HEAT TRANSFER RESEARCH, cilt.48, sa.5, ss.419-434, 2017 (SCI-Expanded)
The aim of this study is to investigate the effects of MgO nanofluid on the thermal performance of parallel and cross-flow concentric tube heat exchangers. A parallel (PFCTHE) or a cross-flow (CFCTHE) concentric tube heat exchanger was selected in these experiments, and its thermal performance was improved with the fluid. The MgO nanofluid/water and water/waterhot/cold running fluids were used for monitoring the differences in the performance of the heat exchangers. The Triton X-110 surface active agent was added to the fluid to prepare 2% ( wt.) concentration of the MgO nanofluid. The heat exchanger is of double-pipe type with the hot water flowing through the central tube while the cooling water flows through the annular space. A double-pipe heat exchanger with concurrent or countercurrent flow was utilized along with all auxillary equipment and instrumentation for the determination of the surface and overall heat transfer coefficients during turbulent flow. When the MgO nanofluid was used as the running fluid, an improvement of 33.4% and 20.4% was recorded for the efficiency of the PFCTHE and CFCTHE, respectively.