Thermal analysis of the mixtures of paraffin with aluminum in wide temperature range

Abstract

Thermal analysis of IRT-T reactor fuel elements A Naymushin, Yu Chertkov, I Lebedev et al. Abstract. The mixtures and composites of wax, paraffin and metals are widely used as energy efficient formulations and phase change materials for heat storage. Aluminum is frequently employed in the formulations of many composite explosives or propellants. Metal fuel additives are used in advanced explosive formulations to achieve higher combustion temperatures and longer pressure pulses. In this project, Al-paraffin wax composite materials were prepared and characterized. The thermal stability of the prepared powders was determined by differential scanning calorimeter, simultaneous thermogravimetry analysisdifferential thermal analysis in the temperature range 30-1300˚С at atmospheric pressure. The results of differential scanning calorimeter showed that the thermal performance and structure of the composite materials are stable up to 200˚C.The paraffindecompositionwith an energy release is possible at temperatures over 200˚C and the oxidation of aluminum may be at a temperature above its melting point.It is shown that the maximum total amount of heat generated by the thermal decomposition of the composition was at the mass fraction of aluminum of 16% -18%. Background and the purpose of workThe paraffin as phlegmatizer and the powder of aluminum for improving the energy are widely used in explosives mixtures and rocket propellants [1,2].The purpose of work was study the process of thermal decomposition of the mixture of paraffin and aluminum powder micron dispersion by a simultaneous thermal analysis; the estimation of the activation energy of decomposition of paraffin and the determining the optimal percentage of mixture components for using as energy efficient formulations.Such mixtures are a promising material (phase change materials) in the field of energy saving for thermal batteries. To increase the heat capacity and thermal conductivity of the wax is added powder of aluminum [3,4]. Thus, the heat of fusion of paraffin wax is used for accumulation of thermal energy in thermal batteries [4], and high values of heat of formation and phlegmatizing properties of wax to allow its use in high-energy formulations [5,6].Note that the mixtures of aluminum powder with paraffin are flammable. With the destruction or loss of integrity device possible ignition and combustion of the mixture.Therefore, the study of thermal decomposition of the compositions of paraffin wax and aluminum powder should be performed in a wide range of temperature changes. At low temperatures up to 200°C the information is needed to manage the storage of thermal energy at higher temperatures will be useful for applying