Rules for steam turbine thermal acceptance tests - Part 1: Method A - High accuracy for large condensing steam turbines

Specifies very accurate testing of steam turbines to obtain the level of performance with minimum measuring uncertainty. Defines uniform rules for preparing and carrying out an evaluation of the acceptance tests. Defines also the conditions under which the acceptance tests shall take place. The cost for conducting this test method will generally be justified economically for large and/or proptotype units.

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

Spécifie des essais très précis de turbines à vapeur en vue d'obtenir les valeurs des performances avec le minimum d'incertitude de mesure. Définit les règles de base pour la préparation, l'exécution, le dépouillement et l'interprétation des essais. Définit également les conditions dans lesquelles doivent être effectués les essais. Compte tenu du coût des tests, cette méthode est principalement destinée aux tranches de grandes puissance et/ou à des tranches prototypes Cette publication remplace la CEI 46 (1962).

Rules for steam turbine thermal acceptance tests - Part 1: Method A - High accuracy for large condensing steam turbines

General Information

Status
Published
Publication Date
14-Dec-1995
Technical Committee
Drafting Committee
Parallel Committee
Current Stage
6060 - Document made available
Start Date
15-Dec-1995
Completion Date
15-Dec-1995

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SLOVENSKI STANDARD
SIST EN 60953-1:2000
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
SIST EN 60953-1:2000 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60953-1:2000
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SIST EN 60953-1:2000
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SIST EN 60953-1:2000
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SIST EN 60953-1:2000
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SIST EN 60953-1:2000
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SIST EN 60953-1:2000
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
© CEI 1990 Droits de reproduction réservés — Copyright — all rights reserved

publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in

Aucune partie de cette
aucun procédé any form or by any means, electronic or mechanical, including
utilisée sous quelque forme que ce soit et par
photocopying and microfilm, without permission in writing
électronique ou mécanique. y compris la photocopie et les
from the publisher.
microfilms, sans l'accord écrit de [éditeur
Genève, Suisse

Bureau Central de la Commission Electrotechnique Internationale 3, rue de Varembé

CODE PRIX XC
Commission Electrotechnique Internationale
PRICE CODE
International Electrotechnical Commission
MertcttyuaponHaa 3neccrporexcaweckaa HoMHCCHR
IEC
Pourpnx voir catalogue en vigueur
• •
For puce see current catalogue
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SIST EN 60953-1:2000
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
43
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
45
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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SIST EN 60953-1:2000
— 5 —
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
71
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
75
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
89
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
93
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
101
4.5.1 General
101
4.5.2 Plane of measurement
101
4.5.3
Pressure taps
105
4.5.4 Manifolds
105
4.5.5 Connecting lines
105
4.5.6 Instruments
105
4.5.7 Tightness of measuring system
107
4.5.8
Calibration
107
4.5.9 Correction of readings
107
4.6 Temperature measurement
107
4.6.1 Points of temperature measurement
107
4.6.2 Instruments
109 4.6.3 Main temperature measurements
109
4.6.4 Feed train temperature measurements (including bled steam)
I11
Condenser cooling water temperature measurement 4.6.5
111
4.6.6 Accuracy of temperature measuring equipment
I11
4.6.7 Thermometer wells
111
Precautions to be observed in the measurement of temperature 4.6.8
113
4.7 Steam quality measurement
113
4.7.1 General
113
4.7.2 Tracer technique
115
4.7.3 Condensing method
123
4.7.4
Constant rate injection method
123
4.7.5 Extraction enthalpy determined by constant rate injection method
127
4.7.6 Tracer and their use
129
4.8 Time measurement
129
4.9 Speed measurement
129
5. Evaluation of tests
129
5.1 Preparation of evaluation
131
5.2 Computation of results
131
5.2.1 Calculation of average values of instrument readings
131
5.2.2 Correction and conversion of averaged readings
131
5.2.3 Checking of measured data
133
5.2.4 Thermodynamic properties of steam and water
133
5.2.5 Calculation of test results
133
6. Correction of test results and comparison with guarantee
133 6.1 Guarantee values and guarantee conditions
133
6.2 Correction of initial steam flow capacity
135
6.3 Correction of maximum output
Correction of thermal and thermodynamic efficiency 135
6.4
137
6.5 Definition and application of correction values
139
6.6 Correction methods
6.6.1 Correction by heat balance calculation 139
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SIST EN 60953-1:2000
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953-1 © 1 EC —
Page
Clause
6.6.2 Correction by use of correction curves prepared by the manufacturer 141
143
6.6.3 Tests to determine correction values
143
6.7 Variables to be considered in the correction
143
6.7.1 Turbines with regenerative feed-water heating
145
6.8 Guarantee comparison
147
6.8.1 Guarantee comparison with locus curve
147
6.8.2 Guarantee comparison with guarantee point
147
6.8.3 Guarantee comparison for turbines with throttle regulation
15
APPENDIX A — Feedwater heater leakage and condenser leakage tests
153
APPENDIX
B — Throat tap nozzle
161 APPENDIX C — The use of flow straighteners in fluid flow measurements
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SIST EN 60953-1:2000
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

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

sense.

In order to promote international unification, the IEC expresses the wish that all National Committees should adopt the

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.
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SIST EN 60953-1:2000
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:

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

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.
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SIST EN 60953-1:2000
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 tests should be made during this period to monitor HP

and IP turbine section performance. However, these tests do not provide LP section performance

and for this reason it is imperative to conduct the acceptance tests as soon as practicable.

Whatever the case, when using Method A, if an enthalpy drop test indicates a possible

deterioration of the HP or IP section, or if the plant conditions require that the tests be postponed

more than four months after the initial start, then the acceptance tests should be delayed.

An adjustment of the heat rate test results to start-up enthalpy drop efficiencies or for the effects

of aging is not permitted when using Method A.

If the test has to be postponed, Method A proposes that the test be carried out after the first major

internal inspection; several methods are proposed for establishing the approximate condition of the

turbine prior to the tests.
4) Instruments and methods of measurement
Measurement of electrical power

In addition to the conditions required for the measurement of electric power, which are similar

in both methods, Method A requires a check of the instruments by a comparison measurement

after each test run; the permissible difference between double measurements is limited to 0.15%.

b) Flow measurement

For the measurement of main flows the use of calibrated pressure difference devices is required

in Method A. The application of a device not covered by international standardization, the

throat-tap nozzle, is recommended therein and details of design and application are given.

The calibration of these devices shall be conducted with the upstream and downstream piping

and flow-straightener. Methods for the necessary extrapolation of the discharge coefficient from

the calibration values are given.
flow
In Method B standardized pressure-difference devices are normally applied for

measurement. Calibration is recommended where a reduction of overall measuring uncertainty

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SIST EN 60953-1:2000
— 15 — 953-1 © I EC
fl ow is recommended for the reduction
is desirable. Double or multiple measurement of primary

of measuring uncertainty and a method for checking the compatibility is described.

Pressure measurement

The requirements and recommendations for pressure measurements are essentially similar. Only

the methods for the measurement of exhaust-pressure of condensing turbines differ to some

extent.
d) Temperature measurement

The requirements are essentially similar in both methods. However detail requirements are more

stringent in Method A:
calibration before and after the test,
— double measurement of the main temperature with 0.5 K maximum difference,
— thermocouples with continuous leads,
— required overall accuracy.
e) Steam quality measurements
Methods A and B are identical.
5) Evaluation of tests

The preparatory work for the evaluation and calculation of the test results is covered in a very

similar manner in Methods A and B. However, quantitative requirements are more stringent in

Method A.

Method B contains some proposals for handling cases where some requirements have not been

met to avoid rejection of the test.

In addition, Method B contains detailed methods for calculation of measuring uncertainty values

of measured variables and test results.

Method B recommends other methods for conducting and evaluating of the tests after the

specified period and without a previous inspection.
6) Correction of test results and comparison with guarantees

The correction of test results to guarantee conditions is covered in both Methods A and B.

Method A provides for the comparison of test results to guarantee without consideration of

measuring uncertainty.

Method B gives a broader spectrum of correction procedures. Furthermore, the measuring

uncertainty of the result is taken into account in the guarantee comparison.
7) Proposals for application

Since the acceptance test method to be applied has to be considered in the details of the plant

design, it should be stated as early as possible, preferably in the turbine contract, which method will

be used.

Method B can be applied to steam turbines of any type and any power. The desired measuring

uncertainty should be decided upon sufficiently early, so that the necessary provisions can be

included in the plant.

If the guarantee includes the complete power plant or large parts thereof, the relevant parts of

either method can be applied for an acceptance test in accordance with the definition of the

guarantee value.
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SIST EN 60953-1:2000
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953-1 © IEC
Scope and object
1.1 Scope

The rules given in this standard are applicable primarily to thermal acceptance tests with

high accuracy for condensing steam turbines driving generators for electric power services.

Some of the provisions of these rules are relevant to turbines for applications other than

driving electric power generators.

These rules provide for the testing of turbines operating with either superheated or satu-

rated steam. They include measurements and procedures required to determine specific

enthalpy within the moisture region and describe precautions necessary to permit testing

while respecting radiological safety rules in nuclear plants.

These rules contain information also applicable to the testing of back-pressure turbines,

extraction turbines and mixed-pressure turbines. Only the relevant portion of the rules need

apply to any individual case.

Uniform rules for the preparation, carrying out and evaluation of the acceptance tests are

defined in this standard. Details of the conditions under which the acceptance tests shall take

place are included.

Should any complex or special case arise not covered by these rules, appropriate agreement

shall be reached by manufacturer and purchaser before the contract is signed.
1.2 Object

The purpose of the thermal acceptance tests of steam turbines and turbine plants described

in this standard is to verify any guarantees given by the manufacturer of the plant concerning:

a) turbine plant thermal efficiency or heat rate;
flow

turbine thermodynamic efficiency or steam rate or power output at specified steam

conditions;
c) main steam flow capacity and/or maximum power output.

The guarantees with their provisions shall be formulated completely and without contradic-

tions (see 2.4). The acceptance tests may also include such measurements as are necessary for

corrections according to the conditions of the guarantee and checking of the results.

1.3 Matters to be considered in the contract

Some matters in these rules have to be considered at an early stage. Such matters are dealt

with in the following sub-clauses:
Sub-clause
(paragraph 4)
1.1
1.2 (paragraph 2)
(paragraphs 3 and 4)
3.1
(paragraph 1)
3.3.3
6.6
6.8
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SIST EN 60953-1:2000
IEC — 19 —
953-1 ©
2. Units, symbols, terms and definitions
2.1 General

The International System of Units (SI) is used in these rules; all conversion factors can

therefore be avoided.

The coherent units for all relevant quantities are given in the Table in 2.2. Some conversion

factors are given as well for specific heat rates based on units other than W/W.
2.2 Symbols, units

For the purpose of these rules the following symbols, definitions and units shall be used:

Exemples de
Autres unités
Symboles Unités multiples et
Grandeurs
ISO
sous-multiples
P W kW
Puissance
kg/s
Débit masse m
bar1>
Pa kPa
Pression absolue Jabs
bar)>
Pa kPa
Pression manométrique
Pa kPa bar)) mbar
Pression ambiante (barométrique)
Pamb
Ap Pa kPa .
Différence de pression
Température thermodynamique T, O
t, S °C
Température Celsius
At K
Ecart de température
H m mm
Distance verticale
h J/kg kJ/kg
Enthalpie massique
J/kg kJ/kg
Chute d'enthalpie massique Ah
c J/kg • K kJ/kg • K
Chaleur massique
Titre (masse de vapeur saturée sèche
x kg/kg g/g
par unité de masse de vapeur humide)
min-'
n s-I
Vitesse de rotation
m/s
Vitesse linéaire y
e kg/m3
Masse volumique
y m3/kg
Volume massique
D m mm
Diamètre
g m/s2
Accélération de la pesanteur
W/W kW/kW
Rendement thermique
rit
W/W kW/kW
Rendement thermodynamique rltd
kW/kW kJ/kW • s,
HR W/W
Consommation spécifique de chaleur
kJ/kWh
kg/kW • h
SR kg/W • s kg/kW • s
Consommation spécifique de vapeur
kg/J kg/kJ
Q J/s kJ/s
Débit de chaleur
Facteur de cavitation K
C Selon nature
Concentration
du traceur
F 1
Facteur de correction selon 6.6a)
Facteur de correction selon 6.6b) F*
Exposant isentropique K
Coefficient de décharge Cd —
Coefficient de débit a —
Admitted by CIPM and ISO for temporary use with fluids only.
1 )
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SIST EN 60953-1:2000
953-1 © IEC — 21 —
Relation between Heat Rate and Thermal Efficiency:
Units used for HR Relationship
W/W, kW/kW, kJ/kW  s
HR = 1
tic
3 600
kJ/kW  h HR —
tit
1 000
kJ/MW s HR —
ti t
859.845
— kcal/kW  h HR
tit
3412.14
— BTU/kW  h HR
tit
Subscripts, superscripts and definitions
2.3
Quantity Subscript Position or definition
Power b At generator terminals
a Taken by auxiliaries not driven by the turbine (see 4.2.3);
(see also IEC 34)
Net power output: P5 = Pc, — P;,
c At turbine coupling, less power required by turbine
auxiliaries, if driven separately (see 4.2.3)
Internal to the turbine
mech Mechanical losses of pump and pump drive
Initial steam flow rate and output max Values for fully opened control valves

Steam condition and flow rate 1 Directly upstream of high pressure (HP) turbine stop

valve(s) and the steam strainer(s) (if any) that are
included in the turbine contract
2 At exhaust of the turbine HP from which steam passes to the
reheater
Directly upstream of intermediate pressure (IP) turbine stop
valves
4 At exhaust of the turbine(s) discharging to the condenser
Condensate and feed water 5 At condenser discharge
conditions and flow rates
6 At inlet to condensate pump
7 At discharge from condensate pump
8 See figure la
At inlet of boiler feed pump
10 At outlet of boiler feed pump
lI At outlet of final feed heater
b After passage through the condensate pump and any coolers
(oil, generator, gas/air) included in the contract
d At outlet from the drain cooler
a At outlet of air ejector condenser
Refers to water taken from the feed-water system to the
superheater for regulation of the initial steam temperature
ir Refers to water taken from the feed-water system to the
reheater for control of the reheated steam temperature
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SIST EN 60953-1:2000
953-1 © IEC - 23 -
Position or definition
Quantity Subscript

Make up water conditions and m Measurements adjacent to the inlet flange of the condensate

flow rate system or of the evaporator

Gland steam conditions and flow g Steam supplied to glands from a separate source

rates
gl Leak-off steam from glands and valve stems returned to the
system and included in the initial steam flow
q Flow of leak-off steam from glands and valve stems at inlet
end or before a reheater which is led away for any
extraneous purpose and neither it nor its heat is delivered
to any part of the turbine cycle
qy Leak-off flows similar to q, but coming from a point or
points downstream of a reheater
Main steam flow rate and concen- M Main steam flow at outlet of reactor
tration
Mass flow rate and concentration F Refers to feed-water for reactor
core Refers to medium fluid passing through reactor core
cond Refers to condensed steam
Refers to injected tracer solution
inj
Mass flow rate and concentration
At entry into core of PWR
Recirculated water flow from water separator
Condenser cooling water
wi Condenser inlet
wo Condenser outlet
Average value between condenser inlet and outlet
wio
Thermal
Efficiency t
Thermodynamic
s Refers to isentropic enthalpy drop
Enthalpy drop
At throat of flow-metering nozzle
throat
Velocity
Saturation pressure of water at pertinent temperature
sat
Static pressure
wat In water phase
Concentration
L In pump loop of BWR
In blow-down water of PWR
Of injected tracer
inj
At injection point before tracer injection
g Guaranteed
Test results and guaranteed values
Corrected
Measured
Product of all individual correction factors
tot
Correction factor F or F*
Numbering of individual correction factors
I, 2, 3
For correction of efficiency
For correction of output
i, j Numbering subscripts
General use
Definition
Superscript
Quantity
Reference value of computer-calculated efficiency
Efficiency
— Average value
General
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SIST EN 60953-1:2000
953-1 © IEC — 25 —
mgl
483/90
GC: Generator gas cooler
OC: Oil cooler
DC: Drain cooler
EC: Air ejector condenser

The point number remains the same for the same item of any other turbine type: for example, Point 9 will be at the inlet of

the feed pump, Point 8 may be anywhere between Points 6 and 11.
FIG. la. — Reheating regenerative condensing turbine with feed-water heating.
FtG. b. — Straight condensing or hack-pressure turbins without feed-heating.
FIG. 1. — Diagram for interpretation of symbols and subscripts.
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SIST EN 60953-1:2000
953-1 © I EC — 27 —
2.4
Definition of guarantee values and lest results

For the quantitative description of the thermodynamic performance of a steam turbine or

steam turbine plant, several quantities are technically appropriate and generally applied.

Guaranteed values are expressed as such quantities and, consequently, test results are to be

evaluated in the same manner.

The general definition of these quantities is always quite obvious. The details, however,

may be different in each case and shall be fully considered (see also 1.2).
2.4.1
Thermal efficiency

For a power station turbine with regenerative feed heating, the thermal efficiency is the

significant criterion. It is defined as the ratio of power output to heat added to the cycle from

external sources.
(1)
t— ^ (mi 0 hi)
where:
M . , are the mass flows, to which heat is added
Oh, the resulting enthalpy rises

For each specific case a guarantee heat cycle together with the guarantee terminal par-

ameters has to be defined as a basis for guarantee definition and test evaluation. It should be

as simple as possible and as near as practicable to the cycle configuration to be realized for the

test (see also 3.4.4).

A practical definition for a turbine plant with single reheat and feed heating according to

figure 1 a is then:
_ Pb (or Pg or P )*
(2)
i — h i i ) + m 3 — h2)
m i (h 3 (h

Any additional heat and/or mass flow added to or subtracted from the cycle for example by

make-up flow m m , spray attemperator flow Mir or /his or additional extraction for steam air

preheater has to be accounted for in the evaluation by an appropriate correction of the test

result (see Clause 6). Losses are not included in this definitio
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