Performance Investigation and Working Fluid Evaluation for Organic Rankine Cycle Power Plant

In the fields of energy conversion, the organic Rankine cycle (ORC) is an effective technology for power generation when using low-to-medium-grade heat sources (i.e., solar energy). One of the fundamental aspects of the ORC design and optimization procedure is fluid selection. The current study evaluates the energetic performance of a simple organic Rankine cycle (SORC) with an emphasis on environmental features. Based on the first law of thermodynamics, an Engineering Equation Solver (EES) environment was used to build a steady-state model for numerical analysis. Three working fluids with zero ozone depletion potential (ODP) and low global warming potential (GWP), n-pentane, toluene, and cyclohexane were selected for analysis. This screening is performed based on pressure ratio and evaporation pressure and condenser temperature. The final results show that selecting the appropriate working fluid is critical to optimizing efficiency and net electrical power production. Toluene has the highest thermal efficiency of the tested fluids, at 0.234%, compared to 0.203% and 0.154 for cyclohexane and n-pentane, respectively.