Fuel cell membrane humidifier

Abstract

This invention relates to a fuel cell membrane humidifier capable of actively controlling the flow rate of exhaust gas flowing from the fuel cell stack according to the output status of the fuel cell. According to one embodiment of the invention, the fuel cell membrane humidifier includes: an intermediate shell having an inlet through which wetting gas supplied from the fuel cell stack is introduced, and an outlet through which the wetting gas is discharged; a cylindrical body disposed inside the intermediate shell and housing a plurality of hollow fiber membranes; a bypass space formed in the space between the intermediate shell and the cylindrical body; and an active blocking member for controlling the opening degree of the bypass space according to the temperature of the wetting gas introduced through the inlet.

Description

Technical Field

[0001] This invention relates to a fuel cell membrane humidifier, which can actively adjust the flow rate of exhaust gas flowing into the fuel cell stack according to the output status of the fuel cell. Background Technology

[0002] A fuel cell is a power-generating battery that produces electricity by combining hydrogen and oxygen. Unlike conventional chemical batteries such as dry cell batteries or storage batteries, fuel cells have the following advantages: they can continuously generate electricity as long as there is a supply of hydrogen and oxygen, and they are about twice as efficient as internal combustion engines because there is no heat loss.

[0003] Furthermore, because the chemical energy generated through the combination of hydrogen and oxygen is directly converted into electrical energy, pollutant emissions are reduced. Therefore, fuel cells offer the advantages of being environmentally friendly and reducing concerns about resource depletion due to increased energy consumption.

[0004] Based on the type of electrolyte used, these fuel cells are broadly classified into, for example, 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).

[0005] These fuel cells operate on essentially the same principle, but differ in the type of fuel used, operating temperature, catalyst, electrolyte, and other factors. Among these cells, polymer electrolyte membrane fuel cells (PEMFCs) are known to be the most promising, suitable not only for small stationary power generation devices but also for transportation systems, because PEMFCs operate at lower temperatures than other fuel cells and can be miniaturized due to their high output density.

[0006] One of the most important factors in improving the performance of polymer electrolyte membrane fuel cells (PEMFCs) is maintaining the moisture content by supplying a certain amount or more of water to the polymer electrolyte membrane (or proton exchange membrane: PEM) of the membrane electrode assembly (MEA). This is because power generation efficiency deteriorates rapidly when the polymer electrolyte membrane dries out.

[0007] Examples of methods for humidifying polymer electrolyte membranes include: 1) a bubbler humidification scheme, which fills a pressure vessel with water and then supplies moisture by passing the target gas through a diffuser; 2) a direct injection scheme, which calculates the amount of moisture required for the fuel cell reaction and supplies moisture directly to the gas flow channel via a solenoid valve; and 3) a humidification membrane scheme, which uses a polymer separation membrane to supply moisture to the fluidized gas layer.

[0008] Among these methods, the advantage of membrane humidification schemes that humidify the polymer electrolyte membrane by using a membrane that selectively permeates only the water vapor contained in the exhaust gas to supply water vapor to the polymer electrolyte membrane is that the weight and size of the humidifier can be reduced.

[0009] The selective permeation membrane used in the membrane humidification scheme is preferably a hollow fiber membrane with a large permeation area per unit volume when formed into a module. That is, when using a hollow fiber membrane to manufacture a humidifier, the advantages are that high integration of the hollow fiber membrane with a large contact surface area is possible, so that even with a small capacity, the fuel cell can be adequately humidified, low-cost materials can be used, and the moisture and heat contained in the exhaust gas discharged from the fuel cell at high temperature can be recovered and reused by the humidifier.

[0010] Figure 1 This is an exploded perspective view showing a fuel cell humidifier according to related technologies. (See attached image.) Figure 1 As shown, the fuel cell humidifier 100 of the related technology includes: a humidification module 110 in which moisture exchange occurs between air supplied from the outside and exhaust gas discharged from the fuel cell stack (not shown); and a cover 120 coupled to both ends of the humidification module 110.

[0011] One of the covers 120 delivers externally supplied air to the humidification module 110, and the other delivers air humidified by the humidification module 110 to the fuel cell stack.

[0012] The humidification module 110 includes: an intermediate shell 111 having an exhaust gas inlet 111a and an exhaust gas outlet 111b; and a plurality of hollow fiber membranes 112 within the intermediate shell 111. The ends of a bundle of hollow fiber membranes 112 are encapsulated on a fixing layer 113. The fixing layer 113 is typically formed by curing a liquid polymer, such as liquid polyurethane resin, using a casting process. The fixing layer 113 encapsulating the ends of the hollow fiber membranes 112, and a resin layer 114 between the fixing layer 113 and the intermediate shell 111, isolate the interior space of the cover 120 from the interior space of the intermediate shell 111. Similar to the fixing layer 113, the resin layer 114 is typically formed by curing a liquid polymer, such as liquid polyurethane resin, using a casting process.

[0013] Externally supplied air flows along the hollow core of the hollow fiber membrane 112. The exhaust gas flowing into the intermediate shell 111 through the exhaust gas inlet 111a contacts the outer surface of the hollow fiber membrane 112 and then exits from the intermediate shell 111 through the exhaust gas outlet 111b. When the exhaust gas contacts the outer surface of the hollow fiber membrane 112, the moisture contained in the exhaust gas permeates into the hollow fiber membrane 112, humidifying the air flowing along the hollow core of the hollow fiber membrane 112. Summary of the Invention

[0014] Technical issues

[0015] One object of the present invention is to provide a fuel cell membrane humidifier that can actively adjust the flow rate of exhaust gas flowing into the fuel cell stack according to the output status of the fuel cell.

[0016] Technical solution

[0017] A fuel cell membrane humidifier according to one embodiment of the present invention includes:

[0018] The intermediate shell includes an inlet through which wetting gas supplied from the fuel cell stack flows into the interior, and an outlet through which the wetting gas is discharged; a cylinder disposed within the intermediate shell and having a plurality of hollow fiber membranes housed therein; a bypass space formed in the space between the intermediate shell and the cylinder; and an active blocking member configured to adjust the opening degree of the bypass space according to the temperature of the wetting gas flowing into the interior through the inlet.

[0019] In a fuel cell membrane humidifier according to an embodiment of the present invention, the active barrier member may be made of a thermosensitive material that can be compressed or expanded according to the temperature of the wetting gas flowing into the interior through the inlet.

[0020] In a fuel cell membrane humidifier according to an embodiment of the present invention, the active barrier member may be made of a metallic material that expands within a first temperature range of the wetting gas flowing into the interior through the inlet and contracts within a second temperature range below the first temperature range.

[0021] In a fuel cell membrane humidifier according to an embodiment of the present invention, the active blocking member can thermally expand within a first temperature range to partially close the bypass space, and thermally contract within a second temperature range to partially open the bypass space.

[0022] In a fuel cell membrane humidifier according to an embodiment of the present invention, the first temperature range may be the temperature range of the wetting gas flowing into the interior through the inlet within a first output range of the fuel cell stack, and the second temperature range may be the temperature range of the wetting gas flowing into the interior through the inlet within a second output range smaller than the first output range.

[0023] According to an embodiment of the present invention, the fuel cell membrane humidifier may further include: a base member for fixing the active blocking member to the inner wall of the intermediate shell.

[0024] A fuel cell membrane humidifier according to another embodiment of the present invention includes:

[0025] An intermediate shell includes an inlet through which wetting gas supplied from the fuel cell stack flows into the interior, and an outlet through which the wetting gas is discharged. A plurality of receiving holes separated by at least one partition member are formed in the intermediate shell; a plurality of cylindrical bodies disposed in the plurality of receiving holes and having a plurality of hollow fiber membranes housed therein; a plurality of bypass spaces formed in the space between the intermediate shell and the cylindrical bodies and in the space between the partition member and the cylindrical bodies; and an active blocking member configured to adjust the opening degree of at least one of the plurality of bypass spaces according to the temperature of the wetting gas flowing into the interior through the inlet.

[0026] In a fuel cell membrane humidifier according to another embodiment of the invention, the active barrier member may be made of a thermosensitive material that can be compressed or expanded according to the temperature of the wetting gas flowing into the interior through the inlet.

[0027] In a fuel cell membrane humidifier according to another embodiment of the invention, the active barrier member may be made of a metallic material that expands within a first temperature range of the wetting gas flowing into the interior through the inlet and contracts within a second temperature range below the first temperature range.

[0028] In a fuel cell membrane humidifier according to another embodiment of the invention, the active blocking member can thermally expand within a first temperature range to partially close the bypass space and thermally contract within a second temperature range to partially open the bypass space.

[0029] In a fuel cell membrane humidifier according to another embodiment of the present invention, the first temperature range may be the temperature range of the wetting gas flowing into the interior through the inlet within a first output range of the fuel cell stack, and the second temperature range may be the temperature range of the wetting gas flowing into the interior through the inlet within a second output range smaller than the first output range.

[0030] According to another embodiment of the present invention, a fuel cell membrane humidifier may further include: a base member for fixing the active blocking member to the intermediate shell or the separating member.

[0031] Other specific details of embodiments of various aspects of the present invention are described in detail below.

[0032] Beneficial effects

[0033] According to the present invention, the flow rate of exhaust gas flowing into the fuel cell stack can be actively adjusted according to the output status of the fuel cell.

[0034] Furthermore, according to the present invention, since the degree of opening of the bypass space is automatically adjusted according to the temperature of the exhaust gas flowing into the membrane humidifier from the fuel cell stack, the number of components and installation space required for bypass implementation can be significantly reduced. Attached Figure Description

[0035] Figure 1 This is an exploded perspective view showing a fuel cell membrane humidifier according to related technologies.

[0036] Figure 2 This is an exploded perspective view showing a fuel cell membrane humidifier according to the present invention.

[0037] Figure 3 The fuel cell membrane humidifier according to the present invention is along Figure 2 The exploded cross-sectional view taken from line II.

[0038] Figure 4 The fuel cell membrane humidifier according to the present invention is along Figure 2 The combined cross-sectional view taken from line II.

[0039] Figure 5 and Figure 6 yes Figure 4 An enlarged cross-sectional view of part A.

[0040] Figure 7 This is an exploded perspective view of an embodiment of a fuel cell membrane humidifier according to the present invention, in which two cylindrical bodies are coupled to an intermediate shell.

[0041] Figure 8 The fuel cell membrane humidifier according to the present invention is along Figure 7 A partial cross-sectional view taken from line II-II.

[0042] Figure 9 This is an exploded perspective view of an embodiment of a fuel cell membrane humidifier according to the present invention, in which three cylinders are coupled to an intermediate shell. Detailed Implementation

[0043] Since various modifications can be made to this invention, there are multiple embodiments of this invention, and specific embodiments will be described and detailed in this specification. However, it is to be understood that this is not intended to limit the invention to the specific embodiments, and all variations, equivalents, or substitutions are included within the concept and scope of this invention.

[0044] The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include the plural forms. It is understood that the terms “comprising,” “including,” and / or “containing” in this specification specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. Hereinafter, a fuel cell membrane humidifier according to an embodiment of the invention will be described with reference to the accompanying drawings.

[0045] Figure 2 This is an exploded perspective view of the fuel cell membrane humidifier according to the present invention. Figure 3 The fuel cell membrane humidifier according to the present invention is along Figure 2 The exploded cross-sectional view taken from line II. Figure 4 The fuel cell membrane humidifier according to the present invention is along Figure 2 The combined cross-sectional view taken by line II in the middle. Figure 5 and Figure 6 yes Figure 4 An enlarged cross-sectional view of part A in the image.

[0046] Reference Figures 2 to 4 According to one embodiment of the present invention, a fuel cell membrane humidifier 1 is designed to humidify the battery gas to be supplied to a fuel cell stack (not shown). The battery gas to be supplied to the fuel cell stack can be fuel gas or air. The fuel cell membrane humidifier 1 according to an embodiment of the present invention includes: a humidification module 2 for humidifying the battery gas; a first cover 3 coupled to one end of the humidification module 2; and a second cover 4 coupled to the other end of the humidification module 2.

[0047] The humidification module 2 humidifies the battery gas to be supplied to the fuel cell stack. A first cover 3 can be coupled to one end of the humidification module 2. A second cover 4 can be coupled to the other end of the humidification module 2. The first cover 3 can deliver externally supplied battery gas to the humidification module 2. The second cover 4 can deliver the battery gas humidified by the humidification module 2 to the fuel cell stack. The second cover 4 can deliver externally supplied battery gas to the humidification module 2, and the first cover 3 can deliver the battery gas humidified by the humidification module 2 to the fuel cell stack.

[0048] The humidification module 2 includes a cylinder 21 and an intermediate shell 22.

[0049] The cylinder 21 includes a plurality of hollow fiber membranes 211. The hollow fiber membranes 211 can be implemented as the cylinder 21 and modularized. Therefore, the hollow fiber membranes 211 can be installed inside the intermediate shell 22 by coupling the cylinder 21 to the intermediate shell 22. Therefore, the fuel cell membrane humidifier 1 according to an embodiment of the present invention can improve the convenience of operation for installing, separating and replacing the hollow fiber membranes 211.

[0050] The cylindrical body 21 may include an inner shell 210 for housing the hollow fiber membrane 211. The hollow fiber membrane 211 may be disposed inside the inner shell 210 and modularly configured. The hollow fiber membrane 211 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, polyesterimide resin, or a mixture of two or more thereof.

[0051] The cylindrical body 21 may include a first filling section 212. The first filling section 212 secures one side of each hollow fiber membrane 211. The first filling section 212 may be formed to be hollow without sealing the hollow fiber membranes 211. The first filling section 212 may be formed by curing liquid resin, such as liquid polyurethane resin, through a casting process. The first filling section 212 may secure the inner shell 210 and one side of each hollow fiber membrane 211.

[0052] The cylinder 21 may include a second filling section 213. The second filling section 213 secures the other side of each hollow fiber membrane 211. The second filling section 213 may be formed to leave the hollow of the hollow fiber membrane 211 unsealed. This allows battery gas to be supplied to the fuel cell stack to be supplied to the hollow of the hollow fiber membrane 211 without being obstructed by the second filling section 213 and the first filling section 212, to be humidified, and to be supplied to the fuel cell stack. The second filling section 213 may be formed by curing a liquid resin, such as liquid polyurethane resin, using a casting process. The second filling section 213 may secure the inner shell 210 and the other side of each hollow fiber membrane 211.

[0053] The cylindrical body 21 is coupled to the intermediate shell 22. The cylindrical body 21 may be disposed inside the intermediate shell 22. The intermediate shell 22 may include a receiving port for receiving the cylindrical body 21. The receiving port may be formed to pass through the intermediate shell 22 in a first axial direction (X-axis direction). The intermediate shell 22 may include an inlet 221 and an outlet 222. A wetting gas containing moisture may pass through the interior of the intermediate shell 22 via the inlet 221 and be supplied to the interior of the inner shell 210, and then contact the outer surface of the hollow fiber membrane 211. In this process, the moisture contained in the wetting gas may permeate into the hollow fiber membrane 211 to humidify the battery gas flowing along the hollow of the hollow fiber membrane 211. The humidified battery gas may be discharged from the hollow fiber membrane 211 and then supplied to the fuel cell stack. After humidifying the battery gas, the wetting gas may be discharged to the outside of the inner shell 210, pass through the interior of the intermediate shell 22, and then be discharged to the outside of the intermediate shell 22 via the outlet 222. The inlet 221 may be connected to the fuel cell stack. In this case, the wetting gas can be the exhaust gas discharged from the fuel cell stack.

[0054] Simultaneously, a wetting gas is formed in the inner shell 210 through an inlet hole 210a into which it flows inward, and a wetting gas that humidifies the battery gas flowing hollowly along the hollow fiber membrane 211 is discharged through an outlet hole 210b. In this case, the wetting gas can be supplied through inlet 221 to the space between the inner surface of the intermediate shell 22 and the outer surface of the cylinder 21, supplied to the interior of the inner shell 210 through inlet hole 210a, contacting the outer surface of the hollow fiber membrane 211, humidifying the battery gas flowing hollowly along the hollow fiber membrane 211, and discharged through outlet hole 210b between the inner surface of the intermediate shell 22 and the outer surface of the cylinder 21, and discharged to the outside of the intermediate shell 22 through outlet 222. A plurality of inlet holes 210a can be formed in the inner shell 210. The inlet holes 210a can be arranged to be spaced apart from each other in a first axial direction (X-axis direction). A plurality of outlet holes 210b can be formed in the inner shell 210. The outlet holes 210b can be configured to be spaced apart from each other in the first axial direction (X-axis direction).

[0055] The humidification module 2 may include multiple packing members 23 and 23'. Packing members 23 and 23' seal the space between the cylinder 21 and the intermediate shell 22 to prevent direct mixing of the battery gas to be supplied to the fuel cell stack and the wetting gas supplied to the interior of the intermediate shell 22. Packing members 23 and 23' may be inserted between the cylinder 21 and the intermediate shell 22. In this case, the cylinder 21 may be inserted into first through holes 23a and 23a' formed in the packing members 23 and 23'. Packing members 23 and 23' may be disposed on both sides of the cylinder 21. Although not shown, a resin layer may be formed on both sides of the cylinder 21 in place of the packing members 23 and 23'. The resin layer may be formed by curing a liquid polymer, such as liquid polyurethane resin, using a casting process.

[0056] The first cover 3 is coupled to one end of the humidification module 2. The space between the first cover 3 and the cylinder 21 can be sealed relative to the space between the cylinder 21 and the intermediate shell 22 by a filler member 23 or a resin layer.

[0057] The second cover 4 is coupled to the other end of the humidification module 2. The space between the first cover 4 and the cylinder 21 can be sealed relative to the space between the cylinder 21 and the intermediate shell 22 by a filler member 23' or a resin layer.

[0058] Meanwhile, in the fuel cell membrane humidifier of the related technology, a partition wall is formed to connect the inner wall of the intermediate shell 22 to the outer wall of the cylinder 21 to prevent the wetting gas flowing into the interior through the inlet 221 from being discharged directly through the outlet 222 instead of flowing into the cylinder 21.

[0059] Meanwhile, the amount of humidification required for the wetting gas (hereinafter also referred to as "exhaust gas") flowing into the fuel cell stack varies depending on the fuel cell's output. That is, a large amount of humidification is required at high output, while a relatively small amount of humidification is required at low output.

[0060] In related technologies, in order to adjust the humidification amount according to the output conditions, a separate bypass is installed outside the membrane humidifier, and a portion of the humidifying gas flowing through inlet 221 is discharged to the outside. Therefore, to achieve this, a separate bypass flow path connected to the outside should be installed on the flow path connecting the fuel cell stack to inlet 221, a valve for discharging a portion of the exhaust gas to the outside should be installed, and a control unit for detecting the output conditions to adjust the valve opening degree should be installed, etc. Therefore, there are problems such as an increase in the number of required components and an increase in installation space due to the components.

[0061] The embodiments of the present invention solve these problems of the related technologies with a simple structure, thereby significantly reducing costs and installation space due to the reduction in the number of components and miniaturization.

[0062] Therefore, according to an embodiment of the present invention, the fuel cell membrane humidifier includes an active blocking member 223, which connects the inner wall of the intermediate shell 22 to the outer wall of the cylinder 21, such as... Figure 3 and Figure 4 As shown in the image.

[0063] The active blocking member 223 is made of a thermosensitive material that can compress or expand according to temperature (heat). The active blocking member 223 can also be made of a metallic material that expands at high temperatures and contracts at low temperatures. High temperature can be defined as a first temperature range, and low temperature can be defined as a second temperature range below the first temperature range.

[0064] The active blocking member 223 can thermally expand at high temperatures to partially seal the space between the intermediate shell 22 and the cylinder 21, and thermally contract at low temperatures to partially open the space between the intermediate shell 22 and the cylinder 21 (hereinafter, bypass space 220).

[0065] The exhaust gas flowing from the fuel cell stack to the fuel cell membrane humidifier 1 has different temperatures depending on the output conditions. That is, the exhaust gas temperature is relatively high under high output conditions and relatively low under low output conditions. High output can be defined as a first output range, and low output can be defined as a second output range smaller than the first output range.

[0066] Figure 5 This illustrates the high-output scenario. Figure 6 This refers to the low-output scenario. Figure 5 and Figure 6 In the reference numeral 223a, a base member is indicated, which can be used to fix the active blocking member 223 made of metal to the inner wall of the intermediate shell 22 made of plastic, but is not required.

[0067] like Figure 5 In high-output conditions, the exhaust gas temperature is high, and a portion of the exhaust gas flowing into the interior through inlet 221 flows into the cylinder 21 through inlet hole 210a of inner shell 210, where moisture exchange occurs during flow, and the remaining portion transfers heat to active blocking member 223 while flowing through bypass space 220 between intermediate shell 22 and cylinder 21. Figure 5 As shown, the active barrier member 223 absorbs heat from the exhaust gas and expands thermally to seal the bypass space 220. Therefore, a portion of the exhaust gas that does not flow into the inlet hole 210a is redirected by the active barrier member 223 and flows into the cylinder 21 through the inlet hole 210a, where it exchanges moisture as it flows.

[0068] like Figure 6 In the case of low output, the exhaust gas temperature is low, and a portion of the exhaust gas flowing into the interior through inlet 221 flows into the cylinder 21 through inlet hole 210a of inner shell 210, where moisture exchange occurs during flow. However, the remaining portion absorbs heat from active blocking member 223 while flowing through bypass space 220. Figure 6 As shown, the active barrier member 223, which has had its heat removed by the exhaust gas, thermally contracts to partially open the bypass space 220. Therefore, a portion of the exhaust gas that does not flow into the inlet orifice 210a flows through the bypass space 220 via the opened active barrier member 223 and is then discharged to the outside of the intermediate shell 22 through the outlet 222.

[0069] In an embodiment of the invention, the active blocking member 223 is capable of expanding or contracting according to the output condition to adjust the opening degree of the bypass space 220, and does not necessarily have to completely close or fully open the bypass space 220.

[0070] According to the fuel cell membrane humidifier of the embodiment of the present invention described above, since the active blocking member 223 automatically adjusts the opening degree of the bypass space 220 according to the temperature of the exhaust gas flowing into the membrane humidifier from the fuel cell stack, the number of components and installation space required for bypass implementation can be significantly reduced.

[0071] Reference Figure 7 and Figure 8 The fuel cell membrane humidifier 1 according to the invention can be implemented such that a plurality of cylinders 21 and 21' are coupled to an intermediate shell 22. In this case, the intermediate shell 22 may include a plurality of receiving holes for receiving the cylinders 21 and 21', and the plurality of receiving holes may be separated by a partition member 224. Furthermore, in this case, a bypass space 220 is formed not only between the intermediate shell 22 and the cylinders 21, but also between the partition member 224 and the cylinders 21, and an active blocking member 223 may be formed in at least one of the plurality of bypass spaces 220.

[0072] exist Figure 7 and Figure 8 The diagram already shows two of the cylinders 21 and 21' coupled to the intermediate shell 22, but the invention is not limited thereto, and the fuel cell membrane humidifier 1 according to the invention can be implemented such that three cylinders 21, 21' and 21″ are coupled to the intermediate shell 22, as shown in the diagram. Figure 9 As shown in the figure. In addition, although not shown, the fuel cell membrane humidifier 1 according to the invention can be implemented such that four or more cylinders 21 are coupled to the intermediate shell 22.

[0073] Although embodiments of the present invention have been described above, those skilled in the art can modify or alter the present invention by adding, changing, deleting, or supplementing components, without departing from the concept of the present invention as described in the claims, and such modifications or alterations will also be considered to be included within the scope of the present invention.

Claims

1. A fuel cell membrane humidifier, comprising: The intermediate shell includes an inlet through which wetting gas supplied from the fuel cell stack flows into the interior, and an outlet through which the wetting gas is discharged. A cylindrical body disposed inside the intermediate shell and having a plurality of hollow fiber membranes housed therein; Bypass space, which is formed in the space between the intermediate shell and the cylindrical body; and An active barrier component configured to adjust the opening degree of the bypass space based on the temperature of the humidifying gas flowing into the interior through the inlet. The active blocking component is made of a metallic material, which expands within a first temperature range of the wetting gas flowing into the interior through the inlet and contracts within a second temperature range below the first temperature range. Wherein, the first temperature range is the temperature range of the wetting gas flowing into the interior through the inlet within the first output range of the fuel cell stack, and The second temperature range is the temperature range of the wetting gas flowing into the interior through the inlet within a second output range that is smaller than the first output range.

2. The fuel cell membrane humidifier according to claim 1, further comprising: A base member for securing the active blocking member to the inner wall of the intermediate shell.

3. A fuel cell membrane humidifier, comprising: The intermediate shell includes an inlet through which wetting gas supplied from the fuel cell stack flows into the interior, and an outlet through which the wetting gas is discharged. A plurality of receiving holes are formed in the intermediate shell, separated by at least one partition member. Multiple cylindrical bodies are disposed in multiple receiving holes and have multiple hollow fiber membranes housed therein; Multiple bypass spaces are formed in the space between the intermediate shell and the cylinder and in the space between the partition member and the cylinder; and An active blocking member configured to adjust the opening degree of at least one of the plurality of bypass spaces based on the temperature of the wetting gas flowing into the interior through the inlet. The active blocking component is made of a metallic material, which expands within a first temperature range of the wetting gas flowing into the interior through the inlet and contracts within a second temperature range below the first temperature range. Wherein, the first temperature range is the temperature range of the wetting gas flowing into the interior through the inlet within the first output range of the fuel cell stack, and The second temperature range is the temperature range of the wetting gas flowing into the interior through the inlet within a second output range that is smaller than the first output range.

4. The fuel cell membrane humidifier according to claim 3, further comprising: A base member for securing the active blocking member to the intermediate shell or the partition member.

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