Development of New Heat Supply Unit Using Latent Heat: Dynamic Characteristics of Heat Storage Unit by a Use of Plate Fin Type Heat Exchanger

A high efficient co-generation system named “Neighboring Communities Co-generation System” is proposed to a multiple dwelling house. The key technology of this system is to connect home and home with one loop of heat transfer line of one-inch diameter, and to level the heat demand by a heat storage unit in each house. This system requires a compact heat storage unit of quick response. In this study, a plate fin type brazing heat exchanger was built and tested as the heat storage unit. Sodium acetate trihydrate with a melting point of about 58 °C and a paraffin wax with a higher value of 74.8 °C were used as the phase change material (PCM). As a result, it was shown that the heat transfer in the heat storage unit was dominated by thermal conductivity in PCM. The paraffin wax showed higher responsibility and higher heat output due to its higher melting point and quite lower super cooling in solidification.