Thermal and mechanical characteristics of a multi-functional Thermal Energy Storage structure

Thermal Energy Storage (TES) sandwich-structures that combine the heat storage function with structural functionality are described. The structure consists of a Thermal Interface (TI) connected to a hollow plate lamination. Each laminate is a hollow aluminum plate having a series of mm-scale channels or compartments that are filled with Phase Change Material (PCM). Heat storage is via the latent heat of the PCM. A generalized thermal response model that is applicable to a wide range of channel geometrical configurations is described. The model couples the thermal response of the TI to that of the aluminum/PCM lamination. It gives rise to closed-form solutions for the spatial temperature distribution within the TES-volume. The temporal response of the system is easily obtained via numerical solution of two ordinary differential equations. Thermal analysis delineates geometrical configurations that have good thermal response characteristics. The mechanical properties of the laminated structure were determined experimentally. Four-point bending experiments were conducted using specimens made with three layers of hollow plates laminated using a structural adhesive. An energy method was developed to model the deformation and strength of the laminated structure. The energy method can correctly simulate the experimental results. Experiments and modeling indicate that these laminated structures have an excellent performance-to-weight ratio.