Thermodynamic analyses and assessments of various thermal energy storage systems for buildings

Abstract

In this study energetic exergetic environmental and sustainability analyses and their assessments are carried out for latent thermochemical and sensible thermal energy storage (TES) systems for phase change material (PCM) supported building applications under varying environment (surrounding) temperatures. The present system consists of a floor heating system System-I System-II and System-III. The floor heating system stays at the building floor supported with a floor heating unit and pump. The System-I includes a latent TES system and a fan. The latent TES system is comprised of a PCM supported building envelope in which from outside to inside, glass transparent insulation material PCM air channel and insulation material are placed respectively. Furthermore System-II mainly has a solar-thermochemical TES while there are an aquifer TES and a heat pump in System-III. Among the TESs the hot and cold wells of the aquifer TES have maximum exergetic efficiency values of 88.782% and 69.607% at 8°C dead state temperature respectively. According to the energy efficiency aspects of TESs the discharging processes of the latent TES and the hot well of the aquifer TES possess the minimum and maximum values of 5.782% and 94.118% at 8°C dead state temperature respectively. Also the fan used with the latent TES is the most environmentally-benign system component among the devices. Furthermore the most sustainable TES is found for the aquifer TES while the worst sustainable system is the latent TES. © 2012 Elsevier Ltd. All rights reserved. © 2012 Elsevier B.V. All rights reserved.