|Journal||Journal of Mechanical Engineering|
|Publisher||A. Podgorny Institute for Mechanical Engineering Problems
National Academy of Science of Ukraine
|ISSN||0131-2928 (Print), 2411-0779 (Online)|
|Issue||Vol. 23, no. 3, 2020 (September)|
|Cited by||J. of Mech. Eng., 2020, vol. 23, no. 3, pp. 8-15|
Olha Yu. Chernousenko, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” (37, Peremohy Ave., Kyiv, 03056, Ukraine), e-mail: email@example.com, ORCID: 0000-0002-1427-8068
Vitalii A. Peshko, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” (37, Peremohy Ave., Kyiv, 03056, Ukraine), e-mail: firstname.lastname@example.org, ORCID: 0000-0003-0610-1403
200 MW steam turbines of DTEK Lugansk TPP units have operated for about 305–330 thousand hours with a total number of starts from 1.438 to 1,704, as of the end of 2019. The term for extending the operation of high-temperature power equipment between scheduled preventive maintenances has expired. When extending the operation of cylinder bodies and rotors, one should also pay attention to steam distribution elements. A peculiarity of the re-extension of the operation of a 200 MW power unit is the beyond-design operating time of power equipment of more than 250 thousand hours and the operation of equipment in maneuverable modes (more than 1,700 starts from various thermal states), with covering peaks of the electrical load with the excess of the number of starts for certain types of equipment by two to three times. Such a significant number of variable operating modes negatively affects the life cycle of equipment and requires studying the influence of the main damage mechanisms on the metal of cast components. The paper presents a calculated study of the thermal and stress-strain states of high- pressure (HP) and intermediate-pressure (IP) control valves of a K-200-130 turbine. The calculations were carried out using three-dimensional geometric models, as well as taking into account real operating conditions. The geometric model of HP control-valve bodies was constructed taking into account the complex geometry during the transition from the inlet nozzles to the valve vapor volume with a subsequent narrowing of the outlet nozzle section to the control stage of the HP cylinder. Similarly, the geometric model of IP control-valve bodies was constructed taking into account the complex spatial geometry according to the drawings provided by the operating organization. A numerical study of the thermal and stress-strain states was carried out for typical operating modes, using the finite element method. Start-up modes were investigated in a non-stationary setting, while constant ones – in a stationary setting. The thermal states of HP and IP control valves were calculated for three variants of startup modes: cold-startup mode at an initial metal temperature of 100 °C, warm-startup mode at an initial metal temperature of 250 °C, and hot-startup mode at an initial metal temperature of 410 °C. The boundary conditions for thermal state calculations were determined using real and most representative startup schedules provided by the power plant. When calculating thermal states for different startup modes, the dynamics of changes in temperature gradients was taken into consideration. During the stress-strain state studies, the main zones of stress concentration in control valves of a K-200-130 steam turbine were established.
Keywords: control valve, K-200-130 steam turbine, thermal state, temperature gradients, stress-strain state.
Full text: Download in PDF
- Sukhinin, V. P., Kanyuk, G. I., & Pugacheva, T. N. (2011). Analiz prichin ischerpaniya resursa parovoy turbiny [Analysis of the causes of exhaustion of the steam turbine resource]. Vestnik NTU «KHPI». Seriya: Energeticheskiye i teplotekhnicheskiye protsessy i oborudovaniye – NTU “KhPI” Bulletin: Power and heat engineering processes and equipment, no. 5, pp. 71–75 (in Russian).
- Dobrovolskyi, V. Ye., Novychenok, L. M., Zavodnyi, M. A., Mukhopad, H. V., Pasternak, V. P., Horieshnik, A. D., & Veksler, Ye. Ya. (2005). Kontrol metalu i prodovzhennia terminu ekspluatatsii osnovnykh elementiv kotliv, turbin i truboprovodiv teplovykh elektrostantsii [Metal control and extension of service life of the main elements of boilers, turbines and pipelines of thermal power plants]. Regulatory document of the Ministry of Fuel and Energy of Ukraine. Typical instruction SOU-N MPE 40.17.401:2004. Kyiv: HRIFRE, Ministry of Fuel and Energy of Ukraine, 76 p. (in Ukrainian).
- Shulzhenko, M. H., Hontarovskyi, P. P., Matiukhin, Yu. I., Melezhyk, I. I., & Pozhydaiev, O. V. (2011). Vyznachennia rozrakhunkovoho resursu ta otsinka zhyvuchosti rotoriv i korpusnykh detalei turbin. [Determination of estimated resource and evaluation of rotor life and body parts of turbines: Methodological guidelines. Regulatory document SOU-N MEV 0.1–21677681–52:2011: approved by the Ministry of Energy and Coal Mining of Ukraine: effective as of 07.07.11. Kyiv: Ministry of Energy and Coal Mining of Ukraine (in Ukrainian).
- Georgiyevskaya, Ye. V. & Gavrilov, S. N. (2013). Osobennosti prodleniya sroka sluzhby parovykh turbin pri narabotkakh, znachitelno prevyshayushchikh parkovyy resurs [Features of prolongation of the service life of steam turbines with operating time significantly exceeding beyond-design life]. Vestnik NTU «KHPI». Seriya: Energeticheskiye i teplotekhnicheskiye protsessy i oborudovaniye – NTU “KhPI” Bulletin: Power and heat engineering processes and equipment, no. 12 (986), pp. 107–113 (in Russian).
- Stoppato, A., Mirandola, A., Meneghetti, G., & Lo Casto, E. (2012). On the operation strategy of steam power plants working at variable load: Technical and economic issues. Energy, vol. 37, iss. 1, pp. 228–236. https://doi.org/10.1016/j.energy.2011.11.042.
- Mirandola, A., Stoppato, A., & Lo Casto, E. (2010). Evaluation of the effects of the operation strategy of a steam power plant on the residual life of its devices. Energy, vol. 35, iss. 2, pp. 1024–1032. https://doi.org/10.1016/j.energy.2009.06.024.
- Kolyadyuk, A. S. & Shulzhenko, N. G. (2014). Otsenka polzuchesti korpusa reguliruyushchego klapana parovoy turbiny K-325 [Assessment of creep of the control valve body of the K-325 steam turbine]. Vestnik NTU «KHPI». Seriya: Energeticheskiye i teplotekhnicheskiye protsessy i oborudovaniye – NTU “KhPI” Bulletin: Power and heat engineering processes and equipment, no. 11 (1054), pp. 125–131 (in Russian).
- Chernousenko, O., Rindyuk, D., & Peshko, V. (2017). Research on residual service life of automatic locking valve of turbine K-200-130. Eastern-European Journal of Enterprise Technologies, vol. 5, no. 8 (89), pp. 39–44. https://doi.org/10.15587/1729-4061.2017.112284.
- Chernousenko, O. Yu., Ryndyuk, D. V., & Peshko, V. A. (2019). Re-extension of 200 MW turbine cast casing service. Journal of Mechanical Engineering, vol. 22, no. 2, pp. 14–20. https://doi.org/10.15407/pmach2019.02.014.
- Chernousenko, O. & Peshko, V. (2017). Computation investigation of the thermal and stress-strain behavior of the rotor of high pressure turbine Т-100/120-130; block No. 1 operated by the PJSC Kharkiv CHPP-5. Bulletin of NTU “KhPI”. Ser. Power and heat engineering processes and equipment, no. 9 (1231), pp. 34–40. https://doi.org/10.20998/2078-774X.2017.09.059.
Received 21 February 2020
Published 30 September 2020