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

IEC 62256:2017 covers turbines, storage pumps and pump-turbines of all sizes and of the following types: Francis; Kaplan; propeller; Pelton (turbines only) and bulb turbines.
This document also identifies without detailed discussion, other powerhouse equipment that could affect or be affected by a turbine, storage pump, or pump-turbine rehabilitation. The object of this document is to assist in identifying, evaluating and executing rehabilitation and performance improvement projects for hydraulic turbines, storage pumps and pump-turbines. This document can be used by owners, consultants, and suppliers to define: needs and economics for rehabilitation and performance improvement; scope of work; specifications and evaluation of results. This document 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; and identification of the points to be addressed in the decision processes. This document is not intended to be a detailed engineering manual nor a maintenance document. This second edition cancels and replaces the first edition published in 2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: Tables 2 to 23 modified, completed and moved to Annex A; 7.3.2: subclauses moved with text changes; new subclauses on temperature, noise, galvanic corrosion, galling and replacement of components without assessment; 7.3.3: complete new subclause on residual life; Tables 29 to 32 moved to Annex C; New Annex B with assessment examples.
Key words: Turbines, Storage pump, Pump turbines, Rehabilitation, Performance.

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

Spécifie comment préparer les spécifications particulières pour les transformateurs de puissance pour alimentations à découpage. Comprend une spécification particulière  cadre, qui montre la présentation et indique les essais appropriés  à considérer pour ce type de composant.

General Information

Status
Published
Publication Date
29-May-2017
Technical Committee
Drafting Committee
Current Stage
PPUB - Publication issued
Start Date
26-May-2017
Completion Date
30-May-2017
Ref Project

Relations

Buy Standard

Standard
IEC 62256:2017 - Hydraulic turbines, storage pumps and pump-turbines - Rehabilitation and performance improvement Released:5/30/2017 Isbn:9782832243404
English language
158 pages
sale 15% off
Preview
sale 15% off
Preview
Standard
IEC 62256:2017 RLV - Hydraulic turbines, storage pumps and pump-turbines - Rehabilitation and performance improvement Released:5/30/2017 Isbn:9782832244333
English language
488 pages
sale 15% off
Preview
sale 15% off
Preview
Standard
IEC 62256:2017 - Hydraulic turbines, storage pumps and pump-turbines - Rehabilitation and performance improvement
English and French language
326 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (Sample)


IEC 62256 ®
Edition 2.0 2017-05
INTERNATIONAL
STANDARD
colour
inside
Hydraulic turbines, storage pumps and pump-turbines – Rehabilitation and
performance improvement
All rights reserved. Unless otherwise 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 IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
IEC 62256 ®
Edition 2.0 2017-05
INTERNATIONAL
STANDARD
colour
inside
Hydraulic turbines, storage pumps and pump-turbines – Rehabilitation and

performance improvement
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.140 ISBN 978-2-8322-4340-4

– 2 – IEC 62256:2017 © IEC 2017
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms, definitions and nomenclature . 10
4 Reasons for rehabilitating . 12
4.1 General . 12
4.2 Reliability and availability increase. 14
4.3 Life extension and performance restoration . 14
4.4 Performance improvement . 14
4.5 Plant safety improvement . 14
4.6 Environmental, social and regulatory issues . 15
4.7 Maintenance and operating cost reduction . 15
4.8 Other considerations . 15
5 Phases of a rehabilitation project . 15
5.1 General . 15
5.2 Decision on organization . 17
5.2.1 General . 17
5.2.2 Expertise required . 17
5.2.3 Contract arrangement . 17
5.3 Level of assessment and determination of scope . 18
5.3.1 General . 18
5.3.2 Feasibility study – Stage 1 . 19
5.3.3 Feasibility study – Stage 2 . 19
5.3.4 Detailed study. 19
5.4 Contractual issues . 23
5.4.1 General . 23
5.4.2 Specification requirements . 24
5.4.3 Tendering documents and evaluation of tenders . 24
5.4.4 Contract award(s) . 25
5.5 Execution of project . 25
5.5.1 Model test activities . 25
5.5.2 Design, construction, installation and testing . 25
5.6 Evaluation of results and compliance with guarantees . 26
5.6.1 General . 26
5.6.2 Turbine performance evaluation. 26
5.6.3 Generator performance evaluation . 27
5.6.4 Penalties and/or bonuses assessment . 27
6 Scheduling, cost analysis and risk analysis . 27
6.1 Scheduling . 27
6.1.1 General . 27
6.1.2 Scheduling – Assessment, feasibility and detailed study phases . 28
6.1.3 Evaluating the scheduling component of alternatives . 28
6.1.4 Scheduling specification and tendering phase . 29
6.1.5 Scheduling project execution phases . 29
6.2 Economic and financial analyses . 29

6.2.1 General . 29
6.2.2 Benefit-cost analysis . 30
6.2.3 Identification of anticipated benefits . 31
6.2.4 Identification of anticipated costs and benefits . 32
6.2.5 Sensitivity analysis . 33
6.2.6 Conclusions . 34
6.3 Risk analysis. 34
6.3.1 General . 34
6.3.2 Non-achievement of performance risk . 34
6.3.3 Risk of continued operation without rehabilitation . 35
6.3.4 Extension of outage risk . 35
6.3.5 Financial risks . 35
6.3.6 Project scope risk . 36
6.3.7 Other risks . 36
7 Assessment and determination of scope of the work . 37
7.1 General . 37
7.2 Assessment of the site . 37
7.2.1 Hydrology . 37
7.2.2 Actual energy production . 38
7.2.3 Environmental, social and regulatory issues . 38
7.3 The assessment of the turbine . 39
7.3.1 General . 39
7.3.2 Turbine integrity assessment . 39
7.3.3 Residual life. 52
7.3.4 Turbine performance assessment . 61
7.4 The assessment of related equipment . 83
7.4.1 General . 83
7.4.2 Generator and thrust bearing . 84
7.4.3 Turbine governor . 84
7.4.4 Turbine inlet and outlet valves, pressure relief valve . 85
7.4.5 Auxiliary equipment . 85
7.4.6 Equipment for erection, dismantling and maintenance . 86
7.4.7 Penstock and other water passages . 86
7.4.8 Consequences of changes in plant specific hydraulic energy (head) . 86
7.4.9 Grid integration . 87
8 Hydraulic design and performance testing options . 87
8.1 General . 87
8.2 Computational hydraulic design . 88
8.2.1 General . 88
8.2.2 The role of CFD . 88
8.2.3 The process of a CFD cycle . 89
8.2.4 The accuracy of CFD results . 89
8.2.5 How to use CFD for rehabilitation . 90
8.2.6 CFD versus model tests . 91
8.3 Model tests . 91
8.3.1 General . 91
8.3.2 Model test similitude . 92
8.3.3 Model test content . 93
8.3.4 Model test application . 93

– 4 – IEC 62256:20
...


IEC 62256 ®
Edition 2.0 2017-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Hydraulic turbines, storage pumps and pump-turbines – Rehabilitation and
performance improvement
All rights reserved. Unless otherwise 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 IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
IEC 62256 ®
Edition 2.0 2017-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Hydraulic turbines, storage pumps and pump-turbines – Rehabilitation and

performance improvement
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.140 ISBN 978-2-8322-4433-3

– 2 – IEC 62256:2017 RLV © IEC 2017
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms, definitions and nomenclature . 10
4 Reasons for rehabilitating . 12
4.1 General . 12
4.2 Reliability and availability increase. 14
4.3 Life extension and performance restoration . 14
4.4 Performance improvement . 14
4.5 Plant safety improvement . 14
4.6 Environmental, social and regulatory issues . 15
4.7 Maintenance and operating cost reduction . 15
4.8 Other considerations . 15
5 Phases of a rehabilitation project . 15
5.1 General . 15
5.2 Decision on organization . 17
5.2.1 General . 17
5.2.2 Expertise required . 17
5.2.3 Contract arrangement . 17
5.3 Level of assessment and determination of scope . 18
5.3.1 General . 18
5.3.2 Feasibility study – Stage 1 . 19
5.3.3 Feasibility study – Stage 2 . 19
5.3.4 Detailed study. 19
5.4 Contractual issues . 23
5.4.1 General . 23
5.4.2 Specification requirements . 24
5.4.3 Tendering documents and evaluation of tenders . 24
5.4.4 Contract award(s) . 25
5.5 Execution of project . 25
5.5.1 Model test activities . 25
5.5.2 Design, construction, installation and testing . 25
5.6 Evaluation of results and compliance with guarantees . 26
5.6.1 General . 26
5.6.2 Turbine performance evaluation. 26
5.6.3 Generator performance evaluation . 27
5.6.4 Penalties and/or bonuses assessment . 27
6 Scheduling, cost analysis and risk analysis . 27
6.1 Scheduling . 27
6.1.1 General . 27
6.1.2 Scheduling – Assessment, feasibility and detailed study phases . 28
6.1.3 Evaluating the scheduling component of alternatives . 28
6.1.4 Scheduling specification and tendering phase . 29
6.1.5 Scheduling project execution phases . 29
6.2 Economic and financial analyses . 29

6.2.1 General . 29
6.2.2 Benefit-cost analysis . 30
6.2.3 Identification of anticipated benefits . 31
6.2.4 Identification of anticipated costs and benefits . 32
6.2.5 Sensitivity analysis . 33
6.2.6 Conclusions . 34
6.3 Risk analysis. 34
6.3.1 General . 34
6.3.2 Non-achievement of performance risk . 34
6.3.3 Risk of continued operation without rehabilitation . 35
6.3.4 Extension of outage risk . 35
6.3.5 Financial risks . 35
6.3.6 Project scope risk . 36
6.3.7 Other risks . 36
7 Assessment and determination of scope of the work . 37
7.1 General . 37
7.2 Assessment of the site . 37
7.2.1 Hydrology . 37
7.2.2 Actual energy production . 38
7.2.3 Environmental, social and regulatory issues . 38
7.3 The assessment of the turbine . 39
7.3.1 General . 39
7.3.2 Turbine integrity assessment . 39
7.3.3 Residual life. 53
7.3.4 Turbine performance assessment . 63
7.4 The assessment of related equipment . 85
7.4.1 General . 85
7.4.2 Generator and thrust bearing . 86
7.4.3 Turbine governor . 87
7.4.4 Turbine inlet and outlet valves, pressure relief valve . 87
7.4.5 Auxiliary equipment . 87
7.4.6 Equipment for erection, dismantling and maintenance . 88
7.4.7 Penstock and other water passages . 88
7.4.8 Consequences of changes in plant specific hydraulic energy (head) . 89
7.4.9 Grid integration . 89
8 Hydraulic design and performance testing options . 89
8.1 General . 89
8.2 Computational hydraulic design . 90
8.2.1 General . 90
8.2.2 The role of CFD . 91
8.2.3 The process of a CFD cycle . 91
8.2.4 The accuracy of CFD results . 92
8.2.5 How to use CFD for rehabilitation . 92
8.2.6 CFD versus model tests . 93
8.3 Model tests . 94
8.3.1 General . 94
8.3.2 Model test similitude . 94
8.3.3 Model test content . 95
8.3.4 Model test application . 96

--------------------
...


IEC 62256 ®
Edition 2.0 2017-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Hydraulic turbines, storage pumps and pump-turbines – Rehabilitation and
performance improvement
Turbines hydrauliques, pompes d'accumulation et pompes-turbines –
Réhabilitation et amélioration des performances

All rights reserved. Unless otherwise 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 IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient 20 000 termes et définitions en anglais
Spécifications techniques, Rapports techniques et autres
et en français, ainsi que les termes équivalents dans 16
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.

Recherche de publications IEC - www.iec.ch/searchpub
Glossaire IEC - std.iec.ch/glossary
65 000 entrées terminologiques électrotechniques, en anglais
La recherche avancée permet de trouver des publications IEC
en utilisant différents critères (numéro de référence, texte, et en français, extraites des articles Termes et Définitions des
comité d’études,…). Elle donne aussi des informations sur les publications IEC parues depuis 2002. Plus certaines entrées
projets et les publications remplacées ou retirées. antérieures extraites des publications des CE 37, 77, 86 et

CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished

Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just
Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur cette
Disponible en ligne et aussi une fois par mois par email. publication ou si vous avez des questions contactez-nous:
csc@iec.ch.
IEC 62256 ®
Edition 2.0 2017-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
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
INTERNATIONALE
ICS 27.140 ISBN 978-2-8322-5201-7

– 2 – IEC 62256:2017 © IEC 2017
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms, definitions and nomenclature . 10
4 Reasons for rehabilitating . 12
4.1 General . 12
4.2 Reliability and availability increase. 13
4.3 Life extension and performance restoration . 13
4.4 Performance improvement . 14
4.5 Plant safety improvement . 14
4.6 Environmental, social and regulatory issues . 14
4.7 Maintenance and operating cost reduction . 15
4.8 Other considerations . 15
5 Phases of a rehabilitation project . 15
5.1 General . 15
5.2 Decision on organization . 17
5.2.1 General . 17
5.2.2 Expertise required . 17
5.2.3 Contract arrangement . 17
5.3 Level of assessment and determination of scope . 18
5.3.1 General . 18
5.3.2 Feasibility study – Stage 1 . 18
5.3.3 Feasibility study – Stage 2 . 19
5.3.4 Detailed study. 19
5.4 Contractual issues . 23
5.4.1 General . 23
5.4.2 Specification requirements . 23
5.4.3 Tendering documents and evaluation of tenders . 24
5.4.4 Contract award(s) . 24
5.5 Execution of project . 24
5.5.1 Model test activities . 24
5.5.2 Design, construction, installation and testing . 25
5.6 Evaluation of results and compliance with guarantees . 25
5.6.1 General . 25
5.6.2 Turbine performance evaluation. 25
5.6.3 Generator performance evaluation . 26
5.6.4 Penalties and/or bonuses assessment . 26
6 Scheduling, cost analysis and risk analysis . 26
6.1 Scheduling . 26
6.1.1 General . 26
6.1.2 Scheduling – Assessment, feasibility and detailed study phases . 27
6.1.3 Evaluating the scheduling component of alternatives . 27
6.1.4 Scheduling specification and tendering phase . 28
6.1.5 Scheduling project execution phases . 28
6.2 Economic and financial analyses . 29

6.2.1 General . 29
6.2.2 Benefit-cost analysis . 29
6.2.3 Identification of anticipated benefits . 30
6.2.4 Identification of anticipated costs and benefits . 31
6.2.5 Sensitivity analysis . 32
6.2.6 Conclusions . 32
6.3 Risk analysis. 32
6.3.1 General . 32
6.3.2 Non-achievement of performance risk . 33
6.3.3 Risk of continued operation without rehabilitation . 33
6.3.4 Extension of outage risk . 34
6.3.5 Financial risks . 34
6.3.6 Project scope risk . 34
6.3.7 Other risks . 35
7 Assessment and determination of scope of the work . 35
7.1 General . 35
7.2 Assessment of the site . 36
7.2.1 Hydrology . 36
7.2.2 Actual energy production . 36
7.2.3 Environmental, social and regulatory issues . 37
7.3 The assessment of the turbine . 37
7.3.1 General . 37
7.3.2 Turbine integrity assessment .
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.