1、August 2012 Translation by DIN-Sprachendienst.English price group 14No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS
2、 21.120.40!$k)“1907206www.din.deDDIN ISO 21940-13Mechanical vibration Rotor balancing large rotors (ISO 21940-13:2012),English translation of DIN ISO 21940-13:2012-08Mechanische Schwingungen Auswuchten von Rotoren Teil 13: Kriterien und Sicherheitshinweise fr das Auswuchten von mittleren und groenRo
3、toren am Aufstellungsort (ISO 21940-13:2012),Englische bersetzung von DIN ISO 21940-13:2012-08Vibrations mcaniques SupersedesDIN ISO 20806:2010-03www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.Part 13: Criteria and safeguards for
4、the in-situ balancing of medium and 29quilibrage des rotors Partie 13: Critres et sauvegardes relatifs lquilibrage in situ des rotors moyens et grands (ISO 21940-13:2012), Traduction anglaise de DIN ISO 21940-13:2012-08 07.12 DIN ISO 21940-13:2012-08 2 A comma is used as the decimal marker. Contents
5、 Page National foreword .3 National Annex NA (informative) Bibliography 5 Introduction .6 1 Scope 7 2 Normative references 7 3 Terms and definitions .8 4 In-situ balancing 8 4.1 General 8 4.2 Reasons for in-situ balancing 8 4.3 Objectives of in-situ balancing .9 5 Criteria for performing in-situ bal
6、ancing .9 6 Safeguards 10 6.1 Safety of personnel while operating close to a rotating shaft . 10 6.2 Special operating envelope for in-situ balancing 10 6.3 Integrity and design of the correction masses and their attachments . 10 6.4 Machinery-specific safety implications 10 7 Measurements . 11 7.1
7、Vibration measurement equipment 11 7.2 Measurement errors . 11 7.3 Phase reference signals . 12 8 Operational conditions . 13 9 Reporting . 14 9.1 General . 14 9.2 Report introduction 15 9.3 Vibration measurement equipment 15 9.4 Results . 15 9.5 Text information 16 Annex A (normative) Precautions a
8、nd safeguards for specific machine types during in-situ balancing . 18 Annex B (informative) Example of an in-situ balancing report for a boiler fan 1 MW . 19 Annex C (informative) Example of an in-situ balancing report for a large 50 MW turbine generator set . 23 Bibliography . 29 National foreword
9、 This standard includes safety requirements. This standard has been prepared by Technical Committee ISO/TC 108 “Mechanical vibration, shock and condition monitoring”, Subcommittee SC 2 “Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures” (Sec
10、retariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Akustik, Lrmminderung und Schwingungstechnik im DIN und VDI (Acoustics, Noise Control and Vibration Engineering Standards Committee in DIN and VDI), Working Committee NA 001-03-06-01 (NALS/VDI C
11、6.1) Auswuchten und Auswuchtmaschinen. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. DIN and/or DKE shall not be held responsible for identifying any or all such patent rights. The DIN Standards corresponding to the Internationa
12、l Standards referred to in this document are as follows: ISO 1925 DIN ISO 1925 ISO 1940-1 DIN ISO 1940-1 ISO 2954 DIN ISO 2954 ISO 7919 standards series DIN ISO 7919 standards series ISO 10816 standards series DIN ISO 10816 standards series ISO 10817-1 DIN ISO 10817-1 ISO 11342 DIN ISO 11342 ISO 133
13、73-1 DIN ISO 13373-1 ISO 21940-14 DIN ISO 21940-14 The German standards are listed in the National Annex NA. ISO 21940 consists of the following parts, under the general title Mechanical vibration Rotor balancing: Part 1: Introduction1) Part 2: Vocabulary2) Part 11: Procedures and tolerances for rot
14、ors with rigid behaviour3) Part 12: Procedures and tolerances for rotors with flexible behaviour4)3 DIN ISO 21940-13:2012-08 Part 13: Criteria and safeguards for the in-situ balancing of medium and large rotors5)1) Revision of ISO 19499:2007, Mechanical vibration Balancing Guidance on the use and ap
15、plication of balancing standards 2) Revision of ISO 1925:2001, Mechanical vibration Balancing Vocabulary 3) Revision of ISO 1940-1:2003 + Cor.1:2005, Mechanical vibration Balance quality requirements for rotors in a constant (rigid) state Part 1: Specification and verification of balance tolerances
16、4) Revision of ISO 11342:1998 + Cor.1:2000, Mechanical vibration Methods and criteria for the mechanical balancing of flexible rotors5) Revision of ISO 20806:2009, Mechanical vibration Criteria and safeguards for the in-situ balancing of medium and large rotors Part 14: Procedures for assessing bala
17、nce errors6) Part 21: Description and evaluation of balancing machines7) Part 23: Enclosures and other protective measures for balancing machines8) Part 31: Susceptibility and sensitivity of machines to unbalance9) Part 32: Shaft and fitment key convention10)Amendments This standard differs from DIN
18、 ISO 20806:2010-03 as follows: a) the number of the standard has been changed; b) the standard has been editorially revised and updated. Previous editions DIN ISO 20806: 2005-03, 2010-03 6) Revision of ISO 1940-2:1997, Mechanical vibration Balance quality requirements of rigid rotors Part 2: Balance
19、 errors 7) Revision of ISO 2953:1999, Mechanical vibration Balancing machines Description and evaluation 8) Revision of ISO 7475:2002, Mechanical vibration Balancing machines Enclosures and other protective measures for the measuring station 9) Revision of ISO 10814:1996, Mechanical vibration Suscep
20、tibility and sensitivity of machines to unbalance 10) Revision of ISO 8821:1989, Mechanical vibration Balancing Shaft and fitment key convention 4 DIN ISO 21940-13:2012-08 National Annex NA (informative) Bibliography DIN ISO 1925, Mechanical vibration Balancing Vocabulary DIN ISO 1940-1, Mechanical
21、vibration Balance quality requirements for rotors in a constant (rigid) state Part 1: Specification and verification of balance tolerances DIN ISO 2954, Mechanical vibration of rotating and reciprocating machinery Requirements for instruments for measuring vibration severity DIN ISO 7919 (all parts)
22、, Mechanical vibration Evaluation of machine vibration by measurements on rotating shafts DIN ISO 10816 (all parts), Mechanical vibration Evaluation of machine vibration by measurements on non-rotating parts DIN ISO 10817-1, Rotating shaft vibration measuring systems Part 1: Relative and absolute se
23、nsing of radial vibration DIN ISO 11342, Mechanical vibration Methods and criteria for the mechanical balancing of flexible rotors DIN ISO 13373-1:2002-07, Condition monitoring and diagnostics of machines Vibration condition monitoring Part 1: General procedures DIN ISO 21940-14, Mechanical vibratio
24、n Rotor balancing Part 14: Balance quality requirements of rigid and flexible rotors Balance errors 5 DIN ISO 21940-13:2012-08 Introduction Balancing is the process by which the mass distribution of a rotor is checked and, if necessary, adjusted to ensure that the residual unbalance or the vibration
25、s of the journals or bearing supports and/or the forces at the bearings are within specified limits. Many rotors are balanced in specially designed balancing facilities prior to installation into their bearings on site. However, if remedial work is carried out locally or a balancing machine is not a
26、vailable, it is common to balance the rotor in situ. Unlike balancing in a specially designed balancing machine, in-situ balancing has the advantage that the rotor is installed in its working environment. Therefore, there is no compromise with regard to the dynamic properties of its bearings and sup
27、port structure, nor from the influence of other elements in the complete rotor train. However, it has the large disadvantage of restricted access and the need to operate the whole machine. Restricted access can limit the planes at which correction masses can be added, and using the whole machine has
28、 commercial penalties of both downtime and running costs. Where gross unbalance exists, it may not be possible to balance a rotor in situ due to limited access to correction planes and the size of correction masses available. Mechanical vibration Rotor balancing Part 13: Criteria and safeguards for
29、the in-situ balancing of medium and large rotors 6 DIN ISO 21940-13:2012-08 1 Scope This part of ISO 21940 specifies procedures to be adopted when balancing medium and large rotors installed in their own bearings on site. It addresses the conditions under which it is appropriate to undertake in-situ
30、 balancing, the instrumentation required, the safety implications and the requirements for reporting and maintaining records. This part of ISO 21940 can be used as a basis for a contract to undertake in-situ balancing. It does not provide guidance on the methods used to calculate the correction mass
31、es from measured vibration data. NOTE The procedures covered in this part of ISO 21940 are suitable for medium and large machines. However, many of the principles are equally applicable to machines of a smaller size, where it is necessary to maintain good records of the vibration behaviour and the c
32、orrection mass configurations. 2 Normative references The following referenced documents are indispensable for the 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) appl
33、ies. ISO 1925, Mechanical vibration Balancing Vocabulary11)ISO 1940-1, Mechanical vibration Balance quality requirements for rotors in a constant (rigid) state Part 1: Specification and verification of balance tolerances12)ISO 2954, Mechanical vibration of rotating and reciprocating machinery Requir
34、ements for instruments for measuring vibration severity ISO 7919 (all parts), Mechanical vibration Evaluation of machine vibration by measurements on rotating shafts ISO 10816 (all parts), Mechanical vibration Evaluation of machine vibration by measurements on non-rotating parts ISO 10817-1, Rotatin
35、g shaft vibration measuring systems Part 1: Relative and absolute sensing of radial vibration ISO 11342, Mechanical vibration Methods and criteria for the mechanical balancing of flexible rotors13)11) To become ISO 21940-2 when revised. 12) To become ISO 21940-11 when revised. 13) To become ISO 2194
36、0-12 when revised. 7 DIN ISO 21940-13:2012-08 8 DIN ISO 21940-13:2012-08 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 1925 apply. 4 In-situ balancing 4.1 General For in-situ balancing, correction masses are added to the rotor at a limited number o
37、f conveniently engineered and accessible locations along the rotor. By doing this, the magnitude of shaft and/or pedestal vibrations and/or unbalance is reduced to within acceptable values, so that the machine can operate safely throughout its whole operating envelope. As part of a successful balanc
38、e, transient-speedN1)vibration might be comprom-ised to some degree to obtain acceptable normal running speed vibration on a fixed-speed machinery train. NOTE In certain cases, machines that are very sensitive to unbalance cannot be successfully balanced over the complete operating envelope. This us
39、ually occurs when a machine is operating at a speed close to a lightly damped system mode (see ISO 10814 to become ISO 21940-31 when revised) and has load-dependent unbalance. Most sites have limited instrumentation and data-processing capabilities, when compared to a balancing machine, and addition
40、al instrumentation is required to undertake in-situ balancing in these situations. In addition, the potential safety implications of running a rotor with correction masses shall be taken into account. 4.2 Reasons for in-situ balancing 4.2.1 Although individual rotors might be correctly balanced, as
41、appropriate, in a high- or low-speed balancing machine, in-situ balancing may be required when the rotors are coupled into the complete rotor train. This can be due to a range of differences between the real machine and the isolated environment in the balancing machine, including: a) a difference in
42、 dynamic characteristics of the rotor supports between the balancing facility and the installed machine; b) assembly errors that occur during installation, which cannot be reasonably found and corrected; c) rotor systems that cannot be balanced prior to assembly; d) a changing unbalance behaviour of
43、 the rotor under full functional operating conditions. 4.2.2 Balancing may also be required to compensate for in-service changes to the rotor, including: a) wear; b) loss of components, such as rotor blade erosion shields; c) repair work, where components can be changed or replaced; d) movement of c
44、omponents on the rotor train causing unbalance, such as couplings, gas turbine discs and generator end rings. NOTE Rotor blades are normally added as balanced sets, but this can be impossible if a small number of blades are replaced. N1) National footnote: Transient conditions are those conditions u
45、nder which speed changes, e.g. start-up and rundown. 4.2.3 In-situ balancing may be necessary due to a range of economic and technical reasons, including: a) the investment in a balancing machine cannot be justified; b) when a suitable balancing machine is not available in the correct location or at
46、 the required time; c) when it is not economic to dismantle the machine and transport the rotor(s) to a suitable balancing facility. 4.2.4 Machines under normal operation or during speed variations (following remedial work, or after commissioning) can have unacceptable magnitudes of vibration when c
47、ompared with common practice, contractual requirements, or International Standards such as ISO 7919 and ISO 10816. In many cases, it is possible to bring the machine within acceptable vibration magnitude by in-situ balancing. 4.3 Objectives of in-situ balancing The reason for balancing is to reduce
48、the vibration magnitudes to acceptable values for long-term operation. For most machines, the overall vibration magnitude limits shall either be based on common practice or the appropriate part of ISO 7919 (for shaft vibration) and ISO 10816 (for bearing housing and pedestal vibration). Where the magnitude of unbalance is of concern, reduce the magnitude of unbalance to within permissible limits (see ISO 1940-1 and ISO 11342 for details). 5 Criteria fo
