Thermodynamic Analysis of Solar Organic Rankine Cycle Using Evacuated Tubular Collector

Abstract

This study investigates the affecting parameters for the thermal performance of a Solar Organic Rankine Cycle. The thermodynamic analysis covers the research on the effects of the following parameters: the pressure and temperature of the working fluid at the turbine entrance, and the turbine and pump isentropic efficiencies. The solar organic Rankine cycle is analyzed for an evacuated tubular solar collector. The required collector area for both a fixed value (0.8) of solar fraction and several source (solar collector output) temperatures is also determined for different months of the year in the study. The computer software of Engineering Equation Solver (EES) is used to construct the mathematical model of the cycle and to perform the thermodynamic analysis of the system. In the analysis, R123 and R600 organic fluids are used, and a comparison is made between the two fluids in terms of their effects on the system performance. The results show that R600 has better performance characteristics than R123. The results also show that the system efficiency decreases with increasing temperature at turbine entrance, but with decreasing pressure at turbine entrance. The turbine efficiency influences the system thermal efficiency significantly while the pump efficiency does not have a significant effect on the system thermal efficiency.