EN 62256:2008

Hydraulic turbines, storage pumps and pump-turbines - Rehabilitation and performance improvement

Provides assistance in identifying, evaluating and executing rehabilitation and performance improvement projects for hydraulic turbines, storage pumps and pump-turbines of all sizes and of the following types: Francis; Kaplan; Propeller; Pelton (turbines only); Bulb.

Wasserturbinen, Speicherpumpen und Pumpturbinen - Modernisierung und Verbesserung der Leistungseigenschaften

Turbines hydrauliques, pompes d'accumulation et pompes turbines - Réhabilitation et amélioration des performances

Fournir une aide à l'identification, à l'évaluation et à l'exécution de projets de réhabilitation et d'amélioration des performances de turbines hydrauliques, de pompes d'accumulation et de pompes-turbines de toutes tailles et des types suivants: Francis; Kaplan; hélice; Pelton (turbines seulement); bulbe.

Vodne turbine, akumulacijske črpalke in črpalne turbine - Vodilo za prenavljanje in izboljšanje delovanja (IEC 62256:2008)

General Information

• Status: Withdrawn
• Publication Date: 27-May-2008
• Withdrawal Date: 30-Apr-2011
• ICS: 27.140 - Hydraulic energy engineering
• Technical Committee: CLC/SR 4 - Hydraulic turbines
• Drafting Committee: IEC/TC 4 - IEC_TC_4
• Parallel Committee: IEC/TC 4 - IEC_TC_4
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 04-Jul-2020
• Completion Date: 04-Jul-2020
• Ref Project: SIST EN 62256:2008 - Hydraulic turbines, storage pumps and pump-turbines - Rehabilitation and performance improvement

Relations

• Replaced By: EN 62256:2017 - Hydraulic turbines, storage pumps and pump-turbines - Rehabilitation and performance improvement
• Effective Date: 05-Sep-2017

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2008
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Hydraulic turbines, storage pumps and pump-turbines - Rehabilitation and performance
improvement
Wasserturbinen, Speicherpumpen und Pumpturbinen - Modernisierung und
Verbesserung der Leistungseigenschaften
Turbines hydrauliques, pompes d'accumulation et pompes turbines - Réhabilitation et
amélioration des performances
Ta slovenski standard je istoveten z: EN 62256:2008
ICS:
27.140 Vodna energija Hydraulic energy engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 62256
NORME EUROPÉENNE
May 2008
EUROPÄISCHE NORM
ICS 27.140
English version
Hydraulic turbines, storage pumps and pump-turbines -
Rehabilitation and performance improvement
(IEC 62256:2008)
Turbines hydrauliques, pompes Wasserturbinen, Speicherpumpen
d'accumulation et pompes turbines - und Pumpturbinen -
Réhabilitation et amélioration Modernisierung und Verbesserung
des performances der Leistungseigenschaften
(CEI 62256:2008) (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 giving 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 versions (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 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 Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für 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.
Ref. No. EN 62256:2008 E
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 implemented
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 by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60041 NOTE  Harmonized as EN 60041:1994 (modified).
IEC 60193 NOTE  Harmonized as EN 60193:1999 (not modified).
IEC 60609 NOTE  Harmonized in EN 60609 series (not modified).
IEC 60994 NOTE  Harmonized as EN 60994:1992 (not modified).
__________
IEC 62256
Edition 1.0 2008-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Hydraulic turbines, storage pumps and pump-turbines – Rehabilitation and
performance improvement
Turbines hydrauliques, pompes d'accumulation et pompes turbines –
Réhabilitation et amélioration des performances

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XF
CODE PRIX
ICS 27.140 ISBN 2-8318-9332-1
– 2 – 62256 © IEC:2008
CONTENTS
FOREWORD.6
INTRODUCTION.8

1 Scope and object.9
2 Nomenclature .9
3 Reasons for rehabilitating.10
3.1 General .10
3.2 Reliability and availability increase .12
3.3 Life extension and performance restoration .13
3.4 Performance improvement.13
3.5 Plant safety improvement .13
3.6 Environmental, social and regulatory issues .13
3.7 Maintenance and operating cost reduction.14
3.8 Other considerations .14
4 Phases of a rehabilitation project.14
4.1 General .14
4.2 Decision on organization .16
4.2.1 General .16
4.2.2 Expertise required .16
4.2.3 Contract arrangement.17
4.3 Level of assessment and determination of scope.17
4.3.1 General .17
4.3.2 Feasibility study – Stage 1.18
4.3.3 Feasibility study – Stage 2.18
4.3.4 Detailed study .18
4.4 Contractual issues.24
4.4.1 General .24
4.4.2 Specification requirements .24
4.4.3 Tendering documents and evaluation of tenders.24
4.4.4 Contract Award(s).25
4.5 Execution of project.25
4.5.1 Model test activities.25
4.5.2 Design, construction, installation and testing .26
4.6 Evaluation of results and compliance with guarantees .26
4.6.1 General .26
4.6.2 Turbine performance evaluation .27
4.6.3 Generator performance evaluation.27
4.6.4 Penalties and/or bonuses assessment.27
5 Scheduling, cost analysis and risk analysis .27
5.1 Scheduling .27
5.1.1 General .27
5.1.2 Scheduling – Assessment, feasibility and detailed study phases.28
5.1.3 Evaluating the scheduling component of alternatives .28
5.1.4 Scheduling specification and tendering phase .29
5.1.5 Scheduling project execution phases .30
5.2 Economic and financial analyses.30

62256 © IEC:2008 – 3 –
5.2.1 General .30
5.2.2 Benefit-cost analysis .31
5.2.3 Identification of anticipated benefits.32
5.2.4 Identification of anticipated costs and benefits.33
5.2.5 Sensitivity analysis .34
5.2.6 Conclusions.35
5.3 Risk analysis .35
5.3.1 General .35
5.3.2 Non-achievement of performance risk.36
5.3.3 Risk of continued operation without rehabilitation .36
5.3.4 Extension of outage risk .36
5.3.5 Financial risks .37
5.3.6 Project scope risk .37
5.3.7 Other risks.38
6 Assessment and determination of scope of the work.38
6.1 General .38
6.2 Assessment of the site .39
6.2.1 Hydrology .39
6.2.2 Actual energy production .39
6.2.3 Environmental social and regulatory issues .40
6.3 The assessment of the turbine .41
6.3.1 General .41
6.3.2 Turbine integrity assessment .70
6.3.3 Residual life .79
6.3.4 Turbine performance assessment .80
6.4 The assessment of related equipment .102
6.4.1 General .102
6.4.2 Generator and thrust bearing.107
6.4.3 Turbine governor .109
6.4.4 Turbine inlet and outlet valves, pressure relief valve. 109
6.4.5 Auxiliary equipment .109
6.4.6 Equipment for erection, dismantling and maintenance . 110
6.4.7 Penstock and other water passages .110
6.4.8 Consequences of changes in plant specific hydraulic energy (head).111
7 Hydraulic design and performance testing options .111
7.1 General .111
7.2 Computational hydraulic design. 112
7.2.1 General .112
7.2.2 The role of CFD.113
7.2.3 The process of a CFD cycle.113
7.2.4 The accuracy of CFD results .114
7.2.5 How to use CFD for rehabilitation .115
7.2.6 CFD versus model tests .115
7.3 Model tests.116
7.3.1 General .116
7.3.2 Model test
...