Experimental investigation of double pipe heat exchanger using Al2o3 and Tio2 Nanofluid

Abstract EN

Laminar counter and parallel ^ows in a double pipe heat exchanger is studied experimentally using two types of nano^uids as a cooling medium.

The nano^uids consist of Al2O3 and TiO2 nanoparticles, which were added to the base ^uid (deionized water).

The average diameter of nanoparticles is approximately 20 nm for both Al2O3 and TiO2 nanoparticles.

The volume concentrations of nano^uid was varied with a range of (0.05- 0.3) percentage and the ^ow rates of the base and nano^uids were varied with a range of (0.5-2) L/min.

Hot fluid (water) is flowing in the inner tube of heat exchanger with constant inlet temperature and the cold fluid (nanofluid) is introduced in the outer tube with constant inlet temperature.

Compared to the base ^uid, the results showed that the nano^uid containing AI2O3 and TiO2 nanoparticle exhibits enhanced heat transfer, and this enhancing is clearly rejected by the increase in the inside and outside heat transfer coefficients, thus the overall heat transfer coefficient, where the percentage enhancement in heat transfer coefficient of nano^uid per base ^uid is (18.25 and 15.5) % for Al2O3-water and TiO2-water nano^uid respectively.

The enhanced performance of heat exchanger is due to high value of thermo physical properties of ^uid when dispersing nanoparticles in the base ^uid.