JP2010107069A - Humidifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a humidifier properly humidifying fluid such as air supplied to a fuel cell and the like. <P>SOLUTION: This humidifier 1 has a cylindrical case 10 housing bundles 30 of hollow fiber membranes formed by bundling a plurality of hollow fiber membranes 30a, a first fluid flows in the hollow fiber membranes 30a, a second fluid having humidity different from that of the first fluid flows outside the hollow fiber membranes 30a in the case 10, and the second fluid flows toward an outer peripheral face of the bundles 30 of hollow fiber membranes from a second fluid inflow section. A plurality of receiving chambers 20 defined by partitioning walls and respectively receiving the bundles 30 of hollow yarn membranes are disposed in the case 10, and the plurality of receiving chambers 20 are filled with the hollow fiber membranes 30a with a uniform filling rate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a humidifier that humidifies a fluid such as air supplied to a fuel cell or the like, and more particularly to 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 to 3).

JP-A-6-132038 JP-A-8-273687 JP 2004-311287 A

By the way, a hollow fiber membrane formed of a porous material such as polyimide and a bundle of hollow fiber membranes in which the hollow fiber membrane is bundled are swollen and stretched when wetted with water vapor or the like.
Thus, when the hollow fiber membrane and the hollow fiber membrane bundle are stretched, a phenomenon occurs in which the hollow fiber membrane bundle (hollow fiber membrane) bends and moves in the case housing the hollow fiber membrane bundle. When such a phenomenon occurs, there is a possibility that the flow distribution in the hollow fiber membrane bundle is lowered and the humidification efficiency is lowered.

  Then, this invention makes it a subject to provide the humidifier which can humidify suitably.

  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 second fluid having a humidity different from that of the first fluid flows in the hollow fiber membrane and flows outside the hollow fiber membrane in the case, and the second fluid flows from the second fluid inflow portion of the case. A humidifier that flows toward the outer peripheral surface of the hollow fiber membrane bundle, wherein the housing includes a plurality of storage chambers that are partitioned by a partition wall and each store the hollow fiber membrane bundle. The chamber is filled with the hollow fiber membrane bundle at the same filling rate.

According to such a humidifier, the inside of the case has a plurality of storage chambers partitioned by a partition wall, and a hollow fiber membrane bundle (hollow fiber membrane) is filled at the same filling rate into each storage chamber. As a result, the first fluid and the second fluid flow evenly in the respective accommodation chambers, thereby improving the flow distribution.
Further, even if the hollow fiber membrane bundle swells and expands due to the flow of the first fluid and the second fluid, the hollow fiber membrane bundle is filled so as to be divided into a plurality of partitioned storage chambers. Since it is a configuration, for example, compared with the case where the hollow fiber membrane bundle is filled in a case that does not have such a partition, the movement due to the elongation of the hollow fiber membrane bundle can be effectively regulated by each accommodation chamber. In addition, it is possible to favorably maintain the flow distribution characteristics of the first fluid and the second fluid flowing in each storage chamber.
In addition, since the movement of the hollow fiber membrane bundle due to stretching can be effectively regulated, the load on the hollow fiber membrane due to stretching can be reduced, and inconveniences such as breakage of the hollow fiber membrane can be suitably prevented. Can do.
Further, since the movement of the hollow fiber membrane bundle due to the extension can be effectively controlled, for example, a part of the hollow fiber membranes moved by the extension sticks so as to block the inlet and outlet of the second fluid. Therefore, it is possible to prevent an increase in pressure loss.

  Further, in the present invention, it is preferable that the cross-sectional shapes in the ring cutting direction of the storage chamber and the hollow fiber membrane bundle are different from each other.

  According to such a humidifier, sticking of the hollow fiber membrane to the wall surface in the housing chamber can be suppressed, and good flow distribution can be suitably maintained.

  According to the present invention, a humidifier that can be suitably humidified is obtained.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
First, a fuel cell system 100 in which a humidifier 1 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.

  The fuel cell stack 110 in a state where power can be generated in this way and an external load (for example, a motor for traveling) are electrically connected, and when the current is taken out, the fuel cell stack 110 generates power.

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 humid cathode off-gas exhausted from the cathode channel 112 and air to be humidified (first fluid) from the compressor 131 (see FIG. 1) toward the cathode channel 112 (see FIG. 1, the same applies hereinafter). It is humidified with (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. 2, the humidifier 1 has a plurality of storage chambers 20 partitioned by a vertical wall 11 and a horizontal wall 12 serving as partition walls in a rectangular cylindrical case 10. The hollow fiber membrane bundle 30 is accommodated in 20. In addition, the axial direction (front-back direction) of the hollow fiber membrane bundle 30 and each accommodation chamber 20 is in agreement.
In the present embodiment, the inside of the case 10 is divided into a plurality (32 in total) of storage chambers 20 each consisting of four columns and eight rows, and each of the storage chambers 20 has a cathode offgas as described later. Is distributed and flows.
The number of stages and the number of rows of the storage chamber 20 are not limited to those described above, and can be set as appropriate.

The hollow fiber membrane bundle 30 is formed of polyimide or the like, and a plurality of hollow fiber membranes 30a having moisture permeability (for example, 10 to 10,000) are bundled. Are accommodated in the respective storage chambers 20.
In this embodiment, the cross-sectional shape in the ring cutting direction of each hollow fiber membrane bundle 30 (hollow fiber membrane 30a) is a circular shape (round shape). Here, the hollow fiber membrane bundle 30 can be formed so as to have a circular cross-sectional shape by appropriately bundling the hollow fiber membranes 30a.
Moreover, the hollow fiber membrane bundle 30 (hollow fiber membrane 30a) is filled with the same filling rate with respect to each accommodating chamber 20. That is, the number of bundles of the hollow fiber membrane bundles 30 is the same, and the filling rate with respect to the volume of the storage chamber 20 is the same in each storage chamber 20.
Each hollow fiber membrane 30a swells when it contains moisture and expands somewhat, but is configured to be filled as the hollow fiber membrane bundle 30 with respect to the plurality of compartmentalized storage chambers 20, respectively. Temporarily, the movement by the expansion | extension of the hollow fiber membrane bundle 30 can be controlled effectively compared with what was comprised so that the hollow fiber membrane bundle might be filled in the case in the case which is not divided in this way. In addition, since the cross-sectional shape in the ring cutting direction of the storage chamber 20 is a rectangular shape different from the cross-sectional shape of the hollow fiber membrane bundle 30 as will be described later, the storage chamber is formed by the expansion of the hollow fiber membrane bundle 30. Adherence to the inner surface of 20 can be suitably prevented.
The front side and the rear side of each hollow fiber membrane bundle 30 are fixed to the case 10 (accommodating chamber 20) via a potting portion 31 (see FIG. 3, sealing portion) formed of an epoxy resin or the like.

As described above, the case 10 is a rectangular tube-shaped container having a plurality of storage chambers 20 defined therein, and is integrally formed from a hard resin such as PC (polycarbonate) or PPO (polyphenylene oxide). Is formed.
As described above, the plurality of storage chambers 20 formed in the case 10 have a rectangular shape that is different from the cross-sectional shape (circular shape) of the hollow fiber membrane bundle 30, and as shown in FIG. A slight gap G is formed between the outer peripheral surface of the bundle 30 and the inner surface of the storage chamber 20.
Further, as shown in FIG. 4, an inlet for injecting a cathode off gas is provided at the front side of each storage chamber 20 in accordance with a mounting position of an inflow side manifold 15 a (second fluid inflow portion) described later. 21 is formed so that it may penetrate the horizontal wall 12 which partitions each storage chamber 20 to an up-down direction, respectively.
On the other hand, as shown in FIG. 6, on the rear side of each storage chamber 20, an outlet 22 for injecting a cathode off gas partitions each storage chamber 20 in accordance with a mounting position of an outflow side manifold 16 a described later. Each is formed so as to penetrate the horizontal wall 12 in the vertical direction.
Further, as shown in FIGS. 2 and 3, a front cap 13 is attached to the front side of the case 10, and a rear cap 14 is attached to the rear side of the case 10.

  Then, air (air to be humidified) from the compressor 131 (see FIG. 1) passes through the rear cap 14 from the air inflow portion 14a of the rear cap 14 and in each hollow fiber membrane 30a of each hollow fiber membrane bundle 30. And flows through the respective hollow fiber membranes 30a in the respective storage chambers 20 toward the front, and then passes through the front cap 13 from the air outflow portion 13a of the front cap 13 to the outside (pipe 131b, FIG. 1)).

On the other hand, the cathode off-gas flows downward from the off-gas inflow portion 15b of the inflow side manifold 15a provided on the front side of the top wall portion 15 (a part of the peripheral wall portion) of the case 10 having a square cylindrical shape. As shown in FIG. 4, the liquid is distributed in the left-right direction in the inflow side manifold 15 a and flows into the storage chambers 20 through the inflow ports 21 formed in the lateral walls 12 that partition the storage chambers 20.
The cathode off gas that has flowed in this way flows outside the hollow fiber membranes 30a of the hollow fiber membrane bundles 30 and flows backward in the respective accommodating chambers 20 (see FIG. 3), and then the bottom wall portion of the case 10 16 flows out to the outside (pipe 132a, see FIG. 1) through the outflow side manifold 16a (see FIG. 6).
As shown in FIG. 3, the outflow side manifold 16 a is provided on the rear side of the bottom wall portion 16 of the case 10, and as shown in FIG. 6, the outflow port formed in the horizontal wall 12 that partitions each storage chamber 20. The cathode off-gas that has flowed out of the hollow fiber membranes 30a of the hollow fiber membrane bundles 30 accommodated in the respective accommodating chambers 20 is collected and discharged through 22.

  That is, the air to be humidified toward the fuel cell stack 110 flows forward through the hollow fiber membrane 30a, and the humid cathode offgas flows backward through the hollow fiber membrane 30a. Yes. Therefore, the air flow direction and the cathode off-gas flow direction are opposite to each other, so that the air is efficiently humidified.

Next, the effect of the humidifier 1 is demonstrated with reference to each figure.
Since the hollow fiber membranes 30a are filled at the same filling rate in each storage chamber 20, the resistance value to the flow in each storage chamber 20 is equivalent, and the air and cathode offgas flowing in each storage chamber 20 are respectively It will flow evenly.
Then, if a humid cathode off gas flows through each storage chamber 20, the hollow fiber membrane bundle 30 (hollow fiber membrane 30a) may swell and expand, but the hollow fiber membrane bundle 30 moves due to the expansion. Even so, the movement is effectively regulated by the vertical wall 11 and the horizontal wall 12 that partition each storage chamber 20. That is, the movement of the hollow fiber membrane bundles 30 stays in each storage chamber 20 and does not affect the movement of the hollow fiber membrane bundles 30 in the adjacent storage chambers 20.
Therefore, the flow distribution of the air and the cathode off-gas flowing through each storage chamber 20 is preferably maintained.

  According to the humidifier 1 of the present embodiment described above, the case 10 has a plurality of storage chambers 20 partitioned by the partition walls (vertical wall 11 and horizontal wall 12). Since the hollow fiber membrane bundle 30 (hollow fiber membrane 30a) is filled with the same filling rate, air and cathode off-gas flow evenly in the respective storage chambers 20 and flow distribution is improved.

  In addition, even when the hollow fiber membrane bundle 30 swells and expands due to the flow of air and cathode off-gas, the hollow fiber membrane bundle 30 is filled so as to be divided into a plurality of compartments 20 that are partitioned. Therefore, for example, as compared with the case where the hollow fiber membrane bundle is filled in a case that is not partitioned in this way, the movement due to the expansion of the hollow fiber membrane bundle 30 can be effectively controlled, The flow rate distribution of the air and the cathode off-gas flowing through the inside 20 can be suitably maintained.

  In addition, since the movement of the hollow fiber membrane bundle 30 due to the extension can be effectively controlled, the load applied to the hollow fiber membrane 30a due to the extension can be reduced, and the inconvenience such as the hollow fiber membrane 30a being cut off can be suitably used. Can be prevented.

  Further, since the movement of the hollow fiber membrane bundle 30 due to the extension can be effectively controlled, for example, a part of the hollow fiber membranes 30a moved by the extension may block the cathode 21 outflow port 21 and the outlet 22. The phenomenon of sticking can be prevented, and pressure loss can be prevented from increasing. That is, the cathode off gas can be suitably flowed through the inflow port 21 and the outflow port 22, and a suitable flow of the cathode off gas can be ensured even though the structure is provided with a plurality of storage chambers 20. Therefore, the humidifier 1 excellent in humidification efficiency is obtained.

  Further, since the cross-sectional shapes of the accommodation chamber 20 and the hollow fiber membrane bundle 30 in the ring cutting direction are different from each other, the hollow fiber membrane 30a is attached to the wall surfaces (vertical wall 11 and lateral wall 12) in each accommodation chamber 20. Sticking can be suppressed and good flow distribution can be suitably maintained.

  FIG. 7 is a view showing modifications of the humidifier of the present embodiment, (a) is a schematic cross-sectional view of the humidifier showing one modification, and (b) and (c) are other modifications. It is an expanded sectional view of the principal part of the humidifier which shows.

In the modification shown in FIG. 7A, the case 10 ′ has a cylindrical shape, and a plurality of storage chambers 20 having a rectangular cross section defined by the vertical wall 11 and the horizontal wall 12 are provided in the case 10 ′. In addition, a hollow fiber membrane bundle 30 having a circular cross section (round shape) is accommodated in each accommodating chamber 20.
In addition, in the modification shown in each drawing of FIG. 7 including this example, the inflow side manifold 15a, the outflow side manifold 16a, the inflow port 21 and the outflow port 22 are omitted for simplicity.
Also in such a modification, the same effect as the above-described embodiment can be obtained.

In the modification shown in FIG. 7B, the hollow fiber membrane bundle 30 having a circular cross section (round shape) is accommodated in the accommodating chamber 20A, with the sectional shape of the accommodating chamber 20A in the ring cutting direction being a honeycomb shape.
Further, in the modification shown in FIG. 7C, the hollow fiber membrane bundle 30A having a rectangular cross section is accommodated in the accommodating chamber 20B with the circular sectional shape of the accommodating chamber 20B in the ring cutting direction. is there.
According to these examples, since the cross-sectional shapes in the ring cutting direction of the accommodation chamber 20A (20B) and the hollow fiber membrane bundle 30 (30A) are different from each other, the hollow fiber to the wall surface in the accommodation chamber 20A (20B) Sticking of the film 30a can be suppressed, and good flow distribution can be suitably maintained.

As mentioned above, although one 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 the above-described embodiment, the configuration in which air flows through the hollow fiber membrane 30a and the cathode off-gas flows outside the hollow fiber membrane 30a is exemplified. However, the air flows outside the hollow fiber membrane 30a and the cathode has high humidity. The off gas may flow through the hollow fiber membrane 30a.

In addition, although the configuration in which the air and cathode off gas flow directions are opposite is illustrated, the same direction may be used.
Further, the cathode off gas is illustrated as flowing in from the top wall portion 15 side of the humidifier 1 and flowing out from the bottom wall portion 16 side of the humidifier 1, but the inflow / outflow direction of the cathode off gas is not limited thereto. For example, the structure which flows in from one side wall and flows out from the other side wall may be sufficient.
Further, the cathode off-gas is configured to flow in through the inlet 21 of the horizontal wall 12 of the storage chamber 20 and flow out through the outlet 22 of the horizontal wall 12, but the inflow / outflow direction is not limited to this. You may comprise so that it may flow in / out through 11.
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 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 with which the humidifier of this embodiment is applied. It is a partial exploded perspective view of the humidifier which concerns on this embodiment. Similarly, it is a sectional side view of the humidifier (a sectional side view taken along line X4-X4 in FIG. 4). It is sectional drawing which follows X1-X1 of FIG. It is sectional drawing which follows X2-X2 of FIG. It is sectional drawing which follows X3-X3 of FIG. It is a figure which shows the modification of the humidifier of this embodiment, respectively, (a) is a schematic cross section of the humidification direction of the humidifier which shows one modification, (b) (c) is humidification which shows another modification. It is an expanded sectional view of the principal part of a vessel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Humidifier 10 Case 11 Vertical wall 12 Horizontal wall 20 Accommodating chamber 20A Accommodating chamber 20B Accommodating chamber 21 Inlet 22 Outlet 30 Hollow fiber membrane bundle 30A Hollow fiber membrane bundle 30a Hollow fiber membrane 100 Fuel cell system 110 Fuel cell stack

Claims (2)

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 first fluid flows through the hollow fiber membrane, and a second fluid having a humidity different from that of the first fluid flows in the case and out of the hollow fiber membrane;
The humidifier in which the second fluid flows from the second fluid inflow portion of the case toward the outer peripheral surface of the hollow fiber membrane bundle,
In the case, provided with a plurality of storage chambers that are partitioned by a partition wall and each store the hollow fiber membrane bundle,
A humidifier, wherein the hollow fiber membrane bundle is filled into the plurality of storage chambers at the same filling rate.   2. The humidifier according to claim 1, wherein cross-sectional shapes of the storage chamber and the hollow fiber membrane bundle in a ring cutting direction are different from each other.

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