Abstract: Energy conservation has great significance in today's society.In this paper, Na2SO4 · 10H2O was selected as a phase change material ( PCM ) which was encapsulated into different carriers , such as SiO2 aerogels, X-type molecular sieves, expanded perlite, activated carbon and diatomite by using direct impregnation method for preventing the leakage and guaranteeing the long-term thermal stability during the phase transition .Test results of SEM , DSC and XRD show that the percentage of PCM in the different adsorbents is 80.0;,82.2;,76.9;,89.2; and 60.6; respectively after saturation adsorption . Compared with other carriers the expanded perlite ( EP ) is the most cost-effective carrier material in terms of thermal properties , mechanical properties and cost .The Na2SO4 · 10H2O/EP composite phase change material was further detected for the thermal cycle experiment .After 100 cycles, its calorific value loss is less than 15;, and the undercooling is within 10℃, indicating that the Na2SO4· 10H2O/EP has a good thermal stability .

Key words: Energy conservation has great significance in today's society.In this paper, Na2SO4 · 10H2O was selected as a phase change material ( PCM ) which was encapsulated into different carriers , such as SiO2 aerogels, X-type molecular sieves, expanded perlite, activated carbon and diatomite by using direct impregnation method for preventing the leakage and guaranteeing the long-term thermal stability during the phase transition .Test results of SEM , DSC and XRD show that the percentage of PCM in the different adsorbents is 80.0;,82.2;,76.9;,89.2; and 60.6; respectively after saturation adsorption . Compared with other carriers the expanded perlite ( EP ) is the most cost-effective carrier material in terms of thermal properties , mechanical properties and cost .The Na2SO4 · 10H2O/EP composite phase change material was further detected for the thermal cycle experiment .After 100 cycles, its calorific value loss is less than 15;, and the undercooling is within 10℃, indicating that the Na2SO4· 10H2O/EP has a good thermal stability .