FUEL CELL MEMBRANE HUMIDIFIER PREVENTING DAMAGE OF HUMIDIFICATION MEMBRANE

Abstract

The present invention relates to a fuel cell membrane humidifier capable of preventing humidification membranes from being damaged by pressure of exhaust gas, and a fuel cell membrane humidifier according to an embodiment of the present invention comprises: a humidification module for humidifying air supplied from the outside by using water in exhaust gas discharged from a fuel cell stack; and caps coupled to opposite ends of the humidification module, respectively, wherein the humidification module comprises: a mid-case including an exhaust gas inlet through which the exhaust gas is introduced; at least one cartridge disposed in the mid-case to receive multiple humidification membranes; and a humidification membrane protection member formed on an inner wall of the mid-case through which the exhaust gas inlet is formed and inclined toward the cartridge to thus prevent the exhaust gas from coming into direct contact with the humidification membrane.

Claims

1. A fuel cell membrane humidifier comprising: a humidification module configured to humidify air supplied from the outside with moisture in an off-gas discharged from a fuel cell stack; and caps coupled to both ends of the humidification module, respectively, wherein the humidification module includes a mid-case having an off-gas inlet, the off-gas flowing into the inside through the off-gas inlet; at least one cartridge disposed inside the mid-case and configured to accommodate a plurality of humidification membranes; and a humidification membrane protection member formed to be inclined toward the cartridge on an inner wall of the mid-case having the off-gas inlet formed therein, to prevent the off-gas from come into direct contact with the humidification membranes.

2. The fuel cell membrane humidifier of claim 1, wherein the humidification membrane protection member includes a protection member body formed to be inclined at the preset angle toward the cartridge on the inner wall of the mid-case.

3. The fuel cell membrane humidifier of claim 2, wherein the humidification membrane protection member includes at least one flow hole formed in the protection member body.

4. The fuel cell membrane humidifier of claim 3, wherein the flow hole is formed not to be parallel to a direction of the off-gas inlet.

5. The fuel cell membrane humidifier of claim 3, wherein the flow hole is formed to be perpendicular to a direction of the protection member body.

6. The fuel cell membrane humidifier of claim 1, wherein the humidification membrane is a hollow fiber membrane formed of a hollow membrane having an empty inside.

7. The fuel cell membrane humidifier of claim 1, wherein the humidification membrane is a flat membrane formed of a pair of opposing membrane sheets.

8. The fuel cell membrane humidifier of claim 1, wherein the cartridge accommodates a plurality of hollow fiber membranes, the fuel cell membrane humidifier further comprises a gasket assembly airtightly coupled to each end of the humidification module through mechanical assembly.

9. The fuel cell membrane humidifier of claim 8, wherein the gasket assembly includes a packing portion configured to have a hole, an end of the cartridge being inserted into the hole, and come into close contact with the end of the cartridge inserted into the hole to absorb a vibration in a horizontal direction; an edge portion formed to be connected to the packing portion and interposed in a space formed by a groove formed at an end of the mid-case and an end of the cap; and a sealing portion formed between the cartridge and the portion to come into contact with the cartridge and the packing portion.

10. The fuel cell membrane humidifier of claim 9, wherein the packing portion includes a body member having a hole formed therein, an end of the cartridge being inserted into the hole; and a protrusion member formed at one end of the body member and in close contact with the end of the cartridge inserted into the hole.

11. The fuel cell membrane humidifier of claim 9, wherein the cartridge includes an inner case having openings formed at ends thereof, the plurality of hollow fiber membranes being accommodated in the inner case; and potting portions configured to close the openings of the inner case, ends of the plurality of hollow fiber membranes being fixed to the potting portion.

12. The fuel cell membrane humidifier of claim 9, wherein at least a part of the potting portion is located outside the inner case, and the protrusion member is pressed against and comes in close contact with the potting portion.

13. The fuel cell membrane humidifier of claim 11, wherein the entire potting portion is located inside the inner case, and the protrusion member is pressed against and comes in close contact with the inner case.

14. The fuel cell membrane humidifier of claim 11, wherein the edge portion includes edge wings protruding in both directions, and the edge wings are interposed with the groove formed at the end of the mid-case filled with the edge wings to seal the inside and outside of the mid-case, the mid-case, and the cap.

15. The fuel cell membrane humidifier of claim 11, wherein each of the packing portion and the edge portion has a first hardness of 30 to 70 Shore A, and the fuel cell membrane humidifier further comprises a reinforcing member formed to be inserted into at least a part of the packing portion and at least a part of the edge portion, the reinforcing member having a second hardness higher than the first hardness.

16. The fuel cell membrane humidifier of claim 9, wherein the humidification module includes two or more cartridges, the gasket assembly includes two or more holes into which the two or more cartridges are inserted.

17. The fuel cell membrane humidifier of claim 16, wherein the gasket assembly include two or more protrusion members.

18. The fuel cell membrane humidifier of claim 16, further comprises two or more sealing portions formed between the cartridge and the packing portion to come into contact with the cartridge and the packing portion.

19. The fuel cell membrane humidifier of claim 1, wherein the mid-case and the cap are independently formed of hard plastic or metal.

20. The fuel cell membrane humidifier of claim 1, wherein the mid-case and the cap have a cross section in a width direction having a circular or polygonal shape.

Description

DESCRIPTION OF DRAWINGS

[0033] FIG. 1 is an exploded perspective view illustrating a fuel cell membrane humidifier according to the related art.

[0034] FIG. 2 is an exploded perspective view illustrating a fuel cell membrane humidifier according to a first embodiment of the present invention.

[0035] FIG. 3 is an exploded cross-sectional view illustrating the fuel cell membrane humidifier according to the first embodiment of the present invention.

[0036] FIG. 4 is a combined cross-sectional view of the fuel cell membrane humidifier according to the first embodiment of the present invention.

[0037] FIG. 5 is a partial cross-sectional view illustrating an operating state of the fuel cell membrane humidifier according to the first embodiment of the present invention.

[0038] FIG. 6 is a combined cross-sectional view illustrating a fuel cell membrane humidifier according to a modification example of the first embodiment of the present invention.

[0039] FIG. 7 is an exploded perspective view illustrating a fuel cell membrane humidifier according to a second embodiment of the present invention.

[0040] FIG. 8 is an exploded cross-sectional view illustrating the fuel cell membrane humidifier according to the second embodiment of the present invention.

[0041] FIG. 9 is a combined cross-sectional view illustrating the fuel cell membrane humidifier according to the second embodiment of the present invention.

[0042] FIG. 10 is a combined cross-sectional view illustrating a fuel cell membrane humidifier according to a modification example of the second embodiment of the present invention.

MODE FOR DISCLOSURE

[0043] Since various changes may be made to the present invention, which may have several embodiments, specific embodiments will be illustrated and described in detail herein. However, it will be understood that this is not intended to limit the present invention to the specific embodiments, and all changes, equivalents, or substitutions included in the spirit and scope of the present invention are included.

[0044] The terms used herein are used for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular expressions a, an and the include the plural expressions, unless the context clearly indicates otherwise. It will be understood that the terms include or have herein specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described herein, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof. Hereinafter, a fuel cell membrane humidifier preventing damage to a humidification membrane according to embodiments of the present invention will be described with reference to the drawings.

[0045] FIG. 2 is an exploded perspective view illustrating a fuel cell membrane humidifier according to a first embodiment of the present invention, FIG. 3 is an exploded cross-sectional view illustrating the fuel cell membrane humidifier according to the first embodiment of the present invention, FIG. 4 is a combined cross-sectional view of the fuel cell membrane humidifier according to the first embodiment of the present invention, and FIG. 5 is a partial cross-sectional view illustrating an operating state of the fuel cell membrane humidifier according to the first embodiment of the present invention.

[0046] Referring to FIGS. 2 to 5, the fuel cell membrane humidifier 100 according to the first embodiment of the present invention includes a humidification module 110, caps 120, a gasket assembly 130, and a humidification membrane protection member 140.

[0047] The humidification module 110 humidifies air supplied from the outside with moisture in an off-gas discharged from a fuel cell stack. Both ends of the humidification module 110 are coupled to the caps 120. One of the caps 120 supplies the air supplied from the outside to the humidification module 110, and the other supplies the air humidified by the humidification module 110 to the fuel cell stack. The gasket assembly 130 is airtightly coupled to each end of the humidification module 110 through mechanical assembly. The humidification membrane protection member 140 prevents the humidification membrane from being damaged due to direct contact of the off-gas flowing into the inside through the off-gas inlet 111a with the humidification membrane.

[0048] The humidification membranes are roughly classified into hollow fiber membranes and flat membranes. The hollow fiber membrane is a hollow membrane having an empty inside, and a gas flows through a hollow channel. The flat membrane is formed of a pair of opposing membrane sheets, and a spacer is disposed between the pair of membrane sheets to form a channel while preventing the membrane sheets from coming into contact with each other. The gas flows through the channel between the membrane sheets. Hereinafter, an example in which the humidification membrane is a hollow fiber membrane will be described, but the same may apply to a case in which the humidification membrane is the flat membrane.

[0049] The humidification module 110 is a device in which moisture exchange between the air supplied from the outside and an off-gas occurs, and may include a mid-case 111 having an off-gas inlet 111a and an off-gas outlet 111b, and at least one cartridge 112 disposed in the mid-case 111.

[0050] The mid-case 111 and the cap 120 may be independently formed of hard plastic or metal, and may have a cross section in a width direction having a circular or polygonal shape. The circular shape includes an oval shape, and the polygonal shape includes a polygonal shape with rounded corners. Examples of the hard plastic may include polycarbonate, polyamide (PA), polyphthalamide (PPA), and polypropylene (PP). The inner space of the mid-case 111 may be partitioned into a first space S1 and a second space S2 by partition walls 111c.

[0051] The cartridge 112 may include a plurality of hollow fiber membranes 112a and a potting portion 112b that fixes the hollow fiber membranes 112a to each other. Ends of the hollow fiber membranes 112a may be fixed to the potting portion 112b.

[0052] Further, the cartridge 112 may further include an inner case 112c. The inner case 112c has an opening at each end, and the hollow fiber membranes 112a are accommodated therein. The potting portion 112b in which ends of the hollow fiber membranes 112a are potted closes the openings of the inner case 112c.

[0053] As in FIG. 3, at least a part of the potting portion 112b may be located outside the inner case 112c, and a protrusion member 131b of the gasket assembly 130 may come into close contact with the potting portion 112b. Alternatively, as in FIG. 6, the entire potting portion 112b may be located inside the inner case 112c and the protrusion member 131b of the gasket assembly 130 may come into close contact with the inner case 112c rather than the potting portion 112b.

[0054] The inner case 112c includes a plurality of holes (hereinafter referred to as first mesh holes) MH1 arranged in a mesh form for fluid communication with the first space S1, and a plurality of holes (hereinafter referred to as second mesh holes) MH2 arranged in a mesh form for fluid communication with the second space S2.

[0055] An off-gas flowing into the first space S1 of the mid-case 111 through the off-gas inlet 111a flows into the inner case 112c through the first mesh holes MH1 and comes into contact with outer surfaces of the hollow fiber membranes 22. Subsequently, the off-gas deprived of moisture exits into the second space S2 through the second mesh hole MH2, and then, is discharged from the mid-case 111 through the off-gas outlet 111b. Such a cartridge 112 including the inner case 112c has an advantage that the cartridge 112 can be easily assembled to the mid-case 111 and can be easily replaced.

[0056] The hollow fiber membranes 112a may include a polymer membrane formed of a polysulfone resin, a polyethersulfone resin, a sulfonated polysulfone resin, a polyvinylidene fluoride (PVDF) resin, a polyacrylonitrile (PAN) resin, a polyimide resin, a polyamideimide resin, a polyesterimide resin, or a mixture of two or more of these, and the potting portions 112b may be formed by curing a liquid resin such as a liquid polyurethane resin through a casting scheme such as deep potting or centrifugal potting.

[0057] The gas supplied from the outside flows along hollows of the hollow fiber membranes 112a. The off-gas flowing into the mid-case 111 through the off-gas inlet 111a comes into contact with outer surfaces of the hollow fiber membranes 112a and then is discharged from the mid-case 111 through the off-gas outlet 111b. When the off-gas comes into contact with the outer surfaces of the hollow fiber membranes 112a, moisture contained in the off-gas permeates the hollow fiber membranes 112a to humidify the air flowing along the hollows of the hollow fiber membranes 112a.

[0058] The gasket assembly 130 may be airtightly coupled to each end of the humidification module 110 through mechanical assembly. Since air leakage between the mid-case 111 and the cap 120 is prevented through mechanical assembly of the gasket assembly 130, a casting process (that is, a process of injecting a liquid resin into a mold and curing the liquid resin), an additional sealing process (that is, a process of applying and curing a sealant), and the like of the related art can be omitted.

[0059] Further, the gasket assembly 130 is mounted on the humidification module 100 through mechanical assembly, and thus, when an abnormality occurs in a specific part (for example, the cartridge 112) of the humidification module 110, it is possible to simply mechanically separate the gasket assembly 130 from the humidification module 110, and then repair or replace only the part.

[0060] Referring to FIG. 3, the gasket assembly 130 includes a packing portion 131, an edge portion 132, and a sealing portion 133. The packing portion 131 and the edge portion 132 may be formed of an elastic material (for example, silicone or rubber) having a first hardness of 20 to 70 Shore A and, preferably, 30 to 60 Shore A. The sealing portion 133 may include at least one of a solid sealing material and a liquid sealing material. The solid sealing material may be made of a material such as silicone, acrylic rubber, EPDM, or NBR, and the liquid sealing material may be made of a material such as silicone or urethane.

[0061] The packing portion 131 includes a hole H into which the end (for example, the potting portion 112b) of the cartridge 112 is inserted, and is interposed between the mid-case 111 and the cartridge 112. The packing portion 131 includes a body member 131a and the protrusion member 131b.

[0062] The body member 131a includes a hole H into which the end (for example, the potting portion 112b) of the cartridge 112 is inserted, and the hole H is formed in a shape corresponding to that of the end of the cartridge 112. A lower body member 131aa formed to protrude from the body member 131a to the mid-case 111 may have a cross section formed in a polygonal shape (for example, a trapezoidal shape), and an upper body member 13 lab formed toward the cap 120 may be formed in a planar shape. A space in which the sealing portion 133 is disposed is formed between the lower body member 131aa and the cartridge potting portion 112b. Further, a groove G into which an end 111d of the mid-case 111 is fitted is formed between the lower body member 131aa and the edge portion 132.

[0063] The protrusion member 131b is formed at one end of the body member 131a to come into contact with the cartridge potting portion 112b inserted into the hole H. The protrusion member 131b may be at least one annular protrusion protruding from the one end of the body member 131a. The protrusion member 131b may press and come into contact with the cartridge potting portion 112b according to an elastic force to make a space of the mid-case 111 and a space of the cap 120 airtight. Therefore, the protrusion member 131b can prevent a fluid in the mid-case 111 from flowing into the space formed on the cap 120 side. Further, since the protrusion member 131b has elasticity, the protrusion member 131b can perform a vibration dampening function, and thus, prevent the humidifier 100 from being damaged by a vibration.

[0064] The edge portion 132 is formed at the other end of the body member 131a. The edge portion 132 may be interposed in a space formed by a groove 111e formed at an end of the mid-case and an end 120a of the cap. The edge portion 132 may include edge wings 132a and 132b protruding in both directions. The edge wings 132a and 132b may be formed in a longitudinal direction of the humidification module 110. When assembling is performed, the edge wings 132a and 132b are inserted into the groove 111e at the end of the mid-case, the edge wing 132b is pressed by the end 120a of the cap, and then, assembly may be performed by fastening using a fastening means such as a bolt B. In this case, since the edge wings 132a and 132b are made of an elastic material, the edge wings 132a and 132b may be interposed with a space of the groove 111e at the end of the mid-case partially filled with the edge wings 132a and 132b. Fastening fragments 111f and 120b having fastening holes for bolt fastening may be formed on side surfaces of ends of the mid-case 111 and the cap 120. The edge wings 132a and 132b may make the groove 111e at the end of the mid-case airtight to seal the inside and outside of the mid-case 111, and the mid-case 111, and the cap 120.

[0065] The sealing portion 133 is formed between the cartridge 112 and the packing portion 131 to come into contact with the cartridge 112 and the packing portion 131. Specifically, the sealing portion 133 is formed to simultaneously come into contact with (or adhere to) the potting portion 112b of the cartridge and the lower body member 131aa of the packing portion. The sealing portion 133 makes the space of the mid-case 111 and the space of the cap 120 airtight to prevent a fluid in the mid-case 111 from flowing toward the cap 120.

[0066] Further, the gasket assembly 130 may further include a reinforcing member 134. The reinforcing member 134 may have a second hardness higher than the first hardness. For example, the reinforcing member 134 may be formed of metal, a thermoplastic or thermosetting resin, or the like. The reinforcing member 134 may be formed to be inserted into the gasket assembly 130 by being manufactured after a metal plate is inserted into a mold at the time of molding of the gasket assembly 130. The reinforcing member 134 may be formed to be inserted into at least a part of the packing portion 131 and at least a part of the edge portion 132. The reinforcing member 134 may be formed at a portion of the gasket assembly 130 that is vulnerable to deformation (a portion in which the groove G is formed). The reinforcing member 134 having a hardness higher than the packing portion 131 and the edge portion 132 can prevent the body member 131a from being deformed when the gasket assembly 130 is mechanically assembled into the humidification module 110 or while the humidifier is operating, to suppress air leakage more reliably.

[0067] The humidification membrane protection member 140 may be formed to be inclined at a preset angle toward the cartridge 112 on an inner wall of the mid-case 111 in which the off-gas inlet 111a is formed.

[0068] Referring to FIG. 5, the off-gas flowing into the inside through the off-gas inlet 111a may flow into the first mesh holes MH1 while being guided by the humidification membrane protection member 140. Since the off-gas primarily collides with the humidification membrane protection member 140 to lose some pressure, and then, flows into the first mesh holes MH1, the hollow fiber membranes accommodated inside the cartridge 112 come into contact with the off-gas subjected to the pressure loss. Therefore, the humidification membrane protection member 140 can prevent the off-gas flowing into the inside through the off-gas inlet 111a from coming into direct contact with the hollow fiber membranes and damaging the hollow fiber membranes.

[0069] Specifically, the humidification membrane protection member 140 may include a protection member body 141 formed to be inclined at the preset angle toward the cartridge 112 on the inner wall of the mid-case 111, and a predetermined number of flow holes 142 formed in the protection member body 141. The flow holes 142 are not essential. That is, it is possible to prevent the hollow fiber membranes from being damaged only with the protection member body 141. However, when there is only the protection member body 141, there is a concern that the pressure loss of the off-gas is excessive, and thus, when the flow holes 142 are optionally formed, it is possible to reduce the pressure loss of the off-gas while preventing the hollow fiber membranes from being damaged by the off-gas, and improve the humidification efficiency. In this case, when directions of the flow holes 142 are parallel to a direction of the off-gas inlet 111a, a high-pressure off-gas comes into direct contact with the hollow fiber membranes, and thus, it is preferable for the flow holes 142 to be formed so that the directions of the flow holes 142 are not parallel to the direction of the off-gas inlet 111a. More preferably, the direction of the flow hole 142 may be perpendicular to a direction of the protection member body 141.

[0070] FIG. 6 is a combined cross-sectional view illustrating a fuel cell membrane humidifier according to a modification example of the first embodiment of the present invention. Referring to FIG. 6, the fuel cell membrane humidifier 100a according to the modification example of the first embodiment of the present invention is substantially the same as the fuel cell membrane humidifier 100 according to the first embodiment described above except that the entire potting portion 112b is located inside the inner case 112c, and the protrusion member 131b of the gasket assembly 130 comes into close contact with the inner case 112c rather than the potting portion 112b.

[0071] Next, a fuel cell membrane humidifier according to a second embodiment of the present invention will be described with reference to FIGS. 7 to 9. FIG. 7 is an exploded perspective view illustrating the fuel cell membrane humidifier according to the second embodiment of the present invention, FIG. 8 is an exploded cross-sectional view illustrating the fuel cell membrane humidifier according to the second embodiment of the present invention, and FIG. 9 is a combined cross-sectional view illustrating the fuel cell membrane humidifier according to the second embodiment of the present invention.

[0072] As illustrated in FIGS. 7 to 9, the fuel cell membrane humidifier 200 according to the second embodiment of the present invention is substantially the same as the fuel cell membrane humidifier 100 according to the first embodiment described above except that (i) the humidification module 110 includes two or more cartridges 212, and (ii) the gasket assembly 230 includes two or more holes H into which the two or more cartridges 212 are inserted.

[0073] In this case, the gasket assembly 230 may include two or more protrusion members 131b (see FIG. 3) formed at one end of the body member 131a (see FIG. 3) to come into contact with a cartridge potting portion 212b, and two or more sealing portions 133 (see FIG. 3) formed between the cartridge 212 and the packing portion 131 (see FIG. 3) to come into contact with the cartridge 212 and the packing portion 131.

[0074] A plurality of cartridges 212 each including an inner case 212c are mounted inside the mid-case 111 at regular intervals, making it possible not only to uniformly distribute the off-gas to all hollow fiber membranes 212a present inside the mid-case 111, but also to selectively replace only a specific cartridge 212 in which a problem occurs, thereby further reducing maintenance costs of the fuel cell membrane humidifier 200.

[0075] FIG. 10 is a combined cross-sectional view illustrating a fuel cell membrane humidifier according to a modification example of the second embodiment of the present invention. Referring to FIG. 10, the fuel cell membrane humidifier 200a according to the modification example of the second embodiment of the present invention is substantially the same as the fuel cell membrane humidifier 200 according to the second embodiment described above except that the entire potting portion 212b is located inside the inner case 212c, and the protrusion member of the gasket assembly 230 comes into close contact with the inner case 212c rather than the potting portion 212b.

[0076] Although the embodiment of the present invention has been described above, those skilled in the art can variously modify or change the present invention through affixation, change, deletion, addition, or the like of components without departing from the spirit of the present invention described in the claims, and this will be said to be also included within the scope of the present invention.

DETAILED DESCRIPTION OF MAIN ELEMENTS

[0077] 100, 100a, 200, 200a: fuel cell membrane humidifier [0078] 110: humidification module 111: mid-case [0079] 111a: off-gas inlet 111b: off-gas outlet [0080] 111c: partition wall 112, 212: cartridge [0081] 112a, 212a: hollow fiber membrane 112b, 212b: potting portion [0082] 112c, 212c: inner case 120: cap [0083] 130, 230: gasket assembly [0084] 140: humidification membrane protection member 141: protection member body [0085] 142: flow hole