Resonance Response of Reverse Flow Reactors: A Numerical Simulation

The effect of periodic time-varying inlet parameters on reverse flow reactor behavior is simulated using a one-dimensional heterogeneous model with methane as the model reactant. When the flow-reversal cycle is an odd multiple of the inlet concentration variation cycle, a resonance response occurs. Such reactor behavior will occur with various values of superficial inlet velocity, mean inlet methane concentration, flow-reversal time and inert-to-catalyst ratios during this simulation work. A synchronization of the two cycles will cause a sharp increase in the variation of maximum temperature, which may impair reactor stability. Simulation results reveal that the resonance response is attributed to the breakdown of temporal and spatial symmetry in the temperature field of reactor. When a resonance response occurs, adjusting the flow-reversal time is a feasible method to maintain autothermal operation of the reactor. Different from commonly used control strategies both increasing and decreasing flow-reversal time can be used to avoid reactor extinction, and so does avoiding thermal runaway. Simulation work of introducing periodic variation of inlet gas velocity is performed, and a similar resonance response behavior is observed.