The present invention relates to a structure of a fuel flow board in a fuel cell, and more particularly, to a two-sided fuel flow board having flow field structures formed on its two-sided surfaces, on which fuel cell boards are separately stuck.
Conventionally, flow field structures like trenches are deployed merely on a single side of a fuel flow board in a fuel cell device. Hence, membrane electrode assemblies (MEAs) of a fuel cell board can be stuck only on the single side of the conventional fuel flow board. If such way to combine fuel flow board and fuel cell board is applied to the fuel cell device with flat and large areas, the area of the fuel flow board should be at least as large as the fuel cell board in order to supply fuel for each MEA. It is thus apparent that conventional fuel flow board is not suitable for use in small-sized fuel cell device.
Therefore, an improved two-sided fuel flow board structure is needed to overcome the aforesaid disadvantages.
The primary object of the invention is to provide a two-sided fuel flow board structure having flow field structures formed on the two-sided surfaces of the fuel flow board.
Another object of the invention is to provide a two-sided fuel flow board structure, which reduces the whole volume of a fuel cell device.
In accordance with the objects of the invention, a two-sided fuel flow board structure is provided. The structure includes a plate, top concave portions and bottom concave portions, wherein the top and bottom concave portions are separately formed on an upper surface and a lower surface of the plate, and are disposed corresponding to each membrane electrode assembly of a fuel cell board.
The foregoing aspects, as well as many of the attendant advantages and features of this invention will become more apparent with reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
The injection flow channels 25 and the exhaust flow channels 27 are disposed separately below and above each of the concave portions 23A and 23B. The structures of the injection flow channels 25 and the exhaust flow channels 27 can be designed to be specially deployed and have suitable sizes of cross-sections, such that fuel from the inlet 25A uniformly flow into each concave portion 23A and 23B among the injection flow channels 25. Besides, products formed during electrochemical reaction of the two fuel cell boards 1 are drained out from the outlet 27A through each of the concave portions 23A, 23B and the exhaust flow channels 27.
A support member 29 extended upward from the bottom of each concave portion 23A and 23B, for example, from the center, is almost as high as the side of the concave portion 23A and 23B. The height of the support member 29 can be the same as that of the side of the concave portion 23A and 23B, or be slightly higher than that of the side of the concave portion 23A and 23B. Each support member 29 supports the each corresponding MEA 12 while the substrate 11 of the fuel cell board 1 is stuck on the surface of the fuel flow board 2, so as to prevent the MEA 12 from swelling out of the concave portion 23A and 23B due to heat generated by electrochemical reaction of the MEAs 12, and from decreasing its performance.
The two-sided fuel flow board of the present invention has some advantages and dominant improvements, which are summarized as follows:
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, these are, of course, merely examples to help clarify the invention and are not intended to limit the invention. It will be understood by those skilled in the art that various changes, modifications, and alterations in form and details may be made therein without departing from the spirit and scope of the invention, as set forth in the following claims.