Performance Evaluation and Comparative Study on Effectiveness for a Shell and Tube Heat Exchanger with Baffles using Nanofluids

Abstract

Nanoparticles attracted many researchers because of their significant heat transfer newlineenhancement properties in various applications. The nanoparticles have variable newlineproperties and a high specific surface area, which enhance heat exchange between fluids newlineand their particles at different volume concentrations. This research work provides the newlineoutcomes of an experiment on the coefficient of overall heat transfer (Uo) and newlineeffectiveness (and#949;) in shell and tube heat exchanger (STHE) with a 25% baffle-cut. It uses newlineAl2O3-DW, CuO-DW and Hybrid (Al2O3-CuO-DW) nanofluids consisting of base fluid newlinedistilled water with Al2O3, CuO and hybrid nanoparticles (Al2O3-CuO) at 0.05, 0.1 and newline0.2 % of volume fractions with varied mass flow nanofluids between 0 to 1 lpm. Using a newlinetwo-step method, adding a weight fraction of 0.1, 0.15 and 0.125 percent of SDBS newline(Sodium dodecylbenzene sulfonate) as a surface-active agent to each volume newlineconcentration of Al2O3-DW, CuO-DW and Hybrid nanofluids, respectively for better newlinestability. Increasing the volume fractions of the nanoparticles in the base fluid DW newlineenhances the thermophysical properties like density, thermal conductivity and dynamic newlineviscosity of the nanofluids, but it decreases the specific heat (Cp) of the nanofluids. newlineOverall, this resulted in enhancing the heat transfer characteristics of nanofluids. newlineAl2O3-DW, CuO-DW and Hybrid nanofluids at different concentrations in parallel newlineand counter flow variations of the STHE enhance the Uo and and#949; compared to water, but newlinecounter flow provides higher effectiveness. During counterflow of STHE, the maximum newlineeffectiveness (and#949;) values are 2.09%, 2.93%, 4.03% for 0.05% concentration, 2.79%, newline3.85%, 5.09% for 0.1% concentration and 4.16%, 5.66%, 7.16% for 0.2% concentration newlineof Al2O3-DW, CuO-DW and hybrid nanofluids at 0.6 lpm mass flow respectively, newlinecompared to water. Among water, Al2O3-DW, CuO-DW and hybrid nanofluids newlinecomparative study at various selected concentrations in parallel and counterflow of newlineSTHE, the hybrid nanofluid will give maxim