Mohammad Mokhtari - School of mechanical Engineering, University of Tehran, Tehran
Mahdi Sahebi - School of mechanical Engineering, Qom University of technology, Qom

In this paper, the problem of increasing the heat transfer by nanofluid and comparing the types of nanofluid in heat exchangers, which are in the form of a tube bundle with a staggered arrangement, have been investigated. The numerical investigation has been used to solve the equations of the problem, and the flow is considered to be turbulence. Nanoparticles of Aluminum oxide, titanium oxide, copper oxide and copper dispersed in water base fluid, and nanoparticles of aluminum oxide, titanium oxide and copper nanoparticles dispersed in ethylene glycol base fluid were compared. The results indicate that the heat transfer will be increased by adding nanoparticles to the base fluid. In the cases with water base fluid, the Cu-water nanofluid has the highest heat transfer rate compared to the rest of the nanofluids, but the Al۲O۳-water nanofluid has the highest thermal efficiency. Also, the Al۲O۳-ethylene glycol has the highest heat transfer rate and thermal performance in nanofluids with ethylene glycol base fluid. On the other hand, it has been proved that increasing heat transfer coefficient and thermal efficiency of nanofluids with ethylene glycol base fluid is much higher than nanofluids with water base fluid

Nanofluid, Tube bundle, Heat transfer, Thermal efficiency, Turbulence