Abstract
Heat transfer is a key process in a multitude of industrial and scientific applications such as power engineering, chemical engineering, and thermal engineering. Optimisation of heat transfer processes in heat exchangers is becoming an increasingly important task to improve efficiency and reduce energy costs. In the study, considerable attention has been given to the development and application of heat transfer intensification methods aimed at improving heat transfer and reducing hydraulic losses. The development of new surface geometries such as microirregularities, microchannels and structures with increased surface area contributes to heat transfer intensification. This increases heat transfer by improving flow turbulence and reducing thermal resistance at the heat transfer interface. When transporting oil at low ambient temperatures, additional resources are required to heat the oil, for which heat transfer apparatus (HTA) is used. Hot pumping of oil reduces energy losses during its transport. In this paper, the logarithmic mean temperature difference method modified for the case of variable viscosity and computational fluid dynamics (CFD) methods using Reynolds-averaged Navier-Stokes (RANS) model and k-ω turbulence model are used to calculate the heat exchanger. The laminar-turbulent transition is taken into account and the Nusselt number along the TOA tube is calculated.