Thermal conductivity determination in the case of a porous medium made up of carbon fibres
Tarik Dellero, Rahal Boussehain, Christian Jallut, Philippe Touzain, Michel Feidt
The performance of a chemical heat pump, based on a reversible gas – solid reaction, is enhanced by the addition of carbon fibres, which increase the thermal conduction. The flash method was used to measure both longitudinal and perpendicular thermal conductivities of the reagent bed containing carbon fibres. The perpendicular model confirmed the flash method measurement but the parallel model did not confirm the experimental value. A second method, based on modelling of the reactor, was used to determine the longitudinal thermal conductivity. This method confirmed the result given by the parallel model. In the flash method, the longitudinal thermal conductivity is sensitive to the contact resistance, and for this reason the measurement could not be confirmed by means of the parallel model.