Research on Advanced Energy Storage Devices and Systems for Passive Solar Residential Applications for Mass Market Housing. Final Report

摘要

Five tasks were addressed in this project: (1) Application Analysis, (2) Materials, (3) Heat Transfer Considerations, (4) Containers and Encapsulation and (5) Dissemination of Information. The NAHB/RF application analysis studies relate to the builder's perceptions of phase change materials (PCMs) and the constraints to widescale adoption in the home building industry. The purpose of this analysis was to determine the characteristics that specific thermal storage systems must have to be acceptable to the American home building community. Salt hydrates appear to be able to meet the objectives of low cost thermal energy storage. However, heretofore not enough attention has been given to the thermochemistry of salt hydrates. In principle, congruent salt hydrates are preferred, although CaCl/sub 2.6/H sub 2 O, a congruent salt hydrate, exhibits significant volume change upon changing phase. Because the testing undertaken in this program consistently revealed containment failure, we believe that one must address the mechanisms of failure and try to determine whether these result from processes specific to the salt hydrates or whether the failures represent only an inconsistency of plastics manufacturing. The problem is, of course, further exacerbated by solar illumination and any degradation resulting from this exposure. Future work must seek to identify the reasons for container failure as well as the design options to prevent it, while maximizing heat transfer both into and out of the container. (ERA citation 10:033544)