Abstract

This paper presents a novel, procedure of calculations of simple thermodynamic cycles with the main isothermal expansion process. Calculation assumptions are based on the use of technologically advanced flow devices. Firstly the theoretical Ericsson cycle with description of isothermal process has been presented. Then the calculations for open gas cycle with external combustion chamber, realising Ericsson cycle with upper temperature of 1473 K were carried out, showing the possibilities of turbines with isothermal expansion and achieving record-breaking efficiency. The use of isothermal compression has also been considered. The second, supercritical cycle with organic medium and condensation process also shows predispositions to achieve record-high efficiency at upper cycle temperature of 573 K. For both cycles, graphs of linearized thermodynamic transformations were made as well as graphs of efficiency dependence on the pressure. At the end, unit work of turbines in cycles has been compared and discussed.