Thermoeconomic Evaluation of Combined Heat and Power Generation for Geothermal Applications

Florian Heberle
University of Bayreuth, Germany

Markus Preißinger
University of Bayreuth, Germany

Dieter Brüggemann
University of Bayreuth, Germany

Ladda ner artikelhttp://dx.doi.org/10.3384/ecp110571305

Ingår i: World Renewable Energy Congress - Sweden; 8-13 May; 2011; Linköping; Sweden

Linköping Electronic Conference Proceedings 57:10, s. 1305-1312

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Publicerad: 2011-11-03

ISBN: 978-91-7393-070-3

ISSN: 1650-3686 (tryckt), 1650-3740 (online)


In this study a thermoeconomic analysis of combined heat and power generation (CHP) for geothermal applications is presented. Different working fluids and power plant concepts are investigated for power generation by Organic Rankine Cycle and additional heat generation. For geothermal conditions in Germany; process simulations of series; parallel and hybrid circuits compared to sole power generation are performed. The results show that for power generation fluids with low critical temperature; like R227ea or isobutane; are suitable. In general; an additional heat generation decreases the averaged costs of electricity generation. In case of a source temperature of 120 °C the costs can be reduced from 25 ct/kWh to 16 ct/kWh compared to power generation. For CHP applications fluids with higher critical temperature and series or hybrid circuits are the most efficient concepts. With increasing temperature of the geothermal water an increase of supply temperature of the heating system has less influence on the costs of electricity generation. A doubling of mass flow of the geothermal water decreases the averaged costs of electricity generation in the range of 28 % and 43 % depending on power plant concept and boundary conditions.


Geothermal energy; Organic Rankine Cycle; cogeneration; thermoeconomic analysis


[1] R. DiPippo; Small geothermal power plants: design; performance and economics; GHC Bul-letin; June 1999.

[2] B. Saleh; G. Koglbauer; M. Wendland; J. Fischer; Working fluids for low-temperature organ-ic Rankine cycles; Energy 32; 2007; pp. 1210-1221. doi: 10.1016/j.energy.2006.07.001.

[3] U. Drescher; D. Brüggemann; Fluid selection for the Organic Rankine Cycle (ORC) in bio-mass power and heat plants; Applied Thermal Engineering 27; 2007; pp. 223-228. doi: 10.1016/j.applthermaleng.2006.04.024.

[4] S. Karellas; A. Schuster; Supercritical fluid parameters in Organic Rankine Applications; International Journal of Thermodynamics 11; 2008; pp. 101-108.

[5] Z. Gnutek; A. Bryszewska-Mazurek; The thermodynamic analysis of multicycle ORC engine; Energy 26; 2001; pp. 1075-1082. doi: 10.1016/S0360-5442(01)00070-6.

[6] O. Arslan; Exergoeconomic evaluation of electricity generation by the medium temperature geothermal resources; using a Kalina cycle: Simav case study; International Journal of Ther-mal Sciences 49; 2010; pp. 1866-1873. doi: 10.1016/j.ijthermalsci.2010.05.009.

[7] O. Arslan et al.; Exergoeconomic evaluation on the optimum heating circuit system of Simav geothermal district heating system; Energy and Buildings 41; 2009; pp. 1325-1333. doi: 10.1016/j.enbuild.2009.07.029.

[8] A. Hepbasli; A review on energetic; exergetic and exergoeconomic aspects of geothermal district heating systems; Energy Conversion and Management 51; 2010; pp. 2041-2061. doi: 10.1016/j.enconman.2010.02.038.

[9] N. Woudstra; T.P. van der Stelt. Cycle-Tempo: a program for the thermodynamic analysis. Energy Technology Section; Delft University of Technology; The Netherlands; 2002.

[10] E.W. Lemmon; M.L. Huber; M.O. McLinden. NIST Standard Reference Database 23 – Ver-sion 8.0. Physical and Chemical Properties Division; National Institute of Standards and Technology; Boulder; Colorado; US Department of Commerce; USA; 2002.

[11] P. Mago; L. Chamra; K. Srinivasan; C. Somayaji; An examination of regenerative organic Rankine cycles using dry fluids; Applied Thermal Engineering 28; 2008; pp. 998-1007. doi: 10.1016/j.applthermaleng.2007.06.025.

[12] F. Heberle; D. Brüggemann; Exergy based fluid selection for a geothermal Organic Rankine Cycle for combined heat and power generation; Applied Thermal Engineering 30; 2010; pp. 1326-1332. doi: 10.1016/j.applthermaleng.2010.02.012.

[13] B. Görke; A. Sievers; Gewinnbetrachtung von strom- und wärmegeführten Geothermie-Projekten unter Berücksichtigung der aktuellen EEG Novelle; Tagungsband Geothermiekon-gress; 2008; Karlsruhe (D); pp. 157-156.

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