Experimentally based testing of the enthalpy-porosity method for the numerical simulation of phase change of paraffin-type PCMs

Martínez, Arnold ; Carmona, Mauricio ; Cortés, Cristóbal (Universidad de Zaragoza) ; Arauzo, Inmaculada (Universidad de Zaragoza)

Resumen: The enthalpy-porosity method is generally applied as an economical resort for the numerical simulation of phase change materials (PCMs). However, having been developed strictly for metals, its suitability for the task is unclear, nor is the rationale for assigning its internal parameters, e.g., latent enthalpy and the constant of the momentum source term representing the “mushy” region. We first experimentally and exhaustively characterize a paraffin-type PCM, including differential scanning calorimetry (DSC) at several heating rates, T-history, and fusion visualization. Then, we develop a numerical model and systematically run simulations under different internal parameters and thermophysical properties of the PCM. Simulation results exhibit significant disagreement with experiments that cannot be reduced by any strategy for combining different material properties and model parameters. Among other effects, the constant of the momentum source term, which has to be assigned somewhat arbitrarily, has more relevance in the accuracy than any set of properties obtained by DSC and other experimental techniques. Thus, a rather negative, although interesting, conclusion is suggested: the enthalpy-porosity method may fail to model the phase change of paraffin-type PCMs. This is, of course, of paramount importance for the studies of their utilization in practical systems since it puts a fundamental point of uncertainty in any numerical study or lumped-type model derived thereof. The paper concludes with a tentative discussion of the possible causes of this failure and perspectives for developing more proper models.

Idioma: Inglés

DOI: 10.1016/j.est.2023.107876

Año: 2023

Publicado en: Journal of Energy Storage 69 (2023), 107876 [14 pp.]
ISSN: 2352-152X

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Máquinas y Motores Térmi. (Dpto. Ingeniería Mecánica)