Analýza vlivu tloušťky úsad na koeficient prostupu tepla

Abstract

The thesis focuses on the impact of fouling on the quality of heat transfer efficiency in a heat exchanger and proposes its optimization by thermally equivalent replacement of finned tubes with smooth tubes. The theoretical part provides a brief description of various types of heat exchangers based on their construction and the flow direction of heat transfer media. Subsequently, heat transfer methods in exchangers are presented, including the formulation of the energy equation. Given the use of the simulation software ANSYS Fluent, the thesis also outlines the basic principles of numerical simulations, including descriptions of turbulence models. In relation to heat transfer, the importance of the boundary layer and its influence on the accuracy of numerical simulations is emphasized. The practical part deals with the analysis and comparison of the thermophysical parameters of a heat exchanger with finned tubes and one whose tubes are affected by external corrosion and anhydrite fouling. In the final part of the thesis, the fouling factor for the contaminated heat exchanger geometry was determined using an iterative method, and a thermally equivalent replacement of finned tubes with smooth tubes was carried out.