Performance Analysis of Organic Rankine Cycle With Preliminary Design of Radial Turbo Expander for Binary-Cycle Geothermal Plants

In order to produce less emission of greenhouse gases, many studies have been done on the binary-cycle geothermal power plant to obtain better performance. The radial turbo expanders play an important role in the performance of the organic rankine cycle (ORC) for binary-cycle geothermal plants. However, few studies have investigated the effect of parameters of radial turbo expanders on the performance of the ORC. In this paper, a new thermodynamic model of the ORC coupled with the preliminary design of radial turbo expanders is developed. The effects of geothermal water temperature on the ORC performance parameters, such as power output and thermal efficiency are investigated by using the proposed thermodynamic model. The variation of radial turbo expanders’ parameters, such as specific rotational speed with geothermal water temperature is revealed. In the present study, the reasonable efficiency of radial turbo expanders by using the preliminary design is adopted to analyze the performance of the ORC, and an accurate reference about the effect of geothermal source on the parameters of radial turbo expanders is obtained.