Dynamic modelling of an activated carbon–methanol adsorption refrigeration tube with considerations of interfacial convection and transient pressure process

In the present study, a dynamic model of the adsorption refrigeration cycle was established with the consideration of interfacial convective heat transfer within adsorbent particles. In the model, a concept and mathematical definition of a transient pressure process at the beginning of the traditionally considered isobaric adsorption process are introduced. The model was solved numerically and experimentally verified in terms of the adsorbent/adsorbate temperature development, system pressure variation, and dynamic adsorption/desorption amount. A temperature jump at the beginning of the adsorption process was experimentally identified and was successfully predicted in the numerical simulation with the introduction of a transient pressure process. Numerical results simulated with the newly introduced transient pressure process and the traditional constant pressure process were compared. The comparison shows that the introduced transient pressure process can significantly improve the accuracy of the presented model. In addition, a notable adsorbate migration phenomenon was discussed according to the abnormal temperature development in the processes of isosteric heating and cooling. The present model can be used for a valve-controlled and long cycle-time based ART and other systems with similar operating procedures.

► A model considering interfacial convection and transient pressure was proposed.
► An empirical formula for the transient pressure process was established.
► The model is able to predict the adsorbent temperature jump phenomenon.
► The model can reveal the mechanism of the adsorbent temperature development.