Hybrid modeling and dynamics of a controlled reverse flow reactor

A hybrid system approach is adopted to study the dynamic behavior of a controlled reverse flow reactor, where the occurrence of flow inversions is caused by a feedback control strategy. With this approach it is analyzed, theoretically and numerically a typical behavior of hybrid systems: Zeno phenomena. Hybrid system theory is also adopted to define a suitable Poincare map that is a composition of two switching maps. Based on the Poincare map an efficient methodology is developed for the continuation of limit cycles, and detection of local bifurcations as the set-point value, and inlet temperature are varied. This analysis shows that Zeno states can be coexisting with symmetric and asymmetric periodic regimes in a wide range of the parameters. The analysis of the nonlinear behavior and Zeno phenomena gives an insight on the limits of some model assumptions, and how these assumptions should be removed to avoid the unphysical response of Zeno executions. Considering a time delay due to the valves in the reactor, the unphysical Zeno state is removed, while Zeno like oscillations are shown to be still persistent. (c) 2007 American Institute of Chemical Engineers.