Effect of CuO Nanoparticles in Enhancing the Thermal Conductivities of Monoethylene Glycol and Paraffin Fluids

Abstract

The effect of CuO nanoparticles on the thermal conductivities of paraffin and monoethylene glycol (MEG) was investigated. An enhancement in the effective thermal conductivity was found for both fluids. This enhancement was studied with regard to various factors: nanoparticle concentration, nanoparticle size, and base-fluid type. For both base fluids, an improvement in thermal conductivity was found as nanoparticle concentration increased; this was attributed to an increase in particle-to-particle interactions. It was also found that, as the particle size was reduced, there was also an improvement in the thermal conductivities of the fluids. A reduction in nanoparticle size leads to an increase in the Brownian motion of the particles, which also causes more particle-to-particle interactions. The role that the base fluid plays in the observed enhancement is complex. Lower fluid viscosities are believed to contribute to greater enhancement, but a second effect, the interaction of the fluid with the nanoparticle surface, can be even more important. Nanoparticle−liquid suspensions generate a shell of organized liquid molecules on the particle surface. These organized molecules more efficiently transmit energy, via phonons, to the bulk of the fluid. The efficient energy transmission results in enhanced thermal conductivity. The experimentally measured thermal conductivities of the suspensions were compared to a variety of models. None of the models were found to adequately predict the thermal conductivities of the nanoparticle suspensions.

Temperature-dependent thermal conductivity and viscosity of synthesized α-alumina nanofluids

“…Fig. 9 Comparison with previously reported work and our proposed work on temperature-dependent nanofluid thermal conductivity ratio for alumina nanofluid (Maxwell 1954;Hamilton and Crosser 1962;Wang et al 2008;Beck et al 2009;Moghadassi et al 2010;Kleinstreuer and Feng 2011;Chon et al 2005;Li and Peterson 2006) Due to the particle volume concentration the dynamic viscosity of nanofluid has been increased and as temperature increases viscosity decreases, which is concluded by Nguyen et al (Nguyen et al 2008;Chandrasekar et al 2010). This process is the witness for the particle suspension beyond the critical temperature, which caused by the hysteresis phenomenon.…”

“…Basic classical models are mainly giving conclusions regarding particle size, shape, concentration, which helps to assume heat transfer in particles as well as in fluid (Wang et al 2008). Beck et al (2009) and Moghadassi et al (2010) observed that the thermal conductivity will upgrade with the decreasing of nanoparticle size. Kleinstreuer and Feng (2011) established relationship between thermal conductivity and some fundamental parameters like concentration, temperature, particle size which are exceptionally valuable for a nanofluid.…”

Effect of sonication time on enhancement of effective thermal conductivity of nano TiO2–water, ethylene glycol, and paraffin oil nanofluids and models comparisons

“…As the thickness of the interfacial shell increases, there is a corresponding increase in the volume of the interface, which results in greater heat conduction. [26] The viscosity of the fluid and the interfacial thickness of the particle-fluid interface affect the thermal conductivity of nanofluids.…”

Performance of CNT-water nanofluid as coolant fluid in shell and tube intercooler of a LPG absorber tower

“…Therefore, overall heat transfer coefficient and then heat transfer rate increases (Eqs. (5) and (6)). Figs.…”

“…Nanofluids are stable suspension of the nanoparticles in a base fluid like water, ethylene glycol and industrial oils. Nanoparticles can be metallic like Silver [1] and Copper [2], metal oxide like Al 2 O 3 [3] and CuO [4,5] and nonmetallic like SiC [6] and carbon nanotubes (CNT) [7,8]. Nanofluids containing nanoparticles exhibit enhanced the heat transfer characteristics [9][10][11].…”