Experimental and Theoretical Study to Increase the Solar-Organic Rankine Cycle Efficiency

Abstract

Under conditions of high climate temperature and environmental pollution, scientists are turning to the use of new and renewable energy. The solar Organic Rankin Cycle (ORC) is greatest technology for converting low or medium-temperature energy sources into electricity. For the purpose of generating steam from solar energy to power the organic Rankin cycle a system consists of solar pond, flat plate collector and parabolic dish was designed, implemented, and tested to use in organic Rankin cycle (ORC). The novelty in the present work is the use of the solar pond as storage of heat that does not lose because the salinity gradient middle layer in the pond does not allow heat to pass through it, as well as the use of reheating to enhance the thermodynamic efficiency. Also, an analytical model has been made to enhance the output power and efficiency of the solar thermal ORC according to some organic control criteria. A Cycle of solar thermal power plants (ORC) is simulated with four refrigerants, R144a, R123, R124 and R245fa of working fluid’s performance. The cycle net-specific work can be verified at the highest efficiency as a function of turbine extraction numbers, over-temperature, and evaporation temperature. Superheated steam was obtained at a temperature of 327 °C to be used in the Rankin cycle of the solar energy system which is generated in this work. The maximum output power improvement is 9% when using the working fluid R123 for R124, 5.5% for R245fa, and approximately 2.8 for R144a. And the thermal efficiency of ORC is higher with R123 compared to 144a by about 2.2%. Furthermore, it also concluded that both inlet and outlet temperatures of a turbine are very important factors that affect the operational performance of organic Rankin cycle power generation systems.