Thermal Conductivity of Vacuum Insulation Materials for Thermal Energy Stores in Solar Thermal Systems. (June 2016)

• Record Type: Journal Article
• Authors: Lang, Stephan; Gerschitzka, Markus; Bauer, Dan; Drück, Harald
• Is Part Of: Energy procedia. Volume 91(2016)
• Page Start: 172
• Page End: 181
• Publication Date: 2016-06
• Subjects: vacuum insulation -- high efficient thermal insulation -- thermal energy store -- heat storage; Power resources -- Congresses; Power resources -- Periodicals; Power resources; Conference proceedings; Periodicals; 333.7905
• DOI: 10.1016/j.egypro.2016.06.196
• Languages: English
• ISSNs: 1876-6102

Abstract

Abstract: The effective thermal conductivity of fine-grained and coarse-grained expanded perlites, fumed silica and a mixture of coarse-grained expanded perlite and fumed silica at different vacuum pressures is experimentally investigated in this paper. For the investigations two different test rigs – a guarded cylinder apparatus and a guarded hot plate apparatus – were used. The lowest effective thermal conductivities were performed with fumed silica at ambient pressure, with the mixture at pressures between 1 and 10 mbar and with fine-grained expanded perlite at 0.1 mbar and lower. Mixtures of fumed silica and expanded perlites appear to be a great chance to achieve low effective thermal conductivities and lower prices compared to pure fumed silica at vacuum pressures that can be easily achieved for large-volume thermal energy stores.