A dynamic scalable segmented model of PEM fuel cell systems with two-phase water flow

A lumped parameter dynamic scalable segmented model of the proton exchange membrane fuel cell (PEMFC) system is developed to predict the current density, temperature, pressure, and two-phase water flow distributions. Specifically, a single cell is divided into several interconnected segments that are connected according to flow field patterns with physical ports balancing the across and through variables automatically. Every segment is viewed as a lumped parameter system with multi-physics coupled together. Moreover, a new liquidation algorithm is proposed by introducing a stiffness term into the vapor pressure dynamics to simulate the two-phase water flow. The main feature of the proposed model is the flexibility in the sense that variable numbers of segments and reconfigurations for different flow field patterns can readily be incorporated due to physical modeling. Simulation results show that the model can simulate both the steady state and dynamic operations well with two-phase water flow distribution. The scalability (both scale up and scale down) of the proposed model is demonstrated through the simulations of the 3 × 3 and 6 × 6 segmented models. The comparison of different flow field patterns shows that the flow field pattern has decisive influences on the current density, two-phase water flow, and pressure distributions.