Effect of Mental-Doped on Thermal Properties of K2CO3-Na2CO3 eutectic salt/magnesium oxide Composites for Thermal Energy Storage

Abstract

Abstract In this work, Na2CO3-K2CO3/MgO composites with MgO serving as supporting material and Na2CO3-K2CO3 eutectic salt acting as thermal absorbing materials were prepared by the form-stable technique. Besides, the possible effects of Cu, Fe and Al on the thermal properties of the composite were investigated. The thermal properties including phase composition, latent heat and thermal conductivity, etc. were measured using X-ray diffraction, differential scanning calorimetry, thermal constant analyzer and thermogravimetric analysis, etc. The X-ray diffraction results show that Na2CO3-K2CO3 and MgO have good chemical compatibility. The differential scanning calorimetry results show that the melting point of the Na2CO3-K2CO3/MgO composites is 707.5°C and its enthalpy of fusion is 67.98J/g. The thermal constants analyzer results indicate that the addition of metal powder can improve the thermal conductivity of the sample, but the increase rate is not obvious because of its oxidation in the air, some even reduce the thermal conductivity.