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Application of silver nanofluid containing oleic acid surfactant in a thermosyphon economizer.

Parametthanuwat T, Rittidech S, Pattiya A, Ding Y, Witharana S - Nanoscale Res Lett (2011)

Bottom Line: The volumetric flow rates for the coolant (in the condenser) were 1, 2.5, and 5 l/min.The operating temperatures were 60, 70, and 80°C.It was further found that the effectiveness of nanofluid and the OA containing nanofluids were superior in effectiveness over water in all experimental conditions came under this study.

View Article: PubMed Central - HTML - PubMed

Affiliation: Heat-Pipe and Thermal Tools Design Research Unit (HTDR), Division of Mechanical Engineering, Faculty of Engineering, Mahasarakham University, Thailand. s_rittidej@hotmail.com.

ABSTRACT
This article reports a recent study on the application of a two-phase closed thermosyphon (TPCT) in a thermosyphon for economizer (TPEC). The TPEC had three sections of equal size; the evaporator, the adiabatic section, and the condenser, of 250 mm × 250 mm × 250 mm (W × L × H). The TPCT was a steel tube of 12.7-mm ID. The filling ratios chosen to study were 30, 50, and 80% with respect to the evaporator length. The volumetric flow rates for the coolant (in the condenser) were 1, 2.5, and 5 l/min. Five working fluids investigated were: water, water-based silver nanofluid with silver concentration 0.5 w/v%, and the nanofluid (NF) mixed with 0.5, 1, and 1.5 w/v% of oleic acid (OA). The operating temperatures were 60, 70, and 80°C. Experimental data showed that the TPEC gave the highest heat flux of about 25 kW/m2 and the highest effectiveness of about 0.3 at a filling ratio of 50%, with the nanofluid containing 1 w/v% of OA. It was further found that the effectiveness of nanofluid and the OA containing nanofluids were superior in effectiveness over water in all experimental conditions came under this study. Moreover, the presence of OA had clearly contributed to raise the effectiveness of the nanofluid.

No MeSH data available.


Related in: MedlinePlus

Relationship between operating temperature and effectiveness. Volumetric flow rate = 1 l/min, filling ratio = 50%.
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Figure 9: Relationship between operating temperature and effectiveness. Volumetric flow rate = 1 l/min, filling ratio = 50%.

Mentions: The experimental data and theoretical predictions for the effect of operating temperature on the effectiveness of TPEC are demonstrated in Figure 9. The maximum effectiveness of 0.3 has occurred with the OA concentration of 1 w/v% and at 80°C. The effectiveness increased with the operating temperature. This is due to the onset of boiling in the TPCT and also due to the reduction of surface tension that made the bubbles easier to move upwards. In particular the addition of OA further reduced the surface tension that would cause early boiling. Figure 9 further shows that at 80°C, the effectiveness of water was 80% lower than the theory, whereas the effectiveness of NF + OA 1 w/v% was only 40% lower. Hence, the NF + OA has performed better than water. This demonstrates the benefit of NF + OA as a working fluid in TPCT.


Application of silver nanofluid containing oleic acid surfactant in a thermosyphon economizer.

Parametthanuwat T, Rittidech S, Pattiya A, Ding Y, Witharana S - Nanoscale Res Lett (2011)

Relationship between operating temperature and effectiveness. Volumetric flow rate = 1 l/min, filling ratio = 50%.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211402&req=5

Figure 9: Relationship between operating temperature and effectiveness. Volumetric flow rate = 1 l/min, filling ratio = 50%.
Mentions: The experimental data and theoretical predictions for the effect of operating temperature on the effectiveness of TPEC are demonstrated in Figure 9. The maximum effectiveness of 0.3 has occurred with the OA concentration of 1 w/v% and at 80°C. The effectiveness increased with the operating temperature. This is due to the onset of boiling in the TPCT and also due to the reduction of surface tension that made the bubbles easier to move upwards. In particular the addition of OA further reduced the surface tension that would cause early boiling. Figure 9 further shows that at 80°C, the effectiveness of water was 80% lower than the theory, whereas the effectiveness of NF + OA 1 w/v% was only 40% lower. Hence, the NF + OA has performed better than water. This demonstrates the benefit of NF + OA as a working fluid in TPCT.

Bottom Line: The volumetric flow rates for the coolant (in the condenser) were 1, 2.5, and 5 l/min.The operating temperatures were 60, 70, and 80°C.It was further found that the effectiveness of nanofluid and the OA containing nanofluids were superior in effectiveness over water in all experimental conditions came under this study.

View Article: PubMed Central - HTML - PubMed

Affiliation: Heat-Pipe and Thermal Tools Design Research Unit (HTDR), Division of Mechanical Engineering, Faculty of Engineering, Mahasarakham University, Thailand. s_rittidej@hotmail.com.

ABSTRACT
This article reports a recent study on the application of a two-phase closed thermosyphon (TPCT) in a thermosyphon for economizer (TPEC). The TPEC had three sections of equal size; the evaporator, the adiabatic section, and the condenser, of 250 mm × 250 mm × 250 mm (W × L × H). The TPCT was a steel tube of 12.7-mm ID. The filling ratios chosen to study were 30, 50, and 80% with respect to the evaporator length. The volumetric flow rates for the coolant (in the condenser) were 1, 2.5, and 5 l/min. Five working fluids investigated were: water, water-based silver nanofluid with silver concentration 0.5 w/v%, and the nanofluid (NF) mixed with 0.5, 1, and 1.5 w/v% of oleic acid (OA). The operating temperatures were 60, 70, and 80°C. Experimental data showed that the TPEC gave the highest heat flux of about 25 kW/m2 and the highest effectiveness of about 0.3 at a filling ratio of 50%, with the nanofluid containing 1 w/v% of OA. It was further found that the effectiveness of nanofluid and the OA containing nanofluids were superior in effectiveness over water in all experimental conditions came under this study. Moreover, the presence of OA had clearly contributed to raise the effectiveness of the nanofluid.

No MeSH data available.


Related in: MedlinePlus