An analytical solution for a cyclic regenerator in the warm-up period in presence of an axially dispersive wave

Regenerative heat exchangers are important components of energy intensive s ectors such as chemical process, power, metallurgical and cryogenic industr y. The challenge of simulating regenerators accurately is considerable in v iew of the transient cyclic process taking place in it. The simulation of w arm-up period is even more challenging due to the change in temperature pro files after each cycle. In the present work a modern technique based on the "axial dispersion model" has been utilized to simulate the regenerative he at exchanger both in the warm-up and pseudo-steady state operation. The adv antage of this model is that it takes all the flow maldistribution and back mixing effects into consideration instead of idealizing the flow to be so c alled "plug flow". In contrast to previous studies with dispersion, in the present study the dispersion is considered to propagate with a finite propa gation velocity following a hyperbolic law which is physically more consist ent. The effect of different parameters on the cyclic response has been bro ught out and the results have been verified by comparing results of a rotar y regenerator available in literature. The technique utilized in the presen t study can act as a tool for modelling regenerators where non-uniformity i n flow distribution is significant. (C) 2001 Editions scientifiques et medi cales Elsevier SAS.