1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 12952-4:2011Water-tube boilers andauxiliary installationsPart 4: In-service boiler life expectancycalculationsBS EN 12952-4:2011 BRITISH STANDARDNational forewordThis Briti
2、sh Standard is the UK implementation of EN 12952-4:2011.It supersedes BS EN 12952-4:2000 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PVE/2, Water Tube And Shell Boilers.A list of organizations represented on this committee can beobtained on request
3、to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 63554 0ICS 23.020.01; 27.040; 27.060.30Compliance with a British Standard cannot confer immunity fromlegal obligations.Thi
4、s British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2011.Amendments issued since publicationDate Text affectedBS EN 12952-4:2011EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12952-4 July 2011 ICS 27.040 Supersedes EN 12952-4:2000Engl
5、ish Version Water-tube boilers and auxiliary installations - Part 4: In-service boiler life expectancy calculations Chaudires tubes deau et installations auxiliaires - Partie 4: Calculs de la dure de vie prvisible des chaudires en service Wasserrohrkessel und Anlagenkomponenten - Teil 4: Betriebsbeg
6、leitende Berechnung der Lebensdauererwartung This European Standard was approved by CEN on 18 June 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration
7、. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by t
8、ranslation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Fi
9、nland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES
10、 KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12952-4:2011: EBS EN 12952-4:2011EN 12952-4:2011 (E) 2 Contents Page Foreword . 31 Scope 52 Normative ref
11、erences 53 Terms and definitions . 54 Symbols and abbreviations 55 General . 56 Calculations . 5Annex A (informative) Calculation of in-service creep damage . 6Annex B (informative) Calculation of in-service fatigue damage . 10Annex C (informative) Significant technical changes between this European
12、 Standard and the previous edition . 20Bibliography 21BS EN 12952-4:2011EN 12952-4:2011 (E) 3 Foreword This document (EN 12952-4:2011) has been prepared by Technical Committee CEN/TC 269 “Shell and water-tube boilers”, the secretariat of which is held by DIN. This European Standard shall be given th
13、e status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2012, and conflicting national standards shall be withdrawn at the latest by January 2012. Attention is drawn to the possibility that some of the elements of this document may be t
14、he subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 12952-4:2000. Annex C provides details of significant technical changes between this European Standard and the previous edition. The European Stand
15、ard EN 12952, concerning water-tube boilers and auxiliary installations, consists of the following parts: Part 1: General; Part 2: Materials for pressure parts of boilers and accessories; Part 3: Design and calculation for pressure parts; Part 4: In-service boiler life expectancy calculations; Part
16、5: Workmanship and construction of pressure parts of the boiler; Part 6: Inspection during construction; documentation and marking of pressure parts of the boiler; Part 7: Requirements for equipment for the boiler; Part 8: Requirements for firing systems for liquid and gaseous fuels for the boiler;
17、Part 9: Requirements for firing systems for pulverized solid fuels for the boiler; Part 10: Requirements for safeguards against excessive pressure; Part 11: Requirements for limiting devices of the boiler and accessories; Part 12: Requirements for boiler feedwater and boiler water quality; Part 13:
18、Requirements for flue gas cleaning systems; Part 14: Requirements for flue gas DENOX-systems using liquified pressurized ammonia and ammonia water solution; Part 15: Acceptance tests; Part 16: Requirements for grate and fluidized-bed firing systems for solid fuels for the boiler; CR 12952 Part 17: G
19、uideline for the involvement of an inspection body independent of the manufacturer. BS EN 12952-4:2011EN 12952-4:2011 (E) 4 NOTE 1 A Part 18 on operating instructions is currently in preparation. Although these parts may be obtained separately, it should be recognized that the parts are inter-depend
20、ent. As such, the design and manufacture of water-tube boilers requires the application of more than one part in order for the requirements of this European Standard to be satisfactorily fulfilled. NOTE 2 Part 4 and Part 15 are not applicable during the design, construction and installation stages.
21、NOTE 3 A “Boiler Helpdesk“ has been established in CEN/TC 269 which may be contacted for any questions regarding the application of European Standards series EN 12952 and EN 12953, see the following website: http:/www.boiler-helpdesk.din.de According to the CEN/CENELEC Internal Regulations, the nati
22、onal standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands,
23、 Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 12952-4:2011EN 12952-4:2011 (E) 5 1 Scope This European Standard is applicable to water-tube boilers as defined in EN 12952-1:2001. This European Standard specifies procedures for calcula
24、ting the creep and/or the fatigue damage of boiler components during operation. These calculations are not required to be carried out by the manufacturer as part of his responsibilities within this European Standard. 2 Normative references The following referenced documents are indispensable for the
25、 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. EN 12952-1:2001, Water-tube boilers and auxiliary installations Part 1: General EN 12952-3:2011, Water-tube b
26、oilers and auxiliary installations Part 3: Design and calculation for pressure parts 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12952-1:2001 apply. 4 Symbols and abbreviations For the purposes of this document, the symbols and abbreviations given
27、 in EN 12952-1:2001, Table 4-1 apply. 5 General The calculations may be carried out, using transposed design equations. The measured (actual) wall thickness of the components shall be used in the calculations, i.e. taking into account any wall thickness reduction that may have occurred due to corros
28、ion or erosion during the service life up to the time of the analysis, see EN 12952-3:2011, 5.7. Operating temperature, pressure and especially the magnitude of load changes often differ from the estimations used for the design. Thus, these calculations may help to prevent unexpected early failure o
29、f components. The results may be used as a guideline for the decision to inspect a component for fatigue cracks or to inspect for creep pores by the replica method or any other suitable method. NOTE In some cases, the influence of both creep and fatigue damage will be significant. It is normally con
30、servative to combine the creep and fatigue damage mechanisms by adding the calculated usage factors. If necessary, more detailed methods of assessment may be used (see 1 PD 7910 Published by British Standardization Institute, London, UK). Thus, the components are not necessarily to be replaced, if t
31、he calculated usage factor exceeds the value of 1. The highest loaded components shall be chosen for monitoring purposes. 6 Calculations Annex A describes the creep damage calculation. Annex B describes the fatigue damage calculation. BS EN 12952-4:2011EN 12952-4:2011 (E) 6 Annex A (informative) Cal
32、culation of in-service creep damage A.1 General This annex describes a procedure for calculating the creep damage of a boiler and its major components during operation. It is based on measured values of pressure and temperature, from which the actual primary stress and the expected lifetime at these
33、 conditions may be determined. Design lifetime is not necessarily identical with the operating lifetime. It is therefore necessary to make projections at various stages throughout the operating lifetime of the boiler to determine its expected lifetime. A.2 Symbols and abbreviations In addition to th
34、e symbols given in EN 12952-1:2001, Table 4-1, the symbols given in Table A.1 apply. Table A.1 Symbols Symbol Description Unit fopMembrane stress at operating conditions N/mm2TopOperated time at operating conditions h TalTime to reach the theoretical rupture by creep h DcCreep damage A.3 Calculation
35、 of in-service lifetime and creep damage A.3.1 General The calculation of the usage factor due to creep is a method that retrospectively takes into consideration the previous modes of operation. It is carried out for highly loaded components on the basis of the measured operating temperatures and ga
36、uge pressures. In order to limit the number of the required calculations and to more clearly present the results, the pressure and temperature range over which the component has been operated, shall be broken down into increments. The membrane stress fopat the highest loaded point in the component s
37、hall be obtained by transposing the design formula using the mean pressure of each pressure increment. If the operating pressure is not measured continuously during operation the separation into increments is not valid and under such circumstances the operating pressure for 100 % load may be used, t
38、hus resulting in more conservative predictions. If available, the measured minimum wall thickness may be used. If this was not measured, the guaranteed minimum wall thickness of the material as delivered shall be used. The theoretical lifetime Talshall be calculated for each rating temperature/press
39、ure. According to Figure A.1, Talis obtained at the intersection of the stress line fopand the lower limit curve of the scatter band of the creep rupture strength (= 0,8 Rm T tc) at the mean temperature of each temperature increment. The respective portion of the creep damage Dci kfor each increment
40、al temperature/pressure is obtained by the ratio of the operating time Topfor this increment divided by the theoretical lifetime Talfor the same increment. BS EN 12952-4:2011EN 12952-4:2011 (E) 7 Key a) lg (Rm) b) lg (T), h Figure A.1 Diagram for the determination of TalThe operating times in the te
41、mperature/pressure increment shall be summarized, taking into account the temperature allowances for measuring uncertainties and for temperature asymmetries in due consideration at this classification. The usage portion for each increment is given by alopkciTTD = (A.1) The creep damage Dcduring the
42、evaluated period shall be obtained from the linear damage rule by summing up the values Dci kfor all temperature increments and, if any, pressure as follows: =ikkcicDD (A.2) A.3.2 Online computerized data storage In the case of on-line data storage by means of a data processing system a separation i
43、nto increments may be waived. For calculation of the theoretical lifetime Talthe on-line measured values of pressure and temperature including the above mentioned allowances shall be used instead of the mean values of the increments. The increase of creep damage is obtained in this case from the mea
44、sured time divided by the theoretical lifetime (see Tables A.2 and A.3). The computer programme used shall permit the results to be verified by at least a random test. BS EN 12952-4:2011EN 12952-4:2011 (E) 8 Table A.2 Summation of data for the calculation of in-service creep damage User and boiler p
45、lant: XY Power station: XY Boiler: 3 Works-No.: 12345 Year built: 2003 Maximum allowable pressure HP: 84 bar Reheater: bar Superheated steam temperature: HP: 525 C Reheater: C Steam output: 128 t/h 1 2 3 4 5 6 7 8 9 10 11 12 13 No. Component Material; Steel group a b d mm c esmm ersmm pcbar to Ctc C
46、 fapN/mm2Tal 103h 1 HP-line 13CrMo44; 5.1 m AB292,0 o 24,0 21,0 75,5 525 530 48,7 208 2 Superheater 2 header 13CrMo44; 5.1 n AB419,0 o 39,0 39,0 75,5 510 525 56,3 186 3 Superheater 2 outlet line 13CrMo44; 5.1 n AB241,0 o 17,5 17,5 75,5 510 525 48,2 304 4 Superheater 2 outlet header 16CrMo44; 5.1 n A
47、B250,0 i 20,0 28,0 75,5 510 525 47,1 329 7 Fitting at control 20Mo3; 1.2 m AB225,0 i 28,0 20,0 80,4 460 465 86,6 500 11 Superheater 1 outlet line 16Mo3; 1.1 n AB241,0 o 14,0 14,0 80,4 460 475 65,2 500 12 Superheater 1 outlet header 20Mo3; 1.2 n AB250,0 i 22,0 22,0 80,4 460 475 67,0 500 aColumn 3: Te
48、mperature allowances according to EN 12952-3:2011, Table 6.1-1 m unheated = mixed or controlled (+ 5 C) n unheated (+ 15 C) bColumn 4: A Nominal or design values B Operational or actual values cColumn 6: i Inside diameter o Outside diameter BS EN 12952-4:2011EN 12952-4:2011 (E) 9 Table A.3 Summation
49、 of data for the calculation of in-service creep damage User and boiler plant: XY Power station: XY Boiler: 6 Works-No.: 12345 Component: Connecting pipes between primary super heater and secondary super heater 90 8 Commissioning: 2003 Material: Steel group 5.1 (13CrMo44) Calculation pressure pc: 100 bar Mean wall temperature tc: 530 C Stress at pc: 57,5 N/mm2Evaluated period: from to 1 2 3 4 5 6 7 Evalu-ation range At outlet of component Ca
