Experiment and theory for acetylene adsorption in transformer oil

Abstract

Abstract A series of nanofluids were prepared by incorporating titanium dioxide (TiO2), carbon nanotube (CNTs) and zinc oxide (ZnO) into transformer oils to eliminate acetylene (C2H2) bubbles, and elimination of the partial discharge (PD). The adsorption of C2H2 molecules onto three model nanoparticles (TiO2, CNTs and ZnO) were simulated based on density functional theory (DFT) calculations, and then compared with experimental data. Theoretically, TiO2 showed the highest capacity for adsorbing C2H2 molecules among the studied nanoparticles, as featured by a high adsorption energy (3.61\xa0eV), high charge transfer (1.34\xa0eV), and low equilibrium distance between TiO2 and C2H2 (2.55\xa0A). The maximum breakdown voltage was obtained at optimum CNTs, ZnO and TiO2 contents of 0.01, 0.01, and 0.075\xa0wt.%, respectively. Experimental results confirmed theoretical calculations; so that TiO2 had the highest efficiency of C2H2 adsorption (71%), while ZnO and CNTs could adsorb acetylene by 64% and 17%, respectively. Moreover, CNTs and ZnO unenviably decreased the breakdown voltage by 77% and 27%, respectively, while TiO2 increased it by 13%. Therefore, TiO2-based nanofluids not merely decreased the adverse effects of PD, but also improved the electrical properties of the transformer oil.