Mechanical and thermal behaviors investigation of hollow concrete blocks incorporating a phase change material

Mohammed Azouggagh2^{2}, Mustapha Mahdaoui1,^{1,\star}
^{\star} :
1^{1} ETTE, FSTT, Abdelmalek Essaadi University -Tetouan,
2^{2} Faculty of Sciences de Meknes, Moulay Ismail University
Mots clés : Hollow Concrete Bloc; Phase Change Materials; Mechanical Behavior; Thermal Behavior;
Résumé :

The thermal and mechanical behavior of HCB impregnated by a PCM were evaluated is this study. This building component widely used in the construction of buildings has a bad thermal behavior in hot areas. Consequently, the present work aims, first, to improve its storage capacity and its insulation resistance, thanks to its filling with a PCM, next, to examine the PCM effects on the thermal and mechanical behaviors of HCBs. Two numerical models were validated and used to study the PCM effects on the mechanical and thermal behaviors of HCBs. On the mechanical side, the CDP model was implemented in the FEM software ABAQUS/Standard to describe the compression behavior. On the thermal side, the Ansys-Fluent software that is based on the finite volume method, was adopted to study the thermal behavior of HCB - PCM. The following conclusions can be drawn:

-In the three cases (HCBs without PCM, PCM in one hole, and PCM in two holes), the numerical predictions of the variation of the normal stress according to the normal strain confirmed that PCM integration has insignificant effect on the behavior of HCB.

-The thermal behavior of HCB-PCM, studied by fluxmeter method, highlighted that the amount of PCM has a significant impact on the melting process. It is apparent that raising the volume portion of PCM in HCB lengthens the transition change procedure. In addition, from heat flux diagram depicts PCM’s great capacity to absorb and release heat while reaching the desired time lag.

-The 3D thermal simulation showed that HCB’s left vertical face was exposed to a sinusoidal temperature (Tout), which reflects daily temperature variations in the summer environment of hot regions. A constant summer comfort temperature T_in$=299K is placed on the HCB’s right vertical side. Overall heat transfer coefficients on both vertical sides are considered.

-A parametric investigation was performed to investigate the impact of PCM thermophysical properties on the heat transfer of the HCB with PCM to minimize the inside surface temperature and maintain it in the thermal recommended range. The obtained findings revealed that the PCM characteristics had an important influence on decrement factor and time lag indicators, and therefore on the HCB behavior.

Work In Progress