The course "Thermal Turbines I" extends the knowledge of fundamental physical processes in the transformation of thermal or pressure energy into the mechanical power, and vice versa in the transformation of mechanical power into thermal or pressure energy, acquired in the previous course of Turbo-machines. The lectures are concerned with principles and properties of direct and indirect thermal cycles in working fluids with and without changing their phase. A sufficient range of lectures is devoted to the study of processes and design possibilities to reach the highest possible efficiency and reliability of steam turbines, gas turbines and turbo-compressors. Also dealt with are the design, operational, economic and environmental impacts. The students will learn the basics and their application in the design of thermal turbines and turbo-compressors. They will be made familiar with the currently results and with future prospects.