Research Projects and Publications

Thermoeconomic analysis of geothermal power cycles for IDDP-1 chloride mitigation

Geothermal Engineering and Exploration HS Orka Landsvirkjun Orkuveita Reykjavíkur Show all

Author: Alberto Mereto

Year: 2016

Supervisor: María Sigríður Guðjónsdóttir & Vijay Chauhan

The project was conducted in cooperation with ÍSOR, HS Orka and Landsvirkjun.


This thesis deals with the thermoeconomic analysis of four geothermal power cycles proposed for utilization of superheated steam from IDDP-1. These cycles mainly consider mitigation techniques applied for the removal of the chloride present in the fluid. Through executing a comparative thermoeconomic analysis, this research highlights the importance of the correlation between exergetic efficiency, exergy costing and capital costs. Exergy analysis and cost estimation were performed for each component and for the cycles as a whole. The cycles were proposed in literature and are designed to process efficient chloride-induced corrosion mitigation techniques to be applied to the world's first magma-EGS well, IDDP-1. The work compares four cycles, three of them apply wet scrubbing technique while the fourth is a binary cycle. The base case cycle considered in this study is a single flash cycle where the superheat of the fluid is quenched before the turbine. A cycle with an additional turbine together with a cycle with heat recovery are the two alternative cycles utilizing wet scrubbing. The cycle with heat recovery performs best under every aspect as it is the one with the highest power output and the lowest unit cost of exergy of all cycles. Design and economic limitations of the other cycles also confirm the heat recovery cycle as being the most realistic one. On the contrary, the binary cycle resulted as the most expensive in unit cost of exergy and the base case cycle performed the worst in power output. In total, this work provides an idea of the path to follow in designing a geothermal power plant by accomplishing a component by component thermoeconomic analysis and combining the factors used to obtain the optimal cycle design.

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