EN 14705:2005
(Main)Heat exchangers - Method of measurement and evaluation of thermal performances of wet cooling towers
Heat exchangers - Method of measurement and evaluation of thermal performances of wet cooling towers
This European Standard specifies requirements, test methods and acceptance tests for thermal performances pumping head verification of wet cooling towers and plume abatement for wet/dry cooling towers.
This European Standard is applicable to natural draught wet cooling towers (see in 3.1.2.2) fan assisted natural draught cooling tower (see 3.1.2.3), wet/dry cooling towers (see 3.1.2.4) and "Mechanical draught cooling towers", except series ones.
It specifies the test methods, the apparatus required, the limitation of errors and the method for results examination.
The acceptance testing covers the verification of the thermal performance data and pumping head of the cooling tower as specified in the contract between the supplier and the purchaser. If these tests are required then this should be recognized at the time of the contract, as additional fittings, and preparations for the test may be required.
Deviations from the rules laid down below as well as additions need special agreement between purchaser and supplier and should be documented.
This standard does not apply to mechanical draught series wet cooling towers which are dealt with in prEN 13741.
NOTE Terms like "design", "values", "guarantee" and "acceptance" used in this standard should be understood in a technical but not in a legal or commercial sense.
Wärmeaustauscher - Verfahren zur Messung und Bewertung der wärmetechnischen Leistungskenndaten von Nasskühltürmen
Diese Europäische Norm legt Anforderungen, Prüfverfahren und Abnahmeprüfungen zum Nachweis wärmetechnischer
Leistungskenndaten, der Pumpförderhöhe für Nasskühltürme sowie zur Verminderung von
sichtbaren Schwaden für Nass-/Trockenkühltürme fest.
Diese Europäische Norm gilt für Naturzug-Nasskühltürme (siehe 3.1.2.2), für Naturzugkühltürme mit
Ventilatorunterstützung (siehe 3.1.2.3), Nass-/Trockenkühltürme (siehe 3.1.2.4) und mit Ausnahme von
Serienkühltürmen auch für zwangsbelüftete Kühltürme.
Es werden Prüfverfahren, die erforderlichen Prüfgeräte, Fehlergrenzen und das Verfahren zur Auswertung der
Ergebnisse festgelegt.
Die Abnahmeprüfung umfasst den Nachweis wärmetechnischer Kenndaten und der Pumpförderhöhe für
Kühltürme, die im Vertrag zwischen Lieferant und Käufer festgelegt sind. Falls Abnahmeprüfungen gefordert
werden, sollten sie bereits im Vertrag festgelegt werden, da zusätzliche Prüfausrüstungen und -vorbereitungen
erforderlich werden können.
Abweichungen von und Zusätze zu den nachfolgend festgelegten Regeln bedürfen einer besonderen
Vereinbarung zwischen Käufer und Lieferant und sollten dokumentiert werden.
Die vorliegende Norm gilt nicht für zwangsbelüftete Serien-Nasskühltürme, die in EN 13741 erfasst werden.
ANMERKUNG Ausdrücke wie Auslegung, Werte� Garantie und Abnahme werden in dieser Norm im technischen
und nicht im juristischen oder kaufmännischen Sinne gebraucht.
Echangeurs de chaleur - Méthode de mesure et évaluation des performances thermiques des aéroréfrigérants humides
La présente Norme européenne spécifie les exigences, les méthodes d'essai et les essais de des performances thermiques, de la vérification de la hauteur de refoulement des aéroréfrigérants humides et de la réduction du panache des aéroréfrigérants humides/secs.
La présente Norme européenne est appliquée aux aéroréfrigérants humides à tirage naturel (voir 3.1.2.2), aux aéroréfrigérants à tirage naturel assisté par ventilateur (voir 3.1.2.3), aux aéroréfrigérants humides/secs (voir 3.1.2.4) et aux " aéroréfrigérants à tirage mécanique ", à l'exception des aéroréfrigérants à tirage mécanique réalisés de série.
Elle précise les méthodes d'essai, les appareillages nécessaires, la limitation des erreurs et la méthode d'évaluation des résultats.
Les essais de réception couvrent la vérification des données de performances thermiques et de la hauteur de refoulement de l'aéroréfrigérant telle que spécifiée dans le contrat entre le fournisseur et le client. Lorsque ces essais sont exigé, cela doit être précisé lors du contrat, comme des équipements complémentaires et la préparatoire des essais peut être nécessaire.
Des divergences par rapport aux règles décrites ci-dessous ainsi que des additions nécessitent un accord spécial entre le fournisseur et le client et il convient qu'elles soient consignées par écrit.
La présente norme ne s'applique pas aux aéroréfrigérants humides à tirage mécanique réalisés en série qui sont traités dans le prEN 13741.
NOTE Il convient de comprendre les termes tels que "utile", "valeurs", "garantie" et "réception" utilisés dans la présente norme dans un sens technique mais non pas dans un sens juridique ou commercial.
Prenosniki toplote – Merilna metoda in ocenjevanje toplotnih lastnosti mokrih hladilnih stolpov
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2005
Prenosniki toplote – Merilna metoda in ocenjevanje toplotnih lastnosti mokrih
hladilnih stolpov
Heat exchangers - Method of measurement and evaluation of thermal performances of
wet cooling towers
Wärmeaustauscher - Verfahren zur Messung und Bewertung der wärmetechnischen
Leistungskenndaten von Nasskühltürmen
Echangeurs de chaleur - Méthode de mesure et évaluation des performances
thermiques des aéroréfrigérants humides
Ta slovenski standard je istoveten z: EN 14705:2005
ICS:
27.060.30 Grelniki vode in prenosniki Boilers and heat exchangers
toplote
27.200 Hladilna tehnologija Refrigerating technology
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 14705
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2005
ICS 27.060.30; 27.200
English version
Heat exchangers - Method of measurement and evaluation of
thermal performances of wet cooling towers
Echangeurs de chaleur - Méthode de mesure et évaluation Wärmeaustauscher - Verfahren zur Messung und
des performances thermiques des aéroréfrigérants Bewertung der wärmetechnischen Leistungskenndaten von
humides Nasskühltürmen
This European Standard was approved by CEN on 24 March 2005.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14705:2005: E
worldwide for CEN national Members.
Contents page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms, definitions and symbols .5
3.1 Terms and definitions.5
3.2 Symbols.7
4 Performance tests – General.11
5 Guarantee .12
5.1 General .12
5.2 Guarantee documents .12
5.3 Validity conditions for measurements .13
6 Test procedure .15
6.1 Test parameters .15
6.2 Quantities to be measured .15
6.3 Quantities to be determined.17
6.4 Measurements and calculation of the mean quantities .17
6.5 Arrangement of measuring devices .24
6.6 Measuring apparatus .29
7 Conducting the performance tests.30
7.1 Definition of a test.30
7.2 Duration of the test .31
8 Calculation methods.34
8.1 General .34
8.2 Methods .34
9 Evaluation of thermal performances .38
9.1 General .38
9.2 Basic thermal performance test evaluation .38
9.3 Extended thermal performance test evaluation.39
10 Test tolerance.47
10.1 General .47
10.2 Error created by non-measurable systematic deviations of operating parameters.47
Annex A (informative) Performance curves.50
Annex B (normative) Requirements concerning the measuring apparatus used for the tests .54
Annex C (normative) Calculation of the evaporated water flow rate .56
Annex D (normative) Reminders on error calculations .59
Annex E (normative) Cold water temperature correction for heat added by pump.61
Bibliography.62
Foreword
This European Standard (EN 14705:2005) has been prepared by Technical Committee CEN/TC 110 “Heat
exchangers”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2005, and conflicting national standards shall be withdrawn
at the latest by December 2005.
This document includes a Bibliography.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
1 Scope
This European Standard specifies requirements, test methods and acceptance tests for thermal performances
pumping head verification of wet cooling towers and plume abatement for wet/dry cooling towers.
This European Standard is applicable to natural draught wet cooling towers (see in 3.1.2.2) fan assisted
natural draught cooling tower (see 3.1.2.3), wet/dry cooling towers (see 3.1.2.4) and "Mechanical draught
cooling towers", except series ones.
It specifies the test methods, the apparatus required, the limitation of errors and the method for results
examination.
The acceptance testing covers the verification of the thermal performance data and pumping head of the
cooling tower as specified in the contract between the supplier and the purchaser. If these tests are required
then this should be recognized at the time of the contract, as additional fittings, and preparations for the test
may be required.
Deviations from the rules laid down below as well as additions need special agreement between purchaser
and supplier and should be documented.
This standard does not apply to mechanical draught series wet cooling towers which are dealt with in
EN 13741.
NOTE Terms like "design", "values", "guarantee" and "acceptance" used in this standard should be understood in a
technical but not in a legal or commercial sense.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 306, Heat exchangers - Methods of measuring the parameters necessary for establishing the performance
EN 872, Water quality - Determination of suspended solids - Method by filtration through glass fibre filters
EN 60751, Industrial platinum resistance thermometer sensors (IEC 60751:1983 + A1:1986)
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 1438-1, Water flow measurement in open channels using weirs and Venturi flumes - Part 1: Thin-plate
weirs
ISO 2975-3, Measurement of water flow in closed conduits - Tracer methods - Part 3: Constant rate injection
method using radioactive tracers
ISO/TR 3313, Measurement of fluid flow in closed conduits - Guidelines on the effects of flow pulsations on
flow-measurement instruments
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
3.1.1
cooling tower
apparatus in which water is cooled down by heat exchange with ambient air
3.1.2
wet cooling tower
cooling tower in which the heat exchange between the water and the air is achieved by a direct contact
3.1.2.1
mechanical draught wet cooling tower
wet cooling tower where the air circulation is produced by a fan
3.1.2.1.1
series type mechanical draught wet cooling tower
mechanical draught wet cooling tower, the design of which is fixed and described in the manufacturer's
catalogue and for which the performance data are available, which allows tests evaluation over the defined
range of operating conditions
3.1.2.1.2
non series type mechanical draught wet cooling tower
mechanical draught wet cooling tower, the design of which is project dependent and for which the
performance data and test evaluation at specific operating conditions may be subject to agreement
3.1.2.2
natural draught cooling tower
wet cooling tower where the air circulation is produced only by a density difference between the cold air
outside the cooling tower and the hot air inside
3.1.2.3
fan assisted natural draught cooling tower
natural draught cooling tower with the addition of fan to boost the draught
3.1.2.4
wet/dry cooling tower (reduced plume cooling tower)
cooling tower comprising two parts. In the first part, the heat exchange between the water and the air is
achieved by direct contact and through a tight wall in the second part
3.1.2.4.1
reduced plume wet/dry cooling tower
wet/dry cooling tower designed for plume abatement
3.1.2.4.2
water conservation wet/dry cooling tower
wet/dry cooling tower designed for water conservation
3.1.3
air flow
total quantity of air, including associated water vapour flowing through the tower
3.1.3.1
counterflow
where air and water flows are in opposite direction in the filling
3.1.3.2
cross flow
where air flows perpendicular to the water in the filling
3.1.4
ambient wet (dry) bulb temperature
wet (dry) bulb temperature of air measured windward of the tower and free from the influence of the tower
3.1.5
approach
difference between recooled water temperature and inlet air wet bulb temperature
3.1.6
inlet water flow
quantity of hot water flowing into the tower
3.1.7
cold water basin
device underlying the tower to receive the recooled water from the tower and direct its flow to the suction line
or sump
3.1.8
cooling range
difference between the hot water temperature and the recooled water temperature
NOTE The term "range" is also applied to this definition, but is regarded as a non-preferred term.
3.1.9
drift loss
water lost from the tower as liquid droplets with the same chemical characteristics as the circulating water,
entrained in the outlet air
3.1.10
heat load
rate of heat to be removed from the water wi
...
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