1、 IEC 62256 Edition 2.0 2017-05 INTERNATIONAL STANDARD Hydraulic turbines, storage pumps and pump-turbines Rehabilitation and performance improvement IEC 62256:2017-05(en) colour inside THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2017 IEC, Geneva, Switzerland All rights reserved. Unless otherwi
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10、c If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csciec.ch. IEC 62256 Edition 2.0 2017-05 INTERNATIONAL STANDARD Hydraulic turbines, storage pumps and pump-turbines Rehabilitation and performance improvement INTERNATIO
11、NAL ELECTROTECHNICAL COMMISSION ICS 27.140 ISBN 978-2-8322-4340-4 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. colour inside 2 IEC 62256:2017 IEC 2017 CONTENTS FOREWORD . 7 INTRODUCTION . 9
12、 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 Enviro
13、nmental, 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
14、 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
15、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 eval
16、uation . 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 spe
17、cification and tendering phase . 29 6.1.5 Scheduling project execution phases . 29 6.2 Economic and financial analyses 29 IEC 62256:2017 IEC 2017 3 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 benefi
18、ts . 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.
19、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 i
20、ntegrity 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
21、 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
22、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
23、92 8.3.3 Model test content . 93 8.3.4 Model test application 93 4 IEC 62256:2017 IEC 2017 8.3.5 Model test location 95 8.4 Prototype performance test . 96 8.4.1 General . 96 8.4.2 Prototype performance test accuracy . 97 8.4.3 Prototype performance test types 97 8.4.4 Evaluation of results 98 9 Spe
24、cifications 99 9.1 General . 99 9.2 Reference standards . 99 9.3 Information to be included in the tender documents 100 9.4 Documents to be developed in the course of the project . 101 (informative) Check-list for evaluation of existing turbine . 103 Annex A(informative) Assessment examples . 136 An
25、nex B B.1 General . 136 B.2 Runner (applicable to Francis, Kaplan, propeller and Pelton) 136 B.2.1 Documentation available data . 136 B.2.2 Design review 137 B.2.3 Inspection items 137 B.2.4 Assessment of inspection results . 138 B.2.5 Current condition assessment 140 B.2.6 Scope of work 140 B.3 Sta
26、y ring . 142 B.3.1 Documentation available data . 142 B.3.2 Design review 142 B.3.3 Inspection items 142 B.3.4 Assessment of inspection results . 143 B.3.5 Current condition assessment 143 B.3.6 Scope of work (possible action to be taken) . 144 B.4 Guide vanes . 144 B.4.1 Documentation Available dat
27、a 144 B.4.2 Design review 145 B.4.3 Inspection items 145 B.4.4 Assessment of inspection results . 146 B.4.5 Current condition assessment 147 B.4.6 Scope of work 147 B.5 Real life example: Pelton runner with severe crack 148 B.5.1 Data of the Pelton runner . 148 B.5.2 Fatigue analysis 148 B.5.3 Fract
28、ure-mechanics analysis . 150 B.5.4 Results for the Pelton runner . 150 (informative) Checklist for evaluation of related equipment 152 Annex C Bibliography 156 Figure 1 Flow diagram depicting the logic of the rehabilitation process 16 Figure 2 Critical zones for cracks “A” and “B” in Pelton runner b
29、uckets 51 Figure 3 Bathtub curve . 53 Figure 4 Process of residual life estimation 54 Figure 5 Schematic behaviour for the different stages in the fatigue process . 55 IEC 62256:2017 IEC 2017 5 Figure 6 Start-up and full load strain gauge signal on Francis blade . 60 Figure 7 Relative efficiency ver
30、sus relative output Original and new runners . 63 Figure 8 Relative efficiency versus output Original and new runners Outardes 3 generating station . 64 Figure 9 Efficiency and distribution of losses versus specific speed for Francis turbines (model) in 2005 . 65 Figure 10 Relative efficiency gain f
31、ollowing modification of the blades on the La Grande 3 runner, in Quebec, Canada . 67 Figure 11 Potential efficiency improvement for Francis turbine rehabilitation 71 Figure 12 Potential efficiency improvement for Kaplan turbine rehabilitation 72 Figure 13 Cavitation and corrosion-erosion in Francis
32、 runner . 74 Figure 14 Back side erosion of the entrance into a Pelton bucket . 75 Figure 15 Leading edge cavitation erosion on a Francis pump-turbine caused by extended periods of operation at very low loads 76 Figure 16 Severe particle erosion damage in a Francis runner . 78 Table 1 Expected life
33、of a hydropower plant and its subsystems before major work . 13 Table 2 Typical routine inspections 41 Table 3 Example of a rating system for the inspection results 58 Table 4 Example of a typical list of turbine components for Francis and Kaplan with different weight factors X 1to X 7based on relat
34、ive importance 59 Table 5 Example of rating of a single component assessment including three assessment criteria . 59 Table 6 Francis turbine potential efficiency improvement (%) for runner profile modifications only . 66 Table 7 Potential impact of design and condition of runner seals on Francis tu
35、rbine efficiency with new replacement runner or rehabilitated runner (%) . 69 Table 8 Potential total gain in efficiency from the replacement of a Francis turbine runner including the blade profile improvements, the restoration of surface condition and the reduction of seal losses 69 Table 9 Potenti
36、al additional efficiency improvement by rehabilitation/replacement of other water passage components on a Francis turbine (%) . 70 Table A.1 Assessment of turbine embedded parts Stay ring 103 Table A.2 Assessment of turbine embedded parts Spiral or semi-spiral case 104 Table A.3 Assessment of turbin
37、e embedded parts Discharge ring . 105 Table A.4 Assessment of turbine embedded parts Draft tube 107 Table A.5 Assessment of turbine non-embedded, non-rotating parts Headcover . 109 Table A.6 Assessment of turbine non-embedded, non-rotating parts Intermediate and inner headcovers . 112 Table A.7 Asse
38、ssment of turbine non embedded, non-rotating parts Bottom ring 113 Table A.8 Assessment of turbine non embedded, non-rotating parts Guide vanes . 115 Table A.9 Assessment of turbine non embedded, non-rotating parts Guide vane operating mechanism 117 Table A.10 Assessment of turbine non embedded, non
39、-rotating parts Operating ring 118 Table A.11 Assessment of turbine non embedded, non-rotating parts Servomotors . 119 Table A.12 Assessment of turbine non embedded, non-rotating parts Guide bearings 120 6 IEC 62256:2017 IEC 2017 Table A.13 Assessment of turbine non embedded, non-rotating parts Turb
40、ine shaft seal (mechanical seal or packing box) 122 Table A.14 Assessment of turbine non embedded, non-rotating parts Thrust bearing support . 122 Table A.15 Assessment of turbine non embedded, non-rotating parts Nozzles 123 Table A.16 Assessment of turbine non embedded, non-rotating parts Deflector
41、s and energy dissipation 124 Table A.17 Assessment of turbine rotating parts Runner . 125 Table A.18 Assessment of turbine rotating parts Runner . 128 Table A.19 Assessment of turbine rotating parts Runner . 130 Table A.20 Assessment of turbine rotating parts Turbine shaft 131 Table A.21 Assessment
42、of turbine rotating parts Oil head and oil distribution pipes 132 Table A.22 Assessment of turbine auxiliaries Speed and load regulation system (governor) . 133 Table A.23 Assessment of turbine auxiliaries Turbine aeration system 134 Table A.24 Assessment of turbine auxiliaries Lubrication system (g
43、uide vane mechanism) 135 Table C.1 Assessment of related equipment Governor 152 Table C.2 Assessment of related equipment Generator and thrust bearing 153 Table C.3 Assessment of related equipment Penstock and turbine inlet valves . 154 Table C.4 Assessment of related equipment Civil works 155 Table
44、 C.5 Assessment of related equipment Crane, erection equipment . 155 IEC 62256:2017 IEC 2017 7 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ HYDRAULIC TURBINES, STORAGE PUMPS AND PUMP-TURBINES REHABILITATION AND PERFORMANCE IMPROVEMENT FOREWORD 1) The International Electrotechnical Commission (IEC) is
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