THERMAL-BEHAVIOR OF A SOLID SORPTION GENERATOR

Thermal behaviour of a solid sorption generator. The thermal behaviour of a solid sorption generator of active carbon/alcohol machine, is st udied during hearing and cooling phases with a preheated air flow. A b icylindrical walls generator that contains 0.9 kg of a granular adsorb ent in the presence of residual gas is tested during a cycle of an ave rage duration of 3 hours; the grains of active carbon are rod-shaped o f 0.003 m diameter and 0.008 m average length. the thermal contact con ductance of adsorbent to the wall has an important influence on the ra te of heat transfer between the generator and the external source of h eat. In the absence of alcohol, heat transfer occuring without mass tr ansfer in active carbon is essentially due to the conduction. A numeri cal bidimensional model allows one to justify experimentally the obser ved evolution and proposes thermal contact: conductance between active carbon pellets and the generator wall. A parametric study of the ther mal contact conductance gives 6.5 W.m(-2).K-1 as the best value. A sim ulation of heating and cooling phases with average conductance values between 5 and 30 W.m(-2).K-1 gives model estimated heating and cooling phases duration. (C) Elsevier, Paris.