Comparative Analysis of Geothermal Powered Organic Rankine Cycle for Supercritical Fluids

Year 2019, Volume: 11 Issue: 3, 155 - 169, 30.12.2019

Önder Kızılkan

Abstract

Turkey's
energy consumption has risen in conjunction with its economic growth over the
past decades. However, approximately 70 % of the electricity demand is supplied
by fossil-based fuels, which are mainly imported from other countries. Thus, it
became very important for the country to find alternative ways of meeting the
energy requirement. Due to its geographical position, the renewable energy
potential of Turkey is fairly well, which is currently contributing to the
energy generation but not at the desired level. One of them is the geothermal
energy that Turkey has many geothermal areas, and they are relatively
appropriate for electricity production. This study aims to investigate the
performance of a geothermal based transcritical Rankine cycle for various
supercritical working fluids. The geothermal reservoir is located in the west
part of Turkey, and the geothermal water temperature is about 156 °C. Using the
actual data, comparative thermodynamic analyses are carried out for determining
the best working fluid. Results show that the highest power generation rate is
calculated for the cycle using R170 with 6125 kW, followed by R744. In
addition, the highest irreversibility is calculated for R125 with an exergy
destruction rate of 8397 kW.

Keywords

Geothermal energy, ORC, supercritical, thermodynamic analysis

Evaluation of Transcritical Rankine Cycle Driven by Low-Temperature Geothermal Source for Different Supercritical Working Fluids

Abstract

Turkey's
energy consumption has risen in conjunction with its economic growth over the
past decades. However, approximately 70 % of the electricity demand is supplied
by fossil-based fuels, which are mainly imported from other countries. Thus, it
became very important for the country to find alternative ways of meeting the
energy requirement. Due to its geographical position, the renewable energy
potential of Turkey is fairly well, which is currently contributing to the
energy generation but not at the desired level. One of them is the geothermal
energy that Turkey has many geothermal areas, and they are relatively
appropriate for electricity production. This study aims to investigate the
performance of a geothermal based transcritical Rankine cycle for various
supercritical working fluids. The geothermal reservoir is located in the west
part of Turkey, and the geothermal water temperature is about 156 °C. Using the
actual data, comparative thermodynamic analyses are carried out for determining
the best working fluid. Results show that the highest power generation rate is
calculated for the cycle using R170 with 6125 kW, followed by R744. In
addition, the highest irreversibility is calculated for R125 with an exergy
destruction rate of 8397 kW.

Keywords

Geothermal energy, Transcritical Rankine cycle, Supercritical fluid, Exergy

References

• ASHRAE (2009). Ashrae Handbook Fundamentals. American Society of Heating, Refrigerating and Air-Conditioning Engineers, 880pp.
• Babatunde A.F., Sunday, O.O. (2018). A Review of Working Fluids for Organic Rankine Cycle (ORC) Applications. IOP Conf. Ser.: Mater. Sci. Eng. 413, 012019.
• Bandean, D.C., Smolen, S., Cieslinski, J.T. (2011). Working fluid selection for Organic Rankine Cycle applied to heat recovery systems. World Renewable Energy Congress, 8-13 May 2011, Linköping Sweeden, 772-779.
• Bejan, A. (1997). Advanced Engineering Thermodynamics. John Wiley and Sons, New York, USA.
• Cengel, Y.A., Boles, M.A. (2006). Thermodynamics: an engineering approach. McGraw-Hill, New York,
• Dincer, I., Rosen, M.A. (2007). Exergy: Energy, Environment and Sustainable Development. Elsevier Science. Heberle, F., Hofer, M., Brüggemann, D. (2017a). A Retrofit for Geothermal Organic Rankine Cycles based on Concentrated Solar Thermal Systems. Energy Procedia. 129, 692-699.
• Heberle, F., Hofer, M., Ürlings, N., Schröder, H., Anderlohr, T., Brüggemann, D. (2017b). Techno-economic analysis of a solar thermal retrofit for an air-cooled geothermal Organic Rankine Cycle power plant. Renewable Energy, 113, 494-502
• Jumel, S., Feidt, M., Le, V.L., Kheiri, A. (2012). Working fluid selection and performance comparison of subcritical and supercritical organic Rankine cycle (ORC) for low temperature waste heat recovery. ECEEE 2012 Summer Study on Energy Efficiency in Industry, 559-569.
• Kajurek, J., Rusowicz, A., Grzebielec, A., Bujalski, W., Futyma, K., Rudowicz, Z. (2019). Selection of refrigerants for a modified organic Rankine cycle. Energy, 168, 1-8.
• Karellas, S., Schuster, A. (2008). Supercritical Fluid Parameters in Organic Rankine Cycle Applications. Int. J. of Thermodynamics, 11(3), 101-108.
• Klein, S.A. (2018). Engineering Equation Solver. (EES). F-Chart.
• Liu, B.T., Chien, K.H., Wang, C.C. (2004). Effect of working fluids on organic Rankine cycle for waste heat recovery. Energy, 29(8), 1207-1217.
• Moloney, F., Almatrafi, E., Goswami, D.Y. (2017). Working fluid parametric analysis for regenerative supercritical organic Rankine cycles for medium geothermal reservoir temperatures. Energy Procedia, 129, 599-606.
• Radulovic, J. (2015). Utilisation Of Fluids With Low Global Warming Potential In Supercritical Organic Rankine Cycle. Journal of Thermal Engineering, 1( 1), 24-30.
• Schuster, A., Karellas, S., Aumann, R. (2010). Efficiency optimization potential in supercritical Organic Rankine Cycles. Energy, 35(2), 1033-1039.
• Sun, J., Liu, Q., Duan, Y. (2018). Effects of evaporator pinch point temperature difference on thermo-economic performance of geothermal organic Rankine cycle systems. Geothermics, 75, 249-258.
• Wang, X., Levy, E.K., Pan, C., Romero, C.E., Banerjee, W., Rubio-Maya, C., Pan, L. (2019). Working fluid selection for organic Rankine cycle power generation using hot produced supercritical CO2 from a geothermal reservoir. Applied Thermal Engineering, 149, 1287-1304.
• Zhang, C., Lin, J., Tan, Y. (2019). A theoretical study on a novel combined organic Rankine cycle and ejector heat pump. Energy, 176, 81-90.