The technology of restoration hydrogenerator rotor shape

Pavlo Makarov

Abstract


The object of research in this article is the change in the rotor shape during the operation of hydraulic units. The subject of study in this article is the design and geometric state of the shape of a rotor with irregular geometry of hydraulic generators-engines. This study produced a three-dimensional mechanical calculation of the rotor segment for further use during strain gauge tests. Tasks: investigate the peculiarities of the rotor shape restoration technology; to describe the basic assumptions for the three-dimensional mechanical calculation of rotor deformations at the overspeed; and perform a three-dimensional calculation of rotor movements considering the main forces falling on the pole connection, which are obtained using classical methods. The methods used are: finite element method of mathematical modeling of the thermal stress state of nodes. The following results were obtained: a detailed description of the technological process of restoring the shape of the rotor using the hot wedging method is given. Three-dimensional models of the rotor segment were developed, and a three-dimensional mechanical calculation of this model was performed, as a result of which satisfactory values of the displacement of the rotor of the hydraulic generator at the overspeed were obtained, considering the recovery technology. To reconstruct the rotor rim, it is necessary to heat the rotor rim to a temperature difference between the rim and the frame of at least 60 °C. Next, the hot wedging of the rotor rim is performed with the driving of each of the driving wedges by the same amount, which ensures the creation of the necessary diametrical tension between the rim and the frame of the rotor and avoids the displacement of the rotor rim relative to the frame. The control of this process is performed using strain gauges. If necessary, it is necessary to cool the rotor rim until the temperatures of the rim and the frame of the rotor are equal. Conclusions. The scientific novelty consists of a combined approach to the evaluation of the deformation of the rotor rim after restoring its shape, which includes elements of analytical mechanical calculation and calculation in a three-dimensional setting. The presented technology for the rotor restoration process meets European requirements.

Keywords


hydrogenerator; rotor; air gap; wedging of poles; strength calculation

References


Landau, Yu. A. Analyz sostojanyja y perespektyvi yspolzovanyja hydroenerhetyčeskyx resursov pry razvytyy obiedynennoj enerhosystemy (OES) Ukrayni [Analysis of the state and prospects for the use of hydropower resources in the development of the unified energy system (UES) of Ukraine]. Hydropower of Ukraine. Series: Science. Scientific and technical progress in hydropower. 2020, ISSN 1812-9277, pp. 16–21.

Bazeev, E. T., Bileka, B. D., Vasiliev, E. P., Varlamov, G. B. & Volchyn, I. A. Energetyka: istoriya, suchasnist i majbutnye. Kn. 3: Rozvytok teploenergetyky ta gidroenergetyky [Energy: history, modernity and future. Book 3: Development of heat and hydropower]. Kyiv, 2013. 399 p. ISBN 978-966-8163-15-9.

Alekseev, B. A. Opredeleniye sostoyaniya (diagnostika) krupnykh gidrogeneratorov [Determination of the state (diagnostics) of large hydro generators]. Moscow, Scientific and educational center ENAS, 1998. 144 p.

Kuzmin, V. V. & Vakulenko A. N. Rezhimy ekspluatatsii i naiboleye chasto vstrechayushchiyesya povrezhdeniya gidrogeneratorov GES Dneprovskogo kaskada. Vliyaniye parametrov vozdushnogo zazora mezhdu rotorom i statorom gidrogeneratora na na-dezhnost' yego raboty [Operating modes and the most common damage to hydroelectric generators of the Dnieper cascade HPP. Influence of the air gap parameters between the rotor and the stator of the hydroelectric generator on the reliability of its operation]. Hydropower of Ukraine, 2005, no. 2, pp. 22-30.

Li, J., Chen, D., Liu, G., Gao, X., Miao, K., Li, Y. & Xu, B. Analysis of the gyroscopic effect on the hydro-turbine generator unit. Mechanical Systems and Signal Processing, 2019, vol. 132, pp. 138-152. DOI: 10.1016/j.ymssp.2019.06.020.

Valavi, M., Nysveen, A., Nilsen, R., Le, B. J. & Devillers E. Analysis of magnetic forces and vibration in a converter-fed synchronous hydrogenator. 2017 IEEE Energy Conversion Congress and Exposition (ECCE), Cincinnati, OH, USA, 2017, pp. 1838-1844. DOI: 10.1109/ECCE.2017.8096018.

DSTU EN IEC 60034-33:2022 Electric rotating machines. Part 33. Synchronous hydrogen generators, including motor generators. Special requirements. Internstional Standart (2022). Available at: http://online.budstandart.com/ru/catalog/doc-page.html?id_doc=102789 (accessed 22/03/2023).

Timoshenko, S. P. Soprotivleniye materialov [Resistance of materials. In 2 volumes]. Moscow, Nauka Publ., 1965. Vol. 1. Elementary theory and problems. 364 p.

Tretiak, O., Kritskiy, D., Kobzar, I., Arefieva, M. & Nazarenko, V. The Methods of Three-Dimensional Modeling of the Hydrogenerator Thrust Bearing. Computation, 2022, vol. 10, iss. 9, article no. 152. DOI: 10.3390/computation10090152.




DOI: https://doi.org/10.32620/aktt.2023.4sup2.13