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Causes of Rotor Distortions and Applicable Common Straightening Methods for Turbine Rotors and Shafts

Authors: Esmaeil Poursaeidi, Mostafa Kamalzadeh Yazdi

Abstract:

Different problems may causes distortion of the rotor, and hence vibration, which is the most severe damage of the turbine rotors. In many years different techniques have been developed for the straightening of bent rotors. The method for straightening can be selected according to initial information from preliminary inspections and tests such as nondestructive tests, chemical analysis, run out tests and also a knowledge of the shaft material. This article covers the various causes of excessive bends and then some applicable common straightening methods are reviewed. Finally, hot spotting is opted for a particular bent rotor. A 325 MW steam turbine rotor is modeled and finite element analyses are arranged to investigate this straightening process. Results of experimental data show that performing the exact hot spot straightening process reduced the bending of the rotor significantly.

Keywords: Distortion, FEM, Hot Spot Area, Rotor Straightening

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1058534

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References:


[1] "Bowed rotor straightening," Mechanical Dynamic & Analysis, LTD., Private communication, 2011.
[2] G. T. Jones, and J. Gunning, "Causes for and Methods of Straightening Bent Turbine Rotors," ERA Technology, U.K., private communication, 1988.
[3] H. P. Bloch, and F. K. Geitner, "Machinery Component Maintenance and Repair," Gulf Publishing Co, 3rd ed, Elsevier, pp. 476-479, 1999.
[4] H. A. Erb, "Repair Techniques for Machinery Rotor and Case Damage," Elliott Co., Greensburg, Pennsylvania, January 1975.
[5] H. L. Harrison, "Straightening Structural Members in Place," Welding Journal, Vol. 31, pp. 2575-2625, May 1952.
[6] E. poursaeidi, A. R. Razavi, "An investigation on the causes of rotor bending and its thermal straightening," IJE Trans. Vol. 21, No. 3, pp. 281-290. 2008.
[7] B.J. Cane, "What limits the Life of Power Plant?," Power Plant UK 89 Birmingham 1989.
[8] J. Morris, "Controlled Distortion-an aid to Metal Working," Welding Journal, pp. 1080-1082, November 1949.
[9] Defense Standard 02-304 part 4, "Requirements for repair of main propulsion shafting," Vol. 12, September 2002.
[10] B. E. Gatewood, "Thermal stresses with applications to airplanes, missiles, turbines and nuclear reactors," McGraw-Hill, New York, U.S.A., 1957.
[11] R. l. Rothman, "Flame straightening quenched and tempered steels in ship construction," Ship Structures Committee, Battelle Columbus Labs Ohio, U.S.A., Report No. 335, 1974.
[12] R. Avent, R. Mukai, D. J. Robinson, "Effect of Heat Straightening on Material Properties of Steel," Journal of Materials in Civil Engineering, ASME, Vol. 12, No. 3, pp.188-195, 2000.
[13] G.T. Jones, P. Doig, and D. Lonsdale , "Integrity assessment of two HP turbine rotors straightened by hotspotting," The second parsons turbine conference Cambridge UK, 1988.