_The Investigation of Mechanical and Thermal Properties of Sintered Bauxite and Sand Particles as Heat Transfer and Storage Media


Uykun Z., TARI İ., BAKER D. K.

27th International Conference on Concentrating Solar Power and Chemical Energy Systems: Solar Power and Chemical Energy Systems, SolarPACES 2021, Virtual, Online, 27 Eylül - 01 Ekim 2021, cilt.2815 identifier

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Cilt numarası: 2815
  • Doi Numarası: 10.1063/5.0149000
  • Basıldığı Şehir: Virtual, Online
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

The concept of using solid particles as heat transfer and storage medium has drawn interest in recent years with the advantages over the existing technologies. However, the behavior of particles in the commercial systems should be predicted beforehand, which can be modeled with DEM accurately. This study focuses on investigating mechanical interaction and thermal properties of sintered bauxite and sand particles that are input to DEM models of heat transfer and storage systems. Direct measurements and calibration approaches were utilized together to obtain the mechanical interaction properties of particles. A resultant mechanical interaction parameter set including rolling and sliding friction coefficients and restitution coefficients between particles and particles and metal boundary for sand and sintered bauxite particles is presented. It is found that rolling and sliding friction coefficients between particles and wall does not show apparent difference depending on particle type. However, the rolling friction coefficient between sand particles is higher than sand sintered bauxite particles which can be explained by the shape effect. The interparticle sliding friction coefficient of sand particles is lower than sintered bauxite particles, which proves that the sliding friction coefficient is not related to the shape effect but the material itself. Sintered bauxite particles have higher interparticle and particle-wall restitution coefficients than sand particles, which is coherent with previous experimental results and observations. Effects of thermal cycling and high temperatures on mechanical interaction properties were examined. Hot Disk measurement equipment was used to validate the available data of temperature-dependent thermal properties of examined particles. Measurement results obtained in this study show a maximum 10.45% deviation from the available results in the literature. Sensor bias of the measurement equipment, which occurs at high temperatures, was corrected.