Patent Application
20080026278
These and other aspects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which:
Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings.
Hereinbelow, one embodiment of the present invention is described in detail with reference to the accompanying drawings.
As shown in
A transversal sectional view is shown in
As shown in
Moreover,
Moreover, by inserting the cartridge 20 into the cartridge slot portion 51 of the electronic equipment 50 and connecting the connection port 30 of the cartridge 20 to the inlet 11 of the power generation module 1, an amount of supply of the liquid fuel sufficient for generating electric energy necessary for power generation in the power generation module 1 can be supplied from the cartridge 20. The liquid fuel cannot be supplied before the connection is made or after the connection is released.
In this case,
Moreover, the present first embodiment uses methanol (or a methanol aqueous solution) as the liquid fuel 23, and the fuel cell system 101 is the direct type methanol fuel cell (DMFC (Direct Methanol Fuel Cell).
The principle of operation of the electric power generation in such a fuel cell system is described here. In the fuel cell system 101, electric power generation is achieved by supplying methanol from the equipped cartridge 20 to the power generation module 1 and directly taking protons out of the methanol in the power generation module 1.
In concrete, the power generation module 1 has an anode (fuel pole), a cathode (air pole) and a membrane electrode assembly. In the power generation module 1, the anode causes a reaction (anodic reaction) of extracting protons and electrons by oxidizing the supplied methanol. The extracted electrons move to the anode through an external circuit that electrically connects the anode with the cathode, while the protons move to the cathode through the membrane electrode assembly. Moreover, the cathode causes a reaction (cathodic reaction) of generating water by reducing externally supplied oxygen and the protons that have moved from the anode through the membrane electrode assembly by the electrons that have flowed through the external circuit. Electric power generation is thus carried out by flowing electrons through the external circuit by causing the oxidizing reaction at the anode and causing the reducing reaction at the cathode.
Moreover, as shown in
In this case, the cobalt chloride 25 used as the coloring agent has a characteristic that its color is changed by a solvent. That is, the cobalt chloride aqueous solution is colored in pink when the solvent is water, and the methanol solution of cobalt chloride is colored in red when the solvent is methanol.
By taking advantage of the property of the cobalt chloride 25, the colorless transparent liquid fuel 23 is to be colored in red as a consequence of reaction with the cobalt chloride 25 when the methanol of the liquid fuel 23 leaks from the liquid fuel holding section 22. Although the case where the cobalt chloride 25 is used as the coloring agent of the leaked methanol is described in the present first embodiment, the coloring agent is not limited only to the case. Instead of the case, for example, aqueous ink or the like can be used as the coloring agent. One that has the function of coloring the leaked liquid fuel 23 in contact with the leaked liquid fuel 23 is possessed can be used as the coloring agent. However, in selecting the coloring agent, the safety at the time of the change in color by contact needs to be considered.
Moreover, in order to confirm the fact that the liquid fuel 23 has been colored as the result of the leakage of the liquid fuel 23 from the liquid fuel holding section 22, a transparent portion 28 of one example of the visual recognition window is provided at the casing 21 that is the packaging of the cartridge 20 as shown in
As a result, when the liquid fuel 23 leaks from the liquid fuel holding section 22, the leaked liquid fuel 23 enters the coloring agent holding section 24 and colored in red in contact with the cobalt chloride 25. Therefore, by visually recognizing the change in color through the transparent portions 28 and 60, the leakage of the liquid fuel 23 can be detected. In the case, the use of the electronic equipment 50 is stopped and the user can be informed of the necessity of the replacement of the cartridges 20 since it might cause the troubles of leakage, deterioration of the electronic components, contact failure and so on if the electronic equipment 50 is continuously used as it is.
In present first embodiment, a leakage detecting unit for carrying out the detection (detection by visual observation) of the leakage of liquid fuel 23 is constituted of the cobalt chloride 25 and the coloring agent holding section 24.
Although the case where the transparent portion 28 that allows the visual recognition of the color of the cobalt chloride 25 held in the coloring agent holding section 24 is provided in a part of the casing 21 of the cartridge 20 has been described in the present first embodiment, it is acceptable to provide the transparent portion 28 roughly along the entire periphery of the casing 21 or form the casing 21 itself of a transparent material allowing the inside to be visually recognized instead of the above case. In such a case, the state of the color of the cobalt chloride 25 held in the coloring agent holding section 24 can be visually recognized in every position, and even a minute leakage can be detected swiftly and easily. When the transparent portion 28 is provided in a part of the casing 21 as described above, it is effective to place the transparent portion in a location of a high possibility of leakage.
Moreover, although the case where the powdered cobalt chloride 25 is held in the coloring agent holding section 24 of the cartridge 20 has been described according to the above description, it may be a case where a cobalt chloride aqueous solution is held as the coloring agent instead of the above case. Such a cobalt chloride aqueous solution has a pink color and has the characteristic that its color is changed into a red color by reacting with the methanol of the liquid fuel 23.
Therefore, when the liquid fuel 23 leaks from the liquid fuel holding section 22, the leaked liquid fuel 23 and the cobalt chloride aqueous solution are changed in color into a red color to allow the color change to be visually recognized. Furthermore, when the cobalt chloride aqueous solution itself leaks from the casing 21 of the cartridge 20, the leakage can be detected swiftly and easily due to the fact that the cobalt chloride aqueous solution has a pink color. Moreover, by virtue of the change in color as described above, the leaked liquid can easily be identified.
Particularly, when the leaked liquid fuel 23 has a minute amount, it is presumably the case where a change in color sufficient for visual recognition does not occur in the case of the powdered cobalt chloride 25. However, by using the cobalt chloride aqueous solution that already has a pink color as the coloring agent, the pink liquid leaked from the cartridge 20, i.e., the cobalt chloride aqueous solution can be visually recognized reliably and easily even when a minute amount of leaked liquid fuel 23 leaks and a sufficient change in color does not occur. Therefore, even a minute amount of leakage can reliably be detected.
Although the leakage can be detected also by preliminarily coloring the liquid fuel 23 itself, continuously supplying the colored liquid fuel to the electrolytic membrane used in the fuel cell might possibly impair the function and characteristics of the electrolytic membrane, and this is unfavorable. Moreover, it is preferable that the leakage can swiftly be detected before the liquid leaks from cartridge 20 in the electronic equipment 50 that refuses the leakage of the liquid. Also from the above viewpoint, it can be regarded as effective that the construction in which the liquid fuel 23 itself is held in the colorless transparent state and is not colored until the leakage occurs, and the cartridge 20 has the dual structure of the liquid fuel holding section 22 for holding the liquid fuel 23 and the casing 21 to reduce the possibility of the occurrence of liquid leakage to the outside of the cartridge 20.
Moreover, the case where the cobalt chloride 25 is placed roughly covering the entire outer peripheral portion of the liquid fuel holding section 22 has been described. However, instead of the construction, it may be a case where the cobalt chloride 25 is placed only at a part of the outer peripheral portion. Depending on the structural features of the cartridge 20, there might be a portion where the liquid fuel easily leaks. In such a case, the leakage can effectively be detected by placing the cobalt chloride 25 only at the portion.
Moreover, it may be a case where the placement of the cartridge slot portion 51 is determined so that heat generated by driving the electronic equipment 50 is conducted to the cartridge 20 inserted in the cartridge slot portion 51 in the electronic equipment 50 shown in
By thus determining the placement of the cartridge slot portion 51 in the electronic equipment 50, the generated heat can positively be conducted to the cartridge 20, and the temperature of the cobalt chloride 25 held in the coloring agent holding section 24 (or the liquid fuel 23 held in the liquid fuel holding section 22) can be raised. By thus keeping the cobalt chloride 25 at the raised temperature as described above, the reaction of methanol of the liquid fuel 23 with the cobalt chloride 25 can be promoted further than in the case of normal temperature when, for example, the leakage of the liquid fuel 23 occurs, and the change in color caused by the reaction can be made remarkable. Therefore, even when the leakage of a minute amount of liquid fuel occurs, the leakage can be detected by making the color change remarkable. It is preferable that the cartridge slot portion is determined to be located in a portion of a highest temperature or a portion where a temperature sufficient for promoting the reaction is obtained.
Moreover, methanol has the characteristics of not only inflammability but also toxicity to the human body and has the characteristic that it is easily absorbed by inhalation, exposure to the skin and the like. Therefore, sufficient care is necessary for storage and handling. In contrast to this, cobalt chloride is used for silica gel in the products on the market. The silica gel is a substance that is used as a safe and harmless desiccant, recognized as a food additive and basically harmless to the human body merely by a lick. Therefore, even if the cobalt chloride for detecting the leakage of methanol leaks, it is safer than in the case where methanol leaks.
The present invention is not limited to the first embodiment but practicable in various modes. For example,
As shown in
The cobalt chloride paper 26 used here improves its waterproof property with the outside thereof provided with a laminate of polyethylene. Polyethylene is a safe material that is used for laminate layers on both sides of paper generally used for a milk carton and is constituted only of hydrogen and carbon and excellent in the aspect of the waterproof property. By providing laminate layers of polyethylene on the outside of the cobalt chloride paper 26, the cobalt chloride paper 26 is colored in red by the infiltration of the liquid fuel 23 leaked from the liquid fuel holding section 22 from inside the cobalt chloride paper 26. Furthermore, since the outside of the cobalt chloride paper 26 is excellent in the aspect of the waterproof property, the liquid fuel 23 leaked from the liquid fuel holding section 22 can be prevented from leaking out of the cartridge 20.
As described above, by using the cobalt chloride paper 26 of which the outside is laminated with polyethylene as the coloring agent, the leakage of the liquid fuel 23 from the liquid fuel holding section 22 can be detected on the basis of the change in the color of the cobalt chloride paper 26. Furthermore, the leakage of the liquid fuel 23 to the outside of the cartridge 20 can be suppressed.
Next,
The fuel cell system 111 of the present third embodiment differs from the fuel cell system 101 of the first embodiment in that it has a construction in which water (or emission matter) due to electric power generation is collected in the cartridge 80. In concrete, as shown in
In the cartridge 80 that has the construction, by bringing the liquid fuel 23 leaked from the liquid fuel holding section 82 or the water 87 leaked from the product holding section 86 in contact with the cobalt chloride 25 held in the coloring agent holding section 84, the leaked liquid can be changed in color. In concrete, by reacting methanol of the liquid fuel 23 with the cobalt chloride 25, the methanol can be colored from colorless to red. Moreover, by reacting the water 87 with the cobalt chloride 25, the water can be colored from colorless to pink. As described above, the coloring is varied depending on when the cobalt chloride 25 reacts with the methanol of the liquid fuel 23 or when the cobalt chloride 25 reacts with the water 32. Therefore, the liquid leaked from the cartridge 80 can be identified by the color. Moreover, the fact that the kind of the thus-leaked liquid can be identified becomes effective for taking appropriate measures also because the anti-leakage measures are different between methanol that has inflammability and toxicity and water that has neither one of them.
Particularly, in the electronic equipment equipped with the fuel cell system 111 as a power source, even the leakage of water generated by electric power generation causes short circuit, contact failure and so on besides the liquid fuel 23. Therefore, collection of water to the cartridge 80 provided with the anti-leakage measures of the liquids becomes effective.
Moreover, it may be a case where a construction in which the powdered cobalt chloride 25 held in the coloring agent holding section 84 is formed into a cobalt chloride aqueous solution colored in pink is adopted by introducing part of the water 87 collected in the product holding section 86 through the water outlet 92 into the coloring agent holding section 84 in place of the construction of the cartridge 80 as described above. By using the cobalt chloride aqueous solution as the coloring agent, the effect that the minute leakage as described in connection with the first embodiment can reliably be detected can be obtained. In addition, since the powdered cobalt chloride 25 is held in the cartridge 80 before the fuel cell system 111 is equipped with the cartridge 80 and not formed into the cobalt chloride aqueous solution until the equipment of the cartridge 80, the risk of the leakage of the cobalt chloride 25 during the transportation of the cartridge 80 can be further reduced.
As a concrete construction (construction of a modification example of the third embodiment), a construction, in which a coloring agent holding section 184 and a product holding section 186 have an integrated structure and the water 87 collected into a product holding section 186 through the water outlet 92 is introduced into the coloring agent holding section 184 of the integrated structure as it is as in a cartridge 180 of which the schematic sectional view is shown in
Next,
As shown in
The absorber 128 is formed of sodium polyacrylate, which is generally used for, for example, a paper diaper and the like. A synthetic polymer for improving the water absorbing property and the water-holding capacity is the water absorbing polymer or polymer absorber, which increases the water absorbing property by providing many hydrophilic parts in large molecules. The most general one is sodium polyacrylate, which is formed into a polymer by binding numbers of molecules of acrylic acid by reaction. This is a white powder before absorbing water and is able to be put into a soft transparent state with water added and to absorb and retain water of an amount about 500 times its weight.
Moreover, by providing the absorber 128 at the connection port of the power generation module 1 and the cartridge 120 and in the neighborhood of the liquid fuel inlet 11, where the probability of the occurrence of liquid leakage is high, the leakage of the liquid fuel to the outside of the cartridge 120 can be reduced as far as possible.
Although the cartridge 120 has the construction in which the liquid fuel 23 generated from the harmful methanol is absorbed by the absorber 128 so as not to leak, the absorber 128 merely absorbs the leaked liquid fuel 23, and the absorber 128 constituted of sodium polyacrylate is solidified by absorbing the liquid fuel 23 with the methanol aqueous solution internally retained.
Therefore, even if the leaked methanol is solidified and retained by the absorber 128, the methanol is not rendered harmless and remains intact unless the cartridge 120 is replaced. Therefore, if the cartridge 120 is damaged and the absorber 128 leaks to the outside, the possibility of exerting a bad influence on the human body and the environment cannot be denied.
Therefore, the absorber 128 is colored by coloring the liquid fuel 23 with the cobalt chloride 25 when it leaks and absorbing the colored liquid fuel 23 by the absorber 128. The cartridge 120, which allows the confirmation of the leakage of the liquid fuel 23 in the early stage by the change in the color of the absorber 128 or the change in the color of the leaked liquid fuel 23 and is excellent in the aspects of safety and environment, can be provided.
The absorber 128 may be placed locally in a position of a higher possibility of leakage in the liquid fuel holding section 22 instead of being provided on the entire surface of the outer peripheral portion of the liquid fuel holding section 22. Particularly, in a cartridge 120 that needs to be reduced in size and thickness for the achievement of satisfactory portability, the reduction in the size and thickness can be achieved with the function of absorbing the leaked liquid fuel by locally placing the absorber 128 as described above.
Next,
As shown in
In the fuel cell system 131 of the construction, when the cartridge 140 is attached to or detached from the cartridge mounting portion 151 of the electronic equipment 150, the liquid fuel 23 might possibly leak from the connection port, i.e., the inlet 11. In the case, by coloring the leaked liquid fuel 23 with the cobalt chloride 25 provided in the neighborhood of the portion connected to the cartridge 20 in the cartridge mounting portion 151 of the electronic equipment 150, the leakage can be visually detected. Furthermore, by absorbing the leaked liquid fuel 23 by the absorber 128 provided at the cartridge mounting portion 151 of the electronic equipment 150, the diffusion of the leaked liquid fuel can be suppressed. By providing the absorber 128 at the cartridge holding portion 151 of the electronic equipment 150 by an amount sufficient for absorbing the liquid fuel even when the liquid fuel holding section 22 of the cartridge 140 is fully filled with the liquid fuel 23, the leakage of the liquid fuel 23 to the outside of the electronic equipment 150 can be prevented.
It is to be noted that, by properly combining the arbitrary embodiments of the aforementioned various embodiments, the effects possessed by them can be produced.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
The disclosure of Japanese Patent Application No. 2004-140651 filed on May 11, 2004 including specification, drawing and claims are incorporated herein by reference in its entirety.
The present invention allows the discovery of the leakage of the held liquid fuel visually, swiftly and easily in the fuel cell system that generates electric power by electrochemically converting the chemical energy owned by the liquid fuel into electrical energy and is useful in the point that the occurrence of failures and the like attributed to the leakage in the electronic equipment or the like in which the fuel cell system is employed can be avoided. Moreover, the present invention is useful in the aspects of environment and safety since the influence on the environment can be reduced by taking appropriate measures by the discovery of the leakage in the early stage.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-140651 | May 2004 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP05/08298 | 5/2/2005 | WO | 00 | 2/8/2006 |
