Polytechnic University of Valencia Congress, 21st International Drying Symposium

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On the importance of heat and mass transfer coupling during characterization of hygroscopic insulation materials
Patrick Perre, Arnaud Challansonnex

Last modified: 03-01-2019

Abstract


The present work is focused on mass transfer characterization of hygroscopic materials used for insulation, such as Low Density Fibreboards. Due to their particular morphology, these panels present a very high mass diffusivity in the connected gaseous phase and a very low thermal conductivity. This combination of properties exacerbates the coupling between heat and mass transfer in transient state.

Based on experimental data obtained with an original set-up and relevant simulations performed using a comprehensive physical formulation, a throughout vision of this question is proposed in the present study. In particular, we emphasize on:

- The impressive change in core temperature in terms of magnitude and duration,

- The great impact of the internal temperature gradient, which slows down mass diffusion,

- The dramatic error on mass diffusivity value if the coupling is ignored.

Keywords: experiment; identification; modelling; RH at back-face; transient state


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