摘要：Heat transfer mechanisms and their thermal performances need to be comprehensively studied in order to optimize efficiency and minimize energy *** nanoparticles in the base fluid are investigated to upgrade the thermal performance of heat *** this numerical study,a finned shell and tube heat exchanger has been designed and different volume concentrations of nanofluid were tested to determine the effect of utilizing nanofluid on heat ***_(2)O_(3)/water nanofluids with volume concentration of 1%,1.5% and 2% were utilized as heat transfer fluid in the heat exchanger and the obtained results were compared with pure *** Fluent software as a CFD method was employed in order to simulate the mentioned *** simulation results indicated the successful utilization of nanofluid in the heat ***,increasing the ratio of Fe_(2)O_(3) nanoparticles caused more increment in thermal energy without important pressure ***,it was revealed that the highest heat transfer rate enhancement of 19.1% can be obtained by using nanofluid Fe_(2)O_(3)/water with volume fraction of 2%.