Energy analysis of main and auxiliary steam turbine from coal fired power plant

  • 1 Faculty of Engineering, University of Rijeka, Croatia
  • 2 Department of maritime sciences, University of Zadar, Croatia


This paper presents an energy analysis of main and auxiliary steam turbines from conventional coal fired power plant. Main turbine is composed of three cylinders connected to the same shaft which drives an electric generator, while auxiliary steam turbine is used for the boiler feedwater pump drive. The whole analyzed main steam turbine produces mechanical power equal to 312.34 MW, while in an ideal situation, it can produce mechanical power equal to 347.28 MW. The highest part of the mechanical power in the main turbine is produced in the low pressure cylinder. Auxiliary steam turbine in exploitation develops mechanical power equal to 6768.94 kW, while in an ideal situation it can develop 8029.03 kW. Whole main turbine energy efficiency is equal to almost 90% what is in the expected range for such high power turbines. The auxiliary steam turbine has an energy efficiency equal to 84.31%, which is almost 6% lower in comparison to the main turbine. Energy flows delivered to the last two feedwater heaters (HPH2 and HPH3) in the condensate/feedwater heating system are notably higher in comparison to energy flows delivered to any other condensate/feedwater heater.



  1. Erdem, H. H., Akkaya, A. V., Cetin, B., Dagdas, A., Sevilgen, S. H., Sahin, B., ... & Atas, S. (2009). Comparative energetic and exergetic performance analyses for coal-fired thermal power plants in Turkey. International Journal of Thermal Sciences, 48(11), 2179-2186. (doi:10.1016/j.ijthermalsci.2009.03.007)
  2. Elhelw, M., & Al Dahma, K. S. (2019). Utilizing exergy analysis in studying the performance of steam power plant at two different operation mode. Applied Thermal Engineering, 150, 285-293. (doi:10.1016/j.applthermaleng.2019.01.003)
  3. Mitrović, D., Zivkovic, D., & Laković, M. S. (2010). Energy and exergy analysis of a 348.5 MW steam power plant. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 32(11), 1016- 1027. (doi:10.1080/15567030903097012)
  4. Elčić, Z. (1995). Steam turbines. ABB, Karlovac, National and University Library Zagreb.
  5. Mrzljak, V., Lorencin, I., Anđelić, N., & Car, Z. (2021). Thermodynamic Analysis of a Condensate Heating System from a Marine Steam Propulsion Plant with Steam Reheating. Journal of Marine Science and Application, 20(1), 117-127. (doi:10.1007/s11804-021-00191-5)
  6. Ahmadi, G. R., & Toghraie, D. (2016). Energy and exergy analysis of Montazeri steam power plant in Iran. Renewable and Sustainable Energy Reviews, 56, 454-463. (doi:10.1016/j.rser.2015.11.074)
  7. Adibhatla, S., & Kaushik, S. C. (2014). Energy and exergy analysis of a super critical thermal power plant at various load conditions under constant and pure sliding pressure operation. Applied thermal engineering, 73(1), 51-65. (doi:10.1016/j.applthermaleng.2014.07.030)
  8. Mrzljak, V., Senčić, T., Poljak, I., & Medica-Viola, V. (2022). Thermodynamic Analysis of Steam Cooling Process in Marine Power Plant by Using Desuperheater. Pomorski zbornik, 62(1), 9-30.
  9. Mrzljak, V., Prpić-Oršić, J., & Poljak, I. (2018). Energy power losses and efficiency of low power steam turbine for the main feed water pump drive in the marine steam propulsion system. Pomorski zbornik, 54(1), 37-51. (doi:10.18048/2018.54.03)
  10. Mrzljak, V., Poljak, I., & Mrakovčić, T. (2017). Energy and exergy analysis of the turbo-generators and steam turbine for the main feed water pump drive on LNG carrier. Energy conversion and management, 140, 307-323. (doi:10.1016/j.enconman.2017.03.007)
  11. Mrzljak, V., Kudláček, J., Baressi Šegota, S., & Medica-Viola, V. (2021). Energy and Exergy Analysis of Waste Heat Recovery Closed- Cycle Gas Turbine System while Operating with Different Medium. Pomorski zbornik, 60(1), 21-48. (doi:10.18048/2021.60.02)
  12. Mrzljak, V., Poljak, I., & Medica-Viola, V. (2017). Energy and exergy efficiency analysis of sealing steam condenser in propulsion system of LNG carrier. NAŠE MORE: znanstveni časopis za more i pomorstvo, 64(1), 20-25. (doi:10.17818/NM/2017/1.4)
  13. Medica-Viola, V., Baressi Šegota, S., Mrzljak, V., & Štifanić, D. (2020). Comparison of conventional and heat balance based energy analyses of steam turbine. Pomorstvo, 34(1), 74-85. (doi:10.31217/p.34.1.9)
  14. Mrzljak, V., Poljak, I., & Medica-Viola, V. (2017). Dual fuel consumption and efficiency of marine steam generators for the propulsion of LNG carrier. Applied Thermal Engineering, 119, 331- 346. (doi:10.1016/j.applthermaleng.2017.03.078)
  15. Aljundi, I. H. (2009). Energy and exergy analysis of a steam power plant in Jordan. Applied thermal engineering, 29(2-3), 324-328. (doi:10.1016/j.applthermaleng.2008.02.029)
  16. Zhang, C., Wang, Y., Zheng, C., & Lou, X. (2006). Exergy cost analysis of a coal fired power plant based on structural theory of thermoeconomics. Energy Conversion and Management, 47(7-8), 817- 843. (doi:10.1016/j.enconman.2005.06.014)
  17. Lemmon, E. W., Huber, M. L., & McLinden, M. O. (2010). NIST Standard Reference Database 23, Reference Fluid Thermodynamic and Transport Properties (REFPROP), version 9.0, National Institute of Standards and Technology. R1234yf. fld file dated December, 22, 2010.
  18. Mrzljak, V., Senčić, T., & Ţarković, B. (2018). Turbogenerator steam turbine variation in developed power: Analysis of exergy efficiency and exergy destruction change. Modelling and Simulation in Engineering, 2018. (doi:10.1155/2018/2945325)
  19. Mrzljak, V. (2018). Low power steam turbine energy efficiency and losses during the developed power variation. Tehnički glasnik, 12(3), 174-180. (doi:10.31803/tg-20180201002943)
  20. Lorencin, I., Anđelić, N., Mrzljak, V., & Car, Z. (2019). Genetic algorithm approach to design of multi-layer perceptron for combined cycle power plant electrical power output estimation. Energies, 12(22), 4352. (doi:10.3390/en12224352)
  21. Anđelić, N., Baressi Šegota, S., Lorencin, I., Poljak, I., Mrzljak, V., & Car, Z. (2021). Use of Genetic Programming for the Estimation of CODLAG Propulsion System Parameters. Journal of Marine Science and Engineering, 9(6), 612. (doi:10.3390/jmse9060612)

Article full text

Download PDF