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Pool boiling of water-Al2O3 and water-Cu nanofluids on horizontal smooth tubes.

Cieslinski JT, Kaczmarczyk TZ - Nanoscale Res Lett (2011)

Bottom Line: Nanoparticles were tested at the concentration of 0.01%, 0.1%, and 1% by weight.The horizontal smooth copper and stainless steel tubes having 10 mm OD and 0.6 mm wall thickness formed test heater.The results indicate that independent of concentration nanoparticle material (Al2O3 and Cu) has almost no influence on heat transfer coefficient while boiling of water-Al2O3 or water-Cu nanofluids on smooth copper tube.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Ecoengineering and Process Apparatus, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland. jcieslin@pg.gda.pl.

ABSTRACT
Experimental investigation of heat transfer during pool boiling of two nanofluids, i.e., water-Al2O3 and water-Cu has been carried out. Nanoparticles were tested at the concentration of 0.01%, 0.1%, and 1% by weight. The horizontal smooth copper and stainless steel tubes having 10 mm OD and 0.6 mm wall thickness formed test heater. The experiments have been performed to establish the influence of nanofluids concentration as well as tube surface material on heat transfer characteristics at atmospheric pressure. The results indicate that independent of concentration nanoparticle material (Al2O3 and Cu) has almost no influence on heat transfer coefficient while boiling of water-Al2O3 or water-Cu nanofluids on smooth copper tube. It seems that heater material did not affect the boiling heat transfer in 0.1 wt.% water-Cu nanofluid, nevertheless independent of concentration, distinctly higher heat transfer coefficient was recorded for stainless steel tube than for copper tube for the same heat flux density.

No MeSH data available.


Related in: MedlinePlus

Scheme of the experimental rig.
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Figure 1: Scheme of the experimental rig.

Mentions: Figure 1 shows a schematic diagram of the experimental apparatus. The test chamber consisted of a cubical vessel made of stainless steel with inside dimensions of 150 × 150 × 250 mm. The horizontal copper and stainless steel tubes having 10 mm OD and 0.6 mm wall thickness formed test heater. The effective length of the test tube was 100 mm. The stainless steel tube was finished with emery paper 400 (Ra = 0.08 μm) and copper tube was polished with abrasive compound (Ra = 0.12 μm). The test tube was cantilever-mounted from the back wall of the test chamber to permit visualization. A resistance cartridge heater was inserted into the test tube to generate heat flux from an electrical power supply. The power supply was adjusted by an electrical transformer. Great care must be exercised with the cartridge heater and temperature measuring instrumentation to ensure good accuracy of the measurement of the inside temperature of the heating cylinder [22]. In the present study, inside the tube, a copper sleeve with 12 grooves at the outside surface to locate the thermocouples was inserted. The copper sleeve was divided into three equal parts, which were separated by three Teflon, 4 mm long, rings. Twelve K-type thermocouples for surface temperature measurements were installed in the grooves. The ends of the thermocouples were placed in the grooves in the middle of the Teflon ring in order to avoid the influence of the heater on the reading from the thermocouples. The detailed geometry of the test tube is shown in Figure 2. The wall temperature tw was calculated from the formula [23](1)


Pool boiling of water-Al2O3 and water-Cu nanofluids on horizontal smooth tubes.

Cieslinski JT, Kaczmarczyk TZ - Nanoscale Res Lett (2011)

Scheme of the experimental rig.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211278&req=5

Figure 1: Scheme of the experimental rig.
Mentions: Figure 1 shows a schematic diagram of the experimental apparatus. The test chamber consisted of a cubical vessel made of stainless steel with inside dimensions of 150 × 150 × 250 mm. The horizontal copper and stainless steel tubes having 10 mm OD and 0.6 mm wall thickness formed test heater. The effective length of the test tube was 100 mm. The stainless steel tube was finished with emery paper 400 (Ra = 0.08 μm) and copper tube was polished with abrasive compound (Ra = 0.12 μm). The test tube was cantilever-mounted from the back wall of the test chamber to permit visualization. A resistance cartridge heater was inserted into the test tube to generate heat flux from an electrical power supply. The power supply was adjusted by an electrical transformer. Great care must be exercised with the cartridge heater and temperature measuring instrumentation to ensure good accuracy of the measurement of the inside temperature of the heating cylinder [22]. In the present study, inside the tube, a copper sleeve with 12 grooves at the outside surface to locate the thermocouples was inserted. The copper sleeve was divided into three equal parts, which were separated by three Teflon, 4 mm long, rings. Twelve K-type thermocouples for surface temperature measurements were installed in the grooves. The ends of the thermocouples were placed in the grooves in the middle of the Teflon ring in order to avoid the influence of the heater on the reading from the thermocouples. The detailed geometry of the test tube is shown in Figure 2. The wall temperature tw was calculated from the formula [23](1)

Bottom Line: Nanoparticles were tested at the concentration of 0.01%, 0.1%, and 1% by weight.The horizontal smooth copper and stainless steel tubes having 10 mm OD and 0.6 mm wall thickness formed test heater.The results indicate that independent of concentration nanoparticle material (Al2O3 and Cu) has almost no influence on heat transfer coefficient while boiling of water-Al2O3 or water-Cu nanofluids on smooth copper tube.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Ecoengineering and Process Apparatus, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland. jcieslin@pg.gda.pl.

ABSTRACT
Experimental investigation of heat transfer during pool boiling of two nanofluids, i.e., water-Al2O3 and water-Cu has been carried out. Nanoparticles were tested at the concentration of 0.01%, 0.1%, and 1% by weight. The horizontal smooth copper and stainless steel tubes having 10 mm OD and 0.6 mm wall thickness formed test heater. The experiments have been performed to establish the influence of nanofluids concentration as well as tube surface material on heat transfer characteristics at atmospheric pressure. The results indicate that independent of concentration nanoparticle material (Al2O3 and Cu) has almost no influence on heat transfer coefficient while boiling of water-Al2O3 or water-Cu nanofluids on smooth copper tube. It seems that heater material did not affect the boiling heat transfer in 0.1 wt.% water-Cu nanofluid, nevertheless independent of concentration, distinctly higher heat transfer coefficient was recorded for stainless steel tube than for copper tube for the same heat flux density.

No MeSH data available.


Related in: MedlinePlus