Manifold for a fuel cell system

#This invention relates to a manifold for a fuel cell system, and more particularly relates to a manifold for mounting peripherals and piping to fuel cell stacks.

#Fuel cells have been proposed as a clean, efficient and environmentally friendly source of power which can be utilized for various applications. A fuel cell is an electrochemical device that produces an electromotive force by bringing the fuel (typically hydrogen) and an oxidant (typically air) into contact with two suitable electrodes and an electrolyte. A fuel, such as hydrogen gas, for example, is introduced at a first electrode, i.e. anode where it reacts electrochemically in the presence of the electrolyte to produce electrons and cations. The electrons are conducted from the anode to a second electrode, i.e. cathode through an electrical circuit connected between the electrodes. Cations pass through the electrolyte to the cathode. Simultaneously, an oxidant, such as oxygen gas or air is introduced to the cathode where the oxidant reacts electrochemically in presence of the electrolyte and catalyst, producing anions and consuming the electrons circulated through the electrical circuit; the cations are consumed at the second electrode. The anions formed at the second electrode or cathode react with the cations to form a reaction product. The anode may alternatively be referred to as a fuel or oxidizing electrode, and the cathode may alternatively be referred to as an oxidant or reducing electrode. The half-cell reactions at the two electrodes are, respectively, as follows:

#H2—2H++2e−

#For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made to the accompanying drawings, which show, by way of example, preferred embodiments of the present invention. The features and advantages of the present invention will become more apparent in light of the following detailed description of preferred embodiments thereof.

#FIG. 1 is a perspective view illustrating a manifold for a fuel cell system according to the present invention;

#FIG. 2 is a perspective view from another angle illustrating the manifold for a fuel cell system according to the present invention;

#Now referring to FIGS. 1 and 2, in which a manifold 10 according to the present invention is shown, the manifold 10 generally comprises one single plate having a plurality of ports and fluid passages provided on the side faces and internally.

#FIG. 3 shows a process flow diagram illustrating the application of the manifold 10 of the present invention in a fuel cell system comprising a fuel cell stack 12. The fuel cell stack 12 typically has three inlets and three outlets, specifically, an anode inlet 103 for fuel gas, typically hydrogen, an anode outlet 104 for the fuel gas, a cathode inlet 101 for oxidant gas, typically oxygen or air, a cathode outlet 102 for oxidant gas, a coolant inlet 105 and a coolant outlet 106. It should be appreciated that the fuel cells in the fuel cell stack can be any type of fuel cell, such as, proton exchange membrane fuel cells, solid oxide fuel cells, direct methanol fuel cells, etc. The type of the fuel cells will not affect the design of the manifold according to the present invention.

#Now the process flow of the fuel cell system will be described in detail with reference being made to FIGS. 3 to 5. Fuel, such as hydrogen, supplied from a fuel source, passes through an anode humidifier 90 (an enthalpy shifting device) upstream of the anode inlet 103 for heating and humidifying the anode inlet stream of the fuel cell stack 12. Then the humidified anode inlet stream flow through an anode inlet water separator 95 in which excess liquid water in the anode inlet stream is separated. Then, the anode inlet stream flows into the fuel cell stack 12 through the anode inlet 103. In known manner, a number of monitoring devices are provided immediately upstream of the anode inlet 103, such temperature sensor and pressure transmitter, etc, for monitoring the condition of the anode inlet stream.