This application claims the priority benefit of Chinese application serial no. 201010002982.X, filed on Jan. 15, 2010. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
1. Field of the Invention
The invention generally relates to a hydrogen generation device and a fuel cell with the hydrogen generation device, and more particularly, to a hydrogen generation device using solid fuel and a fuel cell with the hydrogen generation device.
2. Description of Related Art
A fuel cell is an electricity generation apparatus that directly converts chemical energy into electrical energy. Compared to the conventional electricity generation techniques, the fuel cell offers lower pollution, lower noise, higher energy density, and higher energy conversion efficiency, and therefore it is a very promising clean energy source. Fuel cells may be applied in portable electronic products, home electricity generation systems, transportation vehicles, military equipments, the space industry, and small-scale electricity generation systems, etc.
Different fuel cells have different applications according to the operating principles and operating environments. Proton exchange membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFC) are mostly applied to portable power sources. Both PEMFC and DMFC may actuate at low temperature and use proton exchange membranes for conducting protons. According to the operating principle of such a fuel cell, an oxidation reaction for hydrogen is carried out in the anode catalyst layer to produce hydrogen ions H+ and electrons e− (the operating principle of PEMFC), or an oxidation reaction for water or methanol is carried out in the anode catalyst layer to produce hydrogen ions H+, carbon dioxide (CO2), and electrons e− (the operating principle of DMFC), wherein the hydrogen ions H+ are conducted by the proton exchange membrane to the cathode, while the electrons e− are transmitted by an external circuit to the load before they are conducted to the cathode. Herein a redox reaction between the oxygen supplied to the cathode and the hydrogen ions H+ and electrons e− is carried out in the cathode catalyst layer and water is produced. The hydrogen supplied to the anode may be obtained through a solid NaBH4 hydrogen storage technique, wherein water is added into solid NaBH4, and the two react with each other to produce hydrogen.
U.S. Pat. No. 6,746,496, U.S. Pat. No. 7,306,780, and U.S. Pat. No. 7,427,302 respectively disclose related techniques.
The reaction between solid NaBH4 and water is a one-off reaction, and once the reaction starts, it won't stop until the solid NaBH4 or water completely runs out. Thereby, the problem of how to carry out the reaction in multiple stages has to be resolved.
Accordingly, the invention is directed to a hydrogen generation device, wherein the reaction between a solid fuel and water is carried out in multiple stages.
The invention is directed to a fuel cell, wherein the reaction between a solid fuel and water is carried out in multiple stages in a hydrogen generation device of the fuel cell.
Additional aspects and advantages of the invention may be further understood from the description that follows.
According to an embodiment of the invention, a hydrogen generation device adapted to a fuel cell is provided. The hydrogen generation device includes a draft tube, a plurality of containing grooves, a plurality of water absorbing structures, a plurality of capillary structures, and a water supply device. The wall of the draft tube has a plurality of openings. The containing grooves are disposed below the draft tube and respectively aligned with the openings, wherein each of the containing grooves is capable of containing a solid fuel. The water absorbing structures are respectively disposed in the containing grooves, wherein each of the water absorbing structures is located between the corresponding opening and the corresponding solid fuel. The capillary structures are alternatively disposed on the internal wall of the draft tube, wherein each of the capillary structures is located between the two adjacent openings. The water supply device is disposed at one end of the draft tube. The water supply device is capable of supplying a liquid fuel into the draft tube, and the liquid fuel is capable of sequentially entering the containing grooves through the openings to sequentially react with the solid fuels and produce hydrogen.
According to an embodiment of the invention, a fuel cell including a hydrogen generation device, a fuel cell stack, and a guiding structure is provided. The hydrogen generation device includes a draft tube, a plurality of containing grooves, a plurality of water absorbing structures, a plurality of capillary structures, and a water supply device. The wall of the draft tube has a plurality of openings. The containing grooves are disposed below the draft tube and respectively aligned with the openings, wherein each of the containing grooves is capable of containing a solid fuel. The water absorbing structures are respectively disposed in the containing grooves, wherein each of the water absorbing structures is located between the corresponding opening and the corresponding solid fuel. The capillary structures are alternatively disposed on the internal wall of the draft tube, wherein each of the capillary structures is located between the two adjacent openings. The water supply device is disposed at one end of the draft tube. The water supply device is capable of supplying a liquid fuel into the draft tube, and the liquid fuel is capable of sequentially entering the containing grooves through the openings to sequentially react with the solid fuels and produce hydrogen. The guiding structure is connected between the hydrogen generation device and the fuel cell stack and capable of guiding the hydrogen produced by the reaction between the solid fuels and the liquid fuel to the fuel cell stack.
As described above, embodiments of the invention have at least one of following advantages. Instead of reacting with the solid fuels in all the containing grooves at the same time, the liquid fuel supplied by the water supply device sequentially enters the containing grooves and sequentially reacts with the solid fuels in the containing grooves to produce hydrogen. Thus, a user may control the solid fuels to sequentially react with the liquid fuel continuously or stop the liquid fuel from running in the draft tube (so that some solid fuels do not react with the liquid fuel) by turning on/off the water supply device or adjusting the water supply power of the water supply device, so as to achieve a staged reaction. In addition, the water absorbing structures disposed between the openings and the solid fuels allow the liquid fuel to slowly enter the containing grooves and steadily react with the solid fuels, and the water absorbing structures also prevent the water solution produced by the reaction between the solid fuels and the liquid fuel from entering the draft tube. Moreover, the capillary structure disposed between the two adjacent openings buffers the running liquid fuel so that the liquid fuel is prevented from entering another containing groove before it has completely reacted with the solid fuel in the current containing groove.
Other objectives, features and advantages of the invention will be further understood from the further technological features disclosed by the embodiments of the invention wherein there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” etc., is used with reference to the orientation of the Figure(s) being described. The components of the invention may be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. On the other hand, the drawings are only schematic and the sizes of components may be exaggerated for clarity. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. Similarly, the terms “facing,” “faces” and variations thereof herein are used broadly and encompass direct and indirect facing, and “adjacent to” and variations thereof herein are used broadly and encompass directly and indirectly “adjacent to”. Therefore, the description of “A” component facing “B” component herein may contain the situations that “A” component directly faces “B” component or one or more additional components are between “A” component and “B” component. Also, the description of “A” component “adjacent to” “B” component herein may contain the situations that “A” component is directly “adjacent to” “B” component or one or more additional components are between “A” component and “B” component. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
The wall of the draft tube 110 has a plurality of openings 112. The containing grooves 120a-120e are disposed below the draft tube 110 and respectively aligned with the openings 112, wherein each of the containing grooves 120a-120e is capable of containing a solid fuel 50. In the embodiment, the solid fuel 50 may be solid NaBH4. However, the invention is not limited thereto, and the solid fuel 50 may also be other types of solid fuels. The water absorbing structures 130 are respectively disposed in the containing grooves 120a-120e, wherein each of the water absorbing structures 130 is located between the corresponding opening 112 and the corresponding solid fuel 50. The capillary structures 140 are alternatively disposed on the internal wall of the draft tube 110, wherein each of the capillary structures 140 is located between two adjacent openings 112. The water supply device 150 is disposed at one end of the draft tube 110.
On the other hand, if the user wants the hydrogen generation device 100 to continue supplying hydrogen after the solid fuel 50 in the containing groove 120a has completely reacted with the liquid fuel 60, the user controls the water supply device 150 to continue supplying liquid fuel 60 so that the liquid fuel 60 flows along the draft tube 110 and enters the containing groove 120b through the next opening 112 to react with the solid fuel 50 in the containing groove 120b and produce hydrogen. Similarly, the liquid fuel 60 is further controlled to sequentially enter the containing groove 120c, the containing groove 120d, and the containing groove 120e to react with the solid fuels 50 therein and produce hydrogen. By this way, the user may control the solid fuels 50 to react with the liquid fuel 60 sequentially and continuously or stop the liquid fuel 60 from running in the draft tube 110 (so that some solid fuels 50 do not react with the liquid fuel 60) by turning on/off the water supply device 150 or adjusting the water supply power of the water supply device 150. Thereby, a staged reaction is achieved. It should be noted that the reaction efficiency is also increased by respectively placing the solid fuels 50 in the containing grooves 120a-120e to respectively react with the liquid fuel 60.
To be specific, the water absorbing structures 130 disposed between the openings 112 and the solid fuels 50 allow the liquid fuel 60 to slowly enter the containing grooves 120a-120e and steadily react with the solid fuels 50, which also prevent the water solution produced by the reaction between the solid fuels 50 and the liquid fuel 60 from entering the draft tube 110 or contaminating the liquid fuel 60 in the draft tube 110. In addition, the capillary structure 140 disposed between every two adjacent openings 112 buffers the running liquid fuel 60 so that the liquid fuel 60 is prevented from entering another containing groove (for example, the containing groove 120b) before it has completely reacted with the solid fuel 50 in the current containing groove (for example, the containing groove 120a). It should be noted that these capillary structures 140 are alternatively disposed so that the liquid fuel 60 is prevented from being conducted from one capillary structure 140 to another capillary structure 140. Moreover, the water supply device 150 in the embodiment may be a water pump. The water pump provides power with different levels to the hydrogen generation device 100 of the embodiment, such that it is more precise to control the range where the liquid fuel 60 flows to in the draft tube 110.
The water absorbing structures 130 in the embodiment may be porous structures. The hydrogen produced by the reaction between the solid fuels 50 and the liquid fuel 60 is exhausted from the containing grooves 120a-120e through the water absorbing structures 130 and the openings 112 and conducted to the anode of the fuel cell. However, approaches for exhausting the hydrogen are not limited in the invention, and in other embodiments, the hydrogen may also be exhausted through other methods, as the one described below with reference to
The hydrogen generation device of embodiments described above may be applied to a fuel cell for supplying hydrogen required by the reaction at the anode of the fuel cell. The application of the hydrogen generation device 100 in
As described above, embodiments of the invention have at least one of following advantages. Instead of reacting with the solid fuels in all the containing grooves at the same time, the liquid fuel supplied by the water supply device sequentially enters the containing grooves and sequentially reacts with the solid fuels in the containing grooves to produce hydrogen. Thus, a user may control the solid fuels to sequentially react with the liquid fuel continuously or stop the liquid fuel from running in the draft tube (so that some solid fuels do not react with the liquid fuel) by turning on/off the water supply device or adjusting the water supply power of the water supply device, so as to achieve a staged reaction. In addition, the water absorbing structures disposed between the openings and the solid fuels allow the liquid fuel to slowly enter the containing grooves and steadily react with the solid fuels, and the water absorbing structures also prevent the water solution produced by the reaction between the solid fuels and the liquid fuel from entering the draft tube. Moreover, the capillary structure disposed between the two adjacent openings buffers the running liquid fuel so that the liquid fuel is prevented from entering another containing groove before it has completely reacted with the solid fuel in the current containing groove.
Additionally, the water absorbing structures may be porous structures such that the hydrogen produced by the reaction between the solid fuels and the liquid fuel may be exhausted through the water absorbing structures. Moreover, holes and waterproof breathable membranes for covering the holes may be further disposed in the containing grooves such that the hydrogen may be exhausted through the waterproof breathable membranes. Furthermore, covers may be disposed beside the openings, and the covers are pushed by the expanded water absorbing structures to seal the openings, so that the liquid fuel is prevented from entering the containing groove containing enough liquid fuel and directly flows towards the next containing groove.
The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like does not necessarily limit the claim scope to a specific embodiment, and the reference to particularly preferred exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. The abstract of the disclosure is provided to comply with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.
Number | Date | Country | Kind |
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201010002982.X | Jan 2010 | CN | national |