Static and dynamic modeling of a diesel fuel processing unit for polymer electrolyte fuel cell supply

This article introduces the energetic macroscopic representation (EMR) as approach for the dynamic modeling of a diesel fuel processing unit. The EMR is the first step toward model-based control structure development. The autothermal fuel processing system containing: heat exchanger, reformer, desulfurization, water gas shift, preferential oxidation and condensation is divided into a multitude simple subblocks. Each subblock describes an elementary step of the fuel conversion, several of these blocks may occur in a single module. Calculations are carried out using two basic principles: mass and energy balances. For model-based control development, it is imperative that the model represents dynamic behavior, therefore temperature and pressure dynamics are taken into account in the model. It is shown that the model is capable to predict the stationary behavior of the entire fuel processing unit correctly by comparison with given data. Predictions regarding reformer heat up, temperature and pressure dynamics are also provided.