High temperature nanofluids based on therminol 66 for improving the heat exchangers power in gas refineries

One of the problems that we face in many industries and research projects is the need for heat transfer in a short time and with high intensity. Most of the previous studies have been conducted on the low-temperature nanofluids (T <= 100 degrees C) such as water and various oils, and the high-temperature fluids are largely neglected. In this research, therminol 66 as a high-temperature oil was selected as the base fluid. Therminol 66 is used in the oil and gas industry for heat transfer in heat exchangers. In this research, SiO2 and Al2O3 nanoparticles were added at the concentration of 0.1 wt% to the base fluid. The basic thermophysical properties, including density, viscosity, and specific heat capacity of the samples, were measured. A high-temperature laboratory system was employed to evaluate the performance of nanofluids in the temperature range of 280-320 degrees C. The results showed that addition of nanoparticles at the concentration of 0.1 wt% did not lead to a considerable change in the density and viscosity of the base fluid, but the specific heat capacity of the nanofluid at high temperatures was improved compared to the base fluid. The results of the heat exchanger test also showed that the use of nanoparticles considerably improved the exchanger efficiency, such that it was increased at one state up to 88% compared to the base fluid.