1、BRITISH STANDARD BS EN 13741:2003 Thermal performance acceptance testing of mechanical draught series wet cooling towers The European Standard EN 13741:2003 has the status of a British Standard ICS 91.060.50 BS EN 13741:2003 This British Standard, was published under the authority of the Standards P
2、olicy and Strategy Committee on 22 December 2003 BSI 22 December 2003 ISBN 0 580 43139 8 National foreword This British Standard is the official English language version of EN 13741:2003. The UK participation in its preparation was entrusted to Technical Committee RHE/30, Heat exchangers, which has
3、the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section ent
4、itled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Complian
5、ce with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related in
6、ternational and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 33 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amen
7、dments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN13741 December2003 ICS91.060.50 Englishversion Thermalperformanceacceptancetestingofmechanicaldraught serieswetcoolingtowers Essaisderceptiondesperformancesthermiquesdes arorfrigrantshumidestiragem
8、caniqueetfabriqus ensrie WrmetechnischeAbnahmeprfunganzwangsbelfteten standardisiertenNasskhltrmen ThisEuropeanStandardwasapprovedbyCENon1October2003. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandard
9、withoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibility
10、ofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Slovakia,Spa
11、in,Sweden,SwitzerlandandUn ited Kingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2003CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN13741:2003EEN1374
12、1:2003(E) 2 Contents Page Foreword . 4 1 Scope 5 2 Normativereferences 5 3 Terms,definitionsandsymbols 5 3.1 Termsanddefinitions. 5 3.2 Symbols . 8 4 PerformancetestsGeneral. . 10 4.1 Subjectofthethermalperformanceacceptance. 10 4.2 Performancecurves 10 4.2.1 Performancecurvesformat . 10 4.2.2 Perfo
13、rmancecurveparameters . 11 5 Measuringproceduresandinstrumentation 11 5.1 General . 11 5.2 Measurements . 12 5.2.1 Temperatures. 12 5.2.2 Waterflow 13 5.2.3 Fanpower . . 14 5.2.4 Coolingtowerpumpinghead . 14 5.2.5 Temperatureandflowofmakeupandblowdown 15 6 Acceptancetests . 15 6.1 General . 15 6.1.1
14、 Introduction . 15 6.1.2 Timeoftheacceptancetest . 15 6.1.3 Managementoftheacceptancetests . 15 6.2 Preparationofacceptancetests. . 15 6.2.1 Numberandarrangementofthemeasuringpoints 16 6.2.2 Conditionoftheplant . 16 6.3 Executionofacceptancetests. 17 6.3.1 Preconditions . 17 6.3.2 Trialmeasurements
15、17 6.3.3 Acceptabledeviationsofoperatingconditions . 17 6.3.4 Operatingconditionsduringthetest 18 6.3.5 Frequencyofreadings. . 18 6.3.6 Testduration. . 19 6.3.7 Validityoftestresults . 19 7 Assessmentoftestresultsinviewofguaranteedperformancedata. 19 7.1 Assessmentoftestresults 19 7.2 Findingoffacev
16、aluesfromperformancedata 19 7.3 Comparisonwiththeguaranteedperformancedata. 20 8 Testtolerance 20 8.1 General . 20 8.2 Errorcreatedbymeasuringtolerances . . 20 8.2.1 Influenceofwetbulbmeasurementuncertainties FF w . 21 8.2.2 Influenceofcoolingrangemeasurementuncertainties F z21 8.2.3 Influenceoffanp
17、owermeasurementuncertainties F F21 8.2.4 Influenceofwaterflowratemeasurementuncertainties FF m21 8.3 Determinationofmeasuringequipmenttolerances 21EN13741:2003(E) 3 8.4 Determinationofmeasuringtolerances . 22 8.5 Determinationofrandomerrors 22 8.6 Determinationofthetesttolerance. 23 9 Testreport. .
18、23 AnnexA (informative) Example.24 AnnexB (informative) Performancecurves. 25 AnnexC (informative) Positionofmeasuringpointsforcoolingtowers . 29 AnnexD (informative)TestResultanalysis . 31 Bibliography . 33EN13741:2003(E) 4 Foreword Thisdocument(EN13741:2003)hasbeenpreparedbyTechnicalCommitteeCEN/T
19、C110“Heat Exchangers“,thesecretariatofwhichisheldbyBSI. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofan identicaltextorbyendorsement,atthelatestbyJune2004,andconflictingnationalstandardsshall bewithdrawnatthelatestbyJune2004. AnnexesA,BandCareinformative. Accordi
20、ngtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthe followingcountriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,Czech Republic,Denmark,Finland,France,Germany,Greece,Hungary,Iceland,Ireland,Italy,Luxembourg, Malta,Netherlands,Norway,Portugal,Slovakia,Spain,Swede
21、n,SwitzerlandandtheUnited Kingdom.EN13741:2003(E) 5 1Scope ThisEuropeanStandardspecifiesrequirements,testmethodandacceptancetestsforthermal performanceofmechanicaldraughtseriescoolingtowers. ThisEuropeanStandardisapplicabletoseriestypewetcoolingtowersasdefinedin3.1. Theacceptancetestingcoverstheveri
22、ficationofthethermalandhydraulicperformancedataofthe coolingtowerselectedfromtheproductline(see3.1)andspecifiedinthecontractbetweenthe supplierandthepurchaser.Ifthesetestsarerequiredthenthisshouldberecognizedatthetimeof thecontract,asadditionalfittings,andpreparationsforthetestmayberequired. Amethod
23、ologytocalculatethetesttoleranceisincludedinthisstandard.Thecontractshouldspecify whetherthismethodologyshallbeusedfortheassessmentofthetestresultsornot. Legalandcommercialconsequencesthatmightresultfromachievingornotachievingthe contractuallyagreedperformancearenotpartofthisEuropeanStandard. 2 Norm
24、ativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromother publications.Thesenormativereferencesarecitedattheappropriateplacesinthetextandthe publicationsarelistedhereafter.Fordatedreferences,subsequentamendmentstoorrevisionsofany ofthesepublicationsapplytothisEuro
25、peanStandardonlywhenincorporatedinitbyamendmentor revision.Forundatedreferencesthelatesteditionofthepublicationreferredtoapplies(including amendments). Notapplicable. 3 Terms,definitionsandsymbols 3.1Termsanddefinitions ForthepurposesofthisEuropeanStandard,thefollowingtermsanddefinitionsapply. 3.1.1
26、 airflowrate totalamountofdryairandassociatedwatervapourmovingthroughthecoolingtower 3.1.2 approach differencebetweencoldwatertemperatureandtheinletwetbulbtemperature 3.1.3 approachdeviation deviationbetweenthedesignapproachandthemeasured(adjusted)approach 3.1.4 barometricpressure atmosphericpressur
27、eatthetestsiteEN13741:2003(E) 6 3.1.5 basin openstructurelocatedbeneaththecoolingtowerforcollectingthecirculatingwateranddirectingitto thesumporsuctionlineofthecirculatingpump 3.1.6 basincurb topelevationofthetowerbasin usuallythedatumfromwhichthetowerelevationsaremeasured. 3.1.7 blowdown waterdisch
28、argedfromthesystemtocontroltheconcentrationofsaltsorotherimpuritiesinthe circulatingwater 3.1.8 cell smallestsubdivisionofthetower,boundedbyexteriorwallsandpartitionwalls,whichcanfunctionas anindependentunitEachcellmayhaveoneormorefansorstacksandoneormoredistribution systems 3.1.9 coldwatertemperatu
29、re averagetemperatureofthewaterenteringorleavingthetowerbasinInthecasewherethe measurementisdownstreamofthebasinorthepump,correctionsareneededfortheeffectsofthe pump,andanyothermakeupwaterblowdownorheatsourcesenteringthebasin 3.1.10 coolingrange differencebetweenthetemperatureofthewaterenteringthedi
30、stributionsystemandthecoldwater temperature 3.1.11 coolingtower apparatusinwhichwateriscooleddownbyheatexchangewithambientair 3.1.12 drifteliminator theassembliesdownstreamoftheheattransfermedia,whichservetoreducethedriftloss 3.1.13 driftloss portionofthewaterflowratelostfromthetowerinformoffinedrop
31、letsmechanicallyentrainedinthe dischargeairstream,commonlyexpressedasmassperunittimeorapercentageofthecirculating waterflowrate.Itisindependentbywaterlostfromevaporation 3.1.14 drybulbtemperature temperatureofanairvapourmixtureindicatedbyathermometerwithaclean,drysensingelement thatisshieldedfromrad
32、iationeffects.Maybefurthercategorisedaseither: a) ambientdrybulbtemperature:thedrybulbtemperatureofairmeasuredwindwardofthetower andfreefrominfluenceofthetower b) enteringdrybulbtemperature:thedrybulbtemperatureoftheairenteringthetower,including theeffectofanyrecirculationand/orinterferenceEN13741:2
33、003(E) 7 3.1.15 fanpower powerconsumedbythefandriver,includingtheindicationwhethertheefficiencyofthedriveris includedornot 3.1.16 makeup wateraddedtothesystemtoreplacethewaterlostbyevaporation,driftblowdownandleakage 3.1.17 mechanicaldraughtcoolingtower coolingtowerwheretheaircirculationisproducedby
34、afan.Mayfurtherbecategorizedaseither: forceddraught:thefanislocatedintheenteringairstream induceddraught:thefanislocatedinthedischargeairstream 3.1.18 nonseriestypewetcoolingtower wetcoolingtower,thedesignofwhichisprojectdependent,andforwhichtheperformancedataand testevaluationatspecificoperatingcon
35、ditionsmaybesubjecttoagreement 3.1.19 opencircuit(wet)coolingtower coolingtowerwhereintheprocessfluidiswarmwaterwhichiscooledbythetransferofmassand heatthroughdirectcontactwithatmosphericair 3.1.20 pumphead sumofstaticheadanddynamicheadfromthecontractualinterfacetothedischargeofthedistribution syste
36、mtotheatmosphere 3.1.21 relativehumidity ratioofthemolefractionofwatervapourinagivenairsampletothemolefractionofwatervapourin asampleofsaturatedairatthesametemperatureandpressure,usuallyexpressedaspercentage 3.1.22 seriestypewetcoolingtower wetcoolingtower,thedesignofwhichisfixedanddescribedintheman
37、ufacturerscatalogueandfor whichtheperformancedataareavailable,whichallowstestevaluationoveradefinedrangeof operatingconditions 3.1.23 testperiod timedurationwherereadingsorrecordingsofeverymeasurementhavetobeaveraged,andtest periodresultsmaybecalculated 3.1.24 testreadings individualsetsofdatarecord
38、edatregularintervalsforeachinstrumentormeasurementpoint required 3.1.25 thermallag timeintervalbeforethetemperatureofthewaterleavingtheinfluenceofthecoolingairisdetectedat thepointofcoldwatertemperaturemeasurementEN13741:2003(E) 8 3.1.26 waterflowrate quantityofwarmwaterflowingintotheopencoolingtowe
39、r 3.1.27 waterloading waterquantityexpressedasquantityperunitoffillplanareaofthetower 3.1.28 wetbulbtemperature temperatureofair,whichwhenproperlymeasuredapproximatesthetemperatureofadiabatic saturation.Mayfurtherbecategorisedaseither: ambientwetbulbtemperature:thewetbulbtemperatureofairmeasuredwind
40、wardofthetowerand freefrominfluenceofthetower enteringwetbulbtemperature:thewetbulbtemperatureoftheairenteringthetower,includingthe effectofanyrecirculationand/orinterference NOTE Termslikeguaranteevaluesandacceptanceusedinthisstandardareunderstoodina technicalbutnotinalegalorcommercialsense. 3.2Sym
41、bols ForthepurposesofthisEuropeanStandard,thesymbolsofTable1apply.EN13741:2003(E) 9 Table1Symbols Symbols Designatedparameters Units t w Wetbulbtemperature C t wG Guaranteedwetbulbtemperature C t wk Wetbulbtemperaturemeasuredatreadingk C t h Hotwatertemperature C t hk Hotwatertemperaturemeasuredatre
42、adingk C t c Coldwatertemperature C t cg Guaranteedcoldwatertemperature C t ck Coldwatertemperatureatreadingk C t cfk Facevalueofcoldwatertemperatureatconditionsfoundatreadingk fromperformancecurves C t m Temperatureofthemakeupwater C z Range( t h t c ) K z G Guaranteedrange K z k Rangecalculatedfor
43、readingk( t hK t ck ) K D t P Temperatureincreaseduetopumpenergy K D t k Differencebetweenmeasuredcoldwatertemperature( t ck )andface value( t cfk )forreadingk K D t a Arithmeticaverageofall D t k K k Readingindication m Hotwaterflow I/s m G Guaranteedhotwaterflow I/s m k Hotwaterflowmeasuredatreadi
44、ng k I/s m m Makeupwaterflow l/s m b Blowdownwaterflow l/s F P Fanmotorpower kW F PG Guaranteedfanmotorpower KW p h Pumpdischargepressure kPa p c Pumpsuctionpressure kPa p si Staticpressureatcontractualtowerinlet kPa p di Dynamicpressureatcontractualtowerinlet kPa r gh j Gravitypressurecontractualinlet KPa p SO Staticpressureatcontractualoutlet kPa p do Dynamicpressureatcontractu
