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Study of energy accumulation during phase change of paraffin wax
Lapčíková, Tereza ; Krouská, Jitka (referee) ; Zmeškal, Oldřich (advisor)
This thesis deals with the study of the process of energy storage during phase transformation, the so-called latent heat for commercial materials of the Rubitherm® RT line (Rubitherm Technologies GmbH) with applications in the construction industry. The thermophysical properties of Rubitherm® RT35HC, RT28HC and RT18HC materials differing in phase transformation temperature were investigated using the transient method. For the Rubitherm® RT35HC material a value of the thermal conductivity coefficient in the solid phase of 0.21 W/m/K and in the liquid phase of 0.23 W/m/K was determined. The specific heat capacity value in the solid phase was determined to be 1980 J/kg/K and in the liquid phase 1995 J/kg/K. For Rubitherm® RT28HC, the value of the thermal conductivity coefficient in the solid phase was determined to be 0,23 W/m/K and the value of the specific heat capacity in the solid phase was determined to be 1997 J/kg/K. For the Rubitherm® RT18HC material, a liquid phase thermal conductivity coefficient of 0,27 W/m/K and a liquid phase specific heat capacity of 2010 J/kg/K were determined. Using differential scanning calorimetry (DSC), the melting temperature of the Rubitherm® RT28HC sample was determined at 27.43 °C and solidification at 23.51 °C, while for the Rubitherm® RT35HC sample melting occurred at 36.51 °C and solidification at 31.86 °C and 32.28 °C. In the experimental part of this work, modifications were made to the measuring apparatus used in such a way that it could be used for the study of materials that change their state of matter during the experiment.
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