Abstract: First and Second Law analyses were conducted to evaluate the performance of a closed latent
heat thermal energy storage (LHTES) system employing calciumchloride hexahydrate (CaCl2-
6H2O).The First and the Second Laws of thermodynamics were applied to the system from
viewpoint of energy and exergy analyses,respectively. The energy storage tank in the system
is neither fully mixed nor fully stratified. It may be considered as semithermal
stratified. Experiments that include both charging and discharging periods were performed
on sunny winter days in 1996. The energy and exergy variations and the overallenergy and
exergy efficiencies of the closed LHTES system were calculated for the complete charging
and discharging cycle of the selected fifteen clear-sky winter days. Mean energy and exergy
efficiencies were found to be 55.20% and 34.83%, respectively.

Key words: thermodynamics, domestic heating, energy, exergy, latent heat, phase change material

摘要： First and Second Law analyses were conducted to evaluate the performance of a closed latent
heat thermal energy storage (LHTES) system employing calciumchloride hexahydrate (CaCl2-
6H2O).The First and the Second Laws of thermodynamics were applied to the system from
viewpoint of energy and exergy analyses,respectively. The energy storage tank in the system
is neither fully mixed nor fully stratified. It may be considered as semithermal
stratified. Experiments that include both charging and discharging periods were performed
on sunny winter days in 1996. The energy and exergy variations and the overallenergy and
exergy efficiencies of the closed LHTES system were calculated for the complete charging
and discharging cycle of the selected fifteen clear-sky winter days. Mean energy and exergy
efficiencies were found to be 55.20% and 34.83%, respectively.

关键词: 热量储存系统;储存密度;等温条件;物相变化;温度;含水率