Cartridge for membrane humidifier and membrane humidifier for fuel cell including same

Abstract

A cartridge for a membrane humidifier capable of preventing a hollow fiber membrane housed in the cartridge from being damaged by a fluid, and a membrane humidifier for a fuel cell including the cartridge are disclosed. The cartridge for the membrane humidifier includes an inner case housing a hollow fiber membrane through which a first fluid flows, a potting portion for fixing an end of the hollow fiber membrane, a first mesh hole portion protruding from one side of the inner case into which a second fluid flows, and a second mesh hole portion protruding from the other side of the inner case into which the second fluid flows through the first mesh hole portion and is discharged after exchanging moisture with the first fluid through the hollow fiber membrane.

Description

[Technical Field]

[0001] The present invention relates to a cartridge for a membrane humidifier and a membrane humidifier for a fuel cell including the same, and more specifically to a cartridge for a membrane humidifier that can prevent a hollow fiber membrane contained in the cartridge from being damaged by a fluid, and a membrane humidifier for a fuel cell including the same. [Background technology]

[0002] A fuel cell is a power generating battery that generates electricity by combining hydrogen and oxygen. Unlike conventional chemical batteries such as dry batteries and storage batteries, a fuel cell can continuously generate electricity as long as hydrogen and oxygen are supplied, has the advantage of not losing heat, and is twice as efficient as an internal combustion engine. In addition, because the chemical energy generated by the combination of hydrogen and oxygen is directly converted into electrical energy, fuel cells emit fewer pollutants. Therefore, fuel cells are not only environmentally friendly, but also have the advantage of reducing concerns about resource depletion due to increased energy consumption. Such fuel cells can be broadly classified into polymer electrolyte membrane fuel cells (PEMFCs), phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs), solid oxide fuel cells (SOFCs), alkaline fuel cells (AFCs), and the like, depending on the type of electrolyte used. Although each of these fuel cells operates on the same fundamental principle, they differ in the type of fuel used, operating temperature, catalyst, electrolyte, etc. Among them, polymer electrolyte membrane fuel cells (PEMFCs) are known to be the most promising for use in small-scale stationary power generation equipment as well as transportation systems, as they operate at lower temperatures than other fuel cells, have high power density, and can be miniaturized. One of the most important factors in improving the performance of polymer electrolyte fuel cells (PEMFCs) is to maintain their efficiency by supplying a certain amount of moisture to the polymer electrolyte membrane (PEM or proton exchange membrane) of the membrane electrode assembly (MEA). If the PEM dries out, the power generation efficiency drops sharply. There are several methods for humidifying a polymer electrolyte membrane, including 1) a bubbler humidification method in which a pressure-resistant container is filled with water and the target gas is passed through a diffuser to supply moisture, 2) a direct injection method in which the amount of moisture required for the fuel cell reaction is calculated and moisture is supplied directly to the gas flow pipe via a solenoid valve, and 3) a humidification membrane method in which moisture is supplied to the gas flow bed using a polymer separation membrane. Among these, the membrane humidification method, which utilizes a membrane that selectively allows only water vapor contained in exhaust gas to pass through and provides water vapor to air supplied to the polymer electrolyte membrane to humidify the polymer electrolyte membrane, is advantageous in that it allows the membrane humidifier to be made lighter and smaller.

[0003] The selectively permeable membrane used in the membrane humidification method is preferably a hollow fiber membrane, which has a large permeation area per unit volume when forming a module. That is, when a membrane humidifier is manufactured using such a hollow fiber membrane, it is possible to highly integrate hollow fiber membranes with a large contact surface area, and it has the advantages of being able to sufficiently humidify the fuel cell even with a small capacity, being able to use low-cost materials, and being able to recover moisture and heat contained in the off-gas discharged at high temperature from the fuel cell and reuse it through the membrane humidifier. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide a cartridge for a membrane humidifier that can prevent a hollow fiber membrane housed in the cartridge from being damaged by a fluid, and a membrane humidifier for a fuel cell that includes the cartridge. [Means for solving the problem]

[0005] A cartridge for a membrane humidifier according to an embodiment of the present invention comprises: The device includes an inner case that houses hollow fiber membranes through which a first fluid flows, a potting portion that fixes an end of the hollow fiber membrane, a first mesh hole portion that protrudes from one side of the inner case and into which a second fluid flows, and a second mesh hole portion that protrudes from the other side of the inner case and into which the second fluid that flows in through the first mesh hole portion exchanges moisture with the first fluid through the hollow fiber membrane and is then discharged. In the cartridge for a membrane humidifier according to an embodiment of the present invention, the first mesh hole portion and the second mesh hole portion are protruded at a predetermined height from the surface of the inner case by a protruding support portion. In the cartridge for a membrane humidifier according to an embodiment of the present invention, the maximum possible movement distance due to the oscillation of the hollow fiber membrane is calculated based on the slack ratio when the hollow fiber membrane is wetted. When the vertical height of the protruding support part is set, the initial length of the hollow fiber membrane is 100, and the length of the extended hollow fiber membrane is a, the maximum possible movement distance b can be calculated as b = a(a + 200) / 2(a + 100). In the cartridge for a membrane humidifier according to an embodiment of the present invention, when the length of the hollow fiber membrane is 100, the vertical height of the protruding support portion is preferably formed to be 1 to 20. More preferably, the vertical height of the protruding support portion may be formed to be 1 to 5.

[0006] According to an embodiment of the present invention, a membrane humidifier for a fuel cell comprises: The device performs moisture exchange between a first fluid and a second fluid and includes a midcase, a second fluid inlet for introducing the second fluid into the midcase, a second fluid outlet for discharging the second fluid to the outside, and at least one cartridge disposed within the midcase and accommodating a plurality of hollow fiber membranes. The cartridge includes an inner case accommodating hollow fiber membranes through which the first fluid flows, a potting portion for fixing ends of the hollow fiber membranes, a first mesh hole portion protruding from one side of the inner case and into which the second fluid flows, and a second mesh hole portion protruding from the other side of the inner case and into which the second fluid flows via the first mesh hole portion and then displaces after exchanging moisture with the first fluid through the hollow fiber membranes. In the membrane humidifier for a fuel cell according to an embodiment of the present invention, the first mesh hole portion and the second mesh hole portion are protruded at a predetermined height from the surface of the inner case by a protruding support portion. In a membrane humidifier for a fuel cell according to an embodiment of the present invention, the maximum possible movement distance due to the oscillation of the hollow fiber membrane is calculated based on the slack rate when the hollow fiber membrane is wetted. When the vertical height of the protruding support part is set, the initial length of the hollow fiber membrane is 100, and the length of the extended hollow fiber membrane is a, the maximum possible movement distance b can be calculated as b = a(a + 200) / 2(a + 100). In the membrane humidifier for a fuel cell according to an embodiment of the present invention, when the length of the hollow fiber membrane is 100, the vertical height of the protruding support portion is preferably formed to be 1 to 20. More preferably, the vertical height of the protruding support portion may be formed to be 1 to 5. Further details of embodiments according to various aspects of the present invention are included in the following detailed description. [Effects of the Invention]

[0007] According to an embodiment of the present invention, by taking into consideration the maximum possible movement distance of the hollow fiber membrane oscillating due to the fluid, the mesh hole portions are protruded, thereby preventing the hollow fiber membrane from coming into contact with the mesh hole portions and preventing the hollow fiber membrane from being damaged by friction. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a front view illustrating a membrane humidifier for a fuel cell according to one embodiment of the present invention; [Figure 2] 1 is a plan view illustrating a membrane humidifier for a fuel cell according to one embodiment of the present invention; [Figure 3] FIG. 3 is a cross-sectional view taken along line AA' in FIG. 2. [Figure 4] 1 is a plan view illustrating a cartridge installed in a membrane humidifier of a fuel cell according to one embodiment of the present invention; [Figure 5] FIG. 5 is a cross-sectional view taken along the line BB′ in FIG. 4. [Figure 6] FIG. 5 is a cross-sectional view taken along the line CC' in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Although the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated and described in detail in the detailed description, but it should be understood that they do not limit the present invention to the specific embodiments, but include all modifications, equivalents, or alternatives that fall within the spirit and technical scope of the present invention. The terms used in the present invention are merely used to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as "comprise" or "have" specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Hereinafter, a membrane humidifier cartridge and a membrane humidifier for a fuel cell including the same according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view illustrating a membrane humidifier for a fuel cell according to one embodiment of the present invention, FIG. 2 is a plan view illustrating a membrane humidifier for a fuel cell according to one embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line A-A' in FIG. 2. As shown in FIGS. 1-3, a membrane humidifier for a fuel cell according to one embodiment of the present invention includes a humidification module 110 and a cap 120. The humidification module 110 includes a cap 120. The cap 120 includes a humidification module 110 and a cap 120. The cap 120 includes a humidification module 1 ... The humidification module 110 exchanges moisture between a first fluid supplied from the outside and a second fluid discharged from a fuel cell stack (not shown). Caps 120 are fastened to both ends of the humidification module 110. One of the caps 120 is formed with a first fluid inlet 121 for supplying the first fluid supplied from the outside to the humidification module 110, and the other is formed with a first fluid outlet 122 for supplying the first fluid humidified by the humidification module 110 to the fuel cell stack. The humidification module 110 includes a mid-case 111 having a second fluid inlet 112 and a second fluid outlet 113, and at least one cartridge 20 disposed within the mid-case 111. A second fluid discharged from a fuel cell stack (not shown) flows into the second fluid inlet 112, undergoes moisture exchange within the humidification module 110, and is then discharged through the second fluid outlet 113.

[0010] In this specification, the fluid flowing in / out of the second fluid inlet 112 or the second fluid outlet 113 is not limited to the second fluid. Also, the fluid flowing in / out of the first fluid inlet 121 or the first fluid outlet 122 is not limited to the first fluid. Depending on the design, one of the caps 120 can supply the second fluid to the humidification module 110 and cause it to flow inside the hollow fiber membrane, and the other can discharge the second fluid after moisture exchange to the outside. In this case, the first fluid flows in through either the second fluid inlet 112 or the second fluid outlet 113, and the first fluid humidified by the humidification module 110 is supplied to the fuel cell stack through the other one. The flow directions of the first fluid and the second fluid can be the same or opposite to each other. The midcase 111 and the cap 120 may each be independently formed of hard plastic or metal and have a circular or polygonal widthwise cross section. The circle includes an oval, and the polygon includes a polygon with rounded corners. For example, the hard plastic may be polycarbonate, polyamide (PA), polyphthalamide (PPA), polypropylene (PP), etc. The internal space of the midcase 111 may be divided into a first space S1 and a second space S2 by a partition wall 114.

[0011] Figure 4 is a plan view illustrating a cartridge to be installed in a membrane humidifier of a fuel cell according to one embodiment of the present invention, Figure 5 is a cross-sectional view taken along line B-B' in Figure 4, and Figure 6 is a cross-sectional view taken along line C-C' in Figure 4. 4 to 6, a cartridge 20 for a membrane humidifier according to an embodiment of the present invention includes a plurality of hollow fiber membranes 21, a potting portion 22, and an inner case . The hollow fiber membrane 21 also includes a polymer membrane formed from polysulfone resin, polyethersulfone resin, sulfonated polysulfone resin, polyvinylidene fluoride (PVDF) resin, polyacrylonitrile (PAN) resin, polyimide resin, polyamideimide resin, polyesterimide resin, or a mixture of at least two or more of them. The potting portion 22 fixes the end of the hollow fiber membrane 21. The potting portion 22 can be formed by hardening a liquid resin such as a liquid polyurethane resin through a casting method such as dip potting or centrifugal potting. The inner case 23 has openings at each end and accommodates a number of hollow fiber membranes 21 inside. Potting portions 22, to which the ends of the hollow fiber membranes 21 are potted, close the openings of the inner case 23. The inner case 23 has first mesh holes MH1 arranged in a mesh shape for fluid communication with the first space S1, and second mesh holes MH2 arranged in a mesh shape for fluid communication with the second space S2. The second fluid that flows into the first space S1 of the midcase 111 through the second fluid inlet 112 flows into the inner case 23 through the first mesh hole portion MH1, which has a plurality of windows W formed therein, and comes into contact with the outer surface of the hollow fiber membrane 21. Subsequently, the second fluid that has exchanged moisture with the first fluid flows into the second space S2 through the second mesh hole portion MH2, which has a plurality of windows W formed therein, and is then discharged from the midcase 111 through the second fluid outlet 113.

[0012] If the flow direction of the second fluid is opposite to the flow direction of the first fluid flowing into the first fluid inlet 121, the second fluid that flows into the second space S2 of the midcase 111 through the second fluid outlet 113 flows into the inner case 23 through the second mesh hole portion MH2 and comes into contact with the outer surface of the hollow fiber membrane 21. Subsequently, the second fluid that has exchanged moisture with the first fluid flows through the first mesh hole portion MH1 into the first space S1 and is then discharged from the midcase 111 through the second fluid inlet 112. In a conventional membrane humidifier cartridge, the first mesh hole portion MH1 and the second mesh hole portion MH2 are formed on the same plane as the inner case 23. With this structure, the hollow fiber membrane 21 housed inside the inner case 23 oscillates in the direction of the fluid flow due to the second fluid flowing into the inner case 23 through the first mesh hole portion MH1. As the hollow fiber membrane 21 oscillates, it repeatedly comes into contact with the first mesh hole portion MH1, causing damage (scratches, breaks, etc.) due to friction. This also occurs when the second fluid is discharged to the outside through the second mesh hole portion MH2. In order to prevent such damage to the hollow fiber membrane 21, in the present invention, at least one of the first mesh hole portion MH1 and the second mesh hole portion MH2 is protruded to a predetermined height on one side or the other side of the inner case 23. At this time, the first mesh hole portion MH1 and the second mesh hole portion MH2 are provided by the protruding support portion 24 to protrude at a predetermined height from the surface of the inner case 23. The maximum possible movement distance of the hollow fiber membrane 21 due to oscillation can be calculated based on the slack ratio when the hollow fiber membrane 21 is wet, and the vertical height of the protruding support portion 24 can be set based on this calculation. The slack ratio refers to the ratio of the length of the hollow fiber membrane in a wet state to the initial design length of the hollow fiber membrane in a dry state. When the initial length of the hollow fiber membrane is 100 and the length of the hollow fiber membrane to which it has been extended is a, the maximum movable distance b (maximum movable height) can be calculated as b = a(a + 200) / 2(a + 100). Considering such a slack ratio, when the length of the hollow fiber membrane 21 is 100, it is desirable that the vertical height of the protruding support portion 24 is formed to a height of 1 to 20. Since it is related to a ratio, the unit of length is not particularly limited.

[0013] If the vertical height of the protruding support portion 24 is less than 1, the hollow fiber membrane 21 will repeatedly come into contact with the mesh hole portions MH1 and MH2 during operation, causing damage due to friction. If the vertical height of the protruding support portion 24 exceeds 20°, the efficiency of air permeating into the cartridge decreases. When the slack rate is taken into consideration, the actual movement range of the hollow fiber membrane 21 is mostly between 1 and 5 (this movement range is not limited to this), and if the vertical height of the protruding support part 24 exceeds 5, the volume of the cartridge 20 becomes excessively large, which causes a problem that the size of the membrane humidifier becomes correspondingly large. Therefore, when these factors are taken into consideration, it is more desirable that the vertical height of the protruding support part 24 be formed to a height of 1 to 5.

[0014] In this way, the cartridge for a membrane humidifier of the present invention takes into consideration the maximum possible movement distance of the hollow fiber membrane oscillating due to the second fluid, and by providing protruding mesh holes, it is possible to prevent the hollow fiber membrane from coming into contact with the mesh holes and prevent the hollow fiber membrane from being damaged by friction. Although the embodiments of the present invention have been described above, a person having ordinary knowledge in the art can modify and change the present invention in various ways by adding, changing, deleting or adding components within the scope of the concept of the present invention as set forth in the claims, and these modifications and changes are also within the scope of the present invention.

Claims

1. an inner case containing a hollow fiber membrane through which a first fluid flows; a potting portion for fixing an end of the hollow fiber membrane; a first mesh hole portion into which a second fluid flows and which protrudes from a surface of one end side of the inner case in a direction away from an outer surface of the hollow fiber membrane; a second mesh hole portion protruding from the surface of the other end side of the inner case in a direction away from the outer surface of the hollow fiber membrane, through which the second fluid flowing in through the first mesh hole portion exchanges moisture with the first fluid through the hollow fiber membrane and is then discharged.

2. 2. The cartridge for a membrane humidifier according to claim 1, wherein the first mesh hole portion and the second mesh hole portion are protruded at a predetermined height from the surface of the inner case by a protruding support portion.

3. a maximum possible movement distance due to the oscillation of the hollow fiber membrane is calculated based on a slack rate when the hollow fiber membrane is wetted, and a vertical height of the protruding support part is set; 3. The cartridge for a membrane humidifier according to claim 2, wherein the maximum movable distance b is calculated as b = a(a + 200) / 2(a + 100), where the initial length of the hollow fiber membrane is 100 and the length of the hollow fiber membrane after extension is a.

4. When the length of the hollow fiber membrane is 100, The cartridge for a membrane humidifier according to claim 2, wherein the vertical height of the protruding support portion is formed to a height of 1 to 20 mm.

5. The cartridge for a membrane humidifier according to claim 4, wherein the vertical height of the protruding support portion is formed to a height of 1 to 5.

6. performing moisture exchange between the first fluid and the second fluid; Mid case and a second fluid inlet for allowing the second fluid to flow into the midcase; a second fluid outlet for discharging the second fluid to the outside; At least one cartridge disposed in the midcase and containing a plurality of hollow fiber membranes; The cartridge comprises: an inner case containing a hollow fiber membrane through which a first fluid flows; a potting portion for fixing an end of the hollow fiber membrane; a first mesh hole portion into which a second fluid flows and which protrudes from a surface of one end side of the inner case in a direction away from an outer surface of the hollow fiber membrane; a second mesh hole portion protruding from the surface of the other end side of the inner case in a direction away from the outer surface of the hollow fiber membrane, through which the second fluid flowing in through the first mesh hole portion exchanges moisture with the first fluid through the hollow fiber membrane and is then discharged.

7. 7. The membrane humidifier for a fuel cell according to claim 6, wherein the first mesh hole portion and the second mesh hole portion are protruded at a predetermined height from the surface of the inner case by a protruding support portion.

8. a maximum possible movement distance due to the oscillation of the hollow fiber membrane is calculated based on a slack rate when the hollow fiber membrane is wetted, and a vertical height of the protruding support part is set; 8. The membrane humidifier for a fuel cell according to claim 7, wherein the maximum movable distance b is calculated as b = a(a + 200) / 2(a + 100), where the initial length of the hollow fiber membrane is 100 and the length of the hollow fiber membrane after extension is a.

9. When the length of the hollow fiber membrane is 100, 8. The membrane humidifier for a fuel cell according to claim 7, wherein the vertical height of the protruding support part is formed to a height of 1 to 20 mm.

10. 10. The membrane humidifier for a fuel cell according to claim 9, wherein the vertical height of the protruding support part is formed to a height of 1 to 5 mm.

Images