Experimental investigation of a thermal energy storage unit integrated with thermoelectric generators under solar radiation


ACIR A., Kaan Çinici O.

Solar Energy, vol.265, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 265
  • Publication Date: 2023
  • Doi Number: 10.1016/j.solener.2023.112028
  • Journal Name: Solar Energy
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Agricultural & Environmental Science Database, Applied Science & Technology Source, Communication Abstracts, Compendex, Environment Index, Geobase, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: Energy conversion efficiencies, Phase change material (PCM), Solar thermal energy storage (STES), Solar thermoelectric generator (STEG), Thermal energy storage efficiencies
  • Gazi University Affiliated: Yes

Abstract

In this present study, a phase change material (PCM) based thermal energy storage unit (TESU) integrated with thermoelectric generators (TEGs) was experimentally investigated under artificial solar radiation. Within the scope of the experiments, a TESU with the dimensions of 15x15x5 cm was designed by assembling nine TEGs connected in series on the TESU. In the design, two types of paraffin based PCM with different thermophysical properties values as PCM in TESU and two models of TEGs with different power were used. Four different TEG/TESU designs with different parameters were made, namely TEC1-12706/P1, TEC1-12706/P2, TEC1-12710/P1, and TEC1-127010/P2. Charge-discharge processes of each design were investigated under radiation intensities of 800, 1000, and 1200 W/m2. According to the results of the experiments, it was observed that as the power of the TEG used increased, the melting time of the paraffin was shortened, and the energy conversion efficiency (ECE) and the thermal energy storage efficiency (TESE) increased. It was determined that the maximum power obtained from the designs with TESU was approximately 11 % higher than that without TESU. The result showed that more efficient TEG systems would be obtained by making the temperature of the cold surface of TEGs more stable with PCM. In addition, it was determined that the melting time decreased and the TESE and ECE increased with the increment of the radiation intensity. The shortest melting time of 135 min, the highest TESE of 80.72 % and the highest ECE of 2.32 % were obtained from the TEC1-12710/P2 design under 1200 W/m2 radiation. The longest melting time of 240 min, the lowest TESE of 64.62 % and the lowest ECE of 2.04 % were obtained from the TEC1-12706/P1 design under 800 W/m2 radiation.