Utilization of Fly Ash Nanofluids in Two-phase Closed Thermosyphon for Enhancing Heat Transfer

SÖZEN A., Menlik T., Guru M., Irmak A. F., Kilic F., Aktas M.

EXPERIMENTAL HEAT TRANSFER, vol.29, no.3, pp.337-354, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 29 Issue: 3
  • Publication Date: 2016
  • Doi Number: 10.1080/08916152.2014.976724
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.337-354
  • Keywords: nanofluid, two-phase closed thermosyphon, fly ash, THERMAL PERFORMANCE, CONDUCTIVITY, PIPES, ENHANCEMENT
  • Gazi University Affiliated: Yes


This study investigates how fly ash nanofluids affect the thermal performance of a two-phase closed thermosyphon at various states of operation. The utilization of nanofluids obtained from X2O3-type oxides, such as Al2O3, Fe2O3, or CuO, on the improvement of two-phase closed thermosyphon performance was reported in a number of studies in the literature. The present study experimentally demonstrated the effect of using a nanofluid obtained from fly ash comprised of various types of metal oxides in varying ratios on improving the performance of a two-phase closed thermosyphon. The fly ash was obtained from the flue gas that was captured in the cyclones of the Yatagan thermal power plant (Turkey). Triton X-100 (Dow Chemical Company) dispersant was used in the study to produce the 0.2% (wt) fly ash/water nanofluid via direct synthesis. A straight copper tube with an inner diameter of 13mm, outer diameter of 15mm, and length of 1m was used as the two-phase closed thermosyphon. The nanofluid filled 33.3% (44.2ml) of the volume ofthe two-phase closed thermosyphon. Three heating power levels (200, 300, and 400W) were used in the experiments with three different flow rates of cooling water (5, 7.5, and 10g/s) used in the condenser for cooling the system. A increase of 26.39% was achieved in the efficiency of the two-phase closed thermosyphon when 4% (wt) fly ash containing nanofluid was used to replace deionized water at a heat load of 200W and with a cooling water flow rate of 5g/s.