Document Type : Research Paper
Transport Phenomena and Nanotechnology Laboratory, Department of Chemical Engineering, College of Eng., University of Tehran, Tehran, I. R. Iran
Department of Chemical Engineering, College of Eng., University of Tehran, Tehran, I. R. Iran
The objective of the present study is the synthesis of MWCNT-TiO2 hybrid nanostructures by solvothermal synthesis method with TiCl4 as precursor. The heat transfer enhancement due to the use of MWCNT-TiO2 nanofluid was investigated. As-prepared hybrid materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that MWCNTs were uniformly decorated with anatase nanocrystals. The heat transfer performance of the plate heat exchanger (PHE) was investigated using MWCNT-TiO2 nanofluid at various volume flow rates, a wide range of concentrations and inlet temperatures. The performance is discussed in terms of heat transfer coefﬁcient ratio. The results showed that the heat transfer coefﬁcient of the nanofluid was more than that of the base fluid (Distilled Water). The heat transfer coefﬁcient was enhanced with increasing the nanofluid concentration from 0.02 to 0.08 wt.% and volume flow rate from 2 to 3.5 LPM. Conversely, the heat transfer coefﬁcient decreased with increasing the nanofluid inlet temperature from 36 to 60oC.