Exergoeconomic optimization of an Organic Rankine Cycle for low-temperature geothermal heat sources

Year 2012, Volume: 15 Issue: 2 , 119 - 126 , 17.05.2012

Florian Heberle , Pascal Bassermann Markus Preißinger Dieter Brüggemann

https://izlik.org/JA54JX65YM

Abstract

An exergoeconomic analysis of a geothermal power generation for a low-temperature resource is performed. An Organic Rankine Cycle (ORC) with isobutane and isopentane as working fluids is considered as binary power plant. A systematic parameter variation is done for the minimum temperature difference in the evaporator and condenser. The most suitable design parameters are evaluated under exergetic, economic and exergoeconomic criteria. The specific costs of electricity generation are minimal for the use of isobutane as working fluid and minimal temperature difference of 3 K at evaporation and 7 K at condensation. The most suitable concept for isopentane leads to only 0.4 % higher specific costs although the second law efficiency is 4.75 % lower. The exergoeconomic analysis permits to consider important criteria, like design and operating parameters in the fluid selection for ORC applications.

Keywords

Organic Rankine Cycle; geothermal heat source; exergoeconomic analysis