Automatic flow rate control cartridge and fuel cell membrane humidifier including same

Abstract

The present invention relates to an automatic flow rate control cartridge that can automatically control the flow rate of exhaust gas discharged from a fuel cell stack and flowing into the cartridge, and a fuel cell membrane humidifier including the same, The automatic flow rate regulating cartridge according to an embodiment of the present invention includes: The fuel cell stack is provided with an inner case having a first mesh hole portion through which exhaust gas discharged from the fuel cell stack flows in and a second mesh hole portion through which the exhaust gas that flows in through the first mesh hole portion is discharged to the outside after exchanging moisture therewith, and a flow rate adjustment portion that is movably formed on one surface of the inner case and adjusts the flow rate of exhaust gas flowing into the first mesh hole portion depending on the exhaust gas flow rate.

Description

[Technical field]

[0001] The present invention relates to a cartridge and a fuel cell membrane humidifier including the same, and more particularly to an automatic flow rate adjusting cartridge that can automatically adjust the flow rate of exhaust gas discharged from a fuel cell stack and flowing into the cartridge, and a fuel cell membrane humidifier including the same. [Background technology]

[0002] A fuel cell is a power generating battery that produces electricity by combining hydrogen and oxygen. Unlike ordinary chemical batteries such as dry batteries and storage batteries, fuel cells can continue to produce electricity as long as hydrogen and oxygen are supplied, and because there is no heat loss, they have the advantage of being about twice as efficient as internal combustion engines. In addition, fuel cells emit less pollutants because they directly convert the chemical energy generated by the combination of hydrogen and oxygen into electrical energy, making them environmentally friendly and reducing concerns about resource depletion due to increased energy consumption.

[0003] Depending on the type of electrolyte used, 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.

[0004] Although all of these fuel cells operate on the same 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 a high power density, and can be made compact. One of the most important factors in improving the performance of a polymer electrolyte fuel cell (PEMFC) is to maintain the moisture content by supplying a certain amount of moisture to the polymer electrolyte membrane (Polymer Electrolyte Membrane or Proton Exchange Membrane (PEM)) of the membrane electrode assembly (Membrane Electrode Assembly (MEA)). If the polymer electrolyte membrane dries out, the power generation efficiency drops sharply.

[0005] Methods for humidifying a polymer electrolyte membrane include 1) a bubbler humidification method in which an internal pressure vessel 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 layer 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 the 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.

[0006] The selectively permeable membrane used in the membrane humidification method is preferably a hollow fiber membrane with a large permeation area per unit volume when forming a module. That is, when a membrane humidifier is manufactured using a hollow fiber membrane, it is possible to highly integrate hollow fiber membranes with a large contact surface area, and it is possible to sufficiently humidify a fuel cell even with a small capacity, and it is possible to use low-cost materials. It is also possible to recover moisture and heat contained in off-gas discharged at high temperatures from a fuel cell and reuse them through a membrane humidifier.

[0007] FIG. 1 is an exploded oblique view showing a fuel cell membrane humidifier according to the prior art, FIG. 2 is a cross-sectional view taken along line A-A' in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B' in FIG. 1. As shown in Figures 1 to 3, a conventional fuel cell membrane humidifier 10 includes a humidification module 11 in which moisture exchange occurs between air supplied from the outside and exhaust gas discharged from a fuel cell stack (not shown), and caps 12 attached to both ends of the humidification module 11. One of the caps 12 supplies air supplied from the outside to the humidification module 11, and the other supplies air humidified by the humidification module 11 to the fuel cell stack.

[0008] The humidification module 11 includes a mid-case 11a having an off-gas inlet 11b and an off-gas outlet 11c, and at least one cartridge 20 disposed in the mid-case 11a. In the drawings, one cartridge is illustrated. The cartridge 20 includes an inner case 21, in which a plurality of hollow fiber membranes 22 and a potting portion 23 for fixing both ends of the bundle of hollow fiber membranes 22 are formed. The potting portion 23 is generally formed by hardening a liquid polymer such as a liquid polyurethane resin by a casting method.

[0009] A resin layer 11e is formed between the cartridge 20 and the mid-case 11a. The resin layer 11e fixes the cartridge 20 to the mid-case 11a and isolates the internal space of the cap 12 from the internal space of the mid-case 111. The internal space of the mid-case 11a is divided into a first space S1 and a second space S2 by partitions 11d. The inner case 21 has first mesh hole portions 24a arranged in a mesh shape for fluid communication with the first space S1 and second mesh hole portions 24b arranged in a mesh shape for fluid communication with the second space S2. The exhaust gas that flows into the first space S1 of the mid-case 11a through the exhaust gas inlet 11b flows into the inner case 21 through the first mesh hole portion 24a and comes into contact with the outer surface of the hollow fiber membrane 22. Next, the exhaust gas from which moisture has been removed flows into the second space S2 through the second mesh hole portion 24b, and is then discharged from the mid-case 11a through the exhaust gas outlet 11c. The cartridge 20 including such an inner case 21 has the advantage that it can be easily assembled to the mid-case 11a and can be easily replaced. In such a conventional cartridge 20, a constant flow rate always flows into the inside of the inner case 21 through the first mesh hole portion 24a regardless of the output amount of the fuel cell stack, which may cause excessive humidification in some cases. Summary of the Invention [Problem to be solved by the invention]

[0010] SUMMARY OF THE PRESENT EMBODIMENTS The present invention provides an automatic flow rate adjusting cartridge capable of automatically adjusting the flow rate of exhaust gas discharged from a fuel cell stack and flowing into the cartridge, and a fuel cell membrane humidifier including the same. [Means for solving the problem]

[0011] The automatic flow rate regulating cartridge according to an embodiment of the present invention includes: The fuel cell stack is provided with an inner case having a first mesh hole portion through which exhaust gas discharged from the fuel cell stack flows in and a second mesh hole portion through which the exhaust gas that flows in through the first mesh hole portion is discharged to the outside after exchanging moisture therewith, and a flow rate adjustment portion that is movably formed on one surface of the inner case and adjusts the flow rate of exhaust gas flowing into the first mesh hole portion depending on the exhaust gas flow rate.

[0012] In the automatic flow rate regulating cartridge according to an embodiment of the present invention, the flow rate regulating section may include a blocking member formed on one side of the inner case and blocking at least one mesh hole window constituting the first mesh hole section to prevent exhaust gas from flowing in, and an adjustment member formed on one side of the blocking member and moving the blocking member while compressing or expanding depending on the flow rate of the exhaust gas.

[0013] In the automatic flow rate regulating cartridge according to an embodiment of the present invention, the regulating member may include a pressure member formed in a shape inclined at a predetermined angle with one side of the blocking member, and an elastic member fixed to the pressure member and capable of being compressed or expanded depending on the exhaust gas flow rate. In addition, the fuel cell membrane humidifier according to the embodiment of the present invention includes: The fuel cell stack includes a mid-case, a cap fastened to the mid-case, and at least one cartridge disposed in the mid-case and housing a plurality of hollow fiber membranes. The cartridge includes an inner case having a first mesh hole portion through which exhaust gas discharged from a fuel cell stack flows and a second mesh hole portion through which the exhaust gas that flows in through the first mesh hole portion is discharged to the outside after moisture exchange, and a flow rate adjusting portion movably formed on one surface of the inner case and adjusting the flow rate of the exhaust gas flowing into the first mesh hole portion according to the flow rate of the exhaust gas.

[0014] In a fuel cell membrane humidifier according to an embodiment of the present invention, the flow rate control unit may include a blocking member formed on one side of the inner case and blocking at least one mesh hole window constituting the first mesh hole portion to prevent exhaust gas from flowing in, and an adjustment member formed on one side of the blocking member and moving the blocking member while compressing or expanding according to the flow rate of the exhaust gas. In the fuel cell membrane humidifier according to an embodiment of the present invention, the adjustment member may include a pressure member formed in a shape inclined at a predetermined angle with one side of the blocking member, and an elastic member fixed to the pressure member and capable of being compressed or expanded depending on the exhaust gas flow rate. In the fuel cell membrane humidifier according to an embodiment of the present invention, a partition wall may be provided to divide the internal space of the mid-case, and one end of the elastic member may be fixed to the partition wall and the other end may be fixed to the pressure member.

[0015] In a fuel cell membrane humidifier according to an embodiment of the present invention, a resin layer may be formed between the mid-case and the cartridge, and one end of the elastic member may be fixed to the resin layer and the other end may be fixed to the pressure member. In a fuel cell membrane humidifier according to an embodiment of the present invention, a gasket assembly may be formed between the mid-case and the cartridge, and one end of the elastic member may be fixed to the gasket assembly and the other end may be fixed to the pressure member. Further details, such as implementations of various aspects of the present invention, are included in the following detailed description. Effect of the Invention

[0016] According to the present invention, the flow rate of the exhaust gas discharged from the fuel cell stack and flowing into the cartridge can be automatically adjusted. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is an exploded perspective view of a fuel cell membrane humidifier according to the prior art; [Diagram 2] 2 is a cross-sectional view taken along line AA' in FIG. 1. [Diagram 3] 2 is a cross-sectional view taken along line BB' in FIG. 1. [Figure 4] 1 is an exploded perspective view showing a fuel cell membrane humidifier according to an embodiment of the present invention; [Diagram 5] 5 is a cross-sectional view taken along line AA' in FIG. 4. [Figure 6] 5 is a cross-sectional view taken along line BB' in FIG. 4. [Figure 7] 5 is a cross-sectional view taken along line BB' in FIG. 4. [Figure 8] FIG. 2 is a perspective view showing a flow rate adjusting section. [Figure 9] 11A to 11C are plan views for explaining the operation process of the flow rate adjusting unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention can be modified in various ways and can have various embodiments, and a specific embodiment will be illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to the specific embodiment, and it should be understood that the present invention includes all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention.

[0019] The terms used in the present invention are merely used to describe certain embodiments and are not intended to limit the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this specification, the terms "include" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to 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 according to an embodiment of the present invention will be described with reference to the drawings.

[0020] FIG. 4 is an exploded oblique view showing a fuel cell membrane humidifier according to one embodiment of the present invention, FIG. 5 is a cross-sectional view taken from line A-A' in FIG. 4, and FIGS. 6 and 7 are cross-sectional views taken from line B-B' in FIG. 4. As shown in FIGS. 4 to 7, a fuel cell membrane humidifier 100 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 is made of a material such as aluminum. The humidification module 110 exchanges moisture between air supplied from the outside and exhaust gas discharged from a fuel cell stack (not shown). Caps 120 are coupled to both ends of the humidification module 110. One of the caps 120 supplies air supplied from the outside to the humidification module 110, and the other supplies air humidified by the humidification module 110 to the fuel cell stack.

[0021] The humidification module 110 includes a mid-case 111 having an exhaust gas inlet 112 and an exhaust gas outlet 113, and at least one cartridge 200 disposed within the mid-case 111. The cartridge 200 is provided with a flow rate adjustment unit 300 that can automatically adjust the flow rate of exhaust gas discharged from the fuel cell stack and flowing into the cartridge. The flow rate adjustment unit 300 will be described later. The mid-case 111 and the cap 120 may be formed independently of each other from hard plastic or metal and may have a circular or polygonal widthwise cross section. A circular shape includes an oval shape, and a polygonal shape includes a polygonal shape with rounded corners. For example, the hard plastic may be polycarbonate, polyamide (PA), polyphthalamide (PPA), polypropylene (PP), etc. The internal space of the mid-case 111 may be divided into a first space S1 and a second space S2 by partitions 114. The cartridge 200 may include a plurality of hollow fiber membranes 220 and a potting portion 230 that fixes the hollow fiber membranes 220 to each other. Ends of the hollow fiber membranes 220 may be fixed to the potting portion 230.

[0022] The cartridge 200 may further include an inner case 210. The inner case 210 has an opening at each end, and the hollow fiber membrane 220 is placed therein. A potting part 230 to which the end of the hollow fiber membrane 220 is potted closes the opening of the inner case 210. The inner case 210 includes a first mesh hole portion 241 arranged in a mesh shape for fluid communication with the first space S1 and a second mesh hole portion 242 arranged in a mesh shape for fluid communication with the second space S2. The first mesh hole portion 241 and the second mesh hole portion 242 constitute a mesh hole portion 240. The exhaust gas that flows into the first space S1 of the mid-case 111 through the exhaust gas inlet 112 flows into the inner case 210 through the first mesh hole portion 241 and comes into contact with the outer surface of the hollow fiber membrane 220. Next, the exhaust gas from which moisture has been removed flows into the second space S2 through the second mesh hole portion 242, and is then discharged from the mid-case 111 through the exhaust gas outlet 113. At this time, the flow rate of the exhaust gas flowing into the inner case 210 through the first mesh hole portion 241 can be automatically adjusted by the flow rate adjustment portion 300.

[0023] The hollow fiber membrane 220 may include a polymer membrane formed of polysulfone resin, polyethersulfone resin, sulfonated polysulfone resin, polyvinylidene fluoride (PVDF) resin, polyacrylonitrile (PAN) resin, polyimide resin, polyamide-imide resin, polyester-imide resin, or a mixture of at least two of these, and the potting portion 113 may be formed by hardening a liquid resin such as liquid polyurethane resin by a casting method such as dip potting or centrifugal potting.

[0024] A resin layer 115 is formed between the cartridge 200 and the mid-case 111, and the resin layer 115 fixes the cartridge 200 to the mid-case 111 and isolates the internal space of the cap 120 from the internal space of the mid-case 111. Depending on the design, the resin layer 115 can be replaced with a gasket assembly that is hermetically coupled to each end of the humidification module 110 by mechanical assembly. 6, the cartridge 200 according to an embodiment of the present invention is provided with a flow rate adjusting unit 300 that automatically adjusts the flow rate of exhaust gas flowing into the inner case 210 through the first mesh hole portion 241. The flow rate adjusting unit 300 is formed movably on one surface of the inner case 210 according to the exhaust gas flow rate, and automatically adjusts the exhaust gas flow rate. 8, the flow rate control unit 300 includes a blocking member 310 and an adjusting member 320. The blocking member 310 is formed on one surface of the inner case 210 and blocks at least one mesh hole window W constituting the first mesh hole portion 241 to prevent exhaust gas from entering. The blocking member 310 may be formed in a shape corresponding to one surface of the inner case 210.

[0025] The adjustment member 320 is fixed to one surface of the blocking member 310. The adjustment member 320 moves the blocking member 310 while being compressed or expanded according to the flow rate of exhaust gas. Specifically, the adjustment member 320 includes a pressure member 321 and an elastic member 322. The pressure member 321 is formed in a shape inclined at a predetermined angle with one side (vertical side or horizontal side) of the blocking member 310, and is formed to extend from the upper surface of the blocking member 310 to a predetermined height. The elastic member 322 is formed of a material that can be compressed / expanded by pressure, and one end of the elastic member 322 is fixed to the partition wall 114 and the other end is fixed to the pressure member 321. Alternatively, one end of the elastic member 322 may be fixed to the resin layer 115 or a gasket assembly (not shown), and the other end may be fixed to the pressure member 321. The operation of the flow rate adjusting unit 300 configured in this manner will be described with reference to Fig. 9. Fig. 9 is a plan view showing the operation process of the flow rate adjusting unit 300.

[0026] The exhaust gas discharged from the fuel cell stack flows in through the exhaust gas inlet 112, flows through the first space S1 inside the mid-case 111, and flows into the inner case 210 in which the hollow fiber membrane is disposed through the mesh hole window W forming the first mesh hole portion 241. At this time, at least a part of the exhaust gas flow F collides with the pressurizing member 321 formed on the upper surface of the blocking member 310, and presses the pressurizing member 321. The elastic member 322 is compressed by the pressurization, and thus the pressurizing member 321 moves in the direction of the partition wall 114. At this time, the blocking member 310 fixedly formed with the pressurizing member 321 also moves together with the pressing member 321. As the blocking member 310 moves, more mesh hole windows W forming the first mesh hole portion 241 are opened. (See FIG. 6 and FIG. 7)

[0027] When the flow rate of exhaust gas discharged from the fuel cell stack is high, the exhaust gas flow F strongly pressurizes the pressurizing member 321 to open a relatively large number of mesh hole windows W, and when the flow rate is low, the exhaust gas flow F weakly pressurizes the pressurizing member 321 to open a relatively small number of mesh hole windows W. Therefore, the flow rate adjusting unit 300 can automatically adjust the flow rate of exhaust gas flowing into the inner case 210 according to the exhaust gas flow rate. Although one embodiment of the present invention has been described above, a person having ordinary knowledge in the art would be able to modify and change the present invention in various ways by adding, changing, deleting, or adding components without departing from the concept of the present invention described in the claims, and this would also be considered to be within the scope of the claims of the present invention. [Explanation of symbols]

[0028] 100:Fuel cell membrane humidifier 110: Humidification module 111: Mid-case 112: Exhaust gas inlet 113: Exhaust gas outlet 114: Partition wall 115: Resin layer 200: Cartridge 210: Inner case 220: Hollow fiber membrane 230: Potting section 240: Mesh hole section 300: flow rate adjusting section 310: blocking member 320: Adjustment member 321: Pressurizing member 322: Elastic member

Claims

1. an inner case having a first mesh hole portion through which exhaust gas discharged from a fuel cell stack flows and a second mesh hole portion through which the exhaust gas that flows in through the first mesh hole portion exchanges moisture and is then discharged to the outside; a flow rate adjusting section that is movably formed on one surface of the inner case and adjusts the flow rate of exhaust gas flowing into the first mesh hole section according to the exhaust gas flow rate, The flow rate adjusting unit is a blocking member formed on one surface of the inner case and blocking at least one mesh hole window constituting the first mesh hole portion to prevent exhaust gas from entering the mesh hole window; an adjustment member formed on one surface of the blocking member and compressing or expanding the blocking member according to the flow rate of the exhaust gas, The adjustment member is a pressure member formed in a shape inclined at a predetermined angle with respect to one side of the blocking member; an elastic member fixed to the pressurizing member and capable of being compressed or expanded depending on the flow rate of exhaust gas; An automatic flow adjustment cartridge comprising:

2. Mid-case and a cap fastened to the mid-case; At least one cartridge disposed within the mid-case and housing a plurality of hollow fiber membranes; Equipped with The cartridge comprises: an inner case having a first mesh hole portion through which exhaust gas discharged from a fuel cell stack flows and a second mesh hole portion through which the exhaust gas that flows in through the first mesh hole portion exchanges moisture and is then discharged to the outside; a flow rate adjusting section that is movably formed on one surface of the inner case and adjusts the flow rate of exhaust gas flowing into the first mesh hole section according to the exhaust gas flow rate, The flow rate adjusting unit is a blocking member formed on one surface of the inner case and blocking at least one mesh hole window constituting the first mesh hole portion to prevent exhaust gas from entering the mesh hole window; an adjustment member formed on one surface of the blocking member and compressing or expanding the blocking member according to the flow rate of the exhaust gas, The adjustment member is a pressure member formed in a shape inclined at a predetermined angle with respect to one side of the blocking member; an elastic member fixed to the pressurizing member and capable of being compressed or expanded depending on the flow rate of exhaust gas; A fuel cell membrane humidifier comprising:

3. A partition wall is provided to divide an internal space of the mid-case, 3. The fuel cell membrane humidifier according to claim 2, wherein one end of the elastic member is fixed to the partition wall, and the other end is fixed to the pressure member.

4. a resin layer formed between the mid-case and the cartridge; 3. The fuel cell membrane humidifier according to claim 2, wherein one end of the elastic member is fixed to the resin layer, and the other end is fixed to the pressure member.

5. a gasket assembly formed between the mid-case and the cartridge; 3. The fuel cell membrane humidifier according to claim 2, wherein one end of the elastic member is fixed to the gasket assembly and the other end is fixed to the pressure member.

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