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 gas, many studies have been done on the binary-cycle geothermal power plant to obtain the better performance. The radial turbo expander plays an important role in the performance of Organic Rankine Cycle (ORC) for binary-cycle geothermal plants. However, few studies have investigated the effect of parameters of radial turbo expander on the performance of ORC. In this paper, a new thermodynamic model of 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 more reasonable efficiency of radial turbo expanders by using the preliminary design is adapted to analysis the performance of ORC, and more accuracy reference about the effect of geothermal source on the parameters of radial turbo expanders is obtained.