Influence of Flow Turbulence on Heat Transfer Efficiency in Thermal Power Installations

Abstract

The efficiency of thermal power installations directly depends on the intensity of heat exchange processes between heat carriers circulating within heating, cooling, and energy transfer systems. In most modern thermal systems—such as steam and hot-water boilers, heat exchangers, economizers, condensers, feedwater heaters, and components of district heating networks — the hydrodynamic conditions of the working fluid flow play a decisive role. It is well known that the flow structure, its velocity, direction, and the presence of turbulent pulsations and secondary vortices largely determine the rate of heat transfer from one medium to another. In hydro gas dynamics theory, two main flow modes are distinguished: laminar and turbulent. Laminar flow is characterized by an orderly movement of fluid layers, while turbulent flow is marked by a chaotic and continuously varying velocity field, featuring pulsations, vortex structures, and energy exchanges between flow layers. These pulsating motions promote active mixing of liquid or gas particles, which, in turn, enhances heat transfer intensity. As a result, turbulent flows can transfer heat much faster than laminar ones, even at the same average flow velocities. However, turbulence also has negative consequences. The increased chaotic motion of particles leads to higher flow resistance and, consequently, to greater hydraulic energy losses. This means that maintaining the required flow velocity demands higher energy consumption for pumping the working fluid, which reduces the overall efficiency of the system. Thus, the challenge lies in finding a compromise between increasing heat transfer intensity and minimizing pressure losses.