BS EN IEC 63461:2024
$215.11
Pelton hydraulic turbines. Model acceptance tests
| Published By | Publication Date | Number of Pages |
| BSI | 2024 | 176 |
IEC 63461:2024 applies to laboratory model tests of any type of Pelton hydraulic turbine with unit power greater than 5 MW. It contains the rules governing test conduct and provides measures to be taken if any phase of the tests is disputed. The main objectives of this document are: – to define the terms and quantities used; – to specify methods of testing and of measuring the quantities involved, in order to ascertain the hydraulic performance of the model; – to specify the methods of computation of results and of comparison with guarantees; – to determine if the contract guarantees that fall within the scope of this document have been fulfilled; – and to define the extent, content and structure of the final report. Full application of the procedures herein described is not generally justified for machines with smaller power. Nevertheless, this document can be used for such machines by agreement between the purchaser and the supplier.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | undefined |
| 5 | Annex ZA (normative)Normative references to international publicationswith their corresponding European publications |
| 6 | English CONTENTS |
| 13 | FOREWORD |
| 15 | 1 Scope |
| 16 | 2 Normative references 3 Terms, definitions, symbols and units 3.1 General 3.2 Terms and definitions |
| 18 | 3.3 Units 3.4 Terms, definitions, symbols and units 3.4.1 List by topics |
| 19 | 3.4.2 Subscripts and symbols |
| 20 | 3.4.3 Geometry Figures Figure 1 – Schematic representation of a Pelton machine |
| 21 | 3.4.4 Physical quantities and properties Figure 2 – Reference diameter and bucket width |
| 22 | 3.4.5 Discharge, velocity and speed 3.4.6 Pressure |
| 23 | 3.4.7 Specific energy 3.4.8 Height and head Figure 3 – Reference level of a Pelton machine |
| 24 | 3.4.9 Power and torque |
| 25 | Figure 4 – Flux diagram for power |
| 26 | 3.4.10 Efficiency 3.4.11 Fluctuating quantities |
| 28 | Figure 5 – Illustration of some definitions related to oscillating quantities |
| 29 | 3.4.12 Fluid dynamics and scaling 3.4.13 Dimensionless terms and definitions |
| 30 | 3.4.14 Additional performance data 4 Physical properties 4.1 General 4.2 Acceleration due to gravity |
| 31 | 4.3 Physical properties of water 4.3.1 Density of water Figure 6 – Acceleration due to gravity g (m s-2) |
| 33 | Tables Table 1 – Coefficients of the Herbst and Roegener formula |
| 34 | 4.3.2 Kinematic viscosity 4.3.3 Vapour pressure Figure 7 – Density of distilled water ρwd (kg m−3) |
| 35 | 4.4 Physical conditions of atmosphere 4.4.1 Density of dry air 4.4.2 Ambient pressure 4.5 Density of mercury |
| 36 | 5 Requirements of tests 5.1 Requirement of test installation and model 5.1.1 Choice of laboratory 5.1.2 Test installation |
| 37 | 5.1.3 Model requirements |
| 38 | Figure 8 – Example for homology limits for wetted parts of a vertical Pelton turbine Figure 9 – Example for homology limit for wetted parts of a horizontal Pelton turbine |
| 39 | 5.2 Dimensional check of model and prototype 5.2.1 General |
| 40 | 5.2.2 Explanation of terms used for model and prototype 5.2.3 Purpose of dimensional checks 5.2.4 General rules |
| 41 | 5.2.5 Procedure Figure 10 – Procedure for dimensional checks, comparison of results “steel to steel”and application of tolerances for model and prototype |
| 42 | 5.2.6 Methods |
| 43 | Figure 11 – Pelton turbine: example of dimensions to be checked on the distributor and the housing of vertical and horizontal shaft machines |
| 44 | Figure 12 – Pelton turbine: example of dimensions to be checked on the buckets and nozzles |
| 45 | 5.2.7 Accuracy of measurements 5.2.8 Dimensions of model and prototype to be checked |
| 47 | 5.2.9 Permissible maximum deviations in geometrical similarity between prototype and model Table 2 – Permissible maximum deviations |
| 48 | 5.2.10 Surface waviness and roughness |
| 49 | Figure 13 – Definition of waviness and surface roughness |
| 50 | 5.3 Test procedures 5.3.1 Organization of tests Table 3 – Maximum recommended prototype surface roughness Ra |
| 52 | 5.3.2 Inspections and calibrations |
| 54 | 5.3.3 Execution of tests |
| 58 | 5.3.4 Faults and repetition of tests |
| 59 | 5.3.5 Preliminary test report 5.3.6 Final test report 6 Data acquisition 6.1 Data acquisition and data processing 6.1.1 General |
| 60 | 6.1.2 General requirements 6.1.3 Data acquisition |
| 61 | Figure 14 – Time multiplexing data acquisition system Figure 15 – Bus operated data acquisition system |
| 62 | 6.1.4 Component requirements |
| 63 | Figure 16 – Time delay Figure 17 – Typical low-pass filter attenuation characteristics |
| 65 | 6.1.5 Check of the data acquisition system |
| 66 | Figure 18 – Different measurement chains and their recommended checkpoints |
| 67 | 6.2 Data acquisition and processing for measurement of fluctuating quantities 6.2.1 General |
| 68 | 6.2.2 Data acquisition Figure 19 – Typical data acquisition system |
| 69 | Figure 20 – Frequency response of analogue anti-aliasing filter |
| 70 | 6.2.3 Data processing |
| 71 | 6.3 Error analysis 6.3.1 Definitions |
| 73 | 6.3.2 Determination of uncertainties in model tests |
| 74 | Figure 21 – Example of calibration curve |
| 75 | Table 4 – Summary of errors that determine total measurement uncertainty |
| 78 | 7 Methods of measurement 7.1 Discharge measurement 7.1.1 General |
| 79 | 7.1.2 Choice of the method of measurement 7.1.3 Accuracy of measurement |
| 80 | 7.1.4 Primary methods |
| 81 | 7.1.5 Secondary methods |
| 84 | 7.2 Pressure measurement 7.2.1 General 7.2.2 Choice of pressure-measuring section |
| 85 | 7.2.3 Pressure taps and connecting lines |
| 86 | Figure 22 – Examples of pressure taps |
| 87 | Figure 23 – Types of pressure manifolds |
| 88 | 7.2.4 Apparatus for pressure measurement |
| 89 | Table 5 – Examples of experimental setup of liquid column manometers |
| 92 | Figure 24 – Dead weight manometer with compensation by pressure or force transducer (example of experimental set-up) |
| 93 | Figure 25 – Pressure weighbeam (example of experimental set-up) |
| 94 | 7.2.5 Calibration of pressure measurement apparatus |
| 95 | 7.2.6 Vacuum measurements 7.2.7 Uncertainty in pressure measurements 7.3 Free water level measurement (see also ISO 4373) 7.3.1 General |
| 96 | 7.3.2 Choice of water level measuring sections 7.3.3 Number of measuring points in a measuring section 7.3.4 Measuring methods Figure 26 – Stilling well |
| 97 | 7.3.5 Uncertainty in free water level measurement Figure 27 – Point and hook gauges |
| 98 | 7.4 Shaft torque measurement 7.4.1 General 7.4.2 Methods of torque measurement |
| 99 | 7.4.3 Methods of absorbing/generating power 7.4.4 Layout of arrangement |
| 100 | Figure 28 – Balance arrangement Table 6 – Nomenclature for Figure 28 to Figure 33 |
| 101 | Figure 29 – Balance arrangement with two separate frames Figure 30 – Arrangement with machine bearings and seals not in balance |
| 102 | Figure 31 – Arrangement using a torquemeter Figure 32 – Arrangement using a torquemeter with machine bearings and seals in balance |
| 103 | 7.4.5 Checking of system Figure 33 – Arrangement using a torquemeter with machine bearings and seals not in balance |
| 104 | 7.4.6 Calibration 7.4.7 Uncertainty in torque measurement (at a confidence level of 95 %) |
| 106 | 7.5 Rotational speed measurement 7.5.1 General 7.5.2 Methods of speed measurement 7.5.3 Checking 7.5.4 Uncertainty of measurement 8 Test execution and results 8.1 General |
| 107 | 8.2 Determination of E 8.2.1 General 8.2.2 Determination of the specific hydraulic energy E |
| 109 | Figure 34 – Example showing main elevations, heights and reference levels of the test rig and model machine |
| 110 | 8.2.3 Simplified formulae for E |
| 112 | 8.3 Determination of power and efficiency 8.3.1 Hydraulic power Figure 35 – Pelton turbines with horizontal axis: determination of specific hydraulic energy of the machine |
| 113 | 8.3.2 Mechanical power 8.3.3 Hydraulic efficiency |
| 114 | 8.4 Hydraulic similitude 8.4.1 Theoretical basic requirements and similitude numbers 8.4.2 Conditions for hydraulic similitude as used in this document Table 7 – Similitude numbers |
| 115 | 8.4.3 Similitude requirements for various types of model tests 8.4.4 Reynolds similitude 8.4.5 Froude similitude 8.4.6 Other similitude conditions – Weber number Table 8 – Similitude requirements for various types of model tests |
| 116 | 8.5 Test conditions 8.5.1 Determination of test conditions 8.5.2 Minimum values for model size and test conditions to be fulfilled |
| 117 | 8.5.3 Stability and fluctuations during measurements 8.5.4 Adjustment of the operating point 8.6 Computation and presentation of test results 8.6.1 General Table 9 – Minimum values for model size and test parameters |
| 118 | 8.6.2 Power, discharge and efficiency in the guarantee range Figure 36 – Pelton model turbine: performance hill diagram (example for a six-nozzle machine) Table 10 – Variables defining the operating point of a machine |
| 120 | Figure 37 – Three-dimensional surface of hydraulic efficiency and curves of performance at EnD constant |
| 122 | 8.6.3 Computation of steady-state runaway speed and discharge Figure 38 – Runaway curves for a six-nozzle Pelton turbine Figure 39 – Runaway speed determined by extrapolation |
| 123 | 9 Nature and extent of guarantees related to hydraulic performance 9.1 General 9.1.1 Design data and coordination |
| 124 | 9.1.2 Definition of the hydraulic performance guarantees 9.1.3 Guarantees of correlated quantities 9.1.4 Form of guarantees |
| 125 | 9.2 Main hydraulic performance guarantees verifiable by model test 9.2.1 Guaranteed quantities for any machine 9.2.2 Specific application 9.3 Guarantees not verifiable by model test 9.3.1 Guarantees on cavitation erosion 9.3.2 Guarantees on maximum momentary overspeed and maximum momentary pressure rise |
| 126 | 9.3.3 Guarantees covering noise and vibration 9.3.4 Measurements not covered by this document 9.4 Comparison with guarantees 9.4.1 General 9.4.2 Interpolation curve and total uncertainty bandwidth |
| 127 | 9.4.3 Power, discharge and/or specific hydraulic energy and efficiency in the guarantee range Figure 40 – Measured hydraulic efficiency compared to guarantee point |
| 128 | 9.4.4 Prototype mechanical losses 9.4.5 Runaway speed and discharge Figure 41 – Comparison between guarantees and measurements |
| 129 | 9.4.6 Penalty and premium 10 Additional performance data – Methods of measurement and results 10.1 Additional data measurement 10.1.1 General Figure 42 – Pelton turbine runaway speed and discharge curves: comparison between guarantees and measurements |
| 130 | 10.1.2 Test conditions and test procedures 10.1.3 Uncertainty in measurements |
| 131 | 10.1.4 Model to prototype conversion 10.2 Hydraulic loads on control components 10.2.1 General |
| 132 | 10.2.2 Pelton needle force and deflector torque |
| 134 | Figure 43 – Pelton needle force factor as a function of relative needle stroke |
| 135 | 10.3 Influence of tail water level 10.4 Testing in an extended operating range 10.4.1 General 10.4.2 Scope of tests |
| 136 | 10.4.3 Methods of testing in the extended operating range |
| 137 | 10.5 Differential pressure measurement in view of prototype index test 10.5.1 General 10.5.2 Purpose of test 10.5.3 Execution of test |
| 138 | 10.5.4 Analysis of test results Figure 44 – Example of pressure tap location for index test Figure 45 – Example of graphical representation of index test data |
| 139 | 10.5.5 Transposition to prototype conditions 10.5.6 Uncertainty 10.6 Nozzle flow discharge calibration in view of prototype index test |
| 140 | Annexes Annex A (informative) Dimensionless terms |
| 141 | Table A.1 – Dimensionless terms |
| 142 | Annex B (normative) Physical properties, data Table B.1 – Acceleration due to gravity g (m·s−2) |
| 143 | Table B.2 – Density of distilled water ρwd (kg·m−3) |
| 145 | Table B.3 – Kinematic viscosity of distilled water ν (m2·s−1) |
| 146 | Table B.4 – Vapour pressure of distilled water pva (Pa) |
| 147 | Table B.5 – Density of dry air ρa (kg·m−3) |
| 148 | Table B.6 – Ambient pressure pamb (Pa) |
| 149 | Table B.7 – Density of mercury ρHg (kg·m−3) |
| 150 | Annex C (informative) Summarized test and calculation procedure C.1 General C.2 Agreements to be reached prior to testing |
| 151 | C.3 Model, test facility and instrumentation C.3.1 Model manufacture and dimensional checks C.3.2 Test facility instrumentation and data acquisition system C.4 Tests and calculation of the model values C.4.1 Test types C.4.2 Measurement of the main quantities during the test |
| 152 | C.4.3 Uncertainty of the measured quantities C.4.4 Calculation of the quantities related to the main hydraulic performance C.4.5 Calculation of the dimensionless factors or coefficients and of the Thoma number C.5 Calculation of prototype quantities |
| 153 | C.6 Plotting of model or prototype results C.7 Comparison with the guarantees C.8 Final protocol C.9 Final test report |
| 154 | Annex D (normative) Computation of the prototype runaway characteristics taking into account friction and windage losses of the unit Figure D.1 – Determination of the maximum runaway speed of the prototype taking into account the friction and windage losses of the unit |
| 155 | Annex E (informative) Example of determination of the best smooth curve: method of separate segments E.1 General E.2 Principle of the method |
| 156 | Figure E.1 – Principle of the method of separate segments Figure E.2 – Example of determination of intervals |
| 157 | E.3 Choice of the minimum width of the intervals E.4 Determination of the intervals |
| 158 | Annex F (informative) Examples of analysis of sources of error and uncertainty evaluation F.1 General F.2 Example of analysis of sources of error and of uncertainty evaluation in the measurement of a physical quantity F.2.1 General |
| 159 | F.2.2 Errors arising during calibration |
| 160 | F.2.3 Errors arising during the tests |
| 161 | F.3 Example of calculation of uncertainty due to systematic errors in the determination of the specific hydraulic energy, mechanical runner power and hydraulic efficiency F.3.1 General F.3.2 Discharge F.3.3 Pressure F.3.4 Specific hydraulic energy |
| 162 | F.3.5 Power |
| 163 | F.3.6 Hydraulic efficiency |
| 164 | Annex G (normative) The scale effect on hydraulic efficiency for Pelton turbines G.1 General G.2 Similarity considerations |
| 165 | Figure G.1 – Influence of Froude number Table G.1 – Numerical data for surface tension σ* |
| 166 | G.3 Transposition formula Figure G.2 – Influence of Weber number Figure G.3 – Influence of Reynolds number |
| 167 | Annex H (normative) Analysis of random errors for a test at constant operating conditions H.1 General H.2 Standard deviation |
| 168 | H.3 Confidence levels H.4 Student’s t distribution Table H.1 – Confidence levels |
| 169 | H.5 Maximum permissible value of uncertainty due to random errors Table H.2 – Values of Student’s t |
| 170 | H.6 Example of calculation Table H.3 – Computation of the estimated standard deviation and the uncertainty for eight observations |
| 171 | Annex I (informative) Flux diagram of specific hydraulic energy and power Figure I.1 – Turbine |
| 173 | Bibliography |
