Membrane humidifier for fuel cells

Abstract

The present invention relates to a membrane humidifier for a fuel cell, comprising: a housing having an inlet on one side through which moist gas is introduced and an outlet on the other side through which the moist gas introduced through the inlet is discharged; a first cap coupled to one side of the housing through which external air is introduced; a plurality of hollow fiber membranes installed inside the housing through which the external air introduced through the first cap flows and through which the moist gas comes into contact with the outer surface to humidify the external air; an injection unit that uses air pressure to direct the moist gas introduced through the inlet toward the outlet under predetermined conditions; and a second cap coupled to the other side of the housing through which the external air flows along the hollow fiber membranes and is humidified before being discharged.

Description

[Technical Field]

[0001] The present invention relates to a membrane humidifier for a fuel cell, and more particularly to a membrane humidifier for a fuel cell that prevents excessive humidified air from flowing into a stack during the initial operation or low output section. [Background technology]

[0002] Fuel cells generate electrical energy using chemical energy generated by the combination of hydrogen and oxygen. Fuel cells have recently been the subject of active research as an environmentally friendly energy source that emits fewer pollutants. Fuel cells are broadly classified into polymer electrolyte membrane fuel cells (PEMFC), phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), solid oxide fuel cells (SOFC), and alkaline fuel cells (AFC) depending on the type of electrolyte used. Each of these fuel cells operates on the same fundamental principle, but differs 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 membrane fuel cells (PEMFCs) is to maintain the functionality 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 (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 a pressure-resistant 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 membrane humidification method, in which moisture is supplied to the gas flow bed using a polymer separation membrane. Among these, the membrane humidification method, in which moisture is supplied to the gas flow bed by using a membrane that selectively transmits only the water vapor contained in the exhaust gas, thereby humidifying the polymer electrolyte membrane, is advantageous because it allows for lighter and more compact humidifiers.

[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. When manufacturing a humidifier using hollow fiber membranes, it is possible to highly integrate hollow fiber membranes with a large contact surface area, and they have the advantages of being able to sufficiently humidify a fuel cell even with a small capacity, being relatively inexpensive, and being able to recover moisture and heat contained in the off-gas discharged at high temperatures from the fuel cell and reuse it in the humidifier. 1 is a schematic exploded perspective view of a conventional membrane humidifier for a fuel cell. Referring to FIG. 1, the conventional membrane humidifier includes a humidification module 110 in which moisture exchange occurs between air supplied from the outside and exhaust gas discharged from a fuel cell stack (not shown), and first and second caps 120 and 130 coupled to both ends of the humidification module 110, respectively. External air flows in through an inlet 121 of the first cap 120 and is delivered to the humidification module 110, and the air humidified by the humidification module 110 is delivered to the fuel cell stack through an outlet 131 of the second cap 130. The humidification module 110 includes a housing 111 having a wet gas inlet 111a through which wet exhaust gas flows in and a wet gas outlet 111b through which the exhaust gas is discharged, and a cartridge 100 disposed within the housing 111. The cartridge 100 is fastened to a fastening portion 112 of the housing 111. A plurality of cartridges 100 may be fastened to the fastening portion 112. A hollow fiber membrane is filled inside the cartridge 100, and both ends of the hollow fiber membrane are potted and fixed to both ends of the cartridge 100. The hollow fiber membrane may be potted by hardening a liquid polymer such as a liquid polyurethane resin. Air supplied from the outside flows into first cap 120 and flows along the hollow fiber membranes. Exhaust gas flowing into housing 111 through wet exhaust gas inlet 111a comes into contact with the outer surface of the hollow fiber membranes and then flows out of housing 111 through wet exhaust gas outlet 111b. When the exhaust gas comes into contact with the outer surface of the hollow fiber membranes, moisture contained in the exhaust gas permeates the hollow fiber membranes, humidifying the air flowing along the hollow fiber membranes. In this manner, the wet gas flowing into the wet gas inlet 111a is humidified by contacting the outer surface of the hollow fiber membrane disposed inside the cartridge 100. A plurality of cartridges 100 are disposed adjacent to each other, and the wet gas flows between the cartridges 100 and then flows into the interior through windows formed in the cartridges 100. As described above, the membrane humidifier humidifies the external air using the humidified gas discharged from the stack and then supplies it to the stack. However, if the external air is excessively humidified, the over-humidified air may flow into the stack, resulting in a decrease in the power generation efficiency of the fuel cell. This over-humidification caused by the humidified gas is particularly problematic during the initial operation or when the engine is at low power output. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention has been devised to improve the above-mentioned problems, and is to provide a membrane humidifier for a fuel cell that prevents excessive humidified air from flowing into the stack during the initial operation or low output section. [Means for solving the problem]

[0005] The membrane humidifier for a fuel cell according to the present invention comprises: a housing having an inlet formed on one side thereof for introducing wet gas and an outlet formed on the other side thereof for discharging the wet gas introduced through the inlet; a first cap coupled to one side of the housing and for receiving the outside air; a plurality of hollow fiber membranes disposed inside the housing through which the outside air introduced through the first cap flows and through which the wet gas comes into contact with the outer surface thereof to humidify the outside air; an injection unit that uses air pressure to direct the wet gas introduced through the inlet toward the outlet under predetermined conditions; and a second cap coupled to the other side of the housing through which the outside air flows along the hollow fiber membranes and is humidified before being discharged. In addition, the plurality of hollow fiber membranes may be provided inside a cartridge that is detachably coupled to the housing, the housing may be provided with a fastening portion for fastening the cartridge, the fastening portion may be provided with a bypass hole that allows the wet gas flowing in through the inlet to flow toward the outlet, and the spray portion may spray air pressure toward the bypass hole. In addition, the air pressure of the injection unit may be branched and provided before external air is introduced through the first cap. The front end of the first cap may include a branch passage that branches the external air toward the injection portion; and a flow rate control valve that is provided in the branch passage and adjusts the flow rate of the branched external air. The injection unit may include a plurality of injection holes for supplying the air pressure, and the injection holes may be spaced apart from each other in a horizontal direction. Also, the injection holes may be aligned to face the bypass holes. The liquid may also include a controller for adjusting the flow rate supplied by the jetting unit. In addition, the control unit may 1) provide air pressure through the injection unit until 1 minute after startup, or 2) provide air pressure through the injection unit until the flow rate of the wet gas flowing into the inlet reaches 2000 slpm after startup. Additionally, the flow rate provided by the injectors may be gradually reduced until a predetermined time after the vehicle is started. Also, the flow rate provided by the injector may be gradually reduced after the vehicle is started until the flow rate of the wet gas flowing into the inlet reaches a predetermined set value. [Effects of the Invention]

[0006] The membrane humidifier for a fuel cell according to the present invention provides an effect of preventing over-humidification by bypassing the wet gas flowing into the housing during the initial operation or low output section before it flows into the hollow fiber membrane. In addition, since the wet gas is pushed toward the bypass hole by the jetting portion using air pressure and discharged, it is possible to provide an effect of bypassing the wet gas with a relatively simple structure. In addition, the air pressure of the injection section is generated by branching the external air flowing into the housing from the outside, thereby preventing excessive external air from flowing into the stack during the initial operation or low output section. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an exploded perspective view of a conventional membrane humidifier. [Figure 2] FIG. 1 is a side view of a membrane humidifier according to one embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2. [Figure 5] FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along the line CC in FIG. 5. [Figure 7] FIG. [Figure 8] FIG. 1 is a block diagram according to one embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view of a membrane humidifier according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] Various embodiments of the present invention will now be described with reference to the accompanying drawings. While various modifications and variations of the present invention are possible, specific embodiments are illustrated in the drawings and described in detail below. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention encompasses all modifications and / or equivalents or alternatives falling within the spirit and technical scope of the present invention. In describing the drawings, similar reference numerals are used to refer to similar components. When used in various embodiments of the present invention, the terms "comprise" or "may comprise" indicate the presence of a disclosed feature, operation, or component, etc., and do not limit the presence of one or more additional features, operations, or components, etc. Furthermore, in various embodiments of the present invention, the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood as not precluding the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof. When a component is said to be "coupled" to another component, it should be understood that the component may be "directly coupled" to the other component, but there may be other components between the component and the other component. On the other hand, when a component is said to be "directly coupled" or "directly connected" to another component, it should be understood that there are no other components between the component and the other component. The terms used in the various embodiments of the present invention are merely used to describe particular embodiments and are not intended to limit the various embodiments of the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this invention belong. Terms defined in commonly used dictionaries should be construed to have a meaning consistent with the contextual meaning of the relevant art, and should not be construed as ideal or overly formal unless expressly defined in various embodiments of the present invention. The present invention relates to a membrane humidifier that humidifies dry gas supplied from an external source using wet gas discharged from a fuel cell stack. In particular, the present invention relates to a membrane humidifier for a vehicle. As shown in FIG. 1, the present invention may include a housing 111 and first and second caps 120 and 130, which are components of a conventional membrane humidifier. More specifically, the present invention may include a housing 111 having a hollow fiber membrane disposed therein, as in the conventional case, and first and second caps 120 and 130 coupled to both ends of the housing 111. The housing 111 has a wet gas inlet 111a formed on one side through which wet gas is introduced, and a wet gas outlet 111b formed on the other side through which the wet gas introduced through the inlet 111a is discharged. As shown in FIG. 1, first and second caps 120 and 130 may be coupled to both ends of the housing 111, respectively. The first cap 120 is coupled to one side of the housing 111, and external air is introduced through the first cap 120. The second cap 130 is coupled to the other side of the housing 111, and the external air flows along the hollow fiber membrane, is humidified, and then is discharged. The hollow fiber membrane may be filled in a cartridge and detachably coupled to the housing 111. Both ends of the hollow fiber membrane and the cartridge are potted and fixed by a potting layer 22 (see FIG. 7). Meanwhile, moist exhaust gas discharged from the stack flows into the cartridge 100 inside the housing 111, and when the external air flows through the hollow fiber membrane 20, the moist gas flows along the outer surface of the hollow fiber membrane 20. The moist gas comes into contact with the outer surface of the hollow fiber membrane 20, transferring moisture to the inside of the hollow fiber membrane 20 and humidifying the external air. The humidified external air can then be supplied to the fuel cell stack through the second cap 130. Of course, according to the present embodiment, the hollow fiber membrane is provided in the form of a plurality of cartridges, but the form in which the hollow fiber membrane is provided inside the housing is not limited to the form of a plurality of cartridges.

[0009] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. A membrane humidifier 1 according to an embodiment of the present invention includes a housing 10, a hollow fiber membrane 20, a first cap 30, a second cap 40, and an injection part 50. As shown in Fig. 2, the housing 10 has an inlet 11 formed on one side through which a wet gas is introduced and an outlet 12 formed on the other side through which the wet gas introduced through the inlet 11 is discharged. The housing 10 provides a space in which the hollow fiber membrane 20 is disposed and a space through which the wet gas is introduced and the moisture of the wet gas is transferred to the outside air. Referring to Fig. 2, the inlet 11 and the outlet 12 are provided on the upper side of the housing 10. Of course, the positions of the inlet 11 and the outlet 12 are not limited thereto. The hollow fiber membrane 20 is accommodated inside the housing 10. External air flows through the interior of the hollow fiber membrane 20 and contacts the moist gas along the outer surface. As the moist gas contacts the outer surface of the hollow fiber membrane 20, moisture penetrates into the interior, thereby humidifying the external air. According to this embodiment, as shown in FIGS. 3 and 4, the hollow fiber membrane 20 is provided in the form of a cartridge 21. The cartridge 21, with the hollow fiber membrane 20 attached thereto, can be detachably mounted in the housing 10. The hollow fiber membrane 20 is disposed inside the cartridge 21, and both ends of the cartridge 21 and both ends of the hollow fiber membrane 20 are potted to form a potting layer (not shown) and fixed thereto. The potting layer may be formed by hardening a liquid polymer such as a liquid polyurethane resin. The cartridge 21 may be detachably coupled to the fastening portion 13 of the housing 10. According to this embodiment, a plurality of the cartridges 21 may be installed inside the housing 10. The hollow fiber membrane 20 is made of a material that allows moisture from the wet gas to permeate. For example, the hollow fiber membrane 20 may be made of 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 two or more thereof. The hollow fiber membrane 20 is potted and fixed in the cartridge 21, so that it can be attached to and detached from the housing 10 as a single unit.

[0010] The cartridge 21 has a first window 211 on one side for introducing wet gas and a second window 212 on the other side for discharging the wet gas introduced into the cartridge 21. Referring to FIG. 4, the first window 211 and the second window 212 may be arranged in a plurality of rows in the vertical direction. The size and number of rows of the first window 211 and the second window 212 may be variously changed. The wet gas introduced into the cartridge 21 through the first window 211 flows to the rear end and is then discharged to the outside through the second window 212. The wet gas discharged through the second window 212 may be discharged to the outside through the discharge hole 12 of the housing 10. The first cap 30 is coupled to one side of the housing 10. The first cap 30 has an inlet hole 31 through which external air is introduced. The second cap 40 is coupled to the other side of the housing 10, and external air introduced through the first cap 30 flows along the hollow fiber membranes 20, is humidified, and then is discharged. The second cap 40 has a discharge hole 41. The spray unit 50 is provided to flow the wet gas introduced through the inlet 11 toward the outlet 12 under a predetermined condition using air pressure. According to the present embodiment, the spray unit 50 may be provided inside the housing 10 in which the inlet 11 is formed. The spray unit 50 may provide air pressure in a direction perpendicular to the flow direction of the wet gas introduced through the inlet 11. That is, according to the present embodiment, the wet gas flows from the top to the bottom through the inlet 11 of the housing 10, and the spray unit 50 provides air pressure in a horizontal direction. According to the present embodiment, the spraying part 50 is formed by a bypass hole formed in the fastening part 13 to which the cartridge 21 is fastened. 113 The cartridge 21 is fastened to a fastening portion 13 provided on the housing 10, and the fastening portion 13 has a bypass hole for allowing the wet gas introduced through the inlet 11 to flow toward the outlet 12. 113 The bypass hole is formed. 113 is provided to prevent the pressure inside the housing 10 from increasing excessively due to the wet gas. The wet gas flows into the cartridge 21 through the first window 211, and a predetermined flow rate is maintained by the bypass hole 212. 113 The air can be discharged to the outlet 12 side via the According to this embodiment, as shown in FIGS. 5 and 6, the injection part 50 includes a body part 51, a supply passage 52, and an injection hole 53.

[0011] The body part 51 may be fixed inside the housing 10. As shown in Fig. 5, the body part 51 may be formed in a rectangular parallelepiped shape. Of course, the shape of the body part 51 is not limited thereto. The body part 51 has an injection hole 511 through which gas is injected. The supply passage 52 is provided to distribute the air pressure injected through the injection hole 511. The supply passage 52 includes a main passage 521 and distribution passages 522. According to this embodiment, the main passage 521 extends in one direction, and the distribution passages 522 extend from the main passage 521 to the bypass hole 511. 113 extends towards. The injection holes 53 are provided to inject air pressure and are formed at the end of the distribution passage 522. According to this embodiment, a plurality of injection holes 53 are provided and are spaced apart in the horizontal direction. Also, as shown in FIG. 6, each injection hole 53 is connected to the bypass hole 522. 113 The air pressure provided by the jetting unit 50 is applied to the bypass hole 52. 113 Bypass hole 113 The wet gas can be effectively discharged through the According to this embodiment, the air pressure of the spray unit 50 is the pressure of the external air. Specifically, the air pressure of the spray unit 50 is branched and provided before the external air is introduced through the first cap 30. As shown in FIG. 9, a branch flow path 60 is provided at the front end of the first cap 30 to branch the external air toward the spray unit 50. A flow control valve 70 is also provided in the branch flow path 60 to adjust the flow rate of the branched external air. One end of the branch flow path 60 is connected to the front end of the first cap 30, and the other end is connected to the spray hole 511 of the body part 51. Meanwhile, FIG. 9 differs from FIG. 2 in the shapes of the first and second caps 30 and 40 of the membrane humidifier. It goes without saying that, even in the embodiment of FIG. 2, the branch flow path 60 can be configured to provide external air from the front end of the first cap 30 to the inlet 11. According to this embodiment, a control unit 80 is provided to adjust the flow rate supplied by the injection unit 50. 8, the control unit 80 adjusts the flow rate of the external air supplied to the injection unit 50 by adjusting the opening of the flow rate control valve 70. According to the present embodiment, the control unit 80 guides the external air to the injection unit 50 under a predetermined condition, and directs the moist gas to the bypass hole under the predetermined condition. 113 Push it out to the side.

[0012] The control unit 80 may supply the external air to the spray unit 50 for a predetermined time after startup. The predetermined time may be set to one minute after startup. That is, the external air is supplied to the spray unit 50 through the branch flow path 60 until one minute after startup, and the spray unit 50 uses the air pressure of the external air to pump the moist gas through the bypass hole 62. 113 Can be pushed to the side. The predetermined time is not limited to one minute, but it is possible to prevent the wet gas from entering the bypass hole when one minute has passed since the start and the initial operation period has passed. 113 Discharging the air directly through the humidifier will reduce the humidifying efficiency of the membrane humidifier, and preventing over-humidification as an initial operating condition less than one minute after startup will increase the efficiency of the stack, so it is desirable to set the time to about one minute. In addition, the control unit 80 may provide air pressure through the injection unit 50 until the flow rate of the wet gas flowing into the inlet 11 after startup reaches a predetermined volume. The predetermined volume may be set to a flow rate of the wet gas of 2000 slpm (Standard Liter Per Minute). That is, the flow rate of the wet gas flowing from the stack to the inlet 11 of the housing 10 increases after startup, and in a low output section where the flow rate of the wet gas reaches 2000 slpm, the control unit 80 controls the injection unit 50 to inject the wet gas into the bypass hole. 113 Push it out to the side. Although the flow rate of the wet gas is not limited to 2000 slpm, the initial operation period is until the inflow rate of the wet gas reaches 2000 slpm, and the efficiency of the stack is improved by reducing the inflow of the wet gas into the housing 10 and preventing over-humidification. After the initial operation period, 113 The bypass flow rate of the humid gas escaping through the humidifier can be reduced to provide sufficient humidified air. Furthermore, according to an embodiment of the present invention, the control unit 80 may control the flow rate of the external air injected by the injection unit 50 to gradually decrease until the predetermined condition is reached. That is, the control unit 80 may gradually decrease the flow rate of the external air injected by the injection unit 50 until a predetermined time has elapsed since the start of the vehicle. For example, the control unit 80 may gradually decrease the flow rate of the external air injected by the injection unit 50 until a time reaching one minute from the start of the vehicle. In this case, the control unit 80 may control the flow rate control valve 70 to adjust the flow rate of the branched external air.

[0013] Furthermore, the control unit 80 may gradually reduce the flow rate provided by the injection unit 50 until the flow rate of the wet gas into the inlet 11 reaches a predetermined set value after the vehicle is started. For example, the control unit 80 may gradually reduce the flow rate of the external air injected by the injection unit 50 until the flow rate of the wet gas generated in the stack and flowing into the housing 10 reaches 2000 slpm after the vehicle is started. In this case, the control unit 80 may control the flow control valve 70 to adjust the flow rate of the branched external air. In this way, the control unit 80 gradually reduces the flow rate of external air injected by the injection unit 50, thereby preventing over-humidified air by the membrane humidifier from flowing into the stack during the initial startup and low output periods, and smoothly changes the operating state of the membrane humidifier to enable normal humidification as the system passes through the initial startup period, thereby providing the effect of stable system operation. The operation and effects of the membrane humidifier for fuel cells having the above-described configuration will now be described in detail. In a vehicle fuel cell, hydrogen and oxygen react in a stack while the vehicle engine is running to generate wet gas. The wet gas flows into the housing 10 of the membrane humidifier to humidify the air supplied to the stack. Referring to FIG. 7, the wet gas entering the inlet 11 of the housing 10 flows into the first window 211 of the cartridge 21 and flows along the outer surface of the hollow fiber membranes 20 arranged in a bundle form inside the cartridge 21 to the second window 212 and is discharged. The wet gas discharged to the second window 212 is discharged to the outside through the outlet 12 of the housing 10. Meanwhile, the blower 2 introduces external air into the housing 10 through the first cap 30. As the external air moves along the interior of the hollow fiber membranes 20, it transfers moisture from the wet gas and is humidified. The humidified external air is discharged through the second cap 40 and supplied to the stack. In the present invention, if excessively humidified air is provided to the stack in the initial stage of operation or in a low output environment, the power generation efficiency of the stack will be reduced. Therefore, in the initial stage of operation or in a low output environment, the humidified air is provided through a bypass hole. 113 This reduces the humidification rate. The control unit 80 branches the external air before it flows in through the first cap 30 and injects it through the injection unit 50 for a predetermined time after startup or until the flow rate of the wet gas discharged from the stack and flowing into the housing 10 reaches a predetermined set value. As described above, the predetermined time may be set to, for example, 1 minute, and the predetermined set value of the wet gas may be set to 2000 slpm. The control unit may stop supplying external air through the injection unit 50 if either one of the two conditions is met first.

[0014] The wet gas flowing into the inlet 11 by the injection part 50 is guided to the bypass hole 113 The wet gas is pushed out to the side through the bypass hole. 113The air flows toward the outlet 12 via the humidifier 14, reducing the amount of wet gas flowing into the hollow fiber membrane 20 of the cartridge 21. As a result, the humidification rate of the external air decreases, and excessively humidified air can be prevented from flowing into the stack via the membrane humidifier at the beginning of operation or in a low-output environment. In addition, it can provide an effect of preventing over-humidification caused by additional humidification of external air due to condensed water present inside the membrane humidifier during the initial operation and low output section. Condensed water is generated inside the membrane humidifier when the wet gas comes into contact with the housing 10, the outer surface of the hollow fiber membrane 20, and the surface of the cartridge 21. As the wet gas flows into the housing 10, the condensed water present inside the housing 10 transfers moisture to the external air flowing through the hollow fiber membrane 20 together with the wet gas, which can cause over-humidification. The present invention provides a bypass hole for the wet gas to pass through the bypass hole. 113 This relatively reduces the pressure of the moist gas, thereby further preventing the moisture of the condensed water remaining inside the housing 10 from being transferred to the outside air. Through this series of processes, the membrane humidifier according to the present invention contributes to improving the efficiency of the fuel cell stack. Although the present invention has been described in detail above by way of preferred embodiments, the present invention is not limited to the above embodiments and various modifications can be made within the scope of the present invention.

Claims

1. a housing having an inlet formed on one side through which a wet gas is introduced and an outlet formed on the other side through which the wet gas introduced through the inlet is discharged; a first cap coupled to one side of the housing to allow external air to flow in; a plurality of hollow fiber membranes provided inside the housing, through which external air introduced through the first cap flows and through which the wet gas contacts the outer surfaces of the hollow fiber membranes to humidify the external air; an injection unit that causes the wet gas flowing in through the inlet to flow toward the outlet under a predetermined condition using air pressure; a second cap coupled to the other side of the housing, through which the external air flows along the hollow fiber membrane, is humidified, and is then discharged.

2. the plurality of hollow fiber membranes are provided inside a cartridge that is detachably coupled to the housing; The housing is provided with a fastening portion for fastening the cartridge, The fastening portion is formed with a bypass hole that allows the wet gas introduced through the inlet to flow toward the outlet, 2. The membrane humidifier for a fuel cell according to claim 1, wherein the injector injects air pressure toward the bypass hole.

3. 2. The membrane humidifier for a fuel cell according to claim 1, wherein the air pressure of the injection part is branched and supplied before external air is introduced through the first cap.

4. a branch flow path at a front end of the first cap for branching the external air toward the injection portion; 4. The membrane humidifier for a fuel cell according to claim 3, further comprising: a flow rate control valve provided in the branch flow path for controlling the flow rate of the branched external air.

5. The injection unit has a plurality of injection holes for supplying the air pressure, 2. The membrane humidifier for a fuel cell according to claim 1, wherein the injection holes are spaced apart in a horizontal direction.

6. 6. The membrane humidifier for a fuel cell according to claim 5, wherein each of the injection holes is aligned to face the bypass hole.

7. 2. The membrane humidifier for a fuel cell according to claim 1, further comprising a control unit for adjusting the flow rate of the humidifier supplied by the injector.

8. The control unit 1) Providing air pressure through the injection unit until 1 minute has elapsed since starting; 2) The membrane humidifier for a fuel cell according to claim 7, wherein the injection unit provides air pressure until the flow rate of the humidified gas flowing into the inlet reaches 2000 slpm (Standard Liter Per Minute) after startup.

9. 2. The membrane humidifier for a fuel cell according to claim 1, wherein the flow rate provided by the injector is gradually reduced until a predetermined time after the vehicle is started.

10. 2. The membrane humidifier for a fuel cell according to claim 1, wherein the flow rate provided by the injection unit is gradually reduced after the vehicle is started until the flow rate of the humid gas flowing into the inlet reaches a predetermined set value.

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