MACHINES

Thermodynamic analysis of backpressure and condensing steam turbines from cogeneration system

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

Abstract

This paper presents thermodynamic (energy and exergy) analysis of backpressure (BPT) and condensing (CT) steam turbines from cogeneration system. Based on the measurement data from exploitation it is performed calculation of main operating parameters for both turbines and its comparison. Analysis shows that BPT develops significantly lower mechanical power (22821.90 kW) in comparison to CT (30893.10 kW), but also BPT has more than four times lower energy and exergy power losses when compared to CT. Due to much lower losses, BPT has significantly higher energy and exergy efficiencies (93.26% and 94.95%, respectively) in comparison to CT (82.63% and 83.87%, respectively). Energy and exergy power of a steam flow related to both observed turbines show that the BPT is the dominant heat supplier for all heat consumers inside the cogeneration system.

Keywords

References

  1. ] Ahmadi, G. R., Toghraie, D.: Energy and exergy analysis of Montazeri steam power plant in Iran, Renewable and Sustainable Energy Reviews 56, p. 454–463, 2016. (doi:10.1016/j.rser.2015.11.074)
  2. Erdem, H.H., Akkaya, A.V., Cetin, B., Dagdas, A., Sevilgen, S.H., Sahin, B., Teke, I., Gungor, C., Atas, S.: Comparative energetic and exergetic performance analyses for coal-fired thermal power plants in Turkey, International Journal of Thermal Sciences 48, p. 2179–2186, 2009. (doi:10.1016/j.ijthermalsci.2009.03.007)
  3. Mrzljak, V., Poljak, I.: Energy analysis of main propulsion steam turbine from conventional LNG carrier at three different loads, International Journal of Maritime Science & Technology “Our Sea” 66 (1), p. 10-18, 2019. (doi:10.17818/NM/2019/1.2)
  4. Koroglu, T., Sogut, O. S.: Conventional and advanced exergy analyses of a marine steam power plant, Energy 163, p. 392-403, 2018. (doi:10.1016/j.energy.2018.08.119)
  5. Mrzljak, V., Poljak, I., Prpić-Oršić, J.: Exergy analysis of the main propulsion steam turbine from marine propulsion plant, Shipbuilding 70 (1), p. 59-77, 2019. (doi:10.21278/brod70105)
  6. Ersayin, E., Ozgener, L.: Performance analysis of combined cycle power plants: A case study, Renewable and Sustainable Energy Reviews 43, p. 832–842, 2015. (doi:10.1016/j.rser.2014.11.082)
  7. Lorencin, I., Anđelić, N., Mrzljak, V., Car, Z.: Genetic algorithm approach to design of multi-layer perceptron for combined cycle power plant electrical power output estimation, Energies 12 (22), 4352, 2019. (doi:10.3390/en12224352)
  8. Burin, E. K., Vogel, T., Multhaupt, S., Thelen, A., Oeljeklaus, G., Gorner, K., Bazzo, E.: Thermodynamic and economic evaluation of a solar aided sugarcane bagasse cogeneration power plant, Energy 117, Part 2, p. 416-428, 2016. (doi:10.1016/j.energy.2016.06.071)
  9. Behrendt, C., Stoyanov, R.: Operational characteristic of selected marine turbounits powered by steam from auxiliary oil-fired boilers, New Trends in Production Engineering 1 (1), p. 495-501, 2018. (doi:10.2478/ntpe-2018- 0061)
  10. Mrzljak, V., Senčić, T., Ţarković, B.: Turbogenerator steam turbine variation in developed power: analysis of exergy efficiency and exergy destruction change, Modelling and Simulation in Engineering 2945325, 2018. (doi:10.1155/2018/2945325)
  11. Adibhatla, S., Kaushik, S. C.: Energy and exergy analysis of a super critical thermal power plant at various load conditions under constant and pure sliding pressure operation, Applied Thermal Eng. 73, p. 49-63, 2014. (doi:10.1016/j.applthermaleng.2014.07.030)
  12. Mrzljak, V., Prpić-Oršić, J., Poljak, I.: Energy power losses and efficiency of low power steam turbine for the main feed water pump drive in the marine steam propulsion system, Journal of Maritime & Transportation Sciences 54 (1), p. 37-51, 2018. (doi:10.18048/2018.54.03)
  13. Mrzljak, V., Poljak, I., Mrakovčić, T.: Energy and exergy analysis of the turbo-generators and steam turbine for the main feed water pump drive on LNG carrier, Energy Conv. and Management 140, p. 307–323, 2017. (doi:10.1016/j.enconman.2017.03.007)
  14. Kostyuk, A., Frolov, V.: Steam and gas turbines, Mir Publishers, Moscow, 1988.
  15. Woodruff, E., Lammers, H., Lammers, T.: Steam Plant Operation, 8th edition, McGraw-Hill Professional, New York, USA, 2004.
  16. Aljundi, I.H.: Energy and exergy analysis of a steam power plant in Jordan, Applied thermal engineering, 29 (2-3), p.324-328, 2009. (doi:10.1016/j.applthermaleng.2008.02.029)
  17. Mrzljak, V., Poljak, I., Medica-Viola, V.: Dual fuel consumption and efficiency of marine steam generators for the propulsion of LNG carrier, Applied Thermal Engineering 119, p. 331–346, 2017. (doi:10.1016/j.applthermaleng.2017.03.078)
  18. Škopac, L., Medica-Viola, V., Mrzljak, V.: Selection Maps of Explicit Colebrook Approximations according to Calculation Time and Precision, Heat Transfer Engineering 42 (10), p. 839-853, 2021. (doi:10.1080/01457632.2020.1744248)
  19. Nandini, M., Sekhar, Y. R., Subramanyam, G.: Energy analysis and water conservation measures by water audit at thermal power stations, Sustainable Water Resources Management 7 (1), p. 1-24, 2021. (doi:10.1007/s40899-020-00487-4)
  20. Medica-Viola, V., Baressi Šegota, S., Mrzljak, V., Štifanić, D.: Comparison of conventional and heat balance based energy analyses of steam turbine, Scientific Journal of Maritime Research 34 (1), p.74-85, 2020. (doi:10.31217/p.34.1.9)
  21. Mrzljak, V., Prpić-Oršić, J., Senčić, T.: Change in steam generators main and auxiliary energy flow streams during the load increase of LNG carrier steam propulsion system, Scientific Journal of Maritime Research 32 (1), p. 121-131, 2018. (doi:10.31217/p.32.1.15)
  22. Mrzljak, V., Anđelić, N., Poljak, I., Orović, J., Thermodynamic analysis of marine steam power plant pressure reduction valves, Journal of Maritime & Transportation Sciences 56 (1), p. 9-30, 2019. (doi:10.18048/2019.56.01)
  23. Mrzljak, V., Poljak, I., Prpić-Oršić, J., Jelić, M.: Exergy analysis of marine waste heat recovery CO2 closed-cycle gas turbine system, Scientific Journal of Maritime Research 34 (2), p. 309-322, 2020. (doi:10.31217/p.34.2.12)
  24. Uysal, C., Kurt, H., Kwak H.-Y.: Exergetic and thermoeconomic analyses of a coal-fired power plant, International Journal of Thermal Sciences 117, p. 106-120, 2017. (doi:10.1016/j.ijthermalsci.2017.03.010)
  25. Naserbegi, A., Aghaie, M., Minuchehr, A., Alahyarizadeh, Gh.: A novel exergy optimization of Bushehr nuclear power plant by gravitational search algorithm (GSA), Energy 148, p. 373-385, 2018. (doi:10.1016/j.energy.2018.01.119)
  26. Mrzljak, V., Anđelić, N., Lorencin, I., Baressi Šegota, S.: The influence of various optimization algorithms on nuclear power plant steam turbine exergy efficiency and destruction, Scientific Journal of Maritime Research 35 (1), p. 69-86, 2021. (doi:10.31217/p.35.1.8)
  27. Kowalczyk, T., Ziółkowski, P., Badur, J.: Exergy losses in the Szewalski binary vapor cycle, Entropy 17, p. 7242-7265, 2015. (doi:10.3390/e17107242)
  28. Elhelw, M., Al Dahma, K. S., Hamid Attia, A. E.: Utilizing exergy analysis in studying the performance of steam power plant at two different operation mode, Applied Thermal Engineering 150, p. 285–293, 2019. (doi:10.1016/j.applthermaleng.2019.01.003)
  29. Tan, H., Shan, S., Nie, Y., Zhao, Q.: A new boil-off gas re-liquefaction system for LNG carriers based on dual mixed refrigerant cycle, Cryogenics 92, p. 84–92, 2018. (doi:10.1016/j.cryogenics.2018.04.009)
  30. Kamate, S. C., Gangavati, P. B.: Energy and exergy analysis of a 44- MW bagasse-based cogeneration plant in India, Cogeneration and Distributed Generation Journal 25 (1), p. 35-51, 2010. (doi:10.1080/15453661009709861)
  31. Lemmon, E.W., Huber, M.L., McLinden, M.O.: NIST reference fluid thermodynamic and transport properties-REFPROP, version 9.0, User’s guide, Colorado, 2010.

Article full text

Download PDF