JP2017097958A - Cooling liquid housing container for fuel cell and method for storing cooling liquid for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling liquid housing container for a fuel cell which has a rise suppression effect of electric conductivity of the cooling liquid for the fuel cell after storage and which is capable of maintaining the electric conductivity at an initial stage, and also to provide a method for storing the cooling liquid for the fuel cell using the same.SOLUTION: A cooling liquid housing container 1E for a fuel cell includes: an inner layer 11 composed of a polyester resin: a metal layer 12 composed of aluminum provided on the external surface of the inner layer 11; and an outer layer 13 composed of a polyolefin resin on the outside of the metal layer 12. In a method for storing the cooling liquid for the fuel cell, the cooling liquid housing container for the fuel cell houses the cooling liquid for the fuel cell which contains water and glycols and/or alcohols.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a fuel cell coolant container and a fuel cell coolant storage method using the same. More specifically, the increase in the electrical conductivity of the fuel cell coolant after storage is small, and the fuel cell coolant container that can maintain the initial electrical conductivity, and the fuel cell coolant using the same Related to the storage method.

  A fuel cell is generally configured as a stack having a structure in which a large number of single cells as power generation units are stacked. Since heat is generated from the stack during power generation, a cooling plate is inserted every several cells to cool the stack. A cooling fluid passage is formed in the cooling plate, and the stack is cooled by flowing the cooling fluid through the passage.

  Fuel cell coolant (hereinafter simply referred to as “coolant”) circulates in the stack that is generating power to cool the stack. Therefore, if the electrical conductivity of the coolant is high, the electricity generated in the stack flows to the coolant side and loses electricity, thereby reducing the power generation in the fuel cell. Therefore, pure water having low conductivity, in other words, high electrical insulation is used for the conventional coolant. Further, glycols or alcohols for preventing freezing are usually added to the cooling liquid. When transporting and storing such an aqueous coolant, rust may be generated in a metal container. In order to avoid this harmful effect, the cooling liquid has been conventionally transported and stored in a resin container such as polyethylene.

  The period from manufacture to use of the coolant varies depending on the situation. For example, in a fuel cell vehicle dealer and an automobile repair shop, the coolant is replenished as necessary, so the coolant is stocked. In such a place, the period from the purchase of the coolant to the replenishment may become long, and as a result, the storage of the coolant may take a long time. On the other hand, in the manufacturing site of a fuel cell vehicle or the like, the coolant is usually used within a short period of time. However, it is desirable that the coolant can be stored for a long time from the viewpoint of cost and the like.

  In the course of studying the properties of the coolant after storage, the inventors have newly confirmed that a phenomenon in which the electrical conductivity of the coolant increases during storage is observed. As a result, the present inventors have newly found that there is a technical problem that the power generation in the fuel cell may decrease due to an increase in the electrical conductivity of the coolant due to long-term storage of the coolant. It was.

  As a result of intensive studies focusing on this technical problem, the present inventors have found that an increase in the electrical conductivity of the coolant after storage can be suppressed by using a container having a specific configuration. The present invention has been completed.

  An object of the present invention is to provide a cooling liquid container that can maintain the initial electric conductivity with a small increase in the electric conductivity of the cooling liquid after storage, and a cooling liquid storage method using the same. To do.

  In order to achieve the above object, the present invention provides a cooling liquid container having an inner layer composed of a resin and a metal layer provided on the outer surface of the inner layer, and a method for storing a cooling liquid using the same. The gist.

  According to the cooling liquid storage container and the cooling liquid storage method of the present invention, by suppressing an increase in electrical conductivity of the cooling liquid after storage, a decrease in power generation of a fuel cell using such a cooling liquid is suppressed. be able to.

It is a figure which shows an example of the container of this invention. It is a figure which shows an example of the container of this invention. It is a figure which shows an example of the container of this invention. It is a figure which shows an example of the container of this invention. It is a figure which shows an example of the container of this invention.

  Hereinafter, the cooling liquid storage container and the cooling liquid storage method of the present invention will be described in more detail. As mentioned above, unless otherwise specified, in this specification, “coolant” means “coolant for fuel cell”.

  An example of the coolant container of the present invention is shown in FIG. The container 1a of an example of the present invention includes an inner layer 11 made of a resin and a metal layer 12 provided on the outer surface of the inner layer 11.

  The inner layer 11 is a layer facing the inside of the container 1, and the inner layer surface 111 is in contact with the coolant 2. As long as the effects of the present invention are not impaired, the structure of the inner layer is not particularly limited. The inner layer may be a single layer as shown in FIG. 1, or may be composed of two or more layers (11A and 11B in FIG. 2) as shown in FIG.

  There is no limitation in particular in the kind of resin which comprises the said inner layer. The resin may be a homopolymer or a copolymer. Specific examples of the resin include polyolefin resin (for example, polyethylene, polypropylene), polystyrene, polyester resin (for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN)), polychlorinated. Examples include vinylidene, polyvinyl alcohol resin, polyamide, polyacrylonitrile, and polycarbonate. The polyethylene is high density polyethylene (specific gravity 0.92 to 0.96, deflection temperature under load 130 ° C. or less), low density polyethylene (specific gravity 0.91 to 0.92, deflection temperature under load 100 ° C. or less) ultra low density polyethylene. (Specific gravity is less than 0.9), Linear low density polyethylene (Specific gravity is less than 0.94), Ultra high molecular weight (For example, molecular weight is 1 million or more) Polyethylene may be used.

  The inner layer 11 is made of a resin material, but may contain other components in the inner layer as long as the effects of the present invention are not impaired. Specific examples of the other components include known resin additives. Specific examples of the resin additive include an antioxidant, a light stabilizer, a flame retardant, a plasticizer, a dye, a pigment, and a colorant.

  The thickness of the inner layer 11 is not particularly limited as long as the effects of the present invention are not hindered, and can be various thicknesses as necessary. The thickness of the inner layer is usually 7-30 μm.

  The metal layer 12 is a layer provided on the outer surface of the inner layer 11 (the surface opposite to the inner surface 111). There is no limitation in particular in the kind of metal which comprises the said metal layer. Specific examples of the metal include aluminum.

  As long as the effects of the present invention are not hindered, the structure of the metal layer is not particularly limited. Normally, the metal layer is a single layer as shown in FIG. 1, but it may be composed of two or more layers (12A and 12B in FIG. 3) as shown in FIG. Also, the thickness of the metal layer is not particularly limited as long as the effects of the present invention are not hindered, and various thicknesses can be used as necessary. The thickness of the metal layer is usually 7 to 25 μm.

  The means for forming the metal layer 12 on the outer surface of the inner layer 11 is not particularly limited. For example, a metal foil constituting the metal layer 11 may be formed, and then bonded to the inner layer with an adhesive or other resin film having heat sealability. Alternatively, the metal layer may be formed on the surface of a resin material (for example, a film-like or sheet-like resin material) constituting the inner layer by chemical vapor deposition, plasma vapor deposition, sputtering, or the like.

  Further, there is no particular limitation on the order of forming the inner layer and the metal layer and the container. As described above, after forming a metal layer on one surface of the resin material, a container may be manufactured using the metal layer. Or after manufacturing a hollow container from a resin material previously by injection molding or blow molding, the said metal layer may be formed in the outer surface of this hollow container by plasma vapor deposition etc.

  As long as the container of this invention has the said inner layer and metal layer, there is no limitation in particular in the specific structure. An example of the container of the present invention is shown in FIGS.

  In the container 1a shown in FIG. 1, the inner layer 11 and the metal layer 12 are each one layer, and the metal layer 12 constitutes an outer layer (a layer in contact with the external environment).

  In the container 1b shown in FIG. 2, the inner layer 11 has a multilayer structure (11A and 11B). The metal layer 12 is a single layer, which constitutes the outer layer. In the case where the inner layer 11 has a multilayer structure, at least the innermost layer (the layer in contact with the fuel cell coolant, which corresponds to the inner layer 11A in FIG. 2) is a resin, as long as it does not hinder the operational effects of the present invention. The material constituting the inner layer is not particularly limited. Usually, each layer constituting the inner layer 11 is a resin layer. In this case, the resin material constituting each resin layer is not particularly limited. The resin layers may be the same resin material or different resin materials.

  In the container 1c shown in FIG. 3, the metal layer 12 has a multilayer structure (12A and 12B). When the metal layer has a multilayer structure, the metal material constituting each metal layer is not particularly limited as long as the effects of the present invention are not impaired. The metal layer may be composed of different types of metal layers, or may be composed of the same type of metal layer.

  In the container 1d shown in FIG. 4, the inner layer 11 has a multilayer structure (11A and 11B), and the metal layer 12 has a multilayer structure (12A and 12B). Regarding the inner layer 11 and the metal layer 12, the description regarding the containers 1B and 1C is appropriate.

  A container 1 e shown in FIG. 5 further has another outer layer 13 on the outer surface of the metal layer 12. That is, the container of the present invention may further have another outer layer on the outer surface of the metal layer. The material of the other outer layer is not particularly limited as long as the effects of the present invention are not impaired. The other outer layer is usually a resin layer. Specific examples of the resin constituting the resin layer include resins exemplified as the resin constituting the inner layer. The resin constituting the inner layer and the resin constituting the other outer layer may be the same resin or different resins. Examples of the combination of the resin constituting the inner layer and the resin constituting the other outer layer include a combination of a polyolefin resin and a polyester resin. In the container 1e shown in FIG. 5, the inner layer 11 is usually a polyester resin and the other outer layer 13 is a polyolefin resin, but the reverse is also possible.

  As shown in FIG. 5A, the other outer layer may be a single layer, or may have a multilayer structure (13A and 13B) as shown in FIG. 5B. In the case where the other outer layer has a multilayer structure, the material constituting each layer is not particularly limited as long as the effects of the present invention are not impaired. Usually, each layer is a resin layer, but may be a combination of a resin layer and a metal layer.

  In the container of the present invention, when the inner layer, the metal layer, and the other outer layer have a multilayer structure, the method for integrating the layers is not particularly limited. For example, the layers constituting the multilayer structure can be integrated with an adhesive or other resin film having heat sealability. In this case, exactly, an adhesive layer or a heat-sealable resin layer is formed between the layers constituting the multilayer structure, but in FIGS. 1 to 5, such an adhesive layer or a heat-sealable resin layer is described. Is omitted. That is, the container illustrated in FIGS. 1 to 5 includes an embodiment having an adhesive layer or a heat-sealable resin layer at least between the layers of the multilayer structure.

  There is no particular limitation on the size of the container of the present invention. The container of the present invention can be variously sized depending on the application.

  In the storage method of the present invention, the cooling liquid is accommodated in the container of the present invention. In the “storage” of the present invention, not only when the cooling liquid is stored as it is (in a mode in which the cooling liquid is not used as a cooling liquid) (simple storage), but also when the liquid is stored while being used as a cooling liquid (use storage). Including both. For example, the case where the container of the present invention is mounted on a vehicle together with a vehicle-mounted fuel cell and stored while using the coolant as the coolant is included.

  The storage method of the present invention is not particularly limited in specific storage method and storage conditions as long as the cooling liquid is accommodated in the container of the present invention. As the storage method and storage conditions, appropriate methods and conditions can be set as necessary. Moreover, there is no limitation in particular also in the composition of the said cooling fluid, For example, a well-known cooling fluid can be used. Specific examples of the cooling liquid include water (ion exchange water and the like) or a cooling liquid containing water (ion exchange water and the like) and glycols and / or alcohols.

  The container and storage method of the present invention can be freely modified within the scope described in the claims.

  Hereinafter, the present invention will be described specifically by way of examples. In addition, this invention is not limited to the form shown in the Example. The embodiment of the present invention can be variously modified within the scope of the present invention depending on the purpose and application.

  Table 1 shows the compositions of the containers of Examples 1-2 and Comparative Example. The capacity of each container is 2L. The container of Example 1 is composed of an inner layer of PET (polyethylene terephthalate) 12 μm, a metal layer of aluminum foil 9 μm, an outer layer of ONY (nylon) 15 μm, and LLDPE (linear low density polyethylene) 160 μm (the outermost layer is the outer layer). LLDPE). The container of Example 1 was formed by laminating each layer by a dry lamination method. In the container of Example 2, the inner layer is made of PET 12 μm, the metal layer is made of aluminum foil, the outer layer is made of PET, ONY 25 μm, and LLDPE 180 μm (the outermost layer is LLDPE, and the metal layer is in contact with PET). The container of Example 2 was formed by using aluminum vapor-deposited PET in which aluminum was vapor-deposited on PET (thickness 12 μm), and laminating the layers constituting the outer layer and the inner layer by a dry laminating method.

  In each of the containers of Examples 1 and 2 and Comparative Example 1, 2 L of a coolant for a fuel cell (manufactured by CCI, ethylene glycol / ion exchange water) was accommodated. Subsequently, this cooling liquid was preserve | saved on the conditions of temperature 50 degreeC, and the electrical conductivity (microS / cm) after 168, 336, 504, and 672 hours was measured with conductivity meter ES-12 (made by Horiba, Ltd.). . The results are shown in Table 1.

  From Table 1, it can be seen that the electrical conductivity of the coolant stored in the conventional resin container (comparative example) is increased during storage. In particular, at 168 hours (7 days) after storage, the electrical conductivity has already increased by about 4 times the initial value, and at 672 hours (28 days), has increased to 8 times the initial value. On the other hand, the coolant stored in the containers of Examples 1 and 2 included in the container of the present invention still maintains the initial electrical conductivity even at 672 hours (28 days) after storage. Therefore, it can be seen that the container of the present invention is remarkably excellent in the effect of suppressing the increase in the electrical conductivity of the coolant during storage, and is suitable for storing the coolant.

1a to 1e; fuel cell coolant container, 11; inner layer, 111; inner layer surface, 12; metal layer, 13; other outer layer, 2; fuel cell coolant.

Claims (5)

  A fuel cell coolant container having an inner layer made of resin and a metal layer provided on the outer surface of the inner layer.   The fuel cell coolant container according to claim 1, further comprising another layer outside the metal layer.   The fuel cell coolant container according to claim 1 or 2, wherein the resin is a polyolefin resin or a polyester resin.   The fuel cell coolant storage container according to any one of claims 1 to 3, wherein water or a fuel cell coolant containing water and glycols and / or alcohols is stored.   A storage method for a fuel cell coolant, wherein the fuel cell coolant is stored in the storage container according to claim 1.

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