A translucent honeycomb solar collector and thermal storage module for building façades

Abstract

An innovative new translucent honeycomb solar collector and thermal energy storage module has been designed. The honeycomb module contains two different kinds of channels, namely empty ones and those that are filled with a Phase Change Material (PCM). The latter are sealed at the front and back side and, therefore, form chambers. Solar radiation enters the empty channels and is transmitted forward into them. The absorbed energy fraction at the side walls of these empty chambers leads to a melting of the PCM in their neighboring filled chambers, where then thermal energy is stored as latent heat. A heat transfer fluid, usually air, crosses the empty channels by forced convection and additionally charges or discharges the storage modules. Such elements are ideal to equip “intelligent” building façades in passive houses or then to form thermal storage elements in decentralized air-conditioning systems by integration into the façade of e.g. an office building. This first article presents the innovative solar system and gives new results on simplified two-dimensional temporal-spatial physical modeling, numerical simulation of charging and discharging modes and of a combined mode for a typical practice case. The content of a second planned article on system optimization and full system performance, including the description of thermal behavior of system/building combinations is roughly sketched in the section ‘Conclusions and Outlook’.