DISTRIBUTION OF GAS-FLOW IN INTERNALLY MANIFOLDED SOLID OXIDE FUEL-CELL STACKS

In internally manifolded fuel-cell stacks, there is a non-uniform gas flow distribution along the height of the system. To gain an insight i nto this distribution an analytical model has been developed. In the m odel, the stack is viewed as a network of hydraulic resistances. Some of these resistances are constant, while some depend upon the gas velo city and can be determined from the literature. The model consists of equations for the network with counter-current flow in the manifold ch annels. Only the most important resistances are included, i.e., the re sistances due to splitting and combining the flows in the manifold cha nnels, and the resistance in the gas channels of the active cell area. The ratio between the average flow and the flow in the upper cell can be solved from the model. In this manner, a very useful tool for sepa rator-plate design is obtained.