Optimization of thermal performance in thermocline tank thermal energy storage system with the multilayered PCM(s) for CSP tower plants

K. E. Elfeky, Xinyi Li, N. Ahmed, Lin Lu, Qiuwang Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

21 Citations (Scopus)

Abstract

The current paper presents two parametric studies (inverse Stefan number and dimensionless temperature difference) to optimize the values of latent heat and melting temperature of multilayered phase change materials (MLPCM(s)) in thermocline tank for concentrating solar power (CSP) plants. Spherical capsules filled with PCM(s) of different thermo-physical properties are used to fill the bed region, and the molten salt is used as heat transfer fluid (HTF). The numerical model that has been developed uses the Dispersion-Concentric (D-C) equations. By using MATLAB, the governing equations are solved and validated against the experimental results. The results show that in the optimal configuration of the case (B), the values of InvSte number and dimensionless temperature (θm) are equal to 1.2 and 0.8 for the top PCM layer, respectively; 0.75 and 0.55 for the middle PCM layer, respectively; and 0.65 and 0.3 for the bottom PCM layer, respectively. Moreover, it is also found that to obtain the best design and distribution of temperature for a thermocline tank consisting of three layers of PCM, the top PCM layer should melts by ΔT = 55.4 °C below the HTF charging inlet temperature, the PCM layer at the bottom should solidifies by ΔT = 83.1 °C above HTF discharging inlet temperature.

Original languageEnglish
Pages (from-to)175-190
Number of pages16
JournalApplied Energy
Volume243
DOIs
Publication statusPublished - 1 Jun 2019

Keywords

  • Concentrating solar power plants
  • Encapsulated phase change material
  • Multilayered phase change materials
  • Thermal energy storage
  • Thermocline tank

ASJC Scopus subject areas

  • Building and Construction
  • Energy(all)
  • Mechanical Engineering
  • Management, Monitoring, Policy and Law

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