Thermodynamic analysis of combined power system using trilateral cycle and organic rankine cycle

Many methods are used to generate power by using heat energy of renewable energy sources or waste heat energy. One of the most widely used of these methods is the Organic Rankine cycle. It is intended to be renewed using the Trilateral cycle / Organic Rankine cycle or for more purposes than waste heat energy. For this purpose, thermodynamic analyzes were carried out with the help of Engineering Equations Solition (EES) program by examining the structures of the recuperative Trilateral cycle - Organic Rankine cycle, Trilateral cycle - Organic Rankine cycle and Organic Rankine cycle - Organic Rankine cycle. For combined power systems, the best fluid pairs that maximize the system performance at different temperatures of the geothermal source and low temperature evaporator were determined, and the results obtained for all three systems were compared using these determined fluid pairs. It was determined which system's performance was better for the studied conditions. Energy analysis of three combined power cycles at different temperature values of geothermal source and low temperature evaporator. Depending on the operating fluids used in the cycles and the system operating conditions, it was investigated in which combined power system the highest thermal efficiency and power output values will be obtained. According to the results of the research, it was determined that there are fluid pairs that maximize the thermal efficiency and / or net power obtained from the system for each working condition. It was found that as the temperature of the geothermal source or low temperature cycle evaporator increased, the thermal efficiency of the combined power system investigated increased. For each temperature of the geothermal source, it was determined that there is a low temperature cycle evaporator temperature that maximizes the net power of the combined power system. The net power output of ORC-ORC was determined to be almost the same or until 23.5 % higher than from other investigated systems, depending on the operating conditions, so the use of the Organic Rankine cycle - Organic Rankine cycle combined power system recomended for the studied operating conditions.