Fuel cell humidifier with adjustable hollow fiber membrane length and fuel cell humidifier with adjustable gap between hollow fiber membranes

Abstract

A humidifier for a fuel cell in which the length of hollow fiber membranes or the gap between the hollow fiber membranes is adjusted according to the internal temperature of the humidifier that varies according to the output state of the fuel cell, the humidifier comprising: a housing; a hollow fiber membrane which is located inside the housing and through which dry air flows and through which wet air flows; and a potting material which is located at both ends of the hollow fiber membrane and fixes the distal end of the hollow fiber membrane, in which a first temperature-sensitive volume change member which expands and contracts according to temperature is inserted into the potting material such that the volume change member expands and contracts with respect to the first temperature-sensitive volume change member, and a second temperature-sensitive volume change member which expands and contracts with respect to the first temperature-sensitive volume change member. The potting material is divided into an inner potting material located inside the housing and an outer potting material located outside the housing and spaced apart from the inner potting material.

Description

Technical Field

[0001] This disclosure relates to a fuel cell humidifier. More specifically, this disclosure relates to a humidifier for a fuel cell, wherein the length of the hollow fiber membrane or the gap between the hollow fiber membranes is adjustable in response to the internal temperature of the humidifier, which varies according to the output state 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 batteries and accumulators, a fuel cell can continuously generate electricity as long as hydrogen and oxygen are supplied, and because there is no heat loss, its efficiency is twice that of an internal combustion engine.

[0003] Furthermore, fuel cells emit low levels of pollutants because the chemical energy generated by the combination of hydrogen and oxygen is directly converted into electrical energy. Therefore, fuel cells are not only environmentally friendly but also reduce concerns about resource depletion caused by increased energy consumption.

[0004] Fuel cells are classified according to the type of electrolyte used. Among them, polymer electrolyte fuel cells are known to be the most promising for small stationary power generation equipment and transportation systems because they can operate at lower temperatures and have high power density than other fuel cells, thus enabling miniaturization.

[0005] One of the key factors in improving the performance of polymer electrolyte fuel cells is maintaining the moisture content by supplying a certain amount of water to the polymer electrolyte membrane or proton exchange membrane (PEM) of the membrane electrode assembly (MEA). This is because power generation efficiency decreases rapidly when the polymer electrolyte membrane dries out.

[0006] Therefore, humidifiers for humidifying polymer electrolyte membranes are essential and very important. Among them, membrane humidification methods that use membranes that selectively allow water vapor to pass through have the advantage of enabling humidifiers to be lightweight and miniaturized.

[0007] When forming modules, the selectively permeable membrane used in the membrane humidification method can preferably be a hollow fiber membrane with a large permeation area per unit volume. In other words, when using hollow fiber membranes to manufacture humidifiers, the high integration of hollow fiber membranes with large contact surface areas enables fuel cells to be adequately humidified even in a small volume.

[0008] However, there are limitations due to the dense packing of hollow fiber membrane bundles into the shell to achieve high integration of the hollow fiber membrane and the potting of both ends of the hollow fiber membrane.

[0009] first, Figure 1This is a perspective view of a typical membrane humidifier 1 for a fuel cell. The housing 2 may be provided with a cover 3 at each end, and a bundle of hollow fiber membranes 4 may be contained in the housing 2 and fixed by a potting material 5.

[0010] One side of the cover 3 may be provided with a dry air inlet 6-1, and the other side of the cover 3 may include a dry air outlet 6-2, so that the dry air entering through the dry air inlet 6-1 passes through the hollow fiber membrane 4 and is discharged through the dry air outlet 6-2, flowing into the fuel cell stack (not shown).

[0011] The outer periphery of the housing 2 can be provided with a humidified air inlet 7-1 and a humidified air outlet 7-2. Unreacted humidified gas discharged from the fuel cell stack can enter the housing 2 through the humidified air inlet 7-1 to humidify the dry air flowing through the hollow fiber membrane 4, and then be discharged through the humidified air outlet 7-2.

[0012] Next, Figure 2 yes Figure 1 The diagram shows a cross-sectional view of a membrane humidifier for fuel cells cut along line I-I'. (Reference) Figure 2 This allows us to identify the problems with membrane humidifiers used in general fuel cells.

[0013] The membrane humidifier 1 for fuel cells can include a bundle of hollow fiber membranes 4 in the housing 2 to achieve high integration, wherein the two ends of the hollow fiber membranes 4 are fixed to the potting material 5.

[0014] The hollow fiber membrane 4 can be formed of a polymer material such that when exposed to a high temperature and high humidity environment during the operation of the humidifier 1, the length of the hollow fiber membrane 4 increases, and the elongated hollow fiber membrane 4 then vibrates due to the flow of incoming air.

[0015] As the length of the hollow fiber membrane 4 increases, the vibration amplitude increases and the stress intensity applied to the hollow fiber membrane 4 increases, thereby increasing the possibility of damage to the hollow fiber membrane 4. Therefore, it is crucial to appropriately reduce or pull back the increased length of the hollow fiber membrane 4 to prevent vibration, but the two ends of the hollow fiber membrane 4 are fixed by the potting material 5, and the potting material 5 is fixed to the shell 2, making length changes difficult.

[0016] As another question, see again Figure 1 The hollow fiber membrane 4 is installed in the housing 2 in the form of a bundle, which causes the humidification caused by the inflow of humid air to mainly occur on the outside of the hollow fiber membrane 4 bundle, resulting in insufficient humidification reaching the inside of the bundle.

[0017] Therefore, further technological development is needed to improve the humidification efficiency and durability of membrane humidifiers for fuel cells. Summary of the Invention

[0018] Technical issues

[0019] This disclosure aims to solve the above-mentioned problems and provide a membrane humidifier for fuel cells, wherein the length of the hollow fiber membrane can be adjusted according to the operating state of the fuel cell.

[0020] This disclosure also provides a membrane humidifier for fuel cells, wherein the gap between the hollow fiber membranes can be adjusted according to the operating status of the fuel cell.

[0021] Technical solution

[0022] To address the aforementioned problems, according to one aspect of this disclosure, a humidifier for a fuel cell with an adjustable hollow fiber membrane length includes: a housing; a hollow fiber membrane located inside the housing, with dry air flowing inside and humid air flowing outside; and a potting material located at both ends of the hollow fiber membrane and fixing the ends of the hollow fiber membrane, wherein a first temperature-sensitive volume change member that expands and contracts according to temperature is inserted into the potting material such that, relative to the first temperature-sensitive volume change member, the potting material is divided into an inner potting material located inside the housing and an outer potting material located outside the housing and spaced apart from the inner potting material.

[0023] In embodiments of this disclosure, the inner potting material may be spaced apart from the housing and have a gap therebetween, such that the hollow fiber membrane moves along its length as the first temperature-sensitive volume change member expands and contracts.

[0024] In embodiments of this disclosure, the external potting material can be fixed to the housing.

[0025] In embodiments of this disclosure, the first temperature-sensitive volume change member can contract as the temperature rises and expand as the temperature falls.

[0026] In embodiments of this disclosure, the first temperature-sensitive volume change component may include at least one selected from the group consisting of poly(N-isopropylacrylamide) (poly(NIPAM)), poly(N-isopropylacrylamide-co-allylamine) (poly(NIPAM-co-AA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate) (poly(NIPAM-co-DMAEMA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl acrylate) (poly(NIPAM-co-DMAEA)), poly(N-isopropylacrylamide-co-acrylic acid) (poly(NIPAM-co-AAc)), poly(N-isopropylacrylamide-co-methacrylic acid) (poly(NIPAM-co-MAAc)), poly(N,N-diethylacrylamide), poly(N-vinylcaprolactam), poly(ethylene glycol), and poly(ethylene glycol-b-propylene glycol-b-ethylene glycol).

[0027] To address the aforementioned problems, according to another aspect of this disclosure, a humidifier for a fuel cell with adjustable gaps between hollow fiber membranes includes: a housing; a hollow fiber membrane located inside the housing, with a first fluid flowing inside and a second fluid flowing outside; and a potting material located at both ends of the hollow fiber membrane and fixing the ends of the hollow fiber membrane, wherein a second temperature-sensitive volume change member that expands and contracts according to temperature is inserted into the potting material, such that the potting material is divided into a plurality of portions that move closer to or further away from each other about an axis parallel to the length direction of the hollow fiber membrane as the second temperature-sensitive volume change member expands and contracts.

[0028] In embodiments of this disclosure, a third temperature-sensitive volume change member that expands and contracts according to temperature can be inserted between the potting material and the housing in a manner that surrounds the potting material.

[0029] In embodiments of this disclosure, the second temperature-sensitive volume change member can expand as the temperature increases and contract as the temperature decreases.

[0030] In embodiments of this disclosure, the coefficient of thermal expansion of the second temperature-sensitive volume change component can be at least 50% greater than that of the potting material.

[0031] In embodiments of this disclosure, the third temperature-sensitive volume change member can contract as the temperature rises and expand as the temperature falls.

[0032] In embodiments of this disclosure, the third temperature-sensitive volume change component may include at least one selected from the group consisting of poly(N-isopropylacrylamide) (poly(NIPAM)), poly(N-isopropylacrylamide-co-allylamine) (poly(NIPAM-co-AA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate) (poly(NIPAM-co-DMAEMA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl acrylate) (poly(NIPAM-co-DMAEA)), poly(N-isopropylacrylamide-co-acrylic acid) (poly(NIPAM-co-AAc)), poly(N-isopropylacrylamide-co-methacrylic acid) (poly(NIPAM-co-MAAc)), poly(N,N-diethylacrylamide), poly(N-vinylcaprolactam), poly(ethylene glycol), and poly(ethylene glycol-b-propylene glycol-b-ethylene glycol).

[0033] Beneficial effects

[0034] According to the above configuration and combination relationship of this disclosure, the length of the hollow fiber membrane can be adjusted according to the operating state of the fuel cell, thereby reducing the stress on the hollow fiber membrane and thus improving the durability of the membrane humidifier for fuel cells.

[0035] Furthermore, the gap between the hollow fiber membranes can be adjusted according to the operating status of the fuel cell, thereby enabling effective humidification of the entire inner side of the hollow fiber membrane bundle during high-power operation of the fuel cell, while reducing humidification efficiency to reduce condensate formation during low-power operation of the fuel cell. Attached Figure Description

[0036] Figure 1 This is a perspective view of a typical membrane humidifier used in fuel cells.

[0037] Figure 2 yes Figure 1 The diagram shows a cross-sectional view of the membrane humidifier for fuel cells cut along line I-I'.

[0038] Figure 3 An embodiment of a membrane humidifier for a fuel cell with an adjustable hollow fiber membrane length is shown, wherein view (a) shows an exploded perspective view and view (b) shows a partial enlarged perspective view.

[0039] Figure 4 It is along Figure 3 A cross-sectional view of the section cut by line I-I'.

[0040] Figure 5 yes Figure 4 A partially enlarged view of the cross-section.

[0041] Figure 6 This is a partially enlarged view showing the temperature difference in an embodiment of the hollow fiber membrane length adjustable membrane humidifier for fuel cells according to the present disclosure.

[0042] Figure 7 An embodiment of a membrane humidifier for a fuel cell with adjustable gaps between hollow fiber membranes is shown, wherein view (a) shows an exploded perspective view and view (b) shows a partial enlarged perspective view.

[0043] Figure 8 It shows along Figure 7 A cross-sectional view of the section cut by line II-II' relative to the temperature difference, in which... Figure 8 View (a) is a cross-sectional view taken at a relatively low temperature environment due to the low-power operation of the fuel cell. Figure 8 View (b) is a cross-sectional view taken in a relatively high-temperature environment due to the high-power operation of the fuel cell.

[0044] Figure 9 This is a cross-sectional view showing a variant example of a membrane humidifier for fuel cells with adjustable gaps between hollow fiber membranes according to the present disclosure. Detailed Implementation

[0045] This specification clearly defines the scope of this disclosure, describes the principles of this disclosure, and discloses implementation methods to enable those skilled in the art to practice this disclosure. The disclosed implementation methods can be implemented in various forms.

[0046] The terms "comprising" or "may include," as used in the various embodiments of this disclosure, are intended to indicate the presence of the disclosed functions, operations, elements, etc., and do not exclude the presence or addition of one or more functions, operations, elements, etc. Furthermore, it should be understood that the terms "comprising" or "having," as used in the various embodiments of this disclosure, are intended to indicate the presence of the features, numbers, steps, operations, elements, components, or combinations thereof described in the specification, and do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0047] When an element is referred to as being “connected to” or “joined” to or by any other element, it should be understood that the element may be directly connected to or joined by other elements, but another new element may also be inserted between the element and other elements. Conversely, when an element is referred to as being “directly connected to” or “directly joined” to or by any other element, it should be understood that there is no other new element between the element and other elements.

[0048] Terms such as first and second, used in this specification, may be used to describe various components, but the component should not be limited to those terms. These terms may be used to distinguish one component from another.

[0049] Preferred embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0050] Figure 3 An embodiment of a membrane humidifier for a fuel cell with an adjustable hollow fiber membrane length is shown, wherein view (a) shows an exploded perspective view and view (b) shows a partial enlarged perspective view. Figure 4 It is along Figure 3 A cross-sectional view of the section cut by line I-I'. Figure 5 yes Figure 4 A partially enlarged view of the cross-section. Figure 6 This is a partially enlarged view showing the temperature difference in an embodiment of the hollow fiber membrane length adjustable membrane humidifier for fuel cells according to the present disclosure.

[0051] refer to Figure 3 View (a), embodiments of the present disclosure may include: a housing 100; a cover 110 located on each side of the housing 100; a dry air inlet 120 disposed on one side cover 110 to allow dry air to flow in; a dry air outlet 130 disposed on the other side cover 110 to allow dry air entering through the dry air inlet 120 to exit after passing through the hollow fiber membrane 200; and a humidified air inlet 14 disposed on the outer peripheral surface of the housing 100 to allow humidified air discharged from the fuel cell stack (not shown) to flow into the housing 100. 0; a humidified air outlet 150 through which humidified air humidifies the interior of the housing 100 is discharged; a hollow fiber membrane 200 located inside the housing 100, through which dry air entering via the dry air inlet 120 flows and through which humidified air entering via the humidified air inlet 140 flows, such that humidified air and dry air are humidified in such a way that the hollow fiber membrane 200 is interposed therebetween; and potting material 300 located at both ends of the hollow fiber membrane 200 to fix the ends of the hollow fiber membrane 200.

[0052] The housing 100 can surround and protect the hollow fiber membrane 200 and form the exterior of the membrane humidifier 10, and can have various shapes, not limited to these. Figure 3 The rectangular prism shape shown in view (a) is an example. For example, the housing 100 may have, but is not limited to, a cylindrical, polygonal, or polyhedral shape.

[0053] The cover 110 can be disposed on both sides of the housing 100 and can be separated from the housing 100 through which humid air flows, through which dry air flows, and its shape can be set in various shapes.

[0054] refer to Figure 3 View (b) and Figure 4 The hollow fiber membrane 200 can span the housing 100, with one end connected to the inside of the cover 110 on the dry air inlet 120 side and the other end connected to the inside of the cover 110 on the dry air outlet 130 side.

[0055] The potting material 300 can be disposed at both ends of the hollow fiber membrane 200 to fix the ends of the hollow fiber membrane 200. The potting material 300 can fix the ends of the hollow fiber membrane 200 or the bundle of hollow fiber membranes 200, and at the same time, it can be wholly or partially connected to the housing 100, so that the hollow fiber membrane 200 can be fixed and positioned at a predetermined position inside the housing 100.

[0056] In an embodiment of the hollow fiber membrane length adjustable membrane humidifier 10 for fuel cells disclosed herein, a first temperature-sensitive volume change member 400 that expands and contracts according to temperature can be inserted into the potting material 300.

[0057] The potting material 300 can be separated by inserting the first temperature-sensitive volume change member 400, and thus is divided into an inner potting material 310 located inside the housing 100 and an outer potting material 320 located outside the housing 100 relative to the first temperature-sensitive volume change member 400.

[0058] The inner side of housing 100 can refer to the side closer to the interior of housing 100 where humid air flows, while the outer side of housing 100 can refer to the side closer to the interior of cover 110 where dry air flows.

[0059] For example, the potting material 300 can be configured to have a predetermined thickness and be perpendicular to the length direction of the hollow fiber membrane 200. Figure 3 View (b) and Figure 4 The plate-shaped structure (x-axis) and the first temperature-sensitive volume change member 400 can be similarly configured to have a thickness less than that of the potting material 300 and perpendicular to the length direction of the hollow fiber membrane 200. Figure 3 View (b) and Figure 4 The plate-shaped structure (x-axis) can be inserted into the potting material 300, allowing the potting material 300 to be divided into two plates, one of which can be located on one side of the first temperature-sensitive volume change member 400. Figure 3 View (b) and Figure 4 In the +x direction), and one of them can be on the other side of the first temperature-sensitive volume change member 400 ( Figure 3 View (b) and Figure 4 (in the -x direction).

[0060] refer to Figure 5 In embodiments of this disclosure, the outer potting material 320 may be fixed to the housing 100, and the inner potting material 310 may be spaced apart from the housing 100 and have a gap S therebetween.

[0061] The external potting material 320 allows the hollow fiber membrane 200 to be fixedly contained in the housing 100 at a predetermined position or in a predetermined arrangement, preventing humid air entering the housing 100 from escaping through a path other than the humid air outlet 150 by separating the interior and exterior of the housing 100, and preventing dry air between the housing 100 and the cover 110 from entering the interior of the housing 100 through a path other than the hollow fiber membrane 200.

[0062] The inner potting material 310 may be spaced apart from the housing 100 with a gap S therebetween, such that it moves along the length of the hollow fiber membrane 200 as the first temperature-sensitive volume change member 400 disposed between the outer potting material 320 and the inner potting material 310 expands and contracts.

[0063] The size of the gap S is preferably set within a range that will not cause the inner potting material 310 and the hollow fiber membrane 200 fixed by the inner potting material 310 to sag due to the gap S, thereby causing excessive deformation or damage to the hollow fiber membrane 200.

[0064] Therefore, the inner potting material 310 can move with the expansion and contraction of the first temperature-sensitive volume change member 400, thereby causing the hollow fiber membrane 200 fixed by the inner potting material 310 to move in the length direction of the hollow fiber membrane 200. The movement of the inner potting material 310 disposed at each end of the hollow fiber membrane 200 can stretch or compress the hollow fiber membrane 200 in the length direction of the hollow fiber membrane 200, thereby adjusting the stress applied to the hollow fiber membrane 200.

[0065] For example, such as Figure 5 As shown, based on one side potting material 300, an outer potting material 320 connects and fixes the housing 100 and the potting material 300. The first temperature-sensitive volume change component 400 is disposed on the inner side of the fixed outer potting material 320. Figure 5 (in the +x direction), and the inner potting material 310 can be disposed on the inner side of the first temperature-sensitive volume change member 40 ...). Figure 5 (in the +x direction) and has a gap S with the housing 100.

[0066] In some cases, an insert member may be further included, which surrounds the outer peripheral surface of the inner potting material 310 to fill the gap S between the inner potting material 310 and the housing 100, and has a smooth surface facing the housing 100, which allows it to slide.

[0067] Next, in an embodiment of the hollow fiber membrane length adjustable membrane humidifier 10 for fuel cells disclosed herein, the first temperature-sensitive volume change member 400 may be configured as a material that contracts as the temperature rises and expands as the temperature falls.

[0068] For example, the first temperature-sensitive volume change member 400 can be configured as a hydrogel that shrinks and expands according to temperature or temperature and moisture, and specific examples may include poly(N-isopropylacrylamide) (poly(NIPAM)), poly(N-isopropylacrylamide-co-allylamine) (poly(NIPAM-co-AA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate) (poly(NIPAM-co-DMAEMA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl acrylate) (poly(NIPAM-co-DMAEA)), poly(N-isopropylacrylamide-co-acrylic acid) (poly(NIPAM-co-AAc)), and poly(N-isopropylacrylamide-co-methacrylic acid) At least one of the following groups: (poly(NIPAM-co-MAAc)), poly(N,N-diethylacrylamide), poly(N-vinylcaprolactam), poly(ethylene glycol), and poly(ethylene glycol-b-propylene glycol-b-ethylene glycol).

[0069] However, this disclosure is not limited thereto.

[0070] refer to Figure 6 In order to describe the function and effect of the hollow fiber membrane length adjustable membrane humidifier 10 for fuel cells with the aforementioned structure of this disclosure, Figure 6 View (a) is a cross-section and a partially enlarged view of the membrane humidifier showing the elongation of the hollow fiber membrane 200 due to the operation of the fuel cell.

[0071] During fuel cell operation, the hollow fiber membrane 200 may be subjected to continuous downward pressure from the humid air flowing into the housing 100. Figure 6 (in the -z direction). At the same time, the hollow fiber membrane 200 may vibrate due to the strong flow pressure of the dry air flowing inside the hollow fiber membrane 200, and this vibration may exert stress on the hollow fiber membrane 200.

[0072] In particular, as the sagging of the hollow fiber membrane 200 increases, the vibration amplitude increases, thereby exacerbating the stress intensity applied to the hollow fiber membrane 200. During high-power operation of the fuel cell, the stress intensity applied to the hollow fiber membrane 200 increases with the increase in the inlet pressure of humid air and the flow pressure of dry air, thereby increasing the possibility of damage to the hollow fiber membrane 200.

[0073] Figure 6 View (b) shows the state when the internal temperature of the housing 100 becomes relatively high due to the high-power operation of the fuel cell.

[0074] refer to Figure 6 View (b) shows that as the internal temperature of the housing 100 increases, the first temperature-sensitive volume change member 400 can contract, causing the inner potting material 310 to move toward the outer potting material 320 connected to and fixed to the housing 100.

[0075] Therefore, the inner potting material 310 at each end of the hollow fiber membrane 200 moves toward the outer potting material 320, pulling the hollow fiber membrane 200 fixed to the inner potting material 310 toward both ends, and restoring the relaxed hollow fiber membrane 200 to a taut state.

[0076] Because the hollow fiber membrane 200 remains taut, vibrations caused by fluid flow are reduced, thereby alleviating stress on the hollow fiber membrane 200. Ultimately, the durability of both the hollow fiber membrane 200 and the membrane humidifier 10 for the fuel cell can be significantly improved.

[0077] refer to Figures 7 to 9 The following describes an embodiment of a membrane humidifier for a fuel cell capable of adjusting the gap between hollow fiber membranes.

[0078] For components that correspond to the same or simple design modifications as those described in the foregoing embodiments and have the same function and effect, the same reference numerals or superscripts (e.g., 100, 100') will be used to indicate that they may have the same function and effect, and repeated descriptions will be omitted or minimized.

[0079] Figure 7 View (a) is a perspective view showing an embodiment of a membrane humidifier for fuel cells with adjustable gaps between hollow fiber membranes according to the present disclosure. Figure 7 View (b) is a partially enlarged view showing an embodiment of a membrane humidifier for fuel cells with adjustable gaps between hollow fiber membranes according to the present disclosure. Figure 8 It shows along Figure 7 A cross-sectional view of the section cut by line II-II' relative to the temperature difference, in which... Figure 8 View (a) is a cross-sectional view taken at a relatively low temperature environment due to the low-power operation of the fuel cell. Figure 8 View (b) is a cross-sectional view taken in a relatively high-temperature environment due to the high-power operation of the fuel cell. Figure 9 This is a cross-sectional view showing a variant example of a membrane humidifier for fuel cells with adjustable gaps between hollow fiber membranes according to the present disclosure.

[0080] refer to Figure 7View (a), embodiments of the present disclosure may include: a housing 100'; a cover 110' located on each side of the housing 100'; a dry air inlet 120' disposed on one side cover 110' to allow dry air to flow in; a dry air outlet 130' disposed on the other side cover 110' to allow dry air entering through the dry air inlet 120' to exit after passing through the hollow fiber membrane 200'; and a humidified air inlet 14 disposed on the outer peripheral surface of the housing 100' to allow humidified air discharged from the fuel cell stack (not shown) to flow into the housing 100'. 0'; a humidified air outlet 150' through which humidified air humidifies the interior of the housing 100' is discharged; a hollow fiber membrane 200' located inside the housing 100', and dry air entering through the dry air inlet 120' flows inside it, while humidified air entering through the humidified air inlet 140' flows outside it, such that humidified air and dry air are humidified in such a way that the hollow fiber membrane 200' is between them; and potting material 300' located at both ends of the hollow fiber membrane 200' to fix the ends of the hollow fiber membrane 200'.

[0081] refer to Figure 7 View (b) and Figure 8 In an embodiment of the hollow fiber membrane membrane humidifier 10' for fuel cells with adjustable gaps between the hollow fiber membranes disclosed herein, a second temperature-sensitive volume change member 500 that expands and contracts according to temperature can be inserted into the potting material 300'.

[0082] The second temperature-sensitive volume change component 500 can divide the potting material 300' into multiple parts, such that each part can be inserted to move away from or towards each other around an axis parallel to the length direction of the hollow fiber membrane 200' in response to the expansion and contraction of the second temperature-sensitive volume change component 500.

[0083] For example, such as Figure 7 As shown in view (b), the second temperature-sensitive volume change member 500 can be inserted to divide the potting material 300' into four parts in a cross-sectional view cut along line II-II', such that one end of the second temperature-sensitive volume change member 500 is along the length direction of the hollow fiber membrane 200' (or Figure 7 The portion of the potting material 300' extends across the x-axis direction of the view (b) and is exposed to the dry air between the cap 110' and the housing 100', with its other end exposed to the humid air inside the housing 100'. Therefore, each segment of the potting material 300' can move independently.

[0084] However, it is not limited to this, such as Figure 9As shown in view (a), the potting material 300' can be configured to be divided into eight or more equal portions. Furthermore, in the manner in which the potting material 300' is divided, such as... Figure 9 As shown in view (b), the potting material 300' can be divided into parts of different sizes and shapes.

[0085] At this time, the second temperature-sensitive volume change member 500 may include a material that expands as the temperature rises and contracts as the temperature falls.

[0086] The second temperature-sensitive volume change component 500 may further comprise a material whose coefficient of thermal expansion is at least 30% greater than that of the potting material 300'. Preferably, the second temperature-sensitive volume change component 500 may further comprise a material whose coefficient of thermal expansion is at least 40% greater than that of the potting material 300'. More preferably, the second temperature-sensitive volume change component 500 may further comprise a material whose coefficient of thermal expansion is at least 50% greater than that of the potting material 300'.

[0087] Therefore, when the internal temperature of the housing 100' rises due to the high-power operation of the fuel cell, the second temperature-sensitive volume change component 500 expands, thereby increasing the gap between the portions of the potting material 300' and the gap between the hollow fiber membranes 200' fixed to the potting material 300', thus enabling smooth humidification to reach the inside of the hollow fiber membrane bundles 200'.

[0088] On the other hand, when the internal temperature of the housing 100' decreases due to low-power operation of the fuel cell, the second temperature-sensitive volume change member 500 can relatively shrink, thus reducing the gaps between portions of the potting material 300'. The gaps between the hollow fiber membranes 200' fixed to the potting material 300' also decrease, causing humidification to primarily occur on the hollow fiber membranes 200' facing the housing 100' and located on the outer side, while humidification of the inner side of the hollow fiber membrane bundles is reduced, thereby decreasing the overall humidification efficiency. Therefore, the amount of humidification during low-power operation of the fuel cell is reduced, thereby reducing the likelihood of condensate formation.

[0089] When the second temperature-sensitive volume change component 500 is made of a material with a thermal expansion coefficient greater than that of the potting material 300', under conditions where the internal temperature of the housing 100' increases due to the high-power operation of the fuel cell, the second temperature-sensitive volume change component 500 can expand more than the potting material 300', thereby effectively widening the gap between the divisions of the potting material 300'; under conditions where the internal temperature of the housing 100' decreases due to the low-power operation of the fuel cell, the second temperature-sensitive volume change component 500 can contract more than the potting material 300', thereby effectively narrowing the gap between the divisions of the potting material 300', thus enabling sensitive humidification according to the output state of the fuel cell.

[0090] Return to reference Figure 7 View (b) and Figure 8 In an embodiment of the hollow fiber membrane membrane humidifier 10' for fuel cells with adjustable gap between the membranes disclosed herein, a third temperature-sensitive volume change member 600 that expands and contracts according to temperature can be inserted between the potting material 300' and the housing 100'.

[0091] For example, such as Figure 7 View (b) and Figure 8 As shown, the four parts divided by the potting material 300' can each be configured such that the third temperature-sensitive volume change member 600 surrounds the surface facing the housing 100'.

[0092] The third temperature-sensitive volume change member 600 can be disposed between the potting material 300' and the housing 100', thereby providing a space when the second temperature-sensitive volume change member 500 expands, so that the dividing portions of the potting material 300' can be separated from each other.

[0093] Therefore, in the embodiment of the membrane humidifier 10' for fuel cells with adjustable gaps between hollow fiber membranes disclosed herein, the third temperature-sensitive volume change member 600 can be configured as a material that contracts as the temperature rises and expands as the temperature falls.

[0094] For example, the third temperature-sensitive volume change member 600 can be configured as a hydrogel that contracts as the temperature increases and expands as the temperature decreases, and specific examples may include poly(N-isopropylacrylamide) (poly(NIPAM)), poly(N-isopropylacrylamide-co-allylamine) (poly(NIPAM-co-AA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate) (poly(NIPAM-co-DMAEMA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl acrylate) (poly(NIPAM-co-DMAEA)), poly(N-isopropylacrylamide-co-acrylic acid) (poly(NIPAM-co-AAc)), and poly(N-isopropylacrylamide-co-methacrylic acid). At least one of the following groups: (poly(NIPAM-co-MAAc)), poly(N,N-diethylacrylamide), poly(N-vinylcaprolactam), poly(ethylene glycol), and poly(ethylene glycol-b-propylene glycol-b-ethylene glycol). However, this disclosure is not limited thereto.

[0095] Return to reference Figure 8 and Figure 9 To describe the function, role, and effect of the membrane humidifier 10' for fuel cells with adjustable gaps between hollow fiber membranes of this disclosure, a second temperature-sensitive volume change member 500, 500', or 500'' can be inserted into the potting material 300' to divide the potting material 300' into independent portions, and the second temperature-sensitive volume change member 500, 500', or 500'' can include a material that expands with increasing temperature and contracts with decreasing temperature, so that the divided portions of the potting material 300' can withstand the relatively high temperature environment caused by the high-power operation of the fuel cell ( Figure 8 View (b) and Figure 9 In views (b) and (d), the portions of the potting material 300' are far apart from each other, and the divisions of the potting material 300' can withstand the relatively low temperature environment caused by the low power operation of the fuel cell. Figure 8 View (a) and Figure 9 The views (a) and (c) are close to each other.

[0096] A third temperature-sensitive volume change member 600, 600', or 600'' may be inserted between the housing 100' and the potting material 300', and the third temperature-sensitive volume change member 600, 600', or 600'' may include a material that contracts as the temperature rises and expands as the temperature falls, thereby providing a space during high-power operation of the fuel cell to allow portions of the potting material 300' to be separated from each other, and maintaining a seal between the potting material 300' and the housing 100' during low-power operation of the fuel cell, thereby preventing humid air inside the housing 100' from mixing with dry air inside the cover 110'.

[0097] The gap between the hollow fiber membranes 200' can be adjusted according to the output state of the fuel cell based on the changes in the second temperature-sensitive volume change components 500, 500' or 500'', the third temperature-sensitive volume change components 600, 600' or 600'', and the potting material 300'.

[0098] Specifically, as the gaps between the hollow fiber membranes 200' increase during high-power operation of the fuel cell, the humidification efficiency can be significantly improved by smoothly humidifying the inner side of the hollow fiber membrane bundle 200'. Furthermore, as the gaps between the hollow fiber membranes 200' decrease during low-power operation of the fuel cell, the humidification efficiency relatively decreases. Therefore, the problem of over-humidification or condensate formation mentioned in the low-power section can be easily improved.

[0099] Therefore, in the embodiment of the membrane humidifier 10' for fuel cells with adjustable gaps between hollow fiber membranes disclosed in this disclosure, the humidification amount can be actively controlled and over-humidification can be prevented, thereby improving the durability of the membrane humidifier for fuel cells.

[0100] Those skilled in the art to which this disclosure pertains will understand that this disclosure can be implemented in different specific ways without departing from its technical spirit or essential characteristics. Therefore, the above embodiments should be construed as illustrative in all respects and not as limiting.

[0101] For example, although this disclosure has been described with reference to one embodiment shown in the accompanying drawings, those skilled in the art will understand that various modifications and changes may be made to the embodiments therein without departing from the spirit and scope of this disclosure.

[0102] The true scope of this disclosure is defined by the following claims rather than the detailed description, and the meaning and scope of the claims, as well as all variations or modifications derived from their equivalents, should be interpreted as falling within the scope of this disclosure.

Claims

1. A membrane humidifier for a fuel cell with an adjustable hollow fiber membrane length, the membrane humidifier comprising: case; A hollow fiber membrane is located inside the housing, with dry air flowing inside and humid air flowing outside. as well as Encapsulating material, located at both ends of the hollow fiber membrane and fixing the ends of the hollow fiber membrane, Specifically, a first temperature-sensitive volume change component that expands and contracts according to temperature is inserted into the potting material, such that, relative to the first temperature-sensitive volume change component, the potting material is divided into an inner potting material located inside the housing and an outer potting material located outside the housing and spaced apart from the inner potting material.

2. The membrane humidifier according to claim 1, wherein, The inner potting material is spaced apart from the shell and has a gap therebetween, so that the inner potting material moves along the length of the hollow fiber membrane as the first temperature-sensitive volume change component expands and contracts.

3. The membrane humidifier according to claim 1, wherein, The external potting material is fixed to the housing.

4. The membrane humidifier according to claim 1, wherein, The first temperature-sensitive volume change component contracts as the temperature rises and expands as the temperature falls.

5. The membrane humidifier according to claim 1, wherein, The first temperature-sensitive volume change component comprises at least one selected from the group consisting of poly(N-isopropylacrylamide) (poly(NIPAM)), poly(N-isopropylacrylamide-co-allylamine) (poly(NIPAM-co-AA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate) (poly(NIPAM-co-DMAEMA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl acrylate) (poly(NIPAM-co-DMAEA)), poly(N-isopropylacrylamide-co-acrylic acid) (poly(NIPAM-co-AAc)), poly(N-isopropylacrylamide-co-methacrylic acid) (poly(NIPAM-co-MAAc)), poly(N,N-diethylacrylamide), poly(N-vinylcaprolactam), poly(ethylene glycol), and poly(ethylene glycol-b-propylene glycol-b-ethylene glycol).

6. A membrane humidifier for a fuel cell with adjustable gaps between hollow fiber membranes, the membrane humidifier comprising: case; A hollow fiber membrane is located inside the shell, and a first fluid flows inside it and a second fluid flows outside it; as well as Encapsulating material, located at both ends of the hollow fiber membrane and fixing the ends of the hollow fiber membrane, In this process, a second temperature-sensitive volume change component that expands and contracts according to temperature is inserted into the potting material, such that the potting material is divided into multiple parts, which move closer to or further away from each other around an axis parallel to the length direction of the hollow fiber membrane as the second temperature-sensitive volume change component expands and contracts.

7. The membrane humidifier according to claim 6, wherein, A third temperature-sensitive volume change component that expands and contracts according to temperature is inserted between the potting material and the housing in a manner that surrounds the potting material.

8. The membrane humidifier according to claim 6, wherein, The second temperature-sensitive volume change component expands as the temperature increases and contracts as the temperature decreases.

9. The membrane humidifier according to claim 6, wherein, The coefficient of thermal expansion of the second temperature-sensitive volume change component is at least 50% greater than that of the potting material.

10. The membrane humidifier according to claim 7, wherein, The third temperature-sensitive volume change component contracts as the temperature rises and expands as the temperature falls.

11. The membrane humidifier according to claim 7, wherein, The third temperature-sensitive volume change component comprises at least one selected from the group consisting of poly(N-isopropylacrylamide) (poly(NIPAM)), poly(N-isopropylacrylamide-co-allylamine) (poly(NIPAM-co-AA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate) (poly(NIPAM-co-DMAEMA)), poly(N-isopropylacrylamide-co-2-(dimethylamino)ethyl acrylate) (poly(NIPAM-co-DMAEA)), poly(N-isopropylacrylamide-co-acrylic acid) (poly(NIPAM-co-AAc)), poly(N-isopropylacrylamide-co-methacrylic acid) (poly(NIPAM-co-MAAc)), poly(N,N-diethylacrylamide), poly(N-vinylcaprolactam), poly(ethylene glycol), and poly(ethylene glycol-b-propylene glycol-b-ethylene glycol).

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