1、BS ISO22266-1:2009ICS 17.160; 29.160.40NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDMechanical vibration Torsional vibrationof rotating machineryPart 1: Land-based steam and gasturbine generator sets in excess of 50MWThis British Standardwas published under t
2、heauthority of the StandardsPolicy and StrategyCommittee on 31 July 2009 BSI 2009ISBN 978 0 580 62434 6Amendments/corrigenda issued since publicationDate CommentsBS ISO 22266-1:2009National forewordThis British Standard is the UK implementation of ISO 22266-1:2009.The UK participation in its prepara
3、tion was entrusted to TechnicalCommittee GME/21/5, Vibration of machines.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct appl
4、ication.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS ISO 22266-1:2009Reference numberISO 22266-1:2009(E)ISO 2009INTERNATIONAL STANDARD ISO22266-1First edition2009-05-01Mechanical vibration Torsional vibration of rotating machinery Part 1: Land-based steam and ga
5、s turbine generator sets in excess of 50 MW Vibrations mcaniques Vibration de torsion des machines tournantes Partie 1: Groupes lectrognes turbines vapeur et gaz situs sur terre et excdant 50 MW BS ISO 22266-1:2009ISO 22266-1:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In ac
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8、inting. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2009 All rights reserved. Unless otherw
9、ise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright
10、office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedBS ISO 22266-1:2009ISO 22266-1:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv Introduction v 1 Scop
11、e . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Fundamentals of torsional vibration. 7 4.1 General. 7 4.2 Influence of blades . 8 4.3 Influence of generator rotor windings 9 5 Evaluation 9 5.1 General. 9 5.2 Frequency margins. 9 5.3 Dynamic stress assessments 12 6 Calculation of torsio
12、nal vibration 12 6.1 General. 12 6.2 Calculation data 13 6.3 Calculation results 13 6.4 Calculation report . 13 7 Measurement of torsional vibration 13 7.1 General. 13 7.2 Method of measurement 13 7.3 Measurement test report 14 8 General requirements. 14 8.1 Set supplier responsibilities 14 8.2 Guar
13、antees 14 8.3 Responsibilities 14 Annex A (informative) Torsional vibration measurement techniques 15 Annex B (informative) Examples of frequency margins relative to line and twice line frequencies for shaft system modes that can be excited by torsional oscillations of the shaft. 21 Annex C (informa
14、tive) Commonly experienced electrical faults . 23 Bibliography . 25 BS ISO 22266-1:2009ISO 22266-1:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparin
15、g International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liai
16、son with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of t
17、echnical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is d
18、rawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 22266-1 was prepared by Technical Committee ISO/TC 108, Mechanical vibration, shock and condition monitoring, S
19、ubcommittee SC 2, Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures. ISO 22266 consists of the following parts, under the general title Mechanical vibration Torsional vibration of rotating machinery: Part 1: Land-based steam and gas turbine
20、generator sets in excess of 50 MW BS ISO 22266-1:2009ISO 22266-1:2009(E) ISO 2009 All rights reserved vIntroduction During the 1970s, a number of major incidents occurred in power plants that were deemed to be caused by or that were attributed to torsional vibration. In those incidents, generator ro
21、tors and some of the long turbine blades of the low-pressure (LP) rotors were damaged. In general, they were due to modes of the coupled shaft and blade system that were resonant with the grid excitation frequencies. Detailed investigations were carried out and it became apparent that the mathematic
22、al models used at that time to predict the torsional natural frequencies were not adequate. In particular, they did not take into account with sufficient accuracy the coupling between long turbine blades and the shaft line. Therefore, advanced research work was carried out to analyse the blade-to-di
23、scs-to-shaft coupling effects more accurately, and branch models were developed to account properly for these effects in shaft system frequency calculations. In the 1980s, dynamic torsional tests were also developed in the factory to verify the predicted dynamically coupled blade-disc frequencies fo
24、r the low-pressure rotors. These factory tests were very useful in identifying any necessary corrective actions before the product went in service. However, it is not always possible to test all the rotor elements that comprise the assembly. Hence, unless testing is carried out on the fully assemble
25、d train on site, some discrepancy could still exist between the overall system models and the actual installed machine. There is inevitably some uncertainty regarding the accuracy of the calculated and measured torsional natural frequencies. It is therefore necessary to design overall system torsion
26、al frequencies with sufficient margin from the grid system frequencies to compensate for such inaccuracies. The acceptable margins will vary depending on the extent to which any experimental validation of the calculated torsional frequencies is carried out. The main objective of this part of ISO 222
27、66 is to provide guidelines for the selection of frequency margins in design and on the fully coupled machine on site. In general, the presence of a natural frequency is only of concern if it coincides with an excitation frequency within the margins defined in this part of ISO 22266 and has a modal
28、distribution allowing energy to be fed into the corresponding vibration mode. If either of these conditions is not satisfied, the presence of a natural frequency is of no practical consequence, i.e. a particular mode of vibration is of no concern if it cannot be excited. In the context of this part
29、of ISO 22266, the excitation is due to variations in the electromechanical torque, which is induced at the air gap of the generator. Any shaft torsional modes that are insensitive to these induced excitation torques do not present a risk to the integrity of the turbine generator, regardless of the v
30、alue of the natural frequency of that mode (see 4.2 and 5.2). BS ISO 22266-1:2009BS ISO 22266-1:2009INTERNATIONAL STANDARD ISO 22266-1:2009(E) ISO 2009 All rights reserved 1Mechanical vibration Torsional vibration of rotating machinery Part 1: Land-based steam and gas turbine generator sets in exces
31、s of 50 MW 1 Scope This part of ISO 22266 provides guidelines for applying shaft torsional vibration criteria, under normal operating conditions, for the coupled shaft system and long blades of a turbine generator set. In particular, these apply to the torsional natural frequencies of the coupled sh
32、aft system at line and twice line frequencies of the electrical network to which the turbine generator set is connected. In the event that torsional natural frequencies do not conform with defined frequency margins, other possible actions available to vendors are defined. This part of ISO 22266 is a
33、pplicable to land-based steam turbine generator sets for power stations with power outputs greater than 50 MW and normal operating speeds of 1 500 r/min, 1 800 r/min, 3 000 r/min and 3 600 r/min, and land-based gas turbine generator sets for power stations with power outputs greater than 50 MW and n
34、ormal operating speeds of 3 000 r/min and 3 600 r/min. Methods currently available for carrying out both analytical assessments and test validation of the shaft system torsional natural frequencies are also described. 2 Normative references The following referenced documents are indispensable for th
35、e application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 2041:1), Mechanical vibration, shock and condition monitoring Vocabulary ISO 2710-1, Reciprocating inter
36、nal combustion engines Vocabulary Terms for engine design and operation ISO 2710-2, Reciprocating internal combustion engines Vocabulary Terms for engine maintenance 1) To be published. (Revision of ISO 2041:1990) BS ISO 22266-1:2009ISO 22266-1:2009(E) 2 ISO 2009 All rights reserved3 Terms and defin
37、itions For the purposes of this document, the terms and definitions given in ISO 2041, ISO 2710-1 and ISO 2710-2 and the following apply. 3.1 set assembly of one or more elements such as high-pressure, intermediate-pressure, low-pressure turbines and generator and exciter elements 3.2 shaft system f
38、ully connected assembly of all the rotating components of a set NOTE 1 Figure 1 shows an example. NOTE 2 When the torsional natural frequencies are calculated, it is the complete shaft system that is considered. 3.3 torsional vibration oscillatory angular deformation (twist) of a rotating shaft syst
39、em 3.4 torsional vibration magnitude maximum oscillatory angular displacement measured in a cross section perpendicular to the axis of the shaft system between the angular position considered and a given arbitrary reference position 3.5 natural frequency frequency of free vibration of an undamped li
40、near vibration system NOTE 1 The same definition is given for natural frequency of a mechanical system in ISO 2041. NOTE 2 It is usually not necessary to calculate the natural frequency for a damped system, which is 2dn1 = where is the damping ratio. 3.6 modal vector relative magnitude for the whole
41、 section, where the system is vibrating at its associated natural frequency and an arbitrary cross section of the system is chosen as a reference and given a magnitude of unity 3.7 torsional mode shape shape produced by connecting the modal vector magnitudes at each section 3.8 vibratory node point
42、on a mode shape where the relative modal vector magnitude is equal to zero 3.9 natural mode of torsional vibration torsional mode shape which is produced when the shaft is vibrating at its natural frequency EXAMPLE First mode of vibration or one-node mode of vibration, second mode of vibration or tw
43、o-node mode of vibration. NOTE Figure 2 shows examples. BS ISO 22266-1:2009ISO 22266-1:2009(E) ISO 2009 All rights reserved 33.10 excitation torque torsional torque produced by the generator, exciter or driven components that excites torsional vibration of the shaft system 3.11 harmonic each term of
44、 the Fourier series of the excitation or response signal 3.12 all-in-phase mode mode of vibration in which all blades in a particular row vibrate in phase with one another NOTE When the rotor disc and the blades couple under dynamic conditions, the combined system produces several new “all-in-phase”
45、 frequencies that are different from the individual disc and blade frequencies (see Figure 3). These modes are often referred to as zero-nodal diameter or “umbrella” modes. 3.13 resonant speed characteristic speed at which resonances of the shaft system are excited EXAMPLE The shaft speed at which t
46、he natural frequency of a torsional vibration mode equals the frequency of one of the harmonics of the excitation torques. NOTE The same definition is given for resonant speed/critical speed in ISO 2041. 3.14 additional torsional stress stress due to the torsional vibrations of a given excitation ha
47、rmonic superimposed on the torsional stress corresponding to the mean torque transmitted in the given section of the shaft system being considered Key 1 high-pressure (HP) rotor 2 low-pressure (LP) rotor 1 3 blades 4 LP rotor 2 5 LP rotor 3 6 generator rotor 7 excitation torque applied 8 exciter Fig
48、ure 1 Six-rotor steam turbine generator system BS ISO 22266-1:2009ISO 22266-1:2009(E) 4 ISO 2009 All rights reserveda) Second mode of vibration or two-node mode of vibration b) Sixth mode of vibration or six-node mode of vibration Figure 2 Typical torsional mode shapes of the shaft system BS ISO 222
49、66-1:2009ISO 22266-1:2009(E) ISO 2009 All rights reserved 5Frequencies in hertz a) Uncoupled frequencies of separated blade and disc b) Coupled frequencies of blade-disc assembly aRotor central axis. Figure 3 Schematic illustration of blade-disc dynamic coupling 3.15 synthesized torsional stress dynamic torsional stress generated at a section of the shaft system given by the vector sum of all the harmonics of the excitation torques, taking into account both the magnitude and phase of the s
