An enhanced adsorption cycle operated by periodic reversal forced convection

A different cycle configuration is suggested in this work. Interesting impr ovement in performances is envisaged by applying the fixed bed adsorbers wi th the forced unsteady-state operation of periodic flow reversal to convect ive thermal wave cycle, which results in the so-called Periodic Reversal Fo rced Convective cycle. To describe process behavior for this kind of cycle with seven possible operating modes of flow reversal, a two-phase, one-dime nsional model for the zeolite 13X-water pair is developed. Some important p henomena, such as the heat pipe effect, internal and external thermal regen eration etc., are discussed. The results of numerical simulations show that among all possible operating modes of flow reversal, only the mode of CCAA (switching the flow directions each phase duration) could improve the glob al performances of non-reversed flow operation, but others could not. Under the current conditions of cycle, the proposed CCAA cycle with heat exchang er regenerator could offer significant improvements in coefficient of perfo rmance (COP) over both the conventional cycle without flow reversal operati on and existing convective thermal wave cycle with inert packed bed regener ator. The results of calculation also show that more than 1.7 of COPh, 0.9 of COPc and 125 W/kg adsorbent of specific cooling power (SCP) within this system could be possible. Analysis gives satisfactory explanation of these results. (C) 2000 Elsevier Science Ltd. All rights reserved.