Intermediate case of humidifier for fuel cell and humidifier for fuel cell

Abstract

The present invention relates to an intermediate case for a humidifier for a fuel cell, and relates to a humidifier for a fuel cell, the intermediate case comprising: an intermediate body accommodating at least one cylinder comprising a plurality of hollow fiber membranes; and a bypass portion that transfers the first gas introduced through the first gas inlet of the first cover and introduces the first gas to the cylinder accommodated inside the intermediate body, in which the bypass portion protrudes from the intermediate body at a position overlapping with the cylinder accommodated inside the intermediate body.

Description

Technical Field

[0001] The present disclosure relates to a humidifier for a fuel cell configured to supply humidified gas to the fuel cell. Background Art

[0002] Fuel cells have an advantage in that, unlike conventional chemical batteries such as dry cells or storage batteries, they can continuously generate electricity as long as hydrogen and oxygen are supplied, and there is no heat loss, so the efficiency of the fuel cell is about twice as high as that of an internal combustion engine.

[0003] In addition, the fuel cell directly converts chemical energy generated by the combination of hydrogen and oxygen into electrical energy, thereby emitting a small amount of pollutants. Therefore, the fuel cell has the advantage that the fuel cell is environmentally friendly and can reduce concerns about resource depletion due to increased energy consumption.

[0004] Such fuel cells can be roughly classified into polymer electrolyte membrane fuel cells (PEMFC), phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), solid oxide fuel cells (SOFC), or alkaline fuel cells (AFC) based on the kind of electrolyte used.

[0005] These fuel cells are basically operated by the same principle, but they differ from each other in the type of fuel used, operating temperature, catalyst and electrolyte. Among these fuel cells, it is known that polymer electrolyte membrane fuel cell (PEMFC) is most advantageous for transportation systems and small stationary power generation equipment because the polymer electrolyte membrane fuel cell operates at a lower temperature than other fuel cells and the output density of the polymer electrolyte membrane fuel cell is high, and therefore, the polymer electrolyte membrane fuel cell can be miniaturized.

[0006] One of the most important factors for improving the performance of a polymer electrolyte membrane fuel cell (PEMFC) is to supply a predetermined amount of water or more to the polymer electrolyte membrane or proton exchange membrane (PEM) of a membrane electrode assembly (MEA) in order to maintain the moisture content. This is because if the polymer electrolyte membrane or proton exchange membrane is dry, the power generation efficiency is drastically reduced.

[0007] The following methods are used as methods for humidifying polymer electrolyte membranes or proton exchange membranes: 1) a bubbler humidification method, in which a pressure vessel is filled with water and a target gas is passed through a diffuser to supply moisture; 2) a direct injection method, in which the amount of moisture required to be supplied for a fuel cell reaction is calculated, and moisture is directly supplied to a gas flow conduit through an electromagnetic valve; and 3) a membrane humidification method, in which moisture is supplied to a gas fluidized bed using a polymer separation membrane.

[0008] Among these methods, the membrane humidification method of using a membrane configured to selectively transmit only water vapor contained in the exhaust gas to provide water vapor to the air supplied to the polymer electrolyte membrane or the proton exchange membrane so as to humidify the polymer electrolyte membrane or the proton exchange membrane has the advantage that the weight and size of the humidifier can be reduced.

[0009] When forming a module, a hollow fiber membrane having a large transmission area per unit volume is suitable for use in a selective permeable membrane used in a membrane humidification method. That is, when a humidifier is manufactured using a hollow fiber membrane, high integration of a hollow fiber membrane having a large contact surface area is possible, whereby a fuel cell can be sufficiently humidified even with a small capacity, inexpensive materials can be used, and moisture and heat contained in exhaust gas discharged from a fuel cell at a high temperature can be collected, and the collected moisture and heat can be reused by the humidifier.

[0010] Figure 1 is a schematic exploded perspective view of a conventional humidifier for a fuel cell.

[0011] like Figure 1 As shown in , a conventional membrane humidification type humidifier 100 includes: a humidification module 110, in which moisture is exchanged between air supplied from the outside and exhaust gas exhausted from a fuel cell stack (not shown); and covers 120 respectively connected to opposite ends of the humidification module 110.

[0012] One of the covers 120 transmits air supplied from the outside to the humidification module 110 , and the other transmits air humidified by the humidification module 110 to the fuel cell stack.

[0013] 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 in the intermediate shell 111. The opposite ends of the hollow fiber membranes 112 are potted in a fixing layer 113. Generally, each fixing layer 113 is formed by hardening a liquid polymer such as a liquid polyurethane resin using a casting method. The fixing layer 113 in which the ends of the hollow fiber membranes 112 are potted and the resin layer 114 provided between the fixing layer 113 and the intermediate shell 111 isolate the internal space of the cover 120 from the internal space of the intermediate shell 111. Similar to the fixing layer 113, each resin layer 114 is generally formed by hardening a liquid polymer such as a liquid polyurethane resin using a casting method.

[0014] Air supplied from the outside flows along the hollow of the hollow fiber membrane 112. Exhaust gas introduced into the intermediate housing 111 through the exhaust gas inlet 111a contacts the outer surface of the hollow fiber membrane 112, and is discharged from the intermediate housing 111 through the exhaust gas outlet 111b. When the exhaust gas contacts the outer surface of the hollow fiber membrane 112, moisture contained in the exhaust gas is transmitted through the hollow fiber membrane 112 to humidify the air flowing along the hollow of the hollow fiber membrane 112.

[0015] In this case, generally, the exhaust gas introduced into the intermediate case 111 flows toward the hollow fiber membrane 112. As a result, generally, there is a problem that the pressure of the exhaust gas introduced into the intermediate case 111 is directly applied to the hollow fiber membrane 112, causing the hollow fiber membrane 112 to be damaged or destroyed. Summary of the invention

[0016] Technical issues

[0017] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide an intermediate housing of a humidifier for a fuel cell and a humidifier for a fuel cell capable of reducing damage or destruction to a hollow fiber membrane.

[0018] Technical Solution

[0019] In order to achieve the above-mentioned object, the present disclosure may include the following configurations.

[0020] The intermediate housing of the humidifier for fuel cells according to the present disclosure is provided in the humidifier for fuel cells, the humidifier comprising: a humidification module configured to humidify dry gas supplied to a fuel cell stack with moisture; a first cover connected to one end of the humidification module; and a second cover connected to the other end of the humidification module, and may include: an intermediate body configured to accommodate at least one cylinder including a plurality of hollow fiber membranes; and a bypass unit configured to bypass the first gas introduced through the first gas inlet of the first cover so as to flow toward the cylinder accommodated in the intermediate body. The bypass unit may protrude from the intermediate body at a position where the bypass unit overlaps with the cylinder accommodated in the intermediate body.

[0021] A humidifier for a fuel cell according to the present disclosure may include: a humidification module configured to humidify dry gas supplied to a fuel cell stack with moisture; a first cover connected to one end of the humidification module; and a second cover connected to the other end of the humidification module. The humidification module may include: an intermediate shell having opposite ends opened; and at least one cartridge including a plurality of hollow fiber membranes. The first cover may include a first gas inlet configured to allow a first gas supplied to the intermediate shell to be introduced therethrough and a first interface communicating with the hollow fiber membranes, the first interface being configured to allow a second gas to be introduced therethrough or discharged therethrough. The intermediate shell may include an intermediate body configured to accommodate the cartridge and a bypass unit configured to allow the first gas introduced through the first gas inlet to bypass so as to flow toward the cartridge accommodated in the intermediate body. The bypass unit may protrude from the intermediate body at a position where the bypass unit overlaps with the cartridge accommodated in the intermediate body.

[0022] Beneficial Effects

[0023] The present disclosure can reduce the risk of damage or destruction of the hollow fiber membrane due to gas pressure. Therefore, the present disclosure can extend the service life and reduce maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic exploded perspective view of a conventional humidifier for a fuel cell.

[0025] Figure 2 is a schematic exploded perspective view of a humidifier for a fuel cell according to the present disclosure.

[0026] Figure 3 It is shown along Figure 2 FIG. 2 is a schematic exploded cross-sectional view of a humidifier for a fuel cell according to the present disclosure, taken along line II.

[0027] Figure 4 It is shown along Figure 2 A schematic connection cross-sectional view of a humidifier for a fuel cell according to the present disclosure, taken along line II.

[0028] Figure 5 and Figure 6 is a schematic plan view of a cylinder of a humidifier for a fuel cell according to the present disclosure.

[0029] Figure 7 is a schematic side sectional view showing the direct flow of the first gas introduced into the intermediate housing through the first gas inlet toward the cylinder.

[0030] Figure 8 is a schematic perspective view of a humidifier for a fuel cell including a bypass unit according to the present disclosure.

[0031] Fig. 9 It is along Figure 8 Schematic partial sectional view taken along line II-II.

[0032] Fig.10 is a schematic exploded perspective view of an intermediate housing having a bypass unit and a first cover having a first gas inlet in a humidifier for a fuel cell according to the present disclosure.

[0033] Fig.11 It is the experimental result of measuring the humidification efficiency and the shell pressure difference by changing the cross-sectional area of ​​the first bypass channel. DETAILED DESCRIPTION

[0034] Hereinafter, an embodiment of a humidifier for a fuel cell according to the present disclosure will be described in detail with reference to the accompanying drawings. The intermediate housing of the humidifier for a fuel cell according to the present disclosure may be included in the humidifier for a fuel cell according to the present disclosure. Therefore, when describing the humidifier for a fuel cell according to the present disclosure, the barrel of the humidifier for a fuel cell according to the present disclosure will also be described. At the same time, Figure 7 In , two parallel curves are ellipsis lines. In addition, Figure 7 and Fig. 9 In the figure, the hollow fiber membranes are simply shown only by hatching, and the inner housing is omitted.

[0035] Reference Figures 2 to 4 According to the present disclosure, a humidifier 1 for a fuel cell is configured to humidify dry gas supplied to a fuel cell stack (not shown) using wet gas. The wet gas can be discharged from the fuel cell stack. The dry gas can be a fuel gas or air. The dry gas can be humidified by the wet gas and can be supplied to the fuel cell stack. According to the present disclosure, a humidifier 1 for a fuel cell includes: a humidification module 2 configured to humidify dry gas, a first cover 3 connected to one end of the humidification module 2, and a second cover 4 connected to the other end of the humidification module 2.

[0036] Reference Figures 2 to 4 , the humidification module 2 humidifies the dry gas. The first cover 3 can be connected to one end of the humidification module 2. The second cover 4 can be connected to the other end of the humidification module 2. The humidification module 2 can supply humidified dry gas to the fuel cell stack using the first gas and the second gas. When the first gas is dry gas, the second gas can be wet gas. In this case, the first gas can be humidified by the second gas and then can be supplied to the fuel cell stack. When the first gas is wet gas, the second gas can be dry gas. In this case, the second gas can be humidified by the first gas and then can be supplied to the fuel cell stack.

[0037] The humidification module 2 includes an intermediate housing 21 and at least one cylinder 22 .

[0038] The barrel 22 is connected to the intermediate housing 21. The barrel 22 may be disposed in the intermediate housing 21. The opposite ends of the intermediate housing 21 are open. In this case, a receiving hole 211 may be formed in the intermediate housing 21. The receiving hole 211 may be formed to extend through the intermediate housing 21 in the first axis direction (X axis direction). At least one barrel 22 may be disposed in the receiving hole 211.

[0039] The intermediate housing 21 may include an intermediate body 210. The barrel 22 is accommodated in the intermediate body 210. The barrel 22 may be disposed in the intermediate body 210 so as to be accommodated in the intermediate body 210. At least one barrel 22 may be accommodated in the intermediate body 210. A receiving hole 211 may be formed through the intermediate body 210 in a first axis direction (X axis direction).

[0040] The first gas inlet 30 and the first gas outlet 212 may be formed in the intermediate housing 21. The first gas inlet 30 may introduce the first gas into the intermediate housing 21. The first gas outlet 212 may discharge the first gas from the intermediate housing 21. In this case, the first gas outlet 212 may discharge the first gas discharged from the cylinder 22 to the outside of the intermediate body 210.

[0041] The barrel 22 is disposed in the intermediate housing 21. The barrel 22 includes a plurality of hollow fiber membranes 221. The hollow fiber membranes 221 can be connected to the barrel 22 for modularization. Therefore, the hollow fiber membranes 221 can be installed in the intermediate housing 21 by a process of connecting the barrel 22 to the intermediate housing 21. Therefore, in the humidifier 1 for a fuel cell according to the present disclosure, the ease of installation, separation and replacement of the hollow fiber membranes 221 can be improved.

[0042] The barrel 22 may include an inner shell 222 .

[0043] The inner housing 222 has openings formed at opposite ends and accommodates the hollow fiber membranes 221. The hollow fiber membranes 221 may be disposed in the inner housing 222 for modularization. Each hollow fiber membrane 221 may include a polymer membrane made of a polysulfone resin, a polyethersulfone resin, a sulfonated polysulfone resin, a polyvinylidene fluoride (PVDF) resin, a polyacrylonitrile (PAN) resin, a polyimide resin, a polyamideimide resin, a polyesterimide resin, or a mixture of two or more thereof.

[0044] The cylinder 22 may include a first fixing layer 223. The first fixing layer 223 is configured to fix one end of each hollow fiber membrane 221. The first fixing layer 223 may close an opening formed in one end of the inner shell 222. In this case, the first fixing layer 223 may be formed so as not to block the hollow of the hollow fiber membrane 221. The first fixing layer 223 may be formed by hardening a liquid resin such as a liquid polyurethane resin through a casting process. A portion of the first fixing layer 223 may be located in the inner shell 222, and the remaining portion of the first fixing layer may protrude outward from the inner shell 222. The first fixing layer 223 may fix one end of each hollow fiber membrane 221 to the inner shell 222.

[0045] The cylinder 22 may include a second fixing layer 224. The second fixing layer 224 is configured to fix the other end of each hollow fiber membrane 221. The second fixing layer 224 may close an opening formed in the other end of the inner shell 222. In this case, the second fixing layer 224 may be formed so as not to block the hollow of the hollow fiber membrane 221. The second fixing layer 224 may be formed by hardening a liquid resin such as a liquid polyurethane resin through a casting process. A portion of the second fixing layer 224 may be located in the inner shell 222, and the remaining portion of the second fixing layer may protrude outward from the inner shell 222. The second fixing layer 224 may fix the other end of each hollow fiber membrane 221 to the inner shell 222. Since the second fixed layer 224 and the first fixed layer 223 are formed so as not to block the hollow of the hollow fiber membrane 221, the second gas can be supplied to the hollow of the hollow fiber membrane 221 without being obstructed by the second fixed layer 224 and the first fixed layer 223, and can be discharged from the hollow of the hollow fiber membrane 221 without being obstructed by the second fixed layer 224 and the first fixed layer 223.

[0046] Reference Figures 2 to 6 The cylinder 22 may include a second gas inlet 225 and a second gas outlet 226 .

[0047] The second gas inlet 225 is formed at the inner shell 222. The second gas inlet 225 may be formed at one side of the inner shell 222. One side of the inner shell 222 may be set to face any one side wall of the intermediate body 210. The second gas inlet 225 may introduce the first gas into the inner shell 222. The second gas inlet 225 may be formed through the inner shell 222. Figure 5 As shown in , the second gas inlet 225 can be implemented by a through hole formed through the inner shell 222. Figure 6As shown in , the second gas inlet 225 can be implemented by a plurality of through holes formed through the inner shell 222. In this case, the second gas inlet 225 may include a plurality of inflow windows 225a formed through different portions of the inner shell 222. The inflow windows 225a may be arranged spaced apart from each other in a first axis direction (X axis direction) and a second axis direction (Y axis direction) to form a matrix. The second axis direction (Y axis direction) is an axis direction perpendicular to the first axis direction (X axis direction).

[0048] The second gas outlet 226 is formed at the inner shell 222. The second gas outlet 226 may be formed at one side of the inner shell 222. The second gas outlet 226 may discharge the first gas from the inner shell 222. The second gas outlet 226 may be formed through the inner shell 222. Figure 5 As shown in , the second gas outlet 226 can be implemented by a through hole formed through the inner shell 222. Figure 6 As shown in , the second gas outlet 226 can be implemented by a plurality of through holes formed through the inner shell 222. In this case, the second gas outlet 226 may include a plurality of outflow windows 226a formed through different portions of the inner shell 222. The outflow windows 226a may be arranged spaced apart from each other in the first axis direction (X axis direction) and the second axis direction (Y axis direction) to form a matrix. The second gas outlet 226 and the second gas inlet 225 may be arranged spaced apart from each other in the first axis direction (X axis direction).

[0049] When the first gas is a wet gas, the first gas may be supplied to the space between the inner surface of the intermediate housing 21 and the outer surface of the cylinder 22 through the first gas inlet 30, may be supplied to the cylinder 22 through the second gas inlet 225, and may contact the outer surface of the hollow fiber membrane 221. In this process, the moisture contained in the first gas may be transmitted through the hollow fiber membrane 221 to humidify the second gas flowing along the hollow of the hollow fiber membrane 221. The humidified second gas may be discharged from the hollow fiber membrane 221 and then may be supplied to the fuel cell stack through the first cover 3 or the second cover 4. After humidifying the second gas, the first gas may be discharged to the space between the outer surface of the cylinder 22 and the inner surface of the intermediate housing 21 through the second gas outlet 226, and may be discharged from the intermediate housing 21 through the first gas outlet 212. In this case, the first gas may be exhaust gas discharged from the fuel cell stack.

[0050] When the first gas is a dry gas, the first gas can be supplied to the space between the inner surface of the intermediate housing 21 and the outer surface of the cylinder 22 through the first gas inlet 30, can be supplied to the cylinder 22 through the second gas inlet 225, and can contact the outer surface of the hollow fiber membrane 221. In this process, the moisture contained in the second gas flowing along the hollow of the hollow fiber membrane 221 can be transmitted through the hollow fiber membrane 221 to humidify the first gas introduced into the cylinder 22. The humidified first gas can be discharged to the space between the outer surface of the cylinder 22 and the inner surface of the intermediate housing 21 through the second gas outlet 226, can be discharged from the intermediate housing 21 through the first gas outlet 212, and can be supplied to the fuel cell stack. After humidifying the first gas, the second gas can be discharged from the hollow fiber membrane 221, and then can be discharged to the outside through the first cover 3 or the second cover 4. In this case, the second gas can be the exhaust gas discharged from the fuel cell stack.

[0051] The humidifying module 2 may include a plurality of pressing members 23 and 23 ′.

[0052] The compression members 23 and 23' form an airtight seal between the cylinder 22 and the intermediate housing 21 to prevent direct mixing between the first gas and the second gas. The compression members 23 and 23' can be inserted between the cylinder 22 and the intermediate housing 21. In this case, the cylinder 22 can be inserted through the first through holes 23a and 23a' formed in the compression members 23 and 23', respectively. The compression members 23 and 23' can be respectively arranged on the opposite sides of the cylinder 22. Although not shown, resin layers can be formed on the opposite sides of the cylinder 22 to replace the compression members 23 and 23'. Each resin layer can be formed by hardening a liquid polymer such as a liquid polyurethane resin using a casting method.

[0053] Reference Figures 2 to 4 , the first cover 3 is connected to one end of the humidification module 2. The space between the first cover 3 and the cylinder 22 can be isolated from the space between the cylinder 22 and the intermediate shell 21 in an airtight sealed state by a pressing member 23 or a resin layer. The first cover 3 may include a first interface 31. The first interface 31 is configured to allow the second gas to flow therethrough. The first interface 31 may be in communication with the hollow fiber membrane 221. Therefore, during the flow of the second gas between the first cover 3 and the hollow fiber membrane 221, the second gas can be introduced or discharged through the first interface 31.

[0054] Reference Figures 2 to 4, the second cover 4 is connected to the other end of the humidification module 2. The second cover 4 can be connected to the other end of the humidification module 2 so as to be spaced apart from the first cover 3 in the first axial direction (X-axis direction). The space between the second cover 4 and the cylinder 22 can be separated from the space between the cylinder 22 and the intermediate housing 21 by a pressing member 23' or a resin layer in an airtight sealed state. The second cover 4 may include a second interface 41. The second interface 41 is configured so that the second gas flows through it. The second interface 41 may be connected to the hollow fiber membrane 221. Therefore, during the flow of the second gas between the second cover 4 and the hollow fiber membrane 221, the second gas can be introduced or discharged through the second interface 41. When the second gas is introduced through the second interface 41, the second gas can be discharged through the first interface 31. In this case, the second gas can exchange moisture with the first gas while sequentially passing through the second cover 4, the hollow of the hollow fiber membrane 221 and the first cover 3. When the second gas is discharged through the second interface 41, the second gas can be introduced through the first interface 31. In this case, the second gas may exchange moisture with the first gas while sequentially passing through the first cover 3 , the hollow of the hollow fiber membrane 221 , and the second cover 4 .

[0055] Here, if Figure 7 As shown in , when the first gas introduced into the intermediate housing 21 through the first gas inlet 30 flows directly toward the cylinder 22, there is a risk of damaging or destroying the hollow fiber membrane 221 due to the pressure of the first gas. In order to avoid this, the humidifier 1 for a fuel cell according to the present disclosure may be implemented so that the first gas introduced through the first gas inlet 30 bypasses and flows toward the cylinder 22. To this end, in the humidifier 1 for a fuel cell according to the present disclosure, the intermediate housing 21 and the first cover 3 may be implemented as follows.

[0056] Reference Figures 2 to 10 , the intermediate housing 21 may include a bypass unit 213 .

[0057] The bypass unit 213 is configured to bypass the first gas introduced through the first gas inlet 30 so as to flow toward the cylinder 22 accommodated in the intermediate body 210. The bypass unit 213 may be connected to the inside of the first cover 3 and the inside of the intermediate body 210 so as to communicate therewith. In this case, the first cover 3 may include the first gas inlet 30. Therefore, the bypass unit 213 may be communicated with the first gas inlet 30 via the inside of the first cover 3. Therefore, the first gas introduced through the first gas inlet 30 may bypass along the bypass unit 213 and flow toward the cylinder 22 accommodated in the intermediate body 210.

[0058] As described above, the humidifier 1 for a fuel cell according to the present disclosure can reduce the pressure of the first gas flowing to the cylinder 22 by bypassing the first gas using the bypass unit 213. Therefore, the humidifier 1 for a fuel cell according to the present disclosure can reduce the risk of damaging or destroying the hollow fiber membrane 221 due to the pressure of the first gas introduced into the intermediate body 210. Therefore, the humidifier 1 for a fuel cell according to the present disclosure can extend the service life of the hollow fiber membrane 221, thereby reducing maintenance costs, operating costs, etc. In addition, the humidifier 1 for a fuel cell according to the present disclosure can extend the maintenance interval of the hollow fiber membrane 221, thereby helping to improve the operation rate of the fuel cell stack.

[0059] The bypass unit 213 may protrude from the middle body 210. Therefore, the humidifier 1 for a fuel cell according to the present disclosure may realize a flow channel for allowing the first gas to bypass the outside of the middle body 210 using the bypass unit 213. Therefore, the humidifier 1 for a fuel cell according to the present disclosure may be implemented so that the flow path for bypassing the first gas using the bypass unit 213 and the flow path of the first gas flowing between the inside of the middle body 210 and the outside of the cylinder 22 do not interfere with each other. Therefore, the humidifier 1 for a fuel cell according to the present disclosure is implemented so that the flow path of the first gas flowing between the inside of the middle body 210 and the outside of the cylinder 22 is not narrowed by the flow path for bypassing the first gas. Therefore, the humidifier 1 for a fuel cell according to the present disclosure may be implemented so that the pressure of the first gas applied to the hollow fiber membrane 221 can be reduced, and at the same time, the moisture exchange between the first gas and the second gas can be promoted.

[0060] The bypass unit 213 may be arranged to overlap with the cylinder 22 accommodated in the middle body 210. One end of the bypass unit 213 may be connected to the inside of the first cover 3 provided at one end of the middle body 210 so as to communicate therewith. The other end of the bypass unit 213 may be connected to the inside of the middle body 210 so as to communicate therewith. In this case, the other end of the bypass unit 213 may be arranged to overlap with the cylinder 22 accommodated in the middle body 210. Therefore, since the first end of the bypass unit 213 and the other end of the bypass unit 213 are arranged spaced apart from each other, the humidifier 1 for a fuel cell according to the present disclosure may be implemented so that as the first gas flows from one end of the bypass unit 213 to the other end of the bypass unit 213, the pressure of the first gas gradually decreases. In this case, as the flow rate of the first gas gradually decreases, the pressure applied by the first gas to the hollow fiber membrane 221 decreases. Therefore, the humidifier 1 for a fuel cell according to the present disclosure may be implemented so that the first gas can flow smoothly to the cylinder 22 via the bypass unit 213 by preventing the pressure of the first gas from changing suddenly. One end of the bypass unit 213 and the other end of the bypass unit 213 may be disposed at positions spaced apart from each other in the first axis direction (X-axis direction).

[0061] The bypass unit 213 may include a first bypass passage 213 a and a second bypass passage 213 b .

[0062] The first bypass channel 213a communicates with the inside of the first cover 3. The first bypass channel 213a may serve as an inlet through which the first gas is introduced into the bypass unit 213. The first bypass channel 213a may be formed through one end of the bypass unit 213.

[0063] The second bypass channel 213b communicates with the inside of the middle body 210. The second bypass channel 213b may serve as an outlet through which the first gas is discharged from the bypass unit 213. The second bypass channel 213b may be formed through the other end of the bypass unit 213.

[0064] The second bypass channel 213b and the first bypass channel 213a may be formed at different positions through the bypass unit 213 in different directions. Fig. 9 , the second bypass channel 213b may be formed through the bypass unit 213 in the downward direction from the other end of the bypass unit 213 to the middle body 210. In this case, the first bypass channel 213a may be formed through the bypass unit 213 in the left direction from one end of the bypass unit 213 to the first cover 3. Therefore, the first gas may be introduced through the first bypass channel 213a, may flow in the first axis direction (X axis direction), and may be discharged in the downward direction through the second bypass channel 213b, whereby the first gas may flow into the middle body 210. Therefore, the humidifier 1 for a fuel cell according to the present disclosure may be implemented so that the flow direction is changed during the flow from the bypass channel 213 to the inside of the middle body 210, thereby further reducing the pressure applied by the first gas to the hollow fiber membrane 221. At the same time, the second bypass channel 213b may be formed through the other end of the bypass unit 213 and the middle body 210. Therefore, the inside of the bypass unit 213 and the inside of the middle body 210 may be connected to each other so as to communicate with each other via the second bypass channel 213b. The bypass unit 213 and the middle body 210 may be integrally formed.

[0065] The intermediate housing 21 may include a first intermediate passage 210 a .

[0066] The first intermediate channel 210a is communicated with the inside of the first cover 3. The first intermediate channel 210a may serve as a channel for introducing or exhausting the second gas between the inside of the first cover 3 and the hollow fiber membranes 221. The first intermediate channel 210a may be formed through one end of the intermediate body 210. The first intermediate channel 210a may correspond to one end of the receiving hole 211. One end of each hollow fiber membrane 221 fixed by the first fixing layer 223 may be disposed in the first intermediate channel 210a.

[0067] The intermediate housing 21 may include a second intermediate passage (not shown).

[0068] The second intermediate channel may serve as a channel for introducing or exhausting the second gas between the inside of the second cover 4 and the hollow fiber membranes 221. The second intermediate channel may be formed through the other end of the intermediate body 210. The second intermediate channel may correspond to the other end of the receiving hole 211. The other end of each hollow fiber membrane 221 fixed by the second fixing layer 224 may be disposed in the second intermediate channel.

[0069] Here, the first intermediate channel 210a and the first bypass channel 213a can each be implemented to have the following cross-sectional area. In this case, the cross-sectional area refers to the area through which the first intermediate channel 210a and the first bypass channel 213a can each allow fluid to pass. The cross-sectional area of ​​each of the first intermediate channel 210a and the first bypass channel 213a is the area of ​​the cross section in the up-down direction (Z-axis direction). The up-down direction (Z-axis direction) can be the axial direction perpendicular to the first axis direction (X-axis direction) and the second axis direction (Y-axis direction). The up-down direction (Z-axis direction) can also be the axial direction parallel to the second axis direction (Y-axis direction). In this case, the cylinder 22 can be arranged to face the direction other than the direction in which the second gas inlet 225 and the second gas outlet 226 face the second bypass channel 213b. The first intermediate channel 210a and the first bypass channel 213a can be arranged spaced apart from each other in the up-down direction (Z-axis direction).

[0070] First, the cross-sectional area of ​​the first intermediate channel 210a can be implemented to be larger than the cross-sectional area of ​​the first bypass channel 213a. In Comparative Example 1, the cross-sectional area of ​​the first bypass channel 213a is implemented to be larger than the cross-sectional area of ​​the first intermediate channel 210a or equal to the cross-sectional area of ​​the first intermediate channel 210a, and the flow rate of the first gas introduced into the bypass unit 213 via the first bypass channel 213a becomes too low. Therefore, in Comparative Example 1, the first gas cannot be delivered to the relatively inwardly arranged hollow fiber membranes 221 in the hollow fiber membranes 221 in the cylinder 22, thereby reducing the humidification efficiency. In order to prevent this, the humidifier 1 for a fuel cell according to the present disclosure can be implemented so that the cross-sectional area of ​​the first bypass channel 213a is smaller than the cross-sectional area of ​​the first intermediate channel 210a. Therefore, when compared with Comparative Example 1, the humidifier 1 for a fuel cell according to the present disclosure can increase the flow rate of the first gas introduced into the bypass unit 213 via the first bypass channel 213a, thereby increasing the proportion of the hollow fiber membranes 221 participating in humidification in the hollow fiber membranes 221 in the cylinder 22. Therefore, the humidifier 1 for a fuel cell according to the present disclosure can have a humidification efficiency that is more improved than that of Comparative Example 1.

[0071] Next, assuming that the cross-sectional area of ​​the first intermediate channel 210a is 1, the cross-sectional area of ​​the first bypass channel 213a can be implemented as 0.1 to 0.45. That is, the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a can be 10% to 45%. Therefore, the humidifier 1 for a fuel cell according to the present disclosure can be implemented to have a humidification efficiency and a shell pressure difference within a predetermined range. The shell pressure difference is related to the pressure acting on the inside of the intermediate shell 21 and the inside of the cylinder 22 during the process in which the first gas is introduced through the first gas inlet 30 and discharged through the first gas outlet 212. If the shell pressure difference is too high, there is a risk of damaging or destroying the intermediate shell 21, the cylinder 22 and the hollow fiber membrane 221. If the shell pressure difference is too low, the residence time of the first gas in the intermediate shell 21 and the cylinder 22 will be too short, resulting in low humidification efficiency.

[0072] Reference Figures 2 to 11 ,Depend on Fig.11 It can be seen from the experimental results that when the cross-sectional area of ​​the first bypass channel 213a is 10% to 45% of the cross-sectional area of ​​the first intermediate channel 210a, the humidifier is implemented to have a humidification efficiency and a shell pressure difference within a predetermined range. Fig.11 These are experimental results of measuring the humidification efficiency and the case pressure difference by changing only the cross-sectional area of ​​the first bypass channel 213 a without changing the cross-sectional areas of the first intermediate channel 210 a and the second bypass channel 213 b . Fig.11 All experimental results in are the measurement results of humidification efficiency and shell pressure difference when the same flow rate of the first gas is supplied through the first gas inlet 30 and the cross-sectional area of ​​the second bypass channel 213a is implemented as 60% of the cross-sectional area of ​​the first intermediate channel 210a. Fig.11 Here, the cross-sectional area ratio refers to the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a.

[0073] Depend on Fig.11It can be seen that Example 1 is implemented so that the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is 10%, thereby, the humidification efficiency is 32RH% and the shell pressure difference is 21kPa. Example 2 is implemented so that the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is 30%, thereby, the humidification efficiency is 30RH% and the shell pressure difference is 19kPa. Example 3 is implemented so that the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is 10%, thereby, the humidification efficiency is 32RH% and the shell pressure difference is 21kPa. Therefore, it can be seen that Examples 1 to 3 are implemented so that the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is 10% to 45%, thereby, the humidification efficiency is 30 to 32RH% and the shell pressure difference is 18 to 21kPa.

[0074] Comparative Example 2 is implemented so that the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is 8%, whereby the humidification efficiency is 31.5RH%, but the shell pressure difference is 32kPa, which is significantly higher than Examples 1 to 3. It can be seen from Comparative Example 2 that when the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is implemented to be less than 10%, the shell pressure difference increases significantly, which increases the risk of damaging the intermediate shell 21, the cylinder 22 and the hollow fiber membrane 221.

[0075] In addition, Comparative Example 3 is implemented so that the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is 47%, whereby the shell pressure difference is 17.5 kPa, but the humidification efficiency is 22 RH%, which is significantly lower than Examples 1 to 3. It can be seen from Comparative Example 3 that the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is implemented to be greater than 45%, and the humidification efficiency is significantly reduced.

[0076] Therefore, it can be seen that the humidifier 1 for fuel cells according to the present disclosure is implemented so that the ratio of the cross-sectional area of ​​the first bypass channel 213a to the cross-sectional area of ​​the first intermediate channel 210a is 10% to 45%, thereby, the humidification efficiency is 30 to 32RH%, and the shell pressure difference is 18 to 21kPa. Therefore, the humidifier 1 for fuel cells according to the present disclosure can reduce the risk of damage or destruction of the intermediate shell, the cylinder 22 and the hollow fiber membrane 221, while improving the humidification efficiency, thereby helping to further improve the performance of the fuel cell system.

[0077] At the same time, the cross-sectional area of ​​the second bypass channel 213b can be implemented as a cross-sectional area greater than that of the first bypass channel 213a. In this case, the cross-sectional area of ​​the second bypass channel 213b is the area of ​​the cross section in the first axis direction (X axis direction). In Comparative Example 4, the cross-sectional area of ​​the second bypass channel 213b is implemented as less than the cross-sectional area of ​​the first bypass channel 213a or equal to the cross-sectional area of ​​the first bypass channel 213a, and the flow rate of the first gas introduced into the intermediate body 210 via the second bypass channel 213b becomes too high. Therefore, in Comparative Example 4, the pressure of the first gas applied to the hollow fiber membrane 221 will increase excessively, thereby increasing the risk of damage or destruction of the hollow fiber membrane 221. In order to prevent this situation, the humidifier 1 for fuel cells according to the present disclosure can be implemented so that the cross-sectional area of ​​the second bypass channel 213b is greater than the cross-sectional area of ​​the first bypass channel 213a. Therefore, when compared with Comparative Example 4, the humidifier 1 for a fuel cell according to the present disclosure can reduce the flow rate of the first gas introduced into the intermediate body 210 via the second bypass channel 213 b , thereby reducing the risk of damaging or destroying the hollow fiber membrane 221 due to the pressure of the first gas.

[0078] At the same time, assuming that the cross-sectional area of ​​the first intermediate channel 210a is 1, the cross-sectional area of ​​the second bypass channel 213b can be implemented as 0.2 to 0.8. That is, the ratio of the cross-sectional area of ​​the second bypass channel 213b to the cross-sectional area of ​​the first intermediate channel 210a can be 20% to 80%. Therefore, the humidifier 1 for a fuel cell according to the present disclosure can be implemented to have a humidification efficiency and a shell pressure difference within a predetermined range. In Comparative Example 5, the ratio of the cross-sectional area of ​​the second bypass channel 213b to the cross-sectional area of ​​the first intermediate channel 210a is implemented to be less than 20%, and the flow rate of the first gas introduced into the intermediate body 210 via the second bypass channel 213b becomes too high, thereby increasing the risk of damage or destruction of the hollow fiber membrane 221. In Comparative Example 6, the ratio of the cross-sectional area of ​​the second bypass channel 213b to the cross-sectional area of ​​the first intermediate channel 210a is implemented to be greater than 80%, and the flow rate of the first gas introduced into the intermediate body 210 via the second bypass channel 213b becomes too low, so the first gas cannot be delivered to the hollow fiber membrane 221 relatively disposed inwardly in the hollow fiber membrane 221, thereby reducing the humidification efficiency. In view of this, the ratio of the cross-sectional area of ​​the second bypass channel 213b to the cross-sectional area of ​​the first intermediate channel 210a is implemented to be 20% to 80%, and therefore, the humidifier 1 for fuel cells according to the present disclosure can reduce the risk of damage or destruction of the hollow fiber membrane 221 while improving the humidification efficiency, thereby contributing to further improving the performance of the fuel cell system. Even if the ratio of the cross-sectional area of ​​the second bypass channel 213b to the cross-sectional area of ​​the first intermediate channel 210a is 20% to 80%, the cross-sectional area of ​​the second bypass channel 213b can be implemented to be larger than the cross-sectional area of ​​the first bypass channel 213a.

[0079] Reference Figures 1 to 10 , the first cover 3 may include a first gas inlet 30 , a first communication channel 32 , a second communication channel 33 , and a partition portion 34 .

[0080] The first gas inlet 30 allows the first gas to be supplied to the intermediate housing 21 through it. The first gas inlet 30 may be connected to the first cover 3 so as to communicate with the interior of the first cover 3. When compared with the comparative example in which the first gas inlet 30 is arranged in the intermediate housing 21, the embodiment in which the first gas inlet 30 is arranged in the first cover 3 can reduce the distance between the first gas inlet 30 and the supply source (not shown) of the first gas. Therefore, the embodiment in which the first gas inlet 30 is arranged in the first cover 3 can reduce the length of the hose configured to connect the first gas inlet 30 and the supply source to each other, thereby contributing to the overall miniaturization of the fuel cell system. In addition, the embodiment in which the first gas inlet 30 is arranged in the first cover 3 can implement the hose configured to connect the first gas inlet 30 and the supply source to each other as a straight line, thereby contributing to the further miniaturization of the fuel cell system. The source may be a fuel cell stack. In this case, the first gas may be exhaust gas discharged from the fuel cell stack.

[0081] The first gas inlet 30 may protrude from the first cover 3. The first gas inlet 30 and the first interface 31 may protrude in the same direction. Fig.10 , the first gas inlet 30 and the first interface 31 may protrude from the upper surface of the first cover 3 in an upward direction. When the first gas is an exhaust gas discharged from the fuel cell stack and the second gas is a humidified gas supplied to the fuel cell stack, both the first gas inlet 30 and the first interface 31 may be connected to the fuel cell stack. In this case, the first interface 31 may supply the second gas humidified by the first gas to the fuel cell stack. Therefore, the humidifier 1 for fuel cells according to the present disclosure may improve the ease of operation of connecting the first gas inlet 30 and the first interface 31 to the fuel cell stack. In addition, the humidifier 1 for fuel cells according to the present disclosure may reduce the length of the hose configured to connect the first gas inlet 30 and the first interface 31 to the fuel cell stack, thereby contributing to further miniaturization of the fuel cell system. At the same time, the first gas outlet 212 may protrude from the intermediate body 210. The first gas outlet 212 and the first gas inlet 30 may protrude in the same direction. The first gas outlet 212 and the first gas inlet 30 may protrude in different directions.

[0082] The first communication channel 32 allows the first gas inlet 30 and the bypass unit 213 to communicate with each other therethrough. The first communication channel 32 may be provided in the first cover 3. The first communication channel 32 may be formed through one end of the first cover 3. One end of the first cover 3 is a portion facing one end of the intermediate housing 21. When the first cover 3 is connected to the intermediate housing 21, the first communication channel 32 may be connected to the first bypass channel 213a so as to communicate therewith. Therefore, the first gas may be introduced into the first communication channel 32 via the first gas inlet 30, and then may be introduced into the bypass unit 213 via the first bypass channel 213a. Subsequently, the first gas may flow along the inside of the bypass unit 213, and then may be introduced into the intermediate body 210 via the second bypass channel 213b.

[0083] The second communication channel 33 enables the first interface 31 and the hollow fiber membrane 221 to communicate with each other through it. The second communication channel 33 may be provided in the first cover 3. The second communication channel 33 may be formed through one end of the first cover 3. When the first cover 3 is connected to the intermediate housing 21, the second communication channel 33 may be continuously connected to the first intermediate channel 210a so as to communicate therewith. Therefore, the second gas may be introduced or discharged between the inside of the first cover 3 and the hollow fiber membrane 221 via the second communication channel 33 and the first intermediate channel 210a.

[0084] The partition part 34 spatially separates the first communication channel 32 and the second communication channel 33 from each other. The partition part 34 may be provided in the first cover 3 to separate the interior of the first cover into the first communication channel 32 and the second communication channel 33. Therefore, the partition part 34 may prevent the first gas and the second gas from mixing with each other in the first cover 3. Fig.10 , since the first communication channel 32 is disposed above the partition portion 34 and the second communication channel 33 is disposed below the partition portion 34, the first communication channel 32 and the second communication channel 33 may be spatially separated from each other by the partition portion 34. In this case, a portion of the first interface 31 may be disposed to pass through the first communication channel 32 and the partition portion 34, whereby the first interface 31 may be connected to the second communication channel 33 so as to communicate therewith.

[0085] The present disclosure described above is not limited to the above embodiments and drawings, and it is obvious to those skilled in the art that various substitutions, modifications and changes may be made without departing from the technical concept of the present disclosure.

Claims

1. An intermediate housing provided in a humidifier for a fuel cell, the humidifier comprising: a humidification module configured to humidify dry gas supplied to the fuel cell stack using wet gas; a first cover connected to one end of the humidification module; and a second cover connected to the other end of the humidification module, the intermediate housing comprising: an intermediate body configured to house at least one cartridge including a plurality of hollow fiber membranes; and a bypass unit configured to bypass the first gas introduced through the first gas inlet of the first cover so as to flow toward the cylinder accommodated in the intermediate body, The bypass unit protrudes from the intermediate body at a position where the bypass unit overlaps with the cylinder accommodated in the intermediate body.

2. The intermediate housing according to claim 1, wherein: A cross-sectional area of ​​a first intermediate passage formed through one end of the intermediate body is greater than a cross-sectional area of ​​a first bypass passage formed through one end of the bypass unit.

3. The intermediate housing according to claim 2, wherein: Assuming that the cross-sectional area of ​​the first intermediate channel is 1, the cross-sectional area of ​​the first bypass channel is 0.1 to 0.

45.

4. The intermediate housing according to claim 2, wherein: The bypass unit is provided with a second bypass passage communicating with the interior of the intermediate body, A cross-sectional area of ​​the second bypass channel is greater than a cross-sectional area of ​​the first bypass channel.

5. The intermediate housing according to claim 2, wherein: The bypass unit is provided with a second bypass passage communicating with the interior of the intermediate body, Assuming that the cross-sectional area of ​​the first intermediate channel is 1, the cross-sectional area of ​​the second bypass channel is 0.2 to 0.

8.

6. A humidifier for a fuel cell, the humidifier comprising: a humidification module configured to humidify dry gas supplied to the fuel cell stack using wet gas; a first cover connected to one end of the humidification module; and A second cover connected to the other end of the humidification module, wherein The humidification module comprises: an intermediate housing having opposite ends opened; and at least one cartridge including a plurality of hollow fiber membranes, The first cover includes a first gas inlet configured to allow a first gas supplied to the intermediate housing to be introduced therethrough and a first interface communicating with the hollow fiber membrane, the first interface being configured to allow a second gas to be introduced therethrough or discharged therethrough, The intermediate housing includes: an intermediate body configured to accommodate the cylinder; and a bypass unit configured to bypass the first gas introduced through the first gas inlet so as to flow toward the cylinder accommodated in the intermediate body, The bypass unit protrudes from the intermediate body at a position where the bypass unit overlaps with the cylinder accommodated in the intermediate body.

7. The humidifier according to claim 6, wherein: The first cover comprises: a first communication passage configured so that the first gas inlet and the bypass unit communicate with each other therethrough; a second communication channel configured so that the first port and the hollow fiber membrane communicate with each other therethrough; and The partition portion is configured to spatially separate the first communication channel and the second communication channel from each other.

8. The humidifier according to claim 7, wherein: The bypass unit includes a first bypass passage communicating with the first communication passage and a second bypass passage communicating with the interior of the intermediate body, The first bypass passage and the second bypass passage are formed through the bypass unit at different positions in different directions.

9. The humidifier according to claim 6, wherein: The first cover includes: a first communication channel configured so that the first gas inlet and the bypass unit communicate with each other through the first communication channel; and a second communication channel configured so that the first port and the hollow fiber membrane communicate with each other through the second communication channel, The bypass unit is provided at one end with a first bypass passage communicating with the first communicating passage, The intermediate body is provided at one end with a first intermediate channel communicating with the second communicating channel, A cross-sectional area of ​​the first intermediate channel is greater than a cross-sectional area of ​​the first bypass channel.

10. The humidifier according to claim 9, wherein: Assuming that the cross-sectional area of ​​the first intermediate channel is 1, the cross-sectional area of ​​the first bypass channel is 0.1 to 0.

45.

11. The humidifier according to claim 9, wherein: The bypass unit is provided with a second bypass passage communicating with the interior of the intermediate body, A cross-sectional area of ​​the second bypass channel is greater than a cross-sectional area of ​​the first bypass channel.

12. The humidifier according to claim 9, wherein: The bypass unit is provided with a second bypass passage communicating with the interior of the intermediate body, Assuming that the cross-sectional area of ​​the first intermediate channel is 1, the cross-sectional area of ​​the second bypass channel is 0.2 to 0.

8.

13. The humidifier according to claim 6, wherein: The intermediate housing includes a first gas outlet configured to allow the first gas exhausted from the cylinder to exit the intermediate body therethrough. The second cover includes a second interface in communication with the hollow fiber membrane.

14. The humidifier according to claim 13, wherein: The cylinder comprises: an inner casing in which the hollow fiber membrane is accommodated; a second gas inlet configured to allow the first gas to be introduced into the inner housing therethrough; and A second gas outlet is configured to allow the first gas to be discharged from the inner casing therethrough at a position spaced apart from the second gas inlet.

15. The humidifier according to claim 6, wherein: The first gas inlet and the first interface protrude in the same direction.

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