Multiple flashing in geothermal power plants

Geothermal-based flash steam power plants are promising systems for clean power generation. A comprehensive thermodynamic analysis through energy and exergy approaches is presented here to investigate the optimum flashing pressures for multistep plants, including single-, double-, triple-, and quadruple-flash systems with reinjection. A new methodology is presented to investigate the optimum pressure levels for the flashing process, which can be considered as a suitable range of operation in power-generating geothermal plants. The present methodology is combined with a family of curves representing power output vs flashing pressure to determine the maximum available power for the system. The performances of the proposed systems are evaluated from both energy and exergy perspectives. It is shown that an energy efficiency analysis alone is insufficient to differentiate between the systems. The results of the exergy approach indicate a significant improvement in terms of efficiency as the quantity of flashing steps has risen. The potential performance enhancement in terms of power output becomes smaller as the quantity of flashing steps becomes four or more