Thermal Conductivity Measurement of Salt Hydrates as Porous Material using Calorimetric (DSC) Method

The effective thermal conductivity of calcium chloride was measured and its value was increased by two and around three times when impregnating Expanded Vermiculite and Silica Gel with calcium chloride with standard uncertainty ±0.004%. The porous matrix was fabricated by taking Silica Gel / Expanded Vermiculite that had been soaked in a bath of calcium chloride solution with a salt concentration of 40 wt% and then heat-treated at 200 °C. The properties of the porous materials were measured using the heat flux DSC for particles size of 0 – 3 mm in the temperature range from 100 °C to 200 °C. These are small samples having a diameter less than 5.0 mm, a height less than 4.25 mm and a low thermal conductivity. In the studied properties, we focus on thermal conductivity, the obtained values were presented as function of the porosity range values. The performance of the salt-composite widely demonstrated nowadays, will be used in a heat storage system for households application. However, some problems related to the heat loss and open system have not allowed to observe the accurate thermal resistance as expected. Some avenues are explored prior to a new and more appropriate design and eventually a new operating mode.