Fuel cell membrane humidifier

Abstract

The present invention relates to a fuel cell membrane humidifier that can selectively supply exhaust gas discharged from a fuel cell stack to each part of a hollow fiber membrane module to improve humidification efficiency, The fuel cell membrane humidifier according to an embodiment of the present invention comprises: The system comprises: a hollow fiber membrane module containing a plurality of hollow fiber membranes that exchange moisture between dry gas supplied from a blower and exhaust gas flowing in from a fuel cell stack to humidify the dry gas; a humidification module that contains the hollow fiber membrane module and has a first exhaust gas inlet through which exhaust gas flows in from the fuel cell stack and a first exhaust gas outlet through which the moisture-exchanged exhaust gas is discharged; a submodule that divides the hollow fiber membrane module into a central portion and a peripheral portion and has a second exhaust gas inlet for receiving the exhaust gas discharged from the fuel cell stack and a second exhaust gas outlet through which the moisture-exchanged exhaust gas is discharged; and an active flow control unit that is formed between the fuel cell stack and the humidification module and automatically controls the exhaust gas discharged from the fuel cell stack to be supplied to at least one selected from the first and second exhaust gas inlets.

Description

[Technical field]

[0001] The present invention relates to a fuel cell membrane humidifier, and more specifically, to a fuel cell membrane humidifier that can improve humidification efficiency by selectively supplying exhaust gas discharged from a fuel cell stack to each part of a hollow fiber membrane module. [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. 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. 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.

[0003] 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. 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 humidifier to be made lighter and smaller. 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 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 temperature from a fuel cell and reuse them through a humidifier.

[0004] FIG. 1 is a diagram showing a fuel cell membrane humidifier according to the prior art. As shown in FIG. 1, a conventional fuel cell membrane humidifier 10 includes a humidification module 11 in which moisture exchange occurs between dry gas supplied from a blower (B) and moist air (exhaust gas) discharged from a fuel cell stack S, and gaps (12: 12a, 12b) coupled to both ends of the humidification module 11. One of the gaps 12, 12a, is formed with a dry gas inlet 13 for supplying dry gas supplied from a blower B to the humidification module 11, and the other gap, 12b, is formed with a dry gas outlet 14 for supplying air humidified by the humidification module 11 to the fuel cell stack S. The humidification module 110 includes a mid-case 11a having an off-gas inlet 11aa and an off-gas outlet 111ab, and a plurality of hollow fiber membranes 11b in the mid-case 11a. Both ends of the bundle of hollow fiber membranes 11b are fixed to a potting portion 11c. The potting portion 11c is generally formed by hardening a liquid polymer such as liquid polyurethane resin by a casting method. Dry gas supplied from blower B flows along the hollow of hollow fiber membrane 11b. The exhaust gas that flows into mid-case 11a through exhaust gas inlet 11aa comes into contact with the outer surface of hollow fiber membrane 11b, and is then discharged from mid-case 11a through exhaust gas outlet 11ab. When the exhaust gas comes into contact with the outer surface of hollow fiber membrane 11b, moisture contained in the exhaust gas permeates hollow fiber membrane 11b, thereby humidifying the dry gas that has been flowing along the hollow of hollow fiber membrane 11b.

[0005] Meanwhile, as shown in FIG. 2, according to the conventional technology of FIG. 1, the dry gas flowing from the blower B into the humidification module 11 mainly flows along the inside of the hollow fiber membrane arranged in the central part of the hollow fiber membrane 11b (see H1 in FIG. 2), and the exhaust gas flowing from the fuel cell stack S into the mid-case 11a through the exhaust gas inlet 11aa mainly flows along the outside of the hollow fiber membrane arranged in the peripheral part of the hollow fiber membrane 11b (see H2 in FIG. 2). This reduces contact between the dry gas and the exhaust gas, resulting in a problem of reduced humidification efficiency. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to provide a fuel cell membrane humidifier that can improve humidification efficiency by selectively supplying exhaust gas discharged from a fuel cell stack to each part of a hollow fiber membrane module. [Means for solving the problem]

[0007] The fuel cell membrane humidifier according to an embodiment of the present invention comprises: The system comprises: a hollow fiber membrane module containing a plurality of hollow fiber membranes that exchange moisture between dry gas supplied from a blower and exhaust gas flowing in from a fuel cell stack to humidify the dry gas; a humidification module that contains the hollow fiber membrane module and has a first exhaust gas inlet through which exhaust gas flows in from the fuel cell stack and a first exhaust gas outlet through which the moisture-exchanged exhaust gas is discharged; a submodule that divides the hollow fiber membrane module into a central portion and a peripheral portion and has a second exhaust gas inlet for receiving the exhaust gas discharged from the fuel cell stack and a second exhaust gas outlet through which the moisture-exchanged exhaust gas is discharged; and an active flow control unit that is formed between the fuel cell stack and the humidification module and automatically controls the exhaust gas discharged from the fuel cell stack to be supplied to at least one selected from the first and second exhaust gas inlets. In the fuel cell membrane humidifier according to an embodiment of the present invention, the active flow control unit may be formed of a bimetal manufactured by stacking two or more metal plates having different thermal expansion coefficients into one rod shape. In a fuel cell membrane humidifier according to an embodiment of the present invention, the active flow control unit can automatically control the supply of exhaust gas to at least one selected from the first and second exhaust gas inlets depending on the temperature of the exhaust gas discharged from the fuel cell stack.

[0008] In a fuel cell membrane humidifier according to an embodiment of the present invention, the active flow control unit can automatically control exhaust gas to be supplied to at least one selected from the first and second exhaust gas inlets depending on the output status of the fuel cell stack. The fuel cell membrane humidifier according to the embodiment of the present invention may further include a turbulence generating unit that changes the flow direction of the dry gas flowing from the blower so that the dry gas can be evenly distributed to the hollow fiber membrane. In the fuel cell membrane humidifier according to an embodiment of the present invention, a cap may be provided that is fastened to both ends of the humidification module, and the turbulence generating portion may be formed on an inner wall of a dry gas inlet formed in the cap. In the fuel cell membrane humidifier according to an embodiment of the present invention, the turbulence generating unit may include a plurality of protrusions protruding from an inner wall of the dry gas inlet, and the plurality of protrusions may be spaced apart in a zigzag shape. In the fuel cell membrane humidifier according to the embodiment of the present invention, the turbulence generating unit is The drying gas inlet may further include a through hole formed in a direction parallel to a flow direction of the drying gas in the drying gas inlet. Further details of implementations of various aspects of the present invention are included in the following detailed description. Effect of the Invention

[0009] According to an embodiment of the present invention, exhaust gas discharged from a fuel cell stack can be selectively supplied to each part of a hollow fiber membrane module, thereby improving humidification efficiency. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a fuel cell membrane humidifier according to the prior art; [Diagram 2] FIG. 1 is a cross-sectional view for explaining a problem of a fuel cell membrane humidifier according to the prior art. [Diagram 3] 1 is a perspective view showing a fuel cell membrane humidifier according to an embodiment of the present invention; [Figure 4] FIG. 2 is a diagram showing an active flow control element of a fuel cell membrane humidifier according to an embodiment of the present invention. [Diagram 5] 5 is a diagram showing an operating state of the active flow control unit of FIG. 4. [Figure 6] 5 is a diagram showing an operating state of the active flow control unit of FIG. 4. [Figure 7] 1 is a cross-sectional view showing an operation state of a fuel cell membrane humidifier according to an embodiment of the present invention; [Figure 8] 1 is a cross-sectional view showing an operation state of a fuel cell membrane humidifier according to an embodiment of the present invention; [Figure 9] 1 is a cross-sectional view showing an operation state of a fuel cell membrane humidifier according to an embodiment of the present invention; [Figure 10] 2 is an enlarged view of a turbulence generating unit, which is one component of a fuel cell membrane humidifier according to an embodiment of the present invention; FIG. [Figure 11] 11 is a diagram showing an operating state of the turbulence generating part of FIG. 10. FIG. [Figure 12] FIG. 13 is an enlarged view of an application example of a turbulence generating portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 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. 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. 3 is a perspective view showing a fuel cell membrane humidifier according to an embodiment of the present invention. As shown in FIG. 3, the fuel cell membrane humidifier according to an embodiment of the present invention includes a humidification module 110 that humidifies dry gas supplied from a blower B with moisture in exhaust gas discharged from a fuel cell stack S. Both ends of the humidification module 110 are respectively coupled to caps (120: 120a, 120b). The humidification module 110 and the cap 120 may be formed separately or integrally. One of the gaps 120, 120a, is formed with a dry gas inlet 130 for supplying dry gas supplied from the blower B to the humidification module 110, and the other gap, 120b, is formed with a dry gas outlet 140 for supplying air humidified by the humidification module 110 to the fuel cell stack S.

[0012] The humidification module 110 is a device in which moisture exchange occurs between the dry gas supplied from the blower B and the exhaust gas, and includes a mid-case 111 having a first off-gas inlet 111a and a second off-gas outlet 111b, and a hollow fiber membrane module 150 disposed within the mid-case 111 and housing a plurality of hollow fiber membranes F. Both ends of the hollow fiber membrane F are fixed to potting portions (not shown). A plurality of exhaust gas inlet holes 151 are formed penetrating the hollow fiber membrane module 150, and a plurality of hollow fiber membranes F contained therein are separated and partitioned into a central portion H1 and a peripheral portion H2 by the submodule 160. The exhaust gas inlet holes 151 guide the exhaust gas supplied into the humidification module 110 to flow into the inside of the hollow fiber membrane module 150. The hollow fiber membrane module 150 may be divided into a central portion H1 and a peripheral portion H2 by the submodule 160. The submodule 160 may be formed in a hollow pipe shape. The submodule 160 may be formed in a coaxial structure within the hollow fiber membrane module 150. A second exhaust gas inlet 112a for introducing exhaust gas discharged from the fuel cell stack S is formed on one side of the submodule 160, and a second exhaust gas outlet 112b for discharging exhaust gas that has supplied moisture to the inside of the hollow fiber membrane F is formed through the other side. The second exhaust gas inlet 112a and the second exhaust gas outlet 112b are formed by penetrating the mid-case 111 and the hollow fiber membrane module 150.

[0013] The exhaust gas supplied to the first exhaust gas inlet 111a of the humidification module 110 flows into the hollow fiber membrane module 150 through the exhaust gas inlet hole 151 and is supplied only to the hollow fiber membranes arranged in the peripheral portion H2 of the hollow fiber membrane module 150. The second exhaust gas inlet 112a supplies the exhaust gas discharged from the fuel cell stack S to the inside of the submodule 160, i.e., to the central part H1 of the hollow fiber membrane module 150, and the second exhaust gas outlet 112b discharges to the outside the exhaust gas that has exchanged moisture with the dry gas in the hollow fiber membrane in the central part H1 of the hollow fiber membrane module 150. The exhaust gas supplied to the second exhaust gas inlet 112a is supplied only to the hollow fiber membrane arranged in the central part H1 of the hollow fiber membrane module 150. The mid-case 111 and the caps (120: 120a, 120b) may each be independently made of 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 hollow fiber membrane F may include a polymer membrane formed of 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 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. The dry gas supplied from the blower B flows along the hollow of the hollow fiber membrane F. The exhaust gas that flows into the hollow fiber membrane module 150 through the first and second exhaust gas inlets 111a, 112a comes into contact with the outer surface of the hollow fiber membrane F, and is then discharged to the outside through the first and second exhaust gas outlets 111b, 112b. When the exhaust gas comes into contact with the outer surface of the hollow fiber membrane F, the moisture contained in the exhaust gas permeates the hollow fiber membrane F, thereby humidifying the dry gas that has been flowing along the hollow of the hollow fiber membrane F.

[0014] An active flow control unit 200 is formed between the fuel cell stack S and the humidification module 110. The active flow control unit 200 supplies exhaust gas to at least one selected from the first and second exhaust gas inlets 111a and 112a depending on the temperature of the exhaust gas discharged from the fuel cell stack S. The active flow control unit 200 controls the flow direction of the exhaust gas discharged from the fuel cell stack S and flowing into the humidification module 110 to increase the utilization area of ​​the hollow fiber membrane module 150 and to actively adjust the amount of humidification depending on the output status of the fuel cell stack S. This will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram showing an active flow control device of a fuel cell membrane humidifier according to one embodiment of the present invention, and FIG. 5 and FIG. 6 are diagrams showing the operating state of the active flow control device of FIG. 4. 4, the active flow controller 200 is formed between the fuel cell stack S and the first and second exhaust gas inlets 111a, 112a. The fuel cell stack S and the active flow controller 200 are connected to an exhaust flow path L0, the active flow controller 200 and the first exhaust gas inlet 111a are connected to a first flow path L1, and the active flow controller 200 and the second exhaust gas inlet 112a are connected to a second flow path L2. The exhaust gas flowing from the fuel cell stack S through the exhaust flow path L0 has its flow direction controlled by an active flow control device 200 formed at the end of the exhaust flow path L0, and flows to the first and second exhaust gas inlet ports 111a, 112a through at least a portion of the first flow path L1 and the second flow path L2. The active flow control device 200 adjusts the flow direction of the exhaust gas flowing into the first exhaust gas inlet 111a and the second exhaust gas inlet 112a according to the output state of the fuel cell stack. The active flow control device 200 actively adjusts the flow direction of the exhaust gas according to the temperature change of the exhaust gas caused by high or low output of the fuel cell stack.

[0015] For this, the active flow control part 200 may be formed of a bimetal that is manufactured by stacking two or more metal plates having different thermal expansion coefficients into one rod shape. When the output of the fuel cell stack S is low, the amount of humidification in the humidification module 110 is relatively small, and when the output of the fuel cell stack S is high, the amount of humidification in the humidification module 110 is relatively large. In addition, when the output of the fuel cell stack S is low, the exhaust gas supplied from the fuel cell stack S to the humidification module 110 is relatively low temperature, and when the output of the fuel cell stack S is high, the exhaust gas supplied from the fuel cell stack S to the humidification module 110 is relatively high temperature. Usually, there is a difference of about 30°C between the exhaust gas temperature at low output and the exhaust gas temperature at high output. Therefore, the exhaust gas temperature differs depending on the output of the fuel cell stack S, and the active flow control unit 200 including a bimetal can bend in one direction depending on the exhaust gas temperature to adjust the opening degree of the flow path. The active flow control unit 200 uses a bimetal to automatically adjust the opening degree of the first flow path L1 and the second flow path L2 so that when the output is low, the amount of humidification in the humidification module 110 is small, and when the output is high, the amount of humidification in the humidification module 110 is large. Meanwhile, the amount of humidification can be determined by the number N1 of hollow fiber membranes F accommodated in the central portion H1 and the number N2 of hollow fiber membranes F accommodated in the peripheral portion H2. For example, if N1 is greater than N2, the bimetal of the active flow control portion 200 can be deformed so that exhaust gas is supplied to the central portion H1 at high output, and the bimetal can be deformed so that exhaust gas is supplied to the peripheral portion H2 at low output. That is, the bimetal of the active flow control portion 200 can be deformed so that exhaust gas is supplied to the second exhaust gas inlet 112a at high output as shown in FIG. 6, and the bimetal can be deformed so that exhaust gas is supplied to the first exhaust gas inlet 111a at low output as shown in FIG. In this case, the active flow control device 200 can be constructed such that the metal plate (210, first flow path side metal plate) on the first exhaust gas inlet 111a side is made of a metal with a small thermal expansion coefficient, and the metal plate (220, second flow path side metal plate) on the second exhaust gas inlet 112a side is made of a metal with a large thermal expansion coefficient.

[0016] Such an active flow control device 200 does not have a valve for controlling the exhaust gas flow direction, a sensor for sensing the exhaust gas flow rate, or a control device for controlling the operation of the valve, but can actively adjust the flow rate by adjusting the exhaust gas to flow evenly to the first exhaust gas inlet 111a and the second exhaust gas inlet 112a, or to flow more to one of the first exhaust gas inlet 111a and the second exhaust gas inlet 112a, or to prevent the exhaust gas from flowing to one of the first exhaust gas inlet 111a and the second exhaust gas inlet 112a, depending on the output state of the fuel cell stack. Through the flow control of the active flow control unit 200, the exhaust gas discharged from the fuel cell stack S can be supplied and flow only to the peripheral part H2 of the hollow fiber membrane module 150 as shown in FIG. 7, or only to the central part H1 of the hollow fiber membrane module 150 as shown in FIG. 8, or simultaneously to the central part H1 and peripheral part H2 of the hollow fiber membrane module 150 as shown in FIG. 9. Through the operation of the active flow control unit 200, the utilization area of ​​the hollow fiber membrane module 150 can be changed and adjusted, thereby improving the humidification efficiency of the membrane humidifier. In addition, the amount of humidification can be adjusted according to the state of the fuel cell stack S by changing and adjusting the utilization area of ​​the hollow fiber membrane module 150 through the operation of the active flow control unit 200. According to the embodiment of the present invention, the degree of humidification of the dry gas supplied to the fuel cell stack is adjusted according to the state of the stack, thereby enabling appropriate air humidification according to the operating conditions of the stack.

[0017] 1 and 2, the dry gas flowing from the blower B into the humidification module 11 mainly flows along the inside of the hollow fiber membranes arranged in the center part (see H1 in FIG. 2) of the hollow fiber membranes 11b. Therefore, even if the active flow control unit 200 adjusts the flow direction of the exhaust gas flowing into the first exhaust gas inlet 111a and the second exhaust gas inlet 112a according to the output state of the fuel cell stack S, if the dry gas cannot be distributed evenly, the humidification degree of the dry gas cannot be effectively adjusted. Accordingly, in the present invention, as shown in FIG. 10, a turbulent flow generating unit 131 for enabling the dry gas to be uniformly distributed to the hollow fiber membranes F may be further provided on the dry gas inlet 130 side. The turbulence generating part 131 is formed on the inner wall of the dry gas inlet 130 to change the flow direction of the dry gas so that the dry gas is evenly distributed to the hollow fiber membranes F. The dry gas inlet 130 may be a part of the cap 120a formed and connected to the blower B, or may be a separate pipe connecting the blower B and the cap 120a.

[0018] The turbulence generating part 131 may be formed on an inner wall of the dry gas inlet 130. The turbulence generating part 131 may be formed as a plurality of protrusions protruding from the inner wall of the dry gas inlet 130. The plurality of protrusions may be spaced apart in a zigzag shape. In the drawings, the shape of the protrusions is illustrated as a sphere, but is not particularly limited. Alternatively, a fixing groove (not shown) may be formed on the inner wall of the dry gas inlet 130, and the turbulence generating part 131 may be formed in a spherical or protruding shape and inserted and fixed in the fixing groove (not shown). FIG. 11 is a diagram showing a flow state of the drying gas by the turbulence generating unit 131 of FIG. A part of the dry gas flowing from the blower B into the dry gas inlet 130 collides with the turbulent flow generating part 131 having a sphere or a protrusion shape formed on the inner wall of the dry gas inlet 130, and changes its flow direction, thereby affecting the flow direction of the surrounding dry gas, so that an overall turbulent flow is formed. The dry gas turbulentized by the turbulent flow generating part 131 diffuses from the end of the dry gas inlet 130 and flows into not only the hollow fiber membranes disposed near the dry gas inlet 130 but also the hollow fiber membranes disposed far from the dry gas inlet 130. As a result, most of the dry gas flowing into the dry gas inlet 130 can be evenly distributed to the hollow fiber membranes F in the humidification module 110. Meanwhile, the turbulent flow generating unit 131 can distribute the dry gas evenly to the hollow fiber membrane F, but at the same time, it generates a pressure loss of the dry gas as the dry gas collides with the turbulent flow generating unit 131. As a result, the flow speed of the dry gas is reduced, and the humidification efficiency may be reduced. 12, in order to reduce the decrease in humidification efficiency due to such pressure loss, a through-hole 131a may be further formed in the turbulence generating part 131. The through-hole 131a is formed penetrating at least a part of the turbulence generating part 131. The through-hole 131a may be formed in a direction parallel to the flow direction of the dry gas in the dry gas inlet 130.

[0019] According to this, part of the dry gas flowing into the dry gas inlet 130 collides with the turbulent flow generating part 131 and changes its flow direction, but the remaining part proceeds straight through the through-hole 131a. The dry gas whose flow direction has been changed contributes to the formation of a turbulent flow, and the part of the dry gas that proceeds straight through the through-hole 131a continues to flow without any pressure loss. Therefore, overall, the dry gas is mixed into turbulent flow (dry gas flow that has lost its straight-line flow) and direct flow (dry gas flow that maintains its straight-line flow), so that the dry gas is distributed relatively evenly to the hollow fiber membrane F and the pressure loss of the dry gas can be reduced. 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]

[0020] 110: humidification module 120a, 120b: caps 111a: first exhaust gas inlet 111b: first exhaust gas outlet 112a: second exhaust gas inlet 112b: second exhaust gas outlet 130: Drying gas inlet 131: Turbulence generating section 140: Drying gas outlet 150: Hollow fiber membrane module 160: Submodule 200: Active flow control unit H1: Center H2: Periphery F: Hollow fiber membrane B: Blower S: Fuel cell stack

Claims

1. a hollow fiber membrane module containing a plurality of hollow fiber membranes that humidify a dry gas supplied from a blower by moisture exchange between the dry gas and an exhaust gas flowing in from a fuel cell stack; a humidification module including a first exhaust gas inlet through which exhaust gas flows from the fuel cell stack and a first exhaust gas outlet through which moisture-exchanged exhaust gas is discharged, the humidification module housing the hollow fiber membrane module therein; a submodule that divides the hollow fiber membrane module into a central portion and a peripheral portion, the submodule having a second exhaust gas inlet for receiving exhaust gas discharged from the fuel cell stack and a second exhaust gas outlet for discharging exhaust gas that has been subjected to moisture exchange; an active flow control unit formed between the fuel cell stack and the humidification module, and configured to automatically control the exhaust gas discharged from the fuel cell stack so that the exhaust gas can be supplied to at least one selected from the first and second exhaust gas inlets; a turbulence generating unit for changing a flow direction of the dry gas flowing from the blower so that the dry gas can be uniformly distributed to the hollow fiber membrane; a cap that is fastened to both ends of the humidification module; The exhaust gas supplied to the first exhaust gas inlet is supplied to the hollow fiber membranes arranged in the peripheral portion of the hollow fiber membrane module, and the exhaust gas supplied to the second exhaust gas inlet is supplied to the hollow fiber membranes arranged in the central portion of the hollow fiber membrane module, The turbulence generating portion is formed on an inner wall of a dry gas inlet formed in the cap, The turbulence generating portion includes a plurality of protrusions formed on an inner wall of the drying gas inlet, A through hole is formed through at least a part of the turbulent flow generating portion, The through-hole is formed in a direction parallel to the flow direction of the dry gas in the dry gas inlet. Fuel cell membrane humidifier.

2. The active flow control section includes:

2. The fuel cell membrane humidifier according to claim 1, which is formed of a bimetal made by stacking two or more metal plates having different thermal expansion coefficients into one rod shape.

3. The active flow control section includes: The fuel cell membrane humidifier of claim 1, which automatically controls the supply of exhaust gas to at least one of the first and second exhaust gas inlets depending on the temperature of the exhaust gas discharged from the fuel cell stack.

4. The active flow control section includes:

2. The fuel cell membrane humidifier of claim 1, which is automatically controlled so that exhaust gas can be supplied to at least one selected from the first and second exhaust gas inlets depending on the output status of the fuel cell stack.

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