may be filled with the gas filter only.

[0030] A gas filter may be arranged in the first cassette together with the hollow fiber membranes.

[0031] The gas filter may include a non-woven fabric and a gas capturing material coated on the non-woven fabric.

[0032] The gas filter may include yarn and a gas capture material coated on the yarn.

[0033] The membrane humidifier may include a plurality of first cassettes, and the gas filter may be installed in the housing unit in such a manner as to surround the first cassettes together.

[0034] The gas filter may be installed over the inner peripheral surface or the outer peripheral surface of the first cassette in such a manner as to surround the plurality of hollow fiber membranes.

[0035] The gas filter may include a non-woven fabric and a gas capturing material coated on the non-woven fabric.

[0036] The gas capture material may be any one selected from the group consisting of biochar, charcoal, activated carbon, acidic polymer, zeolite, platinum, a mixture of copper sulfate and titanium sulfate, niobium (Nb), sodium bicarbonate, and a mixture of two or more thereof.

[0037] The acidic polymer can be any one selected from the group consisting of perfluorosulfonic acid (PFSA), sulfonated polyethersulfone (S-PES), sulfonated polyarylethersulfone (S-PAES), sulfonated polystyrene (S-PS), sulfonated polyetherketone (S-PEK), sulfonated polyetheretherketone (S-PEEK) and a mixture of two or more thereof.

[0038] The gas filter may be installed in the housing unit in such a manner that the first fluid introduced via the first fluid inlet passes through the gas filter before being introduced into the inner lumens of the hollow fiber membranes.

[0039] The housing unit may include an intermediate shell in which a first box is installed and a pair of cover shells coupled to opposite sides of the intermediate shell, a second fluid inlet and a second fluid outlet are formed in the intermediate shell, a first fluid inlet and a first fluid outlet are formed in the cover shell, and a gas filter can be detachably installed between the cover shell having the first fluid inlet and the intermediate shell.

[0040] The gas filter may include a filter part and a frame part coupled to the filter part in such a manner as to surround the filter part, and the filter part may include a non-woven fabric and a gas capturing material coated on the non-woven fabric.

[0041] Beneficial Effects

[0042] The membrane humidifier for a fuel cell according to the present invention can remove nitrogen oxides (NO x ), sulfur oxides (SO x ) and ammonia (NH3) and other gases without the need for a separate gas filtering device, thereby preventing the performance of the fuel cell from deteriorating. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is an exploded perspective view of a membrane humidifier for a fuel cell according to an embodiment of the present invention.

[0044] Figure 2 is a cross-sectional view of a membrane humidifier according to a first embodiment of the present invention.

[0045] Figure 3 is a cross-sectional view of an embodiment related to the type of gas filter.

[0046] Figure 4 is a cross-sectional view of a membrane humidifier according to a second embodiment of the present invention.

[0047] Figure 5 is a cross-sectional view of a membrane humidifier according to a third embodiment of the present invention.

[0048] Figure 6 is a schematic diagram of the structure of a gas filter installed in an intermediate housing of a membrane humidifier.

[0049] Figure 7 is a cross-sectional view of a membrane humidifier according to a fourth embodiment of the present invention.

[0050] Figure 8It is a schematic diagram showing a structure in which a gas filter is installed inside or outside a case of a membrane humidifier.

[0051] Fig. 9 is a cross-sectional view of a membrane humidifier according to a fifth embodiment of the present invention.

[0052] Fig.10 1 is a schematic diagram showing the structure of a gas filter installed between an intermediate housing and a cover housing of a membrane humidifier. DETAILED DESCRIPTION

[0053] Figure 1 is an exploded perspective view of a membrane humidifier for a fuel cell according to an embodiment of the present invention, Figure 2 is a cross-sectional view showing a membrane humidifier according to a first embodiment of the present invention, Figure 3 is a cross-sectional view showing an embodiment related to the type of gas filter.

[0054] The membrane humidifier for a fuel cell according to an embodiment of the present invention includes a housing unit and a plurality of cartridges 150 installed in the housing unit. At least one of the cartridges 150 is a first cartridge having a plurality of hollow fiber membranes 160 therein. The intermediate housing 110 and the cover housing 120 may be coupled to each other to form the housing unit, or the housing unit may be formed as one integral body.

[0055] The intermediate housing 110 is coupled to a pair of cover housings 120 at opposite sides thereof to define the appearance of the membrane humidifier. Each of the intermediate housing 110 and the cover housing 120 may be made of hard plastic (e.g., polycarbonate) or metal. The cross-sectional shape of each of the intermediate housing 110 and the cover housing 120 may be as follows: Figure 1 The polygon shown, or its cross-sectional shape may be a circle. The polygon may be a rectangle, a square, a trapezoid, a parallelogram, a pentagon, a hexagon, etc., and the corners of the polygon may be rounded. In addition, the circle may be an ellipse.

[0056] The intermediate housing 110 is provided with a second fluid inlet 112 through which the second fluid is introduced and a second fluid outlet 113 through which the second fluid is discharged.

[0057] One of the cover housings 120 coupled to opposite ends of the intermediate housing 110 has a first fluid inlet 121, and the other cover housing 120 has a first fluid outlet 122. The first fluid introduced into the housing unit via the first fluid inlet 121 passes through the inner pipe of each hollow fiber membrane 160 accommodated in the first cassette 150, and then is discharged via the first fluid outlet 122. The first fluid inlet 121 and the first fluid outlet 122 may be switched with each other so that the first fluid flows in opposite directions.

[0058] Each hollow fiber membrane 160 may be a hollow fiber membrane made of, for example, Nafion, polyetherimide, polyimide (PI), polyphenylsulfone, polysulfone (PS), or polyethersulfone (PES).

[0059] A grid portion 152 configured to allow a second fluid introduced into the membrane humidifier via the second fluid inlet 112 to be introduced into the first box 150 may be formed on one side of the first box 150, and a grid portion 152 configured to allow a second fluid that has undergone moisture exchange in the hollow fiber membrane box 150 to be discharged from the first box 150 may be formed on the other side of the first box 150.

[0060] The first box 150 is provided with potting parts at opposite ends thereof, which are configured to join the hollow fiber membranes 160 and fill the gaps between the hollow fiber membranes 160. In this way, the opposite ends of the first box 150 are blocked by the potting parts, respectively, thereby defining therein a flow channel configured to allow the second fluid to flow therethrough. Each potting part is made of a known material, and a detailed description thereof will be omitted here.

[0061] The intermediate housing 110 has a second fluid inlet 112 and a second fluid outlet 113 .

[0062] The first fluid may be a low-humidity fluid (e.g., external air supplied by a blower), and the second fluid may be a high-humidity fluid (e.g., high-humidity exhaust gas exhausted from a fuel cell stack). Alternatively, the second fluid may be low-humidity external air, and the first fluid may be high-humidity exhaust gas.

[0063] A plurality of insertion ports 140 configured to allow a plurality of cartridges 150 to be installed therein may be formed in the intermediate housing 110 , and each cartridge 150 may be inserted into a corresponding one of the insertion ports 140 .

[0064] In the present invention, a gas filter configured to capture harmful gases contained in at least one of the first fluid and the second fluid and having a shape different from that of the hollow fiber membrane 160 is provided in the first box 150 or between the inner circumferential surface of the housing unit and the first box 150. Harmful gases include nitrogen oxides (NO x ), sulfur oxides (SO x ), ammonia (NH3), or a mixture of two or more thereof. Since the gas filter is disposed in the housing unit, the membrane humidifier 100 for a fuel cell according to an embodiment of the present invention can capture harmful gases during humidification without a separate gas filter device, thereby preventing the performance of the fuel cell from being deteriorated.

[0065] In a fuel cell system, high-temperature air supplied from a compressor or a blower is introduced into the cell stack via a humidifier. If the air contains harmful substances, such as (i) nitrogen oxides (NOx) such as nitric oxide (NO), nitrogen dioxide (NO2), nitrous oxide (N2O), nitrogen trioxide (N2O3), nitrogen tetroxide (N2O4), nitrogen pentoxide (N2O5), etc.; (ii) sulfur oxides (SO2), sulfur trioxide (SO3), sulfurous acid (H2SO3), sulfuric acid (H2SO4), etc., the air will be humidified. x ); (iii) ammonia (NH3) or the like is introduced into the fuel cell stack, the performance of the fuel cell stack may be deteriorated. In the present invention, the gas filter provided in the membrane humidifier 100 captures harmful substances when the air is humidified, thereby preventing the performance of the fuel cell from being deteriorated.

[0066] In the first embodiment of the present invention, Figure 2 As shown, the plurality of cassettes 150 may include at least one first cassette having a plurality of hollow fiber membranes 160 therein and at least one second cassette filled with only a gas filter.

[0067] exist Figure 2 , an embodiment is shown in which the hollow fiber membranes 160 are disposed in two first boxes among three boxes 150 installed in the intermediate housing 110, and a plurality of filter members 210 are disposed in one second box. However, if four or more boxes 150 are installed in the intermediate housing 110, the filter members 210 may be accommodated in two or more boxes 150.

[0068] In the membrane humidifier 100 according to the first embodiment, low humidity air is introduced into the housing unit via the second fluid inlet 112. A portion of the low humidity air passes through the second box 140 having the filter member 210 therein to capture and filter harmful gases. When passing through the first box 150 having the hollow fiber membrane 160 therein, another portion of the air exchanges moisture with the first fluid (i.e., high humidity exhaust gas) and is humidified. The filtered air and humidified air generated by passing through each box 150 are gathered together and discharged through the second fluid outlet 113 to be supplied to the fuel cell stack.

[0069] Figure 3 Two types of gas filters are shown. Figure 3 The gas filter shown in (a) includes a non-woven fabric 213 and a gas capture material 211 coated on the non-woven fabric 213. The non-woven fabric 213 is formed not by weaving fibers but by combining them into a cloth form through mechanical, chemical or thermal treatment. Non-woven fabric is also called bonded fabric. The non-woven fabric 213 has a sheet or film form and is used as a substrate for fixing the gas capture material 211.

[0070] The gas filter may be manufactured by dissolving or dispersing the gas capture material 211 in a liquid phase, applying it to the non-woven fabric 213, and drying it, or by spraying a powder type gas capture material 211 on the non-woven fabric 213. Specifically, more preferably, the gas capture material 211 is coated on the non-woven fabric 213, and then the gas capture material 211 is covered with another non-woven fabric 213. The reason for this is that this structure can prevent the loss of the gas capture material 211.

[0071] The filter member 210 formed by coating the gas capture material 211 on the non-woven fabric 213 may be cut into a length equal to or less than the length of the hollow fiber membrane 160 and a specified width, and may be disposed and potted so as to be fixed in the first and / or second box 150 .

[0072] Figure 3 The gas filter shown in (b) includes yarn 214 and gas capture material 212 coated on the yarn 214. The yarn 214 can be a monofilament or a multifilament formed of at least one selected from the group consisting of polyvinylidene fluoride, polycarbonate, polystyrene, polyester fiber, polyolefin, polyamide, polymethyl methacrylate, polyvinyl chloride and glass fiber, or a thread including both monofilament and multifilament.

[0073] The gas capture material 212 may be Figure 3 The gas-trapping material 211 of (a) is the same type. It can be manufactured by applying a liquid type gas-trapping material 212 to the outer peripheral surface of a yarn 214 having a circular cross section and then drying it. Figure 3 (b) Gas filter.

[0074] The gas capture materials 211 and 212 may be any one selected from the group consisting of biochar, charcoal, activated carbon, acidic polymer, zeolite, platinum, a mixture of copper sulfate and titanium sulfate, niobium (Nb), sodium bicarbonate, and a mixture of two or more thereof.

[0075] The acidic polymer can be any one selected from the group consisting of poly(perfluorosulfonic acid) (PFSA), sulfonated polyethersulfone (S-PES), sulfonated polyarylethersulfone (S-PAES), sulfonated polystyrene (S-PS), sulfonated polyetherketone (S-PEK), sulfonated polyetheretherketone (S-PEEK) and a mixture of two or more thereof.

[0076] Figure 4 is a cross-sectional view of a membrane humidifier according to a second embodiment of the present invention.

[0077] In the membrane humidifier according to the second embodiment, the filter member 220 of the gas filter may be arranged in the first cassette 150 together with the plurality of hollow fiber membranes 160 .

[0078] The filter member 220 may be a type formed by coating the gas capture material 211 on the non-woven fabric 213 or a type formed by coating the gas capture material 212 on the outer peripheral surface of the yarn 214, such as Figure 3 shown.

[0079] exist Figure 4 In the embodiment of FIG. 1 , a plurality of hollow fiber membranes 160 and a plurality of filter members 220 are arranged together in each of the three first cassettes 150 such that the filter members are respectively interposed between the hollow fiber membranes and then potted together.

[0080] Low humidity air is introduced into the housing unit via the second fluid inlet 112, and then (i) is humidified while flowing along the inner cavity of the hollow fiber membrane 160, or (ii) is filtered while passing through the filter member 220. The humidified or filtered air comes out of each cartridge 150 and is then discharged via the second fluid outlet 113 to be supplied to the fuel cell stack.

[0081] Figure 5 is a cross-sectional view of a membrane humidifier according to a third embodiment of the present invention, Figure 6 is a schematic diagram of the structure of a gas filter installed in an intermediate housing of a membrane humidifier.

[0082] The membrane humidifier 100 according to the third embodiment includes a plurality of first cassettes 150 each having a plurality of hollow fiber membranes 160 therein, and a filter member 230 of a gas filter is installed in a housing unit in such a manner as to surround the first cassettes 150 together.

[0083] In the third embodiment, since the filter member 230 must have a shape capable of surrounding the plurality of first cases 150 at the same time, it may be formed by coating a gas capturing material on a non-woven fabric.

[0084] The gas capturing material may be the same material as described above, and preferably, the gas filter 230 has a sandwich structure in which the gas capturing material is interposed between non-woven fabrics.

[0085] Preferably, the filter member 230 is installed on the outer circumferential surface of the filter frame having a polygonal or circular tube shape. Figure 6 In an embodiment, the filter frame may include: a pair of main frame portions 235 defining the outer circumference of the quadrilateral tube, the main frame portions being disposed at opposite ends of the hollow fiber membrane; and a plurality of connecting frame portions 232 configured to connect the pair of main frame portions 235 to each other.

[0086] A filter fixing recess 236 may be formed in each of inner sides of a pair of main frame portions 235 facing each other, whereby an edge of the filter member 230 may be inserted into and fixed to the filter fixing recess 236 .

[0087] In addition, a sealing member 238 is preferably provided on the outer periphery of the main frame portion 235. The sealing member 238 may be made of an elastic material such as rubber, and may be compressed between the main frame portion 235 and the inner surface of the intermediate housing 110 so that a tight seal without any gap may be provided therebetween.

[0088] As described above, since the filter member 230 formed by coating the gas capture material on the non-woven fabric is installed in a wrapping frame manner, the shape of the filter member 230 can be constantly maintained and the gas filter 230 can be easily installed on the inner circumferential surface of the intermediate shell 110 or separated from the inner circumferential surface of the intermediate shell 110.

[0089] Figure 7 is a cross-sectional view of a membrane humidifier according to a fourth embodiment of the present invention, Figure 8 It is a schematic diagram showing a structure in which a gas filter is installed inside or outside a case of a membrane humidifier.

[0090] In the membrane humidifier according to the fourth embodiment, the filter member 240 of the gas filter may be installed over the inner circumferential surface or the outer circumferential surface of each of the plurality of first cassettes 150 in such a manner as to surround the plurality of hollow fiber membranes 160 .

[0091] Figure 7 and 8 (a) shows the filter member 240 installed on the inner circumferential surface of the first case 150. Since the filter member 240 must have a shape corresponding to the shape of the inner circumferential surface of the first case 150, it may be formed by coating a gas capturing material on a nonwoven fabric.

[0092] The first case 150 has a tube shape opened at opposite ends thereof. The mesh parts 152 are formed in at least two side surfaces of the first case so that the second fluid is introduced through one of the mesh parts 152 and discharged through the other mesh part 152 .

[0093] The module may be manufactured by inserting the filter member 240 into the first box 150 to install it on the inner circumferential surface of the first box 150, arranging a plurality of hollow fiber membranes 160 therein, and then potting the hollow fiber membranes 160, the filter member 240, and the first box 150 together. At this time, the filter member 240 may be installed in a manner of completely blocking the mesh portion 152 to ensure that the second fluid passes through the filter member 240 when introduced into or discharged from the first box 150.

[0094] according to Figure 8 In the fourth embodiment of the present invention shown in (b), the filter member 242 is installed on the outer peripheral surface of the first case 150. In this case, a plurality of filter members 242 may be installed on the outer side of the mesh portion 152 of the first case 150 in such a manner as to block the mesh portion 152 thereof.

[0095] Since the filter member 242 must have a shape corresponding to at least a portion of the outer circumferential surface of the first case 150, it may be formed by coating a gas capturing material on a non-woven fabric.

[0096] Although not shown, the first box 150 may be provided with a plurality of protruding ribs around the mesh portion 152 to allow the filter member 242 to be mounted thereon.

[0097] The module may be manufactured by mounting the filter member 242 on the outer circumferential surface of the first cassette 150 , arranging a plurality of hollow fiber membranes 160 therein, and packaging the hollow fiber membranes 160 , the first cassette 150 , and the filter member 242 together.

[0098] In the third and fourth embodiments, the gas capture material may be the same material as described in the previous embodiments.

[0099] Fig. 9 is a cross-sectional view of a membrane humidifier according to a fifth embodiment of the present invention, Fig.10 The diagram is a schematic diagram showing the structure of a gas filter installed between an intermediate housing and a cover housing of a membrane humidifier.

[0100] In the membrane humidifier according to the fifth embodiment, the filter member 250 of the gas filter is installed in the housing unit in such a manner that the first fluid introduced via the first fluid inlet 121 passes through the filter member 250 of the gas filter before being introduced into the inner cavity of the hollow fiber membrane 160 of the first cassette 150 .

[0101] As described above, the housing unit may be configured as a structure in which the intermediate housing 110 is coupled to a pair of cover housings 120. The filter member 250 of the gas filter may be detachably installed in the cover housing 120 having the first fluid inlet 121 or installed between the intermediate housing 110 and the cover housing 120 having the first fluid inlet 121.

[0102] For example, the filter member 250 may be installed in the cover housing 120 having the first fluid inlet 121 , and then the intermediate housing 110 in which the first cassette 150 is installed may be coupled to the cover housing 120 .

[0103] Although Fig. 9It is shown that only the cover housing 120 having the first fluid inlet 121 is provided with the filter member 250 therein, but the cover housing 120 having the first fluid outlet 122 may also be provided with the filter member 250 therein. If so, the filter member 250 can capture harmful gases from the first fluid introduced into the membrane humidifier 100, and can also capture harmful gases from the first fluid discharged from the membrane humidifier 100.

[0104] like Fig.10 As shown, the filter member 250 may include a filter portion formed by coating a gas capturing material on a non-woven fabric and a frame portion 255 coupled to the filter portion in such a manner as to surround the filter portion.

[0105] The frame portion 255 may have an overall polygonal or circular shape corresponding to a cross-sectional shape of the housing unit.

[0106] like Fig.10 As shown in the partially enlarged cross-sectional view of , the frame portion 255 may be provided in its inner circumferential surface with a filter fixing groove 256 into which the edge of the filter member 250 is to be inserted.

[0107] In addition, preferably, the filter member 150 further includes a sealing member 258, which is provided at the end of the frame portion 255, specifically provided at the end of the frame portion to be coupled to the cover housing 120 having the first fluid inlet 121. The sealing member 258 may be made of an elastic material such as rubber, and when the filter member 250 is installed inside the cover housing 120, the sealing member 258 may be compressed, thereby preventing any leakage of gas through the gap between the filter member 250 and the cover housing 120.

[0108] Hereinafter, the results of a performance test of a gas filter of the membrane humidifier according to the above-described embodiment will be described.

[0109] First, in each example, a membrane type filter member was fabricated as a gas filter by coating a polyethylene terephthalate (PET) nonwoven fabric having a thickness of 100 μm with PFSA, applying zeolite and niobium particles thereto, and then attaching the PET nonwoven fabric having a thickness of 100 μm thereto.

[0110] The filter member manufactured as described above is cut according to the shape of each embodiment.

[0111] [First embodiment]

[0112] A membrane humidifier including four boxes was manufactured by potting 250 filter components each cut into a size of 10 mm×300 mm in one box, and placing and potting hollow fiber membranes for humidification in the other three boxes. Subsequently, three types of dry air including 10 ppm of NH3, 10 ppm of NO3, and 10 ppm of SO2, respectively, were introduced into the membrane humidifier via the second fluid inlet 112, the gas discharged via the second fluid outlet 113 was captured, and the concentration of harmful gases therein was measured to determine the effect of the gas filter.

[0113] [Table 1]

[0114] Inflow gas concentration (ppm) Outflow gas concentration (ppm) <![CDATA[NH3]]> 10 3.6 <![CDATA[NO3]]> 10 6.2 <![CDATA[SO2]]> 10 5.8

[0115] As shown in Table 1, for harmful gases, the gas capture performance of the gas filter according to the first embodiment is 64%, 38% and 42%. It can be seen that the gas capture performance for NH3 is the best.

[0116] In addition, in order to evaluate the humidification performance, dry air (flow rate: 3500 sLPM, temperature: 80°C, relative humidity: 5 to 10% RH, absolute pressure: 1.8 bar) and humid air (flow rate: 3500 sLPM, temperature: 80°C, relative humidity: 80% RH, absolute pressure: 1.6 bar) were supplied to the membrane humidifier to perform humidification. The dew point of the humidified air discharged from the membrane humidifier was 54°C.

[0117] [Second embodiment]

[0118] A membrane humidifier including three cassettes was manufactured by placing and potting 80 filter members each cut to a size of 10 mm×300 mm together with a plurality of hollow fiber membranes in each cassette. Subsequently, the effect of the gas filter was determined using the same method as in the above-mentioned first embodiment.

[0119] [Table 2]

[0120] Outflow gas concentration (ppm) Outflow gas concentration (ppm) <![CDATA[NH3]]> 10 2.8 <![CDATA[NO3]]> 10 4.1 <![CDATA[SO2]]> 10 3.7

[0121] As shown in Table 2, for harmful gases, the gas capture performance of the gas filter according to the second embodiment is 72%, 59% and 63%. It can be seen that the gas capture performance for NH3 is the best.

[0122] Furthermore, evaluation of the humidification performance using the same method as in the above-described first embodiment revealed that the dew point of the humidified air discharged from the membrane humidifier was 56°C.

[0123] [Third embodiment]

[0124] A membrane humidifier including three cassettes was manufactured by installing a filter member cut into a size of 120 mm×460 mm between the housing unit and the three cassettes. Subsequently, the effect of the gas filter was determined using the same method as in the above-described first embodiment.

[0125] [Table 3]

[0126] Inflow gas concentration (ppm) Outflow gas concentration (ppm) <![CDATA[NH3]]> 10 0.9 <![CDATA[NO3]]> 10 1.1 <![CDATA[SO2]]> 10 1.3

[0127] As shown in Table 3, for harmful gases, the gas capture performance of the gas filter according to the third embodiment is 91%, 89% and 87%. It can be seen that the gas capture performance for NH3 is the best. The gas capture performance of the third embodiment is better than that of the first and second embodiments. The reason is that in the first and second embodiments, only a part of the introduced dry air passes through the gas filter, while the third embodiment is configured so that all the dry air passes through the gas filter.

[0128] Evaluation of the humidification performance using the same method as in the above-described first embodiment revealed that the dew point of the humidified air discharged from the membrane humidifier was 55°C.

[0129] [Fourth embodiment]

[0130] A membrane humidifier including three cassettes was manufactured by mounting a filter member cut into a size of 280 mm×220 mm on the inner circumferential surface of each cassette and potting it together with a bundle of hollow fiber membranes.

[0131] [Table 4]

[0132] Inflow gas concentration (ppm) Outflow gas concentration (ppm) <![CDATA[NH3]]> 10 0.6 <![CDATA[NO3]]> 10 0.7 <![CDATA[SO2]]> 10 0.6

[0133] As shown in Table 4, for harmful gases, the gas capture performance of the gas filter according to the fourth embodiment is 94%, 93% and 94%. It can be seen that the gas capture performance for NH3 and SO2 is the best. The gas capture performance of the fourth embodiment is better than that of the first and second embodiments. The reason is that in the first and second embodiments, only a part of the introduced dry air passes through the gas filter, while the fourth embodiment is configured so that all the dry air passes through the gas filter.

[0134] Evaluation of the humidification performance using the same method as in the above-described first embodiment revealed that the dew point of the humidified air discharged from the membrane humidifier was 56°C.

[0135] [Fifth embodiment]

[0136] A membrane humidifier including three boxes was manufactured by installing a filter member cut into a size of 170 mm×170 mm between a cover housing and an intermediate housing. Subsequently, three types of dry air including 10 ppm of NH3, 10 ppm of NO3, and 10 ppm of SO2, respectively, were introduced into the membrane humidifier via the first fluid inlet 121, the gas discharged via the first fluid outlet 122 was captured, and the concentration of harmful gases therein was measured to determine the effect of the gas filter.

[0137] [Table 5]

[0138] Inflow gas concentration (ppm) Outflow gas concentration (ppm) <![CDATA[NH3]]> 10 0.5 <![CDATA[NO3]]> 10 0.4 <![CDATA[SO2]]> 10 0.4

[0139] As shown in Table 5, for harmful gases, the gas capture performance of the gas filter according to the fifth embodiment is 95%, 96% and 96%. It can be seen that the gas capture performance for NO3 and SO2 is the best. The gas capture performance of the fifth embodiment is better than that of the first and second embodiments. The reason is that in the first and second embodiments, only a part of the introduced dry air passes through the gas filter, while the fifth embodiment is configured so that all the dry air passes through the gas filter.

[0140] Evaluation of the humidification performance using the same method as in the above-described first embodiment revealed that the dew point of the humidified air discharged from the membrane humidifier was 57°C.

[0141] In the first to fifth embodiments, the dew point of the humidified air exhausted from the membrane humidifier was 54 to 57° C., which shows that the embodiments have similar levels of humidification performance.

[0142] In the membrane humidifier for a fuel cell according to the present invention, a gas filter capable of capturing and filtering most of harmful gases contained in dry air while maintaining humidification performance may be integrated in the membrane humidifier.

Claims

1. A membrane humidifier for a fuel cell, the membrane humidifier comprising: a housing unit comprising a first fluid inlet for introducing a first fluid, a first fluid outlet for discharging the first fluid, a second fluid inlet for introducing a second fluid, and a second fluid outlet for discharging the second fluid, the first fluid introduced via the first fluid inlet having a lower humidity than the second fluid introduced via the second fluid inlet; a plurality of hollow fiber membranes disposed inside the housing unit in such a manner that water exchange occurs between the first fluid flowing along the inner lumens of the hollow fiber membranes and the second fluid flowing outside the hollow fiber membranes; as well as a first gas filter, the first gas filter being disposed in the housing unit, the first gas filter being configured to capture harmful gases contained in the first fluid, the harmful gases comprising nitrogen oxides, sulfur oxides, ammonia or a mixture of two or more thereof, Wherein, the first gas filter comprises: a first filter portion; and A first frame portion is coupled to the first filter portion in such a manner as to surround the first filter portion, the first frame portion is coupled to the housing unit and has an overall shape corresponding to a cross-sectional shape of the housing unit.

2. The membrane humidifier according to claim 1, wherein: The first filter unit comprises: Nonwoven fabrics; and A gas capture material is coated on the nonwoven fabric.

3. The membrane humidifier according to claim 2, wherein: The gas capture material is any one selected from the group consisting of biochar, charcoal, activated carbon, acidic polymer, zeolite, platinum, a mixture of copper sulfate and titanium sulfate, niobium, sodium bicarbonate, and a mixture of two or more thereof.

4. The membrane humidifier according to claim 3, wherein: The acidic polymer is selected from any one of the group consisting of perfluorosulfonic acid (PFSA), sulfonated polyethersulfone (S-PES), sulfonated polyarylethersulfone (S-PAES), sulfonated polystyrene (S-PS), sulfonated polyetherketone (S-PEK), sulfonated polyetheretherketone (S-PEEK) and a mixture of two or more thereof.

5. The membrane humidifier according to claim 1, wherein: The first frame portion is provided in an inner circumferential surface thereof with a filter fixing groove into which an edge of the first filter portion is inserted.

6. The membrane humidifier according to claim 1, wherein: The end portion of the first frame portion of the first gas filter coupled to the housing unit further includes a sealing member.

7. The membrane humidifier according to claim 6, wherein: The sealing member is made of an elastic material to prevent leakage of gas through a gap between the first gas filter and the housing unit.

8. The membrane humidifier according to claim 1, further comprising at least one first cartridge installed in the housing unit, the first cartridge having a plurality of hollow fiber membranes therein, in, The housing unit comprises: an intermediate housing, in which the first box is installed, and the intermediate housing is provided with the second fluid inlet and the second fluid outlet; a first cover housing coupled to one side of the intermediate housing, the first cover housing having the first fluid inlet; and a second cover housing, the second cover housing being coupled to the other side of the intermediate housing, the second cover housing having the first fluid outlet, and The first gas filter is installed in the first cover housing or between the first cover housing and the intermediate housing. 9 . The membrane humidifier according to claim 8 , further comprising a second gas filter installed in the second cover housing or between the second cover housing and the intermediate housing.

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