JP5350966B2 - Humidification module - Google Patents

Description

  The present invention relates to a humidifying module in which a plurality of hollow fiber membranes are accommodated in a cylindrical casing.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure (MEA) in which an anode side electrode and a cathode side electrode are disposed on both sides of an electrolyte membrane made of a polymer ion exchange membrane is provided by a pair of separators. The unit cell is sandwiched. This type of fuel cell is usually used as an in-vehicle fuel cell stack, for example, by stacking a predetermined number of unit cells.

  In this type of fuel cell, it is necessary to maintain the electrolyte membrane in a desired wet state in order to ensure good ion conductivity. For this reason, oxidant gas and fuel gas are generally humidified via a humidifier before being supplied to the fuel cell.

  For example, a solid polymer electrolyte fuel cell disclosed in Patent Document 1 includes a water vapor permeable membrane, a humidified gas chamber and a humidified gas chamber defined by the water vapor permeable membrane, and is discharged from a reaction gas passage. There is provided a reaction gas humidifier that humidifies the reaction gas by using the off gas as the humidification gas and the reaction gas supplied to the reaction gas passage as the humidification gas.

  However, in this Patent Document 1, moisture movement is performed by interposing a substantially planar water vapor permeable membrane and bringing the humidified gas and the humidified gas into contact with each other from both sides. For this reason, there exists a problem that the contact area | region of a water | moisture content is small and humidification efficiency falls.

  Therefore, for example, a supply gas humidifier disclosed in Patent Document 2 is known. In this supply gas humidifier, as shown in FIG. 8, a hollow fiber membrane bundle 2 made of an aggregate of hollow fiber membranes is accommodated in a jacket 1, and both ends of the hollow fiber membrane bundle 2 are provided with a pair of partition plates. 3 and 4 are fixed in the jacket 1.

  Gas chambers 5a and 5b are formed outside the partition plates 3 and 4, and a fuel gas supply line is connected to the gas chambers 5a and 5b. The gas chambers 5 a and 5 b communicate with the internal space 2 a of the hollow fiber membrane bundle 2. The inner space of the jacket 1 constitutes a water chamber 6, and the water chamber 6 communicates with a water inlet 7a and a water outlet 7b.

  Therefore, the fuel gas is introduced from one partition plate 3 into the internal space 2a of each hollow fiber membrane and flows toward the other partition plate 4 side, while cooling water is introduced from the water inlet 7a to the water chamber 6. ing. In the jacket 1, the fuel gas and cooling water flow in opposite directions, and the fuel gas is humidified by contacting the cooling water through the hollow fiber membranes.

JP-A-6-132038 JP-A-8-273687

  By the way, in the above-mentioned Patent Document 2, each hollow fiber membrane constituting the hollow fiber membrane bundle 2 is preliminarily considered in consideration of swelling during humidification when both ends are fixed to the partition plates 3 and 4. A space is provided between them. For this reason, each hollow fiber membrane is deformable and easily deforms greatly on the water inlet 7a side due to the water pressure of the cooling water introduced from the water inlet 7a. Therefore, the cooling water bypasses without being introduced between the hollow fiber membranes, and there is a problem that the humidification efficiency of the fuel gas is lowered.

  The present invention solves this type of problem, and an object thereof is to provide a humidifying module that can effectively use the whole of a plurality of hollow fiber membranes and can improve humidification efficiency satisfactorily. To do.

  The present invention relates to a cylindrical casing, a plurality of hollow fiber membranes housed in the cylindrical casing, a first flow path formed inside the hollow fiber membrane for circulating a first fluid, and the hollow fiber A second flow path formed between the outer side of the membrane and the inner wall of the cylindrical casing and allowing a moisture to move between the first fluid and the second fluid by circulating a second fluid; The present invention relates to a humidifying module provided on an outer peripheral portion of a cylindrical casing and including an inlet portion communicating with an inlet side of the second flow channel and an outlet portion communicating with an outlet side of the second flow channel.

The humidifying module is disposed in the cylindrical casing, extends along the extending direction of the hollow fiber membrane, partitions the cylindrical casing into a plurality of hollow fiber membrane layers, and intersects the extending direction. Are provided with a plurality of cylindrical porous bodies having different opening dimensions. Each hollow fiber membrane layer accommodates a hollow fiber membrane, while a cylindrical porous body having a maximum opening size is disposed on the outermost periphery, and the cylindrical porous body having a relatively small opening size is relatively arranged in the interior of large the cylindrical porous body opening dimension constitutes the hollow fiber membrane layer to a multilayer, at least one of the cylindrical porous body is fixed to the inner wall of the cylindrical casing constituting the inlet portion Has been.

  Moreover, it is preferable that an entrance part and an exit part are provided in the position mutually symmetrical with respect to the outer peripheral part of a cylindrical casing.

Further, the humidifying module has no hollow fiber membrane between the cylindrical porous body having the maximum opening size and the cylindrical casing, and the cylindrical porous body having the maximum opening size and the outlet portion. It is preferable that a sticking prevention portion is provided between the two and a gap.

  Furthermore, it is preferable that a cylindrical porous body is fixed to the inner wall part of a cylindrical casing along the extension direction from an inlet part.

  Moreover, it is preferable that a cylindrical porous body is comprised by cylindrical shape or a rectangular tube shape.

  According to the present invention, the inside of the cylindrical casing is partitioned into a plurality of hollow fiber membrane layers by the cylindrical porous body, and the plurality of hollow fiber membranes are accommodated and held in the hollow fiber membrane layer. Therefore, the deformation of the hollow fiber membrane is satisfactorily suppressed.

  And at least 1 cylindrical porous body is being fixed to the inner wall part of the cylindrical casing which comprises an inlet_port | entrance part. For this reason, it can prevent that the hollow fiber membrane near the said inlet part deform | transforms with the fluid introduce | transduced from an inlet part, and suppresses the said fluid bypassing in the vicinity of the said inlet part favorably. Is possible.

  As a result, the flow of the fluid can be optimized, the deformation of the hollow fiber membrane can be suppressed, and the entire hollow fiber membrane can be effectively used to improve the humidification efficiency satisfactorily. .

1 is a schematic configuration diagram of a fuel cell system incorporating a humidifying module according to a first embodiment of the present invention. It is a schematic perspective view of the humidifying module. It is a cross-sectional side view of the module for humidification. It is front explanatory drawing from one edge part of the said module for humidification. It is front explanatory drawing from the other edge part of the said humidification module. It is a schematic perspective explanatory drawing of the humidification module which concerns on the 2nd Embodiment of this invention. It is a cross-sectional side view of the module for humidification. It is explanatory drawing of the supply gas humidification apparatus currently disclosed by patent document 2. FIG.

  As shown in FIG. 1, the humidifying module 10 according to the first embodiment of the present invention is incorporated in a fuel cell system 12. The fuel cell system 12 is mounted on a fuel cell vehicle (not shown).

  The fuel cell system 12 includes a fuel cell stack 14, a cooling medium supply mechanism 16 for supplying a cooling medium to the fuel cell stack 14, and an oxidant gas (reactive gas) for supplying the fuel cell stack 14. An oxidant gas supply mechanism 18 and a fuel gas supply mechanism 20 for supplying fuel gas (reactive gas) to the fuel cell stack 14 are provided.

  The cooling medium supply mechanism 16 includes a radiator 24. A cooling medium supply pipe 28 and a cooling medium discharge pipe 30 are connected to the radiator 24 via a refrigerant pump 26.

  The oxidant gas supply mechanism 18 includes an air pump 32. The air supply pipe 34 having one end connected to the air pump 32 is connected to the humidifying module 10 at the other end. A fuel cell stack 14 is connected to the humidifying module 10 via a humidified air supply pipe 38.

  The humidifying module 10 is provided with an off-gas discharge pipe 39 for supplying an oxidizing gas (hereinafter also referred to as off-gas) containing used product water from the fuel cell stack 14 as a humidifying fluid. Further, a back pressure valve (not shown) is disposed on the exhaust side of the off gas from the humidifying module 10.

The fuel gas supply mechanism 20 includes a fuel gas tank (fuel tank) 40 in which hydrogen gas (H ₂ gas) is stored as fuel gas. One end of a fuel gas supply pipe 42 is connected to the fuel gas tank 40, and a shutoff valve 44, a regulator 46 and an ejector 48 are connected to the fuel gas supply pipe 42, and the ejector 48 is a fuel cell stack. 14.

  An exhaust fuel gas pipe 50 for discharging the used fuel gas is connected to the fuel cell stack 14. The exhaust fuel gas pipe 50 is connected to the ejector 48 via a return pipe 52 and partly communicates with the purge valve 54. Although not shown, a diluter is disposed downstream of the purge valve 54.

  In the fuel cell stack 14, a plurality of power generation cells 56 are stacked in the horizontal direction that is the vehicle length direction or in the direction of gravity. Although not shown, each power generation cell 56 includes an electrolyte membrane / electrode structure and a pair of separators that sandwich the electrolyte membrane / electrode structure. The electrolyte membrane / electrode structure includes, for example, a solid polymer electrolyte membrane in which water is impregnated with a thin film of perfluorosulfonic acid, and an anode side electrode and a cathode side electrode that sandwich the solid polymer electrolyte membrane.

  The fuel cell stack 14 extends in the stacking direction of the power generation cells 56, and supplies an oxidant gas supply communication hole 58a for supplying an oxidant gas, for example, air, and a fuel gas, for example, hydrogen gas. The fuel gas supply communication hole 60a, the cooling medium supply communication hole 62a for supplying the cooling medium, the oxidant gas discharge communication hole 58b for discharging the oxidant gas, and the fuel gas discharge for discharging the fuel gas A communication hole 60b and a cooling medium discharge communication hole 62b for discharging the cooling medium are provided.

  The oxidant gas supply communication hole 58 a and the oxidant gas discharge communication hole 58 b communicate with the humidified air supply pipe 38 and the off-gas discharge pipe 39. The fuel gas supply communication hole 60 a and the fuel gas discharge communication hole 60 b communicate with the fuel gas supply pipe 42 and the exhaust fuel gas pipe 50. The cooling medium supply communication hole 62 a and the cooling medium discharge communication hole communicate with the radiator 24 via the cooling medium supply pipe 28 and the cooling medium discharge pipe 30.

  As shown in FIGS. 2 to 4, the humidifying module 10 includes, for example, a cylindrical casing 70 having a cylindrical shape, and the cylindrical casing 70 is configured to be long in the arrow A direction. The cylindrical casing 70 is opened at both ends in the direction of arrow A, and, for example, four inlet portions 72a are formed at the end edge in the direction of arrow A1, while the end edge in the direction of arrow A2 is, for example, Four outlet portions 72b are formed. The inlet portion 72 a and the outlet portion 72 b are provided at positions that are symmetric with respect to the outer peripheral portion of the cylindrical casing 70.

  Inside the cylindrical casing 70, a plurality of cylindrical porous bodies, for example, a first porous body 74a, a second porous body 74b, a third porous body 74c, and a fourth porous body 74d are disposed. The first porous body 74a to the fourth porous body 74d have different opening sizes. In the first embodiment, the first porous body 74a to the fourth porous body 74d have cylindrical shapes having different diameters, and the fourth porous body 74d has a maximum diameter (maximum opening size). ).

  The first porous body 74a to the fourth porous body 74d have, for example, a net structure or a mesh structure made of metal or plastic. Note that the first porous body 74a to the fourth porous body 74d maintain a balance between rigidity and elasticity that can provide a good restraining force in order to prevent the movement of the accommodated hollow fiber membrane 78 (described later). There is a need.

  A first hollow fiber membrane layer 76a is formed inside the first porous body 74a, and a second hollow fiber membrane layer 76b is formed between the first porous body 74a and the second porous body 74b. The A third hollow fiber membrane layer 76c is formed between the second porous body 74b and the third porous body 74c, and a fourth hollow fiber is formed between the third porous body 74c and the fourth porous body 74d. A film layer 76d is formed.

  A plurality of hollow fiber membranes 78 are accommodated in the first hollow fiber membrane layer 76a, the second hollow fiber membrane layer 76b, the third hollow fiber membrane layer 76c, and the fourth hollow fiber membrane layer 76d, respectively. Both ends of each hollow fiber membrane 78 and the first porous body 74 a to the fourth porous body 74 d are fixed to both ends in the axial direction of the cylindrical casing 70 via seal portions 80, 80.

  The hollow fiber membrane 78 is made of, for example, a polymer ion exchange membrane such as phenol sulfonic acid, polystyrene sulfonic acid, polytrifluorostyrene sulphonic acid, perfluorocarbon sulfonic acid, a polymer resin-based or ceramic-based material, or the like. The

  Inside each hollow fiber membrane 78, an air supply pipe 34 communicates with the inlet side, while a humidified air supply pipe 38 communicates with the outlet side, and an oxidant through which an oxidant gas (first fluid) before use flows. A gas flow path (first flow path) 82 is formed. In the cylindrical casing 70, an offgas passage (second passage) 84 for allowing offgas (second fluid) to flow outside the hollow fiber membrane 78 is formed.

  In the off-gas channel 84, the inlet portion 72a communicates with the inlet side, and the outlet portion 72b communicates with the outlet side. The flow direction (arrow B direction) of the inlet portion 72a and the outlet portion 72b intersects the flow direction (arrow A direction) of the oxidant gas flow channel 82. The inlet portion 72a communicates with the offgas discharge pipe 39, and the offgas supplied from the offgas discharge pipe 39 flows along the offgas flow path 84 in the direction of the arrow A2. The oxidant gas supplied from the air supply pipe 34 to each oxidant gas flow path 82 flows along the oxidant gas flow path 82 in the direction of the arrow A1. The off gas channel 84 and the oxidant gas channel 82 are set to counterflow.

  In the first embodiment, at least the fourth porous body 74d and substantially the first porous body 74a to the fourth porous body 74d are fixed to the inner wall portion of the cylindrical casing 70 constituting the inlet portion 72a. . As shown in FIGS. 2 and 4, a part of the first porous body 74a to the fourth porous body 74d is formed on the inner wall portion of the cylindrical casing 70 in the extending direction of the hollow fiber membrane 78 from the inlet portion 72a (the direction of arrow A). ) Is provided along the bonding area 86.

  As shown in FIG. 5, a sticking prevention portion 88 is formed in the cylindrical casing 70 by forming a gap S between the fourth porous body 74d having the maximum diameter (maximum opening size) and the outlet portion 72b. It is done.

  The operation of the fuel cell system 12 configured as described above will be described below in relation to the humidifying module 10 according to the first embodiment.

  First, as shown in FIG. 1, the air pump 32 constituting the oxidant gas supply mechanism 18 is driven, and external air that is an oxidant gas is sucked and introduced into the air supply pipe 34. This air is introduced into the humidifying module 10 from the air supply pipe 34, flows through the oxidant gas flow path 82 in each hollow fiber membrane 78 in the direction of the arrow A1, and is supplied to the humidified air supply pipe 38 (FIG. 2 and FIG. 3).

  At this time, as will be described later, off-gas which is an oxidant gas used for the reaction is supplied from the off-gas discharge pipe 39 to the off-gas flow path 84 via the inlet 72a, and this off-gas flows in the direction of the arrow A2. ing. For this reason, the air before use and the off-gas are counterflowed, and moisture contained in the off-gas moves to the air before use, and the air before use is humidified. The humidified air is supplied from the humidified air supply pipe 38 to the oxidant gas supply communication hole 58a in the fuel cell stack 14 (see FIG. 1).

  On the other hand, in the fuel gas supply mechanism 20, the fuel gas (hydrogen gas) derived from the fuel gas tank 40 is lowered by the regulator 46 under the opening action of the shutoff valve 44, and then passes through the ejector 48 to the fuel cell stack 14 It is introduced into the fuel gas supply communication hole 60a.

  Further, in the cooling medium supply mechanism 16, the cooling medium is introduced from the cooling medium supply pipe 28 into the cooling medium supply communication hole 62 a in the fuel cell stack 14 under the action of the refrigerant pump 26.

  The air supplied to each power generation cell 56 in the fuel cell stack 14 moves along the cathode side electrode of the electrolyte membrane / electrode structure. On the other hand, the fuel gas moves along the anode side electrode of the electrolyte membrane / electrode structure. Therefore, in each electrolyte membrane / electrode structure, oxygen in the air and fuel gas (hydrogen) are consumed by an electrochemical reaction in the electrode catalyst layer, and electric power is generated. Next, the air consumed by the power generation reaction flows along the oxidant gas discharge communication hole 58b and is then discharged to the offgas discharge pipe 39 as offgas.

  In this case, in the first embodiment, as shown in FIGS. 2 to 5, the inside of the cylindrical casing is constituted by the first porous body 74a, the second porous body 74b, the third porous body 74c, and the fourth porous body 74d. The first hollow fiber membrane layer 76a, the second hollow fiber membrane layer 76b, the third hollow fiber membrane layer 76c, and the fourth hollow fiber membrane layer 76d are partitioned. Accordingly, the first hollow fiber membrane layer 76a, the second hollow fiber membrane layer 76b, the third hollow fiber membrane layer 76c and the fourth hollow fiber membrane layer 76d each contain and hold a plurality of hollow fiber membranes 78, By being held by the first hollow fiber membrane layer 76a to the fourth hollow fiber membrane layer 76d, deformation of the hollow fiber membrane 78 is satisfactorily suppressed.

  Moreover, the first porous body 74a to the fourth porous body 74d have an adhesion portion 86 that is adhered to the inner wall portion of the cylindrical casing 70 along the extending direction (arrow A direction) of the hollow fiber membrane 78 from the inlet portion 72a. Provided. For this reason, it is possible to prevent the hollow fiber membrane 78 in the vicinity of the inlet portion 72a from being deformed by the offgas introduced from the inlet portion 72a of the cylindrical casing 70, and the offgas is generated in the vicinity of the inlet portion 72a. It becomes possible to suppress bypassing satisfactorily.

  Thereby, it is possible to optimize the flow of off-gas in the off-gas channel 84 and to suppress the deformation of the hollow fiber membrane 78, and to effectively use the entire hollow fiber membrane 78 to increase the humidification efficiency. The effect that it can improve favorably is acquired.

  In the first embodiment, the first porous body 74a to the fourth porous body 74d are fixed to the inner wall portion of the cylindrical casing 70 constituting the inlet portion 72a. For example, only the first porous body 74a is provided. It may be bonded to the inner wall portion of the cylindrical casing 70 along the extending direction (arrow A direction) of the hollow fiber membrane 78 from the inlet portion 72a. Also in this case, deformation of the hollow fiber membrane 78 in the vicinity of the inlet portion 72a can be effectively prevented.

  Furthermore, in the first embodiment, as shown in FIG. 5, a sticking prevention portion 88 is provided by forming a gap S between the fourth porous body 74d and the outlet portion 72b. Therefore, the hollow fiber membrane 78 is pressed against the inner wall surface of the cylindrical casing 70 by the gas pressure of the off gas flowing through the off gas passage 84 and discharged from the outlet portion 72b, and the outlet portion 72b is partially or totally blocked. It will not be done. For this reason, it becomes possible to prevent the pressure loss of the off-gas flow path 84 from increasing as much as possible.

  FIG. 6 is a schematic perspective explanatory view of the humidifying module 100 according to the second embodiment of the present invention, and FIG. 7 is a cross-sectional explanatory view of the humidifying module 100. Note that the same components as those in the humidifying module 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The humidifying module 100 includes a cylindrical casing 102 having a rectangular tube shape. In the cylindrical casing 102, a cylindrical first porous body 104a, a second porous body 104b, a third porous body 104c, and a fourth porous body 104d are arranged in the longitudinal direction (arrow A direction) of the cylindrical casing 102. It is extended and arranged.

  Inside the cylindrical casing 102, the first hollow fiber membrane layer 106a, the second hollow fiber membrane layer 106b, the third hollow fiber membrane layer 106c, and the fourth hollow fiber membrane layer are formed by the first porous body 104a to the fourth porous body 104d. 106d. A plurality of hollow fiber membranes 78 are accommodated in each of the first hollow fiber membrane layer 106a to the fourth hollow fiber membrane layer 106d.

  In the second embodiment, at least the fourth porous body 104d and substantially the first porous body 104a to the fourth porous body 104d are fixed to the inner wall portion of the cylindrical casing 102 constituting the inlet portion 72a. . A part of the first porous body 104a to the fourth porous body 104d is bonded to the inner wall portion of the cylindrical casing 102 along the extending direction (arrow A direction) of the hollow fiber membrane 78 from the inlet portion 72a. Is provided.

  In the cylindrical casing 102, as shown in FIG. 7, a sticking prevention part 110 is provided by forming a gap S between the fourth porous body 104d having the maximum opening dimension and the outlet part 72b.

  In the second embodiment configured as described above, the inside of the cylindrical casing 102 is partitioned into the first hollow fiber membrane layer 106a to the fourth hollow fiber membrane layer 106d by the first porous body 104a to the fourth porous body 104d. In addition, the first porous body 104 a to the fourth porous body 104 d are bonded to the inner wall portion of the cylindrical casing 102.

  Thereby, it becomes possible to suppress the deformation of the hollow fiber membrane 78, the humidification efficiency can be improved satisfactorily by effectively using the entire hollow fiber membrane 78, and the like in the first embodiment. Similar effects can be obtained.

DESCRIPTION OF SYMBOLS 10,100 ... Module for humidification 12 ... Fuel cell system 14 ... Fuel cell stack 16 ... Coolant supply mechanism 18 ... Oxidant gas supply mechanism 20 ... Fuel gas supply mechanism 24 ... Radiator 34 ... Air supply piping 38 ... Humidified air supply piping 39 ... Off-gas discharge pipe 56 ... Power generation cell 70, 102 ... Cylindrical casing 72a ... Inlet part 72b ... Outlet part 74a-74d, 104a-104d ... Porous body 76a-76d, 106a-106d ... Hollow fiber membrane layer 78 ... Hollow fiber Membrane 82 ... Oxidant gas flow path 84 ... Off gas flow path 86, 108 ... Adhesion site 88, 110 ... Sticking prevention part

Claims (6)

A cylindrical casing;
A plurality of hollow fiber membranes housed in the cylindrical casing;
A first flow path formed inside the hollow fiber membrane for circulating a first fluid;
A second flow path that is formed between the outer side of the hollow fiber membrane and the inner wall of the cylindrical casing, and circulates a second fluid to move moisture between the first fluid and the second fluid; ,
An outer peripheral portion of the cylindrical casing, an inlet portion communicating with an inlet side of the second flow path, and an outlet portion communicating with an outlet side of the second flow path;
A humidifying module comprising:
The cylindrical casing is disposed in the cylindrical casing, extends along the extending direction of the hollow fiber membrane, partitions the cylindrical casing into a plurality of hollow fiber membrane layers, and has an opening dimension in a direction intersecting the extending direction. It has a plurality of different cylindrical porous bodies,
Each hollow fiber membrane layer accommodates the hollow fiber membrane,
The cylindrical porous body having the largest opening dimension is disposed on the outermost periphery, and the cylindrical porous body having a relatively small opening dimension is disposed inside the cylindrical porous body having a relatively large opening dimension. The yarn film layer is composed of multiple layers,
At least one of the tubular multi hole body is humidifying module, characterized in that fixed to the inner wall of the cylindrical casing constituting the inlet portion.   2. The humidification module according to claim 1, wherein the inlet portion and the outlet portion are provided at positions symmetrical to each other with respect to an outer peripheral portion of the cylindrical casing. The humidifying module according to claim 1 or 2 , wherein the hollow fiber membrane is not provided between the cylindrical porous body having the maximum opening size and the cylindrical casing, and the maximum opening size is provided. A humidifying module , wherein a sticking prevention portion is provided by forming a gap between the cylindrical porous body and the outlet portion.   The humidification module according to any one of claims 1 to 3, wherein the cylindrical porous body is fixed along the extension direction from the inlet portion to the inner wall portion of the cylindrical casing. Feature humidifying module.   The humidification module according to any one of claims 1 to 4, wherein the cylindrical porous body is configured in a cylindrical shape or a rectangular tube shape. The humidifying module according to any one of claims 1 to 5, wherein a plurality of the cylindrical porous bodies are integrally fixed to an inner wall portion of the cylindrical casing. A humidifying module.

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