Abstract:

One of the most widely used to generate power using heat energy or waste heat energy from renewable energy sources is the Organic Rankine cycle. The Trilateral Cycle differs from the Organic Rankine cycle in that it uses an expander instead of a turbine element. In this study, the structures of Trilateral cycle - Organic Rankine cycle and Organic Rankine cycle - Organic Rankine cycle combined power systems were examined and thermodynamic analyzes were made with the help of Engineering Equation Solver (EES) program. For each combined power system, the fluid pairs that maximize the system performance at different temperatures of the geothermal source and sub-cycle evaporator were determined and the results of the combined power systems using these determined fluid pairs were compared. According to the results of the research, it was determined that there are pairs of fluids that maximize the thermal efficiency and / or the net power obtained from the system for each operating condition. It was determined that at temperatures of 100-280 oC of the geothermal resource, the combined power system was evaporating hot, which maximized the net power. Depending on the working conditions, it was determined that the net power output of ORC-ORC was up to until 23.5 % higher than TLC-ORC.

Keywords: