Abstract
The need for thermal energy storage technologies is critical because they can play a key role in enabling renewable heat systems to be adopted for industrial applications and reduce consumption of fossil fuels. Earlier studies have indicated that, natural rocks have potential for cost effective heat storage applications and in this data set, thermophysical properties of natural rock samples including, (basalt, dolerite, gabbro, granite, rhyolite, gneiss and quartzite) from Zimbabwe, were determined. Both experimental methods and numerical calculations were applied to generate this data. Specific heat capacity, thermal stability and density were obtained using experimental measurements while thermal diffusivity was determined through calculations using data from experiments and literature. Values of specific heat capacity for all rock samples, as obtained from the Differential scanning calorimetry, range from 767 J/kgK and 861 J/kgK to 942 J/kgK and 1090 J/kgK, at room temperature and at 250 ℃ respectively. Thermogravimetric analysis for thermal stability measurements of rocks produced a data set which indicates that, the samples have a maximum weight loss of less than 5 % when heated up to temperatures of 700 ℃. Experimental measurements for wet density of all rock samples have shown that the values vary between 2500 kg/m(3) and 3001 kg/m(3). Deduced values of thermal diffusivity vary from 2.14 mm(2)/s and 0.79 mm(2)/s at room temperature to 1.08 mm(2)/s and 0.54 mm(2)/s at 250 ℃ for all the samples used. The generated data set can be used to guide the choice of suitable natural stones to be considered for developing sensible thermal energy storage systems. In addition, this data can be used to analyse variations in thermal characteristics of different types of natural rocks.