Experimental evaluation of heat transfer improvement using ceramic nanofluids in a concentric tube heat exchanger

Abstract This paper is an experimental study of the heat transfer of silicon carbide (SiC) and boron nitride (BN) nanoparticles in a tube-in-tube (TIT) heat exchanger setup. SiC nanoparticles (40–60 nm) and BN nanoparticles (30–50 nm) were dispersed in water with a maximum volume concentration of 2.0 vol%. Thermal conductivity improvement was 7.30% at 0.2 vol% concentration of BN nanofluid and 4.20% of SiC nanofluid. Relative to this, the convective heat transfer performance of SiC nanofluids was better as a 24.6% enhancements in the heat transfer coefficient was attained compared to the base fluid. Of all the concentrations tested, the best concentration of the two types of nanoparticles was found to be 0.2 vol% concentration. The increase in flow rate (0.3 to 0.7 m 3 /h) led to an increase in the heat transfer efficiency by 92%. Nevertheless, the rate of erosion was the highest at flow rates exceeding 0.084 m 3 /h, which explains the importance of a close control of operations. Altogether, SiC nanofluids with the concentration of 0.2 vol% can manifest a high potential of enhancing industrial cooling systems and considerations of erosion to facilitate sustainable thermal management.