JP2010151339A - Method of manufacturing humidifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a humidifier manufacturable in a simple process while improving moisture exchange efficiency. <P>SOLUTION: The method of manufacturing the humidifier 1 in which a first fluid flows through the inside of a hollow fiber membrane and a second fluid of different humidity from the first fluid flows through the outside of the hollow fiber membrane 12, includes a first process for forming a flow velocity increasing section A for increasing the flow velocity of the second fluid by forming a restriction gradient in the axial direction of the hollow fiber membrane 11 on the inner surface of a case 20, and a second process for forming a dispersion section for dispersing the flow of the second fluid in a required direction, in an inflow part R1 of the second fluid in the case 20. The flow velocity improving section A in the first process and the dispersion section in the second process are formed at the same time by injection molding. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a humidifier that humidifies a fluid such as air supplied to a fuel cell or the like, and more particularly to a method of manufacturing a humidifier having a moisture-permeable hollow fiber membrane.

  In fuel cells such as polymer electrolyte fuel cells (PEFC), hydrogen (fuel gas) and oxygen-containing air (oxidant gas) are used to ensure the wet state of the electrolyte membrane that constitutes the fuel cell. ) Is required. Such a humidifier includes a hollow fiber membrane bundle formed by bundling hollow fiber membranes and a case for housing the hollow fiber membrane bundle. For example, air to be humidified toward the fuel cell (first fluid) is hollow fiber. The humid cathode offgas (second fluid) discharged from the cathode of the fuel cell passes through the inside of the membrane through the hollow fiber membrane (see, for example, Patent Documents 1 and 2).

JP-A-8-273687 JP 2004-311287 A

By the way, in order to improve the humidification efficiency of the humidifier, for example, it is preferable that the hollow fiber membrane bundle is formed to be long in the axial direction. However, when the hollow fiber membrane bundle is formed so as to be elongated in the axial direction, the cathode offgas flowing into the case from the offgas inflow portion hardly reaches the end of the case, and the region where the moisture exchange rate decreases There was a problem that it was easy to be formed at the end or the like.
In addition, there is a demand to improve the humidification efficiency by dispersing the cathode offgas flowing into the case from the offgas inflow portion into the case, and further, a humidifier having such a structure is manufactured by a simple process. There was a request to do.

  Then, this invention makes it a subject to provide the manufacturing method of the humidifier which can improve a water exchange efficiency and can be manufactured with a simple process.

  In order to achieve the above object, the present invention comprises a hollow fiber membrane bundle in which a plurality of hollow fiber membranes are bundled, and a cylindrical case that accommodates the hollow fiber membrane bundle, and the first fluid is the above-mentioned A method for producing a humidifier, wherein a second fluid having a humidity different from that of the first fluid flows through the hollow fiber membrane and flows outside the hollow fiber membrane in the case, wherein the hollow fiber is formed on the inner surface of the case. A first step of forming a flow velocity improving portion for improving the flow velocity of the second fluid by forming a throttle gradient in the axial direction of the membrane bundle, and the inflow portion of the second fluid in the case, A second step of forming a dispersion part that disperses the flow of two fluids in a necessary direction, and forming the flow velocity improvement part in the first step and the dispersion part in the second step together by injection molding It is characterized by that.

  According to such a humidifier manufacturing method, the flow velocity improving portion for improving the flow velocity of the second fluid is formed by forming the throttle gradient in the axial direction of the hollow fiber membrane bundle on the inner surface of the case. The flow rate improvement unit can improve the flow rate of the second fluid, and can effectively flow the second fluid along the hollow fiber membrane bundle. Therefore, moisture can be exchanged satisfactorily at the end portion in the case, and a humidifier with improved moisture exchange efficiency (high humidification efficiency) can be obtained.

  Further, the second step forms a dispersion part for dispersing the flow of the second fluid in the necessary direction in the inflow part of the second fluid in the case, so that the flow of the second fluid is changed to the axis of the hollow fiber membrane bundle. The humidifier can be dispersed along the direction, and the moisture exchange efficiency is improved.

  Moreover, since the flow velocity improvement part in the first step and the dispersion part in the second step are formed by injection molding, the manufacturing process can be reduced and the humidifier can be simplified. Therefore, the manufacturing cost of the humidifier can be reduced.

  Further, the present invention provides a fluid flow through which the second fluid flows by extending in the axial direction of the hollow fiber membrane bundle between the hollow fiber membrane bundle and the inner surface of the case by the injection molding. It is preferable that the portion is further formed.

  According to such a method of manufacturing a humidifier, the second fluid flows through the fluid flow portion and preferably flows in the axial direction of the hollow fiber membrane bundle, and is aligned along the axial direction of the hollow fiber membrane bundle. Thus, the second fluid can flow effectively. Therefore, moisture can be exchanged favorably even at the end portion in the case, and a humidifier with high humidification efficiency that further improves the moisture exchange efficiency can be obtained.

  Further, the present invention provides a displacement suppression that suppresses the outflow portion from being blocked by the displacement of the hollow fiber membrane bundle due to the thrust of the second fluid in the outflow portion of the second fluid in the case by the injection molding. It is preferable that the portion is further formed.

  According to such a method for manufacturing a humidifier, the displacement suppressing portion formed at the outflow portion of the second fluid suppresses the outflow portion from being blocked by the displacement of the hollow fiber membrane bundle due to the thrust of the second fluid. And the smooth outflow of the second fluid can be ensured. This promotes a smooth inflow of the second fluid on the inflow portion side, forms a smooth flow of the second fluid in the case, and a humidifier with improved moisture exchange efficiency is obtained.

  According to the present invention, it is an object of the present invention to provide a humidifier manufacturing method that can improve moisture exchange efficiency and can be manufactured by a simple process.

Hereinafter, embodiments of a method for manufacturing a humidifier according to the present invention will be described in detail with reference to the drawings as appropriate.
(First embodiment)
A first embodiment of the present invention will be described in detail with reference to FIGS.
First, a fuel cell system 100 in which a humidifier 1 manufactured by a method for manufacturing a humidifier according to this embodiment is incorporated will be described with reference to FIG. The fuel cell system 100 is mounted on a fuel cell vehicle (mobile body) (not shown), and includes a fuel cell stack 110, a hydrogen tank 121, a compressor 131, and a humidifier 1.

  The fuel cell stack 110 is a polymer electrolyte fuel cell (PEFC), and a plurality of single cells formed by sandwiching MEA (Membrane Electrode Assembly) with separators (not shown) are stacked. Has been configured. The MEA includes an electrolyte membrane (solid polymer membrane) and a cathode and an anode that sandwich the membrane. Each separator is formed with an anode channel 111 and a cathode channel 112 made of grooves and through holes.

  Then, hydrogen is supplied from the hydrogen tank 121 to the anode via the pipe 121a and the anode flow path 111, and oxygen-containing air is supplied from the compressor 131 that sucks outside air, and the pipe 131a, the humidifier 1, the pipe 131b, and the cathode. When supplied to the cathode via the flow path 112, an electrode reaction occurs on the anode and the catalyst (Pt or the like) contained in the cathode, and the fuel cell stack 110 is in a state capable of generating power.

  When the fuel cell stack 110 in a state where power can be generated in this way and an external load (for example, a driving motor (not shown)) are electrically connected and current is taken out, the fuel cell stack 110 generates power. Yes.

Further, the anode off gas discharged from the anode channel 111 is discharged to the diluter 132 through the pipe 121b. On the other hand, the cathode offgas discharged from the cathode channel 112 is discharged to the diluter 132 via the pipe 131c, the humidifier 1, and the pipe 132a, and the diluter 132 dilutes unconsumed hydrogen in the anode offgas. It has become. The diluted gas is discharged out of the vehicle via the pipe 132b.
The cathode off gas is humid due to water vapor (water) generated by the electrode reaction at the cathode. Moreover, since a part of the generated water vapor passes through the electrolyte membrane to the anode side, the anode off-gas is also humid.

  Next, the configuration of the humidifier 1 will be described with reference to FIGS. Here, for the sake of clarity, front, rear, left, right, upper, and lower are set with reference to FIG.

  The humidifier 1 is a high-humidity exhausted from the cathode channel 112 for air (first fluid) to be humidified from the compressor 131 (see FIG. 1, the same applies hereinafter) to the cathode channel 112 (refer to FIG. 1, the same applies hereinafter). Of the cathode off gas (second fluid). That is, the humidity of the air toward the cathode flow path 112 is different from the humidity of the cathode offgas, and the humidity of the cathode offgas is higher. The external shape of the humidifier 1 has a substantially rectangular parallelepiped shape as shown in FIG.

  As shown in FIG. 3A, the humidifier 1 includes a hollow fiber membrane bundle 11 and a square cylindrical case 20 that houses the hollow fiber membrane bundle 11. In addition, the axial direction (longitudinal direction) of the hollow fiber membrane bundle 11 and the case 20 coincides.

  The hollow fiber membrane bundle 11 is made of polyimide or the like, and a plurality of hollow fiber membranes 12 having moisture permeability (for example, 10 to 10,000) are bundled. Each hollow fiber membrane 12 swells and expands somewhat when it contains moisture.

  The case 20 is a rectangular tube-like container that accommodates the hollow fiber membrane bundle 11 therein. For example, the case 20 is made of a hard resin such as PC (polycarbonate) or PPO (polyphenylene oxide) and integrally formed by injection molding described later. Is formed.

The upper wall 21 and the lower wall 22 of the case 20 are formed with a constant thickness. The upper wall 21 is formed so as to be inclined downward from the front and rear ends toward the central portion in the axial direction of the hollow fiber membrane bundle 11, and the lower wall 22 is also formed in the center from the front and rear ends in the axial direction. It is formed in an upward slope toward the part. As a result, the upper wall surface (inner surface) 21A and the lower wall surface 22A of the case 20 have a central portion of the case 20 that is narrower than both end portions of the case 20, and a cross section in the ring cutting direction of the center portion at both end portions of the case 20 A flow velocity improving portion A that is smaller than the cross section in the ring cutting direction and has a throttle gradient in the axial direction is formed. That is, the central portion is squeezed, and the cathode offgas flows from an inflow portion R1 described later to the flow velocity improving portion A that is the squeezed portion to improve the flow velocity, and the cathode offgas has a momentum toward both front and rear ends. It is easy to flow.
In addition, in this embodiment, although the flow velocity improvement part A was formed by making the upper wall 21 and the lower wall 22 into inclined shape as mentioned above, the thickness of the upper wall 21 and the lower wall 22 is made into the hollow fiber membrane bundle 11 It may be formed so as to have a throttle gradient so that the inner surface of the case 20 becomes an inclined surface by gradually changing in the axial direction, thereby forming the flow velocity improving portion A as described above.

In the present embodiment, the cathode offgas inflow portion R1 is formed at the center of the upper surface of the case 20 in the axial direction, and the cathode offgas outflow portion R2 is formed at the center of the lower surface of the case 20 immediately below the inflow portion R1. Yes. That is, the inflow portion R1 and the outflow portion R2 are formed above and below the flow velocity improving portion A formed in the center portion of the case 20.
The inflow portion R1 has a step wall 21a in which the central portion of the upper wall 21 is lowered by one step, and the step wall 21a and the upper wall 21 are utilized by using a step difference due to the height difference between the step wall 21a and the upper wall 21. Between the two, openings 21b and 21b functioning as inflow ports communicating with the inside of the case 20 are formed.
In the present embodiment, the stepped wall 21a and the openings 21b and 21b constitute a dispersion portion that disperses the flow of the cathode off gas flowing into the inflow portion R1 in a necessary direction in the case 20. The stepped wall 21a has a flat upper surface, and the cathode off-gas flows from the pipe 131c (see FIG. 1) in a direction substantially orthogonal to the upper surface.
Here, the periphery of the inflow portion R1 is surrounded by a peripheral wall constituting an introduction port (not shown), and the cathode offgas flowing in the direction orthogonal to the step wall 21a is, as shown in FIG. The flow direction of the stepped wall 21a is changed to flow into the case 20 through the openings 21b and 21b. In other words, the step wall 21a serves as a baffle plate that disperses the cathode off-gas flow in a necessary direction.
The necessary direction is a direction in which the cathode off-gas moisture is exchanged favorably in the case 20, and specifically, is a direction mainly from the center of the case 20 toward both front and rear ends.

Here, in the case 20, as shown in FIG. 3A, there is a hollow space between the upper surface of the hollow fiber membrane bundle 11 and the inner surface of the upper wall 21 arranged as described later in the case 20. Fluid flow portions S1 and S1 (gap) extending in the axial direction of the yarn membrane bundle 11 are formed. The fluid flow parts S1 and S1 communicate with the openings 21b and 21b, respectively, so that the cathode off-gas flowing into the case 20 from the openings 21b and 21b passes through the fluid flow parts S1 and S1. 20 is distributed in the flow.
In addition, an inner wall (not shown) is formed along the upper wall surface 21A of the upper wall 21, and an inner wall (not shown) is formed along the lower wall surface 22A of the lower wall 22, and a fluid flow portion is provided therebetween. S1 and S1 may be provided. In this case, each inner wall is formed with cathode gas flow holes, slits, and the like so as to allow the cathode gas to flow from the fluid flow portions S1 and S1 into the hollow fiber membrane bundle 11. .

  Further, the lower surface of the stepped wall 21 a gently bulges downward in a triangular shape in cross section to constitute a part of the flow velocity improving portion A described above, and forms a throttle gradient in the axial direction of the case 20.

On the other hand, the outflow portion R2 has a step wall 22a in which the central portion of the lower wall 22 is raised by one step, and between the step wall 22a and the lower wall 22, it passes into the case 20 and exhausts the cathode off gas. Openings 22b and 22b functioning as outlets are formed.
In the present embodiment, the displacement of the hollow fiber membrane bundle 11 due to the thrust of the cathode offgas (force that the cathode offgas presses the hollow fiber membrane bundle 11 downward) is caused by the step wall 22a with the central portion of the lower wall 22 raised one step ( The displacement suppression part which suppresses that the outflow part R2 obstruct | occludes by the displacement to the outflow part R2 is formed.
The step wall 22a has a shape in which the above-described step wall 21a is turned upside down, and its upper surface gently bulges upward in a triangular shape to form a part of the flow velocity improving portion A, and the case An aperture gradient is formed in 20 axial directions. That is, the step wall 22a has both a function as a displacement suppressing portion and a function constituting a part of the flow velocity improving portion A.

  Further, in the case 20, it extends in the axial direction of the hollow fiber membrane bundle 11 between the lower surface of the hollow fiber membrane bundle 11 and the inner surface of the lower wall 22 arranged as described later in the case 20. Fluid flow portions S2 and S2 (gap) are formed. The fluid flow portions S2 and S2 communicate with the openings 22b and 22b, respectively. As a result, the cathode offgas flowing outside the hollow fiber membrane 12 in the case 20 flows into the fluid flow portions S2 and S2. Are discharged to the outflow portion R2 through the openings 22b and 22b.

Next, the front side and the rear side of the hollow fiber membrane bundle 11 are fixed to the case 20 via potting portions 13 and 13 (sealing portions) formed of epoxy resin or the like. And the axial direction center part of the hollow fiber membrane bundle 11 is restrict | squeezed so that it may be pinched | interposed from the upper and lower sides by the above-mentioned level | step difference wall 21a and the level | step difference wall 22a. That is, the hollow fiber membrane bundle 11 is arranged in the case 20 so that the center portion thereof is narrowed in the vertical direction and expands in the vertical direction toward the front side and the rear side.
The gap between the fluid flow passage S1 is set by the step between the upper wall 21 and the step wall 21a and the thickness in the height direction of the potting portion 13, and the step between the lower wall 22 and the step wall 22a. And the clearance gap between the fluid flow-through part S2 is set by the thickness of the potting part 13 in the height direction.

A front cap 14 is attached to the front portion of the case 20, and a rear cap 15 is attached to the rear portion of the case 20.
3B, the air from the compressor 131 flows into the hollow fiber membranes 12 from the air inflow portion 15a of the rear cap 15 through the rear cap 15 and into the hollow fiber membranes 12. After flowing through the inside toward the front, the air flows through the front cap 14 and flows out from the air outflow portion 14a of the front cap 14 to the outside (pipe 131b, FIG. 1).

  On the other hand, as shown in FIG. 3 (b), the cathode off-gas flows downward from the inflow portion R1 of the case 20, that is, toward the upper surface of the step wall 21a. And flow into the fluid flow-through portions S1 and S1 in the case 20 from the openings 21b and 21b. Then, the sufficiently dispersed cathode off gas flows into the entire upper surface of the hollow fiber membrane bundle 11 from the fluid flow portions S1 and S1, and flows downward in the case 20 outside the hollow fiber membrane 12. After that, it flows out to the fluid flow parts S2, S2. Thereafter, the cathode off-gas flows out from the fluid flow-through portions S2 and S2 to the outflow portion R2 through the openings 22b and 22b, and flows out from the outflow portion R2 to the outside (pipe 132a, FIG. 1).

That is, it is configured such that air toward the fuel cell stack 110 to be humidified flows through the hollow fiber membrane 12 forward, and a humid cathode off gas flows from the center of the case 20 toward both front and rear ends. Yes.
And as described above, the inner surface of the case 20 has a flow velocity improving portion A having a drawing gradient in the axial direction of the hollow fiber membrane bundle 11 from the central portion of the case 20 toward both ends of the case 20. Therefore, the cathode off-gas that has flowed in from the inflow portion R1 has its flow velocity improved by the flow velocity improving portion A and flows to both ends.
On the other hand, the cathode off gas is dispersed in the front-rear direction by the step wall 21a, and is prevented from flowing in a short circuit from the inflow portion R1 toward the outflow portion R2. As a result, the cathode off gas can be spread throughout the hollow fiber membrane bundle 11.

  According to the humidifier 1 having the case 20 formed in this way, a flow rate improving unit for improving the flow rate of the cathode offgas by forming a throttle gradient in the axial direction of the hollow fiber membrane bundle 11 on the inner surface of the case 20. Since A is formed, the flow rate of the cathode off gas can be improved by the flow rate improving portion A, and the cathode off gas is effectively applied from the center portion of the case 20 toward the front and rear end portions along the hollow fiber membrane bundle 11. Can be shed. Therefore, moisture can be exchanged satisfactorily at the front end and rear end in the case 20, and the humidifier 1 with improved moisture exchange efficiency can be obtained.

  Further, since the cathode offgas inflow portion R1 in the case 20 is formed with a dispersion portion composed of a step wall 21a and openings 21b and 21b for dispersing the cathode offgas flow in a necessary direction, the cathode offgas is dispersed. It is possible to flow effectively in the direction along the hollow fiber membrane bundle 11 at the part, that is, from the center part of the case 20 toward both front and rear ends. Thereby, the humidifier 1 which improved the water exchange efficiency is obtained.

  Further, since the fluid flow-through portion S1 is formed in the case 20, the cathode off-gas flows through the fluid flow-through portion S1 and preferably flows in the axial direction of the hollow fiber membrane bundle 11, and the hollow fiber membrane bundle 11 The cathode off gas can be made to flow effectively along the line. Therefore, the moisture exchange can be performed satisfactorily at both the front and rear end portions in the case 20, and the humidifier 1 with further improved moisture exchange efficiency can be obtained.

  Further, since a step wall 22a as a displacement suppressing portion is formed in the outflow portion R2 of the case 20, the step wall 22a prevents the outflow portion R2 from being blocked by the displacement of the hollow fiber membrane bundle 11 due to the thrust of the cathode offgas. It is possible to prevent the cathode off gas from flowing out smoothly. This promotes a smooth inflow of the cathode offgas on the inflow portion R1 side, forms a smooth flow of the cathode offgas in the case 20, and the humidifier 1 with improved moisture exchange efficiency is obtained.

Next, with reference to FIG. 4, FIG. 5, the manufacturing method of case 20 of the humidifier 1 by injection molding is demonstrated.
4A to 4C are diagrams illustrating a method for manufacturing the case 20, and are schematic cross-sectional views in the longitudinal cross-sectional direction of the case 20. For each part of the case 20, refer to FIG.
First, as shown in FIG. 4 (a), the front and rear molds (movable molds) 40 and 41 for forming the sloped inner surface of the case 20 are slid in the direction of the arrows in the figure, respectively. It combines in the state which 41 facing parts contact | abut. 4B, the upper left mold (movable mold) 42 and the upper right mold (movable mold) 43 for forming the upper side including the upper wall 21 of the case 20 are replaced by the front and rear molds 40, 41. The lower left molds (movable molds) 44 and 45 for forming the lower side including the lower wall 22 of the case 20 are combined by moving upward and downward toward the front and rear molds 40 and 41.
Subsequently, as shown in FIG. 4C, the central upper mold (movable mold) 46 for forming the inflow portion R1 of the case 20 is moved downward toward the upper part of the contact portion of the front and rear molds 40 and 41. These lower and middle molds (movable molds) 47 for forming the outflow portion R2 of the case 20 are moved upward toward the lower part of the contact portion of the front and rear molds 40 and 41, and these molds are combined. Close.

Thereafter, as shown in FIG. 5A, for example, PC (polycarbonate) or PPO (polyphenylene) is passed through the gates 46a and 47a formed in the upper center mold (movable mold) 46 and the lower center mold (movable mold) 47. Resin such as oxide) is injected. As a result, the resin flows from the gates 46a and 47a to each part, and the step wall 21a (dispersing part), the step wall 22a (displacement suppressing part), the upper wall 21, and the lower wall 22 are formed at the same time, thereby forming the flow velocity improving part A. At the same time, the formation of the upper wall surface 21A of the fluid flow passage S1 due to the formation of the upper wall 21 and the formation of the lower wall surface 22A of the fluid flow passage S2 due to the formation of the lower wall 22 are simultaneously performed.
Then, when the resin is cooled, the mold is removed to obtain a case 20 as shown in FIG.

  Thus, since the flow velocity improvement part A and the dispersion part are formed by injection molding, the formation of the flow velocity improvement part A and the formation of the dispersion part can be performed in one process, and the manufacturing process is performed. It can be reduced and the manufacturing can be simplified. Therefore, the manufacturing cost of the humidifier 1 can be reduced.

  Further, since the fluid flow-through portion S1 is formed in the case 20 by injection molding, the cathode off-gas flows through the fluid flow-through portion S1 and preferably flows in the axial direction of the hollow fiber membrane bundle 11, and is hollow. The cathode off gas can be effectively flowed along the thread membrane bundle 11. Therefore, the moisture exchange can be performed satisfactorily at both the front and rear end portions in the case 20, and the humidifier 1 with further improved moisture exchange efficiency can be obtained.

  In addition, since the step wall 22a as a displacement suppressing portion is formed in the outflow portion R2 of the case 20 by the injection molding, the outflow portion R2 is formed by the displacement of the hollow fiber membrane bundle 11 due to the thrust of the cathode offgas by the step wall 22a. It is possible to suppress the clogging and to ensure a smooth outflow of the cathode off gas. This promotes a smooth inflow of the cathode offgas on the inflow portion R1 side, forms a smooth flow of the cathode offgas in the case 20, and the humidifier 1 with improved moisture exchange efficiency is obtained.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS.
The present embodiment is different from the first embodiment in that a flow velocity improving portion (a region in which the case 50 is narrowed) A ′ is formed on the front side of the case 50, and an inflow portion R1 ′ is above it. In addition to being formed, an outflow portion R2 ′ is formed on the rear side.

As shown in FIG. 6A, the inflow portion R1 ′ is located slightly rearward of the front end portion of the case 50, and the region below the inflow portion R1 ′ in the case 50 is the other in the axial direction. The flow velocity improving portion A ′ is formed by being narrowed compared to the region.
The upper wall 51 of the case 50 is formed in a downwardly inclined shape from the front and rear ends toward the inflow portion R1 ′ in the axial direction of the hollow fiber membrane bundle 11 in the case 50, and the lower wall 52 is formed in the axial direction. These are formed in an upwardly inclined shape from the front and rear ends toward directly below the inflow portion R1 ′. That is, the case 50 has a shape that is narrowed from the outflow portion R2 ′ side toward the inflow portion R1 ′ side. As a result, the inner surface of the case 50 has a throttle gradient in the axial direction of the hollow fiber membrane bundle 11, and the case 50 is throttled by the flow velocity improving portion A ′ and flows from the inflow portion R1 ′. The cathode off-gas flow rate is improved.

The inflow portion R1 ′ has a step wall 51a in which the central portion of the upper wall 51 is lowered by one step, and the step wall 51a and the upper wall are utilized by utilizing the step difference due to the height difference between the step wall 51a and the upper wall 51. An opening 51 b that functions as an inflow port communicating with the inside of the case 50 is formed between the opening 51 and the case 51. Thereby, the cathode off gas from the inflow portion R1 ′ flows into the case 50 through the opening 51b.
Further, a slit 51c is formed in the step wall 51a in the left-right direction of the case 50 (a direction orthogonal to the paper surface of FIG. 6A), and flows in a direction substantially orthogonal to the upper surface of the step wall 51a. The cathode off gas to be dispersed is dispersed in a necessary direction in the case 50 through the slit 51c. In this embodiment, the dispersion | distribution part is comprised by the level | step difference wall 51a, the opening 51b, and the slit 51c.
An opening 51b is similarly formed on the front side of the step wall 51a at the time of injection molding, which will be described later. However, when the hollow fiber membrane bundle 11 is accommodated in the case 50, it is closed by the potting portion 13. It has become.

  In the case 50, a fluid flow part S1 communicating with the opening 51b is formed to extend in the axial direction between the upper surface of the hollow fiber membrane bundle 11 and the inner surface of the upper wall 51, and the case 51 through the opening 51b. The cathode off-gas flowing into the gas 50 is dispersed and flows toward the rear of the case 50 through the fluid flow part S1.

On the other hand, the outflow portion R2 ′ is configured by forming a through hole 52a at the rear end portion of the lower wall 52, and the cathode off gas flowing outside the hollow fiber membrane 12 in the case 50 passes through the through hole 52a. It is supposed to be discharged. In the present embodiment, since the outflow portion R2 ′ is located at a position close to the potting portion 13 at the rear end portion, displacement on the rear side of the hollow fiber membrane bundle 11 is difficult to occur, and has been described in the first embodiment. Such a step wall 22a (see FIG. 2) is not provided. In addition, you may make it provide the thing equivalent to the level | step difference wall 22a suitably.
A slight gap S3 is formed between the lower surface of the hollow fiber membrane bundle 11 and the inner surface of the lower wall 52, and the lower surface of the hollow fiber membrane bundle 11 is prevented from sticking to the inner surface of the lower wall 52. Has been.

  The air from the compressor 131 flows into the hollow fiber membranes 12 from the air inflow portion 15a of the rear cap 15 through the rear cap 15 in the same manner as in the first embodiment. After flowing inward, the air flows through the front cap 14 and flows out from the air outflow portion 14a of the front cap 14 to the outside (pipe 131b, FIG. 1).

  On the other hand, as described above, a part of the cathode off gas flows into the case 50 through the slit 51c of the step wall 51a. Further, the cathode off-gas is dispersed backward by the step wall 51a and flows into the fluid flow passage S1 in the case 50 from the opening 51b, and flows into substantially the entire upper surface of the hollow fiber membrane bundle 11 from the fluid flow passage S1. . The cathode off gas that has flowed into the hollow fiber membrane bundle 11 flows outside the hollow fiber membrane 12 and downward in the case 50, and then from the outflow portion R2 (through hole 52a) to the outside (pipe 132a, FIG. 1). To leak.

  That is, it is configured such that the air toward the fuel cell stack 110 to be humidified flows through the hollow fiber membrane 12 forward and the humid cathode off-gas flows through the outside of the hollow fiber membrane 12 backward. . That is, the air flow direction and the cathode off-gas flow direction are opposite to each other, so that the air is efficiently humidified.

  As described above, the inner surface of the case 50 has a narrowing gradient in the axial direction of the hollow fiber membrane bundle 11 from the front part of the case 50 toward the rear part of the case 50, and the flow velocity at the front end part. Since it has the improvement part A ′, the cathode offgas flowing from the inflow part R1 ′ at the front end of the case 50 flows into the hollow fiber membrane bundle 11 from the slit 51c and the fluid flow part S1. The flow velocity is improved by the narrowed flow velocity improvement portion A ′, and flows downward in the case 50 while flowing toward the rear side, and flows out from the outflow portion R2 ′. As a result, the cathode offgas preferably flows from the inflow portion R <b> 1 ′ toward the outflow portion R <b> 2 ′, and the cathode offgas can be spread over the entire hollow fiber membrane bundle 11.

  According to the humidifier 1 ′ having the case 50 formed in this way, the flow rate of the cathode off gas can be improved by the flow rate improving portion A ′, and the front end portion of the case 50 is aligned along the hollow fiber membrane bundle 11. The cathode off gas can be effectively flowed toward the rear end. Therefore, moisture exchange can be performed satisfactorily at the rear end of the case 50, and the humidifier 1 'with improved moisture exchange efficiency can be obtained.

  Further, the cathode off-gas can be effectively flowed in the direction along the hollow fiber membrane bundle 11 at the dispersion portion, that is, from the front end portion in the case 50 toward the rear end portion. Thereby, the humidifier 1 'with improved moisture exchange efficiency is obtained.

  Further, since the fluid flow-through portion S1 is formed in the case 50, the cathode off-gas flows through the fluid flow-through portion S1 and preferably flows in the axial direction of the hollow fiber membrane bundle 11, and the hollow fiber membrane bundle 11 The cathode off gas can be made to flow effectively along the line. Therefore, the moisture exchange can be satisfactorily performed at the rear end portion in the case 50, and the humidifier 1 'with further improved moisture exchange efficiency can be obtained.

Next, with reference to FIG. 7, the manufacturing method of case 50 of humidifier 1 'by injection molding is demonstrated.
7A to 7C are diagrams for explaining a method for manufacturing the case 50, and are schematic cross-sectional views in the longitudinal cross-sectional direction of the case 20. For each part of the case 50, refer to FIG. 6A as appropriate.
First, as shown in FIG. 7 (a), the front and rear molds (movable molds) 60 and 61 for forming the sloped inner surface of the case 50 are slid in the directions of the arrows in the figure, respectively. The end portions of 61 are combined in a contact state. 7B, the upper left mold (movable mold) 62 and the upper right mold (movable mold) 63 for forming the upper side including the upper wall 51 of the case 50 are replaced by the front and rear molds 60, 61. The lower mold (movable mold) 64 for forming the lower side including the lower wall 52 of the case 50 is moved upward and moved toward the front and rear molds 60 and 61 and combined.
Subsequently, as shown in FIG. 7C, the upper mold (movable mold) 65 for forming the inflow portion R1 ′ of the case 50 is moved downward toward the upper part of the contact portion of the front and rear molds 60 and 61. Combine and close these molds.

Thereafter, as shown in FIG. 8A, a resin such as PC (polycarbonate) or PPO (polyphenylene oxide) is injected through a gate 65a formed in the upper mold (movable mold) 65. As a result, the resin goes from the gate 65a to each part, the step wall 51a (dispersing part), the upper wall 51, and the lower wall 52 are formed at the same time to form the flow velocity improving part A ′ and the upper wall 51 is formed. Thus, formation of the upper wall surface 51A of the fluid flow passage S1 is performed at the same time.
Then, when the resin is cooled, the mold is removed to obtain a case 50 as shown in FIG.

  As described above, since the flow velocity improving portion A ′ and the dispersion portion are formed by injection molding, the formation of the flow velocity improving portion A ′ and the formation of the dispersion portion can be performed in one step, and the manufacturing process is completed. The number of processes can be reduced and the manufacturing can be simplified. Therefore, the manufacturing cost of the humidifier 1 'can be reduced.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, For example, it can change as follows in the range which does not deviate from the meaning of this invention.
In each of the above-described embodiments, the configuration in which air flows through the hollow fiber membrane 12 and the cathode off gas flows outside the hollow fiber membrane 12 is exemplified. However, the air flows outside the hollow fiber membrane 12 and has high humidity. The cathode off gas may flow through the hollow fiber membrane 12.

  Moreover, in 2nd Embodiment, although the flow direction of air and cathode off gas illustrated the reverse direction, the same direction may be sufficient.

Furthermore, in the first embodiment, the cathode offgas flows in from the upper wall 21 side of the humidifier 1 and flows out from the lower wall 22 side of the humidifier 1, but the inflow / outflow direction of the cathode offgas is this. It is not limited to this, For example, the structure which flows in from the downward direction and flows out upwards may be sufficient.
In the second embodiment, the cathode off gas flows in from the upper wall 51 side of the humidifier 1 ′ and flows out from the lower wall 52 side of the humidifier 1 ′. However, the present invention is not limited to this. For example, as shown in FIG. 9, a configuration may be adopted in which the gas flows in from below and flows out upward.

  Furthermore, the configuration in which the first fluid is air and the second fluid is cathode off-gas, that is, the configuration in which the first fluid and the second fluid are gases is exemplified. For example, the second fluid is water (liquid). It may be configured.

  In the first embodiment, the step wall 21a has a plate shape with a flat upper surface. However, as shown in the second embodiment, a slit through which the cathode off gas can flow may be formed. Further, a plurality of communication holes may be formed instead of the slits.

  In addition, the hollow fiber membrane bundle 11 and the cases 20 and 50 have a quadrangular cross-sectional shape in the ring cutting direction, but are not limited thereto, and are circular, elliptical, oval, and multi-sided cylindrical. Also good.

  In the above-described embodiment, the configuration in which the humidifier 1 exchanges moisture between the air and the cathode off gas and humidifies the air toward the fuel cell stack 110 is exemplified. However, for example, between the hydrogen and the anode off gas, A configuration may be adopted in which moisture is exchanged and the hydrogen toward the fuel cell stack 110 is humidified.

It is a figure which shows the structure of the fuel cell system to which the humidifier manufactured by the manufacturing method of the humidifier of 1st Embodiment is applied. It is a perspective view of the humidifier manufactured by the manufacturing method of the humidifier concerning a 1st embodiment (partially enlarged illustration). (A) is a sectional view of the humidifier, and (b) is a sectional view schematically showing the flow of the cathode offgas. (A)-(c) is explanatory drawing which similarly shows shaping | molding of the case of a humidifier. (A) is explanatory drawing which similarly shows shaping | molding of the case of a humidifier, (b) is sectional drawing of the case shape | molded similarly. (A) is sectional drawing of the humidifier manufactured by the manufacturing method of the humidifier which concerns on 2nd Embodiment, (b) is sectional drawing which showed the flow of the cathode off gas typically similarly. (A)-(c) is explanatory drawing which similarly shows shaping | molding of the case of a humidifier. (A) is explanatory drawing which similarly shows shaping | molding of the case of a humidifier, (b) is sectional drawing of the case shape | molded similarly. It is sectional drawing of the humidifier which shows another example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Humidifier 11 Hollow fiber membrane bundle 12 Hollow fiber membrane 13 Potting part 20, 50 Case 21, 51 Upper wall 21a, 51a Step wall 21b, 51b Opening 22, 52 Lower wall 22a, 52a Step wall 22b, 52b Opening 51c Slit 100 Fuel cell system 110 Fuel cell stack A, A ′ Flow velocity improving portion R1, R1 ′ Inflow portion R2, R2 ′ Outflow portion S1, S2 Fluid flow portion

Claims (3)

A hollow fiber membrane bundle formed by bundling a plurality of hollow fiber membranes;
A cylindrical case that accommodates the hollow fiber membrane bundle,
A method of manufacturing a humidifier, wherein a first fluid flows through the hollow fiber membrane, and a second fluid having a humidity different from that of the first fluid flows outside the hollow fiber membrane in the case,
A first step of forming a flow velocity improving portion for improving the flow velocity of the second fluid by forming a throttle gradient in the axial direction of the hollow fiber membrane bundle on the inner surface of the case;
Forming a dispersion part for dispersing the flow of the second fluid in a necessary direction at the inflow part of the second fluid in the case, and
The method for manufacturing a humidifier, wherein the flow velocity improving portion in the first step and the dispersing portion in the second step are formed together by injection molding. By the injection molding,
Between the hollow fiber membrane bundle and the inner surface of the case, a fluid flow portion that extends in the axial direction of the hollow fiber membrane bundle and through which the second fluid flows is further formed. The manufacturing method of the humidifier of claim | item 1. By the injection molding,
In the outflow part of the 2nd fluid in the case, the displacement control part which controls that the outflow part is obstructed by the displacement of the hollow fiber membrane bundle by the thrust of the 2nd fluid is further formed. The manufacturing method of the humidifier of Claim 1 or Claim 2.

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