Patent Application
20060188770
The present invention relates to a structure of flow channels layer used in a fuel cell, and more particularly, to a flow field board of a fuel cell, which is made of composite material and can radiate heat. Thereby, heat within the fuel cell is conducted to the flow field board and radiated out.
Conventional flow field boards of fuel cells usually put more emphasis on the structure of flow channels to smoothly flow fuel into membrane electrode assemblies (MEAs) through the flow channels. In addition, the conventional flow field board is made from only one kind of substrate.
Therefore, an improved compound flow field board is provided to overcome the foresaid disadvantages, which could raise the radiating heat function.
It is a primary object of the invention to provide a compound flow field board, which can radiate heat. Thereby, heat within the fuel cell is conducted to the compound flow field board and is radiated out.
In accordance with the object of the invention, an improved compound flow field board for a fuel cell is provided. The compound flow field board comprises at least a first region including a substrate made of a heat-conductive material, wherein the first region is disposed corresponding to a membrane electrode assembly, and a second region including a substrate made of an adhesive material, wherein the second region is connected with the first region such that the compound flow field board becomes a one-piece structure. Also, the first region comprises a projection protruded into the second region.
The foregoing aspects, as well as many of the attendant advantages and features of this invention will become more apparent by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
Each first region 11 of the compound flow field board 10 is positioned corresponding to a membrane electrode assembly (MEA) (not shown). The first region 11 includes at least a concave portion 111 disposed corresponding to the MEA. Accordingly, fuels within the concave portion 111, such as liquid fuel like methanol solution, gaseous fuel like hydrogen, anode fuel, and cathode fuel, flow into the MEA, initializing electrochemical reaction and generating heat. Because the first region 11 conducts heat well, the temperature of the fuel in the concave portion 111 can be distributed uniformly, and heat can be radiated out of the MEA.
A projection 113 disposed on each first region 11 is protruded into the second region 13. Heat within the concave portion 111 is conducted to the projection 113, and hence heat produced by the MEA is radiated away from the compound flow field board 10 completely. Referring to
With reference to
External fuel injected from the inlet 131 flows into the injection flow channel 133, the concave portion 111 and the MEA sequentially. As a result, the MEA performs an electrochemical reaction to generate power. Fuel in the concave portion 111 and products generated during electrochemical reaction flow into the exhaust flow channel 137, and are drained out from the outlet 135.
The first region 11 may be made from an acid-resisting metal substrate or an anticorrosive metal substrate, such as gold (Au). Or, the surface of the first region 11 may be further treated by an acid-resisting process or an anticorrosive process to protect the first region 11 from being damaged by fuel or products of electrochemical reaction. The acid-resisting process is performed, for example, by coating Teflon onto the whole surface of the first region 11. The anticorrosive process is performed, for example, by covering a lamina of anticorrosive conductive material like Au onto the surface of the first region 11. Hence, the resultant compound flow field board 10 is acid-resisting or anticorrosive.
Since the second region 13 is made from a plastic substrate, a ceramic substrate, a printed circuit substrate, or a polymer plastic substrate, its surface may serve to deploy layouts of electrical circuits and to dispose a plurality of electrical devices thereon. Besides, another third substrate 30 can be used as well with reference to
To sum up, the compound flow field board possesses the advantages as following:
1. It utilizes well heat-conductive material to uniformly distribute the temperature of anode fuel or cathode fuel, and radiates heat out by means of protruded portions and radiation components. Thereby, the efficiency of power generation in a fuel cell system is increased and the shelf life of MEA is extended;
2. Furthermore, it utilizes well adhesive material to connect the flow field board with the current collection layer in a sealed way. Therefore, the compound flow field board has utility; and
3. Moreover, it s feasible to form an intelligent flow field board by combining a printed circuit substrate with an circuit layout disposed thereon.
The preferred embodiment disclosed is only for illustrating the present invention, and not for giving any limitation to the scope of the present invention. It will be apparent to those skilled in this art that various modifications or changes can be made to the present invention without departing from the spirit and scope of this invention. Accordingly, all such modifications and changes also fall within the scope of protection of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 094202911 | Feb 2005 | TW | national |
