KR20220168457A - Fuel cell membrane humidifier with improved assembly and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a fuel cell membrane humidifier capable of improving assembly ability by bolt fastening between a mid-case and a cap manufactured by plastic injection molding and a manufacturing method thereof. The fuel cell membrane humidifier according to an embodiment of the present invention comprises: a mid-case; a cap fastened to the mid-case; a first fastening fragment formed at an end side of the mid-case and having a fastening hole for fastening a bolt; a second fastening fragment formed at an end side of the cap and having a fastening hole for fastening a bolt; and an insert plate formed inside at least one of the first fastening fragment and the second fastening fragment.

Description

Fuel cell membrane humidifier with improved assembly and manufacturing method thereof {Fuel cell membrane humidifier with improved assembly and manufacturing method thereof}

The present invention relates to a fuel cell membrane humidifier and a method for manufacturing the same, and more particularly, to a fuel cell membrane humidifier capable of improving assemblyability by bolt fastening between a mid-case and a cap manufactured by plastic injection molding, and a method for manufacturing the same It is about.

A fuel cell is a power-generating cell that produces electricity by combining hydrogen and oxygen. Unlike general chemical cells such as dry batteries and storage batteries, fuel cells have the advantage of being able to continuously produce electricity as long as hydrogen and oxygen are supplied, and having no heat loss, the efficiency is about twice that of an internal combustion engine.

In addition, since the chemical energy generated by the combination of hydrogen and oxygen is directly converted into electrical energy, the emission of pollutants is low. Therefore, the fuel cell has the advantage of being environmentally friendly and reducing concerns about resource depletion due to increased energy consumption.

Depending on the type of electrolyte used, these fuel cells are largely classified into Polymer Electrolyte Membrane Fuel Cell (PEMFC), Phosphoric Acid Fuel Cell (PAFC), and Molten Carbonate Fuel Cell. : MCFC), solid oxide fuel cell (SOFC), and alkaline fuel cell (AFC).

Each of these fuel cells operates according to the fundamentally same principle, but the type of fuel used, operating temperature, catalyst, and electrolyte are different from each other. Among them, the polymer electrolyte fuel cell (PEMFC) is known to be the most promising not only for small-scale stationary power generation equipment but also for transportation systems because it operates at a lower temperature than other fuel cells and can be miniaturized due to its high power density.

One of the most important factors in improving the performance of a polymer electrolyte fuel cell (PEMFC) is a certain amount or more of a polymer electrolyte membrane (Polymer Electrolyte Membrane or Proton Exchange Membrane: PEM) of a membrane electrode assembly (MEA). It is to maintain the moisture content by supplying moisture. This is because when the polymer electrolyte membrane is dried, power generation efficiency is rapidly reduced.

Methods for humidifying the polymer electrolyte membrane include 1) a bubbler humidification method in which water is supplied by passing the target gas through a diffuser after filling a pressure-resistant container with water, and 2) supplying moisture required for the fuel cell reaction. There are a direct injection method that calculates and directly supplies moisture to a gas flow pipe through a solenoid valve, and 3) a humidification membrane method that supplies moisture to a fluidized gas layer using a polymer membrane.

Among these, a membrane humidification method in which a polymer electrolyte membrane is humidified by providing water vapor to air supplied to a polymer electrolyte membrane using a membrane that selectively transmits only water vapor contained in exhaust gas is advantageous in that it can reduce the weight and size of the membrane humidifier.

The selective permeable membrane used in the membrane humidification method is preferably a hollow fiber membrane having a large permeable area per unit volume when forming a module. In other words, when manufacturing a membrane humidifier using a hollow fiber membrane, high integration of the hollow fiber membrane with a large contact surface area is possible, so that even a small capacity can sufficiently humidify the fuel cell, the use of low-cost materials is possible, and high temperature in the fuel cell It has the advantage of being able to recover moisture and heat contained in discharged off-gas and reuse them through a membrane humidifier.

1 is a cross-sectional view showing a fuel cell membrane humidifier according to the prior art.

As shown in FIG. 1, the prior art fuel cell membrane humidifier 10 includes a humidification module 11 and a humidification module in which moisture is exchanged between air supplied from the outside and exhaust gas discharged from a fuel cell stack (not shown) It includes caps 12 coupled to both ends of (11).

One of the caps 12 supplies air supplied from the outside to the humidifying module 11, and the other supplies air humidified by the humidifying module 11 to the fuel cell stack.

The humidification module 11 includes a mid-case 11a and a mid-case 11a having an off-gas inlet 11b and an off-gas outlet 11c. At least one cartridge (20) disposed within. The cartridge 20 includes an inner case 23, and a plurality of hollow fiber membranes 21 and a potting part 22 for fixing both ends of the hollow fiber membrane bundle are formed inside the inner case 23. The fixing layer 13 between the inner case 23 and the mid-case 11a blocks the inner spaces of the caps 12 and the inner space of the mid-case 11a.

Air supplied from the outside flows along the hollow of the hollow fiber membrane 21 . Exhaust gas introduced into the mid-case 11a through the exhaust gas inlet 11b is introduced into the cartridge 20 through a plurality of holes MH1 provided in the inner case 23, and the outside of the hollow fiber membrane 21 After contacting the surface, it is discharged from the mid-case 11a through the plurality of holes MH2 and the exhaust gas outlet 11c. When the exhaust gas contacts the outer surface of the hollow fiber membrane 21, moisture contained in the exhaust gas permeates the hollow fiber membrane 21, thereby humidifying the air flowing along the hollow of the hollow fiber membrane 21.

Meanwhile, the mid-case 11a and the cap 12 fastened to the mid-case 11a are manufactured by plastic injection molding. After the mid-case 11a and the cap 12 are manufactured by plastic injection molding, they pass through a cooling process and are fastened using bolts.

During the cooling process, the fastening holes 11aa of the mid-case 11a and the fastening holes 12aa of the cap 12 are not aligned due to contraction/distortion caused by cooling. case often occurs. In this case, the product is treated as a defective product, resulting in a decrease in yield.

Korean Patent Publication No. 10-2019-0140855

An object of the present invention is to provide a fuel cell membrane humidifier and a method for manufacturing the same that can improve assembly by bolt fastening between a mid-case and a cap manufactured by plastic injection molding.

The fuel cell membrane humidifier according to an embodiment of the present invention,

mid-case; a cap fastened to the mid-case; a first fastening fragment formed at an end side of the mid-case and having a fastening hole for fastening a bolt; a second fastening fragment formed on an end side of the cap and having a fastening hole for fastening a bolt; An insert plate formed inside at least one of the first fastening segment and the second fastening segment.

In the fuel cell membrane humidifier according to an embodiment of the present invention, the mid-case and the cap may be formed of a plastic material, and the insert plate may be formed of a metal material.

In the fuel cell membrane humidifier according to an embodiment of the present invention, the insert plate may be formed to form a closed curve in a shape corresponding to the shape of the cap or the shape of the mid-case.

In the fuel cell membrane humidifier according to an embodiment of the present invention, the insert plate may have a screw thread formed at a position corresponding to the fastening hole.

In the fuel cell membrane humidifier according to an embodiment of the present invention, the screw thread may form a part of the fastening hole.

In addition, the method for manufacturing a fuel cell membrane humidifier according to an embodiment of the present invention,

A first step of manufacturing an insert plate made of metal; a second step of inserting the insert plate into a plastic casting for manufacturing at least one of a mid-case and a cap; and a third step of injection molding the plastic casting while the insert plate is inserted.

In the fuel cell membrane humidifier manufacturing method according to an embodiment of the present invention, the insert plate is formed on the end side of the mid-case and the first fastening segment formed with fastening holes for fastening bolts, and on the end side of the cap. formed and may be manufactured in a shape corresponding to at least one of the second fastening segments formed with fastening holes for fastening bolts.

In the fuel cell membrane humidifier manufacturing method according to an embodiment of the present invention, on the outer circumferential surface of the insert plate, at a position corresponding to at least one of the fastening holes of the first fastening segment and the fastening hole of the second fastening segment Threads may be formed.

In the fuel cell membrane humidifier manufacturing method according to an embodiment of the present invention, the screw thread may form a part of the fastening hole.

Other specific details of implementations according to various aspects of the present invention are included in the detailed description below.

According to an embodiment of the present invention, assemblability by bolt fastening between a mid-case and a cap manufactured by plastic injection molding may be improved.

1 is a cross-sectional view showing a fuel cell membrane humidifier according to the prior art.
2 is a cross-sectional view showing a fuel cell membrane humidifier according to an embodiment of the present invention.
FIG. 3 is an enlarged cross-sectional view of portion A of FIG. 2 .
4 is a flowchart illustrating a method of manufacturing a fuel cell membrane humidifier according to an embodiment of the present invention.
5 is a perspective view illustrating an insert plate used in a method of manufacturing a fuel cell membrane humidifier according to an embodiment of the present invention.
FIG. 6 is an enlarged view of the insert plate of FIG. 5 and a portion thereof.
7 is a partial perspective view showing a cross section of a mid-case in which an insert plate is inserted according to an embodiment of the present invention.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be exemplified and described in detail in the detailed description. However, it should be understood that this is not intended to limit the present invention to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as 'include' or 'having' are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded. Hereinafter, a fuel cell membrane humidifier and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.

2 is a cross-sectional view of a fuel cell membrane humidifier according to an embodiment of the present invention, and FIG. 3 is an enlarged cross-sectional view of part A of FIG. 2 .

Referring to FIG. 2 , a fuel cell membrane humidifier 100 according to an embodiment of the present invention includes a humidifying module 110 that humidifies air supplied from the outside with moisture in exhaust gas discharged from a fuel cell stack. Both ends of the humidifying module 110 are coupled to the cap 120 .

One of the caps 120 supplies air supplied from the outside to the humidifying module 110, and the other supplies air humidified by the humidifying module 110 to the fuel cell stack.

The humidification module 110 is a device in which moisture is exchanged between air supplied from the outside and exhaust gas, and is disposed in a mid-case 111a and a mid-case 111a having an exhaust gas inlet 111b and an exhaust gas outlet 111c It may include at least one cartridge 112 that is. The inner space of the mid-case 111a may be divided into a first space S1 and a second space S2 by the partition wall 111d.

Of course, according to the design, one of the caps 120 may supply the exhaust gas to the humidifying module 110 to flow inside the hollow fiber membrane, and the other may discharge the exhaust gas subjected to moisture exchange to the outside. In addition, in this case, external air is introduced through either the exhaust gas inlet 112 or the exhaust gas outlet 113, and the air humidified by the humidifying module 110 is supplied to the fuel cell stack through the other one. can The flow direction of the outside air and the flow direction of the exhaust gas may be in the same direction or opposite to each other.

The mid-case 111a and the cap 120 may be independently formed of hard plastic or metal, and may have a circular or polygonal cross section in the width direction. Circles include ovals, and polygons include polygons with rounded corners. For example, the hard plastic may be polycarbonate, polyamide (PA), polyphthalamide (PPA), polypropylene (PP), or the like.

The cartridge 112 may include a plurality of hollow fiber membranes 112a and a potting part 112b for fixing them to each other. Ends of the hollow fiber membranes 112a may be fixed to the potting part 112b. The hollow fiber membranes 112a may be disposed within the inner case 112c. A fixing layer 130 for fixing the cartridge 112 in the humidifying module 110 may be formed between the cartridge 112 and the mid-case 111a.

The hollow fiber membranes 112a are polysulfone resin, polyethersulfone resin, sulfonated polysulfone resin, polyvinylidene fluoride (PVDF) resin, polyacrylonitrile (PAN) resin, polyimide resin, polyamideimide resin, It may include a polyesterimide resin or a polymer film formed of a mixture of at least two of them, and the potting part 112b is formed by curing a liquid resin such as liquid polyurethane resin through a casting method such as deep potting or centrifugal potting. It can be.

Air supplied from the outside flows along the hollow of the hollow fiber membranes 112a. Exhaust gas introduced into the mid-case 111a through the exhaust gas inlet 111b is introduced into the cartridge 112 through a plurality of holes MH1 provided in the inner case 112c, and the outside of the hollow fiber membrane 112a. After contacting the surface, it is discharged from the mid-case 111a through the plurality of holes MH2 and the exhaust gas outlet 111c. When the exhaust gas contacts the outer surface of the hollow fiber membrane 112a, moisture contained in the exhaust gas permeates the hollow fiber membrane 112a to humidify the air flowing along the hollow of the hollow fiber membrane 112a.

Meanwhile, referring to FIGS. 2 and 3 , a first fastening fragment 111e is formed on the end side of the mid-case 111a, and a second fastening fragment 120a is formed on the end side of the cap 120. . A plurality of fastening holes H for inserting the bolt B are formed in the first fastening segment 111e and the second fastening segment 120a (see FIG. 7), and the first fastening segment 111e and the second fastening hole H are formed. An insert plate (150, see FIG. 5) is inserted and formed inside at least one fastening fragment of the fragment 120a. The insert plate 150 is formed to form a closed curve in a shape corresponding to the shape of the cap 120 or the shape of the mid-case 111a.

2 and 3 illustrate that the insert plate 150 is inserted into the first fastening piece 111e. Hereinafter, an example in which the insert plate 150 is formed only in the mid-case 111a will be described, but is not limited thereto.

The mid-case 111a and the cap 120 may be made of a plastic material, and the insert plate 150 may be made of a material harder than plastic. For example, the insert plate 150 may be formed of a metal material.

A screw thread 151 (see FIG. 6) is formed on the insert plate 150 at a position corresponding to the plurality of fastening holes H. The insert plate 150 may be partially exposed to the outside of the mid-case 111a at the position of the fastening hole (H), and constitute a part of the fastening hole (H). That is, a part of the fastening hole H may be made of the insert plate 150 made of a metal material, and the rest of the fastening hole H may be made of the first fastening piece 111e made of a plastic material.

During injection molding of the mid-case 111a, the insert plate 150 is inserted into a mold for manufacturing the mid-case 111a. The mid-case 111a is injection molded while including the insert plate 150 . Even if shrinkage/distortion occurs during the cooling process after injection molding, since the insert plate 150 is made of a metal material, it is not affected by shrinkage/distortion due to cooling, thereby significantly reducing the misalignment of the two fastening holes (H). can reduce Accordingly, assemblability can be improved by bolt fastening between the cap and the mid-case manufactured by plastic injection molding.

Next, a method of manufacturing a fuel cell membrane humidifier according to an embodiment of the present invention will be described with reference to FIGS. 4 to 7 . 4 is a flowchart illustrating a method of manufacturing a fuel cell membrane humidifier according to an embodiment of the present invention, and FIG. 5 is an insert plate used in the method of manufacturing a fuel cell membrane humidifier according to an embodiment of the present invention. ) is a perspective view shown, FIG. 6 is an enlarged view of the insert plate and a part thereof of FIG. 5, and FIG. 7 is a cross-sectional view of a mid-case in which an insert plate according to an embodiment of the present invention is inserted. It is a perspective view.

Referring to FIG. 4 , the method for manufacturing a fuel cell membrane humidifier according to an embodiment of the present invention includes an insert plate manufacturing step (S100), an insert plate insertion step (S200), an injection molding step (S300), and an assembling step (S400). ).

In the following description, as in FIGS. 2 and 3, inserting and manufacturing the insert plate 150 into the first fastening fragment 111e formed in the mid-case 111a is exemplarily described, but is not limited thereto.

First, an insert plate is manufactured in a shape corresponding to the first fastening segment 111e of the mid-case 111a. (S100) For example, as illustrated in FIG. 5, an insert plate 150 having a shape corresponding to the first fastening piece 111e is manufactured from a metal material.

At this time, as illustrated in FIGS. 6 and 7 , a screw thread 151 is formed at a position corresponding to the plurality of fastening holes H formed in the first fastening piece 111e among the outer circumferential surfaces of the insert plate 150 . The screw thread 151 may be formed in a semicircular shape. The screw thread 151 may constitute a part of the fastening hole (H).

That is, half of the fastening hole H of the first fastening segment 111e in which the insert plate 150 is formed may be a screw thread 151 made of metal, and the other half may be a screw thread made of plastic material.

Next, the insert plate 150 manufactured in step S100 is inserted into the plastic casting for manufacturing the mid-case 111a. (S200) At this time, the insert plate 150 is inserted into the position where the first fastening piece 111e of the mid-case 111a is to be formed. Also at this time, the thread 151 formed on the insert plate 150 aligns with the position of the fastening hole H of the first fastening piece 111e.

Next, with the insert plate 150 inserted, the plastic casting is injection molded (S300) to manufacture the mid-case 111a. The mid-case 111a is injection molded while including the insert plate 150 .

Even if shrinkage/distortion occurs during the cooling process after injection molding, since the insert plate 150 is made of a metal material, it is not affected by shrinkage/distortion due to cooling, thereby significantly reducing the misalignment of the two fastening holes (H). can reduce The cap 120 may also be injection molded according to the above-described processes S100 to S300.

Next, the injection-molded mid-case 111a and the cap 120 are assembled using fastening means such as bolts. (S400)

The plurality of fastening holes H formed in the first fastening segment 111e of the mid-case 111a and the second fastening segment 120a of the cap 120 may be aligned and fastened using a bolt B. there is. At this time, approximately half of the plurality of fastening holes (H) may be the screw thread 151 of the insert plate 150.

Although one embodiment of the present invention has been described above, those skilled in the art can add, change, delete, or add components within the scope not departing from the spirit of the present invention described in the claims. The present invention can be variously modified and changed by the like, and this will also be said to be included within the scope of the present invention.

100: fuel cell membrane humidifier
110: humidification module 111a: mid-case
111e: first fastening fragment 112: cartridge
120: cap 120a: second fastening fragment
150: insert plate 151: thread
H : fastening hole B : bolt

Claims (9)

mid-case;
a cap fastened to the mid-case;
a first fastening fragment formed at an end side of the mid-case and having a fastening hole for fastening a bolt;
a second fastening fragment formed on an end side of the cap and having a fastening hole for fastening a bolt;
an insert plate formed inside at least one of the first fastening segment and the second fastening segment;
A fuel cell membrane humidifier comprising a.
The method of claim 1,
The mid-case and the cap are formed of a plastic material, and the insert plate is a fuel cell membrane humidifier formed of a metal material.
The method according to claim 1, wherein the insert plate,
A fuel cell membrane humidifier formed to form a closed curve in a shape corresponding to the shape of the cap or the shape of the mid-case.
The method according to claim 1, wherein the insert plate,
A fuel cell membrane humidifier having a screw thread formed at a position corresponding to the fastening hole.
The method of claim 4,
A fuel cell membrane humidifier in which the screw thread forms a part of the fastening hole.
A first step of manufacturing an insert plate made of metal;
a second step of inserting the insert plate into a plastic casting for manufacturing at least one of a mid-case and a cap;
a third step of injection molding the plastic casting with the insert plate inserted;
Fuel cell membrane humidifier manufacturing method comprising a.
The method according to claim 6, wherein the insert plate,
A shape corresponding to at least one of a first fastening segment formed on the end side of the mid-case and having a fastening hole for fastening bolts, and a second fastening segment formed on the end side of the cap and having fastening holes for fastening bolts. Manufactured as, fuel cell membrane humidifier manufacturing method.
The method of claim 7,
On the outer circumferential surface of the insert plate, a screw thread is formed at a position corresponding to at least one of the fastening holes of the first fastening segment and the fastening hole of the second fastening segment, fuel cell membrane humidifier manufacturing method.
The method of claim 8,
The thread is a fuel cell membrane humidifier manufacturing method forming a part of the fastening hole.

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