1、BRITISH STANDARDBS EN 62256:2008Hydraulic turbines, storage pumps and pump-turbines Rehabilitation and performance improvementICS 27.140g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g3
2、8g50g51g60g53g44g42g43g55g3g47g36g58BS EN 62256:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 August 2008 BSI 2008ISBN 978 0 580 54882 6National forewordThis British Standard is the UK implementation of EN 62256:2008. It is identical
3、 to IEC 62256:2008. The UK participation in its preparation was entrusted to Technical Committee MCE/15, Hydraulic turbines.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a
4、 contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsEUROPEAN STANDARD EN 62256 NORME EUROPENNE EUROPISCHE NORM May 2008 CENELEC European Committee for
5、Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
6、Ref. No. EN 62256:2008 E ICS 27.140 English version Hydraulic turbines, storage pumps and pump-turbines - Rehabilitation and performance improvement (IEC 62256:2008) Turbines hydrauliques, pompes daccumulation et pompes turbines - Rhabilitation et amlioration des performances (CEI 62256:2008) Wasser
7、turbinen, Speicherpumpen und Pumpturbinen - Modernisierung und Verbesserung der Leistungseigenschaften (IEC 62256:2008) This European Standard was approved by CENELEC on 2008-04-16. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for givin
8、g this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official ve
9、rsions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees
10、of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kin
11、gdom. Foreword The text of document 4/231/FDIS, future edition 1 of IEC 62256, prepared by IEC TC 4, Hydraulic turbines, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 62256 on 2008-04-16. The following dates were fixed: latest date by which the EN has to be impleme
12、nted at national level by publication of an identical national standard or by endorsement (dop) 2009-02-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2011-05-01 _ Endorsement notice The text of the International Standard IEC 62256:2008 was approved
13、 by CENELEC as a European Standard without any modification. _ BS EN 62256:2008 2 CONTENTS INTRODUCTION.7 1 Scope and object8 2 Nomenclature .8 3 Reasons for rehabilitating.9 3.1 General .9 3.2 Reliability and availability increase 11 3.3 Life extension and performance restoration .12 3.4 Performanc
14、e improvement.12 3.5 Plant safety improvement 12 3.6 Environmental, social and regulatory issues 12 3.7 Maintenance and operating cost reduction.13 3.8 Other considerations .13 4 Phases of a rehabilitation project13 4.1 General .13 4.2 Decision on organization .15 4.2.1 General .15 4.2.2 Expertise r
15、equired .15 4.2.3 Contract arrangement16 4.3 Level of assessment and determination of scope.16 4.3.1 General .16 4.3.2 Feasibility study Stage 1.17 4.3.3 Feasibility study Stage 2.17 4.3.4 Detailed study .17 4.4 Contractual issues.23 4.4.1 General .23 4.4.2 Specification requirements 23 4.4.3 Tender
16、ing documents and evaluation of tenders23 4.4.4 Contract Award(s)24 4.5 Execution of project.24 4.5.1 Model test activities.24 4.5.2 Design, construction, installation and testing .25 4.6 Evaluation of results and compliance with guarantees .25 4.6.1 General .25 4.6.2 Turbine performance evaluation
17、26 4.6.3 Generator performance evaluation.26 4.6.4 Penalties and/or bonuses assessment.26 5 Scheduling, cost analysis and risk analysis 26 5.1 Scheduling 26 5.1.1 General .26 5.1.2 Scheduling Assessment, feasibility and detailed study phases27 5.1.3 Evaluating the scheduling component of alternative
18、s.27 5.1.4 Scheduling specification and tendering phase .28 5.1.5 Scheduling project execution phases.29 5.2 Economic and financial analyses.29 BS EN 62256:2008 3 5.2.1 General .29 5.2.2 Benefit-cost analysis .30 5.2.3 Identification of anticipated benefits.31 5.2.4 Identification of anticipated cos
19、ts and benefits.32 5.2.5 Sensitivity analysis 33 5.2.6 Conclusions.34 5.3 Risk analysis .34 5.3.1 General .34 5.3.2 Non-achievement of performance risk35 5.3.3 Risk of continued operation without rehabilitation 35 5.3.4 Extension of outage risk 35 5.3.5 Financial risks .36 5.3.6 Project scope risk36
20、 5.3.7 Other risks.37 6 Assessment and determination of scope of the work.37 6.1 General .37 6.2 Assessment of the site 38 6.2.1 Hydrology38 6.2.2 Actual energy production .38 6.2.3 Environmental social and regulatory issues .39 6.3 The assessment of the turbine 40 6.3.1 General .40 6.3.2 Turbine in
21、tegrity assessment .69 6.3.3 Residual life 78 6.3.4 Turbine performance assessment 79 6.4 The assessment of related equipment .101 6.4.1 General .101 6.4.2 Generator and thrust bearing.106 6.4.3 Turbine governor .108 6.4.4 Turbine inlet and outlet valves, pressure relief valve108 6.4.5 Auxiliary equ
22、ipment .108 6.4.6 Equipment for erection, dismantling and maintenance .109 6.4.7 Penstock and other water passages 109 6.4.8 Consequences of changes in plant specific hydraulic energy (head)110 7 Hydraulic design and performance testing options110 7.1 General .110 7.2 Computational hydraulic design.
23、111 7.2.1 General .111 7.2.2 The role of CFD.112 7.2.3 The process of a CFD cycle.112 7.2.4 The accuracy of CFD results .113 7.2.5 How to use CFD for rehabilitation 114 7.2.6 CFD versus model tests 114 7.3 Model tests115 7.3.1 General .115 7.3.2 Model test similitude116 7.3.3 Model test content .116
24、 7.3.4 Model test application117 7.3.5 Model test location 119 BS EN 62256:2008 4 7.4 Prototype performance test .120 7.4.1 General .120 7.4.2 Prototype performance test accuracy.121 7.4.3 Prototype performance test types 122 7.4.4 Evaluation of results 122 8 Specifications.123 8.1 General .123 8.2
25、Reference standards .123 8.3 Information to be included in the tender documents.124 8.4 Documents to be developed in the course of the project126 Bibliography128 Figure 1 Flow diagram depicting the logic of the rehabilitation process 14 Figure 2 Critical zones for cracks “A” and “B” in Pelton runner
26、 buckets 77 Figure 3 Relative efficiency versus relative output Original and new runners.81 Figure 4 Relative efficiency versus output Original and new runners Outardes 3 generating station .82 Figure 5 Efficiency and distribution of losses versus specific speed for Francis turbines (model) in 2005
27、.83 Figure 6 Relative efficiency gain following modification of the blades on the La Grande 3 runner, in Quebec, Canada.85 Figure 7a Potential efficiency improvement for Francis turbine rehabilitation90 Figure 7b Potential efficiency improvement for Kaplan turbine rehabilitation 91 Figure 8 Cavitati
28、on and corrosion-erosion in Francis runner.92 Figure 9 Back side erosion of the entrance into a Pelton bucket.93 Figure 10 Leading edge cavitation erosion on a Franis pump-turbine caused by extended periods of operation at very low loads94 Figure 11 Severe particle erosion damage in a Francis runner
29、.96 Table 1 Expected life of a hydropower plant and its subsystems before major work .11 Table 2 Assessment of turbine embedded parts Stay ring .42 Table 3 Assessment of turbine embedded parts Spiral or semi-spiral case43 Table 4 Assessment of turbine embedded parts Discharge ring 44 Table 5 Assessm
30、ent of turbine embedded parts Draft tube45 Table 6 Assessment of turbine non-embedded, non-rotating parts Headcover.46 Table 7 Assessment of turbine non-embedded, non-rotating parts Intermediate and inner headcovers 49 Table 8 Assessment of turbine non embedded, non rotating parts Bottom ring50 Tabl
31、e 9 Assessment of turbine non embedded, non rotating parts Guide vanes 52 Table 10 Assessment of turbine non embedded, non rotating parts Guide vane operating mechanism54 Table 11 Assessment of turbine non embedded, non rotating parts Operating ring55 Table 12 Assessment of turbine non embedded, non
32、 rotating parts Servomotors 56 Table 13 Assessment of turbine non embedded, non rotating parts Guide bearings 57 BS EN 62256:2008 5 Table 14 Assessment of turbine non embedded, non rotating parts Turbine shaft seal (mechanical seal or packing box) 59 Table 15 Assessment of turbine non embedded, non
33、rotating parts Thrust bearing support .59 Table 16 Assessment of turbine non embedded, non rotating parts Nozzles .60 Table 17 Assessment of turbine non embedded, non rotating parts Deflectors and energy dissipation.60 Table 18a Assessment of turbine rotating parts Runner 61 Table 18b Assessment of
34、turbine rotating parts Runner 64 Table 18c Assessment of turbine rotating parts Runner 65 Table 19 Assessment of turbine rotating parts Turbine shaft .66 Table 20 Assessment of turbine rotating parts Oil head and oil distribution pipes67 Table 21 Assessment of turbine auxiliaries Speed and load regu
35、lation system (governor).67 Table 22 Assessment of turbine auxiliaries Turbine aeration system .68 Table 23 Assessment of turbine auxiliaries Lubrication system (guide vane mechanism) 69 Table 24 Francis turbine potential efficiency improvement (%) for runner profile modifications only .84 Table 25
36、Potential impact of design and condition of runner seals on Francis turbine efficiency with new replacement runner or rehabilitated runner (%).87 Table 26 Potential total gain in efficiency from the replacement of a Francis turbine runner including the blade profile improvements, the restoration of
37、surface condition and the reduction of seal losses88 Table 27 Potential Additional Efficiency Improvement by Rehabilitation/Replacement of Other Water Passage Components on a Francis Turbine (%)88 Table 28 Assessment of related equipment - Governor 103 Table 29 Assessment of related equipment Genera
38、tor and thrust bearing .104 Table 30 Assessment of related equipment Penstock and turbine inlet valves.105 Table 31 Assessment of related equipment Civil works .106 Table 32 Assessment of related equipment Crane, erection equipment.106 BS EN 62256:2008 6 INTRODUCTION Hydro plant owners make signific
39、ant investments annually in rehabilitating plant equipment (turbines, generators, transformers, penstocks, gates etc.) and structures in order to improve the level of service to their customers and to optimize their revenue. In the absence of guidelines, owners may be spending needlessly, or may be
40、taking unnecessary risks and thereby achieving results that are less than optimal. This guide is intended to be a tool in the optimisation and decision process. IEC TC 4 wishes to thank IEA for providing its document “Guidelines on Methodology for Hydroelectric Francis Turbine Upgrading by Runner Re
41、placement” as a starting point for the writing of this document. IEC TC 4 appreciates this contribution and acknowledges that the IEA document provided a good foundation upon which to build this IEC document. BS EN 62256:2008 7 HYDRAULIC TURBINES, STORAGE PUMPS AND PUMP-TURBINES REHABILITATION AND P
42、ERFORMANCE IMPROVEMENT 1 Scope and object The scope of this International Standard covers turbines, storage pumps and pump-turbines of all sizes and of the following types: Francis; Kaplan; propeller; Pelton (turbines only); Bulb. Wherever turbines or turbine components are referred to in the text o
43、f this guide, they shall be interpreted also to mean the comparable units or components of storage pumps or pump-turbines as the case requires. The Guide also identifies without detailed discussion, other powerhouse equipment that could affect or be affected by a turbine, storage pump, or pump-turbi
44、ne rehabilitation. The object of this guide is to assist in identifying, evaluating and executing rehabilitation and performance improvement projects for hydraulic turbines, storage pumps and pump-turbines. This guide can be used by owners, consultants, and suppliers to define: needs and economics f
45、or rehabilitation and performance improvement; scope of work; specifications; evaluation of results. The Guide is intended to be: an aid in the decision process; an extensive source of information on rehabilitation; an identification of the key milestones in the rehabilitation process; an identifica
46、tion of the points that should be addressed in the decision processes. The Guide is not intended to be a detailed engineering manual nor a maintenance guide. 2 Nomenclature For the purpose of this document, the term “rehabilitation” is defined as some combination of: restoration of equipment capacit
47、y and/or equipment efficiency to near “as-new” levels; BS EN 62256:2008 8 extension of equipment life by re-establishing mechanical integrity. The term “performance improvement” means the increase of capacity and/or efficiency beyond those of the original machine and may be included as part of a reh
48、abilitation. Many other terms are in common use to define the work of “rehabilitation” and “performance improvement”, however it is suggested to use the above terms. Some of the terms considered and discarded for their lack of precision or completeness include: upgrade or upgrading restoration of me
49、chanical integrity and efficiency; uprating increase of nameplate capacity (power) which may result in part from efficiency restoration or improvement; overhaul restoration of mechanical integrity; modernization could mean performance improvement and replacement of obsolete technologies; redevelopment term frequently used to mean repla
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