ENHANCEMENT OF THERMAL PERFORMANCE OF DOUBLE PIPE HEAT EXCHANGER BY USING NANOFLUID

Abstract

In this paper, the performance of double pipe heat exchanger was studied experimentally with two flow arrangements (counter and parallel flow) and two types of nanofluid as a cooling fluid. A (20 nm) nanoparticles of (Al2O3 and TiO2) are used with deionized water as base fluid. The nanoparticles volume concentrations which studied were (0.05, 0.1, 0.15, 0.2, 0.3) % and flow rates were (0.5, 1, 1.5, 2) L/min for water and NF. Hot fluid (water) and cold fluid (Nanofluid) flow in heat exchanger with constant inlet temperature of 59.3 C° and 30.7 C° respectively, so the two fluids flowing with constant inlet velocity. The experimental results showed that the nanofluid absorbed heat more than the water at low flow rate, which would lead to improve the thermal performance of heat exchanger due to enhancing of thermo physical properties of these fluids. Also, it showed that the heat transfer rate increased with the increasing of nanoparticles concentration. In the same context, one notice the effect of the type of nanoparticles on the rate of heat transfer, where Al2O3-water NF had heat transfer rate greater than that for TiO2-water NF. In addition, it showed that the maximum heat transfer coefficient (HTC) at 0.3% volume concentration was enhanced by 18.25% and 15.5% for AL2O3-water nanofluid and TiO2-water nanofluid respectively with 20 nm diameter.