8613

7994

كارشناسي ارشد

مهندسي شيمي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مهندسي شيمي

1392

پانزده،79ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

نسرين اعتصامي

محسن نصر اصفهاني

18/12/92

ارجمند مهرباني، مسعود حق شناس فرد

مهندسي شيمي

ID7994

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Investigation of SiO2 water Nanofluid Pool Boiling on Inclined Surface Mina Dadjoo minahiebor@yahoo com Department of Chemical Engineering Isfahan University of Technology Isfahan 84165 83111 Iran Degree M Sc Language Persian Superviser Nasrin Etesami netesami@cc iut ac ir Abstract Nanofluids because of their attractive properties innurmous benefits and application in many fields such as micro electronics transport and biomedical attract researchers have focused on high conduction heat transfer coefficient of nanofluids but have done less efforts to apply nanofluids as a new generation of coolants In present study boiling of water silica nanofluids on circular flat plate heater to observing the effect of inclination angle of heater surface on CHF and BHTC was done The experiments were performed by focusing on surface morphology The nanofluid concentration was between 0 001 0 01 vol and inclination of heater was varied showed CHF increases with nanofluid concentration The CHF enhancement in horizontal configuration for 0 001 0 0025 and 0 005 vol was 25 53 and 65 repectively It was observed BHTC increases with nanofluid concentration in the range of 0 001 0 005 vol but when concentration increase to 0 01 vol BHTC decreases The BHTC enhancement in horizontal configuration for 0 001 0 0025 0 005 and 0 01 vol was between 10 20 62 166 75 177 and 40 153 respectively Discovering the effect of inclination angle of heater surface on boiling on DI water and nanofluid showed with increasing heater bubbles moved along the heater surface and departure of bubbles from heater surface become harder This occurrence decreases BHTC In boiling of DI water CHF decreases by inclination angle of heater surface Insomuch the bubbles sliding on heater surface and coalescence together vapor film formed on heater surface in less heat fluxes and CHF decreased But inclination angle of heater surface had a different effect on CHF of nanofluid so much that CHF increased with inclination angle of heater surface It showed that the effect of nanoparticle deposition on heater surface dominates on bubble movement The Atomic Force Microscopic AFM analysis of heater surface before and after boiling of nanofluid over horizontal and vertical heater surface showed in vertical configuration more uniform nanolayer forms on heater surface that increase CHF Keywords pool boiling nanofluid flat plate inclined surface critical heat flux pool boiling heat transfer coefficient

نسرين اعتصامي

محسن نصر اصفهاني

ارجمند مهرباني، مسعود حق شناس فرد