Shell boilers - Part 11: Acceptance tests

This Part of this European Standard specifies a concise procedure for conducting thermal performance tests, using the indirect (losses) procedure for boilers for steam or hot water. Test results are based on either the gross or net calorific value of the fuel.
This concise procedure provides a convenient means for assessing boilers which thermodynamically simple, i.e. having a single major source of heat input and a simple circuit for water, steam or high temperature heat transfer fluid.
NOTE 1   The use of the direct method is not advocated, because the estimated measuring error is three to four times greater than with the indirect method.
NOTE 2   An acceptance test may be required:
a) after the commissioning of new plant or after the recommissioning of modified plant in order to verify compliance with a specification or contractual obligation;
b) whenever the user wishes to determine the current performance of the plant either on a route basis or due to change of load or other operating conditions or when a change of fuel or a modification to the plant is being considered;
c) whenever the user wishes to check combustion conditions.
Regular tests in accordance with this European Standard will enable boiler plant to be monitored in normal operation for opti-mum efficiency in the interests of fuel conservation.
This procedure does not cover condensing boilers. The application of boilers, where heat is extracted from waste gases is specified in annex B.

Großwasserraumkessel - Teil 11: Abnahmeversuche

Dieser Teil dieser Europäischen Norm beschreibt ein Kurzverfahren zur Durchführung von Wärmeleistungs-beurteilungen, unter Anwendung des indirekten (Verlust-) Verfahrens für Dampf- und Heißwasserkessel. Prüf---ergebnisse basieren entweder auf Brutto- oder Netto-Brennwerten.
Dieses Kurzverfahren ermöglicht eine geeignete Möglichkeit zur Beurteilung von Kesseln, die thermodynamisch einfach aufgebaut sind, d. h. die Wärmeeinbringung erfolgt durch eine einzige größere Wärmequelle und über      einen einfachen Wasserkreislauf, mit Dampf oder Hochtemperatur-Wärmeübertragungsflüssigkeiten.
ANMERKUNG 1      Die Anwendung der direkten Methode ist nicht verbindlich, da der zu erwartende Messfehler drei bis viermal größer ist als bei der indirekten Methode.
ANMERKUNG 2      Eine Beurteilung kann erforderlich sein:
a) nach Inbetriebnahme einer neuen Anlage oder nach Wiederinbetriebnahme einer umgebauten Anlage, um die Übereinstimmung mit einer Spezifikation oder vertraglichen Verpflichtung zu überprüfen;
b) wenn der Anwender die aktuelle Leistung der Anlage bestimmen will entweder auf Richtlinienbasis oder auf Grund einer Änderung der Auslastung oder anderer Betriebsbedingungen oder wenn eine Änderung des Brennstoffes oder ein Umbau der Anlage erwägt wird;
c) wann immer der Anwender die Verbrennungsbedingungen überprüfen will.
Laufende Prüfungen nach dieser Europäischen Norm werden genutzt um Dampfkesselanlagen in Normalbetrieb bezüglich des Brennstoffverbrauchs zu optimieren.
Dieses Verfahren beinhaltet keine Kondensationskessel. Die Anwendung auf Dampfkessel, bei denen die Wärme aus Abhitze erzeugt wird, ist in Anhang B beschrieben.

Chaudières à tubes de fumée - Partie 11: Essais de réception

La présente partie de cette Norme européenne décrit une procédure précise d'évaluation des performances thermiques, faisant appel à la procédure indirecte (déperditions) pour les chaudières utilisant de la vapeur ou de l'eau surchauffée. Les résultats d'essai sont fondés sur le pouvoir calorifique supérieur ou inférieur du combustible.
Cette procédure précise fournit un moyen approprié d'évaluation des chaudières thermodynamiquement simples, c'est-à-dire ayant une seule source principale d'apport calorifique et un circuit simple pour l'eau, la vapeur ou le fluide caloporteur à température élevée.
NOTE 1   L'utilisation de la méthode directe n'est pas conseillée, car l'erreur estimée de mesure est trois à quatre fois supérieure à l'erreur observée avec la méthode indirecte.
NOTE 2   Un essai de réception peut être requis :
a) après la mise en service d'une nouvelle installation ou après la remise en service d'une installation modifiée afin de vérifier la conformité à une spécification ou à une obligation contractuelle ;
b) chaque fois que l'utilisateur souhaite déterminer les performances courantes de l'installation de façon régulière ou suite à un changement de la charge ou à un changement d'autres conditions de fonctionnement, ou lorsqu'il est envisagé de changer de combustible ou de modifier l'installation ;
c) chaque fois que l'utilisateur souhaite vérifier les conditions de combustion.
Des essais réguliers conformément à la présente Norme européenne permettent de contrôler l'installation de chaudière en fonctionnement normal pour un rendement optimum permettant d'économiser le combustible.
Cette procédure ne couvre pas les chaudières à condensation. L'application des chaudières, dans lesquelles la chaleur est récupérée de gaz perdus est spécifiée en Annexe B.

Mnogovodni kotli – 11. del: Prevzemni preskusi

General Information

Status
Withdrawn
Publication Date
30-Dec-2003
Withdrawal Date
30-Mar-2004
Current Stage
9092 - Decision on results of review/2YR ENQ - revise - Review Enquiry
Completion Date
24-Mar-2021

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Mnogovodni kotli – 11. del: Prevzemni preskusiGroßwasserraumkessel - Teil 11: AbnahmeversucheChaudieres a tubes de fumée - Partie 11: Essais de réceptionShell boilers - Part 11: Acceptance tests27.060.30Grelniki vode in prenosniki toploteBoilers and heat exchangersICS:Ta slovenski standard je istoveten z:EN 12953-11:2003SIST EN 12953-11:2004en01-junij-2004SIST EN 12953-11:2004SLOVENSKI

STANDARD
SIST EN 12953-11:2004

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12953-11September 2003ICS 27.060.30; 27.100English versionShell boilers - Part 11: Acceptance testsChaudières à tubes de fumée - Partie 11: Essais deréceptionGroßwasserraumkessel - Teil 11: AbnahmeversucheThis European Standard was approved by CEN on 24 July 2003.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and UnitedKingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36

B-1050 Brussels© 2003 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12953-11:2003 ESIST EN 12953-11:2004

EN 12953-11:2003 (E)2ContentspageForeword......................................................................................................................................................................31Scope..............................................................................................................................................................42Normative references....................................................................................................................................43Terms and definitions....................................................................................................................................54Symbols and abbreviations..........................................................................................................................64.1Symbols and units.........................................................................................................................................64.2Coefficients.....................................................................................................................................................85General............................................................................................................................................................86Basic test conditions.....................................................................................................................................86.1General conditions........................................................................................................................................86.2Steady-state conditions................................................................................................................................96.3Test procedure...............................................................................................................................................96.4Requirements during test...........................................................................................................................106.5Duration of tests...........................................................................................................................................106.6Procedure for the determination of exhaust gas temperature and CO, CO2 and O2 content..............106.7Undetermined losses...................................................................................................................................107Instrumentation and methods of measurements.....................................................................................107.1Instruments...................................................................................................................................................107.2Pressure measurements.............................................................................................................................117.3Temperature measurements.......................................................................................................................117.4Mass and mass flow....................................................................................................................................117.5Calorific values.............................................................................................................................................127.6Chemical composition.................................................................................................................................128Heat balance and thermal efficiency..........................................................................................................138.1General..........................................................................................................................................................138.2Envelope boundary......................................................................................................................................138.3Reference temperature................................................................................................................................158.4Heat input......................................................................................................................................................158.5Losses...........................................................................................................................................................168.6Determination of efficiency by indirect method.......................................................................................198.7Useful heat output.......................................................................................................................................209Accuracy.......................................................................................................................................................20Annex A (informative)

Calculation of combustion air/flue gas mass to fuel mass ratios and specificheat................................................................................................................................................................21A.1Combustion air/flue gas mass to fuel mass ratios...................................................................................21A.2Ultimate analysis..........................................................................................................................................22A.3Statistical analysis.......................................................................................................................................25A.4Specific heat of flue gas and combustion air...........................................................................................26Annex B (normative)

Waste heat boilers................................................................................................................29B.1General..........................................................................................................................................................29B.2Useful heat output.......................................................................................................................................29B.3Heat from waste gases................................................................................................................................29B.4Heat input......................................................................................................................................................30B.5Thermal efficiency........................................................................................................................................30B.6Methods of measurement...........................................................................................................................30Bibliography..............................................................................................................................................................32SIST EN 12953-11:2004

EN 12953-11:2003 (E)3ForewordThis document (EN 12953-11:2003) has been prepared by Technical Committee CEN/TC 269 “Shell and water-tube boilers”, the secretariat of which is held by DIN.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by March 2004, and conflicting national standards shall be withdrawn at the latest byMarch 2004.This European Standard has been prepared under a mandate given to CEN by the European Commission and theEuropean Free Trade Association. This European Standard is considered as a supporting standard to otherapplication and product standards which in themselves support an Essential Safety requirement of a NewApproach Directive and will appear as a normative reference in them.The European Standard EN 12953 concerning shell boilers consists of the following Parts: Part 1:General. Part 2:Materials for pressure parts of boilers and accessories. Part 3:Design and calculation for pressure parts of the boiler. Part 4:Workmanship and construction of pressure parts of the boiler. Part 5:Inspection during construction, documentation and marking of pressure parts of the boiler. Part 6:Requirements for equipment for the boiler. Part 7:Requirements for firing systems for liquid and gaseous fuels for the boiler. Part 8:Requirements for safeguards against excessive pressure. Part 9:Requirements for limiting devices of the boiler and accessories. Part 10:Requirements for boiler feedwater and boiler water quality. Part 11:Acceptance tests. Part 12:Requirements for grate firing systems for solid fuels for the boiler. Part 13:Operating instructions.CR 12953-14: Guideline for the involvement of an inspection body independent of the manufacturer.Although these Parts can be obtained separately, it should be recognized that the Parts are interdependent. Assuch, the design and manufacture of shell boilers requires the application of more than one Part in order for therequirements of the European Standard to be satisfactorily fulfilled.The annex A of this European Standard is informative. The annex B of this European Standard is normative.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following coun-tries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,Slovakia, Spain, Sweden, Switzerland and the United Kingdom.SIST EN 12953-11:2004

EN 12953-11:2003 (E)41 ScopeThis Part of this European Standard specifies a concise procedure for conducting thermal performance tests, usingthe indirect (losses) procedure for boilers for steam or hot water. Test results are based on either the gross or netcalorific value of the fuel.This concise procedure provides a convenient means for assessing boilers which are thermodynamically simple,i.e. having a single major source of heat input and a simple circuit for water, steam or high temperature heat trans-fer fluid.NOTE 1The use of the direct method is not advocated, because the estimated measuring error is three to four times greaterthan with the indirect method.NOTE 2An acceptance test may be required:a) after the commissioning of new plant or after the recommissioning of modified plant in order to verify compliance with aspecification or contractual obligation;b) whenever the user wishes to determine the current performance of the plant either on a routine basis or due to change ofload or other operating conditions or when a change of fuel or a modification to the plant is being considered;c) whenever the user wishes to check combustion conditions.Regular tests in accordance with this European Standard will enable boiler plant to be monitored in normal operation for opti-mum efficiency in the interests of fuel conservation.This procedure does not cover condensing boilers. The application of boilers, where heat is extracted from waste gases isspecified in annex B.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN ISO 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full - Part 1: General principles and requirements (ISO 5167-1:2003).ISO 157, Coal — Determination of forms of sulfur.ISO 334, Solid mineral fuels — Determination of total sulfur — Eschka method.ISO 589, Hard coal — Determination of total moisture.ISO 609, Solid mineral fuels — Determination of carbon and hydrogen — High temperature combustion method.ISO 625, Solid mineral fuels — Determination of carbon and hydrogen — Liebig method.ISO 1928, Solid mineral fuels — Determination of gross calorific value by the bomb calorimetric method, and cal-culation of net calorific value.ISO 1988, Hard coal — Sampling.ISO 3170, Petroleum liquids — Manual sampling.ISO 6976, Natural gas — Calculation of calorific values, density, relative density and Wobbe index from composi-tion.SIST EN 12953-11:2004

EN 12953-11:2003 (E)53 Terms and definitionsFor the purposes of this European Standard, the following terms and definitions apply.3.1indirect method (Heat loss method)determination of all accountable heat losses. The efficiency is then equal to 1

minus the ratio of the sum of all heatlosses to the sum of heat in the fuel plus heat credits3.2standard conditioncondition at pn = 0,101325 N/mm2 and tn = 0 °C3.3assessed lossesany thermal losses established from predetermined data3.4gross calorific value (GCV)amount of heat liberated by the complete combustion, under specified conditions, of unit volume of a gas or unitmass of a solid or liquid fuel in the determination of which the water produced by combustion of the fuel is assumedto be completely condensed and its latent and sensible heat made available3.5net calorific value (NCV)amount of heat generated by the complete combustion, under specified conditions, of unit volume of a gas or unitmass of a solid or liquid fuel in the determination of which the water produced by combustion of the fuel is assumedto remain as a vapour3.6heat inputheat content of the fuel used during the test based on the gross or net calorific value plus the sensible heat in thefuel above reference temperature plus the sensible heat in the combustion air above reference temperature3.7heat outputheat gained by the heat carrier from the boiler during the period of the test3.8measured lossany thermal losses calculated from actual measurements made during the test3.9radiation, convection and conduction losseslosses from water, steam, combustion air, or gas-backed surfaces prior to the flue gas temperature measurementpoint and directly from flame to the floor and surroundings of the unit3.10test errorcombined error due to sampling, measurements, calculations and assumptions used to obtain test results. Theoverall effect may be positive or negative3.11thermal efficiencythe difference between 100 % and the total percentage losses based on either the gross or net calorific value of thefuel which is equivalent to the ratio of the useful heat output to the heat input expressed as a percentage3.12turn-down ratiothe ratio of maximum and minimum fuel inputs for continuous firing in unit time specified by the manufacturer whichcan also be expressed in terms of boiler output provided the appropriate efficiencies are known.SIST EN 12953-11:2004

EN 12953-11:2003 (E)64 Symbols and abbreviations4.1 Symbols and unitsFor the purposes of this European Standard the symbols and abbreviations given in EN 12952-1:2002, table 4-1and the following table 4.1-1 and the subscripts given in table 4.1-2 shall apply.Table 4.1-1 — SymbolsSymbolDescriptionUnitcSpecific heat capacity akJ/(kgK)cIntegral specific heat capacity akJ/(kgK)HCalorific value (CV)kJ/kghSpecific enthalpykJ/kgiNumber of samples—JEnthalpy of flue gas or combustion air related to fuel mass flowkJ/kgLLatent heat (heat of vaporization)kJ/kglSingle loss—luRatio of unburned combustibles to supplied fuel mass flowkg/kgMMolar masskg/kmolmMasskgmMass flowkg/snAir factor at boiler outlet—pPressureN/mm2QHeat flowkWTThermodynamic temperatureKtTemperature Celsius°CuUnburned combustibles content (by mass)kg/kgVCombustion air and flue gas volume (per unit mass of fuel)m3/kgxFlue gas/combustion air components content by masskg/kgyContent by volumem3/m3Thermal efficiency—Fuel content (by mass)kg/kgVolatile matter content of ashkg/kgDensitykg/m3µCombustion air/flue gas mass to fuel mass ratiokg/kgNOTE 11 N/mm2 = 1 MN/m2 = 1 MpaNOTE 2The units shown are those normally used. Conversion may be necessary for use in the dimensionless equations.a'specific heat', for short.SIST EN 12953-11:2004

EN 12953-11:2003 (E)7Table 4.1-2 — SubscriptsSymbolDescriptionAAirAshAshBBoilerCCarbonCOCarbon monoxideCO2Carbon dioxidedDry (basis)EUseful, effectiveFAFlu dust (fly ash)FFuel, burned fuelFoFuel suppliedFwFeed waterGFlue gas (combustion gas)(G)Gross valueHHydrogenH2OWateriNumber of componentsmAveragemeasMeasuredminMinimumNNitrogen(N)Net valuenStandard conditionoStoichiometricO2OxygenpConstant pressurerReference temperatureRCRadiation and convectionSSulfurSFAsh and flue dustSTLive steamtotTotaluUnburned matterZHeat input^Maximum0at 0 °C1in2outSIST EN 12953-11:2004

EN 12953-11:2003 (E)84.2 CoefficientsFor the purposes of this European Standard the coefficients given in Table 4.2-1 shall apply.Table 4.2-1 — CoefficientsDesignationSymbolValueUnitSpecific latent heat at 25 °CLr2 442,5kJ/kgSpecific heat of steam between 25 °C and 150 °CpStc1,884kJ/(kg K)Specific heat of water between 25 °C and 150 °CpWc4,21kJ//kg K)Specific heat of air between 25 °C and 150 °CpAc1,011kJ//kg K)Specific heat of ash and flue dust between 25 °C and200 °CFAAsh,cc0,84kJ//kg K)CV of unburned matter:Hard coalH(N)u33,0MJ/kgBrown coalH(N)u27,2MJ/kg5 General5.1Where a thermal performance assessment is to be carried out after the commissioning of new plant or afterthe recommissioning of modified plant, it shall be decided at the plant tendering or ordering stage on the test datarequired and on the accuracy and hence the instrumentation to be used.It is necessary for the parties concerned to decide whether the test shall be carried out by the contractor or by anindependent body and by whom is to be witnessed.5.2Tests shall represent the intended method and system of operation of the plant under the intended condi-tions of installation and normal operation. The determination of electrical consumption is not part of this EuropeanStandard.5.3Tests shall be carried out at predetermined firing rates, as agreed between the parties concerned.6 Basic test conditions6.1 General conditionsTests shall be carried out whilst the boiler is fired continuously under steady state conditions established prior tothe test (see 6.2).NOTEAn outline of the procedure for calculating the heat output from test measurements is shown in Figure 6.1-1.SIST EN 12953-11:2004

EN 12953-11:2003 (E)9Figure 6.1-1 — Outline of the procedure for calculating the heat output from the test measurement6.2 Steady-state conditions6.2.1Steam pressure, steam and feed water temperature or, for hot water generator, the flow and returntemperatures, together with the relevant flow rates, shall be held as steady as possible and at levels close tonormal operating conditions. These measurements shall be taken at the boiler exit or as closed as practical at the(same) test prior.NOTEDuring the operation of a boiler the various factors contributing to heat losses can vary from their intended values asa result of the absorption of heat by the boiler structure as it acquires the conditions determined for the test and as a result ofthe operation of automatic controls. The most important variables are the exhaust gas temperature and the CO2 or O2 content ofthe exhaust gases. It is therefore essential that tests are conducted only after steady-state conditions have been achieved.6.2.2For the purposes of this standard, steady-state conditions shall be deemed to have been reached for solidfuel fired boilers with continuous fuel and ash flows and for liquid and gaseous fuel-fired boilers, when during theperiod of the test, variation in exhaust gas temperature remains within 10 C and variation of oxygen content within0,5 % from the mean value.6.3 Test procedure6.3.1It shall be confirmed that the water treatment is being carried out in accordance with the instructions of theboilermaker and the supplier of the water treatment plant. Where necessary during the preliminary running of theboiler prior to the test, except when testing under 'as found' conditions (see 6.3.2), the gas side surfaces shall becleaned, the fuel input and fuel air ratio shall be set and adjustment of the combustion chamber draught orpressure shall be made to conditions laid down by the boilermakers before establishing steady-state conditions.6.3.2When testing under 'as found' conditions, e.g. whenever the user wishes to determine the current perform-ance of the plant, no adjustments to the firing equipment shall be made and no cleaning of the gas-side surfacesshall be carried out prior to the commencement of the test.SIST EN 12953-11:2004

EN 12953-11:2003 (E)10NOTEFactors relating to maladjustment of the firing equipment, grit and dust emission, fouled heat transfer surfaces or theformation of CO be shown up by such tests and will be a guide to improvements in operation, which should be confirmed byretest. A comparison with the manufacturer's performance data should be made.6.4 Requirements during testDuring the running of the test, the blowdown of steam boilers shall be avoided and the water level in the gaugeglasses shall be held as steady as possible during the establishment of steady-state conditions and during thesubsequent test.Where automatic high/low or fully modulating firing equipment is fitted, no manual adjustment of combustionsettings during the overall test period shall be carried out (see 5.2).6.5 Duration of testsFollowing the establishment of the steady state, the test shall be of sufficient duration for at least six complete setsof readings of fuel input, flue gas temperature and flue gas analysis. The readings shall be within the variationspermitted by the strict terms of steady conditions (see 6.2).6.6 Procedure for the determination of exhaust gas temperature and CO, CO2 and O2 contentThe procedure for the determination of exhaust gas temperature and CO, CO2 and O2 content shall be inaccordance with the methods in clause 7.6.7 Undetermined lossesUndetermined losses, i.e. losses which are neither measured nor assessed, can occur but shall be regarded asinsignificant for the purpose of this European Standard.7 Instrumentation and methods of measurements7.1 InstrumentsAll measurements shall be made with suitable calibrated instruments. Portable or mobile instruments shall be usedunless it can be shown that the sensors of installed instruments have been located correctly and the systemchecked for accuracy.Only such measuring instruments and/or transducers shall be used whose indications and/or output values areverifiable and whose limits of error are known. These shall include:a) instruments for which a verification certificate (calibration certificate issued by an authority) is submitted;b) verifiable instruments which have been calibrated before and after the test with the readings both rising andfalling, preferably under conditions simulating those existing during the test, and compared with theinstruments as per item a) above;c) standard instruments with known limits of error;d) other approved instruments with known limits of error, the use of which has been agreed upon by the parties tothe test.The measuring equipment shall not be subject to any appreciable permanent changes during the test.Analog or digital readings may be taken, and the data shall be recorded manually or automatically. The test reportshall detail the instruments used and their limits of error.If the data are recorded by automatic equipment, random checks shall be made to verify that the signals arecorrectly processed.SIST EN 12953-11:2004

EN 12953-11:2003 (E)117.2 Pressure measurementsPressure measurements shall be made using suitable pressure gauges or transducers. As far as possible, differen-tial pressures shall be directly measured by means of suitable gauges and instruments (e.g. U-tube manometers,inclined-tube micromanometers of differential pressure transducers). Mercury, water or other liquids of suitabledensity shall be used as indicating fluid.7.3 Temperature measurementsMeasurements of temperature shall be taken using instruments in accordance with 7.1, items a) and b) (e.g.mercury-in-glass thermometers, thermocouples and resistance thermometers, the latter in conjunction withappropriate measuring circuits of transducer [1]).7.4 Mass and mass flow7.4.1 WeighingThe weighing machines used shall be checked prior to testing for accuracy.7.4.2 Volumetric measurementsMeasurements of volume flow shall be carried out by volumetric meters which shall be calibrated prior to and,where possible, after the test. Only genuine volumetric meters (i.e. no vane-type meters) shall be permitted down-stream of reciprocating pumps. A uniform specific volume or density shall be maintained throughout the test.The volume shall also be determined by means of tanks that have been filled from verified tanks or containers andchecked by metering or calibrated with weighed increments of water.In the use of volumetric tanks, density corrections shall be made for differences in water temperature during testingand calibration. Corrections shall also be made for the thermal expansion of the tank. (The volume of a steel tank,for example, increases by roughly 0,4 % when heated by 100 C).7.4.3 Flow measurement7.4.3.1 Flow measurement with orifices and nozzlesFlow measurements with orifices and nozzles shall be in accordance with EN ISO 5167-1.Since dimensions cannot be checked and measurements taken prior to the acceptance test, this shall be carriedout before the welding operations, and the results recorded. Inconsistencies of inflow shall be dealt with in accor-dance with EN ISO 5167-1.Where flow rate transducers are used, the working characteristics under test conditions shall be determined beforethe test or a calibration graph plotted.7.4.3.2 Flow measurement with velocity probesFlow measurements using velocity probes (Pitot tubes or anemometers) shall be made in accordance withISO 1217, ISO 5389 or ISO 6801.7.4.4 Measurement of flue dust flowA suitable method shall be agreed for measuring the flue dust flow through a particular cross section (see also [2]and [4]).SIST EN 12953-11:2004

EN 12953-11:2003 (E)127.4.5 Determination of densityWhere the density is unknown, it shall be taken from the appropriate tables [5], employing the variables, i.e.pressure and temperature, and the composition, or the value shall be obtained from the gas supplier.7.5 Calorific values7.5.1 Calorific values of fuelThe gross calorific value (GCV, H(G)) and net calorific value (NCV, H(N)) of solid and liquid fuels shall be determindin accordance with ISO 1928 1). the GCV and NCV shall be determined from an analysis of gases of known andfixed composition in accordance with ISO 69762).7.5.2 Sampling of fuelsSolid fuel samples shall be taken and prepared in accordance with ISO 1988. The sampling of liquid and gaseousfuels shall be carried out respectively, in accordance with ISO 3170 (see also [6]). The samples taken shalladequately represent the grade, composition and quality of the fuel fired during the test.7.5.3 Net calorific value and sampling of carbon in ash and flue dustWhen required by 6.6.2 the NCV of the carbon in ash and/or flue dust the NCV shall be determined in accordancewith ISO 1928.The parties to the test may agree upon a simplified method for determining the NCV from the carbon content orloss on ignition. If determination of the NCV has not been agreed upon, the values specified in 4.2 shall beemployed as the NCV of total organic carbon.7.6 Chemical composition7.6.1 FuelsIf required, the ultimate analysis of solid and liquid fuels shall be made in accordance with ISO 589, ISO 609,ISO 625,

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