Heat Storage Material with Crystal Transformation for Micro- and Nano-satellites
The thermal analysis of a micro cubic satellite pointing to the Earth on a sun- synchronous and circular orbit has been carried out using one-nodal analysis. The altitude of the orbit is 500 km. The local time of descending node of the orbit is 11 AM. The combination of the solar absorptivity and the infrared emissivity on the surface of the satellite under which the temperature of the satellite is kept within the allowable temperature range, from 0 to 40 degree Celsius, has been clarified. As the heat capacity is getting larger, the number of the combinations of the solar absorptivity and the infrared emissivity increases. In order to increase the heat capacity of micro- and nano-satellites, the development of a heat storage material has been performed. It is desirable that the heat storage materials for micro- and nano-satellites have the characteristic of not phase-change but crystal transformation at heat storage because a container for heat storage material is not required. Trans-1,4-polybutadiene transforms crystal structure at the temperature of heat storage. Trans-1,4-polybutadiene is produced and the heat storage performance is measured. The produced trans-1,4-polybutadiene has the amount of heat storage of about 80 J/g at the heat storage temperature of 74 °C This amount corresponds to about 70% amount of heat storage of a literature data (112 kJ/kg). The density of the produced trans-1,4- polybutadiene is 706 kg/m3.