EN 60953-1:1995

SLOVENSKI STANDARD
01-junij-2000
Rules for steam turbine thermal acceptance tests - Part 1: Method A - High
accuracy for large condensing steam turbines
Rules for steam turbine thermal acceptance tests -- Part 1: Method A - High accuracy for
large condensing steam turbines
Regeln für thermische Abnahmeprüfungen für Dampfturbinen -- Teil 1: Methode A -
Hohe Präzision für große kondensierende Dampfturbinen
Règles pour les essais thermiques de réception des turbines à vapeur -- Partie 1:
Méthode A - Haute précision pour les turbines à vapeur à condensation de grande
puissance
Ta slovenski standard je istoveten z: EN 60953-1:1995
ICS:
27.040 Plinske in parne turbine. Gas and steam turbines.
Parni stroji Steam engines
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEI
NORME
IEC
INTERNATIONALE
953-1
INTERNATIONAL
Première édition
First edition
STANDARD 1990-12
Règles pour les essais thermiques de
réception des turbines à vapeur
Première partie:
Méthode A — Haute précision, pour turbines à
vapeur à condensation de grande puissance
Rules for steam turbine thermal acceptance
tests
Part 1:
Method A — High accuracy for large condensing
steam turbines
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953-1 © IEC - 3 -
CONTENTS
Page
FOREWORD 9
PREFACE
I 1
INTRODUCTION
Clause
1. Scope and object
1.1 Scope
1.2 Object
1.3 Matters to be considered in the contract
2. Units, symbols, terms and definitions
2.1 General
2.2 Symbols, units
2.3 Subscripts, superscripts and definitions 21
2.4 Definition of guarantee values and test results
2.4.1 Thermal efficiency 27
2.4.2 Heat rate 29
2.4.3 Thermodynamic efficiency 29
2.4.4 Steam rate 29
2.4.5 Main steam flow capacity 3 I
2.4.6 Maximum power output 31
3. Guiding principles
3.1 Advance planning for test 31
3.2 Preparatory agreements and arrangements for tests
3.3 Planning of the tests 35
3.3.1 Time for acceptance tests
3.3.2 Direction of acceptance tests
3.3.3 Cost of acceptance tests
3.4 Preparation of the tests
3.4.1 Condition of the plant
3.4.2 Condition of the steam turbine 37
3.4.3 Condition of the condenser 37
3.4.4 Isolation of the cycle 37
3.4.5 Checks for leakage of condenser and feedwater heaters
3.4.6 Cleanliness of the steam strainers
3.4.7 Checking of the test measuring equipment
3.5 Comparison measurements 43
3.6 Settings for tests
3.6.1 Load settings
3.6.2 Special settings
3.7 Preliminary tests 45
3.8 Acceptance tests
3.8.1 Constancy of test conditions
3.8.2 Maximum deviation and fluctuation in test conditions
47 3.8.3 Duration of test runs and frequency of readings
49 3.8.4 Reading of integrating measuring instruments
3.8.5 Alternative methods
3.8.6 Recording of tests
3.8.7 Additional measurements
3.8.8 Preliminary calculations
3.8.9 Consistency of tests
3.9 Repetition of acceptance tests
51 4. Measuring techniques and measuring instruments
4.1 General
4.1.1 Measuring instruments
4.1.2 Measuring uncertainty
4.1.3 Calibration of instruments
4.1.4 Alternative instrumentation
4.1.5 Mercury in instrumentation
4.2 Measurement of power
63 4.2.1 Determination of mechanical turbine output
4.2.2 Measurement of boiler feed pump power
69 4.2.3 Determination of electrical power of a turbine generator

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953-1 © IEC
Clause Page
4.2.4 Measurement of electrical power 69
4.2.5 Electrical instrument connections
4.2.6 71
Electrical instruments
4.2.7 Instrument transformers
4.2.8 Comparison measurement and recalibration of instruments and transformers
4.3 Flow measurements
4.3.1 Determination of flows to be measured
4.3.2 73
Measurement of primary water flow
4.3.3 Installation and location of differential pressure devices
4.3.4 Differential pressure measurements 79
4.3.5
Water flow fluctuation 83
4.3.6 Secondary flow measurements 83
4.3.7 Occasional secondary flows
4.3.8 Density of water and steam
91 4.3.9 Determination of cooling water flow of condenser
4.4 Pressure measurements (excluding condensing turbine exhaust pressure)
4.4.1 Pressures to be measured
4.4.2 Instruments
4.4.3 Pressure tapping holes and connecting lines
4.4.4 Shut-off valves 97
4.4.5 Calibration of pressure measuring devices 97
4.4.6 Atmospheric pressure 97
4.4.7 Correction of readings
101 4.5 Condensing turbine exhaust pressure measurement
4.5.1 General
4.5.2 Plane of measurement
4.5.3
Pressure taps
4.5.4 Manifolds
4.5.5 Connecting lines
4.5.6 Instruments
4.5.7 Tightness of measuring system
4.5.8
Calibration
4.5.9 Correction of readings
4.6 Temperature measurement
4.6.1 Points of temperature measurement
4.6.2 Instruments
109 4.6.3 Main temperature measurements
4.6.4 Feed train temperature measurements (including bled steam)
I11
Condenser cooling water temperature measurement 4.6.5
4.6.6 Accuracy of temperature measuring equipment
I11
4.6.7 Thermometer wells
Precautions to be observed in the measurement of temperature 4.6.8
4.7 Steam quality measurement
4.7.1 General
4.7.2 Tracer technique
4.7.3 Condensing method
4.7.4
Constant rate injection method
4.7.5 Extraction enthalpy determined by constant rate injection method
4.7.6 Tracer and their use
4.8 Time measurement
4.9 Speed measurement
5. Evaluation of tests
5.1 Preparation of evaluation
5.2 Computation of results
5.2.1 Calculation of average values of instrument readings
5.2.2 Correction and conversion of averaged readings
5.2.3 Checking of measured data
5.2.4 Thermodynamic properties of steam and water
5.2.5 Calculation of test results
6. Correction of test results and comparison with guarantee
133 6.1 Guarantee values and guarantee conditions
6.2 Correction of initial steam flow capacity
6.3 Correction of maximum output
Correction of thermal and thermodynamic efficiency 135
6.4
6.5 Definition and application of correction values
6.6 Correction methods
6.6.1 Correction by heat balance calculation 139

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Page
Clause
6.6.2 Correction by use of correction curves prepared by the manufacturer 141
6.6.3 Tests to determine correction values
6.7 Variables to be considered in the correction
6.7.1 Turbines with regenerative feed-water heating
6.8 Guarantee comparison
6.8.1 Guarantee comparison with locus curve
6.8.2 Guarantee comparison with guarantee point
6.8.3 Guarantee comparison for turbines with throttle regulation
APPENDIX A — Feedwater heater leakage and condenser leakage tests
APPENDIX
B — Throat tap nozzle
161 APPENDIX C — The use of flow straighteners in fluid flow measurements

953-1 © IEC — 9 —
INTERNATIONAL ELECTROTECHNICAL COMMISSION
RULES FOR STEAM TURBINE THERMAL ACCEPTANCE TESTS
Part 1: Method A — High accuracy for large condensing steam turbines
FOREWORD
The formal decisions or agreements of the IEC on technical matters, prepared by Technical Committees on which all the
1)
National Committees having a special interest therein are represented, express, as nearly as possible, an international
consensus of opinion on the subjects dealt with.
They have the form of recommendations for international use and they are accepted by the National Committees in that
2)
sense.
In order to promote international unification, the IEC expresses the wish that all National Committees should adopt the
3)
text of the IEC recommendation for their national rules in so far as national conditions will permit. Any divergence
between the IEC recommendation and the corresponding national rules should, as far as possible, be clearly indicated in
the latter.
PREFACE
This standard has been prepared by IEC Technical Committee No. 5: Steam turbines.
The text of this standard is based on the following documents:
Report on Voting
Six Months' Rule
5(CO)27
5(CO)23
Full information on the voting for the approval of this standard can be found in the Voting
Report indicated in the above table.
The following IEC publication is quoted in this standard:
Publication No.34-2(1972): Rotating electrical machines. Part 2: Methods for determining losses and efficiency of
rotating electrical machinery from tests (excluding machines for traction vehicles).
Other Publication quoted:
flow by means of orifice plates, nozzles and Venturi tubes inserted in
ISO Standard 5167(1980): Measurement of fluid
circular cross-section conduits running full.

I 1 —
—
953-1 © IEC
RULES FOR STEAM TURBINE THERMAL ACCEPTANCE TESTS
Part 1: Method A — High accuracy for large condensing steam turbines
INTRODUCTION
The rapid development of measuring techniques, the increasing capacity of steam turbines and
the introduction of nuclear power plants necessitated a revision of IEC Publication 46 (1962)
regarding acceptance tests.
Since all the needs of the power industry in the different parts of the world could not be satisfied
by one single publication, the complete standard is divided into two parts, describing two different
approaches for conducting and evaluating thermal acceptance tests of steam turbines and which
can be used separately:
a)
Method A, which is Part 1 of the standard (IEC 953-1), deals with thermal acceptance tests with
high accuracy for large condensing steam turbines.
b) Method B, which is Part 2 of the standard (IEC 953-2), deals with thermal acceptance tests with a
wide range of accuracy for various types and sizes of steam turbines.
1) Basic philosophy and figures on uncertainty
Pa
rt 1 provides for very accurate testing of steam turbines to obtain the level of performance with
minimum measuring uncertainty. The operating conditions during the test are stringent and
compulsory.
Method A is based on the exclusive use of the most accurate calibrated instrumentation and the
best measuring procedures currently available. The uncertainty of the test result is always suf-
ficiently small that it normally need not be taken into acount in the comparison between test result
and guarantee value. This uncertainty will not be larger than about 0.3% for a fossil fired unit and
0.4% for a nuclear unit.
The cost for instrumentation and the efforts for preparing and conducting the tests will generally
be justified economically for large and/or prototype units.
Method B provides for acceptance tests of steam turbines of various types and capacities with
appropriate measuring uncertainty. Instrumentation and measuring procedures have to be chosen
accordingly from a scope specified in the standard which is centred mainly on standardized
instrumentation and procedures, but may extend eventually up to very high accuracy provisions
requiring calibration. The resulting measuring uncertainty of the test result is then determined by
calculating methods presented in the standard and normally, if not stated otherwise in the contract,
taken into account in the comparison between test result and guarantee value. The total cost of an
acceptance test can therefore be maintained in relationship with the economic value of the
guarantee values to be ascertained.
The specifications of the operating conditions during the test are somewhat more flexible in this
method; furthermore, procedures are recommended for treating cases where these specifications
cannot be met.
IEC
953-1 © — 13 —
When good-standardized instrumentation and procedures are applied in a test, the measuring
uncertainty of the result will usually amount to 0.9% to 1.2% for a large fossil fuel fired condensing
unit, to 1.1 % to 1.4% for a nuclear unit and to 1.5% to 2.5 % for back pressure, extraction and small
condensing turbines. It is possible to reduce these values by additional improvement in instrumen-
tation, primarily by additional measurements of primary mass flows and/or calibration of
ow.
measuring devices for primary mass fl
2) B
Main difference between Methods A and
In Method A, much more detailed information concerning the preparation and conduct of the
tests and the measuring techniques are contained for guidance of the parties to the test than in
Method B. In Method B, the detailed treatment of these objectives is left somewhat more to the
discretion and decisions of the participants and necessitates sufficient experience and expertise on
their part.
3) Guiding principles
The requirements concerning the preparation and conditions of the test and especially such
conditions of the test as duration, deviations and constancy of test conditions and acceptable
differences between double measurements are more stringent in Method A.
The test should be conducted preferably within eight weeks after the beginning of the operation.
It is the intent during this period to minimize performance deterioration and risk of damage to the
turbine.
Preliminary tests including enthalpy drop tes
...