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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 heat flux. Volumetric flow rate = 1 l/min, filling ratio = 50%.
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Figure 5: Relationship between operating temperature and heat flux. Volumetric flow rate = 1 l/min, filling ratio = 50%.

Mentions: Dependence of the operating temperature on the heat flux of TPCE filled with the silver nanofluid mixed with oleic acid (NF + OA) is shown in Figure 5. Also shown are the data for water. In all cases the NF + OA shows superior performance than pure water. The maximum heat flux of 12 kW/m2 has occurs with the OA 1 w/v% nanofluid at the operating temperature of 80°C. From this it can be seen that when the temperature was increased from 60 to 80°C, the heat flux had increased by different proportions. At this temperature interval, the pool boiling occurred that resulted high heat transfer rates. Nanoparticles present in the liquid can increase the surface area for heat absorption. As a consequence the liquid will raise its temperature quicker and start to boil. In the case of NF + OA, the OA will stabilize the nanoparticles by uniformly distributing them. This may cause increase in the thermal conductivity of the liquid, which in turn helps to raise the liquid temperature.


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 heat flux. 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 5: Relationship between operating temperature and heat flux. Volumetric flow rate = 1 l/min, filling ratio = 50%.
Mentions: Dependence of the operating temperature on the heat flux of TPCE filled with the silver nanofluid mixed with oleic acid (NF + OA) is shown in Figure 5. Also shown are the data for water. In all cases the NF + OA shows superior performance than pure water. The maximum heat flux of 12 kW/m2 has occurs with the OA 1 w/v% nanofluid at the operating temperature of 80°C. From this it can be seen that when the temperature was increased from 60 to 80°C, the heat flux had increased by different proportions. At this temperature interval, the pool boiling occurred that resulted high heat transfer rates. Nanoparticles present in the liquid can increase the surface area for heat absorption. As a consequence the liquid will raise its temperature quicker and start to boil. In the case of NF + OA, the OA will stabilize the nanoparticles by uniformly distributing them. This may cause increase in the thermal conductivity of the liquid, which in turn helps to raise the liquid temperature.

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