WO2013167946A1

WO2013167946A1 - Ion exchanger and fuel cell system provided with same

Info

Publication number: WO2013167946A1
Application number: PCT/IB2013/000813
Authority: WO
Inventors: Hideaki SAKAKIBARA; Kunihiro Yamaura
Original assignee: Toyota Jidosha Kabushiki Kaisha; Toyota Boshoku Kabushiki Kaisha
Priority date: 2012-05-08
Filing date: 2013-05-02
Publication date: 2013-11-14
Also published as: WO2013167946A8; JP2013233499A

Abstract

An ion exchanger includes an ion exchange resin cartridge, a case, and a lid of the case. The ion exchange resin cartridge is housed in the case. Also, the ion exchange resin cartridge is removably fixed to the lid.

Description

ION EXCHANGER AND FUEL CELL SYSTEM PROVIDED WITH SAME

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The invention relates to an ion exchanger and a fuel cell system provided with this ion exchanger. More particularly, the invention relates to an improvement of the structure of an ion exchanger provided in a fuel cell system or the like.

2. Description of Related Art

[0002] An ion exchanger is used as an apparatus for removing impurities from a cooling medium (coolant) in a cooling system of a fuel cell, for example. Ion exchange resin of the ion exchanger is resin having a reticular structure that is formed of a polymer electrolyte having an ion exchangeable group. With the ion exchange resin, ions adsorbed by ion exchange are introduced not only onto the surface of the resin, but also into the resin. There are cases in which metal ions or fluorine ions are present in impurities leached from conduit components or the like of a fuel cell system, for example. These ions may lead to metal corrosion and a decrease in the fuel cell function. This kind of ion exchange resin is able to adsorb these ions, thereby removing them.

[0003] This kind of ion exchanger must be replaced regularly. Japanese Patent Application Publication No. 2010-067369 (JP 2010-067369 A), for example, describes a related ion exchanger in which a case and ion exchange resin are integrated, and the ion exchanger is replaced together with the case.

[0004] However, if the case and the ion exchange resin are integrated, a portion where the ion exchanger is connected to another cooling system component must be disconnected when replacing the ion exchanger. Therefore, workability during replacement is poor when the case and the ion exchange resin are integrated.

[0005] More specifically, when replacing the ion exchanger, the portion where the ion exchanger is connected to the other cooling system component is temporarily closed off with a hose clip, for example, in order to keep coolant from spilling out. However, even in this case, coolant in the ion exchanger and the hose may still end up spilling out. In this case, coolant of the amount that spilled out must be added, which is a bother. In view of this, the work must be performed taking care so that the coolant in the ion exchanger does not spill out, which makes the work of replacing the ion exchanger troublesome. As a result, the ease and efficiency of the work decreases.

SUMMARY OF THE INVENTION

[0006] The invention thus provides an ion exchanger configured such that the work of replacing ion exchanger is able to be performed easily, as well as a fuel cell system that includes this ion exchanger.

[0007] A first aspect of the invention relates to an ion exchanger that includes an ion exchange resin cartridge, a case within which the ion exchange resin cartridge is housed, and a lid of the case. The ion exchange resin cartridge is removably fixed to the lid.

[0008] With this kind of ion exchanger, the ion exchange resin cartridge is removed at the same time that the lid is removed. Therefore, the ion exchange resin cartridge is able- to be replaced without spilling the cooling medium, without having to close off the connecting portion that connects the ion exchanger to another component. Accordingly, there is no need to replace the case along with the ion exchanger, and the portion that connects the ion exchanger to another cooling system component does not need to be closed off, so the work of replacing the ion exchanger is simplified.

[0009] Also, a second aspect of the invention relates to a fuel cell system that includes a fuel cell, an ion exchanger, and a conduit that is connected to the fuel cell The fuel cell generates power by an electrochemical reaction of a reaction gas. The ion exchanger includes an ion exchange resin cartridge, a case within which the ion exchange resin cartridge is housed, and a lid of the case. The ion exchange resin cartridge is removably fixed to the lid. The ion exchanger is arranged in the conduit. This kind of fuel cell system may be provided in a fuel cell vehicle. Furthermore, the ion exchanger may be mounted near an upper portion inside a power compartment of a fuel cell vehicle.

[0010] According to these aspects of the invention, the work of exchanging the ion exchanger is able to be performed easily.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

FIG. 1 is a diagram of the structure of a fuel cell system according to one example embodiment of the invention;

FIG. 2 is a sectional view of a structural example of an ion exchanger according to the example embodiment of the invention;

FIG. 3 is an exploded perspective view of a structural example of the example embodiment according to the invention;

FIG. 4 is a diagram of an example of cooling medium conduit system of the fuel cell system; and

FIG. 5 is a view of a front portion of a fuel cell vehicle illustrating an example arrangement of the ion exchanger.

DETAILED DESCRIPTION OF EMBODIMENTS

[0012] FIGS. 1 to 5 are views of an ion exchanger according to an example embodiment of the invention. An ion exchanger 47 according to the example embodiment of the invention includes an ion exchange resin 47h, a cartridge upper portion 47c, a cartridge lower portion 47d, a case 47e, and a lid 47f of the case 47e (see FIGS. 2 and 3). The cartridge upper portion 47c and the cartridge lower portion 47d are housed in the case 47e. In this example embodiment, the ion exchange resin 47h, the cartridge upper portion 47c, and the cartridge lower portion 47d together form an ion exchange resin cartridge 47b. In the description below, regarding FIG. 2, "upper portion" refers to a portion that is located superior to "lower portion" with respect to the upper-lower direction as shown in FIG. 2. The ion exchanger 47 is used in a fuel cell system 1 that is provided in a fuel cell vehicle FCV, for example (see FIG. 1 and the like). Below, the overall structure of the fuel cell system 1 of this example embodiment of the invention will be described. Then the structure of the ion exchanger 47 and the like will be described.

[0013] FIG. 1 is a block diagram of the fuel cell system 1 according to this example embodiment. As shown in the drawing, the fuel cell system 1 includes a fuel cell 2, an oxidizing gas conduit system 3, a fuel gas conduit system 4, a cooling medium conduit system 5, an electric power system (not shown), and a control portion 7 that comprehensively controls the overall system. The oxidizing gas conduit system 3 supplies air (oxygen) as an oxidizing gas to the fuel cell 2. The fuel gas conduit system 4 supplies hydrogen as a fuel gas to the fuel cell 2. The cooling medium conduit system 5 supplies a cooling medium to the fuel cell 2 to cool the fuel cell 2. The electric power system charges and discharges the electric power (hereinafter also simply referred to as "power") of the system.

[0014] The fuel cell 2 is a polymer electrolyte fuel cell, for example, and may have a stacked structure in which multiple single cells are stacked together. The single cells of the fuel cell 2 each have an air electrode on one surface of an electrolyte made of an ion exchange membrane, and a fuel electrode on the other surface. Furthermore, the single cells of the fuel cell 2 each have a pair of separators that sandwich the air electrode and the fuel electrode from both sides. The fuel cell 2 generates power by the fuel gas being supplied to a fuel gas flow path of one separator, and the oxidizing gas being supplied to an oxidizing gas flow path of the other separator.

[0015] The oxidizing gas conduit system 3 includes a gas supply flow path 11 and a gas discharge path 12. The oxidizing gas supplied to the fuel cell 2 flows through the gas supply flow path 11. Oxide off gas discharged from the fuel cell 2 flows through the gas discharge path 12. A compressor 14 that takes in the oxidizing gas via an air cleaner (a filter) 13 is provided in the gas supply flow path 11. A muffler 18 is provided in the gas discharge path 12. The oxide off gas flows through the gas discharge path 12 and the muffler 18, and is discharged into the atmosphere outside of the system as exhaust gas. The compressor 14 is driven by a motor 14a to take in oxidizing gas in the atmosphere.

[0016] The fuel gas conduit system 4 includes a hydrogen supply source 21, a gas supply flow path 22, a hydrogen off gas circulation line 23, and a pump 24. Hydrogen gas supplied from the hydrogen supply source 21 to the fuel cell 2 flows through the gas supply flow path 22. Hydrogen off gas (fuel off gas) discharged from the fuel cell 2 flows through the hydrogen off gas circulation line 23 and returns to a merging point A of the gas supply flow path 22. The pump 24 (hereinafter also referred to as "hydrogen pump 24") delivers hydrogen off gas that is inside the hydrogen off gas circulation line 23 to the gas supply flow path 22. The hydrogen pump 24 is driven by a motor 24a to circulate and supply the hydrogen gas that is inside the circulation system to the fuel cell 2.

[0017] The hydrogen supply source 21 is formed by a high pressure hydrogen tank or a hydrogen storing alloy, for example. The hydrogen supply source 21 stores hydrogen gas at 35 MPa or 70 MPa, for example. When a valve such as a master valve of the hydrogen supply source 21 is opened, hydrogen gas flows out into the gas supply flow path 22. The hydrogen gas is ultimately reduced in pressure to approximately 200 kPa, for example, by a pressure regulating valve 27 and/or another a pressure reduction valve, and then supplied to the fuel cell 2. ,

[0018] The cooling medium conduit system (cooling system) 5 includes a cooling medium flow path 41 , a coolant pump 42, a radiator 43, a bypass flow path 44, a three-way valve 45, a coolant conduit 46, and the ion exchanger 47. The cooling medium flow path 41 is communicated with a coolant flow path inside the fuel cell 2. The coolant pump 42 is provided in the cooling medium flow path 41. The radiator 43 cools the cooling medium discharged from the fuel cell 2. The radiator 43 is bypassed via the bypass flow path 44. The three-way valve 45 sets the flow of coolant to either the radiator 43 or the bypass flow path 44. The coolant pump 42 is driven by a motor 42a to circulate and supply the cooling medium within the cooling medium flow path 41 to the fuel cell 2. Also, the coolant conduit 46 includes an upper coolant conduit 46a and a lower coolant conduit 46b (see FIG. 2). The upper coolant conduit 46a and the lower coolant conduit 46b may be regarded as a first conduit of the invention and a second conduit of the invention, respectively.

~ [0019] The control portion 7 is formed by a microcomputer having a CPU, ROM, and RAM inside. The CPU executes desired calculations according to a control program, and performs various processing and control such as defrost control of the pump 24. The ROM stores control data and control programs to be processed by the CPU. The RAM is mainly used as a selectable work area for the control processing. The control portion 7 receives detection signals from various sensors, such as a pressure sensor, a temperature sensor, and an outside air temperature sensor, used by the gas systems (i.e., the oxidizing gas conduit system 3 and the fuel gas conduit system 4), and the cooling medium conduit system 5, and outputs control signals to the various constituent elements.

[0020] Continuing on, the structure of the ion exchanger 47 will now be described (see FIGS. 2 and 3).

[0021] In this example embodiment, the_. ion exchanger 47 is provided in the coolant conduit 46 of the cooling medium conduit system 5. That is, the ion exchanger 47 is arranged in the coolant conduit 46. This ion exchanger 47 serves as an apparatus for removing impurities from within the cooling medium (e.g., coolant) that is circulated (i.e., functions as an impurity removing apparatus). The coolant conduit 46 is formed by a conduit that connects the cooling medium flow path 41 to the bypass flow path 44 (see FIG. 4 and the like). The cartridge upper portion 47c and the cartridge lower portion 47d are provided in the ion exchanger 47. The ion exchange resin 47h is filled in between the cartridge upper portion 47c and the cartridge lower portion 47d. The lid 47f that is able to be opened and closed or removed when replacing the ion exchange resin cartridge 47b is provided on the case 47e of the ion exchanger 47. The case 47e and the lid 47f form lower and upper portions, respectively, of the casing. The case 47e and the lid 47f are fastened together using press-fit nuts and bolts or the like, neither of which is shown, embedded in the main body of the case 47e. Stainless steel, or more specifically, SUS304, for example, is used as the material of the case 47e.

[0022] The lid 47f is attached to the upper side of the case 47e, in the direction of gravitational force, in the ion exchanger 47 when the ion exchanger 47 is attached to the fuel cell vehicle FCV. Therefore, the ion exchanger 47 is configured such- that coolant will not spill out of the case 47e even when the lid 47f is removed from the case 47e. Hereinafter, the direction of gravitational force may be regarded as the vertical direction of the fuel cell vehicle FCV. For example, the lid 47f may be considered to be attached to the upper portion of the case 47e in the vertical direction of the fuel cell vehicle FCV.

[0023] Intake / discharge ports 47gl and 47g2 to which the coolant conduit 46 is connected are provided in the case 47e (see FIGS. 2 and 3). Hereinafter, the intake / discharge port 47gl is also referred to as "intake port 47gl" and the intake / discharge port 47g2 is also referred to as "discharge port 47g2" in this example embodiment. The intake port 47gl serves as an upper port, and the discharge port 47g2 serves as a lower port. The intake port 47gl is connected to the upper coolant conduit 46a, and the discharge port 47g2 is connected to the lower coolant conduit 46b. The intake / discharge ports 47gl and 47g2 are integrally formed with the case 47e. Here, the ion exchange resin cartridge 47b is arranged between the intake / discharge ports 47gl and 47g2 in the vertical direction of the fuel cell vehicle FCV. The lid 47f may also be provided higher than the coolant conduit 46 in the vertical direction of the fuel cell vehicle FCV so that coolant will not spill out. Also, the intake port 47gl may be regarded as the first port of the invention, and the discharge port 47g2 may be regarded as the second port of the invention.

[0024] Also, a bracket 47n that serves as a vehicle body fixing portion for directly fixing the case 47e to the vehicle body is integrally formed on the case 47e (see FIG. 3). This kind of bracket 47n dissipates vibration of the vehicle body of the fuel cell vehicle FCV, thereby making it possible to suppress vibration of the ion exchange resin cartridge 47b and the like.

[0025] As described above, the ion exchange resin cartridge 47b is a cartridge that includes the ion exchange resin 47h. The ion exchange resin 47h has a reticulate structure formed by a polymer electrolyte having an ion exchangeable group. In this way, the ion exchange resin cartridge 47b has a function of adsorbing ions through ion exchange. For example, the ion exchange resin cartridge 47b of this example embodiment has a cation exchange resin and an anion exchange resin. The ion exchange resin 47h is usually granular, but it may also be fibrous. The cartridge upper portion 47c is able to be detached from the cartridge lower portion 47d. The structure for enabling the cartridge upper portion 47c to be detached from the cartridge lower portion 47d is not particularly limited. In this example embodiment, a structure is employed that has pawl members 47j formed on an outer periphery of the cartridge lower portion 47d, and elastic hook members 47k that are retained by these pawl members 47j (see FIG. 3).

[0026] Here, the ion exchange resin cartridge 47b in this example embodiment is removably fixed to the lid 47f of the case 47e. With this type of ion exchanger 47, the ion exchange resin cartridge 47b is able to be removed from the case 47e simply by removing the lid 47f. Therefore, the ion exchange resin cartridge 47b is able to be replaced without spilling any coolant, without the hassle of closing off the portion where the ion exchanger 47 is connected to another component (i.e., without the hassle of temporarily closing off the coolant conduit 46 that is connected to the intake / discharge ports 47gl and 47g2 with hose clips).

[0027] In this way, the specific structure for removably fixing the ion exchange resin cartridge 47b to the lid 47f is not particularly limited. For example, in this example embodiment, a cartridge that includes resin is formed by sandwiching or inserting the ion exchange resin 47h between the cartridge upper portion 47c and the cartridge lower portion 47d. Also, the ion exchange resin cartridge 47b, together with ion exchange resin 47h, is screwed in from below the lid 47f, and is thus retained by a portion of the lid 47f (a cylindrical portion 47i of the lid 47f, for example). The cylindrical portion 47i may be regarded as a retained portion of the invention. Mesh 47m is arranged on the upper and lower surfaces of the ion exchange resin 47h. One of the meshes 47m may be insert-formed with the case 47e, for example. The coarseness of the eyes of the mesh 47m need only be such that the ion exchange resin 47h will not fall through. Furthermore, the ion exchange resin cartridge 47b is housed inside the case 47e by attaching and fastening the lid 47f to the case 47e (see FIG. 2). With this example embodiment structured as described above, during replacement, only the ion exchange resin cartridge 47b is replaced. The case 47e and the lid 47f may be appropriated as they are (i.e., may continue to be used as they are).

[0028] Also, the axis of the ion exchanger 47 of this example embodiment is arranged parallel to the vertical direction of the fuel cell vehicle FCV. The coolant flows into the case 47e from the upper surface of the ion exchanger 47, passes through the ion exchange resin 47h from up to down, and then flows out of the case 47e from the lower surface where the discharge port 47g2 is provided. Conversely, coolant may also be made to flow from below the ion exchange resin 47h to above the ion exchange resin 47h. In this case, the intake / discharge port 47gl serves as a discharge port, and the intake / discharge port 47g2 serves as an intake port.

[0029] The ion exchanger 47 described above may be housed in a forward upper portion, for example, of the fuel cell vehicle FCV (see FIG. 5). Arranging the ion exchanger 47 in a location where it is easily accessible from the outside, such as near an upper portion inside a power compartment (e.g., in a position such as directly under a hood B, for example) facilitates both the work of replacing the ion exchanger 47, and the work of supplying regenerant. When the fuel cell vehicle is a hybrid vehicle (FCHV) that is provided with an internal combustion engine in addition to a fuel cell, the ion exchanger 47 may be provided in the engine compartment.

[0030] The example embodiment of the invention described above is only one example embodiment. The invention is not limited to this example embodiment, but may be carried out in any of a variety of modes without departing from the scope thereof. For example, in the example embodiment described above, the invention is applied to the ion exchanger 47 of the cooling medium conduit system 5 of the fuel cell system 1. Alternatively, however, the structure and configuration described above may also be applied to an ion exchanger in another portion.

Claims

CLAIMS:

1. An ion exchanger comprising:

an ion exchange resin cartridge;

a case within which the ion exchange resin cartridge is housed; and

a lid of the case, to which the ion exchange resin cartridge is removably fixed.

2. The ion exchanger according to claim 1 , wherein

the lid includes a retaining portion which is configured to removably retain the ion exchange resin cartridge to the lid.

3. A fuel cell system comprising:

a fuel cell that generates power by an electrochemical reaction of a reaction gas; an ion exchanger that includes an ion exchange resin cartridge, a case within which the ion exchange resin cartridge is housed, and a lid of the case, to which the ion exchange resin cartridge is removably fixed; and

a conduit that is connected to the fuel cell and in which the ion exchanger is arranged.

4. The fuel cell system according to claim 3, wherein

the fuel cell system is provided in a fuel cell vehicle.

5. The fuel cell system according to claim 4, wherein

the ion exchanger is mounted near an upper portion, in a vertical direction of the fuel cell vehicle, inside a power compartment of the fuel cell vehicle.

6. The fuel cell system according to claim 4 or 5, wherein

the lid is attached to an upper portion, in the vertical direction of the fuel cell vehicle, of the case.

7. The fuel cell system according to any one of claims 4 to 6, wherein:

the conduit includes a first conduit and a second conduit;

the case includes a first port and a second port;

the first conduit is connected to the first port;

the second conduit is connected to the second port; and

the ion exchange resin cartridge is arranged between the first port and the second port in the vertical direction of the fuel cell vehicle.

8. The fuel cell system according to any one of claims 4 to 7, wherein

the lid is provided at a higher position, in the vertical direction of the fuel cell vehicle, than a position where the conduit is provided.

9. The fuel cell system according to any one of claims 3 to 8, wherein