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Spray cooling characteristics of nanofluids for electronic power devices.

Hsieh SS, Leu HY, Liu HH - Nanoscale Res Lett (2015)

Bottom Line: The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein.The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm.The heat transfer removal rate can reach up to 274 W/cm(2) with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10(-4) kg/cm(2)s.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Electromechanical Engineering, National Sun Yat-Sen University, Kaohsiung, 80424 Taiwan.

ABSTRACT
The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle volume fraction and mass flow rate of the liquid on the surface heat flux, including critical heat flux (CHF), are explored. Both steady state and transient data are collected for the two-phase heat transfer coefficient, boiling curve/ cooling history, and the corresponding CHF. The heat transfer removal rate can reach up to 274 W/cm(2) with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10(-4) kg/cm(2)s.

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Cooling curves for the present three fluids used.
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Fig6: Cooling curves for the present three fluids used.

Mentions: Moreover, as the nanofluids were sprayed, Ag/or MCNT nanoparticles began to stick to the heated surface. Subsequent impinging spray droplets dispersed some of these nanoparticles from the point of direct impact on the surface but not completely off the heated surface. Therefore, a circular band of nanoparticles was observed sticking around the regime of direct impact of the spray cone on the heated surface. Based on the above statements, the cooling rate of each of the three volume concentrations of nanofluids differed. The data strongly indicated dependence of the cooling performance of the nanofluids on the nanoparticle volume concentration. If nanoparticles can be prevented from sticking to the heated surfaces, enhanced cooling performance could be achieved with nanofluids. Figure 6 shows a summary of the results for cooling curves for the base fluid (DI water) for three different mass flux MCNT nanofluids (G = 11.9 × 10−4 kg/cm2s) and Ag nanofluids (G = 11.9 × 10−4 kg/cm2s) altogether in the same plot. Although the effect of the nanoparticle volume fraction is limited, differences among them can be clearly noted again. The effect of nanofluids on cooling curves is quite significant as well, especially when the cooling time is less than 120 s.Figure 6


Spray cooling characteristics of nanofluids for electronic power devices.

Hsieh SS, Leu HY, Liu HH - Nanoscale Res Lett (2015)

Cooling curves for the present three fluids used.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385298&req=5

Fig6: Cooling curves for the present three fluids used.
Mentions: Moreover, as the nanofluids were sprayed, Ag/or MCNT nanoparticles began to stick to the heated surface. Subsequent impinging spray droplets dispersed some of these nanoparticles from the point of direct impact on the surface but not completely off the heated surface. Therefore, a circular band of nanoparticles was observed sticking around the regime of direct impact of the spray cone on the heated surface. Based on the above statements, the cooling rate of each of the three volume concentrations of nanofluids differed. The data strongly indicated dependence of the cooling performance of the nanofluids on the nanoparticle volume concentration. If nanoparticles can be prevented from sticking to the heated surfaces, enhanced cooling performance could be achieved with nanofluids. Figure 6 shows a summary of the results for cooling curves for the base fluid (DI water) for three different mass flux MCNT nanofluids (G = 11.9 × 10−4 kg/cm2s) and Ag nanofluids (G = 11.9 × 10−4 kg/cm2s) altogether in the same plot. Although the effect of the nanoparticle volume fraction is limited, differences among them can be clearly noted again. The effect of nanofluids on cooling curves is quite significant as well, especially when the cooling time is less than 120 s.Figure 6

Bottom Line: The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein.The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm.The heat transfer removal rate can reach up to 274 W/cm(2) with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10(-4) kg/cm(2)s.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Electromechanical Engineering, National Sun Yat-Sen University, Kaohsiung, 80424 Taiwan.

ABSTRACT
The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle volume fraction and mass flow rate of the liquid on the surface heat flux, including critical heat flux (CHF), are explored. Both steady state and transient data are collected for the two-phase heat transfer coefficient, boiling curve/ cooling history, and the corresponding CHF. The heat transfer removal rate can reach up to 274 W/cm(2) with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10(-4) kg/cm(2)s.

No MeSH data available.


Related in: MedlinePlus